This thesis provides a feasibility study on the determination of formation anisotropy parameters from logging-while-drilling (LWD) borehole acoustic measurements. For this reason, the wave propagation in fluid-filled boreholes surrounded by transverse isotropic (TI) formations is investigated in great detail using the finite-difference method. While the focus is put on quadrupole waves, the sensitivities of monopole and flexural waves are evaluated as well. All three wave types are considered with/without the presence of an LWD tool. Moreover, anisotropy-induced mode contaminants are discussed for various TI configurations. In addition, the well-known plane wave Alford rotation has been generalized to cylindrical borehole waves of any order, except for the monopole. This formulation has been extended to allow for non-orthogonal multipole firings, and associated inversion methods have been developed to compute formation shear principal velocities and accompanying polarization directions, utilizing various LWD (cross-) quadrupole measurements.:1 Introduction 1.1 Borehole acoustic configurations 1.2 Wave propagation in a fluid-filled borehole in the absence of a logging tool 1.3 Wave propagation in a fluid-filled borehole in the presence of a logging tool 1.4 Anisotropy 2 Theory 2.1 Stiffness and compliance tensor 2.1.1 Triclinic symmetry 2.1.2 Monoclinic symmetry 2.1.3 Orthotropic symmetry 2.1.4 Transverse isotropic (TI) symmetry 2.1.5 Isotropy 2.2 Reference frames 2.3 Seismic wave equations for a linear elastic, anisotropic medium 2.3.1 Basic equations 2.3.2 Integral transforms 2.3.3 Christoffel equation 2.3.4 Phase slowness surfaces 2.3.5 Group velocity 2.4 Solution in cylindrical coordinates for the borehole geometry 2.4.1 Special case: vertical transverse isotropy (VTI) 2.4.2 General case: triclinic symmetry 3 Finite-difference modeling of wave propagation in anisotropic media 3.1 Finite-difference method 3.2 Spatial finite-difference grids 3.2.1 Standard staggered grid 3.2.2 Lebedev grid 3.3 Heterogeneous media 3.4 Finite-difference properties and grid dispersion 3.5 Initial conditions 3.6 Boundary conditions 3.7 Parallelization 3.8 Finite-difference parameters 4 Wave propagation in fluid-filled boreholes surrounded by TI media 4.1 Vertical transverse isotropy (VTI) 4.1.1 Monopole excitation 4.1.2 Dipole excitation 4.1.3 Quadrupole excitation 4.1.4 Summary 4.2 Horizontal transverse isotropy (HTI) 4.2.1 Monopole excitation 4.2.2 Theory of cross-multipole shear wave splitting 4.2.3 Dipole excitation 4.2.4 Quadrupole excitation 4.2.5 Hexapole waves 4.2.6 Summary 4.3 Tilted transverse isotropy (TTI) 4.3.1 Monopole excitation 4.3.2 Dipole excitation 4.3.3 Quadrupole excitation 4.3.4 Summary 4.4 Anisotropy-induced mode contaminants 4.4.1 Vertical transverse isotropy (VTI) 4.4.2 Horizontal transverse isotropy (HTI) 4.4.3 Tilted transverse isotropy (TTI) 4.4.4 Summary 5 Inversion methods 5.1 Vertical transverse isotropy (VTI) 5.2 Horizontal transverse isotropy (HTI) 5.2.1 Inverse generalized Alford rotation 5.2.2 Inversion method based on dipole excitations 5.2.3 Inversion method based on quadrupole excitations 5.3 Tilted transverse isotropy (TTI) 5.4 Challenges in real measurements 5.4.1 Signal-to-noise ratio (SNR) 5.4.2 Tool eccentricity 6 Conclusions References List of Abbreviations and Symbols List of Figures List of Tables A Integral transforms A.1 Laplace transform A.2 Spatial Fourier transform A.3 Azimuthal Fourier transform A.4 Meijer transform B Stiffness and compliance tensor B.1 Rotation between reference frames B.2 Cylindrical coordinates C Christoffel equation C.1 Cartesian coordinates C.2 Cylindrical coordinates D Processing of borehole acoustic waveform array data D.1 Time-domain methods D.2 Frequency-domain methods D.2.1 Weighted spectral semblance method D.2.2 Modified matrix pencil method

