The present day duplex wall receptacle in the United States provides 120Vrms AC at 60Hz, which comes from a standard set for AC loads by the National Electrical Manufacturers Association. With a DC system, such as what is used in the DC House project currently being developed at Cal Poly, providing DC power to DC loads presents a technical challenge due to the different required DC operating voltages of the loads. This thesis entails the design and construction of a Smart DC/DC Wall Plug, which can automatically adjust its output voltage to match any required DC load voltages. In the DC House implementation, renewable energy sources generate power to feed a 48V DC Bus. The Smart DC/DC Wall Plug converts power from the 48V bus to the appropriate voltage and power levels needed by the DC loads. The Smart DC/DC Wall Plug relies on load current detection, and uses a 10-bit digital potentiometer and a programmable current DAC to adjust the feedback network, thereby changing the output voltage. A dual channel 100W PCB prototype utilizing a STMF302R8 microcontroller is implemented for this design while confining to the NEMA wall outlet form factor. Results of hardware test verify the functionality of the Smart DC/DC Wall Plug in producing the required DC load voltages. Technical issues during the development of the Smart DC/DC Wall Plug will be described, along with suggestions to further improve from the current design.

Student Number : 0102782D - MA research report - School of Geography, Archaeology and Environmental Studies - Faculty of Humanities / The South African environmental policies, NEMA (1998), and the White Paper on Environment and Development (1995) support the incorporation of environmental education into the national school curriculum. These policies propose that environmental education should be interdisciplinary and holistic in approach and should run across all school learning areas and disciplines. The policies further recognize the role of environmental education as a potential tool through which learners and the general public can engage themselves in critical issues related to environmental justice in South Africa. Interviews with teachers, government officials and Delta personnel show that the national policy initiatives, documents and projects have not yet reached schools in the Gauteng region. The triangulated findings from this research show that there is poor coordination between parties responsible for the implementation of policies. This poor coordination has resulted in teachers not being prepared and empowered to initiate, organise, implement and run environmental education in schools. As a result integrated environmental education is not being implemented across the curriculum in the schools that were interviewed in the study. The basic problem seems to be that teachers and school principals have poor understanding of the nature of environmental education. It appears, from the research findings, that this is linked to a lack of training and support.

A Positive Electron Tomography/Computed Tomography devise was installed in the X-ray section at US Linköping in May 2007. Positive Electron Tomography examinations with 18F-fluoro-deoxyglucose are mainly used for tumor examinations. During 2007 occurred approximately 200 examinations and in 2008 600 are planned.Today there are two reconstruction methods commercially available, Filtered Back projection and Maximum Likelihood Expectation Maximiza tion, used in the faster version called Ordered Subsets Expectation Maximization. The image quality in Positive Electron Tomography depends on the choice of reconstruction method and the settings of its parameters. We have performed a physical phantom study with Positive Electron Tomography to determine optimal parameters for the iterativereconstruction algorithm Ordered Subsets Expectation Maximization. To find out whether or not the quality of the image can be improved, so that the patient received radiation dose and/or examination time can be lowered. The phantom used was a NEMA IEC Body PhantomTM, designed to mimic small hot lesions typicalin 18F, Fluorine-18 PET, and all calculations were done according to the NEMA NU2-2001 protocol. The main conclusion from this project is that a higher level of contrastcan be reached, compared to the one clinically obtained today. Using more iterations then recommended from the manufacturer.

<p>A Positive Electron Tomography/Computed Tomography devise was installed in the X-ray section at US Linköping in May 2007. Positive Electron Tomography examinations with 18F-fluoro-deoxyglucose are mainly used for tumor examinations. During 2007 occurred approximately 200 examinations and in 2008 600 are planned.Today there are two reconstruction methods commercially available, Filtered Back projection and Maximum Likelihood Expectation Maximiza tion, used in the faster version called Ordered Subsets Expectation Maximization. The image quality in Positive Electron Tomography depends on the choice of reconstruction method and the settings of its parameters. We have performed a physical phantom study with Positive Electron Tomography to determine optimal parameters for the iterativereconstruction algorithm Ordered Subsets Expectation Maximization. To find out whether or not the quality of the image can be improved, so that the patient received radiation dose and/or examination time can be lowered. The phantom used was a NEMA IEC Body PhantomTM, designed to mimic small hot lesions typicalin 18F, Fluorine-18 PET, and all calculations were done according to the NEMA NU2-2001 protocol.</p><p>The main conclusion from this project is that a higher level of contrastcan be reached, compared to the one clinically obtained today. Using more iterations then recommended from the manufacturer.</p>

