2,280 research outputs found

    Impact perforation testing of stab-resistant armour materials

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    This paper describes the development of a method for the investigation and comparison of materials for use in stab resistant body armour. A number of polymer composite panels of different thicknesses and construction have been tested. A dynamic test which simulated the real threat has been used and the results compared to a simpler quasi-static test that might be used in initial materials selection. The materials tested were glass-epoxy, and glass-nylon composite panels of several thicknesses between 1.8 and 5.8mm. Additional tests were also performed on similar composites containing tungsten wires. An accelerated instrumented drop-tower was used to drive a knife through composite panels and record the force resisting penetration by the knife. The final penetration of the knife through the armour into a soft backing was also measured. For comparison,a similar geometry quasi-static test was carried out on the same specimens. It was found that energy absorbtion took the form of an initial resistance to perforation and then by a resistance to further penetration. This is thought to stem from resistance to cutting ofthe panel material and gripping of the knife blade. The energy required to produce a given penetration in dynamic tests was found to be in good agreement with the penetration achieved at similar energies under quasi-static conditions. For the materials tested there was no significant difference between the penetration resistance of single or two layer systems. The penetration achieved through a panel of a given material was approximately proportional to the inverse square of the panel's thickness. The relative performance of different armour materials was assessed by plotting the energy required to penetrate a fixed distance against the areal density of the panel

    The Local Dimension of Energy

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    In this paper, we postulate that some of the best opportunities for reducing energy demand and carbon emissions are through stronger involvement and leadership from local government. We show that local government can and do have a significant impact on both energy production and energy consumption and are important participants for the implementation of distributed generation (DG). the progress being made by successful local governments can be narrowed to three key factors. First, they have all recognised the co-benefits of a local energy strategy: a reduction in fuel poverty, increased employment, improved quality of life and mitigation of uncertain fuel supplies and prices. Secondly, successful councils have strong political leadership and employee support to implement the structural change to bring about change. Thirdly, leading councils have gained momentum by working in partnership with utilities, private companies, NGO’s, DNO’s and government departments to raise finance and garner support. While climate change remains a global issue, some of the best strategies for mitigation are implemented at the local level
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