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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

An assessment of value for deep sedimentary geothermal resources in Texas

Uddenberg, Matthew Emmanuel 20 July 2012 (has links)
Building upon work completed by the Bureau of Economic Geology (BEG) for the National Geothermal Data System (NGDS) this thesis develops a coherent strategy for assessing the value of geothermal resources for different regions within Texas. Valuing geothermal resources is difficult because energy output from a specified resource is predicated on the development strategy employed and the dynamic qualities of the reservoir being analyzed. To account for these factors a lumped parameter model is developed to provide a flexible means for assessing the value of different resources. The model is designed to quickly adapt to different reservoir geometries, provided by the NGDS, and account for the dynamic nature of geothermal resources, which will vary as a function of the development strategy employed. In this paper two development strategies for a field located in Hidalgo County have been modeled to illustrate the use of the model and explain how its structure allows for realistic and nuanced analysis. The two scenarios modeled have a sustainable outcome, where the geothermal resource produces a continual low amount of power, and an unsustainable outcome, where power generation is initially high but terminates before the expected life of the project. The outcomes from these two scenarios clearly illustrate the usefulness of using a lumped parameter model to assess the value of a geothermal resource with regards to a set of defined objectives. / text
2

Impacts of tidal currents on the assessment of the wave energy resource of the west coast of Canada

Beya, Ignacio 27 August 2020 (has links)
Numerous studies have identified the west coast of Canada as an attractive place for the development of wave energy projects. To evaluate the viability of these projects, an accurate description of the wave resource is crucial. Most of the previous efforts to characterize the wave climate in B.C. at shallower waters, where wave energy converters (WECs) are most likely to be deployed, lack the necessary nearshore spatial resolution, and were driven by overly simplistic wave boundary conditions. In addition, none of the previous studies have included the effect of tidal currents, which have been proven to be significant in wave resource characterizations in other locations. This work increased the fidelity of the wave resource characterization and developed an understanding of the impact of tidal currents on the wave conditions in this region by generating two most accurate, long-term (14 years, 2004 to 2017), high resolution (in space and time) datasets of the wave resource for the west coast of Canada. The two datasets were generated using nearly identical SWAN wave models, which their only difference was that one of them (V5), did not incorporate the effect of currents, while the other (V6) included tidal currents as forcing. Thus, the pure influence of the tidal currents on the wave characteristics was able to be identified when comparing the two wave model results. This study developed simple, robust, and objective metrics to support the calibration process and to evaluate the performance of the models. Utilizing these metrics, the V5 and V6 models presented substantial improvements in reproducing the wave conditions of about 18% and 20%, respectively and in relation to the previous most complete and accurate wave model of the region (V4). Their better performance was largely achieved by a significant increment in their ability to reproduce the significant wave height (H_m0) and energy period (T_e). The inclusion of tidal currents in the wave model increased the accuracy of the wave resource characterization, mainly by improving the model’s ability in simulating T_e by 5.1%. The most sensitive wave parameter to the tidal currents was the peakedness of the wave spectrum (Q_p), which was consistently and significantly reduced by values even larger than 2.5. In some regions, directions characterized by the mean wave direction (D_m) and the directional spreading (D_spr) were also noticeably very sensitive to the currents, which even deflected D_m to its opposite direction and drove changes in D_spr that reached values of up to 40°. However, these significant transformations were less frequent and reduced in magnitude at exposed (to swell-waves) sites, where strong currents have affected waves in a reduced part of their trajectory. Typically, tidal currents had the effect of reducing the wave power density (P), but in a relatively small amount, however, during rare events, tidal currents were able to induce changes in this parameter ranging -140 kW/m to 75 kW/m. At these extreme events, it was observed that the peak of the wave spectra became flatter, with some of its wave height variance redistributed to near increasing and decreasing frequencies and directions, regardless to the magnitude and direction of the local tidal currents. Impacts of the tidal currents on P were largely attributed to the induced changes in H_m0 and T_e. Although D_spr and Q_p were greatly transformed by the action the tidal currents, they account very little in explaining the variations in P. These four wave parameters together, and how they are transformed under the presence of currents, can explain a large part of the changes in P, however, other transformations of the wave spectrum due to the currents, not investigated in this study, must account for a considerable part of the changes in P. / Graduate
3

