The question of whether the mafic and ultramafic rocks of the central Virginia Blue Ridge are part of a Late Proterozoic to Ordovician ophiolite-bearing sequence or part of an intrusive-extrusive sequence related to the Late Proterozoic Iapetan rifting has major implications for Appalachian tectonic models. Current models consider most of the Blue Ridge cover sequence to be ophiolitic mélange that was obducted onto Laurentia, thus implying a suture or terrane boundary is associated with the rocks. Detailed field mapping and petrography of three typical mafic-ultramafic complexes in the central Virginia Blue Ridge (the Catfish, Flat Creek, and Schuyler complexes) indicate that these bodies do not show characteristics that resemble ophiolites. The three complexes are broadly conformable with stratigraphic layering, and the Lynchburg Group host strata form a continuous and conformable stratigraphic sequence unbroken by faults and without evidence of mélange. Contacts between the mafic-ultramafic bodies and the host rocks are sharp and show no strong evidence for faulting or other disturbances. Internal contact relations and the presence of autoliths indicate that these bodies were derived from multiple injection of a fractionating basaltic magma. The characteristics of the Catfish, Flat Creek, and Schuyler complexes confirm that the mafic-ultramafic association is an intrusive sequence rocks intimately related to the Late Proterozoic Iapetan rifting. The rocks are not part of a Late Proterozoic to Ordovician ophiolite sequence or mélange. Therefore, there are no sutures or terrane boundaries in the central Virginia Blue Ridge. / Master of Science

The analytical models for the design of automatic guided vehicle systems (AGVs) available in the literature are limited to the computations of the fleet size and the design of the guide path layout. Another major design factor which affects the performance of an AGV system is the locations and the dimensions of the control zones. The control zones facilitate congestion free flow of AGVs along the guide path. A proper design of the control zones is extremely important for the functioning of the AGV system. When the effects of the control zones are included in an analytical model, its solution procedure becomes complicated and difficult to be solved. This is due to the various interactions between the work stations and AGVs caused by the control systems. In this thesis, Petri net theory is introduced as an alternative method for the modeling of AGV systems. It is a graph theoretic tool which can easily capture synchronization and resource sharing situations which are common in AGV systems. Further, well developed mathematical procedures are available to analyze them. A systematic Petri net modeling procedure for AGV systems using sub nets is provided in this thesis. The Petri net model is used to compute the fleet size and the control zone dimensions of the AGV system. / Master of Science

Master of Architecture

The purpose of this work was to develop an infrastructure for a Management Information System concurrent with the development of a System Dynamics model for VDOT’s Highway Management System and the Interface between the two. Specifics include identifying the detailed source for each parameter or developing recommendations for future data collections. The MIS is to be in both a hard (paper) and a soft (paperless) format. The soft copy will be based on the hypertext format and be Windows compatible. Parameters to be researched were identified from the model simulation code and causal diagrams. These were then grouped into common themes and/or sources, assigned a target date for research, and discussed with key personnel at VDOT with regards to their validity within the model and from a data collection stand-point. Those parameters identified as not obtainable, due to gaps within VDOT’s database system were then estimated using engineering judgment in conjunction with key personnel at VDOT. Obtainable data was gathered from VDOT’s databases and annual reports as well as other sources. Key VDOT personnel then reviewed all gathered data for its soundness. Researched parameters were then written-up with any assumptions, definitions, and sources outlined along with the current value based on the 1995 data. Although VDOT’s databases were effective in obtaining data for the majority of the parameters, gaps exist within the system, which required significant input from key personnel for recommended data collection. VDOT’s personnel proved to be the most valuable asset in data compilation. Of particular note is the need for statistical analysis of the data in the form of control charts to determine the relative validity of each value within the parameter’s distribution. / Master of Science

