The goal of the present work is to develop an open architecture engine controller to operate a production model, heavy-duty diesel engine. Where OEM engine control units (ECUs) are inflexible, this controller is designed to provide the hardware and software flexibility required to facilitate dualuel combustion research. This thesis includes thorough descriptions of the hardware and software development required to interface with all engine sensors and actuators. To establish baseline control settings for the open controller, OEM ECU responses are mapped over a range of speeds and loads. This information is used to calibrate the open controller. Comparison tests considering speed, load, and emissions are performed to ensure the open controller provides a close approximation of OEM engine operation. The results of the tests confirm that the open controller provides full control of the engine with baseline settings close to those of the OEM ECU.

Dual fuel combustion is one strategy to achieve low oxides of nitrogen and soot emissions while maintaining the fuel conversion efficiency of IC engines. However, it also suffers from high engine-out carbon monoxide and unburned hydrocarbon emissions, and the incidence of knock at high loads. The present work focused on CFD simulation of diesel-methane dual fuel combustion in a single-cylinder research engine (SCRE). For pure diesel combustion, a load sweep of 2.5 bar brake mean effective pressure (BMEP) to 7.5 bar BMEP was performed at a constant engine speed of 1500 rpm and a diesel injection pressure of 500 bar. For diesel-methane dual fuel combustion, a methane percent energy substitution sweep was performed from 30% to 90 % at 1500 rpm, 3.3 bar BMEP, 500 bar Pinj, and 355 crank angle degrees (CAD) diesel injection timing. Combustion, performance, and emissions results are presented and compared with experimental data where possible.

In line with the national trend, Mississippi faces the same challenge that fewer students are completing college degrees. In response to the national call for more degrees, many states have implemented dual enrollment programs to try to decrease the transition anxiety between high school and college, which could possibly lead to more college degrees. This study will add to the very limited body of quantitative research relating to the relationship between students participating in dual enrollment and college degree completion at rural Mississippi community colleges. With an increased focus on a higher number of college graduates, this study could provide information for rural community colleges in Mississippi in regards to retention of dual enrollment participants through obtaining a degree. The purpose of this study was to determine whether or not there was a significant difference in the number of students completing an Associate’s degree when comparing students who participated in a dual enrollment program to students who did not participate in a dual enrollment program at a rural Mississippi community college. The sample was comprised of 320 students - 160 students who participated in dual enrollment and a comparative group of 160 students who did not participate in dual enrollment - from across the district of the target community college. Participants included students who were enrolled at the target community college in the fall and spring semesters of 2010 and 2011. A Chi-square test for independence was used for all four research questions to analyze the two categorical variables. Results of the study indicate that there is a significant relationship between the participation in dual enrollment and the completion of a degree, AA and AAS, at the target community college. Findings indicate that students who participate in the dual enrollment program are much less likely to complete their degree at the target community college. There is a need to further investigate dual enrollment as it pertains to completion of a degree at a rural Mississippi community college.

Creativity is increasing in value worldwide, but the processes underlying various creative abilities remain ambiguous. The most frequently used assessments of creativity (i.e., divergent thinking tasks; creative problem-solving tasks) differ in surface features and are also rarely examined together. These inconsistencies, in addition to mixed findings in the literature, have caused considerable debate among creativity researchers concerning the particular roles of independent or dual processes that lead to success on different creativity tests. The present study expounded upon these mixed findings using a factor analytic method. The results indicated that individual differences in working memory and fluency ability impact performance on divergent thinking and creative problem-solving tasks, but to differing degrees. These results are discussed as supporting a dual-process view of creative thinking.

