In this thesis, studies associated with the stability analyses of the box-shaped dump-site culvert constructed in Tinaz Surface Mine of Turkish Coal Enterprises (TKi) are presented. In addition, stability conditions of other culvert alternatives are evaluated. Existence of creeks in a surface mining area is a significant factor to be considered in selection of dump-site location. Since, the dumped overburden material on the valley acts as a barrier and behaves like a dam causing flood problem behind the dump-site. TKi engineers prevented the flood potential that might have occurred behind the dump-site by constructing a 480-meter long reinforced-concrete culvert on the downstream of Gevenez Creek Valley. However, considerable amount of deformations occurred in the first 100 meters of the culvert, as a result of overburden material being replaced on this structure. In order to determine the failure mechanism associated with the culvert, a series of numerical modeling analyses were carried out utilizing back analysis technique. The validity of the numerical model was justified by convergence measurements and observations carried out inside the culvert as overburden material being replaced on the stable part of this structure. Finally, based on the numerical model developed, the stability of other culvert alternatives that could be used in future projects were evaluated considering different embankment conditions (positive projecting and negative projecting), bedding conditions (impermissible, ordinary, first-class and concrete cradle), culvert shapes (box and circular) and dumping conditions.

Solar energy is one of the most promising renewable resources that can be used to produce electric energy through photovoltaic process. A significant advantage of photovoltaic (PV) systems is the use of the abundant and free energy from the sun. However, these systems still face major obstacles that hinder their widespread use due to their high cost and low efficiency when compared with other renewable technologies. Moreover, the intermittent nature of the output power of PV systems reduces their reliability in providing continuous power to customers. In addition, the fluctuations in the output power due to variations in irradiance might lead to undesirable performance of the electric network. The support of governments, electric utilities, researchers and consumers is the key to overcoming the aforementioned obstacles and enhancing the maturity of the technology in this field. The primary objective of the research proposed in this thesis is to facilitate increasing the penetration levels of PV systems in the electric network. This can be achieved by quantifying and analyzing the impacts of installing large grid-connected photovoltaic systems on the performance of the electric network accurately. To achieve this objective, the development of a new and intelligent method is introduced. The method utilizes the available data efficiently to produce accurate realistic results about the performance of the electric network without overestimating or underestimating the impacts of the PV system. The method utilizes historical environmental data collected over a number of years to estimate the profile of the output power of the PV system. In addition, the method considers the actual data of the electric network. Hence, the interaction between the output power of the PV system and the electric network components can be simulated to identify the possible operational problems. After identifying the operational problems that might arise due to installing PV systems, especially due to power fluctuations, different strategies that can mitigate these problems are studied in detail. These strategies include installation of energy storage devices, use of dump loads, and operation below the maximum power point. Upon studying the mitigation strategies, their economical aspects are investigated. The economical aspect is crucial for PV systems because of their high cost, which is reflected on the price of the energy produced by them. The presented research integrates techniques from different fields of engineering such as data mining, mathematical optimization and power systems. This research is expected to contribute to the advancement of PV technology by introducing methods that will help in carrying out in-depth evaluation of the performance of PV systems and providing feasible solutions to the operational problems that might arise from the installation of these systems.

Solar energy is one of the most promising renewable resources that can be used to produce electric energy through photovoltaic process. A significant advantage of photovoltaic (PV) systems is the use of the abundant and free energy from the sun. However, these systems still face major obstacles that hinder their widespread use due to their high cost and low efficiency when compared with other renewable technologies. Moreover, the intermittent nature of the output power of PV systems reduces their reliability in providing continuous power to customers. In addition, the fluctuations in the output power due to variations in irradiance might lead to undesirable performance of the electric network. The support of governments, electric utilities, researchers and consumers is the key to overcoming the aforementioned obstacles and enhancing the maturity of the technology in this field. The primary objective of the research proposed in this thesis is to facilitate increasing the penetration levels of PV systems in the electric network. This can be achieved by quantifying and analyzing the impacts of installing large grid-connected photovoltaic systems on the performance of the electric network accurately. To achieve this objective, the development of a new and intelligent method is introduced. The method utilizes the available data efficiently to produce accurate realistic results about the performance of the electric network without overestimating or underestimating the impacts of the PV system. The method utilizes historical environmental data collected over a number of years to estimate the profile of the output power of the PV system. In addition, the method considers the actual data of the electric network. Hence, the interaction between the output power of the PV system and the electric network components can be simulated to identify the possible operational problems. After identifying the operational problems that might arise due to installing PV systems, especially due to power fluctuations, different strategies that can mitigate these problems are studied in detail. These strategies include installation of energy storage devices, use of dump loads, and operation below the maximum power point. Upon studying the mitigation strategies, their economical aspects are investigated. The economical aspect is crucial for PV systems because of their high cost, which is reflected on the price of the energy produced by them. The presented research integrates techniques from different fields of engineering such as data mining, mathematical optimization and power systems. This research is expected to contribute to the advancement of PV technology by introducing methods that will help in carrying out in-depth evaluation of the performance of PV systems and providing feasible solutions to the operational problems that might arise from the installation of these systems.

