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1
Fatima, Sadia. "High energy density nutritional supplements : impact on appetite, appetite regulation and energy intake in underweight and malnourished individuals." Thesis, University of Glasgow, 2014. http://theses.gla.ac.uk/6297/.
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This thesis describes the impact of high energy density nutritional supplement drinks (HENSDs) on appetite regulation, energy intake and cardiovascular risk factors in lean healthy females. It also explores the impact of Solid Ready-To-Use Foods (RTUF) and a milk based Liquid Ready-To-Use proprietary Supplement (LRUS) on weight gain and appetite in mild to moderate underweight children from Pakistan. The thesis consists of a literature review (Chapter 1), general methods (Chapter 2), three experimental chapters (Chapter 3- Chapter 5), each describing an independent research study, and a general discussion and conclusion chapter (Chapter 6). Accumulating evidence suggests that oral HENSDs increases energy intake and are beneficial for the treatment of malnutrition. Their effectiveness however, may be diminished by acute suppression of appetite. Therefore, the first experimental study aimed to investigate the extent to which the consumption of the HENSD in the fasted state reduces energy intake during a consecutive breakfast and lunch and whether this reduction relates to changes in appetite and metabolic appetite regulators. Twenty three young females with BMI of 18.2 ± 0.8 kg/m2 consumed either a HENSD or a low energy drink (PLACEBO) after fasting, in a single blind randomized cross-over study. Appetite was tracked, and blood taken, prior to the intake of the supplement and 240 minutes afterwards. Energy intake was recorded during an ad libitum buffet breakfast served 60 minutes and an ad libitum buffet lunch served 240 minutes post supplementation. Energy intake during the breakfast was significantly higher in the PLACEBO than in the HENSD trial. No significant difference was found in energy intake during the lunch between the two trials. When energy provided by supplements was added to energy intake during breakfast and lunch, the energy intake in the HENSD trial was significantly higher. The net effect was that total energy intake was increased by 1.07 ± 0.34 MJ in the HENSD trial. During the pre-breakfast, feelings of hunger and a desire to eat were significantly lower; satiety and fullness were significantly higher in the HENSD trial. After breakfast, none of the appetite measures differed between the trials regardless of plasma PYY, CCK, and insulin concentrations being significantly higher in the HENSD trial. The second experimental study investigated the time scale of compensation after HENSD supplementation. Over a five day period, energy intake was measured after the supplementation during the evening meal, and during the ad libitum breakfast, lunch and dinner consumed on the consecutive day. Since, consumption of HENSD due to the promotion of energy was expected to promote positive energy balance, this study also aimed to investigate the impact of HENSD supplementation on cardio-metabolic risk factors. Twenty-three young healthy females with a BMI of 18.7 ± 1.2 kg/m2 participated in a single blind randomised, controlled, crossover study. Participants consumed either HENSD or a PLACEBO for five days in the evening. Participants were asked to record their dietary intake during the days of supplementation. On the sixth day plasma lipids, insulin and glucose concentrations were measured in the fasted state and at 30, 60, 90 and 120 minutes after the ad libitum buffet breakfast and lunch. The findings showed that the average daily energy intake was significantly higher in HENSD trial and that consumption of HENSDs in the evening induced immediate and short-lasting reduction in energy intake. Fasting plasma concentrations of insulin and HOMA (IR) were significantly higher in the HENSD as compared to the PLACEBO trial. No significant differences were detected in fasting plasma concentrations of TAG, total-, HDL- and LDL-cholesterol between the HENSD and the PLACEBO trials. The third experimental study explored the efficacy of RTUFs and LRUS in promoting weight gain and their effect on appetite regulation in mild to moderate malnourished children. An open labelled randomized controlled trial was conducted in primary schools of Pakistan. Sixty eight mild to moderate underweight children aged 8.2 ± 1.2 years were randomly allocated to receive either RTUF or LRUS providing 500 kcal/ day in addition to regular diet in their school for four weeks. The children’s height, weight, and skinfolds were measured before supplementation and at the end of the supplementation. The children marked visual analogue scale questionnaires before the provision of the first and the last supplement. The findings from this study indicated that after four weeks of supplementation the average weight gain, change from the baseline in weight-for-age Z score (WAZ), height-for-age Z score (HAZ) in the RTUF and LRUS were not significantly different between the two groups. The difference in the appetite measures before the provision of the first and the last supplement between the two groups were also not significantly different. The total extra energy supplied for 4 weeks would have been expected to lead to an excess gain of 2kg. Thus, at least 2/3 of the energy ingested appeared to have been compensated by less intake at other times. Based on the data obtained the following conclusions have been drawn: • Following oral intake of HENSDs, the appetite suppressive action of the metabolic and hormonal appetite modulators is short lived. • HENSDs consumption for five consecutive days in the evening induced compensation, which happens immediately, disappears quickly and is short-lived which allows only partial compensation for the energy provided by HENSD. • Short-term supplementation with HENSD is safe in relation to the impact on cardiometabolic risk factors such as plasma concentration of fasting and postprandial lipids but can be expected to reduce insulin sensitivity. • RTUF and LRUS given to the community has similar impact on improving the nutritional status in mild of moderate underweight children but the overall rate of weight gain was lower than expected.
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Regen, Eli. "Direct Probes for R-Parity Violation at the LHC." Thesis, Illinois Institute of Technology, 2018. http://pqdtopen.proquest.com/#viewpdf?dispub=10680821.
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As the LHC enters its second run at 13 TeV, new parameter space will become available that will allow for a more extensive search for supersymmetric partners. This thesis explores limits on a baryon number violating R-parity-violating (RPV) extension of the s-channel production of top squarks, examining the experimental signature for the R-parity conserving decay of the top squark into the lightest neutralino and a hadronically decaying top quark. Using Monte Carlo simulations I calculate upper bounds for the RPV coupling parameters λ'' for a range of top squark and neutralino masses that would allow for its existence.
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Abbey, Chad Michel. "Energy storage system optimization and control with wind energy." Thesis, McGill University, 2009. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=66694.
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This thesis proposes a methodology for planning, scheduling and on-line control of an energy storage system for the integration of wind energy. Using the case study of a remote wind-diesel system, the different time frames of the design and implementation process are detailed. First, a long-term planning approach for rating of the power and energy capacities of the ESS is presented, based on stochastic optimization. The formulation is then adapted into a hourly scheduling approach and results are compared with the expected cost of energy and energy requirements resulting from the planning study. The optimization results are used as training data for an artificial neural network, in an effort to generate an on-line control that captures inherent rules, using artificial intelligence. The ESS is realized as a two-level ESS and a general control structure for on-line operation of multi-level ESS is proposed and adapted for the wind-diesel system, as the first level in a hierarchical control. The system is evaluated in simulation and selected results are validated using a hardware-in-the-loop representation of the system, demonstrating that the proposed controller is realizable.Cette thèse propose une méthodologie pour la planification, l'utilisation et la commande d'un système de stockage d'énergie permettant l'intégration de l'énergie éolienne. Utilisant comme étude de cas un réseau autonome alimenté par un système éolien-diesel, les différentes étapes de la conception et la mise en oeuvre sont détaillées. Premièrement, une étude de planification à long terme pour le dimensionnement de la puissance nominale et de la capacité énergétique du stockage est présentée, basée sur les méthodes d'optimisation stochastique. La formulation est ensuite adaptée à une commande sur une base horaire et les résultats sont comparés, au niveau de l'énergie et de la quantité d'énergie utilisée, aux résultats obtenus dans l'étude de planification. Les résultats obtenus par optimisation du système sont utilisés dans l'entrainement d'un réseau de neurones artificiels, afin de produire une commande qui capte les règles inhérentes au système, utilisant l'intelligence artificielle. Le stockage d'énergie est réalisé par un système de stockage à deux niveaux et une structure de commande appropriée à plusieurs niveaux est proposée et adaptée pour un système éolien-diesel, comme premier niveau d'une commande hiérarchique. La performance du système est évaluée par simulation et certains résultats ont été validés avec un banc d'essai. Celui-ci consiste à des convertisseurs électroniques intégrés avec une représentation par simulation temps réel du système. Les résultats obtenus concordent avec les résultats de simulation et confirment que la commande proposée est réalisable.
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Zhang, R. "R-matrix calculations of polarisation effects in low-energy positron-molecule collisions." Thesis, University College London (University of London), 2010. http://discovery.ucl.ac.uk/552286/.
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The study of the interaction of positrons with atoms and molecules has become increasingly popular, because more and more experimental activities have become feasible. Although exchange effects are absent, the polarisation effects, caused by the attractive nature between the positron and the target electrons, make the positron-molecule collisions more diffcult to handle than the corresponding electron collisions. This thesis gives the calculations of positron collisions with polar molecule H2O and non-polar molecules, H2 and C2H2 at energies below the positronium formation threshold. All calculations were carried out using the modied version of the UK molecular R-matrix code. Due to the large permanent dipolar nature of water molecule, the three models tested give very similar results. However, for positron collision with non-polar molecules, the polarisation effects can be very important in the calculation. The molecular R-matrix with pseudostates (MRMPS) method has been employed to analyse the positron collision with non-polar molecules, and found to lead to an excellent representation of target polarisation. C2H2 is the simplest molecule that has very enhanced annihilation parameter Zeff, which can be determined by the total scattering wavefunction. So a new sub-code was developed for calculating Zeff based on the UK R-matrix polyatomic code and employed to treat positron collisions with H atom, H2 and C2H2 molecules. It has been found that Zeff values are also sensitive to the degree of polarisation included in calculations and are greatly improved by use of the MRMPS method.
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McIntyre, M. W. "Single and double ionisation processes within an intermediate energy R-Matrix framework." Thesis, Queen's University Belfast, 2014. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.679261.
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This thesis makes use of the intermediate energy R-matrix approach (IERM) in computationally modelling various single and double ionisation processes. The basis used in the IERM approach is an ideal candidate for representing a double electron continua in a time-dependent or time-independent, general N-electron R-matrix code and one of the main objectives of the thesis is to explore the efficacy of the basis used in the IERM approach in representing a double-electron continua. To do this, the IERM method is applied to the study of photoionisation and photo-double-ionisation of various He-like and Be-like atoms and ions in the ground and excited initial states, and preliminary calculations of electron impact excitation involving high lying energy levels of H is investigated with the two-dimensional R-matrix propagator package. The convergence of the basis for these processes is examined. Throughout the thesis the results obtained with the IERM method are compared to experimental results and those from other state of the art theoretical approaches, and agreement is excellent in all cases. In the case of He-like and Be-like atoms and ions, trends in moving along the isoelectronic sequences and between the ground and various excited states are analysed and compare well with existing models where available. The data presented is also of use in astrophysical applications, to experimentalist and to other theorist who wish to study these or similar systems. The IERM basis is shown to be capable of representing a double electron continua and directions in which further work in this field could take are highlighted.
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Sfakianakis, Dimitrios. "A dynamic energy modelling approach to low energy ship design." Thesis, University of Strathclyde, 2015. http://oleg.lib.strath.ac.uk:80/R/?func=dbin-jump-full&object_id=25918.
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Despite remarkable advances in naval architecture in the past few years, limited effort has been expended to improve the energy efficiency of ships due to the relatively low price of fuel oil and lack of stringent environmental regulations. However, the ever-growing intercontinental trade has resulted in an increase of greenhouse gas emissions from ships that triggered the introduction of mandatory environmental measures and shifted the focus of the shipping industry towards more energy efficient designs and operations. This thesis focus is on improving the energy efficiency of ships during design and operation by adopting a direct approach to estimating the requisite thermal energy on board ships over their life cycle. This is achieved by dynamically modelling the thermal energy flows on board, drawing from the considerable developments in Building Energy Simulation (BES), which precedes developments in the maritime industry by five decades. To this end, and in broad terms, the thesis focus is on and embodies the technology transfer from the Buildings Industry to the Marine Industry ("marinisation of BES") whilst accounting for the differences and complexities implicit in some of the ship types as well as the marine environment and operations. This, in turn, necessitates focus on applicability, functionality and limitations of BES in ships with the view to enable developments to fill pertinent gaps and to demonstrate such developments with purposely selected case studies. During the investigation of the applicability of BES in ships, the main differences between ships and buildings were identified, and their effect on energy simulation was pointed out. The results of this comparison served as the basis for the marinisation of the selected building energy simulation software 'ESP-r', which was enhanced to also cater for energy flows present in the marine environment, leading to the development of 'ESP-r marine'. Despite the ability of the tool to model the majority of thermal energy flows on board ships, several modelling and computational problems were presented during the development of large accommodation models that triggered necessary simplification considerations. In an attempt to allow energy modelling of smaller groups of spaces and drop the requirements for explicit and topologically correct model representation, the geometrical decoupling of major space types was examined. A verification process based on energy simulation was used to construct guidelines, indicating acceptable assumptions for the boundary conditions of individually modelled or groups of accommodation spaces. This methodology was then used to facilitate further simplification of thermal modelling, which was achieved through the concept of space grouping that encompassed the process of the consecutive merging of adjacent spaces, until groups of spaces were represented by a single thermal zone. Throughout this process the loss of accuracy in the results was quantified, and results were used to develop design guidelines for the group representation of major types of on board spaces. All findings were used to form a methodology for the design of the most common ship accommodation spaces and relevant HVAC systems which outer performs current practices, since it provides detailed information about state variables in accommodation spaces and energy systems components, and allows for the calculation of the power consumption of the energy systems serving the accommodation over the ship's life-cycle at a low computational cost. Implementation of the methodology was exhibited with two case studies, one for a cargo and one for a passenger ship. The work undertaken and the derived results clearly demonstrate the applicability of BES to ships and the extent to which it can be simplified during the design process, thus introducing the concept of Dynamic Energy Modelling as a platform in shipping to support life-cycle energy management. This constitutes a significant development in shipping.
