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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

Indicators of aqueous alteration in CM carbonaceous chondrites: Microtextures of a layered mineral containing Fe, S, O and Ni  

NASA Astrophysics Data System (ADS)

A petrographic and transmission electron microscopy study of the Mighei, Murchison. and Murray CM carbonaceous chondrites shows that much of the CM matrix material was probably produced by aqueous alteration of olivine, pyroxene, sulfide, and metal. The amount of CM matrix appears to be proportional to the degree of alteration, as suggested by McSween (1979), and microtextures of PCP ("poorly characterized phase") provide evidence of the progressive alteration. PCP is divided into two major types; one occurs in chondrules and aggregates and consists largely of an Fe-Ni-S-O phase (Type-I), and the other occurs in matrix and consists of the Fe-Ni-S-O phase and cronstedtite in various proportions (Type-II). Microtextures of PCP suggest that it resulted from a three-stage alteration process. (1) Type-I was produced by alteration of kamacite in chondrules and aggregates, presumably early, in the parent body regolith. (2) As the alteration advanced, olivine and pyroxene were converted to serpentine. Type-I PCP separated from chondrules and aggregates (into the matrix) during regolith gardening. Simultaneously, the Fe-Ni-S-O phase reacted with Si (released by alteration of olivine and pyroxene), producing well-formed platy cronstedtite and coherent intergrowths of the Fe-Ni-S-O phase and cronstedtite. The Fe-Ni-S-O phase also recrystallized into platy and pod-like crystals. Fe. S. Ni, Cr. and P were leached out of Type-I PCP and were deposited as small grains of Fe-Ni Sulfides, magnetite, chromite. and a mineral (unidentified) containing Fe. Ni, Cr, and P. As a result, PCP came to consist primarily of the Fe-Ni-S-O phase and cronstedtite, i.e., Type-II PCP. (3) During continued alteration, the well formed crystals of the Fe-Ni-S-O phase, cronstedtite, and their intergrowths in Type-II PCP were replaced by poorly formed fibers. In comparison to other CM chondrites, Mighei. Murchison, and Murray are relatively unaltered. Their matrices retain abundant amounts of the Fe-Ni-S-O phase and cronstedtite, commonly as distinctive PCP grains, which account for a large proportion of the Fe in these meteorite matrices. In more altered CM chondrites, much of the Fe-Ni-S-O phase was probably consumed to produce cronstedtite, magnetite, and sulfides. With further alteration, cronstedtite itself reacted with the serpentine to form ferroan serpentine. Thus the CM matrix was increasingly enriched in Mg with alteration, and PCP was increasingly degraded and intimately mixed with the magnesian phyllosilicates.

Tomeoka, Kazushige; Buseck, Peter R.

1985-10-01

3

Indicators of aqueous alteration in CM carbonaceous chondrites: Microtextures of a layered mineral containing Fe, S, O and Ni  

Microsoft Academic Search

A petrographic and transmission electron microscopy study of the Mighei, Murchison. and Murray CM carbonaceous chondrites shows that much of the CM matrix material was probably produced by aqueous alteration of olivine, pyroxene, sulfide, and metal. The amount of CM matrix appears to be proportional to the degree of alteration, as suggested by McSween (1979), and microtextures of PCP (\\

Kazushige Tomeoka; Peter R. Buseck

1985-01-01

4

Reaction microtextures of REE Y Th U accessory minerals in the Monte Capanne pluton (Elba Island, Italy): a possible indicator of hybridization processes  

NASA Astrophysics Data System (ADS)

The study of accessory minerals in granitoid rocks can provide clues to the history of magmatic processes. In particular, the textural chemical characteristics of accessories could represent effective markers of hybridization processes. The concomitant occurrence of contrasting reaction microtextures of REE Y Th U accessory minerals in the Monte Capanne anatectic hybrid pluton suggests the occurrence of transient chemical conditions (alumina saturation up and down in the same system) in the early stages of crystallization. Incongruent dissolution of apatite produced microcrystal clusters of huttonitic monazite, while monazite-(Ce) crystals were replaced by allanite-(Ce)±apatite assemblage at the same location. A magma mingling process, involving acidic peraluminous and mafic metaluminous end-members, can provide the expected initial strong differences in alumina saturation that are able to induce such contrasting reactions. The proposed double exchange of accessory minerals between the two magmas strongly suggests a dynamic setting (stirring and straining of crystal-rich melts) in which anatectic and hybridization processes evolved.

Dini, A.; Rocchi, S.; Westerman, D. S.

2004-10-01

5

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

Microsoft Academic Search

The eruptive history of Monte Vulture has been the subject of several geochronological investigations during the past decades,\\u000a which reliably dated only a small number of eruptions. Understanding the causes of sub-optimum data yield in the past requires\\u000a an interdisciplinary approach. We re-analyzed samples from previous works and present new data on samples from the main volcano-stratigraphic\\u000a units of Monte

Igor M. Villa; Annett Buettner

2009-01-01

6

Metal, mineral waste processing and secondary recovery  

SciTech Connect

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

Reddy, R.G.

1987-04-01

7

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

8

Secondary hydrothermal mineral system in the Campi Flegrei caldera, Italy  

NASA Astrophysics Data System (ADS)

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

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

2012-04-01

9

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

10

Effects of cinacalcet on bone mineral density in patients with secondary hyperparathyroidism  

Microsoft Academic Search

Background. Cinacalcet, a calcimimetic agent, is effec- tive in treating both primary and secondary hyper- parathyroidism. Because hyperparathyroidism induces mineralized bone loss, we investigated the effects of cinacalcet treatment on bone mineral density (BMD) in patients with secondary hyperparathyroidism due to chronic kidney disease. Methods. Ten patients who were receiving haemo- dialysis and four patients, who had stage 4 chronic

Yeong-Hau H. Lien; Arnold L. Silva; David Whittman

2005-01-01

11

The impact of calcimimetics on mineral metabolism and secondary hyperparathyroidism in end-stage renal disease  

Microsoft Academic Search

The impact of calcimimetics on mineral metabolism and secondary hyperparathyroidism in end-stage renal disease. Secondary hyperparathyroidism is often complicated by elevations in calcium and phosphorus either as a result of the disease per se or due to toxicity from current therapeutic options. These disturbances in mineral metabolism limit the successfulness of therapy and have been implicated as contributing to the

Geoffrey A. Block

2003-01-01

12

Microtexture determination by electron back-scatter diffraction  

Microsoft Academic Search

This review describes the use of an experimental technique known as electron back-scatter diffraction (EBSD) to measure microtexture, that is, spatially specific texture measured on an individual orientation basis. Other methods of microtexture determination are briefly described and compared with EBSD. The EBSD technique itself is described in considerable detail including recent developments such as on-line automation. Those EBSD-based microtexture

D. J. Dingley; V. Randle

1992-01-01

13

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

14

Method of making a coating of a microtextured surface  

Microsoft Academic Search

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

John D. Affinito; Gordon L. Graff; Peter M. Martin; Mark E. Gross; Paul E. Burrows; Linda S. Sapochak

2004-01-01

15

Testing attachment point theory: diatom attachment on microtextured polyimide biomimics  

Microsoft Academic Search

This paper explores diatom attachment to a range of laser etched polyimide surfaces to directly test ‘attachment point theory’. Static bioassays were conducted on microtextured polyimide surfaces using four diatom species, Fallacia carpentariae, Nitzschia cf. paleacea, Amphora sp. and Navicula jeffreyi with cell sizes ranging from 1 – 14 ?m. The microtextured polyimides were modelled from natural fouling resistant bivalve surfaces and had

A. J. Scardino; E. Harvey; R. De Nys

2006-01-01

16

Form and Composition of Secondary Mineralization in Fractures in Columbia River Basalts.  

National Technical Information Service (NTIS)

Examination of basalt alteration rinds suggests that pyroxene is altered, along with mesostasis, from the inception of hydrothermal alteration along cooling fractures in Columbia River basalts. The only phyllosilicate secondary mineral in fractures is tri...

J. P. McKinley S. A. Rawson D. G. Horton

1986-01-01

17

Luminescence of secondary uranium minerals at low temperatures  

Microsoft Academic Search

The luminescence spectra were recorded with an ISP-51 spectrograph which was equipped with a photoelectric FI~P-1 attachment, an FI~U-38 photomultiplier, and an t~PP-09mZ recording potentiometer. A test tube, which was made of quartz glass and contained a mineral sample of 5 mg or more, was placed into a transparent Dewar vessel containing liquid nitrogen. Luminescence of the mineral was excited

B. S. Gorobets; G. A. Sidorenko

1974-01-01

18

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

Microsoft Academic Search

Electron microscopic observations of alkali feldspars from soils show that intragranular microtextures, such as exsolution lamellae, and microstructures, primarily dislocations, are both highly significant determinants of the weathering behaviour of these minerals. In particular, strained structure around intersecting edge dislocations in the plane of exsolution lamellae, ?(601), dissolves at a rate which is orders of magnitude greater than unstrained feldspar,

Martin R Lee; Mark E Hodson; Ian Parsons

1998-01-01

19

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

20

Geopolymers from Algerian metakaolin. Influence of secondary minerals  

Microsoft Academic Search

The influence of secondary phases (illite, quartz) on the geopolymerization reaction of metakaolin has been investigated by comparing two metakaolins, one prepared from a pure kaolinite and the other from illite- and quartz-containing Algerian kaolin from the Tamazert region, respectively. Geopolymerization was achieved by mixing the metakaolins with an alkaline sodium silicate solution at room temperature and curing at 50 °C.

Fatima Zibouche; Hacène Kerdjoudj; Jean-Baptiste d'Espinose de Lacaillerie; Henri Van Damme

2009-01-01

21

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

SciTech Connect

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

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

2008-07-15

22

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

23

Nitrification potential of secondary-succession upland oak forests: 1. Mineralization and nitrification during laboratory incubations  

Microsoft Academic Search

Experiments were carried out to examine factors regulating N mineralization and nitrification in upland oak (Quercus spp.) forests of the Missouri Ozarks. Soils were collected from three sites representing secondary oak succession. Sampling dates represented different stages in the phenological development of the vegetation during a 1-yr period. Soils were incubated in the laboratory, and changes in soil NOââ and

J. M. Donaldson; G. S. Henderson

2009-01-01

24

Bacterial and iron oxide aggregates mediate secondary iron mineral formation: green rust versus magnetite.  

PubMed

In the presence of methanoate as electron donor, Shewanella putrefaciens, a Gram-negative, facultative anaerobe, is able to transform lepidocrocite (gamma-FeOOH) to secondary Fe (II-III) minerals such as carbonated green rust (GR1) and magnetite. When bacterial cells were added to a gamma-FeOOH suspension, aggregates were produced consisting of both bacteria and gamma-FeOOH particles. Recently, we showed that the production of secondary minerals (GR1 vs. magnetite) was dependent on bacterial cell density and not only on iron reduction rates. Thus, gamma-FeOOH and S. putrefaciens aggregation pattern was suggested as the main mechanism driving mineralization. In this study, lepidocrocite bioreduction experiments, in the presence of anthraquinone disulfonate, were conducted by varying the [cell]/[lepidocrocite] ratio in order to determine whether different types of aggregate are formed, which may facilitate precipitation of GR1 as opposed to magnetite. Confocal laser scanning microscopy was used to analyze the relative cell surface area and lepidocrocite concentration within the aggregates and captured images were characterized by statistical methods for spatial data (i.e. variograms). These results suggest that the [cell]/[lepidocrocite] ratio influenced both the aggregate structure and the nature of the secondary iron mineral formed. Subsequently, a [cell]/[lepidocrocite] ratio above 1 x 10(7) cells mmol(-1) leads to densely packed aggregates and to the formation of GR1. Below this ratio, looser aggregates are formed and magnetite was systematically produced. The data presented in this study bring us closer to a more comprehensive understanding of the parameters governing the formation of minerals in dense bacterial suspensions and suggest that screening mineral-bacteria aggregate structure is critical to understanding (bio)mineralization pathways. PMID:20398066

Zegeye, A; Mustin, C; Jorand, F

2010-04-12

25

Radionuclide Incorporation in Secondary Crystalline Minerals from Chemical Weathering of Waste Glasses  

SciTech Connect

Data from corrosion and radionuclide sequestration studies on two waste glasses indicated chemical weathering resulted in the formation of zeolite minerals such as herschelite and analcime. We also found that these minerals incorporated {approx}8 - 22%, {approx}1- 13% and {approx}8 - 25% of spiked 125-I, 99-Tc, and 75-Se respectively. Increasing concentrations of radionuclides in spike solution resulted in higher degree of sequestration as observed by significantly higher proportion of stable isotopes ({approx}70 - 95% I, {approx}58 - 100% Re, and {approx}100% Se) in secondary minerals. The radionuclide incorporation mechanisms for these minerals appear to be mainly isomorphic substitution of Se and Re in tetrahedral sites and iodide substitution for framework oxygen.

Mattigod, Shas V.; Serne, R JEFFREY.; McGrail, B PETER.; Legore, Virginia L.

2002-09-01

26

Mutual replacement reactions in alkali feldspars I: microtextures and mechanisms  

Microsoft Academic Search

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

Ian Parsons; Martin R. Lee

2009-01-01

27

Hydrothermal Alteration in the PACMANUS Hydrothermal Field: Implications From Secondary Mineral Assemblages and Mineral Chemistry, OPD Leg 193  

NASA Astrophysics Data System (ADS)

Leg 193 of the Ocean Drilling Program investigated the subsurface nature of the active PACMANUS hydrothermal field in the Manus backarc basin near Papua New Guinea. Drilling in different areas on the felsic neovolcanic Pual Ridge, including the high-temperature black smoker complex of Roman Ruins and the low-temperature Snowcap site with diffusive discharge yielded a complex alteration history with a regional primary alteration being overprinted by a secondary mineralogy. The intense hydrothermal alteration at both sites shows significant differences in the secondary mineralogy. At Roman Ruins, the upper 25 m of hydrothermally altered rocks are characterized by a rapid change from secondary cristobalite to quartz, implying a high temperature gradient. From 10 to 120 mbsf the clay mineralogy is dominated by illite and chlorite. The chlorite formation temperature calculated from oxygen isotope data lies at 250° C in 116 mbsf which is similar to the present fluid outflow temperatures of 240-250° C (Douville et al., 1999, Geochim. Cosmochim. Acta, 63, 627-643). Drilling in the Snowcap field recovered evidence for several stages of hydrothermal alteration. Between 50 and 150 mbsf, cristobalite and chlorite are the most abundant alteration minerals while hydrothermal pyrophyllite becomes abundant in some places At 67 mbsf, the isotopic composition of pyrophyllite gives a temperature for ist formation at 260° C whereas at 77 and 116 mbsf the pyrophyllite displays the highest temperatures of formation (>300° C). These temperatures are close to the maximum measured borehole temperatures of 313° C. The appearance of assemblages of chlorite, chlorite-vermiculite, chlorite-vermiculite-smectite and illite-smectite as well as the local development of corrensite below 150 mbsf suggests that the alteration at Snowcap may be more complex than that beneath Roman Ruins. Detailed geochemical studies of the authigenic clay mineral phases will provide further insights into the chemical changes due to hydrothermal alteration.

Lackschewitz, K. S.; Kummetz, M.; Kummetz, M.; Ackermand, D.; Botz, R.; Devey, C. W.; Singer, A.; Stoffers, P.

2001-12-01

28

Alteration Products and Secondary Minerals in Martian Meteorite Allan Hills 84001  

NASA Astrophysics Data System (ADS)

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

29

Strontium Isotopes in Secondary Silicate Minerals Produced During Paleogroundwater Flow, Socorro, New Mexico  

NASA Astrophysics Data System (ADS)

Physical microsampling of silicate alteration phases produced during past episodes of groundwater flow, combined with Sr isotopic data, can potentially be used to determine the age of the alteration phases and to define paleogroundwater flow paths. Recent studies of the K-metasomatized, mid-Tertiary Lemitar Tuff near Socorro, central New Mexico (Fritz and Farmer, Chem, Geol., 2006) suggested that secondary adularia produced during metasomatism may record the original Sr isotopic compositions of altering fluids, the later providing information regarding the source of the solutes in the fluids. Here we expand our microsampling of secondary minerals in the altered Lemitar Tuff to a wider geographic area with the intent of determining if spatial variations in fluid Sr isotopic compositions are recorded in these minerals and if these variations can be used prescribe the direction of paleogroundwater flow. Samples were obtained of K-metasomatized tuff and overlying Popotosa Conglomerate along along an ~40 km transect through the entire region of alteration from potential recharge area in Precambrian granitic rocks of the Magdalena Mountains to the west, and discharge region in similar rocks some 4 km to the east. Most of the new adularia microsamples plot on a steeper errorchron (~12 m.y.) with lower apparent initial ratios (~0.711) than determined for the adularia samples analyzed by Fritz and Farmer (2006) (~7 m.y., ~0.721), regardless of geographic position. Unlike the samples obtained in the early study, our new microsamples contain varying proportions of secondary clay minerals, which are difficult to avoid during sampling. Clay mineral-rich adularia microsamples have higher Sr contents (100 ppm) and lower measured 87Sr/86Sr (~0.711) than their clay poor counterpart, suggesting that Sr -errorchron" may be a mixing line between a high Rb/Sr, high 87Sr/86Sr adularia and low Rb/Sr, low 87Sr/86Sr clay minerals. If so, then the clay minerals must either have formed at later time than adularia and incorporated Sr from a fluid containing solely tuff-derived Sr, or the Sr incorporated into clay minerals must have come solely from altering, low 87Sr/86Sr, igneous plagioclase, unlike the adularia. In either case, the intimate association between clay minerals and adularia, and differences in either the timing or mode of their crystallization, renders it difficult to extract with our current methodology unambiguous information regarding the Sr isotopic compositions of the K-metasomatizing fluids.

Farmer, G. L.; Rougvie, J.; Szilvagyi, E.

2008-12-01

30

Form and composition of secondary mineralization in fractures in Columbia River basalts  

SciTech Connect

Examination of basalt alteration rinds suggests that pyroxene is altered, along with mesostasis, from the inception of hydrothermal alteration along cooling fractures in Columbia River basalts. The only phyllosilicate secondary mineral in fractures is trioctahedral smectite of Fe-saponite composition, throughout the examined thickness of the basalt column. This smectite is compositionally distinct from the minor amounts of mesostasis smectite found in otherwise unaltered outcrop samples of basalt.

McKinley, J.P.; Rawson, S.A.; Horton, D.G.

1986-05-01

31

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 ...

32

Texture and microtexture studies in different types of cast irons  

Microsoft Academic Search

Drum and disk brake for trucks are important applications for cast irons. In the design of these components the low cycle fatigue strength is a critical attribute for material selection. It is known that fatigue strength is closely related to microtexture and grain boundary structure. In the present study, these two significant microstructure factors were evaluated for three types of

M. F. de Campos; L. C. Rolim Lopes; P. Magina; F. C. Lee Tavares; C. T. Kunioshi; H. Goldenstein

2005-01-01

33

Microtextural controls of weathering of perthitic alkali feldspars  

Microsoft Academic Search

The relationship between the microtexture and dissolution behaviour of fresh, HF acid-etched and naturally weathered alkali feldspar phenocrysts from the Lower Devonian Shap granite has been investigated by SEM and TEM. A novel resin impregnation technique has revealed the three dimensional shape and interconnectivity of etch pits beneath the weathered crystal surface. Further electron microscope work suggests that Shap phenocrysts

Martin R. Lee; Ian Parsons

1995-01-01

34

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

35

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

36

Cinacalcet for secondary hyperparathyroidism: From improved mineral levels to improved mortality?  

PubMed

Secondary hyperparathyroidism is an almost inevitable complication of advanced kidney failure. The introduction of the calcimimetic cinacalcet for the treatment of secondary hyperparathyroidism in patients on dialysis was based on its ability to reduce elevated levels of parathyroid hormone (PTH). Subsequent clinical studies confirmed the beneficial effects of cinacalcet on biochemical parameters reflecting mineral disturbances and bone disease. In this review we summarise the impact of cinacalcet on biochemical, intermediate and clinical outcomes. We also present previously unpublished mineral metabolism data from 144 Dutch dialysis patients treated with cinacalcet who participated in the pan-European ECHO observational study. Although secondary hyperparathyroidism tended to be more severe in our Dutch cohort, compared with the entire ECHO cohort, cinacalcet was nevertheless effective in reducing PTH in these patients. Two recent clinical studies evaluated, respectively, the efficacy of cinacalcet in improving the intermediate endpoint of cardiovascular calcifications (ADVANCE trial), and its impact on clinical outcomes, including all-cause mortality and cardiovascular events (EVOLVE trial). The ADVANCE trial provided evidence that cinacalcet may indeed improve calcification in both large arteries and cardiac valves. The EVOLVE trial, however, did not meet its clinical primary endpoint (time to all-cause mortality, myocardial infarction, hospitalisation for unstable angina, heart failure or a peripheral vascular event), although secondary and sensitivity analysis suggested a beneficial effect. The clinical implications of these important studies are also addressed in this review. PMID:24038560

Vervloet, M G; du Buf-Vereijken, P W G; Potter van Loon, B-J; Manamley, N; Reichert, L J M; Smak Gregoor, P J H

2013-09-01

37

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

NASA Astrophysics Data System (ADS)

Structural relations between secondary tungsten minerals with general composition Ax[(W,Fe)(O,OH)3]·yH2O are described. Phyllotungstite (A=predominantly Ca) is hexagonal, a=7.31(3)Å, c=19.55(1)Å, space group P63/mmc. Pittongite, a new secondary tungsten mineral from a wolframite deposit near Pittong in Victoria, southeastern Australia (A=predominantly Na) is hexagonal, a=7.286(1)Å, c=50.49(1)Å, space group P-6m2. The structures of both minerals can be described as unit-cell scale intergrowths of (111)py pyrochlore slabs with pairs of hexagonal tungsten bronze (HTB) layers. In phyllotungstite, the (111)py blocks have the same thickness, 6 Å, whereas pittongite contains pyrochlore blocks of two different thicknesses, 6 and 12 Å. The structures can alternatively be described in terms of chemical twinning of the pyrochlore structure on (111)py oxygen planes. At the chemical twin planes, pairs of HTB layers are corner connected as in hexagonal WO3.

