The present report describes a procedure developed for tracing C¹⁴ labeled glucose in rumen material in vitro. Twenty-five ml. samples of rumen fluid were incubated with uniformly labeled glucose for 1 1/2 hours in a closed system. The distribution of activity in both unfermented control samples and fermented samples was determined among protein and particulate material, ether extractable substances, amino acids and peptides, sugars and other neutral molecules, carbon dioxide, and methane. Samples were counted as barium carbonate following wet oxidation. Subsamples of the control and fermented samples indicated 80 to 85% recovery of C¹⁴. In these preliminary trials, additional losses were encountered among some individual fractions. Data indicated differences between fermentative activity of the two samples from different animals. In Trial I, 29% of 14 the fermented glucose C¹⁴ was recovered in the protein-particulate fraction, 15.6% in the carbon dioxide, and 10.5% in the ether extract. In Trial II, the ether extractable fraction contained 23.5% of the activity, 14.5% was recovered in the protein-particulate fraction, and 14.3% in the carbon dioxide. / M.S.

This investigation is concerned with the flexural response of linear viscoelastic plates of constant thickness. Fundamental equations for both quasi-static and dynamic response of such plates are developed and solved for important cases of each. The term quasi-static ls used to indicate that Inertia forces due to deformation are neglected. These are included, of course, in the dynamic analysis. Solutions of the quasi-static equation are compared with experimental results obtained by measuring the deflection of a test plate made of Plexiglas. The basic viscoelastic stress-strain relations used in the derivation of the fundamental plate equations are taken in the form of a differential time operator equation. Use of this equation leads to results that are In a convenient form for reduction to a particular material such as a Kelvin or a Maxwell plate. Using a generalized virtual work principle based upon irreversible thermodynamic considerations the fundamental plate equation, including shear effects, ls established. The procedure involved ls that of determining a stationary value of a certain operational invariant by means of the calculus of variations. A simplified form of this equation, omitting the shear effects, is deduced and solutions for various load conditions obtained. An extended version of this simplified form which includes inertia effects due to deformation is developed by the principle of correspondence. This is used to study free vibrations of rectangular viscoelastic plates simply supported on all edges. Solutions of the simplified form of the fundamental equation for the case of so-called proportional loading, I.e. when the load function is the product of a space function multiplied by a time function, are given in terms of the equivalent elastic solution multiplied by a function of time. For more general types of loading the deflection and the load are expanded Into suitable infinite series and these series representations are inserted directly into the previously mentioned variational expression of the generalized virtual work principle. This leads to a set of ordinary differential situations in time the unknowns of which are the coefficients of the deflection expansion. These equations, as were the similar ones arising in the case of proportional loading, are solved by the Laplace transform method of the operational calculus. As an example of such a general loading the case of a moving line load on a rectangular plate is worked out. As a means of establishing a correlation between the deflection predicted by the analytical solution and actual deflections of Inelastic plates a set of static load tests were carried out on a square plate made or Plexiglas. The results are plotted and a comparison of the theoretical and experimental values given. The problem of determining the dynamic response of viscoelastic plates is treated using the method given above for solving the case of general loading for the quasi-static deflection. Under the assumption of incompressibility of the plate material explicit solutions in terms of the physical parameters involved are presented and discussed. For compressible plate materials methods are developed to give approximate solutions the accuracy of which depends on the degree of approximation used in determining the roots of certain cubics appearing in the transformed form of the governing dynamics equation. Conditions for the dynamic solutions to be oscillatory are indicated. / Ph. D.

