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Energetics of lactation in the domestic dog Canis familiarisScantlebury, David Michael January 1998 (has links)
The energetics of lactation in domestic dogs was investigated. Two breeds were chosen of different masses, Labrador Retrievers (30kg) and Miniature Schnauzers (6kg). Labradors had larger litter sizes and invested more energy relative to adult weight during lactation. This was shown in a number of ways. During peak lactation they had relatively higher metabolised energy intakes, higher energy expenditures, higher ratios of litter metabolic mass to maternal metabolic mass and produced relatively more milk. In addition Labradors utilised body reserves, an investment the Schnauzers didn't make. Schnauzers, however, invested relatively more energy per pup, which was reflected by their relatively larger offspring energy expenditures. Offspring of both breeds increased significantly in mass over the experimental period of peak lactation, although the Labrador pups were significantly leaner and contained less fat in proportion to body mass than the Schnauzer pups. The gradient of the scaling relationship between litter size and body mass across different breeds of dog was significantly steeper and tighter than the interspecific scaling relationship calculated between different species of Canid of similar mass range. This is consistent with the more recent theories on the evolution of life histories, that interspecific allometric variation is an epiphenomenon of intraspecific variation. This suggests that physical constraints associated with size in dogs may limit offspring investment and milk production. The differences in energy investment during lactation between the two breeds might be explained by variations in their ability to sustain high energy expenditures. Central limitations to maximum metabolisable energy intake and energy expenditure might be important in determining reproductive output in the Labradors. Hence milk energy output might be limited by the ability of the alimentary system to acquire nutrients. In contrast, peripheral limitations might limit Schnauzers' ability to allocate energy to offspring. Hence milk production might be limited by mammary output capacity. A three dimensional model relating energy expenditure and fitness to body mass was produced. This advanced a number of predictions. For instance, it is predicted that the observed FMR/RMR ratio would be greater in larger animals. Second, that maximal sustained metabolic rate would be more likely to be limited peripherally in small mammals. Thus maximum energy intake required for single activities, such as lactation or thermoregulation, could represent peripheral limitations in small mammals but central limitations in large mammals.
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A review of the feasibility of alternative energy system using an energy return on investment analysisJeanson, Joshua Hans 03 May 2019 (has links) (PDF)
To support further technology development and to promote the growth of a renewable biofuels industry that will satisfy the stated expectations of anticipated energy needs, it is essential that energy production systems provide a net energy gain over the course of their lifetime. As a means to provide accurate analysis to the value of alternative energy systems this paper provides a mechanism to evaluate energy systems in terms of energy generation ratios that is in terms of existing analysis techniques utilized in existing energy generation areas, such as the oil industry. This paper also proposes techniques that help perform this net energy analysis in terms of the specific economy considering the infrastructure investment.
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EROI of crystalline silicon photovoltaics : Variations under different assumptions regarding manufacturing energy inputs and energy outputLundin, Johan January 2013 (has links)
Installed photovoltaic nameplate power have been growing rapidly around the worldin the last few years. But how much energy is returned to society (i.e. net energy) by this technology, and which factors contribute the most to the amount of energy returned? The objective of this thesis was to examine the importance of certain inputs and outputs along the solar panel production chain and their effect on the energy return on (energy) investment (EROI) for crystalline wafer-based photovoltaics. A process-chain model was built using publicly available life-cycle inventory (LCI) datasets. This model has been kept simple in order to ensure transparency. Univariate sensitivity analysis for processes and multivariate case studies was then applied to the model. The results show that photovoltaic EROI values are very sensitive to assumptions regarding location and efficiency. The ability of solar panels to deliver net energy in northern regions of the earth is questionable. Solar cell wafer thickness have a large impact on EROI, with thinner wafers requiring less silicon material. Finding an alternative route for production of solar-grade silicon is also found to be of great importance, as is introduction of kerf loss recycling. Equal system sizes have been found to yield an primary EROI between approximately 5.5-19 depending on location and assumptions. This indicates that a generalized absolute EROI for photovoltaics may be of little use for decision-makers. Using the net energy cliff concept in relation to primary EROI found in this thesis shows that primary EROI rarely decreases to less than the threshold of 8:1 in univariate cases. Crystalline photovoltaics under similar system boundaries as those in the thesis model does not necessarily constrain economic growth on an energetic basis.
