Showing papers by "Virginia Tech published in 1974"
TL;DR: Quantitative and qualitative examination of the fecal flora of 20 clinically healthy Japanese-Hawaiian males was carried out by using anaerobic tube culture techniques, and differential characteristics of previously unreported species are presented.
Abstract: Quantitative and qualitative examination of the fecal flora of 20 clinically healthy Japanese-Hawaiian males was carried out by using anaerobic tube culture techniques Cultural counts were 93% of the microscopic clump counts Isolated colonies were selected in a randomized manner to give an unbiased sampling of the viable bacterial types Each isolate was characterized for species identification From a total of 1,147 isolates, 113 distinct types of organisms were observed Statistical estimates indicate that these types account for 94% of the viable cells in the feces The quantitative composition of the flora of this group of people, together with differential characteristics of previously unreported species, is presented for those kinds of bacteria which each represented at least 005% of the flora
1,123 citations
TL;DR: This chapter discusses the history ofOptimal Guidance and Control Synthesis for Maneuverable Lifting Space Vehicles, which began with the publication of the VASP manual in 1972.
Abstract: 1 Hoffman, W. C, Zvara, J., and Bryson, A. E., Jr., "A Landing Approach Guidance Scheme for Unpowered Lifting Vehicles," Journal of Spacecraft and Rockets, Vol. 7, No. 2, Feb. 1970, pp. 196-202. 2 Duiven, E. M., "Quadratic Cost-Re-Entry Guidance Laws," Internal Memo 2-5482-0100-020, Dec. 1969, Aerospace Group, Boeing Co., Seattle, Wash. 3 Kovatch, G., "Optimal Guidance and Control Synthesis for Maneuverable Lifting Space Vehicles," Transactions of the 9th Symposium on Ballistic Missile and Space Technology, Vol. 1, Air Force Command, San Diego, Calif., 1964, pp. 327-379. 4 Glover, L. A. and Hagan, J. C, "The Motion of Ballistic Missiles," TG1164, July 1971, The Johns Hopkins University, Applied Physics Lab., Baltimore, Md. 5 White, J. S. and Lee, H. Q., "Users Manual for the Variable Dimension Automatic Synthesis Program (VASP)," TM X-2417, Oct. 1971, NASA. 6 Anderson, B. D. O. and Moore, J. B., Linear Optimal Control, Prentice-Hall, Englewood Cliffs, N.J., 1971. 7 Bryson, A. E. and Ho, H. C, Applied Optimal Control, Blaisdell, Waltham, Mass., 1969. 8 Kwakernaak, H. and Si van, R., Linear Optimal Control Systems, Wiley, New York, 1972.
253 citations
TL;DR: In this article, the authors focus on the reasons which individuals have for participating in adult education courses, focusing mainly on the development of survey instruments, and little or no data regard the reasons for participation in these courses.
Abstract: Recent research studies on the reasons which individuals have for participating in adult education courses have primarily focused on the development of survey instruments. Little or no data regard ...
223 citations
TL;DR: In this article, a model of an anarchistic society is introduced and its implications for the distribution of income are considered, where the economy is assumed to allocate one unit of an all-purpose completely divisible good to each individual in society.
128 citations
127 citations
TL;DR: In this paper, the spectral properties of the time-independent linear transport operator A are studied in its natural Banach space L 1(D × V), where D is the bounded space domain and V is the velocity domain, and the various cross sections in K and the total cross section are piecewise continuous functions of position and speed.
Abstract: In this paper, spectral properties of the time‐independent linear transport operator A are studied. This operator is defined in its natural Banach space L 1(D × V), where D is the bounded space domain and V is the velocity domain. The collision operator K accounts for elastic and inelastic slowing down, fission, and low energy elastic and inelastic scattering. The various cross sections in K and the total cross section are piecewise continuous functions of position and speed. The two cases ν0>0 and ν0=0 are treated, where ν0 is the minimum neutron speed. For ν0=0, it is shown that σ(A) consists of a full half‐plane plus, in an adjoining strip, point eigenvalues and curves. For ν0>0, σ(A) consists just of point eigenvalues and curves in a certain half‐space. In both cases, the curves are due to purely elastic ``Bragg'' scattering and are absent if this scattering does not occur. Finally the spectral differences between the two cases ν0>0 and ν0=0 are discussed briefly, and it is proved that A is the infinitesimal generator of a strongly continuous semigroup of operators.
