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1

The flotation behaviour of chromite with respect to the beneficiation of UG2 ore  

Microsoft Academic Search

The UG2 reef of the Bushveld Igneous Complex in South Africa is a valuable source of platinum group metals (PGMs) that is beneficiated by flotation. Chromite is one of the main gangue consituents of UG2 ore and it is essential that the amount of chromite reporting to the concentrate during flotation be minimised since it is detrimental to the subsequent

Q. I. Wesseldijk; M. A. Reuter; D. J. Bradshaw; P. J. Harris

1999-01-01

2

Flotation of Pyrochlore from Powderhorn District, Colorado, Ore.  

National Technical Information Service (NTIS)

An investigation was undertaken by the Bureau of Mines to devise a flotation method for concentrating the pyrochlore in a Powderhorn, CO, ore (0.43 pct Cb2O5). The technique involved regrinding and flotation of pyrochlore from a rougher tailing product ob...

E. Morrice G. M. Martinez

1985-01-01

3

Hydrothermal Sulfidation and Flotation of Oxidized Zinc-Lead Ore  

NASA Astrophysics Data System (ADS)

The sample with smithsonite and cerussite as the main valuable metal minerals is a carbonate-hosted lead-zinc ore in the current study. Hydrothermal sulfidation of oxidized zinc-lead ore was carried out with a particle size of 74 to 58 ?m and the mole ratio of sulfur and zinc of 2.0 at 453 K (180 °C) for 240 minutes, and 73 pct zinc and 86 pct lead sulfidation fraction were achieved. Flotation of the unsulfided sample was ineffective, with less than 55 pct recovery of zinc and lead. After sulfidation, the recoveries of zinc and lead in flotation concentrate were over 92 pct. A flotation concentrate was obtained with zinc and lead content of 41.2 pct and 22.1 pct, respectively.

Li, Cun-Xiong; Wei, Chang; Deng, Zhi-Gan; Li, Xing-Bin; Li, Min-Ting; Xu, Hong-Sheng

2014-06-01

4

Investigation of impact of water type on borate ore flotation.  

PubMed

In this work, the impact of water type on borate ore flotation was investigated, while various physical parameters during flotation were considered in order to compare the results. Two different colemanite samples from Emet deposits of Turkey, named as Emet-A and Emet-B contained 44% B(2)O(3) and 40% B(2)O(3), respectively. The flotation tests were performed at feed particle size range of -210 +20 microm. Optimal consumption values for the reagents were determined as 2000 gt(-1) for AeroPromoter R825 from Cytec Company, a sulphonate type collector, 1500 gt(-1) for Procol CA927 from Allied Colloids Company, a sulphosuccinamate type collector and 100 gt(-1) for AeroFrother 70 from Cytec Company, an alcohol-type frother. In the tests, the impeller speed of the Denver-type flotation machine was set to 1200 rpm and the samples were fed into a litre cell at 25% solid/liquid ratio and at natural pH value of the slurry at room temperature. The flotation results obtained from the tests with use of tap water, demineralised water and the artificial water prepared with Ca(2+) and Mg(2+) cations deliberately added into demineralised water were compared to each other in optimal flotation conditions. PMID:15026231

Ozkan, S G; Acar, A

2004-04-01

5

Development of Electrochemical Methods for the Enhancement of Flotation Extraction with Specific References to Chromium Ores.  

National Technical Information Service (NTIS)

A study is presented of the beneficiation of the low-grade domestic chromite ores using both conventional flotation and electro-flotation techniques. The goal is to determine the conditions under which flotation or electro-flotation treatments will effect...

D. Wong F. H. Cocks J. Giner

1978-01-01

6

Flotation of Rare Earths from Bastnaesite Ore.  

National Technical Information Service (NTIS)

As part of its efforts to maximize process efficiency and decrease energy requirements in mineral processes, the Federal Bureau of Mines has investigated methods for beneficiating bastnasite ores from Mountain Pass, Calif. The results of a bench-scale stu...

E. Morrice, M. M. Wong

1982-01-01

7

Flotation-nitric acid leach procedure for increasing uranium recovery from a refractory ore  

Microsoft Academic Search

The Bureau of Mines investigated a flotation-nitric acid leach procedure as part of the goal to maximize minerals and metals recovered from primary and secondary domestic resources. Studies were conducted on an ore that contained carbon-bearing and sulfide mineralization that rendered a portion of the ore refractory (resistant) to conventional leaching technology. The procedure investigated for treating the ore consisted

T. G. Carnahan; K. P. V. Lei

1979-01-01

8

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

9

Flotation-Nitric Acid Leach Procedure for Increasing Uranium Recovery from a Refractory Ore.  

National Technical Information Service (NTIS)

The Bureau of Mines investigated a flotation-nitric acid leach procedure as part of the goal to maximize minerals and metals recovered from primary and secondary domestic resources. Studies were conducted on an ore that contained carbon-bearing and sulfid...

T. G. Carnahan K. P. V. Lei

1979-01-01

10

Effect of Tapioca Flour on the Anionic Flotation of Gangue from Iron Ores.  

National Technical Information Service (NTIS)

The differences in starch demands that occur between ore types subjected to the anionic flotation of calcium-activated gangue and the range of residual starch contents expected to give the best metallurgical response were evaluated on a batch and pilot pl...

A. F. Colombo

1972-01-01

11

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

12

Studies on the influence of a flotation collector reagent on iron ore green pellet properties  

Microsoft Academic Search

The properties of iron ore green pellets with varying additions of a surface-active flotation collector reagent (Atrac) were studied by small-scale balling. The compression strength and plasticity were measured with a semi-automatic measuring device and the pressure curves were saved and subjected to further mathematical treatment. The green pellet breakage was also filmed with a high-speed camera. Adding Atrac to

S. P. E. Forsmo; B. M. T. Björkman; P.-O. Samskog

2008-01-01

13

Urea as promoter in the soap flotation of phosphate ores  

Microsoft Academic Search

Phosphate ores containing siliceous gangue minerals are beneficiated by recovering phosphate mineral into froth product by\\u000a using soap or soap-fuel oil emulsion as collector and sodium silicate as depressant. We show here that urea a polar, non electrolyte\\u000a improves both the recovery and grade of phosphate concentrate when used along with the soap-fuel oil emulsion.

D. M. R. Sekhar; K. Srinivas; G. Prabhulingaiah; Yasser Dassin

2009-01-01

14

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

15

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

16

NANOPARTICLE FLOTATION COLLECTORS  

Microsoft Academic Search

Flotation is a critical operation in the isolation of valuable minerals from natural ore. Before flotation, chemical collectors are routinely added to ground ore slurries. Collectors selectively bind to mineral-rich particles, increasing their hydrophobicity thus promoting selective flotation. Conventional collectors are small surfactants with a short hydrocarbon tail (2-6 carbons) and a head group, such as xanthate. In this work,

Songtao Yang

2012-01-01

17

The Successful Application of Pneumatic Flotation Technology for the Removal of Silica by Reverse Flotation at the Iron Ore Pellet Plant of Compañía Minera Huasco, Chile  

Microsoft Academic Search

Pneumatic flotation, as developed by Dr Rainer Imhof, has been applied in commercial beneficiation operations since 1987. Over 85 flotation cells have been installed in more than 30 operations, successfully beneficiating a wide range of minerals. Pneumatic flotation is however still considered as a non-conventional flotation process. Due to its highly selective nature in operation it has generally found its

R Imhof; M Battersby; F Parra; S Sanchez-Pino

18

Pilot Mill Flotation of Anorthositic Platinum-Palladium Ore from the Stillwater Complex.  

National Technical Information Service (NTIS)

The Bureau of Mines investigated methods for beneficiating platinum-group metal ores from the Stillwater Complex, Montana, as part of its program to increase the supply of critical and strategic minerals and metals from domestic resources. This report pre...

E. Morrice

1983-01-01

19

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

20

Molybdenite Flotation.  

National Technical Information Service (NTIS)

Molybdenite (MOS2) is recovered from copper sulfide flotation concentrates by froth flotation, using steam-air injection into the concentrate flotation pulp at a temperature of about 70 to 100 C, in the presence of activated carbon and soluble sulfide rea...

J. L. Huiatt G. M. Potter M. D. Shurtz

1978-01-01

21

Molybdenite Flotation.  

National Technical Information Service (NTIS)

Molybdenite (MoS2) is recovered from copper sulfide flotation concentrates by froth flotation utilizing steam-air injection into the concentrate flotation pulp at a temperature of about 70 to 100C in the presence of activated carbon and soluble sulfide re...

J. L. Huiatt M. D. Shurtz G. M. Potter

1979-01-01

22

Role of oily bubbles in enhancing bitumen flotation  

Microsoft Academic Search

A recognized challenge in bitumen extraction is the reduced bitumen recovery when processing high-fine ores or “weathered” oil sand ores, collectively called poor processing ores. Preliminary lab tests demonstrated that bitumen flotation recovery from these ores could be greatly enhanced by using oily bubbles (air bubbles coated with a thin layer of oil or solvent) instead of air bubbles. In

Li Su; Zhenghe Xu; Jacob Masliyah

2006-01-01

23

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

24

Ore and coal beneficiation method  

Microsoft Academic Search

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

Abadi

1987-01-01

25

Utilization of soluble starch as a depressant for the reverse flotation of diaspore from kaolinite  

Microsoft Academic Search

The utilization of a non-toxic natural polysaccharide, soluble starch, in the flotation of diaspore and kaolinite with emphasis on depression of diaspore in the reverse flotation of bauxite ores by using a Gemini cationic collector, is reported in this work. Firstly, the depressant effect of soluble starch was studied by pure mineral micro-flotation of diaspore and kaolinite as functions of

Liuyin Xia; Hong Zhong; Guangyi Liu; Shuai Wang

2009-01-01

26

Processing of Cobalt-Copper-Arsenic Complex Ore Concentrate  

Microsoft Academic Search

Extraction of cobalt from complex ore flotation concentrates obtained from the Blackbird Mine. Idaho. USA is reviewed. After flotation of a primary copper concentrate, a bulk concentrate is recovered containing major amounts of cobalt, arsenic, and iron, with minor amounts of copper and nickel. This concentrate can be upgraded during flotation by removing iron, but with considerable cobalt loss. Chemical

ROBERT W. BARTLETT

1995-01-01

27

Quantitative image analysis of bubble cavities in iron ore green pellets  

Microsoft Academic Search

Scanning electron microscopy and image analysis was used for quantitative analysis of bubble cavities in iron ore green pellets. Two types of pellets prepared with and without addition of flotation reagent prior to balling were studied. The bubble cavity porosity amounted to 2.8% in the pellets prepared without addition of flotation reagent prior to balling. When flotation reagent was added

I. U. Bhuiyan; J. Mouzon; S. P. E. Forsmo; J. Hedlund

2011-01-01

28

Pentlandite–lizardite interactions and implications for their separation by flotation  

Microsoft Academic Search

Magnesium silicate bearing minerals, such as lizardite, are known to cause problems in the flotation of nickel sulfide ores (e.g. pentlandite), by adhering to the valuable mineral particles. Addition of the polymeric dispersant, carboxymethyl cellulose (CMC), has been found to improve nickel recovery during flotation. The interaction between lizardite and pentlandite has been directly investigated using the atomic force microscope

Kristen E. Bremmell; Daniel Fornasiero; John Ralston

2005-01-01

29

Economic Evaluation of Preconcentration of Uranium Ores. Final Report.  

National Technical Information Service (NTIS)

The economics of two options for the preconcentration of low-grade uranium ores prior to hydrochloric acid leaching were studied. The first option uses flotation followed by wet high-intensity magnetic separation. The second option omits the flotation ste...

1981-01-01

30

The effect of lizardite surface characteristics on pyrite flotation  

NASA Astrophysics Data System (ADS)

The effect of lizardite surface characteristics on pyrite flotation has been investigated through flotation tests, adsorption tests, zeta potential measurements, FTIR study, X-ray photoelectron spectroscopy (XPS) and sedimentation tests. The flotation results show that at pH value 9, where flotation of nickel sulfide ores is routinely performed, two kinds of lizardite samples (native lizardite and leached lizardite) have different effects on the flotation of pyrite. The native lizardite adheres to the surface of pyrite and reduces pyrite flotation recovery while the leached lizardite does not interfere with pyrite flotation. Infrared analyses and XPS tests illustrate that acid leaching changed the surface characteristics of lizardite mineral and the leached lizardite has less magnesium on its surface. It has been determined that the electro-kinetic behavior of lizardite aqueous suspensions is mainly a function of the Mg/Si atomic ratio on lizardite surface. So, the low isoelectric point observed in the leached sample has been linked to values of this ratio lower than that of the native lizardite.

Feng, Bo; Feng, Qiming; Lu, Yiping

2012-10-01

31

A review of zinc oxide mineral beneficiation using flotation method.  

PubMed

In recent years, extraction of zinc from low-grade mining tailings of oxidized zinc has been a matter of discussion. This is a material which can be processed by flotation and acid-leaching methods. Owing to the similarities in the physicochemical and surface chemistry of the constituent minerals, separation of zinc oxide minerals from their gangues by flotation is an extremely complex process. It appears that selective leaching is a promising method for the beneficiation of this type of ore. However, with the high consumption of leaching acid, the treatment of low-grade oxidized zinc ores by hydrometallurgical methods is expensive and complex. Hence, it is best to pre-concentrate low-grade oxidized zinc by flotation and then to employ hydrometallurgical methods. This paper presents a critical review on the zinc oxide mineral flotation technique. In this paper, the various flotation methods of zinc oxide minerals which have been proposed in the literature have been detailed with the aim of identifying the important factors involved in the flotation process. The various aspects of recovery of zinc from these minerals are also dealt with here. The literature indicates that the collector type, sulfidizing agent, pH regulator, depressants and dispersants types, temperature, solid pulp concentration, and desliming are important parameters in the process. The range and optimum values of these parameters, as also the adsorption mechanism, together with the resultant flotation of the zinc oxide minerals reported in the literature are summarized and highlighted in the paper. This review presents a comprehensive scientific guide to the effectiveness of flotation strategy. PMID:23571227

Ejtemaei, Majid; Gharabaghi, Mahdi; Irannajad, Mehdi

2014-04-01

32

Coral Reefs  

NSDL National Science Digital Library

This page offers information on coral reefs. Coral reefs are often refered to as the rainforest of the oceans. This exploration will help you to see why that is. Follow these links to learn about coral reefs. This link will take you to Florida where a girl will take guide you over a coral reef. Coral Kid This site ...

Amsden

2009-11-19

33

Reef ED  

NSDL National Science Digital Library

Great Barrier Reef Marine Park Authority's resource and activity center for teachers and students. Find teaching units for K-12 on: coral reef habitats and marine life; human dependence and impacts on the reef; biodiversity and threatened species; coastal zone and reef management. Lesson plans offer objectives, inquiry learning focus activities, resources, class or field activities. Student pages contain: marine life profiles; reef conservation projects; role playing activities; web investigations. Excellent image library (stills and video).

34

Reef Check  

NSDL National Science Digital Library

Reef Check, headquartered at the Institute of the Environment at the University of California Los Angeles, is a "volunteer, community-based monitoring protocol designed to measure the health of coral reefs on a global scale." With scientific reef surveys conducted in over 60 countries and territories, Reef Check has been able to track global trends in reef health to better inform possible conservation strategies. Visitors to the Reef Check Web site can read result summaries for the 1997-2001 monitoring period, and check out the organization's current and archived newsletters. Other resources include information on survey methods, Reef Check publications, a species identification guide, and other resources geared mainly toward Reef Check volunteers.

35

Coral Reefs  

NSDL National Science Digital Library

This learning resource is a report from The Science Report about Coral Reefs.It includes Lesson Plans,extended interviews, case studies and other related resources on this topic. Some scientists are concerned that overfishing, pollution and global warming are killing parts of the world's coral reefs. Correspondent Betty Ann Bowser reports on efforts to preserve the reefs. In the second part of the series, Bowser explores the potential of reefs to provide the raw materials for life-saving drugs.

The Science Reports (;)

2005-02-01

36

Reef Relief  

NSDL National Science Digital Library

A thorough overview of coral reefs around the globe, including the threats facing them, current protection projects, and action you can take to help save reefs. "International Projects" and "The Coral Reef Ecosystem" sections are chock-full of fantastic photographs and information. Education materials may be purchased and include DVDs and teacher's guides. Many volunteer and donation opportunities. Children section includes information-filled printable coloring pages. Several different publications are available at no cost.

37

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

38

Coral Reefs  

NSDL National Science Digital Library

Description of coral reef environment for high school level and higher. Page is chock full of fantastic photographs each featuring a descriptive caption. Topics discussed include ecology, symbiosis, and predator defense. The site features many different species and stages of coral from all over the globe, and also many of the fishes that are associated with coral reefs.

39

Flotation of Pyrite from Coal.  

National Technical Information Service (NTIS)

Pyrite is removed from coal by means of a two-stage froth flotation process. In the first stage, coarse pyrite is removed as underflow in a conventional froth flotation operation. In the second stage, the froth product from the first stage is subjected to...

K. J. Miller

1972-01-01

40

Coral Reefs  

NSDL National Science Digital Library

Scientists are studying coral reefs around the world to discover the impact that warmer temperatures and increased carbon dioxide may have on the life cycle of corals. "Changing Planet" is produced in partnership with the National Science Foundation.

Learn, Nbc

2010-10-07

41

Iron Ore.  

National Technical Information Service (NTIS)

Iron ore is an important mineral commodity because it is the primary source of iron, the metal most widely used by man. World production of iron ore in 1977 was estimated at 840 million tons, and an estimated 350 million tons was shipped in international ...

F. L. Klinger

1978-01-01

42

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

43

Control pollution by air flotation  

SciTech Connect

The factors that affect the performance of induced air flotation CEM systems are gas availibility, influent loading, chemical conditioning, and skimmer operation. The relative significance of these factors is studied. A bench-scale induced air flotation system has been designed and equipped with sampling and analysis devices to monitor performance as a function of time. It is found that absorbence declines rapidly from the time that air is inducted into the flotation cell. Equations for the rate of oil removal from the wastewater is determined. Oil Concentration factor is also studied. Finally, the use of cationic polyelectrolytes, such as polymers that aid flotation, can be implemented to enhance the polymer-interface interaction and minimize polymer-water interactions which slow down the process.

Burkhardt, C.W.

1983-05-01

44

33 CFR 183.112 - Flotation material and air chambers.  

Code of Federal Regulations, 2013 CFR

... false Flotation material and air chambers. 183.112 Section 183.112 ...183.112 Flotation material and air chambers. (a) Flotation materials must...in a sealed compartment. (b) Air chambers used to meet the flotation...

2013-07-01

45

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

46

A flotation study of refuse pond coal slurry  

Microsoft Academic Search

The flotation behavior of a refuse pond fine coal slurry sample was studied using mechanical and column flotation techniques. Flotation parameters investigated included type and dosage of frother and collector, agitation speed, scrubbing time, slurry pH, etc. for the mechanical flotation cell, and air flow rate, feed flow rate, and wash water flow rate for the column flotation. Flotation kinetics

D. Tao; B. Li; S. Johnson; B. K. Parekh

2002-01-01

47

Energy Oriented Study of Industrial Flotation Systems.  

National Technical Information Service (NTIS)

An energy oriented study was conducted in an effort to determine energy requirements for flotation systems and to direct attention to methods for reducing energy demand in this unit operation. The three major flotation systems, namely, dissolved air, disp...

A. S. Richardson W. P. Jensen

1977-01-01

48

Picobubble Column Flotation of Fine Coal  

Microsoft Academic Search

Froth flotation is widely used in the coal industry to clean ?28 mesh (0.6 mm) or ?100 mesh (0.15 mm) fine coal. A successful recovery of particles by flotation depends on efficient particle-bubble collision and attachment with minimal subsequent particle detachment from bubble. Flotation is effective in a narrow size range, nominally 10–100 µm, beyond which the flotation efficiency drops sharply. A fundamental analysis has

Daniel Tao; Samuel Yu; Xiaohua Zhou; R. Q. Honaker; B. K. Parekh

2008-01-01

49

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

50

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

51

Some Flotation Characteristics of Gold.  

National Technical Information Service (NTIS)

At present there are nineteen flotation plants in South Africa that treat gold-bearing material. Seven of these plants recover the gold from run-of-mine material, and others treat old dump material and currently produced tailings for their residual gold. ...

S. A. Allison R. C. Dunne

1985-01-01

52

Reef Education Network  

NSDL National Science Digital Library

The University of Queensland's Reef Education Network (REN) is a wonderful introduction to the amazing world of coral reefs. REN has some cool images as well as information about reef research, current problems threatening coral reefs, and the many fascinating organisms that reside within a coral reef. The Life And Times section provides a nice overview of what a reef is, while the Ask A Brain Coral section gives some introduction to biotic and abiotic relationships that occur within reefs. A unique feature is the notebook, where students can record and organize information as they navigate throughout the site.

2001-01-01

53

NOAA's Coral Reef  

NSDL National Science Digital Library

Portal to NOAA programs on coral reef research, management, protection. Online booklet describes corals, importance of reefs as habitat, value to humans, natural and human impacts. Site offers outreach and online educational materials, including lesson plans and list of things you can do. Search coral reef data and publications, find funding opportunities, review state of U.S. reefs, local and national action plans. Provides links to related sites, including coral reef photo library, international initiatives.

54

Great Barrier Reef, Queensland, Australia  

NASA Technical Reports Server (NTRS)

This detailed view of the Great Barrier Reef, Queensland, Australia (19.5S, 149.5E) shows several small patch reefs within the overall reef system. The Great Barrier Reef, largest in the world, comprises thousands of individual reefs of great variety and are closely monitored by marine ecologists. These reefs are about 6000 years old and sit on top of much older reefs. The most rapid coral growth occurs on the landward side of the reefs.

1990-01-01

55

Modeling and optimization of flotation processes for coal precleaning.  

National Technical Information Service (NTIS)

Mathematical modeling with a new view toward optimizing the flotation process used in coal cleaning, whether conventional (or batched) froth flotation or column flotation, has been formulated to include mass and momentum balances. Previous mathematical mo...

W. T. Sha S. L. Soo

1990-01-01

56

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

57

Coral Reef Ecosystems: The Living Reef  

NSDL National Science Digital Library

This Science Object is the first of four Science Objects in the Coral Reef Ecosystems SciPack. It explores the unique and diverse ecosystem of the coral reef. Coral reefs are very complex systems that create one of the largest structures on Earth of biological origins. Thousands of coral species exist in oceans worldwide. Reef-building corals remain on the same spot of the sea floor through their entire lives and have developed reproductive, feeding, and social behaviors suited to their situation. As they grow, reefs provide structural habitats for hundreds to thousands of different organisms. Learning Outcomes:� Identify coral polyp structures and describe their functions.� Describe photosynthesis in the coral environment.� Describe the evolution of a typical reef system.� Use the shape of an individual coral to identify its common name, and classify entire coral reef ecosystems based on shape and location. � Describe the process of coral polyp reproduction and growth.� Identify how the features and/or behavioral strategies of coral reef inhabitants enable them to survive in coral reef environments.

National Science Teachers Association (NSTA)

2006-11-01

58

Recovery of Scheelite and Byproduct Sphalerite from Western U.S. Tactite Ores.  

National Technical Information Service (NTIS)

Bench-scale flotation tests were conducted on two western tactite ores to study the recovery of tungsten and zinc minerals. The investigation, which is part of the Bureau of Mines ongoing program to develop methods for beneficiating minerals and metals fr...

J. M. Gomes A. E. Raddatz M. M. Wong

1982-01-01

59

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

60

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

61

Coral Reef Hydrogeology.  

National Technical Information Service (NTIS)

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 Pacifi...

R. W. Buddemeier J. A. Oberdorfer

1985-01-01

62

NOAA's Coral Reef  

NSDL National Science Digital Library

In an effort to centralize information on Coral Reefs, the National Oceanic and Atmospheric Administration (NOAA) has launched this site on Coral Reefs. The site serves both as a news resource (see the frequently updated News Releases section) as well as a basic information resource (see Year of the Reef 1997 and Coral Reef Photos) on coral reefs. For information on current research (scientific and citizen), see the Coral Health and Monitoring Program, the Great American Fish Count, or the Coral Reef Initiative sections. Additionally, a dozen Coral Reef Links point users to further resources. For the pure enthusiast or beginning college student, this site serves as a fine entry-way into learning about Coral Reefs.

63

Planetary Coral Reef Foundation  

NSDL National Science Digital Library

The Planetary Coral Reef Foundation was founded in 1991 to address the growing crisis of destruction of coral reefs. Topics include the PCRF's mission, its research activities at sea and in space, wastewater recycling, conservation tips that can help preserve reefs, and the organization's ship, R.V. Heraclitus.

64

Journey to the Reef  

ERIC Educational Resources Information Center

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-grade students. Students shared their knowledge in language arts and even explored coral reefs in…

Bryson, Linda

2010-01-01

65

An integrated approach to dissolved air flotation.  

PubMed

DAFRapide techniques utilising reduced flocculation times, of the order of 5 minutes, together with flotation loading rates of up to 40 m/h, can be incorporated with conventional filtration systems operating at up to 20 m/h. Product quality of typically < 1 NTU and < 0.1 NTU after flotation and filtration respectively can be achieved. PMID:11394273

Amato, T; Edzwald, J K; Tobiason, J E; Dahlquist, J; Hedberg, T

2001-01-01

66

Reefs happen  

USGS Publications Warehouse

Corals and coral reefs confront us with a variety of paradoxes in terms of their responses to global change. The species appear evolutionarily long-lived and stable, and combinations of organisms recur and persist at levels ranging from endosymbiosis to palaeocommunity structure. The fact that these organisms and communities occupy a seemingly precarious environment near the common interface of land, sea, and air suggests that they possess powerful adaptive and acclimative mechanisms, and the special characteristics associated with their range of reproductive options, their modular (colonial) form, and their symbiotic associations provide multiple pathways for adaptation. At the same time, they are widely considered to be vulnerable to anthropogenic stresses, and to show signs of deterioration on a global scale. Interest in corals is further enhanced by their unique position with regard to the carbon cycle, with inorganic and organic carbon metabolisms that are of comparable magnitudes. The durable limestone structures they create modify the shallow-water environment, and their mineral skeletons preserve in their isotopic, chemical, and structural characteristics records of past environmental conditions. Whether as survivors, recorders, or victims, their relationship to global change is fascinating and instructive. This paper provides a general background and context for the specific papers that make up this topical issue of Global Change Biology. ?? 1996 Blackwell Science Ltd.

Kinzie, III, R. A.; Buddemeier, R. W.

1996-01-01

67

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.

68

Surface chemical problems in coal flotation  

NASA Astrophysics Data System (ADS)

As the use of coal increases and more fine material is produced by mining and processing, the need for improved methods of coal beneficiation increases. While flotation techniques can help meet these needs, the technique is beset with many problems. These problems involve surface chemical and interfacial properties of the coal-mineral-water slurry systems used in coal flotation. The problems associated with coal flotation include non-selectivity, inefficient reagent utilization, and excessive variablity of results. These problems can be broadely classified as a lack of predictability. The present knowledge of coal flotation is not sufficient, in terms of surface chemical parameters, to allow prediction of the flotation response of a given coal. In this paper, some of the surface chemical properties of coal and coal minerals that need to be defined will be discussed in terms of the problems noted above and their impact on coal cleaning.

Taylor, S. R.; Miller, K. J.; Deurbrouck, A. W.

1981-02-01

69

Coral Reef Adventure  

NSDL National Science Digital Library

This site from MacGillivray Freeman Films presents information about the movie "Coral Reef Adventure," as well as an assortment of links about coral reefs. In particular, the section on Learning About Reefs features a virtual dive that highlights marine life at various depths. This section also provides educational resources including a teacher's guide and learning activities. The site also includes links to many organizations that provide support for reversing the current worldwide decline in coral reef ecosystems and to finding new and sustainable solutions for managing the world's coral reefs.

Freeman, Macgillivray

70

Dioramas: Andros Coral Reef  

NSDL National Science Digital Library

In the shallow waters off the coast of Andros Island in the Caribbean, corals of all shapes and sizes form the Andros Reef, one of the largest barrier reefs in the world. Like other coral reefs, Andros was created by massive colonies of coral polyps, which are small, soft-bodied animals. These creatures have hard skeletons that form much of the structure of a coral reef. The once thriving Andros Reef is now threatened. In the past, antler-shaped elkhorn coral dominated the reef, with multiple colonies extending continuously for long stretches. Throughout the Caribbean today, this species exists primarily in isolated colonies and scientists estimate that in certain places, up to 95 percent of elkhorn coral has died. This site describes the formation of the reef along with the present problems.

71

Molecular interactions at the solid liquid interface with special reference to flotation and solid particle stabilized emulsions  

Microsoft Academic Search

Summary The experiments carried out with a variety of pure surface active agents, employed in flotation of ores as either collectors or frothers, show that (a) long chain homologues of alcohols and alkyl sulphates react strongly with xanthates at the air\\/liquid interface (Langmuir-trough experiments), (b) the molecular interactions between frothers and collectors occur at the solid\\/liquid interface — if the

J. H. Schulman; J. Leja

1954-01-01

72

Coral Reef Ecosystems  

NSDL National Science Digital Library

The Coral Reef Ecosystems SciPack explores the unique and diverse ecosystem of the coral reef. The focus is on Standards and Benchmarks related to populations and ecosystems using coral reefs and their immediate environment as an example. Because the Standards and Benchmarks present the concepts of populations and ecosystems generically, without reference to a specific ecosystem or the organisms in the system, coral reefs are used to provide the context through which concepts in a marine ecosystem are explored.In addition to comprehensive inquiry-based learning materials tied to Science Education Standards and Benchmarks, the SciPack includes the following additional components:� Pedagogical Implications section addressing common misconceptions, teaching resources and strand maps linking grade band appropriate content to standards. � Access to one-on-one support via e-mail to content "Wizards".� Final Assessment which can be used to certify mastery of the concepts.Learning Outcomes:Coral Reef Ecosystems: The Living Reef� Identify coral polyp structures and describe their functions.� Describe photosynthesis in the coral environment.� Describe the evolution of a typical reef system.� Use the shape of an individual coral to identify its common name, and classify entire coral reef ecosystems based on shape and location. � Describe the process of coral polyp reproduction and growth.� Identify how the features and/or behavioral strategies of coral reef inhabitants enable them to survive in coral reef environments.Coral Reef Ecosystems: The Abiotic Setting� 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.Coral Reef Ecosystems: Interdependence� Identify and label key components of food chains and food webs in a coral reef ecosystem.� Describe key relationships among plants and animals in the coral reef ecosystem: predator and prey relationships, producer and consumer relationships, and symbiotic relationships (mutualism, commensalisms, parasitism).� Recognize the direction that energy travels through food chains and food webs.� Explain that materials (chemical elements) and natural resources are recycled in coral reef ecosystems and reappear in different forms.� Describe the primary ecological succession events within a typical coral reef ecosystem.Coral Reef Ecosystems: Ecosystems in Crisis� Describe ways in which human activities directly impact coral reef ecosystems (resource and recreational uses).� Describe ways in which human activities indirectly impact coral reef ecosystems (by changing the physical conditions, pollution, changes in the water chemistry, etc.).� Explain how human activity may decrease the reefs ability to recover from natural occurrences. � Explain the effects of increased predation or disease on a reef ecosystem.� Describe the effect of habitat loss on the reef ecosystem.� Describe the effects of weather and climate change on a healthy and weakened reef ecosystem.

National Science Teachers Association (NSTA)

2007-03-28

73

Fine Grinding and Flotation to Desulfurize Coal.  

National Technical Information Service (NTIS)

Because of the growing need to develop new technology for producing superior quality coals to replace oil and natural gas, the US Department of Energy's Coal Preparation Division is looking at fine grinding and multistage flotation processes to maximize t...

K. J. Miller

1985-01-01

74

Coral Reef Connections  

NSDL National Science Digital Library

This resource explores Australias Great Barrier Reef, the largest structure on Earth built by living organisms. Consisting of almost 3000 individual reefs, the Great Barrier Reef houses an incredible array of biodiversity. This resource demonstrates the types of relationships among living things that have contributed to this incredible biodiversity and elaborates on some of the adaptations that have enabled species to survive and reproduce in this unique habitat.

Science NetLinks (PBS;)

2002-04-29

75

Children on the reef  

Microsoft Academic Search

Meriam children are active reef-flat collectors. We demonstrate that while foraging on the reef, children are significantly\\u000a less selective than adults. This difference and the precise nature of children’s selectivity while reef-flat collecting are\\u000a consistent with a hypothesis that both children and adults attempt to maximize their rate of return while foraging, but in\\u000a so doing they face different constraints

Douglas W. Bird; Rebecca Bliege Bird

2002-01-01

76

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

77

Micronized coal beneficiation by froth flotation process  

Microsoft Academic Search

The Froth flotation technique has not been widely applied industrially to separate processing of the ultrafine size fraction of coal. This is due to the low efficiencies and costly operations that make the treatment of ultrafine coal by froth-flotation uneconomical. A study of the effect of dosage of various reagents such as MIBC, Fuel Oil\\/MIBC, and Fuel Oil\\/Shur-coal (2027), on

Ayat

1986-01-01

78

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.

