Current Search: Seawater (x)
Pages
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Title
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Leaching characteristics of lead and cadmium from waste-to-energy residues in sea water.
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Creator
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Shieh, C-S., Wei, Y-L., Duedall, I. W., Wang, Tsen C., Harbor Branch Oceanographic Institute
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Date Issued
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1992
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PURL
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http://purl.flvc.org/FCLA/DT/3352921
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Subject Headings
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Leaching, Lead, Cadmium, Seawater, Waste disposal in the ocean, Incineration
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Format
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Document (PDF)
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Title
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Effects of seawater exchange, pH and carbon supply on the growth of Gracilaria tikvahiae (Rhodophyceae) in large-scale cultures.
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Creator
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DeBusk, T. A., Ryther, John H., Harbor Branch Oceanographic Institute
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Date Issued
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1984
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PURL
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http://purl.flvc.org/fau/fd/FA00007019
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Subject Headings
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Gracilaria, Algae culture, Seawater, Hydrogen-ion concentration, Carbon
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Format
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Document (PDF)
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Title
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Effects of ammonium nitrate on sensitivity for determinations of copper, iron, and manganese in sea water by atomic absorption spectrometry with pyrolytically coated graphite tubes.
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Creator
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Montgomery, John R., Peterson, Gary N., Harbor Branch Oceanographic Institute
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Date Issued
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1980
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PURL
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http://purl.flvc.org/FCLA/DT/3331817
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Subject Headings
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Ammonium nitrate, Seawater--Analysis, Atomic absorption spectroscopy
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Format
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Document (PDF)
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Title
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The contribution of microorganisms to particulate carbon and nitrogen in surface waters of the Sargasso Sea near Bermuda.
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Creator
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Caron, D.A., Dam, H. G., Kremer, P., Lessard, E. J., Madin, L. P., Malone, Tom C., Napp, J. M., Peele, E. R., Roman, M. R., Youngbluth, Marsh J.
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Date Issued
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1995
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PURL
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http://purl.flvc.org/FCLA/DT/3331907
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Subject Headings
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Carbon, Nitrogen, Seawater--Composition, Sargasso Sea, Microorganisms
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Format
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Document (PDF)
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Title
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Chloride Diffusivity and Aging Factor Determined on Field Simulated Concrete Exposed to Seawater.
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Creator
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Raof, Farhad Fakheri, Presuel-Moreno, Francisco, Florida Atlantic University, College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
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Abstract/Description
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Chloride diffusivity in high performance concrete is influenced by the exposure environment, aside from the concrete mixture properties like, water to cementitious ratio (w/cm) and presence of add-on pozzolans. In this study, a set of concrete specimens (eleven-different concrete mixtures) were cast and exposed to three different environmental conditions (Tidal, Splash and Barge) in which the solution was seawater or brackish water. These exposures simulated environmental field conditions....
Show moreChloride diffusivity in high performance concrete is influenced by the exposure environment, aside from the concrete mixture properties like, water to cementitious ratio (w/cm) and presence of add-on pozzolans. In this study, a set of concrete specimens (eleven-different concrete mixtures) were cast and exposed to three different environmental conditions (Tidal, Splash and Barge) in which the solution was seawater or brackish water. These exposures simulated environmental field conditions. After the specimens had been wet cured for 32 days (on average), the specimens were exposed to three different field simulation conditions for up to 54 months. The specimens under the field simulated conditions were cored at 6, 10, 18, 30 and 54 months at four elevations and then the chloride profiles were obtained from the cores. The apparent diffusivity values for each profile were calculated based on Fick’s 2nd law. Then, the aging factor “m” was calculated by regression analysis of the diffusivity values vs. time (days) plotted in the log10-log10 scale. This was done for samples exposed to the three different exposure conditions and then the results were compared side-by-side. First, the “m” values were calculated using the exposure duration. Then, to study the effect of including the curing time on “m” value, the curing time was added to the exposure time and a new calculation and “m” value was obtained and compared with the previous results. Moreover, upon inspecting the chloride diffusivity values vs. time plots, it was observed that in some cases, a number of data points showed significantly higher or lower values in comparison with the rest of the data points. It was decided to recalculate the “m” values for these cases, and to only use selected data points instead of all data points (i.e., remove outlier data points). In terms of chloride diffusivity value, it was found that in most cases the specimens with higher water to cementitious (w/cm) ratio showed higher diffusivity, as expected. Further, the presence of pozzolans had a noticeable impact on the chloride diffusivity by decreasing the diffusion rate due to microstructure changes that occurred with time. In terms of “m” values, the result for the field simulated conditions showed a range of “m” values dependent on the specimen’s mixture composition and the elevation at which the specimens were cored. It was observed that the chloride diffusivity declined with time and after a certain amount of time (in this research, almost after 30 months) the diffusivity reduction became small and a transition in the slope of the diffusivity trend appeared in a number of cases. After the transition, the diffusivity trend reached either a plateau zone or continued with a significantly lower slope, depending on the time, composition and exposure. It was found that the specimens under tidal and splash field simulation conditions that had only fly ash in their mixtures showed higher “m” values when compared with samples that contained fly ash and silica fume or fifty percent slag.
