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1

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

2

Mars weathering analogs - Secondary mineralization in Antarctic basalts  

NASA Technical Reports Server (NTRS)

Alkalic basalt samples from Ross Island, Antarctica, are evaluated as terrestrial analogs to weathered surface materials on Mars. Secondary alteration in the rocks is limited to pneumatolytic oxidation of igneous minerals and glass, rare groundmass clay and zeolite mineralization, and hydrothermal minerals coating fractures and vesicle surfaces. Hydrothermal mineral assemblages consist mainly of K-feldspar, zeolites (phillipsite and chabazite), calcite, and anhydrite. Low alteration rates are attributed to cold and dry environmental factors common to both Antarctica and Mars. It is noted that mechanical weathering (aeolian abrasion) of Martian equivalents to present Antarctic basalts would yield minor hydrothermal minerals and local surface fines composed of primary igneous minerals and glass but would produce few hydrous products, such as palagonite, clay or micas. It is thought that leaching of hydrothermal vein minerals by migrating fluids and redeposition in duricrust deposits may represent an alternate process for incorporating secondary minerals of volcanic origin into Martian surface fines.

Berkley, J. L.

1982-01-01

3

Bisphosphonates do not alter the rate of secondary mineralization  

SciTech Connect

Bisphosphonates function to reduce bone turnover, which consequently increases the mean degree of tissue mineralization at an organ level. However, it is not clear if bisphosphonates alter the length of time required for an individual bone-modeling unit (BMU) to fully mineralize. We have recently demonstrated that it takes {approx}350 days (d) for normal, untreated cortical bone to fully mineralize. The aim of this study was to determine the rate at which newly formed trabecular BMUs become fully mineralized in rabbits treated for up to 414 d with clinical doses of either risedronate (RIS) or alendronate (ALN). Thirty-six, 4-month old virgin female New Zealand white rabbits were allocated to RIS (n = 12; 2.4 {micro}g/kg body weight), ALN (n = 12; 2.4 {micro}g/kg body weight), or volume-matched saline controls (CON; n = 12). Fluorochrome labels were administered at specific time intervals to quantify the rate and level of mineralization of trabecular bone from the femoral neck (FN) by Fourier transform infrared microspectroscopy (FTIRM). The organic (collagen) and inorganic (phosphate and carbonate) IR spectral characteristics of trabecular bone from undecalcified 4 micron thick tissue sections were quantified from fluorescently labels regions that had mineralized for 1, 8, 18, 35, 70, 105, 140, 210, 280, and 385 d (4 rabbits per time point and treatment group). All groups exhibited a rapid increase in mineralization over the first 18 days, the period of primary mineralization, with no significant differences between treatments. Mineralization continued to increase, at a slower rate up, to 385 days (secondary mineralization), and was not different among treatments. There were no significant differences between treatments for the rate of mineralization within an individual BMU; however, ALN and RIS both increased global tissue mineralization as demonstrated by areal bone mineral density from DXA. We conclude that increases in tissue mineralization that occur following a period of bisphosphonate treatment is a function of the suppressed rate of remodeling that allows for a greater number of BMUs to obtain a greater degree of mineralization.

Fuchs R. K.; Miller L.; Faillace M.E.; Allen M.R.; Phipps R.J. and Burr D.B.

2011-05-18

4

An automated method to analyze separately the microtextures of primary {alpha}{sub p} grains and the secondary {alpha}{sub s} inherited colonies in bimodal titanium alloys  

SciTech Connect

A method was developed to automatically recognize the orientations of primary {alpha}{sub p} grains and secondary {alpha}{sub s} colonies of a bimodal titanium alloy, on the orientation map. Both populations of grains are dissociated by correlating the Electron Back Scattering Diffraction data with the corresponding Back Scattered Electron image on which a high chemical contrast is observed between the {alpha}{sub p} and ({alpha}{sub s}+{beta}{sub residual}) phases. The whole data processing is successfully applied to a large EBSD map of a bimodal IMI 834 billet. This allows to discuss the contribution of {alpha}{sub p} grains and {alpha}{sub s} colonies to the sharp texture heterogeneities observed in the billet.

Germain, L. [Laboratoire d'Etude des Textures et Applications aux Materiaux, LETAM, CNRS UMR 7078, Universite de Metz, F-57045 Metz Cedex 01 (France)]. E-mail: germain@letam.univ-metz.fr; Gey, N. [Laboratoire d'Etude des Textures et Applications aux Materiaux, LETAM, CNRS UMR 7078, Universite de Metz, F-57045 Metz Cedex 01 (France); Humbert, M. [Laboratoire d'Etude des Textures et Applications aux Materiaux, LETAM, CNRS UMR 7078, Universite de Metz, F-57045 Metz Cedex 01 (France); Hazotte, A. [Laboratoire d'Etude des Textures et Applications aux Materiaux, LETAM, CNRS UMR 7078, Universite de Metz, F-57045 Metz Cedex 01 (France); Bocher, P. [Centre des technologies de fabrication en aerospatiale, Institut de recherche aerospatiale, CNRC, Montreal, Quebec, H3T 2B2 (Canada); Jahazi, M. [Mc Gill University, Montreal, PQ (Canada)

2005-03-15

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

Friction characteristics of microtextured surfaces under mixed and hydrodynamic lubrication  

E-print Network

perfor- mance of mechanical parts [2,3]. Microtextures act as micro- hydrodynamic bearings, enhancingFriction characteristics of microtextured surfaces under mixed and hydrodynamic lubrication Ashwin Keywords: Surface engineering Microtexturing Hydrodynamic lubrication Mixed lubrication a b s t r a c t We

King, William P.

7

Hydrothermal Alteration in the Logatchev Hydrothermal Field: Implications From Secondary Mineral Assemblages and Mineral Chemistry  

NASA Astrophysics Data System (ADS)

We present new data on secondary mineral assemblages, clay and whole rock chemistry and clay mineral strontium and lithium isotopic compositions of altered rocks and sediments from the active, ultramafic-hosted Logatchev hydrothermal field reflecting various alteration conditions (e.g. fluid mixing, water-rock interaction). The altered ultramafic rocks are mainly consist of lizardite, chrysotile whereas magnetite and pyrite are minor minerals. Chlorite, chlorite-smectite mixed-layer (e.g., corrensite), smectite and talc are additional common phases in the clay fraction of most of these samples.Iron-hydroxides and iron sulfides are the main components of the hydrothermal crusts, with some amounts of pyroxene, chlorite, illite and pyrite. The hydrothermal sediments beneath the crusts are characterized by quartz, smectite and chlorite as main minerals. Analyses of clay separates representing a variety of alteration styles demonstrates that significant and characteristic changes in the bulk rock chemical composition are associated with various alteration conditions. The elements Cr, Cu, Pb and U appears to have a general enrichment in the lizardite and chlorite concentrates in comparison to a depleted mantle. 87Sr/86Sr ratios of clay concentrates vary between 0.7083 and 0.7096 suggesting that the clays either formed as a result of seawater alteration or hydrothermal alteration with various portions of seawater. The strontium isotopic ratio of a chlorite sample from hydrothermal sediments beneath the hydrothermal crust is much lower than the isotopic data reported for the lizardites suggesting precipitation from fluid with lower seawater content. The Li isotopic composition (?7Li) of the clay separates varies between -5.4 and +6.4‰. Thus, the clays are enriched in 6Li relative to both seawater (~31‰) and hydrothermal vent fluids from the Logatchev field (~6‰) suggesting that 6Li is preferentially retained in alteration products. When considered together with the Sr isotope data, these Li isotope data may be used to estimate the temperature of formation of the clay concentrates.

Lackschewitz, K. S.; Augustin, N.; Devey, C. W.; Eisenhauer, A.; Garbe-Schoenberg, D.; James, R.

2005-12-01

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

The Chronology of Asteroid Accretion, Differentiation, and Secondary Mineralization  

NASA Technical Reports Server (NTRS)

We evaluate initial (Al-26/Al-27)(sub I), (Mn-53/Mn-55)(sub I), (Hf-182/Hf-180)(sub I), and Pb-207/Pb-206 ages for igneous differentiated meteorites and chondrules from ordinary chondrites for consistency with radioactive decay of the parent nuclides within a common, closed isotopic system, i.e., the early solar nebula. We find that the relative abundances of Al-26, Mn-53, and Hf-182, here denoted by I(Al)(sub CAI, I(Mn)(sub CAI) and I(Hf)(sub CAI), are consistent with decay from common initial values for the bulk solar system. I(Mn)(sub CAI) and I(Hf)(sub CAI) = 9.1+/-1.7 x 10(exp -6) and 1.06+/-0.09 x 10(exp -6) respectively, correspond to the canonical value of I(Al)(sub CAI) = 5.1 x 10(exp -5). I(Hf)(sub CAI) thus determined is consistent with I(Hf)(sub CAI) = 1.003+/-0.045 x 10(exp -6) directly determined in separate work. I(Mn)(sub CAI) is within error of the lowest value directly determined for CAI. We suggest that erratically higher values directly determined for CAI in carbonaceous chondrites reflect proton irradiation of unaccreted CAIs by the early Sun after other asteroids destined for melting by Al-26 decay had already accreted. The Mn-53 incorporated within such asteroids would have been shielded from further "local" spallogenic contributions. The relative abundances of the short-lived nuclides are less consistent with the Pb-207/Pb-206 ages of the corresponding materials with the best consistency being obtained between (Hf-182/Hf-180)(sub I) and Pb-207/Pb-206 ages of angrites. (Hf-182/Hf-180)(sub I) decreases with decreasing Pb-207/Pb-206 ages at the rate expected from the 8.90+/-0.09 Ma half-life of Hf-182. However, the model "CAI age" thus determined, T(sub CAI,Mn-W) = 4568.6+/-0.7 Ma, is older than the commonly accepted directly measured value T(sub CAI) = 4567.l+/-0.2 Ma. I(Al)(sub I), and (Mn-53/Mn-55)(sub I) are less consistent with Pb-207/Pb-206 ages, but determine T(sub CAI, Mn-Cr) = 4568.3+/-0.5 Ma relative to I(AI)(sub CAI)= 5.1 x 10(exp -5) and a Pb-207/Pb-206 age of 4558.6 Ma for the LEW86010 angrite. However. the (Mn-53/Mn-55)(sub I) and Pb-207/Pb-206 ages of "intermediate" age D'Orbigny-clan angrites and Asuka 881394 are inconsistent with radioactive decay from CAI values with a Mn-55 half-life of 3.7+/-0.4 Ma. in spite of consistency between (Mn-53/Mn-55)(sub I) and (Al-26/Al-27)(sub I). Nevertheless, it appears that the Mn-Cr method with I(Mn)(sub CAI) = 9.1+/-1.7 x 10(exp -6) can be used to date primary igneous events and also secondary mineralization on asteroid parent bodies. We summarize ages thus determined for igneous events on differentiated asteroids and for carbonate and fayalite formation on carbonaceous asteroids.

Nyquist, L. E.; Kleine, T.; Shih, C.-Y.; Reese, Y. D.

2008-01-01

10

Effects of the secondary minerals of the natural pozzolans on their pozzolanic activity  

SciTech Connect

Natural pozzolans have been widely used as substitutes for Portland cement, because of their binding properties. Some of them are natural volcanic rocks which contain secondary minerals such as clays and zeolites corresponding to products of the alteration of the rock. The objective of this study was to document the potential effect of the secondary minerals on the strength development of pozzolanic mortars. We chose to investigate this effect by thermally destabilising these minerals in three different pozzolanic deposits (poz-1, poz-2 and poz-3). We first did a detailed mineralogical study, to identify the occurrence and the nature of the different secondary minerals. Kaolinite is abundant in poz-1 and different types of zeolite were identified in poz-2 and poz-3. Thermal treatments were monitored by X-ray Diffraction (XRD) analysis, in order to document mineralogical transformations. The effect on the pozzolanic activity has been tested by strength measurements on normalised mortars at 1, 7 and 28 days. Strength of all blended cements is enhanced while destabilising secondary alteration minerals. For kaolinite, we showed that a strength improvement occurs as soon as it is destructured, even if it is not transformed in metakaolin. For zeolites, destabilisation takes place at low temperature (350 deg. C), but as recrystallisation products are easily formed, activation temperature window is narrow. Endly, we have evidence that the presence of calcite in pozzolans has an effect on early strength. Therefore this study is giving new perspectives for a better use of natural pozzolanic materials in the cement industry.

Habert, G. [LMTG, CNRS/Universite Paul Sabatier, Observatoire Midi-Pyrenees, 14 Av. E. Belin, 31400 Toulouse (France); Universite Paris-Est, Laboratoire Central des Ponts et Chaussees, 58 Bd Lefebvre, 75732 Paris (France)], E-mail: guillaume.habert@lcpc.fr; Choupay, N. [Lafarge Centre de Recherche, 95 rue de Montmurier, BP 15, 38291 St Quentin Fallavier cedex (France); Montel, J.M.; Guillaume, D. [LMTG, CNRS/Universite Paul Sabatier, Observatoire Midi-Pyrenees, 14 Av. E. Belin, 31400 Toulouse (France); Escadeillas, G. [LMDC, INSA/Universite Paul Sabatier, 135 Avenue de Rangueuil, 31077 Toulouse Cedex 04 (France)

2008-07-15

11

Vertebral fractures and bone mineral density in idiopathic, secondary and corticosteroid associated osteoporosis in men  

Microsoft Academic Search

OBJECTIVETo investigate bone mineral density (BMD) in men with symptomatic osteoporosis and compare BMD in patients with idiopathic, secondary and corticosteroid associated osteoporosis.METHODSAge, number of vertebral fractures at presentation and BMD were investigated in men presenting to a bone metabolism clinic with idiopathic (n=105; group 1), secondary (n=67; group 2) and corticosteroid osteoporosis (n=48; group 3). BMD was measured in

S F Evans; M W J Davie

2000-01-01

12

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

13

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

14

Secondary Minerals in Martian Meteorite MIL 03346 as Detected by Raman Imaging Spectroscopy  

NASA Astrophysics Data System (ADS)

We report a preliminary study of MIL 03346,168 thin section by using the Raman imaging spectroscopy. Our goal is to get the spatial relationship of secondary hydrated minerals in this meteorite and to seek evidences that may hint their origins.

Ling, Z. C.; Wang, A.

2014-06-01

15

The Paris CM chondrite: Secondary minerals and asteroidal processing  

NASA Astrophysics Data System (ADS)

We report a petrographic and mineralogical survey of Paris, a new CM chondrite considered to be the least-altered CM identified so far (Hewins et al.). Compared to other CMs, Paris exhibits (1) a higher concentration of Fe-Ni metal beads, with nickel contents in the range 4.1-8.1 wt%; (2) the systematic presence of thin lamellae and tiny blebs of pentlandite in pyrrhotite grains; and (3) ubiquitous tochilinite/cronstedtite associations with higher FeO/SiO2 and S/SiO2 ratios. In addition, Paris shows the highest concentration of trapped 36Ar reported so far for a CM chondrite (Hewins et al.). In combination with the findings of previous studies, our data confirm the reliability of (1) the alteration sequence based on the chemical composition of tochilinite/cronstedtite associations to quantify the fluid alteration processes and (2) the use of Cr content variability in type II ferroan chondrule olivine as a proxy of thermal metamorphism. In contrast, the scales based on (1) the Fe3+ content of serpentine in the matrix to estimate the degree of aqueous alteration and (2) the chemical composition of Fe-Ni metal beads for quantifying the intensity of the thermal metamorphism are not supported by the characteristics of Paris. It also appears that the amount of trapped 36Ar is a sensitive indicator of the secondary alteration modifications experienced by chondrites, for both aqueous alteration and thermal metamorphism. Considering Paris, our data suggest that this chondrite should be classified as type 2.7 as it suffered limited but significant fluid alteration and only mild thermal metamorphism. These results point out that two separated scales should be used to quantify the degree of the respective role of aqueous alteration and thermal metamorphism in establishing the characteristics of CM chondrites.

Marrocchi, Yves; Gounelle, Matthieu; Blanchard, Ingrid; Caste, Florent; Kearsley, Anton T.

2014-07-01

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

Minerals  

MedlinePLUS

Minerals are important for your body to stay healthy. Your body uses minerals for many different jobs, including building bones, making ... regulating your heartbeat. There are two kinds of minerals: macrominerals and trace minerals. Macrominerals are minerals your ...

18

Unit-cell intergrowth of pyrochlore and hexagonal tungsten bronze structures in secondary tungsten minerals  

NASA Astrophysics Data System (ADS)

Structural relations between secondary tungsten minerals with general composition A x[(W,Fe)(O,OH) 3] ·yH 2O are described. Phyllotungstite ( A=predominantly Ca) is hexagonal, a=7.31(3) Å, c=19.55(1) Å, space group P6 3/ mmc. Pittongite, a new secondary tungsten mineral from a wolframite deposit near Pittong in Victoria, southeastern Australia ( A=predominantly Na) is hexagonal, a=7.286(1) Å, c=50.49(1) Å, space group P-6 m2. The structures of both minerals can be described as unit-cell scale intergrowths of (111) py pyrochlore slabs with pairs of hexagonal tungsten bronze (HTB) layers. In phyllotungstite, the (111) py blocks have the same thickness, 6 Å, whereas pittongite contains pyrochlore blocks of two different thicknesses, 6 and 12 Å. The structures can alternatively be described in terms of chemical twinning of the pyrochlore structure on (111) py oxygen planes. At the chemical twin planes, pairs of HTB layers are corner connected as in hexagonal WO 3.

Grey, Ian E.; Birch, William D.; Bougerol, Catherine; Mills, Stuart J.

2006-12-01

19

Variation of lithium isotope geochemistry during basalt weathering and secondary mineral transformations in Hawaii  

NASA Astrophysics Data System (ADS)

Lithium isotopes are a potential tracer of silicate weathering but the relationship between lithium isotope compositions and weathering state still need to be established with precision. Here, we report Li concentrations and Li isotope compositions of soils developed along a 4 million year humid-environment chronosequence in the Hawaiian Islands. Li concentrations are variable with depth and age, ranging from 0.24 to 21.3 ppm, and significant Li depletions (up to 92%) relative to parent basalts are systematically enhanced towards the surface. Our calculations show that the relative contribution from atmospheric deposits to the Li soil budget remains small, with a maximum contribution from dust Li of 20% at the oldest site. This is explained by the capacity of the weathering products to retain, within the profiles, the Li coming from basalt alteration, and allows us to explore more specifically the role of alteration processes on soil Li isotope signatures. The ?7Li values display a large range between -2.5‰ and +13.9‰. The youngest soils (0.3 ka) display the same ?7Li value as fresh basalt, regardless of depth, despite ?30% Li loss by leaching, indicating that there is little Li isotope fractionation during the incipient stage of weathering. ?7Li values for the older soils (?20 ka) vary non-linearly as a function of time and can be explained by progressive mineral transformations starting with the synthesis of metastable short-range order (nano-crystalline) minerals and followed by their transformation into relatively inert secondary minerals. Results highlight significant Li isotope fractionation during secondary mineral formation and in particular during Li uptake by kaolinite. Finally, we suggest that the non-monotonous evolution of the regolith ?7Li value over the last 4 Ma is consistent with climatic variations, where congruent release of Li isotopes occurs during warmer periods.

Ryu, Jong-Sik; Vigier, Nathalie; Lee, Sin-Woo; Lee, Kwang-Sik; Chadwick, Oliver A.

2014-11-01

20

Secondary mineral evidence of large-scale water table fluctuations at Yucca Mountain, Nye County, Nevada  

SciTech Connect

At Yucca Mountain, currently under consideration as a potential permanent underground repository for high-level radioactive wastes, the present-day water table is 500 to 700 m deep. This thick unsaturated zone (UZ) is part of the natural barrier system and is regarded as a positive attribute of the potential site. The USGS has studied the stable isotopes and petrography of secondary calcite and silica minerals that coat open spaces in the UZ and form irregular veins and masses in the saturated zone (SZ). This paper reviews the findings from the several studies undertaken at Yucca Mountain on its mineralogy.

Whelan, J.F.; Moscati, R.J.; Marshall, B.D [Geological Survey, Denver, CO (United States). Yucca Mountain Project Branch; Roedder, E. [Harvard Univ., Cambridge, MA (United States)

1997-12-01

21

Control of mineral scale deposition in cooling systems using secondary-treated municipal wastewater.  

PubMed

Secondary-treated municipal wastewater (MWW) is a promising alternative to freshwater as power plant cooling system makeup water, especially in arid regions. A prominent challenge for the successful use of MWW for cooling is potentially severe mineral deposition (scaling) on pipe surfaces. In this study, theoretical, laboratory, and field work was conducted to evaluate the mineral deposition potential of MWW and its deposition control strategies under conditions relevant to power plant cooling systems. Polymaleic acid (PMA) was found to effectively reduce scale formation when the makeup water was concentrated four times in a recirculating cooling system. It was the most effective deposition inhibitor of those studied when applied at 10 mg/L dosing level in a synthetic MWW. However, the deposition inhibition by PMA was compromised by free chlorine added for biogrowth control. Ammonia present in the wastewater suppressed the reaction of the free chlorine with PMA through the formation of chloramines. Monochloramine, an alternative to free chlorine, was found to be less reactive with PMA than free chlorine. In pilot tests, scaling control was more challenging due to the occurrence of biofouling even with effective control of suspended bacteria. Phosphorous-based corrosion inhibitors are not appropriate due to their significant loss through precipitation reactions with calcium. Chemical equilibrium modeling helped with interpretation of mineral precipitation behavior but must be used with caution for recirculating cooling systems, especially with use of MWW, where kinetic limitations and complex water chemistries often prevail. PMID:20851443

Li, Heng; Hsieh, Ming-Kai; Chien, Shih-Hsiang; Monnell, Jason D; Dzombak, David A; Vidic, Radisav D

2011-01-01

22

Alteration of bentonite by hyperalkaline fluids: A review of the role of secondary minerals  

NASA Astrophysics Data System (ADS)

Data concerning potential solid products of the interaction of cement pore fluids with bentonite have been reviewed with respect to accurate prediction of bentonite alteration in the long-term. Calcium (aluminium) silicate hydrates (C(A)SH), zeolites, feldspars, hydroxides, carbonates, polymorphs of silica, and some sheet silicates (all of varying degrees of crystallinity) are potential products of cement-bentonite interaction. Evidence from natural systems and laboratory studies suggests that most, or all of these phases, may precipitate on timescales of interest to safety assessment of the geological disposal of radioactive wastes. These data indicate that growth kinetics of secondary minerals is equally as important as thermodynamic stability in controlling occurrence. C(A)SH show variable Ca/Si ratio and Al contents. At high pH (>11), the growth of C(A)SH minerals provides a means by which OH - ions from cement pore fluids may be titrated. Although thermodynamic data exist for a number of naturally-occurring crystalline C(A)SH minerals, they are of doubtful quality and should be applied with caution in predictive modelling. Zeolites are likely to form at lower pH than for C(A)SH, with the Si/Al ratio of the zeolite decreasing with increasing pH of the fluid. Zeolite stability is also strongly dependent upon silica activity in the fluid phase. Although silica activity in bentonite pore fluids will be spatially (and temporally) variable as hyperalkaline alteration proceeds, it is likely that minerals which could form would be those stable in quartz-saturated or supersaturated fluids. Currently available thermodynamic data for zeolites tend to overestimate their stability, leading to inaccurate predictions of their occurrence. Notwithstanding this uncertainty, it is considered that the following secondary minerals are the most likely to form in low temperature cement-bentonite systems: calcite, dolomite, chalcedony, C(A)SH of variable Ca/Si ratio, K-feldspar, illite, phillipsite, analcime, clinoptilolite, and heulandite. The relatively more siliceous zeolites (clinoptilolite, phillipsite) are likely to form at lower pH (distal regions of migrating cement pore fluids), whereas C(A)SH, illite, feldspars, and the more aluminous zeolites (analcime, heulandite) are more likely to form at higher pH and hence, the more proximal regions of migrating cement pore fluids. Predominantly Na-, K-bearing solids will be transformed to those dominated by Ca as the composition of cement pore fluids evolves with time.

Savage, David; Walker, Colin; Arthur, Randy; Rochelle, Chris; Oda, Chie; Takase, Hiro

23

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

24

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

25

Secondary Mineralization of Components in CV3 Chondrites: Nebular and Asteroidal Models  

NASA Astrophysics Data System (ADS)

Our review of mineralogical variations among CV3 chondrites suggests that all components, chondrules, matrices, and CAIs, were affected by various degrees of secondary mineralization. Chondrules and CAIs are rimmed with fayalitic olivine [1, 2]; metal in all components is oxidized and sulfidized to magnetite, Ni-rich metal and sulfides [3]; silicates in all components are aqueously altered to phyllosilicates [4]; and nepheline, sodalite, wollastonite, and hedenbergite replace primary minerals in CAIs [5]. In those CV3s with altered CAIs, nepheline etc. are also present in chondrule mesostases [6] and in matrices [7]. Correlated occurrences of secondary minerals indicate that they have related origins. CV3 chondrites can be divided into three kinds according to their secondary features. Reduced CV3s (e.g., Efremovka) lack magnetite [8] and show minimal secondary features. Oxidized CV3s [8] generally show all features: those like Mokoia contain minor fayalitic rims, nepheline, etc, whereas those like Allende lack phyllosilicates but contain well developed fayalite rims and abundant nepheline, etc. Allende-like CV3 chondrites also contain abundant plate-like matrix olivine (Fa(sub)45-55). Similarities in chemistry and O isotopic composition and petrographic observations suggest that fayalitic rims and plate-like matrix olivine have related origins [1, 9]. The presence of secondary minerals in all components implies that alteration postdated component formation. The absence of secondary minerals in reduced CV3s indicates that CV3 oxidized formed from CV3 reduced-like material. Oxidized and reduced materials coexist in some breccias indicating a common parent asteroid. Nebular origins are widely accepted for most secondary features. To form fayalitic rims and matrix , Palme and colleagues [10, 11] suggest that chondritic components were briefly exposed to a hot (>1500 K), highly oxidizing nebula with H2O/H2 to about 1. Such an environment could have resulted from vaporization after >1000-fold dust/gas enrichment [11]. Fe-rich olivine will not condense until most Mg has condensed into forsterite [11]. The steep compositional gradients between adjacent fayalite and forsterite limit the duration of fayalite condensation to a period of several hours [2]. There are several inconsistencies in this late-stage evaporation-condensation model. Fayalitic rims occur inside chondrules and formed by alteration, not by condensation. Forsterite and enstatite grains that supposedly condensed from the nebula are absent on chondrule rims and in chondrites. Magnetite, Ni-rich metal and sulfides are present inside matrix olivine, inconsistent with equilibrium calculations. I-Xe data suggest that sodalite formation in Allende lasted for about 10 Myr, which is inconsistent with a nebular origin [12]. Asteroidal alteration is favored for magnetite [3] and required for most phyllosilicates [4]. Asteroidal formation of fayalite [13] was rejected [2], partly because hydrous minerals are absent in Allende. We suggest that Allende-like CV3 chondrites may have formed in an asteroid by aqueous alteration and dehydration; see Krot et al. [this volume] for details. Higher Na and K concentrations in oxidized CV3 chondrites are not inconsistent with asteroidal alteration, as CM2 chondrites show similar heterogeneities. Acknowledgments: This work was supported by NASA grants NAGW-3281 (K. Keil) and 152-11-40-23 (M.E.Z.). References: [1] Peck J. A. and Wood J. A. (1987) GCA, 51, 1503-1510. [2] Hua X. et al. (1988) GCA, 52, 1389-1408. [3] Blum J. D. et al. (1989) GCA, 53, 543-556. [4] Keller L. P. et al. (1994) GCA, 58, 5589-5598. [5] Hashimoto A. and Grosman L. (1987) GCA, 51, 1685-1704. [6] Kimura M. and Ikeda Y. (1992) Proc. Symp. Antarc. Meteorites, 17, 31-33. [7] Peck J. A. (1983) LPS XIV, 373-374. [8] McSween H. Y. (1977) GCA, 41, 1777-1790. [9] Weinbruch S. et al. (1993) GCA, 57, 2649-2661. [10] Palme et al. (1991) Meteoritics, 25, 383. [11] Palme H. and Fegley B. (1991) EPSL, 101, 180-195. [12] Swindle T. D. et al. (1988) GCA, 52, 2215-2227. [13]

Scott, E. R. D.; Krot, A. N.; Zolensky, M. E.

1995-09-01

26

Minerals  

NSDL National Science Digital Library

This interactive lesson on minerals starts with a definition of minerals and compares crystalline and amorphous minerals. The composition is discussed and a chart shows the relative amounts of elements in minerals. Next, there is a discussion of the characteristics by which minerals are identified including luster, color, streak, hardness, and cleavage and fracture along with special properties such as magnetism. The characteristics of calcite, talc, hematite, magnetite, and galena are then observed.

27

Geochemical fixation of rare earth elements into secondary minerals in sandstones beneath a natural fission reactor at Bangombé, Gabon  

NASA Astrophysics Data System (ADS)

To study geochemical processes for migration and fixation of fissiogenic rare earth elements (REE) in association with uranium dissolution, in situ isotopic analyses using an ion microprobe were performed on U- and REE-bearing secondary minerals, such as coffinite, françoisite, uraniferous goethite, and uraninite found in a sandstone layer 30 to 110 cm beneath a natural fission reactor at Bangombé, Gabon. Phosphate minerals such as phosphatian coffinite and françoisite with depleted 235U ( 235U/ 238U = 0.00609 to 0.00638) contained large amount of fissiogenic light REE, while micro-sized uraninite grains in a solid bitumen aggregate have normal U isotopic values ( 235U/ 238U = 0.00725) and small amount of fissiogenic REE components. The proportions of fissiogenic and non-fissiogenic REE components in four samples from the core of BAX03 vary in depth ranging from 30 cm to 130 cm beneath the reactor, which suggests mixing between fissiogenic isotopes from the reactor and non-fissiogenic isotopes from original minerals in the sandstone. Significant chemical fractionation was observed between Ce and the other REE in the secondary minerals, which shows evidence of an oxidizing atmosphere during their formation. Pb-isotopic analyses of individual minerals do not directly provide chronological information because of the disturbance of U-Pb decay system due to recent geologic alteration. However, systematic Pb-isotopic results from all of the minerals reveal the mobilization of fissiogenic isotopes, Pb and U from the reactor in association with dolerite dyke intrusion ˜0.798 Ga ago and the formation of the secondary minerals by mixing event between 2.05 Ga-old original minerals and reactor materials due to recent alteration.

Hidaka, Hiroshi; Janeczek, Janusz; Skomurski, Frances N.; Ewing, Rodney C.; Gauthier-Lafaye, François

2005-02-01

28

Minerals  

NSDL National Science Digital Library

This page is from James Madison University's Department of Geology and Environmental Science. It provides an introduction to minerals, an alphabetical list of minerals and dichotomous keys to identifying minerals in PDF. There are also links to other department pages on igneous, sedimentary, and metamorphic rocks.

