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1

Chronostratigraphy of Monte Vulture volcano (southern Italy): secondary mineral microtextures and 39Ar-40Ar systematics  

NASA Astrophysics Data System (ADS)

The eruptive history of Monte Vulture has been the subject of several geochronological investigations during the past decades, which reliably dated only a small number of eruptions. Understanding the causes of sub-optimum data yield in the past requires an interdisciplinary approach. We re-analyzed samples from previous works and present new data on samples from the main volcano-stratigraphic units of Monte Vulture, so as to provide an improved, consistent chronostratigraphic database. Imaging of minerals by cathodoluminescence and backscattered electrons reveals that heterochemical, high-temperature deuteric reaction textures are ubiquitous. Such observations are common in metamorphic rocks but had not frequently been reported from volcanic rocks. In view of the mineralogical complexity, we base our chronological interpretation on isochemical steps, defined as steps for which the Cl/K and/or the Ca/K ratios are constant. Isochemical steps carry the isotopic signature of chemically homogeneous mineral phases and therefore allow a well-constrained age interpretation. Comparison of old and new 39Ar-40Ar data proves the reproducibility of age spectra and their shapes. This quantifies the analytical reliability of the irradiation and mass-spectrometric analyses. Anomalous age spectra are a reproducible property of some specific samples and correlate with mineralogical anomalies. The present data allow us to fine-tune the age of the volcanostratigraphic units of Monte Vulture during the known interval of main volcanic activity from ca. 740 to 610 ka. After a very long stasis, the volcanic activity in the Monte Vulture area resumed with diatremic eruptions, one of which (Lago Piccolo di Monticchio, the site of a palynological-paleoclimatological drilling) was dated at ca. 140 ka.

Villa, Igor M.; Buettner, Annett

2009-12-01

2

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

NASA Astrophysics Data System (ADS)

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.

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

2013-12-01

3

Mars weathering analogs - Secondary mineralization in Antarctic basalts  

NASA Technical Reports Server (NTRS)

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

Berkley, J. L.

1982-01-01

4

Mars weathering analogs - Secondary mineralization in Antarctic basalts  

NASA Astrophysics Data System (ADS)

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

Berkley, J. L.

5

Secondary sulfate minerals from Alum Cave Bluff: Microscopy and microanalysis  

Microsoft Academic Search

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,

Lauf

1997-01-01

6

Bisphosphonates do not Alter the Rate of Secondary Mineralization  

SciTech Connect

Bisphosphonates function to reduce bone turnover, which consequently increases the mean degree of tissue mineralization at an organ level. However, it is not clear if bisphosphonates alter the length of time required for an individual bone-modeling unit (BMU) to fully mineralize. We have recently demonstrated that it takes {approx}350 days (d) for normal, untreated cortical bone to fully mineralize. The aim of this study was to determine the rate at which newly formed trabecular BMUs become fully mineralized in rabbits treated for up to 414 d with clinical doses of either risedronate (RIS) or alendronate (ALN). Thirty-six, 4-month old virgin female New Zealand white rabbits were allocated to RIS (n=12; 2.4 {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.

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

2011-12-31

7

Bisphosphonates do not alter the rate of secondary mineralization  

SciTech Connect

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

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

2011-05-18

8

Secondary sulfate minerals from Alum Cave Bluff: Microscopy and microanalysis  

SciTech Connect

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.

Lauf, R.J.

1997-07-01

9

Ion beam microtexturing and enhanced surface diffusion  

NASA Technical Reports Server (NTRS)

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.

Robinson, R. S.

1982-01-01

10

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

NASA Astrophysics Data System (ADS)

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

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

2012-04-01

11

Time sequence of secondary mineralization and microhardness in cortical and cancellous bone from ewes.  

PubMed

Bone mineral is a major determinant of the mechanical resistance of bones. In bone structural units (BSUs), mineralization of osteoid tissue begins with a rapid primary mineralization followed by a secondary mineralization phase, i.e., a slow and gradual maturation of the mineral component leading to complete mineralization during an unknown period. The aim of this study was to determine the chronology of secondary bone mineralization in ewes, an animal model with a remodeling activity close to humans. Eighteen ewes received different fluorescent labels every 6 months to date the "age" of each labeled BSU. The degree of mineralization of bone (DMB) and Vickers microhardness were measured in labeled BSUs, while mineralization at the crystal level was assessed by Fourier transform infrared microspectroscopy (FTIRM). During the first 6 months of mineralization, degree of mineralization and microhardness significantly increased. They then increased more slowly until at 30 months they reach their maximal values. This progression during secondary mineralization was associated with an improvement of both the maturation and the crystal perfection of the mineral part of bone matrix. Finally, secondary mineralization in BSUs is completed after a period of 30 months. This observation should be taken into account for understanding the effects of long-term treatments of bone diseases. PMID:19969115

Bala, Yohann; Farlay, Delphine; Delmas, Pierre D; Meunier, Pierre J; Boivin, Georges

2010-04-01

12

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

Microsoft Academic Search

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

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

2003-01-01

13

Origin of secondary sulfate minerals on active andesitic stratovolcanoes  

Microsoft Academic Search

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, Citlaltépetl (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

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

2005-01-01

14

Microtextured Silicon Surfaces for Detectors, Sensors & Photovoltaics  

SciTech Connect

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

Carey, JE; Mazur, E

2005-05-19

15

The Chronology of Asteroid Accretion, Differentiation, and Secondary Mineralization  

NASA Technical Reports Server (NTRS)

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

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

2008-01-01

16

Oxygen Isotopes and Geothermometry of Secondary Minerals in CR Chondrites  

NASA Astrophysics Data System (ADS)

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

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

2014-09-01

17

[Secondary osteoporosis UPDATE. How to diagnose secondary osteoporosis and disorders presenting low bone mineral density].  

PubMed

Involutional osteoporosis is one of common diseases related to ageing. However, it is essential for physicians to exclude possibilities that it is caused by certain background diseases or disorders, such as hypercortisolism, hyperthyroidism and type 1 diabetes mellitus. In addition, there are several diseases other than osteoporosis, that are known to be associated with low bone mineral density, although osteoporosis is usually diagnosed according to bone mineral density measurements. Thus, physicians should be prepared to appropriately evaluate how bone metabolism is impaired in the face of patients with low bone mineral density. PMID:20445277

Takeuchi, Yasuhiro

2010-05-01

18

Friction characteristics of microtextured surfaces under mixed and hydrodynamic lubrication  

E-print Network

Friction characteristics of microtextured surfaces under mixed and hydrodynamic lubrication Ashwin Keywords: Surface engineering Microtexturing Hydrodynamic lubrication Mixed lubrication a b s t r a c t We. During hydrodynamic lubricated sliding, the textured surfaces exhibit friction as much as 80% lower than

King, William P.

19

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

NASA Astrophysics Data System (ADS)

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

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

2011-12-01

20

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

Microsoft Academic Search

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

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

1983-01-01

21

Weathering features and secondary minerals in Antarctic Shergottites ALHA77005 and LEW88516  

NASA Technical Reports Server (NTRS)

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

Wentworth, Susan J.; Gooding, James L.

1993-01-01

22

The Paris CM chondrite: Secondary minerals and asteroidal processing  

NASA Astrophysics Data System (ADS)

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

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

2014-07-01

23

Alteration Products and Secondary Minerals in Martian Meteorite Allan Hills 84001  

NASA Technical Reports Server (NTRS)

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.

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

1998-01-01

24

Method of making a coating of a microtextured surface  

DOEpatents

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

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

2004-11-02

25

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

SciTech Connect

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

Wang, Guohui; Um, Wooyong

2012-11-23

26

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

NASA Astrophysics Data System (ADS)

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.

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

2014-01-01

27

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

NASA Astrophysics Data System (ADS)

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

Wang, Guohui; Um, Wooyong

2012-11-01

28

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 ...

29

Inhibition effect of secondary phosphate mineral precipitation on uranium release from contaminated sediments.  

PubMed

The inhibitory effect of phosphate mineral precipitation on diffusion-limited uranium release was evaluated using a U(VI)-contaminated sediment collected from the U.S. Department of Energy Hanford site. The sediment contained U(VI) that was associated with diffusion-limited intragrain regions within its millimeter-sized 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 the stoichiometric ratio of the mineral hydroxyapatite. The phosphate-treated sediment was then leached to solubilize contaminant U(VI) in a column system using a synthetic groundwater solution with 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 1 and 2 orders of magnitude after the sediment was treated with 1 and 50 mM of phosphate, respectively. Measurements of solid-phase U(VI) using laser-induced fluorescence spectroscopy, scanning electron microscopy, 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 original U(VI) mineral phases to less soluble forms. PMID:19924967

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

2009-11-01

30

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

SciTech Connect

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.

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

2009-11-01

31

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

NASA Astrophysics Data System (ADS)

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

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

2014-11-01

32

Electrically conducting superhydrophobic microtextured carbon nanotube nanocomposite  

NASA Astrophysics Data System (ADS)

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

Caffrey, Paul O.; Gupta, Mool C.

2014-09-01

33

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

NASA Astrophysics Data System (ADS)

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

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

34

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

PubMed Central

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

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

2011-01-01

35

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

SciTech Connect

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

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

2012-05-01

36

Minerals  

MedlinePLUS

... Aren't minerals something you find in the earth, like iron and quartz? Well, yes, but small ... how much of these minerals you need each day. Trace minerals includes iron, manganese, copper, iodine, zinc, ...

37

Minerals  

NSDL National Science Digital Library

This site provides an in-depth look at mineral properties and identification. An alphabetical listing of common minerals allows the user to see a picture and view physical properties of the particular mineral. Properties of minerals are explained, including cleavage, hardness, crystal form, and luster. There are also downloadable labs for crystal models and mineral data sheets. Dichotomous and hardness keys are given for easier mineral identification.

2007-12-12

38

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

SciTech Connect

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.

Nagy, Kathryn L.; Sturchio, Neil C.

2003-06-01

39

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

PubMed Central

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

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

2015-01-01

40

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

PubMed

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

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

2015-01-01

41

Minerals  

NSDL National Science Digital Library

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

42

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

SciTech Connect

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.

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

2009-02-25

43

The Pathophysiology of Secondary Hyperparathyroidism and the Consequences of Uncontrolled Mineral Metabolism in Chronic Kidney Disease: The Role of COSMOS  

Microsoft Academic Search

The development of secondary hyperparathyroidism (SHPT) is a common complication of chronic kidney disease. SHPT develops as a consequence of mineral metabolism disturbances and is characterized by elevated serum parathyroid hormone (PTH) and parathyroid hyper- plasia. Evidence suggests that SHPT contributes to the development of vascular calcification and cardiovascular disease, as well as to the development of renal osteodys- trophy.

Jorge B. Cannata-And ´ õa; Fernando Carrera

2008-01-01

44

Minerals  

NSDL National Science Digital Library

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

Michael Passow

45

Optimal design of superhydrophobic surfaces using a paraboloid microtexture.  

PubMed

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

Tie, Lu; Guo, Zhiguang; Li, Wen

2014-12-15

46

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

SciTech Connect

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

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

1981-01-01

47

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

Microsoft Academic Search

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

Kim A. Waldron; Ian Parsons

1992-01-01

48

Biomimetic microtexturing for neurosurgical probe surfaces to influence tribological characteristics during tissue penetration  

E-print Network

Biomimetic microtexturing for neurosurgical probe surfaces to influence tribological Keywords: Biomimetics Microtexturing SU-8 Si Silicone Biomedical device Neurosurgical probe a b s t r a c systems (MEMS) were employed to engineer this novel biomimetic neurosurgical probe using SU-8 photoresist

49

Secondary uranium mineralization in southern Finland and its relationship to recent glacial events  

NASA Astrophysics Data System (ADS)

Uranium series dating has been carried out on secondary uranyl silicate minerals formed during sub-glacial and post-glacial weathering of Proterozoic uraninite ores in south west Finland. The samples were obtained from two sites adjacent to the Salpauselkä III ice marginal formation and cover a range of depths, from the surface to more than 60 m. Measured ages fall into three distinct groups, 70-100 ka, 28-36 ka and < 2500 yr. The youngest set is associated with surface exposures and the crystals display clear evidence of re-working. The most likely trigger for uranium release at depths below the surface weathering zone is intrusion of oxidising glacial melt water. The latter is often characterised by very high discharge rates along channels, which close once the overpressure generated at the ice margin is released. There is excellent correspondence between the two Finnish sites and published data for similar deposits over a large area of southern and central Sweden. None of the seventy samples analysed gave a U-Th age between 40 and 70 ka; a second hiatus is apparent at 20 ka, coinciding with the Last Glacial Maximum. Thus, the process responsible for uranyl silicate formation was halted for significant periods, owing to a change in geochemical conditions or the hydrogeological regime. These data support the presence of interstadial conditions during the Early and Middle Weichselian since in the absence of major climatic perturbations the uranium phases at depth are stable. When viewed in conjunction with proxy data from mammoth remains it would appear that the region was ice-free prior to the Last Glacial Maximum.

Read, David; Black, Stuart; Buckby, Tracy; Hellmuth, Karl-Heinz; Marcos, Nuria; Siitari-Kauppi, Marja

2008-02-01

50

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

SciTech Connect

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.

Whitbeck, M.; Glassley, W.

1998-02-01

51

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

NASA Astrophysics Data System (ADS)

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

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

2011-12-01

52

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

USGS Publications Warehouse

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

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

2009-01-01

53

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)

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.

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

2009-05-01

54

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

NASA Astrophysics Data System (ADS)

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

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

2015-01-01

55

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

PubMed

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

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

2015-01-25

56

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

SciTech Connect

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

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

2013-01-01

57

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

NASA Astrophysics Data System (ADS)

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

Goodfellow, Bradley W.

2012-12-01

58

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

NASA Astrophysics Data System (ADS)

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

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

2015-02-01

59

Control of pit-lake water chemistry by secondary minerals, Summer Camp pit, Getchell mine, Nevada  

Microsoft Academic Search

At the Summer Camp pit of the Getchell mine in northern Nevada, the sulfate mineralogy is complex and includes gypsum, jarosite, pickeringite–halotrichite, copiapite, melanterite, langite, and bukovskyite that occur along with scorodite–mansfieldite and Ca–Cu–Zn arsenate minerals. Leaching of these minerals by meteoric water seasonally contributes As, Fe, Ca, trace metals, sulfate, and hydrogen ions to the lake. During the early

R. J. Bowell; J. V. Parshley

2005-01-01

60

Secondary minerals from extrapedogenic per latus acidic weathering environments at geomorphic edges, Eastern Nebraska, USA  

Microsoft Academic Search

Acidic weathering of the sulfidic Upper Cretaceous Carlile and Pierre Shales in Nebraska has led to the precipitation of the Al sulfate–hydroxide minerals aluminite, alunite, “basaluminite”\\/felsöbányaite (e.g.,), the aluminum hydroxides gibbsite and bayerite, and the rare Al phosphate hydroxide vashegyite. Kaolinite has also been produced as a result of this acidic weathering. These minerals do not appear as neoformed constituents

R. M. Joeckel; K. D. Wally; B. J. Ang Clement; P. R. Hanson; J. S. Dillon; S. K. Wilson

2011-01-01

61

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

E-print Network

-thiophene):poly(styrenesulfonate) (PEDOT:PSS) directly spun-cast on micro-textured n-type crystalline silicon wafers. The fabrication-diffusion model is then developed based on fitting the device characteristics with experimentally determined PEDOT

62

Collagen type-I leads to in vivo matrix mineralization and secondary stabilization of Mg-Zr-Ca alloy implants.  