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Rae, Callum. "Variable energy pricing in stand alone community hybrid energy systems." Thesis, University of Strathclyde, 2016. http://oleg.lib.strath.ac.uk:80/R/?func=dbin-jump-full&object_id=27096.
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Satisfying the demand for a more efficient and sustainable energy supply model has presented a new challenge for the energy industry. It has also created an opportunity for alternative and renewable sources of energy generation, which has led to a significant increase in the deployment of renewable technologies in many countries. Recent years have also seen these technologies deployed at a community scale, with remote and isolated communities in particular being regarded as ideal locations. Such systems are capable of providing increasingly viable, standalone alternatives to the centralised energy supply model. This thesis investigates the extent to which the viability of these stand-alone hybrid energy systems could be further improved by implementing domestic demand response, promoted via variable domestic energy pricing. A high resolution,disaggregated model of domestic energy demand at the community level is then developed, supported by the findings of a targeted consumer attitudes survey. This model is combined with a series of demand response algorithms which replicate the response of domestic consumers to energy price variation. Three variable pricing approaches are then applied to the model under a range of conditions, and the impacts examined from both a community-wide and household level perspective. The thesis demonstrates the relevance and potential of stand-alone hybrid applications and the remote/isolated communities in which they are typically deployed. The results find variable domestic energy pricing based on renewable energy supply to be capable of achieving modest yet significant levels of demand response under a broad range of conditions (83% of the scenarios modelled).Further sensitivity analysis shows the pricing strategies to be resilient to changes in supply conditions, thereby illustrating the broad ranging potential of such an approach. However, susceptibility to free-rider behaviour and insensitivity to household elasticity levels suggest the need for additional/supplementary forms of financial incentivisation.
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Lima, Felipe Braz de. "Reprodução de peixes de riachos: uma abordagem comparativa entre as estratégias r e K." Universidade do Estado do Rio de Janeiro, 2012. http://www.bdtd.uerj.br/tde_busca/arquivo.php?codArquivo=4316.
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No presente trabalho, objetivou-se caracterizar a estratégia reprodutiva, enfatizando o investimento energético, de duas espécies de peixe do rio Ubatiba, Maricá, Rio de Janeiro: Parotocinclus maculicauda (K-estrategista) e Astyanax hastatus (r-estrategista). Foram realizadas coletas bimestrais de Junho de 2010 a Abril de 2011 totalizando 236 exemplares amostrados de A. hastatus e 234 de P. maculicauda. Para cada exemplar foram registrados os dados de comprimento padrão (Cp, cm), peso total (Pt, g), peso gonadal (Pg, g), sexo e estádio de maturação. Através da estrutura de tamanho, observamos que as fêmeas atingem maior comprimento, em relação aos machos, para as duas espécies. A relação peso/ comprimento evidenciou para ambas as espécies, crescimento alométrico negativo (inferior a 3), demonstrando crescimento mais longelíneo. Para a proporção sexual, o teste χ2 foi aplicado e indicou que, para as duas espécies, há significativamente mais fêmeas. A distribuição sexual no ano mostrou que as fêmeas se mantêm em maioria durante todo o ano para P. maculicauda. Para A. hastatus este padrão também se mantém, porém com exceção do bimestre Novembro/Dezembro, quando o número de machos torna-se um pouco maior. O tamanho de primeira maturação mostrou-se o mesmo para ambas as espécies (2,5 a 3,0 cm). A variação temporal da freqüência de indivíduos reprodutivos e não reprodutivos juntamente com a distribuição temporal dos valores individuais de IGS mostrou que P. maculicauda se reproduz com maior intensidade nas estações chuvosas (Setembro a Abril), reduzindo sua atividade reprodutiva de maneira significativa nas estações secas (Maio a Agosto). Já A. hastatus demonstrou regular atividade reprodutiva durante todo o ano com pequeno pico no bimestre Novembro/ Dezembro. Desova do tipo total foi registrada para Astyanax, enquanto que para Parotocinclus registrou-se desova parcelada em três lotes. Em ambas as espécies foi observada relação inversa entre volume e a quantidade de ovócitos produzidos, com A. hastatus produzindo muitos ovócitos (fecundidade: 463 + 213 ovócitos/grama de peixe) de reduzido volume (diâmetro = 800 μm e volume = 0,26 mm3) e P. maculicauda produzindo número bem inferior (fecundidade: 47 + 13 ovócitos/grama de peixe), porém com volume superior (diâmetro = 1.600 μm e volume = 2,14 mm3). Com isso o valor energético relativo também se mostrou superior, com A. hastaus produzindo ovócitos vitelogênicos com 0,4+ 0,08 cal/unidade e P. maculicauda produzindo os mesmos ovócitos com 1,8+ 1,1 cal/unidade. Para a produção energética total investida na produção de gametas, foi considerado o tipo de desova de cada espécie, com Astyanax investindo 50,5 + 24 calorias/grama/grama de peixe e Parotocinclus investindo 88,4 + 72,46 cal/grama/grama de peixe, porém sem diferenças significativas (Mann-Whitney; U =235,0, p=0,08), indicando, portanto que independente da estratégia adotada (r ou K), o gasto energético na produção de ovócitos é a mesma.The present study aimed to characterize reproductive strategy, focusing on energy investment, of two fish species present in the river Ubatiba (2250, 2255S e 4243, 4250W), Maricá, Rio de Janeiro: Parotocinclus maculicauda (K-strategist) and Astyanax hastatus (r-strategist). Were collected bimonthly from June 2010 to April 2011, in two sites, totaling 236 specimens for A. hastatus and 234 specimens for P. maculicauda. For each sample were recorded standard length (Ls, cm), total weight (Wt, g), gonad weight (Wg, g), sexes and maturity stage. Through the size structure, we observed that females reach a greater length, compared to males of both species. The relation weight / length for both species showed a negative allometric growth (below 3). For sex ratio, the χ2 test was applied and indicated that, for both species, there are significantly more females. The distribution sexes in the year showed that females remain in the majority throughout the year for P. maculicauda, with the exception of November / December for the A. hastatus, when the number of males becomes greater. The size at first maturity indicated values in the same length class (2.5 to 3.0 cm). The temporal variation in the frequency of non-reproductive and reproductive individuals along with the temporal distribution of individual values of GSI showed that Parotocinclus is reproduced with greater intensity in the rainy seasons (September to April), reducing their reproductive activity significantly in the dry seasons (May to August). Astyanax showed regular reproductive activity throughout the year with a small peak in November / December. Spawning of total type was found for Astyanax, while for Parotocinclus, spawning is split into three lots. In both species was observed an inverse relationship between volume and number of oocytes produced, with Astyanax producing many oocytes (fecundity: 463 + 213 oocytes / g fish) and reduced volume (diameter = 800 μm e volume = 0.26 mm3) and Parotocinclus producing a much lower number (fecundity: 47 + 13 oocytes / gram of fish) but with volume so much higher in vitellogenic oocytes (diameter = 1.600 μm e volume = 2.14 mm3). Thus the relative energy value was also much higher, with Astyanax producing vitellogenic oocytes with 0.4+ 0.08 cal / unit and Parotocinclus producing the same oocytes with 1.8+ 1.1 cal / unit. For the total investment in the production of oocytes to be spawned, was considered the type of spawning of each species, Astyanax spending 50.5 + 24 calories/gram/gram of fish and Parotocinclus spending 88.4 + 72.46 cal/gram/gram of fish. The Mann-Whitney test was used and showed no significant differences in energy investment (Mann-Whitney; U =235.0, p=0.08), indicating therefore that regardless of the strategy (r or K), energy expenditure in the production of oocytes is the same.
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Bross, Rachelle. "Fluoxetine and energy expenditure in obese humans subjected to energy restriction." Thesis, McGill University, 1993. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=69699.
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I investigated the effects of continuous administration of fluoxetine, a serotonin reuptake inhibitor, on energy expenditure, body temperature, and thyroid and catecholamine metabolism during weight reduction using a very low calorie diet (VLCD, Optifast, 1757 kJ/day) followed by a balanced deficit diet (BDD, 5016 kJ/day). Fluoxetine (60 mg/day by mouth, n = 10) or placebo (n = 10) were administered during 3 weeks of inpatient VLCD followed by 8 weeks of outpatient BDD in a double-blind, randomized design. A similar amount of weight was lost in both groups during the VLCD, but by the end of the BDD total weight loss in the fluoxetine group was significantly greater (11.0 $ pm$ 1.1 kg vs. 7.0 $ pm$ 1.0 kg, mean $ pm$ SEM, p $<$ 0.015). Resting metabolic rate (RMR) increased by 4.4 $ pm$ 1.8% (p $<$ 0.01) in the fluoxetine group but did not change in the placebo group during the first week of the VLCD, but subsequently decreased significantly in both groups as dieting continued. However, RMR remained consistently higher in the fluoxetine group for the duration of the VLCD period. No further change in RMR occurred in either group during the BDD period. The thermic effect of food did not change after VLC dieting plus fluoxetine or placebo treatment. Body temperature increased within 2 days of fluoxetine treatment by a mean of 0.3$ sp circ$C, p $<$ 0.025 and remained elevated throughout the VLCD but was unchanged in the placebo group. VLCD therapy reduced serum levels of T$ sb3$, free T$ sb3$ Index and 24-hour urinary excretion of dopamine, norepinephrine, metanephrine and normetanephrine equivalently in both groups. A thermogenic effect of fluoxetine is demonstrated in humans for the first time. The anorectic effect of fluoxetine may be related to its temperature elevating effect.
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Lopes, Rafael Christ de Castro. "Estudo do raio de turnaround em teorias f(R)." Universidade de São Paulo, 2019. http://www.teses.usp.br/teses/disponiveis/43/43134/tde-21032019-154839/.
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Nós investigamos o raio de turnaround, a distância do centro da estrutura cósmica até a casca que está se descolando do fluxo de Hubble em um dado tempo, no contexto do modelo de colapso esférico, tanto em Relatividade Geral e em Gravidade Modificada, em particular no cenário f(R) chamado de modelo de Hu-Sawicki. O próximo passo foi investigar a relação entre este raio e a massa de virial de estruturas cósmicas no contexto do modelo LCDM e no modelo f(R) de gravidade modificada.We investigate the turnaround radius, the distance from the center of the cosmic structure to the shell that is detaching from the Hubble flow at a given time, in the context of the spherical collapse model, both in General Relativity and in modified gravity, in particular f(R) scenarios -- namely the Hu-Sawicki model. The next step was to investigate the relationship between that radius and the virial mass of cosmic structures in the context of LCDM model and in an f(R) model of modified gravity.
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Chang, Xiao. "Supercapacitor based energy storage system." Thesis, University of Strathclyde, 2013. http://oleg.lib.strath.ac.uk:80/R/?func=dbin-jump-full&object_id=25509.
