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1

Metal, mineral waste processing and secondary recovery  

SciTech Connect

Approximately 40 million tons of precious metals chemical wastes are produced in the United States every year. An estimated five percent of these wastes are being reused/recycled to recover the precious and critical metals they contain. The rest of these chemical wastes are disposed of by the methods incineration, dumping at sea and dumping on land. In this paper, an attempt is made to review the research work published during 1985-1986 on metal, mineral waste processing, secondary recovery and safe disposal.

Reddy, R.G.

1987-04-01

2

Weathering and Secondary Minerals in the Martian Meteorite Shergotty  

NASA Technical Reports Server (NTRS)

The Shergotty martian meteorite contains weathering features and secondary minerals much like those in Nakhla, including secondary silicates, NaCl, and Ca-sulfate. It is likely that the weathering occurred on Mars.

Wentworth, Susan J.; Thomas-Keprta, Kathie L.; McKay, David S.

2000-01-01

3

Secondary Iron Mineral Formation by Shewanellae Using Different Carbon Sources  

NASA Astrophysics Data System (ADS)

It has been known for some time that microbes play an important role in the redox cycling of iron. A considerable amount of work has been done investigating the various factors that play a role in solid phase iron reduction such as the type of iron oxide available for reduction, medium composition, surface area and ferrous iron concentration. However, the rate at which a single cell reduces iron oxides and the impact of dissimilatory iron reduction kinetics on mineral speciation are not well understood. In order to determine the relationship between iron oxide reduction rates and secondary mineral formation, we have tested 4 different strains of Shewanella with different carbon sources. Strains MR-1, MR-4, CN32 and W3-18-1 were incubated with HFO (hydrous ferric oxide) as electron acceptor and either lactate, pyruvate, isoleucine or uridine as the organic carbon source. Mineral products were analyzed using X-ray diffraction, electron microscopy and Mossbauer spectroscopy. Initial results suggest that reduction rates are similar among strains when using the same carbon source. However, qualitative assessment of mineral products suggests that while reduction rates for the tested strains may be similar, the secondary mineral products can be quite different.

Salas, E. C.; Kukkadapu, R. K.; Fredrickson, J. K.; Nealson, K. H.

2007-12-01

4

Low temperature CO2 mineralization into basalt: solution chemistry and secondary mineral assemblages  

NASA Astrophysics Data System (ADS)

CO2 represents one of the most abundant acid supplies in nature and has an important impact on element fluxes and water chemistry on the Earth surface. CO2 emissions due to increased industrialization are causing an important imbalance in this surface system and affect the global climate. Therefore, different methods to trap CO2 are developed and studied in response to the CO2 increase. CO2 sequestration into secondary minerals is considered as one possible way of reducing those CO2 levels. The Carbfix project is a pilot study in SW Iceland aiming to inject CO2-loaded waters from the Hellisheidi geothermal powerplant into basaltic rock formations. The goal is to mineralize CO2 by reacting Ca+2, Mg+2 and Fe+2 ions released by the basalt into carbonates. We investigated the geochemical aspects of CO2-water-basalt interaction at pCO2 between 0-20 bar and temperatures of 25-40°C by combining experiments and numerical modelling. The aim of our studies are to gain a better understanding of the key reactions, mass fluxes and porosity changes associated to CO2-water-basalt interaction. Modelling results show that at low reaction progress (pH <7), the main secondary mineral assemblages formed by reacting CO2- water-basalt are amorphous SiO2, Fe-Mg carbonates, Al-silicates and Fe-hydroxides, whereas at high reaction progress (pH >8) the main stable minerals precipitating from solution are (Ca)-Mg-Fe clays, Ca-Mg carbonates and zeolites (Gysi and Stéfansson 2008). Laboratory experiments were performed by reacting basaltic glass with aqueous solutions initially saturated at pCO2 ranging between 0-10 bar at 40°C for 120 days. Results from solution chemistry show that there are three different element mobility behaviors: i) Si+4 and Al+3 dissolve non-stochiometrically and/or precipitate into secondary minerals independent of the intial pCO2 and the water/rock ratios used in the experiments, b) Ca+2 and Mg+2 dissolve stochiometrically independent of the initial pCO2, but precipitate into secondary minerals at high water/rock ratios and low initial pCO2 after about 100 days, c) elements like Fe show a mixed behavior from mobile to immobile depending on the solution pH and their oxidation state. Secondary mineral assemblages were identified using SEM, and WDS elemental maps combined with quantitative analysis on EMPA. In all experiments, secondary minerals precipitating from solution were (Ca)-(Mg)-Fe-rich carbonates, amorphous Fe-hydroxides and (Na)-Ca-Mg-Fe clays. Our model compare qualitatively well with the experiments, the key factors controlling CO2 mineralization into carbonates beeing competing reactions between clays and carbonates for Ca+2, Mg+2 and Fe+2 ions.

Gysi, A.; Stefánsson, A.

2009-12-01

5

Origin of secondary sulfate minerals on active andesitic stratovolcanoes  

USGS Publications Warehouse

Sulfate minerals in altered rocks on the upper flanks and summits of active andesitic stratovolcanoes result from multiple processes. The origin of these sulfates at five active volcanoes, Citlalte??petl (Mexico), and Mount Adams, Hood, Rainier, and Shasta (Cascade Range, USA), was investigated using field observations, petrography, mineralogy, chemical modeling, and stable-isotope data. The four general groups of sulfate minerals identified are: (1) alunite group, (2) jarosite group, (3) readily soluble Fe- and Al-hydroxysulfates, and (4) simple alkaline-earth sulfates such as anhydrite, gypsum, and barite. Generalized assemblages of spatially associated secondary minerals were recognized: (1) alunite+silica??pyrite??kaolinite?? gypsum??sulfur, (2) jarosite+alunite+silica; (3) jarosite+smectite+silica??pyrite, (4) Fe- and Al-hydroxysulfates+silica, and (5) simple sulfates+silica??Al-hydroxysulfates??alunite. Isotopic data verify that all sulfate and sulfide minerals and their associated alteration assemblages result largely from the introduction of sulfur-bearing magmatic gases into meteoric water in the upper levels of the volcanoes. The sulfur and oxygen isotopic data for all minerals indicate the general mixing of aqueous sulfate derived from deep (largely disproportionation of SO2 in magmatic vapor) and shallow (oxidation of pyrite or H2S) sources. The hydrogen and oxygen isotopic data of alunite indicate the mixing of magmatic and meteoric fluids. Some alunite-group minerals, along with kaolinite, formed from sulfuric acid created by the disproportionation of SO2 in a condensing magmatic vapor. Such alunite, observed only in those volcanoes whose interiors are exposed by erosion or edifice collapse, may have ??34S values that reflect equilibrium (350??50 ??C) between aqueous sulfate and H2S. Alunite with ??34S values indicating disequilibrium between parent aqueous sulfate and H2S may form from aqueous sulfate created in higher level low-temperature environments in which SO2 is scrubbed out by groundwater or where H2S is oxidized. Jarosite-group minerals associated with smectite in only slightly altered volcanic rock are formed largely from aqueous sulfate derived from supergene oxidation of hydrothermal pyrite above the water table. Soluble Al- and Fehydroxysulfates form in low-pH surface environments, especially around fumaroles, and from the oxidation of hydrothermal pyrite. Anhydrite/gypsum, often associated with native sulfur and occasionally with small amounts of barite, also commonly form around fumaroles. Some occurrences of anhydrite/gypsum may be secondary, derived from the dissolution and reprecipitation of soluble sulfate. Edifice collapse may also reveal deep veins of anhydrite/gypsum??barite that formed from the mixing of saline fluids with magmatic sulfate and dilute meteoric water. Alteration along structures associated with both hydrothermal and supergene sulfates, as well as the position of paleo-water tables, may be important factors in edifice collapse and resulting debris flows at some volcanoes. ?? 2004 Elsevier B.V. All rights reserved.

Zimbelman, D.R.; Rye, R.O.; Breit, G.N.

2005-01-01

6

Formation of secondary minerals in a lysimeter approach - A mineral-microbe interaction  

NASA Astrophysics Data System (ADS)

Heavy metal contamination of large areas due to uranium mining operations poses a serious long-term environmental problem. In the Ronneburg district (eastern Thuringia, Germany), leaching of low grade uranium bearing ores (uranium content < 300 g/t) occurred from 1972 to 1990 using acid mine drainage (AMD; pH 2.7-2.8) and diluted sulphuric acid (10 g/l). Secondary mineral phases like birnessite, todorokite and goethite occur within a natural attenuation process associated with enrichment of heavy metals, especially Cd, Ni, Co, Cu and Zn due to a residual contamination even after remediation efforts. To reveal the processes of secondary mineral precipitation in the field a laboratory lysimeter approach was set up under in situ-like conditions. Homogenized soil from the field site and pure quartz sand were used as substrates. In general, in situ measurements of redox potentials in the substrates showed highly oxidizing conditions (200-750 mV). Water was supplied to the lysimeter from below via a mariottés bottle containing contaminated groundwater from the field. Evaporation processes were allowed, providing a continuous flow of water. This led to precipitation of epsomite and probably aplowite on the top layer of substrate, similar to what is observed in field investigations. After 4 weeks, the first iron and manganese bearing secondary minerals became visible. Soil water samples were used to monitor the behaviour of metals within the lysimeter. Saturation indices (SI) for different secondary minerals were calculated with PHREEQC. The SI of goethite showed oversaturation with respect to the soil solution. SEM-EDX analyses and IR spectroscopy confirmed the formation of goethite. Geochemical data revealed that goethite formation was mainly dominated by Eh/pH processes and that heavy metals, e.g. Zn and U, could be enriched in this phase. Although Eh/pH data does not support formation of manganese minerals, Mn(II)-oxidizing bacteria (MOB) could be isolated from field soil samples, supporting the fact that microorganisms may influence this natural attenuation process. Laser ablation ICP-MS data reveal accumulation of manganese in MOB biomass on Mn(II)-containing agar plates. Furthermore, it was possible to show the importance of iron on this process, as some MOB isolates were able to oxidize manganese independently from the iron content, whereas some are not. The latter isolates are only able to oxidize manganese if iron is present in the media. In the lysimeter, SEM-EDX data showed microorganisms in organic rich phases together with the occurrence of manganese, oxygen, and nickel, indicating manganese oxides enriched in nickel. Although this new mineral phases could not yet be identified microprobe EDX results from polished thin sections showed needle-like mineral structures that are similar to the birnessite and todorokite samples observed from field samples. Hence, the lysimeter experiment revealed that the formation of iron and manganese minerals that are involved in heavy metal natural attenuation is result of both abiotic and biotic processes.

Schäffner, F.; Merten, D.; De Giudici, G.; Beyer, A.; Akob, D. M.; Ricci, P. C.; Küsel, K.; Büchel, G.

2012-04-01

7

Origin, timing, and temperature of secondary calcite–silica mineral formation at Yucca Mountain, Nevada  

Microsoft Academic Search

The origin of secondary calcite–silica minerals in primary and secondary porosity of the host Miocene tuffs at Yucca Mountain has been hotly debated during the last decade. Proponents of a high-level nuclear waste repository beneath Yucca Mountain have interpreted the secondary minerals to have formed from cool, descending meteoric fluids in the vadose zone; critics, citing the presence of two-phase

Nicholas S. F Wilson; Jean S Cline; Yuri V Amelin

2003-01-01

8

Microtextured Silicon Surfaces for Detectors, Sensors & Photovoltaics  

SciTech Connect

With support from this award we studied a novel silicon microtexturing process and its application in silicon-based infrared photodetectors. By irradiating the surface of a silicon wafer with intense femtosecond laser pulses in the presence of certain gases or liquids, the originally shiny, flat surface is transformed into a dark array of microstructures. The resulting microtextured surface has near-unity absorption from near-ultraviolet to infrared wavelengths well below the band gap. The high, broad absorption of microtextured silicon could enable the production of silicon-based photodiodes for use as inexpensive, room-temperature multi-spectral photodetectors. Such detectors would find use in numerous applications including environmental sensors, solar energy, and infrared imaging. The goals of this study were to learn about microtextured surfaces and then develop and test prototype silicon detectors for the visible and infrared. We were extremely successful in achieving our goals. During the first two years of this award, we learned a great deal about how microtextured surfaces form and what leads to their remarkable optical properties. We used this knowledge to build prototype detectors with high sensitivity in both the visible and in the near-infrared. We obtained room-temperature responsivities as high as 100 A/W at 1064 nm, two orders of magnitude higher than standard silicon photodiodes. For wavelengths below the band gap, we obtained responsivities as high as 50 mA/W at 1330 nm and 35 mA/W at 1550 nm, close to the responsivity of InGaAs photodiodes and five orders of magnitude higher than silicon devices in this wavelength region.

Carey, JE; Mazur, E

2005-05-19

9

Oxygen Isotopes and Geothermometry of Secondary Minerals in CR Chondrites  

NASA Astrophysics Data System (ADS)

We report oxygen isotopes measured from secondary calcite and magnetite in QUE 99177, a weakly altered CR chondrite, and discuss implications for temperature and fluid chemistry during aqueous alteration on the CR parent body.

Jilly, C. E.; Huss, G. R.; Nagashima, K.; Schrader, D. L.

2014-09-01

10

Secondary phosphate mineralization in a karstic environment in Central Sri Lanka  

NASA Astrophysics Data System (ADS)

At Eppawala in central Sri Lanka secondary phosphate mineralization is intimately associated with laminated fabrics within depressions (sinkholes and smaller cavities) formed in the thick weathering profiles of a hilly terrain underlain by a Precambrian apatite-bearing formation. The lowermost levels of the profile show extensive zones of leaching where derived apatite crystals occur within fine-grained, laminated stromatolite sequences. The stromatolitic groundmass, which diagenetically formed by percolating oxygenated phosphate and carbonate-rich groundwaters, is impregnated by the phosphate minerals francolite and collophane. Scanning electron microscopy (SEM) reveals that fine filaments, characteristic of microorganisms, are associated with the secondary phosphate mineralization. Continuous degradation and fragmentation of the stromatolitic mat has produced pellets, peloids, and intraclasts all enriched in secondary apatite. Degrading recrystallization around the edges of the primary apatite crystals has developed coated grains. The widespread occurrence of phosphate-enriched allochems in stromatolitic groundmasses is a unique development of a modern phosphorite in a karstic environment.

Dahanayake, Kapila; Subasinghe, S. M. N. D.

1989-07-01

11

Boundaries of intergrowths between mineral individuals: A zone of secondary mineral formation in aggregates  

NASA Astrophysics Data System (ADS)

Intergrowth boundaries between mineral individuals in dunite of the Gal’moenan massif in Koryakia was studied in terms of crystal morphology, crystal optics, and ontogenesis. The results obtained allowed us to trace the staged formation of olivine and chromite and four generations of these minerals. Micro-and nanotopography of boundary surfaces between intergrown mineral individuals of different generations was examined with optic, electron, and atomic force microscopes. The boundaries between mineral individuals of different generations are distinguished by their microsculpture for both olivine and chromite grains. Both minerals demonstrate a compositional trend toward refinement from older to younger generations. The decrease in the iron mole fraction in olivine and chromite is accompanied by the crystallization of magnetite along weakened zones in olivine of the first generation and as outer rims around the chromite grains of the second generation observable under optic and electronic microscopes. The subsequent refinement of chromite results in the release of PGE from its lattice, as established by atomic power microscopy. The newly formed PGM are localized at the boundaries between mineral individuals and, thus, mark a special stage in the ontogenetic evolution of mineral aggregates. Further recrystallization is expressed in the spatial redistribution of grain boundaries and the formation of monomineralic intergrowth boundaries, i.e., the glomerogranular structure of rock and substructures of PGM, chromite, and olivine grains as intermediate types of organization of the granular assemblies in the form of reticulate, chain, and cellular structures and substructures of aggregates.

Brodskaya, R. L.; Bil'Skaya, I. V.; Lyakhnitskaya, V. D.; Markovsky, B. A.; Sidorov, E. G.

2007-12-01

12

Secondary Fe–Mn-oxides in minerals heavily damaged by ?-recoil: possible implications for palaeomagnetism  

Microsoft Academic Search

Sub-micron Fe,Mn-oxides in columbite–tantalite minerals are bound to metamict domains in the host. These nano-oxides are secondary\\u000a minerals as the metamict zones formed through accumulation of damages from ?-recoil, each of which in a small volume destroys\\u000a the crystal lattice of the U and Th bearing columbite–tantalite host. Transmission electron microscope investigations demonstrate\\u000a that the oxides fall in the compositional

Rolf L. Romer; Norbert Nowaczyk; Richard Wirth

2007-01-01

13

Microbial Composition in Decomposing Pine Litter Shifts in Response to Common Soil Secondary Minerals  

NASA Astrophysics Data System (ADS)

A range of environmental and biotic factors have been identified that drive microbial community structure in soils - carbon substrates, redox conditions, mineral nutrients, salinity, pH, and species interactions. However, soil mineralogy has been largely ignored as a candidate in spite of recent studies that indicate that minerals have a substantial impact on soil organic matter stores and subsequent fluxes from soils. Given that secondary minerals and organic colloids govern a soil's biogeochemical activity due to surface area and electromagnetic charge, we propose that secondary minerals are a strong determinant of the communities that are responsible for process rates. To test this, we created three microcosms to study communities during decomposition using pine forest litter mixed with two common secondary minerals in soils (goethite and gibbsite) and with quartz as a control. Changes in bacterial and fungal communities were tracked over the 154-day incubation by pyrosequencing fragments of the bacterial 16S and fungal 18S rRNA genes. Ordination using nonmetric multidimensional scaling showed that bacterial communities separated on the basis of minerals. Overall, a single generalist - identified as an Acidobacteriaceae isolate - dominated all treatments over the course of the experiment, representing roughly 25% of all communities. Fungal communities discriminated between the quartz control alone and mineral treatments as a whole. Again, several generalists dominated the community. Coniochaeta ligniaria dominated communities with abundances ranging from 29 to 40%. The general stability of generalist populations may explain the similarities between treatment respiration rates. Variation between molecular fingerprints, then, were largely a function of unique minor members with abundances ranging from 0.01 to 8%. Carbon availability did not surface as a possible mechanism responsible for shifts in fingerprints due to the relatively large mass of needles in the incubation. Other possible mechanisms include the presence of soluble Fe as an alternative energy source in the goethite treatment, the presence of toxic soluble Al in the gibbsite treatment, the loss of available phosphorus in the secondary mineral treatments due to sorption by secondary mineral surfaces, and variations in mineral surfaces as microhabitats. These findings suggest that Al and Fe oxides, such as goethite or gibbsite, are a factor in determining microbial community structure.

Welty-Bernard, A. T.; Heckman, K.; Vazquez, A.; Rasmussen, C.; Chorover, J.; Schwartz, E.

2011-12-01

14

Weathering features and secondary minerals in Antarctic Shergottites ALHA77005 and LEW88516  

NASA Technical Reports Server (NTRS)

Previous work has shown that all three sub-groups of the shergottite, nakhlite, and chassignite (SNC) clan of meteorites contain aqueous precipitates of probable pre-terrestrial origin. In the context of secondary minerals, the most thoroughly studied shergottite has been Elephant Moraine, Antarctica A79001 (EETA79001). The recognition of LEW88516 as the latest SNC specimen, and its close similarity with ALHA77005, invite a comparative study of the latter two meteorites, and with EETA79001, from the perspective of aqueous alteration. The fusion crusts of the two meteorites are quite similar except that ALHA77005 is more vesicular (possibly indicating a higher indigenous volatile content). Secondary aluminosilicates (and salts on LEW88516) of definite Antarctic origin partially fill vesicles and fractures on both fusion crusts. Interior samples of the two meteorites are grossly similar in that traces of secondary minerals are present in both.

Wentworth, Susan J.; Gooding, James L.

1993-01-01

15

Method of making a coating of a microtextured surface  

DOEpatents

A method for conformally coating a microtextured surface. The method includes flash evaporating a polymer precursor forming an evaporate, passing the evaporate to a glow discharge electrode creating a glow discharge polymer precursor plasma from the evaporate, cryocondensing the glow discharge polymer precursor plasma on the microtextured surface and crosslinking the glow discharge polymer precursor plasma thereon, wherein the crosslinking resulting from radicals created in the glow discharge polymer precursor plasma.

Affinito, John D [Tucson, AZ; Graff, Gordon L [West Richland, WA; Martin, Peter M [Kennewick, WA; Gross, Mark E [Pasco, WA; Burrows, Paul E [Kennewick, WA; Sapochak, Linda S [Henderson, NV

2004-11-02

16

Mineral dissolution and secondary precipitation on quartz sand in simulated Hanford tank solutions affecting subsurface porosity  

NASA Astrophysics Data System (ADS)

Highly alkaline nuclear waste solutions have been released from underground nuclear waste storage tanks and pipelines into the vadose zone at the US Department of Energy's Hanford Site in Washington, causing mineral dissolution and re-precipitation upon contact with subsurface sediments. High pH caustic NaNO3 solutions with and without dissolved Al were reacted with quartz sand through flow-through columns stepwise at 45, 51, and 89 °C to simulate possible reactions between leaked nuclear waste solution and primary subsurface mineral. Upon reaction, Si was released from the dissolution of quartz sand, and nitrate-cancrinite [Na8Si6Al6O24(NO3)2] precipitated on the quartz surface as a secondary mineral phase. Both steady-state dissolution and precipitation kinetics were quantified, and quartz dissolution apparent activation energy was determined. Mineral alteration through dissolution and precipitation processes results in pore volume and structure changes in the subsurface porous media. In this study, the column porosity increased up to 40.3% in the pure dissolution column when no dissolved Al was present in the leachate, whereas up to a 26.5% porosity decrease was found in columns where both dissolution and precipitation were observed because of the presence of Al in the input solution. The porosity change was also confirmed by calculation using the dissolution and precipitation rates and mineral volume changes.

Wang, Guohui; Um, Wooyong

2012-11-01

17

Mineral Dissolution and Secondary Precipitation on Quartz Sand in Simulated Hanford Tank Solutions Affecting Subsurface Porosity  

SciTech Connect

Highly alkaline nuclear waste solutions have been released from underground nuclear waste storage tanks and pipelines into the vadose zone at the U.S. Department of Energy’s Hanford Site in Washington, causing mineral dissolution and re-precipitation upon contact with subsurface sediments. High pH caustic NaNO3 solutions with and without dissolved Al were reacted with quartz sand through flow-through columns stepwise at 45, 51, and 89°C to simulate possible reactions between leaked nuclear waste solution and primary subsurface mineral. Upon reaction, Si was released from the dissolution of quartz sand, and nitrate-cancrinite [Na8Si6Al6O24(NO3)2] precipitated on the quartz surface as a secondary mineral phase. Both steady-state dissolution and precipitation kinetics were quantified, and quartz dissolution apparent activation energy was determined. Mineral alteration through dissolution and precipitation processes results in pore volume and structure changes in the subsurface porous media. In this study, the column porosity increased up to 40.3% in the pure dissolution column when no dissolved Al was present in the leachate, whereas up to a 26.5% porosity decrease was found in columns where both dissolution and precipitation were observed because of the presence of Al in the input solution. The porosity change was also confirmed by calculation using the dissolution and precipitation rates and mineral volume changes.

Wang, Guohui; Um, Wooyong

2012-11-23

18

Electrically conducting superhydrophobic microtextured carbon nanotube nanocomposite  

NASA Astrophysics Data System (ADS)

We report a simple and inexpensive method of producing an electrically conductive superhydrophobic polymer surface by adding multiwall carbon nanotubes directly into the polymer poly(dimethylsiloxane) (PDMS) matrix and replicating micro/nanotexture using a replication master prepared by ultrafast-laser microtexturing process. No additional coatings on conducting PDMS are required to achieve water contact angles greater than 161°. The conductivity can be controlled by changing the percent MWCNT added to PDMS and at a bulk loading of 4.4 wt% we report a conductivity improvement over pure PDMS by a factor of more than 1011 with electrical resistivity ? = 761 ? cm. This combined behavior of a conductive, superhydrophobic nanocomposite has exciting applications for allowing a new class of enclosures providing EMI shielding, water repellency and sensing to provide built-in temperature feedback. The effect of temperature on the nanocomposite was investigated and a negative temperature coefficient of resistance (-0.037 ?/K) similar to that of a thermistor was observed.

Caffrey, Paul O.; Gupta, Mool C.

2014-09-01

19

Lava cave microbial communities within mats and secondary mineral deposits: implications for life detection on other planets.  

PubMed

Lava caves contain a wealth of yellow, white, pink, tan, and gold-colored microbial mats; but in addition to these clearly biological mats, there are many secondary mineral deposits that are nonbiological in appearance. Secondary mineral deposits examined include an amorphous copper-silicate deposit (Hawai'i) that is blue-green in color and contains reticulated and fuzzy filament morphologies. In the Azores, lava tubes contain iron-oxide formations, a soft ooze-like coating, and pink hexagons on basaltic glass, while gold-colored deposits are found in lava caves in New Mexico and Hawai'i. A combination of scanning electron microscopy (SEM) and molecular techniques was used to analyze these communities. Molecular analyses of the microbial mats and secondary mineral deposits revealed a community that contains 14 phyla of bacteria across three locations: the Azores, New Mexico, and Hawai'i. Similarities exist between bacterial phyla found in microbial mats and secondary minerals, but marked differences also occur, such as the lack of Actinobacteria in two-thirds of the secondary mineral deposits. The discovery that such deposits contain abundant life can help guide our detection of life on extraterrestrial bodies. PMID:21879833

Northup, D E; Melim, L A; Spilde, M N; Hathaway, J J M; Garcia, M G; Moya, M; Stone, F D; Boston, P J; Dapkevicius, M L N E; Riquelme, C

2011-09-01

20

Lava Cave Microbial Communities Within Mats and Secondary Mineral Deposits: Implications for Life Detection on Other Planets  

PubMed Central

Abstract Lava caves contain a wealth of yellow, white, pink, tan, and gold-colored microbial mats; but in addition to these clearly biological mats, there are many secondary mineral deposits that are nonbiological in appearance. Secondary mineral deposits examined include an amorphous copper-silicate deposit (Hawai‘i) that is blue-green in color and contains reticulated and fuzzy filament morphologies. In the Azores, lava tubes contain iron-oxide formations, a soft ooze-like coating, and pink hexagons on basaltic glass, while gold-colored deposits are found in lava caves in New Mexico and Hawai‘i. A combination of scanning electron microscopy (SEM) and molecular techniques was used to analyze these communities. Molecular analyses of the microbial mats and secondary mineral deposits revealed a community that contains 14 phyla of bacteria across three locations: the Azores, New Mexico, and Hawai‘i. Similarities exist between bacterial phyla found in microbial mats and secondary minerals, but marked differences also occur, such as the lack of Actinobacteria in two-thirds of the secondary mineral deposits. The discovery that such deposits contain abundant life can help guide our detection of life on extraterrestrial bodies. Key Words: Biosignatures—Astrobiology—Bacteria—Caves—Life detection—Microbial mats. Astrobiology 11, 601–618. PMID:21879833

Melim, L.A.; Spilde, M.N.; Hathaway, J.J.M.; Garcia, M.G.; Moya, M.; Stone, F.D.; Boston, P.J.; Dapkevicius, M.L.N.E.; Riquelme, C.

2011-01-01

21

Secondary Sulfate Mineralization and Basaltic Chemistry of Craters of the Moon National Monument, Idaho: Potential Martian Analog  

SciTech Connect

Secondary deposits associated with the basaltic caves of Craters of the Moon National Monument (COM) in southern Idaho were examined using X-ray powder diffraction, X-ray fluorescence spectrometry, Fourier transform infrared spectrometry, and Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS). The secondary mineral assemblages are dominated by Na-sulfate minerals (thenardite, mirabilite) with a small fraction of the deposits containing minor concentrations of Na-carbonate minerals. The assemblages are found as white, efflorescent deposits in small cavities along the cave walls and ceilings and as localized mounds on the cave floors. Formation of the deposits is likely due to direct and indirect physiochemical leaching of meteoritic water through the overlying basalts. Whole rock data from the overlying basaltic flows are characterized by their extremely high iron concentrations, making them good analogs for martian basalts. Understanding the physiochemical pathways leading to secondary mineralization at COM is also important because lava tubes and basaltic caves are present on Mars. The ability of FTICR-MS to consistently and accurately identify mineral species within these heterogeneous mineral assemblages proves its validity as a valuable technique for the direct fingerprinting of mineral species by deductive reasoning or by comparison with reference spectra.

C. Doc Richardson; Nancy W. Hinman; Lindsay J. McHenry; J. Michelle Kotler; Jill R. Scott

2012-05-01

22

Mutual replacement reactions in alkali feldspars I: microtextures and mechanisms  

Microsoft Academic Search

Intracrystal microtextures formed by a process of mutual replacement in alkali feldspars record fluid–rock reactions that\\u000a have affected large volumes of the Earth’s crust. Regular, ?1 ?m-scale ‘strain-controlled’ perthitic microtextures coarsen,\\u000a by up to 103, by a dissolution–reprecipitation process, producing microporous patch or vein perthites on scales >100 ?m. We have developed\\u000a earlier studies of such reactions in alkali feldspar cm-scale primocrysts

Ian Parsons; Martin R. Lee

2009-01-01

23

Evidence for an unsaturated-zone origin of secondary minerals in Yucca Mountain, Nevada  

SciTech Connect

The unsaturated zone (UZ) in Miocene-age welded tuffs at Yucca Mountain, Nevada, is under consideration as a potential site for the construction of a high-level radioactive waste repository. Secondary calcite and silica minerals deposited on fractures and in cavities in the UZ tuffs are texturally, isotopically, and geochemically consistent with UZ deposition from meteoric water infiltrating at the surface and percolating through the UZ along fractures. Nonetheless, two-phase fluid inclusions with small and consistent vapor to liquid (V:L) ratios that yield consistent temperatures within samples and which range from about 35 to about 80 C between samples have led some to attribute these deposits to formation from upwelling hydrothermal waters. Geochronologic studies have shown that calcite and silica minerals began forming at least 10 Ma and continued to form into the Holocene. If their deposition were really from upwelling water flooding the UZ, it would draw into question the suitability of the site as a waste repository.

Whelan, Joseph F.; Roedder, Edwin; Paces, James B.

2001-04-29

24

Minerals salt composition and secondary metabolites of Euphorbia hirta Linn., an antihyperglycemic plant  

PubMed Central

Phytochemical study and research on acute toxicity were performed on the aerial parts (leaves and stems) of Euphorbia hirta Linn. The phytochemical screening and chromatography revealed the presence of saponin, sterol, terpene, alkaloids, polyphenols, tannins and flavonoids and especially mucilage. The evaluation of total polyphenols and total flavonoids gave 120.97 ± 7.07 gallic acid equivalents (GAE) mg/g (mg of GAE/g of extract) of dry extract and 41.4 ± 0.5 mg quercetin equivalent per gram (QE/g) (mg of QE/g of plant extract) of dry extract respectively. The physicochemical study revealed moisture content of 7.73% ± 0.00%, total ash 7.48% ± 0.03%. Sulfuric ash 9.05% ± 0.01%, hydrochloric acid insoluble ash of 0.8% ± 0.02%. The search for minerals salt revealed the presence of Cr, Zn, K, Ca and Mg having an important role in glucose metabolism. The acute toxicity study showed that the toxic dose may be above 3000 mg/kg. The results of these studies indicate that extracts from the leaves and stem of E. hirta Linn. contains trace elements and minerals salt and bioactive secondary metabolites which explain their therapeutic uses for treating diabetes mellitus. PMID:25598628

Yvette Fofie, N’Guessan Bra; Sanogo, Rokia; Coulibaly, Kiyinlma; Kone-Bamba, Diénéba

2015-01-01

25

Minerals salt composition and secondary metabolites of Euphorbia hirta Linn., an antihyperglycemic plant.  

PubMed

Phytochemical study and research on acute toxicity were performed on the aerial parts (leaves and stems) of Euphorbia hirta Linn. The phytochemical screening and chromatography revealed the presence of saponin, sterol, terpene, alkaloids, polyphenols, tannins and flavonoids and especially mucilage. The evaluation of total polyphenols and total flavonoids gave 120.97 ± 7.07 gallic acid equivalents (GAE) mg/g (mg of GAE/g of extract) of dry extract and 41.4 ± 0.5 mg quercetin equivalent per gram (QE/g) (mg of QE/g of plant extract) of dry extract respectively. The physicochemical study revealed moisture content of 7.73% ± 0.00%, total ash 7.48% ± 0.03%. Sulfuric ash 9.05% ± 0.01%, hydrochloric acid insoluble ash of 0.8% ± 0.02%. The search for minerals salt revealed the presence of Cr, Zn, K, Ca and Mg having an important role in glucose metabolism. The acute toxicity study showed that the toxic dose may be above 3000 mg/kg. The results of these studies indicate that extracts from the leaves and stem of E. hirta Linn. contains trace elements and minerals salt and bioactive secondary metabolites which explain their therapeutic uses for treating diabetes mellitus. PMID:25598628

Yvette Fofie, N'Guessan Bra; Sanogo, Rokia; Coulibaly, Kiyinlma; Kone-Bamba, Diénéba

2015-01-01

26

Radioelements and their occurrence with secondary minerals in heated and unheated tuff at the Nevada Test Site  

Microsoft Academic Search

Samples of devitrified welded tuff near and away from the site of a heater test in Rainier Mesa were examined with regard to whole-rock radioelement abundances, microscopic distribution of U, and oxygen isotope ratios. Wholerock U averages between 4 and 5 ppM, and U is concentrated at higher levels secondary opaque minerals as well as in accessory grains. U in

S. Flexser; H. A. Wollenberg

1992-01-01

27

9 M.y. record of southern Nevada climate from Yucca Mountain secondary minerals  

SciTech Connect

Yucca Mountain, Nevada, is presently the object of intense study as a potential permanent repository for the Nation`s high-level radioactive wastes. The mountain consists of a thick sequence of volcanic tuffs within which the depth to water table ranges from 500 to 700 meters below the land surface. This thick unsaturated zone (UZ), which would host the projected repository, coupled with the present day arid to semi-arid climate, is considered a favorable attribute of the site. Evaluation of the site includes defining the relation between climate variability, as the input function or driver of site- and regional-scale ground-water flow, and the possible future transport and release of radionuclides to the accessible environment. Secondary calcite and opal have been deposited in the UZ by meteoric waters that infiltrated through overlying soils and percolated through the tuffs. The oxygen isotopic composition ({delta}{sup 18}O values) of these minerals reflect contemporaneous meteoric waters and the {delta}{sup 13}C values reflect soil organic matter, and hence the resident plant community, at the time of infiltration. Recent U/Pb age determinations of opal in these occurrences, coupled with the {delta}{sup 13}C values of associated calcite, allow broadbrush reconstructions of climate patterns during the past 9 M.y.

Whelan, J.F.; Moscati, R.J.

1998-12-01

28

Volcanic stratigraphy and secondary mineralization of U. S. G. S. Pucci geothermal test well, Mount Hood, Oregon  

SciTech Connect

Ninety-one sample splits of drill cuttings from approximately 6.1 m intervals in the 610 m hole that was completed in 1979 were provided for this study. An additional 225 sample splits (3.05 m intervals) from 536 m to the bottom of the drill hole at 1220 m were added to the study following the deepening of the drill hole. Stratigraphic and petrologic observations of the cuttings were made. Scanning electron microscope and x-ray diffractometer examinations were made of alteration minerals. The lithology and secondary mineralization are discussed.

Gannett, M.W.; Bargar, K.E.

1981-01-01

29

Feldspar microtextures and multistage thermal history of syenites from the Coldwell Complex, Ontario  

Microsoft Academic Search

Optical and TEM (transmission electron microscopy) observations of perthites from augite syenites in the Coldwell Complex (Ontario) reveal a complex set of microtextures that outline a multistage thermal history. Regular microtextures (linear or braid texture, straincontrolled, coherent intergrowths) show a progressive evolution from the margin of the intrusion inwards with lamellar spacings in the range 40–100 nm. The textures evolve

Kim A. Waldron; Ian Parsons

1992-01-01

30

Spectroscopic vibrations of austinite (CaZnAsO4?OH) and its mineral structure: implications for identification of secondary arsenic-containing mineral.  

PubMed

Austinite (CaZnAsO4?OH) is a unique secondary mineral in arsenic-contaminated mine wastes. The infrared and Raman spectroscopies were used to characterize the austenite vibrations. The IR bands at 369, 790 and 416 cm(-1) are assigned to the ?2, ?3 and ?4 vibrations of AsO4(3-) unit, respectively. The Raman bands at 814, 779 and 403 cm(-1) correspond to the ?1, ?3 and ?4 vibrations of AsO4(3(-) unit respectively. The sharp bands at 3265 cm(-1) for IR and 3270 cm(-(1) both reveals that the structural hydroxyl units exist in the austenite structure. The IR and Raman spectra both show that some SO4 units isomorphically replace AsO4 in austinite. X-ray single crystal diffraction provides the arrangement of each atom in the mineral structure, and also confirms that the conclusions made from the vibrational spectra. Micro-powder diffraction was used to confirm our mineral identification due to the small quantity of the austenite crystals. PMID:25087167

Liu, Jing; Ming, Dengshi; Cheng, Hongfei; Xu, Zhiqiang; Frost, Ray L

2015-01-25

31

Spectroscopic vibrations of austinite (CaZnAsO4?OH) and its mineral structure: Implications for identification of secondary arsenic-containing mineral  

NASA Astrophysics Data System (ADS)

Austinite (CaZnAsO4?OH) is a unique secondary mineral in arsenic-contaminated mine wastes. The infrared and Raman spectroscopies were used to characterize the austenite vibrations. The IR bands at 369, 790 and 416 cm-1 are assigned to the ?2, ?3 and ?4 vibrations of AsO43- unit, respectively. The Raman bands at 814, 779 and 403 cm-1 correspond to the ?1, ?3 and ?4 vibrations of AsO43- unit respectively. The sharp bands at 3265 cm-1 for IR and 3270 cm-1 both reveals that the structural hydroxyl units exist in the austenite structure. The IR and Raman spectra both show that some SO4 units isomorphically replace AsO4 in austinite. X-ray single crystal diffraction provides the arrangement of each atom in the mineral structure, and also confirms that the conclusions made from the vibrational spectra. Micro-powder diffraction was used to confirm our mineral identification due to the small quantity of the austenite crystals.

Liu, Jing; Ming, Dengshi; Cheng, Hongfei; Xu, Zhiqiang; Frost, Ray L.

2015-01-01

32

Coupled alkai fieldspar dissolution and secondary mineral precipatation in batch systems-2: New experiments with supercritical CO2 and implications for carbon sequestration  

SciTech Connect

In order to evaluate the extent of CO{sub 2}–water–rock interactions in geological formations for C sequestration, three batch experiments were conducted on alkali feldspars–CO{sub 2}–brine interactions at 150–200 °C and 300 bars. The elevated temperatures were necessary to accelerate the reactions to facilitate attainable laboratory measurements. Temporal evolution of fluid chemistry was monitored by major element analysis of in situ fluid samples. SEM, TEM and XRD analysis of reaction products showed extensive dissolution features (etch pits, channels, kinks and steps) on feldspars and precipitation of secondary minerals (boehmite, kaolinite, muscovite and paragonite) on feldspar surfaces. Therefore, these experiments have generated both solution chemistry and secondary mineral identity. The experimental results show that partial equilibrium was not attained between secondary minerals and aqueous solutions for the feldspar hydrolysis batch systems. Evidence came from both solution chemistry (supersaturation of the secondary minerals during the entire experimental duration) and metastable co-existence of secondary minerals. The slow precipitation of secondary minerals results in a negative feedback in the dissolution–precipitation loop, reducing the overall feldspar dissolution rates by orders of magnitude. Furthermore, the experimental data indicate the form of rate laws greatly influence the steady state rates under which feldspar dissolution took place. Negligence of both the mitigating effects of secondary mineral precipitation and the sigmoidal shape of rate–?G{sub r} relationship can overestimate the extent of feldspar dissolution during CO{sub 2} storage. Finally, the literature on feldspar dissolution in CO{sub 2}-charged systems has been reviewed. The data available are insufficient and new experiments are urgently needed to establish a database on feldspar dissolution mechanism, rates and rate laws, as well as secondary mineral information at CO{sub 2} storage conditions.

Lu, Peng; Fu, Qi; Seyfried, William E. Jr.; Hedges, Sheila W. [U.S. DOE; Soong, Yee [U.S. DOE; Jones, Kyle; Zhua, Chen

2013-01-01

33

A granulometry and secondary mineral fingerprint of chemical weathering in periglacial landscapes and its application to blockfield origins  

NASA Astrophysics Data System (ADS)

A review of published literature was undertaken to determine if there was a fingerprint of chemical weathering in regoliths subjected to periglacial conditions during their formation. If present, this fingerprint would be applied to the question of when blockfields in periglacial landscapes were initiated. These blocky diamicts are usually considered to represent remnants of regoliths that were chemically weathered under a warm, Neogene climate and therefore indicate surfaces that have undergone only a few metres to a few 10s of metres of erosion during the Quaternary. Based on a comparison of clay and silt abundances and secondary mineral assemblages from blockfields, other regoliths in periglacial settings, and regoliths from non-periglacial settings, a fingerprint of chemical weathering in periglacial landscapes was identified. A mobile regolith origin under, at least seasonal, periglacial conditions is indicated where clay(%) ? 0.5*silt(%) + 8 across a sample batch. This contrasts with a mobile regolith origin under non-periglacial conditions, which is indicated where clay(%) ? 0.5*silt(%) - 6 across a sample batch with clay(%) ? 0.5*silt(%) + 8 in at least one sample. A range of secondary minerals, which frequently includes interstratified minerals and indicates high local variability in leaching conditions, is also commonly present in regoliths exposed to periglacial conditions during their formation. Clay/silt ratios display a threshold response to temperature, related to the freezing point of water, but there is little response to precipitation or regolith residence time. Lithology controls clay and silt abundances, which increase from felsic, through intermediate, to mafic compositions, but does not control clay/silt ratios. Use of a sedigraph or Coulter Counter to determine regolith granulometry systematically indicates lower clay abundances and intra-site variability than use of a pipette or hydrometer. In contrast to clay/silt ratios, secondary mineral assemblages vary according to regolith residence time, temperature, and/or precipitation. A microsystems model is invoked as a conceptual framework in which to interpret the concurrent formation of the observed secondary mineral ranges. According to the fingerprint of chemical weathering in periglacial landscapes, there is generally no evidence of blockfield origins under warm Neogene climates. Nearly all blockfields appear to be a product of Quaternary physical and chemical weathering. A more dominant role for periglacial processes in further bevelling elevated, low relief, non-glacial surface remnants in otherwise glacially eroded landscapes is therefore indicated.

Goodfellow, Bradley W.

2012-12-01

34

Secondary minerals of weathered orpiment-realgar-bearing tailings in Shimen carbonate-type realgar mine, Changde, Central China  

NASA Astrophysics Data System (ADS)

The formation and dissolution of arsenic minerals commonly controls the mobility of As in sulfide mines. Here, we present the results of research based on X-ray powder diffraction (XRD), Raman microprobe spectrum, scanning electron microscope (SEM), and transmission electron microscope (TEM) analyses, Scanning transmission X-ray microscope (STXM) and X-ray absorption fine structure (XAFS) analyses to further understand the weathering of orpiment- and realgar-bearing tailings from the Shimen realgar deposit, the largest realgar deposit in Asia. These analyses indicate that four different types of As-bearing secondary minerals are present in the tailings, including arsenic oxides, arsenates, As-gypsum, and As-Fe minerals, and that arsenic in the tailings is present in +3 and +5 valence states. The precipitation of arsenates is attributed to the interaction between As-enriched run-off waters and carbonate minerals. The Ca-arsenates in the tailings are dominantly weilite and pharmacolite, both of which have Ca/As atomic ratios of 1. In addition, SO4 2-/HAsO4 2- substitution in gypsum is another important mechanism of arsenic precipitation.

Zhu, Xiangyu; Wang, Rucheng; Lu, Xiancai; Liu, Huan; Li, Juan; Ouyang, Bingjie; Lu, Jianjun

2014-08-01

35

Secondary minerals of weathered orpiment-realgar-bearing tailings in Shimen carbonate-type realgar mine, Changde, Central China  

NASA Astrophysics Data System (ADS)

The formation and dissolution of arsenic minerals commonly controls the mobility of As in sulfide mines. Here, we present the results of research based on X-ray powder diffraction (XRD), Raman microprobe spectrum, scanning electron microscope (SEM), and transmission electron microscope (TEM) analyses, Scanning transmission X-ray microscope (STXM) and X-ray absorption fine structure (XAFS) analyses to further understand the weathering of orpiment- and realgar-bearing tailings from the Shimen realgar deposit, the largest realgar deposit in Asia. These analyses indicate that four different types of As-bearing secondary minerals are present in the tailings, including arsenic oxides, arsenates, As-gypsum, and As-Fe minerals, and that arsenic in the tailings is present in +3 and +5 valence states. The precipitation of arsenates is attributed to the interaction between As-enriched run-off waters and carbonate minerals. The Ca-arsenates in the tailings are dominantly weilite and pharmacolite, both of which have Ca/As atomic ratios of 1. In addition, SO4 2-/HAsO4 2- substitution in gypsum is another important mechanism of arsenic precipitation.

Zhu, Xiangyu; Wang, Rucheng; Lu, Xiancai; Liu, Huan; Li, Juan; Ouyang, Bingjie; Lu, Jianjun

2015-02-01

36

UK Oil and Gas Collaborative Doctoral Training Centre (2015 start) Project Title: Authigenic mineral corrosion and the origins of secondary porosity in lacustrine  

E-print Network

mineral corrosion and the origins of secondary porosity in lacustrine carbonate reservoirs generated significant carbonate-hosted porosity (Wright & Barnett, 2014). What processes could have corroded. This project will therefore test hypotheses for the origin of secondary carbonate-hosted porosity in lacustrine

Henderson, Gideon

37

Radionuclide Incorporation in Secondary Crystalline Minerals Resulting from Chemical Weathering of Selected Waste Glasses: Progress Report: Task kd.5b  

SciTech Connect

Experiments were conducted by Pacific Northwest National Laboratory to evaluate potential incorporation of radionuclides in secondary mineral phases that form from weathering vitrified nuclear waste glasses. These experiments were conducted as part of the Immobilized Low-Activity Waste-Performance Assessment (ILAW-PA) to generate data on radionuclide mobilization and transport in a near-field environment of disposed vitrified wastes. The results of these experiments demonstrated that radionuclide sequestration can be significantly enhanced by promoting the formation of cage structured minerals such as sodalite from weathering glasses. These results have important implications regarding radionuclide sequestration/mobilization aspects that are not currently accounted for in the ILAW PA. Additional studies are required to confirm the results and to develop an improved understanding of the mechanisms of sequestration of radionuclides into the secondary and tertiary weathering products of the ILAW glass to help refine how contaminants are released from the near-field disposal region out into the accessible environment. Of particular interest is to determine whether the contaminants remain sequestered in the glass weathering products for hundreds to thousands of years. If the sequestration can be shown to continue for long periods, another immobilization process can be added to the PA analysis and predicted risks should be lower than past predictions.

Mattigod, Shas V.; Serne, R. Jeffrey; Legore, Virginia L.; Parker, Kent E.; Orr, Robert D.; McCready, David E.; Young, James S.

2003-09-29

38

Secondary alteration of the impactite and mineralization in the basal Tertiary sequence, Yaxcopoil-1, Chicxulub impact crater, Mexico  

NASA Astrophysics Data System (ADS)

The 65 Ma Chicxulub impact crater formed in the shallow coastal marine shelf of the Yucatán Platform in Mexico. Impacts into water-rich environments provide heat and geological structures that generate and focus sub-seafloor convective hydrothermal systems. Core from the Yaxcopoil-1 (Yax-1) hole, drilled by the Chicxulub Scientific Drilling Project (CSDP), allowed testing for the presence of an impact-induced hydrothermal system by: a) characterizing the secondary alteration of the 100 m-thick impactite sequence; and b) testing for a chemical input into the lower Tertiary sediments that would reflect aquagene hydrothermal plume deposition. Interaction of the Yax-1 impactites with seawater is evident through redeposition of the suevites (unit 1), secondary alteration mineral assemblages, and the subaqueous depositional environment for the lower Tertiary carbonates immediately overlying the impactites. The least-altered silicate melt composition intersected in Yax-1 is that of a calc-alkaline basaltic andesite with 53.4-56 wt% SiO2 (volatile-free). The primary mineralogy consists of fine microlites of diopside, plagioclase (mainly Ab 47), ternary feldspar (Ab 37 to 77), and trace apatite, titanite, and zircon. The overprinting alteration mineral assemblage is characterized by Mg-saponite, Kmontmorillonite, celadonite, K-feldspar, albite, Fe-oxides, and late Ca and Mg carbonates. Mg and K metasomatism resulted from seawater interaction with the suevitic rocks producing smectite-Kfeldspar assemblages in the absence of any mixed layer clay minerals, illite, or chlorite. Rare pyrite, sphalerite, galena, and chalcopyrite occur near the base of the impactites. These secondary alteration minerals formed by low temperature (0-150 °C) oxidation and fixation of alkalis due to the interaction of glass-rich suevite with down-welling seawater in the outer annular trough intersected at Yax-1. The alteration represents a cold, Mg-K-rich seawater recharge zone, possibly recharging higher temperature hydrothermal activity proposed in the central impact basin. Hydrothermal metal input into the Tertiary ocean is shown by elevated Ni, Ag, Au, Bi, and Te concentrations in marcasite and Cd and Ga in sphalerite in the basal 25 m of the Tertiary carbonates in Yax-1. The lower Tertiary trace element signature reflects hydrothermal metal remobilization from a mafic source rock and is indicative of hydrothermal venting of evolved seawater into the Tertiary ocean from an impact generated hydrothermal convective system.

Ames, Doreen E.; Kjarsgaard, Ingrid M.; Pope, Kevin O.; Dressler, Burkhard; Pilkington, Mark

2004-07-01

39

Vascular tissue engineering: microtextured scaffold templates to control organization of vascular smooth muscle cells and  

E-print Network

Vascular tissue engineering: microtextured scaffold templates to control organization of vascular 2004 Abstract The in vitro construction of tissue-engineered small diameter (; Vascular tissue engineering; Fibronectin 1. Introduction The development of tissue-engineered vascular

40

Applying Micro-Texture to Cast Iron Surfaces to Reduce the Friction Coefficient Under Lubricated Conditions  

Microsoft Academic Search

The tribological properties of cast iron have been investigated to determine the effects of micro-texturing the surfaces.\\u000a The micro-textured surfaces were prepared by shot blasting or milling using a shaper. The surfaces with groove patterns and\\u000a mesh patterns had higher friction coefficients than the flat surfaces. The surfaces with dimpled patterns had lower friction\\u000a coefficients than the flat surfaces. The

Miki Nakano; Atsuko Korenaga; Atsushi Korenaga; Koji Miyake; Takashi Murakami; Yasuhisa Ando; Hatsuhiko Usami; Shinya Sasaki

2007-01-01

41

Secondary mineral growth in fractures in the Miravalles geothermal system, Costa Rica  

SciTech Connect

A mineralogical, fluid-chemical, and theoretical study of hydrothermal alteration in veins from drillcore from the Miravalles geothermal field, Costa Rica has revealed a complex history of mineral-fluid reaction which may be used to characterize changes in temperature and fluid composition with time. Mineralogical and mineral-chemical data are consistent with hydrothermal alteration in the temperature range 200{sup 0}-270{sup 0}C, with deeper portions of the system having undergone temperatures in excess of 300{sup 0}C. Thermodynamic calculations suggest that the observed alteration assemblage is not equilibrium with current well fluids, unless estimates of reservoir pH are incorrect. Fe-Al zoning of prehnite and epidote in veins is consistent with rapid, isothermal fluctuations in fluid composition at current reservoir temperatures, and may be due to changes in volatile content of the fluid due to tectonic activity.