PubMed

Biodegradable magnesium-zirconia-calcium (Mg-Zr-Ca) alloy implants were coated with Collagen type-I (Coll-I) and assessed for their rate and efficacy of bone mineralization and implant stabilization. The phases, microstructure and mechanical properties of these alloys were analyzed using X-ray diffraction (XRD), optical microscopy and compression test, respectively, and the corrosion behavior was established by their hydrogen production rate in simulated body fluid (SBF). Coll-I extracted from rat tail, and characterized using fourier transform infrared (FT-IR) spectroscopy, was used for dip-coating the Mg-based alloys. The coated alloys were implanted into the femur bones of male New Zealand white rabbits. In vivo bone formation around the implants was quantified by measuring the bone mineral content/density (BMC/BMD) using dual-energy X-ray absorptiometry (DXA). Osseointegration of the implant and new bone mineralization was visualized by histological and immunohistochemical analysis. Upon surface coating with Coll-I, these alloys demonstrated high surface energy showing enhanced performance as an implant material that is suitable for rapid and efficient new bone tissue induction with optimal mineral content and cellular properties. The results demonstrate that Coll-I coated Mg-Zr-Ca alloys have a tendency to form superior trabecular bone structure with better osteoinduction around the implants and higher implant secondary stabilization, through the phenomenon of contact osteogenesis, compared to the control and uncoated ones in shorter periods of implantation. Hence, Coll-I surface coating of Mg-Zr-Ca alloys is a promising method for expediting new bone formation in vivo and enhancing osseointegration in load bearing implant applications. PMID:25179112

Mushahary, Dolly; Wen, Cuie; Kumar, Jerald Mahesh; Lin, Jixing; Harishankar, Nemani; Hodgson, Peter; Pande, Gopal; Li, Yuncang

2014-10-01

63

minerals  

NASA Astrophysics Data System (ADS)

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

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

2014-10-01

64

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

SciTech Connect

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

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

1989-01-01

65

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

SciTech Connect

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

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

2013-06-03

66

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

NASA Astrophysics Data System (ADS)

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

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

2012-12-01

67

Localization of mineral elements in normal and strontium-intoxicated quail eggshell by secondary ion mass spectroscopy and electron probe microanalysis  

Microsoft Academic Search

Summary  Localization of mineral elements in the shell of quail eggs was studied by secondary ion mass spectrometry (SIMS) and electron\\u000a probe microanalysis (EPMA). Normal eggs as well as eggs from hens intoxicated with strontium were studied.\\u000a \\u000a A simple preparative technique was employed that is advantageous for the study of mineralized tissues. Semithin (1 m) sections\\u000a of material embedded in Araldite

Carmen Quintana; Annick Quettier; Daniel Sandoz

1980-01-01

68

Mineral Association Changes the Secondary Structure and Dynamics of Murine Amelogenin  

SciTech Connect

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.

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

2013-12-18

69

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

SciTech Connect

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

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

2013-12-02

70

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

SciTech Connect

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

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

2013-10-01

71

MDD Analysis of Microtexturally Characterized K-Feldspar Fragments  

NASA Astrophysics Data System (ADS)

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

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

2011-12-01

72

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

PubMed

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

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

2014-04-15

73

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

NASA Astrophysics Data System (ADS)

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

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

2015-02-01

74

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)

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.

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

2013-12-01

75

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

Microsoft Academic Search

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

R Gieré; N. V Sidenko; E. V Lazareva

2003-01-01

76

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

NASA Astrophysics Data System (ADS)

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

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

2011-12-01

77

Rare earth element redistribution and fractionation during secondary mineral formation: examples from reef carbonate karst (Jebel Stah, Tunisia) and from oceanic basalts (site 417A, Northern Atlantic)  

NASA Astrophysics Data System (ADS)

Rare earth element (REE) distributions of fluorite-carbonate deposits from Northern Tunisia (Jebel Stah) and submarine alteration products of oceanic basalts from the Northern Atlantic (site 417A, D.S.D.P., Leg 51-53) were studied. The REE distributions of secondary minerals infilling karst at the Jebel Stah clearly illustrate the mobility and fractionation of the group. Calcite concentrates the highest amounts of REE (10 2 orders of higher magnitude) and is heavy REE enriched, whereas fluorite has the lower values and shows heavy but clearly medium REE enrichment. These fractionation and distributions are thought to be due to the effects of carbonate and/or fluoride complexes on the REE behaviour during the formation of secondary minerals. Celadonite-nontronite, saponite and Fe-oxyhydroxides formed early during submarine alteration, exhibit REE contents and distributions always similar to those of parental basalts, although they gained Ce and thus present positive Ce anomalies. Beidellites of the intermediary alteration stages show great heavy REE depleted REE curves and this is apparently due to chemical modifications where the increase of the CO 2 partial pressure and REE-carbonate complex caused losses of the heavy REE relative to lighter members of the group. Thereafter, heavy REE complexes were probably released later along with the diminution of the CO 2 partial pressure and precipitation of calcite and analcite and thus the heavy REE were accumulated in minerals of the latest stages. These fractionation and distributions of the REE during the secondary formation of minerals in karst and during the submarine alteration of basalts are thought to be due to effects of carbonate and/or fluoride complexes on the REE behaviour in the milieu.

Tlig, S.

78

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

NASA Astrophysics Data System (ADS)

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

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

2013-11-01

79

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

PubMed

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

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

2012-07-01

80

Droplet-based Microtexture Biochip System for Triglycerides and Methanol Measurement  

Microsoft Academic Search

A droplet-based microfluidic system was developed for biochemical assays of triglycerides and methanol as potential applications in medical rapid diagnostics and food safety. We present a novel platform to manipulate biology reaction droplets with features of self-moving, self-mixing, and self-positioning toward the detection spot. The driving force comes from the gradient of surface tension force generated by the hydrophobic microtexture

Ming-Yu Lin; Chih-Sheng Yu; Yi-Chiuen Hu; Shao-Chang Cheng; Heng-Tsang Hu

2005-01-01

81

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

Microsoft Academic Search

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

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

2010-01-01

82

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

NASA Astrophysics Data System (ADS)

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

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

2014-10-01

83

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

SciTech Connect

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

Kathryn L. Nagy

2004-04-22

84

Cadmium, copper, lead, and zinc in secondary sulfate minerals in soils of mined areas in Southeast Spain  

Microsoft Academic Search

Soils in mined areas in southeastern Spain are commonly characterized by extreme acidity, high salinity, and metals. These present challenges to establish vegetation as a management option for these environmentally-problematic landscapes. We collected salt efflorescence and the corresponding soil materials to better understand the geochemical cycling of Cd, Cu, Pb, and Zn in soils of mined areas. Mineral composition was

D. M. Carmona; Á. Faz Cano; J. M. Arocena

2009-01-01

85

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

USGS Publications Warehouse

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

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

2005-01-01

86

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

NASA Astrophysics Data System (ADS)

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

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

2012-12-01

87

Droplet-based Microtexture Biochip System for Triglycerides and Methanol Measurement.  

PubMed

A droplet-based microfluidic system was developed for biochemical assays of triglycerides and methanol as potential applications in medical rapid diagnostics and food safety. We present a novel platform to manipulate biology reaction droplets with features of self-moving, self-mixing, and self-positioning toward the detection spot. The driving force comes from the gradient of surface tension force generated by the hydrophobic microtexture PDMS surface. We also demonstrate the experiments in water, and blood droplets running uphill to overcome the gravity. These findings support the ongoing works to develop the multifunctional biosensors in medicine and food safety. PMID:17282234

Lin, Ming-Yu; Yu, Chih-Sheng; Hu, Yi-Chiuen; Cheng, Shao-Chang; Hu, Heng-Tsang

2005-01-01

88

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

PubMed

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

Dublyansky, Yuri V; Smirnov, Sergey Z

2005-04-01

89

Use of Cu isotopes to distinguish primary and secondary Cu mineralization in the Cañariaco Norte porphyry copper deposit, Northern Peru  

NASA Astrophysics Data System (ADS)

A significant proportion of the copper in the Cañariaco Norte porphyry copper deposit in northern Peru occurs in chalcocite and covellite-rich veins and disseminations that exist from the surface to depths greater than 1 km. The overall range of Cu isotopic ratios of 42 mineral separates from Cañariaco varies from -8.42 to 0.61 ‰, with near-surface chalcocite and Fe oxides having isotopically depleted values compared to chalcocite, covellite, and chalcopyrite from deeper levels. The majority (34 of 36) of measured Cu sulfides have a typical hypogene copper isotope composition of ?65Cu = 0.18 ± 0.38 ‰, with no enriched isotopic signature existing in the Cañariaco Norte sulfide data. Thus, the copper isotope data indicate that most of the chalcocite and covellite formed from high-temperature hypogene mineralization processes and that only a minor portion of the deposit is enriched by supergene processes. The nonexistence of an enriched ?65Cu reservoir suggest the presence of an undiscovered lateral/exotic Cu occurrence that enriched 65Cu that remained in solution during weathering. Regardless of the cause, the comparative analysis of the Cu isotope dataset reveals that little exploration potential for an extensive supergene enrichment blanket exists because the weathering history at Cañariaco Norte was not conducive to preservation of enriched Cu at depth beneath the leach cap.

Mathur, Ryan; Ruiz, Joaquin; Casselman, Michael J.; Megaw, Peter; van Egmond, Robert

2012-10-01

90

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

PubMed

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

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

2010-06-15

91

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

USGS Publications Warehouse

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

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

2003-01-01

92

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

USGS Publications Warehouse

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

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

2006-01-01

93

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

SciTech Connect

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.

Kathryn L. Nagy

2009-05-04

94

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

SciTech Connect

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

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

2012-07-01

95

Osteoblast maturation on microtextured titanium involves paracrine regulation of bone morphogenetic protein signaling.  

PubMed

Osteoblasts are sensitive to surface microtopography and chemistry. Osteoblast differentiation and maturation are higher in vitro and bone formation and osseointegration enhanced in vivo on microstructured titanium (Ti) compared to smooth surfaces. Cells increased BMP2 expression on microtextured Ti alloy, suggesting a paracrine role in regulating osteoblast maturation. However, recent studies show that exogenous BMP2 inhibits osteoblast production of anti-inflammatory cytokines and osteocalcin, indicating that control of BMP-signaling may be involved. This study examined whether cells modulate BMP ligands, receptors, and inhibitors during osteoblast maturation on Ti, specifically focusing on the roles of BMP2 and Noggin (NOG). mRNA and protein for BMP2, BMP4, and BMP7 and receptors BMPR1A, BMPR1B, and BMPR2, and BMP inhibitors were upregulated on microtextured surfaces in comparison to smooth surfaces. Maturation on microstructured Ti was slightly enhanced with exogenous BMP2 while NOG addition inhibited osteoblast maturation. Cells with NOG knocked down significantly increased osteoblast maturation. These results demonstrate that BMP-related molecules are controlled during osteoblast maturation on microstructured Ti surfaces and that endogenous NOG is an important regulator of the process. Modifying paracrine BMP signaling may yield more robust bone formation than application of exogenous BMPs. © 2014 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 103A: 1721-1731, 2015. PMID:25111281

Olivares-Navarrete, Rene; Hyzy, Sharon L; Pan, Qingfen; Dunn, Ginger; Williams, Joseph K; Schwartz, Zvi; Boyan, Barbara D

2015-05-01

96

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

NASA Astrophysics Data System (ADS)

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

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

2010-07-01

97

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

NASA Technical Reports Server (NTRS)

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

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

2005-01-01

98

RADIOACTIVE DEMONSTRATION OF FINAL MINERALIZED WASTE FORMS FOR HANFORD WASTE TREATMENT PLANT SECONDARY WASTE BY FLUIDIZED BED STEAM REFORMING USING THE BENCH SCALE REFORMER PLATFORM  

SciTech Connect

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

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

2012-02-02

99

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

NASA Astrophysics Data System (ADS)

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

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

2013-01-01

100

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

PubMed

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

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

2013-12-01

101

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

USGS Publications Warehouse

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.

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

2008-01-01

102

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)

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.

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

2008-04-01

103

Mineral County Secondary Data Analysis  

E-print Network

,4 Stroke prevalence 2.5% 2.5% 2.6% Diabetes prevalence 5.6% 6.2% 8.3% Acute Myocardial Infarction prevalence (Heart Attack) 4.0% 4.1% 6.0% All Sites Cancer 466.5 455.5 543.2 1 Community Health Data, MT, Missoula, and Ravalli Chronic Disease Hospitalization Rates County Montana Stroke1 Per 100

Maxwell, Bruce D.

104

Australian Mineral Foundation.  

ERIC Educational Resources Information Center

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

Crowe, D. S.

1980-01-01

105

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

NASA Astrophysics Data System (ADS)

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

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

2014-05-01

106

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

PubMed Central

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

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

2008-01-01

107

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

PubMed

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

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

2012-12-01

108

Microtextured metals for stray-light suppression in the Clementine startracker  

NASA Technical Reports Server (NTRS)

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

Johnson, E. A.

1993-01-01

109

Microtextural evolution of different TRC AA8006 alloy sections with homogenization  

NASA Astrophysics Data System (ADS)

Grain microtexture evolution in twin-roll cast AA8006 alloy sheets subjected to different treatments was investigated using electron backscatter diffraction. The textures of rolling-transverse and normal-transverse sections were characterized in original as-cast twin-roll casting and cold-rolled samples as well as samples homogenized at 500°C for 8 h and at 580°C for 4 h. It is found that grains on both the rolling-transverse and normal-transverse sections of cold-rolled samples are made finer by rolling deformation and coarsened after homogenization. Annealing temperature has a stronger effect on the microstructural evolution than annealing time. The grain growth direction is parallel to the normal-transverse section, while grain deformation is more stable on the rolling direction than on the normal direction. The rolling orientations display more obvious anisotropy on the normal-transverse sections than on the rolling-transverse sections. Grain recrystallization and growth occur much easier on the normal-transverse section than on the rolling-transverse section for samples homogenized at 500°C for 8 h. A special misorientation relationship between cold deformation texture, such as S orientation {123}<634> and cube orientation <110>? X axis [cubic], and recrystallization texture after homogenization, such as R orientation {124}<211> and P orientation {011}<122>, is observed.

Chen, Zhong-wei; Shen, Long-fei; Zhao, Jing

2015-03-01

110

Enumeration of Thiobacilli within pH-Neutral and Acidic Mine Tailings and Their Role in the Development of Secondary Mineral Soil  

PubMed Central

The Lemoine tailings of Chibougamau, Quebec, Canada, were deposited as a pH-neutral mineral conglomerate consisting of aluminum-silicates, iron-aluminum-silicates, 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 × 108 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 (below 40 cm) to chlorides and phosphates (at the surface). 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 material 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 and electron dispersive spectroscopy that they were being immobilized as bona fide fine-grain minerals 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. Images PMID:16348721

Southam, G.; Beveridge, T. J.

1992-01-01

111

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

NASA Astrophysics Data System (ADS)

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

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

2014-05-01

112

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

PubMed

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

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

2013-05-22

113

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

PubMed

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

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

2011-11-15

114

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

NASA Astrophysics Data System (ADS)

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.

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

2013-12-01

115

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)

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.

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

2014-04-01

116

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

NASA Astrophysics Data System (ADS)

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

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

2014-09-01

117

Secondary osteoporosis in women  

Microsoft Academic Search

Secondary osteoporosis comprises a minority of all osteoporosis cases. In this study we summarize the causes of secondary\\u000a osteoporosis we encountered in patients currently on follow-up in our osteoporosis outpatient clinic. A total of 1015 female\\u000a patients are involved in the study. Recorded data of the patients are evaluated retrospectively. Patients with spine bone\\u000a mineral density (BMD) 2.5 standard deviation

B. Çakir; E. Odabasi; M. Turan; S. Güler; M. Kutlu

2002-01-01

118

A petrographic, geochemical and isotopic (O, H, C and Sr) investigation of secondary minerals in volcaniclastic rocks at Minna Bluff, Antarctica: Petrogenesis of alteration and implications for paleoenvironmental conditions  

NASA Astrophysics Data System (ADS)

The alteration of volcanic deposits is a function of eruptive style, environment of deposition and post-depositional processes. In this study we use petrographic and geochemical data on secondary minerals in volcaniclastic deposits at Minna Bluff, a 45-km-long volcanic peninsula in the southern Ross Sea active between 12 and 4 Ma, to unravel their history and study the environmental conditions responsible for their alteration. Glassy volcaniclastic deposits, including lapilli tuff, hyaloclastite breccia and volcanic sediments, have been altered to contain secondary minerals zeolite, carbonate and rare chalcedony and clay (dickite). Carbonates include calcite, Mg-calcite (MgCO3> 4 to <48 mol%), dolomite, magnesite, siderite and rhodochrosite. Zeolites include phillipsite and chabazite and have high and variable alkali contents (Na+K/Ca up to 154) relative to fresh lavas (<15). During the alteration of these deposits, phillipsite formed first followed by chabazite and/or carbonate although carbonates are still thought to be a very early diagenetic precipitate. Compositional zoning in zeolites is poorly developed while carbonates are commonly complex showing changes in Fe, Mn and Sr and Mg/Ca ratios across layers. Carbonate ?18O and ?13C values show wide variations ranging from -0.50 to 21.53‰ and -1.04 to 8.98‰, respectively. Chalcedony ?18O, measured on multiple aliquots from individual vugs and within each vug from one sample, range from 0.68 to 10.37‰ and ?D values are light (-187.8 to -220.6‰), matching Antarctic meteoric water. A mean 87Sr/86Sr ratio of 0.70327 ±0.0009 (1?, n = 12) for carbonates is comparable to values from lavas in this region (Erebus Volcanic Province), indicating that seawater even at low elevations (<40 m asl) was not involved in the alteration of these deposits. Field relationships and laboratory results indicate that alteration and associated mineral precipitation was a result of isolated, ephemeral events involving the exchange between meteoric water (ice and snow) and glass-rich volcaniclastics during or soon after the formation of each deposit. Changing conditions between anoxic and oxic environments are indicated by variations in the intensity of luminescence and Fe2+/Mn ratios measured in zoned carbonates. Secondary minerals were formed at elevated temperatures based on the stability of the zeolites (10°-99°C) and refined further using estimates from carbonate 13C-18O paleothermometry (5°-43°C). Evaporative distillation, possibly from steam vents, can explain enriched 18O compositions of some Mg-rich carbonates and chalcedony. The results may provide a record of climate variability during the growth of Minna Bluff. Using the estimated temperatures of formation and published fractionation factors, the ?18O of meteoric water in equilibrium with carbonates is calculated. In conjunction with estimates for the timing of alteration constrained by lavas dated above and below each deposit, these data reveal a broad shift from lighter (-24‰) to heavier (-16‰) values between ~11 and ~8.5 Ma, consistent with a period of climate warming. These findings are independently corroborated by the interpretation of Late Miocene sedimentary sequences recovered from the nearby AND-1B core.

