O aumento da demanda por água potável em função do crescimento populacional, vem sendo objeto de estudo de diversos pesquisadores que buscam meios de otimizar o uso desse recurso. Desse modo, ao longo dos anos os equipamentos sanitários foram sendo aperfeiçoados para tornarem-se mais eficientes. Uma preocupação é o impacto nos ramais e coletores de sistemas prediais de esgotos sanitários, uma vez que os componentes economizadores ao demandarem menos água em sua operação, retornam vazões menores para a rede predial de esgoto sanitário e, consequentemente, geram ondas menores que impactam negativamente na autolimpeza dos condutos horizontais. Nesse sentido, o objetivo da pesquisa foi investigar, em laboratório, as vazões e profundidades da lâmina d´água do escoamento em ramais e coletores do sistema de esgotos sanitários de edifícios residenciais unifamiliares, tendo em vista a redução de diâmetros de 100 mm para 75 mm. A pesquisa foi realizada em laboratório vertical, onde foi montada uma configuração típica de um banheiro residencial, localizada no pavimento superior. Foram utilizadas bacias sanitárias com volume nominal de descarga de 6 L e 4,8 L, um chuveiro com vazão constante de 0,20 L/s e um lavatório com vazão constante de 0,15 L/s. As bacias sanitárias foram ensaiadas para calibração, segundo a NBR 15097 (ABNT, 2011) e ambas obtiveram resultados satisfatórios em todos os requisitos dessa norma. Foram variados os diâmetros dos ramais e coletores prediais de 100 mm para 75 mm, com e sem a contribuição da vazão em regime permanente de 0,35 L/s proveniente de um chuveiro e um lavatório e as declividades variadas em 0%, 1% e 2% nos ramais e 1%, 2% e 3% nos coletores de esgoto. Avaliou-se a influência dos parâmetros declividade, volume de descarga, presença ou não de vazão em regime permanente e diâmetro da tubulação, sobre a velocidade de escoamento da água. Concluiu-se que a redução dos diâmetros dos ramais e coletores de esgoto e a redução do volume de descarga de 6 L para 4,8 L contribuíram para o aumento da velocidade da onda sob as condições de estudo em todo o trecho ensaiado, ou seja, no trecho compreendido entre a bacia sanitária e o tubo de queda e ao longo de todo comprimento de 3 m do coletor de esgoto predial. Não foi estudada a influência da variação dos parâmetros sobre a velocidade de onda em trechos além do coletor de esgoto predial. Sob as condições de estudo, observou-se que a declividade não influencia, de maneira geral, no desempenho do sistema nos trechos ensaiados. A presença de uma vazão em regime permanente contribui para amortizar a energia da onda de descarga da bacia sanitária no ramal de descarga e consequentemente, reduz a velocidade de escoamento da água, o que pode contribuir para a piora do requisito de autolimpeza neste trecho da tubulação. No coletor de esgoto, não foi possível concluir que a presença de vazão em regime permanente tem impacto sobre a velocidade de escoamento da água. Por fim, conclui-se ser possível a redução dos diâmetros dos ramais e coletores do sistema predial de esgoto sanitário. / The increase in the demand for drinking water due to the population growth has been the object of study of several researchers who seek ways to optimize the use of this resource. In this way, over the years sanitary equipment has been improved to become more efficient. One concern is the impact on drains and main drains of building drainage system, since the economizing components, while using less water in their operation, return smaller flows to the sanitary sewage network and consequently lead to the formation of smaller waves that contribute to the self-cleaning of pipes. In this sense, the objective of the research was to investigate, in the laboratory, the flows and the depths of the flow in drains and main drains of residential building drainage system, in order to reduce diameters from 100 mm to 75 mm. The research was carried out in a vertical laboratory, where a typical configuration of a residential bathroom located on the second floor of a two story building was set up. A toilet with a nominal discharge volume of 6 L and 4,8L, a shower with a constant flow rate of 0.20 L/s and a lavatory with a constant flow rate of 0.15 L/s were used. The toilets were tested according to NBR15097 (ABNT, 2011) for calibration and both obtained satisfactory results in all the requirements of this standard. The diameters of the drains and main drains were varied from 100 mm to 75 mm with and without the contribution of the continuous flow rate of 0.35 L/s from a shower and lavatory and the slopes varying in 0%, 1% and 2% in the drains and 1%, 2% and 3% in the main drain. The influence of the parameters like slope, discharge volume, presence or not of continuous flow rate and pipe diameter, on the water flow velocity were evaluated. It was concluded that the reduction of the diameters of the drains and main drains and the reduction of the volume of discharge from 6 L to 4.8 L contribute to the increase of the velocity of the wave in the whole parts of the drain and main drain. It was not studied the influence of the variation of the parameters on the wave velocity on parts beyond the main drain. It was observed that the slope variation does not influence in general performance of the system. The presence of a continuous flow rate contributes to amortize the discharge wave energy from the toilet at the drains and consequently reduces the flow velocity of the water, which may contribute on deterioration of the self-cleaning requirements in this section of the pipeline. In the main drain, it was not possible to conclude that the presence of permanent flow has an impact on the flow velocity of the water.

