This dissertation examines ways in which differences in states' political activity laws affect the political attitudes and reported behavior of senior state government employees. Of particular concern is whether a stringent little Hatch Act engenders any "chilling effects" that may lead these workers to shy away from permissible political activities. The study included officials employed in Pennsylvania, which has a restrictive political activity statute, and New Jersey, which has generally permissive laws. Mail questionnaires were sent to 962 officials, 512 from Pennsylvania and 450 from New Jersey. Responses were received from 582 employees, yielding a 61.91% response rate. Compared to New Jersey officials, those from Pennsylvania were less knowledgeable about their state's political activity laws. The Pennsylvania employees also reported being less politically active and less satisfied with their activity, and were more likely to indicate that they would increase their level of political activity if state prohibitions were eliminated. However, compared to their New Jersey counterparts, these officials were no less inclined to engage in permissible political activities. This finding casts doubt on the notion that a highly restrictive statutory climate spawns chilling effects. / Ph. D.

In this research, I study the unintended consequences of implementing information technology. Understanding the causes of these unintended effects is important because information technology is ubiquitous in the modern economy. I used three research protocols to study this phenomenon. The first approach was a literature review to explore and understand what was already written on the subject of implementing information technology. The second approach was an experiment using the beer distribution game to study the implementation of information technology. The third approach I used was a case study in which I used system dynamics modeling to study the information technology in an engineering and architecture firm. I tested the implementation of information technology in the beer distribution game by modifying the play with a change that simulated implementing information technology. I compared the performance of test subjects with control groups that played the game at the same time, without the modification. I also compared the subjects' performance against the performance of trials first published in 1989. I hypothesized that implementing information technology would result in an immediate improvement of the teams' performance. The results of implementing information technology in the beer distribution game were not as expected; implementing information technology did not improve performance. When it became clear that my experimental hypotheses were incorrect, I went back to the literature to see if there was an explanation for this failure that could be derived from the literature on the beer game. I studied the information technology in the case study firm in order to extend the learning from the experimental research. The results of the experiment were not as I expected; I learned a great deal about the effect of information technology in a very controlled experimental setting. By expanding the research to include a case study I was able to explore the behavior in a more realistic environment. The beer distribution game provided me with an unexpected insight into the alignment of users mental models and the structure of the organization. The case study was completed using system dynamics tools to model, and then simulate, the effect of misalignment in a real world organization. Considering the results of the beer distribution game and the case study, I suggest that one explanation for the unintended consequences of implementing information technology is the misalignment of users' mental models with the altered structure of the organization after information technology is implemented. / Ph. D.

Coping with droughts involves two phases. In the first phase drought susceptibility of a region should be assessed for developing proper additional sources of supply which will be exploited during the course of a drought. The second phase focuses on the issuance of drought warnings and exercising mitigation measures during a drought . These kinds of information are extremely valuable to decision making authorities. In this dissertation three broad schemes i) time series modeling, ii) Markov chain analysis, and iii) dynamical systems approach are put forward for computing the drought parameters necessary for understanding the scope of the drought. These parameters include drought occurrence probabilities, duration of various drought severity classes which describe a region's drought susceptibility, and first times of arrival for non drought classes which signify times of relief for a drought-affected region. These schemes also predict drought based on given current conditions. In the time series analysis two classes of models; the fixed parameter and the time varying models are formulated. To overcome the bimodal behavior of the Pallner Drought Severity Index (PDSI), primarily due to the backtracking scheme to reset the temporary index values as the PDSI values, the models are fitted to the Z index in addition to the PDSI for the forecasting of the PDSI. / Ph. D.

Minimally disturbed virgin forest soils in the Little Santeetlah Creek (LSC) watershed of western North Carolina were sampled along with soils from the adjacent disturbed Slickrock Creek (SRC) watershed. Soils with similar elevation/landform/vegetation/parent material characteristics were initially sampled at nine random locations each on north and south aspects within each watershed with a soil push probe. Some differences in parent materials were noted on south aspects (metasandstone vs. phyllite), but parent materials under north aspect soils were identical (metasandstone). Soils in LSC were significantly deeper and relatively free of solum coarse fragments while SRC soils were shallower and higher in coarse fragments. Subsequent auger observations of three typical pedons on each aspect indicated that soils in LSC were well-developed with gradual horizon boundaries and common diffuse transition horizons, while soils in SRC were more compact in horizonation and lacked diffuse transitional horizons. Vegetation communities were similar across both watersheds, except that SRC south sites were higher in Pinus spp. Litter layer morphology differed strongly between the two watersheds. Specifically, well-developed humus (H) layers were typical in LSC, but completely absent in all typical pedons described in SRC. Data obtained from these two watersheds indicate strong differences in surface soil (O + A horizon) properties between the two. These observed differences could be due to differential anthropogenic effects, particularly logging and associated erosion in the early 1920's. However, further study over multiple disturbed watersheds in the region, and of the distribution of sediments and colluvium within them would be required to test this hypothesis. / Master of Science