2007-11-20

79

PDU-scale testing of microbubble flotation  

SciTech Connect

Work during this past quarter focused primarily on Tasks 1.2.5 (Coarse Coal Flotation) and 1.2.7 (Refuse Pond Flotation). The performance comparison between microbubble column flotation and conventional flotation was continued using minus-28-mesh Pittsburgh No. 8 seam coal. For an equivalent recovery, the microbubble column reduced the final ash content of the product by more than 25% over that obtained using conventional flotation. It was found that the 14-inch diameter microbubble column could produce a 4.5% ash product from a 11% ash feed with combustible recoveries in excess of 95% at a feed rate of 300 lb/hr. In addition, flotation tests were conducted on a minus-325-mesh, high-ash (45--50%) classifying cyclone overflow stream in order to study the feasibility of the microbubble process for producing a clean coal product from what is normally considered refuse material. Results indicate that the column is capable of reducing the ash content to a range of 4.5 to 11% with corresponding combustible recoveries of 57 to 85%, respectively. 4 figs., 3 tabs.

Yoon, R.H.; Adel, G.T.; Luttrell, G.H.

1989-01-01

80

Contribution to the Study of Water-Hydrocarbon Separation by Flotation.  

National Technical Information Service (NTIS)

Flotation mechanisms are studied for its application to the separation of water-hydrocarbon emulsion. At a pilot scale two flotation techniques are studied: flotation with dissolved air (bubble mean diameter 70 microns) and flotation with dispersed air (b...

N. Siem

1983-01-01

81

Reef Education Evaluation: Environmental Knowledge and Reef Experience  

ERIC Educational Resources Information Center

Background: The Reef education evaluation: environmental knowledge and reef experience report concerns PhD research about marine education, and the investigation of learning with high school students and the effect of coral reef monitoring marine experiential education interventions. The effectiveness of classroom learning and reef trips were…

Stepath, Carl M.

2005-01-01

82

U.S. Coral Reef Taskforce  

NSDL National Science Digital Library

Government task force created in 1998 to research, monitor and conserve coral reefs. Site includes: background on coral reef habitats; reef ecology and environmental requirements; environmental requirements of reefs; reef functions and significance; natural and human threats to reefs. Also covered are: Task Force actions; policies and partnerships; and the National Action Plan for Coral Reef Conservation.

83

Rigs-to-reefs  

Microsoft Academic Search

Rigs-to-Reefs is a catchy term for converting obsolete, nonproductive offshore oil and gas structures (platforms and rigs) to designated artificial reefs. The concept has been around for a long time; however, it is only in the last few years that broad public and private support for the idea has emerged. Government and industry have begun to look at the opportunities

Reggio; V. C. Jr

2009-01-01

84

Rivers, runoff, and reefs  

Microsoft Academic Search

The role of terrigenous sediment in controlling the occurrence of coral reef ecosystems is qualitatively understood and has been studied at local scales, but has not been systematically evaluated on a global-to-regional scale. Current concerns about degradation of reef environments and alteration of the hydrologic and sediment cycles place the issue at a focal point of multiple environmental concerns. We

C. J. McLaughlin; C. A. Smith; R. W. Buddemeier; J. D. Bartley; B. A. Maxwell

2003-01-01

85

Rivers, Runoff, and Reefs  

Microsoft Academic Search

Abstract: The role of terrigenous sediment in controlling the occurrence of coral reef ecosystems is qualitatively understood and has beenstudied at local scales, but has not been systematically evaluated on a global-to-regional scale. Current concerns about degradationof reef environments and alteration of the hydrologic and sediment cycles place the issue at a focal point of multiple environmentalconcerns. We use a

Mclaughlin Smith Buddemeier

2003-01-01

86

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

87

Create a Coral Reef  

NSDL National Science Digital Library

In this hands-on OLogy activity, kids learn about coral reefs by building a diorama. Students are introduced to coral polyps and reefs and given illustrated, step-by-step directions that show how to construct a diorama containing models of a brain coral, a sea fan, a sponge, and sea anemones.

88

Life on the Reef  

NSDL National Science Digital Library

This Expeditions Web site takes an in-depth look at life on one of the world's largest barrier reefs. The site begins with a brief explanation of the expedition and what its participants were looking to find. Dive the Reef is an interactive feature that allows students to learn what separates a lagoon from a reef from a shelf. Meet the Scientists has brief biographies of the 14 team members who participated in the expedition. At the Museum is an article that discusses the selection of the barrier reef system of Andros Island as well as the AMNH's long history of Bahamian research. The Reef from Space explains how NASA's computer-enhanced pictures from space contributed to the expedition's findings. The site also includes 12 dispatches written during the expedition, which can be found in the Today from the Bahamas section.

89

ReefBase, A Global Information System on Coarl Reefs  

NSDL National Science Digital Library

ReefBase is an online information system dedicated to coral reefs. The site aims to facilitate sustainable management of coral reefs and related coastal/marine environments. Included are data and information on the location, status, threats, monitoring, legislation, and management of coral reefs in 131 countries, extensive data on coral bleaching, a state-of-the-art online mapping-system that allows custom-made maps of coral reefs and related datasets, and an extensive bibliography of publications.

Reefbase

90

Vitrification of copper flotation waste.  

PubMed

The vitrification of an hazardous iron-rich waste (W), arising from slag flotation of copper production, was studied. Two glasses, containing 30wt% W were melted for 30min at 1400 degrees C. The first batch, labeled WSZ, was obtained by mixing W, blast furnace slag (S) and zeolite tuff (Z), whereas the second, labeled WG, was prepared by mixing W, glass cullet (G), sand and limestone. The glass frits showed high chemical durability, measured by the TCLP test. The crystallization of the glasses was evaluated by DTA. The crystal phases formed were identified by XRD resulting to be pyroxene and wollastonite solid solutions, magnetite and hematite. The morphology of the glass-ceramics was observed by optical and scanning electron microscopy. WSZ composition showed a high rate of bulk crystallization and resulted to be suitable for producing glass-ceramics by a short crystallization heat-treatment. WG composition showed a low crystallization rate and good sinterability; glass-ceramics were obtained by sinter-crystallization of the glass frit. PMID:17064848

Karamanov, Alexander; Aloisi, Mirko; Pelino, Mario

2007-02-01

91

Electrochemical Flotation Concept for Removing Oil from Water.  

National Technical Information Service (NTIS)

A study was undertaken to determine the feasibility of an electrochemical flotation system for separating oil from bilge water. This system involves flotation, using electrolytically-produced micro-gas bubbles, subsequent to coagulation and/or adsorption ...

Q. H. McKenna H. H. Helber L. M. Carrell R. F. Tobias

1973-01-01

92

Separation of Oil from Wastewater by Air Flotation  

Microsoft Academic Search

\\u000a Air flotation, in all its variations, is an efficient way to extract oil from wastewater. If the wastewater is chemically\\u000a pretreated to break the oil emulsions, air flotation units are capable of removing most of the emulsified oil in addition\\u000a to the free oil. This chapter covers various flotation techniques to achieve oil\\/water separation. Flotation processes include\\u000a electroflotation, dissolved air

Gary F. Bennett; Nazih K. Shammas

93

Role of hydrodynamic cavitation in fine particle flotation  

Microsoft Academic Search

High energy dissipation, high feed velocity and relatively high feed pressures have been used in some recently developed flotation cells to enhance fine particle flotation. One contributing factor to the high flotation kinetics demonstrated in these new cells may be in-situ bubble formation by hydrodynamic cavitation on hydrophobic particles. This could induce particle aggregation through gas nucleus bridging with the

Z. A. Zhou; Zhenghe Xu; J. A. Finch; H. Hu; S. R. Rao

1997-01-01

94

Modelling of froth transportation in industrial flotation cells  

Microsoft Academic Search

Modelling of froth transportation, as part of modelling of froth recovery, provides a scale-up procedure for flotation cell design. It can also assist in improving control of flotation operation. Mathematical models of froth velocity on the surface and froth residence time distribution in a cylindrical tank flotation cell are proposed, based on mass balance principle of the air entering the

X. Zheng; J. P. Franzidis; E. Manlapig

2004-01-01

95

ReefBase: A Global Information System on Coral Reefs  

NSDL National Science Digital Library

ReefBase, a comprehensive Web portal for information on coral reefs, is presented by the World Fish Center based in Malaysia. Intended for use by reef managers, scientists, and the general public, ReefBase aims to "facilitate better understanding of the interdependence between humans and coral reefs, in order to benefit management and conservation efforts of these important resources." ReefBase provides information on coastal and marine resources, coral reef threats, resource management practices, maps and photos, references, and more. Users can quickly search for information organized by country or territory using a convenient dropdown menu. ReefBase is frequently updated; one recent addition is a status report for coral reefs of the southwestern Indian Ocean.

Noordeloos, Machiel E.; Oliver, J.

96

Flotation of cadmium-loaded biomass  

SciTech Connect

Biosorption of heavy metal ions such as Cd[sup 2+] by dead biomass has been recognized as a potential alternative to existing removal technologies applied to wastewater treatment. Two bacterial strains were studied in the laboratory, Streptomyces griseus and S. clavuligerus, an industrial by-product. Both washed and unwashed samples were examined. Foam flotation is proposed in this work as the separation stage following biosorption. Effective biomass separation was conducted in the presence of a frother, ethanol. The pH of the solution was a crucial parameter for flotation and also for metal binding. Other basic parameters of flotation examined were the initial cadmium concentration in the dilute aqueous solution and the quantity of biomass used. A study of [zeta]-potential measurements of the actinomycetes was carried out under the conditions used in the separation; surface tension was also measured. These provided useful information on the process.

Matis, K.A.; Zouboulis, A.I. (Aristotle Univ., Thessaloniki (Greece). Chemical Technology Div.)

1994-07-01

97

Utilization of flotation wastes of copper slag as raw material in cement production.  

PubMed

Copper slag wastes, even if treated via processes such as flotation for metal recovery, still contain heavy metals with hazardous properties posing environmental risks for disposal. This study reports the potential use of flotation waste of a copper slag (FWCS) as iron source in the production of Portland cement clinker. The FWCS appears a suitable raw material as iron source containing >59% Fe(2)O(3) mainly in the form of fayalite (Fe(2)SiO(4)) and magnetite (Fe(3)O(4)). The clinker products obtained using the FWCS from the industrial scale trial operations over a 4-month period were characterised for the conformity of its chemical composition and the physico-mechanical performance of the resultant cement products was evaluated. The data collected for the clinker products produced using an iron ore, which is currently used as the cement raw material were also included for comparison. The results have shown that the chemical compositions of all the clinker products including those of FWCS are typical of a Portland cement clinker. The mechanical performance of the standard mortars prepared from the FWCS clinkers were found to be similar to those from the iron ore clinkers with the desired specifications for the industrial cements e.g. CEM I type cements. Furthermore, the leachability tests (TCLP and SPLP) have revealed that the mortar samples obtained from the FWCS clinkers present no environmental problems while the FWCS could act as the potential source of heavy metal contamination. These findings suggest that flotation wastes of copper slag (FWCS) can be readily utilised as cement raw material due to its availability in large quantities at low cost with the further significant benefits for waste management/environmental practices of the FWCS and the reduced production and processing costs for cement raw materials. PMID:18384950

Alp, I; Deveci, H; Süngün, H

2008-11-30

98

Nanobubble generation and its applications in froth flotation (part IV): mechanical cells and specially designed column flotation of coal  

Microsoft Academic Search

Coal is the world's most abundant fossil fuel. Coal froth flotation is a widely used cleaning process to separate coal from mineral impurities. Flotation of coarse coal particles, ultrafine coal particles and oxidized coal particles is well known to be difficult and complex. In this paper, the nanobubbles' effects on the flotation of the varying particle size, particle density and

Maoming FAN; Daniel TAO; Rick HONAKER; Zhenfu LUO

2010-01-01

99

Effect of particle fineness on the finely disseminated iron ore for beneficiation  

NASA Astrophysics Data System (ADS)

This paper focused on Oolitic hematite ore which consists of extremely unequal disseminated particles that are fine-grained and easy to become muddy, It presents the effect of particle fineness, roasting temperature and roasting time and other variables on the beneficiation of this ore. The effect of particle fineness on the concentrate quality was also studied after magnetic roasting, the so-called process of ``magnetic roasting-stage grinding-low intensity magnetic separation-cationic reverse flotation'' was adopted to treat the raw ore under various experimental conditions including particle fineness, roasting temperature and roasting time, etc. it is found the concentrate grade of TFe of raw ore can be increased from 48.32%(original) to 61.30% at a recovery rate of 80.73%. Results show that the effect of particle fineness on mineral processing indexes is significant.

Qiu, T. S.; Zhang, W. X.; Fang, X. H.; Gao, G. K.

2013-06-01

100

Australia's Great Barrier Reef  

NASA Technical Reports Server (NTRS)

The Great Barrier Reef extends for 2,000 kilometers along the northeastern coast of Australia. It is 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 acquired by the MISR instrument on August 26, 2000 (Terra orbit 3679), and shows part of the southern portion of the reef adjacent to the central Queensland coast. The width of the MISR swath is approximately 380 kilometers, with the reef clearly visible up to approximately 200 kilometers from the coast. It may be difficult to see the myriad details in the browse image, but if you retrieve the higher resolution version, a zoomed display reveals the spectacular structure of the many reefs.

The more northerly coastal area in this image shows the vast extent of sugar cane cultivation, this being the largest sugar producing area in Australia, centered on the city of Mackay. Other industries in the area include coal, cattle, dairying, timber, grain, seafood, and fruit. The large island off the most northerly part of the coast visible in this image is Whitsunday Island, with smaller islands and reefs extending southeast, parallel to the coast. These include some of the better known resort islands such as Hayman, Lindeman, Hamilton, and Brampton Islands.

Further south, just inland of the small semicircular bay near the right of the image, is Rockhampton, the largest city along the central Queensland coast, and the regional center for much of central Queensland. Rockhampton is just north of the Tropic of Capricorn. Its hinterland is a rich pastoral, agricultural, and mining region.

MISR was built and is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Office of Earth Science, Washington, DC. The Terra satellite is managed by NASA's Goddard Space Flight Center, Greenbelt, MD. JPL is a division of the California Institute of Technology.

2001-01-01

101

Revisiting coral reef connectivity  

Microsoft Academic Search

A large river plume generated by anomalous precipitation and oceanic circulation associated with Hurricane Mitch was detected off Honduras in October 1998 using SeaWiFS ocean color images. This event provides the background for analyzing connectivity between coral reefs and land in the Meso-American reef system. We discuss the potential implications of such short-term events for disease propagation and nutrification, and

S. Andréfouët; P. Mumby; M. McField; C. Hu; F. Muller-Karger

2002-01-01

102

Amazing Reef: Moviemaker  

NSDL National Science Digital Library

In this movie-making interactive, learners can make an animated film about life on a coral reef. Learners choose an exciting story, cast colorful characters, and animate the movie themselves. They then add music and titles to complete the movie. Learners can even keep the movie by downloading it to their own computer. Learners can make up to four movies relating to survival, symbiosis, habitat, and predator/prey relationships in the Philippines Tropical Coral Reef.

Aquarium, Shedd; Educational Web Adventures (Eduweb)

2006-01-01

103

Purification of Trona Ores.  

National Technical Information Service (NTIS)

The present invention is a trona concentrate and a process for floating gangue material from trona ore that comprises forming an emulsion, conditioning the trona ore at a high solids content in a saturated trona suspension, and then floating and removing ...

J. D. Miller X. Wang M. Li

2005-01-01

104

Alternative Methods for Flotation Seat Cushion Use.  

National Technical Information Service (NTIS)

Alternative methods of using flotation seat cushions for water crash survivors were identified at the Civil Aeromedical Institute (CAMI). These methods, tested in the CAMI survival tank and a theme park wave pool were: (1) two people facing each other, ho...

G. E. Funkhouser M. H. George

1995-01-01

105

Flotation techniques for oily water treatment.  

PubMed

The aim of this work is to develop alternative techniques for the treatment of waters heavily contaminated by oil. Furthermore, the treatment system should achieve high removal efficiencies even under unfavorable conditions, when oil is finely dispersed in the water phase and oil droplet sizes range from 5-30 mm and concentrations are between 100 and 300 mg l(-1). The first experiments were carried out in an induced air flotation system where a flotation column performance was evaluated in batch and continuous operation. The second system investigated in this work focused on the association of centrifugal separation in a hydrocyclone and the flotation operation. The considered system is characterized by the association of these two processes, resulting the set-up in a compact unit (centrifugal flotation system). The bubbles generation and the droplet-bubble contact are performed through a gas-liquid ejector, while the separation of the phase rich in oil (froth phase) is promoted by a hydrocyclone. In both systems, it was possible to reduce the chemical demand of oxygen by more than 85% and the oil concentration of an emulsion containing droplets with sizes between 10 and 20 mm, using Polyacrilamide as destabilizing agent. PMID:12916838

Melo, M V; Sant'anna, G L; Massarani, G

2003-07-01

106

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

107

The Barrier Reef sediment apron: Tobacco Reef, Belize  

Microsoft Academic Search

Sedimentological and biological surveys of the back-reef sediment apron of Tobacco Reef, a continuous segment of the Belizean Barrier Reef, reveal five distinct biogeological zones: (1) coralline-coral-Dictyota pavement, (2) Turbinaria-Sargassum rubble, (3) Laurencia-Acanthophora sand and gravel, (4) bare sand and 95 Thalassia sand. These zones parallel the entire 9-km reef. The distribution of these zones is related to the spatial

Ian G. Macintyre; Richard R. Graus; Peter N. Reinthal; Mark M. Littler; Diane S. Littler

1987-01-01

108

Carbonate Production by Coral Reefs.  

National Technical Information Service (NTIS)

In the paper, the authors first create hypothetical models of coral reefs, based upon carbonate production estimates for individual organisms; then they compare the models with what is known about real reef communities and their geologic histories. The di...

K. E. Chave S. V. Smith K. J. Roy

1971-01-01

109

Shale-oil-recovery systems incorporating ore beneficiation. Final report.  

SciTech Connect

This study analyzed the recovery of oil from oil shale by use of proposed systems which incorporate beneficiation of the shale ore (that is concentration of the kerogen before the oil-recovery step). The objective was to identify systems which could be more attractive than conventional surface retorting of ore. No experimental work was carried out. The systems analyzed consisted of beneficiation methods which could increase kerogen concentrations by at least four-fold. Potentially attractive low-enrichment methods such as density separation were not examined. The technical alternatives considered were bounded by the secondary crusher as input and raw shale oil as output. A sequence of ball milling, froth flotation, and retorting concentrate is not attractive for Western shales compared to conventional ore retorting; transporting the concentrate to another location for retorting reduces air emissions in the ore region but cost reduction is questionable. The high capital and energy cost s results largely from the ball milling step which is very inefficient. Major improvements in comminution seem achievable through research and such improvements, plus confirmation of other assumptions, could make high-enrichment beneficiation competitive with conventional processing. 27 figures, 23 tables.

Weiss, M.A.; Klumpar, I.V.; Peterson, C.R.; Ring, T.A.

1982-10-01

110

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

111

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.

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

112

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

113

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.

114

Coral reef resilience through biodiversity  

USGS Publications Warehouse

Irrefutable evidence of coral reef degradation worldwide and increasing pressure from rising seawater temperatures and ocean acidification associated with climate change have led to a focus on reef resilience and a call to “manage” coral reefs for resilience. Ideally, global action to reduce emission of carbon dioxide and other greenhouse gases will be accompanied by local action. Effective management requires reduction of local stressors, identification of the characteristics of resilient reefs, and design of marine protected area networks that include potentially resilient reefs. Future research is needed on how stressors interact, on how climate change will affect corals, fish, and other reef organisms as well as overall biodiversity, and on basic ecological processes such as connectivity. Not all reef species and reefs will respond similarly to local and global stressors. Because reef-building corals and other organisms have some potential to adapt to environmental changes, coral reefs will likely persist in spite of the unprecedented combination of stressors currently affecting them. The biodiversity of coral reefs is the basis for their remarkable beauty and for the benefits they provide to society. The extraordinary complexity of these ecosystems makes it both more difficult to predict their future and more likely they will have a future.

Rogers, Caroline S.

2013-01-01

115

Flotation of marine microalgae: effect of algal hydrophobicity.  

PubMed

This study aims to understand the underlying reasons for the poor flotation response of marine microalgae. The flotation performance and hydrophobicity of a freshwater microalga (Chlorella sp. BR2) were compared to those of a marine microalga (Tetraselmis sp. M8) at different salinities in the presence of a cationic collector, tetradecyl trimethylammonium bromide. It was found that microalgal hydrophobicity played a more important role than salinity in determining the flotation performance. PMID:22858117

Garg, Sourabh; Li, Yan; Wang, Liguang; Schenk, Peer M

2012-10-01

116

The evolution of reef communities  

SciTech Connect

This book discusses the composition, structure, occurrence, and changes in reefs during the past 2 billion years. It emphasizes the functional roles of major groups (guilds) of reef-building, reef-destroying, and reed-dwelling organisms in the most complex of all marine communities. A structural model, based on modern reef guilds, is developed. Then the functional roles of each major reef-building higher biologic taxon (algae, sponges, coral, etc.) is determined, and, on this basis, each such taxon is assigned to a reef community guild. Next, the authors traces the geologic history and guild assignment of each major taxon through geologic time. The final chapter establishes a succession of ten major reef community types, and considers their extinction and recovery in the light of modern theories of cosmic and earthly events.

Fagerstrom, J.A.

1987-01-01

117

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

118

Electrocoagulation–flotation process for algae removal  

Microsoft Academic Search

Algae in surface water have been a long-term issue all over the world, due to their adverse influence on drinking water treatment process as well as drinking water quality. The algae removal by electro-coagulation–flotation (ECF) technology was investigated in this paper. The results indicated that aluminum was an excellent electrode material for algae removal as compared with iron. The optimal

Shanshan Gao; Jixian Yang; Jiayu Tian; Fang Ma; Gang Tu; Maoan Du

2010-01-01

119

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

120

Advanced physical fine coal cleaning microbubble flotation. Topical report No. 1. GHH-Bergbau Forschung microbubble coal flotation machine  

SciTech Connect

In conventional coal flotation, it is usual to use mechanically agitated cells. The agitator generates the air bubbles, mixes the slurry and air bubbles to bring about ''bubble-particle'' collisions. The average bubble size ranges between 500 and 1000 micrometers in diameter. Conventional flotation suffers from the following disadvantages: poor recovery with fine particles below 140 mesh due to inadequate bubble-particle encounter, or poor collision efficiency; comtamination of concentrates due to physical entrapment of ash particles in the froth; and loss of yield due to coal dropping off from the bubbles due to the agitated environment in the cell. The GHH-Bergbau Forschung (GHH-BF) microbubble flotation unit addresses the above noted drawbacks of conventional flotation and more effecitvely than other microbubble flotation systems. The innovations introduced by the GHH-BF unit in coal flotation, which are particularly relevant to the production of ultra clean coal, are briefly discussed. 1 ref., 1 fig.

Gagnon, A.; Chari, M.V.

1985-12-12

121

[Assessment of schemes for sewage purification from petroleum products, by using various flotation methods].  

PubMed

Petroleum products are the most common pollutants in petroleum refinery wastewater and are freed from the latter by flotation that is one of the most frequently applied physicochemical methods. The existing petroleum refinery OAO "Angara Petroleum Company" scheme for sewage purification from petroleum products, by using pressure flotation and proposed as a competitive purification scheme by applying electrical and impeller flotations underwent a comparative ecologoeconomic analysis. The use of electrical flotation instead of pressure flotation and that of an impeller flotation-electrical flotation system instead of a mechanical purification-pressure flotation one can considerably lower the concentration of petroleum products at the wastewater outlet into the Angara river. PMID:20491264

Zabuga, G A; Filippova, T M; Sivkov, A A

2010-01-01

122

Rivers, runoff, and reefs  

NASA Astrophysics Data System (ADS)

The role of terrigenous sediment in controlling the occurrence of coral reef ecosystems is qualitatively understood and has been studied at local scales, but has not been systematically evaluated on a global-to-regional scale. Current concerns about degradation of reef environments and alteration of the hydrologic and sediment cycles place the issue at a focal point of multiple environmental concerns. We use a geospatial clustering of a coastal zone database of river and local runoff identified with 0.5° grid cells to identify areas of high potential runoff effects, and combine this with a database of reported coral reef locations. Coastal cells with high runoff values are much less likely to contain reefs than low runoff cells and GIS buffer analysis demonstrates that this inhibition extends to offshore ocean cells as well. This analysis does not uniquely define the effects of sediment, since salinity, nutrients, and contaminants are potentially confounding variables also associated with runoff. However, sediment effects are likely to be a major factor and a basis is provided for extending the study to higher resolution with more specific variables.

McLaughlin, C. J.; Smith, C. A.; Buddemeier, R. W.; Bartley, J. D.; Maxwell, B. A.

2003-10-01

123

Reefs since Columbus  

Microsoft Academic Search

History shows that Caribbean coastal ecosystems were severely degraded long before ecologists began to study them. Large vertebrates such as the green turtle, hawksbill turtle, manatee and extinct Caribbean monk seal were decimated by about 1800 in the central and northern Caribbean, and by 1990 elsewhere. Subsistence over-fishing subsequently decimated reef fish populations. Local fisheries accounted for a small fraction

J. B. C. Jackson

1997-01-01

124

Coral Reef Biological Criteria  

EPA Science Inventory

Coral reefs worldwide are experiencing decline from a variety of stressors. Some important stressors are land-based sources of pollution and human activities in the coastal zone. However, few tools are available to offset the impact of these stressors. The Clean Water Act (CWA...

125

Create a Coral Reef  

NSDL National Science Digital Library

Educator Amy O'Donnell from the American Museum of Natural History guides learners to create a diorama of a coral reef. Learners will use craft skills to transform household materials into simulated brain coral, sea fans, sea anemones, and a sponge. This resource contains background information about coral and the use of dioramas in museums. Also includes extension ideas.

History, American M.

2012-06-26

126

CORAL REEF BIOCRITERIA  

EPA Science Inventory

Coral reefs worldwide are experiencing the greatest decline of their known existence and few tools are available to offset the growing impacts of human coastal and watershed activities. Biocriteria are a potentially effective means to evaluate and restore impaired waters, but are...

127

The Coral Reef Ecosystem  

NSDL National Science Digital Library

Students examine a coral reef ecosystem to learn about its living and non-living parts and how they interact. They apply what they have learned to explore the world's biomes, including how the animals in each are adapted to their environment.

Foundation, Wgbh E.

2007-04-19

128

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

129

The Barrier Reef sediment apron: Tobacco Reef, Belize  

NASA Astrophysics Data System (ADS)

Sedimentological and biological surveys of the back-reef sediment apron of Tobacco Reef, a continuous segment of the Belizean Barrier Reef, reveal five distinct biogeological zones: (1) coralline-coral- Dictyota pavement, (2) Turbinaria-Sargassum rubble, (3) Laurencia-Acanthophora sand and gravel, (4) bare sand and 95 Thalassia sand. These zones parallel the entire 9-km reef. The distribution of these zones is related to the spatial patterns of fish herbivory, the size of bottom sediments, and the stability of the substrate. Sedimentological and hydrodynamic studies indicate that most of the sediments in this area are transported from the reef crest and fore reef during periods of storm or hurricane activity and that their size distribution is largely the result of differential transport by high bottom-water velocities during those periods.

MacIntyre, Ian G.; Graus, Richard R.; Reinthal, Peter N.; Littler, Mark M.; Littler, Diane S.

1987-07-01

130

Ecological intereactions of reef building corals  

EPA Science Inventory

Coral reefs are very important marine ecosystems because they support tremendous biodiversity and reefs are critical economic resources many coastal nations. Tropical reef structures are largely built by stony corals. This presentation provides background on basic coral biology t...

131

26. NORTHERN VIEW OF ORE YARD WITH ORE BRIDGES IN ...  

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

26. NORTHERN VIEW OF ORE YARD WITH ORE BRIDGES IN THE BACKGROUND. BLAST FURNACES ALONG THE RIGHT SIDE. (Martin Stupich) - U.S. Steel Duquesne Works, Blast Furnace Plant, Along Monongahela River, Duquesne, Allegheny County, PA

132

Coral Reef Protection: A Watershed Approach  

NSDL National Science Digital Library

EPA's home page on coral reef protection activities, including The International Coral Reef Initiative, and The Coral Reef Symposium. A tremendous resource for educators interested in coral reef basics through advanced topics such as coral reef ecology and legislation. Site includes peer-reviewed journal articles, factsheets, maps, and video. The Links section is packed with extensive coral reef information sites covering international and domestic initiatives, research, and even a section for kids and teachers.

133

International Society for Reef Studies  

NSDL National Science Digital Library

Located within the Florida Institute of Technology, the International Society for Reef Studies (ISRS) was founded in 1980, and is designed to disseminate its findings on both living and fossil coral reefs to fellow scholars around the globe and the general public. Before delving into the main site, visitors will want to look through the ISRS in-house publication "Reef Encounters" to get a sense of the various projects the organization is currently working on, and of course, to read brief summaries of its research findings. Of course, for those who already are passionate about coral reefs, there is also a link to sign up for the NOAA "Coral List" forum. The resources section of the site is another good place to look for outside Web resources on other coral reef societies, marine laboratories, and government sites that contain materials on coral reefs and marine biology.

134

Cross flow cyclonic flotation column for coal and minerals beneficiation  

Microsoft Academic Search

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

Ralph W. Lai; Robert A. Patton

2000-01-01

135

Cross flow cyclonic flotation column for coal and minerals beneficiation  

Microsoft Academic Search

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

R. W. Lai; R. A. Patton

2000-01-01

136

Cross flow flotation column for coal and minerals beneficiation  

Microsoft Academic Search

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

Ralph W. Lai; Robert A. Patton

1997-01-01

137

Process for coal beneficiation by froth flotation employing pretreated water  

Microsoft Academic Search

This patent describes a process for the beneficiation of coal by froth flotation comprising surface treating particulate coal with a polymerizable monomer, a polymerization catalyst and a liquid organic carrier thereby rendering the particulate coal hydrophobic and oleophilic. The surface treated particulate coal is also introduced to a froth flotation vessel containing a water wash medium thereby resulting in a

McGarry

1986-01-01

138

Surface chemicals concepts of flotation de-inking  

Microsoft Academic Search

This review outlines the important parameters, which influence the flotation de-inking and discusses the surface chemical aspects of the process. Although, it has been established increasing temperature and pH facilitate the release of ink particles from the fibre during pulping (prior to flotation), it has not yet been completely established to what extent these parameters increase or decrease the efficiency

Katarina Theander; Robert J Pugh

2004-01-01

139

FOAM FLOTATION TREATMENT OF INDUSTRIAL WASTEWATERS: LABORATORY AND PILOT SCALE  

EPA Science Inventory

A floc foam flotation pilot plant reduced lead and zinc in dilute solution to very low concentrations. The results suggest a number of design improvements. A simple diffusion model does not adequately describe axial dispersion at high column leadings. The floc foam flotation of z...

140

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

141

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

142

Triassic Reefs of the Tethys  

Microsoft Academic Search

\\u000a The evolution of Triassic reefs started with a long-lasting global crisis of the metazoan reef ecosystem after the Permian—Triassic\\u000a mass extinction (about 12 Ma), followed by a relatively rapid recovery during the Middle Triassic. Reef systems were differentiated\\u000a during the Upper Triassic but were severely affected by a global crisis at the Triassic—Jurasic boundary. The present contribution\\u000a is focused on

Erik Flügel; Baba Senowbari-Daryan

143

Spatial Resilience of Coral Reefs  

Microsoft Academic Search

There have been several earlier studies that addressed the influence of natural disturbance regimes on coral reefs. Humans\\u000a alter natural disturbance regimes, introduce new stressors, and modify background conditions of reefs. We focus on how coral\\u000a reef ecosystems relate to disturbance in an increasingly human-dominated environment. The concept of ecosystem resilience—that\\u000a is, the capacity of complex systems with multiple stable

Magnus Nyström; Carl Folke

2001-01-01

144

Coral Reefs in Hot Water  

NSDL National Science Digital Library

In this activity, student teams identify the locations of coral reefs around the world, examine infrared satellite images of the Earth, and research the impacts that are threatening the survival of coral reefs. Each team creates a short oral presentation describing the coral reef they have researched. Students then plot on a composite map the locations where coral bleaching is occurring. Student worksheets, a teacher guide, and assessment rubric are included. This activity is part of Coastal Areas: Coral Reefs in Hot Water, part of the lesson series, The Potential Consequences of Climate Variability and Change.

