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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.
21

Effect of design and dosing regime on the treatment performance of vertical flow constructed wetlands

Olsson, Linda January 2011 (has links)
Vertical flow constructed wetlands (VF CWs) are becoming increasingly popular for onsite wastewater treatment due to their high oxygen transfer capacity and high nitrification rates. However, there are still some question marks regarding (1) how the treatment performance of VF CWs is affected by design and operational parameters, and (2) the treatment processes happening inside the wetland bed as the wastewater percolates through. In this study, we investigated the effects of filter media (coarse sand or fine gravel), dosing regime (hourly with 4 mm or bi-hourly with 8 mm) and plant presence (with or without Phragmites australis) on the  treatment performance and concentration depth profiles of pollutant removal in six pilot-scale VF CWs treating primary treated domestic wastewater. Grab samples of wastewater were collected every 2-3 weeks during 5 months and analyzed for organic matter, suspended solids, nitrogen and E. coli. We found that sand beds performed better than gravel beds for removal of all pollutants except total nitrogen, although for long term operation gravel may be less susceptible to clogging. The overall treatment performance was not affected by different dosing regimes, but the concentration depth profiles showed that smaller and more frequent doses led to more pollutant removal in the upper part of the beds. The presence of plants was moderately important for the removal of ammonium, but had no effect on other pollutants.
22

Technoeconomic evaluation of flared natural gas reduction and energy recovery using gas-to-wire scheme

Anosike, Nnamdi Benedict 11 1900 (has links)
Most mature oil reservoirs or fields tend to perform below expectations, owing to high level of associated gas production. This creates a sub-optimal performance of the oil production surface facilities; increasing oil production specific operating cost. In many scenarios oil companies flare/vent this gas. In addition to oil production constraints, associated gas flaring and venting consists an environmental disasters and economic waste. Significant steps are now being devised to utilise associated gas using different exploitation techniques. Most of the technologies requires large associated gas throughput. However, small-scale associated gas resources and non-associated natural gas reserves (commonly referred to as stranded gas or marginal field) remains largely unexploited. Thus, the objective of this thesis is to evaluate techno- economic of gas turbine engines for onsite electric power generation called gas- to-wire (GTW) using the small-scaled associated gas resources. The range of stranded flared associated gas and non-associated gas reserves considered is around 10 billion to 1 trillion standard cubic feet undergoing production decline. The gas turbine engines considered for power plant in this study are based on simple cycle or combustion turbines. Simple cycle choice of power-plant is conceived to meet certain flexibility in power plant capacity factor and availability during production decline. In addition, it represents the basic power plant module cable of being developed into other power plant types in future to meet different local energy requirements. This study developed a novel gas-to-wire techno-economic and risk analysis framework, with capability for probabilistic uncertainty analysis using Monte Carlo simulation (MCS) method. It comprises an iterative calculation of the probabilistic recoverable reserves with decline module and power plant thermodynamic performance module enabled by Turbomatch (an in-house code) and Gas Turb® software coupled with economic risk modules with @Risk® commercial software. This algorithm is a useful tool for simulating the interaction between disrupted gas production profiles induced by production decline and its effect on power plant techno-economic performance over associated gas utilization economic life. Furthermore, a divestment and make- up fuel protocol is proposed for management of gas turbine engine units to mitigate economical underperformance of power plant regime experienced due to production decline. The results show that utilization of associated gas for onsite power generation is a promising technology for converting waste to energy. Though, associated gas composition can be significant to gas turbine performance but a typical Nigerian associated gas considered is as good as a regular natural gas. The majority of capital investment risk is associated with production decline both natural and manmade. Finally, the rate of capital investment returns decreases with smaller reserves.
23

Wastewater Reuse: Comprehensive Study about Treatment System Efficiency and Potential Public Health Concerns

Park, Eunyoung January 2015 (has links)
No description available.
24

Online to Onsite - Seeding public collaborative services in Rome's library network context

