Analysis of thgrinding using conventional and superabrasive CBN grinding wheels

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A novel cutting force modelling method for cylindrical end mill

A review of the literature shows that there exist two typical methods for calibrating cutting force coefﬁcients, i.e., the orthogonal to oblique cutting transformation method and the direct calibration method. The former estimates the cutting force coefﬁcients by means of a generic oblique cutting analysis using the shear angle, friction angle and shear yield stress from orthogonal cutting tests. Following this idea, Armarego and Deshpande [6] calculated the cutting force coefﬁcients for cylindrical end milling by analyzing the geometric characteristics of ﬂat end mill. Budak et al. [7] also proposed a method to determine the cutting force coefﬁcients for cylindrical end milling from orthogonal cutting tests with oblique cutting
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Article history: Received 17 July 2008 Received in revised form 2 September 2009 Accepted 7 September 2009 Available online 10 September 2009

天然低共熔溶剂提取黄酮类化合物的研究进展

于德涵，黎莉，苏适. 天然低共熔溶剂提取黄酮类化合物的研究进展[J]. 食品工业科技，2023，44（24）：367−375. doi:10.13386/j.issn1002-0306.2023020204YU Dehan, LI Li, SU Shi. Research Progress on Extraction of Flavonoids Using Natural Deep Eutectic Solvents[J]. Science and Technology of Food Industry, 2023, 44(24): 367−375. (in Chinese with English abstract). doi: 10.13386/j.issn1002-0306.2023020204· 专题综述 ·天然低共熔溶剂提取黄酮类化合物的研究进展于德涵*，黎　莉，苏　适（绥化学院食品与制药工程学院，黑龙江绥化 152061）摘　要：天然低共熔溶剂是一种新型绿色溶剂，有望替代传统有机溶剂实现对黄酮等天然产物的高效提取。

为了阐明天然低共熔溶剂在黄酮化合物萃取方面的应用，本文对近5年发表的相关研究论文进行了整理和分析，综述了天然低共熔溶剂提取黄酮的研究现状，并详细讨论了影响提取率的各种因素。

天然低共熔溶剂在黄酮、黄酮醇、二氢黄酮、花色素、异黄酮等多类天然黄酮产物的提取方面表现良好，其萃取率普遍优于甲醇、乙醇等传统溶剂，且萃取产物活性更高；低共熔溶剂的组成、摩尔比、含水量和温度等条件会显著影响其对黄酮化合物的萃取。

文章还对天然低共熔溶剂在未来的发展趋势作出展望，希望能为黄酮化合物的高效、绿色提取提供有益参考。

关键词：低共熔溶剂，黄酮类化合物，绿色溶剂，提取本文网刊: 中图分类号：TQ28、TS201 文献标识码：A 文章编号：1002−0306（2023）24−0367−09DOI: 10.13386/j.issn1002-0306.2023020204Research Progress on Extraction of Flavonoids Using Natural DeepEutectic SolventsYU Dehan *，LI Li ，SU Shi（Food and Pharmaceutical Engineering Department, Suihua University, Suihua 152061, China ）Abstract ：The natural deep eutectic solvent is a new type of green solvent that is expected to replace traditional organic solv-ents for efficient extraction of natural products such as flavonoids. In order to clarify the application of natural deep eutectic solvents in the extraction of flavonoids, the author summarizes and analyzes relevant research papers published in the past 5years. This article provides a review of the current research status of natural deep eutectic solvents for extracting flavonoids,and discuss in detail the various factors that affect the extraction rate. The natural deep eutectic solvents perform well in the extraction of various natural flavonoid products such as flavonoids, flavonols, flavonones, anthocyans, and isoflavones.Their extraction rates are generally better than traditional solvents such as methanol and ethanol, and the extracted products have higher activity. The composition, molar ratio, water content, and temperature of deep eutectic solvents signi-ficantly affect their extraction of flavonoids. Finally, the development trend of natural eutectic solvents in the future is prospected. This paper aims to provide reference for the efficient and green extraction of flavonoids.Key words ：deep eutectic solvents ；flavonoids ；green solvent ；extraction黄酮是植物细胞中一种重要的次级代谢产物，能够消除人体内自由基，有较强抗氧化、抗衰老的功能[1]，在抗菌、抗病毒、抗炎、降血糖、降血脂等方面也颇有功效[2]。

外文翻译王利刚

英文原文:Scandinavian Furniture DesignScandinavian design is 30 years in the 20th century Having achieved great success, and acquired an international reputation for design. The style is concerned, the Scandinavian design is the function of doctrine, but not as stringent as the 20th century, 30 years and doctrines.as stringent as the 20th century, 30 years and doctrines. Geometric form of soften, and edges are fairing into S-shaped curve or wavy lines, often described as "organic form", so that the form of more humane and angry. Before the war with Bauhaus functionalism as the center 40 years in the 20th century, under the difficult conditions of material deprivation is widely accepted, but by the mid-20th century, 40, functionalism has been gradually includes a number of practical and style changes. These changes left the Bauhaus pure geometric forms and "works" the language of aesthetics, most notably the Scandinavian design. As early as 1930, the Stockholm Fair, Germany, Scandinavian design will be a strict functionalism and local arts and crafts in the humanist tradition of integrating their together. In the 1939 New York International Exposition, but also established the "Swedish Modern style," as the concept of an international status. After the 20th century, 40 years after a difficult period, Scandinavian design in the 20th century, 50 years produced a new leap forward. Its simple and organic shape and natural color and texture very popular in the international arena. Milan Triennial in 1954, the international design exhibition, Scandinavian design show a new look, the participation of Sweden, Denmark, Finland and Norway have achieved great success. The design of these countries after the war, the organization implemented a policy of cooperation, their first major achievement was called "Scandinavian Design" exhibition. Arts Foundation in the United States under the sponsorship of this exhibition from 1954-1957 in North America in 22 years, the city's main museums around the world, thus making "Scandinavian design" the image of the widely popular in the international community. Function of the Scandinavianmodern design movement, the countries in the design organization at the national or local level, held a large number of exhibitions, the 20th century, these activities have become a key feature of the 50's. Scandinavian design of the Year, held alternately in various countries, affecting a wide range, which, together with the publications and periodicals for the design of the exchanges made a significant contribution. Design organizations not only exhibitions, they are also an important advocate in this area designed to encourage manufacturers to invest in a creative product development, to persuade the authorities to design policies to support its excellent design. They also inspire public awareness of good design and everyday use more beautiful thing, and this 50 to 60 for the 20th century, the early design development played an important role. In addition to designing the organization efforts, dominated the 20th century, 50 years of social and economic life of the development of the power of design has a more profound impact, with the process of industrialization and urbanization, the whole population structure has changed. Continuously improve the standard of living affected the majority of the people and their way of life, resulting in widespread optimism and confidence for the development and progress. New ideas begin to gain traction, such as that the ordinary people have the right to enjoy the comfort of home, the family is not only healthy, but also meets the functional and aesthetic requirements. In the 20th century, 50's, the ultimate welfare state built up in Scandinavia. The 20th century, 40 years in order to reflect the ethnic characteristics arising from a sense of nostalgia, often showing the pristine countryside, contributed to this softening trend. Early functionalism advocated by the primary color for the 20th century, 40 years to reconcile the color gradually replaced by a more coarse texture and natural materials by their favorite designers. After 1945, another retro trend - the Danish tradition of excellent craftsmanship in Sweden and Norway have also been strengthened. The 20th century, 50 years, a group of pre-war designers, such as the prestigious Henningsen, Klandt, mam Marsden, Aalto, etc. are still walking in the forefront of the design. For example, Henningsen, designed after the war, a number of new PH lamps, in particular, he designed a PH-5, and PH Artichoke pendant lamp has achieved great success and has soldbriskly. The other hand, young designers have also come to the fore, thus promoted the Scandinavian design of further development. Scandinavian design of the human touch is also reflected in the design of industrial equipment, in this respect Swedish industrial designer made a lot of work. From 1965 onwards, from Sweden, consisting of six designers "design team" involved in Solna, the company's offset printing production line development and design work, they operate on the production line process carried out a detailed ergonomic analysis and redesign the signs, symbols, instructions and manipulating the handle, so that working conditions have been greatly improved.Danish furniture design has a tradition dating back almost 450 years .In 1554, a numb er of cabinetmakers founded Koebenhavns Snedkerlaug (The Copenhagen Guild of Cabine tmakers) with the dual purpose of creating high-quality furniture and of protecting the trad e from poor craftsmen by establishing formal training for cabin-makers.Two hundred years later,in 1777,Det Kongelige Meoble Magazine (The Royal Furniture M agazine) was established with the aim of manufacturing uniform,high-quality furniture in t erms of production and design for the Danish Royal Household and its various departments and ministries ,etc.The furniture was designed almost along the lines of catalogue goods b y the most renowned designers of the period,and their drawings were forwarded to master cabinetmakers all over the country,who then manufactured them.After a brief period of only 40 years,the practice came to an end in 1815.The importan t thing is that the above-mentioned events were extremely visionary as regards quality and design,and that they went on to form a solid foundation for later development.Furthermore, Det Kongelige Danske Kunstakademi (The Royal Danish Academy of Art) in Copenhagen, established a school of furniture design in 1770,whose purpose was the education of furnit ure apprentices to draw and inspect masterpieces what amounted to the world’s first system atic education of furniture designer.Throughout the 19th century,indeed until the beginning of the 1920’s, there is an absence of an independent Danish style.The architects of the time are inspired by French, and particularly,English furniture and only design furniture for the wealthy upper classes and civil authorities. Peasants,farmers and the fledgling working class still do not represent an interesting commercial body,but this picture changes with the cou ntry’s move from an agricultural society to an industrialized one towards the end of the last century.The cities almost exploded in size and social awareness flew with the emergence o f the new social classes-laborers and office workers-both of whom demanded monetary pa yment for their services.Put in simple terms,you might say that this was how the foundatio n of modern consumer society came into being. Once current overheads had been met such as food,clothing,rent and heating ,etc.People still had the means to buy furniture,which in its own small way, created the basis for a formalized furniture industry.The furniture industry did not really take off until people began moving away from the cramped apartments in the city centers to larger apartments and detached houses on the outskirts of town.This happened in two stages,the first of which was in the 1920’s,when the social housing projects began and detached houses started to appear.The second stage was in the 1950’s,when both types of housing be fan to shoot up ev erywhere.This development,combined with a high level of knowledge and awareness,creatd a new and more rational housing culture where people began to demand high-quality functional furniture.As it turned out, people outside Denmark soon began to make the same kinds of demands.The 1920’s saw the desire for a purely Danish style of furniture.In 1924,a lectureship i n furniture design was established at Kunstakademiets Arkitektskole (The Royal Danish Ac ademy of Fine Arts School of Architecture) in Copenhagen.The lectureship went to the Da nish architect,Kaare Klint(1888-1954), who influenced the development of Danish furnitur e design to a great degree.Kaare Klint was a systematist and a modernist who used his stud ents to pioneer a series of surveys and analyses of furniture and spatial needs. First and for emost,Kaare Klint represented the approach that furniture should be functional and user-fri endly,an approach which in many ways deviated from the rest of Europe,where functionali sm often took the form of formalistic exercises,directing its focus towards a well-to-do elit e rather than the ordinary man in the street.The result was that a strong,independent,humanistic functionalism evolved in Denmark through the 1930’s and 40’s,culminating in an international breakthrough at the beginnin g of the 1950’s.A contributory factor to this breakthrough was the Guild or Cabinetmakers’annual autumn exhibition held for the first time in 1928.Here, young furniture designers co uld find collaborative partners among the established cabinetmaker workshops with an eye to developing new types of furniture.It was at these exhibitions that Danish architects like Hans J.Wegner,Ole Wanscher, Finn Juhl,Boerge Mogensen,Arne Jacobsen and many others made their breakthrough,and it was at these same exhibitions in the period following the S econd World War that,in particular the American market,caught sight of Danish furniture d esign-Danish modern.The development of Danish furniture design continued forcefully up through the 1950’s and 60’s, resulting in a sharp increase in furniture exports.The starting point of Danish fu rniture production was joiner craftsmen furniture, but as technology developed ,production became increasingly industrialized and this affected the way in which architects designed f urniture. One of the best examples of the furniture of this period is architect, Professor Arn e Jacobsen’s famous ―Myren‖(―The Ant‖),designed in 1951 as a canteen chair for Novo No rdisk‖s new medicinal factory.The chair was developed in cooperation with the furniture m anufacturer Fritz Hansen A/S. From the beginning, It was designed as an industrial product for mass production. Some years later, in 1957,Arne Jacobsen designed a more streamline d version of ―The Ant‖ for Fritz Hansen A/S, the so-called 7-series and these chairs became a huge success with 5 million chairs sold to date. His collaboration with Fritz Hansen A/S continued until his death in 1971. In addition to ―The Ant‖ and the 7-series, Arne Jacobsen and Fritz Hansec succeeded in creating a long series of Danish furniture classics, such as th e easy chairs ―Aegget‖(―The Egg‖) and Svanen (―The Swan‖), which Jacobsen designed fo r the SAS Royal Hotel in Copenhagen in 1959. These two chairs were remarkable inasmuc h as Jacobsen pioneered the use of expanded polystyrene in furniture-chairs ahead of the ti mes.There were others too, designers who designed industrially manufactured furniture. In 1942, FDB(The Danish Co-op Society) hired the 28 year old furniture designer, Borge Mogensen, as chief designer for FDB’s newly established furniture design studio. Borge Moge nsen was a former student of Kaare Klint, and Mogensen further developed Klint’s ideas re garding quality functional furniture for the ordinary consumer. FDB’s furniture was manuf actured in wood, especially in the domestic wood sorts of oak and beech. These chairs wer e designed for industrial manufacture and despite the fact this was ―furniture for the comm on man‖, it was still of a very high calibre, both in terms of functionality and design. Later on, Boerge Mogensen created a name for himself by designing exclusive furniture in an alt ogether different price bracket for affluent clientele. Despite this, he never diverged from h is principles of functionality and user-friendliness.The two designers who really put Denmark on the world map were Hans J.Wegner (b orn 1914) and Finn Juhl (1912-1989). These two men came from radically different backgr ounds. Hans J.Wegner was the country craftsman who had received his training as furniture designer at Kunsthaandvaerkerskolen (The Danish School of Arts &Crafts). Jinn Juhl was the cosmopolitan academic from Copenhagen, who had been educated as an architect at the Kunstakademiet (The Royal Danish Academy of Jine Arts). Both men had an amazing feel for design and a deep-seated desire to create beautiful, functional furniture. As a result, the y created a long series of furniture classics over a period lasting 40 years; classics which ev en today stand out as exceptional. Their production of quality furniture is so extensive-Han s J.Wegner alone is responsible for more than 500 models-that it is impossible to highlight the work of one or the other. Particular examples of Hans J.Wegner’s unique design work a re Kinastolen (―The Chinese Chair‖) from 1945, The Chair from 1949, and Cirkelstolen (―The Circle Chair‖) from 1986. Among Finn Juhl’s furniture are such highlights as his armc hair made for the Guild of Cabinetmakers’ autumn exhibition in 1944 and Hoevdingstolen (The Chieftain Chair) from 1949. It was chairs like these that won Denmark its reputation a s the world’s leading design nation.Around 1970, Denmark began to experience stiff competition from Italy at the numer ous furniture fairs around the world, and in particular, at the furniture fairs around the worl d, and in particular, at the furniture fairs in Cologne and Chicago. The Italian designers andfurniture manufacturers moved in new directions and experimented with all kinds of mater ials and expression, which caused Danish furniture to appear behind the times. It was really only the Danish designer, Verner Panton, who lived in Switzerland, who understood how t o use the new man-made materials and create new designs.This was a critical period in Da nish furniture design and for the Danish furniture industry which found it difficult to maint ain its position as marker leader. This situation was not only caused by the challenge posed by the Italian designers. It was also the result of too much success.The good international reputation of Danish furniture design had built by a handful of furniture manufacturers who were interested in good design and the use of talented designe rs. In the wake of their success however, were a large number of less serious furniture man ufacturers. Who swamped the market with unoriginal furniture, usually of poor quality, whi ch was hastily marketed under the label of Danish Design.Fortunately, there were new, talented designers on the way up: people like the Danish designers, Bernt, Rud Thygesen&Johnny Soerensen, Johannes Foersom&Peter Hiort-Lore nzen, Gunver&Niels Joergen Haugesen, Joergen Gammelgaard, as well as Nanna Ditzel an d Poul Kjaerholm. These designers helped to lift the heavy legacy left to them by the ―Gold en Age‖ of Danish design in the 1950’s and 60’s, and fortunately, there were still furniture manufacturers willing to bank on quality design.The greatest problem for Danish furniture design of the period was that the manufactu re of furniture was becoming more and more industrialised. The meant that designers had t o come up with far more rational designs than before. The fact that training at the architect and design colleges was to a high degree based on artistry and craftsmanship caused a goo d deal of friction between designers and manufacturers. Many designers felt that the manuf acturers only had an eye for profit margins and mass production. For their part, the manufa cturers felt that the designers only thought about designing expensive furniture and of maki ng a name for themselves. This was not a good foundation for developing Danish furniture design and both parties were lacking a viable model with which to move on. It was a small, elegant chair and accompanying table series in laminated beechwood which marked the start of the second ―Golden Age‖ of Danish furniture design. The new furniture was presente d at the annual Scandinavian Furniture Fair at The Bella Centre in 1974 and was designed by the young architects Rud Thygesen & Johnny soerensen for the furniture manufacturer Magnus Olesen A/S. The chair and the table series were specifically designed as industrial products in a functional design and were of a very high quality. To top it all, they were relat ively cheap as well. The fact that this could be done was partly because the designers had r ediscovered the industrial and design qualities of the laminating technique, and partly beca use they had gambled on the contract market rather on the market for household furniture. The laminating technique was well known: the Finnish designer, Alvar Alto and the Swedis h designer, Bruno Mathsson had already created a long line of beautiful laminated furniture in the 1930’s and 40’s–and in Denmark, people like Arne Jacobsen had developed series o f laminated furniture. What made Rud Thygesen & Johnny Soerensen’s approach so unique was the fact that they regarded their furniture as industrial products instead of one-of-a-kin d, craftsman-made goods. Their furniture was highly adapted to rational mass production, a lmost kike industrial design. More inportant still was the fact that an extremely viable mod el for collaboration between designers and manufacturers had been found. This model creat ed a school of thought and convinced the furniture industry that good design could actually pay!As we approach a new century, there is every reason to have high expectations for the continued development of Danish furniture design. Never before has so much quality furnit ure been manufactured, and young, new designers are making their mark. People like the d esigner Troels Grum-Schwensen, Kasper Salto, Henrik Tengler, Hans Sandgren Jacobsen, Tom Srepp, Pelikan Design, Komplot Design and various other groups of designers. The most interesting feature of the development of furniture design from 1980 to the present da y is that it essentially followed its own path, more or less uninfluenced by changing styles: the postmodernism, high-tech, neoclassic of the 1980’s, the rediscovery of art deco at the b eginning of the 1990’s together with neo-functionalism and the renewed interest for the des ign of the 1960’s-all of these are styles which have been ostentatiously introduced (and reintroduced) at the great furniture fairs in Cologne and Milan since 1980, and nearly all have disappeared again. Danish furniture designers and furniture manufacturers however, have n ot felt tempted to follow these trends. This is not out of fear but rather out of a deep-rooted unwillingness to be dictated to by whimsical trends which do not add anything new to furni ture design. Instead, they have continued to develop and refine Scandinavian modernism w hich is characterised by its great care for detail and the manufacturing process, respect for t he human anatomy, thorough analyses of requirements and use, aesthetics and consideratio ns about form and function and rational production. This is a work approach which has attr acted wide international attention in the course of the last five to six years, and one which many international designers have tried to copy, as was the case with the Danish furniture d esigns of ―the Golden Age‖ 30-40 years ago.It is this same work approach which will prob ably guarantee the leading position of Danish furniture design for many years to come: inn ovation via tradition.Given the fact that the western concept of art from the end of the 18th century moved towards the ever-increasing independence of artistic expression, part of the task of modern art became to reassemble what had been dismantled. The boundary between fine and mass culture narrowed.Visual art, architecture and applied art were to be seen as aspects of a co mmon dream; the ideal of powerful, modern expression. The beginning of the 20th century saw the introduction of the term ―Gesamtkunstwerk‖. A house was no longer a frame arou nd random content. Buildings, furniture design, decorative art and interior design generally were to support the integral whole, which became greater than the sum of its individual pa rts.From the 1920’s and 30’s, the dominant German Bauhaus School greatly influenced design in Europe and America. Architect and School Director, Walter Gropius, expressed his intentions in the following way:‖Our ultimate goal was the compound yet indivisible work of art, the unique building where the old boundary between the monumental and decorative elements vanished forever‖.In Denmark, architects led by Arne Jacobsen, among others, were extremely stimulated by this way of thinking. Here lay the keystone to the tradition of interrelationship betwee n architecture and interior design, which to this day remains an important hallmark of Dani sh architects and designers. Since 1971,the architectural firm of Dissing+Weitling A/S has continued to run and develop Arne Jacobsen’s architect business, with employees in Denm ark and around the world. The depth in Dissing+Weitling’s work is exceptional but this als o says something characteristic about the Danish approach. Here we find both a sense of w holeness as well as an attention to detail, and especially, the challenge of getting both elem ents to form a synthesis. Nothing is too small, let alone irrelevant to warrant care and attent ion.In addition to architectural buildings, Dissing+Weitling also carry out work in the fiel ds of furniture, lighting design, and medico-technical equipment. In all events, it is an atte mpt to merge the various parameters such as form, function, construction, materials and col or to form a balanced expression whose hallmark is a strong visual identity, which is the lei tmotif of the design process: A clarity and purity which has timeless and universal qualities . In this regard, Dissing+Weitling have done a supreme job of carrying on the legacy of Ar ne Jacobsen.Whereas at the close of this century, we have witnessed the noisier, mishmash of diversity of international design reflecting the spirit of the times, here in Denmark-and t he Nordic countries-the modernistic method and approach has prevailed. Design has been c arried forward with moderation and variations based on a tighter minimalism, focusing on t he elements and dynamics of the individual form, as well as a pronounced sensitivity for m aterials. There are many examples of how this subtle dialogue between space, furniture and interior design have found powerful expression; designs which break up and imprint a diff erent rhythm on the space and the way in which fine contrasts such as the lineatity of the ro om are juxtaposed by the curvature of the reception area-a common, repeated theme in ma ny interiors.It is important to remember that interior designers are not housebuilders like architects . Interior designers are given finished rooms whose interiors they have to design. For this r eason, all interior design deals with ―treatment of the room‖ and the Scandinavian traditionfor this is strongly linked to Scandinavian modernism, i.e. humanism and democracy paire d with functionalism, which again is linked to the architectural tradition.The restoration of old buildings also exerts an influence on the work of Danish architects and interior designe rs. An extensive series of buildings has been restored with respect for existing architecture and the qualities of past design. Many buildings have been thoroughly renovated with an e ye to meeting new functions and modern requirements.The balance between maintaining th e original distinctive architectural features and ensuring a modern design poses a continuin g challenge. This is exactly where a comprehensive staging with the designing of special fu rniture and fixtures can become a means of ensuring a uniformity of style and expression.中文翻译：北欧家具设计斯堪的纳维亚设计是在20世纪30年代即已取得较大成就,并获得了国际声誉的设计风格。

