13,542 research outputs found

    Some developments in the feeding of coal to fluidized bed combustors

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    Research is being done in the development of fluid bed combustors for high sulphur coal, using limestone or dolomite in the bed for removal of the sulphur. Operating units to date have proven the inadequacies of available material handling techniques for introduction and control of the coal and adsorbent to the beds. Larger units now being contemplated will pose formidable problems in this area. Some of the techniques which were developed for the existing pilot units and novel ideas under consideration for future, large production units are illustrated and described

    LISA For Cosmologists: Calculating The Signal-To-Noise Ratio For Stochastic And Deterministic Sources

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    We present the steps to forecast the sensitivity of the Laser Interferometer Space Antenna (LISA) to both a stochastic gravitational wave background and deterministic wave sources. We show how to use these expressions to estimate the precision with which LISA can determine parameters associated with these sources. Tools are included to enable easy calculation of the signal-to-noise ratio and draw sensitivity curves. Benchmark values are given for easy comparison and checking of methods in the case of three worked examples. The first benchmark is the threshold stochastic gravitational wave background ΩGWh2 that LISA can observe. The second is the signal-to-noise ratio that LISA would observe for a binary black hole system identical to GW150914, radiating four years before merger. The third is the case of a monotone source, such as a binary that is far from merger

    LISA For Cosmologists: Calculating The Signal-To-Noise Ratio For Stochastic And Deterministic Sources

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    We present the steps to forecast the sensitivity of the Laser Interferometer Space Antenna (LISA) to both a stochastic gravitational wave background and deterministic wave sources. We show how to use these expressions to estimate the precision with which LISA can determine parameters associated with these sources. Tools are included to enable easy calculation of the signal-to-noise ratio and draw sensitivity curves. Benchmark values are given for easy comparison and checking of methods in the case of three worked examples. The first benchmark is the threshold stochastic gravitational wave background ΩGWh2 that LISA can observe. The second is the signal-to-noise ratio that LISA would observe for a binary black hole system identical to GW150914, radiating four years before merger. The third is the case of a monotone source, such as a binary that is far from merger

    Tropidosteptes forestierae (Hemiptera: Heteroptera: Miridae: Mirinae): a new species of Plant Bug injuring ornamental Florida Swampprivet, Forestiera segregata (Oleaceae), in South Florida

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    The mirine plant bug Tropidosteptes forestierae, new species (Hemiptera: Miridae) is described from Collier County, Florida, where it was found causing serious injury to an extensive ornamental hedge of Florida swampprivet, Forestiera segregata (Jacq.) Krug and Urb. (Oleaceae). Adult male and female, fifth instar, and egg are described. Color images of the adults, nymph, egg, and injury; scanning photomicrographs of selected adult structures; and illustrations of male genitalia are provided. A key to help distinguish the 16 species of Tropidosteptes known to occur in the southeastern United States is given

    Recent data indicate that black women are at greater risk of severe morbidity and mortality from postpartum haemorrhage, both before and after adjusting for comorbidity.

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    Recent data indicate that black women are at greater risk of severe morbidity and mortality from postpartum haemorrhage, both before and after adjusting for comorbidity. Causes of increased risk of severe morbidity and mortality related to postpartum haemorrhage in black women in the USA are poorly understood and warrant further research. There is a need for tailored maternity services and improved access to care for women from ethnic minorities

    Hammett Correlations in the \u3csup\u3e1\u3c/sup\u3eH NMR Spectra of Some N-Arlydihalonicotinamides

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    Excellent linear correlations of amide proton chemical shifts (Snh) (in DMSO-d6 ) with Hammett substituent constants (5) for a series of 4-substituted anilides of four dihalonicotinic acid systems were observed. Dihalonicotinanilides with chlorine in the pyridine 2 - position exhibited a more positive slope in a Hammett plot of S^H vs - aR- where R is the substituent in the 4 position of the benzene ring. This observation is explained in terms of the inductive effect of chlorine which results in a slightly more acidic amide proton, which in turn causes an enhanced hydrogen bonding tendency to solvent. Four disubstituted anilides were also prepared, and the 5NH of these derivatives correlated well with the additive value of the 6R\u27s of the two substituents