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

2006-12-01

38

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

SciTech Connect

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

Grey, Ian E. [CSIRO Minerals, Box 312, Clayton South, Vic. 3169 (Australia)]. E-mail: ian.grey@csiro.au; Birch, William D. [Geosciences Department, Museum Victoria, GPO Box 666, Melbourne, Vic. 3001 (Australia); Bougerol, Catherine [Equipe CEA-CNRS NPSC SP2M/DRFMC/CEA, 17 rue des Martyrs, 38054 Grenoble (France); Mills, Stuart J. [CSIRO Minerals, Box 312, Clayton South, Vic. 3169 (Australia); Geosciences Department, Museum Victoria, GPO Box 666, Melbourne, Vic. 3001 (Australia)

2006-12-15

39

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

Microsoft Academic Search

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

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

2009-01-01

40

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

PubMed

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

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

2010-09-09

41

Minerals  

MedlinePLUS

... commercials for breakfast cereal always mention vitamins and minerals ? But when you think of minerals, food isn't the first thing that comes to mind. Aren't minerals something you find in the earth, like iron ...

42

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

43

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.

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

44

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

Microsoft Academic Search

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

Rolf L. Romer; Norbert Nowaczyk; Richard Wirth

2007-01-01

45

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

NASA Astrophysics Data System (ADS)

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

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

1995-09-01

46

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.

47

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

SciTech Connect

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

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

2001-04-29

48

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

49

Diagenesis of basalts from the Pasco Basin, Washington. I. Distribution and composition of secondary mineral phases  

SciTech Connect

The principal components of secondary mineral assemblages found in Pasco Basin basalts are iron-rich smectite (nontronite), clinoptilolite, and silica. Silica occurs as quartz, cristobalite, tridymite, and opal-CT. Extractable iron within the nontronite suggests the presence of an iron-bearing oxyhydroxide phase intercalated with the nontronite. Other components present in minor or trace amounts are mordenite, celadonite, apatite, pyrite, phillipsite, gypsum, crionite, and chabazite. The generalized precipitation sequence with time and/or depth was found to be clay (usually nontronite) ..-->.. clinoptilolite ..-->.. silica and/or clay. Nontronite, the first phase to form, is present at nearly all sampled depths. Clinoptilolite is apparently restricted to depths below about 350 m. Quartz is ubiquitous whereas opal and cristobalite appear to be abundant only below 600 m. Mordenite occurs only at depths below about 900 m, which correlates roughly with the first occurrence of dissolution-etched clinoptilolite. These observations as well as comparisons with data on secondary minearl assemblages from other basaltic and felsic systems suggest that the geochemical evolution of Pasco Basin basalts probably occurred under conditions similar to those existing today.

Benson, L.V.; Teague, L.S.

1982-01-01

50

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

NASA Astrophysics Data System (ADS)

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

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

2005-02-01

51

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

52

EBSD analysis of the microtexture of Ba-hexaferrite samples  

NASA Astrophysics Data System (ADS)

The microtexture of differently prepared Ba-hexaferrite samples is investigated by means of electron backscatter diffraction (EBSD). Kikuchi patterns are obtained with a high image quality, enabling a spatial resolution of the EBSD maps of about 20 nm. The spatially highly resolved EBSD mappings provide additional information (individual grain orientation, misorientation angles, grain size distribution) as compared to the standard analysis techniques, which can contribute to an optimization of the growth process. Furthermore, as the crystallographic orientation of each grain is known, an exact analysis of the grain aspect ratio becomes possible which provides further insight to the microstructural dependence of the magnetic properties of ferrites.

Koblischka-Veneva, A.; Koblischka, M. R.; Schmauch, J.; Chen, Y.; Harris, V. G.

2010-01-01

53

Minerals  

NSDL National Science Digital Library

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

Fichter, Lynn S.

2000-09-13

54

Minerals  

NSDL National Science Digital Library

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

Walls, Mrs.

2011-01-30

55

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

SciTech Connect

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

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

1998-12-01

56

Sorption and Redox Reactions of As(III) and As(V) within Secondary Mineral Coatings on Aquifer Sediment Grains.  

PubMed

Important reactive phenomena that affect the transport and fate of many elements occur at the mineral-water interface (MWI), including sorption and redox reactions. Fundamental knowledge of these phenomena are often based on observations of ideal mineral-water systems, for example, studies of molecular scale reactions on single crystal faces or the surfaces of pure mineral powders. Much less is understood about MWI in natural environments, which typically have nanometer to micrometer scale secondary mineral coatings on the surfaces of primary mineral grains. We examined sediment grain coatings from a well-characterized field site to determine the causes of rate limitations for arsenic (As) sorption and redox processes within the coatings. Sediments were obtained from the USGS field research site on Cape Cod, MA, and exposed to synthetic contaminated groundwater solutions. Uptake of As(III) and As(V) into the coatings was studied with a combination of electron microscopy and synchrotron techniques to assess concentration gradients and reactive processes, including electron transfer reactions. Transmission electron microscopy (TEM) and X-ray microprobe (XMP) analyses indicated that As was primarily associated with micrometer- to submicrometer aggregates of Mn-bearing nanoparticulate goethite. As(III) oxidation by this phase was observed but limited by the extent of exposed surface area of the goethite grains to the exterior of the mineral coatings. Secondary mineral coatings are potentially both sinks and sources of contaminants depending on the history of a contaminated site, and may need to be included explicitly in reactive transport models. PMID:24041305

Singer, David M; Fox, Patricia M; Guo, Hua; Marcus, Matthew A; Davis, James A

2013-09-27

57

Design and Fabrication of Micro-textures for Inducing a Superhydrophobic Behavior on Hydrophilic Materials  

Microsoft Academic Search

Artificial superhydrophobic surfaces are typically fabricated by tuning the surface roughness of intrinsically hydrophobic surfaces. We here report the design and fabrication of micro-textures for inducing a superhydrophobic behavior on intrinsically hydrophilic hydrogen-terminated Si surfaces with an intrinsic water contact angle of about 74 degree. The micro-textures consist of overhang structures with well-defined geometries fabricated by microfabrication technologies, which provide

Di Gao; Liangliang Cao; Anmin Cao; Hsin-Hua Hu

2008-01-01

58

Solution spraying of poly(methyl methacrylate) blends to fabricate microtextured, superoleophobic surfaces  

Microsoft Academic Search

We describe a simple technique to prepare superhydrophobic and superoleophobic microtextured surfaces by spray coating a blend of poly(methyl methacrylate) (PMMA) and the low surface energy molecule 1H,1H,2H,2H-heptadecafluorodecyl polyhedral oligomeric silsesquioxane (fluorodecyl POSS, ?sv?10mN\\/m) using an air brush with a pressurized nitrogen stream. Scanning electron micrographs show the formation of microtextured surfaces possessing re-entrant curvature; a critical feature for obtaining

Siddarth Srinivasan; Shreerang S. Chhatre; Joseph M. Mabry; Robert E. Cohen; Gareth H. McKinley

2011-01-01

59

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

SciTech Connect

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

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

1998-10-23

60

Surface exploration of Amphibalanus amphitrite cyprids on microtextured surfaces.  

PubMed

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

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

2011-04-01

61

Change in the dissolution rates of alkali feldspars as a result of secondary mineral precipitation and approach to equilibrium  

Microsoft Academic Search

Reaction rates of congruent and incongruent dissolution of sanidine in NaHCO3 solution (0.1 m) and albite in KHCO3 solution (0.1 m) as well as the reaction rates of precipitation of secondary minerals (analcime and sanidine) have been measured at 300°C, 88 bars, and pH 9. At congruent stage, the reaction rates change, as equilibrium is approached, according to the following

Victor A. Alekseyev; Ludmila S. Medvedeva; Nina I. Prisyagina; Sergey S. Meshalkin; Aleksey I. Balabin

1997-01-01

62

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

Microsoft Academic Search

Experiments were conducted in fiscal year 1998 by Pacific Northwest National Laboratory to evaluate potential incorporation of radionuclides in secondary mineral phases that form from weathering;\\u000a vitrified nuclear waste glasses. These experiments were conducted as part of the Immobilized Low-;\\u000a Activity Waste-Petiormance Assessment (ILAW-PA) to generate data on radionuclide mobilization and;\\u000atransport in a near-field enviromnent of disposed vitrified wastes.;

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

1998-01-01

63

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

64

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

USGS Publications Warehouse

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

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

2009-01-01

65

Using SEM and EDS Data to Evaluate the Evolution of Secondary Minerals in Incipiently Altered Volcanic Rocks of Southeast Guatemala  

NASA Astrophysics Data System (ADS)

Secondary processes such as weathering and hydrothermal alteration are known to affect the geochemistry of volcanic rocks following emplacement. Data suggest that even at the earliest stages of these processes, secondary products such as clays and zeolites develop. These secondary minerals may serve as the host for trace elements that are mobilized from the glassy matrix and primary minerals. Phenocrysts exhibiting different degrees of weathering were compared using EDS scans and secondary-electron imaging, in order to better characterize the secondary products, and their role in element mobility. Three geologic units from Tecuamburro volcanic complex in southeast Guatemala were sampled to examine secondary mineral formation in incipiently weathered rocks. The samples range in age from 0.8 to 2.6 Ma and in composition from basalt to dacite. Samples are petrographically characterized by plagioclase, pyroxene, and oxide phenocrysts, and a glassy groundmass containing microlites similar to the phenocrysts. Each hand sample (appx. 10-20cm diameter) was divided into 3 zones: core, intermediate, and rind. In core plagioclases, EDS data show no obvious variation in Ca-Si ratios across the grains. Accessory phases such as phosphates and Fe-Ti oxides are also present, and randomly distributed in the core plagioclase grains. Secondary-electron images of a plagioclase from the core reveal fractures already filled with secondary material (e.g. clays). Core pyroxenes contain Fe-Ti oxides both randomly distributed throughout the grains, and along fractures and cleavages. In the intermediate zone, the edges of plagioclase grains are depleted in Ca relative to the grain centers. Fractures in the intermediate plagioclases contain Fe-Ti oxides along with clays, while pyroxene fractures contain both Fe-Ti oxides and phosphates. In the rind, plagioclase Ca-Si ratios vary greatly within individual grains. These variations are interpreted as secondary when contrasted with the homogenous core plagioclase grains. Fractures in rind pyroxenes contain kaolinite, and Fe-Ti oxides are abundant in fractures and along grain edges. Phosphates in the rind are uncommon, and are not associated with either plagioclase or pyroxene. Secondary images of a rind plagioclase show etch pits, clay minerals in fractures and on the surface, and possible zeolites along large fracture walls. The nature and abundance of secondary material does increase within the profile of these incipiently weathered rocks. However, even the relatively "fresh" cores contain clays and oxides in fractures. Ca-Si ratios in plagioclase grains dramatically change from core to rind, and strongly suggest alteration. Clays, oxides, and phosphates are common in fractures and edges of phenocrysts from the intermediate zone. Fractures in the grains from the rind contain abundant clays and oxides. The occurrence of secondary phases even in the least altered samples leads us to believe that trace elements may also be mobile at these early stages of alteration. Further study of the early-forming secondary phases will clarify their role in the mobility of these elements.

Wade, J. A.; Patino, L. C.; Velbel, M. A.

2001-12-01

66

Secondary ion mass spectrometric investigation of penetration of coconut and mineral oils into human hair fibers: relevance to hair damage.  

PubMed

An attempt has been made to show the difference in the penetrability of coconut oil and mineral oil in human hair. We have used secondary ion mass spectrometry (SIMS) in combination with a time-of-flight (TOF) mass spectrometer. Characteristic ions formed by the pure components when bombarded with gallium ions have been identified with their m/z values. The distribution of the ion, characteristic of the particular treatment, has been established in the cross sections of hair treated with coconut and mineral oils. The results show that coconut oil penetrates the hair shaft while mineral oil does not. The difference may be due to the polarity of the coconut oil compared to the nonpolar nature of the mineral oil. The affinity of the penetrant to the protein seems to be the cause for this difference in their behavior. This study also indicates that the swelling of hair is limited by the presence oil. Since the process of swelling and deswelling of hair is one of the causes of hair damage by hygral fatigue, coconut oil, which is a better penetrant than mineral oil, may provide better protection from damage by hygral fatigue. PMID:11413497

Ruetsch, S B; Kamath, Y K; Rele, A S; Mohile, R B

67

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

68

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

PubMed

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

Méndez-Hernández, J E; Ramírez-Vives, F; Solís-Oba, M; Solís-Oba, A; Sobrino-Figueroa, A S; Loera, O

2012-12-18

69

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

70

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

71

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

72

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

NASA Astrophysics Data System (ADS)

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

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

2011-12-01

73

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

NASA Astrophysics Data System (ADS)

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

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

2004-07-01

74

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

NASA Astrophysics Data System (ADS)

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

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

2013-02-01

75

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

76

Secondary Recovery: Change of the Viscosity and Compressibility of Mineral Oils by Dissolved Gas.  

National Technical Information Service (NTIS)

Secondary and tertiary oil recovery methods for an enhancement of the production rate are mostly based on a reduction of the mobility ratio water/oil. This can be achieved e.g. by lowering of the oil viscosity by heat or dissolved gases. To investigate th...

E. Kuss H. Killesreiter

1981-01-01

77

Weathering of Rocks in Gusev Crater Inferred From Correlations Between Primary and Secondary Fe-bearing Minerals Identified by Spirit's Moessbauer Spectrometer  

NASA Astrophysics Data System (ADS)

The Mars Exploration Rover Spirit has by now identified more than six different rock classes during its traverse from the landing site across the plains and into the Columbia Hills. The classification is based on the rocks' chemical composition, and can be further divided into several subclasses on the basis of mineralogical composition from Moessbauer spectra. Rocks in Gusev Crater show various degrees of alteration, both between different rock classes and within individual rock classes. Fe3+/FeTotal ratios determined by Moessbauer spectroscopy were used as a measure of the alteration of individual rocks. Spirit's Moessbauer spectrometer identified eight different Fe-bearing mineral phases: The primary minerals olivine, pyroxene, ilmenite, and magnetite as well as the secondary minerals hematite, goethite, an unspecified nanophase ferric oxide phase, and a ferric sulfate. For all rock and soil targets the amounts of Fe in individual primary minerals were plotted against Fe3+/FeTotal ratios, and the amounts of Fe in individual secondary minerals. A good correlation is observed between olivine and Fe3+/FeTotal in all rock and soil classes, whereas a good correlation between pyroxene and Fe3+/FeTotal is only observed in pervasively altered rocks in the Columbia Hills. Ilmenite and magnetite show no apparent correlation with Fe3+/FeTotal ratios. Plots between primary and secondary minerals indicate that Fe from olivine or pyroxene is altered to a range of secondary phases rather than one individual secondary mineral. However, remarkable correlations exist between olivine and hematite in Pot of Gold Class rocks and between magnetite and goethite in Clovis Class rocks. The results suggest that the slow alteration of olivine in rocks and soils is the only currently active alteration process in Gusev Crater.

Schroeder, C.; Klingelhoefer, G.; Morris, R. V.; Rodionov, D. S.

2006-12-01

78

Characterization of Microstructure, Texture, and Microtexture in Near-Alpha Titanium Mill Products  

NASA Astrophysics Data System (ADS)

Microstructure, texture, and microtexture in Ti-6Al-2Sn-4Zr-2Mo-0.1Si billet/bar of three different diameters (57, 152, and 209 mm) were quantified using backscattered electron imaging and electron backscatter diffraction. All three billets exhibited a microstructure comprising a large fraction (?70 pct) of primary alpha particles, the average size of which decreased and aspect ratio increased with increasing reduction/decreasing billet diameter, or trends suggestive of low final hot working temperatures and/or slow cooling rates after deformation. Appreciable radial variations in the volume fraction and aspect ratio of alpha particles were noticeable only for the smallest-diameter billet. Alpha-phase textures were typical of axisymmetric deformation, but were relatively weak (~3× random) for all billet diameters. By contrast, bands of microtexture, which were multiple millimeters in length along the axial direction, were relatively strong for all of the materials. The intensity and radial thickness of the bands tended to decrease with decreasing billet diameter, thus indicating the important influence of imposed strain on the elimination of microtexture and the possible influence of surface preform microstructure following the beta quench on the evolution of microstructure and microtexture.

Pilchak, A. L.; Szczepanski, C. J.; Shaffer, J. A.; Salem, A. A.; Semiatin, S. L.

2013-06-01

79

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

National Technical Information Service (NTIS)

We describe a simple technique to prepare superhydrophobic and superoleophobic micro-textured surfaces by spray coating a blend of poly(methyl methacrylate) (PMMA) and the low surface energy molecule 1H,1H,2H,2H- heptadecafluorodecyl polyhedral oligomeric...

G. H. McKinley J. M. Mabry R. E. Cohen S. Srinivasan S. S. Chhatre

2011-01-01

80

Characterization of Microstructure, Texture, and Microtexture in Near-Alpha Titanium Mill Products  

NASA Astrophysics Data System (ADS)

Microstructure, texture, and microtexture in Ti-6Al-2Sn-4Zr-2Mo-0.1Si billet/bar of three different diameters (57, 152, and 209 mm) were quantified using backscattered electron imaging and electron backscatter diffraction. All three billets exhibited a microstructure comprising a large fraction (?70 pct) of primary alpha particles, the average size of which decreased and aspect ratio increased with increasing reduction/decreasing billet diameter, or trends suggestive of low final hot working temperatures and/or slow cooling rates after deformation. Appreciable radial variations in the volume fraction and aspect ratio of alpha particles were noticeable only for the smallest-diameter billet. Alpha-phase textures were typical of axisymmetric deformation, but were relatively weak (~3× random) for all billet diameters. By contrast, bands of microtexture, which were multiple millimeters in length along the axial direction, were relatively strong for all of the materials. The intensity and radial thickness of the bands tended to decrease with decreasing billet diameter, thus indicating the important influence of imposed strain on the elimination of microtexture and the possible influence of surface preform microstructure following the beta quench on the evolution of microstructure and microtexture.

Pilchak, A. L.; Szczepanski, C. J.; Shaffer, J. A.; Salem, A. A.; Semiatin, S. L.

2013-11-01

81

Secondary mineralization pathways induced by dissimilatory iron reduction of ferrihydrite under advective flow  

Microsoft Academic Search

Iron (hydr)oxides not only serve as potent sorbents and repositories for nutrients and contaminants but also provide a terminal electron acceptor for microbial respiration. The microbial reduction of Fe (hydr)oxides and the subsequent secondary solid-phase transformations will, therefore, have a profound influence on the biogeochemical cycling of Fe as well as associated metals. Here we elucidate the pathways and mechanisms

Colleen M. Hansel; Shawn G. Benner; Jim Neiss; Alice Dohnalkova; Ravi K. Kukkadapu; Scott Fendorf

2003-01-01

82

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

NASA Astrophysics Data System (ADS)

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

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

2013-10-01

83

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

NASA Astrophysics Data System (ADS)

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

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

2013-10-01

84

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

Microsoft Academic Search

Metal cycling via physical and chemical weathering of discrete sources (copper mines) and regional (non-point) sources (sulfide-rich shale) is evaluated by examining the mineralogy and chemistry of weathering products in Great Smoky Mountains National Park, Tennessee, and North Carolina, USA. The elements in copper mine waste, secondary minerals, stream sediments, and waters that are most likely to have negative impacts

Jane M. Hammarstrom; Robert R. Seal II; Allen L. Meier; John C. Jackson

2003-01-01

85

Mineral species as functions of p H and oxidation-reduction potentials, with special reference to the zone of oxidation and secondary enrichment of sulphide ore deposits  

Microsoft Academic Search

A series of diagrams has been prepared showing some stability and solubility relations among lead, zinc, and copper minerals found in the zones of oxidation and secondary enrichment of sulphide ore deposits. The stability and solubility relations are expressed as functions of p H and oxidation-reduction potential. These diagrams show theoretical equilibrium relations, and are sufficiently similar to relations found

Robert M. Garrels

1954-01-01

86

Mineral association changes the secondary structure and dynamics of murine amelogenin.  

