The gluconobacters are well known for their plasma membrane-bound dehydrogenases that rapidly oxidize compounds and release the products into the medium. In 1989, Qazi et al. proposed that genes coding for membranebound glucose dehydrogenase are on a plasmid in G. oxydans strain ATCC 9937. The only other known report of gluconobacter plasmids was by Fukaya, et al. who reported that 23 of 36 strains examined contained plasmids. I wish to learn more about the presence and significance of plasmids in the gluconobacters. In this study, I selected 14 strains representing the three gluconobacter species to determine possible similarities and differences in their plasmid profiles. To date, our most successful method for extracting plasmids involves alkaline lysis of cells at 60°C followed by phenol-chloroform extraction which leaves the nucleic acids in the aqueous phase. These nucleic acids are then precipitated in a LiCl-ethanol solution using glycogen as a carrier, and plasmids are separated on agarose gels. We found that 11 of the 14 gluconobacter strains surveyed contain plasmids ranging in size from 2.7 to greater than 200 kb. The type strain of the genus (G. oxydans strain ATCC 19357) contained 6 plasmids ranging in size from 4 to 120 kb. Strains from G. frateurii and G. asaii also contained a wide range of plasmid sizes. Hybridization techniques were utilized to determine if plasmids of similar size are genetically similar. The 2.7 and 16.2 kb plasmids of G. oxydans strain ATCC 621 and IFO 12528 were shown to share homology. The 100 and 120 kb plasmids of G. oxydans strain ATCC 19357 hybridized with the 250 kb plasmids of ATCC 621 and the 210 kb plasmid of ATCC 9937. Also showing homology were the 6.4 kb plasmids of G. oxydans strains ATCC 9937 and IFO 12467. / Master of Science

In recent years, the field of transportation engineering has witnessed the emergence of technological innovations linking several different application areas like human factors, computer science, communications and operations research. This research deals with automatic freeway traffic operations including ramp guidance and merging which is an important aspect of Intelligent Vehicle Highway Systems (VHS) Technology. An existing traffic flow model is utilized to generate a non-overtaking, continuous traffic stream with automatic acceleration/ deceleration characteristics of the smart cars to fulfill the needs of a high-speed flow under controlled headway and optimized density conditions. The orientation, shape, and geometry of such ramps on a high-speed highway system is investigated. It is proposed that the angle between the ramp and highway would be very acute and lane changes from acceleration lane to the cruising lane would follow a smooth trajectory. The curve would be composed of two circular curves of large radii of curvature or two spiral curves in succession. The adequacy of the existing geometric design specifications are questionable, not only for the merging section, but the entire stretch of the "smart highway”. The introduction of intelligent highway network extensively in rural areas could necessitate a complete rethinking about highway geometric design standards. An alternate method of geometric design requirements is undertaken to explore the applications of vehicle aerodynamics’ principles to the highway design, which is perceived to be essential under the high-speed conditions. The results obtained can be compared to those of the conventional geometric design formulae to yield a comparison. Though the principal aim of this research is to serve the highways, it has applicability to other forms of highspeed, controlled guideway transportation systems also. / Master of Science

Constrained layer damping (CLD) for three layer beams with viscoelastic cores and aluminum or graphite/epoxy composite laminate outer layers was investigated for model comparison, sensitivity to design parameters, and evaluation of experimental loss factor estimation techniques. Model comparison for damping estimation and resonant frequency prediction was performed between finite element analysis (FEA) Ross, Kerwin, and Ungar theory (RKU), developed moment predicted loss factor, and experimental results. Investigated design parameters include; treatment application length and placement, relative thickness of core and constraining layers to base layer, core loss factor, and boundary conditions (free/free, fixed/fixed, and cantilever). Experimental damping estimation techniques evaluated include; frequency response function (FRF) based methods of component analysis, circle-fit method a curve-fit algorithm developed by Han [30] and the time domain of log decrement. Model comparison of finite elements to experimental results showed good trend prediction correlation. Only fair prediction of absolute loss factors was achieved, possibly due to the difficulty in characterization of viscoelastic properties. Design parameters analysis showed that treatment application length and placement were critical to effective added damping. In one case, for the same amount of damping material, the effective added damping of a well designed application was seven times greater than that of a poorly considered one. The effectiveness of treatment on a region appears to be strongly related to the magnitude on the moment acting on that region. Parameter analysis also showed that although a symmetric beam realizes the highest damping, in most cases near optimal damping can be obtained with constraining layer one half as thick as the base layer. Experimental methods for damping estimation showed the simple FRF component analysis to be consistent with the other methods (experimental and FEA) and the most computationally efficient. / Master of Science

