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| Registros recuperados: 30 | |
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| Donval, Jean-pierre; Guyader, Vivien. |
| “Headspace” technique is one of the methods for the onboard measurement of hydrogen (H2) and methane (CH4) in deep seawater. Based on the principle of an automatic headspace commercial sampler, a specific device has been developed to automatically inject gas samples from 300 ml syringes (gas phase in equilibrium with seawater). As valves, micro pump, oven and detector are independent, a gas chromatograph is not necessary allowing a reduction of the weight and dimensions of the analytical system. The different steps from seawater sampling to gas injection are described. Accuracy of the method is checked by a comparison with the “purge and trap” technique. The detection limit is estimated to 0.3 nM for hydrogen and 0.1 nM for methane which is close to the... |
| Tipo: Text |
Palavras-chave: Gas; Seawater; Headspace method. |
| Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00354/46523/46287.pdf |
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| Donval, Jean-pierre; Charlou, Jean-luc; Lucas, L.. |
| Headspace technique is a common method to analyze light hydrocarbons in deep marine sediments. The use of an automatic headspace sampler instead of a manual injection is the guarantee for a better repeatability and furthermore it is less time consuming. But to increase the sensitivity and therefore, to achieve a better detection limit, it is necessary to optimize the automatic headspace sampler parameters. The theory of design of experiments was applied here by studying them. As a response, methane, which is an important gas in marine sediments, was chosen for its short analysis time. Regarding the parameters for automatic headspace sampler, eight variables were selected and then, a screening of them was carried out with a fractional factorial design to... |
| Tipo: Text |
Palavras-chave: Design of experiments; Headspace technique; Gas; Sediments. |
| Ano: 2008 |
URL: http://archimer.ifremer.fr/doc/2008/publication-6235.pdf |
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| MAURICIO, R.M.; PEREIRA, L.G.R.; GONCALVES, L.C.; TOMICH, T.R.; RODRIGUES, J. A. S.; RODRIGUEZ, N.M.; PIRES, D.A. de A.; JAYME, C.G.. |
| Para que o girassol possa ser utilizado com sucesso na forma de silagem, é necessario que se determine o ponto ideal de ensilagem. O objetivo desse experimento foi avaliar atraves da tecnica de producao de gases Reading Pressure Technique as silagens do hibrido M734 ensilado com 30, 37, 44 e 51 dias apos a floracao. O liquido ruminal foi obtido de tres carneiros machos fistulados. As leituras de pressao dos gases foi feita atraves de um transdutor de pressao as 2, 4, 6, 8, 10, 12, 15, 19, 24, 30, 36, 48, 72, 96 h apos incubacao. O volume de gas produzido foi estimado por uma equacao de regressao entre pressao e volume. A cinetica ruminal foi descrita matematicamente atraves dos parametros potencial maximo de producao de gases, lag phase, taxa de producao... |
| Tipo: Artigo em anais de congresso (ALICE) |
Palavras-chave: Girassol; Silagem; Epoca; Valor nutritivo; Ruminantes; Cinetica; Degradacao; Gas; Producao. |
| Ano: 2002 |
URL: http://www.alice.cnptia.embrapa.br/handle/doc/485870 |
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| Franken, Jason R.V.; Parcell, Joseph L.. |
| Increased use of alternative fuels and low commodity prices have contributed to the recent expansion of the U.S. ethanol industry. As with any competitive industry, some level of output price risk exists in the form of volatility; yet, no actively traded ethanol futures market exists to mitigate output price risk. This study reports estimated minimum variance cross-hedge ratios between Detroit spot cash ethanol and the New York Mercantile Exchange unleaded gasoline futures for 1-, 4-, 8-, 12-, 16-, 20-, 24-, and 28-week hedge horizons. The research suggests that a one-to-one cross-hedge ratio is not appropriate for some horizons. |