Luccioni, Carlo January 2014 (has links)
The purpose of the study has been to execute an investigation on digital collaborative services, and their connections to onsite activities, throughout empirical experimentation, with a combined participatory design methodology and lab approach. The research focused on how an online platform, in addition to onsite events, could seed a public collaborative service. The chosen context for prototyping the service was the Rome’s library network, where during a phase of economic and job crisis, the library role is even more crucial, as one of the most locally active user centered services. The library wants to readdress its mediation ability towards educational activities who present an unsaturated potential, aimed at increasing users long term job potential and labour market orientation.
The workshops with local students, library staff, and local NGO, highlighted the need of an online platform in combination with onsite events, that could fill the main gaps that prevent the building of continuos relations with the users, adding a new core touchpoint will change the user experience of the current service, generating a new service flow.
The online and onsite service was tested in the month of July 2014, with 5 seminars, and a decent online participation, focusing on the main feature of the service: directly influence the service, to actively choosing its contents, the most voted events’ themes that become seminars.
The users are able to adapt the service to their personal needs, making the system modifiable, creating dialog between the users and the service, sharing many communal traits with a meta-design environment. 
The current state of the service prototype can not be considered a collaborative service, since the users can reach the role of co-designer - even if can be considered a social innovation project. However this service prototype has the potential to seed a transformation towards a public collaborative service. The user could gradually build a continuos relation to the service, as far as becoming a co-provider.
25

Technoeconomic evaluation of flared natural gas reduction and energy recovery using gas-to-wire scheme

Anosike, Nnamdi Benedict January 2013 (has links)
Most mature oil reservoirs or fields tend to perform below expectations, owing to high level of associated gas production. This creates a sub-optimal performance of the oil production surface facilities; increasing oil production specific operating cost. In many scenarios oil companies flare/vent this gas. In addition to oil production constraints, associated gas flaring and venting consists an environmental disasters and economic waste. Significant steps are now being devised to utilise associated gas using different exploitation techniques. Most of the technologies requires large associated gas throughput. However, small-scale associated gas resources and non-associated natural gas reserves (commonly referred to as stranded gas or marginal field) remains largely unexploited. Thus, the objective of this thesis is to evaluate techno- economic of gas turbine engines for onsite electric power generation called gas- to-wire (GTW) using the small-scaled associated gas resources. The range of stranded flared associated gas and non-associated gas reserves considered is around 10 billion to 1 trillion standard cubic feet undergoing production decline. The gas turbine engines considered for power plant in this study are based on simple cycle or combustion turbines. Simple cycle choice of power-plant is conceived to meet certain flexibility in power plant capacity factor and availability during production decline. In addition, it represents the basic power plant module cable of being developed into other power plant types in future to meet different local energy requirements. This study developed a novel gas-to-wire techno-economic and risk analysis framework, with capability for probabilistic uncertainty analysis using Monte Carlo simulation (MCS) method. It comprises an iterative calculation of the probabilistic recoverable reserves with decline module and power plant thermodynamic performance module enabled by Turbomatch (an in-house code) and Gas Turb® software coupled with economic risk modules with @Risk® commercial software. This algorithm is a useful tool for simulating the interaction between disrupted gas production profiles induced by production decline and its effect on power plant techno-economic performance over associated gas utilization economic life. Furthermore, a divestment and make- up fuel protocol is proposed for management of gas turbine engine units to mitigate economical underperformance of power plant regime experienced due to production decline. The results show that utilization of associated gas for onsite power generation is a promising technology for converting waste to energy. Though, associated gas composition can be significant to gas turbine performance but a typical Nigerian associated gas considered is as good as a regular natural gas. The majority of capital investment risk is associated with production decline both natural and manmade. Finally, the rate of capital investment returns decreases with smaller reserves.
26

O ensino de fundamentos de astronomia e astrofísica na modalidade a distância para alunos de graduação

