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Sample records for secondary mineral microtextures

  1. Heavy Minerals in Palaeotsunami Deposits: Assemblages, Spatial Distribution and Microtextural Imprints

    NASA Astrophysics Data System (ADS)

    Costa, P. J.; Andrade, C.; Cascalho, J.; Dawson, A. G.; Freitas, M. C.; Dawson, S.; Mahaney, W. C.

    2013-12-01

    The sedimentological record provides a database useful to characterize and evaluate recurrence of tsunamis, which contributes to assessing the vulnerability of any coastal area to this natural hazard. Thus, the enhancement of our ability to recognize signatures specific of tsunami activity imprinted in coastal sediments is of unquestionable interest. The aim of this study is to discuss and further contribute to the improvement of the characterization of (palaeo)tsunami deposits, and of their source materials. With that purpose the vertical and horizontal distribution of heavy mineral (HM) assemblages in sand-sized tsunamigenic deposits from six locations exhibiting a varied suite of coastal contexts and corresponding to three inundation events -(8200yrs BP - Scotland, 1500yrs BP - Scotland, AD 1755 - Portugal) were studied. In general, results from paleotsunami sediments show that site-specific effects prevent 'blind' extrapolations; instead, the bulk of the HM assemblages reflect local specificities related with the regional geology. In the Portuguese sediments (Martinhal, Boca do Rio and Salgados) ca. 90% of the non-opaque HM population consists of tourmaline, andalusite and staurolite, whereas amphiboles are dominant (> 90% of the assemblage) in the Scottish sediments (Scasta Voe, Basta Voe and Whale Firth). Principal Components Analyses revealed that the first 2 components explain more than 2/3 of the total variance found in each site. Horizontal and vertical variations in the HM were observed and especially in the heavier mineral species. Although, in some of the studied cases, the deposit was macroscopically massive, data on HM allowed the distinction of backwash layer(s), related with incorporation of inland materials. In what concerns sources, results indicate that palaeotsunami sediments share fewer compositional similarities with present-day inshore and offshore materials and more resemblances with dune and beach sediment, thus indicating these as the more likely source areas. In addition, preliminary results of SEM analysis of microtextural features imprinted in the surface of heavy minerals indicate an increase in the number of mechanical marks in the surface of palaeotsunami grains when compared with potential source materials (beach, dune, inshore and offshore samples). This work further reveals the potential to use heavy minerals as a complementary sedimentological tool in the study of palaeotsunami deposits.

  2. Metal, mineral waste processing and secondary recovery

    SciTech Connect

    Reddy, R.G.

    1987-04-01

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

  3. Weathering and Secondary Minerals in the Martian Meteorite Shergotty

    NASA Technical Reports Server (NTRS)

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

    2000-01-01

    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.

  4. Mars weathering analogs - Secondary mineralization in Antarctic basalts

    NASA Technical Reports Server (NTRS)

    Berkley, J. L.

    1982-01-01

    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.

  5. Ion beam microtexturing and enhanced surface diffusion

    NASA Technical Reports Server (NTRS)

    Robinson, R. S.

    1982-01-01

    Ion beam interactions with solid surfaces are discussed with particular emphasis on microtexturing induced by the deliberate deposition of controllable amounts of an impurity material onto a solid surface while simultaneously sputtering the surface with an ion beam. Experimental study of the optical properties of microtextured surfaces is described. Measurements of both absorptance as a function of wavelength and emissivity are presented. A computer code is described that models the sputtering and ion reflection processes involved in microtexture formation.

  6. Microtextural and mineral chemical analyses of andesite-dacite from Barren and Narcondam islands: Evidences for magma mixing and petrological implications

    NASA Astrophysics Data System (ADS)

    Ray, Dwijesh; Rajan, S.; Ravindra, Rasik; Jana, Ashim

    2011-02-01

    Andesite and dacite from Barren and Narcondam volcanic islands of Andaman subduction zone are composed of plagioclase, orthopyroxene, clinopyroxene, olivine, titanomagnetite, magnesio-hornblende and rare quartz grains. In this study, we use the results of mineral chemical analyses of the calc-alkaline rock suite of rocks as proxies for magma mixing and mingling processes. Plagioclase, the most dominant mineral, shows zoning which includes oscillatory, patchy, multiple and repetitive zonation and `fritted' or `sieve' textures. Zoning patterns in plagioclase phenocrysts and abrupt fluctuations in An content record different melt conditions in a dynamic magma chamber. `Fritted' zones (An55) are frequently overgrown by thin calcic (An72) plagioclase rims over well-developed dissolution surfaces. These features have probably resulted from mixing of a more silicic magma with the host andesite. Olivine and orthopyroxene with reaction and overgrowth rims (corona) suggest magma mixing processes. We conclude that hybrid magma formed from the mixing of mafic and felsic magma by two-stage processes - initial intrusion of hotter mafic melt (andesitic) followed by cooler acidic melt at later stage.

  7. Bisphosphonates do not Alter the Rate of Secondary Mineralization

    SciTech Connect

    R Fuchs; M Faillace; M Allen; R Phipps; L Miller; D Burr

    2011-12-31

    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 {mu}g/kg body weight), ALN (n=12; 2.4 {mu}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.

  8. Bisphosphonates do not alter the rate of secondary mineralization

    SciTech Connect

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

    2011-05-18

    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.

  9. Primary and Secondary Minerals in Meteorites Shed Light on the Habitability of Mars

    NASA Astrophysics Data System (ADS)

    Hausrath, E. M.; Gainey, S. R.; Bartlett, C. L.; Adcock, C. T.

    2015-07-01

    Primary and secondary minerals in meteorites record environmental conditions and potential nutrient availability. We present results interpreting these mineral assemblages with implications for the potential habitability of Mars.

  10. Secondary Iron Mineral Formation by Shewanellae Using Different Carbon Sources

    NASA Astrophysics Data System (ADS)

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

    2007-12-01

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

  11. Secondary sulfate minerals from Alum Cave Bluff: Microscopy and microanalysis

    SciTech Connect

    Lauf, R.J.

    1997-07-01

    Microcrystals of secondary sulfate minerals from Alum Cave Bluff, Great Smoky Mountains National Park, were examined by scanning electron microscopy and identified by X-ray fluorescence (XRF) in the SEM. Among the samples the author discovered three new rare-earth sulfates: coskrenite-(Ce), levinsonite-(Y), and zugshunstite-(Ce). Other minerals illustrated in this report include sulfur, tschermigite, gypsum, epsomite, melanterite, halotrichite, apjohnite, jarosite, slavikite, magnesiocopiapite, and diadochite. Additional specimens whose identification is more tentative include pickeringite, aluminite, basaluminite, and botryogen. Alum Cave is a ``Dana locality`` for apjohnite and potash alum, and is the first documented North American occurrence of slavikite.

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

    NASA Astrophysics Data System (ADS)

    Gysi, A.; Stefnsson, A.

    2009-12-01

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

  13. Secondary hydrothermal mineral system in the Campi Flegrei caldera, Italy

    NASA Astrophysics Data System (ADS)

    Mormone, A.; Piochi, M.; Di Vito, M. A.; Troise, C.; De Natale, G.

    2012-04-01

    Mineral systems generally develop around the deep root of the volcanoes down to the degassing magma chamber due the selective enrichment process of elements within the host-rock. The mineralization process depends on i) volcanic structure, ii) magma and fluid chemistry, iii) host-rock type and texture, iv) temperature and pressure conditions, and v) action timing that affect the transport and precipitation conditions of elements in the solution. Firstly, it generates a hydrothermal system that in a later phase may generate considerable metallogenic mineralization, in terms of both spatial extension and specie abundance. The study of secondary assemblages through depth and, possibly, through time, together with the definition of the general geological, structural, mineralogical and petrological context is the background to understand the genesis of mineral-to-metallogenic systems. We report our study on the Campi Flegrei volcano of potassic Southern Italy belt. It is a sub-circular caldera characterized by an active high-temperature and fluid-rich geothermal system affected by seismicity and ground deformation in the recent decades. The circulating fluids originate at deeper level within a degassing magma body and give rise at the surface up to 1500 tonnes/day of CO2 emissions. Their composition is intermediate between meteoric water and brines. Saline-rich fluids have been detected at ~3000 in downhole. The hydrothermal alteration varies from argillitic to phillitic, nearby the caldera boundary, to propilitic to thermo-metamorphic facies towards its centre. The Campi Flegrei caldera was defined as analogue of mineralized system such as White Island (New Zealand) that is an example of an active magmatic and embryonic copper porphyry system. In order to enhance the knowledge of such a type of embryonic-like metallogenic system, we have carried out macroscopic and microscopic investigations, SEM-EDS and electron microprobe analyses on selected samples from deep wells drilled in the '80s by the Agip Oil Company at the Campi Flegrei caldera. The new data have been merged with those available in the current volcanological, mineralogical and petrological literature in order to generate an innovative model and define the relationship between the caldera structure and the secondary mineralogy.

  14. Origin of secondary sulfate minerals on active andesitic stratovolcanoes

    USGS Publications Warehouse

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

    2005-01-01

    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.

  15. Microtextured Silicon Surfaces for Detectors, Sensors & Photovoltaics

    SciTech Connect

    Carey, JE; Mazur, E

    2005-05-19

    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.

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

    NASA Astrophysics Data System (ADS)

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

    2012-04-01

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

  17. Mandrels For Microtextured Small-Vessel Implants

    NASA Technical Reports Server (NTRS)

    Deininger, William D.; Gabriel, Stephen B.

    1989-01-01

    Research shows artificial blood-vessel and heart-valve implants made more compatible with their biological environments by use of regularly microtextured surfaces. In new manufacturing process, ion beam etches patterned array of small pillars on mandrel used to mold tubular plastic implant. Pillars create tiny regularly spaced holes in inner surface of tube. Holes expected to provide sites for attachment of healthy lining. Polytetrafluoroethylene (PTFE) used as mandrel material because it can be etched by ion beam.

  18. The role of secondary mineral precipitates on radionuclide sequestration at the Hanford Site

    SciTech Connect

    Um, Wooyong; Serne, R. Jeffrey; Yabusaki, Steven B.; Freedman, Vicky L.; Samson, Sherry D.; Nagy, Kathryn L.

    2004-06-27

    The effects of secondary mineral precipitates on radionuclide sequestration at the Hanford Site were investigated by reacting quartz and Hanford sediment (Warden Soil) with caustic solution of high ionic strength (2 M NaNO3), high pH (~13), high temperature (~90oC), and dissolved Al(0.01 M Al(NO3)3). Continuous Si dissolution and concomitant secondary mineral precipitation were the principal reactions observed. Nitrate-cancrinite was the dominant secondary precipitate on mineral surfaces after 3-10 days reaction time. The presence of dissolved Al in the simulated tank fluid was found to depress the net Si dissolved concentration. Based on batch equilibrium sorption results, secondary precipitates (cancrinite) at the primary mineral surfaces enhanced the sorption capacity of typical Hanford sediment for radionuclides of major concern at the Hanford Site such as 129I, 79Se, 99Tc, and 90Sr.

  19. The Chronology of Asteroid Accretion, Differentiation, and Secondary Mineralization

    NASA Technical Reports Server (NTRS)

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

    2008-01-01

    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.

  20. Method of making a coating of a microtextured surface

    DOEpatents

    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

    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.

  1. Aortoiliac thrombus secondary to a mineralized arteriosclerotic lesion.

    PubMed

    Drost, W T; Bahr, R J; Henry, G A; Campbell, G A

    1999-01-01

    A 12-year-old, neutered female, Siberian Husky dog presented with a hind limb weakness of one month duration. To facilitate making a diagnosis multiple imaging modalities were performed. These modalities included radiography, ultrasonography, magnetic resonance imaging (MRI), magnetic resonance angiography (MRA) and selective angiography of the abdominal aorta. In this dog, the MRI/MRA studies provided the first documentation of the external iliac thrombi and the collateral circulation via the lumbar arteries. At necropsy, an aortoiliac thrombus caused by a mineralized arteriosclerotic plaque was noted. PMID:10519305

  2. Sorption of trace constituents from aqueous solutions onto secondary minerals. II. Radium

    SciTech Connect

    Ames, L.L.; McGarrah, J.E.; Walker, B.A.

    1983-01-01

    Radium sorption efficiencies as a function of temperature, Ra concentration, and secondary mineral sorbate were determined in a 0.01 M NaCl solution. Radium sorption on a characterized clinoptilolite, montmorillonite, nontronite, opal, silica gel, illite, kaolinite, and glauconite under comparable experimental conditions allowed determination of Ra sorption efficiency curves for each, through use of Freundlich constants, over the same temperature and initial Ra solution concentration range Similar sorption data for U on the same secondary minerals over the same temperatures allowed comparison of sorption efficiencies for Ra and U. Clinoptilolite, illite, and nontronite were the most efficient Ra sorbents, while opal and silica gel were the poorest Ra sorbents. Generally, Ra sorption on secondary minerals was much greater than U sorption under the same experimental conditions. 13 references, 9 figures, 5 tables.

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

    NASA Astrophysics Data System (ADS)

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

    2011-12-01

    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.

  4. The Paris CM chondrite: Secondary minerals and asteroidal processing

    NASA Astrophysics Data System (ADS)

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

    2014-07-01

    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.

  5. Mineral phases and metals in baghouse dust from secondary aluminum production

    EPA Science Inventory

    Baghouse dust (BHD) is a solid waste generated by air pollution control systems during secondary aluminum processing (SAP). Management and disposal of BHD can be challenging in the U.S. and elsewhere. In this study, the mineral phases, metal content and metal leachability of 78...

  6. Weathering features and secondary minerals in Antarctic Shergottites ALHA77005 and LEW88516

    NASA Technical Reports Server (NTRS)

    Wentworth, Susan J.; Gooding, James L.

    1993-01-01

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

  7. Alteration Products and Secondary Minerals in Martian Meteorite Allan Hills 84001

    NASA Technical Reports Server (NTRS)

    Wentworth, S. J.; Thomas-Keprta, K. L.; McKay, D. S.

    1998-01-01

    The martian meteorites contain alteration products and secondary minerals that are a critical part of understanding their near-surface histories on both Mars and Earth. In some martian meteorites, suspected martian preterrestrial alteration products can be distinguished from terrestrial weathering effects Using scanning electron microscopy (SEM), field emission SEM (FE-SEM), transmission electron microscopy (TEM), and energy-dispersive X-ray analysis (EDS), we are studying natural fracture surfaces of ALH 84001 chips, including samples from both the interior and the exterior of the meteorite. Exterior samples include fusion crust surfaces, which are important in determining the extent of terrestrial weathering of meteorites. The focus of this study is weathering features and secondary minerals other than the distinctive carbonate globules that continue to be studied by many researchers.

  8. 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 ...

  9. Reduction of jarosite by Shewanella oneidensis MR-1 and secondary mineralization

    NASA Astrophysics Data System (ADS)

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

    2014-01-01

    Jarosite is a common mineral in a variety of environments formed by the oxidation of iron sulfide normally accompanying with the generation of acid mine drainage (AMD) in mining areas or acid rock drainages (ARD) in many localities. Decomposition of jarosite by dissimilatory iron reducing bacteria (DIRB) influences the mobility of many heavy metals generally accommodated in natural jarosite. This study examined the anaerobic reduction of synthesized jarosite by Shewanella oneidensis strain MR-1, a typical facultative bacteria. The release of ferrous and ferric ion, as well as sulfate and potassium, in the inoculated experimental group lasting 80 days is much higher than that in abiotic control groups. The detection of bicarbonate and acetate in experimental solution further confirms the mechanism of microbial reduction of jarosite, in which lactate acts as the electron donor. The produced ferrous iron stimulates the subsequent secondary mineralization, leading to precipitation and transformation of various iron-containing minerals. Green rust and goethite are the intermediate minerals of the microbial reduction process under anoxic conditions, and the end products include magnetite and siderite. In aerobic environments, goethite, magnetite and siderite were also detected, but the contents were relatively lower. While in abiotic experiments, only goethite has been detected as a product. Thus, the microbial reduction and subsequent mineral transformation can remarkably influence the geochemical cycling of iron and sulfur in supergene environments, as well as the mobility of heavy metals commonly accommodated in jarosite.

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

    SciTech Connect

    Wang, Guohui; Um, Wooyong

    2012-11-23

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

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

    NASA Astrophysics Data System (ADS)

    Wang, Guohui; Um, Wooyong

    2012-11-01

    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.

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

    NASA Astrophysics Data System (ADS)

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

    2006-12-01

    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) , c=19.55(1) , 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) , c=50.49(1) , 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 , whereas pittongite contains pyrochlore blocks of two different thicknesses, 6 and 12 . 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.

  13. Minerals

    MedlinePLUS

    ... Sledding, Skiing, Snowboarding, Skating Crushes What's a Booger? Minerals KidsHealth > For Kids > Minerals Print A A A Text Size What's in ... commercials for breakfast cereal always mention vitamins and minerals ? But when you think of minerals, food isn' ...

  14. Inhibition Effect of Secondary Phosphate Mineral Precipitation on Uranium Release from Contaminated Sediments

    SciTech Connect

    Shi, Zhenqing; Liu, Chongxuan; Zachara, John M.; Wang, Zheming; Deng, Baolin

    2009-11-01

    The inhibitory effect of phosphate mineral precipitation on uranium release was evaluated using a U(VI)-contaminated sediment collected from the US Department of Energy (DOE) Hanford site. The sediment contained U(VI) that was associated with diffusion-limited intragrain regions within its mm-size granitic lithic fragments. The sediment was first treated to promote phosphate mineral precipitation in batch suspensions spiked with 1 and 50 mM aqueous phosphate, and calcium in a stoichiometric ratio of mineral hydroxyapatite. The phosphate-treated sediment was then leached to solubilize contaminant U(VI) in a column system using a synthetic groundwater that contained chemical components representative of Hanford groundwater. Phosphate treatment significantly decreased the extent of U(VI) release from the sediment. Within the experimental duration of about 200 pore volumes, the effluent U(VI) concentrations were consistently lower by over one and two orders of magnitude after the sediment was treated with 1 and 50 mM of phosphate, respectively. Measurements of solid phase U(VI) using various spectroscopes and chemical extraction of the sediment collectively indicated that the inhibition of U(VI) release from the sediment was caused by: 1) U(VI) adsorption to the secondary phosphate precipitates and 2) the transformation of initially present U(VI) mineral phases to less soluble forms.

  15. Bone mineral density evaluation among patients with neuromuscular scoliosis secondary to cerebral palsy☆

    PubMed Central

    Rezende, Rodrigo; Cardoso, Igor Machado; Leonel, Rayana Bomfim; Perim, Larissa Grobério Lopes; Oliveira, Tarcísio Guimarães Silva; Jacob Júnior, Charbel; Júnior, José Lucas Batista; Lourenço, Rafael Burgomeister

    2014-01-01

    Objective To evaluate bone mineral density among patients with neuromuscular scoliosis secondary to quadriplegic cerebral palsy. Methods This was a descriptive prospective study in which both bone densitometric and anthropometric data were evaluated. The inclusion criteria used were that the patients should present quadriplegic cerebral palsy, be confined to a wheelchair, be between 10 and 20 years of age and present neuromuscular scoliosis. Results We evaluated 31 patients (20 females) with a mean age of 14.2 years. Their mean biceps circumference, calf circumference and body mass index were 19.4 cm, 18.6 cm and 16.9 kg/m2, respectively. The mean standard deviation from bone densitometry was −3.2 (z-score), which characterizes osteoporosis. Conclusion There is high incidence of osteoporosis in patients with neuromuscular scoliosis secondary to quadriplegic cerebral palsy. PMID:26229882

  16. Optimal design of superhydrophobic surfaces using a paraboloid microtexture.

    PubMed

    Tie, Lu; Guo, Zhiguang; Li, Wen

    2014-12-15

    Due to the crucial role of surface roughness, it has been recently proposed to design optimal and extract geometrical microstructures for practical fabrications of superhydrophobic surfaces. In this work, a paraboloid microtexture is employed as a typical example to theoretically establish a relationship between surface geometry and superhydrophobic behavior for a final optimal design. In particular, based on a thermodynamic approach, the effects of all the geometrical parameters for such a paraboloid microtexture on free energy (FE) and free energy barrier (FEB) as well as equilibrium contact angle (ECA) and contact angle hysteresis (CAH) of a superhydrophobic surface have been systematically investigated in detail. It is interestingly noted that the droplet position for metastable state is closely related to the intrinsic CA of the surface. Furthermore, the paraboloid base steepness plays a significant important role in ECA and CAH, and a critical steepness is necessary for the transition from noncomposite to composite states, which can be judged using a proposed criterion. Moreover, the superhydrophobicity depends strongly the surface geometrical dimension for noncomposite state, while it is not sensitive for composite state. Additionally, both vibrational energy and geometrical dimension affect the transition from noncomposite to composite wetting states, and a comprehensive criterion for such transition can be obtained. Finally, using such criterion, it is revealed that the paraboloidal protrusion is the most optimal geometry among the three typical microtextures for ideal superhydrophobicity. PMID:25265581

  17. Reactivity of Primary Soil Minerals and Secondary Precipitates beneath Leaking Hanford Waste Tanks

    SciTech Connect

    Nagy, Kathryn L.; Serne, R. Jeff; Yabusaki

    2001-06-01

    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 their future mobility. The high ionic strength, high pH, and high aluminum concentrations in the tank liquids can significantly alter the vadose zone sediments through dissolution of primary minerals and precipitation of secondary minerals. Dissolution and precipitation directly influence (1) the flow paths that control contaminant transport and (2) the reactivity of the solid matrix that controls contaminant mobility. The impact of these processes, however, depends on mineral reaction kinetics and the dynamic interaction of the reactions with the flow field and contaminant sorption, neither of which are well-known for this extreme chemical system. Data obtained will be directly useful to other EMSP projects addressing contaminant mobility in the vadose zone. We are addressing three specific issues: (1) Recognized factors that control the kinetics of dissolution and precipitation must be quantified for the unnatural system of tank solutions mixing with soils, including effects of high pH, high ionic strength (especially NaNO3 solutions), temperature, and saturation state. (2) A clear understanding of the roles of nucleation mechanism, nucleation sites on soils minerals, and the role of reactive surface area in simultaneous dissolution and precipitation reactions are the key unknown components in comprehending this contaminated soil system. (3) Results obtained will help build a mechanistic understanding of how tank fluids migrate through the vadose zone. Local changes in porosity and permeability will dictate preferential flow paths which directly regulate the transport of later arriving chemical species. Changes in mineral surface area affect sorption site distribution. A comprehensive model is needed that integrates these feedback mechanisms with all the critically available data.

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

    PubMed

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

    2011-01-01

    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

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

    NASA Astrophysics Data System (ADS)

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

    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.

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

    PubMed Central

    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

    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

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

    PubMed

    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

    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

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

    SciTech Connect

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

    2012-05-01

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

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

    NASA Astrophysics Data System (ADS)

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

    1995-09-01

    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]

  4. Quasi-liquid states observed on ion beam microtextured surfaces

    NASA Technical Reports Server (NTRS)

    Rossnagel, S. M.; Robinson, R. S.

    1982-01-01

    Liquid-like properties have been observed on surface structures developed by means of ion beam microtexturing. The structures include cones, pyramids, or wavelike formations. The observed liquid-like effects are drips and ripples on the sides of cones, droplet formation, the apparent flow and coalescence of closely packed structures, wetting angle and other surface tension effects, and the bending of cones by additional heating. The bulk temperatures are in the range of 50-600 C. These effects are seen to some extent on Cu, Al, Au, Pb, and Ni substrates.

  5. Reactivity of Primary Soil Minerals and Secondary Precipitates Beneath Leaking Hanford Waste Tanks

    SciTech Connect

    Nagy, Kathryn L.; Sturchio, Neil C.

    2003-06-01

    This project, renewal of a previous EMSP project of the same title, is in its first year of funding at the University of Illinois at Chicago. The purpose is to continue investigating rates and mechanisms of reactions between primary sediment minerals found in the Hanford subsurface and leaked waste tank solutions. The goals are to understand processes that result in (1) changes in porosity and permeability of the sediment and resultant changes in flow paths of the contaminant plumes, (2) formation of secondary precipitates that can take up contaminants in their structures, and (3) release of mineral components that can drive redox reactions affecting dissolved contaminant mobility. A post-doctoral scientist, Dr. Sherry Samson, has been hired and two masters of science students are beginning to conduct experimental research. One research project that is underway is focused on measurement of the dissolution rates of plagioclase feldspar in high pH, high nitrate, high Al-bearing solutions characteristic of the BX tank farms. The first set of experiments is being conduced at room temperature. Subsequent experiments will examine the role of temperature because tank solutions in many cases were near boiling when leakage is thought to have occurred and temperature gradients have been observed beneath the SX and BX tank farms. The dissolution experiments are being conducted in stirred-flow kinetic reactors using powdered labradorite feldspar from Pueblo Park, New Mexico.

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

    PubMed Central

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

    2015-01-01

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

  7. Origin, timing, and temperature of secondary calcite-silica mineral formation at Yucca Mountain, Nevada

    NASA Astrophysics Data System (ADS)

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

    2003-03-01

    The origin of secondary calcite-silica minerals in primary and secondary porosity of the host Miocene tuffs at Yucca Mountain has been hotly debated during the last decade. Proponents of a high-level nuclear waste repository beneath Yucca Mountain have interpreted the secondary minerals to have formed from cool, descending meteoric fluids in the vadose zone; critics, citing the presence of two-phase fluid inclusions, argued that the minerals could only have formed in the phreatic zone from ascending hydrothermal fluids. Understanding the origin, temperature, and timing of these minerals is critical in characterizing geologically recent fluid flux at the site, and has significant implications to whether waste should be stored at Yucca Mountain. Petrographic and paragenetic studies of 155 samples collected from the Exploratory Studies Facility (ESF) and repository block cross drift (ECRB) tunnels indicate that heterogeneously distributed calcite with lesser chalcedony, quartz, opal, and fluorite comprise the oldest secondary minerals. These are typically overgrown by intermediate-aged calcite, often exhibiting distinctive bladed habits. The youngest event recorded across the site is the deposition of Mg-enriched (up to ˜1 wt%) and depleted, growth-zoned calcite intergrown with U-enriched opal. The cyclical variation in Mg enrichment and depletion is probably related to climate changes that have occurred during the last few million years. The distribution of secondary minerals is consistent with precipitation in the vadose zone. Fluid inclusion petrography of sections from the 155 samples determined that 96% of the fluid inclusion assemblages (FIAs) contained liquid-only inclusions that formed at ambient temperatures (<35°C). However, 50% of the samples (n = 78) contained relatively rare FIA that contain both liquid-only and liquid plus vapor inclusions (herein termed two-phase FIAs) that formed at temperatures above 35°C. Virtually all of these two-phase FIAs occur in paragenetically old calcite; rare two-phase inclusion assemblages were also observed in early fluorite and quartz, and early-intermediate calcite. Homogenization temperatures (≡ trapping temperatures) across Yucca Mountain are generally 45 to 60°C, but higher temperatures reaching 83°C were recorded in calcite from the north portal and ramp of the ESF. Cooler temperatures of ˜35 to 45°C were recorded in the intensely fractured zone. Multiple populations of two-phase FIAs from lithophysal cavities in the ESF and ECRB cross drift indicate early fluid cooling with time from temperatures >45°C in early calcite, to <35 to 45°C in paragenetically younger calcite. Freezing point depressions range from -0.2 to -1.6°C, indicating trapping of a low salinity fluid. The majority of intermediate calcite and all outermost Mg-enriched calcite contains rare all-liquid inclusions and formed from ambient temperature (<35°C) fluids. Carbon and oxygen isotope data reveal a consistent trend of decreasing δ 13C (from 9.5 to -8.5‰) and increasing δ 18O (from 5.2 to 22.1‰) values from paragenetically early calcite to Mg-enriched growth-zoned calcite. Depleted δD values (-131 to -90‰) of inclusion fluids from intermediate and the youngest Mg-enriched calcite indicate derivation from surface meteoric fluids. Recalculation of δ 18O H 2O values of -12 to -10‰ is consistent with derivation from paleometeoric fluids. Results of integrated U-Pb dating (opal and chalcedony) and fluid inclusion microthermometry indicate that two-phase FIAs that trapped fluids of >50°C are older than 6.29 ± 0.30 Ma. Two-phase FIAs in paragenetically later calcite, which formed from fluids of 35 to 45°C, are older than 5.32 ± 0.02 Ma. There is no evidence for trapping of fluids with elevated temperatures during the past 5.32 my. The youngest Mg-enriched calcite intergrown with opal began to precipitate between about 1.9 to 2.9 Ma and has continued to precipitate within the past half million years. The presence of liquid-only inclusions and the consistent occurrence of Mg-enriched calcite and opal as the youngest event indicate a minor, but chemically distinct, ambient temperature (<35°C) fluid flux during the past 2 to 3 my.

  8. Minerals

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fish require the same minerals or inorganic elements as terrestrial animals for tissue formation, osmoregulation and various metabolic functions. Those required in large quantities are termed macro- or major minerals and those required in small quantities are called micro- or trace minerals. Fish ca...

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

    SciTech Connect

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

    2009-02-25

    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 et al., 2008, GCA) 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 Tisser and [2006] or the aluminum inhibition model proposed by Oelkers et al. [1994], 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. 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, SiO{sub 2}(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.

  10. 9 M.y. record of southern Nevada climate from Yucca Mountain secondary minerals

    SciTech Connect

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

    1998-12-01

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

  11. Mineral phases and metals in baghouse dust from secondary aluminum production.

    PubMed

    Huang, Xiao-Lan; El Badawy, Amro M; Arambewela, Mahendranath; Adkins, Renata; Tolaymat, Thabet

    2015-09-01

    Baghouse dust (BHD) is a solid waste generated by air pollution control systems during secondary aluminum processing (SAP). Management and disposal of BHD can be challenging in the U.S. and elsewhere. In this study, the mineral phases, metal content and metal leachability of 78 BHD samples collected from 13 different SAP facilities across the U.S. were investigated. The XRD semi-quantitative analysis of BHD samples suggests the presence of metallic aluminum, aluminum oxide, aluminum nitride and its oxides, spinel, elpasolite as well as diaspora. BHD also contains halite, sylvite and fluorite, which are used as fluxes in SAP activities. Total aluminum (Al) in the BHD samples averaged 18% by weight. Elevated concentrations of trace metals (>100 μg L(-1) As; >1000 μg L(-1) Cu, Mn, Se, Pb, Mn and Zn) were also detected in the leachate. The U.S. toxicity characteristic leaching procedure (TCLP) results showed that some samples leached above the toxicity limit for Cd, Pb and Se. Exceeding the TCLP limits in all sample is independent of facilities generating the BHD. From the metal content perspective only, it appears that BHD has a higher potential to exhibit toxicity characteristics than salt cake (the largest waste stream generated by SAP facilities). PMID:25898346

  12. Effects of salinity and the extent of water on supercritical CO2-induced phlogopite dissolution and secondary mineral formation.

    PubMed

    Shao, Hongbo; Ray, Jessica R; Jun, Young-Shin

    2011-02-15

    To ensure the viability of geologic CO2 sequestration (GCS), we need a holistic understanding of reactions at supercritical CO2 (scCO2)-saline water-rock interfaces and the environmental factors affecting these interactions. This research investigated the effects of salinity and the extent of water on the dissolution and surface morphological changes of phlogopite [KMg2.87Si3.07Al1.23O10(F,OH)2], a model clay mineral in potential GCS sites. Salinity enhanced the dissolution of phlogopite and affected the location, shape, size, and phase of secondary minerals. In low salinity solutions, nanoscale particles of secondary minerals formed much faster, and there were more nanoparticles than in high salinity solutions. The effect of water extent was investigated by comparing scCO2-H2O(g)-phlogopite and scCO2-H2O(l)-phlogopite interactions. Experimental results suggested that the presence of a thin water film adsorbed on the phlogopite surface caused the formation of dissolution pits and a surface coating of secondary mineral phases that could change the physical properties of rocks. These results provide new information for understanding reactions at scCO2-saline water-rock interfaces in deep saline aquifers and will help design secure and environmentally sustainable CO2 sequestration projects. PMID:21222477

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

    SciTech Connect

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

    1981-01-01

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

  14. Minerals

    MedlinePLUS

    ... some of the minerals you get from food. Calcium Calcium is the top macromineral when it comes to ... on tasty food. Which foods are rich in calcium? dairy products, such as milk, cheese, and yogurt ...

  15. Radionuclide Incorporation in Secondary Crystalline Minerals Resulting from Chemical Weathering of Selected Waste Glasses: Progress Report for Subtask 3d

    SciTech Connect

    SV Mattigod; DI Kaplan; VL LeGore; RD Orr; HT Schaef; JS Young

    1998-10-23

    Experiments were conducted in fiscal year 1998 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-Petiormance Assessment (ILAW-PA) to generate data on radionuclide mobilization and transport in a near-field enviromnent of disposed vitrified wastes. An initial experiment was conducted to identify the types of secondary minerals that form from two glass samples of differing compositions, LD6 and SRL202. Chemical weathering of LD6 glass at 90oC in contact with an aliquot of uncontaminated Hanford Site groundwater resulted in the formation of a Crystalline zeolitic mineral, phillipsite. In contrast similar chemical weathering of SRL202 glass at 90"C resulted in the formation of a microcrystalline smectitic mineral, nontronite. A second experiment was conducted at 90"C to assess the degree to which key radionuclides would be sequestered in the structure of secondary crystalline minerals; namely, phillipsite and nontronite. Chemical weathering of LD6 in contact with radionuclide-spiked Hanford Site groundwater indicated that substantial ilactions of the total activities were retained in the phillipsite structure. Similar chemical weathering of SRL202 at 90"C, also in contact with radionuclide-spiked Hanford Site groundwater, showed that significant fractions of the total activities were retained in the nontronite structure. These results have important implications regarding the radionuclide mobilization aspects of the ILAW-PA. Additional studies are required to confkm the results and to develop an improved under- standing of mechanisms of sequestration and attenuated release of radionuclides to help refine certain aspects of their mobilization.

  16. Preliminary bounds on the water composition and secondary mineral development that may influence the near-field environment

    SciTech Connect

    Whitbeck, M.; Glassley, W.

    1998-02-01

    The evolution of the water chemistry and secondary mineral development in the vicinity of the near-field of a potential Yucca Mountain high level nuclear waste repository will be controlled by temperature, and interaction of water with rock over time. This report describes initial bounds on water composition and secondary mineral development, as a function of time, temperature, and rock type (devitrified, welded tuff and vitrophyre). The code EQ3/6 was used in the calculations, with explicit use of transition state theory models for mineral dissolution rates for the framework minerals of the tuff. Simulations were run for time durations sufficient to achieve steady state conditions. Uncertainty in the calculations, due to uncertainty in the measured dissolution rates, was considered by comparing results in simulations in which rates were varied within the range of known uncertainties for dissolution rate constants. The results demonstrate that the steady state mineralogy and water compositions are relatively insensitive to the rock unit modeled, which is consistent with the fact that the compositions of the rock units in the vicinity if the potential repository are similar, and will tend toward similar thermodynamic free energy minima, for similar rock:water ratios. Significant differences are observed, however, for large differences in rock: water ratios. The rates at which this end point condition are approached are a function of the rate parameters used, and can vary by orders of magnitude.

  17. Comparison of microstructure of superplastically deformed synthetic materials and ultramylonite: Coalescence of secondary mineral grains via grain boundary sliding

    NASA Astrophysics Data System (ADS)

    Hiraga, T.; Miyazaki, T.; Tasaka, M.; Yoshida, H.

    2011-12-01

    Using very fine-grained aggregates of forsterite containing ~10vol% secondary mineral phase such as periclase and enstatite, we have been able to demonstrate their superplascity, that is, achievement of more than a few 100 % tensile strain (Hiraga et al. 2010). Superplastic deformation is commonly considered to proceed via grain boundary sliding (GBS) which results in grain switching in the samples. Hiraga et al. (2010) succeeded in detecting the operation of GBS from observing the coalescence of grains of secondary phase in superplastically deformed samples. The secondary phase pins the motion of grain boundaries of the primary phase; however, the reduction of the number of the grains of secondary phase due to their coalescence allows grain growth of the primary phase. We analyzed the relationships between grain size of the primary and secondary phases, between strain and grain size, and between strain and the number of coalesced grains in the superplastically deformed samples. The results supports participation of all the grains of the primary phase in grain switching process indicating that the grain boundary sliding accommodates almost entire strain during the deformation. Mechanical properties of these materials such as their stress and grain size exponents of 1-2 do not conflict this conclusion. We applied the relationships obtained from analyzing superplastic materials to the microstructure of the natural samples, which has been considered to have deformed via grain boundary sliding, that is, ultramylonite. The microstructure of greenschist-grade ultramylonite reported by Fliervoet et al. (1997) was analyzed. Distributions of the mineral phases (i.e., quartz, plagioclase, K-feldspar and biotite) show distinct coalescence of the same mineral phases in the direction almost perpendicular to the foliation of the rock. The number of coalesced grains indicates that the strain that rock experienced is > 2. [reference] Hiraga et al. (2010) Nature 468, 1091-1094; Fliervoet et al. (1997) Journal of Structural Geology 19, 1495-1520

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

    USGS Publications Warehouse

    Maher, K.; Steefel, Carl; White, A.F.; Stonestrom, D.A.

    2009-01-01

    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.

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

    NASA Astrophysics Data System (ADS)

    Maher, Kate; Steefel, Carl I.; White, Art F.; Stonestrom, Dave A.

    2009-05-01

    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. Acta72 (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. Acta70 (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. Acta58 (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, SiO 2(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.

