This thesis establishes formal equational properties of multi-stage calculi and related proof techniques that support analyses of staged programs. A key promise of staging is to make programs efficient without destroying clarity, thereby reducing the likelihood of bugs. However, few publications rigorously verify that their staged programs indeed behave as intended. In fact, little is known about how staged programs can be verified, or what correctness issues staging introduces. To solve this problem, I show a reduction of the correctness of a staged program to that of an unstaged program. This reduction not only clarifies the effects of staging on program behavior but also eases verification, as unstaged programs are more susceptible to existing reasoning techniques. I also demonstrate that important single-stage reasoning techniques apply to staged programs. These techniques are useful for establishing side conditions for the reduction and for discovering or validating further reasoning principles. / NSF grant CCF-0747431

The image quality will degrade if the misfocusing problem occurs in the imaging system. This paper is aimed to design and analyze a phase mask for mutifocusing problem. Depth of field is the range to get a clear image. As the lens can only gather the light in a fixed range. Image will be more blurred when it is more from this range. In 1995 Dowski and Cathey proposed the wave-front coding to increase the system's depth of field so that the image will less susceptible to blur due to the mutifocusing problem. A treatment with a mask before the lens can extend the depth of field. In this paper, we extend to multi-levels phase mask. The simulation results show that multi-level phase mask has a better performance than the two-level phase mask.

abstract: ABSTRACT This research reveals how governments cut budgets during fiscal crises and what pattern may emerge based on the cuts. It addresses a significant gap in literature by looking into the details of an agency for a full recession period to explain how cutback requirements were met. Through investigating a large Arizona state agency during the 2008 recession in the United States, the research reveals that cutback management is a stage-by-stage process lagging the immediate deterioration of the state’s economy and that patterns found among cuts are more often rational than not. Cutbacks in this agency proceeded through three stages: the beginning, middle and the end period of cuts. In each stage, the author used descriptive analysis, process map analysis and cause and effect analysis to explore the features of cuts made. These methods of analysis were used to break down an annual budget reduction into original appropriation budget cuts, mid year reductions and the final budget cuts required to end the fiscal year in balance. In addition, the analytical methods permitted more detailed analysis of specific appropriation line items. The information used was secondary data collected from seven fiscal years around the recession and from various sources, including budgetary materials, legislation, accounting materials and many program reports related to budget cuts. The findings suggested that across-the-board cuts are implemented at the beginning of cutback stage mainly to non-mandatory programs without jeopardizing the core functions of the agency. Later, in the middle period of the recession, selective cuts are made on large programs. Fund transfers and excess balance transfers are also preferred to reduce the budgets of other restricted funds. At the end stage of budget cuts, new revenue sources are established to support programs which had relied on general fund revenues in the past. Overall, the cutback process observed in this research reflects decremental and rational patterns of decision making, contrasting with the randomness observed in previous research on cutback management. Across the board cuts are decremental; the remainders are rational, even strategic decisions. This investigation reminds researchers to be aware of the context and the level of observation when analyzing cutbacks. / Dissertation/Thesis / Doctoral Dissertation Public Administration and Policy 2018

