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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.
41

A plastic-based thick-film li-ion microbattery for autonomous microsensors /

Lin, Qian, January 2006 (has links) (PDF)
Thesis (Ph. D.)--Brigham Young University Dept. of Chemical Engineering, 2006. / Includes bibliographical references (p. 155-165).
42

Food resource use and responses to changes in prey availability of common and thick-billed murres (Uria aalgae and U. lomvia) breeding at the Gannet Islands, Labrador /

Bryant, Rachel L., January 1998 (has links)
Thesis (M. Sc.), Memorial University of Newfoundland, 1998. / Bibliography: leaves 110-121.
43

Processamento por infusão a vácuo de compósitos espessos aramida/epóxi e análise do desempenho sob impacto

Nunes, Stephanie Gonçalves January 2018 (has links)
Em aplicações que requerem solicitações de impacto, compósitos de matriz polimérica reforçados com fibra de aramida se destacam, principalmente em relação aos metais, devido a propriedades como alta resistência e rigidez específicas, que dão origem a sistemas mais leves e de alta performance. Quando voltados para aplicações de impacto, principalmente a alta velocidade, tais compósitos são, em sua maioria, moldados por compressão ou autoclave, a partir de pré-impregnados. No entanto, tais combinações de processamentos e matéria-prima acarretam em estruturas de elevado custo, tornando a infusão a vácuo uma opção atrativa, além de permitir a obtenção de peças grandes e complexas, dimensionalmente acuradas e partes integradas. Porém, a obtenção de um compósito espesso reforçado por fibra de aramida com elevado desempenho ao impacto por tal método de fabricação ainda é um desafio. Neste contexto, este trabalho aborda o efeito da espessura no processamento por infusão a vácuo de compósitos aramida/epóxi e seu desempenho em aplicações que requerem solicitações de impacto (baixa e alta velocidade) Para isso, foram produzidos compósitos com 5, 8, 13, 18, 23 e 28 camadas de aramida e caracterizados por ultrassom C-scan, microscopia ótica, densidade, teor de constituintes, testes mecânicos (flexão, short beam e indentação quase-estática) e cargas de impacto de baixa e alta velocidade (drop-weight e balístico). Todos os compósitos apresentaram boa homogeneidade na distribuição da matriz ao longo do reforço, com um teor de fibra de ≈60%, e valores de resistência short beam elevados (17,3 - 23,6 MPa). A performance sob impacto (baixa e alta velocidade) foi comparável à de compósitos fabricados por compressão ou autoclave, tendo os compósitos a partir de 18 camadas resistido ao projétil 9 mm Luger FMJ e o de 28 camadas resistido ao projétil .357 Magnum FMJ, podendo ser classificados como nível FB2 e FB3, respectivamente, de acordo com a norma europeia EN 1522. Portanto, o processamento de infusão a vácuo mostrou ser uma alternativa adequada para produzir compósitos espessos de aramida/epóxi (até 12 mm), substituindo rotas de processamento mais caras. / In applications that require impact solicitations, polymer matrix composites reinforced with aramid fiber stand out, especially in relation to metals, due to properties such as high specific strength and stiffness, which give rise to lighter and high-performance systems. When used for impact applications, especially at high speed, such composites are mostly molded by compression or autoclaved, from prepregs. However, such combinations of processing and raw material lead to high cost structures, making vacuum infusion an attractive option, as well as allowing the production of large, complex, dimensionally accurate and integrated parts. Nonetheless, obtaining a thick composite reinforced by aramid fiber with high impact performance by such manufacturing method is still a challenge. In this context, this work addresses the effect of the thickness in the vacuum infusion processing of aramid/epoxy composites and its performance in applications that require impact solicitations (low and high speed) For this, composites with 5, 8, 13, 18, 23 and 28 layers of aramid were produced and characterized by ultrasonic C-scan, optical microscopy, density, constituent content, mechanical tests (flexion, short beam and quasi-static indentation) and low- and high-speed impact loads (drop-weight and ballistic). All composites presented good homogeneity in the matrix scattering along the reinforcement, with a fiber content of ≈ 60%, and high short beam resistance values (17.3 - 23.6 MPa). The performance under impact (low and high speed) was comparable to that of composites processed by compression or autoclave, the composites with 18 layers resisted to the 9 mm Luger FMJ projectile and the one with 28 layers resisted to the .357 Magnum FMJ projectile, being classified as level FB2 and FB3, respectively, according to the European standard EN 1522. In summary, vacuum infusion processing proved to be a suitable alternative to produce thick aramid/epoxy composites (up to 12 mm), replacing more expensive processing routes.
44