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Date Issued
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2019
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PURL
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http://purl.flvc.org/fau/fd/FA00013254
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Subject Headings
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Concrete--Environmental testing, Seawater, Chlorides, Diffusion, Concrete--Deterioration
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Format
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Document (PDF)
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Title
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Using Low-Cost Multi-Depth Samplers to Characterize the Variability of Specific Conductance in Coastal South Florida Beaches.
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Creator
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Shaver, Kyle David, Root, Tara, Briggs, Tiffany Roberts, Florida Atlantic University, Department of Geosciences, Charles E. Schmidt College of Science
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Abstract/Description
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A small body of saline rich water rests in the saturated zone between the foredune and the shoreline at certain beaches. This region is beneath the water table and the top of the fresher groundwater, known as the Upper Saline Plume (USP). The USP is significant because density driven flow and chemical fluxes between freshwater, rainwater, and seawater contribute to biogeochemical processes in the subterranean estuary (Duque et al. 2020). The occurrence of the USP has been observed along...
Show moreA small body of saline rich water rests in the saturated zone between the foredune and the shoreline at certain beaches. This region is beneath the water table and the top of the fresher groundwater, known as the Upper Saline Plume (USP). The USP is significant because density driven flow and chemical fluxes between freshwater, rainwater, and seawater contribute to biogeochemical processes in the subterranean estuary (Duque et al. 2020). The occurrence of the USP has been observed along beaches that have a moderate to gentle slope, fine to medium grain size, and higher wave energy. The goal of this study was to determine if conditions for the presence of USP are consistent throughout different coastal beaches in southeast Florida while mapping the groundwater salinity across the beach. To identify the existence and delimit the boundary interface of the USP in the southeastern coast of Florida, multi–depth samplers were designed, built, and deployed along cross-shore transects at Jupiter and Gulfstream Beaches in Palm Beach County, FL. Groundwater samples were extracted along the transects to measure specific conductance. Although this study did not confirm the existence of the USP in South Florida beaches, an intermediate zone of water that is in-between the specific conductance ranges of relatively freshwater and relatively salty water was identified. Furthermore, the size of this intermediate zone was corresponded with beach slope, showing larger intermediate zones for steeper slopes and vice versa. Finally, temporal changes in the location and morphology of this intermediate zone were also identified in relation to a distinct disturbance event (Hurricane Isaias) which resulted in elevated ocean water levels.
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Date Issued
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2020
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PURL
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http://purl.flvc.org/fau/fd/FA00013625
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Subject Headings
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Beaches--Florida, Freshwater, Seawater, Water resources--Management
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Format
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Document (PDF)
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Title
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AN ASPECT OF THE LIMITING CURRENT DENSITY ALONG THE CIRCUMFERENCE OF A STEEL CYLINDER BY THE EFFECT OF THE FLOW VELOCITY (CATHODIC PROTECTION, CIRCULAR, BOUNDARY LAYER THICKNESS).
