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1

Optimizing Rougher Flotation Parameters of the Esfordi Phosphate Ore  

Microsoft Academic Search

The performance of rougher flotation of the Esfordi phosphate ore was studied by a series of batch flotation tests. A central composite experimental design was employed to evaluate the effects of six main parameters on the recovery of phosphate and iron into the concentrate. A response surface model was fitted to results for the recovery of P2O5, which showed that

A. Dehghani; A. Azizi; S. H. Mojtahedzadeh; Kh. Gharibi

2012-01-01

2

Optimizing Rougher Flotation Parameters of the Esfordi Phosphate Ore  

Microsoft Academic Search

The performance of rougher flotation of the Esfordi phosphate ore was studied by a series of batch flotation tests. A central composite experimental design was employed to evaluate the effects of six main parameters on the recovery of phosphate and iron into the concentrate.A response surface model was fitted to results for the recovery of P2O5, which showed that the

A. Dehghani; A. Azizi; S. H. Mojtahedzadeh; Kh. Gharibi

2011-01-01

3

The selective flotation of pentlandite from a nickel ore  

Microsoft Academic Search

Nickel sulphide ores containing pentlandite, pyrrhotite and talc have traditionally been treated by bulk sulphide flotation, an approach which seeks to maximise nickel recovery and talc rejection but which does not reject pyrrhotite. Concentrates have therefore been of moderate grade containing as much pyrrhotite as pentlandite or more.In this research a procedure has been devised which rejects much of the

G. D. Senior; W. J. Trahar; P. J. Guy

1995-01-01

4

Direct Flotation of Niobium Oxide Minerals from Carbonatite Niobium Ores  

NASA Astrophysics Data System (ADS)

Currently the recovery of niobium oxide minerals from carbonatite niobium ores relies on the use of non-selective cationic collectors. This leads to complicated process flowsheets involving multiple desliming and multiple reverse flotation stages, and low niobium recovery. In this research, anionic collectors that are capable of strong chemisorption on the niobium minerals were studied with the objective of directly floating the niobium oxide minerals from the carbonatite ores. In the flotation of both high purity minerals and Niobec ores, it was shown that the combination of hydroxamic acid and sodium metaphosphate was an effective reagent scheme for the direct flotation of niobium oxide from its ores. Batch flotation on the Niobec Mill Feed showed that over 95% of niobium oxide was recovered into a rougher concentrate that was less than 47% of the original feed mass. Preliminary cleaning tests showed that the reagent scheme could also be used to upgrade the rougher concentrate, although the depression of iron oxide minerals required further study. X-ray photoelectron spectroscopic (XPS) measurement results confirm that OHA (octyl hydroxamic acid) could chemisorb on pyrochlore surface while only physically adsorb on calcite, judging by the chemical shifts of electron binding energies in the elements in both OHA and the mineral surfaces. When hydroxamic acid was adsorbed on calcite surface, the binding energies of the N 1s electrons, at 400.3 eV, did not shift. However, after adsorption on pyrochlore, the N 1s binding energy peak split into two peaks, one at a binding energy of around 399 eV, representing chemically adsorbed OHA, the other at between 400 and 401 eV. The experimental data suggested a strong chemisorption of the OHA on pyrochlore surface in the form of a vertical head-on orientation of the OHA molecules so that the pyrochlore was strongly hydrophobized even at low OHA concentrations, followed by possibly randomly oriented physisorbed OHA molecules. On the other hand, OHA only physisorbed on calcite forming a horizontally oriented monolayer of OHA. The results explain the observed selectivity of hydroxamic acid in the flotation of niobium oxide minerals from carbonatite niobium ores.

Ni, Xiao

5

Estimated water requirements for the conventional flotation of copper ores  

USGS Publications Warehouse

This report provides a perspective on the amount of water used by a conventional copper flotation plant. Water is required for many activities at a mine-mill site, including ore production and beneficiation, dust and fire suppression, drinking and sanitation, and minesite reclamation. The water required to operate a flotation plant may outweigh all of the other uses of water at a mine site, [however,] and the need to maintain a water balance is critical for the plant to operate efficiently. Process water may be irretrievably lost or not immediately available for reuse in the beneficiation plant because it has been used in the production of backfill slurry from tailings to provide underground mine support; because it has been entrapped in the tailings stored in the TSF, evaporated from the TSF, or leaked from pipes and (or) the TSF; and because it has been retained as moisture in the concentrate. Water retained in the interstices of the tailings and the evaporation of water from the surface of the TSF are the two most significant contributors to water loss at a conventional flotation circuit facility.

Bleiwas, Donald I.

2012-01-01

6

Dolomite flotation of high magnesium phosphate ores using fatty acid soap collectors  

NASA Astrophysics Data System (ADS)

The separation of dolomite from apatite has been recognized as one of the most difficult subjects in mineral processing due to the similarities in their physiochemical properties. In this study, selective surfactants were used with a fatty acid soap collector to improve the flotation performance of separating dolomite from high magnesium phosphate ores. Three surfactants, diethyl phthalate (DP), Tween-80 (TW) and derivative of sulfonate salt (DSS1) were used. Hallimond cell flotation was conducted using pure dolomite sample to determine the effects of various factors including dosages, particle size, Ca2+ ions and slimes on the dolomite flotation recovery. The results showed that the surfactants can significantly improve dolomite flotation performance by increasing collecting ability and tolerating the effect of calcium ions and slime contents. The stirrer-tank cell batch flotation tests were carried out using two natural high magnesium phosphate ore samples containing 3.3% and 1.5% MgO. The test results showed that the surfactant DP could improve dolomite flotation at low dosages, and DSS1 could enhance the separation of dolomite from phosphate by improving both collecting ability and flotation selectivity. When 10% of DSS1 was used with the fatty acid soap as collector, at least 10% more dolomite can be removed with less P2O5 loss. The effectiveness of the surfactant DSS1 in enhancing dolomite flotation was further demonstrated in modified packed column flotation with natural dolomitic phosphate ore sample. The addition of the surfactant DSS1 into fatty acid soap collector could improve its frothability and froth stability, and reduce the bubble size. It has been found that the dolomite flotation performance has a close relationship with the frothability and froth stability of the collector.

Gu, Zhengxing

7

The impact of bacteria of circulating water on apatite-nepheline ore flotation  

Microsoft Academic Search

A new phenomenon has been identified and studied–the impact of bacteria on the benefication process of non-sulphide ores using circulating water supply–a case study of apatite-nepheline ore. It is shown that bacteria deteriorate the floatability of apatite due to their interaction with active centres of calcium-containing minerals and intense flocculation, resulting in a decrease of the flotation process selectivity thus

G. A. Evdokimova; A. Sh. Gershenkop; N. V. Fokina

2012-01-01

8

Effects of High Pressure ORE Grinding on the Efficiency of Flotation Operations  

NASA Astrophysics Data System (ADS)

This article discusses issues related to the impact of the high pressure comminution process on the efficiency of the copper ore flotation operations. HPGR technology improves the efficiency of mineral resource enrichment through a better liberation of useful components from waste rock as well as more efficient comminution of the material. Research programme included the run of a laboratory flotation process for HPGR crushing products at different levels of operating pressures and moisture content. The test results showed that products of the high-pressure grinding rolls achieved better recoveries in flotation processes and showed a higher grade of useful components in the flotation concentrate, in comparison to the ball mill products. Upgrading curves have also been marked in the following arrangement: the content of useful component in concentrate the floatation recovery. All upgrading curves for HPGR products had a more favourable course in comparison to the curves of conventionally grinded ore. The results also indicate that various values of flotation recoveries have been obtained depending on the machine operating parameters (i.e. the operating pressure), and selected feed properties (moisture).

Saramak, Daniel; Krawczykowska, Aldona; M?ynarczykowska, Anna

2014-10-01

9

The impact of bacteria of circulating water on apatite-nepheline ore flotation.  

PubMed

A new phenomenon has been identified and studied-the impact of bacteria on the benefication process of non-sulphide ores using circulating water supply-a case study of apatite-nepheline ore. It is shown that bacteria deteriorate the floatability of apatite due to their interaction with active centres of calcium-containing minerals and intense flocculation, resulting in a decrease of the flotation process selectivity thus deteriorating the quality of concentrate. Based on the comparative analysis of primary sequences of 16S rRNA genes, there have been identified dominating bacteria species, recovered from the circulating water used at apatite-nepheline concentrating mills, and their phylogenetic position has been determined. All the bacteria were related to ?-Proteobacteria, including the Acinetobacter species, Pseudomonas alcaliphila, Ps. plecoglossicida, Stenotrophomonas rhizophila. A method of non-sulphide ores flotation has been developed with consideration of the bacterial factor. It consists in use of small concentrations of sodium hypochlorite, which inhibits the development of bacteria in the flotation of apatite-nepheline ores. PMID:22320692

Evdokimova, G A; Gershenkop, A Sh; Fokina, N V

2012-01-01

10

Water leaching of titanium from ore flotation residue  

SciTech Connect

Copper ore tailings were tested for the stability of titanium submitted to water leaching in three different reactor systems (agitated vessel, bioreactor and percolated fixed-bed column). For each of these systems, titanium extraction did not exceed 1% of the available metal. Biomass removed from ore residue adsorbed a small part of the titanium with sorption capacities below 20-30 mg g{sup -1}, but most of this biomass was sequestered in the ore residue. Oxygen and carbon dioxide concentrations were monitored and changes in concentration correlated with bacteria development at the initial stage of the process and to fungal development in the latter stages.

Jaworska, Malgorzata M.; Guibal, Eric

2003-07-01

11

Magnetic and flotation studies of banded hematite quartzite (BHQ) ore for the production of pellet grade concentrate  

NASA Astrophysics Data System (ADS)

To identify and establish beneficiation techniques for banded hematite quartzite (BHQ) iron ore, a comprehensive research on BHQ ore treatment was carried out. The BHQ ore was assayed as 38.9wt% Fe, 42.5wt% SiO2, and 1.0wt% Al2O3. In this ore, hematite and quartz are present as the major mineral phases where goethite, martite, and magnetite are present in small amounts. The liberation of hematite particles can be enhanced to about 82% by reducing the particle size to below 63 ?m. The rejection of silica particles can be obtained by magnetic and flotation separation techniques. Overall, the BHQ ore can be enriched to 65.3wt% Fe at 61.9% iron recovery. A flowsheet has been suggested for the commercial exploitation of the BHQ ore.

Das, B.; Mishra, B. K.; Prakash, S.; Das, S. K.; Reddy, P. S. R.; Angadi, S. I.

2010-12-01

12

Optimization of flotation variables for the recovery of hematite particles from BHQ ore  

NASA Astrophysics Data System (ADS)

The technology for beneficiation of banded iron ores containing low iron value is a challenging task due to increasing demand of quality iron ore in India. A flotation process has been developed to treat one such ore, namely banded hematite quartzite (BHQ) containing 41.8wt% Fe and 41.5wt% SiO2, by using oleic acid, methyl isobutyl carbinol (MIBC), and sodium silicate as the collector, frother, and dispersant, respectively. The relative effects of these variables have been evaluated in half-normal plots and Pareto charts using central composite rotatable design. A quadratic response model has been developed for both Fe grade and recovery and optimized within the experimental range. The optimum reagent dosages are found to be as follows: collector concentration of 243.58 g/t, dispersant concentration of 195.67 g/t, pH 8.69, and conditioning time of 4.8 min to achieve the maximum Fe grade of 64.25% with 67.33% recovery. The predictions of the model with regard to iron grade and recovery are in good agreement with the experimental results.

Rath, Swagat S.; Sahoo, Hrushikesh; Das, B.

2013-07-01

13

Effectiveness of sodium silicate as gangue depressants in iron ore slimes flotation  

NASA Astrophysics Data System (ADS)

The recovery of iron from the screw classifier overflow slimes by direct flotation was studied. The relative effectiveness of sodium silicates with different silica-to-soda mole ratios as depressants for silica and silicate bearing minerals was investigated. Silica-to-soda mole ratio and silicate dosage were found to have significant effect on the separation efficiency. The results show that an increase of Fe content in the concentrate is observed with concomitant reduction in SiO2 and Al2O3 levels when a particular type of sodium silicate at a proper dosage is used. The concentrate of 58.89wt% Fe, 4.68wt% SiO2, and 5.28wt% Al2O3 with the weight recovery of 38.74% and the metal recovery of 41.13% can be obtained from the iron ore slimes with 54.44wt% Fe, 6.72wt% SiO2, and 6.80wt% Al2O3, when Na2SiO3 with a silica-to-soda mole ratio of 2.19 is used as a depressant at a feed rate of 0.2 kg/t.

Rao, Danda Srinivas; Vijayakumar, Tadiparthi Venkata; Rao, Sripada Subba; Prabhakar, Swarna; Raju, Guntamadugu Bhaskar

2011-10-01

14

N,N-dialkyl-N 1 -arenesulfonylformamidines: prospective reagents for collective flotation of sulfide ores of ferrous and rare metals  

Microsoft Academic Search

For example, formamidinesulfmic acid NH2(NH)CSO2H is used as a sulfiding agent in the flotation of polymetallic silver-containing ores. When 200-250 g\\/ton of this reagent is fed into the pulp in the presence of potassium butylxanthate, the recovery of silver is increased by 13%, along with an improvement of the concentrate quality. N,N-Dialkylformamides HCON(C4Hs)(CH2CH2)nH, where n = 3-10, at a dosage

O. N. Bel’kova; G. G. Levkovskaya; A. N. Mirskova

1997-01-01

15

Concentration of K-feldspar from a pegmatitic feldspar ore by flotation  

Microsoft Academic Search

Abundant reserves of Na-feldspar (albite) and K-feldspar (orthoclase or microcline) are found in granites, syenite, tracite and pegmatites. As both feldspar minerals have similar chemical structure and physicochemical properties, their separation is challenging. Flotation is known to be the only technique to enable their separation. The fundamentals on the separation of these minerals were well documented in our earlier studies.

C. Karaguzel; I. Gulgonul; C. Demir; M. Cinar; M. S. Celik

2006-01-01

16

[Selection of a community of acidochemolithotrophic microorganisms with a high oxidation rate of pyrrhotite- containing sulphide ore flotatation concentrate].  

PubMed

A community of acidochemolithotrophic microorganisms with a high oxidation rate of pyrrhotite-containing sulphide ore flotation concentrate was selected. The Acidithiobacillus caldus OP-1 and Ferroplasma acidiphilum OP-2 cultures were identified to be dominating members. The presence of the Acidithio- bacillusferrooxidans OP-3, Leptospirillumferriphilum OP-4, and Sulfobacillus thermosulfidooxidans OP-5 cultures in the community's composition was also mentioned. The analysis results of solid residues of the process showed a greater elemental sulfur oxidation level and gold recovery when the initial pH value in tank I was maintained at a level of 1.8-2.0 (90.5%) rather than 1.6-1.8 (86.3%). PMID:25474872

Kondrat'eva, T F; Pivovarova, T A; Bulaev, A G; Moshchanetski?, P V; Tsaplina, I A; Grigor'eva, N V; Zhuravleva, A E; Melamud, V S; Bely?, A V

2013-01-01

17

The theory of flotation  

NASA Technical Reports Server (NTRS)

A brief summary of the fundamentals of the Linear theory of flotation is given. The theory by no means contradicts the previous Laminar theory or even the thermodynamics (Wark-Siedler), rather it is a refinement of the known Hardy-Langmuir-Harkin conceptions for the case when there are not two phases and phase boundaries, but rather three phases and corresponding phase boundary edges. The appearance of such three-phase boundaries (ore, water, air) is characteristic for modern flotation methods.

Ostwald, Wolfgang

1988-01-01

18

Mineralogical distribution of some minor and trace elements during a laboratory flotation processing of Neves-Corvo ore (Portugal)  

Microsoft Academic Search

Neves-Corvo mine (SOMINCOR, Portugal) is one of the most important underground mines now operating in Europe. It treats a heterogeneous massive sulphide deposit, which is mainly copper and\\/or tin rich. The extracted ore is processed to obtain two types of concentrates (Cu and Tin) whose purity is affected by some minor (As and Sb) and trace (Hg, Se, Cd) elements.

M Benzaazoua; P Marion; L Liouville-Bourgeois; R Joussemet; R Houot; A Franco; A Pinto

2002-01-01

19

Influence of the Water Composition on the Selectivity of Apatite Flotation  

Microsoft Academic Search

The effect of ionic species on the flotation selectivity of apatite was evaluated. Water containing fluoride, calcium, magnesium, and phosphate was used in the flotation experiments carried out in a flotation column for coarse and fine phosphate ore. The selectivity of apatite over ferrous and siliceous gangue was investigated. Coarse and fine ores showed different sensitivities according to the ion

Mariana A. dos Santos; Ricardo C. Santana; Fabiano Capponi; Carlos H. Ataíde; Marcos A. S. Barrozo

2012-01-01

20

Influence of the Water Composition on the Selectivity of Apatite Flotation  

Microsoft Academic Search

The effect of ionic species on the flotation selectivity of apatite was evaluated. Water containing fluoride, calcium, magnesium and phosphate was used in the flotation experiments carried out in a flotation column for coarse and fine phosphate ore. The selectivity of apatite over ferrous and siliceous gangue was investigated. Coarse and fine ores showed different sensitivities according to the ion

Mariana A. dos Santos; Ricardo C. Santana; Fabiano Capponi; Carlos H. Ataíde; Marcos A. S. Barrozo

2011-01-01

21

Flotation and agglomerate concentration of nonmetallic minerals  

Microsoft Academic Search

This paper discusses the flotation of phosphates, limestone, magnesite and dolomite, graphite, coal, carbons and chars, bituminous sands, fluorite, zircon, talc, barite, kyanite, chromite, cassiterite, feldspar, beryl, spodumene, nephelite, quartz, mica, sericite, clay, bauxite, tungsten minerals, ilmenite and rutile, manganese ore, oxidized iron ore, sulfur, cryolite, and alunite and alumina. The agglomeration of phosphate, limestone, soluble salines, kyanite, fluorite, and

Ralston

1938-01-01

22

Magmatic ore deposits in layered intrusions - Descriptive model for reef-type PGE and contact-type Cu-Ni-PGE deposits  

USGS Publications Warehouse

Layered, ultramafic to mafic intrusions are uncommon in the geologic record, but host magmatic ore deposits containing most of the world's economic concentrations of platinum-group elements (PGE) (figs. 1 and 2). These deposits are mined primarily for their platinum, palladium, and rhodium contents (table 1). Magmatic ore deposits are derived from accumulations of crystals of metallic oxides, or immiscible sulfide, or oxide liquids that formed during the cooling and crystallization of magma, typically with mafic to ultramafic compositions. "PGE reefs" are stratabound PGE-enriched lode mineralization in mafic to ultramafic layered intrusions. The term "reef" is derived from Australian and South African literature for this style of mineralization and used to refer to (1) the rock layer that is mineralized and has distinctive texture or mineralogy (Naldrett, 2004), or (2) the PGE-enriched sulfide mineralization that occurs within the rock layer. For example, Viljoen (1999) broadly defined the Merensky Reef as "a mineralized zone within or closely associated with an unconformity surface in the ultramafic cumulate at the base of the Merensky Cyclic Unit." In this report, we will use the term PGE reef to refer to the PGE-enriched mineralization, not the host rock layer. Within a layered igneous intrusion, reef-type mineralization is laterally persistent along strike, extending for the length of the intrusion, typically tens to hundreds of kilometers. However, the mineralized interval is thin, generally centimeters to meters thick, relative to the stratigraphic thickness of layers in an intrusion that vary from hundreds to thousands of meters. PGE-enriched sulfide mineralization is also found near the contacts or margins of layered mafic to ultramafic intrusions (Iljina and Lee, 2005). This contact-type mineralization consists of disseminated to massive concentrations of iron-copper-nickel-PGE-enriched sulfide mineral concentrations in zones that can be tens to hundreds of meters thick. The modes and textures of the igneous rocks hosting the mineralization vary irregularly on the scale of centimeters to meters; autoliths and xenoliths are common. Mineralization occurs in the igneous intrusion and in the surrounding country rocks. Mineralization can be preferentially localized along contact with country rocks that are enriched in sulfur-, iron-, or CO2-bearing lithologies. Reef-type and contact-type deposits, in particular those in the Bushveld Complex, South Africa, are the world's primary source of platinum and rhodium (tables 2 and 3; fig. 2). Reef-type PGE deposits are mined only in the Bushveld Complex (Merensky Reef and UG2), the Stillwater Complex (J-M Reef), and the Great Dyke (Main Sulphide Layer). PGE-enriched contact-type deposits are only mined in the Bushveld Complex. The other deposits in tables 2 and 3 are undeveloped; some are still under exploration.

Zientek, Michael L.

2012-01-01

23

Pulp level control for flotation — options and a CSIRO laboratory perspective  

Microsoft Academic Search

The separation efficiency for recovering minerals from a flotation process, is influenced by factors relating to the mixture of ore and water. Whether flotation is performed in a large mineral processing plant or a laboratory on a small-scale, the setting and control of level is required to establish an optimum steady state function between the minerals, air, water and flotation

J. A. Hamilton; P. J. Guy

2001-01-01

24

Coral Reefs Coral Reefs  

E-print Network

1 Coral Reefs Coral Reefs Coral Reef Formation Scleractinian Coral Polyps · Scleractinia = stony Growth Reef Building Corals · Reef building corals are colonial ­ create large 'coral heads' that may productivity. ­ So no phytoplankton ­ So no zooplankton ­ So no food for corals Reef Building Corals

Cochran-Stafira, D. Liane

25

HGMS of tin ore tailings  

Microsoft Academic Search

Two samples of Bolivian tin ore tailings have been subjected to High Gradient Magnetic Separation (HGMS) for the purpose of increasing the tin content, and reducing the iron content which interferes with smelting. The Colavi mine tailing was the discarded product of a froth flotation process and contains about 0.7% by weight of valuable tin. The Atoroma tailing was the

M. Arellano; D. Kelland

1979-01-01

26

Beneficiation of borax by reverse flotation in boron saturated brine.  

PubMed

Flotation is one of the plausible methods for recovering borax fines discharged as fine waste to the tailings dam in the Kirka borax processing plant. A literature review dealing with the flotation behavior of boron minerals reveals that clay minerals in the boron ores coat boron minerals and thus deteriorate the quality of boron concentrates produced by direct flotation. The main objective of this study is therefore to recover borax fines from the tailings of the concentrator by reverse flotation. A three-level-factor experimental design was used to determine the main and interaction effects of variables selected on the metallurgical performance of reverse flotation. An analysis of variance for experimental results indicates that interaction effects of the variables for concentrate quality and recovery of B2O3 is nonsignificant and the most important variable for grade of concentrate and recovery is the collector dosage. It is shown that a concentrate assaying 11.25% B2O3 with 89.90% B2O3 recovery could be produced by means of single-stage (rougher) reverse flotation. Additionally, in order to produce a sufficient-quality concentrate, a multistage reverse flotation scheme involving rougher, scavenger, and two cleaners was devised. A final concentrate containing 23.47% B2O3 with 81.78% B2O3 recovery was obtained from these tests. The reverse flotation method can be thus considered as an important option for the beneficiation of borax fines. PMID:15939429

Cafer Cilek, Emin; Uresin, Hasan

2005-10-15

27

1. Introduction Prior to the development of flotation and smelting  

E-print Network

collectively as "zinc oxide" deposits, could again become an important source of metallic zinc. Based"-type deposits containing hydrated zinc silicates that were formed by residual surface oxidation of primary1. Introduction Prior to the development of flotation and smelting processes for zinc sulphide ores

Boni, Maria

28

Intensification of flotation process for certain nonsulfide minerals  

Microsoft Academic Search

In the practice of beneficiation of phosphorite, tin, fluorite, tungsten, and other ores from Russian deposits by means of flotation, the most commonly used collector reagents are oleic acid and materials from the chemical industry and forest products industry that contain fatty acids; for the most part, these collectors do not have the required selectivity for the minerals being recovered.

I. A. Nosov

1994-01-01

29

Role of biosolids on hydrophobic properties of sulfide ores  

Microsoft Academic Search

The effect of biosolids on hydrophobic properties of sulfides ores was studied. The principal components of biosolids are humic substances, mainly humic acid, and phosphorus compounds. The feasibility of using biosolids as collector for copper sulfide ores (CSO) was performed through zetapotential measurements, FT-IR analysis and film flotation tests. Addition of different dosages of biosolids, a commercial humic acid (CHA),

L. Reyes-Bozo; R. Herrera-Urbina; M. Escudey; A. Godoy-Faúndez; C. Sáez-Navarrete; M. Herrera; R. Ginocchio

2011-01-01

30

Ore Minerals  

NSDL National Science Digital Library

This three part lab introduces sulfides and other ore minerals. Part one - Ore Minerals: Students fill in a table giving the metal, formula, and mineral group of several ore minerals. Part two - Box of Rocks: Students examine trays of ore minerals and record their physical properties, composition, habit, occurence, economic value, and use and answer questions about color, luster, density, transparency, and availability. Part three - Famous Digs: Students answer a series of questions related to famous ore deposits.

Dexter Perkins

31

Host-rock controlled epigenetic, hydrothermal metasomatic origin of the Bayan Obo REEFe-Nb ore deposit, Inner Mongolia, P.R.C.  

USGS Publications Warehouse

Bayan Obo, a complex rare earth element (REE)FeNb ore deposit, located in Inner Mongolia, P.R.C. is the world's largest known REE deposit. The deposit is chiefly in a marble unit (H8), but extends into an overlying unit of black shale, slate and schist unit (H9), both of which are in the upper part of the Middle Proterozoic Bayan Obo Group. Based on sedimentary structures, the presence of detrital quartz and algal fossil remains, and the 16-km long geographic extent, the H8 marble is a sedimentary deposit, and not a carbonatite of magmatic origin, as proposed by some previous investigators. The unit was weakly regionally metamorphosed (most probably the lower part of the green schist facies) into marble and quartzite prior to mineralization. Tectonically, the deposit is located on the northern flank of the Sino-Korean craton. Many hypotheses have been proposed for the origin of the Bayan Obo deposit; the studies reported here support an epigenetic, hydrothermal, metasomatic origin. Such an origin is supported by field and laboratory textural evidence; 232Th/208Pb internal isochron mineral ages of selected monazite and bastnaesite samples; 40Ar/39Ar incremental heating minimum mineral ages of selected alkali amphiboles; chemical compositions of different generations of both REE ore minerals and alkali amphiboles; and evidence of host-rock influence on the various types of Bayan Obo ores. The internal isochron ages of the REE minerals indicate Caledonian ages for various episodes of REE and Fe mineralization. No evidence was found to indicate a genetic relation between the extensive biotite granitic rocks of Hercynian age in the mine region and the Bayan Obo are deposit, as suggested by previous workers. ?? 1992.

Chao, E.C.T.; Back, J.M.; Minkin, J.A.; Yinchen, R.

1992-01-01

32

Ore and coal beneficiation method  

SciTech Connect

This patent describes a method for the separation of iron pyrite from a pulverized mineral ore comprising iron pyrites as a first constituent and a second constituent selected from the group consisting of coal and non-ferrous metal ores by air froth flotation of an aqueous pulp of the pulverized mineral ore. The improvement comprises incorporating in the pulp from about 0.02 to about 1 pound per ton of mineral of a composition comprising hydroxyacetic acid, xanthan gum, sodium silicate, and water wherein the acid content of the composition is from about 0.1 to about 69 percent by weight of the composition, the xanthan gum is from about 0.01 to about 10 percent by weight of the composition; and the ratio by weight of sodium silicate to hydroxyacetic acid is in the range of from about 0 to about 0.5.

Abadi, K.

1987-10-27

33

A study of the interfacial chemistry of pyrite and coal in fine coal cleaning using flotation  

SciTech Connect

Surface oxidation, surface charge, and flotation properties have been systematically studied for coal, coal-pyrite and ore-pyrite. Electrochemical studies show that coal-pyrite exhibits much higher and more complex surface oxidation than ore-pyrite and its oxidation rate depends strongly on the carbon/coal content. Flotation studies indicate that pyrites have no self-induced floatability. Fuel oil significantly improves the floatability of coal and induces considerable flotation for coal-pyrite due to the hydrophobic interaction of fuel oil with the carbon/coal inclusions on the pyrite surface. Xanthate is a good collector for ore-pyrite but a poor collector for coal and coal-pyrite. The results from thermodynamic calculations, flotation and zeta potential measurements show that iron ions greatly affect the flotation of pyrite with xanthate and fuel oil. Various organic and inorganic chemicals have been examined for depressing coal-pyrite. It was found, for the first time, that sodium pyrophosphate is an effective depressant for coal-pyrite. Solution chemistry shows that pyrophosphate reacts with iron ions to form stable iron pyrophosphate complexes. Using pyrophosphate, the complete separation of pyrite from coal can be realized over a wide pH range at relatively low dosage.

Jiang, C.

1993-12-31

34

33 CFR 183.322 - Flotation materials.  

Code of Federal Regulations, 2010 CFR

...CONTINUED) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Flotation Requirements for Outboard Boats Rated for Engines of 2 Horsepower or Less General § 183.322 Flotation materials. (a) Flotation materials must meet the requirements in §...

2010-07-01

35

33 CFR 183.322 - Flotation materials.  

Code of Federal Regulations, 2012 CFR

...CONTINUED) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Flotation Requirements for Outboard Boats Rated for Engines of 2 Horsepower or Less General § 183.322 Flotation materials. (a) Flotation materials must meet the requirements in §...

2012-07-01

36

33 CFR 183.322 - Flotation materials.  

Code of Federal Regulations, 2013 CFR

...CONTINUED) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Flotation Requirements for Outboard Boats Rated for Engines of 2 Horsepower or Less General § 183.322 Flotation materials. (a) Flotation materials must meet the requirements in §...

2013-07-01

37

33 CFR 183.322 - Flotation materials.  

Code of Federal Regulations, 2011 CFR

...CONTINUED) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Flotation Requirements for Outboard Boats Rated for Engines of 2 Horsepower or Less General § 183.322 Flotation materials. (a) Flotation materials must meet the requirements in §...

2011-07-01

38

33 CFR 183.322 - Flotation materials.  

Code of Federal Regulations, 2014 CFR

...CONTINUED) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Flotation Requirements for Outboard Boats Rated for Engines of 2 Horsepower or Less General § 183.322 Flotation materials. (a) Flotation materials must meet the requirements in §...

2014-07-01

39

21 CFR 890.3175 - Flotation cushion.  

Code of Federal Regulations, 2011 CFR

...AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Prosthetic Devices § 890.3175 Flotation cushion. (a) Identification. A flotation...

2011-04-01

40

21 CFR 890.3175 - Flotation cushion.  

Code of Federal Regulations, 2010 CFR

...AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Prosthetic Devices § 890.3175 Flotation cushion. (a) Identification. A flotation...

2010-04-01

41

Determination of flotation reagents used in tin-mining by capillary electrophoresis  

Microsoft Academic Search

Alkyl xanthates (O-alkyl dithiocarbonates) and phosphonates are important organic collectors for the flotation of metals from crude ore. Leaching from waste dumps into river and ground water, these substances can cause environmental pollution.A capillary electrophoretic method for the routine determination of ethyl, isopropyl, hexyl xanthate, and styrene phosphonate has been developed. Separation within 12 min could be achieved in borate

F Hissner; B Daus; J Mattusch; K Heinig

1999-01-01

42

PhysicoChemical Factors Affecting the Separation of Cassiterite and Fluorite by Froth Flotation  

Microsoft Academic Search

Cassiterite flotation is achieved industrially with some anionic collectors. However, the presence of fluorite in primary tin ores usually poses a problem in relation to the selectivity between the two minerals. In this work, a comparative study was undertaken involving adsorption, electrophoretic mobility and suspension stability measurements of both cassiterite and fluorite as a function of oleic acid concentration. These

JOSE FARIAS OLIVEIRA; RUPEN ADAMIAN

1992-01-01

43

Geothermal energy for the increased recovery of copper by flotation enhancement  

SciTech Connect

The possible use of geothermal energy (a) to speed the recovery of copper from ore flotation and/or leaching of flotation tailings and (b) to utilize geothermal brines to replace valuable fresh water in copper flotation operations was evaluated. Geothermal energy could be used to enhance copper and molybdenum recovery in mineral flotation by increasing the kinetics of the flotation process. In another approach, geothermal energy could be used to heat the leaching solution which might permit greater copper recovery using the same residence time in a tailings leach facility. Since there is no restriction on the temperature of the leaching fluid, revenues generated from the additional copper recovered would be greater for tailings leach operations than for other types of leach operations (for example, dump leaching operation) for which temperature restrictions exist. The estimated increase in total revenues resulting from two percent increase copper recovery in a 50,000 tons ore/day plant was estimated to be over $2,000,000 annually. It would require an estimated geothermal investment of about $2,130,000 for a geothermal well and pumping system. Thus, the capital investment would be paid out in about one year. Furthermore, considerable savings of fresh waters and process equipment are possible if the geothermal waters can be used directly in the mine-mill operations, which is believed to be practical.

White, D.H.; Goldstone, L.A.

1982-08-01

44

Investigations on the Collector Reagent Development for the Recovery of Cassiterite from the Gravity Tails of a Low Grade Indian Tin Ore  

Microsoft Academic Search

Results of the experimental studies carried out for developing a flowsheet for the recovery of cassiterite from the gravity tails of a low grade lode type tin ore (Tosham, Haryana) from India by froth flotation using three different collector reagents — alkyl phosphonic acid, sodium sulfosuccinamate and alkyl phosphoric acid ester are presented. The studies include micro-flotation of high purity

T. SREENIVAS; C. MANOHAR

1998-01-01

45

Hydrogen bubble flotation of silica  

Microsoft Academic Search

In this study the flotation recovery of silica using air, and molecular and electrolytically-generated hydrogen was investigated. For comparison of air and molecular hydrogen recoveries, a laboratory Denver, type D12, flotation machine was used. For both gases, pH of the suspension, gas flow rate, concentration of collector and frother, solids concentration, particle size and speed of impeller were kept constant.

S. W. Donne; G. M. Evans

2010-01-01

46

77 FR 19937 - Inflatable Personal Flotation Devices  

Federal Register 2010, 2011, 2012, 2013, 2014

...Standard for Safety for Marine Buoyant Devices''; UL 1180, ``UL Standard for Safety...Inflatable Recreational Personal Flotation Devices''; and UL 1191, ``UL Standard for Safety for Components for Personal Flotation Devices.'' The section that...

2012-04-03

47

33 CFR 183.302 - Flotation requirements.  

Code of Federal Regulations, 2012 CFR

...CONTINUED) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Flotation Requirements for Outboard Boats Rated for Engines of 2 Horsepower or Less General § 183.302 Flotation requirements. Each boat to which this subpart applies must be...

2012-07-01

48

33 CFR 183.302 - Flotation requirements.  

Code of Federal Regulations, 2013 CFR

...CONTINUED) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Flotation Requirements for Outboard Boats Rated for Engines of 2 Horsepower or Less General § 183.302 Flotation requirements. Each boat to which this subpart applies must be...

2013-07-01

49

33 CFR 183.302 - Flotation requirements.  

Code of Federal Regulations, 2010 CFR

...CONTINUED) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Flotation Requirements for Outboard Boats Rated for Engines of 2 Horsepower or Less General § 183.302 Flotation requirements. Each boat to which this subpart applies must be...

2010-07-01

50

33 CFR 183.302 - Flotation requirements.  

Code of Federal Regulations, 2014 CFR

...CONTINUED) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Flotation Requirements for Outboard Boats Rated for Engines of 2 Horsepower or Less General § 183.302 Flotation requirements. Each boat to which this subpart applies must be...

2014-07-01

51

33 CFR 183.302 - Flotation requirements.  

Code of Federal Regulations, 2011 CFR

...CONTINUED) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Flotation Requirements for Outboard Boats Rated for Engines of 2 Horsepower or Less General § 183.302 Flotation requirements. Each boat to which this subpart applies must be...

2011-07-01

52

Great Barrier Reef  

Atmospheric Science Data Center

article title:  Australia's Great Barrier Reef     View Larger Image ... not a single reef, but a vast maze of reefs, passages, and coral cays (islands that are part of the reef). This nadir true-color image was ...

2013-04-16

53

Coral Reefs  

NSDL National Science Digital Library

In this video, Jonathan examines the biology of coral reefs and their importance to the marine ecosystem. Please see the accompanying lesson plan that discusses pH and ocean acidification for educational objectives, discussion points and classroom activities.

Productions, Jonathan B.

2012-03-01

54

Selective flotation of inorganic sulfides from coal  

DOEpatents

Pyritic sulfur is removed from coal or other carbonaceous material through the use of humic acid as a coal flotation depressant. Following the removal of coarse pyrite, the carbonaceous material is blended with humic acid, a pyrite flotation collector and a frothing agent within a flotation cell to selectively float pyritic sulfur leaving clean coal as an underflow.

Miller, Kenneth J. (Floreffe, PA); Wen, Wu-Wey (Murrysville, PA)

1989-01-01

55

Selective flotation of inorganic sulfides from coal  

DOEpatents

Pyritic sulfur is removed from coal or other carbonaceous material through the use of humic acid as a coal flotation depressant. Following the removal of coarse pyrite, the carbonaceous material is blended with humic acid, a pyrite flotation collector and a frothing agent within a flotation cell to selectively float pyritic sulfur leaving clean coal as an underflow. 1 fig., 2 tabs.

Miller, K.J.; Wen, Wu-Wey

1988-05-31

56

Coral reef restoration  

Microsoft Academic Search

Coral reefs are widely recognized for concentration of biological activity, fisheries and tourism, coastal protection, geological processes, and aesthetic wonder. A principal cause of reef damage in Florida is ships running into reefs. The other major human impact on Florida’s reefs is dredging for beach renourishment and channel maintenance. In response to chronic reef damage, federal and state agencies and

Walter C Jaap

2000-01-01

57

Reef grief  

NASA Astrophysics Data System (ADS)

As the first of the world's ecosystems faces extermination at our hands, coral reef ecologist Peter Sale -- Assistant Director of the Institute of Water, Environment and Health at the United Nations University in Ontario, Canada, and author of Our Dying Planet (published this autumn) -- talks to Nature Climate Change.

2011-10-01

58

21 CFR 880.5150 - Nonpowered flotation therapy mattress.  

Code of Federal Regulations, 2013 CFR

...false Nonpowered flotation therapy mattress. 880.5150 Section 880.5150...5150 Nonpowered flotation therapy mattress. (a) Identification. A nonpowered flotation therapy mattress is a mattress intended for...

2013-04-01

59

21 CFR 880.5550 - Alternating pressure air flotation mattress.  

Code of Federal Regulations, 2010 CFR

...Alternating pressure air flotation mattress. 880.5550 Section 880.5550...Alternating pressure air flotation mattress. (a) Identification. An alternating pressure air flotation mattress is a device intended for medical...

2010-04-01

60

21 CFR 880.5550 - Alternating pressure air flotation mattress.  

Code of Federal Regulations, 2014 CFR

...Alternating pressure air flotation mattress. 880.5550 Section 880.5550...Alternating pressure air flotation mattress. (a) Identification. An alternating pressure air flotation mattress is a device intended for medical...

2014-04-01

61

21 CFR 880.5150 - Nonpowered flotation therapy mattress.  

Code of Federal Regulations, 2011 CFR

...false Nonpowered flotation therapy mattress. 880.5150 Section 880.5150...5150 Nonpowered flotation therapy mattress. (a) Identification. A nonpowered flotation therapy mattress is a mattress intended for...

2011-04-01

62

21 CFR 880.5150 - Nonpowered flotation therapy mattress.  

Code of Federal Regulations, 2014 CFR

...false Nonpowered flotation therapy mattress. 880.5150 Section 880.5150...5150 Nonpowered flotation therapy mattress. (a) Identification. A nonpowered flotation therapy mattress is a mattress intended for...

2014-04-01

63

21 CFR 880.5550 - Alternating pressure air flotation mattress.  

Code of Federal Regulations, 2012 CFR

...Alternating pressure air flotation mattress. 880.5550 Section 880.5550...Alternating pressure air flotation mattress. (a) Identification. An alternating pressure air flotation mattress is a device intended for medical...

2012-04-01

64

21 CFR 880.5150 - Nonpowered flotation therapy mattress.  

Code of Federal Regulations, 2010 CFR

...false Nonpowered flotation therapy mattress. 880.5150 Section 880.5150...5150 Nonpowered flotation therapy mattress. (a) Identification. A nonpowered flotation therapy mattress is a mattress intended for...

2010-04-01

65

21 CFR 880.5550 - Alternating pressure air flotation mattress.  

Code of Federal Regulations, 2013 CFR

...Alternating pressure air flotation mattress. 880.5550 Section 880.5550...Alternating pressure air flotation mattress. (a) Identification. An alternating pressure air flotation mattress is a device intended for medical...

2013-04-01

66

21 CFR 880.5550 - Alternating pressure air flotation mattress.  

Code of Federal Regulations, 2011 CFR

...Alternating pressure air flotation mattress. 880.5550 Section 880.5550...Alternating pressure air flotation mattress. (a) Identification. An alternating pressure air flotation mattress is a device intended for medical...

2011-04-01

67

21 CFR 880.5150 - Nonpowered flotation therapy mattress.  

Code of Federal Regulations, 2012 CFR

...false Nonpowered flotation therapy mattress. 880.5150 Section 880.5150...5150 Nonpowered flotation therapy mattress. (a) Identification. A nonpowered flotation therapy mattress is a mattress intended for...

2012-04-01

68

33 CFR 183.325 - Flotation test for persons capacity.  

Code of Federal Regulations, 2014 CFR

...CONTINUED) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Flotation Requirements for Outboard Boats Rated for Engines of 2 Horsepower or Less Tests § 183.325 Flotation test for persons capacity. Flotation standard. When the conditions...

2014-07-01

69

33 CFR 183.222 - Flotation material and air chambers.  

Code of Federal Regulations, 2012 CFR

...BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Flotation Requirements for Outboard Boats Rated for Engines of More Than 2 Horsepower General § 183.222 Flotation material and air chambers. (a) Flotation materials must meet the requirements...

2012-07-01

70

33 CFR 183.222 - Flotation material and air chambers.  

Code of Federal Regulations, 2014 CFR

...BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Flotation Requirements for Outboard Boats Rated for Engines of More Than 2 Horsepower General § 183.222 Flotation material and air chambers. (a) Flotation materials must meet the requirements...

2014-07-01

71

33 CFR 183.222 - Flotation material and air chambers.  

Code of Federal Regulations, 2011 CFR

...BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Flotation Requirements for Outboard Boats Rated for Engines of More Than 2 Horsepower General § 183.222 Flotation material and air chambers. (a) Flotation materials must meet the requirements...

2011-07-01

72

33 CFR 183.225 - Flotation test for persons capacity.  

Code of Federal Regulations, 2011 CFR

...BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Flotation Requirements for Outboard Boats Rated for Engines of More Than 2 Horsepower Tests § 183.225 Flotation test for persons capacity. Flotation standard. When the conditions prescribed...

2011-07-01

73

33 CFR 183.225 - Flotation test for persons capacity.  

Code of Federal Regulations, 2014 CFR

...BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Flotation Requirements for Outboard Boats Rated for Engines of More Than 2 Horsepower Tests § 183.225 Flotation test for persons capacity. Flotation standard. When the conditions prescribed...

2014-07-01

74

33 CFR 183.325 - Flotation test for persons capacity.  

Code of Federal Regulations, 2011 CFR

...CONTINUED) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Flotation Requirements for Outboard Boats Rated for Engines of 2 Horsepower or Less Tests § 183.325 Flotation test for persons capacity. Flotation standard. When the conditions...

2011-07-01

75

33 CFR 183.222 - Flotation material and air chambers.  

Code of Federal Regulations, 2013 CFR

...BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Flotation Requirements for Outboard Boats Rated for Engines of More Than 2 Horsepower General § 183.222 Flotation material and air chambers. (a) Flotation materials must meet the requirements...

2013-07-01

76

33 CFR 183.225 - Flotation test for persons capacity.  

Code of Federal Regulations, 2012 CFR

...BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Flotation Requirements for Outboard Boats Rated for Engines of More Than 2 Horsepower Tests § 183.225 Flotation test for persons capacity. Flotation standard. When the conditions prescribed...

2012-07-01

77

33 CFR 183.225 - Flotation test for persons capacity.  

Code of Federal Regulations, 2013 CFR

...BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Flotation Requirements for Outboard Boats Rated for Engines of More Than 2 Horsepower Tests § 183.225 Flotation test for persons capacity. Flotation standard. When the conditions prescribed...

2013-07-01

78

33 CFR 183.222 - Flotation material and air chambers.  

Code of Federal Regulations, 2010 CFR

...BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Flotation Requirements for Outboard Boats Rated for Engines of More Than 2 Horsepower General § 183.222 Flotation material and air chambers. (a) Flotation materials must meet the requirements...

2010-07-01

79

33 CFR 183.325 - Flotation test for persons capacity.  

Code of Federal Regulations, 2013 CFR

...CONTINUED) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Flotation Requirements for Outboard Boats Rated for Engines of 2 Horsepower or Less Tests § 183.325 Flotation test for persons capacity. Flotation standard. When the conditions...

2013-07-01

80

33 CFR 183.325 - Flotation test for persons capacity.  

Code of Federal Regulations, 2012 CFR

...CONTINUED) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Flotation Requirements for Outboard Boats Rated for Engines of 2 Horsepower or Less Tests § 183.325 Flotation test for persons capacity. Flotation standard. When the conditions...

2012-07-01

81

Sharp maxima in the flotation rate  

Microsoft Academic Search

The steady-state flotation rates of crystalline tin oxide, quartz, and glass, measured as a function of the reduced surfactant\\u000a concentration (c\\/CMC), show sharp maxima at concentration values which are characteristic for a given mineral, and independent of the pH.\\u000a A comparison of the flotation measurements using glass beads and ground glass particles shows that the flotation kinetics\\u000a are strongly inflenced

M. Pitsch; K. Heckmann; H.-H. Kohler; J. Strnad

82

Sewage treatment-flotation apparatus  

SciTech Connect

Solids-liquid separation, wherein a solids-liquid mixture containing dissolved oxygen-containing gas is circulated around a circulatory system comprising a downcomer and a riser, part of the mixture in the riser being introduced into a flotation chamber in which the hydrostatic pressure gradually decreases as the mixture flows upwards, with consequent release from solution of gas bubbles which carry solid particles to the top of the mixture.

