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The Influence of a Fluctuating Water Table on Arsenic Mobility in a Western U.S. AquiferAbu-Ramaileh, Allia Maher 01 May 2015 (has links)
Arsenic (As) concentrations in groundwater that exceed the Maximum Contaminant Level (MCL) (10 μg/L) for drinking water have been reported throughout the United States, with higher occurrences in the Southwestern basin-fill aquifers. Levels of As above the MCL were measured in wells throughout the Cache Valley Basin, Utah. The As is naturally occurring in geologic material from the soil surface to depths of groundwater. This study reports on the mechanisms of retention and solubilization of As through these zones using geochemical modeling and microcosm studies.
Two cores (NP 9 and NP 13) were collected from the soil surface to the depth of groundwater and sectioned based on observed redoximorphic features. Pore water was analyzed for As and iron( Fe) redox species, general water quality parameters and solid phase As, Fe and Mn using sequential extractions. These data were used in PHREEQC and MINTEQ geochemical models to predict mechanisms of As retention. Microcosm studies were performed using sediments from the water table zone. The sediments were exposed to oxidized, reduced, and poisoned conditions over time to evaluate the effect of the seasonal fluctuating water table on As release.
Modeling results indicated As(V) was dominantly sorbed to hydrous ferric oxides (HFO) throughout both profiles. Although much less As(V) was sorbed to CaCO3, the percentage associated with calcite was 1.7 to 3.3% and 6 to 59% in the surface and water table zones for NP 9 and NP 13, respectively. As(III) solubility was controlled by the formation of an As-S mineral, orpiment.
Microcosm findings, over 113-day incubation, concluded that regardless of treatment condition, As is released. For reduced samples As in solution was primarily As(III), while oxidized and poisoned samples only released As(V). The release of As under every condition, and the lack of reduced As and Fe in the poisoned samples, indicates that As release is abiotically controlled, while reduction is microbially driven. Carbonate minerals were the source of As(V) under treatment conditions as determined using an acetate extraction. Desorption of As(V) from carbonate minerals and the reduction of As(V) to As(III) played a significant role in explaining solution phase As(III) concentrations.
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Variations in Phenotypic Plasticity and Fluctuating Asymmetry of Leaf Morphology of Three Quercus (Oak) Species in Response to Environmental FactorsKusi, Joseph 01 May 2013 (has links) (PDF)
Leaf morphology of Quercus (oak) species is highly variable and complicated confounded with phenotypic plasticity and fluctuating asymmetry (FA). However, the study of variation is mostly limited to leaf morphology. This study was extended to plasticity and FA variations in Q. alba (white oak), Q. palustris (pin oak), and Q. velutina (black oak). It was hypothesized that light exposure, individual trees, leaf position, and other leaf traits will influence variation in these species. Leaves were sampled from trees of these species and their morphological traits were measured. Absolute asymmetry of leaf width and area were determined and plasticity of each species was calculated. The data were analyzed using nested ANOVA with General Linear Model. Leaf morphology, plasticity and FA varied across the species and light exposure was the main source of variation. Individual trees and several leaf covariate traits also influenced leaf morphological and FA variations in all species.
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Fluctuating Asymmetry and Its Relationship to Established Indicators of Environmental Stress.Shotwell, Matthew Stephen 06 May 2006 (has links) (PDF)
Fluctuating asymmetry (FA) is commonly thought to be a predictor of environmental stress. However, the relationship between FA and established indicators for environmental stress has received little attention. In this study, 10-38 specimens of the freshwater fish Rhinichthys atratulus were collected from 15 natural populations under varying amounts of environmental stress. Asymmetry measurements in three bilateral characters of the specimens were used to investigate the relationship between FA and established indicators of environmental stress. Significant differences in the magnitude of FA were observed between sampling locations. However, the relationship between estimates of FA and established indicators produced varying results. The present study concludes with a discussion on the usefulness of FA as a bioindicator for environmental stress and implications for future studies.