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Creator
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WANG, TIEN-JEN., Florida Atlantic University, Smith, Samuel W., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
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Abstract/Description
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The influence of hydrodynamic parameters and limiting current density by cathodic protection on a steel cylinder in flowing water is investigated. The limiting current density variations along the circumference of a circular cylinder are determined for different flow velocities. Several methods are also used to relate the cathodic current density distribution to variations in hydrodynamic and diffusional boundary layer thickness along the circumference of the cylinder for laminar and...
Show moreThe influence of hydrodynamic parameters and limiting current density by cathodic protection on a steel cylinder in flowing water is investigated. The limiting current density variations along the circumference of a circular cylinder are determined for different flow velocities. Several methods are also used to relate the cathodic current density distribution to variations in hydrodynamic and diffusional boundary layer thickness along the circumference of the cylinder for laminar and turbulent flow regimes. a comparison of experimental current densities on a cylinder to that predicated by theory is also examined.
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Date Issued
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1986
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PURL
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http://purl.flvc.org/fcla/dt/14316
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Subject Headings
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Steel--Cathodic protection, Sea-water corrosion
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Format
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Document (PDF)
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Title
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Adhesion of calcareous deposits formed on steel surfaces under cathodic polarization.
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Creator
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Luo, Jiunn-Shyong, Florida Atlantic University, Hartt, William H., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
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Abstract/Description
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A procedure has been devised to characterize the adhesion of calcareous deposits formed upon steel in association with cathodic polarization in seawater. This involved bending the substrate in-situ and characterization of deposit debonding in terms of visual appearance, changes in the cathodic current density and the net charge transferred in association with film disruption. Specific attention has been focused upon the influence of exposure time, applied potential, flow rate, temperature,...
Show moreA procedure has been devised to characterize the adhesion of calcareous deposits formed upon steel in association with cathodic polarization in seawater. This involved bending the substrate in-situ and characterization of deposit debonding in terms of visual appearance, changes in the cathodic current density and the net charge transferred in association with film disruption. Specific attention has been focused upon the influence of exposure time, applied potential, flow rate, temperature, substrate surface finish and electrolyte type upon deposit adhesion. Presence of a Mg-rich, inner film as well as the impingement of CaCO3 particles enhanced the adhesion of calcareous deposits. Electrostatic forces, Van der Waals attraction, and chemical alteration of precipitates could be important factors contributing to deposit adhesion.
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Date Issued
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1991
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PURL
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http://purl.flvc.org/fcla/dt/12271
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Subject Headings
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Sea-water corrosion, Marine steel, Cathodic protection, Adhesives
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Format
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Document (PDF)
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Title
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Calcareous deposits in simulated fatigue cracks of cathodically protected steel in seawater.
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Creator
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Davidson, Keith Dewayne., Florida Atlantic University, Haratt, William H.
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Abstract/Description
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An experiment was designed to provide a simulated steel fatigue crack under cathodic protection in seawater for study. Calcareous deposits were found to form in the simulated crack at -0.800, -0.900, -1.000 and -1.100 volts (SCE) with cycle frequencies of both 0.5 and 1.0 Hertz. By X-ray and SEM analysis, calcium carbonate deposits were shown to grow in quantities sufficient to block and become compressed by this simulated crack. Increased fluid velocities from crack pumping were shown to...
Show moreAn experiment was designed to provide a simulated steel fatigue crack under cathodic protection in seawater for study. Calcareous deposits were found to form in the simulated crack at -0.800, -0.900, -1.000 and -1.100 volts (SCE) with cycle frequencies of both 0.5 and 1.0 Hertz. By X-ray and SEM analysis, calcium carbonate deposits were shown to grow in quantities sufficient to block and become compressed by this simulated crack. Increased fluid velocities from crack pumping were shown to negatively affect crystal nucleation and growth. Due to kinetic barriers to crystal growth, aragonite and brucite were determined to be the most likely deposit type; excluding calcite, dolomite and magnesite. The deposits formed at -1.000V were shown by current requirements and SEM to provide the best protection as a coating.
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Date Issued
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1988
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PURL
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http://purl.flvc.org/fcla/dt/14442
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Subject Headings
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Steel--Fatigue, Cathodic protection, Sea-water corrosion
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Format
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Document (PDF)
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Title
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Analytical evaluation of marine concrete pile repairs.