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The supercapacitor, as a recently developed electrochemical energy storage device, offers extremely high capacitance per unit volume. Due to its unique double-layer structure and electrostatic charge mechanism, the supercapacitor has a much higher power density than the battery, and a much higher energy density than the conventional capacitor. It also benefits from a long cycle life, and wide temperature range. However, limited by a low cell voltage of 2.7V and high equivalent series resistance, the supercapacitor may be inefficient for high power grid level applications. Characteristic analysis of the supercapacitor shows that the efficiency reduces to 54.7% at peak current conditions. Based on supercapacitor modelling studies, two parameter identification methods are proposed, which are realised by a simple experiment, with an acceptable accuracy. A parallel combined supercapacitor and electrolytic capacitor energy storage system is proposed to improve high power application performance, which offers efficiency improvements in excess of 10%. A detailed description of such parallel capacitor systems are included in this thesis, where a design guide is developed to achieve an optimal design in terms of system efficiency, power capability, and volume. The capacitor based energy storage technique is suited to distributed generation applications where low-voltage ride through and grid code compliance are important considerations. A supercapacitor based static synchronous compensator is proposed, which is able to manipulate both active and reactive power exchange with the power system. Steady-state and transient responses are studied based on simulation of a test power system. A system frequency based control algorithm is used for active power control, which has a better stabilised system frequency than with conventional voltage control. The parallel hybrid capacitor technique is employed, which greatly improves the system performance in terms of efficiency, thermally, costs, and volume, compared with a system that only uses supercapacitors.
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Vincent, Timothy A. "Development of a handheld breath analyser for the monitoring of energy expenditure." Thesis, University of Warwick, 2017. http://wrap.warwick.ac.uk/93856/.
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Metabolic rate is not routinely assessed in healthcare for the general population, nor is it a measure commonly recorded for in-patients (incorrect feeding can slow post-operation recovery rate). For the general community, this lack of knowledge prevents the accurate determination of calorific need and is a factor contributing towards the onset of an overweight and an increasingly obese population. In the UK alone, obesity costs the National Health Service a staggering £5 billion annually. In this thesis a novel low-cost hand-held breath analyser is presented in order to measure human energy expenditure (EE). A unique optical CO2 sensor was developed, capable of sampling exhaled breath with a fast response time ~1 s and resilience to a humidity range of ~30 % to near saturated. The device was tested in a laboratory gas testing rig and a detection limit of ~25 ppm CO2 was measured. A low power metal oxide sensor (~100 mW) was developed to detect volatile organic compounds (VOCs) in the breath, for disease detection and investigation of the variation of inter-individual metabolism processes. The device was sensitive to acetone (100 to 300 ppm, which is a biomarker for type-I diabetes). Other VOCs, such as NO2 were tested (10 to 250 ppb). Further work includes investigating the inter-individual variance of metabolism processes, for which the metal oxide sensor would be well-suited. Software was developed to operate the gas testing rig and acquire sensor output data in real-time. An application was written for smartphones to enable EE measurements with the breath analyser, outside of a laboratory environment. Three hand-held analysers were constructed and tested with a trial of 10 subjects. A counterpart (benchmark) unit with medical grade commercial sensors (cost of ~£2500) and hospital respiratory rooms (reference) were included in the trial. The newly developed analysers improved upon the performance of the benchmark system (average EE measurement error +2.4 % compared to +7.9 %). The affordable device offered far greater accuracy than the traditional method often used by practitioners (predictive equations, error +41.4%). It is proposed a set of periodic (hourly) breath measurements could be used to determine daily EE. The EE analyser and associated low-cost sensors developed in this work offer a potential solution to halt the growing cost of an obese population and provide point-of-care health management.
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El-Jaby, Samy. "[An]Illustrated Re-visitation of Energy Transfer and Energy Absorption in Photon Interactions with Matter." Thesis, McGill University, 2009. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=95609.
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This thesis revisits the processes of energy transfer and energy absorption in photon interactions with matter with particular focus paid towards the calculation of the mass energy transfer coefficient and the mass energy absorption coefficient. The concepts behind these two coefficients have been well enunciated, however, available references do not lend themselves to serve as a visual aid to promote better understanding of the dosimetric quantities related to energy transfer and energy absorption, as well as their relationship to the photon energy and absorber atomic number. An illustrative approach is utilized in explaining the functional relationships between the relevant quantities inherent to these coefficients. In addition, a Photon Energy Transfer and Absorption Coefficients (PETAC) software has been developed to allow for a graphical, dynamic, and interactive format upon which the student of medical physics may observe and intuitively grasp the processes behind energy transfer and energy absorption in photon interactions with matter .Cette thèse révise les procédés de transfer et d'absorbtion d'énergie causés par l'interaction des photons avec la matière en accordant une attention toute particulière aux calculs du coefficient de transfert d'énergie massique et du coefficient d'absorbtion d'énergeie massique. Les concepts définissant ces coefficients son déjà bien établis, mais ils ne proposent pas une excellente comprehension des quantités dosimétriques reliées au transfert et à l'absorbtion d'énergie de même qu'à la relation existant entre l'énergie photonique et le numéro atomique absorbé. Une approche nouvelle et visuellement coherente est proposée afin de metre en lumière une relation fonctionnelle entre ces quantités et ces coefficients. De plus un application informatique, graphique, dynamique et interactive appelée PETAC (Photon Energy Transfer and Absorbtion Coefficients) à été devellopee pour aider les étudiants en physique médicale a visualiser et déduire intuitivement les lien entre les processus de transfert d'énergie, et d'absorbtion d'énergie dû à l'interaction des photons avec la matière .
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Flett, Graeme. "Modelling and analysis of energy demand variation and uncertainty in small-scale domestic energy systems." Thesis, University of Strathclyde, 2017. http://digitool.lib.strath.ac.uk:80/R/?func=dbin-jump-full&object_id=27959.
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A range of different scenarios have been predicted for future UK energy supply. While there is significant uncertainty, all expect an increase in small-scale distributed generation integrated in constrained or independent networks and with predominantly domestic consumers. This reduction in system scale has not, however, driven a significant change in design practices, with deterministic models and rules-of-thumb prevalent. Little consideration has been given to how the specific household characteristics and the size of system impact on demand level and timing, the degree of uncertainty in anydemand prediction, and how design practices should change to reflect this. The main contribution of the presented work has been to address this. To allow the variation and uncertainty to be quantified; a highly differentiated, probabilistic, bottom-up demand model has been developed for electrical and hot water use. The 1-minute resolution model incorporates an enhanced Markov chain occupancy model and is based on a newly developed discrete-event approach for occupant-initiated demands. Utilising realistic factoring for appliance ownership, income, occupancy, and random energy-use behaviours, the model has been shown to capture the range of potential household demands. Assessment that the developed model, and any existing model calibrated using group data, tended to rapidly converge to the group average basis, prompted further method development to improve the model's performance in capturing individual household demand behaviours. Analysis of both existing data and the demand model output has shown that energy system demand can vary significantly based on socio-economic characteristics and the types of households supplied. It also highlights that demand uncertainty for individual households can exceed an order of magnitude, even if household characteristics are known. As the system scale is increased, the level of overall demand uncertainty remains significant to at least 200 household systems. A method has therefore been developed that allows multiple runs of the probabilistic model to be reduced to a representative subset, which can be used to analyse potential energy system performance scenarios probabilistically using existing optimisation tools.
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Staples, Elizabeth M. "The effects of R(+)-lipoic acid supplementation on regulation of human skeletal muscle pyruvate dehydrogenase." Online Access "Search by author or title", 2005. http://www.oregonpdf.org.
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Kinnen, A. J. "Electron and photon colllisions with atoms and ions using an intermediate energy R-matrix approach." Thesis, Queen's University Belfast, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.426763.
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Bryjko, Lilianna. "SA-CASSCF and R-matrix calculations of low-energy electron collisions with DNA bases and phosphoric acid." Thesis, University of St Andrews, 2011. http://hdl.handle.net/10023/2608.
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The research presented in this thesis was carried out as part of a collaboration between the groups of Dr Tanja van Mourik at the School of Chemistry, University of St Andrews and Professor Jonathan Tennyson at the Department of Physics and Astronomy at University College London. This thesis presents State-Averaged Complete Active Space Self Consistent Field (SA-CASSCF) calculations on nucleic acid bases, deoxyribose and phosphoric acid H₃PO₄). In the case of uracil, for comparison, Multireference Configuration Interaction calculations were also performed. The SA-CASSCF orbitals were subsequently used in R-matrix electron scattering calculations using the close-coupling model. Of major importance for obtaining accurate SA-CASSCF results is the choice of the active space and the number of calculated states. Properties such as the electronic energy, number of configurations, excitation energy and dipole moment were considered in the choice of active space. Electron-collision calculations were performed on two of the most stable isomers of phosphoric acid, a weakly dipolar form with all OH groups pointing up and a strongly dipolar form where one OH group points down. A broad shape resonance at about 7 eV was found for both isomers. Ten-state close-coupling calculations suggest the presence of narrow, Feshbach resonances in a similar energy region. Elastic and electronically inelastic cross sections were calculated for both isomers. The R-matrix calculations on uracil were done by the group from UCL. R-matrix calculations are currently being done on guanine. Scattering calculations on the other DNA bases will be performed in the near future.
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Champagne, Christian. "Characterizing and optimizing the TITAN facility from energy spread determinations with a retarding energy field analyzer." Thesis, McGill University, 2010. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=86571.
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The TITAN (TRIUMF's Ion Trap for Atomic and Nuclear science) experiment uses a Measurement Penning Trap (MPET) to perform high precision mass measurements (∆m/m ≈ 10e-8) on short-lived (t1/2 ≈ 10 ms) isotopes. The ISAC (Isotope Separation and ACceleration) facility provides a 60 keV rare isotope beam to the experiments. A Radio-Frequency Quadrupole (RFQ) ion trap cools and bunches the incoming radioactive beam. An Electron Beam Ion Trap (EBIT) charge breeds the ions to a high charged state q. Since the MPET mass resolution is proportional to the charge state q, an improvement up to two orders of magnitude can be achieved. Further enhancements are obtained by the reduction of the uncertainty on the MPET measurements, such as from the ion bunch longitudinal kinetic energy spread. A Retarding Field energy Analyzer (RFA) was designed and constructed to measure this uncertainty.An energy resolution ∆E/E ≈ 10e-3 was expected from to simulated RFQ ion extraction longitudinal energy spread measurements. An experimental energy resolution ∆E/E = 2.4 x 10e-3 was obtained. Suggestions to improve the energy resolution are provided. Two testing sessions were undertaken using the RFQ and TITAN ion source to provide a singly charged pulsed ion beam. The first session used a 6Li+ beam with a 1 - 4 keV energy range. The RFA collimating slits were removed to insure the beam entered the RFA, increasing the energy resolution to ∆E/E = 5 x 10e-3. An energy resolution ∆E/E = (1.4 ± 0.5) x 10e-2 was obtained from the longitudinal energy spread measurements as a function of the beam energy. No correlation between the RFQ buffer gas pressure and the longitudinal energy spread was observed. The second session used 6;7Li, 23Na, 39;41K beams with a 1 - 5 keV energy range and the slits were reincorporated. A linear correlation with the RFQ extraction potentials magnitude is visible with both 2.5 keV 7Li+ and 23Na+ beams. No correlations between the RFQ buffer gas pressure, the space charge, beamgate size and beam composition with respect to the longitudinal energy spread were otherwise found. Further reduction of the RFA energy resolution is necessary to resolve longitudinal energy spread variations under different RFQ parameter settings.
L'expérience TITAN (Piège ionique pour la science atomique et nucléaire de TRIUMF) utilise un piège Penning (MPET) pour effectuer des mesures de masse de haute précision (∆m/m ≈ 10e-8) sur des isotopes radioactifs de courte demi-vie (t1/2 ≈ 10 ms). L'installation ISAC (Isotope Separation and Acceleration) à TRIUMF produit un 60 keV faisceau d'isotopes rares vers divers expériences. Un piège ionique quadrupôle linéaire à radio-fréquences (RFQ) refroidit et accumule le faisceau d'ions radioactifs. Un piège ionique à faisceau d'électrons (EBIT) augmente la charge ionique des ions simplement chargés à une haute charge q. Puisque la résolution de masse de MPET est proportionnelle à la charge ionique q, une augmentation de la résolution jusqu'à deux ordres de grandeur est possible. Des améliorations additionnelles sont fait par la réduction des sources d'erreurs sur les mesures du MPET, comme la dispersion longitudinale de l'énergie cinétique des ions pulsés. Un analyseur d'énergie cinétique à champ retardé (RFA) fut conçu et construit dans le but de mesurer cette erreur.
