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Appropriate mechanical harvesting systems for different types of olive orchards

Almeida, Arlindo
Fonte: University of Life Sciences in Lublin Publicador: University of Life Sciences in Lublin
Tipo: Conferência ou Objeto de Conferência
Português
Relevância na Pesquisa
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In the last decades olive growers spent a substantial part of their gross return to face high costs of manually cultural practices, due to shortage of manpower. Olive crop is in a critical situation due to low product price and high production costs. In order to face the problem it is mandatory to increase competitiveness on the global market, reducing costs and improving fruit quality. Low mechanization level penalizes the sector. Olive harvesting mechanization systems allow achieving these goals [Amirante, Tamborino 2012]: costs – reducing manpower needs and quality – better work rates make possible to harvest in the optimal harvest timing. For mechanical harvesting, different types of olive orchards must be considered: (a) traditional (<150 trees per hectare), (b) high density olive orchards (300 to 400 trees per hectare) and (c) hedgerow olive orchards (1000 to 2000 trees per hectare). For each olive orchard type, an appropriate harvesting system is required.

Perdas das frações de cana-de-açúcar submetida a diversos métodos de colheita; Losses in sugarcane submitted to different harvesting methods

SCHOGOR, Ana Luiza Bachmann; NUSSIO, Luiz Gustavo; MOURÃO, Gerson Barreto; MURARO, Gisele Bonato; SARTURI, Jhones Onorino; MATOS, Bruna da Conceição de
Fonte: Sociedade Brasileira de Zootecnia Publicador: Sociedade Brasileira de Zootecnia
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
37.068955%
Objetivou-se com esta pesquisa avaliar o efeito dos métodos de colheita sobre as perdas e os danos de colheita da cana-de-açúcar. As avaliações foram realizadas na variedade de cana IAC86-2480, de terceiro corte, no mês de novembro de 2006. Os métodos de colheita avaliados foram corte manual basal, corte mecanizado por meio de colhedora de forragem e corte mecanizado seguido de rebaixamento manual basal. O material colhido foi pesado e separado nas frações colmo, cana-ponta e palha. Para avaliação dos danos na touceira, foi realizada contagem do número de toletes danificados e arrancados e do número de plantas inteiras deixadas nas linhas centrais de cada parcela. O delineamento experimental foi em blocos casualizados, com três parcelas e seis repetições. A produtividade e a massa de forragem disponível foram, em média, de 80,7 e 90,3 t/ha, respectivamente. As perdas totais foram maiores no método de colheita mecanizada com rebaixamento manual, cujo valor foi de 18,5% da matéria verde colhida. Quando essas perdas foram comparadas com base na matéria seca (MS), não houve diferença entre os métodos de colheita. As perdas quantitativas e relativas das frações palha e cana-ponta foram semelhantes entre os métodos de colheita...

A preliminary characterization of the mutagenicity of atmospheric particulate matter collected during sugar cane harvesting using the Salmonella/microsome microsuspension assay

UMBUZEIRO, Gisela de Aragao; FRANCO, Alexandre; MAGALHAES, Dulce; CASTRO, Francisco Jose Viana de; KUMMROW, Fabio; RECH, Celia Maria; CARVALHO, Lilian Rothschild Franco de; VASCONCELLOS, Perola de Castro
Fonte: WILEY-LISS Publicador: WILEY-LISS
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
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During sugar cane harvesting season, which occurs from May to November of each year, the crops are burnt, cut, and transported to the mills. There are reports showing that mutagenic activity and PAH content increase during harvesting season in some areas of Sao Paulo State in comparison with nonharvesting periods. The objective of this work was to preliminarily characterize the mutagenic activity of the total organic extracts as well as corresponding organic fractions of airborne particulate matter (PM) collected twice from two cities, Araraquara (ARQ) and Piracicaba (PRB), during sugar cane harvesting season using the Salmonella/microsome microssuspension assay. One sample collected in Sao Paulo metropolitan area was also included. The mutagenicity of the total extracts ranged from 55 to 320 revertants per cubic meter without the addition of S9 and from not detected to 57 revertants per cubic meter in the presence of S9 in areas with sugar cane plantations. Of the three fractions analyzed, the most polar ones (nitro and oxy) were the most potent. A comparison of the response of TA98 with YG1041 and the increased potencies without S9 indicated that nitro compounds are causing the observed effect. More studies are necessary to verify the sources of the mutagenic activity such as burning of vegetal biomass and combustion of heavy duty vehicles used to transport the sugar cane to the mills. The Salmonella/microsome assay can be an important tool to monitor the atmosphere for mutagenicity during sugar cane harvesting season.

