Showing papers by "École Polytechnique Fédérale de Lausanne published in 1971"
TL;DR: The results obtained suggest a subdivision of the archistriatum into 4 major regions: the anterior, intermedium, posterior (with a postero-ventral portion) and mediale, which give rise to descending pathways terminating in the medial and lateral hypothalamus, and may therefore be comparable to the mammalian amygdala.
436 citations
212 citations
TL;DR: The freeze-etching technique must be improved if structures at the molecular size level are to be seen and the 'double-replica' method allows one to evaluate such artefacts and provides an insight into the way that membranes split.
Abstract: The freeze-etching technique must be improved if structures at the molecular size level are to be seen. The limitations of the technique are discussed here together with the progress made in alleviating them. The vitrification of living specimens is limited by the fact that very high freezing rates are needed. The critical freezing rate can be lowered on the one hand by the introduction of antifreeze agents, on the other hand by the application of high hydrostatic pressure. The fracture process may cause structural distortions in the fracture face of the frozen specimen. The 'double-replica' method allows one to evaluate such artefacts and provides an insight into the way that membranes split. During etching there exists the danger of contaminating the fracture faces with condensable gases. Because of specimen temperatures below -110 $^\circ$ C, special care has to be taken in eliminating water vapour from the high vacuum. An improvement in coating freeze-etched specimens has resulted from the application of electron guns for evaporation of the highest melting-point metals. If heat transfer from gun to specimen is reduced to a minimum, Pt, Ir, Ta, W and C can be used for shadow casting. Best results are obtained with Pt-C and Ta-W. With the help of decoration effects Pt-C shadow castings give the most information about the fine structural details of the specimen.
196 citations
TL;DR: In this article, the rotational structure of several bands reveal a Coriolis type coupling between nearly degenerate a' and a'fundamentals, and strong Fermi resonances of combination tones involving the torsional mode with fundamentals are found for the gas spectra.
133 citations
TL;DR: In this paper, the Fourier transform of in-plane moving objects is used to measure the lateral displacement of the moving object and its time averaged and doubly exposed speckle patterns.
Abstract: Time averaged as well as doubly exposed speckle patterns of in-plane moving objects are studied. These speckle patterns are recorded photo-graphically; their Fourier transform shows, interference fringes corresponding to the lateral displacement of the object. It leads to a very simple engineering tool for the analysis of mechanical vibrations as well as lateral displacements. Theoretical and experimental results will be shown.
101 citations
TL;DR: The isolated adrenal cell technique provides measures of both affinity and “intrinsic activity”, information of some importance to the understanding of the relation of structure to biological action among members of a series of polypeptides related to ACTH.
77 citations
TL;DR: It is suggested that ACTH, 1--24 is a competitive antagonist of ACTH 1 _-39, and the observations of this report are in support of this suggestion.
64 citations
TL;DR: In this paper, an analysis of the rotational spectrum by rotation-internal rotation theory and by asymmetric rotor theory including centrifugal distortion in the Watson scheme is presented based on 76 newly measured microwave transitions of phenol in the torsional ground state.
52 citations
TL;DR: Pigeons pretrained on a VI and DRL schedule of reinforcement, respectively, sustained bilateral electrolytic or surgical lesions in the different regions of the archistriatum, and it is suggested that the somaticmotor archistsriatum inhibits monotonous pecking responses, and generates motivational approach responses, while the limbic archistRIatum rather inhibits approach responses and facilitates monotonously pecking responds.
47 citations
01 Jan 1971
TL;DR: In this article, the rotational capacity of reinforced concrete structures may be very small and as a result theoretical ultimate load can not be reached, and a considerable amount of experimental and theoretical research into the plastic behaviour of statically indeterminate structures has been carried out during the last 20 years.
Abstract: A considerable amount of experimental and theoretical research into the plastic behaviour of statically indeterminate structures has been carried out during the last 20 years. The application of the simple plastic analysis to steel structures has been shown to be valid. In statically indeterminate reinforced concrete structures, however, the rotational capacity of plastic hinges may be very small and as a result theoretical ultimate load can not be reached.
30 citations
TL;DR: The acidity constants of the deprotonated triaminocyclohexane have been determined with a rapid flow apparatus as mentioned in this paper, but it proved to be impossible to study the slow condensation to polynuclears quantitatively because of decomposition with production of ammonia.
TL;DR: In this article, the same chromophoric group (1-amino-4-anilino-anthraquinone-2- sulfonic acid) was used for dyeing wool.
