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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.
41

Zhodnocení personálních činností ve vybrané firmě / Evaluation of Personnel Activities in a chosen Company

Beranová, Olga January 2007 (has links)
is not available ...
42

Algal Succession and Nutrient Dynamics in Elephant Butte Reservoir

Nielsen, Eric J. 16 March 2005 (has links) (PDF)
A water quality model was created for Elephant Butte Reservoir, New Mexico to understand nutrient dynamics and algal response during a three year period. The model chosen for this study was CE-QUAL-W2 because of its proven ability to represent hydrodynamics and the ability to represent multiple algal groups. Elephant Butte has been subject to large algal blooms. This study examined the phosphorus loading into the reservoir to see if it could sustain the observed algal growth. Data showed that the amount of bioavailable phosphorus was more than enough to support large blooms. This study also was an initial attempt to model multiple groups of algae that will later be used in other water quality models built and maintained by the US Bureau of Reclamation. Four algal species were modeled; diatoms, dinoflagellates, cyanobacteria and greens. Research into literary values of kinetic parameters for multiple algal species was conducted and the results were compiled in this paper to assist future modeling efforts. Because Elephant Butte was often nitrogen-limited the calibration of algal growth was difficult. Algal growth was very sensitive to the adjustment of kinetic parameters for nitrogen half-saturation, light requirements, growth rates and temperature rate multipliers.
43

Developing Methods to Assess the Potential Effects of Global Climate Change on Deer Creek Reservoir Using Water Quality Modeling

Chilton, Reed Earl 16 March 2011 (has links) (PDF)
To evaluate the potential impacts of future climate change on a temperate reservoir, I used a calibrated water quality and hydrodynamic model validated using three years of data (2007-2009) from Deer Creek Reservoir (Utah). I evaluated the changes due to altered air temperatures, inflow rates, and nutrient loads that might occur under Global Climate Change (GCC). I developed methods to study GCC on reservoirs. I produced Average Water Temperature Plots, Stratification Plots, and Total Concentration Plots. Average Water Temperature Plots show the sensitivity of the water temperature to various parameters. Stratification Plots quantify stratification length and strength as well as ice-cover periods. Total Concentration Plots analyze the reservoir as a whole concerning water quality parameters. Increasing air temperature increased the water temperature, lengthened stratification time, increased stratification strength, decreased the ice-cover period, decreased the total algae concentration, decreased the flows, and caused peak nutrient concentrations to occur earlier. Decreasing flows caused increased water temperature, shorter stratification periods, weaker stratification, and increased nutrient concentrations. Increasing phosphate concentrations caused increases in total algae, dissolved oxygen, and phosphate concentrations. Variations in Nitrate-Nitrite concentrations did not influence the tested parameters. I found that the reservoir is only sensitive to these changes during the spring and summer. The tools which I developed were used to run the model scenarios, organize the data, and plot the results. They can be used on other reservoirs and for other water quality parameters.
44

Watershed Based Analysis for Water Quality Management within the Escatawpa River System

Kilpatrick, Gerrod Wayne 12 May 2001 (has links)
Assessment of water quality within the Escatawpa River system was accomplished utilizing the Better Assessment Science Integrating Point and Nonpoint Sources (BASINS 2.0) to develop the watershed model, and the CE-QUAL-W2 software to develop the estuary model. The watershed model was utilized to quantify both hydrodynamic and water quality (fecal coliforms) characteristics of the watershed for a simulation period spanning from 1990 through 1999. Herein, calibration and application results are presented for watershed and estuary simulations made in an uncoupled manner. The models were developed such that loose coupling of watershed and estuary models can be accomplished as a subsequent phase of this ongoing project. CE-QUAL-W2 model calibration was performed utilizing a set of site specific data acquired on the Escatawpa Estuary System during an intensive survey period of September 10-15, 1997. Dissolved oxygen levels in the system were closely examined, with regards to the impacts from point source discharges.
45

