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| Registros recuperados: 51 | |
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| Wailes, Eric J.; Chavez, Eddie C.. |
| The Arkansas Global Rice Model is based on a multi-country statistical simulation and econometric framework. The model is disaggregated by five world regions: Africa, the Americas, Asia, Europe, and Oceania. Each region includes country models which have a supply sector, a demand sector, a trade, stocks and price linkage equations. All equations used in this model are estimated using econometric procedures or identities. Estimates are based upon a set of explanatory variables including exogenous macroeconomic factors such as income, population, inflation rate, technology development, and especially, government determined policy variables which reflect the various mechanisms by which countries intervene in their rice sector economy. Individual country... |
| Tipo: Report |
Palavras-chave: Rice; Trade model; Policy; Agricultural and Food Policy; Research and Development/Tech Change/Emerging Technologies; CO2; C61; F11; F14; Q17; Q18. |
| Ano: 2011 |
URL: http://purl.umn.edu/102650 |
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| Jones, Steve D.; Le Quere, Corinne; Roedenbeck, Christian; Manning, Andrew C.; Olsen, Are. |
| We have developed a statistical gap-filling method adapted to the specific coverage and properties of observed fugacity of surface ocean CO2 (fCO2). We have used this method to interpolate the Surface Ocean CO2 Atlas (SOCAT) v2 database on a 2.5°×2.5° global grid (south of 70°N) for 1985–2011 at monthly resolution. The method combines a spatial interpolation based on a “radius of influence” to determine nearby similar fCO2 values with temporal harmonic and cubic spline curve-fitting, and also fits long-term trends and seasonal cycles. Interannual variability is established using deviations of observations from the fitted trends and seasonal cycles. An uncertainty is computed for all interpolated values based on the spatial and temporal range of the... |
| Tipo: Text |
Palavras-chave: Ocean; CO2; Interpolation. |
| Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00293/40403/38961.pdf |
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| Suckling, Coleen C.; Clark, Melody S.; Richard, Joelle; Morley, Simon A.; Thorne, Michael A. S.; Harper, Elizabeth M.; Peck, Lloyd S.. |
| This study examined the effects of long-term culture under altered conditions on the Antarctic sea urchin, Sterechinus neumayeri.Sterechinus neumayeri was cultured under the combined environmental stressors of lowered pH (-03 and -05 pH units) and increased temperature (+2 degrees C) for 2years. This time-scale covered two full reproductive cycles in this species and analyses included studies on both adult metabolism and larval development. Adults took at least 6-8months to acclimate to the altered conditions, but beyond this, there was no detectable effect of temperature or pH. Animals were spawned after 6 and 17months exposure to altered conditions, with markedly different outcomes. At 6months, the percentage hatching and larval survival rates were... |
| Tipo: Text |
Palavras-chave: CO2; Echinoderm; Gonad maturation; Larval development; Oxygen consumption; Vitellogenesis. |
| Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00617/72874/71930.pdf |
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| Souza,Taylor Lima de; Guelfi,Douglas Ramos; Silva,André Leite; Andrade,André Baldansi; Chagas,Wantuir Filipe Teixeira; Cancellier,Eduardo Lopes. |
| ABSTRACT The market of stabilized, slow and controlled release nitrogen (N) fertilizers represents 1% of the world fertilizer consumption. On the other hand, the increase in availability, innovation and application of these technologies could lead to the improvement of N use efficiency in agroecossystems and to the reduction of environmental impacts. The objective of this study was to quantify agronomic efficiency relative index, ammonia volatilization, and CO2 emissions from conventional, stabilized and controlled release N fertilizers in corn summer crop. The experiment was carried out in a corn crop area located in Lavras, state of Minas Gerais, Brazil, without irrigation. All treatments were applied in topdressing at rate of 150 kg ha-1 N. N-NH3 losses... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: CO2; NH3 loss; No-tillage; Zea mays L.. |
| Ano: 2017 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1413-70542017000500494 |
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| Hoe, Lam Weng; Saiful Hafizah, Jaaman; Zaidi, Isa. |
