4,530 research outputs found

    A small-scale test for fiber release from carbon composites

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    A test method was developed to determine relative fiber loss from pyrolyzed composites with different resins and fiber construction. Eleven composites consisting of woven and unwoven carbon fiber reinforcement and different resins were subjected to the burn and impact test device. The composites made with undirectional tape had higher fiber loss than those with woven fabric. Also, the fiber loss was inversely proportional to the char yield of the resin

    Fiber-modified polyurethane foam for ballistic protection

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    Closed-cell, semirigid, fiber-loaded, self-extinguishing polyurethane foam material fills voids around fuel cells in aircraft. Material prevents leakage of fuel and spreading of fire in case of ballistic incendiary impact. It also protects fuel cell in case of exterior fire

    Andersen-Tawil Syndrome

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    Andersen-Tawil syndrome (ATS) is a rare condition consisting of ventricular arrhythmias, periodic paralysis, and dysmorphic features. In 2001, mutations in KCNJ2, which encodes the α subunit of the potassium channel Kir2.1, were identified in patients with ATS. To date, KCNJ2 is the only gene implicated in ATS, accounting for approximately 60% of cases. ATS is a unique channelopathy, and represents the first link between cardiac and skeletal muscle excitability. The arrhythmias observed in ATS are distinctive; patients may be asymptomatic, or minimally symptomatic despite a high arrhythmia burden with frequent ventricular ectopy and bidirectional ventricular tachycardia. However, patients remain at risk for life-threatening arrhythmias, including torsades de pointes and ventricular fibrillation, albeit less commonly than observed in other genetic arrhythmia syndromes. The characteristic heterogeneity at both the genotypic and phenotypic levels contribute to the continued difficulties with appropriate diagnosis, risk stratification, and effective therapy. The initial recognition of a syndromic association of clinically diverse symptoms, and the subsequent identification of the underlying molecular genetic basis of ATS has enhanced both clinical care, and our understanding of the critical function of Kir2.1 on skeletal muscle excitability and cardiac action potentia

    Intumescent Coatings as Fire Retardants

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    Fire-retardant paint, when activated by the heat of fire, reacts to form a thick, low-density, polymeric coating or char layer. Water vapor and sulphur dioxide are released during the intumescent reaction

    Aberrational Effects for Shadows of Black Holes

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    In this paper, we discuss how the shadow of a Kerr black hole depends on the motion of the observer. In particular, we derive an analytical formula for the boundary curve of the shadow for an observer moving with given four-velocity at given Boyer--Lindquist coordinates. We visualize the shadow for various values of parameters.Comment: 12 pages, 3 figures; Proceedings of the 524. WE-Heraeus-Seminar held at the Physikzentrum, Bad Honnef, Germany, 17.--23.2.201

    When the clinic is not yet built … the Avian Park Service Learning Centre story

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    The Ukwanda Centre for Rural Health (UCRH) opened in 2001, followed 10 years later by the establishment of the Ukwanda Rural Clinical School in one of the rural health districts of the Western Cape. This paper relates the journey of the Faculty with the underserviced community of Avian Park through the provision of healthcare services aimed at addressing needs identified by the local community. It attempts to substantiate the meaning of the word Ukwanda, translated ‘to grow’ and ‘develop within the community’ in order to reach the primary goal of being an ‘engaged institution’. The Avian Park Service Learning Centre (APSLC) is the culmination of the aspirations of a number of stakeholders who wanted to respond to the community needs for access to basic healthcare while providing learning opportunities for students. Initially only patients with chronic diseases of lifestyle, tuberculosis (TB) and HIV/AIDS were seen by community care-workers (CCWs). Through a number of service-learning initiatives in Avian Park, a variety of health services have developed in the community. CCWs have become teachers, community developers and an integral part of the health service team. They enhance access to the residents, community projects and networking within the community.The APSLC improves the opportunities to integrate theoretical academic work with practical application, providing students with a unique opportunity to be involved in healthcare service design and development (as active participants, not observers) based on community-identified needs. University and community collaboration has been purposeful and aims to strengthen community engagement, while up-skilling residents and affording community-based education opportunities for health professions

    Methanol masers probing the ordered magnetic field of W75N

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    The role of magnetic fields during the protostellar phase of high-mass star-formation is a debated topic. In particular, it is still unclear how magnetic fields influence the formation and dynamic of disks and outflows. Most current information on magnetic fields close to high-mass protostars comes from H2O and OH maser observations. Recently, the first 6.7 GHz methanol maser polarization observations were made, and they reveal strong and ordered magnetic fields. The morphology of the magnetic field during high-mass star-formation needs to be investigated on small scales, which can only be done using very long baseline interferometry observations. The massive star-forming regionW75N contains three radio sources and associated masers, while a large-scale molecular bipolar outflow is also present. Polarization observations of the 6.7 GHz methanol masers at high angular resolution probe the strength and structure of the magnetic field and determine its relation to the outflow. Eight of the European VLBI network antennas were used to measure the linear polarization and Zeeman-splitting of the 6.7 GHz methanol masers in the star-forming region W75N. We detected 10 methanol maser features, 4 of which were undetected in previous work. All arise near the source VLA1 of W75N. The linear polarization of the masers reveals a tightly ordered magnetic field over more than 2000 AU around VLA1 that is exactly aligned with the large-scale molecular outflow. This is consistent with the twisted magnetic field model proposed for explaining dust polarization observations. The Zeeman-splitting measured on 3 of the maser features indicates a dynamically important magnetic field in the maser region of the order of 50mG. We suggest VLA1 is the powering sources of the bipolar outflow.Comment: 5 pages, 3 figures, accepted by Astronomy and Astrophysic

    Adverse Health Effects of Spousal Violence Among Women Attending Saudi Arabian Primary Health-Care Clinics

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    This study aimed to investigate the frequency of spousal violence among Saudi women and document the related health effects and injuries, as well as their attitudes to gender and violence. Structured interviews were conducted with 200 ever-married women recruited from primary-care centres in Jeddah. Nearly half of the surveyed women (44.5%) reported ever experiencing physical violence from their spouse. Although 37 women (18.5%) had received violence-related injuries, only 6.5% had reported these injuries to a health-care provider. Victims of spousal violence had poor perceptions of their overall health, and reported pain or discomfort, antidepressant use and suicidal thoughts. Women mostly disagreed with the presented justifications for wife beating. However, the association between gender attitudes and spousal violence was not significant. The results of this study support calls for integration of education about partner violence into health care curricula to enhance the access and quality of services

    Global surfaces of section in the planar restricted 3-body problem

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    The restricted planar three-body problem has a rich history, yet many unanswered questions still remain. In the present paper we prove the existence of a global surface of section near the smaller body in a new range of energies and mass ratios for which the Hill's region still has three connected components. The approach relies on recent global methods in symplectic geometry and contrasts sharply with the perturbative methods used until now.Comment: 11 pages, 1 figur

    Lesbian and bisexual women's human rights, sexual rights and sexual citizenship: negotiating sexual health in England.

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    Lesbian and bisexual women's sexual health is neglected in much Government policy and practice in England and Wales. This paper examines lesbian and bisexual women's negotiation of sexual health, drawing on findings from a small research project. Themes explored include invisibility and lack of information, influences on decision-making and sexual activities and experiences of services and barriers to sexual healthcare. Key issues of importance in this respect are homophobic and heterosexist social contexts. Drawing on understandings of lesbian, gay and bisexual human rights, sexual rights and sexual citizenship, it is argued that these are useful lenses through which to examine and address lesbian and bisexual women's sexual health and related inequalities
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