Showing papers by "Virginia Tech published in 1970"
TL;DR: In this article, it was shown that the topological spaces which arise as duals of Boolean algebras may be characterized as those which are compact and totally disconnected (i.e. the Stone spaces); the corresponding purely topological characterization of the duals obtained by Stone is less satisfactory.
Abstract: 1. Introduction Stone, in [8], developed for distributive lattices a representation theory generalizing that for Boolean algebras. This he achieved by topologizing the set X of prime ideals of a distributive lattice A (with a zero element) by taking as a base {P a : aeA} (where P a denotes the set of prime ideals of A not containing a), and by showing that the map a i-> P a is an isomorphism representing A as the lattice of all open compact subsets of its dual space X. The topological spaces which arise as duals of Boolean algebras may be characterized as those which are compact and totally disconnected (i.e. the Stone spaces); the corresponding purely topological characterization of the duals of distributive lattices obtained by Stone is less satisfactory. In the present paper we show that a much simpler characterization in terms of ordered topological spaces is possible. The representation theorem itself, and much of the duality theory consequent on it [8, 6], becomes more natural in this new setting, and certain results not previously known can be obtained. It is hoped to give in a later paper a more detailed exposition of those aspects of the theory barely mentioned here. I should like to thank my supervisor, Dr. D. A. Edwards, for some helpful suggestions and also Dr. M. J. Canfell for permission to quote from his unpublished thesis.
604 citations
TL;DR: Viscous shock layer equations of laminar hypersonic flow past blunt body at moderate to high Reynolds numbers were given in this article, where the body was assumed to have a blunt body.
Abstract: Viscous shock layer equations of laminar hypersonic flow past blunt body at moderate to high Reynolds numbers
196 citations
TL;DR: In this paper, a mathematical conjecture about the distribution of energy levels in complex systems is given, which is much shorter than two that have been published before, and a proof is given.
Abstract: Dyson made a mathematical conjecture in his work on the distribution of energy levels in complex systems. A proof is given, which is much shorter than two that have been published before.
127 citations
TL;DR: The data in this report do not support or deny the contention that aflatoxin may be responsible for primary liver cancer, but it is found that it is possible to investigate this relationship by measuring the urinary excretion of a Flatoxin M1, which is the hydroxylated product of B1.
Abstract: So far, only circumstantial evidence has indicated that aflatoxin is involved in the aetiology of liver cancer1, but we have found that it is possible to investigate this relationship by measuring the urinary excretion of aflatoxin M1, which is the hydroxylated product of B1. The work was carried out in the Philippines and was suggested by aflatoxin analyses of foods purchased locally. We wish to make clear, however, that the data in this report do not support or deny the contention that aflatoxin may be responsible for primary liver cancer.
96 citations
TL;DR: The water-soluble, nonfluorescent dye predominating in acid solutions became deprotonized, lipophilic and fluorescent under neutral and alkaline conditions, apparently dependent upon their composition.
Abstract: Aqueous 0.1% neutral red adjusted to pH 6.5, or mixed 1:1 with seawater, produced conspicuous fluorescence in plant and animal fats while acting as a conventional stain for acidic groups including volutin. The water-soluble, nonfluorescent dye predominating in acid solutions became deprotonized, lipophilic and fluorescent under neutral and alkaline conditions. Neutral dye crystals fluoresced dull red, whereas the fluorescence was either bright lemon yellow or blue-green in lipids, apparently dependent upon their composition.
83 citations
TL;DR: Simultaneous recordings show a 1 : 1 coresspondence between song notes and respiratory movements, which indicates the duration of singing need not be limited by the volume of pre-song inspiration, rather by the composition of the air after shallow exchanges that must be predominantly of dead-space air.
79 citations
TL;DR: Fat content of milk increased with analog intake and free fatty acid and triglyceride content of serum α -lipoproteins and triglycerides of the β -lipoins were reduced in cows fed analog from those with no analog.
77 citations
Abstract: (1970). A Benefit-Cost Analysis of Auto Safety Features. Applied Economics: Vol. 2, No. 4, pp. 265-275.
