Experimental Investigation of a Morphing Nacelle Ducted Fan

The application of Circulation Control to the nacelle of a shrouded fan is proposed as a means to enhance off-design performance of the shrouded fan. Typically, a fixed geometry shroud is efficient at a single operating condition. Modifying circulation about the fixed geometry is proposed as a means to virtually morph the shroud without moving surfaces. This approach will enhance off-design-point performance with minimal complexity, weight, and cost. Termed the Morphing Nacelle, this concept provides an attractive propulsion option for Vertical Take-off and Landing (VTOL) aircraft, such conceptual Personal Air Vehicle (PAV) configurations proposed by NASA. An experimental proof of concept investigation of the Morphing Nacelle is detailed in this paper. A powered model shrouded fan model was constructed with Circulation Control (CC) devices integrated in the inlet and exit of the nacelle. Both CC devices consisted of an annular jet slot directing a jet sheet tangent to a curved surface, generally described as a Coanda surface. The model shroud was tailored for axial flight, with a diffusing inlet, but was operated off-design condition as a static lifting fan. Thrust stand experiments were conducted to determine if the CC devices could effectively improve off-design performance of the shrouded fan. Additional tests were conducted to explore the effectiveness of the CC devices a means to reduce peak static pressure on the ground below a lifting fan. Experimental results showed that off-design static thrust performance of the model was improved when the CC devices were employed under certain conditions. The exhaust CC device alone, while effective in diffusing the fan exhaust and improving weight flow into shroud inlet, tended to diminish performance of the fan with increased CC jet momentum. The inlet CC device was effective at reattaching a normally stalled inlet flow condition, proving an effective means of enhancing performance. A more dramatic improvement in static thrust was obtained when the inlet and exit CC devices were operated in unison, but only over a limited range of CC jet momentum. Operating the nacelle inlet and exit CC devices together proved very effective in reducing peak ground plane static pressure, while maintaining static thrust. The Morphing Nacelle concept proved effective at enhancing off-design performance of the model; however, additional investigation is necessary to generalize the results

Impacts of the Primary School Free Breakfast Initiative on socio-economic inequalities in breakfast consumption among 9–11-year-old schoolchildren in Wales

Objectives - Universal interventions may widen or narrow inequalities if disproportionately effective among higher or lower socio-economic groups. The present paper examines impacts of the Primary School Free Breakfast Initiative in Wales on inequalities in children's dietary behaviours and cognitive functioning.<p></p> Design Cluster - randomised controlled trial. Responses were linked to free school meal (FSM) entitlement via the Secure Anonymised Information Linkage databank. Impacts on inequalities were evaluated using weighted school-level regression models with interaction terms for intervention × whole-school percentage FSM entitlement and intervention × aggregated individual FSM entitlement. Individual-level regression models included interaction terms for intervention × individual FSM entitlement.<p></p> Setting - Fifty-five intervention and fifty-six wait-list control primary schools.<p></p> Subjects - Approximately 4500 children completed measures of dietary behaviours and cognitive tests at baseline and 12-month follow-up.<p></p> Results School-level models indicated that children in intervention schools ate a greater number of healthy items for breakfast than children in control schools (b = 0·25; 95 % CI 0·07, 0·44), with larger increases observed in more deprived schools (interaction term b = 1·76; 95 % CI 0·36, 3·16). An interaction between intervention and household-level deprivation was not significant. Despite no main effects on breakfast skipping, a significant interaction was observed, indicating declines in breakfast skipping in more deprived schools (interaction term b = −0·07; 95 % CI −0·15, −0·00) and households (OR = 0·67; 95 % CI 0·46, 0·98). No significant influence on inequality was observed for the remaining outcomes.<p></p> Conclusions - Universal breakfast provision may reduce socio-economic inequalities in consumption of healthy breakfast items and breakfast skipping. There was no evidence of intervention-generated inequalities in any outcomes

Laboratory Simulations of Mars Evaporite Geochemistry

Evaporite-rich sedimentary deposits on Mars were formed under chemical conditions quite different from those on Earth. Their unique chemistries record the chemical and aqueous conditions under which they were formed and possibly subsequent conditions to which they were subjected. We have produced evaporite salt mineral suites in the laboratory under two simulated Martian atmospheres: (1) present-day and (2) a model of an ancient Matian atmosphere rich in volcanic gases. The composition of these synthetic Mars evaporites depends on the atmospheres under which they were desiccated as well as the chemistries of their precursor brines. In this report, we describe a Mars analog evaporite laboratory apparatus and the experimental methods we used to produce and analyze the evaporite mineral suites