PubMed

Amelogenin is one of the key protein constituents responsible for the exquisite organization of the calcium phosphate crystals in enamel. Amelogenin forms into nanospheres in solution, while its association with hydroxyapatite is also essential to enamel development. Structural information of full-length amelogenin in either of these physiologically important forms has the potential to provide mechanistic information; however, these data are limited because of the difficulty of determining the structure of large protein complexes and proteins bound to surfaces. To obtain structural insights into amelogenin during these early stages of enamel development, we used a lysine-specific (13)C-, (15)N-labeled sample of murine amelogenin to provide insight into the structure of the hydroxyapatite (HAP)-binding domains of the protein. A combination of one-and two-dimensional solid-state NMR experiments was used to obtain molecular-level insights into the secondary structure and dynamics of full-length amelogenin within a nanosphere-gel and on the surface of HAP. Regions of amelogenin that appear to be primarily random coil in the nanosphere-gel adopt a ?-strand structure and are less mobile with HAP binding, indicative of a structural switch upon binding that may be important in the role of amelogenin in enamel development. PMID:24130249

Lu, J X; Xu, Y S; Buchko, G W; Shaw, W J

2013-11-01

87

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

NASA Astrophysics Data System (ADS)

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

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

2013-01-01

88

Transforming growth factor-beta3-loaded microtextured membranes for skin regeneration in dermal wounds  

Microsoft Academic Search

Adverse effects of wound healing, such as excessive scar tissue formation, wound contraction, or nonhealing wounds represent a major clinical issue in today's healthcare. Transforming growth factor (TGF)-beta3 has specifically been implicated in wound healing. Our hypothesis was that local administration of TGF-beta3 to excisional dermal wounds would diminish wound contraction and scar formation. Microtextured wound covers, containing different concentrations

D. P. P. Vooijs; X. F. Walboomers; J. A. T. C. Parker; J. W. Von den Hoff; J. A. Jansen

2004-01-01

89

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

90

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

2012-06-15

91

Metasomatic mechanism of weathering-pedogenesis of carbonate rocks: I. Mineralogical and micro-textural evidence  

Microsoft Academic Search

On the basis of mineralogical, geochemical and micro-textural studies of the typical sections of the red weathering crust\\u000a of carbonate rocks in the subtropical karst areas of Guizhou Province and Guangxi Autonomous Region, we have found, either\\u000a on a microscopic or on a macroscopical scale and in different positions of the sections, the most direct and most important\\u000a mineralogical and

Zhu Lijun; Li Jingyang

2002-01-01

92

Secondary tungsten minerals in quartz veins in the Ishidera area, Wazuka, Kyoto Prefecture, Japan: anthoinite, mpororoite, and Fe-free hydrokenoelsmoreite  

NASA Astrophysics Data System (ADS)

Secondary minerals of tungsten that are the products of alteration of scheelite present in quartz veins in the Ishidera area, Wazuka, Kyoto Prefecture, have been examined using XRD, SEM-EDS, EPMA, and XRF. From the results, three tungsten minerals were identified: anthoinite, mpororoite, and hydrokenoelsmoreite. The two former minerals have not been reported to be found in Japan. This is, therefore, the first discovery of anthoinite and mpororoite in Japan. The two minerals form a white powdery mixture with pseudomorphing scheelite. Chemical analysis of the mixture shows that the Al/W ratio is approximate to 1 and that the Fe2O3 content is very low, suggesting that the ideal formulae of anthoinite and mpororoite are WAlO3(OH)3 and WAlO3(OH)3·2H2O, respectively, even though the original mpororoite had a high content of Fe2O3 substituting for Al2O3. In addition to these two minerals, another tungsten mineral was also found within the scheelite-pseudomorphs. It occurs as aggregates of regular octahedral crystals up to 50 ?m in length. The XRD data are in good agreement with those for hydrokenoelsmoreite, but chemical analysis shows that the major components are WO3, Al2O3, and H2O with no Fe2O3. Up to this time, only Fe-containing hydrokenoelsmoreite, once termed ferritungstite according to the old nomenclature, has been widely reported to be found in Japan. This paper is the first to report the occurrence of such an Fe-free hydrokenoelsmoreite in Japan. It is likely that these three secondary minerals of tungsten at Wazuka were formed in an environment where the supply of H2O and Al2O3 and the leaching of calcium ions from scheelite took place simultaneously. The source of Al is ascribed to the decomposition of muscovite in the quartz veins.

Shimobayashi, Norimasa; Ohnishi, Masayuki; Tsuruta, Kenji

93

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

Microsoft Academic Search

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

J. M. Hammarstrom; R SEALII; A. L. Meier; J. M. Kornfeld

2005-01-01

94

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

Microsoft Academic Search

Concentrations of ¹⁸O and deuterium in ground waters beneath the Handford Reservation, Washington State, suggest that the meteoric waters recharging the basalt aquifers have been progressively depleted in these isotopes since at least Pleistocene time. This conclusion is supported by oxygen-isotope analyses of low-temperature secondary minerals filing vugs and fractures in the basalts, which are used to approximate the ¹⁸O

J. R. Evans; W. C. Steinkampf; D. G. Horton; G. C. Solomon; L. D. White

1989-01-01

95

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

96

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

PubMed

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

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

2013-04-30

97

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

PubMed

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

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

2003-11-01

98

Chronic Increase of Bone Turnover Markers After Biliopancreatic Diversion is Related to Secondary Hyperparathyroidism and Weight Loss. Relation with Bone Mineral Density  

Microsoft Academic Search

Background  Biliopancreatic diversion (BPD) is the most effective bariatric procedure. Around 70% of these patients have secondary hyperparathyroidism\\u000a (SH) in the long term as a consequence of calcium and vitamin D malabsorption. This work was aimed to study the influence\\u000a of SH on bone turnover and its relationship with bone mineral density (BMD).\\u000a \\u000a \\u000a \\u000a \\u000a Methods  Bone turnover markers were determined in 63 BPD

José Antonio Balsa; José I. Botella-Carretero; Roberto Peromingo; Carmen Caballero; Teresa Muñoz-Malo; Juan J. Villafruela; Francisco Arrieta; Isabel Zamarrón; Clotilde Vázquez

2010-01-01

99

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

Microsoft Academic Search

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

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

2000-01-01

101

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

102

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

103

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

2005-01-01

104

Temporal patterns of net soil N mineralization and nitrification through secondary succession in the subtropical forests of eastern China  

Microsoft Academic Search

Linking temporal trends of soil nitrogen (N) transformation with shifting patterns of plants and consequently changes of litter\\u000a quality during succession is important for understanding developmental patterns of ecosystem function. However, the successional\\u000a direction of soil N mineralization and nitrification in relation to species shifts in the subtropical regions remains little\\u000a studied. In this study, successional patterns of net soil

En-Rong Yan; Xi-Hua Wang; Ming Guo; Qiang Zhong; Wu Zhou; Yong-Fu Li

2009-01-01

105

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

106

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

NASA Astrophysics Data System (ADS)

Yucca Mountain in southern Nevada is being evaluated as a potential site for the geological disposal of high-level nuclear waste. A reliable assessment of the future performance of the repository will require detailed paleohydrogeological information. Hydrogenic secondary minerals from the vadose zone of Yucca Mountain are being studied as paleohydrogeological indicators. A phenomenological model envisaging the deposition of secondary minerals by meteoric fluids infiltrating downward though the vadose zone was proposed in the reviewed paper. Our evaluation reveals that the model is not supported by empiric evidence reported in the paper.

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

2005-09-01

107

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

108

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

109

Lemon-flavored cod liver oil and a multivitamin-mineral supplement for the secondary prevention of otitis media in young children: pilot research.  

PubMed

We measured blood levels of fatty acids, vitamin A, and trace metals in children undergoing ambulatory surgery for placement of tympanostomy tubes and a comparison group having other ambulatory surgical procedures. We then performed a small, outpatient, secondary prevention study using nutritional supplements chosen on the basis of those blood levels. The study subjects had lower levels of red blood cell eicosapentaenoic acid (EPA) than did adult controls. Consistent with previous reports, the levels of vitamin A were < or = 40 microg/dL for 69% of our subjects, and the plasma selenium levels for children were lower than published values for adults. We then studied one otitis media (OM) season; 8 children (0.8 to 4.4 years of age) received 1 teaspoon of lemon-flavored cod liver oil (containing both EPA and vitamin A) and 1 half-tablet of a selenium-containing children's chewable multivitamin-mineral tablet per day. During this OM season, study subjects received antibiotics for OM for 12.3% +/- 13.4% (SD; p < .05) fewer days during supplementation than before supplementation. Larger, controlled trials are warranted to assess the utility of cod liver oil (of acceptable purity and taste) and a children's multivitamin-mineral preparation containing selenium, both for the prevention of OM and for the acceptance of delayed prescription of antibiotics for this disorder. PMID:12126022

Linday, Linda A; Dolitsky, Jay N; Shindledecker, Richard D; Pippenger, C E

2002-07-01

110

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

USGS Publications Warehouse

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

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

1989-01-01

111

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

PubMed

Microtexture and chemistry of implant surfaces are important variables for modulating cellular responses. Surface chemistry and wettability are connected directly. While each of these surface properties can influence cell response, it is difficult to decouple their specific contributions. To address this problem, the aims of this study were to develop a surface wettability gradient with a specific chemistry without altering micron scale roughness and to investigate the role of surface wettability on osteoblast response. Microtextured sandblasted/acid-etched (SLA, Sa = 3.1 ?m) titanium disks were treated with oxygen plasma to increase reactive oxygen density on the surface. At 0, 2, 6, 10, and 24 h after removing them from the plasma, the surfaces were coated with chitosan for 30 min, rinsed and dried. Modified SLA surfaces are denoted as SLA/h in air prior to coating. Surface characterization demonstrated that this process yielded differing wettability (SLA0 < SLA2 < SLA10 < SLA24) without modifying the micron scale features of the surface. Cell number was reduced in a wettability-dependent manner, except for the most water-wettable surface, SLA24. There was no difference in alkaline phosphatase activity with differing wettability. Increased wettability yielded increased osteocalcin and osteoprotegerin production, except on the SLA24 surfaces. mRNA for integrins ?1, ?2, ?5, ?1, and ?3 was sensitive to surface wettability. However, surface wettability did not affect mRNA levels for integrin ?3. Silencing ?1 increased cell number with reduced osteocalcin and osteoprotegerin in a wettability-dependent manner. Surface wettability as a primary regulator enhanced osteoblast differentiation, but integrin expression and silencing ?1 results indicate that surface wettability regulates osteoblast through differential integrin expression profiles than microtexture does. The results may indicate that both microtexture and wettability with a specific chemistry have important regulatory effects on osseointegration. Each property had different effects, which were mediated by different integrin receptors. PMID:22835642

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

2012-07-24

112

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

PubMed Central

Microtexture and chemistry of implant surfaces are important variables for modulating cellular responses. Surface chemistry and wettability are connected directly. While each of these surface properties can influence cell response, it is difficult to decouple their specific contributions. To address this problem, the aims of this study were to develop a surface wettability gradient with a specific chemistry without altering micron scale roughness and to investigate the role of surface wettability on osteoblast response. Microtextured sandblasted/acid-etched (SLA, Sa = 3.1 ?m) titanium disks were treated with oxygen plasma to increase reactive oxygen density on the surface. At 0, 2, 6, 10, and 24 h after removing them from the plasma, the surfaces were coated with chitosan for 30 min, rinsed and dried. Modified SLA surfaces are denoted as SLA/h in air prior to coating. Surface characterization demonstrated that this process yielded differing wettability (SLA0 < SLA2 < SLA10 < SLA24) without modifying the micron scale features of the surface. Cell number was reduced in a wettability-dependent manner, except for the most water-wettable surface, SLA24. There was no difference in alkaline phosphatase activity with differing wettability. Increased wettability yielded increased osteocalcin and osteoprotegerin production, except on the SLA24 surfaces. mRNA for integrins ?1, ?2, ?5, ?1, and ?3 was sensitive to surface wettability. However, surface wettability did not affect mRNA levels for integrin ?3. Silencing ?1 increased cell number with reduced osteocalcin and osteoprotegerin in a wettability-dependent manner. Surface wettability as a primary regulator enhanced osteoblast differentiation, but integrin expression and silencing ?1 results indicate that surface wettability regulates osteoblast through differential integrin expression profiles than microtexture does. The results may indicate that both microtexture and wettability with a specific chemistry have important regulatory effects on osseointegration. Each property had different effects, which were mediated by different integrin receptors.

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

2013-01-01

113

Evolution of microstructure, macrotexture and microtexture during hot rolling of Ti6A1-4V  

Microsoft Academic Search

The evolution of microstructure, macrotexture and microtexture during subtransus hot working of Ti-6A1-4V with two different types of transformed ? starting microstructures (lamellar colony, acicular\\/martensitic ?) was investigated. Globularization of the transformed microstructures required heavy rolling reductions or moderate reductions coupled with near transus post-rolling heat treatment. Despite the sluggish dynamic globularization kinetics, noticeable macrotexture changes were noted after low

P. Ari-Gur; S. L. Semiatin

1998-01-01

114

Lower Fibroblast Growth Factor 23 Levels in Young Adults With Crohn Disease as a Possible Secondary Compensatory Effect on the Disturbance of Bone and Mineral Metabolism.  

PubMed

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

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

2013-04-25

115

The efficacy of cinacalcet combined with conventional therapy on bone and mineral metabolism in dialysis patients with secondary hyperparathyroidism: a meta-analysis.  

PubMed

Cinacalcet, the first calcimimetic to be approved for the treatment of secondary hyperparathyroidism (SHPT) in the chronic kidney disease patients, offers a novel therapeutic approach to SHPT. The aim of this meta-analysis is to access the efficacy and safety of cinacalcet on bone and mineral metabolism disorders in the dialysis patients with SHPT. Randomized controlled trials on cinacalcet combined with vitamin D and/or phosphate binders in the dialysis patients with SHPT were identified in Pubmed, Sciencedirect, and the Cochrane library. Data were analyzed with RevMan software. We compared the proportion of patients achieving the biochemical targets recommended by the Kidney Disease Outcomes Quality Initiative (KDOQI) guidelines and the incidence of adverse events between the cinacalcet and control groups. Six trials involving 2,548 patients were included. A greater proportion of patients in the cinacalcet group compared with the conventional group achieved the KDOQI targets. The relative risks (RRs) were parathyroid hormone (PTH) (RR = 3.51, 95 % CI: 2.38-5.17), calcium (RR = 2.04, 95 % CI: 1.76-2.37), phosphorus (RR = 1.15, 95 % CI: 0.83-1.60), and calcium-phosphorus product (Ca × P) (RR = 1.41, 95 % CI: 1.18-1.69), the number of patients simultaneously achieving the KDOQI targets for PTH + Ca × P was also greater (RR = 3.89, 95 % CI: 2.36-6.41), with p < 0.001 for each. The most common adverse events were nausea, vomiting, diarrhea, and hypocalcemia, which had a higher incidence in the cinacalcet group, but were usually mild to moderate in severity and transient. Compared with conventional therapy, treatment with cinacalcet results in more patients achieving KDOQI targets and offers an effective and safety therapeutic option for controlling mineral and bone disorders in the dialysis patients with SHPT. PMID:22669774

Li, Dan; Shao, Leping; Zhou, Haiyan; Jiang, Wei; Zhang, Wei; Xu, Yan

2012-06-06

116

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.

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

2008-01-01

117

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

2012-12-04

118

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

119

Cryptic microtextures and geological histories of K-rich alkali feldspars revealed by charge contrast imaging  

NASA Astrophysics Data System (ADS)

Charge contrast imaging in the scanning electron microscope can provide new insights into the scale and composition of alkali feldspar microtextures, and such information helps considerably with the interpretation of their geological histories and results of argon isotope thermochronological analyses. The effectiveness of this technique has been illustrated using potassium-rich alkali feldspars from the Dartmoor granite (UK). These feldspars contain strain-controlled lamellar crypto- and microperthites that are cross-cut by strain-free deuteric microperthites. The constituent albite- and orthoclase-rich phases of both microperthite generations can be readily distinguished by atomic number contrast imaging. The charge contrast results additionally show that sub-micrometre-sized albite `platelets' are commonplace between coarser exsolution lamellae and occur together to make cryptoperthites. Furthermore, charge contrast imaging reveals that the orthoclase-rich feldspar is an intergrowth of two phases, one that is featureless with uniform contrast and another that occurs as cross-cutting veins and grains with the {110} adularia habit. Transmission electron microscopy shows that the featureless feldspar is tweed orthoclase, whereas the veins and euhedral grains are composed of irregular microcline that has formed from orthoclase by `unzipping' during deuteric or hydrothermal alteration. The charge contrast imaging results are especially important in demonstrating that deuteric perthites are far more abundant in alkali feldspars than would be concluded from investigations using conventional microscopy techniques. The unexpected presence of such a high volume of replacement products has significant implications for understanding the origins and geological histories of crustal rocks and the use of alkali feldspars in geo- and thermochronology. Whilst the precise properties of feldspars that generate contrast remain unclear, the similarity between charge contrast images and corresponding cathodoluminescence images of deuteric microperthites indicates that trace element chemistry and possibly also elastic strain within the crystal play a major role.

Flude, Stephanie; Lee, Martin R.; Sherlock, Sarah C.; Kelley, Simon P.

2012-06-01

120

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

PubMed Central

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

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

2013-01-01

121

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

NASA Astrophysics Data System (ADS)

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

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

2007-12-01

122

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

123

Cathodoluminescence (CL) of Lunar Minerals and Rocks  

NASA Astrophysics Data System (ADS)

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

Götze, J.

2009-08-01

124

Thermo-responsive poly(N-isopropylacrylamide) grafted onto microtextured poly(dimethylsiloxane) for aligned cell sheet engineering.  

PubMed

Poly(N-isopropylacrylamide) (PNIPAAm)-grafted poly(dimethylsiloxane) (PDMS) offers an inexpensive, biocompatible, oxygen permeable, and easily microtextured thermo-responsive substrate for producing cell sheets. This study introduces a method of grafting PNIPAAm onto microtextured PDMS that is suitable for generating aligned vascular smooth muscle cell (VSMC) sheets. We examined a wide range of processing parameters in order to identify the conditions that led to acceptable sheet growth and detachment behavior. Substrates grafted under these conditions produced confluent cell sheets that fully detached in less than 10 min after lowering the culture temperature from 37 °C to 20 °C. The grafted layer thickness was determined to be 496±8 nm by atomic force microscopy. Surface characterization by Fourier transform infrared spectroscopy showed a relative grafting yield of 0.488±0.10, defined as the ratio of the PNIPAAm 1647 cm(-1) to the PDMS 2962 cm(-1) absorbance peaks. The water contact angle of the substrates was shown to change from 89.6° to 101.0° at 20 °C and 37 °C, respectively. We also found that cell behavior on PNIPAAm-grafted PDMS was not directly related to surface wettability or relative grafting densities. PMID:22088757

Lin, Jenny B; Isenberg, Brett C; Shen, Yuankai; Schorsch, Katrin; Sazonova, Olga V; Wong, Joyce Y

2011-10-25

125

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

Southam, G.; Beveridge, T. J.

1992-01-01

126

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

SciTech Connect

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

Southam, G.; Beveridge, T.J. (Univ. of Guelph, Ontario (Canada))

1992-06-01

127

Secondary and Interactive Effects of Chronic Gaseous Pollutant Exposure of Producers, Consumers, and Decomposers Influence of Chronic Air Pollution on Mineral Cycling in Forests1  

Microsoft Academic Search

This paper reviews the literature concerning the impact of'chronic air pollution on mineral element cycling in forests. The concept involves the forest trees taking up essential and other elements from the soil and surrounding en- vironment eventually to return them to the soil upon mortality and decay. Chronic pollutants are considered in the context of this cycling as another form

Paul J. Zinke

128

Secondary School Science Teachers as the Key to a Sustainable Workforce in the Mining and Mineral Processing Industry: Changing Peoples' Attitudes  

Microsoft Academic Search

This paper reports on an innovative professional de velopment program for school science teachers run collaboratively between the Centre for Sustainable Resource Processing and Murdoch University. Ultimately the initiative aims at increasing the pool of school students with strong science and mathematics backgrounds while highlighting the challenging careers available in the mineral resource sector including the gold i ndustry. The

Dan Churach; Nicholas J. Welham

129

Mineral Animation  

NSDL National Science Digital Library

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

2010-01-01

130

Minerals Yearbook  

NSDL National Science Digital Library

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

131

Ore Minerals  

NSDL National Science Digital Library

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

Perkins, Dexter

132

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

SciTech Connect

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

Li Mingjun [Japan Aerospace Exploration Agency, Institute of Space and Astronautical Science, Tsukuba Space Center, ISS Science Project Office, 2-1-1 Sengen, Tsukuba, Ibaraki 305-8505 (Japan)]. E-mail: li.mingjun@jaxa.jp; Nagashio, Kosuke [Japan Aerospace Exploration Agency, Institute of Space and Astronautical Science, Sagamihara Campus, 3-1-1 Yoshinodai, Sagamihara, Kanagawa 229-8510 (Japan); Ishikawa, Takehiko [Japan Aerospace Exploration Agency, Institute of Space and Astronautical Science, Tsukuba Space Center, ISS Science Project Office, 2-1-1 Sengen, Tsukuba, Ibaraki 305-8505 (Japan); Yoda, Shinichi [Japan Aerospace Exploration Agency, Institute of Space and Astronautical Science, Tsukuba Space Center, ISS Science Project Office, 2-1-1 Sengen, Tsukuba, Ibaraki 305-8505 (Japan); Kuribayashi, Kazuhiko [Japan Aerospace Exploration Agency, Institute of Space and Astronautical Science, Sagamihara Campus, 3-1-1 Yoshinodai, Sagamihara, Kanagawa 229-8510 (Japan)

2005-02-01

133

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

134

Pyrophanite pseudomorphs after perovskite in Perkupa serpentinites (Hungary): a microtextural study and geological implications  

NASA Astrophysics Data System (ADS)

Pyrophanite in serpentinite at Perkupa (Hungary) is described in detail for the first time as a replacement product of perovskite. It occurs as a 20- to 30-?m-wide rim, mantling a remnant core composed of perovskite or its alteration products. The pyrophanite rim consists of an inner zone, representing a pseudomorph after perovskite, and an outer overgrowth zone. Raman mapping and electron backscatter diffraction data show that the pyrophanite rims typically represent single crystals rather than being composed of multiple domains in different crystallographic orientations. Perovskite occurs exclusively in the core of pyrophanite and was identified as the orthorhombic CaTiO3 phase, based on Raman spectra. Heterogeneous, polyphase mineral cores, consisting of calcite, anatase and/or brookite, kassite, and Mn-bearing kassite, in some cases in association with relict perovskite, are typical in the larger pyrophanite-rimmed grains. The crystallographically coherent pyrophanite rims could have formed through a process where the precursor perovskite crystal acted as a structural template for the newly forming phase, that is, by interface-coupled dissolution reprecipitation during serpentinization of the precursor rock. This alteration of perovskite to pyrophanite was not complete, resulting in the presence of perovskite fragments enclosed in pyrophanite. During the metamorphic evolution of the rock, some of the remnant perovskite cores further altered to TiO2 polymorphs (anatase and brookite) and calcite, via transitional alteration products.