The primary research objective of this thesis was to functionalize bifunctional cationic living poly(tetramethylene oxide) (PTMO) with m-aminophenoxide to produce aromatic amine telechelic PTMO of controlled molecular weight and narrow molecular weight distribution. TrifHc anhydride was used to initiate a bifunctional cationic living polymerization of tetrahydrofuran (THP). An anhydrous solution of m-aminophenoxide was used to terminate the polymerization, which resulted in aromatic amine telechelic PTMO of controlled molecular weight. The order of addition of the m-aminophenoxide to the living PTMO was found to be crucial. In order to produce linear aromatic amine telechelic PTMO, the living PTMO must be charged to the m-aminophenoxide solution. The aromatic amine telechelic PTMO was characterized using IR spectroscopy, 1 H NMR spectroscopy, HBr titration and 19p NMR spectroscopy. Trifluoroacetic anhydride was reacted with the m-aminophenoxide terminated PTMO to serve as a fluorine tag, then analyzed using 19p NMR spectroscopy to dquantify the amount of hydroxy end groups present (if any) relative to primary amine end groups. In order to compare 19p NMR spectra, the model compounds m-phenetidine (Model NH2) and 3-dimethylaminophenol (Model OH) were also reacted with trifluoroacetic anhydride and analyzed using 19p NMR spectroscopy. The 'aromatic amine telechelic PTMO may be further reacted in a step growth polymerization to form segmented block copolymers. PTMO segments show promise serving as flexible low T g blocks between reinforcing high T g blocks such as polyamides, polyurea copolymers and epoxies, and may act to toughen these types of materials. / Master of Science

Automation of the process planning function is necessary for the effective linking of Computer-Aided Design (CAD) and Computer-Aided Manufacturing (CAM). Before automated process planning is performed, primitive geometric data from CAD databases needs to be converted to higher-level feature information required by the CAM systems. Many feature recognition algorithms have been developed to extract geometric features from different CAD representation schemes. However, the algorithms are CAD modeler dependent. This research addresses the problem of developing a standardized file format, Complete Geometric and Topological File Structure (CGTS), for feature recognition purposes. Algorithms for conversion of 3-D wire-frame data to CGTS format have been developed, using C++, and the process of feature recognition demonstrated using the CGTS file format. / Master of Science

Precommercial thinning of 12-year-old upland oak stump-sprouts in southwestern Virginia using herbicides and manual felling was compared. Objectives were to quantify and compare residual crop-stem growth and treatment costs between treatments and application methods. 2,4-D and triclopyr were applied to competing stump-sprouts using stem injection and low volume basal spray techniques. Kerosene, the carrier for the ester formulations, was also tested for its efficacy properties. One growing season following treatment, total control (percent affected and dead) of chemically treated sprouts averaged 98 percent. Triclopyr basal spray treatment exhibited the highest mortality to treated sprouts totaling 88.6 percent and kerosene had the lowest mortality occurrence of 7.6 percent. On average, translocation was minimal affecting only 58 percent of the crop-stems with less than 10 percent of the crown exhibiting visual symptoms. Mortality of residual crop-stems did not occur and an average of 36 percent exhibited no visual symptoms. Mean height growth for residual crop-stems was significantly greater for manual thinning over unthinned control. Crop-stem height growth was also significantly greater for the contrasts of manual thinning vs chemical thinning and manual thinning vs basal spray treatments. No significant differences occurred for any growth parameter between unthinned control and chemical treatments nor between injection and basal spray treatments. Results of regression-adjusted volume growth (D²H) showed that a 2 percent increase in growth over control was realized for the crop-stems following injection treatments versus a 1 percent increase as a result of the basal treatments. The manual thinning treatment was found to exhibit a significantly greater effect on crop-stem growth compared to chemical treatments averaging a 4 percent volume growth increase. Chemical treatment costs ranged from $36.05/ha to $82.23/ha for 2,4-D injection and triclopyr basal spray treatments, respectively. Manual thinning was found to be the most expensive treatment at $105.30/ha. Injection treatments were significantly more productive and the least expensive. Application costs incurred during the present study were representative of costs incurred by forest industry, private, and public agencies in the southern United States. Overall results of this study suggest that chemical pre-commercial thinning of oak stump-sprouts is a safe, cost effective method of reducing competitionand releasing dominant crop-stems. / Master of Science

