4,622 research outputs found

    A review of US Army aircrew-aircraft integration research programs

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    If the U.S. Army's desire to develop a one crew version of the Light Helicopter Family (LHX) helicopter is to be realized, both flightpath management and mission management will have to be performed by one crew. Flightpath management, the helicopter pilot, and the handling qualities of the helicopter were discussed. In addition, mission management, the helicopter pilot, and pilot control/display interface were considered. Aircrew-aircraft integration plans and programs were reviewed

    Non-Metric Coordinates for Predicting Network Proximity

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    MANAGING MANURE TO IMPROVE AIR AND WATER QUALITY

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    Animal waste from confined animal feeding operations is a potential source of air and water quality degradation from evaporation of gases, runoff to surface water, and leaching to ground water. This report assesses the potential economic and environmental tradeoffs between water quality policies and air quality policies that require the animal agriculture sector to take potentially costly measures to abate pollution. A farm-level analysis of hog farms estimates the economic and environmental tradeoffs that occur when policies are designed to address pollutant flows to one environmental medium without considering flows to another medium. A national analysis addresses the broader impacts of coordinated (water and air) policies, including long-term structural adjustments and welfare impacts on both producers and consumers. The report also analyzes the potential implications of adding air quality regulations to existing Clean Water Act regulations in the Chesapeake Bay watershed, where a limited land base increases producers' costs of meeting manure management requirements.animal waste, nitrogen, ammonia, water quality, nutrient management plan, manure management costs, price and quantity adjustments, CAFO, Environmental Economics and Policy, Livestock Production/Industries,

    An upper bound for the minimum weight of the dual codes of desarguesian planes

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    AbstractWe show that a construction described in [K.L. Clark, J.D. Key, M.J. de Resmini, Dual codes of translation planes, European J. Combin. 23 (2002) 529–538] of small-weight words in the dual codes of finite translation planes can be extended so that it applies to projective and affine desarguesian planes of any order pm where p is a prime, and m≥1. This gives words of weight 2pm+1−pm−1p−1 in the dual of the p-ary code of the desarguesian plane of order pm, and provides an improved upper bound for the minimum weight of the dual code. The same will apply to a class of translation planes that this construction leads to; these belong to the class of André planes.We also found by computer search a word of weight 36 in the dual binary code of the desarguesian plane of order 32, thus extending a result of Korchmáros and Mazzocca [Gábor Korchmáros, Francesco Mazzocca, On (q+t)-arcs of type (0,2,t) in a desarguesian plane of order q, Math. Proc. Cambridge Philos. Soc. 108 (1990) 445–459]

    Aeolian sand transport over a wet, sandy beach

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    Abstract Quantifying aeolian transport within the intertidal zone is critical to understanding feedbacks between aeolian and nearshore processes in coastal environments. Here, we report a field study of aeolian transport over a wet bed in the intertidal zone. Predominate winds and beach orientation were aligned during all field observations. Mean grain size of bed samples were 0.18 mm and moisture content ranged from 16 to 17%. Velocity profiles were measured with a vertical array of cup anemometers. Sustained wind velocities were 9.5 m/s at 93 cm above the bed with gusts reaching 13.5 m/s. Five saltation traps captured particles in transport from the bed to a height of 15 cm. Particles in transport were wet and the highest moisture content of trapped sediments was found in the lowest saltation trap. Vertical flux profiles show a higher concentration of flux closer to the bed (81 to 89% below 5 cm) than those measured over dry beds. Power and exponential decay functions were fit to our vertical flux profiles; the exponential decay function best fit flux profiles with larger β coefficients and smaller α estimates than those fit to dry bed profiles. Total flux models predict transport below Belly's (1964) fluid threshold of motion for moist beds and model performance improves when using a threshold for dry sand. Our results suggest transport over wet beds is fundamentally different from transport over dry beds. However, more research is needed to discern the mechanics driving deviations in flux profiles over wet beds in field environments

    Consistency of cruise data of the CARINA database in the Atlantic sector of the Southern Ocean

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    Initially a North Atlantic project, the CARINA carbon synthesis was extended to include the Southern Ocean. Carbon and relevant hydrographic and geochemical ancillary data from cruises all across the Arctic Mediterranean Seas, Atlantic and Southern Ocean were released to the public and merged into a new database as part of the CARINA synthesis effort. Of a total of 188 cruises, 37 cruises are part of the Southern Ocean, including 11 from the Atlantic sector. The variables from all Southern Ocean cruises, including dissolved inorganic carbon (TCO2), total alkalinity, oxygen, nitrate, phosphate and silicate, were examined for cruise-to-cruise consistency in one collective effort. Seawater pH and chlorofluorocarbons (CFCs) are also part of the database, but the pH quality control (QC) is described in another Earth System Science Data publication, while the complexity of the Southern Ocean physics and biogeochemistry prevented a proper QC analysis of the CFCs. The area-specific procedures of quality control, including crossover analysis between stations and inversion analysis of all crossover data (i.e. secondary QC), are briefly described here for the Atlantic sector of the Southern Ocean. Data from an existing, quality controlled database (GLODAP) were used as a reference for our computations – however, the reference data were included into the analysis without applying the recommended GLODAP adjustments so the corrections could be independently verified. The outcome of this effort is an internally consistent, high-quality carbon data set for all cruises, including the reference cruises. The suggested corrections by the inversion analysis were allowed to vary within a fixed envelope, thus accounting for natural variability. The percentage of cruises adjusted ranged from 31% (for nitrate) to 54% (for phosphate) depending on the variable