成型磨齿机磨削烧伤的分析和防止措施_赵璞

第28卷第2期河北工业科技Vo l.28,N o.22011年3月H ebei Journal o f Indust rial Science and T echnolo gyM ar.2011文章编号:1008-1534(2011)02-0118-04成型磨齿机磨削烧伤的分析和防止措施赵璞,陈建平(天津科技大学机械工程学院,天津 300222)摘要:就如何减少大型重载齿轮的磨削烧伤,结合生产实际,分析了成型磨削原理、磨削烧伤的成因和检测方法,并就影响磨削烧伤的机床磨削方法、表面渗碳浓度、渗层显微组织、砂轮和修整轮、对中过程、切削参数、冷却液和辅助工艺进行了探讨,提出了相应的措施。

关键词:磨削烧伤;高速磨削;大型重载齿轮中图分类号:TH 114 文献标志码:AAnalysis and prevention of gear grindingburning during form grindingZH AO Pu,CH EN Jian -ping(M echanical Engineer ing Colleg e,T ianjin U niver sity o f Science and T echno lo gy ,T ianjin 300222,China)Abstract:Concerning the reduction of the rate of g ear g rinding bur ning in practical machining,this article gav e a presentationof fo rm g rinding pr inciples,the reasons for gear g r inding burning and the measuring metho ds.T hen it analy sed some key fac -tor s which affect g rinding burning,including the sur face carburizing co ncentration,the micro st ructur e o f cementite,t he g rind -ing w heel and dressing r oll,center ing process,cutting par ameters,and cut ting oil.F inally it present ed the r elevant prevention w ays.Key words:g rinding burn;hig h speed g rinding;heavy duty g ear 收稿日期:2010-11-01;修回日期:2010-12-28责任编辑:张军基金项目:天津市2010年重点基金资助项目(10JCZDJ C23300)作者简介:赵璞(1977-),男,天津人,工程师,硕士研究生,主要从事机械制造及其自动化方面的研究。

Conversation Analysis

Conversation AnalysisThe world is changing in every minute,but something is still important. You live in the world,so you must communicate with others. But what is the most important ?I think the answer is ourselves. So conversational skills are very important. However ,language is the major barrier for us because sometimes we have difficulties in expressing our opinions,and sometimes we just keep silence. But it doesn’t mean we are not friendly ,we just don’t know how to express ourselves. So when I have a chance to speak with native speakers,I think write a conversation analysis is necessary. In this conversation,I consider several strategies in order to help myself to develop stronger skills in communication in the future. Specifically ,the strategies that will be addressed are encouraging communication ,mainting a conversation,and language fluency .We want to chatting with others to have a good time,therefore,a conversation should go further than merely talking about the weather,the clothes or the lunch or something like that. As a result,encouraging communication and response to others’ sentences is an important tactic to have an interesting conversation between the speakers.When I talk to Amy,we both encouraged each other’s conversation by giving short responses:In lines4,5,6,17. Amy and I both used“Yeah”to show that we werepaying attention to the other person. I said“really?”to show that I was interested in what Amy was talking about. And when I knew he parents are both Chinese from Taiwai. I am really surprised. Because she never say Chinese. When I asked about it,she said she just can speak a little Chinese. So I said “we can learn from each other. ”I think the atmosphere is very good. In addition,we used body language to explain something I can’t express in English like roller coaster and to demonstrate that we were listening to one another.We nodded and said“Yeah,I know.”when we agreed with the other person’s opinions. Besides nodding and giving short responses,I asked Amy an open question(like line 12)about her holiday and major after I expressed my opinion on UCLA. Although I wanted to use the strategy of asking her a question,I didn’t ask the question effectively. When I asked Amy something about ESL,she responded by “Ah?”. Sometimes she he seemed to be confused by my question. So I changed my questions to prevent confusion in this conversation. Therefore,to prevent having a boring conversation ,using short response,body language,appropriate question, and emphasis on specific words are important ways to give and receive encouragement for the native speaker and the ESL students. Of course,smile is also important. You can use your face expressions to express your mood.At first,I feel a little nervous because I just had a little chances to talk to native speakers,but with the conversation going on,when we talked about sports andfound that we were both interested in it,I feel comfortable. Not only that I knew about the life in LA,I also learned the different important skills in conversation which could help me to interact with English speakers in the future. After transcribing and analyzing the conversation,which were encouraging communication,maintaining a conversation,and language fluency. From the experience,I understood the weaknesses in my English and different ways to express my thoughts to foreigners ,and I realized something I never paid attention to before and I will pay attention and effort to improve.In my opinion,if we become more confident and relax in talking to native speakers,we can communicate with others well. The most difficult thing fou us is open our mouths. Most Chinese are shy and some of them are afraid of making mistakes,so they didn’t want to talk with native speakers when they are free,therefore,their spoken English and pronunciation will stay in the same level. If we can spend our time in talking with native speakers,we can learn more about their culture and communicate well,so the conversation skills are very important.If we practice our English in real-life situations,we are able to overcome the language barriers and enhance our communication skills.。

Q2（R1）中英文对照

Q2（R1）中英⽂对照REQUIREMENTS FOR REGISTRATION OF PHARMACEUTICALS FORHUMAN USE⼈⽤药品的注册要求ICH HARMONISED TRIPARTITE GUIDELINEICH协调的三⽅指导原则VALIDATION OF ANALYTICAL PROCEDURES: TEXT ANDMETHODOLOGY分析⽅法验证：正⽂和⽅法学Q2(R1)Current Step 4 version现⾏第4阶段版本Parent Guideline dated 27 October 1994最初指导原则起于1994年10⽉27⽇(Complementary Guideline on Methodology dated 6 November 1996incorporated in November 2005)（⽅法学补充指导原则完成于1996年11⽉6⽇，于2005年11⽉合并）This Guideline has been developed by the appropriate ICH Expert Working Group and has been subject to consultation by the regulatory parties, in accordance with the ICH Process. At Step 4 of the Process the final draft is recommended for adoption to the regulatory bodies of the European Union, Japan and USA.此指导原则由适当的ICH专家⼯作组起草，经调整团磋商，于ICH过程⼀致。

在第四阶段，最终的草案推荐给欧盟，⽇本和美国的监管机构采⽤。

Q2(R1) Document Historydeveloped to complement the Parent GuidelinePART I:TEXT ON VALIDATION OF ANALYTICAL PROCEDURES分析⽅法验证⽂件ICH Harmonised Tripartite GuidelineICH协调三⽅指导原则Having reached Step 4 of the ICH Process at the ICH Steering Committee meeting on 27 October 1994, this guideline is recommended for adoption tothe three regulatory parties to ICH1994年10⽉27⽇的ICH策划委员会会议已经进⼊了ICH进程的第4阶段，此指导原则推荐给ICH三个监管部门采纳1. IntroductionThis document presents a discussion of the characteristics for consideration during the validation of the analytical procedures included as part of registration applications submitted within the EC, Japan and USA. This document does not necessarily seek to cover the testing that may be required for registration in, or export to, other areas of the world. Furthermore, this text presentation serves as a collection of terms, and their definitions, and is not intended to provide direction on how to accomplish validation. These terms and definitions are meant to bridge the differences that often exist between various compendia and regulators of the EC, Japan and USA.1．介绍作为递交给欧共体，⽇本和美国新药注册申请资料的⼀部分，对分析⽅法验证需考虑事项的特征的讨论在此⽂件呈现出来。

凤冈锌硒茶挥发性成分提取及其香气成分分析

何婷，吴其妹，向丽萍，等. 凤冈锌硒茶挥发性成分提取及其香气成分分析[J]. 食品工业科技，2023，44（18）：342−351. doi:10.13386/j.issn1002-0306.2022100238HE Ting, WU Qimei, XIANG Liping, et al. Extraction of Volatile Compounds and Analysis of Aroma Characteristics in Fenggang Zinc-Selenium Tea[J]. Science and Technology of Food Industry, 2023, 44(18): 342−351. (in Chinese with English abstract). doi:10.13386/j.issn1002-0306.2022100238· 分析检测 ·凤冈锌硒茶挥发性成分提取及其香气成分分析何　婷1，吴其妹1, +，向丽萍2，冯　华1,2,*（1.遵义医科大学药学院，贵州遵义 563000；2.遵义市产品质量检验检测院，贵州遵义 563000）摘　要：为探究凤冈锌硒茶加工过程中挥发性成分变化。

采用顶空固相微萃取结合气相色谱-质谱联用技术对凤冈锌硒茶加工过程中挥发性组分进行检测，优化提取条件，利用主成分分析和正交偏最小二乘法回归分析，对凤冈锌硒茶加工过程中的挥发性组分进行判定、区分和筛选。

