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1
Zhang, Di. "Analysis and Design of Paralleled Three-Phase Voltage Source Converters with Interleaving." Diss., Virginia Tech, 2010. http://hdl.handle.net/10919/27579.
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Three-phase voltage source converters(VSCs) have become the converter of choice in many ac medium and high power applications due to their many advantages, including low harmonics, high power factor, and high efficiency. Modular VSCs have also been a popular choice as building blocks to achieve even higher power, primarily through converter paralleling. In addition to high power ratings, paralleling converters can also provide system redundancy through the so-called (N+1) configuration for improved availability, as well as allow easy implementation of converter power management. Interleaving can further improve the benefit of paralleling VSCs by reducing system harmonic currents, which potentially can increase system power density. There are many challenges to implement interleaving in paralleled VSCs system due to the complicated relationships in a three-phase power converter system. In addition, to maximize the benefit of interleaving, current knowledge of symmetric interleaving is not enough. More insightful understanding of this PWM technology is necessary before implement interleaving in a real paralleled VSCs system.
In this dissertation, a systematic methodology to analyze and design a paralleled three-phase voltage source converters with interleaving is developed. All the analysis and proposed control methods are investigated with the goal of maximizing the benefit of interleaving based on system requirement.
The dissertation is divided into five sections. Firstly, a complete analysis studying the impact of interleaving on harmonic currents in ac and dc side passive components for paralleled VSCs is presented. The analysis performed considers the effects of modulation index, pulse-width-modulation (PWM) schemes, interleaving angle and displacement angle. Based on the analysis the method to optimize interleaving angle is proposed. Secondly, the control methods for the common mode (CM) circulating current of paralleled three-phase VSCs with discontinuous space-vector modulation (DPWM) and interleaving are proposed. With the control methods, DPWM and interleaving, which is a desirable combination, but not considered possible, can be implemented together. In addition, the total flux of integrated inter-phase inductor to limit circulating current can be minimized. Thirdly, a 15 kW three phase ac-dc rectifier is built with SiC devices. With the technologies presented in this dissertation, the specific power density can be pushed more than 2kW/lb. Fourthly, the converter system with low switching frequency is studied. Special issues such as beat phenomenon and system unbalance due to non-triplen carrier ratio is explained and solved by control methods. Other than that, an improved asymmetric space vector modulation is proposed, which can significantly reduce output current total harmonic distortion (THD) for single and interleaved VSCs system. Finally, the method to protect a system with paralleled VSCs under the occurrence of internal faults is studied. After the internal fault is detected and isolated, the paralleled VSCs system can continue work. So system reliability can be increased.Ph. D.
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Jihad, Hamza El. "Contribution à l'étude des convertisseurs multi-niveaux moyenne tension : réduction d'harmoniques BF et linéarisation de leur tension." Electronic Thesis or Diss., Université de Lorraine, 2019. http://www.theses.fr/2019LORR0175.
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Cette thèse traite des convertisseurs de puissance multi-niveaux destinés aux applications d’entraînements électriques, utilisés notamment dans le domaine de l’Oil & Gas et de la propulsion marine, ou bien aux applications réseaux comme la compensation de l’énergie réactive. L’objectif est l’optimisation des commandes de ces convertisseurs de façon à réduire le contenu harmonique de la tension de sortie et donc du courant, paramètre très important pour le dimensionnement à la fois des filtres de sortie et des machines électriques qui y sont connectées. Dans la première partie de ce mémoire, les différentes topologies multi-niveaux sont analysées et trois topologies cinq niveaux retenues sont comparées en termes de nombre de composants semi-conducteurs, des pertes, du contenu harmonique et de l’énergie stockée dans les éléments passifs. Selon le type de l’application, l’une d’entre elles est préférée aux autres. En deuxième partie, nous avons proposé une méthode de réduction d’harmoniques basse fréquence qui consiste à maîtriser la phase des porteuses MLI pour des ratios entiers des fréquences de découpage et du fondamentale de la tension de référence. La minimisation des harmoniques basse fréquence de la tension de sortie du convertisseur par l’optimisation de la phase des porteuses est validée d’abord par des simulations numériques puis implémentée pratiquement et validée à l’aide d’un simulateur temps réel RT-Lab. Pour pallier aux problèmes de non-linéarités introduites par les méthodes classiques de ”clamping” des tensions de références des convertisseurs multi-niveaux, limitant l’amplitude de la tension de sortie maximale atteignable, nous proposons une nouvelle méthode de linéarisation en dernière partie de ce mémoire. Il s’agit d’ajouter une composante homopolaire optimisée aux tensions de références des convertisseurs multi-niveaux pour linéariser le fondamental de leurs tensions de sortie, ce qui permet d’accroître le maximum de leur amplitude. Cette méthode est testée par simulation numérique dans la commande d’un système d’entraînement électrique complet lui permettant de fonctionner sur toute la plage de vitesse, sans affecter l’équilibrage des tensions des capacités du bus continu principalThis thesis deals with multi-level power converters for electrical drive applications, used in particular in the field of Oil & Gas and marine propulsion, or for network applications such as reactive energy compensation. The objective is to optimize the controls of these converters in order to reduce the harmonic content of the output voltage and therefore of the current, a very important parameter for the sizing of both the output filters and the electrical machines connected to them. In the first part of this thesis, the different multi-level topologies are analyzed and three selected five-level topologies are compared in terms of the number of semiconductor components, losses, harmonic content and the energy stored in the passive elements. Depending on the application type, one of them is preferred over the others. In the second part, we proposed a method for reducing low frequency harmonics of the multilevel converter output voltage, which consists in controlling the phase of the PWM carriers for integer ratios of the switching frequency and the fundamental frequency. The minimization of low-frequency harmonics of the converter output voltage by optimizing the carrier phase is first validated by numerical simulations and then practically implemented and validated using a real time simulator RT-Lab. To overcome the problems of non-linearities introduced by the classical clamping methods of the reference voltages of multi-level converters, limiting the amplitude of the maximum achievable output voltage, we propose a new linearization method in the last part of this thesis. This involves adding an optimized zero-sequence component to the reference voltages of multi-level converters to linearize the fundamental of their output voltages, which makes it possible to increase their amplitude to its maximum achievable value. This method is tested by numerical simulation in the control of a complete electric drive system allowing it to operate over the entire speed range, without affecting the voltage balancing of the main DC bus capacitors
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Vamulapalli, Harika Rao. "On Dimensionality Reduction of Data." ScholarWorks@UNO, 2010. http://scholarworks.uno.edu/td/1211.