Fichter, Lynn S.

2000-09-13

29

Minerals  

NSDL National Science Digital Library

This slide show provides students with basic information on mineralogy. It explains how the term "mineral" is defined, the properties that are used to identify minerals, their importance in daily life, and some general facts. For each identifying property, an example mineral and photograph are provided. Addresses to websites with additional information are also included.

Passow, Michael

30

Minerals  

NSDL National Science Digital Library

Create a poster about minerals! Directions: Make a poster about minerals. (20 points) Include at least (1) large picture (15 points) on your poster complete with labels of every part (10 points). (15 points) Include at least three (3) facts about minerals. (5 points each) (15 points) Write at ...

Walls, Mrs.

2011-01-30

31

Microtextural controls of weathering of perthitic alkali feldspars  

NASA Astrophysics Data System (ADS)

The relationship between the microtexture and dissolution behaviour of fresh, HF acid-etched and naturally weathered alkali feldspar phenocrysts from the Lower Devonian Shap granite has been investigated by SEM and TEM. A novel resin impregnation technique has revealed the three dimensional shape and interconnectivity of etch pits beneath the weathered crystal surface. Further electron microscope work suggests that Shap phenocrysts are representative of the alkali feldspar in the protolith of many soils. Fresh and unweathered Shap feldspars have a complex microtexture, comprising areas of pristine cryptoperthite and lamellar microperthite cross-cut by volumes of microporous altered feldspar or "patch perthites." Cryptoperthites are made up of <75 nm wide albite exsolution lamellae (platelets) in tweed orthoclase, whereas lamellar microperthites contain >75 nm wide albite films. The platelets are coherent, but albite films have numerous edge dislocations along their interface with orthoclase; (001) and (010) cleavage surfaces intersect ˜2-3 edge dislocations/?m 2. In three dimensions, these edge dislocations form an orthogonal net in the "Murchison plane" of easy fracture, close to (601). Patch perthites are irregular, semicoherent to incoherent intergrowths of albite and irregular microcline subgrains, with ˜0.65-0.70 sub-?m to ?m-sized pores/?m 2. Microporous patch perthites form by dissolution-reprecipitation reactions with magmatic or hydrothermal fluids and pores are present before the alkali feldspars enter the weathering regime. Dissolution of Shap feldspars during natural weathering and laboratory acid etching is controlled by their microtexture, especially by dislocations and exsolution lamellae. The core and strain energy associated with dislocation outcrops on (001) and (010) cleavage surfaces promotes rapid dissolution at those sites and formation of nn-sized etch pits after <30 s of laboratory etching with HF acid vapour. With progressive HF etching, crystallographically controlled differences in the reactivity of etch pit walls cause them to expand more rapidly into orthoclase than albite. Naturally weathered feldspars were collected from the glacial erratic boulders, fine gravels surrounding exposed granite surfaces, and from peat soil overlying the granite. During natural weathering, etch pits on microperthites enlarge almost exclusively by dissolution of albite and resin casts demonstrate that they can penetrate ?15 ?m below the cleavage surface, forming an interconnecting, ladder-like grid of submicrometer wide channels in the Murchison plane. Coherent albite platelets and volumes of albite between dislocations in films dissolve uniformly, but faster than orthoclase. This is probably because the albite lamellae have significant elastic coherency strain, but this is much less, per unit volume of albite, than the core and strain energy associated with edge dislocations. Patch perthites etch in HF vapour and weather rapidly in nature to produce a honeycomb-like texture of interconnecting nanometer- to micrometer-sized pits, which nucleate at preexisting micropores or incoherent subgrain boundaries. The size and density of etch pits on microperthite surfaces, which is determined by rates of growth and coalescence, may be a useful progress variable for natural and experimental dissolution. All alkali feldspars are highly heterogeneous materials whose chemical composition and microtexture can vary on a submicrometer scale. These microtextures are critical variables with regard to the origin of surface roughness of fresh and weathered grains, the controls on absolute dissolution rates and why they commonly change over time, the nonlinear variation of dissolution rate with grain size, the ratio of alkali ions released into solution, and disparities between laboratory dissolution rates and those observed in the field.

Lee, Martin R.; Parsons, Ian

1995-11-01

32

The role of reaction affinity and secondary minerals in regulating chemical weathering rates at the Santa Cruz Soil Chronosequence, California  

USGS Publications Warehouse

In order to explore the reasons for the apparent discrepancy between laboratory and field weathering rates and to determine the extent to which weathering rates are controlled by the approach to thermodynamic equilibrium, secondary mineral precipitation, and flow rates, a multicomponent reactive transport model (CrunchFlow) was used to interpret soil profile development and mineral precipitation and dissolution rates at the 226 ka Marine Terrace Chronosequence near Santa Cruz, CA. Aqueous compositions, fluid chemistry, transport, and mineral abundances are well characterized [White A. F., Schulz M. S., Vivit D. V., Blum A., Stonestrom D. A. and Anderson S. P. (2008) Chemical weathering of a Marine Terrace Chronosequence, Santa Cruz, California. I: interpreting the long-term controls on chemical weathering based on spatial and temporal element and mineral distributions. Geochim. Cosmochim. Acta 72 (1), 36-68] and were used to constrain the reaction rates for the weathering and precipitating minerals in the reactive transport modeling. When primary mineral weathering rates are calculated with either of two experimentally determined rate constants, the nonlinear, parallel rate law formulation of Hellmann and Tisserand [Hellmann R. and Tisserand D. (2006) Dissolution kinetics as a function of the Gibbs free energy of reaction: An experimental study based on albite feldspar. Geochim. Cosmochim. Acta 70 (2), 364-383] or the aluminum inhibition model proposed by Oelkers et al. [Oelkers E. H., Schott J. and Devidal J. L. (1994) The effect of aluminum, pH, and chemical affinity on the rates of aluminosilicate dissolution reactions. Geochim. Cosmochim. Acta 58 (9), 2011-2024], modeling results are consistent with field-scale observations when independently constrained clay precipitation rates are accounted for. Experimental and field rates, therefore, can be reconciled at the Santa Cruz site. Additionally, observed maximum clay abundances in the argillic horizons occur at the depth and time where the reaction fronts of the primary minerals overlap. The modeling indicates that the argillic horizon at Santa Cruz can be explained almost entirely by weathering of primary minerals and in situ clay precipitation accompanied by undersaturation of kaolinite at the top of the profile. The rate constant for kaolinite precipitation was also determined based on model simulations of mineral abundances and dissolved Al, SiO2(aq) and pH in pore waters. Changes in the rate of kaolinite precipitation or the flow rate do not affect the gradient of the primary mineral weathering profiles, but instead control the rate of propagation of the primary mineral weathering fronts and thus total mass removed from the weathering profile. Our analysis suggests that secondary clay precipitation is as important as aqueous transport in governing the amount of dissolution that occurs within a profile because clay minerals exert a strong control over the reaction affinity of the dissolving primary minerals. The modeling also indicates that the weathering advance rate and the total mass of mineral dissolved is controlled by the thermodynamic saturation of the primary dissolving phases plagioclase and K-feldspar, as is evident from the difference in propagation rates of the reaction fronts for the two minerals despite their very similar kinetic rate laws. ?? 2009 Elsevier Ltd.

Maher, K.; Steefel, C.I.; White, A.F.; Stonestrom, D.A.

2009-01-01

33

Tracking rainfall variations in the late Pleistocene using U isotopes in dated secondary soil minerals  

NASA Astrophysics Data System (ADS)

Past changes in rainfall are an important indicator of variations in atmospheric circulation. However, there are very few approaches that are uniquely sensitive to past changes in rainfall and use common materials that can be accurately dated. Secondary minerals in arid soils form directly from rainfall and can precipitate continuously over hundreds of thousands of years. Previous studies have used stable isotope measurements of soil carbonates to look at a variety of processes such as precipitation source and amount, evaporation, temperature, and vegetation. Often, the challenge with stable isotope approaches is to distinguish between these factors. In addition, stable isotope studies have not traditionally used high-resolution analytical techniques to capture the temporal variations within a given sample. The development of alternative isotopic systems that more directly reflect rainfall would provide a complimentary tool to more traditional strategies. In order to evaluate whether widely observed variations in the calculated initial U isotopic composition of dated soil minerals (e.g. (234U/238U)0) reflect changes in past rainfall, we sampled modern soil pore waters, soils and dust from a rainfall gradient in Fish Lake Valley, NV. In situ ion microprobe (SHRIMP-RG) techniques were used to determine the 230Th-U ages and (234U/238U)0 from uranium-rich soil opal collected at three field sites in western North America. Modern pore waters in desert soils from Fish Lake Valley, NV show systematic decreases in (234U/238U) with increasing rainfall. This is attributed to increasing infiltration flux and chemical weathering at higher rainfall rates, as the eolian influence should likely remain the same across the rainfall gradient. Although changes in the uranium concentration and isotopic composition of dust through time may also influence the (234U/238U) of soil water, these changes are likely minimal relative to changes in infiltration flux. The variations in (234U/238U)0 obtained from 230Th-U dating of soil opal span approximately the last 5-60 kyrs. Based on the modern pore water data, we interpret low (234U/238U)0 to indicate periods of higher rainfall, and high (234U/238U)0 to indicate periods of reduced rainfall. We observe nearly synchronous shifts during the last glacial-interglacial transition along the latitudinal transect of our field sites. Our initial results show that the transition from MIS 3 to 2 was likely characterized by increasing precipitation, with peak rainfall at the beginning of MIS 2. This corresponds to generally decreasing SST off of the California coast and rainier periods in speleothem records from the southwestern United States. Additionally (234U/238U)0 from our soil opal records co-varies with fluctuations in lake levels of large pluvial lake systems in western North America. The synchronous signal of increased rainfall during MIS 2 is consistent with a southward-shift in westerly storm tracks at the LGM. Our approach demonstrates an alternative method for increasing the spatial coverage and chronology of climate records in arid regions.

Ibarra, D. E.; Oster, J. L.; Maher, K.

2011-12-01

34

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

35

Surface exploration of Amphibalanus amphitrite cyprids on microtextured surfaces.  

PubMed

Microtopography is one of several strategies used by marine organisms to inhibit colonization by fouling organisms. While replicates of natural microtextures discourage settlement, details of larval interactions with the structured surfaces remain scarce. Close-range microscopy was used to quantify the exploration of cyprids of Amphibalanus amphitrite on cylindrical micropillars with heights of 5 and 30 ?m and diameters ranging from 5 to 100 ?m. While 5 ?m-high structures had little impact, 30 ?m-high pillars significantly influenced cyprid exploration. An observed step length decrease and step duration increase on 5 ?m diameter pillars is attributed to the small dimensions of the voids excluding the cyprid's attachment disc and consequently reducing the area of adhesive contact. When exploring larger diameter pillars, cyprids preferred using the voids to form temporary attachment points. This may enhance their resistance to flow. No-choice assay settlement patterns mirrored this exploration behaviour, albeit in a pattern counter to what was predicted. PMID:21547757

Chaw, Kuan Chun; Dickinson, Gary H; Ang, KaiYang; Deng, Jie; Birch, William R

2011-04-01

36

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

37

MDD Analysis of Microtexturally Characterized K-Feldspar Fragments  

NASA Astrophysics Data System (ADS)

Multiple diffusion domain (MDD) analysis of K-feldspar 40Ar/39Ar age spectra is a powerful thermochronological tool dating back 25 years, but continued validation of the basic assumptions of the model can be afforded by microanalysis of K-feldspar crystal fragments. MDD theory assumes that diffusion of Ar in K-feldspars is controlled by domains of varying size bounded by infinitely fast diffusion pathways. However, the physical character of these domain boundaries is not fully understood and this issue remains a point of criticism of the MDD model. We have evaluated the relationship between texture, age, and thermal history via step heating and modeling of texturally characterized K-feldspar crystal fragments (250-500 ?m). K-feldspar phenocrysts from the Shap granite, chosen for their well-studied and relatively simple microtextures, contain large areas of homogenous regular strain-controlled film perthite with periodicities on the order of ~1 ?m and abundant misfit dislocations, as well as areas of much coarser, irregular, slightly turbid, patch and vein perthite. Total gas ages (TGA) for all Shap fragments, regardless of texture, show less than 2% variation, but the shape of the age spectra varies with microtexture. Film perthites produce flat spectra whereas patch/vein perthite spectra have initial steps 5 - 25% older than the age of the emplacement with younger plateau or gently rising steps afterward. Patch/vein perthites have substantial microporosity and their spectral shapes may be a consequence of trapped 40Ar* that has diffused into micropores or other defects that have no continuity with the crystal boundaries. Correlations between spectral shape and heating schedule suggest that initial old ages are produced by the early release of trapped 40Ar* separated from the K parent rather than degassing of excess 40Ar*. The MH-42 K-feldspar from the Chain of Ponds Pluton has two primary microtextures: a coarse patch/vein perthite with lamellae 1-20 ?m in width and a sparse patch perthite with fine (<5 ?m) or absent lamellae. Most fragments produce age spectra, TGA, and thermal histories duplicating the bulk sample. However, several fragments deviate from the bulk sample in age and do not produce a thermal history compatible with any segment of the bulk sample thermal history. Arrhenius parameters are essentially constant for all fragments and thus do not explain large variations in the apparent ages of some fragments (i.e., TGA from ~220 to 318 Ma). These incompatible ages and thermal histories may be a result of late stage metasomatic growth or recrystallization. This work highlights the benefits of greater sample characterization before destructive step heating and grants new understanding of Ar behavior within plutonic K-feldspars. Newly installed high sensitivity multicollector mass spectrometers (ARGUS VI) will afford higher resolution age spectrum and in situ analysis on even smaller fragments. It is expected that these instruments will provide the precision necessary to enhance our understanding of MDD analysis as we move forward during the next 25 years of thermochronology.

Short, C. H.; Heizler, M. T.; Parsons, I.; Heizler, L.

2011-12-01

38

The role of intragranular microtextures and microstructures in chemical and mechanical weathering: direct comparisons of experimentally and naturally weathered alkali feldspars  

NASA Astrophysics Data System (ADS)

Electron microscopic observations of alkali feldspars from soils show that intragranular microtextures, such as exsolution lamellae, and microstructures, primarily dislocations, are both highly significant determinants of the weathering behaviour of these minerals. In particular, strained structure around intersecting edge dislocations in the plane of exsolution lamellae, ˜( overline601), dissolves at a rate which is orders of magnitude greater than unstrained feldspar, producing a mesh of intersecting etch tubes extending >5 × 10 -3 cm into the crystal. As a result, dissolution at dislocations is the major source of solutes during initial stages of chemical weathering in the field. With progressive chemical weathering, the most highly reactive feldspar is consumed by growth and coalescence of etch tubes, but outer parts of the grain are physically weakened, leading to mechanical flaking that increases available surface area and exposes further reactive sites. In contrast, previous dissolution experiments, and microscopy of reacted surfaces, have shown little or no correlation between dissolution rate and dislocation density and few visible signs of dissolution at particularly reactive sites. To resolve the apparent discrepancy between field and laboratory behaviour we have carried out flow-through dissolution experiments using pH 2 HCl at 25°C on three alkali feldspars with carefully characterized intragranular microtextures and microstructures. These alkali feldspars were: (1) Eifel sanidine, an alkali feldspar that has no microtextures at the TEM scale and a low dislocation density (<10 6 cm -2), (2) unweathered alkali feldspars from the Shep Granite, which have a mainly coarse exsolution microtextures and higher dislocation density (>2-3 × 10 8 cm -2), and (3) naturally weathered alkali feldspars, also from the Shap Granite, which have the same microtextures as unweathered Shap Granite alkali feldspars but, because they have been weathered, have a lower density of dissolution reactive dislocations exposed on grain surfaces (<2-3 × 10 8 cm -2). Results from the experiments are ambiguous. If the rate data are normalised to the powder's initial BET surface area, dissolution rates increase with dislocation density. Normalisation to the powder's BET surface area as it is inferred to have changed during the experiments, yields no correlation with dislocation density. SEM and AFM images of reacted grain surfaces show that dislocation outcrops and albite exsolution lamellae have both etched more rapidly than tweed orthoclase, but dissolution at these sites makes a quantitatively insignificant contribution to the overall rate of laboratory dissolution of the feldspar powders. Major differences in the importance of dislocations to rates of early chemical weathering in field and laboratory contexts probably result from corresponding contrasts in the saturation state of ambient solutions. Observations of naturally weathered alkali feldspars show that microtextures and microstructures have the greatest impact on mineral weathering rates during advanced stages of dissolution when grain surfaces start to disintegrate. Hundreds of years of dissolution under the laboratory conditions used here would be required to reach this stage.

Lee, Martin R.; Hodson, Mark E.; Parsons, Ian

1998-08-01

39

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

40

Secondary minerals and regolith profiles in basaltic rocks in northeastern US and in Svalbard, an Arctic Mars analogue site  

NASA Astrophysics Data System (ADS)

Data reported from the Mars Rovers, previous missions, and remote sensing have yielded a body of exciting evidence documenting that a Critical Zone nourished by water may also exist or have existed on Mars. However, the extent to which weathering is responsible for secondary mineral formation on Mars is not clear. We are investigating plagioclase and pyroxene weathering and precipitation of iron oxyhydroxides and clays in regolith profiles developed on rocks of basaltic composition from three different sites (Pennsylvania, Virginia, Svalbard), located in very different climatic conditions. Two of these sites were formed under a cool temperate climate, while the Svalbard profile is formed in a dry polar climate that has been identified as a Mars analogue. The two sites located in the northeastern US show similar rates of plagioclase dissolution, while slower rates were observed at Svalbard. Depth of weathering is also much greater in Pennsylvania and Virginia than in Svalbard, where weathering has only proceeded since the last glaciation. Nonetheless, weathering in Svalbard is accelerated by spalling of altered surfaces, presumably due to temperature cycling. We are using a variety of techniques including Fe isotope measurements to better understand secondary mineral precipitation in regolith. Knowledge of the climatic effects upon these processes on Earth can ultimately be applied to better understand weathering mechanisms on Mars.

Brantley, S. L.; Yesavage, T. A.; Bazilevskaya, E.

2011-12-01

41

minerals  

NASA Astrophysics Data System (ADS)

Polarized electronic absorption spectra of colourless chalcocyanite, CuSO4, have been measured using microscope-spectrometric techniques. The spectra are characterized by a structured and clearly polarized band system in the near-infrared spectral range with components centred at 11,720, 10,545, 9,100, and 7,320 cm-1, which have been assigned to crystal field d- d transitions of Cu2+ cations in pseudo-tetragonally elongated CuO6 polyhedra with point symmetry C i (). The polarization behaviour is interpreted based on a D 2( C 2?) pseudo-symmetry. Crystal field calculations were performed for the actual triclinic point symmetry by applying the Superposition Model of crystal fields, as well as in terms of a `classic' pseudo-tetragonal crystal field approach yielding the parameters Dq (eq) = 910, Dt = 395, and Ds = 1,336 cm-1, corresponding to a cubically averaged Dq cub = 679 cm-1. A comparative survey on crystal fields in Cu2+ minerals shows that the low overall crystal field strength in chalcocyanite, combined with a comparatively weak pseudo-tetragonal splitting of energy levels, is responsible for its unique colourless appearance among oxygen-based Cu2+ minerals. The weak crystal field in CuSO4 can be related to the lower position of the SO4 2- anion compared to, e.g. the H2O molecule in the spectrochemical series of ligands.

Wildner, Manfred; Giester, Gerald; Kersten, Monika; Langer, Klaus

2014-10-01

42

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

43

Secondary Mineral Genesis from Chlorite and Serpentine in an Ultramafic Soil Toposequence  

Microsoft Academic Search

synthesis of smectite in poorly drained soils. For exam- ple, Istok and Harward (1982) found smectite, chlorite, The origin of secondary phyllosilicates in serpentinitic soils of dif- and serpentine within poorly drained soils, but found fering moisture regimes is incompletely understood. The objective of only serpentine and chlorite in well-drained upland soils. this study was to determine the genesis of

B. D. Lee; S. K. Sears; R. C. Graham; C. Amrhein; H. Vali

2003-01-01

44

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

45

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

46

Natural radionuclide mobility and its influence on U–Th–Pb dating of secondary minerals from the unsaturated zone at Yucca Mountain, Nevada  

Microsoft Academic Search

Extreme U and Pb isotope variations produced by disequilibrium in decay chains of 238U and 232Th are found in calcite, opal\\/chalcedony, and Mn-oxides occurring as secondary mineral coatings in the unsaturated zone at Yucca Mountain, Nevada. These very slowly growing minerals (mmmy?1) contain excess 206Pb and 208Pb formed from excesses of intermediate daughter isotopes and cannot be used as reliable

L. A. Neymark; Y. V. Amelin

2008-01-01

47

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

48

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

49

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

NASA Astrophysics Data System (ADS)

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.

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

2013-10-01

50

Micro-textured conductive polymer/silicon heterojunction photovoltaic devices with high efficiency  

E-print Network

. Photonics 5, 234 (2012) Development of pulsed laser deposition for CdS/CdTe thin film solar cells Appl. PhysMicro-textured conductive polymer/silicon heterojunction photovoltaic devices with high efficiency://apl.aip.org/about/rights_and_permissions #12;Micro-textured conductive polymer/silicon heterojunction photovoltaic devices with high efficiency

51

Microtexture de fibres de carbure de silicium. Etude par microscopie lectronique par transmission  

E-print Network

229 Microtexture de fibres de carbure de silicium. Etude par microscopie électronique par fibres de carbure de silicium (Nicalon) par des techniques de microscopie électronique par transmission. Nous avons montré que toutes les fibres présentent une phase de carbure de silicium microcristallisée

Paris-Sud XI, Université de

52

Systematic variations in sinter mineralogy, microtexture and diagenesis in modern siliceous hot springs: Clues for interpreting depositional conditions in ancient deposits  

NASA Astrophysics Data System (ADS)

The deposits of siliceous hydrothermal springs are known to capture and preserve a wide range of microbial fossil information. The recent discovery of hydrothermal silica at Home Plate, Columbia Hills, Mars has once again raised interest in the potential importance of ancient spring sinters as targets for future astrobiological mission to Mars. To create additional context information to support future in situ missions to Mars, we have documented systematic changes in the mineralogy and microtexture of modern siliceous hot spring deposits, observed along gradients in temperature, pH and flow velocity. Specific objectives are to: 1) identify chemical and physical factors that promote early diagenetic transformations of amorphous silica (opal-A), to progressively more ordered and crystalline phases (cristobalite, tridymite and quartz); 2) determine the composition and abundance of minor mineral phases, especially clays, in relationship to pH, temperature and paragenesis; and 3) to assess the usefulness of sinter mineralogy and microtexture in reconstructing the paleoenvironmental records preserved in ancient deposits. Study sites for acidic (pH 2-5) sinters included Nymph Creek, located in the Norris Geyser Basin of Yellowstone National Park (YNP). Active alkaline (pH 7-10) springs included Rabbit Creek, Steep Cone and Mound Spring located in the Lower Geyser Basin, YNP. Field measurements in active springs included pH, temperature and flow velocity, along with general microfacies assignments. To better constrain types and rates of silica diagenesis, the study also sampled older (Holocene-Pleistocene-aged) deposits. Laboratory analyses included X-ray powder diffraction (XRPD), thermal infrared spectroscopy (TIR) and thin section petrography for characterizing sinter microtextures and for placing mineral phases (identified by XRPD and TIR) into a time-ordered diagenetic framework. In analyzing the phyllosilicates present in sinters, we applied clay separation and glycolization methods, with XRPD. Results indicate that all of the acidic sinters we studied showed more extensive early diagenetic ordering of silica phases (opal-A to cristobalite and quartz) than the comparable microfacies of alkaline-neutral sinters. Clay analyses showed no evidence for smectitic (expansive) clays, but kaolin family clays (dickite, kaolinite and halloysite) were present in both acidic and alkaline sinters. The microfacies distribution observed for clays suggests: 1) dickite being more abundant in higher temperature (near-vent) microfacies, 2) kaolinite dominating mid-temperature outflow channels, slope and upper distal apron microfacies, and 3) halloysite being restricted to lower distal apron-marsh microfacies transitions. Future work will expand clay analyses to apply near-IR spectroscopy to a broader range of samples to assess the consistency with patterns suggested from XRPD.

Mills, V. W.; Farmer, J. D.; Ruff, S. W.; Nunez, J.; Jahnke, L. L.

2011-12-01

53

A weakening mechanism for intermediate-depth seismicity? Detailed petrographic and microtextural observations from blueschist facies pseudotachylytes, Cape Corse, Corsica  

NASA Astrophysics Data System (ADS)

Gabbro- and peridotite-hosted pseudotachylytes from the Alpine Schistes Lustres Unit in Corsica, previously determined to have formed at blueschist to lawsonite-eclogite facies conditions, have been causally linked to the generation of intermediate-depth earthquakes, which occur at depths of 50-300 km. Detailed petrographic and microtextural analyses of these pseudotachylytes suggest that their initiation may be controlled by a thermally-activated shear runaway process that is controlled by rheology rather than mineralogy. This is documented by sheared out, prolate, kinked and twinned wallrock clasts that have been peeled off and entrained into the pseudotachylyte vein as sigmoid survivor clasts. The presence of metastable high temperature crystallisation products in the pseudotachylyte, such as hoppers and dendrites of olivine, enstatite and diopside (peridotite) and Al-rich omphacite and Fe-rich anorthite in metagabbro, are suggestive of a short-lived high-temperature event resulting from thermal instability. These high temperature mineral assemblages are overprinted by ones indicating a return to ambient conditions of lower temperatures, but still high pressures: glaucophane, albite and epidote in metagabbro and clinochlore; and fine-grained granoblastic olivine, enstatite and diopside in peridotite. The observations from this detailed study of natural samples suggest that intermediate-depth seismicity may be generated by a thermal runaway process.

Deseta, N.; Andersen, T. B.; Ashwal, L. D.

2014-01-01

54

The role of secondary minerals in controlling the migration of arsenic and metals from high-sulfide wastes (Berikul gold mine, Siberia)  

Microsoft Academic Search

The role of secondary minerals in controlling the migration of As, Cu, Zn, Pb and Cd has been investigated in piles of high-sulfide waste at the Berikul Au mine, Kemerovo region, Russia. These wastes contain 40–45 wt.% sulfides and have been stored for approximately 50 a near the Mokry Berikul river. Sulfide oxidation generates acid pore solutions (pH=1.7) with high

R Gieré; N. V Sidenko; E. V Lazareva

2003-01-01

55

Effects of oxyanions, natural organic matter, and bacterial cell numbers on the bioreduction of lepidocrocite (-FeOOH) and the formation of secondary mineralization products  

Microsoft Academic Search

Microbial reduction of Fe(III) oxides results in the production of Fe(II) and may lead to the subsequent formation of Fe(II)-bearing secondary mineralization products including magnetite, siderite, vivianite, chukanovite (ferrous hydroxy carbonate (FHC)), and green rust; however, the factors controlling the formation of specific Fe(II) phases are often not well-defined. This study examined effects of (i) a range of inorganic oxyanions

E. J. OLoughlin; Christopher A. Gorski; Michelle M. Scherer; Maxim I. Boyanov; Kenneth M. Kemner

2010-01-01

56

Microtexture and microstructure evolution during processing of pure aluminum by repetitive ECAP  

Microsoft Academic Search

Microtexture and microstructure evolution during repetitive equal-channel angular pressing (ECAP) of pure aluminum through a 90° die was evaluated by orientation imaging microscopy (OIM) and transmission electron microscopy (TEM). Billet distortion appears to conform to the idealized ECAP model. After the initial pass, the textures were inhomogeneous but one or more shear-texture components and long-range lattice rotations were apparent. Following

A. P. Zhilyaev; D. L. Swisher; K. Oh-ishi; T. G. Langdon; T. R. McNelley

2006-01-01

57

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

58

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

59

Heavy minerals in surficial sediments from lower Cook Inlet, Alaska  

USGS Publications Warehouse

Amphiboles, orthopyroxenes, and clinopyroxenes dominate the heavy mineral suite of surficial sediments in lower Cook Inlet, Alaska. Sources for these sediments include the igneous arc terrane of the northeast Alaska Range, reworked intrabasinal sediments, and local drainages in lower Cook Inlet. The distribution of these deposits is a reflection of both the tidal currents and the prevailing southerly net movement from the head of Cook Inlet. The heavy mineral studies concur with similar findings from gravel analyses, clay mineral investigations, and quartz microtexture observations. ?? 1984 Springer-Verlag New York Inc.

Wong, F. L.

1984-01-01

60

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

61

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

62

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

63

Microstructure and Microtexture Evolution of Shear Localization in Dynamic Deformation with Different Strains in Annealed Copper  

NASA Astrophysics Data System (ADS)

Shear localizations with different strains in annealed copper were obtained by a modified split Hopkinson pressure bar. Microstructure and microtexture evolution of the shear localization regions were examined using optical microscopy, electron backscatter diffraction technique, and transmission electron microscopy. The results show that both the mechanical response and deformation behavior are correlated closely to the shear strains. The elongated dislocation cells, stretched subgrains, and the refinement of subgrains are observed within shear localizations during dynamic deformation. Ultrafine grains of 100 to 300 nm with high-angle-boundaries are produced within the shear band with the shear strain of 5.8. Microtexture characterization reveals that a stable orientation, in which <110> directions of the crystals tend to align with the shear direction, develops both in the deformation and recrystallization areas. The {111} planes of the crystals tend to parallel to the shear plane in the deformation area, whereas the aggregated extent of this orientation becomes weak in the recrystallization area. In addition, some grains exist with the {100} planes parallel to the shear plane in the deformation and recrystallization areas. The rotational dynamic recrystallization is a reasonable mechanism for the microstructure evolution. The effects of cooling stage on the growth of grains and the change of dislocation density are estimated as a complementarity to this mechanism.

Tang, Lin; Chen, Zhiyong; Zhan, Congkun; Yang, Xuyue; Liu, Chuming

2013-02-01

64

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

65

Texture analysis of deformation induced martensite in an AISI 301L stainless steel: microtexture and macrotexture aspects.  

E-print Network

Texture analysis of deformation induced martensite in an AISI 301L stainless steel: microtexture, martensite. Introduction Metastable stainless steels are promising engineering materials due to a rewarding of martensite in austenitic stainless steels. The amount of martensite depends on processing parameters

Cambridge, University of

66

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

67

Effects of oxyanions, natural organic matter, and bacterial cell numbers on the bioreduction of lepidocrocite (gamma-FeOOH) and the formation of secondary mineralization products.  

