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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.
341

Tratamento e recuperação da água de lavagem dos filtros de uma estação de filtração direta e simulação da disposição dos lodos em estações de tratamento de esgoto / Treatment and recovery of wastes from backwash filter on direct filter water treatment systems and simulation of sludge disposal in wastewater treatment systems

Escobar Rivera, Juan Carlos 16 February 2001 (has links)
Foi pesquisada a aplicação de métodos, em nível de laboratório, através dos quais é possível otimizar, tratar e dispor resíduos de lavagem de filtros de estações de tratamento de água (Caso ETA do rio Descoberto - ETA-RD Brasília). Na clarificação da água de lavagem dos filtros, observou-se o efeito favorável da adição de polímero para melhorar a separação líquido-sólido é, portanto, as eficiências de remoção de turbidez, cor aparente, sólidos suspensos e coliformes totais. Observou-se melhor sedimentabilidade do lodo a ser desaguado. Os ensaios de centrifugação, em escala de bancada, mostraram que o método aplicado auxilia na determinação da dosagem a ser usada numa centrífuga em escala real. Foram avaliados três métodos de disposição do lodo adensado da ETA-RD em ETE: 1) sedimentação com esgoto sanitário e posterior digestão anaeróbia do lodo; 2) Digestão anaeróbia e 3) digestão aeróbia. Os melhores resultados foram obtidos com a digestão anaeróbia. Os estudos realizados mostraram que há diversas alternativas de tratamento e disposição desses resíduos, mas é necessário, sempre que possível, a avaliação das diferentes alternativas para selecionar a(s) mais apropriada(s) a cada caso em particular, pois fatores como custos e disponibilidade de de sistemas ou equipamentos, definirão a aplicabilidade ou não de determinado método. / It was researched the application of methods on laboratory bench scale to optimize the reuse, treatment and disposal of wastes from filter backwash of Water Treatment Plant - WTP (WTP-RD Descoberto River, Brasília case). In the clarification process of this waste, favorable effect of addition of polymer for best liquid-solid separation and, thus, better removal efficiencies of turbidity, apparent color, suspended solids and total coliforms was observed. Better sedimentability of the sludge occurred. The centrifugation tests showed that the applied method help on determination of dosagem to be used in full scale. Three methods to dispose thickened sludge of WTP-RD on wastewater treatment Plants - WWTP were evaluated: 1) Sedimentation with domestic sewage and anaerobic digestion of sludge; 2) Anaerobic digestion and 3) Aerobic digestion. Best results were obtained with anaerobic digestion. The results showed that there are alternatives of treatment and disposal of wastes of WTP, but is necessary, if possible, to make the evaluation of this alternatives to select the most appropriate(s) in each case because factors as costs, systems or equipments availability, will define the applicability or not of a particular method.
342

Tratamento e recuperação da água de lavagem dos filtros de uma estação de filtração direta e simulação da disposição dos lodos em estações de tratamento de esgoto / Treatment and recovery of wastes from backwash filter on direct filter water treatment systems and simulation of sludge disposal in wastewater treatment systems

