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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.
81

Urinary 1-hydroxypyrene in nonsmokers : a biomarker for coke smoke exposure and general urban PAH exposure

Han, In-Kyu. January 2008 (has links)
Thesis (Ph. D.)--Rutgers University, 2008. / "Graduate Program in Public Health." Includes bibliographical references.
82

Virtual and augmented reality simulation of Chattanooga Creek

Vadlamudi, Sirisha. January 2003 (has links) (PDF)
Thesis (M.S.)--University of Tennessee, Knoxville, 2003. / Title from title page screen (viewed Mar. 25,2004). Thesis advisor: Daniel B. Koch. Document formatted into pages (viii, 113 p. : ill.). Vita. Includes bibliographical references (p. 58-61).
83

Development Of Reclamation Substrates For Alberta Oil Sands Using Mature Fine Tailings And Coke

Luna-Wolter, Gabriela L. Unknown Date
No description available.
84

Evolving Newspapers & the Shaping of an Extradition: Jamaica on the Cusp of Change

Lewis, Ghislaine Leslyn January 2014 (has links)
The evolution and impact of journalism in the developing world remains largely under-explored, especially in the Caribbean. This case study explores the role of the 21st century daily newspaper in Jamaica, during a period where the country endured its first widespread national crisis in almost three decades. This thesis deconstructs the coverage of Jamaica’s two daily newspapers and the role of civil society during the nine months prior to the extradition of alleged transnational drug dealer Christopher Coke to the United States. The extradition coverage of Coke, whom the American government deemed, one of the most wanted men in the world, highlighted growing concerns about the island’s diplomacy and its place in the global environment. It gave the news media an opportunity to focus on incidences of corruption, party-garrison clientelistic relationships and facilitate debates about good governance and a new vision for the island. In the aftermath of the Coke extradition, there have been questions about influence and who played what roles in the resolution of the crisis. This thesis considers the influence of the media and of wider civil society activism, specifically the way the newspapers and civic organizations shaped the extradition, opened a space for dialogue and created a shift in the nature of media/government relations on the island. An in-depth content analysis of the newspaper coverage leading up to the extradition forms the empirical basis for study. This is supplemented by interviews with journalists, academics and civic agents whose voices helped shape the Coke debate in the newspapers. This crisis provided a unique opportunity to assess the news agenda on the island along with the perspectives of community voices as they engaged to influence a peaceful resolution. The newspaper analysis of the extradition highlighted the political and social complexity of the island, in particular, the rampant political corruption, extreme social inequality, commonplace civil disobedience and criminality. The extradition revealed that there were obstacles to the cohesion of civil society groups in Jamaica. They were hampered by class and income disparities, political allegiances and questions of faith. These underlying concepts, along with newsroom culture, press-politics relationships, self-censorship, newspaper patronage, education, economic structures, and cultural identity can all be understood not by their individual meanings but as ways in which power is shaping the socio-political landscape of the island. The newspaper coverage of the extradition battle also exposed flaws in the island’s political and social fabric, this elevated government’s predicament from a routine extradition warrant to an armed conflict. This thesis reinforces the role of daily newspapers in ensuring governmental transparency and providing a space that facilitates differing views which ultimately allows democracy to work. The findings from the thesis contribute to an understanding of journalism outside of the context of the United States/ United Kingdom. It showed that in the Caribbean and especially Jamaica special considerations must be made for how socio-cultural factors impact newspaper journalism.
85

The quality of binder-filler interfaces in carbon electrodes

Ogden, Gary N. January 1995 (has links)
The aims of this research project were to identify and classify the binder-filler interfaces formed in carbon electrodes and to determine the effects of the interfacial quality on important electrode properties. The effects of raw materials and some fabrication process variables on interfacial characteristics and quality of laboratory produced test electrodes were also studied, and the development of binder-filler interfaces during the carbonisation process followed. Electrode quality was assessed by measurement of density, electrical resistivity and tensile strength. Pore structural data were also obtained by using a computerised image analysis system allied to an optical microscope. Interface quality data were obtained by examining etched surfaces in a scanning electron microscope and classifying the binder-filler interface observed into one of five categories. The category depending on the extent of contact between the binder and filler. Accordingly, test electrodes were produced from combinations of four filler carbons, comprising three grades of calcined petroleum coke and an electro-calcined anthracite, and four coal-tar binder pitches which varied in the type and quantity of insoluble matter content. Examination of these test electrodes showed that the nature of the filler carbon used had a dominant influence on the quality of the interface formed, as assessed by this technique. A combination of one filler carbon and one binder pitch was used to study the effects of some fabrication process variables. These were pitch content and, mixing time and temperature. Of these process variables, pitch content and mixing temperature were found to have the major effects on the binder-filler interface and electrode quality. Investigation of the development of the binder-filler interfaces during the carbonisation process showed three distinct zones of interface development and transformation. These zones were associated with three temperature dependent mechanisms; thermal stress relaxation between 200-350 degrees C, volatile gas evolution from coal-tar pitch decompositionb etween3 50-600 degrees C and stresses induced by thermal contraction of the binder phase between 600-1000 degrees C.
86