Os condutores horizontais dos sistemas de coleta de esgotos sanitários, no Brasil e em quase todos os países do mundo, tem sido dimensionados considerando-se o escoamento em regime permanente, o que na realidade não ocorre. Sabendo-se que o escoamento no interior destes condutores acontece em regime não permanente, caracterizado pelo movimento de ondas, devido a aleatoriedade de uso dos aparelhos. Neste trabalho, apresentamos o estudo do escoamento não permanente, verificado, nos ramais e coletores dos sistemas de coleta de esgotos sanitários de edifícios residenciais. As equações diferenciais da continuidade e da quantidade de movimento, que regem este escoamento, são resolvidas pelo método das características. Apresentamos, também, os resultados e análise de várias simulações do programa de computador desenvolvido com base no método das características pelo professor Swaffield, da Universidade Heriot-Watt, Escócia. Os dados de entrada para estas simulações foram obtidos a partir de ensaios laboratoriais de algumas configurações de ambientes sanitários brasileiros, também apresentados neste trabalho. Os resultados destas simulações mostram que a consideração do escoamento em regime não permanente, possibilita a redução dos diâmetros dos ramais e coletores, e consequentemente, a redução dos custos destes sistemas. / Usually horizontal waste pipes of Building Drainage Systems, in Brazil and almost all of countries in the world, are dimensioned considering a steady flow, that does not exist. The random use of the sanitary appliances connected to the Drainage Systems of the building is the responsible for the unsteady flow. We present a study of unsteady partially filled pipeflow for drains and sewers. The differential equations of continuity and motion are solved via the method of characteristics. We present, also, the results and analysis of several simulations using a computational program developed by Prof. Swaffield-Heriot - Watt University, Scotland. The data entry were obtained through laboratorial tests which considered brazilian bathroom configurations, presented in this work. The results show us that the consideration of unsteady flow conduct to the reductions of horizontal waste pipes diameters, consequently to the reduction of the Building Drainage Systems costs.

by Fong Siu Ho, Kwan Po Chiu, Lee Kwong Tong. / Thesis (M.B.A.)--Chinese University of Hong Kong, 1989. / Includes bibliographical references.

The purpose of this research is to investigate the changes in countries of origin and occupational groups of immigrants to the United States after the implementation of the 1965 Immigration Act. The basic policy change in the 1965 Immigration Act was essentially the abolition of the National Origins Quota System. The new law led to obvious changes in the origins of immigrants. The number of Southern European, Asian and Caribbean immigrants significantly increased since the implementation of the Act. The sources of the various occupational groups shifted to some extent. The number of immigrants in the professional and highly skilled categories increased significantly. The impact of the changes aggravated the "brain drain" problem.

Thesis (M.B.A.)--University of Limpopo,2009. / The term “brain drain” became a reality in South Africa after doors opened for South Africans in overseas markets and the emphasis moved from hospital bed based care to total health for all South Africans. The lack of services in rural areas seems a problem with focus on migration of health professionals between rural and urban areas, and even overseas markets, leaving a possible imbalance. More allied health professionals from previously disadvantaged groups are trained but the need in specifically the rural areas continues to rise. Recruitment and retention strategies were implemented for scarce skilled health professionals in the Public Service but no proof is available whether it is successful or not for the allied health professional group. The vacancy rates for allied health professional posts are reportedly too high despite the fact that more candidates are recruited from rural areas to be trained as professionals, hoping they will return to work in rural areas. Allied health professionals seem to be constantly on the move despite the strategies already implemented, reasons for this are unknown. The purpose of this study is to explore and determine if there is an imbalance of allied health workers in rural and urban areas within Limpopo Province. Secondly, it was to determine what factors may influence and contribute to allied health professional‟s decision to consider migration and thirdly to establish if the current recruitment and retention strategies are having the desired outcome. A survey was conducted over a period of three months with respondents representing the dietetic, physiotherapy, radiography, occupational therapy and speech and language therapy professions. The sample population was randomly selected as well as cluster sampling from the different districts within the Limpopo Province. Data was collected from a total of 122 respondents. xv Because the type of data collected was mainly nominal data, graphical and tabular descriptive techniques like frequencies, relative frequencies, tables and graphs were used to provide information. Numerical descriptive techniques were also used to calculate sample statistics and the only statistical technique that involves nominal data, the Chi-Squared Test was also applied. The findings of the research survey enabled the researcher to make final conclusions as well as specific recommendations to the target groups that may benefit from this study in order to change the “brain drain” to a “brain gain” situation for allied health professionals within the Limpopo Province. / N/A

