411 research outputs found

    Ten Years of Solar Change as Monitored by SBUV and SBUV/2

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    Observations of the Sun by the Solar Backscatter Ultraviolet (SBUV) instrument aboard Nimbus 7 and the SBUV/2 instrument aboard NOAA-9 reveal variations in the solar irradiance from 1978, to 1988. The maximum to minimum solar change estimated from the Heath and Schlesinger Mg index and wavelength scaling factors is about 4 percent from 210 to 260 nm and 8 percent for 180 to 210 nm; direct measurements of the solar change give values of 1 to 3 percent and 5 to 7 percent, respectively, for the same wavelength range. Solar irradiances were high from the start of observations, late in 1978, until 1983, declined until early 1985, remained approximately constant until mid-1987, and then began to rise. Peak-to-peak 27-day rotational modulation amplitudes were as large as 6 percent at solar maximum and 1 to 2 percent at solar minimum. During occasional intervals of the 1979 to 1983 maximum and again during 1988, the dominant rotational modulation period was 13.5 days. Measurements near 200 to 205 nm show the same rotational modulation behavior but cannot be used to track long-term changes in the Sun because of uncertainties in the characterization of long-term instrument sensitivity changes

    Nimbus-7 Scanning Multichannel Microwave Radiometer (SMMR) PARM tape user's guide

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    The Scanning Multichannel Microwave Radiometer (SMMR) instrument, onboard the Nimbus-7 spacecraft, collected data from Oct. 1978 until Jun. 1986. The data were processed to physical parameter level products. Geophysical parameters retrieved include the following: sea-surface temperatures, sea-surface windspeed, total column water vapor, and sea-ice parameters. These products are stored on PARM-LO, PARM-SS, and PARM-30 tapes. The geophysical parameter retrieval algorithms and the quality of these products are described for the period between Nov. 1978 and Oct 1985. Additionally, data formats and data availability are included

    A status report on the analysis of the NOAA-9 SBUV/2 sweep mode solar irradiance data

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    Monitoring of the near ultraviolet (UV) solar irradiance is important because the solar UV radiation is the primary energy source in the upper atmosphere. The solar irradiance at wavelengths shortward of roughly 300 nm heats the stratosphere via photodissociation of ozone in the Hartley bands. Shortward of 242 nm the solar UV flux photodissociates O2, which is then available for ozone formation. Upper stratosphere ozone variations coincident with UV solar rotational modulation have been previously reported (Gille et al., 1984). Clearly, short and long term solar irradiance observations are necessary to separate solar-forced ozone variations from anthropogenic changes. The SBUV/2 instrument onboard the NOAA-9 spacecraft has made daily measurements of the solar spectral irradiance at approximately 0.15 nm intervals in the wavelength region 160-405 nm at 1 nm resolution since March 1985. These data are not needed to determine the terrestrial ozone overburden or altitude profile, and hence are not utilized in the NOAA Operational Ozone Product System (OOPS). Therefore, assisted by the ST System Corporation, NASA has developed a scientific software system to process the solar sweep mode data from the NOAA-9 instrument. This software will also be used to process the sweep mode solar irradiance data from the NOAA-11 and later SBUV/2 instruments. An overview of the software system and a brief discussion of analysis findings to date are provided. Several outstanding concerns/problems are also presented

    Cross-Cultural Variations in Naïve Psychology among 2-year-olds: A Comparison of Children in the United Kingdom and Singapore

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    Children's understanding of naïve psychology is the main focus of this study. Research evidence suggests that 2- and 3-year-olds understand some aspects of naïve psychology. By 4 years, they develop internal representations of mental states. Previous studies have also reported cross-cultural variations in naïve psychology development. The majority of this research has focused on Western individualistic societies such as Australia, Europe and North America, and Eastern collectivism societies such as China and Japan. Singapore with its blend of Eastern and Western values represents a unique case for comparison with Western societies. This paper reports a cross-cultural study of young children's developing understanding of naïve psychology in Edinburgh, UK and Singapore. It addresses three main questions: (a) Are there cross-cultural differences in the development of naïve psychology?; (b) What are children's performance sequences on naïve psychology tasks?; and (c) Are naïve psychology concepts coherent? The participants were 87 children from the UK (n=43, mean age 2 years 4 months) and Singapore (n=44, mean age 2 years 5 months). This study incorporated several established tasks of pretence, desires, emotions, perceptions, appearance-reality and false-beliefs to investigate children's understanding of non-representational and representational mental states. The results showed no gross cross-cultural differences. However, significant cultural differences in performance on two tasks and differences in the coherence of naïve psychology concepts were identified. The results highlight the importance of considering subtle cultural influences on children's developing understanding of various aspects of naïve psychology. © 2010 Brill

    Non-optical Imaging of Flow, Boiling, and Salt Deposition in a Simulated Debris Bed

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    Determining flow and heat transfer characteristics in a debris bed or a packed bed is difficult due to the lack of optical access. Non-optical imaging methods, such as x-ray or neutron imaging, can be used to observe flow characteristics and particle deposition, as well as boiling in a packed bed. An amorphous Silicon detector based digital radiography camera can be used to image with either x-rays or neutrons at up to 100 frames per second. The digital radiography camera, coupled with digital image analysis techniques was used to characterize fluid fraction and flow rates in a simulated debris bed. A water percolation experiment was performed where a test section filled with 1-3 mm glass particles was used as a simulated debris bed, and properties such as packing fraction, volumetric flow rate, and evaporation rate were calculated both physically and using data from the images. The values obtained using the images were benchmarked against the physically calculated values and found to be in agreement, validating the image processing algorithms

