3,861 research outputs found

    Ceiling-Floor Partition Separation: What Is It and Why Is It Occurring?

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    This publication is intended to increase the understanding of cracking or separation of finish materials occasionally found in light-frame wood construction. In many cases, the problem is caused by shrinking or swelling of the wood framing members due to changes in moisture content. Although unsightly, these cracks and separations are basically cosmetic and pose no structural problems. It is important to be able to differentiate between movement caused by the instability of wood and that caused by foundation movement or structural failure, which can cause major problems

    First phase testing of solar thermal engine at United Stirling

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    The objective of the program is to demonstrate that the Stirling engine is a practical efficient and reliable energy converter when integrated with a parabolic dish concentrator, and that it has the potential of being cost competitive with fossil fueled electric generating systems of today. The engine, with its receiver (solar heat exchanger), alternator and control system, is described

    Nail-Gluing of Roof Trusses, Frames and Other Structural Components

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    Pressure Treated Wood

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    Discusses chemical treatments to increase wood's fire resistance and protect it from rot and termites

    Vegetation Effects on Fish Distribution in Impounded Salt Marshes

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    We compared the density and biomass of resident fish in vegetated and unvegetated flooded habitats of impounded salt marshes in the northern Indian River Lagoon (IRL) Estuary of east-central Florida. A 1-m2 throw trap was used to sample fish in randomly located, paired sample plots (n = 198 pairs) over 5 seasons in 7 impoundments. We collected a total of 15 fish taxa, and 88% of the fishes we identified from the samples belonged to three species: Cyprinodon variegatus (Sheepshead Minnow), Gambusia holbrooki (Eastern Mosquitofish), and Poecilia latipinna (Sailfin Molly). Vegetated habitat usually had higher density and biomass of fish. Mean fish density (and 95% confidence interval) for vegetated and unvegetated sites were 8.2 (6.7–9.9) and 2.0 (1.6–2.4) individuals m-2, respectively; mean biomass (and 95% confidence interval) for vegetated and unvegetated sites were 3.0 (2.5–3.7) and 1.1 (0.9–1.4) g m-2, respectively. We confirmed previous findings that impounded salt marshes of the northern IRL Estuary produce a high standing stock of resident fishes. Seasonal patterns of abundance were consistent with fish moving between vegetated and unvegetated habitat as water levels changed in the estuary. Differences in density, mean size, and species composition of resident fishes between vegetated and unvegetated habitats have important implications for movement of biomass and nutrients out of salt marsh by piscivores (e.g., wading birds and fishes) via a trophic relay

    Scale-Dependent Habitat Selection of Nesting Great Egrets and Snowy Egrets

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    Foraging habitat selection of nesting Great Egrets ( Ardea alba ) and Snowy Egrets ( Egretta thula ) was investigated within an estuary with extensive impounded salt marsh habitat. Using a geographic information system, available habitat was partitioned into concentric bands at five, ten, and 15 km radius from nesting colonies to assess the relative effects of habitat composition and distance on habitat selection. Snowy Egrets were more likely than Great Egrets to depart colonies and travel to foraging sites in groups, but both species usually arrived at sites that were occupied by other wading birds. Mean flight distances were 6.2 km (SE = 0.4, N = 28, range 1.8-10.7 km) for Great Egrets and 4.7 km (SE = 0.48, N = 31, range 0.7-12.5 km) for Snowy Egrets. At the broadest spatial scale both species used impounded (mostly salt marsh) and estuarine edge habitat more than expected based on availability while avoiding unimpounded (mostly fresh water wetland) habitat. At more local scales habitat use matched availability. Interpretation of habitat preference differed with the types of habitat that were included and the maximum distance that habitat was considered available. These results illustrate that caution is needed when interpreting the results of habitat preference studies when individuals are constrained in their choice of habitats, such as for central place foragers

    Estimating Sighting Proportions of American Alligator Nests during Helicopter Survey

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    Proportions of American alligator (Alligator mississippiensis) nests sighted during aerial survey in Florida were estimated based upon multiple surveys by different observers. We compared sighting proportions across habitats, nesting seasons, and observer experience levels. The mean sighting proportion across all habitats and years was 0.736 (SE=0.024). Survey counts corrected by the mean sighting proportion reliably predicted total nest counts (R2=0.933). Sighting proportions did not differ by habitat type (P=0.668) or year P=0.328). Experienced observers detected a greater proportion of nests (P<O.OOOl) than did either less experienced or inexperienced observers. Reliable estimates of nest abundance can be derived from aerial counts of alligator nests when corrected by the appropriate sighting proportion

    Censusing manatees: a report on the feasibility of using aerial surveys and mark and recapture techniques to conduct a population survey of the West Indian Manatee

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    This report results from an invitation to review the needs and prospects for capture-recapture and aerial census studies of the manatee (Trichechus manatus) in Florida. Three aerial reconnaissance flights provided a first hand view of manatee habitats, as follows: May 3, Suwannee River to Kings Bay and Crystal River (Rathbun, Eberhardt), May 4, Vero Beach to Ft. Lauderdale and Ft. Myers by way of Whitewater Bay (Rose, Percival, Eberhardt), and May 5, Cape Canaveral to Jacksonville, St. Johns River and Blue Spring (Rose, Kinnaird, Eberhardt). (24 page document

    Conceptual model of salt marsh management on Merritt Island National Wildlife Refuge, Florida: final report

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    Diking and holding water on salt marshes ("impounding" the marsh) is a management technique used on Merritt Island National Wildlife Refuge (MINWR) and elsewhere in the Southeast to: a) prevent the reproduction of saltmarsh mosquitos, and b) attract wintertering waterfowl and other marsh, shore, and wading birds. Because of concern that diking and holding water may interfere with the production of estuarine fish and shellfish, impoundment managers are being asked to consider altering management protocol to reduce or eliminate any such negative influence. How to change protocol and preserve effective mosquito control and wildlife management is a decision of great complexity because: a) the relationships between estuarine organisms and the fringing salt marshes at the land-water interface are complex, and b) impounded marshes are currently good habitat for a variety of species of fish and wildlife. Most data collection by scientists and managers in the area has not been focused on this particular problem. Furthermore, collection of needed data may not be possible before changes in protocol are demanded. Therefore, the purpose of this document is two-fold: 1) to suggest management alternatives, given existing information, and 2) to help identify research needs that have a high probability of leading to improved simultaneous management of mosquitos, waterfowl, other wildlife, freshwater fish, and estuarine fish and shellfish on the marshland of the Merritt Island National Wildlife Refuge. (92 page document

    Attitudes to telecare among older people, professional care workers and informal carers: a preventative strategy or crisis management?

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    This paper reports findings from an attitudinal survey towards telecare that emerged from twenty-two focus groups comprising ninety-two older people, fifty-five professional stakeholders and thirty-nine carers. These were convened in three different regions of England as a precursor to telecare service development. The results from this study suggest that informants’ views were shaped by prior knowledge of conventional health and social care delivery in their locality and the implication is that expectations and requirements in respect of telecare services in general are likely to be informed by wider perceptions about the extent to which community care should operate as a preventative strategy or as a mechanism for crisis management
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