| Tipo: Journal Article |
Palavras-chave: Cross-hedging; Ethanol; Gas; G13; Q13; Q42. |
| Ano: 2003 |
URL: http://purl.umn.edu/43152 |
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| GONCALVES, R.A.; SANTOS, J.P.; CHANDRA, P.K.; GERMANI, R.. |
| A utilizacao de gases inertes como fumigantes no controle de pragas e uma alternativa ao uso de fosfina. O objetivo deste trabalho foi avaliar a eficiencia de uma atmosfera com CO2 no controle de Rhyzoperta dominica (Fabr.) (Coleoptera: bostrichidae) em graos de trigo armazenados. O trabalho constou de cinco concentracoes de CO2 (0, 30, 40, 50 e 60% completadas com N2), tres periodos de exposicao (5, 10, 15 dias), tres populacoes de R. dominica (Fabr.) (Coleoptera: Bostrichidae) (Campo Mourao, PR, Sete Lagoas, MG e Santa Rosa, RS) e sete fases de desenvolvimento do inseto (ovo, larva de 1., 2., 3. e 4. instar, pupa e adulto) com tres repeticoes. As diferentes fases de R. dominica foram acondicionadas em tecido organza e levadas para camaras de expurgo de... |
| Tipo: Artigo em periódico indexado (ALICE) |
Palavras-chave: Fumigacao; Gas; Grao; Praga; Grain; Pests; Fumigation; Gas; Stored grain pest. |
| Ano: 2000 |
URL: http://www.alice.cnptia.embrapa.br/handle/doc/101250 |
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| GENRO, T. C. M.; FARIA, B. M. de; ROSSETTO, J.; CEZIMBRA, I.; SAVIAN, J.; CARVALHO, P. C. de F.; BAYER, C.; BERNDT, A.; SILVA, M. A. P. da; YOKOO, M.; CARDOS, L. L.; OLIVEIRA, P. P. A.; VOLK, L. B. da S.; AMARAL, G. A. do. |
| bitstream/item/110639/1/Genro-et-al.pdf |
| Tipo: Artigo de divulgação na mídia (INFOTECA-E) |
Palavras-chave: Gado de corte; Gas. |
| Ano: 2013 |
URL: http://www.infoteca.cnptia.embrapa.br/infoteca/handle/doc/998556 |
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| CORRÊA, R. S.; MEDEIROS, J. C.; MADARI, B. E.; CARVALHO, G. D.; COSTA, A. R. da.. |
| Os fluxos de N2O oriundos do solo estão entre os mais relevantes para os cálculos das emissões dos GEE. A quantificação das emissões desses gases pelo solo em longos períodos normalmente são realizadas extrapolando-se as emissões mensuradas em uma coleta para todo um período homogêneo. Contudo, para a condição de Cerrado brasileiro, não há trabalhos que faz referência ao melhor horário para a amostragem desses gases. Os objetivos do trabalho consistiram em determinar o horário que melhor representa o fluxo médio diário de N2O em um Latossolo Vermelho cultivado com pastagem na região do Cerrado, verificar qual o tempo máximo antes da saturação deste gás no interior da câmara estática utilizada e comparar o comportamento dos fluxos obtidos por esse método... |
| Tipo: Artigo em anais de congresso (ALICE) |
Palavras-chave: Cerrado; Gas; Efeito estufa. |
| Ano: 2013 |
URL: http://www.alice.cnptia.embrapa.br/handle/doc/984159 |
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| Zanine,Anderson de Moura; Santos,Edson Mauro; Dórea,João Ricardo Rebouças; Dantas,Paulo Alfredo de Santana; Silva,Thiago Carvalho da; Pereira,Odilon Gomes. |
| The objective of this experiment was to evaluate the effects of adding cassava scrapings on gas and effluent losses, dry matter recovery, pH, contents of N-NH3, organic acids and volatile fatty acids and the bromatological composition of elephant grass silages. It was used a randomized complete design, with four levels of cassava scrapings (0, 7, 15 or 30% natural matter) each one with four replications per level. The grass was cut at 50 days of regrowth and ensiled in 15-L silos, equipped with a Bunsen valve to allow gas outflow. The gas losses decreased quadratically with the addition of cassava scrapings, whereas effluent losses decreased linearly. Dry matter recovery increased quadratically with the addition of cassava scrapings. Dry matter (DM)... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Crude protein; Dry matter; Effluent; Fermentation; Gas. |