Effect of parametric uncertainties on the performance of a piezoelectric energy harvesting device

Godoy, Tatiane C. de; Trindade, Marcelo A.
Fonte: Associação Brasileira de Engenharia e Ciências Mecânicas - ABCM Publicador: Associação Brasileira de Engenharia e Ciências Mecânicas - ABCM
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
36.917568%
The use of piezoelectric materials for the development of electromechanical devices for the harvesting or scavenging of ambient vibrations has been extensively studied over the last decade. The energy conversion from mechanical (vibratory) to electrical energy is provided by the electromechanical coupling between mechanical strains/stresses and electric charges/voltages in the piezoelectric material. The majority of the studies found in the open literature present a tip-mass cantilever piezoelectric device tuned on the operating frequency. Although recent results show that these devices can be quite effective for harvesting small amounts of electrical energy, little has been published on the robustness of these devices or on the effect of parametric uncertainties on the energy harvested. This work focuses on a cantilever plate with bonded piezoelectric patches and a tip-mass serving as an energy harvesting device. The rectifier and storage electric circuit was replaced by a resistive circuit (R). In addition, an alternative to improve the harvesting performance by adding an inductance in series to the harvesting circuit, thus leading to a resonant circuit (RL), is considered. A coupled finite element model leading to mechanical (displacements) and electrical (charges at electrodes) degrees of freedom is considered. An analysis of the effect of parametric uncertainties of the device on the electric output is performed. Piezoelectric and dielectric constants of the piezoelectric active layers and electric circuit equivalent inductance are considered as stochastic parameters. Mean and confidence intervals of the electric output are evaluated.

Impactos da colheita de Pinus taeda sobre o balanço hídrico, a qualidade da água e a ciclagem de nutrientes em microbacias.; Impacts of the harvesting of Pinus taeda plantation on the water balance, water quality and nutrient cycling of a catchment.

Oki, Viviana Kyoko
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 07/05/2002 Português
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A busca do manejo sustentável tem promovido estudos em microbacias hidrográficas através do monitoramento das atividades florestais, procurando a melhor forma de manejo do solo, de modo a diminuir impacto ambiental e ao mesmo tempo manter a produtividade do sítio e a rentabilidade econômica. Neste contexto, com o intuito de obter informações sobre os impactos provocados pelas atividades de exploração e preparo do solo realizadas em áreas reflorestadas com Pinus taeda, o presente trabalho consiste na análise de dados do monitoramento do manejo florestal em duas microbacias adjacentes, denominadas de Microbacia Experimental da Lage e a Microbacia Experimental do Banhado, sendo esta última mantida inalterada durante o período de estudo. A evapotranspiração (ET) média para o período antes do corte foi de 1388,6mm para a microbacia da Lage e 1362,7mm para a microbacia do Banhado, representando 91% e 89% da precipitação, respectivamente. No primeiro ano após o corte, os valores médios estimados foram de: 1012,1mm, representando 77% da precipitação para a Lage e 1145,9mm (88% da precipitação) para o Banhado. No segundo ano após o corte a ET da microbacia da Lage manteve-se no patamar de 78% da precipitação. A maior parte da biomassa presente na microbacia estava contida no lenho...

Avaliação nutricional da cana-de-açúcar submetida a métodos de colheita para produção animal; Nutritional evaluation of sugarcane (Saccharum ssp.) submitted to harvesting methods for animal production