145

Advanced physical fine coal cleaning microbubble flotation. Topical report No. 1. GHH-Bergbau Forschung microbubble coal flotation machine  

Microsoft Academic Search

In conventional coal flotation, it is usual to use mechanically agitated cells. The agitator generates the air bubbles, mixes the slurry and air bubbles to bring about ''bubble-particle'' collisions. The average bubble size ranges between 500 and 1000 micrometers in diameter. Conventional flotation suffers from the following disadvantages: poor recovery with fine particles below 140 mesh due to inadequate bubble-particle

A. Gagnon; M. V. Chari

1985-01-01

146

Rivers, runoff, and reefs  

Microsoft Academic Search

Theroleofterrigenoussedimentincontrollingtheoccurrenceofcoralreefecosystemsisqualitatively understoodandhasbeen studied atlocal scales,but hasnotbeen systematically evaluatedonaglobal-to-regional scale.Current concernsaboutdegradation ofreefenvironments andalteration ofthe hydrologicandsedimentcyclesplacetheissueatafocalpointofmultiple environmental concerns. We use a geospatial clustering of a coastal zone database of river and local runoff identified with 0.5j grid cells to identify areas of high potential runoff effects, and combine this with a database of reported coral reef locations. Coastal cells with high runoff

C. J. McLaughlin; C. A. Smith; R. W. Buddemeier; J. D. Bartley; B. A. Maxwell

147

The sensitivity of direct faecal examination, direct faecal flotation, modified centrifugal faecal flotation and centrifugal sedimentation/flotation in the diagnosis of canine spirocercosis.  

PubMed

Several faecal examination techniques have shown variable sensitivity in demonstrating Spirocerca lupi (S. lupi) eggs. The objective of this study was to determine which faecal examination technique, including a novel modified centrifugal flotation technique, was most sensitive to diagnose spirocercosis. Ten coproscopic examinations were performed on faeces collected from 33 dogs confirmed endoscopically to have spirocercosis. The tests included a direct faecal examination, a faecal sedimentation/flotation test, 4 direct faecal flotations and 4 modified faecal centrifugal flotations. These latter 2 flotation tests utilised 4 different faecal flotation solutions: NaNO3 (SG 1.22), MgSO4 (SG 1.29), ZnSO4 (SG 1.30) and sugar (SG 1.27). The sensitivity of the tests ranged between 42% and 67%, with the NaNO3 solution showing the highest sensitivity in both the direct and modified-centrifugal flotations. The modified NaNO3 centrifugal method ranked 1st with the highest mean egg count (45.24 +/- 83), and was superior (i.e. higher egg count) and significantly different (P < 0.05) compared with the routine saturated sugar, ZnSO4 and MgSO4 flotation methods. The routine NaNO3 flotation method was also superior and significantly different (P < 0.05) compared with the routine ZnSO4 and MgSO4 flotation methods. Fifteen per cent (n = 5) of dogs had neoplastic oesophageal nodules and a further 18% (n = 6) had both neoplastic and non-neoplastic nodules. S. lupi eggs were demonstrated in 40% of dogs with neoplastic nodules only and 72.9% of the dogs with non-neoplastic nodules. The mean egg count in the non-neoplastic group (61) was statistically greater (P = 0.02) than that of the neoplastic group (1). The results show that faecal examination using a NaNO3 solution is the most sensitive in the diagnosis of spirocercosis. The modified centrifugal flotation faecal method using this solution has the highest egg count. The study also found that dogs with neoplastic nodules shed significantly fewer eggs than dogs with non-neoplastic nodules. PMID:22135918

Christie, J; Schwan, E V; Bodenstein, L L; Sommerville, J E M; van der Merwe, L L

2011-06-01

148

Confronting the coral reef crisis  

Microsoft Academic Search

The worldwide decline of coral reefs calls for an urgent reassessment of current management practices. Confronting large-scale crises requires a major scaling-up of management efforts based on an improved understanding of the ecological processes that underlie reef resilience. Managing for improved resilience, incorporating the role of human activity in shaping ecosystems, provides a basis for coping with uncertainty, future changes

T. P. Hughes; C. Folke; M. Nyström; D. R. Bellwood

2004-01-01

149

Development of Artificial Oyster Reefs.  

National Technical Information Service (NTIS)

One hundred fourteen acres of public oyster reefs were constructed at an average cost of $1,867/acre in Bay, Brevard, Franklin, Wakulla, and Walton Counties, Florida. These reefs were constructed using 402,244 bushels of shucked Callico scallop shell, and...

W. K. Whitfield

1978-01-01

150

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

151

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.

152

Spectral discrimination of coral reef bottom types  

Microsoft Academic Search

Degradation of coral reefs is a major environmental problem worldwide. There is a strong management need for cost-effective assessment of environmental health and reef conditions over large regions in remote areas. Remote sensing could be an ideal tool for monitoring coral reefs and related ecosystems in cases where different coral reef substrates are spectrally resolvable. The aim of the present

T. Kutser; W. Skirving; J. Parslow; L. Clementson; T. Done; M. Wakeford; I. Miller

2001-01-01

153

The genesis of ores  

SciTech Connect

Human history and technology have been shaped by metals. How did they become concentrated in minable deposits located so conveniently near the earth's surface The author explains the mechanisms of fluid transport-by magma, water and even air and wind-responsible for the chemical and physical interactions that created bodies of metallic ores throughout geologic history. From their formation to their modification at the surface of the earth, ore deposits are geologically transitory and reflect dynamic processes within the earth as well as atmospheric and climatic influences on hydrologic systems. As highly reactive supracrustal systems, they then serve as geochemical sensors providing a powerful record and set of tracer elements for deducing the history, transport paths and forces operative in the crust.

Brimhall, G. (Univ. of California, Berkeley (USA))

1991-05-01

154

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

155

The International Coral Reef Information Network  

NSDL National Science Digital Library

This extensive site was originally created to support coral reef conservation by the International Coral Reef Initiative (ICRI). The site serves to provide general coral reef information, tools and resources, and a central coral reef communications and network hub. The site also provides a library which houses descriptions of brochures, books, videos and other items suitable for coral reef awareness and education efforts. Some publications are available for download directly from this site, while others are available for purchase.

International Coral Reef Action Network (ICRAN)

156

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

157

Flotation properties of high-molecular alkylarylsulfonates  

Microsoft Academic Search

Conclusions  \\u000a \\u000a \\u000a \\u000a 1. \\u000a \\u000a The flotation properties of individual high-molecular C22?C24 alkylarylsulfonates depend markedly on the structure of their hydrocarbon radicals.\\u000a \\u000a \\u000a \\u000a \\u000a 2. \\u000a \\u000a Sulfonates containing normal aliphatic saturated hydrocarbon radicals (straight-chain sulfonates) exhibit high sorption values\\u000a on minerals and are good collectors.\\u000a \\u000a \\u000a \\u000a \\u000a 3. \\u000a \\u000a With the presence of branched hydrocarbon radicals in the sulfonate molecules (branched sulfonates), their sorption on the\\u000a mineral and their

B. E. Chistyakov; N. A. Aleinikov; A. A. Petrov

1969-01-01

158

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.

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

2011-01-01

159

Flotation of coal using micro-bubbles and inorganic salts  

SciTech Connect

The results of two research projects supported by the US Department of Energy are reported. In the first, 32 different salts were tested in the flotation of -100 mesh bituminous coal. An arbitrary concentration of 0.07 moles/l was used and no other reagents were present. Results are quoted for sodium salts with various anions and sulphate salts with various cations. The rate of flotation was found to be considerably faster when salts were used rather than kerosene and Dowfroth as collector and frother. The mechanism of the process was investigated. In the second project, the use of micro-bubbles generated in the frother by several different techniques was investigated for the flotation of fine coal. Results are given for tests on -400 mesh coal under various conditions. Yields were found to be higher with conventional flotation, but the ash contents were much lower when using micro-bubbles.

Yoon, R.H.

1982-12-01

160

Screening/Flotation Treatment of Combined Sewer Overflows.  

National Technical Information Service (NTIS)

The report documents a study to develop a treatment system for combined sewer overflows. The processes of chemical oxidation, screening, dissolved-air flotation, and disinfection were evaluated in the laboratory. A 5 MGD demonstration system was designed,...

D. G. Mason M. K. Gupta

1972-01-01

161

Harvesting of Scenedesmus obliquus FSP-3 using dispersed ozone flotation.  

PubMed

The Scenedesmus obliquus FSP-3, a species with excellent potential for CO(2) capture and lipid production, was harvested using dispersed ozone flotation. While air aeration does not, ozone produces effective solid-liquid separation through flotation. Ozone dose applied for sufficient algal flotation is similar to those used in practical drinking waterworks. The algae removal rate, surface charge, and hydrophobicity of algal cells, and fluorescence characteristics and proteins and polysaccharides contents of algogenic organic matter (AOM) were determined during ozonation. Proteins released from tightly bound AOM are essential to modifying the hydrophobicity of bubble surfaces for easy cell attachment and to forming a top froth layer for collecting floating cells. Humic substances in the suspension scavenge dosed ozone that adversely affects ozone flotation efficiency of algal cells. PMID:20627550

Cheng, Ya-Ling; Juang, Yu-Chuan; Liao, Guan-Yu; Tsai, Pei-Wen; Ho, Shih-Hsin; Yeh, Kuei-Ling; Chen, Chun-Yen; Chang, Jo-Shu; Liu, Jhy-Chern; Chen, Wen-Ming; Lee, Duu-Jong

2011-01-01

162

Dissolved Air Flotation Treatment of Gulf Shrimp Cannery Wastewater.  

National Technical Information Service (NTIS)

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 coa...

A. J. Szabo F. R. Wilson L. F. LaFleur

1979-01-01

163

Removal of Humic Substances and Algae by Dissolved Air Flotation.  

National Technical Information Service (NTIS)

Dissolved air flotation (DAF) is used in place of conventional gravity settling as a means to separate low density floc particles from water. The following objectives were: (1) to compare DAF to conventional water treatment of coagulation-flocculation fol...

J. K. Edzwald J. P. Malley

1989-01-01

164

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

165

Foam Flotation Treatment of Industrial Wastewaters: Laboratory and Pilot Scale.  

National Technical Information Service (NTIS)

A floc foam flotation pilot plant reduced lead and zinc in dilute solution to very low concentrations. The results suggest a number of design improvements. A simple diffusion model does not adequately describe axial dispersion at high column leadings. The...

D. J. Wilson E. L. Thackston

1980-01-01

166

Upper Permian Capitan Reef  

SciTech Connect

A depositional and diagentic model for the Capitan reef complex (Late Permian, Guadalupian age) has evolved during more than 50 years of outcrop studies in the Guadalupe Mountains of west Texas and New Mexico. The model relates the shelf margin (Capitain Limestone) with equivalent shelf (in ascending order, Seven Rivers, Yates, and Tansill Formations) and basin (Bell Canyon Formation) strata. It has proved to be important in relating hydrocarbon distribution in shelf and basin strata in the Permian basin and has been important as an analog in numerous other basins. Detailed study of the northern rim of the Delaware basin, centering on a 4,800-ft core, has caused us to reevaluate the outcrop-defined depositional model for the Capitan shelf margin along the following themes. Geologic evolution. Progradation of the margin was not uniform throughout deposition of the Capitan as is portrayed in most reconstructions. Outcrop mapping and log correlations, in fact, show that 75% of the total basinward progradation of the Capitan occurred during deposition of the Seven Rivers Formation. This maximum progradation corresponds to back-reef carbonates largely devoid of siliciclastics, thick carbonate debris beds on the slope and basin edge, and thick siliclastics deposited in the basin. Depositional facies and diagenesis. The pisolithic shoal complex, the predominant feature marking the highest part of the shelf margin, was more laterally extensive than known from outcrop.

Harris, P.M.; Garber, R.A.; Grover, G.A.

1988-01-01

167

Miocene reef corals: A review  

SciTech Connect

Tectonic blockage in the Middle East of westward-flowing Tethys surface circulation during the latest Oligocene led to creation in the earliest Miocene of endemic Mediterranean, Western Atlantic-Caribbean, and Indo-Pacific realms. A great reduction in reef coral diversity from 60-80 Oligocene species to 25-35 early Miocene species occurred in the Western Atlantic-Caribbean and Mediterranean areas accompanied by a decrease in reef growth. A slower and less drastic change apparently occurred in the Indo-Pacific area. Early Miocene reef corals of the Western Atlantic-Caribbean comprise a transition between the cosmopolitan Oligocene fauna and its endemic mid-Miocene to modern counterpart. Although early Miocene reefs were dominated by a Porites-Montastrea assemblage, eastward flow of Pacific circulation brought with it ''exotic'' corals such as Coscinaraea and Pseudocolumnastrea. Also, many cosmopolitan genera persisted from the Oligocene. During the middle to late Miocene, most of the species still living on Holocene reefs evolved. As the Mediterranean basin became more restricted, there was a slow decline in reef corals from 20 - 25 species in the Aquitainian to less than five species in the Messinian. Eustatic lowstand led to the extinction of reef-building corals in the late Messinian. In the Indo-Pacific, Neogene evolution of reef corals was conservative. Excluding the Acroporidae and Seriatoporidae, most Holocene framework species had evolved by the middle Miocene. Interplay between regional tectonics and eustatic sea level changes led to extensive development of middle to late Miocene pinnacle reefs over the southwestern Pacific.

Frost, S.H.

1988-01-01

168

Cross flow cyclonic 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, R.W.; Patton, R.A.

2000-05-02

169

Remediation of metal-contaminated urban soil using flotation technique.  

PubMed

A soil washing process using froth flotation technique was evaluated for the removal of arsenic, cadmium, copper, lead, and zinc from a highly contaminated urban soil (brownfield) after crushing of the particle-size fractions >250microm. The metal contaminants were in particulate forms and distributed in all the particle-size fractions. The particle-by-particle study with SEM-EDS showed that Zn was mainly present as sphalerite (ZnS), whereas Cu and Pb were mainly speciated as various oxide/carbonate compounds. The influence of surfactant collector type (non-ionic and anionic), collector dosage, pulp pH, a chemical activation step (sulfidization), particle size, and process time on metal removal efficiency and flotation selectivity was studied. Satisfactory results in metal recovery (42-52%), flotation selectivity (concentration factor>2.5), and volume reduction (>80%) were obtained with anionic collector (potassium amyl xanthate). The transportation mechanisms involved in the separation process (i.e., the true flotation and the mechanical entrainment) were evaluated by the pulp chemistry, the metal speciation, the metal distribution in the particle-size fractions, and the separation selectivity indices of Zn/Ca and Zn/Fe. The investigations showed that a great proportion of metal-containing particles were recovered in the froth layer by entrainment mechanism rather than by true flotation process. The non-selective entrainment mechanism of the fine particles (<20 microm) caused a flotation selectivity drop, especially with a long flotation time (>5 min) and when a high collector dose is used. The intermediate particle-size fraction (20-125 microm) showed the best flotation selectivity. PMID:19959208

Dermont, G; Bergeron, M; Richer-Laflèche, M; Mercier, G

2010-02-01

170

Investigation of foam flotation and phase partitioning techniques  

NASA Technical Reports Server (NTRS)

The present status of foam flotation as a separation process is evaluated and limitations for cells and proteins are determined. Possible applications of foam flotation to separations in microgravity are discussed. Application of the fluid mechanical aspects of foam separation techniques is made to phase partitioning in order to investigate the viscous drag forces that may effect the partitioning of cells in a two phase poly(ethylene glycol) and dextran system.

Currin, B. L.

1985-01-01

171

Flocculation and Air Requirements for Dissolved Air Flotation  

Microsoft Academic Search

Bench-scale and pilot-plant studies were used to investigate the effects of flocculation time and floe size on the performance of dissolved air flotation and to determine air requirements for three different types of water supplies. The results show that long flocculation periods are not needed and suggest that floc particles of 10-30 ?m should be prepared for flotation. Two measures

James K. Edzwald; John P. Walsh; Gary S. Kaminski; Howard J. Dunn

1992-01-01

172

Coal desulfurization by bacterial treatment and column flotation. Final report  

SciTech Connect

A review of the literature showed that bacterial leaching, using the microorganism Thiobacillus ferrooxidans, was a very effective technique for removing pyrite from coal, as it could dissolve even the finest pyrite particles without the need for expensive reagents or extreme processing conditions. Unfortunately, bacterial leaching is also rather slow, and so the initial goal of this research was to decrease the leaching time as much as possible. However, this still left the bacteria needing approximately a week to remove half of the pyritic sulfur, and so a faster technique was sought. Since it had been reported in the literature that T. ferrooxidans could be used to depress the flotation of pyrite during froth flotation of coal, this was investigated further. By studying the recovery mechanisms of coal-pyrite in froth flotation, it was found that pyrite was being recovered by entrainment and by locking to coal particles, not by true flotation of hydrophobic pyrite. Therefore, no pyrite depressant could be of any significant benefit for keeping pyrite out of the coal froth product, and it was much more important to prevent entrainment from occurring. Countercurrent flotation columns were invented to essentially eliminate entrainment effects, by washing the froth and reducing mixing of the froth and tailings products. Existing flotation columns tend to be quite simple, and in order to give reasonable product quality they must be very tall (typically 30--45 feet). As a result, they have difficulty in handling the high froth volumes which occur in coal flotation, and are awkward to install in existing plants. The bulk of this project therefore concentrated on developing an improved coal flotation column, and testing it under actual plant conditions.

Kawatra, S.K. [Michigan Technological Univ., Houghton, MI (United States)

1994-06-01

173

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

174

Removal of fluoride from semiconductor wastewater by electrocoagulation–flotation  

Microsoft Academic Search

This work employs an anodic surfactant, sodium dodecyl sulfate (SDS), to improve the flotation performance of the electrocoagulation–flotation (ECF) process to treated fluoride containing semiconductor wastewater following calcium precipitation. The dissolved fluoride ions and CaF2 particles in the wastewater after calcium precipitation were effectively removed in the ECF process simultaneously. The dosage of SDS required for ECF was much less

C. Y. Hu; S. L. Lo; W. H. Kuan; Y. D. Lee

2005-01-01

175

Age of tilted reefs, Hawaii.  

USGS Publications Warehouse

Submerged carbonate reefs are preserved as a series of submarine terraces between Molokai and Hawaii along a 200-km span of the SE Hawaiian Ridge. Limestones from 2 of the terraces have been dated at 13 and 120 ka. Recognition that the terraces are tilted permits assignment of about a dozen terraces from 150 to 1300 m depth to 8 general reef platforms. These reefs were drowned by the combined effects of island subsidence and sea level rise at the end of successive glacial stages from 13 to 647 ka. The platforms are tilted 5 m/km SE toward the locus of volcanic centered on the island of Hawaii.-from Authors

Moore, J. G.; Campbell, J. F.

1987-01-01

176

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

177

Application of Dissolved Air Flotation in Biological Waste Treatment Plants (Primary Clarification, Secondary Clarification and Sludge Thickening), and Water Purification Plants.  

National Technical Information Service (NTIS)

Applications of dissolved air flotation (DAF) in a biological waste treatment plant as a primary clarifier (primary flotation), a secondary clarifier (secondary flotation), and a sludge thickener (flotation thickener) are studied and experimentally evalua...

M. Krofta L. K. Wang

1985-01-01

178

Nanobubble generation and its applications in froth flotation (part III): specially designed laboratory scale column flotation of phosphate  

Microsoft Academic Search

Froth flotation is used widely for upgrading raw phosphate. The flotation recovery of coarse phosphate (?1.18+0.425 mm) is much lower than that achieved on the ?0.425+0.15 mm size fraction. Enhanced recovery of coarse phosphate particles is of great economic and environmental importance for phosphate industry. In this investigation, four different phosphate samples were aquired, characterized and tested in a specially

Maoming FAN; Daniel TAO; Rick HONAKER; Zhenfu LUO

2010-01-01

179

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

180

Electronic Ore-Sorting Tests on Native Copper Ore.  

National Technical Information Service (NTIS)

The test program evaluated the use of belt and rotary sorters on various size and grade fractions of ore. Both plant-scale sorting and lab sorting tests were run. The plant sorting objectives were to determine the sortability of different ores and the eff...

J. K. Ahlness J. C. Kirchner

1980-01-01

181

Coral Reef Protection Implementation Plan.  

National Technical Information Service (NTIS)

This document identify policies and actions to implement the Department of Defense's responsibilities under Executive Order 13089 on Coral Reef Protection, and are a requirement of the interim Task Force policy titled 'Oversight of Agency Actions Affectin...

L. K. Lobel P. Lobel

2000-01-01

182

Commencement on a Coral Reef  

ERIC Educational Resources Information Center

Describes an environmental program in which sixteen students and three biology teachers from Northfield Mount Hermon School in Massachusetts spent two weeks examining the ecology of a Caribbean reef.. (JR)

Webster, Steven K.

1973-01-01

183

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.

184

The Revised Coral Reef Hypothesis  

Microsoft Academic Search

The original coral reef hypothesis stated that carbonate production by benthic biota on the world's shallow shelves substantially contributed to the buildup of atmospheric pCO2 during the last deglaciation. We have synthetized the literature on the world's reefs and new data on the distribution of the carbonate platforms (isolated banks and contintent-attached platforms). Strong production and resulting CO2 release started

A. Vecsei; W. H. Berger

2002-01-01

185

Lab 3: Building a Reef  

NSDL National Science Digital Library

During this lab, students learn about the life cycle of corals, including how they grow and reproduce. Students consider the chemistry of seawater and the importance of the symbiotic relationship between corals and zooxanthellae in the formation of coral reefs. They blow CO2 through calcium hydroxide (limewater) to model how respiration assists coral in precipitating calcium carbonate. Students also build on the coral polyp models they made in Lab 2 to demonstrate coral growth, reproduction, and reef formation.

186

Borehole Mining of Phosphate Ores.  

National Technical Information Service (NTIS)

This report presents the results of a technical, economic, and environmental feasibility study of phosphate ore recovery by the hydraulic borehole mining method. The experiments resulted in the recovery of 1,696 tons of ore from 3 boreholes during a 65-ho...

L. E. Scott

1981-01-01

187

Geomorphology of unique reefs on the western Canadian shelf: sponge reefs mapped by multibeam bathymetry  

Microsoft Academic Search

Multibeam imagery of siliceous sponge reefs (Hexactinellida, Hexactinosida) reveals the setting, form, and organization of five reef complexes on the western Canadian continental shelf. The reefs are built by framework skeleton sponges which trap clay-rich sediments resulting in a distinctive pattern of low intensity backscatter from the reefs that colonize more reflective glacial sediments of higher backscatter intensity. Bathymetry and

Kim W. Conway; J. Vaughn Barrie; Manfred Krautter

2005-01-01

188

Benthic microalgae in coral reef sediments of the southern Great Barrier Reef, Australia  

Microsoft Academic Search

The abundance and productivity of benthic microalgae in coral reef sediments are poorly known compared with other, more conspicuous (e.g. coral zooxanthellae, macroalgae) primary producers of coral reef habitats. A survey of the distribution, biomass, and productivity of benthic microalgae on a platform reef flat and in a cross-shelf transect in the southern Great Barrier Reef indicated that benthic microalgae

C. A. Heil; K. Chaston; A. Jones; P. Bird; B. Longstaff; S. Costanzo; W. C. Dennison

2004-01-01

189

Configuration of small patch reefs and population abundance of a resident reef fish in a complex coral reef landscape  

Microsoft Academic Search

Habitat use by the resident coral reef anemonefish, Amphiprion frenatus, was examined in the complex coral reef landscape of Shiraho Reef, Ishigaki Island, Okinawa, Japan, using an enlarged color\\u000a aerial photograph processed using image analysis software as an accurate field map. The anemonefish inhabit assemblages of\\u000a the host sea anemone, Entacmaea quadricolor (clonal type), which inhabit various patch reefs in

Akihisa Hattori; Miyako Kobayashi

2007-01-01

190

Role of the collecting agent sorption forms in the elementary act of flotation  

SciTech Connect

A new hypothesis of flotation is substantiated based on the well-known hypotheses, theoretical analysis of the elementary act, and experimental results. The hypothesis presented allows the processes of flotation activation, depression, and intensification to be explained and optimized.

Abramov, A.A. [Moscow State Mining University, Moscow (Russian Federation)

2005-02-01

191

Effect of Some Column Flotation Parameters on the Fine Concentration of Phosphate from Itataia, Brazil.  

National Technical Information Service (NTIS)

The present investigation aims, at a higher detail level, to identify, from systematic studies, the most important variables of the column flotation and also to check continuous flotation circuits ntegrating columns and mechanical cells to process the -10...

J. B. Reis

1987-01-01

192

46 CFR 169.741 - Personal flotation devices and ring life buoys.  

Code of Federal Regulations, 2013 CFR

... Personal flotation devices and ring life buoys. 169.741 Section 169.741 Shipping COAST GUARD, DEPARTMENT OF HOMELAND...Miscellaneous Systems, and Equipment Markings § 169.741 Personal flotation devices and ring life...

2013-10-01

193

Quantitative evaluation of environmental risks of flotation tailings from hydrothermal sulfidation-flotation process.  

PubMed

Floatation tailings (FT) are the main by-products of the hydrothermal sulfidation-flotation process. FT (FT1 and FT2) were obtained by treating two different neutralization sludges (NS) (NS1 and NS2). This paper quantitatively evaluated the environmental risks of heavy metals (Zn, Cd, Cu, Pb, and As) in FT versus NS. The total concentration and leaching rates (R 2) of heavy metals in FT were much lower than those in NS, demonstrating that the hydrothermal sulfidation-flotation process was able to effectively suppress the mobility and leachability of heavy metals. The BCR-three sequence leaching procedure of FT confirmed that all metals were transformed into more stable forms (residue and oxidizable forms) than were found that in NS. The potential ecological risk index indicated that the overall risks caused by heavy metals decreased significantly from 6627.59 and 7229.67 (very serious risk) in NS1 and NS2, respectively, to 80.26 and 76.27 (low risk) in FT1 and FT2, respectively. According to the risk assessment code, none of the heavy metals in FT posed significant risk to the natural environment except Zn (with low risk). In general, the risk of heavy metals in FT had been well controlled. PMID:23529403

Xie, Xian-De; Min, Xiao-Bo; Chai, Li-Yuan; Tang, Chong-Jian; Liang, Yan-Jie; Li, Mi; Ke, Yong; Chen, Jie; Wang, Yan

2013-09-01

194

A Night in the Coral Reef  

NSDL National Science Digital Library

Coral reefs are often portrayed as brightly lit, bustling underwater marvels full of colorful creatures. This video segment, adapted from NOVA, paints a different picture as it explores the nocturnal behavior of organisms in the reef.

Foundation, Wgbh E.

2007-04-19

195

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

196

Immobilization of copper flotation waste using red mud and clinoptilolite.  

PubMed

The flash smelting process has been used in the copper industry for a number of years and has replaced most of the reverberatory applications, known as conventional copper smelting processes. Copper smelters produce large amounts of copper slag or copper flotation waste and the dumping of these quantities of copper slag causes economic, environmental and space problems. The aim of this study was to perform a laboratory investigation to assess the feasibility of immobilizing the heavy metals contained in copper flotation waste. For this purpose, samples of copper flotation waste were immobilized with relatively small proportions of red mud and large proportions of clinoptilolite. The results of laboratory leaching demonstrate that addition of red mud and clinoptilolite to the copper flotation waste drastically reduced the heavy metal content in the effluent and the red mud performed better than clinoptilolite. This study also compared the leaching behaviour of metals in copper flotation waste by short-time extraction tests such as the toxicity characteristic leaching procedure (TCLP), deionized water (DI) and field leach test (FLT). The results of leach tests showed that the results of the FLT and DI methods were close and generally lower than those of the TCLP methods. PMID:18927060

Coruh, Semra

2008-10-01

197

Foraminiferal Assemblages on Sediment and Reef Rubble at Conch Reef, Florida USA  

Microsoft Academic Search

\\u000aForaminiferal Assemblages on Sediments and Reef Rubble\\u000aat Conch Reef, Florida USA\\u000aChristy Stephenson\\u000aBenthic foraminiferal assemblages are widely used to interpret responses of the benthic communities to environmental stresses. This study compares epibiotic foraminiferal assemblages, collected from reef rubble, with those from reef sediments. The study site, Conch Reef, is the site of the Aquarius Underwater Habitat research facility

Christy Michelle Stephenson

2011-01-01

198

Flotation behaviourof huntite (Mg3Ca(CO3)4) with anionic collectors  

Microsoft Academic Search

In this study, flotation properties of huntite as unusual carbonate mineral and the effects of modifying reagents on huntite were determined. Flotation behaviour and electrokinetic properties of huntite were determined in the presence of potassium oleate and Flotinor FS-2. The effects of common ions that are expected in flotation pulps such as, Mg2+ and Ca2+ were studied. The influences of

M. Olgaç KANGAL; Ali GÜNEY

199

Nanobubble generation and its applications in froth flotation (part II): fundamental study and theoretical analysis  

Microsoft Academic Search

Froth flotation is a commonly employed technology to improve the quality of raw coal and minerals. Coal and minerals particle size and surface hydrophobicity are two main parameters that affect three key steps in froth flotation process: particle-bubble collision, adhesion, and detachment. This paper fundamentally investigated the effects of nanobubble on coal and phosphate flotation. It has been found that

Maoming FAN; Daniel TAO; Rick HONAKER; Zhenfu LUO

2010-01-01

200

Flotation of sodium carbonate and sodium bicarbonate salts from their saturated brines  

Microsoft Academic Search

The flotation behavior of sodium carbonates and sodium bicarbonate has been studied with dodecyl amine hydrochloride (DAH) and sodium dodecyl sulfate (SDS) as part of a research program to evaluate the potential of flotation technology for use in the trona industry. Laboratory microflotation experiments generally show that flotation of sodium carbonate salts is possible at least to some extent with

O Ozcan; J. D Miller

2002-01-01

201

A compartment model for the mass transfer inside a conventional flotation cell  

Microsoft Academic Search

A model is developed by taking into account the simultaneous mechanisms of true flotation and entrainment in a conventional flotation cell. The total volume of the cell is divided into three compartments: pulp collection zone, pulp quiescent zone and froth region, with the mechanisms being modeled as occurring at the same time but originating at different places: true flotation from

O. N. Savassi

2005-01-01

202

Flotation separation of diaspore from kaolinite, pyrophyllite and illite using three cationic collectors  

Microsoft Academic Search

The effect of cationic groups on performance of 12-carbon chain collectors in flotation separation of diaspore from kaolinite, pyrophyllite and illite has been investigated by flotation tests and explained by density functional computations. The flotation test results indicated that the separation of diaspore from these aluminosilicate minerals was feasible at strong alkaline conditions by using cationic collectors, dodecylamine chloride (DDAC),

Hong Zhong; Guangyi Liu; Liuyin Xia; Yiping Lu; Yuehua Hu; Shenggui Zhao; Xinyang Yu

2008-01-01

203

A study of interactions and flotation of wolframite with octyl hydroxamate  

Microsoft Academic Search

The flotation of wolframite using sodium hydroxamate as collector was investigated. The collector-mineral interactions were studied by determining collector adsorption, measuring zeta potentials, acquiring infrared spectra and conducting solution chemistry calculations. A multilayer collector adsorption was determined to be necessary for effective flotation and the metal hydroxamate was identified as the major adsorbed species on wolframite. The optimal flotation condition

Y. Hu; D. Wang; Z. Xu

1997-01-01

204

Coral Reefs of St. Lucia, West Indies.  

National Technical Information Service (NTIS)

Coral reefs growing in the waters of St. Lucia appear to be in an early stage of development. They consist of two general types: (1) patch and platform reefs and (2) incipient fringing reefs. St. Lucia is the only coral island in the Caribbean that exhibi...

H. H. Roberts

1972-01-01

205

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

206

40 CFR 230.44 - Coral reefs.  

Code of Federal Regulations, 2010 CFR

... 24 2009-07-01 2009-07-01 false Coral reefs. 230.44 Section 230.44 Protection of...Impacts on Special Aquatic Sites § 230.44 Coral reefs. (a) Coral reefs consist of the skeletal deposit, usually...

2009-07-01

207

40 CFR 230.44 - Coral reefs.  

Code of Federal Regulations, 2010 CFR

... 24 2010-07-01 2010-07-01 false Coral reefs. 230.44 Section 230.44 Protection of...Impacts on Special Aquatic Sites § 230.44 Coral reefs. (a) Coral reefs consist of the skeletal deposit, usually...

2010-07-01

208

Lab 1: Coral Reefs, the Human View  

NSDL National Science Digital Library

Students are introduced to coral reef ecosystems and the importance of corals to humans. Students watch the IMAX film Coral Reef Adventure to experience the human view of coral reefs through the eyes of ocean explorers and underwater filmmakers Howard and Michele Hall. The students then use microscopes to examine coral and identify its features.

209

Nanoparticle flotation collectors III: the role of nanoparticle diameter.  

