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Greenhouse gas emissions and energy balance of palm oil biofuel

SOUZA, Simone Pereira de; PACCA, Sergio; AVILA, Marcio Turra de; BORGES, Jose Luiz B.
Fonte: PERGAMON-ELSEVIER SCIENCE LTD Publicador: PERGAMON-ELSEVIER SCIENCE LTD
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
66.12%
The search for alternatives to fossil fuels is boosting interest in biodiesel production. Among the crops used to produce biodiesel, palm trees stand out due to their high productivity and positive energy balance. This work assesses life cycle emissions and the energy balance of biodiesel production from palm oil in Brazil. The results are compared through a meta-analysis to previous published studies: Wood and Corley (1991) [Wood BJ, Corley RH. The energy balance of oil palm cultivation. In: PORIM intl. palm oil conference agriculture; 1991.], Malaysia; Yusoff and Hansen (2005) [Yusoff S. Hansen SB. Feasibility study of performing an life cycle assessment on crude palm oil production in Malaysia. International Journal of Life Cycle Assessment 2007;12:50-8], Malaysia; Angarita et al. (2009) [Angarita EE, Lora EE, Costa RE, Torres EA. The energy balance in the palm oil-derived methyl ester (PME) life cycle for the cases in Brazil and Colombia. Renewable Energy 2009;34:2905-13], Colombia; Pleanjai and Gheewala (2009) [Pleanjai S. Gheewala SH. Full chain energy analysis of biodiesel production from palm oil in Thailand. Applied Energy 2009;86:S209-14], Thailand; and Yee et al. (2009) [Yee KF, Tan KT, Abdullah AZ, Lee la. Life cycle assessment of palm biodiesel: revealing facts and benefits for sustainability. Applied Energy 2009;86:S189-96]...

Modelagem do balanço energético na alimentação suplementar para bovinos.; Energy balance modelling in cattle supplementary feeding.

Romanelli, Thiago Liborio
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 16/01/2003 PT
Relevância na Pesquisa
66.05%
A necessidade em se produzir alimentos para atender a demanda crescente, vem se constituindo em um dos principais problemas da humanidade. Desde o primeiro choque do petróleo, em 1973, há preocupação com o consumo de energia, devido à escassez dos recursos energéticos, que ameaça a sustentabilidade dos sistemas de produção atuais. O balanço energético é de fundamental importância para a determinação da eficiência no aproveitamento da energia de um sistema de produção agrícola sendo determinado através da quantificação dos fluxos de entrada e saída de energia no sistema. O Brasil é o segundo maior produtor mundial de carne bovina e o sexto de leite. Devido à importância econômica da pecuária no país, há uma grande preocupação com a produção de alimentação suplementar para ser fornecida aos animais durante o período seco, sendo um dos métodos mais utilizados para esse fim, a silagem de milho. Além dos métodos tradicionais de produção de alimentação suplementar como a ensilagem e a fenação, surgiram técnicas mais modernas como a silagem emurchecida, utilizada principalmente com gramíneas, que tem o seu sistema de produção muito similar ao do feno,porém apresenta menor tempo de secagem...

Evapotranspiração do capim tanzânia (Panicum maximum Jacq.) e grama batatais (Paspalum notatum flugge) utilizando o método do balanço de energia e lisímetro de pesagem.; Evapotranspiration of guinea grass (panicum maximum jacq) and bahia grass (paspalum notatum flugge) using energy balance method and weighing lysimeter.