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Creator
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Saleh, Zaher A. Abou., Florida Atlantic University, Reddy, Dronnadula V., College of Engineering and Computer Science, Department of Civil, Environmental and Geomatics Engineering
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Abstract/Description
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The purpose of the thesis is to determine and compare the performance characteristics of marine piles corroded by chloride diffusion and repaired by several different methods for both uncracked and cracked concrete and to determine their structural integrity. The long-term objective is the comparison of the analytical values with those from an on-going experimental evaluation. The time for chloride concentration reach the threshold value that initiates corrosion in the reinforcement has been...
Show moreThe purpose of the thesis is to determine and compare the performance characteristics of marine piles corroded by chloride diffusion and repaired by several different methods for both uncracked and cracked concrete and to determine their structural integrity. The long-term objective is the comparison of the analytical values with those from an on-going experimental evaluation. The time for chloride concentration reach the threshold value that initiates corrosion in the reinforcement has been determined by Fick's law, extended to 2-D and 3-D chloride diffusion, for (a) uncracked concrete, and (b) for cracked concrete with the Simplified Smeared Approach (SSA). The structural integrity of the concrete circular pile is compared before and alter repair, by (a) finite element modeling using ANSYS software with the maximum deflection, and (b) beam strength analysis to find the moment capacity for cracked and ultimate conditions. The overall findings indicate the adequacy of the repair procedures.
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Date Issued
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2003
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PURL
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http://purl.flvc.org/fcla/dt/13062
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Subject Headings
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Concrete piling, Reinforced concrete--Corrosion, Seawater corrosion
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Format
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Document (PDF)
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Title
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CORROSION FATIGUE CRACK INITIATION BEHAVIOR OF SEVERAL HIGH STRENGTH STEELS IN SEAWATER (POTENTIAL, CATHODIC, POLARIZATION).
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Creator
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SLOAN, FORREST EUGENE., Florida Atlantic University, Hartt, William H., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
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Abstract/Description
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'J 'ht' c· f feet of seawater ,_tnd potential on the fatigue crack initiation hehavior of several microalloyed and thermomPrhanically processed steels has been investigated. Five steels with yield strength in t~e range 500 to 750 MPa (73 to 108 ksi) were selected which included a range of processing histories from conventional quenching and tempering to precipitation hardening and direct quenching. These steels were chosen because of their potential utility as materials of construction for...
Show more'J 'ht' c· f feet of seawater ,_tnd potential on the fatigue crack initiation hehavior of several microalloyed and thermomPrhanically processed steels has been investigated. Five steels with yield strength in t~e range 500 to 750 MPa (73 to 108 ksi) were selected which included a range of processing histories from conventional quenching and tempering to precipitation hardening and direct quenching. These steels were chosen because of their potential utility as materials of construction for deep water compliant platform hull and riser systems. Blunt notch compact tension specimens were exposed to natural flowing seawater under constant load ampli tnrlc. conditions at both freely corroding and cathodically protected potentials. Cycles to crack initiation were characterized by cyclic stress intensity range normalized relative to the square root of notch radius. Test data are presented and compared with data from other tests and steels using appropriate stress analysis methods.
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Date Issued
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1986
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PURL
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http://purl.flvc.org/fcla/dt/14285
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Subject Headings
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Steel, High strength--Fatigue--Testing, Sea-water corrosion
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Format
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Document (PDF)
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Title
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Environmental cracking susceptibility of austenitic stainless steel alloys in acidified seawater.
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Creator
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Poulassichidis, Antonios N., Florida Atlantic University, Lipka, Stephen M., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
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Abstract/Description
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The stress corrosion cracking susceptibility of austenitic stainless steels SS304L, SS316L and SS904L was studied in an acidified seawater environment by slow strain rate testing at 24, 38 and 66$\sp\circ$C. Fractographic evidence of SCC susceptibility was obtained using scanning electron microscopy. The degree of susceptibility to SCC for each alloy in these environments is discussed based on the mechanical parameters, fractography and anodic polarization behavior. The results showed that...
