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Sample records for skarn deposits mesa

  1. Genetic relationships between skarn ore deposits and magmatic activity in the Ahar region, Western Alborz, NW Iran

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    Mollai Habib

    2014-06-01

    Full Text Available Paleocene to Oligocene tectonic processes in northwest Iran resulted in extensive I-type calc-alkaline and alkaline magmatic activity in the Ahar region. Numerous skarn deposits formed in the contact between Upper Cretaceous impure carbonate rocks and Oligocene-Miocene plutonic rocks. This study presents new field observations of skarns in the western Alborz range and is based on geochemistry of igneous rocks, mineralogy of the important skarn deposits, and electron microprobe analyses of skarn minerals. These data are used to interpret the metasomatism during sequential skarn formation and the geotectonic setting of the skarn ore deposit related igneous rocks. The skarns were classified into exoskarn, endoskarn and ore skarn. Andraditic garnet is the main skarn mineral; the pyroxene belongs to the diopside-hedenbergite series. The skarnification started with pluton emplacement and metamorphism of carbonate rocks followed by prograde metasomatism and the formation of anhydrous minerals like garnet and pyroxene. The next stage resulted in retro gradation of anhydrous minerals along with the formation of oxide minerals (magnetite and hematite followed by the formation of hydrosilicate minerals like epidote, actinolite, chlorite, quartz, sericite and sulfide mineralization. In addition to Fe, Si and Mg, substantial amounts of Cu, along with volatile components such as H2S and CO2 were added to the skarn system. Skarn mineralogy and geochemistry of the igneous rocks indicate an island arc or subduction-related origin of the Fe-Cu skarn deposit.

  2. Geological and Geochemical Characteristics of Skarn Type Lead-Zinc Deposit in Baoshan Block, Yunnan Province

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    Yao, Xue; Wang, Peng

    2017-11-01

    Baoshan block is an important Pb-Zn-Fe-Cu polymetallic ore-concentration area which is located in southern of the Sanjiang metallogenic belt in western Yunnan. The article is studying about the geological and geochemical characteristics of the skarn type lead-zinc deposit in Baoshan block. The skarn-type lead-zinc deposit Baoshan block is characterized by skarn and skarn marble, and the orebodies are layered, or bedded along the interlayer fault, which are significantly controlled by structure. The research about Stable isotope S, H and O indicates that the ore-forming fluids are mainly derived from magmatic water, partly mixed with parts of metamorphic water and atmospheric precipitation. The initial Sr isotopic Sr87/Sr86 ratio suggests that the ore-forming materials derived from deep concealed magmatic rock, age of Rb-Sr mineralization is similar to that of Yanshanian granite. In conclusion, the Yanshanian tectonic-magmatic-fluid coupling mineralization of Yanshan formation is the main reason for the skarn-type lead-zinc deposit in the Baoshan block.

  3. Geology and Characteristics of Pb-Zn-Cu-Ag Skarn Deposit at Ruwai, Lamandau Regency, Central Kalimantan

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    Arifudin Idrus

    2014-06-01

    Full Text Available DOI: 10.17014/ijog.v6i4.126This study is dealing with geology and characteristics of mineralogy, geochemistry, and physicochemical conditions of hydrothermal fluid responsible for the formation of skarn Pb-Zn-Cu-Ag deposit at Ruwai, Lamandau Regency, Central Kalimantan. The formation of Ruwai skarn is genetically associated with calcareous rocks consisting of limestone and siltstone (derived from marl? controlled by NNE-SSW-trending strike slip faults. It is localized along N 70° E-trending thrust fault, which also acts as the contact zone between sedimentary and volcanic rocks in the area. The Ruwai skarn is mineralogically characterized by prograde alteration comprising garnet (andradite and clino-pyroxene (wollastonite, and retrograde alteration composed of epidote, chlorite, calcite, and sericite. Ore mineralization is typified by sphalerite, galena, and chalcopyrite, formed at early retrograde stage. Galena is typically enriched in silver up to 0.45 wt % and bismuth of about 1 wt %. No Ag-sulphides are identified within the ore body. Geochemically, SiO is enriched and CaO is depleted in limestone, consistent with silicic alteration (quartz and calc-silicate and decarbonatization of the wallrock. The measured resources of the deposit are 2,297,185 tonnes at average grades of 14.98 % Zn, 6.44% Pb, 2.49 % Cu, and 370.87 g/t Ag. Ruwai skarn orebody was originated at moderate temperatures of 250 - 266 °C and low salinity of 0.3 - 0.5 wt.% NaCl eq. The late retrograde stage was formed at low temperature of 190 - 220 °C and low salinity of ~0.35 wt.% NaCl eq., which was influenced by meteoric water incursion at the late stage of the Ruwai Pb-Zn-Cu-Ag skarn formation.

  4. Geology, mineralization, and fluid inclusion study of the Kuru-Tegerek Au-Cu-Mo skarn deposit in the Middle Tien Shan, Kyrgyzstan

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    Soloviev, Serguei G.; Kryazhev, Sergey; Dvurechenskaya, Svetlana

    2018-02-01

    The Kuru-Tegerek Cu-Au-Mo deposit is situated in a system of Late Carboniferous subduction-related magmatic arcs of the Middle Tien Shan, which together constitute a metallogenic belt of Cu-Au-Mo (±W) porphyry, with local skarns, deposits. The deposit is related to magnetite-series gabbro-diorite to tonalite intrusion. It contains prograde magnesian and calcic skarns with abundant magnetite, associated with gabbro-diorite, and retrograde skarn with Cu mineralization, formed after intrusion of tonalite. Subsequent propylitic alteration introduced abundant chalcopyrite and pyrrhotite, and native Au culminating in zones overprinting magnetite and garnet skarn. Later quartz-muscovite-carbonate veins, formed after intrusion of late mafic quartz monzogabbro dikes, contain chalcopyrite, pyrite, arsenopyrite and other sulfides and sulfosalts, tellurides, and native Au. The earliest retrograde skarn garnet contains gaseous low-salinity (1.7-3.4 wt.% NaCl eq.) fluid inclusions homogenizing at 460-500 °C into vapor, indicating that the early fluid released from crystallizing magma was a low-density vapor. It was followed by more saline (4.0-5.0 wt.% NaCl eq.), high-temperature (400-440 °C) aqueous fluid, as fluid release from the magma progressed. Boiling of this fluid at temperatures of 420 to 370 °C and a pressure of 350-300 bar produced a low-salinity (0.6-1.2 wt.% NaCl eq.), essentially gaseous, and high-salinity (from 39 to 31 wt.% NaCl eq.) brine, with possible metal (including Cu) partitioning into both gaseous and aqueous-saline phases. Boiling was coeval with sulfide deposition in the retrograde skarn. The latest episode of the retrograde skarn stage included direct separation of saline ( 40-42 wt.% NaCl eq.) fluid from crystallizing magma. The separation of saline ( 40 to 14 wt.% NaCl eq.) fluids from a crystallizing magmatic melt continued during the propylitic stage, when fluid cooling from 370 to 320 °C, together with decreasing fO2, caused Cu and especially

  5. Magmatic-dominated fluid evolution in the Jurassic Nambija gold skarn deposits (southeastern Ecuador)

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    Vallance, Jean; Fontboté, Lluís; Chiaradia, Massimo; Markowski, Agnès; Schmidt, Susanne; Vennemann, Torsten

    2009-05-01

    and the compositional variability of chlorite, essentially controlled by host rock compositions. Gold was precipitated at this stage as a result of cooling and pH increase related to CO2 effervescence, which both result in destabilization of gold-bearing chloride complexes. Significant ingression of external fluids took place after gold deposition only, as recorded by δ18O values of 0.4‰ to 6.2‰ for fluids depositing quartz (below 350°C) in sulfide-rich barren veins. Low-temperature (bearing skarn deposits, not only the prograde stage but also the gold-precipitating retrograde stage is dominated by fluids of magmatic origin.

  6. Typomorphic Characteristics of Molybdenite from the Bystrinsky Cu-Au Porphyry-Skarn Deposit, Eastern Transbaikal Region, Russia

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    Kovalenker, V. A.; Trubkin, N. V.; Abramova, V. D.; Plotinskaya, O. Yu.; Kiseleva, G. D.; Borisovskii, S. E.; Yazykova, Yu. I.

    2018-01-01

    The paper presents pioneering data on the composition, texture, and crystal structure of molybdenite from various types of molybdenum mineralization at the Bystrinsky Cu-Au-Fe porphyry-skarn deposit in the eastern Transbaikal region, Russia. The data were obtained using electron microprobe analysis (EMPA), laser ablation-inductively coupled plasma mass spectrometry (LA-ICP-MS), and high-resolution transmission electron microscopy (HRTEM). Molybdenite found at the deposit in skarn, sulfide-poor quartz veins, and quartz-feldspar alteration markedly differs in the concentrations of trace elements determined by their species in the mineral, as well as in its structural features. Molybdenite-2H from skarn associated with phyllosilicates occurs as ultrafine crystals with uniform shape and texture; no dislocations or inclusions were found but amorphous silica was. The molybdenite composition is highly contrasting in the content and distribution of both structure-related (Re, W, and Se) and other (Mn, Co, Ni, Cu, Zn, As, Ag, Cd, Sb, Te, Ag, Pd, Au, Hg, Pb, and Bi) metals. In the sulfide-poor quartz veins, highly structurally heterogeneous (2H + 3R) molybdenite microcrystals with abundant defects (dislocations and volumetrically distributed inclusions) are associated with illite, goethite, and barite. Some single crystals are unique three-phase (2H + 3R polytypes + amorphous MoS2). The mineral has a low concentration of all trace elements, which are uniformly distributed. However, individual domains with uniquely high Pd, Te, Ni, Hg, and W concentrations caused by mineral inclusions are found in some grains. Molybdenite from quartz-feldspar alteration is characterized by low concentrations of all trace elements except for Re and Se, which enrich some domains of the grains. Our data indicate that the compositional and structural heterogeneity of molybdenite from the Bystrinsky deposit are its crucial features, which obviously correlate with the types of Mo mineralization.

  7. Geology, mineralization, and fluid inclusion characteristics of the Skrytoe reduced-type W skarn and stockwork deposit, Sikhote-Alin, Russia

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    Soloviev, Serguei G.; Kryazhev, Sergey G.

    2017-08-01

    The Skrytoe deposit (>145 Kt WO3, average grade 0.449% WO3) in the Sikhote-Alin orogenic system (Eastern Russia) is situated in a metallogenic belt of W, Sn-W, Au, and Au-W deposits formed in a late to post-collisional tectonic environment after cessation of active subduction. It is localized within a mineralized district of reduced-type skarn W and veined Au (±W) deposits and occurrences related to the Early Cretaceous ilmenite-series plutonic suite. The deposit incorporates large stockworks of scheelite-bearing veinlets related to propylitic (amphibole, chlorite, quartz) and phyllic (quartz, sericite, albite, apatite, and carbonate) hydrothermal alteration. The stockwork cuts flat-lying mafic volcanic rocks and limestone partially replaced by pyroxene skarn that host the major W orebodies. Scheelite is associated with pyrrhotite and/or arsenopyrite, with minor chalcopyrite and other sulfide minerals; the late phyllic stage assemblages hosts Bi and Au mineralization. The fluid evolution included low-salinity moderate-temperature, moderate-pressure (˜370-390 °C, ˜800 bars) methane-dominated carbonic-aqueous fluids that formed post-skarn propylitic alteration assemblages. Then, at the phyllic stage, there has been an evolution from methane-dominated, moderate-temperature (330-360 °C), low-salinity (<12.3 wt% NaCl equiv.) fluids forming the early quartz-sericite-albite-arsenopyrite assemblage, through lower temperature (290-330 °C) methane-dominated, low-salinity (˜9-10 wt% NaCl equiv.) fluids forming the intermediate quartz-sericite-albite-scheelite-pyrrhotite assemblage, to yet lower temperature (245-320 °C) CO2-dominated carbonic-aqueous low-salinity (˜1-7 wt% NaCl equiv.) fluids forming the late quartz-sericite-sulfide-Bi-Au assemblage. Recurrent fluid immiscibility (phase separation) and cooling probably affected W solubility and promoted scheelite deposition. The stable isotope data support a sedimentary source of carbon (δ13Cfluid = ˜-21 to -10

  8. LA-ICP-MS U-Th-Pb Dating and Trace Element Geochemistry of Allanite: Implications on the Different Skarn Metallogenesis between the Giant Beiya Au and Machangqing Cu-Mo-(Au Deposits in Yunnan, SW China

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    Yu Fu

    2017-12-01

    Full Text Available The giant Beiya Au skarn deposit and Machangqing porphyry Cu-Mo-(Au deposit are located in the middle part of the Jinshajiang–Ailaoshan alkaline porphyry metallogenic belt. The Beiya deposit is the largest Au skarn deposit in China, whilst the Machangqing deposit comprises a well-developed porphyry-skarn-epithermal Cu-Mo-(Au mineral system. In this paper, we present new allanite U-Th-Pb ages and trace element geochemical data from the two deposits and discuss their respective skarn metallogenesis. Based on the mineral assemblage, texture and Th/U ratio, the allanite from the Beiya and Machangqing deposits are likely hydrothermal rather than magmatic. Laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS allanite U-Th-Pb dating has yielded Th-Pb isochron ages of 33.4 ± 4.6 Ma (MSWD = 0.22 (Beiya and 35.4 ± 9.8 Ma (MSWD = 0.26 (Machangqing, representing the retrograde alteration and magnetite skarn mineralization age of the two deposits. The Beiya and Machangqing alkali porphyry-related mineralization are synchronous and genetically linked to the magmatic hydrothermal activities of the Himalayan orogenic event. Major and trace element compositions reveal that the Beiya allanite has higher Fe3+/(Fe3+ + Fe2+ ratios, U content and Th content than the Machangqing allanite, which indicate a higher oxygen fugacity and F content for the ore-forming fluids at Beiya. Such differences in the ore-forming fluids may have contributed to the different metallogenic scales and metal types in the Beiya and Machangqing deposit.

  9. A New Zincian Greenockite Occurrence in the Saishitang Cu Skarn Deposit, Qinghai Province, Northwest China

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    Jianping Liu

    2017-07-01

    Full Text Available Zn-Cd-S series minerals not only comprise industrial resources for Zn and Cd, but are also significant mineralogical indicators for hydrothermal ore-forming processes. Due to its unique formation conditions and rare occurrence, our understanding of the formation of zincian greenockite in natural systems is limited. Zincian greenockite was discovered during mineralogical studies in the Saishitang Cu skarn deposit, Qinghai Province, Northwest China. This provided an ideal opportunity to assess the occurrence and formation of zincian greenockite in skarn-type deposits. Ore minerals were observed using reflected-light microscopy, and the zincian greenockite was further analyzed using electron-probe microanalysis (EPMA and X-ray diffraction (XRD. The zincian greenockite occurs in the bornite–chalcopyrite ores and is composed of subhedral to anhedral grains approximately 50 × 150 μm2 to 200 × 300 μm2 in size, replaces the bornite, and is replaced by native silver. Two phases (I and II were identified based on back-scattered electron images, X-ray element-distributions maps, and EPMA data. The textural relationship indicated that Phase I was replaced by Phase II. Phase I contained high Zn (14.6 to 21.7 mol % ZnS and low Cd (72.4 to 82.2 mol % CdS, while Phase II contained low Zn (5.6 to 9.1 mol % ZnS and high Cd (85.4 to 89.9 mol % CdS. The zincian greenockite was formed at temperature of 300~270 °C during the transformation from a reducing environment to an oxidizing one in the late stage of the mineralization process in the Saishitang deposit.

  10. Study of REE behaviors, fluid inclusions, and O, S stable Isotopes in Zafar-abad iron skarn deposit, NW Divandarreh, Kordestan province

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    Mehrdad Barati

    2014-10-01

    Full Text Available Introduction The Zafar-abad iron ore deposit, situated in the NW part of Divandarreh (lat. 36°01'14" and long. 46°58'22". The ore body is located on the northern margin of the Sanandaj-Sirjan igneous metamorphic zone. The Zafar-abad Fe-skarn deposit is one of the important, medium- size mineral deposits in western Iran. REE patterns of skarn magnetite were among others studied in Skarn deposit by (Taylor, 1979 Hydrothermal alteration and fluid-rock interaction significantly affect total contents of REE and their patterns in fluids. Moreover, fractionation of REE by chemical complication, adsorption effects and redox reactions are characteristic processes determining REE behavior during crystallization. Stable isotope data for oxygen and sulfur have been widely used with great success to trace the origin and evolution history of paleo-hydrothermal fluids of meteoric, magmatic, and metamorphic. Materials and methods The present study investigates REE and stable Isotope geochemistry of magnetite and pyrite in Zafar-abad deposit and temperature of trapped fluid inclusions based on geothermometry analysis. In order to study the major, trace and REE compositions of Zafar-abad magnetite, twelve samples were collected from surface of ore exposures. The emphasis during sampling was on ores with primary textures. Discussion The Zafar-abad district is situated in Mesozoic and Cenozoic sedimentary, meta-sedimentary and meta-igneous rocks in Sanandaj-Sirjan igneous metamorphic zone. Sedimentary sequences dominantly composed of calcareous and conglomerate rocks. Various meta-sedimentary rocks are intercalated with the sedimentary rocks, and comprise biotite and muscovite-rich schist, calc-schist, calc-silicate rock. Several distinct ductile tectonic fabrics have been identified around the Zafar-abad deposit. The main ore body at Zafar-abad is in the form of a roughly horizontal, discordant, lens to tabular-shaped body plunging 10° NW, where it appears to

  11. The formation and trace elements of garnet in the skarn zone from the Xinqiao Cu-S-Fe-Au deposit, Tongling ore district, Anhui Province, Eastern China

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    Xiao, Xin; Zhou, Tao-fa; White, Noel C.; Zhang, Le-jun; Fan, Yu; Wang, Fang-yue; Chen, Xue-feng

    2018-03-01

    Xinqiao is a large copper-gold deposit and consists of two major mineralization types: stratabound and skarn. The skarn occurs along the contact between a quartz diorite intrusion and Carboniferous-Triassic limestone. Xinqiao has a strongly developed skarn zone, including endoskarn and exoskarn; the exoskarn is divided into proximal and distal exoskarn. We present systematic major, trace and rare earth element (REE) concentrations for garnets from the skarn zone, discuss the factors controlling the incorporation of trace elements into the garnets, and constrain the formation and evolution of the garnet from skarn zone in Xinqiao deposit. Grossular (Adr20-44Grs56-80) mostly occurs in endoskarn and has typical HREE-enriched and LREE-depleted patterns, with small Eu anomalies and low ∑REE. Garnets from the exoskarn show complex textures and chemical compositions. The composition of garnets range from Al-rich andradite (Adr63-81Grs19-47) to andradite (Adr67-98Grs2-33). Garnet in endoskarn has typical HREE-enriched and LREE-depleted patterns. Al-rich andradite in proximal skarn has small Eu anomalies and moderate ∑REE. Andradite from distal exoskarn shows strong positive Eu anomalies and has variable ∑REE. The U, Y, Fe and Al relationship with ∑REE shows that two mechanisms controlled incorporation of REE into the garnets: crystal chemistry (substitution and interstitial solid solution) mainly controlled in the endoskarn garnet (grossular) and the proximal exoskarn (Al-rich andradite), and fluid and rock chemistry (surface adsorption and occlusion) controlled REEs in the distal exoskarn. Furthermore, Al has a negative relationship with ∑REE indicating that REE3+ did not follow a coupled, YAG-type substitution into the garnets. Variations in textures and trace and rare earth elements of garnets suggest that the garnets in the endoskarn formed by slow crystal growth at low W/R ratios and near-neutral pH in a closed system during periods of diffusive metasomatism

  12. Usability of #betta#-spectrometric method to prospecting for copper-porphyric skarn and gold-quartz-sulfide deposits

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    Syromyatnikov, N.G.; Ivanova, Eh.I.; Karpukhin, V.G.; Trofimova, L.A.; Tolmachev, I.I.

    1982-01-01

    Possibility of the prospecting for non-radioactive element deposits by means of radioactive elements as indicators is studied. Radioactive elements (uranium, thorium and potassium) were determined by gamma spectroscopy. Radiometric methods of prospecting are effective and economical. Clark contents of radioelements in rocks were determined in situ by field gamma spectrometers. It is established that copper-porphyric deposits are regularly controlled from the surface by aureoles of increased uranium contents, which sizes reach 400x500 m and can be revealed by gamma spectroscopy during 1:25000 and more large-scale survey. Skarn-ore zones of deposits of different mineral types (copper, polymetallic, iron ore ones) are fixed on the surface by increased radioactivity; this fact can be used as search criterion. Gold-bearing quartz veins differ from barren lodes by a higher level of total radioactivity and high potassium content. Top walls of ore-bearing quartz veins are mainly enriched by radioelements

  13. Geology, mineralization, and fluid inclusion characteristics of the Kashkasu W-Mo-Cu skarn deposit associated with a high-potassic to shoshonitic igneous suite in Kyrgyzstan, Tien Shan: Toward a diversity of W mineralization in Central Asia

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    Soloviev, Serguei G.; Kryazhev, Sergey G.

    2018-03-01

    The Kashkasu deposit is part of the subduction-related Late Paleozoic (Late Carboniferous) metallogenic belt of Tien Shan. It is associated with a multiphase monzodiorite-monzonite-granodiorite-granite pluton of the magnetite-series high-K calc-alkaline to shoshonitic igneous suite. The deposit contains zones of W-Mo-Cu oxidized prograde and retrograde skarns, with abundant andraditic garnet, magnetite, locally scapolite and K-feldspar, as well as scheelite, chalcopyrite, and molybdenite. Skarns are overprinted by quartz-carbonate-sericite (phyllic alteration) zones with scheelite and sulfides. Prograde calcic skarn and initial retrograde skarns were formed from a high temperature (650 °C to 450-550 °C), high pressure (2000 bars to 600-900 bars) magmatic-hydrothermal low- to high-salinity aqueous chloride fluid. The gradual fluid evolution was interrupted by the intrusion of granodiorite and likely associated release of low-salinity (∼7-8 wt% NaCl equiv.) fluid. Ascent of this fluid to shallower levels and/or its cooling to 400-500 °C has resulted in phase separation into low-salinity (2.1-3.1 wt% NaCl equiv.) vapor and coexisting brine (35-40 wt% NaCl equiv.). The boiling was coincident with most intense scheelite deposition in retrograde skarn. Later retrograde skarn assemblages were formed from a gaseous, low- to moderate-salinity (3.4-8.1 wt% NaCl equiv.) fluid and then from high salinity (37-42 wt% NaCl equiv.) aqueous chloride fluids, the latter being enriched in Ca (17-20 wt% CaCl2) that could also affect scheelite deposition. Another cycle of fluid exsolution from crystallizing magma corresponded to quartz-carbonate-sericite-scheelite-sulfide (phyllic) alteration stage, with the early low-salinity (5.3-8.4 wt% NaCl-equiv.) fluid followed by later high-salinity (33.5-38.2 wt% NaCl-equiv.) fluid. The sulfur isotope data (δ34S = +5.1 to +9.0) suggest significant sulfur sourcing from sedimentary rocks enriched in seawater sulfate, possibly evaporites.

  14. Geochemistry of rare earth elements in the Baba Ali magnetite skarn deposit, western Iran – a key to determine conditions of mineralisation

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    Zamanian Hassan

    2016-03-01

    Full Text Available The Baba Ali skarn deposit, situated 39 km to the northwest of Hamadan (Iran, is the result of a syenitic pluton that intruded and metamorphosed the diorite host rock. Rare earth element (REE values in the quartz syenite and diorite range between 35.4 and 560 ppm. Although the distribution pattern of REEs is more and less flat and smooth, light REEs (LREEs in general show higher concentrations than heavy REEs (HREEs in different lithounits. The skarn zone reveals the highest REE-enriched pattern, while the ore zone shows the maximum depletion pattern. A comparison of the concentration variations of LREEs (La–Nd, middle REEs (MREEs; Sm–Ho and HREEs (Er–Lu of the ore zone samples to the other zones elucidates two important points for the distribution of REEs: 1 the distribution patterns of LREEs and MREEs show a distinct depletion in the ore zone while representing a great enrichment in the skarn facies neighbouring the ore body border and decreasing towards the altered diorite host rock; 2 HREEs show the same pattern, but in the exoskarn do not reveal any distinct increase as observed for LREEs and MREEs. The ratio of La/Y in the Baba Ali skarn ranges from 0.37 to 2.89. The ore zone has the highest La/Y ratio. In this regard the skarn zones exhibit two distinctive portions: 1 one that has La/Y >1 beingadjacent to the ore body and; 2 another one with La/Y < 1 neighbouring altered diorite. Accordingly, the Baba Ali profile, from the quartz syenite to the middle part of the exoskarn, demonstrates chiefly alkaline conditions of formation, with a gradual change to acidic towards the altered diorite host rocks. Utilising three parameters, Ce/Ce*, Eu/Eu* and (Pr/Ybn, in different minerals implies that the hydrothermal fluids responsible for epidote and garnet were mostly of magmatic origin and for magnetite, actinolite and phlogopite these were of magmatic origin with low REE concentration or meteoric water involved.

  15. Multiphase formation of the Obří důl polymetallic skarn deposit, West Sudetes, Bohemian Massif: geochemistry and Re–Os dating of sulfide mineralization

    Czech Academy of Sciences Publication Activity Database

    Veselovský, F.; Ackerman, Lukáš; Pašava, J.; Žák, Karel; Haluzová, Eva; Creaser, R. A.; Dobeš, P.; Erban, V.; Tásler, R.

    2018-01-01

    Roč. 53, č. 5 (2018), s. 665-682 ISSN 0026-4598 R&D Projects: GA ČR GA13-15390S Institutional support: RVO:67985831 Keywords : Bohemian Massif * polymetallic skarn deposit * West Sudetes * arsenopyrite * Re–Os geochronology Subject RIV: DB - Geology ; Mineralogy OBOR OECD: Geology Impact factor: 3.396, year: 2016

  16. Formation of the Vysoká-Zlatno Cu-Au skarn-porphyry deposit, Slovakia

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    Koděra, Peter; Lexa, Jaroslav; Fallick, Anthony E.

    2010-12-01

    The central zone of the Miocene Štiavnica stratovolcano hosts several occurrences of Cu-Au skarn-porphyry mineralisation, related to granodiorite/quartz-diorite porphyry dyke clusters and stocks. Vysoká-Zlatno is the largest deposit (13.4 Mt at 0.52% Cu), with mineralised Mg-Ca exo- and endoskarns, developed at the prevolcanic basement level. The alteration pattern includes an internal K- and Na-Ca silicate zone, surrounded by phyllic and argillic zones, laterally grading into a propylitic zone. Fluid inclusions in quartz veinlets in the internal zone contain mostly saline brines with 31-70 wt.% NaCl eq. and temperatures of liquid-vapour homogenization (Th) of 186-575°C, indicating fluid heterogenisation. Garnet contains inclusions of variable salinity with 1-31 wt.% NaCl eq. and Th of 320-360°C. Quartz-chalcopyrite veinlets host mostly low-salinity fluid inclusions with 0-3 wt.% NaCl eq. and Th of 323-364°C. Data from sphalerite from the margin of the system indicate mixing with dilute and cooler fluids. The isotopic composition of fluids in equilibrium with K-alteration and most skarn minerals (both prograde and retrograde) indicates predominantly a magmatic origin (δ18Ofluid 2.5-12.3‰) with a minor meteoric component. Corresponding low δDfluid values are probably related to isotopic fractionation during exsolution of the fluid from crystallising magma in an open system. The data suggest the general pattern of a distant source of magmatic fluids that ascended above a zone of hydraulic fracturing below the temperature of ductile-brittle transition. The magma chamber at ˜5-6 km depth exsolved single-phase fluids, whose properties were controlled by changing PT conditions along their fluid paths. During early stages, ascending fluids display liquid-vapour immiscibility, followed by physical separation of both phases. Low-salinity liquid associated with ore veinlets probably represents a single-phase magmatic fluid/magmatic vapour which contracted into

  17. Skarn and ore formation at Seriphos, Greece as a consequence of granodiorite intrusion

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    Salemink, J.

    1985-01-01

    On the island of Seriphos, Greece, the shallow intrusion of a granodiorite pluton into a series of previously regionally metamorphosed gneisses, marbles and marble-bearing schists produced a contact metamorphic aureole and extensive deposits of Ca-Fe-Mg skarns and Fe-ores. Structural and

  18. Single crystal structure analyses of scheelite-powellite CaW1-xMoxO4 solidsolutions and unique occurrence in Jisyakuyama skarn deposits

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    Yamashita, K.; Yoshiasa, A.; Miyazaki, H.; Tokuda, M.; Tobase, T.; Isobe, H.; Nishiyama, T.; Sugiyama, K.; Miyawaki, R.

    2017-12-01

    Jisyakuyama skarn deposit, Fukuchi, Fukuoka, Japan, shows a simple occurrenceformed by penetration of hot water into limestone cracks. A unique occurrence of scheelite-powellite CaW1-xMoxO4 minerals is observed in the skarn deposit. Many syntheticexperiments for scheelite-powellite solid solutions have been reported as research onfluorescent materials. In this system it is known that a complete continuous solid solution isformed even at room temperature. In this study, we have carried out the chemical analyses,crystal structural refinements and detail description of occurrence on scheelite-powelliteminerals. We have also attempted synthesis of single crystal of solid solution in a widecomposition range. The chemical compositions were determined by JEOL scanningelectron microscope and EDS, INCA system. We have performed the crystal structurerefinements of the scheelite-powellite CaW1-xMoxO4 solid solutions (x=0.0-1.0) byRIGAKU single-crystal structure analysis system RAPID. The R and S values are around0.0s and 1.03. As the result of structural refinements of natural products and many solidsolutions, we confirm that most large natural single crystals have compositions at bothendmembers, and large solid solution crystals are rare. The lattice constants, interatomicdistances and other crystallographic parameters for the solid solution change uniquely withcomposition and it was confirmed as a continuous solid solution. Single crystals of scheeliteendmember + powellite endmember + solid solution with various compositions form anaggregate in the deposit (Figure 1). Crystal shapes of powellite and scheelite arehypidiomorphic and allotriomorphic, respectively. Many solid solution crystals areaccompanied by scheelite endmember and a compositional gap is observed betweenpowellite and solid-solution crystals. The presence of several penetration solutions withsignificantly different W and Mo contents may be assumed. This research can be expectedto lead to giving restrictive

  19. Petrology and Geochemistry of Shakh Sefid Granitoid and related skarn in the North of Rayen (southeastern of Kerman

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    Habib biabangard

    2017-11-01

    Full Text Available The Shakh Sefid Granitoid pluton and related Skarn are located 80 Km in the southeastern of Kerman and 20 Km north of Rayen. This area   is geologically located in the southeastern of the Lut block in the Central Iran. The Shakh Sefid Granitoid with Eocene-Oligocene age cuts the Cretaceous sedimentary rocks and led to the formation of Skarn. The granitoids are granite and granodiorite in composition composing of quartz, plagioclase, orthoclase, as primary minerals, biotite as minor and chlorite and sericite as secondary minerals. The sedimentary rocks are shale, sandstone, siltstone and limestone. Metamorphic rocks are marble and Skarns. The Skarn is calcic type. Garnet (grossular-andradite, tremolite and magnetite are the main minerals that are often accompanied with hematite, goethite and limonite. Pyrite, chalcopyrite and copper carbonate (malachite and azurite are the other minerals in Skarn. Geochemical studies show that the amount of major and minor elements of granitoid with increasing SiO2 content do not change due to the uniform mass, low dispersion of elements which result from heterogeneous textures and low alteration zone. Spider diagrams from minor elements normalized to Chondrite and primitive mantle show enrichment of all elements except for Ti, positive anomalies of Th, Pb and negative anomalies of Ti, P and Sr for the Sakh Sefid granitoids are probably due to crustal contamination. They are enriched in light rare earth elements (LREE between 10 to 100 times and heavy elements (HREE enrichment between 1 to 10 times compared to the reference (chondrite and regular pattern with approximately the same slope , the parallel trends indicate that the granitoid rocks share  a common source rock . The Shakh Sefid granitoid is I-type, metaluminous to peraluminous belonging to an active continental margin. Mineral and Mineralization in Kuh Shakh Sefid skarn is remarkably similar to iron skarn deposits. Minerals such as garnet and

  20. Mineralogy and skarnification processes at the Avan Cu-Fe Skarn, northeast of Kharvana, NW Iran

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    Mir Ali Asghar Mokhtari

    2017-02-01

    . Investigation of genesis, mineralogy and geochemistry of Fe-Cu skarn in Astamal area, NE Kharvana, Eastern Azarbaijan. MSc. Thesis, University of Tabriz, Tabriz, Iran, 185 pp. (in Persian with English abstract Calagari, A.A. and Hosseinzadeh, G., 2005. The mineralogy of copper-bearing skarn to the east of the Sungun-Chay River, East-Azarbaijan, Iran. Journal of Asian Earth Sciences, 28(4-6: 423-438. Karimzadeh Somarin, A. and Moayed, M., 2002. Granite and gabbro-diorite associated skarn deposits of NW Iran. Ore geology reviews, 20(3-4: 127-138. Mokhtari, M.A.A., 2008. Petrology, geochemistry and petrogenesis of Qaradagh batholith (east of Syahrood, Eastern Azarbaijan and related skarn with considering mineralization. Ph.D. Thesis, Tarbiat Modares University, Tehran, Iran, 347 pp. (in Persian with English abstract Mokhtari, M.A.A., 2012. The mineralogy and petrology of the Pahnavar Fe skarn, in the Eastern Azarbaijan, NW Iran. Central European Journal of Geosciences, 4(4: 578-591.

  1. Multiphase formation of the Obří důl polymetallic skarn deposit, West Sudetes, Bohemian Massif: geochemistry and Re-Os dating of sulfide mineralization

    Science.gov (United States)

    Veselovský, František; Ackerman, Lukáš; Pašava, Jan; Žák, Karel; Haluzová, Eva; Creaser, Robert A.; Dobeš, Petr; Erban, Vojtěch; Tásler, Radko

    2018-06-01

    The Obří důl Fe-Cu-As polymetallic sulfide skarn deposit is developed in a metamorphic series in the West Sudetes, Bohemian Massif. It consists of lenses of marble, calc-silicate rocks, and skarns. We studied the Gustav orebody, which is located few hundred meters away from the contact with a large, late-orogenic Variscan Krkonoše-Jizera Plutonic Complex (KJPC) emplaced into shallow crust. Mineralogical and fluid inclusion study evidence indicates that the main sulfide stage, dominated by pyrrhotite, arsenopyrite, and chalcopyrite originated from aqueous hydrothermal fluids with salinity up to 8 wt% NaCl eq. with minimum homogenization temperatures ranging from 324 to 358 °C. These fluids mainly replaced carbonate-rich lithologies. Carbon, oxygen, and strontium isotope data in Ca-rich rocks imply total overprinting by channelized metasomatic fluid flow, which is most probably related to the intrusion of the KJPC, whereas δ34S values of sulfides argue for a magmatic source of sulfur. The Re-Os age of arsenopyrite overlaps published age data for the KJPC and suggests synchronous formation of the main sulfide mineralization and pluton emplacement.

  2. Preliminary Map of Landslide Deposits in the Mesa Verde National Park Area, Colorado

    Science.gov (United States)

    Carrara, Paul E.

    2009-01-01

    This report presents a preliminary map of landslide deposits in the Mesa Verde National Park area (see map sheet) at a compilation scale of 1:50,000. Landslide is a general term for landforms produced by a wide variety of gravity-driven mass movements, including various types of flows, slides, topples and falls, and combinations thereof produced by the slow to rapid downslope transport of surficial materials or bedrock. The map depicts more than 200 landslides ranging in size from small (0.01 square miles) earthflows and rock slumps to large (greater than 0.50 square miles) translational slides and complex landslides (Varnes, 1978). This map has been prepared to provide a regional overview of the distribution of landslide deposits in the Mesa Verde area, and as such constitutes an inventory of landslides in the area. The map is suitable for regional planning to identify broad areas where landslide deposits and processes are concentrated. It should not be used as a substitute for detailed site investigations. Specific areas thought to be subject to landslide hazards should be carefully studied before development. Many of the landslides depicted on this map are probably stable as they date to the Pleistocene (approximately 1.8-0.011 Ma) and hence formed under a different climate regime. However, the recognition of these landslides is important because natural and human-induced factors can alter stability. Reduction of lateral support (by excavations or roadcuts), removal of vegetation (by fire or development), or an increase in pore pressure (by heavy rains) may result in the reactivation of landslides or parts of landslides.

  3. Estimation of Groundwater Recharge at Pahute Mesa using the Chloride Mass-Balance Method

    Energy Technology Data Exchange (ETDEWEB)

    Cooper, Clay A [DRI; Hershey, Ronald L [DRI; Healey, John M [DRI; Lyles, Brad F [DRI

    2013-07-01

    Groundwater recharge on Pahute Mesa was estimated using the chloride mass-balance (CMB) method. This method relies on the conservative properties of chloride to trace its movement from the atmosphere as dry- and wet-deposition through the soil zone and ultimately to the saturated zone. Typically, the CMB method assumes no mixing of groundwater with different chloride concentrations; however, because groundwater is thought to flow into Pahute Mesa from valleys north of Pahute Mesa, groundwater flow rates (i.e., underflow) and chloride concentrations from Kawich Valley and Gold Flat were carefully considered. Precipitation was measured with bulk and tipping-bucket precipitation gauges installed for this study at six sites on Pahute Mesa. These data, along with historical precipitation amounts from gauges on Pahute Mesa and estimates from the PRISM model, were evaluated to estimate mean annual precipitation. Chloride deposition from the atmosphere was estimated by analyzing quarterly samples of wet- and dry-deposition for chloride in the bulk gauges and evaluating chloride wet-deposition amounts measured at other locations by the National Atmospheric Deposition Program. Mean chloride concentrations in groundwater were estimated using data from the UGTA Geochemistry Database, data from other reports, and data from samples collected from emplacement boreholes for this study. Calculations were conducted assuming both no underflow and underflow from Kawich Valley and Gold Flat. Model results estimate recharge to be 30 mm/yr with a standard deviation of 18 mm/yr on Pahute Mesa, for elevations >1800 m amsl. These estimates assume Pahute Mesa recharge mixes completely with underflow from Kawich Valley and Gold Flat. The model assumes that precipitation, chloride concentration in bulk deposition, underflow and its chloride concentration, have been constant over the length of time of recharge.

  4. Surficial Geologic Map of Mesa Verde National Park, Montezuma County, Colorado

    Science.gov (United States)

    Carrara, Paul E.

    2012-01-01

    Mesa Verde National Park in southwestern Colorado was established in 1906 to preserve and protect the artifacts and dwelling sites, including the famous cliff dwellings, of the Ancestral Puebloan people who lived in the area from about A.D. 550 to A.D. 1300. In 1978, the United Nations designated the park as a World Heritage Site. The geology of the park played a key role in the lives of these ancient people. For example, the numerous (approximately 600) cliff dwellings are closely associated with the Cliff House Sandstone of Late Cretaceous age, which weathers to form deep alcoves. In addition, the ancient people farmed the thick, red loess (wind-blown dust) deposits on the mesa tops, which because of its particle size distribution has good moisture retention properties. The soil in this loess cover and the seasonal rains allowed these people to grow their crops (corn, beans, and squash) on the broad mesa tops. Today, geology is still an important concern in the Mesa Verde area because the landscape is susceptible to various forms of mass movement (landslides, debris flows, rockfalls), swelling soils, and flash floods that affect the park's archeological sites and its infrastructure (roads, septic systems, utilities, and building sites). The map, which encompasses an area of about 100 mi2 (260 km2), includes all of Mesa Verde National Park, a small part of the Ute Mountain Indian Reservation that borders the park on its southern and western sides, and some Bureau of Land Management and privately owned land to the north and east. Surficial deposits depicted on the map include: artificial fills, alluvium of small ephemeral streams, alluvium deposited by the Mancos River, residual gravel on high mesas, a combination of alluvial and colluvial deposits, fan deposits, colluvial deposits derived from the Menefee Formation, colluvial deposits derived from the Mancos Shale, rockfall deposits, debris flow deposits, earthflow deposits, translational and rotational landslide

  5. Main characteristics and genesis of the Vale de Pães skarn (Cuba-Vidigueira, Ossa Morena Zone, Portugal

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    Salgueiro, R.

    2010-06-01

    Full Text Available The Vale de Pães (Cuba-Vidigueira mineralisation is composed of magnetite ± sulphides and hosted in a Pre-Variscan metamorphic sequence intruded by igneous rocks belonging to the Beja Igneous Complex. Its mineral and chemical features are compatible with a zoned Fe-skarn: Mg-rich (Fo + Di90, oxidised and Ca-rich (Grs + Di81-39, oxidised or relatively reduced. In the Fe-Mg skarn, magnetite deposition occurred along with the anhydrous mineral assemblage at ≈ 600 °C; sulphides precipitated from the retrograde stage onset (≤ 550 °C and during the hydrated and carbonate phases formation period (< 420 °C. In the Fe-Ca skarn, magnetite precipitated during the retrograde stage (< 550 °C together with the hydrated mineral association, and was followed by sulphides at ≈ 400°C. The mineralising process involved moderate-high salinity fluids and was controlled by variations in redox potential and pH.

    La mineralización del Vale de Pães (Cuba-Vidigueira, compuesta de magnetita ± sulfuros, se produce dentro de una secuencia metamórfica ante-Varisca intruida por el Complejo Ígneo de Beja (Beja Igneous Complex. Sus características químicas y mineralógicas son consistentes con un skarn de Fe zonificado: rico en Mg (Fo + Di≈90, oxidado y rico en Ca (Grs + Di81-39, oxidado o relativamente reducido. En el skarn de Fe-Mg, la deposición de magnetita acompaña a la paragénesis mineral anhidra (≈ 600 °C; la precipitación de sulfuros se produce desde el comienzo de la etapa retrógrada (≤ 550 °C y continuó durante la formación de fases hidratadas y carbonatadas (< 420 °C. En el skarn de Fe-Ca, la magnetita se genera en la fase de retroceso (< 550 °C, en relación con la asociación de minerales hidratados, seguido de sulfuro (≈ 400 °C. El proceso de mineralización de los fluidos de salinidad moderada-alta era controlado por los cambios en el potencial redox y el pH.

  6. Skarn-mineralized porphyry adakites in the Harlik arc at Kalatage, E. Tianshan (NW China): Slab melting in the Devonian-early Carboniferous in the southern Central Asian Orogenic Belt

    Science.gov (United States)

    Mao, Qigui; Yu, Mingjie; Xiao, Wenjiao; Windley, Brian F.; Li, Yuechen; Wei, Xiaofeng; Zhu, Jiangjian; Lü, Xiaoqiang

    2018-03-01

    The geodynamic control of mineralization in the accretionary evolution of the Central Asian Orogenic Belt (CAOB) has long been controversial. Here we report new field, geochemical and geochronological data on recently defined porphyry and skarn-type ore deposits (Devonian-Early Carboniferous) in the Kalatage area in the middle of the Harlik-Dananhu arc, Eastern Tianshan, NW China in the southern CAOB, with the aim of better understanding the accretionary tectonics and genesis of porphyry and skarn-type mineralization. The Yudai porphyry Cu-(Au) deposits and the Xierqu skarn Cu-Fe-(Au) deposits are closely associated with Middle Devonian adakitic diorite porphyries (382-390 Ma), which are calc-alkaline and characterized by high Na2O/K2O ratios and Sr contents (310-1020 ppm), strong depletion of HREE (e.g., Yb = 0.80-1.44 ppm) and Y (7.68-14.50 ppm), and all enriched in Rb, Sr, Ba, K and depleted in Nb and Ti. They are characterized by distinctive Eu positive anomalies, high Na2O contents and MORB-like Sr and Nd isotope signatures (high εNd(t) = +6.1 to +7.0 and low (87Sr/86Sr)i = 0.70412-0.70462). These adakites most likely formed by melting of a young/hot subducted oceanic slab, and adakites in general are important carriers of porphyry Cu ± (Au) deposits. Early Carboniferous adakites in the Tuwu area south of Kalatage are known to have similar features. Therefore, skarn-mineralized porphyry adakites get younger from north to south, suggesting southward migration of the Harlik-Dananhu arc from 390 Ma to 322 Ma. These data indicate that partial melting of hot (and/or young) oceanic crustal slabs were an important mechanism of accretionary crustal growth and mineralization in the southern CAOB.

  7. A synthesis of mineralization styles and geodynamic settings of the Paleozoic and Mesozoic metallic ore deposits in the Altay Mountains, NW China

    Science.gov (United States)

    Yang, Fuquan; Geng, Xinxia; Wang, Rui; Zhang, Zhixin; Guo, Xuji

    2018-06-01

    The Altay Mountains within the Xinjiang region of northwestern China hosts major metallic ore deposits. Here we review the geological characteristics, metallogenic features and tectonic settings of these deposits. The metallic ore deposits in the Altay Mountains occur mainly within four regions: North Altay, Central Altay, South Altay and Erqis. We recognize seven types of metallic ore deposits in the Altay Mountains: VMS, submarine volcanogenic iron, magmatic, skarn, pegmatite, hydrothermal vein (Cu-Zn, Fe) and orogenic gold. Among these types, the VMS, pegmatite, orogenic gold and skarn deposits are the most common. Most of the rare metal pegmatite deposits are distributed in Central Altay, with only a few in South Altay. The VMS, submarine volcanogenic type iron and skarn-type deposits are distributed in South Altay, whereas the orogenic-type gold deposits are distributed in the Erqis Fault belt. The hydrothermal vein-type deposits occur in the Erqis Fault belt and Chonghu'er Basin in South Altay. Magmatic-type deposits are mostly in the Erqis Fault belt and Central Altay. Based on isotopic age data, the VMS, submarine volcanogenic-type Fe and skarn-type Cu, Pb, Zn, Fe mineralization occurred during Early-Middle Devonian (∼410-377 Ma), orogenic-type Au, magmatic-type Cu-Ni, and a small number of skarn-type Fe, hydrothermal vein-type Cu-Zn, pegmatite-type rare-metal deposits in Early-Middle Permian (293-261 Ma), pegmatite-type rare-metal deposits, few skarn-type Fe deposit in Early-Middle Triassic (248-232 Ma), and dominantly represented by pegmatite-type rare-metal deposits in Late Triassic-Early Jurassic (223-180 Ma). The metallic ore deposits in the Altay Mountains formed in various tectonic settings, such as the Early-Middle Devonian continental arc and oceanic island arc, Early-Middle Permian post-collisional extensional setting, and Triassic-Early Jurassic intracontinental setting.

  8. Studies of petrography, metasomatic alteration, and genesis of Kamtal iron-copper skarn, northeast of Kharvana, East-Azarbaijan

    Directory of Open Access Journals (Sweden)

    Rasool Ferdowsi

    2012-04-01

    Full Text Available Kamtal skarn is located 15 km northeast of Kharvana, East-Azarbaijan. A quartz-monzonitic stock of Oligocene age intruded the upper Cretaceous sedimentary sequence (claystone, limestone, marl, and siltstone developing noticeable metamorphic (marble, hornfels and metasomatic (skarn alteration zones along the contact. Kamtal skarn is of calcic type and consists of both endoskarn and exoskarn zones. Exoskarn includes two zones of garnet skarn and epidote skarn. Skarnification processes are divided mainly in two major stages (1 prograde and (2 retrograde. During prograde stage, the emplacement of intrusive body caused isochemical metamorphism of the wall rocks and developed marble and hornfels units in enclosing rocks. Crystallization of intrusive body led to evolvement of hydrothermal fluid phase which infiltrated into enclosing rocks. Reaction of these fluids with the early-formed metamorphosed wall rocks brought about extensive progressive metasomatic alteration characterized by the formation of anhydrous calc-silicate minerals such as garnets and pyroxenes at a temperature range of 420-550°C and ¦O2=10-22-10-25. Retrograde stage was accompanied by some physicochemical changes (decrease in temperature to <420°C and increase in ¦S2 which caused the alteration of pre-existing anhydrous calc-silicates to hydrous calc-silicates (epidote, and tremolite-actinolite, silicates (quartz, chlorites, and other clay minerals, oxides (magnetite and hematite, sulfides (pyrite, chalcopyrite, and tetrahedrite, and carbonate (calcite. Comparison of Kamtal skarn with some other ones of corresponding type from Iran and other countries shows that Kamtal skarn well resembles to Anjerd and Pahnavar skarns in East-Azarbaijan.

  9. Age of the granitic magmatism and the W-Mo mineralization in skarns of the Seridó belt (NE Brazil) based on zircon U-Pb (SHRIMP) and molybdenite Re-Os dating

    Science.gov (United States)

    Hollanda, Maria Helena B. M. de; Souza Neto, João A.; Archanjo, Carlos J.; Stein, Holly; Maia, Ana C. S.

    2017-11-01

    Over five hundred W-Mo skarns have been reported in the Neoproterozoic Seridó belt in the northeastern Brazil. The origin of these mineralizations has been attributed to metasomatic reactions occuring after the infiltration of hydrothermal fluids that are mostly derived from the plutonic magmatic activity that ranged between approximately 600 and 525 Ma. Here we date molybdenite using N-TIMS on Re-Os analysis of three major scheelite deposits (Brejuí, Bonfim and Bodó) hosted in the skarn horizons of the metasedimentary sequence. Molybdenite is an integral part of the mineralizations that include scheelite in skarns and, in the Bonfim deposit, gold concentrate in late brittle faults. The Re-Os ages are 554 ± 2 Ma (Brejuí), 524 ± 2 Ma (Bonfim) and 510 ± 2 Ma (Bodó). The age of the Brejuí molybdenite, however, appears to be anomalous based on the local geology of the deposit, which is located next to the contact of a batholith dated ca. 575 Ma. In turn, the Bonfim molybdenite yields similar ages in replicated samples with variable high Re contents. New U-Pb SHRIMP ages of four biotite (leuco)granite plutons vary from 577 ± 5 Ma to 526 ± 8 Ma, which overlap with molybdenite crystallization. These results indicate a close connection between the W-Mo mineralizations and the plutonic activity that intruded the belt after the peak HT/LP metamorphism. The latest pulses of felsic magmatism, which were contemporaneous with the emplacement of Be-Ta-Nb-Li pegmatites, therefore constitute a potential guide in the Seridó belt for prospective W-Mo deposits.

  10. Petrology of skarns in the north and the southwest of Qazan (South Qamsar with emphasis on the mineral chemistry of garnet and pyroxene

    Directory of Open Access Journals (Sweden)

    Maria Chavideh

    2018-03-01

    Full Text Available The Oligo-Miocene Qazan granitoid body caused contact metamorphic of surrounding rocks and skarn formation in the wall limestone. The main intrusive rocks are essentially granite to diorite in composition. Two different types of skarn, exo and endoskarn have been developed. On the base of microprobe data, the northern skarn are characterized by zoning and the amounts of andradite and grossular changes oscillatory. While garnets from the southwestern skarn is predominantly andradite in composition. Using Fe/Ti vs. Al/ (Al+Fe+Mn diagram that were calculated based on the mole percent of the used elements, it is estimated that about less than 50 percent hydrothermal waters were involved for the northern skarn whereas it was over this amount for the southwestern skarn. This leds to difference in garnet composition. The composition of clinopyroxene in both skarns is the same (diopside. As a result, hydrothermal fluids have not had much influence on pyroxene genesis. With regards to the occurrence of mineral assemblage and the presence of wollastonite in the skarns under study, these rocks have evolved in temperature above 500 ° C and O2 fugacity in the range of 10-17 to 10-15.

  11. Kr-Ar and Rb-Sr dating and the genesis of tungsten at the Clea tungsten skarn property, Selwyn Mountains, Yukon Territory

    International Nuclear Information System (INIS)

    Godwin, C.I.; Armstrong, R.L.; Tompson, K.M.

    1980-01-01

    Tungsten skarn deposits on the Clea property in the Selwyn Mountains, Y.T., are related genetically to a quartz monzonite stock, about 500 metres in diameter at the surface. Lower Paleozoic sedimentary rocks are metamorphosed for a distance of 3 km from the stock. Tugnsten-bearing skarn mineralization within the altered sedimentary rocks is of two types: sulphide-rich pods and calc-silicate beds. The most significant sheelite concentration is in calc-silicate beds near or adjacent to the quartz monzonite stock. Discordant K-Ar and Rb-Sr isotopic dates indicate that the stock is probably of early Late Cretaceous age, 94 Ma or slightly older, and that it cooled slowly. High initial 87 Sr/ 86 Sr ratios and disequilibrium relationships between K-feldspar phenocrysts and groundmass minerals in the porphyritic phase of the granite rock, and between different granite rock specimens, indicate contamination of crystallizing magma by old sialic continental crust which extends westward under the Selwyn Basin. This study is significant to regional tungsten exploration. Granite rocks associated with tungsten deposits, in this part of the Canadian Cordillera at least, appear to have specific isotope characteristics that indicate they were generated at a specific time and in a particular way. (auth)

  12. Mesa with Apron

    Science.gov (United States)

    2006-01-01

    23 September 2006 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows a mesa and an impact grater just east of Phlegra Montes. The mesa is the eroded remnant of a once more extensive terrain. An apron of material surrounds the mesa. Location near: 38.5oN, 193.4oW Image width: 3 km (1.9 mi) Illumination from: lower left Season: Northern Spring

  13. Hydrothermal titanite from the Chengchao iron skarn deposit: temporal constraints on iron mineralization, and its potential as a reference material for titanite U-Pb dating

    Science.gov (United States)

    Hu, Hao; Li, Jian-Wei; McFarlane, Christopher R. M.

    2017-09-01

    Uranium-lead isotopes and trace elements of titanite from the Chengchao iron skarn deposit (Daye district, Eastern China), located along the contact zones between Triassic marine carbonates and an early Cretaceous intrusive complex consisting of granite and quartz diorite, were analyzed using laser ablation inductively coupled plasma mass spectrometry to provide temporal constraints on iron mineralization and to evaluate its potential as a reference material for titanite U-Pb geochronology. Titanite grains from mineralized endoskarn have simple growth zoning patterns, exhibit intergrowth with magnetite, diopside, K-feldspar, albite and actinolite, and typically contain abundant primary two-phase fluid inclusions. These paragenetic and textural features suggest that these titanite grains are of hydrothermal origin. Hydrothermal titanite is distinct from the magmatic variety from the ore-related granitic intrusion in that it contains unusually high concentrations of U (up to 2995 ppm), low levels of Th (12.5-453 ppm), and virtually no common Pb. The REE concentrations are much lower, as are the Th/U and Lu/Hf ratios. The hydrothermal titanite grains yield reproducible uncorrected U-Pb ages ranging from 129.7 ± 0.7 to 132.1 ± 2.7 Ma (2σ), with a weighted mean of 131.2 ± 0.2 Ma [mean standard weighted deviation (MSWD) = 1.7] that is interpreted as the timing of iron skarn mineralization. This age closely corresponds to the zircon U-Pb age of 130.9 ± 0.7 Ma (MSWD = 0.7) determined for the quartz diorite, and the U-Pb ages for zircon and titanite (130.1 ± 1.0 Ma and 131.3 ± 0.3 Ma) in the granite, confirming a close temporal and likely genetic relationship between granitic magmatism and iron mineralization. Different hydrothermal titanite grains have virtually identical uncorrected U-Pb ratios suggestive of negligible common Pb in the mineral. The homogeneous textures and U-Pb characteristics of Chengchao hydrothermal titanite suggest that the mineral might be a

  14. U-Pb, Re-Os and Ar-Ar dating of the Linghou polymetallic deposit, Southeastern China: Implications for metallogenesis of the Qingzhou-Hangzhou metallogenic belt

    Science.gov (United States)

    Tang, Yanwen; Xie, Yuling; Liu, Liang; Lan, Tingguan; Yang, Jianling; Sebastien, Meffre; Yin, Rongchao; Liang, Songsong; Zhou, Limin

    2017-04-01

    The Qingzhou-Hangzhou metallogenic belt (QHMB) in Southeastern China has gained increasingly attention in recent years. However, due to the lack of reliable ages on intrusions and associated deposits in this belt, the tectonic setting and metallogenesis of the QHMB have not been well understood. The Linghou polymetallic deposit in northwestern Zhejiang Province is one of the typical deposits of the QHMB. According to the field relationships, this deposit consists of the early Cu-Au-Ag and the late Pb-Zn-Cu mineralization stages. Molybdenite samples with a mineral assemblage of molybdenite-chalcopyrite-pyrite ± quartz are collected from the copper mining tunnel near the Cu-Au-Ag ore bodies. Six molybdenite samples give the Re-Os model ages varying from 160.3 to 164.1 Ma and yield a mean age of 162.2 ± 1.4 Ma for the Cu-Au-Ag mineralization. Hydrothermal muscovite gives a well-defined Ar-Ar isochron age of 160.2 ± 1.1 Ma for the Pb-Zn-Cu mineralization. Three phases of granodioritic porphyry have been distinguished in this deposit, and LA-ICP-MS zircon U-Pb dating shows that they have formed at 158.8 ± 2.4 Ma, 158.3 ± 1.9 Ma and 160.6 ± 2.1 Ma, comparable to the obtained ages of the Cu-Au-Ag and Pb-Zn-Cu mineralization. Therefore, these intrusive rocks have a close temporal and spatial relationship with the Cu-Au-Ag and Pb-Zn-Cu ore bodies. The presences of skarn minerals (e.g., garnet) and vein-type ores, together with the previous fluid inclusion and H-O-C-S-Pb isotopic data, clearly indicate that the Cu-Au-Ag and Pb-Zn-Cu mineralization are genetically related to these granodiorite porphyries. This conclusion excludes the possibility that this deposit is of ;SEDEX; type and formed in a sag basin of continental rifts setting as previously proposed. Instead, it is proposed that the Linghou polymetallic and other similar deposits in the QHMB, such as the 150-160 Ma Yongping porphyry-skarn Cu-Mo, Dongxiang porphyry? Cu, Shuikoushan/Kangjiawang skarn Pb

  15. Sulfur isotope study of the Velardeña skarn (Zn-Pb), Durango, Mexico

    Science.gov (United States)

    Jimenez, A.

    2012-04-01

    Sulfur isotope study of the Velardeña skarn (Zn-Pb), Durango, Mexico Abigail Jimenez-Franco1*, Pura Alfonso Abella2, Carles Canet3, Eduardo González-Partida4 1 Posgrado en Ciencias de la Tierra, Universidad Nacional Autónoma de México, Ciudad Universitaria, Delegación Coyoacán, 04510 México D.F., Mexico 2 Departament d'Enginyeria Minera i Recursos Naturals, Universitat Politècnica de Catalunya, Av de Les Bases de Manresa 61-73, 08242 Manresa. 3Instituto de Geofísica, Universidad Nacional Autónoma de México, Ciudad Universitaria, Delegación Coyoacán, 04510 México D.F., Mexico 4Centro de Geociencias, Universidad Nacional Autónoma de México, Campus Juriquilla, Boulevard Juriquilla 3001, 76230 Santiago de Querétaro, Qro., Mexico The Velardeña mining district is located in north-eastern part of the state of Durango, in northern of Mexico. The ore deposit is a lead-zinc, garnet-rich skarn developed at the contact between granite porphyry dikes (Eocene) and well-laminated limestones with interbedded chert (Albian-Cenomanian). A study of sulfur isotopes has been carried out in various sulfide minerals of the ores of Velardeña, in order to: (a) constrain the possible sources of sulfur and, therefore, better understand the sulfide mineralizing processes, and (b) to estimate the temperature of the ore-forming stage of the skarn. Sulfur isotope analyses were performed in 21 pure fractions of sulfide minerals of the ore mineralization (pyrite, chalcopyrite, sphalerite and galena). The mineral separation was performed using a series of sieves, and the purity of the samples was verified under a binocular microscope. Isotopic analyses were done on a Finnigan MAT Delta C flow elemental analyzer coupled to a TC-EA, according with the method of Giesemann et al. (1974). The δ34S values of the analyzed sulfides range mostly between -0.6 and +2.6 ‰ (relative to the CDT standard). These values are indicative of a magmatic source of sulfur. A single analysis falls

  16. Corrective Action Investigation Plan for Corrective Action Unit 99: Rainier Mesa/Shoshone Mountain, Nevada Test Site, Nevada

    International Nuclear Information System (INIS)

    McCord, John

    2004-01-01

    caldera as well as from more distant sources. This has resulted in a layered volcanic stratigraphy composed of thick deposits of welded and nonwelded ash-flow tuff and lava flows. These deposits are proximal to the source caldera and are interstratified with the more distal facies of fallout tephra and bedded reworked tuff from more distant sources. In each area, a similar volcanic sequence was deposited upon Paleozoic carbonate and siliciclastic rocks that are disrupted by various thrust faults, normal faults, and strike-slip faults. In both Rainier Mesa (km) to the southwest, and Tippipah Spring, 4 km to the north, and the tunnel complex is dry. Particle-tracking simulations performed during the value of information analysis (VOIA) (SNJV, 2004b) indicate that most of the regional groundwater that underlies the test locations at Rainier Mesa and Shoshone Mountain eventually follows similar and parallel paths and ultimately discharges in Death Valley and the Amargosa Desert. Particle-tracking simulations conducted for the regional groundwater flow and risk assessment indicated that contamination from Rainier Mesa and Shoshone Mountain were unlikely to leave the NTS during the 1,000-year period of interest (DOE/NV, 1997a). It is anticipated that CAU-scale modeling will modify these results somewhat, but it is not expected to radically alter the outcome of these previous particle-tracking simulations within the 1,000-year period of interest. The Rainier Mesa/Shoshone Mountain CAIP describes the corrective action investigation (CAI) to be conducted at the Rainier Mesa/Shoshone Mountain CAU to evaluate the extent of contamination in groundwater due to the underground nuclear testing. The CAI will be conducted by the UGTA Project, which is part of the NNSA/NSO Environmental Restoration Project (ERP). The purpose and scope of the CAI are presented in this section, followed by a summary of the entire document

  17. Geochemical Peculiarities of Galena and Sphalerite from Polymetallic Deposits of the Dal'negorskii Ore Region (Primorsky Krai, Russia)

    Science.gov (United States)

    Rogulina, L. I.; Moiseenko, V. G.; Ponomarchuk, V. A.

    2018-04-01

    New data on the composition of the major minerals from the skarn and vein polymetallic deposits of the Dal'negorskii ore region are reported. Analysis of galena and sphalerite was carried out by the X-ray fluorescent energy-dispersive method of synchrotron radiation for the first time. It is shown that the minor elements in major minerals of different deposits are typomorphic. Among these elements are Fe, Cu, Ni, Cd, Ag, Sn, and Sb, as well as In in sphalerite and Te in galena. The high concentrations of Ag, Cu, Te, Cd, and In in the extracted minerals indicate the complex character of mineralization. The compositional patterns of ore minerals characterize the sequence of mineral formation from the skarn to vein ores, and the sequence of deposits from the mesothermal to epithermal conditions. This provides geochemical evidence for the stage model of the formation of mineralization in the Dal'negorskii ore region.

  18. 36 CFR 7.39 - Mesa Verde National Park.

    Science.gov (United States)

    2010-07-01

    ... 36 Parks, Forests, and Public Property 1 2010-07-01 2010-07-01 false Mesa Verde National Park. 7... SPECIAL REGULATIONS, AREAS OF THE NATIONAL PARK SYSTEM § 7.39 Mesa Verde National Park. (a) Visiting of... the admission of commercial automobiles and buses to Mesa Verde National Park, contained in § 5.4 of...