Silva, Leonardo Duarte Batista da
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 08/04/2003 PT
Relevância na Pesquisa
66%
A irrigação de pastagens no Brasil apresentou um crescimento acentuado nos últimos anos, porém devido a ausência de pesquisas sobre a aplicação de água em pastagens, o manejo da irrigação não vem sendo realizado de maneira racional. Os objetivos deste trabalho foram avaliar as relações entre a irradiância solar global e a radiação líquida sobre superfícies vegetadas com capim tânzania (Panicum maximum Jacq.) e com grama batatais (Paspalum notatum flugge); determinar a evapotranspiração do capim tânzania, por meio das medidas de lisímetro de pesagem; aplicar o método do balanço de energia para a estimativa da evapotranspiração do capim tânzania, por meio de um sistema automático de razão de Bowen; e comparar os valores de evapotranspiração do capim tanzânia, medidos em lisímetro de pesagem com os estimados pelo balanço de energia por meio de um sistema automático de razão de Bowen. O experimento foi conduzido em Piracicaba, estado de São Paulo. Por meio de um lisímetro de pesagem e um sistema automático de razão de Bowen foram obtidos valores de evapotranspiração do capim tanzânia (ETc). Também foram obtidos dados de irradiância solar global (Qg) e radiação líquida (Rn) sobre grama batatais e capim tanzânia. Os dados foram coletados diariamente e analisados...

Modelagem do balanço de energia do dossel da cultura do pimentão em casa de vegetação.; Canopy energy balance modeling of sweet pepper cultivated in greenhouse.

Atarassi, Roberto Terumi
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 19/01/2005 PT
Relevância na Pesquisa
66.02%
Dentre os elementos em um sistema de produção em casa de vegetação, o dossel da cultura é o que mais afeta o microclima interno, sendo de grande importância o entendimento dos seus processos de troca de energia. Dada à complexidade da interação entre os vários elementos, a modelagem mostra-se como uma importante ferramenta para a pesquisa em ambientes protegidos, porém muito pouco utilizado no Brasil. O objetivo do presente trabalho foi o desenvolvimento de um modelo de simulação para estimativa dos componentes do balanço de energia do dossel da cultura do pimentão em casa de vegetação e sua calibração e teste com dados de um experimento de campo. Foi desenvolvido um modelo em equilíbrio dinâmico composto de quatro submodelos: fluxo de calor latente (λE), fluxo de calor sensível (H), balanço de ondas curtas (BOC) e balanço de ondas longas (BOL). Os submodelos para λE e H foram baseados em teorias de transferência de massa e calor por convecção mista associada a uma equação de estimativa da resistência estomática a partir de medidas climáticas. Os submodelos de BOC e BOL levaram em consideração a disposição em linhas da cultura, a cobertura parcial do dossel e o Índice de Área Foliar (IAF). O modelo foi implementado em planilha eletrônica MICROSOFT EXCEL 2000 e resolvido numericamente através de uma rotina escrita em linguagem VBA (Visual Basic para Aplicativos). O modelo foi calibrado e testado com experimento em casa de vegetação em arco com 17...

Balanço de energia e evapotranspiração de cafezal adensado em crescimento sob irrigação localizada.; Energy balance and evapotranspiration in a high density young coffee under located irrigation.

Righi, Evandro Zanini
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 28/01/2005 PT
Relevância na Pesquisa
65.97%
Foram determinadas as taxas de evapotranspiração global (ETc) e sua partição em evapotranspiração dos renques e das entrelinhas, bem como a partição da energia disponível em calores sensível e latente de um cafezal adensado (3,50m x 0,90m), irrigado por gotejamento, durante o período de 1 a 2 anos após sua implantação, em Piracicaba, SP. Foram utilizados os métodos do balanço de energia–razão de Bowen (MRB) e aerodinâmico (MA) para a determinação de ETc, o método lisimétrico para a evapotranspiração dos renques e o método do balanço de calor no caule para a transpiração a partir do fluxo de seiva. No uso do MA, foram verificados vários problemas. Um deles, é o aumento inicial pequeno do “deslocamento do plano zero” (d) normalizado pela altura da cultura, ter sido seguido por um decréscimo teoricamente inconsistente com o aumento da altura dos cafeeiros, além de uma grande variação do comprimento de rugosidade (zo), dependente das condições de cobertura das entrelinhas, da direção e da velocidade do vento, sendo evidenciado efeito dessas últimas duas variáveis também sobre d. Provavelmente, a maior fonte de erro para o MA foi terem os coeficientes de transporte turbulento, determinados com as funções empíricas do número de Richardson de estabilidade atmosférica...

