Showing papers by "École Polytechnique Fédérale de Lausanne published in 1970"
109 citations
31 citations
TL;DR: Scanning electron microscopic studies have revealed the configurations of the growth surfaces of scleractinian coral exoskeletons, suggesting that these scars are sites of attachment for the specialized processes that connect the living tissues of polyps to the nonliving skeleton.
Abstract: Scanning electron microscopic studies have revealed the configurations of the growth surfaces of scleractinian coral exoskeletons. Skeletal surfaces exhibit profuse growths of minute elongate aragonite crystals which, on basal and mural surfaces, are punctuated by scars. It is suggested that these scars are sites of attachment for the specialized processes that connect the living tissues of polyps to the nonliving skeleton. Patterns formed by the attachment scars are taxonomically significant.
25 citations
TL;DR: In this paper, a comparison of euchromatin and heterochromatin in the root tip of Rhoeo discolor was made microscopically by means of fluorescence, absorption, interference and volume measurements.
25 citations
TL;DR: A chick reared on glass over the deep side of a “visual cliff” loses its innate aversion to theDeep side if it is reared with one eye occluded, however, the induced loss of preference for the shallow side is not transferable to the other eye.
Abstract: A chick reared on glass over the deep side of a “visual cliff” loses its innate aversion to the deep side. If it is reared with one eye occluded, however, the induced loss of preference for the shallow side is not transferable to the other eye.
24 citations
TL;DR: A general formulation of discrete deterministic dynamic programming is given, obtained formally by derivation of a simplified algorithm from a general algorithm, and gives simultaneously the class of concurrent problems.
Abstract: A general formulation of discrete deterministic dynamic programming is given. This definition is obtained formally by derivation of a simplified algorithm from a general algorithm, and gives simultaneously the class of concurrent problems.
15 citations
TL;DR: In this paper, the authors dealt with solving two-dimensional variational problems of second-and third-order by the finite element method, where each meshpoint is associated with three or six basic functions of class C1 or C2.
Abstract: This paper deals with solving two-dimensional variational problems of second- and third-order by the finite element method. To each meshpoint are associated three or six basic functions of class C1 or C2. The expression of the admissible functions on a triangular and rectangular element are given here in a general form which is specially suitable for computation.
15 citations
TL;DR: In this article, the appearance of libration and non-Devonshire lines is explained by means of a simple 2-dimensional potential, which takes into account the coupling between translational and librational motion of the ions.
10 citations
TL;DR: In this paper, the ESR spectrum at room temperature and the absorption spectrum at 77°K of the pentachlorocyclopentadienyl radical C5Cl5 are reported.
8 citations
TL;DR: In this article, the parameters of polyphase transmission lines consisting of two or three equal parallel rectangular conductors are calculated for low and high frequencies, and the coefficients of resistance and internal inductance per unit length are given for the even and odd modes of two-conductor transmission lines.
Abstract: The parameters of polyphase transmission lines consisting of two or three equal parallel rectangular conductors are calculated for low and high frequencies An analog RC network with about 3300 nodes has been built which allows the diffusion equation and Laplace's equation in an infinite plane to be solved, and which lends itself favorably to the method of virtual displacement, too From measurements on this network, the coefficients of resistance and internal inductance per unit length are given for the even and odd modes of two-conductor transmission lines and for Clarke's ?-s-0 components of three-conductor transmission lines The results can be used to calculate the influence of proximity effect on resistive and inductive losses in busbar systems and cables with rectangular conductors carrying arbitrary phase currents Besides these results, methods are indicated to determine the capacitance per unit length, the electric and magnetic fields, and the magnetic forces between current-carrying conductors by means of the analog network It is believed that the method for direct measurement of serial losses and the curves in Figs 4?10 for the proximity effect of rectangular conductors are new
7 citations
TL;DR: In this paper, the Coulomb-Anteil der Gitterenergie von α-Al2O3 numerisch berechnet and eine Gitterkonstante of 7,883 A (25°25) fur the ungeordnete spinellartige γ-Al 2O3 Struktur aus thermodynamischen data is abgeleitet.
Abstract: Basierend auf bekannten thermodynamischen Daten von α-Al2O3 (Korund) und der Phasenumwandlung α-Al2O3 γ-Al2O3 werden eine Reihe von Konsequenzen fur die Natur der γ-Phase diskutiert. Es wird gezeigt, dass die Annahme einer unterkuhlten Flussigkeit fur die γ-Phase mit zuverlassigen Daten schwer vertraglich ist. Andererseits sind diese Daten konsistent mit einer ungeordneten kubischen Struktur der γ-Phase, die fur alle Temperaturen bis zum Schmelzpunkt des α-Al2O3 in Bezug auf dieses als thermodynamisch unstabil betrachtet werden kann. Die bisher bekannten Daten der Phasenumwandlung γα weisen insgesamt auf einen kinetisch kontrollierten Prozess hin, obwohl sie wechselseitig nicht konsistent sind. Es wird der Coulomb-Anteil der Gitterenergie von-γ-al2O3 numerisch berechnet und eine Gitterkonstante von 7,883 A (25°25) fur die ungeordnete spinellartige γ-Al2O3 Struktur aus thermodynamischen Daten abgeleitet.