  19. Mineralogy and geochemistry of Skarn Fe orebody and syenodioritic intrusive host rock in Zeber Kuh prospect area (SW Bardaskan, South Khorasan province

    Directory of Open Access Journals (Sweden)

    Hossein Narooie

    2017-11-01

    Full Text Available The Zeber Kuh prospect area is located southwest of Bardaskan, South Khorasan province, in the northeastern Iran. Lithologically, the area includes Rizu and Soltanieh Formations metamorphosed carbonate rocks, which were intruded by syenogranitic and syenodioritic intrusions. Field observations and laboratory studies such as structural controls of orebody, metasomatic replacement and formation of low temperature H2O-bearing minerals, and the occurrence of magnetite and pyrite associated with chlorite, epidote, calcite, and quartz indicate that  the iron mineralization is low temperature skarn-type. The source of Fe mineralization is probably a younger intrusive rock at depth. Hydrothermal ore fluid was ascended within fault zone and/or contact between the intrusive rock and the  carbonate unit and generated orebody. Iron grade ranges from 54 to 65 wt.% and sulfur value is > 3 wt.%. Magnetite chemistry and Ti, V, Al, Mn, Ni, and Cr contents are similar to skarn deposit. Biotite syenodiorite host rock has hypidiomorphic granular texture and it consists of plagioclase, K-feldspar, biotite, and apatite minerals. Chemically, this intrusive rock is K-series alkaline type, which was generated in within plate zone. This magma is characterized by strong enrichment in LREE, LILE (Rb, Cs, Ba, and K, HFSE (Nb, Zr, and Ti, and P elements. The primary magma is produced by low degree partial melting of garnet lherzolite from asthenospheric to boundary of asthenospheric-lithospheric mantle.

  20. Mineralogy, geochemistry and origin of Zafarabad iron deposit based on REE and trace elements of magnetite

    Directory of Open Access Journals (Sweden)

    Mehrdad Barati

    2013-10-01

    Full Text Available Zafarabad iron deposit is located northwest of Divandareh, in the northern margin of Sanandaj-Sirjan plutonic-metamorphic zone. The deposit is in lentoid to tubular shape, within a shear zone and occrrued in host rocks of calc-schist and limestone. Magnetite with massive, cataclastic and replacement textures are the main phases, while pyrite and other sulfide minerals are found. Major and trace elements are measured by ICP-MS and ICP-AES methods. Based on some ratios of trace elements in the ore samples and (Ti+V vs. Cal+Al+Mn and Ti+V vs. Ni/(Cr+Mn diagrams which are used for classification of iron deposit types, Zafarabad iron deposit fall in the range of skarn deposits. Spider diagrams show a steady decline from LREE to HREE elements with Eu (mean value of 0.06 ppm and Ce (mean value of 0.94 ppm negative anomalies. Comparing the distribution patterns of REE for the Zafarabad magnetites with those of various types of iron deposits shows that the REE pattern for Zafarabad is similar to these deposits. Analysis of calculated parameters for REE shows that the hydrothermal fluids responsible for mineralization are mainly of magmatic origin through fractionation and crystallization processes of a deep iron rich fluid phase and its emplacement within the carbonate rocks, forming iron skarn.

  1. Geology of the Horse Range Mesa quadrangle, Colorado

    Science.gov (United States)

    Cater, Fred W.; Bush, A.L.; Bell, Henry; Withington, C.F.

    1953-01-01

    The Horse Range Mesa quadrangle is one of eighteen 7 1/2-minute quadrangles covering the principal carnotite-producing area of southwestern Colorado. The geology of the quadrangles was mapped by the U.S. Geological Survey for the Atomic Energy Commission as part of a comprehensive study of carnotite deposits. The rocks exposed in the eighteen quadrangles consist of crystalline rocks of pre-Cambrian age and sedimentary rocks that range in age from late Paleozoic to Quaternary. Over much of the area the sedimentary rocks are flat lying, but in places the rocks are disrupted by high-angle faults, and northwest-trending folds. Conspicuous among the folds are large anticlines having cores of intrusive salt and gypsum. Most of the carnotite deposits are confined to the Salt Wash sandstone member of the Jurassic Morrison formation. Within this sandstone, most of the deposits are spottily distributed through an arcuate zone known as the "Uravan Mineral Belt". Individual deposits range in size from irregular masses containing only a few tons of ore to large, tabular masses containing many thousands of tons. The ore consists largely of sandstone selectively impregnated and in part replaced by uranium and vanadium minerals. Most of the deposits appear to be related to certain sedimentary strictures in sandstones of favorable composition.

  2. Calidad de las aceitunas de mesa.

    Directory of Open Access Journals (Sweden)

    Garrido Fernández, Antonio

    1999-06-01

    Full Text Available The paper comments the different regulations related to table olives at national or international scales. The Unified Qualitative standard Applying to Table Olives in International Trade and COI/Codex (International Olive Oil Council, IOC, and IOC/Codex Alimentarius, «Reglamentación Técnico Sanitaria para la elaboración, circulación y venta de aceitunas de mesa» (Spanish, «Normas de calidad para la exportación de aceitunas de mesa» (Spanish, and the United States Standards for Grades of Green and Canned Ripe Olives (USA are especially considered. The effects of the new regulations on Nutritional Labelling (mainly in USA, applications of the Analysis and Control of Critical Points (ACCP, and the problems derived from the application of the ISO 9000, or EN 29000, to this Sector are also discussed.

    El trabajo comenta las diferentes normas, tanto nacionales como internacionales, que regulan los aspectos de la calidad de las aceitunas de mesa. Se comentan especialmente la Norma Cualitativa Unificada Aplicable a Aceitunas de Mesa en el Comercio Internacional y las correspondientes COI/CODEX (Consejo Oleícola Internacional, COI, y COI/Codex Alimentarius, respectivamente, la Reglamentación Técnico Sanitaria para la elaboración, circulación, y venta de aceitunas de mesa (española, las Normas de calidad para la exportación de Aceitunas de Mesa (española, y las «United States Standards for Grades of Green and Canned Ripe Olives» (USA. Asimismo se analizan las implicaciones de las nuevas reglamentaciones sobre etiquetado nutricional (principalmente en el comercio con USA, la aplicación del Análisis de Riesgos y Control de Puntos Críticos (ARCPC, y la necesidad de adaptar el Sector al cumplimiento de las diversas normas de la serie ISO 9000 o su equivalente EN 29000.

  3. Corrective Action Investigation Plan for Corrective Action Unit 99: Rainier Mesa/Shoshone Mountain, Nevada Test Site, Nevada with Errata and ROTC 1, Rev. No. 0

    Energy Technology Data Exchange (ETDEWEB)

    McCord, John; Marutzky, Sam

    2004-12-01

    volcanic rocks that erupted from the caldera as well as from more distant sources. This has resulted in a layered volcanic stratigraphy composed of thick deposits of welded and nonwelded ash-flow tuff and lava flows. These deposits are proximal to the source caldera and are interstratified with the more distal facies of fallout tephra and bedded reworked tuff from more distant sources. In each area, a similar volcanic sequence was deposited upon Paleozoic carbonate and siliciclastic rocks that are disrupted by various thrust faults, normal faults, and strike-slip faults. In both Rainier Mesa (km) to the southwest, and Tippipah Spring, 4 km to the north, and the tunnel complex is dry. Particle-tracking simulations performed during the value of information analysis (VOIA) (SNJV, 2004b) indicate that most of the regional groundwater that underlies the test locations at Rainier Mesa and Shoshone Mountain eventually follows similar and parallel paths and ultimately discharges in Death Valley and the Amargosa Desert. Particle-tracking simulations conducted for the regional groundwater flow and risk assessment indicated that contamination from Rainier Mesa and Shoshone Mountain were unlikely to leave the NTS during the 1,000-year period of interest (DOE/NV, 1997a). It is anticipated that CAU-scale modeling will modify these results somewhat, but it is not expected to radically alter the outcome of these previous particle-tracking simulations within the 1,000-year period of interest. The Rainier Mesa/Shoshone Mountain CAIP describes the corrective action investigation (CAI) to be conducted at the Rainier Mesa/Shoshone Mountain CAU to evaluate the extent of contamination in groundwater due to the underground nuclear testing. The CAI will be conducted by the UGTA Project, which is part of the NNSA/NSO Environmental Restoration Project (ERP). The purpose and scope of the CAI are presented in this section, followed by a summary of the entire document.

  4. Mining on the Mesa

    Energy Technology Data Exchange (ETDEWEB)

    Sprouls, M.W.

    1994-10-01

    Peabody Western Coal Co. is the owner of Black Mesa and Kayenta coal opencast mines, both sited on Hopi and Navajo lands. 93% of the employees are native American, mostly Navajo. Kayenta is the larger and extracts coal with draglines. Sulphur content is high so the coal has to be analyzed and carefully blended before use. Black Mesa also uses draglines, here quality control is not as important as it is at Kayenta. Coal is transported to power stations using slurry pipelines. Both mines are heavily involved in land reclamation, leaving a landscape that makes better grazing than it did before mining. 2 figs.

  5. Geologic map of Kundelan ore deposits and prospects, Zabul Province, Afghanistan; modified from the 1971 original map compilations of K.I. Litvinenko and others

    Science.gov (United States)

    Tucker, Robert D.; Peters, Stephen G.; Stettner, Will R.; Masonic, Linda M.; Moran, Thomas W.

    2015-10-26

    This map and cross sections are redrafted modified versions of the Geological map of the Kundelan ore deposit area, scale 1:10,000 (graphical supplement no. 18) and the Geological map of the Kundelan deposits, scale 1:2,000 (graphical supplement no. 3) both contained in an unpublished Soviet report by Litvinenko and others (1971) (report no. 0540). The unpublished Soviet report was prepared in cooperation with the Ministry of Mines and Industries of the Royal Government of Afghanistan in Kabul during 1971. This redrafted map and cross sections illustrate the geology of the main Kundelan copper-gold skarn deposit, located within the Kundelan copper and gold area of interest (AOI), Zabul Province, Afghanistan. Areas of interest (AOIs) of non-fuel mineral resources within Afghanistan were first described and defined by Peters and others (2007) and later by the work of Peters and others (2011a). The location of the main Kundelan copper-gold skarn deposit (area of this map) and the Kundelan copper and gold AOI is shown on the index map provided on this map sheet.

  6. MESA, PÚLPITO E PALCO

    OpenAIRE

    Calvani, Carlos Eduardo

    2015-01-01

    O artigo aborda a relação entre arte e religião a partir da liturgia cristã. Na primeira parte, apresenta historicamente, três centros visuais dos espaços litúrgicos nos quais se desenvolve o culto cristão -mesa, púlpito e palco – destacando simbolismos e significados atribuídos a cada um desses centros. A mesa (ou altar) caracteriza as liturgias de matriz católica; a centralidade do púlpito é a marca visual das liturgias protestantes reformadas; o palco, por sua vez, emerge, principalmente n...

  7. Evolution of borate minerals from contact metamorphic to hydrothermal stages: Ludwigite-group minerals and szaibélyite from the Vysoká - Zlatno skarn, Slovakia

    Science.gov (United States)

    Bilohuščin, Vladimír; Uher, Pavel; Koděra, Peter; Milovská, Stanislava; Mikuš, Tomáš; Bačík, Peter

    2017-09-01

    Borate minerals of the ludwigite group (LGM) and szaibélyite in association with hydroxylclinohumite, clinochlore, a serpentine mineral, magnesian magnetite, spinel, magnesite, dolomite and sulphide minerals, occur in a magnesian exoskarn in the R-20 borehole located in the Vysoká - Zlatno Cu-Au porphyry-skarn deposit, located within the Štiavnica Neogene stratovolcano, Western Carpathians, central Slovakia. The skarn is developed along the contact of Miocene granodiorite to quartz-diorite porphyry and a Middle-Upper Triassic dolomite-shale-psammite-anhydrite sedimentary sequence. The boron minerals were investigated by electron probe micro-analyser (EPMA) and micro-Raman techniques. The source of boron could have been from the granodiorite/quartz diorite intrusion; however some supply of B from adjacent evaporite-bearing sediments is also possible. Based on textural and compositional data, the minerals originated during two stages. (1) An early high-temperature, contact-metamorphic and metasomatic stage comprises coarse-crystalline aggregate of LGM (types 1 to 3) in association with hydroxylclinohumite, magnetite, and rarely spinel inclusions in LGM. Compositional variations of LGM show a crystallization sequence from early azoproite [≤17 wt% TiO2; 0.40 atoms pre formula unit (apfu) Ti, which correspond to ≤79 mol% of the Mg2(Mg0.5Ti0.5)O2(BO3) end-member], Ti-Al-rich members of LGM, "aluminoludwigite "[≤14 wt% Al2O3; ≤0.53 apfu, ≤53 mol% of Mg2AlO2(BO3) end-member] and Al-rich ludwigite in the central zone of crystals, to Ti-Al-poor ludwigite in outer parts of crystals. (2) Minerals of the late retrograde serpentinization and hydrothermal stage form irregular veinlets and aggregates, including partial alteration of hydroxylclinohumite to the serpentine-group mineral and clinochlore, replacement of LGM by szaibélyite, formation of the latest generation of Fe-rich, Ti-Al poor ludwigite in veinlets (type 4), and precipitation of dolomite, magnesite and

  8. Nature, diversity of deposit types and metallogenic relations of South China

    Science.gov (United States)

    Zaw, K.; Peters, S.G.; Cromie, P.; Burrett, C.; Hou, Z.

    2007-01-01

    The South China Region is rich in mineral resources and has a wide diversity of deposit types. The region has undergone multiple tectonic and magmatic events and related metallogenic processes throughout the earth history. These tectonic and metallogenic processes were responsible for the formation of the diverse styles of base and precious metal deposits in South China making it one of the resource-rich regions in the world. During the Proterozoic, the South China Craton was characterised by rifting of continental margin before eruption of submarine volcanics and development of platform carbonate rocks, and the formation of VHMS, stratabound copper and MVT deposits. The Phanerozoic metallogeny of South China was related to opening and closing of the Tethyan Ocean involving multiple orogenies by subduction, back-arc rifting, arc-continent collision and post-collisional extension during the Indosinian (Triassic), Yanshanian (Jurassic to Cretaceous) and Himalayan (Tertiary) Orogenies. The Late Palaeozoic was a productive metallogenic period for South China resulting from break-up and rifting of Gondwana. Significant stratabound base and precious metal deposits were formed during the Devonian and Carboniferous (e.g., Fankou and Dabaoshan deposits). These Late Palaeozoic SEDEX-style deposits have been often overprinted by skarn systems associated with Yanshanian magmatism (e.g., Chengmenshan, Dongguashan and Qixiashan). A number of Late Palaeozoic to Early Mesozoic VHMS deposits also developed in the Sanjiang fold belt in the western part of South China (e.g., Laochang and Gacun). South China has significant sedimentary rock-hosted Carlin-like deposits, which occur in the Devonian- to Triassic-aged accretionary wedge or rift basins at the margin of the South China Craton. They are present in a region at the junction of Yunnan, Guizhou, and Guangxi Provinces called the 'Southern Golden Triangle', and are also present in NW Sichuan, Gansu and Shaanxi, in an area known as

  9. Origin of the pegmatite veins within the skarn body at Vevčice near Znojmo (Gfohl Unit, Moldanubian Zone)

    Czech Academy of Sciences Publication Activity Database

    Buriánek, D.; Houzar, S.; Krmíček, Lukáš; Šmerda, J.

    2017-01-01

    Roč. 62, č. 1 (2017), s. 1-23 ISSN 1802-6222 Institutional support: RVO:67985831 Keywords : diorite pegmatite * skarn * mineralogy * geochemistry * Moldanubian Zone * Bohemian Massif Subject RIV: DB - Geology ; Mineralogy OBOR OECD: Geology Impact factor: 0.609, year: 2016

  10. MESA. An ERL project for particle physics experiments

    Energy Technology Data Exchange (ETDEWEB)

    Hug, Florian [Institut fuer Kernphysik, Universitaet Mainz (Germany)

    2016-07-01

    The Mainz Energy-recovering Superconducting Accelerator (MESA) will be constructed at the Institut fuer Kernphysik of the Johannes Gutenberg University of Mainz. The accelerator is a low energy continuous wave (CW) recirculating electron linac for particle physics experiments. MESA will be operated in two different modes serving mainly two experiments: the first is the external beam (EB) mode, where the beam is dumped after being used with the external fixed target experiment P2, whose goal is the measurement of the weak mixing angle with highest accuracy. The required beam current for P2 is 150 μA with polarized electrons at 155 MeV. In the second operation mode MESA will be run as an energy recovery linac (ERL). In an ERL the energy of the electrons is recovered after their experimental use by decelerating them in the superconducting acceleration cavities. The experiment served in this mode is a (pseudo) internal fixed target experiment named MAGIX. It demands an unpolarized beam of 1 mA at 105 MeV. In a later construction stage of MESA the achievable beam current in ERL-mode shall be upgraded to 10 mA. Within this talk an overview of the MESA project will be given highlighting the challenges of operation with high density internal gas targets and the (*new*) physics applications.

  11. Magnetite as the indicator of ore genesis for the Huangshaping polymetallic deposit, southern Hunan Province, China

    Science.gov (United States)

    Ding, T.; Ma, D.; Lu, J.; Zhang, R.

    2017-12-01

    Huangshaping polymetallic deposit, located in southern Hunan Province, China, hosts abundant W-Mo-Pb-Zn mineralization which linked with the skarn system located between late Mesozoic high-K calc-alkaline to shoshonitic granitoids and the Carboniferous carbonate in this deposit. In this study, concentrations of trace and minor elements of the magnetites from different skarn stages are obtained by in situ LA-ICP-MS analysis, in order to further understand the polymetallic mineralization processes within this deposit. The generally high concentrations of spinel elements, including Mg, Al, Ti, Mn, V, Cr, Co, Ni, Ga, Ge, and Sn, in all magnetites from this deposit suggest that these elements are incorporated into magnetite lattice by substituting Fe3+ and/or Fe2+. However, the various concentrations of Na, Si, K, Ca, and W elements in magnetites, combining the abnormal time-resolved analytical signals of LA-ICP-MS analyses, suggest that these elements are significantly affected by the fluid inclusions in magnetites. Two groups of magnetites can be further distinguished based on their trace and minor elements concentrations: Group-1 magnetites, including those in medium grain garnets and calcite, have obvious lower Na, Si, K, Ca, Sn, W, but higher Mg, Al, Ti, V, Co, Ni, Zn concentrations compared with Group-2 magnetites, which including those in coarse grain garnets, tremolite, and bulk magnetite ores. This suggests that the hydrothermal fluids where Group-2 magnetites precipitated are evolved magmatic fluids which have undergone the crystal fractionation during the early skarn stages (eg. Garnet and tremolite), the high Na, Si, K, and Ca in the hydrothermal fluids probably result from the dissolution of the host rocks, such as limestone, sandstone, and evaporite horizons in this deposit. However, the Group-1 magnetites probably precipitated in the hydrothermal fluids with low salinity, which result the low Na, Si, K, and Ca in these magnitites. Furthermore, these

  12. Geochronology and geochemistry of the granitoids and ore - forming age in the Xiaoyao tungsten polymetallic skarn deposit in the Jiangnan Massif tungsten belt, China: Implications for their petrogenesis, geodynamic setting, and mineralization

    Science.gov (United States)

    Su, Qiangwei; Mao, Jingwen; Wu, Shenghua; Zhang, Zhaochong; Xu, Shengfa

    2018-01-01

    The Xiaoyao tungsten polymetallic skarn deposit in the eastern Jiangnan Massif of Yangtze Block is located at the contact between a granodiorite pluton and Sinian-Cambrian limestone. The intrusions in the tungsten-rich district comprise the Xiaoyao and other granodiorite plutons and granite porphyry dikes. The age determinations by LA-ICP-MS U-Pb dating of zircons indicate that the granodiorite formed at 149.4 ± 1.1 Ma, whereas the granite porphyry was emplaced at 133.2 ± 0.7 Ma. Re-Os dating of molybdenite from the skarn orebodies yielded a weighted average age of 148.7 ± 2.3 Ma (n = 5). These ages indicate that the tungsten mineralization is temporally related to the granodiorite. The granodiorites are metaluminous (A/CNK = 0.86-0.98) and in the high-K calc-alkaline series. They contain hornblende and have a negative correlation between P2O5 and SiO2, indicating that they are typical I-type intrusions. The granite porphyries exhibit high alkali contents (Na2O + K2O = 7.97-9.53%), elevated FeOT/(FeOT + MgO) ratios (0.83-0.94), high concentrations of Zr, Nb, Ce, and Y, and high Zr saturation temperatures (average of 812 °C); thus, they are geochemically similar to A-type intrusions. The initial 87Sr/86Sr and εNd(t) values range respectively from 0.7074 to 0.7083 and from - 7.9 to - 1.3 for the granodiorite, and from 0.7008 to 0.7083 and from - 6.3 to - 4.7 for the granite porphyry. In addition, two-stage Nd model ages (T2DM) of 1.0-1.6 Ga for the granodiorite and 1.3-1.4 Ga for the granite porphyry indicate that the Proterozoic crustal rocks of the Shangxi Group could have contributed to the Xiaoyao magmas. The rhenium contents of the molybdenite grains vary from 32 to 136 ppm, suggesting that the molybdenum was derived mainly from a mixture of mantle and crustal sources. Based on the new geochemical data and regional geological investigations, we propose that the Late Jurassic mineralization-related I-type granodiorite was derived from the Neoproterozoic

  13. Mineralogy, chemistry of magnetite and genesis of Korkora-1 iron deposit, east of Takab, NW Iran

    Directory of Open Access Journals (Sweden)

    Mohammad Maanijou

    2014-10-01

    Full Text Available Introduction There is an iron mining complex called Shahrak 60 km east of Takab town, NW Iran. The exploration in the Shahrak deposit (general name for all iron deposits of the area started in 1992 by Foolad Saba Noor Co. and continued in several periods until 2008. The Shahrak deposit comprising 10 ore deposits including Korkora-1, Korkora-2, Shahrak-1, Shahrak-2, Shahrak-3, Cheshmeh, Golezar, Sarab-1, Sarab-2, and Sarab-3 deposits Sheikhi, 1995 with total 60 million tons of proved ore reserves. The Fe grade ranges from 45 to 65% (average 50%. The ore reserves of these deposits vary and the largest one is Korkora-1 with 15 million tons of 55% Fe and 0.64% S. The Korkora-1 ore deposit is located in western Azarbaijan and Urumieh-Dokhtar volcanic zone, at the latitude of 36°21.8´, and longitude of 47°32´. Materials and methods Six thin-polished sections were made on magnetite, garnet, and amphibole for EPMA (Electron Probe Micro Analysis. EPMA was performed using a JEOL JXA-733 electron microprobe at the University of New Brunswick, Canada, with wavelength-dispersive spectrometers. Results and discussion Outcropped units of the area are calc-alkaline volcanics of rhyolite, andesite and dacite and carbonate rocks of Qom Formation in which intrusion of diorite to granodiorite and quartzdoirite caused contact metamorphism, alteration plus skarnization and formation of actinolite, talc, chlorite, phlogopite, quartz, calcite, epidote and marblization in the vicinity of the ore deposit. Iron mineralization formed at the contacts of andesite and dacite with carbonates in Oligo-Miocene. The study area consists of skarn, metamorphic rocks, and iron ore zones. The shape of the deposit is lentoid to horizontal with some alteration halos. The ore occurred as replacement, massive, disseminated, open-space filling and breccia. The ore minerals of the deposit include low Ti-magnetite (0.04 to 0.2 wt % Ti, minor apatite, and sulfide minerals such as pyrite

  14. Genesis of the Bangbule Pb-Zn-Cu polymetallic deposit in Tibet, western China: Evidence from zircon U-Pb geochronology and S-Pb isotopes

    Science.gov (United States)

    Kan, Tian; Zheng, Youye; Gao, Shunbao

    2016-04-01

    The Banbule Pb-Zn-Cu skarn deposit is located in the Longger-Gongbujiangda volcanic magma arc in the Gangdese-Nyainqentanglha Plate. It is the only lead-zinc polymetallic deposit discovered in the westernmost Nyainqentanglha metallogenic belt. The measured and indicated resources include 0.9 Mt of Pb+Zn (4.77% Pb and 4.74% Zn, respectively), 6499 t of Cu, and 178 t of Ag (18.75g/t Ag). The orebodies mainly occur as lenses, veins and irregular shapes in the contact zone between the quartz-porphyry and limestone of the Upper Permian Xiala Formation, or in the boundaries between limestone and sandstone. Pb-Zn-Cu mineralization in the Banbule deposit is closely associated with skarns. The ore minerals are dominated by galena, sphalerite, chalcopyrite, bornite, and magnetite, with subordinate pyrite, malachite, and azurite. The gangue minerals are mainly garnet, actinolite, diopside, quartz, and calcite. The ore-related quartz-porphyry displays LA-ICP-MS zircon U-Pb age of 77.31±0.74 Ma. The δ34S values of sulfides define a narrow range of -0.8 to 4.7‰ indicating a magmatic source for the ore-forming materials. Lead isotopic systematics yield 206Pb/204Pb of 18.698 to 18.752, 207Pb/204Pb of 15.696 to 15.760, and 208Pb/204Pb of 39.097 to 39.320. The data points are constrained around the growth curves of upper crust and orogenic belt according to the tectonic discrimination diagrams. The calculated Δβ - Δγ values plot within the magmatic field according to the discrimination diagram of Zhu et al. (1995). The S-Pb isotopic data suggest that Bangbule is a typical skarn deposit, and the Pb-Zn-Cu mineralization is genetically related to the quartz-porphyry in the mining district. The discovery of the Bangbule deposit indicates that there is metallogenic potential in the westernmost Nyainqentanglha belt, which is of great importance for the exploration work in this area.

  15. Alternative Fuels Data Center: Mesa Unified School District Reaps Economic

    Science.gov (United States)

    and Environmental Benefits with Propane Buses Mesa Unified School District Reaps Economic and School District Reaps Economic and Environmental Benefits with Propane Buses on Facebook Tweet about Alternative Fuels Data Center: Mesa Unified School District Reaps Economic and Environmental Benefits with

  16. MODULES FOR EXPERIMENTS IN STELLAR ASTROPHYSICS (MESA): PLANETS, OSCILLATIONS, ROTATION, AND MASSIVE STARS

    International Nuclear Information System (INIS)

    Paxton, Bill; Cantiello, Matteo; Bildsten, Lars; Arras, Phil; Brown, Edward F.; Dotter, Aaron; Mankovich, Christopher; Montgomery, M. H.; Stello, Dennis; Timmes, F. X.; Townsend, Richard

    2013-01-01

    We substantially update the capabilities of the open source software package Modules for Experiments in Stellar Astrophysics (MESA), and its one-dimensional stellar evolution module, MESA star. Improvements in MESA star's ability to model the evolution of giant planets now extends its applicability down to masses as low as one-tenth that of Jupiter. The dramatic improvement in asteroseismology enabled by the space-based Kepler and CoRoT missions motivates our full coupling of the ADIPLS adiabatic pulsation code with MESA star. This also motivates a numerical recasting of the Ledoux criterion that is more easily implemented when many nuclei are present at non-negligible abundances. This impacts the way in which MESA star calculates semi-convective and thermohaline mixing. We exhibit the evolution of 3-8 M ☉ stars through the end of core He burning, the onset of He thermal pulses, and arrival on the white dwarf cooling sequence. We implement diffusion of angular momentum and chemical abundances that enable calculations of rotating-star models, which we compare thoroughly with earlier work. We introduce a new treatment of radiation-dominated envelopes that allows the uninterrupted evolution of massive stars to core collapse. This enables the generation of new sets of supernovae, long gamma-ray burst, and pair-instability progenitor models. We substantially modify the way in which MESA star solves the fully coupled stellar structure and composition equations, and we show how this has improved the scaling of MESA's calculational speed on multi-core processors. Updates to the modules for equation of state, opacity, nuclear reaction rates, and atmospheric boundary conditions are also provided. We describe the MESA Software Development Kit that packages all the required components needed to form a unified, maintained, and well-validated build environment for MESA. We also highlight a few tools developed by the community for rapid visualization of MESA star results

  17. Nature and extent of lava-flow aquifers beneath Pahute Mesa, Nevada Test Site

    Energy Technology Data Exchange (ETDEWEB)

    Prothro, L.B.; Drellack, S.L. Jr.

    1997-09-01

    Work is currently underway within the Underground Test Area subproject of the US Department of Energy/Nevada Operations Office Environmental Restoration Program to develop corrective action plans in support of the overall corrective action strategy for the Nevada Test Site as established in the Federal Facility Agreement and Consent Order (FFACO, 1996). A closure plan is currently being developed for Pahute Mesa, which has been identified in the FFACO as consisting of the Western and Central Pahute Mesa Corrective Action Units. Part of this effort requires that hydrogeologic data be compiled for inclusion in a regional model that will be used to predict a contaminant boundary for these Corrective Action Units. Hydrogeologic maps have been prepared for use in the model to define the nature and extent of aquifers and confining units that might influence the flow of contaminated groundwater from underground nuclear tests conducted at Pahute Mesa. Much of the groundwater flow beneath Pahute Mesa occurs within lava-flow aquifers. An understanding of the distribution and hydraulic character of these important hydrogeologic units is necessary to accurately model groundwater flow beneath Pahute Mesa. This report summarizes the results of a study by Bechtel Nevada geologists to better define the hydrogeology of lava-flow aquifers at Pahute Mesa. The purpose of this study was twofold: (1) aid in the development of the hydrostratigraphic framework for Pahute Mesa, and (2) provide information on the distribution and hydraulic character of lava-flow aquifers beneath Pahute Mesa for more accurate computer modeling of the Western and Central Pahute Mesa Corrective Action Units.

  18. The Laramide Mesa formation and the Ojo de Agua caldera, southeast of the Cananea copper mining district, Sonora, Mexico

    Science.gov (United States)

    Cox, Dennis P.; Miller, Robert J.; Woodbourne, Keith L.

    2006-01-01

    The Mesa Formation extends from Cananea, Mexico, southeast to the Sonora River and is the main host rock of Laramide porphyry copper deposits in the Cananea District and at the Alacran porphyry prospect to the east. The Mesa consists of two members-a lower andesite and an upper dacite. The lowest part of the dacite member is a crystal tuff about 100 m thick. This tuff is the outfall of a caldera centered near the village of Ojo de Agua, dated by 40Ar/39Ar at 65.8 Ma ?0.4. The Ojo de Agua Caldera is about 9 km in diameter and is filled by a light gray biotite dacite tuff with abundant flattened pumice fragments. The volume of the caldera is estimated to be 24 km3.

  19. Hydraulic Property and Soil Textural Classification Measurements for Rainier Mesa, Nevada Test Site, Nevada

    Science.gov (United States)

    Ebel, Brian A.; Nimmo, John R.

    2010-01-01

    This report presents particle size analysis, field-saturated hydraulic conductivity measurements, and qualitative descriptions of surficial materials at selected locations at Rainier Mesa, Nevada. Measurements and sample collection were conducted in the Rainier Mesa area, including unconsolidated sediments on top of the mesa, an ephemeral wash channel near the mesa edge, and dry U12n tunnel pond sediments below the mesa. Particle size analysis used a combination of sieving and optical diffraction techniques. Field-saturated hydraulic conductivity measurements employed a single-ring infiltrometer with analytical formulas that correct for falling head and spreading outside the ring domain. These measurements may prove useful to current and future efforts at Rainier Mesa aimed at understanding infiltration and its effect on water fluxes and radionuclide transport in the unsaturated zone.

  20. Fabrication study of GaAs mesa diodes for X-ray detection

    OpenAIRE

    Ng, J.S.; Meng, X.; Lees, J.E.; Barnett, A.; Tan, C.H.

    2014-01-01

    A study of leakage currents using GaAs mesa p-i-n diodes for X-ray photon counting is presented. Different wet chemical etching solution and etch depth were used in the fabrication of these mesa diodes. Low and uniform leakage currents were achieved when the diode fabrication used (i) a combination of main etching solution and finishing etching solution for the etching, and (ii) partially etched mesas. The diodes fabricated using these methods showed well-defined X-ray peaks when illuminated ...

  1. Preliminary hydrogeological evaluation of geological units from the Mesa de los Santos, Santander

    International Nuclear Information System (INIS)

    Diaz, Eliana Jimena; Contreras, Nathalia Maria; Pinto, Jorge Eduardo; Velandia, Francisco; Morales, Carlos Julio; Hincapie, Gloria

    2009-01-01

    This paper present a preliminary hydrogeological evaluation of La Mesa de Los Santos' lithostratigraphic formations, based on the geological mapping, stratigraphy and inventory of water points. All this is supplemented with the analysis of primary porosity by means of the petrographic study and the secondary porosity related statistically with the quantity of fractures of each formation, as well as opening, interconnection and dip. It is made an approach to hydrogeological potential of the geologic outcropping formations in La Mesa de Los Santos, Department of Santander, from the stratigraphic and petrographic analysis and the structural features of these formations. The Upper Member of Los Santos Formation presents the highest potential because of rock's fracturing, continued by the Lower Member with low primary porosity and half fracturing. Silgara Formation, Granito de Pescadero, Jordan Formation and some sections of the sandy levels of the Rosablanca Formation presents a lowest potential due to its low porosity and low grade of fracturing. Low permeability is presented in the Middle Member of the Los Santos Formation, Paja and Tablazo formations, as well as in sectors of the fore mentioned formations and in the Quaternary deposits.

  2. MODULES FOR EXPERIMENTS IN STELLAR ASTROPHYSICS (MESA): PLANETS, OSCILLATIONS, ROTATION, AND MASSIVE STARS

    Energy Technology Data Exchange (ETDEWEB)

    Paxton, Bill; Cantiello, Matteo; Bildsten, Lars [Kavli Institute for Theoretical Physics, University of California, Santa Barbara, CA 93106 (United States); Arras, Phil [Department of Astronomy, University of Virginia, P.O. Box 400325, Charlottesville, VA 22904-4325 (United States); Brown, Edward F. [Department of Physics and Astronomy, National Superconducting Cyclotron Laboratory, and Joint Institute for Nuclear Astrophysics, Michigan State University, East Lansing, MI 48864 (United States); Dotter, Aaron [Research School of Astronomy and Astrophysics, The Australian National University, Weston, ACT 2611 (Australia); Mankovich, Christopher [Department of Physics, University of California, Santa Barbara, CA 93106 (United States); Montgomery, M. H. [Department of Astronomy and McDonald Observatory, University of Texas, Austin, TX 78712 (United States); Stello, Dennis [Sydney Institute for Astronomy (SIfA), School of Physics, University of Sydney, NSW 2006 (Australia); Timmes, F. X. [School of Earth and Space Exploration, Arizona State University, Tempe, AZ 85287 (United States); Townsend, Richard, E-mail: matteo@kitp.ucsb.edu [Department of Astronomy, University of Wisconsin-Madison, Madison, WI 53706 (United States)

    2013-09-15

    We substantially update the capabilities of the open source software package Modules for Experiments in Stellar Astrophysics (MESA), and its one-dimensional stellar evolution module, MESA star. Improvements in MESA star's ability to model the evolution of giant planets now extends its applicability down to masses as low as one-tenth that of Jupiter. The dramatic improvement in asteroseismology enabled by the space-based Kepler and CoRoT missions motivates our full coupling of the ADIPLS adiabatic pulsation code with MESA star. This also motivates a numerical recasting of the Ledoux criterion that is more easily implemented when many nuclei are present at non-negligible abundances. This impacts the way in which MESA star calculates semi-convective and thermohaline mixing. We exhibit the evolution of 3-8 M{sub Sun} stars through the end of core He burning, the onset of He thermal pulses, and arrival on the white dwarf cooling sequence. We implement diffusion of angular momentum and chemical abundances that enable calculations of rotating-star models, which we compare thoroughly with earlier work. We introduce a new treatment of radiation-dominated envelopes that allows the uninterrupted evolution of massive stars to core collapse. This enables the generation of new sets of supernovae, long gamma-ray burst, and pair-instability progenitor models. We substantially modify the way in which MESA star solves the fully coupled stellar structure and composition equations, and we show how this has improved the scaling of MESA's calculational speed on multi-core processors. Updates to the modules for equation of state, opacity, nuclear reaction rates, and atmospheric boundary conditions are also provided. We describe the MESA Software Development Kit that packages all the required components needed to form a unified, maintained, and well-validated build environment for MESA. We also highlight a few tools developed by the community for rapid visualization of MESA star

  3. Two mineralization events in the Baiyinnuoer Zn-Pb deposit in Inner Mongolia, China: Evidence from field observations, S-Pb isotopic compositions and U-Pb zircon ages

    Science.gov (United States)

    Jiang, Si-Hong; Chen, Chun-Liang; Bagas, Leon; Liu, Yuan; Han, Ning; Kang, Huan; Wang, Ze-Hai

    2017-08-01

    The Xing-Mong Orogenic Belt (XMOB) is located in the eastern part of the Central Asian Orogenic Belt (CAOB) and has experienced multiple tectonic events. The Baiyinnuoer Pb-Zn deposit may be a rare case that documents two periods of mineralization in the tectonically complex XMOB. There are two types of Pb-Zn mineralization in the deposit: (1) skarn-type ore, hosted by the skarn in the contact zone between marble and granodiorite and within the marble and (2) vein-type ore, hosted by crystal tuff and feldspar porphyry. This study revealed that the host rocks, mineral assemblages, mineralization occurrences, S-Pb isotopes, and ages between the two types of ore are notably different. Zircon U-Pb dating indicates that the granodiorite was emplaced in the Early Triassic (244 ± 1 to 242 ± 1 Ma), the crystal tuff was deposited in the Early Cretaceous (140 ± 1 to 136 ± 1 Ma), and the feldspar porphyry was intruded in the Early Cretaceous (138 ± 2 to 136 ± 2 Ma). The first skarn mineralization occurred at ∼240 Ma and the second vein-type Pb-Zn mineralization took place between 136 and 129 Ma. Thus the Triassic orebodies were overprinted by Early Cretaceous mineralization. The sphalerite and galena from the skarn mineralization have higher δ34S values (-4.7 to +0.3‰) than the sphalerite, galena and aresenopyrite from the vein-type mineralization (-7.5 to -4.2‰), indicating different sulfur sources or ore-forming processes for the two types of mineralization. The Pb isotopic compositions of the two types of ore are very similar, suggesting similar lead sources. Geochemistry and Nd-Pb-Hf isotopic systematics of the igneous rocks in the region show that the Triassic granodiorite was generated from hybridization of mafic and felsic magmas due to strong crust-mantle interaction under the collisional setting that resulted following the closure of the Paleo-Asian Ocean and the collision of North China and Siberian cratons at the end of the Permian; while the

  4. Modules for Experiments in Stellar Astrophysics (MESA): Convective Boundaries, Element Diffusion, and Massive Star Explosions

    Science.gov (United States)

    Paxton, Bill; Schwab, Josiah; Bauer, Evan B.; Bildsten, Lars; Blinnikov, Sergei; Duffell, Paul; Farmer, R.; Goldberg, Jared A.; Marchant, Pablo; Sorokina, Elena; Thoul, Anne; Townsend, Richard H. D.; Timmes, F. X.

    2018-02-01

    We update the capabilities of the software instrument Modules for Experiments in Stellar Astrophysics (MESA) and enhance its ease of use and availability. Our new approach to locating convective boundaries is consistent with the physics of convection, and yields reliable values of the convective-core mass during both hydrogen- and helium-burning phases. Stars with Meffects of Rayleigh-Taylor instabilities that, in combination with the coupling to a public version of the STELLA radiation transfer instrument, creates new avenues for exploring Type II supernova properties. These capabilities are exhibited with exploratory models of pair-instability supernovae, pulsational pair-instability supernovae, and the formation of stellar-mass black holes. The applicability of MESA is now widened by the capability to import multidimensional hydrodynamic models into MESA. We close by introducing software modules for handling floating point exceptions and stellar model optimization, as well as four new software tools - MESA-Web, MESA-Docker, pyMESA, and mesastar.org - to enhance MESA's education and research impact.

  5. Landscape Evolution Comparison between Sacra Mensa, Mars and the Grand Mesa, Colorado, USA

    Science.gov (United States)

    Chesnutt, J. M.; Wegmann, K. W.; Cole, R. D.; Byrne, P. K.

    2017-12-01

    The Grand Mesa in Colorado is one of the largest and highest flat-topped mountains on Earth, and as such provides a compelling analog for Mars' Sacra Mensa. Both basalt-capped landforms are morphologically similar, enabling a landscape evolution comparison between the two that considers key differences in locale, composition, and environmental conditions. Sacra Mensa is nearly 50 times the area of Grand Mesa and towers 3 km above the surrounding area. The 1,300 km2 Grand Mesa rises 2 km above Grand Valley, and is bracketed by the Colorado and Gunnison Rivers in much the same way as Sacra Mensa is bounded by braided channels of Kasei Valles. The sustained incision by the Gunnison and Colorado was a key erosive force in the creation of the Grand Mesa, whereas punctuated but voluminous Hesperian glacio-fluvial floods are thought to have carved the Sacra Mensa. The Grand Mesa is undergoing extensive mass wasting, ranging from deadly landslides like the 2014 West Salt Creek rock avalanche to hundreds of slower-moving retrogressive slump blocks calving off the Miocene basalt cap. The genesis and modification of both landforms includes volcanic and fluvial activity, albeit in an inverted sequence. The Grand Mesa basalt cap has preserved the landform during the incision around its sides, whereas Sacra Mensa was likely carved by floods, with those flood channels later modified by lava flows. Recent (2015-2017) LiDAR surveys revealed massive and possible ancient landslides in many stream valleys and extensive earthflows on all sides of the Grand Mesa. In the case of the Grand Mesa, the large landslides are mainly occurring in one stratigraphic unit. In comparison, the western half of Sacra Mensa contains substantial slumping accompanied by landslides and debris flows, whereas the eastern half has relatively few such phenomena. Here, we report on the first Mesa-Mensa landscape evolution analog study. The surficial and bedrock mapping and 14C dating of key features of the

  6. NPDES Permit for Mesa Verde National Park Wastewater Treatment Facility in Colorado

    Science.gov (United States)

    Under NPDES permit number CO-0034398, the United States Department of the Interior, National Park Service, Mesa Verde National Park is authorized to discharge from the Mesa Verde National Park wastewater treatment plant, in Montezuma County, Colo.

  7. The Technological Mineralogical Research of Molybdenum in Skarn-type Ore of Huangshaping Polymetallic Mining Area, Hunan, China

    Science.gov (United States)

    Liu, W. H.; Pan, J. Y.

    2017-10-01

    Huangshaping is one of the most important polymetallic deposits in the south of Hunan Province. Through field investigation, chemical analysis, observation under the optical microscope, energy spectrum analysis of the SEM and X-ray diffraction, the author made a technological mineralogical research of molybdenum on skarn-type ore, and the result shows that the ore containing molybdenum is mainly on the contact of the granite porphyry and the impure limestone in the lower carboniferous Shidengzi group. Besides molybdenum, the ore minerals contain scheelite, native bismuth, bismuthinite, magnetite and so on; and the gangue minerals are mainly andradite, fluorite and wollastonite. Part of the molybdenum exists in the scheelite in form of isomorphism, and there is an obvious negative correlation between MoO3 and WO3. The molybdenite granularity is mainly located in the 0.04~ 0.08mm area, which accounts for 29.5% of the total and is the finely disseminated ore. For samples of 70%, 90%, and 100% with the particle size of more than 200 meshes, the maximum recovery of the molybdenite are 75.15%, 86.45% and 91.25% respectively. So there will be a better use of molybdenum if we properly improve the grinded particle size of the comprehensive samples. As part of the molybdenum is distributed in the scheelite lattice, the actual recovery rate in this area may decline compared with the ideal value.

  8. Modeling unsaturated-zone flow at Rainier Mesa as a possible analog for a future Yucca Mountain

    International Nuclear Information System (INIS)

    Gauthier, J.H.

    1998-01-01

    Rainier Mesa is structurally similar to Yucca Mountain, and receives precipitation similar to the estimated long-term average for Yucca Mountain. Tunnels through the unsaturated zone at Rainier Mesa have encountered perched water and, after the perched water was drained, flow in fractures and faults. Although flow observations have been primarily qualitative, Rainier Mesa hydrology is a potential analog for Yucca Mountain hydrology in a wetter climate. In this paper, a groundwater flow model that has been used in the performance assessment of Yucca Mountain--the weeps model--is applied to Rainier Mesa. The intent is to gain insight in both Rainier Mesa and the weeps flow model

  9. MESA - A new approach to low cost scientific spacecraft

    Science.gov (United States)

    Keyes, G. W.; Case, C. M.

    1982-09-01

    Today, the greatest obstacle to science and exploration in space is its cost. The present investigation is concerned with approaches for reducing this cost. Trends in the scientific spacecraft market are examined, and a description is presented for the MESA space platform concept. The cost drivers are considered, taking into account planning, technical aspects, and business factors. It is pointed out that the primary function of the MESA concept is to provide a satellite system at the lowest possible price. In order to reach this goal an attempt is made to benefit from all of the considered cost drivers. It is to be tried to work with the customer early in the mission analysis stage in order to assist in finding the right compromise between mission cost and return. A three phase contractual arrangement is recommended for MESA platforms. The phases are related to mission feasibility, specification definition, and design and development. Modular kit design promotes flexibility at low cost.

  10. Bats of Mesa Verde National Park, Colorado: composition, reproduction, and roosting habits.

    Science.gov (United States)

    O'Shea, Thomas J.; Cryan, Paul M.; Snider, E. Apple; Valdez, Ernest W.; Ellison, Laura E.; Neubaum, Daniel J.

    2011-01-01

    We determined the bat fauna at Mesa Verde National Park (Mesa Verde) in 2006 and 2007, characterized bat elevational distribution and reproduction, and investigated roosting habits of selected species. We captured 1996 bats of 15 species in mist nets set over water during 120 nights of sampling and recorded echolocation calls of an additional species. The bat fauna at Mesa Verde included every species of bat known west of the Great Plains in Colorado, except the little brown bat (Myotis lucifugus). Some species showed skewed sex ratios, primarily due to a preponderance of males. Thirteen species of bats reproduced at Mesa Verde. Major differences in spring precipitation between the 2 years of our study were associated with differences in reproductive rates and, in some species, with numbers of juveniles captured. Reduced reproductive effort during spring drought will have a greater impact on bat populations with the forecasted increase in aridity in much of western North America by models of global climate change. We radiotracked 46 bats of 5 species to roosts and describe the first-known maternity colonies of spotted bats (Euderma maculatum) in Colorado. All 5 species that we tracked to diurnal roosts relied almost exclusively on rock crevices rather than trees or snags, despite the presence of mature forests at Mesa Verde and the use of trees for roosts in similar forests elsewhere by some of these species. Comparisons with past bat surveys at Mesa Verde and in surrounding areas suggest no dramatic evidence for effects of recent stand-replacing fires on the composition of the bat community.

  11. LOPEZ DE MESA Y LA MEDICINA

    Directory of Open Access Journals (Sweden)

    Humberto Roselli

    1985-04-01

    Full Text Available

    Hace apenas dos meses la Academia Nacional de Medicina y la Sociedad Colombiana de Historia de la Medicina iniciaban en este mismo recinto el homenaje del cuerpo médico colombiano a la memoria del Profesor Luis López de Mesa con motivo del primer centenario de su nacimiento, homenaje que ahora culmina con esta nueva sesión solenme conjunta.

    Fue la del Profesor López de Mesa una vida eminente en grado sumo, habiéndose destacado en todas las actividades que emprendiera, como se ha recordado profudamente en estos días. Autor de más de 20 obras que incluyeron novelas, tratados de sociología, de historia colombiana, ensayos filosóficos y reflexiones personales; hombre público que se destacó como Ministro de Educación, como parlamentario y diplomático, y luego como Ministro de Relaciones Exteriores, Rector de la Universidad Nacional; Académico y Presidente de la Academia Nacional de Medicina,Miembro de las de la Lengua, de Historia y de Ciencia Exactas, Físicas y Naturales; Presidente del Colegio Máximo de Academias; prácticamente no hubo campo de la inteligencia y de la cultura colombianas que el Profesor López de Mesa no hubiera tocado con éxito y en los cuales no hubiera dejado huellas de su pensamiento y de su trajín humanista. Se le considera como uno de los fundadores de la sociología en Colombia y un estilista difícil pero correcto y profundo. La trayectoria de su vida pública es aún ampliamente recordada en nuestro medio.

    En aquella ocasión hicimos un repaso de la carrera del Profesor López de Mesa como médico y psiquiatra y escudriñamos algunas de las circunstancias de su formación científica que habrían posteriormente de reflejarse en su obra como sociólogo y estadista.! En esta oportunidad resumimos aquellos y algunos otros detalles.

  12. Developing MESA : an accelerated reliability test

    NARCIS (Netherlands)

    Baskoro, G.; Rouvroye, J.L.; Bacher, W.; Brombacher, A.C.

    2003-01-01

    This paper describes the on-going research on an accelerated reliability test strategy called MESA (Multiple Environment Stress Analysis) intended to find in a fast and efficient manner (potential) reliability problems during the design phase of high volume consumer products. This test has shown

  13. MESA: Supporting Teaching and Learning about the Marine Environment--Primary Science Focus

    Science.gov (United States)

    Preston, Christine

    2010-01-01

    The Marine Education Society of Australasia (MESA) Inc. is a national organisation of marine educators that aims to bring together people interested in the study and enjoyment of coastal and marine environments. MESA representatives and members organise education and interpretation activities in support of schools and communities during a number…

  14. Modules for Experiments in Stellar Astrophysics (MESA): Giant Planets, Oscillations, Rotation, and Massive Stars

    OpenAIRE

    Paxton, Bill; Cantiello, Matteo; Arras, Phil; Bildsten, Lars; Brown, Edward F.; Dotter, Aaron; Mankovich, Christopher; Montgomery, M. H.; Stello, Dennis; Timmes, F. X.; Townsend, Richard

    2013-01-01

    We substantially update the capabilities of the open source software package Modules for Experiments in Stellar Astrophysics (MESA), and its one-dimensional stellar evolution module, MESA Star. Improvements in MESA Star's ability to model the evolution of giant planets now extends its applicability down to masses as low as one-tenth that of Jupiter. The dramatic improvement in asteroseismology enabled by the space-based Kepler and CoRoT missions motivates our full coupling of the ADIPLS adiab...

  15. Opportunities for parity violating electron scattering experiments at the planned MESA facility

    Science.gov (United States)

    Aulenbacher, Kurt

    2011-11-01

    We suggest to start an accelerator physics project called the Mainz Energy recovering Superconducting Accelerator (MESA) as an extension to our experimental facilities. MESA may allow to introduce an innovative internal target regime based on the ERL principle. A second mode of operation will be to use an external polarized electron beam for parity violating experiments.

  16. Annotated bibliography of the physical data of Rainier Mesa and Yucca Mountain

    International Nuclear Information System (INIS)

    Russell, C.E.

    1988-09-01

    Yucca Mountain, located on and adjacent to the Nevada Test Site (NTS) has been designated as the only site to undergo characterization to determine if it meets the criteria to become the Nation's first high-level nuclear waste repository. During this process, care must be taken to not compromise the site's integrity through excessive testing. In order to supplement the limited data to be gathered at Yucca Mountain, analog areas are to be considered. This annotated bibliography was compiled by the Desert Research Institute to help investigate ways in which Rainier Mesa could either be used as a supplemental repository test site or where existing Rainier Mesa data can be used either to support or refute test results from Yucca Mountain. Rainier Mesa, the location of numerous underground nuclear tests on the NTS, possesses some geologic characteristics similar to those of Yucca Mountain, which makes it a likely candidate for comparison. Almost 500 references regarding geology, hydrology, meteorology, biology, and archaeology were annotated and entered alpha-numerically into the bibliography. These references were categorized into 50 topics which are defined in Section 2 and presented in Section 3. Each reference is categorized as to whether it contains Yucca Mountain data, Rainier Mesa data, or both, and a final category consists of those reports that contain Rainier Mesa data that have already been applied to Yucca Mountain research. The annotated bibliography is presented in Section 4

  17. Metamorphic Rock-Hosted Orogenic Gold Deposit Type as a Source of Langkowala Placer Gold, Bombana, Southeast Sulawesi

    OpenAIRE

    Idrus, Arifudin; Nur, I; Warmada, I. W; Fadlin, Fadlin

    2011-01-01

    DOI: 10.17014/ijog.v6i1.114In 2008, placer gold was discovered in Langkowala area (Bombana Regency), Southeast Sulawesi, Indonesia, and more than 60,000 traditional gold miners in the early 2009 have been operating by digging vertical pits and panning active stream sediments. The grade of placer gold ranges from 50 to 140 g/t. Local geological framework indicates that the placer gold is not related to volcanic rock-related hydrothermal gold deposit, e.g. epithermal, skarn or porphyry. This pa...

  18. Advances in Understanding Air Pollution and Cardiovascular Diseases: The Multi-Ethnic Study of Atherosclerosis and Air Pollution (MESA Air)

    Science.gov (United States)

    Kaufman, Joel D.; Spalt, Elizabeth W.; Curl, Cynthia L.; Hajat, Anjum; Jones, Miranda R.; Kim, Sun-Young; Vedal, Sverre; Szpiro, Adam A.; Gassett, Amanda; Sheppard, Lianne; Daviglus, Martha L.; Adar, Sara D.

    2016-01-01

    The Multi-Ethnic Study of Atherosclerosis and Air Pollution (MESA Air) leveraged the platform of the MESA cohort into a prospective longitudinal study of relationships between air pollution and cardiovascular health. MESA Air researchers developed fine-scale, state-of-the-art air pollution exposure models for the MESA Air communities, creating individual exposure estimates for each participant. These models combine cohort-specific exposure monitoring, existing monitoring systems, and an extensive database of geographic and meteorological information. Together with extensive phenotyping in MESA—and adding participants and health measurements to the cohort—MESA Air investigated environmental exposures on a wide range of outcomes. Advances by the MESA Air team included not only a new approach to exposure modeling but also biostatistical advances in addressing exposure measurement error and temporal confounding. The MESA Air study advanced our understanding of the impact of air pollutants on cardiovascular disease and provided a research platform for advances in environmental epidemiology. PMID:27741981

  19. Availability, Sustainability, and Suitability of Ground Water, Rogers Mesa, Delta County, Colorado - Types of Analyses and Data for Use in Subdivision Water-Supply Reports

    Science.gov (United States)

    Watts, Kenneth R.

    2008-01-01

    Mesa consists of alluvial-fan deposits that overlie shale and, locally, sandstone. Maps of the base of the aquifer, the water table, and the saturated thickness of the aquifer were prepared from data from the well files of the Colorado Division of Water Resources. The base of the aquifer generally is topographically higher than the valleys of the North Fork Gunnison River and Leroux Creek, and direct hydraulic connection of the aquifer to North Fork Gunnison River and Leroux Creek is limited. The aquifer is recharged primarily by infiltration of surface water diverted for irrigation. Ground water discharges to seeps and springs and through slope deposits at the boundaries of the aquifer. Data from the well files also were used to estimate the specific capacity of wells and to estimate the transmissivity and hydraulic conductivity of the aquifer. A water budget was used to estimate recharge to and discharge from the aquifer. Although storage within the aquifer likely varies seasonally and from year to year, it was assumed that there were no long-term changes in ground-water storage. Estimated average annual recharge to and discharge from the aquifer during November 1998 through October 2006 were about 30,767 acre-feet per year. Although sufficient ground water is available on Rogers Mesa for additional domestic water supplies, conversion of irrigated land to residential land use likely would reduce recharge to the aquifer, affecting the sustainability of ground-water supplies on Rogers Mesa. Stream-depletion analyses indicate that the ground water in the aquifer likely would be considered tributary ground water and additional uses of ground water to supply new subdivisions likely would require implementation of augmentation plans. Although sufficient ground water is available on Rogers Mesa for additional domestic water supplies, conversion of irrigated land to residential land use likely would reduce recharge to the aquifer, affecting the sustainability

  20. Mesa Verde--A Year-Round High School. A Descriptive Report of 1980-81.

    Science.gov (United States)

    Housden, Terry; Holmes, Lynda

    Mesa Verde High School was constructed in 1974 and is the last high school built in the San Juan (California) Unified District. It serves students in grades 9 through 12 and has an open enrollment policy. Mesa Verde operates on a year-round schedule with students divided into three tracks. Basically, each track is in session for 9 weeks and then…

  1. Sestava pečenega piščančjega mesa različnih rej

    OpenAIRE

    Korenčan, Nina

    2017-01-01

    Namen diplomskega dela je bil ugotoviti, kako način reje piščancev (intenzivna (kontrola), ekološka reja (Eko) in z dodanim selenom, vezanim na organske spojine (Se)) vpliva na različne kakovostne parametre presnega mesa in mesa po pečenju, in sicer na masno razmerje meso, kosti in koža, na osnovno kemijsko sestavo, na izgubo mase med pečenjem ter na instrumentalne parametre in senzorične lastnosti kosov (prsi in bedra) piščančjega mesa. V poskusu smo analizirali devet trupov piščancev brez d...

  2. Canine neoplasia and exposure to uranium mill tailings in Mesa County, Colorado

    International Nuclear Information System (INIS)

    Reif, J.S.; Schweitzer, D.J.; Ferguson, S.W.; Benjamin, S.A.

    1983-01-01

    A canine cancer registry was established for Mesa County, Colorado in order to collect material for a case control analysis of exposure to uranium tailings. Between 1979 and 1981, 212 cases of canine cancer were confirmed histologically. Based on the address provided at the time of diagnosis, 33 dogs (15.6%) lived in a house with some exposure to uranium tailings. A control group, comprised of dogs with a histologic diagnosis other than cancer, was stratified according to hospital and matched with cases on a 1:1 basis. No significant differences were noted with respect to exposure to uranium tailings for total cancers or cancers of specific sites including lymph node, breast, liver, testicle and bone. The overall estimated relative risk was 0.70 (95% CI 0.04 to 1.16). Canine population estimates were derived for Mesa County in order to develop crude incidence rates for the major types and sites of cancer. Crude rates were compared with those published previously for Alameda County, California and Tulsa County, Oklahoma. Mesa County rates for total cancer incidence, connective tissue tumors and non melanoma skin cancer were higher than those reported for Alameda County. When compared with Tulsa County, Mesa County rates for total cancer, breast cancer, melanoma and mastocytoma were lower than expected while rates for osteosarcoma, hemangiosarcoma and fibrosarcoma significantly exceeded expected values

  3. Mesas de dinero: generalidades y experiencia en Colombia

    Directory of Open Access Journals (Sweden)

    Johnny Alvarez Jaramillo

    1989-04-01

    Full Text Available RESUMEN   Las necesidades de financiamiento de corto plazo, ha determinado el aguzamiento  de la imaginación para garantizar los recursos. Generalmente, las prácticas financieras en Colombia se extienden sin ningún control institucional; hasta que desafortunadamente, las prácticas desleales  o fraudulentas, llevan al estado a intervenir y reglamentar. Las llamadas MESAS DE DINERO, se han generalizado en nuestro medio en la medida en que proveen recursos financieros de corto plazo, difíciles de conseguir por los canales tradicionales. Los recientes escándalos del sector bursátil y anteriormente, la crisis bancaria, desaceleraron el crecimiento del mercado financiero extrainstitucional, pero no lo han acabado  del todo.El presente artículo, pretende informar brevemente sobre las experiencias de las llamadas  MESAS DE DINERO, su práctica y desarrollo.

  4. Live birth rates after MESA or TESE in men with obstructive azoospermia: is there a difference?

    NARCIS (Netherlands)

    van Wely, Madelon; Barbey, Natalie; Meissner, Andreas; Repping, Sjoerd; Silber, Sherman J.

    2015-01-01

    How do live birth rates compare after intracytoplasmic sperm injection (ICSI) for men with obstructive azoospermia when using sperm derived from testicular sperm extraction (TESE) versus microsurgical epididymal sperm aspiration (MESA)? Our study suggests that proximal epididymal sperm (from MESA)

  5. 76 FR 22075 - Divide Ranger District, Rio Grande National Forest; CO; Black Mesa Vegetation Management Project

    Science.gov (United States)

    2011-04-20

    ... Ranger District, Rio Grande National Forest; CO; Black Mesa Vegetation Management Project AGENCY: Forest... Web site http://www.fs.usda.gov/riogrande under ``Land & Resource Management'', then ``Projects'' on... need for the Black Mesa Vegetation Management Project is move toward achieving long-term desired...

  6. Mineral Deposit Data for Epigenetic Base- and Precious-metal and Uranium-thorium Deposits in South-central and Southwestern Montana and Southern and Central Idaho

    Science.gov (United States)

    Klein, T.L.

    2004-01-01

    Metal deposits spatially associated with the Cretaceous Boulder and Idaho batholiths of southwestern Montana and southern and central Idaho have been exploited since the early 1860s. Au was first discovered in placer deposits; exploitation of vein deposits in bedrock soon followed. In 1865, high-grade Ag vein deposits were discovered and remained economically important until the 1890s. Early high-grade deposits of Au, Ag and Pb were found in the weathered portions of the veins systems. As mining progressed to deeper levels, Ag and Pb grades diminished. Exploration for and development of these vein deposits in this area have continued until the present. A majority of these base- and precious-metal vein deposits are classified as polymetallic veins (PMV) and polymetallic carbonate-replacement (PMR) deposits in this compilation. Porphyry Cu and Mo, epithermal (Au, Ag, Hg and Sb), base- and precious-metal and W skarn, W vein, and U and Th vein deposits are also common in this area. The world-class Butte Cu porphyry and the Butte high-sulfidation Cu vein deposits are in this study area. PMV and PMR deposits are the most numerous in the region and constitute about 85% of the deposit records compiled. Several types of syngenetic/diagenetic sulfide mineral deposits in rocks of the Belt Supergroup or their equivalents are common in the region and they have been the source of a substantial metal production over the last century. These syngenetic deposits and their metamorphosed/structurally remobilized equivalents were not included in this database; therefore, deposits in the Idaho portion of the Coeur d'Alene district and the Idaho Cobalt belt, for example, have not been included because many of them are believed to be of this type.

  7. Hunter-gatherer adaptations and environmental change in the southern Great Basin: The evidence from Pahute and Rainier mesas

    Energy Technology Data Exchange (ETDEWEB)

    Pippin, L.C.

    1998-06-01

    This paper reviews the evidence for fluctuations in past environments in the southern Great Basin and examines how these changes may have affected the strategies followed by past hunter and gatherers in their utilization of the resources available on a highland in this region. The evidence used to reconstruct past environments for the region include botanical remains from packrat middens, pollen spectra from lake and spring deposits, faunal remains recovered from archaeological and geologic contexts, tree-ring indices from trees located in sensitive (tree-line) environments, and eolian, alluvial and fluvial sediments deposited in a variety of contexts. Interpretations of past hunter and gatherer adaptive strategies are based on a sample of 1,311 archaeological sites recorded during preconstruction surveys on Pahute and Rainier mesas in advance of the US Department of Energy`s nuclear weapons testing program. Projectile point chronologies and available tree-ring, radiocarbon, thermoluminescence and obsidian hydration dates were used to assign these archaeological sites to specific periods of use.

  8. Hydrologic Source Term Processes and Models for the Clearwater and Wineskin Tests, Rainier Mesa, Nevada National Security Site

    Energy Technology Data Exchange (ETDEWEB)

    Carle, Steven F. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2011-05-04

    This report describes the development, processes, and results of a hydrologic source term (HST) model for the CLEARWATER (U12q) and WINESKIN (U12r) tests located on Rainier Mesa, Nevada National Security Site, Nevada (Figure 1.1). Of the 61 underground tests (involving 62 unique detonations) conducted on Rainier Mesa (Area 12) between 1957 and 1992 (USDOE, 2015), the CLEARWATER and WINESKIN tests present many unique features that warrant a separate HST modeling effort from other Rainier Mesa tests.