The goal of this study is to assess conventional and low temperature dual fuel combustion in light- and heavy-duty multi-cylinder compression ignition engines in terms of combustion characterization, performance, and emissions. First, a light-duty compression ignition engine is converted to a dual fuel engine and instrumented for in-cylinder pressure measurements. The primary fuels, methane and propane, are each introduced into the system by means of fumigation before the turbocharger, ensuring the airuel composition is well-mixed. Experiments are performed at 2.5, 5, 7.5, and 10 bar BMEP at an engine speed of 1800 RPM. Heat release analyses reveal that the ignition delay and subsequent combustion processes are dependent on the primary fuel type and concentration, pilot quantity, and loading condition. At low load, diesel-ignited propane yields longer ignition delay periods than diesel-ignited methane, while at high load the reactivity of propane is more pronounced, leading to shorter ignition delays. At high load (BMEP = 10 bar), the rapid heat release associated with diesel-ignited propane appears to occur even before pilot injection, possibly indicating auto-ignition of the propane-air mixture. Next, a modern, heavy-duty compression ignition engine is commissioned with an open architecture controller and instrumented for in-cylinder pressure measurements. Initial diesel-ignited propane dual fuel experiments (fumigated before the turbocharger) at 1500 RPM reveal that the maximum percent energy substitution (PES) of propane is limited to 86, 60, 33, and 25 percent at 5, 10, 15, and 20 bar BMEP, respectively. Fueling strategy, injection strategy, exhaust gas recirculation (EGR) rate, and intake boost pressure are varied in order to maximize the PES of propane at 10 bar BMEP, which increases from 60 PES to 80 PES of propane. Finally, diesel-ignited propane dual fuel low temperature combustion (LTC) is implemented using early injection timings (50 DBTDC) at 5 bar BMEP. A sweep of injection timings from 10 DBTDC to 50 DBTDC reveals the transition from conventional to low temperature dual fuel combustion, indicated by ultra-low NOx and smoke emissions. Optimization of the dual fuel LTC concept yields less than 0.02 g/kW-hr NOx and 0.06 FSN smoke at 93 PES of propane.

The dual heap virtual implementation provided a new base for memory organization such that the heap storage can be virtually enlarged to include the extremely large disk space. Two simulation models were used to investigate aging in physical space as well as the dual heap implementation. The simulators generated results which measured the ability of each method to detect leaks generate false positives and false negatives. In comparison, the dual heap implementation showed a relatively better performance than the aging algorithm. The dual heap implementation is shown to produce less false positives and less false negatives. It has better capability of detecting memory leaks. Furthermore, dual heap implementation extends the space provide to the main heap such that programs with greedy memory consumption can also benefit from this implementation. The dual heap virtual model of the heap organization is a promising architecture, which at once masks the memory leak problem and extends the heap storage for greedy programs. The introduction and advancement of 64-bit address machine would not reduce the value of the dual virtual heap implementation, for the simple reasons that a large number of legacy programs will continue to run in a 32-bit environment, and for the fact that greedy programs and leaks will drain the heap storage of 64-bit machines as much as they did for the 32-bit machines.

Threat perception is an important issue in today's world. As the line between hostile and non-hostile entities is blurred, it becomes more important for individuals to clearly distinguish between those who would present danger and those who would not. This series of experiments tested whether observers engaged in a dual-task paradigm perceived a greater amount of threat from target stimuli than they did when they were engaged in the threat task alone. The first experiment revealed that observers rated targets as more threatening when they were engaged in the additional task than when they only rated the targets themselves. Response time to the targets was also slower when a secondary task was present. This difference was more pronounced when the secondary task was presented via the auditory channel. Participants also rated overall workload higher when performing a secondary task, with the highest ratings being associated with the dual-task auditory condition. In the second experiment, the design crossed sensory modality with the presence or non-presence of threat. Inter-stimulus interval was also manipulated. The presence of threat was associated with faster response times, though when both tasks had threat components, response time was not the fastest. Additionally, when images came first in the stimulus pairs, observers were slower to respond to the first stimulus than when the sounds were presented first. Results supported the conclusion that additional task loading can affect the perception of threat. The modality of the additional task seems to also play a role in threat assessment performance. Results also led to the conclusion that threat-related visual stimuli are more challenging to process than threat-related auditory stimuli. Future research can now investigate how different types of tasks affect the threat perception task. Implications for better training of soldiers and for the design of automated systems are presented.

