The chromatographic properties of various silicone stationary phases for capillary gas chromatography have been extensively studied, yet the properties of nonsilicone phases have not been so well investigated. The most popular nonsilicone phases are the high molecular weight polyethylene glycols (HMW PEG) which are commercially available in a wide range of molecular weights, cross-linkable and uncross-linkable (Carbowax 2OM and 4OM, the Superox series, etc.). Their most outstanding features are their unique polarity and selectivity; for this reason these phases are widely used in the analysis of aqueous solutions, essential oils, and perfumes. Unfortunately HMW-PEG's are very sensitive to slight differences in preparation and handling procedures which can cause analyses to differ with each laboratory, each column, and even each use. HMWâ PEG's also suffer from low temperature stability, a high minimum allowable operating temperature, and have lower diffusion coefficients than silicone phases. This study examines the efficiency differences of eight columns differing only in immobilization procedure and added functional groups. Comparison is made using HETP versus u and separation number (TZ) versus u curves. These curves offer important information, in particular, the effect of carrier gas, u, column operating temperature, degree of cross-linking, and cross-linking temperature on chromatographic efficiency and separation number. In addition, the contributions of the CL (resistance to mass transfer in the liquid phase) and DL (diffusion coefficient in the liquid phase) terms in the Golay equation are calculated [1]. Solids at room temperature, PEG stationary phases undergo a solid-liquid phase transition within their useful temperature range. The effect of this transition on the chromatographic properties is investigated using efficiency, separation number, capacity ratio, and retention index versus temperature curves. Four more columns, in addition to the eight mentioned above, demonstrate the influence of end-groups and the molecular weight of the stationary phase on the phase transition temperature range. / Master of Science

Wavelength division multiplexing two channels on one fiber is one approach that enables us to make use of the extremely large bandwidth of optical fibers. We start with an analysis of optical fibers, sources, detectors, filters and wavelength division ,multiplexers. Then, using the knowledge from the experimental data, we design a 20 km bidirectional WDM datalink. The design is backed up with theory and measurements. Fiber to the home is one of many applications that makes use of such a design. / Master of Science

The contingent valuation method has been used with increasing frequency to estimate the value of nonmarket goods such as wildlife. Increasing use of and demand for the method has lead to the ~) increased use of mail surveys to collect value information. Themail format, however may place limitations the method's ability to generate acceptable value estimates. This study examined the effects of various amounts of information in the hypothetical market created in mail contingent valuation surveys. The problem setting used to examine the information problem was the current controversy surrounding the pesticide carbofuran. This pesticide has some negative impacts on wildlife, most noticeably the bald eagle. Within this context, four different mail surveys were designed and mailed to Virginia residents. Each survey contained different amounts of information on the affects of carbofuranon wildlife. The impact of information on response rates, willingness to pay bids, and aggregate benefit estimates was then examined. The fllldings suggested that mail surveys with lengthy and complex contingent scenarios may tend to be less effective for commodities where respondents have had previous experiences analogous to those presented in the hypothetical market. / Master of Science

The charging systems presently being used in toll facilities impose discomfort and inconvenience to patrons, in terms of delay and stops. This report presents an analytical method to estimate delay and stops in toll plazas. These variables are then utilized to evaluate user costs and toxic gases emitted in toll plazas. A large amount of information on highway user costs was collected and synthesized to be incorporated in this economic evaluation. Recommendations on the amount of toll that should be charged to take into account user costs induced by toll plazas are given in this report. / Master of Science

Metal plates are being replaced by lighter but equally strong laminated composite plates in order to improve efficiency and increase performance of aerospace vehicles. But because of the complex construction of laminated plates they are very difficult to analyze. Conventional thin plate theories prove to be inadequate in predicting laminated composite plate behavior. Therefore, a finite element model which incorporates a first- order shear-deformation theory and nonlinear von Karman strains is described. The model is shown to accurately predict deflections in laminated composite plates due to nonuniform transient heat fluxes and transverse mechanical loads. / Master of Science

The Givens orthogonalization algorithm is an efficient alternative to the normal equations method for solving many adjustment problems in photogrammetry. The Givens method is one of a class of methods for solving linear systems known generally as orthogonalization or QR methods. It allows for sequential processing and greatly simplifies the computation of statistics on the observations and residuals. The underlying reason for these advantages is the immediate availability of the orthogonal Q matrix, which is computed as the data are processed and is intimately related to the statistics needed for blunder detection. One of these statistics, the F statistic computed from externally studentized residuals, is both easily obtained and well-suited for blunder detection. The Givens method requires nearly four times the number of computations as compared to the normal equations approach in order to reach a solution. However, depending on the size of the problem, blunder detection through the normal equations requires far more computer time than is required when starting with a Givens decomposition. The method allows a user to review intermediate results, test residuals and modify the solution without having to compute a full solution. Adjustments of a level net and a single-photo resection are used to demonstrate the method. Because of the advantage in computational time, the Givens method is superior to the normal equations approach when rigorous blunder detection is required. / Master of Science

