5,319 research outputs found

    Hypergolic stream impingement phenomena nitrogen tetroxide/hydrazine

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    Mechanism and design parameter effects in stream mixing and separation of nitrogen tetroxide-hydrazine impingemen

    Combustion instability prediction using a nonlinear bipropellant vaporization model

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    Combustion instability prediction using nonlinear bipropellant vaporization mode

    Cross-Border Issues in the Regulation of Charities: Experiences from the UK and Ireland

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    Drawing on the specific experiences of the three authors across the jurisdictions of England and Wales, Scotland, Northern Ireland, the Republic of Ireland, this article outlines the new legal-regulatory framework for charities in each jurisdiction, providing an overview of their respective treatments of external charities (i.e. non-domestic charities operating in a host jurisdcition) before assessing the operational challenges posted by these regimes for such cross-border charities. It shows that the treatment of external charities across the four jurisdictions in not the product of a fully coordinated and coherent joint approach by the four sets of legislators. The article concludeds by offering some preliminary recommendations intended to address the burdens caused by these overlapping regulatory systems

    Computer modeling of rocket engine ignition transients Final report

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    Computer modeling of rocket engine ignition transient

    Transients influencing rocket engine ignition and popping Interim report

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    Engine design and operating parameters studied for effects on rocket engine ignition and poppin

    The Carina Nebula and Gum 31 molecular complex: II. The distribution of the atomic gas revealed in unprecedented detail

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    We report high spatial resolution observations of the HI 21cm line in the Carina Nebula and the Gum 31 region obtained with the Australia Telescope Compact Array. The observations covered \sim 12 deg2^2 centred on l=287.5deg,b=1degl= 287.5\deg,b = -1\deg, achieving an angular resolution of \sim 35 arcseconds. The HI map revealed complex filamentary structures across a wide range of velocities. Several "bubbles" are clearly identified in the Carina Nebula Complex, produced by the impact of the massive star clusters located in this region. An HI absorption profile obtained towards the strong extragalactic radio source PMN J1032--5917 showed the distribution of the cold component of the atomic gas along the Galactic disk, with the Sagittarius-Carina and Perseus spiral arms clearly distinguishable. Preliminary calculations of the optical depth and spin temperatures of the cold atomic gas show that the HI line is opaque (τ\tau \gtrsim 2) at several velocities in the Sagittarius-Carina spiral arm. The spin temperature is 100\sim100 K in the regions with the highest optical depth, although this value might be lower for the saturated components. The atomic mass budget of Gum 31 is 35%\sim35 \% of the total gas mass. HI self absorption features have molecular counterparts and good spatial correlation with the regions of cold dust as traced by the infrared maps. We suggest that in Gum 31 regions of cold temperature and high density are where the atomic to molecular gas phase transition is likely to be occurring.Comment: 20 pages, 1 table, 16 Figures, Accepted for Publication in the Monthly Notices of the Royal Astronomical Society Journa

    Polyfire project- an example of an industrial research project promoting safe industrial production of fire-resistant nanocomposites

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    New developments based on nanotechnology have to guarantee safe products and processes to be accepted by society. The Polyfire project will develop and scale-up techniques for processing halogen-free, fire-retardant nanocomposite materials and coatings based on unsaturated polyester resins and organoclays. The project includes a work package that will assess the Health and Environmental impacts derived from the manipulation of nanoparticles. This work package includes the following tasks: (1) Identification of Health and Environment Impacts derived from the processes, (2) Experimentation to study specific Nanoparticle Emissions, (3) Development of a Risk Management Methodology for the process, and (4) A Comparison of the Health and Environmental Impact of New and Existing Materials. To date, potential exposure scenarios to nanomaterials have been identified through the development of a Preliminary Hazard Analysis (PHA) of the new production processes. In the next step, these scenarios will be studied and simulated to evaluate potential emissions of nanomaterials. Polyfire is a collaborative European project, funded by the European Commission 7th Framework Programme (Grant Agreement No 229220). It features 11 partners from 5 countries (5 SMEs, 3 research institutes, 2 large companies, 1 association) and runs for three years (1st September 2009 – 31st August 2012). This project is an example of an industrial research development which aims to introduce to the market new products promoting the safe use of nanomaterials

    Accelerated placental aging in early onset preeclampsia pregnancies identified by DNA methylation.

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    Aim: To determine whether dynamic DNA methylation changes in the human placenta can be used to predict gestational age. Materials & methods: Publicly available placental DNA methylation data from 12 studies, together with our own dataset, using Illumina Infinium Human Methylation BeadChip arrays. Results & conclusion: We developed an accurate tool for predicting gestational age of placentas using 62 CpG sites. There was a higher predicted gestational age for placentas from early onset preeclampsia cases, but not term preeclampsia, compared with their chronological age. Therefore, early onset preeclampsia is associated with placental aging. Gestational age acceleration prediction from DNA methylation array data may provide insight into the molecular mechanisms of pregnancy disorders.Benjamin T Mayne, Shalem Y Leemaqz, Alicia K Smith, James Breen, Claire T Roberts, Tina Bianco-Miott
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