Showing papers by "Technion – Israel Institute of Technology published in 1973"
TL;DR: In this paper, a simple fatigue failure criterion for unidirectionally fiber reinforced laminae under oscillatory states of combined plane stress has been presented, expressed in terms of thre
Abstract: A simple fatigue failure criterion for unidirectionally fiber reinforced laminae under oscillatory states of combined plane stress has been es tablished The criterion is expressed in terms of thre
1,406 citations
TL;DR: In this paper, the authors studied more general iteration processes in certain Banach spaces with the purpose of extending this theorem and showed that sometimes their aim can indeed be (partially) achieved (see, for example, Theorem 2.10).
246 citations
148 citations
TL;DR: The bi-metric theory of gravitation proposed previously is simplified in that the auxiliary conditions are discarded, the two metric tensors being tied together only by means of the boundary conditions as mentioned in this paper.
Abstract: The bi-metric theory of gravitation proposed previously is simplified in that the auxiliary conditions are discarded, the two metric tensors being tied together only by means of the boundary conditions. Some of the properties of the field of a particle are investigated; there is no black hole, and it appears that no gravitational collapse can take place. Although the proposed theory and general relativity are at present observationally indistinguishable, some differences are pointed out which may some day be susceptible of observation. An alternative bimetric theory is considered which gives for the precession of the perihelion 5/6 of the value given by general relativity; it seems less satisfactory than the present theory from the aesthetic point of view.
115 citations
TL;DR: In this article, exact solutions for the quasi steady-state creeping flow internal and external to two spherical droplets moving along their line-of-centers are derived, which include all previous solutions as special cases.
110 citations
TL;DR: A heuristic algorithm for the general solution of large single-model assembly line balancing problems based on the optimum-seeking backtracking method proposed by Mansoor (1964), with excellent results from tests taken over a wide range of large ALB problems.
Abstract: This paper is concerned with the development of a heuristic algorithm (MALB) for the general solution of large single-model assembly line balancing problems. It is based on the optimum-seeking backtracking method proposed by Mansoor (1964). Excellent results were obtained from tests taken over a wide range of large ALB problems. Over a third of the tests yielded a 100% line efficiency and the overall computation time was 22 sec on an IBM 7040/7044.
107 citations
TL;DR: In this paper, a closed queuing network with a fixed number of jobs is considered and an approximate model for the open system where the computer is fed by randomly arriving jobs is developed.
Abstract: In a multiprogramming computer system several jobs may be handled simultaneously by utilizing the central processing unit in processing one job while other jobs are being served by the peripheral devices. Our analysis of such a computer system proceeds in the following way. First we view the system as a closed queuing network with a fixed number of jobs, and obtain exact results for customer cycle times and server utilization. Then we use these results to develop an approximate model for the open system where the computer is fed by randomly arriving jobs. For the approximate model we obtain simple closed-form expressions for the delay distribution. The approximate model is then tested by comparing its result for the expected sojourn time to the exact results that we obtain for some special cases.
97 citations
TL;DR: It is shown that the rate-distortion bound (R(d) \leq C) remains true when -\log x in the definition of mutual information is replaced by an arbitrary concave nonincreasing function satisfying some technical conditions.
Abstract: It is shown that the rate-distortion bound (R(d) \leq C) remains true when -\log x in the definition of mutual information is replaced by an arbitrary concave (\cup) nonincreasing function satisfying some technical conditions. Examples are given showing that for certain choices of the concave functions, the bounds obtained are better than the classical rate-distortion bounds.
93 citations
TL;DR: In this paper, a revised version of the "mesh step" model for the effect of a net type turbulence promoter on mass transfer in a narrow channel is presented, and the model is shown to yield a constant average boundary layer thickness the value of which is inversely proportional to the square root of the Peclet number.
92 citations
TL;DR: In this paper, the problem of heat transfer to an attached falling film has been investigated and solved numerically with a digital computer for five cases of boundary conditions, and the original problem which has three independent variables, two in space and one in time, is reduced by a similarity transformation to a two dimensional parabolic problem.
88 citations
TL;DR: Two multi-dimensional location problems, one involving location of supply sources for several commodities and the second a multistage distribution system in which the location of demand varies from stage to stage are analysed.
