The performance of ground-source heat pump (GSHP) systems can be negatively affected over time by soil temperature degradation of boreholes (BH) in heating dominated climates. Land area is scarce in the dense urban environments typical of multi-family houses (MFH) and can lead to accelerated degradation- in tight BH fields. Heat extracted from photovoltaic thermal collectors (PVT) can help with BH regeneration; thus, limiting degradation. Additionally, free cooling (FC) is proposed in this study to tackle the anticipated cooling demandi ncrease in Sweden, while resolving the listed challenges of GSHP systems. A novel multi-source (MS) system integrating FC, PVT and GSHP together shall be investigated in this study. Firstly, implementing FC in a GSHP system for the scenario considered only provided marginal regeneration of the BH in the longterm. Both the SPF4+ and total life cycle cost (TLCC) of an FC+GSHP and GSHPsystem remained virtually constant. Furthermore, operation interference of FC and PVT in the MS system can be mitigated by considering their relative location in the system. In this study, cooling is the priority, thus placing the FC system after the BH field but before the PVT system in the brine loop is recommended. In that case, only 0.56% of the annual cooling is not delivered due to FC operation interference and the PVT thermal yield is decreased on average by 3.52%. By decreasing the BH spacing from 15 to 5 m, a slight SPF4+ increase to 3.22 is possible in a system with FC and 48 PVT collectors. With a sensitivity analysis it was shown that if a 15% decrease is achieved in electricity prices then the TLCC of this system can be lower than the TLCC of 2.13 MSEK for a GSHP system. / Prestandan hos ytjordvärmepump (GSHP) kan påverkas negativt över tid av försämrad marktemperatur i borrhål (BH) i klimat som domineras av uppvärmning. I täta stadsmiljöer med flerfamiljshus (MFH) är markytan knapp, vilket kan leda till accelererad nedbrytning i trånga BH-fält. Värme som utvinns från solfångare (PVT) kan bidra till regenerering av BH, vilket begränsar nedbrytningen. Dessutom föreslås frikyla (FC) i denna studie för att hantera den förväntade ökningen av kylbehovet i Sverige, samtidigt som man löser de listade utmaningarna med GSHP-system. Ett nytt multikällsystem (MS) som integrerar FC, PVT och GSHP tillsammans ska undersökas i denna studie. För det första gav implementeringen av FC i ett GSHP-system för det aktuella scenariot endast marginell regenerering av BH på lång sikt. Både SPF4+ och den totala livscykelkostnaden (TLCC) för ett FC+GSHP och GSHP-system förblev praktiskt taget konstant. Dessutom kan driftstörningar från FC och PVT i MS-systemet minskas genom att ta hänsyn till deras relativa placering i systemet. I denna studie prioriteras kylning, och därför rekommenderas att FC-systemet placeras efter BH-fältet men före PVT-systemet i brineslingan. Endast 0.56% av den årliga kylningen levereras inte på grund av störningar i FC-driften och PVT:s värmeutbyte minskar i genomsnitt med 3.52%. Genom att minska BH-avståndet från 15 till 5 m är en liten ökning av SPF4+ till 3.22 möjlig i ett system med FC och 48 PVT-kollektorer. En känslighetsanalys visade att om elpriserna minskar med 15% kan TLCC för detta system bli lägre än TLCC på 2.13 MSEK för ett GSHP-system.