Zajzon, N.; Váczi, T.; Fehér, B.; Takács, Á.; Szakáll, S.; Weiszburg, T. G.

2013-09-01

135

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.

136

Mineral Chart  

MedlinePLUS

... Tanning How Can I Improve My Self-Esteem? 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 ...

137

Mineral Properties  

NSDL National Science Digital Library

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

Mineralogy 4 Kids; America, Mineralogical S.

138

Minerals yearbook  

SciTech Connect

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

Not Available

1988-01-01

139

Comparisons of the four Miller Range nakhlites, MIL 03346, 090030, 090032 and 090136: Textural and compositional observations of primary and secondary mineral assemblages  

NASA Astrophysics Data System (ADS)

Petrological and geochemical analyses of Miller Range (MIL) 03346 indicate that this meteorite originated from the same augitic cumulate layer(s) as the nakhlite Martian meteorites, but underwent rapid cooling prior to complete crystallization. As with the other nakhlites, MIL 03346 contains a secondary alteration assemblage, in this case consisting of iddingsite-like alteration veins in olivine phenocrysts, Fe-oxide alteration veins associated with the mesostasis, and Ca- and K,Fe-sulfate veins. We compared the textural and mineralogical compositions of MIL 090030, 090032, and 090136 with MIL 03346, focusing on the composition and Raman spectra of the alteration assemblages. These observations indicate that the meteorites are paired, and that the preterrestrial olivine-bound alteration assemblages were produced by weakly acidic brine. Although these alteration assemblages resemble similar assemblages in Nakhla, the absence of siderite and halite in the Miller Range nakhlites indicates that the parental alteration brine was comparatively HCO3- depleted, and less concentrated, than that which altered Nakhla. This indicates that the Miller Range nakhlite alteration brine experienced a separate evolutionary pathway to that which altered Nakhla, and therefore represents a separate branch of the Lafayette-Nakhla evaporation sequence. Thin-sections cut from the internal portions of these meteorites (away from any fusion crust or terrestrially exposed edge), contain little Ca-sulfate (identified as gypsum), and no jarosite, whereas thin-sections with terrestrially exposed edges have much higher sulfate abundances. These observations suggest that at least the majority of sulfate within the Miller Range nakhlites is terrestrially derived.

Hallis, Lydia J.; Taylor, G. J.

2011-12-01

140

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

141

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

NASA Astrophysics Data System (ADS)

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

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

2011-12-01

142

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

143

Characterization of the state of a droplet at a micro-textured silicon wafer using a finite difference time-domain (FDTD) modeling method  

NASA Astrophysics Data System (ADS)

In this study, we introduce a finite difference time domain method to study the propagation and reflection of an acoustic wave on smooth and micro-textured silicon surfaces in interaction with droplets in different states. This will enable numerical investigations of interfaces composed of periodically distributed well-defined pillars. One type of transducer was modeled generating longitudinal wave. Three configurations were studied: the Cassie state, the Wenzel state and a composite state for which the droplet collapsed into the middle height of the pillars. After analysis of the displacement along y direction in the silicon wafer, we were able to show that a longitudinal wave is sensitive to the detection of the state of the droplet. The first experimental results made it possible to show a good agreement between modeling and experiments.

Saad, N.; Merheb, B.; Nassar, G.; Campistron, P.; Carlier, J.; Ajaka, M.; Nongaillard, B.

2012-12-01

144

Mineral Hunt  

NSDL National Science Digital Library

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

Science, Lawrence H.

2010-01-01

145

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.

146

Mystery Minerals  

NSDL National Science Digital Library

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

Morgan, Susan

147

Metal, mineral waste processing and secondary recovery  

Microsoft Academic Search

Approximately 40 million tons of precious metals chemical wastes are produced in the United States every year. An estimated five percent of these wastes are being reused\\/recycled to recover the precious and critical metals they contain. The rest of these chemical wastes are disposed of by the methods incineration, dumping at sea and dumping on land. In this paper, an

1987-01-01

148

Secondary sulfates found in an old adit from Rosia Montana, Romania  

Microsoft Academic Search

Recent investigation on several secondary minerals formed in old mining galleries in the Cârnic district (Ro?ia Montan?, Romania) enabled us to characterize ten minerals. Out of these ten identified minerals, the discovery of jokokuite is the first reported occurrence in the Carpathians. A second mineral identified as apjohnite represents a new occurrence in Romania. Along with these two rare minerals,

Bogdan P. Onac; Daniel Veres; Joe Kearns; Mirona Chirienco; Radu Breban

2012-01-01

149

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

150

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. ...

151

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, ...

152

Mineral Commodities  

NSDL National Science Digital Library

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

Perkins, Dexter

153

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

154

Thyroid disorders and bone mineral metabolism  

PubMed Central

Thyroid diseases have widespread systemic manifestations including their effect on bone metabolism. On one hand, the effects of thyrotoxicosis including subclinical disease have received wide attention from researchers over the last century as it an important cause of secondary osteoporosis. On the other hand, hypothyroidism has received lesser attention as its effect on bone mineral metabolism is minimal. Therefore, this review will primarily focus on thyrotoxicosis and its impact on bone mineral metabolism.

Dhanwal, Dinesh Kumar

2011-01-01

155

Secondary atomization  

Microsoft Academic Search

When a drop is subjected to a surrounding dispersed phase that is moving at an initial relative velocity, aerodynamic forces\\u000a will cause it to deform and fragment. This is referred to as secondary atomization. In this paper, the abundant literature\\u000a on secondary atomization experimental methods, breakup morphology, breakup times, fragment size and velocity distributions,\\u000a and modeling efforts is reviewed and

D. R. Guildenbecher; C. López-Rivera; P. E. Sojka

2009-01-01

156

A new model of Goss texture development during secondary recrystallization of electrical steel  

SciTech Connect

A new model of Goss texture development during the secondary recrystallization of electrical steel is proposed and tested in this paper. This model is based on the assumption that high-energy boundaries have high grain boundary diffusion coefficients. High diffusion coefficients facilitate precipitate coarsening along the high-energy boundaries, which in turn makes them mobile before other boundaries. Recent results obtained by the authors show that Goss grains are surrounded by the highest number of high-energy boundaries. The assumption that these boundaries are highly mobile allows the Goss grains to grow during secondary recrystallization. The new model is tested using a Monte-Carlo simulation of the grain growth in a 3-D polycrystalline computer specimen which describes both the microtexture and crystallographic texture of the electrical steel. The results of the simulation agree with experiment. Specifically, the pinning force and incubation time of secondary recrystallization as well as the orientation of the secondary recrystallized grains and the texture changes during grain growth are explained.

Hayakawa, Y.; Szpunar, J.A. [McGill Univ., Montreal, Quebec (Canada). Dept. of Mining and Metallurgical Engineering

1997-11-01

157

Properties of Minerals  

NSDL National Science Digital Library

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

Perkins, Dexter

158

Rocks and Minerals.  

ERIC Educational Resources Information Center

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

Naturescope, 1987

1987-01-01

159

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

160

Alaska's Mineral Industry, 1989.  

National Technical Information Service (NTIS)

Alaska's mineral industry experienced positive growth during 1989, especially in the hard-rock mining and exploration sectors, but suffered declines in mineral development expenditures, in sand-and-gravel, and in stone production. Overall value of mineral...

T. K. Bundtzen R. C. Swainbank J. R. Deagen J. L. Moore

1990-01-01

161

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.

162

State Mineral Summaries, 1993.  

National Technical Information Service (NTIS)

The State Mineral Summaries publication provides estimated data and summaries of mineral activities at the State level for 1992. Most of the estimates are based on nine months data. Individual State summaries are published separately as State Mineral Indu...

1993-01-01

163

Minerals yearbook vol. I: metals and minerals  

USGS Publications Warehouse

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

U.S. Geological Survey

164

Secondary Products  

Technology Transfer Automated Retrieval System (TEKTRAN)

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

165

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.

166

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.

History, National M.

2010-01-01

167

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

Mcmillan, Nancy

168

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

169

Direct observations of the atmospheric processing of Asian mineral dust  

Microsoft Academic Search

The accumulation of secondary acids and am- monium on individual mineral dust particles during ACE- Asia has been measured with an online single-particle mass spectrometer, the ATOFMS. Changes in the amounts of sul- phate, nitrate, and chloride mixed with dust particles cor- relate with air masses from different source regions. The uptake of secondary acids depended on the individual dust

R. C. Sullivan; S. A. Guazzotti; D. A. Sodeman; K. A. Prather

2007-01-01

170

Direct observations of the atmospheric processing of Asian mineral dust  

Microsoft Academic Search

The accumulation of secondary acids and ammonium on individual mineral dust particles during ACE-Asia has been measured with an online single-particle mass spectrometer, the ATOFMS. Changes in the amounts of sulphate, nitrate, and chloride mixed with dust particles correlate with air masses from different source regions. The uptake of secondary acids depended on the individual dust particle mineralogy; high amounts

R. C. Sullivan; S. A. Guazzotti; D. A. Sodeman; K. A. Prather

2007-01-01

171

Aspects of mineral transformation during weathering of volcanic material (the microscopic and submicroscopic level)  

Microsoft Academic Search

Mineral transformation at the earth surface is a complex process. In volcanic ejecta, such transformations tend to be fairly rapid. Many weathering studies on volcanic materials have been carried out at different scales of observations, mostly using bulk samples. However, to get a proper understanding of the mechanisms of weathering of primary minerals and formation secondary minerals it is necessary

A. G. Jongmans

1994-01-01

172

Mineral Spectroscopy Server  

NSDL National Science Digital Library

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

Rossman, George

173

Heavy Mineral Processing at Richards Bay Minerals  

Microsoft Academic Search

Located on the eastern shores of South Africa, 180 km north of Durban, Richards Bay Minerals (RBM) produces approximately 2.0 million metric tonnes of product annually making RBM a leading producer of titania slag, high purity pig iron, rutile and zircon. Heavy minerals are extracted from the nearby dunes by dredging and concentration on a floating gravity separation plant, followed

G. E. Williams; J. D. Steenkamp; Richards Bay Minerals; Richards Bay

174

Minerals: Calcium, Phosphorus, and Magnesium  

MedlinePLUS

... Minerals: Calcium, Phosphorus, and Magnesium Healthy Living Listen Minerals: Calcium, Phosphorus, and Magnesium Article Body Three minerals— calcium , phosphorus, and magnesium—account for 98% of ...

175

Herbs, Vitamins, and Minerals  

MedlinePLUS

Herbs, Vitamins, and Minerals Aloe The aloe plant, a member of the lily family, is a common household plant originally from Africa. Arnica ... Central and South America. Calcium Calcium is a mineral that is vital for a number of bodily ...

176

Mineral spirits poisoning  

MedlinePLUS

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

177

Minerals in Our Environment  

NSDL National Science Digital Library

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

Foundation, Wgbh E.

2005-12-17

178

Minerals Yearbook: Cuba, 2006.  

National Technical Information Service (NTIS)

Nickel was the most important mineral commodity to the Cuban economy followed by cobalt, which was produced as a byproduct of nickel mining. Other minerals produced in the country included cement, clays, crushed stone, feldspar, salt, and silica sand. Cub...

O. Bermudez-Lugo

2008-01-01

179

Dewatering of mineral slurries  

US Patent & Trademark Office Database

Mineral slurries are effectively dewatered by a process employing an aminofunctional silicone emulsion as a dewatering aid. The process provides for mixing the dewatering aid with the aqueous mineral slurry and thereafter separating the treated slurry into a mineral portion and an aqueous portion. The use of the aminofunctional silicones provide for reduced moisture content and/or increased production rate in a mineral slurry dewatering process.

Cooper; Ian V. (Georgetown, CA)

1985-06-25

180

Sedimentary and Related Minerals  

NSDL National Science Digital Library

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

Perkins, Dexter

181

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

NASA Astrophysics Data System (ADS)

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

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

2008-12-01

182

Seaweed minerals as nutraceuticals.  

PubMed

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

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

2011-01-01

183

Seaweed Minerals as Nutraceuticals  

Microsoft Academic Search

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

Ladislava Mišurcová; Ludmila Mach?; Jana Orsavová

2011-01-01

184

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.

185

INTRODUCTION TO MINERALS  

NSDL National Science Digital Library

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

Hughes, Mr.

2005-10-23

186

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.

Dyar, Darby

187

USGS mineral deposit models  

USGS Publications Warehouse

This CD-ROM publication is a compilation of 29 previously published mineral deposit model and related reports of the USGS. It in part reflects a history of mineral deposit model development within the USGS. Model types presented include descriptive, grade-tonnage, geoenvironmental, and geophysical. These models generally compile the geologic, geochemical, and geophysical characteristics of various types of metallic and nonmetallic mineral deposits. The models list attributes intended as guides for resource and geoenvironmental studies and for mineral exploration. They are presented using the lithologic-tectonic environmental mineral deposit classification scheme originally developed by Cox and Singer (1986).

edited by Stoeser, D. B.; Heran, William D.

2000-01-01

188

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.

Perkins, Dexter

189

Rocks and Minerals  

NSDL National Science Digital Library

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

Medina, Philip

2010-09-08

190

Rocks and Minerals  

NSDL National Science Digital Library

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

Medina, Philip

191

Scientists observe fungi-dissolving minerals  

NASA Astrophysics Data System (ADS)

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

Bhattacharya, Atreyee

2012-10-01

192

Mineral Deposit Densities for Estimating Mineral Resources  

Microsoft Academic Search

Estimates of numbers of mineral deposits are fundamental to assessing undiscovered mineral resources. Just as frequencies\\u000a of grades and tonnages of well-explored deposits can be used to represent the grades and tonnages of undiscovered deposits,\\u000a the density of deposits (deposits\\/area) in well-explored control areas can serve to represent the number of deposits. Empirical\\u000a evidence presented here indicates that the processes

Donald A. Singer

2008-01-01

193

Trapped Miner Communication  

Microsoft Academic Search

\\u000a Accident due to roof fall and collapse of side gallery is a regular occurrence in underground coal mines which causes death\\u000a of huge number of miners. To save valuable miners’ life, a suitable system is required for detecting the precise location\\u000a of a trapped miner and helping the rescue team or mine management in displacing the debris from the right

L. K. Bandyopadhyay; S. K. Chaulya; P. K. Mishra

194

Minerals in Our Environment  

NSDL National Science Digital Library

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

195

Minerals in Our Environment  

NSDL National Science Digital Library

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

2008-01-01

196

Mineral Information Office opens  

NASA Astrophysics Data System (ADS)

The U.S. Geological Survey and the U.S. Bureau of Mines opened their Mineral Information Office June 21 in Washington, D.C. The new office joins the Survey's recently renovated Earth Science Information Center in the Department of Interior building.The Mineral Information Office offers computer and video disc access to the geologic, geophysical, hydrologic, and cartographic information of both agencies, including the 127,000 items in the Survey's library and current statistics compiled by the Bureau of Mines on worldwide mineral production and use of more than 100 commodities. The staff has mineral experts to help customers.

197

Mineral Industry Surveys  

NSDL National Science Digital Library

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

198

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.

199

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.

200

Mineral Classification Exercise  

NSDL National Science Digital Library

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

Perkins, Dexter

201

Canadian Minerals Yearbook  

NSDL National Science Digital Library

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

2001-01-01

202

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

203

PSC 424: Rocks and Minerals  

NSDL National Science Digital Library

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

Graham, Ms.

2011-10-13

204

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.

205

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.

206

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

207

Rocks & Mineral Solitaire  

NSDL National Science Digital Library

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

Catania, Andrea J.; Education, San D.

208

Mineral Spirits Purification Process.  

National Technical Information Service (NTIS)

This patent application discloses a process for purifying mineral spirits which have been used to clean Otto Fuel II propelled torpedoes by heating the mineral spirits to decompose 1,2-propanediol dinitrate and remove hydrogen cyandide and other gaseous d...

D. R. Knudsen S. L. Collignon

1987-01-01

209

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

210

What is a Mineral?  

NSDL National Science Digital Library

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

2008-08-04

211

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.

212

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.

Galloway, John P.; Frank, Dave; Weathers, Judy

2010-10-08

213

VITAMINS AND MINERALS  

NSDL National Science Digital Library

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

Hughes, Mr.

2006-03-05

214

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

215

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

SciTech Connect

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

Not Available

1983-01-01

216

Biological Control on Mineral Transformation in Soils ?  

NASA Astrophysics Data System (ADS)

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

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

2001-12-01

217

Vitamins and Minerals during Pregnancy  

MedlinePLUS

... once in a 24 hour period. Vitamins and minerals during pregnancy Vitamins and minerals help give your body the nutrients it needs ... for some people to get enough vitamins and minerals in their foods. They may need to take ...

218

Mineral facilities of Europe  

USGS Publications Warehouse

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

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

2010-01-01

219

BAM R46: Mineral Oil  

Center for Food Safety and Applied Nutrition (CFSAN)

... Pesticide Analytical Manual (PAM). -. BAM R46: Mineral Oil. January 2001. Bacteriological Analytical Manual. R46 Mineral Oil. ... More results from www.fda.gov/food/foodscienceresearch/laboratorymethods

220

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

Code of Federal Regulations, 2012 CFR

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

2012-10-01

221

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

Code of Federal Regulations, 2011 CFR

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

2011-10-01

222

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.

223

The Density of Minerals  

NSDL National Science Digital Library

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

224

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

Microsoft Academic Search

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

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

1985-01-01

225

Primary and Secondary Sources  

NSDL National Science Digital Library

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

Bates, Albion M.

2010-01-23

226

Minerals yearbook, 1983. Volume 1. Metals and minerals  

SciTech Connect

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

Not Available

1984-01-01

227

Minerals yearbook, 1982. volume 1. metals and minerals  

SciTech Connect

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

Not Available

1984-01-01

228

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

229

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

230

Private Mineral Gallery Walk  

NSDL National Science Digital Library

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

Perkins, Dexter

231

Minerals Yearbook 1989: Boron.  

National Technical Information Service (NTIS)

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 ...

P. A. Lyday

1990-01-01

232

Minerals Yearbook 1990: Boron.  

National Technical Information Service (NTIS)

U.S. production and sales of boron minerals and chemicals increased 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 ...

P. A. Lyday

1991-01-01

233

Minerals Yearbook, 1993: Boron.  

National Technical Information Service (NTIS)

U.S. production and sales of boron minerals and chemicals increased during the year. Domestically, glass fiber insulation was the largest use for borates, followed by sales to borosilicate glass, textile-grade glass fibers, and agriculture. California was...

P. A. Lyday

1994-01-01

234

Calcium Carbonate Mineralization.  

National Technical Information Service (NTIS)

The objectives of the present study were to determine the mechanisms of ion transport across mineralizing epithelia of barnacles, in particular to quantify the effects of altered protein structure on crystal form and arrangement and the effects of the mol...

K. M. Wilbur A. LeFurgey

1995-01-01

235

Mineral Oil Compositions.  

National Technical Information Service (NTIS)

An isobutylene/dialkyl fumarate copolymer incorporated in mineral oils as a viscosity index improver and pour point depressant has improved hydrolysis stability in the presence of barium and other basic detergent additives. Low-temperature detergency is e...

J. E. Fields J. H. Johnson

1965-01-01

236

Characterization Lithium Mineralized Pegmatite.  

National Technical Information Service (NTIS)

Lithium economic importance has increased in the last years. In Brazil its reserves, generally pegmatites bodies, are found in Itinga-Aracuai-MG. This study of characterization belongs to a global plan of lithium mineralized bodies research of 'Arqueana d...

E. F. S. Pereira O. Luz Ferreira R. Z. L. Cancado J. Mauricio Neto

1986-01-01

237

Minerals Yearbook, 1989. Volume i. Metals and Minerals  

SciTech Connect

The edition of the Minerals Yearbook discusses the performance of the worldwide mineral industry during 1989 and provides background information to assist in interpreting that performance. Volume I, Metals and Minerals, contains chapters on virtually all metallic and industrial mineral commodities important to the U.S. economy. A chapter on advanced materials also has been added to the Minerals Yearbook series beginning with the 1989 volume. In addition, a chapter on survey methods used in data collection with a statistical summary of nonfuel minerals and a chapter on trends in mining and quarrying in the metals and industrial mineral industries are included.

Not Available

1989-01-01

238

Vitamins, Minerals, and Mood  

Microsoft Academic Search

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 compounds (choline). Recent investigations with multi-ingredient formulas are especially

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

2007-01-01

239

Solid Mineral Resources  

Microsoft Academic Search

\\u000a Nigeria as a nation is blessed with abundant solid mineral resources distributed fairly in all the states of the federation\\u000a (Fig. 10.1; Table 10.1). According to reports by the Geological Survey of Nigeria Agency, Nigeria has some 34 known major\\u000a mineral deposits distributed in locations across the country and offers considerable attraction for investors. Exploration\\u000a in Nigeria for several solid

Nuhu Obaje

240

[Synthetic mineral fibers].  

