1,015 research outputs found

    Benefit Transfer in the Field: Measuring the Benefits of Heterogeneous Wetlands using Contingent Valuation and Ecological Field Appraisals

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    Wetlands have functional values that may extend beyond traditional real estate values. This paper uses contingent valuation and ecological field assessments to place heterogeneous values on heterogeneous wetlands. Wetland functions evaluated are water quality, habitat, recreation, storing floodwaters and erosion abatement. The model used incorporates the public value of wetland functions and adds that value to the common local appraisal cost. We use a “percentage willingness-to-pay” value elicitation question in which respondents are asked about the percentage amount that the state government should pay over and above market value to purchase and preserve a wetland function. These values are then mapped into an ecological matrix to value the wetland as a whole. We show how these values can be applied in the field. Key Words: wetlands, appraisal, evaluation, mitigation, contingent valuation methodLength:

    Linking Recreation Demand and Willingness to Pay with the Inclusive Value: Valuation of Saginaw Bay Coastal Marsh

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    In this paper we propose an alternative model for linking revealed preference and stated preference models of recreation when a single travel cost measure is difficult to obtain. We show that this model can be used to test convergent validity and offers an alternative scope test that does not rely on split-sample contingent valuation scenarios. Our results are mixed. In three of four models the inclusive value is negatively related to the willingness to donate but unrelated to the willingness to pay. This result suggests that recreation nonusers hold nonuse values while recreation users do not hold nonuse values.

    Economic Values of Saginaw Bay Coastal Marshes

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    We estimate the economic values of Saginaw Bay coastal marshes with multiple methods. First we estimate the value of coastal marsh recreation with two variations of the travel cost method: the single-site recreation demand model and the recreation site selection or random utility model. Using the single site model the current level of day trip recreation in the Saginaw Bay coastal marsh area is valued at almost 16millioneachyear.Thepresentvalueis16 million each year. The present value is 239 million. Using the site selection travel cost model, an increase in 1125 acres of coastal marsh is valued at about 94,000annually.Thepresentvalueis94,000 annually. The present value is 1.83 million. Willingness to pay for recreation and other values of coastal marsh protection is estimated using the contingent valuation method. The annual value of protection of 1125 acres of coastal marsh is 113,000.Thepresentvalueis113,000. The present value is 2.2 million.

    Grit at work

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    Grit—the tendency to pursue especially long-term goals with both passion and perseverance—has been shown to predict high achievement in a range of individual performance domains. We make a case for introducing the concept of grit to the organizational behavior literature. To begin, we elaborate the conceptual foundations of grit, highlighting ways in which grit differs from related traits and situating grit in the broader literature on goal pursuit. We then discuss three organizational antecedents—leadership, culture, and job design—that can encourage grit at work. Next, we discuss how and under what circumstances encouraging grit can improve workplace outcomes such as employee retention, work engagement, and job performance. We conclude with suggestions for future research at the intersection of psychology and organizational behavior

    High Stability Engine Control (HISTEC)

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    Future aircraft turbine engines, both commercial and military, must be able to successfully accommodate expected increased levels of steady-state and dynamic engine-face distortion. The current approach of incorporating a sufficient component design stall margin to tolerate these increased levels of distortion would significantly reduce performance. The objective of the High Stability Engine Control (HISTEC) program is to design, develop, and flight demonstrate an advanced, high-stability, integrated engine control system that uses measurement-based, real-time estimates of distortion to enhance engine stability. The resulting distortion tolerant control reduces the required design stall margin, with a corresponding increase in performance and decrease in fuel burn. The HISTEC concept, consisting of a Distortion Estimation System and a Stability Management Control, has been designed and developed. The Distortion Estimation System uses a small number of high-response pressure sensors at the engine face to calculate indicators of the type and extent of distortion in real time. The Stability Management Control, through direct control of the fan and compressor pressure ratio, accommodates the distortion by transiently increasing the amount of stall margin available based on information from the Distortion Estimation System. Simulation studies have shown the HISTEC distortion tolerant control is able to successfully estimate and accommodate time-varying distortion. Currently, hardware and software systems necessary for flight demonstration of the HISTEC concept are being designed and developed. The HISTEC concept will be flight tested in early 1997