Müller, Alexei Machado January 2013 (has links)
O número de cursos na modalidade a distância tem aumentado consideravelmente no mundo, porém existe um grande receio por parte de muitos que o ensino nessa modalidade tenha qualidade inferior ao apresentado na modalidade presencial. Contudo a qualidade do ensino não decorre da presença de todos os envolvidos num mesmo local, e sim da implementação de ações que facilitem o processo de aprendizagem. Esse trabalho teve como objetivo produzir um módulo didático, em hipermídia, para a disciplina de Fundamentos de Astronomia e Astrofísica, a ser ministrada na modalidade a distância aos alunos do curso de licenciatura em Física e a outros alunos interessados, vinculados à UFRGS, por meio de um ambiente virtual de aprendizagem, que tornasse possível um ensino de qualidade nessa modalidade. Com esse intuito, foi elaborada uma adaptação do hipertexto Astronomia e Astrofísica dos Professores Kepler de Souza Oliveira Filho e Maria de Fátima Oliveira Saraiva, procurando colocá-lo num formato mais adequado para a aprendizagem sem a presença do professor. Para atingir a meta de favorecer uma aprendizagem significativa ausubeliana, os conteúdos das aulas foram organizados de forma a propiciar a diferenciação progressiva e a reconciliação integradora, e no desenvolvimento das atividades propostas, a interação social vygostkyana entre os alunos, no ambiente virtual. O módulo de ensino está dividido em três áreas e contém 28 aulas no total, todas tendo a mesma estrutura básica: objetivos, introdução, desenvolvimento, resumo e atividades de fixação. Também são utilizados aplicativos (applets) de uso livre na rede e outros recursos próprios do ambiente virtual de aprendizagem tais como fóruns e questionários. O material foi aplicado no segundo semestre de 2011, 2011/2, tendo sido trabalhado com uma turma de 25 alunos matriculados. No final de cada uma das três áreas, os alunos foram submetidos a uma avaliação presencial, sendo a nota de cada área estabelecida a partir de uma composição entre as participações nas atividades propostas no ambiente virtual e na prova presencial. A média final foi calculada pela média aritmética das notas de cada área. Os resultados foram bastante satisfatórios do ponto de vista de desempenho e aproveitamento dos alunos participantes, mas não corresponderam à expectativa de diminuição da taxa de abandono da disciplina. O mesmo material, com algumas melhorias, foi reaplicado no primeiro semestre de 2012, com resultados semelhantes aos de 2011/2. Novamente, os alunos que se dedicaram ao estudo conseguiram ter na modalidade a distância um aproveitamento tão bom quanto os alunos dedicados das turmas presenciais; no entanto, o taxa de abandono, principalmente por parte dos alunos de Licenciatura Noturna, permaneceu alta. / The number of online distance learning courses has greatly increased worldwide, but there is a great concern shared by many that this type of teaching modality offers lower quality than that offered by onsite courses. However, we understand that the quality of education does not follow from the onsite presence of all participants, but from the implementation of actions that facilitate the learning process. This study aims at producing a high quality hypermedia didactic module to the online teaching of the Fundamentals of Astronomy and Astrophysics to the undergraduate students and students alike who are linked to UFRGS through a virtual environment. In addition, to achieve such goal, an adaptation of the Astronomy and Astrophysics hypertext by Dr. Kepler Oliveira de Souza Filho and Dr. Maria de Fatima Oliveira Saraiva was accomplished. Also, to carry out the Ausubelian meaningful teaching method class contents were organized in a way to encourage the progressive differentiation and integrative reconciliation of Ausubel. Furthermore, the Vygostkyan social interaction method was applied to the development of activities among the distance learning students. The teaching module is divided into three areas and contains 28 lessons in total, all having the same basic structure: objectives, introduction, development, summary and fixation activities. Freeware applets and other virtual learning environment resources such as forums and questionnaires were used. The teaching resources were applied in the second semester of 2011, 2011/2, to a class of 25 enrolled students. At the end of each of the three areas the students were submitted to an on-site assessment: the score of each area was established from a composition between the participation in the online proposed activities and the test applied. The final average was calculated as the arithmetic average of the ratings for each area. The results were quite satisfactory from the point of view of performance and progress of the participating students, but did not correspond to the expected decrease in the class drop-out rate. The same class material, with some improvements, was reapplied in the first semester of 2012, with results similar to those of 2011/2. Again, dedicated students benefited from the distance learning course as much as the best students of the onsite course. Nonetheless, the drop-out rate, mainly by evening class undergraduate students, remained high.
27