Processamento por infusão a vácuo de compósitos espessos aramida/epóxi e análise do desempenho sob impacto

Nunes, Stephanie Gonçalves January 2018 (has links)
Em aplicações que requerem solicitações de impacto, compósitos de matriz polimérica reforçados com fibra de aramida se destacam, principalmente em relação aos metais, devido a propriedades como alta resistência e rigidez específicas, que dão origem a sistemas mais leves e de alta performance. Quando voltados para aplicações de impacto, principalmente a alta velocidade, tais compósitos são, em sua maioria, moldados por compressão ou autoclave, a partir de pré-impregnados. No entanto, tais combinações de processamentos e matéria-prima acarretam em estruturas de elevado custo, tornando a infusão a vácuo uma opção atrativa, além de permitir a obtenção de peças grandes e complexas, dimensionalmente acuradas e partes integradas. Porém, a obtenção de um compósito espesso reforçado por fibra de aramida com elevado desempenho ao impacto por tal método de fabricação ainda é um desafio. Neste contexto, este trabalho aborda o efeito da espessura no processamento por infusão a vácuo de compósitos aramida/epóxi e seu desempenho em aplicações que requerem solicitações de impacto (baixa e alta velocidade) Para isso, foram produzidos compósitos com 5, 8, 13, 18, 23 e 28 camadas de aramida e caracterizados por ultrassom C-scan, microscopia ótica, densidade, teor de constituintes, testes mecânicos (flexão, short beam e indentação quase-estática) e cargas de impacto de baixa e alta velocidade (drop-weight e balístico). Todos os compósitos apresentaram boa homogeneidade na distribuição da matriz ao longo do reforço, com um teor de fibra de ≈60%, e valores de resistência short beam elevados (17,3 - 23,6 MPa). A performance sob impacto (baixa e alta velocidade) foi comparável à de compósitos fabricados por compressão ou autoclave, tendo os compósitos a partir de 18 camadas resistido ao projétil 9 mm Luger FMJ e o de 28 camadas resistido ao projétil .357 Magnum FMJ, podendo ser classificados como nível FB2 e FB3, respectivamente, de acordo com a norma europeia EN 1522. Portanto, o processamento de infusão a vácuo mostrou ser uma alternativa adequada para produzir compósitos espessos de aramida/epóxi (até 12 mm), substituindo rotas de processamento mais caras. / In applications that require impact solicitations, polymer matrix composites reinforced with aramid fiber stand out, especially in relation to metals, due to properties such as high specific strength and stiffness, which give rise to lighter and high-performance systems. When used for impact applications, especially at high speed, such composites are mostly molded by compression or autoclaved, from prepregs. However, such combinations of processing and raw material lead to high cost structures, making vacuum infusion an attractive option, as well as allowing the production of large, complex, dimensionally accurate and integrated parts. Nonetheless, obtaining a thick composite reinforced by aramid fiber with high impact performance by such manufacturing method is still a challenge. In this context, this work addresses the effect of the thickness in the vacuum infusion processing of aramid/epoxy composites and its performance in applications that require impact solicitations (low and high speed) For this, composites with 5, 8, 13, 18, 23 and 28 layers of aramid were produced and characterized by ultrasonic C-scan, optical microscopy, density, constituent content, mechanical tests (flexion, short beam and quasi-static indentation) and low- and high-speed impact loads (drop-weight and ballistic). All composites presented good homogeneity in the matrix scattering along the reinforcement, with a fiber content of ≈ 60%, and high short beam resistance values (17.3 - 23.6 MPa). The performance under impact (low and high speed) was comparable to that of composites processed by compression or autoclave, the composites with 18 layers resisted to the 9 mm Luger FMJ projectile and the one with 28 layers resisted to the .357 Magnum FMJ projectile, being classified as level FB2 and FB3, respectively, according to the European standard EN 1522. In summary, vacuum infusion processing proved to be a suitable alternative to produce thick aramid/epoxy composites (up to 12 mm), replacing more expensive processing routes.
45

Caracterização eletroquímica e ótica de filmes de óxido espesso crescidos sobre ouro. / Eletrochemical and optical characterization of thick oxide films on gold electrodes.

