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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.
1

Language contact and structural change an old Finnish case study /

Smit, Merlijn de. January 2007 (has links)
Proefschrift Stockholm University.
2

A kinesiological evaluation of diving fin design and performance

Yee, Michael Townsend. January 1991 (has links)
Thesis (M.S.)--University of California, Los Angeles, 1991. / Typescript (photocopy). Includes bibliographical references.
3

Die sog. hornfäden und die flossenstrahlen der fische ...

Brohl, Engelbert, January 1909 (has links)
Inaug.-diss.--Jena. / Lebenslauf. "Abdruck aus der Jenaischen zeitschrift für naturwissenschaft. Bd. XLV, n.f. XXXVIII, heft 2. 1909." "Literaturverzeichnis": p. 32-34.
4

Élaboration de matériaux multicouches par « laminage cumulé contrôlé » / Elaboration of multilayers by controlled accumulative roll bonding

Anghelus, Adrian 07 December 2012 (has links)
Cette étude porte sur la faisabilité de l’élaboration de matériaux multicouches à grains ultrafins par un procédé original de métallurgie douce : le laminage cumulé contrôlé. Les multicouches à base d’aluminium sont renforcés par des alliages de compositions Al-Ni-Sm pris dans des états amorphe ou cristallisés. Cette combinaison à ce jour inédite est originale compte tenu de la différence marquée de comportement mécanique et de mécanisme de déformation des constituants. Les paramètres du procédé sont d’abord définis à partir de la caractérisation de la stabilité microstructurale des constituants et de leur comportement mécanique. Plusieurs types de traitement thermique et mécanique, ainsi que différents nombres de couches ont été testés afin d’optimiser la microstructure et par tant l’aptitude à la mise en forme. Les transformations de phases (recristallisation dynamique ou non de l’aluminium, changements de phases au sein des alliages Al-Ni-Sm…) ont été analysées par diffractométrie X, microscopies et calorimétrie différentielle. Parmi les principaux résultats, la cristallisation du verre métallique induite par déformation est démontrée. En relation avec la modification de propriétés mécaniques induite par le changement de microstructure des renforts, les multicouches élaborées à partir de renforts à l’état cristallin sont plus malléables que celles obtenues au moyen d’alliages à l’état amorphe. La différence est reliée à la fois à la morphologie des débris et à l’accommodation des déformations au niveau des interfaces matrice/renfort. Au stade actuel du travail, un multimatériau a été synthétisé à partir de 216 couches d’aluminium et de 180 feuilles de renfort à l’état cristallin. Ce matériau à grains ultrafins présente encore une distribution non uniforme de fragments de renforts. / This study of feasibility deals with the development of ultrafine grained (UFG) multilayers by an original process i.e. controlled accumulative roll bonding. Aluminium based multilayers are reinforced by Al-Ni-Sm alloys taken either in the amorphous or crystallized state. This association of materials is particularly interesting according to the significant difference of mechanical behavior and mechanism of deformation of both constituents. The definition of the process parameters arises from the study of both the stability and the mechanical behaviour of the constituents. Numerous thermal and mechanical treatments as well as various numbers of stacked layers have been considered in order to optimize the microstructure and therefore workability of the multilayers. The phase transformations (dynamical or static recrystallization of Al, crystallization of amorphous alloys…) have been investigated by X-ray diffractometry, various kinds of microscopy and differential scanning calorimetry. Among the main results, the crystallization of the metallic glass due to deformation has been proved. Due to the modification of the mechanical properties induced by the change of microstructure of the reinforcements, the multilayers bearing crystalline reinforcements are more deformable than those containing amorphous alloys. The difference is explained by the morphology of the fragments of reinforcements as well as by the accommodation of deformation at their interfaces. Finally, a multimaterial has been prepared from 216 Al layers and 180 layers of crystalline reinforcements. This UFG material presents a heterogeneous distribution of reinforcements.
5

The Effect of Fins on Vortex Shedding

Jebodhsingh, Damon 10 1900 (has links)
An experimental study in air has been performed to determine what effect fins have on the flow over circular cylinders. The tubes under investigation included one bare tube and three segmented-finned tubes of different fin densities with the same root diameter as the bare tube. The tests were performed at two Reynolds numbers (2.61 x 104 and 4.98 x 104) and two downstream distances (2.5 & 5 diameters) and involved the use of hotwire anemometry. Measurements of mean and fluctuating velocities were taken across the wake as well as two-point fluctuating velocity correlations. It was discovered that the use of fins can result in significant differences. Fins cause larger mean velocity deficits in the wake profiles and significant shape differences in the total turbulence intensity profiles. Fins also increase the strength of vortex shedding, contrary to what would be expected, and increase the number of harmonic frequency peaks in the frequency spectra as three harmonic peaks were observed for the bare tube, while as many as ten were seen for the densest finned tube. Correlation length measurements, and thus radiated sound intensity, proved to be inconclusive. It was discovered that correlation length changed with angular rotation suggesting that this phenomenon needs to be investigated further before making any comparisons. Based on the differences seen with increased fin density, it is thought that there may be a critical fin density which causes fundamental changes in the cylinder wake. Also, during the course of this investigation, it was concluded that while the use of an effective diameter, De, proved adequate in collapsing the finned tube data, this approximation could be improved. / Thesis / Master of Applied Science (MASc)
6