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Human skeletal asymmetry. A study of directional and fluctuating asymmetry in assessing health, environmental conditions, and social status in English populations from the 7th to the 19th centuries.Storm, Rebecca A. January 2009 (has links)
Volume 1 = Thesis, Volume 2 = Appendices / Asymmetry is a useful tool for osteological analysis as it detects disruptions in the developmental stability of osseous structures attributed to environmental and biomechanical environments. The primary aim of this study is to establish a baseline for normal levels of asymmetry in English archaeological populations in order to distinguish between normal population variation and increased developmental instability or biomechanical stress. Directional and fluctuating asymmetry is assessed through a database of a comprehensive selection of osteological measurements throughout the skeletons of 1753 adults and subadults. The sample is from 11 archaeological sites spanning the Anglo-Saxon to the Victorian periods. The extent of developmental instability is also determined, for the first time, by employing the prevalence of population outliers. The normal range for directional asymmetry was found to be -5.79 to 6.62%, while fluctuating asymmetry was found to be 0 to 6.53%. The extent of asymmetry, however, was found to be trait specific. Deviations from normal population levels of asymmetry were found to be due to a complex mixture of biomechanical and environmental stresses influenced by age, sex, settlement type, socio-economic status, and period-specific origins of the sample populations. Possible causes of asymmetry could be discerned from comparisons of the levels of population asymmetry when placed in the context of physical activity, social networking, health, and environment developed from the historical, archaeological and osteological record. / Andy Jagger Fund and the Francis Raymond Hudson Memorial Fund
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Thermal, morpholine, and radiation stressor effects on the embryonic development of lake whitefish (Coregonus clupeaformis) and round whitefish (Prosopium cylindraceum) / Environmental stressor effects on whitefish embryogenesisLim, Michael January 2016 (has links)
Lake and round whitefish are cold-adapted freshwater species with similar life
histories and spawning behaviours. There have been several studies on the embryonic
development of both species (particularly for lake whitefish), most utilizing constant
temperatures. However, temperatures fluctuate in the field due to natural (e.g. seasonal
changes) and anthropogenic (e.g. water discharged from once-through cooling processes)
effects. Releases from once-through cooling processes may contain low levels of
chemicals (e.g. morpholine) and radiation (e.g. tritium). This thesis examined and
compared the impacts of thermal, morpholine, and radiation stressors on lake and round
whitefish embryogenesis.
To examine the effects of fluctuating incubation temperatures, lake and round
whitefish were reared at constant temperatures, with seasonal temperature
declines/inclines, transient temperature spikes, or seasonal temperature changes combined
with temperature spikes. Round whitefish embryos had significantly higher mortality
when reared at 8°C compared to lake whitefish, and seasonal temperature changes
impacted development rate, growth, and hatch dynamics for both species. Temperature
spikes had relatively little effect on development.
The effects on embryonic development of chronic morpholine and low-dose
radiation exposures were examined in round whitefish to compare with existing data in
lake whitefish. Round whitefish embryos were more impacted by morpholine than lake
whitefish (larger effects on growth and mortality at relatively lower concentrations) and
v
less impacted by low-dose radiation (little effect on growth or hatch dynamics). Post
hatch, round whitefish embryos reared at 8°C, with rapid seasonal inclines, or with 500
mg L-1 morpholine had elevated mortality. All irradiated embryos had decreased mortality
post-hatch compared to non-irradiated embryos. Thus, embryonic exposure to all stressors
examined appears to alter post-hatch survival.
This thesis better defines the effects of fluctuating incubation temperatures,
chronic morpholine, and chronic radiation exposures on the embryonic development of
lake and round whitefish. It also suggests that embryonic incubation conditions are
important beyond hatching. / Thesis / Master of Science (MSc) / Lake and round whitefish are cold-adapted freshwater species. Both species
play important ecological roles, with lake whitefish generally perceived as more
economically and culturally important. Many studies have detailed lake whitefish
embryonic development under constant stressors (e.g. temperature) but there are
relatively few studies on round whitefish embryonic development. Both species
experience seasonal temperature fluctuations in nature and may experience
additional anthropogenic temperature, chemical, and radiation stress due to
discharge from once-through cooling processes at thermal power plants, which may
contain low levels of morpholine and radiation. Our study suggests that round
whitefish embryos are more sensitive to elevated temperature and morpholine
levels, but less impacted by chronic low-dose irradiation relative to lake whitefish
embryos. The growth and development of both species are significantly affected by
seasonal temperature changes.