Ces travaux s'inscrivent dans le cadre de la qualification des technologies GaN de UMS et plus particulièrement celle de la technologie GH25, et a pour objectif d’apporter un soutien direct au développement des technologies UMS à base de GaN. Le premier chapitre traite des généralités sur les HEMTs AlGaN/GaN. Le deuxième chapitre est consacré à la description des technologies GH50 et GH25 de UMS. Les éléments passifs de la technologie GH25 ont été caractérisés électriquement et thermiquement, puis des mesures de claquage utilisant une technique d’injection de courant de drain ont été mises en oeuvre sur des HEMTs de la technologie GH50 afin d’évaluer l'aire de sécurité de fonctionnement. Le troisième chapitre est dédié à l'étude des effets parasites rencontrés sur les deux technologies GH50 et GH25.Chacun des effets parasites est décrit puis caractérisé de façon approfondie. Le dernier chapitre se concentre sur l'étude de la fiabilité de la technologie GH25. Après avoir présenté les différentes variantes technologiques, les résultats des tests de vieillissement accéléré mis en oeuvre à UMS sont analysés afin d'évaluer leur impact sur la fiabilité de la technologieGH25 et d’identifier les mécanismes de dégradation et les effets parasites. / This work is incorporated within the framework of the qualification of UMS GaNtechnologies and more particularly of the GH25 technology, and aims to support thedevelopment of UMS GaN based technologies. The first part of this report deals withAlGaN/GaN HEMT generality. The second part is dedicated to the description of the UMStechnologies GH50 and GH25. Passive components of GH25 technology have beencharacterized through electrical and thermal measurement, and then breakdown measurementsusing a drain current injection technique have been carried out on GH50 HEMT in order toevaluate the safe operating area of these devices. The third part is dedicated to the study of theparasitic effects observed on the two technologies GH50 and GH25. Each of these parasiticeffects is described and fully characterized. The last part of this work focuses on the study ofthe GH25 technology. Technological variations are first introduced, and then results ofaccelerated aging test carried out at UMS are analyzed to evaluate their impact on thereliability of the GH25 technology and to identify wear out mechanism and parasitic effects.

Many geoenvironmental applications make use of granular drainage layers. Design guidelines for these drains recommend a granular soil that provides for filtration of the adjacent base soil. Filtration criteria have been developed through laboratory studies in which fine soils under a concentrated gradient of water are protected from erosion by a filter soil. The primary objective in these studies has been the geotechnical stability of earth-fill structures, while drainage was a secondary consideration. Granular drainage layers have therefore been constructed using fine sand. The subsequent migration of fine soil into these drains has resulted in significant loss in permeability. The main research objective was to develop design criteria for granular drains to be used for long term operation in environmental applications. The secondary objective was to investigate the relationships between grain size distribution of drain materials and clogging by fines. This was done through a laboratory study where changes in permeability were measured in granular soils infiltrated with fines. Lastly, the effect of salinity on fines deposition was also investigated. The hypothesis of the current study is that coarser granular drains minimize the impact of clogging and provides a better alternative to traditional drain designs for long term environmental applications. The laboratory study was performed with three granular drainage soils: a French Drain sand designed using the traditional filter design method, a coarser uniform sand, and a coarser graded sand with approximately 40% gravel sized particles. Three fine soils were used to infiltrate the drainage soils; however, their particle size distributions were not significantly different from one another. The results indicate that the permeability of all three drainage soils could be reduced by approximately one order of magnitude with continuous flow of a high concentration of fines (5 g/L). The permeabilities of the sands were reduced to a lesser extent with a lower concentration of fines. Permeabilities of the graded soils decreased more slowly with a lower concentration of fines, when considering pore volumes of flow. However, the rate of permeability decrease was ultimately influenced by the amount of fines delivered to the sample. A lower concentration of fines did not significantly slow the rate of permeability reduction in the uniform sand. All three sands retained a similar mass of fines (samples were split and fines content measured following each test). Salinity in the pore water did not significantly affect deposition, likely due to the fact that the fines contained a small amount of clay sized particles. When considering that all three drainage soils became clogged with fines during the tests, the coarse soils maintained a relatively high permeability due to the fact that their pre-test permeabilities were high. This information, along with the results from the literature review, has led to the development of recommended new design criteria for granular drains to be used for long-term geoenvironmental applications. Test results from an earlier study found that dispersive soils subject to high gradients can be successfully protected by a filter coarser than the coarse graded soil used in the current study. It therefore follows that a granular soil intended for groundwater collection applications can be made to be coarser than the current accepted practice. A proposed granular drain design band is presented in the current study.

