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| Registros recuperados: 60 | |
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| VASCONCELOS,PAULO M.; ONOE,ARTUR T.; KAWASHITA,KOJI; SOARES,ADALBERTO J.; TEIXEIRA,WILSON. |
| Laser heating 40Ar/39Ar geochronology provides high analytical precision and accuracy, mum-scale spatial resolution, and statistically significant data sets for the study of geological and planetary processes. A newly commissioned 40Ar/39Ar laboratory at CPGeo/USP, São Paulo, Brazil, equips the Brazilian scientific community with a new powerful tool applicable to the study of geological and cosmochemical processes. Detailed information about laboratory layout, environmental conditions, and instrumentation provides the necessary parameters for the evaluation of the CPGeo/USP 40Ar/39Ar suitability to a diverse range of applications. Details about analytical procedures, including mineral separation, irradiation at the IPEN/CNEN reactor at USP, and mass... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Geochronology; 40Ar/39Ar method; Irradiation; Calibration. |
| Ano: 2002 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652002000200008 |
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| Rodríguez,N.M.; Campos,W.E.; Lachica,M.L.; Borges,I.; Gonçalves,L.C.; Borges,A.L.C.C.; Saliba,E.O.S.. |
| An indirect calorimetry system for rapid determination of CO2 and CH4 production and O2 consumption to estimate heat production of animals was built at Escola de Veterinária da Universidade Federal de Minas Gerais, Brazil. Procedures for determination of correction and calibration factors for gas analyzers and the whole system, using standard test gases were described. In addition, a metabolic trial was performed to evaluate heat production of lambs fed ad libitum. It is concluded that the system is suitable for heat production determinations in small and medium size animals. |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Calibration; Open circuit; Respirometry. |
| Ano: 2007 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0102-09352007000200033 |
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| Malik, Mashkoor; Lurton, Xavier; Mayer, Larry. |
| Multibeam echosounders (MBES) have become a widely used acoustic remote sensing tool to map and study the seafloor, providing co-located bathymetry and seafloor backscatter. Although the uncertainty associated with MBES-derived bathymetric data has been studied extensively, the question of backscatter uncertainty has been addressed only minimally and hinders the quantitative use of MBES seafloor backscatter. This paper explores approaches to identifying uncertainty sources associated with MBES-derived backscatter measurements. The major sources of uncertainty are catalogued and the magnitudes of their relative contributions to the backscatter uncertainty budget are evaluated. These major uncertainty sources include seafloor insonified area (1–3 dB),... |
| Tipo: Text |
Palavras-chave: Multibeam echosounder; Calibration; Incidence angle. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00429/54018/57435.pdf |
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| Manise,Nicolas; Neyt,Xavier; Acheroy,Marc. |
| The scatterometer on-board ERS-2, earth-observation satellite developed by the European Space Agency, is an active real aperture radar instrument designed to measure the backscatter coefficient 0 from the earth. Its main utility is to measure physical parameters such as wind speeds and directions over the sea surface. Due to malfunctions of the on-board gyroscopes and even though a new attitude and orbit control system is used, the yaw-orientation of the spacecraft still exhibits random variations from the nominal attitude. This unpredictable attitude requires re-developing the calibration chain of the scatterometer instrument. Distributed targets, such as the rain forest, are used to perform a relative calibration while transponders situated at known... |
| Tipo: Journal article |
Palavras-chave: Scatterometer; Calibration; Transponder. |
| Ano: 2004 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-65382004000300011 |
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| Sicre, Ma; Bard, E; Ezat, U; Rostek, F. |
| The C(37)-C(39) alkenones were quantified in suspended particulate matter obtained from the surface waters of the North Atlantic, including the Nordic seas, over a temperature range of 4degrees20 C. U(37)(K') values were linearly correlated to temperature over the entire range covered by our data set, i.e., 420 C (U(37)(K') = 0.027T + 0.036, r(2) = 0.97). The compilation of water column data from the Atlantic, Pacific, and Southern Ocean and Mediterranean Sea suggests that the linear model may not be the best function for fitting U(37)(K') and in situ temperature values. It also shows that suspended matter data from warm waters (T >20degreesC) are still needed to constrain the equation of the global curve. High abundances of C(37: 4) were found in the... |
| Tipo: Text |
Palavras-chave: Alkenones; Paleotemperature; Calibration; Atlantic Ocean; Plankton; Geochemistry; Marine geochemistry; Global change; Biogeochemical processes (4805); Oceanography; Paleoceanography. |
| Ano: 2002 |
URL: https://archimer.ifremer.fr/doc/00223/33393/31866.pdf |
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| Boutron, Olivier; Bertrand, Olivier; Fiandrino, Annie; Hoehener, Patrick; Sandoz, Alain; Cherain, Yves; Coulet, Eric; Chauvelon, Philippe. |
| The spatiotemporal structure of wind-driven circulation patterns and associated water exchanges can drive important bio-hydrodynamic interactions in shallow lagoons. The Vaccares lagoon system is a complex shallow hydrosystem located in the central part of the Rhone Delta (France). It is internationally recognized as part of a biosphere reserve within the framework of UNESCO's Man and Biosphere Programme, and as a RAMSAR site. Due to its frequent occurrence in this area, and considering the shallowness of the Vaccares lagoon system, wind is assumed to play a major role in the hydrodynamic and biological processes. In this study, a hydrodynamic model was developed to investigate the structure of wind-driven circulations in the Vaccares lagoon system, to... |
