15,071 research outputs found

    Patents and Atomic Energy

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    The Realized Benefits from Bioprospecting in the Wake of the Convention on Biological Diversity

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    The emergence of methods to miniaturize in-vitro bioassays in the 1980s allowed for rapid evaluation of large numbers of plant samples with newfound efficiency. Contemporaneously, the United Nations Conference on Environment and Development (Earth Summit) fundamentally changed the legal status of ownership for biological resources, legally mandating that benefits derived from natural sources be shared in an equitable manner with the country where the species was first collected. It was expected from this reform that significant royalty payments would be paid to countries in which the species originated. However, this expectation did not hold true as few marketable discoveries were made. Despite this initial disappointment, a number of non-monetary benefits materialized, including a contribution to general knowledge, building research, development, conservation capacity, improved quality of life for rural communities, and changes in the ethical practices of international collaboration. These, as well as other advancements, will contribute to a more equitable scientific collaboration in the future

    SONTRAC—a scintillating plastic fiber tracking detector for neutron and proton imaging spectroscopy

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    SONTRAC (SOlar Neutron TRACking imager and spectrometer) is a conceptual instrument intended to measure the energy and incident direction of 20–150 MeV neutrons produced in solar flares. The intense neutron background in a low-Earth orbit requires that imaging techniques be employed to maximize an instrument’s signal-to-noise ratio. The instrument is comprised of mutually perpendicular, alternating layers of parallel, scintillating, plastic fibers that are viewed by optoelectronic devices. Two stereoscopic views of recoil proton tracks are necessary to determine the incident neutron’s direction and energy. The instrument can also be used as a powerful energetic proton imager. Data from a fully functional 3-d prototype are presented. Early results indicate that the instrument’s neutron energy resolution is approximately 10% with the neutron incident direction determined to within a few degrees

    GRO J1744-28, search for the counterpart: infrared photometry and spectroscopy

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    Using VLT/ISAAC, we detected 2 candidate counterparts to the bursting pulsar GRO J1744-28, one bright and one faint, within the X-ray error circles of XMM-Newton and Chandra. In determining the spectral types of the counterparts we applied 3 different extinction corrections; one for an all-sky value, one for a Galactic Bulge value and one for a local value. We find the local value, with an extinction law of alpha = 3.23 +- 0.01 is the only correction that results in colours and magnitudes for both bright and faint counterparts consistent with a small range of spectral types, and for the bright counterpart, consistent with the spectroscopic identification. Photometry of the faint candidate indicates it is a K7/M0 V star at a distance of 3.75 +- 1 kpc. This star would require a very low inclination angle (i < 9deg) to satisfy the mass function constraints; however it cannot be excluded as the counterpart without follow-up spectroscopy to detect emission signatures of accretion. Photometry and spectroscopy of the bright candidate indicate it is most likely a G/K III star. The spectrum does not show Br-gamma emission, a known indicator of accretion. The bright star's magnitudes are in agreement with the constraints placed on a probable counterpart by the calculations of Rappaport & Joss (1997) for an evolved star that has had its envelope stripped. The mass function indicates the counterpart should have M < 0.3 Msol for an inclination of i >= 15deg; a stripped giant, or a main sequence M3+ V star are consistent with this mass-function constraint. In both cases mass-transfer, if present, will be by wind-accretion as the counterpart will not fill its Roche lobe given the observed orbital period. The derived magnetic field of 2.4 x 10^{11} G will inhibit accretion by the propeller effect, hence its quiescent state.Comment: 12 pages, 6 figures, 4 table, MNRAS accepted Changes to the content and an increased analysis of the Galactic centre extinctio

    Garbage Collection is Fast, But a Stack is Faster

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    Prompted by claims that garbage collection can outperform stack allocation when sufficient physical memory is available, we present a careful analysis and set of cross-architecture measurements comparing these two approaches for the implementation of continuation (procedure call) frames. When the frames are allocated on a heap they require additional space, increase the amount of data transferred between memory and registers, and, on current architectures, require more instructions. We find that stack allocation of continuation frames outperforms heap allocation in some cases by almost a factor of three. Thus, stacks remain an important implementation technique for procedure calls, even in the presence of an efficient, compacting garbage collector and large amounts of memory
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