PubMed

The ability of polystyrene nanoparticles to promote glass bead flotation was measured as a function of nanoparticle diameter. In all cases, smaller nanoparticles were more effective flotation collectors, even when compared at constant nanoparticle number concentration. The superior performance of smaller particles was explained by two mechanisms, acting in parallel. First, smaller particles deposit more quickly giving more effective flotation in those cases where nanoparticle deposition kinetics is rate determining; the sensitivity of nanoparticle deposition rates to particle size was illustrated by kinetic measurements on a quartz crystal microbalance silica surface. Second, for a given coverage of nanoparticles on the glass beads, the mean distance between neighboring nanoparticle surfaces decreases with particle diameter. We propose that the expansion of the three phase contact line, after initial bead/bubble attachment, is favored with decreasing the distance between neighboring hydrophobic particles. PMID:22871900

Yang, Songtao; Pelton, Robert; Montgomery, Miles; Cui, Yuguo

2012-09-26

210

Ore metals through geologic history.  

PubMed

The ores of chromite, nickel, copper, and zinc show a wide distribution over geologic time, but those of iron, titanium, lead, uranium, gold, silver, molybdenum, tungsten, and tin are more restricted. Many of the limitations to specific time intervals are probably imposed by the evolving tectonic history of Earth interacting with the effects of the biomass on the evolution of the earth's s surface chemistry. Photosynthetic generation of free oxygen and "carbon" contributes significantlly to the diversity of redox potentials in both sedimentary and igneous-related processes of ore formation, influencing the selection of metals at the source, during transport, and at the site of ore deposition. PMID:17777763

Meyer, C

1985-03-22

211

Column flotation results at Powell Mountain Coal Company  

SciTech Connect

In 1989 a column flotation process was developed at the CAER, which enabled the economical recovery of coal fines from high-ash fine refuse. The laboratory design was expanded to commercial scale and installed at the Mayflower Coal Preparation Plant of Powell Mountain Coal Company in December, 1989. It has been in continuous operation there since that time. This article is a summary of the past two years' experiences with this applied technology, applicable dewatering tests and flotation tests results from the plant.

Peters, W.J. Parekh, B.K. (Powell Mountain Coal Co. (US))

1992-01-01

212

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

213

A deep reef in deep trouble  

USGS Publications Warehouse

The well-documented degradation of shallower reefs which are often closer to land and more vulnerable to pollution, sewage and other human-related stressors has led to the suggestion that deeper, more remote offshore reefs could possibly serve as sources of coral and fish larvae to replenish the shallower reefs. Yet, the distribution, status, and ecological roles of deep (>30 m) Caribbean reefs are not well known. In this report, an observation of a deep reef which has undergone a recent extensive loss of coral cover is presented. In stark contrast to the typical pattern of coral loss in shallow reefs, the deeper corals were most affected. This report is the first description of such a pattern of coral loss on a deep reef.

Menza, C.; Kendall, M.; Rogers, C.; Miller, J.

2007-01-01

214

NOAA Coral Reef Watch: Remote Sensing and Coral Reefs  

NSDL National Science Digital Library

Developed by a fifth grade teacher, the Remote Sensing and Coral Reefs curriculum includes lesson plans, which feature links to additional information, and PowerPoint presentations. Topics discussed include altimetry, phytoplankton and ocean color, symbiosis and coral anatomy, sea surface temperature and coral bleaching, and conservation. The lesson plans can be used in sequence or by themselves.

215

An evaluation of different models of water recovery in flotation  

Microsoft Academic Search

Water recovery is one of the key parameters in flotation modelling for the purposes of plant design and process control, as it determines the circulating flow and residence time in the individual process units in the plant and has a significant effect on entrainment and froth recovery. This paper reviews some of the water recovery models available in the literature,

X. Zheng; J. P. Franzidis; N. W. Johnson

2006-01-01

216

Electrokinetic behavior and flotation of kaolinite in CTAB solution  

Microsoft Academic Search

The electrokinetics and flotation behavior of kaolinite in cetyltrimethylammonium bromide (CTAB) solution were studied. The point of zero charge (PZC) of kaolinite is 4.3. The possible mode of CTAB adsorption on kaolinite is due to Coulombic and Van der Waals forces revealed by zeta-potential and FTIR measurements. The negative zeta potential of kaolinite and the adsorption of cationic collectors on

Y Hu; H Jiang; D Wang

2003-01-01

217

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

218

Separation of oil from water by dissolved air flotation  

Microsoft Academic Search

Synthetic industrial effluent was prepared by stabilising low concentrations of oil (Catenex 11, Shell, UK) in aqueous dispersion with a non-ionic surfactant (Span 20) and dissolved air flotation (DAF) was used to clarify this wastewater. Operating parameters including saturator pressure, recycle ratio, and air to oil ratio, were investigated to find conditions that would enhance the efficiency of the DAF

A. A Al-Shamrani; A James; H Xiao

2002-01-01

219

REMOVAL OF HUMICSUBSTANCES AND ALGAE BY DISSOLVED AIR FLOTATION  

EPA Science Inventory

Dissolved air flotation (DAF) is used in place of conventional gravity settling as a means to separate low density floc particles from water. The following objectives were: (1) to compare DAF to conventional water treatment of coagulation-flocculation followed by gravity settling...

220

Selective flotation of fossil resin from western coal  

SciTech Connect

The test program 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 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. The proof-of-concept testing has resulted in significant interest from several coal mining companies and has sparked the desire of local and state government to establish a fossil resin industry in the Wasatch Plateau coal field. In this view, the results from the current proof-of-concept testing program have been successful. This special report provides theoretical and analytical data on some surface chemistry work pertinent to fossil resin characterization, and other efforts carried out during the past months.

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

1992-03-20

221

Selective flotation of fossil resin from Western coal  

SciTech Connect

Technical activities for the fourth quarter involved efforts by both the University of Utah and Advanced Processing Technologies, Inc. Laboratory research at the University of Utah was primarily concerned with surface chemistry/resin characterization, which has emphasized Fourier transform infrared analysis in the past quarter. APT's major activities included proof-of-concept plant testing of the fossil resin flotation circuit. (VC)

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

1991-10-15

222

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

223

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

224

Round Robin Testing of Advanced Selective Agglomeration and Flotation Processes.  

National Technical Information Service (NTIS)

For the 28 mesh by 0 coal, the emerging selective agglomeration and flotation technologies (mainly C1, D1, F1, E1) show the following: (1) The various processes have similar efficiencies with regard to yield/ash relationships at high Btu recoveries. (2) M...

R. P. Killmeyer

1985-01-01

225

Boating Safety: The Use of Personal Flotation Devices.  

National Technical Information Service (NTIS)

Recent U.S. Coast Guard regulations have mandated the availability of Personal Flotation Devices (PFD's) on all recreational boats. In order to determine the level of use and factors associated with the use of PFD's, a mail survey of boat operators was co...

J. A. Bryk S. A. Schupack

1974-01-01

226

Environmental desulphurization of four Canadian mine tailings using froth flotation  

Microsoft Academic Search

Environmental desulphurization is an attractive alternative for management of acid generating tailings. This process placed at the end of the primary process treatment circuit will reduce a large amount of the problematic tailings by concentrating the sulphide fraction. To produce desulphurized tailings, non-selective froth flotation is the most adapted method. The desulphurization level is fixed by the sulphide content of

M Benzaazoua; B Bussière; M Kongolo; J McLaughlin; P Marion

2000-01-01

227

Modified column flotation of adsorbing iron hydroxide colloidal precipitates  

Microsoft Academic Search

A promising technique for the removal of heavy metal ions from wastewater streams involved firstly the ions adsorption on a colloidal precipitate (carrier) and then the separation of the loaded flocs (coagula) by a modified column flotation. Here, the effluent feed and the carrier (ferric hydroxide) enter smoothly by the top of the column through a special diffuser, in counter

F. Capponi; M. Sartori; M. L. Souza; J. Rubio

2006-01-01

228

Micro-agglomerate flotation for deep cleaning of coal  

SciTech Connect

We are investigating the use of a hybrid process, Micro-agglomerate flotation, which is a combination of oil-agglomeration and froth flotation. The basic concept is to use small quantities of oil to promote the formation of dense micro-agglomerates with minimal entrapment of water and mineral particles, and to use froth flotation to extract these micro-agglomerates from the water/dispersed-mineral phase. Since the floating units are agglomerates (about 30--50 [mu]m in size) rather than individual coal particles (1--10 [mu]m) the problems of froth overload and water/mineral carryover should be significantly alleviated.Micro-agglomerate flotation has considerable potential for the practical deep cleaning of coal on a commercial scale. In principle, it should be possible to achieve both high selectivity and high yield at reasonable cost. The process requires only conventional, off-the-shelf equipment and reagent usage (oil, surfactants, etc.) should be small. There are, however, complications. The process involves at least five phases: two or more solids (coal and mineral), two liquids (oil and water) and one gas (air). It is necessary to maintain precise control over the chemistry of the liquid phases in order to promote the interfacial reactions and interactions between phases necessary to ensure selectivity. Kinetics as well as thermodynamic factors may be critical in determining overall system response.

Chander, S.; Hogg, R.

1993-04-01

229

Winter operation of nation's first potable flotation plant. Technical report  

Microsoft Academic Search

The town of Lenox, Massachusetts, has an innovative 1.2-MGD (million gallon per day) potable water treatment plant, known as Sandfloat, on their reservoir system. The Sandfloat package plant is 22 ft in diameter and 6 ft in depth. It incorporates chemical flocculation, dissolved air flotation, and sand filtration into one unit, and has only 15 minutes of total detention time.

M. Krofta; L. K. Wang

1987-01-01

230

Ion flotation and solvent extraction of ferric thiocyanate complexes  

SciTech Connect

The influence of thiocyanate and accompanying mineral acids concentration on the effectiveness of Fe(III) ion flotation, Fe(III) precipitation in cetyltrimethylammonium ferric-thiocyanate form (as sublate), and Fe(III) extraction using ethyl acetate was studied. The effectiveness of these processes improves with the extent of Fe(III) complexation by thiocyanates. In the presence of acids, flotation and precipitation are increased as follows: HClO/sub 4/ < HCl < HNO/sub 3/ < H/sub 2/SO/sub 4/. The position of H/sub 3/PO/sub 4/ in this series changes with changing thiocyanate concentration. Extraction effectiveness is increased in the series: H/sub 3/PO/sub 4/ < H/sub 2/SO/sub 4/ < HNO/sub 3/, HClO/sub 4/, HCl. The following points are discussed: (a) the influence of acid anions competing with thiocyanate anions in Fe(III) complexation; (b) the influence of the competition between acid anions and complex ferric-thiocyanate anions in sublate formation; (c) the influence of hydrogen ion concentration increase in thiocyanate medium on the results of Fe(III) flotation, precipitation, and extraction; and (d) the influence of anion affinity for a collector on the solution surface properties and on Fe(III) flotation.

Jurkiewicz, K.

1987-12-01

231

Flotation behavior of digested asphalt ridge tar sands  

Microsoft Academic Search

The hot water process for Utah tar sands differs from that used for Canadian tar sands due to inherent differences in respective bitumen viscosities and the nature of bitumen-sand association. Although contact angle measurements of solvent extracted Asphalt Ridge bitumen indicated moderate hydrophobicity, air bubble attachment to the bitumen concentrate is not possible. This suggests that flotation separation is dependent

R. J. Smith; J. D. Miller

1981-01-01

232

Dynamic simulation of operating variables in flotation columns  

Microsoft Academic Search

Contributions to better control of flotation columns may come from improvements in different areas: measurements, dynamic and functional models, control strategies and control algorithms. Lack of process knowledge, specifically on transient behaviour and interaction among variables, generally leads to low quality conventional distributed control and partially inhibits further improvements.In this work, discrete multivariate dynamic models of operating variables were experimentally

L. G Bergh; J. B Yianatos

1995-01-01

233

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

234

Denitrification using a monopolar electrocoagulation\\/flotation (ECF) process  

Microsoft Academic Search

Nitrate levels are limited due to health concerns in potable water. Nitrate is a common contaminant in water supplies, and especially prevalent in surface water supplies and shallow wells. Nitrate is a stable and highly soluble ion with low potential for precipitation or adsorption. These properties make it difficult to remove using conventional water treatment methods. A laboratory batch electrocoagulation\\/flotation

Mohammad M. Emamjomeh; Muttucumaru Sivakumar

2009-01-01

235

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.

Knowlton, Nancy

2001-01-01

236

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...

237

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

238

Classifying Crushed Ore by Trommels  

Microsoft Academic Search

I REGRET to have misunderstood Mr. Rosales, whose report is certainly entitled to most respectful and careful consideration. My mistake (a natural one, I think) arose from a statement made on p. 13 of the report. Here Mr. Rosales says, in speaking of the Johnson's Reef Gold Mines Company, Eaglehawk, that ``the battery sand should previously be classified into different

T. K. Rose

1896-01-01

239

Retention of phytoplankton and planktonic microbes on coral reefs within the Great Barrier Reef, Australia  

NASA Astrophysics Data System (ADS)

Concentrations of phytoplankton (coccoid cychobacteria and total chlorophyll) and planktonic microrial communities (heterotropic bacteria, nanoflagellates and ciliates) were lower over leeward reef flats than over open water or reef faces, around Davies Reef and Myrmidon Reef in the central Great Barrier Reef, Australia. Concentrations of cyanobacteria, which accounted for approximately 15 50% of the carbon biomass of phytoplankton in open water, decreased from the reef face towards the leeward reef flat. Concentrations of ciliates were consistently lower at the leeward reef flat than at the reef face. For Davies Reef, the retention rates of phytoplankton and planktonic microbial communities were estimated to reach 253 gC d-1 per 1 m strip of the reef or about 0.09 gC m-2 d-1. This value is virtually equal to estimates of net community production (0.1 gC m-2 d-1). This allocthonous organic subsidy may help maintain spositive carbon balance on both Davies and Myrmidon Reefs on the Great Barrier Reef.

Ayukai, T.

1995-09-01

240

An Advanced Control System For Fine Coal Flotation  

SciTech Connect

A model-based flotation control scheme is being implemented to achieve optimal performance in the handling and treatment of fine coal. The control scheme monitors flotation performance through on-line analysis of ash content. Then, based on the economic and metallurgical performance of the circuit, variables such as collector dosage, frother dosage, and pulp level are adjusted using model-based control algorithms to compensate for feed variations and other process disturbances. Recent developments in sensor technology are being applied for on-line determination of slurry ash content. During the ninth quarter of this project, Task 3 (Model Building and Computer Simulation) and Task 4 (Sensor Testing) were nearly completed, and Task 6 (Equipment Procurement and Installation) was initiated. Previously, data collected from the plant sampling campaign (Task 2) were used to construct a population balance model to describe the steady-state and dynamic behavior of the flotation circuit. The details of this model were presented in the Eighth Quarterly Technical Progress Report. During the past quarter, a flotation circuit simulator was designed and used to evaluate control strategies. As a result of this work, a model-based control strategy has been conceived which will allow manipulated variables to be adjusted in response to disturbances to achieve a target incremental ash value in the last cell of the bank. This will, in effect, maximize yield at an acceptable product quality. During this same period, a video-based ash analyzer was installed on the flotation tailings stream at the Moss No. 3 preparation plant. A preliminary calibration curve was established, and data are continuing to be collected in order to improve the calibration of the analyzer.

G. H. Luttrell; G. T. Adel

1998-08-25

241

Coral Reef Ecosystems: Ecosystems in Crisis  

NSDL National Science Digital Library

This Science Object is the fourth of four Science Objects in the Coral Reef Ecosystems SciPack. It explores the natural and human causes of ecosystem stress. Human beings live near coral ecosystems and use them in a variety of ways. Increasing amounts of stress is brought on these ecosystems as humans continue to modify the surrounding environment as a result of population growth, technology, and consumption. Human destruction of habitats through direct harvesting, pollution, atmospheric changes, and other factors is threatening the stability and overall health of many coral reefs. Human activities may also exacerbate the impact of natural disturbances on coral reefs or compromise the ability of the reef to recover from events such as hurricanes, tsunamis, or disease. Learning Outcomes:� Describe ways in which human activities directly impact coral reef ecosystems (resource and recreational uses).� Describe ways in which human activities indirectly impact coral reef ecosystems (by changing the physical conditions, pollution, changes in the water chemistry, etc.).� Explain how human activity may decrease the reefs ability to recover from natural occurrences. � Explain the effects of increased predation or disease on a reef ecosystem.� Describe the effect of habitat loss on the reef ecosystem.� Describe the effects of weather and climate change on a healthy and weakened reef ecosystem.

National Science Teachers Association (NSTA)

2007-03-28

242

Biological models for Mesozoic reef evolution  

SciTech Connect

Throughout the Mesozoic, shallow-water carbonate ramps and platforms of the circumequatorial Tethyan Ocean were characterized by extensive development of reef ecosystems, especially during times of eustatic highstand, expansion of the Tropics, and warm equable global climates. The greatest reef development was north of the paleoequator in the Caribbean and Indo-Mediterranean provinces. These reefs and associated debris facies comprise major petroleum reservoirs, in some cases with remarkable porosity and permeability normally attributed to a combination of sedimentologic, tectonic, and diagenetic factors. The biological evolution of Mesozoic reefs also has had an important, and in some cases dominant, role in determining reservoir quality. Three major biological factors are critical to mesozoic reef-associated reservoir development: (1) the replacement/competitive displacement of coral-algal dominated, highly integrated reef ecosystems by loosely packed rudistid bivalve-dominated reef ecosystems in the Barremian-Albian; (2) the evolution of dominantly aragonitic, highly porous shells among framework-building rudistids in the middle and Late Cretaceous; and (3) competitive strategies among rudistids that effectively prevented widespread biological binding of Cretaceous reefs, leading to the production of large marginal fans that comprise major carbonate reservoirs. Detailed studies of these evolutionary trends in reef/framework development and of the distribution of different groups of bioconstructors on reefs lead to predictive modeling for primary and secondary porosity development in mesozoic carbonate reservoirs. The competitive displacement of coral-algal communities by rudistids on Cretaceous reefs was so effective that, even after Maastrichtian mass extinction of rudistids and other important groups comprising Mesozoic reef/carbonate platform ecosystems, coral-algal reef-building communities did not evolve again until the late Eocene.

Kauffman, E.G. (Univ. of Colorado, Boulder (USA))

1990-11-01

243

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

244

Advanced Physical Fine Coal Cleaning Microbubble Flotation. Topical Report No. 1. GHH-Bergbau Forschung Microbubble Coal Flotation Machine.  

National Technical Information Service (NTIS)

In conventional coal flotation, it is usual to use mechanically agitated cells. The agitator generates the air bubbles, mixes the slurry and air bubbles to bring about ''bubble-particle'' collisions. The average bubble size ranges between 500 and 1000 mic...

A. Gagnon M. V. Chari

1985-01-01

245

75 FR 48934 - Coral Reef Conservation Program Implementation Guidelines  

Federal Register 2010, 2011, 2012, 2013

...100726313-0313-01] RIN 0648-ZC19 Coral Reef Conservation Program Implementation...Final Implementation Guidelines for the Coral Reef Conservation Program...Implementation Guidelines (Guidelines) for the Coral Reef Conservation Program (CRCP or...

2010-08-12

246

78 FR 67128 - Coral Reef Conservation Program; Meeting  

Federal Register 2010, 2011, 2012, 2013

...National Oceanic and Atmospheric Administration Coral Reef Conservation Program; Meeting AGENCY: Coral Reef Conservation Program, Office of Ocean...hereby given of a public meeting of the U.S. Coral Reef Task Force (USCRTF). The meeting...

2013-11-08

247

How To Build a Freshwater Artificial Reef. (Second Edition).  

National Technical Information Service (NTIS)

Updated guidelines for planning and constructing artificial reefs in freshwater are given. Reef-building methods vary depending on habitat type (i.e. lakes, ponds, and reservoirs). Artificial reefs involve different problems in rivers than in non-flowing ...

E. D. Prince O. E. Maughan P. Brouha

1977-01-01

248

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

249

Dynamic fragility of oceanic coral reef ecosystems  

PubMed Central

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 the Seychelles results in local extinctions, substantial reductions in species richness, reduced taxonomic distinctness, and a loss of species within key functional groups of reef fish. The importance of deteriorating physical structure to these patterns demonstrates the longer-term impacts of bleaching on reefs and raises questions over the potential for recovery. We suggest that isolated reef systems may be more susceptible to climate change, despite escaping many of the stressors impacting continental reefs.

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

2006-01-01

250

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...

251

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

...Fish, Spiny Lobster, Queen Conch and Coral and Reef Associated Plants and Invertebrates...Resources, Spiny Lobster, Queen Conch, and Coral and Reef Associated Plants and Invertebrates...framework procedures for spiny lobster and coral and reef associated plants and...

2011-09-26

252

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

253

Microbial photosynthesis in coral reef sediments (Heron Reef, Australia)  

NASA Astrophysics Data System (ADS)

We investigated microphytobenthic photosynthesis at four stations in the coral reef sediments at Heron Reef, Australia. The microphytobenthos was dominated by diatoms, dinoflagellates and cyanobacteria, as indicated by biomarker pigment analysis. Conspicuous algae firmly attached to the sand grains (ca. 100 ?m in diameter, surrounded by a hard transparent wall) were rich in peridinin, a marker pigment for dinoflagellates, but also showed a high diversity based on cyanobacterial 16S rDNA gene sequence analysis. Specimens of these algae that were buried below the photic zone exhibited an unexpected stimulation of respiration by light, resulting in an increase of local oxygen concentrations upon darkening. Net photosynthesis of the sediments varied between 1.9 and 8.5 mmol O 2 m -2 h -1 and was strongly correlated with Chl a content, which lay between 31 and 84 mg m -2. An estimate based on our spatially limited dataset indicates that the microphytobenthic production for the entire reef is in the order of magnitude of the production estimated for corals. Photosynthesis stimulated calcification at all investigated sites (0.2-1.0 mmol Ca 2+ m -2 h -1). The sediments of at least three stations were net calcifying. Sedimentary N 2-fixation rates (measured by acetylene reduction assays at two sites) ranged between 0.9 to 3.9 mmol N 2 m -2 h -1 and were highest in the light, indicating the importance of heterocystous cyanobacteria. In coral fingers no N 2-fixation was measurable, which stresses the importance of the sediment compartment for reef nitrogen cycling.

Werner, Ursula; Blazejak, Anna; Bird, Paul; Eickert, Gabriele; Schoon, Raphaela; Abed, Raeid M. M.; Bissett, Andrew; de Beer, Dirk

2008-03-01

254

Decadal changes in community structure in Great Barrier Reef coral reefs  

Microsoft Academic Search

CRC-supported research within the Australian Institute of Marine Science's 'Sustaining Coral Reef Biodiversity' project is investigating current status and long-term change in communities of corals and associated benthos on Great Barrier Reef (GBR) coral reefs. Potential pressures on these assemblages are deterioration in water quality, reduction in beneficial impacts of fish and invertebrate predators and grazers brought about by fishing,

E Turak; L McCook; K Fabricius; Townsville MC Qld

255

Mechanism of selective ion flotation. 1. Selective flotation of transition metal cations  

SciTech Connect

An experimental investigation is presented of the batch ion flotation of the transition metal cations Cr{sup 3+}, Fe{sup 3+}, Mn{sup 2+}, Co{sup 2+}, Zn{sup 2+}, Ag{sup +}, Cd{sup 2+}, and In{sup 3+} from acidic aqueous solutions with sodium dodecylsulfonate and sodium dodecylbenzenesulfonate as anionic surfactants. The selectivity sequences Mn{sup 2+} < Zn{sup 2+} < Co{sup 2+} < Fe{sup 3+} < Cr{sup 3+} and Ag{sup +} < Cd{sup 2+} < In{sup 3+} are established, both from data for single and multi-ion metal cations solutions, where sublate was not formed in the bulk solution. Good agreement between the selectivity sequences and the values of ionic potential of metal cations was found. An experimental investigation was also performed on the solubility of sublates. The sublates solubility values are discussed in terms of ionic potentials of metal cations as well as of the surfactant size.

Walkowiak, W. (Technical Univ. of Wroclaw (Poland))

1991-01-01

256

South Illinois drilling expands with reef strikes  

Microsoft Academic Search

A base map shows where reef strikes have been made in S. Illinois. These strikes have resulted in exploration activity surge featuring Marion County which opened the Salem East field in Feb. 1973, flowing from the 3,900-ft reef buildup; and (2) Washington County, where a well flowed 45 bopd from a 2,600-ft depth reef this past March. A third well

J. A. Kornfeld; M. M. Travis

1973-01-01

257

Interview with Grace Reef by Diane Dewhirst  

Microsoft Academic Search

Biographical NoteGrace Reef grew up in Portland, Maine, with her father, Norman Reef, an attorney, and her mother, Patricia Reef. In 1974, as a twelve-year-old, she was the first female Little League baseball player, having sued to integrate girls into the program. She first heard of Senator Mitchell when he ran for governor in 1974. She attended Colby College, graduating

Grace Reef

2009-01-01

258

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

259

United States Coral Reef Task Force  

NSDL National Science Digital Library

The U.S. Coral Reef Task Force was established to lead the U.S. response to the growing global environmental crisis facing our coral reefs. This site contains information on what coral reefs are, where they can be found, how to protect them, and what the threats are. Reports on Task Force accomplishments and documents about national action plans and other information on the Task Force and their meetings is also included.

260

Holocene development of the Belize Barrier Reef  

Microsoft Academic Search

Previously, knowledge of the Holocene development of the Belize Barrier Reef (BBR)—the largest reef system in the Atlantic Ocean—was limited to one location (Carrie Bow Cay). We present new data from 11 rotary drill cores taken at 9 locations and 36 radiometric ages that indicate that the BBR was established from >8.26 to 6.68 ky BP on Pleistocene reef limestones,

Eberhard Gischler; J. Harold Hudson

2004-01-01

261

Prereduced Iron Ore Pellets: Preparation, Properties, Utilization.  

National Technical Information Service (NTIS)

A process for simultaneously reducing and indurating iron ore pellets was developed by Bureau of Mines laboratory research and confirmed on a continuous pilot plant basis. Moist iron ore concentrate was balled, mixed with solid reductant, and heated at ab...

M. M. Fine N. B. Melcher

1970-01-01

262

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

263

Coral Reef Protection: A Watershed Approach  

NSDL National Science Digital Library

This colorful, straightforward site from the Environmental Protection Agency (EPA)'s Oceans and Coastal Protection division (described in the November 25, 1998 Scout Report for Science & Engineering) outlines coral reef basic ecology and protection. About Coral Reefs provides background ecological information on coral reefs; Initiatives and Activities highlights EPA's activities but includes other US initiatives and links to symposia preceedings, factsheets, and other resources; and Related Links provides additional information on coral reef protection from the international, non-governmental (as well as federal), and educational sectors. A selection of recent news items (on the front page) rounds out the site.

Water., United S.

1998-01-01

264

Flotation rate and residence time distribution in continuous coal froth flotation circuits and an evaluation of reagents and circuit variations for pyritic sulfur removal  

SciTech Connect

This thesis gives the results of research conducted on several aspects of coal froth flotation. The effect of operating variables on the residence time distribution in coal froth flotation cells is discussed, and a model of the residence time distribution is presented for use with flotation rate models in scaling up from laboratory to plant scale. Flotation rate models are also investigated in detail for continuous coal froth flotation circuits. Changes in operating variables were found to affect the mean residence time in cells, but they did not have much effect on the mixing behavior. The use of a time lag was found to be an important part of rate models for continuous froth flotation cells. An important aspect of the use of such rate and residence time equations is their application to the flotation of gangue constituents, which often enter the froth by water carry-over in addition to natural flotation or flotation as slime coatings. As such, water carry-over is also investigated in this thesis for the laboratory and the plant and for both ash-forming minerals and pyrite. Maintaining a constant froth factor, the percentage of froth above the weir, in both laboratory and plant tests is believed to be a critical factor in predicting plant results using a kinetic factor ratio documented in the literature. Removing the pyrite and ash-forming minerals from coal that may be recovered by the water carry-over or other mechanisms is an important goal in coal froth flotation. This thesis also contains the results of tests with pyrite depressants and circuit variations for removal of pyritic sulfur.

Arnold, B.J.

1989-01-01

265

Great Barrier Reef, Queensland, Australia  

NASA Technical Reports Server (NTRS)

Along the coast of Queensland, Australia (18.0S, 147.5E), timbered foothills of the Great Dividing Range separate the semi-arid interior of Queensland from the farmlands of the coastal plains. Prominent cleared areas in the forest indicate deforestation for farm and pasture lands. Offshore, islands and the Great Barrier Reef display sand banks along the southern sides of the structures indicating a dominant southerly wind and current direction.

1991-01-01

266

Recovery of Arsenic from Ores and Concentrates.  

National Technical Information Service (NTIS)

This invention relates to recovery of arsenic, in the form of As2O3, from arsenical ores and concentrates. Typical of such ores are arseno-pyrite, cobaltite, niccolite, enargite, and speiss. Concentrates of the ores are prepared by conventional means such...

C. M. Flynn T. G. Carnahan

1982-01-01

267

Effect of multivalent ions on the flotation of coal  

SciTech Connect

Flotation of coal generally exhibits a maximum around neutral pH. This maximum, despite the marked mineralogical heterogeneity, has been attributed to the isoelectric point of the coal in this pH region. The results obtained in this study demonstrate the important role of multivariant ions in determining the pH dependence of flotation. Ca, Fe, and A electrolytes are found to depress coal in the pH region of metal hydroxide precipitation. Adsorption tests as a function of pH show coal to adsorb the multivalent ions in a manner similar to oxides. The data obtained here are examined in terms of possible surface and bulk precipitation of metal hydroxide species on coal surfaces.

Celik, M.S.; Somasundaran, P.

1986-06-01

268

In-plant testing of microbubble column flotation  

SciTech Connect

Microbubble column flotation (MCF) was developed at the Virginia Center for Coal and Minerals Processing (VCCMP) for the selective recovery of fine particles. Bench-scale test work conducted at VCCMP, largely under the sponsorship of the U.S. Department of Energy (DOE), showed that the technology worked well for both coal and mineral applications. For the technology to be commercially successful, however, a full-scale demonstration of the MCF technology was deemed necessary. This report summarizes the results of work performed under the DOE project entitled In-plant Testing of Microbubble Column Flotation.'' The objectives of this research and development effort were to duplicate the bench-scale performance of the MCF process in a full-scale unit, to verify the scale-up procedure developed in an earlier project, and to demonstrate the applicability of the MCF technology to the coal industry.

Yoon, R.H.; Luttrell, G.H.; Adel, G.T.; Mankosa, M.J.

1991-07-31

269

In-plant testing of microbubble column flotation. Final report  

SciTech Connect

Microbubble column flotation (MCF) was developed at the Virginia Center for Coal and Minerals Processing (VCCMP) for the selective recovery of fine particles. Bench-scale test work conducted at VCCMP, largely under the sponsorship of the U.S. Department of Energy (DOE), showed that the technology worked well for both coal and mineral applications. For the technology to be commercially successful, however, a full-scale demonstration of the MCF technology was deemed necessary. This report summarizes the results of work performed under the DOE project entitled ``In-plant Testing of Microbubble Column Flotation.`` The objectives of this research and development effort were to duplicate the bench-scale performance of the MCF process in a full-scale unit, to verify the scale-up procedure developed in an earlier project, and to demonstrate the applicability of the MCF technology to the coal industry.

Yoon, R.H.; Luttrell, G.H.; Adel, G.T.; Mankosa, M.J.

1991-07-31

270

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 5mg/L of chitosan, separation efficiency of >93% microalgae cells was found at 20mg/L of saponin. Removal efficiency of >54.4% and >73.0% was found for polysaccharide and protein, respectively at 20mg/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

271

Flotation of Heterocoagulated Particulates in Ulexite/SDS/Electrolyte System.  

PubMed

Salt-type minerals can be usually floated with either anionic or cationic collectors. In a number of systems, flotation has been reported to remarkably increase above the concentrations where precipitation of the collector salt is initiated. Some studies attribute this phenomenon to heterocoagulation of oppositely charged colloidal precipitate and mineral particles. In this study, ulexite, a semisoluble boron mineral, in the presence of various multivalent ions, i.e. Ba2+, Mg2+, Ca2+, and Al3+, was found to exhibit excellent flotation even when particles, colloidal precipitates, and bubbles acquire a similar charge, which indicates that attractive structural forces exceed the forces of electrostatic repulsion. Copyright 1998 Academic Press. PMID:9705762

Celik; Yasar; El-Shall

1998-07-15

272

Method for beneficiating coal ore  

Microsoft Academic Search

A new heavy liquid parting medium comprising an emulsion of water and a substantially water immiscible heavy parting liquid for use in beneficiating ores by gravity separations such as sink -float processes. The specific gravity of the emulsion parting medium can be adjusted by proportioning the relative amounts of water and the substantially water immiscible heavy liquid. Asmined coal is

Irons

1983-01-01

273

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

274

Minerals Yearbook, 1989: Iron Ore.  

National Technical Information Service (NTIS)

The United States produced 59.03 million metric tons (Mmt) of usable iron ore during 1989. Although the tonnage was only slightly more than that of 1988, significant improvements were made in pellet quality. For the first time, fluxed pellets accounted fo...