结果表明，提取工艺采用茶水比为1:6（g/mL ），通过50/30 μm CAR/DVB/PDMS 固相微萃取针在90 ℃条件下萃取70 min 为佳。

GC-MS 共鉴定出91种挥发性成分，共有挥发性组分37种，醇类、酮类、酯类和醛类是构成凤冈锌硒茶香气的主要挥发性组分，其中醇类物质最丰富，含量最高。

主成分分析可将凤冈锌硒茶加工前分为一类，加工后分为一类；正交偏最小二乘法回归分析表明15种挥发性组分对凤冈锌硒茶气味贡献较大。

翻译文献一

ReviewClay in cement-based materials:Critical overview ofstate-of-the-artM.L.Nehdi ⇑Department of Civil and Environmental Engineering,University of Western Ontario,London,Ontario,Canadah i g h l i g h t sCritical overview of effects of clay in cement-based materials is provided. Dimensional stability of aggregates bearing clay minerals is examined. Treatment of clays to mitigate their detrimental effects in concrete is outlined. Research on nano-clays in cement-based materials is highlighted.How to resolve ambiguity related to clays in cement-based materials is discussed.a r t i c l e i n f o Article history:Received 23May 2013Received in revised form 10October 2013Accepted 31October 2013Available online 28November 2013Keywords:Clay SandAggregate Concrete Workability Admixture Swelling Durability Nanoa b s t r a c tLimitations in guidelines and standards on the amount of clay in sand and coarse aggregate micro-ﬁnes and the inﬂuence of such micro-ﬁnes on fresh and hardened concrete properties is often ambiguous for practitioners and quality control professionals.This is compounded by conﬂicting related data in the open literature and the inadequacy of some standard test procedures for capturing the real problems associated with the presence of clays in cement-based materials.This paper examines the various types of clay,limitations on clays in aggregates in various standards,and the test methods used to assess the presence of clays in aggregates.A critical overview of literature on the possible effects of clay in cement-based materials is provided,including effects on water demand,workability,mechanical strength,dimensional stability and chemical admixtures dosage.The problem of dimensional stability of aggre-gates bearing clay minerals is examined.Possible chemical treatment of clays to mitigate their detrimen-tal effects in concrete is also outlined.Finally,emerging research on using nano-clays in cement-based materials is highlighted and recommendations to resolve ambiguity related to the presence of clays in cement-based materials are proposed.Ó2013Elsevier Ltd.All rights reserved.Contents 1.Introduction (373)2.Different clay minerals and their behaviour................................................................................3733.Mechanisms of clay swelling............................................................................................3744.Effects of clay on properties of concrete...................................................................................3745.Effects of clay on chemical admixtures....................................................................................3766.Expansion of aggregates with clay bearing minerals.........................................................................3767.Test methods for clay in cement-based materials ...........................................................................3767.1.Aggregate durability index ........................................................................................3777.2.Sand equivalent test .............................................................................................3777.3.Methylene blue test .............................................................................................3777.4.Grace colorimetric modified methylene blue method ..................................................................3788.Standard limitations on clay content in aggregates..........................................................................3789.Chemical treatment of aggregates to mitigate effects of clay ..................................................................37810.Nano-clay in cement-based materials....................................................................................3790950-0618/$-see front matter Ó2013Elsevier Ltd.All rights reserved./10.1016/j.conbuildmat.2013.10.059⇑Tel.:+1(519)6612111x88308.E-mail address:mnehdi@uwo.ca11.Concluding remarks (381)References (381)1.IntroductionThe Spanish proverb puts it best:‘‘clay and lime conceal much evil’’.This author sensed such perception of clay through personal involvement in high-proﬁle international projects(e.g.two of the tallest buildings in the world,world’s deepest and second largest water pumping and treatment plant,one of the world’s largest air-ports,a world landmark bridge,etc.).Ambiguity arises when stan-dards,technical provisions and subsequently project speciﬁcations may be unnecessarily restrictive on the amount of micro-ﬁnes al-lowed in aggregates used in concrete,while locally available sands and/or coarse aggregates cannot meet such limitations at compet-itive cost.Often futile debate emerges on what exactly is the nat-ure of aggregate micro-ﬁnes at hand,is it responsible for any performance issues of the concrete produced,how such an inﬂu-ence can be accurately quantiﬁed for various microﬁne contents, and can the limits on micro-ﬁnes be relaxed without short-or long-term performance problems of the concrete.The discussion can be fuelled with conﬂicting pieces of information sourced from the open literature or through personal communications.Therefore,this article is an attempt to demystify clay in con-crete,critically overview the state-of-the-art on this issue,and pro-vide a self-contained document that can scrutinise existing related data and the various pieces of evidence,examine the available test methods for evaluating the existence and effects of clays in ce-ment-based materials,and essentially savefort of navigating through this often2.Different clay minerals and theirDetailed information on clay mineralsin Fowden et al.[24].Clay minerals areand layered crystalline substances thatweathering of certain rock formingicates of aluminium and other metallictially two fundamental crystal layers,alumina(octahedral).It is basically theare stacked together with differentthe crystal lattice that differentiates clayite,illite and montmorillonite from onegeological conditions and prevailingmine which type of clay is formed.Clay minerals are commonly found in75l m material)of natural aggregates.ically less than2l m in size,but can be10sized clay materials and their unit cellsative charges on their surfaces.Whenbetween clay particles gets occupied byThe simultaneous presence of negativelyand the dipoles of water create electro-tract and hold the dipoles of water.Claymulti-layer formations.The chargedcharge around the particles are togetherlayer[39].The space between layers and the freeinterlayer space are the chief reasons formineral has a swelling behaviour.Theabsorption of water dipoles to theto be achieved.With decreased interlayeramong the layers become powerful and of water,so swelling does not occur.Conversely,as the interlayer space becomes more signiﬁcant,interlayer forces are so that water absorption in the interlayer space can progress until interlayer bonds fail.Hence,the clay particles get separated and rearranged and swelling occurs.The extent and kinetics of the mechanisms de-scribed above depend on several other parameters acting individ-ually or in combination.These include the density of the surface charge,the type and valence of the cations,the concentration of the electrolytes and the dielectric constant.Therefore,swelling depends on the type of clay mineral.Gener-ally,smectite minerals,with montmorillonite being a chief repre-sentative of this group,are considered swelling.Such smectites encompass repeat units of silica,gibbsite(aluminium hydroxyl groups)and adjacent silica layers joined by Van der Waals bonds (Fig.1).The substitution of aluminium for magnesium in the gibb-site layer and for silicon in the silica layer results in a net negative charge in smectites,thus imparting a high cation exchange capac-ity.In addition to their high cation exchange capacity,the inter-layer spacing between silica layers can increase in smectites through water absorption,causing substantial swelling.Con-versely,clay minerals such as pyrophyllite,margarite and illite are considered non-swelling.For instance,kaolinites comprise re-peat units of silica and gibbsite and lack the inter-layer spacing found between adjacent silica layers in smectites.Hence,their cat-ion exchange capacity is less than that of smectites and is predom-1.Schematic illustration of the layered structure present in montmorillonite (courtesy of J.Plank,2013).M.L.Nehdi/Construction and Building Materials51(2014)372–382373d-spacing when exchangeable cations are hydrated by an aqueous solution[7].The presence of clay minerals in coarse andﬁne aggregates can have remarkable effects on the workability of fresh concrete,effec-tiveness of chemical admixtures,and on the mechanical strength, dimensional stability and durability of hardened concrete.There-fore,it is paramount to determine the type and content of clay minerals in aggregates,develop rapid and reliableﬁeld test meth-ods to quantify deleterious clay minerals in aggregate stockpiles and recommend remedial techniques,if any,to make the clay-con-taminated aggregates adequate for use in concrete.In this article,a critical overview of the effects of clay minerals in cement-based materials is provided.The test methods used to assess the presence of clay in aggregates are examined,and inter-national standards on clay minerals in concrete are highlighted. The problem of dimensional stability of aggregates bearing clay minerals is discussed.Possible chemical treatment of clays to mit-igate their detrimental effects in concrete is also outlined.Finally, emerging research on using nano-clays in cement-based materials is highlighted.It is hoped that this critical analysis of international literature could mitigate existing ambiguity on the topic of clay in concrete among engineers and practitioners.3.Mechanisms of clay swellingThe mechanisms of clay swelling have been extensively dis-cussed in the literature.Only aspects relevant to clays in cement-based materials are considered herein.Much of this discussion is based on a review by Anderson et al.[8].In contact with water, exchangeable cations in the clay interlayer space tend to hydrate, forcing clay layers apart.Swelling can occur via two different re-gimes;crystalline and osmotic swelling.Crystalline swelling can occur in all types of clay minerals.This was shown to be a short-range swelling occurring in a discrete fashion,through the stepwise formation of mixtures of interlayer hydrates.Several layers of water molecules line up to form a qua-si-crystalline structure between unit layers resulting in an in-creased interlayer spacing.For instance,smectite clays absorb water and form one-,two-,three-and four-layer hydrates.The equilibrium layer spacing for a certain clay mineral is the state whereby the thermodynamic potential(free energy)is a global minimum given thermodynamic constraints of temperature,pres-sure,and water chemical potential(Anderson et al.[8]).Typical interlayer spacing recorded in the crystalline swelling regime ranges from9to20Å.Osmotic swelling occurs in particular clay minerals known to contain exchangeable cations in the interlayer region.When the concentration of cations in the interlayer space is higher than that in the surrounding solution,water molecules migrate into the interlayer space to restore cation equilibrium.This type of swelling can cause appreciably larger volume increases(interlayer spacing of20–130Å)than that resulting from crystalline swelling.For in-stance,smectites can swell in this osmotic fashion.Conversely, K+saturated smectite clay do not swell in this manner and form crystalline hydrates even in aqueous suspension[52].Thus,the K+ion can be used to prevent the swelling of sodium saturated clay minerals(Anderson,2010).The type,size and charge of exchangeable cations present in the clay interlayer space have a predominant effect on the magnitude of clay swelling.Water desorption isotherm measurements of montmorillonite intercalated with different monovalent exchange-able cations(Li+,Na+,K+,Rb+and Cs+)indicated that for larger cations,less water is adsorbed[40].Clay minerals incorporating monovalent cations having larger hydration energies tend to swell more than those containing cations with lower hydration energies.Furthermore,the type of substitutions present and layer charge of a clay mineral can signiﬁcantly inﬂuence its swelling characteris-tics.This is discussed in greater detail in Anderson et al.[8].4.Effects of clay on properties of concreteThere has long been concern that clay particles may be harmful to concrete because of their ability to absorb water and swell, which increases the water demand in fresh concrete.As early as 1933,Parsons[48]studied the effects of partially substituting clay for either10%by volume of cement or7.5%by volume ofﬁne aggregate,on the compressive strength,absorption,and perme-ability of concrete.Three different clays were used:red surface clay from Occoquan,blue clay from Baltimore,Maryland and yellow clay from Alexandria,Virginia,It was believed the clays were free from organic matter as they were used in brick manufacturing.It was observed that substituting10%of clay for cement by volume caused around0–10%decrease in compressive strength at ages be-yond three months,but there was no appreciable effect on perme-ability.Also,substituting clay for7.5%ofﬁne aggregate increased compressive strength by up to37%.The effects of clay on the water absorption,permeability,and resistance to freezing and thawing cycles of concrete were not signiﬁcant.In1934,Lyse[37]reported that experimental work at Lehigh University supported the claim that severe limits on the contents ofﬁnes in concrete were unnec-essary and even could become illogical when chemical admixtures are permitted.More recently,Solomon and Ekolu[60]investigated the incor-poration of clay soil into concrete mixtures as a means of making low-cost,low-strength construction materials for infrastructure in developing countries.Four control concrete mixtures with 350kg/m3of cement and water-to-cementitious content(w/cc)ra-tio of0.70,0.75;and with280kg/m3cementitious content with w/ cc=0.80and0.85were tested.Further mixtures had10%,20%,30%, 40%,and60%partial substitution of cement with local raw clay.It was found that clay–cement concrete mixtures with a maximum w/cc=0.80and20–30%clay replacement for cement can be suited to fulﬁl the strength and workability requirements for low-cost, low-strength applications including housing,roads and dams.Olanitori[47]reported that the higher the clay and silt content in sand,the higher was the cement dosage increment needed to maintain the compressive strength of concrete beyond20MPa, which is the value generally speciﬁed at28-d in Nigeria for a mix-ture ratio1:2:4.He recommended carrying out a comparative cost analysis between the cement dosage increments used for sand with a particular clay/silt content,and washing the sand to reduce the clay/silt content,so as to determine which is more cost-effec-tive to maintain20-MPa compressive strength.Li et al.[32]studied the workability,strength and modulus of elasticity,drying shrinkage and creep,freeze–thaw resistance and chloride ion permeability of C60high-performance concrete (HPC)made with manufactured sand(MS)containing 3.5–14% crushed limestone dust,versus that made with river sand(RS)with clay amounts of3%and5%.The clay content in MS decreased work-ability,increased drying shrinkage and accelerated freeze–thaw damage of the C60-HPC,but did not affect its compressive strength and chloride ion permeability.It was concluded that C60-HPC can be made with MS with a high content of crushed limestone dust, but the amount of clay in MS should be controlled.Norvell et al.[46]explored the effects of clay minerals present in natural aggregates versus that of clay-sized particles present in manufacturedﬁne aggregates on concrete performance by‘‘dop-ing’’micro-ﬁne aggregates with clay minerals and non-clay con-taining particles of similar size.Speciﬁcally,they investigated the effects on water demand,water-reducing admixture demand,374M.L.Nehdi/Construction and Building Materials51(2014)372–382compressive strength and drying shrinkage.It was concluded that clays do increase the water and superplasticizer demand in accor-dance with their interlayer absorption and cation exchange capac-ity,respectively(Table1).However,clay-sized particles(particles of similar size to clay but with different mineralogy)did not signif-icantly affect the water and superplasticizer demands at the levels studied.At constant w/c,only smectite(montmorillonite)clay was found to decrease compressive strength and to increase drying shrinkage.Li et al.[33]explored the effects of the clay content and charac-teristics,methylene blue value(MBV ranging from0.35to2.5)of manufactured sand(MS)and the limestoneﬁnes content on the performance of concrete.Results showed that with an increase in MBV,the workability,ﬂexural strength and7-d compressive strength of the MS concrete decreased,while the28-d compressive strength was not affected.Also,increasing MBV enhanced plastic and drying shrinkage cracking of the concrete and remarkably accelerated its freeze–thaw damage and abrasion loss.It was con-tended that the critical MBV was1.4;a value below which the per-formance of MS concrete is not signiﬁcantly compromised by the presence of clay.Since different speciﬁcations and code provisions deﬁne various limits for theﬁne impurities content of the concrete coarse aggre-gate,Seleem and El-Hefnawy[56]evaluated the effects of different levels ofﬁne impurities normally found in coarse aggregates in Egypt on the compressive strength and dimensional stability of concrete.Based on their test results,a higher limit ofﬁne impuri-ties(5%)in coarse aggregate was suggested,particularly when the increase in shrinkage is overcome using a superplasticizer and low-er water-to-cement-ratio.Chan and Wu[14]argued that research has shown silts and clays to be deleterious because in the mixing of concrete con-taining silts and clays more water is added to achieve adequate workability.They reasoned that the use of a superplasticizer at similar w/c ratio to that of a control OPC concrete not containing silts and clays may provide good quality concrete.They con-ducted trial concrete mixtures with particles less than150l m in size consisting of silts and clays obtained from crushed gran-ite stone along with a sulphonated naphthalene superplasticizer. They concluded that durable concrete could be made with25% partial replacement of cement with silt and clay using a w/c ra-tio of0.5.However,Chan and Wu[14]explored workability, strength and permeability of the silt and clay concrete,but did not assess its dimensional stability,abrasion and freeze–thaw resistance.Courard et al.[18]investigated the effects of various limestone ﬁllers on the fresh and hardened properties of self-compacting mortars.Six different limestoneﬁllers were used at15%,25%and 35%partial mass replacement of cement.Theﬁllers incorporated clays and had methylene blue absorption values between0.7and 5.0.Among the sixﬁllers,two contained swelling clays.It was found that the water requirement of limestoneﬁllers was primar-ily affected by their content of swelling clay.The water require-ment had a direct correlation with the methylene blue absorption and the BET speciﬁc surface of theﬁllers.The consis-tency of fresh mortars decreased with increasing swelling clay con-tent of the limestoneﬁllers.It was argued that despite the effect on fresh mortar properties,no major inﬂuence of clays on the behav-iour of hardened mortars was observed.Even the swelling clays did not hinder the porosity of limestoneﬁller modiﬁed mortars.It was contended that should superplasticizers be used to solve rheologi-cal problems,ﬁllers from the aggregate industry and stone sawing could be used in concrete manufacturing.Fernandes et al.[22]carried out an experimental study on clay–cement–sand composites.They compared the effects of pure quartz sand to that of two synthesized sands made by dry mixing of this pure sand with either20%by mass of kaolin or20%by mass of montmorillonite.They made various mortars with Type I OPC and variable sand types,water/cement ratios and sand/cement ratios.The28-d compressive strength was measured and X-ray diffraction was employed to examine whether any reactions between the clay and cement had oc-curred.A linear relationship existed between the amount of clay and corresponding amount of water needed to maintain certain workability.XRD analysis did not identify any secondary prod-ucts forming in the presence of clay.Moreover,the mixtures incorporating kaolin clay followed similar strength-w/c relation-ship to that of normal concrete,with lower strengths attributed to increased water demand and/or increased compaction difﬁ-culty,while those including montmorillonite followed a different relationship,suggesting that this clay had other deleterious ef-fects beyond the increased water demand.It was postulated that for the typical w/c and strength values of building materials in developing countries,satisfactory mortar and blocks can be made from clay-contaminated sand.However,the effect of the type of clay is signiﬁcant and structural concrete made with such materials needs proper durability and dimensional stability investigation.The effects of coarse aggregate coatings on concrete proper-ties were explored by Muñoz et al.[43].Seven concrete mixtures were made with coarse aggregates containing two types of coat-ings:naturalﬁeld-coated aggregates,and manufactured coated samples of dust and clayﬁnes.The effects of these coatings on concrete performance were examined by comparing the relative changes in physical and mechanical properties of the concrete versus that of a control concrete made with washed aggregates. It was concluded that microﬁne coatings on coarse aggregates can inﬂuence the properties of fresh and hardened concrete even when their amount in the passing No.200sieve is less than 1.5%.The extent and nature of such inﬂuence depend on the quantity and type of the microﬁne.Thus,ASTM C117,which only accounts for the quantity of micro-ﬁnes present in the aggre-gates,was not considered an adequate monitoring tool for this problem.It was suggested that the product of MBV(methylene blue value)and P200(maximum percentage of material passing the No.200sieve),referred to as the MMBV was the best overall predictor.Table1Water and admixture demand with clay minerals and non-clay sized minerals (modiﬁed after[46].Type of Mineral Waterdemand Superplasticizer dosage (w/c=0.42)Control:granite sand0.47 4.5Clay mineral1%Kaolinite0.50 6.04%Kaolinite0.608.01%Illite0.49 5.54%Illite0.5110.01%Montmorillonite0.6218.54%Montmorillonite0.90186.0Clay sized particles1%Fine calcium carbonate(60%<2l m)0.48–4%Fine calcium carbonate(60%<2l m)0.48 4.01%Ultraﬁne calcium carbonate(90%<2l m)0.49–4%Ultraﬁne calcium carbonate(90%<2l m)0.49 4.01%Ground silica(96%<5l m)0.47–1%Ground silica(96%<5l m)0.47 2.5M.L.Nehdi/Construction and Building Materials51(2014)372–3823755.Effects of clay on chemical admixturesIt is believed that their ability to readily exchange cations is the most deleterious feature of clays in concrete.Cations are ex-changed in order to balance inherent electrical charges on the sur-face of clay particles.Such cations can be readily exchanged with organic materials such as water-reducing admixtures and superp-lasticizers.This high afﬁnity to organic substances competes with the adsorption and dispersing mechanisms of chemical admixtures at the surface of cement and supplementary cementitious materi-als particles.Subsequently,as clay particles consume part of the chemical admixture,a higher dosage will be required to achieve certain workability.This not only has cost implications,but the very high admixture dosage can lead to excessively long setting time,delays in strength gain and formwork removal.Table1exhib-its the substantial effect observed by Norvell et al.[46]of swelling clay on the superplasticizer demand of concrete.In particular,there has been growing evidence that polycarbox-ilate-based superplasticizers(PCEs)are more sensitive to clays than poly-condensate superplasticizers.This is primarily due to their incorporation into the layered clay structure via their side chains,which impedes their dispersing ability.It was observed by several researchers(e.g.[55,31]that different types of PCEs show pronounced sensitivity to clay and their dispersing force de-creases signiﬁcantly in its presence.The predominantly used side chain in PCE superplasticizers is poly(ethylene oxide),which is known to easily intercalate within alumosilicate layers of clays (e.g.[36].Montmorillonite(MMT)was found to be particularly harmful to concreteﬂuidity compared to other clay minerals such as kaolinites(e.g.[27].This is caused by the expanding lattices of MMT,allowing intercalation,swelling and cation exchange[38].Li et al.[34]studied the inﬂuence of clay on the disperse-ability of polycarboxylate superplasticizers.They investigated theﬂuidity and viscosity of cement paste and examined the inﬂuence of clayﬁltrate on the molecular structure and kinetics of adsorption of PCE on the surface of clay particles in a simu-lated alkaline environment consisting of saturated calcium hydroxide solution.Theirﬁndings indicate that PCE has no dis-persing effect on cement paste once the clay content reached 15%.Increasing the PCE dosage mitigated this negative effect of clay.Moreover,it was found that the clayﬁltrate did not change the molecular structure of PCE nor did it affect its disperse-abil-ity.The kinetics of clay adsorption in the simulated alkaline environment on PCE was rapid,with an adsorption capacity about4times that on cement,with clay reaching its equilibrium adsorption within6min.Ng and Plank[44]tested PCEs consisting of methacrylic acid/ MPEG methacrylate-ester with molar ratios of6:1and1.5:1.They found that the tested PCEs sorb chemically and physically onto clay by amounts about100times higher than that on cement.Chemi-sorption appeared to take place via intercalation of the poly(ethyl-ene oxide)side chains into the interlayer region between alumos-ilicate layers,while physic-sorption occurred on positively charged clay surfaces through uptake of Ca2+.The type of sorption was dos-age dependent,with side chain intercalation dominating at higher PCE dosage,while electrostatic attraction via the clay surfaces an-ionic backbone prevailed at lower dosage.Since PCEs possessing high grafting density were more vulnerable to clay effects,it was argued that poly-glycols can be utilised as sacriﬁcial agents when highly grafted PCEs are employed at high dosages.Lei and Plank[31]asserted that new PCE superplasticizers pos-sessing modiﬁed chemical structure for enhanced robustness to-wards clay need to be developed.Hence,they synthetized modiﬁed PCEs from methacrylic acid and hydroxyl-alkyl methac-rylate esters and tested their dispersion performance in cement with and without montmorillonite clay.The new PCE was found to disperse cement effectively in the presence of clay and was much less affected by clay than conventional PCEs.A mechanistic study including adsorption and XRD experiments revealed that the new PCE only adsorbs on the surface of clay and does not incor-porate into its layered structure,which explains its tolerance to clay contamination.6.Expansion of aggregates with clay bearing mineralsThe dimensional stability of aggregates versus moisture changes has been discussed in detail by Shayan[59].Generally, dense and un-weathered aggregates are not affected by changes in moisture content.Their water absorption is generally less than 1%by mass of rock.Hence they usually retain their dimensions un-der wet or dry conditions.However,some vesicular rocks may ex-hibit high water absorption,yet can remain dimensionally stable provided they are free of expansive clay minerals.Once altered or weathered,rocks can exhibit expansive minerals,yielding high water absorption due to the ability of clay minerals to accommo-date water in its interlayer spaces.The formation of expansive clay minerals has been reported by several authors in basaltic rocks and in granophyre(e.g.in[59];its effects on the properties of the rock as a source of concrete aggregate have also been well documented.Water absorption by clay minerals in aggregates can cause expansion of the granular matrix,hence causing expansion of the concrete.Drying can exhibit excessive shrinkage,possibly leading to cracking,especially under repeated wetting/drying conditions (e.g.[16,54].Water vapour and nitrogen absorption studies and measurements of internal and external surface area of basalts (e.g.[16,58]revealed a direct relationship between the length change of rock prisms subjected to wetting/drying cycles and their clay content.Similar relationships have also been established for granophyre and basalt[58,67].The dimensional stability and moisture sensitivity of rocks can be experimentally measured on prism specimens subjected to re-peated wetting–drying cycles and monitoring the associated length changes using accurate length measurement comparators (e.g.[16,57].Some indirect methods including correlating drying shrinkage with moisture absorption of aggregate or with adsorp-tion of other polar molecules such as methylene blue dye,have been used to predict the drying shrinkage of aggregates[59].In particular,the MBV value had a reasonable correlation with the clay content of tested materials and was successfully used to eval-uate a source rock for drying shrinkage before the development of a quarry at the site[57].Using124test specimens,a correlation was developed by Sha-yan[57]between drying shrinkage of aggregate and its MBV value. It was shown that MBV levels beyond1.75ml/g were associated with unacceptable aggregate drying shrinkage.Table2lists typical ranges of moisture-induced length changes measured on different rock prisms from Australian aggregate source rocks and reported by[59].It can be observed that andesitic tuffs,grey basalts and sandstones undergo signiﬁcant length changes upon wetting and drying,at times exceeding1000micro-strains.Except grey basalt, substantial dimensional instability in rocks has been linked to higher clay content.Likewise,when clay occurred in the form of an interconnected network in basalt(e.g.[17]or in the form of veins in granophyre(e.g.[57],the length change was much larger than when a similar amount of clay was present in isolated patches or in vesicles.7.Test methods for clay in cement-based materialsConsidering the signiﬁcant inﬂuence of the type and content of clay on the water and chemical admixture demand,mechanical376M.L.Nehdi/Construction and Building Materials51(2014)372–382。

2016新编磨削技术英文翻译

Grinding technology development trendGrinding machining is important processing technology in mechanical manufacturing. With precision mechanical products, the requirement of increasing the reliability and service life, high hardness, high strength, high wear resistance, high functional new materials application increased, for grinding processing and put forward many new problems, such as material of grinding machining and surface integrity, super precision grinding and high efficiency grinding and grinding automation, etc. Problems to be solved.At present, the grinding technology is moving toward using super hard abrasives, development of precision and ultra precision grinding, high speed, high efficiency grinding technology and the development of high precision, high stiffness of the grinding machine automation direction.One. In-depth development of grinding theory and technology research Grinding theory research is the basis for the development of grinding technology, thegrinding technology and the development of practice and research provides the opportunity for grinding theory, requirement and new topic, in recent ten years, professionals engaged in the work of grinding, grinding technology and phenomenon many factors for a lot of in-depth research and achieved fruitful results.Two. Unit grinding machine high speed, high precision components manufacturing technologyHigh precision grinding machine spindle unit, feeding unit, bearing unit and auxiliary unit is the key parts and components. Spindle unit including spindle power, shaft, bearing, and frame sections, she affects the precision of the machining system, stability and application scope, its dynamic performance and stability of high performance precision ultra-precision grinding, play a key role. Feed unit including the position detection unit, Demand of feed units, therefore, flexible operation, high resolution, high positioning accuracy, not crawl and large movement range, both to have larger acceleration, and large enough thrust, high stiffness, quick dynamic response, high positioning accuracy. Machine tools supporting technology mainly refers to the supporting member of design and manufacturing technology. Auxiliary unit technology including fast clamping workpiece, high efficiency grinding fluid filtration system, machine safety devices, chip removal and the workpiece cleaning technology, spindle and grinding wheel dynamic balance technology, etc.Three. Grinding automation and intellectualizationWith mechanical manufacturing in FMS (flexible manufacturing system) andCIMS (computer integrated manufacturing system), IMS (intelligent manufacturing system) height automation development direction, the grinding automation requirements are put forward. The development of the CNC grinding machine with CNC lathe, milling machine and so on started late. In the 1980 s and 90 s is a CNC grinding machine for rapid development and entered the popularizing period of practical. In recent years, almost all kinds of grinder CNC products, CNC tool grinding machine from 3 to 10 shaft axis development. Which can realize online measurement, automatic switching of grinding wheel and the emergence of the automatic unloading workpieces milling machining center, mark CNC grinding reached a new level. Grinding CNC system development also have great progress, many special grinding CNC software and systems have been commercialized. In the 1990 s, Japan announced about intelligent grinding results. Use of monitoring information and database, adaptive optimization in grinding condition and the judgment condition of grinding, using computer simulation and virtual technology, establish a realistic virtual grinding environment, to implement the intelligent of the grinding. Continuous track the use of grinding technology, making the grinding technology has made great development.Four. Grinding process monitoring and detection technologyImplementation of intelligent computer control of grinding, grinding process is an important problem in the control room. Solve the grinding process, such as the phenomenon of signal identification, signal sampling, signal processing, feedback and compensation, need high sensitive sensor, also need to have expert system or intelligent system and the software design and other technical support.For grinding wheel wear and tear of using acoustic emission monitoring system. Because of the complexity of the grinding process, the grinding process of the monitoring system in theory and practical aspect still has many problems unsolved. Parts after the grinding size, shape and position accuracy, surface quality of the test is divided into offline and online detection.For super precision grinding and free abrasive machining high precision and low surface roughness obtained after detection, high-precision grinding on the surface of the on-line automatic detection are much harder than cars, milling, high sensitivity is the key to development of sensor technology and signal acquisition, recognition and processing technologies.Five. Software of grinding technologyHigh performance CNC grinding machine should be equipped with a complete software system. Of intelligence information processing and data input of grinding, grinding mode selection and grinding the arrangement of the order, condition of grinding, grinding wheel dressing and grinding automatically selected, the state of the grinding process simulation and virtual detection and compensation, are in softwaredesign and development of a reasonable solution.All countries in the development of expert system and intelligent system software. Expert system is a branch of artificial intelligence research, and its essence is a kind of application system. Problem solving ability with expert level in the field of grinding process system, can effectively solve complex problems in the field of grinding.磨削加工技术发展趋势磨削加工是机械制造中重要的加工工艺。

MethylationAnaly...