Obesidade e resistência à insulina induzida pela restrição crônica no consumo de sal em ratos Wistar: efeitos sobre o balanço energético, sistema renina-angiotensina (SRA) e sinalização da insulina. ; Obesity and insulin resistance due to chronic low salt intake in Wistar rats: effects on energy balance, renin angiotensin system (RAS) and insulin signaling.

Araújo, Michella Soares Coelho
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 09/12/2005 PT
Relevância na Pesquisa
65.92%
A restrição de sal na dieta está associada com resistência à ação da insulina e obesidade. O mecanismo molecular pelo qual a dieta hipossódica (HO) pode induzir resistência à insulina e obesidade não está totalmente compreendido. O objetivo do presente estudo foi avaliar a influência da ingestão crônica de sal sobre o peso corporal (PC), sinalização da insulina no fígado, músculo e tecido adiposo branco (TAB) e sua associação com adiposidade e resistência à insulina. Com esta finalidade, ratos Wistar foram alimentados com dieta HO, normossódica (NR) ou hipersódica (HR) desde o desmame. O PC foi avaliado desde o desmame. Ao completarem 12 semanas de vida, foram avaliados pressão arterial, balanço energético, consumo de ração, glicemia, angiotensina II (ANGIO II) plasmática e perfil hormonal. A atividade motora espontânea foi estudada em ratos com 8 e 12 semanas. A sensibilidade à insulina foi analisada pelo índice de HOMA. A expressão da proteína desacopladora mitocondrial 1 (UPC-1) foi quantificada no tecido adiposo marrom (TAM) e o conteúdo de ANGIO II no TAM, TAB e hipotálamo. As etapas iniciais da sinalização da insulina foram avaliadas por imunoprecipitação e immunoblotting das proteínas envolvidas como o receptor da insulina (IR)...

Application of landsat images for quantifying the energy balance under conditions of land use changes in the semi-arid region of Brazil

Teixeira, Antônio H. de C.; Hernandez, Fernando B. T.; Lopes, Hélio L.
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Conferência ou Objeto de Conferência
ENG
Relevância na Pesquisa
65.99%
In the Nilo Coelho irrigation scheme, Brazil, the natural vegetation has been replaced by irrigated agriculture, bringing importance for the quantification of the effects on the energy exchanges between the mixed vegetated surfaces and the lower atmosphere. Landsat satellite images and agro-meteorological stations from 1992 to 2011 were used together, for modelling these exchanges. Surface albedo (α0), NDVI and surface temperature (T0) were the basic remote sensing retrieving parameters necessary to calculate the latent heat flux (λE) and the surface resistance to evapotranspiration (rs) on a large scale. The daily net radiation (Rn) was obtained from α0, air temperature (Ta) and short-wave transmissivity (τsw) throughout the slob equation, allowing the quantification of the daily sensible heat flux (H) by residual in the energy balance equation. With a threshold value for rs, it was possible to separate the energy fluxes from crops and natural vegetation. The averaged fractions of Rn partitioned as H and λE, were in average 39 and 67%, respectively. It was observed an increase of the energy used for the evapotranspiration process inside irrigated areas from 51% in 1992 to 80% in 2011, with the ratio λE/Rn presenting an increase of 3 % per year. The tools and models applied in the current research...

Nutritional recovery with rice bran did not modify energy balance and leptin and insulin levels

Martins,Maria Salete F.; Oyama,Lila M.; Latorraca,Marcia Q.; Gomes-da-Silva,Maria Helena G.; Nascimento,Claudia M. O.
Fonte: Sociedade Brasileira de Endocrinologia e Metabologia Publicador: Sociedade Brasileira de Endocrinologia e Metabologia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/03/2010 EN
Relevância na Pesquisa
66%
OBJECTIVE: To investigate the effect of nutritional recovery with rice bran on energy balance, leptin and insulin levels. METHODS: Weaned Wistar rats were fed on a 17% (Control - C) or 0.5% (Aproteic - A) protein diet for 12d. After this, rats were kept on a C diet (C) or recovered with control (Recovered Control - RC) or control plus recovered rice bran diet (Recovered Rice Bran - RRB). RESULTS: Despite the increased food intake, group A exhibited lower carcass fat associated to low serum leptin. RRB and RC groups showed lower carcass weight and energy intake and expenditure. Energy expenditure was positively associated with food intake and carcass weight. Negative correlations between HOMA-IR and energy expenditure and energy intake were observed. CONCLUSION: Nutritional recovery with rice bran did not modify energy balance, leptin and insulin levels.

