Produção Nacional
Revisado por pares
Alan Kardek Rêgo Segundo, José Helvecio Martins, Paulo Marcos de Barros Monteiro, Rubens Alves de Oliveira, Gustavo Freitas,
The scarcity of drinking water affects various regions of the planet. Although climate change is responsible for the water availability, humanity plays an important role in preserving this precious natural resource. In case of negligence, the likely trend is to increase the demand and the depletion of water resources due to the increasing world population. This paper addresses the development, design and construction of a low cost system for measuring soil volumetric water content (θ), electrical ...
Tópico(s): Geophysical and Geoelectrical Methods
2015 - Multidisciplinary Digital Publishing Institute | Sensors
Produção Nacional
Revisado por pares
Gustavo Xavier, Delly Oliveira Filho, José Helvecio Martins, Paulo Monteiro, Antônia Sônia Alves Cardoso Diniz,
Elevated prices and lack of proper legislation and government incentives have been the main barriers in the development of the photovoltaic market in Brazil. In an attempt to overcome those barriers, a microgrid model was proposed and simulated. In the proposed microgrids, residential consumers are connected to each other to maximize the investment return by trading the surplus of generated energy among them. Different topologies and scenarios were studied from electrical energy and economic standpoints. ...
Tópico(s): Microgrid Control and Optimization
2015 - Multidisciplinary Digital Publishing Institute | Energies
Produção Nacional
Revisado por pares
Keller Sullivan Oliveira Rocha, José Helvecio Martins, Márcio Arêdes Martins, Jairo Alexander Osório Saraz, Adílio Flauzino Lacerda Filho,
If the relative humidity and temperature of the air inside a granular mass of stored grain exceeds a certain threshold value, microorganism activity is likely to increase. Lower relative humidity and temperature, when uniformly distributed inside the grain mass, prevent moisture migration and an increase in microorganism activity. To cool down or maintain the temperature of the grain mass below a threshold value, forced ventilation with an appropriate airflow can be used to remove excess moisture ...
Tópico(s): Agricultural Engineering and Mechanization
2013 - Taylor & Francis | Drying Technology
Produção Nacional
Revisado por pares
Irene Menegali, Ilda de Fátima Ferreira Tinôco, Cínara da Cunha Siqueira Carvalho, Cecília de Fátima Souza, José Helvecio Martins,
Durante o processo de criação de frangos de corte a fase inicial ou fase de aquecimento se caracteriza por ser este o período mais delicado devido à imaturidade fisiológica das aves. Desta forma, os fatores ambientais se destacam por inferir, de forma direta, no crescimento, no desempenho zootécnico e na mantança da vida desses animais. Objetivou-se, com base nessas considerações estudar, com este trabalho, o efeito de três diferentes sistemas de ventilação mínima (por pressão positiva, negativa ...
Tópico(s): Meat and Animal Product Quality
2013 - UNIVERSIDADE FEDERAL DE CAMPINA GRANDE | Revista Brasileira de Engenharia Agrícola e Ambiental
Produção Nacional
Revisado por pares
Olga Moraes Toledo, Delly Oliveira Filho, Antônia Sônia Alves Cardoso Diniz, José Helvecio Martins, María Helena Murta Vale,
The availability of reliable energy sources for all people, especially electricity, indicates an imbalance in the living conditions of a society. Therefore, new systems must be implemented to couple energy storage and renewable energy generation for the grid reliability improvement and increase access to electricity. This paper proposes a methodology to establish a general index focused on the insertion of distributed photovoltaic generation and energy storage using batteries. This methodology was ...