Cumulative energy assessment of Ligna Energy organic battery : From its extraction to its end-of-life thermal conversion

Thorén, Linda January 2021 (has links)
With an increasing share of intermittent electricity production in the energy system, there is an increased need for energy storage. Because of electrochemical batteries’ ability of modularization, fast response and flexibility, grid connected energy storage will enable load balance and dispatching stored energy to optimize grid operations. Grid operation applications such as frequency regulations, peak- and time-shifting will enable saving otherwise curtailed renewable energy. The extraction of materials and the manufacturing of batteries are though energy intense processes themselves. Ligna Energy develops an organic battery, based on organic electronic polymers and biopolymers from the forest. These organic batteries are less energy dense, but do not contain conflicts material, require any strict, energy consuming production environment and can be burned as biofuels in the end of life. Standardize methods for life cycle assessment is a useful tool to determine the cumulative energy demand from extraction of material to end of life thermal conversion. Operation applications such as increase of self-consumption, energy time shift and frequency regulation show that the Ligna Energy organic battery deliver more energy to the grid through the specific operation, than demanded for manufacturing after 15, 9 respectively 1 year.
4

Avaliação nutricional de farinhas de vísceras de aves e a utilização em rações de frangos de corte / Nutritional evaluation of poultry offal meal and the use in dietsof broilers

