<p>Nanotechnology plays an important role in today’s society because it allows convergence to the nanoscale, that is to say to the level of atoms and molecules, as part of a miniaturization trend; and also because it is being used for improving human performance or enhancement. Nanotechnology will have a tremendous impact thanks to its potentialities, and the human desire for enhancement - and for some even the desire to reach a posthuman stage. Since nanotechnology-based human applications – cyborgs and implants – might represent a threat to what defines us as humans, namely our human nature, a different approach on the distinction between therapy and enhancement is needed in order to handle those applications in a wiser and more responsible way. This thesis will work on such approach.</p>

<p>Hydrogen is considered to be an important potential energy carrier; however, its advantages are unlikely to be realized unless efficient means can be found to produce it without generation of CO₂. Sorption-enhanced steam methane reforming (SE-SMR) represent a novel, energy-efficient hydrogen production route with <i>in situ</i><b> </b>CO₂ capture, shifting the reforming and water gas shift reactions beyond their conventional thermodynamic limits.</p><p>The use of fluidized bed reactors for SE-SMR has been investigated. Arctic dolomite, a calcium-based natural sorbent, was chosen as the primary CO₂-acceptor in this study due to high absorption capacity, relatively high reaction rate and low cost. An experimental investigation was conducted in a bubbling fluidized bed reactor of diameter 0.1 m, which was operated cyclically and batchwise, alternating between reforming/carbonation conditions and higher-temperature calcination conditions. Hydrogen concentrations of >98 mole% on a dry basis were reached at 600°C and 1 atm, for superficial gas velocities in the range of ~0.03-0.1 m/s. Multiple reforming-regeneration cycles showed that the hydrogen concentration remained at ~98 mole% after four cycles. The total production time was reduced with an increasing number of cycles due to loss of CO₂-uptake capacity of the dolomite, but the reaction rates of steam reforming and carbonation seemed to be unaffected for the conditions investigated.</p><p>A modified shrinking core model was applied for deriving carbonation kinetics of Arctic dolomite, using experimental data from a novel thermo gravimetric reactor. An apparent activation energy of 32.6 kJ/mole was found from parameter fitting, which is in good agreement with previous reported results. The derived rate expression was able to predict experimental conversion up to ~30% very well, whereas the prediction of higher conversion levels was poorer. However, the residence time of sorbent in a continuous reformer-calciner system is likely to be rather low, so that only a fraction of the sorbent is utilized, highlighting the importance of the carbonation model at lower conversions.</p><p>A dual fluidized bed reactor for the SE-SMR system was modeled by using a simple two-phase hydrodynamic model, the experimentally derived carbonation kinetics and literature values for the kinetics of steam reforming and water gas shift reactions. The model delineates important features of the process. Hydrogen concentrations of >98 mole% were predicted for temperatures ~600°C and a superficial gas velocity of 0.1 m/s. The reformer temperature should not be lower than 540°C or greater than 630°C for carbon capture efficiencies to exceed 90%. Operating at relatively high solid circulation rates to reduce the need for fresh sorbent, is predicted to give higher system efficiencies than for the case where fresh solid is added. This finding is attributed to the additional energy required to decompose both CaCO₃ and MgCO₃ in fresh dolomite. Moreover, adding fresh sorbent is likely to result in catalyst loss in the purge stream, requiring sorbents with lifetimes comparable to those of the catalyst.</p><p>Thermo gravimetric analysis (TGA) was used to study the reversible CO₂-uptake of sorbents. In general, the multi-cycle capacity of the dolomite was found rather poor. Therefore, synthetic sorbents that maintain their capacities upon multiple reforming-calcination cycles were investigated. A low-temperature liquid phase co-precipitation method was used for synthesis of Li₂ZrO₃ and Na₂ZrO₃. Li₂ZrO₃ showed a superior multi-cycle capacity compared to Arctic dolomite in TGA, but the rate of reaction in diluted CO₂ atmospheres was very slow. The synthesized Na₂ZrO₃ proved to have both fast carbonation kinetics and stable multi-cycle performance. However, regeneration in the presence of carbon dioxide was not easily accomplished.</p><p>The findings of this thesis suggest that the bubbling fluidized bed reactor is an attractive reactor configuration for SE-SMR. Low gas throughput is the major disadvantage for this configuration, and operation in the fast fluidization regime is most likely to be preferred on an industrial scale of the process. Future work should focus on developing sorbents and catalysts that are suited for high velocity operation, with respect to reactivity and mechanical strength.</p>

