Physical dynamic simulation of shipboard power system components in a distributed computational environment

Shipboard power systems have different characteristics than the utility power systems. In the Shipboard power system it is crucial that the systems and equipment work at their peak performance levels. One of the most demanding aspects for simulations of the Shipboard Power Systems is to connect the device under test to a real-time simulated dynamic equivalent and in an environment with actual hardware in the Loop (HIL). The real time simulations can be achieved by using multi-distributed modeling concept, in which the global system model is distributed over several processors through a communication link. The advantage of this approach is that it permits the gradual change from pure simulation to actual application. In order to perform system studies in such an environment physical phase variable models of different components of the shipboard power system were developed using operational parameters obtained from finite element (FE) analysis. These models were developed for two types of studies low and high frequency studies. Low frequency studies are used to examine the shipboard power systems behavior under load switching, and faults. High-frequency studies were used to predict abnormal conditions due to overvoltage, and components harmonic behavior. Different experiments were conducted to validate the developed models. The Simulation and experiment results show excellent agreement. The shipboard power systems components behavior under internal faults was investigated using FE analysis. This developed technique is very curial in the Shipboard power systems faults detection due to the lack of comprehensive fault test databases. A wavelet based methodology for feature extraction of the shipboard power systems current signals was developed for harmonic and fault diagnosis studies. This modeling methodology can be utilized to evaluate and predicate the NPS components future behavior in the design stage which will reduce the development cycles, cut overall cost, prevent failures, and test each subsystem exhaustively before integrating it into the system.

An examination of the possible consolidation of African American political power through selective migration

This study examined whether African Americans could consolidate political power through a migration into a specific state or set of states in sufficient numbers to establish a voting majority within that state. In order to examine the feasibility and efficacy of this strategy, a variety of factors were reviewed, including the historical context leading to the current situation; the political benefits to be derived from the control of a state; and the population and migration patterns of African Americans. The results indicated that this strategy could succeed in providing significant substantive and symbolic political benefits to the African American community, but could also have some negative repercussions.

Design and analysis of micro-channel heat-exchanger embedded in Low Temperature Co-fire Ceramic (LTCC)

Increased device density, switching speeds of integrated circuits and decrease in package size is placing new demands for high power thermal-management. The convectional method of forced air cooling with passive heat sink can handle heat fluxes up-to 3-5W/cm2; however current microprocessors are operating at levels of 100W/cm2, This demands the usage of novel thermal-management systems. In this work, water-cooling systems with active heat sink are embedded in the substrate. The research involved fabricating LTCC substrates of various configurations - an open-duct substrate, the second with thermal vias and the third with thermal vias and free-standing metal columns and metal foil. Thermal testing was performed experimentally and these results are compared with CFD results. An overall thermal resistance for the base substrate is demonstrated to be 3.4oC/W-cm2. Addition of thermal vias reduces the effective resistance of the system by 7times and further addition of free standing columns reduced it by 20times.

Effect of child care subsidies on price and quality of care for low -income families

