Aeroelastic airfoil smart spar

Aircraft wings and rotor-blades are subject to undesirable bending and twisting excursions that arise from unsteady aerodynamic forces during high speed flight, abrupt maneuvers, or hard landings. These bending excursions can range in amplitude from wing-tip flutter to failure. A continuous-filament construction 'smart' laminated composite box-beam spar is described which corrects itself when subject to undesirable bending excursions or flutter. The load-bearing spar is constructed so that any tendency for the wing or rotor-blade to bend from its normal position is met by opposite twisting of the spar to restore the wing to its normal position. Experimental and theoretical characterization of these spars was made to evaluate the torsion-flexure coupling associated with symmetric lay-ups. The materials used were uniweave AS-4 graphite and a matrix comprised of Shell 8132 resin and U-40 hardener. Experimental tests were conducted on five spars to determine spar twist and bend as a function of load for 0, 17, 30, 45 and 60 deg fiber angle lay-ups. Symmetric fiber lay-ups do exhibit torsion-flexure couplings. Predictions of the twist and bend versus load were made for different fiber orientations in laminated spars using a spline function structural analysis. The analytical results were compared with experimental results for validation. Excellent correlation between experimental and analytical values was found

Facing diversity under institutional constraints: challenging situations for community nurses when providing care to ethnic minority patients.

AIMS: To explore the challenges faced by community nurses when providing home health care to ethnic minority patients. BACKGROUND: Norway has a growing number of immigrants, including older immigrant patients. Community nurses who provide home care encounter considerable challenges when delivering services to an increasingly diverse patient population. DESIGN: A qualitative study based on a hermeneutics approach. METHODS: A qualitative study was conducted involving 19 nurses in Norwegian home health care districts, which had high proportions of minority patients. Data were collected in 2008. FINDINGS: We identified three critical aspects of the encounters between community nurses and minority patients. The first was intimate care. Nurses perceived the fear of mistakes and crossing boundaries related to the cultural and religious practices of minority patients as particularly stressful. The second was rehabilitation after stroke. The beliefs of nurses in the benefits of rapid rehabilitation conflicted with those of the minority patients and their relatives who favoured extended rest during recovery. Third, the commitment of community nurses to transparency in the care of dying patients was tested severely when they met relatives who believed in religious explanations for the destinies of patients and who wanted to conceal the true diagnosis from terminally ill patients. CONCLUSION: Community nurses encountered various challenges due to a lack of experience with highly diverse patient populations. This situation will continue to create difficulties for nurses and minority patients if management support and appropriate training measures are not provided