3,514 research outputs found
An investigation of vegetation and other earth resource/feature parameters using LANDSAT and other remote sensing data. A: LANDSAT. B: Remote sensing of volcanic emissions
There are no author-identified significant results in this report
BNL Citric Acid Technology: Pilot Scale Demonstration
The objective of this project is to remove toxic metals such as lead and cadmium from incinerator ash using the Citric Acid Process developed at Brookhaven National Laboratory. In this process toxic metals in bottom ash from the incineration of municipal solid waste were first extracted with citric acid followed by biodegradation of the citric acid-metal extract by the bacterium Pseudomonas fluorescens for metals recovery. The ash contained the following metals: Al, As, Ba, Ca, Cd, Cr, Cu, Fe, Mg, Mn, Ni, Pb, Se, Sr, Ti, and Zn. Optimization of the Citric Acid Process parameters which included citric acid molarity, contact time, the impact of mixing aggressiveness during extraction and pretreatment showed lead and cadmium removal from incinerator ash of >90%. Seeding the treated ash with P. fluorescens resulted in the removal of residual citric acid and biostabilization of any leachable lead, thus allowing it to pass EPA?s Toxicity Characteristic Leaching Procedure. Biodegradation of the citric acid extract removed >99% of the lead from the extract as well as other metals such as Al, Ca, Cu, Fe, Mg, Mn, Ti, and Zn. Speciation of the bioprecipitated lead by Extended X-ray Absorption Fine Structure at the National Synchrotron Light Source showed that the lead is predominantly associated with the phosphate and carboxyl functional groups in a stable form. Citric acid was completely recovered (>99%) from the extract by sulfide precipitation technique and the extraction efficiency of recovered citric acid is similar to that of the fresh citric acid. Recycling of the citric acid should result in considerable savings in the overall treatment cost. We have shown the potential application of this technology to remove and recover the metal contaminants from incinerator ash as well as from other heavy metal bearing wastes (i.e., electric arc furnace dust from steel industry) or soils. Information developed from this project is being applied to demonstrate the remediation of lead paint contaminated soils on Long Island
Coral of Opportunity Survivorship and the Use of Coral Nurseries in Coral Reef Restoration
Coral reef damage is unfortunately becoming a common occurrence off southeast Florida, U.S.A. Reattachment of the dislodged scleractinian corals usually initiates damage site restoration. Because mortality of dislodged colonies is typically high and natural recovery in southeast Florida is typically slow, transplantation of additional scleractinian corals into a damaged area has been used to accelerate reef recovery. Donor colonies available for transplantation have been grown in situ, grown in laboratories, and taken from nondamaged reef areas. An alternative source of donor colonies for transplantation into damaged sites is “corals of opportunity,” which we define as scleractinian corals that have been detached from the reef through natural processes or unknown events. This paper describes a project, initiated in 2001 in Broward County, Florida, that was developed to collect these dislodged colonies and transplant them to a coral nursery. Coral nurseries are interim locations that function as storage sites for corals of opportunity where they can be cached, stabilized, and allowed to grow, until needed as donor colonies for future restoration activities. This project is a partnership between a local university, county government, and a volunteer dive group. Two hundred and fifty corals of opportunity were collected, transplanted to the coral nurseries, and monitored for survival. Transplanted colony survival was similar to that of naturally attached control colonies and significantly greater than that of corals of opportunity left unattached. Results provide resource managers with information on the utility of using corals of opportunity as a source of transplant donor colonies, and the value of using coral nurseries to create a reserve of corals of opportunity for use in future coral reef restoration activities
Investigation of the ferromagnetic transition in the correlated 4d perovskites SrRuRhO
The solid-solution SrRuRhO () is a
variable-electron-configuration system forming in the nearly-cubic-perovskite
basis, ranging from the ferromagnetic 4 to the enhanced paramagnetic
4. Polycrystalline single-phase samples were obtained over the whole
composition range by a high-pressure-heating technique, followed by
measurements of magnetic susceptibility, magnetization, specific heat,
thermopower, and electrical resistivity. The ferromagnetic order in long range
is gradually suppressed by the Rh substitution and vanishes at .
