38,720 research outputs found

    Comparison of 30 day integrations with and without interactive clouds

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    A cloud radiation interaction parameterization package has recently been incorporated into a global spectral General Circulation Model (GCM) used for extended range prediction studies at GFDL. The elements of this package are summarized. Analysis of the time mean radiative and dynamical responses suggests that cloud radiation interaction has a favorable impact, overall, on systematic errors. The possible relevance of this sensitivity study to FIRE is mentioned

    Inflatable stretcher to transport patients

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    Inflatable plastic bag inside strong, inflexible outer bag facilitates emergency transport of seriously burned or disabled patients. When the bag is inflated the patient is completely immobilized and cushioned from external shock. Air for breathing, temperature controls and communications may be provided by appropriate plug-in connections

    Ion implantation damage of silicon as observed by optical reflection spectroscopy in the 1 to 6 eV region

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    Optical reflection spectra of crystalline, sputtered, and ion implanted silicon specimens are presented. Characteristic aspects of the spectra of ion implanted specimens are related to lattice damage

    The study of excited oxygen molecule gas species production and quenching on thermal protection system materials

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    The detection of excited oxygen and ozone molecules formed by surface catalyzed oxygen atom recombination and reaction was investigated by laser induced fluorescence (LIF), molecular beam mass spectrometric (MBMS), and field ionization (FI) techniques. The experiment used partially dissociated oxygen flows from a microwave discharge at pressures in the range from 60 to 400 Pa or from an inductively coupled RF discharge at atmospheric pressure. The catalyst materials investigated were nickel and the reaction cured glass coating used for Space Shuttle reusable surface insulation tiles. Nonradiative loss processes for the laser excited states makes LIF detection of O2 difficult such that formation of excited oxygen molecules could not be detected in the flow from the microwave discharge or in the gaseous products of atom loss on nickel. MBMS experiments showed that ozone was a product of heterogeneous O atom loss on nickel and tile surfaces at low temperatures and that ozone is lost on these materials at elevated temperatures. FI was separately investigated as a method by which excited oxygen molecules may be conveniently detected. Partial O2 dissociation decreases the current produced by FI of the gas

    A Bio-economic Model of a Shrimp Hatchery in the Mekong River Delta of Vietnam

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    Shrimp culture areas and production of the Mekong Delta cover about 60 percent of the total shrimp areas and production of Vietnam. Especially, the Delta contributes about 80 percent of the total shrimp production for export. Rapid development of the shrimp industry is raising a number of serious problems that need to be solved. Shrimp seed supply (post larvae production) plays an essential role in the shrimp industry and it is one of the most important constraints to the development of the shrimp industry in the Delta. The focus of this study is aimed at obtaining an improvement in both the profit per day and post larvae production of the shrimp hatchery in the Mekong River Delta of Vietnam. A Monte Carlo simulation approach was applied to develop a stochastic and dynamic bio-economic model of a shrimp hatchery in the Delta. Initial results and policy recommendations are based on the analysis of the hatchery system simulation using a forward recursion approach and by changing the most important assumptions.Shrimp hatchery, larval stage, system simulation modelling, Agricultural and Food Policy, Production Economics,

    The Obscured Fraction of AGN in the XMM-COSMOS Survey: A Spectral Energy Distribution Perspective

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    The fraction of AGN luminosity obscured by dust and re-emitted in the mid-IR is critical for understanding AGN evolution, unification, and parsec-scale AGN physics. For unobscured (Type-1) AGN, where we have a direct view of the accretion disk, the dust covering factor can be measured by computing the ratio of re-processed mid-IR emission to intrinsic nuclear bolometric luminosity. We use this technique to estimate the obscured AGN fraction as a function of luminosity and redshift for 513 Type-1 AGN from the XMM-COSMOS survey. The re-processed and intrinsic luminosities are computed by fitting the 18-band COSMOS photometry with a custom SED-fitting code, which jointly models emission from: hot-dust in the AGN torus, the accretion disk, and the host-galaxy. We find a relatively shallow decrease of the luminosity ratio as a function of Lbol, which we interpret as a corresponding decrease in the obscured fraction. In the context of the receding torus model, where dust sublimation reduces the covering factor of more luminous AGN, our measurements require a torus height which increases with luminosity as h ~ Lbol^{0.3-0.4}. Our obscured fraction-luminosity relation agrees with determinations from SDSS censuses of Type-1 and Type-2 quasars, and favors a torus optically thin to mid-IR radiation. We find a much weaker dependence of obscured fraction on 2-10 keV luminosity than previous determinations from X-ray surveys, and argue that X-ray surveys miss a significant population of highly obscured Compton-thick AGN. Our analysis shows no clear evidence for evolution of obscured fraction with redshift.Comment: 33 pages, 24 figures, ApJ accepte
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