Thèses sur le sujet « Coining die »

Coins and medallions are manufactured by using coining process which is a metal forming process. In coining of medallions, there is a strong need to shorten the production time and reduce the production cost and waste of material in conventional coining method. An alternative coining method may be considered in order to reduce the production time and the manufacturing cost. In this study, a new method has been proposed. In the proposed method, design of the medallion is performed by utilizing computer aided engineering (CAE) environment and the master die is manufactured by means of NC codes. The modular designs of blanking and coining die sets for medallions with a diameter in the range of 30-90 mm have been realized. Coining and blanking processes for production of the medallion have been simulated by using a commercial finite volume program. Moreover, a commemorative medallion for the opening ceremony of METU-BILTIR Center Forging Research and Application Laboratory has been designed. After die sets have been manufactured, the real-life experiments have been conducted by using 1000 tones mechanical forging press and 200 tones eccentric press available in Forging Research and Application Laboratory of the METU-BILTIR Center. The results have been compared with the computer simulations. After the real-life experiments, it has been observed that medallions have successfully been obtained by employing the new proposed method. Therefore, the new proposed method for coining has been verified.

This thesis offers an archaeological and ethnographic examination of the coin-tree custom, which is essentially what its name suggests: the practice of inserting coins into trees. These trees are often in the form of logs or stumps, and they are commonly located beside well-traversed footpaths in rural/semi-rural areas. The custom can be traced back to the 1860s in Scotland, but has experienced a late 20th/early 21st-century renaissance, with clusters of coin-trees emerging across England, Wales, Scotland, Northern Ireland, and the Republic of Ireland. No previous academic attempt has been made to either catalogue these structures or contextualise the practice; it is the aim of this thesis, therefore, to do both. Proffering a catalogue of 197 individual coin-trees distributed across 34 sites (detailed in the appendices), this thesis draws on a wide range of resources in order to elucidate the custom: literary works, both historical and contemporary; the empirical data of the coin-trees themselves; and the ethnographic material of over 200 participant interviews. The history of the custom is traced, including a consideration of why it has experienced a recent resurgence – particularly at a time popularly conceived of as a ‘secular age’. The questions of how and why people participate are examined in detail, revealing a mutability to the ‘meaning’ of the custom, and a consideration of the future and heritage of the coin-tree structures themselves is also offered. The thesis closes with a suppositional vignette: what would an archaeologist find if she uncovered a coin-tree site in the future? How would she interpret the remains? And what does this reveal about archaeological methodologies, ritual interpretations, and the relationship between folklore and material culture?

The project conceived within engineer’s studies of branch 2303T002 is subbmitting a proposal for radial bearing cage produce technology. It is also subbmitting a design solution to functional parts for blanking the “windows” and coining the “locks”. The cage will be made from sheet steel 11 300.29. This cage should replace the current one machined from the brass Ms 58 Al. According to the literary research and development experiences of the company ZKL Brno, a.s., two pairs of tools were designed. First one for blanking the “windows” and second one for coining the “locks”. Blanking punch, blanking die and coining punch will be made from the steel 19436, coining die will be made from the steel 19312. Heat-treating process will be accomplished according to the enclosed drawings. Both pairs of tools will be mounted in the press LENR 63 AU (manufactured by the company ŠMERAL Trnava), with nominal force 630 kN.

The study of place-names containing personal names is a neglected field in onomastics, despite being of great significance in various areas of name-studies. At its core, this thesis will begin to bridge the gap between the study of place-names and personal names, both practically and theoretically. The first step is to introduce a formally accepted terminology for the study of these names. Here, the term used to describe a place-name containing a personal name is anthropo-toponym. The acknowledgement of such a term would aid and indeed encourage future studies of anthropo-toponyms, both in Scotland and elsewhere. The study is approached through a close investigation of name material from the Isle of Lewis. The toponyms in question are characterised by two main linguistic layers, Old Norse and Scottish Gaelic, both of which have been included here. Although this material is partially an exercise in investigating the characteristics and properties of anthropo-toponyms, it also sheds considerable light on the social and linguistic history of Lewis place-names. Additionally, the study draws on a considerable amount of comparative evidence. This is primarily collected from the comprehensive survey of The Place-Names of Fife by Simon Taylor with Gilbert Márkus (2006-12). However, when studying the Norse dimension further, material from Landnámabók, one of the key sources for the medieval settlement of Iceland, has also been included. One of the most significant proposals made in this thesis is the concept of using a variant of the name-semantic approach, previously discussed by Peder Gammeltoft (2001a) in a Scottish context. At its core, this means that rather than emphasising the etymology of individual place-name elements, the motivation for coining is emphasised. It will become evident that using this approach makes it possible to view anthropo-toponyms in a different light. Through this method, we find that there is considerable variety to be found within the name-material, particularly when we look at the social and cognitive factors at play when place-names are coined and transmitted. Place-names that, on the surface appear to be relatively homogenous, can prove to be the opposite. For example, names such as Creagan Iain Ruaidh, Geodha Bean, Mhurchaidh, Stac Dhomhnuill Chaim and Tigh Mhaoldònuich, which are all coined in a comparable social Gaelic setting in the early modern period, appear to represent motivations relating to a birth, a drowning, the abode of a notorious outlaw, and the temporary hideout of a sheep thief respectively. By emphasising these micro-narratives, it is possible to shed light on the name material from a new perspective and to provide a greater understanding of the process of coining place-names.