Hines, D.A.; Jones, R.T.; Roesler, F.C.

1981-03-03

83

Principles of Air Flotation Technology  

Microsoft Academic Search

\\u000a Air flotation, in all its variations, is an efficient way to separate light particulates and oils from wastewater. Particulates\\u000a that adhere to an air bubble, either by adsorption or absorption, can be floated from the liquid phase. Polymers may be added\\u000a to improve the attachment of the particle to the bubble. Agglomerization of colloids into floc particles with the aid

Nazih K. Shammas; Gary F. Bennett

84

Research of Geochemical Associations of Nephelin Ores  

NASA Astrophysics Data System (ADS)

The instant paper concerns research of distribution petrogenic chemical members in urtit ore body of Kia-Shaltyrsk deposit. Rocks of the deposit are ore for producing alum earth. Actuality of the subject based on outlooks of detection noble metal ore-bearing (Au, Pt, Pd, Rh, Ru) in alkaline rocks of Siberia, including rocks of Kia-Shaltyrsk deposit (Kuznetsk Alatau). The main purpose of analysis of distribution of members is directed to detection of a non-uniformity of distribution of substance and segments enriched with alum earth and noble members. The basic solved problems are following: o Creation regression models of ore body; o Definition of cumulative distribution functions of members in a contour of ore body; o The analysis of the obtained outcomes in geologic terms. For construction regression models the full-scale data was used, which was presented by the results of the spectral and silicate analyses of gold and petrogenic members containing 130 assays arranged in ore body. A non-linear multiparameter model of the ore body based on components of nephelin ore using neural net approach was constructed. For each member the corresponding distribution function is produced. The model is constructed on the following members: Au, Al2O3, SiO2, Fe2O3, CaO, MgO, SO3, R2O ((Na2O+K2O) -1) and losses of burning. The error of model forecasting membersS concentrations was from 0.02 up to 20%. Large errors basically connected with assays located near contact of ore body and ad- jacent strata or with very high concentrations of members; also they can be connected with different genesis of rocks or superposition of other processes. The analysis of concentrations of members and normalised absolute errors of the fore- cast has shown, that all members can be sectioned into two groups: first: Al2O3, SiO2, R2O, Fe2O3 and second: Au, losses of burning, CaO, MgO, SO3. The distribution of 1 gold is tightly connected with calcium and losses of burning and spatially linked with zones of contact of ore body and adjacent wall rocks. Also it is possible to point, that the segments enriched with gold do not coincide with segments of high-alumna rocks but they are phase-opposite. High concentrations of alum earth, earth silicon, alkalis and low contents of ferric oxide, calcium and sulphur determine high-alumina rocks. Thus, one group of members determines high quality of nephelin ore, and the sec- ond U noble metal ore-bearing bound with members aggravating quality of nephelin ore. Therefore, it is possible to draw a conclusion, that the preliminary enrichment of nephelin ore with the help of flotation will allow to receive two kinds of high quality concentrate: aluminous and noblemetal. The research also allows developing ways of a practical solution of a problem of de- terioration quality of nephelin ore with increasing depth and, accordingly, increases its cost price. These problems apparently connected with economical planning of a production activity of the ore mine and the financial state of the alumnus plant. 2

Vulf, M.; Simonov, K.; Sazonov, A.

85

Selective flotation of phosphate minerals with hydroxamate collectors  

DOEpatents

A method is disclosed for separating phosphate minerals from a mineral mixture, particularly from high-dolomite containing phosphate ores. The method involves conditioning the mineral mixture by contacting in an aqueous in environment with a collector in an amount sufficient for promoting flotation of phosphate minerals. The collector is a hydroxamate compound of the formula; ##STR1## wherein R is generally hydrophobic and chosen such that the collector has solubility or dispersion properties it can be distributed in the mineral mixture, typically an alkyl, aryl, or alkylaryl group having 6 to 18 carbon atoms. M is a cation, typically hydrogen, an alkali metal or an alkaline earth metal. Preferably, the collector also comprises an alcohol of the formula, R'--OH wherein R' is generally hydrophobic and chosen such that the collector has solubility or dispersion properties so that it can be distributed in the mineral mixture, typically an alkyl, aryl, or alkylaryl group having 6 to 18 carbon atoms.

Miller, Jan D. (Salt Lake City, UT); Wang, Xuming (Salt Lake City, UT); Li, Minhua (Salt Lake City, UT)

2002-01-01

86

Microbubble flotation of fine coal. Final report  

SciTech Connect

Fine coal flotation has been a longstanding problem in industry. Coal particles below approximately 38 microns in diameter are difficult to float, and the process consumes large amounts of reagents. Hydrodynamic analyses have shown, however, that the use of air bubbles smaller than those that are generated in conventional flotation machines (0.2 to 3 mm diameter) can improve the flotation rate and, hence, the coal recovery. Theoretically, a tenfold reduction in average bubble size should result in a thousandfold increase in the flotation rate constant at a given gas flow rate. Therefore, work has been done to use microbubbles less than 100 microns in diameter for the flotation of fine coal particles. Seven different U.S. coal samples have been tested in the present work. The feed size varies from -100 mesh to -500 mesh. Flotation kinetics tests have been conducted on some of these coal samples as a function of bubble size at a constant gas flow rate. The results show a drastic improvement in flotation rate with the use of microbubbles, which may account for the improved recoveries obtained with the microbubble flotation technique. In addition, test results obtained with ultrafine coal samples (-20 microns) indicate that the microbubble flotation process is more selective than conventional flotation. This improved selectivity has been explained tentatively by the increased bubble loading and the reduced turbulence around the microbubbles. Various techniques have been employed to further enhance the selectivity of the process by minimizing the ash entrapment problem. To better understand the mechanisms of microbubble flotation, basic information regarding surface tension, contact angle, viscosity, streaming currents of microbubbles, electrophoretic mobilities of coal and mineral matter, and stability of microbubble suspensions has been obtained. 50 references, 42 figures, 9 tables.

Yoon, R. H.

1984-03-01

87

Author's personal copy Coral Reefs  

E-print Network

Author's personal copy Coral Reefs D E Burkepile and M E Hay, Georgia Institute of Technology Ecological Interactions on Coral Reefs Replenishment of Coral Reefs: The Role of Reproduction and Recruitment in the Ecology of Reefs Landscape Ecology of Coral Reefs: Connections of Coral Reefs to Mangrove and Seagrass

Burkepile, Deron

88

Journey to the Reef  

NSDL National Science Digital Library

Despite their experiences with a cartoon sponge, most elementary students know little about the diverse inhabitants of coral reefs. Therefore, with vivid photography and video, diverse coral reef inhabitants were brought to life for the author's fifth-gra

Bryson, Linda

2010-01-01

89

Jurassic Reef Park  

NSDL National Science Digital Library

This is a bilingual, educational website from Munich, Germany. The main feature is a virtual field trip to the reefs of the Jurassic period. Besides a view of the Jurassic reefs, their builders, and their ecological settings, there is also an emphasis on the importance of modern reefs as indicators of the state-of-health of the globe and evidence of how some changes in the composition of reefs may represent the forerunners of catastrophic, regional or global, environmental change.

Reinhold Leinfelder

90

Great Barrier Reef  

NSDL National Science Digital Library

This lesson addresses the environmental importance of coral reefs and the threats to the conservation of reefs. Through the process of gathering geographic information about a place (in this case, the Great Barrier Reef), students will learn how a geographic focus can sharpen their insights about a conservation issue.

91

Flotation selectivity of novel alkyl dicarboxylate reagents for apatite-calcite separation.  

PubMed

The investigation aims to demonstrate the conceptual thoughts behind developing mineral specific reagents for use in flotation of calcium containing ores. For this purpose, a series of dicarboxylate-based surfactants with varying distance between the carboxylate groups (one, two or three methylene groups) was synthesized. A surfactant with the same alkyl chain length but with only one carboxylate group was also synthesized and evaluated. The adsorption behavior of these new reagents on pure apatite and pure calcite surfaces was studied using Hallimond tube flotation, FTIR and ? potential measurements. The relation between the adsorption behavior of a given surfactant at a specific mineral surface and its molecular structure over a range of concentrations and pH values, as well as the region of maximum recovery, was established. It was found that one of the reagents, with a specific distance between the carboxylate groups, was much more selective for a particular mineral surface than the other homologues. For example, out of the four compounds synthesized, only the one where the carboxylate groups were separated by a single methylene group floated apatite but not calcite, whereas calcite was efficiently floated with the monocarboxylic reagent, but not with the other reagents synthesized. This selective adsorption of a given surfactant to a particular mineral surface relative to other mineral surfaces as evidenced in the flotation studies was substantiated by ? potential and infra-red spectroscopy data. PMID:25596367

Karlkvist, Tommy; Patra, Anuttam; Rao, Kota Hanumantha; Bordes, Romain; Holmberg, Krister

2015-05-01

92

FLOCCULATION-FLOTATION AIDS FOR TREATMENT OF COMBINED SEWER OVERFLOWS  

EPA Science Inventory

The objectives of this study were to investigate the flocculation/flotation characteristics of combined sewer overflow through laboratory and field testing. The concept involves the introduction of chemicals and buoyant flotation aids into the overflow and the subsequent cofloccu...

93

33 CFR 183.202 - Flotation and certification requirements.  

Code of Federal Regulations, 2014 CFR

...BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Flotation Requirements for Outboard Boats Rated for Engines of More Than 2 Horsepower General § 183.202 Flotation and certification requirements. Each boat to which this subpart applies must be...

2014-07-01

94

33 CFR 183.202 - Flotation and certification requirements.  

Code of Federal Regulations, 2012 CFR

...BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Flotation Requirements for Outboard Boats Rated for Engines of More Than 2 Horsepower General § 183.202 Flotation and certification requirements. Each boat to which this subpart applies must be...

2012-07-01

95

33 CFR 183.202 - Flotation and certification requirements.  

Code of Federal Regulations, 2011 CFR

...BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Flotation Requirements for Outboard Boats Rated for Engines of More Than 2 Horsepower General § 183.202 Flotation and certification requirements. Each boat to which this subpart applies must be...

2011-07-01

96

33 CFR 183.202 - Flotation and certification requirements.  

Code of Federal Regulations, 2013 CFR

...BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Flotation Requirements for Outboard Boats Rated for Engines of More Than 2 Horsepower General § 183.202 Flotation and certification requirements. Each boat to which this subpart applies must be...

2013-07-01

97

33 CFR 183.202 - Flotation and certification requirements.  

Code of Federal Regulations, 2010 CFR

...BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Flotation Requirements for Outboard Boats Rated for Engines of More Than 2 Horsepower General § 183.202 Flotation and certification requirements. Each boat to which this subpart applies must be...

2010-07-01

98

78 FR 49412 - Personal Flotation Devices Labeling and Standards  

Federal Register 2010, 2011, 2012, 2013, 2014

...Administration PFD Personal flotation device Pub. L. Public Law RA Regulatory...requirements for personal flotation devices (PFDs) fall under this authority...safety matter, as it is the primary means by which the manufacturer...Classification for Personal Flotation Devices (PFDs)'' (available...

2013-08-14

99

Artificial Coral Reefs  

NSDL National Science Digital Library

Coral reefs are among the most diverse ecosystems on the planet...and the most threatened. Artificial reefs may help stem the loss of these valuable and beautiful habitats, with shipwrecks, old subway cars, and other structures taking the place of living coral or rocky outcrops. The following Web sites introduce artificial reefs, reef ecology, and some ongoing efforts to establish reef communities in the U.S. and beyond. PBS's NATURE offers a fascinating look at the artificial reefs created by the thousands of shipwrecks and downed planes from World War II that riddle the South Pacific (1). This is the companion Web site to the documentary War Wrecks of the Coral Seas, and it includes some great multimedia features. The next site comes from the National Oceanic and Atmospheric Administration and contains an excellent photo gallery of coral ecosystems around the world (2). The collection includes six pages of artificial reef photos taken in the Pacific. The following site comes from the online companion to the BBC's acclaimed documentary series The Blue Planet. Based on the episode The Web of Life, this site offers a fun, multimedia challenge for learning about and testing one's knowledge of coral reefs (3). The site includes a section on artificial reefs (click on Take it Further). Next, an August 2001 segment from National Public Radio's All Things Considered explores efforts to create artificial reefs using decommissioned New York City subway cars -- a project of Delaware's Department of Natural Resources and Environmental Control in the Division of Fish and Wildlife (4). Likewise, the non-profit group Artificial Reefs of the Keys is working to bring a de-commissioned military ship to the Florida Keys (5). The New Jersey Scuba Diver Web site provides an excellent introduction to artificial reef ecology; focused on reefs in New Jersey, of course. The mini-tutorial comes courtesy of William Figly, Principal Fisheries Biologist for the New Jersey Artificial Reef Program (6). The Fall 2001 issue of California Wild, the magazine of the California Academy of Sciences, addresses the benefits and concerns of off shore oil rigs becoming artificial reefs (7). Finally, visitors will find dozens of news articles and Web links related to artificial reefs in this entry, a page from the New England Artificial Reef Society Web site (8).

Sohmer, Rachel.

100

Coral Reefs Under Stress  

NSDL National Science Digital Library

Coral reefs are more critical to an oceanâÂÂs health than you might think, and the effects of climate change and ocean acidification are effectively damaging and destroying most reefs in the world. Coral reefs provide many important ecosystem services, including: providing food, shelter, and meeting places for thousands of animals; anchoring sand for recreational beaches; and supplying building materials for remote peoples.

Peter Mumby (University of Exeter;)

2009-10-05

101

Reducibility of laterite ores  

NASA Astrophysics Data System (ADS)

The reducibility of several types of lateritic nickel bearing ores was investigated. The ores were reduced with hydrogen over a temperature range of 673 to 1273 K and reaction times from 5 to 80 minutes. The fraction of nickel, iron, and cobalt reduced to the metallic state was determined by leaching the reacted samples with a bromine-methanol solution followed by atomic absorption analysis for the individual elements. The reducibility of nickel increased with increasing iron concentration of the ore. Increased reduction temperature greatly raised the amount of nickel reduced for ores with high iron concentrations. The cobalt reducibility decreased with increasing iron concentration of the ore. Changes in reduction temperature affected cobalt reduction less than nickel reduction. The observed changes in reducibility have been attributed to the formation of phases which incorporate nickel and cobalt. The major ore components were plotted on the ternary phase diagram of the SiO2+(Al2O3)-MgO-FeO system. It is shown how this plot can be used to predict the reducibility of different types of lateritic ores.

Kawahara, M.; Toguri, J. M.; Bergman, R. A.

1988-04-01

102

Ocean World: Coral Reefs  

NSDL National Science Digital Library

Texas A&M University presents Ocean World, a Web-based educational resource for oceanography. The feature on coral reefs has the most direct life sciences application, with easy-to-navigate sections about the coral animal, coral reefs as the rainforests of the sea, symbiosis, ecosystem services, and coral reef threats and conservation. The Web site also includes a handy hypertext glossary, an interactive quiz, and annotated links to interesting Web sites, including sites that provide real-time reef images and data. While no formal lesson plans are provided, this Web site could be easily incorporated to a related classroom module for a range of grade levels.

103

Fluidized-bed combustion of flotation tailings  

Microsoft Academic Search

After mechanical water removal, the flotation tailings containing about 30% moisture are stored in silo (1) which is specially designed for this purpose. The lime required for desulphurizing the flue gas is stored in silo (2) Special silo-discharge device and weigh-feeders pass the two materials to the mixing screw in proportional rates in accordance with the sulphur content and guaranteed

Belting

1979-01-01

104

Selective flotation of cassiterite with benzohydroxamic acid  

Microsoft Academic Search

The flotation of cassiterite mineral from gangue with a collector benzohydroxamic acid (BHA), and the interactions between the BHA and cassiterite have been investigated. It is shown through microflotation that the BHA is able to flot cassiterite very well, calcite quite limitedly, and quartz not at all, so the selective separation of cassiterite–quartz mixture was readily achieved; while for the

X. Q. Wu; J. G. Zhu

2006-01-01

105

NOAA Coral Reef Watch Calcification Index of Coral Reef Ecosystems  

E-print Network

;Ocean `Acidification' pH CO3 2- CO2(aq) Wolf-Gladrow et al., 1999 www.niwascience + OHCO 22 -+ + 3HCOH32NOAA Coral Reef Watch Calcification Index of Coral Reef Ecosystems NOAANOAA''ss Coral Reef Watch:Coral) NOAA/NESDIS/STAR/SO and Coral Reef Conservation Program (CRCP) NOAA Coral Matrix Silver Spring

Kuligowski, Bob

106

Reducibility of laterite ores  

Microsoft Academic Search

The reducibility of several types of lateritic nickel bearing ores was investigated. The ores were reduced with hydrogen over\\u000a a temperature range of 673 to 1273 K and reaction times from 5 to 80 minutes. The fraction of nickel, iron, and cobalt reduced\\u000a to the metallic state was determined by leaching the reacted samples with a bromine-methanol solution followed by

M. Kawahara; J. M. Toguri; R. A. Bergman

1988-01-01

107

Exploring the reefs Introduction  

E-print Network

. · Explain what factors affect the quality of a satellite image. #12;2 I. IKONOS Data The IKONOS data used chain. Many people depend on the reefs for food and economy (fish, shellfish, etc.). Coral reefs thrive include satellite images and any other data that are obtained by a hands-off observational approach. SONAR

Wright, Dawn Jeannine

108

Great Barrier Reef  

NASA Technical Reports Server (NTRS)

A better than average view of the Great Barrier Reef was captured by SeaWiFS on a recent overpass. There is sunglint northeast of the reef and there appears to be some sort of filamentous bloom in the Capricorn Channel.

2002-01-01

109

Capitol Reef Cliff  

USGS Multimedia Gallery

A sandstone cliff near the entrance of Capitol Reef National Park. Capitol Reef is primarily made up of sandstone formations within the Waterpocket Fold, monocline that extends nearly 100 miles. A monocline is a step-like fold in rock strata that can resemble an enormous wrinkle in the earth. The tr...

110

Capitol Reef Sandstone Cliff  

USGS Multimedia Gallery

A sandstone cliff within Capitol Reef National Park. Capitol Reef is primarily made up of sandstone formations within the Waterpocket Fold, monocline that extends nearly 100 miles. A monocline is a step-like fold in rock strata that can resemble an enormous wrinkle in the earth....

111

Capitol Reef Panorama  

USGS Multimedia Gallery

A panorama of some of the sandstone formations within Capitol Reef National Park. Capitol Reef is primarily made up of sandstone formations within the Waterpocket Fold, monocline that extends nearly 100 miles. A monocline is a step-like fold in rock strata that can resemble an enormous wrinkle in th...

112

Capitol Reef Cliff  

USGS Multimedia Gallery

A sandstone cliff near the entrance of Capitol Reef National Park. Capitol Reef is primarily made up of sandstone formations within the Waterpocket Fold, monocline that extends nearly 100 miles. A monocline is a step-like fold in rock strata that can resemble an enormous wrinkle in the earth. This l...

113

Capitol Reef Cliff  

USGS Multimedia Gallery

A sandstone cliff near the entrance of Capitol Reef National Park. Capitol Reef is primarily made up of sandstone formations within the Waterpocket Fold, monocline that extends nearly 100 miles. A monocline is a step-like fold in rock strata that can resemble an enormous wrinkle in the earth.&n...

114

Capitol Reef Sandstone Monolith  

USGS Multimedia Gallery

A sandstone monolith within Capitol Reef National Park. Capitol Reef is primarily made up of sandstone formations within the Waterpocket Fold, monocline that extends nearly 100 miles. A monocline is a step-like fold in rock strata that can resemble an enormous wrinkle in the earth....

115

Reefs in Crisis  

NSDL National Science Digital Library

This online article, from "The Biodiversity Crisis: Losing What Counts", walks students through the risks humans pose to the survival of coral reefs and conservation efforts. It discusses the forces behind damage to the reefs and recent protection efforts, including the creation of sanctuaries, good land management, and public awareness campaigns.

116

The Coral Reef Environmental \\  

Microsoft Academic Search

Coral reefs have been increasingly reported as ecosystems in severe “crisis” and decline, with estimates of irreparably damaged reefs to be around 54%, and possible losses of 15-20% more over the next half-century. The urgency to mitigate these declines has increased in recent years as the effects of global climate change have become apparent alongside steadily increasing population pressures in

Bärbel G. Bischof

2010-01-01

117

Assessing the ‘deep reef refugia’ hypothesis: focus on Caribbean reefs  

Microsoft Academic Search

Coral reefs in shallow-water environments (<30 m) are in decline due to local and global anthropogenic stresses. This has\\u000a led to renewed interest in the ‘deep reef refugia’ hypothesis (DRRH), which stipulates that deep reef areas (1) are protected\\u000a or dampened from disturbances that affect shallow reef areas and (2) can provide a viable reproductive source for shallow\\u000a reef areas following

P. Bongaerts; T. Ridgway; E. M. Sampayo; O. Hoegh-Guldberg

2010-01-01

118

33 CFR 149.331 - What are the requirements for hybrid personal flotation devices?  

Code of Federal Regulations, 2010 CFR

... false What are the requirements for hybrid personal flotation devices? 149.331...331 What are the requirements for hybrid personal flotation devices? (a...that the use and stowage of all commercial hybrid personal flotation devices...

2010-07-01

119

Pyrite Flotation With Xanthate Under Alkaline Conditions --Application to Environmental Desulfurisation  

E-print Network

Pyrite Flotation With Xanthate Under Alkaline Conditions -- Application to Environmental,3 and M Aubertin4 ABSTRACT The extensive literature on sulfide flotation indicates that pyrite poorly floats under alkaline condition. Xanthate concentration has a positive effect on pyrite flotation

Aubertin, Michel

120

Composition of the near-reef zooplankton at Heron Reef, Great Barrier Reef  

Microsoft Academic Search

Using a light trap, zooplankton was sampled at three stations at Heron Reef, Great Barrier Reef: (a) a typical patch reef in the Heron lagoon, (b) a site in 8 m water on the southern slope of Heron reef, and (c) a station approximately 300 m south of (b), in the open water of the channel between Heron and Wistari

P. F. Sale; P. S. McWilliam; D. T. Anderson

1976-01-01

121

Laboratory study of electro-coagulation–flotation for water treatment  

Microsoft Academic Search

An electro-coagulation–flotation process has been developed for water treatment. This involved an electrolytic reactor with aluminium electrodes and a separation\\/flotation tank. The water to be treated passed through the reactor and was subjected to coagulation\\/flotation, by Al(III) ions dissolved from the electrodes, the resulting flocs floating after being captured by hydrogen gas bubbles generated at cathode surfaces. Apparent current efficiencies

Jia-Qian Jiang; Nigel Graham; Cecile André; Geoff H. Kelsall; Nigel Brandon

2002-01-01

122

Flotation machine and process for removing impurities from coals  

DOEpatents

The present invention is directed to a type of flotation machine that combines three separate operations in a single unit. The flotation machine is a hydraulic separator that is capable of reducing the pyrite and other mineral matter content of a coal. When the hydraulic separator is used with a flotation system, the pyrite and certain other minerals particles that may have been entrained by hydrodynamic forces associated with conventional flotation machines and/or by the attachment forces associated with the formation of microagglomerates are washed and separated from the coal. 4 figs.

Szymocha, K.; Ignasiak, B.; Pawlak, W.; Kulik, C.; Lebowitz, H.E.

1997-02-11

123

Flotation machine and process for removing impurities from coals  

DOEpatents

The present invention is directed to a type of flotation machine that combines three separate operations in a single unit. The flotation machine is a hydraulic separator that is capable of reducing the pyrite and other mineral matter content of a coal. When the hydraulic separator is used with a flotation system, the pyrite and certain other mineral particles that may have been entrained by hydrodynamic forces associated with conventional flotation machines and/or by the attachment forces associated with the formation of microagglomerates are washed and separated from the coal. 4 figs.

Szymocha, K.; Ignasiak, B.; Pawlak, W.; Kulik, C.; Lebowitz, H.E.

1995-12-05

124

Flotation machine and process for removing impurities from coals  

DOEpatents

The present invention is directed to a type of flotation machine that combines three separate operations in a single unit. The flotation machine is a hydraulic separator that is capable of reducing the pyrite and other mineral matter content of a coal. When the hydraulic separator is used with a flotation system, the pyrite and certain other minerals particles that may have been entrained by hydrodynamic forces associated with conventional flotation machines and/or by the attachment forces associated with the formation of microagglomerates are washed and separated from the coal.

Szymocha, Kazimierz (Edmonton, CA); Ignasiak, Boleslaw (Edmonton, CA); Pawlak, Wanda (Edmonton, CA); Kulik, Conrad (Newark, CA); Lebowitz, Howard E. (Mountain View, CA)

1995-01-01

125

Flotation machine and process for removing impurities from coals  

DOEpatents

The present invention is directed to a type of flotation machine that combines three separate operations in a single unit. The flotation machine is a hydraulic separator that is capable of reducing the pyrite and other mineral matter content of a coal. When the hydraulic separator is used with a flotation system, the pyrite and certain other minerals particles that may have been entrained by hydrodynamic forces associated with conventional flotation machines and/or by the attachment forces associated with the formation of microagglomerates are washed and separated from the coal.

Szymocha, Kazimierz (Edmonton, CA); Ignasiak, Boleslaw (Edmonton, CA); Pawlak, Wanda (Edmonton, CA); Kulik, Conrad (Newark, CA); Lebowitz, Howard E. (Mountain View, CA)

1997-01-01

126

Elk Valley coal implements smartcell flotation technology  

SciTech Connect

In anticipation of future raw coal containing higher fines content, Elk Valley Coal Corp.'s Greenhills Operations upgraded their fines circuit to include Wemco SmartCells in March 2007. Positive results were immediately achieved increasing the average flotation tailings ash by 16%. With this increase in yield the SmartCells project paid for itself in less than eight months. 2 figs., 1 tab., 1 photo.

Stirling, J.C. [Elk Valley Coal Corporation, Elkford, BC (Canada)

2008-06-15

127

Separation via flotation, spectrophotometric speciation, and determination of vanadium(IV) in wastes of power stations.  

PubMed

1-(2-Hydroxy-4-methoxybenzophenone)-4-phenylthiosemicarbazone (HMBPT) was investigated as a new reagent for the flotation of vanadium(IV). At pH approximately 1.5, vanadium(IV) forms a 1:1 pale-violet complex with HMBPT in aqueous solution. An intense clear violet layer was formed after flotation, by adding an oleic acid (HOL) surfactant. The composition of the float was 1:1 [V(IV)]:[HMBPT]. A highly selective and sensitive spectrophotometric procedure was proposed for the determination of microamounts of V(IV) as its floated complex. The molar absorptivities of the V(IV)-HMBPT and V(IV)-HMBPT-HOL systems were 0.4 x 10(4) and 0.12 x 10(5) L mol(-1) cm(-1) at 560 nm, respectively. The formation constants of the species formed in the presence and absence of HOL were 4.6 x 10(7) and 8.7 x 10(5) L mol(-1), respectively. Beer's law was obeyed up to 1 x 10(-4) mol L(-1) in the aqueous layer as well as in the oleic acid layer. The HMBPT-V(IV) complexes formed in the aqueous solution and scum layer were characterized by elemental analysis, infrared and UV spectrophotometric studies. The mode of chelation between V(IV) and HMBPT is proposed to be due to a reaction between the protonated bidentate HMBPT ligand and V(IV) through the S=C and N=C groups. Interferences from various foreign ions were avoided by adding excess HMBPT and/or Na2S2O3 as a masking agent. The proposed flotation method was successfully applied to the analysis of V(IV) in synthetic mixtures, wastes of power stations, simulated samples and in real ores. The separation mechanism is discussed. PMID:16317901

Akl, Magda Ali; El-Asmy, Ahmed A; Yossef, Wafaa M

2005-11-01

128

Introduction to ore geology  

SciTech Connect

This textbook on ore geology is for second and third year undergraduates and closely parallels the undergraduate course given in this subject at England's University of Leicester. The volume covers three major areas: (1) principles of ore geology, (2) examples of the most important types of ore deposits, and (3) mineralization in space and time. Many chapters have been thoroughly revised for this edition and a chapter on diamonds has been added. Chapters on greisen and pegmatite have also been added, the former in response to the changing situation in tin mining following the recent tin crisis, and the latter in response to suggestions from geologists in a number of overseas countries. Some chapters have been considerably expanded and new sections added, including disseminated gold deposits and unconformity-associated uranium deposits. The author also expands on the importance of viewing mineral deposits from an economic standpoint.

Evans, A.M.

1987-01-01

129

38. HULETT ORE UNLOADERS IN MOTION; UNLOADING CANADIAN RED ORE ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

38. HULETT ORE UNLOADERS IN MOTION; UNLOADING CANADIAN RED ORE FROM THE GEORGE M. CARL.' VIEW LOOKING EAST. (Also see OH-18-14, OH-18-39, and OH-18-40) - Pennsylvania Railway Ore Dock, Lake Erie at Whiskey Island, approximately 1.5 miles west of Public Square, Cleveland, Cuyahoga County, OH

130

14. HULETT ORE UNLOADERS IN MOTION; UNLOADING CANADIAN RED ORE ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

14. HULETT ORE UNLOADERS IN MOTION; UNLOADING CANADIAN RED ORE FROM THE 'GEORGE M. CAR.' VIEW LOOKING EAST. (Also see OH-18-38, OH-18-39, and OH-18-40.) - Pennsylvania Railway Ore Dock, Lake Erie at Whiskey Island, approximately 1.5 miles west of Public Square, Cleveland, Cuyahoga County, OH

131

A preliminary investigation into the effect of pressure on flotation performance  

NASA Astrophysics Data System (ADS)

In a previous study, various pyrite depressants were examined to improve the flotation performance of a copper-sulfide ore containing tetrahedrite (Cu12Sb4S13). Optimal results from this study were used to examine the effect of elevation on recovery and grade. Tests were conducted at elevations of 3,350 meters, 1,735 meters, 610 meters, and-760 meters, consisting of five repetitive experiments for statistical analysis. The experiments were performed both with and without airflow control. Tests were also performed in a glove box at Montana Tech of The University of Montana to mimic the pressure conditions. Results indicate that both recovery and grade are dependent on pressure via bubble size and airflow, suggesting that pressurized fl otation cells should be considered for operations, particularly those at high elevation. Economics are extremely favorable for implementation because ensuing capital expenses are inconsequential with minimal time for return-on-investment.

Young, Courtney A.

2007-10-01

132

Coral Reef Ecosystems  

NASA Astrophysics Data System (ADS)

Coral reefs are geological structures of significant dimensions, constructed over millions of years by calcifying organisms. The present day reef-builders are hard corals belonging to the order Scleractinia, phylum Cnidaria. The greatest concentrations of coral reefs are in the tropics, with highest levels of biodiversity situated in reefs of the Indo-West Pacific region. These ecosystems have provided coastal protection and livelihood to human populations over the millennia. Human activities have caused destruction of these habitats, the intensity of which has increased alarmingly since the latter decades of the twentieth century. The severity of this impact is directly related to exponential growth rates of human populations especially in the coastal areas of the developing world. However, a more recently recognized phenomenon concerns disturbances brought about by the changing climate, manifested mainly as rising sea surface temperatures, and increasing acidification of ocean waters due to greater drawdown of higher concentrations of atmospheric carbon dioxide. Management efforts have so far not kept pace with the rates of degradation, so that the spatial extent of damaged reefs and the incidences of localized extinction of reef species are increasing year after year. The major management efforts to date consist of establishing marine protected areas and promoting the active restoration of coral habitats.

Yap, Helen T.

133

The Role of High Molecular Weight Polyethylene Oxide in Reducing Quartz Gangue Entrainment in Chalcopyrite Flotation by Xanthate Collectors  

NASA Astrophysics Data System (ADS)

Fine particles pose two challenging problems to all mineral processors around the world today. The problems are the inefficient collection of hydrophobic particles (low recovery), and mechanical/hydraulic entrainment of hydrophilic gangue particles (low concentrate grade). Extensive research has been conducted to improve the flotation recovery of fine hydrophobic particles. However, much less effort was made to lower the mechanical/hydraulic entrainment of fine gangue mineral particles. In this study, polyethylene oxide (PEO) was used to flocculate and depress fine quartz particles. Batch flotation results indicated that the addition of low dosages of PEO improved value mineral recovery and concentrate grade in the flotation of artificial mixtures of chalcopyrite/quartz and a commercial Au-Cu sulfide ore sample. It was found that PEO adsorbed on both minerals mainly through hydrogen bonding and caused non-selective flocculation of quartz and chalcopyrite, forming large hetero-aggregates. However, the addition of potassium amyl xanthate (KAX), a specific sulfide mineral collector, adsorbed on chalcopyrite through chemical interaction, replaced PEO and caused the chalcopyrite particles to break away from the hetero-aggregates, forming separate homo-aggregates of quartz and chalcopyrite. The flotation of the chalcopyrite and the depression of the quartz were thus both improved due to the larger sizes of the homo-aggregates compared to the discrete particles. It was also observed that a completely solubilized PEO solution could not flocculate quartz, while a partially solubilized PEO solution was most effective. This was attributed to the better “bridging” functions of the undissolved PEO aggregates when it was partially solubilized. When the PEO was fully solubilized, the individual PEO molecules were probably too flexible and tended to flatten on the adsorbed solid surface and thus could not function as an effective bridging flocculant. Furthermore, it was found that PEO could function as a “collector” for quartz due to its affinity to air-water interface and quartz, and it could increase quartz entrainment when used at high dosages. Selective flocculation and depression of the quartz gangue during chalcopyrite flotation could only be achieved at low PEO dosages. The implication of these observations on how to utilize the polyethylene oxide in industrial flotation was discussed.

Gong, Jihua

134

SUPASIM: a flotation plant design and analysis methodology  

Microsoft Academic Search

A methodology was developed in the mid-1980s to predict plant performance from standard laboratory flotation tests. The technique is based on a simple, empirical kinetics model, and is tailored for use by the practical metallurgist.To date the performance of more than 20 flotation plants has been predicted, encompassing copper, lead, zinc, nickel, phosphate, pyrite, graphite, cassiterite, platinum and various slags.

M. P. Hay; C. M. Rule

2003-01-01

135

An overview of Miocene reefs  

SciTech Connect

Miocene reefs lived approximately within the latitudes of 27{degree}S to 48{degree}N compared with 25{degree}S and 32{degree}N for Holocene reefs. This expansion of reef-growing environments was the result of warm Miocene climates, aided by a eustatic sea level rise and tectonic styles that provided numerous foundations for reef development. The majority of Miocene reefs are found in three main areas: (1) Southeast Asia and the western Pacific, (2) the Mediterranean-Middle East, and (3) Middle America and the Caribbean. These regions, with their distinctive suites of coral and foramineral species, formed three biological provinces; respectively, they are the Indo-Pacific, Tethyan, and Western Atlantic provinces. Miocene reefs in Southeast Asia occur in several foreland basins as patch reef complexes on paleohighs and as barrier reefs in back-arc basins. Those reefs in the Mediterranean occur as fringing reefs, middle-shelf patch reefs, or as barrier reefs on the edges of tectonic blocks associated with Alpine thrust belts. Most reefs in the Caribbean grew on isolated open-ocean highs of volcanic origin. Miocene reefs display a diversity of framework types: (1) coral-encrusting, red algal boundstones with diverse coral faunas, (2) branching coral-encrusting, red algal boundstones with a limited Poritid fauna, (3) encrusting red algal boundstones. Barrier reef systems are especially rich in encrusting red algae and robust corals; grainstones are common as interbedded sediment. Patch reef complexes, however, display muddy carbonate textures, may have less diverse coral faunas, and commonly have larger foraminifera. The global distribution of Miocene reefs is important because (1) it provides insight into a paleoclimatic view of the earth during a major greenhouse stage and (2) Miocene buildups, such as the Arun (EUR of 14 tcf) and Bima fields (EUR of about 100 MMBO), are exploration targets.

Jordan, C.F. Jr. (Mobil Research and Development Corp., Dallas, TX (USA)); Colgan, M.W. (College of Charleston, SC (USA)); Frost, S.H. (Unocal, Los Angeles, CA (USA)); Glenn, E.C. (Phillips Petroleum, Bartlesville, OK (USA)); Bosence, D. (Royal Holloway and Bedford New College, Egham (England)); Esteban, M. (ERICO Petroleum Information Ltd., London (England))

1990-05-01

136

Flotation process for purification of waste water  

SciTech Connect

In a flotation method for purification of industrial or municipal waste water, waste water comes in contact with electrodes having an electrical potential capable of electrolytically decomposing a portion of the waste water, thereby creating an ascending stream of gas bubbles. The waste water is mixed before or during the electrolytic decomposition with wettable particles of polymer material which are practically insoluble in water and have an absolute density of 1.3 g/cm3 at the most. Polymeric materials, especially polyalkane fibrids, are suitable for use as particles. This process makes it possible to purify oil-containing waste water by electroflotation without forming an oil film on the electrodes.

Julke, E.

1982-01-19

137

Reefs at risk.  

PubMed

Coral reefs, considered the rainforests of the seas, are home to a diverse number of marine species. These reefs are tightly woven ecosystems with complex linkages, which, if disturbed, result in an unpleasant chain of events. Furthermore, these reefs are the main source of animal protein for more than a billion people. Aside from supplying food, they stabilize shorelines and protect the land from rising seas and storm damage. Also, they provide sources of medicines used for bone grafts and treatment for certain viruses. However, these reefs are in danger of being permanently damaged as a result of natural and man-made forces. In response to this threat, most marine scientists have suggested that local communities be involved in the implementation and management of programs, with the aim of achieving sustainable reef maintenance. In addition, international agencies have taken the initiative to finance such programs to ensure their continuity. Overall, the management and development of coastal ecosystems depend on how they are managed and not on how they are being exploited. Resources must be rebuilt and their protection ensured for future generations. PMID:12322541

Hinrichsen, D

1999-01-01

138

Coral reef hydrogeology  

SciTech Connect

Knowledge of internal flow velocities and pore water residence time is important in understanding pore water geochemistry, nutrient fluxes at the benthic boundary, reef diagenesis, and fresh water resources in reef islands. Hydrogeologic studies of Pacific and Indian Ocean reef and atoll islands indicate a dual aquifer systems; the major Pleistocene aquifer has hydraulic conductivities on the order of 1000 m/d, while the overlying Holocene aquifer of unconsolidated sediments is at least an order of magnitude less permeable. The high permeability in the Pleistocene formation is the result of large voids, both constructional and from subaerial solution during low stands of the sea. Wind, wave and tide induced head differences ranging from a few centimeters to several tens of centimeters provide the driving force for internal flow. Pore water residence times and geochemistry will vary greatly, depending on whether the water is in a major flow channel or in more restricted pores. Studies of both submerged reefs and atoll islands give bulk pore water residence times on the order of months to a few years. Chemical analyses of pore water indicate that both carbonate solution and precipitation are taking place, which will alter porosity and permeability with time. The dual aquifer model also suggests that the Ghyben-Herzberg lens approach to reef island fresh water resources is inaccurate and can lead to a gross overestimation of the potable resource. 18 refs., 5 figs.

Buddemeier, R.W.; Oberdorfer, J.A.

1985-05-21

139

Evolution: Survival: Coral Reef Connections  

NSDL National Science Digital Library

The representation depicts the variety of organisms living near a coral reef and their relationships to one another. The interactive resource allows the user to move to different areas of the reef and select information about particular organisms, including relationships of "predation and parasitism," "competition," "commensalism and mutualism" at each reef zone.

140

The future of coral reefs  

Microsoft Academic Search

Coral reefs, with their millions of species, have changed profoundly because of the effects of people, and will continue to do so for the foreseeable future. Reefs are subject to many of the same processes that affect other human-dominated ecosystems, but some special features merit emphasis: (i) Many dominant reef builders spawn eggs and sperm into the water column, where

Nancy Knowlton

2001-01-01

141

ORE CONVEYANCE SYSTEM AND ADIT. LOOKING WEST. ORE FROM THE ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

ORE CONVEYANCE SYSTEM AND ADIT. LOOKING WEST. ORE FROM THE MINES ABOVE AT THE RIDGELINE AND TO THE RIGHT WAS CONVEYED TO THIS AREA AND DUMPED INTO THE SHAFT AT CENTER. THIS SHAFT OPENS INTO THE ADIT AT BOTTOM CENTER. THERE IS ANOTHER SHAFT OPENING INTO THE ADIT JUST ABOVE THE ADIT BEHIND THE STONE WALL. THE ORE WAS LOADED INTO TRAM CARS INSIDE THE ADIT AND CONVEYED ON TRACKS TO THE TRESTLE LEADING TO THE PRIMARY ORE BIN AT THE TRAM TERMINAL. TRACKS CAN BE SEEN LEADING FROM THE ADIT AND TO THE LEFT. THE ORE WAS THEN DUMPED INTO A CHUTE AT THE END OF THE TRESTLE CARRYING IT INTO THE ORE BIN AT THE TRAM TERMINAL(SEE CHUTE ON CA-291-30). - Keane Wonder Mine, Park Route 4 (Daylight Pass Cutoff), Death Valley Junction, Inyo County, CA

142

The effects of surfactant concentration on grease removal by air flotation in municipal sewage treatment  

E-print Network

in the flotation cell with time. Results obtained do not support the hypothesis of sur factant stabilization of grease. Rather, an increase in the response of grease to removal by dissolved air flotation with increasing sur- factant concentration is indicated... LAS Characterization of Standard Detergent ("Tide"). ~Pa e 17 19 22 23 Optimization of Air/Solids Ratio for Flotation. . 25 Summary of Flotation Test Results 30 Average Dissolved Air Flotation Rates, mg/1-min . 36 Average Unit Dissolved Air...

Perry, Larry Eugene

1978-01-01

143

Determination of flotation reagents used in tin-mining by capillary electrophoresis.  

PubMed

Alkyl xanthates (O-alkyl dithiocarbonates) and phosphonates are important organic collectors for the flotation of metals from crude ore. Leaching from waste dumps into river and ground water, these substances can cause environmental pollution. A capillary electrophoretic method for the routine determination of ethyl, isopropyl, hexyl xanthate, and styrene phosphonate has been developed. Separation within 12 min could be achieved in borate pH 8.8 performing UV detection at 254 and 300 nm simultaneously. To improve the limits of detection obtained with hydrodynamic injection (0.4-1.5 ppm), field amplified sample injection (FASI) and stacking were investigated. An increase in sensitivity up to 4-8 fold could be achieved by pressure assisted FASI. Applying a stacking method to enrich the analytes by filling the capillary with sample solution to one third of its length, the limits of detection could be decreased to 10-40 ppb. Water samples from a former tin ore mining area have been analyzed using the optimized stacking technique. Quantitation was performed by standard addition. Good precision and accuracy were obtained, making this robust capillary electrophoretic method well-suited for routine analysis. PMID:10486758

Hissner, F; Daus, B; Mattusch, J; Heinig, K

1999-08-20

144

Postglacial Fringing-Reef to Barrier-Reef conversion on Tahiti links Darwin's reef types  

PubMed Central

In 1842 Charles Darwin claimed that vertical growth on a subsiding foundation caused fringing reefs to transform into barrier reefs then atolls. Yet historically no transition between reef types has been discovered and they are widely considered to develop independently from antecedent foundations during glacio-eustatic sea-level rise. Here we reconstruct reef development from cores recovered by IODP Expedition 310 to Tahiti, and show that a fringing reef retreated upslope during postglacial sea-level rise and transformed into a barrier reef when it encountered a Pleistocene reef-flat platform. The reef became stranded on the platform edge, creating a lagoon that isolated it from coastal sediment and facilitated a switch to a faster-growing coral assemblage dominated by acroporids. The switch increased the reef's accretion rate, allowing it to keep pace with rising sea level, and transform into a barrier reef. This retreat mechanism not only links Darwin's reef types, but explains the re-occupation of reefs during Pleistocene glacio-eustacy. PMID:24845540

Blanchon, Paul; Granados-Corea, Marian; Abbey, Elizabeth; Braga, Juan C.; Braithwaite, Colin; Kennedy, David M.; Spencer, Tom; Webster, Jody M.; Woodroffe, Colin D.

2014-01-01

145

Postglacial fringing-reef to barrier-reef conversion on Tahiti links Darwin's reef types.  

PubMed

In 1842 Charles Darwin claimed that vertical growth on a subsiding foundation caused fringing reefs to transform into barrier reefs then atolls. Yet historically no transition between reef types has been discovered and they are widely considered to develop independently from antecedent foundations during glacio-eustatic sea-level rise. Here we reconstruct reef development from cores recovered by IODP Expedition 310 to Tahiti, and show that a fringing reef retreated upslope during postglacial sea-level rise and transformed into a barrier reef when it encountered a Pleistocene reef-flat platform. The reef became stranded on the platform edge, creating a lagoon that isolated it from coastal sediment and facilitated a switch to a faster-growing coral assemblage dominated by acroporids. The switch increased the reef's accretion rate, allowing it to keep pace with rising sea level, and transform into a barrier reef. This retreat mechanism not only links Darwin's reef types, but explains the re-occupation of reefs during Pleistocene glacio-eustacy. PMID:24845540

Blanchon, Paul; Granados-Corea, Marian; Abbey, Elizabeth; Braga, Juan C; Braithwaite, Colin; Kennedy, David M; Spencer, Tom; Webster, Jody M; Woodroffe, Colin D

2014-01-01

146

Postglacial Fringing-Reef to Barrier-Reef conversion on Tahiti links Darwin's reef types  

NASA Astrophysics Data System (ADS)

In 1842 Charles Darwin claimed that vertical growth on a subsiding foundation caused fringing reefs to transform into barrier reefs then atolls. Yet historically no transition between reef types has been discovered and they are widely considered to develop independently from antecedent foundations during glacio-eustatic sea-level rise. Here we reconstruct reef development from cores recovered by IODP Expedition 310 to Tahiti, and show that a fringing reef retreated upslope during postglacial sea-level rise and transformed into a barrier reef when it encountered a Pleistocene reef-flat platform. The reef became stranded on the platform edge, creating a lagoon that isolated it from coastal sediment and facilitated a switch to a faster-growing coral assemblage dominated by acroporids. The switch increased the reef's accretion rate, allowing it to keep pace with rising sea level, and transform into a barrier reef. This retreat mechanism not only links Darwin's reef types, but explains the re-occupation of reefs during Pleistocene glacio-eustacy.

