Inductors and transformers constitute two important magnetic components In RF and power hybrids electronic circuitry. Thick film inductors have been subject of extensive research in recent years because they significantly reduce the weight and size, and increase the frequency of operation of electronic circuits. The research work in this dissertation is aimed at the formulation of thick film ferrite pastes and ferrite epoxies and the design, construction, and evaluation of thick film spiral inductors. Wideband characterization (DC - 2GHz) of ferrite pastes, ferrite epoxies, and ferrite substrates is performed using two techniques. These techniques are based on current image and transmission line (coaxial cavity) concepts for low (DC-IOOMHz) and high (50MHz-2GHz) frequency regions, respectively. They are used to evaluate the permeability spectra of formulated and commercially available thick film magnetic materials in respective frequency ranges. A method to numerically calculate the inductance of thick film circular spiral inductors based on modeling the spiral as concentric circles is presented. A novel method for fine as well as coarse tuning of thick film inductors is also introduced. The tunable inductors are constructed using formulated ferrite epoxies and magnetic cores. The method of analysis of variance is used to investigate the variation significance of tunable inductors. Finally, chemical and mechanical properties of developed magnetic materials are discussed. The studied properties include, glass transition temperature, degradation temperature, thermal coefficient of expansion, adhesion, particle-size distribution and particle densification , grain size, and compositional constituents of the magnetic materials. / Ph. D.

The integrated design of a structure and its control system was treated as a multiobjective optimization problem. Structural mass, a quadratic performance index, and the flutter speed constituted the vector objective function. The closed-loop performance index was taken as the time integral of the Hamiltonian. Constraints on natural frequencies and aeroelastic damping were also considered. Derivatives of the objective and constraint functions with respect to structural and control design variables were derived for a finite element beam model of the structure and constant feedback gains determined by Independent Modal Space Control. Pareto optimal designs generated for a simple beam and a tetrahedral truss demonstrated the benefit of solving the integrated structural and control optimization problem. The use of quasi-steady aerodynamic strip theory with a thin-wall box beam model showed that the integrated design for a high aspect ratio, unswept, straight, isotropic wing can be separable. Finally, an efficient modal solution of the flutter equation facilitated the aeroelastic tailoring of a low aspect ratio, forward swept, composite plate wing model. / Ph. D.

Meta-diisopropylbenzene is reacted with propylene over the acid form of the molecular sieves SAPO-5, mordenite, offretite, beta, hexagonal and cubic faujasite (hex and FAU), L, SAPO-37, and an amorphous silica-alumina at temperatures around 463 K in a flow-type fixed-bed reactor. A small amount of cracking is observed. The main reactions of meta-diisopropylbenzene are isomerization and alkylation. This alkylation is proposed as a new test reaction to characterize the effective size of the voids in larger pore (12 T-atom rings or above) molecular sieves by measuring the amount ratio of formed 1,3,5- to 1,2,4-triisopropylbenzene. In most cases, this ratio increases with the increasing effective void size of the molecular sieves in the order: SAPO-5 < mordenite < offretite < beta < hex ≈ FAU < L < SAPO-37 < amorphous silica-alumina. Since samples with the FAU topology show lower selectivities to 1,3,5-triisopropylbenzene than the mesoporous, amorphous silica-alumina, pore curvature has an influence on alkylation selectivity even for voids of 13 A size. / Ph. D.

An investigation was conducted to design instruments to directly measure skin friction along the chamber walls of supersonic combustor models. Measurements were made in a combustor at the General Applied Science Laboratory (GASL) and in the Direct Connect Arcjet Facility (DCAF) supersonic combustor at the NASA AMES Research Center. Flow conditions in the high enthalpy combustor models ranged from total pressures of 275-800 psia (1900-5550 kPa) and total temperatures from 5800-8400 R (3222-4667 K). This gives enthalpies in the range of 1700-3300 BTU/Ib_m (3950-7660 KJ/kg) and simulated flight Mach number from 9 to 13. A direct force measurement device was used to measure the small tangential shear force resulting from the flow passing over a non-intrusive floating element. The floating head is mounted to a stiff cantilever beam arrangement with deflection due to the shear force on the order of 0.0005 in (0.0125 mm). This small deflection allows the balance to be a non-nulling type. Several measurements were conducted in cold supersonic flows to verify the concept and establish accuracy and repeatability. This balance design includes actively controlled cooling of the floating sensor head temperature through an internal cooling system to eliminate nonuniform temperature effects between the head and the surrounding chamber wall. This enabled the device to be suitable for shear force measurement in very hot flows. The key to this device is the use of a quartz tube cantilever with strain gages bonded at orthogonal positions directly on the surface at the base. A symmetric fluid flow was developed inside the quartz tube to provide cooling to the backside of the floating head. Bench tests showed that this did not influence the force measurement. Numerical heat transfer calculations were conducted for design feasibility and analysis, and to determine the effectiveness of the active cooling of the floating head. Analysis of the measurement uncertainty in cold supersonic flow tests show that uncertainty under 8% is achievable, but variations in the balance cooling during a particular test raised uncertainty up to 20% in these very hot flows during the early tests. Improvements to the strain gages and balance cooling reduced uncertainty for the later tests to under 15%. / Ph. D.