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Random projection method is one of the important tools for the dimensionality reduction of data which can be made efficient with strong error guarantees. In this thesis, we focus on linear transforms of high dimensional data to the low dimensional space satisfying the Johnson-Lindenstrauss lemma. In addition, we also prove some theoretical results relating to the projections that are of interest when applying them in practical applications. We show how the technique can be applied to synthetic data with probabilistic guarantee on the pairwise distance. The connection between dimensionality reduction and compressed sensing is also discussed.
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Khan, Wajid. "Energy reduction in the pultrusion and the rotational moulding processes." Thesis, University of Manchester, 2010. https://www.research.manchester.ac.uk/portal/en/theses/energy-reduction-in-the-pultrusion-and-the-rotational-moulding-processes(39f3af53-a68a-4f35-8543-3aba13ec6fca).html.
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This work embraces two different manufacturing processes: pultrusion androtational moulding. One (pultrusion) is concerned with manufacture with athermosetting composite while the other is concerned with manufacture of anunfilled thermoplastic. The connecting theme is one of energy usage in manufacturewith these processes. While a large number of comprehensive computer models of pultrusion havebeen generated, most are focussed on the prediction of the temperature andconversion distributions within the profile; by contrast, the analysis presented here isdirected towards the prediction of the duty cycle of the mould heaters as a first stepin recognising the significance of the energy consumed in the process. The results ofthe model are compared with experimental measurements of the duty cycle of anindustrial machine. The nature of this particular investigation was predominantlyapplied and in particular directed towards industrial use. For this reason, the modelwas created in MATLAB, a software package which is relatively more accessible tothe reinforced plastics industry than FE packages. The project involved extensivemodelling and experimentation. It is shown that the line speed could be increased significantly by preheatingthe profile before it enters the die. For example, line speed for one particular profilewas increased from 0.4m/min to 0.5 m/min by using a pre-heater set at 80°C. Thiswork also showed that the specific energy consumption of the process was 0.2kWh/kg to 0.3 kWh/kg; under different line speeds and operating conditions. Thiswas achieved by measuring the duty cycle of the heaters on the die. This increase inline speed means a saving of up to 30 % of the specific energy consumption in thepultrusion. The energy theme continues through the work on rotational moulding. It isshown that the specific energy consumption in rotational moulding can be reducedby up to 70% by direct heating of the mould by using electrical resistance heatersinstead of current method of using hot air to heat the mould. The finite elementmodel showed that this alternative heating method is capable of producing asuniform a heat distribution on the surface of the mould as the current heating systemby using cyclic heating.
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Gordon, Keith. "MACT Implementation at an Organic Chemical Manufacturing Facility: Human Health Risk Reduction." ScholarWorks@UNO, 2010. http://scholarworks.uno.edu/td/1222.
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Human health risk assessments are used by environmental regulatory agencies to determine risk from Hazardous Air Pollutants (HAPs). In this study, the Human Exposure Model (HEM-3) was used to compare the cancer and non-cancer inhalation health effects of a single organic chemical manufacturing facility in Geismar, Louisiana prior to and after Maximum Achievable Control Technologies (MACT) were implemented. The results indicate significant reductions in both cancer risk and non-cancer hazards. The analysis also indicated that the equivalent cancer risk reduction could have been achieved by addressing MACT in only one production process and one single pollutant (ethylene dichloride) within that process. This demonstrates the value that these risk assessments have at evaluating emissions at the facility level, and how they could be used in the control strategy decision making process.
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Balachandran, Nandu. "Utilization of Distributed Generation in Power System Peak Hour Load Shedding Reduction." ScholarWorks@UNO, 2016. http://scholarworks.uno.edu/td/2124.
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An approach to utilize Distributed Generation (DG) to minimize the total load shedding by analyzing the power system in Transactive energy framework is proposed. An algorithm to optimize power system in forward and spot markets to maximize an electric utility’s profit by optimizing purchase of power from DG is developed. The proposed algorithm is a multi-objective optimization with the main objective to maximize a utility’s profit by minimizing overall cost of production, load shedding, and purchase of power from distributed generators. This work also proposes a method to price power in forward and spot markets using existing LMP techniques. Transactive accounting has been performed to quantify the consumer payments in both markets. The algorithm is tested in two test systems; a 6-bus system and modified IEEE 14-bus system. The results show that by investing in DG, utility benefits from profit increase, load shedding reduction, and transmission line loading improvement.
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Williamson, Edwin Ferebee. "A comparison of the post-Cold War Defense budget reduction to prior post-conflict reductions after World War II, Korea and Vietnam." Thesis, Monterey, California. Naval Postgraduate School, 1993. http://hdl.handle.net/10945/40012.
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Approved for public release; distribution is unlimited.This thesis compares the current drawdown in defense budgets to those which occurred after World War II, Korea and Vietnam. Bach post-conflict period is examined with respect to the Department of Defense and Department of the Navy, comparing the degree and rate of reductions in budgets, manning and ships. There are three principle conclusions drawn from the research. First, that President Eisenhower was uniquely successful among post-conflict Presidents in maintaining the balance between force levels and funding during post-conflict drawdowns. Second, that the post-Vietnam 'hollow forces' occurred when funding was insufficient in the face of inflation to sustain the change to the all volunteer force. Third, that early signs in the current reduction point to the possibility of similar difficulties in balancing reductions in forces and budgets.
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Sutton, Patrick James. "The dimensional-reduction anomaly." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp02/NQ59681.pdf.
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Satter, Kurt. "Competitive Usability Studies of Virtual Environments for Shipbuilding." ScholarWorks@UNO, 2006. http://scholarworks.uno.edu/td/331.
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Establishing usability specifications as measurable attributes in repeatable scenarios has been an essential task in the management and continuous improvement processes [1]. Early studies in Usability Analysis were primarily conducted to assist software developers and hardware designers in improving the Human- Computer Interface (HCI) or Man- Machine Interface (MMI). However, this study was conducted to provide comparative data supporting broad conclusions regarding the comparative merits of one technology (nonstereoscopic, conventional CAD systems) competed against another (tracked, stereoscopic virtual environments). Competing environments to establish usability features and preferences provides a new tool to the interface designer. Benchmark scenarios were designed and executed to measure navigation, fault identification/repair, and spatial awareness through a sequence of choices and to provide user preference of one GUI paradigm over another functionally similar paradigm. This study, performed on a ship design application, included an analysis of the effects of user collaboration in virtual environments.
