72,187 research outputs found

    Death, Disease, and Dirty Power: Mortality and Health Damage Due to Air Pollution From Power Plants

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    Summarizes the findings of a study that looks at the contribution of air emissions from power plants to fine particle levels, and the impact of those emissions on human health. Discusses policies that would reduce power plant fine particle pollution

    Decoherence and fidelity in ion traps with fluctuating trap parameters

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    We consider two different kinds of fluctuations in an ion trap potential: external fluctuating electrical fields, which cause statistical movement (``wobbling'') of the ion relative to the center of the trap, and fluctuations of the spring constant, which are due to fluctuations of the ac-component of the potential applied in the Paul trap for ions. We write down master equations for both cases and, averaging out the noise, obtain expressions for the heating of the ion. We compare our results to previous results for far-off resonance optical traps and heating in ion traps. The effect of fluctuating external electrical fields for a quantum gate operation (controlled-NOT) is determined and the fidelity for that operation derived.Comment: 11 pages, 4 figure

    Photochemical Degradation of Malathion

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    Completion Report OWRT Agreement No. 14-34-0001-6002 Project No. A-057-ALASThis is the final completion report for a two-year project which began 1 November 1975. The original completion date was extended to 30 September 1977 to allow collection of samples and data through the summer of 1977. Malathion is a thiophosphate insecticide, 0,0-dimethly-S-(l,2dicarbethoxyethyl) phosphorodithioate: It is less toxic than DDT and decomposes over a much shorter period of time. With the suspension of DDT in pest control programs in 1965, use of malathion has been increasingly widespread in Alaska's interior. In spite of its low toxicity to animals, malathion is poisonous at some level. Lethal doses for domestic sheep and cattle are 150 mg/kg and 200 mg/kg. of body weight, respectively. The fatal dose of malathion for a 70 kg man has been estimated to be 60 g, with some clinical exceptions (McKee and Wolfe, 1963; Hayes, 1964). Dietary levels (ppm) producing minimal or no effect after continuous feeding for 90 days to 2 years to rats and dogs have been reported as 100-1000 and 100, respectively (Lehman, 1965). On the other hand, malathion has been identified by gas chromatography in extracts of water associated with several fish kills (Garrison, Keith, and Alford, 1972). In a study of malathion persistence in the soil near Fairbanks, Alaska, during the summer of 1967, half of the sampling sites showed the presence of malathion and its oxidation product, malaoxon, prior to aerial spraying (Holty, 1970). Since there had been no ground spraying since the summer of 1966, this would indicate that malathion was not degrading in the environment as fast as anticipated. This is important since it is then possible for the spring runoff to carry significant quantities of the pesticide and its degradation products into streams and rivers in the area. Retention of the malathion appears to depend on the amount of rainfall, and the summer of 1966 had been very dry. During the wetter summer of 1967, the post-spray soil samples showed a rapid drop in the level of malathion except at sampling sites in "mucky" soils which also increased noticeably in moisture as the amount of rainfall accumulated (Figure 1). Very little has been known about the aqueous photodecomposition of malathion and nothing was known of its vapor phase stability under atmospheric conditions and exposure to sunlight prior to this study.The work upon which this completion report is based was supported by funds provided by the U. S. Department of the Interior, Office of Water Research and Technology as authorized under the Water Resources Research Act of 1964, Public Law 88-379, as amended

    Entanglement in the Dicke model

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    We show how an ion trap, configured for the coherent manipulation of external and internal quantum states, can be used to simulate the irreversible dynamics of a collective angular momentum model known as the Dicke model. In the special case of two ions, we show that entanglement is created in the coherently driven steady state with linear driving. For the case of more than two ions we calculate the entanglement between two ions in the steady state of the Dicke model by tracing over all the other ions. The entanglement in the steady state is a maximum for the parameter values corresponding roughly to a bifurcation of a fixed point in the corresponding semiclassical dynamics. We conjecture that this is a general mechanism for entanglement creation in driven dissipative quantum systems.Comment: Minor changes: Reference added and references correcte

    Evidence for charged critical behavior in the pyrochlore superconductor RbOs2O6

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    We analyze magnetic penetration depth data of the recently discovered superconducting pyrochlore oxide RbOs2O6. Our results strongly suggest that in RbOs2O6 charged critical fuctuations dominate the temperature dependence of the magnetic penetration depth near Tc. This is in contrast to the mean-field behavior observed in conventional superconductors and the uncharged critical behavior found in nearly optimally doped cuprate superconductors. However, this finding agrees with the theoretical predictions for charged criticality and the charged criticality observed in underdoped YBa2Cu3O6.59.Comment: 5 pages, 4 figure

    Integrated use of LANDSAT data for state resource management

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    There are no author-identified significant results in this report

    A Deep Survey of HI-Selected Galaxies: The Sample and the Data

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    In a 21 cm neutral hydrogen survey of approximately 55 sq deg out to a redshift of cz=8340 km/s, we have identified 75 extragalactic HI sources. These objects comprise a well-defined sample of extragalactic sources chosen by means that are independent of optical surface brightness selection effects. In this paper we describe the Arecibo survey procedures and HI data, follow-up VLA HI observations made of several unusual sources, and Kitt Peak B-, R-, and I-band photometry for nearly all of the galaxies. We have also gathered information for some of the optically detected galaxies within the same search volume. We examine how samples generated by different types of search techniques overlap with selection by HI flux. Only the least massive HI object, which is among the lowest mass HI sources previously found, does not have a clear optical counterpart, but a nearby bright star may hide low surface brightness emission. However the newly-detected systems do have unusual optical properties. Most of the 40 galaxies that were not previously identified in magnitude-limited catalogs appear to be gas-dominated systems, and several of these systems have HI mass-to-light ratios among the largest values ever previously found. These gas-dominated objects also tend to have very blue colors, low surface brightnesses, and no central bulges, which correlate strongly with their relative star-to-gas content.Comment: 48 pages, 10 figures, Figure 3 included as 3 separate JPG images. To appear in Ap J Supplement
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