The objective of this project was to develop a physically realistic method for predicting the flowrates in short tubes. A physically realistic model, though based on tests with one refrigerant, could be extrapolated to other refrigerants and to other refrigeration systems. Most of the existing methods of predicting flowrates are achieved by doing a lot of experimental work and developing empirical or semi-empirical relations; because of the high degree of empiricism they are only valid for the refrigerant used in the experiment. Eliminating material constraints and high degrees of empiricism from the prediction model was considered as a matter of utmost importance. A critical flow model was developed based on a vapor generation model. The model is built on the observation that choked short tube flow consist of a liquid core and a vapor annulus. Only three empirical factors were used, two to account for the assumptions made in the model development and the other to account for the area reduction due to vena contracta. The critical flow model predicted CFC and HCFC flow data with a maximum error of 13%. It failed in predicting flow data on water. / Master of Science

It is generally recognized that the recovery of particles from a flotation pulp is controlled by (i) the flotation rate constant and (ii) the residence time distribution of the particles. In the present work, theoretical and experimental analyses have been carried out to develop methods for predicting these parameters from first principles considerations. In order to predict the flotation rate constant, a bubble-particle interaction model has been developed using a dynamic force balance to determine the trajectory of a particle as it approaches a rising air bubble. The trajectory has been used to determine the probability of bubble-particle attachment, from which the flotation rate constant can be readily obtained. The model is unique in that it simultaneously considers the effects of hydrodynamic and surface forces on the interaction between bubbles and particles. Model predictions have been shown to be in good agreement with results from bubble-particle attachment experiments for narrowly-sized coal and silica samples. In the present work, the residence time distribution of particles in column flotation has been examined by conducting experimental tracer tests. These tests have been performed with two tracer materials to characterize mixing for both the liquid and the solids in a single system. The measured residence time distributions have shown that the assumption of equating liquid and solids residence time distributions is inappropriate, except for very small and low density particles. At larger sizes and higher densities, the correction formula advocated by Dobby and Finch (1985) has been shown to adequately predict the solids residence time. / Master of Science

Layout parasitics result from electromagnetic interaction between circuit metalizations used to connect devices on the hybrid circuit. Three linked programs have been written to calculate the capacitance and inductance between circuit metalizations. (1) XT Editor A user friendly hybrid circuit layout editor which enables the user to create circuit layouts and select portions of the circuit for parasitic computation. (2) XT Mesh A two and three dimensional fully automatic mesh generator. The mesh generator combines the quadrant/octant subdivision method and Watson's algorithm in a four step process. Initial triangulations are created and cell compatibility is ensured using an alternating initial mesh scheme. This method produces substantial time savings by avoiding the use of data tree structures and stringent cell size rules. (3) XT Field Solver A two and three dimensional finite element quasi-TEM solver which calculates the capacitance and inductance between circuit metalizations. / Master of Science

Many older documents are of poor quality and are deteriorating with the passage of time. Furthermore, many of these documents are currently stored in the form of paper or photographic film, and therefore storage space, accessibility, and security are serious problems. Because of these problems, many older documents are being restored and converted to digital form for archival. Image scanners which perform these tasks must be fast and must produce digital images that are of high quality. A Scan Optimizer was developed by Image Processing Technologies, Inc., to assist in the restoration and conversion processes. This device dramatically improves the throughput of image scanners by the use of high-speed complicated image processing. As originally designed, however, the IPT Scan Optimizer requires the manual adjustment of several parameters to obtain the best results for a given document. Because of this manual adjustment, human intervention was often required, and conversion speeds were drastically reduced. In order to remove the need for manual adjustments, an Automatic Parameter Setting (APS) algorithm was developed. This algorithm relies on histogram analysis over non overlapping image regions for the computation of scan parameters. This thesis describes a hardware realization of the APS algorithm. To achieve a real-time implementation that is low in cost, several compromises were necessary in the design. This two-board set is compatible with the AT bus, and is composed of one SPARC RISC chip, four Xilinx Programmable Logic Cell Arrays, ten PALs and many RAMs and supporting logic. This system has been designed, built, and successfully tested with many documents. / Master of Science