Abstract: A solution to the simple location problem is defined by a one-dimensional array of bivalent variables. Some multi-dimensional location problems may be also of interest in practice. Two such problems are analysed here. The first involves location of supply sources for several commodities and the second a multistage distribution system in which the location of demand varies from stage to stage. Examples of application from civil engineering practice are also presented.
TL;DR: The effect of two anticaking agents, calcium stearate and aluminium silicate, on the physical characteristics of powdered sugar was studied in this paper, where the authors used the Jenike Flow Factor Tester to evaluate the cohesiveness of these powders.
TL;DR: In this article, the phonon spectra of GaSe, GaS, and their solid solutions are presented, and a detailed study of the phonons in the two GaSe $A$ doublets is presented.
Abstract: The $\stackrel{\ensuremath{\rightarrow}}{\mathrm{k}}\ensuremath{\approx}0$ phonon spectra of the layer crystals GaSe, GaS, and their solid solutions are presented. All phonon bands in GaSe (${D}_{3h}$ symmetry) and GaS (${D}_{6h}$ symmetry) are assigned and good agreement prevails between experimental results and group-theory predictions. It is shown that GaSe behaves approximately like a two-dimensional crystal; judging by the display of its phonons the interaction between layers given rise to Davydov doublets. It is demonstrated that these splittings in GaSe may be accurately measured. Owing to lack of inversion symmetry both components of some of the doublets are Raman active, and thus the splitting is yielded directly by a single Raman experiment. The largest splitting was found to be about 7 ${\mathrm{cm}}^{\ensuremath{-}1}$. A correspondence between GaSe doublets and GaS single Raman bands is proven. A detailed study of $\stackrel{\ensuremath{\rightarrow}}{\mathrm{k}}\ensuremath{\approx}0$ phonons in $\mathrm{Ga}{\mathrm{Se}}_{x}{\mathrm{S}}_{1\ensuremath{-}x}$ solid solutions is presented. It shows that these solid solutions yield an exceptional behavior of the phonon modes; some of the bands are of the one-mode type, while the other are of the two-mode type. In the two GaSe $A$ doublets, mode coupling between the two conjugate lines occurs, and both repulsion and intensity transfer are revealed and discussed.
TL;DR: In this paper, an analytic formulation for the total potential in atomic and molecular systems, based on the electrostatic approach from the Hellmann-Feynman theorem, is given.
TL;DR: The aldolase of young adult and senescent mice was compared and deemed to be identical by various biochemical and physical parameters and the biological significance of these results is discussed.
TL;DR: In this paper, the effect of various types of structural modification on the critical micelle concentrations (CMC) and hydrophile-lipophile balances (HLB) of certain surfactants has been considered.
TL;DR: In this article, it was shown that the radiation-reaction concept, which explains classical radiative effects, cannot be used exclusively to explain atomic radiative effect, and must be supplemented by consideration of the vacuum field.
Abstract: It is shown that the radiation-reaction concept, which explains classical radiative effects, cannot be used exclusively to explain atomic radiative effects, and must be supplemented by consideration of the vacuum field.
TL;DR: Growth functions of informationless Lindenmayer systems are investigated from the point of view of integral sequential word functions and some of the inclusion relations between language families do not remain valid for the corresponding families of growth functions.
Abstract: Growth functions of informationless Lindenmayer systems are investigated from the point of view of integral sequential word functions. Algorithms are obtained for the solution of equivalence, minimization and construction problems. It is found out that some of the inclusion relations between language families do not remain valid for the corresponding families of growth functions. Some results concerning context-dependent Lindenmayer systems, as well as growth relations of OL-systems are also obtained.
TL;DR: Only few products from infectious organisms have been reported to induce high lymphocyte transformation, and it has been shown that a heat-stable lipopolysaccharide extract obtained from Escherichia coil will induce a transformation of B lymphocytes in the mouse.
Abstract: THERE are several agents known to be capable of inducing blast transformation of small lymphocytes. The mitogens phytohaemagglutinin (PHA), concanavalin A (con A) and pokeweed mitogen (PWM) are good examples of such agents1. The mitogenic activity of these agents is generally considered to be ‘non-specific’ since they transform a high proportion of lymphocytes taken from normal unimmunised animals2. In spite of extensive study, the immunological significance of lymphocyte transformation by mitogens is not yet clearly understood. It is possible that blast cells of a similar nature function, in the case of infection, as a defence against intracellular organisms3. It is therefore surprising that only few products from infectious organisms have been reported to induce high lymphocyte transformation. Ling and Husband4 transformed lymphocyte with a staphylococcus filtrate and Hirschhorn et at.5 obtained a similar effect using streptolysin-S. Recently it has been shown that a heat-stable lipopolysaccharide extract obtained from Escherichia coil will induce a transformation of B lymphocytes in the mouse6, 7.
