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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

Conductive anodic filament reliability of fine-pitch through-vias in organic packaging substrates

Ramachandran, Koushik 13 January 2014 (has links)
This research reports for the first time conductive anodic filament reliability of copper plated-through-vias with spacing of 75 – 200 µm in thin glass fiber reinforced organic packaging substrates with advanced epoxy-based and cyclo-olefin polymer resin systems. Reliability studies were conducted in halogenated and halogen-free substrates with improved test structure designs including different conductor spacing and geometry. Accelerated test condition (temperature, humidity and DC bias voltage) was used to investigate the effect of conductor spacing and substrate material influence on insulation reliability behavior. Characterization studies included gravimetric measurement of moisture sorption, extractable ion content analysis, electrical resistance measurement, impedance spectroscopy measurement, optical microscopy and scanning electron microscopy analysis and elemental characterization using energy dispersive x-ray spectroscopy. The accelerated test results and characterization studies indicated a strong dependence of insulation failures on substrate material system, conductor spacing and geometry. This study presents advancements in the understanding of failure processes and chemical nature of failures in fine-pitch copper plated-through-vias in newly developed organic substrates and demonstrates potential methods to mitigate failures for high density organic packages.
2

Preparação de novos eletrodos modificados mistos contendo partículas metálicas e sua utilização em hidrogenações eletrocatalíticas de substratos orgânicos / Preparation of new mixed modified electrodes containing metallic particles and its uses in electrocatalytic hydrogenation of organic substrates

Purgato, Fabiana Lopes da Silva 10 October 2005 (has links)
A preparação do EM Pd foi escolhida pelo fato de já terem sido estudados em nossos laboratórios os EM Ni e EM Pt. Estes três eletrodos modificados (EMs) foram utilizados nas hidrogenações eletrocatalíticas (HEC) de substratos orgânicos para comparação de suas reatividades. A preparação deste novo eletrodo modificado revestido pelo filme misto poli-[éter alílico do p-(2-etilamônio) benzeno] e co-monômero éter fenil e alílico no suporte de bastão de grafite contendo partículas de Pd foi iniciada com a síntese do éter alílico do p-(2-etilamônio) benzeno a partir da acetamida do p-(2-etilamônio). A utilização do co-monômero éter fenil e alílico na estrutura do filme polimérico se fez na tentativa de espaçar a malha polimérica para conseguir melhorar os resultados das HEC de substratos orgânicos, pois estes teriam maior facilidade de permear (difundir) pela malha e também proporcionar um aumento na quantidade de partículas de paládio incorporadas ao filme. Depois da preparação, utilização e comparação dos EMs Ni, Pd e Pt foram desenvolvidos novos EMs mistos visando aumentar a eficiência nas HEC dos substratos orgânicos. O EM misto Ni/Ni já havia sido preparado e estudado nas HEC mostrando uma eficiência moderada. Preparou-se então os EMs mistos Ni/Pd e Ni/Pt para compará-los com o EM Ni/Ni e com os EMs Ni, Pd e Pt para verificar se ocorreria um aumento na eficiência nas HEC. A preparação destes EMs mistos foi feita utilizando a técnica de electroless. A eficiência dos EMs foi verificada através da GH a partir de uma solução de ácido sulfúrico, do volume de hidrogênio gerado, medidas de potencial de circuito aberto e de reação de HEC de substratos orgânicos. A caracterização dos EMs foi feita pelo cálculo da massa de partículas incorporadas e análise de raios X e MEV-EDX. Os substratos orgânicos estudados nas HEC foram: benzaldeído, n-valeraldeído, isoforona, 2-cicloexen-1-ona, cicloexanona, acetofenona, benzofenona, eugenol, isoeugenol, fenilacetileno, 3-butin-1-ol, benzonitrila, fenilacetonitrila, malononitrila e valeronitrila. Comparando-se os EMs Ni, Pt, Pd, Ni/Ni, Ni/Pd e Ni/Pt, o que levou aos melhores rendimentos nas HEC foi o EM misto Ni/Pd. A HEC da acetofenona e benzofenona levou a resultados inéditos na literatura com a hidrogenação dos anéis aromáticos. / The modified electrode (ME) Pd was chosen because ME Ni and ME Pt had already been studied in our laboratory. These three different MEs were used in the electrocatalytic hydrogenation (ECH) of organic substrates so that their reactivity could be compared. The preparation of the new modified electrode ME Pd by using the mixed film poly-[ether allyl p-(2-ammoniumethyl) benzene] and the co-monomer allyl phenyl ether in carbon stick containing Pd particles. The preparation was initiated by synthesizing the allyl p-(2-ammoniumethyl) benzene ether through reaction with the acetamyde of the p-(2-ammoniumethyl) group. The co-monomer allyl phenyl ether in a polymeric film was used in an attempt to obtain more space between the polymeric film and to achieve better results in the ECH of organic substrates, since they could be introduced through the polymer and increase the quantity of Pd particles of incorporated in to the film. After the preparation of the MEs Ni, Pd and Pt and after they had been used and compared, new mixed MEs were developed in order to study their efficiency in the ECH of organic substrates. Mixed ME Ni/Ni had already been prepared and studied in our laboratory and it was shown to be moderately efficient for ECH. Mixed ME Ni/Pd and Ni/Pt were prepared so that they could be compared with mixed ME Ni/Ni, ME Ni, ME Pd and ME Pt. The preparation of these mixed MEs was carried out by electroless deposition. The efficiency of these MEs was verified by hydrogen generation from a mineral acid solution, hydrogen generation volume, potential of the open circuit and ECH of organic substrates. The characterization of the MEs was done by calculating the mass of incorporated particles and by SEM-EDX analyses. The organic substrates used for in ECH were benzaldehyde, n-valeraldehyde, isophorone, 2-cyclohexen-1-one, cyclohexanone, acetophenone, benzophenone, eugenol, isoeugenol, phenylacetylene, 3-butin-1-ol, benzonitrile, phenylacetonitrile, malononitrile and valeronitrile. A comparison of these MEs shows that the mixed ME Ni/Pd are the most efficient for ECH for all studied substrates. Acetophenone and benzophenone gave fully hydrogenated products; a fact that has not yet been published in the literature.
3