Impact of irrigation on yield and energy balance of the production of oil and cake of two sunflower varieties

Jordan,Rodrigo A.; Gomes,Eder P.; Biscaro,Guilherme A.
Fonte: Associação Brasileira de Engenharia Agrícola Publicador: Associação Brasileira de Engenharia Agrícola
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/12/2012 EN
Relevância na Pesquisa
66%
The energy balance for the production of sunflower oil and cake was carried out during the agricultural and industrial stage phase, where it was considered a cold extraction by hydraulic pressing, with the plant location in a rural area with a radius of 30km range. Data on productivity was used in two varieties of sunflower (Helio 358 and Aguará 04) grown in different seasons (2007/2008, 2008/2009), under different irrigation levels. Data showed that irrigation resulted in an increase in productivity of both varieties, and the best response was observed for Aguará 04 variety. Moreover, the increased intensity of irrigation negatively affected the energy balance, reducing the ratio between energy produced and energy used in the production chain. The most significant inputs in the energy intake were fertilizer followed by diesel oil, when irrigation was not used for. When the irrigation technique was used, the most significant inputs, in order of representativeness, were: energy, fertilizer and equipment.

Energy balance in irrigated wheat in the cerrados region of Central Brazil

Luchiari Jr.,A.; Riha,S. J.; Gomide,R.L.
Fonte: São Paulo - Escola Superior de Agricultura "Luiz de Queiroz" Publicador: São Paulo - Escola Superior de Agricultura "Luiz de Queiroz"
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/06/1997 EN
Relevância na Pesquisa
65.91%
To evaluate the water requirements for irrigated wheat, a micrometeorological study was conducted during the dry seasons of 1982 and 1983 at the Cerrados Agricultural Research Center, Brasilia-DF, Brazil The crop was irrigated when the soil water potential at 5 cm rached -60 to -70J/Kg.Bowen ratio measurements were made on an hourly basis during the entire crop season. Total amount of water evapotranspired during the crop cycle and the energy balance terms varied year to year due to regional advection; In 1982, a less advective year, the total amount of water evapotranspired was 345 mm, with approximately 80% of the net radiation dissipated as latent heat, 13% as a sensible heat and 7% as soil heat after the crop obtained a Leaf Area Index (LAI) of 1.5. In 1983, when advection was greater than 1982, total water evapotranspired increased to 385 mm. The partitioning of energy was similar to 1982 during periods of little or no advection. However, during periods of intense advection, latent heat was greater hi net radiation partitioning. Although regional advection increased the water used by the crop, irrigation scheduling based on soil tensiometers was considered adequate and efficient due to the low values of the Bowen ratio obtained.