    The oldest known snakes from the Middle Jurassic-Lower Cretaceous provide insights on snake evolution

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    The previous oldest known fossil snakes date from ∼100 million year old sediments (Upper Cretaceous) and are both morphologically and phylogenetically diverse, indicating that snakes underwent a much earlier origin and adaptive radiation. We report here on snake fossils that extend the record backwards in time by an additional ∼70 million years (Middle Jurassic-Lower Cretaceous). These ancient snakes share features with fossil and modern snakes (for example, recurved teeth with labial and lingual carinae, long toothed suborbital ramus of maxillae) and with lizards (for example, pronounced subdental shelf/gutter). The paleobiogeography of these early snakes is diverse and complex, suggesting that snakes had undergone habitat differentiation and geographic radiation by the mid-Jurassic. Phylogenetic analysis of squamates recovers these early snakes in a basal polytomy with other fossil and modern snakes, where Najash rionegrina is sister to this clade. Ingroup analysis finds them in a basal position to all other snakes including Najash.Fil: Caldwell, Michael Wayne. University of Alberta; CanadáFil: Nydam, Randall L.. Department Of Anatomy, Midwestern University, Glendale; Estados UnidosFil: Palci, Alessandro. South Australian Museum. Earth Sciences Section; AustraliaFil: Apesteguía, Sebastián. Fundación de Historia Natural Félix de Azara; Argentina. Universidad Maimónides. Área de Investigaciones Biomédicas y Biotecnológicas. Centro de Estudios Biomédicos, Biotecnológicos, Ambientales y de Diagnóstico; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

    Using a Primordial Gravitational Wave Background to Illuminate New Physics

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    A primordial spectrum of gravitational waves serves as a backlight to the relativistic degrees of freedom of the cosmological fluid. Any change in the particle physics content, due to a change of phase or freeze-out of a species, will leave a characteristic imprint on an otherwise featureless primordial spectrum of gravitational waves and indicate its early-Universe provenance. We show that a gravitational wave detector such as the Laser Interferometer Space Antenna would be sensitive to physics near 100 TeV in the presence of a sufficiently strong primordial spectrum. Such a detection could complement searches at newly proposed 100 km circumference accelerators such as the Future Circular Collider at CERN and the Super Proton-Proton Collider in China, thereby providing insight into a host of beyond Standard Model issues, including the hierarchy problem, dark matter, and baryogenesis.Comment: 7 pages, 3 figures; added reference

    Involving users in service planning: a focus group approach

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    This paper outlines the way in which a focus group approach was used to involve service users in the possible reconfiguration of follow-up services for breast cancer patients at a North London hospital. The focus group was used to identify the priority issues for users and the development of an objective questionnaire, to survey all current service users. Within the National Health Service (NHS) the concept of user involvement has been embodied in contemporary health policy, and has become an important constituent of current policy direction. This study was the first stage of a larger stakeholder project that aimed to involve service users and clinicians in developing a new model of breast cancer follow-up service. From the focus group emerged five key themes around breast cancer follow up. They were: • The need for reassurance after the diagnosis of cancer. • Continuity of care. • Privacy and dignity and other elements of the examination technique. • Information and the detection of new symptoms. • The opportunity to discuss feelings and worries. In this paper, the nature of breast cancer follow-up services is outlined, and the difficulties associated with such services are discussed. The background to user involvement within the United Kingdom is explored, and the strategies that have previously been used are considered. The practical issues involved in using the focus group approach are examined, and the experience of using such an approach is outlined in this study. The involvement of service users as a key stakeholder in the process of planning change, through a participatory research strategy, ensured that their voices were heard alongside those of both hospital and primary care staff
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