Blanchon, Paul; Granados-Corea, Marian; Abbey, Elizabeth; Braga, Juan C.; Braithwaite, Colin; Kennedy, David M.; Spencer, Tom; Webster, Jody M.; Woodroffe, Colin D.

2014-05-01

147

Gray's Reef Research  

NSDL National Science Digital Library

Provides a sampling of research projects conducted at the Gray's Reef National Marine Sanctuary off Georgia's Sapelo Island. Projects range from geology to trawling impacts on the seafloor, estimating fish populations by video transect, Sanctuary monitoring using data buoys, sidescan sonar and other technologies. Examples of current projects: conducting a study on the movement patterns of fish in the area; efforts to understand the roles of "choices" fishes might make in their behaviors, and its impact on diversity of species found in reef fish communities and a study designed to inventory the invertebrates and fish communities and analyze how those communities are impacted by fishing activities. Appropriate for grades 9 and up.

148

SURFACTANT SPRAY: A NOVEL TECHNOLOGY TO IMPROVE FLOTATION DEINKING PERFORMANCE  

SciTech Connect

Based on the fundamental understanding of ink removal and fiber loss mechanism in flotation deinking process, we developed this innovative technology using surfactant spray to improve the ink removal efficiency, reduce the water and fiber loss, reduce the chemical consumption and carry over in the flotation deinking. The innovative flotation deinking process uses a spray to deliver the frothing agent during flotation deinking to control several key process variables. The spray can control the foam stability and structure and modify the fluid dynamics to reduce the fibers entrapped in the froth layer. The froth formed at the top part of the flotation column will act as a physical filter to prevent the penetration of frothing agent into the pulp suspension to eliminate fiber contamination and unfavorable deinking surface chemistry modification due to surfactant adsorption on the fiber surface. Because of the filter effect, frothing agents will be better utilized. Under the sponsorships of the US Dept. of Energy (DOE) and the member companies of the Institute of Paper Science and Technology, we studied the chem-mechanical mechanism of surfactant spray for flotation deinking using different furnishes, chemicals, and flotation devices in the past four years. In the final year of the project, we successfully conducted mill trials at Abitibi-Consolidated, Inc., Snowflake paper recycling operation of 100% mixture of ONP/OMG. Results from laboratory, pilot-plant and mill trials indicated that surfactant spray technology can significantly reduce fiber loss in flotation deinking. It can be concluded that paper industry can profit greatly when this technology is commercialized in flotation deinking mills.

Yulin Deng; Junyong Zhu

2004-01-31

149

Reef talus: A popular misconception  

NASA Astrophysics Data System (ADS)

Reef fronts have traditionally been regarded as comprising debris derived by contemporaneous erosion of 'the reef'. However, evidence from wave transport indicates that on present-day reefs the bulk of the debris generated in this way accumulates in the back-reef area, with only finer-grained sediment carried off-reef by retreating flows or by overwash. Nevertheless, in contrast to this observation, 'fore-reef' debris slopes are commonly considered "characteristic" of Phanerozoic reefs. This apparent error reflects the conflation of processes defining contemporary growth and accretion of the reef, and the corresponding long-term accretion of the carbonate platform on which it rests. Present-day reefs are commonly (although not exclusively) additions to long-lived carbonate platforms. Growth of the latter is intermittent and has been moderated by changes in sea-level that, for recent reefs, have been on time scales of less than 100 ka. During low sea-level stands, growth ceases or is translated downslope and earlier deposits are subject to lithification and subaerial erosion. Similar changes are applied on a larger scale to the aggrading growth of carbonate platforms, but the bulk accretion of these includes quite different processes and reflects far longer timescales. During low sea-level stands, the margins of platforms commonly become unstable, with instability reflected in slope failure and in the shedding of blocks, ranging from metres to kilometres in diameter, associated with the generation of debris flows and turbidites. It is argued that these are the materials that are commonly described as 'reef talus' in ancient structures, although their formation is largely independent of any contemporary reef growth. Difficulties arise where 'the reef' and 'the platform' are treated as a single functional entity. It is important to recognize the conceptual distinction between them, 'reef talus' is a misleading description of the debris predominantly generated by platform erosion and slope failure.

Braithwaite, Colin J. R.

2014-01-01

150

Sponge distribution across Davies Reef, Great Barrier Reef, relative to location, depth, and water movement  

Microsoft Academic Search

Sponge populations were surveyed at different depths in three zones of Davies Reef, a large platform reef of the central Great Barrier Reef. Depth is the major discriminatory factor as few sponges are found within the first 10 m depth and maximal populations occur between 15 m and 30 m on fore-reef, lagoon and back-reef slopes. Reef location is another

Clive R. Wilkinson; Elizabeth Evans

1989-01-01

151

MONITORING FRINGING CORAL REEFS FOR HUMAN IMPACTS  

Microsoft Academic Search

The Whitsunday Islands are the largest group of continental islands inside the Great Barrier Reef, with highly diverse fringing coral reefs. Their biology is still poorly understood. The reefs are heavily utilised by commercial tourism, yachts, fishermen and divers. Paradoxically, the desire to present the prettiest coral reefs to visiting divers focuses anchor damage onto the richest reefs. This chronic

James P. Thompson

1990-01-01

152

Capitol Reef's Castle  

USGS Multimedia Gallery

A view of the Castle, a prominent sandstone formation in Capitol Reef National Park. This area, known as the Fruita, is made up of three primary layers. The bottom sandstone layer is known as the Moenkopi Formation and is about 245 million years old. The middle gray-green layer is known as the Chinl...

153

Castle in Capitol Reef  

USGS Multimedia Gallery

A view of the Castle, a prominent sandstone formation in Capitol Reef National Park. This area, known as the Fruita, is made up of three primary layers. The bottom sandstone layer is known as the Moenkopi Formation and is about 245 million years old. The middle gray-green layer is known as the Chinl...

154

Capitol Reef Petroglyphs  

USGS Multimedia Gallery

From about 300-1300 CE, ancestors of the Hopi Tribe, Pueblo of Zuni, and Paiute Tribe lived in Capitol Reef. They are known by various names-archeologists call them the Fremont Culture; the Hopi Tribe calls them the Hisatsinom, or the

155

Petroglyphs in Captiol Reef  

USGS Multimedia Gallery

From about 300-1300 CE, ancestors of the Hopi Tribe, Pueblo of Zuni, and Paiute Tribe lived in Capitol Reef. They are known by various names-archeologists call them the Fremont Culture; the Hopi Tribe calls them the Hisatsinom, or the

156

14 CFR 121.340 - Emergency flotation means.  

Code of Federal Regulations, 2010 CFR

...TRANSPORTATION (CONTINUED) AIR CARRIERS AND OPERATORS FOR COMPENSATION OR HIRE: CERTIFICATION AND OPERATIONS OPERATING REQUIREMENTS...which the airplane is to be operated is not of such size and depth that life preservers or flotation means would be...

2010-01-01

157

21 CFR 890.5170 - Powered flotation therapy bed.  

Code of Federal Regulations, 2011 CFR

...powered flotation therapy bed is a device that is equipped with a mattress that contains a large volume of constantly moving water...treat severe or extensive burns, or to aid circulation. The mattress may be electrically heated. (b) Classification....

2011-04-01

158

21 CFR 890.5170 - Powered flotation therapy bed.  

Code of Federal Regulations, 2012 CFR

...powered flotation therapy bed is a device that is equipped with a mattress that contains a large volume of constantly moving water...treat severe or extensive burns, or to aid circulation. The mattress may be electrically heated. (b) Classification....

2012-04-01

159

21 CFR 890.5170 - Powered flotation therapy bed.  

Code of Federal Regulations, 2013 CFR

...powered flotation therapy bed is a device that is equipped with a mattress that contains a large volume of constantly moving water...treat severe or extensive burns, or to aid circulation. The mattress may be electrically heated. (b) Classification....

2013-04-01

160

21 CFR 890.5170 - Powered flotation therapy bed.  

Code of Federal Regulations, 2014 CFR

...powered flotation therapy bed is a device that is equipped with a mattress that contains a large volume of constantly moving water...treat severe or extensive burns, or to aid circulation. The mattress may be electrically heated. (b) Classification....

2014-04-01

161

21 CFR 890.5170 - Powered flotation therapy bed.  

Code of Federal Regulations, 2010 CFR

...powered flotation therapy bed is a device that is equipped with a mattress that contains a large volume of constantly moving water...treat severe or extensive burns, or to aid circulation. The mattress may be electrically heated. (b) Classification....

2010-04-01

162

FLOTATION ROOM, LOOKING SOUTHWEST, WITH LEAD ROUGHER CELLS AT RIGHT ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

FLOTATION ROOM, LOOKING SOUTHWEST, WITH LEAD ROUGHER CELLS AT RIGHT AND LEAD CLEANER CELLS AT LEFT. NOTE SUNNYSIDE GOLD CORP. "SG" LOGO ON ROUGHER CELL LAUNDER. - Shenandoah-Dives Mill, 135 County Road 2, Silverton, San Juan County, CO

163

Separation of algal cells from water by column flotation  

SciTech Connect

The dispersed air flotation (DiAF) process was utilized to separate algal cells (Chlorella sp.) from water. Two types of collector, cationic N-cetyl-N,N,N-trimethylammonium bromide (CTAB) and anionic sodium dodecylsulfate (SDS), were used. It was observed that 20% of cell removal was achieved in the presence of 40 mg/L of SDS, and ca. 86% of the cells were removed at 40 mg/L of CTAB. Upon the addition of 10 mg/L of chitosan, over 90% of the cells were removed when SDS (20 mg/L) was used as the collector. Air flow rate affected cell flotation slightly. Optimum pH values for cell flotation were from 4.0 to 5.0. Flotation efficiency decreased at high ionic strength. The electrostatic interaction between collector and cell surface plays a critical role in the separation processes.

Liu, J.C.; Chen, Y.M.; Ju, Y.H. [National Taiwan Univ. of Science and Technology, Taipei (Taiwan, Province of China). Dept. of Chemical Engineering] [National Taiwan Univ. of Science and Technology, Taipei (Taiwan, Province of China). Dept. of Chemical Engineering

1999-08-01

164

DISSOLVED AIR FLOTATION TREATMENT OF GULF SHRIMP CANNERY WASTEWATER  

EPA Science Inventory

This study reports on the operation of a plant scale dissolved air flotation system installed to define and evaluate attainable shrimp cannery wastewater treatment levels. The system was operated in all three modes of DAF pressurization. Destabilizing coagulants investigation inc...

165

Miocene reefs in western Mediterranean  

SciTech Connect

Coral reefs were particularly abundant and well developed during the late Tortonian and Messinian in southeastern Spain, the Balearic Islands, Italy, Sicily, Algeria, and Morocco. These reefs occurred just before and during the deposition of the thick Messinian evaporite units in the basinal areas and disappeared completely from Mediteranean during the early Pliocene. Most of the coral reefs are fringing terrigenous coastal fan complexes with very small lagoons and show progradation of less than 2 km. Some of the reefs occur on, or are intercalated with, Neogene volcanics or Messinian evaporites. Barrier-reef complexes are less common, have extensive lagoons behind them, and show complex progradational geometries more than 10 km wide. Excellent outcrops allow detailed reconstruction of paleogeography and sea level changes. Progradation predominated during phases of relative sea level drops and stillsands, while significant retrogradation occurred during sea level rises. The coral reef wall framework is commonly less than 20 m thick and is dominated by Porites and, locally, Tarbellastrae. Older Miocene reefs are less well developed, but show greater diversity of corals and reef organisms. Younger Miocene reef complexes occurring in open ocean settings are formed by only one branching coral genus (Porites or, locally, Tarbellastraea) with branching colonies up to 7 m high. Halimeda sands are particularly abundant in the upper reef slopes with occasional intercalations of red algae pavements that most likely coincide with episodes of terrigenous influx.

Esteban, M.

1988-01-01

166

Wetting film stability and flotation kinetics.  

PubMed

Single bubble experiments performed with different size fractions of quartz particles and different, but known, contact angles revealed two modes of flotation dynamics in superclean water. (1.) A monotonic increase of collection efficiency Ecoll with increasing particle size was observed at high particle hydrophobicity and, correspondingly, a low wetting film stability (WFS). (2.) At low particle hydrophobicity and, correspondingly, high WFS, an extreme dependence of Ecoll on particle size was observed. The use of superclean water in our experiments prevented the retardation of bubble surface movement caused by surfactants or other impurities that is usual for other investigations and where particle-bubble inertial hydrodynamic interactions are suppressed. In the present study the free movement of the bubble surface enhances particle-bubble inertial interaction, creating conditions for different flotation modes, dependent on WFS. At the instant of inertial impact, a particle deforms the bubble surface, which may cause its rebound. Where the stability of the thin water film, formed between opposing surfaces of a bubble and a particle, is low, its rupture is accompanied with three phase contact line extension and contact angle formation before rebound. This prevents rebound, i.e. the first collision is accompanied by attachment. A high WFS prevents rupture during an impact. As a result, a contact angle does not arise and rebound is not prevented. However, rebound is accompanied by a second collision, the kinetic energy of which is smaller and can cause attachment at repetitive collision. These qualitative considerations are confirmed by the model quantification and comparison with measured Ecoll. For the first time the Sutherland equation (SE) for Ecoll is confirmed by experiment for smaller particle sizes and, correspondingly, very small Stokes numbers. The larger the particle size, the larger is the measured deviation from the SE. The SE is generalized, accounting for the centrifugal force, pressing hydrodynamic force and drainage in the low WFS case and, correspondingly, attachment occurs at first collision or during sliding. The derived generalized Sutherland equation (GSE) describes experimental data at low WFS. However, its application without account for possible rebound does not explain the measured extreme dependence in the case of high WFS. The theory for drainage during particle impact and the beginning of rebound enables conditions for either attachment or rebound in terms of the normal component of the impact velocity and the critical film thickness to be derived. Combining this condition with the GSE allowed the equation for Ecoll to be derived, accounting for attachment area shrinkage and attachment during a repetitive collision. This equation predicts the extreme dependence. Thus the WFS determines the modes of flotation dynamics and, in turn, probably affects the mechanisms, which control the flotation domain. At low WFS its upper boundary is controlled by the stability of the particle-bubble aggregate. At high WFS the upper boundary can be controlled by rebound because the latter reduces the attachment efficiency by a factor of 30 or more even with repetitive collision. PMID:11843192

Ralston, J; Dukhin, S S; Mishchuk, N A

2002-02-12

167

Cross flow cyclonic flotation column for coal and minerals beneficiation  

DOEpatents

An apparatus and process for the separation of coal from pyritic impurities using a modified froth flotation system. The froth flotation column incorporates a helical track about the inner wall of the column in a region intermediate between the top and base of the column. A standard impeller located about the central axis of the column is used to generate a centrifugal force thereby increasing the separation efficiency of coal from the pyritic particles and hydrophillic tailings.

Lai, Ralph W. (Upper St. Clair, PA); Patton, Robert A. (Pittsburgh, PA)

2000-01-01

168

Cross flow flotation column for coal and minerals beneficiation  

SciTech Connect

An apparatus and process are disclosed for the separation of coal from pyritic impurities using a modified froth flotation system. The froth flotation column incorporates a helical track about the inner wall of the column in a region intermediate between the top and base of the column. A standard impeller located about the central axis of the column is used to generate a centrifugal force thereby increasing the separation efficiency of coal from the pyritic particles and hydrophilic tailings.

Lai, Ralph W.; Patton, Robert A.

1997-12-01

169

Uranium Ore Uranium is extracted  

E-print Network

Milling of Uranium Ore Uranium is extracted from ore with strong acids or bases. The uranium is concentrated in a solid substance called"yellowcake." Chemical Conversion Plants convert the uranium in yellowcake to uranium hexafluoride (UF6 ), a compound that can be made into nuclear fuel. Enrichment

170

Boiling treatment of ABS and PS plastics for flotation separation.  

PubMed

A new physical method, namely boiling treatment, was developed to aid flotation separation of acrylonitrile-butadiene-styrene (ABS) and polystyrene (PS) plastics. Boiling treatment was shown to be effective in producing a hydrophilic surface on ABS plastic. Fourier Transform Infrared analysis was conducted to investigate the mechanism of boiling treatment of ABS. Surface rearrangement of polymer may be responsible for surface change of boiling treated ABS, and the selective influence of boiling treatment on the floatability of boiling treated plastics may be attributed to the difference in the molecular mobility of polymer chains. The effects of flotation time, frother concentration and particle size on flotation behavior of simple plastic were investigated. Based on flotation behavior of simple plastic, flotation separation of boiling treatment ABS and PS with different particle sizes was achieved efficiently. The purity of ABS and PS was up to 99.78% and 95.80%, respectively; the recovery of ABS and PS was up to 95.81% and 99.82%, respectively. Boiling treatment promotes the industrial application of plastics flotation and facilitates plastic recycling. PMID:24602834

Wang, Chong-qing; Wang, Hui; Wu, Bao-xin; Liu, Qun

2014-07-01

171

An observational heat budget analysis of a coral reef, Heron Reef, Great Barrier Reef, Australia  

NASA Astrophysics Data System (ADS)

Measurements of the surface energy balance, the structure and evolution of the convective atmospheric reef layer (CARL), and local meteorology and hydrodynamics were made during June 2009 and February 2010 at Heron Reef, Australia, to establish the relative partitioning of heating within the water and atmosphere. Horizontal advection was shown to moderate temperature in the CARL and the water, having a cooling influence on the atmosphere, and providing an additional source or sink of energy to the water overlying the reef, depending on tide. The key driver of atmospheric heating was surface sensible heat flux, while heating of the reef water was primarily due to solar radiation, and thermal conduction and convection from the reef substrate. Heating and cooling processes were more defined during winter due to higher sensible and latent heat fluxes and strong diurnal evolution of the CARL. Sudden increases in water temperature were associated with inundation of warmer oceanic water during the flood tide, particularly in winter due to enhanced nocturnal cooling of water overlying the reef. Similarly, cooling of the water over the reef occurred during the ebb tide as heat was transported off the reef to the surrounding ocean. While these results are the first to shed light on the heat budget of a coral reef and overlying CARL, longer-term, systematic measurements of reef thermal budgets are needed under a range of meteorological and hydrodynamic conditions, and across various reef types to elucidate the influence on larger-scale oceanic and atmospheric processes. This is essential for understanding the role of coral reefs in tropical and sub-tropical meteorology; the physical processes that take place during coral bleaching events, and coral and algal community dynamics on coral reefs.

MacKellar, Mellissa C.; McGowan, Hamish A.; Phinn, Stuart R.

2013-03-01

172

USGS Pacific Coral Reefs Website  

NSDL National Science Digital Library

This gateway provides access to United States Geological Survey (USGS) studies of coral reefs in the Pacific Ocean, especially in the Hawaiian Islands where efforts are are focused on mapping, monitoring, remote sensing, sediment transport studies, and collection of tide, wave, and current data from remote stations. Materials include basic facts about coral reefs, an overview of the risks and threats to reefs, news items, and links to publications and other related organizations. Separate pages describe the individual projects, including mapping of the reefs, efforts to monitor changes on the reefs (the Coral Reef Assessment and Monitoring Program (CRAMP)), and studies of sedimentation and sediment transport. There is also an interactive map showing the locations of the study areas.

173

Oceanic forcing of coral reefs.  

PubMed

Although the oceans play a fundamental role in shaping the distribution and function of coral reefs worldwide, a modern understanding of the complex interactions between ocean and reef processes is still only emerging. These dynamics are especially challenging owing to both the broad range of spatial scales (less than a meter to hundreds of kilometers) and the complex physical and biological feedbacks involved. Here, we review recent advances in our understanding of these processes, ranging from the small-scale mechanics of flow around coral communities and their influence on nutrient exchange to larger, reef-scale patterns of wave- and tide-driven circulation and their effects on reef water quality and perceived rates of metabolism. We also examine regional-scale drivers of reefs such as coastal upwelling, internal waves, and extreme disturbances such as cyclones. Our goal is to show how a wide range of ocean-driven processes ultimately shape the growth and metabolism of coral reefs. PMID:25251270

Lowe, Ryan J; Falter, James L

2015-01-01

174

Optimization of Cu-Zn Massive Sulphide Flotation by Selective Reagents  

NASA Astrophysics Data System (ADS)

Selective floatation of base metal sulphide minerals can be achieved by using selective reagents. Sequential floatation of chalcopyrite-sphalerite from Taknar (Iran) massive sulphide ore with 3.5 % Zn and 1.26 % Cu was studied. D-optimal design of response surface methodology was used. Four mixed collector types (Aer238 + SIPX, Aero3477 + SIPX, TC1000 + SIPX and X231 + SIPX), two depressant systems (CuCN-ZnSO4 and dextrin-ZnSO4), pH and ZnSO4 dosage were considered as operational factors in the first stage of flotation. Different conditions of pH, CuSO4 dosage and SIPX dosage were studied for sphalerite flotation from first stage tailings. Aero238 + SIPX induced better selectivity for chalcopyrite against pyrite and sphalerite. Dextrin-ZnSO4 was as effective as CuCN-ZnSO4 in sphalerite-pyrite depression. Under optimum conditions, Cu recovery, Zn recovery and pyrite content in Cu concentrate were 88.99, 33.49 and 1.34 % by using Aero238 + SIPX as mixed collector, CuCN-ZnSO4 as depressant system, at ZnSO4 dosage of 200 g/t and pH 10.54. When CuCN was used at the first stage, CuSO4 consumption increased and Zn recovery decreased during the second stage. Maximum Zn recovery was 72.19 % by using 343.66 g/t of CuSO4, 22.22 g/t of SIPX and pH 9.99 at the second stage.

Soltani, F.; Koleini, S. M. J.; Abdollahy, M.

2014-10-01

175

Interfacial electrochemistry of pyrite oxidation and flotation. 1: Effect of borate on pyrite surface oxidation  

SciTech Connect

The interfacial chemistry of pyrite is of great industrial importance in complex sulfide ore flotation, coal desulfurization, acid mine drainage mitigation, and conversion of solar energy to electrical or chemical energy. Sodium tetraborate (Na{sub 2}B{sub 4}O{sub 7}) has been widely used as an electrolyte and pH buffer in studying the interfacial electrochemistry of sulfide minerals in relation to sulfide mineral flotation. In all the previous studies published so far, borate was regarded as an inert electrolyte/pH buffer, and its reactions with the sulfide minerals were completely overlooked. In this first part of this series papers, the complicating effects of borate on the interfacial electrochemistry of pyrite have been studied. In the borate solutions, the surface oxidation of pyrite is strongly enhanced. The first and rate-determining step of the reaction between borate and pyrite has been shown to be the following irreversible reaction: FeS{sub 2} + B(OH){sub 4}{sup {minus}} {yields} FeS{sub 2} {hor_ellipsis} [B(OH){sub 4}]{sub ads} + e. This reaction appears in the voltammogram as an anodic oxidation peak at potentials of more than 0.4 V lower than the commencement of pyrite oxidation in sodium perchlorate or nitrate electrolyte solutions. As the borate concentration increases, the peak current increases linearly, while the peak potential shifts positively at 240 mV per decade. On a rotating-disc electrode, the peak becomes a plateau. The limiting current density is a linear function of the square root of the rotation speed at relatively low rotation speeds. The Tafel slope is close to 240 mV per decade and is independent of the rotation speed and borate concentration. The results indicate that charge transfer coefficient is 0.25.

Wang, X.H. [Univ. of Kentucky, Lexington, KY (United States)] [Univ. of Kentucky, Lexington, KY (United States)

1996-03-25

176

The Paleoecology of Coral Reefs  

Microsoft Academic Search

\\u000a Reefs are one of the oldest ecosystems in the world, and coral reefs have had a rich and varied history over hundreds of millions\\u000a of years. The long-term history of living reef organisms provides an essential window in which to view a number of fundamental\\u000a evolutionary and ecological processes over extended time frames not available to modern ecology over years

John M. Pandolfi

177

Millenium Coral Reefs Landsat Archive  

NSDL National Science Digital Library

Users can access remote imagery of coral reefs by clicking on an interactive world map. The imagery consists of tiled mosaics which can be zoomed, panned, and downloaded. This archive of coral reef images is part of a project whose purpose is to develop global reef maps as a base for future research. It was created in a partnership with NASA, international agencies, universities and other organizations to provide natural resource managers a comprehensive world data resource on coral reefs and adjacent land areas.

178

Digital Reef Rugosity Estimates Coral Reef Habitat Complexity  

PubMed Central

Ecological habitats with greater structural complexity contain more species due to increased niche diversity. This is especially apparent on coral reefs where individual coral colonies aggregate to give a reef its morphology, species zonation, and three dimensionality. Structural complexity is classically measured with a reef rugosity index, which is the ratio of a straight line transect to the distance a flexible chain of equal length travels when draped over the reef substrate; yet, other techniques from visual categories to remote sensing have been used to characterize structural complexity at scales from microhabitats to reefscapes. Reef-scale methods either lack quantitative precision or are too time consuming to be routinely practical, while remotely sensed indices are mismatched to the finer scale morphology of coral colonies and reef habitats. In this communication a new digital technique, Digital Reef Rugosity (DRR) is described which utilizes a self-contained water level gauge enabling a diver to quickly and accurately characterize rugosity with non-invasive millimeter scale measurements of coral reef surface height at decimeter intervals along meter scale transects. The precise measurements require very little post-processing and are easily imported into a spreadsheet for statistical analyses and modeling. To assess its applicability we investigated the relationship between DRR and fish community structure at four coral reef sites on Menjangan Island off the northwest corner of Bali, Indonesia and one on mainland Bali to the west of Menjangan Island; our findings show a positive relationship between DRR and fish diversity. Since structural complexity drives key ecological processes on coral reefs, we consider that DRR may become a useful quantitative community-level descriptor to characterize reef complexity. PMID:23437380

Dustan, Phillip; Doherty, Orla; Pardede, Shinta

2013-01-01

179

Removal of Wax and Stickies from OCC by Flotation  

SciTech Connect

Laboratory research indicates that wax is amenable to removal by froth flotation provided it is free or detached from the fiber. The only effective means, at this time, of maximizing detachment of wax is through the use of low consistency pulping at temperatures above the melting point of wax. Wax removal from WCC through washing, flotation, or a combination of both was approximately 90% in these laboratory studies, indicating that not all of the wax is detached from fibers. These results were summarized in Annual Report 1, December 1, 1997 to November 30, 1998. Pilot trials were conducted in which the authors simulated a conventional OCC repulping process with and without flotation. Additional aggressive washing and water clarification were also examined during the study. The inclusion of flotation in the OCC stock preparation system significantly improved the removal of wax spots and extractable material from the furnish. Based on this study, the authors predict that a compact flotation system with 2 lb surfactant/ton of fiber would improve the OCC pulp quality with regard to wax spots by 60% and would not negatively affect strength properties. Flotation losses would be in the 2-5% range. Two mill trials were conducted during the last quarter of the project. One trial was carried out at Green Bay Packaging, Green Bay, WI, and a second trial was conducted at Menasha Corporation, Otsego, MI. A 250-liter Voith Sulzer Ecocell was used to evaluate the removal of wax and stickies from the OCC processing systems at these two mills. The inclusion of flotation in the OCC stock preparation system significantly improved the removal of wax spots from the furnish. The data indicate that flotation was more effective in removing wax and stickies than reverse cleaners. The mill trials have demonstrated that flotation can be substituted for or replace existing reverse cleaning systems and, in some cases, can replace dispersion systems. In this manner, the use of flotation can provide significant energy savings when compared to reverse cleaning or dispersion.

M. R. Doshi; J. Dyer

2000-01-31

180

Ordovician reef-hosted Jiaodingshan Mn-Co deposit and Dawashan Mn deposit, Sichuan Province, China  

USGS Publications Warehouse

The Jiaodingshan Mn-Co and Dawashan Mn deposits are located in the approximately 2-m thick Daduhe unit of the Wufengian strata of Late Ordovician (Ashgill) age. Paleogeographic reconstruction places the deposits at the time of their formation in a gulf between Chengdu submarine rise and the Kangdian continent. The Jiaodingshan and Dawashan deposits occur in algal-reef facies, the former in an atoll-like structure and the latter in a pinnacle reef. Ores are mainly composed of rhodochrosite, kutnahorite, hausmannite, braunite, manganosite, and bementite. Dark red, yellowish-pink, brown, green-gray, and black ores are massive, banded, laminated, spheroidal, and cryptalgal (oncolite, stromatolite, algal filaments) boundstones. Blue, green, and red algal fossils show in situ growth positions. Samples of high-grade Jiaodingshan and Dawashan ores assay as much as 66.7% MnO. Jiaodingshan Mn carbonate ores have mean contents of Ba, Co, and Pb somewhat higher than in Dawashan ores. Cobalt is widely distributed and strongly enriched in all rock types as compared to its crustal mean content. Cobalt is correlated with Cu, Ni, and MgO in both deposits and additionally with Ba and Zn in the Dawashan deposit. The ?13C(PDB) values of Mn carbonate ores (-7.8 to -16.3‰) indicate contributions of carbon from both seawater bicarbonate and the bacterial degradation of organic matter, the latter being 33% to 68%, assuming about -24‰ for the ?13C(PDB) of the organic matter. Host limestones derived carbon predominantly from seawater bicarbonate ?1313C(PDB) of +0.2 to -7‰). NW-trending fault zones controlled development of lithofacies, whereas NE-trending fault zones provided pathways for movement of fluids. The source of Co, Ni, and Cu was mainly from weathering of mafic and ultramafic rocks on the Kangdian continent, whereas contemporaneous volcanic eruptions were of secondary importance. The reefs were likely mineralized during early diagenesis under shallow burial. The reefs were highly porous and acted as the locus for metasomatic replacement by Mn that combined with CO2 produced during oxidation of organic matter in the zone of sulfate reduction and seawater bicarbonate. That metasomatic replacement formed the rhodochrosite ores.

Fan, Delian; Hein, James R.; Ye, Jie

1999-01-01

181

Coral reefs on the edge? Carbon chemistry on inshore reefs of the great barrier reef.  

PubMed

While increasing atmospheric carbon dioxide (CO2) concentration alters global water chemistry (Ocean Acidification; OA), the degree of changes vary on local and regional spatial scales. Inshore fringing coral reefs of the Great Barrier Reef (GBR) are subjected to a variety of local pressures, and some sites may already be marginal habitats for corals. The spatial and temporal variation in directly measured parameters: Total Alkalinity (TA) and dissolved inorganic carbon (DIC) concentration, and derived parameters: partial pressure of CO2 (pCO2); pH and aragonite saturation state (?ar) were measured at 14 inshore reefs over a two year period in the GBR region. Total Alkalinity varied between 2069 and 2364 µmol kg-1 and DIC concentrations ranged from 1846 to 2099 µmol kg-1. This resulted in pCO2 concentrations from 340 to 554 µatm, with higher values during the wet seasons and pCO2 on inshore reefs distinctly above atmospheric values. However, due to temperature effects, ?ar was not further reduced in the wet season. Aragonite saturation on inshore reefs was consistently lower and pCO2 higher than on GBR reefs further offshore. Thermodynamic effects contribute to this, and anthropogenic runoff may also contribute by altering productivity (P), respiration (R) and P/R ratios. Compared to surveys 18 and 30 years ago, pCO2 on GBR mid- and outer-shelf reefs has risen at the same rate as atmospheric values (?1.7 µatm yr-1) over 30 years. By contrast, values on inshore reefs have increased at 2.5 to 3 times higher rates. Thus, pCO2 levels on inshore reefs have disproportionately increased compared to atmospheric levels. Our study suggests that inshore GBR reefs are more vulnerable to OA and have less buffering capacity compared to offshore reefs. This may be caused by anthropogenically induced trophic changes in the water column and benthos of inshore reefs subjected to land runoff. PMID:25295864

Uthicke, Sven; Furnas, Miles; Lřnborg, Christian

2014-01-01

182

Coral Reefs on the Edge? Carbon Chemistry on Inshore Reefs of the Great Barrier Reef  

PubMed Central

While increasing atmospheric carbon dioxide (CO2) concentration alters global water chemistry (Ocean Acidification; OA), the degree of changes vary on local and regional spatial scales. Inshore fringing coral reefs of the Great Barrier Reef (GBR) are subjected to a variety of local pressures, and some sites may already be marginal habitats for corals. The spatial and temporal variation in directly measured parameters: Total Alkalinity (TA) and dissolved inorganic carbon (DIC) concentration, and derived parameters: partial pressure of CO2 (pCO2); pH and aragonite saturation state (?ar) were measured at 14 inshore reefs over a two year period in the GBR region. Total Alkalinity varied between 2069 and 2364 µmol kg?1 and DIC concentrations ranged from 1846 to 2099 µmol kg?1. This resulted in pCO2 concentrations from 340 to 554 µatm, with higher values during the wet seasons and pCO2 on inshore reefs distinctly above atmospheric values. However, due to temperature effects, ?ar was not further reduced in the wet season. Aragonite saturation on inshore reefs was consistently lower and pCO2 higher than on GBR reefs further offshore. Thermodynamic effects contribute to this, and anthropogenic runoff may also contribute by altering productivity (P), respiration (R) and P/R ratios. Compared to surveys 18 and 30 years ago, pCO2 on GBR mid- and outer-shelf reefs has risen at the same rate as atmospheric values (?1.7 µatm yr?1) over 30 years. By contrast, values on inshore reefs have increased at 2.5 to 3 times higher rates. Thus, pCO2 levels on inshore reefs have disproportionately increased compared to atmospheric levels. Our study suggests that inshore GBR reefs are more vulnerable to OA and have less buffering capacity compared to offshore reefs. This may be caused by anthropogenically induced trophic changes in the water column and benthos of inshore reefs subjected to land runoff. PMID:25295864

Uthicke, Sven; Furnas, Miles; Lřnborg, Christian

2014-01-01

183

46 CFR 117.72 - Personal flotation devices carried in addition to life jackets.  

Code of Federal Regulations, 2013 CFR

... Personal flotation devices carried in addition to life jackets. 117.72 Section 117.72 Shipping...PASSENGERS LIFESAVING EQUIPMENT AND ARRANGEMENTS Ring Life Buoys and Life Jackets § 117.72 Personal flotation devices...

2013-10-01

184

46 CFR 117.72 - Personal flotation devices carried in addition to life jackets.  

Code of Federal Regulations, 2011 CFR

... Personal flotation devices carried in addition to life jackets. 117.72 Section 117.72 Shipping...PASSENGERS LIFESAVING EQUIPMENT AND ARRANGEMENTS Ring Life Buoys and Life Jackets § 117.72 Personal flotation devices...

2011-10-01

185

46 CFR 180.72 - Personal flotation devices carried in addition to life jackets.  

Code of Federal Regulations, 2013 CFR

... Personal flotation devices carried in addition to life jackets. 180.72 Section 180.72 Shipping...TONS) LIFESAVING EQUIPMENT AND ARRANGEMENTS Ring Life Buoys and Life Jackets § 180.72 Personal flotation devices...

2013-10-01

186

46 CFR 117.72 - Personal flotation devices carried in addition to life jackets.  

Code of Federal Regulations, 2012 CFR

... Personal flotation devices carried in addition to life jackets. 117.72 Section 117.72 Shipping...PASSENGERS LIFESAVING EQUIPMENT AND ARRANGEMENTS Ring Life Buoys and Life Jackets § 117.72 Personal flotation devices...

2012-10-01

187

46 CFR 117.72 - Personal flotation devices carried in addition to life jackets.  

Code of Federal Regulations, 2010 CFR

... Personal flotation devices carried in addition to life jackets. 117.72 Section 117.72 Shipping...PASSENGERS LIFESAVING EQUIPMENT AND ARRANGEMENTS Ring Life Buoys and Life Jackets § 117.72 Personal flotation devices...

2010-10-01

188

46 CFR 180.72 - Personal flotation devices carried in addition to life jackets.  

Code of Federal Regulations, 2012 CFR

... Personal flotation devices carried in addition to life jackets. 180.72 Section 180.72 Shipping...TONS) LIFESAVING EQUIPMENT AND ARRANGEMENTS Ring Life Buoys and Life Jackets § 180.72 Personal flotation devices...

2012-10-01

189

46 CFR 180.72 - Personal flotation devices carried in addition to life jackets.  

Code of Federal Regulations, 2014 CFR

... Personal flotation devices carried in addition to life jackets. 180.72 Section 180.72 Shipping...TONS) LIFESAVING EQUIPMENT AND ARRANGEMENTS Ring Life Buoys and Life Jackets § 180.72 Personal flotation devices...

2014-10-01

190

46 CFR 117.72 - Personal flotation devices carried in addition to life jackets.  

Code of Federal Regulations, 2014 CFR

... Personal flotation devices carried in addition to life jackets. 117.72 Section 117.72 Shipping...PASSENGERS LIFESAVING EQUIPMENT AND ARRANGEMENTS Ring Life Buoys and Life Jackets § 117.72 Personal flotation devices...

2014-10-01

191

46 CFR 180.72 - Personal flotation devices carried in addition to life jackets.  

Code of Federal Regulations, 2010 CFR

... Personal flotation devices carried in addition to life jackets. 180.72 Section 180.72 Shipping...TONS) LIFESAVING EQUIPMENT AND ARRANGEMENTS Ring Life Buoys and Life Jackets § 180.72 Personal flotation devices...

2010-10-01

192

46 CFR 180.72 - Personal flotation devices carried in addition to life jackets.  

Code of Federal Regulations, 2011 CFR

... Personal flotation devices carried in addition to life jackets. 180.72 Section 180.72 Shipping...TONS) LIFESAVING EQUIPMENT AND ARRANGEMENTS Ring Life Buoys and Life Jackets § 180.72 Personal flotation devices...

2011-10-01

193

33 CFR 183.235 - Level flotation test without weights for persons capacity.  

Code of Federal Regulations, 2012 CFR

...BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Flotation Requirements for Outboard Boats Rated for Engines of More Than 2 Horsepower Tests § 183.235 Level flotation test without weights for persons capacity. When the conditions prescribed...

2012-07-01

194

33 CFR 183.335 - Level flotation test without weights for persons capacity.  

Code of Federal Regulations, 2014 CFR

...CONTINUED) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Flotation Requirements for Outboard Boats Rated for Engines of 2 Horsepower or Less Tests § 183.335 Level flotation test without weights for persons capacity. When the conditions...

2014-07-01

195

33 CFR 183.335 - Level flotation test without weights for persons capacity.  

Code of Federal Regulations, 2013 CFR

...CONTINUED) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Flotation Requirements for Outboard Boats Rated for Engines of 2 Horsepower or Less Tests § 183.335 Level flotation test without weights for persons capacity. When the conditions...

2013-07-01

196

33 CFR 183.335 - Level flotation test without weights for persons capacity.  

Code of Federal Regulations, 2011 CFR

...CONTINUED) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Flotation Requirements for Outboard Boats Rated for Engines of 2 Horsepower or Less Tests § 183.335 Level flotation test without weights for persons capacity. When the conditions...

2011-07-01

197

33 CFR 183.335 - Level flotation test without weights for persons capacity.  

Code of Federal Regulations, 2012 CFR

...CONTINUED) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Flotation Requirements for Outboard Boats Rated for Engines of 2 Horsepower or Less Tests § 183.335 Level flotation test without weights for persons capacity. When the conditions...

2012-07-01

198

33 CFR 183.235 - Level flotation test without weights for persons capacity.  

Code of Federal Regulations, 2013 CFR

...BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Flotation Requirements for Outboard Boats Rated for Engines of More Than 2 Horsepower Tests § 183.235 Level flotation test without weights for persons capacity. When the conditions prescribed...

2013-07-01

199

33 CFR 183.235 - Level flotation test without weights for persons capacity.  

Code of Federal Regulations, 2014 CFR

...BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Flotation Requirements for Outboard Boats Rated for Engines of More Than 2 Horsepower Tests § 183.235 Level flotation test without weights for persons capacity. When the conditions prescribed...

2014-07-01

200

33 CFR 183.235 - Level flotation test without weights for persons capacity.  

Code of Federal Regulations, 2011 CFR

...BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Flotation Requirements for Outboard Boats Rated for Engines of More Than 2 Horsepower Tests § 183.235 Level flotation test without weights for persons capacity. When the conditions prescribed...

2011-07-01

201

Treatment of washrack wastewater with water recycling by advanced flocculation–column flotation  

Microsoft Academic Search

A new technique for flocculation and flotation (aerated flocs), called flocculation–column flotation (FCF) was evaluated for the treatment of vehicle (bus) washrack wastewater and water reuse. The system is composed of a compact flocculation–flotation unit, utilizing an in-line flocculator device, a centrifugal multiphase pump which generates microbubbles (Sauter mean diameter, 75 ?m), and a column flotation for solid\\/liquid separation. Design

Jorge Rubio; Rafael Newton Zaneti

2009-01-01

202

Coral reefs and carbon dioxide  

SciTech Connect

This commentary argues the conclusion from a previous article, which investigates diurnal changes in carbon dioxide partial pressure and community metabolism on coral reefs, that coral `reefs might serve as a sink, not a source, for atmospheric carbon dioxide.` Commentaries from two groups are given along with the response by the original authors, Kayanne et al. 27 refs.

Buddemeier, R.W. [Kansas Geological Survey, Lawrence, KS (United States)

1996-03-01

203

Sandstone Cliff in Capitol Reef  

USGS Multimedia Gallery

A sandstone cliff in Capitol Reef National Park. Capitol Reef is primarily made up of sandstone formations within the Waterpocket Fold, monocline that extends nearly 100 miles. A monocline is a step-like fold in rock strata that can resemble an enormous wrinkle in the earth....

204

Sandstone Cliffs in Capitol Reef  

USGS Multimedia Gallery

Sandstone cliffs in Capitol Reef National Park. Capitol Reef is primarily made up of sandstone formations within the Waterpocket Fold, monocline that extends nearly 100 miles. A monocline is a step-like fold in rock strata that can resemble an enormous wrinkle in the earth....

205

Sandstone Monolith in Capitol Reef  

USGS Multimedia Gallery

A sandstone monolith in Capitol Reef National Park. Capitol Reef is primarily made up of sandstone formations within the Waterpocket Fold, monocline that extends nearly 100 miles. A monocline is a step-like fold in rock strata that can resemble an enormous wrinkle in the earth....

206

Coral Reef Recovery from Hurricane Damage and Implications of Coral Reefs for Future Medical Discoveries  

Microsoft Academic Search

Recent experimentation has found soft corals and sponges to have potential medical uses in treating cancer and other diseases. Research was conducted via underwater transect data collection using SCUBA on several coral reefs in Cozumel, Mexico, approximately three years after hurricane Wilma destroyed much of the reef. Three 100 m linear transects of fore reef, hind reef and reef crest

Katelyn Mescher; Ashley Sturgess

2009-01-01

207

Nanoparticle flotation collectors II: the role of nanoparticle hydrophobicity.  

PubMed

The ability of polystyrene nanoparticles to facilitate the froth flotation of glass beads was correlated to the hydrophobicity of the nanoparticles. Contact angle measurements were used to probe the hydrophobicity of hydrophilic glass surfaces decorated with hydrophobic nanoparticles. Both sessile water drop advancing angles, ?(a), and attached air bubble receding angle measurements, ?(r), were performed. For glass surfaces saturated with adsorbed nanoparticles, flotation recovery, a measure of flotation efficiency, increased with increasing values of each type of contact angle. As expected, the advancing water contact angle on nanoparticle-decorated, dry glass surfaces increased with surface coverage, the area fraction of glass covered with nanoparticles. However, the nanoparticles were far more effective at raising the contact angle than the Cassie-Baxter prediction, suggesting that with higher nanoparticle coverages the water did not completely wet the glass surfaces between the nanoparticles. A series of polystyrene nanoparticles was prepared to cover a range of surface energies. Water contact angle measurements, ?(np), on smooth polymer films formed from organic solutions of dissolved nanoparticles were used to rank the nanoparticles in terms of hydrophobicity. Glass spheres were saturated with adsorbed nanoparticles and were isolated by flotation. The minimum nanoparticle water contact angle to give high flotation recovery was in the range of 51° < ?(np(min)) ? 85°. PMID:21830818

Yang, Songtao; Pelton, Robert

2011-09-20

208

Microbial biotransformation of kimberlite ores.  

E-print Network

??Microbial leaching plays a significant role in the natural weathering of silicate containing ores such as diamond-bearing kimberlite. Harnessing microbial leaching processes to pre-treat mined… (more)

Ramcharan, Karishma.

2008-01-01

209

Microbial reduction of iron ore  

DOEpatents

A process is provided for reducing iron ore by treatment with microorganisms which comprises forming an aqueous mixture of iron ore, microorganisms operable for reducing the ferric iron of the iron ore to ferrous iron, and a substrate operable as an energy source for the microbial reduction; and maintaining the aqueous mixture for a period of time and under conditions operable to effect the reduction of the ore. Preferably the microorganism is Pseudomonas sp. 200 and the reduction conducted anaerobically with a domestic wastewater as the substrate. An aqueous solution containing soluble ferrous iron can be separated from the reacted mixture, treated with a base to precipitate ferrous hydroxide which can then be recovered as a concentrated slurry. 11 figs.

Hoffmann, M.R.; Arnold, R.G.; Stephanopoulos, G.

1989-11-14

210

Microbial reduction of iron ore  

DOEpatents

A process is provided for reducing iron ore by treatment with microorganisms which comprises forming an aqueous mixture of iron ore, microorganisms operable for reducing the ferric iron of the iron ore to ferrous iron, and a substrate operable as an energy source for the microbial reduction; and maintaining the aqueous mixture for a period of time and under conditions operable to effect the reduction of the ore. Preferably the microorganism is Pseudomonas sp. 200 and the reduction conducted anaerobically with a domestic wastewater as the substrate. An aqueous solution containing soluble ferrous iron can be separated from the reacted mixture, treated with a base to precipitate ferrous hydroxide which can then be recovered as a concentrated slurry.