  20. Minerals and rocks, what a passion! A CLIL unit in an Italian lower secondary class

    NASA Astrophysics Data System (ADS)

    Papini, Piera; Fiorineschi, Beatrice

    2015-04-01

    CLIL means Content and Language Integrated Learning. Since September 2014 the teaching of a discipline in a foreign language has been compulsory in the final year of all high schools of Italy and recommended in lower secondary schools. So I decided to take part in a training course about "CLIL in Sciences teaching " that ANISN (Associazione Nazionale Insegnanti di Scienze Naturali ) was being held in Bologna from October to December 2014. There I learned that CLIL is much more than the translation of a traditional lecture to a foreign language. It is actually a set of new methodologies, largely based on Bloom's taxonomy, and making use of many kinds of technical support often referred to as "scaffolding" . It provides a context to improve communication because "natural language is never learned divorced from meaning". But CLIL is even more effective in order to learn the content, which is more important here than in immersion methodology. In the course we had to chose a subject , develop it in a structured unit, experiment the unit in a class of ours, using just English, and finally present it to the colleagues in Bologna. I decided to do the activity with 13 year old students. We had started the science lessons with chemistry, this year and I needed a subject consistent with that. So the choice was: Minerals! Because they belong to chemistry, being chemical compounds. Subsequently, even when the course in Bologna had come to an end, we continued with: Rocks! Since the pupils were pleased to do it and I was satisfied with their results. I worked together with my colleague who teaches English in the same class. We developed the subject following the instructions I had been given at the course: we showed the students videos found on line, providing them with the script; we made the text easier for them; we made them work in couples; I organized lab activities to improve learning skills to which they could apply their knowledge . Cross - curricolar links are an important advantage of such a unit; minerals and rocks are linked to physics, chemistry, geomorphology, and also to geography , history, econonomics, and maths. The follow up activities were even more interesting. When we found that the weathering of feldspars to clay can increase the probability of a landslide, I gave the students an example of one of the most famous landslides in the world, Vajont. The students were so interested that they looked by themselves for further information about that tragedy, and the context in which it was possible to happen. Another concept which turned out to be fascinating to the students was how rocks can tell us the geological history of a region . The results of the activities were quite good in Sciences and good in English; the students accepted the challenge, they played along with us and had fun explaining their activities during the open labs devoted to the families of younger students.

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

    NASA Astrophysics Data System (ADS)

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

    2011-12-01

    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.

  2. Preservation of primary mineral inclusions and secondary mineralization in igneous zircon: a case study in orthogneiss from the Blue Ridge, Virginia

    NASA Astrophysics Data System (ADS)

    Bell, Elizabeth A.

    2016-03-01

    A wide variety of minerals occur as inclusions in igneous zircon and can provide valuable evidence of source magma composition from originally magmatic zircons in metamorphic and clastic sedimentary rocks. However, it is not clear the extent to which zircons preserve the primary composition of their inclusions through a variety of geologic processes. This paper documents a case study of inclusion-rich, originally igneous zircon from an orthogneiss in the Blue Ridge of southwest Virginia. Zircon inclusions isolated from cracks contain 4 % clearly metamorphic phases (mainly in hosts with disturbed U-Pb systems) and otherwise retain distinct plagioclase chemistry, K-feldspar/plagioclase pairs, and biotite with much wider-ranging Mg/(Mg + Fe) than biotite in the rock matrix. A clearly secondary mineralization suite filling cracks in the zircons consists of quartz, biotite, albite, and epidote. Overall, these zircons preserve mineral inclusions distinct from their current host rock (except when exposed to external environments via cracks), demonstrating that non-metamict zircons may preserve their primary inclusion assemblages through later amphibolite to lower granulite facies metamorphism.

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

    NASA Astrophysics Data System (ADS)

    Goodfellow, Bradley W.

    2012-12-01

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

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

    SciTech Connect

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

    2013-01-01

    In order to evaluate the extent of CO{sub 2}waterrock interactions in geological formations for C sequestration, three batch experiments were conducted on alkali feldsparsCO{sub 2}brine interactions at 150200 C and 300 bars. The elevated temperatures were necessary to accelerate the reactions to facilitate attainable laboratory measurements. Temporal evolution of fluid chemistry was monitored by major element analysis of in situ fluid samples. SEM, TEM and XRD analysis of reaction products showed extensive dissolution features (etch pits, channels, kinks and steps) on feldspars and precipitation of secondary minerals (boehmite, kaolinite, muscovite and paragonite) on feldspar surfaces. Therefore, these experiments have generated both solution chemistry and secondary mineral identity. The experimental results show that partial equilibrium was not attained between secondary minerals and aqueous solutions for the feldspar hydrolysis batch systems. Evidence came from both solution chemistry (supersaturation of the secondary minerals during the entire experimental duration) and metastable co-existence of secondary minerals. The slow precipitation of secondary minerals results in a negative feedback in the dissolutionprecipitation loop, reducing the overall feldspar dissolution rates by orders of magnitude. Furthermore, the experimental data indicate the form of rate laws greatly influence the steady state rates under which feldspar dissolution took place. Negligence of both the mitigating effects of secondary mineral precipitation and the sigmoidal shape of rate?G{sub r} relationship can overestimate the extent of feldspar dissolution during CO{sub 2} storage. Finally, the literature on feldspar dissolution in CO{sub 2}-charged systems has been reviewed. The data available are insufficient and new experiments are urgently needed to establish a database on feldspar dissolution mechanism, rates and rate laws, as well as secondary mineral information at CO{sub 2} storage conditions.

  5. 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)

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

    1998-08-01

    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.

  6. Detoxification and mineralization of Acid Blue 74: study of an alternative secondary treatment to improve the enzymatic decolourization.

    PubMed

    Mndez-Hernndez, J E; Ramrez-Vives, F; Sols-Oba, M; Sols-Oba, A; Sobrino-Figueroa, A S; Loera, O

    2013-05-01

    Many reports describe the decolourization of dyes by fungal enzymes. However, these enzymes do not contribute to dye mineralization but only to its biotransformation into less coloured or colourless molecules persisting in solution. Therefore, it is essential to analyse the identity of the metabolites produced during enzymatic treatments and its biodegradation into an appropriate system. The present work examines the decolourization/detoxification of a simulated effluent (containing Acid Blue 74) by fungal enzymes and proposes a secondary treatment using an anaerobic system to improve the enzymatic decolourization through the complete mineralization of the dye. Ligninolytic enzymes were produced by solid culture using the thermo-tolerant fungus Fomes sp. EUM1. The enzymes produced showed a high rate of decolourization (>95 % in 5 h) and were stable at elevated temperature (40 C) and ionic strength (NaCl, 50 mM). Isatin-5-sulphonic acid was identified via (1)H-NMR as oxidation product; tests using Daphnia magna revealed the non-toxic nature of this compound. To improve the enzymatic degradation and avoid coupling reactions between the oxidation products, the effluent was subjected to an anaerobic (methanogenic) treatment, which achieved high mineralization efficiencies (>85 %). To confirm the mineralization of isatin-5-sulphonic acid, a specific degradation study, which has not been reported before, with this single compound was conducted under the same conditions; the results showed high removal efficiencies (86 %) with methane production as evidence of mineralization. These results showed the applicability of an anaerobic methanogenic system to improve the enzymatic decolourization/detoxification of Acid Blue 74 and achieve its complete mineralization. PMID:23247918

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

    NASA Astrophysics Data System (ADS)

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

    2015-02-01

    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.

  8. Evaluation of microtexture using x-ray pole figures obtained from single grains

    NASA Astrophysics Data System (ADS)

    Ermakova, Natalia Y.; Zolotorevskii, Nikolai Y.; Mirsoev, V. R.; Titovets, Yuri F.

    1999-05-01

    The method is described which enables to determine microtexture, that is orientation distribution within individual grains of polycrystal. The microtexture is evaluated on the base of X-ray pole distributions measured for separate reflections, referred to as microscopic pole figures (MPF). The procedure for treatment of experimental MPF and the following computation of orientation distribution function is described in detail. The precision of the microtexture evaluation and possible ways of its improvement are discussed. As an example of the method application, orientation distribution within a single grain of aluminum polycrystal deformed by uniaxial compression up to 32% has been examined. Mean rotation of the grain lattice differs from that predicted theoretically. Furthermore, the orientation spread inside the grain develops with increasing plastic strain, that is of the same order of magnitude that the mean grain rotation.

  9. Spatial distributions of secondary minerals in the Martian meteorite MIL 03346,168 determined by Raman spectroscopic imaging

    NASA Astrophysics Data System (ADS)

    Ling, Zongcheng; Wang, Alian

    2015-06-01

    Miller Range (MIL) 03346 is a nakhlite meteorite that has been extensively studied due to its unique complex secondary mineral phases and their potential implications for the hydrologic history of Mars. We conducted a set of Raman spectroscopic and Raman imaging studies of MIL 03346,168, focusing on the secondary mineral phases and their spatial distributions, with a goal to better understand the possible processes by which they were generated on Mars. This study revealed three types of calcium sulfates, a solid solution of (K, Na)-jarosite and two groups of hydrated species with low crystallinity (HSLC) in the veins and/or mesostasis areas of the meteorite. The most abundant Ca-sulfate is bassanite that suggests two possible paths for its direct precipitation from a Ca-S-H2O brine, either having low water activity or with incomplete development (producing bassanite with gypsum microcrystals) on Mars. The second most abundant Ca-sulfate is soluble ?-CaSO4 which raises a new question on the origins of this phase in the Martian meteorite, since ?-CaSO4 readily hydrates in the laboratory but is apparently stable in Atacama Desert. The close spatial relationship of (K, Na)-jarosite solid solutions with rasvumite (KFe2S3), magnetite, HSLC, and fine-grained low-crystallinity alkali feldspar in mesostasis suggests a potential in situ formation of mesostasis jarosite from these Fe-K,Na-S-O-H2O species.

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

    SciTech Connect

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

    2003-09-29

    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.

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

    NASA Astrophysics Data System (ADS)

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

    2004-07-01

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

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

    SciTech Connect

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

    2013-06-03

    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.

  13. A patterned microtexture to reduce friction and increase longevity of prosthetic hip joints

    PubMed Central

    Chyr, Anthony; Qiu, Mingfeng; Speltz, Jared; Jacobsen, Ronald L.; Sanders, Anthony P.; Raeymaekers, Bart

    2014-01-01

    More than 285,000 total hip replacement surgeries are performed in the US each year. Most prosthetic hip joints consist of a cobalt-chromium (CoCr) femoral head that articulates with a polyethylene acetabular component, lubricated with synovial fluid. The statistical survivorship of these metal-on-polyethylene prosthetic hip joints declines significantly after 10 to 15 years of use, primarily as a result of polyethylene wear and wear debris incited disease. The current engineering paradigm to increase the longevity of prosthetic hip joints is to improve the mechanical properties of the polyethylene component, and to manufacture ultra-smooth articulating surfaces. In contrast, we show that adding a patterned microtexture to the ultra-smooth CoCr femoral head reduces friction when articulating with the polyethylene acetabular liner. The microtexture increases the load-carrying capacity and the thickness of the joint lubricant film, which reduces contact between the articulating surfaces. As a result, friction and wear is reduced. We have used a lubrication model to design the geometry of the patterned microtexture, and experimentally demonstrate reduced friction for the microtextured compared to conventional smooth surrogate prosthetic hip joints. PMID:25013240

  14. Mineral Association Changes the Secondary Structure and Dynamics of Murine Amelogenin

    SciTech Connect

    Lu, Junxia; Xu, Yimin; Buchko, Garry W.; Shaw, Wendy J.

    2013-12-18

    Biomineralization proteins, present during the formation of hard tissues including bones, teeth, egg shells and nacre, result in the exquisite structures and properties of the resulting materials.[1] The structure of these proteins is often implicated in the control of the mineral properties, however very little structural data is available for the bulk of these proteins due to the difficulty in determining structures of immobilized proteins. Solid-state NMR is uniquely suited to the study of the structure of proteins bound to surfaces, demonstrated with the structural and orientation insights provided for the hydroxyapatite mineralization proteins statherin and the amelogenin, LRAP.[2] While these data are some of the only structural data available for this important class of protein, the experiments are often expensive and time consuming, due to the need to prepare and measure samples with isolated spin pairs, and are limited to a size of ~60 residues. In this work, we utilized a combination of 1D and recent 2D[3] solid-state NMR techniques along with a sparsely labelled sample to characterize the structure and dynamics of potential HAP binding residues of the 180 residue enamel protein, amelogenin. Amelogenin nanospheres and mineral bound amelogenin were investigated and a shift from unstructured to -sheet structure was observed, along with a decrease in protein flexibility. This work provides the first molecular level structure and dynamic information of full-length amelogenin on the surface of hydroxyapatite (HAP) and within nanospheres, and demonstrates the ability to evaluate structural characteristics of large biomineralization proteins bound to their physiologically relevant surface. The research was performed at the Pacific Northwest National Laboratory (PNNL), a facility operated by Battelle for the U.S. Department of Energy, with a portion of it performed at the W.R. Wiley Environmental Molecular Sciences Laboratory (EMSL), a national scientific user facility sponsored by the U.S. DOE Biological and Environmental Research program.

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

    NASA Astrophysics Data System (ADS)

    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

    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.

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

    NASA Astrophysics Data System (ADS)

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

    2005-12-01

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

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

    SciTech Connect

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

    2013-12-02

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

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

    SciTech Connect

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

    2013-10-01

    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.

  19. Field Observation of Heterogeneous Formation of Secondary Organic Aerosols on Asian Mineral Dust Surfaces

    NASA Astrophysics Data System (ADS)

    Wang, G.

    2014-12-01

    This study investigated the heterogeneous formation mechanism of secondary organic aerosols (SOA) on dust surfaces by characterizing molecular compositions and size distributions of dicarboxylic acids, keto-carboxylic acids, a-dicarbonyls and inorganic ions in size-segregated aerosols (9-stages) in the urban atmosphere of Xi'an, China during dust storm periods and comparing with those in non-dust storm periods. In the presence of a dust storm, all the above mentioned SOA species in Xi'an are predominantly enriched on coarse particles (>2.1 m). Oxalic acid well correlated with NO3- (r2=0.72, p<0.01) rather than SO42-. This phenomenon differs greatly from the observed particles during a non-dust storm period, which is characterized by an enrichment of the SOA on fine particles (<2.1 m) with a strong correlation between C2 and SO42-. We propose a three-step formation pathway to explain these observations as follows. First, nitric acid and nitrogen oxides react with dust to form a liquid film on the surface via water vapor-absorption of calcium nitrate. Second, gaseous Gly and mGly partition into the aqueous-phase. Finally, the aqueous-phase Gly and mGly oxidize into glyoxylic acid (wC2), followed by a further oxidation into C2. To the best of our knowledge, we found for the first time the enrichments of glyoxal (Gly) and methylglyoxal (mGly) on dust surfaces. Our data indicate a more critical role of nitrate than sulfate in the heterogeneous formation process of SOA on dust surfaces. Mass ratio of C2 to wC2 was found to be higher in coarse particles than in fine particles during the dust storm events, which is due to low acidity condition of large particles that is favorable for conversion of wC2 to C2.

  20. Organic carbon and reducing conditions lead to cadmium immobilization by secondary Fe mineral formation in a pH-neutral soil.

    PubMed

    Muehe, E Marie; Adaktylou, Irini J; Obst, Martin; Zeitvogel, Fabian; Behrens, Sebastian; Planer-Friedrich, Britta; Kraemer, Ute; Kappler, Andreas

    2013-01-01

    Cadmium (Cd) is of environmental relevance as it enters soils via Cd-containing phosphate fertilizers and endangers human health when taken up by crops. Cd is known to associate with Fe(III) (oxyhydr)oxides in pH-neutral to slightly acidic soils, though it is not well understood how the interrelation of Fe and Cd changes under Fe(III)-reducing conditions. Therefore, we investigated how the mobility of Cd changes when a Cd-bearing soil is faced with organic carbon input and reducing conditions. Using fatty acid profiles and quantitative PCR, we found that both fermenting and Fe(III)-reducing bacteria were stimulated by organic carbon-rich conditions, leading to significant Fe(III) reduction. The reduction of Fe(III) minerals was accompanied by increasing soil pH, increasing dissolved inorganic carbon, and decreasing Cd mobility. SEM-EDX mapping of soil particles showed that a minor fraction of Cd was transferred to Ca- and S-bearing minerals, probably carbonates and sulfides. Most of the Cd, however, correlated with a secondary iron mineral phase that was formed during microbial Fe(III) mineral reduction and contained mostly Fe, suggesting an iron oxide mineral such as magnetite (Fe3O4). Our data thus provide evidence that secondary Fe(II) and Fe(II)/Fe(III) mixed minerals could be a sink for Cd in soils under reducing conditions, thus decreasing the mobility of Cd in the soil. PMID:24191747

  1. Bacterial patterning at the three-phase line of contact with microtextured alkanes.

    PubMed

    Nguyen, Song Ha; Webb, Hayden K; Mainwaring, David E; Mahon, Peter J; Crawford, Russell J; Ivanova, Elena P

    2015-01-01

    Aliphatic crystallites, characteristic of the eicosane and docosane components of naturally occurring lipids, were found to form microtextures that were structured by specific interactions with ordered graphite (HOPG) used as the underlying substratum, as confirmed by scanning electron microscopy (SEM) and fast Fourier transform (FFT) analysis. Confocal scanning laser microscopy (CLSM) showed highly directed bacterial alignment for two bacterial species (spherical and rod-shaped), reflecting the preferential orientation of the crystallite-air-water interfaces to give linear and triangular bacterial patterning. The mechanisms of bacterial attachment are demonstrated in terms of the balance between effective radial adhesional forces and the capillary forces resulting from the water contact angle of the bacteria at the three-phase line (TPL) of the lipid surface. It is suggested that these microtextured surfaces, which exhibit the ability to limit bacterial adhesion to a precise patterning at the lipid TPL, could be used as a means of controlling bacterial colonization. PMID:25959368

  2. Influence of graphite crystallinity on the microtexture of nano-polycrystalline diamond obtained by direct conversion

    NASA Astrophysics Data System (ADS)

    Ohfuji, Hiroaki; Okimoto, Shinsuke; Kunimoto, Takehiro; Isobe, Futoshi; Sumiya, Hitoshi; Komatsu, Kazuo; Irifune, Tetsuo

    2012-07-01

    Nano-polycrystalline diamond (NPD) is a super-hard pure polycrystalline aggregate of nano-diamonds and has a characteristic microtexture composed of a mixture of granular and lamellar crystals. We investigated the origin of the unique microtexture and the influence of the crystallinity of initial graphite sources on the resulting microtexture of NPDs. Polycrystalline graphite rods used for NPD synthesis were found to consist of coke-derived relatively large crystals and pitch-derived nanocrystalline particles. Upon conversion to NPD, the former are converted to cubic and hexagonal diamond mixtures by the martensitic transformation and left a lamellar texture behind, while the latter transform to granular nano-diamonds by diffusion-controlled nucleation and subsequent crystal growth, which initiate preferentially at lattice defects and crystal surfaces. A clear correlation between the crystallite size of the initial graphite and the grain size of the granular nano-diamonds in the NPDs was also found. Our results suggest that the average grain size and the relative abundance of lamellar domains in NPD can potentially be controlled by carefully choosing initial graphite sources based on their crystallinity.

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

    NASA Astrophysics Data System (ADS)

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

    2011-06-01

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

  4. Pore-scale study of the effect of secondary carbonate precipitation on the dissolution of primary minerals using the lattice Boltzmann method

    NASA Astrophysics Data System (ADS)

    Kang, Q.; Chen, L.; Carey, J. W.

    2013-12-01

    Reactive transport processes involving dissolution and/or precipitation are pervasive in Earth, energy, and environmental systems. One typical example is geologic sequestration of carbon dioxide. Among these reactive processes, it is commonly encountered that a second phase precipitates while the primary phase dissolves, and the precipitation and dissolution reactions are fully coupled with each other. In the case of mineral trapping of CO2, the primary silicate mineral dissolves due to a decrease of pH caused by the dissolution of CO2 into the solution; meanwhile the dissolved CO2 can react with cations to form a secondary precipitate of carbonate mineral. Although the effect of precipitation of secondary solid phase on the dissolution of the primary solid phase has been studied extensively, the results reported in the literature are often inconclusive and sometimes even contradict one another. The reason is that the coupled dissolution and precipitation processes are controlled by several factors whose contribution is difficult to ascertain, including the dissolution and precipitation reaction kinetics, temperature and pressure, pH and species concentration of the solution, physicochemical properties of the primary and secondary minerals, as well as the nucleation and crystal mechanisms of the precipitates, etc. In this study, a pore-scale (mesoscopic) model based on the lattice Boltzmann method (LBM) is developed to investigate the effects of secondary precipitation on the dissolution of the primary mineral. The model can predict coupled multiple physicochemical processes including fluid flow, mass transport, chemical reaction, dissolution, precipitation consisting of nucleation and crystal growth, as well as dynamical evolution of pore geometries. Effects of dissolution and precipitation reaction kinetics, molar volumes of primary and secondary minerals, initial powder size and surface roughness of the primary mineral, as well as nucleation and crystal growth mechanisms on the dissolution and precipitation processes are investigated in terms of rate and amount of dissolution and precipitation. Several types of dissolution and precipitation processes are identified based on the morphology and structure of the precipitates and on the extent to which the precipitates affect the dissolution of the primary mineral. Simulation results are also compared with existing experimental results. Depending on the conditions, the effect of the precipitates spans the full range of possible behavior from trivial changes to enhanced or reduced dissolution rates of the primary phase.

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

    NASA Astrophysics Data System (ADS)

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

    2014-03-01

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

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

    NASA Astrophysics Data System (ADS)

    Kempers, R.; Kerslake, S.

    2014-07-01

    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.

  7. Evolution of etching kinetics and directional transition of nanowires formed on pyramidal microtextures.

    PubMed

    Chen, Chia-Yun; Li, Liyi; Wong, Ching-Ping

    2014-01-01

    Two-scale roughened silicon (Si) textures are considered promising architectures for versatile applications because of their excellent self-cleaning, light-trapping, and biosensing capacities. In this study, we explore the directional control of nanowires formed on pyramidal microtextures through a single-step metal-assisted chemical etching (MACE). The measured current density of Si dissolution at catalytic etching enables quantitative monitoring of the etching kinetics of nanowire formation. The preferential orientation of fabricated nanowires on {111}-plane pyramidal textures was found to positively correlate with the molar ratio of [AgNO3 ] to ([AgNO3 ]+[HF]), referred to as ?. A distinct transition from <100> to <111> axial directions at ??0.2 and ?=0.07, respectively, was revealed. The <111>-oriented nanowires on the pyramidal microtextures exhibited an excellent antireflection performance, with a reflectivity as low as 1.2% at 600 nm. The results of this study may aid the design for the development of high-performance Si-based optoelectronic devices. PMID:24127312

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

    SciTech Connect

    Quey, R.; Driver, J.H.

    2011-12-15

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

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

    PubMed

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

    2003-11-01

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

  10. The influence of microtextured basal lamina analog topography on keratinocyte function and epidermal organization.

    PubMed

    Downing, Brett R; Cornwell, Kevin; Toner, Mehmet; Pins, George D

    2005-01-01

    The rational design of future bioengineered skin substitutes requires an understanding of the mechanisms by which the three-dimensional microarchitecture of tissue scaffolds modulates keratinocyte function. Microtextured basal lamina analogs were developed to investigate the relationship between the characteristic topography at the dermal-epidermal interface of native skin and keratinocyte function. Microfabrication techniques were used to create master patterns, negative replicates, and collagen membranes with ridges and channels of length scales (e.g., grooves of 50-200 microm in depth and width) similar to the invaginations found in basal lamina at the dermal-epidermal junction of native skin. Keratinocytes were seeded on the surfaces of basal lamina analogs, and histological analyses were performed after 7 days of tissue culture at the air-liquid interface. The keratinocytes formed a differentiated and stratified epidermis that conformed to the features of the microtextured membranes. Morphometric analyses of immunostained skin equivalents suggest that keratinocyte stratification and differentiation increases as channel depth increases and channel width decreases. This trend was most pronounced in channels with the highest depth-to-width ratios (i.e., 200 microm deep, 50 microm wide). It is anticipated that the findings from these studies will elucidate design parameters to enhance the performance of future bioengineered skin substitutes. PMID:15543632

  11. Heavy minerals in surficial sediments from lower Cook Inlet, Alaska

    USGS Publications Warehouse

    Wong, F.L.

    1984-01-01

    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.

  12. Geochemical, microtextural and petrological studies of the Samba prospect in the Zambian Copperbelt basement: a metamorphosed Palaeoproterozoic porphyry Cu deposit.

    NASA Astrophysics Data System (ADS)

    Master, Sharad; Mirrander Ndhlovu, N.

    2015-04-01

    Ever since Wakefield (1978, IMM Trans., B87, 43-52) described a porphyry-type meta-morphosed Cu prospect, the ca 50 Mt, 0.5% Cu Samba deposit (12.717°S, 27.833°E), hosted by porphyry-associated quartz-sericite-biotite schists in northern Zambia, there has been controversy about its origin and significance. This is because it is situated in the basement to the world's largest stratabound sediment-hosted copper province, the Central African Copperbelt, which is hosted by rocks of the Neoproterozoic Katanga Supergroup. Mineralization in the pre-Katangan basement has long played a prominent role in ore genetic models, with some authors suggesting that basement Cu mineralization may have been recycled into the Katangan basin through erosion and redeposition, while others have suggested that the circulation of fluids through Cu-rich basement may have leached out the metals which are found concentrated in the Katangan orebodies. On the basis of ca 490-460 Ma Ar-Ar ages, Hitzman et al. (2012, Sillitoe Vol., SEG Spec. Publ., 16, 487-514) suggested that Samba represents late-stage impregnation of copper mineralization into the basement, and that it was one of the youngest copper deposits known in the Central African Copperbelt. If the Samba deposit really is that young, then it would have post-dated regional deformation and metamorphism (560-510 Ma), and it ought to be undeformed and unmetamorphosed. The Samba mineralization consists of chalcopyrite and bornite, occurring as disseminations, stringers and veinlets, found in a zone >1 km along strike, in steeply-dipping lenses up to 10m thick and >150m deep. Our new major and trace element XRF geochemical data (14 samples) show that the host rocks are mainly calc-alkaline metadacites. Cu is correlated with Ag (Cu/Ag ~10,000:1) with no Au or Mo. Our study focused on the microtextures and petrology of the Samba ores. We confirm that there is alteration of similar style to that accompanying classical porphyry Cu mineralization, including potassic (biotite+sericite+ quartz), propylitic (clinozoisite+chlorite+saussuritized plagioclase), phyllic (sericite+quartz+ pyrite+hydromuscovite/illite) and argillic (kaolinite+chlorite+dolomite) alteration. The clays were identified with XRD. All the rocks show penetrative deformational textures and fabrics. Our textural studies show that phyllic zone pyrite crystals have quartz-rich pressure shadows, and they predate all phases of deformation. Similarly, in the potassic zone, fracture-controlled biotite stringers in particular orientations are deformed, and partly replaced by chlorite, again showing their pre-deformational, pre-metamorphic origin. Copper sulfide-bearing quartz veinlets are deformed. Many of the alteration assemblages containing biotite or sericite have been deformed into crenulated schists, showing that they were formed early in the deformation history. Coupled with the dating of a Samba metavolcanic rock at 1964±12 Ma (Rainaud et al., 2005, JAES, 42, 1-31), we regard the Samba deposit as a metamorphosed Palaeoproterozoic porphyry-type Cu deposit, which has undergone deformation, and retrograde metamorphism of its alteration assemblages, during the Neoproterozoic Lufilian Orogeny, followed by post-tectonic cooling, which occurred throughout the Copperbelt at about 480±20 Ma. Samba, together with the Mkushi deposits, is part of a long-lived (>100 Ma) Palaeoproterozoic porphyry-Cu province in the Zambian Copperbelt basement, and ore genetic theories for the Copperbelt mineralization must now seriously take this into account.

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

    PubMed

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

    2013-05-01

    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--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

  14. Weathering of sulfidic shale and copper mine waste: Secondary minerals and metal cycling in Great Smoky Mountains National Park, Tennessee, and North Carolina, USA

    USGS Publications Warehouse

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

    2003-01-01

    Metal cycling via physical and chemical weathering of discrete sources (copper mines) and regional (non-point) sources (sulfide-rich shale) is evaluated by examining the mineralogy and chemistry of weathering products in Great Smoky Mountains National Park, Tennessee, and North Carolina, USA. The elements in copper mine waste, secondary minerals, stream sediments, and waters that are most likely to have negative impacts on aquatic ecosystems are aluminum, copper, zinc, and arsenic because these elements locally exceed toxicity guidelines for surface waters or for stream sediments. Acid-mine drainage has not developed in streams draining inactive copper mines. Acid-rock drainage and chemical weathering processes that accompany debris flows or human disturbances of sulfidic rocks are comparable to processes that develop acid-mine drainage elsewhere. Despite the high rainfall in the mountain range, sheltered areas and intermittent dry spells provide local venues for development of secondary weathering products that can impact aquatic ecosystems.

  15. Shock-thermal history of Kavarpura IVA iron: Evidences from microtextures and nickel profiling

    NASA Astrophysics Data System (ADS)

    Ray, Dwijesh; Ghosh, S.; Murty, S. V. S.

    2015-11-01

    We classify Kavarpura iron (fell in August, 2006, in Rajasthan, India), an inclusion-free member of high-Ni IVA group. Widmansttten pattern and finger-cellular plessites textures characteristic of IVA group are present in Kavarpura. Symmetric and asymmetric textural zoning within the cloudy taenite and plessite refer to long term martensitisation process with mean metallographic cooling rate of 200 C/Ma. Imprints of variable shock pressure domains (Neumann bands and shock hatched ? kamacite) suggest alteration by up to 600 kb shock pressure. Degeneration of cellular plessites, bending of finger plessites and plastic flowage of taenites bear textural evidences corresponding to post-shock annealing which is further confirmed by Ni profiles across the cloudy taenites and plessites under high shock pressure domains. Based on microtextural evidences and Ni profiling, we suggest Kavarpura had cooled at steady state and subsequently suffered multiple impacts.

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

    NASA Technical Reports Server (NTRS)

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

    2005-01-01

    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.

  17. Microtexture of constituent phases in a heavily warm- rolled and annealed duplex stainless steel

    NASA Astrophysics Data System (ADS)

    Zaid, M.; Bhattacharjee, P. P.

    2015-04-01

    Evolution of microtexture during isothermal annealing of a heavily warm-rolled Fe- 0.08%C-24.18%Cr-10.5%Ni duplex stainless steel (DSS) having approximately equal volume fraction of ferrite and austenite was investigated in the present work. The DSS was warm-rolled to ∼90% reduction in thickness at three different temperatures, namely, 225°C, 425°C and 625°C followed by isothermal annealing at 1175°C for different length of time. Austenite showed pure metal or copper type texture at different warm-rolling temperatures. In contrast, the texture of ferrite in different warm-rolled DSS revealed the presence of RD (RD//<110>) and ND (ND//<111>) fibers. The annealing texture of austenite showed retention of the deformation texture components while ferrite revealed strong RD-fiber.

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

    USGS Publications Warehouse

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

    2005-01-01

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

  19. Quartz microtextures and microstructures owing to deformation of glaciolacustrine sediments in the northern Venezuelan Andes

    NASA Astrophysics Data System (ADS)

    Mahaney, W. C.; Dirszowsky, R. W.; Milner, M. W.; Menzies, J.; Stewart, A.; Kalm, V.; Bezada, M.

    2004-01-01

    Glaciolacustrine sediments, ranging in age from Early to Late Mrida (Wisconsinan) in sections in the northern Venezuelan Andes near Pedregal, were studied to assess the effect of small-scale folding and faulting on the surface microtextures of individual grains. At site PED5, faulting of sediments beneath 35 m of Middle to Late Mrida glaciolacustrine, glaciofluvial and probable till deposits, has resulted in a maximum displacement of 1 m and many crushed sand grains are found along the shear zone. These dominantly quartz particles are typically smoothed and/or faceted with surface skins split from parent grains to produce adhering blade or wafer-shaped coarse silts. Faulting with displacement of< 40 cm occurs in Late Mrida glaciolacustrine beds at sites PED13 and PED11, beneath ca. 1-5 m of sediment and is thought to result from the removal of lateral support during valley erosion and possibly seismic disturbance. Associated sediments exhibit a greater incidence of small-scale fold structures and convoluted bedding but with similar numbers and types of crushed grains. All of the fault traces examined exhibit microstructural modifications, including microfaulting, folding and multiple domains associated with fluidisation and liquefaction. The microtextures described are distinct from those produced by glacial or glaciofluvial transport processes and potentially may be used to infer glaciotectonic or other post-depositional disturbance of sediments. Rare euhedral quartz grains with distorted crystallographic axes may derive from the shear zone of the regional transform Bocon Fault, although many of these grains appear to be overprinted by glacial and/or recent deformation processes. Copyright

  20. Oxygen Isotope and Microtextural Biosignatures of Hydroxylapatite in Karst Caves of South Korea

    NASA Astrophysics Data System (ADS)

    Chang, S.; Blake, R. E.; Kim, S.

    2006-05-01

    Hydroxylapatite is precipitating in restricted areas of bat habitats in three karst caves (Gosu, Sungryu, and Ssang caves) in S. Korea. It covers the surfaces of carbonate speleothem and host rock forming a 0.1 to 0.5 mm thick crust. In order to elucidate the process of formation of this hydroxylapatite crust, the O isotope composition of phosphate (?18OP), in the crust and in bat guano, as well as the O isotope compositions of calcite carbonate (?18OC) in speleothems, and of dripping water (?18OW) were determined together with mineralogical and textural analyses. The ?18OP values of the crust (approx. 13 permil) are between ?18OP values of bat guano (approx. 21 permil) and ?18OW values of dripping water (approx. -9.5 permil). These ?18O values and a close relation between crust distribution and bat habitat indicate that bat excretion provides phosphate for formation of the hydroxylapatite crust. The ?18OP values of the crust are in temperature-dependent isotopic equilibrium with dripping water. This suggests that the phosphate has been metabolized and has undergone oxygen isotope exchange with dripping water by enzyme-catalyzed reactions at low temperatures (13 to 16C). The ?18OC values of speleothem calcite below the crust are approx. 9 permil higher than the ?18OP values of the crust. This suggests that both speleothem and crust have formed in oxygen isotopic equilibrium with the dripping water as a result of enzyme-catalyzed reactions. Electron microscopy shows that sulfur-bearing filamentous bacteria are distributed on and within the crust. Also, four different microtextures (colloform, sea- and-island, cellular, and reticulate textures) are observed in the crust, and are produced by the distribution patterns of bacteria. Thus, both isotopic and microtextural signatures reflect bacterially-mediated biomineralization of hydroxylapatite in karst cave ecosystems.

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

    NASA Astrophysics Data System (ADS)

    Yingst, R. A.; Schmidt, M. E.; Herkenhoff, K. E.; Mittlefehldt, D. W.; Athena Science Team

    2007-07-01

    Microtextural analysis of Algonquin-class and Home Plate rocks indicates a genetic relationship between these two geochemically disparate classes. We conclude that a hydrovolcanic origin for both rock classes is likely.

  2. Reaction path modelling used to explore the relationship between secondary mineral precipitation and low Si content in the meltwaters of a polythermal surge-type glacier

    NASA Astrophysics Data System (ADS)

    Crompton, J. W.; Flowers, G. E.; Kirste, D. M.; Hagedorn, B.

    2014-12-01

    The subglacial chemical weathering environment is characterized by low temperatures and the hydrolysis and carbonation of freshly comminuted mineral surfaces. Such conditions motivate the hypothesis that relatively low silica fluxes should be found in glacierized basins. Additionally, it is often assumed that glacier meltwaters are far from saturation and that the water chemistry is controlled solely by the dissolution of primary silicates and trace quantities of sulphide and carbonate minerals. Alternatively, we propose that the formation of secondary minerals and precipitates in the delayed drainage system play an important role in controlling the low silica fluxes observed in subglacial envrionments. Borehole and proglacial meltwater samples were collected from a polythermal surge-type glacier overlying granodiorite bedrock in the St. Elias Mountains of Yukon, Canada. The meltwater chemistry, along with the mineralogy of the bedrock and suspended sediments indicate the presence of mineral precipitation accompanied by substantial basal freeze-on. This is supported by field evidence of debris rich basal ice at the terminus and at the base of a borehole. The surplus of Cl- above the supraglacial input is used to calculate the amount of basal freeze-on in the delayed drainage system, and the amount of mixing between the delayed and fast drainage systems. We use Geochemist's Workbench for reaction path modelling with a focus on the silica composition to simulate the chemical evolution of glacial meltwater from (1) the initial water rock contact, (2) basal freeze on, and (3) mixing and post mixing reactions. Unless there is a substantial degree of non-stoichiometric dissolution, we find that the observed proglacial water chemistry at the terminus is largely controlled by the hydrochemistry of water in the delayed drainage system. Lastly, we use this model to explore the relationship between the proglacial water chemistry and the daily glacier surface velocities for the period of July, 2013, with an eye to identifying a relationship between water chemistry and short-term glacier dynamics.

  3. The responses to surface wettability gradients induced by chitosan nanofilms on microtextured titanium mediated by specific integrin receptors

    PubMed Central

    Park, Jung Hwa; Wasilewski, Christine E.; Almodovar, Noelia; Olivares-Navarrete, Rene; Boyan, Barbara D.; Tannenbaum, Rina; Schwartz, Zvi

    2013-01-01

    Microtexture and chemistry of implant surfaces are important variables for modulating cellular responses. Surface chemistry and wettability are connected directly. While each of these surface properties can influence cell response, it is difficult to decouple their specific contributions. To address this problem, the aims of this study were to develop a surface wettability gradient with a specific chemistry without altering micron scale roughness and to investigate the role of surface wettability on osteoblast response. Microtextured sandblasted/acid-etched (SLA, Sa = 3.1 μm) titanium disks were treated with oxygen plasma to increase reactive oxygen density on the surface. At 0, 2, 6, 10, and 24 h after removing them from the plasma, the surfaces were coated with chitosan for 30 min, rinsed and dried. Modified SLA surfaces are denoted as SLA/h in air prior to coating. Surface characterization demonstrated that this process yielded differing wettability (SLA0 < SLA2 < SLA10 < SLA24) without modifying the micron scale features of the surface. Cell number was reduced in a wettability-dependent manner, except for the most water-wettable surface, SLA24. There was no difference in alkaline phosphatase activity with differing wettability. Increased wettability yielded increased osteocalcin and osteoprotegerin production, except on the SLA24 surfaces. mRNA for integrins α1, α2, α5, β1, and β3 was sensitive to surface wettability. However, surface wettability did not affect mRNA levels for integrin α3. Silencing β1 increased cell number with reduced osteocalcin and osteoprotegerin in a wettability-dependent manner. Surface wettability as a primary regulator enhanced osteoblast differentiation, but integrin expression and silencing β1 results indicate that surface wettability regulates osteoblast through differential integrin expression profiles than microtexture does. The results may indicate that both microtexture and wettability with a specific chemistry have important regulatory effects on osseointegration. Each property had different effects, which were mediated by different integrin receptors. PMID:22835642

  4. Wetting state on hydrophilic and hydrophobic micro-textured surfaces: Thermodynamic analysis and X-ray visualization

    SciTech Connect

    Yu, Dong In; Kwak, Ho Jae; Doh, Seung Woo; Park, Hyun Sun Kiyofumi, Moriyama; Kang, Hie Chan; Ahn, Ho Seon; Kim, Moo Hwan

    2015-04-27

    In this study, the wetting state on hydrophobic and hydrophilic micro-textured surfaces was investigated. High spatial resolution synchrotron X-ray radiography was used to overcome the limitations in visualization in previous research and clearly visualize the wetting state for each droplet under quantified surface conditions. Based on thermodynamic characteristics, a theoretical model for wetting state depending on the chemical composition (intrinsic contact angle) and geometrical morphology (roughness ratio) of the surfaces was developed.

