Showing papers by "University of Zagreb published in 1972"
TL;DR: The phase layer on the surface of passivated chromium is electrically non-homogeneous as mentioned in this paper, and it is a layer with semiconducting properties with a band gap of about 0·8 eV.
39 citations
TL;DR: In this paper, the impurity resistivity of Al-based 3-d transition metal alloys has been investigated at 4.2 and 500 K. The results show that the resistivity at 500 K follows a double peaked curve characteristic of noble metal alloy alloys containing 3 d impurities.
32 citations
TL;DR: In this paper, it was shown that the presence of metastable phases in as-quenched alloys highly increases the resistance to decomposition of Al-W solid solutions.
Abstract: Al-W alloys with a W content from 4.3 to 11.7 wt% were rapidly quenched, using the two-piston quenching method. X-ray examination showed that in as-quenched alloys two kinds of samples appeared; multiphase samples and single-phase samples. Multiphase samples contained supersaturated Al-W solid solutions (α-Al), Al4W and two unknown phases, all of which were metastable. In single-phase samples α-Al was present as the only phase. In these samples α-Al began to decompose at temperatures as low as 100° C. During the decomposition of these solid solutions two other new phases were observed, the unit cell constants of which were determined. Experiments with isochronal and isothermal annealing showed that the presence of metastable phases in as-quenched alloys highly increases the resistance to decomposition of Al-W solid solutions. The possible reason for this behaviour is discussed.
27 citations
TL;DR: In this paper, the Stark broadening of ArI 7147.04, 7272.93, 7067.2, 6965.43 A lines was investigated in a wall-stabilized argon-arc plasma.
Abstract: The Stark broadening of ArI 7147.04, 7272.93, 7067.2, 6965.43 A lines was investigated in a wall-stabilized argon-arc plasma. The temperature was varied from 10,100 to 12,500°K, and the electron density from 1.9 to 8.8×10 16 cm -3 . In the observed plasma conditions, the last two lines were self-absorbed owing to their optical depths. Correction to the optically thin line was made, and the quadratic Stark effect halfwidths were compared with Griem's theoretical halfwidths. Within the limits of experimental error, the halfwidths of lines of 7147, 7273, 6965 and 7067 A were found to be in agreement with theory.
21 citations
TL;DR: The effects of ACTH, GH, prolactin, adrenalectomy and corticoids upon the female rat preputial glands were investigated and the effects of endogenous and exogenous hormones were compared and found to coincide.
Abstract: The effects of ACTH, GH, prolactin, adrenalectomy and corticoids upon the female rat preputial glands were investigated. In two different types of experiments the effects of endogenous and exogenous hormones were compared and found to coincide. Endogenous hormone effects were studied in rats inoculated with a transplantable mammotropic pituitary tumor which secretes large amounts of ACTH and prolactin. Between the 20th and 30th days after inoculation the tumor produced a 44% weight increase of the preputial glands in intact animals and a 200% enlargement in adrenalectomized rats. Effects of adrenalectomy were averted by administration of corticoids. The stimulatory effect of ACTH and GH, the synergistic effects between GH and prolactin, between GH and ACTH, and among all three hormones were demonstrated by exogenous administration of these pituitary hormones. The changes produced by ACTH, GH and prolactin alone, or by combinations of these hormones, in the DNA, RNA and protein contents, RNA/DNA ratio, cel...
21 citations
Book•
31 Jul 197220 citations
TL;DR: In a liveborn infant with 69 chromosomes some symptoms have been found which were also seen among the cases of triploidy reported before, and the characteristic face, syndactyly, coloboma, abnormal neurological and sexual development, and increased number of digital whorls are the most frequent findings.
Abstract: In a liveborn infant with 69 chromosomes some symptoms have been found which were also seen among the cases of triploidy reported before. The characteristic face, syndactyly, coloboma, abnormal neurological and sexual development, and increased number of digital whorls are the most frequent findings. In our case we found arhinencephaly, bilateral microphthalmy with colobomata iridis, cheilognathopalatoschisis, syndactyly of the III–IV finger, bilateral simian crease, mola hydatiformis of placenta. There was strong Rh immunization of the mother who was rh negative, possibly due to an increased erythrocyte antigen strength, because of triple gene dosage of the child.