Juan Carlos Escobar Rivera 16 February 2001 (has links)
Foi pesquisada a aplicação de métodos, em nível de laboratório, através dos quais é possível otimizar, tratar e dispor resíduos de lavagem de filtros de estações de tratamento de água (Caso ETA do rio Descoberto - ETA-RD Brasília). Na clarificação da água de lavagem dos filtros, observou-se o efeito favorável da adição de polímero para melhorar a separação líquido-sólido é, portanto, as eficiências de remoção de turbidez, cor aparente, sólidos suspensos e coliformes totais. Observou-se melhor sedimentabilidade do lodo a ser desaguado. Os ensaios de centrifugação, em escala de bancada, mostraram que o método aplicado auxilia na determinação da dosagem a ser usada numa centrífuga em escala real. Foram avaliados três métodos de disposição do lodo adensado da ETA-RD em ETE: 1) sedimentação com esgoto sanitário e posterior digestão anaeróbia do lodo; 2) Digestão anaeróbia e 3) digestão aeróbia. Os melhores resultados foram obtidos com a digestão anaeróbia. Os estudos realizados mostraram que há diversas alternativas de tratamento e disposição desses resíduos, mas é necessário, sempre que possível, a avaliação das diferentes alternativas para selecionar a(s) mais apropriada(s) a cada caso em particular, pois fatores como custos e disponibilidade de de sistemas ou equipamentos, definirão a aplicabilidade ou não de determinado método. / It was researched the application of methods on laboratory bench scale to optimize the reuse, treatment and disposal of wastes from filter backwash of Water Treatment Plant - WTP (WTP-RD Descoberto River, Brasília case). In the clarification process of this waste, favorable effect of addition of polymer for best liquid-solid separation and, thus, better removal efficiencies of turbidity, apparent color, suspended solids and total coliforms was observed. Better sedimentability of the sludge occurred. The centrifugation tests showed that the applied method help on determination of dosagem to be used in full scale. Three methods to dispose thickened sludge of WTP-RD on wastewater treatment Plants - WWTP were evaluated: 1) Sedimentation with domestic sewage and anaerobic digestion of sludge; 2) Anaerobic digestion and 3) Aerobic digestion. Best results were obtained with anaerobic digestion. The results showed that there are alternatives of treatment and disposal of wastes of WTP, but is necessary, if possible, to make the evaluation of this alternatives to select the most appropriate(s) in each case because factors as costs, systems or equipments availability, will define the applicability or not of a particular method.
343

A Historical and Archaeological Study of the Nineteenth Century Hudson's Bay Company Garden at Fort Vancouver: Focusing on Archaeological Field Methods and Microbotanical Analysis

Dorset, Elaine C. 01 January 2012 (has links)
The Hudson's Bay Company (HBC), a British fur-trading enterprise, created a large garden at Fort Vancouver, now in southwest Washington, in the early- to mid-19th century. This fort was the administrative headquarters for the HBC's activities in western North America. Archaeological investigations were conducted at this site in 2005 and 2006 in order to better understand the role of this large space, which seems incongruous in terms of resources required, to the profit motive of the HBC. Questions about the landscape characteristics, and comments by 19th century visitors to the site provided the impetus for theoretical research of gardens as representations of societal power, and, on a mid-range level, the efficacy of certain archaeological methods in researching this type of space. Documentary research related to the history of the HBC Garden was also conducted, including previous archaeology completed at the site. The results of these lines of inquiry are presented, providing insight as to the diverse roles this Garden fulfilled in the survival of the HBC in the region - as a commercial enterprise, as a microcosm of western societal practice, and in the health of its employees.
344

"As Long as the Mighty Columbia River Flows": the Leadership and Legacy of Wilson Charley, a Yakama Indian Fisherman