The purpose of this study was to explore issues related to the development of pricing strategies. Important questions addressed included the importance of this topic and a description of how prices are set or why prices are set. Also, the concern of whether these issues are general across major types of pricing decisions, or specific to certain pricing decisions was investigated. Particularly, this study reviewed the descriptive survey research or case studies that have been done to determine how businesses make price decisions, and their key pricing policies and procedures. While Korea is recognized as one of the most rapidly industrializing countries, marketing and marketing research have not been fully developed, and, furthermore, there has been little research on pricing. Therefore, this study reports on a survey with 303 Korean business people about their pricing attitudes and practices in order to obtain information about Korean businesses and help them improve their pricing strategies by suggesting ideas based on price theory and previous price research. The basic results of the survey indicate that although pricing has been generally recognized as an important area in marketing by Korean business people, it has not been examined as a way to influence demand in advanced market environments. While it is revealed that Korean consumers are price sensitive and Korean business situations are competitive, Korean businesses seem to have offered similar products with a relatively rigid pricing approach based on production costs. Their pricing strategies appear not to be related to the other elements of the marketing mix. However, promotional pricing, mainly as discounts, was regarded to be important to gain a competitive edge. In terms of actual price setting in industry and firms, many Korean businesses assume the characteristics of a price taker rather than price maker. Their primary short run pricing objective was to meet existing competition. However, the major basis of their pricing policies was either competitive situation or pricing what the market will bear. This study provides a general view on the type of issues that should be considered in pricing, and evaluates the pricing practices of Korean businesses in comparison to those of more advanced countries. The study is also of value to Korean business people because it offers them information on how prices are set in various industries, and the attitudes and opinions of business people about the pricing function. / Master of Science

Karyotypes of nine species of Venezuelan annual killifishes were compared. Karyotypic differences were found between species and between some genera. A chromosomal sexual dimorphism was found in <u>Pterolebias hoignei</u> (2N = 46). Males of this species possess a single large "Y" chromosome. No chromosomal divergence was detected among conspecific populations from different localities. <u>Pterolebias hoignei</u> and <u>Pterolebias zonatus</u> were found to differ both in diploid number (46 and 42 respectively) and in metacentric chromosome number (6 and 12 respectively). All <u>Rachovia</u>species were found to have a diploid number of 44. <u>Rachovia maculipinnis</u>and <u>R. brevis</u> were found to differ from one another in metacentric chromosome number (20 and 12 respectively). <u>Rachovia hummelincki</u> and <u>R. pyropunctata</u> both possess metacentric chromosome counts of 10. No karyotypic differences were found between <u>Austrofundulus transilis</u> and <u>Austrofundulus limnaeus</u> (2N = 44, metacentrics = 12). Several populations of the latter although divergent in male color patterns, did not differ karyotypically. All species examined, except <u>Rivulus stellifer</u>, departed from the presumptive ancestral teleost diploid number of 48. The degree of chromosomal variation appears not to be as high among the New World as among the Old World annuals. This difference among lineages with similar life histories and reproductive strategies suggests that stochastic events have not played a major role in mediating chromosomal divergence in annual fishes. / Master of Science

The VPC's Planning Methodology (Strategic Performance Improvement Planning Process) has been primarily based on action research. This thesis attempts to externally validate the methodology by asking "has the methodology evolved consistently with the findings of others?" This was accomplished by comparing the methodology to other recent strategic planning/management methodologies and having planning practitioners and consultants compare the VPC's Methodology to their own methodologies. A second objective was to identify potential improvements to the methodology. In most cases, the VPC's Methodology was more comprehensive than the methodologies found in the literature. The only potential shortcoming of the methodology was the lack of an explicit component for a coordinated strategy, although the methodology includes a vision of the future and strategic objectives components. The planning practitioners and consultants offered several minor suggestions for improving the methodology, but none found any significant shortcomings in the methodology. Interestingly, none of the practitioners/consultants mentioned the lack of a strategy component; however, at least two of them felt a better link was needed between strategic and tactical objectives. This leads me to believe the VPC's Methodology has evolved consistently with the findings of others. Some of the potential improvements identified include: a relocation of planning assumptions within the process model, a revised technique for analyzing planning assumptions, the addition of a strategy component, clarification of the role of Key Performance Indicators, clarification and emphasis on under-utilized components of the methodology, and revisions to the process model. / Master of Science

The principal purpose of this investigation was to synthesize and hydrogenate well-characterized linear and star-branched block copolymers based on butadiene and isoprene. Sequential anionic addition techniques initiated by homogeneous organolithium species in hydrocarbon solvents were employed to prepare several series of butadiene-isoprene copolymers varying in block size and architecture. Linear A–B–A poly(butadiene–isoprene–butadiene) triblock copolymers were synthesized by two different living addition techniques, e.g., three-stage process using a monofunctional anionic initiator and a two-stage process using a difunctional anionic initiator. Alternatively, the synthesis of star block copolymers involved the sequential polymerization of poly(butadiene-isoprene) diblock arms which were then linked into stars via divinylbenzene. Hydrogenation of unsaturated polymers has widely attracted attention since this provides an alternate method for improving and optimizing the mechanical, thermal, oxidative and chemical resistance properties of these technological important materials. Homogeneous catalytic hydrogenation was employed to chemically modify these linear and star-branched copolymer into thermoplastic elastomers. Hydrogenation successfully converted the soft polybutadiene blocks into hard semicrystalline polyethylene segments, while the central polyisoprene blocks resulted in the formation of amorphous alternating rubbery copolymers of propylene-ethylene. The hard semicrystalline blocks form morphological domains that serve as physical crosslinking and reinforcement sites. The presence of semicrystalline segments in both the linear and starâ branched copolymers has important significance for processing. Above the endothermic melting temperature of the semicrystalline end. blocks, the now amorphous system can approach the melt behavior of a singlephase melt, that is, displaying negligible "physical" network structure in the melt. Overall, these systems display a valuable combination of good melt processability together with physical properties characteristic of A-B-A architectures. / Master of Science