Antibus, J. V.; Panter, K. S.; Wilch, T. I.; Dunbar, N. W.; McIntosh, W. C.; Blusztajn, J.; Tripati, A. K.; Bindeman, I. N.

2012-12-01

119

Ore Minerals  

NSDL National Science Digital Library

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

Dexter Perkins

120

Mineral Classification  

NSDL National Science Digital Library

This problem set challenges students to determine the chemical classification of minerals based on their chemical formula (provided). For oxygen-bearing minerals, students must also provide the valences of the various cations.

121

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

SciTech Connect

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

Sonnenthal, Eric; Xu, Tianfu; Bodvarrson, Gudmundur

2005-03-14

122

Mineral Properties  

NSDL National Science Digital Library

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

Mr. Wood

2010-11-14

123

Mineral Properties  

NSDL National Science Digital Library

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

Mineralogy 4 Kids

124

Mineral Chart  

MedlinePLUS

... Healthy Weight: Your Personal Plan Dealing With Anger Mineral Chart KidsHealth > Teens > Miscellaneous > Mineral Chart Print A A A Text Size Type ... sources of calcium. You'll also find this mineral in broccoli and dark green, leafy vegetables. Soy ...

125

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

PubMed

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 ? 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-? 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 ?m, 14 ?m, 9 ?m and 4 ?m respectively. PMID:25464145

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

2015-01-01

126

Mineral Identification  

NSDL National Science Digital Library

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

rmesser

2010-11-16

127

Identifying Minerals from Their Infra-red Spectra.  

ERIC Educational Resources Information Center

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

Paterson, W. G.

1986-01-01

128

Mineral Identification  

NSDL National Science Digital Library

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

John Pratte

129

Mineral Densities  

NSDL National Science Digital Library

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

130

Mineral Identification  

NSDL National Science Digital Library

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

Michael Passow

131

Mineral Hunt  

NSDL National Science Digital Library

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

Lawrence Hall of Science

2010-01-01

132

Mystery Minerals  

NSDL National Science Digital Library

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

Susan Morgan

133

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

SciTech Connect

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

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

2014-08-21

134

Secondary parkinsonism  

MedlinePLUS

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

135

Implant Materials Generate Different Peri-implant Inflammatory Factors: PEEK Promotes Fibrosis and Micro-textured Titanium Promotes Osteogenic Factors  

PubMed Central

Study Design An in vitro study examining factors produced by human mesenchymal stem cells (MSCs) on spine implant materials. Objective The aim of this study was to examine if the inflammatory microenvironment generated by cells on titanium-aluminum-vanadium (Ti-alloy, TiAlV) surfaces is affected by surface microtexture and if it differs from that generated on poly(ether ether ketone) (PEEK). Summary of Background Data Histologically, implants fabricated from PEEK have a fibrous connective tissue surface interface whereas Ti-alloy implants demonstrate close approximation with surrounding bone. Ti-alloy surfaces with complex micron/submicron scale roughness promote osteoblastic differentiation and foster a specific cellular environment that favors bone formation while PEEK favors fibrous tissue formation. Methods Human MSCs were cultured on tissue culture polystyrene (TCPS), PEEK, smooth TiAlV, or macro/micro/nano-textured rough TiAlV (mmnTiAlV) disks. Osteoblastic differentiation and secreted inflammatory interleukins were assessed after seven days. Fold changes in mRNAs for inflammation, necrosis, DNA damage, or apoptosis with respect to TCPS were measured by low-density PCR array. Data were analyzed by ANOVA followed by Student’s t-test with post hoc analysis. Results Cells on PEEK up-regulated mRNAs for chemokine ligand-2 (CCL2), interleukin (IL) 1?, IL6, IL8, and tumor necrosis factor (TNF). Cells grown on the mmnTiAlV had an 8-fold reduction in mRNAs for toll-like receptor-4. Cells grown on mmnTiAlV had reduced levels of pro-inflammatory interleukins. Cells on PEEK had higher mRNAs for factors strongly associated with cell death/apoptosis, while cells on mmnTiAlV exhibited reduced cytokine factor levels. All results were significant (p<0.05). Conclusions These results suggest that fibrous tissue around PEEK implants may be due to several factors: reduced osteoblastic differentiation of progenitor cells and production of an inflammatory environment that favors cell death via apoptosis and necrosis. Ti alloy surfaces with complex macro/micro/nano-scale roughness promote osteoblastic differentiation and foster a specific cellular environment that favors bone formation. PMID:25584952

Olivares-Navarrete, Rene; Hyzy, Sharon L.; Slosar, Paul J.; Schneider, Jennifer M.; Schwartz, Zvi; Boyan, Barbara D.

2015-01-01

136

Clay Minerals  

SciTech Connect

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

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

2014-03-14

137

Hydrothermal Experiments on Refractory Minerals Related to CAIs: Implications for Aqueous Alteration in Parent Bodies  

Microsoft Academic Search

Ca-Al-rich inclusions (CAIs) in carbonaceous chondrites contain secondary minerals such as nepheline, calcite and phyllosilicates [1]. There is no consensus on whether secondary minerals were produced by reaction with a solar nebular gas [2] or by aqueous alteration in parent bodies [3]. We performed hydrothermal experiments on several minerals common in CAIs to study aqueous alteration in parent bodies. Experiments:

K. Nomura; M. Miyamoto

1995-01-01

138

Industrial Minerals  

ERIC Educational Resources Information Center

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

Bradbury, James C.

1978-01-01

139

Defective Skeletal Mineralization in Pediatric CKD.  

PubMed

Although traditional diagnosis and treatment of renal osteodystrophy focused on changes in bone turnover, current data demonstrate that abnormalities in skeletal mineralization are also prevalent in pediatric chronic kidney disease (CKD) and likely contribute to skeletal morbidities that continue to plague this population. It is now clear that alterations in osteocyte biology, manifested by changes in osteocytic protein expression, occur in early CKD before abnormalities in traditional measures of mineral metabolism are apparent and may contribute to defective skeletal mineralization. Current treatment paradigms advocate the use of 1,25(OH)2vitamin D for the control of secondary hyperparathyroidism; however, these agents fail to correct defective skeletal mineralization and may exacerbate already altered osteocyte biology. Further studies are critically needed to identify the initial trigger for abnormalities of skeletal mineralization as well as the potential effects that current therapeutic options may have on osteocyte biology and bone mineralization. PMID:25638580

Wesseling-Perry, Katherine

2015-04-01

140

Vitamins and Minerals  

MedlinePLUS

... Select a Language: Fact Sheet 801 Vitamins and Minerals WHY ARE VITAMINS AND MINERALS IMPORTANT? WHAT ARE ANTIOXIDANTS? HOW MUCH DO I ... HARMFUL? FOR MORE INFORMATION WHY ARE VITAMINS AND MINERALS IMPORTANT? Vitamins and minerals are sometimes called micronutrients. ...

141

Vitamins and Minerals  

MedlinePLUS

... of a good thing? What Are Vitamins and Minerals? Vitamins and minerals make people's bodies work properly. ... of them each day. What Do Vitamins and Minerals Do? Vitamins and minerals boost the immune system, ...

142

Mineral bioprocessing  

SciTech Connect

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

Torma, A.E.

1993-05-01

143

Mineral Commodities  

NSDL National Science Digital Library

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

Dexter Perkins

144

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 ...

145

Rocks and Minerals  

NSDL National Science Digital Library

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

richrigby

2010-02-23

146

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

PubMed

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

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

2015-04-15

147

Minerals and Fossils  

NSDL National Science Digital Library

This site is dedicated to rock and mineral collecting. It contains information for worldwide mineral and fossil collectors with articles, mineral photos, videos, a search engine and free classified ads.

mineraltown.com

148

Mineral Sands Down Under  

NSDL National Science Digital Library

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

149

New Minerals and Science.  

ERIC Educational Resources Information Center

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)

Birch, William D.

1997-01-01

150

Vitamins and Minerals  

MedlinePLUS

... and Minerals Vitamins are organic substances (made by plants or animals), minerals are inorganic elements that come ... earth; soil and water and are absorbed by plants. Animals and humans absorb minerals from the plants ...

151

Properties of Minerals  

NSDL National Science Digital Library

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

Dexter Perkins

152

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.

153

MINERAL FACILITIES MAPPING PROJECT  

E-print Network

MINERAL FACILITIES MAPPING PROJECT Yadira Soto-Viruet Supervisor: David Menzie, Yolanda Fong-Sam Minerals Information Team (MIT) USGS Summer Internship 2009 U.S. Department of the Interior U.S. Geological Minerals Information Team (MIT): Annually reports on the minerals facilities of more than 180 countries

Gilbes, Fernando

154

Mineral Scavenger Hunt  

NSDL National Science Digital Library

In this activity, learners participate in a scavenger hunt, searching for and recognizing minerals and products that contain minerals. They make note of their finds on a Mineral Scavenger Hunt checklist. Learners search for the materials in their classroom, at home, or even in stores. This resource includes discussion questions to encourage learner reflection about how minerals play a role in daily life.

National Museum of Natural History

2010-01-01

155

Introduction to Minerals  

NSDL National Science Digital Library

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

156

Calculating a Mineral's Density  

NSDL National Science Digital Library

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

Andrea Distelhurst

2011-10-05

157

Earth's Mineral Evolution  

E-print Network

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

Downs, Robert T.

158

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

NASA Astrophysics Data System (ADS)

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

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

2011-02-01

159

Cooperative Secondary Authorization Recycling  

E-print Network

Cooperative Secondary Authorization Recycling Qiang Wei, Matei Ripeanu, Konstantin Beznosov responses 2. infer approximate responses Secondary Decision Point (SDP) Secondary Authorization Recycling Cooperative Secondary Authorization Recycling SDP SDP SDP Discovery Service each SDP serves only its own PEP

160

Physicochemical Controls on the Formation of Polynuclear Metal Complexes at Clay Mineral Surfaces  

E-print Network

Physicochemical Controls on the Formation of Polynuclear Metal Complexes at Clay Mineral Surfaces R. G. Ford Metal sorption to clay minerals may lead to the formation of secondary precipitates structurally similar to the mineral takovite. Saturation with respect to this phase is promoted, in part

Sparks, Donald L.

161

Minerals 4 Kids  

NSDL National Science Digital Library

Minerals 4 Kids contains four Web-based activities offered for K-12 Education by the Mineralogical Society of America (MSA). These activities are entitled: Minerals in Your House, Mineral Groups, Mineral Properties, and All About Crystals. Also included are links to Mineral Games, the Rock Cycle diagram that leads to descriptions of the three rock types, and Ask-A-Mineralogist that enables the user to submit a mineralogical question. Many of these activities are linked to other mineralogy-related Web sites. Minerals in Your House is designed to introduce the concept of how minerals are present in common household items found in the bedroom, bathroom, living room, and kitchen. Mineral Groups introduces mineral classification according to chemical composition. The learner can explore each of the seven major chemical groups and several minor chemical groups. Mineral Properties introduces learners to the physical properties of minerals such as hardness, cleavage, streak, color, luster, specific gravity, as well as other miscellaneous properties (i.e., magnetic, effervescence, striations, etc.). Mineral Properties, additionally, contains a five-step Mineral Identification process that uses the physical properties to narrow down a mineral's identity that, ultimately, leads to a Mineral Identification Chart. All About Crystals enables the learner to become familiar with symmetry, crystal symmetry, crystal chemistry, and crystal forms. This activity includes online 3-D models, an activity that enables the user to draw and explore symmetry patterns, a variety of detailed descriptions with figures, and an extensive vocabulary

Nancy McMillan

162

Indicators of aqueous alteration and thermal metamorphism on the CV parent body: Microtextures of a dark inclusion from Allende  

NASA Astrophysics Data System (ADS)

An unusual dark clast in the Allende CV3 chondrite (termed Allende-AF), which was previously interpreted as a primary aggregate formed in the solar nebula (Kurat et al., 1989; Palme et al., 1989), was re-examined. Our study reveals abundant evidence suggesting that it probably experienced extensive aqueous alteration and subsequent thermal metamorphism on the meteorite parent body. Allende-AF contains numerous rounded to oval-shaped inclusions embedded in a dark matrix. The inclusions, consisting predominantly of fine grains of Fe-rich olivine, have internal textures suggesting that they are pseudomorphs after chondrules. Several inclusions appear to be replaced CAIs. Veins filled with fibrous olivine grains occur abundantly in both inclusions and matrix; some veins (up to 4 mm in length) penetrate several inclusions, providing strong evidence that aqueous alteration occurred after accretion. The fibrous morphology of olivine in veins and inclusions suggests that the olivine was produced by dehydration and thermal transformation of phyllosilicate that had been formed by aqueous alteration. Olivine grains in the matrix contain numerous micro-inclusions of Fe?Ni sulfide, which were probably incorporated during transformation from phyllosilicate. Allende-AF is probably related to the fine-grained variety of dark inclusions reported from CV3 chondrites that has been described as the type containing abundant porous aggregates of Fe-rich olivine by Johnson et al. (1990). Many dark inclusions previously described appear to be similar in texture and mineralogy to Allende-AF, and probably experienced similar secondary process on the meteorite parent body. The wide variation in texture of dark inclusions can be explained by different degrees of aqueous alteration that preceded thermal metamorphism. The size distribution of chondrule pseudomorphs and the abundance of CAI pseudomorphs suggest that the precursor of Allende-AF is a CV type chondrite, probably Allende itself. Oxygen isotopic and chemical compositions are consistent with this interpretation. The CV parent body has been commonly thought to have escaped major secondary processing. However, Allende-AF provides evidence that extensive aqueous alteration and thermal metamorphism have occurred locally on the CV parent body.

Kojima, Tomoko; Tomeoka, Kazushige

1996-07-01

163

Mathematical Model for the Mineralization of Bone  

NASA Technical Reports Server (NTRS)

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

Martin, Bruce

1994-01-01

164

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

NASA Astrophysics Data System (ADS)

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

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

2013-12-01

165

Mineral Spectroscopy Server  

NSDL National Science Digital Library

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

George Rossman

166

Origin, Behavior and Texture of Clay Minerals in Mongolian Active Fault of Bogd and Comparison with SAFOD Fault Gouge  

NASA Astrophysics Data System (ADS)

Fault gouges are generally considered as the highly deformed zone corresponding to the localization of shear during seismic events. Clays are ubiquitous minerals in fault gouges but the origin is unclear. They can form as a result of break up of inherited phyllosilicates during faulting, or during co- or post- deformation events or even during interseismic creeping. In this study, we aim to characterize the origin and nature of the clay minerals, to observe the microtexture and preferred orientation of clay at various scales in order to understand the behavior of clay mineral in seismic faults. The investigation relied on x-ray powder patterns, SEM, TEM and high energy synchrotron x-ray diffraction. The major clay components are smectite, illite-smectite, illite-mica and kaolinite. Our observations suggest that the protolith and the fault rock of the Bogd and paleo-Bogd faults in Mongolia were highly altered by fluids. The fluid-rock interactions allows clay minerals to form and to precipitate kaolinite and smectite. Thus, newly formed clay minerals are heterogeneously distributed in the fault zone. The decrease of smectite component of the highly deformed samples suggests a dehydration process during deformation, leading to illite precipitation. From synchrotron diffraction images, volume fractions and preferred orientation were analyzed. Our analysis shows that texture strength of constituent clays is very weak ranging from 1.05 to 2.59 m.r.d., which is consistent with similar data from SAFOD fault gouge. The clays minerals of the Bogd fault favors the slip weakening behavior of the fault.