Tópico(s): Power System Optimization and Stability
2012 - Institute of Electrical and Electronics Engineers | IEEE Transactions on Power Systems
Produção Nacional
Revisado por pares
Claudia Valéria Távora Cabral, Delly Oliveira Filho, Antônia Sônia Alves Cardoso Diniz, José Helvecio Martins, Olga Moraes Toledo, Lauro de Vilhena Brandão Machado Neto,
Tópico(s): Solar Radiation and Photovoltaics
2010 - Elsevier BV | Solar Energy
Produção Nacional
Revisado por pares
Daniela de Carvalho Lopes, José Helvecio Martins, Adílio Flauzino Lacerda Filho, Evandro de Castro Melo, Paulo Marcos de Barros Monteiro, Daniel Marçal de Queiroz,
In this work a new control strategy for grain aeration systems was proposed. This strategy was implemented in a software package called AERO and relates four conditions which depend on real time data acquisition and on the process simulation. The main advantage of AERO controller is that it can be used in different geographic regions, during different seasons and with different aeration systems, automatically adjusting its set points. The objectives of AERO controller are to equalize the temperatures ...
Tópico(s): Food Drying and Modeling
2008 - Elsevier BV | Computers and Electronics in Agriculture
Produção Nacional
Revisado por pares
Daniela de Carvalho Lopes, José Helvecio Martins, Evandro de Castro Melo, Paulo Marcos de Barros Monteiro,
A simulation model for stored grain aeration was implemented and compared with experimental data. The software, called AERO, is capable of simulating the aeration process in stored grain, with hot spots, using time variant ambient data. Some modifications to the original model proposed by Thorpe [Thorpe, G.R., 1997. Modelling ecosystems in ventilated conical bottomed farm grain silos. Ecol. Modell. 94, 255–286] have been presented. The modified model is simpler, less computer-intensive and maintains ...
Tópico(s): Microencapsulation and Drying Processes
2006 - Elsevier BV | Postharvest Biology and Technology
Produção Nacional
Revisado por pares
Ednilton Tavares de Andrade, Paulo César Corrêa, José Helvecio Martins, Eveline Mantovani Alvarenga,
RESUMO Este trabalho foi realizado com o intuito de se avaliar danos mecânicos em sementes de feijão ( Phaseolus vulgaris L.) variedade Ouro Negro 1992, por meio de condutividade elétrica da solução contendo as sementes danificadas devido ao choque mecânico controlado, com utilização de três níveis de velocidade de choque. Para se comparar a queda de qualidade devido ao choque mecânico, foram utilizados também o teste-padrão de germinação e a avaliação visual dos danos mecânicos, cujos resultados ...
Tópico(s): Magnetic and Electromagnetic Effects
1999 - UNIVERSIDADE FEDERAL DE CAMPINA GRANDE | Revista Brasileira de Engenharia Agrícola e Ambiental
Produção Nacional
Paulo César Corrêa, José Helvecio Martins, Divair Christ,
For the drying process and safe storage of rapeseed, the experimental equilibrium moisture content and the thin layer drying curves for rapeseed (Brassica napus L.), variety Hyola-401, were determined; and the effect of drying air temperature and relative humidity on seed quality was evaluated. The equilibrium moisture content curves were obtained, both experimentally and by fitting the modified Henderson equation to the experimental data, using non-linear regression. The same procedure was used ...
Tópico(s): Advanced Control Systems Optimization
1999 - Elsevier BV | Journal of Agricultural Engineering Research
Produção Nacional
Revisado por pares
Paulo César Corrêa, Divair Christ, José Helvecio Martins, Barbara Mantovani,
RESUMO O objetivo deste trabalho foi determinar as curvas de umidade de equilíbrio higroscópico e o calor latente de vaporização para as sementes de milho pipoca (Zea mays). O teor de umidade inicial das sementes era 23% b.u. As sementes foram submetidas a dessorção, sob diversas condições de temperatura (20, 30, 40 e 50°C) e umidade relativa do ar (30, 40, 50, 60, 70, 80 e 90%) com três repetições, até atingirem a umidade de equilíbrio. A temperatura e a umidade relativa do ar foram controladas por ...
