In the preparation of practically all chemicals there is the necessity of drying, either of the final product or of one or more of the materials used in its preparation. If the material is in solution, or in a suspension, it can be easily handled by drying upon the surface of an internally heated drum. Continuous sheets such as paper and cloth are also dried this way. If the material is easily damaged by high temperatures it may be dried under a partial vacuum. Considering their adaptability, ease of operation, and relative efficiency of operation, it is not surprising that the drum driers are extensively used... / Master of Science

The purpose of the investigation was to determine the interfering effect on the polarographic method of nitrate analysis of certain chemicals commonly employed in the water purification process. Chemicals tested consisted of coagulants, a disinfectant, and an algaecide. A. “synthetic” water of known chemical consistency was used for diluting purposes. The investigation consisted of two phases; (1) establishing a standard curve with 95 per cent confidence limits of nitrate concentration versus current reading, and ( 2) determining the amount of nitrate recovery in samples containing known nitrate concentrations and certain chemical additives. A further investigation was made of the effect of chemicals revealing a pronounced interference during the initial test. The results obtained indicated that ferric chloride, ferric sulfate, chlorine, and copper sulfate did not interfere with the nitrate analysis. Alum and ferrous sulfate caused a significant interference. The loss in nitrate recovery due to the presence of alum in solution was found to be directly proportional to the alum concentration. Nitrate recovery was reduced from 0 to 10% by alum dosages of 0 to 10 gpg respectively. Although ferrous sulfate caused considerable reduction in nitrate recovery, this is readily explained since ferrous sulfate may be used for the destruction of nitrate in polarographic procedure. When a number of samples were analyzed, the average time required was about 20 minutes per sample. Thus, the time required to perform a nitrate analysis by the polarographic method compares favorably with other methods of analysis. / Master of Science

Methods for the preparation of active carbons from many kinds of carbonaceous material have been described in the literature. Many processes of activation for many different raw materials are used to obtain active carbons for specific purposes. In general, all of these processes involve a low temperature carbonization of the raw material followed by a slow, controlled oxidation of the carbonized product. A high temperature of carbonization (above 600°C.) results in a product which is not active and cannot be activated. Any selection of a process or raw material must be based on a knowledge of the ultimate use of the product as well as on economic considerations. Certain physical properties are desirable for certain uses in addition to the general property of being adsorbent to foreign molecules. A gas adsorbent carbon should be dense with a rather small pore size; while liquid adsorbent carbons should be less dense, not triable, easily filterable from solutions, and have a larger pore size than the gas adsorbent type of carbon. In view of the low yield obtained in any process of activation, a cheap and plentiful raw material would be advantageous. Coal is such a raw material and active carbons have been prepared and used to a limited extent from coals. It has been reported that an initial chlorination of a geologically young coal before its carbonization results in a high yield of a good active carbon. The existence of large deposits of such a coal in the Piedmont section of Virginia and North Carolina which has not been exploited to any great extent, because it is not suitable as a fuel, seems to warrant a further investigation of this chlorination process with an idea of its possible economic use in the preparation of an active carbon. The purpose of this investigation in the preparation of a liquid adsorbent active carbon from a high volatile Midlothian coal by a process of chlorination followed by carbonization and steam activation. / M.S.

Liquid and slurry jets were injected through a circular orifice transverse to a M = 3.0 airflow. Mass samples of both jets were taken across the plume 30 injector diameters downstream. Pitot and static pressure surveys were taken across the liquid jet. These data allowed the calculation of distributions across the liquid jet plume of Mach number, air mass flow, liquid-to-air ratio, and momentum flux. A correlation for the liquid concentration in the downstream plane is also presented. In the plume, there is a core region of subsonic airflow carrying two-thirds of the mass collected in the plume. In the core, the liquid mass flow is nearly constant from side-to-side at a given height, and the average velocity of the liquid is only 30 to 60% of the local air velocity. A supersonic mixing region covering two-thirds of the area of the plume surrounds the core region. Comparison with the results from this direct sampling data indicate that correlations developed from photographic techniques are inadequate in determining the jet penetration and width of liquid and slurry jets. The slurry jet showed substantial phase separation. A 30% mass-loaded slurry of 1-5 µm silicon dioxide particles mixed with water was injected, and the local loading varied from a low of 13% at the bottom of the plume to 100% outside the liquid plume. The local loading increased as the jet boundary was approached from any direction. / Master of Science