Show moreThe stress corrosion cracking susceptibility of austenitic stainless steels SS304L, SS316L and SS904L was studied in an acidified seawater environment by slow strain rate testing at 24, 38 and 66$\sp\circ$C. Fractographic evidence of SCC susceptibility was obtained using scanning electron microscopy. The degree of susceptibility to SCC for each alloy in these environments is discussed based on the mechanical parameters, fractography and anodic polarization behavior. The results showed that SS904L performed better than SS304L and SS316L in the aforementioned environments.
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Date Issued
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1994
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PURL
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http://purl.flvc.org/fcla/dt/15071
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Subject Headings
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Stress corrosion, Seawater corrosion, Alloys--Stress corrosion
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Format
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Document (PDF)
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Title
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STUDY OF ELECTROCHEMISTRY MODIFICATIONS WITHIN CATHODICALLY PROTECTED FATIGUE CREVICES IN 3% SODIUM-CHLORIDE - DISTILLED WATER SOLUTION AND SEAWATER.
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Creator
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RAJPATHAK, SHIRISH SHRIDHAR., Florida Atlantic University, Hartt, William H., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
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Abstract/Description
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It is well recognized that the electrochemistry modifications within cathodically protected fatigue crevices in seawater has pronounced effect on crack growth rate. This study focuses its attention on potential distribution within simulated fatigue crevice as a function of electrolyte velocity, fatigue frequency and cathodic protection potential. Results of salt water electrolyte and seawater electrolyte are compared to bring about the effect of calcareous deposits, Finally, a mathematical...
Show moreIt is well recognized that the electrochemistry modifications within cathodically protected fatigue crevices in seawater has pronounced effect on crack growth rate. This study focuses its attention on potential distribution within simulated fatigue crevice as a function of electrolyte velocity, fatigue frequency and cathodic protection potential. Results of salt water electrolyte and seawater electrolyte are compared to bring about the effect of calcareous deposits, Finally, a mathematical model based on mass transfer laws is developed to rationalise potential distribution trends within fatigue crevice and are compared with the observed behaviour.
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Date Issued
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1983
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PURL
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http://purl.flvc.org/fcla/dt/14151
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Subject Headings
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Cathodic protection, Metals--Corrosion fatigue, Sea-water corrosion
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Format
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Document (PDF)
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Title
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High-Speed High-Frequency Acoustic Communications in Ports and Shallow Water.
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Creator
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Blue, Patrick Michael, Beaujean, Pierre-Philippe, Florida Atlantic University
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Abstract/Description
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A detailed study of a novel method for high-speed acoustic communications in ports and shallow water is presented. A series of field experiments, coupled with simulated results using an acoustic channel model have been conducted to outline the optimal modulation schemes for use in the highly reverberant and Doppler dominated shallow water acoustic channel. Field experiments were conducted in the vicinity of the SeaTech marina and the Port Everglades turning basin in water depths of 2 to 15...
Show moreA detailed study of a novel method for high-speed acoustic communications in ports and shallow water is presented. A series of field experiments, coupled with simulated results using an acoustic channel model have been conducted to outline the optimal modulation schemes for use in the highly reverberant and Doppler dominated shallow water acoustic channel. Field experiments were conducted in the vicinity of the SeaTech marina and the Port Everglades turning basin in water depths of 2 to 15 meters and ranges of between 25 and 75 meters. An automated FAU acoustic modem transmitted BPSK and QPSK modulated messages centered at 300 kHz, with a source level of 173 dB re 1pPa and a symbol bandwidth of 25, 50 or 75 kHz. The coded rate varied from 25000 to 150000 bits per second. These high data rates are made possible using a high resolution Decision Feedback Equalizer with an efficient Doppler compensation process. The results of this study demonstrate the ability of such a system to transmit video images in a shallow water environment.
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Date Issued
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2007
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PURL
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http://purl.flvc.org/fau/fd/FA00012504
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Subject Headings
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Underwater acoustics, Deep-sea sounding, Seawater--Acoustic properties
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Format
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Document (PDF)
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Title
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pH determination of concrete pore water by a leaching technique for various concrete mixtures.
