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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
281

The Land Still Speaks: Traditional Cultural Property Eligibility Statements for Gold Strike Canyon, Nevada and Sugarloaf Mountain, Arizona

Stoffle, Richard W., Carroll, Alex, Toupal, Rebecca, Zedeno, Maria Nieves, Eisenberg, Amy, Amato, John January 2000 (has links)
As part of the American Indian consultation process for the Hoover Dam Bypass Project the Federal Highway Administration (FHWA) consults regularly with representatives of tribal groups that have an interest in cultural and traditional resources affected by the project plans and activities. The focus of this document is on information particular to understanding cultural landscapes and the long standing connections between the Southern Paiutes, Hualapais, and Mohaves and the revered sites of Sugarloaf Mountain and Goldstrike. In the end, these layered intertribal and geographic connections which link these sites met the criteria for establishing the eligibility of Sugarloaf Mountain and Gold Strike Canyon as Traditional Cultural Properties (TCPs). This report was prepared as part of the nomination process. Maps containing locations have been redacted from the public document. Tribal members who want a copy of the un-redacted report please contact Special Collections. Sugarloaf Mountain and Goldstrike Canyon officially were designated TCPs on September 4, 2004.
282

Numerical Modeling of Tsunami-induced Hydrodynamic Forces on Free-standing Structures Using the SPH Method

St-Germain, Philippe 23 November 2012 (has links)
Tsunamis are among the most terrifying and complex physical phenomena potentially affecting almost all coastal regions of the Earth. Tsunami waves propagate in the ocean over thousands of kilometres away from their generating source at considerable speeds. Among several other tsunamis that occurred during the past decade, the 2004 Indian Ocean Tsunami and the 2011 Tohoku Tsunami in Japan, considered to be the deadliest and costliest natural disasters in the history of mankind, respectively, have hit wide stretches of densely populated coastal areas. During these major events, severe destruction of inland structures resulted from the action of extreme hydrodynamic forces induced by tsunami flooding. Subsequent field surveys in which researchers from the University of Ottawa participated ultimately revealed that, in contrast to seismic forces, such hydrodynamic forces are not taken into proper consideration when designing buildings for tsunami prone areas. In view of these limitations, a novel interdisciplinary hydraulic-structural engineering research program was initiated at the University of Ottawa, in cooperation with the Canadian Hydraulic Centre of the National Research Council, to help develop guidelines for the sound design of nearshore structures located in such areas. The present study aims to simulate the physical laboratory experiments performed within the aforementioned research program using a single-phase three-dimensional weakly compressible Smoothed Particle Hydrodynamics (SPH) numerical model. These experiments consist in the violent impact of rapidly advancing tsunami-like hydraulic bores with individual slender structural elements. Such bores are emulated based on the classic dam-break problem. The quantitatively compared measurements include the time-history of the net base horizontal force and of the pressure distribution acting on columns of square and circular cross-sections, as well as flow characteristics such as bore-front velocity and water surface elevation. Good agreement was obtained. Results show that the magnitude and duration of the impulsive force at initial bore impact depend on the degree of entrapped air in the bore-front. The latter was found to increase considerably if the bed of the experimental flume is covered with a thin water layer of even just a few millimetres. In order to avoid large fluctuations in the pressure field and to obtain accurate simulations of the hydrodynamic forces, a Riemann solver-based formulation of the SPH method is utilized. However, this formulation induces excessive numerical diffusion, as sudden and large water surface deformations, such as splashing at initial bore impact, are less accurately reproduced. To investigate this particular issue, the small-scale physical experiment of Kleefsman et al. (2005) is also considered and modeled. Lastly, taking full advantage of the validated numerical model to better understand the underlying flow dynamics, the influence of the experimental test geometry and of the bed condition (i.e. dry vs. wet) is investigated. Numerical results show that when a bore propagates over a wet bed, its front is both deeper and steeper and it also has a lower velocity compared to when it propagates over a dry bed. These differences significantly affect the pressure distributions and resulting hydrodynamic forces acting on impacted structures.
283

