The goal of the research was to develop a non-intrusive optical thermal sensor that could withstand the high temperature, reacting flow environment of operational turbines. A fiber optic thermal sensing design was chosen because of two main attributes, one was the remote/non-intrusive sensing and the other was the distributed sensing potential (the ability to measure temperature as a function along the fiber). In the prototype sensor design a Dy: YAG layer was coated onto the core of a fused silica optical fiber. The Dy: YAG is a ceramic material which fluoresces in the visible when excited with ultra-violet radiation. The visible emission has a direct correlation with temperature up to the melting point of the ceramic (~2100 K). The basic mechanism used to excite the Dy: YAG is the evanescent wave coupling of the guided pump radiation out of the core and into the coating. This mechanism was utilized to produce bound rays within the fiber from the Dy: YAG emission signal which in turn are guided to a detector. The pump radiation was launched into the fiber core to remove optical path difficulties in turbines allowing a spatially distributed sensor capable of measuring the temperature as a function of distance along a single fiber. The ceramic material (dysprosium doped yttrium aluminum garnet) was synthesized utilizing a precipitation reaction and x-ray diffraction patterns confirmed the existence of a YAG crystalline structure. An excimer pulsed laser deposition coating technique offered the best thin-film uniformity and adhesion properties (as in the Eu: Y₂O₃ thin film), but the existing facilities could not coat the Dy: YAG thin film due to temperature limitations of the substrate heater. Therefore, the fibers were coated with a thick film using a slurry bonding technique. The main objective of the experiments conducted as part of this study was to evaluate the effectiveness of the evanescent pump/emission wave coupling and external pumping of the coated fibers. The external pumping of the coated fibers showed that the emission signal can be separated from the background noise with a rather fast, 20 picosecond per point sampling rate, oscilloscope. This was not the case for the majority of the measurements (the noise was greater than the signal) taken with an oscilloscope which could not resolve the pulse (5-6 data points resolution vs. ~5,000). Therefore, further investigation is needed to determine the feasibility of the Dy: YAG coated fiber optic thermal sensor. / Master of Science

Evidence indicates that the mammary gland may contribute to its own development by the production of insulin-like growth factor-I (IGF-I). To generate a model for investigation of the effects of enhanced IGF-I synthesis in the mammary gland, six transgenic founder mice were produced by microinjection of a cDNA sequence encoding ovine IGF-I (oIGF-I) under the control of the glucocorticoid-responsive mouse mammary tumor virus (MMTV) promoter. Transgenic lines were established from each MMTV-IGF-I transgenic founder, and four virgin and four lactating mice from each transgenic line were analyzed for transgene expression following administration of dexamethasone or vehicle. Virgin mice from three transgenic lines (15, 26, and 29) expressed oIGF-I mRNA and recombinant IGF-I in the mammary gland, although stimulation with exogenous dexamethasone was required for expression. Lactating mice from four transgenic lines (2, 15, 26, and 29) expressed oIGF-I mRNA in mammary tissue, but only three of those lines (15, 26, and 29) produced detectable recombinant IGF-I in milk and mammary tissue. Recombinant IGF-I was not detected in plasma from any of the transgenic lines. The biological activity of recombinant IGF-I secreted into the milk of lactating transgenic mice was demonstrated in vitro by stimulation of ([³H]thymidine incorporation into DNA of immortalized bovine mammary epithelial cells. The MMTV-IGF-I transgenic mice will provide a model for evaluating the effects of increased mammary synthesis of IGF-I on mammary gland development and function. / Master of Science

The interaction of stainless steel threaded fasteners with stainless steel locking inserts was investigated with special emphasis on high-vacuum environment applications. Nondestructive and destructive test methods were used in conjunction with information gathered from investigation with a scanning electron microscope coupled with an Energy Dispersive X-ray Spectrometer. Since high-vacuum environment applications require very limited use (if any) of lubrication for threaded fastening systems, galling between the threaded fastener and the locking insert was determined to be the major concern. Galling occurs at the highly loaded thread interface of the components and is attributed to the adhesive and sliding wear conditions that exist between the two. Separation between the threads of the threaded fastener and the threads of the locking insert is more important in reducing galling potential then the use of a stronger stainless steel fastening material. For high-vacuum environments, the use of a 0.0001 inch thick flash silver plating on the locking insert provided the best results of the galling reduction methods tested. / Master of Science