Thiago, Rodrigo Dener Ribeiro Tabone
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 05/10/2009 Português
Relevância na Pesquisa
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O objetivo desta pesquisa foi estudar a composição químico-bromatológica sobre a variedade de cana-de-açúcar IAC86-2480 submetida a três métodos de colheita. Os tratamentos corresponderam a três métodos de colheita: colheita manual (MAN), colheita mecanizada (MEC) e colheita mecanizada seguido de rebaixamento manual (MEC+MAN). O tratamento relativo ao corte manual foi efetuado na região do colo da planta, rente ao solo, com uso de podão.No caso do corte mecanizado, foi utilizada uma colhedora de forragem regulada para altura de corte de 20 cm. O terceiro tratamento foi aquele em que as plantas foram submetidas ao procedimento de corte mecanizado, e na seqüência, a porção remanescente do colmo (toco) foi cortada rente ao solo com o uso de podão. A área experimental (0,34 ha) foi constituída por seis blocos, com 3 parcelas cada. As parcelas eram formadas por 8 linhas de plantio com 15 m de comprimento em espaçamento entrelinhas de 1,3 m. Os perfilhos eram então separados em 3 frações: colmo, folha e planta inteira. Para a determinação da composição químico-bromatológica (PB, FDN, FDA, DVIVMS e MM) utilizou-se o método de espectroscopia de reflectância de infravermelho proximal (NIRS). O Brix foi determinado em refratômetro digital e a Pol a partir da leitura sacarimétrica do caldo. O Brix...

Desenvolvimento da cana-de-açúcar (Saccharum spp.) sob diferentes formas de colheita e de manejo do palhiço.; Development of sugarcane (Saccharum spp.) under different forms of harvesting and of straw management

Leme Filho, José Rubens Almeida
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 29/01/2010 Português
Relevância na Pesquisa
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Da substituição da colheita manual de cana queimada pela mecanizada de cana crua, decorre grande demanda por pesquisas relacionadas aos efeitos do palhiço, residual da colheita, sobre a cana soca e sobre o ambiente de produção. O presente trabalho teve por objetivo estudar os efeitos do sistema de colheita e do manejo do palhiço residual sobre o desenvolvimento das soqueiras de cana-de-açúcar e sobre algumas propriedades físicas e químicas do solo. O experimento foi instalado em área de colheita mecanizada de cana-de-açúcar, variedade SP91- 1049, conduzido ao longo do ciclo da primeira soca, delineado em blocos completos casualizados, com quatro repetições e os seguintes quatro tratamentos: palhiço em área total (não manejado); remoção do palhiço de sobre as linhas de cana (desaleiramento); palhiço aleirado; e palhiço queimado. Uma medida mensal de temperatura do solo foi feita até o 9º mês após o corte. A biometria foi feita mensalmente até 8 meses após o corte, avaliando-se o perfilhamento da cana e o crescimento inicial da parte aérea. Próximo ao final do ciclo foram feitas análises químicas de solo e de folhas de cana, análises físicas de solo não deformado, avaliação da distribuição da umidade e do sistema radicular no perfil do solo...

Alternativas de colheita de Eucalyptus e seus impactos no solo e na vegetação nativa em processo de regeneração num plantio abandonado; ALTERNATIVES OF EUCALYPTUS HARVESTING SYSTEMS AND THEIR IMPACTS ON SOIL AND NATIVE VEGETATION OF ABANDONED STANDS

Mendes, João Carlos Teixeira
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 09/11/2012 Português
Relevância na Pesquisa
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Essa pesquisa avaliou os efeitos de três sistemas de colheita de madeira sobre os atributos físicos do solo e estruturais da vegetação nativa do sub-bosque, num talhão de Eucalyptus saligna Smith. abandonado há 40 anos. A área experimental se encontra na Estação Experimental de Ciências Florestais da ESALQ-USP, no município de Itatinga/SP. O delineamento experimental aplicado foi de blocos ao acaso, com nove parcelas e três repetições, devido à constatação no sítio de heterogeneidade espacial da densidade de eucalipto e da vegetação nativa. Foram testados três tratamentos: CCV - colheita convencional com extração mecanizada; CIR1 - colheita de impacto reduzido com extração mecanizada; e CIR2 - colheita de impacto reduzido com associação de extração animal para lenha (DAP 30 cm) e com extração mecanizada para tora (DAP > 30 cm). As medições de densidade, resistência à penetração e distúrbios na superfície do solo, e danos na vegetação do sub-bosque, foram realizadas em duas etapas, após a extração de lenha e após a extração de tora. As variáveis para o estudo dos efeitos no solo foram: quatro classes de distúrbios superficiais (m2.ha-1): sem dano, leve, moderado e severo; resistência à penetração (MPa); e densidade aparente (g.cm-3). Os resultados evidenciaram a ocorrência de valores acima do nível crítico teórico para resistência à penetração e densidade...

