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III-V materials such as indium arsenide (InAs) and gallium arsenide (GaAs) are increasingly used in electronic and photovoltaic devices. The extensive application of these materials may lead to release of III-V ionic species during semiconductor manufacturing or disposal of decommissioned devices into the environment. Although arsenic is recognized as an important contaminant due to its high toxicity, there is a lack of information about the toxic effects of indium and gallium ions. In this study, acute toxicity of As(III), As(V), In(III) and Ga(III) species was evaluated using two microbial assays testing for methanogenic activity and 02 uptake, as well as two bioassays targeting aquatic organisms, including the marine bacterium Aliivibrio fischeri (bioluminescence inhibition) and the crustacean Daphnia magna (mortality). The most noteworthy finding was that the toxicity is mostly impacted by the element tested. Secondarily, the toxicity of these species also depended on the bioassay target. In(III) and Ga(III) were not or only mildly toxic in the experiments. D. magna was the most sensitive organism for In(III) and Ga(III) with 50% lethal concentrations of 0.5 and 3.4 mM, respectively. On the other hand, As(III) and As(V) caused clear inhibitory effects, particularly in the methanogenic toxicity bioassay. The 50% inhibitory concentrations of both arsenic species towards methanogens were about 0.02 mM, which is lower than the regulated maximum allowable daily effluent discharge concentration (2.09 mg/L or 0.03 mM) for facilities manufacturing electronic components in the US. Overall, the results indicate that the ecotoxicity of In (III) and Ga(III) is much lower than that of the As species tested. This finding is important in filling the knowledge gap regarding the ecotoxicology of In and Ga.

of the solder. In this thesis, a new fabrication process for incorporating NiTi particles (10 vol.% NiTi) into Sn-In solder (80Sn-20In) using liquid phase sintering has been developed. The microstructures of the solders were characterized. The behavior of the solder joints during thermomechanical cycling was also characterized and the results showed that the shear stress induced in the composite solder joint is significantly reduced relative to that in the monolithic solder joint due to the generation of a back-stress associated with the B19Å fÅ *B2 phase transformation of the NiTi particles during the heating part of the cycle. This causes an appreciable reduction of the total inelastic strain range during cycling.

Completely inorganic nanoscale clusters play an essential role in many aspects of inorganic chemistry, materials chemistry, and geochemistry. The underlying dynamic behavior of these species in solution defines how and why they make successful thin film precursors as well as exist naturally in the environment. There have been a limited number of previous solution studies involving inorganic nanoscale clusters due to the lack of spectroscopic handles and availability of analytical techniques. This dissertation outlines the available and appropriate characterization techniques needed for identifying and studying inorganic nanoscale species and then uses proton Nuclear Magnetic Resonance (1H-NMR) and Diffusion Ordered Spectroscopy (DOSY) to fully characterize the Ga13-xInx(µ3-OH)6(µ-OH)18(H2O)24(NO3)15 (0 ≤ x ≤ 6) cluster series in solution. This research lays a foundation for a multitude of future studies on the dynamic behavior of these species that was previously unachievable. This dissertation includes previously published and unpublished co-authored material.

