338 research outputs found

    Simulation of the effect of shading on monocrystalline solar module technology under hot spot condition

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    This paper focuses on the monocrystalline PV module technology subjected to operation conditions with some cells partially or fully shaded. A shaded cell under hot-spot condition operating at reverse bias are dissipating power instead of delivering power. A thermal model allows analyzing the temperature increase of the shaded cells of the module under hot-spot condition with or without protection by a bypass diode. A comparison of the simulation results for a monocrystalline PV module without shading and with partial or full shading is presented

    Regularities in football goal distributions

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    Besides of complexities concerning to football championships, it is identified some regularities in them. These regularities refer to goal distributions by goal-players and by games. In particular, the goal distribution by goal-players it well adjusted by the Zipf-Mandelbrot law, suggesting a conection with an anomalous decay.Comment: (Universidade Estadual de Maringa - Brazil) Latex, 3 pages, 3 ps figure

    Anomalous diffusion and anisotropic nonlinear Fokker-Planck equation

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    We analyse a bidimensional nonlinear Fokker-Planck equation by considering an anisotropic case, whose diffusion coefficients are DxxθD_x \propto |x|^{-\theta} and DyyγD_y \propto |y|^{-\gamma} with θ,γR\theta, \gamma \in {\cal{R}}. In this context, we also investigate two situations with the drift force F(r,t)=(kxx,kyy)\vec{F}(\vec{r},t)=(-k_{x}x, -k_y y). The first one is characterized by kx/ky=(2+γ)/(2+θ)k_x/k_y=(2+\gamma)/(2+\theta) and the second is given by kx=kk_{x}=k and ky=0k_{y}=0. In these cases, we can verify an anomalous behavior induced in different directions by the drift force applied. The found results are exact and exhibit, in terms of the qq-exponentials, functions which emerge from the Tsallis formalism. The generalization for the DD-dimensional case is discussed.Comment: 6 pages, tex fil

    Path Integral Approach to the Nonextensive Canonical Density Matrix

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    Feynman's path integral is herein generalized to the nonextensive canonical density matrix based on Tsallis entropy. This generalization is done in two ways by using unnormalized and normalized constraints. Firstly, we consider the path integral formulation with unnormalized constraints, and this generalization is worked out through two different ways, which are shown to be equivalent. These formulations with unnormalized constraints are solutions to two generalized Bloch equations proposed in this work. The first form of the generalized Bloch equation is linear, but with a temperature-dependent effective Hamiltonian; the second form is nonlinear and resembles the anomalous correlated diffusion equation (porous medium equation). Furthermore, we can extend these results to the prescription of field theory using integral representations. The second development is dedicated to analyzing the path integral formulation with normalized constraints. To illustrate the methods introduced here, we analyze the free particle case and a non-interacting scalar field. The results herein obtained are expected to be useful in the discussion of generic nonextensive contexts.Comment: (Univ. Est. de Maringa, PR- Brazil),17 pages, Late

    Effect of raw sugar cane bagasse on performance and ingestive behavior of beef cattle

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    Avaliou-se o efeito da utilização do bagaço de cana-de-açúcar in natura (BIN), obtido por dois métodos de extração do açúcar, moagem convencional ou difusão, como fonte de fibra em dietas que continham bagaço tratado sob pressão e vapor (BTPV), como principal fonte de volumoso sobre o desempenho e o comportamento ingestivo de bovinos confinados. Para avaliação do desempenho, foram utilizados 84 machos não castrados das raças Nelore, Canchim e Holandesa, com média de peso inicial de 270kg, distribuídos em delineamento de blocos ao acaso. Para a avaliação do comportamento ingestivo, foram utilizados quatro garrotes da raça Nelore, em delineamento de quadrado latino 4 x 4. Os tratamentos consistiram na substituição do BTPV pelo BIN na matéria seca, constituindo as dietas experimentais: 5% BIN moagem convencional; 5% BIN difusão, 10% BIN difusão e 15% BIN difusão. O consumo de MS foi menor no tratamento com 15% de BIN obtido por difusão (BINdif), em relação ao teor de inclusão de 10%. Não houve diferença (P>0,05) entre os tratamentos para ganho diário de peso, conversão alimentar e peso vivo final entre os tratamentos. Os tempos despendidos com as atividades de ruminação (minutos/kg de MS) e mastigação (minutos/kg de MS ou de FDN) foram maiores (P<0,05) no tratamento com 15% de BINdif na dieta. O BINdif pode ser utilizado como fonte de fibra íntegra em até 15% da MS da dieta sem prejudicar o desempenho dos animais.This study was conducted to evaluate effects of replacing steam pressure treated sugar cane bagasse by two types of raw sugar cane bagasse extracted through grinding or diffusion, on performance and ingestive behavior of beef cattle. Eighty four young bulls (Nelore, Canchim and Holstein) with 270kg of body weight at the beginning of the experiment were used in a randomized block design. Ingestive behavior was evaluated using four Nelore young bulls in a 4 x 4 Latin square design. Treatments were the direct substitution of steam pressure treated sugarcane bagasse by raw bagasse (RB), corresponding to the experimental treatments: 5% RB from grinding; 5% RB from diffusion; 10% RB from diffusion and 15% RB from diffusion. Dry matter intake was lower in treatment with 15% of bagasse obtained by diffusion (BINdif) in comparison to 10% BINdif. There were no differences (P>0.05) among treatments for average daily gain, feed conversion and final live weight. Ruminating time (minutes/kg of DM) and chewing time (minutes/kg of DM or NDF) was greater (P>0.05) when BINdif was added at 15% level to diets. BINdif can be added up to 15% of the dietary DM with no detrimental effect on beef cattle performance