Population structure of pond-raised Macrobrachium amazonicum with different stocking and harvesting strategies

Preto, Bruno L.; Kimpara, Janaina M.; Moraes-Valenti, Patricia; Valenti, Wagner Cotroni
Fonte: Elsevier B.V. Publicador: Elsevier B.V.
Tipo: Artigo de Revista Científica Formato: 206-211
Português
Relevância na Pesquisa
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP); Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq); Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES); The effect of size-grading of juveniles prior to stocking, as well as selective harvesting, on the population structure of pond-raised Macrobrachium amazonicum was studied. A randomized-complete-blocks design with 4 treatments and 3 replicates was used. The treatments were: upper size-graded juveniles, lower size-graded juveniles, ungraded juveniles (traditional), and ungraded juveniles with selective harvesting. Twelve 0.01 ha earthen ponds were stocked at 40 juveniles m(-2), according to the relevant treatment. Every three weeks, random samples from each pond were obtained for biometry, and after 3.5 months, the ponds were drained and completely harvested. Animals were then counted, weighed, and sexed; males were sorted as Translucent Claw (TC), Cinnamon Claw (CC), Green Claw 1 (GC1), and Green Claw 2 (GC2), and females as Virgin (VF), Berried (BE), and Open (OF). The prawns developed rapidly in the ponds. attaining maturity and differentiating into male morphotypes after about 2 months in all treatments. The fast-growing juveniles (upper grading fraction) mostly did not constitute the dominant males (CC] and GC2) in the adult population. Population development was slower in ponds stocked with Lower prawns...

Rainwater harvesting case study: FCT/UNL campus

Quadros, Carlos Schmidt
Fonte: Faculdade de Ciências e Tecnologia Publicador: Faculdade de Ciências e Tecnologia
Tipo: Dissertação de Mestrado
Publicado em //2010 Português
Relevância na Pesquisa
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Dissertação apresentada para a obtenção do grau de Mestre em Engenharia do Ambiente, Perfil Engenharia Sanitária; With increasing pressure on the environment, particularly on water resources, due to outside forces such as climate change and population growth, water is nowadays a scarce and a valuable resource. With the need to find new alternatives, rainwater harvesting should be seen as an important strategy for better management of water resources, once it constitutes a free source of potable water. Rainwater harvesting systems, which already have a global implementation, are a recognised way for urban buildings to reduce their reliance on the public mains supply. Its applications are predominantly non-potable, namely toilet flushing and gardening. The aim of this report is to produce a comprehensive assessment of rainwater harvesting and its potential use all over the world, as well as the potential economical and environmental benefits. It is provided a description of all the rainwater harvesting system components, as well as water quality requirements according to the water final purpose. A case study is presented, which main object is to evaluate the feasibility of rainwater harvesting for gardening, applied to the University Campus of the Faculty of Sciences and Technology of Universidade Nova...

Effect of parametric uncertainties on the performance of a piezoelectric energy harvesting device

Godoy,Tatiane C. de; Trindade,Marcelo A.
Fonte: Associação Brasileira de Engenharia e Ciências Mecânicas - ABCM Publicador: Associação Brasileira de Engenharia e Ciências Mecânicas - ABCM
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2012 Português
Relevância na Pesquisa
36.917568%
The use of piezoelectric materials for the development of electromechanical devices for the harvesting or scavenging of ambient vibrations has been extensively studied over the last decade. The energy conversion from mechanical (vibratory) to electrical energy is provided by the electromechanical coupling between mechanical strains/stresses and electric charges/voltages in the piezoelectric material. The majority of the studies found in the open literature present a tip-mass cantilever piezoelectric device tuned on the operating frequency. Although recent results show that these devices can be quite effective for harvesting small amounts of electrical energy, little has been published on the robustness of these devices or on the effect of parametric uncertainties on the energy harvested. This work focuses on a cantilever plate with bonded piezoelectric patches and a tip-mass serving as an energy harvesting device. The rectifier and storage electric circuit was replaced by a resistive circuit (R). In addition, an alternative to improve the harvesting performance by adding an inductance in series to the harvesting circuit, thus leading to a resonant circuit (RL), is considered. A coupled finite element model leading to mechanical (displacements) and electrical (charges at electrodes) degrees of freedom is considered. An analysis of the effect of parametric uncertainties of the device on the electric output is performed. Piezoelectric and dielectric constants of the piezoelectric active layers and electric circuit equivalent inductance are considered as stochastic parameters. Mean and confidence intervals of the electric output are evaluated.

