956 resultados para equação de predição
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With the growth of energy consumption worldwide, conventional reservoirs, the reservoirs called "easy exploration and production" are not meeting the global energy demand. This has led many researchers to develop projects that will address these needs, companies in the oil sector has invested in techniques that helping in locating and drilling wells. One of the techniques employed in oil exploration process is the reverse time migration (RTM), in English, Reverse Time Migration, which is a method of seismic imaging that produces excellent image of the subsurface. It is algorithm based in calculation on the wave equation. RTM is considered one of the most advanced seismic imaging techniques. The economic value of the oil reserves that require RTM to be localized is very high, this means that the development of these algorithms becomes a competitive differentiator for companies seismic processing. But, it requires great computational power, that it still somehow harms its practical success. The objective of this work is to explore the implementation of this algorithm in unconventional architectures, specifically GPUs using the CUDA by making an analysis of the difficulties in developing the same, as well as the performance of the algorithm in the sequential and parallel version
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The development of oil wells drilling requires additional cares mainly if the drilling is in offshore ultra deep water with low overburden pressure gradients which cause low fracture gradients and, consequently, difficult the well drilling by the reduction of the operational window. To minimize, in the well planning phases, the difficulties faced by the drilling in those sceneries, indirect models are used to estimate fracture gradient that foresees approximate values for leakoff tests. These models generate curves of geopressures that allow detailed analysis of the pressure behavior for the whole well. Most of these models are based on the Terzaghi equation, just differentiating in the determination of the values of rock tension coefficient. This work proposes an alternative method for prediction of fracture pressure gradient based on a geometric correlation that relates the pressure gradients proportionally for a given depth and extrapolates it for the whole well depth, meaning that theses parameters vary in a fixed proportion. The model is based on the application of analytical proportion segments corresponding to the differential pressure related to the rock tension. The study shows that the proposed analytical proportion segments reaches values of fracture gradient with good agreement with those available for leakoff tests in the field area. The obtained results were compared with twelve different indirect models for fracture pressure gradient prediction based on the compacting effect. For this, a software was developed using Matlab language. The comparison was also made varying the water depth from zero (onshore wellbores) to 1500 meters. The leakoff tests are also used to compare the different methods including the one proposed in this work. The presented work gives good results for error analysis compared to other methods and, due to its simplicity, justify its possible application
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Increase hydrocarbons production is the main goal of the oilwell industry worldwide. Hydraulic fracturing is often applied to achieve this goal due to a combination of attractive aspects including easiness and low operational costs associated with fast and highly economical response. Conventional fracturing usually involves high-flowing high-pressure pumping of a viscous fluid responsible for opening the fracture in the hydrocarbon producing rock. The thickness of the fracture should be enough to assure the penetration of the particles of a solid proppant into the rock. The proppant is driven into the target formation by a carrier fluid. After pumping, all fluids are filtered through the faces of the fracture and penetrate the rock. The proppant remains in the fracture holding it open and assuring high hydraulic conductivity. The present study proposes a different approach for hydraulic fracturing. Fractures with infinity conductivity are formed and used to further improve the production of highly permeable formations as well as to produce long fractures in naturally fractured formations. Naturally open fractures with infinite conductivity are usually encountered. They can be observed in rock outcrops and core plugs, or noticed by the total loss of circulation during drilling (even with low density fluids), image profiles, pumping tests (Mini-Frac and Mini Fall Off), and injection tests below fracturing pressure, whose flow is higher than expected for radial Darcian ones. Naturally occurring fractures are kept open by randomly shaped and placed supporting points, able to hold the faces of the fracture separate even under typical closing pressures. The approach presented herein generates infinite conductivity canal held open by artificially created parallel supporting areas positioned both horizontally and vertically. The size of these areas is designed to hold the permeable zones open supported by the impermeable areas. The England & Green equation was used to theoretically prove that the fracture can be held open by such artificially created set of horizontal parallel supporting areas. To assess the benefits of fractures characterized by infinite conductivity, an overall comparison with finite conductivity fractures was carried out using a series of parameters including fracture pressure loss and dimensionless conductivity as a function of flow production, FOI folds of increase, flow production and cumulative production as a function of time, and finally plots of net present value and productivity index