75 citations
TL;DR: In this paper, a prediction of radial migration is developed and compared with experimental measurements, and the predicted trajectories were found to agree well with the measured ones, ultimately, radially migrating spheres reached an equilibrium position located approximately midway between the cylinder walls.
Abstract: Several studies have been made in Couette systems of the primary motion (angular translation and rotation) of spheres suspended in viscous liquids. Radial migration trajectories, however, have been unreported for single spheres.
In this study, a prediction of radial migration is developed and compared with experimental measurements. The predicted trajectories were found to agree well with the measured ones.
Ultimately, radially migrating spheres reached an equilibrium position located approximately midway between the cylinder walls. The model developed predicted an equilibrium position just slightly inside the midpoint, while measured equilibrium positions fell between the midpoint and 0.4, the annular thickness from the inner cylinder walls. The differences in equilibrium positions are attributed to the approximate nature of the model.
73 citations
TL;DR: In this paper, a sample of size N is taken from an equiprobable t-category multinomial distribution and the precise values of Pearson's X 2 and the likelihood ratio statistic A were computed for t = 3(1)6, N = 3 (1)12, t = 6(1)-14, N= 6( 1)2t, t=15(1-18), N = 6 (1)-28, and d.f.
Abstract: A sample of size N is taken from an equiprobable t-category multinomial distribution. The precise values of Pearson's X 2 and the likelihood ratio statistic A were computed for t = 3(1)6, N = 3(1)12; t = 6(1)14, N = 6(1)2t; t=15(1)18, N = 6(1)28. The logarithms of the tail areas were smoothed and fitted by means of quadratic expressions. Much information is given concerning the accuracy of the chi-squared fits to the distributions of X 2 and A. A table of −log10 P(χ2 > a) is given, for a = 1(1)50, and d.f. = 1(1)20. The distribution of the total number of repeats within cells is also discussed.
68 citations
TL;DR: In this article, a finite element plate bending analysis which includes the effects of transverse shear is described, and a complete displacement formulation based on the governing equations of the Reissner theory is developed for application to the bending of rectangular plates.
Abstract: A finite element plate bending analysis which includes the effects of transverse shear is described. A complete displacement formulation based on the governing equations of the Reissner theory is developed for application to the bending of rectangular plates. The finite element employed is a rectangle with 20 degrees of freedom which include both bending and shear deformation states and their interaction. Of primary importance is the ability of the finite element method to overcome certain of the anomalies found in classical plate theory. The presence of “Kirchoff shear forces” and concentrated corner reactions can be eliminated by the specification of more realistic boundary conditions. Results of several numerical examples are in excellent agreement with those of the Reissner theory for maximum displacements and for the distribution of shear stress resultants along plate edges. Also, the added transverse shear degrees of freedom allow shear deformations along an edge parallel to the edge. Thus, the vanishing edge twisting moment condition can be satisfied approximately. The formulation described offers a convenient method for approximating the Reissner theory with a discrete element approach.
TL;DR: In this article, the fracture of a known ductile polymer (polycarbonate) is investigated and it is shown that polycarbonate obeys the Dugdale model of ductile yielding by comparing measured plastic-zone sizes and displacements to theoretical predictions.
Abstract: The fracture of a known ductile polymer (polycarbonate) is investigated. It is shown that polycarbonate obeys the Dugdale model of ductile yielding by comparing measured plastic-zone sizes and displacements to the theoretical predictions. Strain-energy release rates are calculated and the critical value is shown to be one or two orders of magnitude higher than critical values for brittle polymers.
TL;DR: In this paper, a capability for predicting the interaction shock shape attending transverse injection in supersonic flow was developed for both gaseous and liquid injectants, with particular attention directed at the importance of the relation of the injectant vapor pressure to the external pressure in the vicinity of the injection port.
Abstract: This paper is concerned with the development of a capability for predicting the interaction shock shape attending transverse injection in supersonic flow. Both gaseous and liquid injectants are treated. New experimental results for liquid injection at Mach 2.1 are also presented with particular attention directed at the importance of the relation of the injectant vapor pressure to the external pressure in the vicinity of the injection port. For gaseous injection, a new analysis based on an equivalent solid-body concept is presented and substantiated by comparison with experiment over a wide range of conditions. A complementary analysis for liquid injection is also developed and shown to provide reasonable predictions for problems where significant flash vaporization occurs.