Luiz Henrique Dall\'Antonia 26 April 1995 (has links)
Através de polarização potenciostática de eletrodos de ouro policristalino em vários potenciais de polarização, 1,8,...., 2,4 V, ERH, por tempos de ate 72 h, em meios ácido e alcalino, conduz a formação de quatro estados do Óxido, OC1, OC2, OC3 e OC4, distinguíveis, durante o processo de redução pela técnica de voltametria cíclica. O estado quase-bidimensional (OC1) tende a um limite de duas monocamadas, em meio ácido, e penas uma em meio básico, de AuOads, enquanto, o filme espesso (OC2, OC3 e OC4, Au2O3) não atinge qualquer limite de crescimento. Os diagramas de carga catódica total (que mede o crescimento do filme de Óxido) vs log tempo de polarização revelam duas regiões lineares: (a) lenta, abaixa de 1 mC cm-2, (b) rápida, acima de 1 mC cm-2. Este comportamento é atribuído a um novo mecanismo de crescimento do óxido. Durante o crescimento do filme de óxido em altos potenciais anódicos, passando pelo vários estágios identificáveis por voltametria cíclica, pequenas mas significantes mudanças ocorrem na cinética de geração de O2. Os diagramas de Tafel revelam duas regiões lineares para a reação de geração de oxigênio, R.G.O., em meios ácido e alcalino. O mecanismo da R.G.O. é preliminarmente discutido. Finalmente, estudos dos filmes espesso de óxido de ouro foram realizados in situ por elipsometria espectroscópica. Os espectros do filme de óxido na faixa de comprimento de onda entre 300 e 800 nm, nos vários estágios de crescimento foram obtidos. Está mostrado que, ambos, a espessura do filme e o espectro ótico podem ser calculados em cada estágio durante o crescimento do óxido assumindo a existência de um filme fino altamente absorvente, adjacente à superfície do metal, e no topo deste um segundo filme que se assemelha mais a uma forma hidratada do \"Au2O3\". Este último filme atinge espessuras da ordem de várias centenas de A, quando polarizado por até 72 h. / Potentiostatic polarization of polycrystalline Au electrodes at various polarization potentials, 1.8, ..., 2.4 V, RHE, for polarization times up to 72h, in acid and basic solutions, leads to formation of four oxide states, OC1, OC2, OC3 and OC4, distinguished, in reduction, using linear-sweep voltammetry. The quasi-2d state (OC1) tends to the limit of two monolayers in acid solution and one monolayer in basic solution of AuOads, while the quasi-3d state (OC2-OC4, Au2O3) does not reach any limit in its extent. The cathodic total charge log polarization time plots reveal two linear regions: (a) slow, up to 1 mC cm-2, and (b) fast, beyond 1 mC cm-2. This behavior is attributed to a new oxide growth mechanism. During growth of the oxide film at high anodic potentials through the various stages identifiable in cyclic voltammetry, small but significant changes in the kinetics of O2, evolution arise. Tafel slopes for the oxygen evolution reaction, OER, reveal two linear region in acid and alkaline medium. The mechanism of the OER is preliminarily discussed. Finally, studies of the thick anodic oxide films on Au is done in situ by spectroscopic ellipsometry. The spectrum of the oxide film in the wavelength range 300 to 800 nm, at various stages of film growth is obtained. It is shown that both film thickness and optical spectrum can be solved at each stage in oxide growth assuming a highly absorbing thin film adjacent to the metal surface, and, on the top of it, a second film, which is most probably a hydrous form of \"Au2O3\". The latter film reaches thicknesses of severa1 hundreds A&#177 up to 72h of anodization.
46