This dissertation examines the effect of regulations, resource and referral agencies, and subsidies on price and quality of care in child care centers. This research is based on a carefully developed conceptual framework that incorporates the factors affecting the demand and supply of child care. The first step in developing this framework is sketching out the structural equations. The structural equations help us understand the underlying behavior of individuals and firms making a decision. The exogenous variables are vector of attributes relating to family characteristics, child characteristics, regulations, subsidy, community characteristics and prices of inputs. Based on the structural equations, reduced form equations are estimated to find the effect of each of the exogenous variables on each of the endogenous variables. Reduced form equations help us answer public policy questions. The sample for this study is from the 1990 Profile of Child Care Settings (PCCS) data in which 2,089 center based programs were interviewed. Child/Staff Ratio (Group Level): Results indicate that among subsidies, only the state subsidy per child in poverty has a significant effect on the child/staff ratio at the group level. Presence of resource and referral agencies also increase the child/staff ratio at the group level. Also when the maximum center group size regulation for 25-36 months becomes more stringent, the child/staff ratio at the group level decreases. Child/Staff Ratio (Center Level): When the regulations for the maximum child/staff ratio for age groups 13-24 months and 37-60 months become lax, the child/staff ratio for the center increases. As the regulation for maximum group size for infants becomes stringent, the child/staff ratio decreases. An interesting finding is that as the regulations for maximum group size for age groups 13-24 months and 25-36 months become stringent, the child/staff ratio for the center increases. Another significant finding is that when a center is located in a rural area the child/staff ratio is significantly lower. Center Weighted Average Hourly Fees: Maximum group size regulations for age groups 25-36 months and 37-60 months have a negative effect on center hourly fee. Maximum child staff regulations for age groups 13-24 months and 37-60 months have a negative effect on center hourly fee. Maximum child staff regulations for age groups 0-12 months and 25-36 months have a positive effect on center hourly fee. Findings also indicate that the center average hourly price is lower when there is a resource and referral agency present. Cost adjusted prekindergarten funds and JOBS child care subsidies have a negative effect on average hourly fee. Cost adjusted social services block grant and state subsidy per child in poverty have a positive effect on the average hourly price. A major finding of this dissertation is the interaction of subsidy and regulatory variables. Another major finding is that child/staff ratio at the group level is lower when there is an interaction between geographic location and nature of center sponsorship.

Inflation, currency substitution, and dollarization : the case of Argentina

This dissertation discusses the relationship between inflation, currency substitution and dollarization that has taken place in Argentina for the past several decades. First, it is shown that when consumers are able to hold only domestic monetary balances (without capital mobility) an increase in the rate of inflation will produce a balance of payments deficit. We then look at the same issue but with heterogeneous consumers, this heterogeneity being generated by non-proportional lump-sum transfers. Second, we discussed some necessary assumptions related to currency substitution models and concluded that there was no a-priori conclusion on whether currencies should be assumed to be "cooperant" or "non-cooperant" in utility. That is to say, whether individuals held different currencies together or one instead of the other. Third, we went into discussing the issue of currency substitution as being a constraint on governments inflationary objectives rather than a choice of those governments to avoid hyperinflations. We showed that imperfect substitutability between currencies does not "reduce the scope for rational (hyper)inflationary processes" as it had been previously argued. It will ultimately depend on the parametrization used and not on the intrinsic characteristics of imperfect substitutability between currencies. We further showed that in Argentina, individuals have been able to endogenize the money supply by holding foreign monetary balances. We argued that the decision to hold foreign monetary balances by individuals is always a second best due to the trade-off between holding foreign monetary balances and consumption. For some levels of income, consumption, and foreign inflation, individuals would prefer to hold domestic monetary balances rather than foreign ones. We then modeled the distinction between dollarization and currency substitution. We concluded that although dollarization is necessary for currency substitution to take place, the decision to use foreign monetary balances for transactions purposes is largely independent from the dollarization process. Finally, we concluded that Argentina should not fully dollarize its economy because dollarization is always a second best to using a domestic currency. Further, we argued that a fixed exchange system would be better than a flexible exchange rate or a "crawling-peg" system because of the characteristics of the political system and the possibilities of "mass praetorianism" to develop, which is intricately linked to "populist" solutions.

Docking and simulation study of the enantiospecificity of chiral epoxidation reactions catalyzed by chloroperoxidase

Chloroperoxidase (CPO), a 298-residue glycosylated protein from the fungus Caldariomyces fumago, is probably the most versatile heme enzyme yet discovered. Interest in CPO as a catalyst is based on its power to produce enantiomerically enriched products. Recent research has focused its attention on the ability of CPO to epoxidize alkenes in high regioselectivity and enantioselectivity as an efficient and environmentally benign alternative to traditional synthetic routes. There has been little work on the nature of ligand binding, which probably controls the regio- and enantiospecifity of CPO. Consequently it is here that we focus our work. We report docking calculations and computer simulations aimed at predicting the enantiospecificity of CPO-catalyzed epoxidation of three model substrates. On the basis of this work candidate mutations to improve the efficiency of CPO are predicted. In order to accomplish these aims, a simulated annealing and molecular dynamics protocol is developed to sample potentially reactive substrate/CPO complexes.