The purpose of this research is to investigate finite element analysis results of two- and three- dimensional models of stepped structures and shouldered shafts with varying fillets and varying size ratios. Combined loading conditions were placed on the models to observe how the loading conditions effect the stress concentration factors. The results from the finite element analyses were compared to Peterson’s photoelastically determined stress concentration factors. The results were within five percent of Peterson’s results. For the two- dimensional case, axial and bending loads were applied separately and then superpositioned to evaluate the effect combined loading has on stepped structures. The finite element analysis results from the combined loading agrees to within four percent of the results obtained by calculating the maximum stress at the fillet using Peterson’s stress concentration factors applied to both axial and bending stresses. For the three- dimensional case, bending and torsion loads were applied separately and then superpositioned to evaluate the effect combined loading would have on shouldered shafts. It was determined for pure bending and pure torsion the finite element analyses are comparable to within five percent of Peterson’s reported stress concentration factors. But under combined loading conditions, the finite element analysis reports a more accurate solution than using Peterson’s stress concentration factors, because Peterson doesn't take into account the hoop stress acting on the shaft. / Master of Science

In December 1962 the Kennedy administration canceled the Skybolt missile program. Skybolt was an air launched ballistic missile being developed by the United States for use by both the US Air Force and the British Royal Air Force. Its abrupt cancellation caused a short "crisis" in Anglo-American relations. The Tory government of Harold Macmillan accused the Kennedy administration of canceling Skybolt to force an end to their independent nuclear deterrent. The American government countered that the decision was based solely on technical and financial grounds. This thesis expands on the questions addressed my previous authors of why Skybolt was canceled and why its cancellation became a "crisis." The present author maintains that the cancellation resulted primarily because of changing military policy instituted by the Kennedy administration and because of heightened disarmament efforts. It is also argued that the mechanics of decision making within the Kennedy executive contributed to the crisis atmosphere. / Master of Arts

In the early design stages of car bodies, many alternative designs need to be evaluated quickly. This requires checking whether these designs satisfy given performance targets and manufacturing and packaging constraints. Therefore, it would be very useful to have a tool that rapidly analyzes the performance of a design, checks if this design is manufacturable, and meets packaging and styling requirements. This thesis presents a method for developing a tool, called translator, that translates physical design parameters defining a joint into performance (stiffness of the joint) and operational parameters (mass of the joint) using a parametric model and structural analysis software. A parametric model is a solid or surface model defined by a set of parameters that specify the dimensions and topology of the design. When the user changes the values of the parameters, the model changes automatically. Physical design parameters, such as the main dimensions of the joint (height and width of the members, plate thickness, etc.) and dimensions of adjacent components and also parameters that specify the type of construction of the joint are used to define the parametric model. These parameters are selected in a way that they make sense and can be controlled by designers. Once these parameters are specified, all dimensions of the joint fall into place due to packaging, manufacturing, and styling constraints. The translator first derives a set of master parameters, which completely define the geometry of the joint from the physical design parameters using the packaging and manufacturing constraints. Examples of master parameters include the coordinates of the edges of the cross section of a member. Pro-Engineer, parametric modeling software, is used to construct a solid model of the joint using the transparent master parameters. A finite element model is then created using Pro-Engineer mesh generator, and this model is used to estimate the stiffness and mass of the joint using finite element analysis. The method also calculates parameters associated with the constraints and checks if the values of these parameters are within limits dictated by the constraints. The translator is demonstrated on two joints of an actual car. / Master of Science

This research effort is motivated by the need to quickly obtain origin-destination (O-D) trip information for an urban area, without expending the excessive time and effort usually accompanying survey-based methods. The proposed approach aims to exploit the information contained even in a "partial set" of available link volumes to estimate an O-D trip table. Recently, a new approach to synthesize a trip table from observed link flows on the network was developed at Virginia Tech. This approach employs a linear programming formulation and is based on a non-proportional assignment, user-equilibrium principle. The model is designed to determine a traffic equilibrium network flow solution that reproduces the link volume data, if such a solution exists. If such alternate solutions exist, then it is designed to find that which most closely resembles a target trip table. A modified column generation technique is employed to solve the problem. The methodology also accommodates a specified prior or target trip table, and drives the solution toward a tendency to match this table using user controlled parameters. The limitation of this approach is that it needs the specification of a complete set of link flows for its accurate operation. Such a requirement limits the applicability of this model to real networks, since link volumes are not always available on all the links of a network. This research work enhances the above linear programming methodology, adding the capability to estimate OD trip tables even when only a "partial set" of link traffic counts are available. The proposed approach formulates a sequence of linear programs to approximate a fundamentally nonlinear optimization problem that is employed to estimate origin-destination flows, given incomplete network flow information. The research suggests techniques for terminating a given linear program in the sequence, as well as criteria for terminating the sequences of such LPs, and also develops a procedure for continually updating the cost vector from one linear program to the next. Modifications in the column generation technique, necessary to solve the revised model formulation, are also developed. The enhanced model is evaluated and compared with the maximum entropy approach, which is a popular approach for OD table estimation. These models are evaluated through tests on an artificial network and a real network. The tests aim to evaluate these models using various sets of link volumes and prior table information. The results indicate that the linear programming approach performs better than the maximum entropy approach for most cases. Conclusions and recommendations for future research are also presented. / Master of Science