Hepatic Src Homology Phosphatase 2 Regulates Energy Balance in Mice

Nagata, Naoto; Matsuo, Kosuke; Bettaieb, Ahmed; Bakke, Jesse; Matsuo, Izumi; Graham, James; Xi, Yannan; Liu, Siming; Tomilov, Alexey; Tomilova, Natalia; Gray, Susan; Jung, Dae Young; Ramsey, Jon J.; Kim, Jason K.; Cortopassi, Gino; Havel, Peter J.; Haj, F
Fonte: Endocrine Society Publicador: Endocrine Society
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
65.98%
The Src homology 2 domain-containing protein-tyrosine phosphatase Src homology phosphatase 2 (Shp2) is a negative regulator of hepatic insulin action in mice fed regular chow. To investigate the role of hepatic Shp2 in lipid metabolism and energy balance, we determined the metabolic effects of its deletion in mice challenged with a high-fat diet (HFD). We analyzed body mass, lipid metabolism, insulin sensitivity, and glucose tolerance in liver-specific Shp2-deficient mice (referred to herein as LSHKO) and control mice fed HFD. Hepatic Shp2 protein expression is regulated by nutritional status, increasing in mice fed HFD and decreasing during fasting. LSHKO mice gained less weight and exhibited increased energy expenditure compared with control mice. In addition, hepatic Shp2 deficiency led to decreased liver steatosis, enhanced insulin-induced suppression of hepatic glucose production, and impeded the development of insulin resistance after high-fat feeding. At the molecular level, LSHKO exhibited decreased hepatic endoplasmic reticulum stress and inflammation compared with control mice. In addition, tyrosine and serine phosphorylation of total and mitochondrial signal transducer and activator of transcription 3 were enhanced in LSHKO compared with control mice. In line with this observation and the increased energy expenditure of LSHKO...

Estimativa do balanço de energia na bacia do Baixo Jaguaribe utilizando técnicas de sensoriamento remoto.; Estimate of energy balance in the basin Jaguaribe-CE using remote sensing techniques

Peixoto, Eduardo de Almeida Guimarães
Fonte: Universidade Federal de Alagoas; BR; Processos de superfície terrestre; Programa de Pós-Graduação em Meteorologia; UFAL Publicador: Universidade Federal de Alagoas; BR; Processos de superfície terrestre; Programa de Pós-Graduação em Meteorologia; UFAL
Tipo: Dissertação Formato: application/pdf
POR
Relevância na Pesquisa
66.03%
Using techniques of remote detection, this work aimed to obtain the energy balance in the Basin of Low Jaguaribe, Perimeter irrigated Tabuleiro de Russas and dam Santo Antônio de Russas. Two images of sensor TM of the satellite Landsat 5 obtained together DGI (Department of Generation of Images) of INPE, composed by six bands, (1,2,3,4,5,7) of the spectrum of the visible and a thermal band, (6) dated of 13/08/2007 and 28/09/2008, were used for this. After, I linked the variations of the obtained results, with the indexes of rain observed in four pluviometers, belonging to FUNCEME, entered in the study area. There was not rain registration during the five previous days the image of 2007, already in 2008, three pluviometers registered 14 mm, 15 mm and 3,2 mm.The processing of the images, the Software ERDAS 8.7 was used, being used for the estimate of the energy balance, the method proposed by the algorithm SEBAL (Surface Energy Balancy Algorithm Land). This algorithm calculated: reflectance, vegetation indexes, temperature of the surface, radiation balance, flow of sensitive heat, flow of latent heat among others. For the obtaining of some of those parameters was used surface data obtained in the automatic station of the municipal district of Russas. The medium reflectance...

Estimativa do balanço de energia utilizando imagens do sensor TM-Landsat 5 no baixo São Francisco; Estimation of energy balance using images form Landsat-5 TM sensor in the lower São Francisco

Santos, Fabiano Barbosa dos
Fonte: Universidade Federal de Alagoas; BR; Processos de superfície terrestre; Programa de Pós-Graduação em Meteorologia; UFAL Publicador: Universidade Federal de Alagoas; BR; Processos de superfície terrestre; Programa de Pós-Graduação em Meteorologia; UFAL
Tipo: Dissertação Formato: application/pdf
POR
Relevância na Pesquisa
66.04%
Remote sensing is a very effective way for obtaining earth surface information due to its wide area coverage and low cost. This paper aims to map and estimate the components of the Radiation Balance (Albedo, Normalized Difference Vegetation Index, Surface Temperature) and Energy Balance (Net Radiation, Soil Heat Flux, Sensible Heat Flux and Latent Heat Flux) through the sensor Thematic Mapper coupled to the Landsat-5, collected through the Instituto Nacional de Pesquisas Espaciais, combined with a digital elevation model with altitude information. The components were obtained from the Radiation and Energy Balance performed by the SEBAL/METRIC algorithm, with information obtained from two data collection platforms (Xingó-AL and Poço Redondo-SE). The covered region has an area of approximately 1342 square kilometers and includes the municipalities of Monteirópolis, Palestina, Pão de Açúcar, Piranhas and São José da Tapera, Alagoas, and the cities of Canindé do São Francisco, Poço Redondo and Porto da Folha in the state of Sergipe. The images collected corresponded to the passage of TM/Landsat-5 on said area at 9 h 30 min (Solar time) of October 17, 1999 (day 290 in the Julian calendar), October 06, 2001 (day 279 in Julian calendar) and December 7...