Heavy traffic volumes in peak hours accompanied by closely located signalized intersections and nearside bus stops on U.S. 1, result in congestion and traffic delays that bus transit may be able to alleviate to some extent. The capital investment and operating costs of other transit solutions such as "Bus Rapid Transit" and "Heavy Rail Transit" projects were found to be cost prohibitive compared to bus transit signal priority (TSP) options. Successful implementation of a limited TSP pilot project led local authorities to conclude that TSP should be extended to the full length of the Fairfax Connector bus routes on U.S. 1. This research focused on testing the impacts of a ten second green extension priority strategy for all the northbound transit buses in the morning peak period at twenty-six signalized intersections along U.S. 1. A micro simulation model VISSIM 3.7 was used to analyze the impacts of TSP. The simulation analysis indicates that the Fairfax Connector buses might benefit from the green extension strategy. Overall, improvements of up to 4% for transit travel time savings and 5-13% reduction in control delay for transit vehicles were observed. Considering all side street traffic, the total increase in maximum queue length might be up to 1.23%. Future research possibilities proposed include the evaluation of different priority strategies such as an early green, red truncation and queue jumps. Impacts of using a dedicated lane for transit buses along with TSP can also be evaluated. Conditional transit signal priority may also include bus occupancy levels and bus latenesses. / Master of Science

Introduction: Despite the relatively low dose (0.5 mSv – 1 mSv) generated by Attenuation Correction CT (ACCT) in PET examinations, the ALARA principle is still applicable. The currently used ACCT standard protocol at the Karolinska University Hospital in Solna uses 7.6 effective mAs (mAseff) and 120 kVp, but reducing mAseff and/or kVp would decrease patient dose as well as facilitate an increased number of research subjects. A CT reconstruction algorithm called Quantification Achieved Consistently (Q.AC.) (Lonn, 2012) has recently been developed to enable reduced doses from ACCT, while preserving quantitative PET data. The purposes of this study were to investigate possible limitations of the Q.AC. with respect to patient size, and to optimise protocols, aiming at minimising ACCT dose in terms of Volumetric Computer Tomography Dose Index CTDIvol. Methods: Measurements were performed with a GE PET/CT Discovery system, which offers Q.AC. reconstruction. The NEMA NU-2 protocol was followed to quantify PET quality, including evaluations of relative count error in the artificial lung in the phantom centre (lung), hot- and cold-sphere contrast (Q), and background variability (N). Two phantoms were used; the NEMA body phantom (elliptical cross section sized 30 cm laterally and 23 cm anterior-posterior (AP)), here representing paediatric patients and small-sized adults, and the same phantom with an additional (20 cm laterally and 4 cm AP) ellipsoid plastic (PMMA) extension ring, representing mid- and large-sized patients. ACCTs were acquired with 15 mAseff values, range [2.3 - 260], in combination with four kVp values [80, 100, 120, 140] and reconstructed with two algorithms (Q.AC. and a regular soft CT algorithm). Consequently, PET reconstructions were performed based on each mAseff, kVp and CT-reconstruction combination. Results: Quantitatively similar PET results to the standard protocol were achieved with the Q.AC. CT reconstruction algorithm using a CTDIvol = 0.06 mGy (2.3 mAseff and 80 kVp) for the NEMA body phantom, respectively a CTDIvol = 0.20 mGy (2.3 mAseff and 120 kVp) for the phantom with additional extension ring. Conclusions: This study indicates that the Q.AC. CT reconstruction algorithm enables accurate PET results at lower ACCT mAseff and kVp settings than the currently used clinical standard protocol. For paediatric patients and small-sized adults, a reduction of CTDIvol by approximately 90% may be achieved, while for mid- and large-sized patients, the CTDIvol can be reduced by approximately 70% without loss of quantitative PET data.