  9. Effect of methyl salicylate (MeSA), an elicitor on growth, physiology and pathology of resistant and susceptible rice varieties.

    Science.gov (United States)

    Kalaivani, Kandaswamy; Kalaiselvi, Marimuthu Maruthi; Senthil-Nathan, Sengottayan

    2016-10-11

    Methyl salicylate (MeSA) is a volatile organic compound synthesized from salicylic acid (SA) a plant hormone that helps to fight against plant disease. Seed treatment with MeSA, is an encouraging method to the seed industry to produce more growth and yield. The aim of our study is to find out the growth, development and disease tolerance of rice seed treated with different concentrations of MeSA. Also the seed treatments were studied to determine whether they directly influenced seedling emergence and growth in rice (Oryza sativa L) cultivars 'IR 20, IR 50, IR 64, ASD 16, ASD 19 and ADT 46' under greenhouse condition. MeSA seed treatments at 25, 50, 75 and 100 mg/L significantly increased seedling emergence. Effects were stronger in IR 50, and IR 64 and the effects were dose dependent, although the relationship between dose and effect was not always linear. MeSA seed treated rice plant against bacterial blight were analyzed. Bacterial blight was more effectively controlled by the seed treated with 100 mg/L than others. These results suggest that seed treatment with MeSA alters plant physiology in ways that may be useful for crop production as well as protection.

  10. Molecular-beam epitaxy on shallow mesa gratings patterned on GaAs(311)A and (100) substrates

    NARCIS (Netherlands)

    Gong, Q.; Nötzel, R.; Schönherr, H.-P.; Ploog, K.H.

    2002-01-01

    We report on the morphology and properties of the surface formed by molecular-beam epitaxy on shallow mesa gratings on patterned GaAs(311)A and GaAs(100). On GaAs(311)A substrates, the corrugated surface formed after GaAs growth on shallow mesa gratings along [011] is composed of monolayer high

  11. Analysis of well ER-18-2 testing, Western Pahute Mesa - Oasis Valley FY 2000 testing program

    Energy Technology Data Exchange (ETDEWEB)

    None

    2002-09-30

    This report documents the analysis of the data collected for Well ER-18-2 during the Western Pahute Mesa - Oasis Valley (WPM-OV) well development and testing program that was conducted during fiscal year (FY) 2000. The data collection for that program is documented in Appendix A, Western Pahute Mesa - Oasis Valley, Well ER-18-2 Data Report for Development and Hydraulic Testing.

  12. Analysis of Well ER-EC-7 Testing, Western Pahute Mesa - Oasis Valley FY 2000 Testing Program

    Energy Technology Data Exchange (ETDEWEB)

    None

    2002-09-30

    This report documents the analysis of the data collected for Well ER-EC-7 during the Western Pahute Mesa - Oasis Valley (WPM-OV) well development and testing program that was conducted during fiscal year (FY) 2000. The data collection for that program was documented in Appendix A, Western Pahute Mesa - Oasis Valley, Well ER-EC-7 Data Report for Development and Hydraulic Testing.

  13. Analysis of Well ER-EC-8 testing, Western Pahute Mesa-Oasis Valley FY 2000 testing program

    Energy Technology Data Exchange (ETDEWEB)

    None

    2002-09-30

    This report documents the analysis of the data collected for Well ER-EC-8 during the Western Pahute Mesa - Oasis Valley (WPM-OV) well development and testing program that was conducted during fiscal year (FY) 2000. The data collection for that program is documented in Appendix A, Western Pahute Mesa-Oasis Valley, Well ER-EC-8 Data Report for development and Hydraulic Testing.

  14. Analysis of Well ER-EC-4 Testing, Western Pahute Mesa-Oasis Valley FY 2000 Testing Program

    Energy Technology Data Exchange (ETDEWEB)

    None

    2002-09-30

    This report documents the analysis of the data collected for Well ER-EC-4 during the Western Pahute Mesa-Oasis Valley (WPM-OV) well development and testing program that was conducted during fiscal year (FY) 2000. The data collection for that program is documented in Appendix A, Western Pahute Mesa - Oasis Valley, Well ER-EC-4 Data Report for Development and Hydraulic Testing.

  15. Analysis of Well ER-EC-5 Testing, Western Pahute Mesa-Oasis Valley FY 2000 Testing Program

    Energy Technology Data Exchange (ETDEWEB)

    None

    2002-09-30

    This report documents the analysis of the data collected for Well ER-EC-5 during the Western Pahute Mesa - Oasis Valley (WPM-OV) well development and testing program that was conducted during fiscal year (FY) 2000. The data collection for that program is documented in Appendix A, Western Pahute Mesa - Oasis Valley, Well ER-EC-5 Data Report for Development and Hydraulic Testing.

  16. Analysis of Well ER-EC-6 Testing, Western Pahute Mesa - Oasis Valley FY 2000 Testing Program

    Energy Technology Data Exchange (ETDEWEB)

    None

    2002-09-30

    This report documents the analysis of the data collected for Well ER-EC-6 during the Western Pahute Mesa-Oasis Valley (WPM-OV) well development and testing program that was conducted during fiscal year (FY) 2000. The data collection for that program is documented in Appendix A, Western Pahute Mesa-Oasis Valley, Well ER-EC-6 Data Report for Development and Hydraulic Testing.

  17. Analysis of Well ER-EC-1 Testing, Western Pahute Mesa-Oasis Valley FY 2000 Testing Program

    Energy Technology Data Exchange (ETDEWEB)

    None

    2002-09-30

    This report documents the analysis of the data collected for Well ER-EC-1 during the Western Pahute Mesa - Oasis Valley (WPM-OV) well development and testing program that was conducted during fiscal year (FY) 2000. The data collection for that program is documented in Appendix A, Western Pahute Mesa - Oasis Valley, Well ER-EC-1 Data Report for Development and Hydraulic Testing.

  18. Petrological and geochemical features of the early Paleozoic granitic gneisses and iron ores in the Tianhu iron deposit, Eastern Tianshan, NW China: Implications for ore genesis

    Science.gov (United States)

    Zheng, Jiahao; Mao, Jingwen; Yang, Fuquan; Chai, Fengmei; Shen, Ping

    2017-08-01

    This paper reports whole-rock geochemical, zircon U-Pb and Hf isotopic data for ore-hosted granitic gneisses, mineral compositions of oxides, and sulfur isotopic data for sulfides in iron ores from the Tianhu deposit, central part of the Eastern Tianshan. Our results can provide crucial constraints on the genesis of granitic gneisses and early Paleozoic tectonic setting of the Eastern Tianshan. LA-ICP-MS U-Pb dating on magmatic zircons yielded weighted mean 206Pb/238U ages of 463 to 438 Ma, interpreted as the crystallization ages of the granitic protoliths and the formation ages of the Tianhu Group. Zircon U-Pb age of ore-hosted granitic gneiss (ca. 459 Ma) can provide reliable constrains on upper limit for iron mineralization age in the Tianhu deposit. Geochemical characteristics suggest that the protoliths of the Tianhu granitic gneisses are metaluminous to weakly peraluminous high-K calc-alkaline granitic rocks, exhibiting typical subduction-related features such as strong enrichment in LREE and LILE and depletion in HFSE. Zircon Hf isotopic compositions show a positive trend from 463 to 438 Ma, indicating that 460 Ma magmas came from both ancient and juvenile sources, whereas 438 Ma magmas involved more juvenile material. Some early Paleozoic granitoids were recently identified in the Eastern Tianshan with the ages between ca. 475 and ca. 425 Ma. The formation of these early Paleozoic granitoids was in response to subduction processes, suggesting that subduction of Junggar Ocean probably began in the Early Ordovician and lasted until Late Silurian. Pyrite and pyrrhotite in iron ores have δ34SCDT values from + 4.6 to + 15.7‰, which are consistent with the marine source, but inconsistent with the magmatic source or those involved evaporites in skarn iron deposit. Geological, geochemical, and isotopic data suggest that the Tianhu iron ores were formed by volcano-sedimentary processes in a subduction environment during the early Paleozoic time, and Tianhu is a

  19. Evolving R Coronae Borealis Stars with MESA

    Science.gov (United States)

    Clayton, Geoffrey C.; Lauer, Amber; Chatzopoulos, Emmanouil; Frank, Juhan

    2018-01-01

    R Coronae Borealis (RCB) stars form a small class of cool, carbon-rich supergiants that have almost no hydrogen. They undergo extreme, irregular declines in brightness of up to 8 magnitudes due to the formation of thick clouds of carbon dust. Two scenarios have been proposed for the origin of an RCB star: the merger of a CO/He white dwarf (WD) binary and a final helium-shell flash. We are using a combination of 3D hydrodynamics codes and the 1D MESA (Modules for Experiments in Stellar Astrophysics) stellar evolution code including nucleosynthesis to construct post-merger spherical models based on realistic merger progenitor models and on our hydrodynamical simulations, and then following the evolution into the region of the HR diagram where RCB stars are located. We are investigating nucleosynthesis in the dynamically accreting material of CO/He WD mergers which may provide a suitable environment for significant production of 18O and the very low 16O/18O values observed.Our MESA modeling consists of two steps: first mimicking the WD merger event using two different techniques, (a) by choosing a very high mass accretion rate with appropriate abundances and (b) by applying "stellar engineering" to an initial CO WD model to account for the newly merged material by applying an entropy adjusting procedure. Second, we follow the post-merger evolution using a large nuclear reaction network including the effects of convective and rotational instabilities to the mixing of material in order to match the observed RCB abundances. MESA follows the evolution of the merger product as it expands and cools to become an RCB star. We then examine the surface abundances and compare them to the observed RCB abundances. We also investigate how long fusion continues in the He shell near the core and how this processed material is mixed up to the surface of the star. We then model the later evolution of RCB stars to determine their likely lifetimes and endpoints when they have returned to

  20. Completion Report for Well ER-20-4 Corrective Action Units 101 and 102: Central and Western Pahute Mesa

    Energy Technology Data Exchange (ETDEWEB)

    NSTec Environmental Management

    2011-04-30

    Well ER-20-4 was drilled for the U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office in support of the Nevada Environmental Restoration Project at the Nevada National Security Site, Nye County, Nevada. The well was drilled in August and September 2010 as part of the Pahute Mesa Phase II drilling program. The primary purpose of the well was to investigate the possibility of radionuclide transport from up-gradient underground nuclear tests conducted in central Pahute Mesa. This well also provided detailed hydrogeologic information in the Tertiary volcanic section that will help reduce uncertainties within the Pahute Mesa-Oasis Valley hydrostratigraphic framework model.

  1. Marine Ecosystems Analysis (MESA) Program, New York Bight Surficial Sediment Analyses

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Marine Ecosystems Analysis (MESA) Program, New York Bight Study was funded by NOAA and the Bureau of Land Management (BLM). The Atlas was a historical...

  2. Geophysical Investigations at Pahute Mesa, Nevada.

    Science.gov (United States)

    1987-08-12

    be azimuth dependent (Lynnes and Lay, 1984). The body wave magnitude anomalies observed by Alewine are plotted in Figure 1 along with the Bouguer ...of this type can be used to test the seismic Figure 1. The body wave magnitude anomaly is plotted on a map of the Bouguer gravity for Pahute Mesa...Nevada. 370 22’ 30" 370 7’ 300 116 30’ 1160 15’ 0 KILOMTERS 10 BOUGUER GRAVITY 2 mgal CONTOURS AMb o 0.2O 0.1- 0.2 0 0.0- 0.1 -0.1 - 0.0 X -0.2 - -0.1X

  3. Origins and exploration significance of replacement and vein-type alunite deposits in the Marysvale volcanic field, west central Utah.

    Science.gov (United States)

    Cunningham, C.G.; Rye, R.O.; Steven, T.A.; Mehnert, H.H.

    1984-01-01

    Alunite in the Marysvale volcanic field forms two (three are described) different types of deposits which contrast in appearance and conditions of origin: 1) Replacement deposits are generally fine-grained and formed by near-surface replacement of intermediate-composition volcanic rocks. The deposits form a bead necklace around a monzonite stock. Each deposit is zoned horizontally from alunitic cores to kaolinitic and propylitic envelopes and zoned vertically from pyrite/propylite upward through alunite/jarosite/hematite to a silica cap. Alunite does not extend below 100 m. Sulphur isotope ratios agree with derivation from underlying Mesozoic evaporites. 2) Natroalunite of 14-m.y. age crosscuts replacement-type alunite deposits. Its S-isotope ratios are comparable with those of pyrite in the volcanics. The Na may be from underlying Mesozoic halites. 3) Veins of coarse-grained alunite of 14-m.y. age filled extension fractures above a postulated stock. S-isotope ratios indicate a probable magmatic source. The contrasting properties of the Marysvale alunite deposits preclude any simple relation to ore deposits, but serve to refine interpretations based on other geological considerations. The replacement deposits are a logical near-surface result of skarn forming processes at depth around the monzonite stock. The vein- type deposits are a logical near-surface result of porphyry metallization in an underlying stock. -G.J.N.

  4. Analysis of Well ER-EC-2a Testing, Western Pahute Mesa-Oasis Valley FY 2000 Testing Program

    Energy Technology Data Exchange (ETDEWEB)

    None

    2002-09-30

    This report documents the analysis of the data collected for Well ER-EC-2a during the Western Pahute Mesa - Oasis Valley (WPM-OV) well development and testing program that was conducted during fiscal year (FY) 2000. The data collection for that program is documented in Appendix A, Western Pahute Mesa - Oasis Valley, Well ER-EC-2a Data Report for Development and Hydraulic Testing.

  5. Origin of elevated water levels encountered in Pahute Mesa emplacement boreholes: Preliminary investigations

    International Nuclear Information System (INIS)

    Brikowski, T.; Chapman, J.; Lyles, B.; Hokett, S.

    1993-11-01

    The presence of standing water well above the predicted water table in emplacement boreholes on Pahute Mesa has been a recurring phenomenon at the Nevada Test Site (NTS). If these levels represent naturally perched aquifers, they may indicate a radionuclide migration hazard. In any case, they can pose engineering problems in the performance of underground nuclear tests. The origin of these elevated waters is uncertain. Large volumes of water are introduced during emplacement drilling, providing ample source for artificially perched water, yet elevated water levels can remain constant for years, suggesting a natural origin instead. In an effort to address the issue of unexpected standing water in emplacement boreholes, three different sites were investigated in Area 19 on Pahute Mesa by Desert Research Institute (DRI) staff from 1990-93. These sites were U-19az, U-19ba, and U-19bh. As of this writing, U-19bh remains available for access; however, nuclear tests were conducted at the former two locations subsequent to this investigations. The experiments are discussed in chronological order. Taken together, the experiments indicate that standing water in Pahute Mesa emplacement holes originates from the drainage of small-volume naturally perched zones. In the final study, the fluids used during drilling of the bottom 100 m of emplacement borehole U-19bh were labeled with a chemical tracer. After hole completion, water level rose in the borehole, while tracer concentration decreased. In fact, total mass of tracer in the borehole remained constant, while water levels rose. After water levels stabilized in this hole, no change in tracer mass was observed over two years, indicating that no movement of water out of the borehole is taking place (as at U- 19ba). Continued labeling tests of standing water are recommended to confirm the conclusions made here, and to establish their validity throughout Pahute Mesa

  6. NPDES Permit for Mesa Verde National Park Water Treatment Plant in Colorado

    Science.gov (United States)

    Under NPDES permit number CO-0034462, the United States Department of the Interior, National Park Service is authorized to discharge from the Mesa Verde National Park water treatment plant, in Montezuma County, Colo.

  7. Iron and zinc partitioning between coexisting stannite and sphalerite: a possible indicator of temperature and sulfur fugacity

    Science.gov (United States)

    Shimizu, M.; Shikazono, N.

    1985-10-01

    Stannite and sphalerite coexisting with iron sulfides (pyrite and/or pyrrhotite) from Japanese ore deposits associated with tin mineralization were analyzed. Based on the iron and zinc partitioning between stannite and sphalerite, the formation temperature and sulfur fugacity for this mineral assemblage were estimated. A good correlation between stannite-sphalerite temperatures and filling temperatures of fluid inclusions and sulfur isotope temperatures was obtained. This good correlation suggests that the stannite-sphalerite pair is a useful indicator of temperature and sulfur fugacity. It is deduced that the formation temperatures are not different for skarn-type, polymetallic vein-type and Sn-W vein-type deposits, whereas the sulfur fugacities are different; sulfur fugacities increase from the skarn-type through the Sn-W vein-type to the polymetallic vein-type deposits.

  8. Fasting Glucose GWAS Candidate Region Analysis across Ethnic Groups in the Multi-Ethnic Study of Atherosclerosis (MESA)

    OpenAIRE

    Rasmussen-Torvik, L. J.; Guo, X.; Bowden, D. W.; Bertoni, A. G.; Sale, M. M.; Yao, J.; Bluemke, D. A.; Goodarzi, M. O.; Chen, Y. I.; Vaidya, D.; Raffel, L. J.; Papanicolaou, G.J.; Meigs, J. B.; Pankow, J. S.

    2012-01-01

    Genetic variants associated with fasting glucose in European ancestry populations are increasingly well understood. However, the nature of the associations between these SNPs and fasting glucose in other racial and ethnic groups is unclear. We sought to examine regions previously identified to be associated with fasting glucose in Caucasian GWAS across multiple ethnicities in the Multi-Ethnic Study of Atherosclerosis (MESA). Non-diabetic MESA participants with fasting glucose measured at the ...

  9. Four magnetite generations in the Precambrian Varena Iron Ore deposit, SE Lithuania, as a result of rock-fluid interactions

    Science.gov (United States)

    Skridlaite, Grazina; Prusinskiene, Sabina; Siliauskas, Laurynas

    2017-04-01

    Iron ores in Precambrian crystalline basement of the Varena area, SE Lithuania, were discovered during the detail geological-geophysical exploration in 1982-1992. They are covered with 210-500 m thick sediments. The Varena Iron Ore deposit (VIOD) may yield from 71 to 219.6 million tons of iron ore according to different economic evaluations (Marfin, 1996). They were assumed to be of metasomatic and hydrothermal origin, however several other hypotheses explaining the VIOZ origin, e.g. as a layered mafic or carbonatite intrusions were also suggested. Magnetites of the VIOD were thoroughly investigated by the Cameca SX100 microprobe at the Warsaw University and by the Quanta 250 Energy Dispersive Spectroscopy (EDS) at the Nature Research Centre in Vilnius, Lithuania. Four generations of magnetite were distinguished in the studied serpentine-magnetite ores (D8 drilling) and were compared with the earlier studied and reference magnetites. The earliest, spinel inclusion-rich magnetite cores (Mag-1) have the highest trace element contents (in wt%): Si (0.032), Al (0.167-0.248), Mg (0.340-0.405), Ti (0.215-0.254), V (0.090-0.138) etc. They might have formed during an early metamorphism and/or related skarn formation. Voluminous second magnetite (Mag-2) replacing olivine, pyroxenes, spinel and other skarn minerals at c. 540o C (Magnetite-Ilmenite geothermometer) has much lower trace element abundances, probably washed out by hydrothermal fluids. The latest magnetites (Mag-3 and Mag-4) overgrow the earlier ones and occur near or within the sulfide veins (Mag-4). As was observed from microtextures, the Mag-3 and Mag-4 have originated from the late thermal reworking by dissolution-reprecipitation processes. To imply an origin of the studied magnetites, they were compared to the earlier studied magmatic-metamorphic (1058 drilling), presumably skarn (982 drilling) magnetites from the studied area and plotted in the major magnetite ore type fields according to Dupuis and Beaudoin

  10. Granite-related Yangjiashan tungsten deposit, southern China

    Science.gov (United States)

    Xie, Guiqing; Mao, Jingwen; Li, Wei; Fu, Bin; Zhang, Zhiyuan

    2018-04-01

    The Yangjiashan scheelite-bearing deposit (38,663 metric tons of WO3 with an average ore grade of 0.70% WO3) is hosted in quartz veins in a biotite monzogranite intrusion and surrounding slate in the Xiangzhong Metallogenic Province of southern China. The monzogranite has a zircon SHRIMP U-Pb age of 406.6 ± 2.8 Ma (2σ, n = 20, MSWD = 1.4). Cassiterite coexisting with scheelite yields a weighted mean 206Pb/238U age of 409.8 ± 5.9 Ma (2σ, n = 30, MSWD = 0.20), and molybdenite intergrown with scheelite yields a weighted mean Re-Os age of 404.2 ± 3.2 Ma (2σ, n = 3, MSWD = 0.10). These results suggest that the Yangjiashan tungsten deposit is temporally related to the Devonian intrusion. The δD and calculated δ18OH2O values of quartz intergrown with scheelite range from - 87 to - 68‰, and - 1.2 to 3.4‰, respectively. Sulfides have a narrow range of δ34S values of - 2.9 to - 0.7‰ with an average value of - 1.6‰ (n = 16). The integration of geological, stable isotope, and geochronological data, combined with the quartz-muscovite greisen style of ore, supports a magmatic-hydrothermal origin for the tungsten mineralization. Compared to the more common tungsten skarn, quartz-wolframite vein, and porphyry tungsten deposits, as well as orogenic gold deposits worldwide, the Yangjiashan tungsten deposit is an unusual example of a granite-related, gold-poor, scheelite-bearing quartz vein type of deposit. The calcium needed for the formation of scheelite is derived from the sericitization of calcic plagioclase in the monzogranite and Ca-bearing psammitic country rocks, and the relatively high pH, reduced and Ca-rich mineralizing fluid may be the main reasons for the formation of scheelite rather than wolframite at Yangjiashan.

  11. Mesa-height Dependent Quantum Efficiency Characteristics of InGaN Micro-LEDs

    KAUST Repository

    Shen, Chao; Kang, Chun Hong; Ng, Tien Khee; Ooi, Boon S.

    2013-01-01

    The mechanisms of mesa-height dependent efficiency and efficiency droop of blue InGaN/GaN micro-LED is presented. Device with a large etch-depth (> 1.3 µm) shows significant strain relief with aggravated current crowding.

  12. 3D Tomography of a Mesa Using Cosmic Ray Muons Detected in an Underground Tunnel

    Science.gov (United States)

    Guardincerri, E.; Rowe, C. A.

    2016-12-01

    The LANL Mini Muon Tracker (MMT) is a muon tracking detector made of sealed aluminum drift tubes. The MMT was operated at four locations inside a tunnel under the Los Alamos town site mesa between November 2015 and February 2016 and it collected cosmic ray muons attenuated by the tunnel overburden. The data were analyzed and used to obtain a 3D tomographic image of the mesa and will be later combined with gravity data collected around the same location. We describe here the muon data taking and their analysis, and we show the resulting 3D image.

  13. Three-dimensional DFN Model Development and Calibration: A Case Study for Pahute Mesa, Nevada National Security Site

    Science.gov (United States)

    Pham, H. V.; Parashar, R.; Sund, N. L.; Pohlmann, K.

    2017-12-01

    Pahute Mesa, located in the north-western region of the Nevada National Security Site, is an area where numerous underground nuclear tests were conducted. The mesa contains several fractured aquifers that can potentially provide high permeability pathways for migration of radionuclides away from testing locations. The BULLION Forced-Gradient Experiment (FGE) conducted on Pahute Mesa injected and pumped solute and colloid tracers from a system of three wells for obtaining site-specific information about the transport of radionuclides in fractured rock aquifers. This study aims to develop reliable three-dimensional discrete fracture network (DFN) models to simulate the BULLION FGE as a means for computing realistic ranges of important parameters describing fractured rock. Multiple conceptual DFN models were developed using dfnWorks, a parallelized computational suite developed by Los Alamos National Laboratory, to simulate flow and conservative particle movement in subsurface fractured rocks downgradient from the BULLION test. The model domain is 100x200x100 m and includes the three tracer-test wells of the BULLION FGE and the Pahute Mesa Lava-flow aquifer. The model scenarios considered differ from each other in terms of boundary conditions and fracture density. For each conceptual model, a number of statistically equivalent fracture network realizations were generated using data from fracture characterization studies. We adopt the covariance matrix adaptation-evolution strategy (CMA-ES) as a global local stochastic derivative-free optimization method to calibrate the DFN models using groundwater levels and tracer breakthrough data obtained from the three wells. Models of fracture apertures based on fracture type and size are proposed and the values of apertures in each model are estimated during model calibration. The ranges of fracture aperture values resulting from this study are expected to enhance understanding of radionuclide transport in fractured rocks and

  14. Some selected research item of the micro mechanics department at MESA

    NARCIS (Netherlands)

    Elwenspoek, Michael Curt

    1994-01-01

    New developments within the micro mechanics department at MESA are presented. The developments are: (1) a description will be provided of dry etch processes-reactive ion etching, RIE-of silicon in a mixture of SF6, 02, and CHF3. (2) The design, fabrication and performance of new electrostatic

  15. 1.5-μm and 10-Gb s−1 etched mesa buried heterostructure DFB-LD for datacenter networks

    International Nuclear Information System (INIS)

    Kwon, Oh Kee; Lee, Chul Wook; Leem, Young Ahn; Kim, Ki Soo; Oh, Su Hwan; Nam, Eun Soo

    2015-01-01

    We report a 1.5 μm and 10 Gb s −1 etched mesa buried heterostructure λ/4-shifted distributed feedback laser diode (DFB-LD) for the low-cost application of WDM–based datacenter networks. To reduce the threshold current and improve the modulation bandwidth in a conventional p-/n-/p-InP current blocking structure, a thin undoped-InP (u-InP) layer was inserted between the side walls of the active region and the p-InP layer (i.e., a u-/p-/n-/p-InP structure), and the region containing the active region and the current blocking structures was etched in a mesa form (i.e., an etched mesa). From this work, it was found that a 300 μm long anti-reflection (AR)-AR DFB-LD with a mesa width of 8 μm is reduced by about 25% while a side mode suppression ratio is >50 dB and a 3 dB bandwidth is >10 GHz at a current of 40 mA; in addition, it shows a clear eye-opening with a dynamic extinction ratio of >4.5 dB at 10 Gb s −1 , and a power penalty of <1 dB after a 2 km transmission. (paper)

  16. EVALUACIÓN DEL DISEÑO DE UNA PEQUEÑA MESA VIBRATORIA PARA ENSAYOS EN INGENIERÍA SISMO-RESISTENTE

    Directory of Open Access Journals (Sweden)

    Julián Carrillo

    2013-01-01

    Full Text Available Las consecuencias catastróficas de los sismos han incentivado la realización de estudios experimentales para mitigar los efectos de los sismos sobre las estructuras. En el artículo se presenta la evaluación de los diseños mecánico, neumático, estructural, de control y de adquisición de datos, de una pequeña mesa vibratoria uniaxial para ensayos de estructuras a escala reducida. Inicialmente se eligieron los elementos mecánicos que permiten el movimiento de la mesa. Luego se validó el desempeño del sistema a partir de herramientas de simulación. Finalmente se estudió la automatización de la mesa por medio de un control con sistema de lazo abierto, implementado en un micro-controlador. La mesa vibratoria propuesta es una herramienta versátil y económica para realizar pruebas experimentales orientadas al análisis y diseño de estructuras sometidas a eventos sísmicos. El dispositivo propuesto promoverá la investigación no sólo en nuevos materiales, sino en diseño y rehabilitación de viviendas, edificios y puentes sismo-resistentes.

  17. Investigating the Influence of Regional Stress on Fault and Fracture Permeability at Pahute Mesa, Nevada National Security Site

    Energy Technology Data Exchange (ETDEWEB)

    Reeves, Donald M. [Desert Research Inst. (DRI), Reno, NV (United States); Smith, Kenneth D. [Univ. of Nevada, Reno, NV (United States); Parashar, Rishi [Desert Research Inst. (DRI), Reno, NV (United States); Collins, Cheryl [Desert Research Inst. (DRI), Las Vegas, NV (United States); Heintz, Kevin M. [Desert Research Inst. (DRI), Las Vegas, NV (United States)

    2017-05-24

    Regional stress may exert considerable control on the permeability and hydraulic function (i.e., barrier to and/or conduit for fluid flow) of faults and fractures at Pahute Mesa, Nevada National Security Site (NNSS). In-situ measurements of the stress field are sparse in this area, and short period earthquake focal mechanisms are used to delineate principal horizontal stress orientations. Stress field inversion solutions to earthquake focal mechanisms indicate that Pahute Mesa is located within a transtensional faulting regime, represented by oblique slip on steeply dipping normal fault structures, with maximum horizontal stress ranging from N29°E to N63°E and average of N42°E. Average horizontal stress directions are in general agreement with large diameter borehole breakouts from Pahute Mesa analyzed in this study and with stress measurements from other locations on the NNSS.

  18. Completion Report for Well ER-EC-15 Corrective Action Units 101 and 102: Central and Western Pahute Mesa

    Energy Technology Data Exchange (ETDEWEB)

    NSTec Environmental Management

    2011-05-31

    Well ER-EC-15 was drilled for the U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office in support of the Nevada Environmental Restoration Project at the Nevada National Security Site (formerly known as the Nevada Test Site), Nye County, Nevada. The well was drilled in October and November 2010, as part of the Pahute Mesa Phase II drilling program. The primary purpose of the well was to provide detailed hydrogeologic information in the Tertiary volcanic section in the area between Pahute Mesa and the Timber Mountain caldera complex that will help address uncertainties within the Pahute Mesa–Oasis Valley hydrostratigraphic model. In particular, the well was intended to help define the structural position and hydraulic parameters of volcanic aquifers potentially down-gradient from underground nuclear tests on Pahute Mesa. It may also be used as a long-term monitoring well.

  19. Completion Report for Well ER-EC-12 Corrective Action Units 101 and 102: Central and Western Pahute Mesa

    Energy Technology Data Exchange (ETDEWEB)

    NSTec Environmental Management

    2011-04-30

    Well ER-EC-12 was drilled for the U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office in support of the Nevada Environmental Restoration Project at the Nevada National Security Site (formerly known as the Nevada Test Site), Nye County, Nevada. The well was drilled in June and July 2010 as part of the Pahute Mesa Phase II drilling program. The primary purpose of the well was to provide detailed hydrogeologic information in the Tertiary volcanic section in the area between Pahute Mesa and the Timber Mountain caldera complex that will help address uncertainties within the Pahute Mesa–Oasis Valley hydrostratigraphic model. In particular, the well was intended to help define the structural position and hydraulic parameters for volcanic aquifers potentially down-gradient from historic underground nuclear tests on Pahute Mesa. It may also be used as a long-term monitoring well.

  20. Origin of the volcanic-hosted Yamansu Fe deposit, Eastern Tianshan, NW China: constraints from pyrite Re-Os isotopes, stable isotopes, and in situ magnetite trace elements

    Science.gov (United States)

    Huang, Xiao-Wen; Zhou, Mei-Fu; Beaudoin, Georges; Gao, Jian-Feng; Qi, Liang; Lyu, Chuan

    2018-01-01

    The Yamansu Fe deposit (32 Mt at 51% Fe) in the Eastern Tianshan Orogenic Belt of NW China is hosted in early Carboniferous volcano-sedimentary rocks and spatially associated with skarn. The paragenetic sequence includes garnet-diopside (I), magnetite (II), hydrous silicate-sulfide (III), and calcite-quartz (IV) stages. Pyrite associated with magnetite has a Re-Os isochron age of 322 ± 7 Ma, which represents the timing of pyrite and, by inference, magnetite mineralization. Pyrite has δ 34SVCDT values of - 2.2 to + 2.9‰, yielding δ 34SH2S values of - 3.1 to 2‰, indicating the derivation of sulfur from a magmatic source. Calcite from stages II and IV has δ 13CVPDB values from - 2.5 to - 1.2‰, and - 1.1 to 1.1‰, and δ 18OVSMOW values from 11.8 to 12.0‰ and - 7.7 to - 5.2‰, respectively. Calculated δ 13C values of fluid CO2 and water δ 18O values indicate that stage II hydrothermal fluids were derived from magmatic rocks and that meteoric water mixed with the hydrothermal fluids in stage IV. Some ores contain magnetite with obvious chemical zoning composed of dark and light domains in BSE images. Dark domains have higher Mg, Al, Ca, Mn, and Ti but lower Fe and Cr contents than light domains. The chemical zoning resulted from a fluctuating fluid composition and/or physicochemical conditions (oscillatory zoning), or dissolution-precipitation (irregular zoning) via infiltration of magmatic-hydrothermal fluids diluted by late meteoric water. Iron was mainly derived from fluids similar to that in skarn deposits.

  1. MESAFace, a graphical interface to analyze the MESA output

    Science.gov (United States)

    Giannotti, M.; Wise, M.; Mohammed, A.

    2013-04-01

    MESA (Modules for Experiments in Stellar Astrophysics) has become very popular among astrophysicists as a powerful and reliable code to simulate stellar evolution. Analyzing the output data thoroughly may, however, present some challenges and be rather time-consuming. Here we describe MESAFace, a graphical and dynamical interface which provides an intuitive, efficient and quick way to analyze the MESA output. Catalogue identifier: AEOQ_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEOQ_v1_0.html Program obtainable from: CPC Program Library, Queen’s University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 19165 No. of bytes in distributed program, including test data, etc.: 6300592 Distribution format: tar.gz Programming language: Mathematica. Computer: Any computer capable of running Mathematica. Operating system: Any capable of running Mathematica. Tested on Linux, Mac, Windows XP, Windows 7. RAM: Recommended 2 Gigabytes or more. Supplementary material: Additional test data files are available. Classification: 1.7, 14. Nature of problem: Find a way to quickly and thoroughly analyze the output of a MESA run, including all the profiles, and have an efficient method to produce graphical representations of the data. Solution method: We created two scripts (to be run consecutively). The first one downloads all the data from a MESA run and organizes the profiles in order of age. All the files are saved as tables or arrays of tables which can then be accessed very quickly by Mathematica. The second script uses the Manipulate function to create a graphical interface which allows the user to choose what to plot from a set of menus and buttons. The information shown is updated in real time. The user can access very quickly all the data from the run under examination and visualize it with plots and tables. Unusual features: Moving the

  2. The ideal table grapes for the Spanish market A uva de mesa ideal para o mercado espanhol

    Directory of Open Access Journals (Sweden)

    Cesar Rosso Piva

    2006-08-01

    Full Text Available This paper seeks to explore a survey of consumers in Spain. The survey explores the attributes of quality that consumers are seeking and promotion of grapes via "quality" marks, which are indicators of possible ways to increase demand. The reason consumers are switching to other foods, such as dairy based snacks, is that grapes are not easy to eat, can be unreliable in terms of their quality attributes, and their price more variable. Consumers are also generally unaware of the marks quality currently used.Este trabalho busca explorar o mercado da uva de mesa na Espanha, do ponto de vista do consumidor. O estudo explora os atributos de qualidade que os consumidores estão buscando e a promoção da uva de mesa via marcas de "qualidade" com a possibilidade de incremento de demanda. A importância deste estudo reside na mudança que vem ocorrendo no hábito de consumo de alimentos, onde as frutas e verduras em geral, e a uva de mesa em particular têm perdido espaço para produtos prontos para o consumo, como os derivados lácteos , doces e sobremesas. Em contraste, a uva de mesa não se apresenta pronta para o consumo, possui qualidade de fruta e preços mais variáveis, e o conceito de marca comercial encontra-se ainda pouco estabelecido, ao contrário dos produtos industrializados.

  3. Cancer incidence study in Mesa County, Colorado

    International Nuclear Information System (INIS)

    Ouimette, D.R.; Ferguson, S.W.; Zoglo, D.; Murphy, S.; Alley, S.; Bahler, S.

    1983-01-01

    In November of 1982 the Colorado Department of Health completed an epidemiologic investigation of leukemia, multiple myeloma, and cancers of the lung, stomach, pancreas and colon in Mesa County, Colorado for the years 1970 to 1979. This investigation was performed in response to a concern that the presence of uranium mill tailings in some Mesa County homes presents a potential cancer hazard. The results of the investigation show that the incidence of multiple myeloma, colon, stomach and pancreatic cancer are not above expected rates. The incidence of leukemia is not above expected rates for the entire study period, 1970 to 1979. The incidence of lung cancer appears elevated when compared to the The Third National Cancer Survey data for Colorado but lower than expected when compared to Surveillance, Epidemiology and End Results data. To further examine the leukemia and lung cancer incidence findings, a case/control study was conducted. The controls consisted of colon, stomach and pancreatic cancer cases. The results of the leukemia case/control analysis show no association with the radiation exposure variables: occupational radiation exposure; uranium mining exposure; having ever lived in a type A home (uranium tailings home); and radiation therapy. The lung cancer case/control analysis shows a significant association with only the radiation exposure variable, uranium mining history, indicating cases were more likely to have been uranium miners than were controls. As with leukemia, the study found no association between lung cancer and living in a uranium mill tailings home. The relatively low radiation exposures typical of type A homes and the small number of persons exposed make it very difficult to establish, by epidemiologic methods, that a risk exists

  4. Groundwater, surface-water, and water-chemistry data, Black Mesa area, northeastern Arizona: 2011-2012

    Science.gov (United States)

    Macy, Jamie P.; Unema, Joel A.

    2014-01-01

    The Navajo (N) aquifer is an extensive aquifer and the primary source of groundwater in the 5,400-square-mile Black Mesa area in northeastern Arizona. Availability of water is an important issue in northeastern Arizona because of continued water requirements for industrial and municipal use by a growing population and because of low precipitation in the arid climate of the Black Mesa area. Precipitation in the area typically is between 6 and 14 inches per year. The U.S. Geological Survey water-monitoring program in the Black Mesa area began in 1971 and provides information about the long-term effects of groundwater withdrawals from the N aquifer for industrial and municipal uses. This report presents results of data collected as part of the monitoring program in the Black Mesa area from January 2011 to September 2012. The monitoring program includes measurements of (1) groundwater withdrawals, (2) groundwater levels, (3) spring discharge, (4) surface-water discharge, and (5) groundwater chemistry. In 2011, total groundwater withdrawals were 4,480 acre-ft, industrial withdrawals were 1,390 acre-ft, and municipal withdrawals were 3,090 acre-ft. Total withdrawals during 2011 were about 39 percent less than total withdrawals in 2005 because of Peabody Western Coal Company’s discontinued use of water to transport coal in a slurry. From 2010 to 2011 total withdrawals increased by 11 percent; industrial withdrawals increased by approximately 19 percent, and total municipal withdrawals increased by 8 percent. From 2011 to 2012, annually measured water levels in the Black Mesa area declined in 8 of 15 wells that were available for comparison in the unconfined areas of the N aquifer, and the median change was -0.1 feet. Water levels declined in 9 of 18 wells measured in the confined area of the aquifer. The median change for the confined area of the aquifer was 0.0 feet. From the prestress period (prior to 1965) to 2012, the median water-level change for 34 wells in both

  5. Women's self-efficacy perceptions in mathematics and science: Investigating USC-MESA students

    Science.gov (United States)

    Hong, Rebecca Cheng-Shun

    This study is an investigation into female high school seniors in the USC-MESA program and how the role of self-efficacy perceptions in mathematics and science relates to their college major choice. Bandura's theory on self-efficacy provides the backdrop for this study. This study is qualitative and takes an ethnographic approach incorporating 23 interviews, 2 focus groups, 49.5 hours of observation, and document analysis. Results show that female high school seniors participating in the USC-MESA program demonstrate a strong self-efficacy perception in mathematics and science through their academic choices and pursuits in high school and beyond. This finding confirms a linear approach in understanding how courses taken in high school contribute to the trajectory of college academic choices. It also challenges the theory of self-efficacy in math and science to examine historically underrepresented populations in the field and the external factors that play a key role in their persistence to pursue STEM fields in college and beyond.

  6. Molybdenite Re/Os dating, zircon U-Pb age and geochemistry of granitoids in the Yangchuling porphyry W-Mo deposit (Jiangnan tungsten ore belt), China: Implications for petrogenesis, mineralization and geodynamic setting

    Science.gov (United States)

    Mao, Jingwen; Xiong, Bikang; Liu, Jun; Pirajno, Franco; Cheng, Yanbo; Ye, Huishou; Song, Shiwei; Dai, Pan

    2017-08-01

    The Yangchuling W-Mo deposit, located in the Jiangnan porphyry-skarn (JNB) tungsten ore belt, is the first recognized typical porphyry W-Mo deposit in China in the 1980's. Stockworks and disseminated W-Mo mineralization occur in the roof pendant of a 0.3 km2 monzogranitic porphyry stock that intruded into a granodiorite stock, hosted by Neoproterozoic phyllite and slate. LA-ICPMS zircon U-Pb analyses suggest that of the monzogranitic porphyry and granodiorite were formed at 143.8 ± 0.5 Ma and 149.8 ± 0.6 Ma, respectively. Six molybdenite samples yielded a Re-Os weighted mean age of 146.4 ± 1.0 Ma. Geochemical data show that both granodiorite and monzogranitic porphyry are characterized by enrichment of large ion lithophile elements (LILE) relative to high field strength elements (HFSE), indicating a peraluminous nature (A/CNK = 1.01-1.08). Two granitoids are characterized by a negative slope with significant light REE/heavy REE fractionation [(La/Yb)N = 8.38-23.20] and negative Eu anomalies (Eu/Eu* = 0.69-0.76). The P2O5 contents of the Yangchuling granitoids range from 0.12% to 0.17% and exhibit a negative correlation with SiO2, reflecting that they are highly fractionated I-type. They have high initial 87Sr/86Sr ratios (0.7104-0.7116), low negative εNd(t) (- 5.05 to - 5.67), and homogeneous εHf(t) between - 1.39 and - 2.17, indicating similar sources. Additionally, two-stage Nd model ages (TDM2) of 1.3-1.4 Ga and two-stage Hf model ages (TDM2) of 1.2-1.3 Ga are consistent, indicating that Neoproterozoic crustal rocks of the Shuangqiaoshan Group could have contributed to form the Yangchuling magmas. Considering the two groups of parallel Late Mesozoic ore belts, namely the Jiangnan porphyry-skarn tungsten belt (JNB) in the south and the Middle-Lower Yangtze River porphyry-skarn Cu-Au-Mo-Fe ore belt (YRB) in the north, the Nanling granite-related W-Sn ore belt (NLB) in the south, the neighboring Qin-Hang porphyry-skarn Cu-Mo-hydrothermal Pb-Zn-Ag ore belt (QHB

  7. Two-dimensional velocity models for paths from Pahute Mesa and Yucca Flat to Yucca Mountain

    International Nuclear Information System (INIS)

    Walck, M.C.; Phillips, J.S.

    1990-11-01

    Vertical acceleration recordings of 21 underground nuclear explosions recorded at stations at Yucca Mountain provide the data for development of three two-dimensional crystal velocity profiles for portions of the Nevada Test Site. Paths from Area 19, Area 20 (both Pahute Mesa), and Yucca Flat to Yucca Mountain have been modeled using asymptotic ray theory travel time and synthetic seismogram techniques. Significant travel time differences exist between the Yucca Flat and Pahute Mesa source areas; relative amplitude patterns at Yucca Mountain also shift with changing source azimuth. The three models, UNEPM1, UNEPM2, and UNEYF1, successfully predict the travel time and amplitude data for all three paths. 24 refs., 34 figs., 8 tabs

  8. Mesa Verde: A Study of Man in an Agricultural Setting. Library Packet.

    Science.gov (United States)

    Community Health Service (DHEW/PHS), Bethesda, MD.

    This collection of secondary readings contains general information about the ecology of living space, and specific information about the prehistory ecology of Mesa Verde, Colorado. There is also a section on how anthropologists use trees to date artifacts. A related document is indexed as ED 001 721. (AWW)

  9. Mineralogy and electron microprobe studies of magnetite in the Sarab-3 iron Ore deposit, southwest of the Shahrak mining region (east Takab

    Directory of Open Access Journals (Sweden)

    Mohammad Maanijou

    2018-04-01

    intruded into host rocks. Skarnification occurred at the two stages of progressive and regressive. At the progressive stage, the reaction of fluids and host rocks turned to the formation of anhydrous calc-silicate minerals such as garnet and clinopyroxene. At the regressive stage with the change of physicochemical conditions like decreasing temperature, these minerals converted to hydrous silicates (tremolite-actinolite, epidote and phyllosilcates (chlorite, serpentine, talk, and phlogopite. Also, minerals such as oxides (magnetite and hematite, sulfides (pyrite and chalcopyrite and calcite were formed. At a late stage, with activations of fluids, quartz-calcite mineralized veins formed. At the supergene stage, the oxidation process leads to the formation of alteration minerals from the main mineralization. Although there are magnesian minerals in the skarn, its main composition is calcic. The shape of the deposit is lentoid to horizontal and in some places bed formed along with some alteration halos. The ore minerals include low Ti-magnetite (with an average of 0.02 wt % Ti, hematite and sulfide minerals such as pyrite, pyrrhotite and chalcopyrite. Magnetite is the most important mineral with disseminated, vein, open-space filling, aggregate, accumulation, island and cataclastic textures. The magnetite at Sarab-3 is generated in 2 stages: At the first stage, magnetite has mass to mosaic textures that indicate the first phase of deposition in the area and at the second stage magnetite is gray magnetites that are placed as narrow bands around hematite or on the primary magnetite. Hematite in the area is formed either as hypogene hematite with plate or blade texture that is formed before the formation of early magnetite or supergene hematite that itself is formed due to alteration and weathering of magnetite in the superficial and shallow part of the deposit. In the surface area of the deposit, ore minerals are strongly altered to mixtures of oxide and hydroxide minerals

  10. Women's Self-Efficacy Perceptions in Mathematics and Science: Investigating USC-MESA Students

    Science.gov (United States)

    Hong, Rebecca C.; Jun, Alexander

    2012-01-01

    Higher education institutions have struggled with the underrepresentation of female students in the STEM majors. The authors investigate the USC-MESA program and the role of women's self-efficacy perceptions in mathematics and science. It is crucial to understand the theory of self-efficacy in examining historically underrepresented populations in…

  11. Re–Os isotope geochronology of the Shangbao pyrite–flourite deposit in southeastern Hunan, South China: Evidence for multiple mineralization events and the role of crust–mantle interaction in polymetallic deposits

    Directory of Open Access Journals (Sweden)

    Cheng-Cheng Huang

    2017-12-01

    Full Text Available In South China, both crustal reworking and crust–mantle interaction were important geological processes during the Paleozoic and Mesozoic eras. However, the relationships between these two processes and metal mineralization are still unknown. Here we report rhenium and osmium isotopic data for pyrite grains from a pyrite deposit associated with a granite intrusion in the Shangbao area, southeastern Hunan Province (South China. Two pyrite samples, both containing many euhedral pyrite grains, were collected from the same locality, but the samples yield distinct ages. Six euhedral pyrite grains from one sample yield an isochronal age of 279 ± 12 Ma, with an initial 187Os/188Os ratio of 0.39 ± 0.71, and Re and Os concentrations of 0.12–63.5 ppb and 2.14–185 ppt, respectively. This Early Permian age is in good agreement with the age of the strata that host the pyrite deposit. Five euhedral pyrite grains from the other sample yield an isochronal age of 75.2 ± 4.3 Ma, with an initial 187Os/188Os ratio of 0.141 ± 0.030 and Re and Os concentrations of 0.15–0.43 ppb and 1.0–39.9 ppt, respectively. If one pyrite grain with the highest 187Re/188Os and 187Os/188Os ratios is excluded, other four pyrite grains give an isochronal age of 85 ± 13 Ma. The Late Cretaceous age (75–85 Ma is consistent with the zircon U–Pb age of the Shangbao granites (80.1 ± 0.3 Ma to within uncertainties. Considering also the relatively lower radiogenic initial 187Os/188Os ratio of this sample, we suggest that the later stage pyrite ore was probably formed through crystallization from the magmatic hydrothermal fluids. Combined with other geological and associated magmatic data, we propose a skarn-related fluid–ore interaction process to explain the second stage of metallogenesis in the Shangbao pyrite deposit. The Early Permian pyrite ore was deposited in a brine basin with evaporites during the Early Permian. Later magmatic hydrothermal

  12. Programa para mejorar la atención en Mesas de Partes de la Corte Suprema de Justici

    OpenAIRE

    Pinto Malache, Rita Giovanna

    2016-01-01

    La presente investigación tuvo como objetivo general explicar el efecto del programa de capacitación en la atención que brindan las Mesas de Partes al usuario externo de la Corte Suprema de Justicia de la República del Perú. Año 2015; la población infinita, la muestra probabilística consideró 384 usuarios, en los cuales se ha empleado las variables: Programa de atención en mesa de partes y Atención al usuario. El método empleado en la investigación fue el hipotético deductivo,...

  13. Mesa Isochrones and Stellar Tracks (MIST). I. Solar-scaled Models

    Science.gov (United States)

    Choi, Jieun; Dotter, Aaron; Conroy, Charlie; Cantiello, Matteo; Paxton, Bill; Johnson, Benjamin D.

    2016-06-01

    This is the first of a series of papers presenting the Modules for Experiments in Stellar Astrophysics (MESA) Isochrones and Stellar Tracks (MIST) project, a new comprehensive set of stellar evolutionary tracks and isochrones computed using MESA, a state-of-the-art open-source 1D stellar evolution package. In this work, we present models with solar-scaled abundance ratios covering a wide range of ages (5≤slant {log}({Age}) [{year}]≤slant 10.3), masses (0.1≤slant M/{M}⊙ ≤slant 300), and metallicities (-2.0≤slant [{{Z}}/{{H}}]≤slant 0.5). The models are self-consistently and continuously evolved from the pre-main sequence (PMS) to the end of hydrogen burning, the white dwarf cooling sequence, or the end of carbon burning, depending on the initial mass. We also provide a grid of models evolved from the PMS to the end of core helium burning for -4.0≤slant [{{Z}}/{{H}}]\\lt -2.0. We showcase extensive comparisons with observational constraints as well as with some of the most widely used existing models in the literature. The evolutionary tracks and isochrones can be downloaded from the project website at http://waps.cfa.harvard.edu/MIST/.

  14. Mesa Verde: A Study of Man in an Agricultural Setting. Student Manual.

    Science.gov (United States)

    Community Health Service (DHEW/PHS), Bethesda, MD.

    This student manual contains information and guides to assist the secondary student in functioning as an archeologist. Included are fables, pictures for analysis, a time line and description of the pre-history of Mesa Verde, Colorado. The manual concludes with artifact identification word sheets. A related document is ED 001 722. (AWW)

  15. Groundwater, surface-water, and water-chemistry data, Black Mesa area, northeastern Arizona—2012–2013

    Science.gov (United States)

    Macy, Jamie P.; Truini, Margot

    2016-03-02

    The Navajo (N) aquifer is an extensive aquifer and the primary source of groundwater in the 5,400-square-mile Black Mesa area in northeastern Arizona. Availability of water is an important issue in northeastern Arizona because of continued water requirements for industrial and municipal use by a growing population and because of low precipitation in the arid climate of the Black Mesa area. Precipitation in the area typically is between 6 and 14 inches per year.The U.S. Geological Survey water-monitoring program in the Black Mesa area began in 1971 and provides information about the long-term effects of groundwater withdrawals from the N aquifer for industrial and municipal uses. This report presents results of data collected as part of the monitoring program in the Black Mesa area from January 2012 to September 2013. The monitoring program includes measurements of (1) groundwater withdrawals, (2) groundwater levels, (3) spring discharge, (4) surface-water discharge, and (5) groundwater chemistry.In calendar year 2012, total groundwater withdrawals were 4,010 acre-ft, industrial withdrawals were 1,370 acre-ft, and municipal withdrawals were 2,640 acre-ft. Total withdrawals during 2012 were about 45 percent less than total withdrawals in 2005 because of Peabody Western Coal Company’s discontinued use of water to transport coal in a coal slurry pipeline. From 2011 to 2012 total withdrawals decreased by 10 percent; industrial withdrawals decreased by approximately 1 percent, and total municipal withdrawals decreased by 15 percent.From 2012 to 2013, annually measured water levels in the Black Mesa area declined in 6 of 16 wells that were available for comparison in the unconfined areas of the N aquifer, and the median change was 0.8 feet. Water levels declined in 5 of 16 wells measured in the confined area of the aquifer. The median change for the confined area of the aquifer was 0.3 feet. From the prestress period (prior to 1965) to 2013, the median water

  16. Geohydrologic data and models of Rainier Mesa and their implications to Yucca Mountain

    International Nuclear Information System (INIS)

    Wang, J.S.Y.; Cook, N.G.W.; Wollenberg, H.A.; Carnahan, C.L.; Javandel, I.; Tsang, C.F.

    1993-01-01

    The geohydrologic data collected at Rainier Mesa provide the only extensive observations in tunnels presently available on flow and transport in tuff units similar to those of a potential nuclear waste repository at Yucca Mountain. This information can, therefore, be of great value in planning the Exploratory Studies Facility (ESF) testing in underground drifts at Yucca Mountain. In this paper, we compare the geohydrologic characteristics of tuff units of these two sites and summarize the hydrochemical data indicating the presence of nearly meteoric water in Rainier Mesa tunnels. A simple analytic model is used to evaluate the possibility of propagating transient pulses of water along fractures or faults through the Paintbrush nonwelded tuff unit to reach the tunnel beds below. The results suggest that fast flow could occur without significant mixing between meteoric fracture water and matrix pore water. The implications of these findings on planning for the ESF Calico Hills study at Yucca Mountain are discussed

  17. Mineral potential tracts for orogenic, Carlin-like, and epithermal gold deposits in the Islamic Republic of Mauritania, (phase V, deliverable 69): Chapter H in Second projet de renforcement institutionnel du secteur minier de la République Islamique de Mauritanie (PRISM-II)

    Science.gov (United States)

    Goldfarb, Richard J.; Marsh, Erin; Anderson, Eric D.; Horton, John D.; Finn, Carol A.; Beaudoin, Georges

    2015-01-01

    The gold resources of Mauritania presently include two important deposits and a series of poorly studied prospects. The Tasiast belt of deposits, which came into production in 2007, is located in the southwestern corner of the Rgueïbat Shield and defines a world-class Paleoproterozoic(?) orogenic gold ore system. The producing Guelb Moghrein deposit occurs along a shear zone in Middle Archean rocks at the bend in the Northern Mauritanides and is most commonly stated to be an iron oxide-copper-gold (IOCG) type of deposit, although it also has some important characteristics of orogenic gold and skarn deposits. Both major deposits are surrounded by numerous prospects that show similar mineralization styles. The Guelb Moghrein deposit, and IOCG deposit types in general are discussed in greater detail in a companion report by Fernette (2015). In addition, many small gold prospects, which are probably orogenic gold occurrences and are suggested to be early Paleozoic in age, occur along the length of Southern Mauritanides. Existing data indicate the gold deposits and prospects in Mauritania have a sulfide assemblage most commonly dominated by pyrrhotite and chalcopyrite, and have ore-related fluids with apparently high salinities.

  18. Groundwater, surface-water, and water-chemistry data, Black Mesa area, northeastern Arizona—2013–2015

    Science.gov (United States)

    Macy, Jamie P.; Mason, Jon P.

    2017-12-07

    The Navajo (N) aquifer is an extensive aquifer and the primary source of groundwater in the 5,400-square-mile Black Mesa area in northeastern Arizona. Availability of water is an important issue in northeastern Arizona because of continued water requirements for industrial and municipal use by a growing population and because of low precipitation in the arid climate of the Black Mesa area. Precipitation in the area typically is between 6 and 16 inches per year.The U.S. Geological Survey water-monitoring program in the Black Mesa area began in 1971 and provides information about the long-term effects of groundwater withdrawals from the N aquifer for industrial and municipal uses. This report presents results of data collected as part of the monitoring program in the Black Mesa area from January 2013 to December 2015. The monitoring program includes measurements of (1) groundwater withdrawals (pumping), (2) groundwater levels, (3) spring discharge, (4) surface-water discharge, and (5) groundwater chemistry.In 2013, total groundwater withdrawals were 3,980 acre-feet (ft), in 2014 total withdrawals were 4,170 acre-ft, and in 2015 total withdrawals were 3,970 acre-ft. From 2013 to 2015 total withdrawals varied by less than 5 percent.From 2014 to 2015, annually measured water levels in the Black Mesa area declined in 9 of 15 wells that were available for comparison in the unconfined areas of the N aquifer, and the median change was -0.1 feet. Water levels declined in 3 of 16 wells measured in the confined area of the aquifer. The median change for the confined area of the aquifer was 0.6 feet. From the prestress period (prior to 1965) to 2015, the median water-level change for 34 wells in both the confined and unconfined areas was -13.2 feet; the median water-level changes were -1.7 feet for 16 wells measured in the unconfined areas and -42.3 feet for 18 wells measured in the confined area.Spring flow was measured at four springs in 2014. Flow fluctuated during the

  19. [NIR and XRD analysis of drill-hole samples from Zhamuaobao iron-graphite deposit, Inner Mongolia].

    Science.gov (United States)

    Li, Ying-kui; Cao, Jian-jin; Wu, Zheng-quan; Dai, Dong-le; Lin, Zu-xu

    2015-01-01

    The author analyzed the 4202 drill-hole samples from Zhamuaobao iron-graphite deposit by using near infrared spectroscopy(NIR) and X-ray diffraction(XRD) measuring and testing techniques, and then compared and summarized the results of two kinds of testing technology. The results indicate that some difference of the mineral composition exists among different layers, the lithology from upper to deeper is the clay gravel layer of tertiary and quaternary, mudstone, mica quartz schist, quartz actinolite scarn, skarnization marble, iron ore deposits, graphite deposits and mica quartz schist. The petrogenesis in different depth also shows difference, which may indicate the geological characteristic to some extent. The samples had mainly undergone such processes as oxidization, carbonation, chloritization and skarn alteration. The research results can not only improve the geological feature of the mining area, but also have great importance in ore exploration, mining, mineral processing and so on. What's more, as XRD can provide preliminary information about the mineral composition, NIR can make further judgement on the existence of the minerals. The research integrated the advantages of both NIR and XRD measuring and testing techniques, put forward a method with two kinds of modern testing technology combined with each other, which may improve the accuracy of the mineral composition identification. In the meantime, the NIR will be more wildly used in geography on the basis of mineral spectroscopy.

  20. Nivel de aceptabilidad para cinco variedades de uva de mesa en el mercado español Nivel de aceitabilidade para cinco variedades de uva de mesa no mercado espanhol

    Directory of Open Access Journals (Sweden)

    Cesar Rosso Piva

    2006-04-01

    Full Text Available Con el objetivo de evaluar el nivel de aceptabilidad con relación a distintas variedades de uva de mesa, la Unidad de Comercialización y Divulgación Agraria del Departamento de Economía y Ciencias Sociales Agrarias (E.T.S.I.Agrónomos, de la Universidad Politécnica de Madrid, realizó la presente investigación en julio de 1999. Se utilizó el análisis sensorial en Sala de Catas como herramienta para la evaluación del nivel de aceptabilidad de cinco variedades de uva de mesa. Se puso énfasis en conocer las posibles diferencias de carácter sensorial entre las variedades Flame Seedless, Cardinal, Superior Seedless, Victoria y Redgloble, variedades que coinciden en su época de cosecha en España. En los análisis hechos, las variedades Cardinal y Superior Seedless fueron las más preferidas en comparación con Flame Seedless, Victoria y Redgloble. La variedad Superior Seedless fue muy valorada por su ausencia de semillas, además de su buen sabor, lo que la torna de gran potencial para el mercado español. El sabor, seguido de la jugosidad, fueron los elementos determinantes en el proceso de aceptación de la uva.Com o objetivo de avaliar o nível de aceitabilidade de distintas variedades de uva de mesa, a Unidade de Comercialização e Divulgação Agrária do Departamento de Economia y Ciências Sociales Agrárias (E.T.S.I. Agrónomos, da Universidade Politécnica de Madri, realizou o presente estudo em julho de 1999. Empregou-se a análise sensorial para a avaliação do nível de aceitabilidade de cinco variedades de uva de mesa. Procurou-se determinar especial atenção em conhecer as possíveis diferenças de caráter sensorial entre as variedades Flame Seedless, Cardinal, Superior Seedless, Victoria e Redgloble. Nos pomares espanhóis, essas variedades atingem a maturação de colheita na mesma época. Nas análises realizadas, as variedades Cardinal e Superior Seedless foram as mais preferidas em comparação com Flame Seedless

  1. Custo de produção de goiabas para mesa produzidas com e sem ensacamento: estudo de caso

    OpenAIRE

    Tatiane de Oliveira Tokairin; Fernando Perez Cappello; Marcel Bellato Spósito

    2014-01-01

    O ensacamento de goiabas para mesa tem por finalidade proteger os frutos contra o ataque de pragas, reduzir a aplicações e os níveis de resíduo de agroquímicos. O objetivo deste trabalho foi avaliar a sustentabilidade econômica da produção de goiabas, por meio da comparação do custo de produção entre os sistemas de cultivo com e sem ensacamento dos frutos. Foi realizado um estudo de caso com dados obtidos de uma propriedade comercial de goiabas para mesa no município de Valinhos - SP. O custo...

  2. Archaeological investigations on the Buckboard Mesa Road Project

    Energy Technology Data Exchange (ETDEWEB)

    Amick, D.S.; Henton, G.H.; Pippin, L.C.

    1991-10-01

    In 1986, the Desert Research Institute (DRI) conducted an archaeological reconnaissance of a new alignment for the Buckboard Mesa Road on the Nevada Test Site for the Department of Energy (DOE). During this reconnaissance, several archaeological sites of National Register quality were discovered and recorded including a large quarry, site 26Ny4892, and a smaller lithic scatter, site 26Ny4894. Analysis of the debitage at 26Ny4892 indicates that this area was used primarily as a quarry for relatively small cobbles of obsidian found in the alluvium. Lithic reduction techniques used here are designed for efficiently reducing small pieces of toolstone and are oriented towards producing flake blanks from small cores and bifacially reducing exhausted cores. Projectile point cross references indicate that the area has seen at least casual use for about 10,000 years and more sustained use for the last 3,000 years. Initial obsidian hydration measurements indicate sustained use of the quarry for about the last 3,000 years although the loci of activities appear to change over time. Based on this study, the DRI recommends that quarrying activities in the area of 26Ny4892 are sufficiently sampled and that additional investigations into that aspect of prehistoric activity in the area are not necessary. This does not apply to other aspects of prehistoric use. DRI recommends that preconstruction surveys continue to identify nonquarrying, prehistoric utilization of the area. With the increased traffic on the Buckboard Mesa Road, there is a greater potential for vandalism to sites of National Register-quality located near the road. The DRI recommends that during the orientation briefing the workers at the Test Site be educated about the importance of cultural resources and the need for their protection. 202 refs., 41 figs., 52 tabs.

  3. Summary and presentation of the international workshop on beam induced energy deposition (issues, concerns, solutions)

    International Nuclear Information System (INIS)

    Soundranayagam, R.