Rochelle, C.A. (Leeds Univ. (UK). Dept. of Earth Sciences); Milodowski, A.E.; Savage, D. (British Geological Survey, Keyworth (UK). Fluid Processes Research Group); Corella, M. (Instituto Costarricense de Electricidad, San Jose (Costa Rica))

1989-01-01

42

The Effects of Secondary Mineral Precipitates on 90Sr Mobility at the Hanford Site, USA  

SciTech Connect

The effects of secondary precipitates on 90Sr transport at the Hanford Site were investigated using quartz column experiments with simulated caustic tank waste leachates (STWL). Significantly enhanced retardation of Sr transport was observed in the column contacted with STWL due to Sr sorption and co-precipitation with neo-formed nitratecancrinite. However, the column results also suggest that neo-formed secondary precipitates could behave like native mobile colloids that can enhance Sr transport. Initially immobilized Sr within secondary precipitates could remobilize given a change in the porewater background conditions. The mobility of the neo-formed Sr-bearing precipitates increased with increased solution flow rate. In the field, porewater contents and flow rates can be changed by snowmelt (or storm water) events or artificial infiltration. The increased porewater flow rate caused by these events could affect the mobility of 90Sr-containing secondary precipitates, which can be a potential source for facilitated Sr transport in Hanford Site subsurface environments.

Um, Wooyong; Wang, Guohui; Serne, R. Jeffrey

2013-06-03

43

Characterization of Secondary Mineral Grain Coatings and their Role as Diffusion-controlled Sinks and Sources for Metal Contaminants  

NASA Astrophysics Data System (ADS)

Many important geochemical reactions occur at the mineral-water interface, including sorption and desorption reactions of contaminants. Fundamental knowledge of the kinetics of these processes is based primarily on experimental observations of reactions at faces of single crystals or macroscopic data from pure mineral powder suspensions. Sorption reactions at crystal faces are generally very fast, on the order of microseconds or less, with reaction times often limited only by film diffusion at the mineral-water interface. In well-stirred suspensions of aquifer sediments, however, sorptive equilibrium can take many hours or days to achieve steady-state concentrations. We have examined the potential reasons for sorption rate limitation using uranium(VI) sorption by sediments from a sandy aquifer in Savannah River, South Carolina (USA). U(VI) sorption by sand-sized grains from the aquifer is dominated by reaction with secondary mineral coatings on quartz and feldspar grains. The coatings studied were on the order of 15 microns in thickness (i.e., from quartz grain to aqueous solution) and composed primarily of clay minerals and hematite of varying particle size. Microfocused-XRF imaging of elemental concentrations (e.g., U, Fe) of polished cross-sections of the grain/coating contact showed strong spatial correlations of U and Fe within the coatings, regardless of the length of reaction time (30 minutes to 4 weeks). The spatial resolution of the ?-XRF technique is of the order of 2 microns in horizontal directions, but the uncertainty of the observed spatial gradients is high due to grain curvature away from the polished surface and fluorescence contributed from the entire 30 micron thickness of a typical grain/epoxy thin section. TEM characterization of focused-ion-beam (FIB), vertically-extracted samples of the grain-coating contact shows that complex pore networks exist within the coatings of variable dimensions and unknown connectivity. Using scanning TEM (STEM) tomography, it can be seen that there are large numbers of pore throat sizes less than 10 nm within the coatings. We hypothesize that diffusion through these pores, which likely have electrically charged surfaces, controls the observed macroscopic rates of U(VI) sorption in batch experiments with sand grains. Evidence to support this hypothesis was observed by studying U and Fe fluorescence spatial variation within FIB samples (1 micron thick) at 200 nm spatial resolution. With this greater spatial resolution, it is possible to see U concentration variations within the coatings that are dependent on the time of sorption reaction, and illustrates how the coating environment constitutes a diffusion constraint to achieve adsorptive equilibrium between an aqueous phase and the mineral surfaces. Including this diffusion constraint within conceptual models for reactive contaminant transport may be significant at the field scale, because secondary mineral coatings are potentially both sinks and sources of contaminants depending on the history of a contaminated site. This is important in resolving long-term transport predictions at DOE sites, such as Hanford and Savannah River, where equilibrium versus kinetic reactive transport models are being evaluated.

Davis, J. A.; Guo, H.; Lai, B.; Kemner, K. M.; Ercius, P.; Fox, P. M.; Singer, D. M.; Minor, A.; Waychunas, G.

2012-12-01

44

Exchangeable and secondary mineral reactive pools of aluminium in coastal lowland acid sulfate soils.  

PubMed

The use of coastal floodplain sulfidic sediments for agricultural activities has resulted in the environmental degradation of many areas worldwide. The generation of acidity and transport of aluminium (Al) and other metals to adjacent aquatic systems are the main causes of adverse effects. Here, a five-step sequential extraction procedure (SEP) was applied to 30 coastal lowland acid sulfate soils (CLASS) from north-eastern New South Wales, Australia. This enabled quantification of the proportion of aluminium present in 'water-soluble', 'exchangeable', 'organically-complexed', 'reducible iron(III) (oxyhydr)oxide/hydroxysulfate-incorporated' and 'amorphous Al mineral' fractions. The first three extractions represented an average of 5% of 'aqua regia' extractable Al and their cumulative concentrations were extremely high, reaching up to 4000 mg·kg(-1). Comparison of Al concentrations in the final two extractions indicated that 'amorphous Al minerals' are quantitatively a much more important sink for the removal of aqueous Al derived from the acidic weathering of these soils than reducible Fe(III) minerals. Correlations were observed between soil pH, dissolved and total organic carbon (DOC and TOC) and Al concentrations in organic carbon-rich CLASS soil horizons. These results suggest that complexation of Al by dissolved organic matter significantly increases soluble Al concentrations at pH values >5.0. As such, present land management practices would benefit with redefinition of an 'optimal' soil from pH ?5.5 to ~4.8 for the preservation of aquatic environments adjacent to organic-rich CLASS where Al is the sole or principle inorganic contaminant of concern. Furthermore, it was observed that currently-accepted standard procedures (i.e. 1 M KCl extraction) to measure exchangeable Al concentrations in these types of soils severely underestimate exchangeable Al and a more accurate representation may be obtained through the use of 0.2 M CuCl2. PMID:24727041

Yvanes-Giuliani, Yliane A M; Waite, T David; Collins, Richard N

2014-07-01

45

Al(Fe,Ti,Si)-mobility and secondary mineralization implications: A case study of the karst unconformity diasporite-type bauxite horizons in Milas (Mu?la), Turkey  

NASA Astrophysics Data System (ADS)

The Paleogene aged metabauxite deposit in the Upper Cretaceous-Early Paleogene aged marble sequence within the southwestern Menderes Massif in the ?lbir Mountains of the Milas (Mu?la) region of SW Turkey comprises many initially karst unconformity-type bauxite horizons with unusual Al-mobility. Thus, it displays singular geochemical and mineralogical implications. The settling down of these horizons was syngenetic with limestone sedimentation, as evidenced by their lithologic associations. In the region, they are mainly found as karst unconformity diasporite-type upper bauxite horizons due to lower-graded burial metamorphism in the Küçükçaml?k and Büyükçaml?k hills, and also found as emery type lower bauxite horizons due to higher-graded burial metamorphism in the Menevi? and Kure streams. The main focus of this study was the upper bauxite horizons because they contain significant secondary Al- and Fe(Ti)-rich mineralization in the structurally-controlled open spaces (fracture zones) crosscutting the brittle bauxite horizons. This secondary mineralization is unique worldwide because the fracture zones contain coarse crystals of secondary minerals, such as gem-quality diaspore, muscovite, specular hematite, ilmenite, goethite, and chloritoid. These secondary metamorphic minerals were formed by high-temperature hydrothermal activity involving metamorphic remobilized reactions of extraction, mobilization, migration and re-crystallization, from the primary metamorphic mineral constituents in the metabauxite ore bodies. Thus, within the well known Mediterranean Bauxite Belt (MBB) in southern Europe trending from Portugal through Turkey, the metabauxite deposit in the ?lbir Mountains is noteworthy for the coexistence of two serial phases of metamorphic mineralization which occurred when the metabauxite deposit was modified by late-stage Alpine tectono-metamorphism in the Menderes Massif. This study is mainly focused on the original primary metamorphic submicroscopic mineralization, including polycrystalline (overlapped) occurrences, and uses the comparative matching technique on X-ray diffraction patterns to confirm that the main constituents of the karst unconformity-type diasporic metabauxite (diasporite) ore were the main source for secondary metamorphic mineralization in the fracture zones. It was found that the submicroscopic mineral constituents in the original primary diasporite ore are diaspore, gibbsite, corundum, specular hematite, ilmenite, donbassite and chloritoid as major constituents, with goethite, ferroalluaudite and Fe-Mg-rich muscovite as minor constituents. It was concluded that the composition of the primary fine-grained mineralization in the unaltered (original) bauxite ore was adequate to serve as a source for the much coarser later mineralization in the fracture zones.

Hatipo?lu, Murat

2011-05-01

46

Radioelements and their occurrence with secondary minerals in heated and unheated tuff at the Nevada Test Site  

SciTech Connect

Samples of devitrified welded tuff near and away from the site of a heater test in Rainier Mesa were examined with regard to whole-rock radioelement abundances, microscopic distribution of U, and oxygen isotope ratios. Wholerock U averages between 4 and 5 ppM, and U is concentrated at higher levels secondary opaque minerals as well as in accessory grains. U in primary and secondary sites is most commonly associated with Mn phases, which average {approximately}30 ppM U in more uraniferous occurrences. This average is consistent and apparently unaffected by proximity to the heater. The Mn phases differ compositionally from Mn minerals in other NTS tuffs, usually containing abundant Fe, Ti, and sometimes Ce, and are often poorly crystalline. Oxygen isotope ratios show some depletion in {delta}{sup 18}O in tuff samples very close to the heater; this depletion is consistent with isotopic exchange between the tuff and interstitial water, but it may also reflect original heterogeneity in isotopic ratios of the tuff unrelated to the heater test. Seismic properties of several tuff samples were measured. Significant differences correlating with distance from the heater occur in P- and S-wave amplitudes; these may be due to loss of bound water. Seismic velocities are nearly constant and indicate a lack of significant microcracking. The absence of clearer signs of heater-induced U mobilization or isotopic variations may be due to the short duration of the heater test, and to insufficient definition of pre-heater-test heterogeneities in the tuff.

Flexser, S.; Wollenberg, H.A.

1992-06-01

47

Fractionation of Stable Si Isotopes During in-situ Dissolution of Feldspars and Formation of Secondary Clay Minerals  

NASA Astrophysics Data System (ADS)

It has been proposed that weathering of igneous silicate minerals may fractionate Si isotopes (Douthitt 1982, de la Rocha et al. 2000). This is supported by the observation that clays yield ?30Si compositions between +0.5‰ and -2.5‰ compared to the igneous range for ?30Si between +0.1‰ and -1‰ respectively (Douthitt 1982). The difference may relate to a discrimination against heavier Si isotopes during clay mineral formation. However, no study has yet shown a direct Si isotope fractionation between coexisting primary igneous and secondary clay mineral phases. We have measured the stable Si isotope fractionation during in-situ feldspar dissolution and formation of secondary clay minerals in the Navajo Sandstone, Black Mesa, Arizona. The Jurassic Navajo Sandstone is composed of about 94% quartz and 2-4% K-feldspar. The K-feldspar grains are covered with kaolinite, and both quartz and feldspars are covered with a mantle of smectite coating. Petrographic studies demonstrate that the clay minerals formed in situ as alteration products of feldspar, and the smectite is of a low-temperature variety (Zhu, 2005). Therefore, the Si isotope fractionation at low temperature (15-35°C) can be evaluated - something that is difficult to replicate in the laboratory. For the Si isotope analyses we used 20-30 mg of 5 separated clay samples, and 0.36 mg of hand picked feldspars. The silicates were fused with an alkaline flux and dissolved in a weak HCl acid. The dissolved Si was then separated by ion-exchange chromatography. The relative Si isotope compositions were measured using a high-resolution MC-ICP-MS (The Nu1700 at ETH Zurich) and are reported in ? notation relative to the international Si standard NBS 28. The bulk rock and separated feldspar fraction have Si isotope compositions are -0.09 ± 0.03‰ and -0.15 ±0.03 ‰ (±2?SEM) ?30Si, respectively. The clay samples have ?30Si values of -0.24 ±0.05‰, -0.16 ±0.03‰, -0.30 ±0.03‰, -0.42 ±0.03‰ and -0.52 ±0.04‰ (±2?SEM). These Si isotope analyses reveal that the majority of the clay separates are isotopically lighter by up to 0.4% compared to precursor feldspars. The results demonstrate for the first time that Si isotopes are indeed fractionated during the breakdown of feldspar minerals and the subsequent formation of isotopically lighter Si in clays. From mass-balance considerations, circulating fluids should have higher ?30Si values, however the analysis of groundwater samples show variations of ?30Si values between +0.43‰ and -1.43‰ representing the most negative dissolved Si isotope composition so far found. As groundwater constitutes 98% of the global fresh water (excluding ice), the global Si biogeochemical cycle must include groundwater as an important component that is often overlooked. References: De La Rocha, Brzezinski, and DeNiro (2000), A first look at the distribution of the stable isotopes of silicon in natural waters, GCA 64, 2467-2477; Douthitt (1982), The geochemistry of the stable isotopes of silicon, GCA 46, 1449 - 1458; Zhu (2005), In situ feldspar dissolution rates in an aquifer, GCA 69, 1435-1453.

Georg, R. B.; Reynolds, B. C.; Halliday, A. N.; Zhu, C.

2005-12-01

48

Syntrophic Effects in a Subsurface Clostridial Consortium on Fe(III)-(Oxyhydr)oxide Reduction and Secondary Mineralization  

SciTech Connect

In this study, we cultivated from subsurface sediments an anaerobic Clostridia 25 consortium that was composed of a fermentative Fe-reducer Clostridium species (designated as 26 strain FGH) and a novel sulfate-reducing bacterium belonging to the Clostridia family 27 Vellionellaceae (designated as strain RU4). In pure culture, Clostridium sp. strain FGH mediated 28 the reductive dissolution/transformation of iron oxides during growth on peptone. When 29 Clostridium sp. FGH was grown with strain RU4 on peptone, the rates of iron oxide reduction 30 were significantly higher. Iron reduction by the consortium was mediated by multiple 31 mechanisms, including biotic reduction by Clostridium sp. FGH and biotic/abiotic reactions 32 involving biogenic sulfide by strain RU4. The Clostridium sp. FGH produced hydrogen during 33 fermentation, and the presence of hydrogen inhibited growth and iron reduction activity. The 34 sulfate-reducing partner strain RU4 was stimulated by the presence of H2 gas and generated 35 reactive sulfide which promoted the chemical reduction of the iron oxides. Characterization of 36 Fe(II) mineral products showed the formation of magnetite during ferrihydrite reduction, and 37 the precipitation of iron sulfides during goethite and hematite reduction. The results suggest an 38 important pathway for iron reduction and secondary mineralization by fermentative sulfate-39 reducing microbial consortia is through syntrophy-driven biotic/abiotic reactions with biogenic 40 sulfide.

Shah, Madhavi; Lin, Chu-Ching; Kukkadapu, Ravi K.; Engelhard, Mark H.; Zhao, Xiuhong; Wang, Yangping; Barkay, Tamar; Yee, Nathan

2013-12-02

49

Effect of mineral dust on secondary organic aerosol yield and aerosol size in ?-pinene/NOx photo-oxidation  

NASA Astrophysics Data System (ADS)

Although it is a significant contributor to atmospheric particles, the role of mineral dust in secondary organic aerosol (SOA) formation has not been fully recognized. In this study, alumina was chosen as the surrogate to investigate the effect of mineral dust on ?-pinene/NOx photo-oxidation in a 2 m3 smog chamber at 30 °C and 50% relative humidity (RH). Results showed that alumina seeds could influence both the SOA yield and the aerosol size in the photo-oxidation process. Compared to the seed-free system, the presence of alumina seeds resulted in a slight reduction of SOA yield, and also influenced the final concentration of O3 in the chamber. As an important oxidant of ?-pinene, the decrease in O3 concentration could reduce the formation of semi-volatile compounds (SVOCs) and consequently inhibited SOA formation. In addition, the size of aerosol was closely related with the mass loading of alumina seeds. At low alumina concentration, SVOCs condensed onto the pre-existing seed surface and led to aerosol size growth. When alumina concentration exceeded about 5 ?g m-3, SVOC species that condensed to each seed particle were dispersed by alumina seeds, resulting in the decrease in aerosol size.

Liu, Chang; Chu, Biwu; Liu, Yongchun; Ma, Qingxin; Ma, Jinzhu; He, Hong; Li, Junhua; Hao, Jiming

2013-10-01

50

Evidence for biological activity in mineralization of secondary sulphate deposits in a basaltic environment: implications for the search for life in the Martian subsurface  

SciTech Connect

Evidence of microbial activity associated with mineralization of secondary Na-sulphate minerals (thenardite, mirabilite) in the basaltic subsurface of Craters of the Moon National Monument (COM), Idaho were examined by scanning electron microscopy, X-ray diffraction, laser desorption Fourier transform ion cyclotron resonance mass spectrometry (LD-FTICR-MS), Fourier transform infrared spectroscopy (FTIR) and isotope ratio mass spectrometry. Peaks suggestive of bio/organic compounds were observed in the secondary Na-sulphate deposits by LD-FTICR-MS. FTIR provided additional evidence for the presence of bio/organic compounds. Sulphur fractionation was explored to assist in determining if microbes may play a role in oxidizing sulphur. The presence of bio/organic compounds associated with Na-sulphate deposits, along with the necessity of oxidizing reduced sulphur to sulphate, suggests that biological activity may be involved in the formation of these secondary minerals. The secondary Na-sulphate minerals probably form from the overlying basalt through leached sodium ions and sulphate ions produced by bio-oxidation of Fe-sulphide minerals. Since the COM basalts are one of the most comparable terrestrial analogues for their Martian counterparts, the occurrence of biological activity in the formation of sulphate minerals at COM has direct implications for the search for life on Mars. In addition, the presence of caves on Mars suggests the importance of these environments as possible locations for growth and preservation of microbial activity. Therefore, understanding the physiochemical pathways of abiotic and biotic mineralization in the COM subsurface and similar basaltic settings has direct implications for the search for extinct or extant life on Mars.

C. Doc Richardson; Nancy W. Hinman; Jill R. Scott

2013-10-01

51

Water chemistry impacts on arsenic mobilization from arsenopyrite dissolution and secondary mineral precipitation: implications for managed aquifer recharge.  

PubMed

Managed aquifer recharge (MAR) is a water reuse technique with the potential to meet growing water demands. However, MAR sites have encountered arsenic mobilization resulting from recharge operations. To combat this challenge, it is imperative to identify the mechanisms of arsenic mobilization during MAR. In this bench-scale study, arsenic mobilization from arsenopyrite (FeAsS) was characterized for conditions relevant to MAR operations. Experimentally determined activation energies for arsenic mobilization from FeAsS under aerobic conditions were 36.9 ± 2.3 kJ/mol for 10 mM sodium chloride, 40.8 ± 3.5 kJ/mol for 10 mM sodium nitrate, and 43.6 ± 5.0 kJ/mol for secondary effluent from a wastewater treatment plant. Interestingly, the sodium chloride system showed higher arsenic mobilization under aerobic conditions. In addition, secondary mineral precipitation varied among systems and further affected arsenic mobilization. For example, the wastewater system inhibited precipitation, while in the sodium chloride system, faster phase transformation of iron(III) (hydr)oxide precipitates was observed, resulting in hematite formation after 7 days. The phase transformation to hematite will result in less available surface area for arsenic attenuation. These new observations and activation energies can be useful to develop improved reactive transport models for the fate of arsenic during MAR, and develop strategies to minimize arsenic release. PMID:24621369

Neil, Chelsea W; Yang, Y Jeffrey; Schupp, Don; Jun, Young-Shin

2014-04-15

52

Secondary hyperparathyroidism but stable bone-mineral density in patients with chronic myeloid leukemia treated with imatinib.  

PubMed

Imatinib is currently the standard treatment for chronic myeloid leukemia(CML). Previous studies have shown that imatinib affects bone metabolism in CML patients. However, these effects are not well-studied prospectively. The authors studied bone-mineral density (BMD) and bone metabolism in 17 CML patients and matched controls in 2007 and now repeated the analyses prospectively in 2011. All CML patients were in complete cytogenetic remission during this 4-year period and treated with 400 mg imatinib q.d. (n 5 15) or 600 mg imatinib q.d. (n 5 2). Mean treatment duration was 102 months (range 69–129) in 2011. The authors found that serum levels of parathyroid hormone increased significantly in the patients between 2007 and 2011, and seven out of 17 patients had secondary hyperparathyroidism in 2011. However, the mean areal and volumetric BMDs were stable in the CML patients over the 4-year-observation period. Moreover, the CML patients had significantly higher volumetric BMD in the cortical compartment when compared with controls in 2011 and 2007. Thus, despite a high incidence of secondary hyperparathyroidism,there were no signs of osteoporosis or osteomalacia in imatinib-treated CML patients as suggested earlier. PMID:22407760

Jönsson, Sofia; Standal, Therese; Olsson, Bob; Mellström, Dan; Wadenvik, Hans

2012-05-01

53

Secondary arsenic minerals and arsenic mobility in a historical waste rock pile at Ka?k near Kutná Hora, Czech Republic  

NASA Astrophysics Data System (ADS)

The arsenic mineralization in historical waste rock pile at Ka?k site near Kutná Hora developed over a period of about 500 years. The objective of this study was to determine principal secondary arsenic mineral phases and their environmental stability. The only common primary As-bearing mineral - arsenopyrite - occurs in the mineral assemblage of Kutná Hora base-metal deposit together with quartz, pyrite, sphalerite, and pyrrhotite. Most of arsenic is bound in supergene minerals (scorodite, jarosite-beudantite, bukovskýite, pitticite), which are relatively stable under oxidizing conditions prevailing in the pile. The Ka?k site is a type locality for bukovskýite, ka?kite, zýkaite, and parascorodite. In long-term perspective, the most stable minerals from viewpoint of As-binding appear to be scorodite and beudantite. A higher mobility was observed for As incorporated into jarosite and poorly crystalline to amorphous phases (FeIII -oxyhydroxides, pitticite). This study has not confirmed significant mobility of arsenic within the pile and water infiltrating in recharge periods of the year (late winter-early spring) should not mobilize arsenic at a significant rate. However, monitoring of the stability of secondary As-phases and dissolved arsenic in the environment around the pile is required to avoid future migration of arsenic out of the pile.

Kocourková-Víšková, E.; Loun, J.; Sracek, O.; Houzar, S.; Filip, J.

2015-02-01

54

Comment on: “Origin, timing, and temperature of secondary calcite-silica mineral formation at Yucca Mountain, Nevada” by N. S. F. Wilson, J. S. Cline, and Y. V. Amelin  

Microsoft Academic Search

Yucca Mountain in southern Nevada is being evaluated as a potential site for the geological disposal of high-level nuclear waste. A reliable assessment of the future performance of the repository will require detailed paleohydrogeological information. Hydrogenic secondary minerals from the vadose zone of Yucca Mountain are being studied as paleohydrogeological indicators. A phenomenological model envisaging the deposition of secondary minerals

Yuri V. Dublyansky; Sergey Z. Smirnov; Sergey E. Pashenko

2005-01-01

55

Comment on: ``Origin, timing, and temperature of secondary calcite-silica mineral formation at Yucca Mountain, Nevada'' by N. S. F. Wilson, J. S. Cline, and Y. V. Amelin  

Microsoft Academic Search

Yucca Mountain in southern Nevada is being evaluated as a potential site for the geological disposal of high-level nuclear waste. A reliable assessment of the future performance of the repository will require detailed paleohydrogeological information. Hydrogenic secondary minerals from the vadose zone of Yucca Mountain are being studied as paleohydrogeological indicators. A phenomenological model envisaging the deposition of secondary minerals

Yuri V. Dublyansky; Sergey Z. Smirnov; Sergey E. Pashenko

2005-01-01

56

Mechanically robust superamphiphobic aluminum surface with nanopore-embedded microtexture.  

PubMed

A simple fabrication technique was developed for preparing a mechanically robust superamphiphobic surface on an aluminum (Al) plate. Dual geometric architectures with micro- and nanoscale structures were formed on the surface of the Al plate by a combination of simple chemical etching and anodization. This proposed methodology involves (1) fabrication of irregular microscale plateaus on the surface of the Al plate, (2) formation of nanopores, and (3) fluorination. Wettability measurements indicated that the fabricated Al surface became super-repellent toward a broad range of liquids with surface tension in the range 27.5-72 mN/m. By varying the anodization time, we measured and compared the effects of morphological change on the wettability. The adhesion property and mechanical durability of the fabricated superamphiphobic Al surface were evaluated by the Scotch tape and hardness tests, respectively. The results showed that the fabricated Al surface retained mechanical robustness because the down-directed surface made by nanopores on the microtextured surface was durable enough even after high force was applied. Almost no damage of the film was observed, and the surface still exhibited superamphiphobicity after the tests. The fabricated superamphiphobic surface also remained stable after long-term storage. The simple and time-saving fabrication technique can be extended to any large-area three-dimensional surface, making it potentially suitable for large-scale industrial fabrications of mechanically robust superamphiphobic surfaces. PMID:23980795

Barthwal, Sumit; Kim, Young Su; Lim, Si-Hyung

2013-09-24

57

Superhydrophobic surfaces by replication of micro/nano-structures fabricated by ultrafast-laser-microtexturing  

NASA Astrophysics Data System (ADS)

We report a simple and inexpensive method of producing superhydrophobic surfaces by directly replicating micro/nano-structures on to poly(dimethylsiloxane) (PDMS) from a replication master prepared by ultrafast-laser microtexturing process. No additional coatings on PDMS have been required to achieve contact angles greater than 154°. The contact angle can be controlled by changing the height of the microtextures in PDMS. Very low optical reflection properties of micro/nano textured surfaces combined with superhydrophobic characteristics make it an attractive encapsulating material for photovoltaics and other applications. Additionally, this replication method can be applied for large scale production of micro/nano textured superhydrophobic surfaces for commercial applications.

Nayak, Barada K.; Caffrey, Paul O.; Speck, Christian R.; Gupta, Mool C.

2013-02-01

58

Solution Spraying of Poly(methyl methacrylate) Blends to Fabricate Micro-textured, Superoleophobic  

E-print Network

electrostatic field to accelerate a polymer solution jet at room temperatures, again producing very fine spinning" technique to produce fibers with diameters of 1m and smaller from a polymer solution by using simple spraying technique to fabricate various microtextured surfaces from a polymer solution containing

59

A thermoresponsive, microtextured substrate for cell sheet engineering with defined structural organization  

E-print Network

A thermoresponsive, microtextured substrate for cell sheet engineering with defined structural 2008 Elsevier Ltd. All rights reserved. 1. Introduction The structural organization of cells: Thermoresponsive surfaces Surface topography Embossing Cell sheet Tissue engineering Smooth muscle cell a b s t r

60

Assessment of the molecular structure of natrodufrénite - NaFeFe53+()4(·2(HO), a secondary pegmatite phosphate mineral from Minas Gerais, Brazil  

NASA Astrophysics Data System (ADS)

The mineral natrodufrénite a secondary pegmatite phosphate mineral from Minas Gerais, Brazil, has been studied by a combination of scanning electron microscopy and vibrational spectroscopic techniques. Electron probe analysis shows the formula of the studied mineral as (Na0.88Ca0.12)?1.00(Fe0.722+Mn0.11Mg0.08Ca0.04Zr0.01Cu0.01)?0.97(Fe4.893+Al0.02)?4.91(PO4)3.96(OH6.15F0.07)6.22?2.05(H2O). Raman spectroscopy identifies an intense peak at 1003 cm-1 assigned to the PO43- ?1 symmetric stretching mode. Raman bands are observed at 1059 and 1118 cm-1 and are attributed to the PO43- ?3 antisymmetric stretching vibrations. A comparison is made with the spectral data of other hydrate hydroxy phosphate minerals including cyrilovite and wardite. Raman bands at 560, 582, 619 and 668 cm-1 are assigned to the ?4PO43- bending modes and Raman bands at 425, 444, 477 and 507 cm-1 are due to the ?2PO43- bending modes. Raman bands in the 2600-3800 cm-1 spectral range are attributed to water and OH stretching vibrations. Vibrational spectroscopy enables aspects of the molecular structure of natrodufrénite to be assessed.

López, Andrés; Frost, Ray L.; Xi, Yunfei; Scholz, Ricardo; Belotti, Fernanda Maria; Ribeiro, Érika

2013-11-01

61

Assessment of toxic potential of primary and secondary particulates/aerosols from biodiesel vis-à-vis mineral diesel fuelled engine.  

PubMed

Toxicity of engine out emissions from primary and secondary aerosols has been a major cause of concern for human health and environmental impact. This study aims to evaluate comparative toxicity of nanoparticles emitted from a modern common rail direct injection engine (CRDI) fuelled with biodiesel blend (B20) vis-à-vis mineral diesel. The toxicity and potential health hazards of exhaust particles were assessed using various parameters such as nanoparticle size and number distribution, surface area distribution, elemental and organic carbon content and polycyclic aromatic hydrocarbons adsorbed onto the particle surfaces, followed by toxic equivalent factor assessment. It was found that biodiesel particulate toxicity was considerably lower in comparison to mineral diesel. PMID:23631768

Agarwal, Avinash Kumar; Gupta, Tarun; Dixit, Neelabh; Shukla, Pravesh Chandra

2013-05-01

62

Study of microstructure and microtexture of modified 9Cr-1Mo steel subjected to high deformation  

NASA Astrophysics Data System (ADS)

The Nb-V modified 9Cr-1Mo ferritic steel is an extremely important structural material in the power industry. Present work is focused on how the microstructure, microchemistry and microtexture of this steel evolve during high degree of deformation, starting from the normalized and tempered condition. While the microstructure and microchemistry are analyzed using analytical transmission electron microscopy, the microtexture analysis is carried out using the electron back-scatter diffraction (EBSD) technique. High degree of cold rolling leads to the formation of forests of dislocations and cellular structure of ferritic matrix. The carbides were found to retain their morphology and chemistry after 88% cold work. Analysis of misorientation angles was used to derive the grain boundary character of the normalized and tempered steel and the deformed steel. Analysis of fiber texture reveals that deformation in the material does not lead to predominance of any particular fiber which is useful from fabrication point of view.

Parida, Pradyumna Kumar; Dasgupta, Arup; Saibaba, Saroja

2013-01-01

63

Time–temperature evolution of microtextures and contained fluids in a plutonic alkali feldspar during heating  

Microsoft Academic Search

Microtextural changes brought about by heating alkali feldspar crystals from the Shap granite, northern England, at atmospheric\\u000a pressure, have been studied using transmission and scanning electron microscopy. A typical unheated phenocryst from Shap is\\u000a composed of about 70 vol% of tweed orthoclase with strain-controlled coherent or semicoherent micro- and crypto-perthitic\\u000a albite lamellae, with maximum lamellar thicknesses <1 ?m. Semicoherent lamellae are encircled

Ian ParsonsJohn; John D. Fitz Gerald; James K. W. Lee; Tim Ivanic; Ute Golla-Schindler

2010-01-01

64

Microtexture in the friction-stir weld of an aluminum alloy  

Microsoft Academic Search

In order to characterize plastic flow during friction-stir welding, the microtextures in a friction-stir weld of the precipitation-hardened\\u000a aluminum alloy 6063 have been analyzed by orientation imaging microscopy (OIM). The base-material plate has a Goss orientation.\\u000a The weld center region, except for the upper surface, takes a typical shear texture component with two types of orientations.\\u000a The orientations have a

Yutaka S. Sato; Hiroyuki Kokawa; Keiske Ikeda; Masatoshi Enomoto; Takenori Hashimoto; Shigetoshi Jogan

2001-01-01

65

Teasing apart the contributions of hard dietary items on 3D dental microtextures in primates.  

PubMed

3D dental microtexture analysis is a powerful tool for reconstructing the diets of extinct primates. This method is based on the comparison of fossils with extant species of known diet. The diets of primates are highly diversified and include fruits, seeds, grass, tree leaves, bark, roots, tubers, and animal resources. Fruits remain the main component in the diets of most primates. We tested whether the proportion of fruit consumed is correlated with dental microtexture. Two methods of microtexture analysis, the scale-sensitive fractal analysis (SSFA) and the Dental Areal Surface Texture Analysis (DASTA; after ISO/FDIS 25178-2), were applied to specimens of eight primate species (Alouatta seniculus, Gorilla gorilla, Lophocebus albigena, Macaca fascicularis, Pan troglodytes, Papio cynocephalus, Pongo abelii, Theropithecus gelada). These species largely differ in the mean annual proportion of fruit (from 0 to 90%) in their diet, as well as in their consumption of other hard items (seeds, bark, and insect cuticles) and of abrasive plants. We find the complexity and heterogeneity of textures (SSFA) to correlate with the proportion of fruits consumed. Textural fill volume (SSFA) indicates the proportion of both fruits and other hard items processed. Furthermore, anisotropy (SSFA) relates to the consumption of abrasive plants like grass and other monocots. ISO parameters valley height, root mean square height, material volume, density of peaks, and closed hill and dale areas (DASTA) describe the functional interaction between food items and enamel facets during mastication. The shallow, plastic deformation of enamel surfaces induced by small hard particles, such as phytoliths or dust, results in flat microtexture relief, whereas the brittle, deep fracture caused by large hard items such as hard seeds creates larger relief. PMID:22705031

Calandra, Ivan; Schulz, Ellen; Pinnow, Mona; Krohn, Susanne; Kaiser, Thomas M

2012-07-01

66

Continuous zircon growth during long-lived granulite facies metamorphism: a microtextural, U-Pb, Lu-Hf and trace element study of Caledonian rocks from the Arctic  

NASA Astrophysics Data System (ADS)

Microtextural, U-Pb, trace element and Lu-Hf analyses of zircons from gneisses dredged from the Chukchi Borderland indicate a long-lived, Cambrian-Ordovician, granulite facies metamorphism. These results reveal a complete prograde, peak and cooling history of zircon growth during anatexis. Early increasing temperatures caused modification and Pb-loss of Precambrian zircons by recrystallization and dissolution/re-precipitation of existing grains. Small variations in initial 176Hf/177Hf results (0.282325-0.282042) and flat HREE patterns of these zircons indicate that they grew by dissolution/re-precipitation in the presence of garnet. Zircons subsequently crystallized from a partial melt during peak to post-peak metamorphism from 530 to 485 Ma. A broad range of initial 176Hf/177Hf ratios (0.282693-0.282050) and mineral inclusions within zircons suggest that this phase of growth incorporated Zr and Hf obtained from the breakdown of Zr-enriched phases. Microtextural evidence along with trace element and isotopic data suggests that final growth of metamorphic rims on zircon occurred during slow cooling and crystallization of residual partial melts during the early Ordovician (485-470 Ma). Younger, late Ordovician-Silurian (420-450 Ma) euhedral, oscillatory-zoned, trace element-enriched zircons crystallized within leucocratic veins that intrude the gneisses. Their age corresponds to granitoids dated from this same dredge. The intrusives and veins provide evidence that the Chukchi Borderland rifted from a position near Pearya and northwest Svalbard, which represent the northern continuation of the Caledonian orogen. Evidence for earlier Cambrian metamorphism has not been reported from this region. The age of granulite facies metamorphism reported here represents the earliest phase of deformation in the Arctic Caledonides.

O'Brien, Tim M.; Miller, Elizabeth L.

2014-10-01

67

Fabrication of Highly-Oleophobic and Superhydrophobic Surfaces on Microtextured al Substrates  

NASA Astrophysics Data System (ADS)

Theoretical calculations suggest that creating highly-oleophobic surfaces would require a surface energy lower than that of any known materials. In the present work, we demonstrate microtextured Al substrate surfaces with veins-like micro/nanostructures displaying apparent contact angles (CA) greater than 120°, even with nitromethane (surface tension ?1 = 37 mN/m). The Al substrate was microtextured by a chemical solution mixed by zinc nitrate hexahydrate, hexamethyltetramine and a little of hydrofluoric acid. A fluoroalkylsilane (FAS) agent was used to tune the surface wettability. The Al substrates were microtextured by veins-like micro/nanostructures and generating a solid-liquid-vapor composite interface. Combination with FAS modification, the Al surfaces resulted in an oleophobicity with CA for nitromethane was 126.3° (152.7° for diethylene glycol, ?1 = 45.2 mN/m). In addition, the Al surfaces demonstrated a low rolling-off angle with < 6° even for diethylene glycol. However, nitromethane droplet favored to pin on the sample surface even the sample stage is tilted to 90°. It is noted that this highly-oleophobic behavior is induced mainly by topography, which form a composite surface of air and solid with oil drop sitting partially on air. The results are expected to promote the study on self-cleaning applications, especially in the condition with oil contaminations.

Liu, Changsong; Zhou, Jigen; Zheng, Dongmei; Wan, Yong; Li, Zhiwen

2011-06-01

68

EMSP Project 70070: Reactivity of Primary Soil Minerals and Secondary Precipitates Beneath Leaking Hanford Waste Tanks - Final Report  

SciTech Connect

Since the late 1950s, leaks from 67 single-shell tanks at the Hanford Site have released about 1 million curies to the underlying sediments. The radioactive material was contained in water-based solutions generally characterized as having high pH values (basic solutions), high nitrate and nitrite concentrations, and high aluminum concentrations. The solutions were also hot, in some cases at or near boiling, as well as complex and highly variable in composition reflecting solutions obtained from multiple methods of reprocessing spent nuclear fuel. In order to understand the observed and probable distribution of radionuclides in the ground at Hanford, major reactions that likely occurred between the leaked fluids and the sediment minerals were investigated in laboratory experiments simulating environmental conditions. Reactions involving the dissolution of quartz and biotite and the simultaneous formation of new minerals were quantified at controlled pH values and temperature. Result s show that the dissolution of quartz and formation of new zeolite-like minerals could have altered the flow path of ground water and contaminant plumes and provided an uptake mechanism for positively-charged soluble radionuclides, such as cesium. The dissolution of biotite, a layered-iron-aluminum-silicate mineral, provided iron in a reduced form that could have reacted with negatively-charged soluble chromium, a toxic component of the wastes, to cause its reduction and precipitation as a new reduced-chromium mineral. The quantity of iron released in the experiments is sufficient to explain observations of reductions in dissolved chromium concentration in a plume beneath one Hanford tank. Fundamental data obtained in the project are the rates of the reactions at variable temperatures and pHs. Fundamental data were also obtained on aspects of the surface reactivity of clay or layered-silicate minerals, a small proportion of the total mass of the sediment minerals, but a large proportion of the number of sites where reactions can occur. Results were also finalized on a component of a previous project related to the Hanford waste tanks that had the goal of measuring the incorporation of rhenium, an analogue of radioactive technetium, in iron and aluminum-oxides minerals as they aged in tank sludges at higher temperatures. Small amounts of rhenium were occluded in the iron-rich solids and the amount increased with aging time. Results from the quartz and biotite experiments are in a form that can be used in models of fluid flow in the Hanford subsurface. Results from the rhenium experiments can be used to understand aspects of closing certain of the Hanford tanks.

Kathryn L. Nagy

2004-04-22

69

Enhancing Subsoil Root Activity and Uptake of Mineral N by Gypsum Applications to Secondary Forests Regenerating from Degraded Pastures in Central Amazonia, Brazil  

NASA Astrophysics Data System (ADS)

Conversion of primary tropical forest to pasture radically alters belowground nutrient capture potential. In the absence of deep rooting, these changes can lead to the loss of mobile anions to the subsoil. Abandonment of pastures to invading secondary vegetation may result in the regeneration of some of the original belowground processes and retrieval of previously inaccessible N anions. We hypothesized that gypsum applications increases SF rooting depth and results in a greater portion of total N uptake from subsoil. We applied the following treatments to two replicates of three post-pasture SF age classes: phosphorus (50 kg P/ha as TSP), P + lime (2 t CaCO3/ha), P + lime + gypsum (1 t CaSO4/ha) and an unfertilized control. We sampled soil mineral N concentrations at 10, 150, and 300 cm depth. The youngest SF had less surface mineral N compared to the older forests. Greater surface NO3 and NH4 values in the older SF are reflective of reported increasing total soil N stocks with forest regrowth. Gypsum additions increase subsoil (150 - 180 cm depth) root activity and water uptake. However, our results demonstrated that rather than increasing subsoil N uptake by roots, gypsum applications resulted in 50 % or greater NO3 and NH4 concentrations at 150 cm depth than the other fertilizer treatments. Higher concentrations could be the result of enhanced root production and root turnover, more N mineralization at the topsoil, and/or loss of mobile N anions from surface layers. Secondary forests regrowing from pastures have the potential to increase total soil N rapidly (Feldpausch et al. in review) and prevent mobile N anions from leaching beyond the rooting zone. The more mature SF maintained higher NO3 and NH4 concentrations than the youngest forests, predominately in the first 10 cm. Gypsum can increase subsoil NO3 and NH4 concentrations, which may have important implications to nutrient manage in N-deficient systems.

Feldpausch, T. R.; Fernandes, E. C.; Lehmann, J.

2002-12-01

70

Secondary sulfate minerals associated with acid drainage in the eastern US: Recycling of metals and acidity in surficial environments  

USGS Publications Warehouse

Weathering of metal-sulfide minerals produces suites of variably soluble efflorescent sulfate salts at a number of localities in the eastern United States. The salts, which are present on mine wastes, tailings piles, and outcrops, include minerals that incorporate heavy metals in solid solution, primarily the highly soluble members of the melanterite, rozenite, epsomite, halotrichite, and copiapite groups. The minerals were identified by a combination of powder X-ray diffraction (XRD), scanning electron microscopy (SEM), and electron-microprobe. Base-metal salts are rare at these localities, and Cu, Zn, and Co are commonly sequestered as solid solutions within Fe- and Fe-Al sulfate minerals. Salt dissolution affects the surface-water chemistry at abandoned mines that exploited the massive sulfide deposits in the Vermont copper belt, the Mineral district of central Virginia, the Copper Basin (Ducktown) mining district of Tennessee, and where sulfide-bearing metamorphic rocks undisturbed by mining are exposed in Great Smoky Mountains National Park in North Carolina and Tennessee. Dissolution experiments on composite salt samples from three minesites and two outcrops of metamorphic rock showed that, in all cases, the pH of the leachates rapidly declined from 6.9 to 30 mg L-1), Fe (>47 mg L-1), sulfate (>1000 mg L-1), and base metals (>1000 mg L-1 for minesites, and 2 mg L-1 for other sites). Geochemical modeling of surface waters, mine-waste leachates, and salt leachates using PHREEQC software predicted saturation in the observed ochre minerals, but significant concentration by evaporation would be needed to reach saturation in most of the sulfate salts. Periodic surface-water monitoring at Vermont minesites indicated peak annual metal loads during spring runoff. At the Virginia site, where no winter-long snowpack develops, metal loads were highest during summer months when salts were dissolved periodically by rainstorms following sustained evaporation during dry spells. Despite the relatively humid climate of the eastern United States, where precipitation typically exceeds evaporation, salts form intermittently in open areas, persist in protected areas when temperature and relative humidity are appropriate, and contribute to metal loadings and acidity in surface waters upon dissolution, thereby causing short-term perturbations in water quality.

Hammarstrom, J.M.; Seal, R.R., II; Meier, A.L.; Kornfeld, J.M.

2005-01-01

71

Mineral catalyzed organic synthesis in hydrothermal systems: An experimental study using time-of-flight secondary ion mass spectrometry  

NASA Astrophysics Data System (ADS)

Hydrothermal fluids enriched in hydrocarbons of apparent abiotic origin vent from Fe-Ni sulfide bearing chimney structures on the seafloor at slow spreading mid-ocean ridges. Here we show results from a hydrothermal experiment using carbon isotope labeling techniques and mineral analytical data that indicate that pentlandite ((Fe2Ni7)S8) enhances formation of C2 and C3 alkanes, while also contributing to the formation of other more complex hydrocarbons, such as alcohols and carboxylic acids. ToF-SIMS data reveal the existence of isotopically anomalous carbon on the pentlandite surface, and thus, for the first time, provide unambiguous evidence that mineral catalyzed surface reactions play a role in carbon reduction schemes under hydrothermal conditions. We hypothesize that hydroxymethylene (-CHOH) serves as intermediary facilitating formation of more complex organic compounds. The experimental results provide an explanation for organic synthesis in ultramafic-hosted hydrothermal systems on earth, and on other water-enriched planetary bodies as well.

Fu, Qi; Foustoukos, Dionysios I.; Seyfried, William E.

2008-04-01

72

2D imaging in a 3D world: Observing sub-grain scale variations and secondary mineral precipitates in reacted pore networks  

NASA Astrophysics Data System (ADS)

Advancements in 3D imaging techniques and analysis methods, and easier access to benchtop 3D X-ray microscopes, have led to a proliferation of 3D imaging studies of chemical alterations within porous media. However, 2D imaging methods continue to offer complementary insights into processes controlling sub-grain scale variations in mineralogy and intragranular porosity that are often difficult to observe with 3D methods. For example, 2D imaging studies of mineral precipitation-induced changes in the pore network structure including detailed observations of distributions of secondary mineral precipitates can be coupled with 3D image analysis of a pore network to determine the pore properties required to infer permeability. In this work, the combined advantages of 2D and 3D imaging methods are highlighted through 3D X-ray Computed Microtomography (X-ray CT) and 2D Scanning Electron Microscopy (SEM) imaging of a reacted column experiment in the context of the Hanford, WA site and a sedimentary rock sample from the Alberta basin. Both samples were imaged using 3D X-ray CT imaging at a voxel resolution of 4 ?m and analyzed using 3DMA Rock to determine pore and throat size distributions as well as pore coordination numbers. Polished sections were then created from each sample and imaged using 2D SEM imaging with resolutions of 0.4 ?m for the reacted column and an order of magnitude larger for the sedimentary rock. 2D images were analyzed using an erosion dilation method to determine pore and throat size distributions that were then corrected using sample-specific bias correction factors. The permeability of each sample was predicted from pore network models informed with the 2D or 3D pore and throat size distributions and the coordination numbers determined from the 3D analysis. Differences in 2D and 3D image resolutions resulted in over- or under- estimating small pore throats and led to predicted permeabilities that differed by orders of magnitude. For both samples, higher resolution images resulted in over-estimating small pore throats and under-estimating expected permeability. While higher resolution images are generally favored, they may not improve predictions of permeability as they require additional processing to distinguish small flow-conducting pore throats from surface roughness features. While 3D imaging is required to determine the network coordination, 2D imaging is necessary to understand where secondary minerals precipitate within the pore network and to quantify sub-grain scale variations. These advantages are demonstrated through SEM imaging of polished sections from the reacted column experiment. 2D images revealed that secondary mineral precipitates occurred as a relatively uniform coating on grain surfaces, unrelated to mineralogy, pore size, or other factors. SEM images also revealed new observations of sub-grain scale variations that showed that Hanford sand grains have a high amount of intragranular porosity and mineral precipitates formed in intragranular regions. These observations, which are important to understanding the reactive system, could not have been made if 3D imaging was used exclusively.

Crandell, L. E.; Peters, C. A.; Um, W.; Jones, K. W.; Lindquist, W. B.

2012-12-01

73

Laser surface micro-texturing to enhance the frictional behavior of lubricated steel  

NASA Astrophysics Data System (ADS)

Surface micro-texturing has been widely theoretically and experimentally demonstrated to be beneficial to friction reduction in sliding contacts under lubricated regimes. Several microscopic mechanisms have been assessed to concur to this macroscopic effect. In particular, the micro-textures act as lubricant reservoirs, as well as traps for debris. Furthermore, they may produce a local reduction of the shear stress coupled with a stable hydrodynamic pressure between the lubricated sliding surfaces. All these mechanisms are strongly dependent both on the micro-texturing geometry and on the operating conditions. Among the various micro-machining techniques, laser ablation with ultrashort pulses is an emerging technology to fabricate surface textures, thanks to the intrinsic property of laser light to be tightly focused and the high flexibility and precision achievable. In addition, when using sub-ps pulses, the thermal damage on the workpiece is negligible and the laser surface textures (LST) are not affected by burrs, cracks or resolidified melted droplets, detrimental to the frictional properties. In this work several LST geometries have been fabricated by fs-laser ablation of steel surfaces, varying the diameter, depth and spacing of micro-dimples squared patterns. We compared their frictional performance with a reference nontextured sample, on a range of sliding velocities from the mixed lubrication to the hydrodynamic regime. The measured Stribeck curves data show that the depth and diameter of the microholes have a huge influence in determining the amount of friction reduction at the interface. Different theoretical interpretations to explain the experimental findings are also provided.

Ancona, Antonio; Carbone, Giuseppe; Scaraggi, Michele; Mezzapesa, Francesco P.; Sorgente, Donato; Lugarà, Pietro M.

2014-03-01

74

Spectral reflectance properties (0.4-2.5 um) of secondary Fe-oxide, Fe-hydroxide, and Fe-sulfate-hydrate minerals associated with sulfide-bearing mine waste  

USGS Publications Warehouse

Fifteen Fe-oxide, Fe-hydroxide, and Fe-sulphate-hydrate mineral species commonly associated with sulphide bearing mine wastes were characterized by using X-ray powder diffraction and scanning electron microscope methods. Diffuse reflectance spectra of the samples show diagnostic absorption features related to electronic processes involving ferric and/or ferrous iron, and to vibrational processes involving water and hydroxyl ions. Such spectral features enable field and remote sensing based studies of the mineral distributions. Because secondary minerals are sensitive indicators of pH, Eh, relative humidity, and other environmental conditions, spectral mapping of these minerals promises to have important applications to mine waste remediation studies. This report releases digital (ascii) spectra (spectral_data_files.zip) of the fifteen mineral samples to facilitate usage of the data with spectral libraries and spectral analysis software. The spectral data are provided in a two-column format listing wavelength (in micrometers) and reflectance, respectively.

Crowley, J.K.; Williams, D.E.; Hammarstrom1, J.M.; Piatak, N.; Mars, J.C.; Chou, I-Ming

2006-01-01

75

Spectral reflectance properties (0.4-2.5 ??m) of secondary Fe-oxide, Fe-hydroxide, and Fe-sulphate-hydrate minerals associated with sulphide-bearing mine wastes  

USGS Publications Warehouse

Diffuse reflectance spectra of 15 mineral species commonly associated with sulphide-bearing mine wastes show diagnostic absorption bands related to electronic processes involving ferric and/or ferrous iron, and to vibrational processes involving water and hydroxyl. Many of these absorption bands are relatively broad and overlapping; however, spectral analysis methods, including continuum removal and derivative analysis, permit most of the minerals to be distinguished. Key spectral differences between the minerals are illustrated in a series of plots showing major absorption band centres and other spectral feature positions. Because secondary iron minerals are sensitive indicators of pH, Eh, relative humidity, and other environmental conditions, spectral mapping of mineral distributions promises to have important application to mine waste remediation studies.

Crowley, J.K.; Williams, D.E.; Hammarstrom, J.M.; Piatak, N.; Chou, I.-M.; Mars, J.C.

2003-01-01

76

In Situ Testing of Metal Micro-Textured Thermal Interface Materials in Telecommunications Applications  

NASA Astrophysics Data System (ADS)

A metal micro-textured thermal interface material (MMT-TIM) has been developed to address the shortcomings of conventional TIMs for Remote Radio Heat (RRH) applications. The performance of the MMT-TIM was characterized in-situ by monitoring the temperatures of the dominant heat generating devices in an RRH Power Amplifier for a fixed input power. Measurements show that the use of the MMT-TIM results in significantly lower devices temperatures than achieved with the conventionally used graphite pads with a maximum temperature drop of 14.9 °C observed. The effect of power cycling on the long term performance trends is also examined.

Kempers, R.; Kerslake, S.

2014-07-01

77

Radioactive Bench-scale Steam Reformer Demonstration of a Monolithic Steam Reformed Mineralized Waste Form for Hanford Waste Treatment Plant Secondary Waste - 12306  

SciTech Connect

Hanford currently has 212,000 m{sup 3} (56 million gallons) of highly radioactive mixed waste stored in the Hanford tank farm. This waste will be processed to produce both high-level and low-level activity fractions, both of which are to be vitrified. Supplemental treatment options have been under evaluation for treating portions of the low-activity waste, as well as the liquid secondary waste from the low-activity waste vitrification process. One technology under consideration has been the THOR{sup R} fluidized bed steam reforming process offered by THOR Treatment Technologies, LLC (TTT). As a follow-on effort to TTT's 2008 pilot plant FBSR non-radioactive demonstration for treating low-activity waste and waste treatment plant secondary waste, TTT, in conjunction with Savannah River National Laboratory, has completed a bench scale evaluation of this same technology on a chemically adjusted radioactive surrogate of Hanford's waste treatment plant secondary waste stream. This test generated a granular product that was subsequently formed into monoliths, using a geo-polymer as the binding agent, that were subjected to compressibility testing, the Product Consistency Test and other leachability tests, and chemical composition analyses. This testing has demonstrated that the mineralized waste form, produced by co-processing waste with kaolin clay using the TTT process, is as durable as low-activity waste glass. Testing has shown the resulting monolith waste form is durable, leach resistant, and chemically stable, and has the added benefit of capturing and retaining the majority of Tc-99, I-129, and other target species at high levels. (authors)

Evans, Brent; Olson, Arlin; Mason, J. Bradley; Ryan, Kevin [THOR Treatment Technologies, LLC - 106 Newberry St. SW, Aiken, SC 29801 (United States); Jantzen, Carol; Crawford, Charles [Savannah River Nuclear Solutions (SRNL), LLC, Aiken, SC 29808 (United States)

2012-07-01

78

Acid-etched microtexture for enhancement of bone growth into porous-coated implants.  