Process inventory and pollution prevention overview for the citrus industry

Florida citrus represents approximately 70 percent of the industry production in the United States; therefore, any associated agricultural and industrial contamination is of concern and a focus of attention. The use of synthetic organic chemicals has become a farmer's necessity in order to supply consumers with high quality products, free of pest damage. However, industrial citrus wastes and chemical residual levels worry not only government agencies but also consumers since they indicate a serious habitat risk. This study assesses citrus industrial processes and the paths that chemical substances follow from the time the citrus seed is planted until consumers get a final product as either fresh fruit or processed product. The study is built on information from United States Environmental Protection Agency (US EPA) manuals, Dade County Environmental Resources Management (DERM) inspection records, United States Food and Drug Administration (US FDA) regulations, Florida standards, journal publications, and research reports. Pollution prevention (P2 or prevention-of-pollution) alternatives are identified; alternatives are proposed, evaluated, and included. Strategies are described and pollution prevention opportunities proposed to minimize citrus wastes generation, chemical residuals in products, their environmental impact and health risk aspects while maximizing product quality.

Waveguide microgripper for identification, sensing and manipulation

A Waveguide Microgripper utilizes flexible optical waveguides as gripping arms, which provide the physical means for grasping a microobject, while simultaneously enabling light to be delivered and collected. This unique capability allows extensive optical characterization of the structure being held such as transmission, reflection or fluorescence. One of the simplest capabilities of the waveguide microgripper is to be able to detect the presence of a microobject between the microgripper facets by monitoring the transmitted intensity of light coupled through the facets. The intensity of coupled light is expected to drop when there is an object obstructing the path of light. The optical sensing and characterization function of the microgripper is a strong function of the optical power incident on the structure of interest. Hence it is important to understand the factors affecting the power distribution across the facet. The microgripper is also capable of detecting the fluorescence. This capability of microgripper is expected to have applications in medical, bio-medical and related fields.

The potential of solid phase microextraction (spme) for the recovery of explosives followed by gas and liquid chromatographic analysis

The potential of solid phase microextraction (SPME) in the analysis of explosives is demonstrated. A sensitive, rapid, solventless and inexpensive method for the analysis of explosives and explosive odors from solid and liquid samples has been optimized using SPME followed by HPLC and GC/ECD. SPME involves the extraction of the organic components in debris samples into sorbent-coated silica fibers, which can be transferred directly to the injector of a gas chromatograph. SPME/HPLC requires a special desorption apparatus to elute the extracted analyte onto the column at high pressure. Re suits for use of GC[ECD is presented and compared to the results gathered by using HPLC analysis. The relative effects of controllable variables including fiber chemistry, adsorption and desorption temperature, extraction time, and desorption time have been optimized for various high explosives.

Analysis of the lateral diffuse metal-oxide semiconductor (LDMOS) power amplifier for cellular base stations

