Showing papers by "Ben-Gurion University of the Negev published in 1981"
01 Jan 1981
TL;DR: In this article, the authors developed composite relations for the variation of the heat transfer coefficient along the plate surfaces, and the mathematical development and verification of such composite relations as well as the formulation and solution of the optimizing equations for the various boundary conditions of interest constitute the core of the presentation.
Abstract: While component dissipation patterns and system operating modes vary widely, many electronic packaging configurations can be modeled by symmetrically or asymmetrically isothermal or isoflux plates. The idealized configurations are amenable to analytic optimization based on maximizing total heat transfer per unit volume or unit primary area. To achieve this anlaytic optimization, however, it is necessary to develop composite relations for the variation of the heat transfer coefficient along the plate surfaces. The mathematical development and verification of such composite relations as well as the formulation and solution of the optimizing equations for the various boundary conditions of interest constitute the core of this presentation.
481 citations
Book•
01 Jan 1981277 citations
TL;DR: In this article, a 30 km wide shear belt of subparallel faults along the western coast of the Gulf of Elat has been identified based on offsets of magmatic bodies and lithological contacts in rocks of Precambrian age and the cumulative displacement, measured independently at several localities across the belt attains a total of 24 km.
230 citations
206 citations
TL;DR: In this paper, it is shown that up to 80% improvement in the shroud power augmentation can be obtained by the use of an appropriate ring-shaped flap and proper bleeding of the shroud's external flow into its inner rear part.
205 citations
TL;DR: In this article, the authors measured local hold-up and liquid recirculation rate in an air-lift reactor with two types of gas spargers using a manometric technique.
Abstract: Measurements of local hold-up and liquid recirculation rate in an air-lift reactor were performed with two types of gas spargers using a manometric technique. A simple exponential function correlated properly the liquid velocity measured to the gas flow rate. The local hold-up varied appreciably along the column and showed a maximum in most of the cases. A simple linear relationship correlated the local gas velocity with the total flow rate of the mixture.
136 citations
TL;DR: In this article, the patter of apatite ages reveals non-uniform uplift between fault-bound blocks, with greater uplift parallel to the Gulf of Suez, an area of extensional tectonics, and less uplift in the area dominated by strike slip movements.
121 citations
TL;DR: In this article, the authors studied the kinetics of the hydrogenation reaction of uranium over a wide range of pressures (10 2 −10 7 Pa) and temperatures (0 −500 °C).
Abstract: The kinetics of the hydrogenation reaction of uranium were studied over a wide range of pressures (10 2 –10 7 Pa) and temperatures (0–500 °C). The results are discussed in terms of two possible models: model 1, hydrogen diffusion through a protective product hydride layer; model 2, hydride growth at the hydride-metal interface. A two-dimensional ( i.e. pressure-temperature) grid of the experimental data was successfully fitted to the pressure-temperature rate relations derived from model 2. This model relates the microscopic distribution of hydrogen atoms in the metal to the phase transformation probability, from which the pressure-temperature dependence of the hydride growth rate is obtained. The model also qualitatively accounts for the negative apparent activation energy reported in the literature for the hydrogenation of the powdered metal.
88 citations
TL;DR: In this paper, spatial correlation analysis has been applied to Namib rainfall, in an attempt to identify possible patterns of the spatial organization of localized storms in this area, and the utility of the above technique for areas with only sparse raingauge networks is explained.
Abstract: Spatial correlation analysis has been applied to Namib rainfall, in an attempt to identify possible patterns of the spatial organization of localized storms in this area. The utility of the above technique for areas with only sparse raingauge networks is explained. Results indicate that convective storms are not randomly scattered in space but, tend to form at preferred distances from each other, around 40-50 and 80-100 km, with no preferred locations of, or directions between, storms. Benard cells are mentioned as possibly imposing the inferred organization of convective storms in space.
82 citations
TL;DR: In this article, a class of models, which admit an Abelian two-parameter group of isometries, is considered in detail, and exact solutions of the Einstein field equations are presented.
78 citations
TL;DR: Clustering showed the developmental shift from color to form to concept, while cued recall showed conceptual superiority at all ages, as well as the difficulty of abstraction in encoding and the function of predictability in retrieval.