Deposição de nanopartículas de Ba(Ti0.85Zr0.15)O3 pela técnica de eletroforese para fabricação de filmes espessos ferroelétricos sinterizados a laser / Electrophoretic deposition of Ba(Ti0.85Zr0.15)O3 nanoparticles to fabrication of laser sintered ferroelectrics thick films

Eduardo Antonelli 28 November 2008 (has links)
Os objetivos deste trabalho foram a implantação e a otimização da técnica de sinterização por varredura a laser de filmes espessos, o estudo da cinética do processo e a avaliação das propriedades do composto BaTi0.85Zr0.15O3 (BTZ) sinterizado a laser, em comparação com os filmes sinterizados em forno. Pós nanocristalinos de BTZ foram sintetizados em baixas temperaturas com sucesso pela primeira vez (600ºC), por meio do método dos precursores poliméricos modificado. Foram obtidos pós nanométricos com tamanho de partículas primárias de ~20 nm e com aglomeração controlada, uma inovação para pós de BTZ preparados por rotas químicas. Para a deposição dos filmes, a estabilidade das suspensões de partida foi estudada e filmes espessos com excelente homogeneidade foram depositados utilizando a técnica de eletroforese (EDP). O desenvolvimento da técnica permitiu o controle da espessura do filme a partir dos parâmetros de deposição. A montagem experimental para a sinterização a laser foi otimizada de modo a permitir a sinterização de filmes com dimensões de até 70 mm de comprimento por 10 mm de largura e espessuras variáveis. Os tempos de patamares em cada etapa foram dependentes da velocidade e do número de varreduras. A temperatura máxima que se pode atingir no filme espesso, durante cada varredura e para uma potência nominal do laser fixa, foi correlacionada com a densidade relativa. Os processos térmicos envolvidos durante a varredura a laser atuaram de modo similar á sinterização em duas etapas (two step sintering). Com o intuito de melhorar a densificação dos filmes, passamos a adicionar o composto Bi4Ti3O12 (BIT) (1 e 2 mol %) ao BTZ durante a deposição. A utilização do sistema desenvolvido para a sinterização por varredura a laser em conjunto com o acréscimo do aditivo BIT resultou em uma diminuição no tamanho de grão dos filmes e uma importante diminuição da porosidade aparente. Para a aditivação com 2 mol% de BIT obtivemos filmes de ótima densidade (porosidade aparente de ~4%) e reduzido tamanho de grão (~200 nm), resultado inédito em se tratando de filmes espessos. A sinterização a laser resultou em filmes com maior permissividade dielétrica em relação ao filme sinterizado em forno elétrico. As reações que ocorrem entre o BTZ e o BIT foram exploradas usando conjuntamente as técnicas de espectroscopia de impedância, análise térmica e difratometria de raios-X. / The goals of this work were the implantation and optimization of the technique of sintering by laser scan of thick films, the kinetic study of the process and the evaluation of the physical properties of the laser sintered compound BaTi0.85Zr0.15O3 (BTZ), compared to thick films sintered in conventional furnace. Nanocrystalline powders of BTZ were for the first time, successfully synthesized at low temperatures (600ºC) using the modified polymeric method. Nanometric powders with primaries particles of ~20nm sizes and controlled agglomeration were obtained which was an innovation for BTZ powders prepared by chemical methods. For the films deposition, the suspensions stability was studied and thick films with excellent homogeneity were deposited using the electrophoresis technique (EDP). The developing of the technique allowed the thicknesses control using the deposition parameters. The characteristics of the experimental apparatus were optimized in such a way as to allow the sintering of thick films whose dimensions were up to 70mm in length, 10mm in width and variable thicknesses. The step times in each stage were dependent on the velocity and scan number. The maximum temperature that can be achieved in the thick film, during each scan, and for a fixed rated laser power was correlated with the relative density. The related thermal process during the continuous laser scan acted in a similar way as a two-step sintering. To improve the densification of the films, we started to add the compound Bi4Ti3O12 (BIT) (1 e 2 mol %) to BTZ during the deposition. The utilization of the system developed for the sintering by laser scan alongwith the adding of the BIT resulted in a grain size decrease and a significant decrease in apparent porosity. For the 2mol% additivation we obtained films with excellent density (apparent porosity of ~4%) and reduced grain size (~200nm), which is an unpublished result for thick films. The laser sintering resulted in films with a higher dielectric permittivity in relation to the conventionally sintered film. The reactions between BTZ and BIT were explored using the techniques of impedance spectroscopy, thermal analysis and X-ray diffraction.
47