P. H. Kuck C. M. Cvetic

1989-01-01

275

Separation characteristics of different size and density fractions in batch coal flotation  

Microsoft Academic Search

Batch flotation experiments were carried out using two coal samples to study the behaviour of each size and the density fractions\\u000a in coal flotation. Different size fractions obtained from sizing of concentrates and tailing were subjected to float and sink\\u000a analysis using organic liquids. The distribution curve technique was adopted to evaluate the performance of flotation. The\\u000a results show that

M Vanangamudi; C Vinod Kumar; T C Rao

1988-01-01

276

Novel Condensed Ring Carboxylic Hydroxamic Acid Studied in the Flotation Behavior of Diaspore and Aluminosilicates  

Microsoft Academic Search

Flotation reagents are the critical technique in the flotation separation process for desilication. Aimed at the highly selective reagent for direct flotation of diasporic bauxite, a novel compound, dibenzo-1-(7-carboxyl-4-hydroxyl bicycle [2.2.2] octan-7,8-diyl) carboxamic acid (DBCA) with two functional groups carboxyl and hydroxamate in the same molecule, was synthesized through Diels-Alder reaction followed by oximation reaction. Subsequently, the floatability of diaspore,

Yu-Ren Jiang; Li-Yi Zhou; Xiao-Hong Zhou; Bin-Nan Zhao

2010-01-01

277

Investigating dissolved air flotation performance with cyanobacterial cells and filaments  

Microsoft Academic Search

Dissolved air flotation (DAF) performance with two different naturally occurring cyanobacterial morphologies was investigated with respect to the biomass removal efficiency, the toxin release to water and the coagulant demand by different water background natural organic matter (NOM). Coagulation (C)\\/Flocculation (F)\\/DAF bench-scale experiments (2 min coagulation at 380 s?1 with polyaluminium chloride (0.5–4 mg\\/L Al2O3, the dose depending on the water NOM content);

Margarida Ribau Teixeira; Vânia Sousa; Maria João Rosa

2010-01-01

278

Dissolved air flotation (DAF) performance at low saturation pressures  

Microsoft Academic Search

Dissolved Air (Pressure) Flotation-DAF, is a well-established solid and\\/or liquid\\/liquid separation process that uses micro-bubbles as a carrier phase. Bubbles are formed by a reduction of pressure of a water stream previously saturated with air (gas) at pressures usually higher than 3 atm. In industrial practice, the supersaturated water is forced trough needle valves, and clouds of bubbles having 0.02-0.15

L. A. Féris; J. Rubio

1999-01-01

279

Ion flotation—its potential for hydrometallurgical operations  

Microsoft Academic Search

Ion flotation is a separation technology for recovering and removing metal ions from dilute aqueous solutions. In this process, an ionic collector is utilized to transport non-surface active colligend ions of the opposite charge from a bulk solution to the solution–vapor interface. If a sufficiently large solution–vapor interfacial area can be provided by sparging gas through the solution, the colligend

Fiona M. Doyle

2003-01-01

280

Fundamental properties of the polyoxypropylene alkyl ether flotation frothers  

Microsoft Academic Search

A series of polyoxypropylene alkyl ethers, which includes common flotation frothers such as DF-200, DF-250 and DF-1012, have been tested. The “frothing” properties of these compounds were investigated through measuring their effect on bubble size and dynamic foamability index.The tests revealed a definite relationship between the number of propoxy groups in the CH3(OC3O6)nOH molecule and the critical coalescence concentration (CCC)

J. S Laskowski; T Tlhone; P Williams; K Ding

2003-01-01

281

Counterflow Co-flocculation Flotation for Water Purification  

Microsoft Academic Search

A new method for potable water treatment was brought forward and studied in this research. The treatment process was named as counterflow co-flocculation flotation (CC-FF). Pilot experiment was conducted and the operational parameters were presented. The optimized operational conditions are as follows: the detention time is 6–11 min with hydraulic load of 9–16 m\\/(m h); the recycle ratio should be no less

Jinlong Guo; Yili Wang; Dapeng Li; Hongxiao Tang

2003-01-01

282

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

283

Coral reef evolution on rapidly subsiding margins  

NASA Astrophysics Data System (ADS)

A series of well-developed submerged coral reefs are preserved in the Huon Gulf (Papua New Guinea) and around Hawaii. Despite different tectonics settings, both regions have experienced rapid subsidence (2-6 m/ka) over the last 500 ka. Rapid subsidence, combined with eustatic sea-level changes, is responsible for repeated drowning and backstepping of coral reefs over this period. Because we can place quantitative constraints on these systems (i.e., reef drowning age, eustatic sea-level changes, subsidence rates, accretion rates, basement substrates, and paleobathymetry), these areas represent unique natural laboratories for exploring the roles of tectonics, reef accretion, and eustatic sea-level changes in controlling the evolution of individual reefs, as well as backstepping of the entire system. A review of new and existing bathymetric, radiometric, sedimentary facies and numerical modeling data indicate that these reefs have had long, complex growth histories and that they are highly sensitive, recording drowning not only during major deglaciations, but also during high-frequency, small-amplitude interstadial and deglacial meltwater pulse events. Analysis of five generalized sedimentary facies shows that reef drowning is characterized by a distinct biological and sedimentary sequence. Observational and numerical modeling data indicate that on precessional (20 ka) and sub-orbital timescales, the rate and amplitude of eustatic sea-level changes are critical in controlling initiation, growth, drowning or sub-aerial exposure, subsequent re-initiation, and final drowning. However, over longer timescales (> 100-500 ka) continued tectonic subsidence and basement substrate morphology influence broad scale reef morphology and backstepping geometries. Drilling of these reefs will yield greatly expanded stratigraphic sections compared with similar reefs on slowly subsiding, stable and uplifting margins, and thus they represent a unique archive of sea-level and climate changes, as well as a record of the response of coral reefs to these changes over the last six glacial cycles.

Webster, Jody M.; Braga, Juan Carlos; Clague, David A.; Gallup, Christina; Hein, James R.; Potts, Donald C.; Renema, Willem; Riding, Robert; Riker-Coleman, Kristin; Silver, Eli; Wallace, Laura M.

2009-03-01

284

Coral reef evolution on rapidly subsiding margins  

USGS Publications Warehouse

A series of well-developed submerged coral reefs are preserved in the Huon Gulf (Papua New Guinea) and around Hawaii. Despite different tectonics settings, both regions have experienced rapid subsidence (2-6??m/ka) over the last 500??ka. Rapid subsidence, combined with eustatic sea-level changes, is responsible for repeated drowning and backstepping of coral reefs over this period. Because we can place quantitative constraints on these systems (i.e., reef drowning age, eustatic sea-level changes, subsidence rates, accretion rates, basement substrates, and paleobathymetry), these areas represent unique natural laboratories for exploring the roles of tectonics, reef accretion, and eustatic sea-level changes in controlling the evolution of individual reefs, as well as backstepping of the entire system. A review of new and existing bathymetric, radiometric, sedimentary facies and numerical modeling data indicate that these reefs have had long, complex growth histories and that they are highly sensitive, recording drowning not only during major deglaciations, but also during high-frequency, small-amplitude interstadial and deglacial meltwater pulse events. Analysis of five generalized sedimentary facies shows that reef drowning is characterized by a distinct biological and sedimentary sequence. Observational and numerical modeling data indicate that on precessional (20??ka) and sub-orbital timescales, the rate and amplitude of eustatic sea-level changes are critical in controlling initiation, growth, drowning or sub-aerial exposure, subsequent re-initiation, and final drowning. However, over longer timescales (> 100-500??ka) continued tectonic subsidence and basement substrate morphology influence broad scale reef morphology and backstepping geometries. Drilling of these reefs will yield greatly expanded stratigraphic sections compared with similar reefs on slowly subsiding, stable and uplifting margins, and thus they represent a unique archive of sea-level and climate changes, as well as a record of the response of coral reefs to these changes over the last six glacial cycles. ?? 2008 Elsevier B.V. All rights reserved.

Webster, J. M.; Braga, J. C.; Clague, D. A.; Gallup, C.; Hein, J. R.; Potts, D. C.; Renema, W.; Riding, R.; Riker-Coleman, K.; Silver, E.; Wallace, L. M.

2009-01-01

285

Nanoparticle flotation collectors: mechanisms behind a new technology.  

PubMed

This is the first report describing a new technology where hydrophobic nanoparticles adsorb onto much larger, hydrophilic mineral particle surfaces to facilitate attachment to air bubbles in flotation. The adsorption of 46 nm cationic polystyrene nanoparticles onto 43 ?m diameter glass beads, a mineral model, facilitates virtually complete removal of the beads by flotation. As little as 5% coverage of the bead surfaces with nanoparticles promotes high flotation efficiencies. The maximum force required to pull a glass bead from an air bubble interface into the aqueous phase was measured by micromechanics. The pull-off force was 1.9 ?N for glass beads coated with nanoparticles, compared to 0.0086 ?N for clean beads. The pull-off forces were modeled using Scheludko's classical expression. We propose that the bubble/bead contact area may not be dry (completely dewetted). Instead, for hydrophobic nanoparticles sitting on a hydrophilic surface, it is possible that only the nanoparticles penetrate the air/water interface to form a three-phase contact line. We present a new model for pull-off forces for such a wet contact patch between the bead and the air bubble. Contact angle measurements of both nanoparticle coated glass and smooth films from dissolved nanoparticles were performed to support the modeling. PMID:21790133

Yang, Songtao; Pelton, Robert; Raegen, Adam; Montgomery, Miles; Dalnoki-Veress, Kari

2011-09-01

286

Physical chemistry mechanisms of CDR system in sulphide mineral flotation  

NASA Astrophysics Data System (ADS)

The flotation tests, zeta potential measurements, and Fourier transform infrared spectroscopy (FTIR) analysis on galena, sphalerite, and pyrite were studied in a collecting-depressing-reactivating (CDR) system. In this system, sulphide minerals were first collected and activated by the collector, and then depressed strongly by Ca(OH)2 in a strong alkaline solution. Finally, they were reactivated by H2SO4. The flotation tests of pure minerals showed that in the Ca(OH)2 depressing process sulphide minerals had similar flotation characteristics because they had already been influenced by the collector. Hence, the flotability differences between them were reduced. However, in the H2SO4 reactivating process considerable differences in the flotability between galena and sphalerite/pyrite were produced. That is to say, galena was relatively easy to be reactivated by H2SO4, but sphalerite and pyrite were not reactivated at pH > 11. The zeta potentials of sulfide minerals measured by the Zeta Plus presented irreversible characteristics on the change of pH values. The results of the FTIR spectra analysis indicated that the collectors already adsorbed on the mineral surface were removed partially by Ca(OH)2.

Pak, To-Hyon; Sun, Ti-Chang; Kou, Jue; Huang, Chol-Ryong

2012-03-01

287

Flotation and flocculation chemistry of coal and oxidized coals  

SciTech Connect

The objective of this research project is to understand the fundamentals involved in the flotation and flocculation of coal and oxidized coals and elucidate mechanisms by which surface interactions between coal and various reagents enhance coal beneficiation. An understanding of the nature of the heterogeneity of coal surfaces arising from the intrinsic distribution of chemical moieties is fundamental to the elucidation of mechanism of coal surface modification and its role in interfacial processes such as flotation, flocculation and agglomeration. A new approach for determining the distribution in surface properties of coal particles was developed in this study and various techniques capable of providing such information were identified. Distributions in surface energy, contact angle and wettability were obtained using novel techniques such as centrifugal immersion and film flotation. Changes in these distributions upon oxidation and surface modifications were monitored and discussed. An approach to the modelling of coal surface site distributions based on thermodynamic information obtained from gas adsorption and immersion calorimetry is proposed. Polyacrylamide and dodecane was used to alter the coal surface. Methanol adsorption was also studied. 62 figs.

Somasundaran, P.

1990-01-01

288

AN ADVANCED CONTROL SYSTEM FOR FINE COAL FLOTATION  

SciTech Connect

A model-based flotation control scheme is being implemented to achieve optimal performance in the handling and treatment of fine coal. The control scheme monitors flotation performance through on-line analysis of tailings ash content. Then, based on an on-line estimate of incremental ash, the pulp level is adjusted using a model-based control algorithm to compensate for feed variations and other process disturbances. Recent developments in sensor technology are being applied for on-line determination of slurry ash content. During the tenth quarter of this project, Task 6 (Equipment Procurement and Installation) was completed through the efforts of J.A. Herbst and Associates, Virginia Tech, Pittston Coal Company, and FGR Automation. As a result of this work, a model-based control system is now in place which can predict incremental ash based on tailings ash content and general plant data, and adjust pulp level accordingly to maintain a target incremental ash. Testing of this control system is expected to be carried out during the next quarter, and the results of this testing will be reported in the Eleventh Quarterly report. In addition, calibration of the video-based ash analyzer was continued and an extensive set of calibration data were obtained showing that the plant is running remarkably well under manual control. This may be a result of increased attention being paid to froth flotation as a result of this project.

NONE

1998-10-25

289

AN ADVANCED CONTROL SYSTEM FOR FINE COAL FLOTATION  

SciTech Connect

A model-based flotation control scheme is being implemented to achieve optimal performance in the handling and treatment of fine coal. The control scheme monitors flotation performance through on-line analysis of tailings ash content. Then, based on an on-line estimate of incremental ash, the pulp level is adjusted using a model-based control algorithm to compensate for feed variations and other process disturbances. Recent developments in sensor technology are being applied for on-line determination of slurry ash content. During the eleventh quarter of this project, Task 7 (Operation and Testing) was nearly completed through the efforts of J.A. Herbst and Associates, Virginia Tech, and Pittston Coal Company. As a result of this work, a model-based control system has now been installed which can predict incremental ash based on tailings ash content and general plant data, and adjust pulp level accordingly to maintain a target incremental ash. The system has gone through a shake-down period, training has been carried out for plant operators, and the bulk of the control logic testing has been completed with the results of these tests awaiting analysis under Task 8 (System Evaluation). The flotation model has been shown to predict incremental ash quite successfully, implying that this approach may provide the basis for a useful ''soft sensor'' for on-line incremental ash analysis.

G.H. Luttrell; G.T. Adel

1999-01-11

290

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.

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

2014-01-01

291

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

292

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

293

Holocene development of the Belize Barrier Reef  

NASA Astrophysics Data System (ADS)

Previously, knowledge of the Holocene development of the Belize Barrier Reef (BBR)—the largest reef system in the Atlantic Ocean—was limited to one location (Carrie Bow Cay). We present new data from 11 rotary drill cores taken at 9 locations and 36 radiometric ages that indicate that the BBR was established from >8.26 to 6.68 ky BP on Pleistocene reef limestones, presumably deposited during oxygen isotope stage 5. The nonsynchronous start of Holocene reef growth was a consequence of variation in elevation of antecedent topography, largely controlled by underlying NNE-trending structures. From north to south, Pleistocene elevation decreases along these structural trends, probably reflecting differential subsidence and variations in karst topography. Reef anatomy is characterized by three facies. In order of decreasing abundance, these facies are represented by corals (mainly Acropora palmata and members of the Montastraea annularis group), by unconsolidated sand and rubble, and by well-cemented coral grainstones-rudstones. Holocene reef accumulation rates average 3.25 m/ky. The degree of reef consolidation is negatively correlated with Holocene thicknesses, indicating that slowly growing reefs are better cemented than fast growing ones. We present a Holocene sea-level curve for Belize based on 36 dates from this study and 33 dates from our previous studies in the area.

Gischler, Eberhard; Hudson, J. Harold

2004-02-01

294

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

295

Sterol components of coral-reef molluscs  

Microsoft Academic Search

The sterol composition of 23 species of coral-reef molluscs from Tahiti was investigated in relation to habitat and taxonomy. The elucidation of sterol components was performed by both argentation column and gas-liquid chromatographic techniques. Coral-reef molluscs, especially gastropods, seem to be characterised by sterols rich in 24-methylcholesterol.

T. Ando; A. Kanazawa; S. Teshima; H. Miyawaki

1979-01-01

296

Northwestern Hawaiian Islands Coral Reef Ecosystem Reserve  

NSDL National Science Digital Library

This page describes the unique Northwestern Hawaiian Islands (NWHI) Ecosystem Reserve. Provides resources focused on NWHI coral reef ecosystems, and introductions to reef research, management and protection activities. Educational outreach includes: teacher workshops; student activities, and a Discovery Center in Hilo, Hawaii that features exhibits and activities for schools and the public.

2011-04-22

297

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

298

Oyster Reef as Habitat for Estuarine Macrofauna.  

National Technical Information Service (NTIS)

The project assessed an oyster reef as nursery habitat for juveniles of economically important penaeid shrimps, blue crab, stone crab and game fishes. It was the first investigation to compare densities of fauna on an oyster reef with those in salt marsh ...

R. Zimmerman T. Minello T. Baumer M. Castiglione

1989-01-01

299

Silurian pinnacle reefs of the Canadian Arctic  

SciTech Connect

Pinnacle reefs are commonly an attractive target for oil exploration because they are usually porous carbonate bodies entombed in impervious, deep-water shales that provide both the source and the seal for hydrocarbons. Silurian pinnacle reefs, the first described in the Canadian Arctic Archipelago, are exposed on Ellesmere and Devon Islands. Two main reef trends occur, one of early middle Llandovery to middle Ludlow age and a second of middle Ludlow to Late Silurian or Early Devonian age. Reefs of both phases contain lime mudstone cores: some are stromatactoid-rich and others consist predominantly of microbialite-rich lime mudstone or microbial boundstone. Facies sequences of both reef phases show evidence of upward-shallowing overall, but, in the older reefs, isochronous capping facies are dominated either by coral-mirian or by stromatoporoid boundstone and floatstone. This difference perhaps reflects variation in wave stress and apparent ability of a few corals,thickly encrusted by or associated with microbial boundstone and skeletal algae, to withstand greater wave energy than a stromatoporoid-coral-rich reef community. These reefs constitute one of the bright prospects of hydrocarbon exploration in rocks of the Franklinian succession. 43 refs., 9 figs.

De Freitas, T.A.; Dixon, O.A. (Univ. of Ottawa, Ontario (Canada)); Mayr, U. (Institute of Sedimentary and Petroleum Geology, Alberta (Canada))

1993-04-01

300

Reproductive ecology of Caribbean reef corals  

Microsoft Academic Search

The last decade has seen a resurgence of interest in the processes of sexual reproduction by scleractinian reef corals. Earlier investigations had focused fortuitously on brooding (planulating) species, which resulted in the general misconception that brooding was the main form of larval development of reef corals. More recent work on Indo-Pacific species has shown broadcast spawning and short annual reproductive

Alina M. Szmant

1986-01-01

301

Reefs and Learning: Education Evaluation Techniques  

ERIC Educational Resources Information Center

Marine education research designs are discussed, and student learning outcomes while monitoring a coral reef is evaluated. Changes in environmental knowledge and attitudes, ecological intention to act, and direct reef experience were investigated. Differences between student pre-test and the post-test responses were observed, and analysis is…

Stepath, Carl M.

2006-01-01

302

Northwestern Hawaiian Islands Coral Reef Ecosystem Reserve  

NSDL National Science Digital Library

Describes the unique Northwestern Hawaiian Islands (NWHI) Ecosystem Reserve. Provides resources focused on NWHI coral reef ecosystems, and introductions to reef research, management and protection activities. Educational outreach includes: teacher workshops; student activities, and a Discovery Center in Hilo, Hawaii that features exhibits and activities for schools and the public.

303

Disease of coral and coral reef fishes  

USGS Publications Warehouse

The Department of the Interior protects sensitive habitats amounting to about 3,600,000 acres of coral reefs and other submerged lands. These reefs are important ecosystems in 13 National Wildlife Refuges, 10 National Parks and in certain territorial waters such as the Wake Atoll.

Panek, Frank

2008-01-01

304

Stabilized Coal Ash Artificial Reef Studies  

Microsoft Academic Search

In 1989, an experimental stabilized coal ash reef was deployed in Poole Bay off the southern coast of the UK. Three different mixtures of pulverised fuel ash, gypsum, flue gas desulphurisation sludge and cement were used along with concrete controls. the aim was to study the environmental compatibility of the reef materials through heavy metal analyses of the blocks to

K. J. Collins; A. C. Jensen

1995-01-01

305

Numerical Modeling of Atoll Reef Harbors.  

National Technical Information Service (NTIS)

The effect of the shape of a harbor cut through a reef on mitigating waves from the deep ocean was studied using a shallow water, nonlinear, long wave code called SWAN. A significant amount of the wave energy is dissipated over the reef regardless of the ...

C. L. Mader M. Vitousek S. Lukas

1986-01-01

306

Separating dolomite from phosphate rock by reactive flotation: Fundamentals and application  

NASA Astrophysics Data System (ADS)

Florida is currently one of the largest phosphate producers in the world. Unfortunately, the phosphate industry in Florida is suffering from depletion of the phosphate-rich ore. Dolomite, however, is a major impurity in the ores. The presence of MgO, in dolomite, can cause several problems during production of phosphoric acid and final fertilizers. Efforts to solve the dolomite problem have been reported by several researchers throughout the world. Yet, only heavy media separation process has been applied commercially. However, the process was discontinued because of its low separation efficiency in terms of grade and recovery. In this study, we tested an innovative idea based on simple fact that dolomite, as a carbonate mineral, generates CO2 when exposed to a slightly acidic solution, capturing CO2 bubbles at dolomite particle surface can selectively float the dolomite and separate it from phosphate. Formation of such bubbles requires a surface-active agent(s) at solution/dolomite interface. Preliminary tests indicated that polyvinyl alcohol (PVA) could serve this function. This process is called the Reactive Flotation, RF. To develop this process and to scale it up for industrial use, we conducted fundamental and applied research studies. Among these studies were optimizing of RF process by investigating the factors affecting the process (including bench and pilot scale tests) using statistical experimental designs. It was found that the acid concentration, PVA concentration, and particle size are the main factors. The optimum conditions were determined and applied to usage in a gravity separation device, (i.e., a sluice). Using such a device, a concentrate contains 0.65% MgO with >94 MgO % removal can be achieved. In addition, fundamental studies revealed that the hydrogen bonding is the adsorption mechanism confirmed by adsorption isotherm of PVA on dolomite and phosphate, adhesion of PVA to dolomite surface (using contact angle and surface tension), Fourier Transform InfraRed (FTIR), and Zeta potential. Moreover, PVA film thickness and polymer film elasticity (using dynamic surface tension) revealed that the optimum conditions could keep the PVA film at its highest elasticity. On the other hand, modeling was developed and used to predict CO2 formation rate and subsequent particle density change.

El-Midany, Ayman A.

307

Coral Reef Information System: Discover NOAA's Data  

NSDL National Science Digital Library

Part of the National Oceanic and Atmospheric Administration's Coral Reef Information System (CoRIS), this Web site is "designed to be a single point of access to NOAA coral reef information and data products, especially those derived from NOAA's Coral Reef Initiative Program." With Discover NOAA's Data, users can access information by a text search of metadata records, or by a spatial search using an Arc IMS application. The two approaches share many of the same data sets. With the text search, users may search NOAA coral reef information by title, author, keyword, etc. The map program includes "over 19,000 aerial photos, 400 preview navigational charts, tide stations, paleoclimatological studies, photo mosaics, coral reef monitoring, bleaching reports, and more." The site provides numerous help features for both search methods.

2008-06-09

308

Coral Reef Information System: Discover NOAA's Data  

NSDL National Science Digital Library

Part of the National Oceanic and Atmospheric Administration's Coral Reef Information System (CoRIS), this Web site is "designed to be a single point of access to NOAA coral reef information and data products, especially those derived from NOAA's Coral Reef Initiative Program." With Discover NOAA's Data, users can access information by a text search of metadata records, or by a spatial search using an Arc IMS application. The two approaches share many of the same data sets. With the text search, users may search NOAA coral reef information by title, author, keyword, etc. The map program includes "over 19,000 aerial photos, 400 preview navigational charts, tide stations, paleoclimatological studies, photo mosaics, coral reef monitoring, bleaching reports, and more." The site provides numerous help features for both search methods.

309

National Center for Caribbean Coral Reef Research  

NSDL National Science Digital Library

A number of research centers are concerned with the state of the world's coral reefs, and the National Center for Caribbean Coral Reef Research (NCORE) is one such center of scholarly excellence. Located at the University of Miami, NCORE is primarily concerned with "the analysis and predication of coral reef resilience". On their site, visitors can learn about some of their primary research initiatives, such as their work on the Florida reef tract and on tracking the effects of climate change on the reef communities. The general public will also find their digital map series quite useful as well. In this section, users can examine a number of complex digital maps and images that provide information about the state of coral cover around Puerto Rico, South Florida, and the Bahamas.

2006-01-06

310

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

311

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

312

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

313

Impact of a Changing Climate on Coral Reefs  

NSDL National Science Digital Library

This activity is about climate change impacts on coral reefs, specifically coral bleaching. Using ReefBase - an online GIS for coral reefs - learners will access data on selected coral reefs and manipulate the data to characterize these reefs. They will then be able to apply their understanding of reef composition to identify the location and conditions necessary to sustain the coral reef ecosystem and consider the factors that produce coral bleaching and the impact of climate change. A student handout and an answer sheet are available. This activity is part of Climate Change, Wildlife and Wildlands: A Toolkit for Formal and Informal Educators.

314

Modified release analysis procedure using advanced froth flotation mechanisms: Technical report, March 1, 1996-May 31, 1996.  

National Technical Information Service (NTIS)

Recent studies indicate that the optimum separation performances achieved by multiple stage cleaning using various column flotation technologies and single stage cleaning using a Packed-Flotation Column are superior to the performance achieved by the trad...

R. Q. Honaker

1997-01-01

315

The relative importance of local retention and inter-reef dispersal of neutrally buoyant material on coral reefs  

Microsoft Academic Search

Reef-scale, eddy-resolving numerical models are applied to discriminate between local trapping of neutrally buoyant passive material coming from a natal reef versus trapping of this material on reefs downstream. A hydrodynamic model is coupled with a Lagrangian (nongridded) dispersal simulation to map the movement of material such as passive larvae within and between natural reefs. To simplify the interpretation, a

Kerry P. Black

1993-01-01

316

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

317

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.

Goodwin, Mel

318

The Reef Environmental Education Foundation  

NSDL National Science Digital Library

The purpose of REEF is to educate and enlist divers in the conservation of marine habitats. The main focus of this site is the Fish Survey Project, in which volunteer scuba divers and snorkelers collect and report information on marine fish populations. The data is accessible through this website, and users can both contribute data they gather and generate reports from the database. A variety of reports can be created, including lists of all species found within a specific geographic area or the distribution of a fish species or family. There is an excellent explanation of how the data can be interpreted and what the parameters in the reports represent.

2003-02-17

319

Rigs-to-Reef Programs in the Gulf of Mexico  

Microsoft Academic Search

The Louisiana and Texas Artificial Reef Programs are the largest rigs-to-reef programs in the world. The program involves donating obsolete oil and gas structures for use as artificial reefs in lieu of on-shore removal. The National Fishing Enhancement Act of 1984 established the U.S. National Artificial Reef Plan and provided guidelines for state development of artificial reef programs. In 1986,

Mark J. Kaiser; Allan G. Pulsipher

2005-01-01

320

Effect of degree of substitution of carboxymethyl starch on diaspore depression in reverse flotation  

Microsoft Academic Search

Carboxymethyl starchs (CMS) with low and high degrees of substitution (CMSL and CMSH in short, respectively) were employed as depressants of diaspore in cationic reverse flotation using dodecylamine (DDA) as collector. The effect of degree of substitution of CMS on its depression performance was examined and the interaction mode and behavior were investigated in a comparative manner. Micro-flotation test showed

Hai-pu LI; Sha-sha ZHANG; Hao JIANG; Bin LI; Xing LI

2011-01-01

321

DISSOLVED AIR FLOTATION (DAF) FOR PRIMARY AND TERTIARY TREATMENT OF MUNICIPAL WASTEWATERS  

Microsoft Academic Search

Tertiary treatment of municipal wastewater by dissolved air flotation was studied on a pilot?scale. The effects of coagulant dose, flocculation pattern, dispersion water recycle ratio and hydraulic surface load on process performance were evaluated. The treatment of primary effluents by dissolved air flotation was investigated to assess the suitability of this process for the treatment of heavily polluted effluents and

J. Koivunen

2008-01-01

322

Flotation of molybdate oxyanions in dilute solutions. Part 1. Selective separation from arsenate  

Microsoft Academic Search

Ion flotation using a common cationic surfactant (dodecylamine) as collector was used for the quantitative recovery of molybdenum from dilute aqueous solutions. When arsenic co-existed with molybdenum in the solution, both arsenic and molybdenum were recovered. In this case, adsorbing colloid flotation, using ferric hydroxide as co-precipitant (or sorbent) and also dodecylamine as collector, has been examined for the selective

Zhao You-Cai; A. I. Zouboulis; K. A. Matis

1996-01-01

323

Air sparging during the solid\\/liquid separation by microfiltration: application of flotation  

Microsoft Academic Search

A large number of techniques have been used today to limit the membranes fouling and among them, certainly is air bubbling constituting also the transport medium in flotation, as applied in wastewater treatment; flotation is suitable as a pretreatment stage for microfiltration. Ceramic flat-sheet membrane modules were used in this paper, of multi-channel geometry and mainly their fouling tendency and

K. A. Matis; E. N. Peleka; D. Zamboulis; T. Erwe; V. Mavrov

2004-01-01

324

Evaluation of models for air recovery in a laboratory flotation column  

Microsoft Academic Search

One of the more interesting recent topics in flotation modelling is the association between the fraction of air that overflows to the concentrate as unbroken bubbles (air recovery, ?) and concentrate recovery. This paper analyses several models to estimate air recovery. These models were tested using experimental data obtained with a laboratory flotation column (2m high; 0.095m diam.), which was

R. H. Estrada-Ruiz; R. Pérez-Garibay

2009-01-01

325

Separation of Carbon Black from Silica by Froth Flotation Part 1: Effect of Operational Parameters  

Microsoft Academic Search

Froth flotation can be applied to separate hydrophobic particles from hydrophilic ones in aqueous solution with the use of an appropriate surfactant. In this work, carbon black was separated from silica gel by means of froth flotation. Since the point of zero charge, or PZC, of the carbon black (3.5) is close to that of the silica gel (4.1), a

Pisan Chungchamroenkit; Sumaeth Chavadej; John F. Scamehorn; Ummarawadee Yanatatsaneejit; Boonyarach Kitiyanan

2009-01-01

326

Removal of unburned carbon from municipal solid waste fly ash by column flotation  

Microsoft Academic Search

Unburned carbon (UC) is the major source of organic contaminants in municipal solid waste (MSW) fly ash. So most organic contaminants can be removed by the removal of the UC from the MSW fly ash. In this paper, we first used a technique of column flotation to remove UC from MSW fly ash. The influences of column flotation parameters on

Ying Huang; Masaki Takaoka; Nobuo Takeda

2003-01-01

327

Miocene reef carbonates of Mariana Islands  

SciTech Connect

Miocene carbonates in the southern Mariana Islands are impressive for their lithologic diversity, thicknesses (over 250 m), and geographic extent (> 20% combined outcrop coverage over four major high islands: Guam, Rota, Tinian and Saipan). Sections are dominated either by lagoonal algal-foraminiferal wackestones and mudstones with locally abundant high-energy shelly-skeletal facies, or by rubbly to muddy, fore-reef-to-bank deposits of packstones and grainstones with highly diverse and variable biogenic clasts. Fresh to deeply weathered volcaniclastic material may comprise at least 80% of some high-energy fore-reef facies, whereas lagoonal and bank deposits usually contain less than 0.5% terrigenous material. Surprisingly, the Miocene in the Marianas lacks almost completely any reef-core facies. Several poorly developed coral-rich mounds on Saipan and localized laminated red algal buildups on Guam appear to constitute the extant reef-wall facies in the Miocene. The lack of buildups may be a matter of differential survival; it may result from headland erosion and benching associated with emergence of narrow reef tracts as has been postulated by others for south Guam. Alternatively, the authors are proposing that Miocene bathymetry and the volume of terrigenous influx militated against significant reef core formation. Radiometric age dating of these reef carbonates has proven unsuccessful because pervasive diagenesis has transformed the entire Miocene section into low-magnesium calcite with minor and occasional dolomite. Freshwater phreatic diagenesis accounts for the principal porosity variation and trace element distribution.

Siegrist, H.G. Jr.

1988-02-01

328

Management of coral reefs: we have gone wrong when neglecting active reef restoration.  

PubMed

The current best management tools employed in coral reefs worldwide do not achieve conservation objectives as coral reefs continue to degrade. Even improved reef management helps, at best, to reduce the degradation pace, whereas the worsening global changes foretell a dismal fate for coral reefs. The assertion made here is that the prospect for reefs' future is centered on omnipresent acceptance of restoration, an 'active' management instrument. A recent promising such tool is the 'gardening concept', influenced by the well-established scientific discipline of terrestrial forestation. This notion is supported by a two-step protocol. The first step entails rearing coral "seedlings", in specially designed underwater nurseries, to transplantable size, before applying the second step, out-planting into damaged areas of the nursery-farmed coral colonies. Only the establishment of large-scale nurseries and transplantation actions, together with conventional management tools, will be able to cope with extensive reef degradation on the global scale. PMID:18829052

Rinkevich, Baruch

2008-11-01

329

Effective harvesting of low surface-hydrophobicity microalgae by froth flotation.  