Wenk, H.; Buatier, M.; Chauvet, A.; Kanitpanyacharoen, W.

2010-12-01

167

Ohio Mineral Resources Management  

NSDL National Science Digital Library

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

168

Bartering for Minerals.  

ERIC Educational Resources Information Center

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

May, Kathie

2002-01-01

169

Sedimentary and Related Minerals  

NSDL National Science Digital Library

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

Dexter Perkins

170

Color in Minerals  

NSDL National Science Digital Library

Why do minerals have color? When is that color diagnostic, and when is it likely to fool you? Why is color important, and what can it tell us about the chemistry of minerals? This exercise will try to answer some of these questions, and to introduce students to the fascinating world of mineral spectroscopy, where chemistry meets mineralogy.

Darby Dyar

171

Minerals in our Environment  

NSDL National Science Digital Library

This downloadable poster (36 in. by 60 in.) describes how minerals are used in household substances and objects, listed by name, with numbers corresponding to locations in a typical house. For example, in the kitchen, appliances contain steel and copper, clay minerals are found in china, and table salt contains the mineral halite.

172

Mineral Properties Sheets  

NSDL National Science Digital Library

These sheets are designed to give students a framework for making observations of minerals in hand specimen and (for selected minerals) in thin section. I place most of the emphasis on the distinguishing properties, rather than requiring an exhaustive list. Students use hand specimen observation, thin section observation (for selected minerals) and references to complete the forms.

Dave Hirsch

173

Metamorphic Rocks and Minerals  

NSDL National Science Digital Library

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

Dexter Perkins

174

Uranium mineralization in southern Victoria Land, Antarctica  

SciTech Connect

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

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

1986-01-01

175

American Strategic Minerals  

SciTech Connect

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

Mangone, G.

1984-01-01

176

Minerals Under the Microscope  

NSDL National Science Digital Library

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

Browning, Paul

177

Weathering of Minerals  

NSDL National Science Digital Library

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

Wendy Van Norden

178

USGS: Mineral Resources Program  

NSDL National Science Digital Library

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

179

Mineral Classification Exercise  

NSDL National Science Digital Library

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

Dexter Perkins

180

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.

181

Minerals by Chemical Composition  

NSDL National Science Digital Library

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

182

Primary and Secondary Sources  

NSDL National Science Digital Library

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

Albion Middle School Library--Mrs. Bates

2010-01-23

183

Chemical differences between minerals from mineralizing and barren intrusions from some North American porphyry copper deposits  

NASA Astrophysics Data System (ADS)

Major-element analyses (by electron microprobe) and copper contents (by ion-probe) are reported for primary biotite, amphibole, magnetite, pyroxene, ilmenite, sphene and secondary biotite from intrusive rocks from mineralizing and barren stocks. The districts studied include Christmas, Globe-Miami, Sierrita and Tombstone, in Arizona; Bingham and Alta, Utah; Ely, Nevada; and Brenda, British Columbia. Amphiboles from barren rocks are relatively iron-rich and display only minor compositional variation. In contrast, amphiboles from mineralizing rocks span the range from magnesio-hornblende to actinolite, commonly even within one grain. Barren intrusions (type B) that are temporally distinct from mineralizing intrusions, and barren intrusions outside areas of known mineralization have higher Cu contents in their constituent minerals than do mineralizing intrusions. Barren intrusions (type A) that are deep-level temporal equivalents of Cu-bearing porphyritic rocks are depleted in copper. This suggests that copper is abstracted from not only the apical portions of porphyries but from parts of the deeper parent intrusions. The Cu contents of biotites (av. 23 ppm) and magnetites (97 ppm) from barren type B intrusions contrast with those from mineralizing intrusions, with biotites containing 7 ppm Cu and magnetites 3 ppm Cu. Primary amphiboles from all intrusive rock types have low copper contents, typically 2 to 5 ppm. In the continental North American deposits, the amount of copper available by liberation from or non-incorporation into amphibole, biotite and magnetite during magmatic crystallization or the early hydrothermal stage is low, perhaps too low to be the sole source of copper mineralization, unless copper is abstracted from large volumes (˜ 100 km3) of rock. These results contrast with a study of the island-arc porphyry copper at Koloula, Guadalcanal, where it was argued that sufficient copper for mineralization could have been abstracted from relatively small volumes of host rocks that originally contained as much Cu as the contemporaneous barren rock types.

Hendry, D. A. F.; Chivas, A. R.; Long, J. V. P.; Reed, S. J. B.

1985-05-01

184

Carbon dioxide sequestration by mineral carbonation  

SciTech Connect

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

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

2003-11-01

185

Ion beam microtexturing of surfaces  

NASA Technical Reports Server (NTRS)

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

Robinson, R. S.

1981-01-01

186

PSC 424: Rocks and Minerals  

NSDL National Science Digital Library

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

Ms. Graham

2011-10-13

187

Digging into Minnesota Minerals.  

ERIC Educational Resources Information Center

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

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

188

Mineral Image Index  

NSDL National Science Digital Library

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

189

Minerals Yearbook 1989: Boron  

Microsoft Academic Search

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

Lyday

1990-01-01

190

Rocks & Mineral Solitaire  

NSDL National Science Digital Library

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

Andrea J. Catania

191

The Miner's Canary  

ERIC Educational Resources Information Center

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

Guinier, Lani

2005-01-01

192

Rocks and Minerals  

NSDL National Science Digital Library

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

193

Minerals in Our Environment  

NSDL National Science Digital Library

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

Frank, Dave

194

Rocks and Minerals  

NSDL National Science Digital Library

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

195

Vitamins, Minerals, and Mood  

ERIC Educational Resources Information Center

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

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

2007-01-01

196

Atoms and Minerals  

NSDL National Science Digital Library

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

Timothy Heaton

197

Vitamin and mineral requirements  

E-print Network

Vitamin and mineral requirements in human nutrition Second edition Please go to the Table and mineral requirements in human nutrition : report of a joint FAO/WHO expert consultation, Bangkok, Thailand REQUIREMENTS IN HUMAN NUTRITION iv 2.2.4 Risk factors 22 2.2.5 Morbidity and mortality 23 2.3 Units

Laughlin, Robert B.

198

Minerals, Crystals and Gems  

NSDL National Science Digital Library

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

199

USGS: Energy & Minerals  

NSDL National Science Digital Library

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

2013-06-20

200

Underground mineral extraction  

NASA Technical Reports Server (NTRS)

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

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

1980-01-01

201

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

SciTech Connect

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

NONE

1993-12-31

202

Comparison of treatments for mild secondary hyperparathyroidism in hemodialysis patients  

Microsoft Academic Search

Comparison of treatments for mild secondary hyperparathyroidism in hemodialysis patients.BackgroundIn the management of patients with mild secondary hyperparathyroidism, it is not known whether calcium supplementation alone is sufficient to correct abnormalities in bone and mineral metabolism or if calcitriol is needed in either physiologic oral or intravenous pharmacologic doses.MethodsThis was a 40-week prospective nonmasked trial of 52 patients [parathyroid hormone

Olafur S Indridason; L Darryl Quarles

2000-01-01

203

Teaching with Secondary Data.  

ERIC Educational Resources Information Center

Presents a general overview of the use of secondary data in teaching sociology on the college level. Topics discussed include potential for additional applications, sources which constitute secondary data, reasons for using secondary data in the classroom, information about computing, and potential problems. (Author/DB)

Sobol, Jeff

1981-01-01

204

Digging into Minnesota Minerals  

NSDL National Science Digital Library

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

205

Exploitation of Antarctic minerals  

SciTech Connect

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

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

1987-01-01

206

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...

207

Lactation Among Adolescent Mothers and Subsequent Bone Mineral Density  

Microsoft Academic Search

Objective: To investigate the association of breastfeed- ing during adolescence with bone mineral density (BMD) during young adulthood. Methods: Secondary analysis of data from the Na- tional Health and Nutrition Examination Survey III, a na- tionally representative cross-sectional survey con- ducted from 1988 through 1994, was performed. The BMDs for 5 regions of the proximal femur as measured by dual

Caroline J. Chantry; Peggy Auinger; Robert S. Byrd

2004-01-01

208

36 CFR 293.14 - Mineral leases and mineral permits.  

Code of Federal Regulations, 2010 CFR

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

2010-07-01

209

Overview of Minerals  

MedlinePLUS

... body's cells. The body needs large quantities of calcium, chloride, magnesium, phosphate, potassium, and sodium. These minerals are ... Recommended Dietary Allowance for Adults Safe Upper Limit ... Chloride Salt, beef, pork, sardines, cheese, green olives, corn ...

210

Herbs, Vitamins, and Minerals  

MedlinePLUS

... the temperate and subarctic regions of Asia. Cesium Chloride Cesium chloride is the salt form of the element cesium. ... amino acids, and trace minerals such as selenium, calcium, magnesium, zinc, and copper. Peppermint Peppermint is a ...

211

Minerals and mine drainage  

SciTech Connect

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

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

1995-06-01

212

Minerals and mine drainage  

SciTech Connect

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

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

1996-11-01

213

Private Mineral Gallery Walk  

NSDL National Science Digital Library

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

Dexter Perkins

214

Gems and Gem Minerals  

NSDL National Science Digital Library

This is the homepage of a Gem and Minerals class at the University of Texas. The course objectives are to explore the following topics: what are gems and minerals, methods of identification, physical and optical propoerties, crystallography and optics, lapidary arts, the geology of major gem localities, and the value of gems. The site offers access to the course syllabus, handouts, exams with interactive answer-checking, and reference material for common gems.

215

Ice is a Mineral  

NSDL National Science Digital Library

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

2012-08-03

216

Mineral prospecting manual  

SciTech Connect

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

Chaussier, J.B.; Morer, J.

1986-01-01

217

The mineral economy of Brazil--Economia mineral do Brasil  

USGS Publications Warehouse

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

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

1999-01-01

218

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

SciTech Connect

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

NONE

1993-12-31

219

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

SciTech Connect

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

NONE

1994-12-31

220

The Mineral and Gemstone Kingdom  

NSDL National Science Digital Library

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

221

Measuring the Hardness of Minerals  

ERIC Educational Resources Information Center

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

Bushby, Jessica

2005-01-01

222

Mineral impurities in coal combustion  

Microsoft Academic Search

This article discusses the many and varied problems associated with coal combustion and suggests remedial measures to assist in producing electrical energy from coal more efficiently. Contents include: influence of coal mineral matter on boiler design; mineral impurities in coal; quality of coal utilized in power stations; coal grinding, abrasive fuel minerals and plant wear; particulates silicate minerals in boiler

Raask

1985-01-01

223

Isotopic bone mineralization rates in maintenance dialysis patients  

SciTech Connect

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

Cochran, M.; Stephens, E.

1983-09-01

224

DIAMOND SECONDARY EMITTER  

SciTech Connect

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

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

2005-10-09

225

The JMU Mineral Museum - Observing Physical Properties of Minerals  

NSDL National Science Digital Library

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

Cynthia A. Kearns

226

Minerals Yearbook 1989: Boron  

SciTech Connect

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

Lyday, P.A.

1990-08-01

227

Microbially mediated mineral carbonation  

NASA Astrophysics Data System (ADS)

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

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

2010-12-01

228

Study on comprehensive utilization of secondary resources  

SciTech Connect

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

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

1995-12-31

229

The Physical Characteristics of Minerals  

NSDL National Science Digital Library

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

230

Rocks and Minerals Of Kentucky  

NSDL National Science Digital Library

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

231

Oxidants from Pulverized Minerals  

NASA Astrophysics Data System (ADS)

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

Martel, L. M. V.

2007-06-01

232

Identification of Minerals  

ERIC Educational Resources Information Center

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…

Allison, Diane

2005-01-01

233

Clay Mineral: Radiological Characterization  

NASA Astrophysics Data System (ADS)

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

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

2008-08-01

234

Mineral mining installation  

Microsoft Academic Search

A mineral mining installation comprises a mechanical mining machine (such as a plough or a shearer) and a hydraulic winning machine. The hydraulic winning machine has a plurality of high pressure nozzles and a high-pressure pump for supplying the nozzles with high-pressure water (or other hydraulic fluid). Means are provided for driving each of the two winning machines independently of

K. Beckmann; H. Grisebach

1981-01-01

235

Introduction to Mineral Equilibria  

NSDL National Science Digital Library

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

Dexter Perkins

236

Engineering and Mineral Resources  

E-print Network

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

Mohaghegh, Shahab

237

Energy and Mineral Resources  

NSDL National Science Digital Library

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

Timothy Heaton

238

Fossils and Minerals  

NSDL National Science Digital Library

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

Inc. Black Hills Institute of Geological Research

239

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...

240

Lithium inhibition of bone mineralization and osteoid formation.  

PubMed Central

Lithium chloride administration to growing rats, which resulted in circulating lithium levels of 1.4 meq/liter, was attended by significant suppression of bone mineralization and organic matrix synthesis as assessed by tetracycline labeling and histological quantitation of osteoid, respectively. These effects of lithium were not associated with changes in animal behavior, nor were there any significant differences in blood levels of calcium, phosphorus, alkaline phosphatase, creatinine, pH, or parathyroid hormone. The data suggest that lithium inhibition of bone mineralization is secondary to suppression of osteoid formation. Images PMID:659622

Baran, D T; Schwartz, M P; Bergfeld, M A; Teitelbaum, S L; Slatopolsky, E; Avioli, L V

1978-01-01

241

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

PubMed

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

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

2008-01-01

242

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

PubMed Central

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

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

2008-01-01

243

Alphabetical Listing of Mineral Species  

NSDL National Science Digital Library

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

244

Vitamins and Minerals during Pregnancy  

MedlinePLUS

... added to your dashboard . Vitamins and minerals during pregnancy Your body uses vitamins, minerals and other nutrients ... certain foods. Which nutrients are most important during pregnancy? All nutrients are important, but these six play ...

245

Private Mineral Project - Part 1  

NSDL National Science Digital Library

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

Dexter Perkins

246

RON MINER MEMORIAL BIOENGINEERING SCHOLARSHIP The Ron Miner Memorial Scholarship honors the memory of J. Ronald Miner, an  

E-print Network

RON MINER MEMORIAL BIOENGINEERING SCHOLARSHIP The Ron Miner Memorial Scholarship honors the memory from the Ron Miner Memorial Scholarship which resides with the OSU Foundation. The name & Ecological Engineering. DONOR Ron Miner Memorial Bioengineering Scholarship Fund ELIGIBILITY REQUIREMENTS

Tullos, Desiree

247

Modeling gas formation and mineral precipitation in a granular iron column.  

PubMed

In granular iron permeable reactive barriers (PRBs), hydrogen gas formation, entrapment and release of gas bubbles, and secondary mineral precipitation have been known to affect the permeability and reactivity. The multicomponent reactive transport model MIN3P was enhanced to couple gas formation and release, secondary mineral precipitation, and the effects of these processes on hydraulic properties and iron reactivity. The enhanced model was applied to a granular iron column, which was studied for the treatment of trichloroethene (TCE) in the presence of dissolved CaCO(3). The simulation reasonably reproduced trends in gas formation, secondary mineral precipitation, permeability changes, and reactivity changes observed over time. The simulation showed that the accumulation of secondary minerals reduced the reactivity of the granular iron over time, which in turn decreased the rate of mineral accumulation, and also resulted in a gradual decrease in gas formation over time. This study provides a quantitative assessment of the evolving nature of geochemistry and permeability, resulting from coupled processes of gas formation and mineral precipitation, which leads to a better understanding of the processes controlling the granular iron reactivity, and represents an improved method for incorporating these factors into the design of granular iron PRBs. PMID:22540940

Jeen, Sung-Wook; Amos, Richard T; Blowes, David W

2012-06-19

248

Mineral Transformations by Mycorrhizal Fungi  

Microsoft Academic Search

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

Elena Martino; Silvia Perotto

2010-01-01

249

Mineral Properties -- Learning through Experience  

NSDL National Science Digital Library

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

Katryn Wiese

250

Institute for Mineral and Energy  

E-print Network

Institute for Mineral and Energy Resources Answering Global Resource and Energy Challenges #12;Answering Global Resource and Energy Challenges 2 Vision The vision of the Institute for Mineral and Energy Resources (IMER) is to enable the efficient and sustainable use and development of the world's mineral

251

76 FR 6110 - Conflict Minerals  

Federal Register 2010, 2011, 2012, 2013, 2014

...File No. S7-40-10] RIN 3235-AK84 Conflict Minerals AGENCY: Securities and Exchange...would require any such issuer for which conflict minerals are necessary to the functionality...body of its annual report whether its conflict minerals originated in the...