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Many challenges have been presented in petroleum industry. One of them is the preventing of fluids influx during drilling and cementing. Gas migration can occur as result of pressure imbalance inside the well when well pressure becomes lower than gas zone pressure and in cementing operation this occurs during cement slurry transition period (solid to fluid). In this work it was developed a methodology to evaluate gas migration during drilling and cementing operations. It was considered gel strength concept and through experimental tests determined gas migration initial time. A mechanistic model was developed to obtain equation that evaluates bubble displacement through the fluid while it gels. Being a time-dependant behavior, dynamic rheological measurements were made to evaluate viscosity along the time. For drilling fluids analyzed it was verified that it is desirable fast and non-progressive gelation in order to reduce gas migration without affect operational window (difference between pore and fracture pressure). For cement slurries analyzed, the most appropriate is that remains fluid for more time below critical gel strength, maintaining hydrostatic pressure above gas zone pressure, and after that gels quickly, reducing gas migration. The model developed simulates previously operational conditions and allow changes in operational and fluids design to obtain a safer condition for well construction
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Neste estudo foram investigadas a diversidade, a composição, e as diferenças no uso do espaço (hábitat e microhábitat) e do alimento em uma comunidade de lagartos habitantes da serapilheira de um fragmento de Mata Atlântica, do Estado de Alagoas, Brasil. Para a observação e/ou coleta dos espécimes, foram utilizados os métodos de busca ativa e armadilhas de queda (pit-fall traps) sem cerca-guia. Para análises de diversidade e da existência de diferenças de diversidade entre os hábitats e microhábitats, utilizou-se o índice de Shannon. A largura dos nichos espacial (hábitat e microhábitat) e alimentar foi avaliada, utilizando-se o índice de diversidade de Simpson. A similaridade entre as áreas foi averiguada utilizando-se o índice de Jaccard. Para avaliar o grau de sobreposição quanto ao uso do espaço (hábitats e microhábitats) e do alimento pelas espécies, foi utilizada uma versão da equação de MarcArthur & Levis. Foram obtidas vinte e três espécies de lagartos, pertencentes a nove famílias; destas, dezenove foram obtidas no interior da mata e nove na borda. Para o interior da mata as espécies mais abundantes foram Kentropyx calcarata, Dryadosaura nordestina, Enyalius catenatus e Gymnodactylus darwinii. Na borda da mata as espécies mais abundantes foram Tropidurus hispidus, T. semitaeniatus, Ophiodes striatus e Ameiva ameiva. Quanto à utilização dos recursos, os resultados mostraram que espécies filogeneticamente próximas nem sempre utilizam de maneira semelhante os recursos disponíveis. A dieta em geral foi composta por artrópodes. Tropidurus hispidus e T. semitaeniatus se mostraram especialistas no consumo de Himenoptera (Formicidae), que estiverem presentes em 100% dos seus estômagos. Ophiodes striatus teve como principal alimento caramujos (Gastropoda) e aranhas com 60% cada; sendo Gastropoda mais abundante para esta espécie
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The relation between metabolic demand and maximal oxygen consumption during exercise have been investigated in different areas of knowledge. In the health field, the determination of maximal oxygen consumption (VO2max) is considered a method to classify the level of physical fitness or the risk of cardiocirculatory diseases. The accuracy to obtain data provides a better evaluation of functional responses and allows a reduction in the error margin at the moment of risk classification, as well as, at the moment of determination of aerobic exercise work load. In Brasil, the use of respirometry associated to ergometric test became an opition in the cardiorespiratory evaluation. This equipment allows predictions concerning the oxyredutase process, making it possible to identify physiological responses to physical effort as the respiratory threshold. This thesis focused in the development of mathematical models developed by multiple regression validated by the stepwise method, aiming to predict the VO2max based on respiratory responses to physical effort. The sample was composed of a ramdom sample of 181 healthy individuals, men and women, that were randomized to two groups: regression group and cross validation group (GV). The voluntiars were submitted to a incremental treadmill test; objetiving to determinate of the second respiratory threshold (LVII) and the Peak VO2max. Using the método forward addition method 11 models of VO2max prediction in trendmill were developded. No significative differences were found between the VO2max meansured and the predicted by models when they were compared using ANOVA One-Way and the Post Hoc test of Turkey. We concluded that the developed mathematical models allow a prediction of the VO2max of healthy young individuals based on the LVII
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O presente trabalho teve como objetivo determinar quais variáveis dimensionais da folha são mais adequadas para utilização na estimativa da área foliar do antúrio (Anthurium andraeanum), cv. Apalai, por meio de equação de regressão linear, e comparar o desempenho de diferentes funções de regressão obtidas com o uso de aprendizado de máquina (AM). A variável que melhor estimou a área foliar foi o produto das dimensões lineares (comprimento e largura), CxL, sendo a equação proposta Af = 0.9672 *C x L, com coeficiente de determinação (R²) de 0,99. Verificou-se, também, com o uso de AM, que as funções lineares são mais adequadas para a estimação da área foliar dessa espécie vegetal.