O ensino de fundamentos de astronomia e astrofísica na modalidade a distância para alunos de graduação

Müller, Alexei Machado January 2013 (has links)
O número de cursos na modalidade a distância tem aumentado consideravelmente no mundo, porém existe um grande receio por parte de muitos que o ensino nessa modalidade tenha qualidade inferior ao apresentado na modalidade presencial. Contudo a qualidade do ensino não decorre da presença de todos os envolvidos num mesmo local, e sim da implementação de ações que facilitem o processo de aprendizagem. Esse trabalho teve como objetivo produzir um módulo didático, em hipermídia, para a disciplina de Fundamentos de Astronomia e Astrofísica, a ser ministrada na modalidade a distância aos alunos do curso de licenciatura em Física e a outros alunos interessados, vinculados à UFRGS, por meio de um ambiente virtual de aprendizagem, que tornasse possível um ensino de qualidade nessa modalidade. Com esse intuito, foi elaborada uma adaptação do hipertexto Astronomia e Astrofísica dos Professores Kepler de Souza Oliveira Filho e Maria de Fátima Oliveira Saraiva, procurando colocá-lo num formato mais adequado para a aprendizagem sem a presença do professor. Para atingir a meta de favorecer uma aprendizagem significativa ausubeliana, os conteúdos das aulas foram organizados de forma a propiciar a diferenciação progressiva e a reconciliação integradora, e no desenvolvimento das atividades propostas, a interação social vygostkyana entre os alunos, no ambiente virtual. O módulo de ensino está dividido em três áreas e contém 28 aulas no total, todas tendo a mesma estrutura básica: objetivos, introdução, desenvolvimento, resumo e atividades de fixação. Também são utilizados aplicativos (applets) de uso livre na rede e outros recursos próprios do ambiente virtual de aprendizagem tais como fóruns e questionários. O material foi aplicado no segundo semestre de 2011, 2011/2, tendo sido trabalhado com uma turma de 25 alunos matriculados. No final de cada uma das três áreas, os alunos foram submetidos a uma avaliação presencial, sendo a nota de cada área estabelecida a partir de uma composição entre as participações nas atividades propostas no ambiente virtual e na prova presencial. A média final foi calculada pela média aritmética das notas de cada área. Os resultados foram bastante satisfatórios do ponto de vista de desempenho e aproveitamento dos alunos participantes, mas não corresponderam à expectativa de diminuição da taxa de abandono da disciplina. O mesmo material, com algumas melhorias, foi reaplicado no primeiro semestre de 2012, com resultados semelhantes aos de 2011/2. Novamente, os alunos que se dedicaram ao estudo conseguiram ter na modalidade a distância um aproveitamento tão bom quanto os alunos dedicados das turmas presenciais; no entanto, o taxa de abandono, principalmente por parte dos alunos de Licenciatura Noturna, permaneceu alta. / The number of online distance learning courses has greatly increased worldwide, but there is a great concern shared by many that this type of teaching modality offers lower quality than that offered by onsite courses. However, we understand that the quality of education does not follow from the onsite presence of all participants, but from the implementation of actions that facilitate the learning process. This study aims at producing a high quality hypermedia didactic module to the online teaching of the Fundamentals of Astronomy and Astrophysics to the undergraduate students and students alike who are linked to UFRGS through a virtual environment. In addition, to achieve such goal, an adaptation of the Astronomy and Astrophysics hypertext by Dr. Kepler Oliveira de Souza Filho and Dr. Maria de Fatima Oliveira Saraiva was accomplished. Also, to carry out the Ausubelian meaningful teaching method class contents were organized in a way to encourage the progressive differentiation and integrative reconciliation of Ausubel. Furthermore, the Vygostkyan social interaction method was applied to the development of activities among the distance learning students. The teaching module is divided into three areas and contains 28 lessons in total, all having the same basic structure: objectives, introduction, development, summary and fixation activities. Freeware applets and other virtual learning environment resources such as forums and questionnaires were used. The teaching resources were applied in the second semester of 2011, 2011/2, to a class of 25 enrolled students. At the end of each of the three areas the students were submitted to an on-site assessment: the score of each area was established from a composition between the participation in the online proposed activities and the test applied. The final average was calculated as the arithmetic average of the ratings for each area. The results were quite satisfactory from the point of view of performance and progress of the participating students, but did not correspond to the expected decrease in the class drop-out rate. The same class material, with some improvements, was reapplied in the first semester of 2012, with results similar to those of 2011/2. Again, dedicated students benefited from the distance learning course as much as the best students of the onsite course. Nonetheless, the drop-out rate, mainly by evening class undergraduate students, remained high.
28