TL;DR: This correspondence describes a way to compare binary with ternary logic and shows how the former can be compared with other types of logic.
Abstract: This correspondence describes a way to compare binary with ternary logic.
TL;DR: In this paper, an external modulation of a c.w. injection laser is described which allows a strong reduction of the excess noise of the laser beam, using KDP as a modulator and the modulating voltage was proportional to the noise voltage across the load resistor of the photodetector of the beam opposite the modulated one.
Abstract: An external modulation of a c.w. injection laser is described which allows a strong reduction of the excess noise of the laser beam. KDP was used as a modulator and the modulating voltage was proportional to the noise voltage across the load resistor of the photodetector of the beam opposite the modulated one.
TL;DR: In this article, p-trimethylsilyl benzoate was prepared by vinyl interchange and their structures were established by NMR, showing relatively high glass transition temperatures.
Abstract: Vinyl p-trimethylsilyl benzoate and vinyl m-trimethylsilyl benzoate were prepared by vinyl interchange and their structures were established by NMR. Vinyl o-trimethylsilyl benzoate could not be prepared by this method since it polymerized in situ to oligomers. 1.1-Di(o-trimethylsilyl benzoxy) ethane and l-acetoxy-1-o-trimethylsilyl benzoxy ethane were isolated as by-products of this reaction. The monomers underwent a rapid polymerization reaction when initiated with AIBN leading to glass clear polymers. The polymers showed relatively high glass transition temperatures. Their intrinsic viscosities were measured and the HUGGINS constants reported.
TL;DR: In this article, the authors present a mathematical model that describes temperature distribution in a body via heat conduction, which is the exchange of heat from regions of higher temperatures into regions with lower temperatures.
Abstract: Our aim is to construct a mathematical model that describes temperature distribution in a body via heat conduction. There are other forms of heat transfer such as convection and radiation that will not be considered here. Basically, heat conduction in a body is the exchange of heat from regions of higher temperatures into regions with lower temperatures. This exchange is done by a transfer of kinetic energy through molecular or atomic vibrations. The transfer does not occur at the same rate for all materials. The rate of transfer is high for some materials and low for others. This thermal diffusivity depends mainly on the atomic structure of the material. To interpret this mathematically, we first need to recall the notion of flux (that you might have seen in multivariable calculus). Suppose that a certain physical quantity Q flows in a certain region of the 3-dimensional space R. For example Q could represent a mass (think of flowing water), or could represent energy (think of heat), or an electric charge. The flux corresponding to Q is a vector-valued function q⃗ whose direction indicates the direction of flow of Q and whose magnitude |q⃗| the rate of change of Q per unit of area per unit of time. If for example Q measures gallons of water, then the units for the flux could be gallons per meter per minute. One way to understand the relationship between Q and q⃗ is a as follows. Let m0 = (x0, y0, z0) be a point in R with the standard canonical basis of orthonormal vectors i⃗, j⃗, k⃗. Consider a small rectangular surface S1 centered at m0 and parallel to the yz-plane. So the unit vector i⃗ is normal to S1. Assume that S1 has side lengths ∆z and ∆y (see Figure 1.)
TL;DR: In this article, a design for a UHV capacitive voltage divider for outdoor use, suitable for full-wave and switching-surge impulse voltage measurements, is described.
Abstract: A design for a UHV capacitive voltage divider for outdoor use, suitable for full-wave and switching-surge impulse voltage measurements, is described. Model studies, mechanical features and design of the low-voltage arm of the divider are examined. A calibration procedure is outlined, and the results of this are given. Results of tests under working conditions show that a satisfactory design has been achieved, giving a very short rise time and a high, voltage ratioaccuracy.
TL;DR: In this article, the noise figure as a function of the reflection coefficient of the source and of the collector current has been measured and the four fundamental noise parameters in the frequency range 4-8 GHz have been determined.
Abstract: The noise figure as a function of the reflection coefficient of the source and of the collector current has been measured. The four fundamental noise parameters in the frequency range 4--8 GHz have been determined.
TL;DR: In this paper, the capacitances of interconnecting coaxial cables and the self inductances of these common lines of a digital system are used to estimate the voltage fluctuations generated on the common supply and earth lines of the digital system.
Abstract: Voltage fluctuations generated on the common supply and earth lines of a digital system are caused mainly by capacitances of interconnecting coaxial cables and the self inductances of these common lines. This impairment of noise immunity can be eliminated by the addition of proper integrated m.o.s. capacitances.
TL;DR: In this paper, the regularization of the free plane motion is introduced showing the role of time repolarization for the rendezvous problem, and the general KS transormation is described and applied for solving this problem.
TL;DR: In this article, conditions of growth and properties of single crystals of orthorhombic (α)-sulfur from carbondisulfide solutions containing ad-mixture of organic compounds like benzene, cyclohexane, 1,3,5-trichlorobenzene, etc.