720 research outputs found

    AN ECONOMIC MODEL FOR IRRIGATION WELL MANAGEMENT IN A DECLINING AQUIFER

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    A computerized model is developed that uses the aquifer characteristics and irrigation requirements to estimate hydraulic properties of a well pumping from an unconfined aquifer with a steadily declining water table. The model simulates electrically-powered well operation under the most economical conditions. High versatility of model inputs allows examination of many facets of well management. One example is the effect of electricity price on the ratio of energy cost of total cost of supplying water at different average total heads. At current electricity prices, energy accounted for 65 to 70 percent of total water costs. In a second example, as average annual efficiency decreased, average annual cost per acre-foot increased and average annual pumping volume decreased, leaving average annual total energy costs almost constant.Resource /Energy Economics and Policy,

    Hamburger Helper Recipes

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    Hamburger Helper Recipes is a collection of essays and public addresses that aim to recuperate castoff and misfit material surrounding industries and tools which produce science-fiction fantasies, specifically videogames and television shows. The following essays confront the normative violence of capitalism, whiteness, and hetero-patriarchy that socially and technologically haunt these imaginary worlds and build hegemonic idealogy into their audiences. This collection takes industrial materials and software from their intended commercial purposes of production and “success” into places of abjection and quiet breakdown. The author’s own proximity to masculine and often toxic work cultures\u27\u27 within industrial spaces of coding and manufacturing has informed a practice of humor and play based in a conflicted love for industrial material. As it looks critically inward and outward from its own positionality, Hamburger Helper Recipes oscillates in relation to the inside or outside of that which is “standard”. The notion of a queer operative within these spaces is proposed as an undercover catalyst for the reimagination of these tools into tender co-conspirators or facilitators charged to break down taboo barriers imposed by normative, capitalist culture and model new relationships between individuals and collectives

    The Radio Recovery of SN 1970G: The Continuing Radio Evolution of SN 1970G

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    Using the Very Large Array, we have detected radio emission from the site of SN 1970G in the Sc galaxy M101. These observations are 31 years after the supernova event, making SN 1970G the longest monitored radio supernova. With flux densities of 0.12 +/- 0.020 mJy at 6 cm and 0.16 +/- 0.015 mJy at 20 cm, the spectral index of -0.24 +/- 0.20 appears to have flattened somewhat when compared with the previously reported value of -0.56 +/- 0.11, taken in 1990. The radio emission at 20 cm has decayed since the 1990 observations with a power-law index of beta_20cm = -0.28 +/- 0.13. We discuss the radio properties of this source and compare them to those of other Type II radio supernovae.Comment: 11 pages, 1 table and 2 figures; To appear in Astrophysical Journal Letter

    Measurement of the Parallax of PSR B0950+08 Using the VLBA

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    A new technique has been developed to remove the ionosphere's distorting effects from low frequency VLBI data. By fitting dispersive and non-dispersive components to the phases of multi-frequency data, the ionosphere can be effectively removed from the data without the use of {\em a priori} calibration information. This technique, along with the new gating capability of the VLBA correlator, was used to perform accurate astrometry on pulsar B0950+08, resulting in a much improved measurement of this pulsar's proper motion (Όα=−1.6±0.4\mu_{\alpha} = -1.6 \pm 0.4 mas/yr, ΌΎ=29.5±0.5\mu_{\delta} = 29.5 \pm 0.5 mas/yr) and parallax (π=3.6±0.3\pi = 3.6 \pm 0.3 mas). This puts the pulsar at a distance of 280±25280 \pm 25 parsecs, about twice as far as previous estimates, but in good agreement with models of the electron density in the local bubble.Comment: 5 pages, Latex with AASTEX. Accepted for publication in Ap
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