Une résolution énergétique ∆E/E ≈ 10e-3 fut visée à la suite des résultats obtenus de simulations numériques de l'extraction d'ions du RFQ. Une résolution énergétique expérimentale ∆E/E = 2.4 x 10e-3 a été obtenue. Des suggestions pour améliorer la résolution énergétique sont données. Le RFA fut testé au cours de deux séances en utilisant le RFQ et la source d'ions de TITAN pour fournir un faisceau d'ions simplement chargés. Durant la première séance, un faisceau de 6Li+ avec énergies entre 1 et 4 keV fut utilisé. Les fentes du collimateur furent enlevées pour assurer que le faisceau pénètre dans le RFA, augmentant la résolution énergétique à ∆E/E = 5 x 10e-3. Une résolution énergétique ∆E/E = (1.4 ± 0.5) x 10-e2 a été obtenue de la relation entre la dispersion longitudinale de l'énergie cinétique et de l'énergie cinétique du faisceau. Aucune corrélation entre la pression du gaz tampon du RFQ et la dispersion longitudinale de l'énergie cinétique a été observée. La seconde séance utilisait des faisceaux de 6;7Li, 23Na, 39;41 K avec des énergies cinétiques entre 1 et 5 keV et les fentes du collimateur furent ré-incorporées. Une corrélation linéaire avec la grandeur des potentiels extraction du RFQ fut observée avec les deux faisceaux de 7Li+ et 23Na+ à 2.5 keV utilisés. Aucune corrélation entre la charge spatiale, pression du gaz tampon du RFQ, la durée du barrière d'ions et la composition du faisceau avec la dispersion longitudinale de l'énergie cinétique furent autrement notées. Des réduction supplémentaires à la résolution énergétique du RFA sont nécessaire pour observer des variations dans la dispersion longitudinale de l'énergie cinétique du faisceau sous différent paramètres du RFQ.
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Hung, Aaron. "ENERGY EFFICIENCY AND STATISTICAL ANALYSIS OF BUILDINGS AT CASE WESTERN RESERVE UNIVERSITY." Case Western Reserve University School of Graduate Studies / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=case1446477944.
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Jariwala, Vibhakar G. "Cyclic energy storage in paraffin wax." Thesis, McGill University, 1985. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=63366.
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Mohd, Warip Mohd Nazri Bin. "Energy efficient core optical IP networks." Thesis, University of Strathclyde, 2012. http://oleg.lib.strath.ac.uk:80/R/?func=dbin-jump-full&object_id=18958.
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The Internet has become an integral part of modern societies fuelling ever growing opportunities for the provision of new advanced services which better respond to quickly changing societal needs. Previously the deployment of such services have led to significant increases in energy consumption which is in strong contrast with the global drive for a greener and more energy efficient environments. Network infrastructures are required which support these growing needs but at the same time remain zero-carbon emission complaint. Green photonic network designs centre on techniques to reduce and conserve energy within multilayer network scenarios. In this Thesis, hibernation strategies are proposed where network configurations form selective group of nodes, segmentation of links and partitioning of the light paths within connections to enable "sleep" modes. The strategy is founded on the optimisation and improved power management through a control algorithm implemented as a modification of the Generalized Multi-Protocol Label Switching (GMPLS) signalling and routing protocol. The impact of the strategy on network utilization, number of wavelengths, number of connection requests, number of nodes, network connectivity degree, and power ratio in IP routers has been evaluated on representative optical networks using a simulation framework established using OMNeT++. A trade-off is observed between energy consumption and network performance as a result of hibernation; evaluation of this methodology indicates potential reduction in energy power consumption from 30% up to 75% at the expense of reduced network performance.
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Halbert, Andrea Sarah. "A detailed analysis of energy tax incentives in South Africa." Diss., University of Pretoria, 2016. http://hdl.handle.net/2263/60495.
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Coupled with the issue of promoting energy efficiency in South Africa is the need to focus on the source of energy production. The country's excessive burning of coal resources has been linked to the global warming crisis.
To address this energy crisis, taxpayers can be encouraged to play an important role in moving the country towards a position of energy stability by conserving energy or decreasing their energy consumption, or contributing towards the research and development of energy-efficient processes as well as cleaner forms of energy.
This study analyses the energy-related tax incentives that are currently legislated and available to South African taxpayers and discusses the feasibility of taking advantage of these incentives. The study may provide guidance to taxpayers that have decided to invest in renewable energy sources and will discuss some of the advantages and perceived challenges facing the renewable energy industry.
This study also provides a worked example that illustrates a detailed calculation of the energy tax saving incentive set out in section 12L of the Income Tax Act, No. 58 of 1962.
A case study guides taxpayers though the practical process of applying for and calculating their energy-saving tax deduction. The case study may be used as a point of reference for taxpayers planning to implement the section 12L energy efficiency tax incentive for the first time and may highlight complexities and concerns they should consider.Mini Dissertation (MCom)--University of Pretoria, 2016.
Taxation
MCom
Unrestricted
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Hasan, Mainul. "Cyclic phase change : energy storage and recovery." Thesis, McGill University, 1988. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=75832.
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This research concerns the alternate melting and freezing of a phase change material (PCM) to simulate cyclic operation of phase change energy storage systems. A one-dimensional conduction-controlled phase change model was derived for a PCM slab. One surface of the slab is subjected to successive periods of constant temperature above and below the fusion temperature while the other surface is adiabatic. A front-tracking, self-marching finite-difference scheme was developed to solve the resulting multiple moving boundary problem. Temperature fields within each solid and liquid region were decoupled with an explicit treatment of the interfacial energy balances. Temperatures at all grid points were obtained by an explicit finite-difference scheme except for the grid points in the immediate neighborhood of each phase front. Temperatures at the latter points were computed from a quadratic temperature profile with time-dependent coefficients. Dynamic simulations were carried out until a periodic steady state was attained when the energy stored during a melting period and the energy recovered in the following freezing period were equal and remained invariant for subsequent periods. The cumulative energy transferred, the instantaneous heat flux, the interface locations and the temperature profiles were obtained for three modes of operation: (1) equal thermal swings with equal melting and freezing periods, (2) equal periods with unequal swings and (3) equal swings with unequal periods. Experiments were carried out by alternately melting and freezing n-octadecane in a thin rectangular cell. When the cell was horizontal and heat was transferred from above, the moving interfaces were planar and there was excellent agreement between numerical and experimental results. When the cell was tilted, the interfaces were not planar and the energy transferred at the periodic steady state increased with the angle of inclination, reaching a maximum with heat transfer from below.
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Baksi, Soham. "Essays on environmental policies, corruption, and energy." Thesis, McGill University, 2005. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=100316.
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This thesis consists of four essays. The first essay looks at pollution taxation under capital mobility, and analyzes the role of pre-commitment by countries to their pollution tax rate. A polluting firm sells its product in two countries, and can locate and produce in a single country or in both countries. Due to the discrete-choice nature of the firm's location problem, the countries' welfare functions are discontinuous in their pollution tax rate. We show that when the countries cannot pre-commit to their pollution tax, the firm can still engender tax competition between them by strategically locating in both the countries. Moreover, pre-commitment pollution taxation may not be welfare improving for the countries, although it always makes the firm better off.The second essay studies the effect of liberalization on corruption. Corruptible inspectors enforce an environmental regulation on firms, and are monitored by an honest regulator. Liberalization not only increases the variety of goods and the marginal utility of accepting a bribe, but also puts pressure on the regulator to curb corruption. The interaction of these two effects can cause corruption to initially increase with liberalization, and then decrease beyond a threshold. Moreover, equilibrium corruption is lower when the regulator is able to pre-commit to her monitoring frequency.
The third essay analyzes optimal labeling (information revelation) procedures for hidden attributes of credence goods. Consumers are heterogeneous in their preference for the hidden attribute, and producers can either self-label their products, or have them certified by a third party. The government can impose self or third-party labeling requirements on either the "green" or the "brown" producers. When corrupt producers can affix spurious labels, the government needs to monitor them. A mandatory self-labeling policy is shown to generally dominate mandatory third-party labeling.
The fourth essay develops formulas for computing the economy-wide energy intensity decline rate by aggregating sectoral energy efficiency improvements, and sectoral shifts in economic activities. The formulas are used to (i) construct plausible scenarios for the global rate of energy intensity decline, and (ii) show the restraining role of the "electricity generation" sector on the energy intensity decline rate.
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Murphy, Gavin Bruce. "Inverse Dynamics based Energy Assessment and Simulation." Thesis, University of Strathclyde, 2012. http://oleg.lib.strath.ac.uk:80/R/?func=dbin-jump-full&object_id=16928.
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The Standard Assessment Procedure (SAP) is the UK Government’s approved methodology for assessing the energy ratings of dwellings. SAP is a calculation method based upon empirical relations from measured data. A yearly calculation was used in SAP until the release of SAP 2009, which employs monthly calculations. SAP has moved from using a large time step with a coarse time resolution to a smaller time step with a medium time resolution. Rising CO2 emissions from dwellings advocate that properties designed in a sustainable method will become commonplace in the future. In tandem with enhanced sustainability, dwellings will increasingly be designed with implementations of renewable energy generation. The modelling of renewables in SAP has been highlighted as an area where SAP could benefit from additional research. Modelling future complex dwellings and systems will require an advanced calculation method which is capable of more detailed modelling and simulation; with a smaller time step which is measured in minutes and not months, producing results allowing more detailed analysis of energy performance. Dynamic Simulation Methods (DSMs) already exist which can operate at a very small time step. However with DSMs it is very difficult to make a comparison with SAP as the temperatures used in SAP are not well understood. To calculate energy consumption the SAP methodology guarantees that a standard occupancy temperature profile is met perfectly. A dynamic method which also guarantees the SAP standard occupancy temperature profile is required. This is difficult in complex DSMs as their control algorithms are often inadequate to optimise the heating system to guarantee that a temperature is met perfectly. The contribution to knowledge detailed in this thesis is the development of a novel SAP compliant advanced dynamic calculation method (IDEAS) v which guarantees that the SAP standard occupancy temperature profile is perfectly tracked and is also calibrated with SAP. The Inverse Dynamics based Energy Assessment and Simulation (IDEAS) method employs the perfect inverse control law RIDE to guarantee that the SAP standard occupancy temperature profile is met. IDEAS produces SAP compliant results and allows confident (i.e. calibrated in SAP) predictions to be made regarding the impact of novel heating and renewable energy systems. Researched in depth are the temperatures used in SAP, leading to analysis of the implications of tracking air temperature and various comfort temperatures. A focused evaluation of the treatment of renewables in SAP and DSMs is also presented, leading to suggestions which were implemented into the SAP framework. The role of real life monitoring in the energy assessment process is highlighted with monitored studies conducted. Also in this thesis case studies applying IDEAS to buildings with renewable heating systems are described. The IDEAS method employs SAP as an exemplar steady state calculation to highlight the successful use and calibration of a new advanced Inverse Dynamics based symbolic method. The philosophy, research and equations derived in IDEAS are presented in this thesis demonstrating their use in Microsoft Excel and Matlab / Simulink environments. The IDEAS methodology is transparent and portable. IDEAS can be applied to other methodologies, such as those employed by PHPP and SBEM (by carrying out a calibration process), and also to different simulation environments such as ESP-r and ESL (by adopting the IDEAS equations in those methods). The contribution to knowledge of IDEAS is demonstrated in this thesis by the development of the method and the use of SAP as a comparator. The IDEAS method has many uses outwith SAP which are highlighted in the cases studies and future work sections of this body of work.
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Banks, Charlotte. "Operational practices to improve ship energy efficiency." Thesis, University of Strathclyde, 2015. http://oleg.lib.strath.ac.uk:80/R/?func=dbin-jump-full&object_id=24931.
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The aim of this research was to contribute towards energy efficiency in the shipping industry through improved operational practices that reduce fuel consumption, hence exhaust emissions and the amount of carbon dioxide released into the atmosphere. This is in line with meeting global emission reduction targets and the mitigation of Climate Change. A critical review is presented that was undertaken to understand Climate Change as a driver towards energy efficiency within the maritime industry. The regulations are reviewed along with existing operational practices and the enablers and barriers towards improvements. Several field studies that were undertaken to further examine current practices and barriers are described, including a questionnaire identifying the opinions and perceptions of seafarers. Based on conclusions from the review and field studies, a Framework for improving the energy efficiency of ship operations is presented. The proposed Framework identifies that for practical solutions in the industry, human factors must be addressed in parallel with technical advances. The following features of the Framework to enable improvements are identified to be: a) Ship Operational Performance Monitoring for performance feedback distribution and supporting operational strategic decisions and b) updates to existing Operating Procedures. However, it is proposed that these features cannot be achieved on a wide scale without first the development of the following elements: a) Maritime Education and Training on energy efficiency; b) Analysis of ship Operational Profiles; c) A Ship Operational Performance Prediction (SOPP) Model. These three elements were developed and are described in this thesis. The developments described in this thesis were enabled by the collection of operational datasets (namely Ship Reports, also commonly known as Noon Reports) and information for 21 case study ships; including tanker, container and bulk carrier ships. The collection of this data was enabled by field study visits. Regarding the development of Maritime Education and Training on energy efficiency, three course curriculums are proposed. The training material developed for the Energy Resource Management course is then described. The results from the analysis of Operating Profiles for the 21 case study ships are presented. Typical operating practices are identified along with the opportunities for energy efficiency improvements. The Ship Operational Performance Prediction Model was developed using the Ship Report dataset for a case study tanker ship. The model predicts the ship's main engine brake power and fuel consumption with adequate accuracy and allows for assessment of the impacts due to different operating conditions. Specifically, a function to account for time dependent performance changes is developed so that the hull and propeller surface degradation and fouling are taken into consideration. Finally, the utilisation of the developed elements within the proposed Framework to improve energy efficiency is discussed, so that the importance of methods utilising Ship Report operational datasets becomes evident.