The goal of this work is to present an advanced query processing algorithm formulated and developed in support of heterogeneous distributed database management systems. Heterogeneous distributed database management systems view the integrated data through an uniform global schema. The query processing algorithm described here produces an inexpensive strategy for a query expressed over the global schema. The research addresses the following aspects of query processing: (1) Formulation of a low level query language to express the fundamental heterogeneous database operations; (2) Translation of the query expressed over the global schema to an equivalent query expressed over a conceptual schema; (3) An estimation methodology to derive the intermediate result sizes of the database operations; (4) A query decomposition algorithm to generate an efficient sequence of the basic database operations to answer the query. This research addressed the first issue by developing an algebraic query language called cluster algebra. The cluster algebra consists of the following operations: (a) Selection, union, intersection and difference, which are extensions of their relational algebraic counterparts to heterogeneous databases; (b) Normal-join and normal-projection which replace their counterparts, join and projection, in the relational algebra; (c) Two new operators embed and unembed to restructure the database schema. The second issue of the query translation was addressed by development of an algorithm that translates a cluster algebra query expressed over the virtual views to an equivalent cluster algebra query expressed over the conceptual databases. A non-parametric estimation methodology to estimate the result size of a cluster algebra operation was developed to address the third issue described above. Finally, this research developed a query decomposition algorithm, applicable to the relational and non-relational databases, that decomposes a query by computing all profitable semi-join operations, followed by the determination of the best sequence of join operations per processing site. The join optimization is performed by formulating a zero-one integer linear program that uses the non-parametric estimation technique to compute the sizes of intermediate results. The query processing algorithm was implemented in the context of DAVID, a heterogeneous distributed database management system. / Ph. D.

According to the predominant image, applied science is a linear, sequential process, the application of science. First scientists or applied scientists develop knowledge that satisfies the epistemic criteria of science, and applied scientists then find ways to use this certified knowledge to solve society's problems. There is, therefore, a sharp distinction between epistemic or scientific criteria and social criteria. The historical development of the applied ecological discipline called range science or range management demonstrates instead that applied science is a simultaneous process. Range science developed at a time when America increasingly looked to science to solve social, political, and economic problems in the hope that science's ability to predict could provide the basis for organization and rational management. The institutionalization of range science industrialized ranching. Ranchers appealed to a variety of traditional American values in response to this industrialization, but in the new context surrounding ranching those values had become illegitimate. From the outset, range science acquired a dual orientation toward both the epistemic criteria of science and the social criteria of society. That dual orientation introduced a tension into range science because it was not obvious how range scientists should satisfy both sets of criteria simultaneously. Researchers in different institutional contexts developed distinct resolutions to that tension. The most significant difference between the institutions were their political objectives and a difference in the power relations between range researchers and their audiences. Those institutional contexts defined the social criteria and provided the background to judge the acceptability of particular resolutions of the tension, in the process providing the motivation and justification for range science. Nevertheless, range science was not just politics by another means because range scientists also satisfied the epistemic criteria of science. The distinction between epistemic and social criteria therefore did not exist in the historical development of range science because range scientists simultaneously satisfied the epistemic criteria of science and the social criteria that flowed from different political objectives and different power relations between researchers and ranchers. / Ph. D.