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The kinanthropometric characteristics are used by the sports science as selection criteria and detection of talents. Hence, this study aimed at comparing the anthropometrical profile, the body composition, the somatotype and the vertical jumps of the beach volleyball players. This study consists of 79 male beach volleyball players, being forty nine (n=49) Brazilian participants of the National Circuit and thirty (n=30) of 15 countries participating in the XV Pan American Games. In order to analyze the vertical jumps of the Brazilian the participants were allocated into two groups (G1 and G2) in agreement with the national ranking of their teams. The vertical jump protocol developed by Smith and collaborators was used to evaluate the vertical jumps of spike and block. The Heath-Carter anthropometrical technique (1990) was used for calculating the somatotype. The Student s t test with the Bonferroni adjustment was used to calculate the differences among the investigated variables. The multiple regression analysis was used to identify the contributions of the anthropometrical variables in the performance of the vertical jumps and the multivariance analysis was used to calculate the differences among the components of the somatotype. The Brazilian athletes of G1 were better than G2 in the spike jump (p <0.01), block jump (p <0.01) and in the block difference (p <0.01). The prediction model of the spike jump of G2 included the body mass and standing spike reach (adjusted R2 = 0.77), the body mass and the standing block reach were also included in the model of the block jump (adjusted R2 = 0.73). The regression model of G1 was not statistically significant. As for the somatotype, statistically significant differences were found between the Brazilians and the Pan Americans (Wilks' lambda = 0.498; p <0.05). The Brazilian somatotype was classified as balanced mesomorph (2.7-4.3-3.0) and the Pan American somatotype as endomorphic mesomorph (3.5-4.6-2.4). As to the specific position of the block game (2.8-4.3-2.9) and the defense game (2.6-4.4-3.0), the Brazilian somatotype was classified as balanced mesomorph and the Pan American somatotype, the block (3.7-4.4-2.4) and the defense (3.4-4.9-2.3), was classified as endomorphic mesomorph. In conclusion, the vertical jump height (spike and block) influences the male Brazilian beach volleyball players performance. The physical type of the Brazilian blockers and defenders was similar with relationship to the somatotype. The Brazilian and Pan American beach volleyball players differ in terms of kinanthropometric characteristics. This work had a multidisciplinary feature with the participation of several departments and laboratories, like the Physiotherapy Department, the Nutrition Department, the Physical Education Laboratory, thus corroborating the multidisciplinary research feature
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Among the toxic elements, Cd has received considerable attention in view of its association with a number of human health problems. The objectives of this study were to evaluate the Cd availability and accumulation in soil, transfer rate and toxicity in lettuce and rice plants grown in a Cd-contaminated Typic Hapludox. Two simultaneous greenhouse experiments with lettuce and rice test plants were conducted in a randomized complete block design with four replications. The treatments consisted of four Cd rates (CdCl2), 0.0; 1.3; 3.0 and 6.0 mg kg(-1), based on the guidelines recommended by the Environmental Agency of the State of São Paulo, Brazil (Cetesb). Higher Cd rates increased extractable Cd (using Mehlich-3, Mehlich-1 and DTPA chemical extractants) and decreased lettuce and rice dry matter yields. However, no visual toxicity symptoms were observed in plants. Mehlich-1, Mehlich-3 and DTPA extractants were effective in predicting soil Cd availability as well as the Cd concentration and accumulation in plant parts. Cadmium concentration in rice remained below the threshold for human consumption established by Brazilian legislation. on the other hand, lettuce Cd concentration in edible parts exceeded the acceptable limit.