The Effect of Fins on Vortex Shedding

Jebodhsingh, Damon 10 1900 (has links)
An experimental study in air has been performed to determine what effect fins have on the flow over circular cylinders. The tubes under investigation included one bare tube and three segmented-finned tubes of different fin densities with the same root diameter as the bare tube. The tests were performed at two Reynolds numbers (2.61 x 104 and 4.98 x 104) and two downstream distances (2.5 & 5 diameters) and involved the use of hotwire anemometry. Measurements of mean and fluctuating velocities were taken across the wake as well as two-point fluctuating velocity correlations. It was discovered that the use of fins can result in significant differences. Fins cause larger mean velocity deficits in the wake profiles and significant shape differences in the total turbulence intensity profiles. Fins also increase the strength of vortex shedding, contrary to what would be expected, and increase the number of harmonic frequency peaks in the frequency spectra as three harmonic peaks were observed for the bare tube, while as many as ten were seen for the densest finned tube. Correlation length measurements, and thus radiated sound intensity, proved to be inconclusive. It was discovered that correlation length changed with angular rotation suggesting that this phenomenon needs to be investigated further before making any comparisons. Based on the differences seen with increased fin density, it is thought that there may be a critical fin density which causes fundamental changes in the cylinder wake. Also, during the course of this investigation, it was concluded that while the use of an effective diameter, De, proved adequate in collapsing the finned tube data, this approximation could be improved. / Thesis / Master of Applied Science (MASc)
7

Evolution of modular morphology in actinopterygian pectoral fins

Tissandier, Sylvie. January 2006 (has links)
No description available.
8

Evolution of modular morphology in actinopterygian pectoral fins

Tissandier, Sylvie. January 2006 (has links)
With a generally conserved function for locomotion, paired fins have an extensive evolutionary history that has resulted in highly disparate morphologies in a wide diversity of taxa. Two-dimensional geometric morphometrics offers a means to quantitatively describe disparity and changes in the shape of pectoral fins. Actinopterygians lend themselves well to a study of this nature due to their prolific diversity and prevalence in the fossil record. As a result of changes in skeletal fin structures and the lack of homologous elements throughout the group, three morphological modules are used as the unit of comparison rather than individual elements of the fin. Ordination plots from thin plate spline analyses, including fossil and extant taxa, show correspondence with the actinopterygian phylogeny as trends become apparent through the group. Basal actinopterygians and basal teleosts tend to have a narrow, elongate fin shape. Following a shift in morphospace, derived teleosts have a wider fin base, with an elongate anterior margin of the fin relative to the posterior trailing edge. Linear and squared-change parsimony reconstructions of continuous data allow the phylogeny to be traced through morphospace to approximate the path of pectoral fin evolution. The shift in morphospace occurs at Acanthomorpha, and is correlated with the evolution of a physoclistous swim bladder and a change in the position and orientation of pectoral fins. As a result of these changes, new swimming modes are made available, and the expansion of locomotory modes of Acanthomorpha is here hypothesized to be associated with a sharp increase in pectoral fin disparity.
9

Organizações do terceiro setor : uma abordagem comparativa de critérios contábeis de reconhecimento, mensuração e evidenciação brasileiros, estadunidenses e internacionais

