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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.
411

Dynamics of technological innovation systems : the case of biomass energy /

Negro, Simona O. January 2007 (has links)
Thesis (Ph. D.)--Utrecht University, 2007. / "This publication has been submitted as a Ph. D. thesis for the award of the degree of Doctor at Utrecht University, the Netherlands, 16 February 2007"--T.p. verso. Vita. Includes bibliographical references (p. 131-141).
412

none

Lin, Ming-Hsien 13 August 2007 (has links)
Abstract That greenhouse gas (GHG) emission causes ¡§Global Warming¡¨ is a human common problem today in the earth. The GHG emission will gradually promote our weather temperature and change which we must pay for a lot. For example, the warming temperature will dissolve icebergs, that it will elevate the sea level. Also, our land area will decrease. If climate zones were shifted, it would be possible to initiate some animals migrate. In the worse case, our living space will be squeezed and some special diseases will be spread out¡Ketc. In view of environmental protection awareness in every country, we must face the problem and crisis which comes from ¡§Global Warming¡¨ and ¡§Heating Pollution¡¨. In June of 1992, there was a meeting in Rio of Brazil. All representatives who comes from 153 different countries sign an agreement ¡V the United Nations Framework Convention on Climate Change (UNFCCC). They try to stabilize greenhouse gas concentrations at a level that would prevent dangerous interference with the climate and environmental system. To achieve this goal, the Kyoto Protocol was adopted on COP3 in December 1997 to place legally binding limits on GHG emissions. This Protocol norms 38 countries and European Union. In June 2007, the Group of Eight (G8) have reached a consensus and expect in year 2050, CO2 emissions can be reduced to the half of current emissions. We can see that, every country is vigorous to look for alternative energy that eliminates the environment destroyed and saves the earth resources. For example, Solar Energy, Water Energy, Wind Energy, Biomass Energy, Ocean Energy and Geothermal Energy¡Ketc. Those are gradually developed and applied in our daily life. My research is focus on the LED applications based on the substitution of traditional lighting. Actually, LED has all advantage of the energy saving, eco-lighting and economy of scale. How to use this alternative lighting is of great urgency and the major topic in light source manufacturers. For example, if America can replace their 55% white heat bulbs and 55% fluorescent lamps by LED before 2010, they can save 35 billion US dollars every year. For Japan, if they replace 100% white heat bulbs, they can save one to two of Nuclear Power Plants. Also, they can save above 100 million of gasoline every year. As to Taiwan official estimation, we can save 11 billion electricity degrees every year when we replace 25% white heat bulbs and 100% fluorescent lamps. That electric power is approximate to save one Nuclear Power Plant and 50 million of gasoline every year. According to the data above, the population of LED will give us a lot of eco-benefits. My report leans on researching and treating LED. Then, I take one step ahead to demonstrate how important it is to apply LED on our human light source and the effects of earth environment. Keywords: Greenhouse Gas (GHG) Global Warming United Nations Framework Convention on Climate Change (UNFCCC) Kyoto Protocol Biomass Energy LED - Light Emitting Diode (display)
413

Stress corrosion cracking of 316L austenitic stainless steel in high temperature ethanol/water environments

Gulbrandsen, Stephani 06 1900 (has links)
There has been an increase in the production of bio-fuels. Organosolv delignification, high temperature ethanol/water environments, can be used to separate lignin, cellulose, and hemicelluloses in the bio-mass for bio-fuel production. These environments have been shown to induce stress corrosion cracking (SCC) in 316L stainless steel. Previous research has been done in mixed solvent environments at room temperature to understand SCC for stainless steels, but little is known about the behavior in high temperature environments. Simulated organosolv delignification environments were studied, varying water content, temperature, pHe, and Cl- content to understand how these constituents impact SCC. In order for SCC to occur in 316L, there needs to be between 10 and 90 volume % water and the environment needs to be at a temperature around 200°C. Once these two conditions are met, the environment needs to either have pHe < 4 or have more than 10 ppm Cl-. These threshold conditions are based on the organosolv delignification simulated environments tested. SCC severity was seen to increase as water content, temperature, and Cl- content increased and as pHe decreased. To prevent failure of industrial vessels encountering organosolv delignification environments, care needs to be taken to monitor and adjust the constituents to prevent SCC.
414