Gravure-offset printing in the manufacture of ultra-fine-line thick-films for electronics

Pudas, M. (Marko) 27 March 2004 (has links)
Abstract In gravure offset printing, ink is transferred with the help of an offset material from a patterned gravure plate to a substrate. This thesis is concerned with the study and further development of this printing process for electronics; on alumina, glass and polymers. The work has been divided into five parts. In the first section, the printing process is described. The second section describes the composition of the inks for gravure offset printing and the resulting ink properties. It also presents the ink transfer mechanism; the model that explains how the ink is transferred between an offset material and a substrate. The third chapter details the printing process explained by a solvent absorption mechanism. The forth chapter describes the firing/curing of printed samples and their properties. The last chapter describes applications of the method. The inks used to produce conductors on ceramics (ceramic inks) and conductors on polymers (polymer inks) contain silver particles, and were under development for gravure offset printing. The major achieved properties were the high ink pickup to the offset blanket and high transfer percentage to the substrate. 100% ink transfer from blanket to substrate for ceramic inks and almost 100% ink transfer for polymer inks was obtained. The printing of ceramic inks was able to produce 8 μm of relatively thick, 300 μm wide lines with < 10 mΩ/sq. resistance. The minimum line width for conducting lines was 35 μm, with one printing. Multi printing was applied producing as many as 10 times wet-on-wet multiprinted lines with 100 % ink transfer from blanket to substrate resulting in a square resistance of 1mΩ/sq. Polymer inks were able produce a square resistance of 20 mΩ/sq. for 300 μm wide lines after curing at 140 °C for about 15 min, and the minimum width was down to 70 μm. In the optimised manufacturing process, the delay time on the blanket was reduced to 3 s. In addition to ultra-fine-line manufacturing of conductors, the method enables the manufacture of special structures e.g. laser-solder contact pads with 28/28 μm lines/spaces resolution. With industrial printing equipment it is possible to produce 100 m2/h with the demonstrated printing properties.
48

Processamento por infusão a vácuo de compósitos espessos aramida/epóxi e análise do desempenho sob impacto

