<p>Sense of Place is a Project GeoSim educational software module focusing on U.S. states and counties. A comprehensive statistical database is combined with a set of simple visualization techniques to allow geography students to gain an understanding of the characteristics of states and counties. Students can examine data for anyone of the statistical variables in the database. In addition, students can create me tries consisting of target values for several variables, and rate counties or states by how closely their data match the targets. Symbolic mapping is used to illustrate spatial characteristics of a state or county, such as its size, shape, and location, as well as regional patterns among different states and counties. Graphing is used to illustrate basic concepts of data distributions and to depict the distributions of specific variables. A spreadsheet is used to view the multivariate data sets created by user metrics. These visualization techniques and the graphical user interface tools required to control them are incorporated into interchangeable "views". This approach allows additional views to be added to Sense of Place in the future. / Master of Science

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Cost control, resource availability, or difficulty in performing complete randomizations may dictate the necessity to run response surface experiments in a bi-randomization error control format of which the split plot design is a special case. A bi-randomization scheme allows for certain factor levels to be applied at random to large experimental units with the remaining factor levels randomly applied to nested smaller units. For example, in the dual response surface approach to robust parameter design, process mean and variance models are formulated to aid in designing products to be "robust" to uncontrollable system influences called noise variables. In model development, noise variables are assumed to be controllable in the laboratory, but due to their random nature they may be costly and/or difficult to control. This suggests the need for a bi-randomization scheme in which the noise variables constitute the levels applied to the larger experimental units. For the bi-randomization situation, two types of bi-randomization designs are explored along with their respective analyses and various error variance estimation procedures. The efficiency of common response surface designs are also examined in the presence of this alternative error structure to determine the necessity of design modifications to better accommodate the error structure. General recommendations for efficient designs and practical analysis methods are outlined. / Ph. D.

This research investigated the effect of mouse support height, mouse type, and hand length on the wrist posture of computer mouse operators. Mouse support height was defined as the distance from the floor to the horizontal surface on which the mouse is supported and divided into three levels: 95%, 100%, and 105% of the seated elbow height. The levels of mouse type were the Logitech MouseMan, Kensington Thinking Mouse, Apple Desktop Bus Mouse, and the Apple Desktop Bus Mouse II. Hand size was defined as the distance from the stylion landmark on the right hand to the tip of the middle finger. The twenty-four subjects were divided into three groups of eight according to hand size (small, medium, and large). The average distance in degrees from neutral was calculated for the first set of dependent measures. Results showed that an increase in the mouse support height caused a decrease in the amount of wrist extension and an increase in the amount of ulnar deviation for both pointing and dragging tasks. There was also a significant interaction between mouse support height and hand size for wrist extension during pointing tasks. Mouse type and hand size were not found to be significant as main effects in either pointing or dragging tasks. It was probable that the differences in the physical characteristics of either the user's hands or of the mice were not great enough to affect the posture of the user. For the second set of dependent measures, wrist posture was divided into intervals that ret1ect the severity of posture. Mouse support height was found to significantly affect the amount of time spent in different posture intervals. The remaining independent variables did not significantly effect these dependent measures. / Master of Science

The management of the high volume and different types of information that characterize its projects, has traditionally posed a constant challenge to the architecture, engineering and construction industry. The distribution and communication of such information to project participants, who are often geographically dispersed, is an important necessity and forms a significant part of this challenge. Hypermedia computing on the Internet has emerged as an important and efficient means for the distribution and communication of information. This thesis proposes hypermedia computing on the Internet as a solution to address the problem of information distribution in the architecture, engineering and construction industry. The problem of information management is examined, and relevant features of hypermedia and the Internet discussed. The viability of the technology to address the specific problem of information communication and distribution is demonstrated by building a hypermedia based information system as proof of concept. The thesis concludes with a discussion of future developments in this technology and the scope for further work in hypermedia based information distribution systems. / Master of Science

Harriet Martineau (1802-1876) published How to Observe Morals and Manners in 1838. The book was perhaps the first sociological methodology text. Emile Durkheim (1855-1917) published The Rules of Sociological Method (1895) 57 years later. Durkheim's book has traditionally been labeled as the first sociological methodology text, while Martineau's book has been virtually forgotten by modern day sociologists. The author identifies significant similarities between the two texts and investigates the possibility that the work of Martineau influenced Durkheim. This work explores the life an important figure in nineteenth century European culture and argues that Martineau's name should be reinserted into the history of sociology. The ideas contained in, and the construction of, How to Observe Morals and Manners are discussed. / Master of Science

