A technique for digitally generating random time histories having arbitrarily shaped power spectra is presented. Four random time histories having significantly different statistical and power spectral properties have been generated and analyzed to determine their mean and amplitude distributions. It was found that the distribution of means could be approximated by a normal distribution and that the distribution of amplitudes could be approximated by the sum of a Rayleigh distribution and a normal distribution. An attempt was made to relate the coefficients of the equations used to represent the distributions of means and amplitudes to the power spectral properties of the generated time histories. It was found that two of the coefficients could be related to the power spectral properties of the time histories. The remaining two coefficients were empirically determined since no apparent relationship was found between these coefficients and the power spectral properties of the generated random time histories. In addition a discussion of the applicability of results for estimating fatigue life under randomly varying loads or stresses is presented. / Master of Science

The theory of organization that this thesis proposes possesses a characteristic plasticity that should enable it to span the gap that has traditionally existed between the two broad types of current organizational theories. Generally, one type of theory proposes to describe how organizations should function and the other type proposes to describe how organizations actually do function. The first type of theory often seems to result in proposals derived from formal, mechanistic concepts that are necessary, but largely superficial and not profoundly significant in an operational sense. The second type of theory essentially seems to suggest that an “informal organization'' actually functions to achieve the organizational objectives and such an organization is a function of existing personalities and, as a result, no universally applicable principles appear to exist upon which design considerations can be based. Such conclusions are usually drawn from some form of case studies that inherently produce knowledge that proves incomplete and ephemeral as events move on and organizations evolve. Therefore, this theory seeks to reconcile and integrate the basic principles of these two types of theories by conceptualizing the basic principles of engineering design and statistical stability as they apply to organizational processes. / Master of Science

A soluble enzyme system, isolated from livers of biotin-deficient rats, catalyzes the ATP-dependent synthesis of propionyl holocarboxylase from d-biotin and propionyl apocarboxylase. This system has been resolved by alumina C_∂ gel fractionation into two essential components; (a) gel supernatant which contains propionyl apocarboxylase and (b) gel eluate which contains an enzyme which catalyzes the covalent bonding of d-biotin to propionyl apocarboxylase. The propionyl holocarboxylase synthesis catalyzed by these enzyme systems is irreversible and d·biotin specific. The gel supernatant has been further purified by hydroxyapatite chromatography and (NH₄)₂SO₄ fractionation and the gel eluate by (NH₄)₂SO₄ precipitation and cellulose-phosphate chromatography. An enzyme similar to the gel eluate enzyme has been isolated from cell-free extracts of Propionibacterium shermanii. Although cell-free extracts of P. shermanii do not contain propionyl apo- or holocarboxylase, they do catalyze ATP-dependent propionyl holocarboxylase formation from d·biotin and rat liver propionyl apocarboxylase. Biotin-2'-C¹⁴-labelled propionyl holocarboxylaae, synthesized with these enzyme systems, does not transfer C¹⁴O₂ to propionyl-CoA indicating that the ureido carbon of enzyme-bound biotin is not the"active carbon" of biotin. / Master of Science

A single crystal neutron spectrometer using a copper crystal has been designed and constructed for the purpose of studying the low energy (<1 ev) neutron spectrum from the V.P.I. reactor. The basic theory necessary for the design, the details of the spectrometer, calibration data and method of operation are presented in this thesis. A relation between angle of diffraction and neutron energy is obtained from the known lattice spacing of the copper crystal. A measure of the total cross section of cadmium from 0.01 to 1.0 ev has been obtained from transmission data for a thin cadmium sheet. The position of the low energy resonance peak confirms the computed calibration. The resolution of the instrument and the intensity of the diffracted beam as a function of energy were studied in order to ascertain the usable range of the spectrometer. / Master of Science

