In this investigation, an approach to studying hot-flow subsonic cross-stream fuel injection problems with a less complex and less costly cold-flow facility was developed and implemented. An actual ramjet combustion chamber fuel injection problem was proposed where ambient temperature fuel was injected into a heated airstream. This case was transformed through similarity parameters involving injection and freestream properties to a simulated case where a chilled injectant was injected into an ambient subsonic airstream. This task was accomplished through injection of chilled Freon-12 into the Virginia Tech 23 x 23 cm. blow-down wind tunnel at a freestream Mach number of 0.44. The freestream stagnation pressure and temperature were held at 2.5 atm. and 300°K respectively. The resulting spray plume was carefully examined and documented with photographs and droplet measurements. The results showed a clear picture of the mechanisms of jet decomposition and vaporization. Immediately after injection a vapor cloud was formed in the jet plume, which dissipated downstream leaving droplets on the order of 8 to 10 microns in diameter for the conditions examined. / Master of Science

composium = compose + symposium The use of a music/architecture analogy is employed in the design of a place for the study of composition. Four models for examination include Johann Sebastian Bach, Ludwig van Beethoven, Richard Wagner, and Arnold Schoenberg. / Master of Architecture

The purpose of this study was to assess the effects of structure in instructions and materials on preschoolers' creativity. Thirty-two children ranging in age from 41 to 59 months comprised four experimental conditions of Structured Instructions-Structured Materials, Structured Instructions-Unstructured Materials, Unstructured Instructions-Structured Materials, and Unstructured Instructions-Unstructured Materials. An effort was made to equalize the groups on intelligence and baseline creativity from scores obtained in Session 1 using the Information Task from the Wechsler Preschool and Primary Scale of Intelligence and a three-dimensional patterns task derived from Moran, Milgram, Sawyers, and Fu. In session two the children were administered the appropriate instructions and materials and two days later in session three given the same instructions with a reverse in materials. Session four was administered to determine any long term effects of session two and three and therefore consisted only of unstructured instructions and materials. Analyses which were used included a 2 (instructions) x 2 (materials) analysis of covariance performed separately for sessions two and three. All analyses were covaried on age, sex, intelligence and baseline creativity. The results did not reach statistical significance, although mean differences suggest that structure in instructions and materials limit ideational fluency. / Master of Science

Data taken during the National Bureau of Standards Durability/Reliability (NBS D/R) Program is analyzed in depth in this report. The main thrust of the analysis is to develop methods of relating material property changes to full scale collector efficiency changes after exposure to environmental and operational conditions. To this end, results of material sample and full scale collector tests are discussed separately and then related to each other. Many of the materials tested showed no measurable change in optical properties after 480 days of exposure. Therefore, the results of six representative samples which span the range of responses observed are presented in detail. Next, a mathematical model of collector thermal performance is used to show the theoretical dependence of efficiency on property values. Actual degradation measurements of three typical collectors in the NBS D/R Program are presented. These measurements, based on ASHRAE standard 93-77 tests, show degradation between 0 and 4 percent of the original value of efficiency. Also presented is an analysis of the stagnation temperature variation with exposure time. No conclusive data resulted from the stagnation temperature analysis. Finally, the mathematical model is used with results from the material tests to predict the change in efficiency. The predictions are always within ± 3 percent of the measured 480-day efficiency. Error is estimated to be a result of uncertainty in insulation conductivity values used and other unexplained sources of error. / M.S.

The National Bureau of Standards conducted outdoor durability tests on eight different types of commercially available flat plate solar collectors. The test results for five types of collectors are analyzed. The purpose of the test program was to investigate the feasibility of determining the durability of materials by measuring collector thermal efficiency at specified intervals. The important material properties include the solar absorptance and long wave emittance of the absorber surface, solar and long wave transmittance of the cover material and the thermal conductivity of the insulation. Tests were conducted by three independent testing laboratories located in Phoenix, Arizona, Cape Canaveral, Florida, and Palo Alto, California. The test sites were chosen to investigate the effects of the various environmental conditions found in the United States on collector degradation. Three test series were considered to study the effect of various operating conditions on collector degradation. The collectors were exposed to the environment for up to 240 days. The thermal performance test results did not reveal significant degradation in the performance parameters, F_r(T_α) and F_rU_L, of the collectors considered. Any degradation that may have occurred was overshadowed by experimental uncertainty. The test results did not depend on test series, geographic location or season of the year. Referring the test results to a common set of weather conditions did not reduce the scatter in the results. / Master of Science

