Quispe E.C.,Occidente University |
Lopez-Fernandez X.M.,University of Vigo |
Mendes A.M.S.,University of Coimbra |
Marques Cardoso A.J.,University of Coimbra |
Palacios J.A.,University of Valle
2011 IEEE International Electric Machines and Drives Conference, IEMDC 2011 | Year: 2011
This paper presents the results of an experimental study on derating of an induction motor under different voltage unbalanced conditions and its comparison with the NEMA standard MG1 voltage unbalance derating graph. During the derating tests the 4 kW squirrel cage induction motor temperature rise was kept constant at the rated value and the windings temperature was measured on-line by means of an accurate digital thermal monitoring system with nine thermocouples positioned in both stator and rotor circuits. The obtained results show that the positive sequence voltage plays an important role in the derating performance of the induction motor under unbalanced conditions, and that the unbalance voltage indices currently used do not allow for accurately measuring this influence. © 2011 IEEE.
Study of temperature and indium concentration-dependent dielectric constant and electron affinity effects on the exciton optical transition and binding energy in spherical GaSb-Ga1-xInxAsySb 1-yGaSb quantum dots
Snchez-Cano R.,Occidente University |
Porras-Montenegro N.,University of Valle
Physica E: Low-Dimensional Systems and Nanostructures | Year: 2010
We have study the heavy-hole exciton states in GaSbGaInAsSbGaSb type-I spherical Quantum Dots, using temperature-dependent static dielectric constant and electron affinity, with a finite height potential barrier, as a function of the quantum dot radius for several values of Indium concentration. Our calculations have been worked out using interpolating methods to find the temperature and Indium concentration dependence of both the dielectric constant and electron affinity, in order to determine the conduction and valence band-offsets in GaSbGaInAsSbGaSb heterostructure by application of the Electron Affinity Rule. We have calculated the exciton binding energy and the corresponding transition energy from the exciton ground state to the heavy-hole level, using a variational procedure within the effective-mass approximation. We have found that the binding energy of the heavy-hole exciton presents changes due to the temperature dependence of the electron affinity and static dielectric constant. However our results for the transition energy from the exciton ground state to the heavy-hole level coincide with those reported in a previous theoretical work, where we had found a very good agreement with photoluminescence and photoreflectance experimental studies at T=12 K in Ga1-xInxAsySb1-y films grown over GaSb substrates by liquid phase epitaxy.
Gonzalez-Marquez L.C.,Occidente University
Revista Internacional de Contaminacion Ambiental | Year: 2014
To understand the effect of salinity on the adsorption of the herbicide atrazine in two soils from a Mexican agricultural area, the influence of sodium and calcium chloride concentrations were determined. Adsorption experiments were performed with soil samples from Irrigation District 063 (DR 063), Guasave, Sinaloa, Mexico, suspended in 10 mM CaCl2, in the presence of several concentrations of different electrolytes and atrazine (0.01, 0.05, 0.1, 0.5 and 1.0 mg/L) with radioactive tracer (347.4 Bq U-ring-14C, Sigma Chemical Company, St. Louis, MO, USA). It was found that for all the electrolytes, the time required to reach equilibrium adsorption of atrazine was less than 24 h and the adsorption isotherms were adjusted to Freundlich model. The presence of sodium in the aqueous solution favored the adsorption and inhibited desorption of atrazine in soils. Increasing the concentrations of sodium and calcium to about 40 mM and 60 mM, respectively, did not significantly affect (P <0.05) the adsorption of atrazine. However, there were differences in desorption of the herbicide with the increase of salts concentrations. The results of this study indicate that increased salinity, mainly caused by increased sodium concentrations in the soil-water system, has important effects on the fate of atrazine, due to salinization of soils favors the adsorption of atrazine, and inhibits its desorption. It is important to consider these properties when application options are analyzed as well as in the management and remediation of soils contaminated with atrazine.
Chan E.K.L.,University of Florida |
Damoiseaux J.,Maastricht University |
Carballo O.G.,University Institute of the Italian Hospital |
Conrad K.,TU Dresden |
And 10 more authors.
Frontiers in Immunology | Year: 2015
During the 12th International Workshop on Autoantibodies and Autoimmunity (IWAA) held in Sao Paulo, Brazil, on August 28, 2014, a full day session was devoted to establishing a consensus on the nomenclature of staining patterns observed in the antinuclear antibody (ANA) indirect immunofluorescence test on HEp-2 cells. The current report summarizes the collective agreements with input from the host Brazilian and international communities that represented research, clinical, and diagnostic service laboratories. Patterns are categorized in three major groups (nuclear, cytoplasmic, and mitotic patterns) and each pattern has been defined and described in detail. The consensus nomenclature and representative patterns are made available online at the International Consensus on Antinuclear antibody Pattern (ICAP) website (www.ANApatterns.org). To facilitate continuous improvement and input, specific comments on ICAP are encouraged and these will be discussed in subsequent ICAP meetings. The ultimate goal with the establishment of the ICAP is to promote harmonization and understanding of autoantibody test nomenclature, as well as interpretation guidelines for ANA testing, thereby optimizing usage in patient care. © 2015 Chan, Damoiseaux, Carballo, Conrad, de Melo Cruvinel, Francescantonio, Fritzler, Garcia-De La Torre, Herold, Mimori, Satoh, von Mühlen and Andrade.
Sandoval P.H.,Occidente University
Journal of Crustacean Biology | Year: 2012
Total protein, lipid and carbohydrate variations for the whole embryonic development were measured every 48 hours in samples of eggs of Macrobrachium occidentale (Holthuis), 1950, a small freshwater caridean. Proteins are the main component followed by lipids and carbohydrate only as minor constituent. Most required energy seems to come from metabolism of fat, which was profusely depleted during the whole of development while proteins seem to be mostly utilized for tissue formation. Details of morphological changes of every developmental step are also presented and a comparison of present results with works of other prawn eggs is discussed. © 2012 The Crustacean Society. Published by Brill NV, Leiden.