PubMed

We designed an in vivo study to determine if the superimposition of a microtexture on the surface of sintered titanium beads affected the extent of bone ingrowth. Cylindrical titanium intramedullary implants were coated with titanium beads to form a porous finish using commercial sintering techniques. A control group of implants was left in the as-sintered condition. The test group was etched in a boiling acidic solution to create an irregular surface over the entire porous coating. Six experimental dogs underwent simultaneous bilateral femoral intramedullary implantation of a control implant and an acid etched implant. At 12 weeks, the implants were harvested in situ and the femora processed for undecalcified, histological examination. Eight transverse serial sections for each implant were analysed by backscattered electron microscopy and the extent of bone ingrowth was quantified by computer-aided image analysis. The extent of bone ingrowth into the control implants was 15.8% while the extent of bone ingrowth into the etched implants was 25.3%, a difference of 60% that was statistically significant. These results are consistent with other research that documents the positive effect of microtextured surfaces on bone formation at an implant surface. The acid etching process developed for this study represents a simple method for enhancing the potential of commonly available porous coatings for biological fixation. PMID:14653605

Hacking, S A; Harvey, E J; Tanzer, M; Krygier, J J; Bobyn, J D

2003-11-01

79

Microtexture tracking of sub-boundary evolution during hot deformation of aluminium  

SciTech Connect

The microstructure and microtexture evolution of the same 3 grains around a triple point has been followed during hot plane strain compression by electron backscattered diffraction (EBSD) up to a strain of 1.2. A large grained model alloy of Al-0.1 wt% Mn was deformed in the form of a split sample in channel die compression at 400 Degree-Sign C by 3 repeated cycles, each involving EBSD grain orientation mapping, hot deformation and quenching. Detailed substructure maps of 3 grains on an inner surface demonstrates that their dislocation substructure develops up to a strain of about 0.5 then stabilises at approximately constant size, disorientation distribution and boundary alignment. The results are consistent with the repolygonisation model of steady state sub-boundary creation and dissolution during hot deformation. - Highlights: Black-Right-Pointing-Pointer Same area around triple point in Al followed by EBSD during hot deformation. Black-Right-Pointing-Pointer Strains from 0 to 1.2 by intervals of about 0.4. Black-Right-Pointing-Pointer Sub-grain microstructure and microtexture stabilise after strains of about 0.5. Black-Right-Pointing-Pointer Results consistent with model of continuous creation and dissolution of sub-grains.

Quey, R.; Driver, J.H., E-mail: driver@emse.fr

2011-12-15

80

Microtexture, asperities, and crack deflection in Al-Li 2090 T8E41  

SciTech Connect

Roughness-induced closure is held to be responsible for very low fatigue crack growth rates observed in certain plate orientations of Al-Li 2090 T8E41, and the geometry of asperities producing this closure correlates with macrotexture. Little work, however, has focused on the role of individual grain orientations (microtexture) or of average orientation within small groups of adjacent grains (mesotexture) on the crack's path through a sample, i.e., on whether the variation in grains' orientations determines where the crack will deflect. This paper reports synchrotron X-ray microbeam diffraction mapping of the three-dimensional microtexture in samples of Al-Li 2090. Groups of adjacent pancake-shaped grains are found to have very similar orientations, producing nearly single-crystal regions approaching thicknesses of 0.3 mm along the sample's S (short-transverse) direction. These near-single-crystal volumes produce large asperities with surfaces having substantial Mode III character, asperities which appear over the range of stress intensity ranges observed (5 to 25 MPa{radical}m). Results of these experiments suggest not only that this type of mesotexture plays an important role in determining fatigue crack path in compact tension samples of Al-Li 2090 but also that specific orientations of the groups of grains lead to large crack deflections.

Haase, J.D.; Guvenilir, A.; Witt, J.R.; Langoey, M.A.; Stock, S.R.

1999-07-01

81

Analysis of behavioural rejection of micro-textured surfaces and implications for recruitment by the barnacle Balanus improvisus  

Microsoft Academic Search

Experiments performed in the field and in the laboratory show that the barnacle, Balanus improvisus, preferentially settles on smooth surfaces. Settlement and recruitment of B. improvisus was evaluated on micro-textured surfaces with scales of surface texture ranging from 1 to 100 ?m in profile heights. Surface texture with profile heights within a topographic range of 30–45 ?m reduced settlement and

Kent M Berntsson; Per R Jonsson; Magnus Lejhall; Paul Gatenholm

2000-01-01

82

Fluid-Dacite Interaction in the PACMANUS Subseafloor Hydrothermal System - Preliminary Results From Secondary Mineral Chemistry and Geochemical Modeling  

NASA Astrophysics Data System (ADS)

During Ocean Drilling Program Leg 193, several holes (as deep as 386 meters below sea floor) intersected variably altered and veined dacites on Pual Ridge in the eastern Manus back-arc basin. The hydothermal alteration is complex and multi-stage, and includes pervasive alteration and alteration halos along anhydrite±pyrite±quartz veins. Our preliminary interpretation is that an early pervasive "chloritic" alteration (chlorite, chlorite/smectite, quartz, +/-albite, +/-magnetite) is overprinted locally by illite-pyrophyllite-anhydrite+/-diaspore alteration followed by silica (quartz and cristobalite) flooding. Two drill holes at Snowcap, a site of diffuse venting, reveal alteration profiles of strongly illite-pyrophyllite-anhydrite altered rocks in the shallow parts grading downwards into rocks that show dominant chloritic alteration. At Roman Ruins, a site of discrete venting, K-feldspar and illite-smectite mixed layer phases are abundant and magnetite is rare. K-feldspar appears to be part of the "chloritic" alteration assemblage. Anhydrite is locally abundant but generally less common than at Snowcap. There is a strong lateral heterogeneity in basement alteration as revealed by the differences between sites in the depths of cristobalite-quartz transition and the zones of prevailing alteration styles. Geochemical modeling suggests that the rocks have been altered at temperatures of about 250 to 300° C under variable fluid-to-rock ratios. While all the mineral assemblages are consistent with quartz/cristobalite saturation of the fluids, the formation of diaspore must be related to episodic interaction of the rocks with fluids highly undersaturated in quartz. The early stage of chloritic alteration represents interaction of the dacites with fluids of a fairly high pH ({>}4). In contrast, the occurrence of pyrophyllite and local diaspore suggests lower pH fluid ({<}3) during later hydrothermal stages. A zone of abundant alunite at 350 m deep in the basement at Snowcap may represent local ingress of very acidic fluids (pH{<}2). Our working hypothesis is that these low-pH fluids indicate significant contributions of a magmatic fluid component that is rich in H2SO4 and HF. Furthermore, the late-stage acidic alteration seems to be more common at Snowcap. Rare-earth element (REE) data from anhydrite veins are consistent with this interpretation. The majority of the anhydrite veins from the Snowcap site display REE patterns that suggest formation of aqueous fluoride and sulfate complexes was important. High F- activities can also be inferred from the presence of minor F-apatite in some anhydrite veins from Snowcap. In contrast, anhydrite from the Roman Ruins site, where evidence for acidic rock alteration style is scarse, shows uniformly light REE enriched patterns.

Yeats, C. J.; Bach, W.; Vanko, D. A.; Roberts, S.; Lackschewitz, K.; Paulick, H.

2001-12-01

83

X-ray microbeam mapping of microtexture related to fatigue crack asperities in Al-Li 2090  

SciTech Connect

In certain orientations, Al-Li 2090 T8E41 cracks more slowly in fatigue than other aluminum alloys due to roughness-induced closure linked to the average texture or macrotexture. For this application, three-dimensional, non-destructive measurement of microtexture and strain evolution within samples was developed using synchrotron polychromatic X-ray microbeam diffraction; its use in mapping the microtexture of fatigue crack asperities in Al-Li 2090 are reported. Groups of adjacent grains with nearly identical orientations were found at numerous locations in the plate centers, and this type of mesotexture appeared closely tied to asperity formation. Changing arrangements of 111 diffraction spots relative to the samples rolling and crack propagation directions are found to correspond to the transitions between a relatively planar section of the crack and an adjacent asperity.

Haase, J.D.; Guvenilir, A.; Witt, J.R.; Stock, S.R. [Georgia Inst. of Tech., Atlanta, GA (United States)] [Georgia Inst. of Tech., Atlanta, GA (United States)

1998-08-10

84

Observation of Micro-scale Surface Morphology with Microtexture Development During Plane Strain Tensile Deformation in AZ31 Magnesium Alloy  

NASA Astrophysics Data System (ADS)

The change of microstructure including microtexture and surface morphology in AZ31 magnesium alloy under plane strain tension was investigated by 3D observation combined confocal microscope and high-resolution electron backscattered diffraction. Micro-scale changes in the surface morphology were observed on the area including tensile twin bands. The mechanism for surface morphology variation was discussed with the nucleation of tensile twinning and the strain partitioning caused by continuing deformation after the nucleation of the twins.

Lee, Keunho; Kim, Kyung Il; Kim, Se-Jong; Suh, Dong-Woo; Oh, Kyu Hwan; Han, Heung Nam

2015-01-01

85

Australian Mineral Foundation.  

ERIC Educational Resources Information Center

Provides details on the philosophy and operation of the Australian Mineral Foundation, established in 1970 to update professionals in the mining and petroleum industries. Services in continuing education courses and to secondary school teachers and students are described. (CS)

Crowe, D. S.

1980-01-01

86

Nanotexturing process on microtextured surfaces of silicon solar cells by SF6/O2 reactive ion etching.  

PubMed

We investigated a nanotexturing process on the microtextured surface of single crystalline silicon solar cell by the reactive ion etching process in SF6/O2 mixed gas ambient. P-type Si wafer samples were prepared using a chemical wet etching process to address saw damage removal and achieve microtexturing. The microtextured wafers were further processed for nanotexturing by exposure to reactive ions within a circular tray of wafer carrier containing many small holes for uniform etching. As the dry etching times were increased to 2, 4 and finally to 8 min, surface structures were observed in a transition from nanoholes to nanorods, and a variation in wafer color from dark blue to black. The surface nanostructures showed a lowered photoreflectance and enhanced quantum efficiency within the visible light region with wavelengths of less than 679 nm. The nanohole structure etched for 2 min showed enhanced conversion efficiency when compared to the bare sample; however, the nanorod structure etched for 8 min exhibited the decreased efficiency with a reduced short circuit current, indicating that the surface nanostructural damage with the enlarged nanoperimetric surface area is sensitive to surface passivation from the surface recombination process. PMID:24266144

Ji, Hyungyong; Choi, Jaeho; Lim, Gyoungho; Parida, Bhaskar; Kim, Keunjoo; Jo, Jung Hee; Kim, Hong Seub

2013-12-01

87

Microtextured metals for stray-light suppression in the Clementine startracker  

NASA Technical Reports Server (NTRS)

Anodized blacks for suppressing stray light in optical systems can now be replaced by microscopically textured metal surfaces. An application of these black surfaces to the Clementine star-tracker navigational system, which will be launched in early 1994 to examine the Moon, en route to intercept an asteroid, is detailed. Rugged black surfaces with Lambertian BRDF less than 10(exp -2) srad(sup -1) are critical for suppressing stray light in the star-tracker optical train. Previously available materials spall under launch vibrations to contaminate mirrors and lenses. Microtextured aluminum is nearly as dark, but much less fragile. It is made by differential ion beam sputtering, which generates light-trapping pores and cones slightly smaller than the wavelength to be absorbed. This leaves a sturdy but light-absorbing surface that can survive challenging conditions without generating debris or contaminants. Both seeded ion beams and plasma immersion (from ECR plasmas) extraction can produce these microscopic textures without fragile interfaces. Process parameters control feature size, spacing, and optical effects (THR, BRDF). Both broad and narrow absorption bands can be engineered with tuning for specific wavelengths and applications. Examples are presented characterized by FTIR in reflection librators (0.95 normal emissivity), heat rejection, and enhanced nucleate boiling.

Johnson, E. A.

1993-01-01

88

Low-Temperature Hydrothermal Deposits at the 71°N Vent Fields at the Arctic Mid-Ocean Ridge: Architecture, Microtextures, and Geochemistry  

NASA Astrophysics Data System (ADS)

Vast amounts of low-temperature siliceous Fe-deposits are formed distal to a high-temperature hydrothermal venting areas at the southwestern part of the Mohns Ridge. The low-temperature deposits occur as small yellow to rust coloured mounds and chimney-like structures along faults and fissures in the rift valley floor, for distances up to several kilometres. The mounds and chimneys have a stratified structure of millimetres to centimetres thick laminated layers that are alternating with centimetre sized hollow spaces. The individual layers have in general a highly porous microtexture of most frequently branching, twisted filaments resembling stalks of the iron-oxidising Gallionella sp, which have different thickness and colour of the mineral coating in the separate lamina. Other filamentous structures of apparently biogenic as well as abiotic origin are also present, and dominate in some lamina. The deposited material is loosely consolidated due to infilling of the interspaces between the filaments in a number of thin, discrete lamina. The filaments and the interstitial material have a similar composition of mainly FeO and silica, and electron diffraction reveal 2-line ferrihydrite. The REE composition of the siliceous ferrihydrite show a similar pattern to that of the basaltic crust, indicating that they formed from low-temperature hydrothermal fluids, derived from interactions between the basaltic crust and circulating seawater. Mn-accumulation is observed within lamina most commonly at the surface of deposits. Sediment particles of basaltic glass, high- temperature vent minerals like baryte, and diatoms within lamina that are present in discrete layers show that they sequentially formed at the surface of the deposits at the different stages of growth. This together with the architecture of alternating layers of biogenic filaments and hollow spaces suggest that the formation of these deposits were controlled by biofilms of Fe-oxidising microorganisms that developed at the interface between the reduced vent fluid and the surrounding oxidized seawater. Successive nucleation and precipitation of ferrihydrite and amorphous silica on the microbial stalks results in the formation of the mounds and chimneys.

Thorseth, I. H.; Pedersen, R. B.; Kruber, C.; Kosler, J.

2007-12-01

89

Chemical composition, plant secondary metabolites, and minerals of green and black teas and the effect of different tea-to-water ratios during their extraction on the composition of their spent leaves as potential additives for ruminants.  

PubMed

This study characterized the chemical composition of green and black teas as well as their spent tea leaves (STL) following boiling in water with different tea-to-water ratios. The green and black tea leaves had statistically similar (g/kg dry matter (DM), unless stated otherwise) DM (937 vs 942 g/kg sample), crude protein (240 vs 242), and ash (61.8 vs 61.4), but green tea had significantly higher (g/kg DM) total phenols (231 vs 151), total tannins (204 vs 133), condensed tannins (176 vs 101), and total saponins (276 vs 86.1) and lower neutral detergent fiber (254 vs 323) and acid detergent fiber (211 vs 309) than the black tea leaves. There was no significant difference between the green and black tea leaves for most mineral components except Mn, which was significantly higher in green tea leaves, and Na and Cu, which were significantly higher in black tea leaves. A higher tea-to-water ratio during extraction significantly reduced the loss of soluble compounds into water and hence yielded more nutrient-rich STL. On the basis of these analyses it appears that the green and black tea leaves alongside their STL have the potential for use as sources of protein, fiber, secondary metabolites, and minerals in ruminant diets. The presence of high levels of plant secondary metabolites in either tea leaves or their STL suggests that they may have potential for use as natural additives in ruminant diets. PMID:23621359

Ramdani, Diky; Chaudhry, Abdul Shakoor; Seal, Chris J

2013-05-22

90

Compositional and quantitative microtextural characterization of historic paintings by micro-X-ray diffraction and Raman microscopy.  

PubMed

This work shows the benefits of characterizing historic paintings via compositional and microtextural data from micro-X-ray diffraction (?-XRD) combined with molecular information acquired with Raman microscopy (RM) along depth profiles in paint stratigraphies. The novel approach was applied to identify inorganic and organic components from paintings placed at the 14th century Islamic University-Madrasah Yusufiyya-in Granada (Spain), the only Islamic University still standing from the time of Al-Andalus (Islamic Spain). The use of ?-XRD to obtain quantitative microtextural information of crystalline phases provided by two-dimensional diffraction patterns to recognize pigments nature and manufacture, and decay processes in complex paint cross sections, has not been reported yet. A simple Nasrid (14th century) palette made of gypsum, vermilion, and azurite mixed with glue was identified in polychromed stuccos. Here also a Christian intervention was found via the use of smalt, barite, hematite, Brunswick green and gold; oil was the binding media employed. On mural paintings and wood ceilings, more complex palettes dated to the 19th century were found, made of gypsum, anhydrite, barite, dolomite, calcite, lead white, hematite, minium, synthetic ultramarine blue, and black carbon. The identified binders were glue, egg yolk, and oil. PMID:21981573

Romero-Pastor, Julia; Duran, Adrian; Rodríguez-Navarro, Alejandro Basilio; Van Grieken, René; Cardell, Carolina

2011-11-15

91

On the Integration of Micro-textural and Crystal-Chemical Data With Magma Chamber Dynamics  

NASA Astrophysics Data System (ADS)

Many magmatic systems display a dual nature: compositional uniformity at the macro-to-meso scales, and great complexity of provenance, textures and age at the micro-to-meso scale. The integration of microtextural and crystal-chemical data with dynamic models and U-series age dating has tremendous potential to reveal the inner-workings of magmatic systems. However, a means of extending that crystal-scale data back to the largest scales is needed to evaluate the statistical significance of any conclusions drawn on the basis of a few crystals or thin sections. We will address two aspects of this: 1) The application of various statistical tools for the ordering of geochemical information to yield crystal populations who share distinct chemical environments and, 2) exemplify how dynamic templates of crystal dispersal and gathering, linked with kinetics, can reveal the timescales of the emergence, persistence and decay of regions of distinct chemical potential and the corresponding crystal-cargo. We will reprise Wallace and Bergantz (2005), which introduced the concept of the shared characteristics diagram as an organizational framework for crystal zoning that compares information from different phases and chemical tracers, in a common framework. It combines elements of cluster and structured data analysis to create a crystal phylogeny. This allows one recognize the progression of shared environments in the crystal-cargo at any level of statistical significance. We will then use numerical experiments of multiphase reacting flow to illustrate how various regions of distinct compositional character arise, and the controls on how that information is propagated to resident crystals. We will illustrate the diversity of outcomes that even simple open-systems produce, and how the ratio of the Damkohler (kinetic reaction time scale to diffusion time) and Peclet (convection time scale to diffusion time) numbers can be used to characterize both simple and competitive-consecutive reactions. This ratio of dimensionless numbers yields the characteristic time for reaction to that of convection. To first order, this allows one to explore and rationalize the interplay between equilibrium as dictated by the (changing) far-field environment at the largest scales, mediated by the kinetics at the crystal interface. Wallace, G., Bergantz, G.W., 2005, "Reconciling heterogeneity in crystal zoning data: An application of shared characteristic diagrams at Chaos Crags, Lassen Volcanic Center, California," Contrib. Min. Pet., v. 149, p. 98-112.

Bergantz, G. W.

2005-12-01

92

Mineral Animation  

NSDL National Science Digital Library

This site will help you to learn minerals! This module has two modes: an overview that takes you through some of the fundamentals of minerals and an interactive model that allows you to build your own virtual minerals.

2010-01-01

93

Quantitative Comparison of Microtexture in Near-Alpha Titanium Measured by Ultrasonic Scattering and Electron Backscatter Diffraction  

NASA Astrophysics Data System (ADS)

Ultrasonic backscattering and attenuation data were collected and processed using recently developed theoretical models to estimate the directionally dependent, volume-averaged size, and morphology of microtextured regions (MTRs) in a near-? Ti-8Al-1Mo-1V bar. The sample was also interrogated with electron backscatter diffraction from which MTR sizes were obtained by either manual segmentation and linear intercept analysis or fitting the spatial autocorrelation of similarly oriented c-axes to the geometrical autocorrelation function used in the scattering model. The results of the ultrasonic inversion were in good agreement with the EBSD measurements for the radial direction but were off by a factor of ~2.45 for the longitudinal direction. Reasons for the discrepancy were discussed and strategies to improve the agreement were made.

Pilchak, Adam L.; Li, Jia; Rokhlin, Stanislav I.

2014-09-01

94

Secondary amenorrhea  

MedlinePLUS

Amenorrhea - secondary; No periods - secondary; Absent periods - secondary; Absent menses - secondary; Absence of periods - secondary ... In addition to having no menstrual periods, other symptoms can ... gain or weight loss Discharge from the breast ( galactorrhea ) or ...

95

Minerals Yearbook  

NSDL National Science Digital Library

According to the Minerals Yearbook Web site, the US Geological Survey Minerals Information Team's mission is to collect, analyze, and disseminate information on the domestic and international supply of and demand for minerals and mineral materials essential to the US economy and national security. The yearbook reviews the mineral and material industries of the United States and foreign countries, contains statistical data on materials and minerals, and includes information on economic and technical trends and development. Volume I contains metals and minerals information, volume II US area reports, and volume III international reports. A lot of data is presented in the various documents; thankfully, the site is organized well and easy to navigate.

96

Ore Minerals  

NSDL National Science Digital Library

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

Dexter Perkins

97

The role of microtexture on the faceted fracture morphology in Ti–6Al–4V subjected to high-cycle fatigue  

Microsoft Academic Search

Microtextured regions (or macrozones) are commonly reported in titanium alloys and are believed to be related to fatigue life. Here, fractographic investigations are conducted on bimodal Ti–6Al–4V plate, including transmission electron microscopy to determine the mechanism of fatigue facet formation and electron backscattered diffraction to examine the underlying macrozone structures. It is found that macrozones oriented with their c-axis close

Ioannis Bantounas; David Dye; Trevor C Lindley

2010-01-01

98

Mineral Properties  

NSDL National Science Digital Library

You will learn about the properties that will help you identify minerals. If you closed your eyes and tasted different foods, you could probably determine what the foods are by noting properties such as saltiness or sweetness. You can also determine the identity of a mineral by noting different properties. Some properties that help us determine the identy of a mineral are: COLOR, ...

Wood, Mr.

2010-11-14

99

Reply to 'Commentary: Assessment of past infiltration fluxes through Yucca Mountain on the basis of the secondary mineral record-is it a viable methodology?', by Y.V. Dublyansky and S.Z. Smirnov  

SciTech Connect

Xu et al. (2003) presented results of a reaction-transport model for calcite deposition in the unsaturated zone at Yucca Mountain, and compared the model results to measured abundances in core from a surface-based borehole. Marshall et al. (2003) used the calcite distribution in the Topopah Spring Tuff to estimate past seepage into lithophysal cavities as an analog for seepage into the potential repository waste emplacement drifts at Yucca Mountain in southern Nevada (USA). Dublyansky and Smirnov (2005) wrote a commentary paper to Marshall et al. (2003) and Xu et al. (2003), containing two points: (1) questionable phenomenological model for the secondary mineral deposits and (2) inappropriate thermal boundary conditions. In this reply we address primarily the modeling approach by showing results of a sensitivity simulation regarding the effect of an elevated temperature history that approximates the temperature history inferred from fluid inclusions by Wilson et al. (2003). Modeled calcite abundances using the time-varying temperature history are similar to the results for the steady-state ambient temperature profile (Xu et al., 2003), and are still consistent with the measured abundances at the proposed repository horizon.

Sonnenthal, Eric; Xu, Tianfu; Bodvarrson, Gudmundur

2005-03-14

100

Extraterrestrial magnetic minerals  

NASA Astrophysics Data System (ADS)

Thermomagnetic and microprobe analyses are carried out and a set of magnetic characteristics are measured for 25 meteorites and 3 tektites from the collections of the Vernadsky Geological Museum of the Russian Academy of Sciences and Museum of Natural History of the North-East Interdisciplinary Science Research Institute, Far Eastern Branch of the Russian Academy of Sciences. It is found that, notwithstanding their type, all the meteorites contain the same magnetic minerals and only differ by concentrations of these minerals. Kamacite with less than 10% nickel is the main magnetic mineral in the studied samples. Pure iron, taenite, and schreibersite are less frequent; nickel, various iron spinels, Fe-Al alloys, etc., are very rare. These minerals are normally absent in the crusts of the Earth and other planets. The studied meteorites are more likely parts of the cores and lower mantles of the meteoritic parent bodies (the planets). Uniformity in the magnetic properties of the meteorites and the types of their thermomagnetic (MT) curves is violated by secondary alterations of the meteorites in the terrestrial environment. The sediments demonstrate the same monotony as the meteorites: kamacite is likely the only extraterrestrial magnetic mineral, which is abundant in sediments and associated with cosmic dust. The compositional similarity of kamacite in iron meteorites and in cosmic dust is due to their common source; the degree of fragmentation of the material of the parent body is the only difference.

Pechersky, D. M.; Markov, G. P.; Tsel'movich, V. A.; Sharonova, Z. V.

2012-07-01

101

Flourescent Minerals  

NSDL National Science Digital Library

This web page, hosted by Microscopy-UK, provides illustrations of flourescent minerals, each with accompanying text that shows how the color identifies the mineral. The site offers a brief explanation of flourescence and uses examples of calcite, willemite, and flourite to demonstrate this phenomenon. Numerous images, diagrams, and links are provided.

2009-01-28

102

Mineral Densities  

NSDL National Science Digital Library

Students are given cubic cell edge dimensions and asked to calculate mineral densities and vice versa. The final question of this homework assignment provides students with a mineral density and unit cell edge length in order to determine the number of formula units per cell.

103

Mineral Hunt  

NSDL National Science Digital Library

In this activity, learners search for various kinds of items made from minerals around their home or school, including toothpaste, wall paint, kitty litter, and bricks. The PDF contains a check off list as well as recommended sites for more information on minerals.

Science, Lawrence H.

2010-01-01

104

Industrial Minerals.  

ERIC Educational Resources Information Center

Discusses trends in and factors related to the production of industrial minerals during 1982, indicating that, as 1981 marked a downturn in production of industrial minerals, 1982 continued the trend with temporary and permanent cutbacks in mine and plant production. Includes highlights of several conferences/conference papers in this field.…

Brady, Lawrence L.

1983-01-01

105

RADIOACTIVE DEMONSTRATION OF FINAL MINERALIZED WASTE FORMS FOR HANFORD WASTE TREATMENT PLANT SECONDARY WASTE (WTP-SW) BY FLUIDIZED BED STEAM REFORMING (FBSR) USING THE BENCH SCALE REFORMER PLATFORM  

SciTech Connect

The U.S. Department of Energy’s Office of River Protection (ORP) is responsible for the retrieval, treatment, immobilization, and disposal of Hanford’s tank waste. Currently there are approximately 56 million gallons of highly radioactive mixed wastes awaiting treatment. A key aspect of the River Protection Project (RPP) cleanup mission is to construct and operate the Waste Treatment and Immobilization Plant (WTP). The WTP will separate the tank waste into high-level and low-activity waste (LAW) fractions, both of which will subsequently be vitrified. The projected throughput capacity of the WTP LAW Vitrification Facility is insufficient to complete the RPP mission in the time frame required by the Hanford Federal Facility Agreement and Consent Order, also known as the Tri-Party Agreement (TPA), i.e. December 31, 2047. Therefore, Supplemental Treatment is required both to meet the TPA treatment requirements as well as to more cost effectively complete the tank waste treatment mission. In addition, the WTP LAW vitrification facility off-gas condensate known as WTP Secondary Waste (WTP-SW) will be generated and enriched in volatile components such as {sup 137}Cs, {sup 129}I, {sup 99}Tc, Cl, F, and SO{sub 4} that volatilize at the vitrification temperature of 1150°C in the absence of a continuous cold cap (that could minimize volatilization). The current waste disposal path for the WTP-SW is to process it through the Effluent Treatment Facility (ETF). Fluidized Bed Steam Reforming (FBSR) is being considered for immobilization of the ETF concentrate that would be generated by processing the WTP-SW. The focus of this current report is the WTP-SW. FBSR offers a moderate temperature (700-750°C) continuous method by which WTP-SW wastes can be processed irrespective of whether they contain organics, nitrates, sulfates/sulfides, chlorides, fluorides, volatile radionuclides or other aqueous components. The FBSR technology can process these wastes into a crystalline ceramic (mineral) waste form. The mineral waste form that is produced by co-processing waste with kaolin clay in an FBSR process has been shown to be as durable as LAW glass. Monolithing of the granular FBSR product is being investigated to prevent dispersion during transport or burial/storage, but is not necessary for performance. A Benchscale Steam Reformer (BSR) was designed and constructed at the SRNL to treat actual radioactive wastes to confirm the findings of the non-radioactive FBSR pilot scale tests and to qualify the waste form for applications at Hanford. BSR testing with WTP SW waste surrogates and associated analytical analyses and tests of granular products (GP) and monoliths began in the Fall of 2009, and then was continued from the Fall of 2010 through the Spring of 2011. Radioactive testing commenced in 2010 with a demonstration of Hanford’s WTP-SW where Savannah River Site (SRS) High Level Waste (HLW) secondary waste from the Defense Waste Processing Facility (DWPF) was shimmed with a mixture of {sup 125/129}I and {sup 99}Tc to chemically resemble WTP-SW. Prior to these radioactive feed tests, non-radioactive simulants were also processed. Ninety six grams of radioactive granular product were made for testing and comparison to the non-radioactive pilot scale tests. The same mineral phases were found in the radioactive and non-radioactive testing. The granular products (both simulant and radioactive) were tested and a subset of the granular material (both simulant and radioactive) were stabilized in a geopolymer matrix. Extensive testing and characterization of the granular and monolith material were made including the following: ? ASTM C1285 (Product Consistency Test) testing of granular and monolith; ? ASTM C1308 accelerated leach testing of the radioactive monolith; ? ASTM C192 compression testing of monoliths; and ? EPA Method 1311 Toxicity Characteristic Leaching Procedure (TCLP) testing. The significant findings of the testing completed on simulant and radioactive WTP-SW are given below: ? Data indicates {sup 99}Tc, Re, Cs, and I

Crawford, C.; Burket, P.; Cozzi, A.; Daniel, G.; Jantzen, C.; Missimer, D.

2014-08-21

106

Clay Minerals  

SciTech Connect

Clay minerals are important components of the environment and are involved or implicated in processes such as the uptake of pollutants and the release of nutrients and as potential platforms for a number of chemical reactions. Owing to their small particle sizes (typically, on the order of microns or smaller) and mixing with a variety of other minerals and soil components, advanced characterization methods are needed to study their structures, dynamics, and reactivities. In this article, we describe the use of solid-state NMR methods to characterize the structures and chemistries of clay minerals. Early one-pulse magic-angle spinning (MAS) NMR studies of 27Al and 29Si have now been enhanced and extended with new studies utilizing advanced methodologies (such as Multiple Quantum MAS) as well as studies of less-sensitive nuclei. In additional work, the issue of reactivity of clay minerals has been addressed, including studies of reactive surface area in the environment. Utilizations of NMR-sensitive nuclides within the clay minerals themselves, and in molecules that react with speci?c sites on the clay mineral surfaces, have aided in understanding the reactivity of these complex aluminosilicate systems.

Mueller, Karl T.; Sanders, Rebecca L.; Washton, Nancy M.

2014-03-14

107

Compositional and Microtextural Analysis of Basaltic Feedstock Materials Used for the 2010 ISRU Field Tests, Mauna Kea, Hawaii  

NASA Astrophysics Data System (ADS)

This study seeks to understand variations in composition and texture of basaltic pyroclastic materials used in the 2010 International Lunar Surface Operation-In-Situ Resource Utilization Analogue Test (ILSO-ISRU) held on the slopes of Mauna Kea Volcano, Hawaii (1). The quantity and quality of resources delivered by ISRU depends upon the nature of the materials processed (2). We obtained a one-meter deep auger cuttings sample of a basaltic regolith at the primary site for feed stock materials being mined for the ISRU field test. The auger sample was subdivided into six, ~16 cm depth increments and each interval was sampled and characterized in the field using the Multispectral Microscopic Imager (MMI; 3) and a portable X-ray Diffractometer (Terra, InXitu Instruments, Inc.). Splits from each sampled interval were returned to the lab and analyzed using more definitive methods, including high resolution Powder X-ray Diffraction and Thermal Infrared (TIR) spectroscopy. The mineralogy and microtexture (grain size, sorting, roundness and sphericity) of the auger samples were determined using petrographic point count measurements obtained from grain-mount thin sections. NIH Image J (http://rsb.info.nih.gov/ij/) was applied to digital images of thin sections to document changes in particle size with depth. Results from TIR showed a general predominance of volcanic glass, along with plagioclase, olivine, and clinopyroxene. In addition, thin section and XRPD analyses showed a down core increase in the abundance of hydrated iron oxides (as in situ weathering products). Quantitative point count analyses confirmed the abundance of volcanic glass in samples, but also revealed olivine and pyroxene to be minor components, that decreased in abundance with depth. Furthermore, point count and XRD analyses showed a decrease in magnetite and ilmenite with depth, accompanied by an increase in Fe3+phases, including hematite and ferrihydrite. Image J particle analysis showed that the average grain size decreased down the depth profile. This decrease in average grain size and increase in hydrated iron oxides down hole suggests that the most favorable ISRU feedstock materials were sampled in the lower half-meter of the mine section sampled.

Marin, N.; Farmer, J. D.; Zacny, K.; Sellar, R. G.; Nunez, J.

2011-12-01

108

Industrial Minerals  

ERIC Educational Resources Information Center

The past year is seen as not particularly good for industrial minerals and for industry in general. Environmental concerns continued to trouble the industry with unacceptable asbestos concentrations and chlorofluorocarbon effects on ozone. A halting U.S. economy also affected industrial progress. (MA)

Bradbury, James C.

1978-01-01

109

Secondary parkinsonism  

MedlinePLUS

Secondary parkinsonism may be caused by health problems, including: Brain injury Diffuse Lewy body disease (a type of dementia ) Encephalitis HIV/AIDS Meningitis Multiple system atrophy Progressive ...

110

Mineral bioprocessing  

SciTech Connect

In the last 25 years, the introduction of biotechnological methods in hydrometallurgy has created new opportunities and challenges for the mineral processing industry. This was especially true for the production of metal values from mining wastes and low-and-complex-grade mineral resources, which were considered economically not amenable for processing by conventional extraction methods. Using bio-assisted heap, dump and in-situ leaching technologies, copper and uranium extractions gained their first industrial applications. The precious metal industries were the next to adopt the bio-preoxidation technique in the extraction of gold from refractory sulfide-bearing ores and concentrates. A variety of other bioleaching opportunities exist for nickel, cobalt, cadmium and zinc sulfide leaching. Recently developed bioremediation methods and biosorption technologies have shown a good potential for industrial applications to remove trace heavy metal and radionuclide concentrations from contaminated soils, and mining and processing effluents.

Torma, A.E.

1993-05-01

111

Mineral Commodities  

NSDL National Science Digital Library

This exercise introduces mineral commodities (elements). Students consider the elements aluminum, iron, copper, nickel, zinc, uranium, lead, gold, mercury and tin and match them with their definintions in a table. Then they use minable grade (minable weight percent) and normal crustal abundance (crustal weight percent) to calculate the concentration factor for several commodities to determine their economic minability. Students then graph their calculations and explain their trend.

Dexter Perkins

112

Rocks and Minerals  

NSDL National Science Digital Library

Rock Cycle Mineralogy 4 Kids Mineralogy 4 kids : rockin Internet site : the best place to learn about rocks and minerals Rock Cycle Map Rocks and Minerals Rocks and Minerals Pictures Rocks and Minerals Slide Show Rocks and Minerals Slide Show Earth Science Earth Science Uses for Minerals Metamorphic Rock Forming Sedimentary Rocks Observation ...

Richrigby

2010-02-23

113

[Secondary rhinoplasty].  

PubMed

Secondary rhinoplasty is very usual. Some patients are not satisfied by the previous surgery because the result is poor with obvious defaults but, sometimes, the result is good but the patient expects perfection. These two different situations will not lead to the same answer from the surgeon. Techniques of secondary rhinoplasty are the same than primary, but are often more difficult to perform because of scar tissue, retraction and loss of lining. The authors analyse the more frequent deformities in secondary rhinoplasty and the way they fix them. PMID:25213488

Duron, J-B; Nguyen, P S; Bardot, J; Aiach, G

2014-12-01

114

Secondary Headaches  

MedlinePLUS

... Migraine and Other Headaches Headache Journal - Public Site Art Gallery Art Gallery Support the AMF American Migraine Foundation The ... but there are usually clues in the medical history or examination to suggest secondary headache. Headache can ...

115

Peritonitis - secondary  

MedlinePLUS

... hole may be caused by a ruptured appendix, stomach ulcer, or perforated colon. It may also come from an injury, such as a gunshot or knife wound. Secondary peritonitis ... affect premature babies who have necrotizing enterocolitis .

116

[Secondary dyslipidemias].  

PubMed

Dyslipidemias rank among the most important preventabile factors of atherogenesis and its progression. This topic is increasingly being discussed as e.g. more than 50% of Slovak population die on atherosclerotic complications. According to etiology we distinguish primary dyslipidemias with strictly genetic background and secondary ones with origin in other disease or pathological state. Secondary dyslipidemias accompany various diseases, from common (endocrinopathies, renal diseases etc) to rare ones (thesaurismosis etc.) and represents one of symptoms of these diseases. Apart from particular clinical follow up of diagnosed dysipidemias, basic screening and secondary causes as well as treatment due to updated guidelines is recuired. In this review we present the most frequent dyslipidemias of clinical practice. PMID:22486289

Vargová, V; Pytliak, M; Mechírová, V

2012-03-01

117

Vitamins and Minerals  

MedlinePLUS

... gov . Nutrition for Everyone Nutrition Topics Share Compartir Vitamins and Minerals Vitamins are organic substances (made by plants or animals), ... humans absorb minerals from the plants they eat. Vitamins and minerals are nutrients that your body needs ...

118

Properties of Minerals  

NSDL National Science Digital Library

Students examine a number of key mineral properties and how they are displayed by different minerals. Mineral properties examined include crystal habit, cleavage, parting, fracture, hardness, tenacity, specific gravity, luster, color, and streak.

Dexter Perkins

119

Mineral Sands Down Under  

NSDL National Science Digital Library

This resource describes what mineral sands are, and discusses the heavy, dark-colored minerals that they contain (rutile, ilmenite, zircon, monazite). A map shows locations of mineral sands deposits in Australia.

120

Secondary hypoadrenalism  

Microsoft Academic Search

Secondary adrenal insufficiency (SAI) is a clinical disorder that results from hypothalamic or hypophyseal damage or from\\u000a prolonged administration of supraphysiological doses of glucocorticoids. Since glucocorticoids are widely used for a variety\\u000a of diseases, the prevalence of SAI is by far exceeding that of primary adrenal insufficiency. Although the presentation of\\u000a adrenal insufficiency may be insidious and difficult to recognize,

Giuseppe Reimondo; Silvia Bovio; Barbara Allasino; Massimo Terzolo; Alberto Angeli

2008-01-01

121

Earth's Mineral Evolution  

E-print Network

Earth's Mineral Evolution :: Astrobiology Magazine - earth science - evol...rth science evolution Extreme Life Mars Life Outer Planets Earth's Mineral Evolution Summary (Nov 14, 2008): New research. Display Options: Earth's Mineral Evolution Based on a CIW news release Mineral Kingdom Has Co

Downs, Robert T.

122

Calculating a Mineral's Density  

NSDL National Science Digital Library

Students will use the Density=Mass/Volume formula to calculate the density of an unknown mineral. By using water displacement and a triple beam balance students will collect measurements of volume and mass for an unknown mineral. With this data, they will calculate the mineral's density then identify the mineral based on calculated density.

Andrea Distelhurst

2011-10-05

123

Fungal degradation of calcium-, lead- and silicon-bearing minerals.  

PubMed

The aim of this study was to examine nutritional influence on the ability of selected filamentous fungi to mediate biogenic weathering of the minerals, apatite, galena and obsidian in order to provide further understanding of the roles of fungi as biogeochemical agents, particularly in relation to the cycling of metals and associated elements found in minerals. The impact of three organic acid producing fungi (Aspergillus niger, Serpula himantioides and Trametes versicolor) on apatite, galena and obsidian was examined in the absence and presence of a carbon and energy source (glucose). Manifestation of fungal weathering included corrosion of mineral surfaces, modification of the mineral substrate through transformation into secondary minerals (i.e. crystal formation) and hyphal penetration of the mineral substrate. Physicochemical interactions of fungal metabolites, e.g. H+ and organic acids, with the minerals are thought to be the primary driving forces responsible. All experimental fungi were capable of mineral surface colonization in the absence and presence of glucose but corrosion of the mineral surface and secondary mineral formation were affected by glucose availability. Only S. himantioides and T. versicolor were able to corrode apatite in the absence of glucose but none of the fungi were capable of doing so with the other minerals. In addition, crystal formation with galena was entirely dependent on the availability of glucose. Penetration of the mineral substrates by fungal hyphae occurred but this did not follow any particular pattern. Although the presence of glucose in the media appeared to influence positively the mineral penetrating abilities of the fungi, the results obtained also showed that some geochemical change(s) might occur under nutrient-limited conditions. It was, however, unclear whether the hyphae actively penetrated the minerals or were growing into pre-existing pores or cracks. PMID:15984571

Adeyemi, Ademola O; Gadd, Geoffrey M

2005-06-01

124

Mathematical Model for the Mineralization of Bone  

NASA Technical Reports Server (NTRS)

A mathematical model is presented for the transport and precipitation of mineral in refilling osteons. One goal of this model was to explain calcification 'halos,' in which the bone near the haversian canal is more highly mineralized than the more peripheral lamellae, which have been mineralizing longer. It was assumed that the precipitation rate of mineral is proportional to the difference between the local concentration of calcium ions and an equilibrium concentration and that the transport of ions is by either diffusion or some other concentration gradient-dependent process. Transport of ions was assumed to be slowed by the accumulation of mineral in the matrix along the transport path. ne model also mimics bone apposition, slowing of apposition during refilling, and mineralization lag time. It was found that simple diffusion cannot account for the transport of calcium ions into mineralizing bone, because the diffusion coefficient is two orders of magnitude too low. If a more rapid concentration gradient-driven means of transport exists, the model demonstrates that osteonal geometry and variable rate of refilling work together to produce calcification halos, as well as the primary and secondary calcification effect reported in the literature.

Martin, Bruce

1994-01-01

125

Mineral Spectroscopy Server  

NSDL National Science Digital Library

This server is primarily dedicated to providing information about color in minerals and access to data on mineral absorption in the visible, infrared, Raman and Mossbauer spectra. Both data coordinates and images of the spectra are available for selected minerals. Most data on the server were obtained in the Caltech mineral spectroscopy labs, but individuals throughout the world also contribute to this ever growing community resource. In addition to data files, the site provides an extensive list of references to papers on mineral optical spectroscopy. Citations are available sorted both by mineral name and by first authors of papers.

Rossman, George

126

Remnants of Melt Pools and Melt Films Associated with Dewatering of Nominally Anhydrous Minerals in Lower Crustal Granite  

NASA Astrophysics Data System (ADS)

Water locked in structural sites and in fluid inclusions in nominally anhydrous minerals in lower crustal granitoids may act as a flux for partial melting of these source rocks. Microtextural study of the 2.6 Ga Stevenson granite of the Athabasca Granulite Terrane of northern Saskatchewan shows that increasing intensity of deformation of the granite correlates with migration of water from within crystals to grain boundaries. Dark, ultrafine-grained, water-richer matrix material consisting of quartz, plagioclase, alkali feldspar and fine iron oxides are interpreted to be former melt films that resulted, at least in part, from fluxing by NAM-derived water. Melt films on the grain boundaries of plagioclase, potassium feldspar and quartz are approximately 20 microns wide. Melt pools are up to 100+ microns in diameter. Water in nominally anhydrous minerals has the potential to lower the solidus significantly enough to initiate partial melting in lower crustal granitoids at high ambient temperatures. 3000 ppm water in minerals that make up large volumes of crustal rocks (alkali feldspar, plagioclase feldspar, quartz) would lower the dry solidus of granite by 273oC at 1 GPa, for initiation of partial melting. Generation of small volumes of partial melt on grain boundaries may lead to further rock weakening and localization of further deformation.

Seaman, S. J.; Williams, M. L.

2013-12-01

127

Ohio Mineral Resources Management  

NSDL National Science Digital Library

Provides information about Mineral Resources in Ohio and management. Mine safety, oil and gas, coal mining, industrial minerals, and abandoned mined lands are related subheadings for the site. Good for finding history, factual reports, programs, regulations and policies.

2008-10-06

128

Minerals in Our Environment  

NSDL National Science Digital Library

What minerals are in your toothpaste? A pencil? A telephone? This interactive resource adapted from the U.S. Geological Survey illustrates the variety of minerals used in everyday items found in kitchens, bathrooms, offices, and yards.

Foundation, Wgbh E.

2005-12-17

129

Minerals in Sports  

NSDL National Science Digital Library

This series of articles describes the uses of mineral products in sports and sporting equipment. The site also explores minerals use in safety applications in the workplace. A series of reading material sheets are included in PDF format.

2011-07-06

130

Sedimentary and Related Minerals  

NSDL National Science Digital Library

In this three-part exercise, students study hand samples and thin sections of sedimentary minerals and rocks. Part one - Box of Rocks: Students examine a tray of Halides, Carbonates, Borates, and Clays and record their physical properties, composition, habit, and occurence. They note chemical and physical similarities and differences of the minerals. Part two - Definitions: Define a list of terms relevent to the lab. Part three - Minerals in Thin Section: Observe sedimentary minerals in thin section and answer questions about them.

Perkins, Dexter

131

Underground mineral extraction  

Microsoft Academic Search

A method for extracting an underground mineral such as coal, which avoids the need for sending personnel underground and which enables the mining of steeply pitched seams of the mineral. The method includes the use of a narrow vehicle which moves underground along the mineral seam and which is connected by pipes or hoses to water pumps at the surface

R. A. Frosch; C. G. Miller; J. B. Stephens

1980-01-01

132

Underground mineral extraction  

Microsoft Academic Search

A method was developed for extracting underground minerals such as coal, which avoids the need for sending personnel underground and which enables the mining of steeply pitched seams of the mineral. The method includes the use of a narrow vehicle which moves underground along the mineral seam and which is connected by pipes or hoses to water pumps at the

C. G. Miller; J. B. Stephens

1980-01-01

133

Minerals leasing for landowners  

SciTech Connect

This report delineates the provisions of the legal codes of the 13 Southeastern states relating to minerals leasing. The introduction explains land ownership and land leasing in terms of mineral rights, and describes the basic elements which a lease conveyance must contain to be valid. A checklist gives the terms which must be included in all mineral leases.

Not Available

1983-01-01

134

Metamorphic Rocks and Minerals  

NSDL National Science Digital Library

In this three-part exercise, students study hand samples and thin sections of important metamorphic rocks and minerals. Part one - Box of Rocks: Students examine trays of metamorphic rocks and minerals and record their physical properties, composition, and habit. They note chemical and physical similarities and differences and identify the rock samples and minerals they contain. Part two - Definitions: Define a list of terms relevent to the lab. Part three - Minerals in Thin Section: Observe minerals in thin section and answer questions about them.

Dexter Perkins

135

Rocks and Minerals  

NSDL National Science Digital Library

This unit provides younger students with an introduction to rocks and minerals. Topics include the definition of a mineral, the physical properties of minerals and how they are measured, and a discussion of quartz, the most basic silicate mineral and one of the most abundant minerals in the Earth's crust. The discussion on rocks includes the rock cycle, the three rock types (igneous, sedimentary, metamorphic), and how they are formed. There is also a vocabulary list and downloadable, printable worksheets for each major topic.

Medina, Philip

2010-09-08

136

Mineral particles, mineral fibers, and lung cancer  

SciTech Connect

The total fibrous and nonfibrous mineral content of the lung has been analyzed in a series of 14 men with lung cancer but no history of occupational dust exposure, and in a series of 14 control men matched for age, smoking history, and general occupational class. The lung cancer patients had an average of 525 +/- 369 X 10(6) exogenous mineral particles and 17.4 +/- 19.6 X 10(6) exogenous mineral fibers/g dry lung, while the controls had averages of 261 +/- 175 mineral particles and 4.7 +/- 3.2 X 10(6) mineral fibers/g dry lung. These differences are statistically significant for both particles and fibers. Kaolinite, talc, mica, feldspars, and crystalline silica comprised the majority of particles of both groups. Approximately 90% of the particles were smaller than 2 micron in diameter and approximately 60% smaller than 1 micron. In both groups, patients who had smoked more than 35 pack years had greater numbers of particles than patients who had smoked less than 35 pack years. It is concluded that, in this study, lungs from patients with lung cancer had statistically greater numbers of mineral particles and fibers than lungs from controls, and that smoking influences total long-term retention of particles from all sources.

Churg, A.; Wiggs, B.

1985-08-01

137

Uranium mineralization in southern Victoria Land, Antarctica  

SciTech Connect

For the past 10 antarctic field seasons, an airborne gamma-ray spectrometric survey has been conducted over widely separated parts of the continent. Localized accumulations of both primary and secondary uranium minerals have been discovered at several localities scattered along the Transantarctic Mountains from the Scott Glacier to northern Victoria Land. A number of highly significant radiation anomalies have been discovered in the area between the Koettlitz Glacier and the Pyramid Trough. The occurrences consist of pegmatite vein complexes which contain an association of primary uranium and thorium minerals. Of still greater significance is the fact that abundant secondary uranium minerals were found in association with the primary deposits, and they indicate clearly that uranium is geochemically mobile under the conditions imposed by the arid polar climate that now exists in southern Victoria Land. Preliminary results of a uranium analysis performed by neutron activation indicate a concentration of 0.12% uranium in a composite sample from the two veins. Even higher levels of thorium are present. The nature of the primary uranium mineralization is currently under investigation. Preliminary results are discussed.

Dreschhoff, G.A.M.; Zeller, E.J.

1986-01-01

138

Biological impact on mineral dissolution: application of the lichen model to understanding mineral weathering in the rhizosphere.  

PubMed

Microorganisms modify rates and mechanisms of chemical and physical weathering and clay growth, thus playing fundamental roles in soil and sediment formation. Because processes in soils are inherently complex and difficult to study, we employ a model based on the lichen-mineral system to identify the fundamental interactions. Fixed carbon released by the photosynthetic symbiont stimulates growth of fungi and other microorganisms. These microorganisms directly or indirectly induce mineral disaggregation, hydration, dissolution, and secondary mineral formation. Model polysaccharides were used to investigate direct mediation of mineral surface reactions by extracellular polymers. Polysaccharides can suppress or enhance rates of chemical weathering by up to three orders of magnitude, depending on the pH, mineral surface structure and composition, and organic functional groups. Mg, Mn, Fe, Al, and Si are redistributed into clays that strongly adsorb ions. Microbes contribute to dissolution of insoluble secondary phosphates, possibly via release of organic acids. These reactions significantly impact soil fertility. Below fungi-mineral interfaces, mineral surfaces are exposed to dissolved metabolic byproducts. Through this indirect process, microorganisms can accelerate mineral dissolution, leading to enhanced porosity and permeability and colonization by microbial communities. PMID:10097050

Banfield, J F; Barker, W W; Welch, S A; Taunton, A

1999-03-30

139

Constraining kinetic rates of mineral reactions using reactive transport models  

NASA Astrophysics Data System (ADS)

We use a reactive transport model to better understand results of experiments to obtain kinetic rates of mineral reactions in closed systems. Closed system experiments pose special challenges in that secondary minerals may form that modify the fluid composition evolution and may grow on the dissolving minerals thus armoring the surface. Even so, such closed system experiments provide critical data for what minerals would actually form in field applications and how coupled dissolution and precipitation mineral reactions are strongly linked. Comparing to experimental observations can test the reactive transport model, and the experimental observations can be better understood by comparing the results to the modeling. We apply a 0D end member of the model to understand the dissolution of single crystals of forsterite in a variety of settings (low pH, high pH, or NaHCO3 initial fluids, at 100 C and 1 bar, or 200 C and 150 bar). Depending on the initial conditions, we observe the precipitation of talc, brucite, amorphous silica, chrysotile, or magnesite, in various combinations. We compare simulation results to fluid compositions and the presence of secondary minerals experimentally sampled at various times. Insight from the simulations helped create an inverse model to extract the rates of forsterite dissolution and to create a simple forward model useful for exploring the influence of system size, secondary mineral surface areas, etc. Our reactive transport model allows secondary minerals to armor the forsterite surface, which can strongly decrease the dissolution rate as the system evolves. Tuning our model with experimentally derived rates and assuring relevant processes are included so as to reproduce experimental observations is necessary before upscaling to heterogeneous field conditions. The reactive transport model will be used for field-scale sequestration simulations and coupled with a geomechanical model that includes the influence of deformation.