Neste trabalho os diferentes sistemas eletrocatalíticos PtIn/C, PtRu/C, PtRuIn/C e suas diferentes proporções mássicas foram sintetizados pelo método de redução por Borohidreto de Sódio, a fim de serem utilizados como ânodo na célula a combustível alcalina de metanol direto (DMFC). Os materiais obtidos foram caracterizados pelas técnicas de EDX, DRX e MET. O método de redução aplicado na síntese se mostrou efetivo, uma vez que as partículas apresentaram boa dispersão no suporte de carbono Vulcan XC72, de acordo com as analises de EDX e MET. Os resultados obtidos por DRX evidenciaram em todos os difratogramas apresentados a estrutura CFC da platina e um relativo deslocamento do pico equivalente ao plano (220) para valores maiores e menores que 2θ. O tamanho médio do cristalito e os parâmetros de rede calculados indicaram a inserção de átomos de Índio e Rutênio à estrutura da Platina, supondo a formação de ligas. A oxidação eletroquímica do metanol foi estudada por voltametria cíclica, cronoamperometria e curvas de polarização. Os experimentos eletroquímicos demonstraram que nos eletrocatalisadores binários com maior composição de Índio e Rutênio a eficiência catalítica frente a oxidação do combustível foi melhor e para os ternários, o eletrocatalisador que possuía maior composição de Rutênio se mostrou mais eficiente. Nos experimentos práticos em células a combustível, as curvas de polarização mostraram divergências de resultados com os obtidos por voltametria cíclica e cronoamperometria, justificadas por problemas de prensagem e descolamento de MEA\'s em sistemas que apresentaram maior quantidade de cocatalisador como Índio e Rutênio. / In this work the different electrocatalytic systems PtIn/C, PtRu/C, PtRuIn/C and their different mass proportions were synthesized by the sodium borohydride reduction method, in order to be used as an anode in the alkaline direct methanol fuel cell (DMFC). The obtained materials were characterized by EDX, DRX and MET techniques. The reduction method applied in the synthesis was effective, since the particles showed good dispersion in the carbon support Vulcan XC72, according to the EDX and MET analyzes. The results obtained by XRD showed in all the diffractograms presented the CFC structure of platinum and a relative displacement of the equivalent peak to the plane (220) for values greater than and less than 2θ. The mean crystallite size and the calculated net parameters indicated the insertion of Indium and Ruthenium atoms to the Platinum structure, assuming the formation of alloys. The electrochemical oxidation of methanol was studied by cyclic voltammetry, chronoamperometry and polarization curves. The electrochemical experiments showed that in the binary electrocatalysts with higher composition of Indium and Ruthenium, the catalytic efficiency against the oxidation of the fuel demonstrated a better result. Meanwhile the ternary, the electrocatalyst with the higher Ruthenium composition was more efficient. In terms of the practical experiments in fuel cells, the polarization curves showed divergences of results with those obtained by cyclic voltammetry and chronoamperometry, which can be justified by issues of pressing and detachment of MEA\'s in systems that presented higher amounts of cocatalysts such as Indium and Ruthenium.

Thesis (Ph.D.)--Chinese University of Hong Kong ,2001. / Includes bibliographical references. / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Mode of access: World Wide Web. / Abstracts in English and Chinese.