    1991-11-01

    This report discusses: energy deposition and radiation shielding in antriproton source at FNAL; radiation issues/problems at RHIC; radiation damage to polymers; radiation effects on optical fibre in the SSC tunnel; capabilities of the Brookhaven Radiation Effects Facility; the SSC interaction region; the FLUKA code system, modifications, recent extension and experimental verification; energy particle transport calculations and comparisons with experimental data; Los Alamos High Energy Transport code system; MCNP features and applications; intercomparison of Monte Carlo codes designed for simulation of high energy hadronic cascades; event generator, DTUJET-90 and DTUNUC; Preliminary hydrodynamic calculations of beam energy deposition; MESA code calculations of material response to explosive energy deposition; Smooth particle hydrodynamic; hydrodynamic effects and mass depletion phenomena in targets; beam dump: Beam sweeping and spoilers; Design considerations to mitigate effects of accidental beam dump; SSC beam abort and absorbed; beam abort system of SSC options; unconventional scheme for beam spoilers; low β quadrupoles: Energy deposition and radioactivation; beam induces energy deposition in the SSC components; extension of SSC-SR-1033 approach to radioactivation in LHC and SSC detectors; energy deposition in the SSC low-β IR-quads; beam losses and collimation in the LHC; and radiation shielding around scrapers

  4. An exploration hydrogeochemical study at the giant Pebble porphyry Cu-Au-Mo deposit, Alaska, USA, using high-resolution ICP-MS

    Science.gov (United States)

    Eppinger, Robert G.; Fey, David L.; Giles, Stuart A.; Kelley, Karen D.; Smith, Steven M.

    2012-01-01

    A hydrogeochemical study using high resolution ICP-MS was undertaken at the giant Pebble porphyry Cu-Au-Mo deposit and surrounding mineral occurrences. Surface water and groundwater samples from regional background and the deposit area were collected at 168 sites. Rigorous quality control reveals impressive results at low nanogram per litre (ng/l) levels. Sites with pH values below 5.1 are from ponds in the Pebble West area, where sulphide-bearing rubble crop is thinly covered. Relative to other study area waters, anomalous concentrations of Cu, Cd, K, Ni, Re, the REE, Tl, SO42− and F− are present in water samples from Pebble West. Samples from circum-neutral waters at Pebble East and parts of Pebble West, where cover is much thicker, have anomalous concentrations of Ag, As, In, Mn, Mo, Sb, Th, U, V, and W. Low-level anomalous concentrations for most of these elements were also found in waters surrounding nearby porphyry and skarn mineral occurrences. Many of these elements are present in low ng/l concentration ranges and would not have been detected using traditional quadrupole ICP-MS. Hydrogeochemical exploration paired with high resolution ICP-MS is a powerful new tool in the search for concealed deposits.

  5. Legal Knowledge as a Tool for Social Change: La Mesa por la Vida y la Salud de las Mujeres as an Expert on Colombian Abortion Law.

    Science.gov (United States)

    González Vélez, Ana Cristina; Jaramillo, Isabel Cristina

    2017-06-01

    In May 2006, Colombia's Constitutional Court liberalized abortion, introducing three circumstances under which the procedure would not be considered a crime: (1) rape or incest; (2) a risk to the woman's health or life; and (3) fetal malformations incompatible with life. Immediately following the court's ruling, known as Sentence C-355, members of La Mesa por la Vida y Salud de las Mujeres (hereinafter La Mesa) began to mobilize to ensure the decision's implementation, bearing in mind the limited impact that the legal framework endorsed by the court has had in other countries in the region. We argue that La Mesa's strategy is an innovative one in the field of legal mobilization insofar as it presumes that law can be shaped not just by public officials and universities but also by social actors engaged in the creation and diffusion of legal knowledge. In this regard, La Mesa has become a legal expert on abortion by accumulating knowledge about the multiple legal rules affecting the practice of abortion and about the situations in which these rules are to be applied. In addition, by becoming a legal expert, La Mesa has been able to persuade health providers that they will not risk criminal prosecution or being fired if they perform abortions. We call this effect of legal mobilization a "pedagogical effect" insofar as it involves the production of expertise and appropriation of knowledge by health professionals. We conclude by discussing La Mesa's choice to become a legal expert on abortion as opposed to recruiting academics to do this work or encouraging women to produce and disseminate this knowledge.

  6. Development of Phenomenological Models of Underground Nuclear Tests on Pahute Mesa, Nevada Test Site - BENHAM and TYBO

    Energy Technology Data Exchange (ETDEWEB)

    Pawloski, G.A.

    1999-09-21

    Although it is well accepted that underground nuclear explosions modify the in situ geologic media around the explosion point, the details of these changes are neither well understood nor well documented. As part of the engineering and containment process before a nuclear test, the physical environment is characterized to some extent to predict how the explosion will interact with the in situ media. However, a more detailed characterization of the physical environment surrounding an expended site is needed to successfully model radionuclide transport in the groundwater away from the detonation point. It is important to understand how the media have been altered and where the radionuclides are deposited. Once understood, this information on modified geologic media can be incorporated into a phenomenological model that is suitable for input to computer simulations of groundwater flow and radionuclide transport. The primary goals of this study are to (1) identify the modification of the media at a pertinent scale, and (2) provide this information to researchers modeling radionuclide transport in groundwater for the US Department of Energy (DOE) Nevada Operations Office Underground Test Area (UGTA) Project. Results from this study are most applicable at near-field scale (a model domain of about 500 m) and intermediate-field scale (a model domain of about 5 km) for which detailed information can be maximized as it is incorporated in the modeling grids. UGTA collected data on radionuclides in groundwater during recent drilling at the ER-20-5 site, which is near BENHAM and TYBO on Pahute Mesa at the Nevada Test Site (NTS). Computer simulations are being performed to better understand radionuclide transport. The objectives of this modeling effort include: evaluating site-specific information from the BENHAM and TYBO tests on Pahute Mesa; augmenting the above data set with generalized containment data; and developing a phenomenological model suitable for input to

  7. 77 FR 18997 - Rim Lakes Forest Restoration Project; Apache-Sitgreavese National Forest, Black Mesa Ranger...

    Science.gov (United States)

    2012-03-29

    ... DEPARTMENT OF AGRICULTURE Forest Service Rim Lakes Forest Restoration Project; Apache-Sitgreavese National Forest, Black Mesa Ranger District, Coconino County, AZ AGENCY: Forest Service, USDA. ACTION: Notice of intent to prepare an environmental impact statement. SUMMARY: The U.S. Forest Service (FS) will...

  8. Stormwater Pollution Prevention Plan TA-60 Roads and Grounds Facility and Associated Sigma Mesa Staging Area

    Energy Technology Data Exchange (ETDEWEB)

    Sandoval, Leonard Frank [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-02-01

    This Stormwater Pollution Prevention Plan (SWPPP) is applicable to operations at the Technical Area -60 (TA-60) Roads and Grounds Facility and Associated Sigma Mesa Staging Area off Eniwetok Drive, in Los Alamos County, New Mexico.

  9. Use of Earth Observation Data for Environmental Monitoring in the Horn of Africa within the Framework of MESA IGAD THEMA

    Science.gov (United States)

    Atheru, Zachary; Fortunate, Muyambi

    2015-12-01

    The achievements and challenges on the implementation of activities of IGAD Climate Prediction and Applications Centre (ICPAC) regarding the use of Earth Observation data for environmental monitoring in the Horn of Africa within the framework of MESA IGAD THEMA. Examples of the outputs from the Land Degradation Assessment, Natural Habitat Conservation and Forest Monitoring are provided and explained. The difficulties faced in communicating and disseminating information particularly to decision makers are highlighted. Also outlined is the scope and expected results from the Monitoring for Environment and Security in Africa (MESA) IGAD Thematic action and emphasis placed on lessons learnt on (i) developing services from products (ii) strengthening national networks (III) disseminating and communicating information to decision and policy makers, and (iv) capacity building. The overall objective of the MESA programme in the IGAD region is to enhance land degradation mitigation, natural habitats assessment and Forest Monitoring for sustainable management of environmental resources through the use of Earth Observation data. This is done by strengthening the Earth Observation information management capacity of regional and national institutions in order to support decision and policy making processes. The services produce and distribute regularly land degradation index maps, land cover change indicators on IGAD selected Natural Habitats areas, Forest degradation, deforestation extent, vulnerability index map. It also develops the political and policy frameworks that are strengthened to ensure an active and sustainable participation of IGAD member states in global environmental surveillance initiatives and finally give adequate technical capacity of MESA IGAD stakeholders.

  10. MESA models of the evolutionary state of the interacting binary epsilon Aurigae

    Science.gov (United States)

    Gibson, Justus L.; Stencel, Robert E.

    2018-06-01

    Using MESA code (Modules for Experiments in Stellar Astrophysics, version 9575), an evaluation was made of the evolutionary state of the epsilon Aurigae binary system (HD 31964, F0Iap + disc). We sought to satisfy several observational constraints: (1) requiring evolutionary tracks to pass close to the current temperature and luminosity of the primary star; (2) obtaining a period near the observed value of 27.1 years; (3) matching a mass function of 3.0; (4) concurrent Roche lobe overflow and mass transfer; (5) an isotopic ratio 12C/13C = 5 and, (6) matching the interferometrically determined angular diameter. A MESA model starting with binary masses of 9.85 + 4.5 M⊙, with a 100 d initial period, produces a 1.2 + 10.6 M⊙ result having a 547 d period, and a single digit 12C/13C ratio. These values were reached near an age of 20 Myr, when the donor star comes close to the observed luminosity and temperature for epsilon Aurigae A, as a post-RGB/pre-AGB star. Contemporaneously, the accretor then appears as an upper main-sequence, early B-type star. This benchmark model can provide a basis for further exploration of this interacting binary, and other long-period binary stars.

  11. DIVERSITY AND DISTRIBUTION OF PLASMODIAL MYXOMYCETES (SLIME MOLDS FROM LA MESA ECOPARK, QUEZON CITY, PHILIPPINES

    Directory of Open Access Journals (Sweden)

    THOMAS EDISON E. DELA CRUZ

    2010-10-01

    Full Text Available Myxomycetes are ubiquitous in terrestrial forest ecosystems. Thus, this research study looks at the taxonomic diversity and distribution of plasmodial myxomycetes in La Mesa Ecopark in Quezon City, Philippines. A total of 240 moist chambers were prepared from four substrates (aerial and ground leaf litter, twigs and barks collected within this ecopark. Following incubation of moist chambers for eight weeks, a total of 28 species belonging to 10 genera were collected and identified: Arcyria (3, Diderma (2, Didymium (5, Lamproderma (2, Perichaena (3, Physarum (8, Macbrideola (1, Metatrichia (1, Trichia (1 and Stemonitis (2. Highest myxomycete yield (85% was observed in aerial leaf litter. In terms of taxonomic diversity, highest diversity was observed in bark microhabitats, although the lowest number of species was recorded in it. Assessment of their abundance and distribution showed similarities in species composition between aerial and ground leaf litter. This research study is the first report of plasmodial myxomycetes in La Mesa Ecopark in Quezon City, Philippines.

  12. 78 FR 26771 - Mesa Wind Power Corporation; Supplemental Notice That Initial Market-Based Rate Filing Includes...

    Science.gov (United States)

    2013-05-08

    ... Wind Power Corporation's application for market-based rate authority, with an accompanying rate... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. ER13-1346-000] Mesa Wind Power Corporation; Supplemental Notice That Initial Market-Based Rate Filing Includes Request for...

  13. Streamflow Characteristics for Selected Stations In and Near the Grand Mesa, Uncompahgre, and Gunnison National Forests, Southwestern Colorado

    National Research Council Canada - National Science Library

    Kuhn, Gerhard

    2003-01-01

    The U.S Geological Survey, in cooperation with the Grand Mesa, Uncompahgre, and Gunnison National Forests, began a study in 2000 to develop selected streamflow characteristics for 60 streamflow-gaging...

  14. Hydraulic characterization of volcanic rocks in Pahute Mesa using an integrated analysis of 16 multiple-well aquifer tests, Nevada National Security Site, 2009–14

    Science.gov (United States)

    Garcia, C. Amanda; Jackson, Tracie R.; Halford, Keith J.; Sweetkind, Donald S.; Damar, Nancy A.; Fenelon, Joseph M.; Reiner, Steven R.

    2017-01-20

    An improved understanding of groundwater flow and radionuclide migration downgradient from underground nuclear-testing areas at Pahute Mesa, Nevada National Security Site, requires accurate subsurface hydraulic characterization. To improve conceptual models of flow and transport in the complex hydrogeologic system beneath Pahute Mesa, the U.S. Geological Survey characterized bulk hydraulic properties of volcanic rocks using an integrated analysis of 16 multiple-well aquifer tests. Single-well aquifer-test analyses provided transmissivity estimates at pumped wells. Transmissivity estimates ranged from less than 1 to about 100,000 square feet per day in Pahute Mesa and the vicinity. Drawdown from multiple-well aquifer testing was estimated and distinguished from natural fluctuations in more than 200 pumping and observation wells using analytical water-level models. Drawdown was detected at distances greater than 3 miles from pumping wells and propagated across hydrostratigraphic units and major structures, indicating that neither faults nor structural blocks noticeably impede or divert groundwater flow in the study area.Consistent hydraulic properties were estimated by simultaneously interpreting drawdown from the 16 multiple-well aquifer tests with an integrated groundwater-flow model composed of 11 well-site models—1 for each aquifer test site. Hydraulic properties were distributed across volcanic rocks with the Phase II Pahute Mesa-Oasis Valley Hydrostratigraphic Framework Model. Estimated hydraulic-conductivity distributions spanned more than two orders of magnitude in hydrostratigraphic units. Overlapping hydraulic conductivity ranges among units indicated that most Phase II Hydrostratigraphic Framework Model units were not hydraulically distinct. Simulated total transmissivity ranged from 1,600 to 68,000 square feet per day for all pumping wells analyzed. High-transmissivity zones exceeding 10,000 square feet per day exist near caldera margins and extend

  15. ERDA test facilities, East Mesa Test Site. Geothermal resource investigations, Imperial Valley, California

    Energy Technology Data Exchange (ETDEWEB)

    1976-01-01

    Detailed specifications which must be complied with in the construction of the ERDA Test Facilities at the East Mesa Site for geothermal resource investigations in Imperial Valley, California are presented for use by prospective bidders for the construction contract. The principle construction work includes a 700 gpm cooling tower with its associated supports and equipment, pipelines from wells, electrical equipment, and all earthwork. (LCL)

  16. Implantação das mesas nacionais de negociação permanente do Sistema Único de Saúde em secretarias estaduais e municipais de saúde

    Directory of Open Access Journals (Sweden)

    Carinne Magnago

    Full Text Available Resumo O objetivo deste artigo é avaliar a implantação da mesa de negociação permanente e identificar os entraves e os avanços decorridos dos processos de negociação no âmbito dos estados e dos municípios brasileiros. O método usado foi estudo descritivo e exploratório, de abrangência nacional. A coleta de dados se deu em 2012 e 2013, por meio de survey com 519 gestores de saúde e grupos focais com 49 gestores e 11 integrantes da Mesa Nacional de Negociação Permanente. Dados foram analisados por estatística descritiva e por análise de conteúdo. Verificou-se existência de 132 mesas de negociação, das quais apenas 87 estão em funcionamento. Os principais motivos para não implantação das mesas são a falta de assessoria técnica e a utilização de outras ferramentas para negociação do trabalho. As principais mudanças nas relações de trabalho em decorrência da atuação das mesas de negociação foram a realização de concursos e de processos seletivos públicos, políticas de desprecarização do trabalho e a implantação de planos de cargos, carreiras e salários. Conclui-se que apesar da potencialidade das mesas como dispositivos de negociação, sua implantação e seu pleno funcionamento esbarram em grandes desafios.

  17. Nové poznatky ze studia mineralogie, fluidních inkluzí a izotopů síry v rudách skarnového ložiska v Obřím dole

    Czech Academy of Sciences Publication Activity Database

    Pašava, J.; Veselovský, F.; Dobeš, P.; Haluzová, Eva; Ackerman, Lukáš; Tásler, R.

    2016-01-01

    Roč. 49, č. 1 (2016), s. 47-52 ISSN 0514-8057 R&D Projects: GA ČR GA13-15390S Institutional support: RVO:67985831 Keywords : Obří důl skarn-type deposit * mineralogy * fluid inclusions * sulfur isotopes Subject RIV: DB - Geology ; Mineralogy

  18. Data Report: Meteorological and Evapotranspiration Data from Sagebrush and Pinyon Pine/Juniper Communities at Pahute Mesa, Nevada National Security Site, 2011-2012

    Energy Technology Data Exchange (ETDEWEB)

    Jasoni, Richard L [DRI; Larsen, Jessica D [DRI; Lyles, Brad F. [DRI; Healey, John M [DRI; Cooper, Clay A [DRI; Hershey, Ronald L [DRI; Lefebre, Karen J [DRI

    2013-04-01

    Pahute Mesa is a groundwater recharge area at the Nevada National Security Site. Because underground nuclear testing was conducted at Pahute Mesa, groundwater recharge may transport radionuclides from underground test sites downward to the water table; the amount of groundwater recharge is also an important component of contaminant transport models. To estimate the amount of groundwater recharge at Pahute Mesa, an INFIL3.0 recharge-runoff model is being developed. Two eddy covariance (EC) stations were installed on Pahute Mesa to estimate evapotranspiration (ET) to support the groundwater recharge modeling project. This data report describes the methods that were used to estimate ET and collect meteorological data. Evapotranspiration was estimated for two predominant plant communities on Pahute Mesa; one site was located in a sagebrush plant community, the other site in a pinyon pine/juniper community. Annual ET was estimated to be 310±13.9 mm for the sagebrush site and 347±15.9 mm for the pinyon pine/juniper site (March 26, 2011 to March 26, 2012). Annual precipitation measured with unheated tipping bucket rain gauges was 179 mm at the sagebrush site and 159 mm at the pinyon pine/juniper site. Annual precipitation measured with bulk precipitation gauges was 222 mm at the sagebrush site and 227 mm at the pinyon pine/juniper site (March 21, 2011 to March 28, 2012). A comparison of tipping bucket versus bulk precipitation data showed that total precipitation measured by the tipping bucket rain gauges was 17 to 20 percent lower than the bulk precipitation gauges. These differences were most likely the result of the unheated tipping bucket precipitation gauges not measuring frozen precipitation as accurately as the bulk precipitation gauges. In this one-year study, ET exceeded precipitation at both study sites because estimates of ET included precipitation that fell during the winter of 2010-2011 prior to EC instrumentation and the precipitation gauges started

  19. Mesa redonda sobre nuevos modelos organizativos en la gestión de proyectos digitales

    OpenAIRE

    Taladriz Mas, Margarita; Magriñá Contreras, Marta; Martín Marichal, Carmen; Cabo Rigol, Mercé; X Workshop Rebiun sobre proyectos digitales. Valencia, 7-8 Octubre de 2010

    2010-01-01

    Mesa redonda dentro del X Workshop Rebiun sobre proyectos digitales, celebrado en Valencia, 7-8 Ocubre de 2010, sobre: Nuevos modelos organizativos en la gestión de proyectos digitales. Moderador: José Manuel Barrueco (UV). Intervienen: Margarita Taladriz Mas(UC3M), Marta Magriñá Contreras (UNIRIOJA), Carmen Martín Marichal (ULPGC) y Mercé Cabo Rigol (UPF).

  20. Accretion onto CO White Dwarfs using MESA

    Science.gov (United States)

    Feng, Wanda; Starrfield, Sumner

    2018-06-01

    The nature of type Ia Supernovae (SNe Ia) progenitor systems and their underlying mechanism are not well understood. There are two competing progenitor scenarios: the single-degenerate scenario wherein a white dwarf (WD) star accretes material from a companion star, reaching the Chandrasekhar mass limit; and, the double-degenerate scenario wherein two WDs merge. In this study, we investigate the single-degenerate scenario by accretion onto carbon-oxygen (CO) WDs using the Modules for Experiments in Stellar Astrophysics (MESA). We vary the WD mass, composition of the accreting material, and accretion rate in our models. Mixing between the accreted material and the WD core is informed by multidimensional studies that suggest occurance after thermonuclear runaway (TNR) ensues. We compare the accretion of solar composition material onto CO WDs with the accretion of mixed solar and core material after TNR. As many of our models eject less material than accreted, our study supports that accretion onto CO WDs is a feasible channel for SNe I progenitors.

  1. Modules for Experiments in Stellar Astrophysics (MESA): Convective Boundaries, Element Diffusion, and Massive Star Explosions

    OpenAIRE

    Paxton, Bill; Schwab, Josiah; Bauer, Evan B.; Bildsten, Lars; Blinnikov, Sergei; Duffell, Paul; Farmer, R.; Goldberg, Jared A.; Marchant, Pablo; Sorokina, Elena; Thoul, Anne; Townsend, Richard H. D.; Timmes, F. X.

    2017-01-01

    We update the capabilities of the software instrument Modules for Experiments in Stellar Astrophysics (MESA) and enhance its ease of use and availability. Our new approach to locating convective boundaries is consistent with the physics of convection, and yields reliable values of the convective core mass during both hydrogen and helium burning phases. Stars with $M

  2. Profesor Luis López de Mesa. Reminiscencias

    Directory of Open Access Journals (Sweden)

    J. Hernando Ordoñez

    1998-12-01

    Full Text Available

    Personalidad


    El 18 de Octubre pasado se cumplieron 30 años de la muerte del Profesor Luis López de Mesa, fecha luctuosa para la cultura americana. Con tal motivo quiero revivir su memoria y rendirle un cálido homenaje de gratitud y admiración, haciendo reminiscencias de hechos y anécdotas vividas gracias a la cordial amistad que me permitió apreciar la grandeza de su personalidad, que brilló con luz propia en todos los campos del saber humano, que lo llevó a escalar sitio de honor entre los grandes humanistas del continente.

    Sería un atrevimiento de mi parte, dada la poquedad de mis recursos literarios, intentar una biografía del profesor López de Mesa, tanto más, cuando eminentes autores han escrito obras magistrales relatando y exaltando las múltiples facetas de su excepcional cultura.

    Mi propósito es modesto: no he de referirme a su actuación como fundador del Colegio Máximo de las Academias Colombianas, ni de su hija “Bahía Solano”, ni del brillo con que desempeñó cargos tan importantes como Rector de la Universidad Nacional, Ministro de Educación Nacional y de Relaciones Exteriores, miembro de las más prestigiosas sociedades científicas y culturales, tanto nacionales como extranjeras, autor de numerosas obras a cual más eruditas, originales y profundas, y tantos títulos, cargos y actuaciones, que me sería largo enumerar.

    La sencillez y su modestia fueron admirables, como han sido las de los grandes genios. No conoció la vanidad ni el orgullo. Casi me atrevería a pensar que no se dio cuenta de su propia grandeza, a pesar de los múltiples y más variados elogios, honores y homenajes que le rendían tanto en el ambiente nacional como en el internacional, donde contaba con la admiración de los más brillantes exponentes de la cultura, que, distantes, se admiran recíprocamente, como de lejos se divisan y se contemplan las más elevadas cumbres de las monta

  3. Predicted Geology of the Pahute Mesa-Oasis Valley Phase II Drilling Initiative

    International Nuclear Information System (INIS)

    2009-01-01

    Pahute Mesa-Oasis Valley (PM-OV) Phase II drilling will occur within an area that encompasses approximately 117 square kilometers (45 square miles) near the center of the Phase I PM-OV hydrostratigraphic framework model area. The majority of the investigation area lies within dissected volcanic terrain between Pahute Mesa on the north and Timber Mountain on the south. This area consists of a complex distribution of volcanic tuff and lava of generally rhyolitic composition erupted from nearby calderas and related vents. Several large buried volcanic structural features control the distribution of volcanic units in the investigation area. The Area 20 caldera, including its structural margin and associated caldera collapse collar, underlies the northeastern portion of the investigation area. The southern half of the investigation area lies within the northwestern portion of the Timber Mountain caldera complex, including portions of the caldera moat and resurgent dome. Another significant structural feature in the area is the west-northwest-trending Northern Timber Mountain moat structural zone, which bisects the northern portion of the investigation area and forms a structural bench. The proposed wells of the UGTA Phase II drilling initiative can be grouped into four generalized volcanic structural domains based on the stratigraphic distribution and structural position of the volcanic rocks in the upper 1,000 meters (3,300 feet) of the crust, a depth that represents the approximate planned total depths of the proposed wells

  4. Variation in the annual average radon concentration measured in homes in Mesa County, Colorado

    International Nuclear Information System (INIS)

    Rood, A.S.; George, J.L.; Langner, G.H. Jr.

    1990-04-01

    The purpose of this study is to examine the variability in the annual average indoor radon concentration. The TMC has been collecting annual average radon data for the past 5 years in 33 residential structures in Mesa County, Colorado. This report is an interim report that presents the data collected up to the present. Currently, the plans are to continue this study in the future. 62 refs., 3 figs., 12 tabs

  5. Surface motion induced by nuclear explosions beneath Pahute Mesa. Part I. Halfbreak, Greeley, Scotch, Boxcar events

    International Nuclear Information System (INIS)

    Perret, W.R.

    1976-10-01

    Results of surface motion studies conducted by Sandia Laboratories during seven underground nuclear explosions detonated beneath Pahute Mesa, Areas 19 and 20 of the Nevada Test Site, between 1966 and 1973 are reported. The report is divided into two parts of which this, Part I, includes (1) descriptions of the Pahute Mesa geological environment and of the purposes and instrumentation used in these programs (Chapter 1), and (2) description of four events, the data derived from each, and analysis of these data. These Part I events are HALFBEAK (Chapter 2), GREELEY (Chapter 3), SCOTCH (Chapter 4), and BOXCAR (Chapter 5) for all of which a nominally radial array of gage stations yielded data as a function of distance primarily, although in a few cases data were derived from stations at widely separated azimuths from the explosion. Results of the analysis indicate that average propagation velocity through the geologic column between the explosions and mesa surface was about 8800 ft/sec and that for horizontal distances greater than shot depth, refraction occurred within rhyolite flows with characteristic velocity of about 12,300 ft/sec. There is evidence which suggests possible deeper refraction at a velocity between 18,000 and 21,000 ft/sec. Only the verticle motion peaks follow a pattern amenable to regression analysis because geometrical effects influence horizontal motion amplitudes differently as horizontal distances increase. Particle velocities vary roughly as the inverse square of slant or radial range with exponent values ranging from -3.9 to -1.3. Displacements follow a similar pattern with exponents ranging from about -6 to -2. Displacement profiles at various times during the motion and displacement hodographs in the vertical-radial plane aid in understanding several local phenomena implied by individual motion records

  6. Propuesta de mejora continua para la mesa de ayuda de la UGPP

    OpenAIRE

    2012-01-01

    El propósito del Mejoramiento Continuo del Servicio (MCS) es alinear y realinear continuamente los servicios de TI con las necesidades cambiantes del negocio por medio de la identificación e implementación de mejoras a los servicios de TI que respaldan los Procesos del Negocio. Para esta Organización en particular se cumplieron tres etapas: La primera un diagnóstico del estado actual de proceso de mesa de ayuda, de la herramienta de apoyo a la gestión de incidentes y al equipo humano de sopo...

  7. Mesa NTMS 10 x 20 quadrangle area. Supplemental data report

    International Nuclear Information System (INIS)

    Koller, G.R.

    1980-01-01

    This data report presents supplemental analytical results for stream sediments and ground water. The samples were collected as part of the SRL-NURE reconnaissance in the National Topographic Map Series (NTMS) Mesa 1 0 x 2 0 quadrnangle. Results are reported for 24 elements (Ag, As, Ba, Be, Ca, Co, Cr, Cu, K, Li, Mg, Mo, Nb, Ni, P, Pb, Se, Sn, Sr, Th, W, Y, Zn, and extractable U) in sediments and 31 elements (Ag, Al, As, B, Ba, Be, Ca, Ce, Co, Cr, Cu, Fe, K, Li, Mg, Mn, Mo, Na, Nb, Ni, P, Sc, Se, Si, Sr, Th, Ti, V, Y, Zn, and Zr) as well as pH, alkalinity, and conductivity in ground water

  8. Stormwater Pollution Prevention Plan - TA-60 Roads and Grounds Facility and Associated Sigma Mesa Staging Area

    Energy Technology Data Exchange (ETDEWEB)

    Sandoval, Leonard Frank [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2018-01-31

    This Storm Water Pollution Prevention Plan (SWPPP) was developed in accordance with the provisions of the Clean Water Act (33 U.S.C. §§1251 et seq., as amended), and the Multi-Sector General Permit for Storm Water Discharges Associated with Industrial Activity (U.S. EPA, June 2015) issued by the U.S. Environmental Protection Agency (EPA) for the National Pollutant Discharge Elimination System (NPDES) and using the industry specific permit requirements for Sector P-Land Transportation and Warehousing as a guide. This SWPPP applies to discharges of stormwater from the operational areas of the TA-60 Roads and Grounds and Associated Sigma Mesa Staging Area at Los Alamos National Laboratory. Los Alamos National Laboratory (also referred to as LANL or the “Laboratory”) is owned by the Department of Energy (DOE), and is operated by Los Alamos National Security, LLC (LANS). Throughout this document, the term “facility” refers to the TA-60 Roads and Grounds and Associated Sigma Mesa Staging Area. The current permit expires at midnight on June 4, 2020.

  9. Spectral investigation of hot-spot and cavity resonance effects on the terahertz radiation emitted from high-Tc superconducting Bi2Sr2CaCu2O8+δ single crystal mesa structures

    Science.gov (United States)

    Kadowaki, Kazuo; Watanabe, Chiharu; Minami, Hidetoshi; Yamamoto, Takashi; Kashiwagi, Takanari; Klemm, Richard

    2014-03-01

    Terahertz (THz) electromagnetic radiation emitted from high-Tc superconducting Bi2Sr2CaCu2O8+δ mesa structures in the case of single mesa and series-connected mesas is investigated by the FTIR spectroscopic technique while observing its temperature distribution simultaneously by a SiC photoluminescence technique. Changing the bias level, sudden jumps of the hot-spot position were clearly observed. Although the radiation intensity changes drastically associated with the jump of the hot spot position, the frequency is unaffected as long as the voltage per junction is kept constant. Since the frequency of the intense radiation satisfies the cavity resonance condition, we confirmed that the cavity resonance is of primarily importance for the synchronization of whole intrinsic Josephson junctions in the mesa for high power radiation. This work was supported in part by the Grant-in-Aid for challenging Exploratory Research, the Ministry of Education, Culture, Sports, Science & Technology (MEXT).

  10. Time-location patterns of a diverse population of older adults: the Multi-Ethnic Study of Atherosclerosis and Air Pollution (MESA Air).

    Science.gov (United States)

    Spalt, Elizabeth W; Curl, Cynthia L; Allen, Ryan W; Cohen, Martin; Adar, Sara D; Stukovsky, Karen H; Avol, Ed; Castro-Diehl, Cecilia; Nunn, Cathy; Mancera-Cuevas, Karen; Kaufman, Joel D

    2016-06-01

    The primary aim of this analysis was to present and describe questionnaire data characterizing time-location patterns of an older, multiethnic population from six American cities. We evaluated the consistency of results from repeated administration of this questionnaire and between this questionnaire and other questionnaires collected from participants of the Multi-Ethnic Study of Atherosclerosis and Air Pollution (MESA Air). Participants reported spending most of their time inside their homes (average: 121 h/week or 72%). More than 50% of the participants reported spending no time in several of the location options, including at home outdoors, at work/volunteer/school locations indoors or outdoors, or in "other" locations outdoors. We observed consistency between self-reported time-location patterns from repeated administration of the time-location questionnaire and compared with other survey instruments. Comparisons with national cohorts demonstrated the differences in time-location patterns in the MESA Air cohort due to differences in demographics, but the data showed similar trends in patterns by age, gender, season, and employment status. This study was the first to explicitly examine the time-location patterns in an older, multiethnic population and the first to add data on Chinese participants. These data can be used to inform future epidemiological research of MESA Air and other studies that include diverse populations.

  11. 'Black star': uma mutação somática natural da uva fina de mesa cv. Brasil

    Directory of Open Access Journals (Sweden)

    Sergio Ruffo Roberto

    2012-09-01

    Full Text Available A uva fina de mesa 'Black Star', originada de uma mutação somática da uva cv. Brasil em Marialva-PR, é descrita quanto às suas principais características físico-químicas e produtivas. Suas bagas, com sementes, apresentam formato elipsoide alongado com coloração vermelho-escura, tendendo ao preto durante a maturação plena. O ciclo, o desempenho produtivo e a suscetibilidade às doenças fúngicas assemelham-se aos da cv. Itália. Durante a maturação plena, apresenta teor médio de sólidos solúveis de 14ºBrix, 0,6% de ácido tartárico e índice de maturação de 21. Trata-se de nova cultivar de uva fina de mesa com potencial de cultivo no Brasil.

  12. Characterization of Mesa Verde Black-on-white ceramics from southwestern Colorado using NAA

    Energy Technology Data Exchange (ETDEWEB)

    Glowacki, D M; Neff, H; Glascock, M D [Missouri Univ., Columbia, MO (United States). Research Reactor Facility

    1995-10-01

    Sixty Mesa Verde variety Black-on-white bowls from Castle Rock Pueblo (5MT 1825) and Sand Canyon Pueblo (5MT765) in southwestern Colorado were chemically characterized using neutron activation analysis. Eleven clay sources local to the sites in the McElmo Drainage area were also analyzed. The results revealed two distinct compositional groups containing relative frequencies that imply local production. The occurrence of trade between the two sites was also identified. (author). 20 refs., 5 figs., 2 tabs.

  13. Is the Mesa Central of Mexico a biogeographical province? Descriptive analysis based on freshwater biotic components ¿La mesa central de México es una provincia biogeográfica? Análisis descriptivo basado en componentes bióticos dulceacuícolas

    Directory of Open Access Journals (Sweden)

    Omar Domínguez-Domínguez

    2009-12-01

    Full Text Available This essay presents an analysis of the concept of Mesa Central of México as a potential biogeographical province. This region of México has been used as a reference for describing species richness and distribution patterns of the freshwater fish fauna. However, it has not been recognized as a biogeographical province in the available schemes which are mostly based on the composition of terrestrial biota. Here, we provide a historical sketch of the way the concept of Mesa Central arose in the literature as a physiographic province, and we provide a comparison with respect to the regionalization schemes of the Mexican territory, which are based on attributes such physiography, elevation, hydrology, geology and biogeography. We conclude that the Mesa Central, even though it represents a practical concept for establishing the distribution pattern of the fish fauna, in the way it was described originally cannot be circumscribed to any of the regions or provinces in which Mexico has been divided. We also argue that this geographical region cannot be considered as a synonym of the Transmexican Volcanic Axis biogeographical province, and also that it is possible that the fact that this area is not circumscribed to any regionalization scheme is due to the fact that freshwater elements have not been considered in the establishment of such biogeographical regions. We end by pointing out the need for a biogeographical analysis that integrates most of the freshwater elements in order to determine whether both the aquatic and terrestrial flora and fauna are driven by the same geobiotic processes.En este ensayo se presenta un análisis del concepto de Mesa Central de México como una posible provincia biogeográfica. Esta región del país ha sido utilizada como referencia para describir la riqueza y distribución de una parte importante de la fauna ictiológica dulceacuícola, sin embargo, no es reconocida como provincia biogeográfica en ninguno de los

  14. Geochronology and geochemistry constraints of the Early Cretaceous Taibudai porphyry Cu deposit, northeast China, and its tectonic significance

    Science.gov (United States)

    Zhou, Zhen-Hua; Mao, Jing-Wen; Wu, Xin-Li; Ouyang, Hen-Gen

    2015-05-01

    The southern Great Xing'an Range (SGXR), located in the southeastern part of Inner Mongolia, China, shows intense Mesozoic tectono-magmatic activity and hosts economically important polymetallic (Cu-Pb-Zn-Sn-Fe-Ag-Au-Mo) mineralization. Here, we present new zircon U-Pb ages, whole-rock geochemical data, Nd-Sr-Hf isotopic data and Re-Os ages for the Taibudai deposit in the SGXR. The Taibudai granitoids show high SiO2 (70.62-72.13 wt.%) and alkali (Na2O + K2O = 7.04-8.60 wt.%) concentrations, low MgO (0.89-1.37 wt.%) and Al2O3 (∼14 wt.%), ASI ratios molybdenite from the deposit yield an ore-forming age of 137.1 ± 1.4 Ma. Re contents range from 4.37 to 41.77 ppm, implying ore material components have a mixed crust-mantle origin. SHRIMP analysis of zircons show that the monzogranitic porphyry and biotite granite in the Taibudai deposit were formed at 137.0 ± 0.9 Ma and 138.3 ± 0.9 Ma, respectively, indicating a temporal link between granitic magmatism and Cu mineralization. This result, combined with the regional geology, tectonic evolution, and age data from the literature, suggests that the Early Cretaceous (∼140 Ma) was the peak metallogenic epoch for the Great Xing'an Range, and the mineralization in this period generally takes the form of porphyry, skarn, or hydrothermal polymetallic ore deposits in an active extensional continental margin environment. The Taibudai porphyry and associated mineralization provides a typical example of magmatism and metallogeny associated with a Paleo-Pacific plate subduction, continental margin, back-arc extensional setting.

  15. Sociolingüística y etnografía: análisis de interacciones en la Mesa de grupos auto-gestionados

    Directory of Open Access Journals (Sweden)

    Heras Monner Sans, Ana Inés

    2014-01-01

    Full Text Available [es] Presentamos un análisis de un dispositivo de reflexión sobre la práctica auto-gestionada denominado “Mesa Colectiva”,conformado por representantes de seis organizaciones de Argentina. Nuestro análisis busca responder: ¿Qué formas asume la construcción de conocimiento en la Mesa Colectiva?¿Cuáles son los contenidos que las organizaciones construyen para interpelar su acción colectiva? Aportamos una perspectiva poco trabajada en lo que refiere a la auto gestión,ya que, en tanto los grupos auto-gestionados se conforman como espacios de acción política, sus prácticas e interacciones no resultan fáciles de documentar y sistematizar.Quienes escribimos este artículo somos participantes en la Mesa (pertenecemos a una de las organizaciones participantesy también en la institución que formuló el proyecto de investigación. Este doble posicionamiento nos permite construir conocimiento en colaboración, sistematizarlo y analizarlo, poniéndolo a disposición para la discusión a través de diversos canales de comunicación (multimedia, performances,encuentros abiertos. Además, nuestro aporte es original en tanto tomamos una perspectiva sociolingüística combinada con la etnografía, metodológica y teóricamente,para analizar el aprendizaje. Nuestro análisis da cuenta deque hay una estrecha relación entre la Mesa Colectiva como dispositivo, los géneros discursivos que se construyen entre los participantes, y los contenidos que se van elaborando acerca de la autonomía como proyecto. Creemos aportar un punto de partida innovador para analizar la relación entre los contenidos que sustentan a la autonomía como proyecto y las formas que asumen esos contenidos en las prácticas de reflexión e interacción de los grupos auto-gestionados.

  16. El Profesor López de Mesa o la Fe en el Valor de las Ideas.

    Directory of Open Access Journals (Sweden)

    Jaime Posada Diaz

    1998-12-01

    Full Text Available

    En estos meses, desde finales de 1997, los sectores cultos del país han venido pensando en conmemorar los treinta años del fallecimiento, en Medellín, del profesor Luis López de Mesa. Esta noche las Academias Colombianas se congregan para rendir homenaje a la memoria de quien fue miembro titular de la mayoría de ellas, en todas las cuales supo afianzar los rasgos de su personalidad sorprendente y respetada.
    Analizar un sistema de pensamiento tan versátil y complejo como el del profesor Luis López de Mesa sería faena de largo tiempo. De ahí que prudente, en ocasión como la de esta noche, sea reparar en aspectos concretos.

    En buena parte de las páginas que va a leer el Presidente del colegio Máximo usará los verbos en presente. Una manera de reconocer la vigencia, la actualidad, de las tesis del reconocido erudito.

    El profesor legó sus archivos a la Universidad de Antioquia que ha publicado varios libros con parte de esos materiales. En uno de ellos se presenta, al comienzo, una interpretación que se acoge como portada a las palabras que van a escucharse . Es la siguiente :

    “Cultor de las letras, científico, diplomático, expositor excepcional en el campo político y en de las disciplinas profesionales, orador majestuoso con un insigne dominio del don de la palabra, novelista, ensayista, investigador de las ciencias sociales, director universitario, fue el Profesor López de Mesa figura cimera de la inteligencia colombiana y rector admirable de su espíritu. Símbolo intelectual y moral de la generación del centenario, descolló en medio de figuras tan sobresalientes como las de Enrique Olaya Herrera, Alfonso López, Laureano Gómez, Aquilino Villegas, los hermanos Nieto Caballero, entre tantos varones ilustres”...

  17. NORTH END ROADLESS AREA, ARIZONA.

    Science.gov (United States)

    Drewes, Harald; Bigsby, P.R.

    1984-01-01

    Studies conducted in the North End Roadless Area, Arizona indicate probable or substantiated metallic mineral-resource potential in about one-fifth of the area. The area has potential for disseminated or stockwork-type molybdenum mineralization, copper-lead-zinc-silver veins, lead-zinc-silver limestone replacement deposits, and tungsten-bearing contact metamorphic skarn deposits. The area also contains cement rock and marble dimension stone, but has only slight promise for the occurrence of petroleum and natural gas.

  18. Factors Controlling Pre-Columbian and Early Historic Maize Productivity in the American Southwest, Part 2: The Chaco Halo, Mesa Verde, Pajarito Plateau/Bandelier, and Zuni Archaeological Regions

    Science.gov (United States)

    Benson, L.V.

    2011-01-01

    Chemical and nutrient analyses of 471 soil samples from 161 sites within four archaeological regions (Pajarito Plateau/Bandelier, Zuni, Mesa Verde, and the Chaco Halo) were combined with historical climate data in order to evaluate the agricultural productivity of each region. In addition, maize productivity and field-life calculations were performed using organic-nitrogen (N) values from the upper 50 cm of soil in each region and a range (1-3%/year) of N-mineralization rates. The endmember values of this range were assumed representative of dry and wet climate states. With respect to precipitation and heat, the Pajarito Plateau area has excellent agricultural potential; the agricultural potentials of the Zuni and Mesa Verde regions are good; and the agricultural potential of the Chaco Halo is poor. Calculations of N mineralization and field life indicate that Morfield Valley in Mesa Verde should be able to provide 10 bu/ac of maize for decades (without the addition of N) when organic N-mineralization rates exceed 2%. Productivity and field-life potential decrease in the following order: Zuni, Mesa Verde, Bandelier, Chaco Halo. The Chaco Halo is very unproductive; e. g., 10 bushels per acre can be achieved within the Halo only from soils having the highest organic N concentration (third quartile) and which undergo the highest rate (3%) of N mineralization. ?? 2010 US Government.

  19. The MESA polarimetry chain and the status of its double scattering polarimeter

    International Nuclear Information System (INIS)

    Aulenbacher, K.; Bartolomé, P. Aguar; Molitor, M.; Tioukine, V.

    2013-01-01

    We plan to have two independent polarimetry systems at MESA based on totally different physical processes. A first one tries to minimize the systematic uncertainties in double polarized Mo/ller scattering, which is to be achieved by stored hydrogen atoms in an atomic trap (Hydro-Mo/ller-Polarimeter). The other one relies on the equality of polarizing and analyzing power which allows to measure the effective analyzing power of a polarimeter with very high accuracy. Since the status of Hydro-Mo/ller is presented in a separate paper we concentrate on the double scattering polarimeter in this article

  20. GIS surface effects archive of underground nuclear detonations conducted at Yucca Flat and Pahute Mesa, Nevada Test Site, Nevada

    International Nuclear Information System (INIS)

    Grasso, D.N.

    2001-01-01

    This report presents a new comprehensive, digital archive of more than 40 years of geologic surface effects maps produced at individual detonation sites throughout the Yucca Flat and Pahute Mesa nuclear testing areas of the Nevada Test Site, Nye County, Nevada. The Geographic Information System (GIS) surface effects map archive on CD-ROM (this report) comprehensively documents the surface effects of underground nuclear detonations conducted at two of the most extensively used testing areas of the Nevada Test Site. Between 1951 and 1992, numerous investigators of the U.S. Geological Survey, the Los Alamos National Laboratory, the Lawrence Livermore National Laboratory, and the Defense Threat Reduction Agency meticulously mapped the surface effects caused by underground nuclear testing. Their work documented the effects of more than seventy percent of the underground nuclear detonations conducted at Yucca Flat and all of the underground nuclear detonations conducted at Pahute Mesa

  1. TYBO/BENHAM: Model Analysis of Groundwater Flow and Radionuclide Migration from Underground Nuclear Tests in Southwestern Pahute Mesa, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    Andrew Wolfsberg; Lee Glascoe; Guoping Lu; Alyssa Olson; Peter Lichtner; Maureen McGraw; Terry Cherry; Guy Roemer

    2002-09-01

    Recent field studies have led to the discovery of trace quantities of plutonium originating from the BENHAM underground nuclear test in two groundwater observation wells on Pahute Mesa at the Nevada Test Site. These observation wells are located 1.3 km from the BENHAM underground nuclear test and approximately 300 m from the TYBO underground nuclear test. In addition to plutonium, several other conservative (e.g. tritium) and reactive (e.g. cesium) radionuclides were found in both observation wells. The highest radionuclide concentrations were found in a well sampling a welded tuff aquifer more than 500m above the BENHAM emplacement depth. These measurements have prompted additional investigations to ascertain the mechanisms, processes, and conditions affecting subsurface radionuclide transport in Pahute Mesa groundwater. This report describes an integrated modeling approach used to simulate groundwater flow, radionuclide source release, and radionuclide transport near the BENHAM and TYBO underground nuclear tests on Pahute Mesa. The components of the model include a flow model at a scale large enough to encompass many wells for calibration, a source-term model capable of predicting radionuclide releases to aquifers following complex processes associated with nonisothermal flow and glass dissolution, and site-scale transport models that consider migration of solutes and colloids in fractured volcanic rock. Although multiple modeling components contribute to the methodology presented in this report, they are coupled and yield results consistent with laboratory and field observations. Additionally, sensitivity analyses are conducted to provide insight into the relative importance of uncertainty ranges in the transport parameters.

  2. Analysis of metolachlor ethane sulfonic acid (MESA) chirality in groundwater: A tool for dating groundwater movement in agricultural settings.

    Science.gov (United States)

    Rice, Clifford P; McCarty, Gregory W; Bialek-Kalinski, Krystyna; Zabetakis, Kara; Torrents, Alba; Hapeman, Cathleen J

    2016-08-01

    To better address how much groundwater contributes to the loadings of pollutants from agriculture we developed a specific dating tool for groundwater residence times. This tool is based on metolachlor ethane sulfonic acid, which is a major soil metabolite of metolachlor. The chiral forms of metolachlor ethane sulfonic acid (MESA) and the chiral forms of metolachlor were examined over a 6-year period in samples of groundwater and water from a groundwater-fed stream in a riparian buffer zone. This buffer zone bordered cropland receiving annual treatments with metolachlor. Racemic (rac) metolachlor was applied for two years in the neighboring field, and subsequently S-metolachlor was used which is enriched by 88% with the S-enantiomer. Chiral analyses of the samples showed an exponential increase in abundance of the S-enantiomeric forms for MESA as a function of time for both the first order riparian buffer stream (R(2)=0.80) and for groundwater within the riparian buffer (R(2)=0.96). However, the S-enrichment values for metolachlor were consistently high indicating different delivery mechanisms for MESA and metolachlor. A mean residence time of 3.8years was determined for depletion of the initially-applied rac-metolachlor. This approach could be useful in dating groundwater and determining the effectiveness of conservation measures. A mean residence time of 3.8years was calculated for groundwater feeding a first-order stream by plotting the timed-decay for the R-enantiomer of metolachlor ethane sulfonic acid. Published by Elsevier B.V.

  3. Seasonal Variations in Relative Weight of Lake Trout (Salvelinus namaycush), Kokanee Salmon (Oncorhynchus nerka), Rainbow Trout (Onocorhynchus mykiss), and Brown Trout (Salmo trutta) in Blue Mesa Reservoir, Colorado

    OpenAIRE

    Midas, Madeline; Williams, Asia; Cooper, Cindy; Courtney, Michael

    2013-01-01

    Blue Mesa Reservoir is the largest body of water in Colorado and is located on the western slope of the Rocky Mountains at an elevation of 7520 feet. Blue Mesa Reservoir contains recreationally important populations of lake trout (Salvelinus namaycush), kokanee salmon (Oncorhynchus nerka), rainbow trout (Onocorhynchus mykiss), and brown trout (Salmo trutta). A management challenge in recent years has been the overpopulation of lake trout, which has led to a steep decline in abundance of kokan...

  4. Metamorphic Rock-Hosted Orogenic Gold Deposit Type as a Source of Langkowala Placer Gold, Bombana, Southeast Sulawesi

    Directory of Open Access Journals (Sweden)

    Arifudin Idrus

    2014-06-01

    Full Text Available DOI: 10.17014/ijog.v6i1.114In 2008, placer gold was discovered in Langkowala area (Bombana Regency, Southeast Sulawesi, Indonesia, and more than 60,000 traditional gold miners in the early 2009 have been operating by digging vertical pits and panning active stream sediments. The grade of placer gold ranges from 50 to 140 g/t. Local geological framework indicates that the placer gold is not related to volcanic rock-related hydrothermal gold deposit, e.g. epithermal, skarn or porphyry. This paper describes a preliminary study on possible primary deposit type as a source of the Langkowala (Bombana secondary placer gold. A field study indicates that the Langkowala (Bombana placer/paleoplacer gold is possibly related to gold-bearing quartz veins/veinlets hosted by metamorphic rocks particularly mica schist and metasediments in the area. These quartz veins/veinlets are currently recognized in metamorphic rocks at Wumbubangka Mountains, a northern flank of Rumbia Mountain Range. Sheared, segmented quartz veins/veinlets are of 2 cm to 2 m in width and contain gold in a grade varying between 2 and 61 g/t. At least, there are two generations of the quartz veins. The first generation of quartz vein is parallel to foliation of mica schist and metasediments with general orientation of N 300oE/60o; the second quartz vein generation crosscut the first quartz vein and the foliation of the wallrock. The first quartz veins are mostly sheared/deformed, brecciated, and occasionally sigmoidal, whereas the second quartz veins are relatively massive. The similar quartz veins/veinlets types are also probably present in Mendoke Mountain Range, in the northern side of Langkowala area. This primary gold deposit is called as ‘orogenic gold type’. The orogenic gold deposit could be a new target of gold exploration in Indonesia in the future.

  5. The chert workshop of Tozal de la Mesa (Alins del Monte, Huesca, Spain and its exploitation in historical times

    Directory of Open Access Journals (Sweden)

    Marta Sánchez de la Torre

    2016-09-01

    The first approach to contextualize the recovered materials of Tozal de la Mesa workshop area has allowed determining an exploitation of the Garumnian cherts that has lasted until the late nineteenth century according to some recovered products (e.g., pottery and to oral sources.

  6. El origen de la Mesa Maestral en la Orden de San

    Directory of Open Access Journals (Sweden)

    Manuel López Fernández

    2009-01-01

    Full Text Available En las páginas siguientes tratamos de analizar las circunstancias que originaron el nacimiento de la Mesa Maestral en la Orden de Santiago, así como las consecuencias inmediatas que la aparición de este organismo económico –fuente exclusiva de rentas para los maestres— tuvo en dicha Orden. El análisis lo hacemos apoyándonos en el documento correspondiente al Capítulo General donde se estableció un nuevo rumbo para el reparto de los bienes temporales de la institución santiaguista. A pesar de que dicho documento está sin datar, nuestra opinión es que corresponde al Capítulo General de 1271 y que la Mesa Maestral surgió en el seno de la Orden de Santiago como consecuencia de la presión que los comendadores ejercieron sobre el maestre Pelay Pérez Correa en los años finales de su vida.In the following pages we try to analyze the circumstances that led to the birth of the Masters Bureau in the Order of Santiago, as well as the immediate effects that the birth of this economic body, exclusive source of revenue for the Masters, was in that Order. The analysis we do to build on the document for the General Chapter, which set a new course for the temporary sharing out of property in the santiaguista. institution Although the document is not dated, our view is that belongs to the General Chapter of 1271 and that the Masters Bureau arose within the Order of Santiago as a result of the pressure exerted by the Knight commanders on the grand master Pelayo Perez Correa in the final years of his life.

  7. Cripple Creek and other alkaline-related gold deposits in the Southern Rocky Mountains, USA: Influence of regional tectonics

    Science.gov (United States)

    Kelley, K.D.; Ludington, S.

    2002-01-01

    Alkaline-related epithermal vein, breccia, disseminated, skarn, and porphyry gold deposits form a belt in the southern Rocky Mountains along the eastern edge of the North American Cordillera. Alkaline igneous rocks and associated hydrothermal deposits formed at two times. The first was during the Laramide orogeny (about 70-40 Ma), with deposits restricted spatially to the Colorado mineral belt (CMB). Other alkaline igneous rocks and associated gold deposits formed later, during the transition from a compressional to an extensional regime (about 35-27 Ma). These younger rocks and associated deposits are more widespread, following the Rocky Mountain front southward, from Cripple Creek in Colorado through New Mexico. All of these deposits are on the eastern margin of the Cordillera, with voluminous calc-alkaline rocks to the west. The largest deposits in the belt include Cripple Creek and those in the CMB. The most important factor in the formation of all of the gold deposits was the near-surface emplacement of relatively oxidized volatile-rich alkaline magmas. Strontium and lead isotope compositions suggest that the source of the magmas was subduction-modified subcontinental lithosphere. However, Cripple Creek alkaline rocks and older Laramide alkaline rocks in the CMB that were emplaced through hydrously altered LREE-enriched rocks of the Colorado (Yavapai) province have 208Pb/204Pb ratios that suggest these magmas assimilated and mixed with significant amounts of lower crust. The anomalously hot, thick, and light crust beneath Colorado may have been a catalyst for large-scale transfer of volatiles and crustal melting. Increased dissolved H2O (and CO2, F, Cl) of these magmas may have resulted in more productive gold deposits due to more efficient magmatic-hydrothermal systems. High volatile contents may also have promoted Te and V enrichment, explaining the presence of fluorite, roscoelite (vanadium-rich mica) and tellurides in the CMB deposits and Cripple Creek as

  8. A Hydrostrat Model and Alternatives for Groundwater Flow and Contaminant Transport Model of Corrective Action Unit 99: Rainer Mesa-Shoshone Mountain, Nye County, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    NSTec Geotechnical Sciences Group

    2007-03-01

    The three-dimensional hydrostratigraphic framework model for the Rainier Mesa-Shoshone Mountain Corrective Action Unit was completed in Fiscal Year 2006. The model extends from eastern Pahute Mesa in the north to Mid Valley in the south and centers on the former nuclear testing areas at Rainier Mesa, Aqueduct Mesa, and Shoshone Mountain. The model area also includes an overlap with the existing Underground Test Area Corrective Action Unit models for Yucca Flat and Pahute Mesa. The model area is geologically diverse and includes un-extended yet highly deformed Paleozoic terrain and high volcanic mesas between the Yucca Flat extensional basin on the east and caldera complexes of the Southwestern Nevada Volcanic Field on the west. The area also includes a hydrologic divide between two groundwater sub-basins of the Death Valley regional flow system. A diverse set of geological and geophysical data collected over the past 50 years was used to develop a structural model and hydrostratigraphic system for the model area. Three deep characterization wells, a magnetotelluric survey, and reprocessed gravity data were acquired specifically for this modeling initiative. These data and associated interpretive products were integrated using EarthVision{reg_sign} software to develop the three-dimensional hydrostratigraphic framework model. Crucial steps in the model building process included establishing a fault model, developing a hydrostratigraphic scheme, compiling a drill-hole database, and constructing detailed geologic and hydrostratigraphic cross sections and subsurface maps. The more than 100 stratigraphic units in the model area were grouped into 43 hydrostratigraphic units based on each unit's propensity toward aquifer or aquitard characteristics. The authors organized the volcanic units in the model area into 35 hydrostratigraphic units that include 16 aquifers, 12 confining units, 2 composite units (a mixture of aquifer and confining units), and 5 intrusive

  9. Sociodemographic Correlates of Cognition in the Multi-Ethnic Study of Atherosclerosis (MESA).

    Science.gov (United States)

    Fitzpatrick, Annette L; Rapp, Stephen R; Luchsinger, José; Hill-Briggs, Felicia; Alonso, Alvaro; Gottesman, Rebecca; Lee, Hochang; Carnethon, Mercedes; Liu, Kiang; Williams, Kayleen; Sharrett, A Richey; Frazier-Wood, Alexis; Lyketsos, Constantine; Seeman, Teresa

    2015-07-01

    To describe the methodology utilized to evaluate cognitive function in the Multi-Ethnic Study of Atherosclerosis (MESA) and to present preliminary results by age, sex, and race/ethnicity. Cross-sectional measurements of a prospective observational cohort. Residents of 6 U.S. communities free of cardiovascular disease at baseline (2000-02). 4,591 adults who completed the fifth MESA clinical examination in 2011-12; mean age 70.3 (SD: 9.5) years, 53.1% women, 40.7% non-Hispanic white, 26.4% non-Hispanic black, 21.4% Hispanic, and 11.5% Chinese. The cognitive battery consisted of the Cognitive Abilities Screening Instrument (version 2) to evaluate global cognition, the Digit Symbol Code for processing speed and Digit Spans Forward and Backward to assess memory. Demographic, socioeconomic, and cultural covariates were also collected for descriptive statistics and multivariate modeling. Associations between socioeconomic factors and cognition revealed that age, race/ethnicity, education, occupational status, household income, health insurance type, household size, place of birth, years and generation in U.S., and the presence of the ApoE4 allele were significantly associated with performance on the cognitive tests, although patterns varied by specific test, racial/ethnicity, and sociocultural factors. As many of the influencing cultural and socioeconomic factors measured here are complex, multifactorial, and may not be adequately quantified, caution has been recommended with regard to comparison and interpretation of racial/ethnic group performance differences from these cross-sectional models. These data provide a baseline for future exams and more comprehensive longitudinal analyses of the contributions of subclinical and clinical diseases to cognitive function and decline. Copyright © 2015 American Association for Geriatric Psychiatry. Published by Elsevier Inc. All rights reserved.

  10. Sociodemographic Correlates of Cognition in the Multi-Ethnic Study of Atherosclerosis (MESA)

    Science.gov (United States)

    Fitzpatrick, Annette L.; Rapp, Stephen R.; Luchsinger, Jose; Hill-Briggs, Felicia; Alonso, Alvaro; Gottesman, Rebecca; Lee, Hochang; Carnethon, Mercedes; Liu, Kiang; Williams, Kayleen; Sharrett, A. Richey.; Frazier-Wood, Alexis; Lyketsos, Constantine; Seeman, Teresa

    2015-01-01

    Objectives To describe the methodology utilized to evaluate cognitive function in the Multi-Ethnic Study of Atherosclerosis (MESA) and to present preliminary results by age, gender and race/ethnicity. Design Cross-sectional measurements of a prospective observational cohort. Setting Residents of 6 US communities free of cardiovascular disease at baseline (2000-02). Participants 4,591 adults who completed the 5th MESA clinical examination in 2011-12, mean age 70.3 (SD 9.5) years, 53.1% women, and 40.7% Non-Hispanic White, 26.4% Non-Hispanic Black, 21.4% Hispanic, and 11.5% Chinese. Measurements The cognitive battery consisted of the Cognitive Abilities Screening Instrument (version 2) to evaluate global cognition, the Digit Symbol Code for processing speed and Digit Spans Forward and Backward to assess memory. Demographic, socioeconomic, and cultural covariates were also collected for descriptive statistics and multivariate modeling. Results Associations between socio-economic factors and cognition revealed that age, race/ethnicity, education, occupational status, household income, health insurance type, household size, place of birth, years and generation in U.S., and the presence of the APOE4 allele were significantly associated with performance on the cognitive tests although patterns varied by specific test, racial/ethnicity, and socio-cultural factors. Conclusions As many of the influencing cultural and socioeconomic factors measured here are complex, multifactorial, and may not be adequately quantified, caution has been recommended with regard to comparison and interpretation of racial/ethnic group performance differences from these cross-sectional models. These data provide a baseline for future exams and more comprehensive longitudinal analyses of the contributions of subclinical and clinical diseases to cognitive function and decline. PMID:25704999

  11. Study of molecular-beam epitaxy growth on patterned GaAs (311)A substrates with different mesa height

    NARCIS (Netherlands)

    Gong, Q.; Nötzel, R.; Schönherr, H.-P.; Ploog, K.

    2000-01-01

    We report on the evolution of the growth front during molecular-beam epitaxy on GaAs (3 1 1)A substrates stripe patterned along the [ ] direction as a function of the mesa height. During growth (1 0 0) and (2 1 1)A facets are formed and expand at the corners near the two opposite lying ( )A and (1 1

  12. 75 FR 19422 - Notice of Closure of Airport Mesa/Carizzo Creek Shooting Area in Eastern San Diego County, CA

    Science.gov (United States)

    2010-04-14

    ... DEPARTMENT OF THE INTERIOR Bureau of Land Management [CACA 47740, LLCAD07000 L51030000] Notice of Closure of Airport Mesa/Carizzo Creek Shooting Area in Eastern San Diego County, CA AGENCY: Bureau of Land Management, Interior. ACTION: Notice of temporary closure. SUMMARY: The Bureau of Land Management (BLM) has...

  13. Cutoff-mesa isolated rib optical waveguide for III-V heterostructure photonic integrated circuits

    Science.gov (United States)

    Vawter, G.A.; Smith, R.E.

    1998-04-28

    A cutoff mesa rib waveguide provides single-mode performance regardless of any deep etches that might be used for electrical isolation between integrated electrooptic devices. Utilizing a principle of a cutoff slab waveguide with an asymmetrical refractive index profile, single mode operation is achievable with a wide range of rib widths and does not require demanding etch depth tolerances. This new waveguide design eliminates reflection effects, or self-interference, commonly seen when conventional rib waveguides are combined with deep isolation etches and thereby reduces high order mode propagation and crosstalk compared to the conventional rib waveguides. 7 figs.

  14. Relationship of metabolic syndrome with incident aortic valve calcium and aortic valve calcium progression: the Multi-Ethnic Study of Atherosclerosis (MESA).

    Science.gov (United States)

    Katz, Ronit; Budoff, Matthew J; Takasu, Junichiro; Shavelle, David M; Bertoni, Alain; Blumenthal, Roger S; Ouyang, Pamela; Wong, Nathan D; O'Brien, Kevin D

    2009-04-01

    Metabolic syndrome (MetS) has been associated with increased prevalence of aortic valve calcium (AVC) and with increased progression of aortic stenosis. The purpose of this study was to determine whether MetS is associated with increased risks for the development of new ("incident") AVC or for progression of established AVC as assessed by CT. The relationships of MetS or its components as well as of diabetes to risks for incident AVC or AVC progression were studied among participants with CT scans performed at baseline and at either year 2 or year 3 examinations in the Multi-Ethnic Study of Atherosclerosis (MESA). Of 5,723 MESA participants meeting criteria for inclusion, 1,674 had MetS by Adult Treatment Panel III criteria, whereas 761 had diabetes. Among the 5,123 participants without baseline AVC, risks for incident AVC, adjusted for time between scans, age, sex, race/ethnicity, LDL cholesterol, lipid-lowering medications, and smoking, were increased significantly for MetS (odds ratio [OR] 1.67 [95% CI 1.21-2.31]) or diabetes (2.06 [1.39-3.06]). In addition, there was an increase in incident AVC risk with increasing number of MetS components. Similar results were found using the International Diabetes Federation MetS criteria. Among the 600 participants (10.5%) with baseline AVC, neither MetS nor diabetes was associated with AVC progression. In the MESA cohort, MetS was associated with a significant increase in incident ("new") AVC, raising the possibility that MetS may be a potential therapeutic target to prevent AVC development.

