Note: This page contains sample records for the topic reef ore flotation from Science.gov.
While these samples are representative of the content of Science.gov,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of Science.gov
to obtain the most current and comprehensive results.
Last update: November 12, 2013.
1

Aerosol flotation of low-grade refractory molybdenum ores  

NASA Astrophysics Data System (ADS)

The characteristics of aerosol flotation, which include the effect of the concentration and particle size of kerosene aerosol on the molybdenum (Mo) flotation index and the effect of kerosene aerosol dosing method on the kerosene dosage and flotation time, were studied in the flotation of low-grade refractory molybdenum ores using kerosene aerosol. The results revealed that the particle size and concentration of kerosene aerosol had little effect on the Mo grade but had significant effect on the Mo recovery. A smaller particle size and a lower concentration of kerosene aerosol were beneficial to the Mo aerosol flotation. For the received Mo ore samples, the optimized particle size of kerosene aerosol was 0.3-2 ?m and the optimized aerosol concentration was 14 mg/L. The compressed air atomizer had a more uniform distribution of aerosol particles than the ultrasonic atomizer, and the aerosol concentration was controlled easily, so the compressed air atomizer was more suitable for the research of aerosol flotation. Compared with conventional flotation in which kerosene was directly added into the ore pulp, the flotation time was reduced by ˜30%, and the dosage was decreased by ˜20% in aerosol flotation, while the Mo flotation index was similar.

Xu, Tao; Sun, Chun-bao

2012-12-01

2

ARMA type model for copper ore flotation  

Microsoft Academic Search

The processes of mineral processing can be regarded as discrete processes. Discrete processes can be described using time series. The difference equations derived from the theory of time series dynamics, as well as ARMA and ARMAX models, are used to describe processes of minerals flotation. Several models are attempted ARMAX for rougher flotation of copper, and a bank of cleaning

K. Trybalski; J. Ciep?y

2000-01-01

3

Column Flotation of Multiple Products from a Fluorite Ore.  

National Technical Information Service (NTIS)

The U.S. Bureau of Mines investigated column flotation for recovery of a high-grade fluorite (CaF2) concentrate and byproduct concentrates from the Fish Creek fluorite deposit in Eureka County, NV. The recovery scheme consisted of (1) grinding the ore to ...

M. R. Peterson L. J. Duchene M. B. Shirts

1990-01-01

4

Upgrading of calcareous phosphate ores by flotation: Effect of ore characteristics  

Microsoft Academic Search

Sedimentary phosphates contain-besides the phosphate minerals-, various associated gangue minerals such as: clays, silica, calcareous minerals (mainly calcite and dolomite), carbonaceous matter, iron oxides and\\/or pyrite. The common practiced flow-sheets for concentrating these types of phosphate ores consist of a combination of various mineral processing units such as: crushing and screening, attrition, washing, magnetic separation, and\\/or flotation. However, none of

A.-Z. M. Abouzeid; A. T. Negm; D. A. Elgillani

2009-01-01

5

Modified reagent mode in porphyry copper-molybdenum ore flotation  

Microsoft Academic Search

Test data on the selective reagent modes at bulk flotation cycle and modified carboxymethylcellulose (CMC) at a selection\\u000a cycle for the bulk copper-molybdenum concentrate. The selected reagent mode at a bulk flotation cycle with industrial kerosene\\u000a and Beraflot as collectors and OPSB as a frother made it possible to recover 87 % of copper and 82 % of molybdenum into

V. A. Bocharov; L. S. Khachatryan; V. A. Ignatkina; Zh. Baatarkhuu

2008-01-01

6

A model of conditioning in the flotation of a mixture of pyrite and chalcopyrite ores  

Microsoft Academic Search

Collector control in flotation plants is an important factor, which affects recovery and grade. The performance of a control system can be improved by calculating the collector requirement using a kinetic model of conditioning, which is capable of predicting the adsorption density of the collector on the surfaces of ores. In this paper, a semi-empirical model for the kinetics of

H Kuopanportti; T Suorsa; O Dahl; J Niinimäki

2000-01-01

7

The infrared spectra of amine collectors used in the flotation of iron ores  

Microsoft Academic Search

Inverse froth flotation is the most used concentration method for itabiritic iron ores, where the quartz gangue is floated, and the iron oxides are kept depressed by starches; medium-chain etheramine acetates are the cationic collectors used. Since there is a lack of thorough studies on the infrared spectroscopy of these reagents (and by other similar techniques), an investigation on the

R. M. F. Lima; P. R. G. Brandao; A. E. C. Peres

2005-01-01

8

Role of bacterial interaction and bioreagents in iron ore flotation  

Microsoft Academic Search

Interaction between Paenibacillus polymyxa and iron ore minerals such as hematite, corundum, calcite, quartz and kaolinite brought about significant surface chemical changes on all the minerals. Quartz and kaolinite were rendered more hydrophobic, while the other three minerals became more hydrophilic after bacterial interaction. Predominance of bacterial polysaccharides on interacted hematite, corundum and calcite and of proteins on quartz and

K. A Natarajan; Namita Deo

2001-01-01

9

Flotation of a complex sulphide ore I. Cu Zn selectivity control by adjusting pulp potential with different gases  

Microsoft Academic Search

To investigate the possibility of using gases with varying oxygen activity and their influence on copper-zinc selectivity, flotation tests were done in a mechanical laboratory cell on a fine-grained complex sulphide ore with high pyrite and pyrrhotite content. The pulp environment was modified by changing the grinding media and by using different gases in the pre-conditioning a flotation steps. A

X.-M Yuan; B. I Pålsson; K. S. E Forssberg

1996-01-01

10

Flotation behaviour of gold during processing of porphyry copper-gold ores and refractory gold-bearing sulphides  

Microsoft Academic Search

Porphyry copper ores and gold-bearing sulphides are significant contributors to overall world gold production. Flotation is the principal process for pre-concentration of the sulphides, for subsequent smelting, roasting or hydrometallurgical treatment.Lakefield Research has had the opportunity to study ores from many large deposits, both new discoveries and existing operations. Research was aimed at improved metal recoveries by applying new concepts

S. M. Bulatovic

1997-01-01

11

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

NASA Astrophysics Data System (ADS)

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

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

2010-12-01

12

Pentlandite–feldspar interaction and its effect on separation by flotation  

Microsoft Academic Search

The major loss of PGM and base metals in beneficiation of the Merensky Reef ore occurs during the separation of the siliceous gangue from the base metal sulphides and PGM minerals by selective flotation. The predominant gangue minerals in Merensky ores fed to the PGM concentrators are pyroxene and feldspar. Other important gangue minerals are talc and chlorite. A significant

V Malysiak; C. T O'Connor; J Ralston; A. R Gerson; L. P Coetzer; D. J Bradshaw

2002-01-01

13

Dynamic simulator of a rougher flotation circuit for a copper sulphide ore  

Microsoft Academic Search

This paper presents a dynamic flotation simulator intended for designing and testing automatic control strategies, for evaluating the transient behaviour of the flotation process, and for training purposes. The simulator is based on a non-linear dynamic model that is derived from phenomenological and empirical relationships. It incorporates a new way of representing the loading of the bubbles with the various

A. Casali; G. Gonzalez; H. Agusto; G. Vallebuona

2002-01-01

14

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

15

Development of a Model-Based Control Strategy for Copper-Ore Flotation.  

National Technical Information Service (NTIS)

During the last decade, it has been established the conventional flotation control strategies based on classical control theory result in significant increases in grade, recovery, and operating cost savings. In the current report, description of an advanc...

J. A. Herbst R. Zaragoza O. A. Bascur

1986-01-01

16

Flotation Processes.  

National Technical Information Service (NTIS)

The theory and various types of flotation processes are presented. The topics include: buoyance, air solubility, bubble particle contact, pressure flotation, vacuum flotation, dispersed air flotation, electroflotation, plain flotation, oil-water separatio...

I. J. Kumar W. E. Eustance L. K. Wang

1988-01-01

17

Potential control in the flotation of sulphide minerals and precious metals  

Microsoft Academic Search

In this work a method based on the use of flotation gases (air, nitrogen, etc.) is presented for potential controlled flotation. Examples of the flotation of a complex sulphide ore, and two gold ores are presented. With this control method, the potential could be kept constant within 2 to 5 mV throughout the flotation stage. The selectivity in the flotation

V. V. Hintikka; J. O. Leppinen

1995-01-01

18

Influence of sodium thiosulphate on oxidation of sulphide minerals during selective flotation of copper-nickel ores  

Microsoft Academic Search

The studies of sulphur distribution in oxidation products of pyrrhotite and chalcopyrite being components of Cu-Ni ores showed\\u000a that the elementary sulphur — sulphoxide ion ratio on the mineral surface and in the liquid phase of mineral suspensions changes\\u000a in the presence of sodium thiosulphate. Sodium thiosulphate exhibits properties of a reducing agent and prevents formation\\u000a of hydrophobic elementary sulphur

T. N. Matveeva; N. K. Gromova

2006-01-01

19

Effect of carboxymethyl cellulose and ionic strength on stability of mineral suspensions in potash ore flotation systems.  

PubMed

The adsorption of sodium carboxymethyl cellulose from aqueous solutions varying in ionic strength from that of distilled water to 50% NaCl/KCl brine (about 3.5 mol/dm(3)) onto illite and dolomite has been studied. The purpose of this work was to investigate the solvency effects in the phenomena underlying the potash flotation process that is carried out in saturated brine. Based on viscosity measurements, the adsorption results were analyzed in terms of a simple model of polymer macromolecules in solution. Suspension stability measurements carried out concomitantly with adsorption tests showed the ranges of carboxymethyl cellulose concentration over which the tested suspensions either were aggregated or were restabilized. PMID:12686172

Pawlik, M; Laskowski, J S; Ansari, A

2003-04-15

20

Evaluation of Methods for Recovering Potash from Carnallite Ore.  

National Technical Information Service (NTIS)

The Bureau of Mines investigated two methods for recovering potash from carnallite ore in continuous 100-lb/h flotation units. In the insoluble-slimes flotation procedure, insoluble slimes were removed by flotation prior to potash flotation. In the direct...

D. G. Foot J. L. Huiatt

1984-01-01

21

Lead activation of sphalerite during galena flotation  

Microsoft Academic Search

Kinetic studies on the flotation of a fine-grained complex lead-zinc ore showed that sphalerite exhibits considerable floatability during the later stages of galena flotation, causing a loss of zinc to lead concentrate. The lead concentrates obtained toward the end of the second lead rougher flotation were examined by X-ray photoelectron spectroscopy (XPS). The results showed that the lead-to-zinc atomic ratios

C. I Basilio; I. J Kartio; R.-H Yoon

1996-01-01

22

Control of a flotation column using fuzzy logic inference  

Microsoft Academic Search

This paper describes a fuzzy controller that was developed for the control, in real time, of three main variables of the column flotation process. Column flotation is a solid–solid separation process based on the physical and chemical properties of mineral particle surfaces. It is applied to the concentration of low grade ores and to ores that require very fine grinding

M. Teresa Carvalho; Fernando Durão

2002-01-01

23

Techniques of copper recovery from Mexican copper oxide ore  

Microsoft Academic Search

Mexican copper ore is a mixed ore containing mainly copper oxide and some copper sulfide that responds well to flotation. The joint techniques of flotation and leaching were studied. The results indicate that an ore containing 19.01% copper could be obtained at a recovery ratio of 35.02% by using sodium sulfide and butyl xanthate flotation. Over 83.33% of the copper

Zhan-fang CAO; Hong ZHONG; Guang-yi LIU; Shu-juan ZHAO

2009-01-01

24

Flotation machine  

SciTech Connect

A flotation machine is described for beneficiating minerals comprising: a vertical cylindrical chamber for circulating a flotation pulp; a downwardly tapered bottom connected to said vertical cylindrical chamber; feed pipe means for feeding the flotation pulp carrying mineral particles of fine fraction, particles of the useful ingredient of the fine fraction being capable of floating up from the volume of said aerated pulp; discharge pipe means connected to the tapered bottom near its lowest point for discharging gangue; an annular trough for collecting froth concentrate at the top of said chamber; a group of frustoconical shells each having bases of different diameters and a tapered surface secured axially in said chamber and spaced equidistantly from one another height wise of said chamber; aerator means for aerating the flotation pulp secured to the walls of said chamber and communicating therewith to provide aerated water into said chamber; means for feeding mineral particles of coarse fraction, particles of the useful ingredient of the coarse fraction being capable of floating in the froth layer of the flotation pulp, in the form of a hydrocyclone having a cylindrical casing positioned axially over said chamber and a downwardly tapering outlet directed downwardly to feed the coarse particles to said chamber; feed pipe means for feeding the flotation pulp carrying mineral particles of coarse fraction positioned tangentially at said cylindrical casing of the hydrocyclone; and evacuation means for evacuating the liquid phase of the flotation pulp positioned tangentially at said casing of the hydrocyclone over said feed pipe means and connected to said feed pipe means for feeding the flotation pulp carrying mineral particles of the fine fraction.

Zlobin, M.N.; Permyakov, G.P.; Nemarov, A.A.; Metsik, V.M.; Medetsky, J.V.; Taraban, N.T.

1993-08-10

25

Selective Flotation of Dolomitic Limestone Impurities from Florida Phosphates.  

National Technical Information Service (NTIS)

The primary objective of the investigation was to demonstrate the applicability of the new fatty acid flotation technique for processing both low-(matrix or sand fraction) and high-grade (pebble fraction) siliceous dolomitic Florida phosphate ores. The se...

J. Hanna I. Anazia

1990-01-01

26

Evaluation of the largest flotation cells at Minera Los Pelambres  

Microsoft Academic Search

The concentrator at Minera Los Pelambres currently processes 130,000tpd of Cu\\/Mo ore. The rougher circuit originally consisted of four flotation banks. In August 2006 the rougher circuit was enlarged adding two flotation banks, each one consisting of 5 cells of 250m3.This paper describes the metallurgical comparison between the new flotation banks and the old ones (130m3 cells) operating in parallel.

J. B. Yianatos; F. Henríquez; L. Tapia

2008-01-01

27

A review of the flotation of native gold and electrum  

Microsoft Academic Search

Native gold and electrum are naturally-occurring alloys containing gold and silver and a little copper. They are the most common and important forms of gold in ores. Their recovery by gravity concentration, cyanidation, or flotation from ores, typically containing 0.1–20 g\\/t Au is of great commercial importance. This paper reviews the literature on their recovery by flotation. Little mention is

G. C. Allan; J. T. Woodcock

2001-01-01

28

Flotation riser  

SciTech Connect

A flotation riser is described comprising a series of annular housings being interconnected to form buoyancy chambers surrounding an open central bore, means for connecting the lower of the housings to a subsea location, means for supporting the upper of the housings from a floating structure, a free-standing tubular string extending through the central bore of the series of housings with connection therebetween only at the lower and upper ends thereof, and having an external diameter sightly smaller than the internal diameter of the central bore and to allow relative freedom of axial movement therebetween, and means supplying a gas to the chambers to provide each of the chambers with a preselected amount of buoyancy. The method is described of providing an emergency deballasting system for a flotation riser having a plurality of flotation chambers including the steps of supplying gas to a plurality of the lower of the flotation chambers, retaining gas in the plurality of lower chambers as an emergency source of deballasting gas, and remotely releasing gas from the plurality of lower chambers into the chambers above them to deballast the chambers under emergency conditions and provide sufficient buoyancy to maintain the flotation riser in a substantially vertical position above its connection to a subsea wellhead when its upper end is free of all connections.

Bartholomew, R.E.; Pettus, R.G.; Schnitzer, E.; Fisher, E.A.

1987-03-03

29

Selective Flotation of South African Chromite.  

National Technical Information Service (NTIS)

In the investigation an attempt was made to find a general method for the selective separation of chromite from the gangue constituents of its ore by flotation. Various tests were conducted on Maandagshoek UG-2, Pandora UG-2, Grasvally, Winterveld, and St...

E. Yigit S. A. Allison

1983-01-01

30

RESEARCH AND PROCESS INVESTIGATIONS ON LAKEVIEW ORE, LAKE COUNTY, OREG  

Microsoft Academic Search

ABS>Ore from the Lakeview Mining Co. was tested in the pilot plant amd ; laboratory. The testing included grinding, leaching, countercurrent decantation, ; solvent extraction, precipitation, flotation, and molybdenum recovery. (W.L.H.);

I. L. Nichols; K. E. Tame; J. R. Ross; J. B. Rosenbaum

1957-01-01

31

Dissolution of wollastonite and its flotation and surface interactions with tallow1,3-diaminopropane (duomeen T)  

Microsoft Academic Search

Wollastonite finds an important place among industrial minerals due to its high chemical and thermal resistance and also as a substitute for asbestos. With the depletion of high-grade ores and increased demand, it becomes inevitable to process low-grade ores. Flotation can be employed effectively for processing these ores. Flotation behavior of wollastonite was studied using tallow-1,3-diaminopropane as collector in the

S. Prabhakar; K. Hanumantha Rao; W. Forsling

2005-01-01

32

Nonparametric density estimation of bubble size distribution for monitoring mineral flotation process  

Microsoft Academic Search

The mineral separation efficiency of flotation process depends very much on the surface properties of feed ore and addition of chemical reagents. Machine vision based analysis of froth appearance is considered as an indication of flotation performance. Bubble structure obtained by watershed segmentation scheme is used to determine the amount of reagent. To explore bubble size distribution, nonparametric wavelet thresholding

Chunhua Yang; Canhui Xu; Weihua Gui; Jianjiang Du

2009-01-01

33

Modeling of column flotation  

Microsoft Academic Search

Many investigators believe that column flotation cells offer significant advantages over standard mechanical machines for the flotation of fine particles. However, because of their unique design and operation, conventional techniques for flotation cell scale-up and design cannot be applied to columns. In an attempt to help alleviate this problem, a population balance model based on first principles has been developed

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

1987-01-01

34

Ore Minerals  

NSDL National Science Digital Library

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

Perkins, Dexter

35

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

2013-03-13

36

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

37

Ore and coal beneficiation method  

SciTech Connect

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

Abadi, K.

1987-10-27

38

Modeling of column flotation  

SciTech Connect

Many investigators believe that column flotation cells offer significant advantages over standard mechanical machines for the flotation of fine particles. However, because of their unique design and operation, conventional techniques for flotation cell scale-up and design cannot be applied to columns. In an attempt to help alleviate this problem, a population balance model based on first principles has been developed for fine particle flotation in a column. Two different terms have been considered in the model, i.e., transport and rate. Transport terms, incorporating fluid flow and buoyancy, are used to describe the movement of air bubbles, unattached particles and bubble-particle aggregates along the length of the column. Rate terms, which describe the bubble-particle attachment process, have been derived from first principle considerations. Because the model is based on first principles, it can be useful for the design, control, optimization and scale-up of column flotation cells. 9 refs., 12 figs.

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

1987-01-01

39

Optimization of Copper Ore Concentration Processing by Means of Radioactive Tracers  

Microsoft Academic Search

Flotation benefication of polymetallic ores in the Polish Lower Silesian Basin was taken as an example for the optimization of copper ore processing using radioactive tracer. An original stochastic mathematical model (stream model) was proposed to minimize copper losses in tailing. A detailed procedure of measurement was presented as well as the experimental data and their interpretation. On the basis

L. Petryka; K. Przewlocki

1989-01-01

40

A hybrid intelligent optimal control method for complex flotation process  

Microsoft Academic Search

In mineral industry, flotation is used to separate utilised ore from gangue. The relationships between the technical indexes, i.e. the concentrate grade and the tailing grade, and the reagent feeding appear to have strong non-linearities and uncertainties in dynamic behaviours, which can hardly be described using any accurate mathematical model. For non-automatic and non-precision of manual control of reagent feeding,

Tianyou Chai; Zeng-Xian Geng; Heng Yue; Hong Wang; Chun-Yi Su

2009-01-01

41

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.

42

The Recovery of Pyrite from Gold Ore by Gravity Separation.  

National Technical Information Service (NTIS)

Pilot-plant tests on a sample of ore from a gold mine in the Orange Free State indicated that gold extractions can be increased from 87,4 to 94 percent. This is below the extraction of 96 percent that can be obtained by flotation, but gravity separation h...

R. N. Guest

1982-01-01

43

Gold-bearing reefs of the Witwatersrand Basin: A model of synsedimentation hydrothermal formation  

Microsoft Academic Search

The current concepts concerning the genesis of the unique ore-bearing reefs of the Witwatersrand Basin and its gold resource\\u000a potential are considered. The results of microscopic examination of ore from the Black, Ventersdorp Contact, Carbon Leader,\\u000a and Vaal reefs, as well as of thermobarometric study of quartz, are presented. A model of synsedimentation hydrothermal origin\\u000a of the reefs in the

Yu. G. Safonov; V. Yu. Prokof’ev

2006-01-01

44

Low energy ballasted flotation.  

PubMed

A novel process which involves the replacement or supplementation of bubbles in the dissolved air flotation process with low density beads is presented. The work comprised a series of bench-scale flotation trials treating three commonly encountered algal species (Microcystis, Melosira and Chlorella) that were removed in a flotation cell configured as either: conventional dissolved air flotation (DAF); ballasted flotation using low density 70 microm glass beads with a density of 100 kg m(-3); or a hybrid process of ballasted flotation combined with conventional DAF. Results indicated that the bead only system was capable of achieving better residual turbidity than standard DAF at bead concentrations of 500 mg L(-1). Addition of beads in combination with standard DAF reduced turbidity further to even lower residual turbidity levels. Algae removal was improved when glass beads were dosed, but removal was dependent on algal species. Microcystis was removed by 97% for bead only systems and this removal did not change significantly with the addition of air bubbles. Melosira was the next best removed algae with bead only dosed systems giving similar removals to that achieved by standard DAF using a 10% air recycle ratio (81 and 76% removal respectively). Chlorella was the least well removed algae by bead only systems (63% removal). However, removal was rapidly improved to 86% by the addition of air bubbles using only a 2% recycle ratio. Energy estimations suggested that at least a 50% energy reduction could be achieved using the process offering a potential route for future development of low energy separation processes for algae removal. PMID:19524997

Jarvis, P; Buckingham, P; Holden, B; Jefferson, B

2009-05-15

45

An interactive dynamic flotation model framework  

Microsoft Academic Search

A variety of novel flotation technologies have become available in recent years. However, very little research is been done on the hydrodynamics effects on metal recovery. A comprehensive dynamic flotation model was presented at the IMPC 1982. It was the first time that the particle\\/bubble and water transport description and flotation cell hydrodynamic of flotation were linked. A dynamic flotation

O. A. Bascur

2000-01-01

46

Visual information model based predictor for froth speed control in flotation process  

Microsoft Academic Search

Image processing sensors are emerging as an important measurement option in mineral processing, mainly due to their non-intrusive characteristics. Their principal application areas have been the determination of ore size distributions in grinding and froth features in flotation. The incorporation of visual information in control loops is the logical step. However, the excessive processing required brings a new problem that

Felipe Núñez; Aldo Cipriano

2009-01-01

47

Devonian reefs  

SciTech Connect

Three reef settings in northern Alberta and British Columbia were examined: (1) shelf edge, in the Clarke Lake shale basin; (2) open-marine pinnacle, in the Clarke Lake shale basin; and (3) restricted basin pinnacle, in the Shekilie evaporite basin. The shelf-edge reef tends to be water prone and does not offer the same reserves potential as pinnacle reefs; therefore, it is not examined in detail. The pinnacle reefs in the open-marine setting tend to be gas prone, whereas the pinnacle reefs in the restricted basin setting tend to be oil prone. Seismic models were generated from geologic cross sections over existing, economically producing reef anomalies. Seismic responses from these models were then examined, and criteria for reef identification established. For the acid test, seismic anomalies that were tested by the drill bit were examined, and the validity of the reef identification criteria was confirmed. Examples include both economic successes and failures. A different set of criteria for pinnacle reef identification were established for open-marine and restricted basin settings. Criteria are not universally applicable, so each basin will have a different set. Detecting the content and amount of porosity in reefs using seismic studies is elusive at best and remains a challenge to the explorationist.

Kuhme, A.K.

1986-05-01

48

Electrokinetic potential of flotation pulps  

SciTech Connect

Studies have been done on the possibility of intensifying flotation processes by electrical treatment of flotation pulps. The electrokinetic potential is a parameter which may characterize the flotation properties of pulps. In this paper, the authors obtain calculation relationships for determining the electrokinetic potential from the results of measuring sedimentation potential. The equations obtained are used to study both sedimentationally stable pulps and sedimentationally unstable coarsely dispersed suspensions.

Mis'nik, V.A.

1988-03-01

49

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

50

Automatic Control of Flotation Columns  

Microsoft Academic Search

\\u000a Since their first commercial application for mineral separation in the early 1980s, flotation columns have become a standard\\u000a piece of equipment in mineral concentrators particularly for cleaning operations. This chapter presents and discusses the\\u000a most recent advances in instrumentation and automatic control of flotation columns. It also examines how current industrial\\u000a practice could benefit from recent academic developments in these

René del Villar; André Desbiens; Miguel Maldonado; Jocelyn Bouchard

51

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.