PubMed

Microbial reduction of Fe(III) oxides results in the production of Fe(II) and may lead to the subsequent formation of Fe(II)-bearing secondary mineralization products including magnetite, siderite, vivianite, chukanovite (ferrous hydroxy carbonate (FHC)), and green rust; however, the factors controlling the formation of specific Fe(II) phases are often not well-defined. This study examined effects of (i) a range of inorganic oxyanions (arsenate, borate, molybdate, phosphate, silicate, and tungstate), (ii) natural organic matter (citrate, oxalate, microbial extracellular polymeric substances [EPS], and humic substances), and (iii) the type and number of dissimilatory iron-reducing bacteria on the bioreduction of lepidocrocite and formation of Fe(II)-bearing secondary mineralization products. The bioreduction kinetics clustered into two distinct Fe(II) production profiles. "Fast" Fe(II) production kinetics [19-24 mM Fe(II) d(-1)] were accompanied by formation of magnetite and FHC in the unamended control and in systems amended with borate, oxalate, gellan EPS, or Pony Lake fulvic acid or having "low" cell numbers. Systems amended with arsenate, citrate, molybdate, phosphate, silicate, tungstate, EPS from Shewanella putrefaciens CN32, or humic substances derived from terrestrial plant material or with "high" cell numbers exhibited comparatively slow Fe(II) production kinetics [1.8-4.0 mM Fe(II) d(-1)] and the formation of green rust. The results are consistent with a conceptual model whereby competitive sorption of more strongly bound anions blocks access of bacterial cells and reduced electron-shuttling compounds to sites on the iron oxide surface, thereby limiting the rate of bioreduction. PMID:20476735

O'Loughlin, Edward J; Gorski, Christopher A; Scherer, Michelle M; Boyanov, Maxim I; Kemner, Kenneth M

2010-06-15

68

Effects of oxyanions, natural organic matter, and bacterial cell numbers on the bioreduction of lepidocrocite ({gamma}-FeOOH) and the formation of secondary mineralization products.  

SciTech Connect

Microbial reduction of Fe(III) oxides results in the production of Fe(II) and may lead to the subsequent formation of Fe(II)-bearing secondary mineralization products including magnetite, siderite, vivianite, chukanovite (ferrous hydroxy carbonate (FHC)), and green rust; however, the factors controlling the formation of specific Fe(II) phases are often not well-defined. This study examined effects of (i) a range of inorganic oxyanions (arsenate, borate, molybdate, phosphate, silicate, and tungstate), (ii) natural organic matter (citrate, oxalate, microbial extracellular polymeric substances [EPS], and humic substances), and (iii) the type and number of dissimilatory iron-reducing bacteria on the bioreduction of lepidocrocite and formation of Fe(II)-bearing secondary mineralization products. The bioreduction kinetics clustered into two distinct Fe(II) production profiles. 'Fast' Fe(II) production kinetics [19-24 mM Fe(II) d-1] were accompanied by formation of magnetite and FHC in the unamended control and in systems amended with borate, oxalate, gellan EPS, or Pony Lake fulvic acid or having 'low' cell numbers. Systems amended with arsenate, citrate, molybdate, phosphate, silicate, tungstate, EPS from Shewanella putrefaciens CN32, or humic substances derived from terrestrial plant material or with 'high' cell numbers exhibited comparatively slow Fe(II) production kinetics [1.8-4.0 mM Fe(II) d-1] and the formation of green rust. The results are consistent with a conceptual model whereby competitive sorption of more strongly bound anions blocks access of bacterial cells and reduced electron-shuttling compounds to sites on the iron oxide surface, thereby limiting the rate of bioreduction.

O'Loughlin, E. J.; Gorski, C. A.; Scherer, M. M.; Boyanov, M. I.; Kemner, K. M.; Biosciences Division; Univ. of Iowa

2010-06-15

69

Oxygen-isotope composition of ground water and secondary minerals in Columbia Plateau basalts: implications for the paleohydrology of the Pasco Basin  

USGS Publications Warehouse

Concentrations of 18O and deuterium in ground waters beneath the Hanford Reservation, Washington State, suggest that the meteoric waters recharging the basalt aquifers have been progressively depleted in these isotopes since at least Pleistocene time. This conclusion is supported by oxygen-isotope analyses of low-temperature secondary minerals filling vugs and fractures in the basalts, which are used to approximate the 18O content of ground water at the time the mineral assemblage formed. A fossil profile of ??18O values projected for ground water in a 1500 m vertical section beneath the reservation suggests that the vertical mixing of shallow and deep ground water indicated by present-day hydrochemical data was also occurring during Neogene time. These data also suggest that a unidirectional depletion of 18O and deuterium recorded in Pleistocene ground waters may have extended considerably further back in time. This shift is tentatively attributed to the orographic depletion of 18O associated with the progressive uplift of the Cascade Range since the middle Miocene. -Authors

Hearn, Jr, P. P.; Steinkampf, W. C.; Horton, D. G.; Solomon, G. C.; White, L. D.; Evans, J. R.

1989-01-01

70

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

71

Microtexture and Nanoindentation Study of Delamination Cracking in Al-Cu-Li-X Alloys  

NASA Technical Reports Server (NTRS)

Commercial Al-Li alloys have strength and weight advantages over non-Li aluminum alloys. The fracture behavior of these alloys is unusual and has limited their use. The fracture mode, described as delamination, is intergranular, along the broad grain boundaries parallel to the rolling plane of the plate. Microtexture analyses have shown that delaminations occur along boundaries with greater than 30 misorientation. However, it was observed that relatively few of the high angle boundaries exhibited this behavior. Some grains of the retained deformation texture show high internal misorientation, which is a measure of stored strain energy. Delamination tends to occur between these grains and adjacent, recrystallized grains. Nanoindentation studies indicate a higher hardness for the high internal misorientation grains. These results suggest that the delamination could be reduced by processing the alloys to minimize grain-to-grain property disparities.

Crooks, R.; Domack, M. S.; Wagner, J. A.

2005-01-01

72

Mechanisms for transition in eruptive style at a monogenetic scoria cone revealed by microtextural analyses (Lathrop Wells volcano, Nevada, U.S.A.)  

NASA Astrophysics Data System (ADS)

Explosive activity at Lathrop Wells volcano, Nevada, U.S.A. originated with weak Strombolian (WS) eruptions along a short fissure, and transitioned to violent Strombolian (VS) activity from a central vent, with lava effusion during both stages. The cause for this transition is unknown; it does not reflect a compositional change, as evidenced by the consistent bulk geochemistry of all the eruptive products. However, comparison of agglutinate samples from the early, WS events with samples of scoria from the later, VS events reveal differences in the abundance and morphology of groundmass phases and variable textures in the rims of olivine phenocrysts. Scanning electron microscope (SEM) examination of thin sections from the WS samples show euhedral magnetite microlites in the groundmass glass and olivine phenocrysts show symplectite lamellae in their rims. Secondary ion mass spectrometry (SIMS) depth profiles of these symplectites indicate they are diffusion-controlled. The calculated DFe-Mg allows an estimation of the oxygen fugacity ( fO2) and indicates an increased fO2 during eruption of the WS products. Conversely, the VS samples show virtually no magnetite microlites in the groundmass glass, a lack of symplectites in the olivines, and a lower calculated fO2. These microtextural features suggest that the Lathrop Wells trachybasalt experienced increased oxidation during WS activity. As magma ascended through the original fissure, exsolved bubbles were concentrated in the wider part(s) (the protoconduit) and this bubble flux drove convective circulation that oxidized the magma through exposure to atmosphere and recirculation. This oxidation resulted in groundmass crystallization of magnetite within the melt and formation of symplectites within the olivine phenocrysts. Bubble-driven convection mixed magma vertically within the protoconduit, keeping it fluid and driving Strombolian bursts, while microlite crystallization in narrower parts of the fissure helped to focus flow. Development of a central conduit increased the magma ascent velocity (due to a greater product volume in the later eruptive stages) and caused the shift in eruption intensity. Consequently, variations in microtextures of the Lathrop Wells products reveal how a combination of fluid dynamic and crystallization processes in the ascending magma resulted in different styles of activity while the products maintained a consistent bulk composition.

Genareau, Kimberly; Valentine, Greg A.; Moore, Gordon; Hervig, Richard L.

2010-07-01

73

Effect of Pad Surface Micro-Texture on Removal Rate during Interlayer Dielectric Chemical Mechanical Planarization Process  

NASA Astrophysics Data System (ADS)

The effect of pad surface micro-texture on removal rate in interlayer dielectric chemical mechanical planarization was investigated. Blanket 200-mm oxide wafers were polished on a Dow® IC1000TM K-groove pad conditioned at two different conditioning forces. The coefficient of friction increased slightly (by 7%) while removal rate increased dramatically (by 65%) when conditioning force was increased from 26.7 to 44.5 N. Pad surface micro-texture analysis results showed that pad surface contact area decreased dramatically (by 71%) at the conditioning force of 44.5 N, leading to a sharp increase in the local contact pressure and resulting in a significantly higher removal rate.

Liao, Xiaoyan; Zhuang, Yun; Borucki, Leonard J.; Cheng, Jiang; Theng, Siannie; Ashizawa, Toranosuke; Philipossian, Ara

2013-01-01

74

Response of bone marrow derived connective tissue progenitor cell morphology and proliferation on geometrically modulated microtextured substrates  

PubMed Central

Varying geometry and layout of microposts on a cell culture substrate provides an effective technique for applying mechanical stimuli to living cells. In the current study, the optimal geometry and arrangement of microposts on the polydimethylsiloxane (PDMS) surfaces to enhance cell growth behavior were investigated. Human bone marrow derived connective tissue progenitor cells were cultured on PDMS substrates comprising unpatterned smooth surfaces and cylindrical post microtextures that were 10 µm in diameter, 4 heights (5, 10, 20 and 40 µm) and 3 pitches (10, 20, and 40 µm). With the same 10 µm diameter, post heights ranging from 5 to 40 µm resulted in a more than 535000 fold range of rigidity from 0.011 nNµm?1 (40 µm height) up to 5888 nNµm?1(5 µm height). Even though shorter microposts result in higher effective stiffness, decreasing post heights below the optimal value, 5 µm height micropost in this study decreased cell growth behavior. The maximum number of cells was observed on the post microtextures with 20 µm height and 10 µm inter-space, which exhibited a 675% increase relative to the smooth surfaces. The cells on all heights of post microtextures with 10 µm and 20 µm inter-spaces exhibited highly contoured morphology. Elucidating the cellular response to various external geometry cues enables us to better predict and control cellular behavior. In addition, knowledge of cell response to surface stimuli could lead to the incorporation of specific size post microtextures into surfaces of implants to achieve surface-textured scaffold materials for tissue engineering applications. PMID:23378044

Kim, Eun Jung; Fleischman, Aaron J.; Muschler, George F.; Roy, Shuvo

2013-01-01

75

Lower fibroblast growth factor 23 levels in young adults with Crohn disease as a possible secondary compensatory effect on the disturbance of bone and mineral metabolism.  

PubMed

Fibroblast growth factor 23 (FGF-23) is a bone-derived circulating phosphaturic factor that decreases serum concentration of phosphate and vitamin D, suggested to actively participate in a complex renal-gastrointestinal-skeletal axis. Serum FGF-23 concentrations, as well as various other laboratory parameters involved in bone homeostasis, were measured and analyzed with regard to various diseases and patients' characteristics in 44 patients with Crohn disease (CD) and 20 healthy controls (HCs) included in this cross-sectional study. Serum FGF-23 levels were significantly lower in patients with CD (900.42 ± 815.85pg/mL) compared with HC (1410.94 ± 1000.53pg/mL), p = 0.037. Further analyses suggested FGF-23 as a factor independent from various parameters including age (r = -0.218), body mass index (r = -0.115), 25-hydroxy vitamin D (r = 0.126), parathyroid hormone (r = 0.084), and bone mineral density (BMD) of hip and lumbar (r = 0.205 and r = 0.149, respectively). This observation remained even after multivariate analyses, exhibiting that BMD was not affected by FGF-23, although parameters such as age (p = 0.026), cumulative prednisolone dose (p < 0.0001), and smoking status (p = 0.024) were strong determinants of BMD regarding hip. Lower FGF-23 levels in patients with bowel inflammation are accompanied but not directly correlated with lower vitamin D levels, showing no impact on BMD determination of young adults with CD. The downregulation of serum FGF-23 levels in CD appears as a secondary compensatory effect on the bone and mineral metabolism induced by chronic intestinal inflammation. PMID:23623649

Oikonomou, Konstantinos A; Orfanidou, Timoklia I; Vlychou, Marianna K; Kapsoritakis, Andreas N; Tsezou, Aspasia; Malizos, Konstantinos N; Potamianos, Spyros P

2014-01-01

76

RADIOACTIVE DEMONSTRATION OF FINAL MINERALIZED WASTE FORMS FOR HANFORD WASTE TREATMENT PLANT SECONDARY WASTE BY FLUIDIZED BED STEAM REFORMING 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.

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

2012-02-02

77

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

PubMed Central

The proper function of many tissues depends critically on the structural organization of the cells and matrix of which they are comprised. Therefore, in order to engineer functional tissue equivalents that closely mimic the unique properties of native tissues it is necessary to develop strategies for reproducing the complex, highly organized structure of these tissues. To this end, we sought to develop a simple method for generating cell sheets that have defined ECM/cell organization using microtextured, thermoresponsive polystyrene substrates to guide cell organization and tissue growth. The patterns consisted of large arrays of alternating grooves and ridges (50 ?m wide, 5 ?m deep). Vascular smooth muscle cells cultured on these substrates produced intact sheets consisting of cells that exhibited strong alignment in the direction of the micropattern. These sheets could be readily transferred from patterned substrates to non-patterned substrates without the loss of tissue organization. Ultimately, such sheets will be layered to form larger tissues with defined ECM/cell organization that spans multiple length scales. PMID:18377979

Isenberg, Brett C.; Tsuda, Yukiko; Williams, Corin; Shimizu, Tatsuya; Yamato, Masayuki; Okano, Teruo; Wong, Joyce Y.

2008-01-01

78

Flexible silver nanowire meshes for high-efficiency microtextured organic-silicon hybrid photovoltaics.  

PubMed

Hybrid organic-silicon heterojunction solar cells promise a significant reduction on fabrication costs by avoiding energy-intensive processes. However, their scalability remains challenging without a low-cost transparent electrode. In this work, we present solution-processed silver-nanowire meshes that uniformly cover the microtextured surface of hybrid heterojunction solar cells to enable efficient carrier collection for large device area. We systematically compare the characteristics and device performance with long and short nanowires with an average length/diameter of 30 ?m/115 nm and 15 ?m/45 nm, respectively, to those with silver metal grids. A remarkable power conversion efficiency of 10.1% is achieved with a device area of 1 × 1 cm(2) under 100 mW/cm(2) of AM1.5G illumination for the hybrid solar cells employing long wires, which represents an enhancement factor of up to 36.5% compared to the metal grid counterpart. The high-quality nanowire network displays an excellent spatial uniformity of photocurrent generation via distributed nanowire meshes and low dependence on efficient charge transport under a high light-injection condition with increased device area. The capability of silver nanowires as flexible transparent electrodes presents a great opportunity to accelerate the mass deployment of high-efficiency hybrid silicon photovoltaics via simple and rapid soluble processes. PMID:23167527

Chen, Ting-Gang; Huang, Bo-Yu; Liu, Hsiao-Wei; Huang, Yang-Yue; Pan, Huai-Te; Meng, Hsin-Fei; Yu, Peichen

2012-12-01

79

Mineral County Secondary Data Analysis  

E-print Network

% 7% 62% 13% Gender1 Male Female Male Female Male Female 50.8% 49.2% 50.1% 49.9% 49.2% 50 prevalence (Heart Attack) 4.0% 4.1% 6.0% All Sites Cancer 466.5 455.5 543.2 1 Community Health Data, MT, Missoula, and Ravalli Chronic Disease Hospitalization Rates County Montana Stroke1 Per 100

Maxwell, Bruce D.

80

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

81

A three dimensional scaffold with precise micro-architecture and surface micro-textures  

PubMed Central

A three-dimensional (3D) structure comprising precisely defined microarchitecture and surface micro-textures, designed to present specific physical cues to cells and tissues, may provide an efficient scaffold in a variety of tissue engineering and regenerative medicine applications. We report a fabrication technique based on microfabrication and soft lithography that permits for the development of 3D scaffolds with both precisely engineered architecture and tailored surface topography. The scaffold fabrication technique consists of three key steps starting with microfabrication of a mold using an epoxy-based photoresist (SU-8), followed by dual-sided molding of a single layer of polydimethylsiloxane (PDMS) using a mechanical jig for precise motion control; and finally, alignment, stacking, and adhesion of multiple PDMS layers to achieve a 3D structure. This technique was used to produce 3D Texture and 3D Smooth PDMS scaffolds, where the surface topography comprised 10 ?m-diameter/height posts and smooth surfaces, respectively. The potential utility of the 3D microfabricated scaffolds, and the role of surface topography, were subsequently investigated in vitro with a combined heterogeneous population of adult human stem cells and their resultant progenitor cells, collectively termed connective tissue progenitors (CTPs), under conditions promoting the osteoblastic phenotype. Examination of bone-marrow derived CTPs cultured on the 3D Texture scaffold for 9 days revealed cell growth in three dimensions and increased cell numbers compared to those on the 3D Smooth scaffold. Furthermore, expression of alkaline phosphatase mRNA was higher on the 3D Texture scaffold, while osteocalcin mRNA expression was comparable for both types of scaffolds. PMID:19524292

Mata, Alvaro; Kim, Eun Jung; Boehm, Cynthia A.; Fleischman, Aaron J.; Muschler, George F.; Roy, Shuvo

2013-01-01

82

High cesium concentrations in groundwater in the upper 1.2 km of fractured crystalline rock - Influence of groundwater origin and secondary minerals  

NASA Astrophysics Data System (ADS)

Dissolved and solid phase cesium (Cs) was studied in the upper 1.2 km of a coastal granitoid fracture network on the Baltic Shield (Äspö Hard Rock Laboratory and Laxemar area, SE Sweden). There unusually high Cs concentrations (up to 5-6 ?g L-1) occur in the low-temperature (<20 °C) groundwater. The material includes water collected in earlier hydrochemical monitoring programs and secondary precipitates (fracture coatings) collected on the fracture walls, as follows: (a) hydraulically pristine fracture groundwater sampled through 23 surface boreholes equipped for the retrieval of representative groundwater at controlled depths (Laxemar area), (b) fracture groundwater affected by artificial drainage collected through 80 boreholes drilled mostly along the Äspö Hard Rock Laboratory (underground research facility), (c) surface water collected in local streams, a lake and sea bay, and shallow groundwater collected in 8 regolith boreholes, and (d) 84 new specimens of fracture coatings sampled in cores from the Äspö HRL and Laxemar areas. The groundwater in each area is different, which affects Cs concentrations. The highest Cs concentrations occurred in deep-seated saline groundwater (median Äspö HRL: 4.1 ?g L-1; median Laxemar: 3.7 ?g L-1) and groundwater with marine origin (Äspö HRL: 4.2 ?g L-1). Overall lower, but variable, Cs concentrations were found in other types of groundwater. The similar concentrations of Cs in the saline groundwater, which had a residence time in the order of millions of years, and in the marine groundwater, which had residence times in the order of years, shows that duration of water-rock interactions is not the single and primary control of dissolved Cs in these systems. The high Cs concentrations in the saline groundwater is ascribed to long-term weathering of minerals, primarily Cs-enriched fracture coatings dominated by illite and mixed-layer clays and possibly wall rock micaceous minerals. The high Cs concentrations in the groundwater of marine origin are, in contrast, explained by relatively fast cation exchange reactions. As indicated by the field data and predicted by 1D solute transport modeling, alkali cations with low-energy hydration carried by intruding marine water are capable of (NH4+ in particular and K+ to some extent) replacing Cs+ on frayed edge (FES) sites on illite in the fracture coatings. The result is a rapid and persistent (at least in the order of decades) buildup of dissolved Cs concentrations in fractures where marine water flows downward. The identification of high Cs concentrations in young groundwater of marine origin and the predicted capacity of NH4+ to displace Cs from fracture solids are of particular relevance in the disposal of radioactive nuclear waste deep underground in crystalline rock.

Mathurin, Frédéric A.; Drake, Henrik; Tullborg, Eva-Lena; Berger, Tobias; Peltola, Pasi; Kalinowski, Birgitta E.; Åström, Mats E.

2014-05-01

83

Effects of bound phosphate on the bioreduction of lepidocrocite (?-FeOOH) and maghemite (?-Fe2O3) and formation of secondary minerals.  

PubMed

Natural Fe(III) oxides typically contain a range of trace elements including P. Although solution phase and adsorbed P (as phosphate) have been shown to impact the bioreduction of Fe(III) oxides and the formation of "biogenic" secondary minerals, little is known about the potential effects of occluded/incorporated phosphate. We have examined the bioreduction of Fe(III) oxides (lepidocrocite (?-FeOOH) and maghemite (?-Fe2O3)) containing 0-3 mass% P as "bound" (a term we use to include both adsorbed and occluded/incorporated) phosphate. Kinetic dissolution studies showed congruent release of Fe and P, suggesting that the phosphate in these materials was incorporated within the particles; however, 53% or 86% of the total phosphate associated with the lepidocrocites containing 0.7 or 3 mass% P, respectively, was extracted with 0.1 M NaOH and can be considered to be adsorbed, both to exterior surfaces and within micropores. In the absence of phosphate, lepidocrocite was rapidly reduced to magnetite by Shewanella putrefaciens CN32, and over time the magnetite was partially transformed to ferrous hydroxy carbonate (FHC). The presence of 0.2-0.7 mass% P significantly inhibited the initial reduction of lepidocrocite but ultimately resulted in greater Fe(II) production and the formation of carbonate green rust. The bioreduction of maghemite with and without bound phosphate resulted in solid-state conversion to magnetite, with subsequent formation of FHC. We also examined the potential redox cycling of green rust under alternating Fe(III)-reducing and oxic conditions. Oxidation of biogenic green rust by O2 resulted in conversion to ferric green rust, which was readily reduced back to green rust by S. putrefaciens CN32. These results indicate the potential for cycling of green rust between reduced and oxidized forms under redox dynamics similar to those encountered in environments that alternate between iron-reducing and oxic conditions, and they are consistent with the identification of green rust in soils/sediments with seasonal redox cycling. PMID:23909690

O'Loughlin, Edward J; Boyanov, Maxim I; Flynn, Theodore M; Gorski, Christopher A; Hofmann, Scott M; McCormick, Michael L; Scherer, Michelle M; Kemner, Kenneth M

2013-08-20

84

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

85

Cathodoluminescence (CL) of Lunar Minerals and Rocks  

NASA Astrophysics Data System (ADS)

Selected material from the lunar surface (Luna 16, 20, 24 missions) was investigated using a combination of CL microscopy and spectroscopy with locally resolved microanalytical methods (Micro-Raman, microprobe, SEM, PIXE) to get information about the mineralogy and the luminescence behavior. Although the general high iron content of most lunar minerals and rocks prevents luminescence activation, certain species on the moon show visible CL. The dominant luminescent minerals are plagioclases and minerals of the SiO2 group, but K-feldspar, zircon and Ca-phosphates show also CL emissions. The application of CL imaging reveals microtextures such as zonation, brecciation or deformation features, which are not discernable by other analytical methods. Spectral CL measurements show that the main luminescence activators in lunar minerals are structural defects, Mn2+, REE3+ and Fe3+. The results show principle similarities with terrestrial material but also significant differences (e.g., mineral association, no weathering, impact damage). The close relationship between specific conditions of formation/alteration, the defect structure, and the luminescence properties may provide important genetic information.

Götze, J.

2009-08-01

86

Release of bioactive transforming growth factor beta(3) from microtextured polymer surfaces in vitro and in vivo.  

PubMed

Transforming growth factor beta(3) (TGF-beta(3)) has been under investigation with the objective of improving wound healing. Yet, little experimental knowledge exists about applications of TGF-beta(3) in implantology and tissue engineering. The aims of this study were to determine the release kinetics and bioactivity of TGF-beta(3) released from microtextured silicone and poly-L-lactic acid (PLA) surfaces in vitro and in vivo. We loaded surfaces with 100 ng of TGF-beta(3). An in vitro assay showed that TGF-beta(3) was released in a burstlike manner. Released TGF-beta(3) was capable of inhibiting the proliferation of mink lung epithelial cells, indicating that released TGF-beta(3) had remained at least partly active. Subsequently, an in vivo experiment (1 h-3 days) was performed with implants loaded with TGF-beta(3). In cryosections, TGF-beta(3) activity was assessed by an in situ bioassay. We found that active TGF-beta(3) was released for up to 24 h. Furthermore, released TGF-beta(3) could be detected up to 320 microm from the implant. On the basis of these observations, we conclude that TGF-beta(3) loaded onto microtextured polymer membranes remains functional when released in vitro and in vivo and, therefore, may represent an alternative for introducing a growth factor into a wound to achieve long-term and long-range biological effects. PMID:12459064

Parker, J A T C; Brunner, G; Walboomers, X F; Von den Hoff, J W; Maltha, J C; Jansen, J A

2002-10-01

87

The distribution of secondary mineral phases along an eroding hillslope and its effect on carbon stabilization mechanisms and the fate of soil carbon fractions  

NASA Astrophysics Data System (ADS)

Soil redistribution processes can change soil carbon (C) dynamics drastically by moving carbon from high decomposition and re-sequestration environments at the eroding hillslope to low decomposition and burial at the depositional footslope and valley basin. This leads to not only spatially diverse soil carbon storage throughout the landscape, but also to qualitative changes of the transported carbon and the mineral phase. The interaction between those parameters and the effect on stabilization mechanisms for soil C are still a matter of debate. Here, we present an analysis that aims to clarify the bio/geo-chemical and mineralogical components involved in stabilizing C at various depths along an eroding cropped slope and how this affects the abundance of microbial derived carbon. We use the results of an incubation experiment combined with the abundance of amino sugars in different isolated soil C fractions as a tracer for the stability of the respective fraction. We applied further (i) a sequential extraction of the reactive soil phase using pyrophosphate, oxalate and dithionite-citrate-bicarbonate, and (ii) a qualitative analysis of the clay mineralogy, to analyze the changes in the mineral phase for the different isolated fractions along the slope transect. Our results emphasize the importance of physical protection within microaggregates to stabilize buried, chemically labile C. Our data further indicates that the stability of these aggregates is related to the presence of organo-mineral associations and poorly crystalline minerals. However, decreasing contents of these minerals with depth indicate a temporal limitation of this stabilization mechanism. Non-expandable clay minerals experience a relative enrichment at the depositional site while expandable clay minerals experience the same at the eroding site. These changes in clay mineralogy along the slope are partly responsible for the abundance of silt and clay associated C and the effectiveness of the clay fractions to stabilize C. In summary, our data clearly show that a variety of stabilization mechanisms together with changes in the organic and the mineral phase of soils need to be considered to understand this highly dynamic environment.

Doetterl, Sebastian; Cornelis, Jean-Thomas; Opfergelt, Sophie; Boeckx, Pascal; Bodé, Samuel; Six, Johan; Van Oost, Kristof

2014-05-01

88

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

89

Dynamics of the Barents-Kara ice sheet as revealed by quartz sand grain microtextures of the late Pleistocene Arctic Ocean sediments  

NASA Astrophysics Data System (ADS)

During the entire Quaternary, ice sheets advanced and retreated across the circum-Arctic margins in a series of climate related glacial-interglacial cycles. It is critical to obtain evaluation of the nature of initiated glaciers at the Arctic margins after the pronounced interglacial periods. In this study this will be done by inferring from glacially generated quartz sand grain surface microtextures and related sedimentology extracted from the central Arctic Ocean sediments. These microtextures can be correlated with the generation and fluctuations in the extent of the late Pleistocene Eurasian Ice Sheet i.e. Barents-Kara Ice Sheet. The central Arctic Ocean sediments in the Lomonosov Ridge, having been deposited after the late Pleistocene interglaciations and having had no internal hiatuses, provide an excellent time window for usage of quartz sand grain surface textures for evaluating possible evolving glaciers and continental ice sheets. This is based on the fact that iceberg and sea-ice transported quartz sand grains and their mechanically formed surface textures, created under high cryostatic stress, are diagnostic for glacier thickness and dynamics having been existed in sediment source areas. Sand-sized quartz grains in deep marine sediments favour iceberg or sea-ice transportation with characteristic content of microtextures formed prior this transportation. The sand grain surface microtextures and their frequencies of the selected submarine Lomonosov Ridge sediments during Marine Isotope Stage (MIS) 5 to MIS 3 are analysed using a scanning electron microscope (SEM). Coring during the Arctic Ocean 96 expedition (core 96/12-1pc) provided alternating clay to silty clay sediments which are characterised by prominent silt to sand-size containing intervals. The specific glacial crushing and high cryostatic stress generated features, such as high angularity, conchoidal fractures, steps and sub-parallel linear fractures, were observed from quartz sand grain surfaces. Continental ice generation and extent are evident soon after the Eemian interglaciation and the following MIS 4 stage shows the highest frequencies of glacigenic microtextures. The microtexture generation under high cryostatic pressure underneath ice more than 1 km thick, can be taken as concurrent signal of the temporal expansion of the northernmost continental ice sheets, which could easily have reached the shelf break of the Barents, Kara and western Laptev seas during that time.

Strand, Kari; Immonen, Ninna

2010-12-01

90

Malnutrition secondary to non-compliance with vitamin and mineral supplements after gastric bypass surgery: What can we do about it?  

PubMed Central

Summary Background: Nutritional deficiency due to loss of follow up and non-compliance with routine mineral and multivitamin supplements is not uncommonly encountered following bariatric surgery. In this report, and utilizing a case study, we will address issues related to loss of long term medical follow up and the measures that can be taken to prevent it in this patient population. Case Report: The case of a 38-year-old female patient who was recently managed for severe vitamin deficiency and iron deficiency anemia following bariatric surgery is presented. Non-compliance with routine vitamin and mineral supplements was believed to be the main culprit of her condition. Articles published in English addressing issues related to non-compliance with supplementations and regular follow up after bariatric surgery were accessed from PubMed and are discussed. Conclusions: Multiple factors affecting long term follow up and compliance have been studied including age, financial costs, distance from the clinic and psychiatric comorbidities. Preventive measures have also been tested and some of them have shown significant benefit. More research is needed to identify other modifiable factors and preventive measures influencing compliance and long term follow up following bariatric surgery. PMID:23569531

Ahmad, Dina S.; Esmadi, Mohammad; Hammad, Hazem

2012-01-01

91

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

92

Numerical and analytical study of the impinging and bouncing phenomena of droplets on superhydrophobic surfaces with microtextured structures.  