  15. Remote-sensing data processing with the multivariate regression analysis method for iron mineral resource potential mapping: a case study in the Sarvian area, central Iran

    Science.gov (United States)

    Mansouri, Edris; Feizi, Faranak; Jafari Rad, Alireza; Arian, Mehran

    2018-03-01

    This paper uses multivariate regression to create a mathematical model for iron skarn exploration in the Sarvian area, central Iran, using multivariate regression for mineral prospectivity mapping (MPM). The main target of this paper is to apply multivariate regression analysis (as an MPM method) to map iron outcrops in the northeastern part of the study area in order to discover new iron deposits in other parts of the study area. Two types of multivariate regression models using two linear equations were employed to discover new mineral deposits. This method is one of the reliable methods for processing satellite images. ASTER satellite images (14 bands) were used as unique independent variables (UIVs), and iron outcrops were mapped as dependent variables for MPM. According to the results of the probability value (p value), coefficient of determination value (R2) and adjusted determination coefficient (Radj2), the second regression model (which consistent of multiple UIVs) fitted better than other models. The accuracy of the model was confirmed by iron outcrops map and geological observation. Based on field observation, iron mineralization occurs at the contact of limestone and intrusive rocks (skarn type).

  16. The timing and origin of pre- and post-caldera volcanism associated with the Mesa Falls Tuff, Yellowstone Plateau volcanic field

    Science.gov (United States)

    Stelten, Mark E.; Champion, Duane E.; Kuntz, Mel A.

    2018-01-01

    We present new sanidine 40Ar/39Ar ages and paleomagnetic data for pre- and post-caldera rhyolites from the second volcanic cycle of the Yellowstone Plateau volcanic field, which culminated in the caldera-forming eruption of the Mesa Falls Tuff at ca. 1.3 Ma. These data allow for a detailed reconstruction of the eruptive history of the second volcanic cycle and provide new insights into the petrogenesis of rhyolite domes and flows erupted during this time period. 40Ar/39Ar age data for the biotite-bearing Bishop Mountain flow demonstrate that it erupted approximately 150 kyr prior to the Mesa Falls Tuff. Integrating 40Ar/39Ar ages and paleomagnetic data for the post-caldera Island Park rhyolite domes suggests that these five crystal-rich rhyolites erupted over a centuries-long time interval at 1.2905 ± 0.0020 Ma (2σ). The biotite-bearing Moonshine Mountain rhyolite dome was originally thought to be the downfaulted vent dome for the pre-caldera Bishop Mountain flow due to their similar petrographic and oxygen isotope characteristics, but new 40Ar/39Ar dating suggest that it erupted near contemporaneously with the Island Park rhyolite domes at 1.2931 ± 0.0018 Ma (2σ) and is a post-caldera eruption. Despite their similar eruption ages, the Island Park rhyolite domes and the Moonshine Mountain dome are chemically and petrographically distinct and are not derived from the same source. Integrating these new data with field relations and existing geochemical data, we present a petrogenetic model for the formation of the post-Mesa Falls Tuff rhyolites. Renewed influx of basaltic and/or silicic recharge magma into the crust at 1.2905 ± 0.0020 Ma led to [1] the formation of the Island Park rhyolite domes from the source region that earlier produced the Mesa Falls Tuff and [2] the formation of Moonshine Mountain dome from the source region that earlier produced the biotite-bearing Bishop Mountain flow. These magmas were stored in the crust for less than a few thousand

  17. Armazenamento refrigerado da uva de mesa 'Romana' (A1105) cultivada sob cobertura plástica

    OpenAIRE

    Lulu, Jorge; Castro, Josalba V.; Pedro Júnior, Mário J.

    2005-01-01

    A videira é uma das principais fruteiras cultivadas em todo o mundo e atualmente a preferência por uvas do tipo "sem sementes" ou "apirênicas" vem aumentando gradativamente no mercado interno brasileiro. A cultivar 'Romana' (A1105) tem mostrado grande potencial como nova alternativa de uva de mesa apirênica na região de Jundiaí - SP. No entanto, a qualidade dos cachos tem sido afetada pela ocorrência de chuvas na época da colheita, propiciando a incidência de rachaduras nas bagas ("cracking")...

  18. Value of information analysis for Corrective Action Unit Nos. 101 and 102: Central and western Pahute Mesa, Nevada Test Site, Nevada

    International Nuclear Information System (INIS)

    1998-09-01

    The purpose of this report is to describe the basis for and present the results of a value of information analysis (VOIA) for the Pahute Mesa underground test area of the Nevada Test Site (NTS), one of several areas of the Nevada Test Site used for underground nuclear testing in the past. The value of information analysis was used to evaluate and compare potential characterization options at the Pahute Mesa underground test area for site remediation purposes. Thirty six characterization options were evaluated, ranging from a single, inexpensive study using existing data and intended to address a single question or uncertainty, to a forty-million-dollar suite of activities designed to collect and analyze new information to address multiple uncertainties. The characterization options were compared and ranked based on how effective the experts though the information collection would be in reducing uncertainties, how this effected the distance to contaminant boundary, and the cost of the option

  19. Landscape analyses of representativeness in the Serra de Mesa hydroelectric reservoir, Brazil

    International Nuclear Information System (INIS)

    Cavalcanti, R. B; Meneses, P. R.; Ahern, F. J.

    1997-01-01

    A lake of some 1784 sq km, consisting mostly of savanna vegetation, riverine forest, tropical dry forest and agricultural land, will be created by the construction of the Serra de Mesa hydroelectric reservoir in central Brazil. The lake will contain about 300 islands of various sizes. RADARSAT imagery and LANDSAT TM data is being used to analyze and assess the representativeness of the island and lake edge habitats in relation to the original mix of habitats prior to the flooding. The LANDSAT TM data will provide complementarity, with RADARSAT coverage showing the relief and TM coverage documenting the vegetation classes. In the next phase of the project field data on the biological communities of the islands will be correlated with the landscape classification by remote sensing

  20. Geohydrology and effects of water use in the Black Mesa area, Navajo and Hopi Indian Reservations, Arizona

    Science.gov (United States)

    Eychaner, James H.

    1983-01-01

    The N aquifer is the main source of water in the 5,400-square-mile Black Mesa area in the Navajo and Hopi Indian Reservations in northeastern Arizona. The N aquifer consists of the Navajo Sandstone and parts of the underlying Kayenta Formation and Wingate Sandstone of Jurassic and Triassic age. Maximum saturated thickness of the aquifer is about 1,050 feet in the northwestern part of the area, and the aquifer thins to extinction to the southeast. Water is under confined conditions in the central 3,300 square miles of the area. To the east, north, and west of Black Mesa, the aquifer is exposed at the surface, and water is unconfined. The aquifer was in equilibrium before about 1965. Recharge of about 13,000 acre-feet per year was balanced primarily by discharge near Moenkopi Wash and Laguna Creek and by evapotranspiration. At least 180 million acre-feet of water was in storage. The estimated average hydraulic conductivity of the aquifer is 0.65 foot per day. The confined storage coefficient is estimated to be about 0.0004 where the aquifer is thickest, and the estimated unconfined storage coefficient ranges from 0.10 to 0.15. Ground-water withdrawals that averaged 5,300 acre-feet per year from 1976 to 1979 have caused water levels to decline in wells in the confined part of the aquifer. Withdrawals include an average of 3,700 acre-feet per year to supply a coal-slurry pipeline from a coal mine on Black Mesa. Six observation wells equipped with water-level recorders have been used to monitor aquifer response. The water level in one well 32 miles south of the mine declined 17 feet from 1972 through 1979 and 3.5 feet during 1979. A mathematical model of the N aquifer was developed and calibrated for equilibrium and nonequilibrium conditions. The model was used in part to improve estimates of aquifer characteristics and the water budget, and it successfully reproduced the observed response of the aquifer through 1979. The model results indicate that about 95 percent of

  1. Geochronology and Genesis of the Xitian W-Sn Polymetallic Deposit in Eastern Hunan Province, South China: Evidence from Zircon U-Pb and Muscovite Ar-Ar Dating, Petrochemistry, and Wolframite Sr-Nd-Pb Isotopes

    Directory of Open Access Journals (Sweden)

    Jingya Cao

    2018-03-01

    Full Text Available The recently explored Xitian tungsten-tin (W-Sn polymetallic ore field, located in Hunan province, South China, is one of the largest ore fields in the Nanling Range (NLR. Two major metallogenic types appeared in this ore field, skarn- and quartz vein-type. They are distributed within Longshang, Heshuxia, Shaiheling, Hejiangkou, Goudalan, and so on. Hydrothermal zircons from two altered granites yielded U-Pb ages of 152.8 ± 1.1 Ma, and 226.0 ± 2.8 Ma, respectively. Two muscovite samples from ore-bearing quartz vein yielded 40Ar/39Ar plateau ages of 156.6 ± 0.7 Ma, 149.5 ± 0.8 Ma, respectively. Combined with the geological evidence, two metallogenic events are proposed in the Xitian ore field, with skarn-type W-Sn mineralization in Late Triassic (Indosinian and quartz vein/greisen type W-Sn mineralization in Late Jurassic (Yanshanian. The relatively low Ce/Ce* ratios and high Y/Ho ratios in zircons from two altered granites indicate that the hydrothermal fluids of two metallogenic events are characterized by low oxygen fugacities and enrichment in F. The similar chondrite-normalized patterns between the skarn and Xitian Indosinian granites and Sr-Nd-Pb isotopic compositions of wolframite suggest that the metal sources for both types W-Sn mineralization are derived from a crustal source.

  2. MESA models for the evolutionary status of the epsilon Aurigae disk-eclipsed binary system

    Science.gov (United States)

    Stencel, Robert E.; Gibson, Justus

    2018-06-01

    The brightest member of the class of disk-eclipsed binary stars is the Algol-like long-period binary, epsilon Aurigae (HD 31964, F0Iap + disk, http://adsabs.harvard.edu/abs/2016SPIE.9907E..17S ). Using MESA (Modules for Experiments in Stellar Astrophysics, version 9575), we have made an evaluation of its evolutionary state. We sought to satisfy several observational constraints, including: (1) requiring evolutionary tracks to pass close to the current temperature and luminosity of the primary star; (2) obtaining a period near the observed value of 27.1 years; (3) matching a mass function of 3.0; (4) concurrent Roche lobe overflow and mass transfer; (5) an isotopic ratio 12C / 13C = 5 and, (6) matching the interferometrically determined angular diameter. A MESA model starting with binary masses of 9.85 + 4.5 solar masses, with a 100 day initial period, produces a 1.2 + 10.6 solar masses result having a 547 day period, plus a single digit 12C / 13C ratio. These values were reached near an age of 20 Myr, when the donor star comes close to the observed luminosity and temperature for epsilon Aurigae A, as a post-RGB/pre-AGB star. Contemporaneously, the accretor then appears as an upper main sequence, early B-type star. This benchmark model can provide a basis for further exploration of this interacting binary, and other long period binary stars. This report has been submitted to MNRAS, along with a parallel investigation of mass transfer stream and disk sub-structure. The authors are grateful to the estate of William Herschel Womble for the support of astronomy at the University of Denver.

  3. Diseño y construcción de una mesa concentradora para la optimización del proceso de extracción de Oro en una empresa minera de Zaruma.

    OpenAIRE

    Aguilar Asanza, Mayra Fernanda; Corella Merizalde, Javier Oswaldo

    2016-01-01

    Este proyecto trata sobre el diseño y construcción de una mesa concentradora usando una tecnología limpia para la optimización del proceso de extracción de Oro, para una Planta de Beneficio de metales de la ciudad de Zaruma.Este diseño se basa en una mesa que mediante la vibración o movimiento, separa partículas minerales micrométricas de diferente peso específico, este proceso no utiliza ningún reactivo químico contaminante para el medio ambiente, solo necesita agua (H2o), el cual puede ser ...

  4. A process to estimate net infiltration using a site-scale water-budget approach, Rainier Mesa, Nevada National Security Site, Nevada, 2002–05

    Science.gov (United States)

    Smith, David W.; Moreo, Michael T.; Garcia, C. Amanda; Halford, Keith J.; Fenelon, Joseph M.

    2017-08-29

    This report documents a process used to estimate net infiltration from precipitation, evapotranspiration (ET), and soil data acquired at two sites on Rainier Mesa. Rainier Mesa is a groundwater recharge area within the Nevada National Security Site where recharged water flows through bedrock fractures to a deep (450 meters) water table. The U.S. Geological Survey operated two ET stations on Rainier Mesa from 2002 to 2005 at sites characterized by pinyon-juniper and scrub-brush vegetative cover. Precipitation and ET data were corrected to remove measurement biases and gap-filled to develop continuous datasets. Net infiltration (percolation below the root zone) and changes in root-zone water storage were estimated using a monthly water-balance model.Site-scale water-budget results indicate that the heavily-fractured welded-tuff bedrock underlying thin (water source for vegetation during dry periods. Annual precipitation during the study period ranged from fourth lowest (182 millimeters [mm]) to second highest (708 mm) on record (record = 55 years). Annual ET exceeded precipitation during dry years, indicating that the fractured-bedrock reservoir capacity is sufficient to meet atmospheric-evaporative demands and to sustain vegetation through extended dry periods. Net infiltration (82 mm) was simulated during the wet year after the reservoir was rapidly filled to capacity. These results support previous conclusions that preferential fracture flow was induced, resulting in an episodic recharge pulse that was detected in nearby monitoring wells. The occurrence of net infiltration only during the wet year is consistent with detections of water-level rises in nearby monitoring wells that occur only following wet years.

  5. Water resources of the Santa Ysabel and Mesa Grande Indian Reservations, San Diego County, California

    Science.gov (United States)

    Freckleton, John R.

    1981-01-01

    The Santa Ysabel (consisting of three tracts) and Mesa Grande Indian Reservations are in north-central San Diego County, Calif. On both reservations fractured and weathered igneous and metamorphic rocks and alluvium are water bearing; however, no wells are known to derive their water entirely from alluvium. Well yields range from 2.5 to 250 gallons per minute. Springs occur where saturated fractured or weathered material intersects the land surface. Spring discharge ranged from 0 gallon per minute (November 1979) to 9.4 gallons per minute (November 1979). Few data are available for the surface water characteristics of the study area. One-time measurements of discharge at selected stream sites were made in late November 1979 and late May 1980; discharges ranged from less than 0.01 cubic foot per second to an estimated 3 cubic feet per second. Further study of the surface-water systems would provide a basis for estimating their development potential. The existing water-supply development on the Santa Ysabel Indian Reservation is adequate for the present residents. The Mesa Grande reservation was unoccupied in 1952, was reportedly unoccupied in November 1979, and has no developed water supply. Additional water can be developed for both reservations from the igneous and metamorphic rock, from presently undeveloped springs, and from perennial reaches of the larger streams. Except for excessive iron and sodium at some ground-water sites and excessive sodium at a few surface-water sites, the water is of suitable quality for domestic and agricultural use. (USGS)

  6. An Investigation of Amphitheater-Headed Canyon Distribution, Morphology Variation, and Longitudinal Profile Controls in Escalante and Tarantula Mesa, Utah.

    Science.gov (United States)

    Ryan, A. J.; Whipple, K. X.

    2014-12-01

    Amphitheater-headed canyons are primarily distinguished from typical fluvial channels by their abrupt headwall terminations. A key goal in the study of river canyons is to establish a reliable link between form and formation processes. This is of particular significance for Mars, where, if such links can be established, amphitheater-headed canyons could be used to determine ancient erosion mechanisms and, by inference, climate conditions. Type examples in arid regions on Earth, such as in Escalante River, Utah, previously have been interpreted as products of groundwater seepage erosion. We investigate amphitheater-headed canyons in Escalante and Tarantula Mesa where variations in canyon head morphology may hold clues for the relative roles of rock properties and fluvial and groundwater processes. In lower Escalante, amphitheaters are only present where canyons have breached the Navajo Sandstone - Kayenta Formation contact. In some canyons, amphitheater development appears to have been inhibited by an abundance of coarse bedload. In Tarantula Mesa, canyons have a variety of headwalls, from amphitheaters to stepped knickzones. Headwall morphology distribution is directly related to the spatially variable presence of knickpoint-forming, fine-grained interbeds within cliff-forming sandstones. Amphitheaters only form where the sandstone unit is undisrupted by these interbeds. Finally, most canyons in Escalante and Tarantula Mesa, regardless of substrate lithology, amphitheater presence, or groundwater spring intensity, are well described by a slope-area power law relationship with regionally constant concavity and normalized steepness indices. This suggests that all channels here are subject to the same erosion rates, independent of groundwater weathering intensity. Thus: 1) variations in canyon headwall form do not necessary relate to differences in fluvial history, 2) stratigraphic variations are clearly of importance in sedimentary canyon systems, and 3) although

  7. Assessing the risk of nitrogen deposition to natural resources in the Four Corners area

    Science.gov (United States)

    Reed, Sasha C.; Belnap, Jayne; Floyd-Hanna, Lisa; Crews, Tim; Herring, Jack; Hanna, Dave; Miller, Mark E.; Duniway, Michael C.; Roybal, Carla M.

    2013-01-01

    Nitrogen (N) deposition in the western U.S. is on the rise and is already dramatically affecting terrestrial ecosystems. For example, N deposition has repeatedly been shown to lower air and water quality, increase greenhouse gas emissions, alter plant community composition, and significantly modify fire regimes. Accordingly, the effects of N deposition represent one of our largest environmental challenges and make difficult the National Park Service’s (NPS) important mission to “preserve the scenery and the natural and historic objects and the wildlife… unimpaired for the enjoyment of future generations”. Due to increased population growth and energy development (e.g., natural gas wells), the Four Corners region has become a notable ‘hotspot’ for N deposition. However, our understanding of how increased N deposition will affect these unique ecosystems, as well as how much deposition is actually occurring, remains notably poor. Here we used a multi-disciplinary approach to gathering information in an effort to help NPS safeguard the Four Corners national parks, both now and into the future. We applied modeling, field, and laboratory techniques to clarify current N deposition gradients and to help elucidate the ecosystem consequences of N deposition to the national parks of the Four Corners area. Our results suggest that NOx deposition does indeed represent a significant source of N to Mesa Verde National Park and, as expected, N deposition significantly affects coupled biogeochemical cycling (N, carbon, and phosphorus) of these landscapes. We also found some surprising results. For example, perhaps due to the low nutrient availability in these (and other) dryland ecosystems, although most other research suggests that adding N reduces N fixation rates, N additions did not consistently reduce natural N inputs via biological N2 fixation at our dryland sites. While the timeline of this pilot project is too brief to elucidate all the potential insight from

  8. Regional stratigraphy, sedimentology, and tectonic significance of Oligocene-Miocene sedimentary and volcanic rocks, northern Baja California, Mexico

    Science.gov (United States)

    Dorsey, Rebecca J.; Burns, Beverly

    1994-01-01

    Upper Oligocene (?) to middle Miocene sedimentary and volcanic rocks in northern Baja California were deposited along the western margin of North America during subduction of the Guadalupe plate and southward migration of the Rivera Triple Junction. Regional mapping and compilation of stratigraphic data reveal a sequence of three regionally traceable stratigraphic units. (1) Oligocene (?) to lower Miocene Mesa Formation: basal quartz-rich fluvial sandstone, grus, conglomerate, and accessory facies, whose detrital compositions reflect the composition of local pre-Tertiary basement rock. (2) Lower to middle Miocene Comondú Formation: laterally variable sequence of volcaniclastic conglomerate, breccia, sandstone, tuff and minor volcanic flow units. (3) Widespread mesa-capping rhyolite tuff, typically welded and crystal-rich, probably upper Miocene in age. The Mesa Formation overlies a highly irregular and deeply dissected erosional surface developed on pre-Tertiary basement rock. The shift from pre-Mesa erosion to widespread (though localized) deposition and valley-filling records the final phase of late Cretaceous to middle Tertiary regional subsidence and eastward transgression that resulted from slow cooling and thermal contraction of Cretaceous arc crust during a temporal gap in magmatic activity along the western Cordilleran margin. Nonmarine sediments of the Mesa Formation were deposited in small, steep-walled paleovalleys and basins that gradually filled and evolved to form through-going, low-energy ephemeral stream systems. The gradational upward transition from the Mesa to Comondú Formation records the early to middle Miocene onset of subduction-related arc magmatism in eastern Baja California and related westward progradation of alluvial volcaniclastic aprons shed from high-standing eruptive volcanic centers. Pre-existing streams were choked with the new influx of volcanic detritus, causing the onset of rapid sediment deposition by stream flows and dilute

  9. Regional tectonics, geology, magma chamber processes and mineralisation of the Jinchuan nickel-copper-PGE deposit, Gansu Province, China: A review

    Directory of Open Access Journals (Sweden)

    T.M. (Mike Porter

    2016-05-01

    The Jinchuan ultramafic intrusion was injected into three interconnected sub-chambers, each containing a separate orebody. It essentially comprises an olivine-orthopyroxene-chromite cumulate, with interstitial orthopyroxene, clinopyroxene, plagioclase and phlogopite, and is predominantly composed of lherzolite (∼80%, with an outer rim of olivine pyroxenite and cores of mineralised dunite. Mineralisation occurs as disseminated and net-textured sulphides, predominantly within the dunite, with lesser, PGE rich lenses, late massive sulphide accumulations, small copper rich pods and limited mineralised diopside skarn in wall rock marbles. The principal ore minerals are pyrrhotite (the dominant sulphide, pentlandite, chalcopyrite, cubanite, mackinawite and pyrite, with a variety of platinum group minerals and minor gold. The deposit underwent significant post-magmatic tremolite-actinolite, chlorite, serpentine and magnetite alteration. The volume of the Jinchuan intrusion accounts for <3% of the total parental magma required to generate the contained olivine and sulphide. It is postulated that mafic melt, intruded into the lower crust, hydraulically supported by density contrast buoyancy from below the Moho, ponded in a large staging chamber, where crystallisation and settling formed a lower sulphide rich mush. This mush was subsequently injected into nearby shallow dipping faults to form the Jinchuan intrusion.

  10. The paramilitary speech Alias '39': suspects, offenders and redeemed in La Mesa, Cesar

    Directory of Open Access Journals (Sweden)

    José Gregorio Pérez V.

    2016-08-01

    Full Text Available The paper aims to characterize the paramilitary speech in the village of La Mesa, Cesar, whose practices of power-knowledge are not registered only in the coercive field, but extend to forms of communication, where the control and subjugation of the population, legitimation and de-legitimation of the main enemy (FARC and ELN, and suspects and the problematic resident (offenders, acquire a particular form of registration in the individualities and the social body, and extends to the soccer field, the school, the streets, the workplaces, the artifacts (stone and soccer arches present in the territory. In addition to suspects and offenders, the paramilitary leader, David Hernández Rojas, alias ‘39’, led to another subject registered in the speech, the redeemed/collaborators.

  11. Discrete Fracture Network Modeling and Simulation of Subsurface Transport for the Topopah Springs and Lava Flow Aquifers at Pahute Mesa, FY 15 Progress Report

    Energy Technology Data Exchange (ETDEWEB)

    Makedonska, Nataliia [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Kwicklis, Edward Michael [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Birdsell, Kay Hanson [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Harrod, Jeremy Ashcraft [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Karra, Satish [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-10-18

    This progress report for fiscal year 2015 (FY15) describes the development of discrete fracture network (DFN) models for Pahute Mesa. DFN models will be used to upscale parameters for simulations of subsurface flow and transport in fractured media in Pahute Mesa. The research focuses on modeling of groundwater flow and contaminant transport using DFNs generated according to fracture characteristics observed in the Topopah Spring Aquifer (TSA) and the Lava Flow Aquifer (LFA). This work will improve the representation of radionuclide transport processes in large-scale, regulatory-focused models with a view to reduce pessimistic bounding approximations and provide more realistic contaminant boundary calculations that can be used to describe the future extent of contaminated groundwater. Our goal is to refine a modeling approach that can translate parameters to larger-scale models that account for local-scale flow and transport processes, which tend to attenuate migration.

  12. Germanium geochemistry and mineralogy

    Science.gov (United States)

    Bernstein, L.R.

    1985-01-01

    Germanium is enriched in the following geologic environments: 1. (1) iron meteorites and terrestrial iron-nickel; 2. (2) sulfide ore deposits, particularly those hosted by sedimentary rocks; 3. (3) iron oxide deposits; 4. (4) oxidized zones of Ge-bearing sulfide deposits; 5. (5) pegmatites, greisens, and skarns; and 6. (6) coal and lignitized wood. In silicate melts, Ge is highly siderophile in the presence of native iron-nickel; otherwise, it is highly lithophile. Among silicate minerals, Ge is concentrated in those having less polymerized silicate tetrahedra such as olivine and topaz. In deposits formed from hydrothermal solutions, Ge tends to be enriched mostly in either sulfides or in fluorine-bearing phases; it is thus concentrated both in some hydrothermal sulfide deposits and in pegmatites, greisens, and skarns. In sulfide deposits that formed from solutions having low to moderate sulfur activity, Ge is concentrated in sphalerite in amounts up to 3000 ppm. Sulfide deposits that formed from solutions having higher sulfur activity allowed Ge to either form its own sulfides, particularly with Cu, or to substitute for As, Sn, or other metals in sulfosalts. The Ge in hydrothermal fluids probably derives from enrichment during the fractional crystallization of igneous fluids, or is due to the incorporation of Ge from the country rocks, particularly from those containing organic material. Germanium bonds to lignin-derivative organic compounds that are found in peat and lignite, accounting for its common concentration in coals and related organic material. Germanium is precipitated from water together with iron hydroxide, accounting for its concentration in some sedimentary and supergene iron oxide deposits. It also is able to substitute for Fe in magnetite in a variety of geologic environments. In the oxidized zone of Ge-bearing sulfide deposits, Ge is concentrated in oxides, hydroxides, and hydroxy-sulfates, sometimes forming its own minerals. It is particularly

  13. Draft environmental statement related to the Energy Fuels Nuclear, Inc., White Mesa Uranium Project (San Juan County, Utah)

    International Nuclear Information System (INIS)

    1978-12-01

    The proposed action is the issuance of a Source Material License to Energy Fuels Nuclear, Inc., for the construction and operation of the proposed White Mesa Uranium Project (Utah) with a product (U 3 O 8 ) production limited to 7.3 x 10 5 kg (1.6 x 10 6 lb) per year. Possible environmental impacts and adverse effects were identified. Conditions for the protection of the environment are set forth before the license can be issued

  14. Padrão de identidade e qualidade do tomate (Lycopersicon esculentum Mill. de mesa

    Directory of Open Access Journals (Sweden)

    Ferreira Sila Mary Rodrigues

    2004-01-01

    Full Text Available O valor comercial do tomate, Lycopersicon esculentum Mill., é definido pelas características de identidade e qualidade presentes no fruto que podem ser avaliadas pela classificação do produto. A presente revisão de literatura teve como objetivo descrever o padrão de identidade e qualidade do tomate de mesa, através da classificação. O tomate de mesa é classificado em grupos, subgrupos, classes e tipos. De acordo com o formato do fruto, o tomate é classificado em dois grupos: oblongo, quando o diâmetro longitudinal é maior que o transversal e redondo, quando o diâmetro longitudinal é menor ou igual ao transversal. Em função do estádio de maturação, o tomate é classificado em cinco subgrupos: verde maduro, pintado, rosado, vermelho e vermelho maduro. A classe é definida em função do maior diâmetro transversal do fruto em relação ao grupo a que pertença. O tomate oblongo é classificado em três classes: grande, médio e pequeno. O tomate redondo é classificado em quatro classes: gigante, grande, médio e pequeno. De acordo com os índices de ocorrência de defeitos graves e leves presentes nos frutos, o tomate é classificado também em tipo: extra, especial ou selecionado e comercial. São considerados defeitos graves: podridão, passado, queimado, dano por geada, podridão apical, e defeitos leves: dano, mancha, ocado, deformado e imaturo. A amostra de tomate que ultrapasse os índices de defeitos previstos pela legislação do Ministério da Agricultura é classificada como fora do padrão.

  15. Role of methyl salicylate on oviposition deterrence in Arabidopsis thaliana.

    Science.gov (United States)

    Groux, Raphaël; Hilfiker, Olivier; Gouhier-Darimont, Caroline; Peñaflor, Maria Fernanda Gomes Villalba; Erb, Matthias; Reymond, Philippe

    2014-07-01

    Plants attacked by herbivores have evolved different strategies that fend off their enemies. Insect eggs deposited on leaves have been shown to inhibit further oviposition through visual or chemical cues. In some plant species, the volatile methyl salicylate (MeSA) repels gravid insects but whether it plays the same role in the model species Arabidopsis thaliana is currently unknown. Here we showed that Pieris brassicae butterflies laid fewer eggs on Arabidopsis plants that were next to a MeSA dispenser or on plants with constitutively high MeSA emission than on control plants. Surprisingly, the MeSA biosynthesis mutant bsmt1-1 treated with egg extract was still repellent to butterflies when compared to untreated bsmt1-1. Moreover, the expression of BSMT1 was not enhanced by egg extract treatment but was induced by herbivory. Altogether, these results provide evidence that the deterring activity of eggs on gravid butterflies is independent of MeSA emission in Arabidopsis, and that MeSA might rather serve as a deterrent in plants challenged by feeding larvae.

  16. Groundwater Flow Model of Corrective Action Units 101 and 102: Central and Western Pahute Mesa, Nevada Test Site, Nye County, Nevada, Revision 0

    Energy Technology Data Exchange (ETDEWEB)

    Greg Ruskauff

    2006-06-01

    The Pahute Mesa groundwater flow model supports the FFACO UGTA corrective action strategy objective of providing an estimate of the vertical and horizontal extent of contaminant migration for each CAU in order to predict contaminant boundaries. A contaminant boundary is the model-predicted perimeter that defines the extent of radionuclide-contaminated groundwater from underground nuclear testing above background conditions exceeding Safe Drinking Water Act (SDWA) standards. The contaminant boundary will be composed of both a perimeter boundary and a lower hydrostratigraphic unit (HSU) boundary. Additional results showing contaminant concentrations and the location of the contaminant boundary at selected times will also be presented. These times may include the verification period, the end of the five-year proof-of-concept period, as well as other times that are of specific interest. The FFACO (1996) requires that the contaminant transport model predict the contaminant boundary at 1,000 years and “at a 95% level of confidence.” The Pahute Mesa Phase I flow model described in this report provides, through the flow fields derived from alternative hydrostratigraphic framework models (HFMs) and recharge models, one part of the data required to compute the contaminant boundary. Other components include the simplified source term model, which incorporates uncertainty and variability in the factors that control radionuclide release from an underground nuclear test (SNJV, 2004a), and the transport model with the concomitant parameter uncertainty as described in Shaw (2003). The uncertainty in all the above model components will be evaluated to produce the final contaminant boundary. This report documents the development of the groundwater flow model for the Central and Western Pahute Mesa CAUs.

  17. GEOLOGICAL FEATURES OF NEOGENE BASINS HOSTING BORATE DEPOSITS: AN OVERVIEW OF DEPOSITS AND FUTURE FORECAST, TURKEY

    Directory of Open Access Journals (Sweden)

    Cahit HELVACI

    2015-12-01

    hydroboracite are present in west Anatolia, Death Valley, California, and Sijes (Argentina. Quaternary borates are present in salars (Andes and playa- lakes and salt pans (USA-Tibet. Boron is a rare element in the Earth’s crust, but extraordinary concentrations can be found in limited places. The formation of borate deposits can be classified as follows: a skarn group associated with intrusives and consisting of silicates and iron oxides; a magnesium oxide group hosted by marine evaporitic sediments; and a sodium– and calcium–borate hydrates group associated with playa-lake sediments and explosive volcanic activity. Some conditions are essential for the formation of economically viable borate deposits in playa-lake volcano-sedimentary sequences: formation of playa-lake environment; concentration of boron in the playa lake, sourced from andesitic to rhyolitic volcanics, direct ash fall into the basin, or hydrothermal solutions along graben faults; thermal springs near the area of volcanism; arid to semi-arid climatic conditions; and lake water with a pH of between 8.5 and 11. A borate is defined as any compound that contains or supplies boric oxide (B2O3. A large number of minerals contain boric oxide, but the three that are most important from a worldwide commercial standpoint are borax, ulexite, and colemanite, which are produced in a limited number of countries. Turkey has the largest borax, ulexite and colemanite reserves in the world and all the world’s countries are dependent upon the colemanite and ulexite reserves of Turkey. Most of the world’s commercial borate deposits are mined by open pit methods. Brines from Searles Lake, and presumably the Chinese sources, are recovered by either controlled evaporation or carbonation. Boric acid is one of the final products produced from most of the processes. Further research on the mineralogy and chemistry of borate minerals and associated minerals will the production and utilization of borate end-products.

  18. Hydrologic Data for the Groundwater Flow and Contaminant Transport Model of Corrective Action Units 101 and 102: Central and Western Pahute Mesa, Nye County, Nevada, Revision 0

    Energy Technology Data Exchange (ETDEWEB)

    Drici, Warda [Stoller-Navarro Joint Venture, Las Vegas, NV (United States)

    2004-02-01

    This report documents the analysis of the available hydrologic data conducted in support of the development of a Corrective Action Unit (CAU) groundwater flow model for Central and Western Pahute Mesa: CAUs 101 and 102.

  19. Late-Hercynian intrusion-related gold deposits: An integrated model on the Tighza polymetallic district, central Morocco

    Science.gov (United States)

    Éric, Marcoux; Khadija, Nerci; Yannick, Branquet; Claire, Ramboz; Gilles, Ruffet; Jean-Jacques, Peucat; Ross, Stevenson; Michel, Jébrak

    2015-07-01

    Gold have been recently recognized in the Tighza (formerly Jebel Aouam) district, in the Hercynian belt of central Morocco. This district has long been known for its W mineralization, as well as major Pb-Ag-Zn, and minor Sb-Ba deposits, all geographically associated with late-Hercynian calc-alkaline magmatism. Gold mineralization in the district is mainly hosted by thick W-Au quartz veins located around the "Mine granite" small granitic plug. Within the veins, gold grade is highest (up to 70 g/t) close to the granite but rapidly decreases going outward from the granite, defining a perigranitic zoning. Anomalous gold grades have also been measured in hydrothermal skarn layers close to two other granitic plugs (Kaolin granite and Mispickel granite), associated with disseminated As-Fe sulfides. The paragenetic sequence for the W-Au quartz veins shows three stages: (1) an early oxidized stage with wolframite-scheelite associated with early quartz (Q1), (2) an intermediate Bi-As-Te-Mo-Au sulfide stage with loellingite, bismuth minerals and native gold with a later quartz (Q2), restricted to a narrow distance from the granite, and (3) a late lower temperature As-Cu-Zn-(Pb) stage with abundant massive pyrrhotite, arsenopyrite and sphalerite, locally forming independent veins ("pyrrhotite vein"). Both Q1 hyaline and Q2 saccharoidal gold-bearing quartz display aqua-carbonic fluids with minor H2S and Cu and an homogeneous composition (81 mole% H2O, 18 mole% CO2 and about 1 mole% NaCl). The trapping pressure is estimated to 1.5-2 kbar with temperature ranging from 300 to 350 °C. Q1 inclusions have exploded indicating an uplift of the Tighza block, that lead to saccharoidal Q2 quartz deposition with multiphase NaCl-saturated fluid inclusions. 40Ar/39Ar dating demonstrates that the "Mine granite", tungsten skarnoid, scheelite-molybdenite veins, and very likely gold-bearing veins are coeval, emplaced at 286 ± 1 Ma. Multiple and widespread metal sources are indicated by

  20. Completion Report for Well ER-EC-14, Corrective Action Units 101 and 102: Central and Western Pahute Mesa

    Energy Technology Data Exchange (ETDEWEB)

    None

    2013-03-05

    Well ER-EC-14 was drilled for the U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office in support of the Nevada Environmental Management Operations Underground Test Area (UGTA) Activity at the Nevada National Security Site (NNSS; formerly Nevada Test Site), Nye County, Nevada. The well was drilled in September and October 2012, as part of the Central and Western Pahute Mesa Corrective Action Unit Phase II drilling program. The primary purpose of the well was to provide detailed hydrogeologic information for the Fortymile Canyon composite hydrostratigraphic unit in the Timber Mountain moat area, within the Timber Mountain caldera complex, that will help address uncertainties within the Pahute Mesa–Oasis Valley hydrostratigraphic framework model. The main 55.9-centimeter (cm) hole was drilled to a total depth of 325.5 meters (m) and cased with 40.6-cm casing to 308.1 m. The hole diameter was then decreased to 37.5 cm, and drilling continued to a total depth of 724.8 m. The completion casing string, set to the depth of 690.9 m, consists of 16.8-cm stainless-steel casing hanging from 19.4-cm carbon-steel casing. The stainless-steel casing has two slotted intervals open to the Rainier Mesa Tuff. Two piezometer strings were installed in Well ER-EC-14. Both piezometer strings, each with one slotted interval, consist of 6.0-cm carbon-steel tubing at the surface, then cross over to 7.3-cm stainless-steel tubing just above the water table. The shallow piezometer string was landed at 507.8 m, and the deep piezometer string was landed at 688.6 m. Both piezometer strings are set to monitor groundwater within moderately to densely welded Rainier Mesa Tuff. Data collected during and shortly after hole construction include composite drill cuttings samples collected every 3.0 m, various geophysical logs, water quality (including tritium and other radionuclides) measurements, and water level measurements. The well penetrated 15.2 m of alluvium and

  1. Highly differentiated magmas linked with polymetallic mineralization: A case study from the Cuihongshan granitic intrusions, Lesser Xing'an Range, NE China

    Science.gov (United States)

    Fei, Xianghui; Zhang, Zhaochong; Cheng, Zhiguo; Santosh, M.; Jin, Ziliang; Wen, Bingbing; Li, Zixi; Xu, Lijuan

    2018-03-01

    The genetic link between granitoids and polymetallic skarn mineralization has remained equivocal. The Cuihongshan skarn-porphyry W-Mo-Pb-Zn-(Fe-Cu) deposit in the eastern part of the Central Asian Orogenic Belt provides a unique example to address this issue. The major rock types in the mine area are Early Paleozoic intrusions composed of biotite syenogranite and biotite porphyritic granite and Early Mesozoic intrusions represented by porphyritic quartz monzonite, biotite monzogranite, and porphyritic granite. The diagnostic mineralogical and geochemical features indicate that the rocks belong to A2-type granites. The Early Paleozoic suite shows zircon U-Pb ages of 501 Ma, and εHf(t) values of - 4.4 to + 2.7 and + 2.4 to + 7.6, respectively. In combination with their coherent geochemical trends, these rocks are inferred to be products of in-situ differentiation. Although the Mesozoic suite shows crystallization ages of 194-196 Ma, εHf(t) values are in the range of - 2.5 to + 7.5 for the porphyritic quartz monzonite, the - 1.8 to + 4.5 values for the monzogranite and the + 2.3 to + 8.0 range for the porphyritic granite. The porphyritic quartz monzonite displays distinct mineral assemblage and shows significant compositional gap with the other two lithofacies. In contrast, the monzogranite and porphyritic granite have similar geochemical features, and are thus inferred to be co-magmatic. Considering the high SiO2 contents, variable εHf(t) (- 4.4 to + 8.0) and εNd(t) values (- 8.4 to + 0.28) for the two suites, we infer that both episodes of granitoid magmatism resulted from partial melting of crustal materials with a mixed source containing varying proportions of juvenile and Precambrian crustal components. The Early Mesozoic porphyritic granite shows a highly evolved F-rich geochemical affinity, and experienced magma-fluid interaction. Cassiterite from the calcic skarn and the magnesian skarn that coexists with magnetite orebodies shows a mean U-Pb age of 195

  2. Procesos de enmarcamiento y estrategias comunicativas de la Mesa Amplia Nacional Estudiantil en las protestas de 2011 en Colombia

    OpenAIRE

    Edwin Cruz Rodríguez

    2015-01-01

    This article analyzes the framing processes and the communication strategies of the student movement called Mesa Amplia Nacional Estudiantil during the 2011 protests against the higher education reform in Colombia. For this student movement, the main antagonist is the Government and it claims that education is a right and not a commodity; and a battle that goes beyond the university community and the student body is proposed in order to carry out several social and popular acts. The participa...

  3. An alternative method for quantifying coronary artery calcification: the multi-ethnic study of atherosclerosis (MESA).

    Science.gov (United States)

    Liang, C Jason; Budoff, Matthew J; Kaufman, Joel D; Kronmal, Richard A; Brown, Elizabeth R

    2012-07-02

    Extent of atherosclerosis measured by amount of coronary artery calcium (CAC) in computed tomography (CT) has been traditionally assessed using thresholded scoring methods, such as the Agatston score (AS). These thresholded scores have value in clinical prediction, but important information might exist below the threshold, which would have important advantages for understanding genetic, environmental, and other risk factors in atherosclerosis. We developed a semi-automated threshold-free scoring method, the spatially weighted calcium score (SWCS) for CAC in the Multi-Ethnic Study of Atherosclerosis (MESA). Chest CT scans were obtained from 6814 participants in the Multi-Ethnic Study of Atherosclerosis (MESA). The SWCS and the AS were calculated for each of the scans. Cox proportional hazards models and linear regression models were used to evaluate the associations of the scores with CHD events and CHD risk factors. CHD risk factors were summarized using a linear predictor. Among all participants and participants with AS > 0, the SWCS and AS both showed similar strongly significant associations with CHD events (hazard ratios, 1.23 and 1.19 per doubling of SWCS and AS; 95% CI, 1.16 to 1.30 and 1.14 to 1.26) and CHD risk factors (slopes, 0.178 and 0.164; 95% CI, 0.162 to 0.195 and 0.149 to 0.179). Even among participants with AS = 0, an increase in the SWCS was still significantly associated with established CHD risk factors (slope, 0.181; 95% CI, 0.138 to 0.224). The SWCS appeared to be predictive of CHD events even in participants with AS = 0, though those events were rare as expected. The SWCS provides a valid, continuous measure of CAC suitable for quantifying the extent of atherosclerosis without a threshold, which will be useful for examining novel genetic and environmental risk factors for atherosclerosis.

  4. An alternative method for quantifying coronary artery calcification: the multi-ethnic study of atherosclerosis (MESA

    Directory of Open Access Journals (Sweden)

    Liang C

    2012-07-01

    Full Text Available Abstract Background Extent of atherosclerosis measured by amount of coronary artery calcium (CAC in computed tomography (CT has been traditionally assessed using thresholded scoring methods, such as the Agatston score (AS. These thresholded scores have value in clinical prediction, but important information might exist below the threshold, which would have important advantages for understanding genetic, environmental, and other risk factors in atherosclerosis. We developed a semi-automated threshold-free scoring method, the spatially weighted calcium score (SWCS for CAC in the Multi-Ethnic Study of Atherosclerosis (MESA. Methods Chest CT scans were obtained from 6814 participants in the Multi-Ethnic Study of Atherosclerosis (MESA. The SWCS and the AS were calculated for each of the scans. Cox proportional hazards models and linear regression models were used to evaluate the associations of the scores with CHD events and CHD risk factors. CHD risk factors were summarized using a linear predictor. Results Among all participants and participants with AS > 0, the SWCS and AS both showed similar strongly significant associations with CHD events (hazard ratios, 1.23 and 1.19 per doubling of SWCS and AS; 95% CI, 1.16 to 1.30 and 1.14 to 1.26 and CHD risk factors (slopes, 0.178 and 0.164; 95% CI, 0.162 to 0.195 and 0.149 to 0.179. Even among participants with AS = 0, an increase in the SWCS was still significantly associated with established CHD risk factors (slope, 0.181; 95% CI, 0.138 to 0.224. The SWCS appeared to be predictive of CHD events even in participants with AS = 0, though those events were rare as expected. Conclusions The SWCS provides a valid, continuous measure of CAC suitable for quantifying the extent of atherosclerosis without a threshold, which will be useful for examining novel genetic and environmental risk factors for atherosclerosis.

  5. Completion Report for Well ER-12-3 Corrective Action Unit 99: Rainier Mesa - Shoshone Mountain

    International Nuclear Information System (INIS)

    2006-01-01

    Well ER-12-3 was drilled for the U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office, in support of the Nevada Environmental Restoration Project at the Nevada Test Site, Nye County, Nevada. The well was drilled in March and April 2005 as part of a hydrogeologic investigation program for the Rainier Mesa-Shoshone Mountain Corrective Action Unit. The overall purpose of the well was to gather subsurface data to better characterize the hydrogeology of central Rainier Mesa, especially in the older Tertiary volcanic rocks and Paleozoic sedimentary rocks. The main 47.0-centimeter hole was drilled to a depth of 799.2 meters and cased with 33.97-centimeter casing to 743.1 meters. The hole diameter was then decreased to 31.1 centimeters, and the well was drilled to a total depth of 1,496.0 meters. The completion string consisted of 13.97-centimeter stainless steel casing, with two slotted intervals open to the lower carbonate aquifer, suspended from 19.37-centimeter carbon steel casing. A piezometer string was installed outside the 33.97-centimeter casing to a depth of 467.1 meters to monitor a zone of perched water within the Tertiary volcanic section. Data gathered during and shortly after hole construction include composite drill cuttings samples collected every 3 meters (extra cuttings samples were collected from the Paleozoic rocks for paleontological analyses), sidewall core samples from 35 depths, various geophysical logs, and water level measurements. These data indicate that the well penetrated 674.2 meters of Tertiary volcanic rocks and 821.7 meters of Paleozoic dolomite and limestone. Forty-nine days after the well was completed, but prior to well development and testing, the water level inside the main hole was tagged at the depth of 949.1 meters, and the water level inside the piezometer string was tagged at 379.9 meters

  6. DIAGNOSTIC OF TOMATO PRODUTION IN GOIANÁPOLIS, GOIÁS, BRAZIL DIAGNÓSTICO DA CULTURA DO TOMATE DE MESA NO MUNICÍPIO DE GOIANÁPOLIS, ESTADO DE GOIÁS, BRASIL

    Directory of Open Access Journals (Sweden)

    José Ferreira de Noronha

    2007-09-01

    Full Text Available

    This study was concerned with high utilization of pesticides in tomato production, its cost, profitability and enviromental and humam impacts, in the Region of Goianápolis, GO. The data coverd the 1999-2000 harvest. The results show that, amongst the 29 pesticides used by farmers, seven are extremely dangerous, four are very dangerous; eight are dangerous and ten are less dangerous, to human health and the enviroment. Tomatoe producers apply these pesticides, on the average, three times per week. Pesticide containers are disposed in three ways: burnned, burried ou sent to the county sanitary deposit. The Long Life type of tomato presented avergage productivity of 174 boxes/one thousand plants and the Santa Cruz type 130 boxes/one thousand plants. This type of tomatoe production costs were 3.58% higher than the Santa Cruz variety average productivity was 167 boxes/one thousand plants or 56.98 tons/hectare. The tomatoe production markets are the Ceasas in Goiânia and Anápolis and direct sales to buyers from several States. In this case farmers have no waranty that they will receive for their sales to other states. Payment is made by pre-dated check based on the buyers trust. But, it is not unusual to observe cases where final payment is not made and the producers assume total loss.

    Este estudo foi realizado a partir de um censo entre 23 produtores de tomate de mesa. Procurou-se estudar as tecnologias utilizadas, a composição dos custos, a rentabilidade desta atividade e os meios de comercialização da produção do tomate de mesa na região de Goianápolis (GO, no período de setembro de 1999 a julho de 2000. Os dados foram coletados por meio de um questionário individual aplicado aos produtores, que foram visitados periodicamente. Esses produtores foram agrupados de acordo com a tecnologia usada (grupos e

  7. Baseline studies in the desert ecosystem at East Mesa Geothermal Test Site, Imperial Valley, California

    Energy Technology Data Exchange (ETDEWEB)

    Romney, E.M.; Wallace, A.; Lunt, O.R.; Ackerman, T.A.; Kinnear, J.E.

    1977-09-01

    Baseline data reported herein for soil, vegetation, and small mammal components of the East Mesa desert ecosystem represent a collection period from October 1975 to September 1977. Inasmuch as changes in salt balance from geothermal brine sources are of potential impact upon the ecosystem, considerable analytical effort was given to the determination of element constituents in soil, plant, and animal samples. A preliminary synthesis of data was done to investigate the heterogeneity of element constituents among the sampled population and to summarize results. Findings indicate that periodic sampling and chemical analysis of vegetation around an industrialized geothermal energy source is probably the best way to monitor the surrounding ecosystem for assuring containment of any resource pollutants.

  8. Contaminant Transport Parameters for the Groundwater Flow and Contaminant Transport Model of Corrective Action Units 101 and 102: Central and Western Pahute Mesa, Nye County, Nevada, Revision 0

    Energy Technology Data Exchange (ETDEWEB)

    Drici, Warda [International Technologies Corporation, Las Vegas, NV (United States)

    2003-08-01

    This report documents the analysis of the available transport parameter data conducted in support of the development of a Corrective Action Unit (CAU) groundwater flow model for Central and Western Pahute Mesa: CAUs 101 and 102.

  9. Custo de produção de goiabas para mesa produzidas com e sem ensacamento: estudo de caso

    Directory of Open Access Journals (Sweden)

    Tatiane de Oliveira Tokairin

    2014-09-01

    Full Text Available O ensacamento de goiabas para mesa tem por finalidade proteger os frutos contra o ataque de pragas, reduzir a aplicações e os níveis de resíduo de agroquímicos. O objetivo deste trabalho foi avaliar a sustentabilidade econômica da produção de goiabas, por meio da comparação do custo de produção entre os sistemas de cultivo com e sem ensacamento dos frutos. Foi realizado um estudo de caso com dados obtidos de uma propriedade comercial de goiabas para mesa no município de Valinhos - SP. O custo de produção foi calculado do Custo Total (CT, composto pelo Custo Operacional (CO e o Custo Anual de Recuperação do Patrimônio (CARP. Para este estudo de caso, o Custo Total de produção de goiaba ensacada foi de R$ 72.208,39 ha-1, e o da goiaba não ensacada R$ 66.467,30 ha-1. Verificou-se, que para manter a Receita Líquida Total obtida pelo produtor, o preço médio de venda deveria passar de R$ 1,85 kg-1 para, no mínimo, R$ 1,96 kg -1 quando os frutos receberem ensacamento. Ambos os sistemas de produção apresentam-se sustentáveis economicamente.

  10. Mesa NTMS 10 x 20 quadrangle area. Supplemental data report

    International Nuclear Information System (INIS)

    Koller, G.R.

    1980-01-01

    This data report presents supplemental analytical results for stream sediments and ground water. The samples were collected as part of the SRL-NURE reconnaissance in the National Topographic Map Series (NTMS) Mesa 1 0 x 2 0 quadrangle. Results are reported for 24 elements (Ag, As, Ba, Be, Ca, Co, Cr, Cu, K, Li, Mg, Mo, Nb, Ni, P, Pb, Se, Sn, Sr, Th, W, Y, Zn, and extractable U) in sediments and 31 elements (Ag, Al, As, B, Ba, Be, Ca, Ce, Co, Cr, Cu, Fe, K, Li, Mg, Mn, Mo, Na, Nb, Ni, P, Sc, Se, Si, Sr, Th, Ti, V, Y, Zn, and Zr) as well as pH, alkalinity, and conductivity in ground water. Field data and NAA data will be open-filed when they are available. Microfiche cards have been placed in a pocket on the last page of this report. These cards contain the following information: Cards marked Pg. 1, Pg. 2, and Pg. 3 contain histograms, cumulative frequency plots, and areal distribution plots for sediment samples. The card marked Plate 1 is a site-code map for sediment samples

  11. MESA: Message-Based System Analysis Using Runtime Verification

    Science.gov (United States)

    Shafiei, Nastaran; Tkachuk, Oksana; Mehlitz, Peter

    2017-01-01

    In this paper, we present a novel approach and framework for run-time verication of large, safety critical messaging systems. This work was motivated by verifying the System Wide Information Management (SWIM) project of the Federal Aviation Administration (FAA). SWIM provides live air traffic, site and weather data streams for the whole National Airspace System (NAS), which can easily amount to several hundred messages per second. Such safety critical systems cannot be instrumented, therefore, verification and monitoring has to happen using a nonintrusive approach, by connecting to a variety of network interfaces. Due to a large number of potential properties to check, the verification framework needs to support efficient formulation of properties with a suitable Domain Specific Language (DSL). Our approach is to utilize a distributed system that is geared towards connectivity and scalability and interface it at the message queue level to a powerful verification engine. We implemented our approach in the tool called MESA: Message-Based System Analysis, which leverages the open source projects RACE (Runtime for Airspace Concept Evaluation) and TraceContract. RACE is a platform for instantiating and running highly concurrent and distributed systems and enables connectivity to SWIM and scalability. TraceContract is a runtime verication tool that allows for checking traces against properties specified in a powerful DSL. We applied our approach to verify a SWIM service against several requirements.We found errors such as duplicate and out-of-order messages.

  12. Dating of Las Mesas Copper Age walled enclosure (La Fuente, Spain

    Directory of Open Access Journals (Sweden)

    Odriozola, Carlos P.

    2014-12-01

    Full Text Available The site of Las Mesas is located in the west bank of the Guadajira river (La Fuente, Badajoz, Spain. It covers a half hectare and is enclosed by a stone wall. Previous assessments based on site surveys suggested a general chronological span from Late Neolithic period (ca. 3600-2900 BC through the Copper Age (3rd millennium BC. Excavations revealed a well-constructed wall with bastions and a domestic space at the centre of the site with three occupational phases. Several functional areas and a votive pit are ascribed to the second phase. A deer antler located in a re-cut ritual pit associated to the second phase was dated by AMS-14C. Samples from a living floor assigned to the second phase (SU-9/10 and the basement of a kiln associated with the first phase (SU-18 was dated by optically stimulated luminescence (OSL using the single aliquot regenerative dose (SAR protocol on 90-160 m quartz grains. Luminescence profiling analysis of 7 samples taken throughout the archaeological stratigraphy was used to assess variations in luminescence behaviour and relative age through the sequence, using infrared-, optically –and thermally– stimulated luminescence (IRSL, OSL, TSL on poly-mineral and etched samples. Luminescence dating and profiling indicates that the upper archaeological layer (SU-1B probably dates to the Late Bronze Age (ca. 1000 BC, but that the sediments in the remainder of this section accumulated during the late Neolithic-Copper Age: the site was most probably inhabited between 3300 and 2900 BC. There were gaps in occupation between the Late Neolithic-Cooper Age phases (I & II, and between the Late Neolithic-Cooper Age phases and Late Bronze Age phase (II & III, indicating that the site was abandoned and reoccupied twice. The AMS-14C date on deer antler of 4254 ± 45 BP (3010-2675 cal BC is consisten with the OSL results for phase II, indicating that the pit was excavated at the beginning of the second occupational phase. Combined OSL

  13. GIS-based rare events logistic regression for mineral prospectivity mapping

    Science.gov (United States)

    Xiong, Yihui; Zuo, Renguang

    2018-02-01

    Mineralization is a special type of singularity event, and can be considered as a rare event, because within a specific study area the number of prospective locations (1s) are considerably fewer than the number of non-prospective locations (0s). In this study, GIS-based rare events logistic regression (RELR) was used to map the mineral prospectivity in the southwestern Fujian Province, China. An odds ratio was used to measure the relative importance of the evidence variables with respect to mineralization. The results suggest that formations, granites, and skarn alterations, followed by faults and aeromagnetic anomaly are the most important indicators for the formation of Fe-related mineralization in the study area. The prediction rate and the area under the curve (AUC) values show that areas with higher probability have a strong spatial relationship with the known mineral deposits. Comparing the results with original logistic regression (OLR) demonstrates that the GIS-based RELR performs better than OLR. The prospectivity map obtained in this study benefits the search for skarn Fe-related mineralization in the study area.

  14. Ranking Tenis Soft V1: Software para el Control del Ranking del Tenis de Mesa

    Directory of Open Access Journals (Sweden)

    Santiago Calero Morales

    2009-12-01

    Full Text Available El trabajo enumera algunos pasos metodológicos a tener en cuenta para el diseño de un sistema informático. En la confección del mismo se estudió varias características del mercado nacional, aspecto que tributa en el diseño del negocio, la selección del lenguaje de programación y el gestor de bases de datos, así como la confección del sistema de ayuda, entre otros aspectos. El software ha sido implementado en el país por parte de la Federación Nacional de Tesis de Mesa en algunas competencias, con vistas a depurar el código y a fiscalizar las competiciones auspiciadas por ésta.

  15. Polygenetic Aspect of Unit Theory Oil Generation

    Science.gov (United States)

    Galant, Yuri

    2015-04-01

    In the framework of a unified theory Oil Generation one of important moments is the consideration of the distribution of oil in the Earth's Crust. Analysis of the distribution of oil deposits in the Earth's Crust showed that oil distributed throughout the stratigraphic section from ancient to modern sediments and from a depth of 12 kilometers to the Earth's surface. The distribution of oil almost meets all stages of metamorphism of rocks. Correlation of the section of oil distribution to genetic types of ore deposits showed that each genetic type ore deposits has its analogue oil field . So it is possible to classify oil fields on 1) endogenous: the actual magmatic, post-magmatic, contact-metasomatic (skarn), hydrothermal, exhalation, carbonatite, pegmatite, 2) exogenous: weathering, oxidation, sedimentary,3) metamorphogenic: metamorphosed, metamorphic. Model of such distribution of oil deposits can be a process of successive formation of oil deposits of mantle degassing tube. Thus oil is polygenic by way of formation of deposits, but their source is united.

  16. Una experiencia singular: el proceso de reconversión de los deportistas de alto rendimiento en Francia en esgrima y tenis de mesa

    Directory of Open Access Journals (Sweden)

    Sophie Javerlhiac

    2010-01-01

    Full Text Available El presente trabajo muestra las dificultades con las que se encuentran los Deportistas de Alto Rendimiento (DAR a la hora de poder compaginar sus carreras deportivas con su formación académica y profesional. Para ilustrar esta realidad, se ha analizado la situación de nueve DAR franceses en esgrima y tenis de mesa. Los resultados muestran cómo existen diferencias significativas entre los DAR de ambos deportes. Por un lado, los tiradores de esgrima compatibilizan la práctica deportiva con su formación, ya que son conscientes de la necesidad de desarrollarse profesionalmente una vez finalizada su carrera deportiva. Esta situación es favorecida, principalmente, por la federación y por el ejemplo de otros deportistas. Por el contrario, los jugadores de tenis de mesa siguen un modelo monodeportivo, el cual se focaliza desde muy temprano en la práctica deportiva y deja a un lado la formación. Tanto la federación, los técnicos como los propios compañeros de equipo crean un ambiente en donde "salirse de la norma" implica un rechazo. Esta situación es analizada detenidamente.

  17. Factors influencing time-location patterns and their impact on estimates of exposure: the Multi-Ethnic Study of Atherosclerosis and Air Pollution (MESA Air).

    Science.gov (United States)

    Spalt, Elizabeth W; Curl, Cynthia L; Allen, Ryan W; Cohen, Martin; Williams, Kayleen; Hirsch, Jana A; Adar, Sara D; Kaufman, Joel D

    2016-06-01

    We assessed time-location patterns and the role of individual- and residential-level characteristics on these patterns within the Multi-Ethnic Study of Atherosclerosis and Air Pollution (MESA Air) cohort and also investigated the impact of individual-level time-location patterns on individual-level estimates of exposure to outdoor air pollution. Reported time-location patterns varied significantly by demographic factors such as age, gender, race/ethnicity, income, education, and employment status. On average, Chinese participants reported spending significantly more time indoors and less time outdoors and in transit than White, Black, or Hispanic participants. Using a tiered linear regression approach, we predicted time indoors at home and total time indoors. Our model, developed using forward-selection procedures, explained 43% of the variability in time spent indoors at home, and incorporated demographic, health, lifestyle, and built environment factors. Time-weighted air pollution predictions calculated using recommended time indoors from USEPA overestimated exposures as compared with predictions made with MESA Air participant-specific information. These data fill an important gap in the literature by describing the impact of individual and residential characteristics on time-location patterns and by demonstrating the impact of population-specific data on exposure estimates.

  18. Unclassified Source Term and Radionuclide Data for the Groundwater Flow and Contaminant Transport Model of Corrective Action Units 101 and 102: Central and Western Pahute Mesa, Nye County, Nevada, Revision 0

    Energy Technology Data Exchange (ETDEWEB)

    McCord, John

    2004-08-01

    This report documents the evaluation of the information and data available on the unclassified source term and radionuclide contamination for Central and Western Pahute Mesa: Corrective Action Units (CAUs) 101 and 102.

  19. Relación entre locus de control, ira y rendimiento deportivo en jugadores de tenis de mesa

    Directory of Open Access Journals (Sweden)

    Higinio González-García

    2017-01-01

    Full Text Available Los objetivos de este estudio fueron comprobar la relación entre el locus de control y el rendimiento de- portivo, y conocer la relación entre el locus de control y las variables de ira. La muestra de la investigación se compuso de 58 jugadores federados de tenis de mesa de toda la geografía española. Los participantes completa- ron un cuestionario sociodemográfico ad hoc , la Escala de Locus de Control (ELC y el Inventario de Expresión de la Ira Estado-Rasgo (STAXI-2. Los resultados revela- ron que no había diferencias de medias en los niveles de locus de control externo en función de la división de juego y del tipo de práctica deportiva (profesionales vs amateurs. Por otro lado, se confirmó la relación entre el locus de control externo y la expresión externa de la ira, encontrándose diferencias estadísticamente signifi- cativas entre la expresión externa de la ira y los grupos de locus de control externo alto y bajo. Finalmente, se concluyó que el nivel de rendimiento deportivo no in- terfería en los niveles de locus de control y, por otro lado, se confirma la relación del locus de control exter- no en la expresión externa de la ira de los jugadores de tenis de mesa. Por lo tanto, el locus de control interno se muestra como una variable protectora importante para intervenir con jugadores y entrenadores.

  20. Preliminary study of the uranium favorability of granitic and contact-metamorphic rocks of the Owens Valley area, Inyo and Mono Counties, California, and Esmeralda and Mineral Counties, Nevada

    International Nuclear Information System (INIS)

    Cupp, G.M.; Mitchell, T.P.

    1978-01-01

    Granitic and contact-metamorphic rocks of the Owens Valley area were sampled to determine their favorability for uranium. Uranium deposits associated with these rocks were examined to determine the mode of occurrence. Metamorphic rocks near contacts with intrusive rocks include skarns, schists, quartzites, metaconglomerates, hornfels, gneisses, and metavolcanics. The grade of contact metamorphism ranges from slight to intense, depending upon the distance from the intrusive contact. The average U 3 O 8 content of the metamorphic rock samples is 3 ppM. Metamorphic rock samples in a roof pendant at the Claw prospect contain as much as 3 percent U 3 O 8 . Skarn samples from the Birch Creek pluton contain as much as 114 ppM U 3 O 8 ; those from the Santa Rita Flat pluton contain as much as 23 ppM U 3 O 8 . Most of the intrusive rocks are granite, quartz monzonite, or monzonite. Granodiorite and diorite are less common, and gabbro is rare. The average U 3 O 8 content of the crystalline rock samples is 4 ppM. Samples from a quartz-monzonite pluton east of Lone Pine, California, and quartz monzonite in the Santa Rosa Hills had maximum contents of 28 and 13 ppM U 3 O 8 , respectively. Areas of contact metamorphism and metasomatism, such as those at the Claw prospect and Birch Creek pluton, are probably the most favorable sites for uranium deposits. There are many miles of granitic and contact-metamorphic zones in which undiscovered uranium deposits may exist. Although the overall uranium content of granitic rocks appears to be low, the pluton east of Lone Pine and the Hunter Mountain pluton in the area of the Santa Rosa Hills have sufficient uranium to have acted as uranium and detrital source rocks for uranium deposits that may now be buried in Tertiary sediments in the basins around the plutons. The Claw deposit is the only known uranium deposit of a size and grade to be of possible commercial interest

  1. Characterisation of Al{sub 0.52}In{sub 0.48}P mesa p-i-n photodiodes for X-ray photon counting spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Butera, S., E-mail: S.Butera@sussex.ac.uk; Lioliou, G.; Barnett, A. M. [Semiconductor Materials and Device Laboratory, School of Engineering and Informatics, University of Sussex, Brighton BN1 9QT (United Kingdom); Krysa, A. B. [EPSRC National Centre for III-V Technologies, University of Sheffield, Mappin Street, Sheffield S1 3JD (United Kingdom)

    2016-07-14

    Results characterising the performance of thin (2 μm i-layer) Al{sub 0.52}In{sub 0.48}P p{sup +}-i-n{sup +} mesa photodiodes for X-ray photon counting spectroscopy are reported at room temperature. Two 200 μm diameter and two 400 μm diameter Al{sub 0.52}In{sub 0.48}P p{sup +}-i-n{sup +} mesa photodiodes were studied. Dark current results as a function of applied reverse bias are shown; dark current densities <3 nA/cm{sup 2} were observed at 30 V (150 kV/cm) for all the devices analysed. Capacitance measurements as a function of applied reverse bias are also reported. X-ray spectra were collected using 10 μs shaping time, with the device illuminated by an {sup 55}Fe radioisotope X-ray source. Experimental results showed that the best energy resolution (FWHM) achieved at 5.9 keV was 930 eV for the 200 μm Al{sub 0.52}In{sub 0.48}P diameter devices, when reverse biased at 15 V. System noise analysis was also carried out, and the different noise contributions were computed.

