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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
31

Physics and engineering of sheet plasma devices / シートプラズマ装置の物理と工学 / シート プラズマ ソウチ ノ ブツリ ト コウガク

Arnold Rey Burgos Gines 20 September 2019 (has links)
また、この研究は、特定の動作条件で生成されたシートプラズマで、プラズマやシートプラズマの寸法を決定する動作パラメータなどのプラズマ条件を理解し、最適化パラメータと将来の産業用アプリケーションの条件を導き出すことも目的としています。 そのため、この研究は、表面技術アプリケーション用のシートプラズマデバイスの開発と理解に貢献することを試みています。 / Sheet plasmas have the advantage of producing thin films and functional surfaces by generating localized high-density and temperature gradient regions suitable for specific reactions. A stream of high energy electrons from a plasma cathode efficiently excites and/or ionizes atomic and molecular species which are confined in a linear magnetic field. An electron cyclotron resonance (ECR) sheet plasma device employing a 2.45 GHz microwave source and combination of permanent magnets and field coils was designed and operated. The combined field realized a linear magnetic field that sustained a rectilinear confinement of the plasma. / 博士(工学) / Doctor of Philosophy in Engineering / 同志社大学 / Doshisha University
32

Effect of Wall Penetration Depth on the Behavior of Sheet Pile Walls

Amer, Hetham A. Ramadan 23 May 2013 (has links)
No description available.
33

Correlation of the elastic and plastic anisotropy of rolled FCC and BCC sheet

Makarow, Irina January 1987 (has links)
No description available.
34

Prepainted galvanized steel sheet and color steel sheet in steel industry compete advantage to study-- Case Yiehphui Company Study

Wang, Chih-chiang 10 August 2005 (has links)
Along with science and technology gradually make progress, there is no distance between country. WTO world commerce cloggy eliminate, have no frontier's confine to make product and service that almost be obvious everywhere in the world. Under economic liberalization and internationalize affection, make enterprise management no longer confine to one area or single country. Economic globalization impact everywhere in the world. Iron and steel industry can¡¦t also avoid meeting severely impact and change. In 2002, because global economies gradually change better, lead to international steel market demand to grow up quickly. It is fourth season to reach the best. Price appears take on upspring, too. Due to every important manufacturer rob to buy materical each other in the world, appear steel materical demand to exceed supply. At the end of the year 2003, America, European union, mainland China cancel import restriction successively. At the beginning of the year 2004, price of freight, iron ore, coalmine, scrap steel (Steel ingredient) increases largely at the same time. Many countries ensure steel requirement materials at home, so steel importation tariff transfer fall successively. It makes strict confine measure gradually change to loose. Hot Rolled Galvanized Steel Sheet requires mean consumption to grows up 4.4% near five years in the world. Price also rise along with the price of Hot-Rolled Steel Coil is on raise at the same time. Steel market changes quickly like electronic product¡¦s life. Steel industry face structure change and reform management. In the world, all steel industry is toward competition and cooperative style. Industry internationalize brings manufacture and sales mode's changed. Industry protection policy already do not exist. With environment changed quickly, enterprise do the best increase management performance. It just be able to abidingly run and develop. The study chiefly use questionaire as interview style to get information and organize theoretical document to review and research. Let us know Hot Rolled Galvanized Steel Sheet and Prepainted Hot-Dip Zinc Coated Steel Sheet company how to develop in the world now. It is as Yiehphui company for example, explore Hot Rolled Galvanized Steel Sheet and Prepainted Hot-Dip Zinc Coated Steel Sheet industry how to take advantage of limited source and face industry environmental change to upgrade management technique. By industry internationalization working principles, make enterprise management risk asunders and create industry competition advantage. It becomes industry developmental reference. The study shows some conclusions as follows: 1. Materials source need stability and multiplication. It avoid confining provider but have no method to acquire advantaged negotiate. 2. International steel area integrated tendency have already formed. Major company become bigger and bigger can not avoid. Individual company should cooperation or tactic federation at home with same industry company, form area economy magnitude and debases competition pressure. 3. Push and import TPM management system and TSM work safe management system to healthy company operate constitution and attract elitist. 4. Global market runs for springboard as strengthen developmental technology, develop high affixation value product and new product use domain. It aggravates brand impression and difference product to used for seize more market area and market benefit.
35

Modeling and management of process-induced shape distortion of sheet metal products /

