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Articles 1 - 7 of 7
Full-Text Articles in Life Sciences
Diatom Community Responses To Development And Climate Change In Lake George, An Oligotrophic Lake In The Adirondack Mountains, Adam T. Ruka
Diatom Community Responses To Development And Climate Change In Lake George, An Oligotrophic Lake In The Adirondack Mountains, Adam T. Ruka
Masters Theses
Lake George is a highly monitored, oligotrophic lake that experiences widespread tourism in the summer months. The southern basin is more developed than the northern basin, suggesting a north-south gradient of anthropogenic impairment. This study aimed to assess differences in nearshore diatom communities regarding gradients of water chemistry and watershed development throughout the lake. Using Redundancy analyses, water chemistry was found to explain more variation within diatom assemblages than watershed variables. Weighted averaging optima and tolerances specified taxa of concern, F. gracilis and A. formosa, that indicate increased phosphorus (μg/L) and conductivity (μS/cm), respectively. Two hypotheses related to the effect …
Lanthanide-Doped Ceria Nanoparticles As Backside Coaters To Improve Silicon Solar Cell Efficiency, Ali Hajjiah, Effat Samir, Nader Shehata, Mohamed Salah
Lanthanide-Doped Ceria Nanoparticles As Backside Coaters To Improve Silicon Solar Cell Efficiency, Ali Hajjiah, Effat Samir, Nader Shehata, Mohamed Salah
Biology Faculty Publications
This paper introduces lanthanide-doped ceria nanoparticles as silicon solar cell back-side coaters, showing their influence on the solar cell efficiency. Ceria nanoparticles can be synthesized to have formed oxygen vacancies (O-vacancies), which are associated with converting cerium ions from the Ce4+ state ions to the Ce3+ ones. These O-vacancies follow the rule of improving silicon solar cell conductivity through a hopping mechanism. Besides, under near-ultra violet (near-UV) excitation, the reduced trivalent cerium Ce3+ ions are directly responsible for down converting the un-absorbed UV wavelengths to a resultant green photo-luminescence emission at ~520 nm, which is absorbed through …
Diet Composition Explains Reductions In Stream Salamander Occupancy And Abundance Along A Conductivity Gradient, Jacob Matthew Hutton
Diet Composition Explains Reductions In Stream Salamander Occupancy And Abundance Along A Conductivity Gradient, Jacob Matthew Hutton
Theses and Dissertations--Forestry and Natural Resources
Changes in land use such as mountaintop removal mining with valley fills (MTR/VF) affect chemical, physical, and hydrological properties of headwater streams. Although numerous stream taxa have experienced significant declines from MTR/VF, stream salamanders appear to be particularly sensitive. Yet, the specific mechanism(s) responsible for the population declines has eluded researchers. We sampled salamander assemblages across a continuous specific conductivity (SC) gradient in southeastern Kentucky and estimated occupancy rates and abundance estimates along this gradient. We also examined the diet of larval and adult salamanders to determine if autochthony (A/T prey), total prey volume, and body condition is influenced by …
Effects Of Conductivity And Fish Grazing On Alkaline Phosphatase Activity Of Littoral Periphyton, Samuel A. Drerup
Effects Of Conductivity And Fish Grazing On Alkaline Phosphatase Activity Of Littoral Periphyton, Samuel A. Drerup
Browse all Theses and Dissertations
Littoral periphyton plays an important role in whole lake primary production and is a substantial contributor to whole lake energy budgets in moderately deep oligotrophic lakes. Under conditions of nutrient deficiency, members of the periphyton community supplement the available nutrient pool through the production of intracellular and extracellular enzymes. These enzymes are used to convert bio-unavailable forms of nitrogen and phosphorous to forms usable by the periphyton community. In this paper, I will investigate how conductivity and fish grazing affect periphyton production and phosphorus acquisition in both field and laboratory experiments.
Microbial Growth And Biofilm Formation In Geologic Media Is Detected With Complex Conductivity Measurements, Caroline A. Davis, Estella A. Atekwana, Eliot A. Atekwana, Lee D. Slater, Silvia Rossbach, Melanie R. Mormile
Microbial Growth And Biofilm Formation In Geologic Media Is Detected With Complex Conductivity Measurements, Caroline A. Davis, Estella A. Atekwana, Eliot A. Atekwana, Lee D. Slater, Silvia Rossbach, Melanie R. Mormile
Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works
Complex conductivity measurements (0.1-1000 Hz) were obtained from biostimulated sand-packed columns to investigate the effect of microbial growth and biofilm formation on the electrical properties of porous media. Microbial growth was verified by direct microbial counts, pH measurements, and environmental scanning electron microscope imaging. Peaks in imaginary (interfacial) conductivity in the biostimulated columns were coincident with peaks in the microbial cell concentrations extracted from sands. However, the real conductivity component showed no discernible relationship to microbial cell concentration. We suggest that the observed dynamic changes in the imaginary conductivity (σ″) arise from the growth and attachment of microbial cells and …
Bias Dependence Of The Depletion Layer Width In Semi-Insulating Gaas By Charge Collection Scanning Microscopy, A. Castaldini, A. Cavallini, C. Del Papa, M. Alietti, C. Canali, F. Nava, C. Lanzieri
Bias Dependence Of The Depletion Layer Width In Semi-Insulating Gaas By Charge Collection Scanning Microscopy, A. Castaldini, A. Cavallini, C. Del Papa, M. Alietti, C. Canali, F. Nava, C. Lanzieri
Scanning Microscopy
A procedure for the evaluation of the depletion region width of a Schottky barrier diode made on semi-insulating materials has been assessed and applied to gallium arsenide nuclear detectors. This procedure, which makes use of the optical beam induced current method of charge collection scanning microscopy, allows the direct measurement of the depletion layer width. By taking into account the high resistivity of the material under examination and measuring the diode reverse current, it is possible to evaluate the actual voltage applied at the depletion layer boundaries. It was found that, at low actual bias values, the voltage dependence of …
Limnological Monitoring Data For Lake Mead During 1988, Suzanne E. Leavitt, Larry J. Paulson, State Of Nevada: Division Of Environmental Protection
Limnological Monitoring Data For Lake Mead During 1988, Suzanne E. Leavitt, Larry J. Paulson, State Of Nevada: Division Of Environmental Protection
Publications (WR)
Limnological monitoring was conducted in Las Vegas Bay and Boulder Basin from April to December of 1988. The purpose of the monitoring was to (i) document possible changes in water quality resulting from decreased phosphorus loading and increased ammonia in Las Vegas Wash, and (ii) establish a data base for evaluating the adequacy of water quality standards.