  2. Land subsidence caused by the East Mesa geothermal field, California, observed using SAR interferometry

    Science.gov (United States)

    Massonnet, D.; Holzer, T.; Vadon, H.

    1997-01-01

    Interferometric combination of pairs of synthetic aperture radar (SAR) images acquired by the ERS-1 satellite maps the deformation field associated with the activity of the East Mesa geothermal plant, located in southern California. SAR interferometry is applied to this flat area without the need of a digital terrain model. Several combinations are used to ascertain the nature of the phenomenon. Short term interferograms reveal surface phase changes on agricultural fields similar to what had been observed previously with SEASAT radar data. Long term (2 years) interferograms allow the study of land subsidence and improve prior knowledge of the displacement field, and agree with existing, sparse levelling data. This example illustrates the power of the interferometric technique for deriving accurate industrial intelligence as well as its potential for legal action, in cases involving environmental damages. Copyright 1997 by the American Geophysical Union.

  3. Practical results of the MESA 1 line calcinator trial operation

    International Nuclear Information System (INIS)

    Napravnik, J.; Sazavsky, P.; Skaba, V.; Zahalka, F.; Vild, J.; Kulovany, J.

    1987-01-01

    Mobile calcination and cementation unit MESA 1 was designed and built by UJV Rez in cooperation with many enterprises, mainly with the Kralovopolske Strojirny Brno. This facility for direct fixation of liquid radioactive wastes was experimentally tested using model non-radioactive solutions and model and actual wastes from the Jaslovske Bohunice nuclear power plant. The calciner was run in trial operation at the Kralovopolske SAtrojirny Brno. A total of 1.3 m 3 of model solutions was processed into 180 kg of calcinate. The fixation of the calcinate in cement, the times of solidification and of hardening and the moisture content of concrete blocks were studied. The application was also tested of the calciner in drying ion exchangers from WWER-440 prior to their bituminization. Following the despatch of the cementation module to the Chernobyl nuclear power plant, the direct calcination module was tested at Dukovany together with an auxiliary module which makes possible self-contained calciner operation. Model non-radioactive solutions from the Dukovany nuclear power plant were treated containing H 3 BO 3 and NaNO 3 as main components. The usability in actual conditions of the mobile calcination and cementation unit for radioactive wastes was tested in a total of about 70 operating hours. (E.S.). 2 figs., 2 refs

  4. Mineralogy, occurrence of mineralization and temperature-pressure conditions of the Agh-Daragh polymetallic deposit in the Ahar-Arasbaran metallogenic area

    Directory of Open Access Journals (Sweden)

    Heydar Asgharzadeh Asl

    2017-07-01

    reproducibility of ±1°C. However, it was reduced to 0.1–0.5°C/min near phase transformation, with a reproducibility of ±0.1°C. Results Mineralization that occurs in the area is mainly related to the Sheiviar Dagh intrusive rocks and it includes a variety of types of skarn, porphyry- and vein-type, epithermal and intrusion related deposits. Agh Daragh mineralization occurs at least in three states including: 1 stockwork-disseminated, 2 vein-type and 3 replacement (skarn. In order to determine the nature and characteristics of granodiorites hosted Ayran Goli mineralization, the biotites points were analyzed. The Ayran Goli granodiorite with calc-alkaline nature is related to orogenic zones that is associated with subduction zones. To determine the chemical properties of the minerals in Gowdal skarn mineralization, garnet and chlorite have been used for analysis which are often located at repidolite and picnochlorite positions. Electron micro probe analysis (EMPA of magnetite from the Chupanlar area showed that it belongs to porphyry and Kiruna type deposits. Based on the observations made, three types of aqueous fluid inclusions were distinguished in the quartz-sulfide veins, including halite-saturated aqueous (H2O–NaCl±KCl, aqueous two-phase (H2O–NaCl±CaCl2, and monophase liquid and vapor fluid inclusions. Discussion Because of the lack of CO2-bearing fluid inclusions phase in the samples, we used a temperature-pressure relationship intersection in order to obtain the depth of mineralization. However, but at this study salt-rich inclusions (type 1 the dissolution of halite homogeneous solid phase (Bodnar, 1994 were used in order to estimate the standing deposit. Considering the temperature of the liquid-vapor homogenization (Thl-v, temperatures between 201 to 474°C, homogenization halite (TmNaCl between 196 to 434°C (48 wt% NaCl eq. in the solid phase inclusions with halite, minimum and the maximum pressure between 4.0 and 7.2, respectively that occur at 0.4 to 2

  5. What is the reason for the doubled unit-cell volumes of copper-lead-rich pavonite homologues?

    DEFF Research Database (Denmark)

    Topa, Dan; Makovicky, Emil; Balic Zunic, Tonci

    2008-01-01

    The crystal Structure of cupromakovickyite, ideally Cu8Pb4Ag2Bi18S36, from the skarn deposit at Baita Bihor, in Romania, has been solved by direct methods and refined to an RI index of 5.36% for 2680 unique reflections measured with MOKU radiation oil it four-circle diffractometer equipped...... parameter for cupromakovickyite with respect to makovickyite. To be able to compare them, the crystal structure of Cu-bearing makovickyite, Cu2.25Ag1.56 (Pb0.27Cd0.13)(Sigma 0.4)Bi10.46S18, from a scheelite deposit at Felbertal, in Austria, has been refined to in R, index of 4.36% for 1320 unique...

  6. Keeping Energy Savings in the LOOP: Mesa Lane Partners Case Study

    Energy Technology Data Exchange (ETDEWEB)

    None

    2013-03-01

    Mesa Lane Partners (MLP) partnered with the U.S. Department of Energy (DOE) to develop and implement solutions to a build a new, low-energy mixed-use building that consumes at least 50% less energy than requirements set by Energy Standard 90.1-2007 of the American Society of Heating, Refrigerating, and Air-conditioning Engineers (ASHRAE), the American National Standards Institute (ANSI), and the Illuminating Engineering Society of America (IESNA), as part of DOE’s Commercial Building Partnerships (CBP) Program. Lawrence Berkeley National Laboratory (LBNL) provided technical expertise in support of this DOE program. The privately developed 46,000-square-foot LOOP project, which is intended to provide affordable off-campus student housing in an underserved community next to University of California at Santa Barbara, will contain more than 7,000 square feet of retail space, a roof deck, an event space, a gym, and 48 apartments. The project developer, MLP, is aiming to exceed CBP requirement, targeting energy consumption that is at least 65% less than that required by the standard. If the LOOP meets this goal, it is expected to achieve Leadership in Energy and Environmental Design (LEED) Gold certification.

  7. Mineralogical and Geochemical Characterization of the Kimmeria Intrusion-Related Deposit, Xanthi, NE Greece

    Science.gov (United States)

    Theodoridou, Stella; Melfos, Vasilios; Voudouris, Panagiotis; Miskovic, Aleksandar

    2016-04-01

    Although intrusion-related systems have not been previously recognized in the European segment of the Tethyan Metallogenic Belt, the Rhodope metallogenic province of SE Balkan peninsula hosts numerous such occurrences. The Kimmeria hydrothermal system incorporates two styles of ore mineralization: i) a massive Au-bearing magnetite-pyrrhotite skarn and ii) a Mo-Cu-Bi-W quartz vein-hosted mineralization, both of which are related to the Oligocene Xanthi pluton (25.5±1.2 to 30±1 My, K-Ar in hornblende and biotite). The Xanthi pluton, consisting of I-type gabbros, monzonites and amphibole-biotite granodiorites, intrudes the basement gneisses, mica schists, amphibolites and marbles of the Southern Rhodope Core Complex; a dome that has gradually exhumed from Paleocene/mid Eocene to Miocene (starting between 65 and >42 to 10 My). The Xanthi pluton emplacement and the magmatically derived hydrothermal fluid circulation were controlled by two major regional structures: the low-angle Kavala-Xanthi-Komotini detachment fault and the Nestos thrust fault. The Kimmeria Au-Cu-Fe skarn mineralization features a well-preserved aureole at the contact between the granodiorite and the surrounding marbles. It consists of two paragenetic stages comprising magnetite and pyrrhotite-rich assemblages. Alteration minerals comprise chlorite and sericite. Bulk chemical analyses of the skarn mineralization revealed relatively high concentration of Cu (1 wt.%), Pb (288 ppm) and Zn (0.74 wt.%). The mineralization is also enriched in As (molybdenite as dominant sulfides. Minor sphalerite, tetrahedrite-tennantite, galena and rutile are also present, while sericite and chlorite as the alteration minerals. The Cu and Mo content of the vein type mineralization exceed 1.0 and 0.2 wt.% respectively, along with < 2.7 ppm Au, 1.3 to 79.5 ppm W and 0.6 to 456 ppm Bi. A first approach fluid study has revealed small variations in δ34S values of sulfides (0 - 2.3 ‰ VCDT) from both types of mineralization

  8. Hydrothermal Fluid evolution in the Dalli porphyry Cu-Au Deposit: Fluid Inclusion microthermometry studies

    Directory of Open Access Journals (Sweden)

    Alireza Zarasvandi

    2015-10-01

    Full Text Available Introduction A wide variety of world-class porphyry Cu deposits occur in the Urumieh-Dohktar magmatic arc (UDMA of Iran.The arc is composed of calc-alkaline granitoid rocks, and the ore-hosting porphyry intrusions are dominantly granodiorite to quartz-monzonite (Zarasvandi et al., 2015. It is believed that faults played an important role in the emplacement of intrusions and subsequentporphyry-copper type mineralization (Shahabpour, 1999. Three main centers host the porphyry copper mineralization in the UDMA: (1 Ardestan-SarCheshmeh-Kharestan zone, (2 Saveh-Ardestan district; in the central parts of the UDMA, hosting the Dalli porphyry Cu-Au deposit, and (3 Takab-Mianeh-Qharahdagh-Sabalan zone. Mineralized porphyry coppersystems in the UDMA are restricted to Oligocene to Mioceneintrusions and show potassic, sericitic, argillic, propylitic and locally skarn alteration (Zarasvandi et al., 2005; Zarasvandi et al., 2015. In the Dalli porphyry deposit, four hydrothermal alteration zones, includingpotassic, sericitic, propylitic, and argillic types have been described in the two discrete mineralized areas, namely, northern and southern stocks. Hypogenemineralization includes chalcopyrite, pyrite, and magnetite, with minor occurrences of bornite.Supergene activity has produced gossan, oxidized minerals and enrichment zones. The supergene enrichment zone contains chalcocite and covellite with a 10-20 m thickness. Mineralization in the northern stock is mainly composed of pyrite and chalcopyrite. The aim of this study is the investigation and classification of hydrothermal veins and the constraining of physicochemical compositions of ore-forming fluids using systematic investigation of fluid inclusions. Materials and methods Twenty samples were collected from drill holes. Thin and polished sections were prepared from hydrothermal veins of thepotassic, sericitic and propylitic alteration zones. Samples used for fluid inclusion measurements were collected

  9. Marcos de interacción y construcción del sentido: el caso del lexema mesa en expresiones locativas con las preposiciones sobre, en y a

    Directory of Open Access Journals (Sweden)

    Patricia Carmen Hernández

    2014-11-01

    Full Text Available Nuestra contribución analiza el comportamiento semántico-pragmático del ítem léxico mesa en combinación con las preposiciones sobre, en y a en expresiones locativas. La perspectiva presentada en este artículo es que (i más que una simple etiqueta referencial, las palabras son modos de acceso a la experiencia subjetiva y social de los hablantes y (ii la construcción del sentido es un proceso holístico que supone la determinación recíproca de las unidades lingüísticas. Se exploran las relaciones entre el lexema mesa, las preposiciones y los verbos empleados más frecuentemente en construcciones locativas en base a un estudio cualitativo de 686 ocurrencias. Enmarcada en la Lingüística Cognitiva, nuestra aproximación teórica se basa substancialmente en los conceptos de rol télico, marcos de interacción, zonas activas y conexiones metonímicas. 

  10. Mountainous Ecosystem Sensor Array (MESA): a mesh sensor network for climate change research in remote mountainous environments

    Science.gov (United States)

    Robinson, P. W.; Neal, D.; Frome, D.; Kavanagh, K.; Davis, A.; Gessler, P. E.; Hess, H.; Holden, Z. A.; Link, T. E.; Newingham, B. A.; Smith, A. M.

    2013-12-01

    Developing sensor networks robust enough to perform unattended in the world's remote regions is critical since these regions serve as important benchmarks that lack anthropogenic influence. Paradoxically, the factors that make these remote, natural sites challenging for sensor networking are often what make them indispensable for climate change research. The MESA (Mountainous Ecosystem Sensor Array) project has faced these challenges and developed a wireless mesh sensor network across a 660 m topoclimatic gradient in a wilderness area in central Idaho. This sensor array uses advances in sensing, networking, and power supply technologies to provide near real-time synchronized data covering a suite of biophysical parameters used in ecosystem process models. The 76 sensors in the network monitor atmospheric carbon dioxide concentration, humidity, air and soil temperature, soil water content, precipitation, incoming and outgoing shortwave and longwave radiation, snow depth, wind speed and direction, and leaf wetness at synchronized time intervals ranging from two minutes to two hours and spatial scales from a few meters to two kilometers. We present our novel methods of placing sensors and network nodes above, below, and throughout the forest canopy without using meteorological towers. In addition, we explain our decision to use different forms of power (wind and solar) and the equipment we use to control and integrate power harvesting. Further, we describe our use of the network to sense and quantify its own power use. Using examples of environmental data from the project, we discuss how these data may be used to increase our understanding of the effects of climate change on ecosystem processes in mountainous environments. MESA sensor locations across a 700 m topoclimatic gradient at the University of Idaho Taylor Wilderness Research Station.

  11. 'Black star': uma mutação somática natural da uva fina de mesa cv. Brasil

    OpenAIRE

    Roberto,Sergio Ruffo; Assis,Adriane Marinho de; Genta,Werner; Yamamoto,Lilian Yukari; Sato,Alessandro Jefferson

    2012-01-01

    A uva fina de mesa 'Black Star', originada de uma mutação somática da uva cv. Brasil em Marialva-PR, é descrita quanto às suas principais características físico-químicas e produtivas. Suas bagas, com sementes, apresentam formato elipsoide alongado com coloração vermelho-escura, tendendo ao preto durante a maturação plena. O ciclo, o desempenho produtivo e a suscetibilidade às doenças fúngicas assemelham-se aos da cv. Itália. Durante a maturação plena, apresenta teor médio de sólidos solúveis ...

  12. Phase I Transport Model of Corrective Action Units 101 and 102: Central and Western Pahute Mesa, Nevada Test Site, Nye County, Nevada with Errata Sheet 1, 2, 3, Revision 1

    Energy Technology Data Exchange (ETDEWEB)

    Greg Ruskauff

    2009-02-01

    As prescribed in the Pahute Mesa Corrective Action Investigation Plan (CAIP) (DOE/NV, 1999) and Appendix VI of the Federal Facility Agreement and Consent Order (FFACO) (1996, as amended February 2008), the ultimate goal of transport analysis is to develop stochastic predictions of a contaminant boundary at a specified level of uncertainty. However, because of the significant uncertainty of the model results, the primary goal of this report was modified through mutual agreement between the DOE and the State of Nevada to assess the primary model components that contribute to this uncertainty and to postpone defining the contaminant boundary until additional model refinement is completed. Therefore, the role of this analysis has been to understand the behavior of radionuclide migration in the Pahute Mesa (PM) Corrective Action Unit (CAU) model and to define, both qualitatively and quantitatively, the sensitivity of such behavior to (flow) model conceptualization and (flow and transport) parameterization.

  13. The chemistry of hydrothermal magnetite: a review

    Science.gov (United States)

    Nadoll, Patrick; Angerer, Thomas; Mauk, Jeffrey L.; French, David; Walshe, John

    2014-01-01

    Magnetite (Fe3O4) is a well-recognized petrogenetic indicator and is a common accessory mineral in many ore deposits and their host rocks. Recent years have seen an increased interest in the use of hydrothermal magnetite for provenance studies and as a pathfinder for mineral exploration. A number of studies have investigated how specific formation conditions are reflected in the composition of the respective magnetite. Two fundamental questions underlie these efforts — (i) How can the composition of igneous and, more importantly, hydrothermal magnetite be used to discriminate mineralized areas from barren host rocks, and (ii) how can this assist exploration geologists to target ore deposits at greater and greater distances from the main mineralization? Similar to igneous magnetite, the most important factors that govern compositional variations in hydrothermal magnetite are (A) temperature, (B) fluid composition — element availability, (C) oxygen and sulfur fugacity, (D) silicate and sulfide activity, (E) host rock buffering, (F) re-equilibration processes, and (G) intrinsic crystallographic controls such as ionic radius and charge balance. We discuss how specific formation conditions are reflected in the composition of magnetite and review studies that investigate the chemistry of hydrothermal and igneous magnetite from various mineral deposits and their host rocks. Furthermore, we discuss the redox-related alteration of magnetite (martitization and mushketovitization) and mineral inclusions in magnetite and their effect on chemical analyses. Our database includes published and previously unpublished magnetite minor and trace element data for magnetite from (1) banded iron formations (BIF) and related high-grade iron ore deposits in Western Australia, India, and Brazil, (2) Ag–Pb–Zn veins of the Coeur d'Alene district, United States, (3) porphyry Cu–(Au)–(Mo) deposits and associated (4) calcic and magnesian skarn deposits in the southwestern United

  14. Mi Caída: Testimonio histórico del ex presidente de Bolivia Carlos Mesa Gisbert sobre su “presidencia sitiada” (2003/2005

    Directory of Open Access Journals (Sweden)

    Juan Eduardo Mendoza Pinto

    2016-10-01

    Full Text Available Presentamos un documento inédito sobre los conmovedores acontecimientos vividos por el Estado y la sociedad boliviana en la difícil coyuntura 2003/2005, asociada a la presidencia de Carlos Mesa G., que nos deja aquí una testificación directa, del más alto nivel, sobre ese trance histórico, de indudable valor para la historia contemporánea de América Latina.

  15. Potential long-term chemical effects of diesel fuel emissions on a mining environment: A preliminary assessment based on data from a deep subsurface tunnel at Rainer Mesa, Nevada test site

    Energy Technology Data Exchange (ETDEWEB)

    Meike, A.; Bourcier, W.L.; Alai, M. [and others

    1995-09-01

    The general purpose of the Yucca Mountain Site Characterization Project (YMSCP) Introduced Materials Task is to understand and predict potential long-term modifications of natural water chemistry related to the construction and operation of a radioactive waste repository that may significantly affect performance of the waste packages. The present study focuses on diesel exhaust. Although chemical information on diesel exhaust exists in the literature, it is either not explicit or incomplete, and none of it establishes mechanisms that might be used to predict long-term behavior. In addition, the data regarding microbially mediated chemical reactions are not well correlated with the abiotic chemical data. To obtain some of the required long-term information, we chose a historical analog: the U12n tunnel at Rainier Mesa, Nevada Test Site. This choice was based on the tunnel`s extended (30-year) history of diesel usage, its geological similarity to Yucca Mountain, and its availability. The sample site within the tunnel was chosen based on visual inspection and on information gathered from miners who were present during tunnel operations. The thick layer of dark deposit at that site was assumed to consist primarily of rock powder and diesel exhaust. Surface samples and core samples were collected with an intent to analyze the deposit and to measure potential migration of chemical components into the rock. X-ray diffraction (XRD), x-ray fluorescence (XRF), scanning electron microscopy (SEM) with energy dispersive spectra (EDS) analysis, secondary-ion mass spectrometry (SIMS), and Fourier transform infrared (FTIR) analysis were used to measure both spatial distribution and concentration for the wide variety of chemical components that were expected based on our literature survey.

  16. Potential long-term chemical effects of diesel fuel emissions on a mining environment: A preliminary assessment based on data from a deep subsurface tunnel at Rainer Mesa, Nevada test site

    International Nuclear Information System (INIS)

    Meike, A.; Bourcier, W.L.; Alai, M.

    1995-09-01

    The general purpose of the Yucca Mountain Site Characterization Project (YMSCP) Introduced Materials Task is to understand and predict potential long-term modifications of natural water chemistry related to the construction and operation of a radioactive waste repository that may significantly affect performance of the waste packages. The present study focuses on diesel exhaust. Although chemical information on diesel exhaust exists in the literature, it is either not explicit or incomplete, and none of it establishes mechanisms that might be used to predict long-term behavior. In addition, the data regarding microbially mediated chemical reactions are not well correlated with the abiotic chemical data. To obtain some of the required long-term information, we chose a historical analog: the U12n tunnel at Rainier Mesa, Nevada Test Site. This choice was based on the tunnel's extended (30-year) history of diesel usage, its geological similarity to Yucca Mountain, and its availability. The sample site within the tunnel was chosen based on visual inspection and on information gathered from miners who were present during tunnel operations. The thick layer of dark deposit at that site was assumed to consist primarily of rock powder and diesel exhaust. Surface samples and core samples were collected with an intent to analyze the deposit and to measure potential migration of chemical components into the rock. X-ray diffraction (XRD), x-ray fluorescence (XRF), scanning electron microscopy (SEM) with energy dispersive spectra (EDS) analysis, secondary-ion mass spectrometry (SIMS), and Fourier transform infrared (FTIR) analysis were used to measure both spatial distribution and concentration for the wide variety of chemical components that were expected based on our literature survey

  17. Field-based description of rhyolite lava flows of the Calico Hills Formation, Nevada National Security Site, Nevada

    Science.gov (United States)

    Sweetkind, Donald S.; Bova, Shiera C.

    2015-01-01

    Contaminants introduced into the subsurface of Pahute Mesa, Nevada National Security Site, by underground nuclear testing are of concern to the U.S. Department of Energy and regulators responsible for protecting human health and safety. The potential for contaminant movement away from the underground test areas at Pahute Mesa and into the accessible environment is greatest by groundwater transport through fractured volcanic rocks. The 12.9 Ma (mega-annums, million years) Calico Hills Formation, which consists of a mixture of rhyolite lava flows and intercalated nonwelded and bedded tuff and pyroclastic flow deposits, occurs in two areas of the Nevada National Security Site. One area is north of the Rainier Mesa caldera, buried beneath Pahute Mesa, and serves as a heterogeneous volcanic-rock aquifer but is only available to study through drilling and is not described in this report. A second accumulation of the formation is south of the Rainier Mesa caldera and is exposed in outcrop along the western boundary of the Nevada National Security Site at the Calico Hills near Yucca Mountain. These outcrops expose in three dimensions an interlayered sequence of tuff and lava flows similar to those intercepted in the subsurface beneath Pahute Mesa. Field description and geologic mapping of these exposures described lithostratigraphic variations within lava flows and assisted in, or at least corroborated, conceptualization of the rhyolite lava-bearing parts of the formation.

  18. Geologic investigation of the Virgin River Valley salt deposits, Clark County, southeastern Nevada, to investigate their suitability for possible storage of radioactive waste material as of September 1977

    International Nuclear Information System (INIS)

    1977-01-01

    The results from a geologic investigation of the Virgin River Valley salt deposits, Clark County, southeastern Nevada, to examine their suitability for further study and consideration in connection with the possible storage of radioactive waste material are given. The results indicate that (1) approximately one-half of the salt body underlies the Overton Arm of Lake Mead and that the dry land portion of the salt body that has a thickness of 1,000 feet or more covers an area of about four and one-half square miles; (2) current tectonic activity in the area of the salt deposits is believed to be confined to seismic events associated with crustal adjustments following the filling of Lake Mead; (3) detailed information on the hydrology of the salt deposit area is not available at present but it is reported that a groundwater study by the U.S. Geological Survey is now in progress; (4) there is no evidence of exploitable minerals in the salt deposit area other than evaporites such as salt, gypsum, and possibly sand and gravel; (5) the salt deposit area is located inside the Lake Mead Recreation Area, outlined on the accompanying Location Plat, and several Federal, State, and Local agencies share regulatory responsibilities for the activities in the area; (6) other salt deposit areas of Arizona and Nevada, such as the Detrital Valley, Red Lake Dome, Luke Dome, and Mormon Mesa area, and several playa lake areas of central Nevada may merit further study; and (7) additional information, as outlined, is needed to more thoroughly evaluate the salt deposits of the Virgin River Valley and other areas referred to above

  19. Reduced thermal resistance in AlGaN/GaN multi-mesa-channel high electron mobility transistors

    Energy Technology Data Exchange (ETDEWEB)

    Asubar, Joel T., E-mail: joel@rciqe.hokudai.ac.jp; Yatabe, Zenji; Hashizume, Tamotsu [Research Center for Integrated Quantum Electronics (RCIQE) and Graduate School of Information Science and Technology, Hokkaido University, Sapporo (Japan); Japan Science and Technology Agency (JST), CREST, 102-0075 Tokyo (Japan)

    2014-08-04

    Dramatic reduction of thermal resistance was achieved in AlGaN/GaN Multi-Mesa-Channel (MMC) high electron mobility transistors (HEMTs) on sapphire substrates. Compared with the conventional planar device, the MMC HEMT exhibits much less negative slope of the I{sub D}-V{sub DS} curves at high V{sub DS} regime, indicating less self-heating. Using a method proposed by Menozzi and co-workers, we obtained a thermal resistance of 4.8 K-mm/W at ambient temperature of ∼350 K and power dissipation of ∼9 W/mm. This value compares well to 4.1 K-mm/W, which is the thermal resistance of AlGaN/GaN HEMTs on expensive single crystal diamond substrates and the lowest reported value in literature.

  20. Cryogenic scanning laser microscopy. Investigation of large BSCCO mesas and development of a polarizing microscope

    International Nuclear Information System (INIS)

    Guenon, Stefan Alexander

    2011-01-01

    This thesis is divided into two parts. Concerning the first part: Motivated by the discovery of coherent Terahertz emission from large sized Bi_2Sr_2CaCu_2O_8 stacks of intrinsic Josephson Junctions by Ozyuzer et al., low-temperature laser scanning microscopy (LTSLM) was used to investigate similar samples. In LTSLM a focused laser beam at position (x,y) is heating the sample in its vicinity. Simultaneously the electrical resistance of the sample is monitored by 4- or 2-wire sensing. By blanking the laser beam and using lock-in technique the response, i.e., the beam induced voltage change ΔV(x,y) to the heat distribution at the location (x,y) can be detected. Scanning the laser beam and mapping the response ΔV(x,y) leads to the so-called voltage image of the sample. Depending on the sample under investigation this voltage image is a map of all kinds of physical properties. This experimental technique was used with two objectives. First, the plasma wave causing the THz emission should be imaged, and second, the phenomenon of self-heating, which is considerable for large mesas, should be investigated. Indeed, it was possible to map a standing wave pattern at bias points with low currents, where Ozyuzer et al. have detected THz radiation. At high currents, where the back bending in the current-voltage relation indicates strong self heating, a feature appears in the LTSLM voltage images, which was clearly identified as an electro-thermal domain (hot spot) created by the temperature dependence of the c-axis resistivity in the Bi_2Sr_2CaCu_2O_8-mesa. In this bias interval a standing wave pattern appears beside this feature at certain bias points. In order to investigate whether this standing wave pattern is associated with THz emission, a simple interferometer with a bolometer as detector was realized. With the help of this set-up it was possible to detect THz radiation from mesas at high bias currents (hot spot bias regime) and to determine its frequency. It could be

  1. Modelling the evolution of solar-mass stars with a range of metallicities using MESA

    Directory of Open Access Journals (Sweden)

    Jones E.F.

    2015-01-01

    Full Text Available The nuclides 1,2H, 3,4He, 7Li, 7Be, 8B, 12,13C, 13-15N, 14-18O, 17-19F, 18-22Ne, 22Mg, and 24Mg were used in the code package MESA (Modules for Experiments in Stellar Astrophysics[Paxton] to model a one-solar-mass star with a range of metallicities, z, from 0 to 0.1. On HR diagrams of each star model’s luminosity and effective temperature from before zero-age main sequence (pre-ZAMS to white dwarf, oscillations were noted in the horizontal branch at intervals from z = 0 to 0.0070. At z, = 0, the calculated stellar lifetime is 6.09x109 years. The calculated lifetime of the model stars increases to a maximum of 1.25x1010 years at z = 0.022 and then decreases to 2.59x109 years at z = 0.1. A piecewise fit of the model lifetimes vs. metallicity was obtained.

  2. Core drilling provides information about Santa Fe Group aquifer system beneath Albuquerque's West Mesa

    Science.gov (United States)

    Allen, B.D.; Connell, S.D.; Hawley, J.W.; Stone, B.D.

    1998-01-01

    Core samples from the upper ???1500 ft of the Santa Fe Group in the Albuquerque West Mesa area provide a first-hand look at the sediments and at subsurface stratigraphic relationships in this important part of the basin-fill aquifer system. Two major hydrostratigraphic subunits consisting of a lower coarse-grained, sandy interval and an overlying fine-grained, interbedded silty sand and clay interval lie beneath the water table at the 98th St core hole. Borehole electrical conductivity measurements reproduce major textural changes observed in the recovered cores and support subsurface correlations of hydrostratigraphic units in the Santa Fe Group aquifer system based on geophysical logs. Comparison of electrical logs from the core hole and from nearby city wells reveals laterally consistent lithostratigraphic patterns over much of the metropolitan area west of the Rio Grande that may be used to delineate structural and related stratigraphic features that have a direct bearing on the availability of ground water.

  3. Summary of micrographic analysis of fracture coating phases on drill cores from Pahute Mesa, Nevada Test Site. Revision 1

    International Nuclear Information System (INIS)

    1998-12-01

    The flow path between Pahute Mesa and the groundwater discharge area in Oasis Valley (approximately 18 miles to the southwest) is of concern due to the relatively short travel distance between a recharge area where underground nuclear testing has been conducted and the off-site water users. Groundwater flow and transport modeling by IT Corporation (IT) has shown rapid tritium transport in the volcanic rock aquifers along this flow path. The resultant estimates of rapid transport were based on water level data, limited hydraulic conductivity data, estimates of groundwater discharge rates in Oasis Valley, assumed porosities, and estimated retardation rates. Many of these parameters are poorly constrained and may vary considerably. Sampling and analytical techniques are being applied as an independent means to determine transport rates by providing an understanding of the geochemical processes that control solute movement along the flow path. As part of these geochemical investigations, this report summarizes the analysis of fracture coating mineral phases from drill core samples from the Pahute mesa area of the Nevada Test Site (NTS). Archived samples were collected based on the presence of natural fractures and on the types and abundance of secondary mineral phases present on those fracture surfaces. Mineral phases present along fracture surfaces are significant because, through the process of water-rock interaction, they can either contribute (as a result of dissolution) or remove (as a result of precipitation or adsorption) constituents from solution. Particular attention was paid to secondary calcite occurrences because they represent a potential source of exchangeable carbon and can interact with groundwater resulting in a modified isotopic signature and apparent water age

  4. Phase I Hydrologic Data for the Groundwater Flow and Contaminant Transport Model of Corrective Action Unit 99: Rainier Mesa/Shoshone Mountain, Nevada Test Site, Nye County, Nevada, Revision 1

    Energy Technology Data Exchange (ETDEWEB)

    Nathan Bryant

    2008-05-01

    This document presents a summary and framework of the available hydrologic data and other information directly relevant to the development of the Rainier Mesa/Shoshone Mountain (RMSM) Corrective Action Unit (CAU) 99 groundwater flow models. Where appropriate, data and information documented elsewhere are briefly summarized with reference to the complete documentation.

  5. Constitución y actividades de la Mesa Provincial de Educación Ambiental en la provincia de Mendoza, Argentina.

    OpenAIRE

    Gabriela Diaz Isenrath; T Bilbao; Cristian Barbosa; Susana Lagos Silnik; Nora Marlia; Silvia Musso; Oscar Ongay Ugarteche; Mirta Zarate; Elba Alicia Pescetti de Cristaldo; Mauricio Bucheri; Flora Bertolotti

    2015-01-01

    La Educación Ambiental como actividad interdisciplinaria e interinstitucional, requiere de la planificación estratégica participativa, que permita la concreción de esfuerzos que suelen realizarse de manera aislada. Se expone el proceso llevado a cabo para la constitución de la Mesa de Educación Ambiental en la provincia de Mendoza, Argentina. A partir de la discusión sobre la problemática local del Cambio Climático y los requerimientos de  medidas de adaptación, se propone el espacio en el añ...

  6. Reseña de actividad: Mesa de debate “Políticas de Memoria, Verdad y Justicia: balances y perspectivas”

    OpenAIRE

    Paganini, Mariana; Zubillaga, Paula

    2016-01-01

    El pasado 1° de julio se llevó adelante la mesa de debate “Políticas de Memoria, Verdad y Justicia: balances y perspectivas”, en la sede del Rectorado de la Universidad Nacional de Tres de Febrero (UNTREF). El encuentro estuvo moderado por el Licenciado en Ciencias Políticas Matías Cerezo y contó con la participación del Doctor Daniel Rafecas, titular del Juzgado Criminal y Correccional Federal N° 3 de la Ciudad Autónoma de Buenos Aires, la Doctora en Sociología Elizabeth Jelin y el Doctor en...

  7. M.E.S.A, not Just a Seat at the Table: a Chicano Geology Student's Experience with Investigative Field Research

    Science.gov (United States)

    Ponce-Zepeda, M. M.

    2011-12-01

    The MESA (math, engineering, science achievement) program in California engages educationally disadvantaged students, primarily minority groups, providing the opportunity to excel in math and science and graduate with math-based degrees. MESA at East Los Angeles Community College selected me, a returning 24 year-old Chicano student, for the SCEC (Southern California Earthquake Center) summer internship at Utah State University (USU). The project coordinators assigned me to a group with three other undergraduate geology students from across the continent and from a variety of socioeconomic backgrounds to investigate geothermal systems in the Salton Trough and northern Utah. The peer-driven field work transformed student to investigator by forcing each participant to be responsible for the success of the entire group. In this environment, I rose to expectations along with my fellow interns managing a detailed field notebook, sampling, planning routes, level logger maintenance, and x-ray diffractometer analysis interpretation, among other things. Mentorship from and challenges proposed by the USU project advisor further built on this scaffolding of field experience. First hand fieldwork provides a battery of beneficial skills that many undergraduate geology students, especially at the two- year college level, rarely get an opportunity to participate in. The advantage of including non-traditional students from two- year colleges allows for a dynamic research network nationwide. Key sample collection by the East Los Angeles College (ELAC) Geology Club, a student- run club at an inner city community college, facilitated ongoing examination by collecting mud samples from gryphons and mudpots in the Salton Trough and testing temperature, pH levels, electrical conductivity, and total dissolved solids in the field. The samples were sent back to students at USU for further analysis. This collaborative effort is symbiotic as sharing the sampling responsibility allowed USU to

  8. Metamorphic distributed Bragg reflectors for the 1440–1600 nm spectral range: Epitaxy, formation, and regrowth of mesa structures

    International Nuclear Information System (INIS)

    Egorov, A. Yu.; Karachinsky, L. Ya.; Novikov, I. I.; Babichev, A. V.; Berezovskaya, T. N.; Nevedomskiy, V. N.

    2015-01-01

    It is shown that metamorphic In 0.3 Ga 0.7 As/In 0.3 Al 0.7 As distributed Bragg reflectors (DBRs) with a reflection band at 1440–1600 nm and a reflectance of no less than 0.999 can be fabricated by molecular beam epitaxy (MBE) on a GaAs substrate. It is demonstrated that mesa structures formed from metamorphic DBRs on a GaAs substrate can be regrown by MBE and microcavities can be locally formed in two separate epitaxial processes. The results obtained can find wide application in the fabrication of vertical-cavity surface-emitting lasers (VCSELs) with a buried tunnel junction

  9. Field tests of 2- and 40-tube condensers at the East Mesa Geothermal Test Site

    Energy Technology Data Exchange (ETDEWEB)

    Murphy, R.W.; Domingo, N.

    1982-05-01

    Two water-cooled isobutane condensers, one with 2 tubes and one with 40 tubes, were subjected to field tests at the East Mesa Geothermal Test Site to assess relative heat transfer performance in both surface evaporator and direct-contact evaporator modes. The five groups of tests established that field performance was below earlier laboratory-determined levels and that direct-contact evaporator mode performance was poorer than that for the surface evaporator mode. In all test situations, fluted condenser tubes performed better than smooth condenser tubes. Cooling water quality had no significant effect on performance, but brine preflash in the direct-contact mode did promote some relative performance improvement. Important implications of these results for binary geothermal power plants are that (1) working-fluid-side impurities can significantly degrade heat transfer performance of the power plant condensers and (2) provisions for minimizing such impurities may be required.

  10. Phase I Contaminant Transport Parameters for the Groundwater Flow and Contaminant Transport Model of Corrective Action Unit 99: Rainier Mesa/Shoshone Mountain, Nevada Test Site, Nye County, Nevada, Revision 1

    Energy Technology Data Exchange (ETDEWEB)

    Nathan Bryant

    2008-05-01

    This document presents a summary and framework of available transport data and other information directly relevant to the development of the Rainier Mesa/Shoshone Mountain (RMSM) Corrective Action Unit (CAU) 99 groundwater transport model. Where appropriate, data and information documented elsewhere are briefly summarized with reference to the complete documentation.

  11. Obtenção de medidas de imagens adquiridas em estereomiscroscópio e escaner de mesa = Measures obtained from images acquired by a stereomicroscope and a desktop scanner

    Directory of Open Access Journals (Sweden)

    Larentis, Naiara Leites

    2014-01-01

    Full Text Available Objetivo: Esse estudo teve por objetivo comparar medidas obtidas de imagens de secções dentárias adquiridas em estereomiscrópio e escâner de mesa, assim como determinar se existem diferenças entre os dois métodos. Métodos: Cinquenta dentes humanos extraídos foram seccionados no sentido mésio-distal. Cada secção foi fotografada em estereomicroscópio e digitalizada em escâner de mesa com resolução de 230 dpi. O programa Photoshop foi utilizado para obter medidas verticais e horizontais das imagens de cada secção dentárias, adquiridas por ambos os métodos. Foram repetidas as medidas em 20% das amostras, selecionadas randomicamente. Resultados: As medidas iniciais e as repetidas apresentaram correlação positiva e o teste t para amostras pareadas não revelou diferença significativa (a=5% entre elas. A média das medidas e os devios-padrão foram: horizontal, estereomicroscópio 8,89 mm±4,30 mm e escâner 8,89 mm±4,52 mm; vertical, estereomicroscópio 4,42 mm±2,19 mm e escâner 4,43 mm±2,19 mm. Os resultados do teste t para amostras pareadas (a=5% não mostrou nenhuma diferença significativa entre os dois métodos para as medidas horizontais (p=0,685 e verticais (p=0,299. Conclusão: O escâner de mesa pode ser usado substituindo o estereomicroscópio na aquisição de imagens de secções dentárias para a obtenção de medidas verticais e horizontais

  12. Adecuaciones al programa de Tenis de Mesa Adaptado a niños con síndrome de Down de la escuela “Carlos Rodríguez Cariaga” de Camaguey

    Directory of Open Access Journals (Sweden)

    Carlos Alberto Govea Macías

    2007-03-01

    Full Text Available Los síndromes de Down presentan deficiencias en la adquisición de hábitos y habilidades motrices así como limitaciones desde el punto de vista psicomotriz, por lo que se asume la siguiente interrogante, ¿Cómo contribuir al desarrollo psicomotriz de los niños con síndrome de Down de la escuela “Carlos Rodríguez Cariaga”? y se propone como objetivo aplicar el Tenis de Mesa adaptado para mejorar la psicomotricidad de dichos alumnos en la escuela “Carlos Rodríguez Cariaga”. De una población de 10 niños, se escogió una muestra intencional de cuatro para un 40%, dos hembras y dos varones, sus edades oscilan entre 8-10 años y uno con cardiopatía congénita, los mismos fueron los de mejores resultados en el diagnóstico de los indicadores psicomotrices, todos con diagnóstico de RMMA, a los que se les aplicaron adecuaciones al programa de Tenis de Mesa Adaptado durante 10 semanas, tres días a la semana de 3:00 - 5:00 p.m. Para darle validez científica a la investigación se utilizaron métodos científicos, teóricos, empíricos y estadísticos los que permitieron concluir que en el diagnóstico todas las habilidades estaban como malas al igual que los indicadores psicomotrices, la coordinación dinámica general, el equilibrio dinámico y la sincinesis. Con la aplicación del programa de Tenis de Mesa adaptado se logró la adquisición y desarrollo de las habilidades y mejorar los indicadores psicomotrices estudiados, por lo que se recomienda aplicar las adecuaciones aquí propuestas para enriquecer el programa existente.

  13. Propagação de Vitis spp. pela enxertia de mesa utilizando diferentes porta-enxertos e auxinas

    Directory of Open Access Journals (Sweden)

    Murillo de Albuquerque Regina

    2012-09-01

    Full Text Available A enxertia de mesa constitui-se, hoje, uma técnica alternativa de multiplicação da videira. No Brasil, esta técnica começou a ser empregada em escala comercial a partir dos anos 2000, mas diversas etapas da produção foram adaptadas de conhecimentos gerados no Hemisfério Norte, sem experimentação local. O emprego de auxinas é fundamental em algumas etapas do processo, como na formação do calo e no enraizamento, podendo afetar substancialmente as taxas de pegamento das mudas. Por outro lado, dentro da gama de porta-enxertos de uso corrente na viticultura nacional, a aptidão ao pegamento das mudas por esta técnica é variável e carente de experimentação regional. Neste sentido, este estudo testou diferentes parafinas de enxertia, enriquecidas ou não com auxinas, e diferentes porta-enxertos para um grupo variável de cultivares de videiras. Os experimentos foram realizados no Núcleo Tecnológico EPAMIG Uva e Vinho, em Caldas-MG, empregando a técnica de enxertia de mesa com estratificação em água e repicagem dos enxertos em canteiros a céu aberto. A parafina enriquecida com auxina mostrou-se mais indicada para a enxertia, ao passo que o emprego do AIB para enraizamento dos porta-enxertos não influenciou positivamente na produção das mudas. O pegamento médio de enxertia para os diferentes porta-enxertos foi variável em função dos anos de estudo, mas situou-se dentro dos valores normais próximos aos 55 % para esta técnica, à exceção da cultivar 420 A, que não se mostrou adaptada à esta técnica de propagação para a região em estudo.

  14. The structural and electrical characterisation of SiGe heterostructures deposited on strain relaxed virtual substrates

    International Nuclear Information System (INIS)

    Hammond, R.

    1998-09-01

    The influence of lateral dimensions on the relaxation mechanism and the resulting effect on the surface topography of limited-area, linearly graded Si 1-x Ge x virtual substrates has been investigated for the first time. A dramatic change in the relaxation mechanism of such buffer layers has been observed for depositions on Si mesa pillars of lateral dimensions of 10μm and below. For such depositions, misfit dislocations are able to extend, unhindered, and terminate at the edges of the growth zone. In this manner, orthogonal misfit dislocation interactions are avoided, yielding a surface free of the problematic surface cross-hatch roughening. However, as the lateral dimension of the growth zone is increased to 20μm, orthogonal misfit interactions occur and relaxation is dominated by the Modified Frank-Read (MFR) multiplication mechanism. The resulting surface morphology shows a pronounced surface cross-hatch roughening. It is proposed that such cross-hatch roughening is a direct consequence of the cooperative stress fields associated with the MFR mechanism. It is postulated that the method of limited-area, linearly graded buffer layers provides a unique opportunity, by which 'ideal' virtual substrates, free of surface cross-hatch and threading dislocations, may be produced to any Ge content. In addition, a unique method by which the electrical performance of low temperature, strained layer depositions may be optimised is discussed. The method relies on the elimination of as-grown lattice imperfections via a post growth thermal anneal treatment. A 25-fold increase in low temperature hole mobility of a Si 0.5 Ge 0.5 /Si 0.7 Ge 0.3 heterostructure has been demonstrated using a 30minute, 750 deg C in-situ, post growth anneal. (author)

  15. EL CULTIVO DE LA UVA DE MESA EN EL MEDIO VINALOPÓ: RECURSOS HÍDRICOS Y RIEGOS LOCALIZADOS DE ALTA FRECUENCIA

    Directory of Open Access Journals (Sweden)

    Alfredo Ramón Morte

    1990-01-01

    Full Text Available Aridez y escasez de recursos hídricos han propiciado la existencia en el Vinalopó Medio de una extensa superficie regada, sometida a la explotación de acuíferos subterráneos. La ampliación descontrolada del cultivo de la uva de mesa unida a un irracional uso del agua, comprometen la propia viabilidad económica del sector agrario en la zona. La utilización de sistemas de riego localizado de alta frecuencia y la ampliación de la capacidad de embalse, forman parte de un proceso de renovación y una posible solución al problema.

  16. Geochronology and geochemistry of the granites from the Zhuxi W-Cu ore deposit in South China: Implication for petrogenesis, geodynamical setting and mineralization

    Science.gov (United States)

    Pan, Xiaofei; Hou, Zengqian; Zhao, Miao; Chen, Guohua; Rao, Jianfeng; Li, Yan; Wei, Jin; Ouyang, Yongpeng

    2018-04-01

    The giant Zhuxi tungsten deposit is located in the Taqian-Fuchun Ore Belt in northeastern Jiangxi province, and genetically associated with the Zhuxi granitic stocks and dykes. Three mineralization-related granites including granite porphyry dykes (GP), biotite granitic stocks (BG), and white granitic dykes (WG), were identified in the Zhuxi deposit. SHRIMP zircon U-Pb analysis for the three granitic rocks present ages ranging from 153.5 ± 1.0 Ma to 150.4 ± 1.0 Ma. The BG mainly contains quartz, microcline, albite, biotite and muscovite with minor accessory minerals including zircon, apatite, monazite, Ti/Fe oxides, and dolerite. However, the WG is mainly composed of quartz, microcline and albite with minor muscovite and accessory minerals. The GP is a medium-grained porphyritic granite and its phenocrysts include quartz, alkali feldspar, muscovite and plagioclase. All the Zhuxi granites have high SiO2 content (71.97 wt%-81.19 wt%) and total alkali (3.25 wt%-9.42 wt%), and their valid aluminum saturation index (ASI) values show a wide range of 1.03 to 2.49. High Rb/Sr ratios, low Sr content (data suggest that these highly fractionated I-S transform-type granites were originated from magmas which showed affinity with the Proterozoic continent and the Shuangqiaoshan Group and little mantle contribution was involved during the generation of Zhuxi granitic rocks. Extreme fractional crystallization resulted in further enrichment of tungsten in the evolved granitic magma. New data, presented together with previously published data, suggest that the Zhuxi granitic complex was likely to be formed during lithospheric compression setting during the late Jurassic to early Cretaceous. The biotite granite stock predominately contributed to the production of skarn alteration and mineralization, followed by the white granite dyke; the granite porphyry dykes have little effect.

  17. Regional setting and geochronology of the Late Cretaceous Banatitic Magmatic and Metallogenetic Belt

    Science.gov (United States)

    Ciobanu, Cristiana L.; Cook, Nigel J.; Stein, Holly

    2002-08-01

    The 1,500-km-long Banatitic Magmatic and Metallogenetic Belt (BMMB) of Romania, Serbia and Bulgaria is a complex calc-alkaline magmatic arc of Late Cretaceous age. It hosts a variety of magmatic-hydrothermal Cu, Au, Mo, Zn, Pb and Fe deposits, including Europe's only world-class porphyry-copper deposits. Regional metallogeny can be linked to subduction of the Vardar Ocean during the Late Cretaceous, as part of the closure of the Neotethys Ocean that had separated Europe and Africa in the Mesozoic. Porphyry Cu-(Au)-(Mo) and intimately associated epithermal massive sulphides dominate in the central segments of the belt in southernmost Banat (Romania), Serbia and north-west Bulgaria. These districts are the economically most important today, including major active Cu-Au mines at Moldova Nouă in Romania, Majdanpek, Veliki Krivelj and Bor in Serbia, and Elatsite, Assarel and Chelopech in Bulgaria. More numerous (and mostly mined in the past) are Fe, Cu and Zn-Pb skarns, which occur mainly at the two ends of the belt, in Eastern Bulgaria and in Romania. This paper summarises some of the deposit characteristics within the geodynamic framework of terminal Vardar subduction. Heterogeneous terranes of the belt, including the Apuseni Mountains at the western end, are aligned parallel to the Vardar front following continental collision of the Dacia and Tisza blocks. All available geochronological data (numerous K-Ar and some U-Pb and Re-Os ages) are compiled, and are complemented by a new high-precision Re-Os date for the Dognecea skarn deposit, south-west Romania (76.6±0.3 Ma). These data indicate that magmatism extended over at least 25 million years, from about 90 to 65 Ma in each segment of the belt. Within Apuseni Mountains and Banat, where magma emplacement was related to syn-collisional extension in the orogenic belt of Carpathians, ore formation seems to be restricted in time and maybe constrained by a shared tectonic event.

  18. Analysis of tracer responses in the BULLION Forced-Gradient Experiment at Pahute Mesa, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    Paul W. Reimus; Marc J. Haga

    1999-10-01

    This report presents an analysis of the tracer data from the BULLION forced-gradient experiment (FGE) conducted on Pahute Mesa at the Nevada Test Site from June 2, 1997 through August 28, 1997, for the Underground Test Area (UGTA) Program. It also serves to document the polystyrene microsphere data from the FGE. The FGE involved the injection of solute and colloid tracers into wells ER-20-6 No. 1 and ER-20-6 No. 2 while ER-20-6 No. 3 was pumped at approximately 116 gallons per minute (gpm). The experimental configuration and test design are described briefly in this report; more details are provided elsewhere (IT, 1996, 1997, 1998). The tracer responses in the various wells yielded valuable information about transport processes such as longitudinal dispersion, matrix diffusion and colloid transport in the hydrogeologic system in the vicinity of the BULLION nuclear test cavity. Parameter values describing these processes are derived from the semi-analytical model interpretations presented in this report. A companion report (IT, 1998) presents more detailed numerical modeling interpretations of the solute tracer responses.

  19. Environmental restoration technology programs at Mesa State College: A strategic look at manpower needs

    International Nuclear Information System (INIS)

    Harrison, R.J.; Emilia, D.A.

    1991-01-01

    The environmental cleanup of Department of Energy (DOE) sites within the next 30 years requires strategic planning to ensure adequate manpower is available when needed. Manpower needs projections within DOE have been based on analyses of current industry trends that indicate a substantial shortage of scientists and engineers. This paper explores the idea that the manpower requirements of DOE's environmental restoration program are not yet fully realized by most sites, which are currently in the predecisional work phase. Experience at the Grand Junction Projects Office (GJPO), which has had environmental restoration as it primary mission for about 10 years, shows that in the postdecisional phases the manpower need for scientists and engineers decreases while the manpower need for technologists in technical, management, and support roles increases. The GJPO, with Mesa State College in Grand Junction, Colorado, has developed an Environmental Restoration Associate degree program based on a strategic look at its manpower needs. This program receives start-up funding from DOE and has received donations in the million dollar range from various industry and state government partners

  20. Analysis of tracer responses in the BULLION Forced-Gradient Experiment at Pahute Mesa, Nevada

    International Nuclear Information System (INIS)

    Reimus, Paul W.; Haga, Marc J.

    1999-01-01

    This report presents an analysis of the tracer data from the BULLION forced-gradient experiment (FGE) conducted on Pahute Mesa at the Nevada Test Site from June 2, 1997 through August 28, 1997, for the Underground Test Area (UGTA) Program. It also serves to document the polystyrene microsphere data from the FGE. The FGE involved the injection of solute and colloid tracers into wells ER-20-6 No. 1 and ER-20-6 No. 2 while ER-20-6 No. 3 was pumped at approximately 116 gallons per minute (gpm). The experimental configuration and test design are described briefly in this report; more details are provided elsewhere (IT, 1996, 1997, 1998). The tracer responses in the various wells yielded valuable information about transport processes such as longitudinal dispersion, matrix diffusion and colloid transport in the hydrogeologic system in the vicinity of the BULLION nuclear test cavity. Parameter values describing these processes are derived from the semi-analytical model interpretations presented in this report. A companion report (IT, 1998) presents more detailed numerical modeling interpretations of the solute tracer responses

  1. A preliminary guidebook for identifying stratigraphic contacts at the Nevada Test Site

    International Nuclear Information System (INIS)

    Pawloski, G.A.; McKague, H.L.; Wagoner, J.L.; McKinnis, W.B.

    1992-01-01

    Lithologic variation, regional depositional trends, and the lack of written guidelines have resulted in inconsistencies in the recognition of stratigraphic contacts in drill holes at the Nevada Test Site (NTS). Stratigraphic identification, based on mineralogy of discrete samples, can be augmented by geophysical logs and downhole movies to more accurately and consistently locate contacts between units. Criteria are established for locating the base of the Pahute Mesa ash-flow tuff, the top of the Ammonia Tanks ash-flow tuff, the top of the Ammonia Tanks bedded tuff, and the top and the base of the Rainier Mesa Tuff

  2. Propiedad y empresa minera en la Mesa centro-norte de México Guanajuato, San Luís Potosí y Zacatecas, 1880-1910 /

    OpenAIRE

    Gámez Rodríguez, Moisés

    2005-01-01

    Consultable des del TDX Títol obtingut de la portada digitalitzada En la tesis se abordan los procesos de integración y diferenciación sobre la propiedad y la empresa en la Mesa Centro-norte de México (Guanajuato, San Luis Potosí y Zacatecas) circunscritos en el contexto nacional e internacional, durante el periodo de 1880-1910. La hipótesis general es que la demanda internacional de metales preciosos y de minerales industriales estimuló la producción, la creación de un marco institucio...

  3. U.S. Geological Survey investigations in connection with the dining car event, U12e.18 tunnel, rainier mesa, Nevada test site

    International Nuclear Information System (INIS)

    1978-06-01

    The Dining Car event was a Defense Nuclear Agency nuclear weapons test located in the U12e.18 drift of the E-tunnel complex, central Rainier Mesa, Area 12, Nevada Test Site. The main drift and bypass drift were mined in zeolitized tuff to a total length of 544 m (1,785 ft). The overburden thickness above the experiment is approximately 396 m (1,300 ft) in the U12e.18 area. The pre-Tertiary surface, which is most probably quartzite in this area, is located approximately 243.8 to 274.3 m (800 to 900 ft) below tunnel level. Site geology and geophysical investigations were made in one vertical and two horizontal drill holes prior to mining of the U12e.18 drift. Electric logs in the two horizontal holes indicate no extensive zones of argillization which might create problems in tunnelling. Geophysical logs in the vertical exploratory hole suggest that the tuff is saturated at a depth of about 244 m (800 ft). Electric logs in all three holes show a pronounced signature in tunnel bed 4J. Seismic velocities obtained in the tunnel after mining compare favorably with sonic velocities obtained in one hole by means of a sonic probe, indicating that the bulk geologic structure is not significant in affecting seismic-wave propagation. This condition is not always observed in such comparisons. A repeat seismic survey in the tunnel showed no change in seismic velocity 4 months after mining. In situ stresses determined by the overcore technique are within experience for the Rainier Mesa tunnel complex

  4. Multiple Mesozoic mineralization events in South China—an introduction to the thematic issue

    Science.gov (United States)

    Hu, Rui-Zhong; Zhou, Mei-Fu

    2012-08-01

    Mesozoic mineral deposits in South China include world-class deposits of W, Sn and Sb and those that provide the major sources of Ta, Cu, Hg, As, Tl, Pb, Zn, Au and Ag for the entire country. These deposits can be classified into polymetallic hydrothermal systems closely related to felsic intrusive rocks (Sn-W -Mo granites, Cu porphyries, polymetallic and Fe skarns, and polymetallic vein deposits) and low-temperature hydrothermal systems with no direct connection to igneous activities (MVT deposits, epithermal Au and Sb deposits). Recent studies have shown that they formed in the Triassic (Indosinian), Jurassic-Cretaceous (Early Yanshanian), and Cretaceous (Late Yanshanian) stages. Indosinian deposits include major MVT (Pb-Zn-Ag) deposits and granite-related W-Sn deposits. Early Yanshanian deposits are low-temperature Sb-Au and high-temperature W-Sn and Cu porphyry types. Many Late Yanshanian deposits are low-temperature Au-As-Sb-Hg and U deposits, and also include high-temperature W-Sn polymetallic deposits. The formation of these deposits is linked with a specific tectonothermal evolution and igneous activities. This special issue brings together some of the latest information in eight papers that deal with the origins and tectonic environments of mineral deposits formed in these stages. We anticipate that this issue will stimulate more interests in these ore deposits in South China.

  5. Mineralogy, fluid inclusion petrography, and stable isotope geochemistry of Pb-Zn-Ag veins at the Shizhuyuan deposit, Hunan Province, southeastern China

    Science.gov (United States)

    Wu, Shenghua; Mao, Jingwen; Yuan, Shunda; Dai, Pan; Wang, Xudong

    2018-01-01

    The Shizhuyuan polymetallic deposit is located in the central part of the Nanling region, southeastern China, and consists of proximal W-Sn-Mo-Bi skarns and greisens and distal Pb-Zn-Ag veins. The sulfides and sulfosalts in the distal veins formed in three distinct stages: (1) an early stage of pyrite and arsenopyrite, (2) a middle stage of sphalerite and chalcopyrite, and (3) a late stage of galena, Ag-, Sn-, and Bi-bearing sulfides and sulfosalts, and pyrrhotite. Combined sulfide and sulfosalt geothermometry and fluid inclusion analyses indicate that the early stage of mineralization occurred at a temperature of 400 °C and involved boiling under hydrostatic pressure ( 200 bar), with the temperature of the system dropping during the late stage to 200 °C. Laser Raman analysis indicates that the fluid inclusions within the studied minerals are dominated by H2O, although some contain carbonate solids and CH4 gas. Vein-hosted sulfides have δ34S values of 3.8-6.3‰ that are interpreted as indicative of a magmatic source of sulfur. The mineralization process can be summarized as follows: an aqueous fluid exsolved on final crystallization of the Qianlishan pluton, ascended along fracture zones, cooled to <400 °C, and boiled under hydrostatic conditions, and with decreasing temperature and sulfur fugacity, sulfide and sulfosalt minerals precipitated successively from the Ag-Cu-Zn-Fe-Pb-Sb-As-S-bearing fluid system.

  6. Comparison of Mesa and Device Diameter Variation in Double Wafer-Fused Multi Quantum-Well, Long-Wavelength, Vertical Cavity Surface Emitting Lasers

    International Nuclear Information System (INIS)

    Menon, P.S.; Kandiah, K.; Burhanuddin Yeop Majlis; Shaari, S.

    2011-01-01

    Long-wavelength vertical-cavity surface-emitting lasers (LW-VCSELs) have profound advantages compared to traditional edge-emitting lasers offering improved properties with respect to mode selectivity, fibre coupling, threshold currents and integration into 2D arrays or with other electronic devices. Its commercialization is gaining momentum as the local and access network in optical communication system expand. Numerical modeling of LW-VCSEL utilizing wafer-fused InP-based multi-quantum wells (MQW) and GaAs-based distributed Bragg reflectors (DBRs) is presented in this paper. Emphasis is on the device and mesa/pillar diameter design parameter comparison and its effect on the device characteristics. (author)

  7. Geologic Map of the San Luis Quadrangle, Costilla County, Colorado

    Science.gov (United States)

    Machette, Michael N.; Thompson, Ren A.; Drenth, Benjamin J.

    2008-01-01

    The map area includes San Luis and the primarily rural surrounding area. San Luis, the county seat of Costilla County, is the oldest surviving settlement in Colorado (1851). West of the town are San Pedro and San Luis mesas (basalt-covered tablelands), which are horsts with the San Luis fault zone to the east and the southern Sangre de Cristo fault zone to the west. The map also includes the Sanchez graben (part of the larger Culebra graben), a deep structural basin that lies between the San Luis fault zone (on the west) and the central Sangre de Cristo fault zone (on the east). The oldest rocks exposed in the map area are the Pliocene to upper Oligocene basin-fill sediments of the Santa Fe Group, and Pliocene Servilleta Basalt, a regional series of 3.7?4.8 Ma old flood basalts. Landslide deposits and colluvium that rest on sediments of the Santa Fe Group cover the steep margins of the mesas. Rare exposures of the sediment are comprised of siltstones, sandstones, and minor fluvial conglomerates. Most of the low ground surrounding the mesas and in the graben is covered by surficial deposits of Quaternary age. The alluvial deposits are subdivided into three Pleistocene-age units and three Holocene-age units. The oldest Pleistocene gravel (unit Qao) forms extensive coalesced alluvial fan and piedmont surfaces, the largest of which is known as the Costilla Plain. This surface extends west from San Pedro Mesa to the Rio Grande. The primary geologic hazards in the map area are from earthquakes, landslides, and localized flooding. There are three major fault zones in the area (as discussed above), and they all show evidence for late Pleistocene to possible Holocene movement. The landslides may have seismogenic origins; that is, they may be stimulated by strong ground shaking during large earthquakes. Machette and Thompson based this geologic map entirely on new mapping, whereas Drenth supplied geophysical data and interpretations.

  8. Spontaneous potential and telluric measurements on Rainier Mesa relaed to the NPE

    Energy Technology Data Exchange (ETDEWEB)

    Sweeney, J.J. [Lawrence Livermore National Lab., CA (United States)

    1994-12-31

    We made measurements of spontaneous potential (SP) on Rainier Mesa to see if changes in subsurface electrical properties of rock related to the Non-Proliferation Experiment (NPE) explosion can be detected at the surface. A north-south line, repeated 3 times and running within 50 m of surface ground zero (SGZ) of Hunter`s Trophy and within 20 m of SGZ of the NPE, was measured before and after the NPE. An east-west line, with one end within 20 m of SGZ of the NPE was also run before and after the NPE. High values of surface potential along the north-south line in the vicinity of the NPE apparently moved northward after the detonation. A similar change was not noted on the east-west line. A telluric line (0.025-0.1 Hz and 8.0 Hz) was also run prior to the NPE along the same north-south line as the SP measurement, but farther to the west of SGZ for Hunter`s Trophy. There is a prominent high in the 8 Hz data in the northern part that may be related to a former nuclear test, but it could also be related to local geology. Results from these geophysical methods, while showing some promise for use in an on-site monitoring regime, also emphasize the need for repeatable background reference data.