Le cognassier du Japon est un arbuste nain de la famille des Rosaceae dont les fruits, très arômatiques et très acides sont riches en fibres et en polysaccharides pariétaux. La teneur en fibres des fruits de douze génotypes de l'espèce japonica et d'un de l'espèce speciosa a été déterrninée par deux méthodes différentes: la préparation de Matériel Insoluble à l'Alcool (MIA) et la méthode AOAC (Association of Official Analytical Chemists). Les deux méthodes, bien que différentes permettent de mettre en évidence une variabilité intra--espèce importante. Les fibres représentent entre 28 et 38% du fruit sec et sont principalement localisées dans la pulpe. Les parois de coing sont riches en pectines (1,4g pour 100g de fruit frais) qui proviennent également essentiellement de la pulpe. Elle contiennent environ 0,4g d'hémicelluloses pour 100g de fruit frais. Le résidu cellulosique issu des parois représente 2,6g/lOOg de fruit frais. Une méthode simple, rapide et fiable a été mise au point pour sélectionner les fruits en fonction de leur teneur en pectines. La majeure partie de ces pectines est extraite en milieu acide dilué à chaud. Elles sont hautement méthylées, ont un taux de branchement élevé et sont riches en oses neutres (arabinose et le galactose, principalement). Leur viscosité intrinsèque est d'environ 300mL/g. Les pectines extraites par l'eau et par l'oxalate de potassium ne représentent qu'un faible pourcentage de la totalité des pectines extractibles. Elles sont néanmoins intéressantes puisque leur viscosité intrinsèque est très élevée (supérieure à 650mL/g).

A number of aspects of the coining process are investigated, both through experimentation using several types of tooling using blanks made of copper 110 or brass 260, and by developing and using a FEA model. Several relationships have been found which describe the effects of changing the type of coin blank or the geometry of the coining tooling on how much volume of the coin is formed at different forces. The open-die bulk upsetting test was used to find the true stress and strain curves of both materials, and the ring test was used to determine the coefficient of friction. Coins were made over a large range of forces in order to test the general nature of how the diameter and design of a coin are formed. While the diameter begins to increase, the thickness of the coin reduces and material is pushed into the punch cavity, filling the design’s volume up rather linearly. Tests on the effects of changes in the wall angle were inconclusive. As the punch design depth increased the force requirement went down in a manner roughly inverse to the ratio of the increase in depth. Effects of coining with a punch on one side versus two sides were tested. Effects of the perimeter of the punch design showed that a longer perimeter actually reduced the forces required for thinner coins, a difference that got smaller as the coin blanks got thicker. Blanks required 1.4 times the force to form than a coin half its thickness. A direct correlation of forming force to the yield stress of the material was expected but rather appeared to be related to the full nature of the true stress-strain curves. The FEA model was able to match experimental results relatively closely, but only up to about 333.3 kN, the lowest force used for the bulk of the experimental samples. The FEA model provided a good look into what happens to the coin while it is under load and the mysteries of ghost coining were unveiled.
Thesis (Master, Mechanical and Materials Engineering) -- Queen's University, 2013-03-01 06:28:50.729

碩士
國立臺灣科技大學
機械工程系
97
This study investigates the formability of AZ31 magnesium alloy sheet for flange compression and coining process under hot forging. Finite element software, DEFORM, is applied to simulate the forming behaviors. The process parameters considered in this study are heating temperature of the sheet, punch speed, flash thickness and constant friction factor. The variation of forming loads under flange compression and coning process are discussed due to the change of process parameters. Besides, flange compression and coining experiments are carried out, the results are compare with the DEFORM simulation. The obtained forging loads and formed shapes are in good agreement with the experimental results. The validity of the simulation model established in this study can be confirmed. Finally, from the measurement of hardness and metallographic observation of forged part, the influence of forming temperatures on the strengths and microstructures of magnesium alloy under forging process can be evaluated.