PubMed

Microalgae harvesting by air flotation is a promising technology for large-scale production of biofuel, feed and nutraceuticals from algae. With an adherence-to-hydrocarbon method and two different types of flotation cells (mechanically agitated cell and Jameson cell), microalgal surface hydrophobicity and bubble size were identified to be critical for effective froth flotation of microalgae. Freshwater alga Chlorella sp. BR2 showed naturally a high hydrophobicity and an ideal response to flotation. However, many marine microalgae possess a low surface hydrophobicity and are thus difficult to harvest. This paper shows that a step-wise optimization approach can substantially improve the flotation of a low surface hydrophobicity marine microalga, Tetraselmis sp. M8, to near full recovery with an enrichment ratio of 11.4. PMID:24690467

Garg, Sourabh; Wang, Liguang; Schenk, Peer M

2014-05-01

330

Process for treating sulfide-bearing ores  

SciTech Connect

A process for removing sulfur from sulfide-bearing ores by reacting water vapor with the sulfide-bearing ore forming hydrogen sulfide while simultaneously regenerating water vapor by reacting the hydrogen sulfide with lime. Advantageously, the process occurs in the absence of a net consumption or production of gaseous species so that the process can be carried out in a closed system with respect to the gaseous species. Sulfidebearing ores which can be treated using the process of this invention include sulfide-bearing ores of molybdenum, zinc, iron, mercury, and copper. Advantageously, the molybdenum oxide so produced from the sulfide-bearing ore of molybdenum can be reacted further with lime and water producing calcium molybdate and hydrogen. The chalcopyrite form of the sulfide-bearing ore of copper produces bornite and magnetite.

Sohn, H.Y.

1983-03-15

331

Metal extraction from ores by heap leaching  

NASA Astrophysics Data System (ADS)

Heap leaching low-grade ores has become a major contributor to the extraction of economically important metals, notably copper and gold. The state-of-the-art in heap leaching is reviewed with emphasis on process engineering. Rock leaching, including rock pore diffusion and mineral kinetics, solution flow, and retention in ore heaps during percolation leaching, and bio-oxidation of sulfidic ores are covered. Oxygen transport into heaps by gaseous diffusion, natural convection, and forced air ventilation is discussed. Strategies for optimizing heap leaching include ore crushing, ore agglomeration, low-cost air ventilation of sulfide ore heaps undergoing bio-oxidation using fans, and the use of aggregate metal extraction rate constants in making metallurgical business decisions about heap leaching.

Bartlett, Robert W.

1997-08-01

332

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

333

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

NASA Astrophysics Data System (ADS)

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 (bar x{text{ }} ± {text{ 1 SE)}} of 1.3 (±0.6) x 109 cells g-1 DW of sediment. Bacterial production, measured as thymidine incorporation into DNA, ranged from 1.2 (±0.2) to 11.6 (±1.5) mg C m-2h-1 across the reef and was significantly lower in a reef crest basin than in the other zones. Bacterial growth rates (?) across the reef (0.05 to 0.33 g-1) correlated only with sediment organic carbon and nitrogen. Protozoan and meiofaunal densities varied by an order of magnitude across the reef and correlated with one or more sediment variables but not with bacterial numbers or growth rates. Nutrient flux rates were similar to those found at other reefs in the central and southern Great Barrier Reef and are significantly lower than rates measured in temperate sand communities. In the front lagoon, bioturbation and feeding acitivity by thalassinid shrimps ( Callianassa spp.) negatively influenced microbial and meiofaunal communities with a net import of organic matter necessary to support the estimated rates of bacterial productivity. In lagoonal areas not colonized by shrimps, primary productivity (400 1100 mg C m-2d-1) from algal mats was sufficient to support bacterial growth. It is suggested that deposit-feeding macrobenthos such as thalassinid crustaceans play a major role in the tructuring and functioning of lower trophic groups (bacteria, microalgae, protozoa, meiofauna) in coral reef sedments, particularly in laggons.

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

1987-10-01

334

Grazing pressure of herbivorous coral reef fishes on low coral-cover reefs  

Microsoft Academic Search

The impact of grazing by herbivorous fishes (Acanthuridae, Scaridae, and Pomacentridae) on low coral-cover reefs was assessed by measuring rates of benthic algal production and consumption on inshore and offshore reefs in the upper Florida Keys. Algal production rates, determined in situ with caged and uncaged experimental plates, were low (mean 1.05 g C m?2\\u000a  day?1) and similar among reef types. Algal consumption

Michelle J. Paddack; Robert K. Cowen; Su Sponaugle

2006-01-01

335

Spectral reflectance of coral reef bottom-types worldwide and implications for coral reef remote sensing  

Microsoft Academic Search

Coral reef benthic communities are mosaics of individual bottom-types that are distinguished by their taxonomic composition and functional roles in the ecosystem. Knowledge of community structure is essential to understanding many reef processes. To develop techniques for identification and mapping of reef bottom-types using remote sensing, we measured 13,100 in situ optical reflectance spectra (400–700 nm, 1-nm intervals) of 12

Eric J Hochberg; Marlin J Atkinson; Serge Andréfouët

2003-01-01

336

Contradicting Barrier Reef relationships for Darwin’s Evolution of reef types  

Microsoft Academic Search

The Darwinian progressive subsidence model for the evolution of fringing reefs, barrier reefs and atolls has been generally\\u000a accepted following the indisputable proof of subsidence provided by drilling results in the Pacific. Nonetheless, there are\\u000a data that do not fit the expectations of the model, such as the similar lagoon depths of barrier reefs and atolls as opposed\\u000a to the

Edward G. Purdy; Edward L. Winterer

2006-01-01

337

The seal reliability analysis of oring seals  

Microsoft Academic Search

First, the seal reliability function of the O-ring, that is the maximum contact stress between O-ring and plunger must be greater than the fluid pressure, is established, then on the basis of the nonlinear constitutive equation Mooney-Rivlin of rubber material, the finite element model of the O-ring is built using commercial software ABAQUS, according to the finite element model, the

Faguo Sun; Tianxiang Yu; Weimin Cui; Xiao Zong

2009-01-01

338

Tourmaline in the central Swedish ore district  

Microsoft Academic Search

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 Håksberg Fe oxide deposits, the Leja Cu deposit,

R. H. Hellingwerf; K. Gatedal; V. Gallagher; J. H. Baker

1994-01-01

339

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

340

Geomorphology of unique reefs on the western Canadian shelf: sponge reefs mapped by multibeam bathymetry  

NASA Astrophysics Data System (ADS)

Multibeam imagery of siliceous sponge reefs (Hexactinellida, Hexactinosida) reveals the setting, form, and organization of five reef complexes on the western Canadian continental shelf. The reefs are built by framework skeleton sponges which trap clay-rich sediments resulting in a distinctive pattern of low intensity backscatter from the reefs that colonize more reflective glacial sediments of higher backscatter intensity. Bathymetry and backscatter maps show the distribution and form of reefs in two large complexes in the Queen Charlotte Basin (QCB) covering hundreds of km2, and three smaller reef complexes in the Georgia Basin (GB). Ridges up to 7 km long and 21 m in height, together with diversely shaped, coalescing bioherms and biostromes form the principal reef shape in the QCB whereas chains of wave-form, streamlined mounds up to 14 m in height have developed in the GB. Reef initiation is dependent on the distribution of high backscatter-intensity relict glacial surfaces, and the variation in reef complex morphology is probably the result of tidally driven, near seabed currents.

Conway, Kim W.; Barrie, J. Vaughn; Krautter, Manfred

2005-09-01

341

76 FR 63904 - Proposed Information Collection; Comment Request; Coral Reef Conservation Program Administration  

Federal Register 2010, 2011, 2012, 2013

...Information Collection; Comment Request; Coral Reef Conservation Program Administration...SUPPLEMENTARY INFORMATION: I. Abstract The Coral Reef Conservation Act of 2000 (Act) was...enacted to provide a framework for conserving coral reefs. The Coral Reef Conservation...

2011-10-14

342

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

343

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

344

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

345

Quaternary coral reef refugia preserved fish diversity.  

PubMed

The most prominent pattern in global marine biogeography is the biodiversity peak in the Indo-Australian Archipelago. Yet the processes that underpin this pattern are still actively debated. By reconstructing global marine paleoenvironments over the past 3 million years on the basis of sediment cores, we assessed the extent to which Quaternary climate fluctuations can explain global variation in current reef fish richness. Comparing global historical coral reef habitat availability with the present-day distribution of 6316 reef fish species, we find that distance from stable coral reef habitats during historical periods of habitat loss explains 62% of the variation in fish richness, outweighing present-day environmental factors. Our results highlight the importance of habitat persistence during periods of climate change for preserving marine biodiversity. PMID:24876495

Pellissier, Loïc; Leprieur, Fabien; Parravicini, Valeriano; Cowman, Peter F; Kulbicki, Michel; Litsios, Glenn; Olsen, Steffen M; Wisz, Mary S; Bellwood, David R; Mouillot, David

2014-05-30

346

EPA Field Manual for Coral Reef Assessments  

EPA Science Inventory

The Water Quality Research Program (WQRP) supports development of coral reef biological criteria. Research is focused on developing methods and tools to support implementation of legally defensible biological standards for maintaining biological integrity, which is protected by ...

347

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...

348

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

349

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

350

A novel mineral flotation process using Thiobacillus ferrooxidans.  

PubMed

Oxidative leaching of metals by Thiobacillus ferrooxidans has proven useful in mineral processing. Here, we report on a new use for T. ferrooxidans, in which bacterial adhesion is used to remove pyrite from mixtures of sulfide minerals during flotation. Under control conditions, the floatabilities of five sulfide minerals tested (pyrite, chalcocite, molybdenite, millerite, and galena) ranged from 90 to 99%. Upon addition of T. ferrooxidans, the floatability of pyrite was significantly suppressed to less than 20%. In contrast, addition of the bacterium had little effect on the floatabilities of the other minerals, even when they were present in relatively large quantities: their floatabilities remained in the range of 81 to 98%. T. ferrooxidans thus appears to selectively suppress pyrite floatability. As a consequence, 77 to 95% of pyrite was removed from mineral mixtures while 72 to 100% of nonpyrite sulfide minerals was recovered. The suppression of pyrite floatability was caused by bacterial adhesion to pyrite surfaces. When normalized to the mineral surface area, the number of cells adhering to pyrite was significantly larger than the number adhering to other minerals. These results suggest that flotation with T. ferrooxidans may provide a novel approach to mineral processing in which the biological functions involved in cell adhesion play a key role in the separation of minerals. PMID:10427053

Nagaoka, T; Ohmura, N; Saiki, H

1999-08-01

351

Flotation method for extracting insects from poultry manure samples.  

PubMed

We examined the efficacy of a sucrose-based flotation method for extracting 3 prevalent insect species from poultry house manure: 3rd-instar Musca domestica L. (Diptera: Muscidae), Carcinops pumilio (Erichson) (Coleoptera: Histeridae) adults, and Alphitobius diaperinus (Panzer) (Coleoptera: Tenebrionidae) adults. A 0.6 M sucrose solution in distilled water altered the specific gravity to 1.2 and caused the 3 species to float to the water surface for easy separation. An analysis of variance (ANOVA) showed significant effects of the solution volume to sample mass ratio on recovery rates (F = 35.96, P < 0.0001), but no differences in species-specific recovery rates (F = 0.97, P = 0.3824). Among samples agitated in a ratio of at least 3.2 ml solution per gram of sample mass, we observed neither significant ratio effects (F = 1.37, P = 0.2442) nor significant differences in species-specific recovery rates (F = 2.05, P = 0.1353); overall, we recovered 97.49 +/- 0.20% of all individuals of the 3 species. Our analyses demonstrated that sucrose-based flotation was a statistically valid method of collecting these species from poultry manure samples. PMID:10071504

Tobin, P C; Pitts, C W

1999-01-01

352

Recovery of Mercury from Cinnabar Ores by Electrooxidation.  

National Technical Information Service (NTIS)

An electrolytic technique for oxidizing ore slurried with brine was investigated to determine its effectiveness in extracting mercury from ores. Optimization experiments conducted on a 2.5 pound mercury per ton ore resulted in 95 percent mercury extractio...

B. J. Scheiner D. E. Shanks R. E. Linstrom

1973-01-01

353

Explore coral reefs around the world  

NSDL National Science Digital Library

This Earth science resource uses a world map to show students the locations of five coral reefs. Students are instructed to toggle between maps coded according to ocean depth or water temperature to determine the conditions required for coral growth. Each reef is indicated by a red dot that students click on to view a photograph and to read additional information. Copyright 2005 Eisenhower National Clearinghouse

Education, Terc. C.; Littell, Mcdougal

2003-01-01

354

Remote Sensing of Coral Reef Processes  

Microsoft Academic Search

\\u000a Digital remote sensing of coral reefs dates to the first Landsat mission of the mid-1970s. Early studies utilized moderate-spatial-resolution\\u000a satellite broadband multispectral image data and focused on reef geomorphology. Technological advances have since led to development\\u000a of airborne narrow-band hyperspectral sensors, airborne hydrographic lidar systems, and commercial high-spatial-resolution\\u000a satellite broadband multispectral imagers. High quality remote sensing data have become widely

Eric J. Hochberg

355

Miocene reef carbonates of Mariana Islands  

SciTech Connect

Miocene carbonates in the southern Mariana Islands are impressive for their lithologic diversity, thicknesses (over 250 m), and geographic extend (>20% combined outcrop coverage over four major high islands: Guam, Rota, Tinian and Saipan). Sections are dominated either by lagoonal algal-foraminiferal wackestones and mudstones with locally abundant high-energy shelly-skeletal facies, or by rubbly to muddy, fore-reef-to-bank deposits of packstones and grainstones with highly diverse and variable biogenic clasts. Fresh to deeply weathered volcaniclastic material may comprise at least 80% of some high-energy fore-reef facies, whereas lagoonal and bank deposits usually contain less than 0.5% terrigenous material. Surprisingly, the Miocene in the Marianas lacks almost completely any reef-core facies. Several poorly developed coral-rich mounds on Saipan and localized laminated red algal buildups on Guam appear to constitute the extant reef-wall facies in the Miocene. The lack of buildups may be a matter of differential survival; it may result from headland erosion and benching associated with emergency of narrow reef tracts as has been postulated by others for south Guam. Radiometric age dating of these reef carbonates has proven unsuccessful because pervasive diagenesis has transformed the entire Miocene section into low-magnesium calcite with minor and occasional dolomite. Freshwater phreatic diagenesis accounts for the principal porosity variation and trace element distribution.

Siegrist, H.G. Jr.

1988-01-01

356

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

357

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

358

Application of dissolved air flotation on separation of waste plastics ABS and PS.  

PubMed

The aim of this research was to separate waste plastics acrylonitrile butadiene styrene (ABS) and polystyrene (PS) by dissolved air flotation in a self-designed dissolved air flotation apparatus. The effects of wetting agents, frother, conditioning time and flotation time on flotation behavior of waste plastics ABS (w-ABS) and PS (w-PS) were investigated and the optimized separation conditions were obtained. The results showed that when using 25 mgL(-1) tannic acid, 5 mgL(-1) terpineol, 15 min conditioning time and 15 min flotation time, mixtures of w-ABS and w-PS were separated successfully by dissolved air flotation in two stages, the results revealed that the purity and recovery rate of w-PS in the floated products were 90.12% and 97.45%, respectively, and the purity and recovery rate of w-ABS in the depressed products were 97.24% and 89.38%, respectively. Based on the studies of wetting mechanism of plastic flotation, it is found that the electrostatic force and hydrophobic attraction cannot be the main factor of the interaction between wetting agent molecules and plastic particles, which can be completed through water molecules as a mesophase, and a hydrogen bonding adsorption model with hydration shell as a mesophase was proposed. PMID:22503154

Wang, Hui; Chen, Xiao-Lei; Bai, Yang; Guo, Chao; Zhang, Li

2012-07-01

359

Leaching behaviour and mechanical properties of copper flotation waste in stabilized/solidified products.  

PubMed

This research describes the investigation of a cement-based solidification/stabilization process for the safe disposal of copper flotation waste and the effect on cement properties of the addition of copper flotation waste (CW) and clinoptilolite (C). In addition to the reference mixture, 17 different mixtures were prepared using different proportions of CW and C. Physical properties such as setting time, specific surface area and compressive strength were determined and compared to a reference mixture and Turkish standards (TS). Different mixtures with the copper flotation waste portion ranging from 2.5 to 12.5% by weight of the mixture were tested for copper leachability. The results show that as cement replacement materials especially clinoptilolite had clear effects on the mechanical properties. Substitution of 5% copper flotation waste for Portland cement gave a similar strength performance to the reference mixture. Higher copper flotation waste addition such as 12.5% replacement yielded lower strength values. As a result, copper flotation waste and clinoptilolite can be used as cementitious materials, and copper flotation waste also can be safely stabilized/solidified in a cement-based solidification/stabilization system. PMID:19220995

Mesci, Ba?ak; Coruh, Semra; Ergun, Osman Nuri

2009-02-01

360

Low grade ores – Smelt, leach or concentrate?  

Microsoft Academic Search

Metallic ore grades are falling globally as the higher grade reserves are exploited first and are progressively depleted. At the same time, the demand for primary metals extracted from these ores is expected to increase, despite increased levels of dematerialisation and recycling. Sustainability concerns have highlighted the need to meet these demands while at the same time minimising resource consumption

T. Norgate; S. Jahanshahi

2010-01-01

361

O-ring fiber optic pressure sensor  

NASA Astrophysics Data System (ADS)

Two optical fiber pressure sensor techniques are applied to the measurement of the distributed pressure of an O-ring. These sensors are polarimetrically and interferometrically based. Experimental results are presented for measuring the pressure exerted on an O-ring placed in a vacuum chamber and are compared with analytical results. Resolution and dynamic range of the fiber sensors are discussed.

Bouzid, Ahmed; Abushagur, Mustafa A.; He, Zhijian; Kosten, Susan E.

1994-04-01

362

Processing of Gold Bearing Antimony Ore  

Microsoft Academic Search

A wet chemical process was developed for the separation of gold from gold-bearing antimony sulphide ores. The ore sample was taken from the mine Urquidi from Oruro in Bolivia. It contained roughly 33% Sb in the form of antimonite. 24% Si in the form of quartz, small quantities of Pb, Fe, Cu, and Ni as well as 63 g\\/t gold,

E. GOCK; J. F. CORDOVA EQUIVAR

1995-01-01

363

Grazing pressure of herbivorous coral reef fishes on low coral-cover reefs  

NASA Astrophysics Data System (ADS)

The impact of grazing by herbivorous fishes (Acanthuridae, Scaridae, and Pomacentridae) on low coral-cover reefs was assessed by measuring rates of benthic algal production and consumption on inshore and offshore reefs in the upper Florida Keys. Algal production rates, determined in situ with caged and uncaged experimental plates, were low (mean 1.05gCm-2 day-1) and similar among reef types. Algal consumption rates were estimated using two different models, a detailed model incorporating fish bite rates and algal yield-per-bite for one species extrapolated to a guild-wide value, and a general regression relating fish biomass to algal consumption. Algal consumption differed among reef types: a majority of algal production was consumed on offshore reefs (55-100%), whereas consumption on inshore patch reefs was 31-51%. Spatial variation in algal consumption was driven by differences in herbivorous fish species composition, density, and size-structure among reef types. Algal consumption rates also varied temporally due to seasonal declines in bite rates and intermittent presence of large-bodied, vagile, schooling species. Spatial coherence of benthic community structure and temporal stability of algal turf over 3 years suggests that grazing intensity is currently sufficient to limit further spread of macroalgal cover on these low coral-cover reefs, but not to exclude it from the system.

Paddack, Michelle J.; Cowen, Robert K.; Sponaugle, Su

2006-08-01

364

Changes in the reef-coral community of Carysfort reef, Key Largo, Florida: 1974 to 1982  

Microsoft Academic Search

Data from 21 permanently marked line transects showed that significant changes occurred in the composition of the reef coral community on Carysfort Reef between 1975 and 1982–1983. Coral populations between 0 and 9 m show signs of change due primarily to physical disturbance while corals living between 10 and 21 m have decreased in abundance as a result of sedimentation

Phillip Dustan; John C. Halas

1987-01-01

365

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

366

Iron ore: from depletion to abundance.  

PubMed

Following World War II, Americans feared their iron ore supplies were depleted. The steel industry attempted to increase supplies by exploring foreign countries for new, high-grade hematite ores and experimenting with technology that upgraded low-grade domestic taconite ores into acceptable, but apparently uneconomical, pellets. Government did little at first, but the Korean War renewed fears of domestic resource exhaustion. Congress quickly enacted loan guarantees, rapid tax write-offs, and other tax policies that helped commercialize taconite pellets for national defense. These policies lingered long after the Korean War ended. Other policies bolstering taconite were enacted on the state level well after taconite had replaced hematite as industry's ore of choice. Understanding how government policies helped to develop pelletized lean iron ore may help in thinking about current policy suggestions aimed at easing our energy crisis or other mineral shortages. For taconite, too much government help came too late. PMID:17783804

Kakela, P J

1981-04-10

367

Study of Munella Ores. (puka Region, Albania)  

NASA Astrophysics Data System (ADS)

The study of Munella ores is based on four analysis (A, B, Cand cores). They represent different types of minerals in the Munella area. Cores were taken by the geologist of Puka Geological Enterprise. A Core: It represents an ore with pyrite and chalcopyrite where copper and sulfur contents are 0.77 and 8.2% respectively. B Core: This core represents an ore with spharelites and pyrite where zinc content is 1.5% and 2.9% sulfur one. C Core: It is a chalcopyrite ore, massive in nature, where copper content is 2.01% and 36% sulfur one. D Core: It also represents copper- zinc-sulfur ore where their content is 0.66, 1.00 and 4.28% respectively. Each core is studied individually by selective schema to have copper, zinc and pyrite concentrates. Copper and pyrite concentrates will be the first material for pyro- metallurgical industry.

Liçaj, Engjell; Mandili, Jorgo; Tabaku, Boran; Thomo, Niko

2010-01-01

368

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

369

Biologic response to environmental stress in tropical reefs: Lessons from modern Polynesian coralgal atolls and Middle Permian sponge and Shamovella microbe reefs (Capitan Limestone USA)  

Microsoft Academic Search

Despite prejudices that comparisons of paleoecological patterns in modern and fossil reef communities are of doubtful validity, we compare the biologic response of living coralgal reefs in French Polynesia to environmental stress with an exceptionally well exposed Middle Permian sponge reef and Shamovella-microbial reef of the Capitan Limestone in New Mexico. In the western Tuamotu Archipelago, reef margins are characterized

J. A. Fagerstrom; O. Weidlich

2005-01-01

370

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

371

Checklist of fishes from madagascar reef, campeche bank, méxico.  

PubMed

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. Hypoplectrusecosur was recorded here for the first time in the Gulf of Mexico, Mycteropercamicrolepis, Equetuslanceolatus and Chaetodipterusfaber were new records for the reefs of the Campeche Bank, Elacatinusxanthiprora was recorded for the second time in Mexico and expanded its known distribution westwards from Alacranes Reef and Sanopusreticulatus, endemic of the Yucatan state, was recorded here for the first time on a reef. PMID:24891834

Zarco Perello, Salvador; Moreno Mendoza, Rigoberto; Simões, Nuno

2014-01-01

372

Reef-sourced slope deposits, Holocene, Bahamas  

SciTech Connect

Observations and sampling to 350 m from a two-person submersible off Chub Cay, Berry Island, Bahamas, support the idea that the Holocene deep reef is a principal source of talus, now cemented, that foots the windward margins of Great Bahama Bank. At the Chub Cay dive site, a wall extends from 30 to 170 m subsea; below is a low-relief fore reef slope, ca. 50/sup 0/, of limestone veneered with sediment. The upper wall from 30 to 80 m, the deep reef, has a luxuriant growth of corals and a profusion of the calcareous alga halimeda spp. Below 50 m, living coral decreases, and from 80 to 170 m the wall is highly irregular with discontinuous ledges and blind-end caves. At depths from 150 to 170 m, the wall gives way to the fore reef slope whose relative smooth surface dips at 50/sup 0/ to 60/sup 0/ and extends to 350 m. The fore reef is limestone, but its topography resembles that of alluvial fans; rounded ridges rise a few meters above the intervening valleys that are tens of meters wide. The limestone surface has a discontinuous veneer of fine sediment and algal plates, and locally loose cobble and boulder-sized blocks of limestone. A sample of the limestone slope is of well-cemented coral clasts and skeletal sediment. They infer that the deep reef grows outward so rapidly that it caves periodically. The resulting debris bypasses the wall, but some is perched on the steep fore reef slope below where it is soon incorporated into the slope by submarine cementation.

Ginsburg, R.N.; Eberli, G.P.; Harris, P.M.; Slater, R.; Swart, P.K.

1987-05-01

373

Olivine flotation and crystallization of a global magma ocean  

NASA Astrophysics Data System (ADS)

According to the so-called olivine flotation hypothesis, basic silicate liquids become denser than coexisting ultramafic crystalline peridotites at high pressures through their higher compressibility. Therefore, the olivine, crystallizing from a global magma ocean, settles to a neutrally buoyant zone at about 250 km depth dividing the molten outer part of the Earth into two oceans separated by a dunite septum. The thermal evolution of such a divided global magma ocean is investigated using simple stability estimates and cooling time calculations. It appears that the cooling times and styles of convection (overturn, penetrative, layered) depend strongly on the surface temperature. Overturn convection leads to a compleate destruction of the dunite septum while in the case of penetrative convection the septum is only partly passed through. Thus, separate chemical evolution of the two mantle regions operates only at high surface temperatures near the solidus of mantle silicates of about 1500 K and cooling times of about 105 years.

Franck, Siegfried

1992-11-01

374

Winter operation of nation's first potable flotation plant. Technical report  

SciTech Connect

The town of Lenox, Massachusetts, has an innovative 1.2-MGD (million gallon per day) potable water treatment plant, known as Sandfloat, on their reservoir system. The Sandfloat package plant is 22 ft in diameter and 6 ft in depth. It incorporates chemical flocculation, dissolved air flotation, and sand filtration into one unit, and has only 15 minutes of total detention time. Lenox Plant has performed extremely well since July 1982. The Lenox reservoir system consists of two separate but adjacent impoundments (Upper Root Reservoir and Lower Root Reservoir) which are separated by a dam and open channel and about 15 ft elevational difference. Normally the water quality of these two reservoirs is very similar. However, the characteristics of Upper Root Reservoir water worsens in winter. The paper describes the seasonal turnover problems and the town's effort in solving the winter operational problems with an innovative chemical known as poly aluminum chloride (Ultrion).

Krofta, M.; Wang, L.K.

1987-09-20

375

Flotation purification of industrial wastewater by removing cyanide ions  

SciTech Connect

One of the oldest and most common methods of purifying sewage by removing cyanide ions is binding them to nontoxic compounds of ferrous salts, principally divalent ferrous salts. Research in this direction has also been realized for the sewage of coking plants. One of the reasons why the method has not been introduced is tied to the difficulty of separating the finely-dispersed slime of the divalent ferrous cyanide K/sub 4/(Fe(CN)/sub 6/). This study investigates methods of producing complex compounds of cyanide ions with ferrous salts which have low solubility and, as far as possible, are easily extracted from water. To achieve this, it is suggested that one of the promising methods of water purification - flotation - be used and that the sludge extracted be utilized in accordance with wellknown plans.

Evtyugina, N.M.; Derbysheva, E.K.; Kopktova, L.A.

1984-01-01

376

The National Oceanic and Atmospheric Administration's 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.

377

Optical spectra and pigmentation of Caribbean reef corals and macroalgae  

Microsoft Academic Search

Coastal reef degradation and widespread bleaching of corals, i.e. loss of pigments and\\/or symbiotic zooxanthellae, is increasing\\u000a globally. Remote sensing from boats, aircraft or satellites has great potential for assessing the extent of reef change, but\\u000a will require ground-verified spectral algorithims characteristic of healthy and degraded reef populations. We collected seven\\u000a species of Caribbean reef corals and also representative macroalgae

M. R. Myers; J. T. Hardy; C. H. Mazel; P. Dustan

1999-01-01

378

The Global Coral Reef Crisis: Trends and Solutions (Coral Reefs: Values, Threats, and the Marine Aquarium Trade)  

ScienceCinema

Second only to tropical rainforests, coral reefs support one of the world's most diverse natural habitats. Over 350 million individuals depend on coral reef resources for food and income. Unfortunately, the Earth is in the midst of a coral reef crisis. Anthropogenic impacts including overfishing, destructive fishing practices, sedimentation and pollution, as well as global climate change, have served to disrupt the natural processes that maintain the health of these ecosystems. Until recently, however, the global extent of the coral reef crisis was unknown. Reef Check was developed in 1996 as a volunteer, community-based monitoring protocol designed to measure the health of coral reefs on a global scale. With goals of education, monitoring, and management, Reef Check has activities in over 60 countries and territories. They have not only provided scientific evidence of the global extent of the coral reef crisis, but have provided the first community based steps to alleviate this urgent situation.

379

Boundary Reefs: Glass Sponge (Porifera Hexactinellidae) Reefs on the International Border Between Canada and the United States.  

National Technical Information Service (NTIS)

Hexactinellid sponge reefs have been discovered in shallow-water areas in Portland Canal on the international boundary between Southeast Alaska and British Columbia. The reefs were first observed on multibeam imagery data collected in 2008 and were examin...

D. J. Csepp J. V. Barrie K. W. Conway R. P. Stone

2014-01-01

380

46 CFR 25.25-15 - Retroreflective material for personal flotation devices.  

Code of Federal Regulations, 2013 CFR

...HOMELAND SECURITY UNINSPECTED VESSELS REQUIREMENTS Life Preservers and Other Lifesaving Equipment § 25...material for personal flotation devices. (a) Each life preserver, each marine buoyant device intended to be worn, and each...

2013-10-01

381

Foam Flotation Treatment of Heavy Metals and Fluoride-Bearing Industrial Wastewaters.  

National Technical Information Service (NTIS)

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...

D. J. Wilson

1977-01-01

382

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

Code of Federal Regulations, 2010 CFR

...animals, and fire. Any flotation within 40 feet of a line carrying fuel shall be 100 percent impervious to water and fuel. Styrofoam floatation must be fully encased. Reuse of plastic, metal, or other previously used drums or containers for...

2010-04-01

383

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

Code of Federal Regulations, 2010 CFR

...animals, and fire. Any flotation within 40 feet of a line carrying fuel shall be 100 percent impervious to water and fuel. Styrofoam floatation must be fully encased. Reuse of plastic, metal, or other previously used drums or containers for...

2009-04-01

384

Technical Performance Comparison of Coal-Pyrite Flotation and High-Gradient Magnetic Separation.  

National Technical Information Service (NTIS)

The Coal Preparation Division of the Pittsburgh Mining Technology Center conducted an investigation to assess and compare the pyritic sulfur reduction potential of coal-pyrite flotation and high-gradient magnetic separation (HGMS). Tests were run on three...

R. E. Hucko K. J. Miller

1980-01-01

385

Effect of Oxidation on the Flotation of Chromite and Associated Minerals.  

National Technical Information Service (NTIS)

The effects of oxidation on the floation of chromite and olivine were studied in an effort to improve chromite recovery from domestic sources. The flotation behavior of pure chromite, pure olivine, and a chromite gravity concentrate were investigated. Fre...

D. G. Kotlyar W. K. Tolley D. A. Rice

1995-01-01

386

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

...VALLEY AUTHORITY APPROVAL OF CONSTRUCTION IN THE TENNESSEE RIVER SYSTEM AND REGULATION OF STRUCTURES AND OTHER ALTERATIONS ...(d) Every flotation device employed in the Tennessee River system must be firmly and securely affixed to the...

2014-04-01

387

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

388

Combined Centrifugal Separation-Flotation-Magnetic Concentration Flowsheet for Treatment of Wolframite Slimes.  

National Technical Information Service (NTIS)

Based on testwork and plant practice a flowsheet has been developed combining centrifugal separation with flotation and magnetic concentration for the treatment of wolframite slimes to yield a high-grade tungsten concentrate. In May, 1977, laboratory and ...

P. Liu D. Wang

1987-01-01

389

Commercial tests of cationic flocculant in flotation treatment of waste water  

SciTech Connect

This work has been aimed at testing the efficiency of a polyacrylamide with cationic properties in the flotation separation of oil matter from waste water under industrial conditions. The N-dimethylaminated polyacrylamide that they synthesized manifests the properties of a high-molecular-weight cationic polyelectrolyte. This particular flocculant was selected because of its relatively high flocculating power, the sharp reduction that it gives in the volume of slime (foam) in reagent flotation treatment of waste water, and the lower content of mineral salts in the treated water. Commercial tests of the cationic flocculant were performed at the Gor'kii petroleum oil plant. The treating facilities in this plant include the following: reagent section, pumping station, flotation unit, and section for gravitational compaction of oil slime rejected from the flotation cell.