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A síndrome dos ovários policísticos (SOP) é a desordem endócrina mais comum em mulheres com idade reprodutiva. Seu diagnóstico é firmado através do consenso de Rotterdam na presença de dois dos seguintes critérios: anovulação crônica, sinais clínicos e/ou bioquímicos de hiperandrogenismo e presença de micropolicistos nos ovários. Na SOP, além das características específicas da síndrome é comum a presença de marcadores de risco cardiovascular aumentado como dislipidemia, hipertensão arterial, resistência à insulina e obesidade central Objetivos: Analisar a acurácia diagnóstica da circunferência da cintura (CC), relação cintura-estatura (RCEst), razão cintura-quadril (RCQ) e índice de conicidade (Índice C) para detecção de fatores de risco cardiovascular (FRCV) e síndrome metabólica (SM) em mulheres com síndrome dos ovários policísticos (SOP). Metodologia: Foi realizado estudo transversal envolvendo 108 mulheres na faixa etária de 20-34 anos, com diagnóstico de SOP de acordo com o consenso de Rotterdam. Foram considerados parâmetros clínicos, antropométricos e bioquímicos de avaliação do risco cardiovascular. A análise dos dados foi desenvolvida em duas etapas, conforme descrito a seguir. Fase 1: análise da acurácia dos pontos de corte previamente determinados na literatura nacional para CC, RCEst, RCQ e Índice C, para predição de FRCV; Fase 2: determinação de pontos de corte dos índices antropométricos supracitados, específicos para mulheres com SOP, para discriminação de SM, através da análise da curva ROC (Receiver Operating Characteristic). Resultados: Com base nos achados da fase 1 do estudo, a RCEst foi o marcador que apresentou correlações positivas significativas com o xi maior número de FRCV (pressão arterial, triglicerídeos e glicemia após teste oral de tolerância à glicose), além de correlação negativa com HDL-colesterol. Os demais marcadores antropométricos se correlacionaram positivamente com pressão arterial, enquanto CC e RCQ apresentaram correlação positiva também com triglicerídeos. Todos os indicadores antropométricos apresentaram taxas de sensibilidade superiores a 60%, com destaque para a RCEst que apresentou sensibilidade superior a 70%. Na fase 2 da pesquisa observamos que a CC, RCEst e RCQ apresentaram desempenho semelhante na predição de SM, sendo superiores ao Índice C. Os valores de ponto de corte dos índices antropométricos para discriminar SM foram: CC = 95 cm; RCEst = 0,59; RCQ = 0,88; e Índice C = 1,25. Utilizando esses pontos de corte as taxas de sensibilidade e especificidade da CC e RCEst foram superiores às observadas para RCQ e Índice C. Conclusões: Nossos dados enfatizam a importância da avaliação antropométrica no rastreamento do risco cardiovascular em mulheres com SOP, destacando-se a relevância da RCEst na predição de FRCV clássicos e a necessidade de considerar pontos de corte específicos para mulheres com SOP para discriminação de SM
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Os objetivos deste trabalho foram: (1) estimar as prevalências de excesso de peso e de gordura corporal, obesidade central e pressão arterial elevada (PAE) em adolescentes beneficiários do Programa Nacional de Alimentação Escolar (PNAE) da rede municipal de ensino de Natal-RN; (2) verificar a associação entre variáveis antropométricas e de composição corporal com a pressão arterial, a maturação sexual e a história familiar positiva de fatores de risco para doença cardiovascular (FRDCV); (3) comparar dois padrões de referência para classificação do excesso de peso em adolescentes; e (4) propor equações preditivas de massa gorda (MG) e massa livre de gordura (MLG) baseadas nos perímetros corporais. Trata-se de um estudo transversal, com 526 adolescentes beneficiários do PNAE, em Natal, Brasil. O tamanho da população de estudo foi definido por amostragem aleatória, em dois estágios, e ponderada segundo número de alunos de cada escola. No primeiro estudo, o excesso de peso foi determinado por Índice de Massa Corporal (IMC), a gordura corporal estimada por dobras cutâneas e a obesidade central por perímetro abdominal. A pressão arterial elevada foi classificada conforme a American Academy of Pediatrics. As prevalências foram