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Optimal Investment Strategy for Energy Performance Improvements in Existing BuildingsRamkrishnan, Karthik 15 November 2007 (has links)
Current global efforts for energy conservation and optimization are focused on improvements in energy supply and production systems, and on encouraging the adoption of energy-efficient devices and equipment. However, systematic assessments of economic and technical implications when adopting energy-efficient alternative systems in buildings have not yet been explored thoroughly. The uncertainty about the consequences of investing in alternative energy-efficient systems has led to a prolonged utilization of obsolete building systems (underperforming HVAC systems, inefficient lighting systems, badly maintained and equipment, and so forth). This has led to overall poor energy efficiency, creating considerable burden on the building operation budget.
This research discusses the procedure for formulating an investment strategy to improve existing building energy performance. The approach is suitable for large building portfolios where a plethora of potential refurbishment interventions can be considered. This makes our approach especially suited for use on university campuses and most of this report will focus on that particular application utilization protocols especially for use on campuses. This investment model only looks at the energy related savings versus investments; it is well understood that the ultimate selection of the optimal set of improvement options of a portfolio will be determined by additional considerations, such as overall value, occupant satisfaction, productivity improvements, aesthetics, etc. Nevertheless, many campus managers are confronted with the question how much energy they can save with a given investment amount. This is exactly what our approach helps to answer.
The investment optimization strategy is implemented in software "InvEnergy," which systematically calculates the costs and benefits of all possible building-technology pairings, taking uncertainties in the saving/investment calculations and estimates into account. This tool empowers decision makers in facility management to make complex investment decisions during continuous building commissioning.
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Barriers to and determinants of funding sustainable development projects in developing countries : a case study of the eThekwini MunicipalitySangham, Anilrai I. January 2017 (has links)
Submitted in fulfillment of the requirements for the Degree of Doctor of Philosophy, Durban University of Technology, Durban, South Africa, 2017. / The purpose of this study was to evaluate the barriers to and the determinants of funding sustainable development through the implementation of the Clean Development Mechanism at the Bisasar Road and Mariannhill landfill sites.
The Clean Development Mechanism is an economic construct, arising out of the Kyoto Protocol (UNFCCC 2004:10), and formulated to promote social and economic welfare by transferring technology in such a manner, that it promotes sustainable development and ecological renewal. The stated goal of CDM (UNFCCC: 10) is to reduce harmful emissions and thereafter, to produce sustainable development and ecological renewal.
This research utilised the case study methodology as advocated by Eisenhardt (1989:538). The study employed multiple data collection methodologies which included face-face interviews, within case analysis, triangulation, field notes and photographs. An important component of the data collection methodology was to access financial records of revenue flows for the CDM implementation process from January 2009 to December 2015.
The research found that there is no conclusive evidence to suggest that the Clean Development Mechanism, as implemented at Bisasar Road and Mariannhill, reduced carbon emissions. Further, the study found that the production of clean energy produced financial losses rather than revenues for funding sustainable development.