TL;DR: In this paper, the active primary slip system was found to be the prismatic a type slip {1¯100} 〈11¯20〉 while the secondary system is either prismatic or pyramidal type I {10¯11}.
Abstract: The factors determining the active slip systems in cold-rolled polycrystalline titanium sheet were investigated. The texture of such a sheet has an important role in determining the active slip systems. Equi-Schmid factor lines for different slip modes were calculated, and transmission electron microscopy proved that pile ups of dislocations of the predicted systems are formed. The active primary slip system was found to be the prismatic a type slip {1¯100} 〈11¯20〉 while the secondary system is either prismatic or pyramidal type I {10¯11}. Basal slip of a dislocations could in certain orientations of load direction be the primary slip systems. Dislocations of the (c + a) type play no significant role in the plastic deformation of polycrystalline titanium sheet.
TL;DR: In this article, the pressure dependence of the Raman lattice modes of anthracene and naphthalene molecular crystals has been studied in the range 0-10 kbar, using hydrostatic pressure and laser excitation.
TL;DR: In this paper, a high-pressure 3He proportional counter with good energy resolution for fast neutrons has been developed with detailed descriptions of its construction and calibration and the determinat...
Abstract: A high-pressure 3He proportional counter has been developed with good energy resolution for fast neutrons, and detailed descriptions are given of its construction and calibration and the determinat...
TL;DR: In this paper, the drift mobility of excess holes was investigated in undoped NiO crystals using a transient technique with electron-beam excitation and the results lead to a phonon energy of 0.055 eV, a polaron effective mass of $1.5{m}_{0}$, and a coupling constant of 1.6.
Abstract: The drift mobility of excess holes has been investigated in undoped NiO crystals using a transient technique with electron-beam excitation. Specimens with low-impurity content were grown epitaxially from the gas phase. At room temperature ${\ensuremath{\mu}}_{h}$ lies between 20 and 50 ${\mathrm{cm}}^{2}$ ${\mathrm{V}}^{\ensuremath{-}1}$ ${\mathrm{sec}}^{\ensuremath{-}1}$, and its temperature dependence shows that scattering by optical modes predominates. The results lead to a phonon energy of 0.055 eV, a polaron effective mass of $1.5{m}_{0}$, and a coupling constant of 1.6.
TL;DR: A procedure by which the optimal design can be obtained has been developed and has been applied to small sewerage networks, both hypothetical and real, where its usefulness was clearly demonstrated.
Abstract: The cost of sewerage systems constitute a major fraction of the overall cost of wastewater disposal. Optimal design of such systems can be approached by employing dynamic programming. A procedure by which the optimal design can be obtained has been developed. This procedure is not practical at the present time due to limitations in computer space and computation time. An alternative, more restrictive, procedure has been proposed by which a suboptimal design can be obtained at a reasonable computation effort. This optimization procedure has been applied to small sewerage networks, both hypothetical and real, where its usefulness was clearly demonstrated. Large sewerage systems may be decomposed to small subsystems, which are optimized internally, and later recombined to a single optimal network. Development of more advanced computers may render the procedure applicable for obtaining the absolute optimal design of large networks.
TL;DR: In this article, the speed of the front of a suddenly switched on, submerged laminar jet in the Reynolds number range 80 < Re < 500 was investigated. And the experimental data were well correlated by an approximate model of the jet-vortex interaction in which the vortex is treated as a liquid drop with averaged properties.
Abstract: Experimental results are presented for the speed of travel of the spherical vortex at the front of a suddenly switched on, submerged, laminar jet in the Reynolds number range 80 < Re < 500. The results show that the speed of advance of the front is approximately one half of the speed of a fluid element on the axis of the steady jet. The experimental data are well correlated by an approximate model of the jet–vortex interaction in which the vortex is treated as a liquid drop with averaged properties. An auxiliary result is a new correlation for the axial variation of the velocity of a steady jet.