The primary purpose of this thesis was to present a theoretical large-signal analysis to study the power gain and efficiency of a microwave power amplifier for LS-band communications using software simulation. Power gain, efficiency, reliability, and stability are important characteristics in the power amplifier design process. These characteristics affect advance wireless systems, which require low-cost device amplification without sacrificing system performance. Large-signal modeling and input and output matching components are used for this thesis. Motorola's Electro Thermal LDMOS model is a new transistor model that includes self-heating affects and is capable of small-large signal simulations. It allows for most of the design considerations to be on stability, power gain, bandwidth, and DC requirements. The matching technique allows for the gain to be maximized at a specific target frequency. Calculations and simulations for the microwave power amplifier design were performed using Matlab and Microwave Office respectively. Microwave Office is the simulation software used in this thesis. The study demonstrated that Motorola's Electro Thermal LDMOS transistor in microwave power amplifier design process is a viable solution for common-source amplifier applications in high power base stations. The MET-LDMOS met the stability requirements for the specified frequency range without a stability-improvement model. The power gain of the amplifier circuit was improved through proper microwave matching design using input/output-matching techniques. The gain and efficiency of the amplifier improve approximately 4dB and 7.27% respectively. The gain value is roughly .89 dB higher than the maximum gain specified by the MRF21010 data sheet specifications. This work can lead to efficient modeling and development of high power LDMOS transistor implementations in commercial and industry applications.

Influence, policy formation, and higher education in Florida : 1989-94

This study examined the perceptions of state governmental officials and administrators from the state university system, community college system, and independent institutions concerning the ability of various groups to influence state-level higher education policy formation. The study was conducted in Florida for the period 1989-94. Florida has a history of legislative involvement in higher education, an unique system of state universities and community colleges, and a limited number of private institutions of higher education. This study was grounded in the works of Mortimer and McConnell (1978), Millett (1987), Marshall, Mitchell, and Wirt (1989) and Finitfer, Baldwin, and Thelin (1991). The study represented the application of an embedded, single-case design. A survey was the primary collection instrument. Respondents were asked questions concerning: (a) personal involvement in higher education, (b) perceptions of the ability of various groups to influence higher education policy, (c) the names of particular individuals considered key players in higher education policy formation, (d) important state-level documents, (e) personal knowledge of key areas of policy formation, and (f) emerging higher education issues in Florida. Quantitative and qualitative methods were used to analyze the different sections of the survey. The findings indicated that a power and influence hierarchy exists among the various groups that attempt to influence higher education policy and that this hierarchy is recognized by state government officials and higher education administrators. While an analysis of variance of the various groups revealed a few differences between state government officials and higher education personnel, the high overall agreement was an important finding. Leading members of the legislature, especially the Chair of the Senate Higher Education Committee, and key staff members, especially from the Senate Ways & Means Committee, were considered the most influential. Representatives from higher education institutions and research organizations were considered among the least influential. Emerging issues identified by the respondents included: (a) the political nature of state-level policy formation, (b) the role of legislative staff, (c) the competition for state moneys, (d) legislative concern for state-wide budgetary efficiency, and (e) legislative attempts to define quality and supervise academic program development for higher education.

The United States and the politics of trade: the banana war with Europe and the Caribbean

This thesis examines the involvement of the United States in the decade-long trade dispute before the World Trade Organization (WTO) over the European Union's preferential banana regime. Washington's justification for bringing this case to the WTO comes from Section 301 of the U.S. trade act, which allows for disputes to be undertaken if U.S. "interests" are violated; however, this is the first case ever undertaken by the United States that does not directly threaten any American banana industry, nor affect any American jobs. Why, then, would the United States involve itself in this European-Caribbean-Latin American dispute? It is the contention of this thesis that the United States thrust itself headlong into this debate for two reasons: domestically, the United States Trade Representative came under pressure, via the White House and Congress, from Chiquita CEO Carl Lindner, who in the past decade donated more than $7.1 million to American politicians to take the case to the WTO. Internationally, the United States used the case as an opportunity to assert its power over Europe, with the Eastern Caribbean islands being caught in the economic crossfire. According to existing literature, in undertaking this case, the United States did as any nation would: it operated within both domestic and international levels, satisfying at each level key interests, with the overall goal of maintaining the nation's best interests.