Methylation Analysis by Restriction EndonucleaseDigestion and Real-Time PCRRong Mao 1,2,3*and Lan-Szu Chou 1DNA methylation is a highly characterized epigenetic modification of the human genome that is critical for normal cell processes,including tissue regulation,ge-netic expression development,genomic imprinting,X-chromosome inactivation,and DNA repair.DNA methylation in humans occurs almost exclusively at the C5position of CpG dinucleotides in genomic pro-moter regions.Alterations in DNA methylation cause developmental diseases,such as genetic imprinting defects,cancer,and potentially a wide range of adult-onset chronic diseases.Therefore,sensitive techniques that detect methylation are critical for epigenetic re-search,clinical diagnostics,cancer prognosis,and therapeutics (1,2).Methylation-specific PCR is a commonly used rapid technique for methylation screening that re-places the laborious Southern blot assay,the standard procedure on which most DNA analysis is based.Methylation-specific PCR and other PCR-based meth-ylation methods that use bisulfite-treated DNA as a template are generally accepted as the most analytically sensitive and specific techniques for analyzing DNA methylation at a single locus.The protocol described by Frommer et al.has been widely used for sodium bisul-fite modification,and a variety of commercial kits are available for this purpose (3).Sodium bisulfite deami-nates unmethylated cytosine to uracil,and the methyl-ation is accessed by the PCR with either methylation-specific primers or methylation-independent primers (MIPs).4Methylation-specific primers amplify either methylated or unmethylated alleles.These primers are highly sensitive and able to detect the presence of a methylated allele at a frequency as low as 0.1%in an unmethylated population (4).PCR with methylation-specific primers is not quantitative,however.Alter-natively,the MethyLight method is a sensitive,fluorescence-based real-time PCR technique capable of quantifying DNA methylation at a specific locus (5,6).MethyLight can detect completely methylated or unmethylated alleles but is oblivious to partially methylated CpGs.Considering the random conversion of cytosine to uracil,it is possible that a subset of DNA copies have a substantially lower conversion rate and that some promoter regions might prove more prone to incomplete conversion than others,thereby leading to the disregard of several partially methylated alleles.Therefore,MethyLight,despite being a quantitative as-say,cannot distinguish different methylation patterns.MIP-PCR uses primers designed for universally amplifying proportional methylated and unmethyl-ated alleles that include a number of CpG sites.Because of their GC content,the methylated and unmethylated alleles are distinguished by high-resolution melting analysis,which exploits differences in thermal stability (7).This PCR has a tendency to amplify unmethylated DNA,because of the low GC content after bisulfite modification of the DNA.The sensitivity of MIP-based methods is relatively low,but it can be increased by introducing CpG sites into the primers or by using oli-gonucleotide blockers.Nonetheless,these assays can measure methylation quantitatively and estimate the mosaic situation.Several other MIP-based methods also have been successfully used for methylation anal-ysis,such as methylation-sensitive single-nucleotide primer extension and combined bisulfite restriction analysis (8).Methylation-specific multiplex ligation-dependent probe amplification (MS-MLPA)uses multiple probes that are hybridized to their targeted methylation sites.The methylation sites are recognized by a methylation-sensitive restriction enzyme (Hha I),and the probe pair is ligated in the ligation reaction (9).This method not only permits simultaneous analysis of multiple meth-ylation sites but also allows quantification of copy number changes by comparing target-specific probes to the control probes (10).Bisulfite Sanger sequencing,considered the gold standard for methylation analysis,provides informa-tion about individual CpG sites.In addition to requir-ing laborious processes to implement,the Sanger sequencing approach has a sensitivity for detecting low-level mosaicism that is limited to 20%.An attrac-tive alternative is pyrosequencing.Pyrosequencing is1Institute for Clinical and Experimental Pathology,ARUP Laboratories,Salt Lake City,UT;2ARUP Laboratories,Salt Lake City,UT;3Department of Pathology,University of Utah Health Science Center,Salt Lake City,UT.*Address correspondence to this author at:ARUP Laboratories,500Chipeta Way,Salt Lake City,UT 84108-1221.E-mail ********************.Received April 12,2010;accepted April 27,2010.Previously published online at DOI:10.1373/clinchem.2010.1466544Nonstandard abbreviations:MIP,methylation-independent primer;MS-MLPA,methylation-specific multiplex ligation-dependent probe amplification;qPCR,quantitative PCR;C q ,quantification cycle.Clinical Chemistry 56:71050–1052(2010)Editorials1050a sequencing-by-synthesis technology that lumino-metrically detects pyrophosphate released via an en-zyme cascade during synthesis.With a read length of 25–30bp,pyrosequencing methylation analysis relies on bisulfite conversion and yields quantitative infor-mation on single CpG sites(11).Although the bisulfite modification–based meth-ods described above perform acceptably in many sce-narios,their use of multiple chemical reactions to con-vert cytosine to uracil requires a purification process after the conversion,thus leaving room for contamina-tion during the many steps.Therefore,there is a need for a better method that is rapid,highly sensitive,and cost-effective and that has both a low false-negative rate and a low risk of contamination.In this issue of Clinical Chemistry,von Kanel et al.describe a novel quantitative real-time PCR assay that detects DNA methylation in a1-step,single-tube reaction(12).This PCR uses untreated genomic DNA as a template,thus eliminating the use of a bisulfite-conversion process and its considerable drawbacks,which include incom-plete bisulfite reactions(13).The advantages of the approach of von Kanel et al.include the use of a single-tube reaction that combines a rapid methylation-sensitive restriction endonuclease digestion and a quantitative PCR(qPCR),thus decreasing both hands-on time and possible cross-contamination.It also provides a short turnaround time(an important factor from a diagnostic laboratory’s perspective),a relatively low cost,the flexibility to design a real-time PCR-based assay,and the use of a model for correcting results obtained with low-quality DNA,such as that in formalin-fixed,paraffin-embedded tissue samples, which are usually degraded or possess some PCR inhibitors.The single-tube reaction described by von Kanel et al.is performed in a glass capillary–based LightCycler instrument(Roche Applied Science)within90min by incubating with the methylation-sensitive FastDigest௡Hpa II enzyme(Fermentas Life Sciences)at37°C for10 min to digest the genomic DNA template and then at5 min at95°C to inactivate the Hpa II enzyme and acti-vate the Taq polymerase.This step is followed by40 cycles of a real-time PCR reaction at an annealing tem-perature of60°C(15s)for both the SNRPN5(small nuclear ribonucleoprotein polypeptide N)locus(tar-get)and the CFTR[cystic fibrosis transmembrane con-ductance regulator(ATP-binding cassette sub-family C,member7)]locus(control for DNA digestion and reference for copy number analysis).Performing thesham reactions allows measurement of the methylationstatus(as a percentage)with the default second deriv-ative maximum method of the LightCycler for deter-mining the quantification cycles(C q s)with and with-out the Hpa II digestion.In addition,the⌬⌬C q method(14)is used to evaluate the copy number of the SNRPNpromoter by obtaining the C q s from the sham reactionsof the patient samples and the calibrator(DNA with aknown copy number status).This copy number analy-sis is independent of DNA digestibility.With this1-step,single-tube approach,von Kanel et al.have val-idated a set of blinded samples(from12patients withPrader–Willi syndrome,12patients with Angelmansyndrome,and11unaffected individuals)and found100%concordance with the previously obtained geno-typic data(by methylation-specific PCR followed bydenaturing HPLC and microsatellite analysis)for bothmethylation status and copy number change.To further minimize the impact of low DNA qual-ity on the quantitative assessments caused by the inef-ficient digestion,this study also investigated an addi-tional14DNA samples with reduced digestibility andprovided a correction model,with the CFTR locusused as a control[i.e.,CSML3ϭMM SNRPN patϪMM CFTR patϫ(MM SNRPN cal/MM CFTR cal)ϫ(1ϪCSML2/100)][see Eq.5in the report by von Kanel et al.(12)].This model corrects the measured percentage ofmethylation to more closely match the theoretical val-ues(0%,50%,100%)when DNA samples of both goodquality and reduced digestibility are e of thisequation requires that DNA with a known methylationstatus be included in the experiment as a calibrator.Furthermore,this study also used the linear relation-ship observed between the theoretical and measuredDNA methylation levels during assay validation to de-termine the percentage of mosaicism in the tested sam-ples from patients with Prader–Willi syndrome andAngelman syndrome.Considering this report’s thorough analysis of pa-rameters that may affect the performance of real-timePCR assays,including different types of DNA samples,several outstanding issues remain to be addressed.First,in addition to initial DNA quality and the methodused for DNA extraction,what often affects the robust-ness(performance)and the throughput of a real-timeqPCR assay is the selection of the proper referencegene(s)for better quantitative assessment.When thismethod is expanded to analyze multiple methylatedloci simultaneously,it is necessary to determinewhether the same single reference gene(CFTR)can beused or whether a“reference panel”of genes is neededfor better quantitative assessment.MS-MLPA certainlyrequires a relatively longer hands-on time(estimated at10min for the first day of hybridization setup and455Human genes:SNRPN,small nuclear ribonucleoprotein polypeptide N;CFTR,cystic fibrosis transmembrane conductance regulator(ATP-binding cassettesub-family C,member7).EditorialsClinical Chemistry56:7(2010)1051min on the second day to finish digestion/ligation be-fore the PCR and fragment analysis),but it analyzes multiple loci simultaneously and uses multiple built-in reference genes in the same reaction/sample/run,mak-ing the data-analysis portion of the assay relatively easy and robust for assessing both DNA methylation status and copy number change.Second,although this 1-step,single-tube qPCR assay has been proposed for measuring the mosaicism percentage,it has not ad-dressed fully the calculation of mosaicism.A larger sample size is needed to better establish the legitimacy of this proposed feature.Ultimately,the method von Kanel et al.have de-veloped provides a rapid,efficient,and accurate quan-titative assessment of both DNA methylation status and copy number change at a single locus,with the added benefit of determining the percentage of mosa-icism.Quantification of the methylation sites can be achieved with real-time PCR,and a closed-tube assay avoids potential cross-contamination.This novel 1-step,single-tube qPCR method fulfills the require-ments of being a more cost-effective,efficient,and thorough assay,which can be readily implemented in a diagnostic setting to improve patient services.Author Contributions:All authors confirmed they have contributed to the intellectual content of this paper and have met the following3re-quirements:(a)significant contributions to the conception and design, acquisition of data,or analysis and interpretation of data;(b)drafting or revising the article for intellectual content;and(c)final approval of the published article.Authors’Disclosures of Potential Conflicts of Interest:No authors declared any potential conflicts of interest.Role of Sponsor:The funding organizations played no role in the design of study,choice of enrolled patients,review and interpretation of data,or preparation or approval of manuscript.References1.Esteller M.Epigenetics in cancer.N Engl J Med2008;13:1148–59.2.Lewis A,Reik W.How imprinting centres work.Cytogenet Genome Res2006;113:81–9.3.Frommer M,McDonald LE,Millar DS,Collis CM,Watt F,Grigg GW,et al.Agenomic sequencing protocol that yields a positive display of 5-methylcytosine residues in individual DNA strands.Proc Natl Acad Sci U S A1992;89:1827–31.4.Herman JG,Graff JR,Myöha¨nen S,Nelkin BD,Baylin SB.Methylation-specificPCR:a novel PCR assay for methylation status of CpG islands.Proc Natl Acad Sci U S A1996;93:9821–6.5.Lo YM,Wong IH,Zhang J,Tein MS,Ng MH,Hjelm NM.Quantitative analysisof aberrant p16methylation using real-time quantitative methylation-specific polymerase chain reaction.Cancer Res1999;59:3899–903.6.Eads CA,Danenberg KD,Kawakami K,Saltz LB,Blake C,Shibata D,et al.MethyLight:a high-throughput assay to measure DNA methylation.Nucleic Acids Res2000;28:E32.7.Wojdacz TK,Dobrovic A,Hansen LL.Methylation-sensitive high-resolutionmelting.Nat Protoc2008;3:1903–8.8.Kristensen LS,Hansen LL.PCR-based methods for detecting single-locus DNAmethylation biomarkers in cancer diagnostics,prognostics,and response to treatment.Clin Chem2009;55:1471–83.9.Nygren AO,Ameziane N,Duarte HM,Vijzelaar RN,Waisfisz Q,Hess CJ,et al.Methylation-specific MLPA(MS-MLPA):simultaneous detection of CpG methylation and copy number changes of up to40sequences.Nucleic Acids Res2005;33:e128.10.Procter M,Chou LS,Tang W,Jama M,Mao R.Molecular diagnosis ofPrader–Willi and Angelman syndromes by methylation-specific melting anal-ysis and methylation-specific multiplex ligation-dependent probe amplifica-tion.Clin Chem2006;52:1276–83.11.Tost J,Dunker J,Gut IG.Analysis and quantification of multiple methylationvariable positions in CpG islands by Pyrosequencing.Biotechniques2003;35:152–6.8.12.von Kanel T,Gerber D,Schaller A,Baumer A,Wey E,Jackson CB,et al.Quantitative1-step DNA methylation analysis with native genomic DNA as template.Clin Chem2010;56:1098–1106.13.Chan KC,Ding C,Gerovassili A,Yeung SW,Chiu RW,Leung TN,et al.Hypermethylated RASSF1A in maternal plasma:a universal fetal DNA marker that improves the reliability of noninvasive prenatal diagnosis.Clin Chem 2006;52:2211–8.14.Livak KJ,Schmittgen TD.Analysis of relative gene expression data usingreal-time quantitative PCR and the2Ϫ⌬⌬C method.Methods2001;25: 402–8.Editorials1052Clinical Chemistry56:7(2010)。

