Showing papers by "University of Ljubljana published in 1969"
TL;DR: A new method based on complete ignition of the sample in a silica tube, trapping volatile interfering activities such as bromine or chlorine, and selectively adsorbing mercury on a strip of filter paper which has been previously impregnated with elemental selenium is devised.
66 citations
TL;DR: The spectrum of a neutron gas in a uniform moderator is confined to the real axis as mentioned in this paper, and it consists of the intervals (− ∞, − κ ∗ ] and [κ ∗, ∞], with no eigenvalues imbedded inside.
26 citations
TL;DR: In this paper, the ground state density matrix is expressed in terms of transition amplitudes, which are then used as ground state variational p parameters to bound the two-body density matrix.
25 citations
TL;DR: In this article, the total absorption of gamma rays in the energy region 9 − 31 MeV was measured in thick absorbers of carbon, nitrogen, oxygen and fluorine by means of a Compton spectrometer.
25 citations
TL;DR: In this article, it was shown that 6-azido-7methyltetrazolo[1·5-b]pyridazine isomerizes into the thermodynamically more stable 6-zidopyrido[2·3d]tetrazolopyride[5·1b]-pyridine by simultaneous ring opening of the tetrazolo ring and cyclization of the azido group.
21 citations
01 Sep 1969
TL;DR: In this paper, a two-level model for the paraelastic defect is adopted, and the coupling between the defect and the lattice vibrations is considered to be strong, and it is shown that the change of the elastic compliance due to the defects is in general a superposition of the Debye-type relaxation and of resonant absorption of the acoustic waves.
Abstract: The dynamical behavior of the elastic constants of a crystal containing paraelastic defects is investigated theoretically. A two-level model for the paraelastic defect is adopted, and the coupling between the defect and the lattice vibrations is considered to be strong. The imaginary part of the elastic compliance tensor is calculated by the Green's function method using the Feynman graph technique. It is shown that the change of the elastic compliance due to the defects is in general a superposition of the Debye-type relaxation and of resonant absorption of the acoustic waves. Expressions for the linewidth of the resonance and the Debye relaxation time are derived.
18 citations
TL;DR: Gamma-ray spectra from the radiative capture of 14.1 MeV neutrons in natural Mg, Si, P and Ca measured with a scintillation telescope pair spectrometer are presented in this article.
16 citations
TL;DR: In this paper, the Slovenian gypsies are a different ethnic group from the surrounding panmictic Slav population and on the basis of anthropological, linguistic, sociological and psychological characteristics their settlements can be characterized as isolates in the population genetics sense.
Abstract: Data are presented on the ethnological, demographic, reproductive, immunological and medical characteristics of the gypsy isolates in Slovenia. It is concluded that the Slovenian gypsies are a different ethnic group from the surrounding panmictic Slav population and on the basis of anthropological, linguistic, sociological and psychological characteristics their settlements can be characterized as isolates in the population genetics sense.
14 citations
TL;DR: Sterically unhindered s-triazolo[4,3-b] pyridazines form N1-methiodides, whereas 3-and/or 8-substituted analogs form a mixture of N1 and N2-mETHiodides.
13 citations
TL;DR: The correction time for proton motion in pure ice has been directly determined by measuring the frequency dependence of the rotating frame proton spin-lattice relaxation time T 1 ϱ as discussed by the authors.
12 citations
TL;DR: In this article, it was shown that the elements of the two-particle density matrix are severely restricted by homogeneous linear relations, and their full content is expressed in terms of an auxiliary one-person density which possesses additional positivity properties in the ground state.
Abstract: The following question is considered: What special properties are possessed by those reduced density matrices which come from energy eigenstates? Using the fact that 〈φ[H, A]|φ〉 = 0, where A is any operator and |φ〉 an energy eigenstate, it is shown that the elements of the two‐particle density matrix are severely restricted by homogeneous linear relations. Their full content is expressed in terms of an auxiliary one‐particle density which possesses additional positivity properties in the ground state.
TL;DR: In this paper, chemical and spectral analyses for 16 sphalerites from Yugoslavia were given for the wavelengths 440, 460, 480, 500, 540, 580, 620, and 660 nm.
Abstract: Chemical and spectral analyses are given for 16 sphalerites from Yugoslavia. Since they were formed under various conditions the content of Fe and other metals (Mn and Cd especially) varies widely. The relation between the dimensions of elementary cell and the molar percent of FeS in the sphalerites of Yugoslavia shows only slight differences from Vegard's rule. The indices of refraction and reflectivity as well as dispersion for the wavelengths 440, 460, 480, 500, 540, 580, 620, and 660 nm were measured. For the wavelengths mentioned, diagrams are given showing the relation between reflectivity and microhardness of sphalerite and its chemical composition.
TL;DR: In this paper, the authors give a compact and easily applicable criterion for the existence of a unique inverse of an important class of vector-valued functions, referred to as globally regular functions.
