Global ETD Search

11	Finite Element Modeling and Validation of a Novel Process for Extruding Thin Wall Hollow Copper Profiles Laing, Jeffrey M. 18 April 2012 (has links) No description available. Engineering Mechanical Engineering Finite Element Micro Channel Extrusion Hollow Profile High Extrusion Ratio Multi Billet Copper Extrusion
12	Liejimo slegiant formų projektavimo, gamybos technologinio paruošimo ir gamybos problemų analizė ir sprendimai / Analysis and solutions in desing, production technology and production problems of plastic injection moulds Štrimaitis, Mantas 23 June 2009 (has links) Baigiamajame magistro darbe nagrinėjamos liejimo slegiant formų projektavimo, ga-mybos technologinio paruošimo bei gamybos proceso problemos ir aptariami novatoriški jų sprendimo būdai. Apžvelgiami plastinių medžiagų perdirbimo procesai. Analizuojamas tradi-cinis liejimo slegiant formų gamybos procesas ir jo trūkumai. Pateikiami organizaciniai ir te-chniniai tradicinio gamybos proceso tobulinimo būdai, panaudojant naujausią programinę įrangą, įrankius, medžiagas ir stakles. Tiriamojoje dalyje atliekamas ruošinio parinkimo įtakos liejimo formos detalių savikainai modeliavimas. Išanalizavus visas liejimo slegiant formų ga-mybos problemas, pateikiamos baigiamojo darbo išvados ir siūlymai. Darbą sudaro 7 dalys: įvadas, plastikų perdirbimas, tradicinio liejimo slegiant formų gamybos proceso analizė, liejimo slegiant formų gamybos proceso šiuolaikinės tobulinimo kryptys, ruošinio parinkimo įtakos liejimo formos detalių savikainai modeliavimas, išvados ir pasiūlymai, literatūros sąrašas. Darbo apimtis – 73 p. teksto be priedų, 50 iliustr., 14 lent., 21 bibliografinis šaltinis. Atskirai pridedami darbo priedai. / In this final master work are investigated plastic injection moulds design, production technological preparation and production problems and discussed innovative solution ways of these problems. Reviewed remake processes of plastic meterials. Analysed tradicional plastic injection mould production process and its weaknesses. Gived organizational and technical tra-dicional production process improvement ways handling the modern software, tools, materials and machines. In investigational part is performed modeling of billet selection influence to cost price of mould parts. After analysis of all the plastic injection moulds production problems gived conclusions and suggestions of this final work. Structure: introduction, remake of plastics, traditional plastic injection moulds production process analysis, modern improvement ways of plastic injection moulds production process, modeling of billet selection influence to cost price of mould parts, conclusions and suggestions, references. Thesis consist of: 73 p. text without appendixes, 50 pictures, 14 tables, 21 bibliographi-cal entries. Appendixes included. Mechanical Engineering Plastikų perdirbimas Liejimo slegiant forma Automatizuoto projektavimo sistemos Skaitmeninis programinis valdymas Ruošinio parinkimas Remake of plastics Plastic injection mould Automated design systems Computer numerical control Billet selection
13	Měření povrchové teploty pomocí infračervené kamery / Surface temperature measurements by IR camera FUKA, Miloš January 2014 (has links) The master's thesis is devoted to the history and performance of non-contact temperature measurement, characterization of infrared cameras and infrared thermometers. Temperature is one of the most important physical quantities. Using an infrared camera we obtain information about the surface temperature in all picture. In the master's thesis is included the measurement and capturing the fatal defects on the punched billet, finding out the quality of temperature field and the quality of the overlapping work rolls. During the measurements were used infrared cameras TIM200, TIM400 from the company Micro-Epsilon and infrared cameras SC325, SC660 from the company Flir.
