Advanced fiber placement of composite fuselage structures

The Hercules/NASA Advanced Composite Technology (ACT) program will demonstrate the low cost potential of the automated fiber placement process. The Hercules fiber placement machine was developed for cost effective production of composite aircraft structures. The process uses a low cost prepreg tow material form and achieves equivalent laminate properties to structures fabricated with prepreg tape layup. Fiber placement demonstrations planned for the Hercules/NASA program include fabrication of stiffened test panels which represent crown, keel, and window belt segments of a typical transport aircraft fuselage

Military Innovation in the Third Age of U.S. Unmanned Aviation, 1991–2015

Military innovation studies have largely relied on monocausal accounts—rationalism, institutionalism, or culture—to explain technologically innovative and adaptive outcomes in defense organizations. None of these perspectives alone provided a compelling explanation for the adoption outcomes of unmanned aerial vehicles (UAVs) in the U.S. military from 1991 to 2015. Two questions motivated this research: Why, despite abundant material resources, mature technology, and operational need, are the most-capable UAVs not in the inventory across the services? What accounts for variations and patterns in UAV innovation adoption? The study selected ten UAV program episodes from the Air Force and Navy, categorized as high-, medium-, and low-end cases, for within-case and cross-case analysis. Primary and secondary sources, plus interviews, enabled process tracing across episodes. The results showed a pattern of adoption or rejection based on a logic-of-utility effectiveness and consistent resource availability: a military problem to solve, and a capability gap in threats or tasks and consistent monetary capacity; furthermore, ideational factors strengthened or weakened adoption. In conclusion, the study undermines single-perspective arguments as sole determinants of innovation, reveals that military culture is not monolithic in determining outcomes, and demonstrates that civil-military relationships no longer operate where civilian leaders hold inordinate sway over military institutions.Lieutenant Colonel, United States Air ForceApproved for public release; distribution is unlimited

Challenges in comparing the quality of life of older people between ethnic groups, and the implications for national well-being indicators: a secondary analysis of two cross-sectional surveys

BackgroundThe current international interest in well-being indicators among governmental agencies means that many quality of life scales are potential components of such national indicator sets. Measuring well-being in minority groups is complex and challenging. Scales are available that have been validated in specific parts of the population, such as older people. However, validation among combinations of minority groups, such as older adults of ethnic minority backgrounds, is lacking. FindingsWe pooled data from two surveys of older adults in Great Britain: one conducted among White British people, and one among four ethnic minority groups. Quality of life was measured by the Older People's Quality of Life (OPQOL); Control, Autonomy, Self-realisation, Pleasure (CASP-19); and World Health Organization Quality of Life scale for older people (WHOQOL-OLD). We found differences, some significant, between groups in terms of self-reported importance of various aspects of quality of life. A regression model of each total quality of life scale revealed greater unexplained variability in the White British group than the others. Principal components analysis within each ethnic group's data showed considerable differences in the correlation structures. ConclusionsThere are differences between ethnic groups that are consistent across the three scales and are not explained by a battery of predictor variables. If scales such as these are used to compare quality of life between ethnic groups, or equivalently between geographical regions, the different results in each group are liable to bias any comparison which could lead to inequitable policy decisions.<br/

Filamentary Accretion Flows in the Embedded Serpens South Protocluster

One puzzle in understanding how stars form in clusters is the source of mass -- is all of the mass in place before the first stars are born, or is there an extended period when the cluster accretes material which can continuously fuel the star formation process? We use a multi-line spectral survey of the southern filament associated with the Serpens South embedded cluster-forming region in order to determine if mass is accreting from the filament onto the cluster, and whether the accretion rate is significant. Our analysis suggests that material is flowing along the filament's long axis at a rate of ~30Msol/Myr (inferred from the N2H+ velocity gradient along the filament), and radially contracting onto the filament at ~130Msol/Myr (inferred from HNC self-absorption). These accretion rates are sufficient to supply mass to the central cluster at a similar rate to the current star formation rate in the cluster. Filamentary accretion flows may therefore be very important in the ongoing evolution of this cluster.Comment: 19 pages, 8 figures, 2 tables; accepted for publication in Ap