PubMed

The dynamics of droplets impinging on different microtextured superhydrophobic surfaces are modeled with CFD combined with VOF (Volume of Fluid) technique. The method is validated by experimental data and an analytical model (AM) that is used to predict the penetrating depth and the maximum spreading diameter of an impinging droplet. The effects of geometrical shapes and operating conditions on the spreading and bouncing behaviors of impinging droplets are investigated. Six surfaces with different shapes of pillars are considered, namely, triangular prism, square pillar, pentagonal prism, cylindrical pillar, and crisscross pillar surfaces. The bouncing ability of an impinging droplet on textured surfaces can be illustrated from three aspects, namely, the contact time, the ranges of velocities for rebound and the penetrating depth of liquid in the maximum spreading stage. The surface with crisscross pillars exhibits the best ability to rebound, which can be attributed to its large capillary pressure (PC) and its special structures that can capture air in the gaps during the impinging process. PMID:25203603

Quan, Yunyun; Zhang, Li-Zhi

2014-10-01

93

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.

94

Ore Minerals  

NSDL National Science Digital Library

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

Perkins, Dexter

95

Prevalence of vitamin D deficiency and secondary hyperparathyroidism during winter in pre-menopausal Bangladeshi and Somali immigrant and ethnic Finnish women: associations with forearm bone mineral density.  

PubMed

Secondary hyperparathyroidism (SHPT) is one of the outcomes of vitamin D deficiency that negatively affects bone metabolism. We studied the ethnic differences in vitamin D status in Finland and its effect on serum intact parathyroid hormone (S-iPTH) concentration and bone traits. The study was done in the Helsinki area (60°N) during January-February 2008. A total of 143 healthy women (20-48 years of age) from two groups of immigrant women (Bangladeshi, n 34 and Somali, n 48), and a group of ethnic Finnish women (n 61) were studied in a cross-sectional setting. Serum concentrations of 25-hydroxyvitamin D (S-25OHD) and S-iPTH were measured. Peripheral quantitative computed tomography measurements were taken at 4 and 66 % of the forearm length. In all groups, the distribution of S-25OHD was shifted towards the lower limit of the normal range. A high prevalence of vitamin D insufficiency (S-25OHD < 50 nmol/l) was observed (89·6 %) in the Somali group. The prevalence of SHPT (S-iPTH>65 ng/l) was higher (79·1 %) in Somali women than in Finnish women (16 %). There was a significant association between S-25OHD and S-iPTH (r - 0·49, P < 0·001). Ethnicity and S-25OHD together explained 30 % of the variation in S-iPTH. The total bone mass at all sites of the forearm, fracture load and stress-strain index was higher (P < 0·001) in Bangladeshi and Finnish women than in Somali women. The high prevalence of hypovitaminosis D, SHPT and low bone status in Somali women indicates a higher risk of osteoporosis. PMID:21824446

Islam, Md Zahirul; Viljakainen, Heli T; Kärkkäinen, Merja U M; Saarnio, Elisa; Laitinen, Kalevi; Lamberg-Allardt, Christel

2012-01-01

96

mineral sorters  

SciTech Connect

This article describes different types of mineral sorters used to preconcentrate run-of-mine ore. This method of preconcentration is feasible when the mineralized particles are liberated at a relatively coarse rock size, suitable for sorter processing, and when there is a reliable difference in a specific physical property between the valuable minerals and waste. This article reviews some of the latest models and applications of mineral sorting equipment, including those operating on photometric, radiometric, electrostatic and conductivity-magnetic principles.

Sassos, M.P.

1985-06-01

97

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

98

Mineral Properties  

NSDL National Science Digital Library

This site from the Mineralogical Society of America describes the physical properties of minerals in terms that kids will understand. The site also includes the definition of a mineral, an identification chart, and links to descriptions of the physical properties used to identify minerals.

Mineralogy 4 Kids; America, Mineralogical S.

99

Mineral oils  

NASA Technical Reports Server (NTRS)

The characteristics of lubricants made from mineral oils are discussed. Types and compositions of base stocks are reviewed and the product demands and compositions of typical products are outlined. Processes for commercial production of mineral oils are examined. Tables of data are included to show examples of product types and requirements. A chemical analysis of three types of mineral oils is reported.

Furby, N. W.

1973-01-01

100

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

101

Mineral Identification  

NSDL National Science Digital Library

Imagine you are hiking with your family and this shiney looking crystal catches your eye. You bring it home and no one in your family is able to tell you what it is. How do you find out? First you need to practice. Identifying minerals. Click on the following link. Identify all five minerals. On your peice of paper tell me their Name Color Luster Cleavage/Fracture Hardness Glenco simple mineral identification Now try and identify 7 real minerals using a virtual key. Answer the following questions What properties do you use to identify the mineral? Which ...

Rmesser

2010-11-16

102

Solubilization of magnesium-bearing silicate minerals and the subsequent formation of glushinskite by Aspergillus niger  

Microsoft Academic Search

Microbes may play a substantial role in the weathering and alteration of minerals. However, not enough concerns have been realized about the complexity of microbe-mineral interactions. The present work reports the interactions between fungi and minerals with emphasis on the role of silicate minerals as the metal donor for the precipitation of secondary mineral. Herein, two magnesium-bearing silicate minerals with

Lin Cai; Hou-Rong Xiao; Shu-Ming Huang; Han Li; Gen-Tao Zhou

2012-01-01

103

Mineral Identification  

NSDL National Science Digital Library

This lesson discusses the question 'What is a mineral?' in the context of the guessing game 'Animal, Vegetable, or Mineral?'. It introduces a definition of the term, discusses the criteria used in the definition, and presents the common physical properties used in mineral identification. The lesson includes an activity in which students observe and record the physical properties of ten specimens and attempt to identify them using an online reference for practice.

Pratte, John

104

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

105

Identifying Minerals from Their Infra-red Spectra.  

ERIC Educational Resources Information Center

Describes a British secondary school's use of a spectrometer to identify minerals. Discusses the origins of mineral spectra, the preparation of the specimen, the actual spectroscopic scanning, and the interpretation of the spectra. (TW)

Paterson, W. G.

1986-01-01

106

Mineral slurries  

SciTech Connect

A pumpable slurry of mineral particles, e.g., coal, in water contains 50 to 85% by weight of mineral particles based on the combined weight of mineral particles and water. The mineral component contains at least 30% by weight of coarse particles having a particle size in the range 5 to 50 mm, 10 to 40% by weight of fine particles having a particle size less than 200 micron and the balance to 100% of intermediate sized particles. The slurry is stable without the use of additives and can be pumped through a pipeline.

Baker, P.J.; Brookes, D.A.; Johnson, M.

1985-06-25

107

Mineral Identification  

NSDL National Science Digital Library

In this activity, students use written and online materials to answer a set of questions on the general properties and identification of minerals. They will learn about physical properties such as color, hardness, and cleavage; special properties such as fluorescence and effervescence; and complete a chart listing properties for a selection of minerals. Links to the necessary information are provided.

Passow, Michael

108

Mystery Minerals  

NSDL National Science Digital Library

In this activity, students will discover that minerals have specific characteristics that help to identify them. They will learn that minerals are formed by inorganic processes, are crystalline solids with an internal orderly arrangement of atoms, have specific chemical compositions, and have specific physical and chemical characteristics. They will also learn that minerals are commonly identified by the physical properties they possess, such as hardness, color, crystal shape, specific gravity, and streak. In addition, they will discover some other useful properties such as reaction with hydrochloric acid or a characteristic taste. They should also understand that color is not always a useful property for identifying minerals because it can vary. The students will also develop listening and observational skills and learn the uses of a few common minerals.

Morgan, Susan

109

Secondary parkinsonism  

MedlinePLUS

Parkinsonism - secondary; Atypical Parkinson disease ... to be less responsive to medical therapy than Parkinson's disease. ... Unlike Parkinson disease, secondary parkinsonism may stabilize or even improve if the underlying cause is treated. Brain problems, such ...

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.

Perkins, Dexter

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 Abdominoplasty  

Microsoft Academic Search

Background  Abdominoplasty is the most frequent excisional body contour procedure performed in aesthetic surgery. Secondary abdominoplasty\\u000a refers to a new excisional procedure for a patient who has previously undergone an excisional abdominoplasty. In the authors’\\u000a practice, more than 7% of abdominoplasties are secondary cases and deserve special consideration.\\u000a \\u000a \\u000a \\u000a Methods  The authors present a retrospective analysis of their experience with 21 secondary cases

P. S. Cormenzana; N. M. Samprón; F. J. Escudero-Nafs

2008-01-01

114

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.

115

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 ...

116

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.

Perkins, Dexter

117

Parkinsonismi secondari  

Microsoft Academic Search

\\u000a La diagnosi di malattia di Parkinson (MP) presuppone — oltre ai segni cardinali e alle modalità evolutive — la presenza di\\u000a una buona e persistente risposta alla terapia con levodopa. É questo un elemento essenziale nella diagnosi differenziale della\\u000a MP idiopatica dai parkinsonismi secondari, in cui la risposta alla levodopa è solitamente scarsa e di durata limitata.

Floriano Girotti; Vincenza Fetoni

118

Energy and mineral resource systems: An introduction  

Microsoft Academic Search

This book provides a welcome approach to understanding the fundamental role that energy and mineral resources play in the affairs of nations and individuals. Chapter 1 presents background material on energy in the human environment. Chapter 2 deals with historical changes in predominant energy sources, energy efficiencies based on the first and second laws of thermodynamics, potential utility of secondary

B. A. Tapp; J. R. Watkins

1990-01-01

119

Welcome to the Wonderful World of Rocks and Minerals  

NSDL National Science Digital Library

This unit on rocks and minerals for secondary students features six lessons that employ web-based resources. It features an introductory lesson on minerals that employs a web quest, and additional lessons on classifying and experimenting with rocks and minerals, the rock cycle, and a unit review lesson that takes the form of a 'Jeopardy' contest. Each lesson plan includes worksheets, required links, and a rubric for assessment. Relevant Pennsylvania Department of Education (PDE) science standards are also provided.

120

Mineralization of Bacteria  

Microsoft Academic Search

A variety of viable and nonviable bacteria became mineralized with hydroxyapatite when implanted in dialysis bags in the peritoneal cavities of rats. The microscopic pattern of mineral deposition appeared analogous to that in the formation of oral calculus. Since nonviable organisms were mineralized at an accelerated rate, bacterial metabolic processes may not be essential for mineralization.

A. A. Rizzo; G. R. Martin; D. B. Scott; S. E. Mergenhagen

1962-01-01

121

Introduction to Minerals  

NSDL National Science Digital Library

This activity can be used as the introduction for a unit on mineral or crystal structure. It requires the students to create shapes cooperatively and put them together. This is analogous to individual crystals forming or to minerals forming. They will understand that minerals are made up of structures in certain patterns, and that these structures determine some of the properties of the minerals.

122

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.

123

Diversity of bacterial iron mineralization  

NASA Astrophysics Data System (ADS)

Bacterial cells, growing naturally in freshwater and marine environments or experimentally in culture, can precipitate a variety of authigenic iron minerals. With the vast majority of bacteria biomineralization is a two-step process: initially metals are electrostatically bound to the anionic surfaces of the cell wall and surrounding organic polymers, where they subsequently serve as nucleation sites for crystal growth. The biogenic minerals have crystal habits and chemical compositions similar to those produced by precipitation from inorganic solutions because they are governed by the same equilibrium principles that control mineralization of their inorganic counterparts. As the latter stages of mineralization are inorganically driven, the type of biomineral formed is inevitably dependent on the available counter-ions, and hence, the chemical composition of the waters in which the microorganisms are growing. In oxygenated waters, iron hydroxides are a common precipitate and can form passively through the binding of dissolved ferric species to negatively charged polymers or when soluble ferrous iron spontaneously reacts with dissolved oxygen to precipitate as ferric hydroxide on available nucleation sites (e.g. bacteria). Alternatively, the metabolic activity of Fe(II)-oxidizing bacteria can induce ferric hydroxide precipitation as a secondary by-product. Ferric hydroxide may then serve as a precursor for more stable iron oxides, such as goethite and hematite via dissolution-reprecipitation or dehydration, respectively, or it may react with dissolved silica, phosphate or sulphate to form other authigenic mineral phases. Under suboxic to anoxic conditions, ferric hydroxide may be converted to magnetite, siderite, and iron sulphides through various reductive processes associated with organic matter mineralization. Under biologically controlled conditions, where mineralization is completely regulated, magnetotactic bacteria form magnetite and greigite as navigational tools to guide themselves into their preferred habitat. In general, the formation of iron biominerals is not difficult to achieve, bacteria simply provide charged surfaces that bind metals and they excrete metabolic waste products into the surrounding environment that induce mineralization. The ubiquitous presence of bacteria in aquatic systems and their inherent ability to biomineralize, therefore, makes them extremely important agents in driving both modern and ancient geochemical cycles.

Konhauser, Kurt O.

1998-05-01

124

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

125

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

NASA Astrophysics Data System (ADS)

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

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

2011-02-01

126

Mineral Commodity Profiles: Selenium  

USGS Publications Warehouse

Overview -- Selenium, which is one of the chalcogen elements in group 16 (or 6A) of the periodic table, is a semiconductor that is chemically similar to sulfur for which it substitutes in many minerals and synthetic compounds. It is a byproduct of copper refining and, to a much lesser extent, lead refining. It is used in many applications, the major ones being a decolorizer for glass, a metallurgical additive to free-machining varieties of ferrous and nonferrous alloys, a constituent in cadmium sulfoselenide pigments, a photoreceptor in xerographic copiers, and a semiconductor in electrical rectifiers and photocells. Refined selenium amounting to more than 1,800 metric tons (t) was produced by 14 countries in 2000. Japan, Canada, the United States, and Belgium, which were the four largest producers, accounted for nearly 85 percent of world production. An estimated 250 t of the world total is secondary selenium, which is recovered from scrapped xerographic copier drums and selenium rectifiers; the selenium in nearly all other uses is dissipated (not recoverable as waste or scrap). The present selenium reserve bases for the United States and the world (including the United States), which are associated with copper deposits, are expected to be able to satisfy demand for selenium for several decades without difficulty.

Butterman, W. C.; Brown, R. D., Jr.

2004-01-01

127

The degree of mineralization is a determinant of bone strength: a study on human calcanei  

Microsoft Academic Search

Strength of bones depends on bone matrix volume (BMV), bone microarchitecture, and also on the degree of mineralization of bone (DMB). We have recently shown in osteoporotic patients treated with alendronate that fracture risk decreased and bone mineral density increased with a parallel increase of the DMB due to prolonged secondary mineralization but without modifications of BMV or bone microarchitecture.

H Follet; G Boivin; C Rumelhart; P. J Meunier

2004-01-01

128

Mineral spirits poisoning  

MedlinePLUS

... the harmful effects from swallowing or breathing in mineral spirits. This is for information only and not ... The poisonous ingredients in mineral spirits are hydrocarbons, which ... only hydrogen and carbon. Examples are benzene and methane.

129

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

130

Bartering for Minerals.  

ERIC Educational Resources Information Center

Presents an activity in which students are assigned occupations that rely on specific minerals. To obtain the needed minerals, students learn how to trade services and commodities. Includes details on preparation, modeling behaviors, and printed materials. (DDR)

May, Kathie

2002-01-01

131

Vitamins and Minerals  

MedlinePLUS

... or mineral supplements. If your diet includes a wide variety of foods, including whole-grain products, fresh ... and minerals you need is to eat a wide variety of healthy foods and skip the vitamin ...

132

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

133

Seaweed minerals as nutraceuticals.  

PubMed

Seaweed is known as an abundant source of minerals. Mineral composition of seaweed is very changeable because of many exogenous and endogenous factors and differs also within the same species. Principally, seaweed is an excellent source of some essential elements. Mainly, iron and iodine are in high concentration. Seaweeds could be prospective as functional foods and also producers of mineral nutraceuticals. PMID:22054962

Mišurcová, Ladislava; Mach?, Ludmila; Orsavová, Jana

2011-01-01

134

American Strategic Minerals  

Microsoft Academic Search

American Strategic Minerals brings together seven contributors in the fields of marine studies, mining engineering, earth sciences, and economics to discuss and analyze strategic minerals. The future demands of the United States upon limited sources of supply are examined and there is an analysis of alternative sources of strategic minerals from the seabed, including copper, nickel, manganese, and cobalt. The

Mangone

1984-01-01

135

INTRODUCTION TO MINERALS  

NSDL National Science Digital Library

DESK Standard: Understand the basic properties of minerals. . DATES: You can begin this activity on December 11. You should complete it by December 15. OBJECTIVE: You will visit Web sites to learn more about minerals. You will record 10 interesting facts about minerals on a blank sheet of paper. After visiting the last Web ...

Hughes, Mr.

2005-10-23

136

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

137

Scientists observe fungi-dissolving minerals  

NASA Astrophysics Data System (ADS)

Ectomycorrhizal fungi (EMF) live in moist dark recesses and never see daylight. They cling to the roots of trees in boreal forests, break down soil minerals and supply essential elements and nutrients to the trees. Along the way, they play a distinct but not yet well-understood role in bioweathering, a process in which water, air, and organisms interact to break down soil minerals within the first few meters of Earth's surface. In a synthetically designed and controlled laboratory environment, Gazzè et al. cultured EMF; the researchers monitored the process as the fungi colonized a soil mineral on a petri dish over a period of 7 months. The authors then extracted individual grains of chlorite, a common soil-forming clay mineral, and cleaned the mineral surfaces to look at how the fungi had affected the mineral surfaces they came in contact with. Using atomic force microscopy, a specialized process that allows observations of three-dimensional features at nanometer (10-9 meter) scales, the authors found numerous primary channels, of the order of a micron (10-6 meters) in width and up to 50 nanometers in depth, from which smaller secondary channels extended outward. The network of channels resembled a herringbone-like pattern—evidence of dissolution by EMF.

Bhattacharya, Atreyee

2012-10-01

138

Distinctive Accessory Minerals, Textures and Crystal Habits in Biofilm Associated Gypsum Deposits  

NASA Astrophysics Data System (ADS)

Gypsum-depositing environments near Guerrero Negro, Baja California Sur, Mexico were investigated in order to differentiate the influence of microbial activity versus nonbiological processes upon sedimentary fabrics and minerals. Field sites were located in sabkhas (mudflats and anchialine pools) and in seawater concentration ponds in the salt production facility operated by Exportadora de Sal, S. A. Gypsum (CaSO4.2H2O) was classified according to sedimentary environment (e.g., mudflats, anchialine pools, saltern ponds, surface and subsurface sediments), sedimentary texture, mineral composition, crystal habit, brine composition and other geochemical and biological factors. Gypsum types that develop in the absence of biofilms include water column precipitates (pelagic grains) and subsedimentary crystalline discs that form from phreatic brine ripening. Subsedimentary gypsum forming in sabkha environments had a sinuous axial microtexture and poikilitically enclosed detrital particles whereas water column precipitates exhibited euhedral prismatic habits and extensive penetrative twinning. Gypsum that was influenced by biofilms included cumulate crusts and gypsooids / gypsolite developing in anchialine pools and in saltern concentration ponds. Gypsum precipitating within subaqueous benthic microbial mats, or biofilm/sediment surfaces offered compelling evidence of biofilm influence on crystal textures and habits. Biofilm effects include irregular high relief surface textures, accessory minerals (elemental sulfur, Ca-carbonate, Sr/Ca-sulfate, Mg-oxide and Mg- sulfate) and distinctive crystal habits. Elemental sulfur, Ca-carbonate, and Sr/Ca-sulfate are known byproducts of bacterially mediated sulfate reduction (BSR). Populations of gypsum crystals within biofilms exhibited euhedral to lensoidal morphologies with unique equant and distorted prismatic forms. These forms had been shown to arise from form- and face-specific inhibition by bioorganic functional groups (Cody, 1991; Cody and Cody 1991). Biofilms therefore may play an active role in influencing brine chemistry, inducing crystallization and modifying crystal habits, evidence of which is preserved in grain morphologies.

Vogel, M.; Des Marais, D.; Jahnke, L.; Parenteau, M.

2008-12-01

139

Rocks, minerals, and a dusty world  

SciTech Connect

The Earth`s troposphere and hydrosphere contain abundant naturally generated dust. The ultimate source materials from which the terrestrially produced dust is generated are the various rock types exposed at the Earth`s surface. Natural dust is a composite of (1) lithic, primary mineral grains; (2) mineral grains formed by secondary chemical reactions; (3) volcanic ash and dust; (4) salts from sea sprays; (5) extra-terrestrial dust; and (6) biologic materials. In this paper the various pathways to the natural generation of dust (via the hydrologic cycle) will be discussed, and two geologically well-known natural dust sources will be described, paying particular attention to quantitative measurements of the dusts from these areas. General dust studies that provide data on possibly global background levels will be presented as well.. A few general aspects of the mineralogical characterization of dust particles and a discussion of some of the mineralogy of several mineral groups are first presented. 89 refs., 39 figs.

Klein, C. [Univ. of New Mexico, Albuquerque, NM (United States)

1993-12-31

140

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

141

American Strategic Minerals  

SciTech Connect

American Strategic Minerals brings together seven contributors in the fields of marine studies, mining engineering, earth sciences, and economics to discuss and analyze strategic minerals. The future demands of the United States upon limited sources of supply are examined and there is an analysis of alternative sources of strategic minerals from the seabed, including copper, nickel, manganese, and cobalt. The book contains an examination of the investments that the United States has made in developing countries that could affect both the national security and national economy of America in the years ahead. After a review of minerals policy in the United States, the conflicting interests that influence the President and Congress in making decisions about strategic minerals, and other dimensions of strategic minerals, are exposed to clarify both the facts and myths about supply and demand, security and danger, and high and low prices.

Mangone, G.

1984-01-01

142

Weathering of Minerals  

NSDL National Science Digital Library

Students determine the % change in mass of mineral samples that have been placed in a rock tumbler. They graph the relationship between the hardness of the mineral and the % change in mass. They then consider why some of the mineral samples do not conform the the relationship they graphed. They investigate the physical properties of the outliers and consider how the physical properties contributed to the rate of weathering, and what kind of weathering occured in the rock tumbler.

Van Norden, Wendy

143

Mineral winning installations  

SciTech Connect

A mineral winning installation employs a plurality of plough bodies spaced apart along the mineral face and interconnected to form a common plough train which is moved in unison back and forth along the face. The plough bodies have high-pressure fluid emission nozzles and a high-pressure pipe line extending between the bodies supplies high pressure fluid to the nozzles, which discharge the fluid for impact with the mineral face.

Lobbe, A.

1980-04-15

144

Minerals Under the Microscope  

NSDL National Science Digital Library

This website provides an easy-to-understand introduction to the basics of optical mineralogy. Topics include the polarized light microscope, mineral shape and cleavage, relief, color and pleochroism, interference colors, extinction angles, twinning, opacity, vibration directions and mineral identification. The site features short, clear descriptions accompanied by photographs and drawings. This website would be useful as a concise introduction to the use of a petrographic microscope in identifying minerals.

Browning, Paul; Gladstone, Charlotte

2011-03-02

145

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

146

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

147

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.

148

MINERAL COMMODITY SUMMARIES 2002  

E-print Network

Thallium Thorium Tin Titanium Tungsten Vanadium Vermiculite Yttrium Zinc Zirconium #12;U.S. DEPARTMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . 192 Appendix C--A Resource/Reserve Classification for Minerals

Torgersen, Christian

149

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

150

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.

151

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.

152

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.

153

O and Pb isotopic analyses of uranium minerals by ion microprobe and UPb ages from the Cigar Lake deposit  

E-print Network

intergrown uranium minerals and oxygen isotopic analyes of uraninite from the unconformity-type Cigar LakeO and Pb isotopic analyses of uranium minerals by ion microprobe and U­Pb ages from the Cigar Lake uranium deposit. Secondary uranium minerals intergrown with uraninite, such as coffinite, USiO4ÁnH2O

Fayek, Mostafa

154

MINER{nu}A Test Beam Commissioning  

SciTech Connect

MINER{nu}A Main INjector ExpeRiment {nu}-A is a high-statistic neutrino scattering experiment that will ran in the NuMI Beam Hall at Fermilab. To calibrate the energy response of the MINER{nu}A detector, a beamline is being designed for the MINER{nu}A Test Beam Detector (TBD). The TBD is a replica of the full MINER{nu}A detector at small scale for calibration studies of the main detector. The beamline design consists of the following parts: a copper target, used to generate tertiaries from an incoming secondary beam; a steel collimator for tertiaries, which also serves as a dump for the incoming beam; a time of fight system (scintillator planes); four wire chambers, for angle measurements and tracking; and two dipole magnets, used as an spectrometer. During last October, the first commissioning run of the MINER{nu}A Test Beam took place in the Meson Test Beam Facility at Fermilab. We commissioned the target and collimator of the new tertiary beamline.

Higuera, A.; Castorena, J.; Urrutia, Z.; Felix, J. [Universidad de Guanajuato, Division De Ciencias e Ingenerias, Leon Gto., Mex (Mexico); Zavala, G. [Universidad de Guanajuato, DCEA, Guanajuato Gto., Mex (Mexico)

2009-12-17

155

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.

156

Reducing Miner Absenteeism.  

National Technical Information Service (NTIS)

The U.S. Bureau of Mines has prepared the report on strategies for maintaining high job attendance among underground coal miners because high absenteeism is a threat to miners' safety and seriously hampers productivity. A substantial number of research st...

R. H. Peters, M. R. Clingan, R. F. Randolph

1988-01-01

157

Minerals Yearbook 1989: Boron  

Microsoft Academic Search

U.S. production and sales of boron minerals and chemicals decreased during the year. Domestically, glass fiber insulation was the largest use for borates, followed by sales to distributors, textile-grade glass fibers, and borosilicate glasses. California was the only domestic source of boron minerals. The United States continued to provide essentially all of its own supply while maintaining a strong position

Lyday

1990-01-01

158

What is a Mineral?  

NSDL National Science Digital Library

This website, from the University Corporation for Atmospheric Research (UCAR), gives a description of minerals and the growth of crystals. The site offers various links with examples of different compositions and classifications of common minerals. The site provides three different levels of explanation--beginner, intermediate, and advanced.

2008-08-04

159

Minerals in Our Environment  

NSDL National Science Digital Library

This color poster shows how we use minerals in our everyday life. It depicts common household items (furniture, appliances, plumbing fixtures, personal products, etc.) which are keyed by number to short descriptions that provide information on the minerals used in the manufacture of these items.

160

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

161

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

162

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.

163

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

164

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

165

PSC 424: Rocks and Minerals  

NSDL National Science Digital Library

This is a webpage designed to give students access to basic information about rocks and minerals. Rocks and Minerals Introduction Video Basic Definitions- Mineral: a solid inorganic substance of natural occurrence Rock: a mixture of minerals Ways to identify a mineral: Hardness Luster (metallic/nonmetallic) Streak Color Rock Song Three basic rock types: Igneous Metamorphic Sedimentary Rock Cycle Animation ...

Graham, Ms.

2011-10-13

166

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. ...

Bates, Albion M.

2010-01-23

167

Minerals yearbook, 1993. Volume 1. Metals and minerals. Annual report  

SciTech Connect

This edition of the Mineral Yearbook discusses the performance of the worlwide minerals and materials industry during 1993 and provides background information to assist in interpreting that performance. Volume 1, Metals and Minerals, contains chapters on virtually all metallic and industrial mineral commodities important to the U.S. economy. A chapter on survey methods with a statistical summary of nonfuel minerals, and a chapters on trends in mining and quarrying in the metals and industrial mineral industries are also included.

NONE

1993-12-31

168

Vitamins and Minerals during Pregnancy  

MedlinePLUS

... It's been added to your dashboard . Vitamins and minerals during pregnancy Vitamins and minerals help give your body the nutrients it needs ... for some people to get enough vitamins and minerals in their foods. They may need to take ...

169

Elastic properties of minerals  

SciTech Connect

Investigations of the elastic properties of the main rock-forming minerals were begun by T.V. Ryzhova and K.S. Aleksandrov over 30 years ago on the initiative of B.P. Belikov. At the time, information on the elasticity of single crystals in general, and especially of minerals, was very scanty. In the surveys of that time there was information on the elasticity of 20 or 30 minerals. These, as a rule, did not include the main rock-forming minerals; silicates were represented only by garnets, quartz, topaz, tourmaline, zircon, beryl, and staurolite, which are often found in nature in the form of large and fairly high-quality crystals. Then and even much later it was still necessary to prove a supposition which now seems obvious: The elastic properties of rocks, and hence the velocities of elastic (seismic) waves in the earth`s crust, are primarily determined by the elastic characteristics of the minerals composing these rocks. Proof of this assertion, with rare exceptions of mono-mineralic rocks (marble, quartzite, etc.) cannot be obtained without information on the elasticities of a sufficiently large number of minerals, primarily framework, layer, and chain silicates which constitute the basis of most rocks. This also served as the starting point and main problem of the undertakings of Aleksandrov, Ryzhova, and Belikov - systematic investigations of the elastic properties of minerals and then of various rocks. 108 refs., 7 tabs.

Aleksandrov, K.S.; Prodaivoda, G.T.

1993-09-01

170

Exploitation of Antarctic minerals  

SciTech Connect

Exploitation of minerals either from continental shelves or land areas free of ice has yet to take place in the Antarctic. The paper considers pressures, commercial, strategic, and possible depletion of resources elsewhere that might encourage moves towards exploitation. A brief review is given of technical developments that will be required to allow minerals operators to establish themselves in the hostile Antarctic environment. Finally, the issues that arise in the control of mineral exploitation in a region not subject to conventional national authority are noticed and the necessary conditions for the supervision of such activity, and the protection of the Antarctic environment are outlined.

Crockett, R.N.; Clarkson, P.D.

1987-01-01

171

Mineral resources of Antarctica  

USGS Publications Warehouse

Although the existence of mineral deposits in Antarctica is highly probable, the chances of finding them are quite small. Minerals have been found there in great variety but only as occurrences. Manganese nodules, water (as ice), geothermal energy, coal, petroleum, and natural gas are potential resources that could perhaps be exploited in the future. On the basis of known mineral occurrences in Antarctica and relationships between geologic provinces of Antarctica and those of neighboring Gondwana continents, the best discovery probability for a base-metal deposit in any part of Antarctica is in the Andean orogen; it is estimated to be 0.075 (75 chances in 1,000).

Compiled and edited by Wright, Nancy A.; Williams, Paul L.

1974-01-01

172

Digging into Minnesota Minerals  

NSDL National Science Digital Library

The Digging into Minnesota Minerals Web site is part of the larger Minnesota State Department of Natural Resources site. These fun and interesting pages explain how Minnesota came to acquire its most common minerals over geologic time, what the basic types of rocks are, mining history of the state, the geology found in state parks, and much more. Included are basic descriptions, photographs, illustrations, and even educational activities for teachers related to the minerals. This well-designed site would be a great addition to any grade school or high school science curriculum.

173

The Density of Minerals  

NSDL National Science Digital Library

In this activity, students will learn to measure the density of various minerals. The activity will reinforce the usefulness of density as a physical test for identification of minerals. Using a selection of mineral specimens of varying densities, they will weigh each one in air, immerse it in a graduated cylinder of water, and measure the amount of water displaced by the specimen. Dividing the weight of the specimen by the volume of displaced water yields the density of the specimen. A student worksheet and discussion questions are provided.