Sokolov, V.P.; Chikunova, L.A.; Kudrina, L.A.; Gustov, V.A.

1987-07-01

390

Removal of Extremely High Color from Water Containing Trihalomethane Precursor by Flotation and Filtration.  

National Technical Information Service (NTIS)

Trihalomethanes are primarily formed by the reaction of free chlorine with humic substances, such as humic acid and fulvic acid, called trihalomethane precursors. This paper introduces a new water purification system consisting of dissolved air flotation ...

L. K. Wang D. Barris P. Milne B. C. Wu J. Hollen

1982-01-01

391

Effect of Fine Grinding on the Production of Superclean Coal by Flotation.  

National Technical Information Service (NTIS)

Because of the growing need to develop new technology for producing superior quality coals to replace oil and natural gas, the US Department of Energy's Coal Preparation Division is looking at fine grinding and multistage flotation processes to maximize t...

K. J. Miller W. W. Wen

1985-01-01

392

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...

393

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

394

Coral reef assessment: An index utilizing sediment constituents  

Microsoft Academic Search

Resource managers need inexpensive bioindicators to evaluate the health of coral reef ecosystems and to inform decisions on when and where to utilize more expensive assessment techniques. Following USEPA Guidelines for Evaluating Ecological Indicators, I developed the SEDCON Index (SI), a rapid-assessment protocol whichutilizes reef sediment composition to assess the integrity of coral-reef communities. Keyadvantages of this index are that

Camille A. Daniels

2005-01-01

395

Reef development at the Frasnian\\/Famennian mass extinction boundary  

Microsoft Academic Search

A newly compiled global reef database indicates that the 5–6 Myr long Frasnian (Late Devonian) metazoan reef episode had relatively low diversity compared to Middle Devonian highs (with over 200 genera of calcitic rugose and tabulate corals). Following an initial early rise after Late Givetian coral and stromatoporoid extinctions, reefs expanded for the last time during mid-Frasnian sealevel highstands, but

Paul Copper

2002-01-01

396

Where in the world are Winslow Reef and Amelia Earhart?  

Microsoft Academic Search

Uncharted or doubtful positions of shoals and reefs have played a large role in the history of maritime navigation and oceanography. Two of these shoals, Winslow Reef and Reef and Sand Bank in the central equatorial Pacific, were the subjects of a fruitless 2-day aerial search in 1937 for Amelia Earhart by planes from the battleship USS Colorado.Sightings before and

R. S. Jacobson

1994-01-01

397

Coral reef recovery dynamics in a changing world  

Microsoft Academic Search

Coral reef ecosystems are degrading through multiple disturbances that are becoming more frequent and severe. The complexities of this degradation have been studied in detail, but little work has assessed characteristics that allow reefs to bounce back and recover between pulse disturbance events. We quantitatively review recovery rates of coral cover from pulse disturbance events among 48 different reef locations,

N. A. J. Graham; K. L. Nash; J. T. Kool

2011-01-01

398

Spectral unmixing of coral reef benthos under ideal conditions  

Microsoft Academic Search

Hyperspectral remote sensing has shown promise for detailed discrimination of coral reef substratum types, but, by necessity, it samples at pixel scales larger than reef substratum patch sizes. Spectral unmixing techniques have been successful in resolving subpixel areal cover in terrestrial environments. However, the application of spectral unmixing on coral reefs is fundamentally challenging, due not only to the water

J. D. Hedley; P. J. Mumby; K. E. Joyce; S. R. Phinn

2004-01-01

399

The Isla de Lobos and Associated Reefs, Veracruz, Mexico.  

National Technical Information Service (NTIS)

The reef which surrounds Isla de Lobos is one of three closely associated reefs on the eastern coast of Mexico, approximately 70 miles southeast of Tampico, Tamaulipas, and is the northernmost reef with a sand cay on the western margin of the Gulf of Mexi...

J. K. Rigby W. G. McIntire

1966-01-01

400

Measuring coral reef community metabolism using new benthic chamber technology  

Microsoft Academic Search

Accurate measurement of coral reef community metabolism is a necessity for process monitoring and in situ experimentation on coral reef health. Traditional methodologies used for these measurements are effective but limited by location and scale constraints. We present field trial results for a new benthic chamber system called the Submersible Habitat for Analyzing Reef Quality (SHARQ). This large, portable incubation

K. K. Yates; R. B. Halley

2003-01-01

401

Phase shifts in coral reef communities and their ecological significance  

Microsoft Academic Search

Many coral reefs around the world have degraded to a degree that their present intrinsic value and utility are greatly reduced: (mass coral mortality followed by algal invasions; local depletions of reef fisheries; deficit of reef accretion compared to physical and biological erosion). Though we can sometimes identify proximal causes (outbreaks of coral predators and eroders; over-fishing; habitat destruction), we

T. J. Done; Townsville MC

1992-01-01

402

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 ...

403

Coral Reef Education and Australian High School Students  

ERIC Educational Resources Information Center

Educational programs that focus on humans and their relationship to coral reefs are becoming necessary, as reef structures along the Queensland coast come under mounting ecological pressure. This paper reports on a PhD research project which investigated marine education and learning with high school students in coral reef environments along the…

Stepath, Carl M.

2004-01-01

404

Coral Reefs: A Gallery Program, Grades 7-12.  

ERIC Educational Resources Information Center

Gallery classes at the National Aquarium in Baltimore give the opportunity to study specific aquarium exhibits which demonstrate entire natural habitats. The coral reef gallery class features the gigantic western Atlantic coral reef (325,000 gallons) with over 1,000 fish. The exhibit simulates a typical Caribbean coral reef and nearby sandy…

National Aquarium in Baltimore, MD. Dept. of Education.

405

Apparatus for simultaneously disreefing a centrally reefed clustered parachute system  

Microsoft Academic Search

A single multi-line cutter is connected to each of a cluster of parachutes by a separate short tether line that holds the parachutes, initially reefed by closed loop reefing lines, close to one another. The closed loop reefing lines and tether lines, one from each parachute, are disposed within the cutter to be simultaneously cut by its actuation when a

Johnson

1988-01-01

406

Apparatus for simultaneously disreefing a centrally reefed clustered parachute system  

Microsoft Academic Search

A single multi-line cutter is connected to each of a cluster of parachutes by a separate short tether line that holds the parachutes, initially reefed by closed loop reefing lines, close to one another. The closed loop reefing lines and tether lines, one from each parachute, are disposed within the cutter to be simultaneously cut by its actuation when a

Johnson

1986-01-01

407

Biology and geology of eastern Pacific coral reefs  

Microsoft Academic Search

The tropical eastern Pacific region has historically been characterized as devoid of coral reefs. The physical conditions of the region are apparently not conducive to reef growth: low temperatures, low salinity, and high nutrient loads. But recent work has demonstrated persistent coral growth in some locations at relatively high accretion rates, dating at least 5600 y before present. Coral reefs

J. Cortés

1997-01-01

408

Effects of particle size and chain length on flotation of quaternary ammonium salts onto kaolinite  

NASA Astrophysics Data System (ADS)

Effects of particle size and chain length on flotation of quaternary ammonium salts (QAS) onto kaolinite have been investigated by flotation tests. Dodecyltrimethylammonium chloride (DTAC) and cetyltrimethylammonium chloride (CTAC) were used as collectors for kaolinite in different particle size fractions (0.075 ~ 0.01 mm, 0.045 ~ 0.075 mm, 0 ~ 0.045 mm). The anomalous flotation behavior of kaolinite have been further explained based on crystal structure considerations by adsorption tests and molecular dynamics (MD) simulation. The results show that the flotation recovery of kaolinite in all different particle size fractions decreases with an increase in pH. As the concentration of collectors increases, the flotation recovery increases. The longer the carbon chain of QAS is, the higher the recoveries of coarse kaolinite (0.075 ~ 0.01 mm and 0.045 ~ 0.075 mm) are. But the flotation recovery of the finest kaolinite (0 ~ 0.045 mm) decreases with chain lengths of QAS collectors increasing, which is consistent with the flotation results of unscreened kaolinite (0 ~ 0.075 mm). It is explained by the froth stability related to the residual concentration of QAS collector in mineral pulp. In lower residual concentration, the froth stability becomes worse. Within the range of flotation collector concentration, it's easy of CTAC to be completely adsorbed by kaolinite in the particle size fraction (0-0.045 mm), which led to lower flotation recovery. Moreover, it is interesting that the coarser particle size of kaolinite is, the higher flotation recovery is. The anomalous flotation behavior of kaolinite is rationalized based on crystal structure considerations. The results of MD simulations show that the (001) kaolinite surface has the strongest interaction with DTAC, compared with the (001) face, (010) and (110) edges. On the other hand, when particle size of kaolinite is altered, the number of basal planes and edge planes is changed. It is observed that the finer kaolinite particles size become, the greater relative surface area of edges and the more the number of edges are. It means that fine kaolinite particles have more edges to adsorb fewer cationic colletors than that of coarse kaolinite particles, which is responsible for the poorer floatability of fine kaolinite.

Longhua, Xu; Yuehua, Hu; Faqin, Dong; Hao, Jiang; Houqin, Wu; Zhen, Wang; Ruohua, Liu

2014-05-01

409

Detecting ecological change on coral reefs  

NASA Astrophysics Data System (ADS)

Remote sensing offers the potential to observe the response of coral reef ecosystems to environmental perturbations on a geographical scale not previously accessible. However, coral reef environments are optically, spatially, and temporally complex habitats which all present significant challenges for extracting meaningful information. Virtually every member of the reef community possesses some degree of photosynthetic capability. The community thus generates a matrix of fine scale features with bio-optical signatures that blend as the scale of observation increases. Furthermore, to have any validity, the remotely sensed signal must be "calibrated" to the bio-optics of the reef, a difficult and resource intensive process due to a convergence of photosynthetic light harvesting by green, red, and brown algal pigment systems. To make matters more complex, reefs are overlain by a seawater skin with its own set of hydrological optical challenges. Rather than concentrating on classification, my research has attempted to track change by following the variation in geo-referenced pixel brightness over time with a technique termed temporal texture. Environmental periodicities impart a phenology to the variation in brightness and departures from the norm are easily detected as statistical outliers. This opens the door to using current orbiting technology to efficiently examine large areas of sea for change. If hot spots are detected, higher resolution sensors and field studies can be focused as resources permit. While this technique does not identify the type of change, it is sensitive, simple to compute, easy to automate and grounded in ecological niche theory

Dustan, P.

2011-12-01

410

Surface alkaline phosphatase activities of macroalgae on coral reefs of the central Great Barrier Reef, Australia  

NASA Astrophysics Data System (ADS)

Inshore reefs of the Great Barrier Reef (GBR) are subject to episodic nutrient supply, mainly by flood events, whereas midshelf reefs have a more consistent low nutrient availability. Alkaline phosphatase activity (APA) enables macroalgae to increase their phosphorus (P) supply by using organic P. APA was high (~4.0 to 15.5 µmol PO4 3- g DW-1 h-1) in species colonising predominantly inshore reefs and low (<2 µmol PO4 3- g DW-1 h-1) in species with a cross-shelf distribution. However, APA values of GBR algae in this study were much lower than data reported from other coral reef systems. In experiments with two Sargassum species tissue P levels were correlated negatively, and N:P ratios were positively correlated with APA. High APA can compensate for a relative P-limitation of macroalgae in coral reef systems that are subject to significant N-inputs, such as the GBR inshore reefs. APA and other mechanisms to acquire a range of nutrient species allow inshore species to thrive in habitats with episodic nutrient supply. These species also are likely to benefit from an increased nutrient supply caused by human activity, which currently is a global problem.

Schaffelke, B.

2001-05-01

411

Effect of micro-bubbles on coagulation flotation process of dyeing wastewater  

Microsoft Academic Search

In order to enhance the pretreatment effect of dyeing wastewater, comparison experiments of coagulation micro-bubble floatation and coagulation conventional air bubble flotation were carried out. The results demonstrated that coagulation micro-bubble flotation significantly reduced coagulant doses and enhanced the pretreatment rate, because the usage of micro-bubble generator produces fog-like micro-bubbles with diameters in tens of micrometer, which has longer preservation

Shu Liu; Qunhui Wang; Hongzhi Ma; Peikun Huang; Jun Li; Takashige Kikuchi

2010-01-01

412

A new technique for characterizing aerated flocs in a flocculation–microbubble flotation system  

Microsoft Academic Search

A technique named Aerated Flocs Characterization (AFC) was developed and validated to characterize multiphase systems that are formed in flocculation–flotation (with microbubbles) systems at laboratory scale. Synthetic polyacrylamides were used to flocculate dispersed particles models of kaolin, activated carbon and iron hydroxide colloidal precipitate, Fe(OH)3. Aggregation and solid\\/liquid separations were conducted in a dissolved air flotation (DAF) apparatus, which consisted

C. Oliveira; R. T. Rodrigues; J. Rubio

2010-01-01

413

Research on Algae Removal by Electro-flotation\\/Photo-catalytic Oxidization Combined Process  

Microsoft Academic Search

The lake-type raw water was treated in Photo- catalytic Oxidization reactor. Under the condition of the inflow discharge control in 15L\\/h, the padding packing compares 2\\/5, UV lamp 30W, added no chemicals, pH 7.35, use the electro- flotation to treat it by two groups of plates to treat the water continuously. Then investigate the removal effect of pollutants after electro-flotation\\/Photo-catalytic

Wang Liping; Jiang Weijuan; Gao Naiyun

2011-01-01

414

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

415

Kinetics of reduction of iron ore—coal pellets  

Microsoft Academic Search

Kinetic data on the reduction of iron ore-coal pellets are compared with similar data for lump ore. It is shown that, when ore and coal are mixed intimately, the reduction reactions are accelerated considerably. Ore-coal pellets offer some additional advantages, as discussed in the text.

S. B. Sarkar; H. S. Ray; I. Chatterjee

1989-01-01

416

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

...Fish, Spiny Lobster, Queen Conch and Coral and Reef Associated Plants and Invertebrates...Islands, and Amendment 3 to the FMP for Corals and Reef Associated Plants and Invertebrates...procedures for the spiny lobster and Caribbean corals and reef associated plants and...

2011-11-07

417

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

...Fish, Spiny Lobster, Queen Conch and Coral and Reef Associated Plants and Invertebrates...Fish, Spiny Lobster, Queen Conch and Coral and Reef Associated Plants and Invertebrates...FMP), and Amendment 3 to the FMP for Corals and Reef Associated Plants and...

2011-12-30

418

Reef Water CO2 System and Carbon Production of Coral Reefs: Topographic Control of System-Level Performance  

Microsoft Academic Search

The variations of seawater CO2 system and organic and inorganic carbon production of coral reefs were investigated with respect to topographic types and oceanographic settings. Because of dominant carbonate production in coral reef ecosystems, most coral reefs are likely to act as a net or at least a potential CO2 source to the atmosphere. The comparison of the seawater CO2

Atsushi SUZUKI; Hodaka KAWAHATA

2004-01-01

419

Alkaline phosphatase activity of coral reef benthos  

NASA Astrophysics Data System (ADS)

Alkaline Phosphatase (AP-ase) activity was measured for a variety of benthic algae and a community of reef organisms. Algae with epiphytic bacteria showed a higher AP-ase activity than algae without bacteria (11.6 ?mol P g-1 h-1 vs. 1.9?mol P g-1h-1). AP-ase activity associated with the benthos was estimated to be in the range of 10 100 mmol P m-2d-1, at least 1000 Cold greater than reported activity in the water column. Enzyme activity of reef benthos at saturated organic phosphate (P) substrate concentrations was sufficiently high that P uptake from organic substrates could be as fast as inorganic P uptake. Organic P compounds may be important in P recycling, but there is no evidence that organic P represents a significant new source of P to coral reefs.

Atkinson, M. J.

1987-10-01

420

Ecology of artificial reefs in the subtropics.  

PubMed

The application of artificial reefs (ARs) has a long history, and there is a wealth of information related to the design and performance of ARs in coastal and ocean waters worldwide. However, relatively fewer studies in the literature are focused on the response of benthic communities within the reef areas than those on fish attraction and fish production and on the settlement and colonization of epibiota on the AR structures, especially in the subtropics where seasonal differences and environmental conditions can be large. Recent advances in the understanding of the ecology of ARs in the subtropics are highlighted, with a focus on fish attraction versus fish production, development of epibiota on AR systems and responses of in situ benthic communities in the reef areas. Data are also presented on studies of trophic relationships in subtropical AR systems, and further research areas using analyses of biological traits, stable isotope signatures and fatty acid profiles in investigating the ecology of ARs are proposed. PMID:24981732

Shin, Paul K S; Cheung, Siu Gin; Tsang, Tsui Yun; Wai, Ho Yin

2014-01-01

421

Distribution of ore deposits and spectrographic analyses of some rocks and ores on the Colorado Plateau  

USGS Publications Warehouse

The geographic pattern of known igneous rocks and ore deposits on the Colorado Plateau suggests a zonal arrangement of several types of ore deposits around centers of igneous activity. Spectrographic analyses of rocks and ores on the Plateau have been obtained in an effort to determine the distribution of elements and to examine the relationships between types of ore deposits and between the ore deposits and igneous rocks. Over 170 analyses of rocks and ores are given in this report. A preliminary study of these analyses suggests that the proportion of uranium, vanadium, copper, and silver in the uranium ores varies geographically, and that the pattern of variation may be in part concentric about some of the major laccolithic intrusions. It is also suggested that the following ratios of metals contained in the uranium ores are possible guides to larger-than-average ore deposits: (1) lead/uranium greater than 1, (2) lead/zinc greater than 10, and (3) zinc/geometric mean of cobalt and nickel less than 10.

Riley, Leonard Benjamin; Shoemaker, Eugene Merle

1952-01-01

422

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

423

Computations for Mine Ore/Mineral Rock.  

National Technical Information Service (NTIS)

Several calculations of the Mineral Rock event (which duplicated MINE ORE) were performed on Physics International's ELK code. Each of the calculations utilized a different, plausible model of in-situ rock. Peak displacements and velocity histories were c...

J. E. Reaugh

1972-01-01

424

Extraction of Molybdenum from Ores by Electrooxidation.  

National Technical Information Service (NTIS)

Extraction of molybdenum from molybdenite ore by an electrolytic oxidation procedure was investigated by the Bureau of Mines. Various parameters affecting molybdenum extraction, such as salt concentration, temperature, treatment rate, current density, and...

B. J. Scheiner R. E. Lindstrom

1972-01-01

425

Borehole Mining of Deep Phosphate Ore.  

National Technical Information Service (NTIS)

This citation summarizes a one-page announcement of technology available for utilization. The feasibility was tested of hydraulic borehole mining for the recovery of phosphate ore from the deep, water-saturated deposits of northeastern Florida. Hydraulic ...

1983-01-01

426

Process for Recovering Copper from Oxidized Ores.  

National Technical Information Service (NTIS)

The patent application relates generally to the hydrometallurgical recovery of metals from their source materials. More particularly, the present invention relates to the hydrometallurgical recovery of copper from its oxidized ores by using alkaline leach...

P. R. Haskett

1975-01-01

427

Recovery of Uranium from Refractory Ores.  

National Technical Information Service (NTIS)

Uranium is recovered from refractory carbonaceous-sulfidic ores or concentrates by leaching with nitric acid, followed by sorption on an ion exchange resin. In addition, the nitric acid leach solution is regenerated and recycled.

T. G. Carnahan K. P. V. Lei

1977-01-01

428

New Techniques in Processing Tungsten Ore Slimes.  

National Technical Information Service (NTIS)

New methods of beneficiation of wolframite ore slimes in China are described. A relatively high level of metal recovery has been maintained by the separate treatment of all plant slimes. Satisfactory results were gained with a centrifugal separator, a new...

S. Sun, Q. Chen, Y. Yang

1987-01-01

429

Recovery of Mercury from Ores and Concentrates.  

National Technical Information Service (NTIS)

Mercury is recovered from ores, concentrates, or wastes by means of a process comprising leaching with an aqueous solution of cupric chloride to form mercuric chloride and cuprous chloride. In addition, an additie such as calcium chloride is preferably us...

G. Atkinson

1981-01-01

430

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

431

Bill Would Allow Platforms as Artificial Reefs  

NASA Astrophysics Data System (ADS)

A 17 September U.S. congressional hearing on environmental aspects of oil and gas development focused primarily on potentially beneficial, alternative usages of thousands of decommissioned offshore oil and gas platforms in the Gulf of Mexico, and elsewhere. These platforms and associated rigs would be permitted to be used as artificial reefs for corals and fish populations, mariculture sites, and scientific research stations, under the Rigs to Reef Act, House Resolution 2654. The bill, introduced by Rep. David Vitter (R-Louisiana), currently is in referral in the Resources and in the Ways and Means committees of the House of Representatives.

Showstack, Randy

432

Fiji's largest marine reserve benefits reef sharks  

NASA Astrophysics Data System (ADS)

To provide more information about whether sharks benefit from no-take marine reserves, we quantified the relative abundance and biomass of reef sharks inside and outside of Namena, Fiji's largest reserve (60.6 km2). Using stereo baited remote underwater video systems (stereo-BRUVs), we found that the abundance and biomass of sharks was approximately two and four times greater in shallow and deep locations, respectively, within the Namena reserve compared to adjacent fished areas. The greater abundance and biomass of reef sharks inside Namena is likely a result of greater prey availability rather than protection from fishing. This study demonstrates that marine reserves can benefit sharks.

Goetze, J. S.; Fullwood, L. A. F.

2013-03-01

433

VISAR studies of a reefing line cutter  

SciTech Connect

The VISAR has been used to study the output performance of a pyrotechnic-driven reefing line cutter. Velocity-time and displacement-time profiles were obtained during blade motion, both with and without the reefing line present. The data yielded measures of the utilization of the blade's momentum and kinetic energy. Units of two different designs were tested. Those that leaked gas yielded considerably lower kinetic energy and momentum values. The VISAR data also showed evidence that gas leakage in such units occurs prior to, or during, the initial several millimeters of blade displacement.

Lieberman, M.L.; Wilson, R.S.

1980-01-01

434

Saltwater flotation for more efficient matrix separation of wetland macroinvertebrates does not affect total mercury or methylmercury concentrations.  

PubMed

The authors compared benthic wetland invertebrate matrix separation techniques (handpicking vs saltwater flotation) to test for effects on invertebrate mercury concentrations. Neither total mercury nor methylmercury concentrations differed significantly between techniques across 8 taxa. Matrix separation by the flotation technique took significantly less time and resulted in significantly greater abundance recovery in some taxa. The authors conclude that the saltwater-based flotation technique does not lead to mercury contamination or analytical interference issues. PMID:23440748

Dhal, Suman; Mitchell, Carl P J

2013-06-01

435

Unlocking refractory gold ores and concentrates  

NASA Astrophysics Data System (ADS)

The successful treatment of gold and silver ores is always a matter of economics, but it is not always a matter of grade, or metal content. Although the photograph accompanying this article depicts the notion that the scale of gold recovery is increasingly disproportionate to the amount of earth that must be processed, the economics of gold production nonetheless provide incentives attractive enough to justify greater investment in the development of effective treatments for refractory gold ores and concentrates.

McClincy, R. J.

1990-09-01

436

Reduction of double layered iron ore pellets  

Microsoft Academic Search

In the, present investigation an attempt has been made to study the reduction behaviour of double layer pellets consisting of a core of iron ore and a non-coking coal mixture within a shell of iron ore. The reduction tests were conducted under isothermal conditions in the temperature range 1000–1200°C. The variables (parameters) studied are reduction temperature, carbon\\/iron oxide ratio and

T. Sharma

1997-01-01

437

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

438

The continuing decline of coral reefs in Bahrain.  

PubMed

Historically coral reefs of Bahrain were among the most extensive in the southern basin of the Arabian Gulf. However, Bahrain's reefs have undergone significant decline in the last four decades as a result of large-scale coastal development and elevated sea surface temperature events. Here we quantitatively surveyed six sites including most major coral reef habitats around Bahrain and a reef located 72 km offshore. Fleshy and turf algae now dominate Bahrain's reefs (mean: 72% cover), and live coral cover is low (mean: 5.1%). Formerly dominant Acropora were not observed at any site. The offshore Bulthama reef had the highest coral cover (16.3%) and species richness (22 of the 23 species observed, 13 of which were exclusive to this site). All reefs for which recent and historical data are available show continued degradation, and it is unlikely that they will recover under continuing coastal development and projected climate change impacts. PMID:22980773

Burt, John A; Al-Khalifa, Khalifa; Khalaf, Ebtesam; Alshuwaikh, Bassem; Abdulwahab, Ahmed

2013-07-30

439

Upper Miocene reef complex of Mallorca, Balearic Islands, Spain  

SciTech Connect

The late Tortonian-Messinian coral reef platform of south Mallorca onlaps a folded middle late Miocene carbonate platform on which progradation of up to 20 km occurs. Vertical sea cliffs (up to 100 m high) superbly show the last 5 km of this progradation and complement the numerous water-well cores from the island interior. The Mallorca reef presents the most complete facies zonation of the Miocene reefs of the western Mediterranean. The reef wall framework is up to 20 m thick and shows (1) erosional reef flat with reef breccia and small corals; (2) spur-and-grove zone with large, massive corals; (3) deep buttresses and pinnacles with terraces of branching corals; and (4) deep reef wall with flat, laminar coral colonies, branching red algae, and Halimeda sands.

Pomar, L.

1988-02-01

440

Changes in the reef-coral community of Carysfort reef, Key Largo, Florida: 1974 to 1982  

NASA Astrophysics Data System (ADS)

Data from 21 permanently marked line transects showed that significant changes occurred in the composition of the reef coral community on Carysfort Reef between 1975 and 1982 1983. Coral populations between 0 and 9 m show signs of change due primarily to physical disturbance while corals living between 10 and 21 m have decreased in abundance as a result of sedimentation and disease. Some species show no signs of change while others appear to be undergoing shifts in their vertical distribution and/or significantly decreasing in mean colony size. Observed decreases in species diversity and eveness of the reef-building corals suggest that the vitality of Carysfort Reef declined between 1975 and 1982 1983.

Dustan, Phillip; Halas, John C.

1987-10-01

441

Coal Waste Artificial Reef Program: Reef measurements over four years in the sea: Final report  

SciTech Connect

To improve our understanding of the interaction of the Coal Waste Artificial Reef in the marine environment, a monitoring study to collect additional data on the reef's physical properties, mineral phases, chemical changes and biological communities was carried out. The first phase of the program constructed a demonstration fishing reef in the Atlantic Ocean off Long Island, NY in 1980, using 15,000 blocks formed from waste materials generated by two modern coal-fired power plants. This report discusses the data obtained from the fourth year of interactions between the coal waste reef blocks and marine environment. Data collected to estimate block lifetimes were: physical properties, strength and elastic modulus of blocks along with changes in mineral phases and in chemical properties, leaching of major elements from the blocks and dissolution data. In addition, biological studies assessed block suitability as substrates for colonization by marine life typical of the reef's inshore location. The coal waste reef blocks were retrieved from the demonstration C-WARP reef site after four years of continued exposure in sea water and examined. The physical properties, compressive strength, density and elastic modulus (which also relate to block structure and strength) were essentially maintained compared to the original characteristics. Furthermore, there was no evidence of deterioration in structural integrity of the submerged blocks. From the results of the four year research program, it can be concluded that the stabilized coal waste reef blocks are: acceptable materials for ocean disposal; suitable for colonization and growth of high density and diverse aquatic communities; and without adverse effect in the sea environment. 20 refs., 20 figs., 15 tabs.

Not Available

1987-05-01

442

Nutrient enrichment on coral reefs: Is it a major cause of coral reef decline?  

Microsoft Academic Search

Coral reefs are degrading worldwide at an alarming rate. Nutrient over-enrichment is considered a major cause of this decline\\u000a because degraded coral reefs generally exhibit a shift from high coral cover (low algal cover) to low coral cover with an\\u000a accompanying high cover and biomass of fleshy algae. Support for such claims is equivocal at best. Critical examination of\\u000a both

Alina M. Szmant

2002-01-01

443

Coral Reefs: An English Compilation of Activities for Middle School Students.  

ERIC Educational Resources Information Center

This activity book on coral reefs for middle school students is divided into 10 sections. Section 1 contains the introduction. Section 2 describes what coral reefs are while section 3 describes how coral reefs reproduce and grow. Section 4 discusses where coral reefs are found and section 5 describes life on a coral reef. Section 6 discusses the…

Walker, Sharon H.; Newton, R. Amanda; Ortiz, Alida

444

Encouraging Proximal Relations: Queensland High School Students Go to the Reef  

ERIC Educational Resources Information Center

Background: This article concerns learning with high school students and the effect of snorkeling and coral reef monitoring at the Great Barrier Reef, Australia. The effectiveness of classroom learning, student-reef relationships and reef trips were investigated. Purpose: This paper presents selected student accounts of reef educational…

Stepath, Carl; Whitehouse, Hilary

2006-01-01

445

Measurements of the local energy balance over a coral reef flat, Heron Island, southern Great Barrier Reef, Australia  

NASA Astrophysics Data System (ADS)

Coral reefs are thought to face significant threat from global warming due to increased water temperatures and ocean acidity. However, research into the surface energy balance of coral reefs and their associated micrometeorology is rare. Here we present, through a case study approach, the first direct in situ measurements of the surface energy balance of Heron Reef, a small platform coral reef in the southern Great Barrier Reef, Australia. Surface energy exchanges were measured using the eddy covariance method and show that during winter and spring an estimated 80-98% of net radiation goes into heating of the water overlaying the reef and reef substrate. As a result, cloud cover is considered the dominant control on heating of the reef flat environment. Change in cloud cover may therefore significantly affect the thermal environment of coral reefs and their ecology. Sensible and latent heat fluxes reached their highest values during wintertime advection of dry and cool continental air blowing from mainland Australia. This resulted in a net loss of energy from the reef flat and a decreasing trend in water temperature. Turbulent fluxes otherwise remained small, with sensible heat flux often close to zero. Results indicate that coral reefs may act as heat sinks during winter and as heat sources during spring, thereby affecting local water and atmosphere heat budgets and associated thermodynamics.

McGowan, Hamish A.; Sturman, Andrew P.; MacKellar, Melissa C.; Wiebe, Andrew H.; Neil, David T.

2010-10-01

446

Large-Scale Movement and Reef Fidelity of Grey Reef Sharks  

PubMed Central

Despite an Indo-Pacific wide distribution, the movement patterns of grey reef sharks (Carcharhinus amblyrhynchos) and fidelity to individual reef platforms has gone largely unstudied. Their wide distribution implies that some individuals have dispersed throughout tropical waters of the Indo-Pacific, but data on large-scale movements do not exist. We present data from nine C. amblyrhynchos monitored within the Great Barrier Reef and Coral Sea off the coast of Australia. Shark presence and movements were monitored via an array of acoustic receivers for a period of six months in 2008. During the course of this monitoring few individuals showed fidelity to an individual reef suggesting that current protective areas have limited utility for this species. One individual undertook a large-scale movement (134 km) between the Coral Sea and Great Barrier Reef, providing the first evidence of direct linkage of C. amblyrhynchos populations between these two regions. Results indicate limited reef fidelity and evidence of large-scale movements within northern Australian waters.

Heupel, Michelle R.; Simpfendorfer, Colin A.; Fitzpatrick, Richard

2010-01-01

447

Oil shales, evaporites and ore deposits  

NASA Astrophysics Data System (ADS)

The relationships between oil shales, evaporites and sedimentary ore deposits can be classified in terms of stratigraphic and geochemical coherence. Oil shale and black shale deposition commonly follows continental red beds and is in turn followed by evaporite deposition. This transgressive-regressive sequence represents an orderly succession of depositional environments in space and time and results in stratigraphic coherence. The amount of organic carbon of a sediment depends on productivity and preservation, both of which are enhanced by saline environments. Work on Great Salt Lake. Utah, allows us to estimate that only 5% of TOC originally deposited is preserved. Inorganic carbonate production is similar to TOC production, but preservation is much higher. Oil shales and black shales commonly are enriched in heavy metals through scavenging by biogenic particles and complexation by organic matter. Ore deposits are formed from such rocks through secondary enrichment processes, establishing a geochemical coherence between oil shales and ore deposits. The Permian Kupferschiefer of N. Europe is used as an example to define a Kupferschiefer type (KST) deposit. Here oxygenated brines in contact with red beds become acidified through mineral precipitation and acquire metals by dissolving oxide coatings. Oxidation of the black shale leads to further acid production and metal acquisition and eventually to sulfide deposition along a reducing front. In order to form ore bodies, the stratigraphic coherence of the red bed-black shale-evaporite succession must be joined by the geochemical coherence of the ore body-evaporite-black shale association. The Cretaceous Cu-Zn deposits of Angola, the Zambian Copperbelt as well as the Creta, Oklahoma, deposits are other KST examples. In the Zambian Copperbelt, evaporites are indicated by the carbonate lenticles thought to be pseudomorphs after gypsum-anhydrite nodules. MVT deposits are also deposited by acid brines, but at more elevated temperatures and with carbonates as principal host rocks. The Pine Point deposits are cited for their close association with evaporites. Alkaline, metal-rich brines are postulated for the HYC deposit of McArthur River, Australia. Such brines are known from the Green River Formation and deposits formed from such brines constitute the GRT class. They can be recognized by the presence of Magadi-type cherts and zeolite-analcime-K-spar tuffs. The Cu-Co ore bodies of Outokumpu, Finland, might also belong to this type. A new classification of sedimentary ore deposits is proposed, based on their geochemical environment. KST and MVT are formed from acid ore fluids, while GRT and CT (Creede type) are derived from basic ore fluids. pH of the fluids is best evaluated not from the ores themselves, but from their effect on the host-rocks.