Crab cooker wastewater contains high concentrations of chemical oxygen demand (COD), total suspended solids (TSS), and total Kjeldahl nitrogen (TKN). Biological treatment of the wastewater releases high concentrations of ammonia. In this study, UASB treatment of crab cooker wastewater was evaluated, in terms of COD and TSS reduction, and compared with previous anaerobic treatment efforts. Additionally, UASB and UBF treatment of crab cooker wastewater was demonstrated with pilot-scale treatment units. The potential for air stripping to remove ammonia from biologically treated wastewater was evaluated. When treating unamended crab cooker wastewater, UASB performance appeared similar to UPF and UBF reactor performances reported by Diz and Boardman (1994). When treating unamended wastewater at a 0.25 day⁻¹ F/M ratio, a UASB reactor’s effluent soluble COD fluctuated and increased to above 6,000 mg/L. Batch toxicity assays indicated that unionized ammonia limited anaerobic treatment performance. Unionized ammonia concentrations of 41 and 120 mg/L (as nitrogen) caused 50 and 80 percent inhibition, respectively, of acetate utilizing methanogens. Acidification of the feed wastewater greatly enhanced UASB treatment performance by reducing reactor pH and wastewater feed suspended solids concentrations. When fed acidified wastewater at a 0.3 day⁻¹ F/M ratio, a UASB reactor’s effluent soluble COD was 1,220 mg/L. The wastewater feed TSS was reduced from 910 mg/L, prior to acidification, to 249 mg/L in the reactor’s effluent. An air stripping tower’s ammonia removal efficiency increased from 50 to 72 percent as the air flowrate increased from 9 to 21 m³/min. The average liquid loading rate and liquid temperature were 25 L/m²/min and 14° C, respectively. / Master of Science

The study explored job satisfaction among 12 childcare teachers and 6 directors uSing semi-structured interviews. The interviews generated a range of facets that comprise job Satisfaction. Relationships with the children was a primary source of satisfaction for most of these childcare professionals. Participants expressed that interacting with the children and observing their learning and development were important contributors to their feelings about their job. Relationships with parents also emerged as an important dimension of satisfaction or dissatisfaction with the work. Teachers mentioned communication, team work and support from one another as important aspects of peer and supervisory relationships. The pay that teacher's received was not directly related to job satisfaction, as most reported choosing the field despite low pay. Some teachers said, however, they would change their profession, if they could not pay all their bills. Those who plan on remaining in the field often had a second source of income. As depicted above, pay played a greater role in life satisfaction than in job satisfaction. In regard to center characteristics, some teachers voiced frustration over the limited availability of supplies as well as stress regarding having too many children in the room. Personal needs such as receiving adequate breaks and flexibility in getting time off from work also were discussed as important contributors to their job satisfaction, particularly because teachers were primary caregivers at home. This research demonstrates the multifaceted nature of job satisfaction and the value of using interviews and qualitative analysis to identify salient aspects. / Master of Science

Communication is one of the most important aspects in any project. This is especially true in the case of projects in the Architecture-Engineering-Construction industry. The traditional forms of communication such as drawings and specifications are not adequate in achieving the required levels of understanding among project personnel. The concept underlying the project, i.e. the collection of arguments and decisions and the thought underlying them are not communicated. This may lead to various project personnel having differing views about the requirements of the project. This research focuses on an attempt to communicate the thought process underlying the project to the various project personnel so that they have an unambiguous and clear understanding of the essentials of the project and to test the success of this attempt using a field example. The thought process or concept underlying a project is defined as the design rationale for the project. There have been many approaches to the communication of the concept that is the basis of a project. After a literature survey of the various approaches, the design rationale approach, which attempt to explicitly communicate the rationale was chosen. Considering the various definitions and models of design rationale, a model based on the Lee and Lai representation was chosen as the basis for this work. Making certain adaptations to the Lee and Lai representation based on the requirements of the industry, a representation structure consisting of rationale networks was developed. Based on the rationale representation, DRARS, an object oriented rationale representation tool was developed. The rationale was represented in DRARS using object networks. DRARS was then tested on an actual project involving the renovation of a school building. Based on the collection and representation of the rationale, DRARS was evaluated for its abilities to easily author and represent design rationale. DRARS performed well in achieving both the objectives of ease of authoring and the richness of representation. DRARS, however stores rationale that is not computer processable and presents the rationale for human interpretation. DRARS also uses multimedia to support the richness of the representation. / Master of Science