Abstract: Wool was dyed with seven reactive dyes having the same chromophoric group (1-amino-4-anilino-anthraquinone-2- sulfonic acid) but different reactive groups and then thoroughly extracted so that all noncovalently bound dye was re moved. The wool was treated with buffer solutions in the pH range of 1.6-10.6 at 70°C. The hydrolysis rate of the dye-fiber bonds was estimated by colorimetric measurement of the buffer solution.Reactive dyes containing the α-bromoacrylamide or the difluoromonochloropyrimidyl system gave the highest fixation on wool, whereas those containing a mono- or di-chloro-s-triazine, trichloropyrimidine, or vinylsulfone group gave lower values. Poor fixation was obtained with the β-hydroxyethylsulfone sulfuric acid ester and the β-hydroxyethylsulfona mide reactive group. Since only 2-10% dye-fiber bond hydrolysis was observed after 24 hr at 70°C, it must be concluded that the dye-fiber bond stability of all the reactive groups now available is sufficient for wool dyeing. The washfastness of ...
TL;DR: In this article, it was shown by IR spectroscopy that hydrogen is incorporated in the structure of transition metal doped sapphire by H 2 at high temperature and its site is determined and depends on the transition metal ion.
TL;DR: In this article, the spectrum of knowledge on phase transitions in dielectric crystals has become very wide and diversified, and the nomenclature used so far is critically reviewed.
TL;DR: In this paper, a solution to the quantum mechanical rotation-inversion problem is given for semi-rigid molecules with one finite internal degree of freedom. But the solution is not complete.
Abstract: Molecules which consist of a rigid frame of C 2v symmetry and an invertor moving around an internal axis fixed in the frame may be considered as a specific case of semi-rigid molecules with one finite internal degree of freedom. Representative examples are ethylene imine, phosphirane, ammonia-d 1, cyanoamine. For this class of molecules the solution to the quantum mechanical rotation-inversion problem is given. Starting from the classical rotation-inversion hamiltonian, the symmetry group of the problem is shown to be isomorphous to O +(3) × V 4. The kinetic energy matrix is then calculated analytically in the direct product of the bases of the symmetric rotor and the trigonometric functions. The calculation of the matrix elements, though quite complicated, is possible in closed form by complex integration. This in turn leads to a new aspect of the problem, which consists in a discussion of the zeros of the kinetic determinant |g mn | = g. The roots of g lying within the unit circle in the complex plane a...
TL;DR: In this article, the influence of the parasitic package elements on gain and input admittance of three stripline packages belonging to three microwave bipolar transistors with fmax at approximately 10 GHz.
Abstract: Since it is important to know the influence of the parasitic package elements on gain and input admittance, the equivalent circuits of three stripline packages are given belonging to three microwave bipolar transistors with fmax at approximately 10 GHz.
TL;DR: A single array performing multiplication or division of two binary numbers is proposed, implemented with the new t.t.l. 4-bit integrated circuits.
Abstract: A single array performing multiplication or division of two binary numbers is proposed Implemented with the new ttl 4-bit integrated circuits, it performs these two operations on 16-bit numbers in 640 and 890 ns, respectively
TL;DR: The isotopic composition and concentration of He, Ne and Ar produced by cosmic rays were measured spectrometrically in bulk samples and in taenite and schreibersite phases of 4 iron meteorites.
TL;DR: In this article, the formation of an atom-radical complex [C 5 Br 5 …Br] in rigid solution is suggested by the behaviour of the absorption spectrum as a function of temperature.
TL;DR: In this article, the voltage-current characteristic of a fast electric discharge in a HeCO2 gas mixture was measured as a function of initial voltage, pulse energy, and CO2-content.
TL;DR: Schottky barriers have been prepared by sputter-etching a silicon surface immediately prior to the deposition, by sputtering, of an aluminium electrode as discussed by the authors, and the barrier height measured on these diodes is nearly identical to the height found previously for barriers made by cleaving silicon in a vacuum in a stream of evaporating aluminium species.
Abstract: Schottky barriers have been prepared by sputter-etching a silicon surface immediately prior to the deposition, by sputtering, of an aluminium electrode. The barrier height measured on these diodes is nearly identical to the height found previously for barriers made by cleaving silicon in a vacuum in a stream of evaporating aluminium species. This suggests that the barrier height is controlled by surface states.
TL;DR: In this article, a new mass spectrometer of the omegatron type has been designed and tested, which combines the extremely low permaent outgassing and pumping rates of the Omegatron (less than 10−11 torr liter/sec. respectively) with a high scanning rate (typically 10 spectra/sec.).