Tópico(s): Thermochemical Biomass Conversion Processes
1998 - UNIVERSIDADE FEDERAL DE CAMPINA GRANDE | Revista Brasileira de Engenharia Agrícola e Ambiental
Produção Nacional
Revisado por pares
Robinson Osorio Hernández, Lina Marcela Guerra-García, Ilda de Fátima Ferreira Tinôco, José Helvecio Martins, Cecília de Fátima Souza, Jairo Alexander Osório Saraz,
ABSTRACT This study aimed to make a simulation of the internal environment of an installations for coffee post-harvest and a parabolic solar dryer, specifically analyzing the effect of natural ventilation on the temperature and relative humidity inside these buildings. The ventilated coffee-processing plant and the solar dryer with the largest natural ventilation area showed the best results to preserve the quality of coffee grain.
Tópico(s): Building Energy and Comfort Optimization
2016 - UNIVERSIDADE FEDERAL DE CAMPINA GRANDE | Revista Brasileira de Engenharia Agrícola e Ambiental
Arienilmar A. L. da Silva, L. R. D. Faroni, R. N. C. Guedes, José Helvecio Martins, M. A. G. Pimentel,
Modelaram-se as perdas associadas à infestação de S. zeamais e R. dominica em trigo armazenado. Durante 90 dias de armazenagem, avaliaram-se a população de insetos, a umidade dos grãos, o percentual de grãos danificados por insetos, o peso hectolítrico e a perda de matéria seca da massa de grãos, em temperaturas de 16 a 36 °C. Segundo a Norma Brasileira de Classificação e Comercialização, o trigo que ultrapassar 1,5% de grãos danificados é classificado como "abaixo do padrão"e os modelos calculam ...
Tópico(s): Insect Resistance and Genetics
2003 - UNIVERSIDADE FEDERAL DE CAMPINA GRANDE | Revista Brasileira de Engenharia Agrícola e Ambiental
Produção Nacional
Revisado por pares
Solenir Ruffato, Paulo César Corrêa, José Helvecio Martins, Barbara Mantovani, Jadir Nogueira da Silva,
RESUMO Vários fatores afetam a qualidade do milho-pipoca, dentre os quais se encontram as propriedades físicas, como tamanho dos grãos e massa específica unitária e aparente e porosidade da massa granular. Para se avaliar a influência do processo de secagem sobre a massa específica e a porosidade da massa granular, teve-se por objetivo, com este trabalho, determinar as propriedades físicas para duas cultivares de milho-pipoca, em função do teor de umidade. Para obtenção dos resultados foram utilizados ...
Tópico(s): Food composition and properties
1999 - UNIVERSIDADE FEDERAL DE CAMPINA GRANDE | Revista Brasileira de Engenharia Agrícola e Ambiental
Produção Nacional
Revisado por pares
Rafael Pinheiro Amantéa, Mauri Fortes, José Helvecio Martins, Wanyr Romero Ferreira,
As a first objective, this study addresses a novel approach to drying efficiency analysis through transient models based on both the first and second laws of thermodynamics. As a second objective, we developed a numerical meshless scheme based on cubic radial basis functions to solve the associated nonlinear coupled advection-dominated set of partial differential equations. The simulated results showed excellent accuracy when compared with available literature data on drying. Finally, and most significantly, ...
Tópico(s): Heat Transfer Mechanisms
2013 - Taylor & Francis | Drying Technology
Produção Nacional
Revisado por pares
Alan Kardek Rêgo Segundo, José Helvecio Martins, Paulo Monteiro, Rrubens A. de Oliveira, Delly Oliveira Filho,
The irrigation management based on the monitoring of the soil water content allows for the minimization of the amount of water applied, making its use more efficient. Taking into account these aspects, in this work, a sensor for measuring the soil water content was developed to allow real time automation of irrigation systems. This way, problems affecting crop yielding such as irregularities in the time to turn on or turn off the pump, and excess or deficit of water can be solved. To develop the ...