Ye, Tai-Kun, January 2001 (has links)
Thesis (Ph. D.)--University of Missouri-Columbia, 2001. / Typescript. Vita. Includes bibliographical references (leaves 162-168). Also available on the Internet.
36

Modeling and management of process-induced shape distortion of sheet metal products

Ye, Tai-Kun, January 2001 (has links)
Thesis (Ph. D.)--University of Missouri-Columbia, 2001. / Typescript. Vita. Includes bibliographical references (leaves 162-168). Also available on the Internet.
37

Vrillage de tôles métalliques ultra-minces après emboutissage / Twisting analysis of ultra-thin metallic sheets after deep-drawing

Pham, Cong Hanh 19 December 2014 (has links)
Le vrillage est un mode de retour élastique particulier, qui se produit suite à la mise en forme par emboutissage de pièces allongées, à savoir dont une des dimensions est grande devant les deux autres. Le vrillage est caractérisé par la torsion de la pièce autour d’un axe parallèle à la plus grande dimension. D’un point de vue expérimental, le vrillage représente un véritable défi, du fait de la grande dimension, de l’ordre du mètre, des pièces industrielles et de la grande dispersion des valeurs caractéristiques de vrillage obtenues pour un même procédé et un même matériau. En conséquence, l’étude du vrillage en utilisant une échelle réduite sur l’ensemble des dimensions outils et pièce est retenue pour ce travail de thèse, avec un intérêt particulier pour l’influence de l’alignement tôle/outils sur l’intensité du vrillage.L’objectif général de ce travail de thèse est l’étude expérimentale et numérique du vrillage de pièces en forme de U, à partir de flans de longueur 100 mm et d’épaisseur 0,15 mm. Une première partie concerne la caractérisation et modélisation du comportement mécanique du matériau, un acier inoxydable. Des essais mécaniques de traction et cisaillement simple ont été réalisés, avec une mesure locale sans contact du champ de déformation. L’écrouissage ainsi que l’évolution de la pente à la décharge ont été caractérisés, et les paramètres d’un modèle élasto-plastique avec écrouissage mixte et dépendance du module d’Young avec la déformation plastique équivalente ont été identifiés à partir de ces essais.Afin de constituer une base expérimentale sur le vrillage, un dispositif spécifique a été conçu et usiné dans le cadre de cette thèse. Des essais d’emboutissage de flans rectangulaires, de dimensions 100 x 28 mm2, pour atteindre une forme de U de profondeur 7 mm, ont été réalisés. L’alignement de l’éprouvette avec le poinçon et la matrice a été particulièrement contrôlé et deux orientations ont été étudiées : l’éprouvette est soit alignée avec le poinçon, soit désalignée de 2° par rapport à son centre. La forme finale des éprouvettes a été mesurée avec un scanner laser. Le vrillage est caractérisé par le rapport de l’angle entre le fond de deux sections extrêmes sur leur distance respective. Un vrillage de 11°.m-1 a été mesuré pour les éprouvettes désalignées, tandis que pour les éprouvettes alignées, aucun vrillage significatif n’a été obtenu. L’étude des sections transversales de l’éprouvette montre une corrélation entre l’asymétrie du retour élastique causée par l’asymétrie de la géométrie de l’éprouvette, dans le cas désaligné, et le vrillage. Le glissement de l’éprouvette sous le poinçon au cours de l’essai affecte également le vrillage quelque soit l’orientation de l’éprouvette.Finalement, la simulation numérique de la mise en forme d’un flan en forme de U a été effectuée avec le code de calcul Abaqus®. Un solveur explicite est utilisé pour l’étape d’emboutissage et un solveur implicite pour le retour élastique. L’influence de la taille de maillage, ainsi que celle de la loi de comportement du matériau ont été étudiées. Les résultats de la simulation numérique sont alors confrontés aux résultats expérimentaux. / Twisting of metallic sheets is one particular mode of springback that occurs after drawing of elongated parts, i.e. with one dimension much larger than the two others. Twisting is usually characterized by the disorientation angle between the two end sections which turn around an axis parallel to the greatest dimension. From experimental point of view, twisting is very challenging because a lot of data were obtained on industrial-type parts, with one dimension of the order of the meter. These data are usually very dispersed and with the same process parameters, material and geometry, very different values for the twisting parameter can be obtained. As a consequence, the study of twisting phenomenon by using a reduced scale for all the dimensions of the tools and blank is retained in this work of. The influence of the blank alignment with the tools on the intensity of the twisting parameter was particular investigated.The objective of the thesis is the experimental and numerical study of the twisting of U-shaped part, obtained from stainless steel blanks with a length of 100 mm and thickness of 0.15 mm. The first part relates to the characterization and modeling of the material mechanical behavior. Conventional tests such as tension and simple shear were performed. The kinematic contribution to the hardening and the evolution of the loading-unloading slope with the plastic deformation were carried out. The parameters of an elastic-plastic model based on a mixed hardening and degradation of Young’s modulus with the equivalent plastic strain have been identified from these tests.In order to establish an experimental database for twisting, a dedicated device for drawing U-shaped elongated parts was designed and manufactured. Deep-drawing of rectangular blanks, of dimensions 100 x 28 mm2, to achieve a U-shape rail of 7 mm of depth was performed. Two different orientations of the part with respect to the tools were chosen: either aligned with the tools, or purposefully misaligned by 2°. The geometry of the part after springback was laser scanned. Twisting is characterized by the disorientation angle in-between the two end sections of the part over the distance. Several samples were drawn for each configuration, leading to the conclusion that almost no twisting occurs in the first case whereas a twisting parameter of 11°.m-1 corresponded to the second one. The analysis of the geometry of cross sections has shown a correlation between twisting and asymmetry of springback, like the opening of the U-shaped rail, caused by the asymmetry of the blank in the misaligned case. The sliding of the blank beneath the punch during the process also affects twisting whatever its orientation. Finally, finite element simulation of the drawing process, for the two configurations of the blank, within the explicit framework for drawing and implicit one for springback, were carried out using Abaqus® software. The influences of the mesh size as well as the material behavior law on the intensity of twisting parameter were studied. Numerical predictions were compared with experiments.
38