Decentralized Sustainable Energy Planning For Tumkur District, India

Hiremath, Rahul B 01 1900 (has links)
The energy-planning involves finding a set of sources and conversion devices so as to meet the energy requirements/demands of all the activities in an optimal manner. This could occur at centralized or decentralized level. The current pattern of commercial energy oriented development, particularly focused on fossil fuels and centralized electricity, has resulted in inequities, external debt and environmental degradation. The current status is largely a result of adoption of centralized energy planning (CEP), which ignores the energy needs of rural areas and the poor and has further contributed to environmental degradation due to fossil fuel consumption and forest degradation. CEP does not pay attention to the variations in socio-economic and ecological factors of a region, which influence success of any intervention. Decentralized energy planning (DEP) provides an opportunity to address the energy needs of poor as well as promote efficient utilization of resources. The DEP mechanism takes into account various available resources and demands in a region. DEP, in the Indian context, could be at several scales namely district, block, panchayats (cluster of villages) and village level. Energy planning at the village level is the lowest level of the application of decentralized planning principle. A village constitutes a cluster of households with distinct geographic boundary consisting of settlement, agricultural land, water bodies and any other land category, in most parts of India. Further, the village level plans must be prepared within the limits set by a panchayat, a block or a district level plans, for the sum total of various village plans must correspond to a panchayat (local council), block (or taluka), or district level plan. A panchayat is the lowest administrative unit consisting of a cluster of villages and an elected body to administer developmental activities. A block (or taluka) consists of a cluster of panchayats and a district consists of a cluster of blocks. The main hypothesis for this study is that centralized energy planning has lead to excessive dependence on fossil fuels and import of petroleum, leading to concerns on environment and energy security and finally neglect of the energy needs of the rural communities and poor in particular. DEP could meet the local energy needs particularly in rural areas, protect environment and promote a self reliant and sustainable energy path. In this study, methodology for adopting energy planning from grassroot or village to district level is explored. The study adopts and compares the DEP approach of moving from village (Ungra), to panchayat (Yedavani), to block (Kunigal) and finally to district (Tumkur) level. Aims and objectives of research . • To review energy planning approaches adopted in India . • To evaluate models and methods for DEP at different scales; Village, Panchayat, District and State levels . • To develop a sustainable and decentralized energy planning approach . • To analyze the sustainable decentralized planning approach using multiple objective goal programming model and develop sustainable energy mix for meeting energy needs at village, panchayat, block and district level . • To assess the implications of sustainable and decentralized energy planning from the context of socio-economic and environmental concerns. The central theme of the research work is to prepare an optimized area-based decentralized energy plan to meet the energy needs, incorporating all potential alternate energy sources and end-use devices at least-cost to the economy and environment. One of the environmental goals addressed is to minimize or avoid CO2 emissions to address climate change. Study area selected for DEP is Tumkur district of Karnataka state, India and the DEP is carried out for the year 2005 and 2020. Advanced operation research technique, goal programming, is used to solve the large and complicated energy system problem having multiple conflicting goals.
415

Effect of phosphorous poisoning on catalytic cracking of lipids for green diesel production

Dufreche, Stephen Thomas, January 2008 (has links)
Thesis (Ph.D.)--Mississippi State University. Dave C. Swalm School of Chemical Engineering. / Title from title screen. Includes bibliographical references.
416

Oxidation of lipids in a supercritical-fluid medium

Sparks, Darrell Lynn, January 2008 (has links)
Thesis (Ph.D.)--Mississippi State University. Dave C. Swalm School of Chemical Engineering. / Title from title screen. Includes bibliographical references.
417

Evaluation of the acceptability, impact and feasibility of biogas digesters in rural Maphephetheni, KwaZulu-Natal.