椭圆轨迹振动切削加工

Journal of Materials Processing Technology 214(2014)2644–2659Contents lists available at ScienceDirectJournal of Materials ProcessingTechnologyj o u r n a l h o m e p a g e :w w w.e l s e v i e r.c o m /l o c a t e /j m a t p r o t ecFundamental investigation of ultra-precision ductile machining of tungsten carbide by applying elliptical vibration cutting with single crystal diamondJianguo Zhang,Norikazu Suzuki ∗,Yilong Wang,Eiji ShamotoDepartment of Mechanical Science and Engineering,Nagoya University,Furo-cho,Chikusa-ku,Nagoya 464-8603,Japana r t i c l ei n f oArticle history:Received 19November 2013Received in revised form 30April 2014Accepted 20May 2014Available online 9June 2014Keywords:Elliptical vibration cutting Ductile machining Tungsten carbideMaterial composition Tool wear Sculpturinga b s t r a c tThis paper presents essential investigations on the feasibility of ductile mode machining of sintered tungsten carbide assisted by ultrasonic elliptical vibration cutting technology.It lays out the foundations toward efﬁcient application of elliptical vibration cutting technology on tungsten carbide.Tungsten car-bide is a crucial material for glass molding in the optics manufacturing industry.Its grain size and binder material have signiﬁcant inﬂuence not only on the mechanical and chemical properties but also on the machining performance of tungsten carbide.In order to investigate the inﬂuence of material compo-sition on tungsten carbide machining,a series of grooving and planing experiments were conducted utilizing single crystal diamond tools.The experimental results indicated that as compared to ordinary cutting where ﬁnished surface deteriorates seriously,ductile mode machining can be attained success-fully by applying the elliptical vibration cutting technique.It was also clariﬁed that the binder material,the grain size,cutting/vibration conditions as well as crystal orientation of the diamond tool have sig-niﬁcant inﬂuence on the tool life and the machined surface quality.Based on these fundamental results,feasibility of micro/nano-scale fabrication on tungsten carbide is investigated.By applying amplitude con-trol sculpturing method,where depth of cut is arbitrary changed by controlling the vibration amplitude while machining,ultra-precision textured grooves and a dimple pattern were successfully sculptured on tungsten carbide in ductile mode.©2014Elsevier B.V.All rights reserved.1.IntroductionWith the rapidly developing optoelectronics industry,demand for advanced manufacturing technology for sophisticated micro/nano structures on optical systems is increasing drastically.For example,glass lenses with small radius and large curvature have been used in various devices to miniaturize their structures and/or to attain large storage capacity.Some micro/nano optical gratings have been used in optical communication equipments,encoders,and digital cameras.In order to realize mass production of those glass devices,tungsten carbide is heavily used in molding because of its unique mechanical,thermal and chemical properties.Ultra-precision cutting has been generally applied to fabricate sophisticated micro/nano structures,and it has been widely used∗Corresponding author.Tel.:+81527894491;fax:+81527893107.E-mail addresses:nuzhjg@upr.mech.nagoya-u.ac.jp (J.Zhang),nsuzuki@mech.nagoya-u.ac.jp (N.Suzuki),wang@upr.mech.nagoya-u.ac.jp (Y.Wang),shamoto@mech.nagoya-u.ac.jp (E.Shamoto).especially for a variety of plastic molding applications.However,application of ultra-precision cutting to brittle materials is limited.Since tungsten carbide is a typically hard and brittle material,its ductile machining is extremely difﬁcult by the ordinary ultra-precision cutting technology due to generations of brittle fracture in the workpiece and excessive tool damage.Bulla et al.(2012)reported the feasibility of ultra-precision diamond turning in ductile mode on binderless,nano crystalline tungsten carbide.However,tool wear is not negligible and thus the cutting area is extremely restricted.In contrast to cutting,ultra-precision grind-ing is applicable to ductile mode machining of tungsten carbide,as reported by Yin et al.(2004).Suzuki et al.(2008)has applied the grinding technology successfully in particular applications.Suzuki et al.(2010)additionally reported that following lapping and/or polishing are also effective to achieve higher quality surface ﬁnish.However it is extremely difﬁcult to fabricate sophisticated micro/nano-scale structures especially with sharp edges by these methods.In addition,the conventional ultra-precision grinding operation is generally time-consuming as compared to cutting operation due to its complexity.These facts impose signiﬁcant/10.1016/j.jmatprotec.2014.05.0240924-0136/©2014Elsevier B.V.All rights reserved.J.Zhang et al./Journal of Materials Processing Technology214(2014)2644–26592645restrictions in practical use of tungsten carbide and deﬁne the bottleneck of ultra-precision machining of tungsten carbide.In the last few decades,ultrasonic vibration cutting technology has been successfully applied to difﬁcult-to-cut materials machin-ing,as reviewed by Brehl and Dow(2008).In particular,elliptical vibration cutting technology,which was proposed by Shamoto and Moriwaki(1994),has been the foreseen alternative to attain ultra-precision machining of hard brittle materials.Moriwaki and Shamoto(1995)developed ultrasonic elliptical vibration cutting devices,and Shamoto and Moriwaki(1999)veriﬁed the feasibil-ity of steel material machining by use of single crystal diamond (SCD)tools.Brehl and Dow(2007)challenged to create complex micro-structures by utilizing the elliptical vibration cutting tech-nology.Zhang et al.(2011)conducted further investigations on machining performance of hardened steel using polycrystalline diamond(PCD)tools.On the other hand,Suzuki et al.(2004)have applied the elliptical vibration cutting technology to machining of tungsten carbide with Cobalt binder,and its ductile machin-ing has been attained successfully by applying SCD tools.Suzuki et al.(2006)investigated the fundamental mechanism of ductile machining of tungsten carbide by applying elliptical vibration cut-ting as well.However,the tool damage has been signiﬁcant unlike hardened steel machining,and thus the cutting area was restricted to be extremely small.Nath et al.(2009a)also carried out several experimental investigations on elliptical vibration cutting of sin-tered tungsten carbide,where machinability of tungsten carbide by using PCD tools was investigated.Following this,the inﬂuence of the cutting parameters and tool radius on machined surface qual-ity was further investigated by Nath et al.(2009b).Consequently, Nath et al.(2009c)concluded that restriction in the cutting area is improved successfully by using PCD tools and a surface with roughness of less than30nm Ra was attained at the beginning of cutting.However,surface roughness deteriorates signiﬁcantly, which may not be acceptable in manufacturing of optical elements. This fact indicates that further research contribution to extend the tool life of SCD is necessary to realize practical machining of tungsten carbide by applying the elliptical vibration cutting tech-nology.On the other hand,tungsten carbide material has been studied and developed with better properties by modifying the material composition and the grain size.Material property affects machin-ing characteristics of tungsten carbide signiﬁcantly at the same time.For instance,material strength depends on the grain size and binder material,which may have chemical afﬁnity to diamond.The material strength and the chemical afﬁnity have major inﬂuence on tool wear.Jia and Fischer(1996)conducted a series of scratch tests of tungsten carbide with cobalt binder by means of a modiﬁed Vickers hardness tester,where signiﬁcant advantage of small-sized grain in abrasion resistance was clariﬁed.Paul et al.(1996)reported signiﬁcance of chemical aspect of tool wear in cutting with SCD tools.Saito et al.(2006)studied the inﬂuences of cobalt content and grain size on the wear resistance of tungsten carbide against carbon steel in their abrasion experiments,where the wear rate increased with cobalt content and grain size of tungsten carbide.Krakhmalev et al.(2007)also studied abrasion wear process of tungsten car-bide against silicon carbide abrasive.Ren et al.(2009)investigated inﬂuence of grain size and cobalt binder on grinding process.Zhang et al.(2012)also addressed experimental investigation to evaluate the inﬂuence of material composition on the cutting performance with SCD tools.Nevertheless,few researchers have investigated the inﬂuence of material composition on ultra-precision machining of sintered tungsten carbide so far.Further study on tungsten carbide machining considering material technology may lead to signiﬁcant machining performance increase.In order to investigate the possibility to extend tool life in the elliptical vibration cutting of tungsten carbide,comprehensive study on machinability of tungsten carbide is carried out in this paper.A series of fundamental cutting tests are conducted and the inﬂuence of material properties,cutting and vibration condi-tions and crystal orientation of single crystal diamond tools are investigated.Through analysis of experimental results,the inﬂu-ence of the binder material composition and the grain size of tungsten carbide on the machining performance of the ellipti-cal vibration cutting with SCD tools are studied.Based on these fundamentalﬁndings,feasibility of ultra-precision machining of tungsten carbide with micro/nano-scale structures,i.e.,textured grooves and a dimple pattern,are explored.Henceforth,the paper is organized as follows.The elliptical vibration cutting process is explained in Section2,followed by experimental conditions in Section3,and results of fundamental grooving and planing experiments in Section4.Finally,nano-sculpturing applications are presented in the following section.The paper is concluded with a summary.2.Elliptical vibration cutting processFig.1shows a schematic illustration of the elliptical vibration cutting process.The diamond tool is fed at a nominal cutting speed, and the tool tip is generally controlled to vibrate elliptically in the plane determined by the nominal cutting direction and the depth of cut direction.In the present study,the nominal cutting speed is set to be lower than the maximum vibration speed ensuring that the tool is separated from the workpiece in each vibration cycle.As shown in Fig.1,in a cycle of the elliptical vibration,the cutting starts from point A,and then the workpiece material is removed in the form of a chip.After the tangent of the tool trajectory becomes parallel to the rake face,the cutting tool separates from the chip at point B.Because of this intermittent process,reduction in the chip thickness and cutting forces can be attained.Due to this separation in each vibration cycle,the cutting tool and the work-piece can be cooled by the surrounding air and/or the cuttingﬂuid. This also allows suppression of adhesion between the tool and the workpiece.As a result,the thermo-chemical wear is supressed efﬁ-ciently.Because of these characteristics,ultra-precision machining of hardened steel can be attained,as reported in Brinksmeier and Gläbe(2001).Suzuki et al.(2007)also clariﬁed that ultra-precision machining of tungsten alloy becomes feasible due to the same reason.Kim and Loh(2007)clariﬁed that this process is also advan-tageous to fabricate micro structures due to small cutting force and less burr formation.Fig.2illustrates the elliptical vibrator and its control system for the elliptical vibration cutting.It was designed as a two-degree-of-freedom(2-DOF)elliptical vibrator and was developed by the authors.The vibrator can be actuated by exciting PZT actuators that are sandwiched with metal cylindrical parts.Since the vibrator is designed to have the same resonant frequencies in thesecond Fig.1.Elliptical vibration cutting process.2646J.Zhang et al./Journal of Materials Processing Technology 214(2014)2644–2659Table 1Types of tungsten carbide materials used in cutting experiments.NO.Average grain size (␮m)Binder phaseHardness (GPa)Elastic modulus (GPa)BL10.3Binderless,Co(≤0.2wt%)25.48675BL20.5Binderless,Co(≤0.2wt%)23.52680BL3 1.3–1.5Binderless,Co(≤0.2wt%)19.60650BL40.3Binderless,Co(≤0.1wt%)25.98680Co10.5Co(≤10wt%)19.60560Co2 1.3–1.5Co(≤10wt%)13.72560Co30.5Co(12wt%)17.30580Ni10.5Ni(≤10wt%)16.66510resonant mode of longitudinal vibration and the ﬁfth resonant mode of bending vibration,it can generate large longitudinal and bending vibrations simultaneously at the same ultrasonic frequency by exciting the actuators.As a result,a 2-DOF elliptical vibration can conveniently be obtained at the diamond tool tip.Vibration amplitudes can be adjusted arbitrary within 4␮m p-p by controlling the ampliﬁer gains as shown in Fig.2.3.Experimental conditions to study on machinability of tungsten carbide3.1.Workpieces and diamond toolsThis section introduces the workpieces and diamond tools uti-lized in various cutting experiments to investigate the cutting performance of tungsten carbide.Eight kinds of workpieces with different binder materials and grain size are prepared for exper-imental investigations.The material properties including catalog values of hardness and elastic modulus are listed in Table 1.Before the machining experiments,all workpieces are ground to make ﬂat surfaces.Note that the subsurface damage has signiﬁcant inﬂuence on the machining performance of tungsten carbide.Therefore,lap-ping with ﬁne abrasives is followed to make a ﬂat mirror surface and to remove subsurface damage from the workpiece surfaces.The tool used in these experiments is a SCD tool with a nose radius of 1mm,a clearance angle of 10◦and a negative rake angle of −20◦.The crystal orientation of the ﬂank face is set to be (100),while that of the rake face is set to be (100)or (110).These com-binations are denoted as R (100)F (100)and R (110)F (100)in this paper,where ‘R ’and ‘F ’represent the rake face and the ﬂank face,respectively.Fig.2.2-DOF elliptical vibration tool.3.2.Experimental setup and cutting conditionsThis section presents the experimental setup used in grooving and planing.All experiments are performed on an ultra-precision machine tool,whose positioning resolution is 1nm.The 2-DOF elliptical vibrator,which can generate arbitrary elliptical vibration at a frequency of about 36.2kHz,was attached to the X axis table.Fig.3shows the experimental setup.In order to investigate the inﬂuence of the depth of cut on the machined surface quality,the cutting feed is controlled by the synchronized motion of the X axis table and the Z axis table.The depth of cut was linearly increased in grooving and planing,as illustrated in Fig.3.Experimental con-ditions are summarized in Table 2.4.Grooving and planing experimentsparison of elliptical vibration cutting with ordinary cuttingAt ﬁrst,investigations are undertaken to compare elliptical vibration cutting performance with ordinary cutting.The binder-less workpiece of BL4is grooved by the ordinary cutting and the elliptical vibration cutting.Fig.4shows the scanning elec-tron microscope (SEM)images of the grooved surface on BL4at a depth of cut of 0.2␮m.In these experiments,the nominal cut-ting speed is set to 150mm/min.Amplitudes of elliptical vibration in the nominal cutting and depth of cut directions A c and A d are set to 4␮m p-p and 2␮m p-p to realize an elliptical vibration locus.As noted from Fig.4,the groove formed by the ordinary cutting is ﬁlled with numerous brittle defects.In contrast,a smooth sur-face can be obtained by the elliptical vibration cutting.As no brittle crack and asperity can be observed on the surface in the elliptical vibration cutting,ductile mode machining was attained success-fully.From this fact,it can be expected that the inside of tungsten carbide grains existing at the topmost layer of the remained surface was cut without fracture generation on the surface or pull-out of the grains,which are observed in the ordinary cutting.Next,Fig.5shows the cutting edges after grooving of the binder-containing workpiece of Co1.Considerable adhesion of the workpiece material can be observed on the rake face of the tool used in ordinary cutting,which may result in adhesion wear and/or considerable thermo-chemical reaction.The same phenomena was observed in the ordinary cutting of other binder-containingTable 2Experimental conditions for grooving and planing.Elliptical vibration conditionsFrequency [kHz]:36.2Amplitude in nominal cutting direction [␮m p-p ]:2–4Amplitude in depth of cut direction [␮m p-p ]:1–4Phase shift [◦]:90Cutting conditionsDepth of cut [␮m]:0–maximum 2Cutting speed [mm/min]:137.5–1100Pick feed for planing [␮m]:5Cutting ﬂuid:oil moistening (Bluebe LB-10)J.Zhang et al./Journal of Materials Processing Technology 214(2014)2644–26592647Fig.3.Illustration and picture of experimentalsetup.Fig.4.SEM images of grooved surface (workpiece:BL4,depth of cut:0.2␮m,nominal cutting speed:150mm/min).materials.On the other hand,no adhesion was observed in the elliptical vibration cutting.This fact indicates that the ellipti-cal vibration cutting may be effective to suppress tool wear progress and to attain better surface quality in machining of binder-containing tungsten carbide as well as steel materials.Mechanism of the ductile mode machining shown in Fig.4is considered as follows.In elliptical vibration cutting,the toolcutsFig.5.Cutting edges after grooving (workpiece:Co1).the surface that is ﬁnished in the previous vibration cycle.Thus,the actual uncut chip,i.e.,instantaneous uncut chip thickness shown in Fig.1,becomes extremely thin.Note that this uncut chip thickness becomes generally smaller as compared with the nominal depth of cut.The instantaneous uncut chip thickness in each vibration cycle becomes signiﬁcantly small especially when the tool cuts the ﬁnished surface around the bottom of the elliptical vibration.Because of this process,the actual depth of cut becomes smaller than the critical value for ductile machining due to the size effect in fracture toughness,resulting in signiﬁcant improvement of nominal critical depth of cut for ductile machining of tungsten carbide.The process is similar to that in milling,and Arif et al.(2012)clariﬁed similar improvement in milling process through experiments with the PCD tool.4.2.Inﬂuence of cutting parameters on surface qualityIn this section,the inﬂuence of several cutting parameters,i.e.,vibration amplitudes,depth of cut,and nominal cutting speed,on the surface quality is investigated in an empirical manner.Firstly,fundamental micro grooving experiments were carried out under several conditions.Fig.6demonstrates the surface quality of micro grooves machined on Co1where the nominal cutting speed and vibration amplitudes in the nominal cutting and depth of cut direc-tions,A c and A d ,are changed.The speed ratio,i.e.,the ratio of the maximum vibration speeds in the nominal cutting direction to the nominal cutting speed,is kept to be a constant value of 25.The grooved surfaces at the vibration amplitudes A c –A d of 4–4␮m p-p and 2–2␮m p-p are ﬁlled with micrometer-scale brittle defects,as shown in Fig.6.The defect size is several times larger than the single grain size of 0.5␮m.Thus,these defects are con-sidered to be due to the pull-out of agglomerated tungsten carbide2648J.Zhang et al./Journal of Materials Processing Technology 214(2014)2644–2659Fig.6.Inﬂuence of vibration amplitude on surface quality (workpiece:Co1,depth of cut:0.9␮m,amplitudes in nominal cutting and depth of cut directions:A c –A d ␮m p-p ,nominal cutting speed:v c mm/min).grains from the workpiece surface.On the other hand,similar large defects do not generate at vibration amplitudes of 4–2and 2–1␮m p-p .Similar experimental results were also observed in case of other binder-containing and binderless materials and hence it can be concluded that the inﬂuence of vibration amplitudes on ductile machining is not negligible.The inﬂuence of the depth of cut on the surface quality was also investigated.Fig.7demonstrates a groove surface of BL4,which was machined with a circular vibration (2␮m p-p )at a nominal cutting speed of 150mm/min.The depth of cut is gradually increased from 0␮m to 2␮m.Surface quality changes depending on the depth of cut,where brittle cracks can generate at a large depth of cut even in the elliptical vibration cutting.Transition border from ductile to brittle modes are observed at the depth of cut of about 1.5␮m.Agglomerated grains seem to be pulled out at one time from the surface,and this feature of the defects is the same as that shown in Fig.6.This kind of defect characterized by their size is deﬁnedas “multi-grain-size defect”in this paper.Note that similar surface deterioration with large defects is not observed in ordinary cut-ting.Hence,this is considered to be a speciﬁc problem in elliptical vibration cutting.These amplitude and depth of cut dependencies are considered to be related to the chip pulling-up-motion in the elliptical vibra-tion cutting.Fig.8shows schematic illustrations of the elliptical vibration cutting process.When the vibration amplitude is larger in the depth of cut direction,chip pulling-up-distance in this direction becomes longer.In addition,the chip pulling-up-distance increases up to about half the amplitude when the depth of cut is large.Sintered materials are not tough against tensile stress.Because of this nature,massive grains may be pulled out from the workpiece surface by the pulling-up-motion especially when upward motion distance in the depth of cut direction is longer than the grain size.When the ratio of amplitude in the depth of cut direction to that in nominal cutting direction is large,the slope of the cutting edge trajectory becomes steep while pulling up the chip.This steep tra-jectory is also considered to enhance the above-mentioned pull-out phenomena.Hence,the vibration amplitudes and the depth of cut need to be selected properly to avoid the “multi-grain-size defect”occurrence due to the pull-out of massive grains.The inﬂuence of the nominal cutting speed on the surface quality is also examined by conducting several grooving experiments.SEM images of the machined surfaces of BL1at a depth of cut of 0.5␮m are shown in Fig.9.It is conﬁrmed that higher quality surfaces in the ductile mode can be attained at lower nominal cutting speed.On the contrary,poor surfaces with a number of defects were observed distinctively at higher nominal cutting speed.The defect size is less than several hundred nanometers,which is almost identical to the grain size.Experiments performed on other workpieces indicated a similar tendency.To differentiate from “multi-grain-size defect”,this kind of defect is deﬁned as “single-grain-size defect”in the present research.This cutting-speed dependency of surface quality is considered to be associated with the cut volume in each vibra-tion cycle.It should be noted that the instantaneous uncut chip thickness is almost proportional to the nominal cutting speed.Thus,the cutting forces decrease and the strain energy at the deformed zone is reduced when the nominal cutting speed decreases.Small force and strain energy are beneﬁcial to suppress crack propaga-tions while machining.Hence,the selection of the cutting speed condition is signiﬁcantly important to suppress “single-grain-size defect”occurrence.Fig.7.Machined groove with the increasing of depth of cut (workpiece:BL4,amplitudes:2–2␮m p-p ,nominal cutting speed:150mm/min).J.Zhang et al./Journal of Materials Processing Technology 214(2014)2644–26592649Fig.8.Pull up motion with different vibrationamplitudes.Fig.9.Effect of nominal cutting speed on surface quality (workpiece:BL1,amplitudes:4–2␮m p-p ,depth of cut:0.5␮m).Fig.10.SEM micrographs of machined groove surface (depth of cut:0.9␮m,vibration amplitudes:2–1␮m p-p ,nominal cutting speed:137.5mm/min).4.3.Inﬂuence of binder material and grain size on cutting performancesGrooving experiments are also conducted on tungsten carbide with different binder content and grain sizes,such as BL1,Co1,BL2,BL3and Co2.SEM images of grooved surfaces of BL1and Co1are shown in Fig.10.As noted,brittle cracks are not observed from themachined surfaces.This also indicates that ductile mode machin-ing is realized at a large depth of cut of 0.9␮m.However,ductile machining was not realized by the same cutting conditions in BL2,BL3and Co2even when the depth of cut is smaller.This can be validated from Fig.11.Their surfaces are ﬁlled with the single-grain-size defects due to brittle fracture,which were observed in the high-cutting-speed machiningexperiment.Fig.11.Brittle fracture of machined groove surface (depth of cut:0.2␮m,vibration amplitudes:2–1␮m p-p ,nominal cutting speed:137.5mm/min).2650J.Zhang et al./Journal of Materials Processing Technology214(2014)2644–2659Comparing the grooving results of BL1,BL2and BL3,the dif-ference in surface integrity indicates that smaller grain size is advantageous to attain ductile mode machining.It is known that sintered materials consisting of smaller particles generally have better toughness due to smaller initial defect size inside the mate-rial,as reported by Fang and Eason(1995).Because of this nature,ﬁner grain is advantageous not only to increase the toughness of the material but also to realize ductile mode paring the grooving results of Co1and BL2,it is apparent that the binder phase is also advantageous to suppress the generation of brittle fracture.The defect size is,therefore,smaller in Co2than that in BL3,where the grain sizes are the same.The same advantage in fracture suppression was conﬁrmed in Ni1.4.4.Analysis of fundamental grooving experimentsThrough the grooving experiments,we found that single-grain-size defects can be generated much more easily as compared to multi-grain-size defects.Therefore,it is important to select appropriate process conditions focusing upon suppression of the single-grain-size defect generation.In order to evaluate the rel-ative difference in surface deterioration due to single-grain-size defects,the machined surface quality was classiﬁed into nine lev-els and a scale from0to8are provided by the authors based on optical microscope observation.0represents the best surface with minimal defects and8is associated with the worst surfaceﬁnish. Yan et al.(2009)developed a similar method to evaluate surface integrity of silicon carbide machined by SCD tools.Unlike the SEM observation,single-grain-size defects are simply observed as asperities or hazes by means of an optical microscope due to insufﬁcient resolution.However,it is considered to be avail-able to evaluate an extent of single-grain-size defects from the observed optical images.In the present study,machined surfaces are observed by an optical microscope.Then,optical micrographs of the machined surfaces with a size of250×250pixels were processed using the data processing software,MATLAB.One pixel size is0.18␮m×0.18␮m.As the defect area becomes darker than the smooth area without defects,the darker portion is identi-ﬁed as the defect surface.By counting the total number of pixels identiﬁed as a defect,the scores of the machined surfaces are eval-uated.For instance,high quality surfaces of BL1and Co1shown in Fig.10are indexed as0and1where no single-grain-size defect is observed.As compared with Co1,the score of the machined surface of BL1is judged as0because of the smoother surface.Scores of the machined surfaces of BL2,BL3and Co2in Fig.11are evaluated as 5,8,and6due to the single-grain-size defect.This quantiﬁcation process might be inﬂuenced by the threshold in data processing, but relative difference in the evaluation results seem to be mostly reliable.As mentioned above,surface deterioration due to single-grain-size defects may depend on the instantaneous uncut chip thickness in elliptical vibration cutting process.In particular,the maximum instantaneous uncut chip thickness while cutting theﬁnished surface is considered to be directly associated with surface dete-rioration.Fig.12illustrates the tool trajectory around the bottom and the theoretical maximum instantaneous uncut chipthickness Fig.12.Maximum instantaneous uncut chip thickness while cuttingﬁnished sur-face.Fig.13.Inﬂuence of maximum instantaneous uncut chip thickness on surface qual-ity(evaluated at a depth of cut of about1␮m).at the i-th cycle.By considering the kinematic model of ellipti-cal vibration cutting,Table3summarizes the calculated values of the maximum instantaneous uncut chip thickness in the grooving experiments.Fig.13indicates relations of surface quality score and maxi-mum instantaneous uncut chip thickness for all evaluated materials in grooving.The values of surface quality index increase with an increase of maximum instantaneous uncut chip thickness regard-less of the workpiece material.Hence,the maximum instantaneous uncut chip thickness needs to be decreased to achieve better sur-face quality.High quality surfaces in ductile mode,whose score is0or1,are obtained when the maximum instantaneous uncut chip thickness is less than or equal to4nm and the workpieces are BL1,BL4,Co1,Co3,and Ni1.In other words,ductile machin-ing cannot be attained for Co2,BL2and BL3under all evaluated conditions.These facts indicate that appropriate vibration ampli-tude and cutting speed conditions need to be selected to satisfy a small maximum instantaneous uncut chip thickness,which is less than or equal to4nm.The grain size also needs to be less than or equal to0.5␮m and binder material is helpful to attain ductile mode machining.The feature of multi-grain-size defect occurrence is almost the same as that of the single-grain-size defect occurrence.Table3Values of maximum instantaneous uncut chip thickness in grooving experiments[nm].Vibration amplitudes in nominal cutting/depth of cut directions␮m p-p4/44/24/12/22/1Nominal cutting speed [mm/min]137.5210.542 275842168 550321686231 11001246231––。

Analyzing the Citizens United v

Analyzing the Citizens United v Federal Election Commission CaseIntroduction:The Citizens United v. Federal Election Commission (2010) case is a landmark decision by the United States Supreme Court that significantly impacted campaign finance laws in the country. This case centered around the rights of corporations to make independent expenditures in political campaigns and whether these expenditures should be considered protected speech under the First Amendment. This article aims to provide an in-depth analysis of the Citizens United case, discussing its background, arguments made by both sides, the Supreme Court's decision, and its implications.Background:In 2002, Congress passed the Bipartisan Campaign Reform Act (BCRA) with the goal of regulating campaign financing. Among its provisions, BCRA prohibited corporations and labor unions from using their general treasury funds to finance "electioneering communications" within 30 days of a primary election or 60 days of a general election. Citizens United, a conservative nonprofit organization, produced a film critical of Hillary Clinton and wanted to broadcast it during the 2008 Democratic primary.Arguments:Citizens United argued that BCRA's prohibition violated their First Amendment rights to free speech. They contended that corporations should be allowed to spend money on expressing their political opinions, just as individual citizens and media corporations have this right. They further argued that the film was not an "electioneering communication" as defined under BCRA, but rather a form of protected speech.On the other hand, the Federal Election Commission (FEC) argued that corporations should not be afforded the same rights as individuals when it comes to political speech. They believed that corporate spending leads to the corruption of the political process andgives unfair advantages to certain candidates. The FEC contended that the government had a compelling interest in regulating corporate campaign expenditures to ensure the integrity of elections and the democratic process.Supreme Court's Decision:In a 5-4 decision, the Supreme Court ruled in favor of Citizens United, holding that corporate funding of independent political broadcasts in candidate elections cannot be limited. The Court reasoned that the restrictions on corporate spending in BCRA's electioneering communication provisions violated the First Amendment's protection of free speech. The majority opinion, written by Justice Anthony Kennedy, argued that political speech does not lose its First Amendment protection simply because it is funded by corporations.Implications:The Citizens United ruling had far-reaching implications for campaign financing in the United States. It led to the rise of Super PACs (Political Action Committees), which could collect unlimited funds from corporations, unions, and individuals, and spend them independently to support or oppose political candidates. Critics of the decision argue that it has further increased the influence of money in politics, allowing wealthy individuals and corporations to have an undue impact on election outcomes.The decision also raised concerns about the potential for foreign interference in American elections. With unlimited corporate spending on political campaigns, there is a risk that foreign entities could funnel money through U.S. corporations to influence election results. However, it is important to note that foreign contributions to U.S. elections are illegal under existing laws such as the Federal Election Campaign Act (FECA) and the Foreign Agents Registration Act (FARA).Conclusion:The Citizens United v. Federal Election Commission case resulted in a significant change in the landscape of campaign finance in the United States. The Supreme Court's decision to allow unlimited corporate spending in elections as protected speech under theFirst Amendment has sparked ongoing debates about the influence of money in politics and the integrity of the democratic process. Further reforms and regulations may be necessary to address the concerns raised by this decision and ensure a fair and transparent electoral system.。

certificate of analysis sizing calculations

Certificate of Analysis: Sizing Calculations IntroductionIn the field of analytical chemistry, a Certificate of Analysis (CoA) is a document that provides detailed information about the composition, quality, and characteristics of a given sample. Sizing calculations, a crucial part of CoA, involve determining the size parameters of particles or molecules present in a sample. This document aims to explain the importance of sizing calculations in a CoA and provide an overview of the methodology involved.Importance of Sizing CalculationsSizing calculations play a significant role in assessing the suitability and quality of a sample. By determining the size distribution of particles or molecules, scientists can infer important characteristics such as surface area, porosity, and reactivity. These parameters are essential for various industries, including pharmaceuticals, materials science, environmental analysis, and more. Sizing calculations also help in evaluating the efficiency or performance of processes like filtration, separation, and dispersion.MethodologyThe methodology for sizing calculations can vary depending on the nature of the sample and the desired size parameters. Here are some common techniques used for sizing calculations:1.Microscopy: Microscopy techniques, including optical microscopy,electron microscopy, and atomic force microscopy (AFM), are commonlyemployed for visualizing and measuring particles or molecules. By capturing images or scanning the sample, scientists can measure dimensions and obtain size distribution information.2.Spectroscopy: Spectroscopic techniques, such as dynamic lightscattering (DLS) or laser diffraction, exploit the behavior of light interactingwith particles to determine their size. DLS measures the intensity fluctuations of scattered light, while laser diffraction analyzes the diffraction patternproduced by particles. These techniques are non-destructive and can provide a rapid assessment of size distributions.3.Particle Counter: A particle counter, often used in cleanroomenvironments or environmental analysis, counts and sizes particles based on their electrical or optical properties. By measuring the changes in electricalconductivity or light scattering, particle counters can estimate the particle size distribution.4.Sedimentation: Sedimentation techniques involve allowing particlesto settle under the influence of gravity. By measuring the settling velocity oranalysing the sedimentation curve, scientists can calculate the size distribution using principles like Stokes’ Law. Sedimentation methods are particularlyuseful for studying larger particles or particles with irregular shapes.Reporting the ResultsOnce the sizing calculations are performed, the results need to be accurately reported in the CoA. The CoA should include the following information:1.Size Distribution: The CoA should clearly present the sizedistribution of particles or molecules in the sample. This can be represented asa histogram, cumulative distribution curve, or statistical parameters like mean,median, mode, and standard deviation.2.Methodology: The CoA should mention the methodology used forsizing calculations. This helps in validating the results and ensuringreproducibility.3.Instrumentation: If specific instrumentation or equipment was usedfor the sizing calculations, it should be mentioned in the CoA. This includesdetails such as the microscope model, spectrometer specifications, particlecounter type, etc.4.Uncertainty: It is crucial to address the uncertainty associated withsizing calculations. This can be achieved by reporting the confidence interval, measurement error, or acknowledging potential sources of variability.ConclusionSizing calculations are a fundamental part of a Certificate of Analysis, providing vital information about the size distribution of particles or molecules in a sample. By employing various techniques such as microscopy, spectroscopy, particle counting, and sedimentation, scientists can accurately determine the size parameters. The reported results should include the size distribution, methodology, instrumentation, and any associated uncertainty. These measurements aid in assessing the sample’s quality and suitability for different applications across multiple industries.。

中西方饮食文化(英文)

Table Manners
03
It is considered point to use the chokes correctly, not to point at others with the chokes, and to clean up any spills or crumbs on the table
Conclusion
CATALOGUE
05
The differences between Chinese and Western food culture reflect their corresponding cultural values and worldviews Chinese culture emphasizes collectivism and respect for nature, while Western culture emphasizes individualism and innovation
Introduction
CATALOGUE
01
The sum of the knowledge, skills, practices, and beliefs surrounding the production, preparation, and consumption of food in China It encompassed the entire process of food from cultivation to table, including cooking methods, table men, and the role of food in society
Chinese Cooking Techniques

蒙古黄芪种子处理方式的响应面优化

«s^蒙古黄芪种子处理方式的响应面优化刘杰t,张雄杰2,霍秉新3,尹春2,刘燕3,贾长松3,盛晋华1（1.内蒙古农业大学农学院，呼和浩特010019;2.内蒙古天际绿洲特色生物资源研发中心，呼和浩特010018;3.内蒙古天衡制药有限公司，内蒙古巴彦淖尔014400）摘要优化蒙古黄芪种子的处理方式，进而提高其发芽率。

