342 research outputs found

    PAN AIR: A computer program for predicting subsonic or supersonic linear potential flows about arbitrary configurations using a higher order panel method. Volume 2: User's manual (version 3.0)

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    A comprehensive description of user problem definition for the PAN AIR (Panel Aerodynamics) system is given. PAN AIR solves the 3-D linear integral equations of subsonic and supersonic flow. Influence coefficient methods are used which employ source and doublet panels as boundary surfaces. Both analysis and design boundary conditions can be used. This User's Manual describes the information needed to use the PAN AIR system. The structure and organization of PAN AIR are described, including the job control and module execution control languages for execution of the program system. The engineering input data are described, including the mathematical and physical modeling requirements. Version 3.0 strictly applies only to PAN AIR version 3.0. The major revisions include: (1) inputs and guidelines for the new FDP module (which calculates streamlines and offbody points); (2) nine new class 1 and class 2 boundary conditions to cover commonly used modeling practices, in particular the vorticity matching Kutta condition; (3) use of the CRAY solid state Storage Device (SSD); and (4) incorporation of errata and typo's together with additional explanation and guidelines

    Red-Cockaded Woodpecker Status and Management: West Gulf Coastal Plain and Interior Highlands

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    Red-cockaded woodpecker populations declined precipitously following European settlement and expansion and cutting of the original pine forests across the southeastern United States. By 1990 most residual populations lacked demographic viability, existed in degraded habitat, and were isolated from other populations. The primary causes of this situation were harvest of the original pine forests of the southeastern United States, conversion of forested lands to other uses, short-rotation silvicultural practices, and alteration of the fire regime in the regenerated forests. As social and legal mandates changed, management of red-cockaded woodpeckers became a higher priority. Intensive management for red-cockaded woodpeckers is currently practiced on most public and a few private lands that still support populations. Recent population trends and the current status of red-cockaded woodpeckers in Oklahoma, Arkansas, Texas, and Louisiana reflect historical factors and the efficacy of recent management

    Restoration Methods for Deepwater Swamps

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    Planting in deepwater swamp areas is difficult and time consuming, and nursery-grown seedlings are often not suited for such conditions. Baldcypress [Taxodium distichum (L.) Rich.], water tupelo (Nyssa aquatica L.), swamp blackgum [N. sylvatica var. biflora (Walt.) Sarg.], and green ash (Fraxinus pennsylvanica Marsh.) have been planted at various flooded sites in South Carolina and Louisiana. One of the most effective means of planting these species in flooded situations was to heavily prune the lateral roots, grasp the seedling at the root collar, and push it into the soil. Excellent results have been obtained with baldcypress, whereas green ash was most sensitive to root pruning and water depth. Water tupelo and swamp blackgum were intermediate in response. Tree shelters are commonly used to reduce herbivory problems, and height growth inside the shelters is increased. Additional research is needed to compare operational performance of various techniques under conditions of interacting stresses such as herbivory and flooding

    Geographic distribution:\u3ci\u3e Acrantophis dumerili\u3c/i\u3e (Duméril’s Madagascan Ground Boa). USA. Florida.

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    The geographic distribution of Acrantophis dumerili, a nonindigenous introduced species in Florida, with new records, is presented. Acrantophis dumerili is indigenous to southern and southwestern Madagascar. We provide the first vouchers for Miami-Dade and Bay counties, which were likely escaped or released pets. Florida already has three established species of booid snakes (one boa, two pythons), all introduced through the pet trade pathway. Although there is no clear evidence for an established population of A. dumerili in Florida at this time, the Bay County individuals in a rural area in the Florida panhandle are a particular concern given that two propagules were found at the same general site less than one month apart, and Florida has the largest number of introduced herpetofauna in the world with nonindigenous species having a one out of three chance of becoming established (Krysko et al. 2016, op. cit.)

    Geographic distribution:\u3ci\u3e Acrantophis dumerili\u3c/i\u3e (Duméril’s Madagascan Ground Boa). USA. Florida.

