4,294 research outputs found
Barbosa et al. Reply to ``Comment on 'Secure Communication using mesoscopic coherent states', Barbosa et al, Phys Rev Lett 90, 227901", Yuan and Shields, Phys. Rev. Lett. 94, 048901(2005)
Yuan and Shields claim that our data-encryption protocol is entirely
equivalent to a classical stream cipher utilizing no quantum phenomena. Their
claim is, indeed, false. Yuan and Shields also claim that schemes similar to
the one presented in Phys. Rev. Lett. 90, 227901 are not suitable for key
generation. This claim is also refuted. In any event, we welcome the
opportunity to clarify the situation for a wider audience.Comment: This is the co-published Reply to the Comment made by Z.L. Yuan and
A.J. Shields published in Physical Review Letters, 94 (2005
Qualidade de Sementes de Soja BRS Candeia e BRS Tracajá Colhidas em Área de Cerrado de Roraima em Função do Tamanho.
bitstream/item/57170/1/BPD-28-2010-ID-76.pd
Doenças de fruteiras tropicais de importância quarentenária na Bahia.
Dentre os diversos segmentos agrícolas da Bahia, destaca-se o da fruticultura como aquele considerado de importÔncia econ¶mica tanto pela produþÒo de frutas para exportaþÒo como a de produþÒo familiar que, juntas, abarcam um grande contigente de trabalhadores no Estado. A Bahia destaca-se na produþÒo de frutas tropicais com ßrea plantada de aproximadamente 270 mil hectares. Produz cerca de quatro milh§es de toneladas por ano, correspondendo a 12% da produþÒo do paÝs e 47% da regiÒo Nordeste, gerando um neg¾cio de 1,4 bilh§es de reais. Dentre as frutas produzidas no Estado, destacam-se, entre outras, a produþÒo de mamÒo, citros e banana. Importantes doenþas acometem o sistema produtivo destas fruteiras no estado. Algumas delas constituem fator de risco ou limitam a exportaþÒo de nossas frutas para alguns mercados internacionais. Outras sÒo consideradas quarentenßrias e sÒo motivo de constante fiscalizaþÒo pela AgÛncia Estadual de Defesa Agropecußria da Bahia (Adab) bem como de outras importantes instituiþ§es de pesquisa e extensÒo presentes na Bahia, como a Embrapa Mandioca e Fruticultura Tropical e a Empresa Baiana de Desenvolvimento Agropecußrio (EBDA).bitstream/item/28996/1/BARBOSAID27504.pdfDisponivel em: Acesso em: 28 fev. 2011
Doenças de fruteiras tropicais na Bahia.
Dentre os diversos segmentos agrícolas da Bahia, destaca-se o da fruticultura como aquele considerado de importância econômica tanto pela produção de frutas para exportação como a de produção familiar que, juntas, abarcam um grande contigente de trabalhadores no Estado. A Bahia destaca-se na produção de frutas tropicais com área plantada de aproximadamente 270 mil hectares. Produz cerca de quatro milhões de toneladas por ano, correspondendo a 12% da produção do país e 47% da região Nordeste, gerando um negócio de 1,4 bilhões de reais. Dentre as frutas produzidas no Estado, destacam-se, entre outras, a produção de mamão, citros e banana.bitstream/item/25864/1/-www.nordesterural.com.br-nordesterural-matLer.asp-newsIdID27250.pdfDisponível em: Acesso em: 21 jan. 2010
Liquid crystal phase and waterlike anomalies in a core-softened shoulder-dumbbells system
Using molecular dynamics we investigate the thermodynamics, dynamics and
structure of 250 diatomic molecules interacting by a core-softened potential.
This system exhibits thermodynamics, dynamics and structural anomalies: a
maximum in density-temperature plane at constante pressure and maximum and
minimum points in the diffusivity and translational order parameter against
density at constant temperature. Starting with very dense systems and
decreasing density the mobility at low temperatures first increases, reach a
maximum, then decreases, reach a minimum and finally increases. In the
pressure-temperature phase diagram the line of maximum translational order
parameter is located outside the line of diffusivity extrema that is enclosing
the temperature of maximum density line. We compare our results with the
monomeric system showing that the anisotropy due to the dumbbell leads to a
much larger solid phase and to the appearance of a liquid crystal phase. the
double ranged thermodynamic and dynamic anomalies.Comment: 14 pages, 5 figure
Agroecologia: manejo de pragas e doenças de plantas.