Bei oberflächennahen geothermischen Anwendungen kommt es zu Temperaturveränderungen im Untergrund, um Wärme zu gewinnen oder zu speichern. Die dadurch verursachten thermischen Auswirkungen können die thermischen, hydraulischen und chemischen Bedingungen des Untergrunds verändern und sich auf die Systemleistung auswirken. Die Situation wird noch komplizierter, wenn die Grundwasserleiter unterschiedlich gesättigt sind und eine Verunreinigung des Untergrunds vorliegt. In dieser Arbeit werden vollständig gekoppelte Wärme- und Stofftransportmodelle angewandt, um die Wechselwirkung zwischen oberflächennahen geothermischen Anwendungen und der unterirdischen Umgebung besser zu charakterisieren. Es werden drei verschiedene Szenarien untersucht. Zunächst werden die thermischen Auswirkungen und die Nachhaltigkeit einer intensiven oberflächennahen geothermischen Nutzung in einem Wohngebiet über einen Zeitraum von 24 Jahren bewertet. Überwachungsdaten des Standorts werden in das Modell integriert, und die Bedeutung standortspezifscher Kenntnisse für die Planung wird hervorgehoben. Zweitens wird der gekoppelte Feuchtigkeits- und Wärmetransport eines Erdwärmespeichersystems (BTES) untersucht. Es wird eine Sensitivitätsanalyse durchgeführt und die Wärmeentzugsefzienz zwischen verschiedenen Szenarien verglichen. Bei Austrocknung oder starker Gasphasenkonvektion werden signifkante Änderungen im Wärmetransportverhalten erwartet. Drittens wird ein nichtisothermes Drei-Komponenten-Zweiphasenströmungsmodell abgeleitet und mit der Finite-Elemente-Methode implementiert. Die Validierung des numerischen Modells bestätigt seine Fähigkeit, die gekoppelte Strömung sowie den Wärme- und Stofftransport in einem ungespannten Grundwasserleiter zu simulieren, der einem BTES-Betrieb ausgesetzt ist. Insbesondere wird das Potenzial für die thermisch verstärkte Verflüchtigung von Trichlorethylen (TCE) in wässriger Phase bewertet. Da durch die Wärmezufuhr eine Auftriebsströmung induziert wird, nimmt die Verringerung der Schadstoffmasse erheblich zu und erreicht nach fünf Jahren mehr als 70 %. Die in dieser Arbeit gewonnenen Erkenntnisse können durch die Verbesserung ihrer ökologischen und ökonomischen Leistungen zu einer breiteren Akzeptanz von Technologien der flachen Geothermie beitragen. / Shallow geothermal applications induce temperature changes in the subsurface for heat extraction or storage purposes. Their induced thermal impacts may alter the thermal, hydraulic, and chemical conditions of the subsurface and feedback on the system performance. The situation is further complicated in variably saturated aquifers and when subsurface contamination exists. In this work, fully coupled heat and mass transport models are applied to improve the characterization of interaction between shallow geothermal applications and the subsurface environment. Three different scenarios are investigated. First, the thermal impact and sustainability of intensive shallow geothermal exploitation in a residential area is evaluated over a 24-year period. Monitoring data from the site is integrated into the model and the importance of site-specifc knowledge for planning is highlighted. Second, the coupled moisture and heat transfer of a soil borehole thermal energy storage (BTES) system is explored. A sensitivity analysis is performed and the heat extraction efciency is compared among various scenarios. Signifcant changes in the heat transport behavior are expected when drying out or strong gas phase convection occurs. Third, a non-isothermal three-component two-phase flow model is derived and implemented with the fnite element method. Validation of the numerical model confrms its ability to simulate the coupled flow, heat and mass transport in an unconfned aquifer subject to BTES operation. In particular, the potential for thermally-enhanced volatilization of aqueousphase trichloroethylene (TCE) is assessed. As buoyant flow is induced due to heat injection, reduction of the contaminant mass grows considerably, reaching more than 70% after fve years. The fndings obtained from this thesis can contribute to a wider adoption of shallow geothermal technologies through the enhancement of their environmental and economical services.

