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Showing papers by "University of Ljubljana published in 1975"


Journal ArticleDOI
20 Mar 1975-Nature
TL;DR: An approximately molar ratio for these elements in certain human organs following exposure to high levels of inorganic mercury is reported.
Abstract: THE ability of selenium compounds to modify profoundly the toxicity of both organic and inorganic mercury compounds has been demonstrated in experimental animals by Parizek and co-workers1,2. The analytical data of Ganther et al.3 on tuna and of Koeman et al.4 on marine mammals showed that natural levels of mercury and selenium are strongly correlated. Here we report an approximately molar ratio for these elements in certain human organs following exposure to high levels of inorganic mercury.

294 citations


Journal ArticleDOI
TL;DR: In this article, high density samples (97% TD) were prepared by conventional sintering technique and Mg-doped sintered samples exhibit increase in k p, some lowering in e and large increase in resistivity after prolonged sinter.

174 citations


Journal ArticleDOI
A. Levstik1, Robert Blinc1, P. Kadaba1, S. Čižikov1, I. Levstik1, C. Filipič1 
TL;DR: In this article, the authors show that orthorhombic CsH 2 PO 4 undergoes a ferroelectric transition at T c = −119.5° C, whereas the ferroelectric transition temperature in isomorphous CsD 2 PO4 is Tc = −5.55° C.

79 citations


Journal ArticleDOI
TL;DR: In this article, a variational method for density matrices is adapted for applications in light nuclei, where the energy E = ∑ H ijklϱijkl is minimized using the two-body density matrix elements ϳijkl = 〈 Ψ ‖ a j + a i + a k a l ‖ Ψ 〉 as variational parameters.

66 citations


Journal ArticleDOI
TL;DR: The changes in the end-plate current, observed at a relatively high concentration of reversible inhibitors, are thought to be related either to a presynaptic, or to a postsynaptic “curare-like” action of these drugs.

60 citations


Journal ArticleDOI
TL;DR: A new sulphydryl acid protease has been isolated from calf lymph nodes and hydrolysis was optimal at pH 3.0 and it was not inhibited by pepstatin.

54 citations


Journal ArticleDOI
TL;DR: Granule and post-granular-supernatant fractions were obtained from pig leucocyte cells by differential centrifugation in 0.34 M sucrose and the acid proteinase activity towards hemoglobin and casein and non-stable neutral proteolytic activity towards bovine serum albumin and serum gamma globulin was found.
Abstract: Granule and post-granular-supernatant fractions were obtained from pig leucocyte cells by differential centrifugation in 034 M sucrose Granule extract possesses proteinase activity at acid and at neutral pH Three groups of neutral and a group of acid proteinases were isolated from granule extracts by chromatography on DEAE-cellulose In the first group are present elastase-like and plasminogen-activator proteinases, that are inhibited by diisopropylphosphorofluoridate, alpha1-antitrypsin, intracellular leucocyte inhibitor and partly with p-aminomethylbenzoic acid and Trasylol The second group of neutral proteinases is unstable under the conditions of isolation used the third group of neutral proteinases comprises collagenases that are inhibited by ethylenediamine tetraacetic acid disodium salt, alpha1-antitrypsin and leucocyte inhibitor The acid proteinases are inhibited only with pepstatin, up to 90% In the post-granular supernatant was found the acid proteinase activity towards hemoglobin and casein, and non-stable neutral proteolytic activity towards bovine serum albumin and serum gamma globulin In the post-granular supernatant also the inhibitors of neutral proteinases were found By gel filtration on Sephadex G-100 and ion-exchange chromatography on CM-cellulose two inhibitors of neutral proteinases were isolated The majority of the inhibitor capacity (about 80%) of post-granular supernatant was eluted together with ovalbumin (Mr 43000) and the remainder with cytochrome c (12300) These inhibitors inhibit the granule neutral proteinases, acting on all substrates used, but do not inhibit granule acid proteinase Inhibition effects of post-granular-supernatant inhibitors on trypsin and chymotrypsin were obtained only when bovine serum albumin was used as substrate Inhibitors of post-granular supernatant are stable at pH 6-8, but unstable in the pH rnage 2-5 and are thermolabile

47 citations


Journal ArticleDOI
TL;DR: In this article, all electron energy band structure was reported for an infinite one-dimensional model of polysulfur nitride, (SN) x, using the ab initio LCAO Hartree-Fock method.

38 citations


Journal ArticleDOI
TL;DR: In this article, the authors discuss the computational problem encountered in making direct variational calculations of the reduced density matrices of many-particle systems, and two different algorithms are presented for which working programs have been written.