Switched Reluctance Machine (SRMs) are receiving significant attention for industries and homes in the last decade. Due to their rugged brushless design, high reliable and an outstanding performance over a wide speed range. The stator and rotor of an SRM have a double salient pole and the rotor has no windings and magnets, its torque generating is quite nonlinear and has high torque ripple. Therefore, sophisticated switching and control technologies are needed to improve its driving performance. The cost and performance of SRM drives are highly dependent on the converter topologies and motor structure, so that developments in the convert topologies have been made in parallel with motor design. The objective of this thesis is proposed three phase Switched Reluctance Machine using a fly back resistor C Dump Converter to replace the tradition Bridge Converter. It can reduce switching losses, to reduce converter production cost with a simpler circuit. At the end, a digital signal processor based control system is used to test the laboratory make drives .

Beam dumps are installed at the experimental areas of the ELBE facility. Their purpose is to absorb the primary electron beam and the secondary radiation. The beam dump consists of a purified graphite core inside a water cooled stainless steel vessel. The radiation shield surrounding the beam dump will be designed individually for each experimental area. In this context, dose rate calculations were carried out to estimate the dose rate source term around the stainless steel vessel of the beam dump. Detailed Monte Carlo simulations were carried out using the code FLUKA. The energy dependent photon and neutron fluences and the equivalent dose rates were obtained near the surface of the cylindrical steel vessel for a beam current of 1 mA and energies of 20 MeV and 50 MeV.

In 1990 Flödeskommittén released new guidelines which redefined the method used to determine design flows. The method, combined with more complete measurements of flow variations, has resulted in higher design flows which in turn call for increases in the discharge capacity of hydropower plants. This work is still in progress. Since many Swedish hydropower stations were constructed in the 1950's and 60's they require modernization. Today Statkraft owns and operates 55 hydropower stations in Sweden several of which have a discharge capacity below the design flow. For this reason, the dam safety of these hydropower stations is reduced. According to current guidelines the turbine flow is not added to the discharge capacity since the availability of the electrical grid is not guaranteed during extreme flows. When the electric grid is unavailable the generator has no load and cannot produce an electric torque. Without the electric torque the turbine accelerates which may result in equipment failure. This thesis considers the introduction of an alternative local load where the generator power can be dumped as heat, hence termed dump load. The dump load has the potential to increase the discharge capacity by adding the turbine flow. However, operation of the dump load requires the availability of the generator and turbine, making the discharge capacity dependent on the status of the plant. In turn, achieving a sufficient discharge capacity is of primary concern to dam operators since it determines dam safety. Consequently, this thesis evaluates the effects on dam safety when utilizing a local load to increase the discharge capacity. Three different designs were evaluated; a medium to high voltage electrode water boiler, electrodes submerged in the river and a low voltage electric water boiler. The evaluation shows that all three designs are feasible and can be used to increase the discharge capacity provided the generator and turbine have high availability. The complexity and number of components constituting the dump load should be minimized to reduce the risk of malfunctions and redundancy should be introduced for key components when feasible. The dump load power should be controlled using voltage regulation but further work is required to determine the specifics of this governor. The results also show that the cost of the dump load is a fraction of the cost of a new spillway. However, the topic is controversial and the dump load requires practical testing in order to evaluate operational reliability.