Hedberg, David-Paul Brewster 13 April 2017 (has links)
On March 10, 1957, the United States Army Corps of Engineers completed The Dalles Dam and inundated Celilo Falls, the oldest continuously inhabited site in North America and a cultural and economic hub for Indigenous people. In the negotiation of treaties between the United States, nearly one hundred years earlier, Indigenous leaders reserved access to Columbia River fishing sites as they ceded territory and retained smaller reservations. In the years before the dam's completion, leaders, many of who were the descendants of earlier treaty signatories, attempted to stop the dam and protect both fishing sites from the encroachment of state and federal regulations and archaeological sites from destruction. This study traces the work of Wilson Charley, a Native fisherman, a member of the Yakama Nation's Tribal Council, and great-grandson of one of the 1855 treaty signatories. More broadly, this study places Indigenous actors on a twentieth-century Columbia River while demonstrating that they played active roles in the protest and management of areas affected by The Dalles Dam. Using previously untapped archival sources--a substantial cache of letters--my analysis illustrates that Charley articulated multiple strategies to fight The Dalles Dam and regulations to curtail Native's treaty fishing rights. Aiming to protect the 1855 treaty and stop The Dalles Dam, Charley created Native-centered regulatory agencies. He worked directly with politicians and supported political candidates, like Richard Neuberger, that favored Native concerns. He attempted to build partnerships with archaeologists and landscape preservationists concerned about losing the area's rich cultural sites. Even after the dam's completion, he conceptualized multiple tribal economic development plans that would allow for Natives' cultural and economic survival. Given the national rise of technological optimism and the willingness for the federal government to terminate its relationship with federally recognized tribes, Charley realized that taking the 1855 treaty to court was too risky for the political climate of the 1950s. Instead, he framed his strategies in the language of twentieth-century conservation, specifically to garner support from a national audience of non-natives interested in protecting landscapes from industrial development. While many of these non-native partners ultimately failed him, his strategies are noteworthy for three reasons. First, he cast the fight to uphold Native treaty rights in terms that were relevant to non-natives, demonstrating his complex understanding of the times in which he lived. Second, his strategies continued an ongoing struggle for Natives to fish at their treaty-protected sites, thereby documenting an overlooked period between the fishing rights cases of the turn of the twentieth century and the 1960s and 1970s. Charley left a lasting legacy that scholars have not recognized because many of his visionary ideas came to fruition decades later. Finally, my analysis of Charley's letters also documents personal details that afford readers the unique perspective of one Indigenous person navigated through a tumultuous period in the Pacific Northwest and Native American history.
345

Wind induced torsional fatigue behavior of truss bridge verticals

Keller, Philipp 13 June 2012 (has links)
The Astoria-Megler Bridge is a 6.6 kilometer (4.1 mile) long bridge, connecting Oregon and Washington on US 101, with a continuous steel truss main span of 376 m (1232 ft). It is the second longest main span bridge of this type in the world. Due to vortex shedding, some of the long truss verticals exhibit wind-induced torsional vibrations. These vibrations can create large numbers of repeated stress cycles in the truss verticals and the gusset plate assemblies. The members and connections were not designed for such conditions and the impact of this behavior on the service life of the bridge is uncertain. A full-scale representation of one of the truss verticals observed to exhibit such wind induced torsional response was fabricated and tested in the Structural Engineering Research Laboratory at Oregon State University. Experimental data of the rotational behavior and the stress distribution along the vertical were collected using inclinometers, an angular rate sensor, and uniaxial and rosette strain gages. The data collected were compared with existing analytical methods and predictions from finite element models. The observed experimental results including twist angle, stress distribution, and stress magnitude were well captured by both the finite element model and the analytical equations. Using analytical expressions, the fatigue lives of the existing bridge verticals were predicted based on assumed storm duration and recurrence. / Graduation date: 2013
346

The Hanford Laboratories and the growth of environmental research in the Pacific Northwest, 1943 to 1965

Ellis, D. Erik 17 December 2002 (has links)
The scientific endeavors that took place at Hanford Engineer Works, beginning in World War II and continuing thereafter, are often overlooked in the literature on the Manhattan Project, the Atomic Energy Commission, and in regional histories. To historians of science, Hanford is described as an industrial facility that illustrates the perceived differences between academic scientists on the one hand and industrial scientists and engineers on the other. To historians of the West such as Gerald Nash, Richard White, and Patricia Limerick, Hanford has functioned as an example of the West's transformation during in World War II, the role of science in this transformation, and the recurring impacts of industrialization on the western landscape. This thesis describes the establishment and gradual expansion of a multi-disciplinary research program at Hanford whose purpose was to assess and manage the biological and environmental effects of plutonium production. By drawing attention to biological research, an area in which Hanford scientists gained distinction by the mid 1950s, this study explains the relative obscurity of Hanford's scientific research in relation to the prominent, physics-dominated national laboratories of the Atomic Energy Commission. By the mid 1960s, with growing public concern over radiation exposure and changes in the government's funding patterns for science, Hanford's ecologically relevant research provided a recognizable and valuable identity for the newly independent, regionally-based research laboratory. With funding shifts favoring the biological and environmental sciences in the latter half of the twentieth-century, Hanford scientists were well prepared to take advantage of expanding opportunities to carve out a permanent niche on the border of American science. / Graduation date: 2003
347

