The chief function of the Virginia Polytechnic Institute Central Heating and Power Plant is to provide steam for heating the various building: on the campus. The plant also furnishes the campus and the community of Blacksburg with a portion of their power requirements, the campus with hot water, and the college laundry with soft water The basic function of the plant, however, is the generation cf steam to be used for heating most of the buildings located on the oampus.The electric energy is generated as a by-product of the basic heating function of the plant. / Master of Science

None / Master of Science

Although the minimum qualifications for election to the American Farmer Degree have remained essentially the same during the last ten years, the actual achievements the candidates for the American Farmer Degree have increased beyond these minimums. / Master of Science

It was found in this investigation that the testing of supersonic airfoils at subsonic speeds to obtain pressure distributions will result in considerable error if the models are tested at very low Reynolds Numbers. The thickness of the boundary layer is critical at low Reynolds Numbers and causes a decrease in the overpressure region. This, coupled with the fact that the overpressure region increases more with Mach Number than predicted by the theory, could lead to erroneous calculations of the drag. / Master of Science

The literature on marriage reveals only one study which deals specifically with expectancies in marriage of college students, This study does not attempt to measure change in expectancies from on period to another or to differentiate between wishes and expectancies, Several investigators in the area of marital relationships express the need for further research on the predictive value of factors existing in the lives of individuals before marriage as they may or may not influence marital success. One factor which these investigators feel may be highly predictive of success or failure in marriage is the individual's expectancies from the marital relationship / Master of Science

1. Reciprocal crosses were made between a DDT-resistant and a nonresistant strain of the German cockroach. 2. The techniques employed in rearing the roaches and obtaining toxicological data on the different strains, as well as the genetical and statistical procedures, are described. 3. The toxicological data are presented in the form of regression lines with appropriate statistical analyses. 4. A table showing the relative resistance to DDT of the various strains involved in this study is included. 5. Several conclusions are drawn relative to the inheritance of resistance to DDF in the German cockroach. / Master of Science

The model investigated, exhibits and defines in mathematical expressions all the laws of common mechanical behavior of an inelastic solid. As a result, it excels the more common models discussed in the introduction not only in completeness of behavior, but also in possibilities of application In a practical sense, it is of interest to note the similarity between the stress-strain curves of the model and those of some aluminum alloys, Duralumin, magnesium and copperâ ¢ The creep and strain recovery curve of Fig. (20) is in close agreement with that of real metals discussed by Nadai (l5). This seems to indicate that the model will be useful in giving mathematical equations for the behavior of these metals under different test conditions. / Master of Science

Tests were conducted on three-member southern pine joints to determine (1) the relationship of the lateral load-carrying capacity of nails in single and double shear, and (2) to develop a basis for structural design data for laterally loaded nails in double shear applicable whenever deformation is a governing factor, such as in joints of trussed rafters. The test loads at or near proportional limit show that low-carbon-steel plain-shank and helically threaded Screwtite nails loaded in double shear carry twice the single-shear loads; while hardened high-carbon-steel plain-shank and Screwtite nails loaded in double shear carry considerably less than twice the single-shear loads. If these relationships between single-shear and double-shear loads are to be valid, the nail must be optimum diameter tor the joint. Structural design data as based on test loads at or near proportional limit for laterally loaded low-carbon-steel plain-shank nails in single and double shear are applicable to low-carbon-steel Screwtite nails and to same-length, smaller-diameter, hardened high-carbon-steel plain-shank and Screwtite nails. This finding, however, is not valid if consideration is to be given to the load-carrying capacity beyond proportional limit and at ultimate, to the influence or exposure on nail-holding power, and to certain advantage resulting from the use of threaded-shank as well as hardened nails. Design data as advanced in the National Design Specification for low-carbon-steel plain-shank nails in single shear are verified within their scope. Additional information is presented on the performance or plain-shank nails, Screwtite nails, and Stronghold Screwnails under given conditions, on the effects or pre-boring and clinching, and on the efficiency or toothed-ring Burrlock fasteners as reinforcement for nailed lumber joints. / M.S.