SILVA, Edney Pereira da 19 February 2009 (has links)
Submitted by (edna.saturno@ufrpe.br) on 2017-04-10T12:40:00Z No. of bitstreams: 1 Edney Pereira da Silva.pdf: 591777 bytes, checksum: 00f50d975a2067959b8b9e75561e960b (MD5) / Made available in DSpace on 2017-04-10T12:40:00Z (GMT). No. of bitstreams: 1 Edney Pereira da Silva.pdf: 591777 bytes, checksum: 00f50d975a2067959b8b9e75561e960b (MD5) Previous issue date: 2009-02-19 / Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / The experiments were conducted with the purpose of determining the values of energy and nutritional of poultry offal meal (POM) for broiler chickens. Initially was analyzed the composition of three POM and two trials were conducted, one for determining the rate of passage and another to determine the apparent and true metabolizable energy corrected (AMEn and TMEn). The POMs had an average of: 93.34% dry matter, 62.73% for crude protein (CP), 15.42% ether extract (EE), 5200 kcal / kg gross energy (GE) and 10 , 18, 2.61, 1.37, 0.47, 0.59 and 0.78% for mineral matter (MM), calcium (Ca), phosphorus (P), sodium (Na), chlorine (Cl) and potassium (K), respectively. The density was about 457.64 g/L and geometric mean diameter of 639.09 μm. The rate of passage of FVA is correlated (r = -99.86%) with the level of EE. Flour showed values of: 3996, 3770 and 4167 kcal / kg for AMEn and 4016, 3794 and 4187 kcal/kg for TMEn for the POM A, B and C, respectively. Another search was conducted and consisted of a bibliography revision, considering only the works published on FVA developed in Brazil, to generate models to predict the values of AMEn and TMEn. Equations were developed for POMs with medium EE content (AMEn = -2315.69 +31.4439(PB)+29.7697(MM)+0.7689(EB)-49.3611(Ca), R ² = 0,72), with high levels of EE (AMEn = +3245.07+46.8428(EE), R² = 0.76) and high levels of MM (AMEn = 4059,15-440397(P), R² = 0,82). To estimate the values TMEn, two equations were obtained: one for high levels of MM (TMEn = 5092,57-115647 (MM), R ² = 0.78) and another for low (TMEn = 3617,83-15,7988(PB)-18.2323(EE)-96.3884(MM) +0.4874 (EB), R² = 0.76). A final experiment was conducted to determine the effects of inclusion of FVA in the diets of broiler chickens on performance and carcass characteristics. Weight gain, feed conversion, carcass yield and weights showed quadratic response. The abdominal fat increased linearly. The performance of livestock and poultry carcass yield and weights were maximized with the inclusion of 5.3% and 6.5% of poultry offal meal in the diet, respectively. / Os experimentos foram realizados com os objetivos de determinar os valores energéticos e nutricionais de farinhas de vísceras de aves (FVA) para frangos de corte.Inicialmente, analisou-se a composição de três FVAs e dois ensaios foram realizados; um para determinar a taxa de passagem e outro para determinar a energia metabolizável aparente e verdadeira corrigida (EMAn e EMVn). As FVAs apresentaram uma média de: 93,34% de matéria seca, 62,73% para proteína bruta (PB), 15,42% de extrato etéreo (EE), 5.200 kcal/kg de energia bruta (EB), e 10,18; 2,61; 1,37; 0,47; 0,59 e 0,78% para matéria mineral (MM), cálcio (Ca), fósforo (P), sódio (Na), cloro (Cl) e potássio (K), respectivamente. A densidade foi cerca de 457,64 g/L e o diâmetro geométrico médio de 639,09 μm. A Taxa de passagem da FVA se correlacionou-se (r = -99,86%) com o teor de EE. As farinhas apresentaram valores de: 3.996; 3.770 e 4.167 kcal/kg de EMAn e 4.016; 3.794 e 4.187 kcal/kg para EMVn, para as FVA A, B e C, respectivamente. Outra pesquisa foi realizada e consistiu em um levantamento bibliográfico, considerando apenas os trabalhos publicados sobre FVA desenvolvidos no Brasil, para gerar modelos de predição dos valores de EMAn e EMVn. Equações foram elaboradas para FVAs com teor médio de EE (EMAn = -2315,69+31,4439(PB)+29,7697(MM)+0,7689(EB)-49,3611(Ca), R² = 0,72), com altos teores de EE (EMAn = +3245,07+ 46,8428(EE), R² = 0,76) e altos teores de MM (EMAn = 4059,15-440,397(P), R² = 0,82). Para estimar os valores EMVn, duas equações foram obtidas: uma para alto teor de MM (EMVn = 5092,57-115,647(MM),R² = 0,78) e outra para baixo teor (EMVn = 3617,83-15,7988(PB)-18,2323(EE)- 96,3884(MM)+0,4874(EB), R² = 0,76). Um último experimento foi realizado para verificar os efeitos da inclusão da FVA nas dietas de frangos de corte sobre o desempenho e características de carcaça. O ganho de peso, conversão alimentar, rendimento de carcaça e cortes nobres mostraram resposta quadrática. A gordura abdominal aumentou linearmente. O desempenho zootécnico das aves e o rendimento de carcaça e cortes nobres foram maximizados com a inclusão de 5,3% e 6,5% da farinha de vísceras de aves na dieta, respectivamente.
5

Energetická náročnost administrativní budovy / Energy Performance of the Administrative Building

Příborský, Tomáš January 2015 (has links)
First part of this thesis describes possibilities of energy assessment of buildings, possibilities of using thermal imaging camera in civil engineering and using software solutions of energy assessment of buildings. Second part engages an energy assessment of administrative building of NEPA company in Brno and designes possibilities of improvements. Third part contains description of technical solution of the best improvement possibility.
6

Analysis of AEP prediction against production data of commercial wind turbines in Sweden