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The effect of resource availability on community dynamics and properties in experimental microcosmsLi, Wei 11 August 2008 (has links)
No description available.
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Fluctuating dental asymmetry as an indicator of stress in prehistoric native Americans of the Ohio River ValleyBarrett, Christopher K. 13 July 2005 (has links)
No description available.
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Assimetria humana no reconhecimento multibiométrico. / Human asymmetry in multibiometric recognition.Vertamatti, Rodolfo 13 October 2011 (has links)
A combinação de fontes biométricas não redundantes da multibiometria supera a precisão de cada fonte individual (monobiometria). Além do mais, dois problemas em biometria, ruído e ataques de usurpadores, podem ser minimizados pelo uso de múltiplos sensores e biometria multimodal. Entretanto, se as similaridades estão em todos traços biométricos, como em gêmeos monozigotos (MZ), o processamento de múltiplas fontes não melhora a performance. Para distinguir extrema similitude, influências epigenéticas e ambientais são mais importantes do que o DNA herdado. Esta tese examina a plasticidade fenotípica na assimetria humana como uma ferramenta para melhorar a multibiometria. A técnica de Processamento Bilateral (PB) é introduzida para analisar discordâncias em lados esquerdo e direito dos traços biométricos. PB foi testado com imagens de espectro visível e infravermelho usando Correlação Cruzada, Wavelets e Redes Neurais Artificiais. Os traços selecionados foram dentes, orelhas, íris, impressões digitais, narinas e bochechas. PB acústico também foi implementado para avaliação da assimetria vibracional durante sons vocálicos e comparado a um sistema reconhecedor de locutores com parametrização via MFCC (Mel Frequency Cepstral Coefficients) e classificado por Quantização Vetorial. Para o PB de imagens e acústico foram coletadas 20 amostras por traço biométrico durante um ano de nove irmãos masculinos adultos. Com propósito de teste, as biometrias esquerdas foram impostoras às biometrias direitas do mesmo indivíduo e vice-versa, o que levou a 18 entidades serem identificadas por traço biométrico. Resultados alcançaram identificação total em todas biometrias tratadas com PB, comparado a um máximo de 44% de identificação correta sem PB. Esta tese conclui que peculiaridades bilaterais melhoram a performance multibiométrica e podem complementar qualquer abordagem de reconhecimento. / Combination of non-redundant biometric sources in multibiometrics overcomes individual source accuracy (monobiometrics). Moreover, two problems in biometrics, noise and impostor attacks, can be minimized by the use of multi-sensor, multi-modal biometrics. However, if similarities are in all traits, as in monozygotic twins (MZ), multiple source processing does not improve performance. To distinguish extreme similitude, epigenetic and environmental influences are more important than DNA inherited. This thesis examines phenotypic plasticity in human asymmetry as a tool to ameliorate multibiometrics. Bilateral Processing (BP) technique is introduced to analyze discordances in left and right trait sides. BP was tested in visible and infrared spectrum images using Cross-Correlation, Wavelets and Artificial Neural Networks. Selected traits were teeth, ears, irises, fingerprints, nostrils and cheeks. Acoustic BP was also implemented for vibration asymmetry evaluation during voiced sounds and compared to a speaker recognition system parameterized via MFCC (Mel Frequency Cepstral Coefficients) and classified by Vector Quantization. Image and acoustic BP gathered 20 samples per biometric trait during one year from nine adult male brothers. For test purposes, left biometrics was impostor to right biometrics from the same individual and vice-versa, which led to 18 entities to be identified per trait. Results achieved total identification in all biometrics treated with BP, compared to maximum 44% of correct identification without BP. This study concludes that bilateral peculiarities improve multibiometric performance and can complement any recognition approach.