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Khalil, Mostafa Khalil. "The contribution of Islamic-based CSOs to poverty reduction in Egypt : the mechanisms, the politics and the lessons." Thesis, University of Manchester, 2014. https://www.research.manchester.ac.uk/portal/en/theses/the-contribution-of-islamicbased-csos-to-poverty-reduction-in-egypt-the-mechanisms-the-politics-and-the-lessons(85b282bf-6129-460a-9a6c-a0ea6083a55e).html.
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This thesis provides a critical analysis of how Islamic-based Civil Society Organisations (IBCSOs) contribute to poverty reduction in Egypt, through a qualitative study of four Civil Society Organisations (CSOs). The thesis closely examines case study IBCSOs’ organisational structures, their activities and the values that shape their conceptualisation of poverty. It reveals the similarities between IBCSOs’ poverty reduction work and official social protection, and discusses how their approaches to poverty reduction can be understood in terms of the various discourses justifying social protection (risks, rights and needs). The thesis also uses these case studies to examine the validity of Faith-Based Organisations (FBOs) as vehicles for poverty reduction and social protection. Finally, it discusses the relationship between these organisations’ poverty reduction activities and political mobilisation through an examination of the role they played in the recent political rise of the Islamist movement in Egypt, as well as the impact of recent political developments on their operations. A key purpose of this critical investigation of IBCSOs' approaches to poverty reduction is to explore more broadly their wider implications for development theory and practice by assessing whether they can contribute to existing knowledge on the means of civil society’s contribution to poverty reduction and development.
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Siriwatcharapiboon, Wilai. "The electrochemistry of metal nanoparticles for oxygen reduction and nitrate/nitrite reduction." Thesis, University of Birmingham, 2013. http://etheses.bham.ac.uk//id/eprint/4475/.
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This research has scientific aims focused on two important electrochemical reactions: oxygen reduction and nitrate/nitrite reduction. A series of rhodium (Rh) deposited on gold nanorods (Au NRs) and gold nanoparticles (Au NPs) were synthesised by wet chemical reduction. The scanning transmission electron microscopy (STEM) showed that Rh has a preferential deposition and epitaxial growth at the end of Au NRs. Cyclic voltammetry and rotating disc electrode (RDE) measurements were performed to study the oxygen reduction at these Au:Rh/C catalysts. Pyrolysed cobalt triethylenetetraamine on a carbon substrate (Co/TET A/C) was employed to produce H20 2 from the ORR. The results from the rotating ring disc electrode (RRDE) reveal that the heat treatment influences the H20 2 selectivity. The Co/TETA/C heated at 1000 oc yields the highest H20 2 selectivity while the Co/TETA/C heated at 700 oc yields the lowest H20 2 selectivity. Rh/C, Au:Rh/C nanoparticles and Sn modified Rh/C nanoparticles were employed for nitrate/nitrite reduction in acidic media. Results from on-line electrochemical mass spectrometry (OLEMS) reveal that the modified electrode generates N2 from further reduction of the nitrous oxide (N20) intermediate. Ion chromatography (IC) shows that ammonium is the main product at Rh/C. Hydroxylamine can also be detected after Sn modification on Rh/C.
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Workman, James C., and Ricky L. Williamson. "Budget reduction in the Navy." Thesis, Monterey, California: Naval Postgraduate School, 1990. http://hdl.handle.net/10945/27706.
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Approved for public release; distribution is unlimited.This thesis attempts to document and analyze budget and program reductions made by the Navy for fiscal years 1990, 1991 and beyond. Current and historical budget data were obtained from the Office of the Secretary of Defense, the Office of the Chief of Naval Operations and the Comptroller of the Navy and organized to permit analysis of budget trends employing several models of cutback budgeting. The thesis examines the following budgetary issues: (1) the trends and impact of budget cuts on DODDON appropriation accounts; (2) projected DODDON budget alternatives for FY 1992 through FY 1997; (3) the effect budget reductions have on the DODDON budgeting relative to criteria developed from two theoretical models of fiscal reduction methodology.
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Assafiri, T. I. "The electrochemical reduction of gases." Thesis, University of Newcastle Upon Tyne, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.370620.
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Sherratt, Anna. "The prospects for modal reduction." Thesis, University of Sheffield, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.269432.
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Workman, James C. Williamson Ricky L. "Budget reduction in the Navy." Monterey, California : Naval Postgraduate School, 1990. http://handle.dtic.mil/100.2/ADA243566.
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Thesis (M.S. in Management)--Naval Postgraduate School, December 1990.Thesis Advisor(s): Jones, Lawrence R. Second Reader: McCaffery, Martin J. "December 1990." Description based on title screen as viewed on April 1, 2010. DTIC Descriptor(s): Impact, Theory, Budgets, Reduction, Patterns, Naval Operations, Models, Theses. DTIC Identifier(s): Naval Budgets, Public Administration, Trends, Appropriations, Reductions, Department Of Defense, Theses. Author(s) subject terms: Budget Reduction, Appropriation Analysis. Includes bibliographical references (p. 91-95). Also available in print.
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Thomas, Stephen P. "The pragmatics of closure reduction." Thesis, University of Kent, 1993. https://kar.kent.ac.uk/21100/.
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Studley, John Richard. "The asymmetric reduction of ketones." Thesis, University of Bath, 1996. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.307117.
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Oliver, Tracy E. "Effectiveness of stigma reduction strategies for the mentally ill." Scholarly Commons, 2007. https://scholarlycommons.pacific.edu/uop_etds/654.
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Prior research has indicated that public stigma towards individuals diagnosed with mental illness may be reduced by exposing individuals to the truths about mental illness and by exposing individuals to a mentally ill person who by society's standards is a productive functioning adult. This study detemined whether the conditions shown to be effective for the public may, in turn, decrease the extent to which individuals diagnosed with mental illness stigmatizes themselves. Four conditions (education alone, contact alone, education-contact, control) were used to determine which method was more effective in reducing the effects of stigma. Stigma was measured using the Internalized Stigma of Mental Illness total and subscale scores and Devaluation-Discrimination Scale which were administered before the treatment session (pre), at the end of the treatment session (post), and at a 2-week follow-up. Conducting 4 (condition) X 3 (time) ANOVAs showed no significant results for any measure. Due to low power from poor participation-in-the-2--week-follow-up, 4 x 2 mixed_factorial ANOVA's were conducted without the follow-up data. The ISMI and Devaluation-Discrimination scores for each condition differed significantly for pre/post scores but not for conditions, with no significant interactions.
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Fichera, Dawn Marie. "Media richness, uncertainty reduction, and anticipated future interaction on social media sites." Click here for download, 2009. http://proquest.umi.com/pqdweb?did=1851422511&sid=1&Fmt=2&clientId=3260&RQT=309&VName=PQD.
