Showing papers by "National University of La Plata published in 1969"
TL;DR: In this paper, the anodic and cathodic current/voltage curves are characterized by two well defined waves, and the total reactions related to the first and second anodic waves are respectively 3I− = I3− + 2 e and 2I3− = 3I2+2 e, while the reverse reactions represent the second and first cathodic waves respectively.
107 citations
TL;DR: In this article, the electrochemical behavior of polycrystalline nickel in acid solutions containing large excess either of NaCl or NaClO4 has been investigated, at potentials either more positive or negative than the rest potential of the metal.
61 citations
TL;DR: In this paper, the kinetics and mechanisms of the iodide and tri-iodide ion reduction and ion oxidation on platinum have been determined, from a study of the electrochemical kinetic behaviour of DMSO solutions containing an iodine/sodium-ide ratio greater than one.
26 citations
TL;DR: In this paper, a variational method for the self-consistent solution of the nuclear many body problem with the inclusion of correlations is formulated, and the trial function in this multiconfiguration-Hartree-Fock (MCHF) theory is a linear combination of unrestricted Slater determinants.
Abstract: A variational method for the self-consistent solution of the nuclear many body problem with the inclusion of correlations is formulated. The trial function in this multiconfiguration-Hartree-Fock (MCHF) theory is a linear combination of unrestricted Slater determinants. The MCHF equations are given and a simple procedure for solving them is outlined. A great advantage of this method is that it also yields the excited states. It is shown that the trial function is stable against particle-hole excitations. Therefore the Slater determinants differ from each other at least by two particle — two hole excitations. This method is applied to the Lipkin model. In the MCHF method the difference to the exact solution is reduced by a factor three to ten compared with the corresponding value in the HF approach.
22 citations
TL;DR: In this article, the Lipkin model is extended to yield a non-trivial Hartree-Fock (HF) solution for any coupling constant of the two-body force.
Abstract: The Lipkin model is extended to yield a non-trivial Hartree-Fock (HF) solution for any coupling constant of the two-body force In this model the multi-configuration Hartree-Fock (MCHF) approach is compared with the exact solution and with the HF solution The results show a strong superiority of the MCHF method over the HF approximation
22 citations
TL;DR: The IR spectra of Mg3(VO4)2, Ca3VO4), Ca3 VO4 2, Sr3VO 4 2, Ba3 VO 4 2, and Ba3 V4 2 were recorded between 4 000-600 cm−1 and interpreted using the site symmetry rules as discussed by the authors.
Abstract: Die IR-Spektren der Verbindungen Mg3(VO4)2, Ca3(VO4)2, Sr3(VO4)2 und Ba3(VO4)2 wurden in Bereich 4 000–600 cm−1 aufgenommen und mittels der Site-Symmetrie-Regeln gedeutet.
The IR spectra of Mg3(VO4)2, Ca3(VO4)2, Sr3(VO4)2 and Ba3(VO4)2 were recorded between 4 000–600 cm–1 and interpreted using the site symmetry rules.
21 citations
TL;DR: In this article, a combination principle is used as a test of the accuracy of the measurements for 278 thorium lines in the range 2747-4572 A. The average wavelength error is about one part in 3 to 6×107 and the average root-mean-square deviation is 1.6×10−4 A between the results for different spacers.
Abstract: Interferometrically measured wavelengths are given for 278 thorium lines in the range 2747–4572 A. The light source is a liquid-nitrogen-cooled hollow-cathode lamp with 1 torr of argon as the carrier gas. Each line is measured from interferograms taken with a Fabry–Perot interferometer having 20-, 40-, and 50-mm spacers, and the results are averaged after making the correction for dispersion of optical path. The combination principle is used as a test of the accuracy of the measurements. The average wavelength error is about one part in 3 to 6×107 and the average root-mean-square deviation is 1.6×10−4 A between the results for the different spacers. Our results are compared with those of different investigators and indicate a relative shift of +4×10−4 A when the electrodeless discharge tube is compared with the hollow-cathode lamp. The origin of this shift is discussed and attributed partly to differences in the standards used to calibrate the interferometer and partly to differences in the light sources.