Bolton, E. W.; Wang, Z.; Ague, J.; Bercovici, D.; Cai, Z.; Karato, S.; Oristaglio, M. L.; Qiu, L.

2012-12-01

140

Minerals in Our Environment  

NSDL National Science Digital Library

Minerals are all around us. They're in our kitchens and bathrooms, our classrooms and school buildings, and our cars and bicycles. This interactive feature lets users discover which minerals are found in items they probably encounter every day. Rolling the cursor over items in an illustrated room accesses pop-ups that describe what mineral products may be found in them. A background essay and list of discussion questions are also provided.

2008-01-01

141

Mineral Industry Surveys  

NSDL National Science Digital Library

The US Geological Surveys Mineral Industry Survey's Web site provides "periodic on-line statistical and economic publications designed to provide timely statistical data on production, distribution, stocks, and consumption of significant mineral commodities." Visitors to the site will find an alphabetical listing of minerals that includes everything from Aluminum, Antimony, Arsenic, and Asbestos, to Zeolite, Zinc, and Zirconium. Once clicked, a brief description of the mineral is provided along with links to yearly information publications as well as special publications such as its historical statistics, other agency links, contact information, and more.

142

Reagan issues mineral policy  

NASA Astrophysics Data System (ADS)

The National Materials and Minerals Program plan and report that President Reagan sent to Congress on April 5 aims to ‘decrease America's minerals vulnerability’ while reducing future dependence on potentially unstable foreign sources of minerals. These goals would be accomplished by taking inventory of federal lands to determine mineral potential; by meeting the stockpile goals set by the Strategic and Critical Material Stockpiling Act; and by establishing a business and political climate that would encourage private-sector research and development on minerals.Now that the Administration has issued its plan, the Subcommittee on Mines and Mining of the House Committee on Interior and Insular Affairs will consider the National Minerals Security Act (NMSA), which was introduced 1 year ago by subcommittee chairman Jim Santini (D-Nev.) [Eos, May 19, 1981, p. 497]. The bill calls for establishing a three-member White-House-level council to coordinate the development of a national minerals policy; amending tax laws to assist the mining industry to make capital investments to locate and produce strategic materials; and creating a revolving fund for the sale and purchase of strategic minerals. In addition, the NMSA bill would allow the secretary of the interior to make previously withdrawn public lands available for mineral development. The subcommittee will hold a hearing on the Administration's plan on May 11. Interior Secretary James Watt has been invited to testify.

143

USGS: Mineral Resources Program  

NSDL National Science Digital Library

"The Mineral Resources Program funds science to provide and communicate current, impartial information on the occurrence, quality, quantity, and availability of mineral resources." This website divides the mineral resource information, project descriptions, and products for the United States into four main regional categories: Eastern, Central, Western, and Alaska. Researchers can discover new grant opportunities and can obtain access to the National Geochemical Survey's database. Students and educators can find statistics and information on how the United State's supply-and-demand for minerals and materials affects the economy, security, and environment.

144

Minerals by Chemical Composition  

NSDL National Science Digital Library

This interactive periodic table displays a listing of minerals by element, sorted by percent of the element. Clicking on a symbol on the table leads users to information on the element (atomic mass and number, name origin, year of discovery, and a brief description), and to a table listing each mineral known to contain the element in decreasing order by percentage. Each mineral name in the table is linked to additional information on the mineral, such as formula and composition, images, crystallography, physical properties, and many others.

145

Mineral Classification Exercise  

NSDL National Science Digital Library

This exercise is designed to help students think about the properties of minerals that are most useful for mineral classification and identification. Students are given a set of minerals and asked to come up with a hierarchical classification scheme (a "key") that can be used to identify different mineral species. They compare their results with the products of other groups. They test the various schemes by applying them to unknown samples. While doing this exercise, the students develop observational and interpretational skill. They also begin to think about the nature of classification systems.

Perkins, Dexter

146

Canadian Minerals Yearbook  

NSDL National Science Digital Library

Part of Natural Resources Canada Minerals and Metals Sector, the Canadian Minerals Yearbook Web site provides mineral industry information from 1994 to 2001. Downloadable files from each year include a Year in Review, Reserves of Selected Major Metals, Recent Production Decisions, and a Mineral and Metal Commodity Review. An example of the information provided comes from the 2001 Review: "In 2000, Canadian reserves of copper, nickel, lead, zinc, molybdenum, silver and gold decreased because there were no decisions to bring new mines into production and the amount of new ore discovered at existing mining operations was insufficient to replace the quantity of ore that was mined during the year."

2001-01-01

147

Carbon dioxide sequestration by mineral carbonation  

SciTech Connect

Concerns about global warming caused by the increasing concentration of carbon dioxide and other greenhouse gases in the earth’s atmosphere have resulted in the need for research to reduce or eliminate emissions of these gases. Carbonation of magnesium and calcium silicate minerals is one possible method to achieve this reduction. It is possible to carry out these reactions either in situ (storage underground and subsequent reaction with the host rock to trap CO2 as carbonate minerals) or ex situ (above ground in a more traditional chemical processing plant). Research at the Department of Energy’s Albany Research Center has explored both of these routes. This paper will explore parameters that affect the direct carbonation of magnesium silicate minerals serpentine (Mg3Si2O5(OH)4) and olivine (Mg2SiO4) to produce magnesite (MgCO3), as well as the calcium silicate mineral, wollastonite (CaSiO3), to form calcite (CaCO3). The Columbia River Basalt Group is a multi-layered basaltic lava plateau that has favorable mineralogy and structure for storage of CO2. Up to 25% combined concentration of Ca, Fe2+, and Mg cations could react to form carbonates and thus sequester large quantities of CO2. Core samples from the Columbia River Basalt Group were reacted in an autoclave for up to 2000 hours at temperatures and pressures to simulate in situ conditions. Changes in core porosity, secondary minerals, and solution chemistry were measured.

Gerdemann, Stephen J.; Dahlin David C.; O'Connor William K.; Penner Larry R.

2003-11-01

148

Primary and Secondary Sources  

NSDL National Science Digital Library

Use these links to learn more about primary and secondary sources. 1. Explore the links below to learn about primary and secondary sources. When you have finished, you should be able to: Tell the difference between primary and secondary sources. Give at least three examples of primary sources and three examples of secondary sources. Explain why primary sources are important in research. Examples of Primary Sources Examples of Primary and Secondary Sources on the Same Topic Genres/Formats of Primary Sources 2. ...

Albion Middle School Library--Mrs. Bates

2010-01-23

149

Rocks & Mineral Solitaire  

NSDL National Science Digital Library

This site features a solitaire game designed to help students identify rocks and minerals. The card game would be used by the students after class discussions about rock/mineral categories and classifications. Several sets of the card game, managed by the teacher, would be available for the students. The cards could be used both during and after class.

Catania, Andrea J.; Education, San D.

150

Vitamin and mineral requirements  

E-print Network

Vitamin and mineral requirements in human nutrition Second edition Please go to the Table/WHO Expert Consultation on Human Vitamin and Mineral Requirements (1998 : Bangkok, Thailand). Vitamin, 21­30 September 1998. 1.Vitamins -- standards 2.Micronutrients -- standards 3.Trace elements

Laughlin, Robert B.

151

Vitamins, Minerals, and Mood  

ERIC Educational Resources Information Center

In this article, the authors explore the breadth and depth of published research linking dietary vitamins and minerals (micronutrients) to mood. Since the 1920s, there have been many studies on individual vitamins (especially B vitamins and Vitamins C, D, and E), minerals (calcium, chromium, iron, magnesium, zinc, and selenium), and vitamin-like…

Kaplan, Bonnie J.; Crawford, Susan G.; Field, Catherine J.; Simpson, J. Steven A.

2007-01-01

152

VITAMINS AND MINERALS  

NSDL National Science Digital Library

DESK Standard: Specify key vitamins and minerals and their functions. . DATES: You can begin this activity on May 21. You should complete it by May 25. OBJECTIVE: A healthy body needs vitamins and minerals. You\\'ve probably heard these words before, but do you really know what they mean? This activity will help you better understand the ...

Hughes, Mr.

2006-03-05

153

Digging into Minnesota Minerals.  

ERIC Educational Resources Information Center

This publication presents students with facts about geology and several learning activities. Topics covered include rocks and minerals, volcanoes and earthquakes, fossils, exploration geology, mining in Minnesota, environmental issues related to mining, mineral uses, mining history, and the geology of Minnesota's state parks. A geologic timetable…

Minnesota State Dept. of Natural Resources, St. Paul.

154

The Miner's Canary  

ERIC Educational Resources Information Center

Miners used canaries as early warning signals: when a canary gasped for breath, the miners knew there was a problem with the atmosphere in the mine. The experience of people of color in higher education can be used similarly as a diagnostic tool.

Guinier, Lani

2005-01-01

155

Mineral Image Index  

NSDL National Science Digital Library

This image gallery provides pictures of thousands of mineral specimens, arranged alphabetically. For each specimen, a thumbnail and a larger image are provided. Other information includes a brief description of the specimen being shown, scale bar (when available), locality data, and a link to additional information on the mineral.

156

Rocks and Minerals  

NSDL National Science Digital Library

This description of rocks and minerals includes representatives of all three major groups: igneous, sedimentary, and metamorphic. Users can access introductory information about the three major rock types and the minerals that form them. A simple rock classification chart is included, with embedded links to a glossary and more detailed material for advanced learners.

157

Minerals, Crystals and Gems  

NSDL National Science Digital Library

This module introduces students to minerals, crystals, and gems by using pictures and discussions of some of the extraordinary specimens residing in the collections of the Smithsonian Institution. It includes three lessons in which they draw pictures of specimens, grow their own crystals of magnesium sulfate, and perform a scavenger hunt in which they look for minerals in commonly used objects and products.

158

Rocks and Minerals  

NSDL National Science Digital Library

This guide provides introductory information about rocks and minerals. Topics include some of the common rock-forming minerals, what rocks are made of, and where they come from (the three basic rock types). There are descriptions and photos of igneous, sedimentary, and metamorphic rocks, a glossary, and a simple identification chart that has links to websites with additional information.

2010-11-08

159

Atoms and Minerals  

NSDL National Science Digital Library

This site contains 23 questions on the topic of atoms and minerals, which covers mineral types and characteristics. This is part of the Principles of Earth Science course at the University of South Dakota. Users submit their answers and are provided immediate verification.

Heaton, Timothy

160

Ion beam microtexturing of surfaces  

NASA Technical Reports Server (NTRS)

Some recent work in surface microtecturing by ion beam sputtering is described. The texturing is accomplished by deposition of an impurity onto a substrate while simultaneously bombarding it with an ion beam. A summary of the theory regarding surface diffusion of impurities and the initiation of cone formation is provided. A detailed experimental study of the time-development of individual sputter cones is described. A quasi-liquid coating was observed that apparently reduces the sputter rate of the body of a cone compared to the bulk material. Experimental measurements of surface diffusion activation energies are presented for a variety of substrate-seed combinations and range from about 0.3 eV to 1.2 eV. Observations of apparent crystal structure in sputter cones are discussed. Measurements of the critical temperature for cone formation are also given along with a correlation of critical temperature with substrate sputter rate.

Robinson, R. S.

1981-01-01

161

Underground mineral extraction  

NASA Technical Reports Server (NTRS)

A method was developed for extracting underground minerals such as coal, which avoids the need for sending personnel underground and which enables the mining of steeply pitched seams of the mineral. The method includes the use of a narrow vehicle which moves underground along the mineral seam and which is connected by pipes or hoses to water pumps at the surface of the Earth. The vehicle hydraulically drills pilot holes during its entrances into the seam, and then directs sideward jets at the seam during its withdrawal from each pilot hole to comminute the mineral surrounding the pilot hole and combine it with water into a slurry, so that the slurried mineral can flow to a location where a pump raises the slurry to the surface.

Miller, C. G.; Stephens, J. B.

1980-01-01

162

USGS: Energy & Minerals  

NSDL National Science Digital Library

The Energy and Minerals Mission Area of the United States Geological Survey (USGS) "conducts research and assessments on the location, quantity, and quality of material and energy resources, including the economic and environmental effects of resource extraction and use." Visitors to the site can click on thematic sections such as Energy Resources and Mineral Resources. Each of these areas contains information about each program, along with fact sheets, databases, and detailed geospatial maps. The Program News area contains links to documents such as "Understanding the Global Distribution of Nonfuel Mineral Resources" and a host of summary documents on mineral commodities. Finally, the site is rounded out by the Mineral Resources Products area. Here, visitors can look into hundreds of statistical reports, bulletins, and data sets intended for scientists, journalists, and members of the general public.

2013-06-20

163

Kiwifruit and mineral nutrition.  

PubMed

Dietary minerals are essential nutrients that drive key cellular and physiological functions. Each mineral is absorbed in the gut via unique, complex pathways that can involve a cascade of receptors and binding proteins. Foods can both provide dietary minerals and contain components that impact the bioavailability of minerals in the digestive system. Kiwifruit exceeds most other fruits in its content of key micronutrients including potassium, phosphorus, magnesium, calcium, iron, and folate. It also contains exceedingly high levels of ascorbic acid, which increases the bioavailability of nonheme iron and can impact on calcium absorption. Recent research in cells, animals, and humans has demonstrated that kiwifruit, particularly the gold variety, can increase the uptake and retention of the essential dietary minerals iron, calcium, phosphorus, and magnesium. PMID:23394991

Wolber, Frances M; Beck, Kathryn L; Conlon, Cathryn A; Kruger, Marlena C

2013-01-01

164

Mineral facilities of Europe  

USGS Publications Warehouse

This map displays over 1,700 records of mineral facilities within the countries of Europe and western Eurasia. Each record represents one commodity and one facility type at a single geographic location. Facility types include mines, oil and gas fields, and plants, such as refineries, smelters, and mills. Common commodities of interest include aluminum, cement, coal, copper, gold, iron and steel, lead, nickel, petroleum, salt, silver, and zinc. Records include attributes, such as commodity, country, location, company name, facility type and capacity (if applicable), and latitude and longitude geographical coordinates (in both degrees-minutes-seconds and decimal degrees). The data shown on this map and in table 1 were compiled from multiple sources, including (1) the most recently available data from the U.S. Geological Survey (USGS) Minerals Yearbook (Europe and Central Eurasia volume), (2) mineral statistics and information from the USGS Minerals Information Web site (http://minerals.usgs.gov/minerals/pubs/country/europe.html), and (3) data collected by the USGS minerals information country specialists from sources, such as statistical publications of individual countries, annual reports and press releases of operating companies, and trade journals. Data reflect the most recently published table of industry structure for each country at the time of this publication. Additional information is available from the country specialists listed in table 2.

Almanzar, Francisco; Baker, Michael S.; Elias, Nurudeen; Guzman, Eric

2010-01-01

165

43 CFR 19.8 - Prospecting, mineral locations, mineral patents, and mineral leasing within National Forest...  

Code of Federal Regulations, 2010 CFR

...patents, and mineral leasing within National Forest Wilderness. 19.8 Section 19.8...patents, and mineral leasing within National Forest Wilderness. Regulations issued under...and mineral leasing within National Forest Wilderness are contained in parts...

2010-10-01

166

43 CFR 19.8 - Prospecting, mineral locations, mineral patents, and mineral leasing within National Forest...  

Code of Federal Regulations, 2012 CFR

...patents, and mineral leasing within National Forest Wilderness. 19.8 Section 19.8...patents, and mineral leasing within National Forest Wilderness. Regulations issued under...and mineral leasing within National Forest Wilderness are contained in parts...

2012-10-01

167

43 CFR 19.8 - Prospecting, mineral locations, mineral patents, and mineral leasing within National Forest...  

Code of Federal Regulations, 2011 CFR

...patents, and mineral leasing within National Forest Wilderness. 19.8 Section 19.8...patents, and mineral leasing within National Forest Wilderness. Regulations issued under...and mineral leasing within National Forest Wilderness are contained in parts...

2011-10-01

168

43 CFR 19.8 - Prospecting, mineral locations, mineral patents, and mineral leasing within National Forest...  

...patents, and mineral leasing within National Forest Wilderness. 19.8 Section 19.8...patents, and mineral leasing within National Forest Wilderness. Regulations issued under...and mineral leasing within National Forest Wilderness are contained in parts...

2014-10-01

169

43 CFR 19.8 - Prospecting, mineral locations, mineral patents, and mineral leasing within National Forest...  

Code of Federal Regulations, 2013 CFR

...patents, and mineral leasing within National Forest Wilderness. 19.8 Section 19.8...patents, and mineral leasing within National Forest Wilderness. Regulations issued under...and mineral leasing within National Forest Wilderness are contained in parts...

2013-10-01

170

Minerals and mine drainage  

SciTech Connect

This paper provides a review of literature published in 1995 on the subject of wastewater related to minerals and mine drainage. Topics covered include: environmental regulations and impacts; and characterization, prevention, treatment and reclamation. 65 refs.

Thomson, B.M. [Univ. of New Mexico, Albuquerque, NM (United States); Turney, W.R. [Los Alamos National Lab., NM (United States)

1996-11-01

171

Minerals and mine drainage  

SciTech Connect

This paper briefly lists the various literature reviews dealing with (a) Environmental regulations and impacts, and (b) Characterization, prevention, treatment and reclamation, with respect to minerals and mine drainage. 47 refs.

Thomson, B.M. [Univ. of New Mexico, Albuquerque, NM (United States); Turney, W.R. [Univ. of New Mexico, Albuquerque, NM (United States)]|[Los Alamos National Lab., NM (United States)

1995-06-01

172

Ken's Fluorescent Minerals  

NSDL National Science Digital Library

This web site provides photos of fluorescent minerals photographed under long wave (LW) or short wave (SW) ultraviolet light. Links to additional resources, and a list of books and information sources are also included.

Kenneth Colosky

173

Defining reactive sites on hydrated mineral surfaces: Rhombohedral carbonate minerals  

E-print Network

on the structural properties of the hydrated (10.4) cleav- age calcite surface, this mineral was chosenDefining reactive sites on hydrated mineral surfaces: Rhombohedral carbonate minerals Adria properties of mineral surfaces, their construct is sometimes incompatible with fundamental chemical and

Long, Bernard

174

36 CFR 293.14 - Mineral leases and mineral permits.  

Code of Federal Regulations, 2010 CFR

...Property 2 2010-07-01 2010-07-01 false Mineral leases and mineral permits. 293.14 Section 293.14 Parks...AGRICULTURE WILDERNESS-PRIMITIVE AREAS § 293.14 Mineral leases and mineral permits. (a) All laws...

2010-07-01

175

Mineral prospecting manual  

SciTech Connect

This book: provides the mineral prospector with a series of essential guidelines for the work he must do and the precautions he will have to take; shows how successful mineral prospecting is dependent on the critical examination of technical, economic and financial data examined during each phase of the operation; and provides information on physical preparations for prospecting, hammer prospecting, prospecting in coastal formations, drilling techniques and equipment, sampling procedures, and current research methods (e.g.: remote sensing and geochemistry).

Chaussier, J.B.; Morer, J.

1986-01-01

176

The mineral economy of Brazil--Economia mineral do Brasil  

USGS Publications Warehouse

This study depicts the Brazilian government structure, mineral legislation and investment policy, taxation, foreign investment policies, environmental laws and regulations, and conditions in which the mineral industry operates. The report underlines Brazil's large and diversified mineral endowment. A total of 37 mineral commodities, or groups of closely related commodities, is discussed. An overview of the geologic setting of the major mineral deposits is presented. This report is presented in English and Portuguese in pdf format.

Gurmendi, Alfredo C.; Barboza, Frederico Lopes; Thorman, Charles H.

1999-01-01

177

Measuring the Hardness of Minerals  

ERIC Educational Resources Information Center

The author discusses Moh's hardness scale, a comparative scale for minerals, whereby the softest mineral (talc) is placed at 1 and the hardest mineral (diamond) is placed at 10, with all other minerals ordered in between, according to their hardness. Development history of the scale is outlined, as well as a description of how the scale is used…

Bushby, Jessica

2005-01-01

178

Isotopic bone mineralization rates in maintenance dialysis patients  

SciTech Connect

The expanding pool model of radiocalcium kinetics has been used in 13 maintenance dialysis patients to measure bone mineralization rate. No difficulties were met in applying the data to the model, and values for the bone mineralization rate ranged from 0.0 to 2.0 mmol/kg Ca++ per day. The bone histology obtained at the time of the study showed a correlation between the degree of secondary hyperparathyroidism and the bone mineralization rate, with low values of the latter occurring in atypical osteomalacia (two patients) or inactive-looking bone (one patient) and raised values in seven patients. The plasma alkaline phosphatase and immunoassayable parathyroid hormone levels each correlated significantly with the bone mineralization rate. These findings suggest that the technique is valid when applied to hemodialysis patients and provides quantitative information about skeletal calcium metabolism in different types of renal bone disease.

Cochran, M.; Stephens, E.

1983-09-01

179

Problem of secondary porosity: Frio Formation (Oligocene), Texas Gulf Coast  

Microsoft Academic Search

Secondary porosity, formed by the dissolution of both carbonate and silicate minerals, especially K-feldspars, is widely developed in sandstones of the Frio Formation (Oligocene) in the Texas Gulf Coast. CO2 produced by decarboxylation of organic matter is commonly suggested as the acid required for dissolution. Material balance calculations indicate that CO2 produced by decarboxylation of organic matter in Frio Formation

Paul D. Lundegard; Lynton S. Land; William E. Galloway

1984-01-01

180

The JMU Mineral Museum - Observing Physical Properties of Minerals  

NSDL National Science Digital Library

Mineral museums provide a resourse for students to explore beautiful examples of minerals. During the exploration process, they can also apply or reinforce visual observation skills they have learned in lab. The James Madison University Mineral Museum (http://csm.jmu.edu/minerals/) provides educational opportunities for both introductory geology and earth science courses as well as advanced major. In this exercise, students have possibly their first opportunity to enjoy the wonderous world of minerals in an exhilerating display. During the exploration process, students are provided a reinforcment of visual observation skills previously experienced in lab and an introduction to mineral names and classifications.

Kearns, Cynthia A.

181

Minerals Management Board  

NASA Astrophysics Data System (ADS)

The five-member Minerals Management Board, headed by Undersecretary of the Interior Donald Paul Hodel, supervises and oversees the operations of the Minerals Management Service, according to the January 19 order by Secretary of the Interior Watt. The board is charged with developing the ‘appropriate policy and guidelines to implement the approved recommendations and findings of the Commission on Fiscal Accountability of the Nation's Energy Resources and monitor program activities directed toward the improvement of the royalty management program.’ Also on the board are Daniel Miller, Assistant Secretary of the Interior for Energy and Minerals; Kenneth L. Smith, Assistant Secretary for Indian Affairs; Garrey E. Carruthers, Assistant Secretary for Land and Water Resources; and J. Robinson West, Assistant Secretary for Policy, Budget, and Administration.

182

Microbially mediated mineral carbonation  

NASA Astrophysics Data System (ADS)

Mineral carbonation involves silicate dissolution and carbonate precipitation, which are both natural processes that microorganisms are able to mediate in near surface environments (Ferris et al., 1994; Eq. 1). (Ca,Mg)SiO3 + 2H2CO3 + H2O ? (Ca,Mg)CO3 + H2O + H4SiO4 + O2 (1) Cyanobacteria are photoautotrophs with cell surface characteristics and metabolic processes involving inorganic carbon that can induce carbonate precipitation. This occurs partly by concentrating cations within their net-negative cell envelope and through the alkalinization of their microenvironment (Thompson & Ferris, 1990). Regions with mafic and ultramafic bedrock, such as near Atlin, British Columbia, Canada, represent the best potential sources of feedstocks for mineral carbonation. The hydromagnesite playas near Atlin are a natural biogeochemical model for the carbonation of magnesium silicate minerals (Power et al., 2009). Field-based studies at Atlin and corroborating laboratory experiments demonstrate the ability of a microbial consortium dominated by filamentous cyanobacteria to induce the precipitation of carbonate minerals. Phototrophic microbes, such as cyanobacteria, have been proposed as a means for producing biodiesel and other value added products because of their efficiency as solar collectors and low requirement for valuable, cultivable land in comparison to crops (Dismukes et al., 2008). Carbonate precipitation and biomass production could be facilitated using specifically designed ponds to collect waters rich in dissolved cations (e.g., Mg2+ and Ca2+), which would allow for evapoconcentration and provide an appropriate environment for growth of cyanobacteria. Microbially mediated carbonate precipitation does not require large quantities of energy or chemicals needed for industrial systems that have been proposed for rapid carbon capture and storage via mineral carbonation (e.g., Lackner et al., 1995). Therefore, this biogeochemical approach may represent a readily implemented and economically efficient alternative to other technologies currently under development for mineral sequestration. Dismukes GC, Carrieri D, Bennette N, Ananyev GM, Posewitz MC (2008) Aquatic phototrophs: efficient alternatives to land-based crops for biofuels. Current Opinion in Biotechnology, 19, 235-240. Ferris FG, Wiese RG, Fyfe WS (1994) Precipitation of carbonate minerals by microorganisms: Implications of silicate weathering and the global carbon dioxide budget. Geomicrobiology Journal, 12, 1-13. Lackner KS, Wendt CH, Butt DP, Joyce EL, Jr., Sharp DH (1995) Carbon dioxide disposal in carbonate minerals. Energy, 20, 1153-1170. Power IM, Wilson SA, Thom JM, Dipple GM, Gabites JE, Southam G (2009) The hydromagnesite playas of Atlin, British Columbia, Canada: A biogeochemical model for CO2 sequestration. Chemical Geology, 206, 302-316. Thompson JB, Ferris FG (1990) Cyanobacterial precipitation of gypsum, calcite, and magnesite from natural alkaline lake water. Geology, 18, 995-998.

Power, I. M.; Wilson, S. A.; Dipple, G. M.; Southam, G.

2010-12-01

183

DIAMOND SECONDARY EMITTER  

SciTech Connect

We present the design and experimental progress on the diamond secondary emitter as an electron source for high average power injectors. The design criteria for average currents up to 1 A and charge up to 20 nC are established. Secondary Electron Yield (SEY) exceeding 200 in transmission mode and 50 in emission mode have been measured. Preliminary results on the design and fabrication of the self contained capsule with primary electron source and secondary electron emitter will also be presented.

BEN-ZVI, I.; RAO, T.; BURRILL, A.; CHANG, X.; GRIMES, J.; RANK, J.; SEGALOV, Z.; SMEDLEY, J.

2005-10-09

184

Skeletal remineralization after surgery for primary and secondary hyperparathyroidism.  

PubMed

Bone mineral was measured by photon absorptiometry before and after parathyroid surgery in patients with primary or secondary hyperparathyroidism (HPT). The mean bone mineral density of lumbar vertebrae was 0.82 +/- 0.04 (SEM) gm/cm2 in primary HPT (n = 7) and 0.86 +/- 0.05 gm/cm2 in secondary HPT (n = 11). These values are significantly lower than for age-matched normal subjects. After successful parathyroid surgery, the bone mass of the distal radius and lumbar vertebrae increased by approximately 10% within 3 months after operation and then remained stable during the first postoperative year. In conclusion, parathyroid surgery is followed by a significant increase of bone mass in primary and secondary HPT. The substantial increase in bone mass in parts of the skeleton consisting predominantly of trabecular bone, as well as in sites with predominantly cortical bone, indicates that remineralization after operation involves a generalized increase in bone mass. PMID:2300893

Abugassa, S; Nordenström, J; Eriksson, S; Möllerström, G; Alveryd, A

1990-02-01

185

Rocks and Minerals Of Kentucky  

NSDL National Science Digital Library

The Kentucky rocks highlighted on this website are chiefly sedimentary, such as limestone and dolostone, since sedimentary rocks cover approximately 99 percent of the state. You will find an extensive list of minerals and mineral groups, such as oxides or halides, and mineral property descriptions that cover hardness, cleavage, color, crystal system, streak, and more. These properties are also discussed in relation to their use in identifying unknown minerals. Igneous and metamorphic rocks are covered in relation to gold and silver deposits, and the legend of the Jonathon Swift Silver mines. Information on Kentucky's state rock and mineral, museums, rock clubs, and mineral deposits are included.

186

The Physical Characteristics of Minerals  

NSDL National Science Digital Library

Offered by Amethyst Galleries, Inc. (an online minerals store), the Physical Characteristics of Minerals Web site offers a detailed description of how minerals are identified. Each page gives good information and examples of a particular characteristic (e.g, color, hardness, cleavage, feel, and taste). Also, on the first page are links to dozens of minerals that are categorized by name, class, interesting groupings, and great localities. These give the class, subclass, group, uses, physical characteristics, and sample photographs of that particular mineral. Anyone interested in geology, minerals, or gemstones will find this site very informative and fun to explore.

1998-01-01

187

Clay Mineral: Radiological Characterization  

NASA Astrophysics Data System (ADS)

Since the early days, clays have been used for therapeutic purposes. Nowadays, most minerals applied as anti-inflammatory, pharmaceutics and cosmetic are the clay minerals that are used as the active ingredient or, as the excipient, in formulations. Although their large use, few information is available in literature on the content of the radionuclide concentrations of uranium and thorium natural series and 40K in these clay minerals. The objective of this work is to determine the concentrations of 238U, 232Th, 226Ra, 228Ra, 210Pb and 40K in commercial samples of clay minerals used for pharmaceutical or cosmetic purposes. Two kinds of clays samples were obtained in pharmacies, named green clay and white clay. Measurement for the determination of 238U and 232Th activity concentration was made by alpha spectrometry and gamma spectrometry was used for 226Ra, 228Ra, 210Pb and 40K determination. Some physical-chemical parameters were also determined as organic carbon and pH. The average activity concentration obtained was 906±340 Bq kg-1 for 40K, 40±9 Bq kg-1 for 226Ra, 75±9 Bq kg-1 for 228Ra, 197±38 Bq kg-1 for 210Pb, 51±26 Bq kg-1 for 238U and 55±24 Bq kg-1 for 232Th, considering both kinds of clay.

Cotomácio, J. G.; Silva, P. S. C.; Mazzilli, B. P.

2008-08-01

188

Introduction to Mineral Equilibria  

NSDL National Science Digital Library

This is short problem set to be used in class. It helps focus discussion, while providing a starting point for discussing mineral reactions and phase diagrams. Students are exposed to ternary composition diagrams and to phase diagrams. They are also introduced to the phase rule, although in quite a superficial way.

Perkins, Dexter

189

Engineering and Mineral Resources  

E-print Network

News ????????????????? ® College of Engineering and Mineral Resources Winter 2008 table of contents. . . . . . . . . . . . . . . . . . . . 7 wvCROSSROADS DepartmentofCivilandEnvironmentalEngineering Civil engineering exchange program and environmental engineering with a focus in transportation will have the opportunity to study abroad as part

Mohaghegh, Shahab

190

Multivitamin/Mineral Supplements  

MedlinePLUS

... least likely to take them. Health promotion and chronic disease prevention For people with certain health problems, specific MVMs might be helpful. For example, a study showed that a particular high-dose formula of several vitamins and minerals slowed vision loss in some people with age- ...

191

Fossils and Minerals  

NSDL National Science Digital Library

This site from the Black Hills Institute features information about different types of fossils, minerals, meteorites, and geology in general. Each topic has a brief description, with links to a more detailed explanation. Various samples and books are abailable for purchase on the site.

Research, Inc. B.

192

Energy and Mineral Resources  

NSDL National Science Digital Library

This site contains 16 questions on the topic of energy and mineral resources, which covers energy sources, resource types, and uses of resources. This is part of the Principles of Earth Science course at the University of South Dakota. Users submit their answers and are provided immediate verification.

Timothy Heaton

193

Secondary condenser Cooling water  

E-print Network

Receiver Secondary condenser LC LC Reboiler TC PC Cooling water PC FCPC Condenser LC XC Throttling valve ¨ mx my l© ª y s § y m «¬ ly my wx l n® ® x np © ¯ Condenser Column Compressor Receiver Super-heater Decanter Secondary condenser Reboiler Throttling valve Expansion valve Cooling water

Skogestad, Sigurd

194

Alphabetical Listing of Mineral Species  

NSDL National Science Digital Library

This directory provides an alphabetical listing of more than 4,000 mineral species. Clicking on each mineral name provides access to information including chemical formula and composition, locality and name origin, physical properties, optical properties, images, and many others.

195

Secondary fuel delivery system  

DOEpatents

A secondary fuel delivery system for delivering a secondary stream of fuel and/or diluent to a secondary combustion zone located in the transition piece of a combustion engine, downstream of the engine primary combustion region is disclosed. The system includes a manifold formed integral to, and surrounding a portion of, the transition piece, a manifold inlet port, and a collection of injection nozzles. A flowsleeve augments fuel/diluent flow velocity and improves the system cooling effectiveness. Passive cooling elements, including effusion cooling holes located within the transition boundary and thermal-stress-dissipating gaps that resist thermal stress accumulation, provide supplemental heat dissipation in key areas. The system delivers a secondary fuel/diluent mixture to a secondary combustion zone located along the length of the transition piece, while reducing the impact of elevated vibration levels found within the transition piece and avoiding the heat dissipation difficulties often associated with traditional vibration reduction methods.

Parker, David M. (Oviedo, FL); Cai, Weidong (Oviedo, FL); Garan, Daniel W. (Orlando, FL); Harris, Arthur J. (Orlando, FL)

2010-02-23

196

Private Mineral Project - Part 1  

NSDL National Science Digital Library

In this semester-long private mineral project, students become experts on one mineral. They write a paper about their mineral and use key information about it to publish a web page. Information should include provenance, physical properties, composition, recent related literature, photos of samples, optical properties, x-ray pattern, crystallography, economic value, atomic structure, other closely related minerals, associated myths, and a complete list of references based on GSA format.

Dexter Perkins

197

Mars' Magnetic Lithosphere: Candidate Minerals  

Microsoft Academic Search

Mars' large southern-hemisphere magnetic anomalies require some combination of (1) a large Martian magnetic field at the time the lithosphere acquired thermoremanent magnetization (TRM), (2) large magnetic mineral concentrations compared to Earth's lithosphere, (3) a mineral or minerals whose grain size and resulting domain structure generate intense TRM, and (4) a high Curie temperature and deep Curie-point isotherm. Induced magnetization

D. J. Dunlop

2003-01-01

198

Mineral Properties -- Learning through Experience  

NSDL National Science Digital Library

Students are each given a mineral and asked to locate all other students in the room with the same mineral (knowing there are a total of 5 different minerals). Once groups form, they need to decide what characteristics are similar for all their samples and ultimately report out to the whole class on their observations.

Wiese, Katryn

199

Mineral industries of the Middle East. Mineral prospective. [16 countries  

SciTech Connect

This report presents a summary of the mineral industries of the 16 countries in the Middle East. Countries in the region differ widely, from those heavily endowed with hydrocarbon resources but with limited nonfuel resources, such as Saudi Arabia, Kuwait, and Qatar, to those heavily mineralized countries with limited petroleum reserves, such as Turkey, and to those with little mineral activity of any kind, such as Lebanon. Base maps and tables show the location and salient features of each country's mineral and petroleum industries. The text highlights the important aspects of mineral supply and trade, mineral policy, industry structure, labor, energy, and the outlook for future developments in the industry. Infrastructure of importance to the mineral industry of each country, including railways, roads, and pipelines, is included on each map.

Not Available

1986-04-01

200

30 CFR 57.22608 - Secondary blasting (I-A, II-A, and V-A mines).  

Code of Federal Regulations, 2012 CFR

...Secondary blasting (I-A, II-A, and V-A mines). 57.22608 Section 57.22608 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH...

2012-07-01

201

30 CFR 57.22608 - Secondary blasting (I-A, II-A, and V-A mines).  

...Secondary blasting (I-A, II-A, and V-A mines). 57.22608 Section 57.22608 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH...

2014-07-01

202

30 CFR 57.22608 - Secondary blasting (I-A, II-A, and V-A mines).  

Code of Federal Regulations, 2013 CFR

...Secondary blasting (I-A, II-A, and V-A mines). 57.22608 Section 57.22608 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH...

2013-07-01

203

43 CFR 3815.1 - Mineral locations.  

Code of Federal Regulations, 2011 CFR

... 2011-10-01 2011-10-01 false Mineral locations. 3815.1 Section 3815.1...LAND MANAGEMENT, DEPARTMENT OF THE INTERIOR MINERALS MANAGEMENT (3000) LANDS AND MINERALS SUBJECT TO LOCATION Mineral Locations...

2011-10-01

204

43 CFR 3816.1 - Mineral locations.  

Code of Federal Regulations, 2011 CFR

... 2011-10-01 2011-10-01 false Mineral locations. 3816.1 Section 3816.1...LAND MANAGEMENT, DEPARTMENT OF THE INTERIOR MINERALS MANAGEMENT (3000) LANDS AND MINERALS SUBJECT TO LOCATION Mineral Locations...

2011-10-01

205

Gillespie Museum of Minerals  

NSDL National Science Digital Library

The Gillespie Museum, located on the campus of Stetson University, houses an extensive rock and mineral collection, and provides visitors and students a place in which curiosity, interest and creativity can be explored. Programs are provided for families, special interest groups, and school groups. The Museum programs focus on using the educational collections to help students learn basic science skills such as observation, classification, communication, investigation and interpretation. The Museum also provides off-site outreach programs by participating in community events such as EarthFest and Earth Day celebrations, local festivals, and scouting programs. Traveling exhibits are developed for loan to other Museums, Chambers of Commerce and Rock and Mineral Clubs. In an effort to present an Earth science museum in a natural setting, a Florida Native Landscape garden has been added to the grounds. The landscape provides an opportunity for individuals to learn alternative ways in which to establish a garden without the use of excess water and pesticides.

2010-11-16

206

Minerals and mine drainage  

SciTech Connect

A review of literature published in 2008 and early 2009 on research related to the production of acid mine drainage and/or in the dissolution of minerals as a result of mining, with special emphasis on the effects of these phenomena on the water quality in the surrounding environment, is presented. This review is divided into six sections: 1) Site Characterization and Assessment, 2) Protection, Prevention, and Restoration, 3) Toxicity Assessment, 4) Environmental Fate and Transport, 5) Biological Characterization, and 6) Treatment Technologies. Because there is much overlap in research areas associated with minerals and mine drainage, many papers presented in this review can be classified into more than one category, and the six sections should not be regarded as being mutually-exclusive, nor should they be thought of as being all-inclusive.

Liang, H.C.; Thomson, B.M. [Tetra Technical Inc, Denver, CO (United States)

2009-09-15

207

Calcite: The multiuse mineral  

Microsoft Academic Search

If people were told that a newly discovered mineral polarizes light, provides a raw material for sculptors, diminishes the danger of hip breakage, makes long-lasting foundations for buildings, reduces pollution at power plants, serves as a soil conditioner and water purifier, and saves life on earth from suffocation, they might be inclined to say either {open_quotes}Ain`t science wonderful!{close_quotes} or {open_quotes}Come

Paschall

1994-01-01

208

Clay Mineral: Radiological Characterization  

SciTech Connect

Since the early days, clays have been used for therapeutic purposes. Nowadays, most minerals applied as anti-inflammatory, pharmaceutics and cosmetic are the clay minerals that are used as the active ingredient or, as the excipient, in formulations. Although their large use, few information is available in literature on the content of the radionuclide concentrations of uranium and thorium natural series and {sup 40}K in these clay minerals.The objective of this work is to determine the concentrations of {sup 238}U, {sup 232}Th, {sup 226}Ra, {sup 228}Ra, {sup 210}Pb and {sup 40}K in commercial samples of clay minerals used for pharmaceutical or cosmetic purposes. Two kinds of clays samples were obtained in pharmacies, named green clay and white clay.Measurement for the determination of {sup 238}U and {sup 232}Th activity concentration was made by alpha spectrometry and gamma spectrometry was used for {sup 226}Ra, {sup 228}Ra, {sup 210}Pb and {sup 40}K determination. Some physical-chemical parameters were also determined as organic carbon and pH. The average activity concentration obtained was 906{+-}340 Bq kg{sup -1} for {sup 40}K, 40{+-}9 Bq kg{sup -1} for {sup 226}Ra, 75{+-}9 Bq kg{sup -1} for {sup 228}Ra, 197{+-}38 Bq kg{sup -1} for {sup 210}Pb, 51{+-}26 Bq kg{sup -1} for {sup 238}U and 55{+-}24 Bq kg{sup -1} for {sup 232}Th, considering both kinds of clay.

Cotomacio, J. G. [Centro Universitario Nove de Julho, R: Diamantina, 602-Vila Maria, CEP: 02117-0101, Sao Paulo (Brazil); Silva, P. S. C. [Centro de Metrologia das Radiacoes-Instituto de Pesquisas Energeticas e Nucleares, Av. Prof. Lineu Prestes 2242-Cidade Universitaria-CEP 05508 000 Sao Paulo-Brazil (Brazil); Mazzilli, B. P

2008-08-07

209

Exploring Bone Mineral Density  

NSDL National Science Digital Library

In this activity, students will explore two given websites to gather information on Bone Mineral Density and how it is measured. They will also learn about X-rays in general, how they work and their different uses, along with other imaging modalities. They will answer guiding questions as they explore the websites and take a short quiz after to test the knowledge they gained while reading the articles.

Vu Bioengineering Ret Program

210

The Clay Minerals Society  

NSDL National Science Digital Library

"The Clay Minerals Society (CMS) is an international community of scientists who promote research in and disseminate information on clay science and technology." The website provides downloads of materials dealing with various aspects of mineralogy, geochemistry, and petrology. Researchers can find out about annual meetings, awards and grants, and publications. Students and educators can find information on teaching materials, clay science workshops, and games. The website offers physical and chemical data for Source and Special Clays.

211

Green Clay Minerals  

NASA Astrophysics Data System (ADS)

Color is a problem for scientific study. One aspect is the vocabulary one used to describe color. Mint green, bottle green, and Kelly green are nice names but not of great utility in that people's physical perception of color is not always the same. In some industries, such as colored fabric manufacture, current use is to send a set of standard colors which are matched by the producer. This is similar to the use of the Munsell color charts in geology. None of these processes makes use of physical optical spectral studies. The reason is that they are difficult to obtain and interpret. For a geologist, color is very important but we rarely have the possibility to standardize the method of our color perception. One reason is that color is both a reflective and transmission phenomenon. The thickness of the sample is critical to any transmission characteristics. Hence, a field color determination is different from one made by using a petrographic microscope. Green glauconite in a hand specimen is not the same color in 30 ?m thick thin section seen with a microscope using transmitted light.A second problem is that color in a spectral identification is the result of several absorption emissions,with overlapping signal, forming a complicated spectrum. Interpretation depends very greatly on the spectrum of the light source and the conditions of transmission-reflection of the sample. As a result, for this text, we will not attempt to analyze the physical aspect of green in green clays. In the discussion which follows, reference is made concerning color, to thin section microscopic perception.Very briefly, green clay minerals are green, because they contain iron. This is perhaps not a great revelation to mineralogists, but it is the key to understanding the origin and stability of green clay minerals. In fact, iron can color minerals either red or green or in various shades of orange and brown. The color most likely depends upon the relative abundance of the iron ion valence in the silicate (clay mineral in our case) structure, the specific bonding of these ions, and other factors. In fact, the reasons for coloration are not known completely, but it is certain that a combination of Fe2+ and Fe3+ ions is necessary to give a nice green color to clays. In the green clay minerals discussed here, the colors vary greatly as seen under the optical microscope (not always the same as the one seen in hand specimen). Yellow to blue-green hues can be found. However, for the moment, no clear relation between iron content, iron valence ratio, or other factors such as minor transition element concentrations can be found to explain the greenness of green clay minerals. The fact that a clay is green just indicates a combination of the two oxidation states of iron. The color, however, indicates the key to the formation in nature of green clay minerals.Green clay minerals are in general the product of "mixed valence" conditions of formation, most often in a situation where some iron is reduced from Fe3+ and enters into a silicate mineral structure. In general, iron would rather be an oxide when it is in the trivalent state. The moment iron is reduced to a divalent state under surface or near-surface conditions, it looks for a silicate, sulfide, or carbonate to hide in. The reverse is also true, of course. When a silicate is oxidized, Fe2+ becoming Fe3+, the iron begins to group together in oxide clumps and eventually exits the silicate structure. This is seen in thin section in altered rocks (weathering or hydrothermal action). The production of trivalent, oxidized iron usually results in a brownish or orange mineral.If the geology of the formation of green silicate minerals is relatively well defined, especially at near surface or surface conditions, the question remains how much of the iron is in a reduced oxidation state and how? In the case of reduction of iron in surface environments: if most of the iron goes to Fe2+, one mineral is formed; if only part of it is reduced, another is formed. This is the fundamental geochemical aspect of

Velde, B.

2003-12-01

212

Salton sea minerals  

NASA Astrophysics Data System (ADS)

The long-held notion that precious metals, minerals, and other useful substances can be extracted from natural waters is starting to become realized at several locations of geothermal brines. In a recent study by A. Maimoni of the Lawrence Livermore National Laboratory it was determined that there is a high potential for minerals recovery from the hot brines of a 1000-MWe geothermal power station at the Salton Sea geothermal field in southern California. The study estimated that the revenue from the minerals could substantially exceed that from the power station (Geothermics, 11, 239-258, 1982).According to the study, ‘A 1000-MWe power plant could recover 14-31% of the U.S. demand for manganese.’ In the example of lithium production, such a geothermal plant could produce 5-10 times the annual world output of lithium. Large quantities of lead and zinc could be extracted, as well as significant amounts of gold, platinum, and silver. The chemical composition of the brines is incredibly complex, however, for reasons not currently understood.

Bell, Peter M.

213

Electron microprobe mineral analysis guide  

NASA Technical Reports Server (NTRS)

Electron microprobe mineral analysis guide is a compilation of X-ray tables and spectra recorded from various mineral matrices. Spectra were obtained using electron microprobe, equipped with LiF geared, curved crystal X-ray spectrometers, utilizing typical analytical operating conditions: 15 Kv acceleration potential, 0.02 microampere sample current as measured on a clinopyroxene standard (CP19). Tables and spectra are presented for the majority of elements, fluorine through uranium, occurring in mineral samples from lunar, meteoritic and terrestrial sources. Tables for each element contain relevant analytical information, i.e., analyzing crystal, X-ray peak, background and relative intensity information, X-ray interferences and a section containing notes on the measurement. Originally intended to cover silicates and oxide minerals the tables and spectra have been expanded to cover other mineral phases. Electron microprobe mineral analysis guide is intended as a spectral base to which additional spectra can be added as the analyst encounters new mineral matrices.

Brown, R. W.

1980-01-01

214

The clinical application of bone mineral analysis  

Microsoft Academic Search

Photon absorptiometry provides an accurate measurement of bone mineral content. In acromegaly, the bone mineral content is normal, whereas the bone mineral content is reduced by acidosis. Decreased bone mineral content occurs in alcoholics due to osteomalacia and also in anticonvulsant therapy for the same reason. In hyperparathyroidism, there is decreased bone mineral content. Corticosteroids reduce bone mineral content especially

Harry J. Griffiths; Robert E. Zimmerman

1978-01-01

215

Secondary containment system  

SciTech Connect

This patent describes a pumping system for fluid products, such as gasoline, diesel fuel and chemicals, and including a pump for pumping such products from a storage tank through a primary pipeline to a product dispenser. The improvement consists of a secondary containment system for the pipeline between the storage tank and the product dispenser and including a secondary pipe system surrounding the primary pipeline. The secondary pipe system includes telescoping pipe sections of different diameters, which are installed around the primary pipeline and which are, prior to final installation, movable between intermediate and final positions, for enabling completion, testing and inspection of the primary pipeline prior to final completion of the secondary containment system.

Webb, M.C.

1989-02-21

216

Secondary Procedures in Replantation  

PubMed Central

The success of replantation surgery is not judged by survival of the replanted part, but by the functional outcome attained. Hence, primary repair of all injured structures is the preferred aim. At times, constraints induced by the ischemia time and nature of injury preclude primary repair. In such situations, secondary procedures are inevitable. Secondary procedures are also frequently required to improve the function and appearance of the replanted extremity. The incidence of secondary procedures will vary with the level of replantation and the type of patient population. Secondary procedures are difficult because they carry risk of injury to the vital neurovascular structures that now lay at nonanatomical locations. Nevertheless, when indicated and performed with caution they could significantly raise the functional status of the individuals. PMID:24872769

Sabapathy, S. Raja; Bhardwaj, Praveen

2013-01-01

217

Personalizing Secondary Curriculum  

ERIC Educational Resources Information Center

To facilitate "personalizing" and individualizing secondary school curriculum, the author presents eight conceptual aspects of individualization and discusses the relationship of these concepts to program design and implementation of an individual learning program. (HMD)

Bailey, William J.

1974-01-01

218

[Secondary myelodysplastic syndrome].  

PubMed

Secondary or therapy related myelodysplastic syndrome may develop following treatment with alkylating agents and radiotherapy. The condition may also follow high dose therapy for malignant lymphomas. We describe two patients who developed secondary myelodysplasia. The first is a 76-year old female with a low grade lymphoma who developed pancytopenia with monosomy 7. Secondary myelodysplasia was diagnosed 24 months after treatment with chlorambucil (total dose of 900 mg) and 12 months after treatment with trophosphamide (total dose of 24 g). The second patient was a 48-year old male who underwent autologous bone marrow transplantation for a relapsed low grade lymphoma. Following autografting he had persistent anemia and trombocytopenia. Secondary myelodysplastic syndrome with complex karyotype was diagnosed 54 months after high dose therapy. He died nine months later of bone marrow failure. PMID:9441464

Shammas, F V; Heikkilä, R

1997-11-30

219

Secondary chondrosarcoma: radiopathological correlation.  

PubMed

Chondrosarcomas are malignant bone tumors originating in cartilage. Chondrosarcoma is the third most common malignant bone tumor after multiple myeloma and osteosarcoma. About 75% of chondrosarcomas are primary lesions. The remaining 25% belong to special categories such as histologic variants and secondary forms. A secondary chondrosarcoma is one that appears in a pre-existing benign chondral lesion; the different types of secondary chondrosarcomas include solitary osteochondroma, multiple osteochondromatosis, enchondroma, the different types of enchondromatosis, and primary synovial chondromatosis. The incidence of this malignant transformation varies widely in function of the type of lesion. In this article, we discuss and illustrate the different types of secondary chondrosarcomas, placing special emphasis on the imaging findings that should alert to these lesions and give radiologists a key role in the diagnosis, management, and follow-up of these patients. PMID:25002353

Lozano Martínez, G A; Llauger Rosselló, J

2014-07-01

220

Secondary Endolymphatic Hydrops (SEH)  

MedlinePLUS

... as Ménière’s disease) occurs for no known reason. Secondary endolymphatic hydrops appears to occur in response to an event or underlying condition. For example, it can follow head trauma or ear surgery, and it can occur with ...

221

Secondary extinctions of biodiversity.  