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    The geographic distribution of Acrantophis dumerili, a nonindigenous introduced species in Florida, with new records, is presented. Acrantophis dumerili is indigenous to southern and southwestern Madagascar. We provide the first vouchers for Miami-Dade and Bay counties, which were likely escaped or released pets. Florida already has three established species of booid snakes (one boa, two pythons), all introduced through the pet trade pathway. Although there is no clear evidence for an established population of A. dumerili in Florida at this time, the Bay County individuals in a rural area in the Florida panhandle are a particular concern given that two propagules were found at the same general site less than one month apart, and Florida has the largest number of introduced herpetofauna in the world with nonindigenous species having a one out of three chance of becoming established (Krysko et al. 2016, op. cit.)

    A meta-BACI approach forevaluating management intervention on chronic wasting disease in mule deer

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    Advances in acquiring and analyzing the spatial attributes of data have greatlyenhanced the potential utility of wildlife disease surveillance data for addressing problems ofecological or economic importance. We present an approach for using wildlife diseasesurveillance data to identify areas for (or of ) intervention, to spatially delineate pairedtreatment and control areas, and then to analyze these nonrandomly selected sites in a meta-analysis framework via before–after–control–impact (BACI) estimates of effect size. We applythese methods to evaluate the effectiveness of attempts to reduce chronic wasting disease(CWD) prevalence through intensive localized culling of mule deer (Odocoileus hemionus)innorth-central Colorado, USA. Areas where surveillance data revealed high prevalence or caseclusters were targeted by state wildlife management agency personnel for focal scale (onaverage ,17 km2) culling, primarily via agency sharpshooters. Each area of sustained cullingthat we could also identify as unique by cluster analysis was considered a potential treatmentarea. Treatment areas, along with spatially paired control areas that we constructed post hocin a case-control design (collectively called ‘‘management evaluation sites’’), were thendelineated using home range estimators. Using meta-BACI analysis of CWD prevalence datafor all management evaluation sites, the mean effect size (change of prevalence on treatmentareas minus change in prevalence on their paired control areas) was 0.03 (SE ¼ 0.03); meaneffect size on treatment areas was not greater than on paired control areas. Excluding cullsamples from prevalence estimates or allowing for an equal or greater two-year lag in systemresponses to management did not change this outcome. We concluded that managementbenefits were not evident, although whether this represented true ineffectiveness or was a resultof lack of data or insufficient duration of treatment could not be discerned. Based on ourobservations, we offer recommendations for designing a management experiment with 80%power to detect a 0.10 drop in prevalence over a 6–12-year period

    Restoration of Southern Ecosystems

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    Restoration of the myriad communities of bottomland hardwood and wetland forests and of the diverse communities of fire-dominated pine forests is the subject of intense interest in the Southern United States. Restoration practice is relatively advanced for bottomland hardwoods and longleaf pine (Pinus palustris Mill.), and less so for swamps and shortleaf pine (P. echinata Mill.). Most bottomland hardwood restoration is taking place on private land, while restoration of swamps and shortleaf pine occurs mostly on public land. Both public and private landowners are involved in the restoration of longleaf pine. Proper matching of species to site is critical to successful restoration of bottomland hardwoods. Techniques for longleaf pine restoration include the reintroduction of growing-season fire and the planting of longleaf pine seedlings and understory species. Safely reintroducing growing-season fire, however, may require initial manipulation of other vegetation by mechanical or chemical means to reduce built-up fuels

    Using deformations to explore 3D widget design

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    Restoration of a Severely Impacted Riparian Wetland System - The Pen Branch Project

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    The Savannah River Swamp is a 3020 ha forested wetland on the floodplain of the Savannah River and is located on the Department of Energy’s Savannah River Site (SRS) near Aiken, SC (Fig. 1). Historically the swamp consisted ofapproximately 50% baldcypress-water tupelo stands, 40% mixed bottomland hardwood stands, and 10% shrub, marsh, and open water. Tributeries of the river were typical of Southeastern bottomland hardwood forests. The hydrology was controlled by flow from four creeks that drain into the swamp and by flooding of the Savannah River. Upstream dams on the Savannah River have caused some alteration of the water levels and timing of flooding within the floodplain(Schneider et al., 1989)
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