Analysis of the coffee harvesting process using an electromagnetic shaker

Santos,Fábio Lúcio; Queiroz,Daniel Marçal de; Pinto,Francisco de Assis de Carvalho; Santos,Nerilson Terra
Fonte: Editora da Universidade Estadual de Maringá - EDUEM Publicador: Editora da Universidade Estadual de Maringá - EDUEM
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/09/2010 Português
Relevância na Pesquisa
37.00562%
Harvesting is one of the most important operations in coffee production systems. This operation has a high cost and impact on the final quality of the product. To reduce production costs, producers are looking for ways to mechanize this operation. Harvesting machines generally detach fruits from the coffee plant by vibration and/or impact. The objective of this work was to study the effect of the amplitude and frequency of vibration on the efficiency of coffee fruit harvesting. Vibration tests of coffee branches were performed in a laboratory using an electromagnetic shaker. The tests were performed using amplitudes in the range of 3.75 to 7.50 mm and frequencies from 13.33 to 26.67 Hz. Coffee branches from two different varieties were used for evaluation, Catuaí Vermelho and Mundo Novo. It was verified that harvesting efficiency is directly related to the acceleration reached by the fruits during the harvesting process. The frequencies of 23.33 and 26.67 Hz and amplitudes of 6.25 and 7.50 mm resulted in the highest harvesting efficiency of ripe coffee cherries for both varieties. However, the harvesting efficiency for the Mundo Novo variety was higher than that of the Catuaí Vermelho variety at the studied frequency and amplitude ranges in this work.

Endoscopic harvesting of autogenous fascia lata

Malhotra, R.; Selva-Nayagam, D.; Olver, J.
Fonte: Lippincott Williams & Wilkins Publicador: Lippincott Williams & Wilkins
Tipo: Artigo de Revista Científica
Publicado em //2007 Português
Relevância na Pesquisa
36.9533%
PURPOSE: To describe a technique of endoscopic harvesting of autogenous fascia lata. METHODS: A retrospective, noncomparative clinical study to evaluate the technique of videoendoscope assistance in harvesting autogenous fascia lata was conducted during a 1-year period in 2002. A small incision approximately 2 cm long is made over the lateral aspect of the thigh, either as a low or high approach. A sheathed 4-mm rigid 0- or 30-degree endoscope is used to visualize the length of the fascia lata along both its superficial aspect and its undersurface. Standard endoscopic brow lifting instruments are then used to dissect a length of fascia under direct visualization. RESULTS: Three patients underwent harvesting of autogenous fascia lata under endoscopic visualization (2 high-thigh and 1 low-thigh technique). Adequate lengths of fascia lata, approximately 12 cm long, were harvested and no complications occurred. The endoscope was particularly useful in identifying the anatomical structures adjacent to the fascia. The technique was easy to use, but took twice as long as traditional harvesting techniques. CONCLUSIONS: Videoendoscopy allows complete visualization of anatomical structures during harvesting of autogenous fascia lata. It highlights the anatomy for teaching and provides an alternative approach to conventional harvesting methods.; Malhotra...

Physical characteristics of Pleurochrysis carterae in relation to harvesting potential for biodiesel production.

Rahbari, Marjan
Fonte: Universidade de Adelaide Publicador: Universidade de Adelaide
Tipo: Tese de Doutorado
Publicado em //2009 Português
Relevância na Pesquisa
36.9533%
During the last three decades, microalgae has been suggested as a potential source of biofuel, with a number of advantages over other energy crops. These advantages, including high lipid content, fast growth rate, reduced requirements for land and the possibility of utilizing marine water systems constitute the most likely sources for CO2 reduction systems. However, no commercial plant has been established to date. This is because of the high capital cost of microalgal systems and the many uncertain aspects of harvesting small cells (<20μm) from dilute cultures (~1g/l). Therefore, this project aims to investigate the physical characteristics of Pleurochrysis carterae, a potential biofuel feedstock, with a view to understanding the fundamental characteristics of this species during large-scale harvesting. The preliminary study of cell growth cycle in the laboratory showed that; P. carterae grows quickly in BG11 media with 1.8% salinity. The maximum cell concentration after 20 days was ~0.5 g/l. Also, large flocs (120μm) were observed early in the growth phase (day 4) and the stationary phase (day20). In order to calculate the theoretical settling rate some parameters, such as cell size distribution and medium viscosity, were measured. The results indicated that cell size grew from 3.8μm at the inoculation to 11.7 μm at the end of the growth cycle. Also...