A laboratory experiment and a numerical simulation of a dual well pair SAGD process with live bitumen were conducted to examine operating strategies on the recovery performance of a multiple well pair SAGD process. The experiment was successfully carried out under such operation strategies as injecting steam into one well pair while producing from both producers after chambers mergence to sweep the oil between the two well pairs. The experimental results showed high oil recovery from the transition region between the two well pairs with these operation strategies. Numerical simulation matched reasonably well experimental results, which indicated that the numerical model captured the key mechanisms of the dual well pairs experiment. The improved SAGD process behaviour and performance was demonstrated in terms of faster oil production, enhanced solution gas production, and accelerated adjacent chambers communication in the experimental and numerical studies. These operation strategies could be applied in the multiple well pairs SAGD and enhance SAGD performance after steam chambers merge between adjacent well pairs. / Petroleum Engineering

The continuous downscaling of CMOS technology presents advantagesand difficulties for IC design. While it allows faster, denser and more energy efficient digital circuits, it also imposes several challenges which limit the performance of analogue circuits. Concurrently, applications are continuously pushing the boundaries of power efficiency and throughput of electronic systems. Accordingly, IC design is increasingly shifting into highly digital systems with few necessary analogue components. Particularly, continuous-time (CT) sigma-delta (ΣΔ) analogue-to-digital converters (ADCs) have recently received a growing interest, covering high-resolution medium-speed requirementsor offering low power alternatives to low speed applications. However, there are still several aspects that deserve further investigation so as to enhancethe ADC’s performance and functionality. The objective of the research performed in this thesis is the investigation of digital enhancement solutions for CT ΣΔ ADCs. In particular, two aspects are considered in this work. First, highly digital techniques are investigated to minimize circuit impairments, with the objective of providing solutions with reduced analogue content. In this regard, a multi-bit CT ΣΔ modulator with reduced number of feedback levels is explored to minimize the use of linearisation techniques in the DAC. The proposed architecture is designed and validated through behavioural simulations targeting a mobile application. Additionally, a novel self-calibration technique, using test-signal injection and digital cancellation, is proposed to counteract process variations affecting single loop CT implementations. The effectiveness of the calibration technique is confirmed through corner simulations using behavioural models and shows that stability issues are minimized and that a 7 dB SNDR degradation can be avoided. The second aspect of this thesis investigates the use of high order CT modulators in incremental ΣΔ (IΣΔ) and extended-range IΣΔ ADCs, with the objective of offering low-power alternatives for low-speed high-resolution multi-channel applications. First, a 3rd order single loop CT IΣΔ ADC, targeting an 8-channel 500 Ksamples/sec rate per channel recording system for neuropotential sensors, is proposed, fabricated and tested. The proposed architecture lays the theoretical groundwork and demonstrates a competitive performance of high-order CT IΣΔ ADCs for low-power multi-channel applications. The ADC achieves 65.3 dB/64 dB SNR/SNDR and 68.2 dB dynamic range. The modulator consumes 96 μW from a 1.6 V power supply. Additionally, the use of extended range approach in CT IΣΔ ADCs is investigated,so as to reduce the required number of cycles per conversion while benefiting from the advantages of a CT implementation. The operation, influence of filter topology and impact of circuit non-idealities are first analysed using a general approach and later validated through a test-case. It was found that, by applying analogue-digital compensation in the digital domain, it is possible to minimize the noise leakage due to analogue-digital transfer function mismatches and benefit from relaxed amplifiers’ finite gain-bandwidth product and finite DC gain, allowing, as a consequence, a power conscious alternative. / QC 20120528

Nanotechnology plays an important role in today’s society because it allows convergence to the nanoscale, that is to say to the level of atoms and molecules, as part of a miniaturization trend; and also because it is being used for improving human performance or enhancement. Nanotechnology will have a tremendous impact thanks to its potentialities, and the human desire for enhancement - and for some even the desire to reach a posthuman stage. Since nanotechnology-based human applications – cyborgs and implants – might represent a threat to what defines us as humans, namely our human nature, a different approach on the distinction between therapy and enhancement is needed in order to handle those applications in a wiser and more responsible way. This thesis will work on such approach.