PubMed

The group of man-made mineral fibres includes slagwool, glasswool, rockwool, glass filaments and microfibres, as well as refractory ceramic fibres. The toxicity of mineral fibres is determined by several factors such as the diameter (< or = 3-3.5 microns) and the length of the fibres (< 100 microns), their biopersistence, which is much shorter for man-made mineral fibres than for asbestos fibres, their physicochemical structure and surface properties, and the exposure level. The chemical composition of the various types of man-made mineral fibres depends directly on the raw material used to manufacture them. While naturally occurring fibres are crystalline in structure, most man-made mineral fibres are amorphous silicates combined with various metal oxides and additives. Observations using intracavitary administration have provided evidence that some types of man-made mineral fibres are bioactive in cellular and animal experiments and may induce lung tumours and mesothelioma. It is difficult to extrapolate these results to humans since they bypass inhalation, deposition, clearance and translocation mechanisms. Inhalation studies show more realistic results but differences are observed between animal species regarding their sensibility to tumours. There is no firm evidence that exposure to various wools is associated with lung fibrosis, pleural lesions or nonspecific respiratory disease in humans. A possible exception may be mentioned for refractory ceramic fibres. A slightly elevated standard mortality ratio for lung cancer has been documented in large cohorts of workers (USA, Europe and Canada) exposed to man-made mineral fibres, especially in the early technological phase. It is not possible to determine from these data whether the risk of lung cancer is due to the man-made mineral fibres themselves, in particular due to the lack of data on smoking habits. No increased risk of mesothelioma has been demonstrated in these cohorts. Epidemiological data are insufficient at this time concerning neoplastic diseases in refractory ceramic fibres. PMID:10231901

Boillat, M A

1999-03-27

241

Fluorescent minerals, a review  

USGS Publications Warehouse

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

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

1996-01-01

242

[Recovered water mineralization technique].  

PubMed

The possibility to mineralize water by metering out concentrated salt solutions in the amounts necessary to bring it to within the potable water standards with intermediate exchange of chlorine ions for bicarbonate-ions has been demonstrated. The proposed technique ensures physiological quality and stability of recovered water mineralized with solutions of inorganic salts. Stability of concentrated salt solutions kept in metering syringes and potable water was evaluated. Organoleptic tests of resultant potable water were conducted. PMID:11840873

Skliar, E F; Amiragov, M S; Berezkin, S V; Kurochkin, M G; Skuratov, V M

2001-01-01

243

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.

244

Minerals Yearbook 1989: Lithium  

SciTech Connect

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

Ober, J.A.

1989-01-01

245

Minerals Yearbook, 1988. Boron  

SciTech Connect

U.S. production and sales of boron minerals and chemicals decreased during the year. Glass-fiber insulation was the largest use for borates, followed by sales to distributors, textile-grade glass fibers, and borosilicate glasses. California was the only domestic source of boron minerals. The report discusses the following: domestic data coverage; legislation and government programs; domestic production; comsumption and uses; prices; foreign trade; world capacity; world review--Argentina, Chile, France, Italy, Turkey, United Kingdom; Technology.

Lyday, P.A.

1988-01-01

246

Iron oxide modified minerals  

Microsoft Academic Search

Composites of iron oxide nanoparticles immobilized on the surface of various clay mineral matrices (muscovite, montmorillonite\\u000a and vermiculite) have been prepared by the alkaline oxidative hydrolysis of iron sulphate in the presence of mineral matrices.\\u000a The composites have been studied by Mössbauer spectroscopy, XRD, TEM and SQUID. Correspondence between the hyperfine parameters\\u000a and the iron oxide particle size and magnetic

M. Mashlan; H. Bartonkova; D. Jancik; J. Tucek; P. Martinec

247

Iron oxide modified minerals  

Microsoft Academic Search

Composites of iron oxide nanoparticles immobilized on the surface of various clay mineral matrices (muscovite, montmorillonite\\u000a and vermiculite) have been prepared by the alkaline oxidative hydrolysis of iron sulphate in the presence of mineral matrices.\\u000a The composites have been studied by Mössbauer spectroscopy, XRD, TEM and SQUID. Correspondence between the hyperfine parameters\\u000a and the iron oxide particle size and magnetic

M. Mashlan; H. Bartonkova; D. Jancik; J. Tucek; P. Martinec

2009-01-01

248

Chemical processing does not always impair heterogeneous ice nucleation of mineral dust particles  

Microsoft Academic Search

Mineral dust particles are the most abundant heterogeneous ice nuclei in the atmosphere. They also frequently become mixed with secondary material during atmospheric transport. The effect that such atmospheric processing has on the ice nucleation properties of dust particles remains under investigation. We have studied changes in the ice nucleation ability of various mineral dust sources after exposure to nitric

R. C. Sullivan; P. J. Demott; A. J. Prenni; L. Minambres; S. M. Kreidenweis; O. Moehler

2010-01-01

249

Impact of Process and Energy Efficiency in Mineral Processing on Abatement of Carbon Emissions  

Microsoft Academic Search

Mineral processing industry is facing tough challenges regarding abatement of carbon emissions, the use of water and energy. Mine activities requires bulk material handling, mineral ore transportation with haul trucks and machinery with important use of diesel fuel that produce direct emissions while plant operations have an intensive use of electrical energy with important indirect emissions. Based on available secondary

Jorge Pontt; Juan Yianatos; Luis Bergh; Waldo Valderrama; Fernando Rojas; Manuel Olivares; Hernán Robles; Manuel López

2010-01-01

250

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

251

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

252

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

253

Economic MInerals in Geothermal Waters  

Microsoft Academic Search

Geothermal resources may carry minerals in water, sinters and precipitates, and in steam. The utilization of these minerals is hampered by a lack of interest on the part of geochemists, by institutional obstacles, and by incomplete data on the quantity and quality of the minerals. The potential of obtaining minerals from geothermal resources is discussed. Nearly all geothermal hot water

Barnea

1979-01-01

254

Direct observations of the atmospheric processing of Asian mineral dust  

Microsoft Academic Search

The accumulation of secondary acid products and ammonium on individual mineral dust particles during ACE-Asia has been measured in real-time using ATOFMS. Changes in the amounts of sulphate, nitrate, and chloride mixed with dust particles corresponded to different air mass source regions. During volcanically influenced periods, dust mixed with sulphate dominated. This rapidly switched to dust predominantly mixed with chloride

R. C. Sullivan; S. A. Guazzotti; D. A. Sodeman; K. A. Prather

2006-01-01

255

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...

256

Occurrence of secondary magnetite within biodegraded oil  

SciTech Connect

Samples of solid bitumen from the Thornton Quarry (Illinois) and the Cynthia Quarry (Mississippi) were found to be strongly magnetic and to have rock magnetic properties suggesting that the magnetizable grains present are magnetite. Studies of magnetic isolates revealed that magnetite is present primarily as spherical crystal aggregates that appear identical to magnetite spherules isolated from remagnetized Paleozoic carbonate units from other localities. Organic geochemical analyses of the solid bitumen suggest an origin by microbial attack on what once was liquid crude oil. The occurrence of secondary magnetite as inclusions within solid bitumen suggests a relationship between crude oil biodegradation and development of that mineral in their samples. The authors infer that secondary magnetite in other geologic environments may be related to the presence of hydrocarbons. The discovery of a natural association of secondary magnetite and hydrocarbons has important implications for paleomagnetism and for petroleum exploration.

McCabe, C.; Sassen, R.; Saffer, B.

1987-01-01

257

Mineral hydrolysis kinetics  

SciTech Connect

Dissolution rate laws for silicate mineral weathering can be related to kinetics of ligand-exchange reactions. This relation is being tested with an experimental/analytical/theoretical program for measuring the dissolution kinetics of orthosilicate minerals for use in ionic modeling and molecular dynamics computer simulations of solid, aqueous solution, and solid/liquid interface. To date, dissolution rate have been measured for a suite of endmember and mixed-cation orthosilicate minerals (both olivine and willemite structures) as well as a few inosilicate minerals (pyroxenes). Dissolution rates appear to correlate well with solvent exchange rates around the hydrated divalent cations. Siloxane (Si-O-Si) bonds are relatively unreactive at low pH`s close to zero point of neutral charge for quartz. The correlation suggests that silicic acid would be released from the reacting surfaces after protonation and hydration of bonds between divalent metals and structural oxygens; congruent dissolution is confirmed by Rutherford backscattered analysis of the near-surface of an acid-reacted forsterite. In the ionic modeling, except for liebenbergite, there is a general trend of increasing lattice energy with decreasing dissolution rate for endmember and mixed-cation orthosilicate minerals at pH 2. 3 figs, 4 refs.

Westrich, H.R.; Cygan, R.T.; Arnold, G.W. [Sandia National Labs., Albuquerque, NM (United States); Casey, W.H. [California Univ., Davis, CA (United States). Dept. of Land, Air, and Water Resources

1993-07-01

258

Minerals and foreign policy  

SciTech Connect

There is no such thing as a purely domestic or foreign minerals issue. Domestic policies, such as the setting aside of public lands as wilderness regions or enforcement of stringent clean air standards on smelters, may link directly to our world trade and supply position and affect foreign-policy interests. Conversely, economic and political events in far corners of the world may affect whether an American plant will be able to obtain a certain critical industrial or strategic commodity. The State Department attaches importance to a strong domestic-mining sector which can contribute to our defense, economic, and foreign-policy objectives. The Department will continue to give a high priority of nonfuel mineral-supply issues in the conduct of foreign affairs. The inquiry into problems of national minerals policy, which Congressman Santini and others in Congress currently are making in connection with the Presidential non-fuel minerals policy review, has been very helpful. An active and sustained interest by the relevant Congressional committees, in consultation with the Administration, can add significantly to our understanding of minerals issues and can facilitate the implementation of more effective policies to deal with them.

Calingaert, M.

1980-01-01

259

Fluoride and mineralized tissues.  

PubMed

This review focuses on the interaction of fluoride with the material properties of bone and teeth, which is of clinical, scientific, and public health interest. These tissues are composed primarily of collagen (protein) and hydroxyapatite (mineral), and their mechanical function depends on the properties of the constituents, their proportions, the interface, and the three-dimensional structure. Changing any of these may have clinical consequences. Fluoride interacts with mineralized tissues in a number of ways. At low doses, the fluoride may be passively incorporated into the mineral, stabilizing it against dissolution; this is one of the mechanisms by which municipally fluoridated water reduces the incidence of dental caries. At higher doses, such as those used for treatment of osteoporosis, the fluoride may alter the amount and structure of tissue present, including altering the interface between the collagen and mineral. At very high doses, skeletal and dental fluorosis occurs, characterized by debilitating changes in the skeleton and by marked mottling and discoloration of teeth, which may be accompanied by increased wear of the enamel. These effects have been observed in communities where the local drinking water has naturally high fluoride levels. Understanding the influence of fluoride on mineralized tissues is, therefore, of considerable significance. PMID:19740071

Chachra, Debbie; Vieira, Anya P G F; Grynpas, Marc D

2008-01-01

260

Scaling of Secondary Craters.  

National Technical Information Service (NTIS)

Secondary craters are common features around fresh planetary-scale primary impact craters throughout most of the Solar System. They derive from the ejection phase of crater formation, thus secondary scaling relations provide constraints on parameters affe...

S. K. Croft

1991-01-01

261

Mercury from mineral deposits and potential environmental impact  

USGS Publications Warehouse

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

Rytuba, J. J.

2003-01-01

262

The JMU Mineral Museum - Observing Physical Properties of Minerals  

NSDL National Science Digital Library

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

Kearns, Cynthia A.

263

Maneuverable full face miner  

SciTech Connect

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

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

1980-12-16

264

Soil C and N dynamics in primary and secondary seasonally dry tropical forests in Mexico  

Microsoft Academic Search

The nature and size of soil carbon (C) and nitrogen (N) pools and turnover were compared in secondary and primary forests in a seasonally dry tropical region of Mexico. Total soil C and N, microbial biomass C and N, mineral (ammonium and nitrate) N pools and potential mineralization and nitrification were measured in samples collected during the dry and rainy

Vinisa Saynes; Claudia Hidalgo; Jorge D. Etchevers; Julio E. Campo

2005-01-01

265

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

266

Advancements for continuous miners  

SciTech Connect

Design changes and new technology make the modern continuous miner more user friendly. Two of the major manufacturers, Joy Mining Machinery and DBT, both based near Pittsburgh, PA, USA, have recently acquired other OEMs to offer a greater product line. Joy's biggest development in terms of improving cutting time is the FACEBOSS Control System which has an operator assistance element and Joy Surface Reporting Software (JSRP). Joy's WetHead continuous miners have excellent performance. DBT is researching ways to make the machines more reliable with new drive systems. It has also been experimenting with water sprays to improve dust suppression. 4 photos.

Fiscor, S.

2007-06-15

267

Vitamin/mineral composition  

US Patent & Trademark Office Database

A composition comprising Shilajit or an extract thereof in a vitamin and/or mineral preparation. Shilajit is a compact mass of vegetable organic matter, composed of a gummy matrix interspersed with vegetable fibres and minerals. Substances which have been identified in Shilajit include moisture, gums, albuminoids, calcium, potassium, nitrogen, silica, resin, vegetable matter, magnesium, sulphur, iron, chloride, phosphorous, iodine, glycosides, tannic acid, benzoic acid and a number of vitamins and enzymes. The invention further relates to a method to restore energetic balance or intensity, or to support or enhance a bioenergetic field in a mammal comprising administering to a mammal an effective amount of Shilajit or an extract thereof.

Rowland; David (Nobel, CA)

1995-04-11

268

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

269

The effect of risedronate on bone mineralization as measured by micro-computed tomography with synchrotron radiation: Correlation to histomorphometric indices of turnover  

Microsoft Academic Search

The primary goal of our study was to determine changes in bone mineralization in postmenopausal osteoporotic women treated for 3 years with risedronate or placebo. A secondary goal was to determine the relationship between mineralization and indices of bone turnover measured on the same biopsies. The degree of mineralization was measured by micro-computed tomography using Synchrotron radiation (Synchrotron ?CT) in

Babul Borah; Erik L. Ritman; Thomas E. Dufresne; Steven M. Jorgensen; Sheng Liu; Jarek Sacha; Roger J. Phipps; Russell T. Turner

2005-01-01

270

Ice nucleation properties of the most abundant mineral dust phases  

NASA Astrophysics Data System (ADS)

The ice nucleation properties of the nine most abundant minerals occurring in desert aerosols (quartz, albite, microcline, kaolinite, montmorillonite, illite, calcite, gypsum, and hematite) were investigated by environmental scanning electron microscopy (ESEM). In this instrument, the pure minerals are exposed to water vapor at variable pressures and temperatures. The crystallization of ice on the mineral particles is observed by secondary electron imaging, and the supersaturation for an activated particle fraction of 1-3% is determined as function of temperature. In all experiments, condensation of water prior to ice formation was not observed within detectable limits, even at water supersaturation. The highest temperatures for 1-3% activation vary between -10°C and -16°C for the nine minerals investigated, and the corresponding onset relative humidities relative to ice RHi between 107 and 117%. Supersaturation temperature curves for initial ice formation (1-3% activation) in the temperature range typical for mixed-phase clouds were measured for all nine minerals. The temperature dependence of the onset relative humidity is strongly dependent on mineralogy. Kaolinite, montmorillonite, and hematite show a strong increase in RHi with decreasing temperature, whereas RHi is almost constant for illite, albite, quartz, and calcite. The highly variable ice nucleation properties of the various mineral dust components should be considered for parameterization schemes. Illite and kaolinite are the most important minerals to consider, as they have high ice nucleation efficiency and are common components of desert aerosols.

Zimmermann, Frank; Weinbruch, Stephan; Schütz, Lothar; Hofmann, Heiko; Ebert, Martin; Kandler, Konrad; Worringen, Annette

2008-12-01

271

The Physical Characteristics of Minerals  

NSDL National Science Digital Library

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

1998-01-01

272

Minerals yearbook 1977. Volume I. Metals and minerals  

SciTech Connect

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

Not Available

1980-01-01

273

Secondary power systems  

SciTech Connect

In aeronautical engineering secondary power systems have long played second fiddle to the airframe, the engine, and indeed, the avionics. This collection of papers is thus timely, and its publication by the Institution of Mechanical Engineers appropriate, as secondary power systems in modern aircraft present challenging mechanical engineering problems. In military aircraft demands for electrical and hydraulic power and high pressure air have grown over the past two decades. To these basic needs are added requirements for emergency power, ground power, and independent engine starting. Additionally increased reliability and maintainability is demanded from all secondary power systems. Complete contents: What is a secondary power system. Modern technology secondary power systems for next generation military aircraft; Integrated power units; Secondary power system gearbox; Starting the system - air turbine starters; Auxiliary and emergency power system; Secondary hydraulic power generation; Advanced technology electrical power generation equipment.

Not Available

1985-01-01

274

Minerals yearbook, 1985. Volume 1. Metals and minerals  

SciTech Connect

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

Not Available

1987-01-01

275

Minerals Yearbook, 1988. Volume 1. Metals and minerals  

SciTech Connect

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

Not Available

1990-01-01

276

Minerals yearbook, 1984. Volume 1. Metals and minerals  

SciTech Connect

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

Not Available

1985-01-01

277

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

Microsoft Academic Search

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

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

1984-01-01

278

Minerals Yearbook, 1992: Boron.  

National Technical Information Service (NTIS)

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 be sales to textile-grade glass fibers, and soaps and detergents. California was the only d...

P. A. Lyday

1993-01-01

279

Minerals Yearbook, 1991: Boron.  

National Technical Information Service (NTIS)

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 textile-grade glass fibers, sales to distributors, and borosilicate glasses. Ca...

P. A. Lyday

1992-01-01

280

Minerals Yearbook, 1990: Indiana.  

National Technical Information Service (NTIS)

The report is on the Mineral Industry of Indiana. The State's position as the Nation's leading steel producer was solidified by several events, including completion of the $525 million I/N Tek cold rolling mill at New Carlisle in March. Other noteworthy d...

W. J. West

1992-01-01

281

Mixtures and mineral reactions  

SciTech Connect

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

Saxena, S.; Ganguly, J.

1987-01-01

282

Mineral Resources Research Center.  

National Technical Information Service (NTIS)

In the United States nearly one billion tons of material per year are subjected to comminution processes in the mineral and cement industries at an approximate power consumption of 25 billion kilowatt-hours. Clearly, even small improvements in the efficie...

A. J. Lynch R. L. Wiegel

1972-01-01

283

Introduction to Mineral Equilibria  

NSDL National Science Digital Library

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

Perkins, Dexter

284

Ocean mineral revenue sharing  

Microsoft Academic Search

This article considers the importance of ocean mineral revenue sharing, from both the oil and gas of the continental margin and the manganese nodules of the deep seabed, at the United Nations Law of the Sea Conference. First the paper examines margin revenue sharing as proposed in Article 82, Informal Composite Negotiating Text. It estimates the amount of oil and

Vincent J. Nigrelli

1978-01-01

285

Minerals Yearbook, 1991: Mississippi.  

National Technical Information Service (NTIS)

The report has been prepared under a Memorandum of Understanding between the U.S. Bureau of Mines, U.S. Department of the Interior, and the Office of Geology, Mississippi Department of Environmental Quality, for collecting information on all nonfuel miner...

D. H. White S. C. Knox M. B. E. Bograd

1993-01-01

286

Fossils and Minerals  

NSDL National Science Digital Library

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

Research, Inc. B.

287

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…

Allison, Diane

2005-01-01

288

Spectral reflectance of carbonate minerals in the visible and near infrared (0.35-2.55 um): Anhydrous carbonate minerals  

NASA Astrophysics Data System (ADS)

Reflectance spectroscopy in the visible and near infrared (0.35-2.55 um) offers a rapid, inexpensive, nondestructive technique for determining the mineralogy and gaining information on the minor element chemistry of carbonate minerals and rocks. Spectra of all commonly occurring anhydrous end-member carbonate minerals contain seven strong absorption bands at wavelengths >1.6 um due to vibrations of the carbonate radical. Positions, widths, and spacing between carbonate bands are diagnostic of mineralogy. Differences in positions of carbonate bands between spectra of different minerals are primarily due to differences in mass of the major cation, with cation electronegativity playing a secondary role. Spectra of calcite group minerals may contain absorption features due to transition metal cations such as Fe and Mn, which can also aid in mineral identification. Spectra confirm the occurrence of both cations in the divalent state. Fe2+ produces a broad feature near 1.1 um whose position and degree of doubling are related to the size and degree of distortion of the octahedral site, as predicted by crystal field theory. Mn2+ and Fe2+ produce very strong absorption bands in the minerals for which they are the major cation (rhodochrosite and siderite, respectively), making it easy to distinguish these from other carbonate minerals, even when presence of water bands may make it difficult to determine accurately carbonate band positions.

Gaffey, Susan J.

1987-02-01

289

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.