The process of C. K. Bradsher for preparing mesosubstituted anthracene and 1,2-benzanthracene derivatives has been widely extended. The purpose of this research was to extend this process to the thiophene series, in addition to continuing some work on the 9-(dimethyl)- phenylanthracene series and some newly developed l,2-dimethyl-10-phenyl)-anthracene series. 2'-Thienyl-2-benzylbenzophenone was prepared and cyclized to 9-(2-thienyl)-anthracene by the conventional methods in good yields. 3'-Thienyl-2-benzylbenzophenone was prepared in a different way, indirect and tedious. Thiophene was iodinated to tetraiodothiophene and tetraiodothiophene was reduced with aluminum-amalgam to 3-iodothiophene. 3-Thienylmagnesiumiodide was prepared by the entrainment technique and condensed with 2-cyanodiphenylmethane to 3'-thienyl-2-benzylbenzophenone. This ketone was cyclized to 9-(3'-thienyl)-anthracene by the standard acid mixture. 2-(1-Naphthylmethyl)-phenyl-2-thienylketimine formed from the condensation between 2-(1'-naphthylmethyl)- benzonitrile and 2-thienylmagnesiumbromide resisted hydrolysis to the corresponding ketone but cyclized quantitatively to 10-(2-thienyl)-l,2-benzanthracene. Following the classical Bradsher process, the reaction between 2-thienylmagnesiumbromide and o-chlorobenzaldehyde was unsuccessful because the hydrol formed was so reactive that it polymerized rapidly and ended up with tars. A cross-condensation reaction between 2-ethynylmagnesium bromide and o-chlorobenzylchloride was utilized to give the expected 2-(2'-chlorobenzyl)- thiophene in one step. This new procedure has been widely extended to the other series. It is preferred to. the conventional Bradsher process and the Friedel-Crafts method in terms of time, chemicals, and unequivocal products formed. 2-(2'-Chlorobenzyl)-thiophene so formed by the new procedure was converted by von Braun reaction to the corresponding nitrile and the nitrile was allowed to react with phenylmagnesiumbromide to give 2-(2-thienylmethyl)-benzophenone. The above ketone was cyclized almost quantitatively to 4-phenyl-thiophanthrene. The thiophene-containing ketones prepared in this research are very viscous oils. In order to have crystalline derivatives for identification purposes these ketones were oxidized to the corresponding diketones. 2-Thienyl-2-benzylbenzophenone and 2-(2'-thienylmethyl)- benzophenone gave the identical diketone, 2-benzoyl-2'- thienyl-benzophenone. 3 1 -Thienyl-2-benzylbenzophenone was oxidized to anthraquinone by using 25% sulfuric .acid, acetic acid and sodium dichromate. The formation of anthraquinone indicates that the monoketone cyclized first and then split off the thiophene ring. Apparently, the 3-thienyl group is more susceptible to oxidation than the 2’-thienyl group. A study of the oxidation of anthracene derivatives for structure proof was made using 9-phenylanthracene as a model compound. It was oxidized to 10-phenyl-10-hydroxyanthrone which resisted further oxidation to anthraquinone. It is obvious that the tertiary alcohol system stabilized the phenyl ring. In continuing the work on the 9-(dimethyl)-phenylanthracene series, the yields of three ketimine salts and one ketone were improved. Satisfactory analytical data was obtained for 2’,6’-dimethyl-2-benzylbenzophenone. In an attempt to overcome the steric effects offered by 2,6-ortho groups, 2-(2',3'-dimethylbenzyl)-benzonitrile was prepared. The starting material for this series, l-bromo-2,3-dimethylbenzene has been prepared in 47% yield by diazotization in comparison with the previous yield of 30%. / Doctor of Philosophy

Molybdenum-permalloy powder cores are manufactured to fall within required permeability limits. However, these limits are sufficiently broad to cause sizeable labor loss in adjusting the number of turns for required inductance values; for example, an Arnold Engineering Company A-930157-2 core with a 1000-turn winding may range from 135 to 179 millihenries. It is therefore highly desirable that large-scale users of these cores grade them into groups by some simple inductance test. This permits cores to be wound with a predetermined number of turns, thereby essentially eliminating the labor of adjusting the number of turns of the winding to meet required inductance values. The following work has been accomplished: (1) The design and construction of a multi-turn split jig suitable for rapid testing of cores to permit economical grading. (2) The construction of a modified Owen alternating-current bridge with component capacitor and resistor values such that the inductance of the unwound cores and the finished coils may be read directly from one decade resistance box in microhenries and millihenries, respectively. (3) The preparation of a family of curves each representing a group of graded cores showing the number of turns required to yield a given inductance. Sketches and photographs of a core, finished coil, multi-turn split jig, and the test circuit are included. / Master of Science

"Factors Which Affect Mining of the Lower Mississippian Coals in Montgomery County, Virginia" ie a study ot the Merrimac and Langhorne seams of the Price formation in Montgomery County, Virginia. The main reference used in the review of literature was Bulletin XXV of the Virginia Geolog1cal Survey by Marius R. Campbell. The review of literature discusses geologic formations and structure and the coal as seen in various prospect and mine openinga by Campbell. The author visited mines during the field investigation and analyzed samples of coal collected at the mines. He discusses past mining operations in Montgomery County and has traced all available mine maps of past mining operations. These are filed as part of the thesis. Core drillings were also investigated by the author and reported depths of the coal in the Blacksburg syncline ere entered in Table III and Figure I. An investigation was also made into mining methods used in Montgomery County including a discussion of explosive gases encountered in mining the Merrimac seam. The author discusses the results of the investigation in the conclusions. Be ia convinced the coals of the Valley fields, although of poor quality, will becane increasingly valuable as anthracite deposit in Pennsylvania and bituminous deposits in Southern West Virginia and southwest Virginia are depleted. / Master of Science