As lower microwave frequency bands become saturated with users, there is a motivation for the research of applications that utilize higher frequencies, especially the 60 GHz band. This band is plagued with high atmospheric absorption due to atmospheric oxygen, but has a lot of bandwidth, which makes it desirable for multi-media applications. Recently, research of wideband digital links within the 60 GHz band gained the interest of the wireless communication industry when the FCC announced that a license is not required for a wideband digital signal in this band. Previous research on 60 GHz signals focused on how much attenuation due to atmospheric oxygen exists in the link. But a look at the physical properties of atmospheric oxygen reveals both the reason why atmospheric oxygen absorbs electromagnetic waves and how pressure affects atmospheric oxygen. Atmospheric oxygen resonates at 60 GHz due to transitions between its three closely spaced rotational states. These transitions, combined with the magnetic dipole moment of atmospheric oxygen, cause attenuation and phase dispersion in electromagnetic waves. At lower pressures, the individual resonance lines of atmospheric oxygen appear in the attenuation and the phase dispersion plots. As pressure increases, the resonance lines broaden and contribute to neighboring resonant lines. The effect of attenuation and phase dispersion in a wideband signal becomes greater at lower atmospheric pressures, which results in signal distortion. The signal distortion leads to more bit errors and results in the presence of inter-symbol interference (ISI) in the received signal. This thesis aims to analyze the effects of atmospheric oxygen on a wideband digital link, especially at lower pressures and higher data rates. In order to simulate the effects of atmospheric oxygen in the atmosphere, an empirical atmospheric model was used, which characterizes the behavior of oxygen under various atmospheric pressures. A wideband communication system was simulated with the absorption and dispersion due to atmospheric oxygen represented as a transfer function and placed in the link part of the system. Eye diagrams were used to view the impact of the atmospheric oxygen attenuation and phase dispersion in the signal. Also bit error rate plots were computed in order to determine the extra margin needed. / Master of Science

No / Free surface flows of practical relevance in many engineering problems are almost always turbulent. In this paper, a numerical model to compute the free surface flow with turbulent effects is presented. The shallow water equations together with a k-ε turbulent model are discretized and simulated using a MUSCL-HANCOCK finite volume scheme. The proposed 2D k-ε shallow water model calculates the depth-averaged quantities such as water depth and velocity profile. The depth-averaged turbulent viscous stresses are determined from the depthaveraged version of a traditional 3D k-ε turbulent model. The numerical model is applied to a flow within channels that contain full depth obstructions. The k-ε turbulent model results are compared with existing Direct Numerical Simulations (DNS) predictions and show a high level of accuracy.

The effect of surface finish on the transfer of polychlorotrifluoroethylene (PCTFE) to mild steel was studied using a radio-tracer technique. A pin-on-disk apparatus was used in conjunction with neutron activation of PCTFE to study the initial stages of transfer. Quantitative transfer and friction data were obtained as functions of surface finish and the number of repeated passes of polymer over mild steel. Qualitative supporting evidence for postulated transfer mechanisms was obtained using scanning electron microscopy. The results showed that bulk transfer of PCTFE to mild steel does occur at room temperature. Initial transfer to polished (0.10 um - rms) surfaces, abraded (0.81 um - rms) surfaces, and glass bead blasted (1.73 um - rms) surfaces was attributed to an abrasive wear mechanism. An apparent translation to adhesive wear was observed during later stages of transfer. This transition occurred much sooner with the polished surface than with the rough surfaces. This work also demonstrated that a radio-tracer technique could be effectively applied to the study of polymer wear. The minimum mass detection limit with this technique was 0.3 ug. This sensitivity is at least one order of magnitude better than that obtained with reported polymer wear measurement methods. / Master of Science

This thesis is concerned with the effects of earthquakes on partially-filled water tanks. The analysis is applicable to rectangular water tanks, which have received little attention to date. The analysis is relatively involved and includes the derivation of the equations of motion for the vibration of the whole of tank by means of substructure synthesis, a stochastic analysis relating the random ground motion caused by earthquakes to the random vibration of the tank, a stochastic characterization of the fluid pressure and computation of the probability of failure of the tank. / Master of Science