290

BET Measurements: Outgassing of Minerals  

Microsoft Academic Search

Outgassing minerals at elevated temperatures prior to BET measurements can lead to phase changes, especially in the case of amorphous and poorly crystalline materials. In order to evaluate the applicability of the BET method when low outgassing temperatures are required, selected aquifer minerals were outgassed at different temperatures and for different times. The studied minerals are 2-line ferrihydrite, goethite, lepidocrocite,

Liselotte Clausen; Ida Fabricius

2000-01-01

291

Efflorescent minerals associated with coal  

Microsoft Academic Search

A study of efforescent coal minerals was made which included the identification, description, and mode of occurrence of coal associated mineral efflorescenses found in the bituminous coal mining area surrounding Morgantown, West Virginia. Samples of efflorescences were collected from road cuts, strip mines, entrances to underground mines, and mine discharge pumps and were analyzed for mineral and chemical composition by

Nuhfer

1967-01-01

292

Common Rock-Forming Minerals  

NSDL National Science Digital Library

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

Weiland, Tom

293

Trace Minerals in Cottage Cheese  

Microsoft Academic Search

The trace minerals, iron, zinc, copper, and manganese were determined in cot- tage cheese curd by flameless atomic absorption. Larger curd size, added calci- um chloride, and fewer washes increased the iron and zinc content in the curd. We recently reported on the major mineral constituents of cottage cheese and the manu- facturing variables that affect the retention of minerals

N. P. Wong; D. E. LaCroix; J. H. Vestal

1977-01-01

294

Mineral Abundance Near Aristarchus Crater  

Microsoft Academic Search

Mineral Abundance Near Aristarchus Crater Alison Bradford and Alex Storrs Towson University We analyze Hubble Space Telescope (HST) images to determine the abundance of minerals near Aristarchus crater. Following the calibration of Robinson et al. (2007) we present ratio maps of images obtained in August of 2005 showing the abundance of TiO2 and other minerals in this interesting area in

Alison Bradford; A. Storrs

2007-01-01

295

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

296

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.

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

2008-01-01

297

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

2008-04-23

298

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

299

Minerals yearbook, 1991. 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 1991 and provides background information to assist in interpreting that performance. Volume 1, Metals and Mineral, contains chapters on virtually all metallic and industrial mineral commodities important to the U.S. economy. Chapters on advanced materials and nonrenewable organic materials also were added to the Minerals Yearbook series beginning with the 1989 and 1990 volumes, respectively. A new chapter on nonferrous metals recycling has been initiated in this 1991 volume. In addition, a chapter on survey methods used in data collection with a statistical summary of nonfuel minerals and a chapter on trends in mining and quarrying in the metals and industrial mineral industries are included.

NONE

1991-12-31

300

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

SciTech Connect

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

Not Available

1992-01-01

301

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

302

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

303

Vitamins and Minerals in Kidney Disease  

MedlinePLUS

... Disease A to Z Health Guide Vitamins and Minerals in Kidney Disease Vitamins and minerals are important ... the form of supplements. What are vitamins and minerals? Vitamins and minerals are substances needed by your ...

304

Simmonsite, Na2LiAlF6, a new mineral from the Zapot amazonite-topaz- zinnwaldite pegmatite, Hawthorne, Nevada, U.S.A  

Microsoft Academic Search

Simmonsite, Na2LiA1F6, a new mineral of pegmatitic-hydrothermal origin, occurs in a late-stage brec- cia pipe structure that cuts the Zapot amazonite-topaz-zinnwaldite pegmatite located in the Gillis Range, Mineral Co., Nevada, U.S.A. The mineral is intimately intergrown with cryolite, cryolithionite and trace elpasolite. A secondary assemblage of other alumino-fluoride minerals and a second generation of cryolithionite has formed from the primary

EUGENE E. FOORD; J OSEPH T. O'C; JOHN M. HUGHES; STEPHEN J. SUTLEY; ALEXANDER U. FALSTER; ARTHUR E. SOREGAROLI; FREDERICK E. LICHTE; DANIEL E. KILE

305

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

306

Mineral accretion in seawater  

NASA Astrophysics Data System (ADS)

By performing electrolysis in seawater a concrete-like accretion of precipitating aragonite (one crystalline form of CaCO3) and brucite (Mg(OH) 2) slowly develops onto the cathode. The accretion forms by high pH conditions caused by the reduction reactions occurring at the cathode. A solid casing of accretions over a preformed cathodic mesh has the potential for many engineering applications such as artificial reefs, sub-surface breakwaters and pipe construction. To investigate using mineral accretion as an alternative means of construction, experiments in the open coast, laboratory and ocean harbor have resulted in tables that can projected into a feasibility study. Inevitable current density variations over the cathodic framework and sensitivity to seawater hydrodynamics make accretion thickness difficult to predict and control in practice. Ideal conditions for growing a large-scale mineral accretion structure are still, clean ocean waters where low DCV power can be delivered on the order of years.

Bozak, Ronald Richard

2000-10-01

307

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

308

Minerals and mine drainage  

SciTech Connect

This paper is part of the Annual Literature Review issue of Water Environment Research. The review attempts to provide a concise summary of important water-related environmental science and engineering literature of the past year, of which 40 separate topics are discussed. On the topic of minerals and mine drainage, the present paper deals with the following aspects: environmental impacts; environmental regulations; characterization; prevention; treatment; and reclamation. 34 refs.

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

1994-06-01

309

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

310

Microbially mediated mineral carbonation  

Microsoft Academic Search

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

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

2010-01-01

311

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.

312

FEDERAL MINERAL LAND INFORMATION SYSTEM.  

USGS Publications Warehouse

The ability of geographic information systems to combine point, line, and areal data has been widely documented, although the establishment of a particular data base presents its own unique problems. The U. S. Geological Survey is developing a geographic information system consisting of information on Federal surface ownership, Federal subsurface mineral rights, location of actual mineral occurrences and (or) known potential, and formal restrictions to mineral development. By utilizing information already compiled or soon to be collected by other agencies, the Federal Mineral Land Information System should be able to provide answers relating to mineral availability on public lands.

Kleckner, Richard, L.

1984-01-01

313

Humanizing the Secondary School.  

ERIC Educational Resources Information Center

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

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

314

Research in Secondary Reading.  

ERIC Educational Resources Information Center

Summers' annotated bibliographies of secondary reading (1963, 1964), "Review of Educational Research,""Journal of Reading," ERIC/CRIER, and "Research in Education" are listed as resources for all phases of reading. A shifting of trends in the nature and scope of research topics in secondary reading is noted, with diagnosis and treatment,…

Kling, Martin

315

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

Microsoft Academic Search

Major-element analyses (by electron microprobe) and copper contents (by ion-probe) are reported for primary biotite, amphibole,\\u000a magnetite, pyroxene, ilmenite, sphene and secondary biotite from intrusive rocks from mineralizing and barren stocks. The\\u000a districts studied include Christmas, Globe-Miami, Sierrita and Tombstone, in Arizona; Bingham and Alta, Utah; Ely, Nevada;\\u000a and Brenda, British Columbia.\\u000a \\u000a Amphiboles from barren rocks are relatively iron-rich and

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

1985-01-01

316

A Re–Os study of sulfide minerals from the Bagdad porphyry Cu–Mo deposit, northern Arizona, USA  

Microsoft Academic Search

Rhenium and osmium isotopes in sulfide minerals from the Bagdad porphyry Cu–Mo deposit have been used to determine timing of mineralization and the source of osmium and, by inference, ore metals. Molybdenite, chalcopyrite and pyrite were analyzed mainly from the quartz monzonite and porphyritic quartz monzonite units, which are characterized by moderate to strong potassic alteration (secondary biotite and K-feldspar).

Fernando Barra; Joaquin Ruiz; Ryan Mathur; Spencer Titley

2002-01-01

317

Investigation of lichens using molecular techniques and associated mineral accumulations on a basaltic flow in a Mediterranean environment  

Microsoft Academic Search

The role of lichens in the breakdown of rocks in various environments is well documented. We investigated the formation of secondary minerals under 13 different fungal species growing on a basaltic flow in Sanliurfa (Turkey) to understand the influence of lichen species on the transformation of minerals in a Mediterranean environment. We used molecular technique (rDNA sequence) to identify 13

Joselito M. Arocena; Tariq Siddique; Ronald W. Thring; Selim Kapur

2007-01-01

318

Secondary and tertiary hyperparathyroidism.  

PubMed

We reviewed the etiology and management of secondary and tertiary hyperparathyroidism. Secondary hyperparathyroidism is characterized by an increase in parathyroid hormone (PTH) that is appropriate and in response to a stimulus, most commonly low serum calcium. In secondary hyperparathyroidism, the serum calcium is normal and the PTH level is elevated. Tertiary hyperparathyroidism is characterized by excessive secretion of PTH after longstanding secondary hyperparathyroidism, in which hypercalcemia has ensued. Tertiary hyperparathyroidism typically occurs in men and women with chronic kidney disease usually after kidney transplant. The etiology and treatment of secondary hyperparathyroidism is relatively straightforward whereas data on the management of tertiary hyperparathyroidism is limited to a few small trials with short follow-up. PMID:23267748

Jamal, Sophie A; Miller, Paul D

2012-12-23

319

Mineral industries of Australia, Canada, and Oceania (including a discussion of Antarctica's mineral resources). Mineral perspective  

SciTech Connect

The Bureau of Mines report gives the mineral industry highlights of two of the world's major mineral producing countries, Australia and Canada, and seven Pacific island nations or territories--Fiji, New Caledonia, New Zealand, Papua New Guinea, Republic of Nauru, Solomon Islands, and Vanuatu. The mineral resources of Antarctica are also discussed. Because of the size of the Australian and Canadian mineral industries, summary reviews are presented for each of the States, Provinces, or Territories. The most current information available from all nations is given on major minerals or mineral-commodity production, share of world production, and reserves. Reported also are significant mining companies, locations and capacities of their main facilities, and their share of domestic production. Other information is provided on mineral-related trade with the United States, government mineral policy, energy production-consumption and trade, the mining industry labor force, and prospects for the mineral industry. Maps show the locations of selected mineral deposits, oilfields and gasfields, mines, and processing facilities including iron and steel plants, nonferrous smelters and refineries, and cement plants, as well as infrastructure pertinent to the mineral industry.

Kimbell, C.L.; Lyday, T.Q.; Newman, H.H.

1985-12-01

320

[Clinical study of concerning factors of decreased bone mineral content in hemodialysis patients].  

PubMed

We investigated bone mineral content and factors related to decreased bone mineral content in maintenance hemodialysis patients. Bone mineral contents, epsilon GS/D, radius-bone mineral content (R-BMC) and L3-bone mineral density (L3-BMD), were measured with a micro densitometer, a bone mineral analyzer and a dual energy quantative CT scanner, and relative bone mineral contents (% epsilon GS/D, %R-BMC and %L3-BMD) were calculated respectively. The desferrioaxmine infusion test was carried out for diagnosis of aluminium associated bone disease, and an elevated level of aluminium (delta aluminium) was observed. There was reverse correlation between epsilon GS/D and age in female hemodialysis patients. Serum bone gla protein, alkaline phosphatase and PTH-C levels were high in cases with increased epsilon GS/D and who were receiving little medication with activated Vitamin D in maintenance hemodialysis patients. A correlation was observed between delta aluminium and total medication of aluminium hydroxide-gel. Hemodialysis patients with bone pain had long term hemodialysis, high total medication of aluminium and high aluminium. Relative bone mineral contents (% epsilon GS/D, %R-BMD) were useful for estimating bone mineral content in hemodialysis patients. Hemodialysis patients were divided in four groups by PTH-C and delta aluminium levels as follow, 1) normal, 2) aluminium associated bone disease, 3) secondary hyperparathyroidism with aluminium associated bone disease, 4) secondary hyperparathyroidism. These results indicate that secondary hyperparathyroidism, and medication with aluminium may play a role in decreased bone mineral content in hemodialysis patients, and menopause may also be an important factor in female hemodialysis patients. PMID:1920939

Kohara, N

1991-06-01

321

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

SciTech Connect

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

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

1988-01-01

322

Hearing protection for miners  

SciTech Connect

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

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

2008-10-15

323

Treatment of premenopausal women with low bone mineral density  

Microsoft Academic Search

Interpretation of bone mineral density (BMD) results in premenopausal women is particularly challenging, because the relationship\\u000a between BMD and fracture risk is not the same as for postmenopausal women. Z scores rather than T scores should be used to\\u000a define “low BMD” in premenopausal women. The finding of low BMD in a premenopausal woman should prompt an evaluation for secondary

Adi Cohen; Elizabeth Shane

2008-01-01

324

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

325

Acidophiles in bioreactor mineral processing  

Microsoft Academic Search

Mineral processing in bioreactors has become established in several countries during the past decade with industrial application\\u000a of iron- and sulfur-oxidizing bacteria to release occluded gold from mineral sulfides. Cobalt extraction in bioreactors has\\u000a also been commercialized, and development of high-temperature biooxidation of copper sulfides has reached pilot-plant scale.\\u000a A variety of potentially useful mineral sulfide-oxidizing thermophiles have been recognized,

P. R. Norris; N. P. Burton; N. A. M. Foulis

2000-01-01

326

Mineral Dust and Climate  

NASA Astrophysics Data System (ADS)

Working Group on Dust and Climate Joint INQUA/QUEST Workshop; Villefranche-sur-Mer, France, 19-22 October 2008; Mineral aerosol (referred to here as “dust”) is an active climate and paleoclimate system component that may significantly influence the radiative properties of the atmosphere, as well as ocean and atmospheric carbon dioxide (CO2) concentrations, through processes such as iron fertilization. The integrative, cross-cutting examination of the role and significance of dust provides the rationale for the Dust Indicators and Records of Terrestrial and Marine Paleoenvironments (DIRTMAP) working group sponsored by the International Union of Quaternary Research and the Natural Environment Research Council's Quantifying and Understanding the Earth System (QUEST) program. The working group aims to initiate coordinated progress to improve the representation of dust properties in dust cycle models, with particular focus on dust mineralogy, such as the concentrations of iron oxides and oxyhydroxides as either nanoparticles or mineral coatings, and particle size distribution. These two sets of factors are potentially significant in assessing the effects of dust on both radiative forcing and biogeochemical cycling. The working group also aims to improve model simulation of dust source regions, the episodic nature of dust emissions, and amounts of dust deposition over the continents.

Maher, Barbara A.; Harrison, Sandy P.

2009-04-01

327

Personalizing Secondary Curriculum  

ERIC Educational Resources Information Center

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

Bailey, William J.

1974-01-01

328

Minerals Bill introduced in House  

NASA Astrophysics Data System (ADS)

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

Richman, Barbara T.

329

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.

330

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

331

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.

Keshavan, Matcheri S; Kaneko, Yoshio

2013-01-01

332

Quantifying Mineralization Utilizing Bone Mineral Density Distribution in the Mandible  

PubMed Central

Background Microcomputed Tomography (?CT) is an efficient method for quantifying the density and mineralization of mandibular microarchitecture. Conventional radiomorphometrics such as Bone and Tissue Mineral Density are useful in determining the average, overall mineral content of a scanned specimen; however, solely relying on these metrics has limitations. Utilizing Bone Mineral Density Distribution (BMDD), the complex array of mineralization densities within a bone sample can be portrayed. This information is particularly useful as a computational feature reflective of the rate of bone turnover. Here we demonstrate the utility of BMDD analyses in the rat mandible and generate a platform for further exploration of mandibular pathology and treatment. Methods Male Sprague Dawley rats (n=8) underwent ?CT and histogram data was generated from a selected volume of interest. A standard curve was derived for each animal and reference criteria were defined. An average histogram was produced for the group and descriptive analyses including the means and standard deviations are reported for each of the normative metrics. Results Mpeak (3444 Hounsfield Units, SD =138) and Mwidth (2221 Hounsfield Units SD =628) are two metrics demonstrating reproducible parameters of BMDD with minimal variance. A total of eight valuable metrics quantifying biologically significant events concerning mineralization are reported. Conclusion Here we quantify the vast wealth of information depicted in the complete spectrum of mineralization established by the BMDD analysis. We demonstrate its potential in delivering mineralization data that encompasses and enhances conventional reporting of radiomorphometrics. Moreover, we explore its role and translational potential in craniofacial experimentation.

Donneys, Alexis; Nelson, Noah S.; Deshpande, Sagar S.; Boguslawski, Matthew J.; Tchanque-Fossuo, Catherine N.; Farberg, Aaron S.; Buchman, Steven R.

2012-01-01

333

Sulfate Mineral Paragenesis in Pennsylvanian Rocks and The Occurrence of Slavikite in Nebraska  

Microsoft Academic Search

The acid weathering of pyrite-bearing Pennsylvanian clastic sedimentary rocks in southeastern Nebraska locally produces the secondary sulfate minerals alunogen, copiapite, epsomite, felsobanyaite\\/basaluminite, gypsum, halotrichite, jarosite, rozenite, and slavikite. Of these mineral occurrences, four are first-time discoveries in the state or the surrounding region. Slavikite (NaMg2Fe5 (S04)7 (OH) 6• 33H20), which has been reported only once before in North America and

Robert Matthew Joeckel; K. D. Wally; S. A. Fischbein; P. R. Hanson

2007-01-01

334

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

335

Nitrogen Mineralization and Assimilation at Millimeter Scales  

SciTech Connect

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

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

2006-11-15

336

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.

337

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

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

1981-01-01

338

Marine Mineral Exploration  

NASA Astrophysics Data System (ADS)

This book is the forty-first in the Elsevier Oceanography Series, and with it the series has come full circle. Its first title, published in 1964, was John Mero's landmark study The Mineral Resources of the Sea [Mero, 1964]. Looking back at that first major treatise and comparing it with this and other recent books on the topic [e.g., Teleki et al., 1987] one cannot help but be impressed with how well Mero used the sparse data and studies that had been put together by his time. Twenty-two years and many millions of dollars later a substantial mining-oriented base of knowledge has been built — we know much more about the economics and the engineering — yet the basic premises and conclusions that Mero assembled are still intact, and answers to the fundamental questions (e.g., formation processes for manganese nodules) are not in much better condition than they were then.

Spiess, Fren N.

339

Pneumoconiosis of shale miners.  

PubMed

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. PMID:7314011

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

1981-06-01

340

Mineral mining machines  

SciTech Connect

A mineral mining machine incorporates a guideway defining runs for a cutter chain which carries cutter picks. The guideway is movable as a whole and is formed with runs for the chain. The runs of the guideway are of generally l-shaped cross section, although the invention is not so limited, and have relatively outer and relatively inner supporting guide surfaces for the cutter chain. The relatively inner guide surface is positioned to the rear of the drive member, E.G. A sprocket, for the chain, I.E. Behind the center line of the chain in the cutting direction. The guide surfaces are continuous around the whole of the guideway thus providing continuous support for the chain during the whole of its movement around the guideway.

Higgs, R.H.; Nicholls, J.T.; Oven, T.

1980-06-24

341

Asymmetric mineral mining plough  

SciTech Connect

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

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

1981-07-28

342

Minerals yearbook, 1988: Thorium  

SciTech Connect

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

Hedrick, J.B.

1988-01-01

343

Nell-1 Enhanced Bone Mineralization.  

National Technical Information Service (NTIS)

This invention pertains to the discovery that the human NELL-1 gene induces or upregulates bone mineralization. The NELL-1 gene or gene product thus provides a convenient target for screening for modulators of bone mineralization. In addition, NELL-1 can ...

K. Ting

2003-01-01

344

Compensation of Navajo Uranium Miners  

NSDL National Science Digital Library

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

Project, World I.

345

Origin of Oceanic Manganese Minerals  

Microsoft Academic Search

A criterion is suggested for discrimination between ferromanganese oxide minerals, deposited after the introduction of manganese and associated elements in sea water solution at submarine vulcanism, and minerals which are slowly formed from dilute solution, largely of continental origin. The simultaneous injection of thorium into the ocean by submarine vulcanism is indicated, and its differentiation from continental thorium introduced into

G. Arrhenius; J. Mero; J. Korkisch

1964-01-01

346

Ways to defuse miners' anger  

SciTech Connect

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

Not Available

1984-06-01

347

From Mountain Men to Miners.  

ERIC Educational Resources Information Center

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

Stevens, Robert L.; Fogel, Jared A.

1999-01-01

348

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

349

Variability of Minerals in Foods  

Microsoft Academic Search

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

Jean A. T. Pennington

350

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

351

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.

Norris, P. R.; Burton, N. P.; Foulis, N. A.; Inc., Springer-Verlag T.

352

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

353

From Mountain Men to Miners.  

ERIC Educational Resources Information Center

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

Stevens, Robert L.; Fogel, Jared A.

1999-01-01

354

Mineral Resources and the Economy  

Microsoft Academic Search

The economic strength of the modern state and accelerated rates of technical progress depend largely on the scale and effeciency of the use of the mineral wealth extracted from the earth. At present there is hardly a single branch of industry that does not make direct or indirect use of mineral raw materials. Powerful thermal power stations, metallurgical production units,

G. Mirlin

1984-01-01

355

Pulmonary complications in lead miners  

SciTech Connect

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

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

1989-07-01

356

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

357

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 CO2 to form geologically stable, naturally occurring solid carbonate minerals. The research included resource evaluation, kinetic studies, process development, and economic evaluation. An initial cost estimate of ~$69/ton of CO2 sequestered was improved with process improvements to ~$54/ton. The scale of ex situ mineral carbonation operations, requiring ~55 000 tons of mineral to carbonate, the daily CO2 emissions from a 1-GW, coal-fired power plant, may make such operations impractical.

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

2007-04-01

358

Microtexture of Strain in electroplated copper interconnects  

SciTech Connect

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

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

2001-04-01

359

Effective hydrodynamic boundary conditions for microtextured surfaces  

NASA Astrophysics Data System (ADS)

Understanding the influence of topographic heterogeneities on liquid flows has become an important issue with the development of microfluidic systems, and more generally for the manipulation of liquids at the small scale. Most studies of the boundary flow past such surfaces have concerned poorly wetting liquids for which the topography acts to generate superhydrophobic slip. Here we focus on topographically patterned but chemically homogeneous surfaces, and measure a drag force on a sphere approaching a plane decorated with lyophilic microscopic grooves. A significant decrease in the force compared with predicted even for a superhydrophobic surface is observed. To quantify the force we use the effective no-slip boundary condition, which is applied at the imaginary smooth homogeneous isotropic surface located at an intermediate position between the top and bottom of grooves. We relate its location to a surface topology by a simple, but accurate analytical formula. Since grooves represent the most anisotropic surface, our conclusions are valid for any texture, and suggest rules for the rational design of topographically patterned surfaces to generate desired drag.