The SBF Survey of Galaxy Distances. IV. SBF Magnitudes, Colors, and Distances

We report data for $I$ band Surface Brightness Fluctuation (SBF) magnitudes, V-I colors, and distance moduli for 300 galaxies. The Survey contains E, S0 and early-type spiral galaxies in the proportions of 49:42:9, and is essentially complete for E galaxies to Hubble velocities of 2000 km/s, with a substantial sampling of E galaxies out to 4000 km/s. The median error in distance modulus is 0.22 mag. We also present two new results from the Survey. (1) We compare the mean peculiar flow velocity (bulk flow) implied by our distances with predictions of typical cold dark matter transfer functions as a function of scale, and find very good agreement with cold, dark matter cosmologies if the transfer function scale parameter $\Gamma$, and the power spectrum normalization $\sigma_8$ are related by $\sigma_8 \Gamma^{-0.5} \approx 2\pm0.5$. Derived directly from velocities, this result is independent of the distribution of galaxies or models for biasing. The modest bulk flow contradicts reports of large-scale, large-amplitude flows in the $\sim200$ Mpc diameter volume surrounding our Survey volume. (2) We present a distance-independent measure of absolute galaxy luminosity, \Nbar, and show how it correlates with galaxy properties such as color and velocity dispersion, demonstrating its utility for measuring galaxy distances through large and unknown extinction.Comment: Accepted for publication in ApJ (10 January 2001); 23 page

Alterations in Redox Homeostasis During Recovery From Unexplained Underperformance Syndrome in an Elite International Rower.

This case study of an international rower examines a diagnosis of Unexplained Under Performance Syndrome (UUPS or Overtraining Syndrome) describing a full recovery and return to elite competition the same year. On diagnosis and 4 and 14 months post-diagnosis, detailed assessments including physiological, nutritional, and biomarkers were made. Clinical examination and laboratory results for haematology, biochemistry, thyroid function, immunology, vitamins and minerals were unremarkable and did not explain the presentation and diagnosis. Redox biomarkers including hydroperoxides, plasma antioxidant capacity, red blood cell glutathione, superoxide dismutase, co-enzyme Q10, vitamin E (α and γ-tocopherol), and carotenoids (lutein, α-carotene, β-carotene) provided evidence of altered redox homeostasis. The recovery strategy began with 12 days of training abstinence and nutritional interventions, followed by 6-weeks of modified training. Four months post-intervention performance had recovered strongly, resulting in the athlete becoming European champion that same year. Further improvements in physiological and performance indices were observed at 14 months post-intervention. Physiologically relevant increases in concentrations of carotenoids were achieved at each post-intervention time point, exceeding the reported critical difference values. We conclude that increasing athlete phytonutrient intake may enhance recovery and tolerance to training and environmental stressors, reducing the risk of unexplained under performance syndrome. Alterations in redox homeostasis should be considered as part of the medical management in unexplained under performance syndrome. This is the first reported case study of an elite athlete with alterations in redox homeostasis in conjunction with a diagnosis of unexplained under performance syndrome

Accountability, Strategy, and International Non-Governmental Organizations

Increased prominence and greater influence expose international non-governmental development and environmental organizations (INGOs) to increased demands for accountability from a wide variety of stakeholdersdonors, beneficiaries, staffs, and partners among others. This paper focuses on developing the concept of INGO accountability, first as an abstract concept and then as a strategic idea with very different implications for different INGO strategies. We examine those implications for INGOs that emphasize service delivery, capacity-building, and policy influence. We propose that INGOs committed to service delivery may owe more accountability to donors and service regulators; capacity-building INGOs may be particularly obligated to clients whose capacities are being enhanced; and policy influence INGOs may be especially accountable to political constituencies and to influence targets. INGOs that are expanding their activities to include new initiatives may need to reorganize their accountability systems to implement their strategies effectively. This publication is Hauser Center Working Paper No. 7. The Hauser Center Working Paper Series was launched during the summer of 2000. The Series enables the Hauser Center to share with a broad audience important works-in-progress written by Hauser Center scholars and researchers