<p>Coal provides for 77% of South Africa&rsquo / s primary energy needs and is therefore a major resource that supports the socio-economic needs of South African citizens. Power stations are the major consumers of coal in South Africa and produces electricity from burned coal. The burning of coal produces a large volume of ash that is disposed in the form of ash dump systems. The ash&nbsp / dump system is treated with high salinity process water from the power station for dust suppression. The process water contains salts due to evaporation processes from the recirculation&nbsp / &nbsp / of&nbsp / water in the cooling water system. Various studies to evaluate the sustainability of the ash dump system as a sustainable salt sink were therefore conducted. This study aimed to develop a conceptual model for the ash dump system by evaluating the movement of the process water trough the ash dump and the impacts it might have on the underlying weathered dolerite aquifer. This was achieved by evaluating the hydraulic and transport properties of the ash dump system. An initial site conceptual model was first established prior to the application of the hydraulic&nbsp / and transport methods. The initial conceptual model was based on the literature, previous reports and an initial site walk over. Known and tested hydraulic and transport methods were applied&nbsp / n bo.th field and laboratory scale for the saturated part of the ash dump system. The laboratory experiments comprised of column and core experiments. These methods assisted in&nbsp / parameter estimation of hydraulic and transport properties and also assisted in the planning of the field experiments. The field experiments were conducted in the form of slug tests, tracer&nbsp / dilution and natural gradient divergent tracer test experiments. The combined laboratory and field experiments provided statistically significant values that were then used as inputs into the&nbsp / conceptual model. Field experiments were also applied to a surrogate aquifer that represented the underlying shallow weathered dolerite aquifer of the ash dump system. The components of&nbsp / the updated conceptual model identified and investigated include the physical environment, the calculated hydraulic and transport properties.The ash dump can be conceptualized as a 20 to&nbsp / &nbsp / 30 meter high heap of consolidated clay size ash&nbsp / particles built on top of an underlying shallow weathered dolerite aquifer. The ash dup is directly connected to the underlying weathered&nbsp / dolerite aquifer. The saline water within the saturated zone has the ability to move through the ash dump system with hydraulic conductivities ranging between 10-1-10- 2 m/day, with flow&nbsp / velocities of 7-8m/day and effective porosities of 1%-2%. The hydraulic properties of the ash dump are, amongst others, controlled by the ash geology, contact time of the process water with the&nbsp / sh and show a significant reduction in hydraulic conductivity over time, before reaching a steady state. The transport properties are controlled by advection and spreading in available&nbsp / pathways. Results for the surrogate underlying fractured rock aquifer show flow velocities of 31m/day and an effective porosity of 1%.This suggests that the underlying weathered dolerite&nbsp / aquifer is vulnerable to process water contamination from the ash dump system. The study illustrates the importance of a site conceptual model before the application of investigative&nbsp / methods. Hence having a site conceptual model provides an excellent platform for hydraulic and transport estimation. The development of a site conceptual model enhanced the&nbsp / understanding of flow and transport movement of the processed&nbsp / water trough the ash dump, it also assisted as a beneficial tool to enhance ash dump management.</p>

The copy-and-paste paradigm is a fundamental operation in graphical user interfaces. However, existing copy-and-paste techniques have limitations, in particular in terms of efficiency and robustness against interruptions. This thesis is focusing on improving the user interface used to copy-and-paste objects across different contexts, such as a series folders. To improve this fundamental operation, a new copy-and-paste technique, called Bag-and-Dump, is proposed, implemented and evaluated. Bag-and-Dump aims to substantially reduce mouse movement by allowing the user to gather up (‘bag’) source data across different folders before ‘dumping’ the whole load at the destination. Additionally, Bag-and-Dump provides constant visual feedback in the form of a bag-like semantic cursor to increase robustness against interruptions. Bag-and-Dump was eval- uated against two standard copy-and-paste techniques (Keyboard Shortcuts and Drag-and-Drop) under a different number of contexts (folders) and with and without inter- ruptions. Results from the experiment not only showed that Bag-and-Dump indeed significantly reduces mouse movement, it also confirmed that Bag-and-Dump was 9% faster than Keyboard Shortcuts, one of the most popular copy-paste techniques among “expert users”.

Thymidylate synthase (TS), encoded by the ThyA gene, is essential for the growth and survival of Mycobacterium tuberculosis and therefore is a potential drug target. Thymidylate synthase binds both a substrate, 2'-deoxyuridine-5'monophosphate (dUMP) as well as a cofactor, (6R,S)-5,10-methylenetetrahydrofolate (mTHF), providing the ability to inhibit a single target by two separate classes of molecules. 5'-fluoro-2'-deoxyuridine-5'-monophosphate (FdUMP) is a very tight binding mechanism based inhibitor, shown to have a Ki of 2nM for Mtb TS. Pemetrexed and Raltitrexed are both anti-folates, targeting the cofactor binding site of thymidylate synthase. The x-ray crystal structures of Mycobacterium tuberculosis thymidylate synthase were solved in the binary complexes ThyA-dUMP and ThyA-FdUMP at 2.5 A and 2.4 A resolutions, respectively. The ternary complex, ThyA-dUMP-Pemetrexed was solved to a resolution of 1.7 A. The enzyme is comprised of 8 alpha-helices as well as 23% of the protein formed by beta-sheets, including the dimer interface which is a beta-sandwich. Examination of the dUMP binding site allowed the identification of key conserved residues that play a role in ligand binding and catalysis. Comparison of the dUMP-Pemetrexed ternary complex with that of the human crystal structure shows two fewer interactions in the Mtb enzyme. One is due to the replacement of a Met with a Val which doesn't allow hydrophobic interactions with the ring system of Pemetrexed, and the other is the replacement of an Asn with a Trp, depriving the Mtb protein of a hydrogen bond at the N7 of the pyrrolo ring. A spectrophotometric assay that monitored DHF formation was used to determine the inhibition of Pemetrexed and Raltitrexed on Mtb TS. Both were verified as noncompetitive inhibitors, and Pemetrexed was found to have an IC50 of 17muM and a Ki of 16.8muM, while Raltitrexed had an IC50 of 3.5muM and a Ki of 3.2muM.

