9,120 research outputs found

    An overview of the quiet short-haul research aircraft program

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    An overview of the Quiet Short Haul Research Aircraft (QSRA) Program is presented, with special emphasis on its propulsion and acoustic aspects. A description of the NASA technical participation in the program including wind tunnel testing, engine ground tests, and advanced aircraft simulation is given. The aircraft and its systems are described and, measured performance, where available, is compared to program goals. Preliminary data indicate that additional research and development are needed in some areas of which acoustics is an example. Some of these additional research areas and potential experiments using the QSRA to develop the technology are discussed. The concept of the QSRA as a national flight research facility is explained

    Wind data from the 250-foot /76.2-meter/ tower at Wallops Island, Virginia

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    Statistical evaluation of sampled wind data from anemometers mounted on meteorological tower on Wallops Islan

    A contribution to the discussion on the safety of air weapons

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    Firearms legislation in the UK stems from the Firearms Act 1968 with its definition of a firearm as a lethal barrelled weapon of any description. The Act allows certain exceptions to be held without licence, most notably air weapons although these are limited by The Firearms (Dangerous Air Weapons) Rules 1969 and related regulations to below 12 ft lb (16.3 J) for air rifles and below 6 ft lb (8.1 J) for air pistols. Despite this there are occasional fatalities, typically 1 or 2 each year in the UK, from legally owned air weapons. In the USA there are over 20,000 visits each year to emergency departments due to injuries from air weapons and paintball guns. Despite this, limited research appears to have been carried out into the safety of air weapons and the present study tries to address this.Fresh samples of animal tissue were obtained from an abattoir or butcher and were embedded in ballistic gelatin. Pig heart, lung, liver and shoulder were used. By firing pellets into gelatin alone and into the combination of the gelatin and animal tissue it was possible to compare gelatin as a model for these tissues. The depth of penetration was similar but the residual track appeared to remain more open in the animal tissue. Pellets penetrated completely through the organ, with total penetration of gelatin and organ being typically around 10–15 cm.Samples of pig, cow and chicken skin were placed in contact with the gelatin or embedded in the gelatin to simulate the effect of skin on penetration into a body. Chicken skin had no effect, pig skin stopped the pellet and cow skin was perforated by the pellet. If cow skin was embedded in the gelatin there was little effect on the total amount of penetration, but cow skin on the front surface of the gelatin reduced penetration by about 30%.Computed tomography was used to examine the pellet track and to calculate the volume of damage produced. However, due to the similar densities of gelatin and organ a technique had to be developed to differentiate phases. A barium salt paste was applied to outer surfaces and iodine solution or barium nitrate solution containing red food colouring was injected into the pellet track to enhance the contrast of the track. The track through the gelatin tended to enclose itself whereas the track through the organ remained more open, presumably due to the inhomogeneity of the fibrous nature of the tissue.Pellets were also fired at construction materials (wood, plasterboard and brick) and computed tomography used to determine the volume of damage created. Pellets perforated single layers of wood and plasterboard and would embed in a second layer. However, if the two layers were in contact the pellet did not penetrate the first layer. An air rifle pellet could therefore perforate house construction materials, although the resultant kinetic energy would be low and further damage would be limited.Some of the possible physical parameters are discussed that might help predict the degree of damage caused, but from this study it is not possible to define a limit which could be proposed as safe

    The Djelk Ranger Program: an outsider’s perspective

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    This report is the result of a ten-day general conceptualisation research trip in May 2003 into an Indigenous community to study the Djelk Ranger program operating under the Bawinanga Aboriginal Corporation (BAC). During this visit I spent time with several different groups of Rangers and visited several sustainable wildlife harvesting sites which are described here. The Djelk Ranger program established by the BAC is built on the extensive knowledge and skills that already exist within this Indigenous community. The success of the ventures mentioned in this report is built on a unique blend of formal legal institutional mechanisms and customary law and socio-cultural conventions. Cooperative community-based wildlife resource management and aquaculture has the potential to deliver sustainable and cost effective development benefits for Indigenous landowners. Greater recognition of the valuable land management and biodiversity conservation roles undertaken by Indigenous people in these circumstances would seem appropriate, and it would be desirable for these roles to be reflected in more formal and sustained income arrangements than the current CDEP project funding. The opportunities for economic development in Indigenous communities, and some of the challenges that these communities face are demonstrated in the Djelk Ranger program initiative. The BAC is an impressive institution for its commitment to learning, communication, cultural integration, and economic development. There is clearly a need for such adaptive and flexible institutions to provide a bridge between cultures and protect the interests of remote Indigenous communities

    Development of Financial Management Competencies for Entry-Level and Advanced-Level Dietetic Practice: A Survey of Hospital Foodservice Directors/Chief Dietitians

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    Purpose: The purpose of this study was to identify competencies related to financial management for entry- and advanced-level dietitians practicing in the area of foodservice systems management. Specifically, this study: 1. Developed a comprehensive list of financial management competencies for entry- and advanced-level dietitians. 2. Determined the importance of financial management competencies for entry- and advanced-level dietetic practice as perceived by hospital foodservice directors/chief dietitians. 3. Identified underlying financial management factors for entry- and advanced-level dietitians. 4. Determined whether foodservice directors/chief dietitians who are Registered Dietitians (RDs) support specialty certification in foodservice management

    The Homeless School-Age Child: Can Educational Rights Meet Educational Needs?

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    Smithsonian Referrals (1973): Memorandum 01

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    All their eggs in one basket: a rocky reef nursery for the longnose skate (Raja rhina Jordan & Gilbert, 1880) in the southern California Bight

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    Skates (family Rajidae) are oviparous and lay tough, thick-walled eggs. At least some skate species lay their eggs in spatially restricted nursery grounds where embryos develop and hatch (Hitz, 1964; Hoff, 2007). After hatching, neonates may quickly leave the nursery grounds (Hoff, 2007). Egg densities in these small areas may be quite high. As an example, in the eastern Bering Sea, a site <2 km2 harbored eggs of Alaska skate (Bathyraja parmifera) exceeding 500,000/km2. All skate nursery grounds have been identified over soft sea floors (Lucifora and García, 2004; Hoff, 2007)
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