2011-02-03

252

Kidney bone disease and mortality in CKD: revisiting the role of vitamin D, calcimimetics, alkaline phosphatase, and minerals  

Microsoft Academic Search

Recent evidence suggests that the traditional syndromes known as renal osteodystrophy, secondary hyperparathyroidism, and vitamin D deficiency are related to mortality in persons with moderate to advanced chronic kidney disease (CKD). The so-called ‘kidney bone disease’, also known as ‘mineral and bone disorders’, is defined to include bone disorders, mineral disarrays, and vascular calcification. We have identified 14 common and

Kamyar Kalantar-Zadeh; Anuja Shah; Uyen Duong; Rulin C Hechter; Ramanath Dukkipati; Csaba P Kovesdy

2010-01-01

253

Secondary and backscattered electron imaging of weathered chromian spinel.  

PubMed

Secondary (SE) and backscattered electron (BSE) imaging as well as x-ray microanalysis have demonstrated that the weathering of chromian spinel occurs as a progressive form of alteration. Numerous chemical discriminant analysis methods based on the composition of chromian spinel are used to locate valuable deposits of minerals. These methods will be misleading if the correct interpretation of the weathering of chromian spinel and the subsequent pattern of changes in its mineral chemistry are not properly assessed using scanning electron microscopy. This assessment is vital in understanding the geological processes involved and the economic potential of any indicated deposit. Minerals such as chromian spinel, pyrope garnet, and picroilmenite are considered to be highly resistant to weathering and abrasion and are therefore useful in the search for associated valuable deposits of diamond, nickel, platinum, and gold. Known as indicator minerals, they are usually present in relatively large concentrations compared with the target mineral (e.g., diamond) and form large and often subtle dispersion anomalies adjacent to the deposit. Chromian spinel has long been regarded as a stable indicator mineral; however, detailed SE and BSE imaging indicates that many of the chromian spinels that are routinely examined using scanning electron microscopes (SEM) and microprobes are extensively altered. Secondary electron and BSE imaging of weathered chromian spinel in a normal SEM provides valuable data on the form and chemical style of the alteration. Secondary electron imaging of weathered chromian spinel in the environmental SEM (ESEM) not only enhances the difference in atomic number between unaltered and altered areas but also allows high-resolution imaging of these very fine replacement textures. PMID:15536980

Pooley, Gregory D

2004-01-01

254

43 CFR 3816.1 - Mineral locations.  

Code of Federal Regulations, 2013 CFR

... 2013-10-01 2013-10-01 false Mineral locations. 3816.1 Section 3816.1...LAND MANAGEMENT, DEPARTMENT OF THE INTERIOR MINERALS MANAGEMENT (3000) LANDS AND MINERALS SUBJECT TO LOCATION Mineral Locations...

2013-10-01

255

43 CFR 3815.1 - Mineral locations.  

Code of Federal Regulations, 2011 CFR

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

2011-10-01

256

43 CFR 3815.1 - Mineral locations.  

Code of Federal Regulations, 2013 CFR

... 2013-10-01 2013-10-01 false Mineral locations. 3815.1 Section 3815.1...LAND MANAGEMENT, DEPARTMENT OF THE INTERIOR MINERALS MANAGEMENT (3000) LANDS AND MINERALS SUBJECT TO LOCATION Mineral Locations...

2013-10-01

257

43 CFR 3815.1 - Mineral locations.  

Code of Federal Regulations, 2014 CFR

... 2014-10-01 2014-10-01 false Mineral locations. 3815.1 Section 3815.1...LAND MANAGEMENT, DEPARTMENT OF THE INTERIOR MINERALS MANAGEMENT (3000) LANDS AND MINERALS SUBJECT TO LOCATION Mineral Locations...

2014-10-01

258

43 CFR 3816.1 - Mineral locations.  

Code of Federal Regulations, 2012 CFR

... 2012-10-01 2012-10-01 false Mineral locations. 3816.1 Section 3816.1...LAND MANAGEMENT, DEPARTMENT OF THE INTERIOR MINERALS MANAGEMENT (3000) LANDS AND MINERALS SUBJECT TO LOCATION Mineral Locations...

2012-10-01

259

43 CFR 3816.1 - Mineral locations.  

Code of Federal Regulations, 2011 CFR

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

2011-10-01

260

43 CFR 3815.1 - Mineral locations.  

Code of Federal Regulations, 2012 CFR

... 2012-10-01 2012-10-01 false Mineral locations. 3815.1 Section 3815.1...LAND MANAGEMENT, DEPARTMENT OF THE INTERIOR MINERALS MANAGEMENT (3000) LANDS AND MINERALS SUBJECT TO LOCATION Mineral Locations...

2012-10-01

261

43 CFR 3816.1 - Mineral locations.  

Code of Federal Regulations, 2014 CFR

... 2014-10-01 2014-10-01 false Mineral locations. 3816.1 Section 3816.1...LAND MANAGEMENT, DEPARTMENT OF THE INTERIOR MINERALS MANAGEMENT (3000) LANDS AND MINERALS SUBJECT TO LOCATION Mineral Locations...

2014-10-01

262

Are colors Secondary Qualities?  

E-print Network

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

Byrne, Alex

263

Neuropathy secondary to drugs  

MedlinePLUS

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

264

Energy and mineral resource systems: An introduction  

SciTech Connect

This book provides a welcome approach to understanding the fundamental role that energy and mineral resources play in the affairs of nations and individuals. Chapter 1 presents background material on energy in the human environment. Chapter 2 deals with historical changes in predominant energy sources, energy efficiencies based on the first and second laws of thermodynamics, potential utility of secondary energy sources, and the distribution of energy reserves among political and economic units. Chapter 3 discusses the methods and pitfalls of projecting future energy demand and technologies of alternative energy sources. Chapter 4 analyzes the projected growth-decline patterns in world oil and coal production, viability of alternative sources, and three possible future energy scenarios. Chapter 5 concludes with methods of energy flow analysis and further discussion on future energy scenarios. Chapter 6 begins by establishing several basic points about mineral resource systems then proceeds with a discussion of consumption-production patterns of metals. Chapter 7 presents estimates of global metal stocks, outlines factors determining metal demand, and examines metal import-export balances and resource potential for Australia and the Pacific Basin region. Chapter 8 highlights current issues that affect the mineral resource industry. Chapter 9 recounts the historical changes in exploration approaches, from prospecting to the utilization of genetic models, specialist teams, and regional geochemical and geophysical surveys. Chapter 10 assesses the implications of the previously noted trends in metal consumption and new technologies and concludes that future energy and mineral resource system evaluations will be according to new strategems and economic criteria.

Tapp, B.A.; Watkins, J.R.

1990-01-01

265

Minerals and mine drainage  

SciTech Connect

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

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

2009-09-15

266

Mineral mining installation  

SciTech Connect

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

Beckmann, K.; Grisebach, H.

1981-02-17

267

Silicosis in barium miners.  

PubMed Central

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

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

1986-01-01

268

Mineral bridges in nacre.  

PubMed

We confirm with high-resolution techniques the existence of mineral bridges between superposed nacre tablets. In the towered nacre of both gastropods and the cephalopod Nautilus there are large bridges aligned along the tower axes, corresponding to gaps (150-200nm) in the interlamellar membranes. Gaps are produced by the interaction of the nascent tablets with a surface membrane that covers the nacre compartment. In the terraced nacre of bivalves bridges associated with elongated gaps in the interlamellar membrane (>100nm) have mainly been found at or close to the edges of superposed parental tablets. To explain this placement, we hypothesize that the interlamellar membrane breaks due to differences in osmotic pressure across it when the interlamellar space below becomes reduced at an advanced stage of calcification. In no cases are the minor connections between superimposed tablets (<60nm), earlier reported to be mineral bridges, found to be such. PMID:21982842

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

2011-12-01

269

Magnetic birefringence of minerals.  

PubMed

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

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

2005-01-15

270

Bacteriophage secondary infection.  

PubMed

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

Abedon, Stephen T

2015-02-01

271

Secondary metabolism in cannabis  

Microsoft Academic Search

Cannabis sativa L. is an annual dioecious plant from Central Asia. Cannabinoids, flavonoids, stilbenoids, terpenoids, alkaloids and lignans\\u000a are some of the secondary metabolites present in C. sativa. Earlier reviews were focused on isolation and identification of more than 480 chemical compounds; this review deals with\\u000a the biosynthesis of the secondary metabolites present in this plant. Cannabinoid biosynthesis and some

Isvett Josefina Flores-Sanchez; Robert Verpoorte

2008-01-01

272

Secondary Metabolites of Basidiomycetes  

Microsoft Academic Search

\\u000a Basidiomycetes, a major class of higher fungi adapted to many different climates, habitats, and substrates have developed\\u000a a rich and very diverse secondary metabolism. Its products differ in biogenetic origin and structure remarkably from the metabolites\\u000a of ascomycetes or other prolific producers of secondary metabolites like actinomycetes or myxobacteria. There are, however,\\u000a some similarities to the products of plants, especially

Anja Schüffler; Timm Anke

273

Mineralization by nanobacteria  

Microsoft Academic Search

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

E. Olavi Kajander; Michael Bjorklund; Neva Ciftcioglu

1998-01-01

274

Mineral Physics Activity Sets  

NSDL National Science Digital Library

These assignment sets are designed for a 500-level course in mineral physics for geoscience majors. The activities/problem sets are derived from a course at the University of Washington. They include topics such as Earth models, lattices, x-rays, thermodynamics, elasticity, and lattice vibrations/pressure. Some of the activities elicit the use of MATLAB programming. Supporting materials and spreadsheets in addition to links to class notes and handouts are also provided.

Michael Brown

275

The Clay Minerals Society  

NSDL National Science Digital Library

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

276

Clay Mineral: Radiological Characterization  

SciTech Connect

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

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

2008-08-07

277

Exploring Bone Mineral Density  

NSDL National Science Digital Library

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

VU Bioengineering RET Program,

278

Secondary psychoses: an update  

PubMed Central

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

Keshavan, Matcheri S; Kaneko, Yoshio

2013-01-01

279

Calcite: The multiuse mineral  

SciTech Connect

If people were told that a newly discovered mineral polarizes light, provides a raw material for sculptors, diminishes the danger of hip breakage, makes long-lasting foundations for buildings, reduces pollution at power plants, serves as a soil conditioner and water purifier, and saves life on earth from suffocation, they might be inclined to say either {open_quotes}Ain`t science wonderful!{close_quotes} or {open_quotes}Come on, now!{close_quotes} Luckily for humanity, such a mineral has been around for a billion years or so, and things would not be quite the same without it. It is calcite (CaCO{sub 3}) which in its most common natural form is known as limestone. Hubbard and Ericksen (1973) reported, {open_quotes}Limestone and dolomite [which is calcium or magnesium carbonate and bears the name of the Dolomites of northern Italy], commonly referred to as the carbonate rocks, are among the world`s most widely used mineral commodities and are essential to modern industrial society.{close_quotes}

Paschall, R.

1994-11-01

280

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

NASA Astrophysics Data System (ADS)

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

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

2014-09-01

281

Electron microprobe mineral analysis guide  

NASA Technical Reports Server (NTRS)

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

Brown, R. W.

1980-01-01

282

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

NASA Technical Reports Server (NTRS)

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

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

2007-01-01

283

Physical and stable-isotope evidence for formation of secondary calcite and silica in the unsaturated zone, Yucca Mountain, Nevada  

Microsoft Academic Search

Calcite and silica form coatings on fracture footwalls and cavity floors in the welded tuffs at Yucca Mountain, the potential site of a high-level radioactive waste repository. These secondary mineral deposits are heterogeneously distributed in the unsaturated zone (UZ) with fewer than 10% of possible depositional sites mineralized. The paragenetic sequence, compiled from deposits throughout the UZ, consists of an

Joseph F. Whelan; James B. Paces; Zell E. Peterman

2002-01-01

284

Bone and Mineral Metabolism in Patients with Primary Aldosteronism  

PubMed Central

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

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

2014-01-01

285

The mineral and rock resources of Ghana  

SciTech Connect

This book presents in this publication information on the mineral and rock resources of Ghana. Minerals that do not exist in Ghana in commercial quantities are also treated and mention is made where they have been found in Ghana. Topics covered include the following: the importance of minerals; the geography, physiography, geology and geohydrology of Ghana; metallic minerals; non-metallic minerals; bulk construction materials; radioactive minerals; petroleum and other fossil fuels; minor minerals; minerals in concentrates; the Ghana Geological Survey and mineral exploration and exploitation in Ghana; and legislation affecting mineral concessions and the mining industry.

Kesse, G.O.

1985-01-01

286

Rocks and Minerals  

NSDL National Science Digital Library

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

287

Influence of abiotic stress signals on secondary metabolites in plants  

PubMed Central

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

Ramakrishna, Akula; Ravishankar, Gokare Aswathanarayana

2011-01-01

288

Spectroscopic characterization of manganese minerals.  

PubMed

Manganese minerals ardenite, alleghanyite and leucopoenicite originated from Madhya Pradesh, India, Nagano prefecture Japan, Sussex Country and Parker Shaft Franklin, Sussex Country, New Jersey respectively are used in the present work. In these minerals manganese is the major constituent and iron if present is in traces only. An EPR study of on all of the above samples confirms the presence of Mn(II) with g around 2.0. Optical absorption spectrum of the mineral alleghanyite indicates that Mn(II) is present in two different octahedral sites and in leucophoenicite Mn(II) is also in octahedral geometry. Ardenite mineral gives only a few Mn(II) bands. NIR results of the minerals ardenite, leucophoenicite and alleghanyite are due to hydroxyl and silicate anions which confirming the formulae of the minerals. PMID:23995604

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

2014-01-01

289

Microelectrophoresis of selected mineral particles  

NASA Technical Reports Server (NTRS)

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

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

1982-01-01

290

MICROBIOLOGY: How Bacteria Respire Minerals  

NSDL National Science Digital Library

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

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

2001-05-18

291

Mineral Time Capsules on Mars?  

NASA Technical Reports Server (NTRS)

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

Schirber, Michael

2006-01-01

292

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

NASA Astrophysics Data System (ADS)

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

Jordan, Gyozo

2009-07-01

293

Rocks and Minerals Slide Show  

NSDL National Science Digital Library

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

294

RUSSIAN FOR SECONDARY SCHOOLS.  

ERIC Educational Resources Information Center

THE NEW YORK STATE SYLLABUS FOR RUSSIAN IN SECONDARY SCHOOLS FOLLOWS THE SAME FORMAT AS THOSE FOR FRENCH, GERMAN, AND SPANISH, AND FOR COMPLETE TEXT, INCLUDING GENERAL SECTIONS ON TEACHING LANGUAGES, THE READER MUST REFER TO ONE OF THOSE THREE BOOKS. THIS GUIDE DELINEATES THE AIMS, TECHNIQUES, CONTENT, AND SCOPE OF RUSSIAN INSTRUCTION FOR A 6-YEAR…

New York State Education Dept., Albany.

295

Dynamics of secondary forests  

Microsoft Academic Search

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

Breugel van M

2007-01-01

296

[Secondary bronchogenic pulmonary hydatidosis].  

PubMed

Secondary bronchogenic hydatid disease is a rare and little known complication of primary hydatid cyst of the lung, which is even refuted by some authors. We report 7 cases of secondary bronchogenic hydatid after surgical cure of a hydatid cyst which had ruptured into the bronchi, while the last case concerned a young girl who was treated by corticosteroids for rheumatoid arthritis and who developed secondary bronchogenic hydatid from a cyst rupturing into the bronchi in the absence of surgery. Hydatid dissemination was ipsilateral to the primary cyst in 5 cases, contralateral in one case and bilateral in one case. Five patients underwent radical surgery. The patient with bilateral dissemination was operated on one side and a large number of residual cysts were eliminated by vomica, as for the last patient; these two patients are still under surveillance. The operation and general anaesthesia played a predisposing role in the pathogenesis of this complication and inhibition of immune mechanisms could also play a role. Prevention is necessary when treating a hydatid cyst of the lung which has ruptured into the bronchi. Treatment is surgical, bearing in mind that a large number of secondary cysts can be eliminated by vomica or may involute spontaneously. PMID:1303609

Kilani, T; Horchani, H; Daoues, A

1992-01-01

297

[Secondary bronchogenic pulmonary hydatidosis].  