  5. Commentary: assessment of past infiltration fluxes through Yucca Mountain on the basis of the secondary mineral record-is it a viable methodology?

    PubMed

    Dublyansky, Yuri V; Smirnov, Sergey Z

    2005-04-01

    Two papers recently published in the Journal of Contaminant Hydrology by Marshall et al. [Marshall, B.D., Neymark, L.A., Peterman, Z.E., 2003. Estimation of past seepage volumes from calcite distribution in the Topopah Spring Tuff, Yucca Mountain, Nevada. J. Contam. Hydrol. 62-63, 237-247] and Xu et al. [Xu, T., Sonnenthal, E., Bodvarsson, G., 2003. A reaction-transport model for calcite precipitation and evaluation of infiltration fluxes in unsaturated fractured rock. J. Contam. Hydrol. 64, 113-127] attempt to assess past volumes of seepage and infiltration fluxes through the vadose zone of Yucca Mountain, Nevada, on the basis of the modeling of the spatial distribution of secondary calcite. In this commentary, we argue that the employed methodology is not viable. In addition, the thermal boundary conditions used in simulations do not correspond to the temperatures of the mineral forming fluids established on the basis of the fluid inclusion studies. PMID:15763356

  6. Nutritional secondary hyperparathyroidism in two cats: evaluation of bone mineral density with dual-energy X-ray absorptiometry and computed tomography.

    PubMed

    Dimopoulou, M; Kirpensteijn, J; Nielsen, D H; Buelund, L; Hansen, M S

    2010-01-01

    Two three-month-old, intact female Abyssinian cats were presented with a history of lameness, constipation and ataxia. The cats had been fed a diet composed almost exclusively of meat. Both showed severe osteopenia and multiple pathological fractures on radiography. Following euthanasia of the more severely affected cat, postmortem examination revealed changes consistent with nutritional secondary hyperparathyroidism and fibrous osteodystrophy, such as cortical thinning, massive connective tissue invasion in the diaphysis of long bones, and hypertrophy of the chief cells in both parathyroid glands. After introducing a balanced commercial diet to the surviving cat, bone mineralisation improved from the baseline value, and at subsequent examinations at three, six and 22 weeks later, as indicated by bone mineral density measurements obtained by dual-energy X-ray absorptiometry and computed tomography. PMID:19997669

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

    PubMed

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

    2013-12-01

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

  8. 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

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

    2010-06-15

    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.

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

    SciTech Connect

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

    1989-07-01

    Concentrations of {sup 18}O and deuterium in ground waters beneath the Handford 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 filing vugs and fractures in the basalts, which are used to approximate the {sup 18}O content of ground water at the time the mineral assemblage formed. A fossil profile of {delta}{sup 18}O values projected for ground water in a 1500 m vertical section beneath the reservation suggest 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 {sup 18}O 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 {sup 18}O associated with the progressive uplift of the Cascade Range since the middle Miocene.

  10. DOE FG02-03ER63557: Final Technical Report: Reactivity of Primary Soil Minerals and Secondary Precipitates Beneath Leaking Hanford Waste Tanks

    SciTech Connect

    Kathryn L. Nagy

    2009-05-04

    The purpose of the project was to investigate rates and mechanisms of reactions between primary sediment minerals and key components of waste tank solutions that leaked into the subsurface at the Hanford Site. Results were expected to enhance understanding of processes that cause (1) changes in porosity and permeability of the sediment and resultant changes in flow paths of the contaminant plumes, (2) formation of secondary precipitates that can take up contaminants in their structures, and (3) release of mineral components that can drive redox reactions affecting dissolved contaminant mobility. Measured rates can also be used directly in reactive transport models. Project tasks included (1) measurement of the dissolution rates of biotite mica from low to high pH and over a range of temperature relevant to the Hanford subsurface, (2) measurement of dissolution rates of quartz at high pH and in the presence of dissolved alumina, (3) measurement of the dissolution rates of plagioclase feldspar in high pH, high nitrate, high Al-bearing solutions characteristic of the BX tank farms, (4) incorporation of perrhenate in iron-oxide minerals as a function of pH, and (5) initiation of experiments to measure the formation of uranium(VI)-silicate phases under ambient conditions. Task 2 was started under a previous grant from the Environmental Management Science Program and Task 4 was partially supported by a grant to the PI from the Geosciences Program, Office of Basic Energy Sciences. Task 5 was continued under a subsequent grant from the Environmental Remediation Sciences Program, Office of Biological and Environmental Research.

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

    USGS Publications Warehouse

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

    2003-01-01

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

  12. 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

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

    2006-01-01

    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.

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

    SciTech Connect

    Evans, Brent; Olson, Arlin; Mason, J. Bradley; Ryan, Kevin; Jantzen, Carol; Crawford, Charles

    2012-07-01

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

  14. Evaluation of Bone Height and Bone Mineral Density Using Cone Beam Computed Tomography After Secondary Bone Graft in Alveolar Cleft.

    PubMed

    Zhang, Dai-zun; Xiao, Wen-lin; Zhou, Rong; Xue, Ling-fa; Ma, Long

    2015-07-01

    The purpose of this study was to assess the optimal timing of subsequent dental implant placement and orthodontics after alveolar bone grafting (ABG) in patients with unilateral complete clefts of the alveolar process. Iliac bone graft surgery was performed on 60 patients. Bone mineral density (BMD) and height of the ABG areas were assessed using cone beam computed tomography at 3 and 6 months postoperatively. The heights of the labial and palatal bone graft areas were classified using the modified Bergland classification. The study found that there was no change in BMD between 3 months (mean ± SD: 406.51 ± 71.28 Hounsfield units [HU]) and 6 months (409.53 ± 46.37 HU; P = 0.381). Significant changes in the distribution of bone height classifications were observed in the labial and palatal sides of the ABG between 3 and 6 months (P = 0.025 for labial bone height, P = 0.008 for palatal bone height). These results indicate that the alveolar density remained stable between 3 and 6 months, whereas bone height level declined during that period after ABG, the latter indicating bone graft absorption over time. It is, therefore, suggested that subsequent orthodontic or dental implants be placed 3 months after ABG rather than at 6 months or later. PMID:26114510

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

    PubMed Central

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

    2008-01-01

    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

  16. Metal nanoparticle-enhanced photocurrent in GaAs photovoltaic structures with microtextured interfaces.

    PubMed

    Dmitruk, Nicolas L; Borkovskaya, Olga Yu; Mamontova, Iryna B; Mamykin, Sergii V; Malynych, Sergii Z; Romanyuk, Volodymyr R

    2015-01-01

    The photocurrent enhancement effect caused by Au and Ag nanoparticles for GaAs-based photovoltaic structures of surface barrier or p-n junction type with microtextured interfaces has been investigated in dependence on the conditions of nanoparticles deposition and, respectively, on the shape and local dielectric environment of obtained nanoparticle arrays. Three nanoparticle deposition methods have been checked: 1) photoinduced chemical deposition of Au from aqueous AuCl3 solution forming nanowires on the ridges of quasigrating-type surface microrelief, 2) deposition of Ag nanoparticles from colloidal suspension on the GaAs substrate covered with poly(vinylpyridine), and 3) drop and dry deposition of Au/SiO2 core-shell nanoparticles from aqueous colloid solution. The comprehensive investigation of optical reflectance, photoelectric, and electrical characteristics of the fabricated barrier structures has shown the highest photovoltaic parameters for surface microrelief of quasigrating-type and electroless Au nanoparticle deposition. The analysis of characteristics obtained allowed us also to define the mechanisms of the total photocurrent enhancement. PMID:25852368

  17. Metal nanoparticle-enhanced photocurrent in GaAs photovoltaic structures with microtextured interfaces

    NASA Astrophysics Data System (ADS)

    Dmitruk, Nicolas L.; Borkovskaya, Olga Yu; Mamontova, Iryna B.; Mamykin, Sergii V.; Malynych, Sergii Z.; Romanyuk, Volodymyr R.

    2015-02-01

    The photocurrent enhancement effect caused by Au and Ag nanoparticles for GaAs-based photovoltaic structures of surface barrier or p-n junction type with microtextured interfaces has been investigated in dependence on the conditions of nanoparticles deposition and, respectively, on the shape and local dielectric environment of obtained nanoparticle arrays. Three nanoparticle deposition methods have been checked: 1) photoinduced chemical deposition of Au from aqueous AuCl3 solution forming nanowires on the ridges of quasigrating-type surface microrelief, 2) deposition of Ag nanoparticles from colloidal suspension on the GaAs substrate covered with poly(vinylpyridine), and 3) drop and dry deposition of Au/SiO2 core-shell nanoparticles from aqueous colloid solution. The comprehensive investigation of optical reflectance, photoelectric, and electrical characteristics of the fabricated barrier structures has shown the highest photovoltaic parameters for surface microrelief of quasigrating-type and electroless Au nanoparticle deposition. The analysis of characteristics obtained allowed us also to define the mechanisms of the total photocurrent enhancement.

  18. Microtextured metals for stray-light suppression in the Clementine startracker

    NASA Astrophysics Data System (ADS)

    Johnson, E. A.

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

  19. Microtextured Omniphobic Surfaces by Solution Spraying of Fluorodecyl POSS/PMMA Blends

    NASA Astrophysics Data System (ADS)

    Srinivasan, Siddarth; McKinley, Gareth; Cohen, Robert

    2012-02-01

    We present a simple technique to prepare various micro-structured surfaces by spray coating a polymer blend of poly(methyl methacrylate) (PMMA) and the low surface energy molecule 1H,1H,2H,2H-heptadecafluorodecyl polyhedral oligomeric silsesquioxane (fluorodecyl POSS) using an air brush with a pressurized nitrogen stream. The sprayed surface morphology can be systematically tuned from a spherical or corpuscular microstructure to beads-on-string and a fiborous non-woven mesh, nearly identical to structures obtained by electrospinning similar PMMA/fluorodecyl POSS solutions. A semi-empirical framework is used to develop an operating diagram to predict the surface morphology produced during the simple spraying technique based on the polymer solution concentration and molecular weight. The presence of the low-surface-energy POSS molecules at the surface combined with the re-entrant microtextured features confers super-liquid-repellent properties to the spray-coated substrate, which are characterized by advancing and receding contact angle measurements with liquids of a range of surface tensions.

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

    PubMed

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

    2012-12-01

    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

  1. Mineralogical and microtextural characterization of ``gel-zircon`` from the Manibay uranium mine, Kazakhstan

    SciTech Connect

    Helean, K.B.; Ewing, R.C.; Burakov, B.E.; Anderson, E.B.; Strykanova, E.E.; Ushakov, S.V.

    1997-12-31

    Gel-zircon, an unusual Zr-silicate phase from the Manibay uranium mine, northern Kazakhstan, was studied using X-ray diffraction (XRD), electron microprobe energy dispersive X-ray spectroscopy (EDS) and high resolution transmission electron microscopy (HRTEM). XRD results indicate that gel-zircon is mostly amorphous and occurs with numerous impurity phases. Microprobe EDS results indicate a UO{sub 2} content up to 9.14 wt.% HRTEM images revealed that the microtexture of gel-zircon consists of nanocrystallites of zircon, 2--10 nm in size, in a dominantly amorphous matrix. Despite the U-Pb age of 420 {+-} 25 my and the lack of significant crystallinity, the gel-zircon is an apparently chemically durable phase. Leaching of uranium ores which contain gel-zircon as the major U-bearing phase is impossible using existing uranium plant technologies. The alpha-decay dose, 2.64 displacements per atom (dpa), corresponding to the age of gel-zircon is much higher than that (0.5 dpa) required to cause metamictization of crystalline zircon. However, the morphology of gel-zircon which occurs as veins up to 5 mm thick and tens of mm long does not indicate initial crystallinity. Initially crystalline natural zircons often preserve their crystal morphology after metamictization. This amorphous phase is analogous to the highly damaged state characteristic of zircon proposed as a waste form for the disposition of excess weapons plutonium.

  2. Microtextured metals for stray-light suppression in the Clementine startracker

    NASA Technical Reports Server (NTRS)

    Johnson, E. A.

    1993-01-01

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

  3. Time-temperature evolution of microtextures and contained fluids in a plutonic alkali feldspar during heating

    NASA Astrophysics Data System (ADS)

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

    2010-08-01

    Microtextural changes brought about by heating alkali feldspar crystals from the Shap granite, northern England, at atmospheric pressure, have been studied using transmission and scanning electron microscopy. A typical unheated phenocryst from Shap is composed of about 70 vol% of tweed orthoclase with strain-controlled coherent or semicoherent micro- and crypto-perthitic albite lamellae, with maximum lamellar thicknesses <1 ?m. Semicoherent lamellae are encircled by nanotunnel loops in two orientations and cut by pull-apart cracks. The average bulk composition of this microtexture is Ab27.6Or71.8An0.6. The remaining 30 vol% is deuterically coarsened, microporous patch and vein perthite composed of incoherent subgrains of oligoclase, albite and irregular microcline. The largest subgrains are ~3 ?m in diameter. Heating times in the laboratory were 12 to 6,792 h and T from 300C into the melting interval at 1,100C. Most samples were annealed at constant T but two were heated to simulate an 40Ar/39Ar step-heating schedule. Homogenisation of strain-controlled lamellae by Na?K inter-diffusion was rapid, so that in all run products at >700C, and after >48 h at 700C, all such regions were essentially compositionally homogeneous, as indicated by X-ray analyses at fine scale in the transmission electron microscope. Changes in lamellar thickness with time at different T point to an activation energy of ~350 kJmol-1. A lamella which homogenised after 6,800 h at 600C, therefore, would have required only 0.6 s to do so in the melting interval at 1,100C. Subgrains in patch perthite homogenised more slowly than coherent lamellae and chemical gradients in patches persisted for >5,000 h at 700C. Homogenisation T is in agreement with experimentally determined solvi for coherent ordered intergrowths, when a 50-100C increase in T for An1 is applied. Homogenisation of lamellae appears to proceed in an unexpected manner: two smooth interfaces, microstructurally sharp, advance from the original interfaces toward the mid-line of each twinned, semicoherent lamella. In places, the homogenisation interfaces have shapes reflecting the local arrangements of nanotunnels or pull-aparts. Analyses confirm that the change in alkali composition is also relatively sharp at these interfaces. Si-Al disordering is far slower than alkali homogenisation so that tweed texture in orthoclase, tartan twinning in irregular microcline, and Albite twins in albite lamellae and patches persisted in all our experiments, including 5,478 h at 700C, 148 h at 1,000C and 5 h at 1,100C, even though the ensemble in each case was chemically homogeneous. Nanotunnels and pull-aparts were modified after only 50 min at 500C following the simulated 40Ar/39Ar step-heating schedule. New features called slots developed away from albite lamellae, often with planar traces linking slots to the closest lamella. Slot arrays were often aligned along ghost-like regions of diffraction contrast which may mark the original edges of lamellae. We suggest that the slot arrays result from healing of pull-aparts containing fluid. At 700C and above, the dominant defects were subspherical bubbles, which evolved from slots or from regions of deuteric coarsening. The small degree of partial melting observed after 5 h at 1,100C was often in the vicinity of bubbles. Larger micropores, which formed at subgrain boundaries in patch perthite during deuteric coarsening, retain their shape up to the melting point, as do the subgrain boundaries themselves. It is clear that modification of defects providing potential fast pathways for diffusion in granitic alkali feldspars begins below 500C and that defect character progressively changes up to, and beyond, the onset of melting.

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

    PubMed

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

    2009-09-01

    A three-dimensional (3D) structure comprising precisely defined micro-architecture 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 microm 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

  5. 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

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

    2012-02-02

    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.

  6. Micro-textures and in situ sulfur isotopic analysis of spheroidal and zonal sulfides in the giant Jinding Zn-Pb deposit, Yunnan, China: Implications for biogenic processes

    NASA Astrophysics Data System (ADS)

    Xue, Chunji; Chi, Guoxiang; Fayek, Mostafa

    2015-05-01

    The Jinding deposit in Yunnan, southwest China, is the largest sandstone- and conglomerate-hosted Zn-Pb deposit in the world. In this paper, we report various micro-textures of spheroidal and zonal sulfides, such as pellet-shaped and colloform aggregates of pyrite and sphalerite, from the deposit and interpret them to be possibly related to micro-colonies of sulfate reducing bacteria, probably supporting an in situ BSR hypothesis. Micro-scale sulfur isotope analysis in different parts of the spheroidal and zonal sulfide aggregates, using secondary ion mass spectrometry (SIMS), revealed ?34S (VCDT) values as low as -48.4 for sulfides formed in the early-main stage disseminated ores in the western part of the deposit, possibly suggesting maximum sulfur isotopic fractionation through BSR. Relatively elevated ?34S (VCDT) values (-7.7 to -34.8, mainly from -10 to -20) for the late-stage, cavity-filling ores in the eastern part of the deposit, are interpreted to be possibly related to elevated temperatures close to the hydrothermal conduit and elevated ?34S values of the remaining sulfates resulting from the preceding BSR processes. The apparent discrepancy between the low temperatures required for BSR and the high temperatures indicated by fluid inclusions (>120 C) may be reconciled through invoking episodic influx of ore-forming hydrothermal fluids into a shallow, relatively cool environment. It is proposed that the host rocks of the Jinding deposit have not been buried to great depths (?1 km), which, combined with the availability of hydrocarbons in the Jinding dome (a paleo-oil and gas reservoir), provides an ideal environment for BSR. Episodic influx of metal-carrying hydrothermal fluids temporarily and locally suppressed BSR and promoted thermo-chemical sulfate reduction (TSR), resulting in deposit- and micro-scale variations of ?34S.

  7. Effect of pad surface micro-texture on dishing and erosion during shallow trench isolation chemical mechanical planarization

    NASA Astrophysics Data System (ADS)

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

    2014-08-01

    The effect of pad surface micro-texture on dishing and erosion during shallow trench isolation (STI) chemical mechanical planarization was investigated. To generate different pad surface micro-textures, a 3M A2810 disc (3M) and a Mitsubishi Materials Corporation disc (MMC) were used to condition a Dow IC1000 K-groove pad. For each disc, 200-mm blanket TEOS wafers and SKW3-2 STI wafers were polished. Results showed that the two discs generated similar blanket wafer removal rates, while the MMC disc generated significantly higher dishing and erosion compared to the 3M disc during patterned wafer polishing. Pad surface topography was analyzed using laser confocal microscopy after patterned wafer polishing. Results showed that the MMC disc generated a pad surface with significantly higher mean pad summit curvatures than the 3M disc. As the MMC disc generated more and sharper pad asperities, it resulted in higher dishing and erosion as these sharp asperities make greater direct contact with the down features.

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

    PubMed

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

    2011-11-15

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

  9. Pan-Spectral Analysis of Classic Martian Low-Albedo Regions: Updates on the Nature and Distribution of Primary and Secondary Mineral Phases

    NASA Astrophysics Data System (ADS)

    Salvatore, M. R.; Mustard, J. F.; Head, J. W.; Rogers, D.

    2013-12-01

    In this study, we investigate the primary and secondary mineralogy of martian low-albedo regions using a combination of visible/near-infrared (VNIR) reflectance and thermal infrared (TIR) emission datasets. TIR data were originally derived using the Thermal Emission Spectrometer (TES) instrument by [1,2], who interpreted these low-albedo regions to contain variable amounts of both basaltic and high-silica components; however, the nature of these high-silica phases remains uncertain, and both primary (e.g., volcanic glass) and secondary (e.g., hydrated alteration minerals) origins have been proposed. The mineralogical signatures of the evolving martian geologic, hydrologic, and climatic systems are recorded in these low-albedo regions, making the characterization of the identified high-silica phases critical towards better understanding the history of Mars. Consequently, we have completed a pan-spectral (VNIR and TIR) investigation of the nine low-albedo regions characterized by [2] in order to further constrain the composition of these martian landscapes. We derived regional VNIR spectra using Observatoire pour la Minralogie, l'Eau, les Glaces, et l'Activit (OMEGA) data. Data were acquired, processed, atmospherically corrected, and weighted based on their relative areal contributions, resulting in nine representative regional spectra. The primary mineral phases identified in VNIR spectra are consistent with a dominantly basaltic composition and are in good agreement with previous TIR analyses. The variability in the shape and position of the broad 2 micron crystal field absorption feature, classically attributed to variations in pyroxene composition, is quantitatively assessed using modified Gaussian modeling (MGM) approaches. The position of this 2 micron band, though, can also be influenced by oxidative weathering processes like those identified in Antarctica, which result in more negative spectral slopes in the near-infrared as well as apparent shifts of the 2 micron band to shorter wavelengths [3]. We investigate the possibility that the observed variations of this feature on Mars may reflect a combination of primary pyroxene signatures conflated with variable amounts of oxidative weathering. All previously proposed martian high-silica phases exhibit similar TIR spectral signatures in addition to sharp vibrational absorptions in the VNIR at 1.4, 1.9, and 2.0-2.5 microns due to the presence of water and hydroxyl. Regional OMEGA spectra do not exhibit any of these vibrational absorption features, suggesting that these phases are not present at spectrally significant abundances. Interestingly, despite their similar TIR spectral signatures, products of oxidative weathering do not exhibit significant VNIR vibrational absorptions [4]. If oxidative weathering products are responsible for the previously observed "high-silica" spectral signatures, the martian surface has likely not experienced significantly warm and/or wet conditions capable of regional, subaerial, aqueous alteration since the formation of these low-albedo regions. [1] Rogers et al. (2007), [2] Rogers & Christensen (2007), [3] Salvatore (2013), [4] Salvatore et al. (2013).

  10. Mineral Fast Ion Conductors and Mineral Solid Electrolyte Batteries

    NASA Astrophysics Data System (ADS)

    Wang, Wenji

    2002-12-01

    This paper is intended to be a review of the recent situation and advances in the studies of mineral fast ion conductors and mineral solid electrolyte batteries. The reviews involve the following parts: The definition of both mineral fast ion conductor and mineral solid electrolyte battery; Comments on mineral fast ion conductors: Describe some very useful starting mineral materials for the preparation of mineral fast ion conductors, like montmorillonite, pyrophyllite, and kaolinite etc. Some important preparative methods for mineral fast ion conductors were introduced. The characterizations of mineral fast ion conductors: structure measurement, phase identification, ionic conductivity and electrochemical stability etc. also were described; Comments on mineral solid electrolyte batteries: The assembly for both of primary mineral solid electrolyte battery and secondary (rechargeable) mineral solid electrolyte battery was introduced. The concerned parameters of mineral solid electrolyte batteries were reported.

  11. 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)

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

    2007-12-01

    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.

  12. The effects of cinacalcet treatment on bone mineral metabolism, anemia parameters, left ventricular mass index and parathyroid gland volume in hemodialysis patients with severe secondary hyperparathyroidism.

    PubMed

    Torun, Dilek; Yildiz, Ismail; Micozkadioglu, Hasan; Nursal, Gul Nihal; Yigit, Fatma; Ozelsancak, Ruya

    2016-01-01

    The aim of this study was to investigate the effects of cinacalcet therapy on anemia parameters, bone mineral metabolism, left ventricular mass index (LVMI) and parathyroid gland volume in hemodialysis (HD) patients with secondary hyperparathyroidism. Twenty-five HD patients (M/F: 11/14, mean age: 45.217.9 years, mean HD duration: 96.432.7 months) were included in this prospective pilot study. The indication to start calcimimetic therapy was persistent serum levels of parathyroid hormone (PTH)>1000 pg/mL, refractory to intravenous (i.v.) vitamin D and phosphate-binding therapy. The initial and one-year results of adjusted serum calcium (Ca+2), phosphate (P), CaP product, PTH, hemoglobin (Hb) and ferritin levels, transferrin saturation index (TSAT), median weekly erythropoietin (EPO) dose, LVMI, and parathyroid volume by parathyroid ultrasonography were determined. There were no differences between pre- and post-treatment levels of serum Ca+2 (P=0.853), P (P=0.447), CaP product (P=0.587), PTH (P=0.273), ferritin (P=0.153) and TSAT (P=0.104). After 1 year of calcimimetic therapy, the Hb levels were significantly higher than the initial levels (P=0.048). The weekly dose of EPO decreased with no statistical significance. The dose of cinacalcet was increased from 32.412.0 to 60.024.4 mg/day (P=0.01). There were no differences between the pre- and post-treatment results regarding weekly vitamin D dose, parenteral iron dose, LVMI and parathyroid volume. The results of our study suggest that cinacalcet therapy might have an additional benefit in the control anemia in HD patients. PMID:26787561

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

    NASA Astrophysics Data System (ADS)

    Neymark, L. A.; Amelin, Y. V.

    2008-04-01

    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 (mm my -1) contain excess 206Pb and 208Pb formed from excesses of intermediate daughter isotopes and cannot be used as reliable 206Pb/ 238U geochronometers. The presence of excess intermediate daughter isotopes does not appreciably affect 207Pb/ 235U ages of U-enriched opal/chalcedony, which are interpreted as mineral formation ages. Opal and calcite from outer (younger) portions of coatings have 230Th/U ages from 94.6 3.7 to 361.3 9.8 ka and initial 234U/ 238U activity ratios (AR) from 4.351 0.070 to 7.02 0.12, which indicate 234U enrichment from percolating water. Present-day 234U/ 238U AR is 1 in opal/chalcedony from older portions of the coatings. The 207Pb/ 235U ages of opal/chalcedony samples range from 0.1329 0.0080 to 9.10 0.21 Ma, increase with microstratigraphic depth, and define slow long-term average growth rates of about 1.2-2.0 mm my -1, in good agreement with previous results. Measured 234U/ 238U AR in Mn-oxides, which pre-date the oldest calcite and opal/chalcedony, range from 0.939 0.006 to 2.091 0.006 and are >1 in most samples. The range of 87Sr/ 86Sr ratios (0.71156-0.71280) in Mn-oxides overlaps that in the late calcite. These data indicate that Mn-oxides exchange U and Sr with percolating water and cannot be used as a reliable dating tool. In the U-poor calcite samples, measured 206Pb/ 207Pb ratios have a wide range, do not correlate with Ba concentration as would be expected if excess Ra was present, and reach a value of about 1400, the highest ever reported for natural Pb. Calcite intergrown with opal contains excesses of both 206Pb and 207Pb derived from Rn diffusion and from direct ?-recoil from U-rich opal. Calcite from coatings devoid of opal/chalcedony contains 206Pb and 208Pb excesses, but no appreciable 207Pb excesses. Observed Pb isotope anomalies in calcite are explained by Rn-produced excess Pb. The Rn emanation may strongly affect 206Pb- 238U ages of slow-growing U-poor calcite, but should be negligible for dating fast-growing U-enriched speleothem calcite.

  14. Kinetics and microtextures formation during serpentinization: role of grain scale processes and transport

    NASA Astrophysics Data System (ADS)

    malvoisin, B.; Brunet, F.; Carlut, J. H.

    2013-12-01

    Serpentinization of mantle rocks plays a key role on the physical properties of the lithosphere at mid-ocean ridges and in subduction zones. This reaction is controlled by processes occurring at scales ranging from the grain to the lithosphere but the relative importance of these processes on the kinetics and microtextures formation has not been investigated. First, hydrothermal experiments on powders of San Carlos olivine at 500 bars in the 250 - 350 C range were monitored with a magnetic method to study the kinetics and processes of the reaction at the grain scale. For an initial grain size (IGS) > 5 ?m, lizardite, brucite, magnetite and hydrogen formed at a rate one to two orders of magnitude slower than the kinetics used to model serpentinization-related processes. Moreover, the serpentinization rate decreased linearly with the square of the IGS and reaction progress vs. time curves displayed a sigmoid form. The kinetics were controlled by the dissolution of olivine increasing with its reactive surface area which was generated with two cooperating processes (etch pits and grain fracturing) during the first stages of the reaction. Then, hydrothermal experiments were conducted on sintered San Carlos olivine to investigate the role of transport on the reaction. On sintered with a grain size of 1 to 5 ?m, low reaction progresses of ~ 3 % in 10 months were obtained and the rate of serpentinization was one order of magnitude slower than on powders and one order of magnitude faster than on a single grain of the size of the sintered. Kinetics were controlled by a coupling between the reaction rate at the grain scale and the rate of fluid pathways formation at grain boundaries. Lizardite precipitated where olivine dissolved whereas magnetite and brucite segregated at the surface of the sintered. These results are in agreement with the observation of magnetite formation and segregation in fractures in naturally serpentinized peridotites and could explain the sparse description of brucite in these rocks. Thermodynamical modelling shows that a removal of brucite in serpentinized peridotites could explain the loss of 10 % of the Mg measured in oceanic peridotites [1, 2]. [1] Snow, J.E. and H.J.B. Dick (1995) Pervasive magnesium loss by marine weathering of peridotites, Geochim. Cosmochim. Acta, 59, 4219-4235. [2] Niu, Y. (2004) Bulk-rock major and trace element compositions of abyssal peridotites: implications for mantle melting, melt extraction and post-melting processes beneath mid-ocean ridges, J. Petrol., 45, 2423-2458.

  15. Australian Mineral Foundation.

    ERIC Educational Resources Information Center

    Crowe, D. S.

    1980-01-01

    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)

  16. 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)

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

    2014-05-01

    Dissolved and solid phase cesium (Cs) was studied in the upper 1.2 km of a coastal granitoid fracture network on the Baltic Shield (sp 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 sp 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 sp 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 sp HRL: 4.1 ?g L-1; median Laxemar: 3.7 ?g L-1) and groundwater with marine origin (sp 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.

  17. Grain structure and microtexture evolution during superplastic forming of a high strength Al-Zn-Mg-Cu alloy

    SciTech Connect

    Liu, J.; Chakrabarti, D.J.

    1996-12-01

    Grain structure and microstructure evolution during superplastic forming were studied on an unrecrystallized sheet of a modified 7050 superplastic alloy. A SEM-based local orientation technique was used to cover a large number of (sub)grain boundaries in combination with other metallographic techniques. The gradual boundary misorientation and microtexture evolution during superplastic forming (SPF) confirmed that a continuous evolutionary process was occurring. There was no evidence of dynamic recrystallization at the stress maximum. The fraction of high angle boundaries increased rapidly once the mean misorientation reached a critical value. These and other results suggest that both grain boundary sliding (GBS) and dislocation slip were operative initially until the stress maximum was approached, beyond which GBS was predominant. The results of quantitative orientation distribution function (ODF) analyses suggest that grain rotation, which resulted in texture randomization, became important from slightly beyond the stress maximum through most of the stress-strain curve.

  18. 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)

    Strand, Kari; Immonen, Ninna

    2010-12-01

    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.

  19. 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)

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

    2013-11-01

    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)6.22ṡ2.05(H2O). Raman spectroscopy identifies an intense peak at 1003 cm-1 assigned to the PO43- ν1 symmetric stretching mode. Raman bands are observed at 1059 and 1118 cm-1 and are attributed to the PO43- ν3 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 ν4PO43- bending modes and Raman bands at 425, 444, 477 and 507 cm-1 are due to the ν2PO43- 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.

  20. Enumeration of thiobacilli within pH-neutral and acidic mine tailings and their role in the development of secondary mineral soil

    SciTech Connect

    Southam, G.; Beveridge, T.J. )

    1992-06-01

    The Lemoine tailings of Chibougamau, Quebec, Canada, were deposited as a pH-neutral mineral conglomerate consisting of aluminum-silicates, iron-aluminum-silicate, pyrite, chalcopyrite, and sphalerite. These tailings are colonized by an active population of Thiobacillus ferrooxidans which is localized to an acid zone occupying 40% of the tailings' surface. This population peaked at 7 [times] 10[sup 8] most probable number per gram of tailings during July and August 1990 and extended to a depth of 40 cm from the surface. Examination of samples over this depth profile by transmission electron microscopy and electron dispersive spectroscopy revealed a microbially mediated mineral transition from sulfides to chlorides and phosphates. Silicate minerals were unaltered by microbial action. Transmission electron microscopy showed a tight association between Thiobacillus species and the sulfide minerals, which helps account for their prominence in tailings environments. Accurate enumeration of T. ferrooxidans from tailings required the disruption of their bonding to the mineral interface. Vortexing of a 10% aqueous suspension of the tailings materials prior to most-probable-number analysis best facilitated this release. Even though heavy metals were highly mobile under acidic conditions at the Lemoine tailings, it was evident by transmission electron microscopy containing iron, copper, chlorine, phosphorus, and oxygen on bacterial surfaces and exopolymers. This biomineralization increased with increasing bacterial numbers and was most evident in the upper 3 cm of the acidic zone.

  1. 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)

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

    2014-05-01

    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.

  2. Mathematical model for bone mineralization

    PubMed Central

    Komarova, Svetlana V.; Safranek, Lee; Gopalakrishnan, Jay; Ou, Miao-jung Yvonne; McKee, Marc D.; Murshed, Monzur; Rauch, Frank; Zuhr, Erica

    2015-01-01

    Defective bone mineralization has serious clinical manifestations, including deformities and fractures, but the regulation of this extracellular process is not fully understood. We have developed a mathematical model consisting of ordinary differential equations that describe collagen maturation, production and degradation of inhibitors, and mineral nucleation and growth. We examined the roles of individual processes in generating normal and abnormal mineralization patterns characterized using two outcome measures: mineralization lag time and degree of mineralization. Model parameters describing the formation of hydroxyapatite mineral on the nucleating centers most potently affected the degree of mineralization, while the parameters describing inhibitor homeostasis most effectively changed the mineralization lag time. Of interest, a parameter describing the rate of matrix maturation emerged as being capable of counter-intuitively increasing both the mineralization lag time and the degree of mineralization. We validated the accuracy of model predictions using known diseases of bone mineralization such as osteogenesis imperfecta and X-linked hypophosphatemia. The model successfully describes the highly nonlinear mineralization dynamics, which includes an initial lag phase when osteoid is present but no mineralization is evident, then fast primary mineralization, followed by secondary mineralization characterized by a continuous slow increase in bone mineral content. The developed model can potentially predict the function for a mutated protein based on the histology of pathologic bone samples from mineralization disorders of unknown etiology. PMID:26347868

  3. 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

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

    2013-05-22

    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

  4. Characterization of the sulphate mineral coquimbite, a secondary iron sulphate from Javier Ortega mine, Lucanas Province, Peru - Using infrared, Raman spectroscopy and thermogravimetry

    NASA Astrophysics Data System (ADS)

    Frost, Ray L.; Gobac, Željka Žigovečki; López, Andrés; Xi, Yunfei; Scholz, Ricardo; Lana, Cristiano; Lima, Rosa Malena Fernandes

    2014-04-01

    The mineral coquimbite has been analysed using a range of techniques including SEM with EDX, thermal analytical techniques and Raman and infrared spectroscopy. The mineral originated from the Javier Ortega mine, Lucanas Province, Peru. The chemical formula was determined as ()∑2.00()3·9HO. Thermal analysis showed a total mass loss of ˜73.4% on heating to 1000 °C. A mass loss of 30.43% at 641.4 °C is attributed to the loss of SO3. Observed Raman and infrared bands were assigned to the stretching and bending vibrations of sulphate tetrahedra, aluminium oxide/hydroxide octahedra, water molecules and hydroxyl ions. The Raman spectrum shows well resolved bands at 2994, 3176, 3327, 3422 and 3580 cm-1 attributed to water stretching vibrations. Vibrational spectroscopy combined with thermal analysis provides insight into the structure of coquimbite.

  5. Estimation of martensite feature size in a low-carbon alloy steel by microtexture analysis of boundaries.

    PubMed

    Karthikeyan, T; Dash, Manmath Kumar; Saroja, S; Vijayalakshmi, M

    2015-01-01

    A methodology for classifying the hierarchy of martensite boundaries from the EBSD microtexture data of low-carbon steel is presented. Quaternion algebra has been used to calculate the ideal misorientation between product α variants for Kurdjumov-Sachs (KS) and its nearby orientation relationships, and arrive at the misorientation angle-axis set corresponding to packet (12 types), block (3 types) and sub-block boundaries. Analysis of proximity of experimental misorientation between data points from the theoretical misorientation set is found to be useful for identifying the different types of martensite boundaries. The optimal OR in the alloy system and the critical deviation threshold for identification of martensite boundaries could both be ascertained by invoking the 'Enhancement Factor' concept. The prior-γ grain boundaries, packet, block and sub-block boundaries could be identified reasonably well, and their average intercept lengths in a typical tempered martensite microstructure of 9Cr-1Mo-0.1C steel was estimated as 31 μm, 14 μm, 9 μm and 4 μm respectively. PMID:25464145

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

    PubMed Central

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

    2012-01-01

    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

  7. Secondary amenorrhea

    MedlinePLUS

    Amenorrhea - secondary; No periods - secondary; Absent periods - secondary; Absent menses - secondary; Absence of periods - secondary ... of amenorrhea. Many of the conditions that cause secondary amenorrhea will respond to treatment.

  8. Microtexture and macrotexture formation in the containerless solidification of undercooled Ni-18.7 at.% Sn eutectic melts

    SciTech Connect

    Li Mingjun . E-mail: li.mingjun@jaxa.jp; Nagashio, Kosuke; Ishikawa, Takehiko; Yoda, Shinichi; Kuribayashi, Kazuhiko

    2005-02-01

    The microscopic orientations of Ni-18.7 at.% Sn eutectics solidified from undercooled states, in particular, within an individual eutectic colony and among neighboring eutectic colonies, have been measured with respect to the eutectic Ni{sub 3}Sn and Ni phases; this was done using a scanning electron microscope equipped with the electron backscatter diffraction pattern (EBSP) mapping technique. The EBSPs and inverse pole figures indicate that the Ni{sub 3}Sn intermetallic compound is continuous and well oriented whereas the Ni solid solution is discontinuous and randomly oriented within an anomalous eutectic grain. Further examination reveals that although Ni particulates are random from an overall view, most neighboring Ni grains have small misorientations of less than 10 deg . The specific solidification sequence and the effect of released crystallization heat on subsequent crystallization are further considered, which enables the primary Ni phase to segment into individual grains whereas Ni{sub 3}Sn does not due to higher entropy of fusion. A little rotation or floating within the constrained framework of the crystallizing Ni{sub 3}Sn compound may yield small misorientation angles. The discontinuous Ni particulates and continuous Ni{sub 3}Sn network are of great significance in revealing the anomalous eutectic formation. The orientation among independent eutectic colonies is random owing to the random appearance of nuclei throughout the volume of undercooled melts. The macrotextures of pole figures (PFs) of two eutectic phases are also mapped versus melt undercooling, which can be interpreted well when considering the nucleation frequency, variation of eutectic colony size, microtexture within a single eutectic colony, and the overall microstructure evolution as a function of melt undercooling.