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Using CHP plant to regulate wind powerElzubair, Arwa January 2019 (has links)
Sweden is working on increasing the share of wind energy, but it comes along with many challenges,one of those challenges is the uncertainty of the wind power; CHP could be an option for betterutilizing of wind power by adapting the power to heat ratio according to wind energy fluctuation.The potential for utilizing installed wind energy in Sweden using CHP plant has been studied. A CHPplant installed in the South of Sweden was considered as studied case. To match the heat andelectricity demand requested by the region with the output from the CHP plant two scenarios weresimulated. Results showed that 5.3 MW of installed wind energy in Sweden could be adjusted andset to a level of 73.6 MW if the CHP plant alone were to cover the heat demand, and 25.4 MW ofinstalled wind power in Sweden could be adjusted and set to a level of 54.2 MW with an additionalheat supply of 8 MW in the studied case.
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Assimetria humana no reconhecimento multibiométrico. / Human asymmetry in multibiometric recognition.Rodolfo Vertamatti 13 October 2011 (has links)
A combinação de fontes biométricas não redundantes da multibiometria supera a precisão de cada fonte individual (monobiometria). Além do mais, dois problemas em biometria, ruído e ataques de usurpadores, podem ser minimizados pelo uso de múltiplos sensores e biometria multimodal. Entretanto, se as similaridades estão em todos traços biométricos, como em gêmeos monozigotos (MZ), o processamento de múltiplas fontes não melhora a performance. Para distinguir extrema similitude, influências epigenéticas e ambientais são mais importantes do que o DNA herdado. Esta tese examina a plasticidade fenotípica na assimetria humana como uma ferramenta para melhorar a multibiometria. A técnica de Processamento Bilateral (PB) é introduzida para analisar discordâncias em lados esquerdo e direito dos traços biométricos. PB foi testado com imagens de espectro visível e infravermelho usando Correlação Cruzada, Wavelets e Redes Neurais Artificiais. Os traços selecionados foram dentes, orelhas, íris, impressões digitais, narinas e bochechas. PB acústico também foi implementado para avaliação da assimetria vibracional durante sons vocálicos e comparado a um sistema reconhecedor de locutores com parametrização via MFCC (Mel Frequency Cepstral Coefficients) e classificado por Quantização Vetorial. Para o PB de imagens e acústico foram coletadas 20 amostras por traço biométrico durante um ano de nove irmãos masculinos adultos. Com propósito de teste, as biometrias esquerdas foram impostoras às biometrias direitas do mesmo indivíduo e vice-versa, o que levou a 18 entidades serem identificadas por traço biométrico. Resultados alcançaram identificação total em todas biometrias tratadas com PB, comparado a um máximo de 44% de identificação correta sem PB. Esta tese conclui que peculiaridades bilaterais melhoram a performance multibiométrica e podem complementar qualquer abordagem de reconhecimento. / Combination of non-redundant biometric sources in multibiometrics overcomes individual source accuracy (monobiometrics). Moreover, two problems in biometrics, noise and impostor attacks, can be minimized by the use of multi-sensor, multi-modal biometrics. However, if similarities are in all traits, as in monozygotic twins (MZ), multiple source processing does not improve performance. To distinguish extreme similitude, epigenetic and environmental influences are more important than DNA inherited. This thesis examines phenotypic plasticity in human asymmetry as a tool to ameliorate multibiometrics. Bilateral Processing (BP) technique is introduced to analyze discordances in left and right trait sides. BP was tested in visible and infrared spectrum images using Cross-Correlation, Wavelets and Artificial Neural Networks. Selected traits were teeth, ears, irises, fingerprints, nostrils and cheeks. Acoustic BP was also implemented for vibration asymmetry evaluation during voiced sounds and compared to a speaker recognition system parameterized via MFCC (Mel Frequency Cepstral Coefficients) and classified by Vector Quantization. Image and acoustic BP gathered 20 samples per biometric trait during one year from nine adult male brothers. For test purposes, left biometrics was impostor to right biometrics from the same individual and vice-versa, which led to 18 entities to be identified per trait. Results achieved total identification in all biometrics treated with BP, compared to maximum 44% of correct identification without BP. This study concludes that bilateral peculiarities improve multibiometric performance and can complement any recognition approach.
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