Den svenska regeringen har beslutat om en strategi för IT-politiken, där målet är att Sverige ska vara bäst i världen på att använda digitaliseringens möjligheter. Dessa möjligheter kommer öppna upp för en enklare vardag för privatpersoner och företag. Flera kommuner har idag samarbeten med EU, regioner och kommuner där syftet är att digitalisera samhällsbyggnadsprocessen med hjälp av att utveckla innovativa digitala verktyg. Offentliga utredningar har påvisat brister i hur lösningarna presenteras och att det finns utvecklingspotential. I nuläget presenteras information för allmänheten i form av text och bilder, vilket ger en ofullständig bild av pågående och framtida byggprojekt. Tidigare studier inom andra områden har visat att 3D-teknik kan vara värdefullt på en bred front. Syftet med studien var att undersöka hur 3D-kartor påverkar användbarheten och förståelsen hos allmänheten i medborgardialoger inom samhällsbyggnadsprocessen. Studien berörde även hur processens virtualiserbarhet påverkas. Som teoretiskt ramverk och principer som underlag för studien, användes modellen Process Virtualization Theory (PVT) och användbarhet. Inom det sistnämnda används komponenter som effektivitet, fel, minnesbarhet, lärbarhet och tillfredsställelse för att mäta användbarheten av tjänsterna. PVT-modellen kan användas för att mäta hur lämpad en process är att vara digital och huruvida IT kan möjliggöra en bättre digital process eller inte. Studien har en genomgående kvalitativ ansats som undersökte  användbarheten och hur lämpad processen är att vara digital. Användbarhetstest med kompletterande intervjuer utfördes under två separata tillfällen där det ena riktades mot en befintlig webbtjänst och den andra mot en ny webbtjänst med en 3D-karta.  Resultatet i användandet av 3D-kartan påvisade att igenkänning och ovana är två återkommande teman där tillfredsställelse uppvisas i form av nyfikenhet och intresse. I jämförelse mellan webbtjänsterna så bidrog 3D-kartan till en ökad visuell förståelse av informationen som presenterades. Å andra sidan gav informationsdokumenten en djupare förståelse. 3D-kartan påverkade den undersökta processen positivt och var framförallt användbar för den visuella förståelsen. Processen var lämpad för att vara digital där representationen var en bidragande faktor för vad IT möjliggjorde. / The Swedish government has decided on a strategy for IT policy where the goal is for Sweden to be the best in the world at utilizing the possibilities of digitalisation. These opportunities will open up for a simpler everyday life for individuals and companies. Several municipalities today have collaborations with the EU, regions and municipalities where the purpose is to digitize the community building process with the help of developing innovative digital tools. Public investigations have shown shortcomings in how the solutions are presented and that there is development potential. At present, information is presented to the public in the form of text and images, which gives an incomplete picture of ongoing and future construction projects. Previous studies in other areas have shown that 3D technology can be valuable on a broad front. The purpose of the study was to investigate how 3D maps affect the public's usefulness and understanding in citizen dialogues in the community building process. The study also touched on how the virtualisability of the process is affected. As a theoretical framework and principles as a basis for the study, the model Process Virtualization Theory (PVT) and usability were used. Within usability, components such as efficiency, error, memorability, learnability and satisfaction are used to measure the usefulness of the services. The PVT model can be used to measure how appropriate a process is to be digital and whether IT can enable a better digital process or not. The study has a consistent qualitative approach that relates to examining usability and how appropriate the process is to be digital. Usability tests with supplementary interviews were performed on two separate occasions, where one is aimed at an existing web service and the other at a new web service with a 3D map. The results in the use of the 3D map showed that recognition and unfamiliarity are two recurring themes where satisfaction is shown in the form of curiosity and interest. In comparison between the web services, the 3D map contributed to an increased visual understanding of the information presented. However, the information documents provided a deeper understanding. The 3D map proved to have a positive effect on the investigated process and was above all useful for the visual understanding. The process also proved to be suitable for being digital, where representation was a contributing factor to what IT made possible.

Duty cycle and frequency are important characteristics of periodic signals that are exploited to develop a variety of application circuits in IC design. Controlling the duty cycle and frequency provides a method to develop adaptable circuits for a variety of applications. These applications range from stable on-chip clock generation circuits, on-chip voltage regulation circuits, and Physical unclonable functions for hardware security applications. Ring oscillator circuits that are developed with CMOS inverter circuits provide a simple, versatile flexible method to generated periodic signals on an IC chip. A digitally controlled ring oscillator circuit can be adapted to control its duty cycle and frequency. This work describes a novel current starved ring oscillator, with digitally controlled current source based headers and footers, that is used to provide a versatile duty cycle and a precise frequency control. Using this novel circuit, the duty cycle and frequency can be adapted to a wide range of values. The proposed circuit achieves i) a controlled duty cycle that can vary between 20% and 90% with a high granularity and ii) a compensation circuit that guarantees a constant duty cycle under process, voltage, and temperature (PVT) variations. A novel application of the proposed PWM circuit is the design and demonstration of a reliable and reconfigurable Duty-cycle based Physical unclonable function (PUF). The proposed PWM based PUF circuit is demonstrated to work in a reliable and stable operation for a variety of process, voltage and temperature conditions with circuit implementations using 22nm and 32nm CMOS technologies. A comparative presentation of the duty cycle based PUF are provided using standard PUF figures of merits.