19 citations
TL;DR: It is found that F.hepatica, M.benedeni and P.cervi are both arginine and pyrimidine dependent, and the tissues of these worms cannot synthesize carbamyl phosphate.
Abstract: 1. 1. Neither the mitochondrial nor the celesol fraction of the hormogenate of Fasciola hepatica , Moniezia benedeni and Paramphistomum cervi displays any ability for synthesis of carbamyl phosphate either with ammonia-dependent or with glutamine-dependent or glutamine and N-acetyl l -glutamate-dependent carbamyl phosphate synthetase. The conclusion is reached that these parasitic worms are not able to synthesize the carbamyl phosphate. 2. 2. Ornithine transcarbamylase is absent from both the mitochondrial and celoso fractions in all three parasites, which eliminates the possibility of synthesis of citrulline. 3. 3. Aspartate transcarbamylase is present in the celosol fractions of all three flatworms. The possibility of synthesis of carbamyl aspartat is out of the question, for the tissues of these worms cannot synthesize carbamyl phosphate. 4. 4. The conclusion is that F.hepatica, M.benedeni and P.cervi are both arginine and pyrimidine dependent.
14 citations
TL;DR: In this paper, the isolation and characterization of hexaminium salts of 2-chloroacetamido-5-chlorobenzophenone (I) and 2-(N-methyl)chlorocarabinone carbonyl group on the hexamine moiety has been reported.
13 citations
01 Jan 1972
TL;DR: The results suggest that sisal dust does not cause byssinosis but affects ventilatory function of the exposed workers.
Abstract: A study of respiratory symptoms and ventilatory function was made in a group of 51 non-smoking female workers exposed to sisal dust and 51 control subjects matched in age and height. A higher prevalence of persistent cough (17.6%), persistent phlegm (13.7%), chronic bronchitis (9.8%) and nasal catarrh (19.6%) was found in sisal workers than in controls (5.9, 5.9, 5.9 and 0%, respectively). Not a single case of byssinosis was found in the workers surveyed.
12 citations
TL;DR: In this article, the extraction mechanism for the extraction of zirconium from oxalate solutions and of niobium from fluoride solutions was proposed, and the efficiency of extraction by 2-carbethoxy-5-hydroxy-1-(4-tolyl)-4-pyridone (HA) dissolved in chloroform was studied.
Abstract: Extraction of zirconium, niobium and tantalum from oxalic and hydrofluoric acid solutions, by 2-carbethoxy-5-hydroxy-1-(4-tolyl)-4-pyridone (HA) dissolved in chloroform was studied. Extraction mechanism for the extraction of zirconium from oxalate solutions and of niobium from fluoride solutions is proposed. Separation of zirconium and niobium from oxalate solution as well as from fluoride solution and tantalum and niobium from fluoride solution is described. Back-extraction of these metals is possible by hydrofluoric and oxalic acid. Results obtained show that the efficiency of extraction by HA decreases in the sequence tantalum > niobium > zirconium.
TL;DR: In this article, it was shown that the intersection of a decreasing sequence of AR's is a fundamental absolute retract (FAR) and that every FAR can be obtained in this way.
Abstract: K. Borsuk proved that the intersection of a decreasing sequence of AR's is a fundamental absolute retract (FAR) and he raised the question whether every FAR can be obtained in this way ([3], Problem 9.6, p.74). The purpose of this paper is to give an affirmative answer by proving the stronger assertion that every FAR is the intersection of a decreasing sequence of Hilbert cubes. An analogous result for the finite-dimensional case is also established.
TL;DR: In this paper, the separation of protactinium from thorium is described, and the mechanism of thorium extraction has been studied based on the dependence of the distribution ratios on the concentration of HA in the organic phase and on the hydrogen ion concentration in the aqueous phase, and further confirmed by elemental analysis and by the i.r. spectra.
TL;DR: In this article, the authors analyzed the number of earthquakes felt in Zagreb, Yugoslavia, during the 100 year period 1869-1968 and their distribution in time is shown.
Abstract: Statistical information on the number of earthquakes felt in Zagreb, Yugoslavia, during the 100 year period 1869–1968 is given and their distribution in time is shown. The largest earthquake in each year is analysed, first by the distribution-free method and then by means of the theory of extremes afterJenkinson. By the latter method we conclude that there is an upper limit to the possible intensity of earthquakes in Zagreb. The results are compared with the data for Californial although the seismicity of Zagreb area is rather high, that of California is considerably higher.