Five liquid dairy manures and five dry broiler litters were tested in the laboratory to determine the effects of four preservation techniques on the forms and concentrations of nitrogen. 300 ml samples of fresh manure from five Virginia dairy and five poultry farms were analyzed for total Kjeldahl, ammonium, and nitrate/nitrite nitrogen within 24 hours of farm sampling, and at the end of seven days. Samples of the fresh manure were analyzed immediately as a control. The four preservation techniques were storage of the samples: at ambient temperature (26°C), by freezing (-22°C), by refrigeration (4°C), and by acidification with sulfuric acid (H₂SO₄) to pH < 2 plus refrigeration (4°C). Concentrations of nitrogen fractions were tabulated on a dry-weight basis and statistically analyzed using a randomized block design, with subsampling of each treatment × farm combination. Organic and inorganic nitrogen concentrations from the preserved manures were compared to the corresponding fresh concentrations of nitrogen in each manure control. Ambient storage, freezing, and refrigeration did not significantly affect (α=.05) the 7-day nitrogen concentrations of the ten manures. Acidification reduced most N concentrations due to the aggressive physical action of the acid, which accelerated both mineralization of organic N and volatilization of ammonia. Ambient storage was recommended as the most practical preservative technique because, of the three successful preservation methods, ambient storage provided the simplest procedure for 7-day preservation of nitrogen in liquid dairy manures and dry broiler litters. / Master of Science

Lack of age control for deposits >40,000 yr makes it impossible to differentiate between the complex effects of climate and geomorphic age on weathering intensity, soil profile development, mineral stability, and elemental flux within the pedoenvironment. Upland soils formed in similar granitic parent materials along a climatic gradient in the nonglaciated Southern Piedmont Province were analyzed in order to investigate whether soil response to variations in the weathering environment follows predictable, systematic patterns related to climate, and to quantify the nature and magnitude of these relationships, particularly with regard to processes of secondary mineral neoformation and transformation. With few exceptions, all measures of weathering intensity increase dramatically from north to south on the Piedmont. The effective depth of pedogenesis in the Georgia and Alabama soils studied is nearly twice that of soils in Virginia and North Carolina, closely corresponding to calculated effective leaching indices developed for each site. Kaolinite and gibbsite are poor indicators of soil age, weathering intensity, or paleoenvironment because of complex mechanisms of formation. Kaolinite genesis is shown to result from i) desilication of 2: 1 phyllosilicates in surficial horizons ii) hydrolysis of K-feldspars, iii) resilication of gibbsite deep in the saprolite, and iv) recrystallization of halloysite in the soil/saprolite transition zone. Gibbsite forms from both desilication of kaolinite and by reprecipitation after N a-feldspar dissolution at depth. Halloysite is common to all soils as the product of both feldspar and biotite weathering, thus illustrating the overriding influence of microenvironment in secondary minerals formation. Clay content is linearly related to Fed in Virginia, North Carolina, and Georgia soils, with regression slopes decreasing from north to south. Clay content levels off at higher Fed values for Alabama soils, indicating that i) steady-state conditions are approached as pedogenic clay formation reaches some intrinsic, self-limiting threshold value, and ii) the limiting factor in clay production over time is leaching intensity, and not the concentration of Fe-bearing primary minerals, in contrast to the soils studied soils in Virginia, North Carolina, and Georgia, appear to have reached a steady-state with regard to clay production. These data suggest that soils farther south on the Piedmont have experienced conditions of greater geomorphic stability and longer weathering. Until we can obtain numetical dates for Piedmont soils, however, one can only speculate as to whether the observed differences in pedogenesis and weathering intensity are due to age effects, climatic effects - or both. / Ph. D.