Embedded memories dominate area, power and cost of modern very large scale integrated circuits system on chips ( VLSI SoCs). Furthermore, due to process variations, it becomes challenging to design reliable energy efficient systems. Therefore, fault-tolerant designs will be area efficient, cost effective and have low power consumption. The idea of this project is to design embedded memories where reliability is intentionally compromised to increase storage density. Gain cell memories are smaller than SRAM and unlike DRAM they are logic compatible. In multilevel DRAM storage density is increased by storing two bits per cell without reducing feature size. This thesis targets multilevel read and write schemes that provide short access time, small area overhead and are highly reliable. First, timing analysis of reference design is performed for read and write operation. An analytical model of write bit line (WBL) is developed to have an estimate of write delay. Replica technique is designed to generate the delay and track variations of storage array. Design of replica technique is accomplished by designing replica column, read and write control circuits. A memory controller is designed to control the read and write operation in multilevel DRAM. A multilevel DRAM is with storage capacity of eight kilobits is designed in UMC 90 nm technology. Simulations are performed for testing and results are reported for energy and access time. Monte Carlo analysis is done for variation tolerance of replica technique. Finally, multilevel DRAM with replica technique is compared with reference design to check the improvement in access times.

In a conventional charge-pump based PLL design, the loop parameters such as the band-width, jitter performance, charge-pump current, pull-in range among others govern the ar-chitecture and implementation details of the PLL. Different loop parameter specificationschange with a change in the reference frequency and inmost cases, requires careful re-designof some of the PLL blocks. This thesis describes the implementation of a semi-digital PLLfor high bandwidth applications, which is self-compensated, low-power and exhibits band-width tracking for all reference frequencies between 40 MHz and 1.6 GHz in 65nm CMOStechnology.This design can be used for a wide range of reference frequencies without redesigning anyblock. The bandwidth can be fixed to some fraction of the reference frequency during designtime. In this thesis, the PLL is designed to make the bandwidth track 5% of the referencefrequency. Since this PLL is self-compensated, the PLL performance and the bandwidthremains same over PVT corners.

This thesis is composed of two parts : a 3¡ÑVDD bidirectional mixed-voltage-tolerant I/O buffer, and a 2¡ÑVDD output buffer with process and temperature compensation. In the first topic, a 3¡ÑVDD bidirectional mixed-voltage-tolerant I/O buffer, which is able to tolerate 3¡ÑVDD using stacking transistors in the output stage, is proposed. These transistors are biased by corresponding voltage levels which are generated by a dynamic gate bias generator and a floating N-well circuit when transmitting or receiving signals. In order to prevent the input stage transistors from gate-oxide overstress, an NMOS clamping technique is used to block high input voltages. This design can receive and transmit 0.9 V to 5.0 V (0.9/1.2/1.8/2.5/3.3/5.0 V) signals, which has been implemented using TSMC 1P6M 0.18 £gm CMOS process. The second topic shows a 2¡ÑVDD output buffer with process and temperature compensation using 1P6M 0.18 £gm CMOS process. In this design, a novel process and temperature variation detector is proposed to detect the corners of NMOS and PMOS, respectively. The driving capability of the output stage is enhanced at those corners with low output currents. By contrast, the driving currents is reduced at those corners with high output currents to reduce the variation of output slew rate.