The relevance and value of this research lies in the presentation and formatting of the Systematic Sequential Analysis Model. The purpose of the Systematic Sequential Analysis Model is to introduce a series of financial, macro-economic, micro-economic, and technical sustainability filters for the implementation of the Clean Development Mechanism in developing countries. / D
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Why are fish in the Baltic Sea so small? : A study of somatic and gonad growth in relation to salinity in turbot (Scophthalmus maximus)Wallin, Isa January 2014 (has links)
It has been shown that fish of both marine and limnetic origin display increased growth at intermediate salinities. Furthermore, it has been shown that fish in the brackish water Baltic Sea are smaller compared to their conspecifics in the Atlantic, where salinities are higher. Also, it has been suggested that fish produce more eggs at the edges of their distribution range as a response to inferior environmental conditions. In this study, I investigated if there is a trade-off in energy investment between somatic and gonad growth in relation to salinity. To do this, I performed a growth experiment and a literature review. In the growth experiment, juvenile turbot were reared in salinities of 6, 10.5, 15 and 30 ‰. I found that turbot juveniles from Gotland grew equally well in all salinities investigated. In the literature review, data from the Baltic Sea was tested against data from the North and Black Seas. Data of turbot total energy investment (somatic and gonad growth) was analyzed. I found that energy content at age differed significantly between the populations investigated with lower energy content for the Baltic Sea populations. Also, growth rate in relation to energy content (size) was analyzed for the different populations, but no difference for growth rate in relation to energy content occurred. The result of the analysis of growth rate indicates that the change in allocated energy is the same, regardless of population, and thus that fish from the Baltic Sea display growth rates similar to those of other populations. It was also established that energy investment in gonads increased along with decreasing salinities. The smaller size of turbot in the Baltic Sea is therefore probably the result of a difference in size at maturity, possibly because less energy is allocated to somatic growth and more energy to start producing eggs. It is probably also the consequence of that the Baltic Sea turbot, post sexual maturity, continue to invest more energy in egg production.
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An exploration of renewable energy policies with an econometric approachKilinc Ata, Nurcan January 2015 (has links)
This thesis focuses on the renewable energy policies for the case study countries (European Union, United States, United Kingdom, Turkey, and Nigeria) with using quantitative and qualitative analysis. The thesis adopts a three -pronged approach to address three main issues: The first paper investigates a 1990-2008 panel dataset to conduct an econometric analysis of policy instruments, such as; feed-in tariffs, quotas, tenders, and tax incentives, in promoting renewable energy deployment in 27 EU countries and 50 US states. The results suggest that renewable energy policy instruments play a significant role in encouraging renewable energy sources. Using data from 1990 to 2012 with the vector auto regression (VAR) approach for three case study countries, namely United Kingdom, Turkey, and Nigeria, the second paper focuses on how renewable energy consumption as part of total electricity consumption is affected by economic growth and electricity prices. The findings from the VAR model illustrate that the relationship between case study countries’ economic growth and renewable energy consumption is positive and economic growth in case study countries respond positively and significantly. The third paper focuses on the relationship between renewable energy policies and investment in renewables in the countries of United Kingdom and Turkey. The third paper builds upon current knowledge of renewable energy investment and develops a new conceptual framework to guide analyses of policies to support renewables. Past and current trends in the field of renewable energy investment are investigated by reviewing the literature on renewable energy investment linkage with policies, which identifies patterns and similarities in RE investment. This also includes the interview analysis with investors focusing on policies for renewable energy investment. The results from the interview and conceptual analysis show that renewable policies play a crucial role in determining investment in renewable energy sources. The findings from this thesis demonstrate that renewable energy policies increase with a growth of the renewable energy investment in the sector. Finally, the outcomes of this thesis also contribute to the energy economics literature, especially for academic and subsequent research purposes.