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Marshall, Richard. "An appraisal of the Poverty Reduction Strategy (PRS) Initiative." Thesis, University of Manchester, 2010. https://www.research.manchester.ac.uk/portal/en/theses/an-appraisal-of-the-poverty-reduction-strategy-prs-initiative(3e0a4f9b-8f33-4dec-a15f-d49374cb0561).html.
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In late 1999, the World Bank and International Monetary Fund (IMF) jointly launched the Poverty Reduction Strategy (PRS) Initiative, under which low income countries (LICs) would be supported to develop multi-sectoral economic and social development plans. As such, these national PRSs would serve as the effective policy conditionality for concessional lending and the allocation of debt relief. Heralded by many as path breaking, the Initiative refocused attention on the role of the State and identified poverty reduction, as opposed to growth alone, as the primary goal of policy. However, from the outset, PRSs have been controversial. The most trenchant critics have described these plans as merely re-formulated structural adjustment packages. Other, more considered accounts, have questioned whether PRSs’ are capable of overcoming the agency problems inherent to donor-recipient relationships, and their ability to succeed in the weak policy environment typified by most LICs.In spite of the passage of some ten years, a rigorous evaluation of performance has yet to be published. This thesis aims to provide such an appraisal drawing on both quantitative and qualitative evidence. It employs cross-sectional statistical and econometric methods to examine poverty, growth and inequality outcomes based on a specially constructed dataset; and two detailed analytical case studies (for Mongolia and Vietnam) to probe the causal processes.Although some aggregate evidence is found of performance gains (relating to both poverty reduction and growth), these effects are partial and statistically fragile. Moreover, while no direct evidence is found of dis-inflationary policy biases, it is possible to detect a new narrowness within PRS policymaking. This reflects an orthodox policy consensus which favours growth over distributional improvements and places emphasis on a managed liberalization process. Additionally, it proved very difficult to find a causal link been PRS adoption and beneficial outcomes. The case study materials underline the pivotal role played by the IFIs in the design and management of PRSs, and their transitory and limited impact on actual national policy responses. Conclusions support many of the propositions put by the critical literature, and find that PRSs are poorly adapted to local institutional frameworks and neglect national political economies. As a result, their substance and longer term effectiveness is in doubt.
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Mace, Laura H. "Developing the partial reduction of pyridines." Thesis, University of Oxford, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.398101.
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Irvine, J. T. S. "The photoelectrochemical reduction of carbon dioxide." Thesis, University of Ulster, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.378753.
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Sandström, Martin. "Reduction Mechanics of The Cosmological Constant." Thesis, Uppsala universitet, Teoretisk fysik, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-340233.
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The quantum creation of membranes by a totally antisymmetric tensor and gravitational fields is considered in arbitrary space-time dimensions. The creation process is described by instanton tunneling. As membranes are created, the energy density associated with the antisymmetric field decreases, reducing the effective cosmological constant to a lower value. For a collection of parameters and initial conditions, the creation mechanism goes to a halt as soon as the cosmological constant is near zero. A brief exploration of a canonical gravity representation is also considered, where the system of ADM-composition in arbitrary space-time dimensions is introduced.Kvantprocessen av membranskapelse via en total anti-symmetrisk tensor och gravitationsfält är betänkt i arbiträra rumstidsdimensioner. Skapelseprocessen är beskriven via instantontunnling. Då membranen är skapade, reduceras värdet på energidensiteten som är associerad med det anti-symmetriska fältet. För en samling av parametrar och begynnelsevärden, stannar skapelseprocessen upp så fort den kosmologiska konstanten har ett värde nära noll. En kort utforskning av kanonisk gravitation är också betänkt, där ett system i termer av ADM-dekomposition i arbiträra rumstidsdimensioner är introducerat.
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Yang, Haoyuan, and Qian Zhang. "How Effective is the Kyoto Protocol in Impelling Emission Reduction." Thesis, Internationella Handelshögskolan, Högskolan i Jönköping, IHH, Economics, Finance and Statistics, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:hj:diva-15762.
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The Kyoto Protocol is one of the most important international climate change treaties aimed at fighting global warming. On January 1st 2005, the protocol was enforced with its first commitment period 2008-2012. However, the effectiveness of reducing CO2 emission has long been debated. The purpose of this thesis is to empirically as-sess the impact of the Kyoto Protocol on carbon dioxide reduction across countries, whether the protocol led significant difference after entering force in 2005. The data used in this thesis cover 37 Annex B countries and 148 non-annex B countries from 1990 to 2007. The models are constructed on the basis of the various contributing fac-tors to CO2 emissions and the Environmental Kuznets Curve model. The main find-ing is contrary against the result expected. The insignificant dummy variable cannot indicate that there is a “structural break” of CO2 emissions reduction after the Kyoto Protocol was implemented. The conclusion is that political agreements such as Kyoto Protocol cannot show critical effects on reducing carbon dioxide. The underlying main driving factors of CO2 emission are energy use, electricity from coal source, fossil fuel burning, in other words, industrialization. And the technology develop-ments cannot keep in pace with finding a new energy source and effectively control-ling CO2 emissions in the short run.
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Phillips, Kristina T. "Applying the Relapse Model to Harm Reduction: The Development and Evaluation of the Harm Reduction Self-Efficacy Questionnaire." Connect to this title online, 2005. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=bgsu1131342662.
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Dongchen, Wang. "Effect of Density on the Reduction of Fe2O3 Pellets by H2-CO Mixtures." Thesis, KTH, Materialvetenskap, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-100933.
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This study aims to find how density affects the reduction extent and reduction rate. H2-CO gas mixture is used as reducing agent. Five groups of different density pellets were reduced at four different temperatures. Light optical microscope (LOM) and scanning electron microscope with energy dispersive X-ray spectroscopy (SEM-EDS) used to detect completely and partially reduced pellets to investigate how density affects the reduction mechanisms. Results illustrate that density affects reduction extent and reduction rate a lot. However, when reaction temperature is 1123 K, density has less influenc on reduction extent. The carbon deposition occurred for high density pellets at 973 K and 1023 K. The reduction process cannot be described by a single rate controlling step. Reduced layer is denser compared with unreduced layer. Reaction at initial stages goes much faster than later stages.
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Chávez, José, Fernando Osorio, Ernesto Altamirano, Carlos Raymundo, and Francisco Dominguez. "Lean production management model for SME waste reduction in the processed food sector in Peru." Springer, 2019. http://hdl.handle.net/10757/656241.
