Accurate Mixed Electrical and Electromagnetic Model of a 6,5㎸ IGBT Module

E. Batista,J. M. Dienot,M. Mermet-Guyennet,A. Castellazzi,M. Ciappa,W. Fichtner 전력전자학회 2007 ICPE(ISPE)논문집 Vol.- No.-

The compact model development of a 6,5㎸ field-stop IGBT module is presented. In particular, the model considers the realistic interconnection of IGBTs and anti-parallel diodes found in commercial modules, providing, next to semiconductor physics, an accurate description of electro-magnetic (EM) phenomena associated with the package and layout. A selection of simulation examples demonstrates the usefulness of the proposed solution.

A Distribution of Relaxation Time Approach on Equivalent Circuit Model Parameterization to Analyse Li-ion Battery Degradation

E. Aguilar Boj,S. Azizighalehsari,P. Venugopal,G. Rietveld,T. Batista Soeiro 전력전자학회 2023 ICPE(ISPE)논문집 Vol.2023 No.-

The time-varying and complex electrochemical behaviour inherent to Li-ion batteries cause a great challenge to its diagnostics and prognostics. Electrochemical impedance spectroscopy (EIS) based mapping of the impedance datasets as a function of frequency to equivalent electrical elements specific to physical/chemical characteristics is vital to validate the equivalent circuit models (ECM). Distribution of relaxation times (DRT) is a method to convert the EIS impedance spectra as a function of frequency to a distribution of time constants representing an RC network in a battery ECM. Modeling the battery with detailed consideration of EIS data is the main advantage of the DRT technique. In this work, the whole process of modeling a large amount of EIS data has been done automatically, selecting only the dominant peaks present during the entire battery ageing to increase computational efficiency. The results show that good accuracy is achieved in monitoring the degradation of a Li-ion cell and that the dispersion of the different fits is consistent throughout the data set.

A New Method to Assess Entrepreneurship Competence in University Students Using Based on Plithogenic Numbers and SWOT Analysis

Noel Batista Hernandez,Maikel Y. Leyva Vazquez,Erick Gonzalez Caballero,Lilia E. Valencia Cruzaty,Wilmer Ortega Chavez,Florentin Smarandache 한국지능시스템학회 2021 INTERNATIONAL JOURNAL of FUZZY LOGIC and INTELLIGE Vol.21 No.3

This study introduces a method to measure the implementation of the training strategy of entrepreneurship competence as a contribution to the integrity and quality of future graduates from any higher education institutions. For this purpose, the theory of plithogenic sets was applied. These sets were defined to model concepts arising from the dynamic interaction of other simpler ones, which may have contradictions among each other and include neutralities or indeterminacies. To the best of our knowledge, this is the first time that plithogenic sets are applied in the mathematical modeling of entrepreneurship competence or any other pedagogic competence. The plithogenic numbers are represented and applied to SWOT (Strengths, Weaknesses, Opportunities, and Threats) analysis. This method was successfully applied at the University of Guayaquil, Ecuador. It is a simple method that includes an assessment based on linguistic terms and indeterminacies.

Parametric numerical study of wind barrier shelter

Telenta, Marijo,Batista, Milan,Biancolini, M.E.,Prebil, Ivan,Duhovnik, Jozef Techno-Press 2015 Wind and Structures, An International Journal (WAS Vol.20 No.1

This work is focused on a parametric numerical study of the barrier's bar inclination shelter effect in crosswind scenario. The parametric study combines mesh morphing and design of experiments in automated manner. Radial Basis Functions (RBF) method is used for mesh morphing and Ansys Workbench is used as an automation platform. Wind barrier consists of five bars where each bar angle is parameterized. Design points are defined using the design of experiments (DOE) technique to accurately represent the entire design space. Three-dimensional RANS numerical simulation was utilized with commercial software Ansys Fluent 14.5. In addition to the numerical study, experimental measurement of the aerodynamic forces acting on a vehicle is performed in order to define the critical wind disturbance scenario. The wind barrier optimization method combines morphing, an advanced CFD solver, high performance computing, and process automaters. The goal is to present a parametric aerodynamic simulation methodology for the wind barrier shelter that integrates accuracy and an extended design space in an automated manner. In addition, goal driven optimization is conducted for the most influential parameters for the wind barrier shelter.