2005-10-06

174

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.

Colosky, Kenneth

175

Private Mineral Gallery Walk  

NSDL National Science Digital Library

Students make and display posters of the mineral they researched throughout the semester. The instructor and TA review the posters while students answer questions as they walk around and examine each other's posters.

Perkins, Dexter

176

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

177

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

178

Ice is a Mineral  

NSDL National Science Digital Library

This is a lesson about the characteristics of ice as a mineral and how it compares to other minerals with respect to hardness. Learners will observe ice crystals, develop a hardness scale and position ice on it. Learners will also practice working collaboratively in a team. Activities include small group miming, speaking, drawing, and/or writing. This is lesson 3 of 12 in the unit, Exploring Ice in the Solar System.

179

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

180

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

181

Biomineralization of magnetic minerals  

NASA Astrophysics Data System (ADS)

New developments and discoveries in biomineralization have occurred almost continuously in the intervening decade since the previous IUGG quadrennial report on biomineralization and biomagnetism was published [Kirschvink, 1983]. Biomineralization is widespread in the biosphere and over 60 different inorganic minerals are produced by a variety of organisms from bacteria to humans [Lowenstam and Weiner, 1989]. The literature on biomineralization is interdisplinary, combining research in microbiology, biotechnology, physics, geology, and paleomagnetism. For paleomagnetism and rock magnetism, iron biomineralization of magnetic minerals is of prime importance. From a paleomagnetism perspective, biogenic magnetic minerals can be deposited in sediments and acquire a natural remanent magnetization that preserves a record of the ancient geomagnetic field. From a rock magnetism perspective, biogenic magnetic minerals provide novel sources of magnetic material for experimental studies in fine particle magnetism. Both perspectives are interrelated through a common goal of developing magnetic techniques to detect biogenic magnetic minerals in sediments and soils. For example, the extent to which iron biominerals contribute to the fine-grained magnetic mineral assemblages in freshwater and marine sediments is important for identifying and interpreting the magnetic record of environmental change [Oldfield, 1992; Reynolds and King, this issue].

Moskowitz, Bruce M.

1995-07-01

182

Are the iron carbonate minerals, ankerite and ferroan dolomite, like siderite, important in paleomagnetism?  

Microsoft Academic Search

Magnetic, Mössbauer effect, and thermal properties have been evaluated for specimens of the mineral ankerite and are contrasted with similar measurements reported for the mineral siderite to determine if ankerite (and ferroan dolomite), like siderite, may be important in paleomagnetism as a producer of secondary, spurious remanent moments as the result of oxidation in air. Our data indicate that ankerite

Brooks B. Ellwood; Burke Burkart; Krishnan Rajeshwar; Robert L. Darwin; Richard A. Neeley; Alden B. McCall; Gary J. Long; Margaret L. Buhl; Charles W. Hickcox

1989-01-01

183

2011 Minerals Yearbook U.S. Department of the Interior  

E-print Network

2011 Minerals Yearbook U.S. Department of the Interior U.S. Geological Survey TIN [ADVANCE RELEASE output), followed by Indonesia (17%), Peru (12%), Bolivia (8%), and Brazil (5%). in 2011, the world tin.S. Geological Survey (USGS) since that year. Secondary.--A significant quantity of alloy tin scrap was generated

184

ASSESSMENT OF ENVIRONMENTAL IMPACT OF THE MINERAL MINING INDUSTRY  

EPA Science Inventory

This report presents a multimedia (air, liquid and solid wastes) environmental assessment of the domestic mineral mining industry. The primary objective of the study was to identify the major pollution problems associated with the industry. A secondary objective was to define res...

185

Mineral sources and transport pathways for arsenic release in a coastal watershed, USA  

USGS Publications Warehouse

Metasedimentary bedrock of coastal Maine contains a diverse suite of As-bearing minerals that act as significant sources of elements found in ground and surface waters in the region. Arsenic sources in the Penobscot Formation include, in order of decreasing As content by weight: lo??llingite and realgar (c. 70%), arsenopyrite, cobaltite, glaucodot, and gersdorffite (in the range of 34-45%), arsenian pyrite ( glaucodot, arsenopyrite-cobaltian > arsenopyrite, cobaltite, gersdorffite, fine-grained pyrite, Ni-pyrite > coarse-grained pyrite. Reactions illustrate that oxidation of Fe-As disulphide group and As-sulphide minerals is the primary release process for As. Liberation of As by carbonation of realgar and orpiment in contact with high-pH groundwaters may contribute locally to elevated contents of As in groundwater, especially where As is decoupled from Fe. Released metals are sequestered in secondary minerals by sorption or by incorporation in crystal structures. Secondary minerals acting as intermediate As reservoirs include claudetite (c. 75%), orpiment (61%), scorodite (c. 450%), secondary arsenopyrite (c. 469/6), goethite (<4490 ppm), natrojarosite (<42 ppm), rosenite, melanterite, ferrihydrite, and Mn-hydroxide coatings. Some soils also contain Fe-Co-Ni-arsenate, Ca-arsenate, and carbonate minerals. Reductive dissolution of Fe-oxide minerals may govern the ultimate release of iron and arsenic - especially As(V) - to groundwater; however, dissolution of claudetite (arsenic trioxide) may directly contribute As(III). Processes thought to explain the release of As from minerals in bedrock include oxidation of arsenian pyrite or arsenopyrite, or carbonation of As-sulphides, and most models based on these generally rely on discrete minerals or on a fairly limited series of minerals. In contrast, in the Penobscot Formation and other metasedimentary rocks of coastal Maine, oxidation of As-bearing Fe-cobalt-nickel-sulphide minerals, dissolution (by reduction) of As-bearing secondary As and Fe hydroxide and sulphate minerals, carbonation and/or oxidation of As-sulphide minerals, and desorption of As from Fe-hydroxide mineral surfaces are all thought to be involved. All of these processes contribute to the occurrence of As in groundwaters in coastal Maine, as a result of variability in composition and in stability of the As source minerals. Arsenic contents of soils and groundwater thus reflect the predominant influence and integration of a spectrum of primary mineral reservoirs (instead of single or unique mineral reservoirs). Cycling of As through metasedimentary bedrock aquifers may therefore depend on consecutive stages of carbonation, oxidation and reductive dissolution of primary and secondary As host minerals. ?? 2008 AAG/ Geological Society of London.

Foley, N.K.; Ayuso, R.A.

2008-01-01

186

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

187

Minerals yearbook, 1993. Volume 1. Metals and minerals. Annual report  

SciTech Connect

This edition of the Minerals Yearbook discusses the performance of the worldwide minerals and materials industry during 1993 and provides background information to assist in interpreting that performance. It contains chapters on virtually all metallic and industrial mineral commodities important to the U.S. economy. A chapter on survey methods with a statistical summary of nonfuel minerals, and a chapter on trends in mining and quarrying in the metals and industrial mineral industries are also included.

NONE

1993-12-31

188

Minerals yearbook, 1994. Volume 1. Metals and minerals. Annual report  

SciTech Connect

The edition of the Minerals Yearbook discusses the performance of the worldwide minerals and materials industry during 1994 and provides background information to assist in interpreting that performance. The volume I, Metals and Minerals, contains chapters on virtually all metallic and industrial mineral commodities important to the U.S. economy. The volume also contains chapters on Survey Methods, a Statistical Summary of Nonfuel Minerals, and Trends in Mining and Quarrying.

NONE

1994-12-31

189

MINERAL RESOURCES POTENTIAL IN MOZAMBIQUE  

Microsoft Academic Search

Lehto, T. & Gonçalves, R. 2008. Mineral resources potential in Mozambique. Geo- logical Survey of Finland, Special Paper 48, 307-321, 9 figures. The metallic mineral, industrial mineral and construction material resources in Mo- zambique have been mapped as part of the Mineral Resources Management Capacity Building Project, financed by a grant provided by the Nordic Development Fund. A da- tabase

Tapio Lehto; Reinaldo Gonçalves

190

Mineral Physical Properties and Identification  

NSDL National Science Digital Library

This Physical Geology 101 lab consists of a chart which defines the physical properties and provides the means for determining the physical property of a mineral sample. Also presented is a table listing some of the aspects of the common lab minerals. Armed with an image of a mineral and a series of physical properties tests, students are asked to identify each mineral.

Harwood, Richard

2011-01-01

191

The Mineral and Gemstone Kingdom  

NSDL National Science Digital Library

The "Mineral and Gemstone Kingdom" allows one to sort and search for minerals and gemstones by alphabetical, chemical group, color, streak, hardness, crystal group, elemental affiliations, and dana classification. Includes image galleries of rocks, minerals and gemstones: pictures accompanied with physical descriptions of the rock or mineral. Also includes a glossary of terms.

2008-08-21

192

Mercury from mineral deposits and potential environmental impact  

USGS Publications Warehouse

Mercury deposits are globally distributed in 26 mercury mineral belts. Three types of mercury deposits occur in these belts: silica-carbonate, hot-spring, and Almaden. Mercury is also produced as a by-product from several types of gold-silver and massive sulfide deposits, which account for 5% of the world's production. Other types of mineral deposits can be enriched in mercury and mercury phases present are dependent on deposit type. During processing of mercury ores, secondary mercury phases form and accumulate in mine wastes. These phases are more soluble than cinnabar, the primary ore mineral, and cause mercury deposits to impact the environment more so than other types of ore deposits enriched in mercury. Release and transport of mercury from mine wastes occur primarily as mercury-enriched particles and colloids. Production from mercury deposits has decreased because of environmental concerns, but by-product production from other mercury-enriched mineral deposits remains important.

Rytuba, J.J.

2003-01-01

193

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.

194

Minerals Yearbook 1989: Boron  

SciTech Connect

U.S. production and sales of boron minerals and chemicals decreased during the year. Domestically, glass fiber insulation was the largest use for borates, followed by sales to distributors, textile-grade glass fibers, and borosilicate glasses. California was the only domestic source of boron minerals. The United States continued to provide essentially all of its own supply while maintaining a strong position as a source of sodium borate products and boric acid exported to foreign markets. Supplementary U.S. imports of Turkish calcium borate and calcium-sodium borate ores, borax, and boric acid, primarily for various glass uses, continued.

Lyday, P.A.

1990-08-01

195

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

196

Impact of nano-size weathering products on dissolution rates of primary minerals  

NASA Astrophysics Data System (ADS)

Weathering rates of primary minerals determined in field studies are typically orders of magnitude lower than mineral dissolution rates found in laboratory experiments. We propose that this discrepancy is due to a combination of two factors: (i) secondary minerals that form from the incongruent dissolution of primary phases are often nano-scale in size; (ii) field conditions are often far closer to equilibrium than those encountered in laboratory experiments. Using a non-standard formulation that relates interfacial free energy, crystal size, and degree of supersaturation to precipitation kinetics in a population of crystals growing in a supersaturated fluid, we demonstrate that the net rate of secondary mineral precipitation in systems that are close to equilibrium - and which possess a large number of micron and nanometer scale crystals - can be much lower than rates predicted by standard kinetic formulations. Furthermore, when crystals are small enough, net dissolution can dominate even when the system is supersaturated with respect to the secondary mineral, with standard kinetic models breaking down entirely. As the dissolution rates of primary minerals are thought to be determined by the rate of secondary mineral precipitation, standard kinetic models - which ignore interfacial free energy effects in small crystals - may therefore be unsuitable to describe reaction kinetics in weathering systems.

Emmanuel, S.; Ague, J. J.

2010-12-01

197

Hyperaldosteronism - primary and secondary  

MedlinePLUS

... hormone aldosterone into the blood. Hyperaldosteronism can be primary or secondary. ... Primary hyperaldosteronism is due to a problem of the adrenal glands themselves, causing them to release too ...

198

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

199

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

200

Bioleaching of Minerals  

SciTech Connect

Bioleaching is the term used to describe the microbial dissolution of metals from minerals. The commercial bioleaching of metals, particularly those hosted in sulfide minerals, is supported by the technical disciplines of biohydrometallurgy, hydrometallurgy, pyrometallurgy, chemistry, electrochemistry, and chemical engineering. The study of the natural weathering of these same minerals, above and below ground, is also linked to the fields of geomicrobiology and biogeochemistry. Studies of abandoned and disused mines indicate that the alterations of the natural environment due to man's activities leave as remnants microbiological activity that continues the biologically mediated release of metals from the host rock (acid rock drainage; ARD). A significant fraction of the world's copper, gold and uranium is now recovered by exploiting native or introduced microbial communities. While some members of these unique communities have been extensively studied for the past 50 years, our knowledge of the composition of these communities, and the function of the individual species present remains relatively limited. Nevertheless, bioleaching represents a major strategy in mineral resource recovery whose importance will increase as ore reserves decline in quality, become more difficult to process (due to increased depth, increased need for comminution, for example), and as environmental considerations eliminate traditional physical processes such as smelting, which have served the mining industry for hundreds of years.

F. Roberto

2002-02-01

201

Minerals and foreign policy  

Microsoft Academic Search

There is no such thing as a purely domestic or foreign minerals issue. Domestic policies, such as the setting aside of public lands as wilderness regions or enforcement of stringent clean air standards on smelters, may link directly to our world trade and supply position and affect foreign-policy interests. Conversely, economic and political events in far corners of the world

Calingaert

1980-01-01

202

Oxidants from Pulverized Minerals  

NASA Astrophysics Data System (ADS)

Joel Hurowitz (previously at State University of New York at Stony Brook and now at the Jet Propulsion Laboratory), Nick Tosca, Scott McLennan, and Martin Schoonen (SUNY at Stony Brook) studied the production of hydrogen peroxide from freshly pulverized minerals in solution. Their experiments focused on olivine, augite, and labradorite; silicate minerals of basaltic planetary surfaces, such as the Moon and Mars, that are exposed to the intense crushing and grinding of impact cratering processes. The hydrogen peroxide produced in the experiments was enough to adequately explain the oxidizing nature of Martian regolith first determined by the Viking Landers and the results suggest, for the first time, that mechanically activated mineral surfaces may be an important part of the overall explanation for the Viking Lander biology experiment results. Hurowitz and coauthors further showed that when the pulverized minerals are heat-treated to high temperature under vacuum (to cause dehydroxylation) there is almost a 20 times increase in hydrogen peroxide production, a result which may be highly relevant to lunar dust. These careful studies demonstrate the importance of and concern about reactive dusts on planetary surfaces from two standpoints: the health of astronauts on surface maneuvers who may inadvertently breath it and the viability of possible Martian organic species to survive in such a corrosive, antiseptic surface environment.

Martel, L. M. V.

2007-06-01

203

Universal ripper miner  

Microsoft Academic Search

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

Roger J. Morrell; David A. Larson

1991-01-01

204

Mineral mining equipment  

SciTech Connect

A mineral mining machine hauls itself along a working face by engaging a round link chain. The links of the chain are fed sequentially from link-retaining pockets in a track component arranged around the working face, around a driven sprocket assembly on the machine and returned to the pockets.

Monks, H.

1980-11-25

205

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.

206

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.

Heaton, Timothy

207

Minerals bioprocessing: R & D needs in mineral biobeneficiation  

Microsoft Academic Search

Microorganisms have a tremendous influence on their environment through the transfer of energy, charge, and materials across a complex biotic mineral–solution interface. The biomodification of mineral surfaces involves the complex action of microorganism on the mineral surface. The manner, in which bacteria affect the surface reactivity and the mechanism of bacteria adsorption, is still unknown and accumulation of the primary

K. Hanumantha Rao; A. Vilinska; I. V. Chernyshova

2010-01-01

208

Mineralogy and genesis of secondary uranium deposits, Um Ara area, south eastern desert, Egypt  

Microsoft Academic Search

Secondary U mineralisation is found in the oxidised zone pervading fractured albitised and alkali-feldspar granites emplaced at the northern boundary of Um Ara Pluton. It occurs as stains along crevices and fracture surfaces and as acicular crystals filling cavities. X-ray diffraction and SEM were used to identify secondary U minerals and the associated alteration products. Uranophane and ?-uranophane are the

Y. H. Dawood; H. H. Abd El-Naby

2001-01-01

209

Future of Secondary Services.  

ERIC Educational Resources Information Center

Argues that the major forces related to economic factors that effect the future of secondary services are growth of primary literature and expansion of secondary products; migration of use from print products to tape products; new technology and impact on production of products and services; and redefinition of user as end user. (EJS)

Neufeld, M. Lynne

1983-01-01

210

Mineral oil soluble borate compositions  

SciTech Connect

Alkali metal borates are reacted with fatty acids or oils in the presence of a low hlb value surfactant to give a stable mineral oil-soluble product. Mineral oil containing the borate can be used as a cutting fluid.

Dulat, J.

1981-09-15

211

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

212

Study on comprehensive utilization of secondary resources  

SciTech Connect

In light of the properties on process mineralogy of the old tailings in a certain copper mine in the People`s Republic of China, a new process of combined reagent and stepwise flotation is applied in which the flotation of copper sulfides is followed by the flotation of copper oxides. Recoveries of copper and associated gold and silver have been greatly increased. The tailings obtained were subjected to the gravitational separation-magnetic separation process to recover iron minerals. Tailings from iron separation are taken as fillers and sent to the pit underground. Thus, the secondary resources are comprehensively utilized.

Lihua, G.; Ruilu, L. [Beijing General Research Inst. of Mining and Metallurgy (China)

1995-12-31

213

Mineral Transformations by Mycorrhizal Fungi  

Microsoft Academic Search

This review addresses the significance and the mechanisms of mineral weathering by mycorrhizal fungi, and the role of this process in plant nutrition and protection from metal toxicity. The fact that mycorrhizal mycelia may actively release nutrients from mineral particles through weathering is raising an increasing interest and the uptake of mineral-derived nutrients by the host plants has been reported.

Elena Martino; Silvia Perotto

2010-01-01

214

The Indian Mineral Development Act.  

ERIC Educational Resources Information Center

Discusses the objectives of the Indian Mineral Development Act of 1982 (IMDA) and the possible effects it may have on Indian mineral development. Explains how the provisions of IMDA work to provide Indian tribes with greater flexibility for the development and sale of their mineral resources. (ML)

Houle, Antoinette

1986-01-01

215

Common Rock-Forming Minerals  

NSDL National Science Digital Library

This is a collection of images of the common rock-forming minerals. Along with the image, the physical and chemical properties of each mineral are listed. These include: metallic or nonmetallic luster, light or dark color, chemical formula, mineral group, cleavage, general color, hardness, and other characteristics.

Weiland, Tom

216

Minerals yearbook, 1992. Volume 1. Metals and minerals. Annual report  

SciTech Connect

This edition of the Minerals Yearbook discusses the performance of the worldwide mineral and materials industry during 1992 and provides background information to assist in interpreting that performance. Content of the individual Yearbook volumes follows: Volume I, Metals and Minerals, contains chapters on virtually all metallic and industrial mineral commodities important to the U.S. economy. Chapters on advanced materials, nonrenewable organic materials, and nonferrous metals recycling also were added to the Minerals Yearbook series beginning with the 1989, 1990, and 1991 volumes, respectively. A new chapter on materials recycling has been initiated in this 1992 volume. In addition, a chapter on survey methods used in data collection with a statistical summary of nonfuel minerals and a chapter on trends in mining and quarrying in the metals and industrial mineral industries are included.

Not Available

1992-01-01

217

Mineral mining installation  

SciTech Connect

A mineral mining installation comprises a mechanical mining machine (such as a plough or a shearer) and a hydraulic winning machine. The hydraulic winning machine has a plurality of high pressure nozzles and a high-pressure pump for supplying the nozzles with high-pressure water (or other hydraulic fluid). Means are provided for driving each of the two winning machines independently of the other along a mineral face. This permits the mechanical winning machine to operate at its optimum, high speed rate without interference from the slower moving hydraulic winning machine. The pump is preferably a multiple radial-piston pump powered by an electric motor. Both electric power and water may be supplied to the hydraulic winning machine via pick-up arms on the machine and supply channels extending along the face.

Beckmann, K.; Grisebach, H.

1981-02-17

218

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

219

Silicosis in barium miners.  

PubMed Central

Four men who mined barytes in Scotland and who developed pneumoconiosis are described. Three developed progressive massive fibrosis, from which two died; and one developed a nodular simple pneumoconiosis after leaving the industry. The radiological and pathological features of the men's lungs were those of silicosis and high proportions of quartz were found in two of them post mortem. The quartz was inhaled from rocks associated with the barytes in the mines. The features of silicosis in barium miners are contrasted with the benign pneumoconiosis, baritosis, that occurs in workers exposed to crushed and ground insoluble barium salts. Diagnostic difficulties arise when silicosis develops in workers mining minerals known to cause a separate and benign pneumoconiosis. These difficulties are compounded when, as not infrequently happens, the silicotic lesions develop or progress after exposure to quartz has ceased. Images PMID:3787542

Seaton, A; Ruckley, V A; Addison, J; Brown, W R

1986-01-01

220

Taxation of mineral resources  

SciTech Connect

There has been a substantial increase in recent years in the level of taxation imposed on mining firms by state and local governments. This increase can be attributed to three factors: (1) a heightened awareness that resources are limited in quantity; (2) environmental damage resulting from mining operations has brought demands for just compensations; and (3) significant price increases for some minerals have often been viewed by states as an opportunity to collect additional tax revenue. The broad aim of this book is to provide a comprehensive economic analysis of the effects of mining taxation on the extraction of mineral resources and to offer a set of recommendations for tax policy. The primary objective of this design is to minimize the distortionary incentives created by the taxation. From a practical standpoint, however, one must also recognize the degrees of difficulty in the administration of the various taxes. 90 references, 1 figure, 14 tables.

Conrad, R.F.; Hool, R.B.

1980-01-01

221

Nutrition or detoxification: why bats visit mineral licks of the Amazonian rainforest.  

PubMed

Many animals in the tropics of Africa, Asia and South America regularly visit so-called salt or mineral licks to consume clay or drink clay-saturated water. Whether this behavior is used to supplement diets with locally limited nutrients or to buffer the effects of toxic secondary plant compounds remains unclear. In the Amazonian rainforest, pregnant and lactating bats are frequently observed and captured at mineral licks. We measured the nitrogen isotope ratio in wing tissue of omnivorous short-tailed fruit bats, Carollia perspicillata, and in an obligate fruit-eating bat, Artibeus obscurus, captured at mineral licks and at control sites in the rainforest. Carollia perspicillata with a plant-dominated diet were more often captured at mineral licks than individuals with an insect-dominated diet, although insects were more mineral depleted than fruits. In contrast, nitrogen isotope ratios of A. obscurus did not differ between individuals captured at mineral lick versus control sites. We conclude that pregnant and lactating fruit-eating bats do not visit mineral licks principally for minerals, but instead to buffer the effects of secondary plant compounds that they ingest in large quantities during periods of high energy demand. These findings have potential implications for the role of mineral licks for mammals in general, including humans. PMID:18431492

Voigt, Christian C; Capps, Krista A; Dechmann, Dina K N; Michener, Robert H; Kunz, Thomas H

2008-01-01

222

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.

223

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

224

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

225

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

226

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

227

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

228

Systems genetics of mineral metabolism.  

PubMed

Minerals are essential and toxic elements that have an impact on human health. Although we have learned a tremendous amount about the metabolism, biological roles, and health effects of minerals with the tools of biochemistry, cell biology, and molecular genetics, there are gaps in our knowledge of mineral biology that will benefit from new approaches. Forward genetics, whereby variations in phenotypes are mapped to natural genetic variation in the genome, has been successfully used to increase our understanding of many biologically important traits but has not yet been used extensively for mineral metabolism. In addition, the well-appreciated existence of interactions between minerals justifies a broader, systems approach to the study of mineral metabolism, i.e., ionomics. This short review will explain the value of forward genetics and ionomics as tools for exploring mammalian mineral metabolism. PMID:21270371

Fleet, James C; Replogle, Rebecca; Salt, David E

2011-03-01

229

Secondary Alkaline Batteries.  

National Technical Information Service (NTIS)

This report on secondary alkaline batteries covers the overall reactions (charge/discharge characteristics), electrode structures and materials, and cell construction. The following batteries are studied, nickel oxide-cadmium, nickel oxide-iron, nickel ox...

J. McBreen

1984-01-01

230

Neuropathy secondary to drugs  

MedlinePLUS

Neuropathy secondary to drugs is a loss of sensation or movement in a part of the body ... weakness. Many medications may affect the development of neuropathy, including: Heart or blood pressure medications Amiodarone Hydralazine ...

231

Are colors Secondary Qualities?  

E-print Network

Introduction: Seventeenth- and eighteenth-century discussions of the senses are often thought to contain a profound truth: some perceptible properties are secondary qualities, dispositions to produce certain sorts of ...

Byrne, Alex

232

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

233

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

Code of Federal Regulations, 2011 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...

2011-07-01

234

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

235

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

Code of Federal Regulations, 2010 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...

2010-07-01

236

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

237

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.

238

Hearing protection for miners  

SciTech Connect

A NIOSH analysis showed that at age 50 approximately 90% of coal miners have a hearing impairment, yet noise included hearing loss is 100% preventable. The article discusses requirements of the MSHA regulations, 30 CFR Part 62 - occupational noise exposure (2000) and a 2008-MSHA document describing technologically achievable and promising controls for several types of mining machinery. Hearing protection is still required for exposure to greater than 90 dBA. These are now commercially available ways to determine how much attenuation an individual gets from a given hearing protector, known as 'fit testing'. 3 refs., 1 fig., 1 tab., 1 photo.

Schulz, T. [Sperian Hearing Protection (United States)

2008-10-15

239

Mineral Requirements of Sheep.  

E-print Network

TEXAS Al A31 5-81 &6m LTURAL EXPERIMENT STATION BULLETIN NO. 232 AUGUST, 1918 -- DIVISION OF CHEMISTRY MINERAL REQUIREMENTS OF SHEEP B. YOUNGBLOOD, DIRECTOR OOUEGE STATION, BRAZOS COUNTY, TEXAIS. TEXAS AGRICULTURAL EXPERIMENT STATION... B YOUNGBLOOD M S Director E. 0. SIECKE, M. F., Forester in Charge; A' I3 CONNER 6 S' ?ice Director State Forester cLAS. A. FEL~E~ chief Clerk A. S. WARE. Secretary DIVISION OF PLANT BREEDING W T BRINK B. S. Execufioe Assistant in E. P. HUMBERT...

Fraps, G. S. (George Stronach)

1918-01-01

240

Mineral winning plough  

SciTech Connect

A mineral winning plough is disclosed, such as a coal plough, which has a plough body adapted to be moved to and fro alongside a mineral face on a plough guide. The plough body is provided with a pair of vertically-adjustable carriers, each of which is provided with floor cutters. The plough body is provided with setting means for raising and lowering the carriers into rest and working positions respectively. The setting means comprises a slide plate, and an intermediate member. The slide plate is mounted in an aperture in the plough body for limited movement relative thereto. The slide plate is attachable to a plough drive chain. The intermediate member forms a mechanical operative connection between the slide plate and the two carriers. The intermediate member is rotatably mounted on the plough body, and is positioned between the two carriers. The arrangement is such that movement of the slide plate relative to the plough body in a given direction forces one of the carriers to be lowered into its working position, and causes the other carrier to be raised into its rest position.

Hauschopp, A.; Brever, O.; Steinkuhl, B.

1983-09-13

241

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; Concistre, Antonio; Corpaci, Francesco; Tonnarini, Gianfranco; De Toma, Giorgio; Letizia, Claudio

2014-01-01

242

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

243

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

244

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

245

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

246

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

247

Mineral nutrition and bone mineralization in full-term infants.  

PubMed

Bone mineralization is an intricate and tightly regulated process. Calcium, magnesium and phosphorus are the main minerals and play a principal role in skeletal mineralization. The following conclusions can be derived from different clinical studies. The large differences in Ca/P ratio between different formulas and between formulas and human milk suggest that most healthy full-term infants can adjust to a wide range of Ca/P ratio in their diet. The differences in serum levels of mineral and of mineral-regulating hormones are rarely clinically significant and most probably reflect continued compensatory mechanisms activated in response to dietary differences to maintain these levels within clinically normal ranges. Thus in most cases, these compensatory mechanisms are sufficient to reverse both short-term and long-term consequences and to prevent clinical disease. In the case of neonatal tetany, the compensatory mechanisms are overwhelmed, resulting in clinical signs and disease. Vitamin D is known to play an essential role in bone mineralization. Our studies have shown significant differences in vitamin D status in breast-fed infants with and without vitamin D supplementation and in infants fed various "humanized" formulas, whether cow milk-based or soy protein-based. The major variables affecting bone mineralization are Ca/P ratio and mineral-regulating hormones. However, factors such as season, geography (i.e. sun exposure), race and sex may have a significant long-term influence on bone mineralization and mineral metabolism. Some biological differences such as differences in serum vitamin D metabolite level may directly effect Ca/P absorption and retention and thus bone mineralization and growth.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1435822

Steichen, J J; Koo, W W

1992-09-01

248

Rocks and Minerals Slide Show  

NSDL National Science Digital Library

This interactive slide show of common rocks and minerals allows students to choose from two sets of minerals and click on a thumbnail to see a larger photograph with a full description of the mineral including color, streak, hardness, cleavage/fracture, and chemical composition. Also included are its use and where it is found. The rocks are divided into igneous, sedimentary, and metamorphic and can be accessed in the same manner. They are described on the basis of crystal size and mineral composition as well as use.

249

Minerals Bill introduced in House  

NASA Astrophysics Data System (ADS)

A bill that aims to strengthen a national minerals policy and to establish a three-member White-House-level council to coordinate the development of this policy was introduced in the House of Representatives on April 30 by James D. Santini (D-Nev.). Entitled the National Minerals Security Act (NMSA), the legislation, if passed, also would amend tax laws to assist the mining industry to make capital investments to locate and produce strategic minerals; it would provide the means for the Secretary of the Interior to make withdrawn public lands available for mineral development; and it would create a revolving fund for the sale and purchase of strategic minerals.Santini estimates that 4 billion tons of minerals are needed annually to sustain the nation's economy. Much of the minerals are supplied by other nations, however; Santini wants to see an end to the United States' dependence on foreign countries, especially those that seem relatively unstable politically. ‘The U.S. has placed its national security in the hands of a few foreign nations,’ Santini said in a recent press conference. ‘We are heavily dependent on the region of southern Africa for 76% of our cobalt, 93% of our platinum, 48% of our chromium, and a host of other strategic and critical minerals. Without these minerals, we cannot build jet aircraft, weapons, or other military hardware vitally important to our national security.’

Richman, Barbara T.

250

Protein secondary structure prediction.  

