Technology research for strapdown inertial experiment and digital flight control and guidance

A helicopter flight-test program to evaluate the performance of Honeywell's Tetrad - a strapdown, laser gyro, inertial navitation system is discussed. The results of 34 flights showed a mean final navigational velocity error of 5.06 knots, with a standard deviation of 3.84 knots; a corresponding mean final position error of 2.66 n.mi., with a standard deviation of 1.48 n.m.; and a modeled mean-position-error growth rate for the 34 tests of 1.96 knots, with a standard deviation of 1.09 knots. Tetrad's four-ring laser gyros provided reliable and accurate angular rate sensing during the test program and on sensor failures were detected during the evaluation. Criteria suitable for investigating cockpit systems in rotorcraft were developed. This criteria led to the development of two basic simulators. The first was a standard simulator which could be used to obtain baseline information for studying pilot workload and interactions. The second was an advanced simulator which integrated the RODAAS developed by Honeywell into this simulator. The second area also included surveying the aerospace industry to determine the level of use and impact of microcomputers and related components on avionics systems

Lived experiences of multimorbidity: an interpretative meta-synthesis of patients', general practitioners' and trainees' perceptions

OBJECTIVES: Multimorbidity is an increasing challenge. Better understanding of lived experiences of patients, general practitioners and trainees, may advance patient care and medical education. This interpretative meta-synthesis sought to (i) understand lived experiences of patients, general practitioners and trainees regarding multimorbidity, (ii) identify how similarities and differences in experiences should shape future solutions. METHODS: Empirical studies containing qualitative data and pertaining to lived experiences from our recent realist synthesis (PROSPERO 2013:CRD42013003862) were included. Following quality assessment, data were extracted from key studies to build an integrated analytic framework. Data from remaining studies were utilised to expand and refine the framework through thematic analysis of concepts within and between perspectives. RESULTS: Twenty-one papers were included in the meta-synthesis. Analysis of 70 concepts produced five themes: (1) goals of care and decision making, (2) complexity, (3) meeting expectations, (4) logistics and (5) interpersonal dynamics. The complexities of multimorbidity lead to shared feelings of vulnerability, uncertainty and enforced compromises. Barriers to optimal care-education included system constraints, inadequate continuity and role uncertainty. DISCUSSION: There was little evidence of shared discussion of these challenges. Addressing these issues and more explicit exploration of the experiences of each group during interactions may improve delivery and satisfaction in care and education

Differential chemical abundance analysis of a 47 Tuc AGB star with respect to Arcturus

This study resolves a discrepancy in the abundance of Zr in the 47 Tucanae asymptotic giant branch star Lee 2525. This star was observed using the echelle spectrograph on the 2.3 m telescope at Siding Spring Observatory. The analysis was undertaken by calibrating Lee 2525 with respect to the standard giant star Arcturus. This work emphasises the importance of using a standard star with stellar parameters comparable to the star under analysis rather than a calibration with respect to the Sun (Koch & McWilliam 2008). Systematic errors in the analysis process are then minimised due to the similarity in atmospheric structure between the standard and programme stars. The abundances derived for Lee 2525 were found to be in general agreement with the Brown & Wallerstein (1992) values except for Zr. In this study Zr has a similar enhancement ([Zr/Fe] = +0.51 dex) to another light s-process element, Y ([Y/Fe] = +0.53 dex), which reflects current theory regarding the enrichment of s-process elements by nuclear processes within AGB stars (Busso et al. 2001). This is contrary to the results of Brown & Wallerstein (1992) where Zr was under-abundant ([Zr/Fe] = +0.51 dex) and Y was over-abundant ([Y/Fe] = +0.50 dex) with respect to Fe.Comment: 11 pages, 5 figures Accepted for publication in MNRA

Variations in Fe\u3csup\u3e3+\u3c/sup\u3e/∑Fe of Mariana Arc Basalts and Mantle Wedge \u3cem\u3ef\u3c/em\u3eO\u3csub\u3e2\u3c/sub\u3e

Arc basalts are more oxidized than mid-ocean ridge basalts, but it is unclear whether this difference is due to differentiation processes in the Earth’s crust or to a fundamental difference in the oxygen fugacity of their mantle sources. Distinguishing between these two hypotheses is important for understanding redox-sensitive processes related to arc magmatism, and thus more broadly how Earth materials cycle globally. We present major, volatile, and trace element concentrations in combination with Fe3+/∑Fe ratios determined in olivine-hosted glass inclusions and submarine glasses from five Mariana arc volcanoes and two regions of the Mariana Trough. For single eruptions, Fe3+/∑Fe ratios vary along liquid lines of descent that are either slightly oxidizing (olivine + clinopyroxene + plagioclase fractionation, CO2 ± H2O degassing) or reducing (olivine + clinopyroxene + plagioclase ± magnetite fractionation, CO2 + H2O + S degassing). Mariana samples are consistent with a global relationship between calc-alkaline affinity and both magmatic H2O and magmatic oxygen fugacity, where wetter, higher oxygen fugacity magmas display greater affinity for calc-alkaline differentiation. We find, however, that low-pressure differentiation cannot explain the majority of variations observed in Fe3+/∑Fe ratios for Mariana arc basalts, requiring primary differences in magmatic oxygen fugacity. Calculated oxygen fugacities of primary mantle melts at the pressures and temperatures of melt segregation are significantly oxidized relative to mid-ocean ridge basalts (∼QFM, where QFM is quartz–fayalite–magnetite buffer), ranging from QFM + 1·0 to QFM + 1·6 for Mariana arc basalts, whereas back-arc related samples record primary oxygen fugacities that range from QFM + 0·1 to QFM + 0·5. This Mariana arc sample suite includes a diversity of subduction influences, from lesser influence of a homogeneous H2O-rich component in the back-arc, to sediment melt- and fluid-dominated influences along the arc. Primary melt oxygen fugacity does not correlate significantly with sediment melt contributions (e.g. Th/La), nor can it be attributed to previous melt extraction in the back-arc. Primary melt oxygen fugacity correlates strongly with indices of slab fluids (e.g. Ba/La) from the Mariana Trough through the Mariana arc, increasing by 1·5 orders of magnitude as Ba/La increases by a factor of 10 relative to mid-ocean ridge basalts. These results suggest that contributions from the slab to the mantle wedge may be responsible for the elevated oxygen fugacity recorded by Mariana arc basalts and that slab fluids are potentially very oxidized