[pt] Ondas ultrassônicas guiadas são usadas em larga escala em ensaios não destrutivos (END) e Structural Health Monitoring (SHM), permitindo a inspeção de estruturas e equipamentos de forma não invasiva. A partir da transmissão de um sinal acústico sobre uma estrutura e a captação dos sinais de onda propagados por meio de sensores posicionados estrategicamente, é possível obter informações materiais do objeto inspecionado. Na área de óleo e gás, o uso desse tipo de ondas acústicas é de grande importância no levantamento do perfil da camada de cimento que reveste poços, que tem função de conferir integridade estrutural e isolar a estrutura interna de produção do poço das regiões freáticas do entorno. No processo de desativação e abandono do poço, é fundamental avaliar a qualidade do isolamento hidráulico do cimento, assim como identificar possíveis defeitos. A propagação de ondas guiadas em uma estrutura se dá, em geral, por meio de múltiplos modos e apresenta característica dispersiva, que se traduz numa dependência da velocidade de fase das ondas com a frequência, e uma relação não linear entre número de onda e frequência. A relação de dispersão carrega informações do meio de propagação, tal como constantes elásticas e dimensões, e pode ser visualizada a partir de curvas no plano frequência-número de onda (f-k). Diferentes técnicas vêm sendo exploradas para a obtenção das relações de dispersão a partir de sinais no domínio do tempo captados por sensores ultrassônicos em posições espaciais distintas. Este trabalho explora três métodos distintos para a extração das curvas de dispersão, ou seja, obter os pontos f-k associados aos modos de propagação, a partir de um conjunto de sinais dependentes do espaço-tempo. O primeiro algoritmo se baseia em uma técnica pré-existente que usa uma Transformada de Fourier bidimensional (2-D FT) sobre a matriz de dados de sinais de sensores ultrassônicos no espaço-tempo, gerando uma matriz de amplitudes no plano f-k onde os máximos locais representam pontos pertencentes a curvas de dispersão. A representação da matriz como uma imagem f-k permite a visualização das curvas de dispersão como conjuntos contíguos de pixels de maior claridade. Propõe-se um novo algoritmo baseado em operações morfológicas de processamento de imagem para a identificação de pixels relativos aos pontos das curvas de dispersão na imagem f-k, após um préprocessamento da mesma. A segunda técnica consiste no pré-processamento dessa mesma imagem f-k, obtida pela 2-D FT, e uso de um algoritmo préexistente de detecção de estruturas curvilíneas em imagens para identificar os pontos correspondentes às curvas f-k. O terceiro método é uma adaptação, proposta aqui, de um algoritmo pré-existente para estimar os números de onda das curvas de dispersão relativos a cada frequência através de uma matriz Pencil. Propõe-se também um algoritmo original para a separação dos pontos f-k encontrados pelas três técnicas de extração em curvas distintas. Os algoritmos utilizados para a obtenção das curvas de dispersão têm seu desempenho avaliado em três conjuntos de dados distintos de simulações por elementos finitos, a saber, uma de placa de alumínio fina sob distintos valores de tração axial aplicada paralelamente à direção de propagação das ondas; um poço multicamada sem tubing possuindo diferentes tipos de defeito de cimentação-channeling, qualidade de cimento baixa, descolamento interno e externo -, assim como sem defeito; e um pouco multicamada com tubing sob os mesmos defeitos de cimentação e também sem defeito. Compara-se a capacidade dos algoritmos de extração das curvas de dispersão de oferecer informações sobre mudanças materiais entre os casos simulados. Avalia-se também a precisão e custo computacional dos mesmos. / [en] Ultrasonic guided waves are widely used in the fields of Non-Destructive Evaluation (END) and Structural Health Monitoring (SHM), allowing the inspection of structures and pieces of equipment in a non-invasive manner. Through the transmission of an acoustic signal over a given object and the acquisition of the signal from the propagated waves using a group of sensors in predefined positions, it is possible to obtain material information regarding the investigated structure. In the Oil & Gas industry, the use of this type of wave is integral to the logging of the cement layer that outlines the walls of wellbores, which has the purpose of guaranteeing structural support and protecting the well’s internal production structure and the surrounding groundwater from each other. During the deactivation and abandonment of a production well, it is necessary to evaluate the hydraulic isolation of the cement layer, as well as identify possible defects. The propagation of guided waves in a structure is usually multi-modal and of dispersive characteristic. The latter means that the propagating waves phase velocity is dependent on the frequency, translating into a non-linear relationship between wavenumber and frequency. This dispersion relation contains information about the propagating medium, such as elastic constants and dimensions, and