Hypolimnetic Oxygenation: Coupling Bubble-Plume and Reservoir Models

Singleton, Vickie L. 29 April 2008 (has links)
When properly designed, hypolimnetic aeration and oxygenation systems can replenish dissolved oxygen in water bodies while preserving stratification. A comprehensive literature review of design methods for the three primary devices was completed. Using fundamental principles, a discrete-bubble model was first developed to predict plume dynamics and gas transfer for a circular bubble-plume diffuser. This approach has subsequently been validated in a large vertical tank and applied successfully at full-scale to an airlift aerator as well as to both circular and linear bubble-plume diffusers. The unified suite of models, all based on simple discrete-bubble dynamics, represents the current state-of-the-art for designing systems to add oxygen to stratified lakes and reservoirs. An existing linear bubble plume model was improved, and data collected from a full-scale diffuser installed in Spring Hollow Reservoir, Virginia (U.S.A.) were used to validate the model. The depth of maximum plume rise was simulated well for two of the three diffuser tests. Temperature predictions deviated from measured profiles near the maximum plume rise height, but predicted dissolved oxygen profiles compared very well to observations. Oxygen transfer within the hypolimnion was independent of all parameters except initial bubble radius. The results of this work suggest that plume dynamics and oxygen transfer can successfully be predicted for linear bubble plumes using the discrete-bubble approach. To model the complex interaction between a bubble plume used for hypolimnetic oxygenation and the ambient water body, a model for a linear bubble plume was coupled to two reservoir models, CE-QUAL-W2 (W2) and Si3D. In simulations with a rectangular basin, predicted oxygen addition was directly proportional to the update frequency of the plume model. W2 calculated less oxygen input to the basin than Si3D and significantly less mixing within the hypolimnion. The coupled models were then applied to a simplified test of a full-scale linear diffuser. Both the W2 and Si3D coupled models predicted bulk hypolimnetic DO concentrations well. Warming within the hypolimnion was overestimated by both models, but more so by W2. The lower vertical resolution of the reservoir grid in W2 caused the plume rise height to be over-predicted, enhancing erosion of the thermocline. / Ph. D.
46

Effective Modeling of Nutrient Losses and Nutrient Management Practices in an Agricultural and Urbanizing Watershed

Liu, Yingmei 11 January 2012 (has links)
The Lake Manassas Watershed is a 189 km2 basin located in the Northern Virginia suburbs of Washington, DC. Lake Manassas is a major waterbody in the watershed and serves as a drinking water source for the City of Manassas. Lake Manassas is experiencing eutrophication due to nutrient loads associated with agricultural activities and urban development in its drainage areas. Two watershed model applications using HSPF, and one receiving water quality model application using CE-QUAL-W2, were linked to simulate Lake Manassas as well as its drainage areas: the Upper Broad Run (126.21 km2) and Middle Broad Run (62.79 km2) subbasins. The calibration of the linked model was for the years 2002-05, with a validation period of 2006-07. The aspects of effective modeling of nutrient losses and nutrient management practices in the Lake Manassas watershed were investigated. The study was mainly conducted in the Upper Broad Run subbasin, which was simulated with an HSPF model. For nutrient simulation, HSPF provides two algorithms: PQUAL (simple, empirically based) and AGCHEM (detailed, process-based). This study evaluated and compared the modeling capabilities and performance of PQUAL and AGCHEM, and investigated significant inputs and parameters for their application. Integral to the study was to develop, calibrate and validate HSPF/PQUAL and HSPF/AGCHEM models in the Upper Broad Run subbasin. "One-variable-at-a-time" sensitivity analysis was conducted on the calibrated Upper Broad Run HSPF/PQUAL and HSPF/AGCHEM models to identify significant inputs and parameters for nutrient load generation. The sensitivity analysis results confirmed the importance of accurate meteorological inputs and flow simulation for effective nutrient modeling. OP (orthophosphate phosphorus) and NH4-N (ammonium nitrogen) loads were sensitive to PQUAL parameters describing pollutant buildup and washoff at land surface. The significant PQUAL parameter for Ox-N (oxidized nitrogen) load was groundwater nitrate concentration. For the HSPF/AGCHEM model, fertilizer application rate and time were very important for nutrient load generation. NH4-N and OP loads were sensitive to the AGCHEM parameters describing pollutant adsorption and desorption in the soil. On the other hand, plant uptake of nitrogen played an important role for Ox-N load generation. A side by side comparison was conducted on the Upper Broad Run HSPF/PQUAL and HSPF/AGCHEM models. Both PQUAL and AGCHEM provided good-to-reasonable nutrient simulation. The comparison results showed that AGCHEM performed better than PQUAL for OP simulation, but PQUAL captured temporal variations in the NH4-N and Ox-N loads better than AGCHEM. Compared to PQUAL, AGCHEM is less user-friendly, requires a lot more model input parameters and takes much more time in model development and calibration. On the other hand, use of AGCHEM affords more model capabilities, such as tracking nutrient balances and evaluating alternative nutrient management practices. This study also demonstrated the application of HSPF/AGCHEM within a linked watershed-reservoir model system in the Lake Manassas watershed. By using the outputs generated by the HSPF/AGCHEM models in the Upper Broad Run and Middle Broad Run subbasins, the Lake Manassas CE-QUAL-W2 model adequately captured water budget, temporal and spatial distribution of water quality constituents associated with summer stratification in the lake. The linked model was used to evaluate water quality benefits of implementing nutrient management plan in the watershed. The results confirmed that without the nutrient management plan OP loads would be much higher, which would lead to OP enrichment and enhanced algae growth in Lake Manassas. / Ph. D.
47