| Tipo: Text |
Palavras-chave: Coastal lagoon; Mathematical model; Hydrodynamics; Calibration; Validation; Wind-driven circulation. |
| Ano: 2015 |
URL: http://archimer.ifremer.fr/doc/00303/41382/40558.pdf |
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| Zabolotskikh, Elizaveta; Mitnik, Leonid; Chapron, Bertrand. |
| In this study, we considered the geophysical model for microwave brightness temperature (BT) simulation for the Atmosphere-Ocean System under non-precipitating conditions. The model is presented as a combination of atmospheric absorption and ocean emission models. We validated this model for two satellite instruments-for Advanced Microwave Sounding Radiometer-Earth Observing System (AMSR-E) onboard Aqua satellite and for Special Sensor Microwave Imager/Sounder (SSMIS) onboard F16 satellite of Defense Meteorological Satellite Program (DMSP) series. We compared simulated BT values with satellite BT measurements for different combinations of various water vapor and oxygen absorption models and wind induced ocean emission models. A dataset of clear sky... |
| Tipo: Text |
Palavras-chave: Calibration; Geophysical model; Numerical simulation; SSMIS; AMSR-E; Satellite passive microwave. |
| Ano: 2014 |
URL: https://archimer.ifremer.fr/doc/00190/30101/28628.pdf |
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| Smith, V. Kerry; van Houtven, George; Pattanayak, Subhrendu K.. |
| This paper proposes and illustrates the use of a new approach to benefit transfer for the non-market valuation of environmental resources. It treats transfer as an identification problem that requires assessing whether available benefit estimates permit the parameters of a preference function to be identified. The transfer method proposed uses these identifying restrictions to calibrate preference parameters and bases the benefit estimates on that preference function. The approach is illustrated using travel cost, hedonic and contingent valuation estimates, as well as combinations of estimates. It has three potential advantages over conventional practice: (1) it allows multiple, potentially overlapping estimates of the benefits of an improvement in... |
| Tipo: Working or Discussion Paper |
Palavras-chave: Benefit transfer; Calibration; Non-market valuation; Environmental Economics and Policy; D61; Q20; H40. |
| Ano: 1999 |
URL: http://purl.umn.edu/10607 |
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| Kanwar, Ramesh S.; Reungsang, Pipat; Jha, Manoj K.; Gassman, Philip W.; Ahmad, Khalil; Saleh, Ali. |
| A validation study has been performed using the Soil and Water Assessment Tool (SWAT) model with data collected for the Upper Maquoketa River Watershed (UMRW), which drains over 16,000 ha in northeast Iowa. This validation assessment builds on a previous study with nested modeling for the UMRW that required both the Agricultural Policy EXtender (APEX) model and SWAT. In the nested modeling approach, edge-of-field flows and pollutant load estimates were generated for manure application fields with APEX and were then subsequently routed to the watershed outlet in SWAT, along with flows and pollutant loadings estimated for the rest of the watershed routed to the watershed outlet. In the current study, the entire UMRW cropland area was simulated in SWAT, which... |
| Tipo: Working or Discussion Paper |
Palavras-chave: Calibration; Modeling; Nitrate; SWAT; Validation; Water quality; Resource /Energy Economics and Policy. |
| Ano: 2005 |
URL: http://purl.umn.edu/18440 |
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| Amirouche, mawhoub. |
| The search for decision-making tools is essential in order to control agricultural practices and plan for sustainable agriculture that respects the environment. To this end, FAO has developed an evaluation model called AquaCrop, which covers most technical routes, including fertilization. In this perspective, this study focuses on the AquaCrop model (v6.1) to calibrate it for the simulation of lettuce crop yields (Lactuca sativa L), under different fertilization levels for the trial periods (2015/2016) and (2016/2017). Four levels of fertilization were examined under rain conditions, namely T1 (0 kg N/ha), T2 (60 kg N/ha), T3 (120 kg N/ha) and T4 (180 kg N/ha). The model performance was evaluated using the coefficient of determination (R2), the square root... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: AquaCrop; Lettuce; Calibration; Validation; Fertility stress; Water productivity. |
| Ano: 2021 |
URL: http://www.cigrjournal.org/index.php/Ejounral/article/view/6195 |
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| Schmittner, Andreas; Bostock, Helen C.; Cartapanis, Olivier; Curry, William B.; Filipsson, Helena L.; Galbraith, Eric D.; Gottschalk, Julia; Carlos Herguera, Juan; Hoogakker, Babette; Jaccard, Samuel L.; Lisiecki, Lorraine E.; Lund, David C.; Martinez-mendez, Gema; Lynch-stieglitz, Jean; Mackensen, Andreas; Michel, Elisabeth; Mix, Alan C.; Oppo, Delia W.; Peterson, Carlye D.; Repschlaeger, Janne; Sikes, Elisabeth L.; Spero, Howard J.; Waelbroeck, Claire. |
| The carbon isotope composition (C-13) of seawater provides valuable insight on ocean circulation, air-sea exchange, the biological pump, and the global carbon cycle and is reflected by the C-13 of foraminifera tests. Here more than 1700 C-13 observations of the benthic foraminifera genus Cibicides from late Holocene sediments (C-13(Cibnat)) are compiled and compared with newly updated estimates of the natural (preindustrial) water column C-13 of dissolved inorganic carbon (C-13(DICnat)) as part of the international Ocean Circulation and Carbon Cycling (OC3) project. Using selection criteria based on the spatial distance between samples, we find high correlation between C-13(Cibnat) and C-13(DICnat), confirming earlier work. Regression analyses indicate... |
| Tipo: Text |
Palavras-chave: Carbon; Isotopes; Benthic; Foraminifera; Calibration. |
| Ano: 2017 |
URL: https://archimer.ifremer.fr/doc/00661/77326/78788.pdf |
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| Registros recuperados: 60 | |
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