PubMed

Extinctions beget further extinctions when species lose obligate mutualists, predators, prey, or hosts. Here, we develop a conceptual model of species and community attributes affecting secondary extinction likelihood, incorporating mechanisms that buffer organisms against partner loss. Specialized interactors, including 'cryptic specialists' with diverse but nonredundant partner assemblages, incur elevated risk. Risk is also higher for species that cannot either evolve new traits following partner loss or obtain novel partners in communities reorganizing under changing environmental conditions. Partner loss occurs alongside other anthropogenic impacts; multiple stressors can circumvent ecological buffers, enhancing secondary extinction risk. Stressors can also offset each other, reducing secondary extinction risk, a hitherto unappreciated phenomenon. This synthesis suggests improved conservation planning tactics and critical directions for research on secondary extinctions. PMID:25445878

Brodie, Jedediah F; Aslan, Clare E; Rogers, Haldre S; Redford, Kent H; Maron, John L; Bronstein, Judith L; Groves, Craig R

2014-12-01

222

Heterogeneous mineral assemblages in martian meteorite Tissint as a result of a recent small impact event on Mars  

NASA Astrophysics Data System (ADS)

The microtexture and mineralogy of shock melts in the Tissint martian meteorite were investigated using scanning electron microscopy, Raman spectroscopy, transmission electron microscopy and synchrotron micro X-ray diffraction to understand shock conditions and duration. Distinct mineral assemblages occur within and adjacent to the shock melts as a function of the thickness and hence cooling history. The matrix of thin veins and pockets of shock melt consists of clinopyroxene + ringwoodite ± stishovite embedded in glass with minor Fe-sulfide. The margins of host rock olivine in contact with the melt, as well as entrained olivine fragments, are now amorphosed silicate perovskite + magnesiowüstite or clinopyroxene + magnesiowüstite. The pressure stabilities of these mineral assemblages are ?15 GPa and >19 GPa, respectively. The ?200-?m-wide margin of a thicker, mm-size (up to 1.4 mm) shock melt vein contains clinopyroxene + olivine, with central regions comprising glass + vesicles + Fe-sulfide spheres. Fragments of host rock within the melt are polycrystalline olivine (after olivine) and tissintite + glass (after plagioclase). From these mineral assemblages the crystallization pressure at the vein edge was as high as 14 GPa. The interior crystallized at ambient pressure. The shock melts in Tissint quench-crystallized during and after release from the peak shock pressure; crystallization pressures and those determined from olivine dissociation therefore represent the minimum shock loading. Shock deformation in host rock minerals and complete transformation of plagioclase to maskelynite suggest the peak shock pressure experienced by Tissint ? 29-30 GPa. These pressure estimates support our assessment that the peak shock pressure in Tissint was significantly higher than the minimum 19 GPa required to transform olivine to silicate perovskite plus magnesiowüstite. Small volumes of shock melt (<100 ?m) quench rapidly (0.01 s), whereas thermal equilibration will occur within 1.2 s in larger volumes of melt (1 mm2). The apparent variation in shock pressure recorded by variable mineral assemblages within and around shock melts in Tissint is consistent with a shock pulse on the order of 10-20 ms combined with a longer duration of post-shock cooling and complex thermal history. This implies that the impact on Mars that shocked and ejected Tissint at ?1 Ma was not exceptionally large.

Walton, E. L.; Sharp, T. G.; Hu, J.; Filiberto, J.

2014-09-01

223

Bacteriophage secondary infection.  

PubMed

Phages are credited with having been first described in what we now, officially, are commemorating as the 100(th) anniversary of their discovery. Those one-hundred years of phage history have not been lacking in excitement, controversy, and occasional convolution. One such complication is the concept of secondary infection, which can take on multiple forms with myriad consequences. The terms secondary infection and secondary adsorption, for example, can be used almost synonymously to describe virion interaction with already phage-infected bacteria, and which can result in what are described as superinfection exclusion or superinfection immunity. The phrase secondary infection also may be used equivalently to superinfection or coinfection, with each of these terms borrowed from medical microbiology, and can result in genetic exchange between phages, phage-on-phage parasitism, and various partial reductions in phage productivity that have been termed mutual exclusion, partial exclusion, or the depressor effect. Alternatively, and drawing from epidemiology, secondary infection has been used to describe phage population growth as that can occur during active phage therapy as well as upon phage contamination of industrial ferments. Here primary infections represent initial bacterial population exposure to phages while consequent phage replication can lead to additional, that is, secondary infections of what otherwise are not yet phage-infected bacteria. Here I explore the varying meanings and resultant ambiguity that has been associated with the term secondary infection. I suggest in particular that secondary infection, as distinctly different phenomena, can in multiple ways influence the success of phage-mediated biocontrol of bacteria, also known as, phage therapy. PMID:25595214

Abedon, Stephen T

2015-02-01

224

Mechanisms of primary mineral weathering inferred from B isotopes  

NASA Astrophysics Data System (ADS)

Silicate weathered minerals result from a combination of dissolution/precipitation or transformation reactions. Despite their chemical and isotopic compositions as well as their mineralogy record the physico-chemical conditions of their formation and history, the determination of the current state of weathering in soils still remains very challenging. The main difficulties come from a difficult access to the mineral sites actually active during primary mineral transformation and from non-stoichiometric release of site-forming cations. To better characterize how minerals record the conditions of their formation, we coupled analyses of mineralogy with major elements and boron isotopes in a series of primary minerals (biotite, muscovite, K-feldspar and plagioclase) associated in varying amount with their replacement phases (vermiculite, kaolinite, illite…). The minerals are sampled along an acid Alocrisoil profile developed on granitic bedrock from the Breuil-Chenue forest (France). Previous studies have demonstrated that boron occupies different minerals sites (tetrahedron in substitution of Si, or interfoliar sites possibly in direct contact with the surrounding fluid, Williams et al. 2001, Muttik et al. 2011, Voinot et al., in prep.). Voinot et al. (in prep.) have also demonstrated that boron isotopes are very sensitive to silicate transformation or dissolution reactions. In deeper soil layers (100 to 130 cm), kaolinite is found in biotite mineral habitus. Examination of the boron isotopes distribution in those weathered agglomerates points to a boron depletion and a rapid isotopic equilibration with the surrounding soil solution as kaolinite fraction increases. The same - but magnified - trend is observed during shallow weathering mechanisms (20 to 30 cm) of fine particles of biotite (< 200 µm). By contrast, coarse biotite minerals (> 200 µm) evolve to a vermiculite-like product that tends to be enriched in boron (up to three times the initial biotite concentration) but share a common isotopic composition with kaolinite revealing an equilibrium with the solution. Plagioclases dissolve very early in the deepest horizon with a high degree of in-situ kaolinite reprecipitation in their mineral habitus. Here again, the isotopic composition reflect exchange with the soil solution. Muscovite shows no particular weathering mechanism other than dissolution, but isotope shift toward the soil solution value tends to indicate that the reacting boron is mainly located in easy accessible mineral interlayer sites. K-feldspar samples remained unchanged either mineralogically or isotopically. These results suggest an apparent duality between phyllosilicates which are mainly involved in transformation reactions with rapid isotopic equilibration with the surrounding soil solution, whilst tectosilicates show mainly dissolution reactions without evidence of isotopic exchange with the fluid. Depending on their nature, the secondary phases that replace the weathered primary minerals will also play a major role in the boron cycle in soils.

Voinot, A.; Turpault, M.-P.; Chabaux, F.; Lemarchand, D.

2012-04-01

225

Secondary psychoses: an update  

PubMed Central

Psychotic disorders due to a known medical illness or substance use are collectively termed secondary psychoses. In this paper, we first review the historic evolution of the concept of secondary versus primary psychosis and how this distinction supplanted the earlier misleading classification of psychoses into organic and functional. We then outline the clinical features and approach to the diagnosis of secondary psychotic disorders. Features such as atypical presentation, temporal relation to detectable medical cause, evidence of direct physiological causal relationship to the etiological agent, and the absence of evidence of a primary psychotic illness that may better explain the presentation suggest consideration of a secondary psychosis. Finally, we discuss how careful studies of secondary psychotic disorders can help elucidate the pathophysiology of primary, or idiopathic, psychotic disorders such as schizophrenia. We illustrate this issue through a discussion of three secondary psychotic disorders — psychoses associated with temporal lobe epilepsy, velocardiofacial syndrome, and N-methyl D-aspartate (NMDA) receptor encephalitis — that can, respectively, provide neuroanatomical, genetic, and neurochemical models of schizophrenia pathogenesis. PMID:23471787

Keshavan, Matcheri S; Kaneko, Yoshio

2013-01-01

226

Linking Home Plate and Algonquin Class Rocks through Microtextural Analysis: Evidence for Hydrovolcanism in the Inner Basin of Columbia Hills, Gusev Crater  

NASA Technical Reports Server (NTRS)

Examining the his-tory of a rock as the summed history of its constituent grains is a proven and powerful strategy that has been used on Earth to maximize the information that can be gleaned from limited samples. Grain size, sorting, roundness, and texture can be observed at the handlens scale, and may reveal clues to transport regime (e.g. fluvial, glacial, eolian) and transport distance. Diagenetic minerals may be of a form and textural context to allow identification, and to point to dominant diagenetic processes (e.g. evaporitic concentration, intermittent dissolution, early vs. late diagenetic emplacement). Handlens scale features of volcaniclastic particles may be diagnostic of primary vs recycled (by surface processes) grains and may provide information about eruptive patterns and processes. When the study site is truly remote, such as Mars, and when there are severe limitations on sample return or sample analysis with other methods, examination at the hand lens scale becomes critical both for extracting a maximum of information, and for best utilizing finite analytical capabilities.

Mittlefehldt, David W.; Yingst, R. Aileen; Schmidt, Mariek E.; Herkenhoff, Ken E.

2007-01-01

227

Geophysical signatures of disseminated iron minerals: A proxy for understanding subsurface biophysicochemical processes  

NASA Astrophysics Data System (ADS)

studies have linked biogeophysical signatures to the presence of iron minerals resulting from distinct biophysicochemical processes. Utilizing geophysical methods as a proxy of such biophysicochemical processes requires an understanding of the geophysical signature of the different iron minerals. Laboratory experiments were conducted to investigate the complex conductivity and magnetic susceptibility signatures of five iron minerals disseminated in saturated porous media under variable iron mineral content and grain size. Both pyrite and magnetite show high quadrature and inphase conductivities compared to hematite, goethite, and siderite, whereas magnetite was the highly magnetic mineral dominating the magnetic susceptibility measurements. The quadrature conductivity spectra of both pyrite and magnetite exhibit a well-defined characteristic relaxation peak below 10 kHz, not observed with the other iron minerals. The quadrature conductivity and magnetic susceptibility of individual and a mixture of iron minerals are dominated and linearly proportional to the mass fraction of the highly conductive (pyrite and magnetite) and magnetic (magnetite) iron minerals, respectively. The quadrature conductivity magnitude increased with decreasing grain size diameter of magnetite and pyrite with a progressive shift of the characteristic relaxation peak toward higher frequencies. The quadrature conductivity response of a mixture of different grain sizes of iron minerals is shown to be additive, whereas magnetic susceptibility measurements were insensitive to the variation in grain size diameters (1-0.075 mm). The integration of complex conductivity and magnetic susceptibility measurements can therefore provide a complimentary tool for the successful investigation of in situ biophysicochemical processes resulting in biotransformation or secondary iron mineral precipitation.

Abdel Aal, Gamal Z.; Atekwana, Estella A.; Revil, A.

2014-09-01

228

Bone and Mineral Metabolism in Patients with Primary Aldosteronism  

PubMed Central

Primary aldosteronism represents major cause of secondary hypertension, strongly associated with high cardiovascular morbidity and mortality. Aldosterone excess may influence mineral homeostasis, through higher urinary calcium excretion inducing secondary increase of parathyroid hormone. Recently, in a cohort of PA patients a significant increase of primary hyperparathyroidism was found, suggesting a bidirectional functional link between the adrenal and parathyroid glands. The aim of this study was to evaluate the impact of aldosterone excess on mineral metabolism and bone mass density. In 73 PA patients we evaluated anthropometric and biochemical parameters, renin-angiotensin-aldosterone system, calcium-phosphorus metabolism, and bone mineral density; control groups were 73 essential hypertension (EH) subjects and 40 healthy subjects. Compared to HS and EH, PA subjects had significantly lower serum calcium levels and higher urinary calcium excretion. Moreover, PA patients showed higher plasma PTH, lower serum 25(OH)-vitamin D levels, higher prevalence of vitamin D deficiency (65% versus 25% and 25%; P < 0.001), and higher prevalence of osteopenia/osteoporosis (38.5 and 10.5%) than EH (28% and 4%) and NS (25% and 5%), respectively. This study supports the hypothesis that bone loss and fracture risk in PA patients are potentially the result of aldosterone mediated hypercalciuria and the consecutive secondary hyperparathyroidism. PMID:24864141

Petramala, Luigi; Zinnamosca, Laura; Settevendemmie, Amina; Marinelli, Cristiano; Nardi, Matteo; Concistrè, Antonio; Corpaci, Francesco; Tonnarini, Gianfranco; De Toma, Giorgio; Letizia, Claudio

2014-01-01

229

Rocks and Minerals  

NSDL National Science Digital Library

This web page offers a simple illustrated guide to the three rock types- igneous, sedimentary, and metamorphic; and the most common rock-forming mineral groups: quartz, plagioclase feldspars, potassium feldspars, micas, amphiboles, olivine, and calcite. The rock types include extrusive and intrusive igneous rocks, clastic, biologic, and chemical sedimentary rocks, and both foliated and non-foliated metamorphic rocks. A section is included on naming igneous rocks. The igneous rocks tuff and basalt are also discussed, as is sediment. Users are directed to related resources and may print out a simplified rock classification chart.

230

Carbonate-mineral/water interactions in sulfide-rich mine tailings  

NASA Astrophysics Data System (ADS)

The chemical composition and mineralogy of coatings on carbonate minerals from mine tailings have been studied using aqueous geochemical methods, Time-of-Flight Laser-Ionization Mass Spectrometry (TOF-LIMS) and Transmission Electron Microscopy (TEM). The goal is to study major and trace element partitioning between the aqueous and solid phase, and to infer mechanisms that control the concentrations of elements in the pore water of sulfide-rich mine tailings. Pore-water samples and carbonate-mineral grains were collected from four geochemically distinct zones within the tailings. Oxidation of sulfide minerals near the surface results in a large range in pore-water pH (3.85 to 6.98) and aqueous concentrations of metals and sulfate. With increasing depth in the tailings, mineral-water interactions lead to increasing pH, and decreasing concentrations of metals and sulfate. Calculated mineral saturation indices, trends in the abundance of Ca, Fe, Mg and Mn in TOF-LIMS profiles through the secondary coatings, and electron diffraction patterns obtained from the coatings, suggest that precipitation/dissolution of jarosite-group minerals, gypsum, goethite, akaganéite, amorphous Fe oxyhydroxides and siderite control the aqueous Ca, Fe, Na, K and SO 4 concentrations. The occurrence of secondary coatings on primary minerals is widespread, and reactions with the secondary minerals, rather than the primary mineral substrate, probably represent the principal controls on trace-element distributions in the pore water. The data indicate that adsorption, surface-complexation and co-precipitation reactions are important controls on the concentrations of trace elements in the pore water. The occurrence of siderite coatings on the surface of ankerite grains suggests that Fe-bearing dolomite-structure carbonate minerals dissolve incongruently. This corroborates inferences made by previous workers that solubility differences between calcite and siderite lead to calcite dissolution and siderite precipitation during acid neutralization. The accumulation of secondary coatings will diminish the rate of mineral-dissolution reactions involving the primary minerals. Consequently, the use of kinetic rate constants obtained from the literature for simulating the dissolution of primary mineral phases such as the carbonates and alumino-silicates will likely overestimate the actual rates.

Al, Tom A.; Martin, Chris J.; Blowes, David W.

2000-12-01

231

Spectroscopic characterization of manganese minerals  

NASA Astrophysics Data System (ADS)

Manganese minerals ardenite, alleghanyite and leucopoenicite originated from Madhya Pradesh, India, Nagano prefecture Japan, Sussex Country and Parker Shaft Franklin, Sussex Country, New Jersey respectively are used in the present work. In these minerals manganese is the major constituent and iron if present is in traces only. An EPR study of on all of the above samples confirms the presence of Mn(II) with g around 2.0. Optical absorption spectrum of the mineral alleghanyite indicates that Mn(II) is present in two different octahedral sites and in leucophoenicite Mn(II) is also in octahedral geometry. Ardenite mineral gives only a few Mn(II) bands. NIR results of the minerals ardenite, leucophoenicite and alleghanyite are due to hydroxyl and silicate anions which confirming the formulae of the minerals.

Lakshmi Reddy, S.; Padma Suvarna, K.; Udayabhaska Reddy, G.; Endo, Tamio; Frost, R. L.

2014-01-01

232

Mars' Magnetic Lithosphere: Candidate Minerals  

Microsoft Academic Search

Mars' southern-hemisphere magnetic anomalies require a large Martian magnetic field at the time the lithosphere acquired thermoremanent magnetization (TRM), large magnetic mineral concentrations compared to Earth's lithosphere, a mineral or minerals whose grain size and resulting domain structure generate intense TRM, and\\/or a high Curie temperature and deep Curie-point isotherm. Based on Martian meteorites and spectroscopy of the Martian surface,

D. J. Dunlop; J. Arkani-Hamed

2004-01-01

233

Microelectrophoresis of selected mineral particles  

NASA Technical Reports Server (NTRS)

Particle mobilities of ilmenite, labradorite plagioclase, enstatite pyroxene, and olivine were measured with a Rank microelectrophoresis system to evaluate indicated mineral separability. Sodium bicarbonate buffer suspension media with and without additives (0.0001 M DTAB and 5 percent v/v ethylene glycol) were used to determine differential adsorption by mineral particles and modification of relative mobilities. Good separability between some minerals was indicated; additives did not enhance separability.

Herren, B. J.; Tipps, R. W.; Alexander, K. D.

1982-01-01

234

Mineral Time Capsules on Mars?  

NASA Technical Reports Server (NTRS)

Like dinosaur-age insects trapped in amber, biomolecules sequestered in million-year-old sulfate minerals could provide a glimpse into the past, say researchers who've recently analyzed such minerals from N orth America. The same minerals have recently been discovered on Mars , so they may be a good place to look for traces of past life on the red planet, the researchers say.

Schirber, Michael

2006-01-01

235

MICROBIOLOGY: How Bacteria Respire Minerals  

NSDL National Science Digital Library

Access to the article is free, however registration and sign-in are required: Some bacteria respire minerals; that is, they harvest energy from minerals through using them as electron acceptors. Many details of this respiration process have remained obscure. In her Perspective, Newman highlights the study by Lower et al., who have used a customized atomic force microscope to observe bacteria during mineral respiration.

Dianne K. Newman (California Institute of Technology;Division of Geological and Planetary Sciences)

2001-05-18

236

Heintzmann continuous longwall miner  

SciTech Connect

Geologic Considerations for the Continuous Longwall Miner The mining of the thin seams allows: (1) an optimum return of the capital invested, (2) delay mining of seams at greater depth, or opening other mines, (3) a maximization of resources, (4) a prolongation of mine-lifespan. Meanwhile, deposits having seam thicknesses of about 3 feet have been proven to yield economical gains. This situation requires mining machines that possess the ability to effectively mine thin seams containing tough but plowable coal. To reach this goal, the plow systems were equipped to achieve more horsepower. The use of plows has declined due to: (1) higher weight, (2) higher purchase costs, (3) and higher repair costs. In the cutting conveying method, two objectives have to be addressed: (1) The load on the cutting machines has to be reduced by a more effective cutting-principle and a working method adjusted to the coal. (2) Cutting and conveying have to be simultaneous. Only with the CLM Miner, can mining rates be advanced in thin seams.

Guse, K. [Heintzmann, Cedar Bluff, VA (United States); Polsh, J.

1996-12-31

237

Vienna RNA secondary structure server  

Microsoft Academic Search

The Vienna RNA secondary structure server provides a web interface to the most frequently used functions of the Vienna RNA software package for the analysis of RNA secondary structures. It currently offers prediction of secondary structure from a single sequence, prediction of the consensus secondary structure for a set of aligned sequences, and the design of sequences that will fold

Ivo L. Hofacker

2003-01-01

238

Sustainable mineral resources management: from regional mineral resources exploration to spatial contamination risk assessment of mining  

NASA Astrophysics Data System (ADS)

Wide-spread environmental contamination associated with historic mining in Europe has triggered social responses to improve related environmental legislation, the environmental assessment and management methods for the mining industry. Mining has some unique features such as natural background contamination associated with mineral deposits, industrial activities and contamination in the three-dimensional subsurface space, problem of long-term remediation after mine closure, problem of secondary contaminated areas around mine sites, land use conflicts and abandoned mines. These problems require special tools to address the complexity of the environmental problems of mining-related contamination. The objective of this paper is to show how regional mineral resources mapping has developed into the spatial contamination risk assessment of mining and how geological knowledge can be transferred to environmental assessment of mines. The paper provides a state-of-the-art review of the spatial mine inventory, hazard, impact and risk assessment and ranking methods developed by national and international efforts in Europe. It is concluded that geological knowledge on mineral resources exploration is essential and should be used for the environmental contamination assessment of mines. Also, sufficient methodological experience, knowledge and documented results are available, but harmonisation of these methods is still required for the efficient spatial environmental assessment of mine contamination.

Jordan, Gyozo

2009-07-01

239

Influence of abiotic stress signals on secondary metabolites in plants.  

PubMed

Plant secondary metabolites are unique sources for pharmaceuticals, food additives, flavors, and industrially important biochemicals. Accumulation of such metabolites often occurs in plants subjected to stresses including various elicitors or signal molecules. Secondary metabolites play a major role in the adaptation of plants to the environment and in overcoming stress conditions. Environmental factors viz. temperature, humidity, light intensity, the supply of water, minerals, and CO2 influence the growth of a plant and secondary metabolite production. Drought, high salinity, and freezing temperatures are environmental conditions that cause adverse effects on the growth of plants and the productivity of crops. Plant cell culture technologies have been effective tools for both studying and producing plant secondary metabolites under in vitro conditions and for plant improvement. This brief review summarizes the influence of different abiotic factors include salt, drought, light, heavy metals, frost etc. on secondary metabolites in plants. The focus of the present review is the influence of abiotic factors on secondary metabolite production and some of important plant pharmaceuticals. Also, we describe the results of in vitro cultures and production of some important secondary metabolites obtained in our laboratory. PMID:22041989

Ramakrishna, Akula; Ravishankar, Gokare Aswathanarayana

2011-11-01

240

Assessment of the geoavailability of trace elements from selected zinc minerals  

USGS Publications Warehouse

This assessment focused on five zinc-bearing minerals. The minerals were subjected to a number of analyses including quantitative X-ray diffraction, optical microscopy, leaching tests, and bioaccessibility and toxicity studies. Like a previous comprehensive assessment of five copper-bearing minerals, the purpose of this assessment was to obtain structural and chemical information and to characterize the reactivity of each mineral to various simulated environmental and biological conditions. As in the copper minerals study, analyses were conducted consistent with widely accepted methods. Unless otherwise noted, analytical methods used for this study were identical to those described in the investigation of copper-bearing minerals. Two sphalerite specimens were included in the zinc-minerals set. One sphalerite was recovered from a mine in Balmat, New York; the second came from a mine in Creede, Colorado. The location and conditions of origin are significant because, as analyses confirmed, the two sphalerite specimens are quite different. For example, data acquired from a simulated gastric fluid (SGF) study indicate that the hydrothermally formed Creede sphalerite contains orders of magnitude higher arsenic, cadmium, manganese, and lead than the much older metamorphic Balmat sphalerite. The SGF and other experimental results contained in this report suggest that crystallizing conditions such as temperature, pressure, fluidization, or alteration processes significantly affect mineral properties—properties that, in turn, influence reactivity, solubility, and toxicity. The three remaining minerals analyzed for this report—smithsonite, hemimorphite, and hydrozincite—are all secondary minerals or alteration products of zinc-ore deposits. In addition, all share physical characteristics such as tenacity, density, streak, and cleavage. Similarities end there. The chemical composition, unit-cell parameters, acid-neutralizing potential, and other observable and quantifiable properties indicate very different minerals. Only one of each of these minerals was studied. Had this assessment included multiples of these minerals, geochemical and mineralogical distinctions would have emerged, similar to the results for the two sphalerite specimens.

Driscoll, Rhonda L.; Hageman, Phillip L.; Benzel, William M.; Diehl, Sharon F.; Morman, Suzette; Choate, LaDonna M.; Lowers, Heather

2014-01-01

241

Electrokinetic properties of soil minerals and soils modified with polyelectrolytes  

NASA Astrophysics Data System (ADS)

The formation features of nanoadsorption polyelectrolyte (PE) layers with the formation of a mineral-organic matrix on the surface of clay minerals and soils (kaolinite, montmorillonite, quartz sand, gray forest soil, and chernozemic soil) have been elucidated by direct adsorption measurements. It has been found that the experimental values for the limit adsorption of polyacrylamide (PAM) and polyacrylic acid (PAA) on all the minerals are significantly higher than the calculated values for the formation of a monolayer. This indicates adsorption on the surface of not only separate macromolecules but also secondary PE structures as packets or fibrils determining the cluster-matrix structure of the modified surface. The study of the electro-surface properties (electrophoretic mobility, electrokinetic potential, pH, and electroconductivity) of mineral and soil particles adsorption-modified with PEs has confirmed the differences in the adsorption mechanisms (from physical sorption to chemisorption) with the formation of surface compounds depending on the different polar groups of PEs and the mineral type.

Kurochkina, G. N.; Pinskii, D. L.; Haynos, M.; Sokolowska, Z.; Tsesla, I.

2014-07-01

242

Adsorption of reovirus by minerals and soils.  

PubMed Central

Adsorption of [35S]methionine-labeled reovirus by 30 dry soils, minerals, and finely ground rocks suspended in synthetic freshwater at pH 7 was investigated to determine the conditions necessary for optimum virus removal during land application of wastewaters. All of the minerals and soils studied were excellent adsorbents of reovirus, with greater than 99% of the virus adsorbed after 1 h at 4 degrees C. Thereafter, virus remaining in suspension was significantly inactivated, and within 24 h a three to five log10 reduction in titer occurred. The presence of divalent cations, i.e., Ca2+ and Mg2+, in synthetic freshwater enhanced removal, whereas soluble organic matter decreased the amount of virus adsorbed in secondary effluent. The amount of virus adsorbed by these substrates was inversely correlated with the amount of organic matter, capacity to adsorb cationic polyelectrolyte, and electrophoretic mobility. Adsorption increased with increasing available surface area, as suspended infectivity was reduced further by the more finely divided substrates. However, the organic content of the soils reduced the level of infectious virus adsorbed below that expected from surface area measurements alone. The inverse correlation between virus adsorption and substrate capacity for cationic polyelectrolyte indicates that the adsorption of infectious reovirus particles is predominately a charged colloidal particle-charged surface interaction. Thus, adsorption of polyelectrolyte may be useful in predicting the fate of viruses during land application of sewage effluents and sludges. PMID:7149717

Moore, R S; Taylor, D H; Reddy, M M; Sturman, L S

1982-01-01

243

Mineral Detector for Igneous Rocks  

NASA Astrophysics Data System (ADS)

We present a Raman spectral analysis tool that uses machine learning algorithms to classify pure minerals in igneous rocks. Experiments show greater than 90% accuracy classifying a test set of pure minerals against a database of similar reference minerals using an artificial neural network. Efforts are currently underway to improve this tool for use as a mineral detector in rock samples, an important milestone toward autonomously classifying rocks based on spectral, and previous imaging work. Although pure mineral classification has been widely successful, applying the same methods to rocks is difficult because the spectra may represent a combination of multiple, and often competing, mineral signatures. In such cases some minerals may appear with more intensity than others resulting in masking of weaker minerals. Furthermore, with our particular spectrometer (852 nm excitation, ~50 micron spot size), minerals such as potassium feldspar fluoresce, both obscuring its characteristic Raman features and suppressing those of weaker minerals. For example, plagioclase and quartz, two key minerals for determining the composition of igneous rocks, are often hidden by minerals such as potassium feldspar and pyroxene, and are consequently underrepresented in the spectral analysis. These technicalities tend to skew the perceived composition of a rock from its actual composition. Despite these obstacles, an experiment involving a training set of 26 minerals (plagioclase, potassium feldspar, pyroxene, olivine, quartz) and a test set of 57 igneous rocks (basalt, gabbro, andesite, diorite, dacite, granodiorite, rhyolite, granite) shows that generalizations derived from their spectral data are consistent with expected trends: as rock composition goes from felsic to mafic there is a marked increase in the detection of minerals such as plagioclase and pyroxene along with a decrease in the detection of minerals such as quartz and potassium feldspar. The results suggest that phaneritic rocks are especially good candidates for compositional characterization based on spectral analysis. Aphanitic rocks, whose expected trends were not fully met due to the technicalities mentioned earlier, benefit from our previous imaging analysis work where visual attributes (texture and color) are obtained from color photos. Earlier experiments using 266 igneous rock samples (andesite, basalt, rhyolite, granite, granodiorite, and diorite) correctly classified rocks as felsic, intermediate, or mafic with 79%, 63%, and 58% accuracy, respectively [1]. [1] S. T. Ishikawa, V. C. Gulick. AGU 2008 Fall Mtg.

Ishikawa, S. T.; Hart, S. D.; Gulick, V. C.

2010-12-01

244

Protein- mediated enamel mineralization  

PubMed Central

Enamel is a hard nanocomposite bioceramic with significant resilience that protects the mammalian tooth from external physical and chemical damages. The remarkable mechanical properties of enamel are associated with its hierarchical structural organization and its thorough connection with underlying dentin. This dynamic mineralizing system offers scientists a wealth of information that allows the study of basic principals of organic matrix-mediated biomineralization and can potentially be utilized in the fields of material science and engineering for development and design of biomimetic materials. This chapter will provide a brief overview of enamel hierarchical structure and properties as well as the process and stages of amelogenesis. Particular emphasis is given to current knowledge of extracellular matrix protein and proteinases, and the structural chemistry of the matrix components and their putative functions. The chapter will conclude by discussing the potential of enamel for regrowth. PMID:22652761

Moradian-Oldak, Janet

2012-01-01

245

Minerals yearbook, 1988: Thorium  

SciTech Connect

Mine production of monazite, the principal source of thorium, decreased slightly in 1988. Associated Minerals (USA) Inc. was the only domestic monazite producer. Monazite produced in the United States was exported, and the thorium products used domestically were derived from imported materials, existing company stocks, and thorium nitrate released from the National Defense Stockpile. Major nonenergy uses were in refractory applications, ceramics, and mantles for incandescent lanterns. The only energy use of thorium in the United States was in the high-temperature gas-cooled (HTGC) nuclear reactor at Fort St. Vrain, CO. Topics discussed in the report include domestic data coverage, legislation and government programs, domestic production, consumption and uses, stocks, prices, foreign trade, world capacity, and world review--(Australia, Brazil, Madagascar, Mozambique).

Hedrick, J.B.

1988-01-01

246

Computer modelling of minerals  

NASA Astrophysics Data System (ADS)

We review briefly the methodology and achievements of computer simulation techniques in modelling structural and defect properties of inorganic solids. Special attention is paid to the role of interatomic potentials in such studies. We discuss the extension of the techniques to the modelling of minerals, and describe recent results on the study of structural properties of silicates. In a paper of this length, it is not possible to give a comprehensive survey of this field. We shall concentrate on the recent work of our own group. The reader should consult Tossell (1977), Gibbs (1982), and Busing (1970) for examples of other computational studies of inorganic solids. The techniques we discuss are all based on the principle of energy minimization. Simpler, "bridge-buildingrdquo procedures, based on known bond-lengths, of which distance least squares (DLS) techniques are the best known are discussed, for example, in Dempsey and Strens (1974).

Catlow, C. R. A.; Parker, S. C.

247

Mineralization by nanobacteria  

NASA Astrophysics Data System (ADS)

Nanobacteria are the smallest cell-walled bacteria, only recently discovered in human and cow blood and in commercial cell culture serum. In this study, we identified with energy-dispersive x-ray microanalysis and chemical analysis that all growth phases of nanobacteria produce biogenic apatite on their cell envelope. Fourier transform IR spectroscopy revealed the mineral as carbonate apatite. Previous models for stone formation have lead to a hypothesis that an elevated pH due to urease and/or alkaline phosphatase activity are important lithogenic factors. Our results indicate that carbonate apatite can be formed without these factors at pH 7.4 at physiological phosphate and calcium concentrations. Due to their specific macromolecules, nanobacteria can produce apatite very efficiency in media mimicking tissue fluids and glomerular filtrate and rapidly mineralizing most of available calcium and phosphate. This can be also monitored by (superscript 85)Sr incorporation and provides a unique model for in vitro studies on calcification. Recently, bacteria have been implicated in the formation of carbonate (hydroxy)fluorapatite in marine sediments. Apatite grains are found so commonly in sedimentary rocks that apatite is omitted in naming the stone. To prove that apatite and other minerals are formed by bacteria would implicate that the bacteria could be observed and their actions followed in stones. We have started to approach this in two ways. Firstly, by the use of sensitive methods for detecting specific bacterial components, like antigens, muramic acid and nucleic acids, that allow for detecting the presence of bacteria and, secondly, by follow-up of volatile bacterial metabolites observed by continuous monitoring with ion mobility spectrometry, IMCELL, working like an artificial, educatable smelling nose. The latter method might allow for remote real time detection of bacterial metabolism, a signature of life, in rocks via fractures of drillholes with or without injected substrate solutions. Nanobacteria may provide a model for primordial life-forms, such as replicating clay crystallites in a sandstone, where minerals and metal atoms associated to membranes, may play catalytic and structural roles reducing the number of enzymes and structural proteins needed for life. Such simple metabolic pathways may support the 10,000-fold slower growth rate of nanobacteria, as compared to the usual bacteria. They may also explain the endurability of this life-form in extreme environmental conditions. Altogether such properties do suggest that nanobacteria may have evolved from environmental sources, such a shot springs, to take advantage of the steady-state calcium and phosphate supply of the mammalian blood. Based upon our findings of nanobacteria, a novel theory for the early development of life, based on apatite-mediated chemistry on membranes selecting itself for its own catalytical machinery, is presented.

Kajander, E. Olavi; Bjorklund, Michael; Ciftcioglu, Neva

1998-07-01

248

Improving Cattle Health Through Trace Mineral Supplementation  

Microsoft Academic Search

A number of trace minerals are required by beef cattle. Feeds consumed by cattle may supply most trace minerals in adequate amounts. However, some minerals may be severely or at least marginally deficient in beef cattle diets. Even marginal mineral deficiencies can reduce growth, reproduction and\\/or health of cattle showing few if any clinical signs of deficiency. Other trace minerals

Jerry W. Spears

1995-01-01

249

Secondary Syphilitic Lesions  

PubMed Central

An important theme that emerges from all early historical accounts is that in addition to the decreased virulence of Treponema pallidum, the incidence of secondary syphilis has decreased drastically over the past three centuries. Even in the early 20th century, most syphilologists were of the opinion that the disease had undergone changes in its manifestations and that they were dealing with an attenuated form of the spirochete. Such opinions were based primarily on the observations that violent cutaneous reactions and fatalities associated with the secondary stage had become extremely rare. The rate of primary and secondary syphilis in the United States increased in 2002 for the second consecutive year. After a decade-long decline that led to an all-time low in 2000, the recent trend is attributable, to a large extent, by a increase in reported syphilis cases among men, particularly homosexual and bisexual men having sex with men. The present review addresses the clinical and diagnostic criteria for the recognition of secondary syphilis, the clinical course and manifestations of the disease if allowed to proceed past the primary stage of disease in untreated individuals, and the treatment for this stage of the disease. PMID:15653827

Baughn, Robert E.; Musher, Daniel M.

2005-01-01

250

Aircraft Electric Secondary Power  

NASA Technical Reports Server (NTRS)

Technologies resulted to aircraft power systems and aircraft in which all secondary power is supplied electrically are discussed. A high-voltage dc power generating system for fighter aircraft, permanent magnet motors and generators for aircraft, lightweight transformers, and the installation of electric generators on turbine engines are among the topics discussed.

1983-01-01

251

Modernising Portugal's Secondary Schools  

ERIC Educational Resources Information Center

Portugal has a total of 477 public secondary schools. Some date from the end of the 19th century but the majority were built after 1970, reflecting the period of expansion in the school network and the extension of compulsory schooling. The schools are heterogeneous in terms of building types, architectural features and quality. An assessment of…

Heitor, Teresa V.

2008-01-01

252

Secondary emission gas chamber  

E-print Network

For a hadron calorimeter active element there is considered a gaseous secondary emis-sion detector (150 micron gap, 50 kV/cm). Such one-stage parallel plate chamber must be a radiation hard, fast and simple. A model of such detector has been produced, tested and some characteristics are presented.

In'shakov, V; Skvortsov, V

2014-01-01

253

Secondary Services in Physics.  

ERIC Educational Resources Information Center

The basic characteristics of sixty-nine secondary services in physics were analyzed in terms of sponsorship and distribution by: (1) country of origin, (2) language, (3) age, (4) frequency of publication, (5) subject and geographical coverage and (6) size. The eight major services, in terms of size, are identified. The use of the services by the…

Cooper, Marianne; Terry, Edward

254

Subarctic weathering of mineral wastes provides a sink for atmospheric CO(2).  

PubMed

The mineral waste from some mines has the capacity to trap and store CO(2) within secondary carbonate minerals via the process of silicate weathering. Nesquehonite [MgCO(3)·3H(2)O] forms by weathering of Mg-silicate minerals in kimberlitic mine tailings at the Diavik Diamond Mine, Northwest Territories, Canada. Less abundant Na- and Ca-carbonate minerals precipitate from sewage treatment effluent deposited in the tailings storage facility. Radiocarbon and stable carbon and oxygen isotopes are used to assess the ability of mine tailings to trap and store modern CO(2) within these minerals in the arid, subarctic climate at Diavik. Stable isotopic data cannot always uniquely identify the source of carbon stored within minerals in this setting; however, radiocarbon isotopic data provide a reliable quantitative estimate for sequestration of modern carbon. At least 89% of the carbon trapped within secondary carbonate minerals at Diavik is derived from a modern source, either by direct uptake of atmospheric CO(2) or indirect uptake though the biosphere. Silicate weathering at Diavik is trapping 102-114 g C/m(2)/y within nesquehonite, which corresponds to a 2 orders of magnitude increase over the background rate of CO(2) uptake predicted from arctic and subarctic river catchment data. PMID:21854037

Wilson, Siobhan A; Dipple, Gregory M; Power, Ian M; Barker, Shaun L L; Fallon, Stewart J; Southam, Gordon

2011-09-15

255

Secondary impact hazard assessment  

NASA Technical Reports Server (NTRS)

A series of light gas gun shots (4 to 7 km/sec) were performed with 5 mg nylon and aluminum projectiles to determine the size, mass, velocity, and spatial distribution of spall and ejecta from a number of graphite/epoxy targets. Similar determinations were also performed on a few aluminum targets. Target thickness and material were chosen to be representative of proposed Space Station structure. The data from these shots and other information were used to predict the hazard to Space Station elements from secondary particles resulting from impacts of micrometeoroids and orbital debris on the Space Station. This hazard was quantified as an additional flux over and above the primary micrometeoroid and orbital debris flux that must be considered in the design process. In order to simplify the calculations, eject and spall mass were assumed to scale directly with the energy of the projectile. Other scaling systems may be closer to reality. The secondary particles considered are only those particles that may impact other structure immediately after the primary impact. The addition to the orbital debris problem from these primary impacts was not addressed. Data from this study should be fed into the orbital debris model to see if Space Station secondaries make a significant contribution to orbital debris. The hazard to a Space Station element from secondary particles above and beyond the micrometeoroid and orbital debris hazard is categorized in terms of two factors: (1) the 'view factor' of the element to other Space Station structure or the geometry of placement of the element, and (2) the sensitivity to damage, stated in terms of energy. Several example cases were chosen, the Space Station module windows, windows of a Shuttle docked to the Space Station, the habitat module walls, and the photovoltaic solar cell arrays. For the examples chosen the secondary flux contributed no more than 10 percent to the total flux (primary and secondary) above a given calculated critical energy. A key assumption in these calculations is that above a certain critical energy, significant damage will be done. This is not true for all structures. Double-walled, bumpered structures are an example for which damage may be reduced as energy goes up. The critical energy assumption is probably conservative, however, in terms of secondary damage. To understand why the secondary impacts seem to, in general, contribute less than 10 percent of the flux above a given critical energy, consider the case of a meteoroid impact of a given energy on a fixed, large surface. This impact results in a variety of secondary particles, all of which have much less energy than the original impact. Conservation of energy prohibits any other situation. Thus if damage is linked to a critical energy of a particle, the primary flux will always deliver particles of much greater energy. Even if all the secondary particles impacted other Space Station structures, none would have a kinetic energy more than a fraction of the primary impact energy.

1986-01-01

256

43 CFR 3000.8 - Management of Federal minerals from reserved mineral estates.  

Code of Federal Regulations, 2011 CFR

... 2011-10-01 false Management of Federal minerals from reserved mineral estates. 3000.8 Section 3000.8 Public...OF LAND MANAGEMENT, DEPARTMENT OF THE INTERIOR MINERALS MANAGEMENT (3000) MINERALS MANAGEMENT:...

2011-10-01

257

43 CFR 3594.5 - Minerals soluble in water; brines; minerals taken in solution.  

Code of Federal Regulations, 2011 CFR

... 2011-10-01 2011-10-01 false Minerals soluble in water; brines; minerals taken in solution. 3594.5 Section 3594...LAND MANAGEMENT, DEPARTMENT OF THE INTERIOR MINERALS MANAGEMENT (3000) SOLID MINERALS...

2011-10-01

258

Nitrogen mineralization in production agriculture  

Technology Transfer Automated Retrieval System (TEKTRAN)

Understanding the effects of N management and how it relates to the N cycle in soil ecosystems is essential to determining N availability. This manuscript describes the importance of N mineralization to production agriculture and introduces a special issue on “N Mineralization in Production Agricult...

259

Ways to defuse miners' anger  

SciTech Connect

The violence and riots which often occur with mining personnel are considered. The emotions and feelings which miners often experience because of their work environment are dealth with. From recognizing the pressures, the article then works to present methods to help defuse the miners' hostility and anger.

Not Available

1984-06-01

260

From Mountain Men to Miners.  

ERIC Educational Resources Information Center

Examines three of the changes wrought by coal mining: (1) the miner's working conditions; (2) the establishment of company towns; and (3) the violence that ensued when miners from Harlan County, Kentucky, referred to as "Bloody Harlan," tried to better their lives by joining labor unions. (CMK)

Stevens, Robert L.; Fogel, Jared A.

1999-01-01

261

Radioactivity in bottled mineral waters  

Microsoft Academic Search

Consumption of bottled mineral water is a growing practice and is sometimes a necessity rather than a choice. In this work, a study of the radioactive content of a wide selection of commercial bottled mineral waters for human intake was carried out. The origins of the analyzed waters were very different, coming from various locations in France, Portugal and Spain.

A Mart??n Sánchez; M. P Rubio Montero; V Gómez Escobar; M Jurado Vargas

1999-01-01

262

A Mineral Processing Field Course  

ERIC Educational Resources Information Center

This article describes a field course in Cornwall looking at mineral processing with the focus on the chemistry involved. The course was split into two parts. The first looked at tin mining based around Penzance. This involved visiting mines, hunting for mineral samples, carrying out a stream survey and visiting the Camborne School of Mines…

Carmody, Maurice

2014-01-01

263

Mineral Resources and the Environment.  

ERIC Educational Resources Information Center

This report presents the findings and recommendations of panels created by the Committee on Mineral Resources and the Environment (COMRATE) to study four topic areas of mineral resources and the environment. The topic areas studied by the panels were: technology, supply, the environment, and demand. Section I, the report of the technology panel,…

National Academy of Sciences, Washington, DC.

264

Mineral Cleavage: a practical experiment  

NSDL National Science Digital Library

In this geology activity, students investigate the physical property of mineral cleavage by physically trying to break down a block of halite and describing the results. This lab addresses many misunderstandings non-majors have about the physical properties of minerals and includes a brief write up of their conclusions.

Browning, Sharon

265

Evaporates, petroleum and mineral resources  

SciTech Connect

This book covers oxide minerals under the following topics: oxygen fugacity and its petrologic importance; crystal chemistry of oxides and oxyhydroxides; petrogenetic indicators; oxygen barometry of spinel peridotites; iron-titanium oxides in igneous rocks; oxide minerals in metamorphic rocks; and magnetic petrology.

Melvin, J.L.

1991-01-01

266

Variability of Minerals in Foods  

Microsoft Academic Search

Dietary guidance to the public stresses foods or food groups as specific sources of minerals such as calcium in dairy products, iron in meats and legumes, and potassium in oranges and bananas. Dietary guidance also identifies foods that are low in some minerals (such as sodium, potassium, calcium, cooper, and iron) for patients with specific disease conditions. However, the levels

Jean A. T. Pennington

267

Compensation of Navajo Uranium Miners  

NSDL National Science Digital Library

This site addresses policy issues of the compensation of Navajo uranium miners. The site provides an annotated index of current issues, legislation, papers and presentations, books, and links that lead to more information on uranium miners. Imbedded links throughout the text lead to related information.

World Information Service on Energy Uranium Project

268

Adverse possession of subsurface minerals  

SciTech Connect

Concepts applicable to adverse possession of subsurface minerals are generally the same as those that apply to adverse possession of all real estate. However, special requirements must be satisfied in order to perfect title to subsurface minerals by adverse possession, particularly when there has been a severance of the true title between surface and subsurface minerals. In those jurisdictions where senior and junior grants came from the state or commonwealth covering the same or some of the same land and in those areas where descriptions of land were vague or not carefully drawn, adverse possession serves to solidify land and mineral ownership. There may be some public, social, and economic justification in rewarding, with good title, those who take possession and use real estate for its intended use, including the extraction of subsurface minerals. 96 refernces.

Bowles, P.N.

1983-01-01

269

Pulmonary complications in lead miners  

SciTech Connect

We carried out a study to assess the prevalence of respiratory disease in lead miners and to investigate the roles of silica and lead. We used a questionnaire for symptoms and examinations for signs of respiratory disease, chest roentgenograms, and spirometric study in 45 lead miners. Six underwent bronchoscopy and transbronchial lung biopsy (TBB) and five lung lead analysis. Lung lead levels from five patients with no occupational lead exposure were obtained for comparison. Results showed restriction in five of 45 and reticulonodular opacities in 16 of 45 workers. Squamous metaplasia and other histopathologic changes were observed, although silicotic nodules were absent by TBB. Lung lead levels above those of control subjects were observed in four of five lead miners. These findings show that lead miners are at risk for lung disease. Although silica is a likely cause, elevated lung lead content found in these miners merits further investigation.

Masjedi, M.R.; Estineh, N.; Bahadori, M.; Alavi, M.; Sprince, N.L.

1989-07-01

270

Remote Sensing of Soils, Minerals, and Geomorphology  

E-print Network

the soil taxonomy (Petersen, 19Remote Sensing of Soils, Minerals, and Geomorphology Remote Sensing of Soils,Remote Sensing of Soils, Minerals, and GeomorphologyMinerals, and Geomorphology · 26% of the Earth's surface is exposed

271

Secondary aortoesophageal fistula.  

PubMed

Secondary aortoesophageal fistula is the rarest type of aortopeptic fistula, characterized by communication between the reconstructed aorta and the esophagus. This condition has been reported to be uniformly fatal, even after prompt diagnosis and treatment. We report what may be the first case of a successfully managed secondary aortoesophageal fistula that occurred 14 months after repair of a Crawford type II thoracoabdominal aortic aneurysm. The entity was diagnosed with a combination of esophagogastroduodenoscopy and aortography. At exploration, a communication between the proximal anastomosis and the esophagus with otherwise minimal mediastinal contamination was encountered. The anastomosis was replaced with an interposition polytetrafluoroethylene graft, and the esophageal defect was debrided, primarily closed, and reinforced with adjacent old aneurysm wall. There were no postoperative complications, and the patient remains well 18 months after fistula repair. PMID:9240335

Pipinos, I I; Reddy, D J

1997-07-01

272

[Mineral water as a cure].  

PubMed

The treatment of diseases with mineral spring water belongs to the oldest medical therapies. The "remedy" mineral water is therefore of importance also within the pharmacy. The present pharmacy historical work examines the impact of the use of mineral waters, as well as of their dried components, as therapeutic agents in the 19th and early 20th centuries, i.e. from approx. 1810 to 1930, as well as the contributions given by pharmacists in the development and analysis of mineral water springs. Beside these aspects, the aim here is also to describe the role played by pharmacists in the production of artificial mineral water as well as in the sale and wholesale of natural and artificial mineral water. In the first part of this work the situation in Switzerland and its surrounding countries, such as Germany, France, Italy and Austria, is discussed. The second part contains a case-study of the particular situation in the Canton Tessin. It is known from the scientific literature published at that time that information on mineral water was frequently reported. Starting from the beginning of the 19th century the number of such publications increased tremendously. The major part of them were publications in scientific journals or contributions to medical and pharmaceutical manuals and reference books. In particular the spa-related literature, such as spa-guides, was of growing interest to a broad public. The inclusion of monographs into the Swiss, the Cantonal as well the foreign pharmacopoeias granted a legal frame for the mineral waters and their dried components. These works are of major importance from a pharmacy historical standpoint and represent a unique proof of historical evidence of the old medicinal drug heritage. The most frequently used therapies based on mineral waters were drinking and bath cures. Several diseases, particularly those of a chronic character, were treated with mineral waters. The positive influence of these cures on the recovery of the patients was to attribute, on the one hand to the physico-chemical properties of the water and on the other hand to the climatic, nutritional and social factors characterising the selected health resort. All over Europe, pharmacists were dealing with mineral waters, among them even very famous names such as Klaproth, Trommsdorf, Lampadius and Fresenius. They were on one side involved in the development and analysis of the waters, while on the other side they were interested in their artificial production. Their knowledge and findings in the area of the mineral water source chemistry gave a crucial impetus to the future evolution of analytic chemistry. Following the improvements in the precision of analysis and classification of the composition of the mineral waters, the imitation of artificial mineral waters increased significantly. Certain pharmacists tried to copy well-known mineral waters in their properly furnished laboratories. At the same time, pharmacies were important sales points: natural and artificial mineral waters as well as their dried components were either sold there, or delivered upon prescription. In the second part of this work, specifically concerning the situation in the Canton Tessin, the most important local sources and spa resorts are described, as well as the analyses performed and the researchers involved. Moreover, the types of therapies used at that time are mentioned. The integration of the local mineral waters into the pharmacopoeia of the Canton Tessin, the Farmacopea Ticinese, is also discussed. Of particular interest are the delivery and the sale of mineral waters and their dried components by a local pharmacy. In the Canton Tessin, the five most frequented spa resorts were Acquarossa, Brissago, Craveggia, Rovio and Stabio. Craveggia spa resort is of course based in Italy; it has however been included in the present work due to its proximity to Switzerland and to a connected historical Substantial differences existed among the individual health resorts mentioned, especially regarding the quality and quantity aspects of the per

Nocco, Priska Binz

2008-01-01

273

Economic drivers of mineral supply  

USGS Publications Warehouse

The debate over the adequacy of future supplies of mineral resources continues in light of the growing use of mineral-based materials in the United States. According to the U.S. Geological Survey, the quantity of new materials utilized each year has dramatically increased from 161 million tons2 in 1900 to 3.2 billion tons in 2000. Of all the materials used during the 20th century in the United States, more than half were used in the last 25 years. With the Earth?s endowment of natural resources remaining constant, and increased demand for resources, economic theory states that as depletion approaches, prices rise. This study shows that many economic drivers (conditions that create an economic incentive for producers to act in a particular way) such as the impact of globalization, technological improvements, productivity increases, and efficient materials usage are at work simultaneously to impact minerals markets and supply. As a result of these economic drivers, the historical price trend of mineral prices3 in constant dollars has declined as demand has risen. When price is measured by the cost in human effort, the price trend also has been almost steadily downward. Although the United States economy continues its increasing mineral consumption trend, the supply of minerals has been able to keep pace. This study shows that in general supply has grown faster than demand, causing a declining trend in mineral prices.

Wagner, Lorie A.; Sullivan, Daniel E.; Sznopek, John L.