The cell extract protein content of acetate- and methanol-grown Methanosarcina thermophila was examined by two-dimensional polyacrylamide gel electrophoresis to determine the extent of regulation by the growth substrate. More than 100 mutually-exclusive spots were present in acetate- and methanol-grown cells suggesting a high degree of regulation. Spots corresponding to acetate kinase, phosphotransacetylase, and the five subunits of the nickel-containing carbon monoxide dehydrogenase (CODH) complex were identified in acetate-grown cells. The nickel-containing methyl coenzyme M methylreductase from acetate-grown M. thermophila was purified 16-fold from a cell extract to apparent homogeneity. The enzyme had a native molecular weight of between 132,000 and 141,000 and contained three subunits with a configuration of a1B1y1-. The as-isolated enzyme was inactive, but could be reductively reactivated by either titanium (III) citrate or reduced ferredoxin. Reactivation with ferredoxin was a simplification over previously reported reactivation systems. ATP stimulated, but was not required for reactivation. The CO dehydrogenase enzyme complex from M. thermophila was purified and separated into its respective components: the CO-oxidizing nickel/iron-sulfur (Ni/Fe-S) component and the cobalt-containing corrinoid/iron sulfur (Co/Fe-S) component. EPR spectroscopy and spectroelectrochemical titration of the Fe-S centers of the Ni/Fe-S component indicated the presence of two low-potential [4Fe-4S]2+/1+ centers and third high-potential center whose Fe-S configuration is unknown. When reduced with CO, the NilFe-S component exhibited a previously unobserved Ni-Fe-C EPR signal. The Co/Fe-S component contained one [4Fe-4S]2+/1+ cluster, and the as-isolated corrinoid in the component was in the base-off conformation suggesting that modulation of the electron density of the cobalt ion may result in a modified reactivity of the active site of the corrin. The CODH enzyme complex and isolated Co/Fe-S component reductively dechlorinated trichloroethylene to cis-dichloroethylene, trans-dichloroethylene, 1,1-dichloroethylene, vinyl chloride, and ethylene. Factor III also catalyzed the dechlorination of trichloroethylene when in the presence of titanium (III) citrate. Reconstitution of the Co/Fe-S component with the CO-reduced NilFe-S component also allowed dechlorination demonstrating an electron transfer from the reduced Ni/Fe-S component to the Co/Fe-S component. / Ph. D.

Men's emotional expression was assessed using Deaux and Major's (1987) interactive model of gender-related behavior as a theoretical framework. This model explains gender differences in behavior as a function of proximal forces and contextual variables such as, activated gender-related schemata regarding oneself and others, and situational cues. Male college students, categorized as high and low on the Masculine Gender Role Stress (MGRS) scale (Eisler & Skidmore, 1987), interacted consecutively with a male and a female confederate. Confederates portrayed either gender-consistent (GC) or gender inconsistent (GI) cues regarding their desire for emotional expression from subjects. Verbal and nonverbal measures were rated from videotapes of the interactions. Speaking and listening roles were analyzed separately. It was hypothesized that men who appraise violations of the traditional masculine role as stressful (high MGRS) would demonstrate less emotionally expressive behavior than other men (low MGRS). Specifically, under GC cue conditions (i.e., emotional expression more appropriate to female than male confederates), high MGRS men were expected to be more expressive to female expressive to both confederates. Under GI cue conditions (i.e., emotional expression more appropriate to male than female confederates), it was hypothesized that low MGRS men would become more expressive to male than female confederates, while high MGRS men would be equally expressive to male and female confederates. Results indicated that under GC conditions, both high and low MGRS men were more expressive to female than to male confederates. As predicted, under GI conditions, this pattern was attenuated or reversed, confirming that contextual variables impact displays of emotional expression. Furthermore, anxiety expression also varied with cue conditions and MGRS level. Verbal results demonstrated support for the attenuation of expressive differences under GI conditions, but this did not vary as a function of MGRS level. Patterns of expression varied as a function of speaking and listening roles, particularly for low MGRS men. This study lends support to the Deaux and Major's hypothesis that gender-related behaviors are influenced by contextual and proximal factors. Implications for this model, as well as the MGRS construct, are discussed. / Ph. D.

Polyrotaxanes are novel polymer architectures consisting of theo components. One component is the macrocycel consisting of 24-60 atoms; it is threaded by he second component, i.e., the linear backbone polymer. / Ph. D.

A rapid scanning square wave voltammetric detector has been developed for use with high performance liquid chromatography.The electrochemical cell used in the detector was designed so that the HPLC effluent flows through the center of a large diameter platinum disk electrode and is then forced to flow radially across the electrode surface. The arrangement of the electrodes in the cell was intended to result in large analytical currents while minimizing electrical resistance and analyte band spreading in the detection zone. The detector was evaluated in terms of its minimum detectable quantity, linear dynamic range, electrochemical efficiency, and analyte band spreading. The MDQ was found to be in the low parts per billion range for hydroquinone. The detector was shown to provide data that is qualitatively superior to data obtained by amperometric detection and was shown to be compatible with gradient elution HPLC over a broad range of solvent compositions. A sensor based on the quartz crystal microbalance was also developed for use in flowing solvent streams. Quartz crystals were treated with various compounds to produce close - packed monolayer coatings which could interact with solutes entering the flow cell. The solute capacity was determined for one of the monolayer coatings and various factors that influence the magnitude of the OCM signal were investigated. These factors include the solvent flow rate, the solvent strength, solute molecular structure, and bonded phase molecular structure. The QCM sensor was found to be a convenient probe for conducting surface adsorption studies and the molar free energy of adsorption was determined for some chemically related solutes on an amine modified crystal. / Ph. D.