Bulk density and angle of repose of coal

Liu, Chang, Materials Science & Engineering, Faculty of Science, UNSW January 2007 (has links)
This thesis reports a study on the effects of size distribution, moisture content and oil addition on bulk density and angle of repose of coal. The experimental work includes four stages. The first stage is to develop reliable experimental techniques. The results confirm that ASTM cubic foot test is reliable for measurement of bulk density and angle of repose if properly operated, although the latter is better measured in a piling process. Stages 2 and 3 are to investigate the effects of size distribution by using -3.55mm% for stage 2 and mean size do.s for stage 3, water content and oil addition on bulk density and angle of repose of coal. For each of them, empirical equations are formulated to predict bulk density and angle of repose. The results indicate that the fraction -3.55mm cutting size in stage 2 does not affect bulk density significantly, while the increase of do.s decreases bulk density to a minimum and then increases. Particle size distribution does not affect angle of repose much. The increase of moisture content decreases bulk density and increases angle of repose significantly. The increase of oil addition increases bulk density while decreases angle of repose significantly. The correlation between bulk density and angle of repose can also be observed: the higher bulk density, the lower angle of repose. There are other variables affecting bulk density and angle of repose. They include oil type, absorption time discharging height and external loading. Their effects on bulk density and angle of repose are quantified in stage 4. The results suggest that, a higher discharging position or larger external loading increase bulk density significantly. Angle of repose decreases when increase the height of discharging position. Diesel oil performed better than waste oil addition in terms of bulk density enhancement. For most of the cases examined, bulk density and angle of repose become stable after ~24 hours oil absorption time.
87

Strategic management of an energy resource: Queensland's coking coals

Koerner, Richard Unknown Date (has links)
No description available.
88

Strategic management of an energy resource: Queensland's coking coals

Koerner, Richard Unknown Date (has links)
No description available.
89

Catalytic graphitisation of refcoal cokes

Nyathi, Mhlwazi Solomon January 1900 (has links)
Thesis (MSc.(Chemistry))--University of Pretoria, 2008. / Includes bibliographical references.
90

Monitoração eletrônica da incrustação de coque no processamento do petróleo

Bombardelli, Clovis 2010 October 1914 (has links)
A incrustação causada pelo coque é um sério problema na indústria do petróleo, principalmente, nos equipamentos que operam em altas temperaturas. Neste trabalho apresenta-se um estudo para demonstrar a possibilidade do emprego da incrustação do coque como um elemento transdutor para compor um sensor tipo resistivo, para fornecer um sinal elétrico representativo do crescimento e do envelhecimento local da própria incrustração. Para a demonstração, procederam-se duas etapas de experimentos com óleos pesados do petróleo e amostras de incrustação de coque originadas por esses óleos na indústria. Os experimentos mostraram bons resultados, mas também indicaram que o sinal combina a condutividade do óleo e o da incrustação. O coque produzido nos experimentos apresentou-se como grânulos soltos não aderentes e eletricamente desconectados entre si. Verificou-se que o sinal obtido durante o craqueamento térmico em regime de batelada apresenta três regiões distintas: no início o material reage com uma cinética de primeira ordem; na região intermediária, ocorre separação do fluído em duas fases líquidas e finalmente, na terceira região, ocorre a deposição do coque sólido, porém imerso em óleo com elevada resistência elétrica, fornecendo um sinal muito mais alto que o valor inicial apresentado pelo óleo. Entretanto, craqueamentos térmicos sucessivos sobre o leito de coque inicial mostrou progressivas reduções nos valores das leituras, indicando a tendência a ser adquirida com o envelhecimento do coque, de se agregar em uma grande estrutura carbonácea de baixa resistividade elétrica. Alternativamente, para confirmar, mediu-se a resistência elétrica em amostras de incrustação verdadeiras usando-se as mesmas condições empregadas nos óleos. Os resultados mostraram uma resistividade aproximadamente 50 vezes menor que a dos óleos. Ensaios de craqueamento sucessivos de óleos sobre estas incrustações mantêm praticamente constante a resistência elétrica obtida como leitura, confirmando que o aumento da condutividade se deve mais ao envelhecimento e cimentação dos grânulos de coque do que o crescimento da incrustação. Os ensaios também mostraram que uma vez que a incrustação adquire uma resistividade elétrica menor que a do óleo, o sinal torna-se mais representativo da incrustação. O sinal então, se associado a um método de ajuste adequado, fornece a velocidade de crescimento da camada incrustada que pode ser usada como parâmetro de controle ao processo industrial para minimizar o problema da incrustação pelo coque. / The coke fouling is a serious problem in the oil industry, mainly in equipment operating at high temperatures. This work presents a study to demonstrate the possibility of using the inlay of the coke as a transducer element to form a resistive sensor type, to provide an electrical signal representative of the growth and aging of the local self inlay. In order to demonstrate this, two categories of experiments have been carried out with two heavy oils fractions and two samples of real fouling coke incrustation originated by these oils in the industry. The experiments show good results, but also indicate that the signal combines both oil and incrustations conductivity. The coke produced during the experiment haad non-adherent loose granules that were electrically disconnected between them. It was verified that the signal obtained during the batch controlled thermal cracking shows three distinct regions: at first, the material reacts within a first-order kinetic rate; at the intermediate region, fluid separation happens in two liquid phases and, finally, at the third region, solid coke deposition occurs, though immersed in a high electric resistivity oil, providing a much higher signal than the initial value presented by the oil. However, sucessive thermal cracking on the initial bed of coke showed progressive reductions in the values of the readings, indicating the tendency to be acquired by the aging of coke, to aggregate in a large structure of carbonaceous material with low electrical resistivity. Alternatively, to confirm, was measured the electrical resistance in samples of real inlay using the same conditions employed in the oils. These have showed a resistivity approximately 50 times smaller than the one for the oils. Testing of sucessive oil cracking on these inlays remain practically constant the electric resistance obtained as reading, confirming that the increase in conductivity is due more to the aging and cementation of grains of coke than the growth of the inlay itself. The tests also showed that once the encrustation acquires a resistivity lower than of the oil, the signal becomes more meaningful and representative of the inlay. The signal, if is associated with an appropriate adjustment method, give the rate of growth of the embedded layer that can be used as a control parameter for the industrial process to minimize the problem of fouling by coke.

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