52

Coal cleaning by froth flotation  

SciTech Connect

A number of experiments were conducted to determine the flotation characteristics of Iowa coals in which various conditions were applied to study the effect of different parameters such as frother dosage, oily collectors, pyrite depressants, and various combinations of these reagents. Flotation tests were also conducted with Appalachian coals for comparison. Iowa coals did not respond as well to froth flotation as Appalachian coals. Although Iowa coal floated very flowly and incompletely with only a frother (methyl isobutyl carbinol or MIBC), it floated rapidly when a large dosage of an oily collector (No. 200 LLS fuel oil) was employed in addition. No. 1 fuel oil was not nearly as effective as a collector for this application. The order of addition of flotation reagents appeared very important for achieving a high recovery of Iowa coal. Appalachian coals floated rapidly with only a frother or an alkaline solution. A small amount of an oily collector increased the recovery of Appalachian coals significantly. The results of these flotation experiments showed that little mineral matter was removed when a high recovery was achieved. The use of ultrasonics did seem to improve mineral matter liberation. Bubble-particle attachment was studied from a theoretical view point. This study showed that the mechanism of attachment differs depending on the relative size of bubbles and particles. The study indicated that micro-bubbles could separate mineral matter from low rank coal more selectively than macro-bubbles could. A general kinetic model was proposed to represent the rate of flotation of coal. For two Appalachian coals, the model successfully represented the flotation kinetics of uniformly sized coal and for coal consisting of two sizes of particles. 115 references, 33 figures, 34 tables.

Han, C.

1984-01-01

53

33 CFR 183.302 - Flotation requirements.  

Code of Federal Regulations, 2013 CFR

...SECURITY (CONTINUED) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Flotation Requirements for Outboard Boats Rated for Engines of 2 Horsepower or Less...302 Flotation requirements. Each boat to which this subpart applies must be...

2013-07-01

54

33 CFR 183.322 - Flotation materials.  

Code of Federal Regulations, 2013 CFR

...Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Flotation Requirements for Outboard Boats Rated for Engines of 2 Horsepower or Less General § 183.322 Flotation...

2013-07-01

55

Reef grief  

NASA Astrophysics Data System (ADS)

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

2011-10-01

56

Frothless ion flotation of some trivalent actinides  

Microsoft Academic Search

Frothless ion flotation of amerlcium in the form of anionic complexes ; with citric acid, with the aid of the cationic collector (cetylpyridynium ; bromide), was studied as a function of citric acid concentration, flotation time, ; and hydrogen ion concentration. Flotation of microcolloidal amerlcium hydroxides ; from aqueous solutions as a function of hydrogen ion concentration was also ;

Z. Szeglowski; M. Bittner-Jankowska; J. Mikulski; T. Machej

1973-01-01

57

Floc flotation of galena and sphalerite fines  

Microsoft Academic Search

The flotation of galena and sphalerite fines in the form of flocs, which is termed floc flotation, has been studied in the present work. The flocs formed through hydrophobic flocculation induced by potassium amyl xanthate (PAX) and kinetic energy input. The studies were performed on single minerals of ?20 ?m size by using micro-flotation and floc size measurements. Several parameters,

S. Song; A. Lopez-Valdivieso; J. L. Reyes-Bahena; C. Lara-Valenzuela

2001-01-01

58

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

59

Selective detachment process in column flotation froth  

Microsoft Academic Search

The selectivity in flotation columns involving the separation of particles of varying degrees of floatability is based on differential flotation rates in the collection zone, reflux action between the froth and collection zones, and differential detachment rates in the froth zone. Using well-known theoretical models describing the separation process and experimental data, froth zone and overall flotation recovery values were

Rick Q. Honaker; Ahmet V. Ozsever; B. K. Parekh

2006-01-01

60

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

61

Jurassic Reef Park  

NSDL National Science Digital Library

Dr. Reinhold Leinfelder of the University of Stuttgart, Germany created this interesting site in English and German, offering a "virtual trip to the reefs of the Jurassic Period." In the Introduction, viewers will find background material and comparisons of modern and ancient reefs. Further information is provided in the sections on reef architecture, reef formation, Jurassic reefs, and reefs and global climate change. Although the English language is slightly quirky, the content and images more than compensate, making this a worthwhile site.

62

Web Reef Advisory System  

NSDL National Science Digital Library

The Web Reef Advisory System (WRAS) was developed by ReefBase and Reef Check, in collaboration with the Coastal Resources Center at the University of Rhode Island and the Department of Biological Sciences at the University of Southern California, as "an online application to input, view, and analyse Reef Check survey data. It calculates indicators of how good or bad a shape a particular reef is in, and what the underlying causes may be, based on Reef Check surveys." WRAS allows users to view, analyze, and add (registration required) data. Please note that site users must complete a free and brief registration process before they are granted full access to the Reef Check website. Other site offerings include an interactive Reef Check GIS feature (see website for browser requirements), and The Reef Check Barometer of Global Reef Condition which provides assessments of different regions based on Reef Check Indicators.

63

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

64

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

65

Proceedings: Artificial Reef Conference. Artificial Reefs Around the World.  

National Technical Information Service (NTIS)

The section, Artificial Reefs Around the World, includes the following articles 'Artificial Reefs in France', 'Some Problems that may be Faced in the Construction of an Artificial Reef', 'Historical Review of Artificial Reef Activities in Japan', and 'A B...

W. H. Clark

1974-01-01

66

Fine Particle Flotation in a Centrifugal Force Field.  

National Technical Information Service (NTIS)

The effect of a centrifugal force field on hydrodynamic characteristics, flotation kinetics and separation behavior was examined. Flotation devices were designed that combine a centrifugal force field and flotation action in one apparatus. The relation be...

H. M. G. C. Tils

1990-01-01

67

Flotation of aluminosilicate minerals using alkylguanidine collectors  

Microsoft Academic Search

The flotation mechanism of aluminosilicate minerals using alkylguanidine collectors was studied through flotation experiments, Zeta potential measurements and FT-IR spectrum analysis. It is shown that kaolinite, illite and pyrophyllite all exhibit good floatability with alkylguanidines as collectors at pH 4–12. The flotation recoveries rise with the increase of the carbon chain length. Isoelectric point(IEP) is determined to be 3.5, 3.0

Feng GUAN; Hong ZHONG; Guang-yi LIU; Sheng-gui ZHAO; Liu-yin XIA

2009-01-01

68

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

69

Microbubble flotation of fine coal. Final report  

SciTech Connect

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

Yoon, R. H.

1984-03-01

70

POTENTIAL CONTROLLED FLOTATION OF SARCHESHMEH MOLYBDENITE  

Microsoft Academic Search

2 Yazd University, Yazd, I. R. of Iran Abstract- Molybdenite flotation in the Sarcheshmeh Copper Complex was studied as a function of pulp potential, controlled using two types of sodium sulfide, a mineral origin and a chemical nature. Air and either plant or laboratory nitrogen were used as flotation careers. Potential readings took place in rougher cells, as it was

M. KOLAHDOOZAN; H. NOORI

71

MODEL PREDICTIVE CONTROL FOR FLOTATION PLANTS  

Microsoft Academic Search

This contribution summarizes the results of a project for optimization of a froth flotation circuit. A model predictive control based approach has been developed and tested on a zinc flotation circuit in Sweden. The basic idea is to use air flows and chemicals to control the concentrate in the product and in the tailing. The activities in the project covered

M. Lundh; S. Gaulocher; J. Pettersson; H. Lindvall; E. Gallestey

72

Advanced Control System For Fine Coal Flotation.  

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...

1998-01-01

73

Advanced control system for fine coal flotation.  

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 tailings ash content. Then, based on an on...

G. H. Luttrell G. T. Adel

1999-01-01

74

Advanced control system for fine coal flotation.  

National Technical Information Service (NTIS)

A model-based flotation control scheme has been 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...

G. T. Adel G. H. Luttrell

1999-01-01

75

Predicting flotation efficiency using neural networks  

Microsoft Academic Search

This paper presents a model of flotation stage using a neural network to predict the efficiency and the effect of operational parameters on the efficiency of ink removing. Two methods are used to determine the kinetic parameters of the flotation process using particular experimental conditions: experimental data obtained at a laboratory level, and simulated data by means of a neural

J. Labidi; M. À. Pèlach; X. Turon; P. Mutjé

2007-01-01

76

A conceptual model for gold flotation  

Microsoft Academic Search

This paper is aimed at producing a conceptual model for gold flotation based on the discussion of a number of experimental results where the behaviour of free and refractory gold has been studied under different chemical and physical conditions. A review of the literature suggests that there have been numerous studies on the flotation of free gold particles and refractory

A. J. Teague; J. S. J. Van Deventer; C. Swaminathan

1999-01-01

77

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

78

Jurassic Reef Park  

NSDL National Science Digital Library

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

Leinfelder, Reinhold

79

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

Bryson, Linda

2010-01-01

80

Subsurface Onondaga reefs  

Microsoft Academic Search

Seven subsurface Onondaga reefs have been found in southwestern New York (6) and northwestern Pennsylvania (1). These reefs have had a maximum thickness of about 200 feet and cover an area of a few hundred acres. They are similar to nearly 30 smaller reefs in the same geologic section which have previously been found along the Onodaga outcrop. The discovery

Van Tyne

1995-01-01

81

Great Barrier Reef  

NSDL National Science Digital Library

This Landsat-7 color composite image shows a section of the famous Great Barrier Reef, the world's largest living organism. This view displays the southern end of the reef where it is composed of smaller, individual reef structures as opposed to a continuous bank as in the north.

Nasa; Day, Earth S.

82

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.

83

Advances in process control. [Computerized control of coal and ore processing systems  

SciTech Connect

This paper reviews the Opticus IPC (Intelligent Process Control) system which is used to fully automate thickener and/or flotation/filtration units. It discusses both the software and hardware aspects of this system and how the system actually performs in a processing plant environment. The system also has monitoring capabilities to maintain records of chemical additives and general operation of the separation equipment. The paper applies to both coal and ore processing facilities.

Not Available

1993-06-01

84

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

85

Mineral processing and extraction of rare earth elements from the Wadi Khamal Nelsonite Ore, Northwestern Saudi Arabia  

Microsoft Academic Search

A technological sample (50 kg) from Wadi Khamal Nelsonite ore was subjected to magnetic and flotation concentration techniques.\\u000a Excellent recovery percentages of 72.95% and 71.22% were achieved by the dry\\/wet magnetic and flotation concentration techniques,\\u000a respectively. The weight of the apatite concentrate reached a reasonable percentage of approximately 23.5% with an overall\\u000a 40.23% P2O5 total content. Analytical data of the apatite

Hesham M. Harbi; Abdelmonem A. Eldougdoug; M. S. El-Shahawi

2011-01-01

86

Concentracao do minerio de terras raras de Pocos de Caldas-MG. (Concentration of rare earths ore from Pocos de Caldas - MG, Brazil).  

National Technical Information Service (NTIS)

The objective of this research was to concentrate, mainly by flotation, a rare-earth ore body. The valuable mineral is bastnaesite which occurs intimately associated with iron oxides and other gangue minerals, making difficult to get a concentrate of comm...

J. A. Sampaio F. F. Lins N. H. Porphirio

1990-01-01

87

Studies on impeller type, impeller speed and air flow rate in an industrial scale flotation cell. Part 5: validation of k-S b relationship and effect of froth depth  

Microsoft Academic Search

A previous investigation carried out by the authors at the Hellyer concentrator, using a 3 m3 cell fitted with four different impellers treating plant zinc cleaner feed ore, suggested a linear correlation between flotation rate constant k and bubble surface area flux Sb. The relationship between k and Sb was found to be independent of impeller type. This paper describes

B. K. Gorain; T. J. Napier-Munn; J.-P. Franzidis; E. V. Manlapig

1998-01-01

88

21 CFR 890.3175 - Flotation cushion.  

Code of Federal Regulations, 2013 CFR

...with water, air, gel, mud, or any other substance allowing a flotation media, used on a seat to lessen the likelihood of skin ulcers. (b) Classification. Class I (general controls). The device is exempt from the premarket notification...

2013-04-01

89

Alternative Water Treatment Systems Using Flotation Technology.  

National Technical Information Service (NTIS)

Feasibility study was conducted for a parallel comparison between conventional water treatment system and innovative flotation system (KROFTA SANDFLOAT). It was concluded that the innovative system is technically feasible for removal of turbidity, color, ...

M. Krofta L. K. Wang

1982-01-01

90

Artificial Coral Reefs  

NSDL National Science Digital Library

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

Sohmer, Rachel.

91

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

92

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

93

Leaching Gold and Silver Ores.  

National Technical Information Service (NTIS)

Percolation leaching of gold or silver ores is accomplished by means of a process comprising initial pretreatment of the ore with a strong cyanide solution, followed by leaching with water to recover gold or silver values.

H. J. Heinen G. E. McClelland R. E. Lindstrom

1979-01-01

94

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

95

O-Ring Insertion Tool.  

National Technical Information Service (NTIS)

The instant invention relates to electrical connectors and more particularly to a tool for accurately and effectively installing an O-ring in an inwardly facing O-ring groove in an electrical connector without causing damage to the O-ring. While it has ge...

F. Zannini

1990-01-01

96

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

2008-02-23

97

Subsurface Onondaga reefs  

SciTech Connect

Seven subsurface Onondaga reefs have been found in southwestern New York (6) and northwestern Pennsylvania (1). These reefs have had a maximum thickness of about 200 feet and cover an area of a few hundred acres. They are similar to nearly 30 smaller reefs in the same geologic section which have previously been found along the Onodaga outcrop. The discovery well for Onodaga reef gas, although not recognized as such at the time, was the No. 1 Quinlan Oil. The well was drilled in 1933 in the Town of Olean, Cattaraugus County, New York near the New York-Pennsylvania State line. The first of the more recent Onondaga reef discoveries occurred in 1967 at Wyckoff in the Town of Jasper, Steuben County, New York. This discovery touched off a leasing and seismic exploration boom in this area of New York. As a result of these studies, two more reefs were discovered in 1971, two in 1974 and the last so far in 1981. These seven reefs have produced 7.1 billion cubic feet of gas. The smallest, Flatstone, has production to data of about 700 million cubic feet. The Onondaga reefs are of basal Onondaga, or Edgecliff, age. The Edgecliff is a light gray, coarsely crystalline, biostromal limestone. Onondaga reefs may have begun forming on somewhat higher parts of the sea floor in crinoid thickets. Because the Onondaga is considerably thicker in that area these so-called {open_quotes}reefs{close_quotes} are buried entirely within the total Onondaga section. They have been called reefs mainly because gas shows have been encountered in the lower Onondaga when it was drilled through by wells aiming for deeper Medina sandstones gas production. Nevertheless, gas production from them has been minimal. The seal consists of surrounding and overlapping black and gray middle Devonian Hamilton shales. The basal portions are surrounded by onlapping upper Onondaga limestones. The source of the gas is believed to be the highly organic Hamilton shale.

Van Tyne, A.M. [Van Tyne Consulting, Wellsville, NY (United States)

1995-09-01

98

Electrophysical Considerations of the Activation of Sphalerite for Flotation.  

National Technical Information Service (NTIS)

The literature on the activation of sphalerite for flotation by short chain xanthates leaves unanswered the question of whether a compact surface film of activator sulfide is necessary or merely sufficient for high flotation recoveries. Using the theory o...

E. E. Maust P. E. Richardson

1976-01-01

99

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

100

21 CFR 890.5170 - Powered flotation therapy bed.  

Code of Federal Regulations, 2013 CFR

... false Powered flotation therapy bed. 890.5170 Section...CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Therapeutic Devices § 890.5170 Powered flotation therapy bed. (a)...

2013-04-01

101

Investigation of the Performance of Personal Flotation Devices.  

National Technical Information Service (NTIS)

An experimental investigation was performed to study various aspects of an existing theory for flotation equilibrium angle of a person wearing a personal flotation device (PFD) in water. The major objectives were determination of the validity of the theor...

1975-01-01

102

33 CFR 183.112 - Flotation material and air chambers.  

Code of Federal Regulations, 2013 CFR

...COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Flotation Requirements for Inboard Boats, Inboard/Outdrive Boats, and Airboats § 183.112 Flotation material and air...

2013-07-01

103

33 CFR 183.222 - Flotation material and air chambers.  

Code of Federal Regulations, 2013 CFR

...Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Flotation Requirements for Outboard Boats Rated for Engines of More Than 2 Horsepower General § 183.222 Flotation...

2013-07-01

104

33 CFR 183.105 - Quantity of flotation required.  

Code of Federal Regulations, 2013 CFR

...COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Flotation Requirements for Inboard Boats, Inboard/Outdrive Boats, and Airboats § 183.105 Quantity of flotation required....

2013-07-01

105

Application of computer simulation to plant scale fine coal flotation  

SciTech Connect

Improvements in fine (28x0) and ultrafine (200x0) coal cleaning is an acknowledged goal with potential benefits in both steam and metallurgical coal markets. This work focuses on adaptation to fine coal flotation of FLOTE, a computer simulation model of the froth flotation process originally developed in the hard minerals field. FLOTE describes the flotation of solids based on particle surface activity, composition, and size. The quasi steady state model was applied to predict flotation performanc

Toberman, C.J.; Fitz Patrick, J.A.

1984-02-01

106

Coral reefs at risk  

NASA Astrophysics Data System (ADS)

Eighty-eight percent of Southeast Asia's reefs are threatened by overfishing, destructive fishing, and sedimentation and pollution from inland activities, according to a new report by 35 regional scientists published by the World Resources Institute.Nearly 100,000 square kilometers of coral reefs—34% of the world's total—are located in Southeast Asia.

Showstack, Randy

107

46 CFR 25.25-13 - Personal flotation device lights.  

Code of Federal Regulations, 2012 CFR

...2012-10-01 false Personal flotation device lights. 25.25-13 Section 25.25-13...25-13 Personal flotation device lights. (a) This section applies to vessels...vest must have a personal flotation device light that is approved under subpart...

2012-10-01

108

46 CFR 25.25-13 - Personal flotation device lights.  

Code of Federal Regulations, 2011 CFR

...2011-10-01 false Personal flotation device lights. 25.25-13 Section 25.25-13...25-13 Personal flotation device lights. (a) This section applies to vessels...vest must have a personal flotation device light that is approved under subpart...

2011-10-01

109

Froth flotation for fine-coal cleaning. Final report  

SciTech Connect

Froth flotation of fine coal was investigated with the objectives of improving flotation at existing coal-cleaning plants and providing design guidance for future plants. Using hydrodynamically scaled-down laboratory and pilot flotation cells, and the Klimpel flotation model, a methodology was developed to relate laboratory-scale flotation results to full-scale flotation circuits. Froth Factor, the percent of froth over the froth lip, was determined to be the key element of this scale-up methodology. Results showed that simple, inexpensive changes in flotation parameters such as air rate and reagent dosages can significantly improve full-scale flotation product recovery and grade, and that more complex flotation circuitry can produce better recovery levels of high-grade coal than more commonly used rougher-only flotation circuits. In particular, cleaning rougher product can effectively reduce pyritic sulfur content. Results also demonstrated interaction between different size fractions of coal. Flotation rates were shown to depend on feed size consist, and it was found that separations based on differences in flotation rates are more advantageously performed on fine topsizes. Ultimate recoveries appear unaffected by size consist. 6 refs.

Olson, T.J.

1985-12-01

110

Physically absorbable reagents-collectors in elementary flotation  

SciTech Connect

Based on the reviewed researches held at the Institute of Mining, Siberian Branch, Russian Academy of Sciences, the effect of physically absorbable reagents-collectors on formation of a flotation complex and its stability in turbulent pulp flows in flotation machines of basic types is considered. The basic requirements for physically absorbable reagents-collectors at different flotation stages are established.

S.A. Kondrat'ev; I.G. Bochkarev [Russian Academy of Sciences, Novosibirsk (Russian Federation). Institute of Mining

2007-09-15

111

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

112

Gold ores related to shear zones, West Santa Comba-Fervenza Area (Galicia, NW Spain): A mineralogical study  

NASA Astrophysics Data System (ADS)

Recent research has discovered high-grade Au ores in NNE-SSW trending shear zones in metamorphic proterozoic and palaeozoic terranes, some 40 km NW of Santiago de Compostela (NW Spain). The orebodies are bound to late-stage Hercynian structures, mainly due to brittle deformation, which are superimposed on earlier ductile shear zones, cutting through various catazonal lithologies, including ortho- and paragneisses, amphibolites, eclogites, and granites. Ore mineralogy, alteration, and ore textures define a frame whose main features are common to all prospects in the area. Main minerals are arsenopyrite and pyrite — accompanied by quartz, adularia, sericite, ± (tourmaline, chlorite, carbonates, graphite), as main gangue minerals -with subordinate amounts of boulangerite, bismuthinite, kobellite, jamesonite, chalcopyrite, marcasite, galena, sphalerite, rutile, titanite, scheelite, beryl, fluorite, and minor native gold, electrum, native bismuth, fahlore, pyrrhotite, mackinawite, etc., defining a meso-catathermal paragenesis. Detailed microscopic study allows the author to propose a general descriptive scheme of textural classification for this type of ore. Most of the ores fill open spaces or veins, seal cracks or cement breccias; disseminated ores with replacement features related to alteration (mainly silicification, sericitization, and adularization) are also observed. Intensive and repeated cataclasis is a common feature of many ores, suggesting successive events of brittle deformation, hydrothermal flow, and ore precipitation. Gold may be transported and accumulated in any of these events, but tends to be concentrated in later ones. The origin of the gold ores is explained in terms of hydrothermal discharge, associated with mainly brittle deformation and possibly related to granitic magmas, in the global tectonic frame of crustal evolution of West Galicia. The mineralogical and textural study suggests some criteria which will be of practical value for exploration and for ore processing. Ore grades can be improved by flotation of arsenopyrite. Non-conventional methods, such as pressure or bacterial leaching, may subsequently obtain a residue enriched in gold.

Castroviejo, R.

1990-12-01

113

Possible lunar ores  

NASA Astrophysics Data System (ADS)

Despite the conventional wisdom that there are no lunar ores, geochemical considerations suggest that local concentrations of useful rare elements exist on the Moon in spite of its extreme dryness. The Moon underwent protracted igneous activity in its history, and certain magmatic processes can concentrate incompatible elements even if anhydrous. Such processes include: (1) separation of a magma into immiscible liquid phases (depending on composition, these could be silicate-silicate, silicate-oxide, silicate-sulfide, or silicate-salt); (2) cumulate deposits in layered igneous intrusions; and (3) concentrations of rare, refractory, lithophile elements (e.g., Be, Li, Zr) in highly differentiated, silica-rich magmas, as in the lunar granites. Terrestrial mining experience indicates that the single most important characteristic of a potential ore is its concentration of the desire element. The utility of a planet as a resource base is that the welter of interacting processes over geologic time can concentrate rare element automatically. This advantage is squandered if adequate exploration for ores is not first carried out.

Gillett, Stephen L.

114

Nonpolar aromatized reagent for coal flotation  

SciTech Connect

Further improvements in flotation technique and techology are necessitated by the widening application of flotation to coals at the extremes of the rank series, with poor flotation properties, the increasing proportions of fine to very fine size fractions and the more stringent requirements on the quality of washery products. New collecting agents have been developed; they differ fundamentally from the kerosenes and reagent AF-2 used hitherto, in both chemical composition and method of production. The new agents are no longer by-products; they are made as goal products in the petroleum refineries. They consist predominantly of aromatic hydrocarbons with maximum flotation activity; the activity of reagents increases in the order paraffins ..-->.. naphthenes ..-->.. aromatics. In contrast to the linear chains in paraffins and the nonplanar (3-dimensional) rings in naphthenes, the benzene ring has a coplanar structure: the carbon and hydrogen atoms lie in a single plane, while the ..pi..-electron clouds of the carbon atoms lie at right angles to the ring plane and parallel to each other. This structure makes aromatic hydrocarbons superior with respect to adsorption bonding between the molecules of collecting agent and the coal particle surfaces; they most closely match the properties of coals, since the basic structural unit in the latter is a polycyclic aromatic nucleus. The new nonpolar aromatized reagent AAR-2 corresponds to these requirements and has been proposed for commercial use. AAR-2 has a high flotation activity, selectivity and stability, which reduces the costs of flotation. AAR-2 is made by the catalytic cracking of petroleum vacuum distillates on an aluminum silicate catalyst.

Kotkin, A.M.; Rozhnova, E.E.; Vas'ko, I.P.

1981-01-01

115

Life on the Reef  

NSDL National Science Digital Library

This Discovery Channel feature is a live expedition with the American Museum of Natural History. Marine biologists studying the barrier reefs in the Bahamas provide information on scavenger sea worms, brain coral, shell-less nudibranches, sea turtles and sharks, and many other ocean creatures. The scientists also track the various species of the reef using NASA images from space. Photographs and descriptions of the animals and plants off Andros Island are categorized into lagoon, reef, and shelf organisms. Descriptions of the marine biologists working in the Bahamas, and their research interests are provided.

116

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 (CAM I). These methods, tested in the CAMI survival tank and a theme park wave pool, were: (1) two people facing each other, ...

