36,995 research outputs found

    Analytical studies of in-reactor tests of a nuclear light bulb unit cell

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    Analytical studies of in-reactor tests of nuclear light bulb unit cell using Pewee, nuclear furnace, and high flux isotope reactor

    Relation of agronomic and multispectral reflectance characteristics of spring wheat canopies

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    The relationships between crop canopy variables such as leaf area index (LAI) and their multispectral reflectance properties were investigated along with the potential for estimating canopy variables from remotely sensed reflectance measurements. Reflectance spectra over the 0.4 to 2.5 micron wavelength range were acquired during each of the major development stages of spring wheat canopies at Williston, North Dakota, during three seasons. Treatments included planting date, N fertilization, cultivar, and soil moisture. Agronomic measurements included development stage, biomass, LAI, and percent soil cover. High correlations were found between reflectance and percent cover, LAI, and biomass. A near infrared wavelength band, 0.76 to 0.90 microns, was most important in explaining variation in LAI and percent cover, while a middle infrared band, 2.08 to 2.35 microns, explained the most variation in biomass and plant water content. Transformations, including the near infrared/red reflectance ratio and greenness index, were also highly correlated to canopy variables. The relationship of canopy variables to reflectance decreased as the crop began to ripen. the canopy variables could be accurately predicted using measurements from three to five wavelength bands. The wavelength bands proposed for the thematic mapper sensor were more strongly related to the canopy variables than the LANDSAT MSS bands

    Quality Assessment of Summer and Autumn Carrots from a Biodynamic Breeding Project and Correlations of Physico-Chemical Parameters and Features Determined by Picture Forming Methods

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    Introduction: Assessment of product quality is of special significance in organic farming and includes the supervision of crop quality in different growing systems (e.g., Fleck et al. 1998) and the characterisation of different cultivars. Several methods have been developed and applied for this purpose, e.g., the physico-chemical analysis of crops, picture forming methods (PFMs) and plant observation. So far only limited information is available on the comparability of these methods. This contribution aims to compare the results of the analysis of physico-chemical parameters of summer and autumn carrots with features determined by PFMs by means of correlation analysis. Conclusions: High and significant correlation coefficients were found between quality parameters of summer and autumn carrots from a biodynamical breeding project determined by physico-chemical analysis and PFMs. This indicates close relationships between the two quality approaches which should be investigated further in future work

    Searching for molecular outflows in Hyper-Luminous Infrared Galaxies

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    We present constraints on the molecular outflows in a sample of five Hyper-Luminous Infrared Galaxies using Herschel observations of the OH doublet at 119 {\mu}m. We have detected the OH doublet in three cases: one purely in emission and two purely in absorption. The observed emission profile has a significant blueshifted wing suggesting the possibility of tracing an outflow. Out of the two absorption profiles, one seems to be consistent with the systemic velocity while the other clearly indicates the presence of a molecular outflow whose maximum velocity is about ~1500 km/s. Our analysis shows that this system is in general agreement with previous results on Ultra-luminous Infrared Galaxies and QSOs, whose outflow velocities do not seem to correlate with stellar masses or starburst luminosities (star formation rates). Instead the galaxy outflow likely arises from an embedded AGN.Comment: Accepted for publication in MNRAS. 13 pages, 11 figures, 4 table

    A New Species of \u3ci\u3ePediobius\u3c/i\u3e (Hymenoptera: Eulophidae) Parasitizing \u3ci\u3eChyliza Apicalis\u3c/i\u3e (Diptera: Psilidae) in Ash Trees Attacked by \u3ci\u3eAgrilus Planipennis\u3c/i\u3e (Coleoptera: Buprestidae)

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    Pediobius chylizae, spec. nov. (Hymenoptera: Eulophidae), is described as new and illustrated. This parasitoid has been reared from the puparia of Chyliza apicalis Loew (Diptera: Psilidae) collected from under the bark of ash trees (Oleaceae: Fraxinus spp.) dying after attack by the emerald ash borer, Agrilus planipennis Fairmaire (Coleptera: Buprestidae), an invasive beetle from Asia. This species is compared with related species of Pediobius from the Holarctic Region

    Evaluation of a segment-based LANDSAT full-frame approach to corp area estimation

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    As the registration of LANDSAT full frames enters the realm of current technology, sampling methods should be examined which utilize other than the segment data used for LACIE. The effect of separating the functions of sampling for training and sampling for area estimation. The frame selected for analysis was acquired over north central Iowa on August 9, 1978. A stratification of he full-frame was defined. Training data came from segments within the frame. Two classification and estimation procedures were compared: statistics developed on one segment were used to classify that segment, and pooled statistics from the segments were used to classify a systematic sample of pixels. Comparisons to USDA/ESCS estimates illustrate that the full-frame sampling approach can provide accurate and precise area estimates

    Analytical studies of nuclear light bulb engine radiant heat transfer and performance characteristics

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    Analytical model of nuclear light bulb engine radiant heat transfer and engine performance, dynamics and control, heat loads and shutdown characteristic

    Studies of nuclear light bulb start-up conditions and engine dynamics

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    Deep Space Network for two-way communications with unmanned spacecraft at planetary distances - Vol.
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