  9. Mesa 10 x 20 NTMS area, Arizona: data report (abbreviated)

    International Nuclear Information System (INIS)

    Cook, J.R.; Koller, G.R.

    1980-09-01

    Surface sediment samples were collected at 713 sites, at a target sampling density of one site per 13 square kilometers. Ground water samples were collected at 365 sites. Neutron activation analysis results are given for uranium and 16 other elements in sediments, and for uranium and 9 other elements in ground water. Mass spectrometry results are given for helium in ground water. Field measurements and observations are reported for each site. Analytical data and field measurements are presented in tables and maps. Data from ground water and surface water sites include (1) water chemistry measurements (pH, conductivity, and alkalinity) (2) physical measurements where applicable (water temperature, well description, and scintillometer reading) and (3) elemental analyses (U, Al, Br, Cl, Dy, F, Mg, Mn, Na, and V). Helium analyses are given for ground water. Data from sediment sites include (1) stream water chemistry measurements from sites where water was available and (2) elemental analyses for sediment samples (U, Th, Hf, Al, Ce, Dy, Eu, Fe, La, Lu, Mn, Sc, Sm, Na, Ti, V, and Yb). Sample site descriptors (stream characteristics, vegetation, etc.) are also tabulated. Areal distribution maps, histograms, and cumulative frequency plots for most elements; U/Th, U/Hf, U/(Th+Hf), and U/La ratios; and scintillometer readings at sediment sample sites are included on the microfiche. The maximum uranium concentration found in sediments in the Mesa quadrangle was 36.6 ppM. The mean of the logarithms of the uranium concentrations was 0.58, which is equivalent to 3.8 ppM. High uranium concentrations are related to Precambrian granites; however, high log (U/Th) values appear to be related to Tertiary volcanic rocks

  10. Geochronology and petrogenesis of the Qibaoshan Cu-polymetallic deposit, northeastern Hunan Province: Implications for the metal source and metallogenic evolution of the intracontinental Qinhang Cu-polymetallic belt, South China

    Science.gov (United States)

    Yuan, Shunda; Mao, Jingwen; Zhao, Panlao; Yuan, Yabin

    2018-03-01

    The recently recognized Qinhang metallogenic belt (QHMB) is an economically important intracontinental Mesozoic porphyry-skarn Cu-polymetallic metallogenic belt in South China. However, the origin of the ore-bearing magma and the major factors controlling the different metal assemblages in the QHMB are still unclear. The Qibaoshan deposit is a large Cu-Au-Pb-Zn-Ag-Fe deposit located at the juncture between the northern and central parts of the QHMB. In this study, new zircon U-Pb ages, Hf-O isotopic data, molybdenite Re-Os ages, and whole-rock geochemical data are combined to constrain the timing of the mineralization and the origin and petrogenesis of the ore-bearing porphyry in the Qibaoshan deposit. The ages obtained from both zircon U-Pb and molybdenite Re-Os dating fall in the Late Jurassic (between 152.7 and 148.3 Ma), revealing that this deposit is significantly younger than previously estimated (227-184 Ma). The Qibaoshan ore-bearing quartz porphyry shows variable negative zircon εHf(t) values (-14.8 to -5.5), high δ18O values (8.4 to 10.8‰), and high Mg# values (69.1 to 73.0), indicating that it formed via the partial melting of ancient crust triggered by the injection of mantle-derived magma. Zircon Hf-O isotopic modeling of the mixing of two extreme endmembers indicates that the magmatic source comprised 70-80% reworked ancient crustal components and 20-30% depleted mantle components. Based on comparisons with other ore-bearing porphyries in the QHMB, a magmatic source dominated by crust-derived material and relatively low oxygen fugacities (ΔFMQ -1.8 to ΔFMQ +0.8) was responsible for the high (Pb + Zn)/Cu ratio in the Qibaoshan deposit, and the Pb, Zn and Ag were mainly derived from the reworked ancient crust. Although four analyses of inherited Neoproterozoic zircons ( 800 Ma) have variable positive εHf(t) values (0.72 to 11.21), indicating that Neoproterozoic juvenile crust was involved in the formation of the Qibaoshan ore-bearing quartz

  11. Exposure to ambient air pollution and calcification of the mitral annulus and aortic valve: the multi-ethnic study of atherosclerosis (MESA).

    Science.gov (United States)

    Tibuakuu, Martin; Jones, Miranda R; Navas-Acien, Ana; Zhao, Di; Guallar, Eliseo; Gassett, Amanda J; Sheppard, Lianne; Budoff, Matthew J; Kaufman, Joel D; Michos, Erin D

    2017-12-21

    Long-term exposure to high ambient air pollution has been associated with coronary artery calcium (CAC), a marker of cardiovascular disease (CVD). Calcifications of left-sided heart valves are also markers of CVD risk. We investigated whether air pollution was associated with valvular calcification and its progression. We studied 6253 MESA participants aged 45-84 years who underwent two cardiac CT scans 2.5 years apart to quantify aortic valve calcium (AVC) and mitral annular calcium (MAC). CAC was included for the same timeframe for comparison with AVC/MAC. Ambient particulate matter AVC and MAC at baseline were 13% and 9% respectively, compared to 50% prevalence of CAC. The adjusted prevalence ratios of AVC and MAC for each 5 μg/m 3 higher PM 2.5 was 1.19 (95% CI 0.87, 1.62) and 1.20 (0.81, 1.77) respectively, and for CAC was 1.14 (1.01, 1.27). Over 2.5 years, the mean change in Agatston units/year for each 5 μg/m 3 higher PM 2.5 concentration was 0.29 (-5.05, 5.63) for AVC and 4.38 (-9.13, 17.88) for MAC, compared to 8.66 (0.61, 16.71) for CAC. We found no significant associations of NOx with AVC and MAC. Our findings suggest a trend towards increased 2.5-year progression of MAC with exposure to outdoor PM 2.5 , although this association could not be confirmed. Additional well-powered studies with longer periods of follow-up are needed to further study associations of air pollution with valvular calcium. Although MESA is not a clinical trial, this cohort is registered at ClinicalTrials.gov Identifier: NCT00005487; Date of registration May 25, 2000.

  12. Assimetria de transmissão de preço na comercialização da uva fina de mesa no Paraná: 1997 a 2011

    Directory of Open Access Journals (Sweden)

    Alexandre Florindo Alves

    2013-09-01

    Full Text Available O Paraná se destaca como um dos principais produtores de uva fina de mesa no Brasil, tendo como característica a presença de pequenos e médios produtores. O presente estudo objetiva analisar a assimetria na transmissão de preço entre os níveis produtor, atacado e varejo da uva fina de mesa no Paraná, no período de janeiro de 1997 a outubro de 2011. A metodologia empregada para verificar como ocorre a transmissão de preços entre os agentes foi o Vetor Autorregressivo (VAR. O modelo utilizado para mensurar Assimetria de Transmissão de Preços (ATP foi baseado na metodologia desenvolvida por Grififth e Piggott (1994. Os principais resultados foram: na análise de transmissão de preço ao varejo, o atacado apresentou um coeficiente de elasticidade maior do que o nível do produtor; o sentido unicausal atacado-varejo do teste de Granger é uma evidência de presença de informações assimétricas; e os acréscimos dos preços são transmitidos com mais rapidez do que os decréscimos, que, junto aos resultados do teste t de Griffith e Piggott (1994, comprova a existência de assimetria na transmissão de preços.

  13. U-Pb zircon geochronology of Mesoproterozoic postorogenic rocks and implications for post-Ottawan magmatism and metallogenesis, New Jersey Highlands and contiguous areas, USA

    Science.gov (United States)

    Volkert, R.A.; Zartman, R.E.; Moore, P.B.

    2005-01-01

    economic deposits of magnetite ?? U ?? Th ?? rare earth element (REE) and formed metasomatic calcic skarn bodies in marble and reactive carbonate rocks. Mineralization associated with this event overlaps the timing of pegmatite emplacement, suggesting a petrogenetic relationship. Coeval metallogeny at 975 to 950 Ma in the New York Hudson Highlands and 980 to 937 Ma in the Canadian Grenville Province implies that this event was widespread following the Ottawan phase of the Grenville Orogeny. ?? 2005 Elsevier B.V. All rights reserved.

  14. Tuning Surface Energy Landscapes in Metallic Quantum Films using Alkali Adsorbates

    Science.gov (United States)

    Khajetoorians, Alexander; Qin, Shengyong; Zhu, Wenguang; Eisele, Holger; Zhang, Zhenyu; Shih, Chih-Kang

    2008-03-01

    Quantum confinement shows a strong interplay with growth and kinetics in thin metal systems where the Fermi wavelength has a special relationship to the surface normal lattice constant. In the case of Pb/Si(111) systems, this relationship reveals an interesting thickness-dependent bilayer oscillation in the density of states and surface energy up to a phase. In this paper, we report on a novel effect: tuning of the energy landscape of a flat-top quantum Pb mesa using Cs adsorbates. Using STM/STS, we show that depositing Cs adsorbates on a thin Pb mesa promotes quantum stable Pb nanoislands on preferentially unstable thicknesses. Thickness-dependent nanoisland densities show a strong bilayer oscillation correlating with quantum stability. By modifying the Cs coverage on the mesa surface, we can tune the lateral size distribution of the nanoislands and the overall amplitude of the island density oscillation. Nanoisland formation is linked to a step decoration of Cs adatoms along the step edge of the nanoisland.

  15. Análise exploratória de adoçantes de mesa via espectroscopia no infravermelho (FTIR) e análise por componentes principais (ACP)

    OpenAIRE

    Tozetto,Adriana; Demiate,Ivo Mottin; Nagata,Noemi

    2007-01-01

    Nos últimos vinte anos, o consumo de alimentos diet e light tem aumentado sistematicamente, o que tem propiciado o constante desenvolvimento de produtos desse gênero. Grande ênfase tem sido dada àqueles produtos que substituem sacarose por edulcorantes de baixos conteúdos calóricos ou não calóricos. Seguindo esta tendência, adoçantes de mesa têm sido desenvolvidos variando-se amplamente o veículo e o tipo de edulcorante empregado. Neste trabalho, a análise de componentes principais associada ...

  16. The origin of the Tongkeng-Changpo tin deposit, Dachang metal district, Guangxi, China: clues from fluid inclusions and He isotope systematics

    Science.gov (United States)

    Minghai, Cai; Jingwen, Mao; Ting, Liang; Pirajno, Franco; Huilan, Huang

    2007-08-01

    Tongkeng-Changpo is the largest tin deposit within the giant Dachang polymetallic tin ore field in Guangxi, southern China, which is part of a large skarn system associated with Cretaceous granitoids. The Tongkeng-Changpo mineralization consists of veins and stockworks in the upper levels and replacement stratiform orebodies (mantos) at lower levels. Based on textural relationships, three major mineralizing stages can be recognized: stage I with cassiterite, sulphides, stannite, tourmaline, and quartz; stage II with cassiterite, sulphides, sulphosalts, quartz, and calcite; and stage III with calcite as the main phase. The study of fluid inclusions has shown that there are two main fluid types: CO2 and NaCl-H2O. Homogenization temperatures are 270 to 365°C, 210 to 240°C, and 140 to 190°C for stages I, II, and III, respectively. Salinities range from 1 to 7 wt.% NaCl equiv. in the early ore stage and 3 to 10 wt.% NaCl equiv. in the late stages. Laser Raman Spectroscopy indicates that the inclusion fluids in stages I and II were of carbono-aqueous composition, with minor amounts of CH4 and H2S, whereas those in stage III were aqueous. Helium isotopic analyses of inclusion fluids indicate that the 3He/4He ratios in the ore veins are in between 1.2 to 2.9 Ra (Ra = 1.4 × 10-6, modern atmospheric ratio), and range from 1.6 to 2.5 Ra in the stratiform orebodies. This range of 3He/4He ratios is significantly higher than that of crustal fluids (0.01-0.05 Ra). The similar characteristics of fluid inclusions and their He isotopic composition, as well as age constraints, indicate that the ore veins and stratiform orebodies of the Tongkeng-Changpo deposit formed from the same hydrothermal system, likely related to granite intrusions of the Mesozoic Yanshanian tectono-thermal event. In addition, the high R/Ra ratios indicate a mantle contribution in the ore fluids.

  17. Investigations on the Structure Tectonics, Geophysics, Geochemistry, and Hydrocarbon Potential of the Black Mesa Basin, Northeastern Arizona

    Energy Technology Data Exchange (ETDEWEB)

    Barker, Colin; Carroll, Herbert; Erickson, Richard; George, Steve; Guo, Genliang; Reeves,T.K.; Sharma, Bijon; Szpakiewicz, Michael; Volk, Len

    1999-04-27

    The U.S. Department of Energy (DOE) has instituted a basin-analysis study program to encourage drilling in underexplored and unexplored areas and increase discovery rates for hydrocarbons by independent oil companies within the continental United States. The work is being performed at the DOE's National Institute for Petroleum and Energy Research (NIPER) in Bartlesville, Oklahoma, by the Exploration and Drilling Group within BDM-Oklahoma (BDM), the manager of the facility for DOE. Several low-activity areas in the Mid-Continent, west, and southwest were considered for the initial study area (Reeves and Carroll 1994a). The Black Mesa region in northwestern Arizona is shown on the U.S. Geological Survey 1995 oil and gas map of the United States as an undrilled area, adapted from Takahashi and Gautier 1995. This basin was selected by DOE s the site for the initial NIPER-BDM survey to develop prospects within the Lower-48 states (Reeves and Carroll 1994b).

  18. The origin of elevated water levels in emplacement boreholes, Pahute Mesa, Nevada Test Site: A numerical study

    Energy Technology Data Exchange (ETDEWEB)

    Gardner, G.G.; Brikowski, T.H.

    1993-12-01

    The origin of elevated water levels in emplacement boreholes at Pahute Mesa, Nevada Test Site, is uncertain. If the water is from naturally perched aquifers, then presumed ``above water table`` weapons tests may directly impact the groundwater quality. The purpose of this study is to determine the probable source of the elevated water in boreholes by comparing modeled seepage of infiltrated drilling fluids, and the seepage from a simulated naturally perched aquifer with the observed water level history. In the model, large volumes of water are infiltrated, yet return flow of fluids back into the hole stops within three days after the end of drilling and is insufficient to produce observed standing water. Return flow is limited for two reasons: (1) the volume of the saturated rock next to the borehole is small; (2) pressure head gradient direct unsaturated flow away from the borehole. Simulation of seepage from a naturally perched aquifer readily reproduces the observed water levels.

  19. Phanerozoic continental growth and gold metallogeny of Asia

    Science.gov (United States)

    Goldfarb, Richard J.; Taylor, Ryan D.; Collins, Gregory S.; Goryachev, Nicolay A.; Orlandini, Omero Felipe

    2014-01-01

    ; and (8) Jurassic(?) ores on the margins of the Subumusu block in Myanmar and Malaysia. Circum-Pacific tectonism led to major orogenic gold province formation along the length of the eastern side of Asia between ca. 135 and 120 Ma, although such deposits are slightly older in South Korea and slightly younger in the Amur region of the Russian Southeast. Deformation related to collision of the Kolyma–Omolon microcontinent with the Pacific margin of the Siberia craton led to formation of 136–125 Ma ores of the Yana–Kolyma belt (Natalka, Sarylakh) and 125–119 Ma ores of the South Verkhoyansk synclinorium (Nezhdaninskoe). Giant ca. 125 Ma gold provinces developed in the Late Archean uplifted basement of the decratonized North China block, within its NE edge and into adjacent North Korea, in the Jiaodong Peninsula, and in the Qinling Mountains. The oldest gold-bearing magmatic–hydrothermal deposits of Asia include the ca. 485 Ma Duobaoshan porphyry within a part of the Tuva–Mongol arc, ca. 355 Ma low-sulfidation epithermal deposits (Kubaka) of the Omolon terrane accreted to eastern Russia, and porphyries (Bozshakol, Taldy Bulak) within Ordovican to Early Devonian oceanic arcs formed off the Kazakhstan microcontinent. The Late Devonian to Carboniferous was marked by widespread gold-rich porphyry development along the margins of the closing Ob–Zaisan, Junggar–Balkhash, and Turkestan basins (Amalyk, Oyu Tolgoi); most were formed in continental arcs, although the giant Oyu Tolgoi porphyry was part of a near-shore oceanic arc. Permian subduction-related deformation along the east side of the Indochina block led to ca. 300 Ma gold-bearing skarn and disseminated gold ore formation in the Truong Son fold belt of Laos, and along the west side to ca. 250 Ma gold-bearing skarns and epithermal deposits in the Loei fold belt of Laos and Thailand. In the Mesozoic Transbaikal region, extension along the basin margins subsequent to Mongol–Okhotsk closure was

  20. Colorado quartz: occurrence and discovery

    Science.gov (United States)

    Kile, D.E.; Modreski, P.J.; Kile, D.L.

    1991-01-01

    The many varieties and associations of quartz found throughout the state rank it as one of the premier worldwide localities for that species. This paper briefly outlines the historical importance of the mineral, the mining history and the geological setting before discussing the varieties of quartz present, its crystallography and the geological enviroments in which it is found. The latter include volcanic rocks and near surface igneous rocks; pegmatites; metamorphic and plutonic rocks; hydrothermal veins; skarns and sedimentary deposits. Details of the localities and mode of occurrence of smoky quartz, amethyst, milky quartz, rock crystal, rose quartz, citrine, agate and jasper are then given. -S.J.Stone

  1. Completion Report for Well ER-20-7: Corrective Action Units 101 and 102: Central and Western Pahute Mesa

    Energy Technology Data Exchange (ETDEWEB)

    NSTec Environmental Restoration

    2010-04-28

    Well ER-20-7 was drilled for the U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office in support of the Nevada Environmental Restoration Project at the Nevada Test Site, Nye County, Nevada. The well was drilled in June 2009 as part of the Pahute Mesa Phase II drilling program. The primary purpose of the well was to further investigate migration of radionuclides from the nearby, up-gradient TYBO and BENHAM underground nuclear tests, which originally was discovered at Well Cluster ER-20-5. This well also provided detailed hydrogeologic information in the Tertiary volcanic section that will reduce uncertainties within the Pahute Mesa-Oasis Valley hydrostratigraphic framework model. The main 44.45-centimeter hole was drilled to a depth of 681.8 meters and cased with 33.97-centimeter casing to 671.7 meters. The hole diameter was then decreased to 31.12 centimeters, and the well was drilled to total depth of 894.9 meters. The completion string, set to the depth of 890.0 meters, consists of 14.13-centimeter stainless-steel casing hanging from 19.37-centimeter carbon-steel casing. The 14.13-centimeter stainless-steel casing has one continuous slotted interval open to the Topopah Spring aquifer. Data collected during and shortly after hole construction include composite drill cuttings samples collected every 3.0 meters, sidewall core samples from 20 depth intervals, various geophysical logs, water quality (primarily tritium) measurements, and water level measurements. The well penetrated 894.9 meters of Tertiary volcanic rock, including two saturated welded-tuff aquifers. A fluid level measurement was obtained during open-hole geophysical well logging for the upper, Tiva Canyon, aquifer at the depth of 615.7 meters on June 19, 2009. The fluid level measured in the open hole on June 27, 2009,after the total depth was reached and the upper aquifer was cased off, was also at the depth of 615.7 meters. Preliminary field measurements indicated 1

  2. Completion Report for Wells ER-20-8 and ER-20-8#2 Corrective Action Units 101 and 102: Central and Western Pahute Mesa

    Energy Technology Data Exchange (ETDEWEB)

    NSTec Environmental Management

    2011-02-28

    Wells ER-20-8 and ER-20-8#2 were drilled for the U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office in support of the Nevada Environmental Restoration Project at the Nevada National Security Site (formerly Nevada Test Site), Nye County, Nevada. The holes were drilled in July and August 2009, as part of the Pahute Mesa Phase II drilling program. The primary purpose of these wells was to provide detailed hydrogeologic information in the Tertiary volcanic section that will help address uncertainties within the Pahute Mesa–Oasis Valley hydrostratigraphic framework model. They may also be used as long-term monitoring wells.

  3. Procesos de enmarcamiento y estrategias comunicativas de la Mesa Amplia Nacional Estudiantil en las protestas de 2011 en Colombia

    Directory of Open Access Journals (Sweden)

    Edwin Cruz Rodríguez

    2015-11-01

    Full Text Available This article analyzes the framing processes and the communication strategies of the student movement called Mesa Amplia Nacional Estudiantil during the 2011 protests against the higher education reform in Colombia. For this student movement, the main antagonist is the Government and it claims that education is a right and not a commodity; and a battle that goes beyond the university community and the student body is proposed in order to carry out several social and popular acts. The participants in this movement took into account the need to compete for the attention of the mass media, so they made it functional to their cause. They also felt the need to implement alternative forms of communication through virtual media and the need to create visible events that would become news and would help them to transmit their message.

  4. Armazenamento refrigerado da uva de mesa 'Romana' (A1105) cultivada sob cobertura plástica Cold storage of 'Romana' (A1105) table grape cultivated under plastic cover

    OpenAIRE

    Jorge Lulu; Josalba V. Castro; Mário J. Pedro Júnior

    2005-01-01

    A videira é uma das principais fruteiras cultivadas em todo o mundo e atualmente a preferência por uvas do tipo "sem sementes" ou "apirênicas" vem aumentando gradativamente no mercado interno brasileiro. A cultivar 'Romana' (A1105) tem mostrado grande potencial como nova alternativa de uva de mesa apirênica na região de Jundiaí - SP. No entanto, a qualidade dos cachos tem sido afetada pela ocorrência de chuvas na época da colheita, propiciando a incidência de rachaduras nas bagas ("cracking")...

  5. Report of the investigation of the accident at the MIDAS MYTH/MILAGRO Trailer Park on Rainier Mesa at Nevada Test Site on February 15, 1984

    International Nuclear Information System (INIS)

    1984-01-01

    Fourteen persons were injured, one fatally, when the ground upon which they were working collapsed, forming a subsidence crater in the recording trailer park of the MIDAS MYTH/MILAGRO nuclear weapons effects test on Rainier Mesa at the US Department of Energy's Nevada Test Site on February 15, 1984. Those persons injured were contractor and laboratory employees from Reynolds Electrical and Engineering Co., Inc. (REECo), Pan American World Services, Inc. (PANAM), and the Los Alamos National Laboratory (LANL). This report presents the results of an investigation into the causes, effects, and response to the accident. 42 figures

  6. Riotinto Iron Mining (Huelva); Mineria de hierro en Riotinto (Huelva)

    Energy Technology Data Exchange (ETDEWEB)

    Delgado Moninguez, A.; Moreno Bolanos, A.; Perez Macias, J. A.; Gemio del Rio, G.; Regalado Ortega, M. C.

    2011-07-01

    This paper deals with the mining of reworked gossan at Riotinto (Huelva, southwest Spain). The rock in question is a conglomerate formed by the erosion of gossan and its subsequent deposition in areas at some distance from its origin. In Roman times this mineral was used as construction material as well as for architectural decoration and possibly as an ore for making mining tools. This work focuses upon the exploitation of this mineral as an iron ore mined from the site known as Mesa Pinos or Alto de la Mesa by the Rio Tinto Company Ltd. between the last quarter of the 19th century and the first part of the 20th century. (Author) 42 refs.

  7. Geology, mineralogy and geochemistry of Ferezneh ferromanganese anomaly, east of Sangan mines complex, NE Iran

    Directory of Open Access Journals (Sweden)

    Nazi Mazhari

    2015-04-01

    Full Text Available Introduction The Ferezneh prospect area is one of the eastern anomalies of Khaf’s Sangan iron mine. The Sangan mines complex is located within the Khaf-Kashmar-Bardeskan volcano-plutonic and metallogenic belt in northeastern Iran. The Sangan mine is the largest Fe skarn in western Asia, having a proven reserve of over 1000 Mt iron ore @ 53% Fe (Golmohammadi et al., 2015 and consisting of three parts; western, central and eastern Sangan, each part including several anomalies. In this study, Ferezneh (North and West prospect area which is an eastern anomaly of the Sangan iron ore is discussed. Ferezneh anomaly is located in 60°36'7" - 60°34'27"E and 34°30'47" - 34°29'46"N, 35 km south of the city of Taybad, 10 km southeast of Karat and 1.5 km southwest of Ferezneh village. The purpose of this study was to prepare a geologic map for separation and identification of the intrusions, determining their relationships with mineralization, distinguishing the type of mineralization, mineralogy, petrology and geochemistry of the mineral deposits, and finally their relationship with other major Sangan’s deposits. Materials and methods In order to achieve the objectives of the study: 1- 140 thin sections of the intrusive rocks, marble limestone and dolomite, as well as 40 polished sections of ore were taken in an area of 9.5 km2. Mineralogy and mineralization studies were performed in the Economic Geology Laboratory of Ferdowsi University of Mashhad. 2- A few samples were selected for X-ray diffraction analysis in order to ensure accuracy of mineralogical studies and were sent to Binalood Laboratory in Tehran. 3- In addition to major and minor elements geochemistry study of the ores, 10 samples were sent to East Amitis Laboratory in Mashhad for XRF analysis and also to Canada S.G.S Laboratory for ICP-MS analysis. Discussion and results Mineralization in the Ferezneh prospect area was limited to iron and manganese oxides in the form of massive and

  8. Associations of Work Hours, Job Strain, and Occupation with Endothelial Function: The Multi-Ethnic Study of Atherosclerosis (MESA)

    Science.gov (United States)

    Charles, Luenda E.; Fekedulegn, Desta; Landsbergis, Paul; Burchfiel, Cecil M.; Baron, Sherry; Kaufman, Joel D.; Stukovsky, Karen Hinckley; Fujishiro, Kaori; Foy, Capri G.; Andrew, Michael E.; Roux, Ana V. Diez

    2014-01-01

    Objective To investigate associations of work hours, job control, job demands, job strain, and occupational category with brachial artery flow-mediated dilation (FMD) in 1,499 MESA participants. Methods FMD was obtained using high-resolution ultrasound. Mean values of FMD were examined across categories of occupation, work hours, and the other exposures using regression analyses. Results Occupational category was significantly associated with FMD overall, with blue-collar workers showing the lowest mean values: Management/professional=4.97±0.22%; sales/office=5.19±0.28%; services=4.73 ± 0.29%; and blue-collar workers=4.01±0.26% (adjusted P <0.001). There was evidence of effect modification by gender (interaction P=0.031): significant associations were observed among women (adjusted P =0.002) and nearly significant results among men (adjusted P=0.087). Other exposures were not significantly associated with FMD. Conclusions Differences in endothelial function may account for some of the variation in cardiovascular disease across occupational groups. PMID:25376409

  9. Geological site characterization for the proposed Mixed Waste Disposal Facility, Los Alamos National Laboratory

    International Nuclear Information System (INIS)

    Reneau, S.L.; Raymond, R. Jr.

    1995-12-01

    This report presents the results of geological site characterization studies conducted from 1992 to 1994 on Pajarito Mesa for a proposed Los Alamos National Laboratory Mixed Waste Disposal Facility (MWDF). The MWDF is being designed to receive mixed waste (waste containing both hazardous and radioactive components) generated during Environmental Restoration Project cleanup activities at Los Alamos. As of 1995, there is no Resource Conservation and Recovery Act (RCRA) permitted disposal site for mixed waste at the Laboratory, and construction of the MWDF would provide an alternative to transport of this material to an off-site location. A 2.5 km long part of Pajarito Mesa was originally considered for the MWDF, extending from an elevation of about 2150 to 2225 m (7060 to 7300 ft) in Technical Areas (TAs) 15, 36, and 67 in the central part of the Laboratory, and planning was later concentrated on the western area in TA-67. The mesa top lies about 60 to 75 m (200 to 250 ft) above the floor of Pajarito Canyon on the north, and about 30 m (100 ft) above the floor of Threemile Canyon on the south. The main aquifer used as a water supply for the Laboratory and for Los Alamos County lies at an estimated depth of about 335 m (1100 ft) below the mesa. The chapters of this report focus on surface and near-surface geological studies that provide a basic framework for siting of the MWDF and for conducting future performance assessments, including fulfillment of specific regulatory requirements. This work includes detailed studies of the stratigraphy, mineralogy, and chemistry of the bedrock at Pajarito Mesa by Broxton and others, studies of the geological structure and of mesa-top soils and surficial deposits by Reneau and others, geologic mapping and studies of fracture characteristics by Vaniman and Chipera, and studies of potential landsliding and rockfall along the mesa-edge by Reneau

  10. Geological site characterization for the proposed Mixed Waste Disposal Facility, Los Alamos National Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Reneau, S.L.; Raymond, R. Jr. [eds.

    1995-12-01

    This report presents the results of geological site characterization studies conducted from 1992 to 1994 on Pajarito Mesa for a proposed Los Alamos National Laboratory Mixed Waste Disposal Facility (MWDF). The MWDF is being designed to receive mixed waste (waste containing both hazardous and radioactive components) generated during Environmental Restoration Project cleanup activities at Los Alamos. As of 1995, there is no Resource Conservation and Recovery Act (RCRA) permitted disposal site for mixed waste at the Laboratory, and construction of the MWDF would provide an alternative to transport of this material to an off-site location. A 2.5 km long part of Pajarito Mesa was originally considered for the MWDF, extending from an elevation of about 2150 to 2225 m (7060 to 7300 ft) in Technical Areas (TAs) 15, 36, and 67 in the central part of the Laboratory, and planning was later concentrated on the western area in TA-67. The mesa top lies about 60 to 75 m (200 to 250 ft) above the floor of Pajarito Canyon on the north, and about 30 m (100 ft) above the floor of Threemile Canyon on the south. The main aquifer used as a water supply for the Laboratory and for Los Alamos County lies at an estimated depth of about 335 m (1100 ft) below the mesa. The chapters of this report focus on surface and near-surface geological studies that provide a basic framework for siting of the MWDF and for conducting future performance assessments, including fulfillment of specific regulatory requirements. This work includes detailed studies of the stratigraphy, mineralogy, and chemistry of the bedrock at Pajarito Mesa by Broxton and others, studies of the geological structure and of mesa-top soils and surficial deposits by Reneau and others, geologic mapping and studies of fracture characteristics by Vaniman and Chipera, and studies of potential landsliding and rockfall along the mesa-edge by Reneau.

  11. Aspectos alimentares e nutricionais dos usuários do "restaurante popular Mesa do Povo" Alimentary and nutritional aspects of users of the popular restaurant "Mesa do Povo"

    Directory of Open Access Journals (Sweden)

    Fábio Ângelo Lima Verde de Araújo

    2007-04-01

    Full Text Available O objetivo deste estudo foi averiguar aspectos alimentares e nutricionais dos usuários do "Restaurante Popular Mesa do Povo", situado em Fortaleza (CE, Brasil. Foram selecionados aleatoriamente 51 usuários, os quais foram submetidos à aplicação do inquérito alimentar recordatório 24 h e hábitos alimentares. A amostra foi estratificada por nível de sexo, nível de adequação. O consumo alimentar foi avaliado pelo Índice de Qualidade da Dieta e a adequação calórica, pela Pirâmide Alimentar Adaptada. Macro e micronutrientes tiveram adequações de acordo com "Dietary Reference Intakes". Após freqüentar o restaurante, 42,85% dos homens e 37,5% das mulheres declararam estar consumindo mais verduras. Dos problemas de saúde, a hipertensão arterial, associada ao diabetes mellitus, em 11,76%, e o diabetes mellitus, associado à doença cardiovascular, em 3,92%, foram os mais citados. Das calorias totais, verificou-se que a média de ingestão para homens foi de 2.278,9 calorias e, para as mulheres, 1.785,65 calorias, havendo diferença significativa entre os sexos. As inadequações de calorias evidenciaram-se em 31,4% abaixo e 49% acima do padrão recomendado. Constatou-se que 100% dos usuários estão com contribuição calórica de proteínas dentro do recomendado, sendo 94,12% para carboidratos, e 90,2% para os lipídios adequados à recomendação. Notou-se que o cálcio e tocoferol apresentaram a menor adequação na dieta dos usuários; no entanto, houve uma satisfatória adequação quanto ao teor médio em vitaminas e minerais. Faz-se necessário ajustar a operacionalização do atendimento por meio de critérios seletivos e adequados para atingir, em maior número, os usuários mais vulneráveis no aspecto nutricional e socioeconômico.The aim of this study was to examine alimentary, nutritional and socio-economic aspects of the users of Mesa do Povo, a popular restaurant in the city of Fortaleza, state of Ceará. Fifty

  12. Heterogenous Material Integration and Band Engineering With Type II Superlattice

    Science.gov (United States)

    2015-10-26

    ZnS is expected to be lower than in SiNx deposited under a plasma environment [64]. In addition, ZnS facilitates saturation of surface...SiNx passivation. This may be the result of the inferior quality of deposited ZnS film. The electrochemical sulphur (ECP) deposition and ammonium... ZnS ECP (NH 4 ) 2 S D ar k cu rr en t d en si ty ( A /c m 2 ) Mesa area (cm2) T = 77 K and V b = -0.1 V (a) 1E-5 1E-4 1E-3 0 10 20 (b)

  13. 20 CFR 703.306 - Kinds of negotiable securities that may be deposited; conditions of deposit; acceptance of deposits.

    Science.gov (United States)

    2010-04-01

    ... the Act in the amount fixed by the Office under the regulations in this part shall deposit any... deposited; conditions of deposit; acceptance of deposits. 703.306 Section 703.306 Employees' Benefits... negotiable securities that may be deposited; conditions of deposit; acceptance of deposits. A self-insurer or...

  14. Tsunami deposits

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2013-08-15

    The NSC (the Nuclear Safety Commission of Japan) demand to survey on tsunami deposits by use of various technical methods (Dec. 2011), because tsunami deposits have useful information on tsunami activity, tsunami source etc. However, there are no guidelines on tsunami deposit survey in JAPAN. In order to prepare the guideline of tsunami deposits survey and evaluation and to develop the method of tsunami source estimation on the basis of tsunami deposits, JNES carried out the following issues; (1) organizing information of paleoseismological record and tsunami deposit by literature research, (2) field survey on tsunami deposit, and (3) designing the analysis code of sediment transport due to tsunami. As to (1), we organize the information gained about tsunami deposits in the database. As to (2), we consolidate methods for surveying and identifying tsunami deposits in the lake based on results of the field survey in Fukui Pref., carried out by JNES. In addition, as to (3), we design the experimental instrument for hydraulic experiment on sediment transport and sedimentation due to tsunamis. These results are reflected in the guideline on the tsunami deposits survey and evaluation. (author)

  15. Tsunami deposits

    International Nuclear Information System (INIS)

    2013-01-01

    The NSC (the Nuclear Safety Commission of Japan) demand to survey on tsunami deposits by use of various technical methods (Dec. 2011), because tsunami deposits have useful information on tsunami activity, tsunami source etc. However, there are no guidelines on tsunami deposit survey in JAPAN. In order to prepare the guideline of tsunami deposits survey and evaluation and to develop the method of tsunami source estimation on the basis of tsunami deposits, JNES carried out the following issues; (1) organizing information of paleoseismological record and tsunami deposit by literature research, (2) field survey on tsunami deposit, and (3) designing the analysis code of sediment transport due to tsunami. As to (1), we organize the information gained about tsunami deposits in the database. As to (2), we consolidate methods for surveying and identifying tsunami deposits in the lake based on results of the field survey in Fukui Pref., carried out by JNES. In addition, as to (3), we design the experimental instrument for hydraulic experiment on sediment transport and sedimentation due to tsunamis. These results are reflected in the guideline on the tsunami deposits survey and evaluation. (author)

  16. Electrophoretic Deposition of Gallium with High Deposition Rate

    Directory of Open Access Journals (Sweden)

    Hanfei Zhang

    2014-12-01

    Full Text Available In this work, electrophoretic deposition (EPD is reported to form gallium thin film with high deposition rate and low cost while avoiding the highly toxic chemicals typically used in electroplating. A maximum deposition rate of ~0.6 μm/min, almost one order of magnitude higher than the typical value reported for electroplating, is obtained when employing a set of proper deposition parameters. The thickness of the film is shown to increase with deposition time when sequential deposition is employed. The concentration of Mg(NO32, the charging salt, is also found to be a critical factor to control the deposition rate. Various gallium micropatterns are obtained by masking the substrate during the process, demonstrating process compatibility with microfabrication. The reported novel approach can potentially be employed in a broad range of applications with Ga as a raw material, including microelectronics, photovoltaic cells, and flexible liquid metal microelectrodes.

  17. Os supostos espaços de discussão futebolística na televisão: as "mesas redondas"

    Directory of Open Access Journals (Sweden)

    Thiago Aragão Escher

    2012-03-01

    Full Text Available Este artigo analisa os programas esportivos que supostamente são os espaços de discussão do futebol. Para tanto, escolhemos os programas "Terceiro Tempo", da Rede Bandeirantes de Televisão e "Mesa Redonda", da TV Gazeta, por serem os mais relevantes do gênero e por serem constantemente citados nas respostas dos entrevistados de Reis (2008. Analisamos a estrutura de apresentação dos programas veiculados no ano de 2008, durante a realização do Campeonato Brasileiro de futebol, principalmente sua composição com o merchandising. Conclui-se que a compreensão desse processo não deve ser visto como uma mera mercadorização do esporte, e sim como uma mistura entre o processo simbólico que existe no futebol e sua latente transformação em mercadoria, que contribui também para uma visão fragmentada da violência no futebol e dos torcedores.

  18. El ensayo de interpretación del ser nacional: su problemática y el caso de 'Nosotros' de Luis López de Mesa

    Directory of Open Access Journals (Sweden)

    Juan Camilo Galeano

    2015-01-01

    Full Text Available Este texto se divide en dos partes: la primera aborda el ensayo de interpretación del ser nacional, las voces que lo han desarrollado en América Latina y cuestiona la falta de reconocimiento de este género en Colombia. La segunda considera a Luis López de Mesa: partiendo de su obra De cómo se ha formado la nación colombiana, analiza las estrategias literarias de las que éste se vale en Nosotros para mostrar la identidad antioqueña como resultado de una debacle moral. En el desarrollo del análisis se encuentra que la industrialización de Antioquia hizo mundanos su valores humanos.

  19. Alface à mesa: Implicações sócio-econômicas e ambientais da semente ao prato

    Directory of Open Access Journals (Sweden)

    Reges Echer

    2016-11-01

    Full Text Available Considerando as análises toxicológicas apresentadas pela ANVISA entre 2001 e 2011, e dados sócio-técnicos referentes às diferentes formas de cultivo da hortaliça, o presente trabalho busca elucidar e distinguir os caminhos que a alface trilha da horta à mesa do consumidor. Alicerçando-se numa ótica mais sustentável e seguindo o referencial bibliográfico disponível foi possível inferir sobre os limites e as possibilidades para a produção orgânica de alface, onde os sistemas de produção de base ecológica aparecem como uma alternativa viável e ascendente para a produção da hortaliça no Brasil, integrando conhecimentos populares e científicos com a conservação da biodiversidade local para o fornecimento de alimentos seguros e soberanos da semente ao prato, para o homem e para a natureza.

  20. Revised Geologic Map of the Fort Garland Quadrangle, Costilla County, Colorado

    Science.gov (United States)

    Wallace, Alan R.; Machette, Michael N.

    2008-01-01

    The map area includes Fort Garland, Colo., and the surrounding area, which is primarily rural. Fort Garland was established in 1858 to protect settlers in the San Luis Valley, then part of the Territory of New Mexico. East of the town are the Garland mesas (basalt-covered tablelands), which are uplifted as horsts with the Central Sangre de Cristo fault zone. The map also includes the northern part of the Culebra graben, a deep structural basin that extends from south of San Luis (as the Sanchez graben) to near Blanca, about 8 km west of Fort Garland. The oldest rocks exposed in the map area are early Proterozic basement rocks (granites in Ikes Creek block) that occupy an intermediate structural position between the strongly uplifted Blanca Peak block and the Culebra graben. The basement rocks are overlain by Oligocene volcanic and volcaniclastic rocks of unknown origin. The volcanic rocks were buried by a thick sequence of basin-fill deposits of the Santa Fe Group as the Rio Grande rift formed about 25 million years ago. The Servilleta Basalt, a regional series of 3.7?4.8 Ma old flood basalts, was deposited within sediment, and locally provides a basis for dividing the group into upper and lower parts. Landslide deposits and colluvium that rest on sediments of the Santa Fe Group cover the steep margins of the mesas. Exposures of the sediment beneath the basalt and within the low foothills east of the Central Sangre de Cristo fault zone are comprised of siltstones, sandstones, and minor fluvial conglomerates. Most of the low ground surrounding the mesas and in the graben is covered by surficial deposits of Quaternary age. The alluvial deposits are subdivided into three Pleistocene-age units and three Holocene-age units. The oldest Pleistocene gravel (unit Qao) is preserved as isolated remnants that cap high surfaces north and east of Fort Garland. The primary geologic hazards in the map area are from earthquakes, landslides, and localized flooding. The Central

  1. 20 CFR 703.207 - Kinds of negotiable securities that may be deposited; conditions of deposit; acceptance of deposits.

    Science.gov (United States)

    2010-04-01

    ... amount fixed by the Office under the regulations in this part shall deposit any negotiable securities... deposited; conditions of deposit; acceptance of deposits. 703.207 Section 703.207 Employees' Benefits... AND RELATED STATUTES INSURANCE REGULATIONS Insurance Carrier Security Deposit Requirements § 703.207...

  2. Metabolic Syndrome Derived from Principal Component Analysis and Incident Cardiovascular Events: The Multi Ethnic Study of Atherosclerosis (MESA) and Health, Aging, and Body Composition (Health ABC).

    Science.gov (United States)

    Agarwal, Subhashish; Jacobs, David R; Vaidya, Dhananjay; Sibley, Christopher T; Jorgensen, Neal W; Rotter, Jerome I; Chen, Yii-Der Ida; Liu, Yongmei; Andrews, Jeanette S; Kritchevsky, Stephen; Goodpaster, Bret; Kanaya, Alka; Newman, Anne B; Simonsick, Eleanor M; Herrington, David M

    2012-01-01

    Background. The NCEP metabolic syndrome (MetS) is a combination of dichotomized interrelated risk factors from predominantly Caucasian populations. We propose a continuous MetS score based on principal component analysis (PCA) of the same risk factors in a multiethnic cohort and compare prediction of incident CVD events with NCEP MetS definition. Additionally, we replicated these analyses in the Health, Aging, and Body composition (Health ABC) study cohort. Methods and Results. We performed PCA of the MetS elements (waist circumference, HDL, TG, fasting blood glucose, SBP, and DBP) in 2610 Caucasian Americans, 801 Chinese Americans, 1875 African Americans, and 1494 Hispanic Americans in the multiethnic study of atherosclerosis (MESA) cohort. We selected the first principal component as a continuous MetS score (MetS-PC). Cox proportional hazards models were used to examine the association between MetS-PC and 5.5 years of CVD events (n = 377) adjusting for age, gender, race, smoking and LDL-C, overall and by ethnicity. To facilitate comparison of MetS-PC with the binary NCEP definition, a MetS-PC cut point was chosen to yield the same 37% prevalence of MetS as the NCEP definition (37%) in the MESA cohort. Hazard ratio (HR) for CVD events were estimated using the NCEP and Mets-PC-derived binary definitions. In Cox proportional models, the HR (95% CI) for CVD events for 1-SD (standard deviation) of MetS-PC was 1.71 (1.54-1.90) (P definitions were compared, HR for CVD events was 2.34 (1.91-2.87) for MetS-PC versus 1.79 (1.46-2.20) for NCEP MetS. In the Health ABC cohort, in a fully adjusted model, MetS-PC per 1-SD (Health ABC) remained associated with CVD events (HR = 1.21, 95%CI 1.12-1.32) overall, and for each ethnicity, Caucasian (HR = 1.24, 95%CI 1.12-1.39) and African Americans (HR = 1.16, 95%CI 1.01-1.32). Finally, when using a binary definition of MetS-PC (cut point 0.505) designed to match the NCEP definition in terms of prevalence in the Health ABC cohort (35

  3. Modeling Approach/Strategy for Corrective Action Unit 99: Rainier Mesa and Shoshone Mountain, Nevada Test Site, Nye County, Nevada, Revision 1, with ROTC-1

    Energy Technology Data Exchange (ETDEWEB)

    Greg Ruskauff

    2008-06-01

    This document describes an approach for preliminary (Phase I) flow and transport modeling for the Rainier Mesa/Shoshone Mountain (RMSM) Corrective Action Unit (CAU). This modeling will take place before the planned Phase II round of data collection to better identify the remaining data gaps before the fieldwork begins. Because of the geologic complexity, limited number of borings, and large vertical gradients, there is considerable uncertainty in the conceptual model for flow; thus different conceptual models will be evaluated, in addition to different framework and recharge models. The transport simulations will not be used to formally calculate the Contaminant Boundary at this time. The modeling (Phase II) will occur only after the available data are considered sufficient in scope and quality.

  4. Magmatism and polymetallic mineralization in southwestern Qinzhou-Hangzhou metallogenic belt, South China

    Science.gov (United States)

    Huang, Xudong; Lu, Jianjun; Wang, Rucheng; Ma, Dongsheng

    2016-04-01

    As Neoproterozoic suture zone between the Yangtze Block and Cathaysia Block, Qinzhou-Hangzhou metallogenic belt is one of the 21 key metallogenic belts in China. Intensive multiple-aged felsic magmatism and related polymetallic mineralization take place in this belt. Although Neoproterozoic, Paleozoic, Triassic granites and associated deposits have been found in southwestern Qinzhou-Hangzhou metallogenic belt, Middle-Late Jurassic (150-165 Ma) magmatism and related mineralization is of the most importance. Three major kinds of Middle-Late Jurassic granitoids have been distinguished. (Cu)-Pb-Zn-bearing granitoids are slightly differentiated, calc-alkaline and metaluminous dioritic to granodioritic rocks. Sn-(W)-bearing granites contain dark microgranular enclaves and have high contents of REE and HFSE, suggesting affinities of aluminous A-type (A2) granites. W-bearing granites are highly differentiated and peraluminous rocks. (Cu)-Pb-Zn-bearing granitoids have ɛNd(t) values of -11 ˜ -4 and ɛHf(t) values of -12 ˜ -7, corresponding to TDMC(Nd) from 1.4 to 1.8 Ga and TDMC(Hf) from 1.6 to 2.0 Ga, respectively. The ɛNd(t) values of W-bearing granites vary from -11 to -8 with TDMC(Nd) of 1.6 ˜ 1.9 Ga and ɛHf(t) values change from -16 to -7 with TDMC(Hf) of 1.5 ˜ 2.0 Ga. Compared with (Cu)-Pb-Zn-bearing granitoids and W-bearing granites, the Sn-(W)-bearing granites have higher ɛNd(t) (-8 ˜ -2) and ɛHf(t) (-8 ˜ -2) values and younger TDMC(Nd) (1.1 ˜ 1.6 Ga) and TDMC(Hf) (1.2 ˜ 1.8 Ga) values, showing a more juvenile isotopic character. Sn-(W)-bearing granites originate from partial melting of granulitized lower crust involved with some mantle-derived materials. W-bearing granites are derived from partial melting of crust. (Cu)-Pb-Zn-bearing granitoids are also derived from crust but may be influenced by more mantle-derived materials. For (Cu)-Pb-Zn deposits, skarn and carbonate replacement are the most important mineralization types. Cu ore bodies mainly

  5. Serum phosphate is associated with aortic valve calcification in the Multi-ethnic Study of Atherosclerosis (MESA).

    Science.gov (United States)

    Linefsky, Jason P; O'Brien, Kevin D; Sachs, Michael; Katz, Ronit; Eng, John; Michos, Erin D; Budoff, Matthew J; de Boer, Ian; Kestenbaum, Bryan

    2014-04-01

    This study sought to investigate associations of phosphate metabolism biomarkers with aortic valve calcification (AVC). Calcific aortic valve disease (CAVD) is a common progressive condition that involves inflammatory and calcification mediators. Currently there are no effective medical treatments, but mineral metabolism pathways may be important in the development and progression of disease. We examined associations of phosphate metabolism biomarkers, including serum phosphate, urine phosphate, parathyroid hormone (PTH) and serum fibroblast growth factor (FGF)-23, with CT-assessed AVC at study baseline and in short-term follow-up in 6814 participants of the Multi-Ethnic Study of Atherosclerosis (MESA). At baseline, AVC prevalence was 13.2%. Higher serum phosphate levels were associated with significantly greater AVC prevalence (relative risk 1.3 per 1 mg/dL increment, 95% confidence incidence: 1.1 to 1.5, pAVC. Average follow-up CT evaluation was 2.4 years (range 0.9-4.9 years) with an AVC incidence of 4.1%. Overall, phosphate metabolism biomarkers were not associated with incident AVC except in the top FGF-23 quartile. Serum phosphate levels are significantly associated with AVC prevalence. Further study of phosphate metabolism as a modifiable risk factor for AVC is warranted. Published by Elsevier Ireland Ltd.

  6. Validation of the abbreviated Radon Progeny Integrating Sampling Unit (RPISU) method for Mesa County, Colorado

    International Nuclear Information System (INIS)

    Langner, G.H. Jr.

    1987-06-01

    The US Department of Energy (DOE) Office of Remedial Action and Waste Technology established the Technical Measurements Center at the DOE Grand Junction, Colorado, Projects Office to standardize, calibrate, and compare measurements made in support of DOE remedial action programs. Indoor radon-daughter concentration measurements are made to determine whether a structure is in need of remedial action. The Technical Measurements Center conducted this study to validate an abbreviated Radon Progeny Integrated Sampling Unit (RPISU) method of making indoor radon-daughter measurements to determine whether a structure has a radon-daughter concentration (RDC) below the levels specified in various program standards. The Technical Measurements Center established a criterion against which RDC measurements made using the RPISU sampling method are evaluated to determine if sampling can be terminated or whether further measurements are required. This abbreviated RPISU criterion was tested against 317 actual sets of RPISU data from measurements made over an eight-year period in Mesa County, Colorado. The data from each location were tested against a standard that was assumed to be the same as the actual annual average RDC from that location. At only two locations was the criterion found to fail. Using the abbreviated RPISU method, only 0.6% of locations sampled can be expected to be falsely indicated as having annual average RDC levels below a given standard

  7. Cobalt—Styles of deposits and the search for primary deposits

    Science.gov (United States)

    Hitzman, Murray W.; Bookstrom, Arthur A.; Slack, John F.; Zientek, Michael L.

    2017-11-30

    Cobalt (Co) is a potentially critical mineral. The vast majority of cobalt is a byproduct of copper and (or) nickel production. Cobalt is increasingly used in magnets and rechargeable batteries. More than 50 percent of primary cobalt production is from the Central African Copperbelt. The Central African Copperbelt is the only sedimentary rock-hosted stratiform copper district that contains significant cobalt. Its presence may indicate significant mafic-ultramafic rocks in the local basement. The balance of primary cobalt production is from magmatic nickel-copper and nickel laterite deposits. Cobalt is present in several carbonate-hosted lead-zinc and copper districts. It is also variably present in Besshi-type volcanogenic massive sulfide and siliciclastic sedimentary rock-hosted deposits in back arc and rift environments associated with mafic-ultramafic rocks. Metasedimentary cobalt-copper-gold deposits (such as Blackbird, Idaho), iron oxide-copper-gold deposits, and the five-element vein deposits (such as Cobalt, Ontario) contain different amounts of cobalt. None of these deposit types show direct links to mafic-ultramafic rocks; the deposits may result from crustal-scale hydrothermal systems capable of leaching and transporting cobalt from great depths. Hydrothermal deposits associated with ultramafic rocks, typified by the Bou Azzer district of Morocco, represent another type of primary cobalt deposit.In the United States, exploration for cobalt deposits may focus on magmatic nickel-copper deposits in the Archean and Proterozoic rocks of the Midwest and the east coast (Pennsylvania) and younger mafic rocks in southeastern and southern Alaska; also, possibly basement rocks in southeastern Missouri. Other potential exploration targets include—The Belt-Purcell basin of British Columbia (Canada), Idaho, Montana, and Washington for different styles of sedimentary rock-hosted cobalt deposits;Besshi-type VMS deposits, such as the Greens Creek (Alaska) deposit and

  8. Análise ergonômica dos discentes e da relação cadeira-mesa: avaliação e proposta de ações mitigadoras

    OpenAIRE

    Vanderléia Maria de Faria

    2011-01-01

    A pesquisa teve como objetivo avaliar aspectos ergonômicos na relação discentes e uso cadeira-mesa com o propósito de sugerir medidas mitigadoras para os possíveis problemas de ajuste biomecânico identificados em uma Instituição de Ensino Superior (IES) do Vale do Aço, MG. Trata-se de uma pesquisa quali quantitativa de caráter inferencial e descritivo, cuja amostra constituiu-se de 95 estudantes do Curso de Educação Física na faixa etária de 18 a 30 anos. Para estimativa antropométrica dos se...

  9. Relation of geological structure to seismicity at Pahute Mesa, Nevada Test Site

    International Nuclear Information System (INIS)

    McKeown, F.A.

    1975-01-01

    Some of the abundant and unique geological and seismological data acquired at the Nevada Test Site is integrated with the objectives of (1) resolving some of the ambiguity in explanations of the source of aftershocks of nuclear explosions, and (2) demonstrating the value of using detailed geological and seismological data to infer realistic source parameters of earthquakes. The distribution of epicenters of aftershocks from nuclear explosions at Pahute Mesa suggests that they are related to faults or intersections of faults in the buried ring-fracture zones of calderas rather than to the conspicuous basin-and-range faults exposed at the surface. Histograms of fault length show clearly that faults in a basin-and-range regime differ significantly in length, median length, and distribution of length from faults in a caldera regime. A histogram of fault lengths derived from magnitudes of aftershocks shows both the median and distribution characteristics of caldera faults rather than of basin-and-range faults. Cumulative frequency-fault length-squared plots also show differences in the two fault regimes, and have slopes, herein called bf slopes, of --0.89 for caldera and basin-and-range faults, respectively. The bf slopes are similar to the average slope of a cumulative frequency-strain plot for aftershocks rather than to the b slopes for cumulative frequency-magnitude plots. Although the significance of b and bf slopes and differences between them are not resolved clearly, it is concluded that the fault length and strain data reflect dimensions of seismic sources rather than energy of seismic events. The principal conclusion of the investigation is that the most obvious geology of a seismically active area may not provide the proper basis for inferring seismic-source parameters. (U.S.)

  10. Geophysical exploration for uranium in Champaner group of rocks, Panchmahals district, Gujarat, India: a case study

    International Nuclear Information System (INIS)

    Narasimha Rao, R.L.; Sethuram, S.; Markandeyulu, A.; Chakraborty, K.; Tiku, K.L.

    1997-01-01

    Geophysical investigations comprising gravity, magnetic, resistivity and induced polarization methods were carried out at Garumal, Panchmahals district, Gujarat, where uranium mineralisation occurs in Champaner group of rocks as fracture controlled veins along the axial zone of a WNW-ESE plunging fold. The distinct break in the Bouguer gravity contour map signifies a lineament within the Champaner group of rocks and this probably represents a mega-fracture. Sharp magnetic anomalies forming a ring and the associated high resistivity characterize an acidic intrusive body, the probable source for the uranium mineralisation occurring in this area. Resistivity contour map delineates the lithic boundaries distinctly. The linear magnetic feature observed over a strike length of 2.5 km represents a small scale skarn-type iron ore deposit. (author)

  11. Alcance de la propuesta del modelo pedagógico FPI del SENA en la organización visión y marketing perteneciente a la mesa sectorial de mercadeo

    OpenAIRE

    Reyes Rojas, Germán Enrique; Moreno, Ivan D.

    2016-01-01

    La presente investigación tiene como objetivo indagar sobre la implementación de la propuesta del modelo pedagógico del Sena (formación profesional integral) en las diferentes organizaciones que hacen parte de la mesa sectorial de mercadeo con el fin de visibilizar la necesidad de actualización de su programa de tecnología en gestión de mercados como un aporte a la renovación de sus registros calificados que se presentaran para el año 2017, especialmente en la organización “Visión y Marketing...

  12. The origin of the Avram Iancu U-Ni-Co-Bi-As mineralization, Băiţa (Bihor) metallogenic district, Bihor Mts., Romania

    Science.gov (United States)

    Zajzon, Norbert; Szentpéteri, Krisztián; Szakáll, Sándor; Kristály, Ferenc

    2015-10-01

    The Băiţa metallogenic district in the Bihor Mountains is a historically important mining area in Romania. Uranium mining took place between 1952 and 1998 from various deposits, but very little is known about the geology and mineralogy of these deposits. In this paper, we describe geology and mineralogy of uranium mineralization of the Avram Iancu uranium mine from waste dump samples collected before complete remediation of the site. Texturally and mineralogically complex assemblages of nickeline, cobaltite-gersdorffite solid solution, native Bi, Bi-sulfosalts, molybdenite, and pyrite-chalcopyrite-sphalerite occur with uraninite, "pitchblende," and brannerite in most of the ore samples. The association of nickel, cobalt, and arsenic with uranium is reminiscent of five-element association of vein type U-Ni-Co-Bi-As deposits; however, the Avram Iancu ores appear to be more replacement-type stratiform/stratabound. Avram Iancu ore samples contain multistage complex, skarn, uranium sulfide, arsenide assemblages that can be interpreted to have been formed in the retrograde cooling stages of the skarn hydrothermal system. This mineralizing system may have built-up along Upper Cretaceous-Paleogene "Banatite" intrusions of diorite-to-granite composition. The intrusions crosscut the underlying uraniferous Permian formations in the stacked NW-verging Biharia Nappe System. The mineralization forms stacked, multilayer replacement horizons, along carbonate-rich lithologies within the metavolcanic (tuffaceous) Muncel Series. Mineral paragenesis and some mineral chemistry suggest moderate-to-high <450, i.e., 350-310 °C, formation temperatures for the uranium sulfide stage along stratigraphically controlled replacement zones and minor veins. Uranium minerals formed abundantly in this early stage and include botryoidal, sooty and euhedral uraninite, brannerite, and coffinite. Later and/or lower-temperature mineral assemblages include heterogeneous, complexly zoned arsenide

  13. Conjunto de juegos de mesa como una opción recreativa para el Círculo de Abuelos del Reparto Nuevo del Consejo Popular Jagüey Cuyují

    Directory of Open Access Journals (Sweden)

    Candelario Lugo Padrón

    2008-09-01

    Full Text Available La poca asistencia del adulto mayor a las actividades deportivas recreativas que se realizan en las comunidades es algo muy generalizado en el municipio de Pinar del Río. Por medio del juego el hombre tiene la posibilidad de: expresar espontáneamente sus emociones, romper con la rutina, reducir estrés, integrarse socialmente, descubrir sus aptitudes, ejercitar sus habilidades, desarrollar su capacidad creadora, contrarrestar hábitos antisociales y nocivos para su salud física y mental, es por esa razón que le vemos gran importancia a esta investigación. Para darle solución a esta situación, se realizó un estudio exploratorio de los motivos por los cuales el adulto mayor no participa en las actividades deportiva recreativas, en el consultorio # 121 del consejo popular Jagüey Cuyují se obtuvo como resultado fundamentalmente, el no sentirse estimulados por la misma, planteando que no existían actividades que se correspondieran con sus gustos y preferencias. Los juegos de mesa como opciones recreativas propuestos brindan una adecuada arma para los profesores de Cultura Física, que utilizándola permitirán el incremento de la participación del adulto mayor en las actividades de la comunidad. El contenido de los juegos de mesa propuestos, fueron sometidos al criterio de los especialistas, constatándose que estos van a permitir que el adulto mayor del consejo popular Jagüey Cuyují sientan la necesidad de participar en las actividades deportivas recreativas ya que los mismos están acordes a su edad y de esta forma eleven su calidad de vida.

  14. Completion Report for Well ER-20-12: Corrective Action Units 101 and 102: Central and Western Pahute Mesa

    Energy Technology Data Exchange (ETDEWEB)

    Wurtz, Jeff [Navarro-Intera, LLC (N-I), Las Vegas, NV (United States)

    2016-08-01

    Well ER-20-12 was drilled for the U.S. Department of Energy, Nevada National Security Administration Nevada Field Office in support of the Underground Test Area Activity. The well was drilled from October 2015 to January 2016 as an addition to the Central and Western Pahute Mesa corrective action units 101 and 102 the Phase II drilling program. Well ER-20-12 was identified based on recommendations of the Pahute Mesa Guidance Team as a result of anomalous tritium detections in groundwater samples collected from Well PM-3 in 2011 and 2013. The primary purpose of the well was to provide information on the hydrogeology in the area downgradient of select underground tests on Western Pahute Mesa and define hydraulic properties in the saturated Tertiary volcanic rocks. The main 46.99-centimeter (cm) (18.5-inch [in.]) borehole was drilled to a depth of 765.14 meters (m) (2,510.3 ft) and the hole opened to 66.04 cm (26 in.); followed by the 50.80-cm (20-in.) surface casing, which was installed and sealed with cement; and a piezometer (p4) was set in the Timber Mountain welded-tuff aquifer (TMWTA) between the casing and the open borehole. The borehole was continued with a 46.99-cm (18.5-in.) drill bit to a depth of 1,326.53 m (4,352.16 ft), and an intermediate 24.44-cm (9.625-in.) casing was installed and sealed to 1,188.72 m (3,900.00 ft) A piezometer (p3) was installed across the Calico Hills zeolitic composite unit (CHZCM) (lava-flow aquifer [LFA]) in the annulus of the open borehole. Two additional piezometers were installed and completed between the intermediate casing and the borehole wall, one (p2) in the CHZCM and one (p1) in the Belted Range aquifer (BRA). The piezometers are set to monitor groundwater properties in the completed intervals. The borehole was continued with a 21.59-cm (8.5-in.) drill bit to a total depth of 1,384.80 m (4,543.33 ft), and the main completion 13.97-cm (5.5-in.) casing was installed in the open borehole across the Pre-Belted Range

  15. Completion Report for Well ER-20-12: Corrective Action Units 101 and 102: Central and Western Pahute Mesa

    International Nuclear Information System (INIS)

    Wurtz, Jeff

    2016-01-01

    Well ER-20-12 was drilled for the U.S. Department of Energy, Nevada National Security Administration Nevada Field Office in support of the Underground Test Area Activity. The well was drilled from October 2015 to January 2016 as an addition to the Central and Western Pahute Mesa corrective action units 101 and 102 the Phase II drilling program. Well ER-20-12 was identified based on recommendations of the Pahute Mesa Guidance Team as a result of anomalous tritium detections in groundwater samples collected from Well PM-3 in 2011 and 2013. The primary purpose of the well was to provide information on the hydrogeology in the area downgradient of select underground tests on Western Pahute Mesa and define hydraulic properties in the saturated Tertiary volcanic rocks. The main 46.99-centimeter (cm) (18.5-inch) borehole was drilled to a depth of 765.14 meters (m) (2,510.3 ft) and the hole opened to 66.04 cm (26 in.); followed by the 50.80-cm (20-in.) surface casing, which was installed and sealed with cement; and a piezometer (p4) was set in the Timber Mountain welded-tuff aquifer (TMWTA) between the casing and the open borehole. The borehole was continued with a 46.99-cm (18.5-in.) drill bit to a depth of 1,326.53 m (4,352.16 ft), and an intermediate 24.44-cm (9.625-in.) casing was installed and sealed to 1,188.72 m (3,900.00 ft) A piezometer (p3) was installed across the Calico Hills zeolitic composite unit (CHZCM) (lava-flow aquifer [LFA]) in the annulus of the open borehole. Two additional piezometers were installed and completed between the intermediate casing and the borehole wall, one (p2) in the CHZCM and one (p1) in the Belted Range aquifer (BRA). The piezometers are set to monitor groundwater properties in the completed intervals. The borehole was continued with a 21.59-cm (8.5-in.) drill bit to a total depth of 1,384.80 m (4,543.33 ft), and the main completion 13.97-cm (5.5-in.) casing was installed in the open borehole across the Pre-Belted Range composite

  16. Investigation of the distal margins of the LVF/LDA environments in the northern midlatitudes of Mars.

    Science.gov (United States)

    Morgan, G. A.; Head, J. W., III

    2008-09-01

    Introduction The northern dichotomy boundary on Mars consists of an abrupt escarpment between the cratered uplands and the northern plains. The boundary is characterized by fretted valleys which divide the uplands into a series of plateaus and mesas which become progressively smaller to the north and eventually merge with the northern plains [1]. Lineated Valley Fill (LVF) and Lobate Debris Aprons (LDA) deposits are a prominent feature of the dichotomy boundary [2] and have been attributed by some [e.g., 3] to be the remains of debris-covered glaciers that were active during previous climatic regimes when snow was deposited along the dichotomy boundary [4-5]. Recent in depth analysis of LVF/LDA has been made possible by new comprehensive high-resolution data from Mars Odyssey, Mars Express and Mars Reconnaissance Orbiter. and has revealed evidence for multiple LVF/LDA emplacement events [6-8], as well as evidence for plateau glaciation [4] and evidence that glacial conditions extended much further from the margins of the dichotomy boundary than previously thought [4]. However, remaining unexamined, however, are the regions adjacent to the current positions of the LVF/LDA deposits where one can explore the relationship between the distal landforms present there and the main bodies of LVF/LDA. We have therefore investigated an area of the northern plains directly north of a region of the dichotomy boundary where detailed studies have reported largescale integrated LVF systems >10,000 km3 in extent, that are analogous to terrestrial debris covered glacial systems [3,6-8]. Through the utilization of the most recent data sets (CTX and HiRISE) we have categorized the distinct landform assemblages associated with this area and documented the degraded nature of lobate debris aprons and related features present there. Degraded Lobate Debris Aprons All of the LDAs in the study region have troughs cut into their surface which are aligned in the same direction as the flanks of

  17. Acid Deposition Phenomena

    International Nuclear Information System (INIS)

    Ramadan, A.E.K.