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Creator
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Sitton, Izic., Florida Atlantic University, Hartt, William H., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
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Abstract/Description
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A pH determination technique of concrete pore water by means of leaching OH- ions from powdered samples was developed. This method was then evaluated in terms of sample size, extent of dilution, leaching period, the type of leaching, calcium hydroxide error, and titration scatter. Based upon variations of the above parameters it was concluded that a maximum amount of hydroxide ions was released into solution for samples with the smallest particle size within a 24 hours static leaching period....
Show moreA pH determination technique of concrete pore water by means of leaching OH- ions from powdered samples was developed. This method was then evaluated in terms of sample size, extent of dilution, leaching period, the type of leaching, calcium hydroxide error, and titration scatter. Based upon variations of the above parameters it was concluded that a maximum amount of hydroxide ions was released into solution for samples with the smallest particle size within a 24 hours static leaching period. A 50ml dilution volume proved optimum with regard to filtration and titration. Under the above circumstances calcium hydroxide dissolution did not seem to pose a significant source of error. Furthermore, repeatability of the measurements was good and titration scatter was determined to be about 0.05 pH units. This method was used to determine the pH of samples containing different amounts of fly ash or silica fume additions as well as plain cement (control) samples. A drop in OH- concentration, that is pH, was detected with increasing pozzolanic addition. The results are discussed with the context of the degree of corrosion mitigation afforded by these pozzolans.
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Date Issued
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1996
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PURL
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http://purl.flvc.org/fcla/dt/15364
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Subject Headings
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Concrete--Corrosion, Seawater corrosion, Concrete--Testing, Leaching
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Format
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Document (PDF)
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Title
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Effect of strain rate and temperature on the stress corrosion cracking tendency of engineering alloys in acidified seawater.
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Creator
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Kundalgurki, Srivatsa G., Florida Atlantic University, Lipka, Stephen M., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
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Abstract/Description
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The stress corrosion cracking (SCC) tendencies of several engineering alloys were studied in an acidified seawater environment as a function of applied strain rate and electrolyte temperature. The selected alloys included austenitic stainless steels 304L, 316L, 904L and A-286 (an iron-based superalloy at two heat treatments yielding ultimate tensile strengths of 130 and 200 ksi), Inconel 718 (220 ksi ultimate tensile strength) and Hastelloys C-22 and C-276. The slow strain rate test technique...
Show moreThe stress corrosion cracking (SCC) tendencies of several engineering alloys were studied in an acidified seawater environment as a function of applied strain rate and electrolyte temperature. The selected alloys included austenitic stainless steels 304L, 316L, 904L and A-286 (an iron-based superalloy at two heat treatments yielding ultimate tensile strengths of 130 and 200 ksi), Inconel 718 (220 ksi ultimate tensile strength) and Hastelloys C-22 and C-276. The slow strain rate test technique was used to evaluate the SCC strain rate dependency of each alloy at extension rates of 4.7 x 10^-6, 4.7 x 10^-4 and 4.7 x 10^-3 mm/sec. The effect of electrolyte temperature was evaluated at 38C and 60C at a single extension rate of 4.7 x 10^-5 mm/sec. Control specimens were tested in a laboratory air environment at an extension rate of 4.7 x 10^-5 mm/sec. Various mechanical parameters of the specimens tested in the corrosive medium were compared with those of control specimens to quantify the degree of cracking. Fractographic evidence of SCC was obtained using scanning electron microscopy (SEM). An attempt was made to correlate SCC tendency with the alloy's passivation kinetics and microstructure. Atmospheric exposure testing was performed in a simulated space shuttle launch pad environment for selected alloys.
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Date Issued
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1992
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PURL
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http://purl.flvc.org/fcla/dt/14853
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Subject Headings
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Alloys--Stress corrosion, Stress corrosion, Sea-water corrosion
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Format
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Document (PDF)
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Title
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Influence of direct electrical current upon specific volume of mortar in sea water.
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Creator
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Le Floch, Anne., Florida Atlantic University, Hartt, William H., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
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Abstract/Description
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Hollow, cylindrical mortar specimens of 0.4 water-cement ratio were prepared without reinforcement and exposed to flowing natural sea water for periods up to one year. Direct currents of 2, 10 and 50 mA were impressed between a mixed metal-oxide titanium substrate electrode positioned within each of these two zones, with a different electrolyte supply and exhaust for the cylinder core and exterior surface. Linear expansion of the specimens was evaluated as a function of exposure duration from...