apresentadas em valores relativos e efeito do desenho. Realizou-se uma análise fatorial para sintetizar o conjunto de variáveis antropométricas visando identificar fatores comuns. Extraíram-se dois fatores: (1) padrão excesso de adiposidade e (2) padrão adiposidade central elevada. Para avaliar a associação entre os padrões de adiposidade corporal com pressão arterial elevada, faixa etária, maturação sexual e história familiar de FRDCV utilizou-se a Razão de Chances e respectivo intervalo de confiança de 95% e regressão logística. No segundo estudo, calculou-se a sensibilidade e a especificidade do excesso de peso classificado segundo o IOTF e a World Health Organization WHO em relação ao excesso de adiposidade corporal; e a estatística Kappa para medir a concordância entre os dois padrões de referência. No terceiro estudo, foram elaborados modelos preditivos de MG e MLG com base em nove perímetros corporais, utilizando a bioimpedância Byodinamics 450 como padrão de referência. Para tanto foram selecionados 218 adolescentes eutróficos, segundo o IMC a partir do estudo transversal. As equações foram estimadas por regressão linear múltipla, considerando a idade e os perímetros corporais. Os resultados apontaram que 14,1% dos meninos e 15,7% das meninas tinham excesso de peso; 15,3% dos meninos e 11,6% das meninas tinham excesso de gordura corporal e dentre os meninos 14,3% tinham pressão arterial elevada e as meninas, 21,4%. Todos os efeitos do desenho foram inferiores a 2,5%. Nos meninos, o padrão excesso de adiposidade foi associado à história familiar positiva de FRDCV (ORajust=2,60; 1,09-6,22), maturação sexual (ORajust=2,92; 1,04-8,22) e PAE (ORajust=3,66; 1,34-9,94). Os meninos com 12 anos e mais apresentaram 6,1 vezes mais chance de apresentar padrão adiposidade central elevada do que os adolescentes com 10 a 11 anos (IC95% 2,32-16,04), assim como os púberes apresentaram 3,2 vezes este mesmo padrão em relação aos pré-púberes (IC95%1,14-8,85). A partir da comparação entre os dois padrões de referencia de classificação do excesso de peso por meio do IMC, observou-se que a sensibilidade foi de 79,3% para o critério IOTF e de 88,9% para WHO e a especificidade foi de 94,7% e 89,9%, respectivamente. O nível de concordância foi maior para o critério IOTF (Kappa=0,70 x Kappa=0,64). Em relação à construção das equações preditivas de gordura corporal, do total de 106 meninos e 112 meninas, foram desenvolvidas duas equações para estimar MG e duas para MLG, considerando o sexo. No sexo masculino, a equação para estimar a MG incluiu as variáveis idade, punho, quadril e perímetro abdominal (R2=0,552; AIC=416,04) e MLG, idade, punho e antebraço (R2=0,869; AIC=578,24). Enquanto que no feminino, MG foi estimada pelas variáveis punho, perímetro do abdômen, do quadril, da coxa proximal e da panturrilha (R2=0,838; AIC=415,36); e a MLG por idade, punho, perímetro do abdômen, do quadril e da panturrilha (R2=0,878; AIC=512,48). Conclui-se que os adolescentes tinham elevada prevalência de excesso de adiposidade corporal e de pressão arterial elevada. Tanto o padrão excesso de adiposidade quanto adiposidade central elevada constituem-se em padrões de risco. O padrão excesso de adiposidade foi associado à pressão arterial, história familiar positiva de FRDCV e maturação sexual em meninos. O critério IOTF mostrou-se menos sensível, mais específico, com maior nível de concordância e maior probabilidade de identificar corretamente o excesso de gordura corporal nos adolescentes avaliados. Quatro equações foram desenvolvidas para a estimativa da MG e MLG em adolescentes. As equações desenvolvidas para estimar a MG no sexo feminino e MLG para ambos os sexos apresentaram valores elevados de coeficiente de determinação ajustados e, portanto, são as preferenciais. Este estudo foi realizado com a participação de equipe multidisciplinar composta por professores da área de Nutrição, Endocrinologia Pediátrica, Estatística, Educação Física, discentes do Curso de Graduação em Nutrição e residentes em Pediatria