| Risk is one of the important parameters in portfolio optimization problem. Since the introduction of the mean-variance model, variance has become the most common risk measure used by practitioners and researchers in portfolio optimization. However, the mean-variance model relies strictly on the assumptions that assets returns are multivariate normally distributed or investors have a quadratic utility function. Many studies have proposed different risk measures to overcome the drawbacks of variance. The purpose of this paper is to discuss and compare the portfolio compositions and performances of four different portfolio optimization models employing different risk measures, specifically the variance, absolute deviation, minimax and semi-variance. Results... |
| Tipo: Journal Article |
Palavras-chave: Portfolio; Optimization; Risk measures; Variance.; Financial Economics; CO2; C61; G11. |
| Ano: 2010 |
URL: http://purl.umn.edu/95934 |
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| Doran,Gregory; Zander,Alek. |
| The rate of carbon dioxide production is commonly used as a measure of microbial activity in the soil. The traditional method of CO2 determination involves trapping CO2 in an alkali solution and then determining CO2 concentration indirectly by titration of the remaining alkali in the solution. This method is still commonly employed in laboratories throughout the world due to its relative simplicity and the fact that it does not require expensive, specific equipment. However, there are several drawbacks: the method is time-consuming, requires large amounts of chemicals and the consistency of results depends on the operator's skills. With this in mind, an improved method was developed to analyze CO2 captured in alkali traps, which is cheap and relatively... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: CO2; Microbial respiration; Titration; Infrared; FIA. |
| Ano: 2012 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832012000200004 |
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| Rodríguez-Trejo,Dante A.; Pulido-Luna,Jorge A.; Martínez-Muñoz,Pedro; Martínez-Lara,Pedro J.; Monjarás-Vega,Norma A.. |
| Resumen Los incendios forestales y las quemas agropecuarias contribuyen al cambio climático global y una herramienta para reducir emisiones de CO2 es el fuego prescrito. El objetivo de este estudio fue evaluar consumo de combustibles superficiales, comportamiento del fuego y emisiones en quemas prescritas. La hipótesis fue que los incendios afectan más combustibles y producen mayores emisiones que las quemas. En seis parcelas experimentales de un encinar tropical de Chiapas, México, establecidas al azar, se aplicaron quemas prescritas: tres a favor de viento y pendiente y tres en contra. Las mediciones y estimaciones incluyeron: las cargas iniciales y residuales de combustibles, factores de consumo y emisiones de CO2. Durante las quemas se registraron... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: CO2; Cambio climático; Efecto invernadero; Fuego; Manejo del fuego. |
| Ano: 2018 |
URL: http://www.scielo.org.mx/scielo.php?script=sci_arttext&pid=S1405-31952018000600783 |
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| Vazquez-rodriguez, Marcos; Touratier, Franck; Lo Monaco, Claire; Waugh, D. W.; Padin, X. A.; Bellerby, R. G. J.; Goyet, Catherine; Metzl, Nicolas; Rios, Aida F.; Perez, Fiz F.. |
| Five of the most recent observational methods to estimate anthropogenic CO2 (C-ant) are applied to a high-quality dataset from five representative sections of the Atlantic Ocean extending from the Arctic to the Antarctic. Between latitudes 60 degrees N-40 degrees S all methods give similar spatial distributions and magnitude of C-ant. However, discrepancies are found in some regions, in particular in the Southern Ocean and Nordic Seas. The differences in the Southern Ocean have a significant impact on the anthropogenic carbon inventories. The calculated total inventories of C-ant for the Atlantic referred to 1994 vary from 48 to 67 Pg (10(15) g) of carbon, with an average of 54 +/- 8 Pg C, which is higher than previous estimates. These results, both the... |
| Tipo: Text |
Palavras-chave: Deep equatorial atlantic; Northern indian-ocean; Water mass ages; CO2; Sea; Transport; Increase; Tracers; Models. |
| Ano: 2009 |
URL: https://archimer.ifremer.fr/doc/00202/31313/29724.pdf |
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| Vazquez-rodriguez, M.; Touratier, F.; Lo Monaco, C.; Waugh, D. W.; Padin, X. A.; Bellerby, R. G. J.; Goyet, C.; Metzl, N.; Rios, A.f.; Perez, F.f.. |