Many geoenvironmental applications make use of granular drainage layers. Design guidelines for these drains recommend a granular soil that provides for filtration of the adjacent base soil. Filtration criteria have been developed through laboratory studies in which fine soils under a concentrated gradient of water are protected from erosion by a filter soil. The primary objective in these studies has been the geotechnical stability of earth-fill structures, while drainage was a secondary consideration. Granular drainage layers have therefore been constructed using fine sand. The subsequent migration of fine soil into these drains has resulted in significant loss in permeability. The main research objective was to develop design criteria for granular drains to be used for long term operation in environmental applications. The secondary objective was to investigate the relationships between grain size distribution of drain materials and clogging by fines. This was done through a laboratory study where changes in permeability were measured in granular soils infiltrated with fines. Lastly, the effect of salinity on fines deposition was also investigated. The hypothesis of the current study is that coarser granular drains minimize the impact of clogging and provides a better alternative to traditional drain designs for long term environmental applications. The laboratory study was performed with three granular drainage soils: a French Drain sand designed using the traditional filter design method, a coarser uniform sand, and a coarser graded sand with approximately 40% gravel sized particles. Three fine soils were used to infiltrate the drainage soils; however, their particle size distributions were not significantly different from one another. The results indicate that the permeability of all three drainage soils could be reduced by approximately one order of magnitude with continuous flow of a high concentration of fines (5 g/L). The permeabilities of the sands were reduced to a lesser extent with a lower concentration of fines. Permeabilities of the graded soils decreased more slowly with a lower concentration of fines, when considering pore volumes of flow. However, the rate of permeability decrease was ultimately influenced by the amount of fines delivered to the sample. A lower concentration of fines did not significantly slow the rate of permeability reduction in the uniform sand. All three sands retained a similar mass of fines (samples were split and fines content measured following each test). Salinity in the pore water did not significantly affect deposition, likely due to the fact that the fines contained a small amount of clay sized particles. When considering that all three drainage soils became clogged with fines during the tests, the coarse soils maintained a relatively high permeability due to the fact that their pre-test permeabilities were high. This information, along with the results from the literature review, has led to the development of recommended new design criteria for granular drains to be used for long-term geoenvironmental applications. Test results from an earlier study found that dispersive soils subject to high gradients can be successfully protected by a filter coarser than the coarse graded soil used in the current study. It therefore follows that a granular soil intended for groundwater collection applications can be made to be coarser than the current accepted practice. A proposed granular drain design band is presented in the current study.

Thesis (M.A.)--Miami University, Dept. of Geography, 2009. / Title from first page of PDF document. Includes bibliographical references (p. 111-124).

Os condutores horizontais dos sistemas de coleta de esgotos sanitários, no Brasil e em quase todos os países do mundo, tem sido dimensionados considerando-se o escoamento em regime permanente, o que na realidade não ocorre. Sabendo-se que o escoamento no interior destes condutores acontece em regime não permanente, caracterizado pelo movimento de ondas, devido a aleatoriedade de uso dos aparelhos. Neste trabalho, apresentamos o estudo do escoamento não permanente, verificado, nos ramais e coletores dos sistemas de coleta de esgotos sanitários de edifícios residenciais. As equações diferenciais da continuidade e da quantidade de movimento, que regem este escoamento, são resolvidas pelo método das características. Apresentamos, também, os resultados e análise de várias simulações do programa de computador desenvolvido com base no método das características pelo professor Swaffield, da Universidade Heriot-Watt, Escócia. Os dados de entrada para estas simulações foram obtidos a partir de ensaios laboratoriais de algumas configurações de ambientes sanitários brasileiros, também apresentados neste trabalho. Os resultados destas simulações mostram que a consideração do escoamento em regime não permanente, possibilita a redução dos diâmetros dos ramais e coletores, e consequentemente, a redução dos custos destes sistemas. / Usually horizontal waste pipes of Building Drainage Systems, in Brazil and almost all of countries in the world, are dimensioned considering a steady flow, that does not exist. The random use of the sanitary appliances connected to the Drainage Systems of the building is the responsible for the unsteady flow. We present a study of unsteady partially filled pipeflow for drains and sewers. The differential equations of continuity and motion are solved via the method of characteristics. We present, also, the results and analysis of several simulations using a computational program developed by Prof. Swaffield-Heriot - Watt University, Scotland. The data entry were obtained through laboratorial tests which considered brazilian bathroom configurations, presented in this work. The results show us that the consideration of unsteady flow conduct to the reductions of horizontal waste pipes diameters, consequently to the reduction of the Building Drainage Systems costs.