Parametric numerical study of wind barrier shelter

Marijo Telenta,Milan Batista,M.E. Biancolini,Ivan Prebil,Jožef Duhovnik 한국풍공학회 2015 Wind and Structures, An International Journal (WAS Vol.20 No.1

This work is focused on a parametric numerical study of the barrier\'s bar inclination shelter effect in crosswind scenario. The parametric study combines mesh morphing and design of experiments in automated manner. Radial Basis Functions (RBF) method is used for mesh morphing and Ansys Workbench is used as an automation platform. Wind barrier consists of five bars where each bar angle is parameterized. Design points are defined using the design of experiments (DOE) technique to accurately represent the entire design space. Three-dimensional RANS numerical simulation was utilized with commercial software Ansys Fluent 14.5. In addition to the numerical study, experimental measurement of the aerodynamic forces acting on a vehicle is performed in order to define the critical wind disturbance scenario. The wind barrier optimization method combines morphing, an advanced CFD solver, high performance computing, and process automaters. The goal is to present a parametric aerodynamic simulation methodology for the wind barrier shelter that integrates accuracy and an extended design space in an automated manner. In addition, goal driven optimization is conducted for the most influential parameters for the wind barrier shelter.

Effects of Supplements with Different Protein Contents on Nutritional Performance of Grazing Cattle During the Rainy Season

Figueiras, J.F.,Detmann, E.,Franco, M.O.,Batista, E.D.,Reis, W.L.S.,Paulino, M.F.,Valadares Filho, S.C. Asian Australasian Association of Animal Productio 2016 Animal Bioscience Vol.29 No.12

The objective of this study was to evaluate the effects of supplements with different crude protein (CP) contents on grazing cattle intake, digestibility, ruminal fermentation pattern, and nitrogen (N) metabolism characteristics during the rainy season. Five ruminal and abomasal cannulated Holstein${\times}$Zebu steers (296 kg body weight, BW) were used in a $5{\times}5$ Latin square design. The animals grazed five signal grass paddocks (0.34 ha). The five treatments evaluated were: Control (no supplement) and 1.0 g of supplement/kg BW with 0, 330, 660, and 1,000 g of CP/kg as-fed. The supplement was composed of starch, soybean meal, urea, and ammonium sulphate. There was a positive linear effect ($p{\leq}0.033$) of the CP content in the supplements on the organic matter (OM), CP, and digested OM intakes. The provision of supplements did not increase ($p{\geq}0.158$), on average, total and ruminal digestibilities of OM and CP. However, the increase in CP content in the supplements caused a positive linear effect ($p{\leq}0.018$) on ruminal digestibilities of OM and CP. Additionally, a quadratic effect of the CP contents of the supplements were observed (p = 0.041) for the ruminal digestibility of neutral detergent fiber corrected for ash and protein, with the highest estimate obtained with the CP content of 670 g/kg. The supply of supplements increased (p<0.001) the ruminal ammonia N concentration, which also changed linearly and positively (p<0.001) according to increase in CP content in the supplements. The apparent N balance and relative N balance (g/g N intake) were not, on average, changed ($p{\geq}0.164$) by the supplements supply. However, both showed a tendency of a linear increase ($p{\leq}0.099$) with increasing supplement CP content. The supplements increased (p = 0.007) microbial N production in the rumen, which also changed linearly and positively (p = 0.016) with increasing supplement CP content. In conclusion, protein supplementation in grazing cattle during the rainy season, while stimulating voluntary forage intake, results in higher efficiency of N utilization when compared to energy supplementation. This is a possible response to increased microbial protein synthesis in the rumen and improved N status in the animal body.