2003-01-01

274

LBT adaptive secondary electronics  

NASA Astrophysics Data System (ADS)

The adaptive secondary mirror is a fundamental part in the LBT adaptive optics architecture. The thin, continuous mirror is controlled by 672 electromagnetic actuators (voice coil motors) with local position feedback (capacitive sensor) and allows to perform from tip-tilt to high order wavefront correction, but also chopping. The adaptive secondary is controlled by a DSP-based dedicated electronics. The control electronics does not only implement the mirror position control tasks, but does also realize the Real Time Reconstructor (RTR). The control system, while maintaining a similar architecture to the MMT adaptive secondary one, shows a substantial enhancement in terms of computational power, rising in the range of hundreds of Gigaflops. This allows to minimize the computational time required to apply the wavefront correction pattern from the wavefront sensor acquisition, even in case of high order reconstructor dynamics. The electronics is housed in compact cooled crates placed in the adaptive secondary hub. Apart from the power supply lines, it is connected to the other components of the adaptive control system just through a very high speed fiber optic link, capable of 2.9 Gigabit/s of actual data throughput. The control system has been designed according to modular concept, so that the number of channels can be easily increased or reduced for adapting the electronics to different correctors. A substantial effort has been dedicated to the flexibility and on-field configurability of system. In this frame, the same electronics (or part of it) can be easily adapted to become the building block for the data processing unit required for Multi-Conjugated Adaptive Optics

Biasi, Roberto; Andrighettoni, Mario; Veronese, Daniele; Biliotti, Valdemaro; Fini, Luca; Riccardi, Armando; Mantegazza, Paolo; Gallieni, Daniele

2003-02-01

275

Nonaqueous secondary batteries  

Microsoft Academic Search

The object of the present invention is to make possible the repeated use for a long period of time of nonaqueous secondary battery that contains in the battery case a negative electrode of a carbonized organic substance, a positive electrode with Li(x)MO2 (where M is at least one of Co and Ni; x being 0.05 less than or = x

Takayuki Yamahira; Masanori Anzai

1991-01-01

276

Chronic Kidney Disease: Mineral and Bone Disorder in Children  

PubMed Central

Childhood and adolescence are crucial times for the development of a healthy skeletal and cardiovascular system. Disordered mineral and bone metabolism accompany chronic kidney disease (CKD) and present significant obstacles to optimal bone strength, final adult height, and cardiovascular health. Early increases in bone and plasma fibroblast growth factor 23 (FGF23) are associated with early defects in skeletal mineralization. Later in the course of CKD, secondary hyperparathyroidism—due to a combination of declining calcitriol values and phosphate retention—results in high turnover renal osteodystrophy while elevated levels of both phosphate and FGF23 contribute to cardiovascular disease. Treatment of hyperphosphatemia and secondary hyperparathyroidism improves high turnover bone disease but fails to correct defects in skeletal mineralization. Since overtreatment may result in adynamic bone disease, growth failure, hypercalcemia, and progression of cardiovascular calcifications, therapy must therefore be carefully titrated to maintain optimal serum biochemical parameters according to stage of CKD. Newer therapeutic agents and new treatment paradigms may effectively suppress serum PTH levels while limiting intestinal calcium absorption and skeletal FGF23 stimulation and may provide future therapeutic alternatives for children with CKD. PMID:23465503

Wesseling-Perry, Katherine; Salusky, Isidro B.

2014-01-01

277

Mindat.org: The Mineral Database  

NSDL National Science Digital Library

This database contains worldwide information on minerals, mineral localities and other mineralogical information. In part supported by advertising, it stores data on 25,000 different minerals, varieties and synonyms listed with over 4,000 valid mineral and mineraloid names. The database is searchable by name, properties, chemistry and locality. Many photographs and some maps are provided. Information is available on over 300,000 mineral occurrences worldwide with over 68,000 localities. Users can also submit their own data for new minerals or occurrences of minerals. Links are also provided to a chatroom, messageboard, and a clearinghouse that contains links to other sites dealing with mineral collection and study.

278

Mineral induction by immobilized phosphoproteins  

NASA Technical Reports Server (NTRS)

Dentin phosphoproteins are thought to have a primary role in the deposition of mineral on the collagen of dentin. In this study we determined the type of binding between collagen and phosphoproteins necessary for mineral formation onto collagen fibrils and whether the phosphate esters are required. Bovine dentin phosphophoryn or phosvitin from egg yolk were immobilized on reconstituted skin type I collagen fibrils by adsorption or by covalent cross-linking. In some samples the ester phosphate was removed from the covalently cross-linked phosphoproteins by treatment with acid phosphatase. All samples were incubated at 37 degrees C in metastable solutions that do not spontaneously precipitate. Reconstituted collagen fibrils alone did not induce mineral formation. The phosphoproteins adsorbed to the collagen fibrils desorbed when the mineralization medium was added, and mineral was not induced. The mineral induced by the cross-linked phosphoproteins was apatite, and the crystals were confined to the surface of the collagen fibrils. With decreasing medium saturation the time required for mineral induction increased. The interfacial tensions calculated for apatite formation by either phosphoprotein cross-linked to collagen were about the same as that for phosphatidic acid liposomes and hydroxyapatite. This similarity in values indicates that the nucleation potential of these highly phosphorylated surfaces is about the same. It is concluded that phosphoproteins must be irreversibly bound to collagen fibrils for the mineralization of the collagen network in solutions that do not spontaneously precipitate. The phosphate esters of phosphoproteins are required for mineral induction, and the carboxylate groups are not sufficient.

Saito, T.; Arsenault, A. L.; Yamauchi, M.; Kuboki, Y.; Crenshaw, M. A.

1997-01-01

279

Universal ripper miner  

DOEpatents

A universal ripper miner used to cut, collect and transfer material from an underground mine working face includes a cutter head that is vertically movable in an arcuate cutting cycle by means of drive members, such as hydraulically actuated pistons. The cutter head may support a circular cutter bit having a circular cutting edge that may be indexed to incrementally expose a fresh cutting edge. An automatic indexing system is disclosed wherein indexing occurs by means of a worm gear and indexing lever mechanism. The invention also contemplates a bi-directional bit holder enabling cutting to occur in both the upstroke and the downstroke cutting cycle. Another feature of the invention discloses multiple bits arranged in an in-line, radially staggered pattern, or a side-by-side pattern to increase the mining capacity in each cutting cycle. An on-board resharpening system is also disclosed for resharpening the cutting edge at the end of cutting stroke position. The aforementioned improvement features may be used either singly, or in any proposed combination with each other.

Morrell, Roger J. (Bloomington, MN); Larson, David A. (Minneapolis, MN)

1991-01-01

280

Moon's Pink Mineral  

NASA Astrophysics Data System (ADS)

Since the 2010 remote-sensing discovery of lunar regolith rich in Mg-Al spinel on the rims and central peaks of impact craters and inner rings of basins on the Moon, researchers have been designing experiments to better understand the origin and formation history of spinel-rich rocks and what they mean for the construction of the lunar crust. The newly detected rock type is referred to as pink spinel anorthosite, or PSA, due to high plagioclase and low abundance (<5%) of mafic minerals such as olivine and pyroxene. Two recent studies tested specific hypotheses of PSA production on the Moon. Juliane Gross (American Museum of Natural History and the Lunar and Planetary Institute, LPI) and colleagues at the LPI, University of Hawaii, and NASA Johnson Space Center conducted experiments to model the crystallization of spinel in impact melts from impact events. Tabb Prissel (Brown University) and colleagues from Brown conducted experiments to model a plutonic formation of spinel from magma-wallrock interactions. In each study, comparisons of the remote sensing data with Apollo lunar samples or lunar meteorites were crucial for testing the PSA formation hypotheses with the experimental results. Definitive answers aren't in yet. PSA could form from impact melting of the right target rocks. Equally likely is PSA formation by reaction of basaltic magma and crust. One big unknown is the effect space weathering has in determining the amount of spinel in the PSA..

Martel, L. M. V.; Taylor, G. J.

2014-12-01

281

Petroleum County Secondary Data Analysis  

E-print Network

Petroleum County Secondary Data Analysis July 23, 2012 1 Community Health Data, MT Dept American Diabetes Association (2012) Region 3 (South Central) ­ Judith Basin, Fergus, Petroleum* #12; Petroleum County Secondary Data Analysis July 23, 2012 2 Socioeconomic Measures1

Maxwell, Bruce D.

282

Secondary Education Graduate Program Manual  

E-print Network

Secondary Teacher Education Graduate Handbook 2014-2015 3 SECTION 2: INTERNSHIP RESOURCES Internship Forms 1Secondary Education Graduate Program Manual 2014-2015 The University of Vermont College it helpful. #12;UVM Secondary Teacher Education Graduate Handbook 2014-2015 2 University of Vermont College

Hayden, Nancy J.

283

Issues in secondary teacher preparation  

Microsoft Academic Search

As teacher educators who have had extensive experience working in the field?based secondary programs of two universities, the authors recognize the benefits, as well as the challenges, of forming partnerships with secondary educators to design and deliver collaboratively the teacher preparation program. In this article, experiences are shared and some of the major issues related to secondary teacher preparation that

Virginia Resta; Billy E. Askins; Leslie Huling

1999-01-01

284

Accelerated Growth Plate Mineralization and Foreshortened Proximal Limb Bones in Fetuin-A Knockout Mice  

PubMed Central

The plasma protein fetuin-A/alpha2-HS-glycoprotein (genetic symbol Ahsg) is a systemic inhibitor of extraskeletal mineralization, which is best underscored by the excessive mineral deposition found in various tissues of fetuin-A deficient mice on the calcification-prone genetic background DBA/2. Fetuin-A is known to accumulate in the bone matrix thus an effect of fetuin-A on skeletal mineralization is expected. We examined the bones of fetuin-A deficient mice maintained on a C57BL/6 genetic background to avoid bone disease secondary to renal calcification. Here, we show that fetuin-A deficient mice display normal trabecular bone mass in the spine, but increased cortical thickness in the femur. Bone material properties, as well as mineral and collagen characteristics of cortical bone were unaffected by the absence of fetuin-A. In contrast, the long bones especially proximal limb bones were severely stunted in fetuin-A deficient mice compared to wildtype littermates, resulting in increased biomechanical stability of fetuin-A deficient femora in three-point-bending tests. Elevated backscattered electron signal intensities reflected an increased mineral content in the growth plates of fetuin-A deficient long bones, corroborating its physiological role as an inhibitor of excessive mineralization in the growth plate cartilage matrix - a site of vigorous physiological mineralization. We show that in the case of fetuin-A deficiency, active mineralization inhibition is a necessity for proper long bone growth. PMID:23091616

Gupta, Himadri S.; Schäfer, Cora; Krauss, Stefanie; Dunlop, John W. C.; Masic, Admir; Kerschnitzki, Michael; Zaslansky, Paul; Boesecke, Peter; Catalá-Lehnen, Philip; Schinke, Thorsten; Fratzl, Peter; Jahnen-Dechent, Willi

2012-01-01

285

The mechanism of interface-coupled dissolution and precipitation during apparent non-stoichiometric mineral dissolution  

NASA Astrophysics Data System (ADS)

Understanding the mechanism of multicomponent mineral and glass dissolution is important in a wide range of natural (such as weathering) and technological (such as glass corrosion) processes, as well as being crucial in defining rate laws for mineral reactions. Atomic force microscopy (AFM) has been used to make in situ nanoscale observations and measurements, which confirm the formation of a cation depleted layer at the mineral-solution interface during dissolution of multicomponent minerals such as wollastonite, CaSiO3 and dolomite Ca,Mg(CO3)2 in water at acidic pH. Observations combined with compositional analysis of reaction fluids as well as mineral precipitates, give clear evidence that such a layer is formed in a two step process: 1. stoichiometric dissolution of the mineral surface and; 2. subsequent precipitation of a secondary phase from a supersaturated fluid boundary layer in contact with the mineral surface. Such a mechanism presents a new paradigm that differs from the concept of preferential leaching of cations, as postulated by most currently accepted dissolution models. Furthermore, this mechanism applies to any Earth situation where aqueous fluids are in contact with minerals and so will be the controlling mechanism in processes such as metamorphism, metasomatism and element sequestration, eg., CO2 sequestration.

Putnis, C. V.; Ruiz-Agudo, E.; Rodriguez-Navarro, C.; Putnis, A.

2012-04-01

286

Designing Clothing for Coal Miners  

ERIC Educational Resources Information Center

Describes procedures taken by apparel design students, working in an industrial setting, in designing functional clothing for coal miners as part of the Armco Steel Corporation's Student Design Program. (TA)

Watkins, Susan M.

1977-01-01

287

Mining, Minerals and Sustainable Development  

NSDL National Science Digital Library

The Mining, Minerals and Sustainable Development Project (MMSD) is a completed, independent two-year project of research and consultation seeking to understand how the mining and minerals sector can contribute to the global transition to sustainable development. The final report, as well as various regional reports, timelines, and working papers, are available in English, Spanish, French, and Portuguese. Information on a wide spectrum of topics is available, including the following: armed conflict; artisanal and small-scale mining; biodiversity; current industry practice; corporate citizenship; finance dialogue; health and safety; human rights; indigenous peoples; information dialogue; large-volume waste; life-cycle assessment; managing mineral wealth; mine closure policy; minerals availability; planning for outcomes; public participation; and resettlement and displacement.

2007-06-25

288

The Zapot pegmatite mineral county  

USGS Publications Warehouse

The Zapot pegmatite is currently being mined for mineral specimens (chiefly amazonite, topaz and smoky quartz in miarolitic cavities), for gemstones (topaz and smoky quartz) and for decorative rock (amazonite). The deposit is owned and operated by Harvey Gordon Minerals of Reno, Nevada, and is the only amazonite-topaz mining operation in the state. Thousands of specimens from this operation have reached the collector market.

Foord, E.E.; Soregaroli, A.E.; Gordon, H.M.

1999-01-01

289

Mineral deposit density; an update  

USGS Publications Warehouse

A robust method to estimate the number of undiscovered deposits is a form of mineral deposit model wherein numbers of deposits per unit area from well-explored regions are counted and the resulting frequency distribution is used either directly for an estimate or indirectly as a guideline in some other method. The 27 mineral deposit density estimates reported here for 13 different deposit types represent a start at compiling the estimates necessary to guide assessments.

Singer, Donald A.; Menzie, W. David; Sutphin, David M.; Mosier, Dan L.; Bliss, James D.; contributions to global mineral resource assessment research edited by Schulz, Klaus J.

2001-01-01

290

Mineral of the month: magnesium  

USGS Publications Warehouse

Magnesium, often confused with last month’s mineral of the month manganese, is valued primarily because of its light weight and high strength-to-weight ratio. Magnesium is the eighth most abundant element and constitutes about 2 percent of the Earth’s crust. It is the third most plentiful element dissolved in seawater, with a concentration averaging 0.13 percent. Magnesium is found in over 60 minerals, and also is recovered from seawater, wells, and lake brines and bitterns.

Kramer, Deborah A.

2005-01-01

291

Persulfate activation by subsurface minerals  

NASA Astrophysics Data System (ADS)

Persulfate dynamics in the presence of subsurface minerals was investigated as a basis for understanding persulfate activation for in situ chemical oxidation (ISCO). The mineral-mediated decomposition of persulfate and generation of oxidants and reductants was investigated with four iron and manganese oxides and two clay minerals at both low pH (< 7) and high pH (> 12). The manganese oxide birnessite was the most effective initiator of persulfate for degrading the oxidant probe nitrobenzene, indicating that oxidants are generated at both low and high pH regimes. The iron oxide goethite was the most effective mineral for degrading the reductant probe hexachloroethane. A natural soil and two soil fractions were used to confirm persulfate activation by synthetic minerals. The soil and soil fractions did not effectively promote the generation of oxidants or reductants. However, soil organic matter was found to promote reductant generation at high pH. The results of this research demonstrate that synthetic iron and manganese oxides can activate persulfate to generate reductants and oxidants; however, iron and manganese oxides in the natural soil studied do not show the same reactivity, most likely due to the lower masses of the metal oxides in the soil relative to the masses studied in isolated mineral systems.

Ahmad, Mushtaque; Teel, Amy L.; Watts, Richard J.

2010-06-01

292

Mineral Surface Directed Membrane Assembly  

NASA Astrophysics Data System (ADS)

The transition from non-living to living matter may have resulted from the self-organizing properties of organic molecules and their interactions with a chemically rich inorganic environment. We have shown that a solution containing RNA, fatty acids and clay produces structures that contain a potentially catalytic surface (clay) and a potential informational biopolymer (RNA) encapsulated within a membrane. This highlights the ability of mineral surfaces to bring together and organize key components of primordial life. We have extended our analysis of mineral-mediated vesicle catalysis to include other natural minerals and synthetic surfaces of varying shape, size, and charge density. Our results show that while RNA polymerization on minerals may be restricted to the surface environment provided by montmorillonite, vesicle formation is enhanced in the presence of disparate types of surfaces. A model is presented in which new sheets of amphiphiles form just proximal to a surface. Similar interactions between amphiphiles and minerals on early Earth may have resulted in the encapsulation of a diverse array of mineral particulates with catalytic properties.

Hanczyc, Martin M.; Mansy, Sheref S.; Szostak, Jack W.

2007-02-01

293

Fe-Ni metal and sulfide minerals in CM chondrites: An indicator for thermal history  

USGS Publications Warehouse

CM chondrites were subjected to aqueous alteration and, in some cases, to secondary metamorphic heating. The effects of these processes vary widely, and have mainly been documented in silicate phases. Herein, we report the characteristic features of Fe-Ni metal and sulfide phases in 13 CM and 2 CM-related chondrites to explore the thermal history of these chondrites. The texture and compositional distribution of the metal in CM are different from those in unequilibrated ordinary and CO chondrites, but most have similarities to those in highly primitive chondrites, such as CH, CR, and Acfer 094. We classified the CM samples into three categories based on metal composition and sulfide texture. Fe-Ni metal in category A is kamacite to martensite. Category B is characterized by pyrrhotite grains always containing blebs or lamellae of pentlandite. Opaque mineral assemblages of category C are typically kamacite, Ni-Co-rich metal, and pyrrhotite. These categories are closely related to the degree of secondary heating and are not related to degree of the aqueous alteration. The characteristic features of the opaque minerals can be explained by secondary heating processes after aqueous alteration. Category A CM chondrites are unheated, whereas those in category B experienced small degrees of secondary heating. CMs in category C were subjected to the most severe secondary heating process. Thus, opaque minerals can provide constraints on the thermal history for CM chondrites. ?? The Meteoritical Society, 2011.

Kimura, M.; Grossman, J.N.; Weisberg, M.K.

2011-01-01

294

Understanding mineral dusts from the Middle East  

NASA Astrophysics Data System (ADS)

The purpose of the program was to provide scientifically founded information on the chemical and physical properties of airborne mineral dust collected during a period of approximately one year, largely in 2006, at Djibouti, Afghanistan (Bagram, Khowst), Qatar, United Arab Emirates, Iraq (Balad, Baghdad, Tallil, Tikrit, Taji, Al Asad), and Kuwait (Northern, Central, Coastal, and Southern regions). To fully understand mineral dusts, their chemical and physical properties as well as mineralogical interrelationships were accurately established. Three collocated low volume particulate samplers, one each for the total suspended (TSP), less than 10 ?m in aerodynamic diameter (PM10), and less than 2.5 ?m in aerodynamic diameter (PM2.5) particulate matter were deployed at each of the 15 sites, operating on a "1 in 6 day" sampling schedule. A total of 3,136 filter samples were collected on a 1-in-6 day schedule, along with one-time bulk soil samples, at each of the 15 sites. Sample media included Teflon® membrane and quartz fiber filters for chemical analysis (71 species), and Nuclepore® filters for individual particle analysis by Scanning Electron Microscopy (SEM). The provisional study of the data revealed three broad air pollution sources: geological dust, smoke from burn pits, and until now unidentified lead-zinc smelters and battery-processing facilities. SEM results and secondary electron imagery show that quartz and other silicate minerals and, to a lesser extent, dolomite and calcite particles are coated by a thin Si-Al-Mg layer, probably the clay minerals palygorskite and/or montmorillonite/illite. Positive Matrix Factorization (PMF) was performed on aerosol samples collected at six military sites in Iraq (Balad, Baghdad, Tallil, Tikrit, Taji, and Al Asad). PMF results reflect chemical differences amongst sources impacting at individual sites, further complicated by the regional geomorphology and meteorology. Sampling sites are seldom impacted by one source at a time. Also, dust palls are continually being modified by added dust from soils across which they migrate, and by particle segregation in the dust plume followed by precipitation of the coarser particles. PMF was applied separately to two ambient data sets collected in Iraq in 2006, the one on Teflon membrane filters and the other on quartz fiber. Each of the filter types were previously analyzed for different chemical species: Teflon membrane for elements, by XRF and ICP-MS, while quartz fiber filters were analyzed for ions and carbon. A set of 392 Teflon filter samples analyzed for 25 elemental species was modeled by PMF. A five factor solution identified three soil factors, a silicate soil, limestone soil, and a gypsum soil, as well as a salt factor and an anthropogenic metal factor. Similarly, a set of 362 quartz filter samples analyzed for 10 selected chemical species was modeled by PMF. A five factor solution provided a limestone-gypsum soil, diesel combustion, secondary ammonium sulfate, salt and agricultural-burnpit combustion source type.

Engelbrecht, J. P.; McDonald, E.; Gillies, J. A.; Jayanty, J.; Casuccio, G.; Gertler, A.

2012-12-01

295

Minerals Arranged by the New Dana Classification  

NSDL National Science Digital Library

This directory provides a listing of mineral species based on Dana's New Mineralogy, in which a number is assigned to each class based on a combination of chemistry and crystal structure. Clicking on each class heading provides access to a list of each mineral that conforms to that class. Each mineral name is a link to additional information on the mineral.

Barthelmy, David

296

Historical Events in Minerals and Materials  

NSDL National Science Digital Library

These reports provide a review of significant changes that occurred during the twentieth century in industries requiring use of metals and industrial minerals. It includes a timeline and a summary that discusses major achievements in mineral production and events that affected the U.S. mineral industry. These events are related to overall U.S. mineral consumption and years of war or recession.

2011-07-11

297

1996 annual report on Alaska's mineral resources  

USGS Publications Warehouse

This is the fifteenth annual report that has been prepared in response to the Alaska National Interest Lands Conservation Act. Current Alaskan mineral projects and events that occurred during 1995 are summarized. For the purpose of this document, the term 'minerals' encompasses both energy resources (oil and gas, coal and peat, uranium, and geothermal) and nonfuel-mineral resources (metallic and industrial minerals).

Schneider, Jill L.

1997-01-01

298

Reforming Secondary Science Instruction  

NSDL National Science Digital Library

Science education reform can seem a daunting task to high school science teachers. So, you might ask, why should I be bothered? The answer is that today's students simply do not have the skill sets necessary for life in our global economy. Reforming Secondary Science Instruction offers detailed advice for changing your methods of teaching so that students are prepared for life and work. Follow along as your fellow teachers learn about inquiry, implement change strategies, try out innovative instructional materials, build professional learning communities and partnerships, use data from student assessments, and address the needs of linguistically diverse learners. The underlying message, as one author puts it, is "science education reform will not occur by simply adding occasional new activities to your teaching repertoire. Reform requires thought, work, and persistence." Every chapter offers you the opportunity to assess your own teaching techniques and find room for improvement. Whether you are early in your career or a seasoned professional, Reforming Secondary Science Instruction will help you craft a workable plan for giving your students the tools they need to succeed beyond your classroom.

2009-02-15

299

Equilibrium of Groundwater with Carbonate Minerals of the Water-Bearing Rocks under Anthropogenic Impact (by the example of Kishinev, Moldova)  

NASA Astrophysics Data System (ADS)

The paper presents calculation results of equilibrium of groundwater in Kishenev with a variety of secondary carbonate minerals. It is shown that the groundwater-rock system is in equilibrium with some minerals, such as calcite, magnesite, dolomite, siderite, but at the same time is not in equilibrium with strontianite. It indicates that secondary mineral precipitation is possible. Specific nitrate chemical water type, which is rarely observed in nature and characterized by the presence of anthropogenic impact in this territory, in some cases is of higher saturation as compared to calcite, dolomite and magnesite due to the fact that nitrate ion content increases with the increase of calcium content.

Timoshenkova, A. N.; Pasechnik, E. Yu; Tokarenko, O. G.

2014-08-01

300

Characterization of primary and secondary magnetite in marine sediment by combining chemical and magnetic unmixing techniques  

NASA Astrophysics Data System (ADS)

We present a novel technique for quantitative unmixing of primary and secondary ferrimagnetic minerals in sediments. Hysteresis and high-resolution first-order reversal curve (FORC) measurements are performed on sediment samples before and after digestion in a citrate-bicarbonate-dithionite (CBD) solution optimized for maximum selective extraction of secondary fine-grained iron oxides. The difference between magnetic measurements of untreated and CBD-treated sample materials is used to calculate the original magnetic signature of CBD-extractable minerals. A combination of selective chemical extraction and magnetic measurements suited for the detection of single-domain particles provides a cross-check between chemical and magnetic unmixing of primary and secondary iron oxides and resolves the non-uniqueness problem of numerical unmixing methods. A quantitative magnetic characterization of secondary ferrimagnetic minerals in a magnetofossil-rich pelagic carbonate is presented for the first time. It can be used for calibration of recently developed fast magnetic unmixing techniques. CBD-based Fe extraction from sediments with minimal clastic and/or aeolian inputs, such as pelagic carbonates, is particularly suited for the search for cosmogenic 60Fe signatures from supernova explosions, because 60Fe dilution by dissolved primary Fe-bearing minerals is minimized.

Ludwig, P.; Egli, R.; Bishop, S.; Chernenko, V.; Frederichs, T.; Rugel, G.; Merchel, S.; Orgeira, M. J.

2013-11-01

301

Biomineralization: mineral formation by organisms  

NASA Astrophysics Data System (ADS)

Organisms form many different types of minerals, with diverse shapes and sizes. These minerals fulfill a variety of functions. Inspired by the late H A Lowenstam, Steve Weiner and Lia Addadi have addressed many questions that relate to the mechanisms by which biological organisms produce these mineral phases and how their structures relate to their functions. Addadi and Weiner have explored the manner in which macromolecules extracted from mineralized tissues can interact with some crystal planes and not others, how these macromolecules can be occluded inside the forming crystals residing preferentially on specific crystal planes, and how they can induce one polymorph of calcium carbonate and not another to nucleate. Addadi and Weiner have also identified a novel strategy used by the sea urchin to form its smooth and convoluted mineralized skeletal elements. The strategy involves the initial production by cells of a highly disordered mineral precursor phase in vesicles, and then the export of this so-called amorphous phase to the site of skeletal formation, where it crystallizes. This strategy is now known to be used by many different invertebrate phyla, as well as by vertebrates to build bones and teeth. One of the major current research aims of the Weiner--Addadi group is to understand the biomineralization pathways whereby ions are extracted from the environment, are transported and deposited inside cells within vesicles, how these disordered phases are then transferred to the site of skeletal formation, and finally how the so-called amorphous phase crystallizes. Biology has clearly evolved unique strategies for forming crystalline minerals. Despite more than 300 years of research in this field, many challenging questions still remain unanswered.

Addadi, Lia; Weiner, Steve

2014-09-01

302

25 CFR 215.25 - Other minerals and deep-lying lead and zinc minerals.  

Code of Federal Regulations, 2013 CFR

...Other minerals and deep-lying lead and zinc minerals. 215.25 Section 215.25...INTERIOR ENERGY AND MINERALS LEAD AND ZINC MINING OPERATIONS AND LEASES, QUAPAW AGENCY...Other minerals and deep-lying lead and zinc minerals. Except as provided...

2013-04-01

303

25 CFR 215.25 - Other minerals and deep-lying lead and zinc minerals.  

...Other minerals and deep-lying lead and zinc minerals. 215.25 Section 215.25...INTERIOR ENERGY AND MINERALS LEAD AND ZINC MINING OPERATIONS AND LEASES, QUAPAW AGENCY...Other minerals and deep-lying lead and zinc minerals. Except as provided...

2014-04-01

304

25 CFR 215.25 - Other minerals and deep-lying lead and zinc minerals.  

Code of Federal Regulations, 2012 CFR

...Other minerals and deep-lying lead and zinc minerals. 215.25 Section 215.25...INTERIOR ENERGY AND MINERALS LEAD AND ZINC MINING OPERATIONS AND LEASES, QUAPAW AGENCY...Other minerals and deep-lying lead and zinc minerals. Except as provided...

2012-04-01

305

Quantifying elemental compositions of primary minerals from granitic rocks and saprolite within the Santa Catalina Mountain Critical Zone Observatory  

NASA Astrophysics Data System (ADS)

Granitic terrain comprises a significant area of the earth's land surface (>15%). Quantifying weathering processes involved in the transformation of granitic rock to saprolite and soil is central to understanding landscape evolution in these systems. The quantification of primary mineral composition is important for assessing subsequent mineral transformations and soil production. This study focuses on coupling detailed analysis of primary mineral composition to soil development across an array of field sites sampled from the Santa Catalina Mountain Critical Zone observatory (SCM-CZO) environmental gradient. The gradient spans substantial climate-driven shifts in vegetation, ranging from desert scrub to mixed conifer forests. The parent material is a combination of Precambrian and Tertiary aged granites and quartz diorite. Primary mineral type and composition are known to vary among the various aged granitic materials and this variability is hypothesized to manifest as significant variation in regolith forming processes across the SCM-CZO. To address this variability, the mineral composition and mineral formulae of rock and saprolite samples were determined by electron microprobe chemical analyses. The rocks were pre-dominantly quartz, biotite, muscovite, orthoclase and calcium/sodium-rich plagioclase feldspars. Trace minerals observed in the samples included sphene, rutile, zircon, garnet, ilmenite, and apatite. Mineral formulae from electron microprobe analyses were combined with quantitative x-ray diffraction (QXRD) and x-ray fluorescence (XRF) data to quantify both primary and secondary mineralogical components in soil profiles from each of the field sites. Further, electron microprobe analyses of <2mm mixed conifer saprolite revealed weathered plagioclase grains coated with clay-sized particles enriched in silica and aluminum (~25% and 15%, respectively), suggesting kaolin as the secondary phase. The coatings were interspersed within each plagioclase grain, a strong indicator that the grain was transforming in situ to secondary weathering products. Other feldspar minerals in the sample appeared relatively un-weathered and were contained within perthite structural units where the plagioclase minerals were preserved as intergrowths of the orthoclase groundmasses. These results suggest differential plagioclase weathering pathways that may have resulted from variations in physical erosion rates or different geologic configurations of the feldspar minerals. Secondary mineral assemblages of the sample included kaolinite, dehydrated halloysite, illite, vermiculite, chlorite and gibbsite, indicating chemical alteration of both micas and feldspars. Current research is focused on additional electron microprobe analyses of surface and saprolite samples from other field areas along the gradient. The electron microprobe data aided in the constraint of chemical weathering processes as related to primary mineral composition.

Lybrand, R. A.; Rasmussen, C.

2011-12-01

306

Hyperspectral analysis of clay minerals  

NASA Astrophysics Data System (ADS)

A study was carried out by collecting soil samples from parts of Gwalior and Shivpuri district, Madhya Pradesh in order to assess the dominant clay mineral of these soils using hyperspectral data, as 0.4 to 2.5 ?m spectral range provides abundant and unique information about many important earth-surface minerals. Understanding the spectral response along with the soil chemical properties can provide important clues for retrieval of mineralogical soil properties. The soil samples were collected based on stratified random sampling approach and dominant clay minerals were identified through XRD analysis. The absorption feature parameters like depth, width, area and asymmetry of the absorption peaks were derived from spectral profile of soil samples through DISPEC tool. The derived absorption feature parameters were used as inputs for modelling the dominant soil clay mineral present in the unknown samples using Random forest approach which resulted in kappa accuracy of 0.795. Besides, an attempt was made to classify the Hyperion data using Spectral Angle Mapper (SAM) algorithm with an overall accuracy of 68.43 %. Results showed that kaolinite was the dominant mineral present in the soils followed by montmorillonite in the study area.

Janaki Rama Suresh, G.; Sreenivas, K.; Sivasamy, R.

2014-11-01

307

GMT adaptive secondary design  

NASA Astrophysics Data System (ADS)

The GMT adaptive secondary mirror (ASM) is based on a "segmented" concept following the primary segment layout: seven 1.05m diameter circular, independent adaptive mirrors are fed by the primaries and focus to the main telescope focal stations. The adaptive unit's design is based on the consolidated thin mirror, contactless technology already employed in several units (MMT, LBT, Magellan, VLT and one of the proposed E-ELT M4 designs), but nevertheless the mirror's topology reveals several design challenges. In particular, the off-axis units are strongly aspheric and therefore they require aspheric shaping of both thin mirror surfaces and of the thick reference body. The strong tilt of the off-axis units forced us to consider a peculiar fine positioning hexapod design, maximizing its stiffness and also implementing a special design of the last three rings of actuators to remain within the prescribed obstruction. From the control point of view, the actuator density of the adaptive mirrors is remarkably lower than in all previous units: 672 actuators with 36mm spacing compared to 30mm typical separation adopted so far. This choice is validated by static and dynamic performance computation though a sophisticated numerical simulator based on a full state space model incorporating mechanics, control and fluid dynamics. The control system fulfills the dimensional constraints of the unit. The design has completed the feasibility phase, including the cost estimate. The choice of making the GMT adaptive secondary mirrors similar to the already existing ones strongly reduces the implementation risks and allows shortening the remaining design path.

Biasi, R.; Veronese, D.; Andrighettoni, M.; Angerer, G.; Gallieni, D.; Mantegazza, M.; Tintori, M.; Lazzarini, P.; Manetti, M.; Johns, M. W.; Hinz, P. M.; Kern, J.

2010-07-01

308

Copper isotopes as monitors of redox processes in hydrothermal mineralization  

NASA Astrophysics Data System (ADS)

The stable copper isotope composition of 79 samples of primary and secondary copper minerals from hydrothermal veins in the Schwarzwald mining district, South Germany, shows a wide variation in ?65Cu ranging from -2.92 to 2.41‰. We investigated primary chalcopyrite, various kinds of fahlores and emplectite, as well as supergene native copper, malachite, azurite, cuprite, tenorite, olivenite, pseudomalachite and chrysocolla. Fresh primary Cu(I) ores have at most localities copper isotope ratios ( ?65Cu values) of 0 ± 0.5‰ despite the fact that the samples come from mineralogically different types of deposits covering an area of about 100 by 50 km and that they formed during three different mineralization events spanning the last 300 Ma. Relics of the primary ores in oxidized samples (i.e., chalcopyrite relics in an iron oxide matrix with an outer malachite coating) display low isotope ratios down to -2.92‰. Secondary Cu(I) minerals such as cuprite have high ?65Cu values between 0.4 and 1.65‰, whereas secondary Cu(II) minerals such as malachite show a range of values between -1.55 and 2.41‰, but typically have values above +0.5‰. Within single samples, supergene oxidation of fresh chalcopyrite with a ? value of 0‰ causes significant fractionation on the scale of a centimetre between malachite (up to 1.49‰) and relict chalcopyrite (down to -2.92‰). The results show that—with only two notable exceptions—high-temperature hydrothermal processes did not lead to significant and correlatable variations in copper isotope ratios within a large mining district mineralized over a long period of time. Conversely, low-temperature redox processes seriously affect the copper isotope compositions of hydrothermal copper ores. While details of the redox processes are not yet understood, we interpret the range in compositions found in both primary Cu(I) and secondary Cu(II) minerals as a result of two competing controls on the isotope fractionation process: within-fluid control, i.e., the fractionation during the redox process among dissolved species, and fluid-solid control, i.e., fractionation during precipitation involving reactions between dissolved Cu species and minerals. Additionally, Rayleigh fractionation in a closed system may be responsible for some of the spread in isotope compositions. Our study indicates that copper isotope variations may be used to decipher details of natural redox processes and therefore may have some bearing on exploration, evaluation and exploitation of copper deposits. On the other hand, copper isotope analyses of single archeological artefacts or geological or biological objects cannot be easily used as reliable fingerprint for the source of copper, because the variation caused by redox processes within a single deposit is usually much larger than the inter-deposit variation.

Markl, Gregor; Lahaye, Yann; Schwinn, Gregor

2006-08-01

309

Microtextured surfaces with gradient wetting properties.  

PubMed

Patterned surfaces with microwrinkled surface structures were prepared by thermally evaporating thin aluminum (10-300 nm thick) (Al) layers onto thick prestrained layers of a silicone elastomer and subsequently releasing the strain. This resulted in the formation of sinusoidal periodic surface wrinkles with characteristic wavelengths in the 3-42 ?m range and amplitudes as large as 3.6 ± 0.4 ?m. The Al thickness dependence of the wrinkle wavelengths and amplitudes was determined for different values of the applied prestrain and compared to a recent large-amplitude deflection theory of wrinkle formation. The results were found to be in good agreement with theory. Samples with spatial gradients in wrinkle wavelength and amplitude were also produced by applying mechanical strain gradients to the silicone elastomer layers prior to deposition of the Al capping layers. Sessile water droplets that were placed on these surfaces were found to have contact angles that were dependent upon their position. Moreover, these samples were shown to direct the motion of small water droplets when the substrates were vibrated. PMID:21028810

Langley, Kevin R; Sharp, James S

2010-12-01

310

Mineral arsenicals in traditional medicines: Orpiment, realgar, and arsenolite  

PubMed Central

Mineral arsenicals have long been used in traditional medicines for various diseases, yet arsenic can be highly toxic and carcinogenic. Arsenic in traditional medicines typically comes from deliberate addition for therapeutic purposes, mainly in the form of mineral arsenicals including orpiment (As2S3), realgar (As4S4), and arsenolite (contains arsenic trioxide, As2O3). Inorganic arsenic is now accepted in Western medicine as a first line chemotherapeutic agent against certain hematopoietic cancers. This minireview analyzes the pharmacology and toxicology of these arsenicals used in traditional medicines. Orpiment and realgar are less soluble and poorly absorbed from the gastrointestinal tract, while the bioavailability of arsenic trioxide is similar to inorganic arsenic salts like sodium arsenite. Pharmacological studies show that arsenic trioxide and realgar are effective against certain malignancies. Orpiment and realgar are used externally for various skin diseases. Realgar is frequently included as an ingredient in oral traditional remedies for its antipyretic, antiinflammatory, antiulcer, anticonvulsive and anti-schistosmiasis actions, but the pharmacological basis for this inclusion still remains to be fully justified. Toxicological studies show that cardiovascular toxicity is the major concern for arsenic trioxide, and the gastrointestinal and dermal adverse effects may occur after prolonged use of mineral arsenicals. Little is known about possible secondary cancers resulting from the long-term use of any of these arsenicals. Similar to the safety evaluation of seafood arsenicals, total arsenic content alone appears to be insufficient for mineral arsenical safety evaluation. Arsenic speciation, bioavailability, and toxicity/benefit should be considered in evaluation of mineral arsenical-containing traditional medicines. PMID:18463319

Liu, Jie; Lu, Yuanfu; Wu, Qin; Goyer, Robert A; Waalkes, Michael P.

2009-01-01

311

Plants and microorganisms as drivers of mineral weathering  

NASA Astrophysics Data System (ADS)

Plants and microorganisms play important role in mineral weathering and soil formation modifying their environment to make it more hospitable for life. This presentation summarizes several collaborative studies that focused on understanding how interactions between plants and microorganisms, where plants provide the energy through photosynthesis, drive mineral weathering and result in soil formation. Plants influence weathering through multiple mechanisms that have been previously established, such as increase in CO2 concentration in the soil through root respiration and degradation of plant residues and exudates by heterotrophic microorganisms, release of organic acids that promote mineral dissolution, removal of weathering products from soil solution through uptake, and water redistribution. Weathering processes result in nutrient release that satisfies immediate needs of the plants and microorganisms, as well as precipitation of secondary phases, that provide surfaces for retention of nutrients and organic carbon accumulation. What makes understanding contribution of plants and microorganisms, such as bacteria and fungi, to mineral weathering challenging is the fact that they closely interact, enhancing and amplifying each other's contribution. In order to address multiple processes that contribute to and result from biological weathering a combination of chemical, biological, mineralogical, and computational techniques and methodologies is needed. This complex array of methodologies includes bulk techniques, such as determination of total dissolved organic and inorganic carbon and nitrogen, ion chromatography and high performance liquid chromatography to characterize amount and composition of exuded organic acids, inductively coupled plasma mass spectrometry to determine concentrations of lithogenic elements in solution, X-ray diffraction to characterize changes in mineral composition of the material, DNA extraction to characterize community structure, as well as microscopic techniques. These techniques in combination with numerical geochemical modeling are being employed to improve our understanding of biological weathering.

Dontsova, K.; Chorover, J.; Maier, R.; Hunt, E.; Zaharescu, D. G.

2011-12-01

312

43 CFR 3873.1 - Segregation of mineral from non-mineral land.  

Code of Federal Regulations, 2011 CFR

...2011-10-01 2011-10-01 false Segregation of mineral from non-mineral land. 3873.1 Section 3873.1 Public Lands...OF LAND MANAGEMENT, DEPARTMENT OF THE INTERIOR MINERALS MANAGEMENT (3000) ADVERSE CLAIMS, PROTESTS...

2011-10-01

313

43 CFR 3814.2 - Mineral reservation in patent; conditions to be noted on mineral applications.  

Code of Federal Regulations, 2011 CFR

...2011-10-01 2011-10-01 false Mineral reservation in patent; conditions to be noted on mineral applications. 3814.2 Section 3814...MANAGEMENT, DEPARTMENT OF THE INTERIOR MINERALS MANAGEMENT (3000) LANDS AND...

2011-10-01

314

Nucleoside phosphorylation by phosphate minerals.  

PubMed

In the presence of formamide, crystal phosphate minerals may act as phosphate donors to nucleosides, yielding both 5'- and, to a lesser extent, 3'-phosphorylated forms. With the mineral Libethenite the formation of 5'-AMP can be as high as 6% of the adenosine input and last for at least 10(3) h. At high concentrations, soluble non-mineral phosphate donors (KH(2)PO(4) or 5'-CMP) afford 2'- and 2':3'-cyclic AMP in addition to 5'-and 3'-AMP. The phosphate minerals analyzed were Herderite Ca[BePO(4)F], Hureaulite Mn(2+)(5)(PO(3)(OH)(2)(PO(4))(2)(H(2)O)(4), Libethenite Cu(2+)(2)(PO(4))(OH), Pyromorphite Pb(5)(PO(4))(3)Cl, Turquoise Cu(2+)Al(6)(PO(4))(4)(OH)(8)(H(2)O)(4), Fluorapatite Ca(5)(PO(4))(3)F, Hydroxylapatite Ca(5)(PO(4))(3)OH, Vivianite Fe(2+)(3)(PO(4))(2)(H(2)O)(8), Cornetite Cu(2+)(3)(PO(4))(OH)(3), Pseudomalachite Cu(2+)(5)(PO(4))(2)(OH)(4), Reichenbachite Cu(2+)(5)(PO(4))(2)(OH)(4), and Ludjibaite Cu(2+)(5)(PO(4))(2)(OH)(4)). Based on their behavior in the formamide-driven nucleoside phosphorylation reaction, these minerals can be characterized as: 1) inactive, 2) low level phosphorylating agents, or 3) active phosphorylating agents. Instances were detected (Libethenite and Hydroxylapatite) in which phosphorylation occurs on the mineral surface, followed by release of the phosphorylated compounds. Libethenite and Cornetite markedly protect the beta-glycosidic bond. Thus, activated nucleic monomers can form in a liquid non-aqueous environment in conditions compatible with the thermodynamics of polymerization, providing a solution to the standard-state Gibbs free energy change (DeltaG degrees ') problem, the major obstacle for polymerizations in the liquid phase in plausible prebiotic scenarios. PMID:17412692

Costanzo, Giovanna; Saladino, Raffaele; Crestini, Claudia; Ciciriello, Fabiana; Di Mauro, Ernesto

2007-06-01

315

Iron phase transformations resulting from the respiration of Shewanella putrefaciens on a mixed mineral phase  

NASA Astrophysics Data System (ADS)

The initial Fe(III) minerals and the secondary mineralization products of Shewanella putrefaciens CN32 grown in the presence of dissolved phosphate and a commercial Fe(III) oxide, nominally nanoparticulate lepidocrocite, were determined using XRD and XAFS. The starting material was transformed by the bacteria from a reddish brown, rust colour mineral to a dark green phase over 90 days. Acid extraction of the bioreduced solids with 0.75 M HCl recovered 83% of the total iron as Fe(II), leaving a solid, acid-resistant phase. The latter was identified as nanoparticulate hematite by EXAFS. Subsequently, the starting Fe(III) phase was determined to be a mixture of 60% lepidocrocite, 26% ferrihydrite, and 14% hematite, using linear combination EXAFS analysis. For the acid-extractable phase, XANES and EXAFS indicated a predominantly Fe(II) valence state and a spectrum consistent with a mixture of brucite-type minerals(e.g., green rust or ferrous hydroxide) and siderite. The observed transformations suggest that in this mixed-mineral system, lepidocrocite and ferrihydrite are readily reducible to green rust and siderite, whereas hematite is less amenable to bacterial reduction. This study also demonstrates the utility of XAFS spectroscopy in the quantitative characterization of dissimilatory metal transformations, particularly in complex systems such as nanoparticulate minerals in hydrated mineral-bacteria assemblages.

Boyanov, M. I.; O'Loughlin, E. J.; Kemner, K. M.

2009-11-01

316

Bone Mineral Density and Logarithms  

NSDL National Science Digital Library

Students examine an image produced by a cabinet x-ray system to determine if it is a quality bone mineral density image. They write in their journals about what they need to know to be able to make this judgment. Students learn about what bone mineral density is, how a BMD image can be obtained, and how it is related to the x-ray field. Students examine the process used to obtain a BMD image and how this process is related to mathematics, primarily through logarithmic functions. They study the relationship between logarithms and exponents, the properties of logarithms, common and natural logarithms, solving exponential equations and Beer's law.

Vu Bioengineering Ret Program

317

Comparative study of stream sediments and heavy mineral concentrates using SEM-based Automated Mineralogy (QEMSCAN) from remote areas of Northern Pakistan  

NASA Astrophysics Data System (ADS)

This study investigates the usefulness of QEMSCAN for mineralogical analysis of stream sediments and heavy mineral concentrates. This study was an orientation study of known and lesser understood gold-rich prospect areas in northern Pakistan. Mineralogical anomalies in this area are more obvious in heavy mineral concentrates than stream sediments from both known and lesser known areas, probably as a result of dilution by glacial material. The sampling strategy involved the collection of stream sediments (<180 ?m) and panned concentrates (<180 ?m) from known Shoghor and Bagrot prospects and lesser understood areas such as Asheriat, Teru and Pakora where the sources of the anomalies were unknown. Samples from all areas were analysed by conventional ICP-MS and XRF, as well as detailed physiochemical study of gold grains observed in panned concentrates. A selected number (16) of samples from stream sediments and heavy minerals were subjected to advance mineralogical analysis using QEMSCAN. Data were output on the modal mineralogy and mineral associations for both heavy mineral concentrates and stream sediments. The mineral proportions and associations in the heavy mineral concentrates (<180 ?m) from the Shoghor and Bagrot catchments were characteristic of their known styles of mineralization, containing stibnite, galena, chalcopyrite and arsenopyrite, along with secondary minerals such as PbSbO (probably bindheimite) and SbO (possibly stibiconite). The modal abundances and associations of sulphide minerals and also secondary phases were better detected in the heavy mineral concentrates than stream sediments as concentrations of the latter were often below detection limits. The known Pb-Sb mineralization in Shoghor was well defined by modal mineralogy and mineral associations of rare minerals including stibnite, galena and also secondary phases such as SbO and PbSbO. Furthermore indication of similar types of mineralization have been found in heavy mineral concentrates from the lesser known Asheriat, Teru and Pakora areas. Results from both media indicated the mineralogy of sources and are useful to mineral exploration, either on their own or in combination with conventional geochemical methods. However the panned concentrates give more useful information than stream sediments and is recommended for detailed study of sulphide minerals, although costs are currently high (~£250 per sample). Detection limits for automated mineralogy are comparable to those of ICP-MS for transition metals.

ALI, L.; Williamson, B.; Moon, C. J.; Rollinson, G.; Shah, M. T.

2012-12-01

318

Bone metabolism and risk of secondary hyperparathyroidism 12 months after gastric banding in obese pre-menopausal women  

Microsoft Academic Search

OBJECTIVE: To evaluate, during the first postoperative year in obese pre-menopausal women, the effects of laparoscopic gastric banding on calcium and vitamin D metabolism, the potential modifications of bone mineral content and bone mineral density, and the risk of development of secondary hyperparathyroidism.SUBJECTS: Thirty-one obese pre-menopausal women aged between 25 and 52 y with a mean body mass index (BMI)

N Pugnale; V Giusti; M Suter; E Zysset; E Héraïef; R C Gaillard; P Burckhardt

2003-01-01

319

A new approach for measuring dissolution rates of silicate minerals by using silicon isotopes  

NASA Astrophysics Data System (ADS)

The two major problems in measuring dissolution rates under close-to-natural conditions in laboratory experiments are: (1) our inability to measure small differences in concentration between solutions with relatively high concentrations and (2) the inherent problem that the change in solution concentration is affected by both the dissolution of the primary mineral and the precipitation of secondary minerals. The present manuscript proposes and tests a novel method, "the isotope ratio method", for measuring slow dissolution rates of silicate minerals by measuring the change in the ratios between stable isotopes of silicon of a spiked solution. Based on mass balance calculations, two equations that describe the dissolution rate of a silicate mineral in a batch reactor and in a flow-through reactor at steady-state are developed. The precipitation rate of the secondary mineral may be calculated by subtracting the release rate of Si that was calculated using isotope dilution from the rate that was calculated using the proposed isotope ratio method. Numerical simulations of flow-through and batch experiments demonstrate that the "isotope ratio method" is significantly more precise than conventional methods. The analytical uncertainty for the determination of dissolution rates was found to be low for the entire range of reported field-based dissolution rates. The calculation showed that even relatively large isotopic fractionations (up to ? values of 20‰), introduce insignificant uncertainties. Preliminary flow-through experiments support the above conclusion that dissolution rate may be obtained accurately and with small uncertainty using the proposed "isotope ratio method".

Gruber, Chen; Harpaz, Liat; Zhu, Chen; Bullen, Tom D.; Ganor, Jiwchar

2013-03-01

320

The early mineralization of enamel  

Microsoft Academic Search

Summary The potassium pyroantimonate technique was used to study the cellular distribution of calcium during the early mineralization of enamel in rat molar tooth germs at the electron microscope level. Differing patterns of calcium distribution were observed in the ameloblast seemingly associated with the appearance of Tomes' process. In the early secretory ameloblast calcium pyroantimonate deposits were observed within the

D. A. Deporter

1977-01-01

321

Crystallizing Minerals from Aqueous Solutions  

NSDL National Science Digital Library

Students dissolve selected salts and other compounds in water, let the water evaporate for about three weeks, and examine the crystals that grow. Students then draw crystal shapes and discuss the experiment. Discussion can include why and how crystals grow from solutions, why some minerals dissolve well and others do not, concepts of symmetry, and crystal systems and point groups.

Perkins, Dexter

322

77 FR 56273 - Conflict Minerals  

Federal Register 2010, 2011, 2012, 2013

...issuer would be required to provide information...provided alternative factors, such as the year...the determining factor for deciding for...has to provide its required conflict minerals information. We are making this revision because...control over this decision. Thus, this...

2012-09-12

323

Detrital Mineral Grains in Tektites.  

PubMed

Abundant detrital crystalline mineral grains have been found in layered Muong Nong-type indochinite tektites from Nong Sapong, northeastern Thailand. These grains are an integral part of some tektite layers, and their presence furnishes strong presumptive evidence that indochinites, as well as other tektite groups in which layered specimens occur, formed from surficial earth materials. PMID:17834370

Bairnes, V E

1963-12-27

324

Mineral of the month: rhenium  

USGS Publications Warehouse

Rhenium, an exotic, heat-resistant metal, has grown in importance since its discovery nearly 80 years ago. First isolated by a team of German chemists studying a platinum ore, the mineral was named for the Rhine River. From then until the 1960s, only 2 metric tons of rhenium were produced worldwide. In 2004, worldwide production was 40 metric tons.

Magyar, Michael J.

2005-01-01

325

Mineral of the month: boron  

USGS Publications Warehouse

What does boron have to do with baseball, apple pie, motherhood and Chevrolet? Boron minerals and chemicals are used in the tanning of leather baseballs and gloves; in micro-fertilizer to grow apples and in the glass and enamels of bakewares to cook apple pie; in boron detergents for soaking baby clothes and diapers; and in fiberglass parts for the Chevrolet Corvette.

Lyday, Phyllis A.

2005-01-01

326

Mineral of the month: titanium  

USGS Publications Warehouse

From paint to airplanes, titanium is important in a number of applications. Commercial production comes from titanium-bearing ilmenite, rutile and leucoxene (altered ilmenite). These minerals are used to produce titanium dioxide pigment, as well as an assortment of metal and chemical products.

