16,745 research outputs found

    Heat-treatment of metal parts facilitated by sand embedment

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    Embedding metal parts of complex shape in sand contained in a steel box prevents strains and warping during heat treatment. The sand not only provides a simple, inexpensive support for the parts but also ensures more uniform distribution of heat to the parts

    The collective gyration of a heavy ion cloud in a magnetized plasma

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    In both the ionospheric barium injection experiments CRIT 1 and CRIT 2, a long duration oscillation was seen with a frequency close to the gyro frequency of barium and a time duration of about one second. A model for the phenomena which was proposed for the CRIT 1 experiment is compared to the results from CRIT 2 which made a much more complete set of measurements. The model follows the motion of a low Beta ion cloud through a larger ambient plasma. The internal field of the model is close to antiparallel to the injection direction v sub i but slightly tilted towards the self polarization direction E sub p = -V sub i by B. As the ions move across the magnetic field, the space charge is continuously neutralized by magnetic field aligned electron currents from the ambient ionosphere, drawn by the divergence in the perpendicular electric field. These currents give a perturbation of the magnetic field related to the electric field perturbation by Delta E/Delta B approximately equal to V sub A. The model predictions agree quite well with the observed vector directions, field strengths, and decay times of the electric and magnetic fields in CRIT 2. The possibility to extend the model to the active region, where the ions are produces in this type of self-ionizing injection experiments, is discussed

    Development in helicopter tail boom strake applications in the US

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    The use of a strake or spoiler on a helicopter tail boom to beneficially change helicopter tail boom air loads was suggested in the United States in 1975. The anticipated benefits were a change of tail boom loads to reduce required tail rotor thrust and power and improve directional control. High tail boom air loads experienced by the YAH-64 and described in 1978 led to a wind tunnel investigation of the usefullness of strakes in altering such loads on the AH-64, UH-60, and UH-1 helicopters. The wind tunnel tests of 2-D cross sections of the tail boom of each demonstrated that a strake or strakes would be effective. Several limited test programs with the U.S. Army's OH-58A, AH-64, and UH-60A were conducted which showed the effects of strakes were modest for those helicopters. The most recent flight test program, with a Bell 204B, disclosed that for the 204B the tail boom strake or strakes would provide more than a modest improvement in directional control and reduction in tail rotor power

    Integrated electronic prescribing and robotic dispensing: a case study

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    INTRODUCTION: To quantify the benefits of electronic prescribing directly linked to a robotic dispensing machine. CASE DESCRIPTION: Quantitative case study analysis is used on a single case. Hospital A (1,000 beds) has used an integrated electronic prescribing system for 10 years, and in 2009 linked two robotic dispensing machines to the system. The impact on dispensing error rates (quality) and efficiency (costs) were assessed. EVALUATION AND DISCUSSION: The implementation delivered staff efficiencies above expectation. For the out-patient department, this was 16% more than the business case had suggested. For the in-patients dispensary, four staff were released for re-deployment. Additionally, £500,000 in stockholding efficiency above that suggested by the business case was identified. Overall dispensing error rates were not adversely affected and products dispensed by the electronic prescribing - robot system produced zero dispensing errors. The speed of dispensing increased also, as the electronic prescribing - robot combination permitted almost instantaneous dispensing from the point of a doctor entering a prescription. CONCLUSION: It was significant that the combination of electronic prescribing and a robot eliminated dispensing errors. Any errors that did occur were not as a result of the electronic prescribing - robotic system (i.e. the product was not stocked within the robot). The direct linking of electronic prescribing and robots as a dispensing system together produces efficiencies and improves the quality of the dispensing process

    Teacher Challenges to Implement Engineering Design in Secondary Technology Education (Third in a Three Part Series)

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    This descriptive study examined the current status of technology education teacher practices with respect to engineering design. This article is the third article in a three-part series presenting the results of this study. The first article in the series titled Examination of Engineering Design Curriculum Content highlighted the research findings regarding engineering design curriculum content delivered by technology education teachers. The second article in the series titled Examination of Assessment Practices for Engineering Design Projects in Secondary Technology Education reported technology education teachers’ assessment practices when implementing engineering design projects in the classroom. The sample for this study was drawn from the current International Technology Education Association (ITEA) membership database. This article will present the research findings that identified challenges faced by technology educators when seeking to implement engineering design

    The pregnant worker: how much is too much? Assessing safe activity levels.

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    Physicians should be able to advise pregnant women about safe amounts of physical activity in the workplace. A computerized literature search was used to review reproductive risks of physical activity, proper clinical evaluation and recommendations of the pregnant worker regarding physical activity, and current State of Hawaii disability legislation pertinent to pregnant workers. This article highlights the importance of making accurate clinical assessments regarding the continuation of work for the healthy pregnant worker and also provides physicians with an approach to assessing physical exposure risks of pregnant workers
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