选用磨砂+温水浸种的组合处理，将蒙古黄芪种子的发芽率作为评价指标，以磨砂时间、浸种温度、浸种时间为考察因素，采用单因素试验与响应面分析相结合的方法，优化其处理方式。

结果表明，磨砂时间以15min发芽率最高，达到72%，确定适宜的磨砂时间是10~20min；浸种温度为60°C时发芽率最高，达到76%，确定适宜的浸种温度是50〜70°C;浸种时间以10min发芽率最高，达到77%，确定适宜的浸种时间5〜15min。

各因素对蒙古黄芪种子发芽率影响的大小为：浸种温度〉磨砂时间〉浸种时间。

磨砂时间13min.浸种温度56C、浸种时间8min为蒙古黄芪种子最佳的处理方式，在此处理方式下蒙古黄芪种子的发芽率达90.7%，与预测值92%相近，所优化的处理方式合理、可行，可为生产实践提供参考。

关键词：蒙古黄芪；发芽率；响应面分析法DOI：10.16590/.cnki.1001-4705.2021.03.023中图分类号：S567.23+9文献标志码：A文章编号：1001-4705（2021）03-0023-06Response Surface Optimization of Seed Treatment of Astragalus mongholicusLIU Jie1,ZHANG Xiongjie2,HUO Bingxin3,YIN Chun2,LIU Yan3,JIA Changsong3,SHENG Jinhua1(1.Agricultural College,Inner Mongolia Agricultural University,Hohhot.,Inner Mongolia010019,China；2Jnner Mongolia Horizon Oasis Research Center of CharacteristicBiologic Resource,Hohhot.Inner,Mongolia010018,China；3Jnner Mongolia Tian Heng Pharmaceutical Co.td014400,China)Abstract:In order to optimize seed treatment of Astragalus mongholicus and improve germinationrate,the combined treatment of grinding with sand and soaking seeds with warm water was selectedand the germination rate of A.mongholicus seeds were taken as the evaluation index.The grindingtime,soaking temperature and soaking time were considered as the indexes,and the single factor testand response surface analysis were used to optimize the treatment.The method of single factor testcombined with response surface analysis was used to optimize the treatment.The results showed thatthe highest germination rate was72%when the seeds were grinded for15min,and the optimumgrinding time was10—20min.Meanwhile,the highest germination rate reached76%when the seedswere soaked with60°C water,and the optimum temperature for seed soaking was50—70°C.In add—tion,thehighestgerminationratewas77%whentheseedsweresoakedfor10min,andtheoptimumsoakingtimewas5—15min.Tosumup,theinfluenceofvariousfactorsonthegerminationrateof A.mongholicus seeds was as follows soaking temperature〉1grinding time〉soaking time.The optimal收稿日期2020-09-30基金项目现代农业产业技术体系建设专项（CARS-21）：2018年度中央引导地方科技发展专项资金“太仆寺旗蒙古黄芪良种繁育与标准化生态种植技术的应用研究”内蒙古重大专项“黄河流域西北地区植物种质大数据平台及仿野生蒙中药材种子基因识别及育种、育苗培育”呼和浩特市应用技术项目道地蒙中药材种子优选繁育和标准化种植技术研究（2020-社-4）作者简介：刘杰（1991—）男（汉族）山东青岛人；在读博士，主要从事药用植物栽培生理及繁育的研究（E-mail：****************）.通讯作者盛晋华（1968—）女（汉族）山东莱州人；教授，博士生导师，主要从事药用植物栽培生理及繁育的研究。

无心磨削过程碳排放量及其关键影响因素解析

图3 基于装配偏差度的主锥再制造装配质量优化图λ1(1)=ωs ∑n i =1ωt α(i)s+ωe ∑ni =1ωbβ(i)e =0.399同理可求其他各级修复装配偏差度并进行质量优化㊂应用MA T L A B 7.0进行装配偏差度的模拟仿真,如图4所示㊂由图4可看出,模拟退火遗传算法有较强的局部搜索能力,通过多约束㊁多目标下局部优化,可达到全局装配偏差有效减小的目的㊂利用模拟退火遗传算法的爬山”特性,可提高运算的收敛速度,实现再制造装配生产过程的装配偏差在线优化㊂图4 M A T L A B 模拟仿真再制造装配属于小批量的离散作业,一次作业个体数较小,为模拟最佳装配环境,采用的遗传种群规模为19,最大迭代次数为100,pc =0.85,p m =0.01㊂采用模拟退火遗传算法搜索,获得了最终种群中最大适应度为0.13,优化求解,当某一个零部件装配完,则进入下一个循环搜索,进行剩余再制造零部件装配偏差优化㊂综上所述,基于装配偏差度的复杂机械产品再制造质量在线优化方法有效可行,能很好地对再制造装配偏差进行有效优化㊂5 结论(1)描述了复杂机械产品再制造过程装配偏差,构造了复杂机械产品再制造装配偏差度函数,描述了基于装配偏差度的再制造质量优化判断条件及方法,对再制造过程质量控制域进行相关划分描述,揭示再制造过程装配偏差因素与质量变迁之间的关联,为再制造质量优化描述方法的研究提供了支持㊂(2)对基于装配偏差度的复杂机械产品再制造质量优化模型进行了实例分析,对质量进行相关优化,为再制造过程质量控制提供了有效的基础㊂参考文献:[1] 徐滨士.基于先进表面工程技术的汽车发动机再制造工程及其产业模式[J ].数字制造科学,2008,6(2):19‐34.X uB i n s h i .B a s e do nA d v a n c e dS u r f a c eE n g i n e e r i n gT e c h n o l o g y E n g i n e e r i n g a n d A u t o m o b i l e E n g i n e R e m a n u f a c t u r i n g I n d u s t r y M o d e l [J ].D i g i t a lm a n u -f a c t u r i ng s c i e n c e ,2008,6(2):19‐34.[2] 徐滨士.再制造工程基础及其应用[M ].哈尔滨:哈尔滨工业大学出版社,2005.[3] 张国庆,荆学东,浦耿强,等.汽车发动机可再制造性评价[J ].中国机械工程,2005,16(8):739‐742.Z h a n g G u o q i n g ,J i n g X u e d o n g ,P u G e n g q i a n g ,e t a l .A s s e s s m e n t o n R e m a n u f a c t u r a b i l i t y o ft h e A u t o m o b i l eE n g i n e s [J ].C h i n a M e c h a n i c a lE n g i -n e e r i n g.,2005,16(8):739‐742.[4] 钟骏杰,范世东,姚玉南,等.再制造性综合评估研究[J ].中国机械工程,2003,14(24):2110‐2113.Z h o n g J u n j i e ,F a nS h i d o n g ,Y a oY u n a n ,e t a l .R e -s e a r c ho n S y n t h e t i c a l A s s e s s m e n tf o r R e m a n u f a c -t u r a b i l i t y [J ].C h i n aM e c h a n i c a l E n g i n e e r i n g ,2003,14(24):2110‐2113.[5] M u t h a A ,P o k h a r e lS .S t r a t e g i c N e t w o r k D e s i gn f o rR e v e r s e L o g i s t i c sa n d R e m a n u f a c t u r i n g U s i n g N e wa n d O l dP r o d u c t M o d u l e s [J ].C o m p u t e r s &I n d u s t r i a l E n g i n e e r i n g ,2009,56(1):334‐346.(下转第1497页)㊃7741㊃基于装配偏差度的复杂机械产品再制造质量优化方法刘明周孙志军葛茂根等Copyright ©博看网. All Rights Reserved.无心磨削过程碳排放量及其关键影响因素解析郭登月程凯丁辉闫纪红马云辉哈尔滨工业大学,哈尔滨,150001摘要:准确量化制造过程中的碳排放量是实现低碳制造的前提条件㊂磨削是一种广为应用的精密加工方法,同时也是切削热量高㊁使用切削液量大㊁加工环境差㊁能量利用效率低的加工工艺㊂利用公理化设计找出影响低碳磨削的各层关键影响因素,综合考虑了能源㊁资源和废弃物对碳排放量的影响,建立了数控粗磨㊁精磨和光磨整个磨削过程的E RW C 碳排放量定量分析模型㊂最后进行了实际磨削加工测量实验,并用MA T L A B 给出了模型计算比较结果,解析了关键影响因素㊂关键词:公理化设计;E RW C 模型;磨削;碳排放量;低碳制造中图分类号:T H 162 D O I :10.3969/j.i s s n .1004-132X.2014.11.011A n I n v e s t i g a t i o no n Q u a n t i t a t i v eA n a l y s i s o fC a r b o nF o o t pr i n t i n C e n t r e l e s sG r i n d i n g P r o c e s s a n d I t sK e y Fa c t o r s G u oD e n g y u e C h e n g K a i D i n g H u i Y a n J i h o n gM aY u n h u i H a r b i n I n s t i t u t e o fT e c h n o l o g y,H a r b i n ,150001A b s t r a c t :T o a c c u r a t e l yq u a n t i f y c a r b o nd i o x i d e e m i s s i o n i nm a n u f a c t u r i n gp r o c e s s i s a p r e r e q u i -s i t e f o r l o w ‐c a r b o nm a n u f a c t u r i n g .G r i n d i n g i s aw i d e l y u s e d a s p r e c i s i o nm a c h i n i n g m e t h o d ,h o w e v -e r ,i t i sa l s oa l e s se n e r g y ‐ef f i c i e n ta n de n v i r o n m e n tu n f r i e n d l yp r o c e s s i ng m e th o dc o n s u mi n g l a r g e a m o u n t o f c u t t i n g f l u i da n d g e n e r a t i n g h i g hc u t t i n g h e a t c o m p a r e dw i t ho t h e r s .T h e p a p e r i d e n t i f i e d k e y f a c t o r s i n f l u e n c i n g c a r b o nd i o x i d e e m i s s i o nd u r i n gg r i n d i n gp r o c e s su s i n g a x i o m a t i cd e s i g n m e t h -o d .C o n s i d e r i n g r e s o u r c eu t i l i z a t i o n ,e n e r g y c o n s u m p t i o na n dw a s t e g e n e r a t i o n i m p a c t i n g onc a r b o n d i o x i d ee m i s s i o n ,t h eE RW C (e n e r g y,r e s o u r c e ,w a s t e ,c a r b o n )c a r b o nd i o x i d ee m i s s i o n q u a n t i t a t i v e a n a l y s i sm o d e l o f t h e e n t i r e g r i n d i n gp r o c e s sw i t h r o u g h i n g ,f i n i s h i n g a n d s p a r k ‐o u t s t a g e sw a s d e v e l -o p e d .M e a r s u r e m e n t e x p e r i m e n t sw e r e d o n e t o c o l l e c t d a t a n e e d e d a n d c o m p u t a t i o n a l a n a l y s i s o nb o t h E RW C m o d e l a n d i t sk e y fa c t o r sw a s d o n ew i t h MA T L A B .K e y wo r d s :a x i o m a t i cd e s i g n ;E RW C m o d e l ;g r i n d i n g ;c a r b o nd i o x i d ee m i s s i o n ;l o w ‐c a r b o n m a n u f a c t u r i n g收稿日期:2013 01 170 引言据统计,目前我国制造业的碳排放量占我国碳排放总量的80%以上[1],而且机械制造行业主要产品单位耗能高出国际先进水平的30%[2]㊂2011年,我国机床保有量约800万台,仅考虑电能消耗对碳排放量的影响,这些机床运行一年的碳排放量相当于1.66亿辆S U V 汽车的碳排放量㊂因此,研究机床的能耗/碳排放对我国实现低碳经济”的发展模式具有重大意义㊂磨削是制造加工中应用最广泛的精密加工方法,磨床的比重反映了一个国家制造业的发展水平㊂但是,磨削的能耗比一般切削的能耗大,是能耗效率较低的加工方式,并且磨削温度高,需要大量磨削液进行冷却,而磨削液的处理对环境影响十分巨大,砂轮的定期修整也会导致电能与资源的损耗,因此磨削是高消耗资源㊁高耗能和高排放的加工方式㊂当前的低碳加工研究领域主要以车削和铣削为主,对磨削的低碳研究涉及甚少,因此研究数控磨削的能耗/碳排放具有重大意义㊂本文综合考虑能源(E )㊁资源(R )㊁废弃物(W )与碳排放量(C )之间的关系,利用公理化设计定性分析了实现低碳磨削的影响因素,建立了磨削过程基于E RW C 的碳排放量计算模型㊂1 基于公理化设计的低碳磨削建模影响磨削加工碳排放量的因素很多,各个因素之间的相互关系错综复杂,如图1所示㊂公理化设计提供了一种定性分析方法,有助于辨别影响低碳磨削的关键因素㊂根据低碳磨床的应用目的确定最高层次的功能需求,以及要完成此功能的设计参数㊂F R 0表示低碳磨削;D P 0表示低碳磨床㊂则第一层功能需求为[F R 0]=[X ][D P 0]D P 0的确定是F R 0进一步分解的基础㊂为了实现D P 0,进行之”字形分解㊂F R 1表示去除㊃8741㊃中国机械工程第25卷第11期2014年6月上半月Copyright ©博看网. All Rights Reserved.图1 磨削加工碳排放影响因素分析材料;F R 2表示尽可能减少碳排放㊂由第二层的功能需求确定第二层设计参数为:D P 1表示调试好的无心磨床;D P 2表示符合低碳加工标准㊂则第二层功能需求为F R 1éëêêùûúúF R 2=X 00éëêêùûúúX D P 1éëêêùûúúD P 2F R 21表示减少电能的消耗;F R 22表示减少资源的使用;F R 23表示降低废弃物的排放;D P 21表示电能节约系统;D P 22表示资源节约系统;D P 23表示废弃物回收系统㊂则第三层的功能需求为F R 21F R 22éëêêêùûúúúF R 23=X 00X X 0éëêêêùûúúúX X X D P 21D P 22éëêêêùûúúúD P 23第四层的功能需求和设计参数的设计如下㊂(1)对于F R 21和D P 21:F R 211表示缩短空载或轻载时间;F R 212表示选择功率合适的电机和泵;F R 213表示减少摩擦;F R 214表示轻量化设计;F R 215表示选择合适的磨削参数;D P 211表示高的磨削效率;D P 212表示合理的电机和泵;D P 213表示润滑轴承导轨等;D P 214表示轻质的转动及直线部件;D P 215表示优化的数控程序㊂则有F R 211F R 212F R 213éëêêêêêùûúúúúúF R 214=X 0000X 0000X 0000éëêêêêêùûúúúúúX D P 211D P 212DP 213éëêêêêêùûúúúúúD P 214(2)对于F R 22和D P 22:F R 221表示提高砂轮使用寿命;F R 222表示减少砂轮修整损耗;F R 223表示提高磨削液耐用度;F R 224表示提高润滑效率;D P 221表示耐磨砂轮;D P 222表示砂轮尺寸与工件磨削长度吻合;D P 223表示使用寿命长的磨削液;D P 224表示密封好的润滑系统㊂则有F R 221F R 222F R 223éëêêêêêùûúúúúúF R 224=X 0000X 0000X 0000éëêêêêêùûúúúúúX D P 221D P 222D P 223éëêêêêêùûúúúúúD P 224(3)对于F R 23和D P 23:F R 231表示改良过滤系统;F R 232表示回收工件磨屑;F R 233表示回收砂轮磨粒;D P 231表示磨削液磨屑砂粒分离系统;D P 232表示定期收集工件磨屑;D P 233表示定期收集砂粒㊂则有F R 231F R 232éëêêêùûúúúF R 233=X 00X X 0X 0éëêêêùûúúúX D P 231D P 232éëêêêùûúúúD P 233由现有的设计矩阵可以看出,各层矩阵都是对角或下三角矩阵,符合公理化设计可行性原理㊂对于第五层的设计,要探讨砂轮因素㊁磨削参数等对上一层的影响㊂2 数控磨削过程E RW C 模型的建立由公理化设计建模可知,要想完全说明影响磨削过程碳排放量的底层关键因素,必须进行量化计算分析㊂现有的国内外低碳制造理论,多是从能源㊁资源㊁废弃物中的一个维度或侧面来描述碳排放[3‐6]㊂为了全面系统地描述磨削过程碳排放量,本文从磨削过程能源(E )㊁资源(R )㊁废弃物㊃9741㊃无心磨削过程碳排放量及其关键影响因素解析郭登月程凯丁辉等Copyright ©博看网. All Rights Reserved.(W )3个方面进行分析㊂在能耗研究方面,多数研究涉及机床,但多集中在空载和加工两种机床工作状态,缺乏详尽的机床能耗分类分析[4,7‐8]㊂本文在此基础上,进行了磨削过程多元能耗研究㊂2.1 材料去除能量消耗由文献[9‐10],磨削时切向磨削力为F t =1000k b ω-2εd ε/2e (a p (t ))1-ε/2v 1-εW v ε-1S (1)d e =d S d W /(d S +d W )式中,ε为常数,根据不同磨削条件,取值0.2~0.5;k 为与工件材料㊁润滑条件等有关的系数,取值0.5;b 为磨削宽度,mm ;ω为有效磨粒间隔,取值0.68mm ;d S 为砂轮直径,mm ;d W 为工件直径,mm ;v S 为砂轮线速度,m /s;v W 为工件线速度,m /s ;a p (t )为砂轮每转磨削深度(随时间变化),mm ㊂实际磨削过程中,磨床刚度是影响每转磨削深度a p (t )㊁磨削力㊁磨削质量甚至碳排放量的重要因素,也是实时仿真计算磨削状况的关键,不可以忽略㊂考虑刚度,则对整个磨削系统有如下的微分方程[11]:τr ″(t )+ξr '(t )=u (2)ξ=1+d Wd SG式中,r 为进给量,mm ;τ㊁ξ为常数,在后面的仿真计算中τ取值0.8;G 为磨削比,取值50;u 为导轮架横向控制进给率,粗磨和精磨时u 是常数,光磨时u 为0㊂设t ∈[0,t 1)是粗磨阶段,t ∈[t 1,t 1+t 2)是精磨阶段,t ∈[t 1+t 2,t 1+t 2+t 3]是光磨阶段,磨削过程进给量随时间变化如图2所示㊂图2 磨床粗磨、精磨和光磨三阶段示意图在粗磨阶段,求解式(2),t 时刻的实际总进给量和实际每转磨削深度分别为r (t )=u 1ξ(t -τξ+τξe-ξt /τ)(3)a p (t )=r '(t )n W =u 1ξn W(1-e -ξt /τ)(4)式中,n W 为工件转速㊂精磨阶段总的进给量和实际每转磨削深度为r (t )=1ξ{u 2(t -t 1)+u 1t 1+τξ[-u 2+u 1e -ξt /τ+(u 2-u 1)e -ξ(t -t 1)/τ]}(5)a p (t )=1ξn W [u 2-u 1e -ξt /τ-(u 2-u 1)e -ξ(t -t 1)/τ](6)光磨阶段总的进给量和实际每转磨削深度为r (t )=u 2ξt 2+u 1ξt 1+τξ2[u 1-u 2e ξτ(t 1+t 2)+(u 2-u 1)e ξt 1/τ]e -ξt /τ(7)a p (t )=-1ξn W [u 1-u 2e ξ(t 1+t 2)/τ+(u 2-u 1)e ξt 1/τ]e -ξt /τ(8)得到3个阶段的每转磨削深度a p (t )后,代入切向磨削力公式,即可得到随时间变化的切向磨削力F t ㊂那么,磨床去除材料功率为P (t )=F t v S磨床材料去除能量消耗为E C =∫t 1+t 2+t 3P (t )d t (9)2.2 磨床基本能量消耗数控磨床对碳排放量的影响主要通过磨床上各个电机和泵以及电气柜等耗能部件对电能的消耗进而对碳排放量造成影响㊂磨床上电机等电能的消耗可由下式表示[12]:E m o t o r =E l e +E s +E f +E a(10)其中,E l e 是电机电损耗能,由于电机负载率越大,其运行效率越高,因此为了达到节能的效果,要缩短空载或轻载的时间㊂E s 是广义储能,包括电机内的磁场能和磨床内各传动部件的动能㊂因此,在设计机床时,减小转动部件的转动惯量和直线运动部件的质量,能减少电能的消耗㊂E f 是摩擦损耗能量,采用润滑效果更好的轴承等来提高润滑效果,也能减少电能的消耗㊂以上分析为公理化设计里F R 211‐D P 211㊁F R 213‐D P 213㊁F R 214‐D P 214提供了依据㊂E a 是辅助系统耗能,如电气柜㊁照明装置等耗能㊂磨床基本耗能可表示为磨床基本功率P b a s e和磨床运行时间的乘积㊂其中,磨床基本功率是指维持磨床正常工作所必须的电机㊁泵等所消耗的功率,主要包括磨削液泵㊁润滑液泵㊁电气柜㊁照明装置㊁X 轴伺服电机等㊂它们的功率几乎不随外界环境的变化而变化㊂这一基本功率P b a s e 可由实验测得,测量结果如图3所示㊂电能基本消耗可表示为E b a s e =E l e +E s +E f +E a =∫t 1+t 2+t 3P b a s ed t (11)2.3 磨床变频能量消耗数控磨床在工作过程中,除了基本耗能外,还有两个主要耗能电机:砂轮电机和导轮电机㊂由于这两个电机控制系统的变频作用使这两个电机的功率随各自主轴转速的变化而变化,因此需要㊃0841㊃中国机械工程第25卷第11期2014年6月上半月Copyright ©博看网. All Rights Reserved.图3 磨床空载时功率分布单独分析㊂由文献[13‐14]可得变频主轴功率与转速n 的关系为P i n =P u 0+k 1n +k 2n 2(12)式中,P u 0㊁k 1㊁k 2为常数㊂由式(12)可得砂轮主轴和导轮主轴功率分别为P S =P 0S +k 1S n S +k 2S n 2SP D =P 0D +k 1D n D +k 2D n 2}D因此,磨床变频耗能为E F C =∫t 1+t 2+t 3(P S +P D )dt (13)2.4 磨床响应能量消耗及总能耗对碳排放量的影响工件的被磨削会对磨床造成额外的能耗响应,其中主要的部分是工件对导轮的切向摩擦力引起的导轮电机额外负载以及砂轮轴和导轮轴轴承摩擦对各自电机的额外负载等㊂由于轴承直径较小并且无心磨削润滑效果较好,因此只考虑工件对导轮的切向摩擦力引起的导轮电机额外负载㊂在无心磨削过程中,工件共受到7个作用力:工件自身重力m g ㊁砂轮对工件的正压力F n 和滑动摩擦力F t ㊁托板对工件的正压力B n 和滑动摩擦力B t ㊁导轮对工件的正压力R n 和静摩擦力R t ,如图4所示㊂根据工件力平衡,有F n s i n α+R n s i n β+B nc o s θ= m g +F t c o s α-B t s i n θ-R t c o s βF n c o s α+R t s i n β+B ns i n θ= R n c o s β+Bt c o s θ-F t s i n üþýïïïïα(14)由式(14)可得导轮对工件的切向静摩擦力R t ㊂利用MA T L A B 可得F t ㊁F n ㊁R t ,如图5所示㊂由于工件磨削引起的磨床响应能耗E r e s po n s e 为E r e s po n s e =∫t 1+t 2+t 3R t v Dd t (15)式中,v D为导轮线速度,m /s ㊂考虑砂轮电机磨削效率为η,η一般为0.7~图4磨削过程工件受力图图5 F t ㊁F n ㊁R t 图0.85,因此磨床总耗能为E =E b a s e +E F C +E C /η+E r e s p o n s e (16)在整个磨削阶段,磨床消耗电能的碳排放量为C E =E C e3.6×106(17)式中,C e 为消耗电能对应的碳排放量,g /(k W ㊃h )㊂2.5 砂轮磨损对碳排放量的影响砂轮有个评价指标称为磨削比G ”,它是指砂轮单位体积磨损所对应的去除工件材料体积,通常在稳定磨削时,可表示为G =ΔV W ΔV S所以砂轮磨损量可表示为ΔV S =πΔr l d WG式中,Δr 为工件被磨削深度(随时间变化),mm ;l 为工件被磨削的长度,mm ㊂砂轮体积为V GW =πB 4(d 2S m a x -d 2m i n)式中,B 为砂轮宽度,mm ;d S m a x 为砂轮可用最大直径,mm ;d m i n 为砂轮最小处直径,mm ㊂在砂轮生命周期内,可供使用体积为V A =πB 4(d 2S m a x -d 2S m i n)式中,d S m i n 为砂轮可用最小直径,mm ㊂砂轮被修整掉的体积可表示为V d =N d B a d π(d S m a x +d S m i n )/2式中,N d 为砂轮可被修整次数;a d 为砂轮修整深度,mm ㊂砂轮修整一次的碳排放量可表示为㊃1841㊃无心磨削过程碳排放量及其关键影响因素解析郭登月程凯丁辉等Copyright ©博看网. All Rights Reserved.C GWD R =C e3.6×106P GWD R t GWD R =C e 3.6×103P GWDR B π(d S m a x +d S m i n )/2s d v S式中,s d 为砂轮修整导程,mm /r ;P GWD R 为砂轮修整时磨床功率,W ㊂砂轮磨损对碳排放量的影响可表示为C GW =ΔV S V A -V d[(C GW P +C GWD )ρGW V GW +N d C GWD R ](18)式中,C GW P 为生产砂轮对应的碳排放量,g /k g;C GWD 为处理废弃砂轮的碳排放量,g /k g ;ρGW 为砂轮密度,k g /m 3㊂2.6 磨削液消耗对碳排放量的影响在实际机床加工工件时,由于切削液会蒸发㊁粘在工件和切屑上被带走等原因,在切削液全部更换之间会有多次补充切削液的过程㊂但考虑到磨削是比较精密的过程,因此磨削液定期一次全部更换,不进行补充㊂磨削液消耗对碳排放的影响为C G F =t G F Ut G F R(C G F P +C G F D )Q G F I(19)式中,C G F 为磨削液消耗的碳排放量,g ;t G F U 为磨削液使用时间,s ;t G F R 为磨削液两次更换之间可使用的时间,s;C G F P 为生产磨削液所需的碳排放量,g /L ;C G F D 为处理1L 磨削液所需的碳排放量,g /L ;Q G F I 为磨削液初始量,L ㊂2.7 润滑液消耗对碳排放量的影响对于磨床系统来说,需要定期㊁不定期润滑的部位很多㊂等效到主轴部位,润滑液消耗对碳排放的影响为C L O =t L O Ut L O SC L O P Q L O S(20)式中,C L O 为润滑液消耗的碳排放量,g ;t L O U 为主轴转动时间,s ;t L O S 为润滑液两次添加之间主轴转动时间,s;C L O P 为生产润滑液所需的碳排放量,g/L ;Q L O S 为润滑液每次的添加量,L ㊂2.8 磨屑对碳排放量的影响切屑体积为ΔV W =πΔr l d W磨削过程切屑的产生对碳排放量的影响为C W C =ΔV W ρW C W CD (21)式中,C W C为切屑产生的碳排放量,g ;ρW 为切屑密度,k g /mm 3;C W C D 为处理切屑产生的碳排放,g /k g㊂由文献[15],上述各个影响因素的碳排放因子如表1所示㊂2.9 E R W C 计算模型由以上分析可得,在t ∈[0,t 1+t 2+t 3]内,数控磨削的碳排放量C G r i n d i n g 随磨削时间变化的计算模型如下:C G r i n d i n g (t )=C E (t )+C GW (t )+C G F (t )+C L O (t )+C W C (t )(22)表1 碳排放因子表因子名称数值C e (g /(k W ㊃h ))381C GW P (g /k g )33747.8C GWD (g /k g )13.46C G F P (g /L )977.6C G F D (g /L )2.9C L O P (g /L )469C W C D (g /k g)63.43 E RW C 碳排放量模型测量实验与关键影响因素解析3.1 E R W C 模型的M A T L A B 计算分析在E RW C 模型建立的过程中,需要进行测量实验获取所需的实验数据,测量仪器是F l u k e1735功率仪㊂实验选用20mm×150mm 圆柱形工件,材质是45钢㊂选用MK 1080型无心磨床进行磨削加工,磨削深度是0.2mm ㊂如图6所示㊂图6 磨削过程功率测量实验比较3种磨削方案,如表2所示㊂表2 磨削方案参数表u 1(mm )t 1(s )u 2(mm )t 2(s )方案一0.02570.012.5方案二0.02080.014方案三0.015100.00510 3种磨削方案的碳排放量C G r i n d i n g 随时间变化曲线如图7所示㊂图7 磨削过程碳排放曲线图㊃2841㊃中国机械工程第25卷第11期2014年6月上半月Copyright ©博看网. All Rights Reserved.比较图2和图7,碳排放量曲线和进给量曲线有很强的相关性,因此进给量是影响碳排放量的关键因素㊂尽管大的进给量会导致大的碳排放量,但是在磨削深度一定的情况下,大的进给量磨削时间短,最终的碳排放量小㊂图8所示为方案三各影响因素对应的碳排放量占总的碳排放量贡献比例㊂由图8可见,电能消耗和砂轮磨损与修整是影响碳排放的主要因素㊂图8 方案三各影响因素碳排放量所占比例3.2 E R W C 模型关键影响因素解析导轮转速和砂轮转速是磨削过程重要的磨削控制参数㊂导轮转速对材料去除能耗㊁响应能耗㊁变频能耗对应的碳排放量皆有影响,利用方案三的进给量和加工时间等数据,MA T L A B 计算结果如图9所示㊂(a)材料去除能耗(b)响应能耗 (c)基本能耗(d)变频能耗图9 导轮转速对4种能耗碳排放的影响曲线无心磨床是导轮带动工件旋转,两者线速度一致,因此工件转速n W 和导轮转速n D 成正比㊂因此,由式(4)㊁式(6)㊁式(8)可知,每转磨削深度a p (t )正比于n -1D,而工件线速度v W 正比于n D ;由式(1)可知,切向磨削力F t 正比于n -ε/2D,而ε是常数,约为0.2~0.5,材料去除能耗与切向磨削力F t 正相关,因此导轮转速越大,材料去除能耗越小㊂由图5可知,响应能耗中的R t 与切向磨削力F t 正相关,也即与n -ε/2D 正相关,而导轮线速度v D 正比于导轮转速n D ,也即磨床响应能耗E r e s po n s e 与n 1-ε/2D正相关,1-ε/2>0,因此导轮转速越大,磨床响应能耗越大㊂基本能耗与导轮转速无明显关系,不随n D 的变化而变化㊂变频能耗包含导轮轴和砂轮轴,其中导轮轴能耗和导轮转速成二次关系,已在2.3节作了说明,并且在n D 的实际范围内,转速越大,变频能耗越大㊂导轮转速对总能耗的碳排放量和总碳排放量的影响曲线如图10所示㊂由图10可见,尽管4种能耗随着n D 的变大有增有减,但是总能耗和n D 的关系呈现先减小后增大的现象,当导轮转速在0.9338r /s 时,碳排放量最小㊂图10 导轮转速对总能耗碳排放和总碳排放的影响砂轮转速对材料去除能耗㊁响应能耗㊁变频能耗对应的碳排放量皆有影响,如图11所示㊂图11 砂轮转速对4种能耗碳排放的影响曲线㊃3841㊃无心磨削过程碳排放量及其关键影响因素解析郭登月程凯丁辉等Copyright ©博看网. All Rights Reserved.砂轮线速度v S正比于砂轮转速n S,切向磨削力F t正比于nε-1S;又因磨床去除材料削功率为P(t)=F t v S正比于nεS,因此砂轮转速越大,材料去除能耗越大㊂由图5可知,响应能耗中的R t与切向磨削力F t正相关,也即与nε-1S正相关,因此磨床响应能耗E r e s p o n s e与nε-1S正相关,而ε-1<0,所以n S越大,磨床响应能耗越小㊂基本能耗与砂轮转速无明显关系,不随n S的变化而变化㊂变频能耗包含导轮轴和砂轮轴,其中砂轮轴能耗和砂轮转速成二次关系,同样已在2.3节作了说明,并且在n S的实际范围内,转速越大,变频能耗越大㊂砂轮转速对总能耗的碳排放量和总碳排放量的影响曲线如图12所示㊂可见在允许范围内,砂轮转速越大,碳排放量越大㊂在加工方案三的条件下,以上分析为低碳磨削公理化第五层的功能需求和设计参数的设计提供了依据㊂对于F R211和D P211:F R2111表示选择最大进给率;D P2111表示满足加工要求下最大的进给率㊂有[F R2111]=[X][D P2111]图12 砂轮转速对总能耗碳排放和总碳排放的影响对于F R215和D P215:F R2151表示选择合理砂轮转速;F R2152表示选择合理导论转速;D P2151表示满足加工要求下砂轮转速取最小;D P2152表示导轮转速,取0.9338r/s㊂有F R2151F Réëêêùûúú2152=X0éëêêùûúúXD P2151D Péëêêùûúú2152图13所示为最终的低碳磨床公理化结构模型㊂由图13可见该结构矩阵为下三角矩阵,符合公理化独立性公理,底层设计参数是最高层功能需求 F R0:低碳磨削”的充分必要条件㊂图13 低碳磨削公理化模型㊃4841㊃中国机械工程第25卷第11期2014年6月上半月Copyright©博看网. All Rights Reserved.。

