2,043 research outputs found

    An Analysis of the Role of Tile-Drained Farmland Under Alternative Nitrogen Abatement Policies

    Get PDF
    Agricultural nitrogen is a major contributor to Gulf of Mexico hypoxia, and research has shown that agricultural subsurface tile drainage is a major carrier of nitrogen from croplands to streams and rivers. This study compares the results of abating nitrogen under a retired-land minimization policy with those of a new revenue-maximizing policy, paying particular attention to the role of tile-drained land. Findings reveal the retirement-minimizing policy resulted in more tile-drained land being retired and less being fertilizer-managed than was optimal under the net-return maximizing policy. Also, it led to a greater economic burden being shouldered by tile-drained land. Under both cases, tile drainage dominated the abatement process.abatement, ADAPT, drainage, hypoxia, nitrogen, Crop Production/Industries, Land Economics/Use,

    English verse drama from 1890 - 1935

    Get PDF
    Not availabl

    Targeting Agricultural Drainage to Reduce Nitrogen Losses in a Minnesota Watershed

    Get PDF
    Agricultural nitrogen losses are the major contributor to nitrogen loads in the Mississippi River, and consequently, to the existence of a hypoxic, or dead, zone in the Gulf of Mexico. Focusing on two small agricultural watersheds in southeast Minnesota, simulation results from the Agricultural Drainage And Pesticide Management (ADAPT) model were combined with a linear-optimization model to evaluate the environmental and economic impact of alternative land-use policies for reducing nitrogen losses. Of particular importance was the studys explicit focus on agricultural subsurface (tile) drainage, which has been identified as the major pathway for agricultural nitrogen losses in the upper Midwest, and the use of drainage-focused abatement policies. Results indicate that tile-drained land plays a key role in nitrogen abatement, and that a combined policy of nutrient management on tile-drained land and retirement of non-drained land is a cost-effective means of achieving a 20- or 30-percent nitrogen-abatement goal. Results also indicate that although it is cost-effective to abate on tile-drained land, it is not cost-effective to undertake policies that plug or remove tile drains from the landscape, regardless of whether the land would be retired or kept in production. Therefore, results imply that although tile-drained land is a major source of nitrogen lost to waterways, it is not cost-effective to remove the land from production or to remove the drainage from the land. Because of its value to agricultural production, it is better to keep tile-drained land in production under nutrient management and focus retirement policies on relatively less-productive, non-drained acres.Environmental Economics and Policy, Land Economics/Use,

    Performance of Distributed CFAR Test Under Various Clutter Amplitudes

    Get PDF
    We evaluate the performances of several distributed constant false-alarm rate (CFAR) tests operating in different background clutter conditions. The analysis considers the detection of Rayleigh target in various clutters with the possibility of differing clutter power levels in the test cells of distributed radars. Numerical results studied for a two-radar system show how the false-alarm rate of the maximum order statistic (MOS) test changes with differences in the clutter power levels of the test cells. The analysis for the detection of Rayleigh target in Rayleigh clutter indicates that, with the power levels of differing test cells, the OR fusion rule can be quite competitive with the new normalized test statistic (NTS). However, for the detection of Rayleigh target in Weibull or K-distributed clutter, the results show that NTS outperforms both the OR and the AND rules under the condition of large signal-to-clutter power ratio and moderate shape parameter values

    Robustness of Decentralized Tests with ε-Contamination Prior

    Get PDF
    We consider a decentralized detection problem where the prior density is not completely known, but is assumed to belong to an ε-contamination class. The expressions for the infimum and the supremum of the posterior probability that the parameter under question is in a given region, as the prior varies over the ε-contamination class, are derived. Numerical results are obtained for a specific case of an exponentially distributed observation and an exponentially distributed nominal prior. Asymptotic (as number of sensors tends to a large value) results are also obtained. The results illustrate the degree of robustness achieved with quantized observations as compared to unquantized observations

    Performance of Distributed CFAR Tests in Nonhomogeneous Background

    Get PDF
    We evaluate the performances of several distributed CFAR tests operating in nonhomogeneous background conditions. The analysis considers the detection of Rayleigh target in Rayleigh clutter sith the possibility of differing clutter power levels in the test cells of distributed radars. The tests considered include the previously defined maximum order statistic detector (MOS), belonging to a class of signal-plus- order statistic (S+OS) detectors, a new normalized test statistic (NTS), also belonging to the S+OS class, the OR and the AND fusion rules. Numerical results studied for a two radar system show how the false alarm rate of the MOS test changes with differences in the clutter power levels of the test cells. Results also indicate that, with differing test cells\u27 power levels, the OR fusion rule can be quite competitive to more complex tests, viz. NTS and MOS

    Naphthidines as redox indicators in titrations with vanadate

    Get PDF
    Naphthidine, naphthidinedisulphonic acid, 3,3'-dimethylnaphthidine and 3,3'-di-methylnaphthidinedisulphonic acid have been studied as redox indicators in titrations with vanadate. Sharp colour changes are obtained at the equivalence points in titrations of 0.05-0.01 N solutions of iron(II), hydroquinone, molybdenum(V) and uranium(IV) under appropriate conditions of acidity with oxalic or phosphoric acid as indicator catalyst. The transition potentials are reported. © 1978

    Spectrophotometric Determination of Ru(III) With Promethazine Hydrochloride

    Get PDF
    630-63

    Absorbable synthetic versus catgut suture material for episiotomy repair

    Get PDF
    Background: Episiotomy is a planned surgical incision made in perineum during childbirth. The type of suture material used for perineal repair following episiotomy will have effect on the intensiy of the pain experienced by mother. The objective of the present study is to determine the effects of rapide vicryl and catgut suture material on the amount of short term pain experienced by mother and to assess the amount of analgesia used following episiotomy suturing.Methods: Women with episiotomy cut was divided into two groups: group A consisted of episiotomy repair with catgut and group B with rapide vicryl. Following episiotomy pain will be assessed by visual analogue scale.Results: In KIMS hospital Bangalore - there was significant reduction in short term pain by vicryl rapide compared to chromic catgut and the need for analgesia.Conclusions: Vicryl rapide is effective in reducing the morbidity associated with episiotomy repair. There was significant reduction in short term pain and the need for analgesia, with decrease incidence of wound dehiscence.
    corecore