G. E. Funkhouser M. H. George

1995-01-01

117

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

118

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

119

Lead removal with adsorbing colloid flotation  

Microsoft Academic Search

A process that removes lead from industrial waste by adsorbing colloid foam flotation has been designed and demonstrated. A system of ferric chloride and sodium lauryl sulfate, both relatively inexpensive chemicals, gave good performance with optimum dosages of sodium lauryl sulfate at 40 mg\\/l and trivalent iron at 150 mg\\/l. With optimum chemical and hydraulic conditions, the pilot plant was

E. L. Thackston; D. J. Wilson; J. S. Hanson; D. L. Jr. Miller

1980-01-01

120

A New Hybrid Flotation—Microfiltration Cell  

Microsoft Academic Search

The investigated hybrid cell combines the advantages of both flotation and membrane separation, while overcoming their limitations and having as an outcome clean water from a industrial wastewater. Hence, metals recovery from dilute aqueous solutions was a promising application of this innovative process, further to solid\\/liquid separation. The specific objective was to apply the process for the efficient separation of

Efrosyni N. Peleka; Nick K. Lazaridis; Paul Mavros; Kostas A. Matis

2006-01-01

121

Coral reefs in crisis.  

PubMed

This article reports on the crisis facing reefs throughout the world and the struggle to save them. Coral reefs, one of the biological wonders of the world, are among the largest and oldest living communities of plants and animals on earth, having been evolved between 200 and 450 million years ago. Located mostly in the Pacific region, most established coral reefs are now dead and only the upper layer is covered by a thin changeable skin of living coral. Reefs, over the years, have been the main source of animal protein for over 1 billion people in Asia. Countries near the coastlines, which relied on the seas, have resorted to dynamite fishing, poisoning and other illegal and dangerous techniques. Overpopulation and pollution has caused the deteriorating conditions of the 600,000 sq. km of coral reefs worldwide. Despite these conditions, the government has ignored this problem as they struggle to develop their economies at the expense of common resources. In addition, this article narrates the efforts that are exerted by governments in promoting coral reef protection and management of these coastal resources, setting the Apo Island in the Philippines as an example of good management and sustainability. PMID:12295817

Hinrichsen, D

1997-01-01

122

Coral Reef Ecosystems  

NASA Astrophysics Data System (ADS)

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

Yap, Helen T.

123

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

124

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

NASA Astrophysics Data System (ADS)

The Darwinian progressive subsidence model for the evolution of fringing reefs, barrier reefs and atolls has been generally accepted following the indisputable proof of subsidence provided by drilling results in the Pacific. Nonetheless, there are data that do not fit the expectations of the model, such as the similar lagoon depths of barrier reefs and atolls as opposed to the subsidence theory’s implicit prediction that atolls should have significantly greater depths. In contrast, a great deal of evidence supports the influence of meteoric solution on barrier reef morphology. For example, the maximum lagoon depth of 56 modern barrier reefs is statistically correlated with the lagoon catchment area for modern annual rainfall. These modern rainfall patterns would seem to be a reasonable proxy for relative geographic differences in glacial lowstand rainfall, even though the absolute amounts of such rainfall are unknown. The correlation therefore suggests the importance of Pleistocene subaerial solution in contributing to barrier reef morphology. Further support for antecedent influence occurs in the form of barrier reef passes in which the depth of the reef pass is correlated with onshore drainage volumes. On a larger scale, the Cook Island of Mangaia provides evidence that solution can produce barrier reef morphology independent of reef development. In contrast, there are no examples of the subsidence-predicted lagoon transition of fringing reefs to barrier reefs to atolls. Moreover, the common occurrence of fringing reefs within barrier reefs negates subsidence as a causal factor in their ‘presumed progressive evolutionary development. Consequently, the evidence to date suggests that a solution morphology template has been accentuated by reef construction to produce the diagnostic barrier reef morphology we see today. The importance of subsidence would seem to be in accounting for the overall thickness of the resulting carbonate caps of oceanic examples and in contributing to lagoon depth variation among the larger continental entities.

Purdy, Edward G.; Winterer, Edward L.

2006-02-01

125

Can I Trust ORE Reports?  

ERIC Educational Resources Information Center

|This issue of FEEDBACK, a newsletter produced by the the Austin Independent School District Office of Research and Evaluation (ORE), illustrates the accuracy, validity, and fairness of ORE reports. The independence of the reports is explained. Internal and external quality controls are used to ensure reliability and accuracy of the reports.…

Feedback, 1984

1984-01-01

126

O-ring insertion tool  

Microsoft Academic Search

A tool for installing an O-ring in an inwardly facing O-ring groove in an electrical connection includes a guide shaft and a contact member slidably and rotatably received in the guide shaft. The guide shaft includes an elongated cylindrical shaft portion and a flared end portion on the shaft portion. The contact member includes an attachment portion for slidably and

Frank Zannini

1991-01-01

127

High Latitude Reefs: A Potential Refuge for Reef Builders  

Microsoft Academic Search

Coral reefs globally show variable signs of deterioration or community structure changes due to a host of anthropogenic and natural factors. In these global scenarios, rates of calcification by reef builders such as Scleractinian corals are predicted to significantly decline in the future due to the increase in atmospheric CO_2. When considering the response of reefs to the present climate

A. Amat; N. Bates

2003-01-01

128

O-ring insertion tool  

NASA Astrophysics Data System (ADS)

A tool for installing an O-ring in an inwardly facing O-ring groove in an electrical connection includes a guide shaft and a contact member slidably and rotatably received in the guide shaft. The guide shaft includes an elongated cylindrical shaft portion and a flared end portion on the shaft portion. The contact member includes an attachment portion for slidably and rotatably securing the contact member on the shaft portion and a contact finger on the attachment portion which extends in a direction toward the flared end portion of the guide shaft. The tool is operable by assembling an O-ring on the shaft portion between the flared end portion and the contact finger, inserting the flared end portion into a connection and then manipulating the contact member to advance the O-ring into an O-ring groove in the connector with the contact finger.

Zannini, Frank

1991-09-01

129

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

130

Taphonomy of Reefs Through Time  

Microsoft Academic Search

\\u000a Reefs are susceptible to multiple physical, chemical and biological taphonomic processes. Bioerosion, in particular has escalated\\u000a through time and might be expected to have influenced the taphonomy of reefs. The following biases can be predicted: (1) In\\u000a the absence of grain-reducing activities by reef biota (fish, echinoids, and clionid sponges) abrasion on Paleozoic reefs\\u000a would have been dominated by physical

Rachel Wood

131

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

132

Reefs at risk.  

PubMed

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

Hinrichsen, D

1999-01-01

133

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

2012-07-16

134

Improved algal harvesting using suspended air flotation.  

PubMed

Current methods to remove algae from a liquid medium are energy intensive and expensive. This study characterized algae contained within a wastewater oxidation pond and sought to identify a more efficient harvesting technique. Analysis of oxidation pond wastewater revealed that algae, consisting primarily of Chlorella and Scenedesmus, composed approximately 80% of the solids inventory during the study period. Results demonstrated that suspended air flotation (SAF) could harvest algae with a lower air:solids (A/S) ratio, lower energy requirements, and higher loading rates compared to dissolved air flotation (DAF) (P < 0.001). Identification of a more efficient algal harvesting system may benefit wastewater treatment plants by enabling cost effective means to reduce solids content of the final effluent. Furthermore, use of SAF to harvest commercially grown Chlorella and Scenedesmus may reduce manufacturing costs of algal-based products such as fuel, fertilizer, and fish food. PMID:19691251

Wiley, Patrick E; Brenneman, Kristine J; Jacobson, Arne E

2009-07-01

135

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

136

Flotation machine and process for removing impurities from coals  

DOEpatents

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

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

1997-02-11

137

Flotation machine and process for removing impurities from coals  

DOEpatents

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

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

1995-01-01

138

Flotation machine and process for removing impurities from coals  

DOEpatents

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

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

1997-01-01

139

Sphalerite activation: Flotation and electrokinetic studies  

Microsoft Academic Search

Sphalerite is commonly floated in an alkaline environment and under such conditions the overall activation mechanism is obscured by the hydrolysis of Cu2+ and precipitation of Cu(OH)2.Electrokinetic and kinetic flotation tests showed that the activation of sphalerite is a two-stage process; the activation products formed on the surface of sphalerite in near neutral and in alkaline solutions in the first

J. S. Laskowski; Q. Liu; Y. Zhan

1997-01-01

140

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

141

Hydrodynamics and scale up in Rushton turbine flotation cells: Part 2. Flotation scale-up for laboratory and pilot cells  

Microsoft Academic Search

A series of flotation experiments was carried out in three Rushton turbine cells of volumes 2.25, 10 and 50 dm3 using hydrophobic quartz particles to determine a set of scale-up criteria that would produce the same size-by-size flotation rate constants. Flotation was performed at a constant Sauter mean bubble diameter over a range of superficial gas velocities and impeller rotational speeds.The

Ray Newell; Stephen Grano

2006-01-01

142

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.

143

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

144

An Advanced Control System for Fine Coal Flotation. Sixth quarter, technical progress report, July 1-September 30, 1997  

SciTech Connect

Over the past thirty years, process control has spread from the chemical industry into the fields of mineral and coal processing. Today, process control computers, combined with improved instrumentation, are capable of effective control in many modem flotation circuits. Unfortunately, the classical methods used in most control strategies have severe limitations when used in froth flotation. For example, the nonlinear nature of the flotation process can cause single-input, single-output lines to battle each other in attempts to achieve a given objective. Other problems experienced in classical control schemes include noisy signals from sensors and the inability to measure certain process variables. For example, factors related to ore type or water chemistry, such as liberation, froth stability, and floatability, cannot be measured by conventional means. The purpose of this project is to demonstrate an advanced control system for fine coal flotation. The demonstration is being carried out at an existing coal preparation plant by a team consisting of Virginia Polytechnic Institute and State University (VPI&SU) as the prime contractor and J.A. Herbst and Associates as a subcontractor. The objectives of this work are: (1) to identify through sampling, analysis, and simulation those variables which can be manipulated to maintain grades, recoveries, and throughput rates at levels set by management; (2) to develop and implement a model-based computer control strategy that continuously adjusts those variables to maximize revenue subject to various metallurgical, economic, and environmental constraints; and (3) to employ a video-based optical analyzer for on-line analysis of ash content in fine coal slurries.

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

1997-10-27

145

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

NASA Astrophysics Data System (ADS)

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

Gong, Jihua

146

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...

147

Upper Permian Capitan Reef  

Microsoft Academic Search

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.

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

1988-01-01

148

Frothless ion flotation of some rare earth elements  

Microsoft Academic Search

Investigations on frothless ion flotation of europium, thulium, and ; ytterbium in the form of microcolloidal hydroxides from aqueous ammonium chloride ; solutions, and also in the form of anionic complexes with citric acid, as a ; function of flotation time, hydrogen ions, NHâCl, and citric acid ; concentrations were carried out. Anionic and cationic detergents sodium ; tetradecyl sulphate

Z. Szeglowski; M. Bitner-Jankowska; J. Mikulski

1973-01-01

149

Effect of iron content in sphalerite on flotation  

Microsoft Academic Search

The effect of iron, substituted in the mineral lattice, on the froth flotation of sphalerite has been investigated at alkaline pH. It has been found that a critical copper sulphate concentration exists where sphalerite recovery is maximized, above which the recovery of sphalerite then decreases. The presence of iron in sphalerite is detrimental to the rate of sphalerite flotation and

A. Boulton; D. Fornasiero; J. Ralston

2005-01-01

150

Modification of Pyrite and Sphalerite Flotation by Dextrin  

Microsoft Academic Search

The role of dextrin in the xanthate flotation of pyrite and sphalerite was examined by means of flotation tests and microelectrophoretic measurements. Floatability and ?-potential of both minerals were found to be depressed in a suitable pH range due to the formation of their respective superficial metal hydroxide layers. The influences of surface oxidation and flocculation of mineral particles were

K. A. Kydros; G. P. Gallios; K. A. Matis

1994-01-01

151

Froth zone modelling of an industrial flotation column  

Microsoft Academic Search

The mineral recovery in a flotation column is the result of the combined effect of two distinct zones: the collection zone, which acts like a first cleaning stage and the froth zone that allows for a secondary cleaning of the minerals entering the froth.In this paper an experimental study of the froth zone behaviour in an industrial flotation column, is

J. B. Yianatos; L. G. Bergh; G. A. Cortés

1998-01-01

152

Froth flotation: kinetic models based on chemical analogy  

Microsoft Academic Search

This paper studies several kinetic aspects of flotation of celestite and calcite in a mechanical cell with sodium dodecylsulphate as the collector agent, using pure minerals ranging in average particle size between 137 and 74 ?m, respectively, with a constant pH 3 in the flotation bath in all experiments. The results obtained indicate that both minerals float rapidly and that

F Hernáinz; M Calero

2001-01-01

153

Rapid estimation of floatability components in industrial flotation plants  

Microsoft Academic Search

In the analysis of industrial flotation plant data, it is advantageous to build a reliable computer based flotation model to be used in optimisation and design. A number of models have been proposed by many authors with each model having value depending on the complexity of the situation for which it was developed. Several of these models assume that a

D. J. Alexander; R. D. Morrison

1998-01-01

154

Maximum size of floating particles in different flotation cells  

Microsoft Academic Search

Two flotation models, particle at the liquid–gas interface and particle–bubble aggregate, both based on balance of forces, were used for evaluation of experimental data relating the maximum size of floating particles dmax and their advancing contact angle. It was noticed, by comparing the experimental and model data, that for a given flotation device and material the maximum size of floating

Przemyslaw B. Kowalczuk; Oktay Sahbaz; Jan Drzymala

2011-01-01

155

Kinematic model of bubble motion in a flotation froth  

Microsoft Academic Search

A kinematic model for bubble motion in a flotation froth is proposed. The model describes bubble trajectories in a two-dimensional vertical section of the froth phase of a flotation cell. If the viscosity and permeability of the froth is constant over the field, then the motion of bubbles is irrotational and Laplace's equation can be used to describe the setamline

D. G. Murphy; W. Zimmerman; E. T. Woodburn

1996-01-01

156

The dynamic behaviour of coarse particles in flotation froths  

Microsoft Academic Search

The effects of various physical parameters on the rupture of bubble films in two-phase foams were investigated in order to develop a better understanding of the behaviour of coarse particles in the froth phase of a novel flotation cell. This novel flotation technique is based on the fact that coarse particles, if they are selectively rendered hydrophobic by conditioning, would

J. S. J. van Deventer; W. A. van Dyk; L. Lorenzen; D. Feng

2002-01-01

157

Microbially induced flotation and flocculation of pyrite and sphalerite.  

PubMed

Cells of Paenibacillus polymyxa and their metabolite products were successfully utilized to achieve selective separation of sphalerite from pyrite, through microbially induced flocculation and flotation. Adsorption studies and electrokinetic investigations were carried out to understand the changes in the surface chemistry of bacterial cells and the minerals after mutual interaction. Possible mechanisms in microbially induced flotation and flocculation are outlined. PMID:15261012

Patra, Partha; Natarajan, K A

2004-07-15

158

Parameters influencing flotation in removal of metal ions  

Microsoft Academic Search

In this paper the main parameters affecting the flotation process, like reagents (collector, frother, flocculant, etc.) and feed concentrations, pH value of the solution, ionic strength, gas flowrate and bubbles size, as applied to the separation of heavy metals and from dilute aqueous solutions, hydro?metallurgical or environmental origin, are examined. The flotation methods used, in laboratory scale, were ion, precipitate

A. I. Zouboulis; K. A. Matis; G. A. Stalidis

1990-01-01

159

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

160

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

161

Packed-Bed Column Flotation of Fine Coal. Part I. Laboratory Tests and Flotation Circuit Design  

Microsoft Academic Search

An advanced packed column (or static tube) flotation system developed at Michigan Technological University offers the potential for sharp separation of fine coal particles from mineral matter and can be readily incorporated into practice for efficient coal processing at reduced costs. The essential element of the system is the packed-bed cell design in combination with a controlled dispersion reagent scheme.A

D. C. YANG

1990-01-01

162

Flotation activity and thermodynamic adsorption functions of aromatic hydrocarbons  

SciTech Connect

Apolar reagents, used for the flotation of various minerals, contain a significant amount of aromatic hydrocarbons. In this paper, the authors study the flotation activity and thermodynamic adsorption functions of alkylated and polymethylated benzenes with mono- and diisomeric substituents containing various functional groups in the benzene ring. Aromatic hydrocarbons are used widely for the commercial flotation of graphite. The change in free energy and entropy for the adsorption of hydrocarbons with small surface packing at 363/sup 0/K were calculated from the chromatographic data. Benzene is shown to be a poor reagent for the flotation of graphite. Among other conclusions drawn, alkylation, polymethylation and halogenation of benzene increases the thermo-dynamic adsorption functions and flotation activity.

Chizhevskii, V.B.

1988-03-01

163

Optimisation of operating variables of fine coal flotation using a combination of modified flotation parameters and statistical techniques  

Microsoft Academic Search

Optimisation of flotation parameters using rate models is not a new concept. The kinetic model based on time recovery data, which uses the extra dimension of rate, has been in vogue since time immemorial for scaling up of lab data. Often, interpretation on the performance of a flotation circuit, based only on R? (the ultimate recovery) and ks (the first-order

R Sripriya; P. V. T Rao; B. Roy Choudhury

2003-01-01

164

First-order flotation kinetics models and methods for estimation of the true distribution of flotation rate constants  

Microsoft Academic Search

To improve their versatility, many first-order flotation kinetics models with distributions of flotation rate constants were redefined so that they could all be represented by the same set of three model parameters. As a result, the width of the distribution become independent of its mean, and parameters of the model and the curve fitting errors, became virtually the same, independent

M Polat; S Chander

2000-01-01

165

The dependency of the critical contact angle for flotation on particle size – Modelling the limits of fine particle flotation  

Microsoft Academic Search

The flotation behaviour of fine particles is studied in this work. Fine methylated quartz particles within the size range from 0.2 to 50?m, and with varying contact angles, were floated in a mechanical flotation cell. Results indicate that particles of a given size need to possess a minimum critical contact angle, which increases in value as particle size decreases, for

Daniel Chipfunhu; Massimiliano Zanin; Stephen Grano

2011-01-01

166

Investigations of alkylmorpholines––collectors for a new halite flotation process  

Microsoft Academic Search

In recent years the industrial application of a new flotation process has been initiated, namely the reverse flotation of carnallite, the beneficiated carnallite being obtained as a cell product of halite flotation, the latter being carried out with alcylmorpholine as cationic collector. The technology of carnallite reverse flotation has been applied to the industrial processing of the Dead Sea solar

S. Titkov; R. Sabirov; N. Panteleeva

2003-01-01

167

The Effects of Pretreatment on the Flotation Kinetics of Waste Coal  

Microsoft Academic Search

This paper investigates the effect of attrition of fine waste coal from anthracite mine “Vrška ?uka, Serbia on the flotation results and flotation kinetics parameters in a batch flotation cell. Waste coal was generally stored into settling ponds and old tailing ponds as a waste material. Floatability of oxidized coal can be improved by attrition. The flotation tests were performed

Jovica M. Sokolovi?; Rodoljub D. Stanojlovi?; Zoran S. Markovi?

2012-01-01

168

Final report on agglomerate column flotation for cleaning and desulfurization of Ohio coal fines  

Microsoft Academic Search

The objective of this research program was investigate the feasibility of cleaning and desulfurization of Ohio coal by an agglomerate column flotation process, which integrates selective flocculation with conventional column flotation. It was concluded earlier on in the program that the conventional design of flotation column was not particularly efficient for pyrite rejection. A novel design for flotation column system

Y. A. Attia; M. El Zeky; Mulong Yu

1990-01-01

169

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

NASA Astrophysics Data System (ADS)

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

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

2013-03-01

170

Development of the MC3462A pyrotechnic - propellant actuated reefing line cutter  

SciTech Connect

A pyrotechnic-propellant actuated reefing line cutter was developed to sever a 60 kN loaded Kevlar parachute reefing line cord. Dereefing occurs after a time interval of approximately 0.875 second which is provided by an electronic timer module that is an integral part of the cutter. Other design features include a hermetically sealed actuator which is threaded and O-ring sealed into the body, a stainless steel solid cylindrical cutter blade having an attached elastomer obturator that provides a reliable dynamic gas seal throughout the blade stroke and teflon inserts having a semi-circular configuration which are used to center and shroud the reefing line of the design. Variation in the average function time for the cutter is less than 4% at temperature extremes of -55/sup 0/C and 80/sup 0/C. Average depth of penetration of the blade into the aluminum anvil of the cutter is 2 mm.

Craig, J.R.

1982-06-01

171

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.

172

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

173

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

174

The Paleoecology of Coral Reefs  

Microsoft Academic Search

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

John M. Pandolfi

175

THE ECOLOGICAL EVOLUTION OF REEFS  

Microsoft Academic Search

Many groups of extinct and extant organisms have aggregated to form reefs for over 3.5 billion yr (Ga). Most of these communities, however, grew under eco- logical and environmental controls profoundly different from those that govern modern coral reefs. Not only has the global distribution of reefs varied consid- erably through geological time—determined largely by sea level, and latitudinal temperature\\/saturation

Rachel Wood

1998-01-01

176

Digital reef rugosity estimates coral reef habitat complexity.  

PubMed

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

Dustan, Phillip; Doherty, Orla; Pardede, Shinta

2013-02-21

177

Modeling and optimization of flotation processes for coal precleaning  

SciTech Connect

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 modeling has been limited to mass balance based on a kinetic analogy, with a rate constant of collection than can be expressed in terms of probability or efficiency of collection. The present formulation includes the momentum equations in which velocities of phases are explicitly accounted for as dependent variables. It is applicable to both conventional froth flotation and column flotation. A set of multiphase conservative equations for the flotation process has been developed and presented to demonstrate our approach toward computer modeling, taking into account primary interactions of phases. Transport properties associated with these conservation equations are now expressed in terms of probability or efficiency of collection with the identification of generation rates, time constants for momentum transfer, diffusivities, and apparent viscosities. Terms involving interfacial chemistry of the particles and gas bubbles in a liquid suspension and other basic physical phenomena have been grouped into these transport properties. The need remains for accurate determination of the transport parameters with pertinent experimental data concomitant with the volume-averaged formulation of the equations of conservation for flotation processed. A preliminary comparison of the present model with available results was made through a one- dimensional example, namely, approximate solutions for a specific system (CQDC) have been generated from our formulation. 68 refs., 17 figs,. 4 tabs.

Sha, W.T. (Argonne National Lab., IL (USA)); Soo, S.L. (Illinois Univ., Urbana, IL (USA))

1990-09-01

178

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

Microsoft Academic Search

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

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

2008-01-01

179

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

Microsoft Academic Search

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

Baruch Rinkevich

2008-01-01

180

Black reefs: iron-induced phase shifts on coral reefs.  

PubMed

The Line Islands are calcium carbonate coral reef platforms located in iron-poor regions of the central Pacific. Natural terrestrial run-off of iron is non-existent and aerial deposition is extremely low. However, a number of ship groundings have occurred on these atolls. The reefs surrounding the shipwreck debris are characterized by high benthic cover of turf algae, macroalgae, cyanobacterial mats and corallimorphs, as well as particulate-laden, cloudy water. These sites also have very low coral and crustose coralline algal cover and are call black reefs because of the dark-colored benthic community and reduced clarity of the overlying water column. Here we use a combination of benthic surveys, chemistry, metagenomics and microcosms to investigate if and how shipwrecks initiate and maintain black reefs. Comparative surveys show that the live coral cover was reduced from 40 to 60% to <10% on black reefs on Millennium, Tabuaeran and Kingman. These three sites are relatively large (>0.75 km(2)). The phase shift occurs rapidly; the Kingman black reef formed within 3 years of the ship grounding. Iron concentrations in algae tissue from the Millennium black reef site were six times higher than in algae collected from reference sites. Metagenomic sequencing of the Millennium Atoll black reef-associated microbial community was enriched in iron-associated virulence genes and known pathogens. Microcosm experiments showed that corals were killed by black reef rubble through microbial activity. Together these results demonstrate that shipwrecks and their associated iron pose significant threats to coral reefs in iron-limited regions. PMID:21881615

Kelly, Linda Wegley; Barott, Katie L; Dinsdale, Elizabeth; Friedlander, Alan M; Nosrat, Bahador; Obura, David; Sala, Enric; Sandin, Stuart A; Smith, Jennifer E; Vermeij, Mark J A; Williams, Gareth J; Willner, Dana; Rohwer, Forest

2011-09-01

181

Adaptive Avoidance of Reef Noise  

Microsoft Academic Search

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

Stephen D. Simpson; Andrew N. Radford; Edward J. Tickle; Mark G. Meekan; Andrew G. Jeffs; A. Peter Klimley

2011-01-01

182

Perspectives in coral reef hydrodynamics  

NASA Astrophysics Data System (ADS)

Some developments in coral reef hydrodynamics over the last decade are reviewed with an overview of papers in this special issue. Advances in hydrodynamics based on improved understanding of topographic complexity are illustrated for the reef at Kilo Nalu Observatory and Kaneohe Bay (both in Hawaii). Models of the roughness layer are discussed as a background to numerical models of reef hydrodynamics for Molokai and Guam. Topographic complexity produces spatial temperature variability over reefs creating thermal microclimates which are reported in this issue for the Red Sea. Uptake of ocean nutrients by reefs is controlled by hydrodynamics, and papers in this issue show its critical role in the ecology of a fringing reef at La Réunion Island; nutrient uptake rates are discussed here using new data for Hearn Roughness and Decadal Rugosity. The role of upwelled water by large amplitude internal waves on reefs is reported for the Similan Islands, providing major new evidence for the role of hydrodynamics in the ecology of reefs and its importance to climate change. The review suggests some important areas for new research including simulated corals used in flumes and the field. Major new modeling based on measured roughness maps combined with small scale lattice Boltzmann simulations should be possible in the next decade.