Water en sanitasie in die landelike Hoëveldse woning 1840 -1910: n kultuurhistoriese studie / deur Claudia Gouws

Gouws, Claudia January 2007 (has links)
The location of the site where the pioneers settled permanently was determined by the availability of water in the immediate environment. The Highveld contains fertile soils, a fine climate, and an abundance of water. The area has always been extensively used for crop and stock farming, but in general, mixed farming was practiced. The farmers depended on the availability of water, therefore their experiences, observations, weather forecasts, and conclusions, developed into a popular folk meteorology. Furthermore, environmental factors such as local topography, micro climate, hydrography, ground fertility, and the appearance of natural vegetation determined whether or not an area was suitable for permanent residence. The farmstead may be divided into three functional zones (the core-, extended-, and outer farmyard) that are joined by a canal network, used for irrigation and drinking water. The farmhouse and buildings, erected a stones throw away from the water source, served as a focal point for the activities of the farmer. The manipulation of the water source by obstruction of streams and the construction of water canals, weirs and water furrows, assisted the farmer in planning his activities and in using the water to his advantage. The settlement and development of the residence on the rural parts of the Highveld may be divided into three distinct phases. Firstly, the temporary trekboer phase, secondly the pioneer phase and thirdly the permanent settlement phase. The permanence of residence had a direct influence in the layout of the house, the method of construction, and the use of the available water supply. At first, the trekkers were content to reside in roof dwellings (their wagons and tents and a grass screen as their kitchen and a hut near a spring). The first houses were hartbieshuise and kapsteilhuise. The more permanent homesteads of the earlier settlers were a simple rectangular structure (pioneer house) with a saddle grass roof. With the introduction of galvanised iron sheeting, the house was expanded and developed into the veranda-, stoeproom- and a flat roofed rectangular house. This development resulted into a typical rural Highveld homestead. After the discovery of gold in the vicinity of the Witwatersrand, the first gold rush took place resulting in the proclamation of Johannesburg in 1886. Prospectors, mostly foreigners, descended upon the Witwatersrand. Housing took on a more planned structure resembling the late Victorian period of housing in England. The water supply and drainage systems were planned and improved, making it possible to provide running water to kitchens and bathrooms. This impacted firstly on the upper riches of society in the cities, later on the lower middle classes and lastly on the rural areas. European technology regarding the supply of hot pipe water and drainage systems changed the layout of the house. The cooking activity moved from outside behind a screen to a seperate room inside the house. Inevitable changes regarding collecting, storage, purpose, saving and drainage of household water took place. Between 1840 and 1910, evolutionary changes took place regarding sanitation, water supply and personal hygiene. Being part of a particular social class made certain facilities available to certain individuals. A rural Highveld dwelling rarely included sanitary facilities, instead dwellers had a more primitive wash basin in each room in which they washed daily. On a Saturday, a weekly bath was taken in a bathtub in the kitchen or bedroom. Trekkers simply relieved themselves outside. A revolution in sanitary habits and facilities became inevitable. The Victorian dwelling on the Highveld was built according to a standard plan, including a flush water system already in place. This was the ultimate manifestation of sophistication and civilization. The aim of this investigation is to identify the similarities and differences between the use of water by the pioneer, the poor people and the wealthy in their rural dwellings. Furthermore, information has been obtained regarding water usage and sanitation in the bathroom and kitchen in the rural dwelling to be useful in the area of historic architecture and the heritage of our water history. / Thesis (M.A. (History))--North-West University, Vaal Triangle Campus, 2008.
348

Meeting of the magmas : the evolutionary history of the Kalama Eruptive Period, Mount St. Helens, Washington