Abstract: A new mass spectrometer of the omegatron type has been designed and tested. This new device, which we have called the resotron, combines the extremely low permaent outgassing and pumping rates of the omegatron (less than 10−11 torr liter/sec. and 10−3 liter/sec. respectively) with a high scanning rate (typically 10 spectra/sec.) allowing the spectrum to be displayed on an oscilloscope. The sensitivity is about 10−12 torr of partial pressure and the resolving power (at 5% peak height) is about 40 at mass 40 forB=4000 Gauss, or 70 at mass 70 forB=12000 Gauss. In this paper, the performances of the omegatron and the resotron are compared. An original theory of the cyclotron resonance is developed. Based upon a circular motion approximation, this general treatment is applied to the case of the perturbation caused by the space charge of the beam, and for the conditions of rapid scanning over the resonance frequency. Experimental data are compared with the theoretical predictions. A brief description of the electronics is also given.
01 Jan 1971
TL;DR: In this paper, the theory of perturbed angular correlations of time independent interactions is formulated in such a way as to display explicitly the interference properties of the individual energy levels of the intermediate state.
Abstract: The theory of perturbed angular correlations of time — independent interactions is formulated in such a way as to display explicitly the interference properties of the individual energy levels of the intermediate state. In time — differential angular correlation experiments, interfering energy eigenstates give rise to oscillations whose period is a direct measure of the energy difference of the corresponding levels. Two energy levels that cross as a function of an external magnetic field may produce a resonance in a time — integrated angular correlation experiment, because of interference between the two states. From general symmetry properties of the extranuclear interactions, a number of selection rules for interference is derived. Based on these rules and the level structure of the intermediate system in the extranuclear field, general properties of the angular correlation function can be derived without calculation. The method is illustrated by discussing hitherto unobserved effects in angular correlations due to the hyperfine interaction in free atoms and in paramagnetic crystals. Characteristic effects produced by the mixing of states in the vicinity of repulsive energy levels are also discussed.
TL;DR: Drosophila-melanogaster-Weibchen, genetisch markiert mit scarlet, Kinked, Ki and pink peach wurden bestrahlt, um Compound-3-Chromosomen herzustellen, zeigt, dass das Zentromer links der Markierung Kinking liegt.
Abstract: HomozygoteDrosophila-melanogaster-Weibchen, genetisch markiert mit scarlet (st), Kinked (Ki) und pink peach (Pp) wurden bestrahlt, um Compound-3-Chromosomen herzustellen. Es wurden ausschliesslich st/st- und Pp Ki/Ki(?) Pp-Compoundchromosomen gefunden. Dies zeigt, dass das Zentromer links der Markierung Kinked liegt.
TL;DR: In this article, an IR-TV-microscope was used to develop AgBr-Emulsions under monitor-control in an electron microscope, and it was shown that the filaments produced initially do not consist of silver, but of AgBr or some complex.
Abstract: AgBr-Emulsions were developed under monitor-control in an IR-TV-microscope. Electron-microscope observation shows, that the filaments produced initially do not consist of silver, but of AgBr or some complex. The part of the filament closest to the grain gets reduced to silver only towards the end of development. The filaments often appear branched and are stable in the electron microscope under normal conditions of use. The findings support those reported by Mueller.
TL;DR: Using a monodisperse liquid emulsion, uniform exposure, locus-and orientation independent development and controlled bleaching treatment in order to detect the onset of development, the induction of chemical photographic development was studied.
Abstract: Using a monodisperse liquid emulsion, uniform exposure, locus- and orientation independent development and controlled bleaching treatment in order to detect the onset of development, the induction of chemical photographic development was studied. An induction period, as defined in this work, could not be detected for times as short os 1/1000 that required for complete development.
01 Jan 1971
TL;DR: In this article, the shape of the resonance signal in the usual geometry (magnetic field perpendicular to the detector plane) depends strongly on the angle Φ between the two γ rays.
Abstract: Resonances in perturbed angular correlations due to crossing hyperfine levels have, so far, been observed on two cascade transitions, the 172 – 203 keV cascade1) in 127I and the 55 – 188 keV cascade2) in 125I. According to the theory3) the shape of the resonance signal in the usual geometry (magnetic field perpendicular to the detector plane) depends strongly on the angle Φ between the two γ rays. In particular at angles Φ = 5π/4, 3π/4 a pure dispersive shape is expected.