Hoffmann, Michael R. (Pasadena, CA); Arnold, Robert G. (Pasadena, CA); Stephanopoulos, Gregory (Pasadena, CA)

1989-01-01

211

Use of RO and NF for treatment of copper containing wastewaters in combination with flotation  

Microsoft Academic Search

The process of so-called membrane flotation can be used in combination with NF\\/RO techniques for treatment of wastewaters containing copper and other heavy metals to decrease the environmental risks. Microporous inorganic membranes are used in membrane flotation process as diffusers for air sparging. Various ways of combination of flotation and membrane filtration in cationic wastewater treatment practice are discussed. With

P. S. Sudilovskiy; G. G. Kagramanov; V. A. Kolesnikov

2008-01-01

212

Functional versatility supports coral reef biodiversity  

E-print Network

Functional versatility supports coral reef biodiversity D. R. Bellwood1,*, P. C. Wainwright2 , C. J. Fulton1 and A. S. Hoey1 1 Department of Marine Biology, Centre for Coral Reef Biodiversity, James Cook of high biodiversity on coral reefs. Keywords: coral reef fishes; specialist; generalist; functional

Wainwright, Peter C.

213

PBS Online NewsHour: Coral Reefs  

NSDL National Science Digital Library

In-depth coverage of the role of coral reefs in environment, medicinal properties, and conservation efforts, together with instructional materials. Includes lesson plan; interactive on coral-reef building blocks; extended interviews; and stories on reef threats, international treaties, Caribbean reefs, mangrove shields, and the Aquarius undersea lab. Main story is provided as text, streaming video, and RealAudio.

214

The Changing Health of Coral Reefs  

Microsoft Academic Search

Throughout their entire global range coral reefs are in decline. Coral bleaching, macroalgal overgrowth and coral diseases — responses signaling the declining health of coral reefs — have occurred with increasing frequency and intensity in recent decades. Decreased calcification may also be affecting coral reefs over longer time scales. Declines in coral reef health have been attributed to various natural

Richard T. Barber; Anna K. Hilting; Marshall L. Hayes

2001-01-01

215

Coral reef protection  

NASA Astrophysics Data System (ADS)

The National Oceanic and Atmospheric Administration announced the establishment on 13 November of the first U.S. zone to protect a sensitive coral reef area from potential damage by ships.The Florida Keys' Particularly Sensitive Sea Area, just one of a handful of such areas globally, has been designated by the International Maritime Organization, a specialized agency of the United Nations. The area protects a zone of more than 3,000 square nautical miles stretching from the Biscayne National Park to the Dry Tortugas.

Showstack, Randy

216

Capitol Reef National Park  

NSDL National Science Digital Library

This National Park Service (NPS) website provides an in-depth look at Capitol Reef National Park in Utah. Specifically, this covers the geology and natural resources of the park. There is a general overview of the geology of this area including the Waterpocket fold, Colorado Plateau, Cathedral Valley and erosion. There is a description of various rock colors and how they form, as well as a detailed stratigraphic column illustrating the names, thicknesses, and ancient environments of rocks and formations that exist in the park. The Natural Resources section discusses some of the history and archeology of the park, as well as birds, mammals, plants, reptiles and environmental problems.

217

Ore distribution in the Herminia mine (Julcani, Peru): ore bands and role ore shoots  

SciTech Connect

Julcani has been one of the major silver and bismuth producing districts of Peru during the past 30 years. The veins are related to a late Miocene volcanic complex and the ore minerals are mainly enargite, tetrahedrite, various silver sulfosalts and galena; gangue minerals are mostly pyrite and barite. Extensive mining, good accessibility and excellent record keeping provide a good opportunity to study ore distribution patterns and zoning in the Herminia mine. Six veins were selected because of their abundant information and coverage of the zoning sequence. The inner copper, intermediate silver and outer lead grade maxima are shown to form parallel ore bands that are generally concordant with the previously reported metal ratio contours, despite the different ages of the ore minerals. These systematic relations are corroborated by logarithmic covariation diagrams. Ore bands join at vein junctions, demonstrating that the vein network constituted a connected hydrothermal system. Oreshoots form at ore band lobes that are related to greater vein widths. Grade and ratio contours indicate that solution flow was generally horizontal to the SW within a favorable volcanic horizon in the 420-580 level range. Several exploration and development applications are illustrated.

Petersen, U.; Murdock, G.

1985-01-01

218

Adaptive Avoidance of Reef Noise  

PubMed Central

Auditory information is widely used throughout the animal kingdom in both terrestrial and aquatic environments. Some marine species are dependent on reefs for adult survival and reproduction, and are known to use reef noise to guide orientation towards suitable habitat. Many others that forage in food-rich inshore waters would, however, benefit from avoiding the high density of predators resident on reefs, but nothing is known about whether acoustic cues are used in this context. By analysing a sample of nearly 700,000 crustaceans, caught during experimental playbacks in light traps in the Great Barrier Reef lagoon, we demonstrate an auditory capability in a broad suite of previously neglected taxa, and provide the first evidence in any marine organisms that reef noise can act as a deterrent. In contrast to the larvae of species that require reef habitat for future success, which showed an attraction to broadcasted reef noise, taxa with a pelagic or nocturnally emergent lifestyle actively avoided it. Our results suggest that a far greater range of invertebrate taxa than previously thought can respond to acoustic cues, emphasising yet further the potential negative impact of globally increasing levels of underwater anthropogenic noise. PMID:21326604

Simpson, Stephen D.; Radford, Andrew N.; Tickle, Edward J.; Meekan, Mark G.; Jeffs, Andrew G.

2011-01-01

219

A Study of the Optimal Model of the Flotation Kinetics of Copper Slag from Copper Mine BOR  

NASA Astrophysics Data System (ADS)

In this study the effect of mixtures of copper slag and flotation tailings from copper mine Bor, Serbia on the flotation results of copper recovery and flotation kinetics parameters in a batch flotation cell has been investigated. By simultaneous adding old flotation tailings in the ball mill at the rate of 9%, it is possible to increase copper recovery for about 20%. These results are compared with obtained copper recovery of pure copper slag. The results of batch flotation test were fitted by MatLab software for modeling the first-order flotation kinetics in order to determine kinetics parameters and define an optimal model of the flotation kinetics. Six kinetic models are tested on the batch flotation copper recovery against flotation time. All models showed good correlation, however the modified Kelsall model provided the best fit.

Stanojlovi?, Rodoljub D.; Sokolovi?, Jovica M.

2014-10-01

220

NOAA's hydrolab conducts reef studies  

NASA Astrophysics Data System (ADS)

This summer, scuba-diving scientists operating from Hydrolab, NOAA's undersea laboratory, are carrying out four experiments aimed at producing better management of coral reefs and their fishery resources. Hydrolab is located at a depth of 50 feet, near the mouth of the Salt River, off St. Croix, U.S. Virgin Islands. The lab houses four scientists for up to 2 weeks at a time, permitting them to swim out into the water to conduct research. The projects make use of both the natural coral reef near Hydrolab and the nearby artificial reef constructed for comparison studies.

221

Hydrocarbon-oil encapsulated bubble flotation of fine coal using 3-in. ID flotation column. Technical progress report for the eleventh quarter, April 1--June 30, 1993  

SciTech Connect

There are four modes of the collector dispersion techniques. They are (1) direct liquid additions and stirring, (2) ultrasonic energy collector dispersion, (3) atomized collector dispersion, and (4) gasified collector transported in air stream. Among those collector dispersion techniques, the technique using the gasified collector transported in air phase can be used to enhance the flotation performance with substantial reduction in collector usage and selectivity, compared to the flotation using direct liquid addition (and mechanical agitation) technique. In this phase of study, two modes of collector addition techniques including gasified collector transported in gas phase and direct collector addition techniques were applied in the column flotation to demonstrate the selectivity of utilizing the hydrocarbon-oil encapsulated air bubbles in the fine coal flotation process. The 1-in. ID flotation column was used to scale-up to 3-in. ID flotation column. The initial starting point to operate the 3-in ID flotation column were determined using both 1-in. and 3-in. flotation columns based on the three phases of work plans and experiment design. A 3-in. flotation column was used to evaluate two modes of collector dispersion and addition techniques on the recovery and grade of fine coals using various ranks of coal.

Peng, F.F.

1996-05-01

222

Home Reef, South Pacific  

NASA Technical Reports Server (NTRS)

In the South Pacific, south of Late Island along the Tofua volcanic arc in Tonga, a new volcanic island Home Reef is being re-born. The island is thought to have emerged after a volcanic eruption in mid-August that has also spewed large amounts of floating pumice into Tongan waters and sweeping across to Fiji about 350 km (220 miles) to the west of where the new island has formed. In 2004 a similar eruption created an ephemeral island about 0.5 by 1.5 km (0.3 by 0.9 miles) in size; it was no longer visible in an ASTER image acquired November 2005. This simulated natural color image shows the vegetation-covered stratovolcanic island of Late in the upper right. Home Reef is found in the lower left. The two bluish plumes are hot seawater that is laden with volcanic ash and chemicals; the larger one can be traced for more than 14 km (8.4 miles) to the east. The image was acquired October 10, 2006 and covers an area of 24.3 by 30.2 km. It is located at 18.9 degrees South latitude, 174.7 degrees west longitude.

With its 14 spectral bands from the visible to the thermal infrared wavelength region, and its high spatial resolution of 15 to 90 meters (about 50 to 300 feet), ASTER images Earth to map and monitor the changing surface of our planet.

ASTER is one of five Earth-observing instruments launched December 18, 1999, on NASA's Terra satellite. The instrument was built by Japan's Ministry of Economy, Trade and Industry. A joint U.S./Japan science team is responsible for validation and calibration of the instrument and the data products.

The broad spectral coverage and high spectral resolution of ASTER provides scientists in numerous disciplines with critical information for surface mapping, and monitoring of dynamic conditions and temporal change. Example applications are: monitoring glacial advances and retreats; monitoring potentially active volcanoes; identifying crop stress; determining cloud morphology and physical properties; wetlands evaluation; thermal pollution monitoring; coral reef degradation; surface temperature mapping of soils and geology; and measuring surface heat balance.

The U.S. science team is located at NASA's Jet Propulsion Laboratory, Pasadena, Calif. The Terra mission is part of NASA's Science Mission Directorate.

Size: 24.3 by 30.2 kilometers (15 by 18.6 miles) Location: 18.9 degrees South latitude, 174.7 degrees West longitude Orientation: North at top Image Data: ASTER bands 3, 2, and 1 Original Data Resolution: 15 meters (49.2 feet) Dates Acquired: October 4, 2006

2006-01-01

223

The modes of occurrence of rare-earths ores and the issues on their beneficiation processes  

NASA Astrophysics Data System (ADS)

Rare-earths (RE) ores can largely be divided into the following four types in terms of the modes of occurrence. In each type of RE ores, there are some issues on beneficiation processes, which should be resolved for their successful exploitation. 1. Fine-grained phosphates with iron oxides: This type ores are commonly found from weathered carbonatite and IOCG deposits. The former is Araxa (Brazil), Zandkopsdrift (South Africa), Mt. Weld (Australia) and Yen Phu (Vietnam), and the latter Bayan Obo (China), Vergenoeg (South Africa) and Olympic Dam (Australia). Main RE minerals are monazite, xenotime and florencite contained in the aggregates of iron oxides such as goethite, hematite and magnetite. Fluorite often occurs in the latter type ores. The phosphates and iron oxides occur commonly as very fine grains (< 10 micron meters), and thus they are not readily separated by conventional physical processing. 2. Fluorapatite veins: This type ores are found from the deposits related to alkaline igneous rocks. Nolans Bore (Australia), Palabora (South Africa) and Mushugai Khudag (Mongolia) are the examples. RE is contained mostly in fluorapatite and associated monazite. It is expected that RE can be produced as byproducts of phosphorus fertilizer. However, dissolution of fluorapatite by sulfuric acid causes the coprecipitation of RE with gypsum, which is a refractory material. 3. Silicates and niobium oxides: This type ores are found from hydrothermally altered alkaline plutonic rocks or pegmatitic veins related to alkaline magmatism. Nechalacho and Strange Lake (Canada), Kvanefjeld (Greenland), Bokan Mountain (US), Norra Karr (Sweden) and Dubbo (Australia) are the representative deposits. Main RE minerals are zircon, eudialyte, mosandrite, fergusonite and allanite. They are relatively enriched in heavy RE, and it is expected that part of RE can be produced as byproducts of zirconium. However, their acid dissolution often causes the coprecipitation of RE with silica gel, which is also a refractory material. 4. Medium- to coarse-grained carbonates: This type ores occur in less weathered carbonatite bodies. Mountain Pass (US), Maoniuping (China) and Dong Pao (Vietnam) are the representative deposits. Bastnasite is a main RE mineral. Though, the ores can readily be beneficiated by conventional flotation and dissolved by acid solution, they are always depleted in heavy RE.

Takagi, T.

2012-04-01

224

Sandstone Formations in Capitol Reef  

USGS Multimedia Gallery

Capitol Reef is primarily made up of sandstone formations within the Waterpocket Fold, monocline that extends nearly 100 miles. A monocline is a step-like fold in rock strata that can resemble an enormous wrinkle in the earth....

225

Overview of flotation as a wastewater treatment technique  

Microsoft Academic Search

The treatment of aqueous or oily effluents is one of the most serious environmental issues faced by the minerals and metallurgy industries. Main pollutants are residual reagents, powders, chemicals, metal ions, oils, organic and some may be valuable (Au, Pt, Ag). The use of flotation is showing a great potential due to the high throughput of modern equipment, low sludge

J Rubio; M. L Souza; R. W Smith

2002-01-01

226

Surface chemistry control for selective fossil resin flotation  

DOEpatents

A froth flotation method is disclosed for separating fine particles of fossil resin from by use of frothing reagents which include an aliphatic organic compound having a polar group and containing not more than four carbon atoms. Butanol is an effective frothing reagent in this method.

Miller, Jan D. (1886 Atkin Ave., Salt Lake City, UT 84106); Yi, Ye (2875 E. Wander Way, Salt Lake City, UT 84117); Yu, Qiang (224 University Village, Salt Lake City, UT 84108)

1994-01-01

227

Surface chemistry control for selective fossil resin flotation  

DOEpatents

A froth flotation method is disclosed for separating fine particles of fossil resin by use of frothing reagents which include an aliphatic organic compound having a polar group and containing not more than four carbon atoms. Butanol is an effective frothing reagent in this method. 12 figs.

Miller, J.D.; Yi, Y.; Yu, Q.

1994-06-07

228

Engineering development of advanced froth flotation. Volume 2, Final report  

SciTech Connect

This report is an account of findings related to the Engineering and Development of Advanced Froth Flotation project. The results from benchscale and proof-of-concept (POC) level testing are presented and the important results from this testing are used to refine a conceptual design and cost estimate for a 20 TPH Semi-Works Facility incorporating the final proposed technology.

Ferris, D.D.; Bencho, J.R.; Torak, E.R. [ICF Kaiser Engineers, Inc., Pittsburgh, PA (United States)

1995-03-01

229

Alternative Flotation Techniques for Wastewater Treatment: Focus on Electroflotation  

Microsoft Academic Search

During the last decades (dissolved-air) flotation has found several applications in water and wastewater treatment. Flocculation is generally required in advance for a satisfactory separation and a membrane process is often applied downstream. Examples from the literature given in the present review include heavy metals, textile dyes, food, paper industry, oily effluents, laundry wastewaters, sludge etc. and are accompanied by

K. A. Matis; E. N. Peleka

2010-01-01

230

Innovations in the design of super-large flotation cells  

SciTech Connect

A new super-large 100 m{sup 3} (3,500 ft{sup 3}) pneumatic mechanical flotation cell is now available to meet today`s mineral processing challenges. Several innovative design concepts represent a marked departure from conventional flotation cell designs. The radial discharge from the pump action rotor and the overhung vane type stator is contained in a conical bottom round tank with no dead corners. Peripheral launders collect froth overflowing the entire circumference of the tank and these launders are of a hexagonal design permitting cells to be nested together in a honeycomb fashion. The mechanism drive is either a customized right angle gear reducer or a conventional Vee belt drive. Both drive systems are available with an optional variable frequency control system that permits infinite speed adjustment of the rotor in each flotation cell or group of cells. Results of side-by-side comparative testing between three major manufacturers of super-large pneumatic mechanical flotation cells are discussed. These results were obtained at a large copper concentrator in Chile during several weeks of commercial scale testing.

Lawrence, G.A. [Dorr-Oliver, Inc., Denver, CO (United States)

1995-12-31

231

Coal surface control for advanced fine coal flotation  

SciTech Connect

The primary objective of this research project is to develop advanced flotation methods for coal cleaning in order to achieve near total pyritic-sulfur removal at 90% Btu recovery, using coal samples procured from six major US coal seams. Concomitantly, the ash content of these coals is to be reduced to 6% or less. Work this quarter concentrated on the following: washability studies, which included particle size distribution of the washability samples, and chemical analysis of washability test samples; characterization studies of induction time measurements, correlation between yield, combustible-material recovery (CMR), and heating-value recovery (HVR), and QA/QC for standard flotation tests and coal analyses; surface modification and control including testing of surface-modifying reagents, restoration of hydrophobicity to lab-oxidized coals, pH effects on coal flotation, and depression of pyritic sulfur in which pyrite depression with calcium cyanide and pyrite depression with xanthated reagents was investigated; flotation optimization and circuitry included staged reagent addition, cleaning and scavenging, and scavenging and middling recycling. Weathering studies are also discussed. 19 figs., 28 tabs.

Fuerstenau, D.W.; Sastry, K.V.S.; Hanson, J.S.; Harris, G.; Sotillo, F.; Diao, J. (California Univ., Berkeley, CA (USA)); Somasundaran, P.; Harris, C.C.; Vasudevan, T.; Liu, D.; Li, C. (Columbia Univ., New York, NY (USA)); Hu, Weibai; Zou, Y.; Chen, W. (Utah Univ., Salt Lake City, UT (USA)); Choudhry, V.; Sehgal, R.; Ghosh, A. (Praxis Engineers, Inc., Milpitas, CA (USA))

1990-08-15

232

Lateral Deflections of Webs in Air-Flotation Ovens  

E-print Network

­ lateral tilt angle of air-bar, in radians ­ spring constant of air cushion supporting web over bar ­ webLateral Deflections of Webs in Air-Flotation Ovens Peter M. Moretti March 2, 2001 Abstract A long web span supported by many, regularly spaced, alternating air- bars is studied. The focus

233

Preparation of clean coal by flotation following ultra fine liberation  

Microsoft Academic Search

This paper reports the results of current fundamental research at the Department of Process Engineering, University of Miskolc on the processing of clean coal from Mecsek bituminous coal, Southern Hungary. The theoretical possibility of the separation of different petrographic components was proven experimentally and their liberation degree was determined based on the petrographic composition, flotation kinetic study of isolated components

Ljudmilla Bokányi; Barnabás Csöke

2003-01-01

234

Florida Keys NMS: Coral Reefs  

NSDL National Science Digital Library

Florida Keys National Marine Sanctuary's page with information on coral reefs and links to information on research, restoration and monitoring. Wealth of information on the protection of Florida's coral reefs and the Florida Keys as a whole. Includes an in-class activity for grades K-5, as well as information on a Keys field experience and teacher workshops. Information on safe diving and snorkeling. Education materials available for purchase, including the Seagrass Toolbox.

235

Yoon–Luttrell collision and attachment models analysis in flotation and their application on general flotation kinetic model  

Microsoft Academic Search

We theoretically used the models of Yoon and Luttrell for collision and attachment efficiencies to show the effect of fluid flow condition, the effect of bubble size and velocity and particle surface hydrophobicity in flotation system, and in order to demonstrate the effect of particle density on the attachment behavior we incorporate the correct expression for the maximum collision angle

S. Kouachi; M. Bouhenguel; A. Amirech; A. Bouchemma

2010-01-01

236

ORE POLYNOMIALS IN SAGE MANUEL KAUERS  

E-print Network

ORE POLYNOMIALS IN SAGE MANUEL KAUERS , MAXIMILIAN JAROSCHEK , FREDRIK JOHANSSON Abstract. We present a Sage implementation of Ore algebras. The main features for the most common instances include an implementation of a collection of algorithms related to Ore algebras for the computer algebra system Sage [14

Schneider, Carsten

237

Ancient reef ecosystem expansion and collapse  

NASA Astrophysics Data System (ADS)

Platform carbonate and, particularly, reef ecosystem development (with reefs representing the acme of carbonate platform growth) were highly cyclical in early to mid Paleozoic time, especially in relation to known or postulated times of global warming or cooling. These cycles do not appear to correspond to postulated 26 Ma rhythms seen in diversity patterns, nor were they regular. There were major periods of worldwide reef expansion (e.g. mid-Silurian-Late Devonian), corresponding to global warming well above present day norms, and periods of complete global reef collapse (e.g., mid-Cambrian to mid-Ordovician, Late Devonian) corresponding to global perturbations. At times of major reef expansion in the Paleozoic, areas covered by equatorial reef and inter-reef carbonate platforms are conservatively estimated to have periodically exceeded 5 million sq. km, nearly ten times that in the modern ocean. At times of global reef collapse, e.g. the Famennian (Late Devonian), reef complexes were completely absent or, at best, covered <1000 sq. km. The chief factors relating to periodic collapse and mass extinction of reef biotas appear to be related to climatic change and possibly ocean anoxic events, in turn as a response to large scale, geologically disruptive factors such as plate collisions, plate movement across equatorial belts and volcanism. Stress “signals” in Cambrian through Cretaceous reef ecosystems appear to be comparable to those of today: whether these relate to physical versus biological stress is uncertain. Reef stress is evident in globally reduced areas and thicknesses of reef carbonate production, the absence of large scale barrier reef systems and reduction to smaller patch reef complexes (or, periodically, following mass extinctions, no reefs at all), reduced species and genus diversity, small skeletons or colonies, limited or no biotic zonation along reef transects, and arrested succession and ecologic replacement of complex, more highly evolved taxa by “simpler”, stress-resistant disaster taxa at the genus to ordinal (or even phylum) level.

Copper, P.

1994-01-01

238

Distribution, abundance, and substrate preferences of demersal reef zooplankton at Lizard Island Lagoon, Great Barrier Reef  

Microsoft Academic Search

Demersal zooplankton, those plankton which hide within reef sediments during the day but emerge to swim freely over the reef at night, were sampled quantitatively using emergence traps planced over the substrate at Lizard Island Lagoon, Great Barrier Reef. Densities of zooplankton emerging at night from 6 substrate types (fine, medium, and coarse sand, rubble, living coral and reef rock)

A. L. Alldredge; J. M. King

1977-01-01

239

CoralReefs(1995)14:91-97 CoralReefs9 Springer-Verlag1995 ~  

E-print Network

CoralReefs(1995)14:91-97 CoralReefs9 Springer-Verlag1995 ~ Taphonomy of crown-of-thorns starfish; and two theme issues of Coral Reefs in vols 9 (1990) and 11 Correspondenceto:B.J. Greentein (1992 sedimentologicanaly- sis of reef sediments provides conclusive evidence that the two damaging outbreaks in the last 35

Greenstein, Benjamin J.

240

112 National Coral Reef Action Strategy CORAL REEF CONSERVATION ACT OF 2000  

E-print Network

Reef Action Strategy APPENDIX A CORAL REEF CONSERVATION ACT OF 2000 [P.L. 106-562; 16 U.S.C. 6401 et seq; December 23, 2000] TITLE II--CORAL REEF CONSERVATION SEC. 201. SHORT TITLE. This title may be cited as the `Coral Reef Conservation Act of 2000'. SEC. 202. PURPOSES. The purposes of this title are

241

ORIGINAL ARTICLE Black reefs: iron-induced phase shifts on coral reefs  

E-print Network

ORIGINAL ARTICLE Black reefs: iron-induced phase shifts on coral reefs This article has been, Australia The Line Islands are calcium carbonate coral reef platforms located in iron-poor regions surveys show that the live coral cover was reduced from 40 to 60% to o10% on black reefs on Millennium

Smith, Jennifer E.

242

Coral reef crisis in deep and shallow reefs: 30 years of constancy and change in reefs of Curacao and Bonaire  

Microsoft Academic Search

Coral reefs are thought to be in worldwide decline but available data are practically limited to reefs shallower than 25 m.\\u000a Zooxanthellate coral communities in deep reefs (30–40 m) are relatively unstudied. Our question is: what is happening in deep\\u000a reefs in terms of coral cover and coral mortality? We compare changes in species composition, coral mortality, and coral cover\\u000a at Caribbean

Rolf P. M. Bak; Gerard Nieuwland; Erik H. Meesters

2005-01-01

243

Gomatriaux / Geomaterials (Mtallognie / Ore deposits)  

E-print Network

Géomatériaux / Geomaterials (Métallogénie / Ore deposits) Modalités de formation des veines de (Venezuela) gold-bearing quartz veins mode of formation: textural and fluid inclusion studies. Gold / �ditions scientifiques et médicales Elsevier SAS gold / quartz veins / texture / fluid inclusions

Paris-Sud XI, Université de

244

Gaseous reduction of laterite ores  

NASA Astrophysics Data System (ADS)

Lateritic nickel ores have been reduced under laboratory conditions. The reduction experiments were carried out at temperatures from 500 °C to 1100 °C in a horizontal tube furnace using various mixtures of H2 and CO2. The hydrogen evolution method was used to measure the degree of metallization of the reduced ore. It was found that the rate of reduction was very low at 500 °C but then increased rapidly upon heating the ore to 600 °C. The percent metallics increased with increasing H2 to CO2 ratios in the reducing gas. At temperatures between 600 °C and 1100 °C, a H2 to CO2 ratio of 3 leads to the formation of 5 to 6 pct metallics in the reduced calcine was shown. Heating the ore in air or nitrogen prior to reduction does not affect the degree of metallization. A H2 to CO2 ratio of at least 4 is required to obtain a ferronickel product analyzing 36 pct nickel if no further reduction is carried out during the subsequent smelting operation.

Utigard, T.; Bergman, R. A.

1993-04-01

245

Conical O-ring seal  

DOEpatents

A shipping container for radioactive or other hazardous materials which has a conical-shaped closure containing grooves in the conical surface thereof and an O-ring seal incorporated in each of such grooves. The closure and seal provide a much stronger, tighter and compact containment than with a conventional flanged joint.

Chalfant, Jr., Gordon G. (North Augusta, SC)

1984-01-01

246

Ocean acidification worse in coral reefs  

NASA Astrophysics Data System (ADS)

The rate of ocean acidification in coral reefs outpaces the rise in carbon dioxide (CO2) in Earth's atmosphere, indicating that anthropogenic carbon emissions alone are not to blame for the threat to coral reefs, a new study shows.

Betz, Eric O.

2014-12-01

247

Call to protect all coral reefs  

NASA Astrophysics Data System (ADS)

The world's coral reefs are in decline, threatening the food security of millions of people. Adopting an ecosystem-scale approach that protects deep as well as shallow reefs would deliver several social and economic benefits.

Bridge, Tom C. L.; Hughes, Terry P.; Guinotte, John M.; Bongaerts, Pim

2013-06-01

248

Long Wave Breaking Effects on Fringing Reefs  

E-print Network

Modeling of wave energy transformation and breaking on fringing reefs is inherently difficult due to the unique topography of reefs. Prior methods of determining dissipation are based on empirical data from gently sloping beaches and offer only bulk...

Goertz, John 1985-

2012-12-12

249

The dynamics of benthic microbial communities at Davies Reef, central Great Barrier Reef  

Microsoft Academic Search

The dynamics of benthic microbial communities were examined within different functional zones (reef crest, reef flat, lagoon) of Davies Reef, central Great Barrier Reef, in winter. Bacterial numbers did not change significantly across the reef with a mean abundance \\u000a$$(\\\\bar x{\\\\text{ }} \\\\pm {\\\\text{ 1 SE)}}$$\\u000a of 1.3 (±0.6) x 109 cells g-1 DW of sediment. Bacterial production, measured as

L. A. Hansen; D. M. Alongi; D. J. W. Moriarty; P. C. Pollard

1987-01-01

250

Trapping and dispersion of coral eggs around Bowden Reef, Great Barrier Reef, following mass coral spawning  

Microsoft Academic Search

Bowden Reef is a 5 km long kidney-shaped coral reef with a lagoon, located on the mid-shelf of the central region of the Great Barrier Reef. Field studies were carried out, in November 1986, at the time of mass coral spawning, of the water circulation around Bowden Reef and in the surrounding inter-reefal waters. The near-reef water circulation was strongly

Eric Wolanski; Derek Burrage; Brian King

1989-01-01

251

Coral communities and reef growth in the southern Great Barrier Reef  

Microsoft Academic Search

.  ?Fringing reef development is limited around 22°?S along the inner Great Barrier Reef, although there is substantial development\\u000a north and south of this latitude. This study examined the relationships among coral communities and the extent of reef development.\\u000a Reefs were examined to determine coral composition, colony abundance, colony size and growth form between the latitudes 20°S\\u000a and 23°S. Major reef

R. van Woesik; T. J. Done

1997-01-01

252

Wave Processes on Coral Reef Flats: Implications for Reef Geomorphology Using Australian Case Studies  

Microsoft Academic Search

KENCH, P.S., and BRANDER, R.W., 2006. Wave processes on coral reef flats: implications for reef geomorphology using Australian case studies. Journal of Coastal Research, 22(1), 209-223. West Palm Beach (Florida), ISSN 0749- 0208. Australian reef flats on the Cocos (Keeling) Islands atoll, Indian Ocean; Warraber Reef, Torres Strait; and Lady Elliot Island, Great Barrier Reef vary greatly in morphology (width,

Paul S. Kench; Robert W. Brander

2006-01-01

253

Coral Reef Conservation: A Reef of Your Own  

NSDL National Science Digital Library

This web-based lesson focuses on the physiological, ecological, and behavioral strategies that contribute to the success of reef-building corals. Students will learn to describe and explain the importance of asexual and sexual reproductive strategies to reef-building corals, why it is important that the corals have a nutritional strategy that includes both photosynthesis and carnivory, two behaviors that they use to compete for living space with other species, and how coral reefs can produce high levels of biological material when the waters surround­ing them contain relatively small amounts of the nutri­ents normally needed to support biological production. Links to the required online resources are provided.

2011-08-23

254

Recovery of proteins and microorganisms from cultivation media by foam flotation.  

PubMed

Foaming is often present in aerated bioreactors. It is undesired, because it removes the cells and the cultivation medium from the reactor and blocks the sterile filter. However, it can be used for the recovery of proteins and microorganisms from the cultivation medium. The present review deals with the characterization of model protein foams and foams of various cultivation media. The suppression of foaming by antifoam agents and their effect on the oxygen transfer rate, microbial cell growth and product formation are discussed. The influence of process variables on the recovery of proteins by flotation without and with surfactants and mathematical models for protein flotation are presented. The effect of cultivation conditions, flotation equipment and operational parameters on foam flotation of microorganisms is reviewed. Floatable and non-floatable microorganisms are characterized by their surface envelope properties. A mathematical model for cell recovery by flotation is presented. Possible application areas of cell recovery by flotation are discussed. PMID:11036688

Schügerl, K

2000-01-01

255

Virtual phosphorus ore requirement of Japanese economy.  

PubMed

Phosphorus is indispensable for agricultural production. Hence, the consumption of imported food indirectly implies the import of phosphorus resources. The global consumption of agricultural products depends on a small number of ore-producing countries. For sustainable management of phosphorus resources, the global supply and demand network should be clarified. In this study, we propose the virtual phosphorus ore requirement as a new indicator of the direct and indirect phosphorus requirements for our society. The virtual phosphorus ore requirement indicates the direct and indirect demands for phosphorus ore transformed into agricultural products and fertilizer. In this study, the virtual phosphorus ore requirement was evaluated for the Japanese economy in 2005. Importantly, the results show that our society requires twice as much phosphorus ore as the domestic demand for fertilizer production. The phosphorus contained in "eaten" agricultural products was only 12% of virtual phosphorus ore requirement. PMID:21636108

Matsubae, Kazuyo; Kajiyama, Jun; Hiraki, Takehito; Nagasaka, Tetsuya

2011-08-01

256

Miocene reefs of Dominican Republic  

SciTech Connect

The reefs are overlain by conglomeratic strata. The stratigraphic setting of these reefs suggests that they have developed along the stalled portions of rapidly prograding fan deltas. Thickets and layers of coral debris are found seaward and stratigraphically above the well-developed reef. The matrix sediments are exclusively fine-grained sand to mud, and the fauna are suggestive of more open shelf conditions. In thickets, branched (porites spp., Pocillopora spp.), small massive (Montastrea spp., Siderastrea spp.), and foliose or plate like (Agaricia spp.) corals are found upright in the muddy sediment. Similarities in coral species and areal proximity suggest that thickets are the source of most layers of coralline debris. The association of coral debris with graded bedding and cross-bedding suggests that coral debris has been reworked by storms. The growth of corals and development of coral reefs in the Miocene-Pliocene Yaque Group is limited only by opportunities created by the slowing of siliciclastic sedimentation. Soft, muddy, terrigenous substrates and a continuing supply of terrigenous mud exert only a limited, indirect effect on reef growth.

Evans, C.C.

1988-01-01

257

Coal waste artificial reef program. Phase I  

Microsoft Academic Search

The overall objective of the Coal Waste Artificial Reef Program is to explore the feasibility of a method for ocean disposal of fly ash and scrubber sludge from coal-fired power plants. The program is to construct an artificial reef in the Atlantic Ocean near Long Island from stabilized blocks of these waste materials. The reef is expected to enhance biological

P. M. J. Woodhead; I. W. Duedall; N. F. Lansing

1979-01-01

258

Coral Reefs and Their Management in Tanzania  

Microsoft Academic Search

Coral reefs are very important in Tanzania, both ecologically and socio-economically, as major fishing grounds and tourist attractions. Numerous fringing and patch reefs are located along about two-thirds of Tanzania's coastline. These reefs have been partially to severely degraded by human (primarily destructive fishing practices) and natural (particularly coral bleaching) causes. These immediate human causes have been brought about by

Greg M. Wagner

259

Experimental biology of coral reef ecosystems  

Microsoft Academic Search

Coral reef ecosystems are at the crossroads. While significant gaps still exist in our understanding of how “normal” reefs work, unprecedented changes in coral reef systems have forced the research community to change its focus from basic research to understand how one of the most diverse ecosystems in the world works to basic research with strong applied implications to alleviate

Michael P. Lesser

2004-01-01

260

Assessing Coral Reef Condition: Eliciting Community Meanings  

Microsoft Academic Search

Photographs depicting a gradient of coral reef condition associated with anchor damage were assessed and described by 76 research participants. The participants were divided into two groups: those with and those without occupational experience of coral reefs. Three important meanings ascribed to coral reefs were elicited. The most important meaning was “evaluation,” whether the scenes were perceived positively or negatively.

Elizabeth A. Dinsdale; D. Mark Fenton

2006-01-01

261

The future of coral reefs Nancy Knowlton*  

E-print Network

Colloquium The future of coral reefs Nancy Knowlton* Marine Biology Research Division 0202, Scripps Tropical Research Institute, Apartado 2072, Balboa, Republic of Panama Coral reefs, with their millions communities, and coral death. (iv) The activities of people near reefs increase both fishing pressure

Bermingham, Eldredge

262

Coal-pyrite flotation: a modified technique using concentrated second-stage pulp. Technical progress report  

Microsoft Academic Search

The Bureau of Mines two-stage coal-pyrite flotation process was modified to provide a more concentrated final clean coal slurry underflow that could be dewatered economically by filtration or centrifugation. This was accomplished by doing the first-stage coal flotation step in the conventional manner with a slurry of about 8 percent solids but running the second-stage pyrite flotation step with undiluted

1975-01-01

263

Coal-pyrite flotation: A modified technique using concentrated second stage pulp  

Microsoft Academic Search

The Bureau of Mines two-stage coal-pyrite flotation process was modified to provide a more concentrated final clean coal slurry underflow that could be dewatered economically by filtration or centrifugation. This was accomplished by doing the first-stage coal flotation step in the conventional manner with a slurry of about 8 percent solids but running the second-stage pyrite flotation step with undiluted

K. J. Miller

1975-01-01

264

Application of Odor Sensors to Ore Sorting and Mill Feed Control  

SciTech Connect

Control of the feed provided to mineral processing facilities is a continuing challenge. Much effort is currently being devoted to overcoming these problems. These projects are usually described under the general headings of Mine-to-Mill Integration or Mine-Mill Optimization. It should be possible to combine the knowledge of ore type, mineralogy, and other characteristics (located in the mine modeling system), with the advanced capabilities of state-of-the-art mill control systems, to achieve an improved level of control in mineral processing that will allow optimization of the mill processes on an almost real-time basis. This is not happening because mill feed it is often treated as a uniform material, when in reality it varies in composition and characteristics. An investigation was conducted to assess the suitability of odor sensors for maintaining traceability in ore production and processing. Commercially available sensors are now used in food processing, environmental monitoring, and other applications and can detect the presence of very small amounts (0.1-500 ppm) of some molecules. An assortment of such molecules could be used to ''tag'' blocks of ore as they are mined, according to their respective characteristics. Then, as the ore came into the mill, an array of ''electronic noses'' could be used to assess its characteristics in real time. It was found that the Cyranose 320{trademark}, a commercially available odor sensor, can easily distinguish among samples of rock marked with almond, cinnamon, citronella, lemon, and orange oils. Further, the sensor could detect mixtures of rocks marked with various combinations of these oils. Treatment of mixtures of galena and silica with odorant compounds showed no detrimental effects on flotation response in laboratory tests. Additional work is recommended to determine how this concept can be extended to the marking of large volumes of materials.

Michael G. Nelson

2005-08-01

265

Microalgae harvesting by flotation using natural saponin and chitosan.  

PubMed

This study aims to investigate the harvesting of microalgae by dispersed air flotation (DiAF) using natural biosurfactant saponin as the collector and chitosan as the flocculant. Two types of microalgae, Chlorella vulgaris and Scenedesmus obliquus, were used in this study. It was observed that saponin was a good frother, but not an effective collector when used alone for flotation separation of algae. However, with the pre-flocculation of 5 mg/L of chitosan, separation efficiency of >93% microalgae cells was found at 20 mg/L of saponin. Removal efficiency of >54.4% and >73.0% was found for polysaccharide and protein, respectively at 20 mg/L of saponin and chitosan each. Experimental results show that DiAF using saponin and chitosan is effective for separation of microalgae, and algogenic organic matter (AOM). It can potentially be applied in the integrated microalgae-based biorefinery. PMID:24935003

Kurniawati, H Agnes; Ismadji, Suryadi; Liu, J C

2014-08-01

266

Coral reef crisis in deep and shallow reefs: 30 years of constancy and change in reefs of Curacao and Bonaire  

NASA Astrophysics Data System (ADS)

Coral reefs are thought to be in worldwide decline but available data are practically limited to reefs shallower than 25 m. Zooxanthellate coral communities in deep reefs (30-40 m) are relatively unstudied. Our question is: what is happening in deep reefs in terms of coral cover and coral mortality? We compare changes in species composition, coral mortality, and coral cover at Caribbean (Curacao and Bonaire) deep (30-40 m) and shallow reefs (10-20 m) using long-term (1973-2002) data from permanent photo quadrats. About 20 zooxanthellate coral species are common in the deep-reef communities, dominated by Agaricia sp., with coral cover up to 60%. In contrast with shallow reefs, there is no decrease in coral cover or number of coral colonies in deep reefs over the last 30 years. In deep reefs, non-agaricid species are decreasing but agaricid domination will be interrupted by natural catastrophic mortality such as deep coral bleaching and storms. Temperature is a vastly fluctuating variable in the deep-reef environment with extremely low temperatures possibly related to deep-reef bleaching.

Bak, Rolf P. M.; Nieuwland, Gerard; Meesters, Erik H.

2005-11-01

267

Determination of tungsten and tin ions after preconcentration by flotation  

Microsoft Academic Search

A highly sensitive and selective combined method of flotation followed by spectrophotometry\\/d.c. polarography for the determination of tungsten and tin ions in acid and alkaline waste waters and hydrometallurgical solutions is presented here. Both kinds of ions are coprecipitated in the analyte solution with zirconium hydroxide after addition of ZrOCl2 solution and ammonia. Afterwards, the collector precipitate is separated from

Ulrich Dietze; Steffi Kunze

1990-01-01

268

Surface chemistry and flotation of cassiterite with alkyl hydroxamates  

Microsoft Academic Search

Surface chemistry and flotation of cassiterite in the presence of alkyl hydroxamic acid\\/salt surfactant has been investigated. Results of the adsorption isotherms, electrokinetic and infrared spectroscopy indicate that octyl hydroxamate adsorbs on cassiterite by both physical and specific forces. Adsorption of the surfactant was high in the acidic pH range indicating the involvement of octyl hydroxamic acid molecule (pKa?9) and

T. Sreenivas; N. P. H. Padmanabhan

2002-01-01

269

Adsorbing Flotation of Copper Hydroxo Precipitates by Pyrite Fines  

Microsoft Academic Search

The removal of copper ions from dilute aqueous solutions by the addition of mineral (pyrite) fine particles was undertaken by following an adsorbing (scavenging) flotation mechanism. Pyrite generally constitutes a residual or a solid industrial waste by-product in mixed sulfides processing plants. This paper suggests a further utilization for pyrite. The dissolved-air method was applied for solid\\/liquid separation when the

A. I. Zouboulis; K. A. Kydros; K. A. Matis

1992-01-01

270

Coal surface control for advanced fine coal flotation  

SciTech Connect

The primary objective in the scope of this research project is to develop advanced flotation methods for coal cleaning in order to achieve near total pyritic-sulfur removal at 90% Btu recovery, using coal samples procured from three major US coal seams. Concomitantly, the ash content of these coals is to be reduced to 6% or less. Investigation of mechanisms for the control of coal and pyrite surfaces prior to fine coal flotation is the main aspect of the project objectives. The results of this research are to be made available to ICF Kaiser Engineers who are currently working on the Engineering Development of Advanced Flotation under a separate contract with DOE under the Acid Rain Control Initiative program. A second major objective is to investigate factors involved in the progressive weathering and oxidation of coal that had been exposed to varying degrees of weathering, namely, open to the atmosphere, covered and in an argon-inerted'' atmosphere, over a period of twelve months. After regular intervals of weathering, samples of the three base coals (Illinois No. 6, Pittsburgh No. 8 and Upper Freeport PA) were collected and shipped to both the University of Pittsburgh and the University of California at Berkeley for characterization studies of the weathered material. 29 figs., 29 tabs.

Fuerstenau, D.W.; Sastry, K.V.S.; Hanson, J.S.; Diao, J.; De, A.; Sotillo, F.; Harris, G. (California Univ., Berkeley, CA (United States)); Somasundaran, P.; Harris, C.C.; Vasudevan, T.; Liu, D.; Li, C. (Columbia Univ., New York, NY (United States)); Hu, Weibai; Zou, Y.; Chen, W. (Utah Univ., Salt Lake City, UT (United States)); Choudhry, V.; Sehgal, R.; Ghosh, A. (Praxis Engineers, Inc., Milpitas, CA (United

1991-07-30

271

Private development of artificial reefs  

E-print Network

this development scheme an entrepreneur would have the exclusive right to fish in the waters surrounding an artificial reef and would charge fishermen for the use of the reef. The concerns of a potential investor addressed by this thesis are (1) the effects... have limited funds T e re erences in this thesis follow the style of the Coastal Zone Mana ement Journal. for such projects, and lack the profit incentive which mo- tivates suppliers to meet demands for their resources. It can also be argued...

Burns, Arthur Allen

1978-01-01

272

Selective flotation of fossil resin from Western coal. Final report, July 1, 1990--May 25, 1992  

SciTech Connect

The proof-of-concept test program was designed to clarify a number of concerns that have been raised by coal companies who own the valuable resin resource. First, from laboratory bench-scale flotation experiments, a froth product from cleaner flotation containing more than 80% hexane-extractable resin at higher than 80% recovery can be produced. Pilot-plant testing was initiated to demonstrate the selective flotation of fossil resin and to establish a better confidence level in the new technology. Second, pilot-plant testing was designed to evaluate the effect and impact of random variation in slurry solids concentration and feed grade on this new selective fossil resin flotation technology. The flotation performance obtained under these industrial conditions is more realistic for process evaluation. Third, more accurate operating cost data was to be obtained for economic analysis. Fourth, sufficient quantities of the fossil resin concentrate were to be produced from the test program for evaluation by potential industrial users. Fifth, and finally, optimum levels for the operating variables were to be established. Such information was required for eventual scale-up and design of a fossil resin flotation plant. The pilot-plant proof-of-concept testing of selective resinate flotation has demonstrated that: (1) technically, the new flotation technologies discovered at the University of Utah and then improved upon by Advanced Processing Technologies, Inc. provide a highly efficient means to selectively recover fossil resin from coal. The proof-of-concept continuous flotation circuit (about 0.1 tph) resulted in fossil resin recovery with the same separation efficiency as was obtained from laboratory bench-scale testing (more than 80% recovery at about 80% concentrate grade); and (2) economically, the selective flotation process has been shown to be sufficiently profitable to justify the development of a fossil resin industry based on this new flotation process.

Jensen, G.F.; Miller, J.D.