The 250 Kev Cockroft - Walton accelerator currently under construction at Virginia Polytechnic Institute is to be used as a pulsed neutron source. The time dependence of neutron flux, energy spectrum as a function of time, and various reactor parameters such as Fermi Age, slowing dotm time, and diffusion length in graphite will be measured using the pulsed source method. This thesis is a Monte Carlo calculation of the results to be expected in such an experiment. The neutron flux and energy spectrum was calculated at 1, 2, 5, and 10 microseconds after a burst of fast neutrons. The neutrons were “tracked" to thermal and the Fermi Age and slowing down time were determined. / Master of Science

Approximate formulae are derived for obtaining confidence intervals for the probabilities of a multinomial distribution. The approach used is to consider the Chi-square goodness of fit statistic as a function of the population parameters and to invert this function to obtain a set of simultaneous confidence intervals for the parameters The confidence coefficient for the set of simultaneous confidence intervals obtained by this procedure is conservative, i.e., the true probability that every interval covers its corresponding parameter will in general be greater than the coefficient obtained by this method. As the sample size increases the intervals will converge on the population parameters and will estimate them exactly in the limit. / Master of Science

This thesis presents the work performed to evaluate the susceptibility of AISI 304 to stress-corrosion cracking in terms of time to crack nucleation and rate of crack propagation. U-bend specimens were exposed to magnesium chloride solutions boiling at atmospheric pressure for some predetermined time. The concentrations of magnesium chloride employed were 40, 42, and 44 per cent by weight. After exposure, specimens were microscopically examined and crack depths were measured and recorded. It was found that a straight-line relationship existed between maximum crack depth and exposure time which may be expressed by the empirical equation Log t = D/M+ Log C. The constants M and C are characteristic of the conditions of exposure and increase with a decrease in chloride ion concentration. The rate of crack propagation was found to be inversely proportional to time. Microscopic examination revealed that cracking was both transgranular and intergranular. There are indications that intergranular cracking was more pronounced at the low concentrations of the chloride ion. The results obtained justify the continuation of the work to determine factors affecting susceptibility in terms of constants M and C. / Master of Science

The dielectric dispersion of poly(vinyl acetate) solutions was studied in an attempt to relate this behavior to the chemical nature of the material. The bridge method was employed in which capacitance measurement of solutions were made over a frequency range of 400 cycles to 500 kilocycles. The results of these experiments indicate that a vinyl type material possesses greater flexibility than cellulose derivatives in solution and, thus, the magnitude of capacitance changes over a frequency range is considerably reduced. Because of the very small changes in capacitance, reproducible results are difficult to obtain and definite conclusions as to the relation of dispersion to molecular weight are impossible. Dielectric dispersion studies were made on solutions of poly(vinyl acetate) in dioxane, ethylene chloride and acetone. / Master of Science

Since the Eighteenth century, a great amount of research has been done using the elastic analysis technique in the field of curved structures. Recently the question of behavior beyond the yielding range has become increasingly important. By applying the methods of plastic analysis, the collapse load of a structure can be determined, and also the stress distribution and the deflection, just before collapse, can be calculated. However the evolution of the stress distribution and the deflection at any section of the structure between the load causing first yielding and the collapse load is still an unsolved problem. Concerning the problem of evolution of the stress distribution in the inelastic range, most literature relies on the simple plastic theory in which the effect of the axial force on the formation of a plastic hinge is neglected. In fact this conception is in serious error in some cases, especially when the curved structure is a shallow arch, the stresses developed are apparently governed by the axial force. Literature considering the combined effects of bending moment and axial force is very rare. In this thesis, the author proposes a new method, incorporating effects of both axial force and bending moment, of determining the evolution of stress distributions and the deflections in the inelastic range. The thesis includes three parts. In the first to parts, the theory for the stress analysis and for the deflection of a rectangular section is presented. The third part contains three examples to illustrate the use of the new method in practical engineering problems. / Master of Science