Distance relays are commonly utilized for the protection of transmission lines. A distance relay calculates the apparent impedance between the relay location and the fault location, and uses this value to determine the approximate location of the fault. Traditional distance relays, however, are plagued with problems caused by faults through a resistance. The fault-path resistance causes the apparent impedance determined by the distance relay to appear larger than the actual impedance between the relay location and the transmission line fault location. This error in the apparent impedance may deceive the relay and cause it to misoperate. Errors due to fault-path resistance are a fundamental problem of distance relaying. The solution to the problems caused by fault-path resistance is presented in the form of the advanced distance relay. The advanced distance relay is a computer-based relay which employs a fault locator algorithm that is immune to the effects of resistance in the faultpath. The major substance of this document is dedicated to explaining the algorithms utilized to create the advanced distance relay. A major advantage of the advanced distance relay is that it is a single-ended relay. In other words, it requires voltage and current information from only one end of the transmission line that it protects. Another advantage is that knowledge of the system equivalent source impedance is not required. While knowledge of the distribution factor phase angle, parallel line zero-sequence current, and parallel line zero-sequence impedance are not required, in the event that they are available, the relay can provide even more refined, accurate results. The advanced distance relay prototype was written in the "C" programming language. It utilizes a sampling frequency of 1440 Hz, and includes an algorithm that eliminates DC offset in the current waveform. The relay also employs a 1/2 cycle DFT phasor calculation algorithm, which provides the data required by the per-unit fault locator equation. The implication of this information is that the relay is capable of making a “trip / block" decision in just over 1/2 of a cycle. As mentioned, the most powerful feature of the advanced distance relay is its immunity to the effects of fault-path resistance. It is this immunity that allows the relay to overcome the aforementioned fundamental problem of distance relaying. Consequently, the advanced distance relay is a powerful addition to the tools of protective relaying. / Master of Science

The inclined stepper is a novel piece of exercise equipment that is designed to offer precise control over a wide range of loading levels and exercise speeds by simulating an inclined stepping motion (21). The purpose of this study was to evaluate the relationship and test-retest reliability of the stepper ergometer. Twenty-eight healthy volunteers (age: 23.5 ± 3.6 yrs) completed a graded treadmill (TM) and two graded, step (SI, SII) ergometry tests to assess maximal oxygen consumption (V̇O₂max). The order of these tests was randomized. Expired gases were analyzed using the Medical Graphics CPX/D metabolic cart. V̇O₂max between SI (V̇O₂ = 2.57 L/min) and SII (V̇O₂ = 2.65 L/min) revealed an correlation of r=.91. The S trial with the highest V̇O₂max value for each subject was used to compare with the TM. A one-way ANOVA was performed on the cardiopulmonary and perceptual data. Mean values and SD for the best stepper were: HRmax = 183 ± 10.0 bpm, V̇O₂max = 2.6 ± 0.6 L/min, RER = 1.27 ± 0.07, RPE = 17.1 ± 1.6. Mean values and SD for the treadmill were: HRmax = 193 ± 8.8 bpm, V̇O₂ max = 3.2 ± 0.8 L/min, RER = 1.15 ± 0.04, RPE = 17.8 ± 1.4. Construct validity showed that the percentage of tests that achieved maximal test criteria for heart rate was 96%; for RPE was 46% and for RER was 100%. These findings indicate that the inclined stepper elicits a significantly lower cardiovascular and metabolic response at maximal exercise as compared to the treadmill. In addition, the data suggests that this modality has many desirable features for assessment in the laboratory and use in the fitness arena. / Master of Science

