2,205 research outputs found

    Effects of short days on stem elongation in some indeterminate dry bean cultivars adapted to the tropics

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    The effect of 2 daylength treatments (11 and 15 h) on stem elongation was determined in 5 indeterminate bean cv. (G 17650, G 2997, DOR 44, G 5475, and JU 80-11) under growth chamber conditions. Under the short day length, G 17650, a viny indeterminate var. showed the longest stem under all conditions. G 2997 and DOR 44, currently used in Central America in relay cropping, showed the highest degree of stem elongation, under short days compared with long days. This fact suggests that this trait is beneficial for relay cropping. (CIAT

    Image transfer protocol in progressively increasing resolution

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    A method of transferring digital image data over a communication link transforms and orders the data so that, as data is received by a receiving station, a low detail version of the image is immediately generated with later transmissions of data providing progressively greater detail in this image. User instructions are accepted, limiting the ultimate resolution of the image or suspending enhancement of the image except in certain user defined regions. When a low detail image is requested followed by a request for a high detailed version of the same image, the originally transmitted data of the low resolution image is not discarded or retransmitted but used with later data to improve the originally transmitted image. Only a single copy of the transformed image need be retained by the transmitting device in order to satisfy requests for different amounts of image detail

    Aspectos fisiológicos de la precocidad en el frijol común

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    El interés reciente en el desarrollo de cultivares de ¡maduración precoz de frijol ha planteado muchas preguntas relacionadas con la fisiología de cultivos de frijol. Primero es si la precocidad realmente ofrece ventajas que compensen la pérdida aparentemente inherente del potencial de rendimiento asociado con los ciclos cortos de crecimiento. Aceptando que la precocidad es deseable, uno puede preguntar cómo producir cultivares que combinen el nivel deseado de precocidad con un potencial de rendimiento aceptable. Este problema tiene dos facetas donde pueden ayudar las investigaciones de fisiología. 1a primera trata los efectos genéticos y ambientales sobre la fenología del frijol. Dado que el frijol es típicamente un cultivo que florece en respuesta a días cortos, los efectos del fotoperiodo son de interés específico. La segunda faceta es si ciertas características morfológicas o fisiológicas se pueden identificar para que los mejoradores las puedan usar como criterios de selección por rendimiento en materiales de maduración precoz. Este documento revisa la información disponible sobre estas cuestiones fisiológicas.Centro Internacional de Agricultura Tropical (CIAT)UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Agroalimentarias::Estación Experimental Agrícola Fabio Baudrit Moreno (EEAFBM

    Beangro V1.01 dry bean crop growth simulation model: user`s guide

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    A Comparison of Satellite Based, Modeled Derived Daily Solar Radiation Data with Observed Data for the Continental US

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    Many applications of simulation models and related decision support tools for agriculture and natural resource management require daily meteorological data as inputs. Availability and quality of such data, however, often constrain research and decision support activities that require use of these tools. Daily solar radiation (SRAD) data are especially problematic because the instruments require electronic integrators, accurate sensors are expensive, and calibration standards are seldom available. The Prediction Of Worldwide Energy Resources (NASA/POWER; power.larc.nasa.gov) project at the NASA Langley Research Center estimates daily solar radiation based on data that are derived from satellite observations of outgoing visible radiances and atmospheric parameters based upon satellite observations and assimilation models. The solar data are available for a global 1 degree x 1 degree coordinate grid. SRAD can also be estimated based on attenuation of extraterrestrial radiation (Q0) using daily temperature and rainfall data to estimate the optical thickness of the atmosphere. This study compares daily solar radiation data from NASA/POWER (SRADNP) with instrument readings from 295 stations (SRADOB), as well as with values that were estimated with the WGENR solar generator. WGENR was used both with daily temperature and precipitation records from the stations reporting solar data and records from the NOAA Cooperative Observer Program (COOP), thus providing two additional sources of solar data, SRADWG and SRADCO. Values of SRADNP for different grid cells consistently showed higher correlations (typically 0.85 to 0.95) with SRADOB data than did SRADWG or SRADCO for sites within the corresponding cells. Mean values of SRADOB, SRADWG and SRADNP for sites within a grid cell usually were within 1 MJm-2d-1 of each other, but NASA/POWER values averaged 1.1 MJm-2d-1 lower than SRADOB. The magnitude of this bias was greater at lower latitudes and during summer months and may be at least partially explained by assumptions in ambient aerosol properties. Overall, the NASA/POWER solar radiation data are a promising resource for regional modeling studies where realistic accounting of historic variation is required

    Constraints on Primordial Nongaussiantiy from the High-Redshift Cluster MS1054--03

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    The implications of the massive, X-ray selected cluster of galaxies MS1054--03 at z=0.83z=0.83 are discussed in light of the hypothesis that the primordial density fluctuations may be nongaussian. We generalize the Press-Schechter (PS) formalism to the nongaussian case, and calculate the likelihood that a cluster as massive as MS1054 would appear in the EMSS. The probability of finding an MS1054-like cluster depends only on \omegam and the extent of primordial nongaussianity. We quantify the latter by adopting a specific functional form for the PDF, denoted ψλ,\psi_\lambda, which tends to Gaussianity for λ1,\lambda\gg 1, and show how λ\lambda is related to the more familiar statistic T,T, the probability of 3σ\ge 3\sigma fluctuations for a given PDF relative to a Gaussian. We find that Gaussian initial density fluctuations are consistent with the data on MS1054 only if \omegam\simlt 0.2. For \omegam\ge 0.25 a significant degree of nongaussianity is required, unless the mass of MS1054 has been substantially overestimated by X-ray and weak lensing data. The required amount of nongaussianity is a rapidly increasing function of \omegam for 0.25 \le \omegam \le 0.45, with λ1\lambda \le 1 (T \simgt 7) at the upper end of this range. For a fiducial \omegam=0.3, \omegal=0.7 universe, favored by several lines of evidence we obtain an upper limit λ10,\lambda \le 10, corresponding to a T3.T\ge 3. This finding is consistent with the conclusions of Koyama, Soda, & Taruya (1999), who applied the generalized PS formalism to low (z\simlt 0.1) and intermediate (z\simlt 0.6) redshift cluster data sets.Comment: 15 pages, 11 figures, submitted to the Astrophysical Journal, uses emulateapj.st

    Two-phase concurrent flow in packed beds

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    Pressure drop and liquid saturation accompanying two-phase concurrent flow have been studied in a variety of packings and with gas-liquid systems having a wide range of fluid properties. Two basic flow patterns were observed with nonfoaming systems. Correlations of pressuredrop and liquid-saturation data were obtained in terms of the single-phase friction losses for the liquid and the gas when each flows alone in the bed. Deviations from the correlation with foaming systems are discussed and illustrated with sample data.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/37316/1/690070213_ftp.pd
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