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Impactos dos investimentos no setor energético brasileiro sobre as emissões de CO2: uma abordagem de equilíbrio geral computávelViana, Jorge Henrique Norões 01 March 2011 (has links)
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Previous issue date: 2011-03-01 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / This study analyses the effects of an increase in investments to energy production, over the emissions of CO2 and the main macroeconomic variables. The data required for their preparation were obtained from the Ministry of Mines and Energy, the IBGE and the Intergovernmental Panel on Climate Change. To meet these goals, the energy inputs were divided into two groups: energy "clean" and "dirty"; based on their coefficients of CO2 emissions in 2006. Then, were simulated scenarios with: increases in investment equivalent to 1% of GDP in 2006, for each energy group, as well as scenarios involving an environmental tax of R$ 100.00 per ton of CO2; for a time horizon of ten years, using a sequential Computable General Equilibrium Model. The results of these simulations showed that there was a direct relationship between increased investments in energy and: the process of capital accumulation, the real GDP growth, the evolution of welfare, the evolution of CO2 emissions and changes in the intensity of CO2 pollution. Meanwhile, the results for simulations involving the environmental tax shown that it implied, in general, in: slowdown in capital accumulation, GDP growth below the steady state, a strong reduction of welfare and increasing reductions of emissions and intensity of pollution. Especially, the combination of an increase in investments for clean energy production, with the adoption of the environmental tax, was able to generate, simultaneously: accelerated accumulation of capital (2,70%) and real GDP growth (1,08%), increase of the welfare (R$ 33 billion) and reduction of the emissions (-1,21%) and intensity of pollution (-2,26%). / Este estudo trata dos efeitos de um aumento dos investimentos destinados a produção de energia, sobre as emissões de CO2 e as principais variáveis macroeconômicas. Os dados necessários à sua elaboração foram obtidos junto ao Ministério de Minas e Energia, ao IBGE e o Intergovernmental Panel on Climate Change. Para cumprir com esses objetivos, os insumos energéticos foram divididos em dois grupos: energéticos limpos e sujos ; com base nos seus coeficientes de emissões de CO2 em 2006. Em seguida, foram simulados cenários com: aumentos nos investimentos equivalentes a 1% do PIB em 2006, para cada grupo de energético; bem como cenários envolvendo um imposto ambiental de R$ 100,00 por tonelada de CO2; para um horizonte de tempo de dez anos, utilizando um Modelo de Equilíbrio Geral Computável sequencial. Os resultados dessas simulações mostraram que existiu uma relação direta entre o aumento dos investimentos em energia e: o processo de acumulação de capital, o crescimento do PIB real, a evolução do bem-estar, a evolução das emissões de CO2 e a evolução da intensidade de poluição por CO2. Enquanto isso, os resultados para as simulações envolvendo o imposto ambiental mostraram que o mesmo implicou, de maneira geral, em: desaceleração do processo de acumulação de capital, crescimento do PIB abaixo do estado estacionário, forte redução do bem-estar e redução crescente das emissões e da intensidade da poluição. Especialmente, a combinação de um aumento dos investimentos destinados a produção de energia limpa, com a adoção do imposto ambiental, foi capaz de gerar, simultaneamente: aceleração da acumulação de capital (2,70%) e crescimento do PIB real (1,08%); aumento do bem-estar (R$ 33 bilhões); e redução das emissões (-1,21%) e da intensidade da poluição (-2,26%).