PubMed

Secondary bronchogenic hydatid disease is a rare and little known complication of primary hydatid cyst of the lung, which is even refuted by some authors. We report 7 cases of secondary bronchogenic hydatid after surgical cure of a hydatid cyst which had ruptured into the bronchi, while the last case concerned a young girl who was treated by corticosteroids for rheumatoid arthritis and who developed secondary bronchogenic hydatid from a cyst rupturing into the bronchi in the absence of surgery. Hydatid dissemination was ipsilateral to the primary cyst in 5 cases, controlateral in one case and bilateral in one case. Five patients underwent radical surgery. The patient with bilateral dissemination was operated on one side and a large number of residual cysts were eliminated by vomica, as for the last patient; these two patients are still under surveillance. The operation and general anaesthesia played a predisposing role in the pathogenesis of this complication and inhibition of immune mechanisms could also play a role. Prevention is necessary when treating a hydatid cyst of the lung which has ruptured into the bronchi. Treatment is surgical, bearing in mind that a large number of secondary cysts can be eliminated by vomica or may involute spontaneously. PMID:1605539

Kilani, T; Horchani, H; Daoues, A

1992-01-01

298

Aircraft Electric Secondary Power  

NASA Technical Reports Server (NTRS)

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

1983-01-01

299

Secondary Services in Physics.  

ERIC Educational Resources Information Center

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

Cooper, Marianne; Terry, Edward

300

Diagenesis and clay mineral formation at Gale Crater, Mars  

NASA Astrophysics Data System (ADS)

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.

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

2015-01-01

301

Electrokinetic properties of soil minerals and soils modified with polyelectrolytes  

NASA Astrophysics Data System (ADS)

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

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

2014-07-01

302

Secondary impact hazard assessment  

NASA Technical Reports Server (NTRS)

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

1986-01-01

303

Mineral Detector for Igneous Rocks  

NASA Astrophysics Data System (ADS)

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

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

2010-12-01

304

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

PubMed

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

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

2011-09-15

305

Protein- mediated enamel mineralization  

PubMed Central

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

Moradian-Oldak, Janet

2012-01-01

306

Mineralization by nanobacteria  

NASA Astrophysics Data System (ADS)

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

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

1998-07-01

307

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).

308

Pneumoconiosis of shale miners.  

PubMed Central

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

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

1981-01-01

309

Minerals arranged by the Strunz Classification System  

NSDL National Science Digital Library

This directory provides a listing of mineral species under the Strunz system, a chemical-structural system for classifying minerals. Clicking on each class (elements, sulfides, oxides/hydroxides, etc.) provides a listing of all minerals that conform to that class. Each mineral name is a link aditional information on the mineral.

310

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

PubMed

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: coarse-silty, mixed, superactive, mesic Xeric Haplocambids) 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 on 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. PMID:15998863

Um, Wooyong; Serne, R Jeffrey; Yabusaki, Steven B; Owen, Antoinette T

2005-01-01

311

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

Code of Federal Regulations, 2012 CFR

... 2012-10-01 2012-10-01 false Minerals soluble in water; brines; minerals taken in solution. 3594.5 Section 3594...LAND MANAGEMENT, DEPARTMENT OF THE INTERIOR MINERALS MANAGEMENT (3000) SOLID MINERALS...

2012-10-01

312

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

Code of Federal Regulations, 2011 CFR

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

2011-10-01

313

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

Code of Federal Regulations, 2014 CFR

... 2014-10-01 false Management of Federal minerals from reserved mineral estates. 3000.8 Section 3000.8 Public...OF LAND MANAGEMENT, DEPARTMENT OF THE INTERIOR MINERALS MANAGEMENT (3000) MINERALS MANAGEMENT:...

2014-10-01

314

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

Code of Federal Regulations, 2013 CFR

... 2013-10-01 2013-10-01 false Minerals soluble in water; brines; minerals taken in solution. 3594.5 Section 3594...LAND MANAGEMENT, DEPARTMENT OF THE INTERIOR MINERALS MANAGEMENT (3000) SOLID MINERALS...

2013-10-01

315

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

Code of Federal Regulations, 2011 CFR

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

2011-10-01

316

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

Code of Federal Regulations, 2013 CFR

... 2013-10-01 false Management of Federal minerals from reserved mineral estates. 3000.8 Section 3000.8 Public...OF LAND MANAGEMENT, DEPARTMENT OF THE INTERIOR MINERALS MANAGEMENT (3000) MINERALS MANAGEMENT:...

2013-10-01

317

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

Code of Federal Regulations, 2012 CFR

... 2012-10-01 false Management of Federal minerals from reserved mineral estates. 3000.8 Section 3000.8 Public...OF LAND MANAGEMENT, DEPARTMENT OF THE INTERIOR MINERALS MANAGEMENT (3000) MINERALS MANAGEMENT:...

2012-10-01

318

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

Code of Federal Regulations, 2014 CFR

... 2014-10-01 2014-10-01 false Minerals soluble in water; brines; minerals taken in solution. 3594.5 Section 3594...LAND MANAGEMENT, DEPARTMENT OF THE INTERIOR MINERALS MANAGEMENT (3000) SOLID MINERALS...

2014-10-01

319

Mineral Cleavage: a practical experiment  

NSDL National Science Digital Library

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

Sharon Browning

320

Radioactivity in bottled mineral waters  

Microsoft Academic Search

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

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

1999-01-01

321

Nitrogen mineralization in production agriculture  

Technology Transfer Automated Retrieval System (TEKTRAN)

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

322

Investigating Minerals: Promoting Integrated Inquiry  

ERIC Educational Resources Information Center

"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…

Thompson, Rudi; Carmack, Elizabeth

2007-01-01

323

Compensation of Navajo Uranium Miners  

NSDL National Science Digital Library

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

World Information Service on Energy Uranium Project

324

A Mineral Processing Field Course  

ERIC Educational Resources Information Center

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

Carmody, Maurice

2014-01-01

325

Evaporates, petroleum and mineral resources  

SciTech Connect

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

Melvin, J.L.

1991-01-01

326

Acidophiles in bioreactor mineral processing  

NSDL National Science Digital Library

This scientific paper provides a brief introduction into the use and development of industrial mineral-processing bioreactors and reviews the variety of microfloral species used in bioreactors. Additionally, the authors discuss recent microbiological and process developments with thermoacidophiles that could expand the range of mineral sulfides processed commercially using microorganisms. A subscription to Extremophiles is required to access this article electronically.

P.R. Norris

327

Adverse possession of subsurface minerals  

SciTech Connect

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

Bowles, P.N.

1983-01-01

328

Ex situ aqueous mineral carbonation  

SciTech Connect

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.

Stephen J. Gerdemann; William K. O'Connor; David C. Dahlin; Larry R. Penner; Hank Rush [National Energy Technology Laboratory, Albany, OR (United States)

2007-04-01

329

Mineral requirements of elderly people.  

PubMed

Poor mineral nutrition reported in elderly people is attributed in large part to low dietary intake. Evaluation of the adequacy of mineral nutriture is limited for several minerals because of inadequate methods for assessing mineral status. In addition, there is a general lack of information about mineral nutriture and metabolism in very old people (> 85 y). Given these reservations, the 1989 recommended dietary allowance (RDA) for iron, zinc, and selenium appears adequate for elderly people, as does the estimated safe and adequate daily dietary intake (ESADDI) recommendation for copper. In contrast, the current RDAs for calcium and magnesium and the ESADDI for chromium need careful reevaluation. Current recommendations for calcium may be too low, whereas those for magnesium and chromium may be higher than necessary. For phosphorus, iodine, manganese, fluoride, and molybdenum the available data are insufficient to make a critical judgment about the appropriateness of the dietary recommendations for elderly people. PMID:7661110

Wood, R J; Suter, P M; Russell, R M

1995-09-01

330

Lifetime sedentary living accelerates some aspects of secondary aging.  

PubMed

Lifetime physical inactivity interacts with secondary aging (i.e., aging caused by diseases and environmental factors) in three patterns of response. First, lifetime physical inactivity confers no apparent effects on a given set of physiological functions. Second, lifetime physical inactivity accelerates secondary aging (e.g., speeding the reduction in bone mineral density, maximal oxygen consumption, and skeletal muscle strength and power), but does not alter the primary aging of these systems. Third, a lifetime of physical activity to the age of ?60-70 yr old totally prevents decrements in some age-associated risk factors for major chronic diseases, such as endothelial dysfunction and insulin resistance. The present review provides ample and compelling evidence that physical inactivity has a large impact in shortening average life expectancy. In summary, physical inactivity plays a major role in the secondary aging of many essential physiological functions, and this aging can be prevented through a lifetime of physical activity. PMID:21836048

Booth, Frank W; Laye, Matthew J; Roberts, Michael D

2011-11-01

331

Secondary Infobook Activities  

NSDL National Science Digital Library

This high school resource includes a set of student worksheets on energy, including topics like biomass, coal, geothermal energy, hydropower, natural gas, solar power, electricity and others. Answer keys are provided for all of the worksheets, and correlations to national science content standards are provided as well. This resource is intended to be used along with the secondary energy infobook, which can be found here.This material may be downloaded in PDF file format.

332

Secondary Forms of Hypertension  

Microsoft Academic Search

\\u000a In most studies, hypertension in children has been secondary to an identifiable cause in a large majority of those studied\\u000a (1,2). This has changed during the relatively recent epidemic of childhood obesity, where primary hypertension in many centers\\u000a now is the most common cause form of hypertension (3). In adults primary hypertension is the dominating diagnosis. This chapter will discuss

Kjell Tullus

333

43 CFR 3861.3 - Mineral surveyors.  

Code of Federal Regulations, 2013 CFR

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

2013-10-01

334

43 CFR 3830.10 - Locatable minerals.  

Code of Federal Regulations, 2014 CFR

... 2014-10-01 false Locatable minerals. 3830.10 Section 3830.10 ...MANAGEMENT, DEPARTMENT OF THE INTERIOR MINERALS MANAGEMENT (3000) LOCATING, RECORDING...SITES; GENERAL PROVISIONS Mining Law Minerals § 3830.10 Locatable...

2014-10-01

335

76 FR 44892 - Information Collection; Locatable Minerals  

Federal Register 2010, 2011, 2012, 2013, 2014

...USDA, Forest Service, Minerals and Geology Management Staff, Mail Stop 1126, 1601...at USDA Forest Service, Minerals and Geology Management Staff, 1601 N. Kent St...Tony Ferguson, Director, Minerals and Geology Management, at 703-605-4785....

2011-07-27

336

Petroleum County Secondary Data Analysis  

E-print Network

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

Maxwell, Bruce D.

337

Economic drivers of mineral supply  

USGS Publications Warehouse

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

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

2003-01-01

338

Technical Subjects in Secondary Schools  

ERIC Educational Resources Information Center

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

Howard, A. E.

2008-01-01

339

Mindat.org: The Mineral Database  

NSDL National Science Digital Library

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

340

Mineral induction by immobilized phosphoproteins  

NASA Technical Reports Server (NTRS)

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

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

1997-01-01

341

Moon's Pink Mineral  

NASA Astrophysics Data System (ADS)

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

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

2014-12-01

342

Universal ripper miner  

DOEpatents

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

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

1991-01-01

343

Origin and paleoenvironmental interpretation of aluminum phosphate-sulfate minerals in a Neoproterozoic Baltic paleosol  

NASA Astrophysics Data System (ADS)

Aluminum phosphate-sulfate (APS) mineral solid-solutions occur as accessory phases in different sedimentary and hydrothermal deposits. Their composition is a sensitive environmental indicator recording changes in pH, temperature and chemical composition of the weathering, diagenetic or hydrothermal fluids. In this contribution we studied APS mineralization in a Neoproterozoic paleotropical paleosol developed on Paleo-Mesoproterozoic crystalline basement in the Baltic Basin. Small and disseminated APS minerals occur in high abundance (up to 4 wt.% of crystalline phases) in the weathering profile developed on gabbroic rocks rich in magmatic apatite. APS minerals belonging to a goyazite-florencite-svanbergite-woodhouseite solid-solution series occur in the uppermost part of the weathering profile and are replaced down-profile with secondary apatite. The change from APS minerals to secondary apatite precipitates reflects a paleo-pH gradient in the weathering profile from acidic (pH < 6) in the uppermost few meters in the APS precipitation zone, to neutral or near neutral at 4-5 m-depth from the paleoweathered surface where secondary apatite occurs. Typically uniform < 5 ?m-size APS crystallites suggest rapid precipitation in a highly supersaturated solution, but these crystals show a fine zonal structure whose nature and formation mechanism remain unclear.

Vircava, Ilze; Somelar, Peeter; Liivamägi, Sirle; Kirs, Juho; Kirsimäe, Kalle

2015-04-01

344

Is the geological concept of clay minerals appropriate for soil science? A literature-based and philosophical analysis  

NASA Astrophysics Data System (ADS)

Data in the literature for soils that are dominated by each of the main types of clay minerals were examined and compared with those for reference clay minerals of the same types to determine the extent to which the nature and properties of clay-size minerals in soils could be explained by those of clay minerals with the same name from non-soil, ‘geological’ environments. Published information on soils from Australia, New Zealand and Iran was sourced for this study. The clay fractions of each of the soils are dominated by either one of the common phyllosilicates: kaolinite, halloysite, illite/mica, vermiculite, smectite, and palygorskite, or by the nanocrystalline mineral, allophane. Data for samples of kaolinite that had been extracted from soils from several countries (Australia, Thailand, Indonesia and Brazil) and purified before characterization have also been examined. In soils, each dominant clay mineral is generally associated with other materials, including iron oxides, other phyllosilicates and/or nanocrystalline minerals and organic matter. As the most studied example of an extracted phyllosilicate, kaolinite shows a wide range of properties in different soils, but a narrower range of properties within a particular locality. However, almost all of the soil kaolinites studied have larger specific surface areas and higher cation exchange capacities than reference kaolinites. The literature also reveals that, among phyllosilicates in soils, illites have a wide range of potassium contents, expandable minerals (vermiculites and smectites) may be interlayered by hydroxy-Al species particularly, and smectitic layers often occur interstratified with other layers, including those of illite, kaolinite and halloysite. The variability of soil phyllosilicates and their common association with other, often poorly crystallized but highly reactive minerals and compounds can be explained by their formation in the highly heterogeneous and dynamic soil environment. Phyllosilicates from non-soil or geological sources are poor models for the representation of secondary clay-size minerals in soils. In philosophical terms, the reduction of soil mineralogy to mineralogy as it is practiced within geology is misleading because of the differences between the minerals formed in soil and geological environments. In other words, clay minerals as they are defined as mineralogical entities for geology are of a different ‘kind’ to clay minerals in soils and cannot serve as ‘types’ or ‘stereotypes’ to enable explanation of the contribution of secondary clay-size minerals to soil properties or behavior. It is more useful to view clay minerals in soils as secondary inorganic compounds of clay-size than to follow their definition for non-soil purposes as plastic phyllosilicate minerals.

Churchman, G. Jock

345

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

PubMed Central

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

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

2012-01-01

346

Mining, Minerals and Sustainable Development  

NSDL National Science Digital Library

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

347

Designing Clothing for Coal Miners  

ERIC Educational Resources Information Center

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

Watkins, Susan M.

1977-01-01

348

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

NASA Astrophysics Data System (ADS)

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.

Schwenzer, Susanne P.; Kring, David A.

2013-09-01

349

Mineral deposit density; an update  

USGS Publications Warehouse

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

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

2001-01-01

350

Geochemistry and Minerality of Wine  

NASA Astrophysics Data System (ADS)

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

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

2010-12-01

351

Deep Seabed Mineral Resources Act  

Microsoft Academic Search

The Deep Seabed Mineral Resources Act, approved by the Senate Energy Committee in 1979, would permit U.S. mining interests to begin commercial recovery of hard minerals from the ocean floor. Under the proposed act, NOAA will regulate mining activities by issuing exploration licenses. The act demonstrates the U.S.'s dual commitment to a new and comprehensive internatonal law of the sea

1980-01-01

352

Mineral of the month: magnesium  

USGS Publications Warehouse

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

Kramer, Deborah A.

