A pulseback technique for cleaning and renewing a panel bed contractor suitable for chemical or physical treatment of liquid and granular material was investigated. Free surfaces of quartz sand for the entry of water were provided by vertical support louvers. A pulseback technique was used to rid the liquid entry surface of the sand. The pulseback consisted of a reverse transient flow of liquid across the panel bed of sand. The time of duration of the pulseback was a maximum of 100 milliseconds. The amount of sand removed from the panel bed was found to be related to the pressure drop across the panel bed and the duration time of the pulseback. A description of the pulseback equipment, the pulseback data, and the correlation of the pulseback date are included. / Master of Science

The purpose of this study was to determine the background characteristics of the riparian landowners of Virginia, to identify any problems with river recreationists, and to explore their attitudes toward recreational boating on their river and toward scenic river designations. During the summer of 1977 a mailback questionnaire was sent to 1129 landowners living along randomly selected segments of 29 scenic rivers of Virginia. Seventy percent of the 995 eligible respondents returned the questionnaire, providing the data for this study. It was found that most riparian landowners are middle-aged, well-educated members of the middle class who have lived in Virginia most of their lives. Slightly over half of all the landowners live on their property year-round and have lived there for many years. Littering, trespassing, and invasion of privacy are the problems most frequently encountered by landowners. Generally landowners have a positive attitude toward recreational boating and scenic river designations. Three-fifths approve of recreational boating on their own river and think boaters should be allowed to use any river in the state. Two-thirds of the landowners advocate protection of the scenic values of their river, and three-fourths support scenic river efforts. It is suggested that this positive attitude be encouraged by promoting local participation in the planning and management of scenic rivers in Virginia. / Master of Science

Architecture may be defined as the manipulation of forms and materials for the creation of physical environments conducive to its users. However, many spaces appear to be designed arbitrarily, forcing the user to conform to what is there. This lack of congruency seems to be especially prevalent in the design of work environments. Often work environments are designed upon assumed employee needs and desires that have not been first substantiated or tested. By measuring employee attitudes toward features in their physical environment, an understanding of employee needs and desires could be gained. But because very few attempts are made to obtain employee responses towards their physical environment, the methods for obtaining this type of information are not well established in the design fields. This study has evaluated the questionnaire as a potential instrument through which to measure employee attitudes about their physical environment. The case chosen for this study was the convention hotel. As background for the development of the questionnaire, the history of the hotel industry was explored and interviews and on site observations by the researcher were conducted. The interviews were extremely helpful in determining which factors to address in the questionnaire. Various statistical programs were executed upon the questionnaire data to establish relationships between features considered important in the work environment and the various employee groups in the hotel for use as guidelines in the design of work environments. The questionnaire was proven to be a reliable instrument through which to measure employee attitudes toward their physical environment and by further supplementing its results with other data collection methods, a more thorough understanding of those features in the physical work environment considered important to the employee could be gained, enabling the architect to design work environments that are more conducive to employee needs and desires. / Master of Architecture

The major purpose of this study was to determine whether differences in clothing interest existed between selected groups of women of 25 to 65 years, and to identify the dimensions of clothing interest important to them. The relationship between clothing interest and certain demographic characteristics was also investigated. A modified version of the Creekmore Importance of Clothing questionnaire was used to measure clothing interest. The questionnaire and a demographic data form were distributed by mail to women in the Washington, D.C. area resulting in 312 usable replies. The subjects were predominantly married, middle cJass, employed women with small fair.ilies. Most of them had college educations and higher than average incomes. Multivariate analysis procedures were used to determine the differences in clothing interest between the four age groups. Wilk's Lambda was used to detect statistical significance. Simultaneous confidence intervals were then computed to determine which groups were different and on which variables they differed. Significant differences were found on two factors of clothing interest--concern with personal appearance and enhancement of security. Multiple correlation coefficients were computed to determine the possibility of and relationship between each of the five factors of clothing interest and the selected demographic variables. No significant relationships were found. The results indicated that more mature women had less need for clothing to build self-confidence and more concern with personal appearance than the younger women in the study. / Master of Science