Agriculture, Dams, and Weather

Mirghasemi, Seyedeh Soudeh January 2015 (has links)
The first chapter investigates whether construction of the Bureau of Reclamation dams in the early twentieth century raise farm values and increase agricultural output? I construct a new county level panel data set from 1890 to 1920 with information on geography, climate, politics, agriculture, and major dams and then evaluate the effect of the Bureau of Reclamation dams on the value of farms and on crop productivity. Using fixed effect panel estimation, I find that new federal dam construction increased the average value of farm land by approximately 6.4 percent. When I apply an instrument to control for potential endogeneity, the effect of Bureau dams on the farm land value increases in size, although the estimate is no longer statistically significant. When examining the crop output, the only crop for which the dams had effects was alfalfa. In the second chapter I investigate the effect of the geographic, economic and political factors on dam construction at the beginning of the Bureau of Reclamation's operation in the American West. Applying county level data which has been linked from various data sources for the time period of 1900 to 1910, I show that the percentage of votes for Republicans in presidential elections has a significant and positive effect on major dam construction. The last chapter investigates the effect of climate change on US agriculture using county-level data from 1997 to 2007. Compared to previous contributions, we pay particular attention to the spatial heterogeneity across the climate zones and include the presence of extreme weather events. The lack of consideration for both effects may have led previous works to generate biased estimates and incorrect impact forecasts. While current approaches use projected climate variables derived from coarse resolution Global Climate Models (GCMs), we use data at a much finer resolution by relying on dynamically downscaled simulation data. Further, we pay particular attention to the spatial heterogeneity in the impact of climate among the climate zones. Chow-Wald tests indicate the presence of significant heterogeneity across zones in the effects of climate on land values.
284

Stability Analysis of Earth Dams and Dikes under the Influence of Precipitation and Vegetation

Guo, Jinxing 07 March 2016 (has links) (PDF)
An earth dam and a dike is one kind of hydraulic construction, which is built with highly compacted earth and can be used for the purpose of containing water in a reservoir to secure the water supply, and in flood control. Earth dam and dike can be a safety issue, as it can experience catastrophic destruction due to the slope failure caused by various factors, such as construction materials, vegetation, atmospheric conditions and so on. The aim of this study is to investigate the influence of the saturation degree (or water content) on the stability of earth dam and dikes under the consideration of precipitation and vegetation with the program PCSiWaPro® (developed at the Technical University of Dresden, Institute of Waste Management and Contaminated Site Treatment). The preliminary tests on a physical model have shown that the security and stability has been already severely compromised in the partially saturated region, i.e. the area above the seepage line was in great danger and it came quickly to landslides on the air side. Before the stability analysis could be done for those unsaturated zones, water flow processes and water saturation in the saturated and partially saturated soil area were simulated using the simulation program PCSiWaPro® under transient boundary conditions. The integration of a weather generator into PCSiWaPro® allows a transient water flow calculation with respect to atmospheric conditions (precipitation, evaporation, daily mean temperature and sunshine duration) and removal of water by plant roots and leaves. Finally, with the Program PCSiWaPro® and Gmsh, a 2D dynamic model of water content distribution in the earth dam could be built, incorporating information of not only climate parameters and vegetation but also geometry, soil properties, geohydraulic conditions and time-dependent boundary conditions. The simulation results of several scenarios both in the laboratory and in the field of China and Germany clearly demonstrated that the accordance between measured values and calculated values for water content using the simulation program PCSiWaPro® was very good. In addition, two kinds of stability analysis models (the Infinite Slope Model and the BISHOP’S Model, one kind of the limit equilibrium method), which were both developed from the old Mohr-Coulomb Model, have been improved with the additional consideration of root reinforcement in the upper layer of the slope and soil water in the earth slope. The Infinite Slope Model has been proved to be mainly applied for the surficial landslide; while the BISHOP’S Model is more responsible for the deeper slip landslide forecasting. Then based on the PCSiWaPro® simulation result of water content in the unsaturated slope in the earth bodies from two study sites, Fs (safety of factor) calculation for those earth slopes was derived providing a sufficient forecasting system for the slope-failure-flood. The results have been compared with the calculated Fs values from the old models (without consideration of the influence of water content change on the slope stability) to study how significantly water content increased the risk of slope landslides.
285

Sambandet mellan sprinttester i löpning på barmark och skridsko på is : En korrelationsstudie gjord på svenska damhockeyspelare