The purpose of this project was to study the effects of anodic electrically stimulated silver-coated stainless steel implants and bacterial contamination in a canine radius fracture gap model. Twelve skeletally mature canines weighing 19.2-23.2 kg were used. Dogs were randomly assigned to into control and contaminated groups. A 5 mm ostectomy gap was made in both radii of each dog. One radius of each dog was stabilized with a silver-coated stainless steel bone plate and the other with an uncoated stainless steel bone plate. The ostectomy sites were inoculated with sterile PBS in 6 dogs and S. intermedius in the other 6 dogs. Each implant set was electrically stimulated with direct current for 20 minutes daily, for 10 days. Animals were treated with Cephalexin orally for 10 days. Radiographs were obtained at two week intervals. Animals were euthanized at 12 weeks and each plate was cultured. Radiographic, histologic and bacteriologic evaluations of each radius were performed. The difference in bone healing between silver-coated and stainless steel treated radii was determined for each dog by subjective radiographic evaluation and quantitative analysis of radiographic density using commercial software. At week 12, a significant decrease in bone healing was found on radiographic evaluations and quantitative bone area analysis of contaminated radii that were treated with electrically stimulated silver-coated implants (p-value 0.025 and 0.018 respectively). Inoculum or implant treatment type showed no significant difference on radiographic evaluations or quantitative bone area analysis. No significant differences were detected in radiographic evaluations of osteomyelitis or histologic evaluations of bone healing, inflammation and peri-implant resorption. Culture results were not indicative of S. intermedius inoculated osteomyelitis. The use of a bilateral radial ostectomy model allowed comparison of electrically stimulated silver-coated and uncoated implants within each dog. Bone healing in the stable 5 mm fracture gap radial ostectomy model, was progressive in both contaminated and non-contaminated situations. Our study found a negative effect on bone healing when electrically-stimulated silver stearate coated implant were used in S. intermedius contaminated radius ostectomies. This trend became apparent at 6 weeks post-operatively, but was not statistically evident until 12 weeks. Further studies are warranted to evaluate the appropriate protocol, the effects of, and indicated use of this treatment modality in contaminated fractures and clinical osteomyelitis situations. / Master of Science

Skim, sweet buttermilk, and butter-derived aqueous phase components were used to re-emulsify low-melt butteroil into creams with a desired 20% milkfat. The implications of pasteurization process, homogenization sequence, and formulation on the physicochemical properties of reformulated and natural creams were investigated. Creams homogenized prior to pasteurization had significantly (p<0.05) greater amounts of milkfat surface material per gram of cream and per gram of lipid compared to creams homogenized after pasteurization. Significantly (p<0.05) higher percentages of available phospholipid also were associated with the milkfat surface material of creams homogenized prior to pasteurization. Phosphodiesterase, a marker enzyme within the native milkfat globule membrane, was in significantly (p<0.05) higher activity relative to protein on lipid globule surface when cream was homogenized prior to pasteurization. Creams that underwent pasteurization prior to homogenization had significantly (p<0.05) higher protein load associated with the milkfat surface material. Natural cream homogenized prior to pasteurization had significantly (p<0.05) greater milkfat surface material per gram lipid than natural cream homogenized after pasteurization and buttermilk / aqueous phase (AP) reformulated cream homogenized after pasteurization. In contrast, natural cream homogenized after pasteurization and BM / AP reformulated cream homogenized after pasteurization had significantly (p<0.05) greater amounts of protein per 10 mg of milkfat surface material than all other formulation / homogenization sequence combinations. In addition, natural cream homogenized prior to pasteurization, and skim milk (SM) reformulated cream pasteurized prior to or after homogenization had significantly (p<0.05) higher percentages of available phospholipid associated with the milkfat surface material than natural cream homogenized following pasteurization. Pasteurization temperature had a significant (p<0.05) effect on apparent viscosity of natural and reformulated creams. All UHT pasteurized natural and reformulated creams had significantly (p<0.05) greater apparent viscosities at all shear rates monitored than HTST pasteurized natural and reformulated creams. At a failing curve shear rate of 692 s-1 UHT pasteurized cream reformulated with BM / AP had significantly (p<0.05) greater viscosity than UHT pasteurized natural cream and cream reformulated with skim component. HTST pasteurized natural cream had significantly (p<0.05) greater viscosities than HTST pasteurized cream reformulated with skim component. Moreover, at a shear rate of 2769 s-1 and a rising shear rate of 1384 s-1 HTST pasteurized natural cream had significantly (p<0.05) greater viscosity than HTST pasteurized cream reformulated with buttermilk and aqueous phase. Creams formulated with skim component showed significant differences in creaming stability after 7 days of storage. On the other hand, natural cream and cream reformulated with buttermilk and aqueous phase showed significant differences in creaming stability after 9 days of storage. HTST pasteurized creams had greater creaming stability than UHT pasteurized creams. All creams feathered in a pH range of 5.09 to 5.31. Homogenization prior to UHT pasteurization resulted in creams rated "out of specification" because of poor sensory quality on day 1. Other processing sequences resulted in creams within sensory specifications. / Master of Science