Rochael, Denise 14 October 2009 (has links)
Dissertação (mestrado)-Universidade de Brasília, Departamento de Ciências Contábeis, Programa de Pós-Graduação em Ciências Contábeis, 2009. / Submitted by Jaqueline Ferreira de Souza (jaquefs.braz@gmail.com) on 2011-05-12T00:32:44Z No. of bitstreams: 1 2009_DeniseRochael.pdf: 975985 bytes, checksum: d51c72cd18efc9d16cb44eb29e125ac9 (MD5) / Approved for entry into archive by Jaqueline Ferreira de Souza(jaquefs.braz@gmail.com) on 2011-05-12T00:34:10Z (GMT) No. of bitstreams: 1 2009_DeniseRochael.pdf: 975985 bytes, checksum: d51c72cd18efc9d16cb44eb29e125ac9 (MD5) / Made available in DSpace on 2011-05-12T00:34:10Z (GMT). No. of bitstreams: 1 2009_DeniseRochael.pdf: 975985 bytes, checksum: d51c72cd18efc9d16cb44eb29e125ac9 (MD5) / A expansão do terceiro setor em quantidade de recursos movimentados e em número de organizações é acompanhada da exposição destas entidades a verificações sobre a gestão dos recursos que movimenta e possui em seu patrimônio. Um dos meios de significativa utilidade para prestar contas, pela riqueza de informações que possui, são as demonstrações financeiras, cuja estruturação e apresentação são fundamentadas em normas contábeis. As normas internacionais representam o parâmetro normativo atual de adoção por entidades que escolhem ou são sujeitas a seguirem a linguagem contábil internacional. As normas estadunidenses são referência de qualidade e profundidade nos critérios apresentados por seus pronunciamentos, inclusive os aplicáveis ao terceiro setor. O recebimento de recursos externos por entidades brasileiras deste setor está sujeito a avaliação da infraestrutura destas entidades e de sua capacidade e histórico em aplicá-los de acordo com o propósito designado. Suas demonstrações financeiras devem ser elaboradas nas melhores práticas contábeis para serem adequadamente interpretadas pelos usuários. Esta pesquisa contribui com os usuários das demonstrações por apresentar a comparação dos critérios contábeis brasileiros com os internacionais e estadunidenses para sete itens característicos do terceiro setor, além de pôr em confronto a base conceitual usada por estes conjuntos normativos e as demonstrações financeiras por eles exigidas. O objetivo da pesquisa – avaliar em que nível os critérios brasileiros de reconhecimento, mensuração e evidenciação contábeis de entidades do terceiro setor estão aderentes aos padrões contábeis internacionais e estadunidenses – foi atingido por meio do confronto sistemático de normas e guias de procedimento emitidos nas três esferas, separando para cada item pré-estabelecido as abordagens relativas a seu reconhecimento, mensuração e evidenciação. O conjunto normativo estadunidense é o que apresenta maior diferenciação por mostrar extensivamente em suas normas que reconhece a relevância das particularidades do setor não lucrativo, criando alternativas de contabilização para apresentar suas operações com uma visão mais próxima às suas necessidades de evidenciação, tais como a segregação do patrimônio das entidades entre permanentemente restrito, temporariamente restrito e irrestrito. As normas brasileiras, nos aspectos referentes ao terceiro setor, não avançam muito além de determinar diferenciações de nomenclaturas, citar as demonstrações financeiras cuja apresentação é necessária por estas entidades e tratar de gratuidades e receitas características do setor, e precisam ser trabalhadas em alguns aspectos para reduzir o número de inconsistências em suas orientações. As normas internacionais foram elaboradas com o objetivo maior de atender às necessidades dos usuários de demonstrações do setor privado, tendo poucas orientações a eventos típicos do terceiro setor. O pronunciamento mais próximo das rotinas das entidades sem fins lucrativos é a norma sobre assistências e subvenções. _________________________________________________________________________________ ABSTRACT / The expansion of the third sector, in amount of managed resources and in number of organizations, is followed by the exposure such entities to fiscal control of the management skills of its resources and patrimony. One of the most useful ways of meeting external reporting obligations is the use of financial statements which have their structure and presentation based on accounting standards, due to the variety of information they supply. The international financial reporting standards represent the current regulatory parameter adopted by entities that either choose to, or are subjected to, complying with international accounting language. The United States Generally Accepted Accounting Principles are an important reference of quality of criteria presented by its pronouncements, including those applicable to the third sector. Foreign credit and resources sent to Brazilian non-profit organizations subject such institutions to the fiscal control and examination of its infrastructure, history and capacity of applying the received resources to the designated purposes. Their financial statements should be prepared using the best available accounting tools with the purpose of having them properly analyzed by the end users. This research contributes to the users of financial statements by presenting a comparison between the Brazilian, the international and the American (United States) accounting standards on seven specific items of the third sector, and also by confronting the conceptual basis used by these set of rules and financial statements required by them. The purpose of the research – to analyze in which level the Brazilian third sector accounting criteria of identification, measurement and disclosure is in accordance with the International Financial Reporting Standards and the United States Generally Accepted Accounting Principles – has been achieved through the systematic comparison of the rules and procedural guidelines set up by the three frameworks, separating each pre-established item on the analysis related to its recognition, measurement and disclosure. The United States Generally Accepted Accounting Principles is the framework that most differs from the others, for extensively showing in its standards that it recognizes the relevance and particularities of the nonprofit sector. Accounting alternatives were established for non-profit organizations to disclosure their operations with a closer look at their user requirements, such as segregation of net assets in permanently restricted, temporarily restricted and unrestricted. In aspects referring to the third sector, the Brazilian accounting standards do not really go beyond determining nomenclature differentiation, naming the financial standards that are required to be disclosed by such entities, and exploring the specifics of this sector’s revenue. The Brazilian standards should be improved in some aspects in order to reduce the number of inconsistencies in their guidelines. The International Financial Reporting Standards were created to meet the needs of the users of financial statements on the private sector, with very little orientation for typical events of the third sector. The standard that has closer application to the routines of non-profit organizations is the one for government grants and assistance.
10

Trailing edge strips to reduce the drag of slender wings

Bruce, R. J. January 1988 (has links)
No description available.

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