The electronic term of specific-heat shows unusual behavior near the critical
Rh concentration; the feature does not match even qualitatively with what was
reported for the related perovskites (Sr,Ca)RuO. Furthermore, another
anomaly in the specific heat was observed at .Comment: Accepted for publication in PR
Retrofitting Word Vectors to Semantic Lexicons
Vector space word representations are learned from distributional information
of words in large corpora. Although such statistics are semantically
informative, they disregard the valuable information that is contained in
semantic lexicons such as WordNet, FrameNet, and the Paraphrase Database. This
paper proposes a method for refining vector space representations using
relational information from semantic lexicons by encouraging linked words to
have similar vector representations, and it makes no assumptions about how the
input vectors were constructed. Evaluated on a battery of standard lexical
semantic evaluation tasks in several languages, we obtain substantial
improvements starting with a variety of word vector models. Our refinement
method outperforms prior techniques for incorporating semantic lexicons into
the word vector training algorithms.Comment: Proceedings of NAACL 201
Skeletal Structural Basis of Density Banding in the Reef Coral Montastrea Annularis
Density banding in coral skeletons can provide for reconstruction of the coral\u27s growth en- vironment over long periods. The physical differ- ences between low and high density portions of a skeletal band are not well understood. The skeletal architecture of M. annularis from Southeast Flor- ida, the Florida Keys, St. Croix, the Bahamas, and Mexico was compared in X-ray revealed high den- sity (HD), low density (LD), and stress HD bands. Density changes arose from differences in the size, but not spacing, of exothecal structural elements (horizontal dissepiments and vertical costae). En- dothecal architecture size (e.g., columella, dissepi- ments, septa) was relatively constant between den- sity band types. Results have implications for studies of coral growth, sclerochronology, and iso- topic/trace element composition
Analysis of Factors Influencing Southeast Florida Coral Reef Community Composition
The southeast Florida reef system lies offshore a heavily populated and urbanized coast. These high latitude reefs are not only affected by their geography but also by anthropogenic factors that accompany an urban area such as dredging activities, ship groundings, waste water outfalls, runoff and beach erosion. Sedimentation has been shown to influence stony coral community composition including dominance, abundance, cover, diversity, and colony size. Using annual monitoring data collected since 2000, the southeastern Florida reef community is being analyzed to examine if and how sedimentation and other factors such as depth, distance from shore and distance from port channels might influence community composition. All data was collected by SCUBA divers conducting 30m2 belt transect surveys at 24 sites offshore Broward County (southeast), Florida within a depth range of 6 to 18 meters. Stony coral data included colony size, abundance, diversity, percent cover, and mortality. Sponge and octocoral density were collected to gather a more complete picture of community composition. Three sediment bottles at each annually monitored site were collected every 60 days. Weight and grain size of the contents were analyzed and used to determine sedimentation rates at each site. Additionally, the reefs off the southeast Florida coast can be categorized into unique habitat types. These habitat types are also being considered when studying reef community composition and its relationship to sedimentation and other factors
Marine Biological Monitoring in Broward County, Florida: Year 3 Annual Report
A study has been undertaken to monitor Broward County, Florida (southeast Florida) coral communities, reef fish assemblages and sedimentation rates in relation to possible effects from a proposed extensive beach renourishment (restoration) project. Coral communities and reef fish assemblages will be monitored at a total of 23 stations distributed offshore Broward County. This monitoring effort will characterize and quantify populations of scleractinian (stony) corals, octocorallian (gorgonian) corals, sponges, and reef fishes. In addition, sediment traps located at each station will be sampled and analyzed.
This document reports the data collected during the third year of this project. Coral communities and fish assemblages were monitored at each of the 23 sites between September and October 2002. In addition, sedimentation analysis for the November 2001, January 200-, March 2002, May 2002, July 2002 and September 2002 collections are reported.
For September/October 2002 (=Year 3), mean (± 1 S.D.) stony coral density for the 23 sites was 2.84 + 1.30 colonies/m2. Mean stony coral coverage was 2.16 ± 3.53%. Mean octocoral density was 8.93 ± 10.17 colonies/m2 and mean sponge density was 13.47 ± 5.90 colonies/m2. Although no significant difference was found between the three reef tracts for stony coral cover, stony coral density, and octocoral density, First Reef sites had greater mean stony coral coverage but lower octocoral density than Second and Third Reef sites. First Reef coral cover was much lower than the Third Reef when the First Reet site, FTL4, was removed from the analysis. FTL4 had much greater stony coral cover than the mean cover for the remaining First Reef sites (17.40% compared to 1.65%). Sponge density was significantly greater on the Third Reef sites than the First or Second Reef sites, which did not significantly differ. Shannon-Weaver Diversity Indices performed on the overall transect data resulted in values of 1.49 ± 0.48 and 1.71 ± 0.46 for cover and number of species respectively. Overall evenness was 0.67 ± 0.20 for number of species and 0.76 ± 0.14 for cover.
Examining the 23 total sites, mean stony coral density has not significantly changed from the Year 1 (January/February 2001) Year 2 (September/October 2001) and Year 3 (September/October 2002) monitoring events. Mean stony coral cover at these 23 sites was found to be significantly greater in Year 2 than in Year 1 or 3, which did not significantly differ. At these 23 sites, mean octocoral density did not significantly differ between Years while mean sponge density was found to be significantly greater in Year 1 than in Year 2 or 3, which did not significantly differ.