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Visceral leishmaniasis hás adapted in the past 20 years to periurban and urban areas, and in Natal, Rio Grande do Norte, it became endemic. Thid study aimed to evaluate the environmental and social aspectsof Leishmania chagasi infection and its epidemiologic transmission chain in an urban, periurban and rural area of Parnamirim-RN. A study with three sections was conducted: Section 1: Sectional study of the human and canine infection by L. chagasi and its environmental and social determinants. Section 2: Observational longitudinal cohort to evaluate the dynamics of the canine infection. Section 3: Longitudinal study to evaluate the behavior of Lu. Longipalpis vector and the seasonal factors related to its dynamics. To include in the study the hauses were randomly selected and georreferenciated. Montenegro skin test was done in the human population and blood samples were collected for anti-Leishmania antibody detection. The canine population was examinated for L. chagasi infection by RIFI, ELISA and ELISA for rK39. An entomologic surveillance was monthly done with CDC light trapsin 10 houses of each locality. Quantitative and qualitative analyses was done using STATISC 6.0. Probality and prediction maps were done using ArcGis 9.0 model. In the human population L. chagasi infection was associated with the area of the hause, age, sex, population densyti, vegetation, kind of the floor of thr hause, water and resides destiny. In the canine population L. chagasi infection was associated with the breed, size, time of living in the hause, presence of dogs in the neighborhood, presence of horses and donkeys in the neighborhood, vegetation, kind of the floor and walls of the hause. The human infection was associated with canine infction only when analyzed taking into account the locality. In the prospective study, serum conversion and antibody lost observed in 30,8% and 22% of the animals examined, respectively. The human infection rate by L. chagasi was 24,6%, by the presence of anti-Leishmania antibody and 38,6% by the Montenegro skin test. The canine infection rate 32,5% by the presence of anti-Leishmania antibody. The vector Lu longipalpis showed an atypical behavior. These results indicate that environmental and social factors are important variables associated with L. chagasi infection in humans and canines, with punctual association of thr last two. Control measures of the infection on the studied points are necessary, in the aim to reduce the endemic focus of the disease in the study area. This research was carried out in a multidisciplinary involving the categories of: doctor, biologist, veterinarian, statistical, pharmaceutical and biochemical
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Conselho Nacional de Desenvolvimento Científico e Tecnológico
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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O trabalho foi realizado com o objetivo de determinar, pelo método fatorial, as exigências de energia metabolizável (EM) de frangos de corte. Foi conduzido um ensaio em câmaras climáticas mantidas às temperaturas de 13, 23 e 32ºC (±2ºC) para se verificar o efeito da temperatura sobre as exigências de energia metabolizável para mantença utilizando-se a técnica do abate comparativo. As exigências de energia metabolizável para ganho de peso foram determinadas com base no teor de energia corporal e na eficiência energética de utilização da EM. As exigências de mantença foram de 159,36; 116,17 e 128,66 kcal/kg0,75/dia para 13, 23 e 32ºC, respectivamente, verificando-se efeito quadrático da temperatura sobre as exigências de mantença (EMm=300,14 - 14,61.T + 0,2876.T², r²=0,90). As exigências de em para ganho de peso corporal foram de 3,72 kcal/g para machos e 3,98 kcal/g para fêmeas de 1 a 21 dias; 4,21 para machos e 3,93 para fêmeas de 22 a 42 dias; e 4,51 para machos e 7,04 para fêmeas de 43 a 56 dias. Considerando-se as exigências determinadas, foram elaborados modelos de predição das exigências diárias de energia para frangos de corte, nos quais foram considerados o peso corporal, a temperatura ambiente (para estimativa das exigências de mantença) e o ganho de peso (para cálculo das exigências de ganho). Com base nas comparações das exigências determinadas pelos modelos e nas recomendações do manual da linhagem, conclui-se que os modelos elaborados predizem as exigências energéticas dos frangos de corte.