Hearn, Clifford J.

2011-06-01

183

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

184

Coral reefs and carbon dioxide  

SciTech Connect

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

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

1996-03-01

185

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

186

REEF CORALS : AUTOTROPHS OR HETEROTROPHS?  

Microsoft Academic Search

Some recent studies 2 seem to indicate that the nutritional economy of reef corals is for all practical purposes to be considered autotrophic due to their zooxanthellae (Fig. 1). For example, Franzisket (1969a, 1970) claims to have demonstrated that some Hawaiian reef corals can achieve net growth in the total absence of particulate food, while Johannes and Coles ( 1969)

THOMAS F. GOREAU; NORA I. GOREAU; C. M. YONGE

1971-01-01

187

Biomass of suspended bacteria over coral reefs  

Microsoft Academic Search

The biomass of bacteria suspended in water flowing over coral reefs at Lizard Island and Yonge Reef (Northern Great Barrier Reef) was estimated by measurement of muramic acid. Values ranged from 20 mg C m-3 in the open water up to about 60 mg C m-3 over the reef flat. Direct counts of total numbers of free bacteria were made

D. J. W. Moriarty

1979-01-01

188

Miocene precursors to Great Barrier Reef  

Microsoft Academic Search

Huge reefs of Miocene age are present in the Gulf of Papua north of the present-day Great Barrier Reef and to the east on the Marion and Queensland Plateaus. In the Gulf of Papua, Miocene barrier reefs formed the northern forerunner of the Great Barrier Reef, extending for many hundreds of kilometers along the eastern and northern margin of the

P. J. Davies; P. A. Symonds; D. A. Feary; C. Pigram

1988-01-01

189

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

190

Conical O-ring seal  

SciTech Connect

A shipping container for radioactive or other hazardous materials 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, G.G. Jr.

1984-08-14

191

Gaseous reduction of laterite ores  

NASA Astrophysics Data System (ADS)

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

Utigard, T.; Bergman, R. A.

1993-04-01

192

Endogenic Au-Ag polymetallic ore deposits and ore-bearing potentiality of strata  

Microsoft Academic Search

The problem of ore-bearing potentiality of the strata involves metallogenic theory and ore-search orientation. Studies of\\u000a the spatial distribution of endogenic Au-Ag polymetallic ore deposits in North Hebei indicated that the strata in which ore\\u000a deposits occurred range in age from Paleozoic, Proterozoic to Mesozoic. In addition the ore deposits are characterized as\\u000a being strata-bound in nature. The arise and

Baode Wang; Shuyin Niu; Aiqun Sun; Yan Xie; Yi Luo; Hailong Liu; Yanhua Wang

2010-01-01

193

DISSOLVED AIR FLOTATION TREATMENT OF GULF SHRIMP CANNERY WASTEWATER  

EPA Science Inventory

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

194

Foam Flotation Process for Separating 'Bacillus thuringiensis' Sporulation Products.  

National Technical Information Service (NTIS)

Crystal-enriched suspensions are derived from sporulated cultures of Bacillus thuringiensis by a foam flotation process in which added gelatin causes the spores to be selectively entrained in the foam and thereby separated from the suspensions.

E. S. Sharpe A. I. Herman S. C. Toolan

1979-01-01

195

Transient Modeling of Froth Flotation and Vacuum Filtration Processes.  

National Technical Information Service (NTIS)

Transient models of the froth flotation and vacuum filtration processes as applied to fine-coal beneficiation are presented. The models consist of sets of simultaneous ordinary differential and algebraic equations which were derived based on the principle...

C. H. Brown G. O. Allgood G. S. Canright W. R. Hamel

1981-01-01

196

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

1999-08-01

197

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

198

33 CFR 183.114 - Test of flotation materials.  

Code of Federal Regulations, 2013 CFR

...CONTINUED) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT...Requirements for Inboard Boats, Inboard/Outdrive Boats, and Airboats § 183... (a) Vapor test. The flotation material...c) Engine room unless open to atmosphere...

2013-07-01

199

Evaluation of Flotation Materials Used in Recreational Boats.  

National Technical Information Service (NTIS)

The effects of immersion, friability, freeze-thaw cycling and gasoline vapor on various plastic flotation materials is examined. Fresh water, salt water, bilge cleaner in water, and gasoline were used as immersion liquids. The materials tested included po...

R. C. Richards

1976-01-01

200

Flotation of Phosphorous-Uraniferous Minerals from Itataia.  

National Technical Information Service (NTIS)

Experimental conditions were established, in laboratory and pilot scales, for the flotation of a sample of a phosphorus-uraniferous mineral from Itataia mines (CE, Brazil), basically composed of apatite and calcite. Laboratory investigations led to the op...

J. A. Aquino

1984-01-01

201

33 CFR 183.202 - Flotation and certification requirements.  

Code of Federal Regulations, 2013 CFR

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

2013-07-01

202

33 CFR 183.225 - Flotation test for persons capacity.  

Code of Federal Regulations, 2013 CFR

...SECURITY (CONTINUED) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Flotation Requirements for Outboard Boats Rated for Engines of More Than 2 Horsepower...prescribed in § 183.220 are met, the boat must float in fresh, calm water as...

2013-07-01

203

33 CFR 183.325 - Flotation test for persons capacity.  

Code of Federal Regulations, 2013 CFR

...SECURITY (CONTINUED) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Flotation Requirements for Outboard Boats Rated for Engines of 2 Horsepower or Less...prescribed in § 183.320 are met, the boat must float in fresh, calm water as...

2013-07-01

204

Zircon-rutile-ilmenite froth flotation process  

SciTech Connect

This patent describes a method for separating a mixture of minerals comprising at least zircon, ilmenite and rutile. It comprises adding an acid solution to the mixture to acidify to a pH of between about 2.0 and 6.0; adding starch to the mixture to depress the ilmenite and the rutile; adding a source of fluoride ions to the mixture to provide a negative surface charge on the zircon surface to activate the zircon; adding an amine cationic collector to the mixture to float the activated zircon; subjecting the mixture containing the added acid solution, the fluoride ions, the starch and the cationic collector, to froth flotation; and withdrawing a float product comprising the zircon and a sink product comprising the ilmenite and rutile.

Schmidt, R.; Denham, D.L. Jr.

1992-04-21

205

Multichannel reflectance spectral assaying of zinc and copper flotation slurries  

Microsoft Academic Search

This article extends the earlier work (Haavisto et al. 2008. Optical spectrum based measurement of flotation slurry contents. Int. J. Miner. Process. 88 (3–4), 80–88), where visible and near-infrared (VNIR) reflectance spectroscopy was used together with an X-ray fluorescence (XRF) analyzer to improve the assaying of zinc flotation concentrate. Especially the sampling interval of the assay could be drastically reduced

Olli Haavisto; Jani Kaartinen

2009-01-01

206

AN ADVANCED CONTROL SYSTEM FOR FINE COAL FLOTATION  

Microsoft Academic Search

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

G. H. Luttrell; G. T. Adel

1999-01-01

207

A simple model for the calculation of entrainment in flotation  

Microsoft Academic Search

Theoretical and experimental studies have been performed to analyze the entrainment of both hydrophilic and hydrophobic particles\\u000a in flotation. A new model is proposed for the entrainment based on the water recovery trend. Two sets of timed flotation experiments\\u000a were carried out to validate the model. These experiments were realized with quartz and pyrite as the only mineral in the

Ozcan Y. Gulsoy

2005-01-01

208

Optimisation of a multistage flotation plant using plant survey data  

Microsoft Academic Search

The purpose of the investigation was to develop a procedure for optimisation of complex flotation circuits, using steam assays and pulp densities alone (i.e. no additional measurements or batch tests). Conventional models, based on pulp kinetics, were regressed directly to steady-state data from a nine-stage platinum flotation plant, to provide a basis for optimisation studies. ‘Froth factors’ were obtained by

B. K. Loveday; A. L. Hemphill

2006-01-01

209

Modeling Erosion Wear Rates in Slurry Flotation Cells  

Microsoft Academic Search

In processes using slurry as the working fluid, wear due to solid particles impinging on elements of the process units is\\u000a a serious reliability issue. This study considers modeling wear damage in flotation cells, which are widely used in mineral\\u000a processing. Flotation cells are typically cylindrical vessels where an impeller is used to agitate the fluid, enabling the\\u000a liberation of

M. G. Lipsett; V. Bhushan

210

Kinetics of pyrochlore flotation from Araxá mineral deposits  

Microsoft Academic Search

The niobium mineral deposits in Brazil account for more than 70% of the world's known reserves. Currently flotation of pyrochlore is carried out in the Araxá plant using amines as collector at low pH, in the presence of NaF as an activator and with the addition of a modifier.In the present work bench scale flotation kinetic testwork was conducted, aimed

J. F. Oliveira; S. M. Saraiva; J. S. Pimenta; A. P. A. Oliveira

2001-01-01

211

Risk-based compliance assessment models for personal flotation devices  

Microsoft Academic Search

We present the proposed risk-based compliance assessment models of personal flotation devices. They constitute a suggested approval process of personal flotation devices (PFDs) based on the ability of PFDs to save lives as a result of marine events. Ayyub and Wilcox (2000) initially suggested a risk-based compliance approval methodology for PFDs for the U.S. Coast Guard. The methodology was revised

Bilal M. Ayyub; Khalid Nejaim

2003-01-01

212

Froth-based modeling and control of flotation processes  

Microsoft Academic Search

This paper illustrates a new way for modeling and control of flotation processes based on froth appearances. As shown our previous work [Liu, J., MacGregor, J.F., Duchesne, C., Bartolacci, G., 2005. Monitoring of flotation processes using multiresolutional multivariate image analysis. Minerals Engineering 18 (1), 65–76], scores of the MR-MIA features can be viewed as numerical estimates of froth status or

J. Jay Liu; John F. MacGregor

2008-01-01

213

Particle–bubble interaction and attachment in flotation  

Microsoft Academic Search

Flotation is an important unit operation in the minerals industry, among others. Current state-of-the-art flotation modelling combines computational fluid dynamics (CFD) with user-defined algorithms based on the “induction time” concept to describe selective bubble–particle attachment and separation of hydrophobic and hydrophilic particles.We have undertaken experimental studies permitting direct observation of particle–bubble interaction and attachment at the microscale to provide empirical

David I. Verrelli; Peter T. L. Koh; Anh V. Nguyen

2011-01-01

214

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

215

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

216

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

217

An Advanced Control System For Fine Coal Flotation  

Microsoft Academic Search

A model-based flotation control scheme is being implemented to achieve optimal;\\u000aperformance in the handling and treatment of fine coal. The control scheme monitors flotation;\\u000aperformance through on-line analysis of ash content. Then, based on the economic and;\\u000ametallurgical performance of the circuit, variables such as collector dosage, frother dosage, and;\\u000apulp level are adjusted using model-based control algorithms to

G. H. Luttrell; G. T. Adel

1998-01-01

218

Froth modification for reduced fuel oil usage in phosphate flotation  

Microsoft Academic Search

The Florida phosphate industry uses millions of pounds of fuel oil per year for phosphate flotation. It is of significant environmental and economic benefit to reduce the usage of fuel oil. This paper presents laboratory-testing results from both a FIPR in-house research program and a contractual project with University of Utah. In the FIPR in-house project, three different flotation feed

Robert SnoW; Jinrong “Patrick” Zhang; Jan D. Miller

2004-01-01

219

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

220

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

221

Optimising froth condition and recovery for a nickel ore  

Microsoft Academic Search

By its nature a simple kinetic flotation model is limited because simulation of the flotation process is complex and therefore requires the inclusion of a vast number of variables that affect the flotation system. The majority of these variables are not incorporated into a kinetic model.In an attempt to circumvent this, EMC has for some years been developing an empirically

Martyn P. Hay

2008-01-01

222

Capitol Reef National Park  

NSDL National Science Digital Library

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

223

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

224

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

225

Expeditions in Conservation: Mesoamerican Reef  

NSDL National Science Digital Library

The World Wildlife Fund (WWF) recently completed this expedition of the largest coral reef system in the Atlantic Ocean and has provided an opportunity for Web users to share some of what they experienced. Visitors can view spectacular photos and videos to learn about the reef and the creatures that reside there, as well as read the daily reports of the expedition. The site offers much more in terms of learning about coral reefs, the people who study them, and the threats that face these unique ecosystems.

1969-12-31

226

NOAA's hydrolab conducts reef studies  

NASA Astrophysics Data System (ADS)

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

227

Electrostatic beneficiation of gold ores  

Microsoft Academic Search

The authors present encouraging results obtained in separation of the Doyon gold ores when using the electrostatic inverted roof apparatus described by I.I. Inculer et al. (ibid., vol.IA-9, no.3, p.318-23, 1983). The electrification phenomena through combined tribo-electric and inductive charging were studied at various relative humidities. Contrary to expectations, the experimental work showed that the best separations are achieved at

I. I. Inculet; G. S. P. Castle; R. M. Quigley; K. J. Hodgson

1988-01-01

228

Ecology of the south Florida coral reefs: a community profile  

SciTech Connect

An overview of coral reef research in southern Florida is provided as a prelude to a genuine description of the coral reef ecosystem in the Florida Keys and surrounding environments. Coral reef community types, reef benthos, plankton and reef fish are given specific treatment. Coral reef ecology and management are described. 27 figs., 31 tabs.

Jaap, W.C.

1984-08-01

229

Fish assemblages on estuarine artificial reefs: natural rocky-reef mimics or discrete assemblages?  

PubMed

If the primary goal of artificial reef construction is the creation of additional reef habitat that is comparable to adjacent natural rocky-reef, then performance should be evaluated using simultaneous comparisons with adjacent natural habitats. Using baited remote underwater video (BRUV) fish assemblages on purpose-built estuarine artificial reefs and adjacent natural rocky-reef and sand-flat were assessed 18 months post-deployment in three south-east Australian estuaries. Fish abundance, species richness and diversity were found to be greater on the artificial reefs than on either naturally occurring reef or sand-flat in all estuaries. Comparisons within each estuary identified significant differences in the species composition between the artificial and natural rocky-reefs. The artificial reef assemblage was dominated by sparid species including Acanthopagrus australis and Rhabdosargus sarba. The preference for a range of habitats by theses sparid species is evident by their detection on sand-flat, natural rocky reef and artificial reef habitats. The fish assemblage identified on the artificial reefs remained distinct from the adjacent rocky-reef, comprising a range of species drawn from naturally occurring rocky-reef and sand-flat. In addition, some mid-water schooling species including Trachurus novaezelandiae and Pseudocaranx georgianus were only identified on the artificial reef community; presumably as result of the reef's isolated location in open-water. We concluded that estuarine artificial reef assemblages are likely to differ significantly from adjacent rocky-reef, potentially as a result of physical factors such as reef isolation, coupled with species specific behavioural traits such as the ability of some species to traverse large sand flats in order to locate reef structure, and feeding preferences. Artificial reefs should not be viewed as direct surrogates for natural reef. The assemblages are likely to remain distinct from naturally occurring habitat comprised of species that reside on a range of adjacent natural habitats. PMID:23755106

Folpp, Heath; Lowry, Michael; Gregson, Marcus; Suthers, Iain M

2013-06-03

230

Fish Assemblages on Estuarine Artificial Reefs: Natural Rocky-Reef Mimics or Discrete Assemblages?  

PubMed Central

If the primary goal of artificial reef construction is the creation of additional reef habitat that is comparable to adjacent natural rocky-reef, then performance should be evaluated using simultaneous comparisons with adjacent natural habitats. Using baited remote underwater video (BRUV) fish assemblages on purpose-built estuarine artificial reefs and adjacent natural rocky-reef and sand-flat were assessed 18 months post-deployment in three south-east Australian estuaries. Fish abundance, species richness and diversity were found to be greater on the artificial reefs than on either naturally occurring reef or sand-flat in all estuaries. Comparisons within each estuary identified significant differences in the species composition between the artificial and natural rocky-reefs. The artificial reef assemblage was dominated by sparid species including Acanthopagrus australis and Rhabdosargus sarba. The preference for a range of habitats by theses sparid species is evident by their detection on sand-flat, natural rocky reef and artificial reef habitats. The fish assemblage identified on the artificial reefs remained distinct from the adjacent rocky-reef, comprising a range of species drawn from naturally occurring rocky-reef and sand-flat. In addition, some mid-water schooling species including Trachurus novaezelandiae and Pseudocaranx georgianus were only identified on the artificial reef community; presumably as result of the reef's isolated location in open-water. We concluded that estuarine artificial reef assemblages are likely to differ significantly from adjacent rocky-reef, potentially as a result of physical factors such as reef isolation, coupled with species specific behavioural traits such as the ability of some species to traverse large sand flats in order to locate reef structure, and feeding preferences. Artificial reefs should not be viewed as direct surrogates for natural reef. The assemblages are likely to remain distinct from naturally occurring habitat comprised of species that reside on a range of adjacent natural habitats.

Folpp, Heath; Lowry, Michael; Gregson, Marcus; Suthers, Iain M.

2013-01-01

231

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

232

Biological destruction of coral reefs  

NASA Astrophysics Data System (ADS)

The major agents of biological destruction of coral reefs can be divided into grazers, etchers and borers. Each of these groups is reviewed on a world wide basis, together with the mechanisms by which they destroy the coral substrate. Rates of bioerosion attributed to major agents of grazers, etchers and borers are given, together with limitations of some of the measurements. Recent work is highlighting the variability in rates of bioerosion both over time and space. Factors which may be responsible for this variability are discussed. Bioerosion is a major factor influencing reef morphology and the ways in which this is achieved is discussed in some detail. Although the review concentrates mainly on present day reefs, some attempt is made to consider the impact of bioerosion on older reefs.

Hutchings, P. A.

1986-05-01

233

Artificial Reefs and Ocean Dumping.  

ERIC Educational Resources Information Center

|Activities and instructional strategies for two multigrade lessons are provided. Activity objectives include describing an artificial reef (such as a sunken ocean liner) as an ecosystem, knowing animal types in the ecosystem, and describing a food web. (JN)|

Glueck, Richard D.

1983-01-01

234

46 CFR 28.110 - Life preservers or other personal flotation devices.  

Code of Federal Regulations, 2010 CFR

...equipped with at least one immersion suit, exposure suit, or wearable personal flotation device of the proper size for each...must meet the requirements of this paragraph. (b) Each wearable personal flotation device must be stowed so that it...

2009-10-01

235

46 CFR 28.110 - Life preservers or other personal flotation devices.  

Code of Federal Regulations, 2010 CFR

...equipped with at least one immersion suit, exposure suit, or wearable personal flotation device of the proper size for each...must meet the requirements of this paragraph. (b) Each wearable personal flotation device must be stowed so that it...

2010-10-01

236

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

237

Reef Bioerosion: Agents and Processes  

Microsoft Academic Search

\\u000a Coral reef maintenance depends on the balance between constructive and destructive forces. Constructive forces are mainly\\u000a calcification and growth of corals and encrusting coralline algae. Destructive forces comprise physical, chemical, and biological\\u000a erosion. Bioerosion is considered as the main force of reef degradation because physical erosion (storms) is temporary and\\u000a localized, and chemical erosion is considered as negligible due to

Aline Tribollet; Stjepko Golubic

238

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.

2011-11-04

239

Coral reef bleaching: ecological perspectives  

NASA Astrophysics Data System (ADS)

Coral reef bleaching, the whitening of diverse invertebrate taxa, results from the loss of symbiotic zooxanthellae and/or a reduction in photosynthetic pigment concentrations in zooxanthellae residing within the gastrodermal tissues of host animals. Of particular concern are the consequences of bleaching of large numbers of reef-building scleractinian corals and hydrocorals. Published records of coral reef bleaching events from 1870 to the present suggest that the frequency (60 major events from 1979 to 1990), scale (co-occurrence in many coral reef regions and often over the bathymetric depth range of corals) and severity (>95% mortality in some areas) of recent bleaching disturbances are unprecedented in the scientific literature. The causes of small scale, isolated bleaching events can often be explained by particular stressors (e.g., temperature, salinity, light, sedimentation, aerial exposure and pollutants), but attempts to explain large scale bleaching events in terms of possible global change (e.g., greenhouse warming, increased UV radiation flux, deteriorating ecosystem health, or some combination of the above) have not been convincing. Attempts to relate the severity and extent of large scale coral reef bleaching events to particular causes have been hampered by a lack of (a) standardized methods to assess bleaching and (b) continuous, long-term data bases of environmental conditions over the periods of interest. An effort must be made to understand the impact of bleaching on the remainder of the reef community and the long-term effects on competition, predation, symbioses, bioerosion and substrate condition, all factors that can influence coral recruitment and reef recovery. If projected rates of sea warming are realized by mid to late AD 2000, i.e. a 2°C increase in high latitude coral seas, the upper thermal tolerance limits of many reef-building corals could be exceeded. Present evidence suggests that many corals would be unable to adapt physiologically or genetically to such marked and rapid temperature increases.

Glynn, P. W.

1993-03-01

240

Study the effect of chromite ore properties on pelletisation process  

Microsoft Academic Search

Chrome ore properties play a critical role in various pelletisation subprocesses (grinding, filtering, pelletisation and sintering) and slight variation in ore properties significantly affect the whole pelletisation process. Three ore samples (sample-A, B and C) were collected from different working faces of a chromite ore mine. Experiments were carried out to find out the difference in grinding (Inherent ore granulometry,

Veerendra Singh; S. Mohan Rao

2008-01-01

241

Evolution of ore deposits on terrestrial planets  

NASA Astrophysics Data System (ADS)

Ore deposits on terrestrial planets materialized after core formation, mantle evolution, crustal development, interactions of surface rocks with the hydrosphere and atmosphere, and, where life exists on a planet, the involvement of biological activity. Core formation removed most of the siderophilic and chalcophilic elements, leaving mantles depleted in many of the strategic and noble metals relative to their chondritic abundances. Basaltic magma derived from partial melting of the mantle transported to the surface several metals contained in immiscible silicate and sulfide melts. Magmatic ore deposits were formed during cooling, fractional crystallization and density stratification from the basaltic melts. Such ore deposits found in earth's Archean rocks were probably generated during early histories of all terrestrial planets and may be the only types of igneous ores on Mars. Where plate tectonic activity was prevalent on a terrestrial planet, temporal evolution of ore deposits took place. Repetitive episodes of subduction modified the chemical compositions of the crust and upper mantles, leading to porphyry copper and molybdenum ores in calc-alkaline igneous rocks and granite-hosted tin and tungsten deposits. Such plate tectonic-induced mineralization in relatively young igneous rocks on earth may also have produced hydrothermal ore deposits on Venus in addition to the massive sulfide and cumulate chromite ores associated with Venusian mafic igneous rock. Sedimentary ore deposits resulting from mechanical and chemical weathering in reducing atmospheres in Archean earth included placer deposits (e.g., uraninite, gold, pyrite ores). Chromite, ilmenite, and other dense unreactive minerals could also be present on channel floors and in valley networks on Mars, while banded iron formations might underlie the Martian northern plains regions. As oxygen evolved in earth's atmosphere, so too did oxide ores. By analogy, gossans above sulfide ores probably occur on Mars, but not submarine ferromanganese nodules and crusts which have precipitated in oxygenated seawater on earth.

Burns, R. G.

242

Application of Odor Sensors to Ore Sorting and Mill Feed Control  

SciTech Connect

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

Michael G. Nelson

2005-08-01

243

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

Microsoft Academic Search

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

A. L. Alldredge; J. M. King

1977-01-01

244

Coral reef development under naturally turbid conditions: fringing reefs near Broad Sound, Australia  

Microsoft Academic Search

Reef coring and NOAA\\/AVHRR imagery were used to examine differences in reef colonisation and accumulation across a gradient of increasing tidal range and turbidity. AVHRR channel-1 reflectance, which was strongly correlated with suspended sediment concentration (SSC), demonstrated that SSC is due to tidal resuspension of sediments, and increases with increasing tidal range. Underwater surveys and reef coring revealed that reef

J. A. Kleypas

1996-01-01

245

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

246

Terrigenous sediments as influences upon Holocene nearshore coral reefs, central Great Barrier Reef, Australia  

Microsoft Academic Search

Sedimentary studies of inner shelf reefs on the Great Barrier Reef shelf increasingly reveal evidence for coral growth in turbid, shallow coastal environments, where coral survival is aided by prevailing hydrodynamic and sedimentological conditions. New models of coral reef growth on the Great Barrier Reef are needed which explicitly include the role of terrigenous sediments in influencing sites of potential

P. Larcombe; K. J. Woolfe

1999-01-01

247

Coral-reef hydrology: field studies of water movement within a barrier reef  

Microsoft Academic Search

Water movement through the framework of Davies Reef, a coral reef in the central Australian Great Barrier Reef, was studied using field and laboratory determinations of permeability, tide gauge measurements of water levels, dye tracers, and pore water chemistry. Flow is driven by current, wind-induced, or tide-induced water level differences which were shown to occur between reef front and lagoon.