19 citations
TL;DR: In this paper, the diffusion coefficients of the solvated proton and molecular hydrogen were estimated and interpreted in terms of the structure of the ions in the aprotic solvent.
13 citations
TL;DR: In this paper, the rate of a non-isothermal free convection process has been measured at different temperature gradients in an electrochemical cell having parallel vertical plate copper electrodes, the reaction being the electrodeposition of copper from a copper sulfate-sulphuric acid solution.
12 citations
TL;DR: Aedes albifasciatus, a floodwater mosquito, is widely distributed in freshwater habitats in Argentina and at high population densities it is an important pest in urban areas.
Abstract: Aedes albifasciatus . a floodwater mosquito, is widely distributed in freshwater habitats in Argentina. At high population densities it is an important pest in urban areas. A two year study was conducted in a natural population of A. albifasciatus around La Plata area, Buenos Aires province, Argentina. The breeding site was weekly sampled from May, 1996 to April, 1998. Immature stages of A. albifasciatus were collected with a standard 300 mI dipper. Each sample unit consisled of 100 dipper. Highest den sities of mosquito larvae occurred when the breeding site was flooded among 90 and 100 % ofits capacity after remaining dry for several days or weeks. The larvae required between six and eight days lo become adult in summer (temperature mean 24.6 oC in January and 21.3 oC in February). In autumn-winter, 43 days (temperature mean 10.6 oC) and in spring 22 days (temperature mean 15.5 oC).
11 citations
TL;DR: In this article, anodic and cathodic processes involved in the electrolysis of different oleums were studied on platinum rotating disk electrodes at 25 and 50°C, in a Anodic processes do not change with the rate of stirring.
TL;DR: Ein new Alkaloid wurde aus der Rinde von Pterogyne nitens Tul (Leguminosae) isoliert und seine Struktur bestimmt, handelt sich um das N,N-Di(isopenten-2-yl)-guanidin.
Abstract: Ein neues Alkaloid, Pterogynin, wurde aus der Rinde vonPterogyne nitens Tul. (Leguminosae) isoliert und seine Struktur bestimmt. Es handelt sich um das N,N-Di(isopenten-2-yl)-guanidin.
TL;DR: In this article, a method for solving the RPA equations without discarding any term in the case of separable interactions is proposed, specialized to the SDI for both spherical and deformed nuclei and applied in two simple examples.
Abstract: A method is discussed for solving the RPA equations without discarding any term in the case of separable interactions It is specialized to the SDI for both spherical and deformed nuclei and applied in two simple examples
TL;DR: In this article, preliminary experimental results on the interaction between the first and second positive laser systems in N 2 acting simultaneously were reported. But the experimental results were limited to the first positive laser system.
TL;DR: In this paper, the authors studied the kinetics of the electrochemical formation of hydrogen on differently prepared prepared palladium electrodes in the electrolysis of molten potassium bisulphate in the temperature range 240 to 330°C.
Journal Article•
TL;DR: The authors describe un case of parasitismo por Dioctophyme renale, resenando las caracteristicas clinicas propias con que se presento and el resultado of los examenes radiologic, hematologic, and urinarios that fueron practicados.
Abstract: RESUMEN: El autor describe un caso de parasitismo por Dioctophyme renale, resenando las caracteristicas clinicas propias con que se presento y el resultado de los examenes radiologicos, hematologicos y urinarios que fueron practicados, considerando que el caso constituye un aporte mas en el siempre polemico tema de la evolucion del parasito en el hospedador definitivo. Analecta Veterinaria 1(1): 35-41; 1969
TL;DR: In this paper, the authors identify and analyse the views that students build during the first years of the degree in Sciences and Technology of the National University of Quilmes, with regard to the conditioners to their academic career.
TL;DR: In this article, die Herstellung der Verbindungen Sr2(MnO4)OH and Sr2 (mnO 4)OH·2H2O beschrieben wird die Gitterkonstanten wurden aus den entsprechenden Pulverdiagrammen berechnet.