PubMed

While the prediction of a native protein structure from sequence continues to remain a challenging problem, over the past decades computational methods have become quite successful in exploiting the mechanisms behind secondary structure formation. The great effort expended in this area has resulted in the development of a vast number of secondary structure prediction methods. Especially the combination of well-optimized/sensitive machine-learning algorithms and inclusion of homologous sequence information has led to increased prediction accuracies of up to 80%. In this chapter, we will first introduce some basic notions and provide a brief history of secondary structure prediction advances. Then a comprehensive overview of state-of-the-art prediction methods will be given. Finally, we will discuss open questions and challenges in this field and provide some practical recommendations for the user. PMID:20221928

Pirovano, Walter; Heringa, Jaap

2010-01-01

251

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

252

Secondary syphilis and HIV  

PubMed Central

Syphilis has been termed the “great mimic” due to its versatile and varied disease presentations. Dermatological findings are associated with the secondary phase of the disease and typically consist of a generalized papular eruption that can involve the palms and soles, genitals, and mucous membranes. Patients with syphilis and concomitant HIV infection may have altered presentations. We report a case of a 41-year-old HIV-positive man who presented with a papular rash of a few months' duration and was diagnosed with secondary syphilis. PMID:22275795

Dhaliwal, Shagun; Patel, Mahir

2012-01-01

253

Influence of flow properties on a structure of a mineral wool primary layer  

Microsoft Academic Search

Mineral wool primary layer formation is influenced by the aerodynamic characteristics of the blow-away airflow and the secondary surrounding airflow. The distribution of mineral wool fibres in the primary layer was determined experimentally using a computer-aided visualization method. The flow properties in the region where the primary layer is formed were analysed. Numerical simulations with experiment-based boundary conditions were performed.

Tom Bajcar; Bogdan Blagojevi?; Brane Širok; Matevž Dular

2007-01-01

254

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

255

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

256

Asymmetric mineral mining plough  

SciTech Connect

A mineral mining plough for use in asymmetric ploughing, and movable to and fro alongside a conveyor, has a plough body provided with cutter means at its two ends. A first cutter means is arranged to win material when the plough is on the uphill run (That is to say when the plough moves in the opposite direction as the conveyor). A second cutter means is arranged to win material when the plough is on the downhill run. The second cutter means is mounted on the plough body for vertical movement relative to the plough body. This enables the second cutter means to be swung out of its working position (On the downhill run) to lie in a rest position (On the uphill run) in which it is in the path of travel of the first cutter means. This vertical movement of the second cutter means results in a plough of shorter length than known asymmetric ploughs.

Hauschopp, A.; Huss, H.; Rassmann, C.; Schwolow, G.

1981-07-28

257

Longwall mineral mining installation  

SciTech Connect

A mineral mining installation comprises a longwall conveyor, a plough movable to and fro along a guide fixed to the face side of the longwall conveyor, and a drive station at one end of the longwall conveyor. The drive station includes a drive frame supporting drive means for driving the longwall conveyor. A support beam is provided at the goaf side of the drive station. The support beam extends substantially parallel to the drive frame. A floor plate extends beneath the drive frame. The goafside end portion of the floor plate is supported on the support beam by means of a lifting device, whereby the goaf-side end portion of the floor plate can be moved up and down relative to the support beam by the lifting device.

Beyer, H.; Erwien, H.; Grundken, D.; Kerklies, B.; Kumor, B.; Linke, H.; Mainusch, R.; Mohn, U.; Wleklinski, B.

1983-06-21

258

Thermodynamic properties of minerals  

USGS Publications Warehouse

In the ten years since the publication of the national Bureau of Standards comprehensive tables of thermochemical properties, by Rossini and other (1952), a very large body of modern calorimetric and equilibrium data has become available. Because of the complex interrelations among many thermochemical data and the necessity for internal consistency among these values, a complete revision of this standard reference is required. This is also true of the summaries of thermochemical data for the sulfides (Richardson and Jeffes 1952) and for the oxides (Coughlin 1954). The following tables present critically selected values for the heat and free energy of formation, the logarithm of the equilibrium constant of formation Log Kf, the entropy and the molar volume, at 298.15°K (25.0°C) and one atmosphere for minerals.

Robie, Richard A.

1962-01-01

259

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

260

Cosmetology. Secondary Curriculum Guide.  

ERIC Educational Resources Information Center

This curriculum guide is designed to offer guidelines along with supporting resources and teaching ideas from which the local secondary instructor can extract a cosmetology curriculum that meets local needs. Following an outline of the philosophy and goals underlying state and local vocational education programs in Georgia, the purpose and…

Moye, Michael D.; And Others

261

Secondary metabolism in tobacco  

Microsoft Academic Search

Tobacco has been quite well studied phytochemically, more than 2500 compounds have been identified. Here, the secondary metabolism in tobacco will be reviewed in a biosynthetic perspective. Major groups of compounds which have extensively been studied are the isoprenoids, alkaloids, cinnamoylputrescines, flavonoids, and anthocyanins. Their biosynthetic pathways and its regulation, and their occurrence in cell cultures and in intact plants

Laurentius H. Nugroho; Robert Verpoorte

2002-01-01

262

Dynamics of secondary forests  

Microsoft Academic Search

The succession of tropical secondary forests on abandoned agricultural fields has been studied since long, most often by comparing stands of different age since abandonment. These so-called chronosequence studies have yielded much insight in general patterns of succession and the constraints and conditions that affect the course of succession (shortly reviewed in chapter 1). Successional dynamics, however, are inferred rather

Breugel van M

2007-01-01

263

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

264

Secondary alkaline batteries  

SciTech Connect

This report on secondary alkaline batteries covers the overall reactions (charge/discharge characteristics), electrode structures and materials, and cell construction. The following batteries are studied, nickel oxide-cadmium, nickel oxide-iron, nickel oxide-hydrogen, nickel oxide-zinc, silver oxide-zinc, and silver oxide-cadmium, silver oxide-iron, and manganese dioxide-zinc batteries.

McBreen, J.

1984-03-01

265

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

266

Influence of abiotic stress signals on secondary metabolites in plants  

PubMed Central

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

2011-01-01

267

2006 Minerals Yearbook RARE EARTHS  

E-print Network

2006 Minerals Yearbook RARE EARTHS U.S. Department of the Interior U.S. Geological Survey May 2008 #12;RARE EARTHS--2006 60.1 In 2006, world rare-earth production was primarily from the mineral bastnäsite. Rare earths were not mined in the United States in 2006; however, the mine and plant at Mountain

268

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

269

Ore Geology and Mineral Resources  

Microsoft Academic Search

Analysis of research work on Ore geology and mineral resources, during the report period (2004-2008) reveals equitable outputs for the precious metals (Au, Ag, PGE), atomic minerals (U), and base metals (Cu, Pb, Zn), modest efforts made for Cr, Sn, W and some rare metals, with less emphasis on Fe and Mn. Again, like the previous reports, the non metals

BISWAJIT MISHRA; MIHIR DEB

270

77 FR 56273 - Conflict Minerals  

Federal Register 2010, 2011, 2012, 2013

...conflict minerals, reflects Congress's motivation to help end the human rights abuses in...allowed an issuer to stop its inquiry after learning that its necessary conflict minerals...be an incentive for issuers to avoid learning the ultimate source of the...

2012-09-12

271

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.

272

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.

Project, World I.

273

The Search for Mineral Adequacy  

Microsoft Academic Search

An intensive and comprehensively planned program of mineral exploration and discovery is the most important single factor in maintaining an adequate supply of available minerals.This program requires the services of a large staff of geologists and geophysicists adequately equipped with the essential instruments of exploration.Exploration, even tho it results in substantial discoveries, will not be adequate without the aid of

Walter H. Voskuil

1959-01-01

274

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

275

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

276

An overview of hydrodynamic studies of mineralization  

Microsoft Academic Search

Fluid flow is an integral part of hydrothermal mineralization, and its analysis and characterization constitute an important part of a mineralization model. The hydrodynamic study of mineralization deals with analyzing the driving forces, fluid pressure regimes, fluid flow rate and direction, and their relationships with localization of mineralization. This paper reviews the principles and methods of hydrodynamic studies of mineralization,

Guoxiang Chi; Chunji Xue

2011-01-01

277

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

278

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

279

Mineral composition of the modern bottom sediments of the White Sea  

NASA Astrophysics Data System (ADS)

The mineral composition of the modern bottom sediments were studied in the White Sea. The single terrigenous-mineralogical province is defined; it is characterized by the mineral association of amphibole, epidote, garnet, and pyroxene. Five regions are assigned in the White Sea in accordance with the mineral composition of the surface bottom sediments. We argue that the granite-metamorphic rock complexes of the Baltic Shield are the main source of the modern sediments in the White Sea, while the East European Craton (Russian Platform) plays a secondary role.

Gusakova, A. I.

2013-03-01

280

Contrasting exhumation P-T paths followed by high-P rocks in the northern Caribbean subduction-accretionary complex: Insights from the structural geology, microtextures and equilibrium assemblage diagrams  

NASA Astrophysics Data System (ADS)

The Río San Juan metamorphic complex exposes a segment of a high-pressure subduction-accretionary complex built during convergence between the Caribbean island arc and the North America continental margin. It is composed of accreted arc- and oceanic-derived metaigneous rocks, serpentinized peridotites and minor metasediments forming a structural pile. Combined structural geology, microtextural relations, multi-equilibrium calculations and thermodynamical modelling, together with published isotopic ages, allow reconstructing the metamorphic P-T-t paths of each nappe/unit and their links to the structural evolution. In all units of the complex, three major stages (M1 to M3) in the tectonothermal evolution have been distinguished. The M1 stage corresponds to the prograde evolution towards the pressure-peak of metamorphism under blueschist or eclogitic-facies conditions. The M2 stage is related to the main retrogressive event and is characterized by the S2-L2 fabric development in all lithologies and at all scales. The M3 stage represents continuous exhumation from ductile to ductile-brittle deformation regimes. However, the shape of the retrograde P-T path, the age of the exhumation-related D2 structures and the tectonic significance of D2 deformation are different in each structural unit. In the upper structural levels of the Jagua Clara serpentinitic-matrix mélange, the counter-clockwise P-T path of the eclogite blocks is typical of rocks exhumed in the early stages of intra-oceanic subduction zones. The clockwise P-T path obtained for the lower Cuaba unit is characterized by a strong isothermal decompression from the garnet-epidote amphibolite and eclogite-facies pressure-peak. This P-T evolution can be explained by rapid exhumation caused by extensional tectonics, in relation to a major modification of convergence conditions across the subduction zone. The P-T path also explains local syn-M2 partial melting processes, because it crosses the wet solidus for IAT mafic compositions. The P-T path obtained for the high-P Guineal Schists, with exhumation trajectory following the burial trajectory, can be related to exhumation during active subduction. This exhumation was most likely driven by a combination of underthrusting of tectonic units and erosion processes. Available geochronological data and T-t/P-t estimates reveal a Late Campanian to Maastrichtian retrograde M2 metamorphism in the lower structural units of the complex during a consistent D2 top-to-the-NE/ENE tectonic transport. A similar tectonic transport has also been recognized in the metasedimentary nappes of the Samaná complex during Eocene to earliest Miocene. These relations indicate a northeastward progradation of deformation during the successive tectonic incorporation of arc, oceanic and continental-derived terrains to the developing Caribbean subduction-accretionary complex.

Escuder-Viruete, Javier; Pérez-Estaún, Andrés

2013-02-01

281

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

282

43 CFR 8.5 - Mineral rights.  

Code of Federal Regulations, 2011 CFR

...ARMY RELATIVE TO RESERVOIR PROJECT LANDS § 8.5 Mineral rights. Mineral, oil and gas rights will not be acquired except where...thereof would interfere with project purposes, but mineral rights not acquired will be subordinated to the...

2011-10-01

283

43 CFR 8.5 - Mineral rights.  

Code of Federal Regulations, 2010 CFR

...ARMY RELATIVE TO RESERVOIR PROJECT LANDS § 8.5 Mineral rights. Mineral, oil and gas rights will not be acquired except where...thereof would interfere with project purposes, but mineral rights not acquired will be subordinated to the...

2010-10-01

284

Microtexture of Strain in electroplated copper interconnects  

SciTech Connect

The microstructure of narrow metal conductors in the electrical interconnections on IC chips has often been identified as of major importance in the reliability of these devices. The stresses and stress gradients that develop in the conductors as a result of thermal expansion differences in the materials and of electromigration at high current densities are believed to be strongly dependent on the details of the grain structure. The present work discusses new techniques based on microbeam x-ray diffraction (MBXRD) that have enabled measurement not only of the microstructure of totally encapsulated conductors but also of the local stresses in them on a micron and submicron scale. White x-rays from the Advanced Light Source were focused to a micron spot size by Kirkpatrick-Baez mirrors. The sample was stepped under the micro-beam and Laue images obtained at each sample location using a CCD area detector. Microstructure and local strain were deduced from these images. Cu lines with widths ranging from 0.8 mm to 5 mm and thickness of 1 mm were investigated. Comparisons are made between the capabilities of MBXRD and the well established techniques of broad beam XRD, electron back scatter diffraction (EBSD) and focused ion beam imagining (FIB).

Spolenak, R.; Barr, D.L.; Gross, M.E.; Evans-Lutterodt, K.; Brown, W.L.; Tamura, N.; MacDowell, A.A.; Celestre, R.S.; Padmore, H.A.; Valek, B.C.; Bravman, J.C.; Flinn, P.; Marieb, T.; Keller, R.R.; Batterman, B.W.; Patel, J.R.

2001-04-01

285

Fate of organo-mineral particles in streams: Microbial degradation by streamwater & biofilm assemblages  

NASA Astrophysics Data System (ADS)

Inland waters are of global biogeochemical importance. They receive carbon inputs of ~ 4.8 Pg C/ y of which, 12 % is buried, 18 % transported to the oceans, and 70 % supports aquatic secondary production. However, the mechanisms that determine the fate of organic matter (OM) in these systems are poorly defined. One aspect of this is the formation of organo-mineral complexes in aquatic systems and their potential as a route for OM transport and burial vs. their use as carbon (C) and nitrogen (N) sources within aquatic systems. Organo-mineral particles form by sorption of dissolved OM to freshly eroded mineral surfaces and may contribute to ecosystem-scale particulate OM fluxes. We experimentally tested the availability of mineral-sorbed OM as a C & N source for streamwater microbial assemblages and streambed biofilms. Organo-mineral particles were constructed in vitro by sorption of 13C:15N-labelled amino acids to hydrated kaolin particles, and microbial degradation of these particles compared with equivalent doses of 13C:15N-labelled free amino acids. Experiments were conducted in 120 ml mesocosms over 7 days using biofilms and water sampled from the Oberer Seebach stream (Austria). Each incubation experienced a 16:8 light:dark regime, with metabolism monitored via changes in oxygen concentrations between photoperiods. The relative fate of the organo-mineral particles was quantified by tracing the mineralization of the 13C and 15N labels and their incorporation into microbial biomass. Here we present the initial results of 13C-label mineralization, incorporation and retention within dissolved organic carbon pool. The results indicate that 514 (× 219) ?mol/ mmol of the 13:15N labeled free amino acids were mineralized over the 7-day incubations. By contrast, 186 (× 97) ?mol/ mmol of the mineral-sorbed amino acids were mineralized over a similar period. Thus, organo-mineral complexation reduced amino acid mineralization by ~ 60 %, with no differences observed between the streamwater and biofilm assemblages. Throughout the incubations, biofilms were observed to leach dissolved organic carbon (DOC). However, within the streamwater assemblage the presence of both organo-mineral particles and kaolin particles was associated with significant DOC removal (-1.7 % and -7.5 % respectively). Consequently, the study demonstrates that mineral and organo-mineral particles can limit the availability of DOC in aquatic systems, providing nucleation sites for flocculation and fresh mineral surfaces, which facilitate OM-sorption. The formation of these organo-mineral particles subsequently restricts microbial OM degradation, potentially altering the transport and facilitating the burial of OM within streams.

Hunter, W. R.; Raich, M.; Wanek, W.; Battin, T. J.

2013-12-01

286

Miner's rule revisited  

NASA Astrophysics Data System (ADS)

In the first sections, the requirements to be met by hypotheses for fatigue life prediction (including those for the crack initiation and crack propagation phases) are discussed in detail. These requirements are shown to be different for 'scientific' and for 'industrial' fatigue life prediction. Aspects with regard to an assessment of fatigue life prediction hypotheses are discussed. The last section presents the results of a large cooperative program between IABG and several automobile manufacturers, in which Miner's Rule in several versions was assessed against spectrum tests with five different actual automobile components: forged steel stub axle; forged steel stub axle, induction hardened; sheet steel welded rear axle (front wheel drive car); cast aluminum wheel; and welded sheet steel wheel. Since up to 80 components each were available, and two different, but typical, automotive stress-time histories were employed, the assessment was very thorough, avoiding many of the drawbacks of previous assessments. It is shown that damage sums to failure were usually far below 1.0; they also depended on the component in question, the aluminum wheel resulting in the lowest damage sums to failure; the damage sums to failure where always lower for a mild spectrum than for a severe one; and the influence of spectrum variation was predicted best - among the hypotheses tested - by use of a recent proposal of Zenner and Liu.

Schuetz, W.; Heuler, P.

1994-03-01

287

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

288

Secondary batteries: Recent advances  

Microsoft Academic Search

Information drawn from U.S. patents issued since July 1975 is incorporated in this discussion of secondary batteries and their commercial technology. Topics include lead-acid batteries, zinc electrodes and batteries, nickel-cadmium and other alkaline batteries, sodium-sulfur solid electrolyte batteries, lithium batteries, and other battery systems. Besides providing technical information, the book serves as a guide to U.S. patent literature, and a

R. W. Graham

1978-01-01

289

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

290

Mineral Commodity Profiles -- Rubidium  

USGS Publications Warehouse

Overview -- Rubidium is a soft, ductile, silvery-white metal that melts at 39.3 ?C. One of the alkali metals, it is positioned in group 1 (or IA) of the periodic table between potassium and cesium. Naturally occurring rubidium is slightly radioactive. Rubidium is an extremely reactive metal--it ignites spontaneously in the presence of air and decomposes water explosively, igniting the liberated hydrogen. Because of its reactivity, the metal and several of its compounds are hazardous materials, and must be stored and transported in isolation from possible reactants. Although rubidium is more abundant in the earth?s crust than copper, lead, or zinc, it forms no minerals of its own, and is, or has been, produced in small quantities as a byproduct of the processing of cesium and lithium ores taken from a few small deposits in Canada, Namibia, and Zambia. In the United States, the metal and its compounds are produced from imported raw materials by at least one company, the Cabot Corporation (Cabot, 2003). Rubidium is used interchangeably or together with cesium in many uses. Its principal application is in specialty glasses used in fiber optic telecommunication systems. Rubidium?s photoemissive properties have led to its use in night-vision devices, photoelectric cells, and photomultiplier tubes. It has several uses in medical science, such as in positron emission tomographic (PET) imaging, the treatment of epilepsy, and the ultracentrifugal separation of nucleic acids and viruses. A dozen or more other uses are known, which include use as a cocatalyst for several organic reactions and in frequency reference oscillators for telecommunications network synchronization. The market for rubidium is extremely small, amounting to 1 to 2 metric tons per year (t/yr) in the United States. World resources are vast compared with demand.

Butterman, W. C.; Reese, R. G., Jr.

2003-01-01

291

76 FR 6110 - Conflict Minerals  

Federal Register 2010, 2011, 2012, 2013

...manufactured, by that issuer to disclose in the body of its annual report whether its conflict minerals originated in the Democratic Republic of the Congo or an adjoining country. If so, that issuer...

2011-02-03

292

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

293

Highwall miners pursue thinner seams  

SciTech Connect

OEMs have implemented design changes to reduce the machine's footprint and to mine more accurately. Three manufacturers offer highwall mining systems, American Highwall Systems (AMS), ICG Addcar and Superior Highwall Miners. Latest developments in their machines are reported. 3 photos.

Fiscor, S.

2006-04-15

294

Technical Subjects in Secondary Schools  

ERIC Educational Resources Information Center

Purpose: This paper aims to examine technical education in various types of secondary schools, and suggests three levels of technical courses to be taught in secondary schools. Design/methodology/approach: The paper discusses the differences between technical schools and colleges, and vocational technical courses taught in "academic" secondary…

Howard, A. E.

2008-01-01

295

Lunar secondary craters, part K  

NASA Technical Reports Server (NTRS)

Formation of V-shaped structures surrounding the fresh Copernicus Crater and its secondary craters are reviewed, and preliminary observations of the more extensively eroded secondary crater field of Theophilus are presented. Results of laboratory simulation of secondary lunar craters to examine their effects on V-shaped ridges are also described.

Overbeck, V. R.; Morrison, R. H.; Wedekind, J.

1972-01-01

296

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

297

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

298

Geochemistry and Minerality of Wine  

NASA Astrophysics Data System (ADS)

Kaolinite (Al2Si2O5(OH)4) and gibbsite (Al(OH)3) are capable of forming in a variety of environments including anthropogenic solutions such as wine. Here, we evaluate the geochemistry of twelve white wines in order to assess the potential relationship between kaolinite/gibbsite saturation and minerality, a common wine descriptor used to express the rock and/or soil character in the aromas and flavors of wines. Aluminum and Si concentrations ranged from 228-1,281 µg L-1 and 6,583-19,746 µg L-1, respectively, where Si and Al are the only elements to demonstrate positive covariance with minerality scores. Sulfur levels varied from 25,013-167,383 µg L-1 and show the strongest negative covariance with minerality scores. However, like all of the elements studied (Al, Si, Na, Mg, S, K, Ca, and Fe), these trends were not significantly different than random at the 95% confidence level. In contrast, the relative degrees of gibbsite/kaolinite saturation display strong positive covariance with minerality scores and these trends are not random at the greater than 95% confidence level. Overall, our tasters were able to accurately assess the degree of gibbsite/kaolinite saturation amongst the twelve wines based on the objective of assessing minerality. Although the wines were undersaturated with respect to gibbsite/kaolinite, geochemical modeling reveals that increasing the wines’ pHs from ~3.3 to 4.1-4.6 (which is achievable on the palate where saliva has a pH of 7.4) results in gibbsite/kaolinite oversaturation. By considering that minerality is a function of gibbsite/kaolinite saturation and decreasing S, the origin of minerality’s taste and chemical origin in wine with known physical standards becomes increasingly crystalline.

Oze, C.; Horton, T. W.; Beaman, M.

2010-12-01

299

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.; Schafer, Cora; Krauss, Stefanie; Dunlop, John W. C.; Masic, Admir; Kerschnitzki, Michael; Zaslansky, Paul; Boesecke, Peter; Catala-Lehnen, Philip; Schinke, Thorsten; Fratzl, Peter; Jahnen-Dechent, Willi

2012-01-01

300

Defining reactive sites on hydrated mineral surfaces: Rhombohedral carbonate minerals  

NASA Astrophysics Data System (ADS)

Despite the success of surface complexation models (SCMs) to interpret the adsorptive properties of mineral surfaces, their construct is sometimes incompatible with fundamental chemical and/or physical constraints, and thus, casts doubts on the physical-chemical significance of the derived model parameters. In this paper, we address the definition of primary surface sites (i.e., adsorption units) at hydrated carbonate mineral surfaces and discuss its implications to the formulation and calibration of surface equilibria for these minerals. Given the abundance of experimental and theoretical information on the structural properties of the hydrated (10.4) cleavage calcite surface, this mineral was chosen for a detailed theoretical analysis of critical issues relevant to the definition of primary surface sites. Accordingly, a single, generic charge-neutral surface site ( tbnd CaCO 3·H 2O 0) is defined for this mineral whereupon mass-action expressions describing adsorption equilibria were formulated. The one-site scheme, analogous to previously postulated descriptions of metal oxide surfaces, allows for a simple, yet realistic, molecular representation of surface reactions and provides a generalized reference state suitable for the calculation of sorption equilibria for rhombohedral carbonate minerals via Law of Mass Action (LMA) and Gibbs Energy Minimization (GEM) approaches. The one-site scheme is extended to other rhombohedral carbonate minerals and tested against published experimental data for magnesite and dolomite in aqueous solutions. A simplified SCM based on this scheme can successfully reproduce surface charge, reasonably simulate the electrokinetic behavior of these minerals, and predict surface speciation agreeing with available spectroscopic data. According to this model, a truly amphoteric behavior is displayed by these surfaces across the pH scale but at circum-neutral pH (5.8-8.2) and relatively high ?CO 2 (?1 mM), proton/bicarbonate co-adsorption becomes important and leads to the formation of a charge-neutral H 2CO 3-like surface species which may largely account for the surface charge-buffering behavior and the relatively wide range of pH values of isoelectric points (pH iep) reported in the literature for these minerals.

Villegas-Jiménez, Adrián; Mucci, Alfonso; Pokrovsky, Oleg S.; Schott, Jacques

2009-08-01

301

Preservation of Archaeological Textiles Through Fibre Mineralization  

Microsoft Academic Search

Copper mineralized plant fibre cordage (c. 1500) found at an archaeological site was used to study fibre microstructural degradation in response to a specific burial environment and the preservation of textiles through mineralization. The process of cellulose fibre mineralization was simulated in the laboratory in an effort to prepare mineralized plant fibres under known conditions. A model for dyeing cellulosic

H. L. Chen; K. A. Jakes; D. W. Foreman

1998-01-01

302

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

303

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.

Distelhurst, Andrea

2011-10-05

304

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

305

Mineral-resource data bases  

USGS Publications Warehouse

Data bases are essential for modern scientific research. The new and exciting work being done in the Mineral Resource Program in the U.S. Geological Survey (USGS) usually begins with the question, "Where are the known deposits?" A mineral-resource data base containing this type of information and more can be useful not just to USGS scientists, but to anyone who needs such data. Users of the data bases from outside the USGS include mining and exploration companies, environmental groups, academia, other Federal Agencies, and the general public. At present, the USGS has two large mineral-resource data bases, MRDS (Mineral Resource Data System) and MAS (Minerals Availability System). MRDS was built and is mamtained by the USGS, and MAS was built and maintained by the Bureau of Mines. In 1996, after the Bureau was abolished, MAS was transferred to the USGS. The two data bases were compiled for different purposes and contain very different mformation. For instance, MAS contains information on costs, details of mining methods, and feasibility studies. MRDS has mineralogical and geologic data that are not contained in MAS. Because they are both mineral-resource data bases, however, they contain some information in common, such as location, name(s) of sites, and commodities present. Both data bases are international in scope, and both are quite large. MRDS contains over 110,000 records, while MAS has over 220,000. One reason that MAS has more records is that it contains information on smelters, mill sites, and fossil fuel sites, as well as mineral- resource sites. The USGS is working to combine the information in both data bases. This is a large undertaking that will require some years to complete. In the interim, information from both data bases will still be available

1997-01-01

306

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

307

Formation and Reactivity of Biogenic Iron Minerals  

SciTech Connect

Dissimilatory iron-reducing bacteria (DIRB) play an important role in regulating the aqueous geochemistry of iron and other metals in anaerobic, non-sulfidogenic groundwater environments; however, little work has directly assessed the cell surface electrochemistry of DIRB, or the nature of the interfacial environment around individual cells. The electrochemical properties of particulate solids are often inferred from titrations in which net surface charge is determined, assuming electroneutrality, as the difference between known added amounts of acid and base and measured proton concentration. The resultant titration curve can then be fit to a speciation model for the system to determine pKa values and site densities of reactive surface sites. Moreover, with the development of non-contact electrostatic force microscopy (EFM), it is now possible to directly inspect and quantify charge development on surfaces. A combination of acid-base titrations and EFM are being used to assess the electrochemical surface properties of the groundwater DIRB, Shewanella putrefaciens. The pKa spectra and EFM data show together that a high degree of electrochemical heterogeneity exists within the cell wall and at the cell surface of S. putrefaciens. Recognition of variations in the nature and spatial distribution of reactive sites that contribute to charge development on these bacteria implies further that the cell surface of these Fe(III)-reducing bacteria functions as a highly differentiated interfacial system capable of supporting multiple intermolecular interactions with both solutes and solids. These include surface complexation reactions involving dissolved metals, as well as adherence to mineral substrates such as hydrous ferric oxide through longer-range electrostatic interactions, and surface precipitation of secondary reduced-iron minerals.

Ferris, F. Grant

2002-06-01

308

Minerals yearbook: The mineral industry of Brazil. 1988 international review  

SciTech Connect

Brazil's gross domestic product (GDP) grew only slightly in 1988 to $277 billion at current prices. The growth rate was the smallest registered since 1983, when the rate was minus 2.8%. The economy's performance was strongly influenced by a 2% to 3% decrease in industrial production and civil construction. The mineral industry, however, countered the downward trend in the industrial sector and grew a modest 1.4%. Topics discussed in the report include the following: Government policies and programs; Production; Trade; Commodity review--Metals (Aluminum, Aluminia, and Bauxite, Columbium, Copper, Gold, Iron and Steel, Manganese, Tin, Titanium); Industrial Minerals (Gem stones, Phosphate rock, Quartz); Mineral fuels (Coal, Natural gas, Petroleum, Nuclear power); Nonmineral energy sources (Alcohol, Hydroelectric).

Ensminger, H.R.

1988-01-01

309

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

310

Phosphorus Kedge XANES Spectroscopy of Mineral Standards  

Microsoft Academic Search

Phosphorus K-edge X-ray absorption near-edge structure (XANES) spectroscopy was performed on phosphate mineral specimens including (a) twelve specimens from the apatite group covering a range of compositional variation and crystallinity; (b) six non-apatite calcium-rich phosphate minerals; (c) 15 aluminium-rich phosphate minerals; (d) ten phosphate minerals rich in either reduced iron or manganese; (e) four phosphate minerals rich in either oxidized

E Ingall; J Brandes; J Diaz; M de Jonge; D Paterson; I McNulty; C Elliott; P Northrup

2011-01-01

311

Traditional Methods for Mineral Analysis  

NASA Astrophysics Data System (ADS)

This chapter describes traditional methods for analysis of minerals involving titrimetric and colorimetric procedures, and the use of ion selective electrodes. Other traditional methods of mineral analysis include gravimetric titration (i.e., insoluble forms of minerals are precipitated, rinse, dried, and weighed) and redox reactions (i.e., mineral is part of an oxidation-reduction reaction, and product is quantitated). However, these latter two methods will not be covered because they currently are used little in the food industry. The traditional methods that will be described have maintained widespread usage in the food industry despite the development of more modern instrumentation such as atomic absorption spectroscopy and inductively coupled plasma-atomic emission spectroscopy (Chap. 24). Traditional methods generally require chemicals and equipment that are routinely available in an analytical laboratory and are within the experience of most laboratory technicians. Additionally, traditional methods often form the basis for rapid analysis kits (e.g., Quantab®; for salt determination) that are increasingly in demand. Procedures for analysis of minerals of major nutritional or food processing concern are used for illustrative purposes. For additional examples of traditional methods refer to references (1-6). Slight modifications of these traditional methods are often needed for specific foodstuffs to minimize interferences or to be in the range of analytical performance. For analytical requirements for specific foods see the Official Methods of Analysis of AOAC International (5) and related official methods (6).