  9. 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

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

    2012-01-01

    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 (60N) 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<50nmol/l) was observed (896%) in the Somali group. The prevalence of SHPT (S-iPTH>65ng/l) was higher (791%) in Somali women than in Finnish women (16%). There was a significant association between S-25OHD and S-iPTH (r-049, P<0001). 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<0001) 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

  10. Relating rheological measurements to primary and secondary skin feeling when mineral-based and Fischer-Tropsch wax-based cosmetic emulsions and jellies are applied to the skin.

    PubMed

    Bekker, M; Webber, G V; Louw, N R

    2013-08-01

    Rheology measurements were correlated to skin sensations occurring when cream and petroleum jelly cosmetic products containing different amounts of synthetic Fischer-Tropsch wax were applied to the skin. A panel of 15 people with a background in cosmetic product development were asked to rate skin feelings when a range of petroleum jelly and cream samples are applied to the skin. Primary skin feel, or the spreadability of a cosmetic product, was correlated to the product's flow onset and maximum viscosity as measured by a Anton Paar rheometer, whereas secondary skin feel or the sensation occurring at the end of application when the product was completely rubbed into the skin was correlated to the product's viscosity measured at high shear rates. The cream samples prepared with a petroleum jelly containing 10% and 20% Fischer-Tropsch wax fell within the boundary of good primary skin feeling of cream products. Predominantly, synthetic petroleum jellies were given the best assessments in terms of primary skin feeling and were used with mineral-based petroleum jellies to determine the boundary of good primary skin feeling for petroleum jelly products. The further away a product falls from this rheological boundary the poorer the skin feeling assessment appears to be by the panel. Products containing Fischer-Tropsch waxes were given the best assessment by the panel for secondary skin feeling. Comments from the panel include that these products feel silky and light on the skin. The higher the Fischer-Tropsch wax content, the lower viscosity was at high shear rate (ϒ = 500 s(-1) ) and the higher the assessment by the panel. Rheological measurements can be used to objectively determine skin sensation when products are applied to the skin; this may shorten research and development times. A rheology boundary of certain product viscosity and shear stress applied is associated with good primary skin feeling for lotions, creams and petroleum jellies. Lower product viscosity at high shear rate seems to be associated with better secondary skin feeling. Products with higher Fischer-Tropsch wax content appear to be rated higher in terms of secondary skin feeling. PMID:23551222

  11. Mineral Chart

    MedlinePLUS

    ... How Can I Help a Friend Who Cuts? Mineral Chart KidsHealth > For Teens > Mineral Chart Print A A A Text Size en ... sources of calcium. You'll also find this mineral in broccoli and dark green, leafy vegetables. Soy ...

  12. Minerals yearbook

    SciTech Connect

    Not Available

    1988-01-01

    This volume contains the latest available mineral data on more than 150 foreign countries and discusses the importance of minerals in the economies of these nations. A separate chapter reviews the international minerals industry in general and its relationship to the world economy.

  13. 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

    Sonnenthal, Eric; Xu, Tianfu; Bodvarrson, Gudmundur

    2005-03-14

    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.

  14. 30 CFR 56.3400 - Secondary breakage.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Secondary breakage. 56.3400 Section 56.3400 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Ground Control Precautions 56.3400 Secondary breakage. Prior...

  15. 30 CFR 56.3400 - Secondary breakage.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Secondary breakage. 56.3400 Section 56.3400 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Ground Control Precautions 56.3400 Secondary breakage. Prior...

  16. 30 CFR 56.3400 - Secondary breakage.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Secondary breakage. 56.3400 Section 56.3400 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Ground Control Precautions 56.3400 Secondary breakage. Prior...

  17. Industrial Minerals.

    ERIC Educational Resources Information Center

    Brady, Lawrence L.

    1983-01-01

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

  18. Industrial Minerals.

    ERIC Educational Resources Information Center

    Brady, Lawrence L.

    1983-01-01

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

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

    SciTech Connect

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

    2014-08-21

    The U.S. Department of Energy’s Office of River Protection (ORP) is responsible for the retrieval, treatment, immobilization, and disposal of Hanford’s tank waste. Currently there are approximately 56 million gallons of highly radioactive mixed wastes awaiting treatment. A key aspect of the River Protection Project (RPP) cleanup mission is to construct and operate the Waste Treatment and Immobilization Plant (WTP). The WTP will separate the tank waste into high-level and low-activity waste (LAW) fractions, both of which will subsequently be vitrified. The projected throughput capacity of the WTP LAW Vitrification Facility is insufficient to complete the RPP mission in the time frame required by the Hanford Federal Facility Agreement and Consent Order, also known as the Tri-Party Agreement (TPA), i.e. December 31, 2047. Therefore, Supplemental Treatment is required both to meet the TPA treatment requirements as well as to more cost effectively complete the tank waste treatment mission. In addition, the WTP LAW vitrification facility off-gas condensate known as WTP Secondary Waste (WTP-SW) will be generated and enriched in volatile components such as {sup 137}Cs, {sup 129}I, {sup 99}Tc, Cl, F, and SO{sub 4} that volatilize at the vitrification temperature of 1150°C in the absence of a continuous cold cap (that could minimize volatilization). The current waste disposal path for the WTP-SW is to process it through the Effluent Treatment Facility (ETF). Fluidized Bed Steam Reforming (FBSR) is being considered for immobilization of the ETF concentrate that would be generated by processing the WTP-SW. The focus of this current report is the WTP-SW. FBSR offers a moderate temperature (700-750°C) continuous method by which WTP-SW wastes can be processed irrespective of whether they contain organics, nitrates, sulfates/sulfides, chlorides, fluorides, volatile radionuclides or other aqueous components. The FBSR technology can process these wastes into a crystalline ceramic (mineral) waste form. The mineral waste form that is produced by co-processing waste with kaolin clay in an FBSR process has been shown to be as durable as LAW glass. Monolithing of the granular FBSR product is being investigated to prevent dispersion during transport or burial/storage, but is not necessary for performance. A Benchscale Steam Reformer (BSR) was designed and constructed at the SRNL to treat actual radioactive wastes to confirm the findings of the non-radioactive FBSR pilot scale tests and to qualify the waste form for applications at Hanford. BSR testing with WTP SW waste surrogates and associated analytical analyses and tests of granular products (GP) and monoliths began in the Fall of 2009, and then was continued from the Fall of 2010 through the Spring of 2011. Radioactive testing commenced in 2010 with a demonstration of Hanford’s WTP-SW where Savannah River Site (SRS) High Level Waste (HLW) secondary waste from the Defense Waste Processing Facility (DWPF) was shimmed with a mixture of {sup 125/129}I and {sup 99}Tc to chemically resemble WTP-SW. Prior to these radioactive feed tests, non-radioactive simulants were also processed. Ninety six grams of radioactive granular product were made for testing and comparison to the non-radioactive pilot scale tests. The same mineral phases were found in the radioactive and non-radioactive testing. The granular products (both simulant and radioactive) were tested and a subset of the granular material (both simulant and radioactive) were stabilized in a geopolymer matrix. Extensive testing and characterization of the granular and monolith material were made including the following:  ASTM C1285 (Product Consistency Test) testing of granular and monolith;  ASTM C1308 accelerated leach testing of the radioactive monolith;  ASTM C192 compression testing of monoliths; and  EPA Method 1311 Toxicity Characteristic Leaching Procedure (TCLP) testing. The significant findings of the testing completed on simulant and radioactive WTP-SW are given below:  Data indicates {sup 99}Tc, Re, Cs, and I (all isotopes) report primarily to the mineral product and not significantly to the off-gas;  {sup 99}Tc and Re show similar behavior in partitioning between product (major) and off-gas (trace) so Re is an acceptable surrogate for {sup 99}Tc;  {sup 99}Tc, Re, SO{sub 4} and Cr behavior, with respect to their durability in the final granular product, are controlled by the oxygen fugacity in the FBSR/BSR process, i.e. control of the REDuction/ OXidation (REDOX) equilibrium;  Mineralogy features related to the XRD patterns associated with the identified crystalline species and their relative amounts in radioactive and simulant products from the BSR and Engineering Scale Technology Demonstration (ESTD) are the same;  TCLP data are acceptable when RCRA metals are not shimmed in excess of their predicted concentrations in actual WTP-SW feeds and REDOX is controlled or an iron oxide catalyst is present as an insoluble spinel host for Cr;  ASTM C1285 (Product Consistency Test) testing is below 2 g/m{sup 2} for the constituents of concern (COC); o Use of BET surface area to account for the surface roughness of the mineral granules demonstrates that the FBSR product is 2 orders of magnitude lower than the 2 g/m{sup 2} target;  All monoliths made from radioactive and non-radioactive (BSR and the ESTD engineering-scale) granular products pass compression testing at >500 psi, maintain PCT leach rates <2 g/m{sup 2}, and perform well in ASTM C1308 testing such that the measured Leach Indexes for key components (Na, Re/{sup 99}Tc and I) are all below current Hanford Integrated Disposal Facility (IDF) target limits.  Good mass balance closure on Tc, Re, Cs, and I in all BSR tests (radioactive and non-radioactive); o SRS DWPF Secondary Waste shimmed to match WTP-SW  86-102% recovery of Re in the product streams for simulant and radioactive campaigns  109% recovery of 99Tc in the product streams for radioactive campaign;  91% recovery of I in the product streams for the simulant campaign;  98% recovery of {sup 129}I, ~93% recovery of {sup 125}I, and 151% recovery of {sup 127}I in the product streams ({sup 125}I has highest analytic sensitivity) for radioactive campaign.

  20. Identifying Minerals from Their Infra-red Spectra.

    ERIC Educational Resources Information Center

    Paterson, W. G.

    1986-01-01

    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)

  1. Mineral Quantification.

    PubMed

    2016-01-01

    Optimal intakes of elements, such as sodium, potassium, magnesium, calcium, manganese, copper, zinc and iodine, can reduce individual risk factors including those related to cardiovascular diseases among humans and animals. In order to meet the need for vitamins, major minerals, trace minerals, fatty acids and amino acids, it is necessary to include a full spectrum programme that can deliver all of the nutrients in the right ratio. Minerals are required for normal growth, activities of muscles, skeletal development (such as calcium), cellular activity, oxygen transport (copper and iron), chemical reactions in the body, intestinal absorption (magnesium), fluid balance and nerve transmission (sodium and potassium), as well as the regulation of the acid base balance (phosphorus). The chapter discusses the chemical and instrumentation techniques used for estimation of minerals such as N, P, Ca, Mg, K, Na, Fe, Cu, Zn, B and Mb. PMID:26939263

  2. Clay Minerals

    SciTech Connect

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

    2014-03-14

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

  3. Industrial Minerals

    ERIC Educational Resources Information Center

    Bradbury, James C.

    1978-01-01

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

  4. Secondary parkinsonism

    MedlinePLUS

    Parkinsonism - secondary; Atypical Parkinson disease ... to be less responsive to medical therapy than Parkinson disease. ... Unlike Parkinson disease, some types of secondary parkinsonism may stabilize or even improve if the underlying cause is treated. ...

  5. Influence of cross-rolling on the micro-texture and biodegradation of pure iron as biodegradable material for medical implants.

    PubMed

    Obayi, Camillus Sunday; Tolouei, Ranna; Paternoster, Carlo; Turgeon, Stephane; Okorie, Boniface Adeleh; Obikwelu, Daniel Oray; Cassar, Glenn; Buhagiar, Joseph; Mantovani, Diego

    2015-04-01

    Iron-based biodegradable metals have been shown to present high potential in cardiac, vascular, orthopaedic and dental in adults, as well as paediatric, applications. These require suitable mechanical properties, adequate biocompatibility while guaranteeing a low toxicity of degradation products. For example, in cardiac applications, stents need to be made by homogeneous and isotropic materials in order to prevent sudden failures which would impair the deployment site. Besides, the presence of precipitates and pores, chemical inhomogeneity or other anisotropic microstructural defects may trigger stress concentration phenomena responsible for the early collapse of the device. Metal manufacturing processes play a fundamental role towards the final microstructure and mechanical properties of the materials. The present work assesses the effect of mode of rolling on the micro-texture evolution, mechanical properties and biodegradation behaviour of polycrystalline pure iron. Results indicated that cross-rolled samples recrystallized with lower rates than the straight-rolled ones due to a reduction in dislocation density content and an increase in intensity of {100} crystallographic plane which stores less energy of deformation responsible for primary recrystallization. The degradation resulted to be more uniform for cross-rolled samples, while the corrosion rates of cross-rolled and straight-rolled samples did not show relevant differences in simulated body solution. Finally, this work shows that an adequate compromise between biodegradation rate, strength and ductility could be achieved by modulating the deformation mode during cold rolling. PMID:25644452

  6. Mineral bioprocessing

    SciTech Connect

    Torma, A.E.

    1993-05-01

    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.

  7. [Secondary diabetes].

    PubMed

    Nomiyama, Takashi; Yanase, Toshihiko

    2015-12-01

    Secondary diabetes is diabetes that results as a consequence of another medication, endocrine disease or hereditary disease. Secondary diabetes is very broad and diverted category among diabetes. Clinically, pancreatic diabetes is one of the most popular secondary diabetes, which provides insulin deficiency following pancreatic diseases, such as pancreatitis and pancreatic cancer. Among endocrine diseases, Cushing's syndrome and acromegaly are typical endocrine disorders causing secondary diabetes. They mainly induce insulin resistance in early stage, however, insulin deficiency is also observed in advanced stage. Steroid is the most popular drug-induced secondary diabetes. Importantly, not only oral administered steroid but also cutaneous and inhalation steroid could induce hyperglycemia. Major hereditary diabetes are MODY and mitochondrial diabetes. Concerning secondary diabetes, careful medical examination is required. PMID:26666145

  8. Vitamins and Minerals

    MedlinePLUS

    ... I Help a Friend Who Cuts? Vitamins and Minerals KidsHealth > For Teens > Vitamins and Minerals Print A ... of a good thing? What Are Vitamins and Minerals? Vitamins and minerals make people's bodies work properly. ...

  9. 30 CFR 56.3400 - Secondary breakage.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Secondary breakage. 56.3400 Section 56.3400 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Ground Control...

  10. 30 CFR 56.3400 - Secondary breakage.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Secondary breakage. 56.3400 Section 56.3400 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Ground Control...

  11. Mineral revenues

    SciTech Connect

    Not Available

    1991-05-01

    GAO examined the effect that the Department of the Interiors March 1988 oil and gas product valuation regulations have had on royalties form Indian and federal onshore and offshore leases. During the development of the regulatory changes, the states and Indian tribes voiced concern that their share of royalties would drop because of the proposed revisions. The Minerals Management Service, however, believed that the regulations would be revenue neutral, with royalties staying about the same. Service reports show that from March 1988 to February 1990, overall royalties, after adjusting for volume and price difference, have neither consistently increased nor decreased. This paper concludes that the methodology used by the Service to analyze the effect of the revised revisions on royalties was reasonable and accounts for the two measurable factors-volume and price-that could be expected to affect royalties.

  12. High-pressure to ultrahigh-pressure metamorphism of kyanite eclogites from Pohorje, Slovenia: microtextural and thermobarometric evidence

    NASA Astrophysics Data System (ADS)

    Janak, M.; Vrabec, M.; Horvath, P.; Konecny, P.; Luptak, B.

    2003-04-01

    The evidence for high-pressure (HP) to ultrahigh-pressure (UHP) metamorphism in the Pohorje Mts. (Slovenia) has been found in the kyanite eclogites near Slovenska Bistrica. These eclogites are associated with the metaultrabasite body of 5 x 1 km size, with remnants of garnet peridotite. The country rocks of eclogites and metaultrabasites are amphibolites, paragneisses and micaschists. They belong to the pre-Neogene, metamorphic sequences within the Austroalpine units of the Eastern Alps, exposed in the proximity of the Periadriatic line. Kyanite eclogites consist of garnet, omphacite, kyanite and zoisite as a major primary phases. Garnet is unzoned, with 50 mol % of pyrope and 20 % of grossular content. Omphacite has up to 37 % of jadeite component. Phengite occurs as minor inclusions in garnet, with up to 3.4 Si p.f.u. Quartz inclusions in garnet, omphacite and kyanite are surrounded by radial fractures. Some of these inclusions contain a polycrystalline quartz which is diagnostic of pseudomorphs after coesite. Secondary phases occur in the coronas, symplectites and fractures. The most typical are diopside, amphibole and plagioclase after omphacite, and sapphirine, corundum, spinel and anorthite after kyanite. Sapphirine is peraluminous, close to the 3 : 5 : 1 end-member. Peak metamorphic conditions have been calculated from a combination of the garnet-clinopyroxene and garnet-phengite Fe-Mg exchange thermometers with the net-transfer reactions equilibria: (1) grossular + pyrope + 2 quartz/coesite = 3 diopside + 2 kyanite, and (2) 3 celadonite + 2 grossular + pyrope = 6 diopside + 3 muscovite. The ferric Fe was calculated from the stoichiometry. The intersections of garnet-clinopyroxene thermometer with equilibrium (1) define maximum pressure of 3.3 - 3.6 GPa at temperatures ranging from 760 - 870 C, well within the coesite stability field. The P-T values obtained from reactions involving phengite are lower (700 - 750 C; 2.0 - 2.3 GPa), consistent with the stability of quartz. This is interpreted due to retrograde re-equilibration of phengite inclusions. The results obtained from THERMOCALC (version 3.1) cluster close to the quartz/coesite boundary. The age of metamorphism in Pohorje eclogites is unknown. Based on Sm-Nd dating of garnet in the surrounding micaschists and the eclogites from the Koralpe and Saualpe, we suppose that HP and even UHP metamorphism in Pohorje eclogites was Alpine, related to continental subduction during the Cretaceous orogeny.

  13. Secondary Headaches

    MedlinePLUS

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

  14. [Secondary dressings].

    PubMed

    Philippe, Anne

    2016-01-01

    Wound management imposes a defined approach to each phase of healing and thereby the need for in-depth knowledge of the various medical devices available: primary and secondary dressings. Secondary dressings are essential as they have an impact on the efficacy of the primary dressing. Their role is to protect, reinforce and cover the primary dressing. In practice, it is usually nurses who have the responsibility of selecting and prescribing the most suitable dressing for the wound. PMID:26763570

  15. Minerals yearbook vol. I: metals and minerals

    USGS Publications Warehouse

    U.S. Geological Survey

    0000-01-01

    This volume, covering metals and minerals, contains chapters on approximately 90 commodities. In addition, this volume has chapters on mining and quarrying trends and on statistical surveying methods used by Minerals Information, plus a statistical summary.

  16. Mineral spirits poisoning

    MedlinePLUS

    Mineral spirits are liquid chemicals used to thin paint and as a degreaser. Mineral spirits poisoning occurs ... Mineral spirits ( Stoddard solvent ) Some paints Some floor and ... fluids White spirits Note: This list may not be all-inclusive.

  17. New Minerals and Science.

    ERIC Educational Resources Information Center

    Birch, William D.

    1997-01-01

    Defines geodiversity, compares it to biodiversity, and discusses the mineral classification system. Charts the discovery of new minerals in Australia over time and focuses on uses of these minerals in technological advances. (DDR)

  18. Rocks and Minerals.

    ERIC Educational Resources Information Center

    Naturescope, 1987

    1987-01-01

    Provides background information on rocks and minerals, including the unique characteristics of each. Teaching activities on rock-hunting and identification, mineral configurations, mystery minerals, and growing crystals are provided. Reproducible worksheets are included for two of the activities. (TW)

  19. [Secondary dyslipidemias].

    PubMed

    Vargov, V; Pytliak, M; Mechrov, V

    2012-03-01

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

  20. [Bone Cell Biology Assessed by Microscopic Approach. Bone mineralization by ultrastructural imaging].

    PubMed

    Hasegawa, Tomoka

    2015-10-01

    Bone mineralization can be divided into two phases ; one is primary mineralization associated with osteoblastic bone formation, and the other is secondary mineralization which gradually increases mineral density of bone matrix after the primary mineralization. Primary mineralization is initiated by matrix vesicles synthesized by mature osteoblasts. Crystalline calcium phosphates are nucleated inside these matrix vesicles, and then, get out of them forming spherical mineralized nodule, which can grow more by being supplied with Ca2+ and PO4(3-) (matrix vesicle mineralization). Thereafter, the mineralized nodules make contacts with surrounding collagen fibrils, extending mineralization along with their longitudinal axis from the contact points (collagen mineralization). In this review, the ultrastructural findings on bone mineralization, specially, primary mineralization will be provided. PMID:26412723

  1. Secondary Products

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In spite of their name, "secondary" products are essential for plant survival. They are required for basic cell functions as well as communicating the plant's presence to the surrounding environment and defense against pests as defined in the broad sense (i.e., diseases, nematodes, insects and plan...

  2. Science: Secondary.

    ERIC Educational Resources Information Center

    Curriculum Review, 1980

    1980-01-01

    This article reviews and compares five recent secondary science texts: Addison-Wesley Life Science (Gr. 7-9); Prentice-Hall Life Science (Gr. 7-9); Scott Foresman Biology (Gr. 9-12); Biology: Living Systems (Gr. 10-12); and Biology: The Science of Life (Gr. 10-12). (SJL)

  3. Ion beam microtexturing of surfaces

    NASA Technical Reports Server (NTRS)

    Robinson, R. S.

    1981-01-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2011-02-01

    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.

  5. Mathematical Model for the Mineralization of Bone

    NASA Technical Reports Server (NTRS)

    Martin, Bruce

    1994-01-01

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

  6. Mathematical Model for the Mineralization of Bone

    NASA Technical Reports Server (NTRS)

    Martin, Bruce

    1994-01-01

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

  7. Vitamins and Minerals

    MedlinePLUS

    ... Select a Language: Fact Sheet 801 Vitamins and Minerals WHY ARE VITAMINS AND MINERALS IMPORTANT? WHAT ARE ... A), selenium, Vitamin E (Tocopherol), and Vitamin C Magnesium , Selenium, Calcium and Zinc WHAT ABOUT OTHER SUPPLEMENTS? ...

  8. Bartering for Minerals.

    ERIC Educational Resources Information Center

    May, Kathie

    2002-01-01

    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)

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

    PubMed

    Adeyemi, Ademola O; Gadd, Geoffrey M

    2005-06-01

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

  10. Minerals leasing for landowners

    SciTech Connect

    Not Available

    1983-01-01

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

  11. Secondary Craters

    NASA Technical Reports Server (NTRS)

    2005-01-01

    7 October 2005 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows a cluster of craters in far western Arabia Terra. The crater cluster is oriented along a line that runs nearly east-west (left-right) across the scene. Clusters of craters positioned along a line like this are secondary craters -- that is, they formed as the result of a much larger meteor, asteroid, or cometary impact somewhere else in the region. These craters do not form from the object that impacted Mars to form the larger, primary crater; these are the product of the impact of the rocks and debris thrown out by the larger impact.

    Location near: 14.9oN, 19.3oW Image width: width: 3 km (1.9 mi) Illumination from: lower left Season: Northern Autumn

  12. Scientists observe fungi-dissolving minerals

    NASA Astrophysics Data System (ADS)

    Bhattacharya, Atreyee

    2012-10-01

    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.

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

    NASA Astrophysics Data System (ADS)

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

    2008-12-01

    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.

  14. American Strategic Minerals

    SciTech Connect

    Mangone, G.

    1984-01-01

    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.

  15. Rocks, minerals, and a dusty world

    SciTech Connect

    Klein, C.

    1993-12-31

    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.

  16. 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.

  17. Uranium mineralization in southern Victoria Land, Antarctica

    SciTech Connect

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

    1986-01-01

    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.

  18. Secondary systemic amyloidosis

    MedlinePLUS

    Amyloidosis - secondary systemic ... is unknown. You are more likely to develop secondary systemic amyloidosis if you have a long-term ... Symptoms of secondary systemic amyloidosis depend on which body ... by the protein deposits. These deposits damage normal tissues, ...

  19. 36 CFR 293.14 - Mineral leases and mineral permits.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 36 Parks, Forests, and Public Property 2 2012-07-01 2012-07-01 false Mineral leases and mineral... AGRICULTURE WILDERNESS-PRIMITIVE AREAS 293.14 Mineral leases and mineral permits. (a) All laws pertaining to mineral leasing shall extend to each National Forest Wilderness for the period specified in the...

  20. 36 CFR 293.14 - Mineral leases and mineral permits.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 36 Parks, Forests, and Public Property 2 2014-07-01 2014-07-01 false Mineral leases and mineral... AGRICULTURE WILDERNESS-PRIMITIVE AREAS 293.14 Mineral leases and mineral permits. (a) All laws pertaining to mineral leasing shall extend to each National Forest Wilderness for the period specified in the...

  1. 36 CFR 293.14 - Mineral leases and mineral permits.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 36 Parks, Forests, and Public Property 2 2013-07-01 2013-07-01 false Mineral leases and mineral... AGRICULTURE WILDERNESS-PRIMITIVE AREAS 293.14 Mineral leases and mineral permits. (a) All laws pertaining to mineral leasing shall extend to each National Forest Wilderness for the period specified in the...

  2. 36 CFR 293.14 - Mineral leases and mineral permits.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 36 Parks, Forests, and Public Property 2 2010-07-01 2010-07-01 false Mineral leases and mineral... AGRICULTURE WILDERNESS-PRIMITIVE AREAS 293.14 Mineral leases and mineral permits. (a) All laws pertaining to mineral leasing shall extend to each National Forest Wilderness for the period specified in the...

  3. 36 CFR 293.14 - Mineral leases and mineral permits.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 36 Parks, Forests, and Public Property 2 2011-07-01 2011-07-01 false Mineral leases and mineral... AGRICULTURE WILDERNESS-PRIMITIVE AREAS 293.14 Mineral leases and mineral permits. (a) All laws pertaining to mineral leasing shall extend to each National Forest Wilderness for the period specified in the...

  4. Vitamins, Minerals, and Mood

    ERIC Educational Resources Information Center

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

    2007-01-01

    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…

  5. The Miner's Canary

    ERIC Educational Resources Information Center

    Guinier, Lani

    2005-01-01

    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.

  6. Vitamins, Minerals, and Mood

    ERIC Educational Resources Information Center

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

    2007-01-01

    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

  7. Digging into Minnesota Minerals.

    ERIC Educational Resources Information Center

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

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

  8. Mineral Fiber Toxicology

    EPA Science Inventory

    The chemical and physical properties of different forms of mineral fibers impact biopersistence and pathology in the lung. Fiber chemistry, length, aspect ratio, surface area and dose are critical factors determining mineral fiber-associated health effects including cancer and as...

  9. Digging into Minnesota Minerals.

    ERIC Educational Resources Information Center

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

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

  10. Paricalcitol for secondary hyperparathyroidism in renal transplantation.

    PubMed

    Trillini, Matias; Cortinovis, Monica; Ruggenenti, Piero; Reyes Loaeza, Jorge; Courville, Karen; Ferrer-Siles, Claudia; Prandini, Silvia; Gaspari, Flavio; Cannata, Antonio; Villa, Alessandro; Perna, Annalisa; Gotti, Eliana; Caruso, Maria Rosa; Martinetti, Davide; Remuzzi, Giuseppe; Perico, Norberto

    2015-05-01

    Secondary hyperparathyroidism contributes to post-transplant CKD mineral and bone disorder. Paricalcitol, a selective vitamin D receptor activator, decreased serum parathyroid hormone levels and proteinuria in patients with secondary hyperparathyroidism. This single-center, prospective, randomized, crossover, open-label study compared the effect of 6-month treatment with paricalcitol (1 ?g/d for 3 months and then uptitrated to 2 g/d if tolerated) or nonparicalcitol therapy on serum parathyroid hormone levels (primary outcome), mineral metabolism, and proteinuria in 43 consenting recipients of renal transplants with secondary hyperparathyroidism. Participants were randomized 1:1 according to a computer-generated sequence. Compared with baseline, median (interquartile range) serum parathyroid hormone levels significantly declined on paricalcitol from 115.6 (94.8-152.0) to 63.3 (52.0-79.7) pg/ml (P<0.001) but not on nonparicalcitol therapy. At 6 months, levels significantly differed between treatments (P<0.001 by analysis of covariance). Serum bone-specific alkaline phosphatase and osteocalcin decreased on paricalcitol therapy only and significantly differed between treatments at 6 months (P<0.001 for all comparisons). At 6 months, urinary deoxypyridinoline-to-creatinine ratio and 24-hour proteinuria level decreased only on paricalcitol (P<0.05). L3 and L4 vertebral mineral bone density, assessed by dual-energy x-ray absorption, significantly improved with paricalcitol at 6 months (P<0.05 for both densities). Paricalcitol was well tolerated. Overall, 6-month paricalcitol supplementation reduced parathyroid hormone levels and proteinuria, attenuated bone remodeling and mineral loss, and reduced eGFR in renal transplant recipients with secondary hyperparathyroidism. Long-term studies are needed to monitor directly measured GFR, ensure that the bone remodeling and mineral effects are sustained, and determine if the reduction in proteinuria improves renal and cardiovascular outcomes. PMID:25194004

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

    PubMed Central

    Banfield, Jillian F.; Barker, William W.; Welch, Susan A.; Taunton, Anne

    1999-01-01

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

  12. Underground mineral extraction

    NASA Technical Reports Server (NTRS)

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

    1980-01-01

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

  13. MINER{nu}A Test Beam Commissioning

    SciTech Connect

    Higuera, A.; Castorena, J.; Urrutia, Z.; Felix, J.; Zavala, G.

    2009-12-17

    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.

  14. Carbon dioxide sequestration by mineral carbonation

    SciTech Connect

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

    2003-11-01

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

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

    SciTech Connect

    1993-12-31

    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.

  16. Minerals Yearbook, centennial edition 1981. Volume I. Metals and minerals

    SciTech Connect

    Not Available

    1983-01-01

    This edition of the Minerals Yearbook Marks the centennial of the first annual publication of comprehensive mineral industry statistics by the Federal Government. This volume of the Minerals Yearbook, covering metals and minerals, contains 71 commodity or commodity group chapters with data on approximately 90 minerals that were obtained as a result of the mineral information gathering activities of the Bureau of Mines. In addition, the volume contains a chapter on mining and quarrying trends and a statistical summary.

  17. Elastic properties of minerals

    SciTech Connect

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

    1993-09-01

    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.

  18. Biological Control on Mineral Transformation in Soils ?

    NASA Astrophysics Data System (ADS)

    Ziegler, K.; Hsieh, J. C.; Chadwick, O. A.; Kelly, E. F.

    2001-12-01

    Weathering of primary minerals is commonly linked to biological processes through the production of carbonic and organic acids. Plants can also play a role in weathering by removing soluble constituents and enhancing diffusion gradients within the soil. Here we investigate the synthesis of secondary minerals and the role of plants in removing elements that act as building blocks for these minerals. In order to minimize losses from leaching, we have sampled a chronosequence of soils forming on lava flows on Hawaii Island that receive about 200 mm of rain annually and have never been subjected to high levels of rainfall. The P concentration in the soils drops from almost 3000 mg/kg on a 1.5 ky lava flow to around 1000 mg/kg on a 350 ky lava flow. This loss of P can only be ascribed to P-uptake by plants with subsequent removal through the loss of above ground biomass through fire and/or wind removal. Over the same time frame the amount of plagioclase in the soils drops from around 22% of the <2 mm soil fraction on the youngest lava flow to virtually 0% on the 350 ky flow, suggesting a substantial release of Si. Elevated silicon in arid, basaltic soil environments often leads to formation of smectite, a feature not observed along the chronosequence. In fact, plagioclase is replaced by the kaolin mineral halloysite with allophane as an apparent precursor. Kaolin minerals are associated with moderate to intense leaching environments rather than the mild leaching conditions that influence these soils. We selected an intermediate age soil profile (170 ky lava flow) to conduct an in-depth investigation of the soil mineral composition. We detected a strong dominance of halloysite, the presence of gibbsite, but no smectite. Secondary halloysite formation is preferred over smectite formation when Si activities are relatively low, and the pH is acidic rather than alkaline. Although this mineral assemblage seems to imply formation under a wetter climatic regime, the oxygen isotopic composition of the halloysite suggests formation under soil environmental conditions similar to the present. The Si concentration in grass and tree leaves in the vicinity of the soil contain between 3 and 8% Si. Loss of these leaves to the nearby ocean (either as dried or burned residue) could be responsible for considerable Si removal in a manner similar to the P-removal. The resulting Si-deficient soil-water favors the formation of halloysite over smectite as is demonstrated by construction of mineral stability diagrams using the soil-water data from the soils along the chronosequence.

  19. Minerals Management Service: Strategic plan

    SciTech Connect

    1997-09-30

    This plan addresses the management of the mineral resources on the Outer Continental Shelf in an environmentally sound and safe manner and the timely collection, verification, and distribution of mineral revenues from Federal and Indian lands. The Minerals Management Service (MMS) manages the Nation`s natural gas, oil and other mineral resources on the Outer Continental Shelf (OCS), and collects, accounts for, and disburses revenues from offshore federal mineral leases and from onshore mineral leases on Federal and Indian lands.

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

    NASA Astrophysics Data System (ADS)

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

    2001-02-01

    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 β-uranophane are the most abundant U minerals, whereas Ca-montmorillonite and illite represent low temperature alteration products of the host granitic rocks. The genesis of secondary U minerals is mainly attributed to the action of oxic groundwater on previously corroded primary U minerals. These secondary U minerals were deposited near the surface from the circulating groundwater by evaporation.

  1. Minerals and mine drainage

    SciTech Connect

    Thomson, B.M.; Turney, W.R. |

    1995-06-01

    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.

  2. Minerals and mine drainage

    SciTech Connect

    Thomson, B.M.; Turney, W.R.

    1996-11-01

    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.

  3. Minerals Yearbook, 1988. Boron

    SciTech Connect

    Lyday, P.A.

    1988-01-01

    U.S. production and sales of boron minerals and chemicals decreased during the year. 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 report discusses the following: domestic data coverage; legislation and government programs; domestic production; comsumption and uses; prices; foreign trade; world capacity; world review--Argentina, Chile, France, Italy, Turkey, United Kingdom; Technology.

  4. Minerals Yearbook 1989: Lithium

    SciTech Connect

    Ober, J.A.

    1989-01-01

    The United States led the world in lithium mineral and compound production and consumption. Estimated consumption increased slightly, and world production also grew. Sales increased for domestic producers, who announced price increases for the third consecutive year. Because lithium is electrochemically reactive and has other unique properties, there are many commercial lithium products. Producers sold lithium as mineral concentrate, brine, compound, or metal, depending upon the end use. Most lithium compounds were consumed in the production of ceramics, glass, and primary aluminum.

  5. Fluorescent minerals, a review

    USGS Publications Warehouse

    Modreski, P.J.; Aumente-Modreski, R.

    1996-01-01

    Fluorescent minerals are more than just an attractive novelty, and collecting them is a speciality for thousands of individuals who appreciate their beauty, rarity, and scientific value. Fluorescent properties can be used as an aid to mineral identification, locality determination, and distinction between natural and synthetic gemstones. This article gives an overview of those aspects of fluorescence that are of most interest to collectors, hobbyists, and mineralogists. -from Authors

  6. Minerals: the resource gap

    SciTech Connect

    Velocci, T.

    1980-10-01

    US imports of important non-fuel minerals may have contributed to a false sense of security that could have serious economic and defense consequences. Imports account for over 90 percent of the chromite, manganese ore, and cobalt, and 90 percent of the platinum group metals. The primary sources for many of these minerals are the Soviet Union and Africa, a price and supply vulnerability which rivals Middle East oil and of which the American public is unaware. The Soviet shift to a net minerals importer will intensify competition for minerals and could lead to confrontation. The decline in US mineral production is blamed on escalating costs, largely from regulations, that prevent plant and equipment modernization and land withdrawal policies. A strategic stockpile planned for over 90 materials was established in 1939 for defense purposes, but eratic goals and planning as well as economic changes have kept the plan from being implemented. The first steps of an appropriate policy would promote domestic minerals production and open up Federal lands for exploration and development. (DCK)

  7. Evaluation of Water-Mineral Interaction Using Microfluidic Tests with Thin Sections

    NASA Astrophysics Data System (ADS)

    Oh, Y. S.; Ryu, J. H.; Koh, Y. K.; Jo, H. Y.

    2014-12-01

    For the geological disposal of radioactive wastes, geological settings and groundwater conditions are significantly important because of their effects on a radionuclide migration. One of the preferred host rocks for the radioactive waste disposal is crystalline rock. Fractures in crystalline rocks are main fluid pathways. Groundwater reacts with fracture filling minerals in fracture zones, resulting in physicochemical changes in the minerals and groundwater. In this study, fracture filling mineral-groundwater interactions were investigated by conducting microfluidic tests using thin sections at various conditions (i.e., fluid chemistry and flow rate). Groundwater and rock core samples collected from the KAERI Underground Research Tunnel (KURT) located in the Korea Atomic Energy Research Institute (KAERI) were used in this study. Dominant bedrock is two-mica granite, which contains both biotite and muscovite. Secondary minerals (e.g., chlorite, calcite and clay minerals) occur in fracture and alteration zones. In nature, water-mineral interactions generally take long time. Microfluidic tests were conducted to simulate water-mineral interactions in shorter time with smaller scale. Thin sections of fracture filling minerals, minerals from alteration zones, and natural and synthetic groundwater samples were used for the microfluidic tests. Results showed that water-mineral interactions at various conditions caused changes in groundwater chemistry, dissolution of minerals, precipitation of secondary minerals, and formation of colloids, which can affect radionuclide migration. In addition, the fluid chemistry and flow rate affected characteristics of water-rock interactions.

  8. 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)

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

    2007-01-01

    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.

  9. Minerals yearbook, 1982. volume 1. metals and minerals

    SciTech Connect

    Not Available

    1984-01-01

    This volume of the Minerals Yearbook, covering metals and minerals, contains 73 commodity or commodity group chapters with data on approximately 90 minerals that were obtained as a result of the mineral information gathering activities of the Bureau of Mines. In addition, the volume contains a chapter on mining and quarrying trends and a statistical summary.