Agroecologia é uma ciência em construção que busca modificar o curso alterado dos processos de uso e manejo dos recursos naturais, de forma a ampliar a inclusão social, reduzir os danos ambientais, fortalecer a autonomia e segurança alimentar. Sendo assim, exige dos extensionistas, agricultores e pesquisadores a modificação dos sistemas de produção que causam degradação social e ecológica. Para tanto, faz-se necessário pensar no sistema agrícola ao longo do tempo, a partir do conhecimento popular que, integrado ao conhecimento científico, poderá transformar a realidade local, melhorando, sobretudo, a qualidade de vida das pessoas
Thermochemical pre- and biological co-treatments to improve hydrolysis and methane production from poultry wastes
Poultry industry wastes, namely feathers and poultry litter, are an interesting source of substrate for biogas production. The aim of this work was to assess the biomethane potential of raw poultry
wastes, as well as the possibility of enhancing this potential by favouring the hydrolysis of cellulolytic and proteinaceous material in the wastes by using bioaugmentation and thermochemical pre-treatments. Biomethane production from poultry litter and chicken feathers was assessed in batch assays. Pre-treatment with lime and sodium hydroxide was performed at different temperatures and pressures. Clostridium cellulolyticum, C. saccharolyticum and C. thermocellum were used as bioaugmentation strains in the anaerobic digestion of poultry litter. Fervidobacterium pennivorans was used to aid the hydrolysis of poultry feather. Anaerobic digestion of the raw wastes allowed a methanisation percentage (MP) of 17±2 and 33±5%, respectively from poultry litter and chicken feathers, with 2.5% total solids. The major increase in biomethanisation of poultry litter was reached after the thermochemical pre-treatment with Ca(OH)2 (90 °C, 1.27 bar, 120 minutes), with an increase of 15% in the MP comparatively with the raw wastes MP. For the poultry feathers waste, none of the implemented strategies contributed to the optimization of methane production. However, it was observed that all treatments have contributed to a significant increase in the wastes solubilisation. Therefore, the conversion of soluble organic matter to methane was the limiting step of the anaerobic digestion process of poultry wastes
Avaliação das variações no tempo de relaxação da água em bananas durante o amadurecimento.
bitstream/CNPDIA-2010/12619/1/CiT47-2009.pd
Thermochemical pre- and biological co-treatments to improve hydrolysis and methane production from poultry litter
The biochemical methane potential (BMP) of raw poultry litter waste was assessed in batch assays. Biological co-treatment with Clostridium cellulolyticum, Caldicellulosiruptor saccharolyticum and Clostridium thermocellum as bioaugmentation strains, and thermochemical pre-treatments with lime and sodium hydroxide performed at different temperatures and pressures were applied as strategies to improve the BMP by favouring the hydrolysis of the cellulolytic material in the waste. Anaerobic digestion of the raw waste allowed a specific methane production of 145 ± 14 L CH4 kg−1 VS, with 1% total solids and 0.72 g VSinoculum g−1 VSwaste. The pre- and co-treatments contributed to a significant increase (up to 74%) in the waste solubilisation when using C. saccharolyticum, but methane production did not improve considerably. Therefore, the conversion of soluble organic matter to methane was the limiting step of the anaerobic digestion process of poultry litter waste.The authors acknowledge the financial support of the "Fundacao para a Ciencia e a Tecnologia" through the grant given to Jose Carlos Costa (SFRH/BDP/48962/2008), and to the "Fundo Europeu de Desenvolvimento Regional" through the project QREN 2008/2509. The authors would like to acknowledge Isabel Belo for the valuable help given with the high-pressure reactor used for waste physicochemical pre-treatment
- …