Culturing and harvesting marine microalgae for the large-scale production of biodiesel.

Sathe, Suraj
Fonte: Universidade de Adelaide Publicador: Universidade de Adelaide
Tipo: Tese de Doutorado
Publicado em //2010 Português
Relevância na Pesquisa
36.9533%
In the commercial production of biodiesel from marine microalgae, the cost and efficiency of harvesting technique affects the overall cost and production of biodiesel. The commercial harvesting techniques being used for harvesting microalgae include centrifugation and filtration preceded by flocculation. Centrifugation and filtration are very high cost processes and different flocculation techniques like chemical flocculation, auto-flocculation and bio-flocculation (microbial flocculation) are being developed to achieve more efficiency in flocculation of algal biomass at lower costs. In this project, ‘Electroflocculation’- a common process for flocculating contaminants, organic matter and metal ions from waste water was applied to flocculate marine microalgae. The studies presented in the thesis aim to 1. determine the effect of electroflocculation on the flocculation of marine microalgae at lab scale 2. investigate the factors affecting electroflocculation i.e. current density, time, material of electrodes, distance between electrodes, salinity of the cultures and pH 3. scale-up the lab scale electroflocculation process to pilot-scale and investigate the cost effectiveness of pilot-scale electroflocculation process 4. theoretically optimize...

The renaissance of an ancient technique: rain water harvesting potentials in the lower Jordan River Basin (Briefing 2.10)

Gunkel, Anne; Lange, Jens
Fonte: Universidade de Tubinga Publicador: Universidade de Tubinga
Tipo: Sonstiges
Português
Relevância na Pesquisa
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Two thousand years ago, the Nabateans used rainwater harvesting (RWH) for water supply. They collected water for domestic purposes (urban RWH) and used surface runoff for agriculture (rural RWH). Both types of RWH have ained interest among modern-day water resources planners seeking methods to alleviate present-day water scarcity in the Lower Jordan River Basin (LJRB). Results showed that urban and rural rainwater harvesting offers significant potential for contributing to decentralized water supply in the Lower Jordan River Basin. The degree to which water resources accessed via rainwater harvesting can contribute to the region’s overall water supply is dramatically reduced during drought periods. When incorporating rainwater harvesting into a water management strategy, downstream impacts and the high temporal variability of available water must be considered. Due to population growth and increasing urbanization of land in the Lower Jordan River Basin, opportunities for urban rainwater harvesting will increase.

Influência da época de plantio e corte na produtividade da cana-de-açúcar.; Influence of planting and harvesting season on sugarcane productivity.

Marchiori, Luís Fernando Sanglade
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 05/10/2004 Português
Relevância na Pesquisa
36.9533%
O planejamento de colheita na cultura da cana-de-açúcar busca otimizar o retorno econômico, baseado no conceito de que a cana tem uma época, durante o ano, onde ocorre máxima concentração de sacarose nos colmos. Realizaram-se neste trabalho estudos enfocando as influências dos fatores edafo-climáticos sobre o rendimento e açúcares totais recuperáveis. Foram testadas as hipóteses de que há interação entre as épocas de plantio e corte, bem como a hipótese de que há interação do tratamento muda inteira e picada com cada época de plantio. Utilizaram-se dados de pesquisa conduzida, no Campo de experimentação da COPERSUCAR – Piracicaba/SP, num solo Latossol Vermelho Eutrófico. O delineamento utilizado foi blocos ao acaso, com parcelas subdivididas em faixas e sub-subparcelas dentro das faixas. Os tratamentos foram épocas de plantio (Novembro, Janeiro, Março, Maio), as faixas foram épocas de corte (Maio, julho, Setembro, Novembro), e os sub-subtratamentos foram mudas picada e inteira. Mediram-se as variáveis: toneladas de colmos (TCH) e toneladas de açúcar por hectare (TAH), e açúcar total recuperável (ATR). A soqueira foi avaliada da mesma forma que o 1º corte, aos (12) meses de idade. Foram instalados três experimentos...