1992-05-25

273

The future of coral reefs  

PubMed Central

Coral reefs, with their millions of species, have changed profoundly because of the effects of people, and will continue to do so for the foreseeable future. Reefs are subject to many of the same processes that affect other human-dominated ecosystems, but some special features merit emphasis: (i) Many dominant reef builders spawn eggs and sperm into the water column, where fertilization occurs. They are thus particularly vulnerable to Allee effects, including potential extinction associated with chronic reproductive failure. (ii) The corals likely to be most resistant to the effects of habitat degradation are small, short-lived “weedy” corals that have limited dispersal capabilities at the larval stage. Habitat degradation, together with habitat fragmentation, will therefore lead to the establishment of genetically isolated clusters of inbreeding corals. (iii) Increases in average sea temperatures by as little as 1°C, a likely result of global climate change, can cause coral “bleaching” (the breakdown of coral–algal symbiosis), changes in symbiont communities, and coral death. (iv) The activities of people near reefs increase both fishing pressure and nutrient inputs. In general, these processes favor more rapidly growing competitors, often fleshy seaweeds, and may also result in explosions of predator populations. (v) Combinations of stress appear to be associated with threshold responses and ecological surprises, including devastating pathogen outbreaks. (vi) The fossil record suggests that corals as a group are more likely to suffer extinctions than some of the groups that associate with them, whose habitat requirements may be less stringent. PMID:11344288

Knowlton, Nancy

2001-01-01

274

Quantifying Coral Reef Ecosystem Services  

EPA Science Inventory

Coral reefs have been declining during the last four decades as a result of both local and global anthropogenic stresses. Numerous research efforts to elucidate the nature, causes, magnitude, and potential remedies for the decline have led to the widely held belief that the recov...

275

Sandstone Spire in Capitol Reef  

USGS Multimedia Gallery

A view of a sandstone spire in Capitol Reef National Park. This area, known as the Fruita, is made up of three primary layers. The bottom sandstone layer is known as the Moenkopi Formation and is about 245 million years old. The middle gray-green layer is known as the Chinle Formation and was laid d...

276

The future of coral reefs.  

PubMed

Coral reefs, with their millions of species, have changed profoundly because of the effects of people, and will continue to do so for the foreseeable future. Reefs are subject to many of the same processes that affect other human-dominated ecosystems, but some special features merit emphasis: (i) Many dominant reef builders spawn eggs and sperm into the water column, where fertilization occurs. They are thus particularly vulnerable to Allee effects, including potential extinction associated with chronic reproductive failure. (ii) The corals likely to be most resistant to the effects of habitat degradation are small, short-lived "weedy" corals that have limited dispersal capabilities at the larval stage. Habitat degradation, together with habitat fragmentation, will therefore lead to the establishment of genetically isolated clusters of inbreeding corals. (iii) Increases in average sea temperatures by as little as 1 degrees C, a likely result of global climate change, can cause coral "bleaching" (the breakdown of coral-algal symbiosis), changes in symbiont communities, and coral death. (iv) The activities of people near reefs increase both fishing pressure and nutrient inputs. In general, these processes favor more rapidly growing competitors, often fleshy seaweeds, and may also result in explosions of predator populations. (v) Combinations of stress appear to be associated with threshold responses and ecological surprises, including devastating pathogen outbreaks. (vi) The fossil record suggests that corals as a group are more likely to suffer extinctions than some of the groups that associate with them, whose habitat requirements may be less stringent. PMID:11344288

Knowlton, N

2001-05-01

277

The future of coral reefs  

NASA Astrophysics Data System (ADS)

Coral reefs, with their millions of species, have changed profoundly because of the effects of people, and will continue to do so for the foreseeable future. Reefs are subject to many of the same processes that affect other human-dominated ecosystems, but some special features merit emphasis: (i) Many dominant reef builders spawn eggs and sperm into the water column, where fertilization occurs. They are thus particularly vulnerable to Allee effects, including potential extinction associated with chronic reproductive failure. (ii) The corals likely to be most resistant to the effects of habitat degradation are small, short-lived "weedy" corals that have limited dispersal capabilities at the larval stage. Habitat degradation, together with habitat fragmentation, will therefore lead to the establishment of genetically isolated clusters of inbreeding corals. (iii) Increases in average sea temperatures by as little as 1°C, a likely result of global climate change, can cause coral "bleaching" (the breakdown of coral-algal symbiosis), changes in symbiont communities, and coral death. (iv) The activities of people near reefs increase both fishing pressure and nutrient inputs. In general, these processes favor more rapidly growing competitors, often fleshy seaweeds, and may also result in explosions of predator populations. (v) Combinations of stress appear to be associated with threshold responses and ecological surprises, including devastating pathogen outbreaks. (vi) The fossil record suggests that corals as a group are more likely to suffer extinctions than some of the groups that associate with them, whose habitat requirements may be less stringent.

Knowlton, Nancy

2001-05-01

278

Sublittoral Reef Phenomena of Aldabra  

Microsoft Academic Search

DURING phase 6 of the Royal Society expedition to Aldabra the sublittoral structure of the reef front was studied by means of one detailed reference transect (marked 1 in Fig. 1) and thirteen survey transects. All were levelled by SCUBA divers in the following way. Two divers holding the ends of a 10 m tape ``leapfrogged'' over each other in

J. Barnes; D. J. Bellamy; D. J. Jones; B. A. Whitton

1970-01-01

279

Softened-Stainless-Steel O-Rings  

NASA Technical Reports Server (NTRS)

In fabrication of O-ring of new type, tube of 304 stainless steel bent around mandril into circle and welded closed into ring. Ring annealed in furnace to make it soft and highly ductile. In this condition, used as crushable, deformable O-ring seal. O-ring replacements used in variety of atmospheres and temperatures, relatively inexpensive, fabricated with minimum amount of work, amenable to one-of-a-kind production, reusable, and environmentally benign.

Marquis, G. A.; Waters, William I.

1993-01-01

280

Sintering Characteristics of Indian Chrome Ore Fines  

NASA Astrophysics Data System (ADS)

Chrome ore concentrate consists of high-temperature melting oxides such as Cr2O3, MgO, and Al2O3. The presence of these refractory constituents makes the ore a very high melting mineral. Hence, it is difficult to produce sinter from chrome ore by a pyrometallurgical route. Currently, chrome ore is ground to below 75 ?m, pelletized, heat hardened through carbothermic reaction at 1300 °C to 1400 °C, and then charged into a submerged electric arc furnace (EAF), along with lumpy ore for ferrochrome/charge-chrome production. Electricity is a major cost element in this extraction process. This work explores the sinterability of chrome ore. The objective of this study was to: (1) determine whether chrome ore is sinterable and, if so, (2) ascertain ways of achieving satisfactory properties at a low temperature of sintering. Sintering of the raw material feed could be a way to reduce electricity consumption, because during sintering a partial reduction of minerals is expected along with agglomeration. Studies carried out by the authors show that it is possible to agglomerate chrome ore fines through sintering. The chrome ore sinter thus produced was found to be inferior in strength, comparable to that of an iron ore sinter, but strength requirements may not be the same for both. Because the heat generation during chrome ore sintering is high owing to some exothermic reactions, compared with iron ore, and because chrome ore contains a high amount of fines, shallow-bed-depth sinter cake production was attempted in the laboratory-scale pot-sintering machine. The sintered product was found to be a good conductor of electricity because of the presence of phases such as magnetite and maghemite. This characteristic of the chrome ore sinter will subsequently have a favorable impact in terms of power consumption during the production of ferrochrome in a submerged EAF. The sinter made was melted in the arc furnace and it was found that the specific melting energy is comparable to that of heat-hardened chrome ore pellets but lower than briquettes and lump ore.

Nandy, Bikash; Chaudhury, Manoj Kumar; Paul, Jagannath; Bhattacharjee, D.

2009-10-01

281

Effects of island mass: Water flow and plankton pattern around a reef in the Great Barrier Reef lagoon, Australia  

Microsoft Academic Search

Water currents and zooplankton distributions are described for Pandora Reef, a coralline platform reef topped by a small sand spit, subject to tidal currents within the Great Barrier Reef lagoon (Queensland, Australia). Oncoming tidal currents separated 500 m upstream of the l-km oblong reef. Zooplankton accumulated around the reef variously according to taxo- nomic group. Copepods and chaetognaths were most

W. M. HAMNER; I. R. HAURI

1981-01-01

282

Coral Reefs (2005) 24: 593 DOI 10.1007/s00338-005-0043-zReef sites  

E-print Network

Coral Reefs (2005) 24: 593 DOI 10.1007/s00338-005-0043-zReef sites Fig. 2 Fossil coral reef in southern Exmouth Gulf, Western Australia. The fossil coral reef is exposed at Point Maxwell et al. (1998) and White et al. (1998). U-series dates obtained from reef corals preserved

Greenstein, Benjamin J.

283

Land-based nutrient enrichment of the Buccoo Reef Complex and fringing coral reefs of Tobago, West Indies  

E-print Network

Land-based nutrient enrichment of the Buccoo Reef Complex and fringing coral reefs of Tobago, West 33701, USA a r t i c l e i n f o Keywords: Coral reef Macroalgae Eutrophication Sewage Nitrogen of Tobago's coral reefs. Ă? 2009 Elsevier Ltd. All rights reserved. 1. Introduction Coral reefs

Meyers, Steven D.

284

IDENTIFICATION AND GAIN-SCHEDULED CONTROL OF A PILOT FLOTATION COLUMN  

Microsoft Academic Search

Since measurements of recovery and grade are often complex and inaccurate, flotation columns are controlled using secondary variables, such as froth depth, bias and gas hold-up. This paper describes the control of the froth depth of a pilot flotation column by manipulating the tails flow rate. Using a virtual froth depth sensor, it is shown that the model explaining the

A. Desbiens; R. del Villar; M. Milot

285

Fat removal from process waters of the fish meal industry. A study of three flotation methods  

Microsoft Academic Search

Dissolved air flotation (DAF), column flotation and electroflotation were assayed as methods for fat removal from process waters (condensates) produced during fish meal manufacture. DAF of the effluent was carried out in both batch and continuous modes at bench scale. The DAF method exhibited low efficiency in floating emulsified fat. Only a 34% of fat removal was attained. However, upon

M. Cristina Marti; Marlene Roeckel; Estrella Aspe; Manuel Novoa

1994-01-01

286

Development of a Froth Flotation Process for Recovery of Used Emulsifiable Oil  

Microsoft Academic Search

The separation behavior of the lubricating oil from wastewater was studied using the technique; electroflotation. The optimum conditions for oil flotation were determined and the results were discussed according to a kinetic model. Further, the surface properties of the cationic collector were investigated. Cement kiln dust was used as an adsorbent applied to the flotation solution to investigate the kinetic

H. I. Nabih; A. M. A. Omar; F. I. Kenawi

2003-01-01

287

IMPROVED FLOTATION TECHNIQUE FOR MICROSCOPY OF 'IN SITU' SOIL AND SEDIMENT MICROORGANISMS  

EPA Science Inventory

An improved flotation method for microscopical examination of in situ soil and sediment microorganisms was developed. Microbial cells were released into gel-like flotation films that were stripped from soil and sediment aggregates as these aggregates were submerged in 0.5% soluti...

288

MINI BAJA `10 Provide adequate flotation for correct tire depth, and driver com-  

E-print Network

Frame Drivetrain Controls Suspension Flotation MINI BAJA `10 Goals Provide adequate flotation a dual chain and sprocket setup. Engine 10 hp Briggs & Stratton Purchased through SAE Cannot be modified were left in tact that were required for mounts or as safety requirements by SAE Collision Load

New Hampshire, University of

289

Diagnosis of concentrate grade and mass flowrate in tin flotation from colour and surface texture analysis  

Microsoft Academic Search

It has long been accepted that the visual appearance of a froth is generally a good qualitative indicator as to the performance of the flotation process. This paper describes work which has been undertaken to investigate the possibility of using this premise to develop an on-line control system for the flotation process using image analysis.The emerging technologies of image analysis

J. M. Hargrave; S. T. Hall

1997-01-01

290

STUDIES ON THE APPLICATION OF ALKYL PHOSPHORIC ACID ESTER IN THE FLOTATION OF WOLFRAMITE  

Microsoft Academic Search

The application of alkyl phosphoric acid ester for the flotation of wolframite was investigated. The studies include flotation of pure wolframite as a function of pulp pH, surfactant concentration, and particle size. The response contours were explained on the basis of solution properties of alkyl phosphoric acid ester. The performance of alkyl phosphoric acid collector has been compared with other

K. SRINIVAS; T. SREENIVAS; N. P. H. PADMANABHAN; R. VENUGOPAL

2004-01-01

291

Flotation-spectrophotometric determination of rhodium using stannous chloride and Rhodamine 6G  

Microsoft Academic Search

Summary The conditions for the formation of a rhodium compound with tin(II) and Rhodamine 6G, in HCl medium, and their flotation with organic solvents of low polarity have been examined. The effect of the organic solvent on the flotation has been observed. The compound with Rhodamine 6G, separated and washed, is dissolved in acetone. The acetone solution is a basis

Krzysztof Kalinowski; Zygmunt Marczenko

1985-01-01

292

Separation of membranes by flotation centrifugation for in vitro synthesis of plant cell wall polysaccharides  

Microsoft Academic Search

Summary Membranes from etiolated maize seedlings were isolated using sucrose gradients for in vitro studies of polysaccharide synthesis. Following downward centrifugation, flotation centrifugation improved the purity of membrane fractions, in particular the Golgi apparatus. Based on naphthylphthalamic acid binding to plasma membrane and inosine-5'-diphosphatase activity in Golgi apparatus, flotation centrifugation removed about 70% of the plasma membrane which cosedimented with

D. M. Gibeaut; N. C. Carpita

1990-01-01

293

Battelle developing reefs to ease habitat losses  

SciTech Connect

Artificial reefs may be the answer to solving a worldwide problem of declining fish habitats, or they may only be good for creating fishing spots. Researchers at Battelle's Ocean Sciences Laboratory in Duxbury, Massachusetts, are studying artificial reefs in the Delaware River to determine if they are a solution to habitat losses in estuaries and coastal regions. [open quotes]Right now, we don't know if the fish are using the reefs simply as a grazing land, and then moving on, or if they're using the areas to colonize,[close quotes] said researcher Karen Foster. [open quotes]Ultimately, we hope to find they are colonizing.[close quotes] In 1989, Battelle researchers placed 16 prefabricated concrete reefs 45 feet deep in Delaware Bay. The reefs were placed in clusters of four, and monitoring began the following year. The federal government ordered the reefs placed in the bay as a mitigation technique for fish habitat that was lost when the river was dredged for navigational purposes. Researchers examined the reefs twice last summer. It will take five years, Foster said, before researchers can determine if the reefs are increasing the fish population. Early tests show, however, the populations of mussels, sponges, corals, and anemones increased by up to 150 percent over an area of bay bottom where the reefs were placed. Divers take crustacean samples from the reefs, and fish are caught near the reefs for examination. Researchers dissect the fish stomachs and analyze the contents to determine if they have been feeding at the reefs. [open quotes]If we find blue mussels in the stomach of the fish, that's great because we know that blue mussels are growing on the reef,[close quotes] Foster said.

Not Available

1993-04-01

294

Fringing and Nearshore Coral Reefs of the Great Barrier Reef: Episodic Holocene Development and Future Prospects  

Microsoft Academic Search

SMITHERS, S.G.; HOPLEY, D., and PARNELL, K.E., 2006. Fringing and nearshore coral reefs of the Great Barrier Reef: episodic Holocene development and future prospects. Journal of Coastal Research, 22(1), 175-187. West Palm Beach (Florida), ISSN 0749-0208. The Holocene growth of fringing and nearshore reefs on the GBR is examined. A review of data from 21 reefs indicates that most grow

S. G. Smithers; D. Hopley; K. E. Parnell

2006-01-01

295

Sedimentation on three caribbean atolls: Glovers reef, lighthouse reef and turneffe Islands, belize  

Microsoft Academic Search

Summary  The chief mode of carbonate sedimentation on the Belizean atolls Glovers Reef, Lighthouse Reef and Turneffe Islands is the\\u000a accumulation of organically-derived particles. Variations in the distribution of the composition and grain-sizes of surface\\u000a sediments, collected along transects across the atolls, are environmentally controlled. Two major sediment types may be distinguished.\\u000a (1) Reef and fore reef sediments are dominated by

Eberhard Gischler

1994-01-01

296

Delineating optimal settlement areas of juvenile reef fish in Ngederrak Reef, Koror state, Republic of Palau.  

PubMed

Establishing the effectiveness of habitat features to act as surrogate measures of diversity and abundance of juvenile reef fish provides information that is critical to coral reef management. When accurately set on a broader spatial context, microhabitat information becomes more meaningful and its management application becomes more explicit. The goal of the study is to identify coral reef areas potentially important to juvenile fishes in Ngederrak Reef, Republic of Palau, across different spatial scales. To achieve this, the study requires the accomplishment of the following tasks: (1) structurally differentiate the general microhabitat types using acoustics; (2) quantify microhabitat association with juvenile reef fish community structure; and (3) conduct spatial analysis of the reef-wide data and locate areas optimal for juvenile reef fish settlement. The results strongly suggest the importance of branching structures in determining species count and abundance of juvenile reef fish at the outer reef slope of Ngederrak Reef. In the acoustic map, the accurate delineation of these features allowed us to identify reef areas with the highest potential to harbor a rich aggregation of juvenile reef fish. Using a developed spatial analysis tool that ranks pixel groups based on user-defined parameters, the reef area near the Western channel of Ngederrak is predicted to have the most robust aggregation of juvenile reef fish. The results have important implications not only in management, but also in modeling the impacts of habitat loss on reef fish community. At least for Ngederrak Reef, the results advanced the utility of acoustic systems in predicting spatial distribution of juvenile fish. PMID:25394769

Ticzon, Victor S; Foster, Greg; David, Laura T; Mumby, Peter J; Samaniego, Badi R; Madrid, Val Randolf

2015-01-01

297

Astronaut Photography of Coral Reefs  

NASA Technical Reports Server (NTRS)

Astronaut photographs of tropical coastal areas may contain information on submerged features, including coral reefs, up to depths of about 15 m in clear waters. Previous research efforts have shown that astronaut photographs can aid in estimating coral reef locations and extent on national, regional and global scales, and allow characterization of major geomorphological rim and lagoon features (Andrefouet et al. 2000, in preparation). They can be combined with traditional satellite data to help distinguish between clouds and lagoon features such as pinnacles (Andrefouet and Robinson, in review). Furthermore, astronaut photographs may provide reef scientists and managers with information on the location and extent of river plumes and sediment run off, or facilitate identification of land cover types, including mangroves (Webb et al., in press). Photographs included in the section were selected based on several criteria. The primary consideration of the editors was that the photographs represent a worldwide distribution of coral reefs, have extremely low visual interference by cloud cover, and display a spatial scale reasonable for examining reef-related features. Once photographs were selected, they were digitized from 2nd generation copies. The color and contrast were hand corrected to an approximation of natural color (required to account for spectral differences between photographs due to the color sensitivities of films used, and differences in sun angle and exposure of the photographs). None of the photographs shown here have been georeferenced to correct them to a map projection and scale. Any distortions in features due to slightly oblique look angles when the photographs were taken through spacecraft windows remain. When feasible, near vertical photographs have been rotated so that north is toward the top. An approximate scale bar and north arrow have added using distinctive features on each photograph with reference to a 1:1,000,000 scale navigation chart. Astronaut photographs provide a unique source of moderate resolution reef remote sensing data because of their global coverage and (immediate) availability in the public domain. The database of photographs can be searched an browsed online and high-resolution digital copies of photographs in this atlas can be accessed via the Website of Earth Science and Image Analysis at NASA's Johnson Space Center:

Robinson, Julie A.; Noordeloos, Marco

2001-01-01

298

Dissolved air flotation of polishing wastewater from semiconductor manufacturer.  

PubMed

The feasibility of the dissolved air flotation (DAF) process in treating chemical mechanical polishing (CMP) wastewater was evaluated in this study. Wastewater from a local semiconductor manufacturer was sampled and characterised. Nano-sized silica (77.6 nm) with turbidity of 130 +/- 3 NTU was found in the slightly alkaline wastewater with traces of other pollutants. Experimental results indicated removal efficiency of particles, measured as suspended particle or turbidity, increased with increasing concentration of cationic collector cetyltrimethyl ammonium bromide (CTAB). When CTAB concentration was 30 mg/L, pH of 6.5 +/- 0.1 and recycle ratio of 30%, very effective removal of particles (> 98%) was observed in saturation pressure range of 4 to 6 kg/cm2, and the reaction proceeded faster under higher pressure. Similarly, the reaction was faster under the higher recycle ratio, while final removal efficiency improved slightly as the recycle ratio increased from 20 to 40%. An insignificant effect of pH on treatment efficiency was found as pH varied from 4.5 to 8.5. The presence of activator, Al3+ and Fe3+, enhanced the system performance. It is proposed that CTAB adsorbs on silica particles in polishing wastewater through electrostatic interaction and makes particles more hydrophobic. The increase in hydrophobicity results in more effective bubble-particle collisions. In addition, flocculation of silica particles through bridging effect of collector was found; it is believed that flocculation of particles also contributed to flotation. Better attachment between gas bubble and solid, higher buoyancy and higher air to solid ratio all lead to effective flotation. PMID:16752774

Liu, J C; Lien, C Y

2006-01-01

299

Microfacies and diagenesis of older Pleistocene (pre-last glacial maximum) reef deposits, Great Barrier Reef,  

E-print Network

Expedition 325, 34 holes were drilled along five transects in front of the Great Barrier Reef of Australia, Great Barrier Reef Environmental Changes, Integrated Ocean Drilling Program, microfacies, PleistoceneMicrofacies and diagenesis of older Pleistocene (pre-last glacial maximum) reef deposits, Great

Schöne, Bernd R.

300

Estimates of adult and juvenile mortality for labrid fishes at One Tree Reef, Great Barrier Reef  

Microsoft Academic Search

Few estimates of natural mortality have been reported for coral reef fishes, yet this information is essential for predicting the effects of recruitment fluctuations on adult populations. In this study, mortality of adult (10 species) and juvenile (11 species) labrid fishes resident on ten isolated patch reefs in One Tree Lagoon, southern Great Barrier Reef, was estimated by visual censuses

G. J. Eckert

1987-01-01

301

Uptake of picophytoplankton, bacterioplankton and virioplankton by a fringing coral reef community (Ningaloo Reef, Australia)  

NASA Astrophysics Data System (ADS)

We examined the importance of picoplankton and virioplankton to reef trophodynamics at Ningaloo Reef, (north-western Australia), in May and November 2008. Picophytoplankton ( Prochlorococcus, Synechococcus and picoeukaryotes), bacterioplankton (inclusive of bacteria and Archaea), virioplankton and chlorophyll a (Chl a) were measured at five stations following the consistent wave-driven unidirectional mean flow path of seawater across the reef and into the lagoon. Prochlorococcus, Synechococcus, picoeukaryotes and bacterioplankton were depleted to similar levels (~40% on average) over the fore reef, reef crest and reef flat (=`active reef'), with negligible uptake occurring over the sandy bottom lagoon. Depletion of virioplankton also occurred but to more variable levels. Highest uptake rates, m, of picoplankton occurred over the reef crest, while uptake coefficients, S (independent of cell concentration), were similarly scaled over the reef zones, indicating no preferential uptake of any one group. Collectively, picophytoplankton, bacterioplankton and virioplankton accounted for the uptake of 29 mmol C m-2 day-1, with Synechococcus contributing the highest proportion of the removed C. Picoplankton and virioplankton accounted for 1-5 mmol N m-2 day-1 of the removed N, with bacterioplankton estimated to be a highly rich source of N. Results indicate the importance of ocean-reef interactions and the dependence of certain reef organisms on picoplanktonic supply for reef-level biogeochemistry processes.

Patten, N. L.; Wyatt, A. S. J.; Lowe, R. J.; Waite, A. M.

2011-09-01

302

CONDITION OF CORAL REEF ECOSYSTEMS IN CENTRAL-SOUTHERN QUINTANA ROO (PART 2: REEF FISH COMMUNITIES)  

Microsoft Academic Search

Increases of fishing and tourism threaten the natural relationships between reef fish communities and their environments. All species of reef fishes were visually assessed in the central and southern Mexican Caribbean in eight fringing reefs, four of which are in a protected biosphere reserve. The sampling design included three spatial scales from tens of meters to tens of kilometers. A

ENRIQUE NÚŃEZ-LARA; CARLOS GONZÁLEZ-SALAS; MIGUEL A. RUIZ-ZÁRATE; ROBERTO HERNÁNDEZ-LANDA; J. ERNESTO ARIAS-GONZÁLEZ

303

Effects of fishing on tropical reef associated shark populations on the Great Barrier Reef  

Microsoft Academic Search

Three data sets were examined to define the level of interaction of reef associated sharks with the commercial Coral Reef Fin Fish Fishery within the Great Barrier Reef (GBR). Data were examined from fishery logbooks, an observer program within the fishery and a fishery-independent survey conducted as part of the Effects of Line Fishing (ELF) Experiment. The majority of the

M. R. Heupel; A. J. Williams; D. J. Welch; A. Ballagh; B. D. Mapstone; G. Carlos; C. Davies; C. A. Simpfendorfer

2009-01-01

304

Uptake of picophytoplankton, bacterioplankton and virioplankton by a fringing coral reef community (Ningaloo Reef, Australia)  

Microsoft Academic Search

We examined the importance of picoplankton and virioplankton to reef trophodynamics at Ningaloo Reef, (north-western Australia), in May and November 2008. Picophytoplankton ( Prochlorococcus, Synechococcus and picoeukaryotes), bacterioplankton (inclusive of bacteria and Archaea), virioplankton and chlorophyll a (Chl a) were measured at five stations following the consistent wave-driven unidirectional mean flow path of seawater across the reef and into the

N. L. Patten; A. S. J. Wyatt; R. J. Lowe; A. M. Waite

2011-01-01

305

ReefLink Database: A decision support tool for Linking Coral Reefs and Society Through Systems Thinking  

EPA Science Inventory

Coral reefs provide the ecological foundation for productive and diverse fish and invertebrate communities that support multibillion dollar reef fishing and tourism industries. Yet reefs are threatened by growing coastal development, climate change, and over-exploitation. A key i...

306

Continuous Steelmaking Directly from Ore  

NASA Astrophysics Data System (ADS)

In-line continuous processing of high-grade hematite ore (crushed ore or fines) with a pure hydrogen reductant is assessed. An appraisal is made of the rate controlling mechanisms involved in the reduction of a pure layer of molten wustite being transported by floating on a molten carrier iron carbon-free medium at temperatures just in excess of the iron melting point. Published research clearly indicates that under these conditions the kinetics are principally controlled by molecular gaseous diffusion. Thus, the rate is essentially not influenced by total gas pressure above 1 atmosphere. Accordingly, on safety grounds it is recommended that high pressure should not be used for hydrogen steelmaking in the future, but the operation should be conducted close to atmospheric pressure with low pressure steam encapsulation of the plant items involved. Using hydrogen as the reductant means that sub-surface nucleation of CO bubbles cannot disrupt continuous processing. The operation is then no different to processing a normal liquid phase. The off-gases from the reduction zone of a melt circulation loop are super-clean and only contaminated with iron vapor. Accordingly, the best available technology becomes available for energy conservation without risk of non-fusible solids deposition. The net result is that the energy requirements are expected to be superior to other potential processes.

Warner, Noel A.

2014-12-01

307

Coal surface control for advanced fine coal flotation  

SciTech Connect

The initial goal of the research project was to develop methods of coal surface control in advanced froth flotation to achieve 90% pyritic sulfur rejection, while operating at Btu recoveries above 90% based on run-of-mine quality coal. Moreover, the technology is to concomitantly reduce the ash content significantly (to six percent or less) to provide a high-quality fuel to the boiler (ash removal also increases Btu content, which in turn decreases a coal's emission potential in terms of lbs SO{sub 2}/million Btu). (VC)

Fuerstenau, D.W.; Hanson, J.S.; Diao, J.; Harris, G.H.; De, A.; Sotillo, F. (California Univ., Berkeley, CA (United States)); Somasundaran, P.; Harris, C.C.; Vasudevan, T.; Liu, D.; Li, C. (Columbia Univ., New York, NY (United States)); Hu, W.; Zou, Y.; Chen, W. (Utah Univ., Salt Lake City, UT (United States)); Choudhry, V.; Shea, S.; Ghosh, A.; Sehgal, R. (Praxis Engineers, Inc., Milpitas, CA (United States))

1992-03-01

308

Community ecology of mesophotic coral reef ecosystems  

Microsoft Academic Search

Given the global degradation of shallow-water coral reef ecosystems resulting from anthropogenic activities, mesophotic coral\\u000a reef ecosystems (MCEs) are gaining attention because they are generally considered a de facto refuge for shallow-water species.\\u000a Despite their inferred importance, MCEs remain one of the most understudied reef habitats, and basic information on the taxonomic\\u000a composition, depth range, habitat preferences, and abundance and

S. E. Kahng; J. R. Garcia-Sais; H. L. Spalding; E. Brokovich; D. Wagner; E. Weil; L. Hinderstein; R. J. Toonen

2010-01-01

309

Coral reef ecosystems and anthropogenic climate change  

Microsoft Academic Search

Coral reef ecosystems are among the most biologically diverse ecosystems on the planet. In addition to their value in terms\\u000a of biodiversity, coral reefs provide food and resources for over 500 million people. Despite their importance, coral reefs\\u000a are declining at a rapid rate (1–2% per year) as a result of a range of local (e.g., overexploitation of fisheries, declining\\u000a water

Ove Hoegh-Guldberg

2011-01-01

310

Atlantic coral reefs: the transplantation alternative  

Microsoft Academic Search

Although all of the world’s coral reef regions have suffered degradation due to direct and indirect human influences, only\\u000a the Western Atlantic reefs have declined to the extent that their continued existence appears to be in jeopardy. Of a once\\u000a flourishing reef system, only about 10% is still alive and it is depauperate in terms of the food web diversity

John C. Briggs

2009-01-01

311

Rigs to reefs: a petroleum industry perspective  

E-print Network

are in the Gulf of Nexico. These structures are, in effect, de facto artificial reefs, providing marine habitat while producing oil and gas. However, these structures are removed once hydrocarbon production ceases. With removal goes the loss of important... cost provides an economic disincentive to companies to participate in a rigs-to-reefs effort. The costs can be reduced by creating additional artificial reef sites, particularly sites close to areas where offshore platforms are located...

Dubose, William Perry

1988-01-01

312

Artificial reefs: from waste to resources  

Microsoft Academic Search

Waste materials, often referred to as “materials-of-opportunity,” have been the primary components used for constructing artificial reefs. Ships, barges, airplanes, automobiles, concrete debris, tires, and many other waste items have been disposed of at sea, with the added benefit of providing artificial reef habitat for environmental enhancement, fishing reefs, and interesting dive sites for eco-tourism. The latest development in artificial

Lee E. Harris; Benjamin J. Mostkoff; G. Zadikoff

1996-01-01

313

Climate change and coral reef connectivity  

Microsoft Academic Search

This review assesses and predicts the impacts that rapid climate change will have on population connectivity in coral reef\\u000a ecosystems, using fishes as a model group. Increased ocean temperatures are expected to accelerate larval development, potentially\\u000a leading to reduced pelagic durations and earlier reef-seeking behaviour. Depending on the spatial arrangement of reefs, the\\u000a expectation would be a reduction in dispersal

P. L. Munday; J. M. Leis; J. M. Lough; C. B. Paris; M. J. Kingsford; M. L. Berumen; J. Lambrechts

2009-01-01

314

Microorganisms and exogenous ore genesis as shown by studies of phosphorite, bauxites and manganese ores  

NASA Astrophysics Data System (ADS)

Hundreds of specimens of phosphorites, bauxites and manganese ores of different genetic types from all continents, from Quarternary to Proterozoic by age were studied with SEM analysis. Mineralized remains of prokaryotes and to less degree of eukaryotes made up the majority of such unchanged ores. The process of replication of biological fabric with different ore matters is general and determining for the origin of these ores, though for bauxites is characteristic somewhat pure chemical deposition during initial transformation stage of host rocks. Highly productively during initial stages of the ore genesis favors for phosphate and manganese ores, beside some other factors. The microbiota actively take part in decomposition of rocks during bauxite genesis side by side with forming of ore biomorphoses.

Shkolnik, Emil L.; Zhegallo, Elena A.; Eganov, Eric A.; Bogatyryov, B. A.; Bugelskii, Yu. Y.; Novikov, V. M.; Slukin, A. D.

2003-01-01

315

Ore-blending optimization model for sintering process based on characteristics of iron ores  

NASA Astrophysics Data System (ADS)

An ore-blending optimization model for the sintering process is an intelligent system that includes iron ore characteristics, expert knowledge and material balance. In the present work, 14 indices are proposed to represent chemical composition, granulating properties and high temperature properties of iron ores. After the relationships between iron ore characteristics and sintering performance are established, the "two-step" method and the simplex method are introduced to build the model by distinguishing the calculation of optimized blending proportion of iron ores from that of other sintering materials in order to improve calculation efficiency. The ore-blending optimization model, programmed by Access and Visual Basic, is applied to practical production in steel mills and the results prove that the present model can take advantage of the available iron ore resource with stable sinter yield and quality performance but at a lower cost.

Wu, Sheng-Li; Oliveira, Dauter; Dai, Yu-Ming; Xu, Jian

2012-03-01

316

Onondage pinnacle reefs in New York State  

SciTech Connect

Onondaga pinnacle reefs, part of the Onondaga Formation, developed in an epeiric setting of the lowermost Middle Devonian (Eifelian). The reefs were initiated as coral-crinoidal mounds in the Edgecliff Member of the formation. Whereas most Devonian reefs are composed of rugose corals. Coral is the predominant kind of fossil, followed by crinoids, brachiopods, mollusks, undifferentiated skeletal debris, and possible sponges. The initial mineralogy of the corals is inferred to have been calcite. The porosity of these reefs is almost unique among reef reservoirs. most reefs produce from secondary or diagenetic porosity; by contrast Onondaga reefs display primary intracoralline or framework porosity. Between framework builders and/or skeletal particles cryptocrystalline/microcrystalline cement fills pores. As observed in modern reefs this kind of cement resembles micrite, but probable formed as high-magnesian calcite in a high-energy setting. Syntaxial or rim cement common lines crinoid particles. Some of these pinnacle reefs, formerly gas producers, are presently under development as gas-storage reservoirs.

Friedman, G.M. [Brooklyn College and Graduate School of CUNY, Brooklyn, NY (United States)

1995-09-01

317

Satellite Remote Sensing of Coral Reefs  

NSDL National Science Digital Library

Coral reefs are one of the most endangered ecosystems as coral reef coverage has declined dramatically in the past three decades. In recent years, satellite remote sensing has become a popular and effective mapping tool for ecological studies, especially in marine science. This lesson plan designed for high school science students demonstrates how marine scientists use satellite remote sensing to gather detailed information about coral reefs worldwide. An in-depth review of both remote sensing and coral reefs is also included in this article.

Palandro, David; Muller-Karger, Frank; Kusek, Kristen; Thoms, Kristin; Greely, Teresa

2005-09-01

318

Impacts of Artificial Reefs on Surrounding Ecosystems  

NASA Astrophysics Data System (ADS)

Artificial reefs are becoming a popular biological and management component in shallow water environments characterized by soft seabed, representing both important marine habitats and tools to manage coastal fisheries and resources. An artificial reef in the marine environment acts as an open system with exchange of material and energy, altering the physical and biological characteristics of the surrounding area. Reef stability will depend on the balance of scour, settlement, and burial resulting from ocean conditions over time. Because of the unstable nature of sediments, they require a detailed and systematic investigation. Acoustic systems like high-frequency multibeam sonar are efficient tools in monitoring the environmental evolution around artificial reefs, whereas water turbidity can limit visual dive and ROV inspections. A high-frequency multibeam echo sounder offers the potential of detecting fine-scale distribution of reef units, providing an unprecedented level of resolution, coverage, and spatial definition. How do artificial reefs change over time in relation to the coastal processes? How accurately does multibeam technology map different typologies of artificial modules of known size and shape? How do artificial reefs affect fish school behavior? What are the limitations of multibeam technology for investigating fish school distribution as well as spatial and temporal changes? This study addresses the above questions and presents results of a new approach for artificial reef seafloor mapping over time, based upon an integrated analysis of multibeam swath bathymetry data and geoscientific information (backscatter data analysis, SCUBA observations, physical oceanographic data, and previous findings on the geology and sedimentation processes, integrated with unpublished data) from Senigallia artificial reef, northwestern Adriatic Sea (Italy) and St. Petersburg Beach Reef, west-central Florida continental shelf. A new approach for observation of fish aggregations associated with Senigallia reef based on the analysis of multibeam backscatter data in the water column is also explored. The settlement of the reefs and any terrain change are investigated over time providing a useful description of the local hydrodynamics and geological processes. All the artificial structures (made up by water-based concrete for Senigallia reef and mainly steel for St. Petersburg Beach reef) are identified and those showing substantial horizontal and/or vertical movements are analyzed in detail. Most artificial modules of Senigallia reef are not intact and scour signatures are well depicted around them, indicating reversals of the local current. This is due to both the wind pattern and to the quite close arrangement of the reef units that tend to deflect the bottom flow. As regards to the St. Petersburg Beach reef, all the man-made steel units are still in their upright position. Only a large barge shows a gradual collapse of its south side, and presents well-developed scouring at its east-northeast side, indicating dominant bottom flow from west-southwest to east-northeast. While an overall seafloor depth shallowing of about 0.30 m from down-current deposits was observed for Senigallia reef, an overall deepening of about 0.08 m due to scour was observed at the St. Petersburg Beach reef. Based on the backscatter data interpretation, surficial sediments are coarser in the vicinities of both artificial reefs than corresponding surrounding sediments. Scouring reveals this coarser layer underneath the prevalent mud sediment at Senigallia reef, and the predominant silt sediment at St. Petersburg Beach reef. In the ten years of Senigalia reef study, large-scale variations between clay and silt appear to be directly linked to large flood events that have occurred just prior to the change. As regards the water column investigation, acoustic backscatter from fish aggregations gives detailed information on their morphology and spatial distribution. In addition, relative fish biomass estimates can be extrapolated. Results suggest that most of

Manoukian, Sarine

319

Nocturnal relocation of adult and juvenile coral reef fishes in response to reef noise  

NASA Astrophysics Data System (ADS)

Juvenile and adult reef fishes often undergo migration, ontogenic habitat shifts, and nocturnal foraging movements. The orientation cues used for these behaviours are largely unknown. In this study, the use of sound as an orientation cue guiding the nocturnal movements of adult and juvenile reef fishes at Lizard Island, Great Barrier Reef was examined. The first experiment compared the movements of fishes to small patch reefs where reef noise was broadcast, with those to silent reefs. No significant responses were found in the 79 adults that were collected, but the 166 juveniles collected showed an increased diversity each morning on the reefs with broadcast noise, and significantly greater numbers of juveniles from three taxa (Apogonidae, Gobiidae and Pinguipedidae) were collected from reefs with broadcast noise. The second experiment compared the movement of adult and juvenile fishes to reefs broadcasting high (>570 Hz), or low (<570 Hz) frequency reef noise, or to silent reefs. Of the 122 adults collected, the highest diversity was seen at the low frequency reefs; and adults from two families (Gobiidae and Blenniidae) preferred these reefs. A similar trend was observed in the 372 juveniles collected, with higher diversity at the reefs with low frequency noises. This preference was seen in the juvenile apogonids; however, juvenile gobiids were attracted to both high and low sound treatments equally, and juvenile stage Acanthuridae preferred the high frequency noises. This evidence that juvenile and adult reef fishes orientate with respect to the soundscape raises important issues for management, conservation and the protection of sound cues used in natural behaviour.

Simpson, S. D.; Jeffs, A.; Montgomery, J. C.; McCauley, R. D.; Meekan, M. G.

2008-03-01

320

Nanoparticle flotation collectors--the influence of particle softness.  

PubMed

The ability of polymeric nanoparticles to promote glass bead and pentlandite (Pn, nickel sulfide mineral) attachment to air bubbles in flotation was measured as a function of the nanoparticle glass transition temperature using six types of nanoparticles based on styrene/N-butylacrylate copolymers. Nanoparticle size, surface charge density, and hydrophobicity were approximately constant over the series. The ability of the nanoparticles to promote air bubble attachment and perform as flotation collectors was significantly greater for softer nanoparticles. We propose that softer nanoparticles were more firmly attached to the glass beads or mineral surface because the softer particles had a greater glass/polymer contact areas and thus stronger overall adhesion. The diameters of the contact areas between polymeric nanoparticles and glass surfaces were estimated with the Young-Laplace equation for soft, liquidlike particles, whereas JKR adhesion theory was applied to the harder polystyrene particles. The diameters of the contact areas were estimated to be more than an order of magnitude greater for the soft particles compared to harder polystyrene particles. PMID:23692163

Yang, Songtao; Razavizadeh, Bi Bi Marzieh; Pelton, Robert; Bruin, Gerard

2013-06-12

321

Enhanced desulfurizing flotation of coal using sonoelectrochemical method.  

PubMed

Enhanced desulfurizing flotation of low sulfur coal was investigated using sonoelectrochemical method. The supporting electrolyte used in this process was sodium chloride and the additive was anhydrous ethanol. The effects of treatment conditions on desulfurization were studied by a single-factor method. The conditions include anhydrous ethanol concentration, sodium chloride concentration, sonoelectrolytic voltage, sonoelectrolytic temperature, sonoelectrolytic time and coal sample granulometry. The optimal experimental conditions achieved for anhydrous ethanol concentration, sodium chloride concentration, sonoelectrolytic voltage, sonoelectrolytic temperature and sonoelectrolytic time are 1.7 mol L(-1), 5.1×10(-3) mol L(-1), 10 V, 70 °C, 50 min achieved for a -0.18 mm coal sample. Optimal conditions cause a sulfur reduction of up to 69.4%. The raw and treated coals were analyzed by infrared spectroscopy and a chemical method. Pyritic sulfur, organic sulfur, ash as well as moisture are partially removed. The combination of high sulfur reduction, high yield, as well as high ash reduction was obtained in the newly developed method of enhanced flotation by sonoelectrochemistry. Ultrasound irradiation promotes electron transfer efficiency and increases clean coal yield. PMID:23558374

Zhang, Hong-Xi; Hou, Xiao-Yang; Xu, Shi-Xun; Li, Zhi-Long; Yu, Hai-Feng; Shen, Xue-Hua

2013-09-01

322

Inclusion flotation-driven channel segregation in solidifying steels.  

PubMed

Channel segregation, which is featured by the strip-like shape with compositional variation in cast materials due to density contrast-induced flow during solidification, frequently causes the severe destruction of homogeneity and some fatal damage. An investigation of its mechanism sheds light on the understanding and control of the channel segregation formation in solidifying metals, such as steels. Until now, it still remains controversial what composes the density contrasts and, to what extent, how it affects channel segregation. Here we discover a new force of inclusion flotation that drives the occurrence of channel segregation. It originates from oxide-based inclusions (Al2O3/MnS) and their sufficient volume fraction-driven flotation becomes stronger than the traditionally recognized inter-dendritic thermosolutal buoyancy, inducing the destabilization of the mushy zone and dominating the formation of channels. This study uncovers the mystery of oxygen in steels, extends the classical macro-segregation theory and highlights a significant technological breakthrough to control macrosegregation. PMID:25422943

Li, Dianzhong; Chen, Xing-Qiu; Fu, Paixian; Ma, Xiaoping; Liu, Hongwei; Chen, Yun; Cao, Yanfei; Luan, Yikun; Li, Yiyi

2014-01-01

323

Inclusion flotation-driven channel segregation in solidifying steels  

PubMed Central

Channel segregation, which is featured by the strip-like shape with compositional variation in cast materials due to density contrast-induced flow during solidification, frequently causes the severe destruction of homogeneity and some fatal damage. An investigation of its mechanism sheds light on the understanding and control of the channel segregation formation in solidifying metals, such as steels. Until now, it still remains controversial what composes the density contrasts and, to what extent, how it affects channel segregation. Here we discover a new force of inclusion flotation that drives the occurrence of channel segregation. It originates from oxide-based inclusions (Al2O3/MnS) and their sufficient volume fraction-driven flotation becomes stronger than the traditionally recognized inter-dendritic thermosolutal buoyancy, inducing the destabilization of the mushy zone and dominating the formation of channels. This study uncovers the mystery of oxygen in steels, extends the classical macro-segregation theory and highlights a significant technological breakthrough to control macrosegregation. PMID:25422943

Li, Dianzhong; Chen, Xing-Qiu; Fu, Paixian; Ma, Xiaoping; Liu, Hongwei; Chen, Yun; Cao, Yanfei; Luan, Yikun; Li, Yiyi

2014-01-01

324

Inclusion flotation-driven channel segregation in solidifying steels  

NASA Astrophysics Data System (ADS)

Channel segregation, which is featured by the strip-like shape with compositional variation in cast materials due to density contrast-induced flow during solidification, frequently causes the severe destruction of homogeneity and some fatal damage. An investigation of its mechanism sheds light on the understanding and control of the channel segregation formation in solidifying metals, such as steels. Until now, it still remains controversial what composes the density contrasts and, to what extent, how it affects channel segregation. Here we discover a new force of inclusion flotation that drives the occurrence of channel segregation. It originates from oxide-based inclusions (Al2O3/MnS) and their sufficient volume fraction-driven flotation becomes stronger than the traditionally recognized inter-dendritic thermosolutal buoyancy, inducing the destabilization of the mushy zone and dominating the formation of channels. This study uncovers the mystery of oxygen in steels, extends the classical macro-segregation theory and highlights a significant technological breakthrough to control macrosegregation.

