2,262 research outputs found

    PC programs for the prediction of the linear stability behavior of liquid propellant propulsion systems and application to current MSFC rocket engine test programs, volume 1

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    Research on propulsion stability (chugging and acoustic modes), and propellant valve control was investigated. As part of the activation of the new liquid propulsion test facilities, it is necessary to analyze total propulsion system stability. To accomplish this, several codes were built to run on desktop 386 machines. These codes enable one to analyze the stability question associated with the propellant feed systems. In addition, further work was adapted to this computing environment and furnished along with other codes. This latter inclusion furnishes those interested in high frequency oscillatory combustion behavior (that does not couple to the feed system) a set of codes for study of proposed liquid rocket engines

    An Economic Analysis of the Marketing Operations of the Utah Berry Growers\u27 Association

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    Raspberry production in Utah is concentrated to a large extent in Utah county. According to the 1940 census, Utah county contains 62 percent of the state acreage of 611 acres. Average raspberry acreage in Utah is only about one-half acre per farm on farms reported as growing raspberries. With such small acreage the average producer cannot afford to devote very much time and effort to the production and marketing of raspberries. In the majority of cases raspberry production is carried on by the farmer\u27s wife, as a means of gaining “pin” money for use in the household. Proceeds from raspberries are one of the first cash incomes of the year received from fruit production. The harvesting of raspberries begins about the 25th of June and lasts until the end of July in Utah county. Because of the small acreage per grower, short production season, and high perishability of raspberries, a problem of marketing arises. Previous to 1939, the Salt Lake Public Market was over-supplied with raspberries during peaks of production. This resulted in low prices. Peddlers and truckers dictated the price received by producers. Thus, low prices often resulted and caused the berries to be left on the vines as the prices would not pay the cost of picking and packing. In order to provide better market outlets, establish satisfactory grades and standards, and provide for more orderly marketing, the producers in Utah county organized a Cooperative Marketing Association in 1939. This association was organized for the purpose of marketing raspberries grown by producers in Utah county from Mapleton to Pleasant Grove. The purpose of this study is: (1) to show the problems relating to the marketing of raspberries in Utah, (2) to analyze data made available by the Utah Berry Growers\u27 Association order to show market areas, methods of marketing, price received by method of sale, marketing expenses and to determine sales and prices received on week days and holidays, (3) to analyze the possibility of extending the markets for Utah raspberries

    A Participatory Action Research Study of the Collaborative Learning Process

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    The purpose of this participatory action research project was to identify attributes that contribute to a successful collaborative learning experience. Data analysis revealed the following emergent themes to be important: reflection and dialogue, interpersonal relationships, and group and individual responsibilities

    Improved spacecraft radio science using an on-board atomic clock: application to gravitational wave searches

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    Recent advances in space-qualified atomic clocks (low-mass, low power-consumption, frequency stability comparable to that of ground-based clocks) can enable interplanetary spacecraft radio science experiments at unprecedented Doppler sensitivities. The addition of an on-board digital receiver would allow the up- and down-link Doppler frequencies to be measured separately. Such separate, high-quality measurements allow optimal data combinations that suppress the currently-leading noise sources: phase scintillation noise from the Earth's atmosphere and Doppler noise caused by mechanical vibrations of the ground antenna. Here we provide a general expression for the optimal combination of ground and on-board Doppler data and compute the sensitivity such a system would have to low-frequency gravitational waves (GWs). Assuming a plasma scintillation noise calibration comparable to that already demonstrated with the multi-link CASSINI radio system, the space-clock/digital-receiver instrumentation enhancements would give GW strain sensitivity of 2.0×10172.0 \times 10^{-17} for randomly polarized, monochromatic GW signals over a two-decade (0.00010.01\sim0.0001-0.01 Hz) region of the low-frequency band. This is about an order of magnitude better than currently achieved with traditional two-way coherent Doppler experiments. The utility of optimally combining simultaneous up- and down-link observations is not limited to GW searches. The Doppler tracking technique discussed here could be performed at minimal incremental cost to also improve other radio science experiments (i.e. tests of relativistic gravity, planetary and satellite gravity field measurements, atmospheric and ring occultations) on future interplanetary missions.Comment: 21 pages, 5 figures. Submitted to Phys. Rev.

