18,421 research outputs found

    Preparing Preservice Teachers for the Experimental Design and Data Analysis SOL\u27s

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    Many elementary teachers find teaching the science Standards of Learning (SOL) difficult [1, 2]. Some are even threatened by them. Of particular concern are the SOLs related to experimental design, handling data, and the scientific method. A possible reason for this discomfort is because many of these elementary teachers have had limited-to-no exposure to experimentation. As one of the activities included under a recent National Science Foundation Science Teachers Enhancement Project (STEP) grant awarded to Hampton University in conjunction with Virginia Union University and St. Paul\u27s College, we included a teacher science fair competition. A special workbook/text was developed for this project and used to guide teachers through the research process; from observation, and hypothesis formation and testing through the evaluation of data and drawing conclusions from the experiment. Twenty-two teachers from the Richmond metropolitan area and King and Queen County developed individual projects (laboratory research), and prepared written reports and display boards to present their results. Projects were adjudicated by staff at the Science Museum of Virginia in a formal competition for teachers. Several teachers admitted that this was the first time that they had actually performed a full experiment. All participants agreed, at. the end, that they had a much better understanding of the process, and would be better able to teach it to their students. This successful activity is being submitted to the review panel as a reproducible model which affords preservice teachers an opportunity to strengthen their research skills. It can also make teachers feel more confident, and equip them to do a better job of teaching this block of SOLs

    Bibliography and summary of methods related to the error analysis of hybrid computers technical note no. 4

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    Bibliography and summary of methods used in error analysis of hybrid computer

    Gas chromatograph sample-transfer valve

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    Slide-type gate valve incorporates sampling volume and transfer passageway for guiding a metered quantity of gas from pressurized test cell to gas chromatograph. Gate is moved by pneumatic bellows-type actuator

    Miniature high pressure regulator

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    Metal bellows, capable of suppling required spring rate and operational stability, replaced diaphragms, sliding seals, and springs in design of small gas regulator

    Charged particle radiation environment for the Spacelab and other missions in low earth orbit, revision A

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    The physical charged particle dose to be encountered in low earth orbit Spacelab missions is estimated for orbits of inclinations from e8.5 to 90 deg and altitudes from 200 to 800 km. The dose encountered is strongly altitude dependent, with a weaker dependence on inclination. Doses range from 0.007 rads/day at 28.5 deg and 200 km to 1.57 rads/day at 28.5 deg and 800 km behind a 5.0 g/sq cm shield. Geomagnetically trapped protons were the primary source of damage over most of the range of altitudes and inclinations, with galactic cosmic rays making a significant contribution at the lowest altitudes

    Two-stage coaxial gas compressor

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    Compressor raises pressure of gases from low ambient supply during space experiments by a system of low weight, size, and power input. Dc rotary-torque motor and ball-screw drive shaft activate first and second stage of compressor, utilizing inertia forces to operate check valves

    System for sterilizing objects

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    A system for producing a stream of humidified sterilizing gas for sterilizing objects such as the water systems of space vehicles and the like includes a source of sterilant gas which is fed to a mixing chamber which has inlet and outlet ports. The level of the water only partially fills the mixing chamber so as to provide an empty space adjacent the top of the chamber. A heater is provided for heating the water in the chamber so as to produce a humidified atmosphere. The sterilant gas is fed through an arcuate shaped tubular member connected to the inlet port of the mixing chamber for producing a vortex type of flow of sterilant gas into the chamber for humidification. A tubular member extends from the mixing chamber for supplying the humidified sterilant gas to the object for being sterilized. Scrubbers are provided for removing the sterilant gas after use

    Instructions to the Jury: Summary Without Comment

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    Any attempt at sensible explanation requires state-by-state discussion. For the time being, therefore, it is simply mentioned that the merits or demerits of the mere colorless summary are hardly a profitable subject of discussion if it be true, as this paper contends, that in truth the instruction process of an overwhelming majority of the states stops very considerably short thereof
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