J. A. Oberdorfer; R. W. Buddemeier

1986-01-01

248

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

249

A review of methods to model the froth phase in non-steady state flotation systems  

Microsoft Academic Search

The current of batch flotation froth modelling is critically reviewed in order to identify its significance and usefulness, particularly in the scale-up of batch data to a continuous flotation process. This review suggests that the concept of the froth recovery factor, Rf, may provide the most useful way of establishing the performance of the froth phase in a batch flotation

Z. T. Mathe; M. C. Harris; C. T. O'Connor

2000-01-01

250

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

Microsoft Academic Search

The extensive literature on sulfide flotation indicates that pyrite poorly floats under alkaline condition. Xanthate concentration has a positive effect on pyrite flotation, but above a pH of 11, pyrite seems to be strongly depressed, independently of the concentration in xanthate. In this investigation, aeration and xanthate concentration effects were studied for pyrite flotation conditioned at pH 11 with lime.

R Mermillod-Blondin; M Kongolo; P de Donato; M Benzaazoua; O Barrès; B Bussière; M Aubertin

251

Separation of activated sludge from purified waste water by Induced Air Flotation (IAF)  

Microsoft Academic Search

The Induced Air Flotation (IAF) applies a self aspirating and radially discharging funnel-shaped nozzle, which produces extremely fine gas bubbles by using only 10% of the purified waste water recycle as the propulsion jet. This nozzle is installed in a flotation cell, where intimate contact between flocs and gas bubbles takes place. The flotation cell is enclosed by a bigger

Marko Zlokarnik

1998-01-01

252

Removal of Trace Levels off Phenols from Aqueous Solution by Foam Flotation  

Microsoft Academic Search

Peritachlorophenol (PCP) was removed from water by foam flotation with the cationic surfactant cetyltrimethylammonium bromide (CTAB). With initial PCP concentrations of 20 ppm or less, residual PCP concentrations of less than 0.05 ppm were obtained after 5 min flotation. The CTAB concentration and flotation time are directly related to the amount of PCP removed. PCP removal is most efficient at

G. A. Nyssen; G. S. Lovell; A. A. Simon; J. G. Smith; B. K. Tolar; D. J. Wilson

1987-01-01

253

Effect of Coating Components and Fillers in the Flotation Deinking of Paper.  

National Technical Information Service (NTIS)

The aim of this thesis was to investigate how different types of pigments used as fillers and coating pigments behave in flotation deinking process, i.e. how the pigments flotate and possibly affect the flotation process. The theory part reviews shortly t...

J. Heimonen

1995-01-01

254

The influence of cyanide on pyrite flotation from gold leach residues with sodium isobutyl xanthate  

Microsoft Academic Search

Impedance measurements, linear voltammetry, and flotation tests were carried out to determine the influence of NaCN on the flotation of pyrite from gold leach residues. The mixed potential of the pyrite electrode was found to decrease in the presence of NaCN. However, the decrease of the mixed potential does not adequately explain the depression of pyrite flotation, which is the

J. R. de Wet; P. C. Pistorius; R. F. Sandenbergh

1997-01-01

255

Early Development of Pendelton Artificial Reef.  

National Technical Information Service (NTIS)

An artificial reef was constructed of 10,000 tons of quarry rock in Southern California offshore of Camp Pendleton. Management techniques have included transplanting giant kelp to accelerate and direct ecological succession changes on the reef.

A. Grover H. A. Togstad J. J. Grant K. C. Wilson

1982-01-01

256

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

Microsoft Academic Search

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

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

1987-01-01

257

Coral Reef Fishes: Opportunities, Challenges and Concerns  

Microsoft Academic Search

\\u000a Coral reef fishes represent superb models for test of biological theory in field or laboratory. Nonetheless, our knowledge\\u000a comes from few locations, few biological disciplines, and few of the more than 70 families of fishes occupying coral reefs.\\u000a Most reef fishes exhibit complex life histories involving distinctive pelagic larval stages, ecological and structural changes\\u000a associated with settling on reefs, and

W. Linn Montgomery

258

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

259

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

260

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

261

Coral Reefs and Their Management in Tanzania  

Microsoft Academic Search

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

Greg M. Wagner

262

Silurian pinnacle reefs of the Canadian Arctic  

Microsoft Academic Search

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

T. A. De Freitas; O. A. Dixon; U. Mayr

1993-01-01

263

The Pros and Cons of Artificial Reefs  

NSDL National Science Digital Library

This lesson plan asks students to consider whether artificial reefs (human-made objects in the ocean or sea) are good for marine ecosystems. Students will look at pictures of artificial reefs and read articles describing the pros and cons of these structures. They will conclude by writing paragraphs explaining whether they think a new artificial reef should be created in Florida waters.

264

The Biosphere 2 coral reef biome  

Microsoft Academic Search

The Biosphere 2 coral reef biome is a large tank of living coral reef organisms (water volume of 2650 m3, water surface area of 711 m2 and 590 m2 of reef benthos). The water of the biome is characteristically very low in dissolved nutrients and phytoplankton. The present community of organisms is largely comprised of macroalgae, including 11 genera of

M. J. Atkinson; H. Barnett; H. Aceves; C. Langdon; S. J. Carpenter; T. McConnaughey; E. Hochberg; M. Smith; B. D. V. Marino

1999-01-01

265

A mathematical model for the flotation of waste activated sludge.  

PubMed

A mathematical model that describes a batch flotation process is presented. The model employed a similar method to the hindered settling of flocculated material. This idea is based on our experimental results that the time growth curves of separated liquor zone showed a similar character to the settling curve of flocculated material, when the vertical axis reversed. In this model, it is also assumed that the gas phase and solid phase have the same movement, that is microbubbles and solid sludge particles joined to form aggregated floc. By comparing the numerical prediction with experimental data, the usefulness of the model is confirmed and some examples of flotation simulation are demonstrated. PMID:12523755

Fujisaki, K; El-Zahar, M

2002-01-01

266

Determination of gold in gold ores  

Microsoft Academic Search

The gold content of placer gold flakes and gold bearing ores has been determined by instrumental neutron activation analysis \\/INAA\\/ and radiochemical neutron activation analysis \\/RNAA\\/. It was discovered that significant errors result in the instrumental method for gold flakes as small as 10 mg due to sample self-absorption of neutrons during irradiation. Reliable results were obtained, for both ore

C. R. Keedy; L. Parson; J. Shen

1989-01-01

267

Radiometric Sorting of Rio Algom Uranium Ore.  

National Technical Information Service (NTIS)

An ore sample of about 0.2 percent uranium from Quirke Mine was subjected to radiometric sorting by Ore Sorters Limited. Approximately 60 percent of the sample weight fell within the sortable size range: -150 + 25 mm. Rejects of low uranium content (<0.01...

M. A. Cristovici

1983-01-01

268

Miocene reefs of Dominican Republic  

SciTech Connect

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

Evans, C.C.

1988-01-01

269

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

SciTech Connect

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

Peng, F.F.

1996-05-01

270

Process of extracting both uranium and radium from uranium-containing ores  

SciTech Connect

Ferric chloride leaching at temperatures in the range 47-74/sup 0/C. is found to remove up to 97% of the uranium from ores occurring in the Elliot Lake area of Canada, but radium removal was found to be poor due to the formation of sulphates from the sulphides present in the ore. In processes of the invention the sulphides are initially removed by flotation, when aqueous acidic ferric chloride of relatively low concentration, e.g., 0.1 M can extract as much as 92% of the radium, giving tailings which are effectively sulphide-free and with radium levels approaching a desired maximum of 24 pCi/g. Radium may be removed by adsorption on manganese dioxide and uranium may be removed by liquid extraction with D2EHPA (DAPEX process). The ferric chloride may be recirculated for further leaching, with reduction before the uranium extraction and reoxidation afterwards. Because of the recycle, it is possible to keep chloride ion levels in the effluent below the prescribed level in Ontario, Canada of 750 ppm.

Nirdosh, I.; Baird, M.H.; Banerjee, S.; Muthuswami, S.V.

1984-06-12

271

The activation of sphalerite by lead — a flotation perspective  

Microsoft Academic Search

The activation of sphalerite by some metal salts has been briefly reviewed and the influence of lead nitrate on sphalerite in the presence of potassium ethyl xanthate has been investigated by a combination of batch flotation tests and solution analyses on pulps containing a mixture of sphalerite and quartz. The effect of lead addition, of pH and of complexant on

W. J. Trahar; G. D. Senior; G. W. Heyes; M. D. Creed

1997-01-01

272

The development of a cavern model for mechanical flotation cells  

Microsoft Academic Search

Certain fine particle and high solid concentration mineral slurries used in the froth flotation process have been shown to exhibit non-Newtonian rheologies, including a yield stress. The mixing characteristics of these fluids are often problematic as a cavern of yielded fluid forms around the impeller whilst the rest of the fluid remains stagnant and therefore unmixed. This paper aims to

C. W. Bakker; C. J. Meyer; D. A. Deglon

2010-01-01

273

Off-line image analysis for froth flotation of coal  

Microsoft Academic Search

Froth flotation is an effective process for separating sulphur and fine minerals from coal. Such pre-cleaning of coal is necessary in order to reduce the environmental and operation problems in power plants. The separation depends very much on particle surface properties, and the selectivity can be improved by addition of a reagent. Image analysis can be used to determine the

Caglar Citir; Zeki Aktas; Ridvan Berber

2003-01-01

274

Off-line image analysis for froth flotation of coal  

Microsoft Academic Search

Froth flotation is an effective process for separating sulphur and fine minerals from coal. Such pre-cleaning of coal is necessary in order to reduce the environmental and operational problems in power plants. The separation depends very much on particle surface properties, and the selectivity can be improved by addition of a reagent. Image analysis can be used to determine the

Caglar Citir; Zeki Aktas; Ridvan Berber

2004-01-01

275

Model-based supervision of valves in a flotation process  

Microsoft Academic Search

An observer based approach for detecting clogging in valves in flotation processes is investigated. Integral action and linear feedback applied to a nonlinear process model constitutes the observer for which local stability is shown. The integral terms give estimates of the clogging in the valves of the process and this estimate is compared to a constant threshold. Experiments on real

Michael Bask; Andreas Johansson

2003-01-01

276

A Classification of Flotation Froth Based on Geometry  

Microsoft Academic Search

In order to get the exact information of the bubble distribution which is extracted by the watershed transformation algorithm, because of the abnormity of the bubble shape, using the ellipsoidal shape to calculate the major and minor axes is the most appropriate method to describe the flotation froth. At the same time, it was found that weighting by cross sectional

Yang Li; Xiaozhu Lin; Guoqing Zhao

2007-01-01

277

Electrical Aspects of Adsorbing Colloid Flotation. III. Excluded Volume Effects  

Microsoft Academic Search

The separation rates of precipitate flotation separations are calculated from a simple model and a more exact model based upon the Gouy-Chapman approach. The finite volume of the floc particles is taken into account, and the dependence of separation rates on ionic strength surface potential, charge of floc particles, and concentration of floc particles is determined.

John W. Wilson; David J. Wilson

1976-01-01

278

Modeling and simulation of separation process in flotation system  

Microsoft Academic Search

In order to design a flotation circuit to remove ink and contaminants from slushed old corrugated container (OCC) pulp suspension, a model based on mass balance was developed. The model is a five fractional model, which handles mass flow rate of ink, fiber, fines, filler and dichloromethane (DCM) extractives. A detailed method of calculating the deinking selectivity of a material

Byoung-Uk Cho; Jeong-Yong Ryu; Bong-Keun Song

2009-01-01

279

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.

1993-01-01

280

Inertial hydrodynamic particle–bubble interaction in flotation  

Microsoft Academic Search

The flotation rate of particles of different size and with different contact angles, provided by surface modification of the surface of broken quartz particles, with single monodisperse bubbles was investigated. A monotonic increase of collection efficiency was observed with increasing particle size at high particle hydrophobicity where attachment and stability are at a maximum. At smaller particle hydrophobicity the dependence

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

1999-01-01

281

Fuzzy model based control for a mineral flotation plant  

Microsoft Academic Search

This paper describes a generalized predictive control (GPC) algorithm based on fuzzy models and its application to the tailing grade control in a mineral flotation plant. The control strategy is evaluated using a dynamic process simulator and their results are compared with those obtained with a conventional GPC

A. Cipriano; M. Ramos

1994-01-01

282

Continuous air rate measurement in flotation cells: Some fundamental considerations  

Microsoft Academic Search

A robust and reliable sensor to measure gas (air) superficial velocity (Jg) continuously in flotation systems is introduced. It is based on the sampling of bubbles by buoyancy with the accumulating air allowed to exit through an orifice. At steady state, pressure drop is measured and related to the Jg by prior calibration. The continuous device is readily automated and

J. A. Torrealba-Vargas; J. A. Finch

2006-01-01

283

Alternative Flotation Techniques for Wastewater Treatment: Focus on Electroflotation  

Microsoft Academic Search

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

K. A. Matis; E. N. Peleka

2010-01-01

284

Studies on biodegradation of organic flotation collectors using Bacillus polymyxa  

Microsoft Academic Search

Biodegradation of organic flotation collectors, namely sodium isopropylxanthate, dodecylammonium acetate and sodium oleate in solution, was studied using Bacillus polymyxa. The biodegradation has been assessed under different conditions, namely during growth, in the presence of the cells, metabolite or an active culture. Xanthate biodegradation was found to be better in the presence of an active culture or metabolite, while the

Evvie Chockalingam; S Subramanian; K. A Natarajan

2003-01-01

285

Recovering Glass from Urban Refuse by Froth Flotation.  

National Technical Information Service (NTIS)

Froth flotation, using cationic reagents, has been extensively investigated by the Department of Interior's Bureau of Mines as a step in the multistage processing of urban refuse to recover glass in a form suitable for use in making new containers. Batch ...

J. H. Heginbotham

1978-01-01

286

Application of the AGF (Anoxic Gas Flotation) Process  

Microsoft Academic Search

The AGF (Anoxic Gas Flotation) process is an improved anaerobic digestion process that uses anoxic gas (without oxygen) to float, concentrate, and return bacteria, organic acids, protein, enzymes, and undigested substrate to the anaerobic digester for the rapid and complete conversion of waste slurries to gas and soluble constituents. The process has been used to treat sewage sludge (3 to

Dennis A. Burke

287

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...

288

Application of Particle Image Velocimetry During Froth Flotation of Hardcoal.  

National Technical Information Service (NTIS)

The application of a PIV system to a flotation apparatus is described. The aim of the experiments is to explore the general flow pattern in the cell and to measure the velocities and the distribution of the solid and gaseous phases. Preliminary results on...

A. Zachos M. Kaiser W. Merzkirch

1992-01-01

289

Influence of flotation tailings thickening on centrifugal flocculation performance  

Microsoft Academic Search

The dewatering and utilization of coal-cleaning wastes are important problems in connection with the control of air and water pollution in industrial areas and the recycling of production wastes in general. The most intractable technical problem is how to treat the very finely divided suspensions of flotation tailings to recover clean water for recycling and a handleable sludge. Centrifugal flocculation

V. V. Lyadov; A. V. Mikhailenkova; N. I. Yavorskaya; L. M. Gribova; A. V. Kovalchuk

1978-01-01

290

Selective Flotation of Minerals from North Carolina Mica Tailing.  

National Technical Information Service (NTIS)

Laboratory batch and small-scale continuous flotation tests were conducted on a mica waste tailing from Kings Mountain, N.C., to determine the feasibility of producing high-quality mica, feldspar, and glass sand. Mica was recovered by two methods; one was...

W. H. Eddy J. S. Browning J. E. Hardemon

1969-01-01

291

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

SciTech Connect

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

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

1995-03-01

292

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

293

Coal surface control for advanced fine coal flotation  

Microsoft Academic Search

The primary objective in the scope of this research project is to develop advanced flotation methods for coal cleaning in order to achieve near total pyritic-sulfur removal at 90% Btu recovery, using coal samples procured from three major US coal seams. Concomitantly, the ash content of these coals is to be reduced to 6% or less. Investigation of mechanisms for

D. W. Fuerstenau; K. V. S. Sastry; J. S. Hanson; J. Diao; A. De; F. Sotillo; G. Harris; P. Somasundaran; C. C. Harris; T. Vasudevan; D. Liu; C. Li; Weibai Hu; Y. Zou; W. Chen; V. Choudhry; R. Sehgal; A. Ghosh

1991-01-01

294

Coal surface control for advanced fine coal flotation  

Microsoft Academic Search

The primary objective in the scope of this research project is to develop advanced flotation methods for coal cleaning in order to achieve near total pyritic sulfur removal at 90% Btu recovery, using coal samples procured from six major US coal seams. The ash content of these coals is to be reduced to 6% or less. Investigation of mechanisms for

D. W. Fuerstenau; K. V. S. Sastry; J. S. Hanson; G. Harris; F. Sotillo; J. Diao; Y. Yin; P. Somasundaran; C. C. Harris; T. Vasudevan; D. Liu; C. Li; Weibai Hu; Y. Zou; W. Chen; V. Choudhry; R. Sehgal; A. Ghosh

1990-01-01

295

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.

296

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

297

High Latitude Reefs: A Potential Refuge for Reef Builders  

NASA Astrophysics Data System (ADS)

Coral reefs globally show variable signs of deterioration or community structure changes due to a host of anthropogenic and natural factors. In these global scenarios, rates of calcification by reef builders such as Scleractinian corals are predicted to significantly decline in the future due to the increase in atmospheric CO_2. When considering the response of reefs to the present climate change, temperature effects should also be taken into account. Here, we investigate the simultaneous impact of temperature and CO_2 on the high-latitude Bermuda coral reef system (32^oN, 64^oE)through a series of in vitro experiments at different CO_2 levels and seasonally different summer (27^oC) and winter (20^oC) temperature conditions. Four species of Scleractinian corals (Porites astreoides, Diploria labyrinthiformis, Madracis mirabilis and decactis) were acclimated for three months at: 20^oC and 27^oC (both with CO_2 levels at 400 ppm (control) and 700 ppm). Growth was assessed by buoyant weight techniques during the acclimation period. Photosynthesis, respiration and calcification were measured at the end of this period using respirometric chambers. A reproduction experiment was also undertaken under 27^oC. Photosynthesis mainly remains constant or increases under high CO_2 conditions. The results of the integrated calcification measurements confirm the hypothesis that an increase in CO_2 induces a decrease in calcification. However an increase in photosynthesis can be observed when CO_2 is unfavorable for calcification suggesting that a biological control of calcification through photosynthesis could prevent a drop in the calcification potential. Buoyant weight results indicate that the CO_2 impact could be less detrimental under lower temperature. This result will be compared with the instantaneous calcification measurements in the chambers and some in situ coral growth assessments in winter and summer conditions. The consequences for the response of marginal reefs undergoing high seasonal temperature variations will finally be discussed.

Amat, A.; Bates, N.

2003-04-01

298

Contradictions to Darwin's Evolution of Reef Types in Barrier Reef Relationships  

NASA Astrophysics Data System (ADS)

The Darwinian progressive subsidence model for the evolution of fringing reefs, barrier reefs and atolls has been generally accepted following the indisputable proof of subsidence provided by drilling results in the Pacific. Nonetheless, there are data that do not fit the expectations of the model, such as the similar lagoon depths of barrier reefs and atolls as opposed to the subsidence theory's implicit prediction that atolls should have significantly greater depths. In contrast, much evidence supports the influence of meteoric-water solution on barrier reef morphology. For example, the maximum lagoon depth of the 56 modern barrier reefs is statistically correlated with the lagoon catchment area for modern annual rainfall. These modern rainfall patterns are a reasonable proxy for relative geographic differences in glacial lowstand rainfall, even though the absolute amounts of such rainfall are unknown. The correlation therefore stongly suggests the importance of Pleistocene subaerial solution in contributing to barrier reef morphology. Further support for antecedent influence occurs in the form of barrier reef passes in which the depth of the reef pass is correlated with onshore drainage volumes. On a larger scale, the Cook Island of Mangaia provides evidence that solution can produce barrier reef morphology independent of reef development. In contrast, there are no examples of the Darwinian subsidence-predicted lagoon transition of fringing reefs to barrier reefs to atolls. Moreover, the common occurrence of fringing reefs within barrier reefs negates subsidence as a causal factor in their presumed progressive evolutionary development. Consequently, the evidence points to a solution morphology template which has been accentuated by reef construction to produce the diagnostic barrier reef morphology we see today. Rapid subsidence of seamounts by flexural loading during their early history, combined with Pleistocene sealevel fluctuations results in permanent drowning of older barrier reef. The importance of slower, thermal subsidence is in accounting for the overall thickness of the resulting carbonate caps.

Purdy, E.; Winterer, E. L.

2004-05-01

299

New evidence for the barrier reef model, Permian Capitan Reef complex, New Mexico  

SciTech Connect

Recent paleontologic and petrologic observations suggest that the Capitan Formation was deposited as an organic or ecologic reef that acted as an emergent barrier to incoming wave energy. In outcrops in the Guadalupe Mountains and within Carlsbad Caverns, massive reef boundstone contains a highly diverse assemblage of frame-building and binding organisms. In modern reefs, diversity among frame builders decreases dramatically with depth. Marine cement is abundant in reef boundstone, but limited in back-reef grainstone and packstone. This cementation pattern is similar to that observed in modern emergent barrier reef systems. Based on comparison with modern analogs, these dasycladrominated back-reef sediments and their associated biota are indicative of shallow, hypersaline conditions. Few of these dasyclads exhibit broken or abraded segments and some thallus sections are still articulated suggesting that low-energy, hypersaline conditions occurred immediately shelfward of the reef. In addition, large-scale topographic features, such as possible spur and groove structures between Walnut Canyon and Rattlesnake Canyon, and facies geometries, such as the reef to shelf transition, resemble those found in modern shallow-water reefs. The organisms that formed the Capitan Reef appear to have lived in, and responded to, physical and chemical conditions similar to those that control the geometry of modern shallow-water reefs. Like their modern counterparts, they seem to have strongly influenced adjacent environments. In light of this evidence, consideration should be given to either modifying or abandoning the marginal mound model in favor of the originally proposed barrier reef model.

Kirkland, B.L.; Moore, C.H. Jr. (Louisiana State Univ., Baton Rouge (USA))

1990-05-01

300

Biological destruction of coral reefs  

Microsoft Academic Search

The major agents of biological destruction of coral reefs can be divided into grazers, etchers and borers. Each of these groups is reviewed on a world wide basis, together with the mechanisms by which they destroy the coral substrate. Rates of bioerosion attributed to major agents of grazers, etchers and borers are given, together with limitations of some of the

P. A. Hutchings

1986-01-01

301

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

302

The Formation of Coral Reefs  

Microsoft Academic Search

IN NATURE for February 18 there is a paper by Mr. J. S. Gardiner giving a concise account of his theory of coral reefs. A more extended paper by him on the same subject appeared in the Geographical Journal for 1902, and was followed last year by one by Mr. Günther on erosion on the west coast of Italy; the

Ernest H. L. Schwarz

1904-01-01

303

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

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

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

304

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

305

Microbial community study of the iron ore concentrate of the Sishen Iron Ore Mine, South Africa  

Microsoft Academic Search

As a result of the advancing global technologies and civilisation, there has been a progressive depletion of high-grade mineral\\u000a deposits. Consequently, it has become increasingly important to process lower-grade ores. Phosphorous (P) and particular potassium\\u000a (K) contained in the iron ore concentrates of the Sishen Iron Ore Mine have a detrimental effect on the steel making process,\\u000a whereby these alkali’s

P. J. Williams; T. E. Cloete

2008-01-01

306

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

307

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

308

Recovering Copper Values from Oxidized Ores.  

National Technical Information Service (NTIS)

A process is presented for recovering copper from oxidized ores such as azurite, malachite or chrysacolla. This is done by alkaline leachants having incorporated therein siliceous material to inhibit the dehydration of the formed copper complex. This perm...

P. R. Haskett D. J. Bauer C. H. Elges R. E. Lindstrom

1976-01-01

309

Extraction of Silver from Refractory Ores.  

National Technical Information Service (NTIS)

Silver ores from the Candelaria District, Nevada, and Round Mountain District Colorado, were investigated mineralogically and metallurgically. Silver minerals of four distinct groups were identified: (1) silver sulfide; (2) argentojarosite; (3) silver con...

B. J. Scheiner D. L. Pool J. J. Sjoberg R. E. Lindstrom

1973-01-01

310

Smelting ferroalloys by means of borate ores  

Microsoft Academic Search

Borate ore is investigated in the smelting of ferrosilicon, silicochrome, and carbon ferrochrome. A method by which high-basicity\\u000a smelting slags of refined ferrochrome may be stabilized is proposed.

A. S. Kim

2008-01-01

311

Extraction of Copper from Sulfide Ores.  

National Technical Information Service (NTIS)

In the patent application copper is extracted from sulfide ores or concentrates by electrolysis in a cell having separate anode and cathode sections, and having an intermediate liquid copper-mercury alloy electrode between the anode and cathode sections.