Arabic 1620: An Analysis and Procedure for Composing Computer Music VOL. 2

Lott, William Loyd 08 1900 (has links)
Computers are used in the music field for generation of sound, for composing music, for analysis of music, and for musicological applications, such as cataloguing a bibliography of music literature. These areas are relatively new aspects of computer usage, and research is being conducted to stay abreast of current technological advancements. Avant-garde composers are challenged by new advances in music. Computer-generated music is one of the new trends, but the composer is usually limited in the use of the medium for two reasons: there are no computers to which he may have access, and/or there is not enough knowledge about computer-generated music. The composer sometimes feels that he must have vast knowledge of the computer before he can attempt to use it in musical composition; however, a limited amount of investigation of computer-generated music has shown that methods can be codified to the point where great technical knowledge is not required of the composer.
39

Process Simulation of Roll Forming and Roll Pass Design

Duggal, Nitin January 1995 (has links)
No description available.
40

Changing Depositional Environments in the Marginal Zone of a High Latitude Ice Sheet

Miller, Raoul 08 1900 (has links)
This thesis is missing page 28 from this and all other copies. -Digitization Centre / Glacial and glacially-influenced deposits examined at two sites in west-central Ellesmere Island provide insights into the nature of glaciation during the late-Wisconsinan and Holocene advances, and the modes of deposition from arid, high latitude ice bodies. Glacial lithofacies identified indicate that englacial debris content varied spatially and it is inferred that basal thermal conditions also exhibited a complex pattern. Direct glacial deposits usually consist of unsorted diamicts with a complete size range of matrix components, indicating an absence of meltwater-sorting or winnowing during deposition. Glacially-influenced fluvial, lacustrine, and nearshore marine deposits show that most of the Quaternary sediments were deposited by low-frequency, high magnitude events during deglaciation. A tentative reconstruction of late-glacial history in the Strathcona Fiord area proposes that an ice tongue surged down Strathcona Fiord from a previous maximum position coincident with the present day head of the fiord. This surge destabilised the margin locally, causing rapid collapse in the valleys and melting into ice-cored basins on the higher plateau areas. Periodically these ice-cored basins would drain, providing large water and sediment discharges and reworking in some sites whilst leaving other deposits unaffected. Subsequent reworking has been minimal in the cold, arid environment where continued uplift favours fluvial incision rather than extensive sandur development. Examination of the modern ice margin shows that the ice here is frozen to the substrate but basal debris bands indicate that at some localities basal temperatures must be above pressure melting point. Patterns of debris entrainment and deposition and debris lithologies suggest that much of the transported debris is incorporated where lobes of ice begin to flow out from the main ice cap. / Thesis / Master of Science (MS)

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