Eugster, Hans P.

1985-03-01

448

Oxygen Metabolism of Some Reef Substrate Microcosms.  

National Technical Information Service (NTIS)

Measurements of oxygen demand by individual reef microcosms (deadheads) contained under plastic hemispheres were made at Hydro-Lab in February 1974. After baseline O2 consumption data were acquired, attempts were made to alter O2 demand rates of microcosm...

L. H. DiSalvo H. C. Ross

1974-01-01

449

Water Quality Standards for Coral Reef Protection  

EPA Science Inventory

The U.S. Clean Water Act provides a legal framework to protect coastal biological resources such as coral reefs, mangrove forests, and seagrass meadows from the damaging effects of human activities. Even though many resources are protected under this authority, water quality stan...

450

History of coral reefs and sea level  

SciTech Connect

Charles Darwin proposed crustal subsidence for atoll growth, on the Beagle, between England and Brazil, before even seeing a coral reef, on the basis of charts and discussions with Captain Fitzroy. Relative change of sea level due to crustal movements was then well-accepted from evidence of raised strandlines in Scandinavia and Scotland and sunken forests in England. Darwin added global change of sea level (tectonoeustasy) caused by remote tectonic activity, as explained by Robert Chambers (1848, p. 319). The glacioeustasy concept was mooted soon afterwards, though the term itself came later. When Suess in 1888 proposed eustatic change, he had in mind Archimedian displacement of water by sediment or lava accumulation on the sea floor. Integrated ideas of reef development also came in the 20th century. The powerful arguments against Darwin were led by Murray with his solution hypothesis, which can not be judged as good observation but from a narrow viewpoint. The Royal Society reef borings at Funafuti were heroic but at the same time misread. Subsequently came isotopic geochemistry, absolute dating, the Milankovitch insolation theory, and plate tectonics. And much more field work. The result is an integrated reef growth theory.

Fairbridge, R.W.

1985-01-01

451

Applying MCSST to coral reef bleaching  

Microsoft Academic Search

In the 1980s and early 1990s, coral reef bleaching events of unprecedented frequency and global extent were observed. Elevated water temperature is suspected as the primary causal stress of mass bleaching events from this period. The relationship between sea surface temperatures (SSTs) and coral bleaching events was investigated using National Oceanic and Atmospheric Administration (NOAA) Multi-Channel Sea Surface Temperature (MCSST)

M. W. Gleeson; A. E. Strong

1995-01-01

452

Modelling Coral Reef Futures to Inform Management: Can Reducing Local-Scale Stressors Conserve Reefs under Climate Change?  

PubMed Central

Climate change has emerged as a principal threat to coral reefs, and is expected to exacerbate coral reef degradation caused by more localised stressors. Management of local stressors is widely advocated to bolster coral reef resilience, but the extent to which management of local stressors might affect future trajectories of reef state remains unclear. This is in part because of limited understanding of the cumulative impact of multiple stressors. Models are ideal tools to aid understanding of future reef state under alternative management and climatic scenarios, but to date few have been sufficiently developed to be useful as decision support tools for local management of coral reefs subject to multiple stressors. We used a simulation model of coral reefs to investigate the extent to which the management of local stressors (namely poor water quality and fishing) might influence future reef state under varying climatic scenarios relating to coral bleaching. We parameterised the model for Bolinao, the Philippines, and explored how simulation modelling can be used to provide decision support for local management. We found that management of water quality, and to a lesser extent fishing, can have a significant impact on future reef state, including coral recovery following bleaching-induced mortality. The stressors we examined interacted antagonistically to affect reef state, highlighting the importance of considering the combined impact of multiple stressors rather than considering them individually. Further, by providing explicit guidance for management of Bolinao's reef system, such as which course of management action will most likely to be effective over what time scales and at which sites, we demonstrated the utility of simulation models for supporting management. Aside from providing explicit guidance for management of Bolinao's reef system, our study offers insights which could inform reef management more broadly, as well as general understanding of reef systems.

Gurney, Georgina G.; Melbourne-Thomas, Jessica; Geronimo, Rollan C.; Alino, Perry M.; Johnson, Craig R.

2013-01-01

453

In-plant testing of microbubble column flotation  

SciTech Connect

A project to evaluate the performance of the Virginia Tech Microbubble Column Flotation (MCF) process in an operating coal preparation plant was initiated during this past quarter. The project is concerned with the collection of process operating data using a 30-inch diameter column, and using this data to scale-up to a prototype, full-scale plant column. The work is being carried out at the Marrowbone Preparation Plant owned by the Shell Mining Corporation. Work has primarily concentrated on finalizing the project work plan (Task 2.1 -- Project Planning), instrumenting the 30-inch diameter column (Task 2.2 -- Advanced Instrumentation) and conducting a preliminary parametric study to evaluate the performance of the column (Task 2.3 -- Detailed Testing). To date, the column has been consistently capable of producing a 9.5% ash product at a 61% combustible recovery from a -150 mesh classifying cyclone overflow containing 55--60% ash at 3--5% solids. Tests conducted over an extended period of time indicate that the column consistently maintains grade in spite of fluctuations in the feed characteristics. 12 figs.

Yoon, R.H.; Luttrell, G.H.; Adel, G.T.

1989-01-01

454

Holocene coral reef rubble and its binding agents  

NASA Astrophysics Data System (ADS)

A literature review regarding reef rubble (defined as mechanically or chemically abraded parts of framebuilders or reef rock larger than sand fraction) and its binding agents is presented. Rubble is produced by natural and man-made events such as storms, wave agitation, earthquakes, bioerosion, ship groundings, and dynamite fisheries. The regeneration of reefs after rubble-forming processes requires rigid rubble binding, which is always preceded by preliminary stabilization. Preliminary stabilization can be achieved by a decline in hydrodynamic energy, interlocking of components, seagrass, and overgrowth by sponges or algae. Rigid binding is primarily achieved by diagenetic cementation. The literature indicates that binding by coralline algae or other organisms (corals, worms, bryozoans) is only of subordinate importance. Highest rates of rigid rubble binding are known from fore-reef areas with low sloping angles above fair-weather wave base; rigid rubble binding is particularly rare in deeper fore-reef environments and not described from the reef crest. Rigid binding by diagenetic cementation is generally known from inter- and supratidal near-shore ramparts as well as back-reef, reef-flat, and shallow fore-reef rubble accumulations, while coralline algae rigidly bind rubble only in very shallow fore-reef environments. Rubble binding does not appear to be easily achieved and fewer reports of bound rubble were found than of loose rubble.

Rasser, M.; Riegl, B.

2002-04-01

455

Fishing down the largest coral reef fish species.  

PubMed

Studies on remote, uninhabited, near-pristine reefs have revealed surprisingly large populations of large reef fish. Locations such as the northwestern Hawaiian Islands, northern Marianas Islands, Line Islands, U.S. remote Pacific Islands, Cocos-Keeling Atoll and Chagos archipelago have much higher reef fish biomass than islands and reefs near people. Much of the high biomass of most remote reef fish communities lies in the largest species, such as sharks, bumphead parrots, giant trevally, and humphead wrasse. Some, such as sharks and giant trevally, are apex predators, but others such as bumphead parrots and humphead wrasse, are not. At many locations, decreases in large reef fish species have been attributed to fishing. Fishing is well known to remove the largest fish first, and a quantitative measure of vulnerability to fishing indicates that large reef fish species are much more vulnerable to fishing than small fish. The removal of large reef fish by fishing parallels the extinction of terrestrial megafauna by early humans. However large reef fish have great value for various ecological roles and for reef tourism. PMID:24889317

Fenner, Douglas

2014-07-15

456

The Role of Turtles as Coral Reef Macroherbivores  

PubMed Central

Herbivory is widely accepted as a vital function on coral reefs. To date, the majority of studies examining herbivory in coral reef environments have focused on the roles of fishes and/or urchins, with relatively few studies considering the potential role of macroherbivores in reef processes. Here, we introduce evidence that highlights the potential role of marine turtles as herbivores on coral reefs. While conducting experimental habitat manipulations to assess the roles of herbivorous reef fishes we observed green turtles (Chelonia mydas) and hawksbill turtles (Eretmochelys imbricata) showing responses that were remarkably similar to those of herbivorous fishes. Reducing the sediment load of the epilithic algal matrix on a coral reef resulted in a forty-fold increase in grazing by green turtles. Hawksbill turtles were also observed to browse transplanted thalli of the macroalga Sargassum swartzii in a coral reef environment. These responses not only show strong parallels to herbivorous reef fishes, but also highlight that marine turtles actively, and intentionally, remove algae from coral reefs. When considering the size and potential historical abundance of marine turtles we suggest that these potentially valuable herbivores may have been lost from many coral reefs before their true importance was understood.

Goatley, Christopher H. R.; Hoey, Andrew S.; Bellwood, David R.

2012-01-01

457

Production of brown and black pigments by using flotation waste from copper slag.  

PubMed

One of the major problems in copper-producing countries is the treatment of the large amount of copper slag or copper flotation waste generated from copper slag which contains significant amounts of heavy metals such as Cu, Zn, Pb and Co. Dumping or disposal of such large quantities of flotation waste from copper slag causes environmental and space problems. In this study, the treatment of flotation waste from copper slag by a thermal method and its use as an iron source in the production of inorganic brown and black pigments that are used in the ceramic industry were investigated. The pigments were produced by calcining different amounts of flotation waste and chromite, Cr2O3, ZnO and CoO mixtures. The pigments obtained were added to transparent ceramic glazes and porcelainized tile bodies. Their colours were defined by L*a*b* measurements with a spectrophotometer. The results showed that flotation waste from copper slag could be used as an iron source to produce brown and black pigments in both ceramic body and glazes. PMID:16634227

Ozel, Emel; Turan, Servet; Coruh, Semra; Ergun, Osman Nuri

2006-04-01

458

Evaluation of flotation for purification of pyrite for use in thermal batteries  

NASA Astrophysics Data System (ADS)

The purification of pyrite (FeS2) used in Li-alloy/FeS2 thermal batteries by the physical process of flotation was evaluated for reduction of the quartz impurity. The process was compared to the standard process of leaching with concentrated hydrofluoric acid. Flotation was an attractive alternative because it avoided many of the safety and environmental concerns posed by the use of concentrated HF. The effects of particle size and initial purity of the pyrite feed material upon the final purity and yield of the product concentrate were examined for batch sizes from 3.5 to 921 kg. Feed materials as coarse as 8 mm and as fine as -325 mesh were treated; the coarse pyrite was ground wet in a rod mill or dry in a vibratory mill to -230 mesh prior to flotation. Both the HF-leached and the flotation-treated pyrite were leached with HCI (1:1 v/v) to remove acid-soluble impurities. The flotation-purified pyrite concentrates were formulated into catholytes; their electrochemical performance was evaluated in both single cells and 5-cell batteries for comparison to data generated under the same discharge conditions for catholytes formulated with HF/HCI purified pyrite.

Guidotti, R. A.; Reinhardt, F. W.

1992-07-01

459

Treatment of municipal wastewater UASB reactor effluent by unconventional flotation and UV disinfection.  

PubMed

Post-treatment of an UASB reactor effluent, fed with domestic sewage, was conducted using two-stage flotation and UV disinfection. Results were compared to those obtained in a parallel stabilisation pond. The first flotation stage employed 5 - 7.5 mg L(-1) cationic flocculant to separate off more than 99% of the suspended solids. Then, phosphate ions were completely recovered using carrier flotation with 5-25 mg L(-1) of Fe (FeCl3) at pH 6.3-7.0. This staged flotation led to high recoveries of water and allowed us to separate organic matter and phosphate bearing sludge. The water still contained about 1 x 10(2) NMP/100 mL total coliforms, which were removed using UV radiation to below detection levels. Final water turbidity was < 1.0 NTU, COD < 20 mg L(-1) O2 and 71 mNm(-1), the liquid/air interfacial tension. This flotation-UV flowsheet was found to be more efficient than the treatment in the stabilisation pond and appears to have some potential for water reuse. Results were discussed in terms of the biological, chemical and physicochemical mechanisms involved. PMID:16180444

Tessele, F; Monteggia, L O; Rubio, J

2005-01-01

460

76 FR 24050 - Coral Reef Restoration Plan, Final Programmatic Environmental Impact Statement, Biscayne National...  

Federal Register 2010, 2011, 2012, 2013

...Service [2310-0003-422] Coral Reef Restoration Plan, Final Programmatic Environmental...Impact Statement for the Coral Reef Restoration Plan, Biscayne National Park...Impact Statement for the Coral Reef Restoration Plan (Plan/FEIS) for Biscayne...

2011-04-29

461

75 FR 21650 - Coral Reef Restoration Plan, Draft Programmatic Environmental Impact Statement, Biscayne National...  

Federal Register 2010, 2011, 2012, 2013

...INTERIOR National Park Service Coral Reef Restoration Plan, Draft Programmatic Environmental...Impact Statement for the Coral Reef Restoration Plan, Biscayne National Park...Statement (DEIS) for the Coral Reef Restoration Plan for Biscayne National Park,...

2010-04-26

462

77 FR 12323 - Draft Environmental Impact Statement for the General Management Plan, Buck Island Reef National...  

Federal Register 2010, 2011, 2012, 2013

...Buck Island Reef National Monument, Virgin Islands AGENCY: National Park Service...Buck Island Reef National Monument, Virgin Islands...for Buck Island Reef National Monument, Virgin Islands. [[Page 12324

2012-02-29

463

Key Ecological Interactions of Reef Building Corals - 11-16-2011  

EPA Science Inventory

Coral reefs are very important marine ecosystems because they support tremendous biodiversity and reefs are critical economic resources many coastal nations. Tropical reef structures are largely built by stony corals. This presentation provides background on basic coral biology t...

464

76 FR 77779 - Availability of Seats for the Northwestern Hawaiian Islands Coral Reef Ecosystem Reserve Advisory...  

Federal Register 2010, 2011, 2012, 2013

...Seats for the Northwestern Hawaiian Islands Coral Reef Ecosystem Reserve Advisory Council...seats on the Northwestern Hawaiian Islands Coral Reef Ecosystem Reserve Advisory Council...SUPPLEMENTARY INFORMATION: The NWHI Coral Reef Ecosystem Reserve is a [[Page...

2011-12-14

465

77 FR 12567 - Proposed Information Collection; Comment Request; Pacific Islands Region Coral Reef Ecosystems...  

Federal Register 2010, 2011, 2012, 2013

...Comment Request; Pacific Islands Region Coral Reef Ecosystems Logbook and Reporting AGENCY...U.S. citizen issued with, a Special Coral Reef Ecosystem Fishing Permit (authorized under the Fishery Management Plan for Coral Reef Ecosystems of the Western...

2012-03-01

466

77 FR 16211 - Availability of Seats for the Northwestern Hawaiian Islands Coral Reef Ecosystem Reserve Advisory...  

Federal Register 2010, 2011, 2012, 2013

...Seats for the Northwestern Hawaiian Islands Coral Reef Ecosystem Reserve Advisory Council...seats on the Northwestern Hawaiian Islands Coral Reef Ecosystem Reserve Advisory Council...SUPPLEMENTARY INFORMATION: The NWHI Coral Reef Ecosystem Reserve is a marine...

2012-03-20

467

78 FR 66683 - Fisheries in the Western Pacific; Special Coral Reef Ecosystem Fishing Permit  

Federal Register 2010, 2011, 2012, 2013

...Fisheries in the Western Pacific; Special Coral Reef Ecosystem Fishing Permit AGENCY...significant impact for the issuance of a special coral reef ecosystem fishing permit...SUMMARY: NMFS issued a Special Coral Reef Ecosystem Fishing Permit that...

2013-11-06

468

76 FR 38618 - Proposed Information Collection; Comment Request; Coral Reef Conservation Program Survey  

Federal Register 2010, 2011, 2012, 2013

...Information Collection; Comment Request; Coral Reef Conservation Program Survey AGENCY...States (U.S.) jurisdictions containing coral reefs. Specifically, NOAA is seeking...related to the communities affected by coral reef conservation programs. The...

2011-07-01

469

Surfactants as bubble surface modifiers in the flotation of algae: dissolved air flotation that utilizes a chemically modified bubble surface.  

PubMed

In this paper we present an investigation into the use of bubbles modified with surfactants in dissolved air flotation (DAF). Bubble modification was investigated by dosing surfactants of varying character into the saturator of a DAF unit in turn. The cell removal efficiency only improved when using a cationic surfactant where optimum removal of Microcystis aeruginosa cells was obtained when using 0.0022-0.004 mequiv L(-1) surfactant. However, the magnitude of the removal differed according to the hydrophobicity of the surfactant. Typically, the more efficiently the surfactant adsorbed at the bubble interface, the better the removal efficiency. When the dose to saturator ratio was kept constant and the recycle ratio varied, the removal efficiency improved with increasing recycle ratio, reaching a maximum removal efficiency of 87% for M. aeruginosa. This value was comparable with that predicted by a theoretical model. The bubble collection efficiency of a maximum of two cells per bubble was constant irrespective of the influent cell number or recycle ratio. Treatment of additional species in this way revealed a relationship between increasing size and both increasing removal efficiency and decreasing surfactant dose, which is supported by theoretical relationships. PMID:18678021

Henderson, Rita K; Parsons, Simon A; Jefferson, Bruce

2008-07-01

470

Combined column and cell flotation process for the treatment of PAH contaminated hazardous wastes produced by an aluminium production plant.  

PubMed

The aluminium electrolytic plants generate PAH and fluoride contaminated wastes which are usually classified as hazardous material. These residues are generally disposed in secure landfill sites. A flotation cell process was previously developed to remove PAH from these aluminium industry wastes. The tests were done on composite samples made of particle size fractions under 50mm. The efficiency of the flotation cell process was demonstrated but the high quantity of concentrate produced (14.0%) during the air injection period, because of the solid entrainment, raised the treatment cost. The aim of this study was to reduce the entrainment of fine particles in order to obtain an efficient and economic technology. The process initially developed was modified: the smallest particle size fraction (<0.5mm) of the composite sample was treated in a flotation column, whereas the other particle size fractions (0.5-50mm) were treated in a flotation cell. The separated treatment allowed to reduce the entrainment during the air injection period of the flotation cell step from 14.0% to 10.1%. The optimum total solids of the pulp and cocamidopropylhydroxysultaine (CAS) concentration were 3.33% and 0.50% (ww(-1)) for the flotation column, and 15% and 0.25% (ww(-1)) for the flotation cell. This combined flotation process minimized the total entrainment which allowed a 23.6% abatement of the concentrate quantity initially produced, and reduced the PAH concentrations of the wastes under the authorized limit of 1000 mg kg(-1). PMID:19013712

Dhenain, Aurélie; Mercier, Guy; Blais, Jean-François; Chartier, Myriam

2009-06-15

471

Advanced control system for fine coal flotation. Final technical progress report, October 1, 1995--June 30, 1996.  

National Technical Information Service (NTIS)

A model-based flotation control scheme is being implemented to achieve optimal performance in the handling and treatment of fine coal. The control scheme monitors flotation performance through on-line analysis of ash content. Then, based on the economic a...

1996-01-01

472

Calibration and diagnostic accuracy of simple flotation, McMaster and FLOTAC for parasite egg counts in sheep  

Microsoft Academic Search

The present study was aimed at carrying out a calibration and a comparison of diagnostic accuracy of three faecal egg counts (FEC) techniques, simple flotation, McMaster and FLOTAC, in order to find the best flotation solution (FS) for Dicrocoelium dendriticum, Moniezia expansa and gastrointestinal (GI) strongyle eggs, and to evaluate the influence of faecal preservation methods combined with FS on

L. Rinaldi; G. C. Coles; M. P. Maurelli; V. Musella; G. Cringoli

2011-01-01

473

Flotation in inorganic electrolytes; the relationship between recover of hydrophobic particles, surface tension, bubble coalescence and gas solubility  

Microsoft Academic Search

The influence of a series of aqueous solutions of inorganic electrolytes on the flotation performance of graphite particles was determined. The results were related to the electrostatic interaction (as expressed in terms of the thickness of the electrostatic double layer) the surface tension and the solubility of gases in the electrolyte solutions. Overall, high flotation recoveries were attributed to an

R. J. Pugh; P. Weissenborn; O. Paulson

1997-01-01

474

Fine coal flotation of plant waste: An in-plant comparison -- columns vs. sub-a cell. Technical report, September 1-November 30, 1990.  

National Technical Information Service (NTIS)

The objective of this project is to compare the flotation effectiveness of the column flotation and the sub-aeration technology to clean very fine ((minus)100 mesh) coal in the waste streams of coal washing plants. The recent developments in the flotation...

H. P. Ehrlinger J. M. Lytle D. M. Rapp J. Stephenson D. Zipperian

1990-01-01

475

Crown-of-thorns starfish outbreaks on the Great Barrier Reef: a geological perspective based upon the sediment record  

Microsoft Academic Search

Over the last 30 years, the crown-of-thorns starfish (Acanthaster planci) has caused extensive damage to many reefs in the Great Barrier Reef Province. Surface sediment of two such reefs, John Brewer Reef and Green Island Reef, has high densities of A. planci skeletal elements relative to their abundance in the surface sediment of Heron Island Reef which, during the same

P. D. Walbran; R. A. Henderson; J. W. Faithful; H. A. Polach; R. J. Sparks; G. Wallace; D. C. Lowe

1989-01-01

476

The discovery of early Permian reef belt in east Kunlun and its significance  

Microsoft Academic Search

The early permian reef belt is distributed in the southern side of eastern Kunlun, north area of Qinghai-Tibet Plateau. The\\u000a core-reef facies of thc reel extends from Tuosuo Lake to Huashixia. Lots of reef breccia was found at the southern slope of\\u000a the mre-reef belt, and to the north of the reef belt there is back-reef limestone. Cacisponges, hydrozoa, bryozoa,Tabulozoa,

Wang Yongbiao; Zhang Kexing; Gong Yiming; Zhang Zhi; Luo Mansheng

1998-01-01

477

Mortality among sulfide ore miners  

SciTech Connect

Lung cancer mortality was studied during 1965-1985 in Outokumpu township in North Karelia, where an old copper mine was located. Age-specific lung cancer death rates (1968-1985) were higher among the male population of Outokumpu than among the North Karelian male population of the same age excluding the Outokumpu district (p less than .01). Of all 106 persons who died from lung cancer during 1965-1985 in Outokumpu township, 47 were miners of the old mine, 39 of whom had worked there for at least three years and been heavily exposed to radon daughters and silica dust. The study cohort consisted of 597 miners first employed between 1954 and 1973 by a new copper mine and a zinc mine, and employed there for at least 3 years. The period of follow-up was 1954-1986. The number of person-years was 14,782. The total number of deaths was 102; the expected number was 72.8 based on the general male population and 97.8 based on the mortality of the male population of North Karelia. The excess mortality among miners was due mainly to ischemic heart disease (IHD); 44 were observed, the expected number was 22.1, based on the general male population, and the North Karelian expected number was 31.2 (p less than .05). Of the 44 miners who died from IHD, 20 were drillers or chargers exposed to nitroglycerin in dynamite charges, but also to several simultaneous stress factors including PAHs, noise, vibration, heavy work, accident risk, and working alone. Altogether 16 tumors were observed in the cohort. Ten of these were lung cancers, the expected number being 4.3. Miners who had died from lung cancer were 35-64 years old, and had entered mining work between 1954 and 1960. Five of the ten lung cancer cases came from the zinc mine (1.7 expected). Three of them were conductors of diesel-powered ore trains.

Ahlman, K.; Koskela, R.S.; Kuikka, P.; Koponen, M.; Annanmaeki, M. (Department of Epidemiology and Biometry, Institute of Occupational Health, Helsinki (Finland))

1991-01-01

478

Optimized conditions for selective gold flotation by ToF-SIMS and ToF-LIMS  

NASA Astrophysics Data System (ADS)

This work describes a comprehensive characterization of the factors controlling the floatability of free gold from flotation test using reagents (collectors) at plant concentration levels. A relationship between the collectors loadings on gold particles and their surface composition has been established. The findings of this study show that silver activates gold flotation and there is a strong correlation between the surface concentration of silver and the loading of certain collectors. The organic surface analysis was done by ToF-SIMS while the inorganic surface analysis was carried out by time-of-flight laser ionization mass spectrometry (ToF-LIMS). The developed testing protocol based on ToF-LIMS and ToF-SIMS complementary surface analysis allows for optimization of the flotation scheme and hence improved gold recovery.

Chryssoulis, S. L.; Dimov, S. S.

2004-06-01

479

Development of innovative flotation processes for water treatment and waste-water reclamation. Technical report  

SciTech Connect

The engineering designs and applications of various newly developed flotation clarifiers (Supracell, Sandfloat, Sedifloat, Lakeguard, Float Skimmer, and Foamer) are presented. Supracell is a high-rate dissolved air flotation clarifier for industrial water-treatment and in-plant water recycle. Sandfloat is a package water treatment plant designed for treatment of surface water, ground water, or waste water. Sedifloat is a package plant from reclamation of process waste water or pretreatment of raw water containing heavy silts and/or high concentrations of suspended solids. Lakeguard is an extremely compact package plant for single families, factories, and small institutions. Both lake water and ground water can be properly treated by Lakeguard for potable applications and for treatment of septic-tank effluent. Foamer is a high-rate cost-effective dispersed air flotation clarifier. Float skimmer is specifically designed for applications in paper and pulp mills.

Krofta, M.; Wang, L.K.

1988-08-01

480

Separation of packaging plastics by froth flotation in a continuous pilot plant  

SciTech Connect

The objective of the research was to apply froth flotation to separate post-consumer PET (Polyethylene Terephthalate) from other packaging plastics with similar density, in a continuously operated pilot plant. A representative sample composed of 85% PET, 2.5% PVC (Polyvinyl Chloride) and 11.9% PS (Polystyrene) was subjected to a combination of alkaline treatment and surfactant adsorption followed by froth flotation. A mineral processing pilot plant, owned by a Portuguese mining company, was adapted for this purpose. The experimentation showed that it is possible to produce an almost pure concentrate of PET, containing 83% of the PET in feed, in a single bank of mechanical flotation cells. The concentrate grade attained was 97.2% PET, 1.1% PVC and 1.1% PS. By simulation it was shown that the Portuguese recycling industry specifications can be attained if one cleaning and one scavenger stages are added to the circuit.

Carvalho, Teresa, E-mail: teresa.carvalho@ist.utl.p [CERENA, Instituto Superior Tecnico, Av. Rovisco Pais, 1049-001 Lisbon (Portugal); Durao, Fernando; Ferreira, Celia [CERENA, Instituto Superior Tecnico, Av. Rovisco Pais, 1049-001 Lisbon (Portugal)

2010-11-15

481

The physical hydrogeology of ore deposits  

USGS Publications Warehouse

Hydrothermal ore deposits represent a convergence of fluid flow, thermal energy, and solute flux that is hydrogeologically unusual. From the hydrogeologic perspective, hydrothermal ore deposition represents a complex coupled-flow problem—sufficiently complex that physically rigorous description of the coupled thermal (T), hydraulic (H), mechanical (M), and chemical (C) processes (THMC modeling) continues to challenge our computational ability. Though research into these coupled behaviors has found only a limited subset to be quantitatively tractable, it has yielded valuable insights into the workings of hydrothermal systems in a wide range of geologic environments including sedimentary, metamorphic, and magmatic. Examples of these insights include the quantification of likely driving mechanisms, rates and paths of fluid flow, ore-mineral precipitation mechanisms, longevity of hydrothermal systems, mechanisms by which hydrothermal fluids acquire their temperature and composition, and the controlling influence of permeability and other rock properties on hydrothermal fluid behavior. In this communication we review some of the fundamental theory needed to characterize the physical hydrogeology of hydrothermal systems and discuss how this theory has been applied in studies of Mississippi Valley-type, tabular uranium, porphyry, epithermal, and mid-ocean ridge ore-forming systems. A key limitation in the computational state-of-the-art is the inability to describe fluid flow and transport fully in the many ore systems that show evidence of repeated shear or tensional failure with associated dynamic variations in permeability. However, we discuss global-scale compilations that suggest some numerical constraints on both mean and dynamically enhanced crustal permeability. Principles of physical hydrogeology can be powerful tools for investigating hydrothermal ore formation and are becoming increasingly accessible with ongoing advances in modeling software.

Ingebritsen, Steven E.; Appold, M. S.

2012-01-01

482

Maintenance of fish diversity on disturbed coral reefs  

Microsoft Academic Search

Habitat perturbations play a major role in shaping community structure; however, the elements of disturbance-related habitat\\u000a change that affect diversity are not always apparent. This study examined the effects of habitat disturbances on species richness\\u000a of coral reef fish assemblages using annual surveys of habitat and 210 fish species from 10 reefs on the Great Barrier Reef\\u000a (GBR). Over a

S. K. Wilson; A. M. Dolman; A. J. Cheal; M. J. Emslie; M. S. Pratchett; H. P. A. Sweatman

2009-01-01

483

Digital analysis of multispectral airborne imagery of coral reefs  

Microsoft Academic Search

The digital airborne sensor, CASI (Compact Airborne Spectrographic Imager) has considerable potential for mapping marine\\u000a habitats. Here we present an account of one of the first coral reef applications. The CASI was flown over reefs of the Turks\\u000a and Caicos Islands (British West Indies) and set to view 1?m pixels in 8 spectral bands. In addition, reef habitats were sampled

P. J. Mumby; E. P. Green; C. D. Clark; A. J. Edwards

1998-01-01

484

Quantifying climatological ranges and anomalies for Pacific coral reef ecosystems.  

PubMed

Coral reef ecosystems are exposed to a range of environmental forcings that vary on daily to decadal time scales and across spatial scales spanning from reefs to archipelagos. Environmental variability is a major determinant of reef ecosystem structure and function, including coral reef extent and growth rates, and the abundance, diversity, and morphology of reef organisms. Proper characterization of environmental forcings on coral reef ecosystems is critical if we are to understand the dynamics and implications of abiotic-biotic interactions on reef ecosystems. This study combines high-resolution bathymetric information with remotely sensed sea surface temperature, chlorophyll-a and irradiance data, and modeled wave data to quantify environmental forcings on coral reefs. We present a methodological approach to develop spatially constrained, island- and atoll-scale metrics that quantify climatological range limits and anomalous environmental forcings across U.S. Pacific coral reef ecosystems. Our results indicate considerable spatial heterogeneity in climatological ranges and anomalies across 41 islands and atolls, with emergent spatial patterns specific to each environmental forcing. For example, wave energy was greatest at northern latitudes and generally decreased with latitude. In contrast, chlorophyll-a was greatest at reef ecosystems proximate to the equator and northern-most locations, showing little synchrony with latitude. In addition, we find that the reef ecosystems with the highest chlorophyll-a concentrations; Jarvis, Howland, Baker, Palmyra and Kingman are each uninhabited and are characterized by high hard coral cover and large numbers of predatory fishes. Finally, we find that scaling environmental data to the spatial footprint of individual islands and atolls is more likely to capture local environmental forcings, as chlorophyll-a concentrations decreased at relatively short distances (>7 km) from 85% of our study locations. These metrics will help identify reef ecosystems most exposed to environmental stress as well as systems that may be more resistant or resilient to future climate change. PMID:23637939

Gove, Jamison M; Williams, Gareth J; McManus, Margaret A; Heron, Scott F; Sandin, Stuart A; Vetter, Oliver J; Foley, David G

2013-01-01

485

Calcification and organic production on a Hawaiian coral reef  

Microsoft Academic Search

Net ecosystem calcification rates (NEC) and net photosynthesis (NP) were determined from CO2 seawater parameters on the barrier coral reef of Kaneohe Bay, Oahu, Hawaii. Autosamplers were deployed to collect samples on the barrier reef every 2h for six 48-hour deployments, two each in June 2008, August 2009, and January\\/February 2010. NEC on the Kaneohe Bay barrier reef increased throughout

K. E. F. Shamberger; R. A. Feely; C. L. Sabine; M. J. Atkinson; E. H. DeCarlo; F. T. Mackenzie; P. S. Drupp; D. A. Butterfield

2011-01-01

486