Hurricane disturbance and recovery of energy balance, CO2 fluxes and canopy structure in a mangrove forest of the Florida Everglades

Barr, Jordan G.; Engel, Vic; Smith, Thomas J.; Fuentes, Jose D.
Fonte: FIU Digital Commons Publicador: FIU Digital Commons
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
65.95%
Eddy covariance (EC) estimates of carbon dioxide (CO2) fluxes and energy balance are examined to investigate the functional responses of a mature mangrove forest to a disturbance generated by Hurricane Wilma on October 24, 2005 in the Florida Everglades. At the EC site, high winds from the hurricane caused nearly 100% defoliation in the upper canopy and widespread tree mortality. Soil temperatures down to -50 cm increased, and air temperature lapse rates within the forest canopy switched from statically stable to statically unstable conditions following the disturbance. Unstable conditions allowed more efficient transport of water vapor and CO2 from the surface up to the upper canopy layer. Significant increases in latent heat fluxes (LE) and nighttime net ecosystem exchange (NEE) were also observed and sensible heat fluxes (H) as a proportion of net radiation decreased significantly in response to the disturbance. Many of these impacts persisted through much of the study period through 2009. However, local albedo and MODIS (Moderate Resolution Imaging Spectro-radiometer) data (the Enhanced Vegetation Index) indicated a substantial proportion of active leaf area recovered before the EC measurements began 1 year after the storm. Observed changes in the vertical distribution and the degree of clumping in newly emerged leaves may have affected the energy balance. Direct comparisons of daytime NEE values from before the storm and after our measurements resumed did not show substantial or consistent differences that could be attributed to the disturbance. Regression analyses on seasonal time scales were required to differentiate the storm's impact on monthly average daytime NEE from the changes caused by interannual variability in other environmental drivers. The effects of the storm were apparent on annual time scales...

Energy balance and time-scales of mixing and stratification in the Jaboatão estuary, NE-Brazil

Araujo,Moacyr; Medeiros,Carmen; Ribeiro,Cesar
Fonte: Instituto Oceanográfico da Universidade de São Paulo Publicador: Instituto Oceanográfico da Universidade de São Paulo
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/1999 EN
Relevância na Pesquisa
65.92%
Estuarine systems undergo different physical processes that simultaneously control their stratification and mixing dynamics. This energy balance determines both, the estuarine hydrodynamics and the dynamics of water. This article presents a quantitative and comparative analyses between the forces maintaining stratification (surface heating; rainfall precipitation; and differential advection of the longitudinal density gradient due to the vertical velocity field) and those responsible for the vertical mixing (mechanical stirring of bottom tidal stress; mechanical stirring ofsurface wind stress; and surface evaporation) in the lower estuary ofthe Jaboatão River (JE), Pemambuco, NE-Brazil. The energy available to mix the water column at the' lower Jaboatão was 2.2 and 2.0-fold greater than that available to promote stratification, during the dry and rainy seasons, respectively. The bottom shear turbulence caused by the tides was the major source of energy for the vertical mixing. A theoretical analyses revealed that the turbulence decay time-scale io both seasons was much greater (dry=29min; rainy=25 min) than the stratification time-scale (dry=8 mio; rainy=7 min) and than the slack water time-scale (15 min). Thus the estuary was vertically well-mixed even during slack water periods during both...