    Primate commensalism: the rhesus monkey in India

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    Deux recensements effectués en 1959-1960 et en 1990-1991 ont permis d'analyser la structure des populations de singes rhésus (Macaca mulatta) dans la partie centrale de l'Inde du Nord. La proportion de la population totale des rhésus vivant en situation commensale ou semi-commensale est passée de 88% à 86% entre les deux recensements. Le dernier recensement montre un passage significatif du semi-commensalisme au commensalisme, ainsi qu'un accroissement des populations non commensales vivant en forêt. Sur les 30 années, la taille des groupes s'est accrue dans 5 types d'habitat, déclinant dans les habitats urbains et villageois alors même que cette partie de la population est en croissanc

    Movement of Atrazine and Nitrate in Sharkey Clay Soil: Evidence of Preferential Flow (Bulletin #846)

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    Incidence of groundwater contamination by agrichemicals in the United States and elsewhere is of concern in terms of the health effects associated with chemical contaminants present in drinking water. The major objectives of this study were: (1) to quantify the mobility of atrazine and nitrates in a Sharkey clay soil in the presence of a shallow water table, and (2) to determine evidence of preferential flow patterns on the mobility of agricultural chemicals in such soils.https://digitalcommons.lsu.edu/agcenter_bulletins/1016/thumbnail.jp

    The High Stability Engine Control (HISTEC) Program: Flight Demonstration Phase

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    Future aircraft turbine engines, both commercial and military, must be able to accommodate expected increased levels of steady-state and dynamic engine-face distortion. The current approach of incorporating sufficient design stall margin to tolerate these increased levels of distortion would significantly reduce performance. The objective of the High Stability Engine Control (HISTEC) program is to design, develop, and flight-demonstrate an advanced, integrated engine control system that uses measurement-based estimates of distortion to enhance engine stability. The resulting distortion tolerant control reduces the required design stall margin, with a corresponding increase in performance and decrease in fuel burn. The HISTEC concept has been developed and was successfully flight demonstrated on the F-15 ACTIVE aircraft during the summer of 1997. The flight demonstration was planned and carried out in two phases, the first to show distortion estimation, and the second to show distortion accommodation. Post-flight analysis shows that the HISTEC technologies are able to successfully estimate and accommodate distortion, transiently setting the stall margin requirement on-line and in real-time. This allows the design stall margin requirement to be reduced, which in turn can be traded for significantly increased performance and/or decreased weight. Flight demonstration of the HISTEC technologies has significantly reduced the risk of transitioning the technology to tactical and commercial engines

    High Stability Engine Control (HISTEC): Flight Demonstration Results

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    Future aircraft turbine engines, both commercial and military, must be able to accommodate expected increased levels of steady-state and dynamic engine-face distortion. The current approach of incorporating sufficient design stall margin to tolerate these increased levels of distortion would significantly reduce performance. The High Stability Engine Control (HISTEC) program has developed technologies for an advanced, integrated engine control system that uses measurement- based estimates of distortion to enhance engine stability. The resulting distortion tolerant control reduces the required design stall margin, with a corresponding increase in performance and/or decrease in fuel burn. The HISTEC concept was successfully flight demonstrated on the F-15 ACTIVE aircraft during the summer of 1997. The flight demonstration was planned and carried out in two parts, the first to show distortion estimation, and the second to show distortion accommodation. Post-flight analysis shows that the HISTEC technologies are able to successfully estimate and accommodate distortion, transiently setting the stall margin requirement on-line and in real-time. Flight demonstration of the HISTEC technologies has significantly reduced the risk of transitioning the technology to tactical and commercial engines
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