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El texto completo de este trabajo no está disponible en el Repositorio Académico UPC por restricciones de la casa editorial donde ha sido publicado.The reduction of waste is a constant concern for companies that form part of a supply chain. In industrial processors, these are related to logistics solutions, because the production process of the different products is highly automated. In the case of the Peruvian potato, this model is not applicable due to its irregular characteristics. In this context, this paper proposes an improvement in the process of elaboration of processed potatoes in order to reduce or eliminate waste in food sector companies. Identification tools are used for activities that do not generate value, such as the VSM, and other continuous improvement tools such as Kaizen and 5S, as well as a simulation model. In the validation, an 89% increase in the product yield, as well as a 72% efficiency increase, is obtained.
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Delaney, Joseph Peter. "The effects of stress and relaxation on heart rate variability in health and disease." Thesis, University of Liverpool, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.250354.
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Maartens, Yolanda. "Development communication in disaster risk reduction : the G.I.R.R.L. (Girls in risk reduction leadership) project / Maartens Y." Thesis, North-West University, 2011. http://hdl.handle.net/10394/7627.
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South African informal settlement communities are faced with infrastructural
cha llenges such as a lack of proper housing, poor sanitation, poor electrical
connections, if any, poor medical facilities and various social health risks such as
HIV/Aids, TB and other STDs, as well as high levels of violence and crime. Young girls
form a portion of the demographics of such informal settlements. Most adolescent
girls, between the ages of 13 and 18 years are at an increased risk merely because
they are physica lly smaller than their male peers, are able to become pregnant and
have to compete with multiple siblings and family members. Most of these young
girls have to leave school to act as heads of households, to provide an income or
because they have become pregnant. These factors form the crux of disaster risk
reduction initiatives as such initiatives focus on bui lding up the resiliency of those
who are most vulnerable in society.
This study focuses on the aspects of disaster risk, risk reduction and communitybased
disaster risk awareness. The study is unique in that combines the fie lds of
development communicat ion and disaster risk reduction and the principles of
participative development communication form the guidelines throughout the
study. The purpose of the study is to determine whether the inclusion of
development communication principles could increase stakeholder involvement and
whether development communication could address the gaps that have been
identified within the G. I.R.R.l. Programme as a community-based disaster risk
reduction initiative. This community-based initiative is known as the Girls In Risk
Reduction Leadership (G. I.R.R.l.) Project and was designed to implement within a
disaster risk reduction capacity. Focus groups were held with the participants of the
G.I.R.R.l. Project and semi-structured interviews were held with the project team.
The results of the research indicate the importance of baseline research before
implanting a community-based disaster risk reduction initiative. The findings
support the principles of development communication within disaster risk reduct ion
and are applied to the G.I.R.R.L. Programme and the respective limitations that were
identified by the research.
The study highlights the importance of participat ion in community-based disaster
risk reduction in it iat ives and places young adolescent girls in the spotlight.
Development communication is an important aspect to consider and this study
outlines its ro le in the disaster risk reduction environment.Thesis (M. Development and Management)--North-West University, Potchefstroom Campus, 2011.
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Foreman, Anne M. "Negative reinforcement by timeout from avoidance the roles of shock-frequency reduction and response-effort reduction /." Morgantown, W. Va. : [West Virginia University Libraries], 2009. http://hdl.handle.net/10450/10343.
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Thesis (M.S.)--West Virginia University, 2009.Title from document title page. Document formatted into pages; contains vi, 32 p. : ill. Includes abstract. Includes bibliographical references (p. 30-32).
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Sandmeier-Marquardt, Bridget. "Patients' self-concept, desire for information and uncertainty reduction : a thesis." Scholarly Commons, 2001. https://scholarlycommons.pacific.edu/uop_etds/542.
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This is a post-test only experimental design using an uncertainty reduction video to alleviate patient uncertainty, desire for information and increase self-concept to improve overall patient satisfaction with health care experience. The subjects were 80 cardiac consultation patients in a cardiology clinic in Northern California.
Forty people were randomly assigned to a control group and forty people to the experimental group. A scale was given to each group which measured the patients' level of self-concept, level of uncertainties (medical setting, relational and illness), and desire for information. The experimental group received an uncertainty reduction video prior to filling out the questionnaire. The uncertainty reduction video was designed to debrief the patient on subjects that may be causing uncertainty for the patient.
In conclusion, this study found that the uncertainty reduction video significantly reduced the patient's level of medical setting uncertainty. The study showed a relationship between medical setting uncertainty and relational uncertainty and a relationship between relational uncertainty and illness uncertainty. The study also indicated that patients have high levels of uncertainties in all uncertainty areas: illness, relational, and medical setting, and high a desire for information. However, the video did not show an ability to reduce a patient's level of relational or illness uncertainty. The study also did not show a relationship between self-concept and level of uncertainty and desire for information.
Future areas of research suggest that for a similar study a series of illness specific videotapes may be more beneficial at reducing illness uncertainty. The patient's level of previous knowledge, its source, depth and credibility was also suggested for future research. Another area suggested for future research would be the correlation between uncertainties and anxieties.
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Turner, Stephen Keith. "The synthetic utility of the sila-Birch reduction." Thesis, University of Leeds, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.277662.
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Sydnes, Lars. "Geometric reduction and the three body problem." Doctoral thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for matematiske fag, 2012. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-17522.
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This dissertation investigates a particular reduction of the three body problem, using a combination of Riemannian geometry and geometric invariant theory of three body motions in Euclidean space. Our point of departure is the reduction that is described in [HS07]. Here, we present this reduction from a new point of view. This viewpoint emphasizes the flexibility in the choice of geometric invariants of three body motions, within one particular class of systems of invariants. Many of our important calculations are based on the singular value decomposition of matrices, and we show that the flexibility of the geometric invariants is strongly related to the flexibility of the singular value decomposition. In addition, we go some steps further than [HS07]: In the context of the three dimensional three body problem, we calculate the reduced equations of motion in terms of our chosen system of invariants. The rotational part of this reduction is extended to the general case of many particle systems evolving in three dimensional space. We also include a large discussion on the conformal geometry of the shape invariants of the three body problem.
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Freestone, Graeme. "Investigating the partial reduction of aromatic heterocycles." Thesis, University of Oxford, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.410561.
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Kapoor, Radhicka. "Essays on the macroeconomics of poverty reduction." Thesis, London School of Economics and Political Science (University of London), 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.551103.