Tópico(s): Irrigation Practices and Water Management
2011 - Sociedade Brasileira de Engenharia Agrícola | Engenharia Agrícola
Produção Nacional
Revisado por pares
Daniela de Carvalho Lopes, José Helvecio Martins, Antônio José Steidle Neto, Adílio Flauzino Lacerda Filho, Evandro de Castro Melo, P. M. B. Monteiro,
A simulation model was used to quantify the effect of the AERO controller on dry matter loss, moisture content, grain temperature and required aeration time for five Brazilian States during one year. The application focused on maize because it is the dominant crop in the regions studied, but the analyses can be applied to other grains and locations as well. Decision making of the AERO controller is based on simulation of the aeration process and on real time data acquisition. It proved to be an ...
Tópico(s): Crop Yield and Soil Fertility
2008 - Elsevier BV | Biosystems Engineering
Produção Nacional
Revisado por pares
Daniela de Carvalho Lopes, José Eduardo Carvalho Monte, José Helvecio Martins, Paulo Marcos de Barros Monteiro, Paulo Raimundo Pinto,
Generally, the control of thin-layer grain drying is done based on weighing the samples, periodically removing the sample from the dryer and taking it to a precision scale in order to determine, by the difference in weight, the amount of water removed from the product during the process. This operation is the main source of error in determining drying rates, due to the interruption of the drying process or the sample losses during the weighing stage. In this work, the automation of thin-layer grain ...
Tópico(s): Transport Systems and Technology
2008 - Editora da Universidade Estadual de Maringá (Eduem) | Acta Scientiarum Agronomy
Produção Nacional
Revisado por pares
S.M. Pereira, Delly Oliveira Filho, Everardo Chartuni Mantovani, Márcio Mota Ramos, José Helvecio Martins,
Teve-se como objetivo principal, neste estudo, determinar a correlação existente entre a constante dielétrica aparente e o conteúdo de água para um solo de textura argilosa e outro de textura arenosa, por meio de ajuste de modelo do tipo polinômio cúbico. Propõe-se um sistema TDR para medição da umidade do solo, formado por: osciloscópio; gerador de pulsos eletromagnéticos; cabo coaxial de 50 ômega; cabo de antena de TV; casador de impedâncias; sondas (hastes metálicas paralelas) com comprimentos ...
Tópico(s): Geophysical Methods and Applications
2006 - UNIVERSIDADE FEDERAL DE CAMPINA GRANDE | Revista Brasileira de Engenharia Agrícola e Ambiental
Produção Nacional
Revisado por pares
Gisele Tessari Santos, Mauri Fortes, José Helvecio Martins, Paulo Marcos de Barros Monteiro,
Abstract The application of irreversible thermodynamics offers a formal treatment for drying analysis that allows the evaluation of intra-particle or intra-medium temperature and moisture profiles, and enthalpy, liquid, and vapor fluxes. However, researchers have claimed that its implementation is complex. This work presents a simple methodology for modeling, solving, and validating the drying equations, as applied to wheat kernels, and for obtaining the inherent and usually unavailable transport ...
Tópico(s): Heat Transfer and Optimization
2013 - Taylor & Francis | Drying Technology
Produção Nacional
Revisado por pares
Céphora Maria Sabarense, Keller Sullivan Oliveira Rocha, Damiana Diniz Rosa, José Helvecio Martins, Marina Maria Lelis da Silva Pereira, Fabiano Ferreira da Silva, Brian L. Steward,
Liver steatosis was once believed to be a benign condition, with rare progression to chronic liver disease. Thus, in both clinical and experimental practice, it is fundamental to have a reliable and objective method for its precise quantification. An image analysis algorithm was developed and validated for automatically and rapidly quantifying hepatic fat microvesicles. The image processing algorithms automatically segmented interstitial steatosis areas and analyzed the threshold region. Automatic ...