can be represented as curves in the frequency-wavenumber (f-k) plane. Different methods are currently being explored for obtaining the dispersion relation from time-domain signals acquired by ultrasonic sensors in different spatial positions. This work explored three different methods for the extraction of the dispersion curves, that is, obtaining the f-k points associated with the modes of propagation, from a dataset composed of space-time signals. The first algorithm is based on a pre-existing technique that uses the bidimensional Fourier Transform (2-D FT) over the matrix containing the space-time signals from the ultrasonic sensors, generating an f-k matrix whose local maximas correspond to points belonging to dispersions curves. The representation of the matrix as an f-k image shows the dispersion curves as contiguous groups of pixels with elevated brightness. A new algorithm is proposed, based on morphological operations from image-processing, to identify the pixels relative to the f-k points of the dispersion curves in the image, after pre-processing is performed. The second technique consists of pre-processing the same fk image, obtained from the 2-D FT, and the use of an existing algorithm for the detection of curvilinear structures in images to identify the points corresponding to the f-k curves. The third method proposes the adaptation of an existing method of estimation of the wavenumbers associated with the dispersion curves for different frequencies, using a matrix Pencil. This work also proposes an original algorithm to separate the f-k points, retrieved by the three techniques, in different curves associated with each mode of propagation. The algorithms used here for the estimation of the dispersion curves are evaluated over three distinct datasets of finite elements simulation: a thin aluminum plate under different values of axial traction parallel to the direction of propagation of the waves; a multilayer wellbore without tubing, with different types of cement defects-channeling, low cement quality, internal and external decoupling-, and without defect; a multilayer wellbore with tubing with the same cement defects and with no defect. Finally, a comparison is drawn over the capacity of the extraction algorithms of providing information regarding changes in the material qualities of the simulated objects. The work also evaluates the precision and computational performance of the aforementioned algorithms.

Studien använder linjärprogrammering för att optimera driften av det termiska energisystemet på Karlstad centralsjukhus ur ett ekonomiskt perspektiv. Bakgrunden till studien är de höga elpriser som rådde under slutet av 2021 samt att det i dagsläget finns kunskapsluckor angående hur systemet bör köras optimalt. Studien baseras på driftdata från 2021. Energisystemet som optimeras är uppbyggt av kylvärmepumpar, bergvärmepumpar, kylmaskiner, frikyla, fjärrvärme och marklager. Ett förhållande för hur många kWh termisk energi som produceras per tillförd kWh el tas fram för samtliga komponenter, vilket sedan används för att modellera energisystemet. Optimering av systemet ger vilka komponenter som skall användas vid olika tidpunkter för att uppfylla ett bestämt värmebehov och kylbehov. Resultatet i form av optimal drift under 2021 analyseras och används för att ta fram driftrekommendationer för energisystemet i framtiden. En metod för att teoretiskt begränsa marklagrets kapacitet vid optimering presenteras. Metodenanvänder nettoenergi till marklagret över en specifik tidsperiod för att approximera temperaturen på brinevätskan ut ur marklagret. Genom att sätta temperaturbegränsningar på brinevätskan kan därigenom nettoenergin till marklagret begränsas. Baserat på data från 2021 tillåts nettoenergin till marklagretvariera mellan -14 700 kWh och 12 500 kWh per 24 timmar. Resultaten visar att det under vintern är fördelaktigt att primärt använda bergvärmepumparna A-D i kombination med frikyla. Sekundärt används kylvärmepumparna E-F. Skillnaden mellan primär och sekundär systemlösning är liten och de båda kan ses som relativt likvärdiga. Fjärrvärme används enbart som sista alternativ under vintern. Energikällan för bergvärmepumparna bör variera mellan Klarälven och marklager med avsikt att utnyttja marklagrets kapacitet optimalt. Vår och höst fallet är till stora delar likvärdigt med vinterfallet med undantaget att det innehåller fler variationer till följd av förändringar i omgivande förutsättningar. Under sommaren bör enbart fjärrvärme användas för att tillgodose värmebehovet. Frikyla och kylmaskinerna 2-3 används för att tillgodose kylbehovet. Frikyla reserveras till att användas under de tidpunkter då kylbehovet är som högst. Effektavgiften för fjärrvärme står för 25,7 % av total driftkostnad i optimalt driftfall. För att minska kostnaderna anses det därför viktigt att kapa effekttopparna för fjärrvärme. Studien undersöker eventuella fördelar med att koppla frikyle-värmeväxlaren mot Klarälven med avsikt att kunna utnyttja den mer än vad som görs i dagsläget. Systemlösningen ger ingen signifikant minskning av driftkostnader