Abstract: Es wird die Herstellung der Verbindungen Sr2(MnO4)OH und Sr2(MnO4)OH·2H2O beschrieben. Die Gitterkonstanten wurden aus den entsprechenden Pulverdiagrammen berechnet. Die Infrarotabsorptions-und die Reflexionsspektren im Sichtbaren sowie das magnetische und thermische Verhalten wurden untersucht und kurz besprochen.
TL;DR: Using three-body models, the binding energies of the ground states of 6He and 6Li were computed in this article, and the binding energy of 6Li and 6He was shown to be the same as 6Li.
Journal Article•
TL;DR: A Micrococcus cerificans strain was grown on simple media with n‐hexadecane or gas oil as sole carbon sources and with the exception of sulfur amino acids the amino acid distribution compares favorably with the FAO standard reference protein.
Abstract: A Micrococcus cerificans strain was grown on simple media with n-hexadecane or gas oil as sole carbon sources. Samples of cellular material recovered from hexadecane or gas oil fermentations do not appear to differ significantly in their composition. The protein content varied from 68 to 75%. With the exception of sulfur amino acids the amino acid distribution compares favorably with the FAO standard reference protein.
The biological value of cell protein recoveered from hexadecane fermentations was 67 (cascin, 70). In the case of gas oil grown cells, the cell material recovered had to be completely purified in order to improve its protein quality. After fully extraction of undersirable fraction with petroleum ether in a Soxhlet apparatus the biological value observed was 63.
TL;DR: In this paper, a detailed study of the Davydov model emphasizes some special features which are of interest for obtaining a clear picture of the characteristics, merits and range of applicability of the model.
31 Dec 1969
TL;DR: Deleuze and Guattari as mentioned in this paper define filosofia como creacion de conceptos, and define personajes conceptuales that contribuyan a definir concepts.
Abstract: En el sugestivo libro aparecido en 1991 ?Que es la filosofia? Gilles Deleuze y Felix Guattari definen la filosofia como creacion de conceptos. Anaden asimismo que esos nuevos conceptos necesitan personajes conceptuales que contribuyan a definirlos. No son muchas las veces que se asiste a la creacion de un concepto. Un ejemplo recurrente es el cogito cartesiano: ?por que es verdaderamente una creacion? En primer lugar porque no supone otros conceptos pero, sin embargo, es comprensible porque esta sostenido por una imagen presupuesta: todo el mundo sabe que significa pensar. Con todo, sostienen los autores, "hay algo a medio camino entre el plano del concepto y el plano preconceptual, que va de uno a otro" (DELEUZE; GUATTARI, 1993, p 63-ss). Es el personaje conceptual. En el caso del cogito, sostienen los autores, se trata del Idiota: el es quien dice Yo, el es quien lanza el cogito ... El Idiota es el pensador privado por oposicion al profesor publico, el profesor universitario.
TL;DR: In this article, 13 laser lines of the first positive system of N 2 were detected and their wavelengths measured, and eleven laser lines were classified and two more reclassified; they were then classified and reclassified.
Abstract: Thirteen laser lines of the 1-0, 2-1, and 3-1 bands of the first positive system of N 2 were detected and their wavelengths measured. Eleven laser lines were classified and two more reclassified.
TL;DR: In this paper, a formula is proposed to improve the approximation of the Jost function based on properties of Jost functions, based on which a matrix element of the potentials can be computed.
TL;DR: In this paper, the Paschen discontinuity in stars with T ≥ 104K was measured and it was shown that the D P/DB ratio increases with temperature faster than expected.
Abstract: Measurements of the Paschen discontinuity in stars withT
eff≥104K leads to the conclusion that theD
P/DB ratio increases with temperature faster than expected. The increase ofD
P/DB with (logg)−1 is also steep.
TL;DR: A species of Trichogrammatid reared from the eggs of Entypotrachelus meyeri Kolbe (Col., Curculionidae) is described as new and is named Oligositoides semicinctium.
Abstract: A species of Trichogrammatid reared from the eggs of Entypotrachelus meyeri Kolbe (Col., Curculionidae) is described as new and is named Oligositoides semicinctium .