2005-01-01

353

The Zapot pegmatite mineral county  

USGS Publications Warehouse

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

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

1999-01-01

354

Persulfate activation by subsurface minerals  

NASA Astrophysics Data System (ADS)

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

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

2010-06-01

355

Persulfate activation by subsurface minerals.  

PubMed

Persulfate dynamics in the presence of subsurface minerals was investigated as a basis for understanding persulfate activation for in situ chemical oxidation (ISCO). The mineral-mediated decomposition of persulfate and generation of oxidants and reductants was investigated with four iron and manganese oxides and two clay minerals at both low pH (<7) and high pH (>12). The manganese oxide birnessite was the most effective initiator of persulfate for degrading the oxidant probe nitrobenzene, indicating that oxidants are generated at both low and high pH regimes. The iron oxide goethite was the most effective mineral for degrading the reductant probe hexachloroethane. A natural soil and two soil fractions were used to confirm persulfate activation by synthetic minerals. The soil and soil fractions did not effectively promote the generation of oxidants or reductants. However, soil organic matter was found to promote reductant generation at high pH. The results of this research demonstrate that synthetic iron and manganese oxides can activate persulfate to generate reductants and oxidants; however, iron and manganese oxides in the natural soil studied do not show the same reactivity, most likely due to the lower masses of the metal oxides in the soil relative to the masses studied in isolated mineral systems. PMID:20439128

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

2010-06-25

356

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

USGS Publications Warehouse

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

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

2011-01-01

357

Understanding mineral dusts from the Middle East  

NASA Astrophysics Data System (ADS)

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

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

2012-12-01

358

1996 annual report on Alaska's mineral resources  

USGS Publications Warehouse

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

Schneider, Jill L.

1997-01-01

359

Minerals Arranged by the New Dana Classification  

NSDL National Science Digital Library

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

David Barthelmy

360

Relationships Between Calcium Silicates and Clay Minerals  

Microsoft Academic Search

The crystal-chemical basis of the relationship between hydrated calcium silicate and clay minerals is discussed, and a review is given of recent work on the tobermorite minerals, the group of hydrated calcium silicates which most nearly resembles the clay minerals. New data are presented for the specific gravities, refractive indices, basal spacings, and dehydration isobars of synthetic tobermorite minerals, and

H. F. W. Taylor; J. W. HowlsoN

1956-01-01

361

Portable Radiometer Identifies Minerals in the Field  

NASA Technical Reports Server (NTRS)

Hand-held optical instrument aids in identifying minerals in field. Can be used in exploration for minerals on foot or by aircraft. The radiometer is especially suitable for identifying clay and carbonate minerals. Radiometer measures reflectances of mineral at two wavelengths, computes ratio of reflectances, and displays ratio to user.

Goetz, A. F. H.; Machida, R. A.

1982-01-01

362

Historical Events in Minerals and Materials  

NSDL National Science Digital Library

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

David Morse

363

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

NASA Astrophysics Data System (ADS)

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

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

2014-08-01

364

30 CFR 281.8 - Rights to minerals.  

Code of Federal Regulations, 2010 CFR

30 Mineral Resources 2 2010-07-01 2010-07-01 false Rights to minerals. 281.8 Section 281.8 Mineral Resources MINERALS MANAGEMENT SERVICE, DEPARTMENT OF THE INTERIOR OFFSHORE LEASING OF MINERALS OTHER...

2010-07-01

365

Defining reactive sites on hydrated mineral surfaces: Rhombohedral carbonate minerals  

NASA Astrophysics Data System (ADS)

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

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

2009-08-01

366

Formation and Reactivity of Biogenic Iron Minerals  

SciTech Connect

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

Ferris, F. Grant

2002-06-01

367

Biomineralization: mineral formation by organisms  

NASA Astrophysics Data System (ADS)

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

Addadi, Lia; Weiner, Steve

2014-09-01

368

Management of secondary peritonitis.  

PubMed Central

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

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

1996-01-01

369

GMT adaptive secondary design  

NASA Astrophysics Data System (ADS)

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

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

2010-07-01

370

J Bone Miner Metab . Author manuscript Mineral maturity and crystallinity index are distinct characteristics of bone  

E-print Network

J Bone Miner Metab . Author manuscript Page /1 13 Mineral maturity and crystallinity index are distinct characteristics of bone mineral Delphine Farlay 1 * , G rard Panczeré 2 , Christian Rey 3 , Pierre the hypothesis that mineral maturity and crystallinity index are two different characteristics of bone mineral

Paris-Sud XI, Université de

371

The impact of powder X-ray diffraction on mineral science, mineral processing and process  

E-print Network

The impact of powder X-ray diffraction on mineral science, mineral processing and process.8% Australia 8.8% South Africa 8.6% Brazil 3.6% India 2.3% http://minerals.usgs.gov/minerals/pubs Research in this field is a priority Resource sustainability is also important 2 #12;XRD in the Minerals Industry

Magee, Joseph W.

372

Microtextured Surfaces for Turbine Blade Impingement Cooling  

NASA Technical Reports Server (NTRS)

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.

Fryer, Jack

2014-01-01

373

Traditional Methods for Mineral Analysis  

NASA Astrophysics Data System (ADS)

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

Ward, Robert E.; Carpenter, Charles E.

374

Hyperspectral analysis of clay minerals  

NASA Astrophysics Data System (ADS)

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

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

2014-11-01

375

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

NASA Astrophysics Data System (ADS)

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.

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

2014-09-01

376

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

Code of Federal Regulations, 2013 CFR

...2013-10-01 2013-10-01 false Segregation of mineral from non-mineral land. 3873.1 Section 3873.1 Public Lands...OF LAND MANAGEMENT, DEPARTMENT OF THE INTERIOR MINERALS MANAGEMENT (3000) ADVERSE CLAIMS, PROTESTS...

2013-10-01

377

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

Code of Federal Regulations, 2014 CFR

...2014-10-01 2014-10-01 false Segregation of mineral from non-mineral land. 3873.1 Section 3873.1 Public Lands...OF LAND MANAGEMENT, DEPARTMENT OF THE INTERIOR MINERALS MANAGEMENT (3000) ADVERSE CLAIMS, PROTESTS...

2014-10-01

378

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

Code of Federal Regulations, 2011 CFR

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

2011-10-01

379

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

Code of Federal Regulations, 2012 CFR

...2012-10-01 2012-10-01 false Segregation of mineral from non-mineral land. 3873.1 Section 3873.1 Public Lands...OF LAND MANAGEMENT, DEPARTMENT OF THE INTERIOR MINERALS MANAGEMENT (3000) ADVERSE CLAIMS, PROTESTS...

2012-10-01

380

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

Code of Federal Regulations, 2011 CFR

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

2011-10-01

381

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

Code of Federal Regulations, 2012 CFR

...2012-10-01 2012-10-01 false Mineral reservation in patent; conditions to be noted on mineral applications. 3814.2 Section 3814...MANAGEMENT, DEPARTMENT OF THE INTERIOR MINERALS MANAGEMENT (3000) LANDS AND...

2012-10-01

382

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

Code of Federal Regulations, 2013 CFR

...2013-10-01 2013-10-01 false Mineral reservation in patent; conditions to be noted on mineral applications. 3814.2 Section 3814...MANAGEMENT, DEPARTMENT OF THE INTERIOR MINERALS MANAGEMENT (3000) LANDS AND...

2013-10-01

383

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

Code of Federal Regulations, 2014 CFR

...2014-10-01 2014-10-01 false Mineral reservation in patent; conditions to be noted on mineral applications. 3814.2 Section 3814...MANAGEMENT, DEPARTMENT OF THE INTERIOR MINERALS MANAGEMENT (3000) LANDS AND...

2014-10-01

384

Calcioolivine, ?-Ca2SiO4, an old and New Mineral species  

NASA Astrophysics Data System (ADS)

Calcioolivine has been included into the MDI mineral database in the list of grandfathered minerals. Its history, together with related artificial compounds, is extremely complex: various minerals and compounds received this name, including natural orthorhombic Ca orthosilicate. In this paper, the crystal structure and properties of natural calcioolivine are described for the first time. The new mineral has been found at Mt. Lakargi, Upper Chegem Plateau, the northern Caucasus, Kabarda-Balkaria Republic, Russia. It has been identified in skarnified, primary carbonate xenoliths entrained by middle to late Pliocene silicic ignimbrites of the Upper Chegem caldera. These xenoliths of a few centimeters to a few meters in size are located close to the volcanic vent. Calcioolivine rims relics of larnite and occurs as relict grains among crystals of spurrite, rondorfite, wadalite or secondary hillebrandite, afwillite, thaumasite, and ettringite. Hillebrandite is the major product of alteration of calcioolivine; larnite is relatively more resistant to low-temperature alteration. Spurrite, larnite, tilleyite, kilchoanite, cuspidine, wadalite, rondorfite, reinhardbraunsite, lakargiite (CaZrO3), members of ellestadite series, afwillite, ettringite, katoite, and thaumasite are associated minerals. It is inferred that calcioolivine has been produced as a result of interaction of host carbonate rocks in xenoliths with volcanic lava and gases during eruption. The name calcioolivine was approved by the Commission on New Minerals and Mineral Names, International Mineralogical Association, September 6, 2007 (no. 07-B).

Zadov, A. E.; Gazeev, V. M.; Pertsev, N. N.; Gurbanov, A. G.; Gobechiya, E. R.; Yamnova, N. A.; Chukanov, N. V.

2009-12-01

385

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

NASA Astrophysics Data System (ADS)

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

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

2009-11-01

386

Nucleoside phosphorylation by phosphate minerals.  

PubMed

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

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

2007-06-01

387

Bone Mineral Density and Logarithms  

NSDL National Science Digital Library

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

2014-09-18

388

Handbook of Marine Mineral Deposits  

NASA Astrophysics Data System (ADS)

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.

Moore, George W.

389

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...

390

Secondary Control Reviewed and Defined  

ERIC Educational Resources Information Center

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…

Morling, Beth; Evered, Sharrilyn

2006-01-01

391

Language Study in Secondary Education.  

ERIC Educational Resources Information Center

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

Stork, F. C.

1980-01-01

392

Cellular compartmentalization of secondary metabolism  

PubMed Central

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 shared with the most essential processes of the cell (e.g., amino acids, acetyl CoA, NADPH), enzymes for secondary metabolite synthesis are compartmentalized at conserved subcellular sites that position pathway enzymes to use these common biochemical precursors. Co-compartmentalization of secondary metabolism pathway enzymes also may function to channel precursors, promote pathway efficiency and sequester pathway intermediates and products from the rest of the cell. In this review we discuss the compartmentalization of three well-studied fungal secondary metabolite biosynthetic pathways for penicillin G, aflatoxin and deoxynivalenol, and summarize evidence used to infer subcellular localization. We also discuss how these metabolites potentially are trafficked within the cell and may be exported. PMID:25709603

Kistler, H. Corby; Broz, Karen

2015-01-01

393

Control Dewar Secondary Vacuum Container  

SciTech Connect

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

Rucinski, R.; /Fermilab

1993-10-04

394

Si isotopes record cyclical dissolution and re-precipitation of pedogenic clay minerals in a podzolic soil chronosequence  

NASA Astrophysics Data System (ADS)

Soils are a major resource on the planet, acting as a key component for ecosystem function. The secondary minerals in the clay fraction are important players in soil biogeochemical processes as they provide a large reactive surface area. However, the origin and evolution of secondary minerals in soils are not yet fully understood. We determined the Si isotope compositions in the clay fraction of a podzolic soil chronosequence and document light 28Si enrichment during pedogenesis that increases with soil age. Relative to the original 'unweathered' clay-size minerals in deepsoil (?30Si = -0.52±0.16 permil), the clay fraction of the topsoil eluvial horizon show less negative ?30Si values (?30Sifrom -0.33 to -0.10 permil), while the clay fraction of the subsoil illuvial horizons is isotopically lighter (?30Si from -0.60 to -0.84 permil). Geochemical and X-ray diffraction analyses show that the on-going enrichment in light 28Si in pedogenic minerals of illuvial subsoil horizons can only be related to the dissolution in the topsoil horizon of clay minerals previously enriched in 28Si. The 28Si enrichment in the clay fraction with pedogenesis and soil age provides consistent evidence for the cyclical dissolution and re-precipitation of pedogenic minerals. Our study shows that the successive generations of clay minerals occur over very short time scales (ca. 300 years). This is instrumental in the evolution of the clay mineral genesis in soils. This soil-forming process has implications for the modeling of soil evolution. Given the importance of clay minerals in the chemical cycles of elements, deciphering the origin of pedogenic Si in clay mineral genesis is central to a better understanding of soil development and associated terrestrial biogeochemical processes.

Cornelis, Jean-Thomas; Weis, Dominique; Lavkulich, Les; Vermeire, Marie-Liesse; Delvaux, Bruno; Barling*, Jane

2014-05-01

395

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...

396

Mysterious Lava Mineral on Mars  

NASA Technical Reports Server (NTRS)

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

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

2004-01-01

397

Mineral nutrition of higher plants  

Microsoft Academic Search

Broadly, the approach which researchers have adopted in this review has been to ask the following questions about mineral nutrients: What properties make them essential. How are they obtained. How effectively are they used. We shall not be considering two most important, but frequently reviewed, aspects of the subject, namely biological fixation of Nâ and its assimilation and mechanisms of

D. T. Clarkson; J. B. Hanson

1980-01-01

398

High temperature mineral fiber binder  

SciTech Connect

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

Miedaner, P.M.

1980-11-25

399

Crystallizing Minerals from Aqueous Solutions  

NSDL National Science Digital Library

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

Dexter Perkins

400

Mineral of the month: indium  

USGS Publications Warehouse

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

George, Micheal W.

2004-01-01

401

Mineral of the month: boron  

USGS Publications Warehouse

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

Lyday, Phyllis A.

2005-01-01

402

Mineral of the month: titanium  

USGS Publications Warehouse

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

Gambogi, Joseph

2004-01-01

403

Mineral of the month: aggregates  

USGS Publications Warehouse

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

Tepordei, Valentin V.

2005-01-01

404

Mineral of the month: rhenium  

USGS Publications Warehouse

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

Magyar, Michael J.

2005-01-01

405

Detrital Mineral Grains in Tektites.  

PubMed

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

Bairnes, V E

1963-12-27

406

Mineral impurities in coal combustion  

SciTech Connect

This article discusses the many and varied problems associated with coal combustion and suggests remedial measures to assist in producing electrical energy from coal more efficiently. Contents include: influence of coal mineral matter on boiler design; mineral impurities in coal; quality of coal utilized in power stations; coal grinding, abrasive fuel minerals and plant wear; particulates silicate minerals in boiler flame; reactions of nonsilicate impurities in coal flame; creation, capture and coalescence of particulate ash in boiler flame; slag viscosity; sintering, fusion and slagging propensities of coal ashes, adhesion of ash deposit on boiler tubes and refractory materials; deposition mechanisms, rate measurements and the mode of formation of boiler deposits; thermal radiation and heat transfer properties of boiler deposits; measures to combat boiler fouling and slagging; some specific ash-related problems with US Coals; use of additives in coal fired boilers; high temperature corrosion in coal-fired plants; ash impaction erosion wear; low temeprature fouling and corrosion; comparison of ash-related problems in pulverized fuel and other coal-fired systems.

Raask, E.

1985-01-01

407

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

NASA Astrophysics Data System (ADS)

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

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

2013-12-01

408

Transition to Secondary - an Experiment in a Scottish Secondary School  

ERIC Educational Resources Information Center

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

Dutch, R. D.; McCall, J.

1974-01-01

409

King Fahd University of Petroleum and Minerals  

E-print Network

King Fahd University of Petroleum and Minerals Summer Training Report 2010 Abdul-Aziz Al ...........................................................................................13 #12;2 1. Introduction King Fahd University of Petroleum and Minerals (KFUPM) give an opportunity

Al-Ghadhban, Samir

410

36 CFR 292.18 - Mineral resources.  

Code of Federal Regulations, 2010 CFR

...Public Property 2 2010-07-01 2010-07-01 false Mineral resources. 292.18 Section 292.18 Parks, Forests...Sawtooth National Recreation Area-Federal Lands § 292.18 Mineral resources. (a) Occupancy. No unpatented...

2010-07-01

411

43 CFR 8.5 - Mineral rights.  

Code of Federal Regulations, 2013 CFR

...OF THE DEPARTMENTS OF THE 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 purposes,...