Ought we to enhance our cognitive capacities beyond the normal human range? There is no denying that it might be a good idea to level out differences between people with respect to cognitive capacities, and there is no denying that some persons' reaching beyond normal capacities may have some good side-effects on society at large (but also bad side-effects, of course). But is there any direct gain to be made by having ones cognitive capacities enhanced? Will this as such make our lives go better? No, I argue, or, at least, there doesn't seem to exist any evidence suggesting that it would. And it doesn't matter whether we consider the question from a narrow hedonistic perspective, from a more refined hedonistic perspective, from a desire-satisfaction view, or if we adopt some reasonable objective list view of what makes a life go well. Only on an extremely perfectionist — and implausible —view of what makes our lives go well could any direct value in cognitive enhancement find support. Finally, there are no good reasons to do with our sense of identity to enhance even our capacity to remember. So, cognitive enhancement as such would not make our lives go any better. / <p>Author count: 1</p>

Low resolution (LR) Grid Digital Elevation Models (DEMs) are the inputs of multi frame super resolution (MFSR) algorithm to obtain high resolution (HR) grid DEM. In digital image MFSR, non-redundant information carrying LR image pairs are a necessity. By using the analogy between digital image and grid DEMs, it is proven that, although the LR grid DEMs have a single source, they carry non-redundant information and they can be inputs of MFSR. Quality of grid DEM can be increased by using MFSR techniques. The level of spatial enhancement is directly related to the amount of non-redundant information that the LR grid DEM pairs carry. It is seen that super resolution techniques have potential to increase the accuracy of grid DEMs from a limited sampling.

The aim of the study was to describe how managers at the eldercare system especially in nursing homes work to ensure high quality care. For this purpose, a qualitative method was used in this study and four managers at nursing home have been interviewed. Previous studies have shown that managers in some cases are restricted in their actions and that this may slow down the improvement of the care. At the same time the managers describe their work as demanding and diverse. They have a significant staff responsibility, meaning that they have to ensure the quality of care.  In this study, some previous results have been confirmed for example that the managers feel that they have an impact on the quality of care, that managers value their contacts with staff, patients and relative highly and that their main purpose is the quality of care. The data was analyzed using one of many role theories and with different descriptions of leadership. The results show that the managers are working to ensure that the quality of the care is high by ensuring that the staff is competent, participating in development meetings, maintaining good contact with serval actors like staff, patients and relative, providing staff training courses and involving the staff in developing a more productive environment. Therefore, the managers have more impact on how good the quality of the care is than one might think.

The human sensory system processes many modalities simultaneously. It was believed that each modality would be processed individually first, and their combination deferred to higher-level cortical areas. Recent neurophysiological investigations indicate interconnections between early visual and auditory cortices, areas putatively considered unimodal, but the function remains unclear. The present work explores how this cross-modality might contribute to a visual enhancement of auditory performance, using a combined theoretical and experimental approach. The enhancement of sensory performance was studied through a signal detection framework. A model was constructed using principles from signal detection theory and neurophysiology, demonstrating enhancements of roughly 1.8dB both analytically and through simulation. Several experiments were conducted to observe e ects of visual cues on a 2-alternative-forced-choice detection task of an auditory tone in noise. Results of the main experiment showed an enhancement of 1.6dB. Better enhancement also tended to occur for more realistic relationships between audio to visual stimuli.

The world’s understanding of HIV/AIDS is grounded in biomedicine and shaped by cognitive psychology. Both biomedicine and cognitive psychology bonded with historically top-down development mechanisms to create ‘prevention’ strategies that obscured from vision the root causes of the pandemic. Within this hierarchy, bio-medicine and the cognitive psychological conception of human beings silenced indigenous voices and experiences of communities fighting HIV/AIDS. This is most certainly true in the case of Sub-Saharan Africa. This research explores the emergence of the Community Capacity Enhancement – Community Conversations prevention approach that places community dialogue, and the voices of communities, at the forefront of the battle to end HIV/AIDS and deconstruct and challenge the forms of structural violence that hold prevalence rates in their place. Within these spaces, oral traditions, indigenous knowledge, and resistance illustrate new and complex pictures of the viruses’ socio-economic impact and provide new foundations for community generated movements to curb the virus.