A smart wireless integrated module (SWIM) on organic substrates using inkjet printing technology

Palacios, Sebastian R. 22 May 2014 (has links)
This thesis investigates inkjet printing of fully-integrated modules fabricated on organic substrates as a system-level solution for ultra-low-cost and eco-friendly mass production of wireless sensor modules. Prototypes are designed and implemented in both traditional FR-4 substrate and organic substrate. The prototype on organic substrate is referred to as a Smart Wireless Integrated Module (SWIM). Parallels are drawn between FR-4 manufacturing and inkjet printing technology, and recommendations are discussed to enable the potential of inkjet printing technology. Finally, this thesis presents novel applications of SWIM technology in the area of wearable and implantable electronics. Chapter 1 serves as an introduction to inkjet printing technology on organic substrates, wireless sensor networks (WSNs), and the requirements for low-power consumption, low-cost, and eco-friendly technology. Chapter 2 discusses the design of SWIM and its implementation using traditional manufacturing techniques on FR-4 substrate. Chapter 3 presents a benchmark prototype of SWIM on paper substrate. Challenges in the manufacturing process are addressed, and solutions are proposed which suggest future areas of research in inkjet printing technology. Chapter 4 presents novel applications of SWIM technology in the areas of implantable and wearable electronics. Chapter 5 concludes the thesis by discussing the importance of this work in creating a bridge between current inkjet printing technology and its future.
4

The effect of soluble organic carbon substrates, and environmental modulators on soil microbial function and diversity