A simple model for the interaction of a tangentially oriented wall jet with the boundary layer is presented. The boundary-layer equations for steady, two-dimensional, homogeneous, incompressible flow are solved using an implicit finite difference technique. Calculations are performed for laminar and turbulent boundary layer flows with and without tangential jet injection. Results from the finite difference calculation for the laminar, non-injected cases are compared with the Falkner-Skan similarity solutions. Results from the finite difference calculation for the turbulent, noninj ected cases are compared with a two-parameter integral analysis. The boundary-layer calculation is applied to wall-jet injection near the leading edge of a representative combustion turbine blade. The blade geometry is developed by distributing a standard airfoil section over a single-parabolic camber line. / Master of Science

The energy crisis begins with human manners of using natural energy and his attitude toward the natural environment. The most effective actions of energy conservation in building design do not lie in engineering oriented solutions but are in the effort in designing with nature. Based on this belief, this thesis intends to investigate the potential of energy conservation in building and its relationship with architectural design. The purpose of this thesis is to develop a systematic method for designers to deal with energy problems. This method incorporates natural forces with human factors and aesthetic values in a systematic design approach of (1) exploring design situation, (2) analyzing the problem structure, (3) identifying design criteria, (4) investigating sub-solutions, (5) developing alternative solutions, and (6) evaluating and decision-making. Although it is an articulated approach, enough flexibility has been built in it so that the conventional designers may apply it in their design works. Nevertheless, it is believed that the greater benefit of this method can be achieved through a holistic attention to the proposed process. / Master of Architecture

Froth flotation was used to separate the pyrite sulfur and ash from pulverized coal samples of Illinois No. 6, Pittsburgh, and Middle Kittanning seams. In order to depress the coal pyrite in the flotation process, the coal samples were conditioned in "bacterial liquor." Iron oxidizing bacteria Thiobacillus ferrooxidans was used to cause the superficial oxidation of the coal pyrite. A number of chemical substances known as pyrite depressants were used to suppress pyrite in the flotation process. The results of the tests with the bacteria and the pyrite depressants were then compared. The effects of flotation reagents, variations of flotation pulp pH, and mean temperature of the flotation pulp were studied. Also the effectiveness of the freshly made "bacterial liquor," recycled "bacterial liquor," and old "bacterial liquor" was tested. The retention time studies of coal in "bacterial liquor" showed that for a five hour retention time, the maximum sulfur removal from Illinois No. 6 coal seam was accomplished. The effect of increasing the ratio of coal to "bacterial liquor" in the conditioning tank was studied. It was concluded that the sulfur removal increases as the pulp density increased. Illinois No. 6 coal seam samples were examined optically by binocular, reflected light, and scanning electron microscopes. The degree of dissemination of pyrite in the coal matrix was observed. Washability studies of Illinois No. 6, Pittsburgh, and Middle Kittanning coal seam samples were performed. The washability curves of these coals are presented. / Master of Science

The best characterized of the autonomous parvoviruses are those of rodent origin. The purpose of this study was to examine the physicochemical characteristics of the genome of an autonomous parvovirus of non-rodent origin, bovine parvovirus (BPV). BPV was isolated from infected cells by centrifugation through a sucrose-CsCl step-gradient. The virion DNA was released from the capsids by alkali treatment. Upon chromatography on hydroxyapatite, two peaks of radioactivity were consistently observed. Peak I eluted at a sodium phosphate concentration of 0.17 M, intermediate between single- and double-stranded DNA markers. Peak II eluted in the same position as double-stranded DNA. The DNA eluting in peak I represented the viral genome. About 7% of the genome length was found to exist as a duplex. The BPV DNA was found to have sedimentation coefficients of 16.5 Sand 27 S in alkaline and neutral sucrose, respectively. These S values corresponded to a molecular weight of approximately 1.7 x 10⁶ daltons. The BPV DNA was rich in thymine (31.3%) and had a GC content of 45.1%. The buoyant density of the single-stranded BPV genome was determined to be 1.721 g/cm³. The DNA eluting in peak II was shown by hybridization to be of BPV origin. Furthermore, the peak II DNA was shown to be of the same size as the single-stranded BPV genome, by sedimentation in alkaline sucrose. Electron microscopy revealed that the peak II DNA was linear and double-stranded. It is concluded that BPV packages the plus strand into separate virions in significant amounts, resulting in the reannealing of complimentary plus and minus strands upon release from the virions during isolation of the DNA / M.S.