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McGuire, Colin. "Energy efficient network for rural broadband access." Thesis, University of Strathclyde, 2014. http://oleg.lib.strath.ac.uk:80/R/?func=dbin-jump-full&object_id=24705.
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This thesis proposes and discusses aspects of a low-cost wireless network called "Hopscotch" as a potential solution to the rural broadband problem. Providing broadband internet access to rural locations is challenging due to the long distances between internet backbone and households, the sparse population density and difficult terrain. Hopscotch uses a network of renewable powered base stations, termed "WindFi", connected by point-to-point links, to deliver internet access to rural communities. A combination of frequency bands are used within Hopscotch. Standard IEEE 802.11 5 GHz WiFi access technology is used for high capacity links, and an ultra high frequency TV "white space" spectrum overlay in the 600-800 MHz band provides long distance coverage. The advantages of "white space" spectrum are demonstrated for a rural wireless scenario; reducing the number of base stations required to cover a community and decreasing the transmit power required to create long distance links over challenging terrain. The use of renewable power allows WindFi base stations to be well placed to serve a community, irrespective of available infrastructure. The power system is the biggest cost component of the base station therefore the system must be carefully sized. The design of the WindFi base station is presented and the specification of the renewable power generation system validated with operational data. To reduce the energy required, and therefore the demand on the renewable power system, aspects of energy use within the base station are considered. Models of the power consumption and data rate selection for radios used in Hopscotch are presented. Hopscotch trials have been running on the Scottish islands of Bute and Tiree. Measurement based models of household distribution, daily network internet traffic and large-scale path loss for a rural community are presented based on trial results, which are useful for simulating rural broadband networks. To minimise the power consumption of the WindFi base station, an energy optimisation is presented for a Hopscotch scenario. Dynamically altering the assignment of users between two overlay radio access networks, based on the instantaneous capacity required, is shown to reduce power consumption. The optimum assignment between the networks to maximise individual user throughput is also presented.
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Ariwoola, Raheem Taiwo. "Use of Drone and Infrared Camera for a Campus Building Envelope Study." Digital Commons @ East Tennessee State University, 2016. https://dc.etsu.edu/etd/3018.
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Presently, there are concerns that buildings in the USA under-performs in terms of energy efficiency when compared with the original design specifications. A significant percentage of the energy loss in these buildings is associated with the building’s envelope. This study provides a qualitative and analytical understanding of the R-value, which indicates the thermal performance of the elements that make up a building envelope. Infrared thermography is used as a methodology to assess the thermal performance of envelopes of ten buildings on East Tennessee State University Campus. A Fluke Ti25 infrared hand-held camera and a DJI phantom-2 drone mounted with FLIR Vue Pro infrared camera were used for data collection. Data analyses were carried out using ‘Smartview’ and ‘FLIR Reporter Pro’ software. The data analyses revealed energy loss, insulation deficiencies, the associated energy costs of the inefficiencies and the potential savings that could result from correcting these deficiencies in the evaluated building’s envelopes.
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Saunders, Christine V. "Role of glucose, acetate and plasma in the maintenance of mitochondrial function, energy metabolism and cell integrity during platelet storage in additive solutions." Thesis, Cardiff University, 2012. http://orca.cf.ac.uk/47076/.
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A potential benefit of the use of artificial media for the suspension of platelets as concentrates is a reduction of the morphological, functional and metabolic changes observed in platelets during storage and collectively referred to as the platelet storage lesion (PSL). A better understanding of the nature of the PSL may suggest strategies for manipulation of the storage environment to improve platelet viability and efficacy posttransfusion. In this context, two principal considerations formed the basis for the study: · The hypothesis that apoptosis is a central mechanism responsible for the changes observed in the PSL. · The investigation of this hypothesis within the applied setting of improving the storage environment of platelet concentrates. The study investigated the role on the PSL of plasma protein (in the form of albumin), acetate and glucose in leucoreduced platelet concentrates suspended in a medium with minimal plasma. A 14-day storage study on platelet concentrates in either plasma or a 70:30 ratio of a commercial additive solution (SSP+Ô) and plasma provided an overview of platelet in vitro characteristics under standard storage conditions. The work led to targeted investigations into the nature of the cell death mechanism in platelet concentrates. Results suggested that in storage media with adequate energy stores, a Bcl-2 proteinmediated mechanism of cell death was viable, though possibly storage-time dependent and limited by pre-existing levels of anti-apoptotic Bcl-2 proteins in the platelets. Further studies would be required to determine if this mechanism is akin to caspasedependent apoptosis. In media lacking glucose, a mechanism more reminiscent of necrosis was observed, associated with decreased ATP levels, accelerated mitochondrial dysfunction, elevated intracellular free calcium and culminating in platelet disruption.
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Stier, Christian [Verfasser], and R. [Akademischer Betreuer] Reussner. "Adaptation-Aware Architecture Modeling and Analysis of Energy Efficiency for Software Systems / Christian Stier ; Betreuer: R. Reussner." Karlsruhe : KIT-Bibliothek, 2018. http://d-nb.info/116180174X/34.
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Ménard, Odette. "A solar climate control system using a water film flow to conserve energy in greenhouses /." Thesis, McGill University, 1991. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=60540.
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One of the greatest problems encountered in greenhouses and buildings with large glazing is control of the internal atmosphere. The inherent characteristic of these buildings to act as solar collectors is to be used effectively for collecting and storing the excess solar energy. A new type of glazed roof, a Solar Climate Control roof system, was designed as a means to cool the interior environment of the greenhouses during the daytime and to heat during the nighttime or on overcast days.A heat exchanger-storage system, using water as a thermal mass is included in the design of the Solar Climate Control system. A film of water flows on the inner surface of the roof and absorbs the direct solar heat radiation, acting then as a cooling agent. The energy absorbed may be reused for nighttime heating.
An efficient water dispersion pipe for the Solar Climate Control system was developed. The use of a soap solution rather than water alone for the Solar Climate Control water film system permitted a significant reduction in pumping rate and improved uniformity of the film.
A computer simulation model was run to determine the energy loads for both a conventional (double glazed roof) greenhouse and one equipped with the Solar Climate Control system. The Solar Climate Control system shows low operating cost and very good efficiency in heat removal.
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Smith, Nicola Anne Visocchi. "Decision support for new and renewable energy systems deployment." Thesis, University of Strathclyde, 2002. http://oleg.lib.strath.ac.uk:80/R/?func=dbin-jump-full&object_id=21192.
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The global requirement for sustainable energy provision will become increasingly important over the next fifty years as the environmental effects of fossil fuel use become apparent. Therefore, the issues surrounding integration of renewable energy supplies need to be considered carefully. The focus of this work was the development of a decision support framework that will aid the design of sustainable energy systems for the supply of electricity, heat, hot water and fuel for transportation. Issues requiring consideration in high percentage renewable energy systems include the reliability of the supply when intermittent sources of electricity are being used, and the subsequent necessity for storage and back-up generation. In order to allow the modelling of realistic integrated systems that supply the total energy needs of an area, the production of fuels derived from biomass and waste and their use in a variety of different plant types (e. g. vehicles, engines, turbines, fuel cells, electrolysers, heating and hot water storage systems) is an important consideration. The temporal nature of both intermittent electricity and derived fuel supplies must be taken into account in any analysis. Existing demand and supply matching software has been enhanced to allow the full analysis described. Generic algorithms have been developed to allow the behaviour of a comprehensive list of plant types and methods for producing derived fuels to be modelled, which require only available process and manufacturers' data. The program is flexible, generic and easy to use, allowing a variety of supply strategies to be analysed. This has been shown through the study of a small Scottish island, which highlights the importance of derived fuel production and use. This work has succeeded in developing a more complete tool for analysing the feasibility of integrated renewable energy systems. This will allow informed decisions to be made about the technical feasibility of supply mix and control strategies, plant type and sizing, suitable fuel production, and fuel and energy storage sizing, for any given area and range of supply options.
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Negrão, Cezar O. R. "Conflation of computational fluid dynamics and building thermal simulation." Thesis, University of Strathclyde, 1995. http://oleg.lib.strath.ac.uk:80/R/?func=dbin-jump-full&object_id=21238.
Full textAbstract:
The present work is a contribution towards the integration of building simulation tools in order to better represent the complexity of the real world. It attempts to overcome certain shortfalls of contemporary simulation applications with respect to indoor air flows. As a result, the evaluation of building energy consumption and indoor air quality is expected to be improved. Advanced fluid flow models (as employed within Building Thermal Simulation - BTS - and Computational Fluid Dynamics - CFD) with different degrees of detail were investigated and their modelling deficiencies identified. The CFD technique which defines the fluid flow on a micro scale was integrated into BTS in which fluid flow is described in a larger scale. The resulting combined approach strengthens the modelling potential of each methodology by overcoming their specific deficiencies. BTS's inability to predict air flow property gradients within a single space was surmounted and the difficult of estimating CFD boundary conditions are now supplied by BTS. The conflation approach is expected to be employed where gradients of indoor air flow properties can be considered crucial to the evaluation of thermal comfort and energy consumption. The BTS environment, ESP-r, was elected to perform the current work and a new CFD program, dfs, was specifically developed for the analysis of three-dimensional, turbulent, transient air flow. Finally, the two approaches were integrated. The integration work focuses on the CFD boundary conditions where the interactions of BTS and CFD take place; these occur at the inside zone surfaces and at the zone openings. Three conflation approaches were devised addressing different degrees of complexity and sophistication. The first one, involving the two types of zone boundaries, corresponds to a simple approach where the BTS and CFD systems exchange information without any direct interaction. The second approach consists of three other schemes to handle the thermal coupling at the internal zone surfaces. The third approach comprises coupling between the nodal network approach as employed by the BTS environment, and the continuity and momentum equations in the CFD technique. A validation methodology consisting of analytical validation, intermodel comparison and empirical validation is described and applied. The technique is shown to be adequate for modelling indoor air flows when compared to existing models. Three situations, covering the different types of air flows encountered within buildings are discussed to demonstrate the combined method's applicability when compared with the nodal network approach. Finally, general conclusions are presented and some possible future work is identified showing that the developed methodology is very promising.
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Bass, Jeremy Hugh. "The potential of combined heat and power generation, wind power generation and load management techniques for cost reduction in small electricity supply systems." Thesis, University of Strathclyde, 1987. http://oleg.lib.strath.ac.uk:80/R/?func=dbin-jump-full&object_id=21484.
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An evaluation is made of the potential fuel and financial savings possible when a small, autonomous diesel system sized to meet the demands of an individual, domestic consumer is adapted to include: (1) combined heat and power (CUP) generation. (2) wind turbine generation. (3) direct load control. The potential of these three areas is investigated by means of time-step simulation modelling on a microcomputer. Models are used to evaluate performance and a Net Present Value analysis used to assess costs. A cost/benefit analysis then enables those areas, or combination of areas, that facilitate the greatest savings to be identified. The modelling work is supported by experience gained from the following: (1) field study of the Lundy Island wind/diesel system. (2) laboratory testing of a small diesel generator set. (3) study of a diesel based CUP unit. (4) study of a diesel based direct load control system. (5) statistical analysis of data obtained from the long-term monitoring of a large number of individual household's electricity consumption. Rather than consider the consumer's electrical demand in isolation, a more flexible approach is adopted, with consumer demand being regarded as the sum of primarily two components: a small, electricity demand for essential services and a large, reschedulable demand for heating/cooling. The results of the study indicate that: (1) operating a diesel set in a CUP mode is the best strategy for both financial and fuel savings. A simple retrofit enables overall conversion efficiencies to be increased from 25% to 60%, or greater, at little cost. (2) wind turbine generation in association with direct load control is a most effective combination. (3) A combination of both the above areas enables greatest overall financial savings, in favourable winds resulting in unit energy costs around 20% of those of diesel only operation.
