112 research outputs found

    First results of material charging in the space environment

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    A satellite experiment, designed to measure potential charging of typical thermal control materials at near geosynchronous altitude, was flown as part of the SCATHA program. Direct observations of charging of typical satellite materials in a natural charging event ( 5 keV) are presented. The results show some features which differ significantly from previous laboratory simulations of the environment

    MeV magnetosheath ions energized at the bow shock

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    A causal relationship between midlatitude magnetosheath energetic ions and bow shock magnetic geometry was previously established for ion energy up to 200 keV e−1 for the May 4, 1998, storm event. This study demonstrates that magnetosheath ions with energies above 200 keV up to 1 MeV simply extend the ion spectrum to form a power law tail. Results of cross-correlation analysis suggest that these ions also come directly from the quasi-parallel bow shock, not the magnetosphere. This is confirmed by a comparison of energetic ion fluxes simultaneously measured in the magnetosheath and at the quasi-parallel bow shock when both regions are likely connected by the magnetic field lines. We suggest that ions are accelerated at the quasi-parallel bow shock to energies as high as 1 MeV and subsequently transported into the magnetosheath during this event

    Simultaneous determination of natural and synthetic steroid estrogens and their conjugates in aqueous matrices by liquid chromatography / mass spectrometry

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    An analytical method for the simultaneous determination of nine free and conjugated steroid estrogens was developed with application to environmental aqueous matrices. Solid phase extraction (SPE) was employed for isolation and concentration, with detection by liquid chromatography/mass spectrometry (LC/MS) using electrospray ionisation (ESI) in the negative mode. Method recoveries for various aqueous matrices (wastewater, lake and drinking water) were determined, recoveries proving to be sample dependent. When spiked at 50 ng/l concentrations in sewage influent, recoveries ranged from 62-89 % with relative standard deviations (RSD) < 8.1 %. In comparison, drinking water spiked at the same concentrations had recoveries between 82-100 % with an RSD < 5%. Ion suppression is a known phenomenon when using ESI; hence its impact on method recovery was elucidated for raw sewage. Both ion suppression from matrix interferences and the extraction procedure has bearing on the overall method recovery. Analysis of municipal raw sewage identified several of the analytes of interest at ng/l concentrations, estriol (E3) being the most abundant. Only one conjugate, estrone 3-sulphate (E1-3S) was observe

    THE GENUS HYPOGLOSSUM KÜTZING (DELESSERIACEAE, RHODOPHYTA) IN THE TROPICAL WESTERN ATLANTIC, INCLUDING H. ANOMALUM SP. NOV. 1

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    Observations are made on the occurrence and distribution of the red algal genus Hypoglossum KÜtzing (Delesseriaceae, Ceramiales) in the tropical western Atlantic. In addition to the type of the genus, H. hypoglossoides (Stackh.) Coll. & Herv., three other species are reported: H. anomalum sp. nov., H. involvens (Harv.) J. Ag., and H. tenuifolium (Harv.) J. Ag. A key is presented to distinguish these four species. The newly described species, H. anomalum, is like other species in the genus in that its branches arise endogenously from the primary axial row but it is unique in that the branches emerge from the parent blade at some point between the midline and the margin of the blade. The new species is reported from Puerto Rico and Florida.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/65648/1/j.1529-8817.1986.tb04162.x.pd

    The Regulatory Gift: Politics, regulation and governance

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    Abstract: This article introduces the ‘regulatory gift’ as a conceptual framework for understanding a particular form of government-led deregulation that is presented as central to the public interest. Contra to theories of regulatory capture, government corruption, ‘insider’ personal interest or profit-seeking theories of regulation, the regulatory gift describes reform which is overtly designed by Government to reduce or reorient regulators’ functions to the advantage of the regulated and in line with market objectives on a potentially macro (rather than industry-specific) scale. As a conceptual framework, the regulatory gift is intended to be applicable across regulated sectors of democratic states and in this article the empirical sections evidence the practice of regulatory gifting in contemporary UK politics. Specifically, this article analyses the UK Public Bodies Act (2011), affecting some 900 regulatory public bodies and its correlative legislation, the Regulator’s Code (2014), the Deregulation Act (2015) and the Enterprise Bill (2016). The article concludes that whilst the regulatory gift may, in some cases, be aligned with the public interest - delivering on cost reduction, enhancing efficiency and stimulating innovation - this will not always be the case. As the case study of the regulatory body, the UK Human Fertilisation and Embryology Authority (HFEA) demonstrates, despite the explicit claims made by legislators, the regulatory gift has the potential to significantly undermine the public interest

    Wave Propagation in Lossy Warm Magnetoplasma

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