  10. Minerals yearbook, 1983. Volume 1. Metals and minerals

    SciTech Connect

    Not Available

    1984-01-01

    This volume of the Minerals Yearbook, covering metals and minerals, contains 73 commodity or commodity group chapters with data on approximately 90 minerals that were obtained as a result of the mineral information gathering activities of the Bureau of Mines. In addition, the volume contains a chapter on mining and quarrying trends and a statistical summary.

  11. Minerals Yearbook, 1989. Volume i. Metals and Minerals

    SciTech Connect

    Not Available

    1989-01-01

    The edition of the Minerals Yearbook discusses the performance of the worldwide mineral industry during 1989 and provides background information to assist in interpreting that performance. Volume I, Metals and Minerals, contains chapters on virtually all metallic and industrial mineral commodities important to the U.S. economy. A chapter on advanced materials also has been added to the Minerals Yearbook series beginning with the 1989 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.

  12. Estimation of palaeohydrochemical conditions using carbonate minerals

    NASA Astrophysics Data System (ADS)

    Amamiya, H.; Mizuno, T.; Iwatsuki, T.; Yuguchi, T.; Murakami, H.; Saito-Kokubu, Y.

    2014-12-01

    The long-term evolution of geochemical environment in deep underground is indispensable research subject for geological disposal of high-level radioactive waste, because the evolution of geochemical environment would impact migration behavior of radionuclides in deep underground. Many researchers have made efforts previously to elucidate the geochemical environment within the groundwater residence time based on the analysis of the actual groundwater. However, it is impossible to estimate the geochemical environment for the longer time scale than the groundwater residence time in this method. In this case, analysis of the chemical properties of secondary minerals are one of useful method to estimate the paleohydrochemical conditions (temperature, salinity, pH and redox potential). In particular, carbonate minerals would be available to infer the long-term evolution of hydrochemical for the following reasons; -it easily reaches chemical equilibrium with groundwater and precipitates in open space of water flowing path -it reflects the chemical and isotopic composition of groundwater at the time of crystallization We reviewed the previous studies on carbonate minerals and geochemical conditions in deep underground and estimated the hydrochemical characteristics of past groundwater by using carbonate minerals. As a result, it was found that temperature and salinity of the groundwater during crystallization of carbonate minerals were evaluated quantitatively. On the other hand, pH and redox potential can only be understood qualitatively. However, it is suggested that the content of heavy metal elements such as manganese, iron and uranium, and rare earth elements in the carbonate minerals are useful indicators for estimating redox potential. This study was carried out under a contract with METI (Ministry of Economy, Trade and Industry) as part of its R&D supporting program for developing geological disposal technology.

  13. The mineral economy of Brazil--Economia mineral do Brasil

    USGS Publications Warehouse

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

    1999-01-01

    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.

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

    SciTech Connect

    1993-12-31

    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.

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

    SciTech Connect

    1994-12-31

    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.

  16. Measuring the Hardness of Minerals

    ERIC Educational Resources Information Center

    Bushby, Jessica

    2005-01-01

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

  17. Animal...Vegetable...or Mineral?

    ERIC Educational Resources Information Center

    Cameron, Eugene

    1973-01-01

    Outlines the problems facing the United States with mineral reserves being depleted, and the consumption of minerals outstripping production. Expresses concern about the deteriorating mineral position, and the ignorance and confusion of the public with respect to mineral production and supply, energy requirements, and environmental consequences.

  18. 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...

  19. American Strategic Minerals

    NASA Astrophysics Data System (ADS)

    DeYoung, John H., Jr.; Chidester, Alfred H.

    American Strategic Minerals is a collection of six papers that were presented in December 1982 at a conference organized by the Center for the Study of Marine Policy at the University of Delaware. According to editor Gerard J. Mangone, director of the center, the papers were commissioned “to investigate not only the objective resource situation, but also past United States policy on strategic minerals and future options open to Washington.” The authors and their chapter titles are John C. Kraft, University of Delaware: “Strategic minerals and world stability” V. Anthony Cammarota, Jr., U.S. Bureau of Mines: “America's dependence on strategic minerals” John D. Morgan, U.S. Bureau of Mines: “Future demands of the United States for strategic minerals” J. Robert Moore, University of Texas: “Alternative sources of strategic minerals from the seabed” Allan I. Mendelowitz and John E. Watson, U.S. General Accounting Office: “U.S. mining investments in developing countries” and James W. Curlin, Nautilus Press: “The political dimensions of strategic minerals.”

  20. Microbial control of mineral weathering kinetics

    SciTech Connect

    Bennett, P.C.; Hiebert, F.K.

    1995-12-01

    The influence of native microorganisms on mineral dissolution and precipitation kinetics was examined in a petroleum contaminated aquifer. In situ microcosms containing clean mineral fragments (calcite, dolomite, quartz, albite, microcline, anorthite, muscovite, biotite) were allowed to colonize and react over 1 year periods, and the surfaces then examined for microbial colonization patterns and weathering features. These experiments revealed distinct patterns of colonization, and weathering associated with microbial metabolism. Feldspar surfaces were widely colonized, and the colonized surfaces were deeply weathered, while secondary clays precipitated on uncolonized surfaces. Calcite surfaces were sparsely colonized, but deeply pitted around microbial colonies. Distinctive precipitation features were otherwise observed on all other surfaces, with overgrowth morphology related to crystal orientation. The rates of calcite dissolution was directly controlled at the microscopic level by microbial activity around colonies, while precipitation rate is probably related to microbial perturbation of the meso-scale inorganic geochemistry, and may be limited by dolomite dissolution rate.

  1. Green Clay Minerals

    NASA Astrophysics Data System (ADS)

    Velde, B.

    2003-12-01

    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 the genesis of green clay minerals; they contain iron in both oxidation states.Unfortunately modern methods of mineral analysis on a microscopic scale, electron microbeam and others, do not allow the determination of the different oxidation states of iron especially for nonstoichiometric minerals. One can use Mssbauer spectral analysis, but the scales of observations are not the same (Mssbauer needing more material); one method used for observations on a microscale, the other on a macroscale. Given the problems of micro- and macroscale observations, oxidation state information is almost excluded from data gathered since the 1980s or so, and hence information concerning the relations of iron reduction and clay genesis must be taken from older studies. A second, much greater problem is that little X-ray diffraction (XRD) work is done on samples which are analyzed chemically by electron microbeam studies. In the past both types of information, structural and chemical, were available for the same sample. Hence not only do we have no precise chemical data for many samples (oxidation state of iron), but there is a rarity of mineral structural information to go along with the incomplete chemistry. This is critical for the study of clay minerals, because slight chemical changes in a clay mineral are frequently accompanied by changes in its structure, especially when one deals with interstratified clay minerals (mica/smectites for example). In fact, the tendency to obtain more and more precision (analysis of a smaller and smaller sized sample) has led to a total loss of mineralogical data. The Heisenberg principle is unwittingly verified by geologists. We know more about a small part of a sample, but we know less about its whole. As a result, the following discussion is based largely upon old data, those which combine iron oxidation states and XRD information.

  2. Maneuverable full face miner

    SciTech Connect

    Delli-gatti, F. A.; Justice, J. C.

    1980-12-16

    A full face miner including a simplified conveying arrangement and designed for easy maneuverability into and out of mine sites. A plow operatively mounted to and longitudinally movable with each of a pair of rotatable cutting heads of the miner provide for the conveyance of cut coal to a middle conveying portion for ultimate transport away from the mine site. The mounting mechanism for the cutting heads is designed so that at least the end portions thereof are movable from a position generally parallel to the mine face to a position generally perpendicular to the mine face and extending in front of and in line with the central conveying means, for ease of withdrawal from the mining area. A motive power source, such as a powered crawler or powered wheels, is provided which is movable into operative engagement with the ground to transport the miner to and from the mining site when in a collapsed position.

  3. Applied Mineral Inventory Estimation

    NASA Astrophysics Data System (ADS)

    Sinclair, Alastair J.; Blackwell, Garston H.

    2002-05-01

    Applied Mineral Inventory Estimation presents a comprehensive applied approach to the estimation of mineral resources/reserves with particular emphasis on the geological basis of such estimations, the need for and maintenance of a high quality assay data base, the practical use of comprehensive exploratory data evaluation, and the importance of a comprehensive geostatistical approach to the estimation methodology. Practical problems and real data are used throughout as illustrations. Each chapter ends with a summary of practical concerns, a number of exercises and a short list of references for supplementary study. This textbook is suitable for any university or mining school that offers senior undergraduate and graduate student courses on mineral resource/reserve estimation.

  4. 43 CFR 19.8 - Prospecting, mineral locations, mineral patents, and mineral leasing within National Forest...

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    .... 2 of 43 CFR, which appears in Volume II of the List of CFR Sections Affected, 1964-1972, for the... patents, and mineral leasing within National Forest Wilderness. 19.8 Section 19.8 Public Lands: Interior... 19.8 Prospecting, mineral locations, mineral patents, and mineral leasing within National...

  5. 43 CFR 19.8 - Prospecting, mineral locations, mineral patents, and mineral leasing within National Forest...

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    .... 2 of 43 CFR, which appears in Volume II of the List of CFR Sections Affected, 1964-1972, for the... patents, and mineral leasing within National Forest Wilderness. 19.8 Section 19.8 Public Lands: Interior... 19.8 Prospecting, mineral locations, mineral patents, and mineral leasing within National...

  6. 43 CFR 19.8 - Prospecting, mineral locations, mineral patents, and mineral leasing within National Forest...

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    .... 2 of 43 CFR, which appears in Volume II of the List of CFR Sections Affected, 1964-1972, for the... patents, and mineral leasing within National Forest Wilderness. 19.8 Section 19.8 Public Lands: Interior... 19.8 Prospecting, mineral locations, mineral patents, and mineral leasing within National...

  7. 43 CFR 19.8 - Prospecting, mineral locations, mineral patents, and mineral leasing within National Forest...

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    .... 2 of 43 CFR, which appears in Volume II of the List of CFR Sections Affected, 1964-1972, for the... patents, and mineral leasing within National Forest Wilderness. 19.8 Section 19.8 Public Lands: Interior... 19.8 Prospecting, mineral locations, mineral patents, and mineral leasing within National...

  8. Microbially mediated mineral carbonation

    NASA Astrophysics Data System (ADS)

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

    2010-12-01

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

  9. Minerals Yearbook 1989: Boron

    SciTech Connect

    Lyday, P.A.

    1990-08-01

    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.

  10. Clay Mineral: Radiological Characterization

    NASA Astrophysics Data System (ADS)

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

    2008-08-01

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

  11. Oxidants from Pulverized Minerals

    NASA Astrophysics Data System (ADS)

    Martel, L. M. V.

    2007-06-01

    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.

  12. Mixtures and mineral reactions

    SciTech Connect

    Saxena, S.; Ganguly, J.

    1987-01-01

    Considerable progress has been made in our understanding of the physicochemical evolution of natural rocks through systematic analysis of the compositional properties and phase relations of their mineral assemblages. This book brings together concepts of classical thermodynamics, solution models, and atomic ordering and interactions that constitute a basis of such analysis, with examples of application to subsolidus petrological problems.

  13. Oxalate minerals on Mars?

    NASA Astrophysics Data System (ADS)

    Applin, D. M.; Izawa, M. R. M.; Cloutis, E. A.; Goltz, D.; Johnson, J. R.

    2015-06-01

    Small amounts of unidentified organic compounds have only recently been inferred on Mars despite strong reasons to expect significant concentrations and decades of searching. Based on X-ray diffraction and reflectance spectroscopic analyses we show that solid oxalic acid and its most common mineral salts are stable under the pressure and ultraviolet irradiation environment of the surface of Mars, and could represent a heretofore largely overlooked reservoir of organic carbon in the martian near-surface. In addition to the delivery to Mars by carbonaceous chondrites, oxalate minerals are among the predicted breakdown products of meteoritic organic matter delivered to the martian surface, as well as any endogenic organic carbon reaching the martian surface from the interior. A reinterpretation of pyrolysis experiments from the Viking, Phoenix, and Mars Science Laboratory missions shows that all are consistent with the presence of significant concentrations of oxalate minerals. Oxalate minerals could be important in numerous martian geochemical processes, including acting as a possible nitrogen sink (as ammonium oxalate), and contributing to the formation of organic carbonates, methane, and hydroxyl radicals.

  14. TRACE MINERAL DEFICIENCIES

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The impact of trace element deficiencies of human health and well-being is presented in an abridged form. The general biological roles, mechanisms involved in homeostasis, factors affecting the manifestation of deficiency signs, and treatments for deficiencies of trace mineral elements are described...

  15. Identification of Minerals

    ERIC Educational Resources Information Center

    Allison, Diane

    2005-01-01

    The lab described in this article was developed to satisfy two major goals. First, the activity is designed to show students the proper techniques used to identify the seven characteristics of all minerals. Second, the lab gives students a glimpse into the life of a professional field geologist. The author has students complete this lab at the end…

  16. Bioleaching of Minerals

    SciTech Connect

    F. Roberto

    2002-02-01

    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.

  17. Identification of Minerals

    ERIC Educational Resources Information Center

    Allison, Diane

    2005-01-01

    The lab described in this article was developed to satisfy two major goals. First, the activity is designed to show students the proper techniques used to identify the seven characteristics of all minerals. Second, the lab gives students a glimpse into the life of a professional field geologist. The author has students complete this lab at the end

  18. Mercury from mineral deposits and potential environmental impact

    USGS Publications Warehouse

    Rytuba, J.J.

    2003-01-01

    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.

  19. Isotopic bone mineralization rates in maintenance dialysis patients

    SciTech Connect

    Cochran, M.; Stephens, E.

    1983-09-01

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

  20. Minerals yearbook 1977. Volume I. Metals and minerals

    SciTech Connect

    Not Available

    1980-01-01

    This report contains chapters on virtually all metallic and nonmetallic mineral commodities important to the domestic economy. In addition, it includes a general review chapter on the mineral industries, a chapter on mining and quarrying trends, and a statistical summary.

  1. Minerals Yearbook, 1988. Volume 1. Metals and minerals

    SciTech Connect

    Not Available

    1990-01-01

    Volume I of the 1988 Minerals Yearbook, covering metals and minerals, contains 79 commodity or commodity group chapters with data on approximately 90 minerals that were obtained as a result of the mineral information gathering activities of the U.S. Bureau of Mines. In addition, the volume contains chapters on mining and quarrying trends and on the statistical surveying methods used by the Bureau of Mines and a statistical summary.

  2. Minerals yearbook, 1984. Volume 1. Metals and minerals

    SciTech Connect

    Not Available

    1985-01-01

    The volume of the Minerals Yearbook, covering metals and minerals, contains 72 commodity or commodity group chapters with data on approximately 90 minerals that were obtained as a result of the mineral information gathering activities of the Bureau of Mines. In addition, the volume contains a chapter on mining and quarrying trends, a chapter discussing the statistical surveying methods used by the Bureau of Mines, and a statistical summary.

  3. Minerals yearbook, 1985. Volume 1. Metals and minerals

    SciTech Connect

    Not Available

    1987-01-01

    This volume of the 1985 Minerals Yearbook, covering metals and minerals, contains 72 commodity or commodity group chapters with data on approximately 90 minerals that were obtained as a result of the mineral information gathering activities of the Bureau of Mines. In addition, the volume contains a chapter on mining and quarrying trends, a chapter discussing the statistical surveying methods used by the Bureau of Mines, and a statistical summary.

  4. Iron-titanium oxide minerals and associated alteration phases in some uranium-bearing sandstones

    USGS Publications Warehouse

    Reynolds, Richard L.; Goldhaber, Martin B.

    1978-01-01

    Detrital iron-titanium (Fe-Ti) oxide minerals of the ulvospinel-magnetite (titanomagnetite) and ilmenite-hematite (titanohematite) solid solution series are common in uranium-bearing sandstones. Alteration of Fe-Ti oxide minerals in oxidizing environments formed secondary products (primarily hematite) that are distinct from those produced under reducing conditions (iron disulfide minerals). Oxidation of sulfidized Fe-Ti oxide minerals, by the processes that formed uranium rolls, produced ferric oxide minerals (limonite) having textures that mimic those of the iron disulfides. Titanomagnetite and titanohematite have been severely depleted in the ore-bearing zones of some uranium deposits. The alteration of detrital Fe-Ti oxide minerals near uranium ore deposits may produce characteristic signatures in the magnetization of the sandstone. Knowledge of the distribution and magnetic properties of these minerals can aid in interpreting data from total magnetic-field and magnetic-susceptibility surveys of uranium deposits. 

  5. Mineral oil soluble borate compositions

    SciTech Connect

    Dulat, J.

    1981-09-15

    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.

  6. Minerals and mine drainage

    SciTech Connect

    Liang, H.C.; Thomson, B.M.

    2009-09-15

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

  7. [Cervical osteochondrosis in miners].

    PubMed

    Kolesov, V G

    1992-01-01

    Characteristics, frequency and distribution of vertebrogenic diseases involving cervico-brachial region were studied in more than 1,000 miners from asian North and East exposed to vibration. The data were compared with the results of examination of drivers. The investigation revealed a high level of vertebrogenic cervical pain and cervico-brachial pain in miners with a long length of service, especially in those suffering from vibration disease and frequent osteochondrosis manifestation in younger age, especially in subjects working beyond the Polar Circle. Occupational hazards are proved to play a leading role in the early development of vertebrogenic diseases, and vibration disease predisposes to such pathology. The results make possible to consider the vertebrogenic cervical pain and cervico-brachial pain as occupational diseases in young-aged workers with long length of service or evaluate such diseases as complications of vibration disease in individuals facing this occupational pathology. PMID:1478518

  8. Magnetic birefringence of minerals.

    PubMed

    Jennings, Barry R; Wilson, Stephen R; Ridler, Peter J

    2005-01-15

    The earliest reports of magnetically induced optical birefringence included data for liquids, magnetic fluids and colloidal suspensions. Recent work has shown that with relatively straightforward apparatus, when carefully designed and aligned, measurable effects can be recorded even for suspensions of relatively weak diamagnetic materials, including mineral particles. By recording the magnitude of the birefringence induced in magnetic fields of up to two Tesla, a method for the analysis of the magnetic and optical characteristics of these diamagnetic colloids is evidenced. The principles, apparatus and methodology involved are described and novel data reported for the minerals attapulgite, bentonite, hectorite, kaolinite, montmorillonite and vermiculite. Preliminary experiments using pulsed fields on vermiculite sols show that, in favourable circumstances, estimates of particle size can be made by analysing signal response rates. PMID:15571692

  9. Clay Mineral: Radiological Characterization

    SciTech Connect

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

    2008-08-07

    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.

  10. DIAMOND SECONDARY EMITTER

    SciTech Connect

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

    2005-10-09

    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.

  11. Digital mineral logging system

    SciTech Connect

    West, J.B.

    1980-10-14

    A digital mineral logging system acquires data from a mineral logging tool passing through a borehole and transmits the data uphole to an electronic digital signal processor. A predetermined combination of sensors, including a deviometer, is located in a logging tool for the acquisition of the desired data as the logging tool is raised from the borehole. Sensor data in analog format is converted in the logging tool to a digital format and periodically batch transmitted to the surface at a predetermined sampling rate. An identification code is provided for each mineral logging tool, and the code is transmitted to the surface along with the sensor data. The self-identifying tool code is transmitted to the digital signal processor to identify the code against a stored list of the range of numbers assigned to that type of tool. The data is transmitted up the d-c power lines of the tool by a frequency shift key transmission technique. At the surface, a frequency shift key demodulation unit transmits the decoupled data to an asynchronous receiver interfaced to the electronic digital signal processor. During a recording phase, the signals from the logging tool are read by the electronic digital signal processor and stored for later processing. During a calculating phase, the stored data is processed by the digital signal processor and the results are outputted to a printer or plotter, or both.

  12. Digital mineral logging system

    SciTech Connect

    West, J.B.

    1980-10-14

    A digital mineral logging system acquires data from a mineral logging tool passing through a borehole and transmits the data uphole to an electronic digital signal processor. A predetermined combination of sensors, including a deviometer, is located in a logging tool for the acquistion of the desired data as the logging tool is raised from the borehole. Sensor data in analog format is converted in the logging tool to a digital format and periodically batch transmitted to the surface at a predetermined sampling rate. An identification code is provided for each mineral logging tool, and the code is transmitted to the surface along with the sensor data. The self-identifying tool code is transmitted to the digital signal processor to identify the code against a stored list of the range of numbers assigned to that type of tool. The data is transmitted up the d-c power lines of the tool by a frequency shift key transmission technique. At the surface, a frequency shift key demodulation unit transmits the decoupled data to an asynchronous receiver interfaced to the electronic digital signal processor. During a recording phase, the signals from the logging tool are read by the electronic digital signal processor and stored for later processing. During a calculating phase, the stored data is processed by the digital signal processor and the results are outputted to a printer or plotter, or both.

  13. Clay Mineral Preferred Orientation

    NASA Astrophysics Data System (ADS)

    Day-Stirrat, R. J.

    2014-12-01

    Anisotropy of the orientation of clay minerals, often referred to as texture, may be unique to sediments' deposition, composition, deformation or diagenetic history. The literature is rich with studies that include preferred orientation generation in fault gouge, low-grade metamorphic rocks, sediments with variable clay content and during the smectite-to-illite transformation. Untangling the interplay between many competing factors in any one geologic situation has proven a significant challenge over many years. Understanding how, where and when clay minerals develop a preferred orientation has significant implications for permeability anisotropy in shallow burial, the way mechanical properties are projected from shallower to deeper settings in basin modeling packages and the way velocity anisotropy is accounted for in seismic data processing. The assessment of the anisotropic properties of fine-grained siliciclastic rocks is gaining significant momentum in rock physics research. Therefore, a fundamental understanding of how clay minerals develop a preferred orientation in space and time is crucial to the understanding of anisotropy of physical properties. The current study brings together a wealth of data that may be used in a predictive sense to account for fabric anisotropy that may impact any number of rock properties.

  14. Point Defects in Minerals

    NASA Astrophysics Data System (ADS)

    Schock, Robert N.

    1985-05-01

    Point defects exist in all crystals at temperatures above absolute zero. They arise either to prevent charge imbalances d u e to the presence of impurities or because thermal energy has caused atoms to be displaced from their normal positions in th e structure. T h e atoms are free to migrate within the crystal, and this migration provides an energy-efficient mechanism for the movement and mixing of atoms. This movement results in mass transport, or diffusion, and in the attainment of thermal equilibrium. If the defect can be defined in terms of a site in a crystal lattice, it is called a point defect. More complex defects, such as dislocations, grain boundaries, or inclusions, can be considered as extensions of point defects in one or more dimensions. Point defects can be treated as chemical entities, and their behavior can be quantitatively predicted by various theories. Their role in minerals can thus be predicted, although the minerals of most interest, the silicates, are chemically and structurally complex enough to render the work tedious. Nevertheless, many techniques developed in other fields are now being applied to understanding the behavior of point defects in minerals that are important to the evolution of the earth and the terrestrial planets.

  15. Major issues in miner health.

    PubMed Central

    Joyce, S

    1998-01-01

    As recently as the last few decades, thousands of miners died in explosions, roof collapses, fires, and floods each year, and lung disease caused by inhaling mineral dusts was ubiquitous. Miners worked virtually unprotected, and were often treated as expendable bodies fulfilling critical roles in this important industry, which in the United States comprises about 5% of the gross domestic product. PMID:9799195

  16. The Indian Mineral Development Act.

    ERIC Educational Resources Information Center

    Houle, Antoinette

    1986-01-01

    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)

  17. 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, which causes them to release ...

  18. Minerals yearbook, 1991. Volume 1. Metals and minerals. Annual report

    SciTech Connect

    1991-12-31

    This edition of the Mineral Yearbook discusses the performance of the worlwide minerals and materials industry during 1991 and provides background information to assist in interpreting that performance. Volume 1, Metals and Mineral, contains chapters on virtually all metallic and industrial mineral commodities important to the U.S. economy. Chapters on advanced materials and nonrenewable organic materials also were added to the Minerals Yearbook series beginning with the 1989 and 1990 volumes, respectively. A new chapter on nonferrous metals recycling has been initiated in this 1991 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.

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

    SciTech Connect

    Not Available

    1992-01-01

    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.

  20. Platinum mineralization in the Kapalagulu Intrusion, western Tanzania

    NASA Astrophysics Data System (ADS)

    Wilhelmij, Harry R.; Cabri, Louis J.

    2015-09-01

    Low-grade copper and nickel mineralization was found near the eastern shore of Lake Tanganyika at Kungwe Bay in the early part of the twentieth century. The mineralization occurs in harzburgite at the base of a layered gabbro complex known as the Kapalagulu Intrusion, emplaced between the Paleoproterozoic Ubendian basement and overlying Neoproterozoic Itiaso Group metasediments. Several mining and exploration companies continued the geophysical and drilling exploration for base metals throughout the last century culminating in the discovery of high-grade platinum-group element (PGE) mineralization associated with chromitite and sulfide-bearing harzburgite within the southeastern extension of the Kapalagulu Intrusion (known as the Lubalisi Zone) that is covered by a layer of nickel-rich laterite regolith. The poorly layered southeastern harzburgite forms part of the >1500 m-thick Lower Ultramafic Sequence and resembles a dike-like body that flares upwards into a succession of well-layered gabbroic rocks of the Upper Mafic Sequence. No PGE mineralization has been found in the layered gabbro; all the mineralization is associated with the chromite- and sulfide-rich harzburgite of the Lower Ultramafic Sequence and the laterite regolith overlying the mineralized harzburgite. The Lubalisi Zone harzburgite is underlain by basal dunite and overlain by an interval of layered harzburgite and troctolite and this ultramafic sequence is folded into a syncline that plunges towards the northwest that has been modified by major dolerite-filled faults orientated subparallel to the fold axial surface. Extensive deep drilling in the Lubalisi Zone of the Kapalagulu Intrusion shows that the folded harzburgite can be subdivided into a lower feldspathic harzburgite, a harzburgite containing chromitite seams and intervals of sulfide and chromite mineralization known as the Main Chromite Sulfide Succession (MCSS), an overlying sulfide-rich harzburgite, and an upper feldspathic harzburgite. Impersistent, stratiform PGE mineralized horizons occur within the MCSS harzburgite from which drill core samples were taken for platinum-group mineral (PGM) characterization from two drill holes. Where the PGE reefs reach the surface there is residual PGE mineralization within the laterite regolith from which drill core samples were taken from various laterite lithological units for PGM characterization. As the harzburgite PGE reefs contain significant concentrations of both sulfide and chromite (including chromitite seams) they resemble the PGE-rich chromitite seams of the Bushveld Complex rather than the PGE-bearing Main Sulfide Zone of the Great Dyke and Main Sulfide Layer of the Munni Munni Complex. The dominant Pd PGM in three PGE reef samples varies, ranging (n = 164, relative wt%) from bismuthides (63 %), bismuthtellurides (19 %), and tellurides (6 %), to tellurides (39 %), bismuthtellurides (24 %), stannides (14 %), and alloys (13 %), and to antimon-arsenides (33 %), stannides (21 %), bismuthides (17 %), tellurides (13 %), and alloys (10 %). From 13.5 % to 21.0 % of the total Pd occurs as a solid solution in pentlandite. The three samples have similar Pt PGM modal distributions (n = 172, relative wt%); the dominant Pt mineral is sperrylite (79, 58, and 47 %) followed by tellurides (15, 17, 21 %), alloys (2, 1, 1 %), and sulfides (2, 1, 0 %). Comparison of Pd/Pt ratios from assays to those calculated from minerals show that the data for the Pt and Pd PGM are very robust, confirming the concentration methodology and characterization. Study of samples from a shallow drill hole penetrating the laterite regolith shows that the primary Pd mineralization has not survived oxidation, is mainly dispersed, but some was reconstituted to form secondary minerals: cabriite, unnamed tellurides, a selenide, a Pd-Te-Hg mineral, alloys and Pd-bearing secondary sulfides (millerite and heazlewoodite). The primary Pt minerals are more resistant to oxidation and dissolution, especially sperrylite and isoferroplatinum, but it is likely that other Pt alloys (tetraferroplatinum and tulameenite) are of secondary origin after dissolution of Pt tellurides.

  1. Platinum mineralization in the Kapalagulu Intrusion, western Tanzania

    NASA Astrophysics Data System (ADS)

    Wilhelmij, Harry R.; Cabri, Louis J.

    2016-03-01

    Low-grade copper and nickel mineralization was found near the eastern shore of Lake Tanganyika at Kungwe Bay in the early part of the twentieth century. The mineralization occurs in harzburgite at the base of a layered gabbro complex known as the Kapalagulu Intrusion, emplaced between the Paleoproterozoic Ubendian basement and overlying Neoproterozoic Itiaso Group metasediments. Several mining and exploration companies continued the geophysical and drilling exploration for base metals throughout the last century culminating in the discovery of high-grade platinum-group element (PGE) mineralization associated with chromitite and sulfide-bearing harzburgite within the southeastern extension of the Kapalagulu Intrusion (known as the Lubalisi Zone) that is covered by a layer of nickel-rich laterite regolith. The poorly layered southeastern harzburgite forms part of the >1500 m-thick Lower Ultramafic Sequence and resembles a dike-like body that flares upwards into a succession of well-layered gabbroic rocks of the Upper Mafic Sequence. No PGE mineralization has been found in the layered gabbro; all the mineralization is associated with the chromite- and sulfide-rich harzburgite of the Lower Ultramafic Sequence and the laterite regolith overlying the mineralized harzburgite. The Lubalisi Zone harzburgite is underlain by basal dunite and overlain by an interval of layered harzburgite and troctolite and this ultramafic sequence is folded into a syncline that plunges towards the northwest that has been modified by major dolerite-filled faults orientated subparallel to the fold axial surface. Extensive deep drilling in the Lubalisi Zone of the Kapalagulu Intrusion shows that the folded harzburgite can be subdivided into a lower feldspathic harzburgite, a harzburgite containing chromitite seams and intervals of sulfide and chromite mineralization known as the Main Chromite Sulfide Succession (MCSS), an overlying sulfide-rich harzburgite, and an upper feldspathic harzburgite. Impersistent, stratiform PGE mineralized horizons occur within the MCSS harzburgite from which drill core samples were taken for platinum-group mineral (PGM) characterization from two drill holes. Where the PGE reefs reach the surface there is residual PGE mineralization within the laterite regolith from which drill core samples were taken from various laterite lithological units for PGM characterization. As the harzburgite PGE reefs contain significant concentrations of both sulfide and chromite (including chromitite seams) they resemble the PGE-rich chromitite seams of the Bushveld Complex rather than the PGE-bearing Main Sulfide Zone of the Great Dyke and Main Sulfide Layer of the Munni Munni Complex. The dominant Pd PGM in three PGE reef samples varies, ranging ( n = 164, relative wt%) from bismuthides (63 %), bismuthtellurides (19 %), and tellurides (6 %), to tellurides (39 %), bismuthtellurides (24 %), stannides (14 %), and alloys (13 %), and to antimon-arsenides (33 %), stannides (21 %), bismuthides (17 %), tellurides (13 %), and alloys (10 %). From 13.5 % to 21.0 % of the total Pd occurs as a solid solution in pentlandite. The three samples have similar Pt PGM modal distributions ( n = 172, relative wt%); the dominant Pt mineral is sperrylite (79, 58, and 47 %) followed by tellurides (15, 17, 21 %), alloys (2, 1, 1 %), and sulfides (2, 1, 0 %). Comparison of Pd/Pt ratios from assays to those calculated from minerals show that the data for the Pt and Pd PGM are very robust, confirming the concentration methodology and characterization. Study of samples from a shallow drill hole penetrating the laterite regolith shows that the primary Pd mineralization has not survived oxidation, is mainly dispersed, but some was reconstituted to form secondary minerals: cabriite, unnamed tellurides, a selenide, a Pd-Te-Hg mineral, alloys and Pd-bearing secondary sulfides (millerite and heazlewoodite). The primary Pt minerals are more resistant to oxidation and dissolution, especially sperrylite and isoferroplatinum, but it is likely that other Pt alloys (tetraferroplatinum and tulameenite) are of secondary origin after dissolution of Pt tellurides.

  2. 43 CFR 19.8 - Prospecting, mineral locations, mineral patents, and mineral leasing within National Forest...

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    .... 2 of 43 CFR, which appears in Volume II of the List of CFR Sections Affected, 1964-1972, for the... 43 Public Lands: Interior 1 2011-10-01 2011-10-01 false Prospecting, mineral locations, mineral patents, and mineral leasing within National Forest Wilderness. 19.8 Section 19.8 Public Lands:...

  3. Electron microprobe mineral analysis guide

    NASA Technical Reports Server (NTRS)

    Brown, R. W.

    1980-01-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2014-09-01

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

  5. The Secondary Triad Model.

    ERIC Educational Resources Information Center

    Reis, Sally M.; Renzulli, Joseph S.

    1989-01-01

    The Secondary Triad Model aids in developing programs to serve secondary-level gifted/talented students. The model involves formation of: an Interdisciplinary Planning Team that organizes program goals and plans enrichment opportunities; and Talent Pool classes, in which the regular curriculum is compacted and students participate in

  6. Future of Secondary Services.

    ERIC Educational Resources Information Center

    Neufeld, M. Lynne

    1983-01-01

    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)

  7. Humanizing the Secondary School.

    ERIC Educational Resources Information Center

    Hamilton, Norman K., Ed.; Saylor, J. Galen, Ed.

    These papers, presented during ASCD-sponsored conference, confront educators with issues in and alternatives for making secondary schools a more humanizing experience for students. The contributors and their articles are: Norman K. Hamilton, "Alternatives in Secondary Education"; Thornton B. Monez and Norman L. Bussiere, "The High School in Human

  8. Secondary Education Transition Model.

    ERIC Educational Resources Information Center

    Colorado State Univ., Ft. Collins.

    The Secondary Education Transition Model project at Colorado State University-Fort Collins represents a local and state commitment to serve students with severe handicaps who are moving into community work and living roles. These comprehensive transition services begin at the secondary education level and extend into the adult service system. The

  9. Secondary fuel delivery system

    DOEpatents

    Parker, David M.; Cai, Weidong; Garan, Daniel W.; Harris, Arthur J.

    2010-02-23

    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.

  10. Mineral industries of the USSR - 1990

    SciTech Connect

    Not Available

    1991-01-01

    The report discusses mainly the mineral industries in the USSR, with a small section included concerning the mineral industries of Poland. Topics discussed include labor, foreign trade, metals, non-metallic minerals, and mineral fuels.

  11. Hearing protection for miners

    SciTech Connect

    Schulz, T.

    2008-10-15

    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.

  12. Nutrition or Detoxification: Why Bats Visit Mineral Licks of the Amazonian Rainforest

    PubMed Central

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

    2008-01-01

    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

  13. Study on comprehensive utilization of secondary resources

    SciTech Connect

    Lihua, G.; Ruilu, L.

    1995-12-31

    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.

  14. Economics of the Mineral Industries

    SciTech Connect

    Vogely, W.A.

    1985-01-01

    This edition of Economics of the Mineral Industries is completely rewritten to address the state of the mineral sectors and of mineral economic principles as of 1984. Since the 3rd edition was written in the early 1970s there have been major changes both in the structure of these industries and in the tools of analysis of them, as well as in public policy. This edition has three objectives: (1) to provide a book suitable for use in a wide variety of courses at universities and colleges; (2) to provide AIME members with a reference to which they can turn for an understanding of the principles and applications of economics, geostatistics, modeling, and other analytical techniques to the mineral industries; and (3) to provide an objective review of the public policy issues concerning minerals that the US faces. The book is divided into five parts: Minerals and the Economy; Principles of Mineral Economics; Mineral Industry Analysis; Structure and Performance of the Major Mineral Sectors; Public Policy and the Mineral Industries. There are 19 chapters or subchapters in the five sections.

  15. Microtextured Surfaces for Turbine Blade Impingement Cooling

    NASA Technical Reports Server (NTRS)

    Fryer, Jack

    2014-01-01

    Gas turbine engine technology is constantly challenged to operate at higher combustor outlet temperatures. In a modern gas turbine engine, these temperatures can exceed the blade and disk material limits by 600 F or more, necessitating both internal and film cooling schemes in addition to the use of thermal barrier coatings. Internal convective cooling is inadequate in many blade locations, and both internal and film cooling approaches can lead to significant performance penalties in the engine. Micro Cooling Concepts, Inc., has developed a turbine blade cooling concept that provides enhanced internal impingement cooling effectiveness via the use of microstructured impingement surfaces. These surfaces significantly increase the cooling capability of the impinging flow, as compared to a conventional untextured surface. This approach can be combined with microchannel cooling and external film cooling to tailor the cooling capability per the external heating profile. The cooling system then can be optimized to minimize impact on engine performance.

  16. Microtexture of Strain in electroplated copper interconnects

    SciTech Connect

    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

    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).

  17. Minerals Yearbook: Minerals in the world economy. 1988 International review

    SciTech Connect

    Kimbell, C.L.; Zajac, W.L.

    1988-01-01

    In overview, 1988 appeared to be the best year for the world's mineral industry since 1980, although the all-important petroleum component suffered severely from low prices. With this notable exception, the traditional statistical measures of mineral industry performance, namely production, trade, and consumption, reflected growth in most elements of the world mineral industry from crude material extraction through the gamut of downstream processing. Moreover, the growth was reasonably well distributed geographically, with many countries sharing in the substantial upturn in activity. The report discusses production, trade, consumption, investment, transportation, prices, and statistical summary of world production and trade of major mineral commodities.

  18. Mineral Time Capsules on Mars?

    NASA Technical Reports Server (NTRS)

    Schirber, Michael

    2006-01-01

    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.

  19. Microelectrophoresis of selected mineral particles

    NASA Technical Reports Server (NTRS)

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

    1982-01-01

    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.

  20. Acidophiles in bioreactor mineral processing.

    PubMed

    Norris, P R; Burton, N P; Foulis, N A

    2000-04-01

    Mineral processing in bioreactors has become established in several countries during the past decade with industrial application of iron- and sulfur-oxidizing bacteria to release occluded gold from mineral sulfides. Cobalt extraction in bioreactors has also been commercialized, and development of high-temperature biooxidation of copper sulfides has reached pilot-plant scale. A variety of potentially useful mineral sulfide-oxidizing thermophiles have been recognized, but the most active strains have not been fully characterized. PMID:10805560

  1. Paralysis: Secondary Conditions

    MedlinePLUS

    ... Secondary Conditions Autonomic Dysreflexia Bladder Management Bowel Management Deep Vein Thrombosis Depression Fitness and Exercise Nutirition Pain ... pain related to spinal cord injury or disease. Deep Vein Thrombosis (DVT) People with spinal cord injury ( ...