abstract: Petroleum contamination is ubiquitous during extraction, transportation, refining, and storage. Contamination damages the soil’s ecosystem function, reduces its aesthetics, and poses a potential threat to human beings. The overall goals of this dissertation are to advance understanding of the mechanisms behind ozonation of petroleum-contaminated soil and to configure an effective integrated bioremediation + ozonation remedial strategy to remove the overall organic carbon. Using a soil column, I conducted batch ozonation experiments for different soils and at different moisture levels. I measured multiple parameters: e.g., total petroleum hydrocarbons (TPH) and dissolved organic carbon (DOC), to build a full understanding of the data that led to the solid conclusions. I first demonstrated the feasibility of using ozone to attack heavy petroleum hydrocarbons in soil settings. I identified the physical and chemical hurdles (e.g., moisture, mass transfer, pH) needed to be overcome to make the integration of chemical oxidation and biodegradation more efficient and defines the mechanisms behind the experimental observations. Next, I completed a total carbon balance, which revealed that multiple components, including soil organic matter (SOM) and non-TPH petroleum, competed for ozone, although TPH was relatively more reactive. Further experiments showed that poor soil mixing and high soil-moisture content hindered mass transfer of ozone to react with the TPH. Finally, I pursued the theme of optimizing the integration of ozonation and biodegradation through a multi-stage strategy. I conducted multi-stages of ozonation and bioremediation for two benchmark soils with distinctly different oils to test if and how much ozonation enhanced biodegradation and vice versa. With pH and moisture optimized for each step, pre-ozonation versus post-ozonation was assessed for TPH removal and mineralization. Multi-cycle treatment was able to achieve the TPH regulatory standard when biodegradation alone could not. Ozonation did not directly enhance the biodegradation rate of TPH; instead, ozone converted TPH into DOC that was biodegraded and mineralized. The major take-home lesson from my studies is that multi-stage ozonation + biodegradation is a useful remediation tool for petroleum contamination in soil. / Dissertation/Thesis / Doctoral Dissertation Civil, Environmental and Sustainable Engineering 2018

A comprehensive survey of the presence of trihalomethane (THM) compounds, as chlorination by-products, in drinking water in Kuwait have been performed. The survey covers the whole drinking water treatment cycle, starting with sea water and ending with the consumer tap. The data generated by the survey was all derived from actual water treatment plants, operating under normal conditions. All four trihalomethane compounds, namely; chloroform (CHCI3), bromodichloromethane (CHBrCI2), dibromochloromethane (CHBr2CI) and bromoform (CHBr3) were covered. The study clearly showed that, although considerable amounts of THM compounds did form as a result of chlorination of sea water entering the multi-stage flash (MSF) distillation plants, these plants were highly efficient in removing these compounds. The average removal efficiency, based on THM compounds mass load in the sea water feed, was around 95%. Factors which were found to have an influence on the degree of formation of these compounds, include, chlorination practice (continuous vs. shock), sea water temperature, level of organic precursors and contact time. Of much more important consequence, as far as the presence of these compounds in drinking water is concerned, was the degree of THM compounds formation as a result of the chlorination of drinking water before it is pumped to the consumer. Here, not only all the compounds formed remain in the water but there is a definite tendency for continuous formation well after the actual chlorination process has taken place. Factors which were found affecting this formation include water temperature, contact time and chlorination dosage. Although, all samples collected showed that the presence of THM compounds was always below the United States Environmental Protection Agency maximum contaminant level of 100 ~g/L, a need exists for the optimization of all chlorination processes with particular emphasis on the chlorination of drinking water. In almost all kinds of water encountered in this study, bromoform was found to be by far the most dominant compound.

Fresh water in Kuwait is produced by non- conventional methods. About 95% of this water comes from desalinated seawater using multi-stage flash distillation technique and the remainder comes from underground brackish water. The blended water containes organic, inorganic and trace metal impurities within the recommended international standard limits. The purpose of this work is to identify the source of selected trace metals present in the drinking water in Kuwait. Chromium, copper, iron, lead, manganese, nickel, vanadium and zinc have been analysed using atomic absorption spectroscopy (AAS) and inductively coupled plasma mass spectroscopy (ICPMS). Efforts were made to improve the preconcentration of the selected metals and their separation from the high concentration of salts in seawater which affect the accuracy and cause major interference in the analysis. Solid-liquid extraction (chelex-100 resin) and liquid-liquid extraction (methyl iso-butyl ketone and freon) with and without back-extraction into nitric acid were investigated. Liquid-liquid extraction without back-extraction proved to give optimum recovery of the selected metals. Results confirmed that both AAS and ICP-MS are suitable for the analysis of trace metals in Kuwait's waters. Although AAS technique proved to be more accurate in analysing the selected metals than ICP-MS, the latter was adopted since its accuracy is acceptable (1.1-4.4%) and it is easier and faster than the former technique. The study revealed that the source of copper, iron, nickel and zinc is the construction materials of the distillation plants, while the source of lead and vanadium is the brackish water. Manganese and chromium concentrations are very low in all sources. No direct relationship between the metal concentration in the seawater and the distillate could be deduced.