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Fletcher, Quinn. "The role of energy expenditure in resource acquisition and energy allocation in free-ranging North American red squirrels (Tamiasciurus Hudsonicus)." Thesis, McGill University, 2011. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=96992.
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Energy is a currency of life because all organisms must expend energy to survive and reproduce. I examined the central role that energy expenditure plays in the lives of free-ranging female North American red squirrels (Tamiasciurus hudsonicus) in Yukon, Canada. I found that energy acquisition while hoarding white spruce (Picea glauca) cones in autumn was characterized by a type III functional response; when cones were scarce, squirrels switched to hoarding mushrooms, whereas when cones were abundant, squirrels were unable to hoard more than a small proportion of the cones present in their territory. The strong satiation of cone hoarding supports the primary prediction of the predator satiation hypothesis for the evolution of masting in white spruce trees. I also determined the daily energy expenditure (DEE, kJ/day) of female squirrels using the doubly-labeled water technique during the activity stages of nonbreeding (winter and summer), lactation, and hoarding. The primary determinant of energy expenditure throughout the year was the activity stage that the individual was engaged in, with females having the highest energy expenditure during hoarding and lactation. Ambient temperature (Ta) during the sampling interval was the second most important determinant of energy expenditure, but counter to expectations based on thermoregulatory requirements, Ta was positively correlated with energy expenditure. Levels of DEE were positively correlated with an estimate of physiological somatic damage (plasma protein carbonyls). The somatic damage experienced by females during lactation was greater than that experienced by nonbreeding females during summer and winter. Levels of somatic damage were reduced during lactation if individuals had access to supplemental food, which was associated with squirrels having higher levels of total antioxidant capacity. High energy expenditure during lactation was correlated with increased reproductive success. Lactating females with higher DEE also had increased physiological somatic damage, but there was no relationship between lactation DEE and survival. My thesis establishes for the first time the intuitive importance of energy expenditure for determining energy acquisition and mediating life-history trade-offs between reproduction and survival.L'énergie est la devise de la vie puisqu'elle est nécessaire à tous les organismes vivants pour survivre et se reproduire. J'ai examiné le rôle central des dépenses énergétiques dans la vie des écureuils roux (Tamiasciurus hudsonicus) femelles en liberté au Yukon (Canada, 61 °N 138 °W) pendant qu'elles acquéraient leur énergie et l'attribuaient entre différentes activités favorisant leur survie et succès reproductif. Lorsqu'elles s'approvisionnaient de cônes d'épinette blanche (Picea glauca) à l'automne, leur acquission d'énergie correspondait à une réponse fonctionnelle de type III. Lorsque les cônes étaient rares, les écureuils changeaient pour s'approvisionner en champignons, alors que lorsque les cônes étaient abondants, les écureuils étaient seulement capables d'amasser une faible portion des cônes sur leur territoire. La satiété des femelles qui s'approvisionnaient en cônes supporte une des prédictions fondamentales de l'hypothèse de la satiété des prédateurs dans l'évolution de la production de cône en masse des épinettes blanches. J'ai aussi déterminé la dépense d'énergie quotidienne (DEE, kJ/jour) des femelles écureuils en utilisant la technique de l'eau doublement marquée lors des modes d'activité suivants : en période non reproductive (hiver et été), lactation, et approvisionnement. Le facteur le plus important pour déterminer la dépense énergétique tout au long de l'année était le mode d'activité de la femelle. Les femelles en approvisionnement et en lactation avaient les plus hauts niveaux de dépense énergétique. La température ambiante était le deuxième facteur en importance pour déterminer la dépense énergétique. Contrairement aux prédictions basées sur les contraintes de thermorégulation, la température ambiante était corrélée de façon positive avec les dépenses énergétiques. Les niveaux de DEE étaient corrélés de façon positive avec une estimation du dommage somatique physiologique (carbonyles de protéine plasmatique). Le dommage somatique des femelles lors de l'allaitement était plus important que celui des femelles non reproductives en été et en hiver. Par contre, les taux de dommage somatique durant l'allaitement étaient réduits lorsque les femelles avaient accès à des suppléments de nourriture, ce qui augmentait leur taux de capacité antioxydante totale. Les taux de dépense énergétique élevés étaient corrélés avec des taux de succès reproductif élevés. Les femelles allaitants qui avaient un taux élevé de DEE avaient aussi un taux élevé de dommage somatique physiologique. Il n'y avait pas de lien entre le DEE des femelles allaitants et leur survie. Ma thèse établit pour la première fois l'importance des dépenses énergétiques pour déterminer l'acquisition d'énergie et les compromis dans l'attribution de l'énergie entre la reproduction et la survie des écureuils roux femelles.
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Bertrand, Martine 1976. "Photon production in high energy heavy ion collisions." Thesis, McGill University, 2000. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=31196.
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The production of photons in the energy range of 0 to 3 GeV is discussed as a signature of the creation of a quark-gluon plasma in ultrarelativistic nuclear collisions. However, they are also created in the hadronic phase. Therefore I investigate the role of the pirho → pigamma and pio → pigamma reactions in the photon emission from hot hadronic matter, and I compare their respective importance. These reactions are known to be the leading contributions. For this purpose I use diverse effective chiral Lagrangians that are in accord with known empirical properties of strong interaction. Then I discuss the relevance of my work to heavy ion collisions.
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Ross, Michael. "Energy storage system scheduling in wind-diesel microgrids." Thesis, McGill University, 2010. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=95237.
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This thesis proposes a knowledge based expert system tool that can be used as an on- line controller for the charging/discharging of an energy storage system in a wind-diesel microgrid. The wind-diesel microgrid is modelled, and a typical energy storage system is implemented to test the functionality of the controller using hourly-discrete power val- ues. The results are compared against an offline optimization that was provided 24-hour lookahead wind values, as well as a controller that was implemented using artificial neural networks. The knowledge based expert system is then used to analyze the cost of energy, by means of a parametric analysis, consisting of varying the wind penetration, energy stor- age system power rating and energy rating to determine for which wind penetration values a storage system implementation would be technically and economically viable. Differ- ent storage technologies are tested in a one-year time frame to determine which would be best suited for this particular application. The energy storage systems are implemented as single-layer and dual-layer, in which the knowledge based expert system is modified for the latter analysis, in order to determine whether or not there are advantages to having a dual-layer storage system. Throughout these analyses, the flexibility of the knowledge based expert system controller to various energy storage systems and microgrid models is verified. It also demonstrates that, in a context of high base generation costs, energy storage can be a viable solution to managing wind power variations.Cette thèse propose un système expert avec une base de connaissance qui peut être utilisé comme un contrôleur lors de la charge et de la décharge d'un système de stockage d'énergie dans un micro-réseau éolien-diesel. Un micro-réseau éolien-diesel modèle est établi, et un stockage est installé pour tester les fonctionnalités du contrôleur en utilisant des valeurs de la puissance horaire. Les résultats sont comparés avec une optimisation utilisant 24 heures de valeurs en avance pour la vitesse du vent, et aussi avec un contrôleur basé sur un réseau de neurones artificiels. Le contrôleur système expert est ensuite utilisé pour analyser les coûts d'énergie d'une analyse paramétrique, en variant la pénétration du vent, la puissance nominale du stockage, et la capacité nominale du stockage. Cette analyse indique pour quelles valeurs de pénétration éolienne une mise en vre d'un stockage serait viable économiquement et techniquement. Différentes technologies de stockage sont testées afin de déterminer laquelle serait le mieux adapté pour cette application particulière. Les systèmes de stockage sont réalisés à l'aide d'un ou de plusieurs types de systèmes, et le contrôleur système expert est modifié en conséquence, afin de déterminer s'il y a des avantages à avoir ce type de stockage. Ces analyses montrent aussi que le contrôleur système expert a la capacité et la flexibilité de s'adapter à des technologies ainsi qu'à des micro-réseaux de différents types.
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Zaher, Obadah S. "Advanced control, identification and optimisation of energy systems." Thesis, University of Strathclyde, 2013. http://oleg.lib.strath.ac.uk:80/R/?func=dbin-jump-full&object_id=22632.
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An increased emphasis is being put on energy efficiency and reduction of carbon emissions. The importance of comfort and energy savings to building designers and occupants has driven the development of more efficient building technologies. This has led to building control engineers and researchers developing more advanced and efficient control strategies in attempts to maximize the potential of these technologies and improve the efficiency of existing technologies. The buildings industry has been slow to adopt these advanced control strategies however, due to complexity issues or increases in cost and commissioning time. In order to bridge the gap between advanced controller design and the buildings industry, it is necessary that the controller designs that are being developed remain low cost and simple to implement. Ultimately, the objective for the design of a controller for use in industry is a robust high performance controller that is easy to implement, requires minimal user in put and has low implementation and installation costs i.e. does not require extra/excessive costly hardware. The research presented in this thesis is focused on this problem and delivers solutions that satisfy these criteria. This thesis considers the development of a robust high performance heating, ventilation and air-conditioning (HVAC) control strategy that is capable of dealing with the complexities associated with modern building control whilst being a low cost solution which is easy to implement. When designing a HVAC control system, a number of difficulties are encountered which the control system must be able to deal with in order to ensure accurate set-point tracking (thermal comfort) and efficient energy usage. These include dealing with time delay, parameter uncertainty, nonlinearity, interacting multi-input multi-output (MIMO) systems, unknown system parameters (identification) and tuning/re-tuning. Throughout this thesis a number of novel contributions to knowledge a controller design methodologies have been developed in order to deliver solutions which overcome these problems whilst remaining practical enough for use in industrial applications. The methods developed are based on a practical approach to inverse dynamics controller design and come together as two distinct main controller design methodologies. Firstly, a novel Genetic Algorithm (GA) based auto-tuning algorithm for the Robust Inverse Dynamics Estimation (RIDE) controller design which accounts for modelling parameter uncertainty. Secondly, a novel robust system identification based inverse dynamics controller design which incorporates a novel dead-time compensation methodology within the inverse dynamics controller structure. This controller design is termed System Identification based Rate Compensated Inverse Dynamics (SI-RCID). The SI-RCID controller algorithm is an advanced controller design which is relatively easy to implement, requiring a similar level of user input as the initial design procedure for the popular self-tuning proportional integral derivative (ST-PID) controller designs. When applied to a nonlinear MIMO HVAC system, the SI-RCID controller shows a significant performance improvement when compared to traditional ST-PID control and a more advanced controller design recently developed in the literature.
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Bouchat, Amélie. "Energy dissipation in viscous-plastic sea-ice models." Thesis, McGill University, 2014. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=121351.
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In viscous-plastic (VP) sea-ice models, small deformations are approximated by irreversible viscous deformations, introducing a non-physical energy sink. As the spatial resolution and the degree of numerical convergence of the models increase, linear kinematic features (LKFs) are better resolved and more states of stress lie in the viscous regime. Energy dissipation in the non-physical viscous regime therefore increases. We derive a complete kinetic energy (KE) balance for sea ice, including separate plastic and viscous energy sinks to study energy dissipation. The main KE balance is between the energy input by the wind and the dissipation by the water drag and the internal stresses (dissipating respectively 87\% and 13\% of the energy input on an annual average). The internal stress term is mostly important in winter when ice-ice interactions are dominant. The energy input that is not dissipated locally is redistributed laterally by the internal stresses in regions of dissipation by small scale deformations (LKFs). Of the 13\% dissipated annually by the internal stress term, 93\% is dissipated in friction along LKFs (14\% in ridging, 79\% in shearing) and 7\% is stored as potential energy in ridges. For all time and spatial scales tested, the frictional viscous dissipation is negligible compared to the frictional plastic dissipation (between 10 to 1000 times smaller). This conclusion remains valid when the spatial resolution and the numerical convergence of the simulations are increased. Overall, the results confirm the validity, from an energy point of view, of the VP approximation.La plupart des modèles de dynamique de glace marine en Arctique présentement utilisés dans la communauté scientifique sont basés sur une formulation des déformations correspondant aux matériaux viscoplastiques (VP). Les modèles VP font l'approximation que les petites déformations élastiques (réversibles) peuvent être remplacées par des déformations visqueuses (irréversibles), ce qui représente un nouveau puits d'énergie fictif dans les modèles. L'énergétique des modèles de glace est affectée par la résolution spatiale du réseau, ainsi que par le nombre d'itérations requises pour la résolution des équations non-linéaires gouvernant le système. Plus le nombre d'itérations et la résolution sont élevés, plus les lignes de fractures (déformations plastiques) sont bien définies. Les points de maille auparavant en régime plastique migrent donc vers le régime visqueux (non physique) en augmentant ainsi l'énergie perdue dans ce mode de déformation. Nous formons l'équation de la conservation de l'énergie cinétique pour étudier la dissipation d'énergie dans les modèles VP de glace marine. La dissipation d'énergie dans les déformations est séparée en deux puits distincts pour la dissipation d'énergie par les déformations visqueuses et par les déformations plastiques, afin d'évaluer la contribution du mode non physique à la balance énergétique. Pour toutes les échelles spatiales et temporelles étudiées, la dissipation par les déformations visqueuses est négligeable par rapport à la dissipation par les déformations plastiques, ce qui confirme la validité l'approximation VP d'un point de vue énergétique.