Rudner, Maria, Höglund, Rebecca January 2017 (has links)
Sammanfattning Syfte och frågeställningar Syftet är att undersöka om det föreligger något samband mellan 1RM i benböj och sprintlöpning på is kontra sambandet mellan sprintlöpning på barmark och 1RM i benböj för svenska damhockeyspelare i högsta serien SDHL. Finns det något samband mellan maxstyrka i 1RM i benböj och sprinter på barmark (utanför isen) hos svenska damhockeyspelare? Finns det något samband mellan maxstyrka i 1RM benböj och sprinter på is hos svenska damhockeyspelare? Finns det något samband mellan sprintlöpning på barmark och skridskosprinter på is? Metod Testerna utfördes vi två tillfällen med en veckas mellanrum. Vid första tillfället utfördes testerna i benböj ned till ett djup där lårbenet var parallellt med underlaget. Startvikten var 70% av den förväntade maxvikten och testpersonen hade två försök på varje vikt. Vid andra tillfället utfördes 30 meter sprint på barmark och på is och där fotoceller användes för mätning av tid (Time-it - basic set, ELEIKO). Fotocellsparen placerades på ställningar med en höjd på 91cm från underlaget med 1,5 meter avstånd från varandra och testpersonerna startade 0,5 meter innan första fotocellerna och fick välja själva när de skulle starta. Testpersonerna utförde två sprinter vardera på barmark respektive is där det bästa resultatet sedan användes i analysen. Samtliga analyser genomfördes i programmet SPSS. Resultat Studien resulterade i medelhöga negativa korrelationskoefficienter erhölls mellan variablerna 1RM i benböj och 30 meter barmarkssprint (r= -0,548). Ett svagt positivt samband hittades mellan variablerna 1RM och sprint på is (r = 0,164). Det fanns signifikanta skillnader mellan de två variablerna och med 95 procent säkerhet skiljer sig minst ett av medelvärdena ifrån de andra på ett sätt som inte beror på slumpen. På T-testet var Sig.värdet 0,000 på samtliga parametrar samt differensen i medelvärdet översteg 0,050 vilket gör att det inte går att dra någon slutsats över en större population. Slutsats Med vår studie kunde vi se ett starkare samband mellan testpersonernas prestation i sprinten på barmark och ett maximalt lyft i benböj (r = -0,548) än vad vi kunde se mellan resultaten i sprint på is och benböjen (r = 0,164) / <p>Ämneslärarprogrammet, Specialidrott</p>
286

Americký klub dam a učitelky / American lady club and teachers

Krajčová, Lenka January 2012 (has links)
The aim of this thesis is to describe American Lady Club, its origin, development and activities. A particular importace is placed on description of significant members of this club who devoted themselves to educational activity. For a comprehensive view the possibilities of education of women are mentioned as well as some of the other important female clubs.
287

Histopathological assessment of selected organs as a bio-monitoring tool to assess the health status of Clarias gariepinus in two dams in the Rietvlei Nature Reserve

15 August 2008 (has links)
Water resources are frequently under inspection as pollution increases. Therefore an urgent need has arisen for sensitive bio-monitoring tools in toxicant impact assessment to indicate the effect of pollution on fish health in polluted aquatic ecosystems. Histopathological assessment of fish tissue allows for early warning signs of disease and detection of long term injury in cells, tissues or organs. Various biochemical and biological studies of fish have been used to assess the consequences of environmental toxicants on fish, but histology is able to enhance and add quality to the research carried out by identifying cellular alterations and quantifying the results. The aim of this study was to assess the degree of pollution in the Marais Dam (MD) and Rietvlei Dam (RVD) in the Rietvlei Nature Reserve (RNR) by determining the health status of the sharptooth catfish, Clarias gariepinus, using fish histology as a bio-monitoring tool.The MD and RVD situated within the Sesmyl Spruit serve to provide the area with water and are separated by a natural wetland. The dams were chosen for their elevated levels of toxicants. Four sampling surveys, two low flow and two high flow, were carried out over a period of two years. During each survey twenty fish were sampled per dam. Water and sediment were sampled for metal and endocrine disrupting chemical analysis. A standardized health assessment protocol employed to determine the effects of the toxicants included analysis of blood constituents, fish necropsy, calculation of condition factor and organosomatic indices, and a qualitative and quantitative histological assessment of three target organs: the gills, liver and gonads. These organs were removed and processed according to standard techniques for histological assessment. Histopathological alterations of each organ were identified (qualitative assessment) and subsequently quantified by means of a standard methodology of criteria to assess and compare fish health (quantitative assessment). The total index (Tot-I) values from the quantitative histological assessment were statistically analyzed using the ANOVA method. Potential endocrine disrupting chemicals and metals in the water of both dams were present at levels that could be toxic. The degree of pollution was more severe in MD than RVD. Examination of tissue from the gills, liver and gonads revealed marked histopathological alterations. The quantitative histological assessment indicated that fish collected from MD were in a significantly more severe histopathological condition than those of RVD. These results indicate that the wetland may still function as a natural filter. The qualitative and quantitative histological assessment objectively compared C. gariepinus specimens from MD and RVD and the effects of the toxicants on the health of the fish. / Dr. G.M. Pieterse
288

A histology-based fish health assessment to determine the health status and edibility of two indicator fish species from the Roodeplaat Dam

22 June 2011 (has links)
M.Sc. / A comprehensive histology-based fish health assessment was implemented at the Roodeplaat Dam (RD), Pretoria, South Africa, to determine the health status of two fresh water fish species, Clarias gariepinus (n = 20) and Oreochromis mossambicus (n = 18), after exposure to pollutants. RD is known to be polluted, being impacted from two sewage treatment plants, industry, housing and agriculture all upstream of the reserve. Excessive nutrient loads, such as orthophosphate, resulted in the dam becoming eutrophic. The quality of water in the RD was a cause for concern, as the fish from the dam are being used as a source of food by the local people. The histology-based fish health assessment included fish necropsy, calculation of gross body indices and histological assessment. Water quality (chemical and physical) analysis was also carried. Furthermore, target chemical analysis of fish tissue (skeletal muscle) was performed to determine the levels of contaminants in the consumable parts of the fish. These results were compared with existing international guidelines to determine whether the harvested fish were safe for human consumption. All the information obtained was integrated in a qualitative and quantitative scenario-based health risk assessment.
289