Show moreHollow, cylindrical mortar specimens of 0.4 water-cement ratio were prepared without reinforcement and exposed to flowing natural sea water for periods up to one year. Direct currents of 2, 10 and 50 mA were impressed between a mixed metal-oxide titanium substrate electrode positioned within each of these two zones, with a different electrolyte supply and exhaust for the cylinder core and exterior surface. Linear expansion of the specimens was evaluated as a function of exposure duration from the output of embedded strain gages and from dimensional measurement of cylinder length and diameter. It was found that expansion of specimens exposed to direct current exceeded baseline ones (no current). Also, the expansion was anisotropic in that different magnitudes and trends were apparent for the diameter versus length directions. The expansion under free exposure (no current) was determined to be a function of specimen size and of the direction of measurement relative to the cast specimen face.
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Date Issued
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1995
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PURL
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http://purl.flvc.org/fcla/dt/15214
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Subject Headings
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Concrete--Deterioration, Concrete--Corrosion, Seawater corrosion, Cathodic protection
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Format
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Document (PDF)
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Title
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The role of symbiotic dinoflagellates in the temperature-induced bleaching response of Aiptasia pallida.
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Creator
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Perez, Santiago F., Florida Atlantic University, Marsh, G. Alex, Cook, Clayton B., Brooks, W. Randy, Koch, Marguerite
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Abstract/Description
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Bleaching of reef corals and other cnidarians symbiotic with zooxanthellae can be attributed to the stress response of the host, algae or both. To determine if zooxanthellae are involved in the bleaching process, I infected a single strain of sea anemone, Aiptasia pallida with zooxanthellae from different hosts. I measured expulsion of the algae from the host during 24-hour incubations at 25, 32 and 34C, as well as photosynthetic rates at these temperatures. Photosynthesis and expulsion of...
Show moreBleaching of reef corals and other cnidarians symbiotic with zooxanthellae can be attributed to the stress response of the host, algae or both. To determine if zooxanthellae are involved in the bleaching process, I infected a single strain of sea anemone, Aiptasia pallida with zooxanthellae from different hosts. I measured expulsion of the algae from the host during 24-hour incubations at 25, 32 and 34C, as well as photosynthetic rates at these temperatures. Photosynthesis and expulsion of zooxanthellae were inversely and directly proportional to elevated temperatures, respectively. Photosynthesis and expulsion of zooxanthellae isolated from Condylactis gigantea showed the greatest sensitivity to elevated temperature when compared to other zooxanthellae tested. These results suggest that zooxanthellae have a function in the bleaching process and that this function may be related to their photosynthetic response. Thus, the differential tolerance of zooxanthellae to stress could partly explain the spatial variability characteristic of coral-bleaching episodes.
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Date Issued
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1999
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PURL
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http://purl.flvc.org/fcla/dt/15698
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Subject Headings
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Dinoflagellates, Sea anemones, Coral reef ecology, Seawater--Thermal properties
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Format
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Document (PDF)
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Title
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A comparison of nutrient-limited productivity in Sargassum natans from neritic vs. oceanic waters of the western North Atlantic Ocean.
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Creator
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Lapointe, Brian E.
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Date Issued
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1995
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PURL
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http://purl.flvc.org/FCLA/DT/3343820
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Subject Headings
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Sargassum, Marine algae--North Atlantic Ocean, Seaweed, Seawater--Analysis
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Format
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Document (PDF)
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Title
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Spectrum fatigue of welded structural steel in sea water.
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Creator
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Clark, A. M., Qian, D., Hartt, William H., Martin, P. E., Czarnecki, M. F., Harbor Branch Oceanographic Institute
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Date Issued
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1983
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PURL
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http://purl.flvc.org/fau/fd/FA00007432
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Subject Headings
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Offshore structures--Welded joints--Fatigue, Steel, Structural--Fatigue, Seawater
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Format
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Document (PDF)
Pages