Two lines of chickens, derived by two-way selection for either a high (HPC) or low (LPC) plasma corticosterone response to social stress, were inoculated with Marek's disease virus (MDV). Lymphocyte transformation (LT) microassays were performed to assess the CMI response of leucocytes from HPC and LPC MDV-infected chickens. Blastogenesis was quantitated by ³H-thymidine uptake. Leucocytes from chickens specifically sensitized with either heat-killed tuberculin or 1,5-di-fluoro-2,4-dinitrobenzene were subsequently stimulated in vitro with either purified protein derivative (PPD) or dinitrophenyl-bovine serum albumin (DNP-BSA) conjugate. Phytohemagglutinin (PHA-P) was used to assess non-specific lymphocyte transformation. MDV-infected HPC and LPC chicken leucocytes were also compared for their ability to lyse ⁵¹Cr-labeled fowl erythrocytes upon stimulation with PHA-P. Leucocytes from non-infected LPC control chickens underwent blastogenesis to a greater extent than did non-infected HPC control chickens. Although all tumor-bearing chickens demonstrated a markedly suppressed LT response, LPC chickens demonstrated a greater LT response than did HPC chickens. Relative to steroid level chickens infected with MDV, but without tumors, demonstrated a suppressed LT response; however, this response was greater than that of chickens with tumors, but less than that of normal controls. Under conditions of sustained high social stress, HPC chickens demonstrated a decreased cell-mediated cytotoxicity (CMC) in comparison with LPC chickens. In both steroid lines, CMC decreased with the onset and severity of tumors. The impaired CMI seen in the HPC line corresponded with an increased tumor incidence and a greater mortality in this line than in the LPC line. Metyrapone, a chemical which blocks adrenal corticosterone synthesis, transiently enhanced CMC and initiated tumor regression in birds debilitated with MD tumors. Early treatment with 500 ppm metyrapone mixed in feed was most effective. / M.S.

Members of the genus, Treponema, require long-chain fatty acids for growth in vitro. Serum, added to culture medium, provides a source of long-chain fatty acids. These fatty acids, however, are esterified to triglycerides, phospholipids, and cholesterol. In this study, the major pathways of complex lipid catabolism in five species of Treponema were investigated. Lipase, the enzyme which hydrolyzes triglycerides, was demonstrated using four lipid substrates in five species. Chromatographic data demonstrated that, during growth, treponemes completely utilized lysophosphatidylcholine, present in serum-supplemented culture medium, while phosphatidylcholine and phosphatidylinositol were not utilized. Whole cultures and cell free extracts were examined for the presence of specific enzymes of phospholipid catabolism. Phospholipase B and glycerophosphorylcholine diesterase activities were demonstrated in five species of Treponema. Acid phosphatase activity was demonstrated in two species. Utilization of L-α-glycerophosphate and glycerol, products of phospholipid catabolism, was examined. Glycerol was utilized from culture medium by one species, while α-glycerophosphate was utilized by four species. Phospholipases A, C, and D, α-glycero-phosphate dehydrogenase, and alkaline phosphatase activities were not found in five species of Treponema. Based on the specific enzymes demonstrated in this study, two pathways of phospholipid catabolism are proposed. / M.S.