Gambogi, Joseph

2004-01-01

327

Mineral of the month: indium  

USGS Publications Warehouse

Indium was discovered in Germany in 1863. Although it is a lustrous silver-white color, the finders named the new material for the “indigo” spectral lines the mineral created on the spectrograph. Indium ranks 61st in abundance in Earth’s crust and is about three times more abundant than silver or mercury.

George, Micheal W.

2004-01-01

328

Mineral of the month: aggregates  

USGS Publications Warehouse

Natural aggregates, consisting of crushed stone, and sand and gravel, are a major contributor to economic health, and have an amazing variety of uses. Aggregates are among the most abundant mineral resources and are major basic raw materials used by construction, agriculture and other industries that employ complex chemical and metallurgical processes.

Tepordei, Valentin V.

2005-01-01

329

Mysterious Lava Mineral on Mars  

NASA Technical Reports Server (NTRS)

This graph or spectrum captured by the Moessbauer spectrometer onboard the Mars Exploration Rover Spirit shows the presence of three different iron-bearing minerals in the soil at the rover's landing site. One of these minerals has been identified as olivine, a shiny green rock commonly found in lava on Earth. The other two have yet to be pinned down. Scientists were puzzled by the discovery of olivine because it implies the soil consists at least partially of ground up rocks that have not been weathered or chemically altered. The black line in this graph represents the original data; the three colored regions denote individual minerals and add up to equal the black line.

The Moessbauer spectrometer uses two pieces of radioactive cobalt-57, each about the size of pencil erasers, to determine with a high degree of accuracy the composition and abundance of iron-bearing minerals in martian rocks and soil. It is located on the rover's instrument deployment device, or 'arm.'

2004-01-01

330

Language Study in Secondary Education.  

ERIC Educational Resources Information Center

Calls for the study of language in secondary schools, discusses components of language study, notes the failure of the Bullock Report to point out the importance of language study, and discusses four characteristics of language that could serve as starting points for the study of language in secondary schools. (GT)

Stork, F. C.

1980-01-01

331

Carbon County Secondary Data Analysis  

E-print Network

Carbon County Secondary Data Analysis July 23, 2012 1 1 Community Health Data, MT Dept, Wheatland, Golden Valley, Musselshell, Sweet Grass, Stillwater, Yellowstone, Big Horn, and Carbon. CLRD* #12; Carbon County Secondary Data Analysis July 23, 2012 2 Socioeconomic Measures1

Maxwell, Bruce D.

332

INDUCED SECONDARY COMBUSTION IN WOODSTOVES  

EPA Science Inventory

The paper provides information useful for woodstove designers concerned with reducing emissions. A dual-chamber woodstove was modified to induce secondary combustion by utilizing an ignition source and forced flow of secondary air. The ignition source was an electric glow plug in...

333

Performance Art at Secondary Level  

ERIC Educational Resources Information Center

This article considers the far-reaching potential and the particular characteristics of performance art within the secondary art curriculum. It discusses the means by which an art department has incorporated it into their teaching curriculum at a state secondary school with reference to installations and the work of different performance artists…

Horn, Sheridan

2009-01-01

334

Mineralogy and temporal relations of coexisting authigenic minerals in altered silicic tuffs and their utility as potential low-temperature dateable minerals  

NASA Astrophysics Data System (ADS)

Coexisting fine-grained (0.1-20 ?m) authigenic silicate minerals separated from altered tuffs in Miocene and Plio-Pleistocene lacustrine deposits were characterized petrographically and using X-ray powder diffraction. The authigenic minerals are dominated by clinoptilolite, erionite, phillipsite, K-feldspar, silica, calcite, smectite, and randomly interstratified illite/smectite. Minor accessories of opal-CT, cristobalite, and barite are present with the major alteration minerals. Authigenic minerals from altered tuffs were dated using the {K}/{Ar} method to evaluate the utility of these minerals for determining the time of alteration in low-temperature diagenetic environments. The eruption ages of some of these zeolite-rich tuffs were determined using the {40Ar }/{39Ar } method on single sanidine and plagioclase minerals. The {K}/{Ar} isotopic ages of the fine-grained K-feldspar show minimal variation compared with results from the clinoptilolite separates. The isotopic ages from the authigenic K-feldspar (15-13.8 Ma) and some of the zeolites (16.-6.7 Ma) are similar to the eruption ages of the tuffs and indicate early alteration. Despite their open-framework structure, zeolites apparently can retain part or all of their radiogenic argon under favorable conditions (e.g., saturated environment). How much of the radiogenic argon is retained is estimated from the isotopic ages of other coexisting secondary minerals that are commonly dated by the {K}/{Ar} method. Although zeolite isotopic ages should be interpreted with caution, they may be useful to constrain temporal relations of low-temperature diagenetic processes when used in conjunction with other dateable minerals.

WoldeGabriel, Giday; Broxton, David E.; Byers, Frank M.

1996-05-01

335

Effects of biological molecules on calcium mineral formation associated with wastewater desalination as assessed using small-angle neutron scattering.  

PubMed

Calcium phosphate scale formation on reverse osmosis (RO) membranes is one of the main limitations on cost-effective desalination of domestic wastewater worldwide. It has been shown that organic agents affect mineralization. In this study, we explored mineralization in the presence of two biofilm-relevant organic compounds, the proteins bovine serum albumin (BSA) and lysozyme, in a simulated secondary effluent (SSE) solution using small-angle neutron scattering (SANS), and applied the results to analyses of mineral precipitation in RO desalination of secondary effluents of wastewater. The two proteins are prominent members of bacterial extracellular polymeric substances (EPSs), forming biofilms that are frequently associated with RO-membrane fouling during wastewater desalination. Laboratory experiments showed that both proteins in SSE solution are involved in complex mineralization processes. Only small portions of both protein fractions are involved in mineralization processes, whereas most of the protein fractions remain as monomers in solution. Contrast variation showed that composite particles of mineral and protein are formed instantaneously to a radius of gyration of about 300 Å, coexisting with particles of about ?m size. After about one day, these large particles start to grow again at the expense of the 300 Å particles. The volume fraction of the 300 Å particles is of the order of 2 × 10(-4), which is too large to represent calcium phosphate such as hydroxyapatite as the only mineral present. Considering the data of mineral volume fraction obtained here as well as the solubility product of possible mineral polymorphs in the SSE solution, we suggest the formation of protein-mineral particles of hydroxyapatite and calcium carbonate during scale formation. PMID:23701483

Pipich, Vitaliy; Dahdal, Yara; Rapaport, Hanna; Kasher, Roni; Oren, Yoram; Schwahn, Dietmar

2013-06-25

336

Control Dewar Secondary Vacuum Container  

SciTech Connect

This engineering note provides background information regarding the control dewar secondary vacuum container. The secondary vacuum container has it's origin with the CDP control dewar design. The name secondary vacuum container replaced the CDP term 'Watt can' which was named after Bob Watt (SLAC), a PAC/DOE review committee member who participated in a review of CDP and recommended a secondary vacuum enclosure. One of the most fragile parts of the control dewar design is the ceramic electrical feed throughs located in the secondary vacuum container. The secondary vacuum container is provided to guard against potential leaks in these ceramic insulating feed throughs. The secondary vacuum container has a pumping line separate from the main solenoid/control dewar insulating vacuum. This pumping line is connected to the inlet of the turbo pump for initial pumpdown. Under normal operation the container is isolated. Should a feedthrough develop a small leak, alternate pumping arrangements for the secondary vacuum container could be arranged. The pressure in the secondary vacuum container should be kept in a range that the breakdown voltage is kept at a maximum. The breakdown voltage is known to be a function of pressure and is described by a Paschen curve. I cannot find a copy of the curve at this time, but from what I remember, the breakdown voltage is a minimum somewhere around 10-3 torr. Ideally the pressure in the secondary vacuum can should be kept very low, around 10 E-6 or 10 E-7 torr for maximum breakdown voltage. If however a leak developed and this was not possible, then one could operate at a pressure higher than the minima point.

Rucinski, R.; /Fermilab

1993-10-04

337

Rare metal mineralization of calcite carbonatites from the Cape Verde Archipelago  

Microsoft Academic Search

Rare metal mineralization of oceanic carbonatites was studied for the first time by the example of calcite carbonatite from\\u000a Fogo Island in the Cape Verde Archipelago. The following evolutionary sequence of rare metal minerals was established: zirconolite-Th-calciobetafite-betafite\\u000a + Th-pyrochlore-thorite + Ti-Zr-Nb silicates + zircon.\\u000a \\u000a Schematic reactions were proposed for zirconolite transformation to secondary phases: (Ca,Th,U)Zr(Ti,Nb)2O7 (zirconolite) + SiO2 + Ca(F,OH)2

L. N. Kogarko; N. V. Sorokhtina; V. A. Zaitsev; V. G. Senin

2009-01-01

338

Mineral Dissolution and Precipitation due to Carbon Dioxide-Water-Rock Interactions: The Significance of Accessory Minerals in Carbonate Reservoirs (Invited)  

NASA Astrophysics Data System (ADS)

Accessory minerals in carbonate reservoirs, and in the caprocks that seal these reservoirs, can provide insight into multiphase fluid (CO2 + H2O)-rock interactions and the behavior of CO2 that resides in these water-rock systems. Our program integrates field data, hydrothermal experiments, and geochemical modeling to evaluate CO2-water-rock reactions and processes in a variety of carbonate reservoirs in the Rocky Mountain region of the US. These studies provide insights into a wide range of geologic environments, including natural CO2 reservoirs, geologic carbon sequestration, engineered geothermal systems, enhanced oil and gas recovery, and unconventional hydrocarbon resources. One suite of experiments evaluates the Madison Limestone on the Moxa Arch, Southwest Wyoming, a sulfur-rich natural CO2 reservoir. Mineral textures and geochemical features developed in the experiments suggest that carbonate minerals which constitute the natural reservoir will initially dissolve in response to emplacement of CO2. Euhedral, bladed anhydrite concomitantly precipitates in response to injected CO2. Analogous anhydrite is observed in drill core, suggesting that secondary anhydrite in the natural reservoir may be related to emplacement of CO2 into the Madison Limestone. Carbonate minerals ultimately re-precipitate, and anhydrite dissolves, as the rock buffers the acidity and reasserts geochemical control. Another suite of experiments emulates injection of CO2 for enhanced oil recovery in the Desert Creek Limestone (Paradox Formation), Paradox Basin, Southeast Utah. Euhedral iron oxyhydroxides (hematite) precipitate at pH 4.5 to 5 and low Eh (approximately -0.1 V) as a consequence of water-rock reaction. Injection of CO2 decreases pH to approximately 3.5 and increases Eh by approximately 0.1 V, yielding secondary mineralization of euhedral pyrite instead of iron oxyhydroxides. Carbonate minerals also dissolve and ultimately re-precipitate, as determined by experiments in the Madison Limestone, but pyrite will persist and iron oxyhydroxides will not recrystallize.

Kaszuba, J. P.; Marcon, V.; Chopping, C.

2013-12-01

339

Different forms of DMP1 play distinct roles in mineralization.  

PubMed

Dentin matrix protein-1 (DMP1) is a major synthetic product of hypertrophic chondrocytes and osteocytes. Previous in vitro studies showed full-length DMP1 inhibits hydroxyapatite (HA) formation and growth, while its N-terminal fragment (37K) promotes HA formation. Since there are 3 fragments within the mineralized tissues [N-terminal, C-terminal (57K), and a chondroitin-sulfate-linked N-terminal fragment (DMP1-PG)], we predicted that each would have a distinct effect on mineralization related to its interaction with HA. In a gelatin-gel system, 37K and 57K fragments were both promoters of HA formation and growth; DMP1-PG was an inhibitor. The secondary structures of the 3 fragments and the full-length protein in the presence and absence of Ca2+ and HA determined by FTIR showed that the full-length protein undergoes slight conformational changes on binding to HA, while 37K, 57K, and DMP1-PG do not change conformation. These findings indicate that distinct forms of DMP1 may work collectively in controlling the mineralization process. PMID:20200415

Gericke, A; Qin, C; Sun, Y; Redfern, R; Redfern, D; Fujimoto, Y; Taleb, H; Butler, W T; Boskey, A L

2010-04-01

340

Lowering respirable dust exposures at mineral processing facilities  

SciTech Connect

This article discusses three research projects performed by the National Institute for Occupational Safety and Health (formerly the Bureau of Mines), that reduce the respirable dust exposure of plant workers at mineral processing facilities. All three of these projects are very different but they all have same goal of reducing worker exposure to respirable dust at mineral processing facilities. The first project deals with a total mill ventilation system that reduces dust levels throughout an entire building and lowers the dust exposure of everyone working in the structure. The second project describes a bag and belt cleaner device that reduces the amount of dust on the outside of bags of product and primarily reduces the dust exposure of the bag stackers, as well as anyone handling the bags until their end use. The third project discusses how to reduce a worker's dust exposure from secondary dust sources through improved work practices. This area of research can potentially impact all workers at these facilities. All three of these research projects have been shown to significantly reduce the dust exposure of workers at mineral processing facilities.

Cecala, A.B.; Timko, R.J.; Thimons, E.D.

1999-07-01

341

21 CFR 573.680 - Mineral oil.  

Code of Federal Regulations, 2011 CFR

...mineral supplements. (2) To serve as a lubricant in the preparation of pellets, cubes, or blocks and to improve resistance to moisture of such pellets, cubes, or blocks. (3) To prevent the segregation of trace minerals in...

2011-04-01

342

21 CFR 573.680 - Mineral oil.  

...mineral supplements. (2) To serve as a lubricant in the preparation of pellets, cubes, or blocks and to improve resistance to moisture of such pellets, cubes, or blocks. (3) To prevent the segregation of trace minerals in...

2014-04-01

343

21 CFR 573.680 - Mineral oil.  

Code of Federal Regulations, 2010 CFR

...mineral supplements. (2) To serve as a lubricant in the preparation of pellets, cubes, or blocks and to improve resistance to moisture of such pellets, cubes, or blocks. (3) To prevent the segregation of trace minerals in...

2010-04-01

344

21 CFR 573.680 - Mineral oil.  

Code of Federal Regulations, 2013 CFR

...mineral supplements. (2) To serve as a lubricant in the preparation of pellets, cubes, or blocks and to improve resistance to moisture of such pellets, cubes, or blocks. (3) To prevent the segregation of trace minerals in...

2013-04-01

345

21 CFR 573.680 - Mineral oil.  

Code of Federal Regulations, 2012 CFR

...mineral supplements. (2) To serve as a lubricant in the preparation of pellets, cubes, or blocks and to improve resistance to moisture of such pellets, cubes, or blocks. (3) To prevent the segregation of trace minerals in...

2012-04-01

346

Ectopic mineralization of articular cartilage in the bullfrog Rana catesbeiana and its possible involvement in bone closure.  

PubMed

Mineralization of the articular cartilage is a pathological condition associated with age and certain joint diseases in humans and other mammals. In this work, we describe a physiological process of articular cartilage mineralization in bullfrogs. Articular cartilage of the proximal and distal ends of the femur and of the proximal end of the tibia-fibula was studied in animals of different ages. Mineralization of the articular cartilage was detected in animals at 1 month post-transformation. This mineralization, which appeared before the hypertrophic cartilage showed any calcium deposition, began at a restricted site in the lateral expansion of the cartilage and then progressed to other areas of the epiphyseal cartilage. Mineralized structures were identified by von Kossa's staining and by in vivo incorporation of calcein green. Element analysis showed that calcium crystals consisted of poorly crystalline hydroxyapatite. Mineralized matrix was initially spherical structures that generally coalesced after a certain size to occupy larger areas of the cartilage. Alkaline phosphatase activity was detected at the plasma membrane of nearby chondrocytes and in extracellular matrix. Apoptosis was detected by the TUNEL (TDT-mediated dUTP-biotin nick end-labeling) reaction in some articular chondrocytes from mineralized areas. The area occupied by calcium crystals increased significantly in older animals, especially in areas under compression. Ultrastructural analyses showed clusters of needle-like crystals in the extracellular matrix around the chondrocytes and large blocks of mineralized matrix. In 4-year-old animals, some lamellar bone (containing bone marrow) occurred in the same area as articular cartilage mineralization. These results show that the articular cartilage of R. catesbeiana undergoes precocious and progressive mineralization that is apparently stimulated by compressive forces. We suggest that this mineralization is involved in the closure of bone extremities, since mineralization appears to precede the formation of a rudimentary secondary center of ossification in older animals. PMID:11904772

Felisbino, Sérgio L; Carvalho, Hernandes F

2002-03-01

347

Simulating the Changes of Minerals and Elements under Chemical Weathering by Acid Hydrothermal Experiments  

NASA Astrophysics Data System (ADS)

In paleoenvironmental research, previous investigations reveal that the intensity of chemical weathering can be inferred from the elemental variations of marine or lacustrine sediments. Different kinds of rocks from Taiwan were applied in hydrothermal experiments to simulate element proportions and leaching sequence under chemical weathering. In our experiments, powder samples (2g) are treated in sulfuric acid solutions (20 ml) of 0.05M and 0.5M at 150°C for 1, 4, 7, 14, 30 and 60 days, respectively. We can further discuss mineral alteration and relative elemental migration according to the experimental results. There is no obvious variation in mineral phase and element at 0.05M, but the results of 0.5M have significant variations. The elemental contents are affected by the mineral leaching and secondary mineral deposited, so we use XRD and SEM to identify the existence of secondary minerals and their compositions. Our research exhibits that K/Rb, Ti/Al and Rb/Sr ratios show similar trend in most parent rocks (i.e. granite, andesite, quartz sandstone, calcite sandstone and mudstone) at 0.5M long-term experiments; however, the CIA value, was generally used as the proxy of chemical weathering, keep in a stable condition. The K/Rb and Ti/Al ratio increase, but Rb/Sr ratio decreases. In contrast, the actinolite schist and serpentinite show the different result. It is probably caused by the major mineral, chlorite and serpentinite in the rocks. We conclude that the major element Ti is relatively stable. Therefore, we use each element divided by Ti for judging relatively enriched or depleted under chemical weathering processes. Finally, we find that K/Rb ratio, which has obvious variations, is seldom influenced by mineral assemblage, so it can be regarded as a suitable weathering proxy.

Lo, F.; Chen, H.

2013-12-01

348

Problem of secondary porosity: Frio Formation (Oligocene), Texas Gulf Coast  

NASA Astrophysics Data System (ADS)

Secondary porosity, formed by the dissolution of both carbonate and silicate minerals, especially K-feldspars, is widely developed in sandstones of the Frio Formation (Oligocene) in the Texas Gulf Coast. CO2 produced by decarboxylation of organic matter is commonly suggested as the acid required for dissolution. Material balance calculations indicate that CO2 produced by decarboxylation of organic matter in Frio Formation shales can account for a regional average of only 1% or 2% secondary porosity in Frio Formation sandstones, yet point-count data indicate an average of 10% secondary porosity. Long-distance fluid transport (many kilometres) and/or other mechanisms of acid generation should, therefore, be considered. Carbon isotopic data on dissolved inorganic carbon in formation water, CO2 in produced natural gas, and carbonate cements indicate that CO2 produced by decarboxylation had a minor impact on these carbon reservoirs. The reaction kerogen + water ? methane + carbon dioxide can explain the isotopic data, but alone it is insufficient to account for all the secondary porosity unless long-distance material transport is involved.

Lundegard, Paul D.; Land, Lynton S.; Galloway, William E.

1984-07-01

349

Geochemical Zoning in Metamorphic Minerals  

NASA Astrophysics Data System (ADS)

Rocks encode the sum of Earth processes that affected them during their "lifetimes," and the purpose of most geological studies is to invert that information to refine our understanding of those processes. A metamorphic rock records not just a peak P-T condition, a single cooling rate, or a simple texture, but rather has undergone an evolving history of changes in P and T, mineral abundances, rim compositions, and textures, acting over its metamorphic lifespan, in response to heat flow, stress and strain, and inter- and intragranular movement of material. The greatest advances in understanding metamorphic rocks have been achieved through a recognition that metamorphism is a continuum, and by collection of data and development of models that directly address these continuum processes. Of the many approaches for investigating and interpreting metamorphic rocks, one of the most important is the characterization and quantitative modeling of geochemical zoning in metamorphic minerals. Geochemical zoning is particularly useful, because it is a quasicontinuous record of these metamorphic processes.There have been several previous reviews of chemical zoning in metamorphic minerals (e.g., Tracy, 1982; Loomis, 1983; Chakraborty and Ganguly, 1991; Spear, 1993). This review differs from them in three ways.(i) A catalogue was not compiled of all the minerals that exhibit zonation, and of the elements that are zoned. Although some minerals may be more obviously zoned than others, all minerals must be zoned in some element or isotope at some scale, and it is simply a matter of time before that zonation is described.(ii) Emphasis is placed on theoretical models of zoning, and these are illustrated with one or two of the best natural examples. Some other examples of zonation are also discussed which are particularly relevant to other endeavors, or hold special promise for future research.(iii) A large body of information, mostly collected since the early 1990s, is presented for trace element, stable isotope, and radiogenic isotope zoning.Garnet (Grt) is overwhelmingly favored for geochemical zoning studies, in part because it is commonly zoned in major and trace elements as well as in stable and radiogenic isotopes, but also because its chemistry, geochemical partitioning behavior, and physical shape are readily modeled theoretically. Other minerals are also zoned, but most are not as amenable to study or modeling. For these reasons, garnet is a major focus of this review. Emphasis is placed on theory and principles rather than on documentation, so extrapolation to other minerals and other chemical systems should be possible. The information is organized into four sections: major elements, stable isotopes, trace elements, and radiogenic isotopes. Most theory has been developed for the distribution of the major elements, but studies of the other types of zoning are becoming increasingly common, and deserve separate subsections in this review.This chapter does not cover analytical techniques, and assumes that the reader is at least moderately familiar with the electron microprobe, ion microprobe, and laser ablation-inductively coupled plasma mass spectrometry (LA-ICPMS), as well as with the distinction between X-ray mapping and spot analysis by electron microprobe. Mineral abbreviations are after Kretz (1983).

Kohn, M. J.

2003-12-01

350

How microbes influence mineral growth and dissolution  

Microsoft Academic Search

Mineral formation or dissolution is exploited by microbes if it favors their survival. Some microbes are able to dissolve a mineral by using it: (1) as a source of energy, (2) as a terminal electron acceptor in respiration, (3) as a trace element requirement, or (4) to enhance competitiveness in a microbial community. Some others form minerals: (1) in the

Henry L. Ehrlich

1996-01-01

351

Carbon dioxide sequestration by mineral carbonation  

Microsoft Academic Search

The increasing atmospheric carbon dioxide (CO2) concentration, mainly caused by fossil fuel combustion, has lead to concerns about global warming. A possible technology that can contribute to the reduction of carbon dioxide emissions is CO2 sequestration by mineral carbonation. The basic concept behind mineral CO2 sequestration is the mimicking of natural weathering processes in which calcium or magnesium containing minerals

W. J. J. Huijgen; R. N. J. Comans

2007-01-01

352

Observe common objects made of minerals  

NSDL National Science Digital Library

This interactive Earth science resource lets students first see six images of minerals and then, by placing their cursor over each image, an image of an everyday object made from that mineral. Quartz, gypsum, and fluorite are among the minerals shown, with the corresponding familiar objects being glass, drywall (Sheetrock), and toothpaste. Copyright 2005 Eisenhower National Clearinghouse

Education, Terc. C.; Littell, Mcdougal

2003-01-01

353

PROGRAM AND ABSTRACTS FOR CLAY MINERALS SOCIETY  

E-print Network

r PROGRAM AND ABSTRACTS FOR CLAY MINERALS SOCIETY 28th ANNUAL MEETING NI\\SI\\National Aeronautit &II LPI #12;PROGRAM AND ABSTRACTS FOR CLAY MINERALS SOCIETY 28th ANNUAL MEETING Houston, Texas October contains abstracts that have been accepted for presentation at the Clay Minerals Society 28th Annual

Rathbun, Julie A.

354

Minerals yearbook vol. III : area reports international  

USGS Publications Warehouse

This volume of the Minerals Yearbook provides an annual review of mineral production and trade and of mineral-related government and industry developments in more than 175 foreign countries. Each report includes sections on government policies and programs, environmental issues, trade and production data, industry structure and ownership, commodity sector developments, infrastructure, and a summary outlook.

U.S. Geological Survey

0000-01-01

355

Minerals by Physical and Optical Properties  

NSDL National Science Digital Library

This is a listing of mineral species arranged by physical and optical properties: hardness, streak, and luster; density; cleavage and fracture; refractive index; or color. Clicking on each property provides access to a list of minerals exhibiting that property; clicking on each mineral name provides access to more detailed information about it.

Barthelmy, David

356

Minerals yearbook, 1990: Utah. Annual report  

Microsoft Academic Search

The report has been prepared under a Memorandum of Understanding between the U.S. Bureau of Mines, U.S. Department of the Interior, and the Utah Geological and Mineral Survey for collecting information on all nonfuel minerals. Utah mines continued to increase their production of nonfuel minerals in 1990. The total value of output increased about 3% over that of the previous

M. N. Greeley; R. W. Gloyn

1992-01-01

357

Recordof Mineral Aerosolsand Their Roleinthe Earth System  

E-print Network

, feldspars, and calcite, clay minerals rich in elements such as aluminum, and oxides and hydroxides rich4.13 Recordof Mineral Aerosolsand Their Roleinthe Earth System K.E. Kohfeld Simon Fraser University dust is a type of mineral aerosol, and comprises one component of the total atmos- pheric aerosol

Kohfeld, Karen

358

Rock-Forming Minerals in Thin Section  

NSDL National Science Digital Library

This page is designed to display some of the most significant features of minerals viewed in thin section, and to show the most conspicuous features of major rock-forming minerals. A description of optical properties, specific mineral images, and discrimination tables are provided.

Dutch, Steven

359

Mineralization Potential of Polarized Dental Enamel  

PubMed Central

Background Management of human teeth has moved from a surgical to a more conservative approach of inhibiting or preventing lesion progression. Increasing enamel mineralization is crucial in this regard. A potential difficulty is the preferential mineralization of the outermost portion of the enamel that can prevent overall mineralization. We describe a strategy for increasing the mineralization potential of dental enamel. Methodology/Principal Findings Extracted human premolar teeth enamel (n?=?5) were exposed to a high concentration of hydrogen peroxide with an energizing source. Samples were stored in artificial saliva at 37°C for 1 wk. A desktop X-ray micro-CT system was used to evaluate the mineral density of samples. Mineral distribution was polarized between the lower and the higher mineralized portion of enamel by charged oxygen free radicals due to activation of permeated hydrogen peroxide. The kinetics of energy absorption in the deeper enamel region demonstrated improvement of preferential mineralization into the region without restricting overall mineralization of the enamel. Subsequent increasing mineralization, even in the dense mineralized outer portion of enamel, was also achieved. Conclusions/Significance This increased mineralization may promote resistance to acidic deterioration of the structure. The present study is one of the primary steps towards the development of novel application in reparative and restorative dentistry. PMID:19543391

Tanaka, Reina; Shibata, Yo; Manabe, Atsufumi; Miyazaki, Takashi

2009-01-01

360

MARINE MINERAL RESOURCES - AN UPDATE AND INTRODUCTION.  

USGS Publications Warehouse

This article briefly traces the status of marine minerals development, and it describes papers presented in this special issue on the subject. Subjects covered include types of deposits, marine mining in Canada, Manganese nodules, metalliferous sulfides as seabed minerals, metallurgical processes for reducing sulfide minerals, U. S. phosphate industry, construction materials and placers, and industry problems.

Cruickshank, Michael J.; Siapno, William

1985-01-01

361

The Lifecycle of a Mineral Deposit: A Teache's Guide for Hands-On Mineral Education Activities  

NSDL National Science Digital Library

This teacher's guide provides an introduction to the process of finding or exploring for a mineral deposit, extracting or mining the resource, recovering it, and reclaiming the mined area (sometimes called 'beneficiation' or 'life cycle'). Topics include what a mineral deposit is; how they are identified and measured, how the minerals are extracted; and how the mining site is reclaimed. There is also discussion of how minerals and mineral resources are processed and how they are used in everyday life. The guide includes ten activities that educate students on basic geologic concepts; the processes of finding, identifying, and extracting the resources from a mineral deposit; and the uses of minerals.

362

25 CFR 225.33 - Assignment of minerals agreements.  

Code of Federal Regulations, 2010 CFR

... 225.33 Section 225.33 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR ENERGY AND MINERALS OIL AND GAS, GEOTHERMAL, AND SOLID MINERALS AGREEMENTS Minerals Agreements § 225.33 Assignment of minerals...

2010-04-01

363

25 CFR 225.22 - Approval of minerals agreements.  

Code of Federal Regulations, 2011 CFR

... 225.22 Section 225.22 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR ENERGY AND MINERALS OIL AND GAS, GEOTHERMAL, AND SOLID MINERALS AGREEMENTS Minerals Agreements § 225.22 Approval of minerals...

2011-04-01

364

25 CFR 225.22 - Approval of minerals agreements.  

... 225.22 Section 225.22 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR ENERGY AND MINERALS OIL AND GAS, GEOTHERMAL, AND SOLID MINERALS AGREEMENTS Minerals Agreements § 225.22 Approval of minerals...

2014-04-01

365

25 CFR 225.22 - Approval of minerals agreements.  

Code of Federal Regulations, 2013 CFR

... 225.22 Section 225.22 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR ENERGY AND MINERALS OIL AND GAS, GEOTHERMAL, AND SOLID MINERALS AGREEMENTS Minerals Agreements § 225.22 Approval of minerals...

2013-04-01

366

25 CFR 225.22 - Approval of minerals agreements.  

Code of Federal Regulations, 2010 CFR

... 225.22 Section 225.22 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR ENERGY AND MINERALS OIL AND GAS, GEOTHERMAL, AND SOLID MINERALS AGREEMENTS Minerals Agreements § 225.22 Approval of minerals...

2010-04-01

367

25 CFR 225.22 - Approval of minerals agreements.  

Code of Federal Regulations, 2012 CFR

... 225.22 Section 225.22 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR ENERGY AND MINERALS OIL AND GAS, GEOTHERMAL, AND SOLID MINERALS AGREEMENTS Minerals Agreements § 225.22 Approval of minerals...

2012-04-01

368

25 CFR 225.33 - Assignment of minerals agreements.  

Code of Federal Regulations, 2013 CFR

... 225.33 Section 225.33 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR ENERGY AND MINERALS OIL AND GAS, GEOTHERMAL, AND SOLID MINERALS AGREEMENTS Minerals Agreements § 225.33 Assignment of minerals...

2013-04-01

369

25 CFR 225.33 - Assignment of minerals agreements.  

... 225.33 Section 225.33 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR ENERGY AND MINERALS OIL AND GAS, GEOTHERMAL, AND SOLID MINERALS AGREEMENTS Minerals Agreements § 225.33 Assignment of minerals...

2014-04-01

370

25 CFR 225.33 - Assignment of minerals agreements.  

Code of Federal Regulations, 2011 CFR

... 225.33 Section 225.33 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR ENERGY AND MINERALS OIL AND GAS, GEOTHERMAL, AND SOLID MINERALS AGREEMENTS Minerals Agreements § 225.33 Assignment of minerals...

2011-04-01

371

25 CFR 225.33 - Assignment of minerals agreements.  

Code of Federal Regulations, 2012 CFR

... 225.33 Section 225.33 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR ENERGY AND MINERALS OIL AND GAS, GEOTHERMAL, AND SOLID MINERALS AGREEMENTS Minerals Agreements § 225.33 Assignment of minerals...

2012-04-01

372

43 CFR 3602.20 - Administration of mineral materials sales.  

Code of Federal Regulations, 2011 CFR

...2011-10-01 2011-10-01 false Administration of mineral materials sales. 3602.20 Section 3602...LAND MANAGEMENT, DEPARTMENT OF THE INTERIOR MINERALS MANAGEMENT (3000) MINERAL MATERIALS DISPOSAL Mineral Materials Sales...

2011-10-01

373

30 CFR 256.80 - Leases of other minerals.  

Code of Federal Regulations, 2010 CFR

30 Mineral Resources 2 2010-07-01 2010-07-01 false Leases of other minerals. 256.80 Section 256.80 Mineral Resources MINERALS MANAGEMENT SERVICE, DEPARTMENT OF THE INTERIOR OFFSHORE LEASING OF SULPHUR OR...

2010-07-01

374

Water in Nominally Anhydrous Minerals from Nakhlites and Shergottites  

NASA Technical Reports Server (NTRS)

Estimating the amount of water in the interior of terrestrial planets has tremendous implications on our understanding of solar nebula evolution, planet formation and geological history, and extraterrestrial volcanism. Mars has been a recent focus of such enquiry with complementary datasets from spacecrafts, rovers and martian meteorite studies. In planetary interiors, water can be dissolved in fluids or melts and hydrous phases, but can also be locked as protons attached to structural oxygen in lattice defects in nominally anhydrous minerals (NAM) such as olivine, pyroxene, or feldspar [1-3]. Measuring water in Martian meteorite NAM is challenging because the minerals are fragile and riddled with fractures from impact processes that makes them break apart during sample processing. Moreover, curing the sample in epoxy causes problems for the two main water analysis techniques, Fourier transform infrared spectrometry (FTIR) and secondary ionization mass spectrometry (SIMS). Measurements to date have resulted in a heated debate on how much water the mantle of Mars contains. SIMS studies of NAM [4], amphiboles [5], and apatites [6-8] from Martian meteorites report finding enough water in these phases to infer that the martian mantle is as hydrous as that of the Earth. On the other hand, a SIMS study of glass in olivine melt inclusions from shergottites concludes that the Martian mantle is much drier [9]. The latter interpretation is also supported by the fact that most martian hydrous minerals generally have the relevant sites filled with Cl and F instead of H [10,11]. As for experimental results, martian basalt compositions can be reproduced using water as well as Cl in the parent melts [12,13]. Here FTIR is used to measure water in martian meteorite minerals in order to constrain the origin of the distribution of water in martian meteorite phases.

Peslier, Anne H.

2013-01-01

375

Mineral-fluid interaction in the lungs: insights from reaction-path modeling.  

PubMed

Thermodynamic modeling, in conjunction with available kinetic information, has been employed to investigate the fate of chrysotile and tremolite in the human lung. In particular, we focus on mineral-fluid reactions using techniques borrowed from geochemistry, including calculation of saturation indices, activity-ratio phase diagrams, and reaction-path modeling. Saturation index calculations show that fresh lung fluid is undersaturated with respect to both tremolite and chrysotile and these minerals should dissolve, in accordance with conclusions from previous work described in the literature. Modeling of reaction paths in both closed and open systems confirms previous suggestions that chrysotile dissolves faster than tremolite in lung fluid, which offers an explanation for the apparent increase in tremolite/chrysotile ratios in lungs of miners and millers over time. However, examination of activity-ratio phase diagrams and reaction-path model calculations raises the possibility not only that minerals dissolve congruently in lung fluid, but that secondary minerals such as talc or various Ca-Mg carbonates might potentially form in lung fluid as asbestiform minerals dissolve. PMID:16920671

Wood, Scott A; Taunton, Anne E; Normand, Charles; Gunter, Mickey E

2006-11-01

376

Carbon Mineralizability Determines Interactive Effects on Mineralization of Pyrogenic Organic Matter and Soil Organic Carbon  

SciTech Connect

Soil organic carbon (SOC) is a critical and active pool in the global C cycle, and the addition of pyrogenic organic matter (PyOM) has been shown to change SOC cycling, increasing or decreasing mineralization rates (often referred to as priming). We adjusted the amount of easily mineralizable C in the soil, through 1-day and 6-month pre-incubations, and in PyOM made from maple wood at 350°C, through extraction. We investigated the impact of these adjustments on C mineralization interactions, excluding pH and nutrient effects and minimizing physical effects. We found short-term increases (+20-30%) in SOC mineralization with PyOM additions in the soil pre-incubated for 6 months. Over the longer term, both the 6-month and 1-day pre-incubated soils experienced net ~10% decreases in SOC mineralization with PyOM additions. This was possibly due to stabilization of SOC on PyOM surfaces, suggested by nanoscale secondary ion mass spectrometry. Additionally, the duration of pre-incubation affected priming interactions, indicating that there may be no optimal pre-incubation time for SOC mineralization studies. We show conclusively that relative mineralizability of SOC in relation to PyOM-24 C is an important determinant of the effect of PyOM additions on SOC mineralization.

Whitman, Thea L.; Zhu, Zihua; Lehmann, Johannes C.

2014-10-31

377

Mineral Sequestration of Carbon Dixoide in a Sandstone-Shale System  

SciTech Connect

A conceptual model of CO2 injection in bedded sandstone-shale sequences has been developed using hydrogeologic properties and mineral compositions commonly encountered in Gulf Coast sediments. Numerical simulations were performed with the reactive fluid flow and geochemical transport code TOUGHREACT to analyze mass transfer between sandstone and shale layers and CO2 immobilization through carbonate precipitation. Results indicate that most CO2 sequestration occurs in the sandstone. The major CO2 trapping minerals are dawsonite and ankerite. The CO2 mineral-trapping capacity after 100,000 years reaches about 90 kg per cubic meter of the medium. The CO2 trapping capacity depends on primary mineral composition. Precipitation of siderite and ankerite requires Fe+2 supplied mainly by chlorite and some by hematite dissolution and reduction. Precipitation of dawsonite requires Na+ provided by oligoclase dissolution. The initial abundance of chlorite and oligoclase therefore affects the CO2 mineral trapping capacity. The sequestration time required depends on the kinetic rate of mineral dissolution and precipitation. Dawsonite reaction kinetics is not well understood, and sensitivity regarding the precipitation rate was examined. The addition of CO2 as secondary carbonates results in decreased porosity. The leaching of chemical constituents from the interior of the shale causes slightly increased porosity. The limited information currently available for the mineralogy of natural high-pressure CO2 gas reservoirs is also generally consistent with our simulation. The ''numerical experiments'' give a detailed understanding of the dynamic evolution of a sandstone-shale geochemical system.

Xu, Tianfu; Apps, John A.; Pruess, Karsten

2004-07-09

378

Corrosion of heavy minerals during weathering and diagenesis: A catalog for optical analysis  

NASA Astrophysics Data System (ADS)

A practical classification of surface textures observed on detrital grains in sands and sandstones is proposed, in order to enhance data reproducibility among operators and to implement the use of high-resolution heavy-mineral data in studies of sediment-generation, provenance, and diagenesis. Five stages of progressive weathering (unweathered, corroded, etched, deeply etched, skeletal) are recognized for diverse detrital minerals. Archetypal grains displaying increasing degrees of corrosion are illustrated in numerous color tables for visual comparison. This catalog, specifically devised to systematically collect valuable information for paleoclimatic or diagenetic interpretation during routine grain-counting under the microscope, is here shown to represent a useful subsidiary tool to reveal the different degrees of weathering for diverse minerals in modern sands of equatorial Africa, and to identify post-depositional modifications of detrital assemblages in buried orogenic sediments of the Bengal Basin. The data thus obtained need to be interpreted by carefully considering the concentration of heavy minerals in each sample, which provides the fundamental clue to quantify the degree of heavy-mineral depletion caused by either pre-depositional or post-depositional processes. The scrutiny of dissolution effects has applications in the study of the chemical properties of minerals and of diagenetic evolution, helping us to understand the development of secondary porosity and to assess the potential of water and hydrocarbon reservoirs.

Andò, Sergio; Garzanti, Eduardo; Padoan, Marta; Limonta, Mara

2012-12-01

379

Evaporites, petroleum and mineral resources  

SciTech Connect

This book illustrates the expanding knowledge of evaporites as important reservoir seals, fluid aquitards, ore-hosting sediments, and economically viable sediments in their own right. Researchers, oil and gas professionals, minerals resource professionals, environmental specialists and others within geology and the other earth sciences shall utilize the information within this book in their understanding of the many recent discoveries and concepts involved in the field of evaporite sedimentology.

Melvin, J.L.

1991-01-01

380

Mineral of the month: garnet  

USGS Publications Warehouse

Garnet is the general name given to a group of complex silicate minerals, all with isometric crystal structure, similar properties and chemical compositions. Garnet occurs in every color of the spectrum except blue, but it is most commonly red, purple, brown and green. Garnet necklaces dating from the Bronze Age have been found in graves and also among the ornaments adorning the oldest Egyptian mummies.

Olson, Donald

2005-01-01

381

Effects of physical and geochemical heterogeneities on mineral transformation and biomass accumulation during biostimulation experiments at Rifle, Colorado  

Microsoft Academic Search

Electron donor amendment for bioremediation often results in precipitation of secondary minerals and the growth of biomass, both of which can potentially change flow paths and the efficacy of bioremediation. Quantitative estimation of precipitate and biomass distribution has remained challenging, partly due to the intrinsic heterogeneities of natural porous media and the scarcity of field data. In this work, we

Li Li; Carl I. Steefel; Michael B. Kowalsky; Andreas Englert; Susan S. Hubbard

2010-01-01

382

Decreased bone area, bone mineral content, formative markers, and increased bone resorptive markers in endogenous Cushing's syndrome  

Microsoft Academic Search

It is well established that chronic excess of glucocorticoids has negative effects on bone and collagen turnover, and that secondary osteoporosis is a known clinical complication of endogenous Cushing's syndrome (CS). The aim of the present study was to evaluate bone dimension and bone mineral content in relation to biochemical markers of bone and collagen turnover, in a consecutive series

Kristin Godang; Thor Ueland; Jens Bollerslev

1999-01-01

383

Mines and Mineral Occurrences of Afghanistan  

NSDL National Science Digital Library

The USGS has recently released the report Mines and Mineral Occurrences of Afghanistan in Adobe Acrobat (.pdf) format. The 95-page open file report is an inventory of more than 1000 mines and mineral occurrences in the country that resources that include metals, industrial minerals, coal, and peat. The data was compiled from published literature and digital files of the members of the National Industrial Minerals project, and are presented in tables that list mineral showings, deposits, and pegmatite fields. This site is also reviewed in the May 3, 2002 Scout Report.

2002-01-01

384

Is Struvite a Prebiotic Mineral?  

PubMed Central

The prebiotic relevance of mineral struvite, MgNH4PO4·6H2O, was studied experimentally as a phosphorylating reagent and, theoretically, to understand the geochemical requirements for its formation. The effectiveness of phosphorylation by the phosphate mineral, monetite, CaHPO4, was also studied to compare to the efficiency of struvite. The experiments focused on the phosphorylation reactions of the minerals with organic compounds, such as nucleosides, glycerol and choline chloride, and heat at 75 °C for about 7–8 days and showed up to 28% phosphorylation of glycerol. In contrast, the compositional requirements for the precipitation of struvite are high ammonium and phosphate concentrations, as well as a little Ca2+ dissolved in the water. Combined, these requirements suggest that it is not likely that struvite was present in excess on the early Earth to carry out phosphorylation reactions. The present study focuses on the thermodynamic aspects of struvite formation, complementing the results given by Orgel and Handschuh (1973), which were based on the kinetic effects. PMID:25369744

Gull, Maheen; Pasek, Matthew A.

2013-01-01

385

Secondary Masters in Machine Learning  

E-print Network

Page 1 Secondary Masters in Machine Learning Student Handbook Revised 8/20/14 #12;Page 2 Table:.......................................................................................8 Machine Learning Journal Club.........................................................................................................11 #12;Page 3 Introduction The field of machine learning is concerned with the question of how

386

Regulation of fungal secondary metabolism.  

PubMed

Fungi produce a multitude of low-molecular-mass compounds known as secondary metabolites, which have roles in a range of cellular processes such as transcription, development and intercellular communication. In addition, many of these compounds now have important applications, for instance, as antibiotics or immunosuppressants. Genome mining efforts indicate that the capability of fungi to produce secondary metabolites has been substantially underestimated because many of the fungal secondary metabolite biosynthesis gene clusters are silent under standard cultivation conditions. In this Review, I describe our current understanding of the regulatory elements that modulate the transcription of genes involved in secondary metabolism. I also discuss how an improved knowledge of these regulatory elements will ultimately lead to a better understanding of the physiological and ecological functions of these important compounds and will pave the way for a novel avenue to drug discovery through targeted activation of silent gene clusters. PMID:23178386

Brakhage, Axel A

2013-01-01

387

Development projects: Secondary school, Arnold   

E-print Network

This BULLETIN describes a secondary school at Arnold, Nottinghamshire, designed by the Development Group of the Architects and Building Branch of the Ministry of Education in collaboration with the Local Education Authority. It was the sixth...

Anonymous

388

40 CFR 133.102 - Secondary treatment.  

... 2013-07-01 true Secondary treatment. 133.102 Section 133.102...ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS SECONDARY TREATMENT REGULATION § 133.102 Secondary treatment. The following paragraphs...

2014-07-01

389

40 CFR 133.102 - Secondary treatment.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 false Secondary treatment. 133.102 Section 133.102...ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS SECONDARY TREATMENT REGULATION § 133.102 Secondary treatment. The following paragraphs...

2013-07-01

390

40 CFR 133.102 - Secondary treatment.  

Code of Federal Regulations, 2012 CFR

...2012-07-01 false Secondary treatment. 133.102 Section 133.102...ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS SECONDARY TREATMENT REGULATION § 133.102 Secondary treatment. The following paragraphs...

2012-07-01

391

Forest type affects the coupled relationships of soil C and N mineralization in the temperate forests of northern China.  

PubMed

Decomposition of soil organic matter (SOM) is sensitive to vegetation and climate change. Here, we investigated the influence of changes in forest types on the mineralization of soil carbon (C) and nitrogen (N), and their temperature sensitivity (Q10) and coupling relationships by using a laboratory soil incubation experiments. We sampled soils from four forest types, namely, a primary Quercus liaotungensis forest (QL), Larix principis-rupprechtii plantation (LP), Pinus tabulaeformis plantation (PT), and secondary shrub forest (SS) in temperate northern China. The results showed that soil C and N mineralization differed significantly among forest types. Soil C and N mineralization were closely coupled in all plots, and C:N ratios of mineralized SOM ranged from 2.54 to 4.12. Forest type significantly influenced the Q10 values of soil C and N mineralization. The activation energy (Ea) of soil C and N mineralization was negatively related to the SOM quality index in all forest types. The reverse relationships suggested that the carbon quality-temperature (CQT) hypothesis was simultaneously applicable to soil C and N mineralization. Our findings show that the coupled relationships of soil C and N mineralization can be affected by vegetation change. PMID:25322802

Quan, Quan; Wang, Changhui; He, Nianpeng; Zhang, Zhen; Wen, Xuefa; Su, Hongxin; Wang, Qing; Xue, Jingyue

2014-01-01

392

Forest type affects the coupled relationships of soil C and N mineralization in the temperate forests of northern China  

PubMed Central

Decomposition of soil organic matter (SOM) is sensitive to vegetation and climate change. Here, we investigated the influence of changes in forest types on the mineralization of soil carbon (C) and nitrogen (N), and their temperature sensitivity (Q10) and coupling relationships by using a laboratory soil incubation experiments. We sampled soils from four forest types, namely, a primary Quercus liaotungensis forest (QL), Larix principis-rupprechtii plantation (LP), Pinus tabulaeformis plantation (PT), and secondary shrub forest (SS) in temperate northern China. The results showed that soil C and N mineralization differed significantly among forest types. Soil C and N mineralization were closely coupled in all plots, and C:N ratios of mineralized SOM ranged from 2.54 to 4.12. Forest type significantly influenced the Q10 values of soil C and N mineralization. The activation energy (Ea) of soil C and N mineralization was negatively related to the SOM quality index in all forest types. The reverse relationships suggested that the carbon quality-temperature (CQT) hypothesis was simultaneously applicable to soil C and N mineralization. Our findings show that the coupled relationships of soil C and N mineralization can be affected by vegetation change. PMID:25322802

Quan, Quan; Wang, Changhui; He, Nianpeng; Zhang, Zhen; Wen, Xuefa; Su, Hongxin; Wang, Qing; Xue, Jingyue

2014-01-01

393

Secondary lip and palate surgery.  

PubMed

To properly treat a patient with a secondary cleft lip or palate deformity, one must make an accurate diagnosis of the underlying problem. Recognition of specific recurring patterns and common deformities will help facilitate the surgical planning process and assist the surgeon during future procedures. Through a combination of accurate analysis, clinical patience, and technical precision, successful correction of secondary cleft lip and palate deformities can be delivered. PMID:24607196

Monson, Laura A; Khechoyan, David Y; Buchanan, Edward P; Hollier, Larry H

2014-04-01

394

Reactive transport modeling of CO2 mineral sequestration in basaltic rocks  

NASA Astrophysics Data System (ADS)

CO2 mineral sequestration in basalt may provide a long lasting, thermodynamically stable, and environmentally benign solution to reduce greenhouse gases in the atmosphere. Multi-dimensional, field scale, reactive transport models of this process have been developed with a focus on the CarbFix pilot CO2 injection in Iceland. An extensive natural analog literature review was conducted in order to identify the primary and secondary minerals associated with water-basalt interaction at low and elevated CO2 conditions. Based on these findings, an internally consistent thermodynamic database describing the mineral reactions of interest was developed and validated. Hydrological properties of field scale mass transport models were properly defined by calibration to field data using iTOUGH2. Reactive chemistry was coupled to the models and TOUGHREACT used for running predictive simulations carried out with the objective of optimizing long-term management of injection sites, to quantify the amount of CO2 that can be mineralized, and to identify secondary minerals that compete with carbonates for cations leached from the primary rock. Calibration of field data from the CarbFix reservoir resulted in a horizontal permeability for lava flows of 300 mD and a vertical permeability of 1700 mD. Active matrix porosity was estimated to be 8.5%. The CarbFix numerical models were a valuable engineering tool for designing optimal injection and production schemes aimed at increasing groundwater flow. Reactive transport simulations confirm dissolution of primary basaltic minerals as well as carbonate formation, and thus indicate in situ CO2 mineral sequestration in basalts to be a viable option. Furthermore, the simulations imply that clay minerals are most likely to compete with magnesite-siderite solid solutions for Mg and Fe leached from primary minerals, whereas zeolites compete with calcite for dissolved Ca. In the case of the CarbFix pilot injection, which involves a continuous injection of 1,100 tons CO2 in total for 6 months, the basalt hosted reservoir was estimated to have a 100% sequestering efficiency after 10 years. In the case of an upscaled 10 year long injection of 40,000 tons per year, sequestering efficiency of the same reservoir was estimated to be about 10% after 100 years. However, sequestering efficiency in the latter case has every potential of increasing substantially with time due to the vast amount of primary basaltic minerals in the reservoir.

Aradottir, E. S.; Sonnenthal, E. L.; Bjornsson, G.; Jonsson, H.

2011-12-01

395

Decorin modulates matrix mineralization in vitro  

NASA Technical Reports Server (NTRS)

Decorin (DCN), a member of small leucine-rich proteoglycans, is known to modulate collagen fibrillogenesis. In order to investigate the potential roles of DCN in collagen matrix mineralization, several stable osteoblastic cell clones expressing higher (sense-DCN, S-DCN) and lower (antisense-DCN, As-DCN) levels of DCN were generated and the mineralized nodules formed by these clones were characterized. In comparison with control cells, the onset of mineralization by S-DCN clones was significantly delayed; whereas it was markedly accelerated and the number of mineralized nodules was significantly increased in As-DCN clones. The timing of mineralization was inversely correlated with the level of DCN synthesis. In these clones, the patterns of cell proliferation and differentiation appeared unaffected. These results suggest that DCN may act as an inhibitor of collagen matrix mineralization, thus modulating the timing of matrix mineralization.

Mochida, Yoshiyuki; Duarte, Wagner R.; Tanzawa, Hideki; Paschalis, Eleftherios P.; Yamauchi, Mitsuo

2003-01-01

396

43 CFR 3602.33 - How will BLM dispose of mineral materials for use in developing Federal mineral leases?  

Code of Federal Regulations, 2011 CFR

...2011-10-01 false How will BLM dispose of mineral materials for use in developing Federal mineral leases? 3602.33 Section 3602.33...LAND MANAGEMENT, DEPARTMENT OF THE INTERIOR MINERALS MANAGEMENT (3000) MINERAL MATERIALS...