  2. Secondary extinctions of biodiversity.

    PubMed

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

    2014-12-01

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

  3. Personalizing Secondary Curriculum

    ERIC Educational Resources Information Center

    Bailey, William J.

    1974-01-01

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

  4. Secondary hyperkalaemic paralysis

    PubMed Central

    Evers, S.; Engelien, A.; Karsch, V.; Hund, M.

    1998-01-01

    Besides the hereditary hyperkalaemic paralysis, a secondary form exists which often mimicks Guillain-Barre syndrome. A 62year old patient is reported on who developed severe hyperkalaemic paralysis on the basis of mild renal failure and additive spironolactone intake. Neurophysiological examinations disclosed normal muscle fibre activity but delayed nerve conduction velocities indicating that the mechanism underlying secondary hyperkalaemic paralysis is different from channelopathies. Haemodialysis led to complete recovery. Review of the medical literature showed that spironolactone intake is the most common cause of secondary hyperkalaemic paralysis. Typical symptoms are flaccid tetraplegia sparing the cranial nerves with only mild or lacking sensory impairment. Symptoms promptly resolve after haemodialysis or after glucose and insulin infusion. Only three out of 18 patients reviewed died, because of cardiopulmonary complications. Thus the prognosis of secondary hyperkalaemic paralysis is good.?? PMID:9489541

  5. Mechanisms of primary mineral weathering inferred from B isotopes

    NASA Astrophysics Data System (ADS)

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

    2012-04-01

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

  6. Minerals Bill introduced in House

    NASA Astrophysics Data System (ADS)

    Richman, Barbara T.

    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.

  7. Thermodynamic properties of minerals

    USGS Publications Warehouse

    Robie, Richard A.

    1962-01-01

    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 298.15K (25.0C) and one atmosphere for minerals.

  8. Minerals yearbook, 1988: Thorium

    SciTech Connect

    Hedrick, J.B.

    1988-01-01

    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).

  9. Protein- mediated enamel mineralization

    PubMed Central

    Moradian-Oldak, Janet

    2012-01-01

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

  10. Pneumoconiosis of shale miners.

    PubMed Central

    Seaton, A; Lamb, D; Brown, W R; Sclare, G; Middleton, W G

    1981-01-01

    Four patients are described in whom pneumoconiosis was diagnosed towards the end of a lifetime's work in shale mines. All developed complicated pneumoconiosis, diagnosed in two cases at necropsy, in one by lobectomy, and in one radiologically. Two of the patients were found at necropsy also to have peripheral squamous lung cancer.The clinical and histological features of the disease resembled the pneumoconioses of coalminers and kaolin workers and the lungs of three of the patients were shown to contain dust composed predominantly of kaolinite, mica, and silica. Shale miners' complicated pneumoconiosis has not previously been described. Although the British shale industry is now defunct, oil production from shale is expanding in other countries, notably the USA. It is suggested that control should be exercised over dust exposure levels in this industry and that epidemiological studies should be carried out to quantify the risks of both pneumoconiosis and bronchial carcinoma. Images PMID:7314011

  11. Mineralization by nanobacteria

    NASA Astrophysics Data System (ADS)

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

    1998-07-01

    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.

  12. The Mineral Physics Committee

    NASA Astrophysics Data System (ADS)

    Mineral Physics Committee members for the period July 1, 1986, to J ne 30, 1988, have been announced. They are Murli H. Manghnani (Hawaii Institute of Geophysics, Honolulu), and Orson L. Anderson (University of California, Los Angeles), Thomas J. Ahrens (California Institute of Technology, Pasadena, Calif.), Subir K. Banerjee (University of Minnesota, Minneapolis), William A. Bassett (Cornell University, Ithaca, N.Y.), Gordon E. Brown, Jr. (Stanford University, Stanford, Calif.), Michael Brown (University of Washington, Seattle), Robert M. Hazen (Geophysical Laboratory, Washington, D.C.), Raymond F. Jeanloz (University of California, Berkeley), Robert C. Liebermann (State University of New York (SUNY),(Stony Brook), Alexandra Navrotsky (Princeton University, Princeton, N.J.), Robert N. Schock (Lawrence Livermore National Laboratory, Livermore, Calif.), and Donald J. Weidner (SUNY Stony Brook).

  13. Secondary pool boiling effects

    NASA Astrophysics Data System (ADS)

    Kruse, C.; Tsubaki, A.; Zuhlke, C.; Anderson, T.; Alexander, D.; Gogos, G.; Ndao, S.

    2016-02-01

    A pool boiling phenomenon referred to as secondary boiling effects is discussed. Based on the experimental trends, a mechanism is proposed that identifies the parameters that lead to this phenomenon. Secondary boiling effects refer to a distinct decrease in the wall superheat temperature near the critical heat flux due to a significant increase in the heat transfer coefficient. Recent pool boiling heat transfer experiments using femtosecond laser processed Inconel, stainless steel, and copper multiscale surfaces consistently displayed secondary boiling effects, which were found to be a result of both temperature drop along the microstructures and nucleation characteristic length scales. The temperature drop is a function of microstructure height and thermal conductivity. An increased microstructure height and a decreased thermal conductivity result in a significant temperature drop along the microstructures. This temperature drop becomes more pronounced at higher heat fluxes and along with the right nucleation characteristic length scales results in a change of the boiling dynamics. Nucleation spreads from the bottom of the microstructure valleys to the top of the microstructures, resulting in a decreased surface superheat with an increasing heat flux. This decrease in the wall superheat at higher heat fluxes is reflected by a "hook back" of the traditional boiling curve and is thus referred to as secondary boiling effects. In addition, a boiling hysteresis during increasing and decreasing heat flux develops due to the secondary boiling effects. This hysteresis further validates the existence of secondary boiling effects.

  14. Secondary psychoses: an update

    PubMed Central

    Keshavan, Matcheri S; Kaneko, Yoshio

    2013-01-01

    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

  15. Nitrogen Mineralization and Assimilation at Millimeter Scales

    SciTech Connect

    Cliff, John B.; Bottomley, Peter J.; Gaspar, Dan J.; Myrold, David D.

    2006-11-15

    This study used inoculated, artificial soil microcosms containing sand, clay, cellulose, and localized hotspots of highly labile, organic-N containing dead bacteria to study N mineralization and assimilation at submillimeter and centimeter scales. Labeling with 15NH4+ along with measurement of label assimilated into microbial biomass at the bulk scale allowed estimation of gross rates of ammonification and N assimilation using isotope dilution. Time-of-flight secondary ion mass spectrometry (ToF-SIMS) analyses of transects of organic-15N across Si wafers in contact with the microcosms indicated strong gradients of 15NH4+ assimilation as a function of proximity to the hotspots that were not apparent using bulk analyses. This combination of bulk and ToF-SIMS analyses represents a powerful approach to explore the physical and biochemical factors that affect N process heterogeneities in soils.

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

    NASA Astrophysics Data System (ADS)

    Jordan, Gyozo

    2009-07-01

    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.

  17. Biologically enhanced mineral weathering: what does it look like, can we model it?

    NASA Astrophysics Data System (ADS)

    Schulz, M. S.; Lawrence, C. R.; Harden, J. W.; White, A. F.

    2011-12-01

    The interaction between plants and minerals in soils is hugely important and poorly understood as it relates to the fate of soil carbon. Plant roots, fungi and bacteria inhabit the mineral soil and work symbiotically to extract nutrients, generally through low molecular weight exudates (organic acids, extracelluar polysachrides (EPS), siderophores, etc.). Up to 60% of photosynthetic carbon is allocated below ground as roots and exudates, both being important carbon sources in soils. Some exudates accelerate mineral weathering. To test whether plant exudates are incorporated into poorly crystalline secondary mineral phases during precipitation, we are investigating the biologic-mineral interface. We sampled 5 marine terraces along a soil chronosequence (60 to 225 ka), near Santa Cruz, CA. The effects of the biologic interactions with mineral surfaces were characterized through the use of Scanning Electron Microscopy (SEM). Morphologically, mycorrhizal fungi were observed fully surrounding minerals, fungal hyphae were shown to tunnel into primary silicate minerals and we have observed direct hyphal attachment to mineral surfaces. Fungal tunneling was seen in all 5 soils by SEM. Additionally, specific surface area (using a nitrogen BET method) of primary minerals was measured to determine if the effects of mineral tunneling are quantifiable in older soils. Results suggest that fungal tunneling is more extensive in the primary minerals of older soils. We have also examined the influence of organic acids on primary mineral weathering during soil development using a geochemical reactive transport model (CrunchFlow). Addition of organic acids in our models of soil development at Santa Cruz result in decreased activity of Fe and Al in soil pore water, which subsequently alters the spatial extent of primary mineral weathering and kaolinite precipitation. Overall, our preliminary modeling results suggest biological processes may be an important but underrepresented aspect of soil development in geochemical models.

  18. A Mineral Processing Field Course

    ERIC Educational Resources Information Center

    Carmody, Maurice

    2014-01-01

    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…

  19. From Mountain Men to Miners.

    ERIC Educational Resources Information Center

    Stevens, Robert L.; Fogel, Jared A.

    1999-01-01

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

  20. Investigating Minerals: Promoting Integrated Inquiry

    ERIC Educational Resources Information Center

    Thompson, Rudi; Carmack, Elizabeth

    2007-01-01

    "Mineral Detectives!" is one of eighteen lessons in the "Private Whys?" integrated science unit, which uses a guided inquiry investigation to teach students in grades three through five about the role of minerals in our lives. The University of North Texas developed "Private Whys?" with funding from the Copper Development Association. This lesson

  1. Minerals From the Marine Environment

    NASA Astrophysics Data System (ADS)

    Cruickshank, Michael J.

    The current interest in minerals centering on, among other things, potential shortages, long-term needs, and deep seabed nodules, accentuates the usefulness and timeliness of this little book authored by a former chairman of the British National Environmental Research Council.In less than 100 pages, the author puts into perspective the potential for producing minerals from offshore areas of the world. After introducing the reader to the ocean environment and the extraordinary variety of the nature of the seabed, the author describes in some detail the variety of minerals found there. This is done in seven separate chapters entitled Bulk and Non-Metallic Minerals From the Seas Metals From the Shallow Seas Metals From the Deep Oceans Minerals From Solution Oil and Gas from the Shallow Seas Oil and Gas From Deep Waters and Coal Beneath the Sea. The remaining chapters give a brief regional review of marine minerals distribution for eight areas of significant socioeconomic structure, and a short recapitulation of special problems of mineral recovery in the marine environment including such matters as the effect of water motion on mineral processing and of international law on investments. Glossaries of geological periods and technical terms, a short list of references, and an index complete the work.

  2. Investigating Minerals: Promoting Integrated Inquiry

    ERIC Educational Resources Information Center

    Thompson, Rudi; Carmack, Elizabeth

    2007-01-01

    "Mineral Detectives!" is one of eighteen lessons in the "Private Whys?" integrated science unit, which uses a guided inquiry investigation to teach students in grades three through five about the role of minerals in our lives. The University of North Texas developed "Private Whys?" with funding from the Copper Development Association. This lesson…

  3. Ways to defuse miners' anger

    SciTech Connect

    Not Available

    1984-06-01

    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.

  4. Mineral Resources and the Environment.

    ERIC Educational Resources Information Center

    National Academy of Sciences, Washington, DC.

    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,

  5. A Mineral Processing Field Course

    ERIC Educational Resources Information Center

    Carmody, Maurice

    2014-01-01

    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

  6. 76 FR 6110 - Conflict Minerals

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-03

    ... FR 80948 (December 23, 2010)]. The original comment period for Release No. 34-63547 is scheduled to... COMMISSION 17 CFR Parts 229 and 249 RIN 3235-AK84 Conflict Minerals AGENCY: Securities and Exchange... 1934 (the ``Exchange Act'') and would require any such issuer for which conflict minerals are...

  7. Evaporates, petroleum and mineral resources

    SciTech Connect

    Melvin, J.L.

    1991-01-01

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

  8. Renal Clearance of Mineral Metabolism Biomarkers.

    PubMed

    van Ballegooijen, Adriana J; Rhee, Eugene P; Elmariah, Sammy; de Boer, Ian H; Kestenbaum, Bryan

    2016-02-01

    CKD leads to disturbances in multiple interrelated hormones that regulate bone and mineral metabolism. The renal handling of mineral metabolism hormones in humans is incompletely understood. We determined the single-pass renal clearance of parathyroid hormone, fibroblast growth factor 23, vitamin D metabolites, and phosphate from paired blood samples collected from the abdominal aorta and renal vein in 17 participants undergoing simultaneous right and left heart catheterization and estimated associations of eGFR with the renal elimination of metabolites. The mean age ±SD of the study population was 71.4±10.0 years and 11 participants (65%) were male. We found a relatively large mean±SD single-pass renal extraction of parathyroid hormone (44.2%±10.3%) that exceeded the extraction of creatinine (22.1%±7.9%). The proportionate renal extraction of parathyroid hormone correlated with eGFR. The renal extraction of fibroblast growth factor 23 was, on average, lower than that of parathyroid hormone with greater variability across individuals (17.1%±19.5%). There were no differences in the mean concentrations of vitamin D metabolites across the renal vein and artery. In summary, we demonstrate substantial single-pass renal extraction of parathyroid hormone at a rate that exceeds glomerular filtration. Impaired renal clearance of parathyroid hormone may contribute to secondary hyperparathyroidism in CKD. PMID:26047790

  9. Adverse possession of subsurface minerals

    SciTech Connect

    Bowles, P.N.

    1983-01-01

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

  10. Ex situ aqueous mineral carbonation

    SciTech Connect

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

    2007-04-01

    The U.S. Department of Energy's National Energy Technology Laboratory (NETL) located in Albany, OR (formerly the Albany Research Center) has studied ex situ mineral carbonation as a potential option for carbon dioxide sequestration. Studies focused on the reaction of Ca-, Fe-, and Mg-silicate minerals with gaseous CO{sub 2} to form geologically stable, naturally occurring solid carbonate minerals. The research included resource evaluation, kinetic studies, process development, and economic evaluation. An initial cost estimate of about $69/ton of CO{sub 2} sequestered was improved with process improvements to about 54/ton. The scale of ex situ mineral carbonation operations, requiring about 55,000 tons of mineral to carbonate, the daily CO{sub 2} emissions from a 1-GW, coal-fired power plant, may make such operations impractical. 23 refs., 4 figs., 5 tabs.

  11. Ex Situ Aqueous Mineral Carbonation

    SciTech Connect

    Gerdemann, S.J.; O'Connor, W.K.; Dahlin, D.C.; Penner, L.R.; Rush, G.E.

    2007-04-01

    The U.S. Department of Energy's National Energy Technology Laboratory (NETL) located in Albany, OR (formerly the Albany Research Center) has studied ex situ mineral carbonation as a potential option for carbon dioxide sequestration. Studies focused on the reaction of Ca-, Fe-, and Mg-silicate minerals with gaseous CO2 to form geologically stable, naturally occurring solid carbonate minerals. The research included resource evaluation, kinetic studies, process development, and economic evaluation. An initial cost estimate of ~$69/ton of CO2 sequestered was improved with process improvements to ~$54/ton. The scale of ex situ mineral carbonation operations, requiring ~55 000 tons of mineral to carbonate, the daily CO2 emissions from a 1-GW, coal-fired power plant, may make such operations impractical.

  12. Universal ripper miner

    DOEpatents

    Morrell, Roger J.; Larson, David A.

    1991-01-01

    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.

  13. Miner's rule revisited

    NASA Astrophysics Data System (ADS)

    Schuetz, W.; Heuler, P.

    1994-03-01

    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.

  14. Moon's Pink Mineral

    NASA Astrophysics Data System (ADS)

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

    2014-12-01

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

  15. 43 CFR 3815.1 - Mineral locations.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 43 Public Lands: Interior 2 2014-10-01 2014-10-01 false Mineral locations. 3815.1 Section 3815.1..., DEPARTMENT OF THE INTERIOR MINERALS MANAGEMENT (3000) LANDS AND MINERALS SUBJECT TO LOCATION Mineral Locations in Stock Driveway Withdrawals 3815.1 Mineral locations. Under authority of the provisions of...

  16. 43 CFR 3816.1 - Mineral locations.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 43 Public Lands: Interior 2 2013-10-01 2013-10-01 false Mineral locations. 3816.1 Section 3816.1..., DEPARTMENT OF THE INTERIOR MINERALS MANAGEMENT (3000) LANDS AND MINERALS SUBJECT TO LOCATION Mineral Locations in Reclamation Withdrawals 3816.1 Mineral locations. The Act of April 23, 1932 (47 Stat. 136;...

  17. 43 CFR 3816.1 - Mineral locations.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 43 Public Lands: Interior 2 2012-10-01 2012-10-01 false Mineral locations. 3816.1 Section 3816.1..., DEPARTMENT OF THE INTERIOR MINERALS MANAGEMENT (3000) LANDS AND MINERALS SUBJECT TO LOCATION Mineral Locations in Reclamation Withdrawals 3816.1 Mineral locations. The Act of April 23, 1932 (47 Stat. 136;...

  18. 43 CFR 3816.1 - Mineral locations.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 43 Public Lands: Interior 2 2014-10-01 2014-10-01 false Mineral locations. 3816.1 Section 3816.1..., DEPARTMENT OF THE INTERIOR MINERALS MANAGEMENT (3000) LANDS AND MINERALS SUBJECT TO LOCATION Mineral Locations in Reclamation Withdrawals 3816.1 Mineral locations. The Act of April 23, 1932 (47 Stat. 136;...

  19. 43 CFR 3815.1 - Mineral locations.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 43 Public Lands: Interior 2 2013-10-01 2013-10-01 false Mineral locations. 3815.1 Section 3815.1..., DEPARTMENT OF THE INTERIOR MINERALS MANAGEMENT (3000) LANDS AND MINERALS SUBJECT TO LOCATION Mineral Locations in Stock Driveway Withdrawals 3815.1 Mineral locations. Under authority of the provisions of...

  20. 43 CFR 3815.1 - Mineral locations.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 43 Public Lands: Interior 2 2012-10-01 2012-10-01 false Mineral locations. 3815.1 Section 3815.1..., DEPARTMENT OF THE INTERIOR MINERALS MANAGEMENT (3000) LANDS AND MINERALS SUBJECT TO LOCATION Mineral Locations in Stock Driveway Withdrawals 3815.1 Mineral locations. Under authority of the provisions of...

  1. 43 CFR 3815.1 - Mineral locations.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 43 Public Lands: Interior 2 2011-10-01 2011-10-01 false Mineral locations. 3815.1 Section 3815.1..., DEPARTMENT OF THE INTERIOR MINERALS MANAGEMENT (3000) LANDS AND MINERALS SUBJECT TO LOCATION Mineral Locations in Stock Driveway Withdrawals 3815.1 Mineral locations. Under authority of the provisions of...

  2. 43 CFR 3816.1 - Mineral locations.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 43 Public Lands: Interior 2 2011-10-01 2011-10-01 false Mineral locations. 3816.1 Section 3816.1..., DEPARTMENT OF THE INTERIOR MINERALS MANAGEMENT (3000) LANDS AND MINERALS SUBJECT TO LOCATION Mineral Locations in Reclamation Withdrawals 3816.1 Mineral locations. The Act of April 23, 1932 (47 Stat. 136;...

  3. Secondary penile tumours revisited

    PubMed Central

    Cherian, Jacob; Rajan, Sreekumar; Thwaini, Ali; Elmasry, Yaser; Shah, Tariq; Puri, Rajiv

    2006-01-01

    Objective To highlight the salient features of metastatic malignancies involving the penis, with special reference to the primary tumour sites, metastatic mechanisms, clinical features, differential diagnosis, treatment and prognosis. Methods A comprehensive search of the literature was performed using MEDLINE and EMBASE, using the keywords 'penis', 'secondary malignancy', 'metastasis' and 'malignant priapism' to identify reviews and case reports of secondary penile malignancy. A case of rare clinical presentation of metastatic penile lesion is presented along with the review of the literature. Conclusion Secondary malignancy of the penis is a rare clinical entity, despite the rich vascularisation of this organ. The majority of metastatic lesions take their origin from the neighbouring genito-urinary organs, mainly prostate and bladder. These lesions are often associated with disseminated malignancy and hence have a poor outcome. Nodular or ulcerative lesions involving the corpora cavernosa or priapism are the main modes of clinical presentation. In most cases, only palliative or supportive therapy is indicated. PMID:17032461

  4. Secondary differential operators

    NASA Astrophysics Data System (ADS)

    Gusyatnikova, V. N.; Vinogradov, A. M.; Umaguzhin, V. A.

    Let ? be an arbitrary sustem of partial (non-linear differential equations. Higher infinitesimal sysmmetries of ? may be interpreted as vector fields on the manifold Sol ? of all local solution of this system. The paper deals with construction of differential operators of arbitrary orders on Sol ?. These approaches to construction of the theory of these operators, geometric and functional are presented, and their equivalence is proved when ? is the trivial equation. Coincidence of extrinsic and intrinsic geometric secondary operator is proved for an arbitrary system ?. It is shown that each geometric secondary operator may be approximated by a sum of compositions of evolution differentiations with any possible accuracy, a description of geometric secondary operators in local coordinates is algo given. These results are obtained by studying the geometry of finite jets and infinitely prolonged equations.

  5. Diagenesis and clay mineral formation at Gale Crater, Mars

    DOE PAGESBeta

    Bridges, J. C.; Schwenzer, S. P.; Leveille, R.; Westall, F.; Wiens, R. C.; Mangold, N.; Bristow, T.; Edwards, P.; Berger, G.

    2015-01-18

    The Mars Science Laboratory rover Curiosity found host rocks of basaltic composition and alteration assemblages containing clay minerals at Yellowknife Bay, Gale Crater. On the basis of the observed host rock and alteration minerals, we present results of equilibrium thermochemical modeling of the Sheepbed mudstones of Yellowknife Bay in order to constrain the formation conditions of its secondary mineral assemblage. Building on conclusions from sedimentary observations by the Mars Science Laboratory team, we assume diagenetic, in situ alteration. The modeling shows that the mineral assemblage formed by the reaction of a CO₂-poor and oxidizing, dilute aqueous solution (Gale Portage Water)more » in an open system with the Fe-rich basaltic-composition sedimentary rocks at 10–50°C and water/rock ratio (mass of rock reacted with the starting fluid) of 100–1000, pH of ~7.5–12. Model alteration assemblages predominantly contain phyllosilicates (Fe-smectite, chlorite), the bulk composition of a mixture of which is close to that of saponite inferred from Chemistry and Mineralogy data and to that of saponite observed in the nakhlite Martian meteorites and terrestrial analogues. To match the observed clay mineral chemistry, inhomogeneous dissolution dominated by the amorphous phase and olivine is required. We therefore deduce a dissolving composition of approximately 70% amorphous material, with 20% olivine, and 10% whole rock component.« less

  6. Diagenesis and clay mineral formation at Gale Crater, Mars

    NASA Astrophysics Data System (ADS)

    Bridges, J. C.; Schwenzer, S. P.; Leveille, R.; Westall, F.; Wiens, R. C.; Mangold, N.; Bristow, T.; Edwards, P.; Berger, G.

    2015-01-01

    Mars Science Laboratory rover Curiosity found host rocks of basaltic composition and alteration assemblages containing clay minerals at Yellowknife Bay, Gale Crater. On the basis of the observed host rock and alteration minerals, we present results of equilibrium thermochemical modeling of the Sheepbed mudstones of Yellowknife Bay in order to constrain the formation conditions of its secondary mineral assemblage. Building on conclusions from sedimentary observations by the Mars Science Laboratory team, we assume diagenetic, in situ alteration. The modeling shows that the mineral assemblage formed by the reaction of a CO2-poor and oxidizing, dilute aqueous solution (Gale Portage Water) in an open system with the Fe-rich basaltic-composition sedimentary rocks at 10-50C and water/rock ratio (mass of rock reacted with the starting fluid) of 100-1000, pH of ~7.5-12. Model alteration assemblages predominantly contain phyllosilicates (Fe-smectite, chlorite), the bulk composition of a mixture of which is close to that of saponite inferred from Chemistry and Mineralogy data and to that of saponite observed in the nakhlite Martian meteorites and terrestrial analogues. To match the observed clay mineral chemistry, inhomogeneous dissolution dominated by the amorphous phase and olivine is required. We therefore deduce a dissolving composition of approximately 70% amorphous material, with 20% olivine, and 10% whole rock component.

  7. Bisphophonates in CKD Patients with Low Bone Mineral Density

    PubMed Central

    Liu, Wen-Chih; Yen, Jen-Fen; Lu, Kuo-Cheng

    2013-01-01

    Patients with chronic kidney disease-mineral and bone disorder (CKD-MBD) have a high risk of bone fracture because of low bone mineral density and poor bone quality. Osteoporosis also features low bone mass, disarranged microarchitecture, and skeletal fragility, and differentiating between osteoporosis and CKD-MBD in low bone mineral density is a challenge and usually achieved by bone biopsy. Bisphosphonates can be safe and beneficial for patients with a glomerular filtration rate of 30?mL/min or higher, but prescribing bisphosphonates in advanced CKD requires caution because of the increased possibility of low bone turnover disorders such as osteomalacia, mixed uremic osteodystrophy, and adynamic bone, even aggravating hyperparathyroidism. Therefore, bone biopsy in advanced CKD is an important consideration before prescribing bisphosphonates. Treatment also may induce hypocalcemia in CKD patients with secondary hyperparathyroidism, but vitamin D supplementation may ameliorate this effect. Bisphosphonate treatment can improve both bone mineral density and vascular calcification, but the latter becomes more unlikely in patients with stage 3-4 CKD with vascular calcification but no decreased bone mineral density. Using bisphosphonates requires considerable caution in advanced CKD, and the lack of adequate clinical investigation necessitates more studies regarding its effects on these patients. PMID:24501586

  8. Diagenesis and clay mineral formation at Gale Crater, Mars

    PubMed Central

    Bridges, J C; Schwenzer, S P; Leveille, R; Westall, F; Wiens, R C; Mangold, N; Bristow, T; Edwards, P; Berger, G

    2015-01-01

    The Mars Science Laboratory rover Curiosity found host rocks of basaltic composition and alteration assemblages containing clay minerals at Yellowknife Bay, Gale Crater. On the basis of the observed host rock and alteration minerals, we present results of equilibrium thermochemical modeling of the Sheepbed mudstones of Yellowknife Bay in order to constrain the formation conditions of its secondary mineral assemblage. Building on conclusions from sedimentary observations by the Mars Science Laboratory team, we assume diagenetic, in situ alteration. The modeling shows that the mineral assemblage formed by the reaction of a CO2-poor and oxidizing, dilute aqueous solution (Gale Portage Water) in an open system with the Fe-rich basaltic-composition sedimentary rocks at 10–50°C and water/rock ratio (mass of rock reacted with the starting fluid) of 100–1000, pH of ∽7.5–12. Model alteration assemblages predominantly contain phyllosilicates (Fe-smectite, chlorite), the bulk composition of a mixture of which is close to that of saponite inferred from Chemistry and Mineralogy data and to that of saponite observed in the nakhlite Martian meteorites and terrestrial analogues. To match the observed clay mineral chemistry, inhomogeneous dissolution dominated by the amorphous phase and olivine is required. We therefore deduce a dissolving composition of approximately 70% amorphous material, with 20% olivine, and 10% whole rock component. PMID:26213668

  9. Diagenesis and clay mineral formation at Gale Crater, Mars

    SciTech Connect

    Bridges, J. C.; Schwenzer, S. P.; Leveille, R.; Westall, F.; Wiens, R. C.; Mangold, N.; Bristow, T.; Edwards, P.; Berger, G.

    2015-01-18

    The Mars Science Laboratory rover Curiosity found host rocks of basaltic composition and alteration assemblages containing clay minerals at Yellowknife Bay, Gale Crater. On the basis of the observed host rock and alteration minerals, we present results of equilibrium thermochemical modeling of the Sheepbed mudstones of Yellowknife Bay in order to constrain the formation conditions of its secondary mineral assemblage. Building on conclusions from sedimentary observations by the Mars Science Laboratory team, we assume diagenetic, in situ alteration. The modeling shows that the mineral assemblage formed by the reaction of a CO₂-poor and oxidizing, dilute aqueous solution (Gale Portage Water) in an open system with the Fe-rich basaltic-composition sedimentary rocks at 10–50°C and water/rock ratio (mass of rock reacted with the starting fluid) of 100–1000, pH of ~7.5–12. Model alteration assemblages predominantly contain phyllosilicates (Fe-smectite, chlorite), the bulk composition of a mixture of which is close to that of saponite inferred from Chemistry and Mineralogy data and to that of saponite observed in the nakhlite Martian meteorites and terrestrial analogues. To match the observed clay mineral chemistry, inhomogeneous dissolution dominated by the amorphous phase and olivine is required. We therefore deduce a dissolving composition of approximately 70% amorphous material, with 20% olivine, and 10% whole rock component.

  10. Secondary-containment piping

    SciTech Connect

    Elgendy, F.; Paul, B.O.; Hrickiewicz, M.

    1996-09-01

    Secondary-containment, or {open_quotes}double-wall,{close_quotes} piping systems are substantially more expensive and more difficult to design and install than conventional single-wall piping systems. However, they are required by law for a number of hazardous applications, including underground storage tanks for lethal, hazardous and regulated chemicals; landfills and leachate collection systems; industrial wastewater drain systems; and many other operations such as fuel depots. This article discusses the evaluation, design, and system and manufacturer selection process of secondary-containment piping systems for chemical plant and industrial waste processing.

  11. Capture probabilities for secondary resonances

    NASA Technical Reports Server (NTRS)

    Malhotra, Renu

    1990-01-01

    A perturbed pendulum model is used to analyze secondary resonances, and it is shown that a self-similarity between secondary and primary resonances exists. Henrard's (1982) theory is used to obtain formulas for the capture probability into secondary resonances. The tidal evolution of Miranda and Umbriel is considered as an example, and significant probabilities of capture into secondary resonances are found.

  12. Stability of Minerals in a Plasma

    NASA Astrophysics Data System (ADS)

    Kern, C. M.; Witkowski, R. E.; Cassidy, W. A.

    1993-07-01

    We report here the results of an experiment designed to determine whether a group of silicate, oxide, sulfide, and metal substrates would remain stable or decompose under the highly energetic conditions of a plasma in which diamonds can form metastably. Using a microwave plasma reactor, we exposed the substrates to a plasma consisting of 99.5% hydrogen and 0.5% methane for 24 hr. The temperature of the substrate was approximately 950 degrees C, the pressure of the vacuum chamber was approximately 45 mbar, and the flow rate of the gas mix was approximately 200 cm^3/s. The silicate substrates were olivine, plagioclase, augite, nepheline, pyrope, hornblende, serpentine, and phlogopite; oxide substrates were magnetite and hematite; sulfide substrates were troilite, pentlandite, and pyrrhotite; and metal substrates were iron, nickel, kamacite, and taenite. Metastable diamonds formed on all the silicate substrates except nepheline. There was no diamond formation on any of the oxide, sulfide, or metal substrates. In every instance where diamonds did not grow the substrates were covered with thick secondary deposits. A substantial amount of pitting was observed on the surfaces of all the silicate substrates except nepheline. There is evidence for the loss of a substantial amount of silicon from at least three silicate substrates (e.g., plagioclase, anorthite, and pyrope in a Ca-rich groundmass). A thick layer of platelike Al-rich secondary deposits (possibly metallic Al and/or corundum) formed on the nepheline substrate. The magnetite, hematite, troilite, pentlandite, pyrrhotite, iron, kamacite, and taenite substrates decomposed significantly. Thick, dark, highly porous secondary iron-rich deposits formed on the surfaces of these substrates. These iron-rich deposits may consist of metallic Fe, FeC, and/or FeS and may be reaction products resulting from the interaction of the plasma and substrates. Other secondary deposits common to the silicates were iron (possibly in the form of metallic Fe, iron carbide, and/or iron sulfide) and calcium (possibly in the form of elemental Ca and/or oldhamite). Secondary iron typically formed porous, loosely bound aggregates, often containing small (0.1-micrometer) spheroids. Fibers approximately 0.05 micrometers in diameter and 10-30 micrometers in length were observed on substrates containing a substantial amount of Ca (e.g., plagioclase, augite, anorthite, and pyrope in a Ca-rich groundmass). The initial presence of Ca in the substrates, loss of Si from the substrates, and growth of fibers on substrates may be related. Samples were run in groups of seven and secondary mineral formation, at least in part, resulted from cross contamination. We can infer from this cross contamination that Fe, Si, Ca, and S were fractionated from some substrates, incorporated into the plasma, and then deposited in different morphologic forms. These forms include fibers, fibrous networks, iron-rich, porous, loosely bound aggregates, and spheroids. The pressure and temperature conditions used in this experiment can be found in the atmospheres of red giant stars. The results of this experiment suggest that most of the minerals used as substrates would not be stable under conditions that favor the metastable growth of diamonds. However, morphologic structures similar to those produced on the substrates in this experiment may also exist in the atmospheres of red giant stars.

  13. Microbial mineral colonization across a subsurface redox transition zone

    PubMed Central

    Converse, Brandon J.; McKinley, James P.; Resch, Charles T.; Roden, Eric E.

    2015-01-01

    This study employed 16S rRNA gene amplicon pyrosequencing to examine the hypothesis that chemolithotrophic Fe(II)-oxidizing bacteria (FeOB) would preferentially colonize the Fe(II)-bearing mineral biotite compared to quartz sand when the minerals were incubated in situ within a subsurface redox transition zone (RTZ) at the Hanford 300 Area site in Richland, WA, USA. The work was motivated by the recently documented presence of neutral-pH chemolithotrophic FeOB capable of oxidizing structural Fe(II) in primary silicate and secondary phyllosilicate minerals in 300 Area sediments and groundwater (Benzine et al., 2013). Sterilized portions of sand+biotite or sand alone were incubated in situ for 5 months within a multilevel sampling (MLS) apparatus that spanned a ca. 2-m interval across the RTZ in two separate groundwater wells. Parallel MLS measurements of aqueous geochemical species were performed prior to deployment of the minerals. Contrary to expectations, the 16S rRNA gene libraries showed no significant difference in microbial communities that colonized the sand+biotite vs. sand-only deployments. Both mineral-associated and groundwater communities were dominated by heterotrophic taxa, with organisms from the Pseudomonadaceae accounting for up to 70% of all reads from the colonized minerals. These results are consistent with previous results indicating the capacity for heterotrophic metabolism (including anaerobic metabolism below the RTZ) as well as the predominance of heterotrophic taxa within 300 Area sediments and groundwater. Although heterotrophic organisms clearly dominated the colonized minerals, several putative lithotrophic (NH4+, H2, Fe(II), and HS- oxidizing) taxa were detected in significant abundance above and within the RTZ. Such organisms may play a role in the coupling of anaerobic microbial metabolism to oxidative pathways with attendant impacts on elemental cycling and redox-sensitive contaminant behavior in the vicinity of the RTZ. PMID:26379637

  14. Economic drivers of mineral supply

    USGS Publications Warehouse

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

    2003-01-01

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

  15. BET Measurements: Outgassing of Minerals.

    PubMed

    Clausen; Fabricius

    2000-07-01

    Outgassing minerals at elevated temperatures prior to BET measurements can lead to phase changes, especially in the case of amorphous and poorly crystalline materials. In order to evaluate the applicability of the BET method when low outgassing temperatures are required, selected aquifer minerals were outgassed at different temperatures and for different times. The studied minerals are 2-line ferrihydrite, goethite, lepidocrocite, quartz, calcite, alpha-alumina, and kaolinite. The results demonstrate that measured specific surface areas of iron oxides are strongly dependent on outgassing conditions because the surface area increased by 170% with increasing temperature. In the poorly crystalline minerals, phase changes caused by heating were observed at temperatures lower than 100 degrees C. Therefore low outgassing temperatures are preferable for minimizing phase changes. As demonstrated in this study, stable BET values can be obtained by increasing the outgassing time without heating iron oxides. For quartz, calcite, alpha-alumina, and kaolinite, stable BET values were obtained after outgassing the minerals at 100 to 250 degrees C for 2 h. However, outgassing these minerals at room temperature (20 degrees C) only resulted in minor errors, implying that aquifer sediments containing poorly crystalline materials can be outgassed at low temperatures if the outgassing time is increased. Scanning electron microscopy of the studied minerals demonstrated that the particle size as calculated from BET data compares well with particle size observed by scanning electron microscopy images. Copyright 2000 Academic Press. PMID:10860588

  16. Mineral induction by immobilized phosphoproteins

    NASA Technical Reports Server (NTRS)

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

    1997-01-01

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

  17. Mineral Commodity Profiles -- Rubidium

    USGS Publications Warehouse

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

    2003-01-01

    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.

  18. Assessment of the geoavailability of trace elements from selected zinc minerals

    USGS Publications Warehouse

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

    2014-01-01

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

  19. Mineral Losses During Extreme Environmental Conditions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Advisory groups that make recommendations for mineral intakes continue to identify accurate determinations of sweat mineral losses during physical activity as a critical void in their deliberations. Although estimates of sweat mineral concentrations are available, they are highly variable. Practica...

  20. Secondary Education in Austria.

    ERIC Educational Resources Information Center

    Aigner, Helmut

    This booklet provides a brief description of secondary education in Austria. The publication is part of a series that seeks to make the public aware of the education systems and traditions in all signatory states to the European Cultural Convention and to outline the essential problems these systems presently are facing. This short booklet

  1. Aircraft Electric Secondary Power

    NASA Technical Reports Server (NTRS)

    1983-01-01

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

  2. Modernising Portugal's Secondary Schools

    ERIC Educational Resources Information Center

    Heitor, Teresa V.

    2008-01-01

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

  3. Secondary Education in Switzerland.

    ERIC Educational Resources Information Center

    Sauthier, Roger

    This booklet provides a brief description of secondary education in Switzerland. The publication is part of a series that seeks to make the public aware of the education systems and traditions in all signatory states to the European Cultural Convention and to outline the essential problems these systems presently are facing. This short booklet

  4. From Primary to Secondary

    ERIC Educational Resources Information Center

    Anderson, Lyn

    2011-01-01

    This author discusses her decision to move to secondary school to teach mathematics, after having taught and been a mathematics manager in primary schools for six years. She states that this was a valuable experience and sparked her interest in the transition experiences of students, particularly in mathematics. Research (Evangelou et al, 2008,

  5. Secondary impact hazard assessment

    NASA Technical Reports Server (NTRS)

    1986-01-01

    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.