A Complex, Linked Watershed-Reservoir Hydrology and Water Quality Model Application for the Occoquan Watershed, Virginia

Xu, Zhongyan 08 February 2006 (has links)
The Occoquan Watershed is a 1515 square kilometer basin located in northern Virginia and contains two principal waterbodies: the Occoquan Reservoir and Lake Manassas. Both waterbodies are principal drinking water supplies for local residents and experience eutrophication and summer algae growth. They are continuously threatened by new development from the rapid expansion of the greater Washington D.C. region. The Occoquan model, consisting of six HSPF and two CE-QUAL-W2 submodels linked in a complex way, has been developed and applied to simulate hydrology and water quality activities in the two major reservoirs and the associated drainage areas. The studied water quality constituents include temperature, dissolved oxygen, ammonium nitrogen, oxidized nitrogen, orthophosphate phosphorus, and algae. The calibration of the linked model is for the years 1993-95, with a validation period of 1996-97. The results show that a successful calibration can be achieved using the linked approach, with moderate additional effort. The spatial and temporal distribution of hydrology processes, nutrient detachment and transport, stream temperature and dissolved oxygen were well reproduced by HSPF submodels. By using the outputs generated by HSPF submodels, the CE-QUAL-W2 submodels adequately captured the water budgets, hydrodynamics, temperature, temporal and spatial distribution of dissolved oxygen, ammonium nitrogen, oxidized nitrogen, orthophosphate phosphorus, and algae in Lake Manassas and Occoquan Reservoir. This demonstrates the validity of linking two types of state of the art water quality models: the watershed model HSPF and the reservoir model CE-QUAL-W2. One of the advantages of the linked model approach is to develop a direct cause and effect relationship between upstream activities and downstream water quality. Therefore, scenarios of various land use proposals, BMP implementation, and point source management can be incorporated into HSPF applications, so that the CE-QUAL-W2 submodels can use the boundary conditions corresponding with these scenarios to predict the water quality variations in the receiving waterbodies. In this research, two land use scenarios were developed. One represented the background condition assuming all the land covered by forest and the other represented the environmental stress posed by future commercial and residential expansion. The results confirm the increases of external nutrient loads due to urbanization and other human activities, which eventually lead to nutrient enrichment and enhanced algae growth in the receiving waterbodies. The increases of external nutrient loads depend on land use patterns and are not evenly spread across the watershed. The future development in the non urban areas will greatly increase the external nutrient production and BMPs should be implemented to reduce the potential environmental degradation. For the existing urban areas, the model results suggest a potential threshold of nutrient production despite future land development. The model results also demonstrate the catchment function of Lake Manassas in reducing nutrient transport downstream. / Ph. D.
48

Le Motet et l’Arbre de Jessé. Les pièces à deux voix sur la teneur FLOS FILIUS EJUS dans le codex W2 / Motets and the tree of jesse. Two-part compositions on the tenor FLOS FILIUS EJUS in the manuscript W2

Dobby, Margaret 21 December 2012 (has links)
Les motets du XIIIe siècle chantés sur le répons Stirps Jesse forment l'apogée d'une tradition exégétique, iconographique et musicale plus connue sous le nom d'« arbre de Jessé ». Le répons, attribué à Fulbert de Chartres (mort en 1028), évoque de façon métaphorique les liens entre Marie et son Fils. Il rappelle ainsi un des fondements du dogme chrétien : l'Incarnation charnelle de Dieu par l'intermédiaire de la Vierge. Son utilisation dans les motets n'est donc pas anodine. Le Stirps Jesse, ou plus fréquemment la seconde partie de son verset FLOS FILIUS EJUS, a été repris et ordonné de façon rythmique pour servir à la création d'une polyphonie textuelle et musicale. La voix empruntée ou teneur détermine ainsi la mélodie, la longueur des phrases mélodiques et des vers du double. Pourtant, malgré ces contraintes et les nombreux contrafacta, l'étude démontre l'existence de liens structurels entre texte et musique dans les motets à deux voix sur FLOS FILIUS EJUS conservés dans le manuscrit W2. Les relations entre texte et musique reposent ainsi le plus souvent sur la coïncidence entre la disposition des poèmes et l'organisation des répétitions motiviques (colores), des registres et des rythmes / Thirteenth-Century motets composed on the response Stirps Jesse belong to a great exegetical, iconographical and musical tradition well-known as the « Tree of Jesse ». The response, which is possibly composed by Fulbert of Chartres (d. 1028), express the relationships between Mary and her Son. It calls to mind one of the most important Christian believes as the flesh Embodiment of God thanks to the Virgin which is one of the most important Christian dogmas. The Stirps Jesse, or more often the second part of the verse FLOS FILIUS EJUS, is rhythmically organized in order to create a textual and musical polyphony. The melody, the lengths of musical phrases and of the line of the upper part depend intimately on this quotation or tenor. Even if the tenor is of great influence on the polyphony, this study demonstrates that the textual structure of the upper part corresponds to the musical organization in the two-part motets on FLOS FILIUS EJUS in the manuscript W2. The relationships between poem and melody are built on the close connection between the structural organization of the text and of the melody thanks to the melodic patterns (colores), register and rhythms
49

