3,861 research outputs found
Ceiling-Floor Partition Separation: What Is It and Why Is It Occurring?
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
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
Pressure Treated Wood
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
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
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
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
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
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?
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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