Submitted by Maria Lucia Solera (lucinha@ipt.br) on 2018-04-05T14:54:47Z No. of bitstreams: 1 Solera_Maria_Lucia.pdf: 7380822 bytes, checksum: b8c2f83d71228edc0643d9c3ef334ac5 (MD5) / Approved for entry into archive by Bruna Bacalgini null (bruna@sorocaba.unesp.br) on 2018-04-05T17:53:42Z (GMT) No. of bitstreams: 1 solera_ml_dr_soro.pdf: 7380822 bytes, checksum: b8c2f83d71228edc0643d9c3ef334ac5 (MD5) / Made available in DSpace on 2018-04-05T17:53:42Z (GMT). No. of bitstreams: 1 solera_ml_dr_soro.pdf: 7380822 bytes, checksum: b8c2f83d71228edc0643d9c3ef334ac5 (MD5) Previous issue date: 2018-03-09 / A mineração representa um importante setor na economia promovendo diversos benefícios econômicos e sociais ao país. Ainda que apresente impactos positivos, os cenários da degradação originados pela atividade minerária causam impactos negativos ao meio ambiente, dificultando a recuperação da área degradada. Esta pesquisa discute a aplicabilidade da bioengenharia de solos como estratégia promissora para recuperar um talude de pilha de estéril. Esse talude está constituído por materiais de diferentes granulometrias, alta declividade e elevado índices de vazios, características físicas que podem afetar o desenvolvimento ou mesmo a recolonização da vegetação nativa por processos naturais de sucessão. Três modelos estruturais de bioengenharia de solos denominados de guirlanda, colmeia e retentor foram confeccionados para reter mistura de solo-substrato/sementes de Crotalaria juncea, Mucuna aterrina e Cajanus cajan como adubos verdes visando à produção de matéria orgânica e promover as condições necessárias para posterior revegetação do talude. Os resultados obtidos com aplicação dos índices desenvolvidos para avaliar os modelos indicam que a guirlanda apresentou melhor resultado, destacando-se a baixa dificuldade de instalação do modelo no talude, a baixa dificuldade de preenchimento do solo-substrato/sementes no modelo e o alto desenvolvimento da adubação verde. O segundo melhor desempenho foi alcançado pelo modelo retentor seguido pelo modelo colmeia com o pior desempenho. Na análise dos bioindicadores ambientais do solo, a guirlanda apresentou melhor resultado na produção da matéria orgânica, em número de morfoespécies e em numero de indivíduos da fauna edáfica, seguindo pelos modelos retentor e colmeia. Os critérios preestabelecidos especificamente para avaliar esses modelos indicam potencial de aplicabilidade em futuros projetos de pesquisas para recuperar situações similares de degradação em áreas de mineração a céu aberto. / Mining represents an important sector in the economy promoting many economic and social benefits to the country. Although this represents positive impacts, the degradation scenarios originated by the mining activity cause negative impacts to the environment, which difficult the recovery of the degraded area. This research discusses the applicability of soil bioengineering as a promising strategy for recovering a slope of a waste dump. This slope consists of materials of different granulometries, high slope and high void ratio, physical characteristics that can hinder the development or even the recolonization of native vegetation by natural succession processes. Three soil bioengineering structural models, named as guirlanda, colmeia and retentor were made to retain a mix of soilsubstrate and seeds of Crotalaria juncea, Mucuna aterrina and Cajanus cajan as green manures for the production of organic matter and to promote the necessary conditions for future revegetation of the slope. The results obtained with application of the indices developed to assess the models indicate that guirlanda presented the best results, with highlights for the low difficulty in installing the model on the slope, the low difficulty of filling the model with the mix of soil-substrate and seeds and the high development of green manure. The second best performance was achieved by retentor model followed by the worst performing colmeia model. In the analysis of soil environmental bioindicators, guirlanda presented better results in the production of organic matter, in number of morphospecies and in number of individuals of the edaphic fauna, followed by the models retentor and colmeia. The specifically pre-established criteria to assess these models indicate the potential applicability in future research projects to recover similar situations of degradation in open pit mining areas.