| Five of the most recent observational methods to estimate anthropogenic CO2 (Cant) are applied to a high-quality dataset from five representative sections of the Atlantic Ocean extending from the Arctic to the Antarctic. Between latitudes 60° N–40° S all methods give similar spatial distributions and magnitude of Cant. Conversely, large discrepancies are found in the Southern Ocean and Nordic Seas. The differences in the Southern Ocean have a significant impact on the anthropogenic carbon inventories. The calculated total inventories of Cant for the Atlantic referred to 1994 range from 48 to 67 Pg (1015 g) of carbon, with an average of 54±8 Pg C, which is higher than previous estimates. These results, both the detailed Cant distributions and extrapolated... |
| Tipo: Text |
Palavras-chave: Deep equatorial atlantic; Northern indian-ocean; Water mass ages; CO2; Sea; Transport; Increase; Tracers; Models. |
| Ano: 2008 |
URL: https://archimer.ifremer.fr/doc/00293/40430/38984.pdf |
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| DONAZZOLO,JOEL; BRACKMANN,AURI. |
| Objetivou-se avaliar, com o presente trabalho, o efeito da temperatura e do CO2 no armazenamento em atmosfera controlada sobre a conservação de caqui cv. Quioto. Foram avaliadas as temperaturas -1,0 e -0,5ºC, e pressões parciais de CO2 de 0; 5 e 10kPa, com os tratamentos arranjados em um esquema bifatorial. Os frutos foram avaliados após 3 meses de armazenamento mais 3 dias de exposição à temperatura ambiente (18-20ºC). Conforme os resultados, não foi constatada interação entre os fatores, havendo efeito significativo para temperatura somente na firmeza de polpa, em que -1,0ºC apresentou frutos mais firmes. As diferentes pressões parciais de CO2 não influenciaram a perda de peso e a firmeza de polpa. As podridões apresentaram uma resposta linear negativa... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Temperatura; CO2; Conservação. |
| Ano: 2002 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-29452002000200010 |
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| Magalhães,M.L.; Nishimura,L.T.; Souza,A.T.; Magalhães,C.F.; Mattos Júnior,E.; Honsho,C.S.; Paulino Júnior,D.. |
| RESUMO Objetivou-se avaliar os efeitos do pneumoperitônio e da posição de Trendelenburg sobre o fluxo de saída do ventrículo esquerdo em gatos anestesiados. Quatorze gatos foram alocados aleatoriamente em dois grupos, ambos submetidos ao pneumoperitônio com 10mmHg de dióxido de carbono (CO2). No grupo controle (GC n=7), os animais foram submetidos apenas ao pneumoperitônio e, no grupo Trendelenburg (GTREN n=7), os animais foram colocados em cefalodeclive 20° após o pneumoperitônio. A indução anestésica foi realizada com isoflurano, utilizando-se caixa de indução. Posteriormente, os animais foram mantidos sob anestesia inalatória com o mesmo fármaco. Foram avaliados a velocidade do fluxo de saída do ventrículo esquerdo (VFSVE), os gradientes máximo... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Gato; CO2; Doppler; Fluxo de saída; Trendelenburg. |
| Ano: 2017 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0102-09352017000501139 |
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| Garcia,Martha Regina Lucizano; Nahas,Ely. |
| Os efeitos da lotação de animais na produção de ovinos têm sido bastante estudados. No entanto, informações sobre seus efeitos na biomassa e nas atividades microbianas e, em conseqüência, na fertilidade do solo de pastagens são escassas. Neste trabalho, os efeitos da lotação de ovinos (LO) na biomassa e nas atividades microbianas responsáveis pela transformação dos compostos do C e N em solo de clima subtropical foram avaliados. As amostras de solo foram coletadas nas camadas de 0-10 e 10-20 cm de pastos com baixa LO (5 animais ha-1), alta LO (40-50 animais ha-1) e com ausência de animais, em um delineamento inteiramente casualizado em parcelas subdivididas, com seis repetições. Os maiores valores de biomassa microbiana e das atividades respiratória,... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Atividade biológica; CO2; Enzimas; Matéria orgânica. |
| Ano: 2007 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832007000200009 |
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| Moraes,Luiza; Rosa,Gabriel Martins da; Souza,Michele da Rosa Andrade Zimmermann de; Costa,Jorge Alberto Vieira. |
| ABSTRACT Microalgae are efficient at using solar energy to turn CO2 and nutrients into biomass containing lipids, proteins, carbohydrates and other compounds that may be used to produce bioproducts for human and animal consumption and pharmaceutical use. The aim of this study was to assess the effect of the NaNO3 and NaCl concentration on the growth kinetics, the biomass composition and the ability to biofix CO2 using the microalga Spirulina sp. LEB 18. The assays were carried out according to a 22 central composite design (CCD) with different concentrations of NaNO3 (1.25, 1.88 and 2.50 g L-1) and NaCl (1.00, 15.0 and 30.0 g L-1). The assays were carried out in 2 L vertical tubular photobioreactors at 30°C, 12 h light/dark and an injection of 12.0% v/v of... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: CO2; Fixation; Growth kinetics; Microalgae; Nutrients. |
