2,343 research outputs found

    Design, Operation, and Calibration of the Canal A Submerged Rectangular Measuring Flume

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    The D.M.A.D. dam and reservoir are located on the Servier River northeast of Delta, utah, and serve as a stroage reservoir for the winter and spring flows of the Sevier River below Sevier Bridge Reservoir. The D.M.A.D. dam has been constructed with two outlet works, one for feeding Canal A , which serves the Delta and Melville Irrigation Companies, while the other canal serves the Abraham and Desert Irrigation Companies. A gaging station located along Canal A has been used for many years to obtain flow measurements. The gaging station measurements appeared to be very inconsistent, and consequently, in 1963 a study was made to evaluate the accuracy of the station. The results of the study (Figure 1) showed that for a constant depth of flow, the flow rate might vary more than a foot. The flows conveyed by this canal range from 15 to 500 cfs. Canal A is five miles in length and has a total drop in grade of five feet, the average slope therefore being one foot per mile. Regulation of the end of the canal will cause backwater effects over the entire length of the canal. The backwater effects will result in increased seepage losses. The installation of a Parshall flume was contemplated for measuring the flows conveyed by Canal A but it would be necessary to place the floor of the flume 2.75 feet above the canal grade to insure free flow over the entire flow range. The use of such a flume would significantly increase the seepage losses between the measuring station adn the dam for all flows below the design discharge of 500 cfs. Since the D.M.A.D. reservoir is used primarily for regulation, increasing the water levels in Canal A would reduce the regulating head and the usefulness of the lower storage levels in the reservoir for the Delta and Melville Irrigation Companies

    MSFC's Advanced Space Propulsion Formulation Task

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    In NASA s Fiscal Year 2012, a small project was undertaken to provide additional substance, depth, and activity knowledge to the technology areas identified in the In-Space Propulsion Systems Roadmap, Technology Area 02 (TA-02), as created under the auspices of the NASA Office of the Chief Technologist (OCT). This roadmap was divided into four basic groups: (1) Chemical Propulsion, (2) Non-chemical Propulsion, (3) Advanced (TRL<3) Propulsion Technologies, and (4) Supporting Technologies. The first two were grouped according to the governing physics. The third group captured technologies and physic concepts that are at a lower TRL level. The fourth group identified pertinent technical areas that are strongly coupled with these related areas which could allow significant improvements in performance. There were a total of 45 technologies identified in TA-02, and 25 of these were studied in this formulation task. The goal of this task was to provide OCT with a knowledge-base for decisionmaking on advanced space propulsion technologies and not waste money by unintentionally repeating past projects or funding the technologies with minor impacts. This formulation task developed the next level of detail for technologies described and provides context to OCT where investments should be made. The presentation will begin with the list of technologies from TA-02, how they were prioritized for this study, and details on what additional data was captured for the technologies studied. Following this, some samples of the documentation will be provided, followed by plans on how the data will be made accessible

    Large-scale structure in a new deep IRAS galaxy redshift survey

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    We present here the first results from two recently completed, fully sampled redshift surveys comprising 3703 IRAS Faint Source Survey (FSS) galaxies. An unbiased counts-in-cells analysis finds a clustering strength in broad agreement with other recent redshift surveys and at odds with the standard cold dark matter model. We combine our data with those from the QDOT and 1.2 Jy surveys, producing a single estimate of the IRAS galaxy clustering strength. We compare the data with the power spectrum derived from a mixed dark matter universe. Direct comparison of the clustering strength seen in the IRAS samples with that seen in the APM-Stromlo survey suggests b_O/b_I=1.20+/-0.05 assuming a linear, scale independent biasing. We also perform a cell by cell comparison of our FSS-z sample with galaxies from the first CfA slice, testing the viability of a linear-biasing scheme linking the two. We are able to rule out models in which the FSS-z galaxies identically trace the CfA galaxies on scales 5-20h^{-1}Mpc. On scales of 5 and 10h^{-1}Mpc no linear-biasing model can be found relating the two samples. We argue that this result is expected since the CfA sample includes more elliptical galaxies which have different clustering properties from spirals. On scales of 20h^{-1}Mpc no linear-biasing model with b_O/b_I &lt; 1.70 is acceptable. When comparing the FSS-z galaxies to the CfA spirals, however, the two populations trace the same structures within our uncertaintie

