No description available.

No description available.

No description available.

Temporal variation in the levels of Cu and Cd in zooplankton, phytoplankton and water taken from five pelagic stations in Hamilton Harbour during three separate sampling periods (June, August and October/November 1990) was examined. Significant seasonal variation occurred in the Cu and Cd levels measured in water and phytoplankton (Cu Water: df=2, F=32.28, P≤.0001, Cu Phytoplankton: df=2, F=48.94, P≤.0001 and Cd Water: df=2, F=18.98, P≤.0001, Cd Phytoplankton: df=2, F=58.81, P≤.0001). However, the Cu levels observed in zooplankton did not vary significantly with season (df=2, F=1.79, P≤.1919). The maximal levels of Cd in zooplankton in November may be due to increased ingestion of material that is resuspended during turnover. Similarly, the peak levels of Cu and Cd recorded in November in phytoplankton may be due to a combination of processes: a) change in the size structure of the phytoplankton community to smaller individuals with higher metal sorption capacities and/or b) contamination of phytoplanktonic tissue samples by resuspended material. Phytoplankton metal levels (Cu and Cd) are negatively correlated with chl a concentrations (n=45, r=.8171, ≤.0001 and n-41, r=-.5961, P≤. 0001, respectively). These relationships are likely the result of a dilution effect. Zooplankton Cd levels were positively correlated with water and phytoplankton Cd concentrations (n=41, r=.3211, P≤.0407 and r=.7667, P≤.0001) while Cu levels were not correlated with any of the variables tested. The difference between the correlatedness of Cd levels in zooplankton to water and phytoplankton Cd levels compared to the lack of this type of relationship with regard to Cu may be attributable to the biological function of each metal in zooplankton. Cu is required in small amounts for physiological processes and may be regulated whereas Cd has no known biological function. / Thesis / Master of Science (MS)

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Thesis (M.S.)--University of Delaware, 2008. / Principal faculty advisor: Robert W. Birkmire, Dept. of Materials Science & Engineering. Includes bibliographical references.

Mémoire (M.Ress.Renouv.)-- Université du Québec à Chicoutimi, 1993. / Document électronique également accessible en format PDF. CaQCU

Thesis (M.Sc.)--City University of Hong Kong, 2005. / At head of title: City University of Hong Kong, Department of Physics and Materials Science, Master of Science in materials engineering & nanotechnology dissertation. On t.p. the "x" of "CdxZn₁-xS" are subscript. Title from title screen (viewed on Sept. 4, 2006) Includes bibliographical references.

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The aim of this study was to understand the properties of glass/TCO/CdS/CdTe/metal solar cells, the CdS and CdTe being grown by aqueous electrodeposition. Deposited films and completed cells were characterised using electrical, structural and optical techniques. This report describes the production of well-formed polycrystalline CdS and CdTe with well defined XRD peaks and band gap. Experiments were performed to investigate the pre-conditioning of the CdTe bath on the overall cell performance. Pre-conditioning the CdTe deposition bath was found to improve the Voc value of the completed devices. It has been known for some time that treating the CdTe layer of a CdS/CdTe solar cell with chlorine brings about significant improvements in the efficiency of these devices. This report presents results on a systematic variation of the chlorine concentration within a CdTe deposition bath. Solar simulated I-V measurements of completed devices clearly show that the addition of CdCl[2] to the CdTe deposition bath significantly improved the efficiency values for the glass/TCO/CdS/CdTe/metal devices. The electrical parameter most significantly affected by the addition of chlorine is the J[sc] value. In terms of the Voc performance of the device, this investigation showed that there was a trend of improving Voc with increasing chlorine concentration. Addition of chlorine also produces improvements in the preferred orientation of CdTe films as measured by XRD. Optical absorption results showed a correlation that the minima of the band gap vs. chlorine concentration graph for annealed samples matches up with the maximum in the efficiency and J[sc] graphs. To investigate whether this phenomenon was specific to chlorine or was displayed by other elements, similar experiments were performed with no chlorine inclusion but varying the indium concentration in the deposition bath. Solar simulated I-V measurements of completed devices clearly show that the addition of In[2](SO[4])[3] to the CdTe deposition bath significantly reduced the efficiency values for the glass/TCO/CdS/CdTe/metal devices. The electrical parameter most significantly affected by the addition of indium is the J[sc] value. The addition of indium also had a detrimental effect on the preferred orientation measured by XRD.