Nunes, Stephanie Gonçalves January 2018 (has links)
Em aplicações que requerem solicitações de impacto, compósitos de matriz polimérica reforçados com fibra de aramida se destacam, principalmente em relação aos metais, devido a propriedades como alta resistência e rigidez específicas, que dão origem a sistemas mais leves e de alta performance. Quando voltados para aplicações de impacto, principalmente a alta velocidade, tais compósitos são, em sua maioria, moldados por compressão ou autoclave, a partir de pré-impregnados. No entanto, tais combinações de processamentos e matéria-prima acarretam em estruturas de elevado custo, tornando a infusão a vácuo uma opção atrativa, além de permitir a obtenção de peças grandes e complexas, dimensionalmente acuradas e partes integradas. Porém, a obtenção de um compósito espesso reforçado por fibra de aramida com elevado desempenho ao impacto por tal método de fabricação ainda é um desafio. Neste contexto, este trabalho aborda o efeito da espessura no processamento por infusão a vácuo de compósitos aramida/epóxi e seu desempenho em aplicações que requerem solicitações de impacto (baixa e alta velocidade) Para isso, foram produzidos compósitos com 5, 8, 13, 18, 23 e 28 camadas de aramida e caracterizados por ultrassom C-scan, microscopia ótica, densidade, teor de constituintes, testes mecânicos (flexão, short beam e indentação quase-estática) e cargas de impacto de baixa e alta velocidade (drop-weight e balístico). Todos os compósitos apresentaram boa homogeneidade na distribuição da matriz ao longo do reforço, com um teor de fibra de ≈60%, e valores de resistência short beam elevados (17,3 - 23,6 MPa). A performance sob impacto (baixa e alta velocidade) foi comparável à de compósitos fabricados por compressão ou autoclave, tendo os compósitos a partir de 18 camadas resistido ao projétil 9 mm Luger FMJ e o de 28 camadas resistido ao projétil .357 Magnum FMJ, podendo ser classificados como nível FB2 e FB3, respectivamente, de acordo com a norma europeia EN 1522. Portanto, o processamento de infusão a vácuo mostrou ser uma alternativa adequada para produzir compósitos espessos de aramida/epóxi (até 12 mm), substituindo rotas de processamento mais caras. / In applications that require impact solicitations, polymer matrix composites reinforced with aramid fiber stand out, especially in relation to metals, due to properties such as high specific strength and stiffness, which give rise to lighter and high-performance systems. When used for impact applications, especially at high speed, such composites are mostly molded by compression or autoclaved, from prepregs. However, such combinations of processing and raw material lead to high cost structures, making vacuum infusion an attractive option, as well as allowing the production of large, complex, dimensionally accurate and integrated parts. Nonetheless, obtaining a thick composite reinforced by aramid fiber with high impact performance by such manufacturing method is still a challenge. In this context, this work addresses the effect of the thickness in the vacuum infusion processing of aramid/epoxy composites and its performance in applications that require impact solicitations (low and high speed) For this, composites with 5, 8, 13, 18, 23 and 28 layers of aramid were produced and characterized by ultrasonic C-scan, optical microscopy, density, constituent content, mechanical tests (flexion, short beam and quasi-static indentation) and low- and high-speed impact loads (drop-weight and ballistic). All composites presented good homogeneity in the matrix scattering along the reinforcement, with a fiber content of ≈ 60%, and high short beam resistance values (17.3 - 23.6 MPa). The performance under impact (low and high speed) was comparable to that of composites processed by compression or autoclave, the composites with 18 layers resisted to the 9 mm Luger FMJ projectile and the one with 28 layers resisted to the .357 Magnum FMJ projectile, being classified as level FB2 and FB3, respectively, according to the European standard EN 1522. In summary, vacuum infusion processing proved to be a suitable alternative to produce thick aramid/epoxy composites (up to 12 mm), replacing more expensive processing routes.
49