Lieuallen, Athena Erin 14 October 2010 (has links)
Comprehension of eruptive histories is critical in understanding the evolution of magmatic systems at arc volcanoes and may supply evidence to the petrogenesis of intermediate and evolved magmas. Within the 300 ka eruptive history of Mount St. Helens, Washington, the Kalama Eruptive Period, 1479- ~1750 CE was bracketed by interludes of quiescence (Hoblitt et al., 1980) and thus likely represents an entire eruptive cycle within a span of 300 years. Study of the magmatic evolution during this short time period provides key information regarding inputs and the plumbing system of Mount St. Helens. This research aims to enhance comprehension of processes leading to the petrogenesis of intermediate magmas by providing whole rock and phase geochemical data of an eruptive cycle, thereby providing constraints on the magmatic evolution of the Kalama Eruptive Period. The eruptive sequence is divided into early, middle and late subperiods. The early Kalama began with two dacitic plinian eruptions and continued with smaller eruptions of dacite domes (64.4-66.5 wt% SiO₂) that included quenched mafic inclusions (53.7-57.7 wt% SiO₂). The middle Kalama signified the onset of basaltic andesite and andesite eruptions ranging between 55.5-58.5 wt % SiO₂. Subsequently, summit domes that began as felsic andesite (61-62.5 wt% SiO₂) and transitioned to dacite (62.5-64.6 wt% SiO₂) dominated the late Kalama. Previous work on Kalama-aged rocks suggests magma mixing is an integral process in their production. Compositions and textures of crystal phases, in addition to the presence of xenocrysts in middle and late Kalama rocks, confirm mechanical mixing of magmas likely produced many of the sampled compositions. New petrographic observations were integrated with new whole rock and phase EMP and LA-ICP-MS data and the known stratigraphy in order to constrain the magmatic and crustal components active during the Kalama Eruptive Period. New findings include: 1. Two populations of quenched mafic inclusions, one olivine-rich and one olivine-poor, are identified from the early Kalama based on mineralogy, textures, and major and trace element chemistry. Major element modeling shows crustal anatexis of plutonic inclusions found in early Kalama dacites could produce the felsic magma source of the olivine-poor population. The olivine-rich population incorporated cumulate material. 2. Four distinct lava populations erupted during the early part of the middle Kalama (X lavas), including two found exclusively in lahar deposits: M-type lahars are the most mafic, B-type lahars are more mixed, the Two Finger Flow was previously grouped with other middle Kalama-age lavas, and the X lava (in situ) has unique geochemical and textural character. X tephras likely correlate with the lavas. 3. There were at least three mafic source contributions at Mount St. Helens during the eruptive period: the parent to the X deposits, the cumulate material in the olivine-rich QMIs, and the calc-alkaline parent to the MKLV and SDO. The magma reservoir at Mount St. Helens has been modeled as a single, elongate chamber (Pallister et al., 1992). Multiple coeval basaltic or basaltic andesite parents fluxing into the magmatic system beneath the volcano could indicate a more complex magma chamber structure. / Graduation date: 2011
349

Critical care nurses' perceptions and attitudes on the use of the objective structured competence examination (OSCE) in critical care education in two hospitals in eThekwini, Durban, South Africa.

Maphumulo, Winnie Thembisile. 30 October 2014 (has links)
Intensive care units in South Africa have been faced with various challenges which in turn affect the working condition of critical care nurses, thus leading to poor productivity. Nurses in the work environment blame this poor work quality of nursing to the way critical care nurses are trained and assessed in nursing schools. There is general concern that graduate nursing students lack the knowledge and skills necessary to equip them to work in intensive units. Objectives: To measure the perceptions of critical care nursing students as well qualified critical care nurses on the use of OSCE as a valid and reliable tool to assess clinical competence in critical care nursing students. Methods: A quantitative approach and descriptive survey was administered to critical care nursing students and qualified critical care nurses who had participated in OSCE examination. The intensive care departments of two provincial (states) hospitals and (provincial) nursing college that trained critical care nurses were used. Results: The findings revealed that OSCE was still overwhelmingly accepted as a relevant tool for assessing clinical competencies in Critical Care courses by both students and staff. It was also clear that the students did not believe that all the competencies required in the ICU environment can be assessed using the OSCE method. Discussion: Critical care nursing educators are facing a challenge to develop more comprehensive method for assessing clinical skills in critical care students nurses since OSCE x examination cannot assess all the skills that are necessary in intensive care environment. In order for effective learning to take place during assessment, it is extremely important for nurse educators to give formative feedback in OSCE. / M.N. University of KwaZulu-Natal, Durban 2012.
350