With completion of the project, it is important to critically examine the result in order to derive new thought or insight gained from the design process. I feel, at least for the time being, that the narrative of the architectural experience is sufficient, and of itself a valid closure for all lines of reasoning. However, we are left with the thesis that claims that the Virginia Polytechnic Institute and State University Center for Culinary Arts has provided a new meaning; that it is filled with light. Perhaps a better, yet less abstract theory would claim that light provides us with the knowledge that sustains us in our productive and creative endeavors. Our creative visions are dependent upon it as well as our basic need for life itself. This is a sad moment in the course of the thesis project for several reasons. First, many years have been spent with its involvement and facilitation. Second, the desire remains to continue with its path of exploration, to improve upon it - to make it better. Finally, the friends made along that path; I must let them go, at least for a time. And, at this juncture, I have found this to be inherently problematic with the nature of a thesis project. Conversely, this is a happy moment. The project remains as a direct result of the experience. Though it has a "shelf-life" (the model and the drawings), the thesis remains that there is a new meaning: that which is filled with light. So, in transcending the experience, I take this gift of light which has been facilitated so patiently and constantly to that which is new. And, perhaps, those that have been involved with the process of its making will also find a new meaning as a result of the exchange. "Hence the legend that in a classical work, even if only a tiny fragment survives, one can always reconstruct the whole." / Master of Architecture

The first of two studies surveyed fish communities and habitats in first-order spring streams in Virginia. Springs exhibited low species (3.3) and trophic guild (2.5) richness, and fish densities averaged 0.47 individuals/m². Two species, blacknose dace (Rhinichthys atratulus) and sculpins (Cottus sp.) dominated most sites. Spring size and location factors more effectively predicted fish community structure than did instream habitat or riparian condition, indicating that composition of Virginia spring fish communities was limited by access to colonization sources. Location, size, and instream habitat of springs were related to presence of common fish species and trophic guilds. The second study evaluated livestock impacts on biotic communities of ten Virginia spring streams. Riparian and instream habitat was significantly altered and nitrate levels were elevated in heavily grazed watersheds. Within the fish community, piscivores and young-of-year benthic invertivores were adversely affected by habitat loss associated with increasing cattle densities. Benthic macroinvertebrate communities showed significant trends in composition across the gradient of grazing intensities. Fish communities were correlated with riparian condition, whereas benthic invertebrate communities were correlated with benthic habitat degradation and nitrate enrichment. Benthic macroinvertebrate community structure was a reliable indicator of cattle-related spring stream degradation, but fish metrics were related to riparian condition. / Master of Science

Any historian of eighteenth-century England, especially London, examines the emerging "middle ranks", but they often neglect to address how gender shaped the growing middle-class identity. The importance of gender in the formation of a middle-class identity is often not apparent because the arenas in which gender was regularly debated, like pleasure gardens, are not studied. Examining public spaces like pleasure gardens demonstrates the limitations imposed on women's history by "separate spheres” historiography and contributes to our understanding of women's work because it shows that women worked outside a domestic economy. In pleasure gardens, middling and working women encountered each other while they challenged gender expectations and with their behavior, they laid the cultural foundations of a later feminist movement. The ability to pursue leisure was an important facet of middle-class life and in studying places of public democratic leisure like pleasure gardens, we begin to see shared ideas of gender emerging in popular culture. / Master of Arts

This thesis examines the cultural and political applications of aerial photography. The thesis emphasizes the historical development of aerial photography technologies and the incorporation of these systems into national policy. The Majority of the discussion details the U-2 reconnaissance program. There is an account of the evolution of the system under Eisenhower, explanation of its selection over other intelligence programs, development of photographic equipment, and the formation of a professional staff to analyze the U-2 imagery. This thesis analyses the use of U-2 imagery under Kennedy to precipitate and then monitor the resolution of the Cuban Missile Crisis. The analysis of the technologies and historical record utilizes a methodology defined as hermeneutical. Hermeneutics is the study of communication, or the exchange of knowledge accomplished through a text. The treatment of aerial photography as a text provides insight into the multiplicity of roles it played in national policy. Normative logic has knowledge emanating from photography, deciphered by science, and passed on to policymakers. There has been no concerted effort to integrate the politics and the science of aerial photography. This thesis challenges that discursive separation of science and politics. By examining the entire process, from flight planning to analysis to briefing of policymakers and finally, to the formation of policy, a different model of information exchange emerges. The science and politics of airphoto interpretation share a co-dependency where knowledge transfer is not a one-way street, but an interactive, co-dependent exchange. / Master of Science