Reservoir simulation studies are one of the key tools in an integrated reservoir management study. A successful reservoir simulation application requires representative input data for reservoir rock and fluid properties. This study aims to develop a road map from laboratory measurements to the input data file of reservoir simulation and to make a probabilistic approach for the estimation of unknown parameters. Raw data of reservoir rock and fluid properties of a selected oil field of Turkey will be interpreted and prepared in a way that they will be used as input data of a simulator.

Driven by the limitations of solar-optimized roof space and International Energy Association (IEA) Task 35, there is a renewed interest in photovoltaic solar thermal (PVT) hybrid systems. Current PVT systems focus on cooling the solar photovoltaic (PV) cells to improve the electrical performance. This however, causes the thermal component (T) to underperform. An exergetic study was completed comparing a PVT, PV + T and a PV only system in Detroit, Denver and Phoenix. It was found that the PVT system outperformed the PV + T system by 72% for each location and by 8, 8.6 and 9.9% for Detroit, Denver and Phoenix when compared to the PV only system. To further improve the PVT system, using hydrogenated amorphous silicon (a-Si:H) PV as the absorber layer of the solar thermal device was explored. The temperature coefficient and annealing properties of a-Si:H allow the thermal component to run more efficiently, while enabling the a-Si:H i-layers to be thicker resulting in more electricity production. It was found that running i-layer thicker cells (630nm and 840nm) stabilized at higher efficiencies at 90°C (potential PVT operating temperatures) than the thinner cell (420nm) by 2% and 0.5% respectively. In addition, spike annealing, which is a new concept of stagnating a PVT system to allow for the a-Si:H PV to anneal and return it to its original efficiencies was also investigated. It was found that over the lifetime of the system with the spike annealing occurring once a day 10.6% more electricity was produced than a system without stagnation. / Thesis (Master, Mechanical and Materials Engineering) -- Queen's University, 2011-11-14 11:09:16.727

“Introduction to the Canadian Oil Sands”, “Canada’s Oil Sand Industry: An Overview”, “Heavy Oil Technologies”, and so many other topics about heavy oil have become the hotcakes in the oil industry. A number of new projects are in Execute phase for the development of heavy oil assets. This clearly shows the increasing demand for heavy oil. An oil industry is working hard to meet the world oil demand by developing deep water, HPHT, heavy oil, shale sands and all other non-conventional reservoirs but the main challenge is to develop and operate them in a risk free environment. Understanding the reservoir and fluid properties and developing new technologies help the industry to reduce the risk in developing non-conventional fields. A major problem in heavy oil field is to understand the behaviour of heavy oil. The viscous oil flows sluggishly in the formations and hence it is difficult to transport through unconsolidated formations and is very difficult to produce by conventional methods. Viscous oil recovery entails neatly designed enhanced oil recovery processes like Steam Assisted Gravity Drainage and the success of such technologies are critically dependent on accurate knowledge of reservoir, well and fluid properties of oil under variety of pressure and temperature conditions. This research project has provided some solutions to the challenges in heavy oil field development and can help the oil industry to optimise heavy oil production. Detailed experimental understanding of PVT properties has allowed this project to contribute to the knowledge. Reservoir, well and fluid properties were studied thoroughly and demonstrated the criticality of each parameter on the efficiency of Steam Assisted Gravity Drainage. An user friendly SAGD simulator is a big output of this research which allows the user to optimise the heavy oil recovery and enables to do risk assessments quickly during design phase of SAGD. A SAGD simulator is developed.