Hoyle, Frances Carmen January 2007 (has links)
[Truncated abstract] The principal aim of this thesis was to examine the response of the microbial community to the addition of small amounts (<50 μg C g-1 soil) of organic C substrates (‘trigger molecules’) to soil. This addition is comparative to indigenous soluble C concentrations for a range of soil types in Western Australia (typically measured between 20 and 55 μg C g-1 soil). Previously it has been reported that the application of trigger molecules to European soils has caused more CO2-C to be evolved (up to six fold) than was applied . . . Findings from this study indicated that there was an additional CO2 release (i.e. greater than the C added) on application of organic C substrates to some soil treatments. However, findings from this study indicate that the response of the microbial community to small additions of soluble C substrate is not consistent for all soil types and may vary due to greater availability of C, and supports the premise that microbial responses vary in a yet to be predicted manner between soil type and ecosystems. Differences in microbial response to the addition of soluble organic C are likely attributable to differences in soil attributes and environmental factors influencing both the diversity of microbes present and the frequency of food events. Theoretically, trigger molecules could also provide a possible control mechanism for microorganisms in arable farming systems. These mechanisms include stimulating either targeted pathogenic microorganisms that starve after depletion of a suitable substrate; or stimulating beneficial microorganisms to manipulate nutrient cycling, by targeting specific functional groups and altering mineralisation and immobilisation turnover rates.
5

Preparação de novos eletrodos modificados mistos contendo partículas metálicas e sua utilização em hidrogenações eletrocatalíticas de substratos orgânicos / Preparation of new mixed modified electrodes containing metallic particles and its uses in electrocatalytic hydrogenation of organic substrates

Fabiana Lopes da Silva Purgato 10 October 2005 (has links)
A preparação do EM Pd foi escolhida pelo fato de já terem sido estudados em nossos laboratórios os EM Ni e EM Pt. Estes três eletrodos modificados (EMs) foram utilizados nas hidrogenações eletrocatalíticas (HEC) de substratos orgânicos para comparação de suas reatividades. A preparação deste novo eletrodo modificado revestido pelo filme misto poli-[éter alílico do p-(2-etilamônio) benzeno] e co-monômero éter fenil e alílico no suporte de bastão de grafite contendo partículas de Pd foi iniciada com a síntese do éter alílico do p-(2-etilamônio) benzeno a partir da acetamida do p-(2-etilamônio). A utilização do co-monômero éter fenil e alílico na estrutura do filme polimérico se fez na tentativa de espaçar a malha polimérica para conseguir melhorar os resultados das HEC de substratos orgânicos, pois estes teriam maior facilidade de permear (difundir) pela malha e também proporcionar um aumento na quantidade de partículas de paládio incorporadas ao filme. Depois da preparação, utilização e comparação dos EMs Ni, Pd e Pt foram desenvolvidos novos EMs mistos visando aumentar a eficiência nas HEC dos substratos orgânicos. O EM misto Ni/Ni já havia sido preparado e estudado nas HEC mostrando uma eficiência moderada. Preparou-se então os EMs mistos Ni/Pd e Ni/Pt para compará-los com o EM Ni/Ni e com os EMs Ni, Pd e Pt para verificar se ocorreria um aumento na eficiência nas HEC. A preparação destes EMs mistos foi feita utilizando a técnica de electroless. A eficiência dos EMs foi verificada através da GH a partir de uma solução de ácido sulfúrico, do volume de hidrogênio gerado, medidas de potencial de circuito aberto e de reação de HEC de substratos orgânicos. A caracterização dos EMs foi feita pelo cálculo da massa de partículas incorporadas e análise de raios X e MEV-EDX. Os substratos orgânicos estudados nas HEC foram: benzaldeído, n-valeraldeído, isoforona, 2-cicloexen-1-ona, cicloexanona, acetofenona, benzofenona, eugenol, isoeugenol, fenilacetileno, 3-butin-1-ol, benzonitrila, fenilacetonitrila, malononitrila e valeronitrila. Comparando-se os EMs Ni, Pt, Pd, Ni/Ni, Ni/Pd e Ni/Pt, o que levou aos melhores rendimentos nas HEC foi o EM misto Ni/Pd. A HEC da acetofenona e benzofenona levou a resultados inéditos na literatura com a hidrogenação dos anéis aromáticos. / The modified electrode (ME) Pd was chosen because ME Ni and ME Pt had already been studied in our laboratory. These three different MEs were used in the electrocatalytic hydrogenation (ECH) of organic substrates so that their reactivity could be compared. The preparation of the new modified electrode ME Pd by using the mixed film poly-[ether allyl p-(2-ammoniumethyl) benzene] and the co-monomer allyl phenyl ether in carbon stick containing Pd particles. The preparation was initiated by synthesizing the allyl p-(2-ammoniumethyl) benzene ether through reaction with the acetamyde of the p-(2-ammoniumethyl) group. The co-monomer allyl phenyl ether in a polymeric film was used in an attempt to obtain more space between the polymeric film and to achieve better results in the ECH of organic substrates, since they could be introduced through the polymer and increase the quantity of Pd particles of incorporated in to the film. After the preparation of the MEs Ni, Pd and Pt and after they had been used and compared, new mixed MEs were developed in order to study their efficiency in the ECH of organic substrates. Mixed ME Ni/Ni had already been prepared and studied in our laboratory and it was shown to be moderately efficient for ECH. Mixed ME Ni/Pd and Ni/Pt were prepared so that they could be compared with mixed ME Ni/Ni, ME Ni, ME Pd and ME Pt. The preparation of these mixed MEs was carried out by electroless deposition. The efficiency of these MEs was verified by hydrogen generation from a mineral acid solution, hydrogen generation volume, potential of the open circuit and ECH of organic substrates. The characterization of the MEs was done by calculating the mass of incorporated particles and by SEM-EDX analyses. The organic substrates used for in ECH were benzaldehyde, n-valeraldehyde, isophorone, 2-cyclohexen-1-one, cyclohexanone, acetophenone, benzophenone, eugenol, isoeugenol, phenylacetylene, 3-butin-1-ol, benzonitrile, phenylacetonitrile, malononitrile and valeronitrile. A comparison of these MEs shows that the mixed ME Ni/Pd are the most efficient for ECH for all studied substrates. Acetophenone and benzophenone gave fully hydrogenated products; a fact that has not yet been published in the literature.
6