115 citations
TL;DR: In this article, the behavior of 21 Holstein cows was studied in feeding and free stall areas by time-lapse photography, and it was found that dominant cows preferred to succeed each other and occupy adjacent stalls.
108 citations
TL;DR: Although thousands of experiments have been run on the “bacterial fecal flora,” it is inadequately characterized and the factors which control its development and its relationships with the host are unknown; since 1960, bacteriologists have been able to culture up to 85% of the cells present and make some progress in characterizing the flora.
107 citations
TL;DR: Estimates are made of the cost and effectiveness of available retrofit devices to determine the combination of devices applied to specific model year automobiles which will reach various specified emission reduction goals at least cost.
Abstract: Estimates are made of the cost and effectiveness of available retrofit devices. These estimates are used in a linear programming model to determine the combination of devices applied to specific model year automobiles which will reach various specified emission reduction goals at least cost. The results are presented in terms of the South Coast Air Basin (Los Angeles) in 1975. A method of generalizing the results to other air basins is presented in an appendix.
90 citations
83 citations
TL;DR: In this paper, a numerical perturbation method is proposed for the determination of the nonlinear forced response of structural elements when modal interactions take place due to the complicated nature of the response.
Abstract: A numerical-perturbation method is proposed for the determination of the nonlinear forced response of structural elements. Purely analytical techniques are capable of determining the response of structural elements having simple geometries and simple variations in thickness and properties, but they are not applicable to elements with complicated structure and boundaries. Numerical techniques are effective in determining the linear response of complicated structures, but they are not optimal for determining the nonlinear response of even simple elements when modal interactions take place due to the complicated nature of the response. Therefore, the optimum is a combined numerical and perturbation technique. The present technique is applied to beams with varying cross sections. ~ 4Y large-amplitude deflection of a beam or a plate which is restrained at its ends or along its edges results in some midplane stretching/One must account for this stretching with nonlinear strain-displacement relationships. The nonlinear equations of motion describing this situation were the basis of a number of earlier investigations and are the basis for the present paper as well. The purpose of the present paper is to present a new scheme for determining the response to a harmonic excitation. Emphasis is placed on the case when the frequency of the excitation is near a natural frequency. A convenient way to attack this nonlinear problem involves representing the deflection curve or surface with an expansion in terms of the linear, free-oscillation modes. The deflection is then determined in two steps. First, the damping, the forcing, and the nonlinear terms are deleted and the linear modes (eigenfunctions) and natural frequencies (eigenvalues) are determined. Second, the time-dependent coefficients in the expansion are obtained from a set of coupled, nonlinear, ordinary, second-order differential equations, the linear modes being used to determine the coefficients in these equations. (The procedure is described in detail in Sec. II.) Generally, one cannot obtain the linear modes analytically for structural elements having complicated boundaries and composition, and one cannot easily determine the character of the timedependent coefficients through numerical integration of the set of nonlinear equations. (The results obtained in the present numerical example are typical of the complicated manner in which the steady-state amplitudes of the various modes making up the response can vary with the amplitude and the frequency of the excitation.) Consequently, an optimal procedure involves a numerical method to determine the linear, free-oscillation modes and an analytical method to determine the time-dependent coefficients. The present procedure combines either a finiteelement or a finite-difference method with the method of multiple scales (see, for example, Ref. 1). The following brief review mentions representative examples of the work that was and is
TL;DR: In this paper, a general procedure is presented for the nonlinear analysis of the forced response of structural elements to harmonic excitations, and the results reveal that exciting a higher mode may lead to a larger response in a lower interacting mode.
Abstract: A general procedure is presented for the nonlinear analysis of the forced response of structural elements to harmonic excitations. Internal resonances (i.e., modal interactions) are taken into account. All excitations are considered, with special consideration given to resonant excitations. The general procedure is applied to clamped‐hinged beams. The results reveal that exciting a higher mode may lead to a larger response in a lower interacting mode, contrary to the results of linear analyses.
TL;DR: Results indicated that student behavior change influenced the teacher's behavior and it is suggested that students possess potent reinforcing properties for teachers and that students should be trained to be effective students.