One of the primary missions of the National Weather Service (NWS) is to use a network of more than 150 NEXRAD radar installations to monitor weather for threats to life and property. Large hail produced by severe thunderstorms is a major focus of this mission. An algorithm known as the Maximum Estimated Size of Hail (MESH) algorithm is in operational use to diagnose the presence and size of hail. This study aims to use dual-Doppler observations as well as the MESH algorithm to test the idea that storms that rotate produce larger hail. Previous studies have used polarimetric radar products to detect the presence of large hail and dual-Doppler methods have been used to study embryonic hail, but no research has tested the theory of hail and rotating storms with observational evidence. A set of 59 case studies was gathered; each included a hail report submitted by a trained weather spotter or NWS employee and complete radar observations through the depth of a storm from two radars. The radar observations were resampled to a three-dimensional Cartesian grid and a dual-Doppler analysis was run on each case study. A strong correlation (stronger even than the MESH algorithm) was found between measured vorticity and hail size, lending credence to the idea that rotating storms do indeed have a higher ceiling for hail production. However, no correlation was found between MESH error and rotation. Further research will be required to evaluate whether or not this relationship can be used to augment the MESH algorithm so as to improve its skill. / Master of Science

Throughout the world, systems of life science governance carry historical, cultural, and political legacies, which now confront the revolutionary and pervasive advances of twenty-first century biotechnology. Nations' adaptability to the twin challenges of attempting to secure the benefits while reducing the risks and threats is a large and still burgeoning governance challenge. The legacy of the Soviet Union is particularly important in this regard, since its history of prolonged authoritarian rule and intense development of biological weapons in combination with the continuing scientific and technological prowess of Russia is a governance challenge, unprecedented in its nature and scale. The aim of the dissertation therefore is to examine to what extent and by what means it is possible for Russia to reconcile its on-going expansion in biotechnology with the institutional and normative inertia arising from its Soviet past. The first part of the dissertation (Chapters 1-4) seeks to uncover and analyse both the growth and consolidation of the governance of biotechnology and the multifaceted governance challenges brought about by the rapid advancement of the life sciences in the twenty-first century. The second part (Chapters 5-8) examines the extent to which the Soviet institutional and infrastructural legacies in the culture of life science research still persist in Russia and impact the governance of biotechnology in that country. The concluding chapter offers an assessment of the current state of the governance of biotechnology in Russia and outlines a scope for further research. / Wellcome Trust

<p dir="ltr">Constrained optimization plays a crucial role in numerous scientific and engineering fields, where solutions must satisfy specific constraints while optimizing an objective function. The complexity of these problems has driven the development of efficient algorithms. Primal-dual methods, particularly, have been a powerful class of algorithms capable of tackling constrained optimization problems. This dissertation introduces and analyzes new Lagrangian-based primal-dual methods, exploring their applications in the equilibrium computation of generalized Nash games and non-convex constrained optimization problems. </p><p dir="ltr">Generalized Nash games, also known as generalized Nash equilibrium problems, expand the concept of classical Nash games by incorporating coupled constraints, which substantially increase their computational complexity. These games are prevalent in a variety of real-world applications, such as electricity markets, economic markets, transportation networks, and various multi-agent systems, where decision-makers are required to engage in strategic actions while also considering coupled constraints. We develop a primal-dual first-order method for efficient computation of generalized Nash equilibrium, providing its theoretical foundations and practical implementation. </p><p dir="ltr">Non-convex constrained optimization problems often emerge across various application domains, presenting significant theoretical and computational challenges due to the presence of non-convex constraints and objective functions. To address these challenges, we propose and analyze novel Lagrangian-based primal-dual methods designed to manage non-convex constraints and establish their convergence properties. We perform extensive numerical experiments to demonstrate the practicality and versatility of our proposed methods. The results show the efficacy of our methods in tackling the computational challenges associated with generalized Nash games and non-convex constrained optimization.</p>