Yip Hin-lap = 以PEDOT:PSS為本的高份子發光器件中銦的擴散之研究 / 葉軒立. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2003. / Includes bibliographical references (leaves 113). / Text in English; abstracts in English and Chinese. / Yip Hin-lap = Yi PEDOT:PSS wei ben de gao fen zi fa guang qi jian zhong yin de kuo san zhi yan jiu / Ye Xuanli. / Abstract --- p.ii / 論文摘要 --- p.iv / Acknowledgements --- p.v / Table of Contents --- p.vi / List of Figures --- p.x / List of Tables --- p.xii / Chapter CHAPTER 1 --- INTRODUCTION --- p.1 / Chapter 1.1 --- Overview --- p.1 / Chapter 1.2 --- Conjugated Polymer --- p.3 / Chapter 1.2.1 --- Electronic and Geometric Configuration --- p.3 / Chapter 1.2.2 --- Charge Carriers --- p.7 / Chapter 1.2.3 --- Concept of Doping --- p.9 / Chapter 1.2.4 --- Electrical Conductivity and Charge Transport Mechanisms --- p.15 / Chapter 1.3 --- "Poly(3,4-ethylenedioxythiophene) [PEDOT]" --- p.16 / Chapter 1.4 --- Polymer Light Emitting Diodes --- p.20 / Chapter 1.4.1 --- Device Fabrication --- p.21 / Chapter 1.4.2 --- Material Design and Properties --- p.23 / Chapter 1.4.3 --- Interface and surface of PLED --- p.25 / Chapter 1.5 --- """Chemistry"" and Diffusion at Interface" --- p.27 / Chapter 1.6 --- Surface/Interface Modification with Self-Assembled Monolayers --- p.30 / Chapter 1.7 --- Aims of This Thesis --- p.33 / References --- p.34 / Chapter CHAPTER 2 --- INSTRUMENTATION --- p.38 / Chapter 2.1 --- X-ray Photoelectron Spectroscopy --- p.38 / Chapter 2.1.1 --- Fundamental Theory of XPS --- p.39 / Chapter 2.1.2 --- Qualitative Analysis using XPS --- p.43 / Chapter 2.1.2.1 --- Chemical Shifts --- p.43 / Chapter 2.1.2.2 --- Shake-up satellites --- p.45 / Chapter 2.1.2.3 --- Valence band structure --- p.45 / Chapter 2.1.3 --- Quantitative Analysis Using XPS --- p.46 / Chapter 2.1.4 --- Depth Profiling --- p.47 / Chapter 2.1.4.1 --- Non-Destructive Method Using Angled-Resolved XPS --- p.47 / Chapter 2.1.4.2 --- Destructive Method Using Ion Sputtering --- p.49 / Chapter 2.1.5 --- Instrumental Setup of XPS --- p.49 / Chapter 2.2 --- PLED Fabrication and Characterization System --- p.51 / Chapter 2.3 --- Current-Voltage-Luminescence (I-V-L) Measurement --- p.53 / Chapter 2.4 --- Electrical Measurement --- p.54 / Chapter 2.5 --- Kelvin Probe Measurement --- p.55 / Chapter 2.6 --- pH Measurement --- p.56 / Chapter 2.7 --- Film Thickness Measurement --- p.56 / Chapter 2.8 --- Contact Angle Measurement --- p.57 / References --- p.60 / Chapter CHAPTER 3 --- STABILITY OF PEDOT:PSS/ITO INTERFACE --- p.61 / Chapter 3.1 --- Introduction --- p.61 / Chapter 3.2 --- Sample Preparation --- p.62 / Chapter 3.3 --- Results and Discussion --- p.63 / Chapter 3.3.1 --- XPS of Core levels in PEDOT:PSS --- p.63 / Chapter 3.3.1.1 --- XPS of S 2p Core Level --- p.64 / Chapter 3.3.1.2 --- XPS of O Is Core Level --- p.66 / Chapter 3.3.1.3 --- XPS of C Is Core Level --- p.68 / Chapter 3.3.2 --- Composition Analysis of PEDOT:PSS Films --- p.71 / References --- p.80 / Chapter CHAPTER 4 --- ELECTRICAL AND ELECTRONIC PROPERTIES OF PEDOT:PSS WITH DISSOLUTED INDIUM --- p.81 / Chapter 4.1 --- Introduction --- p.81 / Chapter 4.2 --- Sample Preparation --- p.81 / Chapter 4.2.1 --- Four-Point Probe Measurement --- p.82 / Chapter 4.2.2 --- Current-Voltage Measurement --- p.82 / Chapter 4.2.3 --- Work Function Measurement --- p.83 / Chapter 4.2.4 --- XPS Experiment --- p.83 / Chapter 4.3 --- Results and Discussion --- p.85 / Chapter 4.3.1 --- Electrical Properties of PEDOT:PSS --- p.86 / Chapter 4.3.2 --- Electronic Properties of PEDOT:PSS --- p.89 / References --- p.97 / Chapter CHAPTER 5 --- BLOCKING REACTIONS BETWEEN ITO AND PEDOT:PSS WITH A SELF-ASSEMBLY MONOLAYER --- p.98 / Chapter 5.1 --- Introduction --- p.98 / Chapter 5.2 --- Sample Preparation --- p.99 / Chapter 5.3 --- Result and Discussion --- p.103 / Chapter 5.3.1 --- In Diffusion Blocking Effect by SAM --- p.103 / Chapter 5.3.2 --- PLED Devices Performance --- p.107 / References --- p.113 / Chapter CHAPTER 6 --- CONCLUSION --- p.114 / Chapter CHAPTER 7 --- FURTHER WORKS --- p.116