    HST Imaging Polarimetry of the Gravitational Lens FSC10214+4724

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    We present imaging polarimetry of the extremely luminous, redshift 2.3 IRAS source FSC10214+4724. The observations were obtained with HST's Faint Object Camera in the F437M filter, which is free of strong emission lines. The 0.7 arcsec long arc is unresolved to 0.04 arcsec FWHM in the transverse direction, and has an integrated polarization of 28 +/- 3 percent, in good agreement with ground-based observations. The polarization position angle varies along the arc by up to 35 deg. The overall position angle is 62 +/- 3 deg east of north. No counterimage is detected to B = 27.5 mag (3σ3\sigma), giving an observed arc to counterimage flux ratio greater than 250, considerably greater than the flux ratio of 100 measured previously in the I-band. This implies that the configuration of the object in the source plane at the B-band is different from that at I-band, and/or that the lensing galaxy is dusty.Comment: 17 pages, 3 figures. Accepted for publication in Astronomical Journal, February 199

    Searching for Water Ice at the Lunar North Pole Using High-Resolution Images and Radar

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    Permanently shadowed regions (PSRs) at the lunar poles are potential reservoirs of frozen volatiles, and are therefore high-priority exploration targets. PSRs trap water and other volatiles because their annual maximum temperatures (40-100K) are lower than the sublimation temperatures of these species (i.e. H2O approx.104K). Previous studies using various remote sensing techniques have not been able to definitively characterize the distribution or abundance of ice in lunar PSRs. The purpose of this study is to search for signs of ice in PSRs using two complimentary remote sensing techniques: radar and visible images

    Spectropolarimetry of NGC 3783 and Mrk 509: Evidence for powerful nuclear winds in Seyfert 1 Galaxies

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    International audienceABSTRACT We present results from high signal-to-noise optical spectropolarimetric observations of the Seyfert 1 galaxies NGC 3783 and Mrk 509 in the 3500–7000 Å range. We find complex structure in the polarized emission for both objects. In particular, Position Angle (PA) changes across the Balmer lines show a distinctive ‘M’-shaped profile that had not been observed in this detail before, but could represent a common trait in Seyfert 1 galaxies. In fact, while this shape is observed in all Balmer lines in NGC 3783, Mrk 509 transitions into a ‘M’-shaped PA profile for higher transitions lines. We have modelled the observed profiles using the STOKES radiative transfer code and assuming that the scattering region is co-spatial with the BLR and outflowing. The results give compelling new evidence for the presence of nuclear winds in these two Seyfert 1 galaxies

    The Water Transfer Process as a Management Option for Meeting Changing Water Demands, Volume II

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    1 v. : ill. ; 28 cm V. 2.: Water transfers in Arizona / Gary C. Woodard, Cara S. McCarthy -- Water transfers in California : 1981-1989 / Brian E. Gray -- Transfers of water use in Colorado / Lawrence J. MacDonnell, Charles W. Howe, Teresa A. Rice -- Transfers of water use in New Mexico / F. Lee Brown, Charles DuMars, Michelle Minnis, Sue Anderson Smasal, David Kennedy, Julie A. Urban -- Review of the water rights transfer process and activity in Utah / Chris C. Hogge, Paul G. Hansen, J. Paul Riley, Ray J. Davis -- Water rights transfers in Wyoming / Mark Squillacehttps://scholar.law.colorado.edu/books_reports_studies/1092/thumbnail.jp

    The Water Transfer Process as a Management Option for Meeting Changing Water Demands, Volume I

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    1 v. : ill. ; 28 cm V. 1.: Introduction -- Summaries of state reports -- Findings and comparative analysis -- Summary and conclusionshttps://scholar.law.colorado.edu/books_reports_studies/1091/thumbnail.jp
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