| Ano: 2010 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-35982010001200008 |
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| ALVAREZ, R. de C. F.; CRUSCIOL, C. A. C.; NASCENTE, A. S.; RODRIGUES, J. D.; HABERMANN, G.. |
| The objective of this work was to evaluate gas exchange rates, plant height, yield components, and productivity of upland rice, as affected by type and application time of plant growth regulators. A randomized block design, in a 4x2 factorial arrangement, with four replicates was used. Treatments consisted of three growth regulators (mepiquat chloride, trinexapac.ethyl, and paclobutrazol), besides a control treatment applied at two different phenological stages: early tillering or panicle primordial differentiation. The experiment was performed under sprinkler.irrigated field conditions. Net CO2 assimilation, stomatal conductance, plant transpiration, and water.use efficiency were measured four times in Primavera upland rice cultivar, between booting and... |
| Tipo: Artigo em periódico indexado (ALICE) |
Palavras-chave: Condutância estomática; Arroz; Oryza sativa; Transpiração vegetal; Fotossíntese; Estatura da planta; Gas. |
| Ano: 2012 |
URL: http://www.alice.cnptia.embrapa.br/handle/doc/941332 |
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| SAVIAN, J. V.; BARTH NETO, A.; DAVID, D. B. de; BREMM, C.; SCHONS, R. M. T.; GENRO, T. C. M.; AMARAL, G. A. do; GERE, J.; McMANUS, C. M.; BAYER, C.; CARVALHO, P. C. de F.. |
| 2014 |
| Tipo: Artigo em periódico indexado (ALICE) |
Palavras-chave: Ovino; Efeito estufa; Gas; Metano. |
| Ano: 2014 |
URL: http://www.alice.cnptia.embrapa.br/handle/doc/987863 |
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| ABREU, U. G. P. de; DIAS, F. R. T.; BARIONI, L. G.; FASIABEN, M. do C. R.; LAMPERT, V. do N.; COSTA, F. P.; MOREIRA, J. M. M. A. P.; GOMES, E. G.. |
| This paper aims at evaluating the efficiency of beef cattle productive systems in the Cerrado, Pampa and Pantanal biomes, regarding their emissions intensity (CO2 equivalent per kilogram of carcass weight produced). |
| Tipo: Artigo em anais de congresso (ALICE) |
Palavras-chave: Efeito estufa; Gas; Gado de corte; Greenhouse gas emissions; Beef cattle. |
| Ano: 2016 |
URL: http://www.alice.cnptia.embrapa.br/handle/doc/1057454 |
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| Homem Junior,Antonio Carlos; Ezequiel,Jane Maria Bertocco; Perez,Henrique Leal; Almeida,Marco Tulio Costa; Paschoaloto,Josimari Regina; Carvalho,Vanessa Barbosa de; Cremasco,Leonardo Fernandes; Costa,Macella Borsonello da. |
| Methodological variations in the amount of sample incubated and the type of rumen fluid used are commonly observed. This study evaluated the effect of three sample amounts (0.6, 1.3 or 2.6g DM 100mL-1 of rumen fluid) incubated in rumen fluid buffered (BRF-buffered rumen fluid) or not (PRF-pure rumen fluid) on total gas volume (TV), methane (CH4) production, dry matter degradation (DM Deg) and final pH of corn silage incubated in vitro. The highest DM Deg was reached with the lowest amounts of sample (0.6 and 1.3g of DM 100mL-1 of rumen fluid). The sample amount of 2.6g associated with PRF reduced CH4 production (P<0.05), compared with the amounts of 0.6 and 1.3g DM 100mL-1, which had similar CH4 production (P>0.05). The use of BRF caused no effect on... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Degradation; Gas; Incubation; Methane; PH. |
| Ano: 2015 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-84782015001202229 |
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| Registros recuperados: 30 | |
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