Sugathan, Aromal, Gregory, Sean January 2021 (has links)
Based on data from 2083 wind turbines installed in Sweden since 1988, the annual energy production (AEP) predictions considered at the project planning phases of the wind turbines in Sweden have been compared to the wind-index-corrected production data. The production data and the predicted AEP data are taken from Vindstat, a database that collects information directly from wind turbine owners in Sweden. The mean error for all analyzed wind turbines was 11.9%,which means that, overall, the predicted AEP has been overestimated. There has been improved accuracy with time and error in prediction decreasing from 12% to 6.3% for wind turbines installed in the 2000s and 2010s, respectively. However, the overall improvement in accuracy seems to have stagnated around 2005 despite the refinement of forecasting methods and better data availability. From the results analyzed for effects of terrain, the error is smaller for wind turbines in forest areas than in open terrain, indicating that the complexity of forest terrain is not the reason behind the error. Also, there is no apparent increase of error with wind farm size, which could have been expected if the wind farm blockage effect was a primary reason for the overestimations. Comparison between significant wind turbine manufacturers Vestas and Enercon in the Swedish context, the error was more prominent for Enercon.
7

Modeling frameworks to evaluate energy autarky of wastewater treatment systems

Sarpong, Gideon 01 May 2020 (has links)
This research demonstrates the use of two novel methodologies to evaluate energy autarky status of wastewater treatment plants (WWTPs) in two steps. Step I (analysis 1 and 2) focuses on overall energy performance evaluation of a conventional activated sludge process (CAS) using a quantitative mass balance model. Step II involves development of a dynamic model that simulates a future wastewater resource recovery facility (WRRF). The step I (analysis 1) focused on small WWTPs with treatment capacities less than 5 MGD. The results revealed that a CAS process can achieve energy autarky or energy-positive status when old technology equipment is replaced with new, high efficiency equipment to save 10-12% energy; aeration energy is reduced by installing nitritation/anammox nitrogen removal process; and energy production is enhanced with the addition of FOG for co-digestion. Analysis 2 of step I focusing on large plant capacities (i.e., > 20 MGD) evaluated the effect of influent wastewater strength (IWWS), primary treatment COD removal efficiency (PT-COD), and proper design of combined heat and power (CHP) systems on the overall energy performance. The results showed that energy autarky is feasible when PT-COD is 60% for low IWWS, 40% or greater for medium IWWS, and 30% or greater for high IWWS. In step II analysis, a new and dynamic model was developed by integrating high rate algal pond (HRAP) and anaerobic digester (AD) systems. The model was calibrated using the experimental data from recent studies. The results showed that this system can achieve energy autarky when advanced solids separation and co-digestion systems are included. Solids separation efficiency was increased from 75 to 90% to reduce the winter effluent COD concentrations from HRAP (by 20%). Similarly, nitrogen effluent concentrations were reduced by increasing the solids retention time. Future studies should focus on techno-economic and environmental life cycle impact analysis of these novel process configurations.
8

Energetický posudek solární soustavy / Energy Assessment of Solar System

Šmardová, Eva January 2018 (has links)
The first part of diploma thesis describes how to measure the parameters of solar thermal collector and solar thermal system. The computational part analyzes heat consumption in the evaluated building and describes design of the solar thermal system for domestic hot water. Last part focuses on the energy assessment of the designed solar system above and evaluation of the solar system, which is located at the Faculty of Civil Engineering in BUT.
9

Energy Assessment at a Health Care Facility

Roth, Nicholas Daniel January 2010 (has links)
No description available.
10

Exploitation et réhabilitation de bâtiments tertiaires : une démarche énergétique d'amélioration environnementale