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Poverty remains one of the most pressing issues of our time. Understanding the impact of macroeconomic policy on poverty through growth and distribution of income is of considerable interest and this is what I examine in this dissertation. In Chapter 1, 'The Arithmetic of the Poverty-Growth- Inequality Triangle-Evidence from States of India', I use an arithmetic approach to examine how growth and income distribution matter simultaneously to poverty reduction by separating changes in poverty into a growth and distribution component. The results indicate that the poor benefit more from increasing aggregate growth than reducing inequality. In fact, bulk of the poverty reduction is concentrated in a period which witnessed the steepest increase in inequality since the effect of growth on poverty was large enough to overturn the effect of adverse distributional changes. Also, there is a great deal of heterogeneity in the poverty reduction performances of states, in particular the growth elasticity of poverty. I examine this heterogeneity in Chapter 2, 'The Empirics of the Poverty-Growth-Inequality Triangle: Does High Initial Poverty Matter?- Evidence from Rural India'. The more equal the initial income distribution and the higher the initial level of development, the greater is the growth elasticity of poverty. This empirical analysis also examines the impact of initial poverty on the pace of poverty reduction via its impact on economic growth and growth elasticity of poverty. Initial poverty has no adverse impact on growth; however it may lower the growth elasticity of poverty slightly. Furthermore, I find evidence of poverty convergence. In Chapter 3, 'Fiscal Policy and Macroeconomic Stabilility: Automatic Stabilizers Work, Always and Everywhere', I examine what can be done to protect the poor from macroeconomic shocks and volatility. Developed countries have in place in-built Counter cyclical automatic stabilizers to protect the poor from macroeconomic shocks and volatility and there is a vast literature on their effectiveness in reducing output volatility. Their effectiveness in developing countries has not been empirically validated. Using a sample of 49 countries, we estimate the impact of automatic stabilizers on output volatility and find that they strongly contribute to output stability regardless of the type of economy.
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Roux, George Bishop. "Reduction of seawall overtopping at the Strand." Thesis, Stellenbosch : Stellenbosch University, 2013. http://hdl.handle.net/10019.1/80391.
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Thesis (MScEng)--Stellenbosch University, 2013.ENGLISH ABSTRACT: The Strand is located within False Bay and frequently encounters large quantities of wave overtopping over the coastal defences. This results in the damage of property and infrastructure and causes streets to be flooded. Physical modelling tests were done by a consultancy firm to determine a solution by making use of a recurve structure at the back of the beach. This study is an expansion of the previous physical modelling that was done and focuses on several factors that were not tested by the consultancy firm that could have an influence on the overtopping rate and provide additional information on the recurve design. These tests were: (i) the effectiveness of the proposed recurve wall design in reducing overtopping was compared to a vertical wall; (ii) the influence that modifications to the beach profile such as the beach slope, beach width and beach level have on the overtopping rate; and (iii) the sensitivity of overtopping to changes in wave period was tested. The information gathered from these tests was used to propose a possible solution for the Strand. Numerical modelling was done with Delft3D-Wave to determine the wave height at the back of the beach using a nested grid. The waves at the Strand are depth limited and therefore very sensitive to changes in water level. By altering the beach level the model showed how the significant wave height at the back of the beach changes. First estimates of overtopping were determined using the relevant empirical calculations from the EuroTop Manual 2007 for a vertical seawall. No estimate could be made for the recurve wall since it did not fall in the valid range of the equations. From the physical modelling it was found that the overtopping reduced significantly from a vertical to a recurve seawall by a factor of about 50% depending on the wall height. All the prediction methods tested proved to be accurate in estimating the overtopping when the ratio of freeboard to significant wave height was ≤1.83. For non-breaking wave conditions the beach profiles that were gently sloped (1:50) and wide produced more overtopping than the beach profiles that were steep (1:10) and narrow. Increasing the beach level only decreased the overtopping if the water depth was shallow enough to cause the waves to break before they reached the back of the beach. Overtopping was found to increase with longer wave periods until the wave period became too long and the waves broke offshore which resulted in the overtopping decreasing. Possible solutions to overtopping were proposed based on two beach levels and the implementation of a recurve seawall. Revised crest levels for the wall were made along the length of the beach for both the 1:20 and 1:100 year water levels.
AFRIKAANSE OPSOMMING: Die Strand is in Valsbaai geleë en ervaar dikwels baie oorspoeling deur golwe bo-oor kusverdedigingswerke. Dit lei tot skade aan eiendom sowel as aan infrastruktuur en veroorsaak dat strate oorstroom. Fisiese modelleringstoetse is deur ’n konsultasiefirma gedoen om ’n oplossing te probeer vind deur van ’n teruggebuigde struktuur aan die agterkant van die strand gebruik te maak. Hierdie studie is ’n uitbreiding van die vorige fisiese modellering wat gedoen is en fokus op verskeie faktore wat nie deur die konsultasiefirma getoets is nie. Dit kan moontlik ’n invloed op die oorspoelingstempo hê en verskaf bykomende inligting oor die ontwerp van die terugbuiging. Hierdie toetse is: (i) die doeltreffendheid van die voorgestelde ontwerp van die teruggebuigde strandmuur in die vermindering van oorspoeling word vergelyk met ’n vertikale muur; (ii) die invloed wat veranderinge aan die strandprofiel soos die helling van die strand, die wydte van die strand asook die strandvlak op die oorspoelingstempo het; en (iii) die sensitiwiteit van oorspoeling op veranderinge in golfperiode is getoets. Die inligting wat uit hierdie toetse verkry is, word gebruik om ’n moontlike oplossing vir die Strand voor te stel. Numeriese modellering is met Delft3D-Wave gedoen om die golfhoogte aan die agterkant van die strand vas te stel deur van ’n genestelde ruitenet gebruik te maak. Die golwe by die Strand word deur diepte beperk en is dus baie sensitief vir veranderinge in die watervlak. Deur die strandvlakke te verander het die model getoon hoe die betekenisvolle golfhoogte aan die agterkant van die strand verander. Die eerste beramings van oorspoeling is bepaal deur van die relevante empiriese berekenings uit die EuroTop-handleiding 2007 vir ’n vertikale strandmuur gebruik te maak. Daar kon geen beraming vir die teruggebuigde muur gemaak word nie aangesien dit nie binne die geldige bereik van die vergelykings val nie. Uit die fisiese modellering is daar vasgestel dat oorspoeling noemenswaardig met ’n gemiddeld van ongeveer 50% verminder is, afhangend van die muurhoogte. Al die voorspellingmetodes wat getoets is was akkuraat in die beraming van die oorspoeling wanneer die verhouding van vryboord tot betekenisvolle golfhoogte ≤1.83 was. Vir nie-brekende golftoestande het strandprofiele met ’n lae helling (1:50) en wat wyd was meer oorspoeling tot gevolg gehad as strandprofiele wat steil (1:10) en nou was. ’n Verhoging in die strand se vlakke het die oorspoeling slegs verminder indien die diepte van die water vlak genoeg was om die golwe te laat breek voordat hulle die agterkant van die strand bereik het. Oorspoeling is gevind om te vermeeder met verlengde golflengte tot dat die golflengte só lank geword het dat die golwe in dieper water begin breek wat aanlieding tot verminderde oorspoeling gegee het. Daar word moontlike oplossings vir oorspoeling voorgestel gebaseer op twee strandvlakke en die implementering van ’n teruggebuigde strandmuur. Voorgestelde golfkruinvlakke vir die muur is al langs die lengte van die strand gemaak vir beide die 1:20- en 1:100-jaar watervlakke.