    The Ursinus Weekly, March 1, 1954

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    Helfferich tells causes of delay in Union work • U.C. Supply Store resumes full operation today • Ruby show to be presented • Band starts practice for Spring concert • Composition and technique discussed by Walter Hansen • Summer School to feature single session • U. of Penn band to present concert here • Dorthee von Miller to speak at AAUW program Wed. • Spring play cast revealed; Wright, Rack in lead roles • WSGA group holds meeting • John Canady to speak at seminar sessions • WAA will present variety show Mar. 11 • Dr. Allan Rice to present Scandinavian readings • Editorials: Support the Supply; Chinese controversy • Unusual campus rules • She felt like a young colt; But looked like an old .45 • Al Sare tells of Navy life • Reporter misses big scoop; Must turn in notebook • Just plain Bill reports Belles vs. Albright game • Little Belles top Bryn Mawr • Muhlenberg decisions Bears in heartbreaker • Shreiner, Hobson, South, Rimby\u27s, Maples win • Cagemen top Fords in two overtimes • Belles down C. Hill, 57-13 • Bears top Drexel, 24-8 prior to M.A.C. wrestling • Chestnut Hill topples U.C. mermaids, 37-19 • PMC squeezes netmen to win • Snell\u27s Belles win again; Hand Wagner 55-20 losshttps://digitalcommons.ursinus.edu/weekly/1490/thumbnail.jp

    The Ursinus Weekly, March 1, 1954

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    Helfferich tells causes of delay in Union work • U.C. Supply Store resumes full operation today • Ruby show to be presented • Band starts practice for Spring concert • Composition and technique discussed by Walter Hansen • Summer School to feature single session • U. of Penn band to present concert here • Dorthee von Miller to speak at AAUW program Wed. • Spring play cast revealed; Wright, Rack in lead roles • WSGA group holds meeting • John Canady to speak at seminar sessions • WAA will present variety show Mar. 11 • Dr. Allan Rice to present Scandinavian readings • Editorials: Support the Supply; Chinese controversy • Unusual campus rules • She felt like a young colt; But looked like an old .45 • Al Sare tells of Navy life • Reporter misses big scoop; Must turn in notebook • Just plain Bill reports Belles vs. Albright game • Little Belles top Bryn Mawr • Muhlenberg decisions Bears in heartbreaker • Shreiner, Hobson, South, Rimby\u27s, Maples win • Cagemen top Fords in two overtimes • Belles down C. Hill, 57-13 • Bears top Drexel, 24-8 prior to M.A.C. wrestling • Chestnut Hill topples U.C. mermaids, 37-19 • PMC squeezes netmen to win • Snell\u27s Belles win again; Hand Wagner 55-20 losshttps://digitalcommons.ursinus.edu/weekly/1490/thumbnail.jp

    Mass dependence of light nucleus production in ultrarelativistic heavy ion collisions

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    Light nuclei can be produced in the central reaction zone via coalescence in relativistic heavy ion collisions. E864 at BNL has measured the production of ten light nuclei with nuclear number of A=1 to A=7 at rapidity y1.9y\simeq1.9 and pT/A300MeV/cp_{T}/A\leq300MeV/c. Data were taken with a Au beam of momentum of 11.5 A GeV/cGeV/c on a Pb or Pt target with different experimental settings. The invariant yields show a striking exponential dependence on nuclear number with a penalty factor of about 50 per additional nucleon. Detailed analysis reveals that the production may depend on the spin factor of the nucleus and the nuclear binding energy as well.Comment: (6 pages, 3 figures), some changes on text, references and figures' lettering. To be published in PRL (13Dec1999

    Measurements of Light Nuclei Production in 11.5 A GeV/c Au+Pb Heavy-Ion Collisions

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    We report on measurements by the E864 experiment at the BNL-AGS of the yields of light nuclei in collisions of Au(197) with beam momentum of 11.5 A GeV/c on targets of Pb(208) and Pt(197). The yields are reported for nuclei with baryon number A=1 up to A=7, and typically cover a rapidity range from y(cm) to y(cm)+1 and a transverse momentum range of approximately 0.1 < p(T)/A < 0.5 GeV/c. We calculate coalescence scale factors B(A) from which we extract model dependent source dimensions and collective flow velocities. We also examine the dependences of the yields on baryon number, spin, and isospin of the produced nuclei.Comment: 21 figures-to be published in Phys. Rev.
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