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2017-03-20T20:04:27Z No. of bitstreams: 1 RamonRudaBritoMedeiros_DISSERT.pdf: 9691744 bytes, checksum: b0c63141b5ed151f490bfed5d79bccbc (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2017-03-22T21:18:49Z (GMT) No. of bitstreams: 1 RamonRudaBritoMedeiros_DISSERT.pdf: 9691744 bytes, checksum: b0c63141b5ed151f490bfed5d79bccbc (MD5) / Made available in DSpace on 2017-03-22T21:18:49Z (GMT). No. of bitstreams: 1 RamonRudaBritoMedeiros_DISSERT.pdf: 9691744 bytes, checksum: b0c63141b5ed151f490bfed5d79bccbc (MD5) Previous issue date: 2017-01-25 / O presente trabalho apresenta um estudo de desempenho de um sistema h?brido fotovoltaico/t?rmico (sistema PVT), comparando-o com um sistema fotovoltaico (sistema PV). Foi analisada a pot?ncia el?trica e t?rmica, a efici?ncia e a energia produzida pelos sistemas, correlacionando ? influ?ncia da temperatura do m?dulo PV e a efici?ncia el?trica dos sistemas. O m?dulo fotovoltaico (PV) utilizado foi o MSX 77 da marca SOLAREX, composto por c?lulas solares policristalinas, cuja pot?ncia de pico ? de 77 Watts. O sistema PVT analisado foi do tipo PVT-l?quido, composto pelo m?dulo PV MSX77 e um coletor solar plano do tipo placa fabricado em acr?lico, a alimenta??o de ?gua do coletor foi do tipo for?ada por gravidade e com sistema aberto. Para determinar as curvas caracter?sticas do m?dulo PV e por consequ?ncia a pot?ncia el?trica m?xima gerada, foi desenvolvido um banco de carga formado por resistores de pot?ncia. A pot?ncia t?rmica foi quantificada aferindo a vaz?o da ?gua que alimentava o coletor e a diferen?a de temperatura da ?gua de entrada e sa?da. Com as pot?ncias e a radia??o incidente sobre os sistemas, foram determinadas as efici?ncias. A m?xima efici?ncia el?trica informada pelo fabricante do m?dulo PV ? de 10,8 %, contudo, em condi??es reais de opera??o, a m?xima efici?ncia do m?dulo PV foi de 8,46 %. No sistema PVT, o m?dulo PV apresentou uma efici?ncia m?xima de aproximadamente 7,8 % no ponto de m?xima pot?ncia gerada. A efici?ncia m?dia do sistema t?rmico foi na ordem de 42,5 %. O sistema PVT proporcionou a redu??o da temperatura do m?dulo PV, aumentando a efici?ncia de gera??o el?trica, proporcionando um aumento na ordem dos 6,9 % na energia el?trica m?dia di?ria. O sistema PVT al?m de proporcionar um aumento de energia el?trica, ainda fornece energia t?rmica com uma efici?ncia superior ? el?trica. A ?gua aquecida pode ser utilizada para alimentar sistemas de aquecimento de ?gua para banho, contribuindo para redu??o do consumo de energia el?trica de uma resid?ncia. / The present dissertation presents a performance study of a hybrid photovoltaic / thermal system (PVT system), comparing it with a photovoltaic system (photovoltaic system). The electrical and thermal power, efficiency and energy produced by the systems were analyzed, correlating the influence of the temperature of the photovoltaic module and the electrical efficiency of the systems. The photovoltaic (PV) module used was the MSX 77 of the brand SOLAREX, composed of polycrystalline solar cells, whose peak power is 77 Watts. The PVT system analyzed was of the PVT-liquid type, composed of the MSX77 photovoltaic module and a flat plate type solar collector made of acrylic, the water supply of the manifold was forced by gravity and with open system. To determine the characteristic curves of the PV module and consequently the maximum electric power generated, a load bank formed by power resistors was developed. The thermal power was quantified by measuring the flow of the water that fed the collector and the difference in temperature of the incoming and outgoing water. With the powers and the radiation incident on the systems, the efficiencies were determined. The maximum electrical efficiency reported by the manufacturer of the PV module is 10.8 %, however, under actual operating conditions, the maximum efficiency of the PV module was 8.46 %. In the PVT system, the PV module showed a maximum efficiency of approximately 7.8 % at the point of maximum power generated. The average efficiency of the thermal system was around 42.5 %. The PVT system provided a reduction in the temperature of the PV module, increasing the efficiency of electric generation, providing an increase in the order of 6.9 % in the average daily electric energy. The PVT system, besides providing an increase in electrical energy, still provides thermal energy with a higher efficiency than electric. The heated water can be used to power water heating systems for bathing, contributing to reduce the consumption of electric energy of a residence.