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Watson, Paul. "The parallel reduction of lambda calculus expressions." Thesis, University of Manchester, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.377690.
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Toft, Malcolm. "The reduction tomography of materials-forming processes." Thesis, University of Newcastle Upon Tyne, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.299421.
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Clark, Peter. "Devices for the reduction of pipeline vibration." Thesis, University of Southampton, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.296445.
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Sotiropoulos, Sotirios. "The cathodic reduction of oxygen at microelectrodes." Thesis, University of Southampton, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.240817.
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Aliferis, Panagiotis (Panos) Preskill John P. Preskill John P. "Level reduction and the quantum threshold theorem /." Diss., Pasadena, Calif. : California Institute of Technology, 2007. http://resolver.caltech.edu/CaltechETD:etd-03252007-155200.
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Ramirez, Julio C. "Vehicular CO2 Reduction in the United States." Digital Commons at Loyola Marymount University and Loyola Law School, 2014. https://digitalcommons.lmu.edu/etd/428.
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As a consequence of the Arab oil embargo in 1973, the United States enacted the first Corporate Average Fuel Consumption standards in 1975 through the Energy Policy Conservation Act enforced by the Environmental Protection Agency. These standards were to improve the fuel economy of passenger cars and light-trucks. Increasing the fuel efficiency of vehicles has not been the only goal of the Environmental Protection Agency. Along the way it has been responsible for many laws regulating the amount of harmful exhaust pipe emissions released into the environment from the combustion of petroleum fuels. This has been accomplished by (but not limited to) requiring catalytic converters on vehicle exhaust systems, the elimination of lead from gasoline, and putting limits on smog causing nitrous oxides (NOx), sulfur oxides (SOx) and tailpipe particulate matter. In the United States, it is estimated that as of 2011, when compared to the Commercial and Residential, Agricultural, Electricity, and other industries, the transportation sector accounts for 28% of GHG (primarily CO2) emissions. According to the National Oceanic Atmospheric Administration (NOAA), global CO2 concentrations in the environment have exceeded historic natural occurring levels. Since CO2 is a gas that naturally traps heat, it is believed to be the main cause of global warming. As a response to the threat of global warming, the United States once again has passed new CAFE standards for model year vehicles 2017 through 2025 to decrease the dependency on petroleum fuels and reducing CO2 in the environment. Enforced by the EPA and National Highway Transportation Safety Administration (NHTSA), the law aims to double the current combined fuel efficiency of passenger cars and light-trucks by 2025 to 54.5 miles per gallon while capping the limit of tailpipe CO2 emissions to 163 grams per mile.
As a responsible consumer, selecting a vehicle with high fuel efficiency and low CO2 emissions will play a key role in reduction of CO2 emissions in the automotive sector. The environment is something that the entire global population has in common, making us environmental stakeholders. As such, we must do our part to preserve the environment for future generations. (Picture on cover courtesy of www.car-emissions-explained.co.uk)
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Harji, Rakesh R. "The Birch reduction of electron-deficient pyrroles." Thesis, University of Manchester, 1999. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.629693.
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Stealey, Patrick Thomas. "Against the Reduction of Qualia to Indexicality." Ohio University Honors Tutorial College / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=ouhonors1366720014.
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Debeney, Louis. "Control Cost Reduction in the Aerospace Industry." Thesis, KTH, Rymdteknik, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-215004.
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This report deals with new technologies about control time saving and reliability within a manufacturing unit at Airbus Safran Launchers. Firstly, it analyses various kind of checked performances and describes how checking processes work in the different workshops and define what the main problems are. Then, it focuses on checking countersunk holes control and on three-dimensional control. It studies two kinds of new technologies and explains how it can decrease checking time relating to these two issues and how it can increase control reliability. To conclude, it also presents some other technologies which reach the same goal.Denna studie tittar på teknologier som ökar tillförlitligheten och minskar tidsåtgången för kontroll av tillverkade delar vid Airbus Safran Launchers. Först studeras olika typer av kontroller, deras effektivitet och tillförlitlighet, för att kunna identifiera de huvudsakliga problemen. Sedan fokuserar denna studie på procedurerna för kontroll av försänkta hål och då speciellt tredimensionell kontroll. Två nya kontrollteknologier undersöks utifrån hur de kan minska tidsåtgången och öka tillförlitligheten. Flera andra teknologier presenteras också för en mer komplett jämförelse och bredare slutsatser om teknologiernas måluppfyllelse.
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Bena, Luvuyo Clifford. "Investigations into the asymmetric reduction of ketones." Thesis, University of Port Elizabeth, 2003. http://hdl.handle.net/10948/323.
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A six-step synthesis of salbutamol from methyl salicylate with an overall yield of 17% has been completed, although the yield was not optimised. In the process, Zn(BH4)2 was found to selectively reduce a ketone carbonyl group in the presence of an ester unit. In contrast, borane was found to reduce both the ketone and ester carbonyl groups. Reduction of phenacyl bromide with borane in the presence of chiral catalysts based on (R)-alaninol and (R,S)-ephidrine resulted a measure of enantioselectivity in the product. However, the configuration of the alcohol obtained in the case of (R)-alaninol was contrary to expectations based both on experimental trends observed elsewhere as well as our own theoretical predictions. The asymmetric reduction of methyl 5-bromoacetyl-2-benzyloxybenzoate was accomplished with both borane and Zn(BH4)2 in the presence of a range of chiral catalysts. Optically active products were obtained in all cases, although the optical rotations were significantly smaller in the case of Zn(BH4)2. Unfortunately, we were not successful in determining the enantiomeric excesses of these reactions. The use of a NMR lanthanide shift reagent resulted in a complex spectrum that was impossible to interpret unambiguously. This presumably arises from the presence of several Lewis base sites in the product at which complexation with the shift reagent can take place. It was also not possible to determine the optical rotation of salbutamol itself owing to the relatively small amount of material obtained. A conformational analysis of salbutamol, where NMR data was correlated with molecular modelling results, was successfully carried out and revealed a strong preference for that conformer family characterised by O–C–C–N and Ar–C–C–N torsion angles of ca. 60º and 180º, respectively. Interestingly, these conformers are found to be stabilised by OH…N rather than NH…O hydrogen bonding. This study has also confirmed the effectiveness of the MMFF94 force field for conformational analysis studies in compounds of this kind. Lastly, a relatively simple method for modelling the BH3/oxazaborolidine reduction of ketones at the PM3 semiempirical MO level of approximation was devised. This approach has provided insights into the mechanism of the reaction and has furthermore enabled us to predict the enantioselectivities likely to result from various catalysts and ketones. In comparing our theoretical and experimental findings, an anomalous result was observed in the case of (R)-alaninol; this will have to be investigated further, particularly at the experimental level. However, we believe that our approach provides a sound basis for aiding the design and screening of new, potentially better catalysts.