  6. Influence of abiotic stress signals on secondary metabolites in plants.

    PubMed

    Ramakrishna, Akula; Ravishankar, Gokare Aswathanarayana

    2011-11-01

    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

  7. Influence of abiotic stress signals on secondary metabolites in plants

    PubMed Central

    Ramakrishna, Akula; Ravishankar, Gokare Aswathanarayana

    2011-01-01

    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

  8. Effect of the advent and diversification of vascular land plants on mineral weathering through geologic time

    NASA Astrophysics Data System (ADS)

    Knoll, Martin A.; Calvin James, W.

    1987-12-01

    The origin of vascular land plants in the Silurian and their subsequent diversification have had a major effect on mineral weathering through geologic tune. The presence of vascular plants reduces the stability of soil minerals through a net export of ions from soil waters and through the release of complexing organic acids by root mycorrhizae. Additional factors that dictate the nature of plant-induced mineral weathering are (1) the differences in nutrient dynamics between evergreen and deciduous species; (2) the role of specific nutrient sinks (biomass storage and secondary soil mineralization) and outputs (runoff, etc.) in plant ecosystems; and (3) the effect of long- and short-term ecosystem disturbances. First-order increases in overall mineral weathering probably took place in the middle Paleozoic and early Tertiary, following the initial colonization and diversification of land plants and the radiation of deciduous angiospenns. Second-order fluctuations would typify time intervals where paleoecosystem disturbances were maximized, such as periods of climatic instability.

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

    PubMed

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

    2011-09-15

    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

  10. Modeling results of calcium-containing minerals precipitation in the alkaline hydrotherms of Baikal Rift Zone: calcite and dolomite

    NASA Astrophysics Data System (ADS)

    Tokarenko, O. G.; Zippa, E. V.

    2015-11-01

    The calculation modeling results of the nitric hydrotherms saturation in Baikal Rift Zone with calcite and dolomite are presented. The calcite and dolomite make the carbonate barrier to thermal waters equilibrium with primary minerals of igneous rocks. In the research territory, there are three main types of geochemical thermal waters which are characterized by the saturation degree with the calcite and dolomite and the proportion of precipitating minerals phases. It has been established that nitric thermal waters-rock system has equilibrium with these minerals, which leads to bonding migrated from the rocks calcium and magnesium by the secondary formed minerals - calcite and dolomite.

  11. Secondary Hyperparathyroidism in Patients with Endemic Skeletal Fluorosis

    PubMed Central

    Teotia, S. P. S.; Teotia, Mohini

    1973-01-01

    Investigation of 20 patients with skeletal fluorosis showed that five had clear evidence of secondary hyperparathyroidism. The hyperactivity of the parathyroid glands in skeletal fluorosis in the presence of decreased solubility of the bone mineral (fluoroapatite) strongly suggests that it is a compensatory attempt to maintain a normal extracellular ionized calcium equilibrium. Further study of the parathyroid glands and of bone lesions in skeletal fluorosis is in progress. ImagesFIG. 1FIG. 2FIG. 3FIG. 4 PMID:4692708

  12. Designing Clothing for Coal Miners

    ERIC Educational Resources Information Center

    Watkins, Susan M.

    1977-01-01

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

  13. Mineral and water nutrition.

    PubMed

    Beede, D K

    1991-07-01

    In providing minerals to dairy cattle it is important to distinguish between dietary requirements and feeding recommendations. The requirement is the absolute amount of an element needed to meet the animal's metabolic needs for maintenance, growth, pregnancy, and lactation divided by the coefficient of absorption; this is estimated by the factorial method. Actual estimates of requirements for lactating dairy cattle have been determined for Ca and P. The major difficulties in relying on the requirement estimate are that dry matter intake varies and the true absorption coefficient of the mixture of feeds in the ration generally is unknown. Therefore, feeding recommendations, based on feeding graded concentrations of an element, often offer more applicable information. With the exception of Ca and P, the current feeding recommendations for the other macrominerals, Mg, Na, K, Cl and S, have resulted from feeding trials. With certain environmental and physiologic situations the feeding recommendations may vary. For example, during heat stress the dietary K recommendation for the lactating cow should be higher than in cool weather because of increased sweating and decreased feed intake. Another example may be that the source of supplemental Mg may affect what dietary inclusion rate will yield optimal performance and should be recommended. An important consideration in dairy ration formulation in the future will address the interrelationships of the various macrominerals. There is accumulating evidence that shows that different concentrations of Na, Cl, and K may interrelate and affect lactational performance. Many times the naturally occurring concentrations of one or more of these elements may have to be associated with varying concentrations of the others in order to optimize animal performance and health. Much experimentation likely will examine these interrelationships in the future. Supplementation of trace elements in diets of dairy cattle is common practice. This is because the quantities found in common feedstuffs are relatively low relative to the animal's needs and vary considerably among and within feeds. Supplementation provides a safety margin against potential deficiency. The reader is cautioned to consult other publications regarding potential interactions among the trace elements and their interactions with other nutrients. Potential oversupplementation is a real concern. Maximum safe tolerance concentrations for most trace elements are available. Water is the most important indispensable nutrient. Water requirements are affected by physiologic state and rate of milk yield, body weight, rate of dry matter intake, Na intake, and average minimum environmental temperature. Practically, offering a fresh, abundant supply of easily accessible drinking water at all times is essential.(ABSTRACT TRUNCATED AT 400 WORDS) PMID:1893277

  14. Intermediate-depth earthquake generation: what hydrous minerals can tell us

    NASA Astrophysics Data System (ADS)

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

    2012-04-01

    Subduction zone seismicity has commonly been causally related to the dehydration of minerals within the subducting slab(Hacker et al. 2004, Jung et al. (2004), Dobson et al. 2002, Rondenay et al. 2008). Other models for release of intermediate- and deep earthquakes include spontaneous reaction(s) affecting large rock-bodies along overstepped phase boundaries ( e.g. Green and Houston, 1995) and various shear heating-localization models (e.g. Kelemen and Hirth 2007, John et al. 2009). These concepts are principally reliant on seismic and thermo-petrological modeling; both of which are indirect methods of analysis. Recent discoveries of pseudotachylytes (PST) formed under high pressure conditions (Ivrea-Verbano Zone, Italy, Western Gneiss Region, Norway and Corsica) provide the first tangible opportunity to evaluate these models (Austrheim and Andersen, 2004, Lund and Austrheim, 2003, Obata and Karato, 1995, Jin et al., 1998). This case study focuses on observations based on ultramafic and mafic PST within the Ligurian Ophiolite of the high pressure-low temperature metamorphic (HP-LT) 'Shistes Lustres' complex in Cima di Gratera, Corsica (Andersen et al. 2008). These PST have been preserved in pristine lenses of peridotite and gabbro surrounded by schistose serpentinites. The PST range in thickness from 1mm to 25 cm (Andersen and Austrheim, 2006). Petrography and geochemistry on PST from the peridotite and gabbro samples indicates that total/near-total fusion of the local host rock mineral assemblage occurred; bringing up the temperature of shear zone from 350° C to 1400 - 1700° C; depending on the host rock (Andersen and Austrheim, 2006). The composition of the PST is highly variable, even at the thin section scale and this has been attributed to the coarse-grained nature of the host rock, its small scale inhomogeneity and poor mixing of the fusion melt. Almost all the bulk analyses of the PST are hydrous; the peridotitic PST is always hydrous (H2O content from 3.8 to 14 wt %) but the gabbro is not (H2O content from 0 to 2.6 wt%). The hydrous nature of the PST is due to the preferential melting of hydrous minerals (chlorite and serpentine - peridotite, glaucophane, epidote, Mg-hornblende - gabbro) in the host rock, rather than later hydration associated with exhumation (greenschist facies metamorphism and later alteration). However, in the case of the gabbro, the melt can be hydrous, but is not always. Anhydrous, glassy PST is formed in association with hydrous PST in the gabbro host rock. The gabbroic PST nucleate at the boundary between a coarse-grained pegmatoidal gabbro and a fine-grained gabbro, whereas the exclusively hydrous peridotite-hosted PST only nucleate along pre-existing hydrated fractures. These facts are significant when considering the mechanism of formation of the pseudotachylyte; which is commonly thought to be associated with the preferential melting of hydrous minerals. An anhydrous melt in proximity to other hydrous melts formed contemporaneously must have formed by the same mechanism; one which can exploit more than just one rheological characteristic in the rock vis. hydrous mineralogy AND grain size changes. Furthermore the presence of anhydrous PST suggests that little or no fluid ingress occurred prior to or during PST generation. Hydrous crystallisation products in the gabbro such as glaucophane and edenite indicate that whole-sale melting of the wallrock amphiboles (glaucophane, edenite, actinolite) took place to produce a melt with dissolved H2O, out of which such blue amphiboles were able to crystallise. It is important to note that in order for amphiboles to crystallise out of a melt, H2O is required but necessarily to an under-saturated degree. i.e. it cannot be 'free' water occurring as a separate phase in the melt (Carmen and Gilbert, 1983 and Koons, 1982). It is unlikely therefore that the water in the gabbro-derived fusion melt was the result of solid-state dehydration of the wallrock amphiboles. Microtextural observations of sheared out, kinked, twinned, prolate wallrock grains millimetres from vein boundaries and thermally rounded clasts, similarly deformed, entrained into the melt suggest that the process initiating fusion melting and seismic failure is spatially and temporally related to a high temperature ductile process rather than a brittle one. Together, the microtextural and geochemical observations provide ample support for a ductile thermal run-away process to initiate high pressure PST development and seismic failure and preclude dehydration embrittlement.

  15. Mineral of the month: magnesium

    USGS Publications Warehouse

    Kramer, Deborah A.

    2005-01-01

    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.

  16. The Zapot pegmatite mineral county

    USGS Publications Warehouse

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

    1999-01-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2013-12-01

    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) μmol/ mmol of the 13:15N labeled free amino acids were mineralized over the 7-day incubations. By contrast, 186 (× 97) μmol/ 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.

  18. 30 CFR 57.22608 - Secondary blasting (I-A, II-A, and V-A mines).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Safety Standards for Methane in Metal and Nonmetal Mines Explosives 57.22608 Secondary... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Secondary blasting (I-A, II-A, and V-A...

  19. 30 CFR 57.22608 - Secondary blasting (I-A, II-A, and V-A mines).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Safety Standards for Methane in Metal and Nonmetal Mines Explosives 57.22608 Secondary... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Secondary blasting (I-A, II-A, and V-A...

  20. Minerals in the world economy. Minerals yearbook Volume 3. 1991 international review

    SciTech Connect

    Kimbell, C.L.

    1991-12-31

    This edition of the Minerals Yearbook - International Review records the performance of the worldwide minerals industry during 1991 and provides background information to assist in interpreting that performance. Volume III, International Review, contains the latest available mineral data on more than 150 foreign countries and discusses the importance of minerals to the economies of these nations. The 1991 review is presented as five area reports and one world overview: Mineral Industries of Africa, Mineral Industries of Asia and the Pacific, Mineral Industries of Latin America and Canada, Mineral Industries of Europe and the U.S.S.R., Mineral Industries of the Middle East, and Minerals in the World Economy.

  1. Defining reactive sites on hydrated mineral surfaces: Rhombohedral carbonate minerals

    NASA Astrophysics Data System (ADS)

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

    2009-08-01

    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 ΣCO 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.

  2. Secondaries near Cerberus

    NASA Technical Reports Server (NTRS)

    2006-01-01

    7 January 2006 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows a field of small craters formed by secondary debris thrown from a larger meteoritic impact on the plains south of the Cerberus region.

    Location near: 2.3oN, 195.7oW Image width: 3 km (1.9 mi) Illumination from: lower left Season: Northern Winter

  3. The Trouble With Tailings: How Alteration Mineralogy can Hinder Quantitative Phase Analysis of Mineral Waste

    NASA Astrophysics Data System (ADS)

    Wilson, S. A.; Mills, S. J.; Dipple, G. M.; Raudsepp, M.

    2009-05-01

    Quantitative phase analysis, using the Rietveld method and X-ray powder-diffraction data, has become a standard technique for analysis of mineral waste from mining operations. This method relies upon the availability of well defined crystal structures for all detectable mineral phases in a sample. An even more basic assumption, central to quantitative mineralogy, is that all significant mineral phases can be detected from X-ray diffraction data. This is not always the case, because X-ray amorphous and nanocrystalline mineral phases can develop within geological samples as a result of chemical weathering. The extent of mineral-water interaction to which mine tailings are exposed, during processing and storage, makes these materials particularly susceptible to weathering and alteration. We have used the Rietveld method and X-ray powder-diffraction data to quantify the uptake of atmospheric CO2 into secondary carbonate minerals at two operating mines: the Diavik Diamond Mine, Northwest Territories, Canada, and the Mount Keith Nickel Mine, Western Australia, Australia. At Diavik, nominally anhydrous minerals in kimberlitic mine tailings have been found to contain X-ray amorphous material and hydroxyl groups detectable by Raman spectroscopy. A series of weighed mixtures, prepared to simulate kimberlite mine tailings, has been used to assess the effects of X-ray amorphous material on quantitative phase analysis of Diavik tailings. At Mount Keith, hydrated sulphate minerals and halide minerals develop efflorescent crusts at the surface of the tailings storage facility. Hydrated sulphate minerals in these mine tailings commonly decompose to amorphous substances rather than dehydrating to produce minerals detectable from X-ray powder-diffraction patterns. Nanocrystalline and X-ray amorphous material in mine tailings can affect the accuracy of quantitative determinations of CO2 trapping and abundances of sulphur-bearing minerals associated with redox reactions. Here we assess the impact of amorphous material on quantitative X-ray diffraction results with particular reference to CO2 sequestration and suggest strategies for detection and analysis.

  4. Minerals from a strategic viewpoint. [From 1980 Mineral Economics Symposium

    SciTech Connect

    Morgan, J.D. Jr.

    1981-01-01

    Adequate supplies of virtually all materials, including minerals and food, are essential to national security in the sense that a strong economy is as vital as military strength. The US has recognized the strategic importance of minerals and its vulnerability for over a century, but the problem will intensify with accelerating defense and energy programs. A broad spectrum of nonfuel minerals play a major part in the international commodity trade, giving them political and economic importance. An assessment of US vulnerability in competitive markets must consider the positions of its allies in comparison with the Soviet bloc position. Numerous marginal and submarginal domestic deposits and recovery opportunities have been identified in the event that a defense mobilization becomes necessary through the amended Defense Production Act of 1950, which provides the authority and funding. The government has identified 93 materials with import vulnerability for stockpiling. Other efforts include substitution, accelerated amortization as an investment incentive for domestic mineral exploration and production, and a review of minerals policies affecting allocations and priorities during a supply shortage. 3 figures, 1 table. (DCK)

  5. [Mineral water as a cure].

    PubMed

    Nocco, Priska Binz

    2008-01-01

    The treatment of diseases with mineral spring water belongs to the oldest medical therapies. The "remedy" mineral water is therefore of importance also within the pharmacy. The present pharmacy historical work examines the impact of the use of mineral waters, as well as of their dried components, as therapeutic agents in the 19th and early 20th centuries, i.e. from approx. 1810 to 1930, as well as the contributions given by pharmacists in the development and analysis of mineral water springs. Beside these aspects, the aim here is also to describe the role played by pharmacists in the production of artificial mineral water as well as in the sale and wholesale of natural and artificial mineral water. In the first part of this work the situation in Switzerland and its surrounding countries, such as Germany, France, Italy and Austria, is discussed. The second part contains a case-study of the particular situation in the Canton Tessin. It is known from the scientific literature published at that time that information on mineral water was frequently reported. Starting from the beginning of the 19th century the number of such publications increased tremendously. The major part of them were publications in scientific journals or contributions to medical and pharmaceutical manuals and reference books. In particular the spa-related literature, such as spa-guides, was of growing interest to a broad public. The inclusion of monographs into the Swiss, the Cantonal as well the foreign pharmacopoeias granted a legal frame for the mineral waters and their dried components. These works are of major importance from a pharmacy historical standpoint and represent a unique proof of historical evidence of the old medicinal drug heritage. The most frequently used therapies based on mineral waters were drinking and bath cures. Several diseases, particularly those of a chronic character, were treated with mineral waters. The positive influence of these cures on the recovery of the patients was to attribute, on the one hand to the physico-chemical properties of the water and on the other hand to the climatic, nutritional and social factors characterising the selected health resort. All over Europe, pharmacists were dealing with mineral waters, among them even very famous names such as Klaproth, Trommsdorf, Lampadius and Fresenius. They were on one side involved in the development and analysis of the waters, while on the other side they were interested in their artificial production. Their knowledge and findings in the area of the mineral water source chemistry gave a crucial impetus to the future evolution of analytic chemistry. Following the improvements in the precision of analysis and classification of the composition of the mineral waters, the imitation of artificial mineral waters increased significantly. Certain pharmacists tried to copy well-known mineral waters in their properly furnished laboratories. At the same time, pharmacies were important sales points: natural and artificial mineral waters as well as their dried components were either sold there, or delivered upon prescription. In the second part of this work, specifically concerning the situation in the Canton Tessin, the most important local sources and spa resorts are described, as well as the analyses performed and the researchers involved. Moreover, the types of therapies used at that time are mentioned. The integration of the local mineral waters into the pharmacopoeia of the Canton Tessin, the Farmacopea Ticinese, is also discussed. Of particular interest are the delivery and the sale of mineral waters and their dried components by a local pharmacy. In the Canton Tessin, the five most frequented spa resorts were Acquarossa, Brissago, Craveggia, Rovio and Stabio. Craveggia spa resort is of course based in Italy; it has however been included in the present work due to its proximity to Switzerland and to a connected historical Substantial differences existed among the individual health resorts mentioned, especially regarding the quality and quantity aspects of the performed mineral water analyses, as well as in the reported written evidence and publications on the success of the therapies. Differences were also to be found in the conditions of the health resort facilities and in the medical support given. The therapy opportunities included mainly drinking and bath cures, which could occur alone or in combination. In the mentioned health resorts different clinical disease symptoms were treated. The most important baths were located in Acquarossa and Stabio, which were specialized in selected therapeutical domains, because of their particular water compositions. Numerous personalities from science and politics were concerned by the local springs and accepted to contribute to the promotion of these structures. Their engagement led to the integration of the native springs in the Farmacopea Ticinese. Since at that time it was extremely difficult to find experienced mineral water analysts in the region, the analyses of local native sources were assigned to qualified experts mainly coming from Italy. This scientific co-operation between the southern part of Switzerland and the northern part of Italy was, already at that time, active also in other work domains. The evaluation of the historical documentation available from the Farmacia Vantussi shows that this pharmacy supplied a considerable assortment of national and foreign spring waters, as well as foreign dried components. Of commercial interest was, to be noted, the free sale of the waters to hospitals, institutions, hotels, restaurants as well as to private households. The sales of waters and of their dried components upon prescription, however, constituted only the minor part. The introduction of the industrial bottling occurring in the first decades of the 20th century, led to a lowering price trend, through which the product 'mineral water' became accessible to a broader public. Henceforth its importance as welfare and medicinal water decreased and the product was considered purely as table water and as a foodstuff. As a consequence this new function brought the sales of mineral waters into the hands of depots and wholesalers, and later on also to retailers, while concomitantly pharmacies turned away from this kind of business. PMID:19230311

  6. Secondary School Advisors as Mentors and Secondary Attachment Figures

    ERIC Educational Resources Information Center

    Van Ryzin, Mark

    2010-01-01

    The teacher-student relationship is vital to student outcomes in secondary school. Unfortunately, the transition from elementary to secondary school is associated with a decrease in the quality or supportiveness of this relationship. In response, some secondary schools implement advisory programs, in which a teacher/advisor meets periodically with

  7. Biomineralization: mineral formation by organisms

    NASA Astrophysics Data System (ADS)

    Addadi, Lia; Weiner, Steve

    2014-09-01

    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.

  8. Mineral-resource data bases

    USGS Publications Warehouse

    U.S. Geological Survey

    1997-01-01

    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

  9. Understanding mineral dusts from the Middle East

    NASA Astrophysics Data System (ADS)

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

    2012-12-01

    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 μm in aerodynamic diameter (PM10), and less than 2.5 μm 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.

  10. Cellular compartmentalization of secondary metabolism

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fungal secondary metabolism is often considered apart from the essential housekeeping functions of the cell. However, there are clear links between fundamental cellular metabolism and the biochemical pathways leading to secondary metabolite synthesis. Besides utilizing key biochemical precursors sh...

  11. Enhanced radionuclide immobilization and flow path modifications by dissolution and secondary precipitates

    SciTech Connect

    Um, Wooyong; Serne, R JEFFREY.; Yabusaki, Steven B.; Owen, Antionette T.

    2005-07-05

    Caustic radioactive wastes that have leaked at Hanford Site (Richland, WA) induce mineral dissolution and subsequent secondary precipitation that influence the fate and transport of contaminants present in the waste solutions. The effects of secondary mineral precipitates, formed after contacting solids with simulated caustic wastes, on the flow path changes and radionuclide immobilization were investigated by reacting quartz, a mixture of quartz and biotite, and a Hanford sediment (Warden soil) with simulated caustic tank waste solution. Continuous Si dissolution and concomitant secondary mineral precipitation were the principal reactions observed in both batch and flow-through tests. Nitrate-cancrinite was the dominant secondary precipitate on mineral surfaces after 3 to 10 d reaction times in batch experiments. X-ray microtomography images of a reacted quartz column revealed that secondary precipitates cemented quartz grains together and modified pore geometry in the center of the column. Along the circumference of the packed column, however, quartz dissolution continuously occurred, suggesting that wastes that leaked from buried tanks in the past likely did not migrate vertically as modeled in risk assessments but rather the pathways likely changed to be dominantly horizontal upon precipitation of secondary precipitate phases in the Hanford vadose zone. Based on batch equilibrium sorption results on the reacted sediments, the dominant secondary precipitates (cancrinites) on the mineral surfaces enhanced the sorption capacity of typical Hanford sediment for radionuclides 129I(-I), 79Se(VI), 99Tc(VII), and 90Sr(II), all of which are of major concern at the Hanford Site.

  12. 1996 annual report on Alaska's mineral resources

    USGS Publications Warehouse

    Schneider, Jill L.

    1997-01-01

    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).

  13. 21 CFR 573.680 - Mineral oil.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ..., FEEDS, AND RELATED PRODUCTS FOOD ADDITIVES PERMITTED IN FEED AND DRINKING WATER OF ANIMALS Food Additive Listing § 573.680 Mineral oil. Mineral oil may be safely used in animal feed, subject to the provisions of... minerals in mineralized salt. (4) To serve as a diluent carrier in the manufacture of feed grade biuret...

  14. 21 CFR 573.680 - Mineral oil.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ..., FEEDS, AND RELATED PRODUCTS FOOD ADDITIVES PERMITTED IN FEED AND DRINKING WATER OF ANIMALS Food Additive Listing § 573.680 Mineral oil. Mineral oil may be safely used in animal feed, subject to the provisions of... minerals in mineralized salt. (4) To serve as a diluent carrier in the manufacture of feed grade biuret...

  15. 21 CFR 573.680 - Mineral oil.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ..., FEEDS, AND RELATED PRODUCTS FOOD ADDITIVES PERMITTED IN FEED AND DRINKING WATER OF ANIMALS Food Additive Listing § 573.680 Mineral oil. Mineral oil may be safely used in animal feed, subject to the provisions of... minerals in mineralized salt. (4) To serve as a diluent carrier in the manufacture of feed grade biuret...

  16. 21 CFR 573.680 - Mineral oil.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ..., FEEDS, AND RELATED PRODUCTS FOOD ADDITIVES PERMITTED IN FEED AND DRINKING WATER OF ANIMALS Food Additive Listing § 573.680 Mineral oil. Mineral oil may be safely used in animal feed, subject to the provisions of... minerals in mineralized salt. (4) To serve as a diluent carrier in the manufacture of feed grade biuret...

  17. 21 CFR 573.680 - Mineral oil.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ..., FEEDS, AND RELATED PRODUCTS FOOD ADDITIVES PERMITTED IN FEED AND DRINKING WATER OF ANIMALS Food Additive Listing § 573.680 Mineral oil. Mineral oil may be safely used in animal feed, subject to the provisions of... minerals in mineralized salt. (4) To serve as a diluent carrier in the manufacture of feed grade biuret...

  18. 43 CFR 3861.3 - Mineral surveyors.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 43 Public Lands: Interior 2 2012-10-01 2012-10-01 false Mineral surveyors. 3861.3 Section 3861.3..., DEPARTMENT OF THE INTERIOR MINERALS MANAGEMENT (3000) MINERAL PATENT APPLICATIONS Surveys and Plats 3861.3 Mineral surveyors....

  19. 43 CFR 3830.10 - Locatable minerals.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 43 Public Lands: Interior 2 2013-10-01 2013-10-01 false Locatable minerals. 3830.10 Section 3830..., DEPARTMENT OF THE INTERIOR MINERALS MANAGEMENT (3000) LOCATING, RECORDING, AND MAINTAINING MINING CLAIMS OR SITES; GENERAL PROVISIONS Mining Law Minerals 3830.10 Locatable minerals....

  20. 43 CFR 3861.3 - Mineral surveyors.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 43 Public Lands: Interior 2 2013-10-01 2013-10-01 false Mineral surveyors. 3861.3 Section 3861.3..., DEPARTMENT OF THE INTERIOR MINERALS MANAGEMENT (3000) MINERAL PATENT APPLICATIONS Surveys and Plats 3861.3 Mineral surveyors....

  1. 43 CFR 3861.3 - Mineral surveyors.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 43 Public Lands: Interior 2 2014-10-01 2014-10-01 false Mineral surveyors. 3861.3 Section 3861.3..., DEPARTMENT OF THE INTERIOR MINERALS MANAGEMENT (3000) MINERAL PATENT APPLICATIONS Surveys and Plats 3861.3 Mineral surveyors....

  2. 43 CFR 3830.10 - Locatable minerals.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 43 Public Lands: Interior 2 2012-10-01 2012-10-01 false Locatable minerals. 3830.10 Section 3830..., DEPARTMENT OF THE INTERIOR MINERALS MANAGEMENT (3000) LOCATING, RECORDING, AND MAINTAINING MINING CLAIMS OR SITES; GENERAL PROVISIONS Mining Law Minerals 3830.10 Locatable minerals....

  3. 43 CFR 3830.10 - Locatable minerals.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 43 Public Lands: Interior 2 2014-10-01 2014-10-01 false Locatable minerals. 3830.10 Section 3830..., DEPARTMENT OF THE INTERIOR MINERALS MANAGEMENT (3000) LOCATING, RECORDING, AND MAINTAINING MINING CLAIMS OR SITES; GENERAL PROVISIONS Mining Law Minerals 3830.10 Locatable minerals....

  4. 43 CFR 3861.3 - Mineral surveyors.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 43 Public Lands: Interior 2 2011-10-01 2011-10-01 false Mineral surveyors. 3861.3 Section 3861.3..., DEPARTMENT OF THE INTERIOR MINERALS MANAGEMENT (3000) MINERAL PATENT APPLICATIONS Surveys and Plats 3861.3 Mineral surveyors....

  5. 43 CFR 3830.10 - Locatable minerals.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 43 Public Lands: Interior 2 2011-10-01 2011-10-01 false Locatable minerals. 3830.10 Section 3830..., DEPARTMENT OF THE INTERIOR MINERALS MANAGEMENT (3000) LOCATING, RECORDING, AND MAINTAINING MINING CLAIMS OR SITES; GENERAL PROVISIONS Mining Law Minerals 3830.10 Locatable minerals....

  6. 43 CFR 8.5 - Mineral rights.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 43 Public Lands: Interior 1 2011-10-01 2011-10-01 false Mineral rights. 8.5 Section 8.5 Public... INTERIOR AND OF THE ARMY RELATIVE TO RESERVOIR PROJECT LANDS 8.5 Mineral rights. Mineral, oil and gas..., but mineral rights not acquired will be subordinated to the Government's right to regulate...

  7. 43 CFR 8.5 - Mineral rights.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 43 Public Lands: Interior 1 2010-10-01 2010-10-01 false Mineral rights. 8.5 Section 8.5 Public... INTERIOR AND OF THE ARMY RELATIVE TO RESERVOIR PROJECT LANDS 8.5 Mineral rights. Mineral, oil and gas..., but mineral rights not acquired will be subordinated to the Government's right to regulate...

  8. Formation and Reactivity of Biogenic Iron Minerals

    SciTech Connect

    Ferris, F. Grant

    2002-06-01

    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.

  9. Thermodynamics of Minerals and Melts

    NASA Astrophysics Data System (ADS)

    Rumble, Douglas

    The book, Thermodynamics of Minerals and Melts, edited by R. C. Newton, A. Navrotsky, and B . J . Wood, is volume 1 in the series Advances in Physical Geochemistry, with S. K. Saxena as series editor. The volume is divided into three parts: (1) general principles, (2) thermodynamic analysis of mineral systems, and (3) thermodynamics of melt systems. Part 1 had one paper on the derivation of J. Willard Gibbs' mathematical formulation of the combined first and second laws of thermodynamics for an open system by G. Tunell. Part 2 covers the following topics, listed with authors: thermodynamics of devolatilization reactions (T. J. B. Holland), ‘lambda’ transitions in minerals (A. B. Thompson and E. H. Perkins), crystal-field effects on thermodynamic properties of iron-bearing minerals (B.J. Wood), stable isotope geothermometry (R. N. Clayton), calculation of thermodynamic properties of minerals from natural parageneses (L. L. Perchuk, K. K. Podlesskii, and L. Y. Aranovich), thermodynamics of the garnet-plagioclase-Al2O3-quartz geobarometer (R. C. Newton and H. T. Haselton), and thermodynamics of diopside and enstatite solid solutions (D. H. Lindsley, T. E. Grover, and P. M. Davidson).

  10. Mineral Abundances in Martian Soils

    NASA Astrophysics Data System (ADS)

    Martel, L. M. V.

    2011-01-01

    Using traditional geochemical calculations with in situ Martian cosmochemical data researchers Harry (Hap) McSween Jr. and Ian McGlynn (University of Tennessee) and Deanne Rogers (SUNY at Stony Brook) have developed a method for identifying the major and minor minerals in soils at the Mars Exploration Rovers (MER) landing sites. The team used information from the MER Athena instrument package operating on Mars since January, 2004. They created two models using MiniTES spectra, Alpha Particle X-ray Spectrometer (APXS) data, and Mossbauer spectrometer data to calculate the mineralogy of average dark soils on the Gusev crater plains and on Meridiani Planum, located on opposite sides of Mars. Soils at both locations are similarly composed of minerals derived from the comminution of basalts (about three quarters by weight) and other minerals derived from rocks altered by chemical weathering (about one quarter by weight). This mixture of possibly unrelated materials (primary and altered) might mean that the alteration of soil did not occur in place and that the basaltic and alteration suites of minerals came from different sources. The nearly identical modal mineralogy at two widely-separated locations on the planet supports a previous hypothesis based on comparable chemical compositions that soils have been homogenized, if not globally then at least over large areas of the Martian surface. Yet, global maps of orbital remote sensing data have not shown surface abundances of alteration minerals as high as those in the Martian soils.

  11. Traditional Methods for Mineral Analysis

    NASA Astrophysics Data System (ADS)

    Ward, Robert E.; Carpenter, Charles E.

    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).

  12. CRYSTAL CHEMISTRY OF HYDROUS MINERALS

    SciTech Connect

    Y. ZHAO; ET AL

    2001-02-01

    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.

  13. Rock Magnetic Mineral Assemblage in Mineral Separates from Xenoliths of Continental Lithospheric Mantle

    NASA Astrophysics Data System (ADS)

    Khakhalova, E.; Feinberg, J. M.; Ionov, D. A.; Ferre, E. C.; Friedman, S. A.; Hernandez, F. M.; Neal, C. R.; Conder, J. A.

    2014-12-01

    Studies of aeromagnetic anomalies suggest that the lithospheric mantle may contribute to long wavelength features. Examination of unaltered mantle xenoliths may reveal the mineralogical sources of these aeromagnetic anomalies. Prior work has reported microscopic inclusions of magnetic minerals in mantle silicates. Here we explore the magnetism of pure olivine, clinopyroxene, orthopyroxene, and spinel separated from peridotite xenoliths from the Dariganga and Tariat localities in Mongolia that sample the lithospheric mantle. All separates were leached with HF and HCl to remove secondary minerals adhering to the surface of the grains or in cracks. Separates were then mounted in cement to create monomineralic specimens for investigation using hysteresis loops, first order reversal curves (FORC), alternating field and thermal demagnetization of a 1T IRM, and low-temperature magnetometry. All specimens showed trace concentrations of ferromagnetic inclusions with Ms values of ~10-3 Am2kg-1. Thermal demagnetization showed a range of unblocking temperatures with median destructive temperatures of 300-400C. Two specimens showed a dramatic demagnetization at 585C, consistent with pure magnetite (Mt). The presence of Mt was confirmed by observations of the Verwey transition at 100-120K and by backfield remanence acquisition curves that plateau at ~300 mT. The median destructive alternating field was ~20 mT and 40-80 mT for specimens from Dariganga and Tariat, respectively. FORC diagrams show single-domain-like behavior with a median Hc of ~20 mT. The demagnetization experiments suggest that Mt inclusions in the lattice of olivine, opx, cpx and spinel carry magnetic remanence. Thus, the lithospheric mantle may exhibit in-situ ferromagnetism carried by Mt below 585C. The magnetization of separates varies between xenolith localities but is consistent amongst minerals of the same locality. Future work will address whether the Mt formed before or during xenolith ascent.

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

    PubMed Central

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

    2012-01-01

    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

  15. Nonaqueous secondary batteries

    NASA Astrophysics Data System (ADS)

    Yamahira, Takayuki; Anzai, Masanori

    1991-04-01

    The object of the present invention is to make possible the repeated use for a long period of time of nonaqueous secondary battery that contains in the battery case a negative electrode of a carbonized organic substance, a positive electrode with Li(x)MO2 (where M is at least one of Co and Ni; x being 0.05 less than or = x less than or = 1.10) and an electrolytic solution. The method comprises at least one charging operation of the battery before the sealing of their cells to inhibit the gas generation that would occur in the finished battery in its charging and discharging.

  16. Geochemical processes at mineral surfaces

    SciTech Connect

    Davis, J.A.; Hayes, K.F.

    1986-01-01

    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.

  17. Geochemistry and Minerality of Wine

    NASA Astrophysics Data System (ADS)

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

    2010-12-01

    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.

  18. Alteration minerals in impact-generated hydrothermal systems - Exploring host rock variability

    NASA Astrophysics Data System (ADS)

    Schwenzer, Susanne P.; Kring, David A.

    2013-09-01

    Impact-generated hydrothermal systems have been previously linked to the alteration of Mars crust and the production of secondary mineral assemblages seen from orbit. The sensitivity of the resultant assemblages has not yet been evaluated as a function of precursor primary rock compositions. In this work, we use thermochemical modeling to explore the variety of minerals that could be produced by altering several known lithologies based on martian meteorite compositions. For a basaltic host rock lithology (Dhofar 378, Humphrey) the main alteration phases are feldspar, zeolite, pyroxene, chlorite, clay (nontronite, kaolinite), and hematite; for a lherzolithic host rock lithology (LEW 88516) the main alteration phases are amphibole, serpentine, chlorite, clay (nontronite, kaolinite), and hematite; and for an ultramafic host rock lithology (Chassigny) the main minerals are secondary olivine, serpentine, magnetite, quartz, and hematite. These assemblages and proportions of phases in each of those cases depend on W/R and temperature. Integrating geologic, hydrologic and alteration mineral evidence, we have developed a model to illustrate the distribution of alteration assemblages that occur in different levels of an impact structure. At the surface, hot, hydrous alteration affects the ejecta and melt sheet producing clay and chlorite. Deeper in the subsurface and depending on the permeability of the rock, a variety of minerals - smectite, chlorite, serpentine, amphiboles and hematite - are produced in a circulating hydrothermal system. These modeled mineral distributions should assist with interpretation of orbital observations and help guide surface exploration by rovers and sample return assets.

  19. Handbook of Marine Mineral Deposits

    NASA Astrophysics Data System (ADS)

    Moore, George W.

    Handbook of Marine Mineral Deposits delves into marine mineral exploration and mining, covering both the fields economics and the state of the art of its science. The 1982 Law of the Sea Convention had a chilling effect on the deep-sea mining industry Later in the 1980s, most nations adopted the 370-km exclusive economic zone, which rekindled interest in the industry. Amendments made to the law in 1994 have also improved the outlook since then. India has agreed to abide by the Law of the Sea Convention by setting aside reserves of manganese nodules in the Central Indian Basin for international use that equal those it has claimed for itself.

  20. Thermodynamics of minerals and melts

    NASA Astrophysics Data System (ADS)

    Ghiorso, Mark S.

    The thermochemical properties of earth materials and models of fundamental geodetic processes are discussed, along with the energetics of mineral-melt systems and microscopic-level processes contributing to thermodynamic quantities, in a critical review of U.S. research from the period 1987-1990. Consideration is given to compilations of thermodynamic data; computational methods; links between thermodynamics and kinetics; thermometry, bathymetry, and the estimation of intensive variables; mineral basic data, phase transitions, and solid solutions; and melt and fluid modeling, macroscopic properties, and spectroscopy. A comprehensive bibliography is provided.

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

    USGS Publications Warehouse

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

    2011-01-01

    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.

  2. The scaling of secondary craters

    NASA Technical Reports Server (NTRS)

    Croft, Steven K.

    1991-01-01

    Secondary craters are common features around fresh planetary-scale primary impact craters throughout most of the Solar System. They derive from the ejection phase of crater formation, thus secondary scaling relations provide constraints on parameters affecting ejection processes. Secondary crater fields typically begin at the edge of the continuous ejecta blankets (CEB) and extend out several crater radii. Secondaries tend to have rounded rims and bilateral symmetry about an axis through the primary crater's center. Prominent secondary chains can extend inward across the CEB close to the rim. A simple method for comparing secondary crater fields was employed: averaging the diameters and ranges from the center of the primary crater of the five largest craters in a secondary crater field. While not as much information is obtained about individual crater fields by this method as in more complete secondary field mapping, it facilitates rapid comparison of many secondary fields. Also, by quantifying a few specific aspects of the secondary crater field, this method can be used to construct scaling relations for secondary craters.

  3. Secondary circulation system

    SciTech Connect

    Laing, K.; Laing, D.; Laing, B.