2011-10-01

397

The Osteocyte in CKD: New Concepts Regarding the Role of FGF23 in Mineral Metabolism and Systemic COmplications  

PubMed Central

The identification of elevated circulating levels of the osteocytic protein fibroblast growth factor 23 (FGF23) in patients with chronic kidney disease (CKD), along with recent data linking these values to the pathogenesis of secondary hyperparathyroidism and to systemic complications, has changed the approach to the pathophysiology and treatment of disordered bone and mineral metabolism in renal failure. It now appears that osteocyte biology is altered very early in the course of CKD and these changes have implications for bone biology, as well as for progressive cardiovascular and renal disease. Since circulating FGF23 values are influenced by therapies used to treat secondary hyperparathyroidism, the effects of different therapeutic paradigms on FGF23 have important implications for mineral metabolism as well as for morbidity and mortality. Further studies are critically needed to identify the initial trigger for abnormalities of skeletal mineralization and turnover as well as the potential effects that current therapeutic options may have on osteocyte biology. PMID:23079136

Wesseling-Perry, Katherine; Jüppner, Harald

2012-01-01

398

Secondary procedures in thoracic aorta.  

PubMed

Secondary procedures for thoracic aorta are very demanding to the patient, with significantly high perioperative mortality and morbidity. The aim of this paper was to review the most remarkable secondary procedures following open and endorepairs of thoracic aorta. The PubMed database was searched without any year limits. Search terms used %were "thoracic", "aorta" and "reintervention". Two authors independently reviewed abstracts identified by the search and subsequently the reference lists of eligible series were scrutinized in order to detect any additional relevant articles. Different early and late complications following open an endovascular repair of thoracic aorta were described adding their incidence and their potential solutions with secondary interventions. Secondary interventions after open repair (OR) are more related to bleeding and progression of the aortic disease issues and open surgery is again the most common solution. However, in more fragile patients with favorable anatomy, endovascular repair can be offered as a secondary procedure. Reinterventions after endovascular treatment of thoracic aorta diseases (TEVAR) are mostly related to endoleaks and also to the aortic disease progression. Hopefully, the oncoming technological improvements together with the optimized operator expertise can reduce the incidence of secondary procedures following TEVAR for all the aortic pathologies. PMID:25216218

Mestres, G; Capoccia, L; Riambau, V

2014-12-01

399

Mineral Scavenger Hunt 1. CONTRIBUTOR'S NAME: Johnny MacLean  

E-print Network

8) Topaz 7) Quartz 6) Feldspar 5) Apatite 4) Fluorite 3) Calcite 2) Gypsum 1) Talc - Other mineralMineral Scavenger Hunt 1. CONTRIBUTOR'S NAME: Johnny MacLean 2. NAME OF INQUIRY: Mineral Scavenger from minerals? What are some objects in the classroom that come from minerals? What minerals did

Brewer, Carol

400

Treatment of chronic kidney disease-mineral and bone disorder (CKD-MBD).  

PubMed

Disturbances in mineral and bone metabolism play a critical role in the pathogenesis of cardiovascular complications in patients with chronic kidney disease (CKD). The term "renal osteodystrophy" has recently been replaced with "CKD-mineral and bone disorder (CKD-MBD)", which includes vascular calcification as well as bone abnormalities. Following this paradigm shift, the Japanese Society for Dialysis Therapy released guidelines for the management of secondary hyperparathyroidism in chronic dialysis patients, which prioritized improvement in survival, but not in bone abnormalities. According to these guidelines, parathyroid intervention, such as parathyroidectomy and percutaneous ethanol injection therapy, should be indicated if mineral disorders cannot be managed by pharmacological means. Recently, several novel therapeutic tools, including sevelamer hydrochloride, calcitriol analogs, and cinacalcet hydrochloride have been introduced in the clinical setting in Japan. Harmonizing these therapeutic modalities, we should expect more effective management of CKD-MBD, leading to the improvement of morbidity and mortality in this patient population. PMID:18520108

Komaba, Hirotaka; Tanaka, Motoko; Fukagawa, Masafumi

2008-01-01

401

Mineral reactions and controls on zeolite facies alteration in sandstone of central Transantarctic Mountains, Antarctica  

SciTech Connect

Volcanic sandstones of the Fremouw and Falla formations contain abundant zeolite-facies authigenic minerals. Mineral and chemical patterns in Fremouw and Falla sandstone suggest that porosity and authigenic mineralogy were controlled by parent material composition, fluid chemistry, permeability, and temperature. Mineral patterns suggest simple rock-fluid reactions in which unstable volcanic rock fragments and plagioclase grains were altered to clay, heulandite, albite, laumontite, and/or prehnite. Chemical patterns suggest that significant mass transfer of Na+, Ca+2 and Si+4 occurred in the sandstone during alteration, whereas Al+3 mobility was restricted and was incorporated into clay and/or zeolite cements. These cements typically reduced primary porosity to a few percent; however, some secondary porosity was created by the dissolution of detrital plagioclase grains.

Vavra, C.L.

1983-03-01

402

Mineral Resource Information System for Field Lab in the Osage Mineral Reservation Estate  

SciTech Connect

The Osage Mineral Reservation Estate is located in Osage County, Oklahoma. Minerals on the Estate are owned by members of the Osage Tribe who are shareholders in the Estate. The Estate is administered by the Osage Agency, Branch of Minerals, operated by the U.S. Bureau of Indian Affairs (BIA). Oil, natural gas, casinghead gas, and other minerals (sand, gravel, limestone, and dolomite) are exploited by lessors. Operators may obtain from the Branch of Minerals and the Osage Mineral Estate Tribal Council leases to explore and exploit oil, gas, oil and gas, and other minerals on the Estate. Operators pay a royalty on all minerals exploited and sold from the Estate. A mineral Resource Information system was developed for this project to evaluate the remaining hydrocarbon resources located on the Estate. Databases on Microsoft Excel spreadsheets of operators, leases, and production were designed for use in conjunction with an evaluation spreadsheet for estimating the remaining hydrocarbons on the Estate.

Carroll, H.B.; Johnson, William I.

1999-04-27

403

Mechanical regulation of secondary chondrogenesis.  

PubMed

The development of the skull is characterised by its dependence upon epigenetic influences. One of the most important of these is secondary chondrogenesis, which occurs following ossification within certain membrane bone periostea, as a result of biomechanical articulation. We have studied the genesis, character and function of the secondary chondrocytes of the quadratojugal of the chick between embryonic days 11 and 14. Analysis of gene expression revealed that secondary chondrocytes formed coincident with Sox9 upregulation from a precursor population expressing Cbfa1/Runx2: a reversal of the normal sequence. Such secondary chondrocytes rapidly acquired a phenotype that is a compound of prehypertrophic and hypertrophic chondrocytes, exited from the cell cycle and upregulated Ihh. Pulse and pulse/chase experiments with BrdU confirmed the germinal region as the highly proliferative source of the secondary chondrocytes, which formed by division of chondrocyte-committed precursors. By blocking Hh signalling in explant cultures we show that the enhanced proliferation of the germinal region surrounding the secondary chondrocytes derives from this Ihh source. Additionally, in vitro studies on membrane bone periosteal cells (nongerminal region) demonstrated that these cells can also respond to Ihh, and do so both by enhanced proliferation and precocious osteogenesis. Despite the pro-osteogenic effects of Ihh on periosteal cell differentiation, mechanical articulation of the quadratojugal/quadrate joint in explant culture revealed a negative role for articulation in the regulation of osteocalcin by germinal region descendants. Thus, the mechanical stimulus that is the spur to secondary chondrocyte formation appears able to override the osteogenic influence of Ihh on the periosteum, but does not interfere with the cell cycle-promoting component of Hh signalling. PMID:16912408

Archer, Charles W; Buxton, Paul; Hall, Brian K; Francis-West, Philippa

2006-01-01

404

Geomorphic controls on mineral weathering, elemental transport, and production of mineral surface area in a schist bedrock weathering profile, Piedmont Pennsylvania  

NASA Astrophysics Data System (ADS)

We assess a deep chemical weathering profile in the context of geomorphic evolution in the Laurels Schist, a late proterozoic greenschist formation in the Christina River Basin Critical Zone Observatory located in the Piedmont region in southeastern Pennsylvania. Two 21-meter deep rotosonic drill cores were sampled at the ridge top and footslope positions in a first-order, forested watershed. The top meter was sampled at high-resolution in a soil pit adjacent to each drill core and along a hillslope transect to assess geomorphic controls on the weathering profile. Weathering processes in soil and saprolite were examined by observing changes in mineralogy, including the emergence of secondary phyllosilicate and oxide minerals; measuring specific surface area of bulk soil and saprolite; and by quantifying elemental mass changes of major and minor rock-forming elements. Mineral profiles were assessed using clay and bulk XRD, and reveal that kaolinite, a common secondary phyllosilicate, is present above 1.5 meters in the weathering profile. Specific surface area (SSA) values decrease with increasing depth to a critical depth around 2 meters, where the values of untreated (carbon-loaded) and muffled (carbon removed by heating) mineral grains converge to baseline SSA values below 10 m2g-1, indicating that carbon is sorbed with mineral surface area in the upper 2 meters. Immobile element concentrations decrease with increasing depth up to 3 meters, indicating that the preferential removal of mobile elements extends beyond the depth of C-mineral adsorption. Variability of immobile elements in the deep weathering profile reveal variations that could be the result of weathering in fractures but are more likely inherited by the rock composition and particle size of pre-metamorphosed parent rock.

Wenell, B.; Yoo, K.; Aufdenkampe, A. K.; Mahoney, J. B.; Lepak, L.

2013-12-01

405

Brecciated and mineralized coals in Union County Western Kentucky coal field  

USGS Publications Warehouse

Coals from the D-2 and D-3 boreholes in the Grove Center 7 1/2 min quadrangle, Union County, KY, have been found to be highly brecciated and mineralized. The mineralization is dominated by a carbonate assemblage with minor sulfides and sulfates. Included among the secondary minerals is the lead selenide, clausthalite. Overall, the emplacement of secondary vein minerals was responsible for raising the rank of the coals from the 0.6-0.7% Rmax range found in the area to as high as 0.95-0.99% Rmax. A 1.3-m-thick coal found in one of the boreholes is unique among known Western Kentucky coals in having less than 50% vitrinite. Semifusinite and fusinite dominate the maceral assemblages. The coal is also low in sulfur coal, which is unusual for the Illinois Basin. It has an ash yield of less than 10%; much of it dominated by pervasive carbonate veining. The age of the thick coal in core D-2 is similar to that of the Elm Lick coal bed, found elsewhere in the Western Kentucky coalfield. The coals in D-3 are younger, having Stephanian palynomorph assemblages. ?? 2001 Elsevier Science B.V. All rights reserved.

Hower, J.C.; Williams, D.A.; Eble, C.F.; Sakulpitakphon, T.; Moecher, D.P.

2001-01-01

406

Several characteristics of the formation of secondary porosity in Mesozoic sand-siltstones of the western Precaucasus  

SciTech Connect

The lithological characteristics of Mesozoic sand-siltstones of the Western Precaucasus are examined. The zonal nature of the distribution of authigenic minerals and reservoir properties in the sand-silt layers is described, along with the dependence of the zonality on layer thickness. The secondary nature of the pore space in terrigenous rocks and possible means of its formation are determined.

Petrova, R.N.; Dement'eva, O.F.; Kornev, A.G.

1986-11-01

407

Analysis of aquifer mineralization by paleodrainage channels  

NASA Astrophysics Data System (ADS)

Mineralization of groundwater resources is a problem in south-central Kansas, due to the penetration of saline water from Permian bedrock formations into the overlying alluvial aquifer. One of the mechanisms involved in the mineralization involves small bedrock features of high permeability located in places occupied by streams and rivers in past geological eras. These geological features are termed 'paleodrainage channels'. The permeability of the overlying aquifer can be significantly smaller than that of the channel fill material. The comparatively fast migration of saline water through these channels of high permeability is associated with the transfer of minerals into the overlying freshwater aquifer. This study applies a set of boundary layer approaches to quantify the process of mineral transfer from the channels into the aquifer. The methods used in the present study provide quick estimation and evaluation of the dilution of the channel flow, as well as mineral concentration profile changes in the mineralized zone created in the overlying aquifer. More generally, the method can also be useful for the analysis and evaluation of various types of groundwater contamination in heterogeneous aquifers. The application of the method is exemplified by a complete set of calculations characterizing the possible mineralization process at a specific channel in south central Kansas. Sensitivity analyses are performed and provide information about the importance of the various parameters that affect the mineralization process. Some possible scenarios for the aquifer mineralization phenomena are described and evaluated. It is shown that the channel mineralization may create either several stream tubes of the aquifer with high mineral concentration, or many stream tubes mineralized to a lesser extent. Characteristics of these two patterns of aquifer mineralization are quantified and discussed.

Rubin, Hillel; Buddemeier, Robert W.

2003-06-01

408

Analysis of aquifer mineralization by paleodrainage channels  

USGS Publications Warehouse

Mineralization of groundwater resources is a problem in south-central Kansas, due to the penetration of saline water from Permian bedrock formations into the overlying alluvial aquifer. One of the mechanisms involved in the mineralization involves small bedrock features of high permeability located in places occupied by streams and rivers in past geological eras. These geological features are termed 'paleodrainage channels'. The permeability of the overlying aquifer can be significantly smaller than that of the channel fill material. The comparatively fast migration of saline water through these channels of high permeability is associated with the transfer of minerals into the overlying freshwater aquifer. This study applies a set of boundary layer approaches to quantify the process of mineral transfer from the channels into the aquifer. The methods used in the present study provide quick estimation and evaluation of the dilution of the channel flow, as well as mineral concentration profile changes in the mineralized zone created in the overlying aquifer. More generally, the method can also be useful for the analysis and evaluation of various types of groundwater contamination in heterogeneous aquifers. The application of the method is exemplified by a complete set of calculations characterizing the possible mineralization process at a specific channel in south central Kansas. Sensitivity analyses are performed and provide information about the importance of the various parameters that affect the mineralization process. Some possible scenarios for the aquifer mineralization phenomena are described and evaluated. It is shown that the channel mineralization may create either several stream tubes of the aquifer with high mineral concentration, or many stream tubes mineralized to a lesser extent. Characteristics of these two patterns of aquifer mineralization are quantified and discussed. ?? 2003 Published by Elsevier Science B.V.

Rubin, H.; Buddemeier, R.W.

2003-01-01

409

The Minerals of Aureum Chaos  

NASA Technical Reports Server (NTRS)

[figure removed for brevity, see original site] Click on image for animation of 3-dimensional model with 5x vertical exaggeration

This image of chaotic terrain in the Aureum Chaos region of Mars was taken by the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) at 0858UTC (3:58 a.m. EST) on January 24, 2008, near 3.66 degrees south latitude, 26.5 degrees west longitude. The image was taken in 544 colors covering 0.36-3.92 micrometers, and shows features as small as 18 meters (60 feet) across. The image is about 10 kilometers (6.2 miles) wide at its narrowest point.

Aureum Chaos is a 368 kilometer (229 mile) wide area of chaotic terrain in the eastern part of Valles Marineris. The chaotic terrain is thought to have formed by collapse of the surrounding Margaritifer Terra highland region. Aureum Chaos contains heavily eroded, randomly oriented mesas, plateaus, and knobs many revealing distinct layered deposits along their slopes. These deposits may be formed from remnants of the collapsed highlands, sand carried by Martian winds, dust or volcanic ash that settled out of the atmosphere, or sediments laid down on the floor of an ancient lake.

The top panel in the montage above shows the location of the CRISM image on a mosaic taken by the Mars Odyssey spacecraft's Thermal Emission Imaging System (THEMIS). The CRISM data cover a narrow plateau near the edge of the chaotic terrain, that stretches across from the southwest to the northeast.

The lower left image, an infrared false color image, reveals the plateau and several eroded knobs of varying sizes. The plateau's layer-cake structure is similar to that of other layered outcrops in Valles Marineris.

The lower right image reveals the strengths of mineral spectral features overlain on a black-and-white version of the infrared image. Areas shaded in red hold more of the mineral pyroxene, a primary component of basaltic rocks that are prevalent in the highlands. Spots of green indicate monohydrated sulfate minerals (sulfates with one water molecule incorporated into each molecule of the mineral), while blue indicates polyhydrated sulfate minerals (sulfates with multiple waters per mineral molecule).

Although the plateau's dark cap rock is somewhat mineralogically non-descript, the bright, white swath of underlying material cascading down the plateau's flanks appears to hold polyhydrated sulfates. Dark eolian or wind deposited sediments in the south-central part of the plateau are also rich in polyhydrated sulfates.

Surrounding the plateau are small greenish spots of monoyhydrated sulfates. These are erosional remnants of an even lower part of the layered deposits that is compositionally distinct from the main part of the plateau.

The deepest layer visible is preexisting 'basement' rock that forms the floor of Aureum Chaos around the plateau. It is comprised of basaltic rock exposed by collapse of the crust and the debris derived from that collapse.

The animation (see above) of a 3-dimensional topographic model illustrates the relationship of these materials. It was made using the lower right CRISM image, draped over MOLA topography with 5X vertical exaggeration.

CRISM is one of six science instruments on NASA's Mars Reconnaissance Orbiter. Led by The Johns Hopkins University Applied Physics Laboratory, Laurel, Md., the CRISM team includes expertise from universities, government agencies and small businesses in the United States and abroad. NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Mars Reconnaissance Orbiter and the Mars Science Laboratory for NASA's Science Mission Directorate, Washington. Lockheed Martin Space Systems, Denver, built the orbiter.

2008-01-01

410

Evaluating biodiversity of mineral lands  

SciTech Connect

Increasingly, lands intended for mining, or lands that have been mined and reclaimed, are being evaluated in terms of biological diversity (biodiversity). The concept of biodiversity includes die variety and number of living organisms, their organizations, and the environments that support them. This paper presents a framework for discussing and evaluating biodiversity and for constructing checklists for evaluating biodiversity before and after mining. This framework identifies some of the different types of biodiversity applicable to mineral lands, die ranges of scale at which they are applicable, and the social stakes and stakeholders relevant across scale and diversity types.

Wade, G.L. [USDA Forest Service, Burlington, VT (United States); Tritton, L.M.

1997-12-31

411

Mineral/water interactions in tailings from a tungsten mine, Mount Pleasant, New Brunswick  

NASA Astrophysics Data System (ADS)

The pore-water geochemistry and mineralogy of tailings derived from a granitic tungsten deposit were characterized by collecting pore-water samples at discrete depth intervals throughout the tailings for the analysis of major and minor element concentrations. Mineralogical samples from the oxidation zone were analyzed by X-ray diffraction, scanning electron microscopy combined with energy dispersive X-ray spectroscopy (SEM/EDS), electron microprobe (EMP) combined with wavelength dispersive X-ray spectroscopy (WDS), and transmission electron microscopy (TEM). The oxidation of sulfide minerals in the near-surface tailings leads to a decrease in pore-water pH and elevated SO 4, As, and metal concentrations. The unusual mineralogy of this deposit, compared with that of commonly studied base-metal and gold deposits, results in several unique geochemical characteristics. The dissolution of fluorite releases F into the pore water; the F forms strong complexes with Al and enhances the dissolution of aluminosilicate minerals within the oxidation zone. As a result, high Al concentrations (up to 151.7 mg/L) are detected in the near-neutral pore water in the oxidation zone. The combined dissolution of aluminosilicates and carbonate minerals maintains the pH near 10 in the pore water at depth. Elevated concentrations of W (up to 7.1 mg/L) are detected in the pore water throughout the tailings, likely as a result of the dissolution of wolframite. Consistent with geochemical model calculations, results from SEM/EDS, EMP/WDS and TEM/EDS analyses indicate that secondary minerals, which occur as orange-brown coatings on grains of primary-minerals, are Fe oxyhydroxides. Examples of these secondary minerals display a fibrous habit at high resolution in the TEM. One of these minerals, which contains substantial amounts of Al, As, and Si as impurities, was identified by selected-area electron diffraction (SAED) analyses to be goethite. Another mineral contains relatively high amounts of Si, Pb, Bi, and As, and SAED analyses suggest that the mineral is two-line ferrihydrite.

Petrunic, B. M.; Al, T. A.

2005-05-01

412

Regulation of bone mineral loss during lactation  

NASA Technical Reports Server (NTRS)

The effects of varyng dietary calcium and phosphorous levels, vitamin D deficiency, oophorectomy, adrenalectomy, and simultaneous pregnancy on bone mineral loss during lactation in rats are studied. The experimental procedures and evaluations are described. The femur ash weight of lactating and nonlactating rats are calculated. The data reveals that a decrease in dietary calcium of 0.02 percent results in an increased loss of bone mineral, an increase in calcium to 1.4 percent does not lessen bone mineral loss, and bone mineral loss in vitamin D deficient rats is independent of calcium levels. It is observed that changes in dietary phosphorous level, oophorectomy, adrenalectomy, and simultaneous pragnancy do not reduce bone mineral loss during lactation. The analysis of various hormones to determine the mechanism that triggers bone mineral loss during lactation is presented.

Brommage, R.; Deluca, H. F.

1985-01-01

413

Secondary Erythromelalgia - A Case Report -  

PubMed Central

Erythromelalgia is a rare neurovascular pain syndrome characterized by a triad of redness, increased temperature, and burning pain primarily in the extremities. Erythromelalgia can present as a primary or secondary form, and secondary erythromelalgia associated with a myeloproliferative disease such as essential thrombocythemia often responds dramatically to aspirin therapy, as in the present case. Herein, we describe a typical case of a 48-year-old woman with secondary erythromelalgia linked to essential thrombocythemia in the unilateral hand. As this case demonstrates, detecting and visualizing the hyperthermal area through infrared thermography of an erythromelalgic patient can assist in diagnosing the patient, assessing the therapeutic results, and understanding the disease course of erythromelalgia. PMID:23862006

Kang, Byoung Chan; Nam, Da Jeong; Ahn, Eun Kyoung; Yoon, Duck Mi

2013-01-01

414

Fungal secondary metabolism — from biochemistry to genomics  

Microsoft Academic Search

Much of natural product chemistry concerns a group of compounds known as secondary metabolites. These low-molecular-weight metabolites often have potent physiological activities. Digitalis, morphine and quinine are plant secondary metabolites, whereas penicillin, cephalosporin, ergotrate and the statins are equally well known fungal secondary metabolites. Although chemically diverse, all secondary metabolites are produced by a few common biosynthetic pathways, often in

Nancy P. Keller; Geoffrey Turner; Joan W. Bennett

2005-01-01

415

Utilization and stabilization of mineral wastes. Bulletin  

Microsoft Academic Search

This report summarizes laboratory research conducted by the Bureau of Mines and cooperative field studies made with the mineral industry to reduce the environmental impacts of air and water pollution deriving from mineral wastes. Research showed that both dry-press and steam-cured building bricks and ceramic tile could be made from copper-mill tailings and other discarded mineral wastes. Sponge iron was

K. C. Dean; L. J. Froisland; M. B. Shirts

1986-01-01

416

Evolution of uranium and thorium minerals  

Microsoft Academic Search

The origins and near-surface distributions of the approximately 250 known uranium and\\/or thorium minerals elucidate principles of mineral evolution. This history can be divided into four phases. The first, from ~4.5 to 3.5 Ga, involved successive concentrations of uranium and thorium from their initial uniform trace distribution into magmatic-related fluids from which the first U4+ and Th4+ minerals, uraninite (UO2),

R. M. Hazen; R. C. Ewing; D. A. Sverjensky

2009-01-01

417

Mineral Classification - What's in a Name?  

NSDL National Science Digital Library

Students think about the nature of classification systems and about properties that are most useful for classifying minerals as they derive their own hierarchical scheme, or key, for identifying and naming mineral species. When finished, they read Mineralogy: A Historical Review by Robert M. Hazen and revise their classification scheme. Finally, groups trade their systematic plans and identify unknown mineral samples with them, comenting on the usefullness of the various methods.

Perkins, Dexter; Mogk, Dave

418

Mineral oil material in canned foods.  

PubMed

Mineral oil material was determined in canned foods by on-line LC-LC-GC-FID. In the edible oil phase of 90 samples of sea foods, concentrations were mostly around 100 mg/kg, but reached 820 mg/kg. The predominant source of this mineral oil material was lubricating oil used for can manufacturing. Mineral oil contamination of the fish was usually a minor source, but cannot be neglected. PMID:9059586

Grob, K; Huber, M; Boderius, U; Bronz, M

1997-01-01

419

Mineral Distributions at the Developing Tendon Enthesis  

PubMed Central

Tendon attaches to bone across a functionally graded interface, “the enthesis”. A gradient of mineral content is believed to play an important role for dissipation of stress concentrations at mature fibrocartilaginous interfaces. Surgical repair of injured tendon to bone often fails, suggesting that the enthesis does not regenerate in a healing setting. Understanding the development and the micro/nano-meter structure of this unique interface may provide novel insights for the improvement of repair strategies. This study monitored the development of transitional tissue at the murine supraspinatus tendon enthesis, which begins postnatally and is completed by postnatal day 28. The micrometer-scale distribution of mineral across the developing enthesis was studied by X-ray micro-computed tomography and Raman microprobe spectroscopy. Analyzed regions were identified and further studied by histomorphometry. The nanometer-scale distribution of mineral and collagen fibrils at the developing interface was studied using transmission electron microscopy (TEM). A zone (?20 µm) exhibiting a gradient in mineral relative to collagen was detected at the leading edge of the hard-soft tissue interface as early as postnatal day 7. Nanocharacterization by TEM suggested that this mineral gradient arose from intrinsic surface roughness on the scale of tens of nanometers at the mineralized front. Microcomputed tomography measurements indicated increases in bone mineral density with time. Raman spectroscopy measurements revealed that the mineral-to-collagen ratio on the mineralized side of the interface was constant throughout postnatal development. An increase in the carbonate concentration of the apatite mineral phase over time suggested possible matrix remodeling during postnatal development. Comparison of Raman-based observations of localized mineral content with histomorphological features indicated that development of the graded mineralized interface is linked to endochondral bone formation near the tendon insertion. These conserved and time-varying aspects of interface composition may have important implications for the growth and mechanical stability of the tendon-to-bone attachment throughout development. PMID:23152788

Schwartz, Andrea G.; Pasteris, Jill D.; Genin, Guy M.; Daulton, Tyrone L.; Thomopoulos, Stavros

2012-01-01

420

Patch testing with mineral wool (Rockwool).  

PubMed

25% of 315 tested subjects exhibited skin reactions when patch tested with mineral wool. Coating of the mineral fibres with phenol-formaldehyde did not influence the skin reactions. The reactions seem to be induced mechanically, as the mineral without the fibres did not give any reactions. No allergic reactions to the chemical additives were demonstrated. Macroscopically, the reactions may simulate an allergic response; microscopically, they seem to be toxic, sometimes with prominent spongiosis. PMID:71833

Björnberg, A; Löwhagen, G B

1977-01-01

421

California Institute of Technology: Mineral Spectroscopy Server  

NSDL National Science Digital Library

The California Institute of Technology created this website to provide valuable information about the color in minerals and data on mineral absorption spectra and Raman spectra. The modest site features additional information on silica polymorphs, desert varnish, ametrine, and manganese dendrite. Students can discover the technology used to collect the spectra data including the diode-array spectrometer. Researchers can find an updated, lengthy list of references of papers dealing with mineral optical spectroscopy.

422

Testing the Hardness of Common Minerals  

NSDL National Science Digital Library

This activity gives students practice and a chance to develop expertise in using the test for hardness in identifying common minerals. Following a discussion and an introduction to Moh's scale, the students will work in groups to test minerals whose identities are known against their standards (common substances whose hardnesses are known). Once the known minerals have been tested, the students can proceed to test unknown samples. A student worksheet and discussion questions are provided.

2005-10-06

423

Elastic Properties of Clay Minerals  

NASA Astrophysics Data System (ADS)

We present ultrasonic P- and S-waves velocity measurements on pure clay samples using three different experiment setups. These experiments provided petrophysical and acoustic properties of clay minerals as a function both of mineralogy and compaction. In the first experiment, acoustic measurements were performed on cold-pressed clay aggregates at ambient and at hydrostatic pressure conditions. Porosity and grain density values of the different clay mineralogy aggregates ranged from 4 to 43% and 2.13 to 2.83 g cm-3, respectively. In the second experiment, we measured P-wave velocity and attenuation in a kaolinite-water suspension in which clay concentration was increased up to 60%. In the third experiment, P- and S- wave velocities were measured during uniaxial stress compaction of clay powders. Results from all three experiments revealed low bulk (K) and shear (? ) moduli for kaolinite, montmorillonite, and smectite; the values range between 6-12 GPa for K and 4-6 GPa for ? , respectively. Using these clay moduli values in effective medium and granular porous media models, velocity is predicted in saturated pure kaolinite samples, kaolinite suspension and shaly sandstones fairly well. Experimental results also showed that water interlayers play an important role in the compaction and strength of clay aggregates. Clay minerals carrying on water interlayers in their structure showed high compaction and strength. This study is relevant for a more reliable assessment of the seismic response in reservoirs and/or basins characterized by clay-bearing formations.

Vanorio, T.; Prasad, M.; Nur, A.

2001-12-01

424

Minerals, fibrosis, and the lung.  

PubMed Central

Determinants of pulmonary fibrosis induced by inhaled mineral dusts include quantity retained, particle size, and surface area, together with their physical form and the reactive surface groups presented to alveolar cells. The outstanding problem is to ascertain how these factors exert their deleterious effects. Both compact and fibrous minerals inflict membrane damage, for which chemical mechanisms still leave uncertainty. A major weakness of cytotoxicity studies, even when lipid peroxidation and reactive oxygen species are considered, lies in tacitly assuming that membrane damage suffices to account for fibrogenesis, whereas the parallel occurrence of such manifestations does not necessarily imply causation. The two-phase procedure established that particles, both compact and fibrous, induce release of a macrophage factor that provokes fibroblasts into collagen synthesis. The amino acid composition of the macrophage fibrogenic factor was characterized and its intracellular action explained. Fibrous particles introduce complexities respecting type, durability, and dimensions. Asbestotic fibrosis is believed to depend on long fibers, but scrutiny of the evidence from experimental and human sources reveals that a role for short fibers needs to be entertained. Using the two-phase system, short fibers proved fibrogenic. Other mechanisms, agonistic and antagonistic, may participate. Growth factors may affect the fibroblast population and collagen production, with cytokines such as interleukin-1 and tumor necrosis factor exerting control. Immune involvement is best regarded as an epiphenomenon. Downregulation of fibrogenesis may follow collagenase release from macrophages and fibroblasts, while augmented type II cell secretion of lipid can interfere with the macrophage-particle reaction. PMID:1954926

Heppleston, A G

1991-01-01

425

Russia: Secondary Education and Training. Secondary Education Series.  

ERIC Educational Resources Information Center

The World Bank has been assisting the efforts of developing countries to reform secondary education systems for more than 35 years. During this period, the context and imperatives for education reform have changed considerably due to various factors such as globalization of the world economy and the impact of new technologies. This paper is one of…

Fretwell, David H.; Wheeler, Antony

426

Hungary: Secondary Education and Training. Secondary Education Series.  

ERIC Educational Resources Information Center

The World Bank has been assisting the efforts of developing countries to reform secondary education systems for more than 35 years. During this period, the context and imperatives for education reform have changed considerably due to various factors such as globalization of the world economy and the impact of new technologies. This paper is one of…

Fretwell, David H.; Wheeler, Antony

427

Romania: Secondary Education and Training. Secondary Education Series.  

ERIC Educational Resources Information Center

The World Bank has been assisting the efforts of developing countries to reform secondary education systems for more than 35 years. During this period, the context and imperatives for education reform have changed considerably due to various factors such as globalization of the world economy and the impact of new technologies. This paper is one of…

Fretwell, David H.; Wheeler, Antony

428

Poland: Secondary Education and Training. Secondary Education Series.  

ERIC Educational Resources Information Center

The World Bank has been assisting the efforts of developing countries to reform secondary education systems for more than 35 years. During this period, the context and imperatives for education reform have changed considerably due to various factors such as globalization of the world economy and the impact of new technologies. This paper is one of…

Fretwell, David H.; Wheeler, Antony

429

Turkey: Secondary Education and Training. Secondary Education Series.  

ERIC Educational Resources Information Center

The World Bank has been assisting the efforts of developing countries to reform secondary education systems for more than 35 years. During this period, the context and imperatives for education reform have changed considerably due to various factors such as globalization of the world economy and the impact of new technologies. This paper is one of…

Fretwell, David H.; Wheeler, Antony

430

Secondary Education in Malta: Guide to Secondary Education in Europe.  

ERIC Educational Resources Information Center

The Maltese islands consist of Malta, Gozo, and Comino and two tiny uninhabited islands, strategically located in the middle of the Mediterranean Sea. This handbook contains a brief description of secondary education in Malta. Following the introduction, section 1 provides an overview of the mission of the Ministry of Education and Human…

Attard, Paul A.; Buhagiar, Andrew J.

431

A Novel Approach to Mineral Carbonation: Enhancing Carbonation While Avoiding Mineral Pretreatment Process Cost  

SciTech Connect

Known fossil fuel reserves, especially coal, can support global energy demands for centuries to come, if the environmental problems associated with CO{sub 2} emissions can be overcome. Unlike other CO{sub 2} sequestration candidate technologies that propose long-term storage, mineral sequestration provides permanent disposal by forming geologically stable mineral carbonates. Carbonation of the widely occurring mineral olivine (e.g., forsterite, Mg{sub 2}SiO{sub 4}) is a large-scale sequestration process candidate for regional implementation, which converts CO{sub 2} into the environmentally benign mineral magnesite (MgCO{sub 3}). The primary goal is cost-competitive process development. As the process is exothermic, it inherently offers low-cost potential. Enhancing carbonation reactivity is key to economic viability. Recent studies at the U.S. DOE Albany Research Center have established that aqueous-solution carbonation using supercritical CO{sub 2} is a promising process; even without olivine activation, 30-50% carbonation has been achieved in an hour. Mechanical activation (e.g., attrition) has accelerated the carbonation process to an industrial timescale (i.e., near completion in less than an hour), at reduced pressure and temperature. However, the activation cost is too high to be economical and lower cost pretreatment options are needed. We have discovered that robust silica-rich passivating layers form on the olivine surface during carbonation. As carbonation proceeds, these passivating layers thicken, fracture and eventually exfoliate, exposing fresh olivine surfaces during rapidly-stirred/circulating carbonation. We are exploring the mechanisms that govern carbonation reactivity and the impact that (1) modeling/controlling the slurry fluid-flow conditions, (2) varying the aqueous ion species/size and concentration (e.g., Li+, Na+, K+, Rb+, Cl-, HCO{sub 3}{sup -}), and (3) incorporating select sonication offer to enhance exfoliation and carbonation. Thus far, we have succeeded in nearly doubling the extent of carbonation observed compared with the optimum procedure previously developed by the Albany Research Center. Aqueous carbonation reactivity was found to be a strong function of the ionic species present and their aqueous activities, as well as the slurry fluid flow conditions incorporated. High concentration sodium, potassium, and sodium/potassium bicarbonate aqueous solutions have been found to be the most effective solutions for enhancing aqueous olivine carbonation to date. Slurry-flow modeling using Fluent indicates that the slurry-flow dynamics are a strong function of particle size and mass, suggesting that controlling these parameters may offer substantial potential to enhance carbonation. During the first project year we developed a new sonication exfoliation apparatus with a novel sealing system to carry out the sonication studies. We also initiated investigations to explore the potential that sonication may offer to enhance carbonation reactivity. During the second project year, we extended our investigations of the effects of sonication on the extent of carbonation as a function of the following parameters: particle size distribution, the mass of solid reactant, volume fraction of aqueous solution present, sonication power, time, temperature, and CO{sub 2} pressure. To date, none of the conditions investigated have significantly enhanced carbonation. Mechanistic investigations of the stirred ({approx}1,500 rpm) aqueous olivine carbonation process indicate the carbonation process involves both incongruent magnesium dissolution and silica precipitation, which results in robust silica-rich passivating layer formation. Secondary ion mass spectrometry observation of H within the passivating layer that forms during static carbonation suggests 2H{sup +}/Mg{sup 2+} ion exchange is associated with incongruent dissolution. Apparently, H{sub 2}O forms at or near the olivine/passivating-layer interface during the process and diffuses out through the passivating layers during the carbonation reaction. This is

Andrew V. G. Chizmeshya; Michael J. McKelvy; Kyle Squires; Ray W. Carpenter; Hamdallah Bearat

2007-06-21

432

REACTIVITY OF PRIMARY SOIL MINERALS AND SECONDARY PRECIPITATES BENEATH LEAKING HANFORD WASTE TANKS  

EPA Science Inventory

Since the late 1950s, leaks from 67 single-shell tanks at the Hanford Site have been detected or suspected, resulting in the release of about 1 million curies to the underlying sediments. The Hanford Tri-Party Agreement calls for the initiation of remediation at the 200 Area tan...

433

PROGRESS REPORT. REACTIVITY OF PRIMARY SOIL MINERALS AND SECONDARY PRECIPITATES BENEATH LEAKING HANFORD WASTE TANKS  

EPA Science Inventory

Since the late 1950s, leaks from 67 single-shell tanks at the Hanford Site have released about 1 million curies to the underlying sediments. At issue is the distribution of contaminants beneath the tanks, and the processes that led to their current disposition and will control th...

434

Dissolution of minerals and hydrometallurgical processes  

NASA Astrophysics Data System (ADS)

Physical, chemical, electrochemical, and electrolytic processes involved in the dissolution of minerals in aqueous solutions are identified and characterized. Their importance to hydrometallurgy is outlined.

Habashi, Fathi

1983-08-01

435

Canadian Micro-Mineral Association: ALKALI - NUTS  

NSDL National Science Digital Library

This website, created by the Canadian Micro-Mineral Association, furnishes information on the minerals and environments near Mont Saint-Hilaire (MSH) in Quebec, Canada. Students and educators can discover the physical characteristics, fluorescence, and the distribution and rarity of the hundreds of species of minerals found around MSH. Each description includes helpful images of the amazing minerals and environments. Users can learn about the two classification systems: Dana and Strunz. The site presents MSH-related current news, articles, and announcements. Users can also discover the meaning and origin of the term, ALKALI-NUTS.

436

Multiphase Sequestration Geochemistry: Model for Mineral Carbonation  

SciTech Connect

Carbonation of formation minerals converts low viscosity supercritical CO2 injected into deep saline reservoirs for geologic sequestration into an immobile form. Until recently the scientific focus of mineralization reactions with reservoir rocks has been those that follow an aqueous-mediated dissolution/precipitation mechanism, driven by the sharp reduction in pH that occurs with CO2 partitioning into the aqueous phase. For sedimentary basin formations the kinetics of aqueous-mediated dissolution/precipitation reactions are sufficiently slow to make the role of mineralization trapping insignificant over a century period. For basaltic saline formations aqueous-phase mineralization progresses at a substantially higher rate, making the role of mineralization trapping significant, if not dominant, over a century period. The overlooked mineralization reactions for both sedimentary and basaltic saline formations, however, are those that occur in liquid or supercritical CO2 phase; where, dissolved water appears to play a catalyst role in the formation of carbonate minerals. A model is proposed in this paper that describes mineral carbonation over sequestration reservoir conditions ranging from dissolved CO2 in aqueous brine to dissolved water in supercritical CO2. The model theory is based on a review of recent experiments directed at understanding the role of water in mineral carbonation reactions of interest in geologic sequestration systems occurring under low water contents.

White, Mark D.; McGrail, B. Peter; Schaef, Herbert T.; Hu, Jian Z.; Hoyt, David W.; Felmy, Andrew R.; Rosso, Kevin M.; Wurstner, Signe K.

2011-04-01

437

Mineralization of breccia pipes in northern Arizona.  

USGS Publications Warehouse

Hundreds of breccia pipes, some mineralized with ore-grade Cu and/or U, occur in the Colorado Plateau of N Arizona. The pipes originated in the Mississippian Redwall limestone, on its solution-collapse, and stoped through the overlying strata to the Triassic Chinle formation. Mineralization occurred during the Mesozoic, first with Mississippi Valley-type Cu-Pb-Zn deposits, and later with uraninite. The origin of the mineralizing fluids is unknown. Prospecting criteria and the complete systematics of these pipes and their mineralizations require further research.-G.J.N.

Wenrich, K.J.

1985-01-01

438

Mineral-Based Amendments for Remediation  

PubMed Central

Amending soils with mineral-based materials to immobilize contaminants is both old and new. Although mineral amendments have been used for decades in agriculture, new applications with a variety of natural and reprocessed materials are emerging. By sequestering contaminants in or on solid phases and reducing their ability to partition into water or air, amendments can reduce the risk of exposure to humans or biota. A variety of mineral types are commonly used to amend contaminated soils, with different modes of molecular-scale sequestration. Regulatory, social, and economic factors also influence decisions to employ mineral amendments as a treatment technology. PMID:22203887

O’Day, Peggy A.; Vlassopoulos, Dimitri

2011-01-01

439

Citrate bridges between mineral platelets in bone  

PubMed Central

We provide evidence that citrate anions bridge between mineral platelets in bone and hypothesize that their presence acts to maintain separate platelets with disordered regions between them rather than gradual transformations into larger, more ordered blocks of mineral. To assess this hypothesis, we take as a model for a citrate bridging between layers of calcium phosphate mineral a double salt octacalcium phosphate citrate (OCP-citrate). We use a combination of multinuclear solid-state NMR spectroscopy, powder X-ray diffraction, and first principles electronic structure calculations to propose a quantitative structure for this material, in which citrate anions reside in a hydrated layer, bridging between apatitic layers. To assess the relevance of such a structure in native bone mineral, we present for the first time, to our knowledge, 17O NMR data on bone and compare them with 17O NMR data for OCP-citrate and other calcium phosphate minerals relevant to bone. The proposed structural model that we deduce from this work for bone mineral is a layered structure with thin apatitic platelets sandwiched between OCP-citrate–like hydrated layers. Such a structure can explain a number of known structural features of bone mineral: the thin, plate-like morphology of mature bone mineral crystals, the presence of significant quantities of strongly bound water molecules, and the relatively high concentration of hydrogen phosphate as well as the maintenance of a disordered region between mineral platelets. PMID:24706850

Davies, Erika; Müller, Karin H.; Wong, Wai Ching; Pickard, Chris J.; Reid, David G.; Skepper, Jeremy N.; Duer, Melinda J.

2014-01-01

440

Minerals Yearbook, 1988. The mineral industries of the Arabian Peninsula and Persian Gulf countries. International review  

SciTech Connect

The document contains commodity reviews (metals, mineral fuels, industrial minerals where applicable) for the following countries: Bahrain, Iran, Iraq, Kuwait, Oman, Qatar, Saudi Arabia, United Arab Emirates, People's Democratic Republic of Yeman, and Yeman Arab Republic.

Michalski, B.; Antonides, L.E.; Morgan, G.A.

1988-01-01

441

20 CFR 725.202 - Miner defined; condition of entitlement, miner.  

Code of Federal Regulations, 2011 CFR

...Persons Entitled to Benefits, Conditions, and Duration of Entitlement Conditions and Duration of Entitlement...725.202 Miner defined; condition of entitlement, miner...presumption that any person working in or around a coal...

2011-04-01

442

The nanosphere iron mineral(s) in Mars soil  

NASA Technical Reports Server (NTRS)

A series of surface-modified clays containing nanophase (np) iron/oxyhydroxides of extremely small particle sizes, with total iron contents as high as found in Mars soil, were prepared by iron deposition on the clay surface from ferrous chloride solution. Comprehensive studies of the iron mineralogy in these 'Mars-soil analogs' were conducted using chemical extractions, solubility analyses, pH and redox, x ray and electron diffractometry, electron microscopic imaging specific surface area and particle size determinations, differential thermal analyses, magnetic properties characterization, spectral reflectance, and Viking biology simulation experiments. The clay matrix and the procedure used for synthesis produced nanophase iron oxides containing a certain proportion of divalent iron, which slowly converts to more stable, fully oxidized iron minerals. The noncrystalline nature of the iron compounds precipitated on the surface of the clay was verified by their complete extractability in oxalate. Lepidocrocite (gamma-FeOOH) was detected by selected area electron diffraction. It is formed from a double iron Fe(II)/Fe(III) hydroxyl mineral such as 'green rust', or ferrosic hydroxide. Magnetic measurements suggested that lepidocrocite converted to the more stable meaghemite (gamma-Fe203) by mild heat treatment and then to nanophase hematite (aplha-Fe203) by extensive heat treatment. Their chemical reactivity offers a plausible mechanism for the somewhat puzzling observations of the Viking biology experiments. Their unique chemical reactivities are attributed to the combined catalytic effects of the iron oxide/oxyhydroxide and silicate phase surfaces. The mode of formation of these (nanophase) iron oxides on Mars is still unknown.

Banin, A.; Ben-Shlomo, T.; Margulies, L.; Blake, D. F.; Mancinelli, R. L.; Gehring, A. U.

1993-01-01

443

The nanosphere iron mineral(s) in Mars soil  

NASA Astrophysics Data System (ADS)

A series of surface-modified clays containing nanophase (np) iron/oxyhydroxides of extremely small particle sizes, with total iron contents as high as found in Mars soil, were prepared by iron deposition on the clay surface from ferrous chloride solution. Comprehensive studies of the iron mineralogy in these 'Mars-soil analogs' were conducted using chemical extractions, solubility analyses, pH and redox, x ray and electron diffractometry, electron microscopic imaging specific surface area and particle size determinations, differential thermal analyses, magnetic properties characterization, spectral reflectance, and Viking biology simulation experiments. The clay matrix and the procedure used for synthesis produced nanophase iron oxides containing a certain proportion of divalent iron, which slowly converts to more stable, fully oxidized iron minerals. The noncrystalline nature of the iron compounds precipitated on the surface of the clay was verified by their complete extractability in oxalate. Lepidocrocite (gamma-FeOOH) was detected by selected area electron diffraction. It is formed from a double iron Fe(II)/Fe(III) hydroxyl mineral such as 'green rust', or ferrosic hydroxide. Magnetic measurements suggested that lepidocrocite converted to the more stable meaghemite (gamma-Fe203) by mild heat treatment and then to nanophase hematite (aplha-Fe203) by extensive heat treatment. Their chemical reactivity offers a plausible mechanism for the somewhat puzzling observations of the Viking biology experiments. Their unique chemical reactivities are attributed to the combined catalytic effects of the iron oxide/oxyhydroxide and silicate phase surfaces. The mode of formation of these (nanophase) iron oxides on Mars is still unknown.

Banin, A.; Ben-Shlomo, T.; Margulies, L.; Blake, D. F.; Mancinelli, R. L.; Gehring, A. U.

1993-11-01

444

Manganese mineral interactions in brain.  

PubMed

Manganese (Mn) is an essential mineral but is toxic when taken in excess. However, whether its interactions with other minerals in organs and cells are involved in mechanisms underlying Mn toxicity is poorly understood. We designed a developmental rat model of chronic Mn treatment (Group A: 1 mg MnCl2.4H2O per ml of drinking water; Group B: 10 mg MnCl2.4H2O per ml of drinking water; Group C: 20 mg MnCl2.4H2O per ml of drinking water; Control Group given water without manganese addition). Employing the model and instrumental neutron activation analysis, we investigated two hypotheses: (i) chronic manganese treatment alters the brain regional distribution of manganese and this altered manganese distribution also leads to region-specific changes of other metals; (ii) chronic manganese treatment induces differential changes in subcellular distributions of metals and electrolytes. In the treated rats, brain Mn level showed dose-related increases, the most pronounced being noted in striatum, hypothalamus, and hippocampus: these increases also led to alterations in regional distribution pattern of Mn. In the treated rats, Fe level was increased in hypothalamus, cerebellum, hippocampus, pons and medulla, and striatum. Cu level was increased in pons and medulla, hippocampus, midbrain, and striatum. Se level was increased in cerebellum, striatum, midbrain, hypothalamus, and pons and medulla. Zn level was increased in hypothalamus and striatum. Ca level was increased in midbrain but decreased in cerebellum; however, Mg and Al levels were not markedly affected. In brains of Mn-treated rats, Mn levels in subcellular fractions were all increased, being especially marked in nuclei, mitochondria, and synaptosomes; the subcellular distributions of Fe, Cu, Zn, and Mg were differentially altered although those of Al and Ca were minimally affected. These results are consistent with our hypotheses and may have implications in manganese neurotoxicity. The cellular and molecular mechanisms underlying manganese-mineral interactions in brain are still poorly defined and merit further investigation. PMID:10385902

Lai, J C; Minski, M J; Chan, A W; Leung, T K; Lim, L

1999-01-01

445

Pathobiology of secondary immune thrombocytopenia  

PubMed Central

Primary immune thrombocytopenic purpura (ITP) remains a diagnosis of exclusion both from nonimmune causes of thrombocytopenia and immune thrombocytopenia that develops in the context of other disorders (secondary immune thrombocytopenia). The pathobiology, natural history, and response to therapy of the diverse causes of secondary ITP differ from each other and from primary ITP, so accurate diagnosis is essential. Immune thrombocytopenia can be secondary to medications or to a concurrent disease, such as an autoimmune condition (eg, systemic lupus erythematosus [SLE], antiphospholipid antibody syndrome [APS], immune thyroid disease, or Evans syndrome), a lymphoproliferative disease (eg, chronic lymphocytic leukemia or large granular T-lymphocyte lymphocytic leukemia), or chronic infection, eg, with Helicobacter pylori, human immunodeficiency virus (HIV), or hepatitis C virus (HCV). Response to infection may generate antibodies that cross-react with platelet antigens (HIV, H pylori) or immune complexes that bind to platelet Fc? receptors (HCV) and platelet production may be impaired by infection of megakaryocyte bone marrow-dependent progenitor cells (HCV and HIV), decreased production of thrombopoietin (TPO), and splenic sequestration of platelets secondary to portal hypertension (HCV). Sudden and severe onset of thrombocytopenia has been observed in children after vaccination for measles, mumps, and rubella or natural viral infections, including Epstein-Barr virus, cytomegalovirus, and varicella zoster virus. This thrombocytopenia may be caused by cross-reacting antibodies and closely mimics acute ITP of childhood. Proper diagnosis and treatment of the underlying disorder, where necessary, play an important role in patient management. PMID:19245930

Cines, Douglas B.; Liebman, Howard; Stasi, Roberto

2009-01-01

446

SCIENCE IN THE SECONDARY SCHOOL.  

ERIC Educational Resources Information Center

SELECTED RESEARCH STUDIES PUBLISHED DURING 1959-1963 RELATED TO SECONDARY SCIENCE EDUCATION WERE SURVEYED, CLASSIFIED, AND BRIEFLY ANALYZED. THE CATEGORIES USED TO CLASSIFY THE 103 STUDIES INCLUDED--(1) CURRICULUM STUDIES, (2) CURRICULUM EVALUATION, (3) LEARNING, ABILITY, AND ACHIEVEMENT, (4) METHODS AND ORGANIZATION FOR TEACHING, (5) INSTRUCTION…

HURD, PAUL DE HART; ROWE, MARY BUDD

447

Analysis of piston secondary motion  

NASA Astrophysics Data System (ADS)

A nonlinear model of the piston with reciprocating, lateral and rotational degree of freedom is developed to investigate the piston secondary motion and the induced vibration behavior of the engine block by the piston slap. The model parameters are obtained from mobility measurement. The gap between the piston skirt and the cylinder liner is modeled as a translational hard stop which is the nonlinear component in the model. The value of the friction coefficient between the piston ring and the cylinder liner is determined by correlating the experimental data with the friction force equation. During the piston slap on the cylinder liner, the high damping coefficient and stiffness of the translational hard stop are added to the equation for the piston secondary motion. The model is validated by experimental data obtained from three laser displacement sensors which capture the distinct modes of the piston secondary motion directly from the piston assembly under motorized conditions. The predicted trend of the piston secondary motion and the vibration response of cylinder block are appropriate and compare well with the measured results.

Tan, Yeow-Chong; Ripin, Zaidi Mohd

2013-09-01

448

6, 33373379, 2006 Marine secondary  

E-print Network

applied the UFO- TDMA (ultrafine organic tandem differential mobility analyzer) method to study the pos-5.e. a lower mass concentration of chlorophyll a of the ocean) in October 2002. The overall results of the UFO compounds. Thus, the UFO-TDMA results suggest that the secondary organic compounds may, in addition to being

Boyer, Edmond

449

Portugal's Secondary School Modernisation Programme  

ERIC Educational Resources Information Center

The aim of the Secondary School Modernisation Programme, being implemented in Portugal by "Parque Escolar, EPE", is based on the pursuit of quality and makes Portuguese education a potential international benchmark. This paper discusses the strategies adopted to reorganise school spaces. It describes the conceptual model and highlights the…

Heitor, Teresa V.; Freire da Silva, Jose M. R.

2009-01-01