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Rioual, Jean-Luc. "The automatic control of boundary layer transition." Thesis, University of Southampton, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.259625.
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Thorpe, Clare. "The biogeochemistry of radioactively contaminated land." Thesis, University of Manchester, 2012. https://www.research.manchester.ac.uk/portal/en/theses/the-biogeochemistry-of-radioactively-contaminated-land(6407b765-9638-4707-8f7d-ef93bf603726).html.
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A global legacy of radioactively contaminated land exists as a result of nuclear fuel cycle operations. Demonstration of the safe management of the UK nuclear legacy, including contaminated land, is important whilst the long term fate of legacy waste remains uncertain and the UK is moves towards new nuclear power. One aspect of nuclear contaminated land research focuses on the immobilisation of intermediate and long lived radionuclides that are mobile in groundwater and are migrating in the environment. At Sellafield nuclear facility, UK, strontium-90 and technetium-99 are found as co-contaminants in groundwater alongside the most abundant non radioactive contaminant, nitrate. Their differing radiochemical behaviour and the presence of nitrate presents a challenge for remediation strategies. Bioremediation has the potential for in-situ immobilization of 99Tc via reduction from mobile Tc(VII) to less mobile Tc(IV) concurrent with Fe(III) reduction. In this project bioreduction processes were investigated in sediment microcosms and model systems under variable pH and nitrate conditions and using microorganisms representative of the Sellafield site. Sediment bioreduction occurred via stimulation of the natural microbial community. Denitrification resulted a delay in the onset of metal reduction followed by a raised pH. At the mildly acidic pH of the natural sediments, a nitrate concentration of 100 mM caused bioreduction to stall. However, at pH 7, reduction of 100 mM nitrate resulted in a final pH > 9 and alkaline Fe(III) reduction. In bioreduced sediments, the microbial ecology was dominated by nitrate reducing microorganisms and Fe(III) reducing enrichment cultures were necessary to identify relevant alkaline Fe(III) reducing bacteria. Enrichment cultures isolated a novel alkali tolerant Fe(III) reducing Serratia sp. with a growth range of pH 4 to 9. Increased pH resulting from denitrification decreased the mobility of Sr2+ via increased sorption to mineral surfaces. X-ray absorption spectroscopy confirmed Sr2+ incorporation into carbonate mineral phases above pH 8.5. Model systems showed reductive removal of 99Tc from solution by an Fe(II) bearing mineral assemblage at both pH 7 and 9. In contrast Sr2+ remained in solution at pH 7 and precipitated as SrCO3 at pH > 8.5. This study for the first time demonstrates the effects of high nitrate on pH in Sellafield type sediments, alkaline Fe(III) reduction by a Serratia sp, the incorporation behaviour of Sr2+ during sediment bioreduction and the behaviour of Sr2+ and 99Tc in novel Fe(II) mineral bearing model systems. These findings improve the understanding of radionuclide migration at contaminated sites and inform possible engineered bioremediation scenarios.
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Gibson, A. W. "The role of the reticuloendothelial system in LDL metabolism." Thesis, University of Glasgow, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.381452.
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Phillips, Rhonda D. "Improving the Performance of a Hybrid Classification Method Using a Parallel Algorithm and a Novel Data Reduction Technique." Thesis, Virginia Tech, 2007. http://hdl.handle.net/10919/42680.
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This thesis presents both a shared memory parallel version of the hybrid classification algorithm IGSCR (iterative guided spectral class rejection) and a novel data reduction technique that can be used in conjuction with pIGSCR (parallel IGSCR). The parallel algorithm is motivated by a demonstrated need for more computing power driven by the increasing size of remote sensing datasets due to higher resolution sensors, larger study regions, and the like. Even with a fast algorithm such as pIGSCR, the reduction of dimension in a dataset is desirable in order to decrease the processing time further and possibly improve overall classification accuracy.
pIGSCR was developed to produce fast and portable code using Fortran 95, OpenMP, and the Hierarchical Data Format version 5 (HDF5) and accompanying data access library. The applicability of the faster pIGSCR algorithm is demonstrated by classifying Landsat data covering most of Virginia, USA into forest and non-forest classes with approximately 90 percent accuracy. Parallel results are given using the SGI Altix 3300 shared memory computer and the SGI Altix 3700 with as many as 64 processors reaching speedups of almost 77. This fast algorithm allows an analyst to perform and assess multiple classifications to refine parameters. As an example, pIGSCR was used for a factorial analysis consisting of 42 classifications of a 1.2 gigabyte image to select the number of initial classes (70) and class purity (70%) used for the remaining two images.
A feature selection or reduction method may be appropriate for a specific lassification method depending on the properties and training required for the classification method, or an alternative band selection method may be derived based on the classification method itself. This thesis introduces a feature reduction method based on the singular value decomposition (SVD). This feature reduction technique was applied to training data from two multitemporal datasets of Landsat TM/ETM+ imagery acquired over a forested area in Virginia, USA and Rondonia, Brazil. Subsequent parallel iterative guided spectral class rejection (pIGSCR) forest/non-forest classifications were performed to determine the quality of the feature reduction. The classifications of the Virginia data were five times faster using SVD based feature reduction without affecting the classification accuracy. Feature reduction using the SVD was also compared to feature reduction using principal components analysis (PCA). The highest average accuracies for the Virginia dataset (88.34%) and for the Amazon dataset (93.31%) were achieved using the SVD. The results presented here indicate that SVD based feature reduction can produce statistically significantly better classifications than PCA.Master of Science