Sibisi, Ncamisile Teressa. January 2003 (has links)
Biogas has the potential to provide energy to communities, especially those where grid electrification will not be installed for a long time and who experience problems in accessing energy resources. The purpose of this study was to investigate whether biogas technology could provide households and a school with an acceptable, affordable, efficient, and sustainable alternative energy resource, thereby providing opportunities for cost savings, reduction of the labour burden and income generation. Three case studies were selected, two households and Myeka High School in rural Maphephetheni. Maphephetheni is situated approximately 80 km west of Durban and is characterised by the lack of grid electrification. The two households selected as case studies were both using firewood and paraffin for thermal energy. Collection of firewood was a tiresome burden to women and paraffin was expensive to purchase. The third case study, Myeka High School was using solar energy and LP gas to support its energy needs. Biogas digesters were donated to the two households and the school. Data before and after installation of biogas was collected through questionnaires, informal interviews and observations. Monitoring and evaluation of the case studies was carried out. Results collected revealed that biogas was an acceptable source of energy because the household and school equipped with the floating dome biogas digesters accepted cooking on biogas while the household used the fertiliser from biogas on their crops. However it was not affordable both to the household and the school because in the household income did not allow for its purchase while savings on energy expenditure from both the school and household could not offset the cost in the six years estimated by the engineer but it would take 11 years. Biogas was found to be efficient and sustainable provided proper management was available. Although income generation opportunities were not fully utilised, there was an opportunity for income generation through the biogas provided there was encouragement, support and markets available. Recommendations are that government policy should provide for training of stakeholders on proper management techniques. Government or organisations involved with biogas energy could do this, as well as provide an extension service for the dissemination of biogas and other renewable energy information. However, government policy should as in other countries provide for subsidies, risk underwritten bank loans or tax incentives to manufacturers. / Thesis (M.Soc.Sc.)-University of Natal, Pietermaritzburg, 2003.
418

Ozone maxima off the East Coast of South Africa : the role of biomass burning.

Pillay, Yogesveri. January 1993 (has links)
No abstract available. / Thesis (M.Sc.)-University of Natal, Durban, 1993.
419

The dynamics of microphytobenthos in the Mdloti and Mhlanga estuaries, Kwazulu-Natal.

Iyer, Kogilam. January 2004 (has links)
Microphytobenthos (MPB) generally dominates total autotrophic biomass in temporarily open/closed estuaries (TOCEs) of South Africa. A comparative study of MPB biomass was undertaken in two KwaZulu-Natal TOCEs, the Mdloti and the Mhlanga. Both estuaries receive different volumes of treated sewage waters. The Mdloti receives 8 ML.d-1, while the Mhlanga receives 20 ML.d-1, resulting in a capping flow of 0.092 and 0.23 m3.s-1, respectively. Through these effluents, eutrophication is enhanced and periods of mouth opening are also increased and prolonged, particularly at the Mhlanga. The aim of this study was to investigate fluctuations in MPB biomass in the Mdloti and the Mhlanga systems, with emphasis on freshwater flow and the alternation of closed and open phases. Sediment samples for MPB biomass were collected on a monthly basis, between March 2002 and March 2003, in the lower (mouth), middle, and upper (head) reaches of the two estuaries. MPB biomass ranged from 1.33 to 391 mg chI a m-2 and from 1.7 to 313 mg chI a m-2 in the Mdloti and the Mhlanga, respectively. A I-way ANOVA revealed no significant differences in MPB chI a concentrations between the two estuaries for the entire data set (Fl, 76 =1.48, P > 0.05). At the Mdloti, MPB biomass varied considerably, with values ranging from 1.33 to 131 mg chI a m-2 during the open phase, and from 18 to 391 mg chI a m-2 during the closed phase. A Mann-Whitney U test confirmed the high significance of these differences between open and closed phases (U= 29, P < 0.001). At the Mhlanga, MPB biomass ranged from 7.0 to 313 mg chI a m-2 during the open phase, and from 1.7 to 267 mg chI a m-2 during the closed phase. Unlike what was observed at the Mdloti, the higher MPB values at the Mhlanga were not always associated with the closed mouth state. In relation to key physico-chemical and biological factors, grazing pressure exerted by the zooplankton community appeared to have played a major role in controlling MPB biomass. Zooplankton biomass was consistently and positively correlated to MPB biomass throughout the study period both at the Mdloti (r = 0040, P < 0.001) and at the Mhlanga (r = 0.33, p < 0.05). Unlike what was shown in previous studies, light attenuation was not significantly correlated with MPB biomass during the period ofthe study, either at the Mdloti or the Mhlanga. These results show that the opening and closing of the mouth play a key role on the MPB biomass of both estuaries. The Mdloti seems to function as a typical TOCE, with prolonged open and closed phases. The Mhlanga, on the other hand, lacks a prolonged closed phase. This, in turn, affects its entire trophic structure and functioning. / Thesis (M.Sc.)-University of KwaZulu- Natal, 2004.
420

Using algae to capture CO₂ and as a feedstock for biofuel

Archbold, Brad. January 2007 (has links) (PDF)
Thesis (M.E.S.)--The Evergreen State College, 2007. / Title from title screen (viewed 1/24/2008). Includes bibliographical references.

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