Ward, Robert E.; Carpenter, Charles E.

312

CRYSTAL CHEMISTRY OF HYDROUS MINERALS  

SciTech Connect

Hydrogen has long been appreciated for its role in geological processes of the Earth's crust. However, its role in Earth's deep interior has been neglected in most geophysical thinking. Yet it is now believed that most of our planet's hydrogen may be locked up in high pressure phases of hydrous silicate minerals within the Earth's mantle. This rocky interior (approximately 7/8 of Earth's volume) is conjectured to contain 1-2 orders of magnitude more water than the more obvious oceans (the ''hydrosphere'') and atmosphere. This project is aimed at using the capability of neutron scattering from hydrogen to study the crystal chemistry and stability of hydrogen-bearing minerals at high pressures and temperatures. At the most basic level this is a study of the atomic position and hydrogen bond itself. We have conducted experimental runs on hydrous minerals under high pressure and high temperature conditions. The crystallographic structure of hydrous minerals at extreme conditions and its structural stability, and hydrogen bond at high P-T conditions are the fundamental questions to be addressed. The behavior of the hydrous minerals in the deep interior of the Earth has been discussed.

Y. ZHAO; ET AL

2001-02-01

313

Diffuse interlobular septal thickening in a coal miner.  

PubMed

Diffuse interlobular septal thickening (DIST) is an abnormality seen on high-resolution CT (HRCT) scanning of the thorax. While DIST may be present to variable extents in a number of lung conditions, it is uncommon as a predominant finding except in a few entities. This report features an ex-coal miner, thought to have coal workers' pneumoconiosis (CWP), in whom the HRCT scan showed no evidence of CWP and instead showed DIST. The patient's condition progressed incessantly towards death from severe secondary pulmonary hypertension. The case links fatal pulmonary hypertension to DIST, a pattern not previously described in coal workers. PMID:20029040

Thrumurthy, S G; Kearney, S; Sissons, M; Haider, Y

2010-01-01

314

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

315

Water concentrations in mantle peridotite minerals  

NASA Astrophysics Data System (ADS)

The concentration and distribution of volatiles in the mantle is important for constraining many key properties, including melting systematics at ridges and subduction zones. We present measurements of water concentrations in nominally anhydrous minerals from abyssal, orogenic and xenolith peridotites. Analyses of fresh and altered samples from a variety of locations are used to assess the extent to which mineral water concentrations reflect primary mantle compositions, versus diffusive loss and/or hydration due to secondary processes. Water concentrations were measured in olivine (Ol), orthopyroxene (Opx) and clinopyroxene (Cpx) by ion microprobe, using mineral specific standards and monitoring background concentrations by analysis of synthetic forsterite. Analytical reproducibility, based on 11 repeat analyses of an Ol grain, is 10%, while background H2O levels varied from 7-19 ppm. Samples include xenoliths from Pali Aike, Samoa and Spitsbergen, along with unusually fresh oceanic peridotites from the Gakkel Ridge and the Tonga Trench. In addition, samples were analyzed from the Southwest Indian Ridge (SWIR) and the Josephine Peridotite, both of which have moderate degrees of alteration. In olivine, water concentrations are <11 ppm, with the exception of Pali Aike xenoliths, which have water concentrations of 16-33 ppm. On average, peridotite Opx have 187 ppm and Cpx have 474 ppm. Pyroxenite veins from the Southwest Indian Ridge have systematically lower concentrations, with an average of 12 ppm in Opx and 55 ppm in Cpx. Water partition coefficients for Opx/Ol have an average value of 28 and Cpx/Ol of 57, significantly higher than previous estimates (e.g., Hirth and Kohlstedt, 1996). Excluding the pyroxenites, the average Cpx/Opx partition coefficient is 2, in agreement with published estimates. This suggests that Cpx and Opx preserve mantle water concentrations, whereas Ol has undergone hydrogen loss. Mineral rims have water concentrations that are within error of core concentrations. The exceptions are Ol and Cpx in Pali Aike, which have decreasing concentrations towards the rims, as previously observed by Demouchy et al. (2006). The lack of zonation can either indicate that diffusive loss or hydrothermal addition have not affected water concentrations, or that concentrations have been completely altered. We suggest that the former interpretation is correct, based on the observation that most grains are optically transparent and give consistent values for multiple analyses. In contrast, visibly altered grains yield poor quality analytical points and anomalously high concentrations, suggesting that these grains have undergone hydroxyl addition related to alteration. Assuming that pyroxenes provide accurate estimates of mantle water content, we assess the implications for mantle composition and for melting systematics. We examine the difference in water contents among different samples and the degree to which water concentrations correlate with indicators of mantle depletion, such as trace element concentrations and mineral modes. The low water content of the SWIR pyroxenite veins may indicate that they originated as garnet pyroxenites, as garnets store minimal amounts of water.

Warren, J. M.; Hauri, E. H.

2010-12-01

316

34 CFR 300.36 - Secondary school.  

...Definitions Used in This Part § 300.36 Secondary school. Secondary school means a nonprofit institutional day or residential school, including a public secondary charter school that provides secondary education, as determined under State...

2014-07-01

317

Spin Transitions in Mantle Minerals  

NASA Astrophysics Data System (ADS)

Mantle minerals at shallow depths contain iron in the high-spin electronic state. The crystal-field splitting energy increases with increasing pressure, which can favor the low-spin state. Hence, pressure-driven transitions from the high-spin to the low-spin state were proposed as early as the 1960s, and minerals in the lower mantle were suggested to contain iron in the low-spin state. Only in the past 10 years did experiments and calculations prove that iron in mantle minerals transforms from high-spin to low-spin at lower-mantle pressures. This transition has important consequences for volume, thermodynamics, and bonding. In a geophysical framework, the transition would affect the dynamics and thermochemical state of the lower mantle, through combined effects on density, elasticity, element partitioning, and transport properties. These observations provide the basis for a new paradigm of the physics and chemistry in Earth's lower(most) mantle.

Badro, James

2014-05-01

318

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

319

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

320

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

321

Geochemical processes at mineral surfaces  

SciTech Connect

This volume includes 32 papers which were presented at a symposium on geochemical processes at mineral-water interfaces in 1985 and which bring to bear on this area a very wide range of expertise. The discontinuities in properties which occur at the mineral-water interface have profound effects on the movement of naturally occurring ions. Weathering and precipitation processes control the concentrations and speciation of ions in natural waters and the movements of these within the hydrosphere; both classes of processes take place at mineral-water interfaces. After an introductory overview, the book is divided into seven major sections, each dealing with one of the aspects of the processes occurring at the mineral-water interface. Five papers deal with the physical properties of the mineral-water interface; these represent a well-balanced mix of experimental and theoretical (mathematical modeling) work. Adsorption phenomena are dealt with in another five papers; these are largely experimental in character. Ion-exchange processes are discussed in four papers, one of which addresses the use of relaxation methods to study ion exchange kinetics at the microscopic level. Spectroscopic techniques (including electron-spin resonance and Moessbauer spectroscopy) are utilized in four papers. Chemical reactions, mainly redox processes, at mineral-water interfaces are treated in four papers, one of which deals with non-biological organic reactions. Solid-solution formation and equilibria are the subjects of another set of four articles, and the last group of papers deals with the processes involved in precipitation and dissolution, including weathering.

Davis, J.A.; Hayes, K.F. (eds.)

1986-01-01

322

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

323

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

324

Organo-mineral complexation alters carbon and nitrogen cycling in stream microbial assemblages  

NASA Astrophysics Data System (ADS)

Inland waters are of global biogeochemical importance receiving carbon inputs of ~ 4.8 Pg C y-1. Of this 12 % is buried, 18 % transported to the oceans, and 70 % supports aquatic secondary production. However, the mechanisms that determine the fate of organic matter (OM) in these systems are poorly defined. One important aspect is the formation of organo-mineral complexes in aquatic systems and their potential as a route for OM transport and burial vs. microbial utilization as organic carbon (C) and nitrogen (N) sources. Organo-mineral particles form by sorption of dissolved OM to freshly eroded mineral surfaces and may contribute to ecosystem-scale particulate OM fluxes. We tested the availability of mineral-sorbed OM as a C & N source for streamwater microbial assemblages and streambed biofilms. Organo-mineral particles were constructed in vitro by sorption of 13C:15N-labelled amino acids to hydrated kaolin particles, and microbial degradation of these particles compared with equivalent doses of 13C:15N-labelled free amino acids. Experiments were conducted in 120 ml mesocosms over 7 days using biofilms and streamwater sampled from the Oberer Seebach stream (Austria), tracing assimilation and mineralization of 13C and 15N labels from mineral-sorbed and dissolved amino acids. Here we present data on the effects of organo-mineral sorption upon amino acid mineralization and its C:N stoichiometry. Organo-mineral sorption had a significant effect upon microbial activity, restricting C and N mineralization by both the biofilm and streamwater treatments. Distinct differences in community response were observed, with both dissolved and mineral-stabilized amino acids playing an enhanced role in the metabolism of the streamwater microbial community. Mineral-sorption of amino acids differentially affected C & N mineralization and reduced the C:N ratio of the dissolved amino acid pool. The present study demonstrates that organo-mineral complexes restrict microbial degradation of OM and may, consequently, alter the carbon and nitrogen cycling dynamics within aquatic ecosystems.

Hunter, William Ross; Wanek, Wolfgang; Prommer, Judith; Mooshammer, Maria; Battin, Tom

2014-05-01

325

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

326

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

327

A Film Depositional Model of Permeability for Mineral Reactions in Unsaturated Media.  

SciTech Connect

A new modeling approach based on the biofilm models of Taylor et al. (1990, Water Resources Research, 26, 2153-2159) has been developed for modeling changes in porosity and permeability in saturated porous media and implemented in an inorganic reactive transport code. Application of the film depositional models to mineral precipitation and dissolution reactions requires that calculations of mineral films be dynamically changing as a function of time dependent reaction processes. Since calculations of film thicknesses do not consider mineral density, results show that the film porosity model does not adequately describe volumetric changes in the porous medium. These effects can be included in permeability calculations by coupling the film permeability models (Mualem and Childs and Collis-George) to a volumetric model that incorporates both mineral density and reactive surface area. Model simulations demonstrate that an important difference between the biofilm and mineral film models is in the translation of changes in mineral radii to changes in pore space. Including the effect of tortuosity on pore radii changes improves the performance of the Mualem permeability model for both precipitation and dissolution. Results from simulation of simultaneous dissolution and secondary mineral precipitation provides reasonable estimates of porosity and permeability. Moreover, a comparison of experimental and simulated data show that the model yields qualitatively reasonable results for permeability changes due to solid-aqueous phase reactions.

Freedman, Vicky L.; Saripalli, Prasad; Bacon, Diana H.; Meyer, Philip D.

2004-11-15

328

Institute for Mineral and Energy  

E-print Network

and geothermal resources; · Advance the science and technology needed to lower the cost and enhance cleaner and offer insights on reducing costs and adding value. A major global advantage of IMER is the capacity to 10 per cent per annum while other minerals such as uranium and rare earth elements will become

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

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

331

High temperature mineral fiber binder  

SciTech Connect

A modified phenol formaldehyde condensate is reacted with boric acid and cured in the presence of a polyfunctional nitrogeneous compound to provide a binder for mineral wool fibers which is particularly suited for thermal insulation products intended for high temperature service.

Miedaner, P.M.

1980-11-25

332

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

333

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

334

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

335

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

336

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

337

Mineralization in the chick embryo  

Microsoft Academic Search

The chemical and physical maturation of the bone salt was studied by serial observations on its stoichiometric and infrared characteristics in avian bone from early embryonic mineral deposition to full maturity after hatching. The sequence of chemical transformations in the developing bone showed most predominantly an inverse relationship between acid phosphate and carbonate, coincident with the formation of CO3-apatite. The

Edmund D. Pellegrino; Robert M. Biltz

1972-01-01

338

Hydrazine-deproteinated bone mineral  

Microsoft Academic Search

A method is described employing 95% hydrazine which completely deproteinates and slightly dehydrates bone under nearly anhydrous conditions with only moderate heating. This method induced only minor chemical changes and no alterations in structural properties of the mineral phase. Physicochemical data are presented demonstrating that although rat bone crystals more closely resemble synthetic controls made in carbonate-rather than hydroxide-rich media,

J. D. Termine; E. D. Eanes; D. J. Greenfield; M. U. Nylen; R. A. Harper

1973-01-01

339

Rocks and Minerals: Unit Outlines  

NSDL National Science Digital Library

This article assembles free resources from the Rocks and Minerals issue of the Beyond Penguins and Polar Bears cyberzine into a unit outline based on the 5E learning cycle framework. Outlines are provided for Grades K-2 and 3-5.

Fries-Gaither, Jessica

340

Mineral Physics and Mantle Evolution  

NASA Astrophysics Data System (ADS)

Don Anderson has been a steadfast patron and constructive critic of mineral physics for more than 40 years. Although he has never actually done an experiment himself [except for perhaps some early work on ice when he was working in Greenland], he has nurtured and supported two generations of experimental mineral physicists throughout the U.S. His role and influence have been especially evident in studies of the elasticity and anelasticity of minerals and the use of such data for interpretation of seismic models of the Earth's mantle. In the 1960s, such acoustic experiments required specimens of centimeter dimensions and could achieve elevated conditions of less than 1 Gigapascal in pressure and a few hundred degrees of Celsius temperature. Today, one can perform such experiments on specimens only a fraction of a milimeter in size and reach pressures of tens of GPa and temperatures in excess of two thousand degrees C. In addition, Anderson's contributions to organized scientific endeavors have extended far beyond his founding role in IRIS to include advising on the establishment of the new Consortium for Materials Properties Research in Earth Sciences [COMPRES]. We ilustrate his remarkable contributions to mineral physics with examples of our own research, some of it done in collaboration with Anderson.

Liebermann, R. C.; Bass, J. D.; Weidner, D. J.

2003-12-01

341

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...

342

7, 40854126, 2007 Secondary organic  

E-print Network

Chemistry and Physics Discussions Secondary organic aerosol formation from m-xylene, toluene, and benzene N Secondary organic aerosol (SOA) formation from the photooxidation of m-xylene, toluene, and benzene-NOx conditions they react5 only with HO2. For all three aromatics studied (m-xylene, toluene, and benzene

Boyer, Edmond

343

Secondary Special Education Program Manual.  

ERIC Educational Resources Information Center

The purpose of this programming guide is to assist local and intermediate Michigan school districts in planning, developing, and implementing programs and services for secondary special education. The first chapter, "Delivery of Secondary Programs and Services," outlines the program's philosophy, effective program development, a program continuum,…

Lee, Frank M., Ed.

344

Metabolomics for Secondary Metabolite Research  

PubMed Central

Metabolomics, the global characterization of metabolite profiles, is becoming an increasingly powerful tool for research on secondary metabolite discovery and production. In this review we discuss examples of recent technological advances and biological applications of metabolomics in the search for chemical novelty and the engineered production of bioactive secondary metabolites. PMID:24958266

Breitling, Rainer; Ceniceros, Ana; Jankevics, Andris; Takano, Eriko

2013-01-01

345

Secondary containment options for ASTs  

SciTech Connect

Widespread publicity generated by several large overfill incidents and tank ruptures questioned the integrity of above ground petroleum storage tanks (ASTs). In response, several states have enacted requirements for the installation of adequate secondary containment at most above ground fuel tank locations. The federal government is also considering regulations for above ground fuel storage tanks. Secondary containment usually consists of a combination of dikes, liners, ponds, impoundments, curbs, ditches, sumps, receiving tanks, or other equipment capable of containing the products stored. Secondary containment facilities may contain single or multiple storage tanks. A secondary containment system should be constructed so that spills do not escape to ground or surface waters before cleanup occurs. Construction of diking and storage capacity of the diked area should be in accordance with National Fire Protection Association (NFPA) recommendations. Factors to consider when designing secondary containment systems include capacity, liner type, and spill cleanup.

McFarland, W.E.; Heintz, J.V. (Petroleum Engineer, Stearns and Wheler, Cazenovia, NY (United States))

1994-01-01

346

Clay-mineral assemblages from late Quaternary deposits on Vancouver Island, southwestern British Columbia, Canada  

NASA Astrophysics Data System (ADS)

On Vancouver Island, the Dashwood Drift, Cowichan Head Formation, Quadra Sand, and Vashon Drift were deposited during late Pleistocene glacial and interstadial periods and show large variations in clay-mineral contents partly related to changing climatic conditions. Glacial deposits are characterized by iron-rich chlorite, illite (both well crystallized), and smectite with a morphology reflecting rapid derivation from volcanic rocks. The clay mineralogy of nonglacial deposits is more complex, and is marked by the presence of vermiculite, kaolinite, halloysite, and irregular mixed-layer minerals. Nonglacial clay minerals are poorly preserved and show a higher state of alteration due to pedogenesis. Large variations in nonglacial deposits compared to glacial deposits are also due to secondary factors such as selective sorting, soil and rock source variations, differences in sedimentary environment, and diagenesis. These secondary factors do not seem to obliterate significantly the climatic imprint on the clay minerals. These studies also permit the recognition of glacially reworked sediments, the determination of relationships between two units in the same section, and the establishment of the conditions of clay-mineral formation.

Blaise, Bertrand

1989-01-01

347

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

348

Reaction of Sodium Hydroxide with Silicate Minerals.  

National Technical Information Service (NTIS)

The reactions of individual silicate minerals with caustic solution were measured over a 1-week period. These silicate minerals included: two feldspars (microcline and albite), two micas (biotite and muscovite), and three clays (chlorite, Kaolinite and mo...

S. D. Thornton

1986-01-01

349

Mineral Resources, Economic Growth, and World Population  

ERIC Educational Resources Information Center

World mineral supply and demand is discussed. The economics of future mineral availability in terms of effects on pollution, land use, energy consumption, human settlements, and the international distribution of income are emphasized. (DT)

Brooks, David B.; Andrews, P. W.

1974-01-01

350

Mineral Resources, Geological Structure and Landform Surveys  

NASA Technical Reports Server (NTRS)

Significant results are presented of ERTS-1 investigations of landform surveys, mineral resources, and geological structures. The report covers four areas: (1) mapping investigations; (2) dynamic surface processes and landforms; (3) structural elements; and (4) mineral deposits.

Short, M. N.

1973-01-01

351

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

352

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

353

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

354

Minerals yearbook, 1991: Massachusetts. Annual report  

SciTech Connect

The value of nonfuel mineral production in 1991 was $111.6 million, a decrease of $16 million compared with the 1990 value. The decrease in 1991 was largely attributable to lower sales of construction sand and gravel and crushed stone, the State's two leading mineral commodities. Other mineral commodities produced included common clay, industrial sand, dimension stone, lime, and peat. Nationally, the State ranked 41st in the production of nonfuel minerals. It ranked fifth of 34 States that produced dimension stone.

Harrison, D.K.; Sinnott, J.A.

1993-05-01

355

Mineral Supplementation of Beef Cows in Texas  

E-print Network

. National Academy of Sciences. Washington, D.C. 2. Spears, Jerry W. 1988. Trace Minerals and the Immune System. Plains Nutrition Council Symposium. Trace Minerals in Beef Cattle Nutrition. Amarillo, Texas. 3. Selenium and Copper Deficiency in Cattle. 1988.... National Academy of Sciences. Washington, D.C. 2. Spears, Jerry W. 1988. Trace Minerals and the Immune System. Plains Nutrition Council Symposium. Trace Minerals in Beef Cattle Nutrition. Amarillo, Texas. 3. Selenium and Copper Deficiency in Cattle. 1988...

Herd, Dennis B.

1997-06-04

356

Mineral transformations associated with goethite reduction by Methanosarcina barkeri  

USGS Publications Warehouse

To investigate the interaction between methanogens and iron-containing minerals in anoxic environments, we conducted batch culture experiments with Methanosarcina barkeri in a phosphate-buffered basal medium (PBBM) to bioreduce structural Fe(III) in goethite with hydrogen as the sole substrate. Fe(II) and methane concentrations were monitored over the course of the bioreduction experiments with wet chemistry and gas chromatography, respectively. Subsequent mineralogical changes were characterized with X-ray diffraction (XRD) and scanning electron microscopy (SEM). In the presence of an electron shuttle anthraquinone-2,6-disulfonate (AQDS), 30% Fe(III) in goethite (weight basis) was reduced to Fe(II). In contrast, only 2% Fe(III) (weight basis) was bioreduced in the absence of AQDS. Most of the bioproduced Fe(II) was incorporated into secondary minerals including dufr??nite and vivianite. Our data implied a dufr??nite-vivianite transformation mechanism where a metastable dufr??nite transformed to a more stable vivianite over extended time in anaerobic conditions. Methanogenesis was greatly inhibited by bioreduction of goethite Fe(III). These results have important implications for the methane flux associated with Fe(III) bioreduction and ferrous iron mineral precipitation in anaerobic soils and sediments. ?? 2011 Elsevier B.V.

Liu, D.; Wang, H.; Dong, H.; Qiu, X.; Dong, X.; Cravotta, C.A.

2011-01-01

357

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

358

Introduction to Crystallography and Mineral Crystal Systems  

NSDL National Science Digital Library

This illustrated, nine-part primer on crystallography and mineral crystal systems was developed by a professional geologist and long-time mineral collector. His objective is to bring a greater appreciation of natural mineral crystals and their forms by providing some background and understanding of the world of crystallography.

Keller, Bob

359

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.

360

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

361

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

362

Adhesion of Acidithiobacillus ferrooxidans to mineral surfaces  

Microsoft Academic Search

Direct contact mechanism in bioleaching implies prior mineral adhesion of Acidithiobacillus ferrooxidans and subsequent enzymatic attack. Prior bacterial adaptation to sulfide mineral substrates influences bacterial ferrous ion oxidation rates. It is highly beneficial to understand major biooxidation mechanisms with reference to solution- and mineral-grown cells in order to optimize bioleaching reactions.For A. ferrooxidans grown in the presence of solid substrates

Preston Devasia; K. A. Natarajan

2010-01-01

363

21 CFR 573.680 - Mineral oil.  

Code of Federal Regulations, 2010 CFR

...Drugs 6 2010-04-01 2010-04-01 false Mineral oil. 573.680 Section 573.680 Food and Drugs...OF ANIMALS Food Additive Listing § 573.680 Mineral oil. Mineral oil may be safely used in animal feed, subject to...

2010-04-01

364

36 CFR 331.17 - Minerals.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 2010-07-01 false Minerals. 331.17 Section 331.17 Parks...KENTUCKY AND INDIANA § 331.17 Minerals. All activities in connection with...or other removal or the processing of mineral resources and all uses reasonably...

2010-07-01

365

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

366

Transition to Secondary - an Experiment in a Scottish Secondary School  

ERIC Educational Resources Information Center

The attainments, attitudes, personality characteristics and friendship relations of three successive year groups of children (n254, 252 and 234) were assessed towards the end of their first term in secondary school. (Editor/RK)

Dutch, R. D.; McCall, J.

1974-01-01

367

Growth of bedding plants and poinsettias in mineral wool and mineral wool\\/peat substrates  

Microsoft Academic Search

Studies were conducted to ascertain the suitability of mineral wool (MW), either alone or in combination with sphagnum peat moss, as a substrate for potted greenhouse plants. Two types of hydrophyllic mineral wools, cleaned mineral wool (CMW) and uncleaned mineral wool (UMW), were used. Unamended CMW had a low bulk density, excellent water holding capacity, good aeration, but a high

Thomas M. Contrisciano; E. Jay Holcomb

1995-01-01

368

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

Code of Federal Regulations, 2012 CFR

...2012-04-01 2011-04-01 true Other minerals and deep-lying lead and zinc minerals. 215.25 Section 215.25 Indians...LEASES, QUAPAW AGENCY § 215.25 Other minerals and deep-lying lead and zinc minerals. Except as provided in §...

2012-04-01

369

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

...2014-04-01 2014-04-01 false Other minerals and deep-lying lead and zinc minerals. 215.25 Section 215.25 Indians...LEASES, QUAPAW AGENCY § 215.25 Other minerals and deep-lying lead and zinc minerals. Except as provided in §...

2014-04-01

370

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

Code of Federal Regulations, 2011 CFR

...2011-04-01 2011-04-01 false Other minerals and deep-lying lead and zinc minerals. 215.25 Section 215.25 Indians...LEASES, QUAPAW AGENCY § 215.25 Other minerals and deep-lying lead and zinc minerals. Except as provided in §...

2011-04-01

371

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

Code of Federal Regulations, 2013 CFR

...2013-04-01 2013-04-01 false Other minerals and deep-lying lead and zinc minerals. 215.25 Section 215.25 Indians...LEASES, QUAPAW AGENCY § 215.25 Other minerals and deep-lying lead and zinc minerals. Except as provided in §...

2013-04-01

372

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

Code of Federal Regulations, 2010 CFR

...2010-04-01 2010-04-01 false Other minerals and deep-lying lead and zinc minerals. 215.25 Section 215.25 Indians...LEASES, QUAPAW AGENCY § 215.25 Other minerals and deep-lying lead and zinc minerals. Except as provided in §...

2010-04-01

373

Mineral bridges in nacre revisited  

E-print Network

We confirm with high-resolution techniques the existence of mineral bridges between superposed nacre tablets. In the towered nacre of both gastropods and the cephalopod Nautilus there are large bridges aligned along the tower axes, corresponding to gaps (150-200 nm) in the interlamellar membranes. Gaps are produced by the interaction of the nascent tablets with a surface membrane that covers the nacre compartment. In the terraced nacre of bivalves bridges associated with elongated gaps in the interlamellar membrane (> 100 nm) have mainly been found at or close to the edges of superposed parental tablets. To explain this placement, we hypothesize that the interlamellar membrane breaks due to differences in osmotic pressure across it when the interlamellar space below becomes reduced at an advanced stage of calcification. In no cases are the minor connections between superimposed tablets (< 60 nm), earlier reported to be mineral bridges, found to be such.

Antonio G. Checa; Julyan H. E. Cartwright; Marc-Georg Willinger

2012-07-20

374

Mineral bridges in nacre revisited  

E-print Network

We confirm with high-resolution techniques the existence of mineral bridges between superposed nacre tablets. In the towered nacre of both gastropods and the cephalopod Nautilus there are large bridges aligned along the tower axes, corresponding to gaps (150-200 nm) in the interlamellar membranes. Gaps are produced by the interaction of the nascent tablets with a surface membrane that covers the nacre compartment. In the terraced nacre of bivalves bridges associated with elongated gaps in the interlamellar membrane (> 100 nm) have mainly been found at or close to the edges of superposed parental tablets. To explain this placement, we hypothesize that the interlamellar membrane breaks due to differences in osmotic pressure across it when the interlamellar space below becomes reduced at an advanced stage of calcification. In no cases are the minor connections between superimposed tablets (< 60 nm), earlier reported to be mineral bridges, found to be such.

Checa, Antonio G; Willinger, Marc-Georg

2012-01-01

375

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

376

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

377

Miners custom-make trailer  

SciTech Connect

The Maintenance Department at Glenharold Mine in Stanton, North Dakota, has developed a custom solution to a nagging problem. Employees have fabricated a flatbed trailer to haul large equipment and have saved the mine the expense of investing in a new tractor-trailer. Using Lincoln Electric's Jetweld LH-100M to fillet weld Tl steel, the miners constructed a 200-t-capacity flatbed from scraps. The trailer can haul a D-10 bulldozer or a 60 cu-yd dragline bucket.

Not Available

1987-06-01

378

Targets and Secondary Beam Extraction  

NASA Astrophysics Data System (ADS)

Several applications make use of secondary beams of particles generated by the interaction of a primary beam of particles with a target. Spallation neutrons, bremsstrahlung photon-produced neutrons, radioactive ions and neutrinos are available to users at state-of-the-art facilities worldwide. Plans for even higher secondary beam intensities place severe constraints on the design of targets. This article reports on the main targetry challenges and highlights a variety of solutions for targetry and secondary beam extraction. Issues related to target station layout, instrumentation at the beam-target interface, safety and radioprotection are also discussed.

Noah, Etam

2014-02-01

379

Mortality among Navajo uranium miners.  

PubMed Central

OBJECTIVES. To update mortality risks for Navajo uranium miners, a retrospective cohort mortality study was conducted of 757 Navajos from the cohort of Colorado Plateau uranium miners. METHODS. Vital status was followed from 1960 to 1990. Standardized mortality ratios were estimated, with combined New Mexico and Arizona non-White mortality rates used for comparison. Cox regression models were used to evaluate exposure-response relationships. RESULTS. Elevated standardized mortality ratios were found for lung cancer (3.3), tuberculosis (2.6), and pneumoconioses and other respiratory diseases (2.6). Lowered ratios were found for heart disease (0.6), circulatory disease (0.4), and liver cirrhosis (0.5). The estimated relative risk for a 5-year duration of exposure vs none was 3.7 for lung cancer, 2.1 for pneumoconioses and other respiratory diseases, and 2.0 for tuberculosis. The relative risk for lung cancer was 6.9 for the midrange of cumulative exposure to radon progeny compared with the least exposed. CONCLUSIONS. Findings were consistent with those from previous studies. Twenty-three years after their last exposure to radon progeny, these light-smoking Navajo miners continue to face excess mortality risks from lung cancer and pneumoconioses and other respiratory diseases. PMID:7702118

Roscoe, R J; Deddens, J A; Salvan, A; Schnorr, T M

1995-01-01

380

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.

Gull, Maheen; Pasek, Matthew A.

2013-01-01

381

Micro-Raman spectroscopic identification of natural mineral phases and their weathering products inside an abandoned zinc/lead mine.  

PubMed

Mining activities provide a good source of minerals of different nature. On the one hand, the primary minerals for whose formation a geological time-scale is required. On the other hand, secondary minerals, formed from removed products after the earlier weathering and alteration states. These are characteristic of the local geology and the environment context that commonly appears due to the low chemical stability of their original primary minerals. This work shows how quickly the reactions promoting secondary minerals may have taken place, due to the fact that these were found in newly formed solid materials called efflorescences. To achieve this purpose, the sampling is crucial. It was carried out in such a way that tried to guarantee that the samples collected consisted in the very top soil matter (first 2 cm depth). Thus, unlike the deeper soil, the material analysed may have been newly formed due to the interactions that they had with the place weathering agents (i.e. air oxygen, humidity, and microbial activities). Raman spectroscopy has emerged as a good and fast non-destructive technique that provides molecular information of the local mineralogy without the need of any pre-treatment of the samples. At the same time, the work looked for information on the variety of non-stable lead and-or zinc containing minerals due to the possible health and environmental risks they convey. Among the different minerals identified, 16 were of primary nature while 23 may be classified as secondary minerals, probably formed in the last decades as the result of the extractive activities. PMID:21317026

Goienaga, N; Arrieta, N; Carrero, J A; Olivares, M; Sarmiento, A; Martinez-Arkarazo, I; Fernández, L A; Madariaga, J M

2011-10-01

382

Micro-Raman spectroscopic identification of natural mineral phases and their weathering products inside an abandoned zinc/lead mine  

NASA Astrophysics Data System (ADS)

Mining activities provide a good source of minerals of different nature. On the one hand, the primary minerals for whose formation a geological time-scale is required. On the other hand, secondary minerals, formed from removed products after the earlier weathering and alteration states. These are characteristic of the local geology and the environment context that commonly appears due to the low chemical stability of their original primary minerals. This work shows how quickly the reactions promoting secondary minerals may have taken place, due to the fact that these were found in newly formed solid materials called efflorescences. To achieve this purpose, the sampling is crucial. It was carried out in such a way that tried to guarantee that the samples collected consisted in the very top soil matter (first 2 cm depth). Thus, unlike the deeper soil, the material analysed may have been newly formed due to the interactions that they had with the place weathering agents (i.e. air oxygen, humidity, and microbial activities). Raman spectroscopy has emerged as a good and fast non-destructive technique that provides molecular information of the local mineralogy without the need of any pre-treatment of the samples. At the same time, the work looked for information on the variety of non-stable lead and-or zinc containing minerals due to the possible health and environmental risks they convey. Among the different minerals identified, 16 were of primary nature while 23 may be classified as secondary minerals, probably formed in the last decades as the result of the extractive activities.