Mongruel, Anne; Chastel, Thibault; Asmolov, Evgeny S.; Vinogradova, Olga I.

2013-01-01

360

May Long Term Oxcarbazepine Treatment Be Lead to Secondary Hyperparathyroidism?  

PubMed Central

Background and Purpose The adverse effects of newer antiepileptic drugs are not well-known. This study assessed the impact of oxcarbazepine (OXC) treatment on bone turnover. Methods Forty-four children with idiopathic focal (and/or secondarily generalized) epilepsy who had been treated with OXC for more than 1 year were compared with 33 healthy, age- and sex-matched children. Serum calcium, phosphorus, alkaline phosphatase, parathyroid hormone, osteocalcin, calcitonin, and 25-hydroxyvitamin D, and bone mineral density were measured to evaluate and compare bone mineralization between the two groups. Results The serum levels of calcium, osteocalcin, 25-hydroxyvitamin D, and bone mineral density did not differ significantly between the study and control groups. However, serum levels of parathyroid hormone, alkaline phosphatase, phosphorus, and calcitonin differed significantly between the two groups. Conclusions These findings suggest that OXC treatment leads to secondary hyperparathyroidism with high-turnover bone disease and/or impaired intestinal calcium absorption.

Babacan, O.; Vurucu, S.; Yesilkaya, E.; Yesilyurt, O.; Cayci, T.; Gulgun, M.; Unay, B.; Ak?n, R.; Ozcan, O.

2012-01-01

361

Secondary prevention of stroke.  

PubMed

Stroke and transient ischemic attacks result from a range of mechanisms. Secondary prevention includes both conventional approaches to vascular risk-factor management (blood pressure lowering, cholesterol reduction with statins, smoking cessation and antiplatelet therapy) and more specific interventions, such as carotid endarterectomy or anticoagulation for atrial fibrillation. The relative importance of even conventional risk factors in stroke differs from coronary artery disease. Large clinical trials produce information on most aspects of stroke prevention. Stroke and transient ischemic attacks are now recognized as medical emergencies, with a high early risk of recurrence, and evidence is accumulating to support the importance of immediate institution of secondary preventative treatments. We review current literature on the secondary prevention of stroke. PMID:19764863

MacDougall, Niall J J; Amarasinghe, Sanjay; Muir, Keith W

2009-09-01

362

Continuous miners mine more than coal  

SciTech Connect

The paper describes the application of continuous miners and roadheaders in mineral and metal mining. Tables provide detailed information on continuous miners and roadheaders available from US and European manufacturers.

Chadwick, J.R.

1983-09-01

363

43 CFR 3861.3 - Mineral surveyors.  

Code of Federal Regulations, 2012 CFR

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

2012-10-01

364

Secondary syphilis and HIV  

PubMed Central

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

Dhaliwal, Shagun; Patel, Mahir

2012-01-01

365

Vienna RNA secondary structure server  

Microsoft Academic Search

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

Ivo L. Hofacker

2003-01-01

366

Sulfide Mineral Surfaces  

SciTech Connect

The past twenty years or so have seen dramatic development of the experimental and theoretical tools available to study the surfaces of solids at the molecular (?atomic resolution?) scale. On the experimental side, two areas of development well illustrate these advances. The first concerns the high intensity photon sources associated with synchrotron radiation; these have both greatly improved the surface sensitivity and spatial resolution of already established surface spectroscopic and diffraction methods, and enabled the development of new methods for studying surfaces. The second centers on the scanning probe microscopy (SPM) techniques initially developed in the 1980's with the first scanning tunneling microscope (STM) and atomic force microscope (AFM) experiments. The direct 'observation' of individual atoms at surfaces made possible with these methods has truly revolutionized surface science. On the theoretical side, the availability of high performance computers coupled with advances in computational modeling has provided powerful new tools to complement the advances in experiment. Particularly important have been the quantum mechanics based computational approaches such as density functional theory (DFT), which can now be easily used to calculate the equilibrium crystal structures of solids and surfaces from first principles, and to provide insights into their electronic structure. In this chapter, we review current knowledge of sulfide mineral surfaces, beginning with an overview of the principles relevant to the study of the surfaces of all crystalline solids. This includes the thermodynamics of surfaces, the atomic structure of surfaces (surface crystallography and structural stability, adjustments of atoms at the surface through relaxation or reconstruction, surface defects) and the electronic structure of surfaces. We then discuss examples where specific crystal surfaces have been studied, with the main sulfide minerals organized by structure type (galena, sphalerite, wurtzite, pyrite, pyrrhotite, covellite and molybdenite types). Some examples of more complex phases, where fracture surfaces of unspecified orientation have been studied, are then discussed (millerite, marcasite, chalcopyrite, arsenopyrite, and enargite) before a brief summary of possible future developments in the field. In this chapter, the focus is on the nature of the pristine surface, i.e., the arrangement of atoms at the surface, and the electronic structure of the surface. This is an essential precursor to any fundamental understanding of processes such as dissolution, precipitation, sorption/desorption, or catalytic activity involving the sulfide surface at an interface with a fluid phase.

Rosso, Kevin M.; Vaughan, David J.

2006-08-01

367

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.

Ramakrishna, Akula; Ravishankar, Gokare Aswathanarayana

2011-01-01

368

Effects of the calcimimetic cinacalcet HCl on cardiovascular disease, fracture, and health-related quality of life in secondary hyperparathyroidism  

Microsoft Academic Search

Effects of the calcimimetic cinacalcet HCl on cardiovascular disease, fracture, and health-related quality of life in secondary hyperparathyroidism. Background. Secondary hyperparathyroidism (HPT) and ab- normal mineral metabolism are thought to play an important role in bone and cardiovascular disease in patients with chronic kidney disease. Cinacalcet, a calcimimetic that modulates the calcium-sensing receptor, reduces parathyroid hormone (PTH) secretion and lowers

JOHN CUNNINGHAM; M ARK DANESE; K URT OLSON; P RESTON KLASSEN; GLENN M. CHERTOW

2005-01-01

369

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

370

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

NASA Astrophysics Data System (ADS)

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

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

2009-05-01

371

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.

372

Mineral evolution of bone.  

PubMed

A study on the evolution with age of the mineral composition of bones was performed on samples belonging to human and other common mammalian species (cattle, sheep, dog). The study was carried out on the ashes obtained by calcination of the bone samples (1 h at 900 degrees C). The calcined powders were carefully examined by X-ray diffraction, from which precise quantitative evaluation (also confirmed by chemical analysis) of the crystalline phases present was derived. These data were analysed as a function of the introduced fractional age phi, a new relative scale that allows even largely different lifespan species to be compared. An overall linear increase in (Ca + Mg)/P ratio with log phi was found and the other considerations on molecular constitution (especially as regards Mg2+ substituting for Ca2+ in very young subjects) of the various phases detected were formulated and relative implications evaluated. The results appear promising for an improvement of knowledge in the field of biomedical experimentation and clinical implantology. PMID:8652780

Ravaglioli, A; Krajewski, A; Celotti, G C; Piancastelli, A; Bacchini, B; Montanari, L; Zama, G; Piombi, L

1996-03-01

373

Miner's rule revisited  

NASA Astrophysics Data System (ADS)

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

Schuetz, W.; Heuler, P.

1994-03-01

374

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

375

Modernising Portugal's Secondary Schools  

ERIC Educational Resources Information Center

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

Heitor, Teresa V.

2008-01-01

376

Secondary oil recovery process  

Microsoft Academic Search

A secondary recovery process is described which employs the steps of (1) injecting into the formation via an injection well a solution of a polymerized methacrylate in a water-miscible solvent, and (2) recovering from the formation oil displaced by the injected solution via the production well. Optionally, after step (1), a hydrocarbon fluid can be injected via the injection well

A. Brown; S. F. Hager; M. Chichakli; C. H. Wu

1977-01-01

377

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

378

Secondary Lithium Batteries.  

National Technical Information Service (NTIS)

It has been discovered that some fusible alloys composed of Bi, Pb, Sn and Cd exhibit good characteristics as the material of the negative electrode of secondary lithium batteries. The alloy electrode allows charging and discharging by such reaction to ab...

Y. Toyoguchi J. Yamaura T. Matsui N. Koshiba T. Shigematsu

1986-01-01

379

Secondary Syphilitic Lesions  

PubMed Central

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

Baughn, Robert E.; Musher, Daniel M.

2005-01-01

380

Secondary Dance Instructional Guide.  

ERIC Educational Resources Information Center

|This manual provides guidelines for dance teachers in secondary schools. A brief statement is made on the purpose and philosophy of dance education, and activities and instructional suggestions are presented for various dance forms: (1) group dance--folk/ethnic, square dance, and social dance; (2) aerobic dance; (3) jazz dance; (4) modern dance;…

Montgomery County Public Schools, Rockville, MD. Dept. of Instructional Planning and Development.

381

Secondary Emission Multiplier Structure.  

National Technical Information Service (NTIS)

The secondary emission multiplier structure is for use in electron tubes wherein there is an electron-optical image, such as image intensifier tubes. The structure consists of a plurality of plates or sheets of material each having a number of tapered con...

E. W. Poor

1965-01-01

382

Secondary alkaline batteries  

SciTech Connect

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

McBreen, J.

1984-03-01

383

[Postrubella secondary pigmentary retinopathy].  

PubMed

The paper presents the case of an 11 years-old child with secondary pigmentary retinopathy, atrial septal defect, facial dysmorphia with mandibular hypoplasia: all these malformations are part of the congenital rubeola syndrome. The patient has a twin brother presenting similar manifestations, but having a different expressivity. PMID:8338828

Nicu, C; Damian, C; Glavici, M

384

Secondary metabolism in tobacco  

Microsoft Academic Search

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

Laurentius H. Nugroho; Robert Verpoorte

2002-01-01

385

Health Hazard Evaluation Report, St. Joe Mineral Corp., Herculaneum, Missouri: Addendum to Health Hazard Evaluation Final Report No. 77-87-440.  

National Technical Information Service (NTIS)

This Herculaneum, MO. facility of the St. Joe Mineral Corp. is primarily involved in the production of lead metal ingots from lead ore (galena) concentrate. Sulfuric acid, zinc and silver are secondary products of this lead smelting process. Normal daily ...

1977-01-01

386

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

SciTech Connect

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

Kimbell, C.L.

1991-12-31

387

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

SciTech Connect

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

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

2005-07-05

388

Electrochemical Dissolution of Pentlandite Minerals,  

National Technical Information Service (NTIS)

The dissolution behavior of pentlandite-type minerals was studied by using synthetic iron-nickel and cobalt pentlandites. From conventional direct current experiments, it was found that temperature and oxidation potential affect dissolution behavior. The ...

J. Aromaa

1988-01-01

389

Chemical Properties of Bone Mineral.  

National Technical Information Service (NTIS)

The literature on the chemical properties of bone mineral is reviewed. As a basis for understanding the properties of these extremely fine crystallites, reference is made first to the ideal compounds and then to the morphological, compositional, and struc...

W. E. Brown L. C. Chow

1976-01-01

390

Preparation of Synthetic Standard Minerals.  

National Technical Information Service (NTIS)

A number of techniques for synthetic mineral preparations have been examined. These techniques include hot-pressing in graphite dies at moderate pressures, high-pressure, high-temperature synthesis in a piston and cylinder apparatus, isostatic pressing un...

C. C. Herrick S. J. Bustamante R. W. Charls R. E. Cowan E. A. Hakkila

1978-01-01

391

Mining, Minerals and Sustainable Development  

NSDL National Science Digital Library

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

2007-06-25

392

Classroom Dangers of Toxic Minerals.  

ERIC Educational Resources Information Center

|Describes potentially dangerous classroom situations involving toxic minerals. The intent of the article is to make students aware of the dangers so that they may act responsibly in health-related decisions as professional geologists. (Author/SA)|

Puffer, John H.

1979-01-01

393

Physical fitness in lignite miners.  

PubMed

The purpose of this study was to determine physical fitness level of lignite miners in the Czech Republic. The authors have examined a representative group of 152 active lignite miners by bicycle spiroergometry. The duration of employment in coal mines ranged between 5 and 32 years. The average age was 43.1 +/- 4.7 years. The miners had an average peak oxygen consumption 2.9 +/- 0.5 l.min-1, corresponding to 99.7 +/- 20.4% of the predicted maximal oxygen consumption. Physical fitness of lignite miners was comparable with reference values for healthy men in Czech population. The level of physical fitness did not correlate with the length of exposure to underground work. PMID:7698905

Brhel, P; Homolka, P; Kratochvílová, J; Bärtlová, E

1994-01-01

394

Highwall miners pursue thinner seams  

SciTech Connect

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

Fiscor, S.

2006-04-15

395

Dietary phytate and mineral bioavailability  

Microsoft Academic Search

The relation between the dietary phytate (InsP6), mineral status and InsP6 levels in the organism, using three controlled diets (AIN-76A, AIN-76A + 1% phytate, AIN-76A + 6% carob seed germ), are studied. AIN-76A is a purified diet in which InsP6 is practically absent. No important or significant differences in the mineral status (Zn, Cu, Fe) of blood, kidneys, liver, brain

Felix Grases; Bartolome Miguel Simonet; Rafael Maria Prieto; Juan Gabriel March

2001-01-01

396

Nitrogen Mineralization Under Saline Conditions  

Microsoft Academic Search

The conversion of soil nitrogen (N) from its organic into inorganic forms has been the subject of several investigations, but information on N mineralization in saline soil is scanty. The study was therefore carried out to observe trends in N mineralization in saline soils amended with manure and urea. The electrical conductivity (ECe) of saline soils was 0.2 (S0), 4.1

M. Irshad; T. Honna; S. Yamamoto; A. E. Eneji; N. Yamasaki

2005-01-01

397

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

398

Secondary aortoduodenal fistula.  

PubMed

Secondary aortoenteric fistula (SAF) is now recognized as an uncommon but exceedingly important complication of abdominal aortic reconstruction. The complication often occurs months to years after the original surgery. The main clinical manifestation of the disease is always upper gastrointestinal bleeding. Treatment of the disease is early surgical intervention. The mortality is high if no prompt operation. We present a case of secondary aortoduodenal fistula (SADF) found 20 days after aortic reconstructive surgery, with the clinical presentation of upper gastrointestinal bleeding. Even immediate exploratory laparotomy was performed, the patient died 48 hrs after the surgical management. Because of the increasing number of elective aortic aneurysm repairs in the aging population, it is likely that more patients with SAF will present to the clinical physicians in the future. So, a high index of suspicion is necessary for prompt diagnosis and treatment of this actually life-threatening event. PMID:12479626

Chang, Meng-Wei; Chan, Yi-Ling; Hsieh, Hung-Chang; Chang, Shy-Shin

2002-09-01

399

Nitrification and nitrogen mineralization in a lowland rainforest succession in Costa Rica, Central America  

Microsoft Academic Search

Nitrogen availability is a critical component of productivity in successional lowland rainforests, and nitrogen losses from a given system may largely depend on rates of nitrification in soils of the system. Two hypotheses were tested in a study of a 6-point secondary rainforest sere in the coastal lowlands of Costa Rica: that nitrification and N mineralization change in a directed

G. Philip Robertson

1984-01-01

400

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

401

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

402

Chemical differences between minerals from mineralizing and barren intrusions associated with molybdenum mineralization at Climax, Colorado  

Microsoft Academic Search

Summary At Climax, comagmatic igneous intrusions can be subdivided into two groups, mineralizing stocks which are parent intrusions for Mo orebodies and barren stocks. Magmatic biotites in mineralizing stocks are similar to hydrothermal biotites in that they contain a greater proportion of Si-enriched and Ti-depleted compositional domains than do magmatic biotites in barren stocks. A similar trend of Si-enrichment correlated

D. A. F. Hendry; A. J. Gunow; R. P. Smith; S. J. B. Reed; J. V. P. Long

1988-01-01

403

Secondary School Advisors as Mentors and Secondary Attachment Figures  

ERIC Educational Resources Information Center

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

Van Ryzin, Mark

2010-01-01

404

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

405

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

Code of Federal Regulations, 2010 CFR

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

2009-04-01

406

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

Code of Federal Regulations, 2010 CFR

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

2010-04-01

407

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

Code of Federal Regulations, 2011 CFR

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

2011-04-01

408

Recovering byproduct heavy minerals from sand and gravel, placer gold, and industrial mineral operations  

Microsoft Academic Search

The Bureau of Mines, as part of an effort to maximize minerals and metals recovery from domestic resources, has investigated the feasibility of recovering heavy minerals as byproducts from sand and gravel, placer gold, and industrial mineral operations in northern California. Sand samples from about 50 locations were treated by gravity separation to yield heavy-mineral cocentrates (black sands). Mineral compositions

J. M. Gomes; G. M. Martinez; M. M. Wong

1979-01-01

409

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

Code of Federal Regulations, 2012 CFR

...2012-10-01 false Minerals soluble in water; brines; minerals taken in solution...Methods § 3594.5 Minerals soluble in water; brines; minerals taken in solution...potassium or other minerals soluble in water, all wells, shafts, prospecting...

2012-10-01

410

Secondary or Reactive AA Amyloidosis  

MedlinePLUS

Secondary AA Secondary amyloidosis is caused by a chronic infection or chronic inflammatory disease. The deposits in this type ... are made up of a protein called the AA protein. Medical or surgical treatment of the underlying ...

411

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

412

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

413

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.

414

Mineral Abundances in Martian Soils  

NASA Astrophysics Data System (ADS)

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

Martel, L. M. V.

2011-01-01

415

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

SciTech Connect

The Canadian mining industry made impressive gains in 1988. The strong momentum was expected to continue through 1989. Mining is a thriving industry within the Canadian economy. Canada is among the world's mining leaders, but mining is not its leading industry; it contributes 25% of the total value of Canada's exports. In 1988, mining employed about 392,000 workers, an increase of 6,000 workers from 1987. Topics discussed in the report include the following: Government policies and programs; Production; Trade; Commodity review--metals, industrial minerals, and mineral fuels.

Gurmendi, A.C.

1988-01-01

416

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

NASA Astrophysics Data System (ADS)

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.

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

2011-03-01

417

Water concentrations in mantle peridotite minerals  

NASA Astrophysics Data System (ADS)

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

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

2010-12-01

418

Uranium mineralization in the two mica granite of gabal Ribdab area, South Eastern Desert, Egypt.  

PubMed

Among the different rock units in the Gabal Ribdab area, the two-mica leucogranite and muscovite pegmatitic granite are the most favourable host rocks for uranium and thorium mineralization. The muscovite pegmatitic granite shows evidence of post-magmatic alteration, e.g. Na- and K-metasomatism, whereas the two-mica leucogranite could be regarded as being fresh. The spectrometric survey revealed the presence of three enriched zones with a maximum eU content of 140 ppm and the maximum eTh is 36 ppm. Uranophane, zippeite and becquerelite are the most abundant uranium minerals. The origin of these secondary minerals is mainly related to alteration of primary minerals by the action of oxidizing fluids, mobilization of uranium and then redeposition in other forms. Redistribution by circulating meteoric waters might have taken place. PMID:11761111

Ibrahim, M E; Saleh, G M; Abd El-Naby, H H

2001-12-01

419

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

420

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

421

Selected readings in mineral economics  

SciTech Connect

In a rapidly expanding and changing field, these papers provide an overview and reference of practical issues and theoretical developments in Canadian mineral economics. A partial table of contents is: Reflections on the ''expanded reserves'' concept: Mineral exploration productivity: focusing to restore profitability: COALMOD: a financial analysis and policy simulation model for coal mining developments: Option pricing: a new approach to mine valuation: Recent New Brunswick agreements for oil shale and potash: unique arrangements or the beginning of a trend: Flow-through shares-a good deal better: Structural change and depression in world metal industries: Micro issues but macro impacts - strategic problems in a turbulent mineral environment: and Innovative financing in the metal mining industry: meeting the financial challenge - the Northgate experience.

Anderson, F.J.

1987-01-01

422

Mineral Status of Myocardial Sarcocystosis  

PubMed Central

Background The role of minerals on parasite persistency and the interaction between minerals and animal responses to the parasite infestation is not clear. For these reasons, the present research was aimed to compare copper, zinc and iron status in sheep with parasitic myocarditis and healthy ones in 2009. Methods Blood and heart tissue samples were collected from 145 slaughtered sheep and histopathological findings were confirmed as myocardial sarcocystosis in 27 cases. Serum and tissue mineral level were determined by atomic absorption spectroscopy. Data were analyzed by Sigmastat program, using One Way Analysis of Variance (ANOVA) at the level of P<0.05. Results Myocardial sarcocystosis significantly increase myocardial concentration of Cu, Zn and Fe (P<0.05). Conclusion These findings may explain the role of copper, zinc and iron in parasite persistency and may discuss the pathogenesis of sarcocystosis, which relates to evocate mentioned micronutrient to cardiac muscle.