TL;DR: In this paper, the omega phase in pure Zr formed at 300 K under high pressure of 6.0 G Pa was examined using high resolution dark-field electron microscopy and selected area diffraction.
TL;DR: A relaxation method is described to obtain a function such that when this function is subtracted from the original image the seams are eliminated, but the details are not affected or blurred.
TL;DR: In this paper, two basic approaches, the Lagrangian method and the fixer! cycle method, have been suggested for solving the problem of multi-item inventory systems with budgetary constraints.
Abstract: Two basic approaches, the Lagrangian method and the fixer! cycle method, have been suggested for solving the problem of multi-item inventory systems with budgetary constraints. The two solution procedures are compared. A simple algorithm is developed to test which solution procedure would result in a lower cost.
TL;DR: In this article, a one-dimensional microscopic quantum mechanical model is used to inquire whether it is possible to enhance the desorption rate by employing a laser to induce vibrational excitation of the chemisorptive bond.
01 Apr 1981
TL;DR: The adsorption from various solutions of triple-helical soluble collagen monomers to solid surfaces was studied by labeling the collagen with 1251 amino acid residues and finding that it is irreversible and little dependent on pH and ionic strength but increasing enormously as the surface is made more hydrophobic as discussed by the authors.
Abstract: The adsorption from various solutions of triple-helical soluble collagen monomers to solid surfaces was studied by labeling the collagen with 1251. Adsorption to glass, siliconized glass, and Teflon, from aqueous solutions at various pH and ionic strength, was determined at collagen concentrations from 2 to 25 μg/ml. Adsorption was shown to be irreversible and little dependent on pH and ionic strength but increasing enormously as the surface is made more hydrophobic. Surface denaturation of the collagen by heat results in a substantial loss of material. The kinetics of adsorption suggest that the adsorption process may be selective and that not all collagen molecules which reach the surface are immediately adsorbed. Checking these results with earlier measurements of adsorbed layer thickness, a model for collagen adsorption is proposed.
TL;DR: In this article, a general equilibrium model of an economy with cities, farms and free migration of population is constructed, where cities produce internationally traded goods via production functions subject to economies of scale They also produce housing and a local public good.
TL;DR: In this article, a number of new RGa 6 compounds with the tetragonal PuGa 6 structure are reported and the lattice parameters of these compounds decrease on replacing the rare earth atoms in the order of increasing atomic number.
Abstract: A number of new RGa 6 compounds (where R is a rare earth atom) with the tetragonal PuGa 6 structure are reported. The lattice parameters of these compounds decrease on replacing the rare earth atoms in the order of increasing atomic number. The RGa 6 compounds are formed by a peritectic reaction at temperatures which decrease in the order mentioned. The thermal instability of these compounds as expressed by the decrease in peritectic temperature is discussed. Also the failure to detect these intermetallic compounds by other investigators is explained.
TL;DR: Generally, guards' beliefs ate less punitive than could be expected from previous literature and three independent factors emerge from a factor analysis: belief in the rehabilitation potential of prisoners, belief inThe rehabilitative potential of the prison, and belief in a guard's supportive role.
Abstract: The study investigates prison guards' beliefs concerning the prison, the prisoners, and their own. role and the relationships between these beliefs and other variables. Subjects came from four maximum security Israeli prisons (N = 370). Generally, guards' beliefs ate less punitive than could be expected from previous literature. A considerable variance in guards' beliefs is revealed. Three independent factors emerge from a factor analysis: belief in the rehabilitation potential of prisoners, belief in the rehabilitative potential of the prison, and belief in the guard's supportive role. The relationships between these beliefs and background and work-related variables are examined and discussed.
TL;DR: In this article, the formation of saddle-type azeotropes is explained in terms of the molecular interactions in the solutions and in the pure liquids, and interaction weakening and interaction strengthening effects are defined which tend to be associated with the formation.
TL;DR: Preliminary results show that the number and survival of seedlings within the diggings of the Indian crested porcupine (Hystrix indica) is usually higher than in the surrounding area.