Valderrama Ulloa, Claudia 13 November 2013 (has links)
Le secteur du bâtiment est l’un secteur des plus énergivore, sa consommation énergétique importante découle d’une part de la dégradation des matériaux propre à leur vieillissement et d’autre part, au manque d’un cadre réglementaire énergétique plus strict accompagnant la conception. Enfin cette consommation énergétique est due à la présence des usagers. Ceci est d’autant plus vrai pour le secteur tertiaire au travers leurs activités, leurs comportements et leur degré d’appartenance que les usagers donnent à ces types de bâtiments. En effet, même si tout le monde les utilise, personne ne se sent responsable de leur maintenance. Le travail présenté ici met en avant la relation entre la consommation énergétique dans les campus universitaires et le comportement des usagers. Les résultats sont analysés dans un contexte climatique comparable (paramètre clé les Degrés Jours Unifiés - DJU), avec indicateurs d’évaluation partageables (ce qui ont été judicieusement choisis à partir d’une comparaison entre différents systèmes d’évaluation) et traduit dans une méthodologie d’évaluation (basée sur les méthodes multicritères). Celle-ci tient compte de la multiplicité d’usages, d’usagers et d’attentes énergétiques, environnementales et de confort présents dans ce type de secteur tertiaire. L’objectif principal de cette étude a été d’élaborer une démarche d’amélioration environnementale et énergétique pour l’exploitation des bâtiments tertiaires, pour aller vers la réhabilitation thermique et énergétique, en considérant d’une part, la satisfaction des usagers et d’autre part les performances énergétiques et environnementales améliorées des bâtiments analysés. Ce mémoire de thèse est construit autour la logique suivante : une mise en situation des problématiques énergétiques internationales et nationales (France et du Chili). Un focus sur l’énergie dans le secteur tertiaire, permet de s’imprégner des différents dispositifs mis en place pour atteindre l’objectif de réduction de la consommation d’énergie et des émissions de CO2. Une grille de comparaison qui va nous permettre de réaliser les analyses de consommations énergétiques à différentes périodes de l’année avec un seul paramètre climatologique le DJU, est mise en avant. Ensuite les différents campus et sites universitaires sur lesquels nous appuyons la réflexion sont présentés. Dans ceux-ci, nous analysons à différentes échelles spatio-temporelles et avec différents types d’analyses qualitatives et quantitatives, les variables discriminantes qui seront essentielles pour parvenir à une amélioration énergétique au fil du temps. Par la suite, une ligne de base de critères et indicateurs qui vont nous permettre d’évaluer avec la même échelle d’évaluation, la performance énergétique et environnementale des bâtiments dans leur état actuel est crée. Pour, ensuite, les comparer dans un état optimisé lorsque les améliorations énergétiques ont été mises en place. Enfin nous proposons une méthodologie d’évaluation et d’amélioration environnementale pour l’exploitation des bâtiments tertiaires qui va mettre en relation de façon originale les besoins énergétiques, environnementaux, économiques et de confort des gestionnaires et des usagers universitaires. Une modélisation thermique de solutions de réhabilitation et un modèle économique, assez simple, sont proposés pour illustrer l’application de la méthodologie. / The buildings sector is one of the largest energy consuming sectors, its high energy consumption stems to construction materials degradation on the one hand and to the lack of a stricter regulatory context in design step on the other hand. Finally, this energy consumption is due to the presence of users. This is especially true for the service sector through its activities, its behavior and the sense of belonging of users to this type of buildings. Even if everyone uses them, nobody feels responsible for their maintenance.The work presented here highlights the relationship between energy consumption in university campuses and user’s behavior. The results are analyzed in a comparable climatic context (the key parameter Unified Degree Days - UDD) with sharable assessment indicators (which have been carefully selected from a comparison between different assessment systems). Then, the results are translated into an evaluation methodology (based on multicriterio analysis). The methodology takes into account the multiplicity of uses, users and energy resources, environment and comfort requirements expected in this service sector.This study aims to develop an environmental and energy improvement approach for the operation of tertiary buildings, to move towards a thermal and energy rehabilitation, considering on the one hand, user satisfaction and on the other hand the energy and environmental