36 citations


Journal ArticleDOI
TL;DR: In this article, the origin of the multiple OH(D) bands in the region 1900-3000 cm−1 is discussed, and the polarised spectra of single crystals of the title compound and its O-deuterated analog are assigned.

32 citations


Journal ArticleDOI
TL;DR: The variables necessary for gait evaluation are defined and two quantitative methods for their interpretation are given and the results show the applicability of the described techniques of evaluation.
Abstract: Although the functional electrical stimulation orthosis is one of the most recent approaches to the rehabilitation of hemiplegic patients, the quantitative estimate of its influence on the patients walking is not satisfactorily solved. In this communication the variables necessary for gait evaluation are defined and two quantitative methods for their interpretation are given. The second method was tested on eight hemiplegic patients. The results show the applicability of the described techniques of evaluation.

Journal ArticleDOI
TL;DR: In this paper, the frequency and temperature dependences of the proton T1 in nematic MBBA have been investigated, and the results have been compared with the predictions of the order fluctuation and self-diffusion relaxation theories.

Journal ArticleDOI
TL;DR: In this article, the direction of dipole orientation and the structure assigned to the adducts were elucidated by nm-r spectroscopy, and the results of synthesis agreement with previously reported mechanistic considerations.

Journal ArticleDOI
TL;DR: In this paper, the partial molar volumes and viscosity B coefficients of tri-n-dodecyl, tri n-decyl-, tri ndecyl, Tri n-hexyl- and tri nhexyl amines in benzene solutions at 25°C have been determined.

Book ChapterDOI
TL;DR: In this paper, the authors proposed a high sensitivity technique which detects the weak NMR or NQR signal of type B nuclei via their effect on the A spin system which exhibits a strong NMR signal.
Abstract: Nuclear double resonance as introduced by Hartmann and Hahn [1] and later by Lurie and Slichter [2] is a high sensitivity technique which detects the weak NMR or NQR signal of type B nuclei via their effect on the A spin system which exhibits a strong NMR signal. The technique is based on the existence of nuclear dipole-dipole coupling between the two spin systems in a frame of reference in which the energy levels of the A and B spins are equally spaced, which makes entropy transport possible.

Journal ArticleDOI
TL;DR: In this article, the kinetic and thermal parameters for the decomposition of a group of polymerization initiators were determined using differential scanning calorimetry (DSC), and they were made in the temperature range between 50°C and 180°C.
Abstract: The kinetic and thermal parameters for the decomposition of a group of polymerization initiators were determined using differential scanning calorimetry (DSC). The solvent was di-n-butylphthalate, and the measurements were made in the temperature range between 50°C and 180°C. The activation energies for azobisisobutyronitrile and benzoyl peroxide are 137.5 kJ/mol (32.9 kcal/mol) and 119.6 kJ/mol (28.6 kcal/mol), respectively, which is in agreement with literature values. The activation energies for technical lauroyl peroxide and technical methylethylketone peroxide are 141.7 kJ/mol (33.9 kcal/mol) and 181.4 kJ/mol (43.4 kcal/mol), respectively, and are higher than the values reported in the literature. This is probably due to the fact that technical samples were used. The heats of decomposition were also obtained. They are − 230.7 kJ/mol ( − 55.2 kcal/mol) for azobisisobutyronitrile, − 293.0 kJ/mol ( − 70.1 kcal/mol) for benzoyl peroxide, − 693.5 J/g ( − 165.9 cal/g) for lauroyl peroxide, and −459.8 J/g ( − 110.0 cal/g) for methylethylketone peroxide. Fur die Bestimmung kinetischer und thermischer Parameter beim Zerfall einiger Polymerisationsinitiatoren wurde die Differential-Scanning-Kalorimetrie (DSC) verwendet. Die Initiatoren wurden in Di-n-butylphthalat gelost. Die Messungen erfolgten im Temperaturbereich zwischen 50°C und 180°C. Die Aktivierungsenergien wurden fur Azobisisobutyronitril zu 137,5 kJ/mol (32,9 kcal/mol) und fur Benzoylperoxid zu 119,6 kJ/mol (28,6 kcal/mol) gefunden, was mit Literaturangaben ubereinstimmt. Die Aktivierungsenergie des technischen Lauroylperoxids und technischen Methyluthylketonperoxids betragt 141,7 kJ/mol (33,9 kcal/mol) bzw. 181,4 kJ/mol (43,4 kcal/mol). Diese zwei Werte sind hoher als die in der Literatur gefundenen, wahrscheinlich weil technische Produkte untersucht wurden. Es wurden auch die Zerfallswarmen der Initiatoren bestimmt. Sie betragen: −230,7 kJ/mol (−55,2 kcal/mol) fur Azobisisobutyronitril, −293,0 kJ/mol (−70,1 kcal/mol) fur Benzoylperoxid, −693,5 J/g (−165,9 cal/g) fur Lauroylperoxid und −459,8 J/g (−110,0 cal/g) fur Methylathylketonperoxid.