Analysis-Usingth...

Analysis: Using the effective organization of the game development process GDDHave you ever been in the game because of a lack of plan development process, design and gameplay constantly changing direction? You should consider using a game design document (ie, Game Design Document, hereinafter referred to as GDD. It is the overall guiding vision of the game, the game’s design, development and commercial aspects of the organization together ideas and plans.IntroductionSimply put: We all like to tell stories that some people really like, some people might not like so much, but the key is that we have spent a long time the idea of the story, with the passage of time, these stories started to evolve and become more. to the more complex, richer detail, background enrich the story is more complicated, and a new world from scratch so in our minds shape.As the story more complex, constructed the story of the world’s tools are more and more separated intoseveral different types of art, music has become more refined, the film also entered this world. Bring technology to enhance information sharing, dissemination of the arts to the world. every day to create new fantasy world. world is so colorful, so that people begin their desire to become part of a new concept was born.Although the electronic entertainment game begins just about maximizing points, developers quickly realized the unlimited potential of the game. Playing video games is not simply experiencing another story. This is the first description of himself in the story of how there say the media player can play a role, a difficult journey to experience and explore the world and mastery of that particular world skills, experience the hero’s victory and defeat.Game in unprecedented ways to connect with players and stories. Such contact can be established in many ways, the story takes place can be a fantasy world, which can be a particular role plump personality, which forced the players they want to try to see more stuff.Unfortunately, because the game is composed of so many different elements, and its production and requiresthe participation of different experts from different fields, so that coordinated the development process into a very difficult job. T o smooth coordination developer usually uses a thing called GDD.GDC is a tool to help organize parts of the game and it records the whole idea of the game in all aspects, from graphic design to the story line. Anyway it records the game concept, the project is finished forecasting and planning.Although not a key part of the production process of the preparation of GDD, but then the team has a great help, especially when projects developed by a large number of personnel involved. Additionally, there are many ways to write GDD of fact, different game development company The GDD is different, but in general, most of the games are to start production on these documents.So get down to business, here are a few important points of this tool you need to know.OutlineYou write game design documents have to tell people to read it, this game is kind of how this, you not only haveto explain the mechanism of the game, as well as the object of the game (game state Note: For example the protagonist, enemies, puzzles how between the arms and the environment is interactive, what is the theme of your game, what style is in GDD, these points are usually placed several major sections described.MarketingMarketing is a big chapter, can be divided into several sections, which explain the major commercial aspects of the game, such as target audience, deadlines, competitors and selling, etc. This section of the business has a very large significance, because it shows you The game is better than the opponent’s strengths and how to meet the needs of consumers in other words, it explains the appeal of your game.High ConceptBefore you start telling readers (who read the GDD how it works before your game, you must explain the core concepts of your game, that is succinctly expressed in the main aspects of the game, so that the reader will be able to anticipate what to say, and this GDD What is important to note that, so, GDD, there is a section on high-concept,so that the reader does not have to read the papers on all aspects of the game you will be able to have a general understanding.For example: If you tell the readers of your project is a futuristic space shooter, he can imagine the weapons appear in the game, activities, and other enemy is kind of how things should be.PlayThis section is the most important part of GDD, because it explains how to control objects in the game, how to make objects interact and how players perform activities, etc. In addition, it explains the flow of the game and the various events occurring part of the game.First minuteThis is a sub-section of section play, which explains the players in the game after loading the contents of the first to see it at this time to explain the events and reactions between the game and the players, to help understand the process of the game and method of operation, which is An important sub-sections, because it determines whether the game interesting.ProcessThis is a ratio of the ‘first minute’more detailed sub-section which describes all the players in the game options can be selected, which is a reflection of the results of each option produces a flow chart showing an overview of the entire game. Typically, this flow chart is composed of screenshots (for example, from the ‘Main Menu’ to ‘select points,’but you can also put the action and results on the inside (for example, if the player chooses ‘Master’role, all background will become associated with witchcraft, as shown in its title, this sub-section method to accurately explain the progress of the game.Victory conditionsIn this sub-section, you have to tell the reader what to do how to do to win the game, under what circumstances would fail to say, this sub-chapter explains the goal of the game.Number of PlayersThe game can be played by a specified number of people together is very important, because it determines the type of game or game modes supported - single or multiplayer, for example: split screen, LAN connections, network connections Note: This subchapter on ‘winningconditions’influential, because in competitive and cooperative game type game winning conditions are different.ArtAfter explaining how to play your game, you can explain your game look and style of art, which is also very important chapter, because it determines the coexistence of elements in the game world and the emotional impact of the players of the game, which is still A key point of the game marketing, as it shows the appearance of the game players feel and passed.T echnologyAnother chapter GDD must contain a ‘technical’because it determines the game requirements, operating platform, the development of the engine, and so this affects marketing, because the game will affect the applicable hardware player base and target audience - Consumer this game people.Is there a formula?You must remember that even though a number of the same sub-sections have different GDD, the production of such documents do not exist only way the so-called‘perfect formula’ does not exist. Every game designer has their own method of preparation, You must find your own way to fit it is very hard work, but in this article, I will provide some explanation of how the various sub-sections of GDD written skills - however, what sub-sections are designed for your game required , still depends on you.Your text must always remain clear and concise, preferably with a large number of illustrations, because they allow the reader to quickly imagine the final outcome of the game, and helps explain the puzzle (if you are in any game, and role, how between environment, monsters, weapons and other items are functioning.In addition, you can also add some help to understand the core of the game in a new topic in your GDD It should be noted that your game innovation and detail. Cases where, if your game has a new way to play the project, or special image concept or if it is to focus on the music (like game music, you should discuss T acitus in GDD in order to allow the reader to understand why the idea is good.DirectoryGDD best of ‘marketing’as the beginning of the chapter, because it is part of your investors and customersare most interested in, so you can make them faster to generate interest in your game. GDD independent game may not appear this chapter, because the game is usually no independent investors, however, if you think there is no other commercial purpose of the project, such as Apple’s free games, then you must record the relevant planning and marketing, because it is a very important issue plan significance.In addition, high concept is very important so that the reader can understand the core of the game right away and pay attention to its major aspects and you will find that in the GDD, usually at the beginning of the definition of basic and summative game with, and then gradually in depth all aspects of the game details.In the next section, you should explain the game, ‘play’, which contains the ‘first minute’, ‘process’, ‘winning conditions’ and ‘number of players’ and so on.After this section you must show your game appearance, which is discussed in the fine arts of the game, try to use a picture Finally, you can discuss the ‘particularity’ that explained: innovation, not all gameshave aspects such as plot, AI , roles, and other special settings.All things mentioned above are shown in the following flowchart, for you this is just a (general reference architecture should remember: There is no perfect formula for now, you’ve got GDD bones, you can article. ‘constitute’ to find this part of the chapter on the GDD a more detailed explanation.GDD (from dev.tutsplus)。

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Modelling the grain orientation of austenitic stainless steel multipass welds to improve ultrasonic assessment of structural integrity奥氏体不锈钢的多路模拟晶粒取向改善焊缝超声评价结构完整性J. Moysan a,*, A. Apfel a, G. Corneloup a, B. Chassignole bJ.莫伊桑A.阿普费尔G.科尔内卢帕 B.沙西尼奥尔aLaboratoire de Caracte´risation Non Destructive (LCND, EA 3153), Universite´ de la Me´diterrane´e, IUT Avenue Gaston Berger,13625 Aix-en-Provence Cedex, FrancebElectricite´ De France, Direction Etudes et Recherches, Les Renardie`res, 77818 MoretsurLoing, FranceReceived 1 August 2002; revised 4 February 2003; accepted 4 February 2003 AbstractKnowledge of the grain orientation quantifies the material anisotropy which helps to ensure the good ultrasonic testing of weldedassemblies and the assessment of their mechanical integrity. The model described here concerns the weld solidification of 316L stainlesssteel. The solidification of multipass welds made with a shielded electrode raises many unsolved modelling questions as it involves heat andfluid flow modelling in addition to soluteredistribution models. To overcome these difficulties we have developed the MINA model topredict the resulting grain orientations without using a complete solidification model. This model relies upon a phenomenologicaldescriptionof grain orientations from macrograph analysis. One important advance of this model is to include data reporting in the welding notebook thatensures the generality of the model. This model allows us to accurately simulate the ultrasonic testing of welded co mponents and to propose anew tool to associate welding design with the ultrasonic assessment of structural integrity.Keywords: Welding; Anisotropy; Modelling; Ultrasound; Structural integrity文摘晶粒取向量化材料各向异性的知识，有助于确保良好的焊接程序集和评估超声检测机械的完整性。