T. A. Henrie R. E. Lindstrom K. P. V. Lei

1976-01-01

312

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

313

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

314

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

Microsoft Academic Search

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

Eberhard Gischler

1994-01-01

315

Trade off analysis for participatory coral reef management: lessons learned from Buccoo Reef Marine Park, Tobago  

Microsoft Academic Search

Coral reefs provide a range of important functions and services, yet often conflicts exist over coral reef use among multiple users. This paper outlines the trade-off analysis approach to coral reef management where multiple and conflicting objectives for coral reef resources can be identified, assessed and reconciled within a decision-support framework. The paper applies trade-off analysis to the case of

E. Tompkins; K. Brown; W. N. Adger; P. Bacon; K. Young; D. Shim

316

Episodes of reef growth at Lord Howe Island, the southernmost reef in the southwest Pacific  

NASA Astrophysics Data System (ADS)

Lord Howe Island lies at the present latitudinal limit to reef growth in the Pacific and preserves evidence of episodes of reef development over the Late Quaternary. A modern fringing reef flanks the western shore of Lord Howe Island, enclosing a Holocene lagoon, and Late Quaternary eolianites veneer the island. Coral-bearing beach and shallow-water calcarenites record a sea level around 2 3 m above present during the Last Interglacial. No reefs or subaerial carbonate deposits occur on, or around, Balls Pyramid, 25 km to the south. The results of chronostratigraphic studies of the modern Lord Howe Island reef and lagoon indicate prolific coral production during the mid-Holocene, but less extensive coral cover during the late Holocene. Whereas the prolific mid-Holocene reefs might appear to reflect warmer sea-surface temperatures, the pattern of dates and reef growth history are similar to those throughout the Great Barrier Reef and across much of the Indo-Pacific and are more likely correlated with availability of suitable substrate. Little direct evidence of a Last Interglacial reef is now preserved, and the only evidence for older periods of reef establishment comes from clasts of coral in a well-cemented limestone unit below a coral that has been dated to the Last Interglacial age in a core at the jetty. However, a massive reef structure occurs near the centre of the wide shelf around Lord Howe Island, veneered with Holocene coralline algae. Its base is 40 50 m deep and it rises to water depths of less than 30 m. This fossil reef is several times more extensive than either Holocene or Last Interglacial reefs appear to have been. Holocene give-up reef growth is inferred during the postglacial transgression, but an alternative interpretation is that this is a much older landform, indicating reefs that were much more extensive than modern reefs at this marginal site.

Woodroffe, C. D.; Dickson, M. E.; Brooke, B. P.; Kennedy, D. M.

2005-12-01

317

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

318

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...

319

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

320

Mineral chemical study of U-bearing minerals from the Dominion Reefs, South Africa  

NASA Astrophysics Data System (ADS)

The Neo-Archean Dominion Reefs (~3.06 Ga) are thin meta-conglomerate layers with concentrations of U- and Th-bearing heavy minerals higher than in the overlying Witwatersrand Reefs. Ore samples from Uranium One Africa's Rietkuil and Dominion exploration areas near Klerksdorp, South Africa, were investigated for their mineral paragenesis, texture and mineral chemical composition. The ore and heavy mineral assemblages consist of uraninite, other uraniferous minerals, Fe sulphides, Ni-Co sulfarsenides, garnet, pyrite, pyrrhotite, monazite, zircon, chromite, magnetite and minor gold. Sub-rounded uraninite grains occur associated with the primary detrital heavy mineral paragenesis. U-Ti, U-Th minerals, pitchblende (colloform uraninite) and coffinite are of secondary, re-mobilised origin as evidenced by crystal shape and texture. Most of the uranium mineralisation is represented by detrital uraninite with up to 70.2 wt.% UO2 and up to 9.3 wt.% ThO2. Re-crystallised phases such as secondary pitchblende (without Th), coffinite, U-Ti and U-Th phases are related to hydrothermal overprint during low-grade metamorphism and are of minor abundance.

Rantzsch, Ulrike; Gauert, Christoph D. K.; van der Westhuizen, Willem A.; Duhamel, Isabelle; Cuney, Michel; Beukes, Gerhard J.

2011-02-01

321

Philippine Coral Reefs Under Threat: Lessons Learned After 25 Years of Community-Based Reef Conservation  

Microsoft Academic Search

The Philippine archipelago consists of more than 7000 islands. Most of these islands have extensive coral reefs or coral communities. For centuries, reefs and their associated resources have provided the livelihood for a large portion of the coastal population. However, reefs as sources of income are threatened by over-exploitation and by the use of destructive fishing methods. The scientific community,

Alan T White; Helge P Vogt

2000-01-01

322

Larval reef fish could use odour for detection, retention and orientation to reefs  

Microsoft Academic Search

While evidence is mounting that larval reef fish are active participants in the process of dispersal and settlement, the sensory and behavioural mechanisms by which these fishes disperse and return from their oceanic phase to the reefs remain unknown. On One Tree Island (Great Barrier Reef, Australia), we tested freshly collected animals in a large choice-flume on the shore. Here,

Jelle Atema; Michael J. Kingsford; Gabriele Gerlach

2002-01-01

323

New evidence for the barrier reef model, Permian Capitan Reef complex, New Mexico  

Microsoft Academic Search

Recent paleontologic and petrologic observations suggest that the Capitan Formation was deposited as an organic or ecologic reef that acted as an emergent barrier to incoming wave energy. In outcrops in the Guadalupe Mountains and within Carlsbad Caverns, massive reef boundstone contains a highly diverse assemblage of frame-building and binding organisms. In modern reefs, diversity among frame builders decreases dramatically

B. L. Kirkland; C. H. Jr. Moore

1990-01-01

324

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.

325

Atlantic coral reefs: the transplantation alternative  

Microsoft Academic Search

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

John C. Briggs

2009-01-01

326

Oyster Reefs as Complex Ecological Systems  

Microsoft Academic Search

Aggregations of suspension-feeding organisms like oyster reefs, mussel beds and worm reefs are prominent systems in coastal\\u000a environments. The fundamental properties of these systems are reviewed and indicate that they are complex systems that are\\u000a highly optimized and evolutionarily selected for high productivity. Such systems are unstable when faced with a never experienced\\u000a situation. In the case of oyster reefs,

Richard Dame

327

Climate change and coral reef connectivity  

Microsoft Academic Search

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

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

2009-01-01

328

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

329

Coral reef ecosystems and anthropogenic climate change  

Microsoft Academic Search

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

Ove Hoegh-Guldberg

2011-01-01

330

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

331

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

332

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

333

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

334

Satellite Remote Sensing of Coral Reefs  

NSDL National Science Digital Library

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

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

2005-09-01

335

Impacts of Artificial Reefs on Surrounding Ecosystems  

NASA Astrophysics Data System (ADS)

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

Manoukian, Sarine

336

Using alternative chemicals in the flotation of heavy metals from lead mill tailings  

SciTech Connect

The U.S. Bureau of Mines (USBM) investigated alternative chemicals for the flotation of heavy metal values from southeast Missouri lead mill tailings. The objectives of the study were to lower the Pb remaining in the reprocessed tailings to <500 ppm, concentrate the metal values, and lower the overall toxicity of the flotation reagent scheme. Due to the high toxicity of classic flotation chemicals, collectorless flotation, as well as nontoxic or less-toxic chemicals, was studied for use in the flotation process. The investigation centered on the National tailings pile in Flat River, MO. Advantages to using alternative chemicals for the flotation process are presented. Novel reagent schemes are discussed for the treatment of the tailings. Various nontoxic or less-toxic oils were tested, and a substitute for sodium sulfide was investigated. Using a food additive oil, soda ash, and a frother as the reagent scheme, froth flotation recovered 89% of the Pb values. Further scavenging lowered the Pb remaining in the reprocessed tailings to <500 ppm. A less-toxic substitute for sodium cyanide was also studied for use in the cleaner flotation stages. Preliminary results indicate that the food additive oil, canola oil, to be as effective as classic sulfide flotation reagents.

Benn, F.W. [Bureau of Mines, Rolla, MO (United States)

1995-04-01

337

Broadband Ultrasonic Target Strengths of Hollow Ceramic Flotation Spheres  

Microsoft Academic Search

The target strengths of hollow ceramic flotation spheres manufactured by DeepSea Power and Light, Inc., and tested to a pressure equivalent of 12,000 m have been measured as a function of frequency over the bands 10-150 kHz. The spheres are made of alumina, purity 99.9%, with diameter 91.44 plusmn 0.2 mm, nominal thickness 1.3 mm, mass 140 plusmn 1 g.

P. R. Atkins; D. T. I. Francis; K. G. Foote

2007-01-01

338

On modelling of bubble–particle attachment probability in flotation  

Microsoft Academic Search

We have developed the theoretical basis for experimental determination of bubble–particle attachment probability in single-bubble flotation experiments. We use these experimentally determined data to simulate the dependence of induction time on particle size. Using these simulated results, we verify the bubble–particle attachment probability prediction developed on the basis of sliding time and induction time (the Sutherland approach). We have calculated

Anh V Nguyen; John Ralston; Hans J Schulze

1998-01-01

339

Flotation froth monitoring using multiresolutional multivariate image analysis  

Microsoft Academic Search

A novel image analysis solution based on multiresolutional multivariate image analysis (MR-MIA) is proposed for the monitoring and control of flotation processes. The approach is quite different from the contemporary image analysis approaches in the sense that it can handle spatial (i.e., morphological) and color information of froth images efficiently, and is inherently robust to image quality and lighting conditions.MR-MIA

J. J. Liu; J. F. MacGregor; C. Duchesne; G. Bartolacci

2005-01-01

340

Correlating Cryptosporidium removal using dissolved air flotation in water treatment  

Microsoft Academic Search

Cryptosporidium parvum behaves similarly to other low density colloidal particles in water. Their physical removal requires destabilization and subsequent separation. Removal as high as 4.9 log-units has been reported for gravity sedimentation but the average removal tends to be less than 2 log-units. Dissolved air flotation (DAF) is a method of water treatment that has been used primarily for sludge

Kathy French; Rodney K Guest; Gordon R Finch; Charles N Haas

2000-01-01

341

Surface chemistry and flotation of cassiterite with alkyl hydroxamates  

Microsoft Academic Search

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

T. Sreenivas; N. P. H. Padmanabhan

2002-01-01

342

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

NASA Astrophysics Data System (ADS)

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

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

2008-03-01

343

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

344

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

345

Heterocoagulation of chalcopyrite and pyrite minerals in flotation separation.  

PubMed

Heterocoagulation between various fine mineral particles contained within a mineral suspension with different structural and surface chemistry can interfere with the ability of the flotation processes to selectively separate the minerals involved. This paper examines the interactions between chalcopyrite (a copper mineral) and pyrite (an iron mineral often bearing gold) as they approach each other in suspensions with added chemicals, and relates the results to the experimental data for the flotation recovery and selectivity. The heterocoagulation was experimentally studied using the electrophoretic light scattering (ELS) technique and was modelled by incorporating colloidal forces, including the van der Waals, electrostatic double layer and hydrophobic forces. The ELS results indicated that pyrite has a positive zeta potential (zeta) up to its isoelectric point (IEP) at approximately pH 2.2, while chalcopyrite has a positive zeta up to its IEP at approximately pH 5.5. This produces heterocoagulation of chalcopyrite with pyrite between pH 2.2 and pH 5.5. The heterocoagulation was confirmed by the ELS spectra measured with a ZetaPlus instrument from Brookhaven and by small-scale flotation experiments. PMID:15894282

Mitchell, Timothy K; Nguyen, Anh V; Evans, Geoffrey M

2005-06-30

346

Conservation, precaution, and Caribbean reefs  

NASA Astrophysics Data System (ADS)

Some authors argue that overfishing is an important reason that reef corals have declined in recent decades. Their reasoning is that overfishing removes herbivores, releasing macroalgae to overgrow and kill the corals. The evidence suggests, however, that global climate change and emergent marine diseases make a far greater contribution to coral mortality, and that macroalgae generally grow on the exposed skeletal surfaces of corals that are already dead. Macroalgal dominance, therefore, is an effect rather than a cause of coral mortality. Marine protected areas (MPAs), which are usually established to protect stocks of reef fish, foster populations of herbivorous fish under at least some circumstances. Increased herbivory can reduce algal cover, potentially accelerating the recovery of coral populations inside MPAs; however, establishing MPAs will have only a limited impact on coral recovery unless policymakers confront the accelerating negative effects of the global-scale sources of coral mortality.

Aronson, Richard B.; Precht, William F.

2006-08-01

347

Biogeochemistry of inter-reef sediments on the northern and central Great Barrier Reef  

Microsoft Academic Search

The deposition and cycling of carbon and nitrogen in carbonate sediments located between coral reefs on the northern and central\\u000a sections of the Great Barrier Reef were examined. Rates of mass sediment accumulation ranged from 1.9 kg m?2 year?1 (inshore reefs) to 2.1–4.9 kg m?2 year?1 (between mid-shelf reefs); sedimentation was minimal off outer-shelf reefs. Rates of total organic carbon decomposition ranged\\u000a from 1.7 to 11.4 mol C m?2 year?1

D. M. Alongi; L. A. Trott; J. Pfitzner

2008-01-01

348

Bioindication in coral reef ecosystems.  

PubMed

The concept of bioindication in the sense of the use of organisms for detecting environmental stress has been employed in coral reef conservation and management for the past several years. Important tools are coral growth rates and various community parameters, notably hard coral cover. The present need is the optimal coordination of international efforts for the earliest possible institution of an effective monitoring system. PMID:2884790

Yap, H T

1986-01-01

349

A novel reef coral symbiosis  

Microsoft Academic Search

Reef building corals form close associations with unicellular microalgae, fungi, bacteria and archaea, some of which are symbiotic\\u000a and which together form the coral holobiont. Associations with multicellular eukaryotes such as polychaete worms, bivalves\\u000a and sponges are not generally considered to be symbiotic as the host responds to their presence by forming physical barriers\\u000a with an active growth edge in

O. Pantos; J. C. Bythell

2010-01-01

350

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

351

Advanced control system for fine coal flotation. Fifth quarterly technical progress report, October 1, 1996--December 31, 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 ...

G. T. Adel G. H. Luttrell

1997-01-01

352

Modified release analysis procedure using advanced froth flotation mechanisms. Final technical report, September 1, 1995--August 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 M. K. Mohanty

1997-01-01

353

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

354

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

355

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

356

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.

357

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

358

Artificial Reefs--A Coastal Classroom Project.  

ERIC Educational Resources Information Center

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

Dindo, John J.

1986-01-01

359

Artificial Reefs--A Coastal Classroom Project.  

ERIC Educational Resources Information Center

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

Dindo, John J.

1986-01-01

360

Phosphorus and nitrogen in coral reef sediments  

Microsoft Academic Search

The occurrence of P and N in the sediments has been investigated on Davies Reef in the central region of the Great Barrier Reef Complex. Concentrations of inorganic P and N in the water were typical of nutrient-depleted tropical surface water. Carbonate sediments were found to contain a uniform pool of P (300 ppm by wt), principally in the form

BARRIE ENTSCH; KEVIN G. BOTO; ROBIN G. SIM; JOHN T. WELLINGTON

1983-01-01

361

Ancient reef ecosystem expansion and collapse  

Microsoft Academic Search

Platform carbonate and, particularly, reef ecosystem development (with reefs representing the acme of carbonate platform growth) were highly cyclical in early to mid Paleozoic time, especially in relation to known or postulated times of global warming or cooling. These cycles do not appear to correspond to postulated 26 Ma rhythms seen in diversity patterns, nor were they regular. There were

P. Copper

1994-01-01

362

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

363

Preliminary observations on coral reef plankton  

Microsoft Academic Search

ABSTBRCT Plankton collections near coral reefs were made by hand-towing nets while swimming and by using a suction device for sampling caves. Plankton in sheltered areas was con- sidcrably different from that in nonsheltered areas; some plankton forms maintained position near coral reefs, indicating that the terms planktonic and epibenthic may represent extremes of a behavior continuum. Copepods were observed

ALAN R. EMERY

1968-01-01

364

Artificial Reefs and Mass Marine Ecotourism  

Microsoft Academic Search

Deploying artificial reefs on the seabed has become popular in diving management. This practice has been advocated as a means towards meeting both ecological concerns and recreational divers’ demands for diversification and themed experiences. Nevertheless, the perceptions of the user community itself – the scuba divers – regarding the establishment of artificial reefs have received only limited attention in the

Amir Shani; Omer Polak; Nadav Shashar

2011-01-01

365

Artificial Reefs and Mass Marine Ecotourism  

Microsoft Academic Search

Deploying artificial reefs on the seabed has become popular in diving management. This practice has been advocated as a means towards meeting both ecological concerns and recreational divers’ demands for diversification and themed experiences. Nevertheless, the perceptions of the user community itself – the scuba divers – regarding the establishment of artificial reefs have received only limited attention in the

Amir Shani; Omer Polak; Nadav Shashar

2012-01-01

366

Bathymetric distribution of foraminifera in Jamaican reef environments  

SciTech Connect

Recent foraminifera inhabiting Jamaican north-coast fringing reefs display variations in distributional patterns that are related to bathymetry and reef morphology. Sediment samples containing foraminifera were collected along a profile that traversed the back reef (depth 1-2 m), fore-reef terrace (3-15 m), fore-reef escarpment (15-27 m), fore-reef slope (30-55 m), and upper deep fore reef (70 m). Approximately 150 species distributed among 80 genera were identified from the samples. Preliminary analyses indicate that diversity values (S, H') are lowest on the fore-reef terrace (79, 3.0, respectively), increase similarly in back-reef and fore-reef escarpment and slope settings (93, 3.4), and are highest on the deep fore reef (109, 3.7). Larger groupings (suborders) exhibit distinct bathymetric trends with miliolids occurring more commonly in back-reef (comprising 51% of the fauna) than in fore-reef (28%) zones, whereas agglutinated and planktonic species occur more commonly in deeper reef (> 15 m, 9% and 4%, respectively) than in shallower reef zones (< 15 m, 3%, and 0.5%, respectively). Among the more common species Amphistegina gibbosa (Rotolina) is much more abundant in fore-reef (3%) environments, and Sorites marginalis (Miliolina) occurs almost exclusively in the back reef, where it comprises 5.5% of the fauna. Q-mode cluster analysis, involving all species collected, enabled the delineation of back-reef, shallow fore-reef, and deeper fore-reef biofacies, also indicating the potential utility of foraminiferal distributions in detailed paleoenvironment interpretations of ancient reef settings.

Martin, R.E.; Liddell, W.D.

1985-02-01

367

Habitat effects and sampling bias on Phanerozoic reef distribution  

Microsoft Academic Search

Incomplete preservation, heterogeneous geographic sampling, uncertainties in palaeogeographic reconstructions and inconsistencies of reef definitions bias global reef patterns observed in the geological record. This sampling bias is added to a biological habitat area effect, which is thought to be of paramount importance for modern reefs. To evaluate the importance of sampling bias of ancient reefs, I first tested the habitat

Wolfgang Kiessling

2005-01-01

368

Artificial reef debate: Habitat enhancement or waste disposal?  

Microsoft Academic Search

Modern artificial reef projects are taking novel approaches to fishery habitat construction. Development of these reefs may involve the use of obsolete oil platforms, concrete blocks mixed with municipal incinerator ash, or even automobile tires. Because modern reef designs make use of materials heavily regulated by ocean dumping agreements and statutes, concern arises as to the effects of these reefs

John M. Macdonald

1994-01-01

369

Shifting the paradigm of coral-reef ‘health’ assessment  

Microsoft Academic Search

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

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

2005-01-01

370

Wave Forced Normal Modes on Fringing Reefs  

NASA Astrophysics Data System (ADS)

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

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

2008-12-01

371

Packed-Bed Column Flotation of Fine Coal. Part II. Technical — Economic Feasibility and Scale-up Considerations  

Microsoft Academic Search

An economic analysis revealed that the new packed-bed flotation column is superior to conventional flotation cells for reduction of ash and pyritic sulfur. Furthermore, commercial packed-bed flotation columns can be designed on a direct scale-up basis.

D. C. YANG

1990-01-01

372

Performance of Vegetable Oils as Flotation Collectors for the Recovery of Coal from Coal Fines Wastes  

Microsoft Academic Search

The objective of this work is to study the feasibility of using vegetable oils which are available, renewable and nonpolluting energy resources as flotation reagents for the recovery of coal from coal fines wastes. To comply with this objective, crude SOC soyabean oil and a used AB olive oil of household origin were used as collectors in the flotation of

M. I. ALONSO; C. CASTANO; A. B. GARCIA

2000-01-01

373

Identification and optimizing control of a rougher flotation circuit using an adaptable hybrid-neural model  

Microsoft Academic Search

In this paper the identification and control of a rougher flotation process is studied using an adaptable hybrid-neural model. The model is based on first principles and a PCA neural network is used for flotation kinetics estimation. Initially, the hybrid model is used for the identification, from input\\/output data obtained with a realistic phenomenological model, of a series of four

F. A. Cubillos; E. L. Lima

1997-01-01

374

The effect of surfactant concentration on batch flotation mineral flux and froth structure  

Microsoft Academic Search

It is known that the froth structure plays an important role in the flotation separation achieved. The appearance of the upper bubble surface is indicative of the internal froth structure, and is used qualitatively as a basis for control in industrial flotation cells.A quantitative kinetic model based on the flux of loaded bubble surface overflowing the concentrate weir in a

R. A. Asplin; N. Sadr-kazemi; J. J. Cilliers

1998-01-01

375

A combined morphological and color based approach to characterize flotation froth bubbles  

Microsoft Academic Search

Flotation process monitoring and control are complex targets due to the highly non-linear behavior of the process and the large number of variables involved. Control is generally achieved by adopting a human based approach. By observing the surface of flotation cells, experienced plant operators suggest, on the basis of their experience, control actions such as changing the cell level set

Giuseppe Bonifazi; Silvia Serranti; Fabio Volpe; Riccardo Zuco

1999-01-01

376

The Removal of Emulsified Oil Particles: Verification of the Flotation Model Based on Interception  

Microsoft Academic Search

The removal of several liquid alkanes from their O\\/W type emulsions was carried out by bubble column aeration. For the calculation of the removal efficiency, hydrodynamic models based on the theory of fine particle flotation were applied. Equations derived by Sato for the interception of oil particles can be used for the mathematical description of flotation of alkanes whose vapor

Krystyna B. Medrzycka

1993-01-01

377

IDENTIFICATION AND MULTIVARIABLE NONLINEAR PREDICTIVE CONTROL OF A PILOT FLOTATION COLUMN  

Microsoft Academic Search

Since measurements of recovery and grade are often complex and inaccurate, flotation columns are controlled using secondary variables, such as froth depth, bias and gas hold-up. This paper describes the control of the froth depth and the bias of a pilot flotation column by manipulating the tails and the wash water flowrate setpoints. Using two virtual sensors, one for the

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

378

ECONOMICAL EFFECTS OF ON-LINE ELEMENTAL ANALYSIS PERFORMANCE ON FLOTATION CONTROL  

Microsoft Academic Search

The paper studies the control performance of the flotation process as a function of the measurement accuracy and sampling frequency of an on-stream XRF analyzer, using a simple dynamic model. An additional aim is to assess how the economical result of a mineral flotation process depends on the quality of process control based on the on- line elemental assays. The

379

Investigation of froth flotation for beneficiation of printed circuit board comminution fines  

Microsoft Academic Search

Froth flotation for beneficiation of printed circuit board comminution fines was investigated in this work, via reverse flotation under a scheme described as natural hydrophobic response. With no reagents, the scheme employed variation of kinetic parameters of airflow rate and impeller speed to optimize metallic enrichment of the sink. The impeller energy and aeration rate required to keep the pulp

I. O. Ogunniyi; M. K. G. Vermaak

2008-01-01

380

Adhesion of two bacteria onto dolomite and apatite: their effect on dolomite depression in anionic flotation  

Microsoft Academic Search

Bacteria can adhere to mineral surfaces and affect subsequent flotation of the minerals. In the present study, the adhesion of Bacillus subtilis and Mycobacterium phlei onto dolomite and apatite was studied by sorption measurements and scanning electron microscopy. The effect of the microorganisms on the oleate flotation of the minerals was then compared at several different pH values. It was

Xiapeng Zheng; Peggy J. Arps; Ross W. Smith

2001-01-01

381

Polymer flotation and activated carbon adsorption treatment for in situ tar sand process water  

Microsoft Academic Search

Process waters collected during a Department of Energy's in situ tar sand extraction experiment near Vernal, Utah were treated by polymer assisted induced air flotation and activated carbon adsorption. The flotation process removed over 99 percent of the organic load as emulsified bitumen but did little to reduce residual toxicity in the effluents. Activated carbon adsorption was needed to remove

W. F. McTernan; W. E. Blanton; G. D. Boardman; B. T. Nolan; D. J. Kocornik

1986-01-01

382

Calcium soaps in flotation deinking; fundamental studies using surface force and coagulation techniques  

Microsoft Academic Search

The surface force technique was shown to give useful information concerning the interaction of fatty acid flotation collectors and calcium activator with a negatively charged mica substrate at high pH. Since the surface of ink particles under deinking conditions are enriched mainly by negatively charged groups, these experiments enabled some details of the fundamental mechanisms involved in deinking flotation to

M. Rutland; R. J. Pugh

1997-01-01

383

A review of plastics waste recycling and the flotation of plastics  

Microsoft Academic Search

This paper summarizes the importance of plastic waste recycling and plastic waste separation. Based on an analysis of the physical and chemical characteristics of plastics and plastic waste, the potentials and limitations of several technological processes are discussed. In addition, a review of the surface chemical aspects of plastic flotation is presented. It can be concluded that the flotation of

Huiting Shent; R. J. Pugh; E. Forssberg

1999-01-01

384

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

Microsoft Academic Search

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

J. M. Hargrave; S. T. Hall

1997-01-01

385

Selective flotation of bastnaesite from monazite in rare earth concentrates using potassium alum as depressant  

Microsoft Academic Search

Electrokinetic and flotation studies were carried out on single particles of bastnaesite and monazite to develop a flotation scheme for selectively removing monazite in the rare earth bulk concentrate from the Baiyunebo mine, in China (60.7% rare earth oxides or REO, 75% as bastnaesite and 25% as monazite). Low additions of potassium alum were found to efficiently depress monazite at

Jun Ren; Shaoxian Song; Alejandro Lopez-Valdivieso; Shouci Lu

2000-01-01

386

The effect of fine grinding on the production of superclean coal by flotation  

Microsoft Academic Search

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 the liberation and removal of sulfur-bearing and ash-forming mineral matter from coal. The beneficiation of micronized coal by froth flotation has

K. J. Miller; Wu-Wey Wen

1985-01-01

387

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

388

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

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

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

389

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

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

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

390

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

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

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

391

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

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

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

392

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

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

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

393

Extraction of Gold from Carbonaceous Ores: Pilot Plant Studies.  