Journal ArticleDOI
TL;DR: In this article, the density profile at the crystal-liquid interface is calculated with the help of the Born-Green-Yvon-Bogolyubov integrodifferential equation.
Abstract: The density profile at the crystal-liquid interface is calculated with the help of the Born-Green-Yvon-Bogolyubov integrodifferential equation. It was found that meaningful solution can be obtained after adapting the temperature and replacing the crystalline bulk by a rigid wall.

Journal ArticleDOI
TL;DR: The pure nuclear quadrupole resonance spectra of 14N have been measured in trisarcosine calcium chloride (TSCC), deuterated TSCC, and sarcosine using nuclear double resonance in the laboratory frame as mentioned in this paper.
Abstract: The pure nuclear quadrupole resonance spectra of 14N have been measured in tris‐sarcosine calcium chloride (TSCC), deuterated TSCC, and sarcosine using nuclear double resonance in the laboratory frame. In TSCC two chemically nonequivalent nitrogen sites have been found at room temperature, one with a quadrupole coupling constant e2Qq/h =1040 kHz and an asymmetry parameter η=1 and another one with e2Qq/h = 940 kHz, η=1. The 14N results in deuterated TSCC differ from those in undeuterated TSCC by less than 10%. The corresponding 14N data for sarcosine are e2Qq/h = 1440 kHz, η=1 and e2Qq/h = 1470 kHz, η=0.79. In the ferroelectric phase at 77 °K only one nitrogen site has been found in TSCC with e2Qq/h = 1010 kHz and η=0.89. In TSCC, ν (35Cl) =2160 kHz and ν (37Cl) =1710 kHz, and deuterated TSCC 35Cl and 37Cl quadrupole resonance lines were found in the paraelectric phase, whereas in the ferroelectric phase no chlorine lines could be observed.

Journal ArticleDOI
TL;DR: In this paper, the orientation relationship between two adjacent martensite plates in a nearly stochastic NiMn alloy was investigated by electron microscopy and electron diffraction, and the predicted shape change and orientation relationship were found to be in good agreement with the experimental observations.
Abstract: The orientation relationship between two adjacent martensite plates in a nearly stoichiometric NiMn alloy which was quenched from the high temperature ordered CsCl phase (β) to the ordered tetragonal phase (θ) have been investigated by electron microscopy and electron diffraction. The Wechsler-Lieberman-Read phenomenological theory of martensite formation has been applied, and the predicted shape change and orientation relationship are found to be in good agreement with the experimental observations. It is shown that the interface between two adjacent plates coincides with the average over predicted undistorted planes in the plates. The self-accommodating nature of the product is discussed. Die Orientierungsbeziehungen zwischen zwei angrenzenden Martensitplatten in einer fast stochiometrischen NiMn-Legierung wurden mit Hilfe von Elektronenmikroskopie und Elektronenbeugung nach Abschrecken von der geordneten Hochtemperature β-Phase des CsCl-Typs in die geordnete tetragonale θ-Phase untersucht. Die phanomenologische Theorie der Martensitbildung von Wechsler, Lieberman und Read wurde angewandt und die vorhergesagten Gestaltsanderungen und Orientierungsbeziehungen wurden in guter Ubereinstimmung mit experimentellen Ergebnissen gefunden. Es wird gezeigt, das die Grenze zwischen zwei Martensitplatten den Mittelwert der beiden vorausgesagten unverzerrten Plattenebenen darstellt. Die sich selbst-anpassende Natur der Endstruktur wird disktutiert.

Journal ArticleDOI
TL;DR: In this article, the authors consider the existence of active dilatation as a physical realization of conformal transformations, which transform the rest masses of particles, such as nuclei, atoms, crystals, galaxies, etc.
Abstract: If we assume that scale is a degree of freedom which a physical object, such as a galaxy possesses besides translational and rotational degrees of freedom, we are able to incorporate such diverse phenomena as the systematic cosmological red-shifts, anomalous red-shifts, controversals of quasars, and the expansion of Earth into a single theory. At the same time we can consider the proposed existence of active dilatation as a physical realization of conformal transformations. Active conformal transformations transform the rest masses of particles. The objection that this implies a continuous rest mass spectrum which is not observed is avoided by assuming that particles can form bound systems such as nuclei, atoms, crystals, galaxies, etc., only if ‘discrete’ scale relations are established among the constituent particles. Different galaxies can be dilated relative to each other. (Note the analogy with ‘discrete’ positions of atoms in a crystal. Different crystals can be translated arbitrarily each to the other.) An observer in a contracting galaxy experiences that the universe is expanding.