Stony coral density, stony coral coverage, octocoral density and sponge density data collected from the 18 monitoring sites established in 1997 and visited yearly from 1997 to 2002 were analyzed. There has been no significant difference in stony coral density from 1998 to 2002. The density of stony corals in 1997 was found to be significantly less than what was found in 1998 and 2002. Mean stony coral cover increased from 1997 to 2001 but decreased slightly in 2002. Statistically, stony coral cover did not differ from 1998 to 2002, but 1997 was found to have significantly less cover than in 2000 and 2001. The mean density of octocorals did not differ statistically between 1998 and 2002. Mean sponge density was found to be greatest in 1998 and has decrease each year with a low in density found in 2002. Statistically 1998 and 1999 had the greatest sponge density compared to 2001 and 2002, which had the lowest sponge density.
The results of a multivariate statistical procedure indicate that the stony coral assemblages off Broward County have changed little from 1997 to 2002. This procedure has also shown that the stony coral assemblages on the Third and Second Reef sites have gieater similarity and that either have with most of the First Reef sites.
Trends in fish density were similar to those trends identified within the coral community transects. The greatest density of fishes occurs on the Third Reef followed by the Second and First. A difference in richness was seen amongst the three Reefs with the First Reef having the lowest number of species. The differences noted in abundance, density, and richness between the data collected in January/February 2001 and in September/October 2001 and September/October 2002 confirm previous reports of temporal differences in the fish assemblage offshore Broward County (Spieler 1998).
The First Reef had a statistically higher rate of sedimentation than both the Second and Third Reefs for the period from November 2001 to September 2002. The November 2001 samples had the greatest sedimentation rates. Sedimentation analysis indicates that the average grain size was significantly highest on First Reef sites, with Second and Third Reel sites lacking significant difference from one another. Average sediment rates for the three reefs since August 1997 indicate that the First Reef typically has the highest rate of sedimentation followed by the Second, then Third Reefs. Both sedimentation rate and average grain size from November 2001 to September 2002 appear to be consistent with data collected from previous years during these same sampling intervals. A comparison of sedimentation rate and wind speed revealed a similar pattern: when wind speed is low, sedimentation rates are low, and vise versa. This relationship is logical considering winddriven waves may cause sediment resuspension.
Data collected and analyses completed during this monitoring project will be used to help evaluate effects from the proposed beach renourishment project
Dopant Spin States and Magnetism of Sn\u3csub\u3e1−x\u3c/sub\u3eFe\u3csub\u3ex\u3c/sub\u3eO\u3csub\u3e2\u3c/sub\u3e Nanoparticles
This work reports detailed investigations of a series of ∼2.6 nm sized, Sn1−xFexO2 crystallites with x = 0–0.10 using Mossbauer spectroscopy, x-ray photoelectron spectroscopy (XPS), electron paramagnetic resonance spectroscopy (EPR), and magnetometry to determine the oxidation state of Fe dopants and their role in the observed magnetic properties. The magnetic moment per Fe ion μ was the largest ∼6.48 × 10−3 μB for the sample with the lowest (0.001%) Fe doping, and it showed a rapid downward trend with increasing Fe doping. Majority of the Fe ions are in 3+ oxidation state occupying octahedral sites. Another significant fraction of Fe dopant ions is in 4+ oxidation state and a still smaller fraction might be existing as Fe2+ ions, both occupying distorted sites, presumably in the surface regions of the nanocrystals, near oxygen vacancies. These studies also suggest that the observed magnetism is not due to exchange coupling between Fe3+ spins. A more probable role for the multi-valent Fe ions may be to act as charge reservoirs, leading to charge transfer ferromagnetism
Effect of substrate thermal resistance on space-domain microchannel
In recent years, Fluorescent Melting Curve Analysis (FMCA) has become an almost ubiquitous feature of commercial quantitative PCR (qPCR) thermal cyclers. Here a micro-fluidic device is presented capable of performing FMCA within a microchannel. The device consists of modular thermally conductive blocks which can sandwich a microfluidic substrate. Opposing ends of the blocks are held at differing temperatures and a linear thermal gradient is generated along the microfluidic channel. Fluorescent measurements taken from a sample as it passes along the micro-fluidic channel permits fluorescent melting curves to be generated. In this study we measure DNA melting temperature from two plasmid fragments. The effects of flow velocity and ramp-rate are investigated, and measured melting curves are compared to those acquired from a commercially available PCR thermocycler
- …