TL;DR: In this article, the effects of five levels of fiber (5 to 60% straw, equal parts of barley, rye, and wheat) and two ratios of starch to sugar (1:1 and 3:1) on the performance of young ruminating calves were investigated.
Journal Article•
TL;DR: This report describes spherical organelles that characterize a wide spectrum of mitochon-it ranges from filamentous mitochondria to varia-drial forms in different animal cells.
Abstract: Numerous reports have appeared in the literature the descriptions of this organelle have shown that that characterize a wide spectrum of mitochon-it ranges from filamentous mitochondria to varia-drial forms in different animal cells. Typically, tions of spherical organelles. This report describes
TL;DR: Successful laboratory reproduction increased with duration of captivity and was attained under standard laboratory conditions without elaborate simulation of the natural environment of the animals.
Abstract: A series of three experiments was conducted on captive pine voles to obtain basic reproductive information and to determine factors affecting repro- ductive success in the laboratory. The pine voles studied were induced ovulators, vaginal smear patterns of females paired with males were erratic, the gestation period was 24 days, a placental sign was usually evident between days 14 and 17 of pregnancy, implantation did not appear to be delayed, and a postpartum heat occurred. Successful laboratory reproduction increased with duration of captivity and was attained under standard laboratory conditions without elaborate simulation of the natural environment of the animals.
TL;DR: In this paper, a method is developed for the design of experiments with mixtures in which the mixture components are categorized (acids, bases, etc.), and each category of components contributes a fixed proportion to the total mixture.
Abstract: A method is developed for the design of experiments with mixtures in which the mixture components are categorized (acids, bases, etc.), and each category of components contributes a fixed proportion to the total mixture. The number of categories of mixture components is general (q < ∞), and each category is represented in every mixture by one or more of its member components. The experimentation is to be performed in an ellipsoidal region chosen by the experimenter, subject to the constraints placed on the components. A transformation is made to a spherical region in order that rotatable response surface designs and polynomial models can be used for estimating the response.
TL;DR: It is suggested that functional cells within an alveolus are synchronized with regard to formation and secretion of fat globules also suggests communication between these cells.
TL;DR: A reproducible isopycnic technique, in which linear density gradients of Ficoll are used, was developed for selecting synchronous daughter cells from asynchronous cultures of Chlorella for biochemical studies of the cell cycle.
Abstract: A reproducible isopycnic technique, in which linear density gradients of Ficoll are used, was developed for selecting synchronous daughter cells from asynchronous cultures of Chlorella for biochemical studies of the cell cycle.
TL;DR: The hypothesis that the rate of cellular transport is a considerably more important aspect of the pathological effects of affatoxin than the subsequent rate of metabolism is supported and support the hypothesis that a flatoxin B1 has a much greater role in the toxic lesions than aflatoxin M1.
TL;DR: The lizard, Iguana iguana appears to be a good preparation with which to study the tonic immobility response, which can be reliably induced in iguanas by a combination of inversion, restraint, and moderate pressure.
TL;DR: Weights of the ovaries, uteri, clitoral glands, testes, seminal vesicles, and preputial glands were all greater during the season of reproduction than during the remaining 5 months; thymic and adrenal weights were greatest in early autumn.
Abstract: Fifteen adult pine voles of each sex were trapped each month for a period of 1 year beginning in June 1967 and ending in May 1968. Measures of reproductive activity and various organ weights were obtained each month. Pregnant females were found only from April through October with peak numbers of pregnancies occurring in July and August. The average number of fetuses per pregnant female was 1.9. A few females had corpora lutea on their ovaries in all months except January. Weights of the ovaries, uteri, clitoral glands, testes, seminal vesicles, and preputial glands were all greater during the season of reproduction than during the remaining 5 months. Thymic and adrenal weights were greatest in early autumn.
Journal Article•
TL;DR: The evidence suggests that endproduct repression might play the major role in regulating the timing of synthesis of this enzyme during the cell cycle.