Journal ArticleDOI
TL;DR: In this paper, the formation of heterocyclic thioamides from alkylpyridines, heteroaromatic amines and sulfur was investigated, and Oxidative cyclization of these thiosamides afforded the corresponding thiazoloazines.

Journal ArticleDOI
TL;DR: In this article, low-lying excited states are calculated within the particle-hole space using the previously introduced hermitian operator method using a variational approach to density matrices.

Journal ArticleDOI
TL;DR: In this paper, the course and kinetics of the curing of epoxy resins by acid anhydrides were studied by differential scanning calorimetry (DSC), and the reaction order and rate constants were evaluated.
Abstract: Course and kinetics of the curing of epoxy resins by acid anhydrides were studied by differential scanning calorimetry (DSC). The heat of reaction at 107.5°C was found to lie between −302.2to −333.2 J/g (−72.2 to −79.6 cal/g), depending on the composition of the reaction system. For one reaction system measurements were made at three different temperatures. From DSC data the reaction order and rate constants were evaluated. Between 18 to 80% conversion the curing reaction was found to be 0.5 order, and from 80 to 98% conversion to be first order. From the rate constants using the Arrhenius equation the activation energy was calculated. The values of the activation energy are 58.2 KJ/mol (13.9 kcal/mol) for 0.5 order and 56.1 KJ/mol (13.4 kcal/mol) for first order reaction. Unter Anwendung der Differential-Scanning-Calorimetrie (DSC) wurden der Verlauf und die Kinetik der Hartung von Epoxid-Harzen untersucht. Es wurde gefunden, das die Reaktionswarme bei 107,5°C, in Abhangigkeit von der Zusammensetzung des Reaktionssystems, zwischen −302,2 und −333,2 J/g (−72,2 bis −79,6 cal/g) betragt. Fur ein System wurden die Messungen bei drei verschiedenen Temperaturen durchgefuhrt. Aus den DSC-Kurven wurden die Reaktionsordnung und die Reaktionsgeschwindigkeitskonstanten bestimmt. Es wurde gefunden, das die Reaktion zwischen 18 und 80% Umsatz nach der Ordnung 0,5 und zwischen 80 und 98% Umsatz nach der ersten Ordnung verlauft. Aus den Geschwindigkeitskonstanten wurden nach der Arrheniusschen Gleichung die Aktivierungsenergien ausgerechnet, und zwar fur die 0,5te Ordnung 58,2 KJ/mol (13,9kcal/mol) und fur die erste Ordnung 56,1 KJ/mol(13,4kcal/mol).

Journal ArticleDOI
TL;DR: In this article, the authors describe the triboluminescence of rubber and demonstrate it by records of the intensity of emitted light and the variation of strain with stress of a rubber band.
Abstract: The author describes the triboluminescence of rubber and demonstrates it by records of the intensity of emitted light and the variation of strain with stress of a rubber band. The marked increase of the emission of light with onset of plastic deformation and the irreversibility of triboluminescence on repeated deformation suggest an analogy between triboluminescence and acoustic emission. These properties of triboluminescence, it is suggested, may be applied like sound emission in non-destructive testing.

Journal ArticleDOI
TL;DR: In this paper, the low-lying states of the nuclei 16 O and 20 Ne were calculated with the generator coordinate method and the agreement was better than 0.5 MeV for most lowlying states.

Journal ArticleDOI
TL;DR: A simple goniometric system intended for quantitative evaluation of a patients' gait is described, using a special knob to adjust and fix the knee potentiometer axis position, a small number of selectively chosen attachments and very light construction.
Abstract: A simple goniometric system intended for quantitative evaluation of a patients' gait is described. The hip, knee and ankle angles of both legs in the sagittal plane and the contacts between ground and three parts of the sole were measured. By using a special knob to adjust and fix the knee potentiometer axis position, a small number of selectively chosen attachments and very light construction, the gait was disturbed to the minimum extent. The system's accuracy was tested by comparing the directly measured step length and the calculated one. The accuracy achieved was better than 5%.

Journal ArticleDOI
TL;DR: In this article, it was shown that the set of Case's eigenfunctions of the one speed transport equation is complete in the rigged Hilbert space W 2 1 ([−1, 1])⊂L 2(− 1, 1)⊆W 2 −1 ([− 1, 1])
Abstract: It is shown that the set of Case's eigenfunctions of the one speed transport equation is complete in the rigged Hilbert spaceW 2 1 ([−1, 1])⊂L2(−1, 1)⊂W 2 −1 ([−1, 1]).