Energy balance and environmental impact analysis of marine microalgal biomass production for biodiesel generation in a photobioreactor pilot plant

Sevigné Itoiz, Eva; Fuentes Grünewald, Claudio; Martínez Gasol, Carles; Garcés, E.; Alacid, E.; Rossi, Sergio; Rieradevall, Joan
Fonte: Universidade Autônoma de Barcelona Publicador: Universidade Autônoma de Barcelona
Tipo: info:eu-repo/semantics/article; info:eu-repo/semantics/acceptedVersion Formato: application/pdf
Publicado em //2012 ENG
Relevância na Pesquisa
65.99%
A life cycle assessment (LCA) and an energy balance analysis of marine microalgal biomass production were conducted to determine the environmental impacts and the critical points of production for large scale planning. The artificial lighting and temperature conditions of an indoor bubble column photobioreactor (bcPBR) were compared to the natural conditions of an equivalent outdoor system. Marine microalgae, belonging to the dinoflagellate and raphidophyte groups, were cultured and the results were compared with published LCA data obtained from green microalgae (commonly freshwater algae). Among the species tested, Alexandrium minutum was chosen as the target marine microalgae for biomass production under outdoor conditions, although there were no substantial differences between any of the marine microalgae studied. Under indoor culture conditions, the total energy input for A. minutum was 923 MJ kg¯¹ vs. 139 MJ kg¯¹ for outdoor conditions. Therefore, a greater than 85% reduction in energy requirements was achieved using natural environmental conditions, demonstrating the feasibility of outdoor culture as an alternative method of bioenergy production from marine microalgae. The growth stage was identified as the principal source of energy consumption for all microalgae tested...

Energy balance and time-scales of mixing and stratification in the Jaboatão estuary, NE-Brazil

Araujo, Moacyr; Medeiros, Carmen; Ribeiro, Cesar
Fonte: Universidade de São Paulo. Instituto Oceanográfico Publicador: Universidade de São Paulo. Instituto Oceanográfico
Tipo: info:eu-repo/semantics/article; info:eu-repo/semantics/publishedVersion; Formato: application/pdf
Publicado em 01/01/1999 ENG
Relevância na Pesquisa
65.92%
Sistemas estuarinos estão sujeitos à influência simultânea de processos fisicos que controlam tanto sua dinâmica de estratificação quanto de mistura. Este balanço energético determina seu comportamento hidrodinâmico e a dinâmica das propriedades da água. O presente artigo apresenta uma análise quantitativa e comparativa das forças de manutenção da estratificação (aquecimento superficial; precipitação pluviométrica e advecção diferencial do gradiente longitudinal da densidade devida ao campo vertical da velocidade), e daquelas responsáveis pela mistura vertical (turbulência de fimdo devido às marés; turbulência de superficie devida à ação dos ventos e evaporação superficial) no baixo estuário do Rio Jaboatão (JE), Pemambuco, NE-Brasil. A quantidade de energia disponível para misturar a coluna d'água foi 2,2 e 2 vezes maior que aquela disponível para manter a estratificação durante as estações seca e chuvosa, respectivamente. O atrito turbulento de fimdo pelas marés foi a principal fonte de energia do sistema para a mistura da coluna d'água. Uma análise teórica revelou que a escala de tempo para o decaimento turbulento nas duas estações sazonais foi superior (seca=29 min; chuvosa=25min) que a escala de tempo para estratificação (seca=8min; chuvosa=7 min) e que a escala de tempo dos estofos de maré (15 min). Assim...

