8,310 research outputs found

    NY Pollution Discharge Elimination Permits for CAFOs, Management Adjustments and the Environment

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    Weakening demand for livestock and dairy produce, historically high prices for feed ingredients and increasingly strict regulations on animal waste management continue to put significant pressure on livestock and dairy operating margins. In this paper, we use representative farm mathematical programming models to analyze important linkages between farm management adjustments and changes in farm income due to recent changes in relevant agricultural prices and restrictions on land application of nutrients. We account explicitly for new restrictions on land application of nitrogen and phosphorus, and specifically applied to confined animal feeding operations (CAFOs). Our mathematical methods and the distinctive data available allows for the assessment of the effects on income and environmental nutrient loading for New York State dairy production farms. The results suggest that with current relative prices for feed ingredients, adjustments to dairy rations lead to increased nitrogen and phosphorus content in dairy waste and soil nutrient levels being applied well in excess of crop requirements. While the regulations will correct for this problem at the farm level, our results indicate that CAFOs could experience significant losses in income. These losses depend critically on the cost of off-site manure disposal. Our results also demonstrate that significant risks of excess nutrient loading remain during extreme weather events.CAFO regulations, nutrient management, manure disposal, mathematical programming, environmental quality, Environmental Economics and Policy, Farm Management, Production Economics,

    The Replication Argument for Incompatibilism

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    In this paper, I articulate an argument for incompatibilism about moral responsibility and determinism. My argument comes in the form of an extended story, modeled loosely on Peter van Inwagen’s “rollback argument” scenario. I thus call it “the replication argument.” As I aim to bring out, though the argument is inspired by so-called “manipulation” and “original design” arguments, the argument is not a version of either such argument—and plausibly has advantages over both. The result, I believe, is a more convincing incompatibilist argument than those we have considered previously

    Dairy Farm Management Adjustments to Biofuels-Induced Changes in Agricultural Markets

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    A mathematical programming model of a representative New York dairy farm is developed to identify optimal management adjustments to increased availability of corn distillers dried grains with solubles (DDGS). While at current prices DDGS feeding is limited to dry cows and young stock, as prices decrease, DDGS in lactating cow rations increase from 7.4% to 20% on a dry matter basis. While expected changes in net farm returns are modest, more important is the consideration of changes in nutrient management practices necessary to deal with increasing levels of nitrogen and phosphorus in the animal waste.Production, Management, Agribusiness, Agricultural Finance, Farm Management, Financial Economics, Resource /Energy Economics and Policy,

    Thermal expansion coefficients in Invar processed by selective laser melting

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    This work investigates whether the unique low thermal expansion property of Invar (64Fe–36Ni) is retained after processing using the additive manufacturing process selective laser melting (SLM). Using this process, near-full-density components (99.96%) were formed by melting thin (20 ÎŒm) layers of powdered Invar (15–45 ÎŒm particle size). The mechanical properties of SLM Invar were comparable to that of cold-drawn Invar36Âź; however, the thermal coefficient of expansion was observed to be a lower value and negative up until 100 °C. This negative value was attributed to residual stress in the as-deposited parts. The low thermal expansion property of Invar was still maintained when processed using a non-conventional layer-based additive manufacturing technique

    Nucleosynthesis in Outflows from the Inner Regions of Collapsars

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    We consider nucleosynthesis in outflows originating from the inner regions of viscous accretion disks formed after the collapse of a rotating massive star. We show that wind-like outflows driven by viscous and neutrino heating can efficiently synthesize Fe-group elements moving at near-relativistic velocities. The mass of 56Ni synthesized and the asymptotic velocities attained in our calculations are in accord with those inferred from observations of SN1998bw and SN2003dh. These steady wind-like outflows are generally proton rich, characterized by only modest entropies, and consequently synthesize essentially nothing heavier than the Fe-group elements. We also discuss bubble-like outflows resulting from rapid energy deposition in localized regions near or in the accretion disk. These intermittent ejecta emerge with low electron fraction and are a promising site for the synthesis of the A=130 r-process peak elements.Comment: 35 pages, 6 figures, added discussion of the influence of nuclear recombination on wind dynamics, to appear in Ap