Li, Dianzhong; Chen, Xing-Qiu; Fu, Paixian; Ma, Xiaoping; Liu, Hongwei; Chen, Yun; Cao, Yanfei; Luan, Yikun; Li, Yiyi

2014-11-01

325

Removal of cadmium (II) from simulated wastewater by ion flotation technique  

PubMed Central

A separation technique which has recently received a sharp increase in research activities is “ion flotation”. This technique has four important advantages for treating wastewaters: low energy consumption, small space requirements, small volume of sludge and acting selectively. The present study aims to optimize parameters of ion flotation for cadmium removal in simulated wastewater at laboratory scale. It was obtained on the reaction between Cd2+ and sodium dodecylesulfate (SDS) collector followed by flotation with ethanol as frother. Test solution was prepared by combining the required amount of cadmium ion, SDS and necessary frother or sodium sulfate solution. All experiments were carried out in a flotation column at laboratory temperature (27°C), adjusted pH = 4 and 120 minutes. The different parameters (namely: flow rate, cadmium, SDS and frother concentrations and ionic strength) influencing the flotation process were examined. The best removal efficiency obtained at a collector-metal ratio of 3:1 in 60 min with flow rate of 150 mL/min was 84%. The maximum cadmium removal was 92.1% where ethanol was introduced at a concentration 0.4% to flotation column with above conditions. The obtained results were promising, as both cadmium and collector were effectively removed from wastewater. Hence, the application of ion flotation for metal ions removal from effluents seems to be efficient. PMID:23388386

2013-01-01

326

Mapping Oyster Reef Habitats in Mobile Bay  

NASA Technical Reports Server (NTRS)

Oyster reefs around the world are declining rapidly, and although they haven t received as much attention as coral reefs, they are just as important to their local ecosystems and economies. Oyster reefs provide habitats for many species of fish, invertebrates, and crustaceans, as well as the next generations of oysters. Oysters are also harvested from many of these reefs and are an important segment of many local economies, including that of Mobile Bay, where oysters rank in the top five commercial marine species both by landed weight and by dollar value. Although the remaining Mobile Bay oyster reefs are some of the least degraded in the world, projected climate change could have dramatic effects on the health of these important ecosystems. The viability of oyster reefs depends on water depth and temperature, appropriate pH and salinity levels, and the amount of dissolved oxygen in the water. Projected increases in sea level, changes in precipitation and runoff patterns, and changes in pH resulting from increases in the amount of carbon dioxide dissolved in the oceans could all affect the viability of oyster reefs in the future. Human activities such as dredging and unsustainable harvesting practices are also adversely impacting the oyster reefs. Fortunately, several projects are already under way to help rebuild or support existing or previously existing oyster reefs. The success of these projects will depend on the local effects of climate change on the current and potential habitats and man s ability to recognize and halt unsustainable harvesting practices. As the extent and health of the reefs changes, it will have impacts on the Mobile Bay ecosystem and economy, changing the resources available to the people who live there and to the rest of the country, since Mobile Bay is an important national source of seafood. This project identified potential climate change impacts on the oyster reefs of Mobile Bay, including the possible addition of newly viable habitats in the southeastern regions of the Bay.

Bolte, Danielle

2011-01-01

327

Coral reef community composition in the context of disturbance history on the Great Barrier Reef, Australia.  

PubMed

Much research on coral reefs has documented differential declines in coral and associated organisms. In order to contextualise this general degradation, research on community composition is necessary in the context of varied disturbance histories and the biological processes and physical features thought to retard or promote recovery. We conducted a spatial assessment of coral reef communities across five reefs of the central Great Barrier Reef, Australia, with known disturbance histories, and assessed patterns of coral cover and community composition related to a range of other variables thought to be important for reef dynamics. Two of the reefs had not been extensively disturbed for at least 15 years prior to the surveys. Three of the reefs had been severely impacted by crown-of-thorns starfish outbreaks and coral bleaching approximately a decade before the surveys, from which only one of them was showing signs of recovery based on independent surveys. We incorporated wave exposure (sheltered and exposed) and reef zone (slope, crest and flat) into our design, providing a comprehensive assessment of the spatial patterns in community composition on these reefs. Categorising corals into life history groupings, we document major coral community differences in the unrecovered reefs, compared to the composition and covers found on the undisturbed reefs. The recovered reef, despite having similar coral cover, had a different community composition from the undisturbed reefs, which may indicate slow successional processes, or a different natural community dominance pattern due to hydrology and other oceanographic factors. The variables that best correlated with patterns in the coral community among sites included the density of juvenile corals, herbivore fish biomass, fish species richness and the cover of macroalgae. Given increasing impacts to the Great Barrier Reef, efforts to mitigate local stressors will be imperative to encouraging coral communities to persist into the future. PMID:24983747

Graham, Nicholas A J; Chong-Seng, Karen M; Huchery, Cindy; Januchowski-Hartley, Fraser A; Nash, Kirsty L

2014-01-01

328

Coral Reef Community Composition in the Context of Disturbance History on the Great Barrier Reef, Australia  

PubMed Central

Much research on coral reefs has documented differential declines in coral and associated organisms. In order to contextualise this general degradation, research on community composition is necessary in the context of varied disturbance histories and the biological processes and physical features thought to retard or promote recovery. We conducted a spatial assessment of coral reef communities across five reefs of the central Great Barrier Reef, Australia, with known disturbance histories, and assessed patterns of coral cover and community composition related to a range of other variables thought to be important for reef dynamics. Two of the reefs had not been extensively disturbed for at least 15 years prior to the surveys. Three of the reefs had been severely impacted by crown-of-thorns starfish outbreaks and coral bleaching approximately a decade before the surveys, from which only one of them was showing signs of recovery based on independent surveys. We incorporated wave exposure (sheltered and exposed) and reef zone (slope, crest and flat) into our design, providing a comprehensive assessment of the spatial patterns in community composition on these reefs. Categorising corals into life history groupings, we document major coral community differences in the unrecovered reefs, compared to the composition and covers found on the undisturbed reefs. The recovered reef, despite having similar coral cover, had a different community composition from the undisturbed reefs, which may indicate slow successional processes, or a different natural community dominance pattern due to hydrology and other oceanographic factors. The variables that best correlated with patterns in the coral community among sites included the density of juvenile corals, herbivore fish biomass, fish species richness and the cover of macroalgae. Given increasing impacts to the Great Barrier Reef, efforts to mitigate local stressors will be imperative to encouraging coral communities to persist into the future. PMID:24983747

Graham, Nicholas A. J.; Chong-Seng, Karen M.; Huchery, Cindy; Januchowski-Hartley, Fraser A.; Nash, Kirsty L.

2014-01-01

329

Hydrophobic Agglomeration of Mineral Fines in Aqueous Suspensions and its Application in Flotation: a Review  

NASA Astrophysics Data System (ADS)

Hydrophobic agglomeration is originated from the hydrophobic attraction between particles, which is essentially different from electrolyte coagulation and polymer flocculation. It is applied to mineral processing in floc-flotation process to improve the recovery of mineral fines. In this paper, the applications of this phenomenon in mineral fines were summarized, including the origin of hydrophobic agglomeration, the main factors affect hydrophobic agglomeration (particle hydrophobicity, shear rate and duration, nonpolar oil and tank geometry), as well as hydrophobic agglomeration based separation processes (carrier flotation and floc-flotation).

Yang, Bingqiao; Song, Shaoxian

2014-05-01

330

Project O.R.B (Operation Reef Ball): Creating Artificial Reefs, Educating the Community  

NASA Astrophysics Data System (ADS)

The Project O.R.B. (Operation Reef Ball) team at South Plantation High School's Everglades Restoration & Environmental Science Magnet Program is trying to help our ailing south Florida coral reefs by constructing, deploying, and monitoring designed artificial reefs. Students partnered with the Reef Ball Foundation, local concrete companies, state parks, Girl Scouts, Sea Scouts, local universities and environmental agencies to construct concrete reef balls, each weighing approximately 500 lbs (227 kg). Students then deployed two artificial reefs consisting of over 30 concrete reef balls in two sites previously permitted for artificial reef deployment. One artificial reef was placed approximately 1.5 miles (2.4 km) offshore of Golden Beach in Miami-Dade County with the assistance of Florida Atlantic University and their research vessel. A twin reef was deployed at the mouth of the river in Oleta River State Park in Miami. Monitoring and maintenance of the sites is ongoing with semi-annual reports due to the Reef Ball Foundation and DERM (Department of Environmental Resource Management) of Miami-Dade County. A second goal of Project O.R.B. is aligned with the Florida Local Action Strategy, the Southeast Florida Coral Reef Initiative, and the U.S. Coral Reef Task Force, all of which point out the importance of awareness and education as key components to the health of our coral reefs. Project O.R.B. team members developed and published an activity book targeting elementary school students. Outreach events incorporate cascade learning where high school students teach elementary and middle school students about various aspects of coral reefs through interactive "edu-tainment" modules. Attendees learn about water sampling, salinity, beach erosion, surface runoff, water cycle, ocean zones, anatomy of coral, human impact on corals, and characteristics of a well-designed artificial reef. Middle school students snorkel on the artificial reef to witness first-hand the success of this artificial reef. Over 3,000 students have been reached through the educational outreach endeavors of Project O.R.B. This successful STEM project models the benefits of partnerships with universities, local K-12 public schools and community conservation organizations and provides students with authentic learning experiences. Students are able to have a positive impact on their local coral reef environment, their peers and their community through this comprehensive service-learning project.

Phipps, A.

2012-04-01

331

Artificial Reefs--A Coastal Classroom Project.  

ERIC Educational Resources Information Center

Discusses the construction of artificial reefs for such uses as commercial fishing and recreational boating. Describes a class project in which students construct a small artificial reef and observe the changes over time in terms of temperature, salinity, flora and fauna. (TW)

Dindo, John J.

1986-01-01

332

Wonders of the Living Reef The Invertebrates  

Microsoft Academic Search

The living reef is a realm of wonders. With a first look at a living reef, one is overwhelmed with the diversity in color and shape of the corals and fishes. But beneath this surface is an even more wondrous world, one of bizarre, alien creatures, some of which hardly resemble living animals. These \\

Scott Johnson

333

Coral reef restoration projects in Thailand  

Microsoft Academic Search

The degradation and deterioration of coral reefs in Thailand has continued for several decades due to pressures from fishery and tourism activities and, more recently, from bleaching. Several institutions and organizations, from both the government and the private sector, have been involved in programs to restore degraded coral reefs. The objectives, scales and methods of these restoration projects have varied

Thamasak Yeemin; Makamas Sutthacheep; Rattika Pettongma

2006-01-01

334

Development of contemporary Eastern Pacific coral reefs  

Microsoft Academic Search

An overview of oceanographic conditions prevailing in the tropical Eastern Pacific Ocean suggests that the entire region is environmentally marginal for coral-reef development. The principal features of this environment are a strong, permanent, shallow thermocline and an annual north-south migration of the Intertropical Convergence resulting in wet and dry seasons. Along tropical Eastern Pacific continental margins structural coral reefs are

T. F. Dana

1975-01-01

335

REEF MANAGER'S GUIDE TO CORAL BLEACHING  

EPA Science Inventory

A Reef Manager's Guide to Coral Bleaching is the result of a collaborative effort by over 50 scientists and managers to: (1) engage in information-sharing in the areas of coral reef science and management for climate change and coral bleaching; and (2) compile a management tool ...

336

Along-Track Reef Imaging System (ATRIS)  

USGS Publications Warehouse

"Along-Track Reef Imaging System (ATRIS)" describes the U.S. Geological Survey's Along-Track Reef Imaging System, a boat-based sensor package for rapidly mapping shallow water benthic environments. ATRIS acquires high resolution, color digital images that are accurately geo-located in real-time.

Brock, John; Zawada, Dave

2006-01-01

337

Sandstone Strata in Capitol Reef National Park  

USGS Multimedia Gallery

A detail view of some sandstone strata within Capitol Reef National Park. Capitol Reef is primarily made up of sandstone formations within the Waterpocket Fold, monocline that extends nearly 100 miles. A monocline is a step-like fold in rock strata that can resemble an enormous wrinkle in the earth....

338

Subtropical Biotic Fringing Reefs as Ecological Laboratories.  

ERIC Educational Resources Information Center

Describes a 16-week course in marine biology involving a class-coordinated investigation of a subtropical biotic fringing reef of Hawaii. Describes in detail the development of preliminary hypotheses regarding general cause-effect relationships on the reef, and the exploration of specific areas, such as chemical or physical factors. (CS)

Hunt, Jeffrey W.

1980-01-01

339

25. FRONT END LOADERS MOMENTARILY IN REPOSE IN THE ORE ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

25. FRONT END LOADERS MOMENTARILY IN REPOSE IN THE ORE STORAGE YARD. AN ORE BRIDGE THAT FORMERLY TRANSFERRED ORE WITHIN THE STORAGE YARD WAS DESTROYED BY A BLIZZARD IN 1978. - Pennsylvania Railway Ore Dock, Lake Erie at Whiskey Island, approximately 1.5 miles west of Public Square, Cleveland, Cuyahoga County, OH

340

36. ORE DOCK, LOOKING WEST. HULETT UNLOADERS AWAIT THE NEXT ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

36. ORE DOCK, LOOKING WEST. HULETT UNLOADERS AWAIT THE NEXT ORE BOAT. BY LATE WINTER, THE ORE STORAGE YARD SEEN AT LEFT WILL BE DEPLETED. - Pennsylvania Railway Ore Dock, Lake Erie at Whiskey Island, approximately 1.5 miles west of Public Square, Cleveland, Cuyahoga County, OH

341

Wave Forced Normal Modes on Fringing Reefs  

NASA Astrophysics Data System (ADS)

In an effort to assess wave-driven coastal inundation at the shoreline of fringing reefs, pressure and current observations were collected at reefs on Guam (Ipan) and Oahu, Hawaii (Mokuleia) as part of the PILOT (Pacific Island Land-Ocean Typhoon) experiment. Similar to dissipative sandy beaches, nearshore surface elevation at both reefs is dominated by energy in the infragravity frequency band. Coherent infragravity oscillations across the reef tend to occur at discrete frequencies and with standing wave cross-shore structures that are consistent with open basin resonant modes. The modes are forced by swell wave groups, similar to a time-dependent setup. The resonant modes are most apparent during energetic wave events, in part because wave setup over the reef increases the low mode resonant frequencies to a range that is conducive to wave group forcing. Evidence of the excitation of resonant modes during tropical storm Man-Yi at Ipan, Guam is presented.

Pequignet, A. N.; Becker, J. M.; Merrifield, M. M.; Aucan, J.

2008-12-01

342

Porosity evolution of upper Miocene reefs, Almeria Province, Southern Spain  

Microsoft Academic Search

In the reef cores and fore-reef breccia beds, porosity in both primary and postdepositional. Primary porosity is of three types: (a) boring clam holes in the scleractinian coral heads, cemented reef rocks, and breccias; (b) intraparticle porosity within the corals, Halimeda plates, and vermetid worm tubes; and (c) interparticle porosity between bioclastic fragments and in the reef breccia. Postdepositional moldic

A. K. Armstrong; P. D. Jr. Snavely; W. O. Addicott

1980-01-01

343

SIGHTINGS OF HUMPBACK WHALES IN GREAT BARRIER REEF WATERS  

E-print Network

SIGHTINGS OF HUMPBACK WHALES IN GREAT BARRIER REEF WATERS MARK L. SIMMONS* AND HELENE MARSH*+ ABSTRACT Oral J-ristoryintewiews indicate that humpback whales used to winter in Great Barrier Reef waters in the Great Barrier Reef lagoon. Some females "pp"...,ity ."r* before they reach reef waters. Hump6acks

Marsh, Helene

344

Shifting the paradigm of coral-reef ‘health’ assessment  

Microsoft Academic Search

Coral reefs are in crisis. Globally, our reefs are degrading at an accelerating rate and present methodologies for coral-reef ‘health’ assessment, although providing important information in describing these global declines, have been unable to halt these declines. These assessments are usually employed with no clear purpose and using uncorrelated methods resulting in a failure to prevent or mitigate coral reef

Craig A. Downs; Cheryl M. Woodley; Robert H. Richmond; Lynda L. Lanning; Richard Owen

2005-01-01

345

Science and management of coral reefs: problems and prospects  

Microsoft Academic Search

It should be recognised that many principles of reef management do not need further research, as they involve changing human behaviour and activities in order to remove or reduce impacts on reefs. Much of the time of a reef manager is taken up with social, economic and political issues: the integration of reef management into broad coastal zone management objectives;

S. M. Wells

1995-01-01

346

Community Structure of Pleistocene Coral Reefs of Curacao, Netherlands Antilles  

Microsoft Academic Search

The Quaternary fossil record of living coral reefs is fundamental for un- derstanding modern ecological patterns. Living reefs generally accumulate in place, so fossil reefs record a history of their former biological inhabitants and physical environments. Reef corals record their ecological history especially well because they form large, resistant skeletons, which can be identified to species. Thus, presence-absence and relative

John M. Pandolfi; Jeremy B. C. Jackson

2001-01-01

347

A Theoretical Model of Pattern Formation in Coral Reefs  

E-print Network

A Theoretical Model of Pattern Formation in Coral Reefs Susannah Mistr and David Bercovici to flow are qualitatively supported on both a colonial and a regional reef scale. Key words: coral reefs; pattern formation; self- organization; colonial organisms. INTRODUCTION Coral reefs are composed of small

348

Parrotfish abundance and selective corallivory on a Belizean coral reef  

E-print Network

Parrotfish abundance and selective corallivory on a Belizean coral reef Randi D. Rotjan *, Sara M of coral reef communities because they consume macroalgae that would otherwise outcompete reef grazing by parrotfish on particular coral species, differences in grazing incidence among reef habitats

Lewis, Sara

349

A Global Estimate of the Number of Coral Reef Fishers  

PubMed Central

Overfishing threatens coral reefs worldwide, yet there is no reliable estimate on the number of reef fishers globally. We address this data gap by quantifying the number of reef fishers on a global scale, using two approaches - the first estimates reef fishers as a proportion of the total number of marine fishers in a country, based on the ratio of reef-related to total marine fish landed values. The second estimates reef fishers as a function of coral reef area, rural coastal population, and fishing pressure. In total, we find that there are 6 million reef fishers in 99 reef countries and territories worldwide, of which at least 25% are reef gleaners. Our estimates are an improvement over most existing fisher population statistics, which tend to omit accounting for gleaners and reef fishers. Our results suggest that slightly over a quarter of the world’s small-scale fishers fish on coral reefs, and half of all coral reef fishers are in Southeast Asia. Coral reefs evidently support the socio-economic well-being of numerous coastal communities. By quantifying the number of people who are employed as reef fishers, we provide decision-makers with an important input into planning for sustainable coral reef fisheries at the appropriate scale. PMID:23840327

Teh, Louise S. L.; Teh, Lydia C. L.; Sumaila, U. Rashid

2013-01-01

350

Climate Change, Human Impacts, and the Resilience of Coral Reefs  

Microsoft Academic Search

The diversity, frequency, and scale of human impacts on coral reefs are increasing to the extent that reefs are threatened globally. Projected increases in carbon dioxide and temperature over the next 50 years exceed the conditions under which coral reefs have flourished over the past half-million years. However, reefs will change rather than disappear entirely, with some species already showing

T. P. Hughes; A. H. Baird; D. R. Bellwood; M. Card; S. R. Connolly; C. Folke; R. Grosberg; O. Hoegh-Guldberg; J. B. C. Jackson; J. Kleypas; J. M. Lough; P. Marshall; M. Nyström; S. R. Palumbi; J. M. Pandolfi; B. Rosen; J. Roughgarden

2003-01-01

351

Edgecliff reefs - Devonian temperate water carbonate deposition  

SciTech Connect

The Middle Devonian Edgecliff Member of the Onondaga Formation in New York and Ontario, Canada, is a coral-rich, reefy,' crinoidal grainstone/packstone. The reefs contain only rare stromatoporoids and are devoid of algae, having been constructed by a fauna of mound and thicket-forming branching colonial rugosans, and large sheet favositids that populated grainstone/packstone flank beds and banks. Despite the restricted fauna, the reefs display a variety of growth patterns. Rugosan mounds range in size from 2-3 m diameter by 1 m thick, up to 230 m diameter by 15 m thick. Composite structures consist of interbedded rugosan buildups and packstone/grainstone flanks, ranging from shield-shaped reefs (240 m diameter by 6 m thick) in which the rugosans occur only as thickets, to pinnacle reefs (up to 3 km diameter by 60 m thick) in which rugosan mounds are interbedded with crinoidal flanks. Geographic distribution of these reef types and analysis of surrounding facies suggests that reef growth pattern was controlled by water depth and local rate of subsidence. Despite superfacial resemblance to modern deep water ahermatypic coral mounds and thickets, abundant coral breakage and overturning, and erosion of at least one reef core during an intermediate stage of reef growth supports a shallow water origin of these reefs. It is suggested that the Edgecliff and its reefs represent an example of Devonian cool water carbonate deposition, a hypothesis supported by a trend of increasing stromatoporoid abundance westwards across New York (in the direction of the paleo-equator).

Wolosz, T.H. (State Univ. of New York, Plattsburgh (United States))

1991-03-01

352

Characterisation and Processing of Some Iron Ores of India  

NASA Astrophysics Data System (ADS)

Lack of process characterization data of the ores based on the granulometry, texture, mineralogy, physical, chemical, properties, merits and limitations of process, market and local conditions may mislead the mineral processing entrepreneur. The proper implementation of process characterization and geotechnical map data will result in optimized sustainable utilization of resource by processing. A few case studies of process characterization of some Indian iron ores are dealt with. The tentative ascending order of process refractoriness of iron ores is massive hematite/magnetite < marine black iron oxide sands < laminated soft friable siliceous ore fines < massive banded magnetite quartzite < laminated soft friable clayey aluminous ore fines < massive banded hematite quartzite/jasper < massive clayey hydrated iron oxide ore < manganese bearing iron ores massive < Ti-V bearing magnetite magmatic ore < ferruginous cherty quartzite. Based on diagnostic process characterization, the ores have been classified and generic process have been adopted for some Indian iron ores.

Krishna, S. J. G.; Patil, M. R.; Rudrappa, C.; Kumar, S. P.; Ravi, B. P.

2013-10-01

353

A novel reef coral symbiosis  

NASA Astrophysics Data System (ADS)

Reef building corals form close associations with unicellular microalgae, fungi, bacteria and archaea, some of which are symbiotic and which together form the coral holobiont. Associations with multicellular eukaryotes such as polychaete worms, bivalves and sponges are not generally considered to be symbiotic as the host responds to their presence by forming physical barriers with an active growth edge in the exoskeleton isolating the invader and, at a subcellular level, activating innate immune responses such as melanin deposition. This study describes a novel symbiosis between a newly described hydrozoan ( Zanclea margaritae sp. nov.) and the reef building coral Acropora muricata (= A. formosa), with the hydrozoan hydrorhiza ramifying throughout the coral tissues with no evidence of isolation or activation of the immune systems of the host. The hydrorhiza lacks a perisarc, which is typical of symbiotic species of this and related genera, including species that associate with other cnidarians such as octocorals. The symbiosis was observed at all sites investigated from two distant locations on the Great Barrier Reef, Australia, and appears to be host species specific, being found only in A. muricata and in none of 30 other species investigated at these sites. Not all colonies of A. muricata host the hydrozoans and both the prevalence within the coral population (mean = 66%) and density of emergent hydrozoan hydranths on the surface of the coral (mean = 4.3 cm-2, but up to 52 cm-2) vary between sites. The form of the symbiosis in terms of the mutualism-parasitism continuum is not known, although the hydrozoan possesses large stenotele nematocysts, which may be important for defence from predators and protozoan pathogens. This finding expands the known A. muricata holobiont and the association must be taken into account in future when determining the corals’ abilities to defend against predators and withstand stress.

Pantos, O.; Bythell, J. C.

2010-09-01

354

Islands, Reefs, and a Hotspot  

NSDL National Science Digital Library

In this lesson students investigate the formation of the Hawaiian archipelago to see what geological processes produced the different physical forms seen among the Hawaiian Islands. Students will be able to describe eight stages in the formation of islands in the Hawaiian archipelago and will describe the movement of tectonic plates in the region including submarine volcanic eruptions, caldera formation, erosion, coral reef building, and atoll stages. They will also learn how a combination of hotspot activity and tectonic plate movement could produce the arrangement of seamounts observed in the Hawaiian archipelago.

Mel Goodwin

355

ORE 642 Marine Environmental Remediation Designation  

E-print Network

ORE 642 Marine Environmental Remediation Designation Elective Catalog Description Thermodynamics, chemistry and measurements of marine pollutants, biodegradation and biotransformation of pollutants, regulations on marine environment. Pre: consent. Prerequisites by Topics Chemistry Fluid mechanics Textbook

Frandsen, Jannette B.

356

8. EAST ELEVATION OF SKIDOO MILL AND UPPER ORE BIN, ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

8. EAST ELEVATION OF SKIDOO MILL AND UPPER ORE BIN, LOOKING WEST FROM ACCESS ROAD. THE ROADWAY ON THIS LEVEL (CENTER) WAS USED FOR UNLOADING ORE BROUGHT ON BURROWS INTO THE ORE BIN AT THE TOP LEVEL OF THE MILL. THE ORE BIN IN THE UPPER LEFT WAS ADDED LATER WHEN ORE WAS BROUGHT TO THE MILL BY TRUCKS. - Skidoo Mine, Park Route 38 (Skidoo Road), Death Valley Junction, Inyo County, CA

357

Dual effects of sodium sulfide on the flotation behavior of chalcopyrite: I. Effect of pulp potential  

NASA Astrophysics Data System (ADS)

This study explores the flotation behavior of chalcopyrite in the presence of different concentrations of sodium sulfide (Na2S·9H2O) at pH 12 under controlled potential conditions. It was observed that the flotation of chalcopyrite is not depressed completely when the pulp potential is low, even at high concentrations of sodium sulfide, i.e., 10-1-10-2 mol/L. However, a partial and controlled oxidation of pulp does enhance the effectiveness of sodium sulfide on the depression of chalcopyrite. Characterization of the chalcopyrite particle surface by X-ray photoelectron spectroscopy allowed the identification of hydrophilic and hydrophobic surface species, which are responsible for the depression and flotation of chalcopyrite. Changes in pulp potential were found to be an effective float controlling parameter, by which Na2S can be used to initiate or depress the flotation behavior of chalcopyrite.

Taheri, Bijan; Abdollahy, Mahmoud; Tonkaboni, Sied Ziaedin Shafaei; Javadian, Soheyla; Yarahmadi, Mohammadreza

2014-05-01

358

Statistical Evaluation and Optimization of Factors Affecting the Leaching Performance of Copper Flotation Waste  

PubMed Central

Copper flotation waste is an industrial by-product material produced from the process of manufacturing copper. The main concern with respect to landfilling of copper flotation waste is the release of elements (e.g., salts and heavy metals) when in contact with water, that is, leaching. Copper flotation waste generally contains a significant amount of Cu together with trace elements of other toxic metals, such as Zn, Co, and Pb. The release of heavy metals into the environment has resulted in a number of environmental problems. The aim of this study is to investigate the leaching characteristics of copper flotation waste by use of the Box-Behnken experimental design approach. In order to obtain the optimized condition of leachability, a second-order model was examined. The best leaching conditions achieved were as follows: pH = 9, stirring time = 5?min, and temperature = 41.5°C. PMID:22629194

Çoruh, Semra; Elevli, Sermin; Geyikçi, Feza

2012-01-01

359

18 CFR 1304.400 - Flotation devices and material, all floating structures.  

Code of Federal Regulations, 2010 CFR

...Conservation of Power and Water Resources TENNESSEE VALLEY AUTHORITY APPROVAL OF CONSTRUCTION IN THE TENNESSEE RIVER SYSTEM AND REGULATION OF STRUCTURES...Every flotation device employed in the Tennessee River system must be firmly and...

2010-04-01

360

18 CFR 1304.400 - Flotation devices and material, all floating structures.  

Code of Federal Regulations, 2014 CFR

...Conservation of Power and Water Resources TENNESSEE VALLEY AUTHORITY APPROVAL OF CONSTRUCTION IN THE TENNESSEE RIVER SYSTEM AND REGULATION OF STRUCTURES...Every flotation device employed in the Tennessee River system must be firmly and...

2014-04-01

361

18 CFR 1304.400 - Flotation devices and material, all floating structures.  

Code of Federal Regulations, 2011 CFR

...Conservation of Power and Water Resources TENNESSEE VALLEY AUTHORITY APPROVAL OF CONSTRUCTION IN THE TENNESSEE RIVER SYSTEM AND REGULATION OF STRUCTURES...Every flotation device employed in the Tennessee River system must be firmly and...

2011-04-01

362

18 CFR 1304.400 - Flotation devices and material, all floating structures.  

Code of Federal Regulations, 2013 CFR

...Conservation of Power and Water Resources TENNESSEE VALLEY AUTHORITY APPROVAL OF CONSTRUCTION IN THE TENNESSEE RIVER SYSTEM AND REGULATION OF STRUCTURES...Every flotation device employed in the Tennessee River system must be firmly and...

2013-04-01

363

18 CFR 1304.400 - Flotation devices and material, all floating structures.  

Code of Federal Regulations, 2012 CFR

...Conservation of Power and Water Resources TENNESSEE VALLEY AUTHORITY APPROVAL OF CONSTRUCTION IN THE TENNESSEE RIVER SYSTEM AND REGULATION OF STRUCTURES...Every flotation device employed in the Tennessee River system must be firmly and...

2012-04-01

364

FOAM FLOTATION TREATMENT OF HEAVY METALS AND FLUORIDE-BEARING INDUSTRIAL WASTEWATERS  

EPA Science Inventory

Laboratory studies demonstrated that the floc foam flotation techniques are effective in removing lead, cadmium, mercury, copper, zinc, arsenic, and fluoride from dilute wastewaters to very low levels. Simulated as well as real industrial wastewaters were studied. Industrial wast...

365

Ecology of a Caribbean coral reef. The Porites reef-flat biotope: Part II. Plankton community with evidence for depletion  

Microsoft Academic Search

A quantitative assessment of drifting net plankton crossing a reef-flat biotope was obtained on a Caribbean coral reef. The spatial distribution and abundance of plankton were sampled to provide estimates of the removal of this potential food resource by suspension-feeding populations. Sampling was largely confined to the reef flat and adjacent waters of Laurel Cay, a flourishing coral reef present

P. W. Glynn

1973-01-01

366

Comparative evaluation of a modified zinc sulfate flotation technique.  

PubMed Central

A modified zinc sulfate flotation technique using Formalinized fecal specimens (F-ZnSO4) was compared to the Formalin-ether (FE) concentration method for the laboratory diagnosis of intestinal parasites. Many laboratories have difficulty storing, using, and disposing of either and need a procedure for concentrating fecal specimens which does not require ether. Comparative data were obtained for the recovery of protozoan cysts and helminth eggs and larvae from feces preserved in Formalin less than and longer than 1 month. Whereas the FE method was found generally to be more efficient, F-ZnSO4 was apparently more effective for the recovery of some species of parasites. F-ZnSO4 was not satisfactory for recovery of schistosome eggs. We conclude that, except for schistosomes, F-ZnSO4 compares favorably to the FE method for detecting infections of clinical significance. PMID:566767

Bartlett, M S; Harper, K; Smith, N; Verbanac, P; Smith, J W

1978-01-01

367

Biomining: metal recovery from ores with microorganisms.  

PubMed

Biomining is an increasingly applied biotechnological procedure for processing of ores in the mining industry (biohydrometallurgy). Nowadays the production of copper from low-grade ores is the most important industrial application and a significant part of world copper production already originates from heap or dump/stockpile bioleaching. Conceptual differences exist between the industrial processes of bioleaching and biooxidation. Bioleaching is a conversion of an insoluble valuable metal into a soluble form by means of microorganisms. In biooxidation, on the other hand, gold is predominantly unlocked from refractory ores in large-scale stirred-tank biooxidation arrangements for further processing steps. In addition to copper and gold production, biomining is also used to produce cobalt, nickel, zinc, and uranium. Up to now, biomining has merely been used as a procedure in the processing of sulfide ores and uranium ore, but laboratory and pilot procedures already exist for the processing of silicate and oxide ores (e.g., laterites), for leaching of processing residues or mine waste dumps (mine tailings), as well as for the extraction of metals from industrial residues and waste (recycling). This chapter estimates the world production of copper, gold, and other metals by means of biomining and chemical leaching (bio-/hydrometallurgy) compared with metal production by pyrometallurgical procedures, and describes new developments in biomining. In addition, an overview is given about metal sulfide oxidizing microorganisms, fundamentals of biomining including bioleaching mechanisms and interface processes, as well as anaerobic bioleaching and bioleaching with heterotrophic microorganisms. PMID:23793914

Schippers, Axel; Hedrich, Sabrina; Vasters, Jürgen; Drobe, Malte; Sand, Wolfgang; Willscher, Sabine

2014-01-01

368

Treatment of spent filter backwash water using dissolved air flotation.  

PubMed

There is increasing interest in treating recovered spent filter backwash water in the drinking water industry. In the USA the Filter Backwash Recycling Rule will come into effect in the near future. The purpose of the Rule is to prevent the concentrated pathogenic agents, potentially in the filter backwash water, from being returned to the head of the water treatment works without some form of treatment or dilution. By treating this flow both public health and financial liability can be better managed by the operating utility. Dissolved Air Flotation (DAF) was investigated as a possible technology alternative to simple or advanced sedimentation techniques. This application is not widespread but sits somewhere in between the two normal applications of DAF as a high solids sludge thickener and a low turbidity clarification system. Given this a pilot plant program, supported by jar testing, was undertaken to determine the process capability and the design parameters for this application. DAF proved to be very suitable for backwash water recovery. DAF effluent turbidities of < 1.0 NTU could be easily obtained, when raw water turbidities were in excess of 50 NTU. Chemical requirements were low with only a single low dose of polymer required to bind the floc particles to form a solids matrix suitable for flotation. Flocculation contact times ranged from 0-10 minutes depending on the nature of the raw water. Recycle rates as low as 5% performed satisfactorily with no significant improvement when increased to 20%. Sludge solids of 3.5-9.6% dry solids were found and very low volumes of sludge, < 0.1% of the incoming flow make the DAF solids handling system very compact. PMID:11394280

Eades, A; Bates, B J; MacPhee, M J

2001-01-01

369

Recovery of fine coal from waste streams using advanced column flotation  

SciTech Connect

The advanced flotation techniques, namely column flotation, have shown potential in obtaining a low ash, low pyritic sulfur fine size clean coal. The overall objective of this program is to evaluate applicability of an advanced flotation technique, 'Ken-Flote' column to recover clean coal with minimum mineral matter content at greater than 90 percent combustible recovery from two Illinois preparation plant waste streams. Column flotations tests were conducted on the flotation feed obtained from the Kerr-McGee Galatia and Ziegler No. 26 plants using three different bubble-generating devices: sparger, gas saver and foam jet. Each of these devices was tested with three different frothers and various column-operating variable to provide maximum combustible recovery, minimum product ash and maximum pyrite rejection. For the Galatia slurry, the column provided a clean coal containing 5 percent ash, 0.48 percent pyritic sulfur at combustible recovery averaging 90 percent. In other words, about 90 percent ash and about 75 percent pyritic sulfur rejection were attained for the Galatia slurry. Pilot plant studies on this slurry basically obtained results similar to the laboratory studies. For the Ziegler No. 26, slurry column flotation provided a clean coal containing about 5 percent ash, 0.44 percent pyritic sulfur at more than 90 percent combustible recovery. The ash and pyrite sulfur rejection was about 85 percent and 65 percent, respectively.

Groppo, J.G.

1991-01-01

370

Coral Reef Adventure Fun Zone  

NSDL National Science Digital Library

The Memory Game beginner is the best game for students of all ages to play unless there is a student who knows an unusual amount of information about coral reefs. In this case, that student can play the expert level where he/she will match the name or phrase with a picture.To begin, students should click on the GO! icon on the Memory Game and then again on the GO! icon on the pop-up screen. The beginner version requires students to match alike pictures. Students should click on the images to find the matching pairs. As they click on an image and then click on another, the previous image goes away if it's not a match.so students need to remember where they clicked on each image.Once students find a matching pair, they need to click on one image and then click on its matching image to keep the matching pair on the screen. Students should continue this process until all the images are found. On the bottom left of this screen there is a Move counter that keeps track of how many times students click on an image. If students want to try again to achieve a better score, then they can start the game over on a new screen. As noted below, there are other games that would be suitable for playing after students learn more about coral reefs.

Science NetLinks (AAAS;)

2007-04-29

371

Community structure and coral status across reef fishing intensity gradients in Palk Bay reef, southeast coast of India.  

PubMed

Coral reef fishes are exploited without the knowledge of their sustainability and their possible effect in altering the community structure of a coral reef ecosystem. Alteration of the community structure could cause a decline in the health of coral reefs and its services. We documented the coral community structure, status of live corals and reef fish assemblages in Palk Bay at the reef fishing hotspots and its nearby reef area with minimum fishing pressure and compared it with a control reef area where reef fishing was banned for more than two decades. The comparison was based on the percent cover of different forms of live corals, their diversity and the density and diversity of reef fishes. The reef fish stock in the reef fishing hotspots and its neighbouring reef was lower by 61 and 38%, respectively compared to the control reef. The herbivore fish Scarus ghobban and Siganus javus were exploited at a rate of 250 and 105 kg month(-1) fishermen(-1), respectively, relatively high comparing the small reef area. Live and dead corals colonized by turf algae were predominant in both the reef fishing hotspots and its nearby coral ecosystems. The percent cover of healthy live corals and live corals colonized by turf algae was <10 and >80%, respectively, in the intensively fished coral ecosystems. The corals were less diverse and the massive Porites and Favia colonies were abundant in the intensive reef fishing sites. Results of this study suggest that the impact of reef fish exploitation was not solely restricted to the intensively fished reefs, but also to the nearby reefs which play a critical role in the resilience of degraded reef ecosystems. PMID:24859909

Manikandan, B; Ravindran, J; Shrinivaasu, S; Marimuthu, N; Paramasivam, K

2014-10-01

372

Halimeda biomass, growth rates and sediment generation on reefs in the central great barrier reef province  

Microsoft Academic Search

The average biomass ofHalimeda per m2 of solid substratum increased progressively on a series of reefs situated at increasing distances from the shore in the central\\u000a Great Barrier Reef. There was none on a reef close inshore, increasing to nearly 500 g m?2 total biomass (?90% calcium carbonate) on an oceanic atoll system in the Coral Sea. The biomass measured

Edward A. Drew

1983-01-01

373

Nocturnal relocation of adult and juvenile coral reef fishes in response to reef noise  

Microsoft Academic Search

Juvenile and adult reef fishes often undergo migration, ontogenic habitat shifts, and nocturnal foraging movements. The orientation\\u000a cues used for these behaviours are largely unknown. In this study, the use of sound as an orientation cue guiding the nocturnal\\u000a movements of adult and juvenile reef fishes at Lizard Island, Great Barrier Reef was examined. The first experiment compared\\u000a the movements

S. D. Simpson; A. Jeffs; J. C. Montgomery; R. D. McCauley; M. G. Meekan

2008-01-01

374

Uptake of picophytoplankton, bacterioplankton and virioplankton by a fringing coral reef community (Ningaloo Reef, Australia)  

Microsoft Academic Search

We examined the importance of picoplankton and virioplankton to reef trophodynamics at Ningaloo Reef, (north-western Australia),\\u000a in May and November 2008. Picophytoplankton (Prochlorococcus, Synechococcus and picoeukaryotes), bacterioplankton (inclusive of bacteria and Archaea), virioplankton and chlorophyll a (Chl a) were measured at five stations following the consistent wave-driven unidirectional mean flow path of seawater across the\\u000a reef and into the lagoon.

N. L. PattenA; A. S. J. Wyatt; R. J. Lowe; A. M. Waite

2011-01-01

375

Antimony ore in the Fairbanks district, Alaska  

USGS Publications Warehouse

Antimony-bearing ores in the Fairbanks district, Alaska, are found principally in two areas, the extremities of which are at points 10 miles west and 23 miles northeast of Fairbanks; and one of two minor areas lies along this same trend 30 miles farther to the northeast. These areas are probably only local manifestations of mineralization that affected a much broader area and formed antimony-bearing deposits in neighboring districts, the closest of which is 50 miles away. The ores were exposed largely as a result of lode gold mining, but at two periods in the past, high prices for antimony ore warranted an independent production and about 2500 tons of stibnite ore was shipped. The sulfide deposits occupy the same fractures along which a gold-quartz mineralization of greater economic importance occurred; and both are probably genetically related to igneous rocks which intrude the schistose country rock. The sulfide is in part contemporaneous with some late-stage quartz in which it occurs as disseminated crystals; and in part the latest filling in the mineralized zones where it forms kidney-shaped masses of essentially solid sulfide. One extremely long mass must have contained nearly 100 tons of ore, but the average of the larger kidneys is closer to several tons. Much of the ore is stibnite, with quartz as a minor impurity, and assays show the tenor to vary from 40 to 65 percent antimony. Sulphantimonites are less abundant but likewise occur as disseminated crystals and as kidney-shaped bodies. Antimony oxides appear on the weathered surface and along fractures within the sulfide ore. Deposits containing either stibnite or sulphantimonite are known at more than 50 localities, but only eighteen have produced ore and the bulk of this came from the mines. The geology of the deposit, and the nature, extent, and period of the workings are covered in the detailed descriptions of individual occurrences. Several geologic and economic factors, which greatly affect prospecting and mining for stibnite ore in the area, are outlined. The principal available ore and reserves are considered to be ores earlier mined but never shipped, ore minable from near-surface deposits, and ores recoverable as a by-product of future gold mining. The outlook for stibnite production in the district is very uncertain. Apparently the greater portion of stibnite ore has already been recovered and present operations will strip the two principal areas of the district. This conclusion is based on the scanty discoveries since the last war and the fact that the areas are so pock-marked with prospects that there is little likelihood that any other large near-surface bodies remain to be discovered. Future prospecting would essentially be limited to attempts to seek the continuation of lodes previously having high yields of stibnite.

Killeen, Pemberton Lewis; Mertie, John B., Jr.

1951-01-01

376

Could some coral reefs become sponge reefs as our climate changes?  

PubMed

Coral reefs across the world have been seriously degraded and have a bleak future in response to predicted global warming and ocean acidification (OA). However, this is not the first time that biocalcifying organisms, including corals, have faced the threat of extinction. The end-Triassic mass extinction (200 million years ago) was the most severe biotic crisis experienced by modern marine invertebrates, which selected against biocalcifiers; this was followed by the proliferation of another invertebrate group, sponges. The duration of this sponge-dominated period far surpasses that of alternative stable-ecosystem or phase-shift states reported on modern day coral reefs and, as such, a shift to sponge-dominated reefs warrants serious consideration as one future trajectory of coral reefs. We hypothesise that some coral reefs of today may become sponge reefs in the future, as sponges and corals respond differently to changing ocean chemistry and environmental conditions. To support this hypothesis, we discuss: (i) the presence of sponge reefs in the geological record; (ii) reported shifts from coral- to sponge-dominated systems; and (iii) direct and indirect responses of the sponge holobiont and its constituent parts (host and symbionts) to changes in temperature and pH. Based on this evidence, we propose that sponges may be one group to benefit from projected climate change and ocean acidification scenarios, and that increased sponge abundance represents a possible future trajectory for some coral reefs, which would have important implications for overall reef functioning. PMID:23553821

Bell, James J; Davy, Simon K; Jones, Timothy; Taylor, Michael W; Webster, Nicole S

2013-09-01

377

Reef fish and habitat relationships in a Caribbean seascape: the importance of reef context  

NASA Astrophysics Data System (ADS)

Marine protected area (MPA) effectiveness is contingent on understanding key ecological patterns and processes at appropriate spatial scales and may depend upon maintaining critical linkages among essential habitat patches to conserve reef-fish communities. Hypotheses were tested to investigate the importance of habitat linkages in the US Virgin Islands. As expected, reef context (the spatial pattern of surrounding habitat patches) was a strong predictor of reef fish assemblage structure. Specific relationships were functionally consistent with the ecology of the fishes of interest. For example, reefs with large amounts of seagrass nearby harbored the greatest numerical abundance of fishes, particularly mobile invertebrate feeders and the exploited fish families of Haemulidae (grunts) and Lutjanidae (snappers). Species richness for the entire fish community and within these fish groups was also strongly associated with reef context. Furthermore, reef fish mobility influenced how fishes related to reef context. Fish-habitat relationships were detected as far as 1 km from study reefs, suggesting that fish movements result in habitat encounter rates that may influence their patterns of distribution. Consequently, functional habitat connectivity of habitat patches appears important in structuring reef-fish assemblages, and suggests that landscape-scale metrics may provide insights useful to managers in the design of MPAs.

Grober-Dunsmore, R.; Frazer, T. K.; Lindberg, W. J.; Beets, J.

2007-03-01

378

Florida's Fragile Reefs: What's Happening to this Underwater World?  

NSDL National Science Digital Library

This BioBulletin Web site takes an in-depth look at coral reefs and how they are affected by human activities: everything from agricultural pollution and ship grounding to snorkeling and overfishing. With Florida's fragile reefs as the backdrop, the site includes text, videos and photographs. The Introduction explains the fragility of these the massive underwater structures. What Are Reefs? discusses how these "rain forests of the sea" support an even more astonishing variety of life. Reefs in Hot Water presents the factors behind why reefs around the world are declining at an unprecedented rate. Monitoring a Reef at Risk covers the Florida Keys Coral Reef Monitoring Project, funded by the Environmental Protection Agency. Treating Reefs Right lists ways in which boaters, fishermen, swimmers, and divers can do their part to protect coral reefs.

379

Coral reefs of the Mascarenes, Western Indian Ocean.  

PubMed

The reefs of the Mascarenes differ in structure and stage of development. Mauritius is the oldest island, bound by a discontinuous fringing reef and small barrier reef, with large lagoon patch reefs. Rodrigues has nearly continuous fringing reefs bounding an extensive lagoon with deep channels and few patch reefs. Reunion, the youngest island, has short stretches of narrow fringing reefs along southwestern coasts. The islets of St Brandon are bound to the east by an extensive arc of fringing reef. Reef mapping of the Mascarenes using satellite imagery provides an estimate of 705 km2 of shallow reef habitats. These areas have been modified over geological time by changes in sea level, ocean-atmosphere disturbances and biological and chemical forcing. Further modification has resulted from historical changes in land-use patterns. Recent economic development has placed many of these reefs at risk from anthropogenic impact. The reefs of the Mascarenes have escaped mass mortality from bleaching to date, which increases their conservation significance within the wider Indian Ocean. The reefs are poorly protected. A case study shows how a geographic information system incorporating reef-habitat maps can help formulate and demonstrate Marine Protected Area boundaries. PMID:15598634

Turner, John; Klaus, Rebecca

2005-01-15

380

MANGROVE-DERIVED NUTRIENTS AND CORAL REEFS  

EPA Science Inventory

Understanding the consequences of the declining global cover of mangroves due to anthropogenic disturbance necessitates consideration of how mangrove-derived nutrients contribute to threatened coral reef systems. We sampled potential sources of organic matter and a suite of sessi...