Kojouri, GA; Aghajani, E; Jahanabadi, S; Kojouri, A

2011-01-01

423

Mineral Abundance Near Aristarchus Crater  

NASA Astrophysics Data System (ADS)

Mineral Abundance Near Aristarchus Crater Alison Bradford and Alex Storrs Towson University We analyze Hubble Space Telescope (HST) images to determine the abundance of minerals near Aristarchus crater. Following the calibration of Robinson et al. (2007) we present ratio maps of images obtained in August of 2005 showing the abundance of TiO2 and other minerals in this interesting area in the middle of Oceanus Procellarum. A prominent cleft (Schroter's Valley, presumably a collapsed lava tube) makes this region of special interest for analyzing the formation of mare basalts. Reference: Robinson, M.S., et al. (2007): "High resolution mapping of TiO2 abundances on the Moon using the Hubble Space Telescope", GRL 34, L13203

Bradford, Alison; Storrs, A.

2007-12-01

424

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

2007-04-05

425

Secondary homoclinic bifurcation theorems.  

PubMed

We develop criteria for detecting secondary intersections and tangencies of the stable and unstable manifolds of hyperbolic periodic orbits appearing in time-periodically perturbed one degree of freedom Hamiltonian systems. A function, called the "Secondary Melnikov Function" (SMF) is constructed, and it is proved that simple (resp. degenerate) zeros of this function correspond to transverse (resp. tangent) intersections of the manifolds. The theory identifies and predicts the rotary number of the intersection (the number of "humps" of the homoclinic orbit), the transition number of the homoclinic points (the number of periods between humps), the existence of tangencies, and the scaling of the intersection angles near tangent bifurcations perturbationally. The theory predicts the minimal transition number of the homoclinic points of a homoclinic tangle. This number determines the relevant time scale, the minimal stretching rate (which is related to the topological entropy) and the transport mechanism as described by the TAM, a transport theory for two-dimensional area-preserving chaotic maps. The implications of this theory on the study of dissipative systems have yet to be explored. (c) 1995 American Institute of Physics. PMID:12780192

Rom-Kedar, Vered

1995-06-01

426

The scaling of secondary craters  

NASA Astrophysics Data System (ADS)

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

Croft, Steven K.

1991-06-01

427

Viewing minerals, atom by atom  

NASA Astrophysics Data System (ADS)

With state-of-the-art technology supported by scissors and bungy cords, Earth scientists are beginning to look at mineral surfaces and mineral-fluid interactions on an atomic scale.The instrument that can provide such a detailed view is the scanning tunneling microscope (STM), which made a great theoretical and practical splash when it was introduced in 1981 by Gerd Binnig and Heinrich Rohrer, physicists at IBM's laboratory in Zurich. They won a Nobel Prize in Physics for their work 5 years later.

Maggs, William Ward

428

Copper isotopes as monitors of redox processes in hydrothermal mineralization  

NASA Astrophysics Data System (ADS)

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

Markl, Gregor; Lahaye, Yann; Schwinn, Gregor

2006-08-01

429

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

430

Sulfate minerals and organic compounds on Mars  

NASA Astrophysics Data System (ADS)

Strong evidence for evaporitic sulfate minerals such as gypsum and jarosite has recently been found on Mars. Although organic molecules are often codeposited with terrestrial evaporitic minerals, there have been no systematic investigations of organic components in sulfate minerals. We report here the detection of organic material, including amino acids and their amine degradation products, in ancient terrestrial sulfate minerals. Amino acids and amines appear to be preserved for geologically long periods in sulfate mineral matrices. This suggests that sulfate minerals should be prime targets in the search for organic compounds, including those of biological origin, on Mars.

Aubrey, Andrew; Cleaves, H. James; Chalmers, John H.; Skelley, Alison M.; Mathies, Richard A.; Grunthaner, Frank J.; Ehrenfreund, Pascale; Bada, Jeffrey L.

2006-05-01

431

Hydrothermal Alteration in the PACMANUS Hydrothermal Field: Implications From Secondary Mineral Assemblages and Mineral Chemistry, OPD Leg 193  

Microsoft Academic Search

Leg 193 of the Ocean Drilling Program investigated the subsurface nature of the active PACMANUS hydrothermal field in the Manus backarc basin near Papua New Guinea. Drilling in different areas on the felsic neovolcanic Pual Ridge, including the high-temperature black smoker complex of Roman Ruins and the low-temperature Snowcap site with diffusive discharge yielded a complex alteration history with a

K. S. Lackschewitz; M. Kummetz; D. Ackermand; R. Botz; C. W. Devey; A. Singer; P. Stoffers

2001-01-01

432

Noninvasive Prospecting for Lunar Minerals  

Microsoft Academic Search

The establishment of a lunar base is planned as the first step in sending humans to explore our solar system. One of the essential ingredients for supporting a manned lunar base is oxygen. Significant deposits of the mineral ilmenite, a titanium-iron oxide, are thought to occur on or near the lunar surface; oxygen can readily be extracted from ilmenite. A

John Meredith

2009-01-01

433

Silicon Oxynitride: A Meteoritic Mineral  

Microsoft Academic Search

Silicon oxynitride, a new mineral, has been discovered in the Jajh deh Kot Lalu enstatite chondrite. Nitrogen and oxygen have been measured quantitatively with an electron microprobe by means of prototypes of newly developed curved crystal detection systems. X-ray diffraction patterns were obtained from silicon oxynitride separated from the meteorite and from synthetic Si2N2O.

Christian A. Andersen; Klaus Keil; Brain Mason

1964-01-01

434

Chemical Bonding in Sulfide Minerals  

Microsoft Academic Search

An understanding of chemical bonding and electronic structure in sulfide minerals is central to any attempt at understanding their crystal structures, stabilities and physical properties. It is also an essential precursor to understanding reactivity through modeling surface structure at the molecular scale. In recent decades, there have been remarkable advances in first principles (ab initio) methods for the quantitative calculation

David J. Vaughan; Kevin M. Rosso

2006-01-01

435

Physical controls on matrix mineralization  

NASA Astrophysics Data System (ADS)

During biomineral formation, protein matrices impose order on nucleating mineral phases. While many studies have examined the structural relationships between mineral and matrix, few have explored the energetics. To address this gap we use in situ TEM and AFM to investigate calcium phosphate nucleation and growth in collagen and amelogenin matrices. In situ TEM results indicate that, in the absence of calcium, amelogenin nanospheres are loose aggregates of oligomers, while in the presence of calcium phosphate solution, can form chain-like structures and become mineralized with an amorphous phase before the appearance of crystalline phases. Results on collagen reveal the evolution of nucleation pathways from direct to indirect with increasing supersaturation and analysis of nucleation rates using classical theory demonstrates a reduction in interfacial energy due to matrix-mineral interactions. However, the calculated thermodynamic barriers are in contradiction to the observed pathways and well in excess of sensible values. We present a model based on cluster aggregation within the classical context that reconciles experiment and theory.

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

2013-03-01

436

Crystallizing Minerals from Aqueous Solutions  

NSDL National Science Digital Library

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

Perkins, Dexter

437

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

438

Rocks and Minerals: Unit Outlines  

NSDL National Science Digital Library

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

Fries-Gaither, Jessica

439

[Secondary sclerosing cholangitis].  

PubMed

Secondary sclerosing cholangitis leads to slow and often irreversible destruction of the walls of both intra- and extrahepatic bile ducts. As for primary sclerosing cholangitis, clinical signs and laboratory findings reveal cholestasis. The diagnosis is confirmed by retrograde endoscopic cholangiography which shows narrowed bile ducts and rarefied ramifications of the intra-hepatic ductal system. Several causes have been identified including infectious causes with or without a relationship to bile duct obstruction and human immunodeficiency virus infection as well as ischaemic related causes after chemotherapy, arterial embolization or liver transplantation. Other causes include chemical aggression after treatment for hydatic cysts and post-surgical complications due to a damaged bile tract. Treatment is difficult and often dependent on the cause. PMID:7638147

Amor, A; Chapoutot, C; Michel, J; Pageaux, G P; Larrey, D; Michel, H

1995-06-01

440

Secondary Globular Cluster populations  

NASA Astrophysics Data System (ADS)

This study is motivated by two facts: 1. The formation of populous star cluster systems is widely observed to accompany violent star formation episodes in gas-rich galaxies as e.g. those triggered by strong interactions or merging. 2. The Globular Cluster (GC) systems of most but not all early-type galaxies show bimodal optical color distributions with fairly universal blue peaks and somewhat variable red peak colors, yet their Luminosity Functions (LFs) look like simple Gaussians with apparently universal turn-over magnitudes that are used for distance measurements and the determination of Ho. Based on a new set of evolutionary synthesis models for Simple (= single burst) Stellar Populations (SSPs) of various metallicities using the latest Padova isochrones I study the color and luminosity evolution of GC populations over the wavelength range from U through K, providing an extensive grid of models for comparison with observations. I assume the intrinsic widths of the color distributions and LFs to be constant in time at the values observed today for the Milky Way or M 31 halo GC populations. Taking the color distributions and LFs of the Milky Way or M 31 halo GC population as a reference for old metal-poor GC populations in general, I study for which combinations of age and metallicity a secondary GC population formed in some violent star formation event in the history of its parent galaxy may or may not be detected in the observed GC color distributions. I also investigate the effect of these secondary GCs on the LFs of the total GC system. Significant differences are found among the diagnostic efficiencies in various wavelength regions. In particular, we predict the NIR to be able to reveal the presence of GC subpopulations with different age - metallicity combinations that may perfectly hide within one inconspicuous optical color peak. If the entire manifold of possible age - metallicity combinations is admitted for a secondary GC population, we find several cases where the resulting LF of the whole GC system is significantly affected and its turn-over could not serve as a reliable distance indicator. If, on the other hand, we assume some age - metallicity relation for GC populations, the second peak of the LFs vanishes and models indicate single-peak GC LFs even in GC systems with bimodal color distributions. A broad but sufficient age - metallicity relation is, for example, obtained if the secondary GC populations form in mergers of various spiral galaxy types from the ISM pre-enriched over the redshift range from z ? 4.4 to z ? 0. As a first illustrative example we apply our models to V- and I-band data presented by Larsen et al. (\\cite{Larsen2001}) for blue and red peak GCs in three early-type galaxies. We point out the importance of having multi-band information to independently constrain ages and metallicities of different GC subpopulations and again stress the diagnostic potential of K-band data in addition to optical observations. The models presented here will be used for the interpretation of multi-wavelength data on GC systems in galaxies of various types, luminosities and environments as well as on young star cluster systems in interacting galaxies and mergers. By independently constraining ages and metallicities of individual clusters we expect to shed light on both cluster and galaxy formation scenarios.

Fritze-v. Alvensleben, U.

2004-02-01

441

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

442

Mars' Magnetic Lithosphere: Candidate Minerals  

NASA Astrophysics Data System (ADS)

Mars' large southern-hemisphere magnetic anomalies require some combination of (1) a large Martian magnetic field at the time the lithosphere acquired thermoremanent magnetization (TRM), (2) large magnetic mineral concentrations compared to Earth's lithosphere, (3) a mineral or minerals whose grain size and resulting domain structure generate intense TRM, and (4) a high Curie temperature and deep Curie-point isotherm. Induced magnetization can safely be ignored because all viable candidate minerals with appropriate grain sizes and domain structures have Koenigsberger Qt ratios >>1 and the present Martian field is in any case small compared to the Earth's field. Based on the mineralogy of Martian meteorites and spectroscopy of the Martian surface, the magnetic minerals likely to be important in Mars' lithosphere are magnetite, hematite and pyrrhotite, all of which are familiar constituents of Earth's continental lithosphere. If the Martian anomalies are the integrated effect of minerals occurring over a considerable depth interval, pyrrhotite, which has a low Curie point (about 300oC) and is found only in specialized settings on Earth, is a less appealing candidate than the ubiquitous magnetite and hematite with their high Curie points (580oC and 675oC, respectively). The TRM of magnetite decreases as the inverse of increasing grain size, whereas the opposite size dependence is observed for hematite. The two minerals have approximately the same TRM intensity around grain sizes of 10-20 micrometers, which is close to both the upper limit for pseudo-single-domain (PSD) behavior in magnetite and the critical single-domain size of hematite. The lack of any substantial internal demagnetizing field in hematite permits a TRM in multidomain hematite that is orders of magnitude larger than the TRM of multidomain magnetite for field strengths like the Earth's. Either single-domain/ PSD magnetite or multidomain hematite could explain strong anomalies, with single-domain magnetite requiring less concentration but having restrictively small (submicron) grain sizes. Recently single-domain hematite has been found to have more intense TRM than previously measured, and it too could be viable. Depending on magmatic conditions, fine-grained magnetite and hematite can occur as segregated phases within titanomagnetite and titanohematite, respectively, the fineness of subdivision required for single-domain behavior being much less for hematite than for magnetite. Finally, thermoviscous magnetization, which is important for Earth's lithosphere, is probably negligible for Mars because of the small present field and the minor enhancement of TRM that is likely to have occurred in ancient fields.

Dunlop, D. J.

2003-04-01

443

Assessing the addition of mineral processing waste to green waste-derived compost: an agronomic, environmental and economic appraisal.  

PubMed

The overall aim of this study was to evaluate the benefit of mixing two large volume wastes, namely mineral processing waste and source-segregated green waste compost, on the growth performance of plants targeted towards high (horticulture/agriculture) and low (amenity/restoration) value markets. The secondary aims were to evaluate the influence of mineral waste type on plant growth performance and to undertake a simple economic analysis of the use of mineral-compost mixtures in land restoration. Our results showed that in comparison to organic wastes, mineral wastes contained a low available nutrient content which reduces compost quality. This is supported by growth trials with tomato, wheat and grass which showed that, irrespective of mineral source, plants performed poorly in compost blended with mineral waste in comparison to those grown in green waste or peat-based compost alone. In terms of consumer confidence, unlike other wastes (e.g. biosolids and construction/demolition waste) the mineral quarry wastes can be expected to be free of potentially toxic elements, however, the production costs of compost-mineral waste mixtures and subsequent transport costs may limit its widespread use. In addition, handling of the material can be difficult under wet conditions and effective blending may require the purchase of specialist equipment. From our results, we conclude that mineral fines may prove useful for low quality, low value landscaping activities close to the source of production but are unsuited to high value markets. PMID:18809319

Jones, D L; Chesworth, S; Khalid, M; Iqbal, Z

2008-09-21

444

Chemical Bonding in Sulfide Minerals  

SciTech Connect

An understanding of chemical bonding and electronic structure in sulfide minerals is central to any attempt at understanding their crystal structures, stabilities and physical properties. It is also an essential precursor to understanding reactivity through modeling surface structure at the molecular scale. In recent decades, there have been remarkable advances in first principles (ab initio) methods for the quantitative calculation of electronic structure. These advances have been made possible by the very rapid development of high performance computers. Several review volumes that chart the applications of these developments in mineralogy and geochemistry are available (Tossell and Vaughan, 1992; Cygan and Kubicki, 2001). An important feature of the sulfide minerals is the diversity of their electronic structures, as evidenced by their electrical and magnetic properties (see Pearce et al. 2006, this volume). Thus, sulfide minerals range from insulators through semiconductors to metals, and exhibit every type of magnetic behavior. This has presented problems for those attempting to develop bonding models for sulfides, and also led to certain misconceptions regarding the kinds of models that may be appropriate. In this chapter, chemical bonding and electronic structure models for sulfides are reviewed with emphasis on more recent developments. Although the fully ab initio quantitative methods are now capable of a remarkable degree of sophistication in terms of agreement with experiment and potential to interpret and predict behavior with varying conditions, both qualitative and more simplistic quantitative approaches will also be briefly discussed. This is because we believe that the insights which they provide are still helpful to those studying sulfide minerals. In addition to the application of electronic structure models and calculations to solid sulfides, work on sulfide mineral surfaces (Rosso and Vaughan 2006a,b) and solution complexes and clusters (Rickard and Luther, 2006) are discussed in detail later in this volume.

Vaughan, David J.; Rosso, Kevin M.

2006-08-01

445

34 CFR 300.36 - Secondary school.  

Code of Federal Regulations, 2013 CFR

...Secondary school. Secondary school means a nonprofit institutional day or residential school, including a public secondary charter school that provides secondary education, as determined under State law, except that it does not...

2013-07-01

446

43 CFR 3830.10 - Locatable minerals.  

Code of Federal Regulations, 2012 CFR

...Public Lands (Continued) BUREAU OF LAND MANAGEMENT, DEPARTMENT OF THE INTERIOR MINERALS MANAGEMENT (3000) LOCATING, RECORDING, AND MAINTAINING MINING CLAIMS OR SITES; GENERAL PROVISIONS Mining Law Minerals § 3830.10 Locatable...

2012-10-01

447

Standardization of Continuous Miner Control Configurations.  

National Technical Information Service (NTIS)

Continuous miners are operated in an environment that is extremely hazardous to mining personnel working in the vicinity, including the operator of the continuous miner. Every effort should be made to apply modern technology to reduce human error and acci...

J. D. Folley W. G. Hedling

1972-01-01

448

Global Flows of Metals and Minerals.  

National Technical Information Service (NTIS)

This paper provides a preliminary review of the trends in worldwide metals and industrial minerals production and consumption based on newly developed global metals and minerals Material Flow Accounts (MFA). The MFA developed encompass data on extraction ...

D. G. Rogich G. R. Matos

2008-01-01

449

[Secondary vasculitides and vasculitis mimics].  

PubMed

Secondary vasculitis is a form of vasculitis for which an underlying disease is known. Diseases associated with secondary vasculitis include infections, drug hypersensitivity, malignancy, rheumatoid arthritis, collagen vascular disease and sarcoidosis. Moreover, there are numerous conditions that can mimic vasculitis clinically, in laboratory testing, radiographically and in histopathology. It is evident that distinguishing primary vasculitis from secondary vasculitis and also vascular inflammation from non-vasculitic disorders (vasculitis mimics) has significant therapeutic implications. PMID:22956168

de Groot, K; Märker-Hermann, E

2012-11-01

450

Capture probabilities for secondary resonances  

NASA Astrophysics Data System (ADS)

The tidal evolutions of Miranda and Umbriel in the 1:3, i-squaredM resonance are presently addressed via analyses of the role of secondary resonances during tidal evolution within a j:j+2 orbit-orbit resonance. The results thus obtained allow both analytical and numerical refinement of Malhotra's (1990) results for the probability of capture into secondary resonances. Attention is given to Miranda's evolution in the case of capture into the 3/1 secondary resonance.

Henrard, Jacques; Moons, Michele

1992-02-01

451

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

PubMed

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

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

2013-06-11

452

TEACHING MINERS: BREAKING THE BARRIERS TO LEARNING  

Microsoft Academic Search

Miners, like many skilled blue-collar workers, are not traditional learners. They have not always been successful in classroom-type settings, preferring to learn on the job in a hands-on environment. U.S. law requires that miners have a minimum of 8 hours of safety training annually, plus 40 hours for underground miners and 24 hours for surface miners when they enter the

Elaine T. Cullen

453

Minerals yearbook, 1991: Massachusetts. Annual report  

SciTech Connect

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

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

1993-05-01

454

[Incidence of chronic bronchitis in coal miners].  

PubMed

An epidemiological survey of 2000 Donbass coal miners revealed data on the initial dust bronchitis prevalence and its progress. It was established that the coal miners who work in mines with steep coal strata exhibit higher bronchitis morbidity in comparison with the miners engaged in sloping strata mines. A correlation was established between dust bronchitis prevalence and length of professional service and coal miners' labour specificity. Tobacco smokers displayed a markedly higher percentage of chronic dust bronchitis cases. PMID:2379850

Valutsina, V M; Kiva, A I

1990-01-01

455

Does it matter how parathyroid hormone levels are suppressed in secondary hyperparathyroidism?  

PubMed

Because secondary hyperparathyroidism is associated with morbidity and mortality in patients with chronic kidney disease, suppression of parathyroid hormone (PTH) and minimization of associated derangements in mineral metabolism are cardinal therapeutic goals. There is an ongoing debate regarding the proper treatment strategy for PTH suppression in this population. While some practitioners believe that calcitriol analogues should be the primary therapy in this setting, others contend that calcimimetics offer unique treatment benefits. Recent advancements in the understanding of the pathophysiology of secondary hyperparathyroidism and the secondary effects of these agents may help clarify this debate. Here, we review the classical actions of calcitriol analogues and calcimimetics on mineral metabolism. We also examine the potential nonclassical effects of these therapies on the renin-angiotensin-aldosterone system, proteinuria, vascular calcification, fibroblast growth factor-23, inflammation, and overall survival. PMID:21682772

Stubbs, Jason R; Wetmore, James B

456

Vitamins and minerals in HIV infection  

Microsoft Academic Search

THE ROLE OF VITAMINS AND MINERALS in the clinical manifestation of human immunodeficiency virus (HIV) infection has not been well defined. However, a growing number of studies have suggested important links between vitamins and trace minerals and HIV infection. Certain vitamins and trace minerals are frequently deficient in patients who have HIV infection. Selected states of vitamin deficiency appear to

Gregg Coodley; Donald E. Girard

1991-01-01

457

Minerals, national security, and foreign policy  

Microsoft Academic Search

As the world's principal minerals-consuming nation, the United States has a long history of concern about access to the minerals necessary to the functioning of its economy and maintaining a strong national defense (Eckes, 1979). These concerns first arose after World War I when the nation recognized that it was not self-sufficient in all of the minerals it needed. Although

W. David Menzie

1997-01-01

458

Minerals by Physical and Optical Properties  

NSDL National Science Digital Library

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

Barthelmy, David

459

Mineral matter identification of some Turkish lignites  

SciTech Connect

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

Yaman, S.; Taptik, Y.; Kuecuekbayrak, S.; Kadioglu, E. [Istanbul Technical Univ. (Turkey). Chemical and Metallurgical Engineering Faculty

1995-01-01

460

Introduction to Crystallography and Mineral Crystal Systems  

NSDL National Science Digital Library

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

Keller, Bob