Dynamics of Electromagnetic Systems for Energy Harvesting and Filtering

Owens, Benjamin Andrew Michael
Fonte: Universidade Duke Publicador: Universidade Duke
Tipo: Dissertação
Publicado em //2014 Português
Relevância na Pesquisa
36.917568%

The focus of this dissertation is on the dynamics of electromagnetic systems for energy harvesting and filtering applications. The inclusion of magnets into systems generates nonlinearity due to the nature of electromagnetic interactions. In this work, magnetic nonlinearity manifests in tip interactions for cantilever beams, coupling effects for electromagnetic transduction, and bistable potential wells for a two beam system. These electromagnetic interactions are used to add non-contact coupling effects for the creation of bistable oscillators or arrays of coupled beams for energy filtering.

Nonlinearity at the tip of cantilever beams acts to change the dynamic and static behavior of the system. In this dissertation, these interactions are analyzed both with and without the nonlinear tip interactions. A linear analysis of the system without the tip interaction first provides insight into the shifting frequencies of the first four natural oscillation modes when considering a rigid body tip mass with rotational inertia and a center of mass that is offset from the tip of the beam. Then, the characterization of the nonlinearities in the beam stiffness and magnetic interaction provide insight into the static and dynamic behavior of the beam. The analytical and numerical investigations...

A Cost-Benefit Analysis of Rainwater Harvesting

Hicks, William D
Fonte: Universidade Duke Publicador: Universidade Duke
Tipo: Masters' project Formato: 409392 bytes; application/pdf
Português
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Rainwater harvesting has provided a water source for communities around the world dating back to circa 1500 B.C. This ancient technology continues to serve populations today, mainly in poor, rural or dry regions of the world and island communities. Contemporary green building and stormwater management programs (e.g., Leadership in Energy and Environmental Design – LEED, Low Impact Development – LID, Better Site Design) suggest that rainwater harvesting can serve as a valuable stormwater management tool even in areas where municipal water supplies are readily available. Regardless, private developers are most apt to incorporate these systems into commercial development designs if the benefits justify the costs. Analyses of local rainfall data and predicted potential water usage at commercial facilities in Arlington County, Virginia reveal that rainwater harvesting systems conserve potable water, protect surface water quality and minimize flood risk. However, economic analyses from the perspective of a private developer using two case studies of commercial developments in Arlington suggest that the benefits of incorporating rainwater harvesting into building designs do not justify the cost of implementing this technique. Notwithstanding...

Autologous intramedullary bone graft harvesting as an alternative to conventional harvesting methods

Sprong,Francois; Snyckers,Christian Hugo; Birkholtz,Franz Friedrich
Fonte: SA Orthopaedic Journal Publicador: SA Orthopaedic Journal
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2011 Português
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Conventional bone graft harvesting using the iliac crest is often cited as having significant donor site morbidity and complications. A technique has become available in the form of intramedullary harvesting, using a reamerirrigationaspiration (RIA) system. It is hailed as a safe alternative, with minimal donor site morbidity and pain. This study presents a retrospective case series of 16 patients where the RIA system was used as a harvesting technique from June 2008 to January 2010. This technique involves harvesting autograft from the femoral canal (anterograde or retrograde) by reaming the intramedullary cavity only once. A single surgeon performed the operations over a 24month period. Fluoroscopy was used to size and measure the width of the canal and to confirm guide wire placement. Outcomes evaluated were postoperative pain perception and patient satisfaction. Bone harvest volumes, intraand postoperative complications and bony union were noted. Telephonic interviews were conducted in all 16 cases. The average age of the patients was 31 years (15-55 years). The femoral canal was used as the donor site in all the patients. The mean postoperative followup period was 18.8 months (8-27 months). The average amount of bone harvested was 39.6 cc (20-70 cc). Two technical complications were encountered intraoperatively and there were no systemic complications due to reaming. Although The RIA system was found to be a safe technique...