Abstract: The relationship between student behavior change and teacher reactions to the change was investigated. One fifth-grade teacher served as the subject and two students in her class were employed as teacher change agents. In a multiple baseline design, the students' disruptive behavior (the independent variable) was modified without the teacher's knowledge. The teacher's reactions toward the students (the dependent variable) was monitored on several dimensions including: teacher behavior, teacher attitude toward students, and the quality of teacher verbal statements. Results indicated that student behavior change influenced the teacher's behavior. Implications are that students possess potent reinforcing properties for teachers and that students should be trained to be effective students.
TL;DR: Three isolates of the human and animal pathogen Campylobacter fetus ss.
Abstract: Three isolates of the human and animal pathogen Campylobacter fetus ss. jejuni (Vibrio fetus) were obtained from 165 poultry meat samples purchased from local retail stores.
TL;DR: A model for a uric acid/urate ion sink which might be associated with ionic and osmotic balances is proposed, and some evidence for its existence is discussed.
Abstract: The effects of nitrogen balance on uric acid/urate, K+ and Na+ storage or mobilization were examined in the American cockroach Periplaneta americana (L.). Cockroaches on a high nitrogen diet increased in whole body uric acid/urates, K+ and Na+. Those on a semi-starvation diet maintained fairly constant levels of uric acid/urates, K+ and Na+. However, those on a low nitrogen diet mobilized stored uric acid/urates and K+, but not Na+. Analyses for uric/urates K+, Na+, Ca2+ and Mg2+ in fat body tissue from insects maintained on 12 diets containing different concentrations and sources of dietary nitrogen showed that only K+ concentration could be correlated with fat body uric acid/urate storage. Whole body storage and mobilization of uric acid/urates, K+ and Na+ were reflected in the faecal/dietary ratios of K+ and Na+. A model for a uric acid/urate ion sink which might be associated with ionic and osmotic balances is proposed, and some evidence for its existence is discussed.
TL;DR: Microminerals including fluorine, iodine, iron, aluminum, selenium, manganese, copper, zinc, strontium, lead, and cobalt were determined in the enamel and dentin portions of permanent, sound teeth from 175 patients in Virginia.
Abstract: Microminerals including fluorine, iodine, iron, aluminum, selenium, manganese, copper, zinc, strontium, lead, and cobalt were determined in the enamel and dentin portions of permanent, sound teeth from 175 patients in Virginia. Neutron activation and atomic absorption were used in the analyses. Concentration of the elements was related to tooth portion, age, and sex of the patient.
TL;DR: In this paper, the average kinetic and separation energies of nucleons in these nuclei are deduced, and results of and comments on the radiative correction procedures used in the data analysis are also discussed.
Abstract: Data and interpretation are presented for inelastic electron scattering in the quasielastic region from nine target nuclei ranging from lithium to lead at an incident energy of 500 MeV and a scattering angle of 60\ifmmode^\circ\else\textdegree\fi{}. The average kinetic and separation energies of nucleons in these nuclei are deduced. Results of and comments on the radiative correction procedures used in the data analysis are also discussed.[NUCLEAR REACTIONS $^{6}\mathrm{Li}(e,{e}^{\ensuremath{'}})$, $^{12}\mathrm{C}(e,{e}^{\ensuremath{'}})$, $^{24}\mathrm{Mg}(e,{e}^{\ensuremath{'}})$, $^{40}\mathrm{Ca}(e,{e}^{\ensuremath{'}})$, $^{58.7}\mathrm{Ni}(e,{e}^{\ensuremath{'}})$, $^{89}\mathrm{Y}(e,{e}^{\ensuremath{'}})$, $^{118.7}\mathrm{Sn}(e,{e}^{\ensuremath{'}})$, $^{181}\mathrm{Ta}(e,{e}^{\ensuremath{'}})$, $^{208}\mathrm{Pb}(e,{e}^{\ensuremath{'}})$, $E=500$ MeV, $\ensuremath{\theta}={60}^{\ensuremath{\circ}}$; measured $\ensuremath{\sigma}(E)$; deduced nucleon separation and kinetic energies in Fermi gas model.]
TL;DR: In this article, the authors examined the influence of the shape of the mean-velocity profile on the attenuation rate of acoustic propagation through a lined two-dimensional duct and found that the results from the "turbulent" boundary-layer profiles differ significantly from the results of the other profiles even when compared on the basis of displacement thickness.
TL;DR: Two generations of Japanese quail were weighed in order to estimate genetic parameters of body weight throughout the growth phase of the life cycle and sexual dimorphism became evident at the age of sexual maturity.