| Ano: 2018 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132018000100410 |
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| Ghini,Raquel; Hamada,Emília; Bettiol,Wagner. |
| Human activities are altering greenhouse gas concentrations in the atmosphere and causing global climate change. In the near future, there will certainly be changes in the Brazilian phytosanitary scenario attributed to global climate change. The impacts of climate change can be positive, negative or neutral, since these changes can decrease, increase or have no impact on diseases, depending on each region or period. These impacts will also be observed on plants and other organisms as well as on other agroecosystem components. However, these impacts are not easily determined, and consequently, specialists from several areas must go beyond their disciplinary boundaries and placing the climate change impacts in a broader context. This review focuses on the... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: CO2; Global climate change; Global warming; Spatial analysis; Control. |
| Ano: 2008 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162008000700015 |
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| Lundberg, L. |
| The net air-sea exchange of CO2 in the ocean area enclosed by the Fram Strait in the north and by the Greenland-Scotland ridge in the south is estimated on the basis of oceanic pCO(2) data from three different expeditions. The data comprise observed pCO(2) as well as pCO(2) calculated from data on dissolved inorganic carbon (C-t), total alkalinity (TA) and pH. Data on atmospheric content of CO2 are available from two of the expeditions and are supplemented with monthly mean values from ocean station ''M'' (66 degrees N, 2 degrees E). Wind speed drawn from a data set with a spatial resolution of 75 km and a temporal resolution of six hours are used in the calculation. The pCO(2) data are interpolated to the same spatial resolution as that of the wind speed... |
| Tipo: Text |
Palavras-chave: CO2; AIR-SEA EXCHANGE; NORDIC SEAS; GAS EXCHANGE. |
| Ano: 1994 |
URL: http://archimer.ifremer.fr/doc/00098/20882/18496.pdf |
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| Silva Neto,Sabino Pereira da; Santos,Antonio Clementino dos; Leite,Raimundo Laerton de Lima; Dim,Valdinéia Patrícia; Neves Neto,Durval Nolasco das; Cruz,Rossini Sôffa da. |
| Foi conduzido um estudo utilizando análise de semivariogramas para quantificar a autocorrelação espacial dos estoques de carbono (EC) no solo, biomassa da gramínea e das plantas daninhas em três parcelas experimentais de pastagens de Brachiaria brizantha cv. Marandu com níveis baixo, médio e alto de degradação, cultivadas em Neossolo Quartzarênico Órtico. As coletas das plantas e do solo foram realizadas em malha de amostragem regular com distâncias de 5 x 5 m em área de 900 m². Os EC das pastagens foram submetidos às analises de estatística descritiva, ao teste não-paramétrico de Kruskal-Wallis ao nível de 5% de significância, ao estudo geoestatístico e interpolação por krigagem ordinária. A variabilidade espacial do EC foi observada dentro e entre as... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: CO2; Degradação de pastagem; Geoestatística; Inventário do carbono; Sequestro de carbono. |
| Ano: 2012 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0044-59672012000400013 |
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| Landschuetzer, Peter; Ilyina, Tatiana; Lovenduski, Nicole S.. |
| We use a neural network-based estimate of the sea surface partial pressure of CO2 (pCO(2)) derived from measurements assembled within the Surface Ocean CO2 Atlas to investigate the dominant modes of pCO(2) variability from 1982 through 2015. Our analysis shows that detrended and deseasonalized sea surface pCO(2) varies substantially by region and the respective frequencies match those from the major modes of climate variability (Atlantic Multidecadal Oscillation, Pacific Decadal Oscillation, multivariate ENSO index, Southern Annular Mode), suggesting a climate modulated air-sea exchange of CO2. We find that most of the regional pCO(2) variability is driven by changes in the ocean circulation and/or changes in biology, whereas the North Atlantic variability... |
| Tipo: Text |
Palavras-chave: Ocean; CO2; Variability; Carbon; Climate; Observations. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00675/78733/80972.pdf |
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| Registros recuperados: 51 | |
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