The Knox unconformity in the central and southern Appalachians is developed on Lower to early Middle Ordovician Knox/Beekmantown carbonates. The unconformity marks the transition from Cambro-Ordovician shelf carbonate deposition on a passive margin to carbonate and clastic deposition in a foreland basin associated with a convergent margin, possibly during a time of global sea-level lowering. Erosional relief on the unconformity decreases from over 140 m in southwest Virginia to 20 m or less in northern Virginia. This corresponds with a marked decrease in stratigraphic relief in the same direction. Paleokarst features that formed on the unconformity include topographic highs that extend up to 30 m into overlying Middle Ordovician peritidal carbonates, sinkholes and caves that extend down to 65 m below the unconformity and are filled with detritus from the unconformity and breccia from host carbonates, and sub-unconformity dolomite breccia bodies that formed by collapse after dissolution of limestone interbeds. Coarse detritus on the unconformity surface formed thin to thick veneers of regolith; locally this material was reworked by fluvial and marine processes. Much fine dolomite detritus was reworked and deposited as alluvial fan and playa mud-flat sediments in lows on the unconformity surface. The unconformity influenced the regional distribution, composition and thickness of some post-unconformity peritidal carbonates. This is evidenced by lithoclastic supratidal sheets that cap cycles in these beds up to 100 m above the unconformity. Unconformity highs also may have controlled later Middle Ordovician buildup distribution in Virginia. Development of regional unconformities on shelf sequences of passive margins immediately beneath foreland basin sequences is common in other orogens, reflecting gentle warping of the shelf prior to foundering beneath synorogenic clastics. Such unconformities may localize hydrocarbons and base metal deposits (Pb-Zn), by controlling the distribution of permeable horizons adjacent to the unconformity. / Master of Science

This study investigated the relationship of both mother's and father's attitudes to their child's academic readiness for first grade. The five parental attitudes considered were: Creativity, Frustration, Control, Play, and Teaching-Learning. Academic readiness was defined in terms of pre-reading and quantitative skills. Sixty kindergarten children and their parents completed the Metropolitan Readiness Test (MRT) and the Parent as a Teacher (PAAT) Inventory, respectively. Correlation coefficients were computed between the MRT Pre-Reading Composite and Quantitative scores, and the five subset and total scores of the PAAT. Multiple regression analyses were performed to determine the best possible predictors of children's MRT scores. Results showed that parental attitudes have a significant influence on children's academic readiness. When the total sample of parents and children were considered, parents having positive attitudes concerning their children's creative development, play, and the teaching-learning process had children with correspondingly higher pre-reading skills. Control for parent sex showed that this was a significant differential factor, but other factors were found to have stronger effects. Control for both parent and child sex indicated that girls are strongly influenced by their mothers' attitudes. For mothers with college degrees, the relationship to their children’s quantitative readiness was negative. Fathers with college degrees possessed attitudes which favorably influenced their children's pre-reading readiness. No definite trend was found when controlling for family income, indicating that a broader measure of socioeconomic status may be a more useful control variable. / Master of Science

The objectives of this research were to quantitatively apply food stains to a rayon, a nylon, and an olefin pile upholstery fabric, and to determine the effects of aging times and cleaning agents on their removal. Another objective was to correlate the instrumental color change measurements with ratings obtained from a consumer panel. The specimens were soiled with mustard, vegetable oil, milk, and syrup. After aging for one day or two weeks, the specimens were treated for stain removal with a detergent-vinegar solution, perchloroethylene, isopropyl alcohol, or ammonia water while attached to a simulated chair arm. Soil removal was evaluated by measuring light reflectance and color values on a Hunter Color-Difference Meter®. A consumer panel rated the specimens according to AATCC Stain Release Replicas, and stated whether or not each specimen was acceptable for use in their homes. Statistical analyses indicated the following major conclusions: (1) the fabric and stain variables significantly affected the instrumental values of color change; (2) the variables exhibiting a significant effect on the consumer ratings were fabric, stain, and stain remover; (3) the rayon fabric tended to react the most unfavorably of the three fabrics to the treatment; (4) the milk and mustard stains tended to be the most easily removed, while the oil and the syrup stains were more difficult; and (5) a correlation existed between instrumental values and consumer ratings of color change. / Master of Science

The purpose of this study was to explore the relationship between locus of control and psychotherapy preference and the variables of rank (employment and income levels), education level, age, race, and sex on a population outside of students and clinical or institutional patients. Also, the researcher sought to identify variables in order to maximize a therapist's ability to predict individual therapeutic preferences. Eighty-three military personnel; 41 noncommissioned personnel and 42 officers, participated. The sample was chosen randomly from a population of approximately 500 enlisted personnel and 600 officers. Two measuring instruments were used: Rotter's (1966) Internal-External Locus of Control Scale and Clum's (1981) Psychotherapy Preference Questionnaire. Several hypotheses were tested. Significant results were obtained in the hypotheses addressing the difference of scores for psychotherapy preference between rank categories (employment and income levels) and racial categories. Insignificant results were obtained in the hypotheses addressing the difference in locus of control orientation between rank categories (employment and income levels) and education categories; the difference of scores for psychotherapy preference between education levels; and the relationship between scores on the locus of control and psychotherapy preference scales. / Master of Science

This thesis is an investigation of the concept of paracompactness. It presents the history of paracompactness, analyzes this concept from several diverse points of view and tries to establish the relationship between these different views. The starting point is the work of Tukey [40]. The important problem of the metrization of topological spaces is presented as an application of the concept of paracompactness. / Master of Science