Abstract: In the analysis of nonlinear networks it is usually necessary to perform functional inversion. The letter gives a compact and easily applicable criterion for the existence of a unique inverse of an important class of vector-valued functions, referred to as globally regular functions. The criterion is then used to establish global regularity of a few classes of functions in a very simple manner.
TL;DR: In this article, a method for the rapid determination of 144Ce, 137Cs, 89Sr, 90Sr and 140Ba in surface-waters and atmospheric water precipitations by ion exchange is presented.
Abstract: A method for the rapid determination of 144Ce, 137Cs, 89Sr, 90Sr and 140Ba in surface-waters and atmospheric water precipitations by ion-exchange is presented. It can be applied to samples with total calcium-magnesium content up to 110 meq. The limit of detection amounts to 0,005 pCi/l for 144Ce, 0.006 pCi/l for 137Cs, 0.004 pCi/l for 90Sr and 0.006 pCi/l for 140Ba with a 30 l sample. These sensivities can be improved for a further few times using a battery of columns.
TL;DR: The thermal conductivity of a Rochelle salt single crystal has been measured in the temperature range from −110°C to +33°C, and significant anomalies were found at both Curie temperatures as discussed by the authors.
TL;DR: In this article, a method for measuring the total absorption cross sections for photons in the energy region of 10 − 30 MeV was described, using a 4 channel Compton spectrometer with a 2% resolution.
Abstract: A new class of positive network elements is defined. It is a subclass of nonlinear resistive, capacitive and inductive (and possibly locally active) n-port [or (n+1)-terminal] elements. A positive network element possesses all possible hybrid descriptions. Also, all incremental driving-point resistances for a positive resistive element are themselves positive, as are capacitive and inductive elements. Many transistor and other active devices can be modelled as positive network elements.
TL;DR: The present study showed that p-chloromercuribenzoate and dithiothreitol are inadequate for this purpose, since their activity is not specific for the cholinoreceptor, but extends over a wide range of pharmacological responses.
TL;DR: In this article, an approximation for the family of N-projected BCS functions ΦBCSN (x, t) with u and v depending on a single generator parameter t in an appropriate way, is formulated, in which the subspace H Φ is truncated to much smaller dimension by orthogonalizing the basis Φ BCSN and by rejecting the new basic vectors with small norm.
TL;DR: In this paper, it was shown that any ferroelectric mode contribution, if at all present, is masked by the random flips of the D 2 O molecules, and the results were extended to 2 D spin lattice relaxation times.
TL;DR: The device described has been designed with simplicity of operation and ultimate low production cost in mind, while designed primarily for the blind, it will also be of value in such fields as analysis of speech and data processing.
Abstract: The device described has been designed with simplicity of operation and ultimate low production cost in mind. While designed primarily for the blind, it will also be of value in such fields as analysis of speech and data processing.
TL;DR: In this article, aussagen uber stabile Lagen werden mittels Anhaufungen gleicher Blaschen uberpruft, die auf einer Seifenlosung schwimmen.
Abstract: Es werden in der Ebene die stabilen Lagen einer Anzahl starrer Kugeln, zwischen denen anziehende zentrale Krafte wirken, untersucht. Fur den speziellen Fall, bei dem die Kraft umgekehrt proportional zur5 ist, wird die Bindungsenergie der letzten zugefugten Kugel in die durchschnittliche Bindungsenergie einer Kugel in Abhangigkeit von der Kugelzahl errechnet. Die Aussagen uber stabile Lagen werden mittels Anhaufungen gleicher Blaschen uberpruft, die auf einer Seifenlosung schwimmen.
TL;DR: In this article, a thought experiment is considered which contrary to other experiments encountered usually in connection with the clock paradox can be described entirely in the scope of special relativity, and it is shown that it can be viewed as a special case of the time paradox.
TL;DR: In this paper, an ion exchange method for (Mg + Ca)-Sr-Ba is presented on a column filled with Dowex 50 W, X-8 by 0.6 M ammonium glycolate-0.2 M NaCl, pH 5 and 1.4 mM NaCl as eluents.
Abstract: An ion-exchange method for magnesium, calcium, strontium and barium determination in mixtures containing up to 6 meq. each of them is presented. The separation of (Mg + Ca)-Sr-Ba is performed on a column filled with Dowex 50 W, X-8 by 0.6 M ammonium glycolate-0.2 M NaCl, pH 5 and 1.2 M ammonium glycolate-0.4 M NaCl, pH 5 as eluents. Calcium is separated from magnesium by precipitation as oxalate and determined by titration with permanganate. Magnesium is isolated as magnesium ammonium phosphate and determined acidimetrically. Strontium and barium are precipitated as carbonates and then weighed or determined by EDTA titration. The errors of determination do not exceed ± 2%.