TL;DR: In this article, it was shown that thin monocrystalline films of PbS grown epitaxially from the vapour on KCl in a vitreous silica hot wall system, present lower specular reflectivity than expected.
Abstract: Thin monocrystalline films of PbS grown epitaxially from the vapour on KCl in a vitreous silica hot wall system, present lower specular reflectivity than expected. Electron micrography shows that the surfaces of the films are studded with a multitude of small blobs. They scatter partially the incident light. By electron probe microanalysis and Bragg diffractometry it was found that the blobs are made up of elemental Pb and PbS. As basic lead sulphates were also found on the films the presence of elemental Pb is attributed to the roast reduction reaction. We believe that the silica of the apparatus provides the major part of the oxygen involved in this reaction.
TL;DR: The nonrelativistic impulse approximation for the induced-tensor interaction has been analyzed in detail in detail as mentioned in this paper, showing that this process is sensitive to the presence of the induced tensor interaction.
Abstract: The nonrelativistic impulse approximation for the induced-tensor interaction has been analyzed in detail. $\mathrm{ft}$ values for mirror transitions have been calculated using electron Coulomb wave functions for the extended charge distribution and introducing higher-order corrections. 14 angular $\ensuremath{\beta}\ensuremath{-}\ensuremath{\gamma}$ correlations, the $\ensuremath{\beta}$ transition being allowed, have been analyzed, showing that this process is sensitive to the presence of the induced-tensor interaction. The amount of information about the induced tensor at present obtainable from circular $\ensuremath{\gamma}$ polarization in nuclear transitions has been investigated. A limit on the induced-tensor coupling constant has been obtained which does not contradict the evidence based on $\mathrm{ft}$ values. $\ensuremath{\beta}\ensuremath{-}\ensuremath{\gamma}$ angular correlations seem to yield evidence for the weak-magnetism term, while not excluding the existence of the induced tensor.
TL;DR: In this paper, the halfwidths of a group of ArI lines measured with an apparatus described in an earlier paper were obtained for the half widths of the ArI line.
Abstract: Results have been obtained for the halfwidths of a group of ArI lines measured with an apparatus described in an earlier paper.
TL;DR: In this article, a free burning d.c. arc with copper electrodes was observed in an interval of currents in which a transition to the local thermal equilibrium was expected, and the populations of copper atoms were determined by means of the absolute line intensities, and measured using line profiles and the ratio of the intensities of autoionized and non-autoionized lines.
TL;DR: In this article, the main results of this paper are the following two theorems: 1) If a function is an additive bimorphism, then it is a quadratic form on the group G and 2) if f(x y ) + f (x y -1) = 2 f( x ) + 2 f ( y ) (1) holds for all x, y, zEG.
Abstract: A function B:G x G ~ A is called an additive bimorphism of a group G into a commutative group A if B (xy, z) = B (x, z) + B (y, z) B (z, xy) = B (z, x) + B (z, y) holds for all x, y, zEG. A function f : G ~ A is a quadratic form on G if f ( x y ) + f ( x y -1) = 2 f ( x ) + 2 f ( y ) (1) holds for all x, yeG. We assume that aeA and 2a = 0 implies a =0. I f B is an additive bimorphism then x ~ g (x, x) is a quadratic form on G. The main results of this paper are the following two theorems.
TL;DR: The correlation coefficient between the corrected estimated maximum daily SO 2 concentration and the true maximum concentration was found to be r = 0.94, showing that the proposed method yields satisfactory estimates of these concentration parameters.
TL;DR: Oscillator strengths of Ar I lines were measured in a certain interval of electric currents in an argon cascade are in order to determine the critical electron density necessary for the establishment of LTE in argon plasmas.
TL;DR: In this article, the anodic processes on gold in chloride, sulphate and mixed chloride-sulphate electrolytes have been investigated, and the experimental results point to different mechanisms of the processes depending on the electrolyte composition.
TL;DR: In this paper, the shear mode spectrum in Nb 3 Sn is interpreted in terms of the generalized Labbe- Friedel model and the Kohn anomaly at low temperatures.
Journal Article•
TL;DR: Quantitative evaluation of polyacrylamide gel electrophoretic results is essential for comparative macromolecular mapping and comparison of the two different types of comparison must rely upon statistical evaluation of densitometric recordings.