TL;DR: In this article, the authors analyzed the wave propagation in two-dimensional hard-walled ducts with sinusoidal walls and showed that neither of these resonating modes could occur without strongly generating the other.
Abstract: The method of multiple scales is used to analyze the wave propagation in two-dimensional hard-walled ducts with sinusoidal walls. For traveling waves, resonance occurs whenever the wall wavenumber is equal to the difference of the wavenumbers of any two duct acoustic modes. The results show that neither of these resonating modes could occur without strongly generating the other.
TL;DR: The relationship between F and its own tail area sheds further light on the relationship between Bayesian and "Fisherian" significance as mentioned in this paper, and F too can be treated as a non-Bayesian criterion and is almost equivalent to G.
Abstract: Compromises between Bayesian and non-Bayesian significance testing are exemplified by examining distributions of criteria for multinominal equiprobability. They include Pearson's X2, the likelihood-ratio, the Bayes factor F, and a statistic G that previously arose from a Bayesian model by “Type II Maximum Likelihood.” Its asymptotic distribution, implied by the theory of the “Type II Likelihood Ratio,” is remarkably accurate into the extreme tail. F too can be treated as a non-Bayesian criterion and is almost equivalent to G. The relationship between F and its own tail area sheds further light on the relationship between Bayesian and “Fisherian” significance.
TL;DR: The macromineral concentrations in enamel and dentin from 175 permanent, sound teeth were related to age, sex, and number of DMFT in the patients, and calcium, phosphorus, chlorine, and potassium concentrations were greater inEnamel than in Dentin, but magnesium was higher in dentin.
Abstract: The macromineral concentrations in enamel and dentin from 175 permanent, sound teeth were related to age, sex, and number of DMFT in the patients. Calcium, phosphorus, chlorine, and potassium concentrations were greater in enamel than in dentin, but magnesium was higher in dentin. Analytical methods were compared for four elements.
TL;DR: In this paper, a new approach based on the magnetic vector potential was developed for the solution of flux penetration and eddy current problems in nonlinear ferromagnetic materials, which is useful in the sinusoidal time varying cases.
Abstract: A new approach, based on the magnetic vector potential, is developed for the solution of flux penetration and eddy current problems in nonlinear ferromagnetic materials. The model obtained for this diffusion problem is useful in the sinusoidal time varying cases, and can be extended to the general time varying cases. The model is applied to the problem of flux penetration and determination of losses in ferromagnetic bars used for starting and damping in large synchronous motors and generators. These machines are mostly found in hydro-electric pumped storage power stations. The results consist of real and reactive power losses, equivalent resistance and reactance, distribution of induced currents and flux penetration. A comparison of results with previous authors' work is given. Good agreement between experimental results and simulated ones is established concerning loss calculations. The developed method is best suited for use in cases involving complicated contours of ferromagnetic materials and general boundary conditions. Therefore, the method is useful in rotating machine applications.
TL;DR: The physiological effects of feeding Aroclor 1254 to mature male white mice at dietary levels of 62.5, 250, and 1000 ppm for two weeks are reported in this article.
Abstract: The physiological effects of feeding Aroclor 1254 to mature male white mice at dietary levels of 62.5, 250, and 1000 ppm for 2 weeks are reported. Pentobarbital-induced sleeping time and food consumption were reduced and liver weight was increased in the 250 ppm and 1000 ppm groups. Serum corticosterone was elevated at all levels of PCB treatment; whereas, only exposure to 1000 ppm resulted in heavier adrenal glands. Weights of the testes, preputials and vesicular glands were not significantly affected by PCB ingestion.
TL;DR: It is apparent that computers are being used as design aids although few practitioners are willing to delegate the whole job to a computer at this time.
Abstract: A wide variety of computer programmes for solving facilities design problems have been developed. Since the arrival of programmes like CORELAP and CRAFT in the early sixties, a variety of aspects of this problem have been approached using computer technology. Engineers and architects appear to be the developers and users of most of these programmes This paper describes the results of a survey attempting to summarize this activity both in Europe and North America where most of the work is being conducted. Computers are being used for both data reduction and graphics associated with the design of buildings which range from industrial plants to hospitals and schools It is apparent that computers are being used as design aids although few practitioners are willing to delegate the whole job to a computer at this time. Both time shared programmes and the more conventional batch processing are summarized. Heuristics include algorithms which vary in philosophy. The advantages and limitations to construction algor...