381

Ocean acidification impairs vermetid reef recruitment  

NASA Astrophysics Data System (ADS)

Vermetids form reefs in sub-tropical and warm-temperate waters that protect coasts from erosion, regulate sediment transport and accumulation, serve as carbon sinks and provide habitat for other species. The gastropods that form these reefs brood encapsulated larvae; they are threatened by rapid environmental changes since their ability to disperse is very limited. We used transplant experiments along a natural CO2 gradient to assess ocean acidification effects on the reef-building gastropod Dendropoma petraeum. We found that although D. petraeum were able to reproduce and brood at elevated levels of CO2, recruitment success was adversely affected. Long-term exposure to acidified conditions predicted for the year 2100 and beyond caused shell dissolution and a significant increase in shell Mg content. Unless CO2 emissions are reduced and conservation measures taken, our results suggest these reefs are in danger of extinction within this century, with significant ecological and socioeconomic ramifications for coastal systems.

Milazzo, Marco; Rodolfo-Metalpa, Riccardo; Chan, Vera Bin San; Fine, Maoz; Alessi, Cinzia; Thiyagarajan, Vengatesen; Hall-Spencer, Jason M.; Chemello, Renato

2014-02-01

382

Explore coral reefs around the world  

NSDL National Science Digital Library

This interactive map shows examples of coral reef locations in the Pacific, Caribbean, and Indian oceans. By clicking on a location, you can see the environmental conditions necessary for growth in terms of both ocean depth and sea surface tempature.

TERC

383

Ocean acidification impairs vermetid reef recruitment.  

PubMed

Vermetids form reefs in sub-tropical and warm-temperate waters that protect coasts from erosion, regulate sediment transport and accumulation, serve as carbon sinks and provide habitat for other species. The gastropods that form these reefs brood encapsulated larvae; they are threatened by rapid environmental changes since their ability to disperse is very limited. We used transplant experiments along a natural CO2 gradient to assess ocean acidification effects on the reef-building gastropod Dendropoma petraeum. We found that although D. petraeum were able to reproduce and brood at elevated levels of CO2, recruitment success was adversely affected. Long-term exposure to acidified conditions predicted for the year 2100 and beyond caused shell dissolution and a significant increase in shell Mg content. Unless CO2 emissions are reduced and conservation measures taken, our results suggest these reefs are in danger of extinction within this century, with significant ecological and socioeconomic ramifications for coastal systems. PMID:24577050

Milazzo, Marco; Rodolfo-Metalpa, Riccardo; Chan, Vera Bin San; Fine, Maoz; Alessi, Cinzia; Thiyagarajan, Vengatesen; Hall-Spencer, Jason M; Chemello, Renato

2014-01-01

384

Reef Ecosystem Services and Decision Support Database  

EPA Science Inventory

This scientific and management information database utilizes systems thinking to describe the linkages between decisions, human activities, and provisioning of reef ecosystem goods and services. This database provides: (1) Hierarchy of related topics - Click on topics to navigat...

385

Extinction vulnerability of coral reef fishes.  

PubMed

With rapidly increasing rates of contemporary extinction, predicting extinction vulnerability and identifying how multiple stressors drive non-random species loss have become key challenges in ecology. These assessments are crucial for avoiding the loss of key functional groups that sustain ecosystem processes and services. We developed a novel predictive framework of species extinction vulnerability and applied it to coral reef fishes. Although relatively few coral reef fishes are at risk of global extinction from climate disturbances, a negative convex relationship between fish species locally vulnerable to climate change vs. fisheries exploitation indicates that the entire community is vulnerable on the many reefs where both stressors co-occur. Fishes involved in maintaining key ecosystem functions are more at risk from fishing than climate disturbances. This finding is encouraging as local and regional commitment to fisheries management action can maintain reef ecosystem functions pending progress towards the more complex global problem of stabilizing the climate. PMID:21320260

Graham, Nicholas A J; Chabanet, Pascale; Evans, Richard D; Jennings, Simon; Letourneur, Yves; Aaron Macneil, M; McClanahan, Tim R; Ohman, Marcus C; Polunin, Nicholas V C; Wilson, Shaun K

2011-04-01

386

40 CFR 230.44 - Coral reefs.  

Code of Federal Regulations, 2010 CFR

...skeletal deposit, usually of calcareous or silicaceous materials, produced by the vital activities of anthozoan polyps or other invertebrate organisms present in growing portions of the reef. (b) Possible loss of values: The discharge of dredged or fill...

2010-07-01

387

40 CFR 230.44 - Coral reefs.  

Code of Federal Regulations, 2012 CFR

...skeletal deposit, usually of calcareous or silicaceous materials, produced by the vital activities of anthozoan polyps or other invertebrate organisms present in growing portions of the reef. (b) Possible loss of values: The discharge of dredged or fill...

2012-07-01

388

40 CFR 230.44 - Coral reefs.  

Code of Federal Regulations, 2013 CFR

...skeletal deposit, usually of calcareous or silicaceous materials, produced by the vital activities of anthozoan polyps or other invertebrate organisms present in growing portions of the reef. (b) Possible loss of values: The discharge of dredged or fill...

2013-07-01

389

40 CFR 230.44 - Coral reefs.  

Code of Federal Regulations, 2014 CFR

...skeletal deposit, usually of calcareous or silicaceous materials, produced by the vital activities of anthozoan polyps or other invertebrate organisms present in growing portions of the reef. (b) Possible loss of values: The discharge of dredged or fill...

2014-07-01

390

Paleobiologic and paleoenvironmental context of coral-bearing Early Cambrian reefs: Implications for Phanerozoic reef development  

NASA Astrophysics Data System (ADS)

Early Cambrian corals from South Australia have been found within fossil reefs of unusual biological and paleoecological composition. The framework of these reefs is composed of a diverse assemblage of calcareous sponges (e.g., archaeocyaths and sphinctozoans), calci-microbes, and at least two species of coral-like organisms, one of which is first reported herein and bears similarities to younger Paleozoic tabulate corals. Complex growth interactions occur among these organisms, suggesting that space was a limiting factor in Early Cambrian reef ecosystems, as it is today in modern scleractinian reefs. In striking contrast to most Early Cambrian archaeocyath-calcimicrobe reefs, these South Australian reefs flourished within energetic, mixed silici-clastic-carbonate shallow-marine environments along the margins of arid, coarse-grained, sea-marginal alluvial fans. The implications of these coral-bearing reefs are multifold. First, their existence not only extends the range of tabulatelike corals to the Botomian (middle Early Cambrian), but it adds an additional clade of participants to the Early Cambrian metazoan radiation event. Second, the existence of Botomian-aged skeletonized colonial cnidarians necessitates an earliest Cambrian or Neoproterozoic ancestor for the group. Third, the presence of tabulatelike corals and their involvement in reef building prior to the Toyonian extinction (late Early Cambrian) challenges hypotheses (e.g., lack of a suitable reef builder after the extinction of archaeocyaths until the Ordovician) used to explain the paucity of Middle and Late Cambrian reefs worldwide. The presence of these corals on sea-marginal fans contradicts the perception that early reefs were restricted to low-energy, predominantly carbonate subtidal environments.

Savarese, Michael; Mount, Jeffrey F.; E., James; Bucklin, Louis

1993-10-01

391

Comparing the Invasibility of Experimental “Reefs” with Field Observations of Natural Reefs and Artificial Structures  

PubMed Central

Natural systems are increasingly being modified by the addition of artificial habitats which may facilitate invasion. Where invaders are able to disperse from artificial habitats, their impact may spread to surrounding natural communities and therefore it is important to investigate potential factors that reduce or enhance invasibility. We surveyed the distribution of non-indigenous and native invertebrates and algae between artificial habitats and natural reefs in a marine subtidal system. We also deployed sandstone plates as experimental ‘reefs’ and manipulated the orientation, starting assemblage and degree of shading. Invertebrates (non-indigenous and native) appeared to be responding to similar environmental factors (e.g. orientation) and occupied most space on artificial structures and to a lesser extent reef walls. Non-indigenous invertebrates are less successful than native invertebrates on horizontal reefs despite functional similarities. Manipulative experiments revealed that even when non-indigenous invertebrates invade vertical “reefs”, they are unlikely to gain a foothold and never exceed covers of native invertebrates (regardless of space availability). Community ecology suggests that invertebrates will dominate reef walls and algae horizontal reefs due to functional differences, however our surveys revealed that native algae dominate both vertical and horizontal reefs in shallow estuarine systems. Few non-indigenous algae were sampled in the study, however where invasive algal species are present in a system, they may present a threat to reef communities. Our findings suggest that non-indigenous species are less successful at occupying space on reef compared to artificial structures, and manipulations of biotic and abiotic conditions (primarily orientation and to a lesser extent biotic resistance) on experimental “reefs” explained a large portion of this variation, however they could not fully explain the magnitude of differences. PMID:22666459

Dafforn, Katherine A.; Glasby, Tim M.; Johnston, Emma L.

2012-01-01

392

Hurricane Allen's Impact on Jamaican Coral Reefs.  

PubMed

Coral reefs of north Jamaica, normally sheltered, were severely damaged by Hurricane Allen, the strongest Caribbean hurricane of this century. Immediate studies were made at Discovery Bay, where reef populations were already known in some detail. Data are presented to show how damage varied with the position and orientation of the substraturn and with the shape, size, and mechanical properties of exposed organisms. Data collected over succeeding weeks showed striking differences in the ability of organisms to heal and survive. PMID:17744383

Woodley, J D; Chornesky, E A; Clifford, P A; Jackson, J B; Kaufman, L S; Knowlton, N; Lang, J C; Pearson, M P; Porter, J W; Rooney, M C; Rylaarsdam, K W; Tunnicliffe, V J; Wahle, C M; Wulff, J L; Curtis, A S; Dallmeyer, M D; Jupp, B P; Koehl, M A; Neigel, J; Sides, E M

1981-11-13

393

Dynamic fragility of oceanic coral reef ecosystems  

Microsoft Academic Search

As one of the most diverse and productive ecosystems known, and one of the first ecosystems to exhibit major climate-warming impacts (coral bleaching), coral reefs have drawn much scientific attention to what may prove to be their Achilles heel, the thermal sensitivity of reef-building corals. Here we show that climate change-driven loss of live coral, and ultimately structural complexity, in

Nicholas A. J. Graham; Shaun K. Wilson; Simon Jennings; Nicholas V. C. Polunin; Jude P. Bijoux; Jan Robinson

2006-01-01

394

Mineralogy and formation conditions of ores in the Bereznyakovskoe ore field, the Southern Urals, Russia  

NASA Astrophysics Data System (ADS)

The Bereznyakovskoe ore field is situated in the Birgil’da-Tomino ore district of the East Ural volcanic zone. The ore field comprises several centers of hydrothermal mineralization, including the Central Bereznyakovskoe and Southeastern Bereznyakovskoe deposits, which are characterized in this paper. The disseminated and stringer-disseminated orebodies at these deposits are hosted in Upper Devonian-Lower Carboniferous dacitic-andesitic tuff and are accompanied by quartz-sericite hydrothermal alteration. Three ore stages are recognized: early ore (pyrite); main ore (telluride-base-metal, with enargite, fahlore-telluride, and gold telluride substages); and late ore (galena-sphalerite). The early and the main ore stages covered temperature intervals of 320-380 to 180°C and 280-300 to 170°C, respectively; the ore precipitated from fluids with a predominance of NaCl. The mineral zoning of the ore field is expressed in the following change of prevalent mineral assemblages from the Central Bereznyakovskoe deposit toward the Southeastern Bereznyakovskoe deposit: enargite, tennantite, native tellurium, tellurides, and selenides ? tennantite-tetrahedrite, tellurides, and sulfoselenides (galenoclausthalite) ? tetrahedrite, tellurides, native gold, galena, and sphalerite. The established trend of mineral assemblages was controlled by a decrease in f_{S_2 } , f_{Te_2 } and f_{O_2 } and an increase in pH of mineral-forming fluids from early to late assemblages and from the Central Bereznyakovskoe deposit toward the Southeastern Bereznyakovskoe deposit. Thus, the Central Bereznyakovskoe deposit was located in the center of an epithermal high-sulfidation ore-forming system. As follows from widespread enargite and digenite, a high Au/Ag ratio, and Au-Cu specialization of this deposit, it is rather deeply eroded. The ore mineralization at the Southeastern Bereznyakovskoe deposit fits the intermediate- or low-sulfidation type and is distinguished by development of tennantite, a low Au/Ag ratio, and enrichment in base metals against a lowered copper content. In general, the Bereznyakovskoe ore field is a hydrothermal system with a wide spectrum of epithermal mineralization styles.

Plotinskaya, O. Yu.; Groznova, E. O.; Kovalenker, V. A.; Novoselov, K. A.; Seltmann, R.

2009-10-01

395

Vertical distribution and speciation of trace metals in weathering flotation residues of a zinc/lead sulfide mine.  

PubMed

Sulfide-bearing mine tailings are a serious environmental problem around the world. In this study, the vertical distribution and speciation of Zn and Pb in the fine-grained flotation residues of a former sulfide ore mine in Germany were investigated to assess the inorganic weathering processes that effect the environmental risk arising from this site. Total metal contents were determined by X-ray fluorescence spectroscopy (XRF). Mobilizable fractions of Zn, Pb, Fe, and Mn were quantified by sequential chemical extractions (SCE). Furthermore, the speciation of Zn was analyzed by Zn K-edge extended X-ray absorption fine structure spectroscopy (EXAFS) to identify the residual Zn species. The variations in pH and inorganic C content show an acidification of the topsoil to pH 5.5. EXAFS results confirm that Zn is mainly bound in sphalerite in the subsoil and weathering reactions lead to a redistribution of Zn in the topsoil. A loss of 35% Zn and S from the topsoil compared with the parent material with 10 g kg-1 Zn and neutral pH has been observed. If acidification proceeds it will lead to a significant release of Zn, S, and Pb to the ground water. In contrast to Zn, Pb is enriched in the mobile fraction of the topsoil by more than a factor of two compared with the subsoil which contains a total of 2 g kg-1 Pb. Thus, the high bioavailability of Pb and the potential for Pb uptake by plants and animals currently represent the most severe threat for environmental health. PMID:17215213

Schuwirth, Nele; Voegelin, Andreas; Kretzschmar, Ruben; Hofmann, Thilo

2007-01-01

396

Rapid vertical accretion on a `young' shore-detached turbid zone reef: Offshore Paluma Shoals, central Great Barrier Reef, Australia  

NASA Astrophysics Data System (ADS)

We report on the age structure and net accretion rates determined for an open water turbid zone reef, known as Offshore Paluma Shoals, located on the inner central Great Barrier Reef. Twenty-eight radiocarbon dates from 5 cores through the reef structure indicate that this reef began growing ~1,700 years ago and that net vertical accretion through the main phase of reef development was rapid (averaging 7.8 mm yr-1), this despite the reef growing in highly turbid waters. The most rapid growth phases coincided with the accumulation of mud-rich terrigenoclastic sediments within the reef fabric. The study emphasises the capacity of turbid zone reefs to vertically accrete at rates matching or exceeding many clear water reefs despite seemingly detrimental water quality conditions.

Perry, C. T.; Smithers, S. G.; Gulliver, P.

2013-12-01

397

Coral Reef Ecosystems: The Abiotic Setting  

NSDL National Science Digital Library

This Science Object is the second of four Science Objects in the Coral Reef Ecosystems SciPack. It investigates the abiotic characteristics that affect the coral reef ecosystem. The number and kinds of organisms found along each reef depend on the physical conditions of the environment and resources available, including food, light, water quality, temperature, and other organisms living in the reef. If conditions change significantly due to changes in climate, loss of food sources, excessive predation, or loss of habitat, the health and stability of the ecosystem will be affected. Like many complex systems, coral ecosystems tend to have cyclic fluctuations around a state of rough equilibrium. In the long run, if conditions remain reasonably constant a coral ecosystem can be stable for hundreds of years. Learning Outcomes:? Identify the characteristics of an ecosystem, and describe the interdependence between biotic and abiotic features in an ecosystem.? Describe how the following abiotic factors provide coral with the energy needed to survive and grow within their ecosystem: sunlight, water, oxygen, and carbon dioxide.? Describe the optimal environmental conditions for coral reef growth, and explain the process of coral reef development (including the role of available sunlight and calcium).? Explain how the following environmental factors might affect coral ecosystems: increase in dissolved CO2, changes in global temperatures, increase in ocean water turbidity through water pollution.

National Science Teachers Association (NSTA)

2006-11-01

398

ReefSAM - Reef Sedimentary Accretion Model: A new 3D coral reef evolution model/simulator  

NASA Astrophysics Data System (ADS)

Coral reefs show characteristic morphological patterns (e.g. coral dominated margins with detrital carbonate dominated lagoons/back-reef) and temporal development (e.g. Hopley et al. 2007). While the processes which lead to predictable patterns on a range of scales have been discussed qualitatively, a full quantitative understanding of the range of processes and parameters involved requires modelling. Previous attempts to model complex Holocene reef systems (i.e. One Tree Reef, GBR - Barrett and Webster 2012) using a carbonate stratigraphic forward model (Carbonate3D - Warrlich et al. 2002) identified a number of important but unsimulated processes and potential model improvements. ReefSAM has been written from scratch in Matlab using these findings and experiences from using Carbonate3D. It simulates coralgal accretion and carbonate sand production and transport. Specific improvements include: 1. a more complex hydrodynamic model based on wave refraction and incorporating vertical (depth) and lateral (substrate dependent) variations in transport energy and erosion. 2. a complex reef growth model incorporating depth, wave energy/turbidity and substrate composition. 3. Paleo-water depth, paleo-wave energy and bio-zone (combination of paleo-water depth and wave energy) model outputs allowing coralgal habitat changes through time and space to be simulated and compared to observational data. The model is compared to the well studied One Tree Reef - tests similar to those undertaken in Barrett and Webster 2012 with Carbonate3D are presented. Model development coincides with plans for further intensive drilling at One Tree Reef (mid 2013) providing an opportunity to test the model predictively. The model is still in active development. References: Barrett, S.J., Webster, J.M.,2012. Holocene evolution of the Great Barrier Reef: Insights from 3D numerical modelling. Sedimentary Geology 265-266, 56-71. Warrlich, G.M.D., Waltham, D.A., Bosence D.W.J., 2002. Quantifying the sequence stratigraphy and drowning mechanisms of atolls using a new 3-D forward modelling program (CARBONATE 3D). Basin Research 14, 379-400. Hopley, D., Smithers, S.G., Parnell, K.E., 2007. The geomorphology of the Great Barrier Reef. Cambridge.

Barrett, Samuel; Webster, Jody

2013-04-01

399

Monitoring of coral reefs on Ishigaki Island in Japan using multitemporal remote sensing data  

Microsoft Academic Search

In recent years environmental problems in the coral reefs attract both scientific and social attentions. However, most coral reefs have few maps showing the reef topography and the distributions of various benthic habitats in the reef. Satellite remote sensing can be used for coral reef mapping because satellites can observe the reefs scattered in tropical oceans in a short time

Tsuneo Matsunaga; Akira Hoyano; Yosei Mizukami

2001-01-01

400

The indirect electrochemical refining of lunar ores  

NASA Technical Reports Server (NTRS)

Recent work performed on an electrolytic cell is reported which addresses the implicit limitations in various approaches to refining lunar ores. The cell uses an oxygen vacancy conducting stabilized zirconia solid electrolyte to effect separation between a molten salt catholyte compartment where alkali metals are deposited, and an oxygen-evolving anode of composition La(0.89)Sr(0.1)MnO3. The cell configuration is shown and discussed along with a polarization curve and a steady-state current-voltage curve. In a practical cell, cathodically deposited liquid lithium would be continuously removed from the electrolytic cell and used as a valuable reducing agent for ore refining under lunar conditions. Oxygen would be indirectly electrochemically extracted from lunar ores for breathing purposes.

Semkow, Krystyna W.; Sammells, Anthony F.

1987-01-01

401

Internal structure and Holocene evolution of One Tree Reef, southern Great Barrier Reef  

Microsoft Academic Search

Analysis of core from six drill holes and ten vibrocores from One Tree Reef has delineated five major biosedimentological facies: algal pavement, coral head facies, branching coral facies, reef flat rubble facies and sand facies. Holocene growth began around 8,000 years B.P. with a high energy coral head facies on windward margins and a lower energy branching coral facies on

J. F. Marshall; P. J. Davies

1982-01-01

402

Philippine Coral Reefs Under Threat: The Economic Losses Caused by Reef Destruction  

Microsoft Academic Search

In the Philippines, coral reef fisheries provide livelihood for more than a million small-scale fishers who contribute almost US$ 1 billion annually to the country’s economy. The rapidly growing population needs increasing amounts of fish and other marine organisms. However, overfishing, destructive fishing methods and sedimentation have damaged or destroyed many reef areas. Fish catches have fallen well below the

Alan T White; Helge P Vogt; Tijen Arin

2000-01-01

403

Reef corals of Johnston Atoll: one of the world's most isolated reefs  

Microsoft Academic Search

Johnston Atoll lies 800 km southwest of the nearest reefs of Hawaii and over 1,500 km from other shallow reefs to the south and west. Only 33 species and 16 genera and subgenera of shallow water stony corals have been reported from the atoll. Endemic species are absent despite Johnston's great age and favorable environment. With few exceptions, only species

James E. Maragos; Paul L. Jokiel

1986-01-01

404

Reef size and isolation determine the temporal stability of coral reef fish populations.  

PubMed

Temporal variance in species abundance, a potential driver of extinction, is linked to mean abundance through Taylor's power law, the empirical observation of a linear log-log relationship with a slope between 1 and 2 for most species. Here we test the idea that the slope of Taylor's power law can vary both among species and spatially as a function of habitat area and isolation. We used the world's most extensive database of coral reef fish communities comprising a 15-year series of fish abundances on 43 reefs of Australia's Great Barrier Reef. Greater temporal variances were observed at small and isolated reefs, and lower variances at large and connected ones. The combination of reef area and isolation was associated with an even greater effect on temporal variances, indicating strong empirical support for the idea that populations on small and isolated reefs will succumb more frequently to local extinction via higher temporal variability, resulting in lower resilience at the community level. Based on these relationships, we constructed a regional predictive map of the dynamic fragility of coral reef fish assemblages on the Great Barrier Reef. PMID:21141175

Mellin, Camille; Huchery, Cindy; Caley, M Julian; Meekan, Mark G; Bradshaw, Corey J A

2010-11-01

405

Thermogravimetry of a kaolinite-alunite ore  

Microsoft Academic Search

An ore containing kaolinite (Al2O3·2SiO2·2H2O), alunite (KAl3(SO4)2(OH)6), feldspar (KAlSi3O8) and quartz (SiO2) was analysed by TG\\/DTA to determine the mineralogical composition of samples considered representative of concentrates and tailings likely to be obtained from physical treatments designed to produce a kaolin concentrate as low as possible in alunite. The ore was divided into various particle-size fractions each of which was

L. Piga

1995-01-01

406

OVERHEAD VIEW OF MARISCAL WORKS ORE BIN FOUNDATION AND CONDENSERS, ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

OVERHEAD VIEW OF MARISCAL WORKS ORE BIN FOUNDATION AND CONDENSERS, TOWARD WHERE ORE DELIVERY TRACK WOULD HAVE RUN, LOOKING NORTHEAST. - Mariscal Quicksilver Mine & Reduction Works, Terlingua, Brewster County, TX

407

4. VIEW OF RUINS OF FINE ORE MILL (FEATURE 20), ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

4. VIEW OF RUINS OF FINE ORE MILL (FEATURE 20), FACING SOUTHEAST. - Copper Canyon Camp of the International Smelting & Refining Company, Ruins of the Fine Ore Mill, Copper Canyon, Battle Mountain, Lander County, NV

408

1. VIEW TO SOUTH (RETAINING WALL OF ORE RECEIVING PLATFORM ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

1. VIEW TO SOUTH (RETAINING WALL OF ORE RECEIVING PLATFORM TO LEFT). - Vanadium Corporation of America (VCA) Naturita Mill, Sampling Building & Ore Receiving Platform, 3 miles Northwest of Naturita, between Highway 141 & San Miguel River, Naturita, Montrose County, CO

409

4. DETAIL OF ORE RECEIVING PLATFORM AND GRIZZLY, VIEW TO ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

4. DETAIL OF ORE RECEIVING PLATFORM AND GRIZZLY, VIEW TO EAST. - Vanadium Corporation of America (VCA) Naturita Mill, Sampling Building & Ore Receiving Platform, 3 miles Northwest of Naturita, between Highway 141 & San Miguel River, Naturita, Montrose County, CO

410

3. DETAIL OF ORE RECEIVING PLATFORM AND GRIZZLY, VIEW TO ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

3. DETAIL OF ORE RECEIVING PLATFORM AND GRIZZLY, VIEW TO WEST. - Vanadium Corporation of America (VCA) Naturita Mill, Sampling Building & Ore Receiving Platform, 3 miles Northwest of Naturita, between Highway 141 & San Miguel River, Naturita, Montrose County, CO

411

2. VIEW TO NORTHEAST (ORE RECEIVING PLATFORM OUT OF VIEW ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

2. VIEW TO NORTHEAST (ORE RECEIVING PLATFORM OUT OF VIEW TO RIGHT). - Vanadium Corporation of America (VCA) Naturita Mill, Sampling Building & Ore Receiving Platform, 3 miles Northwest of Naturita, between Highway 141 & San Miguel River, Naturita, Montrose County, CO

412

AERIAL OVERVIEW, LOOKING NORTH, WITH FORMER TCIUS STEEL ORE MINE ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

AERIAL OVERVIEW, LOOKING NORTH, WITH FORMER TCI-US STEEL ORE MINE HEADQUARTERS (BOTTOM) AND SUPERINTENDENT'S AND FOREMAN HOUSING ALONG MINNESOTA AVENUE AT CREST OF RED MOUNTAIN (TOP LEFT). - Muscoda Red Ore Mining Community, Bessemer, Jefferson County, AL

413

AERIAL VIEW FACING EAST, LOOKING DOWN CENTER OF ORE YARD. ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

AERIAL VIEW FACING EAST, LOOKING DOWN CENTER OF ORE YARD. OIL TANKS IN FOREGROUND, ORE BRIDGE & SINTERING CONVEYOR IN CENTER, & COKE PLANT IN BACKGROUND. - Pittsburgh Steel Company, Monessen Works, Donner Avenue, Monessen, Westmoreland County, PA

414

CONTEXT VIEW ACROSS ORE YARD AT MODERN SELFUNLOADING SHIP UNLOADING ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

CONTEXT VIEW ACROSS ORE YARD AT MODERN SELF-UNLOADING SHIP UNLOADING IN FRONT OF HULETTS. LOOKING SOUTHWEST. - Pennsylvania Railway Ore Dock, Lake Erie at Whiskey Island, approximately 1.5 miles west of Public Square, Cleveland, Cuyahoga County, OH

415

CONTEXT VIEW ACROSS ORE YARD AT MODERN SELFUNLOADING BOOM IN ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

CONTEXT VIEW ACROSS ORE YARD AT MODERN SELF-UNLOADING BOOM IN FRONT OF HULETTS. LOOKING SOUTHWEST. - Pennsylvania Railway Ore Dock, Lake Erie at Whiskey Island, approximately 1.5 miles west of Public Square, Cleveland, Cuyahoga County, OH

416

24. OVERHEAD VIEW OF MARISCAL WORKS ORE BIN FOUNDATION AND ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

24. OVERHEAD VIEW OF MARISCAL WORKS ORE BIN FOUNDATION AND CONDENSERS, TOWARD WHERE ORE DELIVERY TRACK WOULD HAVE RUN, LOOKING NORTHEAST. - Mariscal Quicksilver Mine & Reduction Works, Terlingua, Brewster County, TX

417

Anglesite and silver recovery from jarosite residues through roasting and sulfidization-flotation in zinc hydrometallurgy.  

PubMed

Hazardous jarosite residues contain abundant valuable minerals that are difficult to be recovered by traditional flotation process. This study presents a new route, roasting combined with sulfidization-flotation, for the recovery of anglesite and silver from jarosite residues of zinc hydrometallurgy. Surface appearance and elemental distribution of jarosite residues was examined by scanning electron microscopy and energy dispersive X-ray spectrometry analysis, respectively. Decomposition and transformation mechanisms of jarosite residues were illustrated by differential thermal analysis. Results showed that after roasting combined with flotation, the grade and recovery of lead were 43.89% and 66.86%, respectively, and those of silver were 1.3 kg/t and 81.60%, respectively. At 600-700 °C, jarosite was decomposed to release encapsulated valuable minerals such as anglesite (PbSO4) and silver mineral; silver jarosite decomposed into silver sulfate (Ag2SO4); and zinc ferrite (ZnO · Fe2O3) decomposed into zinc sulfate (ZnSO4) and hematite (Fe2O3). Bared anglesite and silver minerals were modified by sodium sulfide and easily collected by flotation collectors. This study demonstrates that the combination of roasting and sulfidization-flotation provides a promising process for the recovery of zinc, lead, and silver from jarosite residues of zinc hydrometallurgy. PMID:24953935

Han, Haisheng; Sun, Wei; Hu, Yuehua; Jia, Baoliang; Tang, Honghu

2014-08-15

418

Flotation and flocculation chemistry of coal and oxidized coals  

SciTech Connect

This project is designed to develop an understanding of the fundamentals involved in flotation and flocculation of coal, and of coal in various states of oxidation. The main objective of this study is to accurately characterize the coal surface and elucidate mechanisms by which surface interactions between coal and various reagents enhance beneficiation of coals. Effects of oxidation on the modification of surface characteristics of coal by various reagents will also be studied. This quarter, the following studies were conducted in order to further develop our understanding of the role of heterogeneity in interfacial phenomena. (1) Since surface characterization is an important aspect in this project, ESCA (Electron Spectroscopy for Chemical Analysis) study of the coal surface was conducted. Surface derivatization, a technique often used in the preparation of organic compounds for gas-liquid chromatography, uses site specific molecular tags'' that bond to key chemical groups on the surface. Application of derivatization in conjunction with ESCA is a relatively new technique for quantifying functional groups on the surface which has not been possible till now. (2) A distribution of contact angles on the surface of coal (pseudo theta map) is presented based on our earlier results and other published information. The role of heterogeneity in contact angle studies is also examined. 14 refs., 2 tabs.

Somasundaran, P.; Ramesh, R.

1989-01-01

419

Sun Compass Orientation Helps Coral Reef Fish Larvae Return to Their Natal Reef  

PubMed Central

Reef fish sustain populations on isolated reefs and show genetic diversity between nearby reefs even though larvae of many species are swept away from the natal site during pelagic dispersal. Retention or recruitment to natal reefs requires orientation capabilities that enable larvae to find their way. Although olfactory and acoustically based orientation has been implicated in homing when larvae are in the reef’s vicinity, it is still unclear how they cope with greater distances. Here we show evidence for a sun compass mechanism that can bring the larvae to the vicinity of their natal reef. In a circular arena, pre-settlement larvae and early settlers (<24 hours) of the cardinal fish, Ostorhinchus doederleini, showed a strong SSE directional swimming response, which most likely has evolved to compensate for the locally prevailing large scale NNW current drift. When fish were clock-shifted 6 hours, they changed their orientation by ca. 180° as predicted by the tropical sun curve at One Tree Island, i.e. they used a time-compensated sun compass. Furthermore, the fish oriented most consistently at times of the day when the sun azimuth is easy to determine. Microsatellite markers showed that the larvae that had just arrived at One Tree Island genetically belonged to either the local reef population or to Fitzroy Reef located 12 kilometers to the SSE. The use of a sun compass adds a missing long-distance link to the hierarchy of other sensory abilities that can direct larvae to the region of origin, including their natal reef. Predominant local recruitment, in turn, can contribute to genetic isolation and potential speciation. PMID:23840396

Mouritsen, Henrik; Atema, Jelle; Kingsford, Michael J.; Gerlach, Gabriele

2013-01-01

420

Reef Odor: A Wake Up Call for Navigation in Reef Fish Larvae  

PubMed Central

The behavior of reef fish larvae, equipped with a complex toolbox of sensory apparatus, has become a central issue in understanding their transport in the ocean. In this study pelagic reef fish larvae were monitored using an unmanned open-ocean tracking device, the drifting in-situ chamber (DISC), deployed sequentially in oceanic waters and in reef-born odor plumes propagating offshore with the ebb flow. A total of 83 larvae of two taxonomic groups of the families Pomacentridae and Apogonidae were observed in the two water masses around One Tree Island, southern Great Barrier Reef. The study provides the first in-situ evidence that pelagic reef fish larvae discriminate reef odor and respond by changing their swimming speed and direction. It concludes that reef fish larvae smell the presence of coral reefs from several kilometers offshore and this odor is a primary component of their navigational system and activates other directional sensory cues. The two families expressed differences in their response that could be adapted to maintain a position close to the reef. In particular, damselfish larvae embedded in the odor plume detected the location of the reef crest and swam westward and parallel to shore on both sides of the island. This study underlines the critical importance of in situ Lagrangian observations to provide unique information on larval fish behavioral decisions. From an ecological perspective the central role of olfactory signals in marine population connectivity raises concerns about the effects of pollution and acidification of oceans, which can alter chemical cues and olfactory responses. PMID:24015278

Paris, Claire B.; Kingsford, Michael; Gerlach, Gabriele; Guigand, Cedric M.

2013-01-01

421

32. INTERIOR VIEW LOOKING NORTH ON THE ORE BREAKER LEVEL. ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

32. INTERIOR VIEW LOOKING NORTH ON THE ORE BREAKER LEVEL. THE ORE BREAKER, A BLAKE JAW CRUSHER, IS IN THE BOX IN THE LEFT OF THE PHOTOGRAPH, THE ORE TO BE BROKEN IS FED INTO THE OPENING ON THE FLOOR AND NEXT TO ORE BREAKER BOX. THE GRIZZLY BARS ARE ON THE RIGHT AND THE PULLEYS FROM THE POWER SYSTEM ARE OVERHEAD. - Standard Gold Mill, East of Bodie Creek, Northeast of Bodie, Bodie, Mono County, CA

422

The flotation of metallic arsenic as a function of pH and pulp potential — A single mineral study  

Microsoft Academic Search

Arsenic is a penalty element in base metal gravity and flotation concentrates and during beneficiation efforts are often made to reduce its level in concentrates destined for smelting. In some Australian tin and tantalum circuits this arsenic can occur as elemental arsenic, lollingite, or arsenopyrite. A great deal is known about the flotation of arsenopyrite, but little is known about

W. J. Bruckard; I. Kyriakidis; J. T. Woodcock

2007-01-01

423

CONTEXT VIEW ALONG EXISTING PERIMETER TRACKS LOOKING OVER IRON ORE ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

CONTEXT VIEW ALONG EXISTING PERIMETER TRACKS LOOKING OVER IRON ORE CARS TOWARDS WESTERN SIDE OF CLEVELAND BULK TERMINAL BUILDINGS AND A SELF-UNLOADING IRON ORE SHIP AT DOCK. LOOKING SOUTHWEST. - Pennsylvania Railway Ore Dock, Lake Erie at Whiskey Island, approximately 1.5 miles west of Public Square, Cleveland, Cuyahoga County, OH

424

17. ORE DOCK, LOOKING EAST FROM HULETT NO. 1. WHEN ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

17. ORE DOCK, LOOKING EAST FROM HULETT NO. 1. WHEN BUILT IN 1911-1912, THIS WAS THE LARGEST ORE-UNLOADING DOCK ON THE GREAT LAKES. - Pennsylvania Railway Ore Dock, Lake Erie at Whiskey Island, approximately 1.5 miles west of Public Square, Cleveland, Cuyahoga County, OH

425

3. EAGLE MILL, DETAIL OF CRUDE ORE BIN FROM NORTH, ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

3. EAGLE MILL, DETAIL OF CRUDE ORE BIN FROM NORTH, c. 1908-10. SHOWS EXPOSED CRUSHER HOUSE IN FRONT OF (SOUTH) CRUDE ORE BIN AND SNOW SHED ADDED OVER TRAM TRACKS. NOTE LACK OF EAST OR WEST CRUDE ORE BINS. CREDIT JW. - Bald Mountain Gold Mill, Nevada Gulch at head of False Bottom Creek, Lead, Lawrence County, SD

426

29. ORE DOCK, LOOKING WEST; AT WORK UNLOADING THE 'GEORGE ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

29. ORE DOCK, LOOKING WEST; AT WORK UNLOADING THE 'GEORGE M. HUMPHREY'S' CARGO OF 25,000. TONS OF ORE. - Pennsylvania Railway Ore Dock, Lake Erie at Whiskey Island, approximately 1.5 miles west of Public Square, Cleveland, Cuyahoga County, OH

427

6. Looking west showing top of dock: steaming frozen ore ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

6. Looking west showing top of dock: steaming frozen ore which had been put in pockets in December 1959, May 6, 1990. Photographer: unknown - Marquette Ore Dock No. 6, Ore Dock, On pilings in Marquette City Lower Harbor, Marquette, Marquette County, MI

428

18. VIEW OF CRUDE ORE BINS FROM WEST. WEST CRUDE ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

18. VIEW OF CRUDE ORE BINS FROM WEST. WEST CRUDE ORE BIN AND TRESTLE FROM TWO JOHNS TRAMLINE TO SOUTH, CRUDE ORE BIN IN FOREGROUND. MACHINE SHOP IN BACKGROUND. THE TRAM TO PORTLAND PASSED TO NORTH OF MACHINE SHOP. - Bald Mountain Gold Mill, Nevada Gulch at head of False Bottom Creek, Lead, Lawrence County, SD

429

12. Photo copy of drawing, May 5, 1930. PENFIELD REEF ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

12. Photo copy of drawing, May 5, 1930. PENFIELD REEF L/S MODERNIZATION. Drawing no. NY-1393, U.S. Coast GUard Civil Engineering Unit, Warwick, Rhode Island. - Penfield Reef Lighthouse, Long Island Sound, Bridgeport, Fairfield County, CT

430

Recent and relict topography of Boo Bee patch reef, Belize  

USGS Publications Warehouse

Five core borings were taken on and around Boo Bee Patch Reef to better understand the origin of such shelf lagoon reefs. The cores reveal 4 stages of development: (1) subaerial exposure of a Pleistocene "high" having about 8 meters of relief, possibly a Pleistocene patch reef; (2) deposition of peat and impermeable terrigenous clay 3 meters thick around the high; (3) initiation of carbonate sediment production by corals and algae on the remaining 5 meters of hard Pleistocene topography and carbonate mud on the surrounding terrigenous clay; and (4) accelerated organic accumulation on the patch reef. Estimates of patch reef sedimentation rates (1.6 m/1000 years) are 3 to 4 times greater than off-reef sedimentation rates (0.4-0.5 m/1000 years). During periods of Pleistocene sedimentation on the Belize shelf, lagoon patch reefs may have grown above one another, stacking up to form reef accumulation of considerable thickness.

Halley, R.B.; Shinn, E.A.; Hudson, J.H.; Lidz, B.

1977-01-01

431

Coral reef formation theory may apply to oil, gas exploration  

SciTech Connect

This paper reports a coral reef formation theory that has implications for hydrocarbon exploration. The theory states that many coral reefs and carbonate buildups from at and are dependent upon nutrient rich fluids seeping through the seabed.

Not Available

1990-12-10

432

A Quick Guide to Southeast Florida's Coral Reefs  

E-print Network

and reproduce. Reefs provide safe havens for spectacular forms of marine life. Unfortunately, reefs dredging, beach nourishment, coastal construction, vessel groundings and injuries from pipelines, cables, anchors, chains and marine debris. Overfishing has disrupted food webs and has been implicated

433

Checklist of Fishes from Madagascar Reef, Campeche Bank, México  

PubMed Central

Abstract This study presents the first list of fish species from Madagascar Reef, Campeche Bank, Gulf of México. Field surveys and literature review identified 54 species belonging to 8 orders, 30 families and 43 genera, comprising both conspicuous and cryptic fishes. Species richness was lower at this reef site compared to reefs in the Mexican Caribbean, Veracruz or Tuxpan, but was similar to other reefs in the same region. Species composition was a mixture of species present in all the reef systems of the Mexican Atlantic. Hypoplectrus ecosur was recorded here for the first time in the Gulf of Mexico, Mycteroperca microlepis, Equetus lanceolatus and Chaetodipterus faber were new records for the reefs of the Campeche Bank, Elacatinus xanthiprora was recorded for the second time in Mexico and expanded its known distribution westwards from Alacranes Reef and Sanopus reticulatus, endemic of the Yucatan state, was recorded here for the first time on a reef. PMID:24891834

2014-01-01

434

The National Oceanic and Atmospheric Administrations Coral Reef Conservation Program  

NSDL National Science Digital Library

This NOAA program supports effective management and sound science to preserve, sustain and restore valuable coral reef ecosystems. Students can read about the U.S. Coral Reef Task Force, learn more about local and national coral reef action strategies, and find links to more information on coral reefs. The site also offers a search for publications and data and a general search of the site.

2007-12-12

435

Hydrodynamic Regimes Affect Coral Reef Resilience to Ocean Acidification  

NASA Astrophysics Data System (ADS)

Caribbean reefs hold tremendous value as sources of food, income, coastal protection, in addition to their cultural significance. Recently, studies showed that Caribbean reef growth has been surpassed in places by excessive rates of erosion due to climate change. The rates of coral reef response to ocean pH changes and warming and the implications for ecosystem resilience remain largely unknown. One way to investigate the potential structural resilience of reefs to climate change is to measure the physical oceanographic conditions in the area. Determining the hydrodynamic regimes and residence time of water in a particular reef environment is crucial to understanding the rates of future warming and acidification a reef site would experience. Our work on Pacific Islands' hydrodynamics - Central Equatorial Pacific, Great Barrier Reef, and Western Pacific -- would be of interest to Caribbean physical oceanographers and coral reef scientists. We use a combination of Acoustic Doppler Current Profilers, Acoustic Doppler Velocimeters, temperature and salinity sensors, and pressure sensors to characterize reef hydrodynamic regimes. Our work indicates that shallower, more protected reef habitats are characterized by longer residence times, their biological signals are strongly tidally modulated, essentially subjecting such habitats to higher rates of warming and acidification in the future. Reef crest environments and fore reef habitats, on the other hand, are well-mixed with open-ocean water. The hydrodynamic regimes there condition such reef sites to more attenuated temperature and pH ranges, conditions more typical of the open ocean. Our work suggests that investigating the geomorphology and resulting localized hydrodynamics in a reef area can provide insights into the relative rates at which a reef could resist or succumb to impacts of ocean acidification. Such information for different reef islands, in the Pacific or Caribbean basins, could provide helpful insights into predictions for economic losses to coastal communities due to climate change.

Teneva, L. T.; Dunbar, R. B.; Koseff, J. R.; Fleischfresser, J. D.; Koweek, D.

2013-05-01

436

Metalliferous black shales and related ore deposits  

SciTech Connect

This book comprises papers and extended abstracts dealing with a variety of topics including the geochemistry and organic geochemistry of several black shale formations: the nature of modern Black Sea sediments: metal- organic complexes in ore fluids; black shales related to disseminated gold deposits; vanadium concentrations and molybdenum-nickel deposits; and the problem of defining metalliferous black shales.

Grauch, R.I. (Geological Survey, Reston, VA (United States)); Huyck, H.L.O. (Cincinnati Univ., OH (United States))

1990-01-01

437

Improving Efficiency in Iron Ore Mining Facilities  

Microsoft Academic Search

A cost effective energy optimization project for a 35 MW iron ore pellet plant is presented. Applications involving large centrifugal loads and changing flow rates were prime targets for significant energy savings. Input-output power balances of these units provide significant data to energy improvement possibilities. On site high power fans (representing 35% of plant load) feature long annual operating times,

Eduardo P. Wiechmann; Pablo E. Aqueveque; Anibal S. Morales

2008-01-01

438

Production of uranium ore in capitalist countries  

Microsoft Academic Search

The uranium deposits of the USA are concentrated in the sedimentary rocks of the Colorado plateau [2, 12]. The ore bodies are adapted to arkosic sandstones, conglomerates, limestones, and argillites. The reserves are distributed into a rather small number of large deposits and a large number of small deposits. Large deposits, each with reserves of from 50 to 100 thousand

N. I. Chesnokov; V. G. Ivanov

1973-01-01

439

Density comparisons of silicon samples by the pressure-of-flotation method at PTB  

NASA Astrophysics Data System (ADS)

After a short review of the history of the flotation method, the flotation apparatus of the Physikalisch-Technische Bundesanstalt (PTB) and the measurement procedures are described in detail. A comprehensive description of the method used to achieve flotation by adjusting the hydrostatic pressure in the liquid is given, covering the heating by compression, surface effects and a calculation of the theoretical detection limit. Data evaluation of the single measurement is described as well as the least-squares fit for a group of samples using Lagrange multipliers to take constraints into account. Results of comparisons of density standards and samples measured to determine the molar volume of silicon and the Avogadro constant including the uncertainty budget and correlation coefficients are reported.

Bettin, H.; Toth, H.