vid simulering av ett års drift. Det kan dock vara fördelaktigt att koppla frikyla mot Klarälven ur perspektivet att kunna justera nettoenergin till marklagret för att förhindra långsiktiga temperaturförändringar i berggrunden. Årlig driftkostnad kan minskas genom att öka maxkapaciteten för värmepumparna. En ökning avbergvärmepumparnas kapacitet motsvarande en komponent minskar total årlig kostnad med 4,6 %. En ökning av kylvärmepumparnas kapacitet motsvarande en komponent minskar total årlig kostnad med 1,5 %. Att öka maxkapaciteten för övriga komponenter ger ingen signifikant förändring av årlig driftkostnad. Förbättring av studien innebär att basera modellen på bättre indata samt ta hänsyn till fler detaljer i systemet. Vidare studier bör fokusera på att tillämpa resultaten för att verifiera dem i verkligheten samt göra investeringskalkyler över att utöka kapaciteten för värmepumparna. / The study uses linear programming to optimize the operation of the thermal energy system at Karlstad Central Hospital from an economic perspective. The background to the study is the high electricity prices that occurred at the end of 2021 and the fact that there are currently knowledge gaps regarding how the system should be run optimally. The study is based on operational data from 2021. The energy system that is optimized is made up of cooling heat pumps, ground source heat pumps, cooling machines, free cooling, district heating and ground storage. A ratio for how many kWh of thermal energy that is produced per kWh of supplied electricity was produced for all components, which was then used to model the energy system. Optimization of the system provides which components are to be used at different times to meet a specific heating and cooling demand. The result in the form of optimal operation during 2021 is analyzed and used to produce operating recommendations for the energy system in the future. A method for theoretically limiting the capacity of the ground storage during optimization is presented. The method uses net energy to the ground storage over a specific period of time to approximate the temperature of the brine liquid out of the ground storage. By setting temperature limits on the brine liquid, the net energy to the ground storage can thereby be limited. Based on data from 2021, the net energy to the ground storage is allowed to vary between -14 700 kWh and 12 500 kWh per 24 hours. The results show that during the winter it is advantageous to primarily use the ground source heat pumps A-D in combination with free cooling. Secondary, the cooling heat pumps E-F are used. The difference between primary and secondary system solution is small and the two can be seen as relatively equivalent. District heating is only used as a last resort during the winter. The energy source for the ground source heat pumps should vary between the Klarälven river and the ground storage with the intention of utilizing the capacity of the ground storage optimally. The spring and autumn case is largely equivalent to the winter case, with the exception that it contains more variations as a result of changes in surrounding conditions. During the summer, only district heating should be used to meet the heat demand. Free cooling and cooling machines 2-3 are used to meet the cooling needs. Free cooling is reserved for use during the times when the cooling demand is at its highest.The power fee for district heating accounts for 25.7% of the total operating cost in the optimal operating case. To reduce costs, it is therefore considered important to cut the power peaks for district heating. The study examines the possible benefits of connecting the free cooling heat exchanger to the Klarälven river with the intention of being able to use it more than what is currently the case. The system solution does not provide a significant reduction in operating costs when simulating one year of operation. It might however be advantageous to connect free cooling to the Klarälven river from the perspective of being able to adjust the net energy to the ground storage to prevent long-term temperature changes in the bedrock. Annual operating costs can be reduced by increasing the maximum capacity of the heat pumps. An increase in the capacity of the ground source heat pumps equivalent to one component reduces the total annual cost by 4.6%. An increase in the capacity of the cooling heat pumps equivalent to one component reduces the total annual cost by 1.5%. Increasing the maximum capacity for the other components does not result in a significant change in annual operating costs. Improvements of the study means basing the model on better input data and taking into account more details in the system. Further studies should focus on applying the results to verify them in reality andmake investment calculations regarding expansion of the capacity of the heat pumps

A PhD dissertation which presented a numerical modelling study on the long-term behavior in the multiple borehole heat exchanger array system for sustainable utilisation of shallow geothermal energy.

No description available.