The rising awareness of existing problems created by rapid population expansion has resulted in systematic investigations of the characteristics of population growth. These investigations have produced methods for projection of future populations. Attempts have been made to project world population, but the situation is too heterogeneous to provide useful results. Population problems, although of world-wide importance, are problems of particular peoples and particular areas. Some of the earliest methods of projection used in the United States were based on the Malthusian Law and geometric progression.Pritchett and Pearl, in the late 1800's and early 1900's, devised parabolic methods of projection. These early projections were good for short term projection but generally unrealistic for long range use. In 1920 Pearl and Reed devised an empirical curve, later known as the logistic curve of' population growth.. This method received considerable attention. The logistic was supported by many later demographers and the resulting projections satisfied all but a few critics. Whelpton's “analytical method,” and other similar methods, have been widely accepted. They give emphasis to birth-, death-, and net-reproduction-rates and not to mathematical growth curves. Many of the above methods are used to make projections based on census counts to date. These projections are compared and tables used to show the results. / Master of Science

Extensive investigations employing fins as extended surfaces have been conducted, but relatively little experimental work has been conducted with pins, no information is available on the heat transfer characteristics of a pin and annular fin combination, i.e., a finned pin. The increased surface area of a finned pin would promote more heat transfer. In this thesis a theoretical investigation of the basic heat transfer characteristics of a finned pin, and an experimental investigation to verify the theoretical result were conducted. 1. Theoretical investigation consists of: (1) Optimum dimensions (2) Sample calculation of optimum dimensions (3) Derivation of heat transfer equations (4) Sample calculations of heat flow-rate and temperature distribution 2. Experimental investigation consists of: (1) Set-up of experimental equipment (2) Measurements of heat flow-rate and temperature distribution (3) Comparison of theoretical results with measured results 3. Conclusions: The conclusions were based on the comparison of the two-disc finned pin with the plain pin. (1) For the two-disc finned pin employed in this thesis: Increase in heat-flow-rate: 85% Increase of effectiveness: 61% (2) In general, the increase in heat flow-rate depends on the material, dimensions, temperature difference and spacing of annular fins. / Master of Science

A procedure for analyzing a two and three dimensional truss-rigid-frame with elope deflection method is investigated in this thesis. In the first few chapters of this thesis the elope deflection equations for solving the trussed-rigid-frame problem were derived. The point of great importance in deriving slope deflection equations is that the imaginary plates or bars are added at separated domains or parts. Because of the existence of imaginary plates or bars the whole trussed-rigid-frame can be regarded as the rigid beam frame. The equations for determining the coefficients for the equivalent slope deflection equations of the separate domains can be formulated by applying the Castigliano’s theorems. The reactions and the stresses in every member of the trusses can be calculated after the reactions at the “joints” have been determined. In the last few chapters an illustrative example is given. Its solutions are checked with the solutions obtained by applying Castigliano's theorem to the whole frame. This proves that it is possible to analyze the trussed-rigid-frame by using the procedure mentioned in this thesis. The advantage in using this method is that the whole structure may be separated into domains when the number of members increases to such an extent that the capacity of a computer is exceeded. / Master of Science

Master of Science

no abstract provided by author / Master of Science

The buckling constant for neutron moderators in the shape of an elliptic cylinder, hemisphere, and"piggy-back" cylinder has been determined by experimental measurements using paraffin as a moderator. The pulsed neutron sources technique was used throughout the work; a fast neutron burst of short duration was injected into regular paraffin shapes (cylinders with diameter and height ratio equal approximately to one). An empirical curve of decay constant of the neutron population versus the buckling was obtained. The measured decay constant, λ, was fitted by the method of least square to a parabola in B² of the form: λ=Σ_av+ B²D - CB⁴ where λ= the decay constant B² = the buckling constant Σ_a = the macroscopic absorption cross section v = the neutron velocity D = diffusion coefficient C = diffusion cooling coefficient The resulting values of the diffusion parameters are: Σ_a v = 4858 ± 162 sec⁻¹ D = 25911 ± 202 sec⁻¹ cm² C = 1186 ± 2558 sec⁻¹ cm⁴ By measuring the decay constant, the buckling of the moderators with irregular shapes were determined from the above parameters. The result was in general accord with the theoretical approximations for such shapes. / Master of Science