The sound of laughter in Romantic poetry

Ward, Matthew January 2015 (has links)
This thesis offers the first critical examination of the sound of laughter in Romantic poetry. Part one locates laughter in the history of ideas of the seventeenth and eighteenth centuries, and explores the interplay between laughter and key intellectual, aesthetic, ethical, and social issues in the Romantic period. I chart a development in thinking about laughter from its primary association with ridicule and the passions up to the early decades of the eighteenth century, to its emerging symbiosis with politeness and aesthetic judgement, before a reassertion of laughter's signification of passion and naturalness by the end of the eighteenth century. Laughter provides an innovative means of mapping cultural markers, and I argue that it highlights shifts in standards and questions of taste. Informed by this analysis, part two offers a series of historically aware close readings of Romantic poetry that identify both an indebtedness to, and refutation of, earlier and contemporaneous ideas about laughter. Rather than having humour or comedy as its central concerns, this thesis identifies the pervasive and capricious influence of the sound of the laugh in the writing of Robert Burns, William Blake, William Wordsworth, Samuel Taylor Coleridge, Leigh Hunt, Lord Byron, Percy Shelley, and John Keats. I detect the heterogeneous representations of laughter in their work that runs across a diverse range of genres, poetic forms, themes, and contexts. As such, I argue against the serious versus the humorous binary which prevails in literary criticism of Romanticism, and suggest that laughter articulates the interplay between the elegiac and the comic, the sublime and the ridiculous, the solitary and the communal. Moreover, I detect a double-naturedness to the sound of laughter in Romantic poetry that registers the subject's capacity to signify both consensus and dispute. This inherent polarity creates a tension in the poems as laughter ironically challenges what it also affirms. Never singularly fixed, the sound of laughter reveals the protean nature of Romantic verse.
50

Surveillance of Negative Binomial and Bernoulli Processes

Szarka, John Louis III 03 May 2011 (has links)
The evaluation of discrete processes are performed for industrial and healthcare processes. Count data may be used to measure the number of defective items in industrial applications or the incidence of a certain disease at a health facility. Another classification of a discrete random variable is for binary data, where information on an item can be classified as conforming or nonconforming in a manufacturing context, or a patient's status of having a disease in health-related applications. The first phase of this research uses discrete count data modeled from the Poisson and negative binomial distributions in a healthcare setting. Syndromic counts are currently monitored by the BioSense program within the Centers for Disease Control and Prevention (CDC) to provide real-time biosurveillance. The Early Aberration Reporting System (EARS) uses recent baseline information comparatively with a current day's syndromic count to determine if outbreaks may be present. An adaptive threshold method is proposed based on fitting baseline data to a parametric distribution, then calculating an upper-tailed p-value. These statistics are then converted to an approximately standard normal random variable. Monitoring is examined for independent and identically distributed data as well as data following several seasonal patterns. An exponentially weighted moving average (EWMA) chart is also used for these methods. The effectiveness of these methods in detecting simulated outbreaks in several sensitivity analyses is evaluated. The second phase of research explored in this dissertation considers information that can be classified as a binary event. In industry, it is desirable to have the probability of a nonconforming item, p, be extremely small. Traditional Shewhart charts such as the p-chart, are not reliable for monitoring this type of process. A comprehensive literature review of control chart procedures for this type of process is given. The equivalence between two cumulative sum (CUSUM) charts, based on geometric and Bernoulli random variables is explored. An evaluation of the unit and group--runs (UGR) chart is performed, where it is shown that the in--control behavior of this chart is quite misleading and should not be recommended for practitioners. / Ph. D.

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