Aerosol major ion record at Mount Washington

This study examined the seasonal cycles and regional-scale meteorological controls on the chemical properties of bulk aerosols collected from 1999 to 2004 at Mount Washington, the highest peak in the northeastern United States. The concentrations of NH4+ and SO42− peaked during summer months. The pattern for aerosol NO3− was more complicated with relatively high median concentrations characterizing spring and summer months, but with major elevated events occurring during fall, winter, and spring. The seasonal relationship between NH4+ and SO42− indicated that during warmer months a mixture of (NH4)2SO4 and NH4HSO4 was present, while it was mainly the latter in winter. More acidity and higher concentrations of the major species were generally associated with winds from the southwest and west sectors. The highest (≥95th percentile) concentrations of SO42− and NH4+ were associated with air mass transport from major upwind source regions in the Midwest and along the eastern seaboard. The ionic composition and seasonal cycle observed at Mount Washington were similar to those measured at other northeastern sites, but the range and average concentrations were much lower. These differences were exaggerated during wintertime. Included in this paper are several Eulerian case studies of SO2 conversion to SO42− during transit from Whiteface Mountain, New York, to Mount Washington. The calculations suggest a gas-phase SO2 oxidation rate of ∼1–2% per hour and demonstrate the possibility of using these two sites to investigate the chemical evolution of air masses as they move from Midwestern source regions to northern New England

Advanced tow placement of composite fuselage structure

The Hercules NASA ACT program was established to demonstrate and validate the low cost potential of the automated tow placement process for fabrication of aircraft primary structures. The program is currently being conducted as a cooperative program in collaboration with the Boeing ATCAS Program. The Hercules advanced tow placement process has been in development since 1982 and was developed specifically for composite aircraft structures. The second generation machine, now in operation at Hercules, is a production-ready machine that uses a low cost prepreg tow material form to produce structures with laminate properties equivalent to prepreg tape layup. Current program activities are focused on demonstration of the automated tow placement process for fabrication of subsonic transport aircraft fuselage crown quadrants. We are working with Boeing Commercial Aircraft and Douglas Aircraft during this phase of the program. The Douglas demonstration panels has co-cured skin/stringers, and the Boeing demonstration panel is an intricately bonded part with co-cured skin/stringers and co-bonded frames. Other aircraft structures that were evaluated for the automated tow placement process include engine nacelle components, fuselage pressure bulkheads, and fuselage tail cones. Because of the cylindrical shape of these structures, multiple parts can be fabricated on one two placement tool, thus reducing the cost per pound of the finished part

Exercise facilities for neurologically disabled populations : perceptions from the fitness industry

BACKGROUND: People with neurological disabilities (pwND) face many barriers to undertaking physical activity. One option for exercise alongside formal physiotherapy is local fitness facilities but accessibility is often found wanting and gyms are seen as unwelcoming to pwND. OBJECTIVE: The objective of this exploratory study was to investigate the perceptions of fitness facility managers with respect to exercise for pwND in a gym environment. The aim was to identify potential barriers to provision by the fitness industry for pwND. METHODS: The participants included those who were in a position to influence provision at a policy level and those working at management level within fitness providers. A mixed methods approach was used: a quantitative questionnaire and 4 qualitative interviews. Descriptive and correlational analysis, thematic content analysis and concurrent triangulation analysis was undertaken. RESULTS: Specially trained staff is perceived to be necessary to make fitness facilities accessible for pwND. CONCLUSIONS: Ensuring the provision of specially trained staff to support pwND to exercise in gyms may be the main barrier to provision for this population. Investigation into the standard training of fitness professionals combining the expertise of neurological physiotherapists with that of fitness professionals to meet the needs of pwND would be advantageous