Tumor necrosis factor-a (TNFa) is primarily a macrophagederived cytokine. TNFa, in vitro, kills or inhibits growth of approximately one third of surveyed transformed cell lines dincluding the L929 and WEHI 164 murine fibrosarcoma cell lines. Very little is known about the mechanisms of TNFa action. However, recently, it has been theorized that TNFa has no activity of its own and that the receptor for TNFa on the cell surface, when properly triggered, activates the cellular mechanisms which may result in the cell's death. The objective of this study was to produce an antiidiotypic antibody to TNFa to be used as a tool to study the mechanisms of TNFa action. A hybridoma that secretes an antiidiotypic antibody to TNFa (Ab2J1) has been produced and isolated following standard procedures. This antibody was found to be of isotype IgG2a as determined by an indirect ELISA test. The Ab2J1 exhibited TNFa target cell-killing capabilities in vitro. The TNFa-resistant cell lines, SP2jO and NS-1 were resistant to Ab2J1 and TNFa sensitive cells, L929 and WEHI 164, were sensitive to Ab2J1. The cell killing activity of both TNFa and Ab2f3 could be neutralized by a monoclonal anti-TNFa antibody. Both TN Fa and Ab2f3 acted in parallel having an effect on the killing of Brucella abortus strain RB51 by peritoneal macrophages, whereas neither TNFa nor Ab2f3 had an effect on the killing of strain 2308 by macrophages. These results, again indicate that TNFa and Ab2f3 have parallel dbactericidal effects and that Ab2f3 is capable of mimicking TNFa activity. The Ab2J1 was further characterized by gel electrophoresis and Western blot and was found to have two subunits of 25 and 50 kDa molecular weights similar to IgG. This anti-idiotypic antibody to TNFa may help in understanding the mechanisms of the cytotoxic activity of TNFa. / Master of Science

Causes for the differences in precipitation morphology observed and investigation. / Master of Science

A peninsular power company's extra high voltage (EHV) transmission grid and the rest of the country behave as a two machine system for the following two types of disturbances loss of a large generator in the southern region of the peninsular power company faults on the 500 kV interconnections between the two systems Whether the two systems will remain stable relative to each other or go unstable depends on the following three factors • severity of the disturbance • loading on the peninsular power company's EHV transmission grid • amount of power imported from the rest of the country For stable oscillations the two systems must remain coupled at them 500 kV interconnections. For separations the two systems should be immediately isolated from one another at their 500 kV interconnections. Since these two systems behave as a two machine system for these two types of disturbances the extended equal area criterion(EEAC) is used to make an extremely quick and accurate prediction of the relative stability between them. For stable oscillations following a disturbance, circuit breakers at the 500 kV interconnections are blocked from tripping. For separations these circuit breakers are tripped. EEAC requires synchronized voltage phasor measurements at two specific locations within the overall electrical power system. The two sites are substations located on opposite sides of the electrical center of the two systems. The voltage angle at each location's electric bus will swing with respect to its equivalent machine. This information is constantly recorded to monitor the relative stability of the overall system. When a disturbance does occur, a prediction is made and the appropriate control actions are issued. / Master of Science

This thesis presents the results of a study on the blends of an aliphatic crystallizable polyamide (nylon 6/6) and trace quantities of a polar non-crystallizable diluent (poly(vinylpyrrolidone)). This study is based on the preliminary findings of Keith et al. who reported striking morphological changes in nylon 6/6 upon addition of small amounts of poly(vinylpyrrolidone) (PVP). The melting behavior of pure nylon 6/6 was also studied during the course of this investigation. The melting behavior of nylon 6/6 was studied using a differential scanning calorimeter (DSC). Samples were isothermally crystallized at various temperatures from the melt. Subsequent DSC analysis showed the presence of three distinct melting endotherms. The behavior of these three endotherms was studied as a function of the crystallization temperature (T_C), annealing time, and DSC heating rate. X-ray studies (small and wide angle) and hot stage optical microscopy studies were also carried out to determine the cause of the multiple endotherms. The influence of addition of PVP on the crystal morphology of nylon 6/6 was studied using DSC, x-ray and hot stage photomicroscopy. The addition of PVP has a dramatic effect on the spherulitic morphology of nylon. The addition of PVP to nylon caused a striking reduction in the nucleation density of spherulites, modification of lamellar organization in spherulites (as evidenced by the occurrence of banding), and modification of interlamellar spacings. / Master of Science