Tópico(s): Lipid metabolism and biosynthesis
2012 - Elsevier BV | Biochemical and Biophysical Research Communications
Produção Nacional
Revisado por pares
Daniela de Carvalho Lopes, José Helvecio Martins, Paulo Marcos de Barros Monteiro, Adílio Flauzino Lacerda Filho,
Neste trabalho, estratégias de controle para aeração de grãos baseadas em temporizador, termostato e termostato combinado com umidostatos foram comparadas ao controlador AERO. Apesar de simples, as três primeiras estratégias são amplamente empregadas, resultando em controles confiáveis e em grande aceitação por parte dos produtores. O AERO foi desenvolvido na Universidade Federal de Viçosa com o objetivo de difundir e facilitar a utilização de estratégias mais sofisticadas pelos produtores. Este ...
Tópico(s): Insect Pest Control Strategies
2010 - UNIVERSIDADE FEDERAL DE VIÇOSA | Revista CERES
Produção Nacional
Revisado por pares
C. A. Teixeira, Delly Oliveira Filho, Adílio Flauzino de Lacerda Filho, José Helvecio Martins,
A falta de investimento no setor energético, aliada à sazonalidade de recursos naturais necessários para a geração de energia hidroelétrica, faz da racionalização do uso de energia elétrica uma ferramenta de apoio imprescindível para o crescimento do País. A ração animal pode representar entre 70 e 80% do custo de produção da criação de animais. Sendo assim, é importante o estudo da racionalização do uso de energia em processos que utilizam intensivamente força motriz, tais como as fábricas de ração. ...
Tópico(s): Logistics and Infrastructure Analysis
2005 - Sociedade Brasileira de Engenharia Agrícola | Engenharia Agrícola
Produção Nacional
Revisado por pares
Julian Henrique Carlotto de Andrade, José Junho Rodrigues, André Benites, Cornélio Benites, Arlindo Acosta, Marcelina Benites, Cocelina Benites, Ilda Gomes, Jaime Valdir da Silva, Eunice Antunes, Elisete Antunes, José Helvecio Martins, Daniel Martins Timóteo, Santiago Adolfo Arboleda Franco, José Cirilo Pires Morinico, Fernanda Ribeiro da Silva, Natália Hanazaki,
Experts in the Atlantic Forest, the Guarani people have the habit of transporting and exchanging plants due to their mobility throughout the territory. Historically, this habit contributed to the species composition and diversification among different phytophysiognomies that comprise the Atlantic Forest. Medicine and spirituality are traits that stand out within the Guarani culture, which is based on a holistic understanding of physical and spiritual well-being for the person's health. To achieve ...
Tópico(s): Psychedelics and Drug Studies
2021 - BioMed Central | Journal of Ethnobiology and Ethnomedicine
Produção Nacional
Revisado por pares
José Helvecio Martins, C. S. Santos, M. A. V. Silva, H. M. V. S. B. Aguiar, Itamara Gomes de França, H. G. Pereira, Diego Luiz dos Santos Ribeiro, R. M. Chaves, José Adalmir Torres de Souza, Bruno Moura Monteiro, M.F. Sá Filho, José Ribamar de Souza Torres-Júnior,
Two experiments were designed to evaluate the impact of puberty status and the administration of melengestrol acetate (MGA) before onset of the breeding period on ovulatory responses (Exp. 1) and conception rate after AI performed on estrus detection during 10 d and the pregnancy rate through 80 d of breeding period (Exp. 2) of pasture-grazed beef heifers. In Exp. 1, heifers (15 pubertal and 15 prepubertal) received 0.5 mg per heifer/d -1 of MGA over 14 d. No differences in the ovulatory responses were ...