The purpose of this study was to use the Eating Disorder Inventory (EDI), Negative Addiction Scale (NAS) and other measured characteristics to determine differences between consistent runners and sedentary controls. 38 male and 23 female local non-team related runners of more than 9 miles per week were studied. They completed the EDI and NAS. 31 male and 30 female nonexercisers completed the EDI. They were drawn from college classes and participated in less than one hour per week of physical activity. Height, weight and body fat were determined for both groups. As compared with anorectics, none of the EDI subscale averages for runners or controls were higher than the 38th percentile. Body dissatisfaction was less for runners than controls. Females scored higher on drive for thinness and body dissatisfaction. Female runners scored significantly higher on drive for thinness than all other groups. The mean NAS score was 78 for the females and 74 for the males. Significant body dissatisfaction subscale differences found between runners and controls were probably due to the runners' lower body fat and weight. In looking at the male/female differences, females typically have a stronger concern about weight and are less satisfied with their bodies. It is believed that in the group of runners studied, severe eating disorders did not exist. / Master of Science

The role of social play in juvenile behavioral development was examined in the punare (<u>Thrichomys apereoides</u>). Three proposed functions of social play were evaluated: 1. play serves to develop agonistic skills, 2. play has a role in the onset of weaning and 3. play establishes dominance relationships among participants. Eight litters consisting of three juveniles and both parents were observed from birth until eight weeks of age, and the content, sequence and duration of parental and play behaviors were recorded. Adult agonism was characterized in paired encounters between. unfamiliar adults. Encounters between unfamiliar juvenile dyads were conducted and compared to litter mate play. Sex specific differences in social play were concordant with observed differences in adult agonistic interactions. Play bouts between male juveniles were more frequent, of greater duration and incorporated more dominance reinforcement behaviors than bouts between females. Mothers tended to avoid playing with offspring, while paternal play was frequent. Self-handicapping was observed during father-daughter play. Dominance relationships were evident during play, with strong, stable hierarchies established among male juveniles. Adult males dominated all offspring and juvenile males dominated female littermates. Unfamiliar juvenile play bouts were shorter in duration and more frequently resulted in avoidance than bouts among litter mates. These results suggest that punare social play functions to develop agonistic skills while concurrently establishing dominance relationships. The early establishment of dominance relationships may serve as a non-injurous means of precipitating male-biased post-weaning dispersal. / Master of Science

In order to improve the design and to control satisfactorily the operation of the modern sewage disposal and industrial waste treatment plants, a great deal of work remains to be done by competent sanitary engineers, biologists, and chemists. It is the general belief that the stabilization of organic wastes is a biological phenomena. This indicates that a concentrated study of the organisms that are responsible for such stabilization should be undertaken and the part that each organism contributes should be evaluated The lack of specific knowledge has resulted in "rule of thumb" methods of design and control. A considerable amount of work on the biology of sewage disposal has been done by the New Jersey Experiment Station (4)(5)(8); by C.T. Butterfield and Elsie Wattie of the U.S. Public Health Services (10) (13) and by others, but a concentrated effort is still needed. James B. Lackey (1), has done an excellent job in summing up the work accomplished to date in the field of sanitary biology in his article “Sewage Treatment Biology”. In this article, Dr. Lackey lists four things that must be known before a clear picture can be presented on the subject of sewage and waste treatment. These points are as follows: (1) More precise information on the species of each group of organisms working in treatment plants. (2) The relative abundance of each so that no important (numerically or volumetrically) organism is neglected. (3) The range-not optimum- of environmental conditions under which the organism works. (4) The work accomplished by the organisms - whether a small segment of the stabilizing process, or a large one. Gerald A. Rohlick (2), in discussing Lackey’s article, places special emphasis on additional experimental work that should be done on the activities of protozoa and higher forms of life. The editors of Savage Works Journal (3) have summed up the problem in the following statement, “When we can answer completely the what, how, who, when and why of the organisms that populate our digestors, aerators and trickling filters, we shall simultaneously solve the problems of treatment plant design and operation that are of present concern”. In an effort to contribute something to the fund of knowledge of sanitary biology, the author undertook an investigation based on the for needs suggested by Lackey. The investigation is divided into three major parts: (l) A preliminary investigation; (2) the construction of a pure culture testing apparatus; and (3) the testing of a pure culture of organisms. The complete investigation is confined to studies of the organisms found in the aerobic phase of treatment, the precise source being the trickling filter at the Virginia Polytechnic Institute sewage disposal plant. This confinement of purpose was to allow the investigator to conduct a concentrated study of a single phase of treatment. The preliminary investigation consisted of taking frequent samples from the trickling filter and examining them under the microscope. The predominate organisms were noted and the development of pure cultures of each was attempted. The construction of a pure culture filter consisted of an attempt to duplicate in the laboratory as nearly as conditions would allow, the actual conditions that exist in the trickling filter at the plant, while at the same time observing pure culture requirements and techniques. The testing of the organisms consisted of measuring the amount of purification exerted by the organism on a synthetic sewage as it passed through the filter. The results of this investigation should answer two questions: First, can a pure culture apparatus be constructed and operated with such success that it can be used as a standard device for determining in the laboratory the degree of purification exhibited by organisms in pure culture, and Second, is it possible for a pure culture of organism to carry on the purification process. The answer to the second question will, of course, depend on a positive answer to the first question. / Master of Science