    1987-07-28

    This patent describes a circulation system for secondary circulation in a domestic hot water system composed of a distribution pipe, a circulation pipe for secondary circulation, and a pump with a pumphousing having the two openings for inlet and outlet of water. Together they form a loop. Both ends of the loop communicate with the heat source, e.g. a tank characterized in that the circulation pipe, having an inner diameter of about 1/4 inch, is situated within the distribution pipe; the first end of the circulation pipe communicates with the pump; the second end of the circulation pipe communicates with the hot region of the heat source (e.g. the upper level of a tank); between the first end of the circulation pipe and one opening of the pumphousing a valve is arranged; the other opening of the pump housing communicates with the interior of the heatsource via a tube; between the tube and the other opening of the pump housing a valve is arranged; one of the two valves is a checkvalve, preventing backflow through the pump housing caused by pressure difference between the second end of the circulation pipe and the distribution pipe.

  4. Secondary aortoduodenal fistula

    PubMed Central

    Geraci, Girolamo; Pisello, Franco; Volsi, Francesco Li; Facella, Tiziana; Platia, Lina; Modica, Giuseppe; Scium, Carmelo

    2008-01-01

    Aorto-duodenal fistulae (ADF) are the most frequent aorto-enteric fistulae (80%), presenting with upper gastrointestinal bleeding. We report the first case of a man with a secondary aorto-duodenal fistula presenting with a history of persistent occlusive syndrome. A 59-year old man who underwent an aortic-bi-femoral bypass 5 years ago, presented with dyspepsia and biliary vomiting. Computed tomography scan showed in the third duodenal segment the presence of inflammatory tissue with air bubbles between the duodenum and prosthesis, adherent to the duodenum. The patient was submitted to surgery, during which the prosthesis was detached from the duodenum, the intestine failed to close and a gastrojejunal anastomosis was performed. The post-operative course was simple, secondary ADF was a complication (0.3%-2%) of aortic surgery. Mechanical erosion of the prosthetic material into the bowel was due to the lack of interposed retroperitoneal tissue or the excessive pulsation of redundantly placed grafts or septic procedures. The third or fourth duodenal segment was most frequently involved. Diagnosis of ADF was difficult. Surgical treatment is always recommended by explorative laparotomy. ADF must be suspected whenever a patient with aortic prosthesis has digestive bleeding or unexplained obstructive syndrome. Rarely the clinical picture of ADF is subtle presenting as an obstructive syndrome and in these cases the principal goal is to effectively relieve the mechanical bowel obstruction. PMID:18200675

  5. Rapid Ascent of Aphyric Mantle Melts through the Overriding Crust in Subduction Zones: Evidence from Variable Uranium-Series Disequilibria, Amorphous Hydrous Alteration Microtextures in Crystal Rims, and Two-Pyroxene Pseudo-Decompression Paths

    NASA Astrophysics Data System (ADS)

    Zellmer, G. F.; Freymuth, H.; Hsieh, H. H.; Hwang, S. L.; Iizuka, Y.; Miller, C. A.; Rubin, K. H.; Sakamoto, N.; Yurimoto, H.

    2014-12-01

    Volcanic hazard mitigation at subduction zones critically depends on knowledge of magma generation and ascent processes and timescales. Two diametrically opposite scenarios are presently debated: One paradigm is the generation of low-silica (basaltic) melts in the mantle wedge, followed by protracted sub-liquidus magma ascent and evolution through crystal growth and fractionation in crustal reservoirs, which are tapped during volcanic eruptions. In contrast, a diametrically opposite model favours the generation of higher silica melts in the mantle or in a lower crustal hot zone, followed by rapid decompression to the surface under super-liquidus conditions. In the latter case, crystals are picked up during magma ascent, and are in the process of dissolving. We present multiple lines of evidence that point to crystal uptake as the principal processes by which arc melts acquire their crystal cargo: (i) variable 234U-238U disequilibria in mineral separates; (ii) hydrous mineral rims with amorphous alteration textures; and (iii) two-pyroxene pseudo-decompression paths; cf. Zellmer et al. (2014a,b,c), doi: 10.1144/SP385.3 and 10.1144/SP385.9 and 10.1144/SP410.1. These observations point to a scarcity of true phenocrysts in many arc magmas, and thus to decompression of aphyric melts that take up their crystal cargo during ascent. The data imply that many hydrous wedge melts are more silica-rich than basalts and achieve super-liquidus conditions during rapid ascent from great depth.

  6. Physical controls on matrix mineralization

    NASA Astrophysics Data System (ADS)

    Tao, Jinhui; Nielsen, Mike; de Yoreo, Jim

    2013-03-01

    During biomineral formation, protein matrices impose order on nucleating mineral phases. While many studies have examined the structural relationships between mineral and matrix, few have explored the energetics. To address this gap we use in situ TEM and AFM to investigate calcium phosphate nucleation and growth in collagen and amelogenin matrices. In situ TEM results indicate that, in the absence of calcium, amelogenin nanospheres are loose aggregates of oligomers, while in the presence of calcium phosphate solution, can form chain-like structures and become mineralized with an amorphous phase before the appearance of crystalline phases. Results on collagen reveal the evolution of nucleation pathways from direct to indirect with increasing supersaturation and analysis of nucleation rates using classical theory demonstrates a reduction in interfacial energy due to matrix-mineral interactions. However, the calculated thermodynamic barriers are in contradiction to the observed pathways and well in excess of sensible values. We present a model based on cluster aggregation within the classical context that reconciles experiment and theory. Authors would like to acknowledge grant no. DK61673 from the National Institutes of Health. Theoretical analysis was supported by Office of Science, Office of Basic Energy Sciences of the U.S. Department of Energy under Contract no. DE-AC02-05CH1123.

  7. Dietary fatty acids and minerals

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Accumulating evidence in animals and humans shows that dietary fatty acids influence the absorption and utilization of certain mineral elements. Fat intake exceeding 10% of energy intake reduces calcium uptake and use by the body, and this effect is more pronounced with saturated compared to unsatu...

  8. 77 FR 56273 - Conflict Minerals

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-12

    ..., Release No. 34-63547 (Dec. 15, 2010) [75 FR 80948] (the ``Proposing Release''). \\5\\ Public Law 111-203... (Jan. 7, 2011) (``WGC I''). \\33\\ Conflict Minerals, Release No. 34-63793 (Jan. 28, 2011) [76 FR 6110... Public Comments C. Small Entities Subject to the Final Rule D. Reporting, Recordkeeping, and...

  9. Mysterious Lava Mineral on Mars

    NASA Technical Reports Server (NTRS)

    2004-01-01

    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.'

  10. Mineral of the month: titanium

    USGS Publications Warehouse

    Gambogi, Joseph

    2004-01-01

    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.

  11. Mineral evolution and Earth history

    USGS Publications Warehouse

    Bradley, Dwight C.

    2015-01-01

    The field of mineral evolutiona merger of mineralogy and Earth historycoalesced in 2008 with the first of several global syntheses by Robert Hazen and coworkers in theAmerican Mineralogist.They showed that the cumulative abundance of mineral species has a stepwise trend with first appearances tied to various transitions in Earth history such as the end of planetary accretion at ca. 4.55 Ga and the onset of bio-mediated mineralogy at ca. >2.5 Ga. A global age distribution is best established for zircon. Observed abundance of zircon fluctuates through more than an order of magnitude during successive supercontinent cycles. The pulse of the Earth is also recorded, albeit imperfectly, by the87Sr/86Sr composition of marine biogenic calcite; the Sr-isotopic ratio of this mineral reflects the balance of inputs of primitive strontium at mid-ocean ridges and evolved strontium that drains off the continents. A global mineral evolution database, currently in the works, will greatly facilitate the compilation and analysis of extant data and the expansion of research in mineralogy outside its traditional bounds and into more interdisciplinary realms.

  12. Detrital Mineral Grains in Tektites.

    PubMed

    Bairnes, V E

    1963-12-27

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

  13. Mineral of the month: indium

    USGS Publications Warehouse

    George, Micheal W.

    2004-01-01

    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.

  14. Mineral of the month: rhenium

    USGS Publications Warehouse

    Magyar, Michael J.

    2005-01-01

    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.

  15. Mineral of the month: aggregates

    USGS Publications Warehouse

    Tepordei, Valentin V.

    2005-01-01

    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.

  16. Mineral of the month: boron

    USGS Publications Warehouse

    Lyday, Phyllis A.

    2005-01-01

    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.

  17. Copper isotopes as monitors of redox processes in hydrothermal mineralization

    NASA Astrophysics Data System (ADS)

    Markl, Gregor; Lahaye, Yann; Schwinn, Gregor

    2006-08-01

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

  18. Elastic Properties of Mantle Minerals

    NASA Astrophysics Data System (ADS)

    Duffy, T. S.; Stan, C. V.

    2012-12-01

    The most direct information about the interior structure of the Earth comes from seismic wave velocities. Interpretation of seismic data requires an understanding of how sound velocities and elastic properties of minerals vary with pressure, temperature, crystal structure, and composition as well as the role of anelasticity, melts, etc. More generally, elastic moduli are important for understanding many solid-state phenomena including mechanical stability, interatomic interactions, material strength, compressibility, and phase transition mechanisms. The database of mineral elasticity measurements has been growing rapidly in recent years. In this work, we report initial results of an ongoing survey of our current knowledge of mineral elasticity at both ambient conditions and high pressures and temperatures. The analysis is selective, emphasizing single crystal measurements but also incorporating polycrystalline measurements and volume compression data as appropriate. The goal is to synthesize our current understanding of mineral elasticity in terms of structure and composition, and to identify the major remaining needs for experimental and theoretical work. Clinopyroxenes (Cpx) provide an example of our approach. A wide range of clinopyroxene compositions are found geologically and Mg-, Ca-, and Na-rich clinopyroxenes are expected to be important components in the upper mantle. The single-crystal elastic properties of a number of endmember Cpx compositions have been measured and these exhibit a range of ~25% in shear velocity. Those with monovalent cations (spodumene, jadeite) in the M2 site exhibit the highest velocities while Fe-rich (hendenbergit, acmite) compositions have the lowest velocities. The effects on velocity due to a wide range of chemical substitutions can be defined, but there are important discrepancies and omissions in the database. New measurements of omphacites, intermediate diopside-hedenbergite compositions, aegerine/acmite, augite, etc. are clearly needed. We also show how the combination of single-crystal elasticity data and volume compression data for diopside can be used to constrain the pressure derivative of the bulk modulus -- an important parameter for modeling seismic velocities in mantle assemblages. More broadly, the mineral elasticity data set can provide insights into the systematic variation of elastic properties that are of great importance in mineral physics and geophysics. We will examine the role of anisotropy, Vp/Vs variations, pressure derivatives of elastic moduli, and auxetic behavior to name a few properties of interest. The pioneering work on mineral elasticity carried out by Bob Liebermann has made an immense contribution to this important database, as well as providing strong scientific motivation for this work.

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

    PubMed Central

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

    2009-01-01

    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

  20. Plants and microorganisms as drivers of mineral weathering

    NASA Astrophysics Data System (ADS)

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

    2011-12-01

    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.

  1. Gender differences in fracture risk and bone mineral density.

    PubMed

    Kudlacek, S; Schneider, B; Resch, H; Freudenthaler, O; Willvonseder, R

    2000-10-31

    We have investigated gender-related differences of bone mineral density and fracture threshold in 136 males (age, 60.7+/-9.3 years) and 337 females (age, 59.7+/-7.8 years) without evidence of secondary osteoporosis. Women and men were examined for total amount of spine fractures and bone mineral density by quantitative computed tomography (QCT) of three non-fractured vertebral bodies L1-L5. Females with lumbar fractures (n=96) when compared with non-fracture women (n=241) were older and had lower bone density at their vertebral sites. Males with vertebral fractures (n=52) were older and had a significantly reduced bone mineral density of the spine when compared with healthy males (n=84). When we compared gender-related vertebral fracture rates, we observed a significantly higher prevalence of vertebral fractures in the male population. After matching males and females for age and bone mineral density to exclude an influence of either variable, we compared the prevalence of vertebral fracture risk in both sexes with logistic regression analysis. Data of estimated fracture risk, differed very significantly for sex and bone density at the vertebral site, indicating that men present fracture at a higher bone density level compared with females; in 10% of study population fractures occurred at a QCT level of 105 mg/cm(3) in women and 120 mg/cm(3) in men. The estimated odds ratio for sex of 3.1 (95% CI) means a three-fold increased risk for vertebral fractures compared to males at a given density level. These results underline that a decreased bone mineral density leads to the occurrence of spine fractures in females and males as well. PMID:11063899

  2. Management of secondary peritonitis.

    PubMed Central

    Wittmann, D H; Schein, M; Condon, R E

    1996-01-01

    OBJECTIVE. The authors review current definition, classification, scoring, microbiology, inflammatory response, and goals of management of secondary peritonitis. SUMMARY BACKGROUND DATA. Despite improved diagnostic modalities, potent antibiotics, modern intensive care, and aggressive surgical treatment, up to one third of patients still die of severe secondary peritonitis. Against the background of current understanding of the local and systemic inflammatory response associated with peritonitis, there is growing controversy concerning the optimal antibiotic and operative therapy, intensified by lack of properly conducted randomized studies. In this overview the authors attempt to outline controversies, suggest a practical clinical approach, and highlight issues necessitating further research. METHODS. The authors review the literature and report their experience. RESULTS. The emerging concepts concerning antibiotic treatment suggest that less-in terms of the number of drugs and the duration of treatment-is better. The classical single operation for peritonitis, which obliterates the source of infection and purges the peritoneal cavity, may be inadequate for severe forms of peritonitis; for the latter, more aggressive surgical techniques are necessary to decompress increased intra-abdominal pressure and prevent or treat persistent and recurrent infection. The widespread acceptance of the more aggressive and demanding surgical methods has been hampered by the lack of randomized trials and reportedly high associated morbidity rates. CONCLUSIONS. Sepsis represents the host's systemic inflammatory response to bacterial peritonitis. To improve results, both the initiator and the biologic consequences of the peritoneal infective-inflammatory process should be addressed. The initiator may be better controlled in severe forms of peritonitis by aggressive surgical methods, whereas the search for methods to abort its systemic consequences is continuing. PMID:8678610

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

    NASA Astrophysics Data System (ADS)

    Lybrand, R. A.; Rasmussen, C.

    2011-12-01

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

  4. 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)

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

    2014-08-01

    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.

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

    NASA Astrophysics Data System (ADS)

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

    2014-05-01

    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.

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

    NASA Astrophysics Data System (ADS)

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

    2014-09-01

    Previous 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.

  7. Secondary air control damper arrangement

    SciTech Connect

    Chadshay, R.

    1984-01-17

    The outline of a tangentially-fired furnace combustion chamber is arranged to show a representative windbox in one corner of the furnace. The secondary air is disclosed as supplied through one set of vertically tiltable nozzles mounted in the windbox. The secondary air supply conduit is mounted to feed the tiltable nozzles. The secondary air supply conduit section adjacent to the nozzles has straightening vanes forming channels in which independently controlled louvers regulate the total cross-sectional area of the channels to maintain the desired velocity of the secondary air through the nozzles.

  8. HYPERCALCEMIA AND METASTATIC MINERALIZATION INVOLVING FOOTPADS IN ROCK HYRAXES (PROCAVIA CAPENSIS).

    PubMed

    Johnson, James G; Chinnadurai, Sathya K; Landolfi, Jennifer A; Langan, Jennifer N

    2015-09-01

    Three rock hyraxes (Procavia capensis) maintained in a zoological collection had chronic hypercalcemia and azotemia. In addition, all animals displayed signs of lameness due to footpad lesions that were histologically characterized as marked metastatic mineralization with granulomatous inflammation, reminiscent of calcinosis circumscripta. Although the animals were managed with aggressive fluid therapy, calciuresis, and dietary modification, all were eventually humanely euthanized due to the severity of their footpad lesions and/or progression of renal disease. Metastatic mineralization was also noted in other soft tissues among the three cases, including the stomach, colon, lung, vascular wall, ovary, and kidney. Varying degrees of interstitial nephritis were confirmed on postmortem examination, and in the absence of other causes for hypercalcemia, metastatic mineralization was presumably the consequence renal dysfunction. The renal pathway is the primary mode of calcium excretion in the rock hyrax. In renal dysfunction, hypercalcemia may develop secondary to decreased calcium excretion. Footpad mineralization is an uncommon sequel to renal dysfunction in domestic animals but has not been reported in rock hyraxes. A retrospective review of mortality data in this collection revealed a notable prevalence of renal lesions, including two additional animals with metastatic mineralization and renal dysfunction. Expanding knowledge of renal diseases will further guide preventative and clinical measures, including screening for metastatic mineralization and therapeutic trials for management of hypercalcemia and calcium mineral deposition in the footpads and other soft tissues. PMID:26352962

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

    NASA Astrophysics Data System (ADS)

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

    2013-11-01

    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.

  10. Mineral Resources, Geological Structure and Landform Surveys

    NASA Technical Reports Server (NTRS)

    Short, M. N.

    1973-01-01

    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.

  11. Vitamin and Mineral Supplement Fact Sheets

    MedlinePLUS

    ... DRI Tool Daily Value (DV) Tables Vitamin and Mineral Supplement Fact Sheets A - E | F - L | M - S | ... Information Botanical Dietary Supplements: Background Information Vitamin and Mineral Fact Sheets Botanical Supplement Fact Sheets Frequently Asked ...

  12. Mineral Resources, Economic Growth, and World Population

    ERIC Educational Resources Information Center

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

    1974-01-01

    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)

  13. Mohr on the minerals bill

    NASA Astrophysics Data System (ADS)

    Mohr, Paul

    Your item on NMSA (National Minerals Security Act) [Eos, May 19, p. 497] makes depressing reading. According to Mr. Santini: the hands of a few foreign nations [hold those minerals without which] we cannot build jet aircraft, weapons, or other military hardware vitally important to our national security. The implication in the superfluous adjective foreign is tangible. Those non-American nations are set up as being a threat; but a threat to what? To a security in which there are several dubious ingredients, not least the means whereby what now needs guarding was itself secured? And, one can ask, to what extent does security form a solid-solution series with material aggrandizement when studied objectively?

  14. Minerals yearbook, 1991: Massachusetts. Annual report

    SciTech Connect

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

    1993-05-01

    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.

  15. Mine and mineral occurrences of Afghanistan

    USGS Publications Warehouse

    Orris, G.J.; Bliss, J.D.

    2002-01-01

    This inventory of more than 1000 mines and mineral occurrences in Afghanistan was compiled from published literature and the files of project members of the National Industrial Minerals project of the U.S. Geological Survey. The compiled data have been edited for consistency and most duplicates have been deleted. The data cover metals, industrial minerals, coal, and peat. Listings in the table represent several levels of information, including mines, mineral showings, deposits, and pegmatite fields.

  16. Bone mineral in Vilcabamba, Ecuador.

    PubMed

    Mazess, R B

    1978-04-01

    Bone mineral content was measured by photon absorptiometry of the radius in an Ecuadorian population noted for longevity and for rarity of fractures and spinal curvature in the elderly. Bone mass, after covariance adjustment for age, height, weight, and bone width, was 15% below values for U.S. whites, indicating that the rarity of skeletal problems was not due to high bone mass or diminution of aging bone loss. PMID:416676

  17. The MINER?A detector

    NASA Astrophysics Data System (ADS)

    Fiorentini, G. A.

    2015-05-01

    MINER?A (Main INjector Experiment for ?-A) is a dedicated neutrino-nucleus scattering experiment at Fermilab. It uses a fine-grained fully active detector to make precision measurements of neutrino and antineutrino interactions on a variety of different nuclear targets (plastic scintillator, C, Fe, Pb, He and H2O) for energies up to few GeV. An overview of the experiment and a description of the detector are presented.

  18. Evaporites, petroleum and mineral resources

    SciTech Connect

    Melvin, J.L.

    1991-01-01

    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.

  19. 75 FR 80947 - Conflict Minerals

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-23

    ...We are proposing changes to the annual reporting requirements of issuers that file reports pursuant to Sections 13(a) or 15(d) of the Securities Exchange Act of 1934 to implement Section 1502 of the Dodd- Frank Wall Street Reform and Consumer Protection Act. The proposed rules would require any issuer for which conflict minerals are necessary to the functionality or production of a product......

  20. Mineral of the month: garnet

    USGS Publications Warehouse

    Olson, Donald

    2005-01-01

    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.

  1. Minerals

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Over the past two decades, the aquaculture industry has expanded rapidly throughout the world and is expected to continue to grow in the years to come due to the high cost of harvesting fish from the oceans, the un-sustainability of ocean fishing methods, and the increased demand for fish as a resul...

  2. Is Struvite a Prebiotic Mineral?

    PubMed Central

    Gull, Maheen; Pasek, Matthew A.

    2013-01-01

    The prebiotic relevance of mineral struvite, MgNH4PO46H2O, 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 78 days and showed up to 28% phosphorylation of glycerol. In contrast, the compositional requirements for the precipitation of struvite are high ammonium and phosphate concentrations, as well as a little Ca2+ dissolved in the water. Combined, these requirements suggest that it is not likely that struvite was present in excess on the early Earth to carry out phosphorylation reactions. The present study focuses on the thermodynamic aspects of struvite formation, complementing the results given by Orgel and Handschuh (1973), which were based on the kinetic effects. PMID:25369744

  3. 76 FR 44892 - Information Collection; Locatable Minerals

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-27

    ... should be addressed to: USDA, Forest Service, Minerals and Geology Management Staff, Mail Stop 1126, 1601... Forest Service, Minerals and Geology Management Staff, 1601 N. Kent St., 5th Floor, Arlington, Virginia... entry to the building. FOR FURTHER INFORMATION CONTACT: Tony Ferguson, Director, Minerals and...

  4. 43 CFR 8.5 - Mineral rights.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 43 Public Lands: Interior 1 2014-10-01 2014-10-01 false Mineral rights. 8.5 Section 8.5 Public... INTERIOR AND OF THE ARMY RELATIVE TO RESERVOIR PROJECT LANDS 8.5 Mineral rights. Mineral, oil and gas rights will not be acquired except where the development thereof would interfere with project...

  5. 43 CFR 8.5 - Mineral rights.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 43 Public Lands: Interior 1 2012-10-01 2011-10-01 true Mineral rights. 8.5 Section 8.5 Public... INTERIOR AND OF THE ARMY RELATIVE TO RESERVOIR PROJECT LANDS 8.5 Mineral rights. Mineral, oil and gas rights will not be acquired except where the development thereof would interfere with project...

  6. 43 CFR 8.5 - Mineral rights.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 43 Public Lands: Interior 1 2013-10-01 2013-10-01 false Mineral rights. 8.5 Section 8.5 Public... INTERIOR AND OF THE ARMY RELATIVE TO RESERVOIR PROJECT LANDS 8.5 Mineral rights. Mineral, oil and gas rights will not be acquired except where the development thereof would interfere with project...

  7. Mineral matter identification of some Turkish lignites

    SciTech Connect

    Yaman, S.; Taptik, Y.; Kuecuekbayrak, S.; Kadioglu, E.

    1995-01-01

    Samples of 15 Turkish lignites were oxidized by performic acid. Their mineral matter was isolated without any important chemical decomposition. The X-ray diffraction method was employed to determine the mineral species in the isolated mineral matter and in the ashes of the lignite samples. The results were compared and discussed.

  8. Minerals yearbook, 1991: North Dakota. Annual report

    SciTech Connect

    Peterson, E.K.; Biek, R.F.

    1993-05-01

    The value of North Dakota's nonfuel mineral industry in 1991 was about $17 million, a decrease of 35% from that of 1990. The State ranked 48th nationally in nonfuel mineral production, accounting for less than 1% of the Nation's total mineral value for the year. The report presents tables and data on the industry.

  9. Minerals yearbook vol. III : area reports international

    USGS Publications Warehouse

    U.S. Geological Survey

    0000-01-01

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

  10. MARINE MINERAL RESOURCES - AN UPDATE AND INTRODUCTION.

    USGS Publications Warehouse

    Cruickshank, Michael J.; Siapno, William

    1985-01-01

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

  11. Mssbauer study of Chinese ancient mineral drugs

    NASA Astrophysics Data System (ADS)

    Qin, Guangyong; Li, Shi

    1992-04-01

    About 100 crude Chinese mineral drug samples were investigated with Mossbauer spectroscopy, X-ray diffraction analysis and atomic absorption spectroscopy. The classifications, species and components of Chinese mineral drugs will be elucidated. The pharmaceutic and curative mechanisms of these mineral drugs will be discussed.

  12. [Secondary iron overload].

    PubMed

    Galactéros, F

    2000-05-01

    Secondary iron overload (SIO) constitutes a growing clinical problem, particularly in haematological diseases in which the improvements of life expectancy give the iron overload enough duration to play its own prognostic role. Iron may accumulate by two ways: transfusion and/(or) digestive hyperabsorption which is proportional to erythroïd plasma iron turnover. To properly evaluate the iron overloading one must be able to appreciate the cumulative red blood cell transfusion volumes. That is to say: weighting and counting red blood cell units. The magnitude of red blood cell precursor mass might be conveniently but indirectly evaluated by the measurement of the plasma transferrin receptor concentration. The group of haematological diseases, complicated by SIO to the contrary of primary haemochromatosis, is very heterogeneous. Some of them like hereditary dyserythropoiesis may not be obviously detectable on standard haematological observation. They can combine or not with hereditary haemochromatosis. A SIO must be treated when it may add a specific prognostic effect. In some cases, regular blood letting are usable without major problems. In all other cases iron chelation therapy is an effective way to reduce SIO, provided long term compliance is obtained. PMID:10865498

  13. Secondary Craters on Ganymede

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Two large, ancient impact craters, known as palimpsests, have modified this area of dark terrain on Jupiter's moon Ganymede. In lower resolution images from the Voyager mission in 1979, it was observed that the diffuse edge of a large, circular bright feature cut through this area. This image was obtained by the Solid State Imaging (CCD) system aboard NASA's Galileo spacecraft, on September 6, 1996, at a higher resolution of 190 meters (623 feet) per picture element (pixel). North is to the top. The diffuse margin of this palimpsest is noticeable only as a gradual increase in the area covered by bright hummocks toward the western edge of the image. A more recent palimpsest-forming impact to the south has peppered this area with chains and clusters of secondary craters ranging from 5.7 to 1.2 kilometers (3.5 to 0.7 miles) in diameter. The image covers an area of 73 by 65 kilometers (45 by 40 miles).

    The Jet Propulsion Laboratory, Pasadena, CA manages the Galileo mission for NASA's Office of Space Science, Washington, DC. JPL is an operating division of California Institute of Technology (Caltech).

    This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URL http://galileo.jpl.nasa.gov. Background information and educational context for the images can be found at URL http://www.jpl.nasa.gov/galileo/sepo

  14. Two-Stage Mineralization of Phenanthrene by Estuarine Enrichment Cultures

    PubMed Central

    Guerin, William F.; Jones, Galen E.

    1988-01-01

    The polycyclic aromatic hydrocarbon phenanthrene was mineralized in two stages by soil, estuarine water, and sediment microbial populations. At high concentrations, phenanthrene was degraded, with the concomitant production of biomass and accumulation of Folin-Ciocalteau-reactive aromatic intermediates. Subsequent consumption of these intermediates resulted in a secondary increase in biomass. Analysis of intermediates by high-performance liquid chromatography, thin-layer chromatography, and UV absorption spectrometry showed 1-hydroxy-2-naphthoic acid (1H2NA) to be the predominant product. A less pronounced two-stage mineralization pattern was also observed by monitoring 14CO2 production from low concentrations (0.5 mg liter?1) of radiolabeled phenanthrene. Here, mineralization of 14C-labeled 1H2NA could explain the incremental 14CO2 produced during the later part of the incubations. Accumulation of 1H2NA by isolates obtained from enrichments was dependent on the initial phenanthrene concentration. The production of metabolites during polycyclic aromatic hydrocarbon biodegradation is discussed with regard to its possible adaptive significance and its methodological implications. PMID:16347614

  15. Competing Fe (II)-induced mineralization pathways of ferrihydrite.

    PubMed

    Hansel, Colleen M; Benner, Shawn G; Fendorf, Scott

    2005-09-15

    Owing to its high surface area and intrinsic reactivity, ferrihydrite serves as a dominant sink for numerous metals and nutrients in surface environments and is a potentially important terminal electron acceptor for microbial respiration. Introduction of Fe (II), by reductive dissolution of Fe(III) minerals, for example, converts ferrihydrite to Fe phases varying in their retention and reducing capacity. While Fe(II) concentration is the master variable dictating secondary mineralization pathways of ferrihydrite, here we reveal thatthe kinetics of conversion and ultimate mineral assemblage are a function of competing mineralization pathways influenced by pH and stabilizing ligands. Reaction of Fe(II) with ferrihydrite results in the precipitation of goethite, lepidocrocite, and magnetite. The three phases vary in their precipitation extent, rate, and residence time, all of which are primarily a function of Fe(II) concentration and ligand type (Cl, SO4, CO3). While lepidocrocite and goethite precipitate over a large Fe(II) concentration range, magnetite accumulation is only observed at surface loadings greater than 1.0 mmol Fe(II)/g ferrihydrite (in the absence of bicarbonate). Precipitation of magnetite induces the dissolution of lepidocrocite (presence of Cl) or goethite (presence of SO4), allowing for Fe(III)-dependent crystal growth. The rate of magnetite precipitation is a function of the relative proportions of goethite to lepidocrocite; the lower solubility of the former Fe (hydr)oxide slows magnetite precipitation. A one unit pH deviation from 7, however, either impedes (pH 6) or enhances (pH 8) magnetite precipitation. In the absence of magnetite nucleation, lepidocrocite and goethite continue to precipitate at the expense of ferrihydrite with near complete conversion within hours, the relative proportions of the two hydroxides dependent upon the ligand present. Goethite also continues to precipitate at the expense of lepidocrocite in the absence of chloride. In fact, the rate and extent of both goethite and magnetite precipitation are influenced by conditions conducive to the production and stability of lepidocrocite. Thus, predicting the secondary mineralization of ferrihydrite, a process having sweeping influences on contaminant/nutrient dynamics, will need to take into consideration kinetic restraints and transient precursor phases (e.g., lepidocrocite) that influence ensuing reaction pathways. PMID:16201641

  16. Technical Subjects in Secondary Schools

    ERIC Educational Resources Information Center

    Howard, A. E.

    2008-01-01

    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…

  17. Language Study in Secondary Education.

    ERIC Educational Resources Information Center

    Stork, F. C.

    1980-01-01

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

  18. 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...

  19. Secondary Control Reviewed and Defined

    ERIC Educational Resources Information Center

    Morling, Beth; Evered, Sharrilyn

    2006-01-01

    Conclusions about secondary control have been hindered by researchers' disparate interpretations of the construct. The current review offers a definition that reflects commonality among researchers and the spirit of the original article (F. Rothbaum, J. R. Weisz, & S. S. Snyder, 1982): Secondary control refers to the process by which people adjust

  20. Secondary bacteremia following adenovirus infection.

    PubMed

    Lebel, Asaf; Ashkenazi-Hoffnung, Liat; Shkalim, Vered; Ben-Zvi, Haim; Dotan, Miri; Bilavsky, Efraim

    2016-05-01

    Adenovirus is a common pediatric pathogen responsible for a wide variety of infections. Despite this, secondary bacteremia following an adenovirus infection has not been previously systematically described. Herein, we describe seven cases of secondary bacteremia following an adenovirus infection in hospitalized children during an 8-year period. Pediatricians should be informed of this serious complication. PMID:26635067

  1. Preparing Preservice Secondary Special Educators

    ERIC Educational Resources Information Center

    Conderman, Greg; Johnston-Rodriguez, Sarah; Hartman, Paula; Kemp, Drew

    2013-01-01

    Through a mixed-methods study, teacher education faculty members investigated the implementation of a new block of courses and an associated secondary clinical experience designed to prepare preservice secondary special educators. Seventy-three preservice candidates (a) completed then-and-now surveys assessing their confidence implementing 25

  2. Elementary and Secondary School Enrollment.

    ERIC Educational Resources Information Center

    Education Statistics Quarterly, 2000

    2000-01-01

    Presents trends and project changes in enrollment across levels of education. Total public and private elementary and secondary school enrollment increased considerably during the late 1980s and 1990s, and it is projected to increase by 3% between 1998 and 2008, with the increase concentrated at the secondary school level. (SLD)

  3. Performance Art at Secondary Level

    ERIC Educational Resources Information Center

    Horn, Sheridan

    2009-01-01

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

  4. Sun, shade, and secondary metabolites

    Technology Transfer Automated Retrieval System (TEKTRAN)

    My research program focuses on understanding plant primary and secondary metabolites. Grape secondary metabolites, such as phenolics, have long been valuable for the organoleptic properties they impart to fruit and wine, and, more recently, for their possible health benefits. These compounds develop...

  5. Reading in the Secondary School.

    ERIC Educational Resources Information Center

    Teaching English, 1976

    1976-01-01

    The topic of discussion of this issue of the journal "Teaching English" is reading instruction in the secondary school. Articles include "Reading in the Primary School" (Alastair Hendry), "Patterns of Progress" (Fergus McBride), "Teaching Reading--Whose Business?" (James Maxwell), "A Reading Policy for the Secondary School" (Iain McGillivray),…

  6. Millersville University Secondary Education PDS

    ERIC Educational Resources Information Center

    Marcum-Dietrich, Nanette I.; Mahoney, Tim

    2015-01-01

    Millersville University of Pennsylvania (MU) has over 150 years of proud heritage in the preparation of teachers. This article describes how the Secondary Education Professional Development School (PDS) Program model has transformed Millersville University's secondary teacher education from a traditional teacher preparation program into a dynamic…

  7. Metabolomics for Secondary Metabolite Research

    PubMed Central

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

    2013-01-01

    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

  8. Microspacecraft Secondary Payload Mission Opportunities

    NASA Technical Reports Server (NTRS)

    Jones, Ross; Rademacher, Joel

    1997-01-01

    Worldwide secondary payload launch capabilities and future opportunities have been studied at the Jet Propulsion Laboratory (JPL). Launch vehicles have been identified as having near-term secondary payload opportunities for launching microspacecraft include: Pegasus, Taurus, LMLV-1, Delta II, Atlas II, Space Shuttle, Ariane 5, HIA, Molniya, Cosmos, and Proton.

  9. Preparing Preservice Secondary Special Educators

    ERIC Educational Resources Information Center

    Conderman, Greg; Johnston-Rodriguez, Sarah; Hartman, Paula; Kemp, Drew

    2013-01-01

    Through a mixed-methods study, teacher education faculty members investigated the implementation of a new block of courses and an associated secondary clinical experience designed to prepare preservice secondary special educators. Seventy-three preservice candidates (a) completed then-and-now surveys assessing their confidence implementing 25…

  10. 25 CFR 215.25 - Other minerals and deep-lying lead and zinc minerals.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 25 Indians 1 2010-04-01 2010-04-01 false Other minerals and deep-lying lead and zinc minerals. 215.25 Section 215.25 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR ENERGY AND MINERALS LEAD AND ZINC MINING OPERATIONS AND LEASES, QUAPAW AGENCY § 215.25 Other minerals and deep-lying...

  11. 25 CFR 215.25 - Other minerals and deep-lying lead and zinc minerals.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 25 Indians 1 2011-04-01 2011-04-01 false Other minerals and deep-lying lead and zinc minerals. 215.25 Section 215.25 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR ENERGY AND MINERALS LEAD AND ZINC MINING OPERATIONS AND LEASES, QUAPAW AGENCY § 215.25 Other minerals and deep-lying...

  12. 43 CFR 3873.1 - Segregation of mineral from non-mineral land.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 43 Public Lands: Interior 2 2014-10-01 2014-10-01 false Segregation of mineral from non-mineral... AND CONFLICTS Segregation 3873.1 Segregation of mineral from non-mineral land. Where a survey is... satisfactorily established that there are existent prior unpatented mining claims, the segregation of the...

  13. 43 CFR 3873.1 - Segregation of mineral from non-mineral land.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 43 Public Lands: Interior 2 2013-10-01 2013-10-01 false Segregation of mineral from non-mineral... AND CONFLICTS Segregation 3873.1 Segregation of mineral from non-mineral land. Where a survey is... satisfactorily established that there are existent prior unpatented mining claims, the segregation of the...

  14. 43 CFR 3873.1 - Segregation of mineral from non-mineral land.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 43 Public Lands: Interior 2 2011-10-01 2011-10-01 false Segregation of mineral from non-mineral... AND CONFLICTS Segregation 3873.1 Segregation of mineral from non-mineral land. Where a survey is... satisfactorily established that there are existent prior unpatented mining claims, the segregation of the...

  15. 43 CFR 3873.1 - Segregation of mineral from non-mineral land.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 43 Public Lands: Interior 2 2012-10-01 2012-10-01 false Segregation of mineral from non-mineral... AND CONFLICTS Segregation 3873.1 Segregation of mineral from non-mineral land. Where a survey is... satisfactorily established that there are existent prior unpatented mining claims, the segregation of the...

  16. Minerals yearbook: Minerals industries of Asia and the Pacific. Volume 3. 1993 international review

    SciTech Connect

    1993-12-31

    This edition of the Minerals Yearbook records the performance of the worldwide minerals industry during 1993 and provides background information to assist in interpreting that performance. This report is on the Mineral Industries of Asia and the Pacific, and it contains production and consumption data on mineral commodities of this region.

  17. 43 CFR 3594.5 - Minerals soluble in water; brines; minerals taken in solution.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

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  18. 25 CFR 215.25 - Other minerals and deep-lying lead and zinc minerals.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 25 Indians 1 2012-04-01 2011-04-01 true Other minerals and deep-lying lead and zinc minerals. 215.25 Section 215.25 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR ENERGY AND MINERALS LEAD AND ZINC MINING OPERATIONS AND LEASES, QUAPAW AGENCY 215.25 Other minerals and deep-lying...

  19. 25 CFR 215.25 - Other minerals and deep-lying lead and zinc minerals.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 25 Indians 1 2014-04-01 2014-04-01 false Other minerals and deep-lying lead and zinc minerals. 215.25 Section 215.25 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR ENERGY AND MINERALS LEAD AND ZINC MINING OPERATIONS AND LEASES, QUAPAW AGENCY 215.25 Other minerals and deep-lying...

  20. 25 CFR 215.25 - Other minerals and deep-lying lead and zinc minerals.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 25 Indians 1 2013-04-01 2013-04-01 false Other minerals and deep-lying lead and zinc minerals. 215.25 Section 215.25 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR ENERGY AND MINERALS LEAD AND ZINC MINING OPERATIONS AND LEASES, QUAPAW AGENCY 215.25 Other minerals and deep-lying...