An air conveying system uses pressurized air as a propelling force to lift and move articles. It is supplied by a fan into a plenum with a top surface that is a flat perforated plate. Air escapes through the openings, creating a layer that supports and drives the articles along. This thesis provides information on the lifting and moving forces. It summarizes the results of both analytical and experimental studies. Most of the effort is focused on an experimental procedure for measuring the actual forces on the objects being conveyed and data are used to verify the analytical models. The experiments are limited to straight holes and louvers located under the bottom of aluminum concave-bottom cans. In some tests, a flat disc has been fixed to the bottom of the cans. Measurements are made of the can motion on an actual section of conveyor. / Master of Science

The effects of genetic and social factors influencing ingestive behaviors, growth, livability, and dietary self-selection were investigated in three experiments. In Experiment I, ingestive behaviors, livability, and body weight were measured in lines of White Plymouth Rock chickens selected for high (HW) and low (LW) juvenile body weight reared in cages and floor pens as line-separate (S) and line-intermingled (I) flocks in three replicated trials. Body weights of Line HW chicks in cages, livability of Line LW chicks in cages, and ingestive behaviors of Line LW chicks in floor pens were higher in I than S flocks. Experiments II and III were designed to determine the ability of young chicks to discriminate among diets differing in amino acid content. In Experiment II, growth, feed intake, and feed preferences for diets varying in content of lysine, methionine, or tryptophan were measured in Line HW and a line of White Leghorns (HA) selected for high antibody response to sheep erythrocytes. Chicks were fed one of seven diets which were either balanced (Diet A), or slightly (1) or moderately (2) deficient in lysine (L), methionine (M), or tryptophan (T) for seven days. Chicks were then offered a choice between Diet A and the diet fed for seven days (3 to 10 days of age). Line HW chicks eventually showed a consistent preference for Diet A to all but Diet L1. For diet preference, interactions between time and diet were common in Line HW and the causes of these interactions were discussed. Line HA chicks preferred Diet A to M2, but otherwise did not choose between diets. Growth of Line HW chicks was reduced by feeding Diets L2, L1, and M2, but growth was not affected in Line HA. In Experiment III chicks from Lines HW, HA, and LW were provided a choice among diets with .85, .58, and .44 % methionine from one day of age. Line HW discriminated among diets with different methionine content from five days of age, but chicks did not make a consistent choice until after a period of deficiency. After a period of deficiency, Line HW chicks consistently chose the diet with .85 % methionine. Line HA chicks consumed more of the diet in slight excess of their methionine requirement and the reason for this is not clear. Line LW chicks did not discriminate among diets at any time during the trial. These results indicate that several factors interact to influence ingestive behaviors, growth, livability, and dietary self-selection in different genetic lines of chickens. / Master of Science

The inososes are a group of compounds, containing six-membered rings that have five hydroxyls (four for the deoxyinososes) and a carbonyl. Due to the relative ease of their reduction to inositols, a study aimed at the potential preparation of these useful natural products was undertaken. The constitution of the hydroxyls shows that either the α or β face can react with an appropriate reducing agent, such as Raney Ni/H₂, to yield the expected inositol. It has been shown by others that, by using Raney Ni/H₂ as the reducing agent equilibrium between the two chair conformations can be established and the carbony! can be reduced stereoselectively. This is shown in the example below for allo-1-inosose: [See figure] Molecular modeling with PCMODEL© which invokes MMX calculations was performed to permit a distinct prediction of the course and the stereochemical outcome of the reduction of the inososes. Several inososes and deoxyinososes were modeled to demonstrate the ability of MMX calculations to predict the stereochemical outcome of the reduction. Based on the results of molecular modeling, which include the heats of formation, and the strain energies, the lowest energy form was determined for each inosose and deoxyinosose. With the lowest energy form predicted, stereochemistry of the inositol or deoxyinositol product was predicted. In one case, a comparison with known experimental results was made. / Master of Science