The purpose of this thesis is to investigate the properties and wave velocities for an axially symmetric medium. The investigation consists of four parts. In the first part, the physical properties of the medium are defined. Then the stress-strain relations for the case under consideration are obtained from the general case. This is done by imposing the condition of symmetry on the strain energy function. Next the measurable constants are round in terms or the natural constants. This is done by applying simple extensions and shears to the material. After the measurable constants are determined in terms or the natural constants, then the relationship is inverted and the natural constants are found in terms or the measurable constants. Some elastic constants are then determined for an arbitrary direction, as it is not likely that the stresses will always be imposed along an axis of symmetry. Following this major part, the equations of motion for a vibrating medium are determined in terms or the natural constants by substituting the stress-strain relations. This is very straightforward, but must be done. The final step is made by finding the velocities of propagation of the waves by using the equations of motion. This is done by assuming a solution and substituting into the equations of motion. From these equations, a cubic equation defining the three principal velocities arises. The solution of this cubic equation is the culmination of this investigation. / M.S.

The speed of a chemical reaction is important in determining the efficiency of many industrial chemical reactions. In organic reactions particularly, when there is the possibility of several reactions going on simultaneously, that reaction which is fastest is the one that predominates and often affects the economics of the process. The object of this investigation was to determine the effect of ultrasonic irradiation on the specific reaction rate of the hydrolysis of an aqueous solution of ethyl acetate in the presence of hydrochloric acid as the catalyst. The commercially obtained ultrasonic generator was limited to four frequencies - namely, 400, 700, 1000, and 1500 kilocycles. Two thousand volts plate voltage could be applied to the quartz crystal plates provided the plate current did not exceed 360 milliamperes. A special pyrex glass reactor was designed and constructed in order that isothermal conditions could be maintained within the boundary of the reactor. The period of time the reaction mixture was subjected to ultrasonic irradiation was arbitrarily set at 10 minutes for a given power and frequency at 19 ± 0.1°C and 30 ± 0.1°C respectively. The tests were then repeated using a 20 minute period of irradiation. Individual mixtures were respectively irradiated at 0, 500, 1000, and 1500 volts plate voltage. The composition and volume of the mixture irradiated was 100 ml of 1.9904 N hydrochloric acid, 90 ml of distilled water free from carbon dioxide, and 10 ml of ethyl acetate making a total volume of 200 ml. The chemical reaction assumed for the investigation was CH₃COOC₂H₅ + H₂O + H⁺ ⇋ CH₃COOH + C₂H₅OH + H⁺ The course of the reaction was followed in such a way that the concentrations of the reacting substances were not disturbed. Samples of the mixture were drawn off at intervals and titrated with sodium hydroxide using phenolphthalein as the indicator. Calculations were based on the difference of the titration at any time t in minutes and the titration at the end of 24 hours. When the reaction was completed, this difference was a measure of the concentration of ethyl acetate remaining unchanged or unhydrolyzed at time t. Each molecule of ethyl acetate that hydrolyzed produced one molecule of acetic acid, and the increase in acidity was a direct measure of the amount of ethyl acetate that had reacted. The amount of hydrochloric acid remained unchanged throughout the experiment. The concentrations of ethyl acetate calculated from the differences between the titration values and the final titration were arranged in tabular form. A graph was drawn on semilogarithmic paper by plotting the concentration of ethyl acetate, c, against time, t, in minutes and the best straight line through the points. Using the equation, - log c_A (k / 2,303) t+ constant, the specific reaction rate, k, was calculated by multiplying the slope of the line by 2.303. The activation energy, E, was calculated from the values of k at 19 ± 0.1°C and 30 ± 0.1°C using the equation, E = [2.303 log₁₀ k₂/k x R x T₁ x T₂] / [T₂ - T₁] where k₁ = specific reaction rate at 19 ± 0.1°C k₂ = specific reaction rate at 30 ± 0.1°C R = Constant T₁ = Absolute temperature for 19 ± 0.1°C T₂ = Absolute temperature for 30 ± 0.1°C The results of this investigation showed that the specific reaction rates were increased by ultrasonic irradiation of 400, 700, 1000, 1500 kc in the order of five percent for 20 minutes irradiation over the rates for 10 minutes irradiation. / Ph. D.