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A transição para uma matriz energética limpa : os avanços na tecnologia solar / The transition towards a clean energy matrix : the advances in solar technologySuzigan, Kelly Rosana, 1983- 27 August 2018 (has links)
Orientador: Ademar Ribeiro Romeiro / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Economia / Made available in DSpace on 2018-08-27T14:56:12Z (GMT). No. of bitstreams: 1
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Previous issue date: 2015 / Resumo: As reservas mundiais de petróleo, carvão e gás natural podem acomodar maior crescimento no uso destas fontes de energia sobre as próximas décadas, mas agrava os enormes desafios colocados pelas alterações climáticas. A produção e o consumo energético de energia têm grande impacto na sociedade e na natureza, e o uso dos combustíveis fósseis é claramente insustentável com consequências potencialmente catastróficas. Desta forma, a necessidade de transição para uma matriz energética mais limpa é evidente, podendo ser observada através do redirecionamento da política energética de algumas das nações líderes do mundo. Dentre as tecnologias energéticas limpas, a tecnologia solar tem se destacado no cenário mundial, e por hipótese a energia solar deverá ser a principal fonte para geração de eletricidade no futuro. Esta dissertação pretende contribuir com a investigação acerca do desenvolvimento e perspectivas da energia solar no mundo, trazendo alguma luz à controvérsia sobre a possibilidade de superação do paradigma energético baseado na combustão de fósseis a tempo de se evitar um possível desastre ambiental. O presente trabalho divide-se em três partes. A primeira parte trata da necessidade da transição da matriz energética baseada em uso de combustíveis fósseis para uma baseada em energia limpa, essencial em decorrência das já comprovadas limitações ambientais, que se agravará futuramente diante da expectativa de largo aumento na demanda de energia para acompanhar o crescimento econômico futuro. A segunda parte faz uma breve discussão acerca de algumas questões relativas à construção de um novo paradigma energético e da inovação em tecnologias de energia de baixo carbono, além de salientar especificidades da tecnologia solar. Por fim, na terceira parte traça-se um panorama do cenário atual mundial com relação ao setor de energia solar a partir dos principais países que investem na tecnologia: Estados Unidos, Alemanha, Japão e China. Neste capítulo será analisado o progresso do setor solar em cada país, apontando as políticas de incentivo, desenvolvimento da indústria solar, evolução do mercado e perspectivas futuras da energia solar / Abstract: The world reserves of oil, coal and natural gas can accommodate further growth in energy use over the next few decades, but aggravates the great challenges posed by climate change. The production and consumption of energy have been creating great impact in our society and nature, and the consumption of fossil fuels is clearly unsustainable with potentially catastrophic consequences. Thus, the importance of renewable forms of energy is growing robustly, which can be observed by the energy policies of some of the leading nations in the world. Among the renewable forms of energy, solar power generation is becoming mainstream and by hypothesis is likely to become the world¿s most important source for electricity generation in the future. This thesis aims to contribute on the research concerning the development and prospects of solar energy in the world, bringing some light to the controversy about the possibility of overcoming the energy paradigm based on the combustion of fossil in time to prevent a possible environmental disaster. This paper is divided into three parts. The first one highlight the need for a transition from a fossil fuel-based society to one based on renewable energy, enabling a more sustainable growth. The second part is a brief discussion regarding the construction of a new energy paradigm and the innovations in the in low-carbon energy technologies, highlighting specific characteristics of the solar technology. Finally, the third part makes an overview of the current scenario, especially the one regarding the solar industry in the most advanced countries in the development of solar energy (United States, Germany, Japan and China). In this chapter an analysis is made about the progress of the solar energy in each country, pointing out government subsidies, industry and market development and future prospects of solar energy / Mestrado / Desenvolvimento Economico, Espaço e Meio Ambiente / Mestra em Desenvolvimento Econômico
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CMOS inductively coupled power receiver for wireless microsensorsLazaro, Orlando 22 May 2014 (has links)
This research investigates how to draw energy from a distant emanating and alternating (i.e., AC) magnetic source and deliver it to a battery (i.e., DC). The objective is to develop, design, simulate, build, test, and evaluate a CMOS charger integrated circuit (IC) that wirelessly charges the battery of a microsystem. A fundamental challenge here is that a tiny receiver coil only produces mV's of AC voltage, which is difficult to convert into DC form. Although LC-boosted diode-bridge rectifiers in the literature today extract energy from similar AC sources, they can do so only when AC voltages are higher than what miniaturized coils can produce, unless tuned off-chip capacitors are available, which counters the aim of integration. Therefore, rather than rectify the AC voltage, this research proposes to rectify the current that the AC voltage induces in the coil. This way, the system can still draw power from voltages that fall below the inherent threshold limit of diode-bridge rectifiers. Still, output power is low because, with these low currents, small coils can only extract a diminutive fraction of the magnetic energy available, which is why investing battery energy is also part of this research. Ultimately, the significance of increasing the power that miniaturized platforms can output is higher integration and functionality of micro-devices, like wireless microsensors and biomedical implants.
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