This thesis deals with the analysis of a discrete equal-capacity p-median problem, where the costs are directly proportional to the shipping distance and the amount shipped. A mixed integer programming formulation of the unbalanced, but equal capacitated case is analyzed. First we develop a dynamic programming procedure for a p-median problem on a chain graph. In the second part we develop an algorithm to solve a p-median problem on a general network. First a heuristic algorithm is used to obtain an upper bound on the problem. Next, we obtain a lower bound on the problem by solving a Lagrangian relaxation of a reformulated problem via a conjugate subgradient optimization procedure. We obtain Benders’ cuts from the above procedures and proceed to a modified Benders’ approach to solve the continuous relaxation of the original problem. Finally a branch-and-bound algorithm that enumerates over the location decision variable space is used to obtain an integer optimal solution. Computational experience is provided to demonstrate the efficacy of the algorithm. / Master of Science

The composition of the population of undergraduate students in the U. S. has changed dramatically in recent years. A number of factors including societal transformations, a changing economy and demographic trends of the past decade have had particular impact. The cohort of students over age 30 is now the fastest growing segment of students who are entering or returning to colleges and universities. At this age the mature student is generally well established in work, community and family. While much of the research has focused on individual student needs, it has failed to investigate family and education interactions among older married reentry students. This is despite the reality that family concerns are often cited as the primary reason a reentry student withdraws from school. In this study, stepwise multiple regression was used to determine the extent to which gender, demographic background, and family issues explain the variance in reentry student perception of reentry student problems. This analysis yielded results which support the thesis that regardless of the student's gender, family problems are the strongest predicator of reentry student problems. Implications from this study may provide invaluable information to counselors, student service professionals, administrators, educators, and other professionals who work with reentry students and their families. This information can help to dispel myths and to aid reentry student and family adjustments. / Master of Science

A piezoceramic actuator used for structural control behaves electrically as a nearly pure capacitance. When conventional amplifiers are used to drive these actuators, the current and voltage is close to 90 degrees out of phase. This causes the power factor (PF) of the load to be close to zero and results in excessive power requirements. This thesis reports the results of a study of the following question: What effect does applying power factor correction methods to piezoceramic actuators have on their power consumption characteristics? A subproblem we explored was to detennine the qualitative relationship between the power consumption of a piezoceramic actuator and the damping that actuator added to a structure. To address the subproblem, a feedback control experiment was built which used a ceramic piezoceramic actuator and a strain rate sensor configured to add damping to a cantilevered beam. A disturbance was provided by a shaker attached to the beam. The power consumption of the actuator was determined by measuring the current and voltage of the signal to the actuator. The energy dissipated in the beam by the feedback control loop was assumed to be modeled by an ideal structural damping model. A model relating structural damping as a function of the apparent power consumed by the actuator was developed, qualitatively verified, and physically justified. Power factor correction methods were employed by adding an inductor in both parallel to and in series with the piezoceramic actuator. The inductance values were chosen such that each inductor-capacitor (LC) circuit was in resonance at the second natural frequency of the beam. Implementing the parallel LC circuit reduced the current consumption of the piezoceramic actuator by 75% when compared to the current consumption of the actuator used without an inductor. Implementing the series LC circuit produced a 300% increase in the voltage applied to the actuator compared to the case when no inductor was used. In both cases, employing power factor correction methods corrected the power factor to near unity and reduced the apparent power by 12 dB. A theoretical model of each circuit was developed. The analytical and empirical results are virtually identical. The results of this study can be used to synthesize circuits to modify piezoceramic actuators, reducing the voltage or current requirements of the amplifiers used to drive those actuators / Master of Science