Water en sanitasie in die landelike Hoëveldse woning 1840 -1910: n kultuurhistoriese studie / deur Claudia Gouws

Gouws, Claudia January 2007 (has links)
The location of the site where the pioneers settled permanently was determined by the availability of water in the immediate environment. The Highveld contains fertile soils, a fine climate, and an abundance of water. The area has always been extensively used for crop and stock farming, but in general, mixed farming was practiced. The farmers depended on the availability of water, therefore their experiences, observations, weather forecasts, and conclusions, developed into a popular folk meteorology. Furthermore, environmental factors such as local topography, micro climate, hydrography, ground fertility, and the appearance of natural vegetation determined whether or not an area was suitable for permanent residence. The farmstead may be divided into three functional zones (the core-, extended-, and outer farmyard) that are joined by a canal network, used for irrigation and drinking water. The farmhouse and buildings, erected a stones throw away from the water source, served as a focal point for the activities of the farmer. The manipulation of the water source by obstruction of streams and the construction of water canals, weirs and water furrows, assisted the farmer in planning his activities and in using the water to his advantage. The settlement and development of the residence on the rural parts of the Highveld may be divided into three distinct phases. Firstly, the temporary trekboer phase, secondly the pioneer phase and thirdly the permanent settlement phase. The permanence of residence had a direct influence in the layout of the house, the method of construction, and the use of the available water supply. At first, the trekkers were content to reside in roof dwellings (their wagons and tents and a grass screen as their kitchen and a hut near a spring). The first houses were hartbieshuise and kapsteilhuise. The more permanent homesteads of the earlier settlers were a simple rectangular structure (pioneer house) with a saddle grass roof. With the introduction of galvanised iron sheeting, the house was expanded and developed into the veranda-, stoeproom- and a flat roofed rectangular house. This development resulted into a typical rural Highveld homestead. After the discovery of gold in the vicinity of the Witwatersrand, the first gold rush took place resulting in the proclamation of Johannesburg in 1886. Prospectors, mostly foreigners, descended upon the Witwatersrand. Housing took on a more planned structure resembling the late Victorian period of housing in England. The water supply and drainage systems were planned and improved, making it possible to provide running water to kitchens and bathrooms. This impacted firstly on the upper riches of society in the cities, later on the lower middle classes and lastly on the rural areas. European technology regarding the supply of hot pipe water and drainage systems changed the layout of the house. The cooking activity moved from outside behind a screen to a seperate room inside the house. Inevitable changes regarding collecting, storage, purpose, saving and drainage of household water took place. Between 1840 and 1910, evolutionary changes took place regarding sanitation, water supply and personal hygiene. Being part of a particular social class made certain facilities available to certain individuals. A rural Highveld dwelling rarely included sanitary facilities, instead dwellers had a more primitive wash basin in each room in which they washed daily. On a Saturday, a weekly bath was taken in a bathtub in the kitchen or bedroom. Trekkers simply relieved themselves outside. A revolution in sanitary habits and facilities became inevitable. The Victorian dwelling on the Highveld was built according to a standard plan, including a flush water system already in place. This was the ultimate manifestation of sophistication and civilization. The aim of this investigation is to identify the similarities and differences between the use of water by the pioneer, the poor people and the wealthy in their rural dwellings. Furthermore, information has been obtained regarding water usage and sanitation in the bathroom and kitchen in the rural dwelling to be useful in the area of historic architecture and the heritage of our water history. / Thesis (M.A. (History))--North-West University, Vaal Triangle Campus, 2008.

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