O ensino de fundamentos de astronomia e astrofísica na modalidade a distância para alunos de graduação

Müller, Alexei Machado January 2013 (has links)
O número de cursos na modalidade a distância tem aumentado consideravelmente no mundo, porém existe um grande receio por parte de muitos que o ensino nessa modalidade tenha qualidade inferior ao apresentado na modalidade presencial. Contudo a qualidade do ensino não decorre da presença de todos os envolvidos num mesmo local, e sim da implementação de ações que facilitem o processo de aprendizagem. Esse trabalho teve como objetivo produzir um módulo didático, em hipermídia, para a disciplina de Fundamentos de Astronomia e Astrofísica, a ser ministrada na modalidade a distância aos alunos do curso de licenciatura em Física e a outros alunos interessados, vinculados à UFRGS, por meio de um ambiente virtual de aprendizagem, que tornasse possível um ensino de qualidade nessa modalidade. Com esse intuito, foi elaborada uma adaptação do hipertexto Astronomia e Astrofísica dos Professores Kepler de Souza Oliveira Filho e Maria de Fátima Oliveira Saraiva, procurando colocá-lo num formato mais adequado para a aprendizagem sem a presença do professor. Para atingir a meta de favorecer uma aprendizagem significativa ausubeliana, os conteúdos das aulas foram organizados de forma a propiciar a diferenciação progressiva e a reconciliação integradora, e no desenvolvimento das atividades propostas, a interação social vygostkyana entre os alunos, no ambiente virtual. O módulo de ensino está dividido em três áreas e contém 28 aulas no total, todas tendo a mesma estrutura básica: objetivos, introdução, desenvolvimento, resumo e atividades de fixação. Também são utilizados aplicativos (applets) de uso livre na rede e outros recursos próprios do ambiente virtual de aprendizagem tais como fóruns e questionários. O material foi aplicado no segundo semestre de 2011, 2011/2, tendo sido trabalhado com uma turma de 25 alunos matriculados. No final de cada uma das três áreas, os alunos foram submetidos a uma avaliação presencial, sendo a nota de cada área estabelecida a partir de uma composição entre as participações nas atividades propostas no ambiente virtual e na prova presencial. A média final foi calculada pela média aritmética das notas de cada área. Os resultados foram bastante satisfatórios do ponto de vista de desempenho e aproveitamento dos alunos participantes, mas não corresponderam à expectativa de diminuição da taxa de abandono da disciplina. O mesmo material, com algumas melhorias, foi reaplicado no primeiro semestre de 2012, com resultados semelhantes aos de 2011/2. Novamente, os alunos que se dedicaram ao estudo conseguiram ter na modalidade a distância um aproveitamento tão bom quanto os alunos dedicados das turmas presenciais; no entanto, o taxa de abandono, principalmente por parte dos alunos de Licenciatura Noturna, permaneceu alta. / The number of online distance learning courses has greatly increased worldwide, but there is a great concern shared by many that this type of teaching modality offers lower quality than that offered by onsite courses. However, we understand that the quality of education does not follow from the onsite presence of all participants, but from the implementation of actions that facilitate the learning process. This study aims at producing a high quality hypermedia didactic module to the online teaching of the Fundamentals of Astronomy and Astrophysics to the undergraduate students and students alike who are linked to UFRGS through a virtual environment. In addition, to achieve such goal, an adaptation of the Astronomy and Astrophysics hypertext by Dr. Kepler Oliveira de Souza Filho and Dr. Maria de Fatima Oliveira Saraiva was accomplished. Also, to carry out the Ausubelian meaningful teaching method class contents were organized in a way to encourage the progressive differentiation and integrative reconciliation of Ausubel. Furthermore, the Vygostkyan social interaction method was applied to the development of activities among the distance learning students. The teaching module is divided into three areas and contains 28 lessons in total, all having the same basic structure: objectives, introduction, development, summary and fixation activities. Freeware applets and other virtual learning environment resources such as forums and questionnaires were used. The teaching resources were applied in the second semester of 2011, 2011/2, to a class of 25 enrolled students. At the end of each of the three areas the students were submitted to an on-site assessment: the score of each area was established from a composition between the participation in the online proposed activities and the test applied. The final average was calculated as the arithmetic average of the ratings for each area. The results were quite satisfactory from the point of view of performance and progress of the participating students, but did not correspond to the expected decrease in the class drop-out rate. The same class material, with some improvements, was reapplied in the first semester of 2012, with results similar to those of 2011/2. Again, dedicated students benefited from the distance learning course as much as the best students of the onsite course. Nonetheless, the drop-out rate, mainly by evening class undergraduate students, remained high.
29