National Technical Information Service (NTIS)

Oxidation procedures based on the chlorine-hypochlorite system were investigated for improving gold recovery from carbonaceous gold ores. The oxidation pretreatment prior to cyanidation was accomplished by: (1) Addition of sodium hypochlorite to ore pulp;...

B. J. Scheiner D. G. Peterson R. E. Lindstrom W. J. Guay

1972-01-01

394

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

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

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

395

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

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

CONTEXT VIEW ALONG EXISTING PERIMETER TRACKS LOOKING OVER IRON ORE CARS TOWARDS CLEVELAND BULK TERMINAL BUILDINGS. LOOKING SOUTH. - Pennsylvania Railway Ore Dock, Lake Erie at Whiskey Island, approximately 1.5 miles west of Public Square, Cleveland, Cuyahoga County, OH

396

CONTEXT VIEW SHOWING MODERN TRACKS PASSING UNDER HULETTS AND ORE ...  

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

CONTEXT VIEW SHOWING MODERN TRACKS PASSING UNDER HULETTS AND ORE YARD. LOOKING NORTHEAST. - Pennsylvania Railway Ore Dock, Lake Erie at Whiskey Island, approximately 1.5 miles west of Public Square, Cleveland, Cuyahoga County, OH

397

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

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

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

398

Patterns in the distribution of the crinoid community at Davies Reef on the central Great Barrier Reef  

Microsoft Academic Search

The crinoid community of Davies Reef, a midshelf reef in the central Great Barrier Reef, was systematically sampled in all major crinoid habitats. A total of 294 individuals of 27 species-level taxa was found in 25 sites across the reef. Of these 27 taxa, 20 were confidently assigned to known species. The 25 sitesx27 taxa matrix was subjected to an

R. H. Bradbury; R. E. Reichelt; D. L. Meyer; R. A. Birtles

1987-01-01

399

Removal of trace levels of phenols from aqueous solution by foam flotation  

SciTech Connect

Pentachlorophenol (PCP) was removed from water by foam flotation with the cationic surfactant cetyltrimethylammonium bromide (CTAB). With initial PCP concentrations of 20 ppm or less, residual PCP concentrations of less than 0.05 ppm were obtained after 5 min flotation. The CTAB concentration and flotation time are directly related to the amount of PCP removed. PCP removal is most efficient at neutral to basic pH and at low ionic strength. PCP removal is less effective with sodium dodecyl sulfate. As much as 80% of the CTAB can be replaced by dodecylamine without inhibiting PCP removal. Alcohols up to 10% by volume do not affect PCP removal. Other phenols can be removed equally well be foam flotation if the phenol is in the anionic form during flotation.

Nyssen, G.A.; Lovell, G.S.; Simon, A.A.; Smith, J.G.; Tolar, B.K.; Wilson, D.J.

1987-11-01

400

Method for concentrating the exinite group macerals from coal by froth flotation  

SciTech Connect

A method for separating the exinite group macerals from the total coal by froth flotation in the presence of at least one short chain alcohol frothing agent and at least one methyl polyglycol type frothing agent in a first froth flotation zone to produce an exinite and other coal maceral-rich stream which is thereafter subjected to froth flotation in a second froth flotation zone in the presence of a short chain alcohol frothing agent to produce an exinite group maceral-rich stream and a stream rich in other coal macerals with the exinite-rich stream thereafter being mixed with an additional quantity of a short chain alcohol frothing agent and passed to a third froth flotation zone to produce an exinite group maceral group concentrate stream which is thereafter processed to produce a particulate exinite maceral group concentrate.

Laros, T.J.; Pick, R.D.

1983-03-22

401

Effect of ultrasound on flotation kinetics in the reactor-separator  

NASA Astrophysics Data System (ADS)

Effect of the ultrasound on flotation kinetics in reactor-separator has been studied for chalcopyrite/quartz mix mineral system. Under ultrasound treatment, recovery of chalcopyrite into bulk concentrate is higher than that at reagent-only treatment. It can be explained by increased of flotation rate for slow fraction as defined by Kelsall model. The slow fraction flotation rate increase multiplied by 6 vs. ultrasound treatment. Additional effect of the ultrasound treatment has been noticed under conditions when gangue minerals detachment from bubbles can be controlled. Reactor-separator has advantages over other types of flotation cells for this purpose providing a special zone for the ultrasound treatment that can be easily designed in this impeller less machine. The ultrasound influence on particles collision probability is able to explain of chalcopyrite recovery increase in the concentrate and activation chalcopyrite particles flotation.

Filippov, L. O.; Matinin, A. S.; Samiguin, V. D.; Filippova, I. V.

2013-03-01

402

Long term sealing ability of butyl o-rings  

SciTech Connect

This article reports on accelerated aging tests carried out to anticipate the long term performance of o-rings in the Galileo spacecraft during its mission to Jupiter. This topics discussed include the impetus for the investigation, the operating conditions for the o-rings, the conditions leading to degradation of performance of the o-rings, and a prediction of the ability of the o-rings to complete their intended mission.

Ytterboe, S.N.; Catsiff, E.H.; Kelchner, R.E.

1991-10-01

403

Biologically induced iron ore at Gunma iron mine, Japan  

Microsoft Academic Search

The mineralogy of sedimentary iron ores from the Gunma iron mine are described to evaluate the role of microorganisms and plants in ore formation. The iron ore is composed of nanocrystalline goethite, well-crystallized jarosite and very small amounts of strengite. The ore characteristically occurs as thick-bands of alternating goethite and jarosite bands, thin-bands of different goethite grain sizes, and fossil-aggregate

JUNJI AKAI; KURUMI AKAI; MAKOTO ITO; SATOSHI NAKANO; YONOSUKE MAKI; ICHIRO SASAGAWA

1999-01-01

404

Thermal investigations of direct iron ore reduction with coal  

Microsoft Academic Search

In this paper, fundamental mechanisms for iron ore reduction in coal–ore mixtures have been investigated using several advanced experimental techniques. Firstly, the thermal properties of coal–ore mixtures were studied and apparent specific heat of coal–ore mixtures against temperature was obtained at a heating rate of 10°C\\/min. Several exothermic and endothermic peaks were observed which were related to the decomposition reactions

Gui-su Liu; Vladimir Strezov; John A Lucas; Louis J Wibberley

2004-01-01

405

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

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

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

406

Estimation of photosynthesis and calcification rates at a fringing reef by accounting for diurnal variations and the zonation of coral reef communities on reef flat and slope: a case study for the Shiraho reef, Ishigaki Island, southwest Japan  

Microsoft Academic Search

Seven coral reef communities were defined on Shiraho fringing reef, Ishigaki Island, Japan. Net photosynthesis and calcification\\u000a rates were measured by in situ incubations at 10 sites that included six of the defined communities, and which occupied most\\u000a of the area on the reef flat and slope. Net photosynthesis on the reef flat was positive overall, but the reef flat

T. Nakamura; T. Nakamori

2009-01-01

407

A novel reef coral symbiosis  

NASA Astrophysics Data System (ADS)

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

Pantos, O.; Bythell, J. C.

2010-09-01

408

Micromorphology, chemistry, and mineralogy of bog iron ores from Poland  

Microsoft Academic Search

The influence of different land use history on the chemistry, mineralogy, and micromorphology of bog iron ores was studied in the vicinity of Warsaw, Poland. At three Holocene terraces of the Vistula River, eight profiles were chosen, which represent three different types of bog iron ore: (i) continuous hard layers (meadow, fallow at Wilanow), (ii) horizons with small ore fragments

Danuta Kaczorek; Michael Sommer

2003-01-01

409

Dissolution kinetics of smithsonite ore in ammonium chloride solution  

Microsoft Academic Search

The results of a dissolution kinetics study of smithsonite ore in ammonium chloride are presented. Effect of stirring speed, ore particle size, reaction temperature, and the concentration of ammonium chloride on zinc dissolution rate are determined. The results obtained show that leaching of about 91.2% of zinc is achieved using 84–110 ?m ore particle size at a reaction temperature of

Shaohua Ju; Tang Motang; Yang Shenghai; Li Yingnian

2005-01-01

410

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

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

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

411

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

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

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

412

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

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

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

413

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

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

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

414

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

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

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

415

MATHEMATICAL MODELLING AND OPTIMISATION OF IRON ORE SINTER PROPERTIES  

Microsoft Academic Search

The quality of iron ore sinter is a critical factor determining the productivity of blast furnaces for ironmaking. Csiro has therefore been developing capabilities for predicting sinter characteristics, which enables sinter quality to be improved\\/optimized and preliminary assessments to be made of the suitability of specific ores or ore blends for sinter production. An extensive database of pilot-scale sintering experimental

E. Donskoi; J. R. Manuel; J. M. F. Clout; Y. Zhang

416

In-plant testing of microbubble column flotation  

SciTech Connect

This report describes progress in two areas: advanced instrumentation and column installation. The project is working with both 30-inch and 8-foot columns for coal flotation. The paper describes installation of the instrument package, the control loops, and the data acquisition system. Under the second area of study, a test plan was developed for a parametric study of the 8-foot column operating conditions (feed flow rate, gas flow rate, wash water flow rate, and froth addition) that were determined to influence separation efficiency on the 30-inch column. Results to date are discussed. 7 refs., 4 tabs. (CK)

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

1990-01-01

417

Oil shales, evaporites and ore deposits  

Microsoft Academic Search

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

Hans P. Eugster

1985-01-01

418

Continuous Beneficiation of Dolomitic Phosphate Ores.  

National Technical Information Service (NTIS)

Over 80 pct of domestic phosphate rock, which is the starting material for phosphorus-containing fertilizers, comes from central Florida deposits. As higher grade deposits are depleted, lower grade phosphate ores containing MgO in the form of dolomite are...

B. E. Davis T. O. Llewellyn C. W. Smith

1984-01-01

419

PROCESS OF RECOVERING URANIUM FROM ITS ORES  

DOEpatents

A process is presented for recovering uranium from its ores. The crushed ore is mixed with 5 to 10% of sulfuric acid and added water to about 5 to 30% of the weight of the ore. This pugged material is cured for 2 to 3 hours at 100 to 110 deg C and then cooled. The cooled mass is nitrate-conditioned by mixing with a solution equivalent to 35 pounds of ammunium nitrate and 300 pounds of water per ton of ore. The resulting pulp containing 70% or more solids is treated by upflow percolation with a 5% solution of tributyl phosphate in kerosene at a rate equivalent to a residence time of about one hour to extract the solubilized uranium. The uranium is recovered from the pregnant organic liquid by counter-current washing with water. The organic extractant may be recycled. The uranium is removed from the water solution by treating with ammonia to precipitate ammonium diuranate. The filtrate from the last step may be recycled for the nitrate-conditioning treatment.

Galvanek, P. Jr.

1959-02-24

420

Metalliferous black shales and related ore deposits  

SciTech Connect

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

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

1990-01-01

421

Origins and development of Holocene coral reefs: a revisited model based on reef boreholes in the Seychelles, Indian Ocean  

Microsoft Academic Search

Until recently, concepts of coral reef growth and accumulation have been predominantly based on a Darwinian model. In this,\\u000a the upwards and outwards growth of a reef core (a coral framework) takes place over a foreslope consisting of reef talus,\\u000a with the simultaneous filling of the back-reef lagoon by reef-derived debris. The principal adaptations of this pattern relate\\u000a to the

C. J. R. Braithwaite; L. F. Montaggioni; G. F. Camoin; H. Dalmasso; W. C. Dullo; A. Mangini

2000-01-01

422

Coral-reef hydrology: field studies of water movement within a barrier reef  

NASA Astrophysics Data System (ADS)

Water movement through the framework of Davies Reef, a coral reef in the central Australian Great Barrier Reef, was studied using field and laboratory determinations of permeability, tide gauge measurements of water levels, dye tracers, and pore water chemistry. Flow is driven by current, wind-induced, or tide-induced water level differences which were shown to occur between reef front and lagoon. The reef is hydraulically very heterogeneous with bulk flow occurring through high permeability zones (voids and rubble) at a velocity on the order of 10 m/d. Pore water exchange in less permeable zones occurs at a much slower rate. Vertical components of flow are significant. Chemical data indicate that carbonate precipitation and solution occur so that porosities, permeabilities, and flow paths may change with time. Implications for nutrient transfer through the benthic sediments and for fresh water resources on reef islands are discussed.

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

1986-08-01

423

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

424

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

Microsoft Academic Search

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

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

2010-01-01

425

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

426

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

Microsoft Academic Search

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

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

2008-01-01

427

Ocean acidification accelerates reef bioerosion.  

PubMed

In the recent discussion how biotic systems may react to ocean acidification caused by the rapid rise in carbon dioxide partial pressure (pCO(2)) in the marine realm, substantial research is devoted to calcifiers such as stony corals. The antagonistic process - biologically induced carbonate dissolution via bioerosion - has largely been neglected. Unlike skeletal growth, we expect bioerosion by chemical means to be facilitated in a high-CO(2) world. This study focuses on one of the most detrimental bioeroders, the sponge Cliona orientalis, which attacks and kills live corals on Australia's Great Barrier Reef. Experimental exposure to lowered and elevated levels of pCO(2) confirms a significant enforcement of the sponges' bioerosion capacity with increasing pCO(2) under more acidic conditions. Considering the substantial contribution of sponges to carbonate bioerosion, this finding implies that tropical reef ecosystems are facing the combined effects of weakened coral calcification and accelerated bioerosion, resulting in critical pressure on the dynamic balance between biogenic carbonate build-up and degradation. PMID:23028797

Wisshak, Max; Schönberg, Christine H L; Form, Armin; Freiwald, André

2012-09-18

428

Coral Reef Adventure Fun Zone  

NSDL National Science Digital Library

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

Science NetLinks (AAAS;)

2007-04-29

429

Ocean Acidification Accelerates Reef Bioerosion  

PubMed Central

In the recent discussion how biotic systems may react to ocean acidification caused by the rapid rise in carbon dioxide partial pressure (pCO2) in the marine realm, substantial research is devoted to calcifiers such as stony corals. The antagonistic process – biologically induced carbonate dissolution via bioerosion – has largely been neglected. Unlike skeletal growth, we expect bioerosion by chemical means to be facilitated in a high-CO2 world. This study focuses on one of the most detrimental bioeroders, the sponge Cliona orientalis, which attacks and kills live corals on Australia’s Great Barrier Reef. Experimental exposure to lowered and elevated levels of pCO2 confirms a significant enforcement of the sponges’ bioerosion capacity with increasing pCO2 under more acidic conditions. Considering the substantial contribution of sponges to carbonate bioerosion, this finding implies that tropical reef ecosystems are facing the combined effects of weakened coral calcification and accelerated bioerosion, resulting in critical pressure on the dynamic balance between biogenic carbonate build-up and degradation.

Wisshak, Max; Schonberg, Christine H. L.; Form, Armin; Freiwald, Andre

2012-01-01

430

Numerical modeling of atoll reef harbors  

SciTech Connect

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 design of the harbor. The reef resulted in decreasing the wave height by a factor 3. The wave height at the shore can be further decreased by another factor of 2 by a ''V'' shaped or parabolic bottom design.

Mader, C.L.; Vitousek, M.; Lukas, S.

1986-01-01

431

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

432

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

NASA Astrophysics Data System (ADS)

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

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

2007-03-01

433

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

2013-05-31

434

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

SciTech Connect

The heart of the Pittsfield (Massachusetts) water-supply system is two potable flotation plants: Ashley Plant (2 Sandfloats) and Cleveland Plant (4 Sandfloats). Each sandfloat unit has a capacity of 6.25 MGD (million gallons per day). Sandfloat is a package clarifier consisting of flocculation, flotation, and filtration. Complete chronological testing of Pittsfield's two plants in the winter period, December 1986 through March 1987, is documented. The technical and economical feasibilities of Sandfloat are presented. Cleveland raw water having sufficient alkalinity and low temperature in winter was treated satisfactorily by Sandfloat at 6.25 MGD per unit using the chemical combination of sodium aluminate, polymer, and alum at a cost of $0.02458/1000 gal. At Ashley Plant, the mixture of 28% Ashley raw water and 72% Farnham raw water, having moderate alkalinity and low winter temperature was treated adequately by Sandfloat at 5.5-5.8 MGD per unit using the same chemicals. When 100% Farnham raw water with extremely low alkalinity and low pH was treated at Ashley Plant, PAC, sodium aluminate and polymer 1849A was found to be the best chemical combination for clarification.

Krofta, M.; Wang, L.K.

1987-09-20

435

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

NSDL National Science Digital Library

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

436

Three positive regulators of leaf senescence in Arabidopsis , ORE1, ORE3 and ORE9, play roles in crosstalk among multiple hormone-mediated senescence pathways  

Microsoft Academic Search

Leaf senescence is a developmentally programmed event, but the initiation and progression of leaf senescence are affected\\u000a by a range of plant hormones including abscisic acid (ABA), ethylene and methyl jasmonate (MeJA). To investigate plant hormone\\u000a crosstalk during leaf senescence, hormone-induced senescence phenotypes were analyzed in three leaf senescence mutants [ore1 (oresara1), ore3 and ore9] showing delayed senescence phenotypes in

Jin Hee Kim; Kyung Min Chung; Hye Ryun Woo

2011-01-01

437

Coral reefs of the Mascarenes, Western Indian Ocean.  

PubMed

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

Turner, John; Klaus, Rebecca

2005-01-15

438

Extraction process and apparatus for hydrocarbon containing ores  

SciTech Connect

There is provided a hydrocarbon extraction process and apparatus for removing hydrocarbons from a hydrocarbon containing ore such as a diatomite ore. The ore is preprocessed to the extent required to produce an extractable ore and subsequently mixed with a carrier to form an ore stream. The carrier may be a nonaqueous solvent and may further comprise a non-porous granular material such as sand. The ore stream is passed in substantially vertical countercurrent flow through a nonaqueous solvent to produce a product-solvent stream and a spent ore stream. The solvent is subsequently separated from the hydrocarbon stream, which may be further upgraded by removal of a heavy portion. This may be accomplished in the presence of a substantial amount of fines.

Friedman, R. H.; Eakin, B. E.

1985-09-03

439

DETAIL VIEW OF LOWER TRAM TERMINAL, SECONDARY ORE BIN, CRUSHER ...  

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

DETAIL VIEW OF LOWER TRAM TERMINAL, SECONDARY ORE BIN, CRUSHER FOUNDATION, AND BALL MILL FOUNDATIONS, LOOKING NORTH NORTHWEST. ORE FROM THE MINES WAS DUMPED FROM THE TRAM BUCKETS INTO THE PRIMARY ORE BIN UNDER THE TRAM TERMINAL. A SLIDING CONTROL DOOR INTRODUCED THE INTO THE JAW CRUSHER (FOUNDATIONS,CENTER). THE CRUSHED ORE WAS THEN CONVEYED INTO THE SECONDARY ORE BIN AT CENTER LEFT. A HOLE IN THE FLOOR OF THE ORE BIN PASSED ORE ONTO ANOTHER CONVEYOR THAT BROUGHT IT OUT TO THE BALL MILL(FOUNDATIONS,CENTER BOTTOM). THIS SYSTEM IS MOST LIKELY NOT THE ORIGINAL SET UP, PROBABLY INSTALLED IN THE MINE'S LAST OCCUPATION IN THE EARLY 1940s. - Keane Wonder Mine, Park Route 4 (Daylight Pass Cutoff), Death Valley Junction, Inyo County, CA

440

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

2012-04-13

441

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...

442

Climate Change: Effects on Reef Island Resources.  

National Technical Information Service (NTIS)

The salinity, depth, quantity, and reliability of fresh groundwater resources on coral reef islands and coastlines are environmentally important parameters. Groundwater influences or controls the terrestrial flora, salinity, and nutrient levels in the nea...

J. A. Oberdorfer R. W. Buddemeier

1988-01-01

443

Extinction vulnerability of coral reef fishes  

PubMed Central

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

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

2011-01-01

444

Oysters and Oyster Reef Communities in Florida.  

ERIC Educational Resources Information Center

The habitat, life history, feeding, classification, anatomy and pearl production of the American oyster (Crassostrea virginica) are presented. A list of other oyster reef inhabitants and predators is provided. Harvest and habitat loss are discussed. (CW)

Knight, Jean; Bly, Joe

1989-01-01

445

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

NASA Astrophysics Data System (ADS)

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

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

1993-10-01

446

Kinetic model for conventional flotation of coal. Report of investigations/1995  

SciTech Connect

The U.S. Bureau of Mines has developed a computer model to describe a flotation process. Coal data from conventional flotation has been converted to a simple two-parameter kinetic model developed by Reuter and van Deventer. Each set of coal data was represented by two constants, alpha and beta, and an average flotation rate. The success of the model was demonstrated when the calculated and experimental recoveries showed good correlation. The two-parameter model allows complex data to be defined much more efficiently than traditional knowledge-based models.

Susko, F.J.; Stanley, D.A.

1995-12-31

447

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

448

Mass Spawning in Tropical Reef Corals  

NASA Astrophysics Data System (ADS)

Synchronous multispecific spawning by a total of 32 coral species occurred a few nights after late spring full moons in 1981 and 1982 at three locations on the Great Barrier Reef, Australia. The data invalidate the generalization that most corals have internally fertilized, brooded planula larvae. In every species observed, gametes were released; external fertilization and development then followed. The developmental rates of externally fertilized eggs and longevities of planulae indicate that planulae may be dispersed between reefs.

Harrison, Peter L.; Babcock, Russell C.; Bull, Gordon D.; Oliver, James K.; Wallace, Carden C.; Willis, Bette L.

1984-03-01

449

Relationships between coral reef substrata and fish  

Microsoft Academic Search

.  ?The objective of this work is to identify which substrata characteristics (such as coral morphology, coral diversity, coral\\u000a species richness, percentage coverage by live coral or by algae) influence the structure and abundance of fish communities.\\u000a The study was carried out at Reunion Island, Indian Ocean, where six sites were sampled in two zones (reef flat and outer\\u000a reef slope).

P. Chabanet; H. Ralambondrainy; M. Amanieu; G. Faure; R. Galzin

1997-01-01

450

Shallow pore water sampling in reef sediments  

Microsoft Academic Search

Several new techniques have been developed to allow the geochemical characterization of shallow pore waters in reefs. First,\\u000a a new method was developed for using non-metallic well-points to sample pore waters from shallow depths (<1?m) in coral reefs\\u000a with unconsolidated substrates. These PVC well-points can be made faster and at less expense than well-points made of stainless\\u000a steel. They also

J. L. Falter; F. J. Sansone

2000-01-01

451

Macroalgal blooms on southeast Florida coral reefs  

Microsoft Academic Search

Abstract Invasive bloomsof the siphonaceous greenalgae Codiumspp. have been considered a symptom ofcoastal eutrophicationbut, to date, only limitedbiochemical evidence supports a linkage to land-based nutrient pollution. Beginningin the summer of 1990, spectacular blooms,of unattached Codium isthmocladum,developed on deep coral reef habitats in southern Palm Beach County and northern Broward County, and in subsequent years, attached populations formed on reefs in

Brian E. Lapointe; Peter J. Barile; Mark M. Littler; Diane S. Littler; Bradley J. Bedford; Constance Gasque

452

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

453

Coral reefs and the World Bank.  