SEARCHES FOR LARGE-SCALE ANISOTROPY IN THE ARRIVAL DIRECTIONS OF COSMIC RAYS DETECTED ABOVE ENERGY OF 10¹⁹eV AT THE PIERRE AUGER OBSERVATORY AND THE TELESCOPE ARRAY

Aab, A.,Abreu, P.,Aglietta, M.,Ahn, E. J.,Al Samarai, I.,Albuquerque, I. F. M.,Allekotte, I.,Allen, J.,Allison, P.,Almela, A.,Castillo, J. Alvarez,Alvarez-Muñ,iz, J.,Batista, R. Alves,Ambrosio, IOP Publishing 2014 The Astrophysical journal Vol.794 No.2

<P>Spherical harmonic moments are well-suited for capturing anisotropy at any scale in the flux of cosmic rays. An unambiguous measurement of the full set of spherical harmonic coefficients requires full-sky coverage. This can be achieved by combining data from observatories located in both the northern and southern hemispheres. To this end, a joint analysis using data recorded at the Telescope Array and the Pierre Auger Observatory above 10(19) eV is presented in this work. The resulting multipolar expansion of the flux of cosmic rays allows us to perform a series of anisotropy searches, and in particular to report on the angular power spectrum of cosmic rays above 10(19) eV. No significant deviation from isotropic expectations is found throughout the analyses performed. Upper limits on the amplitudes of the dipole and quadrupole moments are derived as a function of the direction in the sky, varying between 7% and 13% for the dipole and between 7% and 10% for a symmetric quadrupole.</P>

Structural and dielectric properties of polyvinyl alcohol/barium zirconium titanate polymereceramic composite

T. Badapanda,V. Senthil,S. Anwar,L.S. Cavalcante,N.C. Batista,E. Longo 한국물리학회 2013 Current Applied Physics Vol.13 No.7

The polyvinyl alcohol (PVA)/barium zirconium titanate Ba[Zr0.1Ti0.9]O3 (BZT) polymereceramic composites with different volume percentage are obtained from solution mixing and hot-pressing method. Their structural and electrical properties are characterized by X-ray diffraction (XRD), Rietveld refinement,cluster modeling, scanning electron microscope and dielectric study. XRD patterns of PVA/BZT polymereceramics composite (with 50% volume fractions) indicate no obvious differences than the XRD patterns of pure BZT which shows that the crystal structure is still stable in the composite. The scanning electron micrograph indicates that the BZT ceramic is dispersed homogeneously in the polymer matrix without agglomeration. The dielectric permittivity (εr) and the dielectric loss (tan d) of the composites increase with the increase of the volume fraction of BZT ceramic. Theoretical models are employed to rationalize the dielectric behavior of the polymer composites. The dielectric properties of the composites display good stability within a wide range of temperature and frequency. The excellent dielectric properties of these polymereceramic composites indicate that the BZT/PVA composites can be a candidate for embedded capacitors.

Sugarcane Bagasse Hydrolysis Using Yeast Cellulolytic Enzymes

( Angelica Cristina De Souza ),( Fernanda Paula Carvalho ),( Cristina Ferreira Silva E Batista ),( Rosane Freitas Schwan ),( Disney Ribeiro Dias ) 한국미생물 · 생명공학회 2013 Journal of microbiology and biotechnology Vol.23 No.10

Ethanol fuel production from lignocellulosic biomass is emerging as one of the most important technologies for sustainable development. To use this biomass, it is necessary to circumvent the physical and chemical barriers presented by the cohesive combination of the main biomass components, which hinders the hydrolysis of cellulose and hemicellulose into fermentable sugars. This study evaluated the hydrolytic capacity of enzymes produced by yeasts, isolated from the soils of the Brazilian Cerrado biome (savannah) and the Amazon region, on sugarcane bagasse pre-treated with H2SO4. Among the 103 and 214 yeast isolates from the Minas Gerais Cerrado and the Amazon regions, 18 (17.47%) and 11 (5.14%) isolates, respectively, were cellulase-producing. Cryptococcus laurentii was prevalent and produced significant β- glucosidase levels, which were higher than the endo- and exoglucanase activities. In natura sugarcane bagasse was pre-treated with 2% H2SO4 for 30 min at 150oC. Subsequently, the obtained fibrous residue was subjected to hydrolysis using the Cryptococcus laurentii yeast enzyme extract for 72 h. This enzyme extract promoted the conversion of approximately 32% of the cellulose, of which 2.4% was glucose, after the enzymatic hydrolysis reaction, suggesting that C. laurentii is a good β-glucosidase producer. The results presented in this study highlight the importance of isolating microbial strains that produce enzymes of biotechnological interest, given their extensive application in biofuel production.