Comprehensive year-round limnological investigations of Mountain Lake, Virginia were conducted from November 1992 through October 1994. Monthly physical, chemical, and biological measurements suggest that this ecosystem has shifted toward a more eutrophic condition. A trend in whole lake mean annual orthophosphate-phosphorus and inorganic nitrogen increases have occurred over the past decade, although primary productivity, cell densities, and chlorophyll a values indicate no consistent trends. Hypolimnetic oxygen deficits, however, have continued to increase over time, and in October 1994 the first measure of anoxic deep water was observed. Concurrently with the chemical changes, shifts in macrophytes and phytoplankton have occurred. Most notably were reductions in Nitella megacarpa and Dinobryon spp., an increase in Ceratophyllum sp., and a summer dominance of Sphaerocystis schroeteri and Aphanocapsa_ elachista. These two species represent algal classes, Chlorophyceae and Cyanophyceae, which have also increased in relative abundance and seasonal persistence in Mountain Lake. Nutrient addition studies conducted in 1994 indicated limiting concentrations of both phosphorus and inorganic nitrogen during most periods of thermal statification. Significant increases in primary productivity occurred within 48 hrs with the addition of K₂HPO₄ and/or NH₄NO₃ in the pico-, nano-, and microplankton size classes. The smaller size fractions (picoand nanoplankton) responded more strongly to the N enrichment, whereas the microplankton responded more with the P enrichment. In all cases, ammonium-N was the preferred inorganic nitrogen source during these Studies, as suggested from earlier studies of methylamine uptake in this lake. Studies of the importance of various phytoplankton size classes (pico-, nano-, micro-, and macro-) during thermal stratification indicated that the microphytoplankton were the most important size class in cell number, cell diversity, and contributed ~95% of the total primary productivity. The picophytoplankton were second in importance constituting ~5% of total primary productivity, whereas the relatively small numbers of nano- and macrophytoplankton contributed little primary productivity. This finding contrasts to many other oligotrophic ecosystems where the pico- and nanophytoplankton have demonstrated significantly greater importance. Increasing nutrient concentration, increasing hypolimnetic oxygen deficit, and shifting phytoplankton community structure suggest that Mountain Lake is entering the early stages of eutrophication. Continuation of increasing nutrient loads in this natural lake will potentially further shift this ecosystem toward eutrophic conditions. / Ph. D.

Study 1 was conducted to determine if partial restriction of testicular thermoregulation affects spermatogenesis when compared to full restriction by mild scrotal insulation for 48 h. Study 2 and Study 3 were conducted to investigate the efficiencies of selected semen separation techniques on the removal of abnormal spermatozoa. in Study 1, semen from control and partial scrotal insulation (Pl) bulls did not differ between the pre-insult and post-insult period for any variable measured. Full scrotal insulation (Fl) bulls differed for several variables measured, but at different intervals and for different durations post-insulation. Spermatozoal motility and acrosomal integrity were reduced during Period 3 only of semen collection with no effect on sperm output. Full insulation caused abnormalities to be ejaculated from d 10 to 33 post-insulation. Specific morphologically abnormal cells occurred in a chronological order. The order of occurrence was: tailless heads, diadem defect, nuclear vacuole defect, pyriform shaped heads, protoplasmic droplets, severely misshapened heads, acrosomal abnormalities, and the dag defect. In Study 2, a pooled sample of frozen-thawed semen from FI bulls in Study 1 was separated using swim-up separation, glass wool filtration, Percoll® density gradients (45/90% two-layer and 50/70/90% three-layer), and Sephadex® filtration. Glass wool filtration was basically without effect and will be excluded from further discussion. All other separation techniques improved motility from the initial sample at the expense of spermatozoal harvest. The subtle head abnormalities were unaffected by separation for all techniques and spermatozoa with nuclear vacuoles on normal shaped heads were enriched; however, head abnormalities were removed with increasing frequency as the severity of the head distortion increased. In Study 3, frozen-thawed ejaculates with a high concentration of spermatozoa with nuclear vacuoles (>20%) were separated using 45/90% Percoll® and 45/100% Percoll® density techniques. The greater the number of nuclear vacuoles per sperm head, the more efficient the removal of such sperm. The separation of spermatozoa with subtie head distortion as well as spermatozoa with nuclear vacuoles on normal shaped heads by density separation, would allow further assessment of the importance of these abnormal sperm to decreased fertility and increased embryonic mortality. / Ph. D.