2004-04-01

440

Exploring Drowned Reefs on Gardner Pinnacles  

NASA Astrophysics Data System (ADS)

Gardner Pinnacles (GP), located in the Northwest Hawaiian Islands within Papah?naumoku?kea Marine National Monument, is one of the largest volcanic structures in the entire Hawaiian-Emperor chain. In Oct. 2011, the R/V Ka'imikai-o-Kanaloa mapped and the Pisces IV submersible explored the GP during 7 dives, mainly on drowned reef terraces. New multibeam bathymetric data from the cruise, combined with pre-existing multibeam data mostly collected during transits across the structure, show at least 4 separate volcanoes partially surrounded by several Miocene to Pleistocene drowned coral reefs with extensive lagoons, with the largest volcano surmounted by an active carbonate platform. Large landslides modify the flanks, and the eastern flank is incised by submarine canyons. Seven submersible dives explored and sampled mainly the drowned reef structures. The largest reef complex is on the NW flank above the main break-in-slope, and is a barrier reef surrounding extensive lagoon deposits with complex channel structures. Similar wide lagoons with deep channels parallel to the outer reef terraces are present elsewhere on GP, but unusual elsewhere in the Hawaiian Islands. Seven corals, coralline algae, and echinoid spines from dive P4-266 on that NW edge of GP from 1268-1637 m depth yield a tight age cluster based on Sr-isotopes calibrated to seawater that range from 15.51 to 15.98 Ma, and average 15.76 Ma. Five ages of echinoid spines, mollusk shells, and large foraminfers from dive P4-255 on the SW edge of GP from 1538-1558 m depth range from 14.88 to 15.10 Ma, and average 14.98 Ma. Three ages of corals and coralline algae from dive P4-253 on the SE edge of GP at 1955 m depth range from 12.35 and 12.7 Ma, and average 12.57 Ma. The ages of these reefs indicate when volcanic activity waned and reef deposits could accumulate without constant burial by lava flows; the nearly 3.2 Ma range in reef ages from the flanks of GP suggest that volcanic activity at GP spanned a similar time period. The NW barrier reef is a 310-m-tall ridge surmounted by 140-m pinnacles, consistent with rapid upward growth during the Middle Miocene Climatic Optimum. With two exceptions, all carbonate samples collected from <910 m and a few from deeper terraces, yielded Pleistocene or younger ages. The Pleistocene aged samples on such deep reefs suggest extensive downslope transport of reef debris. Lava samples collected during the dives include tholeiitic shield-stage lavas and several rounded postshield-stage hawaiite cobbles in volcanic/carbonate beach sandstone. Published K-Ar age of volcanic rocks from GP of 12.3±1.0 Ma (Garcia et al., 1987) is inconsistent with the older ages of the overlying reefs. New Ar-Ar age data of samples from the dive program will be presented.

Clague, D. A.; Paduan, J. B.; Braga, J. C.; Humphrey, C.; Hinestrosa, G.; Fullagar, P. D.

2012-12-01

441

The design and application of the ore pulp water treatment in pipeline transport of refined iron ore  

Microsoft Academic Search

The water treatment in conduits, which delivers the ore pulp for a long distance, is a problem that can affect the industries of solid material conduit delivering, due to the special physical characteristics of the ore pulp slurry. The running conduits of Yunnan DaHongshan ore of iron refined is the one of the most running difficult conduits in the world,

Pu Guangyue; Wu Jiande; An Jian; Wang Jian; Ba Haibo; Wang Xiaodong

2010-01-01

442

59 FR- Reef Fish Fishery of the Gulf of Mexico  

Federal Register 2010, 2011, 2012, 2013, 2014

...0648-AE58 Reef Fish Fishery of the Gulf of Mexico AGENCY: National Marine Fisheries...the Reef Fish Resources of the Gulf of Mexico (FMP) and to make other changes...additional participants in the Gulf of Mexico reef fish fishery who may use...

1994-01-07

443

EFFECTS OF DRILLING FLUIDS ON REEF CORALS: A REVIEW  

EPA Science Inventory

This chapter reviews research on the effects of drilling mud on coral reef communities, concentrating on the major reef fauna: the reef-building or hermatypic corals. Drilling mud is an effluent introduced to the marine environment in large quantities during the typical offshore ...

444

FINAL REPORT to the Great Barrier Reef Marine Park Authority  

E-print Network

FINAL REPORT to the Great Barrier Reef Marine Park Authority Seasonal distribution of the dugong in the southern Great Barrier Reef Marine Park. Helene Marsh and Helen Penrose #12;i Table of Contents Executive Sandy Strait DPA. 38 39 #12;1 Seasonal distribution of the dugong in the southern Great Barrier Reef

Marsh, Helene

445

Managing the Great Barrier Reef World Heritage Area  

E-print Network

SESSION 7 Managing the Great Barrier Reef World Heritage Area Chair: Ian McPhail Rapporteur: Helene (abstract only) The changing roles of aboriginal people in the management of the Great Barrier Reef. Noel Pearson and A Leibler- (presented by A Tanner, abstract only) State of the Great Barrier Reef World

Marsh, Helene

446

Impact of micropredatory gnathiid isopods on young coral reef fishes  

E-print Network

for the hypothesis that reef-based A. polyacanthus juveniles are better adapted to gnathiid attack than fishREPORT Impact of micropredatory gnathiid isopods on young coral reef fishes A. S. Grutter Ă? J. L-history stages of coral reef fish, and whether this varies between fish with and without a pelagic phase

Grutter, Alexandra "Lexa"

447

Report Evaluates Importance of Coral Reefs and Mangroves  

Microsoft Academic Search

Thirty percent of the world's coral reefs are seriously damaged, and possibly no pristine reefs remain, according to a 24 January report by the World Conservation Monitoring Centre of the United Nations Environment Programme (UNEP) issued in the wake of the 26 December 2004 Indian Ocean tsunami. ``The Indian Ocean tsunami brought a lot of attention to coral reefs and

Mohi Kumar

2006-01-01

448

Experimental Assessment of Coral Reef Rehabilitation Following Blast Fishing  

Microsoft Academic Search

Illegal fishing with explosives has damaged coral reefs throughout Southeast Asia. In addition to killing fish and other organisms, the blasts shatter coral skeletons, leaving fields of broken rubble that shift in the current, abrading or burying new coral recruits, and thereby slowing or preventing reef recovery. Successful restoration and rehabilitation efforts can contribute to coral reef conservation. We used

HELEN E. FOX; PETER J. MOUS; JOS S. PET; ANDREAS H. MULJADI; ROY L. CALDWELL

2005-01-01

449

CARBON TURNOVER AND ACCUMULu..TION BY CORAL REEFS  

E-print Network

CARBON TURNOVER AND ACCUMULu..TION BY CORAL REEFS A DISSERTATION SUBMITTED TO THE GRADUATE GIVIS the other sites. There is great operational unifor~ity in coral reef metabolism apparentiy re- gardless ism is great, probably at all latitudes at which coral reefs are found. Unperturbed systems

Luther, Douglas S.

450

Explore Online: Question-Driven Coral-Reef Monitoring  

E-print Network

Explore Online: Question-Driven Coral-Reef Monitoring Agriculture and Greenhouse Gas Emissions / Vol. 63 No. 4 · BioScience 297 Progress and Perspectives on Question-Driven Coral-Reef Monitoring Peter Houk and robert van Woesik Despite a steady growth in coral-reef monitoring efforts

Mcilwain, Jenny

451

-Congressional Policy Brief -United States Coral Reef Task Force  

E-print Network

- Congressional Policy Brief - United States Coral Reef Task Force "NOAA, on behalf of the Department of Commerce, is honored to serve as Co-Chair of the U.S. Coral Reef Task Force, along and better understand our nation's valuable coral reef ecosystems." - Tim Keeney Deputy Assistant Secretary

452

Coral Reefs Under Rapid Climate Change and Ocean Acidification  

E-print Network

Coral Reefs Under Rapid Climate Change and Ocean Acidification O. Hoegh-Guldberg,1 * P. J. Mumby,2 carbonate accretion, with corals becoming increasingly rare on reef systems. The result will be less diverse, coral reefs have continued to deteriorate as a result of human in- fluences (3, 4). Rapid increases

Schweik, Charles M.

453

Climate Change, Human Impacts, and the Resilience of Coral Reefs  

E-print Network

Climate Change, Human Impacts, and the Resilience of Coral Reefs T. P. Hughes,1 * A. H. Baird,1 D. Rosen,13 J. Roughgarden14 The diversity, frequency, and scale of human impacts on coral reefs and temperature over the next 50 years exceed the conditions under which coral reefs have flourished over the past

Kleypas, Joanie

454

Watersheds and Coral Reefs: Conservation Science, Policy, and Implementation  

Microsoft Academic Search

Coral reefs worldwide are being degraded by human-induced disturbances, resulting in ecological, economic, and cultural losses. Runoff and sedimentation are among the greatest threats to the coastal reefs surrounding high islands and adjacent to continental landmasses. Existing scientific data identify the key stressors, synergisms, and outcomes at the coral reef ecosystem, community, and population levels. These data demonstrate that marine

ROBERT H. RICHMOND; TEINA RONGO; YIMNANG GOLBUU; STEVEN VICTOR; NOAH IDECHONG; GERRY DAVIS; WILLY KOSTKA; LEINSON NETH; MICHAEL HAMNETT; ERIC WOLANSKI

2007-01-01

455

Well-point sampling of reef interstitial water  

Microsoft Academic Search

A technique is described for collecting reef interstitial water using manually-driven well points. This method does not require the use of hydraulic drills, and eliminates the problems associated with the casing of boreholes. The technique allows collection of samples from discrete depths within reef frameworks, and produces samples unaffected by atmospheric or surface seawater contamination. Data from Checker Reef, Oahu,

Francis J. Sansone; Christine C. Andrews; Robert W. Buddemeier; Gordon W. Tribble

1988-01-01

456

The Diversity of Coral Reefs: What Are We Missing?  

Microsoft Academic Search

Tropical reefs shelter one quarter to one third of all marine species but one third of the coral species that construct reefs are now at risk of extinction. Because traditional methods for assessing reef diversity are extremely time consuming, taxonomic expertise for many groups is lacking, and marine organisms are thought to be less vulnerable to extinction, most discussions of

Laetitia Plaisance; M. Julian Caley; Russell E. Brainard; Nancy Knowlton; Peter Roopnarine

2011-01-01

457

Direct evaluation of macroalgal removal by herbivorous coral reef fishes  

Microsoft Academic Search

Few studies have examined the relative functional impacts of individual herbivorous fish species on coral reef ecosystem processes in the Indo-Pacific. This study assessed the potential grazing impact of individual species within an inshore herbivorous reef fish assemblage on the central Great Barrier Reef (GBR), by determining which fish species were able to remove particular macroalgal species. Transplanted multiple-choice algal

C. S. Mantyka; D. R. Bellwood

2007-01-01

458

Cementation of Upper Miocene reefs in western Mediterranean  

Microsoft Academic Search

Coral reefs in the western Mediterranean (southeast Spain, Balearic Island, northern Morocco, Sicily, and Italy) show a wide variety of cement types, ranging from completely tight, well-cemented, to poorly cemented reefs with most of the primary porosity still preserved. Cementation processes in those coral reefs appear to be controlled to a great extent by repeated changes of relative sea levels

M. Esteban; F. Calvet

1983-01-01

459

Refining of fossil resin flotation concentrate from western coal. Final report  

SciTech Connect

During the past several years, significant research efforts have been made to develop process technology for the selective flotation of fossil resin from western coals. As a result of these efforts, several new flotation technologies have been developed. Operation of a proof-of-concept continuous flotation circuit showed the selective flotation process to be sufficiently profitable to justify the development of a fossil resin industry. However, little attention has been given to the refining of the fossil resin flotation concentrate although solvent refining is a critical step for the fossil resin to become a marketable product. In view of this situation, DOE funded this two-year project to evaluate the following aspects of the fossil resin refining technology: 1) Characterization of the fossil resin flotation concentrate and its refined products; 2) Kinetics of fossil resin extraction; 3) Effects of operating variables on solvent extraction; 4) Extraction solvents; 5) Proof-of-concept continuous refining tests; and 6) Technical and economic analysis. The results from this research effort have led to the following conclusions: Hexane- or heptane-refined fossil resin has a light-yellow color, a melting point of 140 - 142{degrees}C, a density of 1.034 gram/cm, and good solubility in nonpolar solvents. Among the four solvents evaluated (hexane, heptane, toluene and ethyl acetate), hexane is the most appropriate solvent based on overall technical and economic considerations. Batch extraction tests and kinetic studies suggest that the main interaction between the resin and the solvent is expected to be the forces associated with solvation phenomena. Temperature has the most significant effect on extraction rate. With hexane as the solvent, a recovery of 90% cam be achieved at 50{degrees}C and 10% solids concentration with moderate agitation for 1 hour.

Jensen, G.F.; Miller, J.D.

1995-02-16

460

Coal froth flotation: effects of reagent adsorption on the froth structure  

SciTech Connect

The amount and quality of concentrate obtained from froth flotation of a coal are very important to determine the efficiency of the separation process. The shape and size of the bubbles in the froth directly affect the amount and purity of the concentrate overflowed during the froth flotation of the coal. The froth structure is significantly dependent on parameters such as the size of the solid particles, the surface properties of the particles, the chemical structure of surface active agents, the reagents adsorbed onto solid particles, and the reagents remaining in water. This work was performed to determine the relationship between the reagents adsorbed on the solid particles, froth structure, and froth flotation performance. The -53 {mu}m size fraction of a bituminous coal was used to perform froth flotation experiments. The froth flotation of the coal used was performed in the presence of two nonionic surfactants, Triton x-100 (poly(ethylene glycol) tert-octylphenyl ether) and MIBC (methyl isobutyl carbinol), and an anionic surfactant, SDS (sodium dodecyl sulfate). The results showed that the adsorption of a high amount of reagent on the particles decreased the ability of separation, thus a substantial amount of mineral particles overflowed along with the hydrophobic coal particles. The use of MIBC with Triton x-100 or SDS as mixture increased solid recovery, and it was concluded that MIBC selectively adsorbed on solids acting as collector as well as a frother. Reagent adsorption has a crucial effect on the froth structure, which is strongly related to flotation performance. 33 refs., 18 figs.

Meryem Ozmak; Zeki Aktas [Ankara University, Ankara (Turkey). Faculty of Engineering, Department of Chemical Engineering

2006-05-15

461

Effectiveness of benthic foraminiferal and coral assemblages as water quality indicators on inshore reefs of the Great Barrier Reef, Australia  

Microsoft Academic Search

Although the debate about coral reef decline focuses on global disturbances (e.g., increasing temperatures and acidification), local stressors (nutrient runoff and overfishing) continue to affect reef health and resilience. The effectiveness of foraminiferal\\u000a and hard-coral assemblages as indicators of changes in water quality was assessed on 27 inshore reefs along the Great Barrier\\u000a Reef. Environmental variables (i.e., several water quality

S. Uthicke; A. Thompson; B. Schaffelke

2010-01-01

462

13. ORE DOCK, LOOKING EAST FROM HULETT NO. 1. WHEN ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

13. ORE DOCK, LOOKING EAST FROM HULETT NO. 1. WHEN BUILT IN 1911-1912, THIS WAS THE LARGEST ORE-UNLOADING DOCK ON THE GREAT LAKES. THE DOCK FEATURED FOUR HULETT UNLOADERS, EACH WITH A BUCKET CAPACITY OF 17 TONS; A 15-TON CAPACITY ORE STOCKING AND REHANDLING BRIDGE; AND A ONE-MILLION-TON CAPACITY ORE STORAGE YARD. THE WILLIAM-SEAVER-MORGAN COMPANY OF CLEVELAND BUILT THE DOCK EQUIPMENT. - Pennsylvania Railway Ore Dock, Lake Erie at Whiskey Island, approximately 1.5 miles west of Public Square, Cleveland, Cuyahoga County, OH

463

An approach to mineral particle-air bubble interaction in turbulent flow of flotation cell  

SciTech Connect

The calculated potential energies of interaction between hydrophobic particle of three minerals (rhodochrosite, quartz and talc) and air bubble show that the energy of hydrophobic interaction is the dominant factor for their attachment. An attachment rate equation, integrating particle-bubble collision and adhesion by introducing a capture efficiency, has been put forward. It was found that the hydrophobic particle-bubble aggregates can not be disconnected in the bulk zone of flotation cell, whereas in the impeller zone the breakup may occur, particularly for the coarser particles captured by bubble. Finally, the flotation rate constant was estimated theoretically and verified by experiments.

Lu, S.; Song, S.; Gou, J. [Univ. of Science and Technology, Beijing (China). Coll. of Resource Engineering; Pan, Y. [Ministry of Metallurgical Industry of P.R. China, Beijing (China)

1995-12-31

464

Laboratory and in situ flotation rates of lecithotrophic eggs from the bathyal echinoid Phormosoma placenta  

NASA Astrophysics Data System (ADS)

The large, lecithotrophic eggs of the bathyal echinothuriid echinoid Phormosoma placenta are positively buoyant both in vitro and in situ to depths of at least 608 m. Eggs attain terminal velocity in less than 5 cm. At constant salinity, flotation rate is related linearly to temperature; eggs move more slowly at lower temperatures. This effect is attributed to increased water viscosity at lower temperatures, not differential changes in egg and water density. Based on an average flotation velocity of 0.42 cm s -1, it is predicted that eggs produced at bathyal depths will reach the surface in approximately 2 days.

Young, Craig M.; Cameron, J. Lane

1987-09-01

465

Microhydrodynamics of flotation processes in the sea surface layer  

NASA Astrophysics Data System (ADS)

The uppermost surface of the ocean forms a peculiarly important ecosystem, the sea surface microlayer (SML). Comprising the top 1-1000 ?m of the ocean surface, the SML concentrates many chemical substances, particularly those that are surface active. Important economically as a nursery for fish eggs and larvae, the SML unfortunately is also especially vulnerable to pollution. Contaminants that settle out from the air, have low solubility, or attach to floatable matter tend to accumulate in the SML. Bubbles contribute prominently to the dynamics of air-sea exchanges, playing an important role in geochemical cycling of material in the upper ocean and SML. In addition to the movement of bubbles, the development of a bubble cloud interrelates with the single particle dynamics of all other bubbles and particles. In the early sixties, several in situ oceanographic techniques revealed an "unbelievably immense" number of coastal bubbles of radius 15-300 ?m. The spatial and temporal variation of bubble numbers were studied; acoustical oceanographers now use bubbles as tracers to determine ocean processes near the ocean surface. Sea state and rain noises have both been definitively ascribed to the radiation from huge numbers of infant micro bubbles [The Acoustic Bubble. Academic Press, San Diego]. Our research programme aims at constructing a hydrodynamic model for particle transport processes occurring at the microscale, in multi-phase flotation suspensions. Current research addresses bubble and floc microhydrodynamics as building blocks for a microscale transport model. This paper reviews sea surface transport processes in the microlayer and the lower atmosphere, and identifies those amenable to microhydrodynamic modelling and simulation. It presents preliminary simulation results including the multi-body hydrodynamic mobility functions for the modelling of "dynamic bubble filters" and floc suspensions. Hydrodynamic interactions versus spatial anisotropy and size of particle clouds are investigated.

Grammatika, Marianne; Zimmerman, William B.

2001-10-01

466

A saltwater flotation technique to identify unincubated eggs  

USGS Publications Warehouse

Field studies on nesting birds sometimes involve questions related to nest initiation dates, length of the incubation period, or changes in parental incubation behavior during various stages of incubation. Some of this information can be best assessed when a nest is discovered before the eggs have undergone any incubation, and this has traditionally been assessed by floating eggs in freshwater. However, because the freshwater method is not particularly accurate in identifying unincubated eggs, we developed a more reliable saltwater flotation method. The saltwater method involves diluting a saturated saltwater solution with freshwater until a salt concentration is reached where unincubated eggs sink to the bottom and incubated eggs float to the surface. For Laughing Gulls (Leucophaeus atricilla), floating eggs in freshwater failed to identify 39.0% (N = 251) of eggs that were subsequently found by candling to have undergone incubation prior to collection. By contrast, in a separate collection of gull eggs, no eggs that passed the saltwater test (N = 225) were found by a later candling to have been incubated prior to collection. For Double-crested Cormorants (Phalacrocorax auritus), floating eggs in freshwater failed to identify 15.6% (N = 250) of eggs that had undergone incubation prior to collection, whereas in a separate collection, none of the eggs that passed the saltwater test (N = 85) were found by a later candling to have been incubated prior to collection. Immersion of eggs in saltwater did not affect embryo survival. Although use of the saltwater method is likely limited to colonial species and requires calibrating a saltwater solution, it is a faster and more accurate method of identifying unincubated eggs than the traditional method of floating eggs in freshwater.

Devney, C.A.; Kondrad, S.L.; Stebbins, K.R.; Brittingham, K.D.; Hoffman, D.J.; Heinz, G.H.

2009-01-01

467

Funcitonal importance of Belize coral reefs, Wulff52 FUNCTIONAL IMPORTANCE OF BIODIVERSITY FOR CORAL REEFS OF BELIZE1  

E-print Network

Funcitonal importance of Belize coral reefs, Wulff52 FUNCTIONAL IMPORTANCE OF BIODIVERSITY FOR CORAL REEFS OF BELIZE1 Janie Wulff Department of Biological Science, Florida State University, Tallahassee, FL, USA; wulff@bio.fsu.edu ABSTRACT A thriving coral reef results from an intricate collaboration

Ronquist, Fredrik

468

76 FR 59377 - Amendments to the Reef Fish, Spiny Lobster, Queen Conch and Coral and Reef Associated Plants and...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Coral and Reef Associated Plants and Invertebrates Fishery Management Plans of Puerto...Coral and Reef Associated Plants and Invertebrates for the U.S. Caribbean for review...coral and reef associated plants and invertebrates species. The 2011 Caribbean ACL...

2011-09-26

469

76 FR 68711 - Amendments to the Reef Fish, Spiny Lobster, Queen Conch and Coral and Reef Associated Plants and...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Coral and Reef Associated Plants and Invertebrates Fishery Management Plans of Puerto...Corals and Reef Associated Plants and Invertebrates of Puerto Rico and the U.S. Virgin...corals and reef associated plants and invertebrates FMPs. The 2011 Caribbean ACL...

2011-11-07

470

76 FR 82413 - Amendments to the Reef Fish, Spiny Lobster, Queen Conch and Coral and Reef Associated Plants and...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Coral and Reef Associated Plants and Invertebrates Fishery Management Plans of Puerto...Coral and Reef Associated Plants and Invertebrates Fishery Management Plans of Puerto...Corals and Reef Associated Plants and Invertebrates of Puerto Rico and the U.S....

2011-12-30

471

New protection initiatives announced for coral reefs  

NASA Astrophysics Data System (ADS)

Off the coasts of some of the South Pacific's most idyllic-sounding atolls, Austin Bowden-Kerby has seen first-hand the heavy damage to coral reefs from dynamite and cyanide fishing. For instance, while snorkeling near Chuuk, an island in Micronesia, he has observed craters and rubble beds of coral, which locals have told him date to World War II ordnance.A marine biologist and project scientist for the Coral Gardens Initiative of the Foundation for the Peoples of the South Pacific, Bowden-Kerby has also identified what he says are some public health effects related to destroyed coral reefs and their dying fisheries. These problems include protein and vitamin A deficiency and blindness, all of which may—in some instances—be linked to poor nutrition resulting from lower reef fish consumption by islanders, according to Bowden-Kerby.

Showstack, Randy

472

DETAIL VIEW OF LOWER TRAM TERMINAL, SECONDARY ORE BIN, CRUSHER ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

DETAIL VIEW OF LOWER TRAM TERMINAL, SECONDARY ORE BIN, CRUSHER FOUNDATION, AND BALL MILL FOUNDATIONS, LOOKING NORTH NORTHWEST. ORE FROM THE MINES WAS DUMPED FROM THE TRAM BUCKETS INTO THE PRIMARY ORE BIN UNDER THE TRAM TERMINAL. A SLIDING CONTROL DOOR INTRODUCED THE INTO THE JAW CRUSHER (FOUNDATIONS,CENTER). THE CRUSHED ORE WAS THEN CONVEYED INTO THE SECONDARY ORE BIN AT CENTER LEFT. A HOLE IN THE FLOOR OF THE ORE BIN PASSED ORE ONTO ANOTHER CONVEYOR THAT BROUGHT IT OUT TO THE BALL MILL(FOUNDATIONS,CENTER BOTTOM). THIS SYSTEM IS MOST LIKELY NOT THE ORIGINAL SET UP, PROBABLY INSTALLED IN THE MINE'S LAST OCCUPATION IN THE EARLY 1940s. - Keane Wonder Mine, Park Route 4 (Daylight Pass Cutoff), Death Valley Junction, Inyo County, CA

473

Geochemical consequences of increased atmospheric carbon dioxide on coral reefs  

USGS Publications Warehouse

A coral reef represents the net accumulation of calcium carbonate (CaCO3) produced by corals and other calcifying organisms. If calcification declines, then reef-building capacity also declines. Coral reef calcification depends on the saturation state of the carbonate mineral aragonite of surface waters. By the middle of the next century, an increased concentration of carbon dioxide will decrease the aragonite saturation state in the tropics by 30 percent and biogenic aragonite precipitation by 14 to 30 percent. Coral reefs are particularly threatened, because reef-building organisms secrete metastable forms of CaCO3, but the biogeochemical consequences on other calcifying marine ecosystems may be equally severe.

Kleypas, J.A.; Buddemeier, R.W.; Archer, D.; Gattuso, J.-P.; Langdon, C.; Opdyke, B.N.

1999-01-01

474

Reefing Line Tension in CPAS Main Parachute Clusters  

NASA Technical Reports Server (NTRS)

Reefing lines are an essential feature to manage inflation loads. During each Engineering Development Unit (EDU) test of the Capsule Parachute Assembly System (CPAS), a chase aircraft is staged to be level with the cluster of Main ringsail parachutes during the initial inflation and reefed stages. This allows for capturing high-quality still photographs of the reefed skirt, suspension line, and canopy geometry. The over-inflation angles are synchronized with measured loads data in order to compute the tension force in the reefing line. The traditional reefing tension equation assumes radial symmetry, but cluster effects cause the reefed skirt of each parachute to elongate to a more elliptical shape. This effect was considered in evaluating multiple parachutes to estimate the semi-major and semi-minor axes. Three flight tests are assessed, including one with a skipped first stage, which had peak reefing line tension over three times higher than the nominal parachute disreef sequence.

Ray, Eric S.

2013-01-01

475

Parrotfish predation on massive Porites on the Great Barrier Reef  

NASA Astrophysics Data System (ADS)

Parrotfish grazing scars on coral colonies were quantified across four reef zones at Lizard Island, Northern Great Barrier Reef (GBR). The abundance of parrotfish grazing scars was highest on reef flat and crest, with massive Porites spp . colonies having more parrotfish grazing scars than all other coral species combined. Massive Porites was the only coral type positively selected for grazing by parrotfishes in all four reef zones. The density of parrotfish grazing scars on massive Porites spp., and the rate of new scar formation, was highest on the reef crest and flat, reflecting the lower massive Porites cover and higher parrotfish abundance in these habitats. Overall, it appears that parrotfish predation pressure on corals could affect the abundance of preferred coral species, especially massive Porites spp , across the reef gradient. Parrotfish predation on corals may have a more important role on the GBR reefs than previously thought.

Bonaldo, R. M.; Bellwood, D. R.

2011-03-01

476

Pulley reef: a deep photosynthetic coral reef on the West Florida Shelf, USA  

USGS Publications Warehouse

Pulley Reef (24°50?N, 83°40?W) lies on a submerged late Pleistocene shoreline feature that formed during a sea-level stillstand from 13.8 to 14.5 ka (Jarrett et al. 2005). The reef is currently 60–75 m deep, exhibits 10–60% coral cover, and extends over approximately 160 km2 of the sea floor. Zooxanthellate corals are primarily Agaricia lamarcki, A. fragilis, Leptoseris cucullata, and less common Madracis formosa, M. pharensis, M. decactis, Montastraea cavernosa, Porites divaricata, Scolymia cubensis and Oculina tenella. Coralline algae are comparable in abundance to stony corals. Other macroalgae include Halimeda tuna, Dictyota divaricata, Lobophora variegata, Ventricatri ventricosa, Verdigelas pelas, and Kallymenia sp. Anadyomene menziesii is abundant. The reef provides a habitat for organisms typically observed at much shallower depths, and is the deepest known photosynthetic coral reef on the North America continental shelf (Fig. 1).

Culter, J.K.; Ritchie, K.B.; Earle, S.A.; Guggenheim, D.E.; Halley, R.B.; Ciembronowicz, K.T.; Hine, A.C.; Jarrett, B.D.; Locker, S.D.; Jaap, W.C.

2006-01-01

477

Seed flotation and germination of salt marsh plants: The effects of stratification, salinity, and/or inundation regime  

USGS Publications Warehouse

We examined the effects of cold stratification and salinity on seed flotation of eight salt marsh species. Four of the eight species were tested for germination success under different stratification, salinity, and flooding conditions. Species were separated into two groups, four species received wet stratification and four dry stratification and fresh seeds of all species were tested for flotation and germination. Fresh seeds of seven out of eight species had flotation times independent of salinity, six of which had average flotation times of at least 50 d. Seeds of Spartina alterniflora and Spartina patens had the shortest flotation times, averaging 24 and 26 d, respectively. Following wet stratification, the flotation time of S. alterniflora seeds in higher salinity water (15 and 36 ppt) was reduced by over 75% and germination declined by more than 90%. Wet stratification reduced the flotation time of Distichlis spicata seeds in fresh water but increased seed germination from 2 to 16% in a fluctuating inundation regime. Fresh seeds of Iva frutescens and S. alternflora were capable of germination and therefore are non-dormant during dispersal. Fresh seeds of I. frutescens had similar germination to dry stratified seeds ranging 25-30%. Salinity reduced seed germination for all species except for S. alterniflora. A fluctuating inundation regime was important for seed germination of the low marsh species and for germination following cold stratification. The conditions that resulted in seeds sinking faster were similar to the conditions that resulted in higher germination for two of four species. ?? 2009 Elsevier B.V.

Elsey-Quirk, T.; Middleton, B.A.; Proffitt, C.E.

2009-01-01

478

A comparison study of column flotation technologies for cleaning Illinois coal. [Quarterly] technical report, December 1, 1993--February 28, 1994  

SciTech Connect

The objectives of this research project are to optimize the performance of six commercially available column technologies for the treatment of Illinois Basin coal fines and to compare their performance on the basis of the recovery-grade curve and column throughput capacity. A statistically-designed, experimental program will be conducted to optimize the critical operating performance values of each flotation column. During the previous reporting period, construction and installation of the six flotation columns were completed. The flotation feed sample that will be used for the tests in this investigation was collected from a coal preparation plant treating the Illinois No. 5 seam coal. During this reporting period, the flotation feed sample was characterized on a size-by-size basis for its ash, total sulfur, and BTU content. A release analysis was also conducted to obtain the best possible recovery versus product grade curve that can be achieved by a froth flotation process for the treatment of the Illinois No. 5 flotation feed sample. Experiments were initiated on the Jameson Cell. The preliminary results indicate that the Jameson Cell achieves a separation performance that is close to the release data. The experimental program on the Jameson Cell and the other flotation technologies will be performed during the next reporting period.

Honaker, R.Q.; Paul, B.C. [Southern Illinois Univ., Carbondale, IL (United States). Dept. of Mining Engineering

1994-06-01

479

Mining and beneficiation of lunar ores  

NASA Technical Reports Server (NTRS)

The beneficiation of lunar plagioclase and ilmenite ores to feedstock grade permits a rapid growth of the space manufacturing economy by maximizing the production rate of metals and oxygen. A beneficiation scheme based on electrostatic and magnetic separation is preferred over conventional schemes, but such a scheme cannot be completely modeled because beneficiation processes are empirical and because some properties of lunar minerals have not been measured. To meet anticipated shipping and processing needs, the peak lunar mining rate will exceed 1000 tons/hr by the fifth year of operation. Such capabilities will be best obtained by automated mining vehicles and conveyor systems rather than trucks. It may be possible to extract about 40 kg of volatiles (60 percent H2O) by thermally processing the less than 20 micron ilmenite concentrate extracted from 130 tons of ilmenite ore. A thermodynamic analysis of an extraction process is presented.

Bunch, T. E.; Williams, R. J.; Mckay, D. S.; Giles, D.

1979-01-01

480

Reef fish and habitat relationships in a Caribbean seascape: the importance of reef context  

Microsoft Academic Search

Marine protected area (MPA) effectiveness is contingent on understanding key ecological patterns and processes at appropriate\\u000a spatial scales and may depend upon maintaining critical linkages among essential habitat patches to conserve reef-fish communities.\\u000a Hypotheses were tested to investigate the importance of habitat linkages in the US Virgin Islands. As expected, reef context\\u000a (the spatial pattern of surrounding habitat patches) was

R. Grober-Dunsmore; T. K. Frazer; W. J. Lindberg; J. Beets

2007-01-01

481

In Situ Coral Reef Oxygen Metabolism: An Eddy Correlation Study  

PubMed Central

Quantitative studies of coral reefs are challenged by the three-dimensional hard structure of reefs and the high spatial variability and temporal dynamics of their metabolism. We used the non-invasive eddy correlation technique to examine respiration and photosynthesis rates, through O2 fluxes, from reef crests and reef slopes in the Florida Keys, USA. We assessed how the photosynthesis and respiration of different reef habitats is controlled by light and hydrodynamics. Numerous fluxes (over a 0.25 h period) were as high as 4500 mmol O2 m?2 d?1, which can only be explained by efficient light utilization by the phototrophic community and the complex canopy structure of the reef, having a many-fold larger surface area than its horizontal projection. Over diel cycles, the reef crest was net autotrophic, whereas on the reef slope oxygen production and respiration were balanced. The autotrophic nature of the shallow reef crests implies that the export of organics is an important source of primary production for the larger area. Net oxygen production on the reef crest was proportional to the light intensity, up to 1750 µmol photons m?2 s?1 and decreased thereafter as respiration was stimulated by high current velocities coincident with peak light levels. Nighttime respiration rates were also stimulated by the current velocity, through enhanced ventilation of the porous framework of the reef. Respiration rates were the highest directly after sunset, and then decreased during the night suggesting that highly labile photosynthates produced during the day fueled early-night respiration. The reef framework was also important to the acquisition of nutrients as the ambient nitrogen stock in the water had sufficient capacity to support these high production rates across the entire reef width. These direct measurements of complex reefs systems yielded high metabolic rates and dynamics that can only be determined through in situ, high temporal resolution measurements. PMID:23536798

Long, Matthew H.; Berg, Peter; de Beer, Dirk; Zieman, Joseph C.

2013-01-01

482

Tourmaline in the central Swedish ore district  

NASA Astrophysics Data System (ADS)

More than 40 recently discovered tourmaline occurrences have been investigated in the Mid-Proterozoic Bergslagen ore district of central Sweden. Some are spatially associated with ores, others with zones of leaching, remobilization and migmatization. Among the tourmaline-bearing ore deposits are the Dammberg ZnPb-Fe sulphide deposit, the Sala Pb-Zn-Ag deposit, the Dalkarlsberg, Pershyttan and Hĺksberg Fe oxide deposits, the Leja Cu deposit, and the Zinkgruvan Zn-Pb-Ag deposit. Tourmaline has been recorded a) as tourmalinites and tourmaline-bearing chemical sediments; b) in tourmaline-bearing skarns; c) in tourmaline-quartz veins; d) as disseminations along the foliation in schists; e) in tourmaline pegmatites; f) in tourmalinized haloes in metavolcanites along tourmaline pegmatites; and g) in late joints. Tourmalinites, tourmaline-bearing chemical sediments and tourmaline-bearing skarns are spatially associated with sulphide and oxide mineralizations. The dravite components in these tourmalines are proportional to the size of Zn-Pb sulphide mineralizations. Tourmalines from quartz veins close to and within ore deposits contain high Zr and Cr contents. With increasing distance away from these deposits, the Zr and Cr contents fall significantly. Tourmalines from pegmatites have inherited a number of trace element enrichments through partial melting and assimilation of volcaniclastic sediments into granitic melts. Despite magmatic homogenization, Zn contents in these tourmalines reflect the proximity of Zn-Pb-sulphide deposits, decreasing away from them. Tourmalines from late joints with Zn contents above the 100 ppm level are also indicative for the proximity of Zn-Pb sulphide mineralizations. Thus, some trace elements in these tourmalines may represent suitable exploration tools.

Hellingwerf, R. H.; Gatedal, K.; Gallagher, V.; Baker, J. H.

1994-06-01

483

The influence of temperature during flotation of celestite and calcite with sodium oleate and quebracho  

Microsoft Academic Search

A study has been made on the influence of temperature during flotation of the celestite and calcite mineral species, using sodium oleate as the collector and quebracho as the depressant, for a particle size ranging between 80100 A.S.T.M. mesh (177149 ?m). The experiments were conducted on pure minerals in a thermostatted Hallimond tube with working temperatures between 293 and 323

F. Hernáinz Bermúdez de Castro; A. Gálvez Borrego

1996-01-01

484

A Simple Flotation De-Linking Experiment for the Recycling of Paper  

ERIC Educational Resources Information Center

A laboratory exercise for the flotation de-linking of wastepaper is described, which consists of disintegrating printed wastepaper in a blender and then removing the ink or toner contaminants by pumping air bubbles through suspension using an aquarium pump or other source of air bubbles. The exercise has proven extremely reliable and consistent in…

Venditti, Richard A.

2004-01-01

485

A hybrid flotation–membrane process for wastewater treatment: an overview  

Microsoft Academic Search

Wastewater produced from many industries such as dyeing, textile industry, minerals processing\\/ phosphate beneficiation, food processing and deinking is either reused after being treated by conventional treatment methods or pumped to drainage systems without treatment. This represents a serious environmental problem and causes challenges to the countries which face water shortages. A hybrid dissolved air flotation (DAF)-membrane process is a

H. Al-Zoubi; S. Al-Thyabat; L. Al-Khatib

2009-01-01

486

Calculation of the contact angle of a spherical surface with a bubble in flotation  

Microsoft Academic Search

We have developed a method for the calculation of contact angle of spherical particle in interaction with a bubble in the process of flotation. The balance of forces acting on the instantaneous TPC perimeter in the radial direction could connect the central angle ? and the contact angle ? in only one equation depending on the modified Bond number Bo,

M. Bouhenguel; S. Kouachi; A. Bouchemma

2009-01-01

487

Silicone glycol collectors in the beneficiation of fine coal by froth flotation  

SciTech Connect

A froth flotation process for the beneficiation of fine coal is disclosed which employs as a collector a water-dispersible polyorganosiloxane or a mixture of water-dispersible polyorganosiloxanes which contain organic radicals selected from the group consisting of polyethylene oxide and polypropylene oxide radicals. The process of this invention is especially useful for the beneficiation of difficult-to-float fine coals.

Owen, M.J.

1985-07-02

488

Parachute\\/flotation bag recovery system for a large RV nose cone  

Microsoft Academic Search

The design and development of a single stage recovery system consisting of a 6 ft diameter guide surface parachute with a 3.5 cubic foot ram air filled flotation bag for ocean recovery of a 120 lb nose cone is described. Recovery produces start with jettisoning a portion of the initial reentry mass before deploying the parachute. Bibtex entry for this

W. B. Pepper

1980-01-01

489

Parachute/flotation bag recovery system for a large RV nose cone  

SciTech Connect

This report describes the design and development of a single-stage recovery system consisting of a 6-ft dia guide surface parachute with a 3.5 ft/sup 3/ ram-air-filled flotation bag for ocean recovery of a 120-lb nose cone. Recovery procedures start with jettisoning a portion of the initial reentry mass before deploying the parachute.

Pepper, W.M.

1980-03-01

490

Comparison of Phosphonic and Pyrophosphonic Acids as Collectors for the Cassiterite Flotation  

Microsoft Academic Search

Styryl phosphonic acid (SPA) is a collector used in the industrial flotation of cassiterite, During its production from styrene and PCl5 by-products are formed in different amounts. One of these is condensed SPA caused by uncomplete hydrolysis of the intermediary phosphonic acid chloride. Attempts were made to synthesize definite forms of condensed SPA in order to study their influence on

H. Schiefer

1990-01-01

491

On the role of cavitation in particle collection in flotation – A critical review. II  

Microsoft Academic Search

Research in applying hydrodynamic cavitation to recovery of natural resources during the last decade is reviewed. The existence and formation of tiny bubbles or gas nuclei (with diameter from microns down to nano sizes) in natural water were verified from both direct and in-direct measurements, thus providing a foundation for applying hydrodynamic cavitation to flotation systems. The interactions between tiny

Z. A. Zhou; Zhenghe Xu; J. A. Finch; J. H. Masliyah; R. S. Chow

2009-01-01

492

A feed-line aerated flotation column Part I: Batch and continuous testwork  

Microsoft Academic Search

A systematic procedure has been developed for feed-line aerated flotation column evaluation in laboratory and plant. Slurry in batch operation is continuously recirculated from the column bottom through an external aerator and then incremental froth products are collected. In continuous operation, a grade-recovery curve is generated by changing feed and gas rate. The selectivity data from these two modes of

M. Xu; P. Quinn; R. Stratton-Crawley

1996-01-01

493

Bioethical Consideration in the Search for Bioactive Compounds from Reef`s Invertebrates  

NASA Astrophysics Data System (ADS)

The occurrence of large scale of bioactive compounds is not common to all living organisms, but restricted to certain taxonomic groups. Among marine animals, reef`s invertebrates are the most prolific producers of secondary metabolites and have become sources of great interest to natural product chemistry, since they provide a large proportion of bioactive compounds with different biological activities. Perhaps the most significant problem that has hampered the investigation of secondary metabolites is their low concentration. In marine invertebrates many highly active compounds contribute to < 10-6% of the body-wet weight. Providing sufficient amounts of these biologically active substances, hence, may be a difficult task. In addition, it has often proven extremely difficult and some cases impossible, to provide from invertebrates sufficient amounts of many of these substances due to limited amounts found in the producing organism, or to limited quantity of the organism itself, or to geographic, seasonal or sexual variations in the amounts and in the nature of produced secondary metabolites. There has an increasing concerns regarding the collecting reef`s organisms for the discovery and development of pharmaceuticals since it has been perceived variously as sustaining and threatening conservation. There is an urgent need to take into account the bioethical considerations in anticipating the potential consequences of these activities and proposing management options for sustainable use of reef`s invertebrates as the sources of bioactive compounds.

Sukarmi, Ocky; Radjasa, Karna

494

Last interglacial reef growth beneath Belize barrier and isolated platform reefs  

NASA Astrophysics Data System (ADS)

We report the first radiometric dates (thermal-ionization mass spectrometry) from late Pleistocene reef deposits from offshore Belize, the location of the largest modern reef complex in the Atlantic Ocean. The results presented here can be used to explain significant differences in bathymetry, sedimentary facies, and reef development of this major reef area, and the results are significant because they contribute to the knowledge of the regional geology of the eastern Yucatán. The previously held concept of a neotectonically stable eastern Yucatán is challenged. The dates indicate that Pleistocene reefs and shallow-water limestones, which form the basement of modern reefs in the area, accumulated ca. 125 130 ka. Significant differences in elevation of the samples relative to present sea level (>10 m) have several possible causes. Differential subsidence along a series of continental margin fault blocks in combination with variation in karstification are probably the prime causes. Differential subsidence is presumably related to initial extension and later left-lateral movements along the adjacent active boundary between the North American and Caribbean plates. Increasing dissolution toward the south during Pleistocene sea-level lowstands is probably a consequence of higher precipitation rates in mountainous southern Belize.

Gischler, Eberhard; Lomando, Anthony J.; Hudson, J. Harold; Holmes, Charles W.

2000-05-01

495

DISTRIBUTION AND ABUNDANCE OF BRLFISH LARVAE (PISCES: ISTIOPHORIDAE) IN THE GREAT BARRIER REEF LAGOON  

E-print Network

DISTRIBUTION AND ABUNDANCE OF BRLFISH LARVAE (PISCES: ISTIOPHORIDAE) IN THE GREAT BARRIER REEF) of the outer ribbon reefs. Concentration and abundance within the Great Barrier Reef Lagoon were not usually of reef fishes in the vicinity of Lizard Island in the northern region ofthe Great Barrier Reef, Australia

496

Environmental factors associated with the spatial distribution of crustose coralline algae on the Great Barrier Reef  

Microsoft Academic Search

Crustose coralline algae (CCA) fulfill two key functional roles in coral reef ecosystems: they contribute significantly to reef calcification, and they induce larval settlement of many benthic organisms. Percentage cover of CCA, and environmental conditions, were visually estimated on 144 reefs of the Great Barrier Reef between 10 and 24° latitude S. Reefs were located across the shelf and ranged

K. Fabricius; G. De'ath

2001-01-01

497

-Congressional Policy Brief -Coral Reefs: For Health, For Wealth, For Life  

E-print Network

- Congressional Policy Brief - Coral Reefs: For Health, For Wealth, For Life Table of Contents Introduction ­ 1 What are Corals and Coral Reefs? ­ 1 Coral Reef Biology ­ 2 Hazards to Coral Reefs ­ 2 Major Reef-building Coral Diseases ­ 3 Coral Bleaching ­ 4 References and Resource Links ­ 4 "The

498

Serge Andre foue t Hector M. Guzman Coral reef distribution, status and geomorphologybiodiversity  

E-print Network

REPORT Serge Andre´ foue¨ t � Hector M. Guzman Coral reef distribution, status and geomorphology of the reef geomor- phology and benthic communities of Kuna Yala coral reefs (Caribbean Panama) comes from of coral, octocorals, and sponges) and reef health (coral versus algal cover). For a total reef system

Bermingham, Eldredge

499

Sustaining Dry Tortugas National Park Coral Reef Resources Page 1.1 FINAL REPORT FY 2008  

E-print Network

Sustaining Dry Tortugas National Park Coral Reef Resources Page 1.1 FINAL REPORT FY 2008 Fishery-Independent Monitoring of Coral Reef Fishes, Coral Reefs, and Macro-invertebrates in the Dry Tortugas Jerald S. Ault Park Coral Reef Resources Page 1.2 FINAL REPORT FY 2008 Fishery-Independent Monitoring of Coral Reef

Miami, University of

500

Functional Roles of Sponges on Coral Reefs Janie L. Wulff 1  

E-print Network

38 Functional Roles of Sponges on Coral Reefs Janie L. Wulff 1 Barrel sponge on patch of reef excavating sponges can dismantle reefs, and some sponges can overgrow corals, it is now known that sponges also substantially benefit coral reefs and associated ecosystems. Sponges benefit reefs by efficiently

Ronquist, Fredrik