This thesis presents a multi-stage rectifier for wireless power transfer in biomedical implant systems. The rectifier is built using Schottky diodes. The design has been simulated in 0.5µm and 130nm CMOS processes. The challenges for a rectifier in a wireless power transfer systems are observed to be the efficiency, output voltage yield, operating frequency range and the minimum input voltage the rectifier can convert. The rectifier outperformed the contemporary works in the mentioned criteria.

The main objective of this thesis is to design blades for the axial pump with two counter-rotating rotors for design point. Then compare results with the standard concept with one runner and guide blades.

The blood supply chain, starting from the donor until the blood is used to meet transfusion demands of patients, is a multi-echelon and complex system. The perishable and lifesaving characteristics of blood products, such as red blood cells and platelets, as well as uncertainties in both supply and demand make it difficult to maintain a balance between shortage and wastage due to expiry. An effective blood supply chain should be able to meet the demand while at the same time reducing wastage and total operational cost. In order to be cost effective, the related organizations have to decide how much blood should be collected from donors, how much blood products should be produced at the blood center, and how much blood products should be distributed to hospitals or transshipped between hospitals. The objective of this dissertation is to provide these tactical and operational decisions to guide those who work in healthcare supply chain management and explore new opportunities on performance improvement for an integrated blood supply chain by optimization with aim of minimizing total cost, consideration of transshipment between hospitals, and application of a coordinated multi-product model. This dissertation presents three multi-stage stochastic models for an integrated blood supply chain to minimize total cost incurred in the collection, production, inventory, and distribution echelons under centralized control. The scope of this study focuses on modeling a supply chain of blood products in one regional blood center, several hospitals and blood collection facilities. First, we develop an integrated model for the platelet supply chain that accounts for demand uncertainty and blood age information, then we develop this model further by investigating the impact of transshipment between hospitals on cost savings, and then we propose a multi-product model that accounts for red blood cells and platelets at the same time and compare it with an uncoordinated model where the red blood cell and platelet supply chains are considered separately.

<div>A common assumption often made of dynamic compressors is that they are considered adiabatic, due to the fast-moving flow passing through the turbomachine and the small amount of any heat transfer relative to the large amount of work transferred to/from the flow. This research investigation combined the use of experimental measurements and computational simulations to take a deeper look into the implications that arise from applying this adiabatic assumption or neglecting heat transfer within a high-speed, multi-stage, axial compressor.</div><div><br></div><div>Preliminary testing of the Purdue 3-Stage (P3S) Axial Compressor Research Facility indicated the presence of heat transfer through stagnation temperature rises across stationary blade rows and higher than expected temperatures on the outside of the aluminum compressor casing, particularly in the front stages. Further experiments performed on the PAX200 compressor in the P3S facility involved a combination of surface temperatures, heat fluxes, and flow stagnation temperatures within the shrouded stator cavities and flowpath. These measurements confirmed that heat transfer was present throughout the stationary components (stators and casing) of the compressor and showed that they could noticeably affect the thermal flow properties within the compressor.</div><div><br></div><div>The influence of the heat transfer through these components was further explored through computational simulations, which showed the importance of incorporating conjugate heat transfer into the model and applying the correct thermal boundary conditions on the outside of the casing. Additionally, the effects on the spanwise temperature of the flow through increased spanwise mixing, convection, and different geometric and material properties of the casing were also explored. Overall, this investigation seeks to establish a correct thermal boundary condition and approach for validation of computational model. It also aims to reconcile the differences between computational models and experimental data by quantifying the impact that heat transfer has on isentropic efficiency for diabatic compressors.</div>