Attitudinal, Economic and Technological Approaches to Wastewater Management in Rural Ohio

Vedachalam, Sridhar 25 July 2011 (has links)
No description available.
30

The Online and the Onsite Holocaust Museum Exhibition as an Informational Resource

Lincoln, Margaret L. 12 1900 (has links)
Museums today provide learning-rich experiences and quality informational resources through both physical and virtual environments. This study examined a Holocaust Museum traveling exhibition, Life in Shadows: Hidden Children and the Holocaust that was on display at the Art Center of Battle Creek, Michigan in fall 2005. The purpose of this mixed methods study was to assess the informational value of a Holocaust Museum exhibition in its onsite vs. online format by converging quantitative and qualitative data. Participants in the study included six eighth grade language arts classes who viewed various combinations or scenarios of the onsite and online Life in Shadows. Using student responses to questions in an online exhibition survey, an analysis of variance was performed to determine which scenario visit promotes the greatest content learning. Using student responses to additional questions on the same survey, data were analyzed qualitatively to discover the impact on students of each scenario visit. By means of an emotional empathy test, data were analyzed to determine differences among student response according to scenario visit. A principal finding of the study (supporting Falk and Dierking's contextual model of learning) was that the use of the online exhibition provided a source of prior orientation and functioned as an advanced organizer for students who subsequently viewed the onsite exhibition. Students who viewed the online exhibition received higher topic assessment scores. Students in each scenario visit gave positive exhibition feedback and evidence of emotional empathy. Further longitudinal studies in museum informatics and Holocaust education involving a more diverse population are needed. Of particular importance would be research focusing on using museum exhibitions and Web-based technology in a compelling manner so that students can continue to hear the words of survivors who themselves bear witness and give voice to silenced victims. When perpetuity of access to informational resources is assured, future generations will continue to be connected to the primary documents of history and cultural heritage.

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