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Hamzah, Sareena Hanim. "Impact of glycaemic index of high carbohydrate diets on exercise energy metabolism and capacity and fasting concentration of plasma lipids in healthy physically active individuals." Thesis, University of Glasgow, 2011. http://theses.gla.ac.uk/2632/.
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The present thesis describes the impact of glycaemic index of high carbohydrate diets consumed for 5 days on exercise energy metabolism and capacity and fasting plasma lipids in healthy physically active individuals. The thesis consists of a literature review (Chapter 1), general methods (Chapter 2), four experimental chapters (Chapter 3-Chapter 6) and general discussion and conclusion (Chapter 7). Chapter 3 presents a pilot study aimed to investigate whether high carbohydrate meals with high and low glycaemic index of foods present within meals developed by using the glycaemic index values from the published glycaemic index tables, produce significant differences in postprandial glucose response. Eight healthy active women consumed prescribed high carbohydrate diets with either high or low glycaemic index in a randomised counterbalanced order. The experimental meals which consisted of breakfast, morning snack and lunch were consumed after an overnight fast. Plasma glucose responses were measured at baseline and every 30 minutes for 300 minutes after baseline. We concluded that high carbohydrate meals with high and low glycaemic index prescribed using the glycaemic index values from the existing glycaemic index tables in the literature produced a significant difference in postprandial plasma glucose responses. Thus, for further studies high carbohydrate diets with high and low glycaemic index were developed using glycaemic index values from available glycaemic index tables. The aim of Chapter 4 and Chapter 5 was to investigate the extent to which the glycaemic index of high carbohydrate diets consumed for 5 days reduces the rate of fat oxidation during endurance exercise and exercise capacity during running conducted in the fasted state in men and women. To determine this, 9 healthy physically active men (Chapter 4) and 9 healthy physically active women (Chapter 5) performed three treadmill runs to exhaustion at 65% max after their habitual diet, after 5 days on a high carbohydrate high glycaemic index diet, and after 5 days on high carbohydrate low glycaemic index diet, in a randomised counterbalanced order. Blood samples for the measurements of glucose, insulin, glycerol and non-esterified fatty acids, and expired air samples for the measurements of the rates of fat and carbohydrate oxidation were obtained at 15, 30, 45, 60, 75, 90 minutes and at the point of exhaustion. Running capacity was measured as time to exhaustion and distance covered. It was found that in both men and women, the extent to which high carbohydrate diets consumed for 5 days reduced the rate of fat oxidation during running in the fasted state was not influenced by the glycaemic index of the diet, and that glycaemic index of high carbohydrate diets consumed for 5 days had no impact on running capacity. Chapter 6 aimed to investigate the impact of the consumption of high carbohydrate diets with high and low glycaemic index for 5 days on fasting plasma concentration of lipids, insulin sensitivity and biomarkers for endothelial function (i.e. intercellular adhesion molecule-1 and vascular cell adhesion molecule-1) in physically active individuals. Fasting blood was collected from 17 healthy individuals on three occasions in a randomised counterbalanced order: after consuming habitual diet, after 5 days on high carbohydrate high glycaemic index diet and after 5 days on high carbohydrate low glycaemic index diet. It was found that the extent to which high carbohydrate diets consumed for 5 days increases fasting plasma concentration of triglyceride and reduces the concentration of high density lipoprotein cholesterol was not influenced by the glycaemic index of the diets. It was also found that glycaemic index of high carbohydrate diets consumed for 5 days had no impact on insulin sensitivity or on biomarkers of endothelial activation. In conclusion, consideration of the glycaemic index of high carbohydrate diets consumed by physically active healthy men and women for 5 days has no impact on insulin sensitivity and fasting concentration of plasma lipids, it does not influence the rate of fat oxidation induced by high carbohydrate diets during running conducted in the fasted state and has no influence on running capacity. Thus, when physically active individuals increase carbohydrate intake for the purposes of muscle glycogen accumulation, consideration of the glycaemic index is not important. Future studies are needed to determine whether the glycaemic index of high carbohydrate diets modify exercise energy metabolisms in top grade athletes.
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Chowdhury, Sharif Ahmed. "Protein utilization during energy undernutrition in sheep." Thesis, University of Aberdeen, 1992. http://digitool.abdn.ac.uk/R?func=search-advanced-go&find_code1=WSN&request1=AAIU546791.
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The aim of the present work was to study the protein utilization during energy undernutrition in sheep. In four different trials, the effects of varying levels of protein with submaintenance amounts of energy on the energy &'38 N balances of sheep were studied using the intragastric infusion technique and the respiration chamber. The effects of change in energy and protein supply on plasma metabolites and hormonal concentrations were also studied. When animals were given protein well in excess of their maintenance requirement with little or no non-protein energy, they attained positive N balance although they were in negative energy balance, apparently by efficient utilization of endogenous energy (presumably body fat). As body fat was used to fuel the energy needed for protein retention, fat and protein deposition were negatively correlated. However, at very high level of casein infusion, the oxidized component of the supplied protein can contribute up to 36&'37 of the total ME requirement. About 16 kJ of endogenous energy was used for each g of protein accretion. The efficiency of endogenous energy utilization ranged between 0.56 to 0.60. There was no clear evidence, that there is any minimum level of body fatness which is necessary before body fat can be utilized to support protein retention during exogeneous non-protein energy restriction. Protein utilization during exogenous energy restriction was found to be more affected by the growth potential than the adiposity of the animal. Both fasting-heat production &'38 N excretion were reduced when the glucogenic needs of animals were met. Similarly plasma glucose, -hydroxybutyrate and free fatty acids concentrations were not affected by the energy status of the animals, when glucose requirements of the animals were met.
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Nojiri, Shin'ichi, and Sergei D. Odintsov. "Modified f (R) gravity consistent with realistic cosmology: From a matter dominated epoch to a dark energy universe." American Physical Society, 2006. http://hdl.handle.net/2237/8840.
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Gerst, Kacy J. (Kacy Jean). "Evaluating the impact of government energy R&D investments through a multi-attribute utility-based decision tool." Thesis, Massachusetts Institute of Technology, 2011. http://hdl.handle.net/1721.1/67644.
Full textAbstract:
Thesis (S.M. in Engineering and Management)--Massachusetts Institute of Technology, Engineering Systems Division, System Design and Management Program, 2011.Cataloged from PDF version of thesis.
Includes bibliographical references (p. 101-104).
Government agencies characteristically face dynamic policy and investment environments yet frequently rely on ad-hoc decision-making methods in response to complexities inherent in their operating landscape. Additionally, standard decision making methods typically undervalue projects by ignoring difficult to value, non-monetary benefits. This presents a problem for public institutions, such as the Department of Energy (DOE), where goals relating to the environment and national security are difficult to quantify. As a result, it is especially challenging to accurately optimize the use of public funds. The Department of Energy (DOE) is responsible for making significant investment decisions under extreme uncertainty with respect to the nation's public energy portfolio. Recently, leaders internal and external to the government have called for a comprehensive and structured approach to assess the DOE's portfolio of programs and initiatives (PCAST, 2010), (American Energy Innovation Council, 2011). Given the broad spectrum of the DOE's current portfolio, from basic R&D to demonstration and across every major energy technology, evaluating the impacts of its potential investments is complex. Within the Department of Energy's Planning Analysis and Evaluation (PA&E) team, a proposal was made to develop a first-of-a-kind decision tool that would provide rigorous analysis of cost and benefit trade-offs associated with the DOE's investments. The decision tool was designed to couple a state-of-the-art climate and energy model with sophisticated multi-attribute-based decision methods. The research described in this thesis illuminates the advantages and shortcomings of the initial decision tool structure, and presents a second generation model that is tailored to the DOE's operational context. Finally, in order to expand its use for long-range strategy formation, an evolution of this second generation model is explored through the application of recent theoretical methodologies. The resulting decision tool is intended to play an informative role within a comprehensive portfolio review by enabling the enumeration of budgetary trade-offs that address high-level, strategy questions facing the DOE.
by Kacy J. Gerst.
S.M.in Engineering and Management
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Figus, Gioele. "Evaluating the impact of pro-environmental energy policy in Scotland and the UK : the case of increased efficiency in household energy use." Thesis, University of Strathclyde, 2017. http://digitool.lib.strath.ac.uk:80/R/?func=dbin-jump-full&object_id=28661.
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In this thesis, I use multi-sectoral computable general equilibrium techniques to investigate the system wide impacts of improvements in households' energy efficiency use, and technical progress in delivering households' energy services, in Scotland and the UK. The thesis consists of three main, self-contained but correlated essays. The first essay looks the system wide impacts of an illustrative 5% energy efficiency improvement in households' energy use in Scotland and highlights the economic implications of increasing energy efficiency in a regional economy. I find that this results in a small economic stimulus, accompanied by a reduction in energy use that is less than the expected energy savings from the pure energy efficiency increase- the rebound effect. The stimulus is higher when migration of workers is allowed between Scotland and the rest of the UK. However, the higher expansion also delivers a higher rebound in energy use. The stimulus from the higher efficiency in energy use if further enhanced when I consider the impact of greater fiscal autonomy in Scotland, and allow for endogenous government expenditure or tax rates. The second essay analyses the distributional impacts of households' energy efficiency improvements in the UK, focussing the attention on efficiency improvements in lower income households. I discuss whether there is an argument for the Government to fund household energy efficiency programmes via a temporary reallocation of current government expenditure or an increase in the income tax rate. While reallocating public spending has short-term negative impacts on demand over the period of the payment, the efficiency improvement delivers a net long-run stimulus. However, an increase in income tax adversely affects the real take home wage and delivers a long-term reduction in GDP. In all scenarios, lower income households are able to increase their energy consumption and their income by approximately the same amount. The third essay looks at the consumption of energy intensive services using the example of private transport. Here I argue that private transport should be modelled as a household self-produced commodity, composed of refined fuels and motor vehicles. By using a simple partial equilibrium model, I show that technical improvement in motor vehicles can reduce refined fuels use, when there is enough substitutability between the two inputs, and depending on the price elasticity of demand for private transport. By taking the case of the UK, and using a CGE model, I find that technical progress in motor vehicles delivers a small expansionary improvement if the consumer price index is adjusted to account for the implicit price of private transport.
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Maksimcev, Mirko D. "Energy considerations in power system damping by reactorcapacitor switching." Thesis, McGill University, 1995. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=23370.
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Flexible AC transmission systems (FACTS) technology is an emerging new technology which can be efficiently used in power system damping. Objectives of this study are the considerations of the energy flow involved in power system damping by functional switching of series capacitors and/or reactors. The principal questions are how the energy transiently flows through the network and what is its impact on damping of mechanical oscillations.The analytical studies (covered in Chapter 1) reveal that the magnetic and electrostatic energy are constantly stored in the reactive components of the transmission system. The energy stored in a series compensated line is greater than the energy stored in an uncompensated line of equal transmission capability. The transient energy flow caused by characteristic switching in transmission systems is studied analytically in Chapter 2. Switching of an additional line or switching of series capacitors initiates transient charging/discharging of the line towards its new steady-state energy level which is always associated with losses. Power transfer characteristics of the systems which are equivalent in steady-state operation (parallel lines vs. an equivalent series compensated line) have quite different transient power transfer characteristics. These differences are related to different stored energies in such systems. System sources participate in all transient energy flow phenomena.
The impact of series compensation switching upon the mechanical oscillation damping was demonstrated by simulations presented in Chapter 3. Thyristor switched variable series compensation (VSC) is simulated in order to verify the conclusions of the analytical studies regarding the charging/discharging energy of the line.
The switching of reactive power components for the purpose of power system oscillation damping involves significant energy impulses in and out of the machines. Therefore, stability studies have to be performed by simulation which involves detailed representation of electromagnetic phenomena (EMTP for example).
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Wang, Chao. "A model study of the dynamics of dark energy." Thesis, McGill University, 2012. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=106572.