The Necessity and Possibility of Decolonizing the Understanding of Chinese-ness

Zhang, Tao 01 September 2021 (has links) (PDF)
In this dissertation, I explore how crossing national borders has made me aware of the many identity borders that I have crossed as a transnational Chinese, and how I am caught up in identity politics between the “Chinese,” who do not necessarily always identify as “Chinese” in the transnational context. However, as a racialized group in the U.S., transnational Chinese are perceived as a homogeneous population, usually through racially (“Yellow Peril” or “Chinese Virus”) and politically (“Red Scare”) charged lenses measured by Western/U.S. binaristic and hierarchical standards. Therefore, in this research project, I problematize dominant U.S. race logic, i.e., the White/Non-White binary, for its limited capabilities of understanding and explaining identity, communication, culture, and power in an increasingly interconnected world; and I also call for an alternative theorizing of race and identity in the transnational context. Border crossings within the conditions of contemporary globalization have intensified interconnectivities and complicated how we comprehend and communicate our identities. It thus becomes essential to find ways to “unsettle and restage” racial and cultural differences in the context of globalization (Shome & Hegde, 2002a, p. 174-5). With a different skin color, speaking English with a foreign accent while being perceived as “Model Minorities,” transnational Chinese have lately been ascribed with another pathologized identity label: “Chinese Virus,” which may be understood as an extension of the “Yellow Peril” rhetoric. Furthermore, within the Chinese communities, due to historical reasons, colonialism, political unrest, and civil war, many Taiwanese and Hong Kongers identify themselves very differently from mainland Chinese. When crossing borders to live together in the U.S., the identity tensions among Chinese ethnicities in addition to the interracial confrontations between transnational Chinese and local racial groups only make understanding what it means to be Chinese on the racial landscape of the U.S. even more complex.I weave together Yep’s (2010) notion of thick(er) intersectionalities and Kraidy’s (2005) description of transnationalism to build my conceptual framework. On the one hand, thick(er) intersectionalities advocates for more complex and embodied ways of theorizing intersectional identities and “the interplay between individual subjectivity, personal agency, systemic arrangements, and structural forces” (p. 173). On the other, transnationalism helps make sense of transnational identities with “a shifting location of contradictions that straddles multiple viewpoints,” which cannot be defined “in binary and essentialist terms” (Bardhan & Zhang, 2017, p. 288). I thus examine why an in-depth, transnational understanding of Chinese identity is necessary and how to move toward such an understanding, including that of racial, cultural, linguistic, and political identities of transnational Chinese living in the U.S., especially in the context of the current trade tensions between the U.S. and China, two nations tightly connected economically while largely differing culturally and politically.Methodologically, I employ a mixed-method approach by applying autoethnography and in-depth interview as my primary research methods. The dissertation mainly addresses three research questions through a communicative lens: 1) What does it mean to live in the U.S. as transnational Chinese? 2) How do transnational Chinese make sense of Chinese-ness(es) in such a context? 3) What is at stake in understanding Chinese-ness in a transnational context that necessitates an alternative theorization of race to the dominant/White U.S. race ideology? The findings show that there is no singular definition of what Chinese-ness(es) is(are) and what it(they) entail(s). It is a thick and fluid concept that is unique to each transnational Chinese based on their lived experiences and subjected to their own understandings while also constrained in the larger social framework by Chinese and U.S. cultural scripts and contexts. Chinese-ness, to transnational Chinese, cannot be compartmentalized in the limited identity categories specific to either cultural context. Being exposed to a broader world with multiple cultural references, they are flexible enough to creatively identify, dis-identify, or even counter-identify with either their avowed identities, or ascribed identities, or both in either or both cultural contexts. The complexities, specificities, and particularities of their transnational identity experiences, thus, cannot be adequately understood within the confines of simple intersections of U.S.-centric identity categories. I conclude that Chinese-ness(es) is local and global, racial and ethnic, cultural and political, and spatial and temporal. There is no such thing as a singular, uniform Chinese-ness. Not even in the imaginary. This study may contribute to critical intercultural communication scholarship by situating knowledge of race, identity, and power in a very specific and complex context that includes the U.S. but is transnational in scope. Further, with an aim to provincialize dominant U.S. race logic, it makes an effort to transnationalize and internationalize theorizing of race and identity. Finally, speaking in a voice from a non-Western perspective currently situated in the West, I practice self-reflexivity throughout my writing with the hope of avoiding re-essentializing identity, race, and power in a covert “oppressor-oppressed” Manichean dualism that I attempt to deconstruct.
50

BOURDON Tube Studies

Lee, Edward Tong 05 1900 (has links)
The objective of this study is to elucidate as much as possible the theory and analysis of BOURDON tubes. Both thick-walled and thin-walled tubes are considered. Three papers, representative of the state-of-the-art of BOURDON tube analysis, are reviewed (References 1, 2, and 6): <p> 1. Wuest, W. "Theory of High-Pressure BOURDON Tubes". </p><p> 2. Andreeva, L. E>, "Elastic Elements of Instruments" </p> <p> 3. Dressler, R., "Elastic Shell-Theory Formulation for BOURDON Tubes" </p><p> Reanalysis of (3) above, with a different approach (Appendix A) checked and completed the general formulation by Dressler. The final forms of all necessary equations, boundary conditions, etc. to the solution of the three governing equations of the BOURDON tube with an elliptical cross-section are given. </p><p> Comparison of results of Andreeva's sensitivity equation with test data of Kardos, Mason and Exline (References 3, 4 and 5) using a qualitative approach as set out by Kardos (References 3 and 17) showed good correlation. </p><p> The study concludes with recommendations for the approach of future research and preliminary design procedures for BOURDON tubes. </p> / Thesis / Master of Engineering (ME)

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