improved performance of the studied buildings.This manuscript of thesis is built around the following logic: an overview of national and international energy issues (France and Chile). A specific reference to energy in the tertiary sector emphasizes the different mechanisms put in place to achieve the reduction target of energy consumption and CO2 emissions. A comparison grid is built to analyze energy consumptions at different times of the year with a single climate parameter: the DDU (Unified Degree Days). Then, the different campuses and universities supported by the reflection are presented. In these study cases, we analyzed at different spatio-temporal scales and with different types of qualitative and quantitative analysis, the discrimination of critical variables to achieve energy improvements over time. Subsequently, a baseline of criteria and indicators is developed to evaluate the energy and environmental performance of buildings in their current state with the same rating scale. Then energy improvements are implemented to compare them in an optimized state. Finally, we propose an evaluation methodology and environmental improvements for the operation of tertiary buildings which will bring together in an original way the energy, environmental, economic and comfort managers and users universities needs. Thermal modeling solutions and economic rehabilitation rather simple model are provided to illustrate the application of the methodology. / El sector de la construcción es uno de los sectores que más energía consume, este consumo se debe en parte a la degradación de sus materiales, propia al paso del tiempo, a la falta de un marco legal energético más estricto que regule su diseño-concepción y por otra a la presencia de sus usuarios. Este fenómeno se vuelve más recurrente en el sector terciario debido a sus actividades, sus comportamientos y el grado de pertenencia que los usuarios le dan a este tipo de edificios. De hecho, si es cierto que todo el mundo los puede utilizar, no todos se sienten responsables de su cuidado.El trabajo que aquí se ha desarrollado presenta la relación entre el consumo energético de los campus universitarios y el comportamiento de sus usuarios. Los resultados se han analizado bajo un contexto climático comparable (parámetro clave los Grados Días Unificados - GDU), indicadores de evaluación adaptables (que han sido cuidadosamente seleccionados a partir de una comparación entre distintos sistemas de evaluación - certificaciones) y que se han traducido a través de una metodología de evaluación (basada en métodos de multicriterio). Esta metodología considera la multiplicidad de usos, de usuarios y de requerimientos energéticos, medioambientales y de confort presentes en este tipo de sector terciario.El objetivo principal de este estudio ha sido desarrollar una metodología de mejora energética y medioambiental para la operación de edificios terciarios, que permitirá además de considerar una rehabilitación térmica y energética, teniendo en cuenta, por una parte, la satisfacción de los usuarios y por otra el desempeño energético y medioambiental mejorado de los edificios analizados.La memoria de la tesis ha sido construida bajo la siguiente lógica: la presentación de las problemáticas energéticas internacionales y nacionales (de Francia y de Chile). Una visión de la energía en el sector terciario, permite ahondar sobre los diferentes mecanismos establecidos para lograr el objetivo de reducir el consumo energético y las emisiones de CO2. Un sistema de comparación nos permite analizar el consumo energético en diferentes periodos del año, a través de un único parámetro climático, el GDU. A continuación se presentan los diferentes campus y sitios universitarios en los que nos apoyamos para el análisis. En ellos, analizamos a diferentes escalas espacio-temporales y con diferentes tipos de análisis cualitativos y cuantitativos, las variables discriminantes que serán fundamentales para lograr la mejora de la eficiencia energética a través del tiempo. Posteriormente, construimos una línea de base de criterios e indicadores que nos permitirá evaluar a través de una misma escala de evaluación, el desempeño energético y medioambiental de los edificios en su estado actual, para luego compararlos en un estado óptimo cuando diferentes mejoras energéticas se han implementado. Por último, proponemos una metodología de evaluación y de mejoras energéticas para la operación de edificios terciarios, dicha metodología relaciona de manera original las necesidades energéticas, medioambientales, económicas y de confort de gestores y de usuarios universitarios. Finalmente, proponemos para ilustrar la aplicación de la metodología, un modelo térmico de soluciones de rehabilitación y un modelo económico simplificados.

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