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Analysis of the different forms of application and types of cuttingﬂuid used in plunge cylindrical grinding using conventionaland superabrasive CBN grinding wheelsRodrigo Daun Monici a,Eduardo Carlos Bianchi a,*,Rodrigo Eduardo Catai b,Paulo Roberto de Aguiar ca Department of Mechanical Engineering,Sa˜o Paulo State University—UNESP Av.Eng.Luiz Edmundo Carrijo Coube,s/no.,Vargem Limpa,Bauru,SP CEP17033-360,Brazilb Department of Materials and Technology,Sa˜o Paulo State University—UNESP,Guaratingueta´,SP CEP12516-410,Brazilc Department of Electrical Engineering,Sa˜o Paulo State University—UNESP Bauru,SP CEP17033-360,,BrazilReceived15November2004;accepted5May2005Available online25July2005AbstractThe work reported here involved an investigation into the grinding process,one of the lastﬁnishing processes carried out on a production line.Although several input parameters are involved in this process,attention today focuses strongly on the form and amount of cuttingﬂuid employed,since these substances may be seriously pernicious to human health and to the environment,and involve high purchasing and maintenance costs when utilized and stored incorrectly.The type and amount of cuttingﬂuid used directly affect some of the main output variables of the grinding process which are analyzed here,such as tangential cutting force,speciﬁc grinding energy,acoustic emission, diametrical wear,roughness,residual stress and scanning electron microscopy.To analyze the inﬂuence of these variables,an optimisedﬂuid application methodology was developed(involving rounded5,4and3mm diameter nozzles and highﬂuid application pressures)to reduce the amount ofﬂuid used in the grinding process and improve its performance in comparison with the conventionalﬂuid application method (of diffuser nozzles and lowerﬂuid application pressure).To this end,two types of cuttingﬂuid(a5%synthetic emulsion and neat oil)and two abrasive tools(an aluminium oxide and a superabrasive CBN grinding wheel)were used.The results revealed that,in every situation,the optimised application of cuttingﬂuid signiﬁcantly improved the efﬁciency of the process,particularly the combined use of neat oil and CBN grinding wheel.q2005Elsevier Ltd.All rights reserved.Keywords:Optimised application;CBN grinding wheel;Cuttingﬂuid;Grinding1.IntroductionThe worldwide tendency is to produce ever more sophisticated pieces with high geometrical,dimensional and surfaceﬁnish tolerances,at low cost and without polluting the environment[1].Thus,the efﬁcient application of cuttingﬂuid in the cutting region is crucial.According to Ebbrell et al.[2],cuttingﬂuid beneﬁts the industrial sector in several ways,but it is often utilized incorrectly,thus generating substantial losses.Lubrication and cooling depend on the effective entrance ofﬂuid into the cutting region between the workpiece and the tool,which allows high volumes ofﬂuid to be reduced.According to Webster et al.[3],in the grinding process a jet ofﬂuid directly hitting the cutting region can signiﬁcantly reduce the temperature in this region,but highﬂuid jet velocities are needed to enable theﬂuid to penetrate the cutting region effectively.A marked drop in the cutting region temperature was recorded when a circular shaped nozzle was used instead of the conventional jet, which normally disperses theﬂuid widely.These authors also stated that,because of their low density,water-based ﬂuids should be used carefully.A great deal of dispersion may occur if they are applied with conventional nozzles,soInternational Journal of Machine Tools&Manufacture46(2006)122–131/locate/ijmactool0890-6955/$-see front matter q2005Elsevier Ltd.All rights reserved.doi:10.1016/j.ijmachtools.2005.05.009*Corresponding author.Tel.:C55142216119.E-mail addresses:bianchi@feb.unesp.br(E.C.Bianchi),tvsyso@.br(R.E.Catai),aguiarpr@feb.unesp.br(P.R.de Aguiar).efﬁcient nozzles should be used to prevent this kind of situation.In the present project,an appropriate methodology was employed to analyze the quantity of cuttingﬂuid applied in the process and its consequences.Based on this analysis,we investigated a new form of applying cuttingﬂuid aimed at improving the performance of the process with regard to the main output variables,such as tangential force,total speciﬁc grinding energy,acoustic emission,diametrical wear of the grinding wheel,roughness,and residual stress,using scanning electron microscopy(SEM).2.The grinding process and the material removal mechanismFig.1illustrates the plunge cylindrical grinding and chip removal processes.Fig.1(a)gives an overall view of the process and the main parameters that inﬂuence it,i.e., grinding depth,‘a’,grinding wheel diameter,‘d s’,surface speed of the grinding wheel,‘v s’,surface speed of the workpiece,‘v w’,diameter of the piece,‘d w’,length of the chip,‘l c’,andﬂux of heat generated by the cut,‘q’.Fig.1(b) depicts the mechanism whereby the chip is formed,from its plastic strain up to the formation of the chip itself,in the plane tangential grinding operation,which is similar to the chip forming process that occurs in the plunge cylindrical grinding operation.According to Malkin[4],in a great many cases,cutting ﬂuid does not substantially reduce the temperature in the grinding zone owing to the difﬁculties it encounters in penetrating that region,the small length of contact,and often due to the aerodynamic barrier generated by the grinding wheel surface,which has a V s velocity.The velocity at which the jet of cuttingﬂuid should penetrate the region of contact should be equal to the peripheral velocity of the grinding wheel so that the aerodynamic barrier is effectively breached,thereby enabling the cuttingﬂuid to perform its function in an optimised way[5].Guo and Malkin[6]found that cooling in the cutting zone is only effective in creep-feed operations,in which the high penetration and low velocity of the piece generate long contact lengths,as indicated in Fig.1(b),allowing theﬂuid to be drawn toward the cutting region and providing considerable cooling.However,when correctly applied, cuttingﬂuids allow for cooling of the workpiece as a whole (except in the instantaneous position of the cutting region), helping control dimensional and shape errors by subjecting the piece to lower thermal forces.Minke[7]stated that cuttingﬂuids reduce the tempera-ture in the cutting region,diminishing the occurrence of surface thermal damage of the workpiece.Through their lubricating properties,cuttingﬂuids reduce friction,thus reducing the wear on the top of the grains of the grinding wheel,generating less heat by decreasing the energy spent in sliding and‘plowing’.The mechanism of wear of the top of abrasive grains is illustrated in Fig.2,which shows that excessive wear of the cutting edges of the abrasive grains increases the contact surface considerably,leading to increased tangential cutting force,speciﬁc grinding energy,temperature,residual stress, etc.It is important to mention that because CBN grains are much harder than aluminium oxide and silicon carbide grains,CBN wheels have greater wear resistance than conventional wheels.Consequently,a CBN wheel usually gives better size holding and longer wheel redress life.In addition,the mechanical strength of vitreous bonds for CBN abrasives is usually much higher compared to conventional wheels of the same grain size.This is because CBN wheels are designed to have a lower wear rate and it is important that the grains are not easily lost by breaking away from the bond[8].Fig.1.(a)Parameters involved in the plunge cylindrical grinding process,(b)general chip formation mechanism(adapted from MALKIN,1989).R.D.Monici et al./International Journal of Machine Tools&Manufacture46(2006)122–1311233.Optimizing the application of cutting ﬂuidAccording to Campbell [9],the quality and cost of pieces are closely related with the way the cutting ﬂuid is applied to the cutting region.Optimizing the way cutting ﬂuid is applied in the process is an extremely important factor,not only from the standpoint of the overall costs of the process but also from that of the natural environment and the work environment.In situations where cutting ﬂuid is applied incorrectly,the piece may undergo thermal damage through burning and surface stresses.Fig.3gives an example of optimised application of cutting ﬂuid,showing a device to optimize the application of cutting ﬂuid in the grinding process.Campbell [9]proposed a similar optimization,for which he designed a steel device that minimized the aerodynamic barrier effect generated by the grinding wheel.This device consisted of a metal plate (considered a metal deﬂector)positioned close to the grinding wheel surface at a distance of about 30m m,which enabled the grinding wheel rotation to rise from 2500to 3000rpm,considering the same cutting ﬂuid pressure existing close to the grinding zone.According to Runge and Duarte [10]and Motta and Machado [11],cutting ﬂuids can perform one or more functions,which may comprise cooling of the tool and theworkpiece,elimination of chips generated in the process,and lubrication of the piece-tool contact region through the reduction of friction,minimizing tool wear and hence increasing its service life.Added to this is its contribution to reduce the generation of heat in the cutting region,control the appearance of sham edges—in the case of tools with a deﬁned geometry,its cleaning power by expelling chips in the cutting region and,in the case of grinding operations,reducing the tendency for clogging of the grinding wheel pores during the cutting operation,as well as providing anticorrosion protection.The relative importance of each of these functions also depends on the machined piece,the type of tool employed (deﬁned or undeﬁned geometry),the machining conditions,the surface ﬁnish and the dimen-sional control required.The application of cutting ﬂuid at high velocities directed effectively at the cutting region reduces the tangential cutting force and normal cutting force by 50%under certain machining conditions.The use of high velocity cutting ﬂuid offers the advantages of improving the cooling/lubricating capacity in the machining region provided by the cutting ﬂuid,reducing the mechanical loads on the tool and improving the roughness (R a )value.Thus,it can be stated that the output variables of the process lead to a considerable improvement of its overall performance.Webster and Ciu [12]reported that the application of cutting ﬂuid in machining processes is becoming an increasingly important factor due to its high chip removal rates,high quality and increased grinding wheel service life.The choice of an efﬁcient application method is considered one of the ways to achieve productivity goals that may be as important as the speciﬁcations of the cutting tool.It should be noted that the use of CBN grinding wheels has grown considerably and that cutting ﬂuids are increasingly required on a global scale.The optimised application of water-based (emulsion)cutting ﬂuids through high pressure is more difﬁcult than that of neat oils because of the lower viscosity of the former,which increases the possibility of dispersion of thespray.Fig.2.Wear mechanism and increase in contact area of abrasive grains (adapted from MALKIN,1989).Fig.3.Example of a device used to reduce the aerodynamic barrier.R.D.Monici et al./International Journal of Machine Tools &Manufacture 46(2006)122–1311244.MethodologyIn this section,we describe the methodology developed to carry out this research,as well as the equipment utilized for it.4.1.Application nozzles and types of cuttingﬂuid usedThe laboratory tests were conducted using a CNC cylindrical grinding machine with an optimised cutting ﬂuid application system using nozzles proposed by Webster [5],based on the unit velocity relation between the grinding wheel and the jet of cuttingﬂuid applied in the process. Fig.4illustrates the Webster nozzle design proposed by Webster[5],which allows for the application of cuttingﬂuid at the same tangential velocity as that of the tool in order to achieve greater process efﬁciency,as noted by that researcher.The3mm diameter Webster nozzle supplied an average outﬂow of14l/min,thus generating a tangential velocity of 33m/s,which was used as aﬁxed machining parameter in all the tests.The outﬂow supplied by the grinding wheel’s conventional nozzle was about84l/min,i.e.six times greater than the outﬂow used with the Webster nozzle.In addition to the difference in outﬂow of the two cuttingﬂuid application methods used here,there was also a signiﬁcant difference in the pressures,particularly in that of the Webster nozzle.The conventionally appliedﬂuid generated an effective injection pressure in the order of0.392MPa, while the optimised system generated a pressure of approximately0.549MPa.This difference in pressure allowed the cuttingﬂuid to penetrate the cutting region effectively,preventing the jet of ﬂuid from dispersing at the moment of its application,a common occurrence when using conventional cuttingﬂuid application systems.The cuttingﬂuid applied in all the tests consisted of a synthetic emulsiﬁer in a5%concentration, composed of extreme pressure(EP),biocide,bactericide, fatty amides,anticorrosive and antifoaming additives prepared in an aqueous solution.The other cuttingﬂuid was neat oil,which was used directly in the tests without the need for any previous preparation.4.2.Machining conditionsThe machining conditions used in this work were based on a statistical survey carried out in the industrial park of the Sa˜o Paulo metropolitan area(Brazil).The initial diameter of the workpieces was68mm.The volume of material removed in each test(represented a decrease of10mm of the material’s diameter)clearly indicated that this condition required the maximum efﬁciency from the combined tool/ﬂuid/mode of application,making the results compa-tible with the prevailing industrial conditions.A tangential grinding wheel velocity of33m/s was used, equal to that of the velocity of the cuttingﬂuid jet supplied by the nozzle proposed by Webster[5].The tests were designed based on machining cycles,which were respon-sible for a100m m advance of the grinding wheel on the test specimens’diameter,with a grinding width of3mm and spark out time of8s.The2968.8mm3of material removed from the test specimens represented100machining cycles, corresponding to a complete test for each set of input parameters proposed.The dressing operation on the conventional grinding wheel was carried out with a single-point diamond dresser and an overlap factor(Ud) equal to1was achieved.The proﬁling operation performed on the superabrasive grinding wheel used a diamond ﬂiese—a modern universal dressing tool for proﬁling and straight dressing—and was constant in all the tests.It is worth noting that three tests were conducted for each proposed condition in order to ensure repeatability,as will be discussed later.4.3.Set-up of the test bench and data acquisition softwareThe general data acquisition system of the output variables monitored here is illustrated in Fig.5.The tangential cutting force data was acquired through a gauge circuit that measured the power required by the grinding wheel induction motor.The system was calibrated with a torquemeter,which provided a calibration equation respon-sible for measuring the torque as a function of the power required by the grinding wheel shaft.Based on this calibration equation,a data acquisition programwasFig.4.Webster and conventional nozzles for cuttingﬂuid application used here.R.D.Monici et al./International Journal of Machine Tools&Manufacture46(2006)122–131125designed into which were inserted the main aforementioned input parameters.Although the speciﬁc grinding energy (J/mm 3)is an output variable related directly to the tool’s tangential cutting force (N)and peripheral velocity,it is affected by other parameters,as can be seen in Eq.(1):e c Z F tc V s p d w v f b(1)The speciﬁc grinding energy was calculated by the software designed with Labview 5.0.1programming language,and parameters such as the test specimen diameter ‘d w ’of 60mm were inserted into the program in each test.The tool’s advance velocity ‘v f ’of 1.5mm/min and the grinding width ‘b ’of 3mm were also inserted into the program.The tool’s peripheral velocity was monitored by means of an encoder (Fig.5)installed on the grinding wheel shaft,whose used diameter was 350mm.Thus,the program calculated the velocity through Eq.(2),based on the shaft’s diameter (d)and rotation (n)supplied by the encoder:v s Z p dn(2)The remaining output variables analyzed here were measured after 100grinding cycles and did not require mathematical equationing.5.Results and discussionThe results obtained for the output variables of the process analyzed in this research work and described below represent the average value of three test specimens measured,with the exception of the residual stress and SEM values,which represent only one test specimen.The values of tangential cutting force and speciﬁc grinding energy presented here correspond to the maximum points achieved in each grinding cycle.5.1.Results of the tangential cutting forceFig.6compares the two types of cutting ﬂuid applied by the conventional and optimised methods,using the super-abrasive CBN grinding wheel in the grinding operation proposed in machining cycles.Na analysis of Fig.6shows that the performance achieved with the neat oil was superior to that obtained with the synthetic emulsion in the two application modes.In addition to this effect,one can also analyze the gradual reduction of the tangential cutting force obtained with the use of the neat oil with both ﬂuid application methods.The emulsion led to a certain stabilization of the tangential cutting force through loss of the material removalcapacityComputerprogramSignal conditioning circuitTangential cutting forceAcoustic emissionFig.5.Overall scheme for obtaining data on the output variables monitored by the software.R.D.Monici et al./International Journal of Machine Tools &Manufacture 46(2006)122–131126of the abrasive tool,causing a slight increase in tangential cutting force.The superabrasive CBN grinding wheel displayed a higher capacity to remove material with the neat oil,which allowed the tool’s cutting edges to remain sharp for a longer period during the process of removing material from the test specimen,which was not the case when the 5%synthetic emulsion was employed.It is worth noting that the work environment generated through the use of neat oil is highly aggressive,producing dense particles that remain suspended in the region around the machine and damaging the health of the machine operators,who inhale these particles.However,it is important to point out that neat oil or emulsion fumes should not be allowed to pollute the environment of the operators.Machine enclosure and extraction fans should be provided where necessary as well as the ﬁre risk must be avoided.Fig.7depicts the behaviour of the tangential cutting force using the conventional grinding wheel.As can be seen,the behaviour of this variable stabilized after just a few machining cycles because of this tool’s low capacity to maintain its cutting capacity.Again,note the considerably superior performance of the process with the optimised ﬂuid application resulting from the reduction in load on the tool.This behaviour resulted from the greater efﬁciency in cutting ﬂuid penetration into the grinding wheel/piece cutting region through the effective breakdown of the air barrier created by the rotating movement of the grinding wheel.Hence,the optimised system prevented the ﬂuid from dispersing during its application,as in the case of the conventional ﬂuid application method,which failed to ensure the effective penetration of the cutting ﬂuid to the tool/piece interface.5.2.Results of the speciﬁc grinding energyThe values of speciﬁc grinding energy for the CBN grinding wheel,aluminium oxide grinding wheel and the remaining parameters are illustrated in Figs.8and 9.These ﬁgures conﬁrm the results obtained for tangential cutting force since,as mentioned previously,the speciﬁc grinding energy is directly related to the tangential cutting force.One can state that the use of neat oil in grinding operations signiﬁcantly reduces the energy involved in the process,particularly when using conventional grinding wheels,whose abrasive grains are constantly renewed and which possess a greater capacity to lodge cutting ﬂuid in their pores due to the structural characteristics of these tools.The opposite behaviour was found with the use of the synthetic emulsion,whose use allowed the CBN grinding wheel to perform more efﬁciently through its capacity for sustaining the sharpening during the process because it wears more slowly,allowing its cutting edges to berenewedFig. parative analysis of the cutting ﬂuids and methods of application,using the superabrasive CBN grindingwheel.Fig.8.Speciﬁc grinding energy for the superabrasive CBN grinding wheel,and remaining inputparameters.parative analysis of the two ﬂuids and application methods,using the conventional aluminium oxide grinding wheel.R.D.Monici et al./International Journal of Machine Tools &Manufacture 46(2006)122–131127throughout the process through the microeffect generated by the proﬁling operation.Fig.10shows the behaviour of the two grinding wheels using neat oil,indicating a considerable difference between the values of speciﬁc grinding energy.Note that,from the 70th cycle on,the performance of the superabrasive CBN grinding wheel showed results compatible with those of the conventional grinding wheel in respect to its excellent capacity to maintain the sharpness of its abrasive grains through the micro-fracturing of its cutting edges generated by the proﬁling operation.The CBN grinding wheel proved to be a tool that can maintain and even reduce the mechanical loads on its surface even under severe conditions,as indicated by the replacement of neat oil for the 5%synthetic emulsion discussed earlier herein.Another observation was that,even under the best condition found for the conventional grinding wheel,this tool was not able to exceed the performance of the superabrasive CBN grindingwheel,a fact that corroborated by the wear displayed by the conventional tool,as shall be discussed later.Fig.11shows the results of speciﬁc grinding energy for the two tools tested,using the 5%synthetic emulsion.This ﬁgure reveals that the performance of the CBN grinding wheel using synthetic emulsion was superior to that of the conventional tool,and that the performance of the conventional grinding wheel using the optimised cutting ﬂuid application method was comparable to that of the superabrasive CBN grinding wheel using the conventional ﬂuid application method.The lower lubricating power of the synthetic emulsion allowed the CBN tool to effectively display its high material removing power and its capacity to maintain its cutting edges.Another characteristic that was veriﬁed was the inability of the conventional grinding wheel to retain the emulsion in its pores,which it does when using neat oil.The 5%synthetic emulsion is considerably less dense than the neat oil,so it is present in the grinding wheel’s structure in considerably lower amounts.5.3.Results of the acoustic emission (AE)Fig.12shows the AE results,indicating that the values of the AE signals (rms)were substantially lower with the optimised mode of ﬂuid application.This tendency was expected due to the behaviour of the tangential cutting force and speciﬁc energy.Note that the difference in the mean values of acoustic emission obtained throughout the tests,according to the conditions proposed here,was more marked when the two types of grinding wheel were used with the optimised application of neat oil,for the conventional aluminium oxide grinding wheel showed signiﬁcantly greater radial wear than did the superabrasive tool,enabling its abrasive grains to remain constantly sharpened through their extensiverenewal.Fig.9.Speciﬁc grinding energy for the conventional aluminium oxide grinding wheel,and remaining inputparameters.parison of the performance of the conventional and superabrasive CBN grinding wheels with conventional and optimised application of neatoil.parison of the performance of the conventional and superabrasive CBN grinding wheels with conventional and optimised application of 5%synthetic emulsion.R.D.Monici et al./International Journal of Machine Tools &Manufacture 46(2006)122–131128The optimised application of cutting ﬂuid led to a signiﬁcant reduction of the average acoustic emission of the process in every situation,for this method allowed the cutting ﬂuid to effectively penetrate the cutting region by overcoming the air pressure in the cutting region generated by the tool’s rotating surface.5.4.Results of the grinding wheel’s diametrical wear The diametrical wear of the tool shown in Fig.13was measured after 100grinding cycles under each machining condition.Once again,all the optimised situations of cutting ﬂuid application effectively reduced the diametrical wear of the grinding wheels by reducing the mechanical load on their surface resulting from the lower friction and heat generated in the cutting region.The greater amount of ﬂuid in the cutting region prolonged the tools’service life,for their material removal performance improved as a result of the greater durability ofthe abrasive grains.The higher injection pressure of the cutting ﬂuid and the absence of relative velocity between the jet of ﬂuid and the tool provided by the optimised method enabled larger amounts of ﬂuid to be present in the cutting region,enhancing the lubricating and cooling properties of each type of ﬂuid used,thus allowing for a considerable increase in the productivity of the process.5.5.Roughness resultsSix measurements were taken of each test specimen and the value presented in Fig.14represents the average of the respective measurements.The cut-off used was 0.25mm.Analyzing Fig.14,one can see that the average roughness dropped when the ﬂuid application method was optimised.This was due mainly to the better lubrication provided by the optimised method,allowing the ﬂuid to penetrate more effectively into the grinding wheel/test specimen contact region.Also note that the neat oil presented lower roughness values,mainly due to its greater lubricating capacity in comparison with the synthetic ﬂuid.As for the type of grinding wheel,the superabrasive tool presented a signiﬁcantly better performance than the conventional one.It should be noted that the CBN grinding wheel displayed a similar behaviour with both ﬂuid application methods owing to its excellent capacity to remove material because it maintains its sharpness throughout the process,without requiring successive sharpening.The lower values of mechanical load discussed earlier reﬂect the low values of roughness achieved in relation to the conventional grinding wheel.The roughness values obtained conﬁrm that the use of emulsive synthetic ﬂuid generated greater mechanical loads,but its effect was minimized as the cutting ﬂuid application method was optimised,especially with the conventional grinding wheel.Conventional grinding wheel (conventional nozzle)Conventional grinding wheel (Webster nozzle)CBN grinding wheel (conventional nozzle)CBN grinding wheel (Webster nozzle)Coolant typeA c o u s t i c e m i s s i o n (r m s ),V0.400.300.200.100Conv.optim.Conv.optim.Conv.optim.Conv.optim.Fig.12.Acoustic emission signal (rms)for the conventional and superabrasive grinding wheel using optimised and conventional application of 5%synthetic and neat oil cutting ﬂuids.Conventional grinding wheel + Emulsion Conventional grinding wheel + Neat oil CBN grinding wheel + EmulsionCBN grinding wheel + Neat oil Coolant typeD i a m e t r i c a l w e a r , µmreduction of 12.3%Conv.8007006005004003002001000Optim.Conv.Optim.Conv.Optim.Conv.Optim.reduction of 34.8%reduction of 42.2%reduction of 54.1%Fig.13.Analysis of the performance of the process,indicated by the tool’s diametrical wear,according to the input parameters employed.Conventional grinding wheel + Emulsion Conventional grinding wheel + Neatoil CBN grinding wheel + Emulsion CBN grinding wheel + NeatoilR o u g h n e s s (R a ), µm3.02.52.01.51.00.50Conv.543Conv.543Conv.543Conv.543Different types of nozzlesFig.14.Average values of roughness for the two grinding wheels,varying the ﬂuid application nozzles.R.D.Monici et al./International Journal of Machine Tools &Manufacture 46(2006)122–131129。