Goienaga, N.; Arrieta, N.; Carrero, J. A.; Olivares, M.; Sarmiento, A.; Martinez-Arkarazo, I.; Fernández, L. A.; Madariaga, J. M.

2011-10-01

383

25 CFR 225.22 - Approval of minerals agreements.  

...2014-04-01 2014-04-01 false Approval of minerals agreements. 225.22 Section 225.22...DEPARTMENT OF THE INTERIOR ENERGY AND MINERALS OIL AND GAS, GEOTHERMAL, AND SOLID MINERALS AGREEMENTS Minerals Agreements §...

2014-04-01

384

25 CFR 225.22 - Approval of minerals agreements.  

Code of Federal Regulations, 2013 CFR

...2013-04-01 2013-04-01 false Approval of minerals agreements. 225.22 Section 225.22...DEPARTMENT OF THE INTERIOR ENERGY AND MINERALS OIL AND GAS, GEOTHERMAL, AND SOLID MINERALS AGREEMENTS Minerals Agreements §...

2013-04-01

385

25 CFR 225.22 - Approval of minerals agreements.  

Code of Federal Regulations, 2012 CFR

...2012-04-01 2011-04-01 true Approval of minerals agreements. 225.22 Section 225.22...DEPARTMENT OF THE INTERIOR ENERGY AND MINERALS OIL AND GAS, GEOTHERMAL, AND SOLID MINERALS AGREEMENTS Minerals Agreements §...

2012-04-01

386

25 CFR 225.33 - Assignment of minerals agreements.  

Code of Federal Regulations, 2012 CFR

...2012-04-01 2011-04-01 true Assignment of minerals agreements. 225.33 Section 225.33...DEPARTMENT OF THE INTERIOR ENERGY AND MINERALS OIL AND GAS, GEOTHERMAL, AND SOLID MINERALS AGREEMENTS Minerals Agreements §...

2012-04-01

387

25 CFR 225.33 - Assignment of minerals agreements.  

Code of Federal Regulations, 2013 CFR

... 2013-04-01 false Assignment of minerals agreements. 225.33 Section 225.33...DEPARTMENT OF THE INTERIOR ENERGY AND MINERALS OIL AND GAS, GEOTHERMAL, AND SOLID MINERALS AGREEMENTS Minerals Agreements §...

2013-04-01

388

25 CFR 225.33 - Assignment of minerals agreements.  

... 2014-04-01 false Assignment of minerals agreements. 225.33 Section 225.33...DEPARTMENT OF THE INTERIOR ENERGY AND MINERALS OIL AND GAS, GEOTHERMAL, AND SOLID MINERALS AGREEMENTS Minerals Agreements §...

2014-04-01

389

25 CFR 225.22 - Approval of minerals agreements.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 2010-04-01 false Approval of minerals agreements. 225.22 Section 225.22...DEPARTMENT OF THE INTERIOR ENERGY AND MINERALS OIL AND GAS, GEOTHERMAL, AND SOLID MINERALS AGREEMENTS Minerals Agreements §...

2010-04-01

390

25 CFR 225.33 - Assignment of minerals agreements.  

Code of Federal Regulations, 2010 CFR

... 2010-04-01 false Assignment of minerals agreements. 225.33 Section 225.33...DEPARTMENT OF THE INTERIOR ENERGY AND MINERALS OIL AND GAS, GEOTHERMAL, AND SOLID MINERALS AGREEMENTS Minerals Agreements §...

2010-04-01

391

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

392

25 CFR 225.22 - Approval of minerals agreements.  

Code of Federal Regulations, 2011 CFR

...2011-04-01 2011-04-01 false Approval of minerals agreements. 225.22 Section 225.22...DEPARTMENT OF THE INTERIOR ENERGY AND MINERALS OIL AND GAS, GEOTHERMAL, AND SOLID MINERALS AGREEMENTS Minerals Agreements §...

2011-04-01

393

25 CFR 225.33 - Assignment of minerals agreements.  

Code of Federal Regulations, 2011 CFR

... 2011-04-01 false Assignment of minerals agreements. 225.33 Section 225.33...DEPARTMENT OF THE INTERIOR ENERGY AND MINERALS OIL AND GAS, GEOTHERMAL, AND SOLID MINERALS AGREEMENTS Minerals Agreements §...

2011-04-01

394

JWST Secondary Mirror Deploy Timelapse  

NASA Video Gallery

Setting up NASA's James Webb Space Telescope's secondary mirror in space will require special arms that resemble a tripod that was recently demonstrated in a NASA cleanroom. TRT: 1:25 / Credit: NAS...

395

Analysis of some elements in primary enamel during postnatal mineralization.  

PubMed

The primary teeth start to mineralize in utero and continue development and maturation during the first year of life.The aim of this study was to investigate the concentrations of some elements, C, F, Na, Mg, Cl, K and Sr, by secondary ion mass spectrometry (SIMS) in human primary incisors at different stages of mineralization.The teeth derived from an autopsy material from children who had died in sudden infant death.The buccal enamel of specimens from the ages 1, 2, 3, 4, 6 and 19 months, respectively, was analyzed. It was evident that posteruptive effects play an important role in composition of the outermost parts of the enamel. Before the tooth erupts, the concentrations of the elements vary with the maturation grade of the mineralization in the enamel. Sodium was the element with the highest concentration of the measured elements and chlorine was the element of lowest concentration.The 19 month old specimen, considered as the only mature and erupted tooth, showed to differ from the other specimens.The concentration of fluorine, in the 19 month old specimen's outermost surface, is readily seen higher compared with the other specimens at this depth zone. In the 19 month old specimen the concentration of carbon is lower. Potassium, sodium and chlorine have higher concentrations, in general, in the 19 month old specimen compared with the immature specimens. The thickness of the enamel during mineralization was calculated from data from SIMS.The thickness of the buccal enamel of primary incisors seemed to be fully developed between 3-4 months after birth, reaching a thickness of 350-400 microm. PMID:19728580

Sabel, Nina; Klinberg, Gunilla; Nietzsche, Sandor; Robertson, Agneta; Odelius, Hans; Norén, Jörgen G

2009-01-01

396

Electrical conductivity of mantle minerals  

NASA Astrophysics Data System (ADS)

Electrical conductivity of mantle minerals Deep electrical conductivity profiles can provide constraints on the thermal and chemical state of the mantle. Especially, electrical conductivity is very sensitive to small amount of hydrogen and iron contents in minerals. Accurate knowledge of electrical conductivity of mantle minerals is needed to constrain water and/or iron contents in the mantle as a function of depth. We have investigated the electrical properties of olivine, wadsleyite, ringwoodite and majorite, which are main constituent minerals of the upper mantle by in situ electrical conductivity measurement using multianvil apparatus. The starting materials were olivine (Fo91) for olivine, wadsleyite and ringwoodite, and glass powder with composition of pyrolite minus olivine for majorite, respectively. In most cases, molybdenum disk electrode connecting to the sample was used as an oxygen buffer media, whose oxygen fugacity is close to Fe-FeO buffer. The electrical conductivities of the samples were measured at various pressures from 3 and 20 GPa and temperatures up to 2000K at low frequencies ranging from 0.01 to 0.1 Hz. For all the dry samples, electrical conductivity displays Arrhenian behavior over the entire investigated temperature range. In the high temperature range above 1700K, activation energies (more than 1.5 eV) tend to be higher than those in the lower temperature range (less than 1.5 eV). The absolute values of electrical conductivity (S/m) for each mineral are very similar to each other. From these measurements we noted that the electrical conductivities of dry olivine, wadsleyite and ringwoodite (less than 100 wt. ppm of water) are much lower than those previously reported (e.g., Xu et al., 1998). While conductivities of samples with certain amounts of hydrogen are comparable to that of the dry one, conductivity increases with increasing hydrogen concentrations. Activation energies of hydrogen-bearing nominally anhydrous minerals we measured decreases with increasing hydrogen concentration from nearly 1 to 0.5 eV. Using our results, we can estimate the electrical conductivity profile of the upper mantle. Comparing the reference model of Utada et al. (2003), our modeling demonstrates that the electrical conductivity of the upper mantle up to 410km discontinuity (i.e. olivine stability field) is close to that of dry olivine, whereas the electrical conductivities of dry wadsleyite, ringwoodite and majorite are much lower than the reference model. Therefore, a presence of hydrogen in their minerals or the other conductors is required to explain the high conductivity in the transition zone. References Xu, Y., Poe, B. T., Shankland, T. J. & Rubie, D. C., Electrical conductivity of olivine, wadsleyite and ringwoodite under upper-mantle conditions. Science 280, 1415-1418 (1998). Utada, H., Koyama, T., Shimizu, H. & Chave, A. D., A semi-global reference model for electrical conductivity in the mid-mantle beneath the north Pacific region. Geophys. Res. Lett. 30, 1194, doi:10.1029/2002GL016902 (2003).

Yoshino, T.; Manthilake, G.; Nishi, M.; Katsura, T.

2006-12-01

397

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

398

Systems Genetics of Mineral Metabolism123  

PubMed Central

Minerals are essential and toxic elements that have an impact on human health. Although we have learned a tremendous amount about the metabolism, biological roles, and health effects of minerals with the tools of biochemistry, cell biology, and molecular genetics, there are gaps in our knowledge of mineral biology that will benefit from new approaches. Forward genetics, whereby variations in phenotypes are mapped to natural genetic variation in the genome, has been successfully used to increase our understanding of many biologically important traits but has not yet been used extensively for mineral metabolism. In addition, the well-appreciated existence of interactions between minerals justifies a broader, systems approach to the study of mineral metabolism, i.e., ionomics. This short review will explain the value of forward genetics and ionomics as tools for exploring mammalian mineral metabolism. PMID:21270371

Fleet, James C.; Replogle, Rebecca; Salt, David E.

2011-01-01

399

Osteochondroma and secondary synovial osteochondromatosis  

Microsoft Academic Search

Secondary synovial osteochondromatosis (SOC) is a rare disorder caused by a variety of joint disorders. Two unusual cases\\u000a of secondary SOC are presented. The first patient is a 43-year-old man with extensive SOC developing within a bursa surrounding\\u000a an osteochondroma of the pubic bone. The second patient is a 23-year-old man who developed florid and progressive SOC of his\\u000a hip

W. C. G. Peh; Tony W. H. Shek; A. Mark Davies; Jimmy W. K. Wong; Eric P. Chien

1999-01-01

400

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

401

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

402

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

403

Lincoln County Secondary Data Analysis  

E-print Network

+ Male Female Male Female Male Female prevalence (Heart Attack) 5.0% 4.1% 6.0% All Sites Cancer 466.5 (Region 5) 455.5 543.2 1 Community, Sanders, Lake, Mineral, Missoula, and Ravalli Chronic Disease Hospitalization Rates County

Maxwell, Bruce D.

404

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

405

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

NASA Astrophysics Data System (ADS)

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.

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

2014-10-01

406

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

407

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

408

Reactivity of Sulfide Mineral Surfaces  

SciTech Connect

In the preceding chapter, the fundamental nature of sulfide mineral surfaces has been discussed, and the understanding we have of the ways in which the surface differs from a simple truncation of the bulk crystal structure reviewed. This naturally leads on to considering our understanding of sulfide surface chemistry, in the sense of how sulfide surfaces interact and react, particularly with gases and liquids. As noted elsewhere in this volume, research on sulfide mineral surfaces and surface reactivity is a relatively recent concern of mineralogists and geochemists, partly prompted by the availability of new imaging and spectroscopic methods, powerful computers and new computer algorithms. There has been a significantly longer history of sulfide mineral surface research associated with technologists working with, or within, the mining industry. Here, electrochemical methods, sometimes combined with analytical and spectroscopic techniques, have been used to probe surface chemistry. The motivation for this work has been to gain a better understanding of the controls of leaching reactions used to dissolve out metals from ores, or to understand the chemistry of the froth flotation systems used in concentrating the valuable (usually sulfide) minerals prior to metal extraction. The need for improved metal extraction technologies is still a major motivation for research on sulfide surfaces, but in the last couple of decades, new concerns have become important drivers for such work. In particular, much greater awareness of the negative environmental impact of acid and toxic metal-bearing waters derived from breakdown of sulfide minerals at former mining operations has prompted research on oxidation reactions, and on sorption of metals at sulfide surfaces. At the interface between fundamental geochemistry and industrial chemistry, the role of sulfide substrates in catalysis, and in the self-assembly and functionalization of organic molecules, has become an area of significant interest. Such work ranges in its application from the development of new industrial processes, to fundamental questions of the possible role of sulfide surfaces in catalyzing the formation of the complex organic molecules leading to the emergence of life on Earth. In this chapter, we aim to provide an overview of current understanding of sulfide surface chemistry. The size of this research field is already such that it is impossible to discuss all of the published work, but key examples are considered and readers directed to the main literature sources. The chapter begins with some examples of reaction with gaseous species (O2, H2O, H2S, CH3OH) as these are the most accessible in terms of understanding reactivity at the molecular scale. The very important oxidation and related electron transfer reactions, in both air and aqueous solution, are then considered before considering examples of catalysis and functionalization/self-assembly and interaction with organic molecules. In the final section, sorption of metal ions onto sulfide mineral surfaces is discussed before a few words concerning the future outlook for research in this entire area.

Rosso, Kevin M.; Vaughan, David J.

2006-08-01

409

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

410

Fate of Cd during microbial Fe(III) mineral reduction by a novel and Cd-tolerant Geobacter species.  

PubMed

Fe(III) (oxyhydr)oxides affect the mobility of contaminants in the environment by providing reactive surfaces for sorption. This includes the toxic metal cadmium (Cd), which prevails in agricultural soils and is taken up by crops. Fe(III)-reducing bacteria can mobilize such contaminants by Fe(III) mineral dissolution or immobilize them by sorption to or coprecipitation with secondary Fe minerals. To date, not much is known about the fate of Fe(III) mineral-associated Cd during microbial Fe(III) reduction. Here, we describe the isolation of a new Geobacter sp. strain Cd1 from a Cd-contaminated field site, where the strain accounts for 10(4) cells g(-1) dry soil. Strain Cd1 reduces the poorly crystalline Fe(III) oxyhydroxide ferrihydrite in the presence of at least up to 112 mg Cd L(-1). During initial microbial reduction of Cd-loaded ferrihydrite, sorbed Cd was mobilized. However, during continuous microbial Fe(III) reduction, Cd was immobilized by sorption to and/or coprecipitation within newly formed secondary minerals that contained Ca, Fe, and carbonate, implying the formation of an otavite-siderite-calcite (CdCO3-FeCO3-CaCO3) mixed mineral phase. Our data shows that microbially mediated turnover of Fe minerals affects the mobility of Cd in soils, potentially altering the dynamics of Cd uptake into food or phyto-remediating plants. PMID:24274146

Muehe, E Marie; Obst, Martin; Hitchcock, Adam; Tyliszczak, Tolek; Behrens, Sebastian; Schröder, Christian; Byrne, James M; Michel, F Marc; Krämer, Ute; Kappler, Andreas

2013-12-17

411

Re-defining normal: bone mineral density in elite female athletes  

Microsoft Academic Search

BackgroundCollege age female athletes are susceptible to decreased bone mineral density (BMD) which puts them at an elevated risk for poor bone health in the future.ObjectiveThe primary purpose of this study was to compare site-specific and total body BMD of college-age female athletes across sports of varying impact level. Secondary objectives included (1) evaluating the relationship between BMD and menstrual,

P Cutti; R Steele; I Shrier; D Garza; W Meeuwisse; L Bacharach; G Matheson

2011-01-01

412

Magnetic beneficiation of highland and hi-Ti mare soils - Rock, mineral, and glassy components  

NASA Technical Reports Server (NTRS)

The exploitation of lunar soil can provide valuable raw materials for in situ resource utilization at a lunar base. A study of magnetic characterization was undertaken of three mare and two highland soils obtained from NASA. Beneficiation of mare and highland soils by sizing and magnetic separation can effectively concentrate the important components of the soils (e.g., ilmenite, native Fe, plagioclase, and aggluminates). As a soil matures and the impact melts consume additional minerals and rocks, the modal percentage of the minerals will decrease. The 'normative' percentage will become much greater than the modal percentage. Therefore, greater efficiency of separation can be realized with the proper selection of maturity of the soil, as well as by secondary grinding to further liberate specific minerals from lithic fragments (e.g., ilmenite and plagioclase).

Taylor, Lawrence A.; Oder, Robin R.

1990-01-01

413

Influence of flow properties on a structure of a mineral wool primary layer  

SciTech Connect

Mineral wool primary layer formation is influenced by the aerodynamic characteristics of the blow-away airflow and the secondary surrounding airflow. The distribution of mineral wool fibres in the primary layer was determined experimentally using a computer-aided visualization method. The flow properties in the region where the primary layer is formed were analysed. Numerical simulations with experiment-based boundary conditions were performed. The numerically obtained profile of mineral wool thickness at the collection chamber outlet agreed with the results of the experiment. Presented numerical model confirms that the forming of the primary layer is significantly dependent on local aerodynamic characteristic of the airflow in the collection chamber. Interaction between the local anomalies on the forming layer and the corresponding aerodynamic effects in the surrounding region was also analysed. (author)

Bajcar, Tom; Blagojevic, Bogdan; Sirok, Brane; Dular, Matevz [Faculty of Mechanical Engineering, University of Ljubljana, Askerceva 6, SI - 1000 Ljubljana (Slovenia)

2007-11-15

414

Volatility in the lunar crust: Trace element analyses of lunar minerals by PIXE proton microprobe  

NASA Technical Reports Server (NTRS)

In situ determination of mineral compositions using microbeam techniques can characterize magma compositions through mineral-melt partitioning, and be used to investigate fine-grained or rare phases which cannot be extracted for analysis. Abundances of Fe, Mn, Sr, Ga, Zr, Y, Nb, Zn, Cu, Ni, Se, and Sb were determined for various mineral phases in a small number of lunar highlands rocks using the PIXE proton microprobe. Sr/Ga ratios of plagioclase and Mn/Zn ratios of mafic silicates show that the ferroan anorthosites and Mg-suite cumulates are depleted in volatile lithophile elements to about the same degree compared with chondrites and the Earth. This links the entire lunar crust to common processes or source compositions. In contrast, secondary sulfides in Descartes breccia clasts are enriched in chalcophile elements such as Cu, Zn, Ni, Se, and Sb, and represent a potential resource in the lunar highlands.

Norman, M. D.; Griffin, W. L.; Ryan, C. G.

1993-01-01

415

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

416

Validity of hair mineral testing.  

PubMed

The variance of testing was compared between the College of American Pathologists clinical survey and that of a recent review about hair mineral testing. The review suggested that the accuracy of hair mineral testing was unreliable. In general, there was a greater range of variance in the College of American Pathologists testing results. These latter results are based on laboratory testing and are used as a "yardstick" to determine if a laboratory passes or fails that analyte and are considered a "gold standard." An extract, which resulted from a method that avoided the washing step, was compared among five laboratories. Very good precision resulted, indicating that the varied washing steps used by the laboratories in a recent review were probably the source of much variance. Analysis of hair analysis seemed to yield important information in several historical or forensic cases involving Ludwig von Beethoven, Napoleon Bonaparte, ex-US-presidents Zachary Taylor and Andrew Jackson, and Charles Hall, an Arctic explorer. Several elements that were reviewed, including arsenic, cadmium, cobalt, germanium, lead, lithium, manganese, mercury, nickel, and thallium, showed relationships between body burden, dosage, and exposure or toxicity. Evidence of toxicity could not be found by measuring hair aluminum or vanadium. Chromium, selenium, and zinc seemed to have nutritional value. Ratios of hair elements with clinical importance could not be found. PMID:12117220

Shamberger, R J

2002-01-01

417

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

418

Boron isotopic compositions of some boron minerals  

NASA Astrophysics Data System (ADS)

Boron minerals that have different structural formulae but are supposed to have the same geologic origin have been collected and analyzed for the 11B /10B isotopic ratio. It has been reconfirmed that minerals of marine origin have higher 11B /10B ratios than those of nonmarine origin. It has been found that the sequence of decreasing 11B /10B values among the minerals with the same geologic origin is; borax, tincal, kernite (Na borates) > ulexite ( Na/Ca borate) > colemanite, iyoite, meyerhofferite (Ca borates). This sequence is explainable on the basis of the difference in crystal structure among the minerals. That is, minerals with higher BO 3/BO 4 ratios, (the ratio of the number of the BO 3 triangle units to the number of the BO 4 tetrahedron units in the structural formula of a mineral) have higher 11B /10B ratios.

Oi, Takao; Nomura, Masao; Musashi, Masaaki; Ossaka, Tomoko; Okamoto, Makoto; Kakihana, Hidetake

1989-12-01

419

Mortality from stomach cancer in Ontario miners.  

PubMed Central

An excess of mortality from stomach cancer has been found in Ontario gold miners (observed (obs) 104, standardised mortality ratio (SMR) 152, 95% confidence interval (95% CI) 125-185) and no excess of stomach cancer could be detected in other miners in Ontario (obs 74, SMR 102, 95% CI 80-128). The excess of stomach cancer appeared five to 19 years after the miners began gold mining in Ontario. In that interval, similar patterns of excess mortality from stomach cancer were found in miners born in north America (obs 14, SMR 268, CI 147-450) and in miners born outside north America (obs 12, SMR 280, 95% CI 145-489). Twenty or more years after the miners began mining gold, an excess of mortality from stomach cancer was found in gold miners born outside of north American (obs 41, SMR 160, 95% CI 115-218) but not in gold miners born in north America (obs 37, SMR 113, 95% CI 80-156). The excess of stomach cancer in gold miners under the age of 60 (obs 45, SMR 167, 95% CI 122-223) seems larger than the excess in gold miners between the ages of 60 and 74 (obs 59, SMR 143, 95% CI 109-184). Exposures to arsenic, chromium, mineral fibre, diesel emissions, and aluminium powder were considered as possible explanations of the excess of stomach cancer in Ontario gold miners. Exposure to diesel emissions and aluminium powder was rejected as gold miners and uranium miners were exposed to both agents but an excess of stomach cancer was noted only in gold miners. The association between the excess of stomach cancer and the time since the miner began mining gold suggested that duration of exposure to dust in gold mines ought to be weighted according to the time since the exposure to dust occurred and that an appropriate time weighting function would be one in the interval five to 19 years after each year of exposure to dust and zero otherwise. A statistically significant association between the relative risk of mortality from stomach cancer and the time weighted duration of exposure to dust in gold mines was found in miners under the age of 60. Time weighted indices of exposure to chromium and arsenic were formed for each gold miner by time weighting the product of the duration of exposure to dust in a gold mine and the percentages of arsenic and chromium in rocks in that gold mine. Exposure to mineral fibre was measured in terms of the time weighted duration of employment in those gold mines that contain mineral fibre. A statistically significant association between the excess of stomach cancer in gold miners under the age of 60 and the time weighted index of exposure to chromium occurred and not association was found between the excess of stomach cancer and either the time weighted duration of employment in mines containing mineral fibre. The excess of stomach cancer in gold miners under the age of 60 was better associated with the time weighted index of exposure to chromium than to the time weighted duration of exposure to dust in gold mines. Although the number of cases of gastric cancer that were classified according to the system of Lauren was small, the data suggest that for miners under the age of 60, exposure to chromium is associated with the development of the intestinal rather than the diffuse type of gastric cancer. PMID:8435344

Kusiak, R A; Ritchie, A C; Springer, J; Muller, J

1993-01-01

420

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

421

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...

422

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...

423

Secondary mineral formation associated with respiration of nontronite, NAu-1 by iron reducing bacteria  

PubMed Central

Experimental batch and miscible-flow cultures were studied in order to determine the mechanistic pathways of microbial Fe(III) respiration in ferruginous smectite clay, NAu-1. The primary purpose was to resolve if alteration of smectite and release of Fe precedes microbial respiration. Alteration of NAu-1, represented by the morphological and mineralogical changes, occurred regardless of the extent of microbial Fe(III) reduction in all of our experimental systems, including those that contained heat-killed bacteria and those in which O2, rather than Fe(III), was the primary terminal electron acceptor. The solid alteration products observed under transmission electron microscopy included poorly crystalline smectite with diffuse electron diffraction signals, discrete grains of Fe-free amorphous aluminosilicate with increased Al/Si ratio, Fe-rich grains, and amorphous Si globules in the immediate vicinity of bacterial cells and extracellular polymeric substances. In reducing systems, Fe was also found as siderite. The small amount of Fe partitioned to the aqueous phase was primarily in the form of dissolved Fe(III) species even in the systems in which Fe(III) was the primary terminal electron acceptor for microbial respiration. From these observations, we conclude that microbial respiration of Fe(III) in our laboratory systems proceeded through the following: (1) alteration of NAu-1 and concurrent release of Fe(III) from the octahedral sheets of NAu-1; and (2) subsequent microbial respiration of Fe(III).

O'Reilly, S Erin; Watkins, Janet; Furukawa, Yoko

2005-01-01

424

[Methylphenidate and secondary Raynaud's phenomenon].  

PubMed

Raynaud's phenomenon is a clinical disease characterized by episodic attacks of vasoconstriction of the arteries and arterioles of the extremities such as fingers and toes, sometimes the ears and nose, in response to cold or emotional stimuli. A classic attack is the pallor of the distal extremity, followed by cyanosis and redness, accompanied by paresthesia, usually as heat. When it occurs without apparent cause is called primary Raynaud's phenomenon. When associated with other disease, is called secondary Raynaud's phenomenon. The secondary table is associated with increased frequency of rheumatic diseases of collagen. They can also present certain drugs that cause vasoconstriction, such as ergotamine, beta-adrenergic antagonists, contraception and sympathomimetic drugs. Regarding the latter, we present a case of Raynaud's phenomenon secondary to methylphenidate in a 14 years. PMID:24034762

Iglesias Otero, M; Portela Romero, M; Bugarín González, R; Ventura Victoria, M A

2013-09-01

425

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

426

Secondary erythromelalgia - a case report -.  

PubMed

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; Cho, Joung Goo

2013-07-01

427

Diamagnetic Orientation of Clay Mineral Grains  

Microsoft Academic Search

The orientations of diamagnetic mineral grains in magnetic fields are observed, for the first time, in suspensions of clay minerals such as talc, kaolinite and sericite. The minerals consist of two-dimensional crystal layers which produce intrinsic diamagnetic anisotropy, \\\\varDeltachi, in the unit cell. In the case of talc suspension with the average diameter of phi 2.4 mum and the thickness

Chiaki Uyeda; Tetsuya Takeuchi; Akio Yamagishi; Muneyuki Date

1991-01-01

428

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

429

Correlation of ameloblastin with enamel mineral content.  

PubMed

In enamel formation, the deposition of minerals as crystallites starts when the mineralization front first forms at the start of the secretory stage. During maturation, the enamel layer accumulates significant amounts of new mineral as the crystallites grow in volume. Inversely related to mineral gain is loss of protein and water from the forming enamel. Both ameloblastin (Ambn) and enamelin are essential components for formation of a functional enamel layer. The aim of this study was to quantify the proportion of mineral and non-mineral material present in developing enamel relative to Ambn concentration using Ambn mutant mice mated with others overexpressing full-length Ambn from the mouse amelogenin promoter at lower (+), similar (++) or higher (+++) concentration than normal. Mandibular incisors (age: 7 weeks, n?=?8) were imaged by micro-computed tomography and the enamel was analyzed from the apical region to the incisal edge in sequential 1.0?mm volumes of interest. Mineral density was determined using a series of hydroxyapatite (HA) phantoms to calibrate enamel density measurements. At the site where the mandibular incisor emerged into the oral cavity, the enamel volume, mineral weight, and mineral density were reduced when Tg Ambn was expressed at lower or higher levels than normal. While in wild-type the % mineral was >95%, it was negligible in Ambn-/-, 22.3% in Ambn-/-, Tg(+), 75.4% in Ambn-/-, Tg(++), and 45.2% in Ambn-/-, Tg(+++). These results document that the deposition of mineral and removal of non-mineral components are both very sensitive to expressed Ambn concentrations. PMID:25158178

Teepe, John D; Schmitz, James E; Hu, Yuanyuan; Yamada, Yoshihiko; Fajardo, Roberto J; Smith, Charles E; Chun, Yong-Hee P

2014-08-01

430

The arsenic content of bottled mineral waters  

Microsoft Academic Search

The arsenic levels of 23 mineral waters on sale to the public in the United Kingdom were measured. The arsenic content of most waters was below 1 µg L-1 but the statutory limits of 50 ug L-1 for natural mineral waters and 100 µg L-1 for non-alcoholic beverages were exceeded by the French mineral water, Vichy Célestins (220 ug L-1).

John G. Farmer; Linda R. Johnson

1985-01-01

431

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

432

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.

433

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

434

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

435

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

436

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

437

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

438

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

439

Mineral minimization in nature's alternative teeth  

E-print Network

REVIEW Mineral minimization in nature's alternative teeth Christopher C. Broomell1, , Rashda K, particularly teeth, have been extensively studied in structural, chemical, mechanical and clinical detail

Zok, Frank

440

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.

441

Minerals yearbook, 1990: Massachusetts. Annual report  

SciTech Connect

The value of nonfuel mineral production in 1990 was $127.5 million, a decrease of $16.6 million compared with the 1989 value. The combined value of crushed stone and construction sand and gravel, the State's two leading mineral commodities, accounted for 83% of the value. In 1990, the State ranked eighth among 34 States that produced dimension stone. Other commodities produced included common clay, industrial sand, lime, and peat. Industrial minerals processed or manufactured in the State included abrasives, graphite, gypsum, perlite, and vermiculite. The report presents statistical information on the state's mineral industries.

Harrison, D.K.; Sinnott, J.A.

1992-09-01

442