Surface energy balance measurements in the México City region: a review

TEJEDA MARTÍNEZ,A.; JÁUREGUI OSTOS,E.
Fonte: Centro de Ciencias de la Atmósfera, UNAM Publicador: Centro de Ciencias de la Atmósfera, UNAM
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2005 EN
Relevância na Pesquisa
66.02%
During the last decade of the 20th Century, diverse campaigns for measuring the atmospheric energy balance were performed in downtown México City (School of Mines and Preparatory School No. 7), in the southern suburbs (University Reserve) and in the surrounding rural areas (Plan Texcoco), in addition to a campaign carried out in 1985 in the Tacubaya district, a suburban western peripheral site. The objective was to obtain data for a better understanding of the climatic alterations due to urbanization, particularly to describe the role that the modification of the natural ground cover has played as a result of paving and the construction of urban canyons. In this paper, a review of these campaigns is presented. Energy partitioning in some areas (Tacubaya and Preparatory School No.7) is similar to that observed in urban centers of middle latitudes, whereas the major contrast was observed between Texcoco, with a maximum energy consumption through evaporation, and School of Mines, where the latent heat is as low as in a desert. From the values of the correlations among the different components of energy balance, it may be possible to attempt the modeling of the diverse components of energy balance by means of regression equations starting from the net radiation. Those same coefficients distinguish the type of environment: urban...

Limitations and improvements of the energy balance closure with reference to experimental data measured over a maize field

MASSERONI,DANIELE; CORBARI,CHIARA; MANCINI,MARCO
Fonte: Centro de Ciencias de la Atmósfera, UNAM Publicador: Centro de Ciencias de la Atmósfera, UNAM
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2014 EN
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66.11%
The use of energy fluxes data to validate land surface models requires that energy balance closure conservation is satisfied, but usually this condition is not verified when the available energy is bigger than the sum of turbulent vertical fluxes. In this work, a comprehensive evaluation of energy balance closure problems is performed on a 2012 data set from Livraga obtained by a micrometeorological eddy covariance station located in a maize field in the Po Valley. Energy balance closure is calculated by statistical regression of turbulent energy fluxes and soil heat flux against available energy. Generally, the results indicate a lack of closure with a mean imbalance in the order of 20%. Storage terms are the main reason for the unclosed energy balance but also the turbulent mixing conditions play a fundamental role in reliable turbulent flux estimations. Recently introduced in literature, the energy balance problem has been studied as a scale problem. A representative source area for each flux of the energy balance has been analyzed and the closure has been performed in function of turbulent flux footprint areas. Surface heterogeneity and seasonality effects have been studied to understand the influence of canopy growth on the energy balance closure. High frequency data have been used to calculate co-spectral and ogive functions...

Diurnal evolution of anthropogenic heat released by kitchens and its relation to the energy balance at the surface in western São Paulo state, Brazil; Evolução diurna do calor antropogênico liberado por cozinhas e sua relação com o balanço de energia à superfície no Oeste Paulista, SP

Finati, Gabriela Iassia; Machado, Antonio Jaschke
Fonte: School of Civil Engineering, Architecture and Urban Design Publicador: School of Civil Engineering, Architecture and Urban Design
Tipo: info:eu-repo/semantics/article; info:eu-repo/semantics/publishedVersion; Artigo Avaliado pelos Pares; Pesquisa Empírica de Campo; Field study Formato: application/pdf
Publicado em 30/06/2015 POR
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The main goal of this work is to evaluate the anthropogenic heat from the thermal conditions in kitchens in the city of Presidente Prudente, SP, relating it to the energy balance from the building scale to the urban scale of some cities in western São Paulo State, Brazil: the regions of the cities of Presidente Prudente, Assis and Iepê. Particular attention is given to the method used to estimate the main components of energy balance at the surface, by means of estimates fluxes, as well as the characterization of the diurnal evolution of the urban canopy layer in these three cities. Although other buildings can also be analyzed in this context, kitchens were chosen because they represent environments in apparent thermal discomfort for workers who carry out their activities there, and also because in kitchens the environment conditions can be relatively controlled for the purpose of developing a methodological procedure to estimate, in a first estimate, the influence of anthropogenic heat released and the energy balance at the surface, both in inside and outside buildings. The analysis also takes into account the effect of the heat source on the state of thermal comfort. The experimental results indicate the room ventilation as an important element for the dissipation of the energy stored in the surface. Architectural design solutions are proposed to improve the thermal conditions of these environments.; Este trabalho tem como objetivo avaliar o calor antropogênico a partir das condições térmicas em cozinhas na cidade de Presidente Prudente...