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Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 14 of 14 for “"metal impurities"”.
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Metal impurities in n-type crystalline silicon for photovoltaics : simulation, synchrotron-based characterization, and mitigation
… mapping is used to non-destructively evaluate metal impurity evolution during processing. This thesis demonstrates that metal impurity redistribution during solar cell processing is similar in n- and p-type mc-Si but the relative electrical impact of point defect and precipitated impurities is …
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Development of germanium based sulphide glass by chemical vapour deposition (CVD)
… and an exceptionally low level of transition metal impurities in this glass have been achieved.
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Synthesis and evaluation of rare-earth doped glasses and crystals for optical refrigeration
… a material with significantly reduced transition-metal impurities. A method for OH- impurity removal and ultra-drying of the metal fluorides was also improved upon. Several characterization tools were used to quantitatively and qualitatively verify purity, including inductively-coupled plasma mass …
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Ab initio Beschreibung der elektronischen Struktur und der Transporteigenschaften von metallischen Nanodrähten
… The influence of substitutional transition metal impurities on the electronic structure and the conductance of the 2x2 Cu wire is studied. A spin-dependent discussion is given for magnetic impurities.
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High temperature investigations of crystalline silicon solar cell materials
… understanding of the behavior of defect and impurities in solar cell materials. Since solar cell processing occurs at high temperatures, experiments are needed that allow characterization of solar cell materials at high temperatures representative of manufacturing conditions, at the …
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Electrical impact assessment of dislocations in silicon materials for solar cells
… defects (e.g., dislocations, grain boundaries, metal impurities) than more expensive single-crystalline growth methods. A higher density of defects, particularly dislocations, results in a greater density of charge-carrier recombination centers, which reduce a solar cell's efficiency. …
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Quantum phenomena in disordered conductors
… the influence of non-magnetic transition element impurities on conventional superconductivity. We find that phonon coupling at impurities counteracts the traditional effects which dominate Tc suppression in the non-magnetic limit. In some cases, we predict that non-magnetic transition metal …
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Transmission and ellipsometric spectroscopy of impurities in metals
Submitted by Carolyn Mead (cmead2@illinois.edu) on 2011-06-13T18:01:14Z No. of bitstreams: 1 1982_denton.pdf: 5959168 bytes, checksum: 7e03456f1529061a5f3c7a4102ebfd74 (MD5)
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Trace element contaminants in the Kuwait water production system
… water containes organic, inorganic and trace metal impurities within the recommended international standard limits. The purpose of this work is to identify the source of selected trace metals present in the drinking water in Kuwait. Chromium, copper, iron, lead, manganese, nickel, vanadium and …
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Detecting and gettering chromium impurities in photovoltaic crystalline silicon
… of the most significant cost levers. Transition metal impurities can degrade silicon wafer-based solar cell efficiencies at concentrations as low as 1010 cm3 . By removing interstitial metals from the bulk and/or collecting interstitial metals at heterogeneous nucleation sites, phosphorous …
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Effects of various salt purity levels on lipid oxidation and sensory characteristics of ground turkey and pork
… desire sea salt which may also contain trace metals and the government is demanding a reduction in sodium. Therefore a need exists to understand how varying impurity levels in salt affect meat quality. This study evaluated the effects of various salt preparations on lipid oxidation, sensory …
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Quantitative impurities effects on temperatures of tin and aluminium fixed-point cells
… The ITS-90 uses the freezing points of metals to define temperature fixed points. It also uses long-stemplatinum resistance thermometers to interpolate between the fixed points from 660 °Cdown to 84 K (if one includes the Argon triple point). Impurities are a major source of uncertainty …
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Defect engineering strategies for solar grade silicon and their optimization by predictive simulation
… of different representative transition-metal impurities are calculated at different stages of the solar cell production chain: in the final device, in the multi-crystalline (mc) Si wafer, and in the Si feedstock material. Along the production chain, impurity concentrations are assumed to …
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Phosphorus speciation, agronomic performance and soil nutrient testing for waste recovered fertiliser use in Northern Irish soil
… differed markedly in colour/appearance, texture, metal content and solubility • Tested struvites all had similar P-speciation, but minor impurity phases were detected • There was no significant difference between the struvite samples and triple-superphosphate (TSP) with respect to either plant …