With increasing population comes the concern for waste disposal. The absence of sanitary disposal methods has left most city residents with open landfills as their only source of waste disposal. The resulting leachate formed from the decomposition of these waste materials is highly polluting and finds its way to the underground water supply. The study investigated the effects of open landfill sites on the underground water quality by examining the physical and chemical properties of underground water in hand-dug wells around the Solous landfill sites in Igando, Alimosho Local Government Area of Lagos State. Solous landfill is the second largest landfill by landmass and volume of waste in Lagos State. Systematic random sampling was used for data gathering. Eighteen hand-dug wells were sampled at increasing distances from the landfill site. Physical, chemical and microbiological parameters were analysed at the Lagos State Environmental Protection Agency (LASEPA). Soil samples were also taken from both the A (0 – 30cm) and B (30 – 60cm) horizons of the water sampling points to determine the soil texture (silt, clay and loamy composition) and to show the impact of soil texture on ground water quality within the sampled area. The level of contamination of groundwater was also determined using the Contamination Index method. The results showed high degree of conformance with W.H.O standard with respect to the microbiological properties of the sampled groundwater. However, coliform tests indicated the potential presence of pathogens. Of the seven (7) physical parameters tested, conductivity was higher in one sample. The study of chemical properties from the eighteen wells showed five (5) parameters (dissolved oxygen, total alkalinity, iron, lead, nitrates and copper) above W.H.O limits in some samples. The water may therefore not be safe for human consumption and there is a serious need to monitor the groundwater quality in the area. The level of contamination of groundwater was also determined using the Contamination Index method. Areas of high and medium contamination were discovered. There was no area with low contamination level in the area sampled. Contamination levels were mapped to show the exact levels of contamination in the study area. The results of the soil analysis showed that the study area had soil that was mostly sandy in nature which may suggest an increase in parameters over time with significant health implications for the people who depend on surrounding wells for domestic use. The study also showed no significant variation in water quality with increasing distance from the dump site. Findings also indicated that the water around Solous 1 was of better quality for domestic use than groundwater around Solous 2 and 3 due to temporal reduction of contaminant concentration. There is therefore a need for adequate and proper planning, design and construction, and strategic management disposal of waste, as well as the implementation of a better sustainable environmental sanitation practice. / Environmental Sciences / M. Sc. (Environmental Science)

With increasing population comes the concern for waste disposal. The absence of sanitary disposal methods has left most city residents with open landfills as their only source of waste disposal. The resulting leachate formed from the decomposition of these waste materials is highly polluting and finds its way to the underground water supply. The study investigated the effects of open landfill sites on the underground water quality by examining the physical and chemical properties of underground water in hand-dug wells around the Solous landfill sites in Igando, Alimosho Local Government Area of Lagos State. Solous landfill is the second largest landfill by landmass and volume of waste in Lagos State. Systematic random sampling was used for data gathering. Eighteen hand-dug wells were sampled at increasing distances from the landfill site. Physical, chemical and microbiological parameters were analysed at the Lagos State Environmental Protection Agency (LASEPA). Soil samples were also taken from both the A (0 – 30cm) and B (30 – 60cm) horizons of the water sampling points to determine the soil texture (silt, clay and loamy composition) and to show the impact of soil texture on ground water quality within the sampled area. The level of contamination of groundwater was also determined using the Contamination Index method. The results showed high degree of conformance with W.H.O standard with respect to the microbiological properties of the sampled groundwater. However, coliform tests indicated the potential presence of pathogens. Of the seven (7) physical parameters tested, conductivity was higher in one sample. The study of chemical properties from the eighteen wells showed five (5) parameters (dissolved oxygen, total alkalinity, iron, lead, nitrates and copper) above W.H.O limits in some samples. The water may therefore not be safe for human consumption and there is a serious need to monitor the groundwater quality in the area. The level of contamination of groundwater was also determined using the Contamination Index method. Areas of high and medium contamination were discovered. There was no area with low contamination level in the area sampled. Contamination levels were mapped to show the exact levels of contamination in the study area. The results of the soil analysis showed that the study area had soil that was mostly sandy in nature which may suggest an increase in parameters over time with significant health implications for the people who depend on surrounding wells for domestic use. The study also showed no significant variation in water quality with increasing distance from the dump site. Findings also indicated that the water around Solous 1 was of better quality for domestic use than groundwater around Solous 2 and 3 due to temporal reduction of contaminant concentration. There is therefore a need for adequate and proper planning, design and construction, and strategic management disposal of waste, as well as the implementation of a better sustainable environmental sanitation practice. / Environmental Sciences / M. Sc. (Environmental Science)

This thesis deals with the constructive-technological project of the object "Pool Hall" that is a part of newly built recreational complex. The project includes a technical report, time and financial plan, project construction site equipment, technological specification for monolithic construction, safety principles of construction and building envelope assessment in terms of heat transfer.

The master’s thesis deals with optimization of cooling system of family house using borehole heat exchanger as a single cooling source. In the experimental part of the thesis was carried out long-term mearurements. The main part of the master’s thesis is the development and verification mathematical and physical model of thermal behavior chilled room. The result are computer simulations and evaluation of individual scenarios and design requirements for a potential optimization of measurement and control system. The theoretical part generally deals with radiant cooling systems.