School desegregation in Broward County, Florida 1970-1998 : a historical study of power

This is a historical case study on school desegregation and power in Broward County, Florida from 1970 to 1998. The purpose of this study is to describe, explain and analyze types of power used by the School Board of Broward County, Florida and community activists, in their efforts to influence desegregation decisions from 1970 to 1998. In addition, this study explains who benefited and who won from the School Board's desegregation decisions and who governed those decisions? A historical case study approach was used as the method for conducting this study. Data sources included 11 interviews of individuals who were involved in school desegregation issues as either School Board officials or community activists and 10 archival data sources. The theoretical models of Russell, Galbraith, Wartenberg and Domhoff were used to determine the different types of power techniques used by School Board officials and community activists and to answer the questions: who benefited and who won from the School Board's desegregation decisions and who governed those policies and practices? The primary beneficiaries of school desegregation policies and practices in Broward County were: white, affluent communities and the builders, developers, realtors and other businesses in the western suburban communities. All of the data sources indicated that the black community did not benefit from the School Board's desegregation policies. The primary power techniques used by School Board officials to influence desegregation policies and practices was "power over opinions" and compensation. These power techniques were manifested by the School Board publicly disputing the allegations raised by community activists and by compensating those who supported and promoted the School Board's desegregation policies and practices. The power techniques primarily used by community activists were coercive force and "power over opinions." They effectively used these power techniques to change the School Board's policies and practices they felt were detrimental to black children and the black community. Based on the analysis of the qualitative data, it can be concluded that black children did not benefit from school desegregation in Broward County, Florida and the community continues to suffer residual effects from past desegregation policies and practices.

Inventing indigenous religious belief and practice within the spaces of Ghanaian Pentecostalism : the Mame Wata healing churches of Half Assini

Goddesses in African religions are spirits that affect humans and demand reverence from them. They are also embodiments of ideas that African people have about women, their powers and their roles in society. This study focused on Mame Wata, a goddess in Half Assini, an Nzema-speaking coastal community in western Ghana. It sought to resolve a paradox, that is, the fact that, the goddess is at the center of a Pentecostalist tradition even though traditional Pentecostalism in Ghana views her as an agent of the devil. The study involved fieldwork in this community of the goddess's female worshippers led by Agyimah, a charismatic man, and an agent of the goddess. The study interpreted the goddess as a post-colonial invented symbol personifying both pre-colonial and emerging ideas about female power. Findings from the study also show that through Mame Wata the followers celebrate the spirituality of the female.

The use of presidential executive orders to control the management and administration of the federal government

As long as governmental institutions have existed, efforts have been undertaken to reform them. This research examines a particular strategy, coercive controls, exercised through a particular instrument, executive orders, by a singular reformer, the president of the United States. The presidents studied- Johnson, Nixon, Ford, Carter, Reagan, Bush, and Clinton-are those whose campaigns for office were characterized to varying degrees as against Washington bureaucracy and for executive reform. Executive order issuance is assessed through an examination of key factors for each president including political party affiliation, levels of political capital, and legislative experience. A classification typology is used to identify the topical dimensions and levels of coerciveness. The portrayal of the federal government is analyzed through examination of public, media, and presidential attention. The results show that executive orders are significant management tools for the president. Executive orders also represent an important component of the transition plans for incoming administrations. The findings indicate that overall, while executive orders have not increased in the aggregate, they are more intrusive and significant. When the factors of political party affiliation, political capital, and legislative experience are examined, it reveals a strong relationship between executive orders and previous executive experience, specifically presidents who served as a state governor prior to winning national election as president. Presidents Carter, Reagan, and Clinton (all former governors) have the highest percent of executive orders focusing on the federal bureaucracy. Additionally, the highest percent of forceful orders were issued by former governors (41.0%) as compared to their presidential counterparts who have not served as governors (19.9%). Secondly, political party affiliation is an important, but not significant, predictor for the use of executive orders. Thirdly, management strategies that provide the president with the greatest level of autonomy-executive orders redefine the concept of presidential power and autonomous action. Interviews of elite government officials and political observers support the idea that executive orders can provide the president with a successful management strategy, requiring less expenditure of political resources, less risk to political capital, and a way of achieving objectives without depending on an unresponsive Congress.