    Performance evaluation of the solar backscatter ultraviolet radiometer, model 2 (SBUV/2) inflight calibration system

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    The Solar Backscatter Ultraviolet Radiometer, Model 2 (SBUV/2) instruments, as part of their regular operation, deploy ground aluminum reflective diffusers to deflect solar irradiance into the instrument's field-of-view. Previous SBUV instrument diffusers have shown a tendency to degrade in their reflective efficiencies. This degradation will add a trend to the ozone measurements if left uncorrected. An extensive in-flight calibration system was designed into the SBUV/2 instruments to effectively measure the degradation of the solar diffuser (Ball Aerospace Systems Division 1981). Soon after launch, the NOAA-9 SBUV/2 calibration system was unable to track the diffuser's reflectivity changes due, in part, to design flows (Frederick et al. 1986). Subsequently, the NOAA-11 SBUV/2 calibration system was redesigned and an analysis of the first 2 years of data (Weiss et al. 1991) indicated the NOAA-11 SBUV/2 onboard calibration system's performance to be exceeding preflight expectations. This paper will describe the analysis of the first three years NOAA-11 SBUV/2 calibration system data

    Nimbus 7 solar backscatter ultraviolet (SBUV) ozone products user's guide

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    Three ozone tape products from the Solar Backscatter Ultraviolet (SBUV) experiment aboard Nimbus 7 were archived at the National Space Science Data Center. The experiment measures the fraction of incoming radiation backscattered by the Earth's atmosphere at 12 wavelengths. In-flight measurements were used to monitor changes in the instrument sensitivity. Total column ozone is derived by comparing the measurements with calculations of what would be measured for different total ozone amounts. The altitude distribution is retrieved using an optimum statistical technique for the inversion. The estimated initial error in the absolute scale for total ozone is 2 percent, with a 3 percent drift over 8 years. The profile error depends on latitude and height, smallest at 3 to 10 mbar; the drift increases with increasing altitude. Three tape products are described. The High Density SBUV (HDSBUV) tape contains the final derived products - the total ozone and the vertical ozone profile - as well as much detailed diagnostic information generated during the retrieval process. The Compressed Ozone (CPOZ) tape contains only that subset of HDSBUV information, including total ozone and ozone profiles, considered most useful for scientific studies. The Zonal Means Tape (ZMT) contains daily, weekly, monthly and quarterly averages of the derived quantities over 10 deg latitude zones

    Social cognition in children with Down's syndrome: challenges to research and theory building

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    Characterising how socio-cognitive abilities develop has been crucial to understanding the wider development of typically developing children. It is equally central to understanding developmental pathways in children with intellectual disabilities such as Down's syndrome. While the process of acquisition of socio-cognitive abilities in typical development and in autism has received considerable attention, socio-cognitive development in Down's syndrome has received far less scrutiny. Initial work in the 1970s and 1980s provided important insights into the emergence of socio-cognitive abilities in the children's early years, and recently there has been a marked revival of interest in this area, with research focusing both on a broader range of abilities and on a wider age range. This annotation reviews some of these more recent findings, identifies outstanding gaps in current understanding, and stresses the importance of the development of theory in advancing research and knowledge in this field. Barriers to theory building are discussed and the potential utility of adopting a transactional approach to theory building illustrated with reference to a model of early socio-cognitive development in Down's syndrome. The need for a more extensive model of social cognition is emphasised, as is the need for larger-scale, finer-grained, longitudinal work which recognises the within-individual and within-group variability which characterises this population. The value of drawing on new technologies and of adapting innovative research paradigms from other areas of typical and atypical child psychology is also highlighted

    Calculation of the properties of the rotational bands of 155,157^{155,157}Gd

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    We reexamine the long-standing problem of the microscopic derivation of a particle-core coupling model. We base our research on the Klein-Kerman approach, as amended by D\"onau and Frauendorf. We describe the formalism to calculate energy spectra and transition strengths in some detail. We apply our formalism to the rotational nuclei 155,157^{155,157}Gd, where recent experimental data requires an explanation. We find no clear evidence of a need for Coriolis attenuation.Comment: 27 pages, 13 uuencoded postscript figures. Uses epsf.st

    Derivation and assessment of strong coupling core-particle model from the Kerman-Klein-D\"onau-Frauendorf theory

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    We review briefly the fundamental equations of a semi-microscopic core-particle coupling method that makes no reference to an intrinsic system of coordinates. We then demonstrate how an intrinsic system can be introduced in the strong coupling limit so as to yield a completely equivalent formulation. It is emphasized that the conventional core-particle coupling calculation introduces a further approximation that avoids what has hitherto been the most time-consuming feature of the full theory, and that this approximation can be introduced either in the intrinsic system, the usual case, or in the laboratory system, our preference. A new algorithm is described for the full theory that largely removes the difference in complexity between the two types of calculation. Comparison of the full and approximate theories for some representative cases provides a basis for the assessment of the accuracy of the traditional approach. We find that for well-deformed nuclei, e.g. 157Gd and 157Tb, the core-coupling method and the full theory give similar results.Comment: revtex, 3 figures(postscript), submitted to Phys.Rev.
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