14	Разработка и освоение технологии производства холоднодеформированных труб из сплава Ti-3Al-2,5V : магистерская диссертация / Development and application of production of cold-formed tubes technology from Ti-3Al-2.5V alloy Рябов, И. С., Ryabov, I. S. January 2023 (has links) Целью работы является разработка и освоение технологии производства холоднокатаной бесшовной трубной заготовки типоразмера из титанового сплава методом холодной прокатки. Составлена общая технологическая схема процесса производства: рассчитаны число проходов, размеры труб по проходам, расходный коэффициент, производительность, назначены основные и вспомогательные операции, режимы данных операций. Проведены расчеты основных параметров процесса прокатки, необходимые для его дальнейшей реализации в производственных условиях: рассчитаны калибровки прокатного инструмента, рассчитаны энергосиловые параметры процесса прокатки. Описаны особенности новой технологии. Представлено описание основного деформирующего оборудования, проведены расчеты на прочность деталей стана холодной прокатки. Проведены различные испытания, в том числе контроль механических свойств, контроль микроструктуры. Результаты испытаний показали, что трубы соответствуют требованиям нормативной документации. / The objective of the work is to develop and implement the production technology of standard size cold-rolled seamless pipe billet made of titanium alloy by cold rolling method. The general technological scheme of the production process was drawn up, in addition to that the number of passes, pipe sizes by passes, consumption factor, productivity, main and auxiliary steps, modes of these operations were calculated. As the next step, the calculations of the rolling process main parameters necessary for its further implementation in production conditions were carried out; these include: calculation of rolling tool calibration, calculation of rolling process energy and force parameters (rolling force, rotational moment, rolling power). After that the new technology characteristics were described. This work presents a main deforming equipment description, and strength calculations of cold rolling mill parts have been also carried out. As part of the work, various tests were performed, including mechanical properties inspection, microstructure monitoring. The test results showed that the pipes produced as a result of the work meet the requirements of the reference documentation. ТИТАНОВЫЙ СПЛАВ MASTER'S THESIS COLD PIPES ROLLING TITANIUM ALLOY SEAMLESS PIPE BILLET COLD ROLLING MILL
15	A study of promotion and attrition of mid-grade officers in the U.S. Marine Corps: are assignments a key factor? Morgan, Jerry R. 03 1900 (has links) Approved for public release, distribution is unlimited / This study analyzes the relationship between selection to major in the Marine Corps, and the survival of midgrade officers to the promotion point of major, by investigating the effects of billet assignments. Specifically, this study looks at the influence of the percentage of time spent in the Fleet Marine Forces (FMF), the percentage of time spent in primary military occupation (PMOS) billet assignments, and the effect of having served in combat, recruiting, security forces, joint, and drill field duties. Models were formulated using groundwork established in previous promotion, retention, and attrition studies. Assignment variables were then introduced to the models. To account for officers' choice for continued service vice forced attrition, the sample was restricted to officers who had attained five years of service. Probit regression was used to find the influence of career assignments on the probability of selection; Heckman's correction was used to control for self-selection bias; and, Cox proportionalhazard regression was used, utilizing the same assignment factors, to find the influence of assignments on the likelihood of attrition. The findings indicated that FMF and PMOS ratios above 60 percent had a negative effect on promotion and retention. Also indicated was that time spent outside the PMOS, in "B" billets, had a positive effect on retention. In a time of budgetary constraints, this information may provide assistance to personnel planners as an alternative to pecuniary measures used to maintain and shape the force. / Major, United States Marine Corps Regression analysis Attrition Billet assignments "B" billets Cox regressioin Fleet marine force duty Probit regression Manpower Officer retention Officer promotion Operational time Proportional hazards Retention Survival analysis
16	Les promesses de payer : essai de théorie générale / Promises to pay : essay of a general theory Stanczak, Romain 03 November 2015 (has links) Les promesses de payer sont des contrats par lesquels une personne s’engage envers un créancier à payer ce qui lui est dû. De tels actes sont courants ; leurs applications sont variées. Le cautionnement, l’acceptation d’une lettre de change, la promesse d’exécuter une obligation naturelle, l’engagement du délégué envers le délégataire, le constitut, la garantie autonome, la souscription d’un billet à ordre, etc., sont des promesses de payer. Plus précisément, ces actes sont des applications diverses d’une même figure juridique : la promesse de payer. Cette dernière, déshabillée des particularités propres à chacune de ses applications spéciales, se présente comme une figure juridique unitaire, pourvue d’une nature et de caractères permanents. Ayant pour objet un paiement, elle suppose toujours l’existence d’une dette à acquitter. Cette dette, ou « obligation principale », constitue sa cause objective. Contrairement à une simple reconnaissance de dette, la promesse ne se borne pas à déclarer l’existence de celle-ci. En tant qu’engagement d’exécution, elle donne naissance à une nouvelle obligation, l’ « obligation de règlement », venant s’adjoindre à la première en vue de son paiement. L’obligation de règlement, à ce titre, constitue l’accessoire de l’obligation principale. Son régime, de sa naissance à son extinction, sera donc plus ou moins lié à celui de cette dernière. / Promises to pay are contracts by which a person commits to pay to a creditor what is owed to him. Such acts are as common as they are various. For instance, bond, acceptance of a bill of exchange, promise to perform a natural obligation, commitment of the delegate to the delegatee, autonomous guarantee, subscription of a promissory note, etc. are promises to pay. In fact, such acts are different applications of a single legal figure : the promise to pay. Apart from the specificities of each of its applications, the promise to pay reveals itself as a uniform legal act with a permanent nature. Because its subject consists in a payment, the promise to pay always presupposes the existence of a debt. Such debt, or “primary obligation”, is the “objective cause” of the promise. Unlike a simple “IOU”, a promise to pay is not limited to declare the existence of the primary obligation. As a commitment, it also produces a new obligation, the “obligation to pay”, which coexists with the primary obligation. The obligation to pay, as such, is ancillary to the primary obligation. Its legal status, from its birth to its expiration, will be closely linked to that of the primary obligation. Promesse Paiement Pacte constitutae pecuniae Accessoire Reconnaissance de dette Cautionnement Constitut Garantie autonome Obligation de règlement Obligation principale Obligation naturelle Délégation Lettre de change Chèque Billet à ordre Crédit documentaire Codébiteur solidaire Sûretés Promise Payment Pactum constitutae pecuniae Accessory “IOU” Bond Natural obligation First demand guarantee Obligation to pay Primary obligation Delegation Bill of exchange Promissory note Irrevocable documentary credit Joint and several debtor Securities 346

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