碩士
國立高雄應用科技大學
模具系碩士在職專班
106
The demand for the product miniaturization in many fields leads to enormous increases in research and development of manufacturing micro components in academia and industries. Micro metal forming is one of important processes for fabricating microscale metal components. However, the size effects may increase the influence of the grain size of metal and could cause issues on the material flows during the metal forming process at micro scale. This study investigated the effect of grain size and ultrasonic vibration on the coining process of copper at micro scale. The study employed annealing to adjust the grain size of pure copper. The average grain sizes of the wires from different treatments, the as-received, annealed at 580ºC and annealed at 800ºC, were 12.9 um, 63.8 um, and 154.1 um, respectively. The copper wires were then precisely machined as billets with 1 mm diameter and 1 mm height for the use in the experiments of the micro coining process under two forming conditions, with and without ultrasonic vibration. Moreover, the study also employed commercial finite element software to predict the load, deformation and die filling of the process. The results showed that grain size is an important factor affecting the micro coining process of copper. There is an improvement in the coined patterns for the cases with smaller grain size. Moreover, the ultrasonic vibration greatly affects the material flow and leads to better die filling, and significantly reduce the forming load.

Please read the abstract in the section 00front of this document
Dissertation (MEng (Mechanical Engineering))--University of Pretoria, 2006.
Mechanical and Aeronautical Engineering
unrestricted

This study is in the area of terminology activities in Zimbabwe and it analyses the term creation used in the following selected specialised terms dictionaries: Duramazwi Reurapi Neutano (Dictionary of Biomedical Terms), Duramazwi Remimhanzi (Dictionary of Shona Musical Terms), and Duramazwi Redudziramutauro NeUvaranomwe (Dictionary of Shona Linguistic and Literature Terms). The study specifically analyses and explores how terminographers together with health, music, language and literature specialists made use of their term creation skills and strategies in the creation of new specialised terms for the field of music, health and linguistics. In addition, this research takes into account the impact of factors such as culture, socio- economic, etymological purity, attitudes of the target users, language policy, as well as availability of resourceson term creation. Hence, term creation is an exercise that involves many aspects and interlinked factors. This research advances the argument that while some term creation strategies (compounding, coining and derivation) can be adequate and appropriate, however, at times; they are some which result in created terms that are rather cumbersome, vague, artificial, and difficult to master and remember. In addition, this study found out that some term creation strategies (semantic expansion and loan translations) are unproductive; that means they do not add any value on the Shona language vocabulary. Moreover, the borrowing term creation strategy was analysed on the basis of whether it is promoting and elevating the Shona language or is it undermining its value and vitality. This study emphasises the need for a collaborative approach to term creation, with terminologists, linguists, subject area specialists and target language users during the different phases of word formation processes for the collective ownership of the created term and their acceptability to the target users. This study highlights that, through good term creation strategies the Shona Language can significantly contribute to the promotion and development of Shona language in Zimbabwe. Overally, the research yields a substantial amount of information in the terminological formation processes as well as the identification of factors that can be used to improve term creation strategies in order to develop indigenous languages for use in all spheres of life.The major contribution of this study is the identification and highlighting of the major strength and weaknesses of term creation strategies as a way of developing indigenous languages. The useful findings in this study will benefit the indigenous language development and language policy planners and terminologists in Zimbabwe and other African languages in similar situations. The significant amount of information about term creation that was used in the analysis of term creation in the three dictionaries was solicited from questionnaires and interviews that were carried out with linguists, the specialised dictionary compilers, music students, medical students and high school students doing Shona language and literature subject in Zimbabwe. More information on the term creation was done through content analysis of the three specialised dictionaries and the present researcher’s own experiences as a former Shona high school teacher, linguist and above all as a Shona language speaker.
African Languages
D. Litt. et Phil. (African Languages)