    Antarctic Meteorite Classification and Petrographic Database Enhancements

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    The Antarctic Meteorite collection, which is comprised of over 18,700 meteorites, is one of the largest collections of meteorites in the world. These meteorites have been collected since the late 1970 s as part of a three-agency agreement between NASA, the National Science Foundation, and the Smithsonian Institution [1]. Samples collected each season are analyzed at NASA s Meteorite Lab and the Smithsonian Institution and results are published twice a year in the Antarctic Meteorite Newsletter, which has been in publication since 1978. Each newsletter lists the samples collected and processed and provides more in-depth details on selected samples of importance to the scientific community. Data about these meteorites is also published on the NASA Curation website [2] and made available through the Meteorite Classification Database allowing scientists to search by a variety of parameters. This paper describes enhancements that have been made to the database and to the data and photo acquisition process to provide the meteorite community with faster access to meteorite data concurrent with the publication of the Antarctic Meteorite Newsletter twice a year

    Censoring Distances Based on Labeled Cortical Distance Maps in Cortical Morphometry

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    Shape differences are manifested in cortical structures due to neuropsychiatric disorders. Such differences can be measured by labeled cortical distance mapping (LCDM) which characterizes the morphometry of the laminar cortical mantle of cortical structures. LCDM data consist of signed distances of gray matter (GM) voxels with respect to GM/white matter (WM) surface. Volumes and descriptive measures (such as means and variances) for each subject and the pooled distances provide the morphometric differences between diagnostic groups, but they do not reveal all the morphometric information contained in LCDM distances. To extract more information from LCDM data, censoring of the distances is introduced. For censoring of LCDM distances, the range of LCDM distances is partitioned at a fixed increment size; and at each censoring step, and distances not exceeding the censoring distance are kept. Censored LCDM distances inherit the advantages of the pooled distances. Furthermore, the analysis of censored distances provides information about the location of morphometric differences which cannot be obtained from the pooled distances. However, at each step, the censored distances aggregate, which might confound the results. The influence of data aggregation is investigated with an extensive Monte Carlo simulation analysis and it is demonstrated that this influence is negligible. As an illustrative example, GM of ventral medial prefrontal cortices (VMPFCs) of subjects with major depressive disorder (MDD), subjects at high risk (HR) of MDD, and healthy control (Ctrl) subjects are used. A significant reduction in laminar thickness of the VMPFC and perhaps shrinkage in MDD and HR subjects is observed when compared to Ctrl subjects. The methodology is also applicable to LCDM-based morphometric measures of other cortical structures affected by disease.Comment: 25 pages, 10 figure

    A Deep Search For Faint Galaxies Associated With Very Low-redshift C IV Absorbers: III. The Mass- and Environment-dependent Circumgalactic Medium

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    Using Hubble Space Telescope Cosmic Origins Spectrograph observations of 89 QSO sightlines through the Sloan Digital Sky Survey footprint, we study the relationships between C IV absorption systems and the properties of nearby galaxies as well as large-scale environment. To maintain sensitivity to very faint galaxies, we restrict our sample to 0.0015 < z < 0.015, which defines a complete galaxy survey to L > 0.01 L* or stellar mass log M_* > 8 Msun. We report two principal findings. First, for galaxies with impact parameter rho < 1 rvir, C IV detection strongly depends on the luminosity/stellar mass of the nearby galaxy. C IV is preferentially associated with galaxies with log M_* > 9.5 Msun; lower mass galaxies rarely exhibit significant C IV absorption (covering fraction f = 9 +12-6% for 11 galaxies with log M_* < 9.5 Msun). Second, C IV detection within the log M_* > 9.5 Msun population depends on environment. Using a fixed-aperture environmental density metric for galaxies with rho < 160 kpc at z < 0.055, we find that 57+/-12% (8/14) of galaxies in low-density regions (regions with fewer than seven L > 0.15 L* galaxies within 1.5 Mpc) have affiliated C IV absorption; however, none (0/7) of the galaxies in denser regions show C IV. Similarly, the C IV detection rate is lower for galaxies residing in groups with dark-matter halo masses of log Mhalo > 12.5 Msun. In contrast to C IV, H I is pervasive in the CGM without regard to mass or environment. These results indicate that C IV absorbers with log N(C IV) > 13.5 cm^-2 trace the halos of log M_* > 9.5 Msun galaxies but also reflect larger scale environmental conditions.Comment: 26 pages, 13 figures. ApJ, in pres
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