Tópico(s): Animal Behavior and Welfare Studies
2015 - Oxford University Press | Journal of Animal Science
Produção Nacional
Revisado por pares
Gisele Tessari Santos, Mauri Fortes, Rafael Pinheiro Amantéa, Wanyr Romeo Ferreira, José Helvecio Martins,
Literature data have revealed that wheat kernel stress–strain relationships, thermal conductivity, and specific heat support the assumption of isotropy. Accepting this premise, we show that drying complexity can be reduced by properly defining the kernel shape and an accurate model. Therefore, we present an irreversible thermodynamics procedure for obtaining transport properties of a wheat kernel. The numerical solution of the associated nonlinear conservation equations was based on the Radial Basis ...
Tópico(s): Microencapsulation and Drying Processes
2017 - Taylor & Francis | Drying Technology
Arienilmar A. L. da Silva, L. R. D. Faroni, R. N. C. Guedes, José Helvecio Martins, M. A. G. Pimentel,
Para se atingir os objetivos propostos neste trabalho, desenvolveram-se modelos analíticos do crescimento populacional de S. zeamais em grãos de trigo armazenados com teor de umidade de 11,1%. O crescimento populacional foi avaliado durante 90 dias de armazenagem, nas temperaturas de 16, 20, 24, 28, 32 e 36 ºC, partindo-se de infestações iniciais que variaram de 1,3 a 9,3 insetos por kg de trigo. Os modelos explicaram de 93,9 a 98,9% da variação na densidade populacional. O crescimento populacional ...
Tópico(s): Entomopathogenic Microorganisms in Pest Control
2006 - UNIVERSIDADE FEDERAL DE CAMPINA GRANDE | Revista Brasileira de Engenharia Agrícola e Ambiental
Produção Nacional
Revisado por pares
A. Costantini, Helvécio De‐Polli, Carlos Martín Galarza, Roberto Pereyra Rossiello, Ryszard S. Romaniuk,
This study was carried out in experimental plots established at Marcos Juárez, in the Pampean Region (center of Argentina) on Typic Argiudolls, with high silt content. The aim of this work was to study the effects of two tillage systems (reduced tillage and no-tillage) on the amount of total organic C, potentially mineralizable C, C released by respiration, and C stock in the topsoil of a corn (Zea mays L.)–wheat (Triticum aestivum L.)/soybean (Glycine max L. Merr.)–soybean rotation. No-tillage showed ...
Tópico(s): Soil erosion and sediment transport
2005 - Elsevier BV | Soil and Tillage Research
Produção Nacional
Revisado por pares
Alan Kardek Rêgo Segundo, Marco J. da Silva, Gustavo Freitas, Paulo Marcos de Barros Monteiro, José Helvecio Martins,
In this article we respond to the comments made by Chavanne et al., who have questioned: (i) the name of the technique used; (ii) the ability of the system to determine both soil water content and salinity due to potential instrument biases and choice of sensor frequencies; and (iii) the procedure used to determine temperature effect on readings presented in the article "A Novel Low-Cost Instrumentation System for Measuring the Water Content and Apparent Electrical Conductivity of Soils" (Sensors 2015, ...
Tópico(s): Soil and Unsaturated Flow
2018 - Multidisciplinary Digital Publishing Institute | Sensors
Produção Nacional
Revisado por pares
Keller Sullivan Oliveira Rocha, José Helvecio Martins, Márcio Arêdes Martins, Ilda de Fátima Ferreira Tinôco, Jairo Alexander Osório Saraz, Adílio Flauzino Lacerda Filho, Luiz Henrique Martins Fernandes,
Based on the necessity for enclosure protection of temperature and relative humidity sensors installed in a hostile environment, a wind tunnel was used to quantify the time that the sensors take to reach equilibrium in the environmental conditions to which they are exposed. Two treatments were used: (1) sensors with polyvinyl chloride (PVC) enclosure protection, and (2) sensors with no enclosure protection. The primary objective of this study was to develop and validate a 3-D computational fluid dynamics ( ...
Tópico(s): Meteorological Phenomena and Simulations
2014 - Public Library of Science | PLoS ONE