2013-10-01

412

43 CFR 8.5 - Mineral rights.  

Code of Federal Regulations, 2014 CFR

...OF THE DEPARTMENTS OF THE 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 purposes,...

2014-10-01

413

43 CFR 8.5 - Mineral rights.  

Code of Federal Regulations, 2011 CFR

...OF THE DEPARTMENTS OF THE 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 purposes,...

2011-10-01

414

43 CFR 8.5 - Mineral rights.  

Code of Federal Regulations, 2012 CFR

...OF THE DEPARTMENTS OF THE 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 purposes,...

2012-10-01

415

A personal miner's carbon monoxide alarm  

SciTech Connect

Underground miners may be exposed to hazardous quantities of toxic gases, such as carbon monoxide (CO), generated from mine fires or explosions. Every underground miner is required to carry a filter self-rescuer (FSR), which when operated will remove CO from the miner's breathing air. In addition, every underground miner must have a self-contained self-rescuer(SCSR) near the worksite that will supply breathing oxygen. In many situations, miners do not know when to don either rescuer since they do not know if there is a fire in the mine, nor do they carry instrumentation necessary for the detection of the toxic, colorless, and odorless fire product CO. If each miner carried a personal CO alarm, which would respond to high concentrations of CO, the miner would then be alerted when to don either the FSR or SCSR and exit the mine. The authors report on the development of a prototype personal miner's CO alarm called PEMCOAL.

Chilton, J.E.; Carpenter, C.R.

1989-01-01

416

Vitamin and Mineral Supplement Fact Sheets  

MedlinePLUS

... view as pdf | share Create PDF 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 ...

417

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

NASA Astrophysics Data System (ADS)

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

Lo, F.; Chen, H.

2013-12-01

418

Secondary prevention in heart failure.  

PubMed

Although most recent investigations into sudden cardiac death prevention in heart failure patients have been focused on primary prevention, secondary indications for defibrillators and medical therapy remain vitally important in this complex patient group. Antiarrhythmic therapy is currently used primarily as adjuvant therapy to implantable defibrillators. Secondary prophylaxis defibrillator trials have shown clear benefit in preventing recurrent sudden cardiac death, despite concern over inappropriate shocks and the potential detrimental effects of appropriate shocks. Device programming for secondary prophylaxis can help ameliorate these issues. This article discusses these issues as well as the continued underuse of defibrillators in specific populations. PMID:21439497

Robinson, Melissa R; Epstein, Andrew E; Callans, David J

2011-04-01

419

A personal miner's carbon monoxide alarm  

Microsoft Academic Search

Underground miners may be exposed to hazardous quantities of toxic gases, such as carbon monoxide (CO), generated from mine fires or explosions. Every underground miner is required to carry a filter self-rescuer (FSR), which when operated will remove CO from the miner's breathing air. In addition, every underground miner must have a self-contained self-rescuer(SCSR) near the worksite that will supply

J. E. Chilton; C. R. Carpenter

1989-01-01

420

Interpreting U-Pb data from primary and secondary features in lunar zircon  

NASA Astrophysics Data System (ADS)

In this paper, we describe primary and secondary microstructures and textural characteristics found in lunar zircon and discuss the relationships between these features and the zircon U-Pb isotopic systems and the significance of these features for understanding lunar processes. Lunar zircons can be classified according to: (i) textural relationships between zircon and surrounding minerals in the host breccias, (ii) the internal microstructures of the zircon grains as identified by optical microscopy, cathodoluminescence (CL) imaging and electron backscattered diffraction (EBSD) mapping and (iii) results of in situ ion microprobe analyses of the Th-U-Pb isotopic systems. Primary zircon can occur as part of a cogenetic mineral assemblage (lithic clast) or as an individual mineral clast and is unzoned, or has sector and/or oscillatory zoning. The age of primary zircon is obtained when multiple ion microprobe analyses across the polished surface of the grain give reproducible and essentially concordant data. A secondary set of microstructures, superimposed on primary zircon, include localised recrystallised domains, localised amorphous domains, crystal-plastic deformation, planar deformation features and fractures, and are associated with impact processes. The first two secondary microstructures often yield internally consistent and close to concordant U-Pb ages that we interpret as dating impact events. Others secondary microstructures such as planar deformation features, crystal-plastic deformation and micro-fractures can provide channels for Pb diffusion and result in partial resetting of the U-Pb isotopic systems.

Grange, M. L.; Pidgeon, R. T.; Nemchin, A. A.; Timms, N. E.; Meyer, C.

2013-01-01

421

21 CFR 178.3620 - Mineral oil.  

Code of Federal Regulations, 2012 CFR

... (1) The mineral oil consists of virgin petroleum... (2) The mineral oil may be used only in the...the following types of food: Dry grains and dry seeds...lentils); whole root crop vegetables of the types identified...weight of residual mineral oil. (3) The...

2012-04-01

422

21 CFR 178.3620 - Mineral oil.  

Code of Federal Regulations, 2013 CFR

... (1) The mineral oil consists of virgin petroleum... (2) The mineral oil may be used only in the...the following types of food: Dry grains and dry seeds...lentils); whole root crop vegetables of the types identified...weight of residual mineral oil. (3) The...

2013-04-01

423

21 CFR 178.3620 - Mineral oil.  

Code of Federal Regulations, 2011 CFR

... (1) The mineral oil consists of virgin petroleum... (2) The mineral oil may be used only in the...the following types of food: Dry grains and dry seeds...lentils); whole root crop vegetables of the types identified...weight of residual mineral oil. (3) The...

2011-04-01

424

21 CFR 178.3620 - Mineral oil.  

Code of Federal Regulations, 2014 CFR

... (1) The mineral oil consists of virgin petroleum... (2) The mineral oil may be used only in the...the following types of food: Dry grains and dry seeds...lentils); whole root crop vegetables of the types identified...weight of residual mineral oil. (3) The...

2014-04-01

425

Rock-Forming Minerals in Thin Section  

NSDL National Science Digital Library

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

Steven Dutch

426

36 CFR 331.17 - Minerals.  

Code of Federal Regulations, 2010 CFR

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

2010-07-01

427

Mineral minimization in nature's alternative teeth  

E-print Network

REVIEW Mineral minimization in nature's alternative teeth Christopher C. Broomell1, , Rashda K, University of California, Santa Barbara, CA 93106, USA Contrary to conventional wisdom, mineralization, with little to no help from mineralization. Based on biochemical analyses, three of these mouthparts, the jaws

Zok, Frank

428

Introduction to Crystallography and Mineral Crystal Systems  

NSDL National Science Digital Library

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

Bob Keller

429

Institute for Mineral and Energy Resources  

E-print Network

Institute for Mineral and Energy Resources #12;IMER VISION IMER's vision is to enable the efficient and sustainable use and development of the world's mineral and energy resources for the benefit of society of excellence for fundamental and applied research, innovation and technology transfer in mineral and energy

430

21 CFR 573.680 - Mineral oil.  

Code of Federal Regulations, 2010 CFR

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

2010-04-01

431

BIOMEDICAL VIGNETTE Mineral Surface Directed Membrane Assembly  

E-print Network

BIOMEDICAL VIGNETTE Mineral Surface Directed Membrane Assembly Martin M. Hanczyc & Sheref S. Mansy within a membrane. This highlights the ability of mineral surfaces to bring together and organize key components of primordial life. We have extended our analysis of mineral-mediated vesicle catalysis to include

Heller, Eric

432

43 CFR 8.5 - Mineral rights.  

Code of Federal Regulations, 2010 CFR

...Interior 1 2010-10-01 2010-10-01 false Mineral rights. 8.5 Section 8.5 Public Lands...ARMY RELATIVE TO RESERVOIR PROJECT LANDS § 8.5 Mineral rights. Mineral, oil and gas rights will not be acquired...

2010-10-01

433

How microbes influence mineral growth and dissolution  

Microsoft Academic Search

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

Henry L. Ehrlich

1996-01-01

434

A miner's personal carbon monoxide alarm  

Microsoft Academic Search

For the purpose of alerting an underground miner to life-threatening concentrations of carbon monoxide (CO) a miner's personal CO alarm prototype called PEMCOAL has been developed by the Bureau of Mines. The PEMCOAL unit is small enough to be carried on a miner's belt, has a flashlamp visual alarm, requires to calibration for use, and uses a disk sensor which

JOSEPH E. CHILTON; CLARENCE R. CARPENTER

1989-01-01

435

Minerals by Physical and Optical Properties  

NSDL National Science Digital Library

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

David Barthelmy

436

PROGRAM AND ABSTRACTS FOR CLAY MINERALS SOCIETY  

E-print Network

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

Rathbun, Julie A.

437

Carbon dioxide sequestration by mineral carbonation  

Microsoft Academic Search

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

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

2007-01-01

438

Remote Sensing of Soils, Minerals, and Geomorphology  

E-print Network

Remote Sensing of Soils, Minerals, and Geomorphology Remote Sensing of Soils,Remote Sensing of Soils, Minerals, and GeomorphologyMinerals, and Geomorphology · 26% of the Earth's surface is exposed, drainage patterns, and geomorphology (landforms). ·· 26% of the Earth's surface is exposed land26

439

ENVIRONMENTAL RESEARCH 37, 364-372 (1985) Mineral Particles, Mineral Fibers, and Lung Cancer'  

E-print Network

ENVIRONMENTAL RESEARCH 37, 364-372 (1985) Mineral Particles, Mineral Fibers, and Lung Cancer Columbia V6T I W.5, Canada Received June 15. 1984 The total fibrous and nonfibrous mineral content class. The lung cancer patients had an average of 525 * 369 x lo6 exogenous mineral particles and 17

Ahmad, Sajjad

440

2.20 Properties of Rocks and Minerals -Magnetic Properties of Rocks and Minerals  

E-print Network

2.20 Properties of Rocks and Minerals - Magnetic Properties of Rocks and Minerals R. J. Harrison, R 621 622 623 623 579 #12;580 Magnetic Properties of Rocks and Minerals 2.20.5.3 2.20.5.4 2, and are present in all types of rocks, sediments, and soils. These minerals retain a memory of the geomagnetic

Dunin-Borkowski, Rafal E.

441

Accessible Capacity of Secondary Users  

E-print Network

A new problem formulation is presented for the Gaussian interference channels (GIFC) with two pairs of users, which are distinguished as primary users and secondary users, respectively. The primary users employ a pair of encoder and decoder that were originally designed to satisfy a given error performance requirement under the assumption that no interference exists from other users. In the case when the secondary users attempt to access the same medium, we are interested in the maximum transmission rate (defined as {\\em accessible capacity}) at which secondary users can communicate reliably without affecting the error performance requirement by the primary users under the constraint that the primary encoder (not the decoder) is kept unchanged. By modeling the primary encoder as a generalized trellis code (GTC), we are then able to treat the secondary link as a finite state channel (FSC). The relation of the accessible capacity to the capacity region of the GIFC is revealed. Upper and lower bounds on the acce...

Ma, Xiao; Lin, Lei; Bai, Baoming

2010-01-01

442

40 CFR 133.102 - Secondary treatment.  

Code of Federal Regulations, 2012 CFR

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

2012-07-01

443

40 CFR 133.102 - Secondary treatment.  

Code of Federal Regulations, 2014 CFR

...2014-07-01 2013-07-01 true Secondary treatment. 133.102 Section 133.102 Protection...CONTINUED) WATER PROGRAMS SECONDARY TREATMENT REGULATION § 133.102 Secondary treatment. The following paragraphs...

2014-07-01

444

40 CFR 133.102 - Secondary treatment.  

Code of Federal Regulations, 2013 CFR

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

2013-07-01

445

40 CFR 133.102 - Secondary treatment.  

Code of Federal Regulations, 2011 CFR

...2011-07-01 2011-07-01 false Secondary treatment. 133.102 Section 133.102 Protection...CONTINUED) WATER PROGRAMS SECONDARY TREATMENT REGULATION § 133.102 Secondary treatment. The following paragraphs...

2011-07-01

446

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

NSDL National Science Digital Library

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

447

43 CFR 3602.20 - Administration of mineral materials sales.  

Code of Federal Regulations, 2013 CFR

...2013-10-01 2013-10-01 false Administration of mineral materials sales. 3602.20 Section 3602...LAND MANAGEMENT, DEPARTMENT OF THE INTERIOR MINERALS MANAGEMENT (3000) MINERAL MATERIALS DISPOSAL Mineral Materials Sales...

2013-10-01

448

30 CFR 581.8 - Rights to minerals.  

Code of Federal Regulations, 2012 CFR

30 Mineral Resources 2 2012-07-01 2012-07-01 false Rights to minerals. 581.8 Section 581.8 Mineral Resources BUREAU OF OCEAN ENERGY MANAGEMENT, DEPARTMENT OF THE INTERIOR OFFSHORE LEASING OF MINERALS...

2012-07-01

449

25 CFR 225.33 - Assignment of minerals agreements.  

Code of Federal Regulations, 2010 CFR

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

2010-04-01

450

25 CFR 225.33 - Assignment of minerals agreements.  

Code of Federal Regulations, 2014 CFR

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

2014-04-01

451

25 CFR 225.22 - Approval of minerals agreements.  

Code of Federal Regulations, 2013 CFR

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

2013-04-01

452

25 CFR 225.22 - Approval of minerals agreements.  

Code of Federal Regulations, 2010 CFR

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

2010-04-01

453

43 CFR 3602.20 - Administration of mineral materials sales.  

Code of Federal Regulations, 2011 CFR

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

2011-10-01

454

25 CFR 225.33 - Assignment of minerals agreements.  

Code of Federal Regulations, 2011 CFR

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

2011-04-01

455

25 CFR 225.22 - Approval of minerals agreements.  

Code of Federal Regulations, 2012 CFR

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

2012-04-01

456

25 CFR 225.33 - Assignment of minerals agreements.  

Code of Federal Regulations, 2013 CFR

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

2013-04-01

457

25 CFR 225.22 - Approval of minerals agreements.  

Code of Federal Regulations, 2014 CFR

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

2014-04-01

458

30 CFR 581.8 - Rights to minerals.  

Code of Federal Regulations, 2014 CFR

30 Mineral Resources 2 2014-07-01 2014-07-01 false Rights to minerals. 581.8 Section 581.8 Mineral Resources BUREAU OF OCEAN ENERGY MANAGEMENT, DEPARTMENT OF THE INTERIOR OFFSHORE LEASING OF MINERALS...

2014-07-01

459

30 CFR 256.80 - Leases of other minerals.  

Code of Federal Regulations, 2010 CFR

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

2010-07-01

460

25 CFR 225.22 - Approval of minerals agreements.  

Code of Federal Regulations, 2011 CFR

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

2011-04-01

461

30 CFR 581.8 - Rights to minerals.  

Code of Federal Regulations, 2013 CFR

30 Mineral Resources 2 2013-07-01 2013-07-01 false Rights to minerals. 581.8 Section 581.8 Mineral Resources BUREAU OF OCEAN ENERGY MANAGEMENT, DEPARTMENT OF THE INTERIOR OFFSHORE LEASING OF MINERALS...

2013-07-01

462

43 CFR 3602.20 - Administration of mineral materials sales.  

Code of Federal Regulations, 2012 CFR

...2012-10-01 2012-10-01 false Administration of mineral materials sales. 3602.20 Section 3602...LAND MANAGEMENT, DEPARTMENT OF THE INTERIOR MINERALS MANAGEMENT (3000) MINERAL MATERIALS DISPOSAL Mineral Materials Sales...

2012-10-01

463

43 CFR 3602.20 - Administration of mineral materials sales.  

Code of Federal Regulations, 2014 CFR

...2014-10-01 2014-10-01 false Administration of mineral materials sales. 3602.20 Section 3602...LAND MANAGEMENT, DEPARTMENT OF THE INTERIOR MINERALS MANAGEMENT (3000) MINERAL MATERIALS DISPOSAL Mineral Materials Sales...

2014-10-01

464

25 CFR 225.33 - Assignment of minerals agreements.  

Code of Federal Regulations, 2012 CFR

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

2012-04-01

465

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

Microsoft Academic Search

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

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

2010-01-01

466

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

NASA Astrophysics Data System (ADS)

A practical classification of surface textures observed on detrital grains in sands and sandstones is proposed, in order to enhance data reproducibility among operators and to implement the use of high-resolution heavy-mineral data in studies of sediment-generation, provenance, and diagenesis. Five stages of progressive weathering (unweathered, corroded, etched, deeply etched, skeletal) are recognized for diverse detrital minerals. A