5,697 research outputs found

    Radiative flux measurements in the stratosphere

    Get PDF
    The objective is to determine how the stratospheric tropospheric exchange of water vapor is affected by the interaction of solar (visible) and planetary (infrared) radiation with tropical cumulonimbus anvils. This research involves field measurements from the ER-2 aircraft as well as radiative transfer modelling to determine heating and cooling rates and profiles that directly affect the exchange between the troposphere and the stratosphere

    Planetary astronomy and supporting laboratory research

    Get PDF
    The aim was to obtain form laboratory measurements the molecular parameters needed to interpret observations of planetary and cometary spectra, and to develop the analytical and computational techniques to interpret the observed spectra in terms of planetary atmospheres including solids and cometary ices. The gas phase molecular parameters measured include the intensities and half-widths of vib-rotational lines, total intensities of absorption bands, temperature dependencies, and absorption and pressure parameters in random-band models of absorption bands. Computation of line shapes of H2 quadrupole lines from quantum mechanical first principles for comparison with laboratory data and use in modeling of planetary atmospheres was accomplished. The solid phase measurements include band profile and quantitative intensity measurements and dependence on composition as well as thermal and photolytic processing which mimics the particular astrophysical environments. Work on GeH4, PH3, has made significant progress

    Packaging : el salto en el diseño gráfico

    Get PDF
    RESUMEN: Tratamos de aproximarnos, revisar y reflexionar sobre el objeto del packaging, que no es otro que el de diseñar un envase adecuado para conservar y proteger un producto para su consumo, a lo largo de toda la historia de la humanidad. De este modo, una vez conseguidos estos objetivos, nuestro estudio se centra en cómo el ser humano ha avanzado en el campo artistico del diseño, dotando de este modo a su producto de la competitividad suficiente, necesaria en un mercado cada vez más competitivo y globalizado.ABSTRACT: We try to approach, review and reflect on the purpose of packaging, which is just the one to design a suitable container to preserve and protect a product for its consumption, throughout the entire history of mankind. Thus, once these objectives have been achieved, our study focuses on how humans have advanced within the arts of design, providing its product with sufficient competitiveness, which is so necessary in an increasingly competitive and globalized market.info:eu-repo/semantics/publishedVersio

    Leveraging the Performance of LBM-HPC for Large Sizes on GPUs using Ghost Cells

    Get PDF
    Today, we are living a growing demand of larger and more efficient computational resources from the scienti c community. On the other hand, the appearance of GPUs for general purpose computing supposed an important advance for covering such demand. These devices o er an impressive computational capacity at low cost and an efficient power consumption. However, the memory available in these devices is (sometimes) not enough, and so it is necessary computationally expensive memory transfers from (to) CPU to (from) GPU, causing a dramatic fall in performance. Recently, the Lattice-Boltzmann Method has positioned as an e cient methodology for fluid simulations. Although this method presents some interesting features particularly amenable to be efficiently exploited on parallel computers, it requires a considerable memory capacity, which can suppose an important drawback, in particular, on GPUs. In the present paper, it is proposed a new GPU-based implementation, which minimizes such requirements with respect to other state-of-the-art implementations. It allows us to execute almost 2 bigger problems without additional memory transfers, achieving faster executions when dealing with large problems

    A comparative study of infrared radiance measurements by an ER-2 based radiometer and the LANDSAT 5 Thematic Mapper (TM-6)

    Get PDF
    Infrared radiance measurements were acquired from a radiometer on the NASA ER-2 during a coincident LANDSAT 5 overpass on 28 Oct. 1986 as part of the FIRE Cirrus IFO in the vicinity of Lake Michigan. A comparative study is made to infer microphysical properties of the cirrus cloud field. Radiances are derived from the image by convolving the ER-2 radiometer's effective field of view along the flight path. A multistream radiative transfer model is used to account for the differences in spectral bandwidths, 10.40 to 12.50 microns for the LANDSAT band and 9.90 to 10.87 microns for the radiometer

    Recent high resolution laboratory determinations of line broadening and intensity parameters: PH3, CH3D, and CO2

    Get PDF
    Recent unpublished laboratory work on rovibrational line strengths and broadening coefficients which is of interest in the study of planetary atmospheres was reviewed. The molecules discussed are PH3, CH3D and CO2

    Interstellar grain chemistry and the composition of comets

    Get PDF
    During the past 15 years considerable progress in observational techniques has been achieved in the middle infrared, the spectral region most diagnostic of molecular vibrations. Spectra of many different astronomical infrared sources are now available. By comparing these astronomical spectra with the spectra of lab ices, one can determine the composition and abundance of the icy materials frozen on the cold dust grains present in the interior of molecular clouds. In the experiments described, the assumption is made that cometary ices are similar to interstellar ices. As an illustration of the processes which can take place as an ice is irradiated and subsequently warmed, the infrared spectra is presented of the mixture H2O:CH3OH:CO:NH3:C6H14 (100:50:10:10:10). Apart from the last species, the ratio of these compounds is representative of the simplest ices found in interstellar clouds

    Quantitative infrared spectroscopy of minor constituents of the Earth's atmosphere

    Get PDF
    We obtain quantitative laboratory spectroscopic measurements of molecular constituents which are of importance in understanding the health of the Earth's atmosphere, and, in particular, emphasize those species which are important for understanding stratospheric kinetics or are used for long term monitoring of the stratosphere. Our measurements provide: (1) line and band intensity values which are needed to establish limits of detectability for as yet unobserved species and to quantify the abundance of those species which are observed; (2) line-positions, -half widths and pressure induced shifts are all needed for remote sensing techniques, and (3) data on the above basic molecular parameters at temperatures and pressures appropriate for the real atmosphere
    • …
    corecore