Estimates of feed produced by pasture were obtained from pasture investigations at the Tidewater Field Station from 1949 through 1953, Dry lot groups of pigs similar to those fed on pasture and fed similar rations were used to estimate total concentrates necessary for maintenance and gain of pigs on pasture. Feed production of each pasture was estimated from the difference between concentrates consumed by the pigs on that pasture and total concentrates for similar performance in dry lot. Estimates for 1949 and 1950 were based on the regression of feed consumption on average daily gain of pigs fed in dry lot. Weight of the animals was not considered in computing these estimates, In 1952 and 1953 the regression of feed consumption on weight was the basis for estimates when pigs were fed at the high level of nutrition, end feed required per pound of gain above maintenance for similar weight pigs was the basis for estimates, when pigs were fed at the low level of nutrition. Direct comparisons were made between pigs fed in dry lot and on pasture at the high level of nutrition, since feed consumption and weight were similar, This was not the case with pigs fed in dry lot and on pasture at the low level of nutrition. Feed consumption was the same but average daily gain differed significantly. Since the low level of nutrition provided slight gain for pigs in dry lot, it was necessary that this gain be subtracted from the total gain made by pigs on pasture. The net gain was assumed to be the direct result of the pasture, The feed required per pound of gain above maintenance was calculated and multiplied by the net gain (gain made from pasture), the product being an estimate of the feed replacement value of the pasture lot. Estimations were calculated on a per acre basis. A summary by years of the feed replaced by the pasture is shown in Table 15. This summary indicated that a more consistent estimate was obtained when weight of the animals was included in estimating expected feed consumption, Exceptions to this occurred in 1952 and 1953 when pigs were self-fed on ladino clover. In 1952, the estimated feed replacement value of the pasture, when pigs were provided supplement, was 584 pounds, while in 1953 the estimate was 93 pounds. When supplement was not included in the ration, the feed replaced by the pasture was 26 and 903 pounds for 1952 and 1953, respectively. / Master of Science

Master of Science

1. This is a study of 60 white teachers of vocational agriculture in Virginia to determine the desirable content of a farm power and machinery course for vocational agriculture in the high schools of Virginia. The purposes of the study were: a. To determine the nature and content of farm power and machinery units being taught by teachers of vocational agriculture in the high schools of Virginia. b. To determine the teaching units in farm power and machinery that should be included in the high school vocational agriculture course. Based on the teaching experience of the teachers included in this study, it is concluded that the practices being used and recommended by a majority of these teachers should be considered as acceptable guides for all teachers to follow in organizing and conducting their instructional program in farm power and machinery. The recommended teaching units include a study of: determining the place of power and machinery on the farm, preventing accidents on the farm, tractors, transportation equipment, tillage implements, seeding equipment, lime, manure, fertilizer distributors, harvesting equipment, crop processing equipment, clean, grading equipment, spraying, dusting equipment, pumps, rams, miscellaneous farm equipment, and storing equipment. / M.S.