Evolution du fonctionnement sédimentologique et biogéochimique d'un bief de rivière suite à l'effacement d'ouvrages hydrauliques / Evolution of sedimentological and biogeochemical functioning of a river section after dams removal

Bellot, Cécile 11 July 2014 (has links)
L’Orge est une petite rivière de plaine fortement segmentée, du bassin parisien. En 2010, elle comptait en moyenne un clapet tous les kilomètres sur sa partie aval. Pour rétablir la continuité écologique du cours d’eau, le Syndicat de l’Orge efface progressivement ces ouvrages. L'objet de cette thèse est le suivi biogéochimique, hydro-sédimentaire et écologique d'un bief de l’Orge de 6 km où 3 clapets consécutifs ont été effacés.Les hauteurs d’eau dans la rivière ayant baissé, des bancs de vase ont été mis à l'air. Ces banquettes de sédiments subissent des séquences d’inondation/exondation au rythme des crues. Les transformations de l’azote et du soufre y sont particulièrement actives et dynamiques. Cependant, les faibles flux d’eau échangés (modélisation) limitent l’impact des banquettes sur la rivière. Des processus intenses de précipitation/solubilisation des sulfates, liés aux variations des niveaux d’eau, ont une importance non négligeable sur la dégradation de la matière organique et la production d’ammonium dans la banquette.La capacité de transport de sédiments de la rivière a fortement évolué suite aux effacements, ce qui se traduit par l’apparition d'une granulométrie plus grossière en fond de lit. Ont été évalué la nouvelle vitesse de transit des particules charriées et le temps nécessaire pour atteindre un nouvel équilibre du lit et des espèces biologiques qui y vivent. Les indicateurs biologiques montrent que les effacements améliorent l’habitabilité de la rivière.Ces suivis montrent l’impact positif des effacements de barrage sur une rivière de plaine, même si un suivi dans la durée reste nécessaire pour confirmer les évolutions mises en évidence. / Orge is a lowland river from Seine’s watershed, France. In 2010, Orge River was highly segmented with on average one dam (< 2m) every kilometer in downstream part. To restore the ecological continuity of the river, the “Syndicat de l’Orge” gradually removes these little dams. The purpose of this thesis is the monitoring of hydro-morphology, biogeochemistry and ecological of a section of 6 km of Orge where 3 consecutive dams have been removed in spring 2010.After the water level decrease, some previously drowned sediment deposits appear along the river bank. These sediment banks are frequently inundated by high flows. Nitrogen and sulfate processes are very intense onto these banks. However, a model shows that water fluxes limited biochemical impact of sediment banks on the river. Intense precipitation/solubilization sulfate processes, link with water level variations, have a significant importance on organic matter degradation and ammonium production in sediment banks.The sediment transport capacity of the river has changed significantly after dam removal. It results in an increase of the maximum transportable diameter of the river, leading to the appearance of a coarser bed in-situ. It was possible to evaluate the new transit speed of particles carried along and highlight the time required to reach a new equilibrium of the bed and the biological species that live there. Biological indicators show that removals enhanced the livability of the river.All these studies show the positives impacts of dam removal on a lowland river, even if a monitoring in time is still needed to confirm the first developments highlighted here.
290

Pěstování ovsa v praktických podmínkách zemědělského podniku / The oat growing in terms of selected agricultural company

ZIMMERMANNOVÁ, Zlata January 2019 (has links)
The aim of the dissertation thesis was to find out the influence of fungicide and increased amount of nitrogen on the yield components of oat. The dissertation is divided into a literary overview and the thesis as such. In 2018 a pilot research was made on the land of a farm located in the district of Tábor. Atego oat was grown in four variants there: a control variant, a variant fertilized by nitrogen (without the usage of fungicide), a variant comprising fungicide application (without nitrogen fertilization) and a variant including both nitrogen fertilization and fungicide application. The highest theoretical yield was registered in the variant which contained fungicide as well as nitrogen. Regarding the yield components of oat, the highest number of plants and panicles was registered in the variant fertilized by nitrogen (without the usage of fungicide); the highest number of stolons and the maximum weight of one thousand grains was measured in the variant including both nitrogen fertilization and fungicide application. Finally, the highest number of grains in a panicle was obtained from a control variant.

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