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Observational facts indicate that the expansion of the universe is accelerating, rather than decelerating, because 73% of the total energy density of the universe is a "dark energy" with strong negative pressure, ω < −1/3. In this thesis, we introduce a dynamical dark energy model with dilatational symmetry, which contains two scalar fields coupled to gravity. Because of the dilatational symmetry, there is no cosmological constant Λ in the Lagrangian, and, instead, two scalar fields generate the dark energy, evolving slowly in time. At early times, the system is in the slow roll regime, corresponding to Higgs inflation due to the Higgs field. At late times, the dynamical dark energy dominates the universe and eventually behaves just like the cosmological constant, and the universe becomes exponentially expanding with the scale factor a(t) ∝ exp{Ht}. The numerical results from solving the dynamic equations of the system agree well with the observational facts, which indicates that our model gives a good description of the universe. At the end of the thesis, we consider the one-loop corrections to our model, and show that they do not alter the classical results in any significant way.Les observations actuelles de l'expansion de l'univers indiquent une accéleration decette expansion due à 'l'énergie sombre', qui compte pour 73% de la densité d'énergie totalle de l'univers et qui se comporte comme un fluide avec une pression négative, ω < −1/3. Cette thèse présente un modèle dynamique d'énergie sombre invariant sous une symétrie de dilatation comprenant deux champs scalaires couplés à la gravitation. La constante cosmologique n'est pas présente dans ce modèle, de par la symétrie de dilatation; les champs scalaires génèrent une énergie sombre évoluant dans le temps. Dans l'univers primordial, le système se situe dans le régime d'évolution lente correspondant à l'inflation cosmolgique due au champ de Higgs. L'énergie sombre dynamique agit ultérieurement sur l'évolution de l'univers comme une constante cosmologique; le facteur d'échelle de l'univers accroit de manière exponentielle a(t) ∝ eHt. Les simulations numériques concordent très bien avec les observations actuelles. Les perturbations quantiques de premier ordre sont ensuite calculées, et justifient la validité des résultats obtenus de manière classique.
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Bonsi, Adime. "Fatigue of piezoelectric beams used in vibration energy harvesting." Thesis, McGill University, 2010. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=92374.
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The goal of this thesis is to determine the fatigue life of piezoelectric energy harvesters. The harvester is a cantilever beam made from the piezoelectric ceramic lead zirconate titanate (PZT). Similar structures are used in micro electromechanical systems (MEMS) as actuators and energy harvesters to convert electrical energy to mechanical energy and vice versa. A platform was built to excite PZT cantilever beams in bending vibration, and a method was developed to detect the mechanical and electrical response of the beam, and correlate changes in these responses to the onset of damage.Subsequently, test protocols were developed to experimentally determine the fatigue life of PZT beams by applying total life and damage tolerance approaches to fatigue testing. Total life tests were performed on pristine beams, while damage tolerance tests were performed on beams indented to induce localized damage. Rates of crack growth were measured by interrupting the fatigue tests and imaging the cracks using scanning electron microscopy. The observation of crack arrest is a major result arising from these studies. The test platform developed in this thesis can be used to explore the effects of size on the fatigue reliability of miniaturized energy harvesters.
Le but de ce projet est de déterminer la résistance en fatigue des générateurs d'énergie piézoélectrique. Le générateur est une poutre en porte-à-faux en miniature faite d'une céramique piézoélectrique de titano-zirconate de plomb (PZT). Des structures similaires sont utilisées dans des systèmes micro-électromécaniques (MEMS) tels que les actionneurs et les générateurs d'énergie pour convertir l'énergie électrique en énergie mécanique et vice versa. Un dispositif a été construit pour soumettre des poutres en miniature au cintrage par vibration et une méthodologie a été développée pour détecter la réponse mécanique et électrique des poutres, et corréler les variations de réponses observées au début de leur bris.
Par la suite, un protocole est développé pour déterminer l'endurance des poutres en miniature PZT, en adoptant l'approche de la durée de vie totale des poutres et celle de leur tolérance au bris. Les expériences de la durée de vie totale sont effectuées sur des poutres immaculées, et les autres sont faites sur des poutres cabossées afin d'introduire un défaut local. Les fréquences de la croissance des craquelures sont mesurées à l'arrêt des expériences et capture des images des craquelures à l'aide du microscope à balayage. L'observation de l'arrêt des craquelures est le résultat majeur émanant de ces études. Le dispositif d'expérimentation utilisé peut aussi servir à explorer l'ampleur des effets des générateurs d'énergie sur la fiabilité de la fatigue.
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Singh, Ishaan Bir. "TIEGeR: An energy-efficient multi-parameter geographic routing algorithm." Thesis, McGill University, 2012. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=107861.
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Geographic routing algorithms conventionally use one-hop greedy forwarding as their primary routing technique, which might lead to routing voids. Secondary routing schemes used to circumnavigate such routing voids are unfortunately not efficient in terms of throughput and energy consumption. Moreover, node residual energy and link quality are not considered during the routing process. This thesis presents a Two-hop Information based Energy-efficient Geographic Routing (TIEGeR) scheme to achieve effective energy balancing throughout the network, while preventing routing voids by proactively avoiding "local maxima" nodes. Distance to reach destination, node connectivity, link quality, and node residual energy are employed to formulate the routing metric for the TIEGeR. Besides, secondary routing scheme dealing with routing voids is supplemented by the reverse progress mode. The proposed TIEGeR algorithm is implemented and evaluated in an IEEE 802.15.4 environment using both simulation based on NS-2 and experimental testbed based on TI CC2530ZDK nodes. Simulations are used to investigate the performance of TIEGeR in large-scale network topologies. By experiment, we further evaluate and demonstrate the real-life operation and performance advantages of the TIEGeR scheme implemented in the network layer of a WSN using IEEE 802.15.4 MAC/PHY layers. Simulation and experimental results verify the advantages of TIEGeR against conventional geographic routing schemes.Les algorithmes de routage géographique utilisent conventionnellement des techniques avides de renvois à un bond comme leur technique primaire de routage mais ces techniques peuvent aboutir à une impasse. Les techniques secondaires de routage utilisées pour contourner les impasses ne sont malheureusement pas efficaces en termes de débits ou de consommation d'énergie. De plus, l'énergie résiduelle des nœuds et la qualité des liens ne sont pas considérés durant le procédé de routage. Ce mémoire présente une technique de routage géographique écoénergétique (TIEGeR) à deux bonds et basée sur de l'information pour obtenir un équilibre d'énergie efficace à travers le réseau tout en évitant les impasses en empêchant de manière proactive les nœuds maximaux relatifs. La distance pour atteindre la destination, la connexité des nœuds, la qualité des liens, et l'énergie résiduelle des nœuds sont utilisés pour formuler la mesure de routage pour TIEGeR. Par ailleurs, les techniques secondaires de routage traitant les impasses sont complémentées par le mode de progrès inverse. L'algorithme TIEGeR proposé est implémenté et évalué dans un environnement IEEE 802.15.4 en utilisant des simulations basées sur le NS-2 and en utilisant un banc d'essai basé sur les nœuds TI CC2530ZDK. Les simulations sont utilisées pour examiner la performance de TIEGeR dans une topologie de réseaux à grande échelle. Avec le banc d'essais, nous examinons et nous démontrons le fonctionnement et la performance réalisable de la technique TIEGeR quand elle est implémentée dans la couche réseau d'un réseau de capteurs sans-fil qui utilise la couche physique et la couche de contrôle d'accès au support (MAC) du IEEE 802.15.4. Les résultats des simulations et du banc d'essai vérifient les avantages du TIEGeR contre les techniques conventionnelles de routage géographique.
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Pulfrey, Simon M. "Energy expenditure and requirement while climbing at extreme altitude." Thesis, McGill University, 1995. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=23288.
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Humans can only survive the low barometric pressure of altitudes above 6000m by making a complex series of adaptations. The energetics of human survival at such extreme altitudes have not been widely studied. Objectives were to compare the doubly labelled water (DLW) and intake-balance (IB) methods to estimate daily energy expenditure while climbing between 6000 and 8046m and to investigate the putative metabolic cost involved with the process of acclimatization to extreme altitude. Reliability of the DLW method to provide an accurate and portable means to measure human energy expenditure depends upon a series of assumptions regarding the flux of tracer and tracee across the physiological compartments of measurement. Additional objectives were to review and examine the proficiency of these assumptions to account for perturbations experienced while using DLW while climbing at extreme altitude. Findings suggest that the use of DLW at extreme altitudes requires special consideration towards elevated rates of fractional isotope loss, inter-subject isotope transfer, alterations in total body water, changes in background isotopic abundance, and choice of sampling technique. Revised strategies directed at achieving these aims are calculated. Results from extreme altitude indicate that IB and DLW techniques each provide similar estimates of group mean energy expenditure despite substantial changes in body weight and composition and that the metabolic cost for the process of acclimatization accounts for roughly 12% of total daily energy expenditure. Problems associated with maintaining energy balance while climbing at extreme altitude are related to low energy intakes, approximately only 70% of energy demands, and energy expenditure values that are comparable to those of highly trained endurance athletes at sea-level.
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Biot-Pelletier, Damien. "Structural biology of energy-transducting proteins from «Escherichia coli»." Thesis, McGill University, 2010. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=95207.
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The cell envelope of Gram-negative bacteria such as Escherichia coli is composed of an outer (OM) and cytoplasmic membrane (CM), which enclose a space known as the periplasm. For acquisition of essential nutrients, bacteria must transport molecules across both membranes. The import of certain scarce nutrients, such as iron and vitamin B12, requires the input of energy; however, the OM is devoid of any source of energy. To drive the transport of scarce nutrients across the OM, bacteria use the proton motive force of the CM. The TonBExbBExbD protein complex located within the CM is responsible for harnessing the energy of this proton gradient and transducing it to OM receptors. While the existence and the role of this complex has been investigated many years ago by genetic means and by in vivo crosslinking experiments, structural and functional aspects remain largely unknown. To date, only partial structures of periplasmic domains of TonB and ExbD are known. Additionally, information on the structure of the complex as well as stoichiometry has not been deduced. We have therefore designed a strategy for the co-expression and co-purification of ExbB and ExbD in complex. Here we produced milligram amounts of pure ExbBExbD; size-exclusion chromatography revealed that our samples were homogenous and monodisperse. Observation of our samples by negative-staining electron microscopy revealed uniform particles from which 2D reconstructions were generated. These reconstructions suggested a pentameric and perhaps cylindrical arrangement for the complex. In parallel, crystallization trials have identified promising leads. Our optimization efforts have led to the successful detergent exchange of the protein complex from dodecyl maltoside to decyl maltoside, to GNG-12 and to MNG-28; the latter two amphiphiles are proprietary and of undisclosed structure. We also adopted an NMR detergent quantitation method to standardize amounts of detergent in samples bound for crystallizL'enveloppe cellulaire des bactéries à Gram négatif tel Escherichia coli est constituée d'une membrane externe (ME) et d'une membrane cytoplasmique (MC), entre lesquelles se trouve un espace nommé périplasme. L'acquisition de nutriments essentiels par les bactéries nécessite le transport de molécules à travers chacune des deux membranes. Le transport de certains nutriments rares, tel le fer et la vitamine B12, requiert un apport en énergie. Cependant, la ME est dénuée de toute source d'énergie. Ainsi, pour alimenter en énergie le transport de nutriments rares à la ME, les bactéries font appel à la force proton motrice de la MC. Le complexe protéique TonBExbBExbD, situé à la MC, arnache l'énergie de ce gradient de protons et la transduit aux récepteurs de la ME. Bien que l'existence et le rôle de ce complexe aient été sondés il y a plusieurs années par des voies génétiques et des expériences de réticulation in vivo, plusieurs aspects de la structure et de la fonction du complexe restent inconnus. Jusqu'à maintenant, seule la structure des domaines périplasmiques de TonB et ExbD sont connus. Qui plus est, le structure du complexe et sa stoechiometrie n'ont pas été résolus. Nous avons donc élaborée une stratégie pour la co-expression et la co-purification d'ExbB et d'ExbD en complexe. Nous produisons plusieurs milligrammes d'ExbBExbD pur et la chromatographie par filtration sur gel révèle que nos échantillons sont homogènes et monodispersés. L'observation de nos échantillons par microscopie électronique en coloration négative révèle des particules de taille uniformes à partir desquelles des reconstructions 2D ont été générées. Ces reconstructions semblent suggérer un arrangement pentamérique et peut-être cylindrique. En outre, nos essais de cristallisation nous ont permis d'identifier des pistes prometteuses. Nos efforts d'optimisation nous ont amenés à échanger avec succès notre protéine depuis l