    The architecture of innovation: Tracking face-to-face interactions with UbiComp technologies

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    The layouts of the buildings we live in shape our everyday lives. In office environments, building spaces affect employees' communication, which is crucial for productivity and innovation. However, accurate measurement of how spatial layouts affect interactions is a major challenge and traditional techniques may not give an objective view.We measure the impact of building spaces on social interactions using wearable sensing devices. We study a single organization that moved between two different buildings, affording a unique opportunity to examine how space alone can affect interactions. The analysis is based on two large scale deployments of wireless sensing technologies: short-range, lightweight RFID tags capable of detecting face-to-face interactions. We analyze the traces to study the impact of the building change on social behavior, which represents a first example of using ubiquitous sensing technology to study how the physical design of two workplaces combines with organizational structure to shape contact patterns.This is the author accepted manuscript. The final version is available at http://dl.acm.org/citation.cfm?id=2632056&CFID=528294814&CFTOKEN=36484024

    Cigarette smoking and urinary oestrogen excretion in premenopausal and post-menopausal women.

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    Cigarette smoking is associated with a reduction in the risk for endometrial cancer in post-menopausal women and it has been suggested that this is because smoking has an anti-oestrogenic effect. To investigate this, concentrations of oestrone, oestradiol and oestriol were measured in 24 h urine samples from 167 premenopausal women (53 smokers, 114 non-smokers) and 200 post-menopausal women (54 smokers, 146 non-smokers). Among premenopausal women there were no significant differences in oestrogen excretion between smokers and non-smokers. Among post-menopausal women, geometric mean excretion rates for oestrone and oestradiol did not differ significantly between groups, but oestriol excretion was 19% lower (95% confidence interval -34% to -1%) in smokers than in non-smokers. This may partly explain the reduced risk for endometrial cancer among post-menopausal smokers

    Cancer incidence in British vegetarians

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    Background: Few prospective studies have examined cancer incidence among vegetarians. Methods: We studied 61 566 British men and women, comprising 32 403 meat eaters, 8562 non-meat eaters who did eat fish ('fish eaters') and 20 601 vegetarians. After an average follow-up of 12.2 years, there were 3350 incident cancers of which 2204 were among meat eaters, 317 among fish eaters and 829 among vegetarians. Relative risks (RRs) were estimated by Cox regression, stratified by sex and recruitment protocol and adjusted for age, smoking, alcohol, body mass index, physical activity level and, for women only, parity and oral contraceptive use. Results: There was significant heterogeneity in cancer risk between groups for the following four cancer sites: stomach cancer, RRs (compared with meat eaters) of 0.29 (95% CI: 0.07–1.20) in fish eaters and 0.36 (0.16–0.78) in vegetarians, P for heterogeneity=0.007; ovarian cancer, RRs of 0.37 (0.18–0.77) in fish eaters and 0.69 (0.45–1.07) in vegetarians, P for heterogeneity=0.007; bladder cancer, RRs of 0.81 (0.36–1.81) in fish eaters and 0.47 (0.25–0.89) in vegetarians, P for heterogeneity=0.05; and cancers of the lymphatic and haematopoietic tissues, RRs of 0.85 (0.56–1.29) in fish eaters and 0.55 (0.39–0.78) in vegetarians, P for heterogeneity=0.002. The RRs for all malignant neoplasms were 0.82 (0.73–0.93) in fish eaters and 0.88 (0.81–0.96) in vegetarians (P for heterogeneity=0.001). Conclusion: The incidence of some cancers may be lower in fish eaters and vegetarians than in meat eaters

    Fast-ignition design transport studies: realistic electron source, integrated PIC-hydrodynamics, imposed magnetic fields

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    Transport modeling of idealized, cone-guided fast ignition targets indicates the severe challenge posed by fast-electron source divergence. The hybrid particle-in-cell [PIC] code Zuma is run in tandem with the radiation-hydrodynamics code Hydra to model fast-electron propagation, fuel heating, and thermonuclear burn. The fast electron source is based on a 3D explicit-PIC laser-plasma simulation with the PSC code. This shows a quasi two-temperature energy spectrum, and a divergent angle spectrum (average velocity-space polar angle of 52 degrees). Transport simulations with the PIC-based divergence do not ignite for > 1 MJ of fast-electron energy, for a modest 70 micron standoff distance from fast-electron injection to the dense fuel. However, artificially collimating the source gives an ignition energy of 132 kJ. To mitigate the divergence, we consider imposed axial magnetic fields. Uniform fields ~50 MG are sufficient to recover the artificially collimated ignition energy. Experiments at the Omega laser facility have generated fields of this magnitude by imploding a capsule in seed fields of 50-100 kG. Such imploded fields are however more compressed in the transport region than in the laser absorption region. When fast electrons encounter increasing field strength, magnetic mirroring can reflect a substantial fraction of them and reduce coupling to the fuel. A hollow magnetic pipe, which peaks at a finite radius, is presented as one field configuration which circumvents mirroring.Comment: 16 pages, 17 figures, submitted to Phys. Plasma
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