    Growth, feed intake, carcass characteristics, and meat fatty acid profile of lambs fed soybean oil partially replaced by fish oil blend

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    AbstractThe objective of this study was to evaluate the effects of partial replacement of soybean oil by fish oil on dry matter intake (DMI), growth, carcass characteristics, and meat fatty acid profile of feedlot lambs. Fifty Santa Ines male lambs with 17.1±2.8 of initial body weight (BW) were individually penned and used in a randomized complete block design with 10 blocks and 5 treatments. Dietary treatments, dry matter (DM) basis, consisted of: (1) control diet (CONT) with a 10:90 of forage to concentrate ratio, (2) control diet supplemented with 40g/kg of soybean oil (0FO), (3) control diet supplemented with 2.5g/kg of fish oil blend+37.5g/kg of soybean oil (25FO), (4) control diet supplemented with 5g/kg of fish oil blend+35g/kg of soybean oil (50FO), and (5) control diet supplemented with 7.5g/kg of fish oil blend+32.5g/kg of soybean oil (75FO). Diets were mixed once daily and fed ad libitum. At the end of the 84-day feeding trial, all animals were slaughtered for carcass characteristics evaluations and meat fat acid profile determination. Animals fed soybean oil had reduced DMI compared to control; however, the average daily gain (ADG), feed efficiency (FE) and final BW were not affected. The animals fed fish oil had similar DMI, ADG, FE and final BW to those receiving the control treatment. The DMI, ADG, FE and final BW were not affected by the increasing substitution of soybean oil for fish oil. Most carcass characteristics were not affected by treatments. The shrink after chilling was lower for the 50FO diet. Short, medium, and long-chain fatty acids were similar for all diets. Stearic acid concentration was higher for lambs fed the fat diets vs. control. However, stearic acid concentration decreased linearly when fish oil replaced soybean oil. Vaccenic acid concentration was higher for lambs fed fat diets vs. control. In addition, vaccenic acid increased linearly with fish oil inclusion. The conjugated linoleic acid (CLA) C18:2 cis-9, trans-11 showed higher concentration in meat of animals fed diets containing fish oil compared to control, but it was not affected by soybean oil inclusion. Feeding small amounts of fish oil blend plus soybean oil does not exert an additional effect on the concentration of CLA C18:2 cis-9, trans-11 in relation to the exclusive use of soybean oil. However, the mixture of 7.5g/kg DM of fish oil blend with 32.5g/kg DM of soybean oil is recommended, because it improves the lipid profile of the meat by increasing the concentration of vaccenic acid, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Additionally, supplementing 7.5g/kg DM of fish oil blend mixed with 32.5g/kg DM of soybean had no negative effect on the feed intake, ADG, FE and carcass characteristics of the lambs fed high concentrate diet

    An Improved Description of the Dielectric Breakdown in Oxides Based on a Generalized Weibull distribution

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    In this work, we address modal parameter fluctuations in statistical distributions describing charge-to-breakdown (QBD)(Q_{BD}) and/or time-to-breakdown (tBD)(t_{BD}) during the dielectric breakdown regime of ultra-thin oxides, which are of high interest for the advancement of electronic technology. We reobtain a generalized Weibull distribution (qq-Weibull), which properly describes (tBD)(t_{BD}) data when oxide thickness fluctuations are present, in order to improve reliability assessment of ultra-thin oxides by time-to-breakdown (tBD)(t_{BD}) extrapolation and area scaling. The incorporation of fluctuations allows a physical interpretation of the qq-Weibull distribution in connection with the Tsallis statistics. In support to our results, we analyze tBDt_{BD} data of SiO2_2-based MOS devices obtained experimentally and theoretically through a percolation model, demonstrating an advantageous description of the dielectric breakdown by the qq-Weibull distribution.Comment: 5 pages, 3 figure

    Remarks on (1q)(1-q) expansion and factorization approximation in the Tsallis nonextensive statistical mechanics

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    The validity of (1-q) expansion and factorization approximations are analysed in the framework of Tsallis statistics. We employ exact expressions for classical independent systems (harmonic oscillators) by considering the unnormalized and normalized constrainsts. We show that these approxiamtions can not be accurate in the analysis of systems with many degrees of freedom.Comment: Latex, 6 pages, 2 figure

    Anomalous diffusion, nonlinear fractional Fokker-Planck equation and solutions

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    We obtain new exact classes of solutions for the nonlinear fractional Fokker-Planck-like equation partial_t rho = partial_x{D(x) partial^{mu -1}_x rho^{nu} - F(x) rho} by considering a diffusion coefficient D = D|x|^{-theta} (theta in R and D>0) and a drift force F = -k_1 x + k-bar_{gamma} x|x|^{gamma-1} (k_1, k-bar_{gamma}, gamma in R). Connection with nonextensive statistical mechanics based on Tsallis entropy is also discussed.Comment: latex, 5 pages. Submitted to Physica

    Dynamics of tournaments: the soccer case

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    A random walk-like model is considered to discuss statistical aspects of tournaments. The model is applied to soccer leagues with emphasis on the scores. This competitive system was computationally simulated and the results are compared with empirical data from the English, the German and the Spanish leagues and showed a good agreement with them. The present approach enabled us to characterize a diffusion where the scores are not normally distributed, having a short and asymmetric tail extending towards more positive values. We argue that this non-Gaussian behavior is related with the difference between the teams and with the asymmetry of the scores system. In addition, we compared two tournament systems: the all-play-all and the elimination tournaments.Comment: To appear in EPJ
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