PubMed

The World Bank¿s involvement in coral reef conservation is part of a larger effort to promote the sound management of coastal and marine resources. This involves three major thrusts: partnerships, investments, networks and knowledge. As an initial partner and early supporter of the International Coral Reef Initiative (ICRI), the Bank serves as the executive planning committee of ICRI. In partnership with the World Conservation Union and the Great Barrier Reef Marine Park Authority, the Bank promotes the efforts towards the establishment and maintenance of a globally representative system of marine protected areas. In addition, the Bank invested over $120 million in coral reef rehabilitation and protection programs in several countries. Furthermore, the Bank developed a ¿Knowledge Bank¿ that would market ideas and knowledge to its clients along with investment projects. This aimed to put the best global knowledge on environmentally sustainable development in the hands of its staff and clients. During the celebration of 1997, as the International Year of the Reef, the Bank planned to cosponsor an associated event that would highlight the significance of coral reefs and encourage immediate action to halt their degradation to conserve this unique ecosystem. PMID:12295815

Hatziolos, M

1997-01-01

454

Infrared analysis of refined uranium ore  

Microsoft Academic Search

Infrared assay of refined uranium ore (yellowcake) is described and the results are related to worker protection measures. Eleven standard mixtures of ammonium diuranate and UâOâ were prepared that contained 0% ammonium diuranate (pure UâOâ) through 100% ammonium diuranate (no UâOâ) in 10% intervals. Assay of these mixtures (0.30% in KBr) showed that ammonium diuranate could be accurately assayed within

Arthur F. Eidson

1985-01-01

455

Preparation of magnesite ore in mining  

Microsoft Academic Search

It is shown that the chemical composition of the mined magnesite ore is interrelated with its lumpiness. It is established\\u000a that the content of harmful admixtures in fine fractions exceeds that in coarse fractions by a factor of 2–3. The discovered\\u000a dependences have been used in a series of full-scale tests that reflect the main laws of segregation of the

A. V. Gal’yanov; Yu. V. Laptev; M. N. Kovalev; A. I. Vladimirov

2000-01-01

456

Pressure leaching las cruces copper ore  

NASA Astrophysics Data System (ADS)

A hydrometallurgical process was developed for treating the Las Cruces massive sulfide-ore deposit located near Seville, Spain. A two-stage countercurrent leach process, consisting of an atmospheric leach and a pressure leach, was developed to effectively leach copper from the copper-bearing minerals and to generate a solution suitable for the subsequent solvent-extraction and copper-electrowinning operations. The results of batch and continuous miniplant tests are presented.

Berezowsky, R. M.; Xue, T.; Collins, M. J.; Makwana, M.; Barton-Jones, I.; Southgate, M.; Maclean, J. K.

1999-12-01

457

New anticorrosive coating compositions incorporated ilmenite ore  

Microsoft Academic Search

Objective of the research relates to corrosion-resistant coating capable of being lied to various substrates, particularly metal surfaces, as a single coat characterized as having high-gloss, good adhesion and a high degree of flexibility. Long oil alkyds were first modified with naphthalene dicarboxylic acid and then introduced in primer formulations containing an effective amount of corrosion-resisting pigment ilmenite ore. The

H. Abd El-Wahab; M. Abd EL-Fattah; M. I. Abdou; F. Abd El-Hai

2009-01-01

458

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

Microsoft Academic Search

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

Alan T White; Helge P Vogt; Tijen Arin

2000-01-01

459

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

460

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

Microsoft Academic Search

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

James E. Maragos; Paul L. Jokiel

1986-01-01

461

U.S. CORAL REEF TASK FORCE CORAL REEFS AND CLIMATE INITIATIVE (NOAA, DOI)  

EPA Science Inventory

In October 2002, the U.S. Coral Reef Task Force passed two resolutions highlighting the impacts of climate change and coral bleaching on coral reefs and calling for an interagency, public/private partnership to advance understanding and management of this issue. In response, the ...

462

Coal Waste Artificial Reef Program: Reef Measurements Over Four Years in the Sea.  

National Technical Information Service (NTIS)

In September 1980, a fishing reef was constructed off the shore of Long Island, southeast of the Fire Island Inlet. The reef consisted of 15,000 blocks made from coal waste materials. The report documents the conclusions of a four-year project that monito...

P. M. J. Woodhead

1987-01-01

463

Iron ore weathering potentials of ectomycorrhizal plants.  

PubMed

Plants in association with soil microorganisms play an important role in mineral weathering. Studies have shown that plants in symbiosis with ectomycorrhizal (ECM) fungi have the potential to increase the uptake of mineral-derived nutrients. However, it is usually difficult to study many of the different factors that influence ectomycorrhizal weathering in a single experiment. In the present study, we carried out a pot experiment where Pinus patula seedlings were grown with or without ECM fungi in the presence of iron ore minerals. The ECM fungi used included Pisolithus tinctorius, Paxillus involutus, Laccaria bicolor and Suillus tomentosus. After 24 weeks, harvesting of the plants was carried out. The concentration of organic acids released into the soil, as well as potassium and phosphorus released from the iron ore were measured. The results suggest that different roles of ectomycorrhizal fungi in mineral weathering such as nutrient absorption and transfer, improving the health of plants and ensuring nutrient circulation in the ecosystem, are species specific, and both mycorrhizal roots and non-mycorrhizal roots can participate in the weathering process of iron ore minerals. PMID:22349958

Adeleke, R A; Cloete, T E; Bertrand, A; Khasa, D P

2012-02-21

464

Soundscapes from a Tropical Eastern Pacific reef and a Caribbean Sea reef  

NASA Astrophysics Data System (ADS)

Underwater soundscapes vary due to the abiotic and biological components of the habitat. We quantitatively characterized the acoustic environments of two coral reef habitats, one in the Tropical Eastern Pacific (Panama) and one in the Caribbean (Florida Keys), over 2-day recording durations in July 2011. We examined the frequency distribution, temporal variability, and biological patterns of sound production and found clear differences. The Pacific reef exhibited clear biological patterns and high temporal variability, such as the onset of snapping shrimp noise at night, as well as a 400-Hz daytime band likely produced by damselfish. In contrast, the Caribbean reef had high sound levels in the lowest frequencies, but lacked clear temporal patterns. We suggest that acoustic measures are an important element to include in reef monitoring programs, as the acoustic environment plays an important role in the ecology of reef organisms at multiple life-history stages.

Staaterman, E.; Rice, A. N.; Mann, D. A.; Paris, C. B.

2013-06-01

465

Physical-chemical conditions of ore deposition  

USGS Publications Warehouse

Ore deposits form under a wide range of physical and chemical conditions, but those precipitating from hot, aqueous fluids-i.e. the hydrothermal deposits-form generally below 700??C and at pressures of only 1 or 2 kbar or less. Natural aqueous fluids in rocks may extract metal and sulfur from a variety of rock types or may acquire them as a residual heritage from a crystallizing silicate magma. Ore-forming hydrothermal fluids never appear as hot springs (except in deep, submarine situations) because they boil, mix with surface waters, and cool, thereby losing their ore-bearing ability before reaching the surface. Mineral systems function as chemical buffers and indicators just as buffers and indicators function in a chemical laboratory. By reading the record written in the buffer/indicator assemblages of minerals one can reconstruct many aspects of the former chemical environment. By studying the record of changing conditions one may deduce information regarding the processes functioning to create the succession of chemical environments and the ore deposits they represent. The example of the OH vein at Creede, Colorado, shows a pH buffered by the K-feldspar + muscovite + quartz assemblage and the covariation of S2 and O2 buffered by the assemblage chlorite + pyrite + quartz. Boiling of the ore fluid led to its oxidation to hematite-bearing assemblages and simultaneously produced an intensely altered, sericitic capping over the vein in response to the condensation of vapors bearing acidic components. The solubility of metals as calculated from experimental and theoretical studies of mineral solubility appears too low by at least one or two powers of ten to explain the mineralization at Creede. In contrast to Creede where the mineral stabilities all point to a relatively consistent chemistry, the Mississippi Valley type deposits present a puzzle of conflicting chemical clues that are impossible to reconcile with any single equilibrium situation. Thus we must seriously consider metastable equilibria; those most likely involve redox disequilibrium among the sulfur species in solution and perhaps also involve organic compounds. ?? 1981.

Barton, Jr. , P. B.

1981-01-01

466

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

PubMed Central

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

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

2013-01-01

467

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

Code of Federal Regulations, 2010 CFR

...percent impervious to water and fuel. Styrofoam floatation must be fully encased...flotation upon notification from TVA. For any float installed after September 8, 2003...from docks, boathouses, houseboats, floats, and other water-use structures...

2010-04-01

468

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

Code of Federal Regulations, 2010 CFR

...percent impervious to water and fuel. Styrofoam floatation must be fully encased...flotation upon notification from TVA. For any float installed after September 8, 2003...from docks, boathouses, houseboats, floats, and other water-use structures...

2009-04-01

469

Selective flotation of fossil resin from western coal. Quarterly report, December 1, 1990-February 28, 1991.  

National Technical Information Service (NTIS)

Research continued flotation of resin from coal. This quarter laboratory research at the University of Utah was concerned with surface chemistry/resin characterization and the development of analytical techniques. APT's activities included plant construct...

1991-01-01

470

Effect of Surfactant Micelles on Metal Ion Removal by Flotation from Metallurgical Wastewater.  

National Technical Information Service (NTIS)

The study is a fundamental laboratory investigation of events occurring on a molecular scale that influence the process of ion flotation. To accomplish these objectives critical micelle concentrations and micellar molecular weights have been determined fo...

R. L. Venable U. M. Oko

1971-01-01

471

Simulation Study of Self-Tuning Adaptive Control for Rougher Flotation.  

National Technical Information Service (NTIS)

The properties of different self-tuning algorithms are studied and evaluated with the help of a phenomenological dynamic simulator of the flotation process. The problem of controlling a system with constant but unknown parameters is considered. In the beg...

S. W. Jaemsae-Jounela

1990-01-01

472

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...

473

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

474

Level Flotation Standards Analysis Research and Development Report. Phase II - Special Problems.  

National Technical Information Service (NTIS)

The objective of the study reported herein was to provide information that would assist in finalizing a level flotation standard. This report provides data that will be useful in defining longitudinal and transverse limits for test weight placement for co...

C. Sautkulis

1975-01-01

475

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

PubMed Central

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

Coruh, Semra; Elevli, Sermin; Geyikci, Feza

2012-01-01

476

Personal Flotation Devices Research. Volume 1. Executive Summary and Proposed Technical Approach.  

National Technical Information Service (NTIS)

Research on the development of a comprehensive system for evaluating the life-saving capability of Personal Flotation Devices (PFDs) is reported. The approach contained herein evaluates PFDs on the basis of a probabilistic equation called the Life-Saving ...

T. Doll M. Pfauth J. Gleason S. Cohen C. Stiehl

1978-01-01

477

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

Code of Federal Regulations, 2013 CFR

...flotation device or material specifically designed for marine applications (for example, pontoons, boat hulls, or other buoyancy devices made of steel, aluminum, fiberglass, or plastic foam, as provided for in paragraph (a) of this section)....

2013-04-01

478

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

479

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

480

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

Code of Federal Regulations, 2013 CFR

...SECURITY (CONTINUED) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Flotation Requirements for Outboard Boats Rated for Engines of More Than 2 Horsepower...and (d) through (h) are met, the boat must float in fresh, calm water as...

2013-07-01

481

An investigation of variables in a fecal flotation technique.  

PubMed

Several variables in a standard vial fecal gravitational flotation technique were investigated. These were the specific gravity of the sodium nitrate flotation solution, duration of flotation and mesh sizes of strainers. The number of eggs which floated and adhered to a coverslip were counted and estimates of the number of eggs remaining in the strained fecal suspension and in the feces trapped on the strainer were made. Eggs from hookworms, Trichuris vulpis and Toxocara canis in feces from dogs, Nematodirus spp. from sheep and Parascaris equorum from horses floated equally well in solutions with specific gravities (SpGr) ranging from 1.22-1.38. Taenia spp. from dogs had a slightly narrower range (SpGr 1.27-1.38) for best recovery. Eggs from Haemonchus contortus from sheep appeared to float best between SpGr 1.22- 1.32. Strongyles from one horse floated best with SpGr 1.27-1.32 and from another with SpGr 1.11-1.38. Coccidial oocysts from sheep floated best in a narrow range of SpGr from 1.22-1.27. However, as the SpGr of the solution was increased the recognition of eggs under the coverslip was increasingly difficult and especially so at SpGr 1.38 with sheep feces. This was due to the increasing amount of debris and the more rapid formation of crystals with evaporation with solutions of higher SpGr. It appeared, therefore, that solutions with SpGr of 1.22-1.35 would be best for routine laboratory use. At specific gravity 1.27, there appeared to be no difference in the number of eggs recovered for a four, eight and 12 min flotation period. Only 3-7% of the eggs in 4 g of feces were counted under the coverslip. This poor efficacy resulted first because approximately 50% of the eggs were trapped in the feces and retained on the strainer. Secondly, only one half of the strained fecal suspension, containing approximately 25% of the eggs, was placed in the vial for examination. Thirdly, of those eggs in the vial only 16-29% were counted under the coverslip. When the second half of the strained fecal suspension was placed in another vial, the amount of debris and air bubbles adhering to the coverslip was much less than that for the first vial. Egg counts for both vials appeared similar and it may be that when debris is excessive the fecal examination should involve counts from a second vial. The use of strainers finer than the standard tea strainer and the addition of minimal amounts of detergent did not increase the egg count. PMID:7190861

O'Grady, M R; Slocombe, J O

1980-04-01

482

Froth flotation of oil-bearing metal sulfide wastes  

SciTech Connect

An industrial wastewater, including plating wastes, is treated with sodium sulfide and ferrous sulfate to form a sulfide-oxide precipitate containing chromium and other toxic metals. Hydrocarbons, in the water, coat the sulfide-oxide particles, impeding metal recovery. Froth flotation, without reagent addition, was found to recover 93.9% of the solids from the sludge with simultaneous rejection of 89% of the water. Methyl isobutyl carbinol (MIBC) improved recovery and potassium amyl xanthate improved both recovery and grade. The process design has wastewater feed (without MIBC) to the rougher circuit. The rougher concentrate is conditioned with MIBC and fed to a cleaner circuit to achieve a high grade concentrate. About 95% of the water is recirculated to the waste treatment plant. 3 refs., 3 figs., 4 tabs.

Miller, R.L. (Idaho National Engineering Lab., Idaho Falls, ID (United States)); Atwood, R.L.; Ye, Yi (Advanced Processing Technologies, Inc., Salt Lake City, UT (United States))

1991-01-01

483

Froth flotation of oil-bearing metal sulfide wastes  

SciTech Connect

An industrial wastewater, including plating wastes, is treated with sodium sulfide and ferrous sulfate to form a sulfide-oxide precipitate containing chromium and other toxic metals. Hydrocarbons, in the water, coat the sulfide-oxide particles, impeding metal recovery. Froth flotation, without reagent addition, was found to recover 93.9% of the solids from the sludge with simultaneous rejection of 89% of the water. Methyl isobutyl carbinol (MIBC) improved recovery and potassium amyl xanthate improved both recovery and grade. The process design has wastewater feed (without MIBC) to the rougher circuit. The rougher concentrate is conditioned with MIBC and fed to a cleaner circuit to achieve a high grade concentrate. About 95% of the water is recirculated to the waste treatment plant. 3 refs., 3 figs., 4 tabs.

Miller, R.L. [Idaho National Engineering Lab., Idaho Falls, ID (United States); Atwood, R.L.; Ye, Yi [Advanced Processing Technologies, Inc., Salt Lake City, UT (United States)

1991-12-01

484

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

485

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

486

Mineralogical characterization of silver flotation concentrates made from zinc neutral leach residues  

Microsoft Academic Search

Silver flotation concentrates prepared from high-silver (1480 ppm Ag) and low-silver (300 ppm Ag) neutral leach residues have\\u000a been examined mineralogically to determine the phases present and to elucidate the behavior of silver during zinc processing.\\u000a The flotation concentrates consist principally of sphalerite although lesser amounts of zinc ferrite and PbSO4, as well as traces of other phases, also are

T. T. Chen; J. E. Dutrizac

1988-01-01

487

Dimensionless Analysis of Process Variables in Air-Sparged Hydrocyclone ( ASH ) Flotation of Fine Coal  

Microsoft Academic Search

Fine coal cleaning by froth flotation in a 2-inch air-sparged hydrocyclone (ASH) has been investigated and the effects of important design and operating variables on separation efficiency examined. In order to reduce the complexity of the analysis, the flotation performance of the air-sparged hydrocyclone was studied by dimensionless analysis. As a result of these efforts, an empirical model was derived

S. GOPALAKRISHNAN; Y. YE; J. D. MILLER

1991-01-01

488

Estimation of flotation kinetic parameters by considering interactions of the operating variables  

Microsoft Academic Search

In this study, the classical first-order kinetic model was combined with a properly built statistical model based on a factorial experimental design, in order to accurately predict the rougher flotation efficiency for various flotation conditions. A three-level, three-factor experimental design was used to develop a statistical model to predict each of the kinetic model parameters as a function of the

E. C. Çilek

2004-01-01

489

The role of surfactants and polymers in the filler flotation from waste paper  

Microsoft Academic Search

High contents of fillers such as kaolin or calcium carbonate limit the use of waste paper, especially in tissue paper production.\\u000a In order to determine the effect of flotation reagents on the removal of fillers, adsorption, zeta potential, and particle\\u000a size measurement,s as well as flotation experiments using model dispersions of calcium carbonate, kaolin, and cellulose fibers\\u000a were carried out.

M. Liphard; W. von Rybinski; B. Schreck

490

Treatment of oil-in-water emulsions by coagulation and dissolved-air flotation  

Microsoft Academic Search

The treatment of oil-in-water emulsions containing n-octane (used as simulated wastewater) was investigated by means of dissolved-air flotation jar-tests. The effect of several parameters on flotation efficiency for separation of the emulsified oil was examined, namely, (a) the presence the nonionic surfactant Tween 80, used for the stabilization of the emulsions, (b) the initial pH value of the emulsions, (c)

A. I Zouboulis; A Avranas

2000-01-01

491

Cleaning of Coal Using an Integrated Grinding-Flotation Column System  

Microsoft Academic Search

Improved pyritic sulfur and ash reduction was obtained by using an advanced column flotation system that integrates grinding and flotation operations in a single stage. The column was tested with Illinois No. 6 coal (minus 60 mesh) containing 36.6% ash and 3.5% total sulfur, out of which pyritic sulfur accounted for 2.03%. Using designed experiments, a bilinear response surface was

MOHAN MUNIRATHINAM; J. G. GROPPO; B. K. PAREKH; J. C. YINGLING

1995-01-01

492

Coralline reefs classification in Banco Chinchorro, Mexico  

NASA Astrophysics Data System (ADS)

The coralline reefs in Banco Chinchorro, Mexico, are part of the great reef belt of the western Atlantic. This reef complex is formed by an extensive coralline structure with great biological richness and diversity of species. These colonies are considered highly valuable ecologically, economically, socially and culturally, and they also inherently provide biological services. Fishing and scuba diving have been the main economic activities in this area for decades. However, in recent years, there has been a bleaching process and a decrease of the coral colonies in Quintana Roo, Mexico. This drop is caused mainly by the production activities performed in the oil platforms and the presence of hurricanes among other climatic events. The deterioration of the reef system can be analyzed synoptically using remote sensing. Thanks to this type of analysis, it is possible to have updated information of the reef conditions. In this paper, satellite imagery in Landsat TM and SPOT 5 is applied in the coralline reefs classification in the 1980- 2006 time period. Thus, an integral analysis of the optical components of the water surrounding the coralline reefs, such as on phytoplankton, sediments, yellow substance and even on the same water adjacent to the coral colonies, is performed. The use of a texture algorithm (Markov Random Field) was a key tool for their identification. This algorithm, does not limit itself to image segmentation, but also works on edge detection. In future work the multitemporal analysis of the results will determine the deterioration degree of these habitats and the conservation status of the coralline areas.

Contreras-Silva, Ameris I.; López-Caloca, Alejandra A.

2009-09-01

493

Upper Carboniferous reef mounds and climate change  

SciTech Connect

Tetractinomorph demosponges (chaetetids) are a minor component of extant tropical reefs, but they were the major framebuilder of reef mounds during the Westphalian (Carboniferous). These chaetetids were confined to tropical latitudes during the Carboniferous, reached an abundance peak in the Westphalian, and then declined suddenly until the Upper Triassic. After their decline, red and green algae became the dominant reef builders of the Stephanian. The marked decline of chaetetids corresponds with the disappearance, and/or decline of other marine benthic invertebrates, as well as some terrestrial plants and is the basis for the biostratigraphic boundary between the Westphalian and Stephanian (Desmoinesian and Missourian). This biostratigraphic boundary coincides with a minor extinction event and a major'' climatic change. The Westphalian climate was wetter than that of the Stephanian, and in the midcontinent this change is recorded by a gradual decline in coals and siliciclastic lithologies and a corresponding increase in carbonate lithologies. A rise in water temperature might be expected in a drier tropical climate, and if extant chaetetids are any clue, elevated water temperature may have been detrimental. Extant chaetetids are associated with tropical coral reefs that are confined to a narrow temperature range. It is not unreasonable to suggest that elevated seawater temperatures were responsible, in part, for the disappearance of chaetetid reef mounds. Red and green algae, presumably more tolerate of higher water temperatures, became the major framebuilders of reef mounds in the Stephanian. Thus, the demise of chaetetid reef mounds, and other organisms at the end of the Westphalian, may be the result of global warming.

West, R.R.; Archer, A.W. (Kansas State Univ., Manhattan, KS (United States))

1992-01-01

494

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

495

Devonian Winnipegosis reefs of Manitoba outcrop belt - possible basin model  

SciTech Connect

Devonian Winnipegosis reefs crop out intermittently along a 350-km belt in southwestern Manitoba and represent an almost complete facies sequence ranging from central-basin reefs in the northwest to shelf-edge reefs in the southeast. In addition, structural complexities of the overlying Devonian strata mirror precisely the configuration of the underlying reefs. These outcrop data, supplemented by closely spaced stratigraphic core holes that have been sited specifically with respect to reef-controlled structures, permit development of a tentative reef model. Reef parameters are (a) size, from less than 0.5 km to a maximum of about 12 km; (b) shape, small pinnacle-type features to broad, irregular, flat-topped, atoll-like complexes, all with relatively steep margins (5/degrees/-20/degrees/); and (c) height, uniform in any given area, ranging from 40-50 m at shelf edge to 65-90 m in central basin areas. Internal reef structure shows flat central beds, and flank dips ranging from 20/degrees/ to 45/degrees/ or more in the most basinward reefs. Locally, reefs are abundantly fossiliferous, but organic framework is difficult to identify. Black bituminous mudstones in the interreef and reef-flank areas, with or without reef-derived carbonate detritus, are the only time-stratigraphic equivalents of the reefs. (The Ratner-type bituminous carbonate laminites appear to entirely postdate reef development.) Configuration of the steep-sided reefs and the well-defined shelf edge may have been controlled not only by organic (biohermal.) development, but also by anoxic containment resulting from restriction of lateral growth by anoxic bottom waters. Pinnacle reefs could thus have developed, in part, as anoxically contained pinnacle mounds rather than true bioherms.

McCabe, H.R.

1988-07-01

496

Oceanography and reefs of recent and Paleozoic tropical epeiric seas  

Microsoft Academic Search

Summary  The Java Sea, one of the few modern tropical epeiric seas, is used as an analogue to examine oceanography, stratigraphy, and\\u000a reefs of Devonian strata in the Appalachian and Michigan Basins. Nearshore patch reefs and offshore “pinnacle” reefs occur\\u000a in both the Java Sea and the Emsian-Eifelian Onondaga Formation in the Appalachian Basin. Nearshore patch reefs also occur\\u000a in the

Evan N. Edinger; St. Paul Copper; Michael J. Risk; Warsito Atmojo

2002-01-01

497

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

498

The Merensky Reef in the Chineisky Pluton (Siberia)? A myth or a reality?  

NASA Astrophysics Data System (ADS)

It is a dream of each geologist to find a `Merensky Reef' in each layered basic intrusion. Scientists have been trying many various techniques to come this dream to reality. The most perspective way to do so is probably a combination of physicochemical and computer modeling of layered basic intrusion crystallization together with fluid and melt inclusions studies in situ. This combination allows us to do the following: 1. To study boundary conditions for separation of low density gas phase and salt melt from the crystallizing primary basic melt in large magma chamber. 2. To determine correct quantitative parameters for formation of residual fluid-bearing brines extracting high metal concentrations. 3. To compute critical levels for substance differentiation at phase, geochemical and other `barriers' in those basic mantle-crust ore magmatic systems. 4. To model metal extraction, transportation and deposition at these `barriers' for systems of various `silicate melt - residual salt brines' ratios under the conditions of continental lithosphere. Comparison of real and modeled data allows us to conclude if a formation of a narrow zone of high metal concentration is possible at those critical levels (phase and geochemical `barriers'). The above-mentioned algorithm has been used for the Chineisky Pluton (the Transbaikal region, Siberia). Fortunately we have found our own `Merensky Reef', which happened to be a PGE enrichment marginal zone of the Chineisky Pluton due to specific fluid regime of crystallization! This work was supported by the Ministry for Russian Science and Education, Grant #DSP.2.1.1.702.

Zhitova, L.; Sharapov, V.; Zhukova, I.

2006-12-01

499

Recovery of fine coal from waste streams using advanced column flotation  

SciTech Connect

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

Groppo, J.G.

1991-01-01

500

OVERVIEW OF UPPER TRAM TERMINAL, TRAM TRESTLE, AND PRIMARY ORE ...  

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

OVERVIEW OF UPPER TRAM TERMINAL, TRAM TRESTLE, AND PRIMARY ORE BIN, LOOKING NORTHEAST. REMAINS OF A BLACKSMITH'S FORGE AND WORK CAN BE SEEN JUST BELOW THE ORE BIN (SEE CA-291-32 FOR DETAIL). ROCK FOUNDATIONS LOCATED JUST ABOVE THE ORE BIN AND ALONG THE FIRST RIDGELINE ARE TENT PADS. SEE CA-291-24 FOR IDENTICAL B&W NEGATIVE. - Keane Wonder Mine, Park Route 4 (Daylight Pass Cutoff), Death Valley Junction, Inyo County, CA