It is common-cause that South Africa can be regarded as a country that is rich in diversity of natural resources. Moreover, it is generally accepted that South Africa has the best legislation with regard to the regulation of the environment in various fields such as water, air, biodiversity and waste management. However, there is to date, no specific legislation regulating renewable energy in South Africa. As a result of the high unemployment rate, poverty and the rural population not having adequate access to electricity, these communities depend heavily on the traditional use of biomass, which refers to the direct combustion of wood, charcoal, leaves, agricultural residue, and animal/human waste for their basic energy needs, which include cooking, drying and charcoal production. The traditional use of biomass results in a host of detrimental side-effects such as environmental degradation and negative social impacts. The latter necessitates that the use of renewable energy sources will need to be regulated in terms of law and policy reflective of section 24 of the Constitution of the Republic of South-Africa, 1996. In terms of section 24 of the Constitution, the State must establish and implement reasonable legislative measures to promote sustainable development and the sustainable use of natural resources while providing for the protection of the environment for the benefit of present and future generations. It is immediately evident that the legislative measures mandated by section 24 of the Constitution should be geared towards the facilitation of environmental protection. Falling within the ambit of such legislative measures is framework legislation. An example of framework legislation is the National Environmental Management Act 107 of 1998 (the NEMA). In this dissertation an overview of the concept of framework legislation will be provided with specific reference to the NEMA and its role as such in South African environmental law. This will be followed by an analysis of existing South African renewable energy policy documents, during which norms and/or principles common to these documents will be identified. The question subsequently arises: What should be included in framework legislation aimed at regulating renewable energy in South Africa? These identified norms will be proposed as the general basic norms which should be included in renewable energy framework legislation aimed at regulating the supply of renewable energy in South Africa. / LLM (Environmental Law and Governance), North-West University, Potchefstroom Campus, 2015

It is common-cause that South Africa can be regarded as a country that is rich in diversity of natural resources. Moreover, it is generally accepted that South Africa has the best legislation with regard to the regulation of the environment in various fields such as water, air, biodiversity and waste management. However, there is to date, no specific legislation regulating renewable energy in South Africa. As a result of the high unemployment rate, poverty and the rural population not having adequate access to electricity, these communities depend heavily on the traditional use of biomass, which refers to the direct combustion of wood, charcoal, leaves, agricultural residue, and animal/human waste for their basic energy needs, which include cooking, drying and charcoal production. The traditional use of biomass results in a host of detrimental side-effects such as environmental degradation and negative social impacts. The latter necessitates that the use of renewable energy sources will need to be regulated in terms of law and policy reflective of section 24 of the Constitution of the Republic of South-Africa, 1996. In terms of section 24 of the Constitution, the State must establish and implement reasonable legislative measures to promote sustainable development and the sustainable use of natural resources while providing for the protection of the environment for the benefit of present and future generations. It is immediately evident that the legislative measures mandated by section 24 of the Constitution should be geared towards the facilitation of environmental protection. Falling within the ambit of such legislative measures is framework legislation. An example of framework legislation is the National Environmental Management Act 107 of 1998 (the NEMA). In this dissertation an overview of the concept of framework legislation will be provided with specific reference to the NEMA and its role as such in South African environmental law. This will be followed by an analysis of existing South African renewable energy policy documents, during which norms and/or principles common to these documents will be identified. The question subsequently arises: What should be included in framework legislation aimed at regulating renewable energy in South Africa? These identified norms will be proposed as the general basic norms which should be included in renewable energy framework legislation aimed at regulating the supply of renewable energy in South Africa. / LLM (Environmental Law and Governance), North-West University, Potchefstroom Campus, 2015

Background: PET nuclides can have a considerable influence on the spatial resolution and image quality of PET/CT scans, which can influence diagnostics in oncology, for example. The individual impact of the positron energy of ¹⁸F, ⁶⁸Ga, and ⁶⁴Cu on spatial resolution and image quality was compared for PET/CT scans acquired using a clinical, digital scanner. - Methods: A Jaszczak phantom and a NEMA PET body phantom were filled with ¹⁸F-FDG, ⁶⁸Ga-HCl, or ⁶⁴Cu-HCl, and PET/CT scans were performed on a Siemens Biograph Vision. Acquired images were analyzed regarding spatial resolution and image quality (recovery coefficients (RC), coefficient of variation within the background, contrast recovery coefficient (CRC), contrast–noise ratio (CNR), and relative count error in the lung insert). Data were compared between scans with different nuclides.- Results: We found that image quality was comparable between ¹⁸F-FDG and ⁶⁴Cu-HCl PET/CT measurements featuring similar maximal endpoint energies of the positrons. In comparison, RC, CRC, and CNR were degraded in ⁶⁸Ga-HCl data despite similar count rates. In particular, the two smallest spheres of 10 mm and 13 mm diameter revealed lower RC, CRC, and CNR values. The spatial resolution was similar between ¹⁸F-FDG and ⁶⁴Cu-HCl but up to 18% and 23% worse compared with PET/CT images of the NEMA PET body phantom filled with ⁶⁸Ga-HCl. - Conclusions: The positron energy of the PET nuclide influences the spatial resolution and image quality of a digital PET/CT scan. The image quality and spatial resolution of ⁶⁸Ga-HCl PET/CT images were worse than those of ¹⁸F-FDG or ⁶⁴Cu-HCl despite similar count rates.

Magister Legum - LLM