Abstract: Preliminary results show that the number and survival of seedlings within the diggings of the Indian crested porcupine (Hystrix indica) is usually higher than in the surrounding area. Species like Erodium hirtum (Willd.) (hemicryptophyte), Helianthemum vesicarium Boiss. (perennial), and Diplotaxis harra (Forssk.) Boiss. are conspicuous by their appearance in the diggings of the porcupine more than between the diggings. In contrast there are plants like Helianthemum ledifolium (L.) Mill. (annual), that appear in high numbers outside the diggings. In the case of Erodium hirtum, it appears that the porcupines help in rejuvenating the population. The porcupines feed on the older underground plant bulbs and the pockets formed by their diggings are convenient habitats for germination and growth of the young seedlings.
TL;DR: 6 patients affected with cerebrotendinous xanthomatosis are Sephardic Jews of Moroccan extraction, probably dealing with an ethnic subgroup with a high CTX gene frequency, which is estimated to be 1/108.
Abstract: We described 6 patients (from 3 families) affected with cerebrotendinous xanthomatosis (CTX). All are Sephardic Jews of Moroccan extraction. In view of the small number of CTX patients diagnosed in the world (a total of 50 including our 6 patients), we are probably dealing with an ethnic subgroup with a high CTX gene frequency, which we have estimated to be 1/108. Since there are differences in expression in this disease, we recommend cholestanol study in cases of undiagnosed cataract or tendinous xanthomas in childhood or early adolescence. The diagnosis in CTX is important not only for genetic counseling, but also in veiw of possible treatment.
TL;DR: In this paper, it was shown that the in-plane shear modulus and Poisson's ratio of paper can be predicted with reasonable accuracy if the Young's moduli of the paper in the machine and cross directions are known.
TL;DR: The present tutorial describes an approach to interpreting a ‘3-view’ drawing for the construction of its ‘ 3-D’ representation.
TL;DR: In this article, the relationship between large-scale transient wave disturbances at the 200 mb level and the associated cloud field is studied in the latitude belt 20°S to 40°N based on wind and satellite-measured brightness data for the period June-August 1967.
Abstract: The relationship between the large-scale transient wave disturbances at the 200 mb level and the associated cloud field is studied in the latitude belt 20°S to 40°N based on wind and satellite-measured brightness data for the period June–August 1967. Space-time cross-spectral analysis is used to examine the degree of association of the wind and cloud fields in the wavenumber-frequency domain. The total time variance of the brightness field has a well-defined maximum near 10°N corresponding to a belt of sea surface temperature maximum. The divergence and relative vorticity as well as the brightness have a pronounced spatial scale of zonal wavenumber s ≈ 10 at this latitude. The major component contributing to this scale is westward moving disturbances with a period ∼ 5 days. There is high coherence between the brightness and divergence fields at these scales. In addition, high coherence is found for s = 3–6 and a period ∼ 5 days of westward moving disturbances corresponding to the wavenumber and p...
TL;DR: In this paper, measurements of the square wave response over a 4.1 km near-field horizontal path were presented for different wavelength regions, and the authors confirmed the existence and wavelength dependence of the aerosol modulation transfer function predicted by R. F. Lutomirski.
Abstract: Measurements of square wave response over a 4.1-km near-field horizontal path are presented for different wavelength regions. Relatively high winds generate increased concentrations of soil-derived aerosols that noticeably dampen low-spatial-frequency IR response. At diurnal Cn minimums, when turbulence is not severe, even more severe dampening of higher-spatial-frequency IR response by these aerosols is observed also, thus confirming the existence and wavelength dependence of the aerosol modulation transfer function predicted by R. F. Lutomirski [ Appl. Opt.17, 3915 ( 1978)]. However, when such aerosols are of reduced concentration, best-quality imaging through the atmosphere is observed in the IR rather than in the visible. This model of the wavelength dependence of imaging through the atmosphere is thought to be independent of geographical location. Since the size distributions of soil-derived aerosols remain relatively constant up to altitudes of approximately 5 km, their effects should be quite relevant for vertical and diagonal imaging as well.
TL;DR: Treatment success was significantly affected by age of the woman, duration of infertility, socioeconomic state of the couple, and the husband's acceptance of the AID procedure.
TL;DR: Computer image processing is shown to be a promising tool for statistical evaluation of pitting corrosion of AISI 304L stainless steel in a solution of FeCl3 by computer image processing methods.
TL;DR: The diverse methods employed in treating burns throughout the history of mankind, the classification of burns, the complications and the therapeutic armamentarium are discussed to point out the course of evolution of and difficulties in treatingBurns.