Hydrogeomorphic classification of mire ecosystems within the Baker and Pascua Basins in the Region Aysén, Chilean Patagonia

Martínez, Ana Carolina Rodríguez 15 September 2015 (has links)
Zehn unerforschte und natürliche Moore entlang der Flüsse Baker und Pascua in der Region Aysén, im chilenischen Patagonien, wurde untersucht, um Informationen über ihre Entstehung, Hydrologie, Geomorphologie, Stratigraphie, Ökologie und Wasser- und Kohlenstoffspeichervermögen zu gewinnen. Es wurden acht verschiedene ökologische Moortypen identifiziert und fünf Moortypen unterscheidbar durch ihr geohydromorphologisches Setting mit insgesamt elf verschiedenen organischen Moorsubstraten. Die gesammelten Information erlauben erste Abschätzungen der Torf-, Süßwasser- und Kohlenstoffmengen, die in den Mooren Ayséns gespeichert sind, sowie der jährlichen Torfakkumulationsraten. Die Moortypen und die in ihnen vorkommenden organischen Substrate wurden in einem geohydromorphologischen Klassifizierungssystem zusammengefasst, welches wichtige hydrologische, geomorphologische, ökologische, bodenkundliche und landschaftliche Parameter integriert. Forschung und Kommunikation über die chilenischen Moore sollen durch diese Arbeit unterstützt werden, um angemessene Monitoring Tools und partizipative Naturschutzstrategien zu entwickeln, die für die Erhaltung dieser Ökosysteme und ihrer Kreisläufe anwendbar sind. / Ten unexplored and pristine mires along the Baker and Pascua River Basins in Aysén, Chilean Patagonia, were examined, generating information about their origin, hydrology, geomorphology, stratigraphy, ecology, and carbon and water storage capacities. Eight mire types ecologically differentiable, associated with five main mire types separable by their hydrology and geomorphology were detected, as well as eleven organic substrate types forming mire soils. The information gathered allows for a first estimation of the peat, fresh water and carbon content stored in the mires of Aysén, as well as for an average growth and annual accumulation rate of the peat. Mire types and their associated substrates are systematized in a hydrogeomorphic classification system, integrating important landscape, hydrological, geomorphical, ecological and pedological components. Research and communication about mires in the Chilean Patagonia should be further supported to generate accurate monitoring tools and participative conservation strategies that are replicable for the preservation of these ecosystems and its balance.

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