    2004-01-01

    Acid deposition, commonly known as acid rain, occurs when emissions from the combustion of fossil fuels and other industrial processes undergo complex chemical reactions in the atmosphere and fall to the earth as wet deposition (rain, snow, cloud, fog) or dry deposition (dry particles, gas). Rain and snow are already naturally acidic, but are only considered problematic when less than a ph of 5.0 The main chemical precursors leading to acidic conditions are atmospheric concentrations of sulfur dioxide (SO 2 ) and nitrogen oxides (NO x ). When these two compounds react with water, oxygen, and sunlight in the atmosphere, the result is sulfuric (H 2 SO 4 ) and nitric acids (HNO 3 ), the primary agents of acid deposition which mainly produced from the combustion of fossil fuel and from petroleum refinery. Airborne chemicals can travel long distances from their sources and can therefore affect ecosystems over broad regional scales and in locations far from the sources of emissions. According to the concern of petroleum ministry with the environment and occupational health, in this paper we will discussed the acid deposition phenomena through the following: Types of acidic deposition and its components in the atmosphere Natural and man-made sources of compounds causing the acidic deposition. Chemical reactions causing the acidic deposition phenomenon in the atmosphere. Factors affecting level of acidic deposition in the atmosphere. Impact of acid deposition. Procedures for acidic deposition control in petroleum industry

  18. Psychosocial Predictors of Metabolic Syndrome among Latino Groups in the Multi-Ethnic Study of Atherosclerosis (MESA.

    Directory of Open Access Journals (Sweden)

    Manuel S Ortiz

    Full Text Available We sought to determine the contribution of psychological variables to risk for metabolic syndrome (MetS among Latinos enrolled in the Multi-Ethnic Study of Atherosclerosis (MESA, and to investigate whether social support moderates these associations, and whether inflammatory markers mediate the association between psychological variables and MetS.Cross-sectional analyses at study baseline were conducted with a national Latino cohort (n = 1,388 that included Mexican Americans, Dominican Americans, Puerto Rican Americans and Central/South Americans. Hierarchical logistic regression analyses were conducted to test the effects of psychosocial variables (chronic stress, depressive symptoms, and social support on MetS. In addition, separate subgroup-specific models, controlling for nationality, age, gender, socioeconomic position, language spoken at home, exercise, smoking and drinking status, and testing for the effects of chronic stress, depressive symptoms and inflammation (IL-6, CRP, fibrinogen in predicting risk for MetS were conducted.In the overall sample, high chronic stress independently predicted risk for MetS, however this association was found to be significant only in Mexican Americans and Puerto Rican Americans. Social support did not moderate the associations between chronic stress and MetS for any group. Chronic stress was not associated with inflammatory markers in either the overall sample or in each group.Our results suggest a differential contribution of chronic stress to the prevalence of MetS by national groups.

  19. Local deposition of high-purity Pt nanostructures by combining electron beam induced deposition and atomic layer deposition

    NARCIS (Netherlands)

    Mackus, A.J.M.; Mulders, J.J.L.; Sanden, van de M.C.M.; Kessels, W.M.M.

    2010-01-01

    An approach for direct-write fabrication of high-purity platinum nanostructures has been developed by combining nanoscale lateral patterning by electron beam induced deposition (EBID) with area-selective deposition of high quality material by atomic layer deposition (ALD). Because virtually pure,

  20. Assimilation of carbonate country rock by the parent magma of the Panzhihua Fe-Ti-V deposit (SW China: Evidence from stable isotopes

    Directory of Open Access Journals (Sweden)

    Clément Ganino

    2013-09-01

    Full Text Available The Panzhihua intrusion in southwest China is part of the Emeishan Large Igneous Province and host of a large Fe-Ti-V ore deposit. During emplacement of the main intrusion, multiple generations of mafic dykes invaded carbonate wall rocks, producing a large contact aureole. We measured the oxygen-isotope composition of the intrusions, their constituent minerals, and samples of the country rock. Magnetite and plagioclase from Panzhihua intrusion have δ18O values that are consistent with magmatic equilibrium, and formed from magmas with δ18O values that were 1–2‰ higher than expected in a mantle-derived magma. The unmetamorphosed country rock has high δ18O values, ranging from 13.2‰ (sandstone to 24.6–28.6‰ (dolomite. The skarns and marbles from the aureole have lower δ18O and δ13C values than their protolith suggesting interaction with fluids that were in exchange equilibrium with the adjacent mafic magmas and especially the numerous mafic dykes that intruded the aureole. This would explain the alteration of δ18O of the dykes which have significantly higher values than expected for a mantle-derived magma. Depending on the exact δ18O values assumed for the magma and contaminant, the amount of assimilation required to produce the elevated δ18O value of the Panzhihua intrusion was between 8 and 13.7 wt.%, assuming simple mixing. The exact mechanism of contamination is unclear but may involve a combination of assimilation of bulk country rock, mixing with a melt of the country rock and exchange with CO2-rich fluid derived from decarbonation of the marls and dolomites. These mechanisms, particularly the latter, were probably involved in the formation of the Fe-Ti-V ores.

  1. Formation of hydrothermal tin deposits: Raman spectroscopic evidence for an important role of aqueous Sn(IV) species

    Science.gov (United States)

    Schmidt, Christian

    2018-01-01

    The speciation of tin and the solubility of cassiterite in H2O + HCl were determined at temperatures to 600 °C using in situ Raman spectroscopy. In addition, information on the fluid-melt partition of Sn was obtained at 700 °C and indicated a preference of the fluid only at HCl concentrations that are much higher than in fluids exsolved from natural felsic melts. Dissolution of cassiterite generally resulted in formation of Sn(IV) species unless reduced conditions were generated by hydrogen permeation or carbohydrates in the starting material. The prevalent aqueous Sn(IV) species was [SnCl4(H2O)2]0, with additional [SnCl3(H2O)3]+ and [SnCl5(H2O)]-. The only detectable Sn(II) species was very likely [Sn(II)Cl3]-. Cassiterite solubility increased with HCl concentration and was generally high in H2O+HCl fluids, with no strong dependencies on temperature, pressure, or the oxidation state of tin in the fluid. The Sn(IV) concentrations at 500 and 600 °C determined from the integrated ν1[Sn(IV)sbnd Cl] band intensity are in good agreement with literature data on the cassiterite solubility in H2O + HCl at oxygen fugacities along the hematite-magnetite buffer. The combined results from previous experimental studies and this study demonstrate that HCl molality is a crucial parameter for hydrothermal mobilization and transport of tin and for cassiterite precipitation, and that pH, pressure and temperature are less important. Current models on hydrothermal tin deposit formation need to be augmented to include Sn(IV)sbnd Cl complexes as significant tin-transporting species. Irrespective of the oxidation state of tin in the fluid, cassiterite precipitates due to reaction of the hydrothermal fluid with the wall rock (greisen or skarn formation), dilution (mixing with meteoric water) or a decrease in the HCl activity in the aqueous liquid by boiling. A redox reaction is only required for tin transported as Sn(II) to be converted to Sn(IV).

  2. Associations between C-reactive protein, coronary artery calcium, and cardiovascular events: implications for the JUPITER population from MESA, a population-based cohort study.

    Science.gov (United States)

    Blaha, Michael J; Budoff, Matthew J; DeFilippis, Andrew P; Blankstein, Ron; Rivera, Juan J; Agatston, Arthur; O'Leary, Daniel H; Lima, Joao; Blumenthal, Roger S; Nasir, Khurram

    2011-08-20

    The JUPITER trial showed that some patients with LDL-cholesterol concentrations less than 3·37 mmol/L (JUPITER, we established whether coronary artery calcium (CAC) might further stratify risk; additionally we compared hsCRP with CAC for risk prediction across the range of low and high hsCRP values. 950 participants from the Multi-Ethnic Study of Atheroslcerosis (MESA) met all criteria for JUPITER entry. We compared coronary heart disease and cardiovascular disease event rates and multivariable-adjusted hazard ratios after stratifying by burden of CAC (scores of 0, 1-100, or >100). We calculated 5-year number needed to treat (NNT) by applying the benefit recorded in JUPITER to the event rates within each CAC strata. Median follow-up was 5·8 years (IQR 5·7-5·9). 444 (47%) patients in the MESA JUPITER population had CAC scores of 0 and, in this group, rates of coronary heart disease events were 0·8 per 1000 person-years. 74% of all coronary events were in the 239 (25%) of participants with CAC scores of more than 100 (20·2 per 1000 person-years). For coronary heart disease, the predicted 5-year NNT was 549 for CAC score 0, 94 for scores 1-100, and 24 for scores greater than 100. For cardiovascular disease, the NNT was 124, 54, and 19. In the total study population, presence of CAC was associated with a hazard ratio of 4·29 (95% CI 1·99-9·25) for coronary heart disease, and of 2·57 (1·48-4·48) for cardiovascular disease. hsCRP was not associated with either disease after multivariable adjustment. CAC seems to further stratify risk in patients eligible for JUPITER, and could be used to target subgroups of patients who are expected to derive the most, and the least, absolute benefit from statin treatment. Focusing of treatment on the subset of individuals with measurable atherosclerosis could allow for more appropriate allocation of resources. National Institutes of Health-National Heart, Lung, and Blood Institute. Copyright © 2011 Elsevier Ltd. All rights

  3. DepositScan, a Scanning Program to Measure Spray Deposition Distributions

    Science.gov (United States)

    DepositScan, a scanning program was developed to quickly measure spray deposit distributions on water sensitive papers or Kromekote cards which are widely used for determinations of pesticide spray deposition quality on target areas. The program is installed in a portable computer and works with a ...

  4. 78 FR 56583 - Deposit Insurance Regulations; Definition of Insured Deposit

    Science.gov (United States)

    2013-09-13

    ... as a potential global deposit insurer, preserve confidence in the FDIC deposit insurance system, and... the United States.\\2\\ The FDIC generally pays out deposit insurance on the next business day after a... since 2001 and total approximately $1 trillion today. In many cases, these branches do not engage in...

  5. Pulmonary hyperinflation due to gas trapping and pulmonary artery size: The MESA COPD Study.

    Directory of Open Access Journals (Sweden)

    Hooman D Poor

    Full Text Available Pulmonary hypertension is associated with increased morbidity and mortality in chronic obstructive pulmonary disease (COPD. Since pulmonary artery (PA size increases in pulmonary hypertension, we measured PA cross-sectional area using magnetic resonance imaging (MRI to test the hypothesis that pulmonary hyperinflation due to gas trapping is associated with PA cross-sectional area in COPD.The MESA COPD Study recruited participants with COPD and controls from two population-based cohort studies ages 50-79 years with 10 or more pack-years and free of clinical cardiovascular disease. Body plethysmography was performed according to standard criteria. Cardiac MRI was performed at functional residual capacity to measure the cross-sectional area of the main PA. Percent emphysema was defined as the percentage of lung voxels less than -950 Hounsfield units as assessed via x-ray computed tomography. Analyses were adjusted for age, gender, height, weight, race-ethnicity, the forced expiratory volume in one second, smoking status, pack-years, lung function, oxygen saturation, blood pressure, left ventricular ejection fraction and percent emphysema.Among 106 participants, mean residual volume was 1.98±0.71 L and the mean PA cross-sectional area was 7.23±1.72 cm2. A one standard deviation increase in residual volume was independently associated with an increase in main PA cross-sectional area of 0.55 cm2 (95% CI 0.18 to 0.92; p = 0.003. In contrast, there was no evidence for an association with percent emphysema or total lung capacity.Increased residual volume was associated with a larger PA in COPD, suggesting that gas trapping may contribute to pulmonary hypertension in COPD.

  6. Deposition characteristics of titanium coating deposited on SiC fiber by cold-wall chemical vapor deposition

    Energy Technology Data Exchange (ETDEWEB)

    Luo, Xian, E-mail: luo_shenfan@hotmail.com; Wu, Shuai; Yang, Yan-qing; Jin, Na; Liu, Shuai; Huang, Bin

    2016-12-01

    The deposition characteristics of titanium coating on SiC fiber using TiCl{sub 4}-H{sub 2}-Ar gas mixture in a cold-wall chemical vapor deposition were studied by the combination of thermodynamic analysis and experimental studies. The thermodynamic analysis of the reactions in the TiCl{sub 4}-H{sub 2}-Ar system indicates that TiCl{sub 4} transforms to titanium as the following paths: TiCl{sub 4} → TiCl{sub 3} → Ti, or TiCl{sub 4} → TiCl{sub 3} → TiCl{sub 2} → Ti. The experimental results show that typical deposited coating contains two distinct layers: a TiC reaction layer close to SiC fiber and titanium coating which has an atomic percentage of titanium more than 70% and that of carbon lower than 30%. The results illustrate that a carbon diffusion barrier coating needs to be deposited if pure titanium is to be prepared. The deposition rate increases with the increase of temperature, but higher temperature has a negative effect on the surface uniformity of titanium coating. In addition, appropriate argon gas flow rate has a positive effect on smoothing the surface morphology of the coating. - Highlights: • Both thermodynamic analysis and experimental studies were adopted in this work. • The transformation paths of TiCl{sub 4} to Ti is: TiCl{sub 4} → TiCl{sub 3} → Ti, or TiCl{sub 4} → TiCl{sub 3} → TiCl{sub 2} → Ti. • Typical deposited Ti coating on SiC fiber contained two distinct layers. • Deposition temperature is important on deposition rate and morphologies. • Appropriate argon gas flow rate has a positive effect on smoothing of the coating.

  7. Deposition of Boron in Possible Evaporite Deposits in Gale Crate

    Science.gov (United States)

    Gasda, P. J.; Peets, E.; Lamm, S. N.; Rapin, W.; Lanza, N.; Frydenvang, J.; Clark, B. C.; Herkenhoff, K. E.; Bridges, J.; Schwenzer, S. P.; Haldeman, E. B.; Wiens, R. C.; Maurice, S.; Clegg, S. M.; Delapp, D.; Sanford, V.; Bodine, M. R.; McInroy, R.

    2017-12-01

    Boron has been previously detected in Gale crater using the ChemCam instrument on board the NASA Curiosity rover within calcium sulfate fracture fill hosted by lacustrine mudstone and eolian sandstone units. Recent results show that up to 300 ppm B is present in the upper sections of the lacustrine unit. Boron has been detected in both the groundwater-emplaced calcium sulfate fracture fill materials and bedding-parallel calcium sulfate layers. The widespread bedding-parallel calcium sulfate layers within the upper strata of the lacustrine bedrock that Curiosity has encountered recently could be interpreted as primary evaporite deposits. We have two hypotheses for the history of boron in Gale crater. In both hypotheses, borates were first deposited as lake water evaporated, depositing primary evaporates that were later re-dissolved by groundwater, which redistributed the boron into secondary evaporitic calcium sulfate fracture fill deposits. In the first scenario, Gale crater may have undergone a period of perennial lake formation during a drier period of martian history, depositing layers of evaporitic minerals (including borates) among lacustrine mudstone layers. In the second scenario, lake margins could have become periodically exposed during cyclic drops in lake level and subsequently desiccated. Evaporites were deposited and desiccation features were formed in lowstand deposits. Either hypothetical scenario of evaporite deposition would promote prebiotic chemical reactions via wet-dry cycles. Boron may be an important prebiotic element, and as such, its presence in ancient martian surface and groundwater provides evidence that important prebiotic chemical reactions could occur on Mars if organics were present. The presence of boron in ancient Gale crater groundwater also provides additional evidence that a habitable environment existed in the martian subsurface well after the expected disappearance of liquid water on the surface of Mars. We will report on the

  8. Investigation on the age of mineralization in the Sungun porphyry Cu-Mo deposit, NW Iran with a regional metallogenic perspective

    Science.gov (United States)

    Simmonds, Vartan; Moazzen, Mohssen; Mathur, Ryan

    2016-04-01

    The Sungun porphyry copper deposit (PCD) is located in NW Iran, neighbouring several other PCDs and prospects in the region and the Lesser Caucasus (south Armenia). It lies on the Urumieh-Dokhtar magmatic arc (UDMA), which formed through the northeast-ward subduction of the Neo-Tethyan oceanic crust beneath the Central Iranian plate during late-Mesozoic and early-Cenozoic [1], and hosts the porphyry copper metallogenic belt of Iran. The Sungun PCD is the second largest deposit in Iran with ore reserves of about 850 Mt at 0.62 wt% Cu and 0.01 wt% Mo and probable reserves over 1Gt. The monzonitic to quartz monzonitic porphyry stock intruded the upper Cretaceous carbonates and Eocene volcano-sedimentary rocks. It produced a skarn-type mineralization at its contact zone with the carbonate rocks, as well as vast hydrothermal alteration zones and porphyry-type Cu and Mo mineralization. The zircon U-Pb age of the host porphyry stock is about 22.5±0.4 to 20.1±0.4 Ma [2]. Re-Os dating of four molybdenite separates from this PCD shows ages ranging between 22.9±0.2 to 21.7±0.2 Ma, with an average of 22.57±0.2 Ma, corresponding to the early Miocene (Aquitanian). These ages indicate that both the porphyry stock and the Cu-Mo mineralization are post-collisional events, similar to many other deposits and prospects in NW and central Iran and south Armenia, and the mineralization occurred shortly after the emplacement of the host stock, corresponding better to the ages obtained from the marginal parts of the stock. Magmatism and mineralization in Sungun coincides with the third metallogenic epoch in the Lesser Caucasus (Eocene to Miocene; [3]), though it is considerably younger than all of the dated PCDs and prospects in the south Armenia. It also postdates Cu-Mo mineralizations in the Saheb Divan (35 Ma), Qaradagh batholith (31.22±0.28 to 25.19±0.19 Ma), as well as Haft Cheshmeh PCD (28.18±0.42 to 27.05±0.37 Ma) in NW Iran, while it seems to be coeval with the Kighal

  9. Relationship of aortic valve calcification with coronary artery calcium severity: the Multi-Ethnic Study of Atherosclerosis (MESA).

    Science.gov (United States)

    Nasir, Khurram; Katz, Ronit; Al-Mallah, Mouaz; Takasu, Junichiro; Shavelle, David M; Carr, Jeffery J; Kronmal, Richard; Blumenthal, Roger S; O'Brien, Kevin; Budoff, Matthew J

    2010-01-01

    Aortic valve calcification (AVC) and atherosclerosis share causative and pathologic features. We evaluated the relationship between AVC and coronary artery calcium (CAC) severity in the Multi-Ethnic Study of Atherosclerosis (MESA). Men and women aged 45-84 years (n=6809; mean age, 62 years) were studied. The presence and burden of AVC and CAC were determined by noncontrast cardiac computed tomography. Relative risk regression was used to model the probability of AVC as a function of CAC > 0 as well as CAC categories (0, 1-99, 100-399, and > or = 400) with the reference group being CAC=0. The prevalence of AVC and CAC was 13% and 50%, respectively. Among those without CAC, the prevalence of AVC was 5% and increased across levels of CAC severity such that 14%, 25%, and 38% had AVC with increasing CAC scores of 1-99, 100-399, and > or = 400, respectively (P for trendAVC among those with mild CAC (1-99) was 1.83 (95% CI, 1.45-2.31) and increased to 3.36 (95% CI, 2.56-4.42) for CAC > or = 400. Similar statistically significant increased risk of AVC was found when CAC was assessed as a continuous variable. Our study shows that AVC is independently associated with increasing severity of CAC. 2010 Society of Cardiovascular Computed Tomography. Published by Elsevier Inc. All rights reserved.

  10. Radiological survey and evaluation of the fallout area from the Trinity test: Chupadera Mesa and White Sands Missile Range, New Mexico

    International Nuclear Information System (INIS)

    Hansen, W.R.; Rodgers, J.C.

    1985-06-01

    Current radiological conditions were evaluated for the site of the first nuclear weapons test, the Trinity test, and the associated fallout zone. The test, located on White Sands Missile Range, was conducted as part of the research with nuclear materials for the World War II Manhattan Engineer District atomic bomb project. Some residual radioactivity attributable to the test was found in the soils of Ground Zero on White Sands Missile Range and the areas that received fallout from the test. The study considered relevant information including historical records, environmental data extending back to the 1940s, and new data acquired by field sampling and measurements. Potential exposures to radiation were evaluated for current land uses. Maximum estimated doses on Chupadera Mesa and other uncontrolled areas are less than 3% of the DOE Radiation Protection Standards (RPSs). Radiation exposures during visits to the US Army-controlled Ground Zero area are less than 1 mrem per annual visit or less than 0.2% of the RPS for a member of the public. Detailed data and interpretations are provided in appendixes. 14 figs., 45 tabs

  11. Radiological survey and evaluation of the fallout area from the Trinity test: Chupadera Mesa and White Sands Missile Range, New Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Hansen, W.R.; Rodgers, J.C.

    1985-06-01

    Current radiological conditions were evaluated for the site of the first nuclear weapons test, the Trinity test, and the associated fallout zone. The test, located on White Sands Missile Range, was conducted as part of the research with nuclear materials for the World War II Manhattan Engineer District atomic bomb project. Some residual radioactivity attributable to the test was found in the soils of Ground Zero on White Sands Missile Range and the areas that received fallout from the test. The study considered relevant information including historical records, environmental data extending back to the 1940s, and new data acquired by field sampling and measurements. Potential exposures to radiation were evaluated for current land uses. Maximum estimated doses on Chupadera Mesa and other uncontrolled areas are less than 3% of the DOE Radiation Protection Standards (RPSs). Radiation exposures during visits to the US Army-controlled Ground Zero area are less than 1 mrem per annual visit or less than 0.2% of the RPS for a member of the public. Detailed data and interpretations are provided in appendixes. 14 figs., 45 tabs.

  12. Economical Atomic Layer Deposition

    Science.gov (United States)

    Wyman, Richard; Davis, Robert; Linford, Matthew

    2010-10-01

    Atomic Layer Deposition is a self limiting deposition process that can produce films at a user specified height. At BYU we have designed a low cost and automated atomic layer deposition system. We have used the system to deposit silicon dioxide at room temperature using silicon tetrachloride and tetramethyl orthosilicate. Basics of atomic layer deposition, the system set up, automation techniques and our system's characterization are discussed.

  13. Metabolic Syndrome Derived from Principal Component Analysis and Incident Cardiovascular Events: The Multi Ethnic Study of Atherosclerosis (MESA and Health, Aging, and Body Composition (Health ABC

    Directory of Open Access Journals (Sweden)

    Subhashish Agarwal

    2012-01-01

    Full Text Available Background. The NCEP metabolic syndrome (MetS is a combination of dichotomized interrelated risk factors from predominantly Caucasian populations. We propose a continuous MetS score based on principal component analysis (PCA of the same risk factors in a multiethnic cohort and compare prediction of incident CVD events with NCEP MetS definition. Additionally, we replicated these analyses in the Health, Aging, and Body composition (Health ABC study cohort. Methods and Results. We performed PCA of the MetS elements (waist circumference, HDL, TG, fasting blood glucose, SBP, and DBP in 2610 Caucasian Americans, 801 Chinese Americans, 1875 African Americans, and 1494 Hispanic Americans in the multiethnic study of atherosclerosis (MESA cohort. We selected the first principal component as a continuous MetS score (MetS-PC. Cox proportional hazards models were used to examine the association between MetS-PC and 5.5 years of CVD events (n=377 adjusting for age, gender, race, smoking and LDL-C, overall and by ethnicity. To facilitate comparison of MetS-PC with the binary NCEP definition, a MetS-PC cut point was chosen to yield the same 37% prevalence of MetS as the NCEP definition (37% in the MESA cohort. Hazard ratio (HR for CVD events were estimated using the NCEP and Mets-PC-derived binary definitions. In Cox proportional models, the HR (95% CI for CVD events for 1-SD (standard deviation of MetS-PC was 1.71 (1.54–1.90 (P<0.0001 overall after adjusting for potential confounders, and for each ethnicity, HRs were: Caucasian, 1.64 (1.39–1.94, Chinese, 1.39 (1.06–1.83, African, 1.67 (1.37–2.02, and Hispanic, 2.10 (1.66-2.65. Finally, when binary definitions were compared, HR for CVD events was 2.34 (1.91–2.87 for MetS-PC versus 1.79 (1.46–2.20 for NCEP MetS. In the Health ABC cohort, in a fully adjusted model, MetS-PC per 1-SD (Health ABC remained associated with CVD events (HR=1.21, 95%CI 1.12–1.32 overall, and for each ethnicity, Caucasian (HR

  14. Achieving uniform layer deposition by atmospheric-pressure plasma-enhanced chemical vapor deposition

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jae-Ok [Department of Plasma Engineering, Korea Institute of Machinery & Materials (KIMM), Daejeon 305-343 (Korea, Republic of); Kang, Woo Seok, E-mail: kang@kimm.re.kr [Department of Plasma Engineering, Korea Institute of Machinery & Materials (KIMM), Daejeon 305-343 (Korea, Republic of); Department of Environment & Energy Mechanical Engineering, University of Science & Technology (UST), Daejeon 305-350 (Korea, Republic of); Hur, Min; Lee, Jin Young [Department of Plasma Engineering, Korea Institute of Machinery & Materials (KIMM), Daejeon 305-343 (Korea, Republic of); Song, Young-Hoon [Department of Plasma Engineering, Korea Institute of Machinery & Materials (KIMM), Daejeon 305-343 (Korea, Republic of); Department of Environment & Energy Mechanical Engineering, University of Science & Technology (UST), Daejeon 305-350 (Korea, Republic of)

    2015-12-31

    This work investigates the use of plasma-enhanced chemical vapor deposition under atmospheric pressure for achieving uniform layer formation. Electrical and optical measurements demonstrated that the counterbalance between oxygen and precursors maintained the homogeneous discharge mode, while creating intermediate species for layer deposition. Several steps of the deposition process of the layers, which were processed on a stationary stage, were affected by flow stream and precursor depletion. This study showed that by changing the flow streamlines using substrate stage motion uniform layer deposition under atmospheric pressure can be achieved. - Highlights: • Zirconium oxide was deposited by atmospheric-pressure plasma-enhanced chemical vapor deposition. • Homogeneous plasma was maintained by counterbalancing between discharge gas and precursors. • Several deposition steps were observed affected by the gas flow stream and precursor depletion. • Thin film layer was uniformly grown when the substrate underwent a sweeping motion.

  15. Pulsed laser deposition in Twente: from research tool towards industrial deposition

    NARCIS (Netherlands)

    Blank, David H.A.; Dekkers, Jan M.; Rijnders, Augustinus J.H.M.

    2014-01-01

    After the discovery of the perovskite high Tc superconductors in 1986, a rare and almost unknown deposition technique attracted attention. Pulsed laser deposition (PLD), or laser ablation as it was called in the beginning, became popular because of the possibility to deposit complex materials, like

  16. Estimation of Unsaturated Zone Traveltimes for Rainier Mesa and Shoshone Mountain, Nevada Test Site, Nevada, Using a Source-Responsive Preferential-Flow Model

    Science.gov (United States)

    Ebel, Brian A.; Nimmo, John R.

    2009-01-01

    Traveltimes for contaminant transport by water from a point in the unsaturated zone to the saturated zone are a concern at Rainier Mesa and Shoshone Mountain in the Nevada Test Site, Nevada. Where nuclear tests were conducted in the unsaturated zone, contaminants must traverse hundreds of meters of variably saturated rock before they enter the saturated zone in the carbonate rock, where the regional groundwater system has the potential to carry them substantial distances to a location of concern. The unsaturated-zone portion of the contaminant transport path may cause a significant delay, in addition to the time required to travel within the saturated zone, and thus may be important in the overall evaluation of the potential hazard from contamination. Downward contaminant transport through the unsaturated zone occurs through various processes and pathways; this can lead to a broad distribution of contaminant traveltimes, including exceedingly slow and unexpectedly fast extremes. Though the bulk of mobile contaminant arrives between the time-scale end members, the fastest contaminant transport speed, in other words the speed determined by the combination of possible processes and pathways that would bring a measureable quantity of contaminant to the aquifer in the shortest time, carries particular regulatory significance because of its relevance in formulating the most conservative hazard-prevention scenarios. Unsaturated-zone flow is usually modeled as a diffusive process responding to gravity and pressure gradients as mediated by the unsaturated hydraulic properties of the materials traversed. The mathematical formulation of the diffuse-flow concept is known as Richards' equation, which when coupled to a solute transport equation, such as the advection-dispersion equation, provides a framework to simulate contaminant migration in the unsaturated zone. In recent decades awareness has increased that much fluid flow and contaminant transport within the unsaturated

  17. Estimation of unsaturated zone traveltimes for Rainier Mesa and Shoshone Mountain, Nevada Test Site, Nevada, using a source-responsive preferential-flow model

    Energy Technology Data Exchange (ETDEWEB)

    Brian A. Ebel; John R. Nimmo

    2009-09-11

    Traveltimes for contaminant transport by water from a point in the unsaturated zone to the saturated zone are a concern at Rainier Mesa and Shoshone Mountain in the Nevada Test Site, Nevada. Where nuclear tests were conducted in the unsaturated zone, contaminants must traverse hundreds of meters of variably saturated rock before they enter the saturated zone in the carbonate rock, where the regional groundwater system has the potential to carry them substantial distances to a location of concern. The unsaturated-zone portion of the contaminant transport path may cause a significant delay, in addition to the time required to travel within the saturated zone, and thus may be important in the overall evaluation of the potential hazard from contamination. Downward contaminant transport through the unsaturated zone occurs through various processes and pathways; this can lead to a broad distribution of contaminant traveltimes, including exceedingly slow and unexpectedly fast extremes. Though the bulk of mobile contaminant arrives between the time-scale end members, the fastest contaminant transport speed, in other words the speed determined by the combination of possible processes and pathways that would bring a measureable quantity of contaminant to the aquifer in the shortest time, carries particular regulatory significance because of its relevance in formulating the most conservative hazard-prevention scenarios. Unsaturated-zone flow is usually modeled as a diffusive process responding to gravity and pressure gradients as mediated by the unsaturated hydraulic properties of the materials traversed. The mathematical formulation of the diffuse-flow concept is known as Richards' equation, which when coupled to a solute transport equation, such as the advection-dispersion equation, provides a framework to simulate contaminant migration in the unsaturated zone. In recent decades awareness has increased that much fluid flow and contaminant transport within the

  18. Ecology of Anopheline (Diptera, Culicidae, malaria vectors around the Serra da Mesa Reservoir, State of Goiás, Brazil: 1 - Frequency and climatic factors

    Directory of Open Access Journals (Sweden)

    Anthony Érico Guimarães

    Full Text Available The ecology of anopheline species (Diptera, Culicidae was studied in the vicinity of the Serra da Mesa Reservoir, State of Goiás, Brazil. Climatic factors and frequency of anopheline populations were analyzed. Bimonthly human-bait and Shannon trap captures were conducted for 36 consecutive months (January 1997 through December 1999. A total of 5,205 adult anophelines belonging to five species were collected. Anopheles darlingi was the most frequently collected anopheline (61.4%, followed by An. albitarsis s.l. (35.4%, An. triannulatus. (2.5%, An. oswaldoi (0.4%, and An. evansae (0.2%. The water level and vegetation along the banks of the reservoir were crucial to the frequency of the various anopheline species. Climatic factors had a secondary influence. The reservoir's water-level stability, increased frequency of An. darlingi, and the arrival of gold prospectors were responsible for the increase in malaria cases.

  19. Effects of deposition time in chemically deposited ZnS films in acidic solution

    Energy Technology Data Exchange (ETDEWEB)

    Haddad, H.; Chelouche, A., E-mail: azeddinechelouche@gmail.com; Talantikite, D.; Merzouk, H.; Boudjouan, F.; Djouadi, D.

    2015-08-31

    We report an experimental study on the synthesis and characterization of zinc sulfide (ZnS) single layer thin films deposited on glass substrates by chemical bath deposition technique in acidic solution. The effect of deposition time on the microstructure, surface morphology, optical absorption, transmittance, and photoluminescence (PL) was investigated by X-ray diffraction (XRD), scanning electronic microscopy (SEM), UV-Vis–NIR spectrophotometry and photoluminescence (PL) spectroscopy. The results showed that the samples exhibit wurtzite structure and their crystal quality is improved by increasing deposition time. The latter, was found to affect the morphology of the thin films as showed by SEM micrographs. The optical measurements revealed a high transparency in the visible range and a dependence of absorption edge and band gap on deposition time. The room temperature PL spectra indicated that all ZnS grown thin films emit a UV and blue light, while the band intensities are found to be dependent on deposition times. - Highlights: • Single layer ZnS thin films were deposited by CBD in acidic solution at 95 °C. • The effect of deposition time was investigated. • Coexistence of ZnS and ZnO hexagonal structures for time deposition below 2 h • Thicker ZnS films were achieved after monolayer deposition for 5 h. • The highest UV-blue emission observed in thin film deposited at 5 h.

  20. Uraniferous surficial deposits

    International Nuclear Information System (INIS)

    Toens, P.D.; Hambleton-Jones, B.B.

    1980-10-01

    As a result of the discovery of uranium in surficial deposits of Tertiary to Recent age, in Australia and Southern Africa, increasing attention is being paid to the location and understanding of the genesis of these deposits. The paper discusses the definitions and terminology currently in use and a classification of these deposits is presented. It is concluded that in order to obtain a measure of clarity, the terms calcrete, gypcrete and dolocrete should not be used to describe the uraniferous valley-fill deposits of Southern Africa and Australia [af

  1. A review of mineral systems and associated tectonic settings of northern Xinjiang, NW China

    Directory of Open Access Journals (Sweden)

    Franco Pirajno

    2011-04-01

    Full Text Available In this paper we present a review of mineral systems in northern Xinjiang, NW China, focussing on the Tianshan, West and East Junggar and Altay orogenic belts, all of which are part of the greater Central Asian Orogenic Belt (CAOB. The CAOB is a complex collage of ancient microcontinents, island arcs, oceanic plateaux and oceanic plates, which were amalgamated and accreted in Early Palaeozoic to Early Permian times. The establishment of the CAOB collage was followed by strike-slip movements and affected by intraplate magmatism, linked to mantle plume activity, best exemplified by the 250 Ma Siberian Traps and the 280 Ma Tarim event. In northern Xinjiang, there are numerous and economically important mineral systems. In this contribution we describe a selection of representative mineral deposits, including subduction-related porphyry and epithermal deposits, volcanogenic massive sulphides and skarn systems. Shear zone-hosted Au lodes may have first formed as intrusion-related and subsequently re-worked during strike-slip deformation. Intraplate magmatism led to the emplacement of concentrically zoned (Alaskan-style mafic–ultramafic intrusions, many of which host orthomagmatic sulphide deposits. A huge belt of pegmatites in the Altay orogen, locally hosts world-class rare metal deposits. Roll-front, sandstone-hosted U mineralisation completes the rich mineral endowment of the northern Xinjiang terranes.

  2. Sandstone-type uranium deposits

    International Nuclear Information System (INIS)

    Austin, S.R.; D'Andrea, R.F. Jr.

    1978-01-01

    Three overall factors are necessary for formation of uranium deposits in sandstone: a source of uranium, host rocks capable of transmitting uranium-bearing solutions, and a precipitant. Possible sources of uranium in sandstone-type deposits include groundwaters emanating from granitic highlands, arkosic sediments, tuffaceous material within or overlying the host rocks, connate fluids, and overlying black shales. The first three sources are considered the most likely. Host rocks are generally immature sandstones deposited in alluvial-fan, intermontane-basin or marginal-marine environments, but uranium deposits do occur in well-winnowed barrier-bar or eolian sands. Host rocks for uranium deposits generally show coefficients of permeability on the order of 1 to 100 gal/day/ft 2 . Precipitants are normally agents capable of reducing uranium from the uranyl to the uranous state. The association of uranium with organic matter is unequivocal; H 2 S, a powerful reductant, may have been present at the time of formation of some deposits but may go unnoticed today. Vanadium can serve to preserve the tabular characteristics of some deposits in the near-surface environment, but is considered an unlikely primary precipitant for uranium. Uranium deposits in sandstone are divided into two overall types: peneconcordant deposits, which occur in locally reducing environments in otherwise oxidized sandstones; and roll-type deposits, which occur at the margin of an area where an oxidized groundwater has permeated an otherwise reduced sandstone. Uranium deposits are further broken down into four subclasses; these are described

  3. Polymer deposition morphology by electrospray deposition - Modifications through distance variation

    International Nuclear Information System (INIS)

    Altmann, K.; Schulze, R.-D.; Friedrich, J.

    2014-01-01

    Electrospray deposition (ESD) of highly diluted polymers was examined with regard to the deposited surface structure. Only the flight distance (flight time) onto the resulting deposited surface was varied from 20 to 200 mm. An apparatus without any additional heating or gas flows was used. Polyacrylic acid (PAA) and polyallylamine (PAAm) in methanol were deposited on Si wafers. The polymer layers were characterized by scanning electron microscopy, X-ray photoelectron spectroscopy, derivatization reactions and Fourier transform infrared spectroscopy using a grazing incidence unit. SEM images illustrated the changing structures of PAA and PAAm. For PAA the deposited structure changed from a smooth film (20 mm) to a film with individual droplets on the coated surface (100 mm and 200 mm), while for PAAm individual droplets can be seen at all distances. The ESD process with cascades of splitting droplets slows down for PAA after distances greater than 40 mm. In contrast, the ESD process for PAAm is nearly stopped within the first flight distance of 20 mm. Residual solvent analysis showed that most of the solvent evaporated within the first 20 mm capillary-sample distance. - Highlights: • We deposited polyacrylic acid and polyallylamine by electrospray ionization (ESI). • The morphology in dependence of flight distance (20 mm to 200 mm) was analyzed. • The amount of residual solvent after deposition was determined. • ESI-process slows down for polyacrylic acid after 40 mm flight distance. • ESI-Process is complete for polyallylamine within the first 20 mm

  4. "A different kind of beauty": scientific and architectural style in I.M. Pei's Mesa Laboratory and Louis Kahn's Salk Institute.

    Science.gov (United States)

    Leslie, Stuart W

    2008-01-01

    I.M. Pei's Mesa Laboratory for the National Center for Atmospheric Research in Boulder, Colorado, and Louis Kahn's Salk Institute in La Jolla, California, are rare examples of laboratories as celebrated for their architecture as for their scientific contributions. Completed in the mid-1960s, these signature buildings still express the scientific style of their founding directors, Walter Roberts and Jonas Salk. yet in commissioning their laboratories, Roberts and Salk had to work with architects as strong-willed as themselves. A close reading of the two laboratories reveals the ongoing negotiations and tensions in collaborations between visionary scientist and visionary architect. Moreover, Roberts and Salk also had to become architects of atmospheric and biomedical sciences. For laboratory architecture, however flexible in theory, necessarily stabilizes scientific practice, since a philosophy of research is embedded in the very structure of the building and persists far longer than the initial vision and mission that gave it life. Roberts and Salk's experiences suggest that even the most carefully designed laboratories must successfully adapt to new disciplinary configurations, funding opportunities, and research priorities, or risk becoming mere architectural icons.

  5. How deposition parameters control growth dynamics of nc-Si deposited by hot-wire chemical vapor deposition

    International Nuclear Information System (INIS)

    Moutinho, H.R.; To, B.; Jiang, C.-S.; Xu, Y.; Nelson, B.P.; Teplin, C.W.; Jones, K.M.; Perkins, J.; Al-Jassim, M.M.

    2006-01-01

    We studied the growth of silicon films deposited by hot-wire chemical vapor deposition under different values of filament current, substrate temperature, and hydrogen dilution ratio. The physical and electrical properties of the films were studied by Raman spectroscopy, x-ray diffraction, atomic force microscopy, conductive-atomic force microscopy, and transmission electron microscopy. There is an interdependence of the growth parameters, and films grown with different parameters can have similar structures. We discuss why this interdependence occurs and how it influences the properties of the deposited films, as well as the deposition rate. In general, the films have a complex structure, with a mixture of amorphous (220)-oriented crystalline and nanocrystalline phases present in most cases. The amount of each phase can be controlled by the variation of one or more of the growth parameters at a time

  6. Patterned deposition by atmospheric pressure plasma-enhanced spatial atomic layer deposition

    NARCIS (Netherlands)

    Poodt, P.; Kniknie, B.J.; Branca, A.; Winands, G.J.J.; Roozeboom, F.

    2011-01-01

    An atmospheric pressure plasma enhanced atomic layer deposition reactor has been developed, to deposit Al2O3 films from trimethyl aluminum and an He/O2 plasma. This technique can be used for 2D patterned deposition in a single in-line process by making use of switched localized plasma sources. It

  7. MAPLE deposition of nanomaterials

    International Nuclear Information System (INIS)

    Caricato, A.P.; Arima, V.; Catalano, M.; Cesaria, M.; Cozzoli, P.D.; Martino, M.; Taurino, A.; Rella, R.; Scarfiello, R.; Tunno, T.; Zacheo, A.

    2014-01-01

    The matrix-assisted pulsed laser evaporation (MAPLE) has been recently exploited for depositing films of nanomaterials by combining the advantages of colloidal inorganic nanoparticles and laser-based techniques. MAPLE-deposition of nanomaterials meeting applicative purposes demands their peculiar properties to be taken into account while planning depositions to guarantee a congruent transfer (in terms of crystal structure and geometric features) and explain the deposition outcome. In particular, since nanofluids can enhance thermal conductivity with respect to conventional fluids, laser-induced heating can induce different ablation thermal regimes as compared to the MAPLE-treatment of soft materials. Moreover, nanoparticles exhibit lower melting temperatures and can experience pre-melting phenomena as compared to their bulk counterparts, which could easily induce shape and or crystal phase modification of the material to be deposited even at very low fluences. In this complex scenario, this review paper focuses on examples of MAPLE-depositions of size and shape controlled nanoparticles for different applications highlights advantages and challenges of the MAPLE-technique. The influence of the deposition parameters on the physical mechanisms which govern the deposition process is discussed.

  8. MAPLE deposition of nanomaterials

    Energy Technology Data Exchange (ETDEWEB)

    Caricato, A.P., E-mail: annapaola.caricato@le.infn.it [Department of Mathematics and Physics “E. De Giorgi”, University of Salento, Via Arnesano, I-73100 Lecce (Italy); Arima, V.; Catalano, M. [National Nanotechnology Laboratory (NNL), CNR Istituto Nanoscienze, c/o Distretto Tecnologico, Via Arnesano n. 16, I-73100 Lecce (Italy); Cesaria, M. [Department of Mathematics and Physics “E. De Giorgi”, University of Salento, Via Arnesano, I-73100 Lecce (Italy); Cozzoli, P.D. [Department of Mathematics and Physics “E. De Giorgi”, University of Salento, Via Arnesano, I-73100 Lecce (Italy); National Nanotechnology Laboratory (NNL), CNR Istituto Nanoscienze, c/o Distretto Tecnologico, Via Arnesano n. 16, I-73100 Lecce (Italy); Martino, M. [Department of Mathematics and Physics “E. De Giorgi”, University of Salento, Via Arnesano, I-73100 Lecce (Italy); Taurino, A.; Rella, R. [Institute for Microelectronics and Microsystems, IMM-CNR, Via Monteroni, I-73100 Lecce (Italy); Scarfiello, R. [National Nanotechnology Laboratory (NNL), CNR Istituto Nanoscienze, c/o Distretto Tecnologico, Via Arnesano n. 16, I-73100 Lecce (Italy); Tunno, T. [Department of Mathematics and Physics “E. De Giorgi”, University of Salento, Via Arnesano, I-73100 Lecce (Italy); Zacheo, A. [Department of Mathematics and Physics “E. De Giorgi”, University of Salento, Via Arnesano, I-73100 Lecce (Italy); National Nanotechnology Laboratory (NNL), CNR Istituto Nanoscienze, c/o Distretto Tecnologico, Via Arnesano n. 16, I-73100 Lecce (Italy)

    2014-05-01

    The matrix-assisted pulsed laser evaporation (MAPLE) has been recently exploited for depositing films of nanomaterials by combining the advantages of colloidal inorganic nanoparticles and laser-based techniques. MAPLE-deposition of nanomaterials meeting applicative purposes demands their peculiar properties to be taken into account while planning depositions to guarantee a congruent transfer (in terms of crystal structure and geometric features) and explain the deposition outcome. In particular, since nanofluids can enhance thermal conductivity with respect to conventional fluids, laser-induced heating can induce different ablation thermal regimes as compared to the MAPLE-treatment of soft materials. Moreover, nanoparticles exhibit lower melting temperatures and can experience pre-melting phenomena as compared to their bulk counterparts, which could easily induce shape and or crystal phase modification of the material to be deposited even at very low fluences. In this complex scenario, this review paper focuses on examples of MAPLE-depositions of size and shape controlled nanoparticles for different applications highlights advantages and challenges of the MAPLE-technique. The influence of the deposition parameters on the physical mechanisms which govern the deposition process is discussed.

  9. Tracing low-temperature aqueous metal migration in mineralized watersheds with Cu isotope fractionation

    International Nuclear Information System (INIS)

    Mathur, R.; Munk, L.A.; Townley, B.; Gou, K.Y.; Gómez Miguélez, N.; Titley, S.; Chen, G.G.; Song, S.; Reich, M.; Tornos, F.; Ruiz, J.

    2014-01-01

    Highlights: • Cu isotope fractionation of ores and waters identifies copper sulfide weathering. • Redox reactions cause isotopic shift measured in areas of sulfide weathering. • Consistent isotope signature in different deposit, climate, or concentration. - Abstract: Copper isotope signatures in waters emanating from mineralized watersheds provide evidence for the source aqueous copper in solution. Low-temperature aqueous oxidation of Cu sulfide minerals produces significant copper isotopic fractionation between solutions and residues. Abiotic experimental data of fractionation (defined as Δ liquid–solid ‰ = δ 65 Cu liquid − δ 65 Cu solid ) are on the order of 1–3‰ and are unique for copper rich-sulfide minerals. Data presented here from ores and waters within defined boundaries of porphyry copper, massive sulfide, skarn, and epithermal ore deposits mimic abiotic experiments. Thus, the oxidation of sulfide minerals appears to cause the signatures in the waters although significant biological, temperature, and pH variations exist in the fluids. Regardless of the deposit type, water type, concentration of Cu in solution, or location, the data provide a means to trace sources of metals in solutions. This relationship allows for tracking sources and degree of metal migration in low temperature aqueous systems and has direct application to exploration geology and environmental geochemistry

  10. ITO thin films deposited by advanced pulsed laser deposition

    International Nuclear Information System (INIS)

    Viespe, Cristian; Nicolae, Ionut; Sima, Cornelia; Grigoriu, Constantin; Medianu, Rares

    2007-01-01

    Indium tin oxide thin films were deposited by computer assisted advanced PLD method in order to obtain transparent, conductive and homogeneous films on a large area. The films were deposited on glass substrates. We studied the influence of the temperature (room temperature (RT)-180 deg. C), pressure (1-6 x 10 -2 Torr), laser fluence (1-4 J/cm 2 ) and wavelength (266-355 nm) on the film properties. The deposition rate, roughness, film structure, optical transmission, electrical conductivity measurements were done. We deposited uniform ITO thin films (thickness 100-600 nm, roughness 5-10 nm) between RT and 180 deg. C on a large area (5 x 5 cm 2 ). The films have electrical resistivity of 8 x 10 -4 Ω cm at RT, 5 x 10 -4 Ω cm at 180 deg. C and an optical transmission in the visible range, around 89%

  11. Impurities in chromium deposits produced by electroplating and physical vapor deposition

    Energy Technology Data Exchange (ETDEWEB)

    Dini, J.W.

    1994-05-01

    Impurity contents in electrodeposited (hexavalent and trivalent) chromium deposits and physically vapor deposited (thermal evaporation, electron beam evaporation and rf-sputtering) were compared. Oxygen is the key impurity obtained in electrodeposited films but it can be minimized in hexavalent plating solutions by operating at high temperature, e. g., 85 C. Electrodeposits produced in trivalent chromium plating solutions and physically vapor deposited films have much higher oxygen contents than electrodeposits produced in hexavalent chromium solutions operated at temperatures around 85 C. Depending on the target material used for physically vapor deposited films, these films can also have high amounts of other impurities.

  12. Oxygen Barrier Coating Deposited by Novel Plasma-enhanced Chemical Vapor Deposition

    DEFF Research Database (Denmark)

    Jiang, Juan; Benter, M.; Taboryski, Rafael Jozef

    2010-01-01

    We report the use of a novel plasma-enhanced chemical vapor deposition chamber with coaxial electrode geometry for the SiOx deposition. This novel plasma setup exploits the diffusion of electrons through the inner most electrode to the interior samples space as the major energy source. This confi......We report the use of a novel plasma-enhanced chemical vapor deposition chamber with coaxial electrode geometry for the SiOx deposition. This novel plasma setup exploits the diffusion of electrons through the inner most electrode to the interior samples space as the major energy source...... effect of single-layer coatings deposited under different reaction conditions was studied. The coating thickness and the carbon content in the coatings were found to be the critical parameters for the barrier property. The novel barrier coating was applied on different polymeric materials...

  13. Deposition Measurements in NSTX

    Science.gov (United States)

    Skinner, C. H.; Kugel, H. W.; Hogan, J. T.; Wampler, W. R.

    2004-11-01

    Two quartz microbalances have been used to record deposition on the National Spherical Torus Experiment. The experimental configuration mimics a typical diagnostic window or mirror. An RS232 link was used to acquire the quartz crystal frequency and the deposited thickness was recorded continuously with 0.01 nm resolution. Nuclear Reaction Analysis of the deposit was consistent with the measurement of the total deposited mass from the change in crystal frequency. We will present measurements of the variation of deposition with plasma conditions. The transport of carbon impurities in NSTX has been modelled with the BBQ code. Preliminary calculations indicated a negligible fraction of carbon generated at the divertor plates in quiescent discharges directly reaches the outer wall, and that transient events are responsible for the deposition.

  14. Shedding of ash deposits

    DEFF Research Database (Denmark)

    Zbogar, Ana; Frandsen, Flemming; Jensen, Peter Arendt

    2009-01-01

    Ash deposits formed during fuel thermal conversion and located on furnace walls and on convective pass tubes, may seriously inhibit the transfer of heat to the working fluid and hence reduce the overall process efficiency. Combustion of biomass causes formation of large quantities of troublesome...... ash deposits which contain significant concentrations of alkali, and earth-alkali metals. The specific composition of biomass deposits give different characteristics as compared to coal ash deposits, i.e. different physical significance of the deposition mechanisms, lower melting temperatures, etc....... Low melting temperatures make straw ashes especially troublesome, since their stickiness is higher at lower temperatures, compared to coal ashes. Increased stickiness will eventually lead to a higher collection efficiency of incoming ash particles, meaning that the deposit may grow even faster...

  15. Proterozoic intracontinental basin succession in the western margin of the São Francisco Craton: Constraints from detrital zircon geochronology

    Science.gov (United States)

    Martins-Ferreira, Marco Antonio Caçador; Chemale, Farid, Jr.; Dias, Airton Natanael Coelho; Campos, José Eloi Guimarães

    2018-01-01

    The age and stratigraphic position of Paleoproterozoic to Mesoproterozoic covers that occur along the western border of the São Francisco Craton (SFC) are still uncertain. Based on detailed sedimentological and stratigraphic survey, combined with U-Pb and Lu-Hf zircon dating, we present a new proposal for the stratigraphy and correlation with similar sequences, situated in other regions of the SFC, the Chapada Diamantina and Northern Espinhaço. Our study demonstrates that the so-called Traíras Formation (Araí Group) has a maximum depositional age of 1543 ± 31 Ma. The zircon distribution pattern shows a dominant Rhyacian source and minor contribution of Statherian, Calymmian, Neoarchean and Paleoarchean sources. The Rhyacian zircon grains have dominant positive εHf (t) signature, suggesting a large contribution from the juvenile Paleoproterozoic terranes, most probably from the Goiás Massif, located west of the study area. The Calymmian maximum depositional age, calculated for the upper Araí Group (Traíras Formation), leads to the conclusion that the Serra da Mesa Group (ca. 1.55 Ga maximum depositional age) and the Traíras Formation have coexisted in time, possibly forming a larger sag basin, although laterally heterogeneous. The data presented also allow a new geotectonic interpretation for the Goiás Massif, since it necessarily had to be connected to the São Francisco Craton during the Mesoproterozoic. This excludes the possibility that this massif was accreted to the São Francisco Craton in the Brasiliano Collage, as previously believed. The study also sheds light to the always debated tectonic relationship between the Serra da Mesa Granite (intrusive or basement) and Serra da Mesa Group (ca. 1.57 crystallization age and 1.55 Ga maximum depositional age, respectively). Furthermore, based on the new data, we present a stratigraphic revision for the actual Araí and Paranoá groups, proposing to raise the Traíras Formation to group status and its

  16. Urban wet deposition nitrate: a comparison to non-urban deposition

    International Nuclear Information System (INIS)

    Schultz, J.A.M.

    1994-01-01

    The concentration of nitrate in both wet and dry deposition has both increased historically and currently, and recently parallels emissions in NO x . Since NO x is produced in amounts comparable to SO 2 , it is an important contributor to acid deposition, and is produced in higher amounts in urban areas due to concentrated sources. Prior to to this study, national acid deposition monitoring networks in the United States have been and remain established in non-urban areas. This research study consisted of a comparison of precipitation sampling and analysis of wet deposition nitrate and pH for each deposition event in each of two urban sites over a 15 mo period. Also, a comparison of urban data and data generated at a nearby non-urban NADP site was made by examination of both monthly and seasonal data. This research suggests that national monitoring programs should consider inclusion of urban and non-urban monitoring sites in order to achieve a more representative regional assessment. 24 refs., 2 figs., 2 tabs

  17. The algal growth-limiting nutrient of lakes located at Mexico’s Mesa Central

    Directory of Open Access Journals (Sweden)

    Fernando W. Bernal-Brooks

    2016-03-01

    Full Text Available This paper reports on the algal growth-limiting nutrients of five lakes located on Mexico’s Mesa Central - a topic poorly known in the regional limnology of Mexico. The five case studies involved three contiguous watersheds of Michoacán State and provided a trophic state variation from mesotrophic to hypereutrophic; the case studies included Lakes Zirahuén, Pátzcuaro, Teremendo, Cuitzeo and the Cointzio Reservoir. The fieldwork involved the collection of physical and chemical data (including nutrients from each case study during the dry and rainy seasons of 2010. Additionally, water samples (1 L were obtained and filtered (0.45 µm in the laboratory to keep the nutrient content available for bioassays. The chemical analyses suggested a phosphorus (P limitation in the Cointzio Reservoir, Lake Teremendo and Lake Zirahuén relative to an N:P>16:1. There was a nitrogen (N limitation at three sampling stations of Lake Pátzcuaro, with an N:P<16:1. As result of the bioassays conducted in July 2012, the Cointzio Reservoir and Lake Teremendo appeared to be P-limited and Lake Pátzcuaro appeared to be N-limited at three sampling stations. Lake Zirahuén showed seasonal variation, with an N limitation during the dry season and a P limitation during the wet season. Those cases with similar results from both methods confirmed the limiting nutrient identification. Lake Cuitzeo, Lake Zirahuén (dry season, and the shallowest sampling station in Lake Pátzcuaro produced unclear results because of divergent outcomes. In terms of the algal growth potential, the Cointzio Reservoir remained unaltered from one season to the next. However, for most of the lakes (with the exception of Lake Pátzcuaro sites 2 and 4, the rainy season provided a dilution effect. Effective lake management depends on a clear recognition of such elements that are in control of the aquatic productivity. In the area of Michoacán, both N and P may act as limiting nutrients.

  18. Temperature dependent characterization of gallium arsenide X-ray mesa p-i-n photodiodes

    Energy Technology Data Exchange (ETDEWEB)

    Lioliou, G., E-mail: G.Lioliou@sussex.ac.uk; Barnett, A. M. [Semiconductor Materials and Devices Laboratory, Department Engineering and Design, School of Engineering and Informatics, University of Sussex, Falmer, Brighton BN1 9QT (United Kingdom); Meng, X.; Ng, J. S. [Department of Electronic and Electrical Engineering, University of Sheffield, Mappin Street, Sheffield S1 3JD (United Kingdom)

    2016-03-28

    Electrical characterization of two GaAs p{sup +}-i-n{sup +} mesa X-ray photodiodes over the temperature range 0 °C to 120 °C together with characterization of one of the diodes as an X-ray detector over the temperature range 0 °C to 60 °C is reported as part of the development of photon counting X-ray spectroscopic systems for harsh environments. The randomly selected diodes were fully etched and unpassivated. The diodes were 200 μm in diameter and had 7 μm thick i layers. The leakage current density was found to increase from (3 ± 1) nA/cm{sup −2} at 0 °C to (24.36 ± 0.05) μA/cm{sup −2} at 120 °C for D1 and from a current density smaller than the uncertainty (0.2 ± 1.2) nA/cm{sup −2} at 0 °C to (9.39 ± 0.02) μA/cm{sup −2} at 120 °C for D2 at the maximum investigated reverse bias (15 V). The best energy resolution (FWHM at 5.9 keV) was achieved at 5 V reverse bias, at each temperature; 730 eV at 0 °C, 750 eV at 20 °C, 770 eV at 40 °C, and 840 eV at 60 °C. It was found that the parallel white noise was the main source of the photopeak broadening only when the detector operated at 60 °C, at 5 V, 10 V, and 15 V reverse bias and at long shaping times (>5 μs), whereas the sum of the dielectric noise and charge trapping noise was the dominant source of noise for all the other spectra.

  19. 76 FR 41392 - Interest on Deposits; Deposit Insurance Coverage

    Science.gov (United States)

    2011-07-14

    ... banks' funding costs and also allow them to plan business growth more dependably and rigorously... of business deposits by offering continually higher rates of interest. Three of the four contended... deposits. They reasoned that large banks will offer high rates of interest and lure away business...

  20. The newly-discovered Late Cretaceous igneous rocks in the Nuocang district: Products of ancient crust melting trigged by Neo-Tethyan slab rollback in the western Gangdese

    Science.gov (United States)

    Jiang, Jun-Sheng; Zheng, You-Ye; Gao, Shun-Bao; Zhang, Yong-Chao; Huang, Jian; Liu, Jun; Wu, Song; Xu, Jing; Huang, Liang-Liang

    2018-05-01

    The newly discovered polymetallic Nuocang Pb-Zn skarn deposit is located in the southern Lhasa subterrane, western Gangdese, Tibet. The orebodies occur primarily at the contact zone between the Angjie Formation and the Linzizong volcanic rocks of Dianzhong Formation (LDF) that are dominated by basaltic andesitic tuff and rhyolite. Zircon U-Pb dating for two granite porphyries yield ages of 72.4 ± 0.2 Ma and 73.4 ± 0.9 Ma, which are different from the ages ( 69-60 Ma) of the LDF in the eastern Gangdese. The basaltic andesite tuff at Nuocang exhibits enrichment of MgO, TiO2, LILE, and LREE, with a relative depletion of SiO2, K2O, HFSE, and HREE, low Sr/Y ratios (32.9-38.0), and weak negative Eu anomalies (mean 0.86). They have 87Sr/86Sr(i) from 0.70695 to 0.70807 and εNd(t) values between -4.3 and -5.9. These features are similar to the Linzizong volcanic rocks of Dianzhong Formation in the Linzhou basin, indicating that they were associated with partial melting of mantle wedge mixing with 25-35% ancient Lhasa terrane basement. The rhyolite and granite porphyry show high SiO2 and K2O, and low Sr/Y ratio (1.2-9.9), enrichment of LILE and LREE and strong depletion of the HFSEs. They have pronounced negative Eu anomalies (mean 0.46), and εHf (t) values of the granite porphyry zircons range from -22.0 to -6.0. All these features suggest that they are the product of anatexis of ancient crustal materials heated by mantle-derived magma, the latter derived from Neo-Tethyan slab dehydration mechanisms. Combined with the previous geochronological and geochemical data, we proposed that the Nuocang district of western Gangdese in the southern Lhasa subterrane contains an ancient block, and the igneous rocks here were triggered by the Neo-Tethyan slab rollback starting at 82 Ma. The western Gangdese contains more ancient continental crustal materials and Late Cretaceous-Eocene Linzizong volcanic rocks and coeval intrusions than in the eastern Gangdese. Thus the western

  1. Atmospheric deposition 2000. NOVA 2003; Atmosfaerisk deposition 2000. NOVA 2003

    Energy Technology Data Exchange (ETDEWEB)

    Ellermann, T.; Hertel, O.; Hovmand, M.F.; Kemp, K.; Skjoeth, C.A.

    2001-11-01

    This report presents measurements and calculations from the atmospheric part of NOVA 2003 and covers results for 2000. It summarises the main results concerning concentrations and depositions of nitrogen, phosphorus and sulphur compounds related to eutrophication and acidification. Depositions of atmospheric compounds to Danish marine waters as well as land surface are presented. Measurements: In 2000 the monitoring program consisted of eight stations where wet deposition of ammonium, nitrate, phosphate (semi quantitatively) and sulphate were measured using bulk precipitation samplers. Six of the stations had in addition measurements of atmospheric content of A, nitrogen, phosphorus, and sulphur compounds in gas and particulate phase carried out by use of filter pack samplers. Filters were analysed at the National Environmental Research Institute. Furthermore nitrogen dioxide were measured using nitrogen dioxide filter samplers and monitors. Model calculations: The measurements in the monitoring program were supplemented with model calculations of concentrations and depositions of nitrogen and sulphur compounds to Danish land surface, marine waters, fjords and bays using the ACDEP model (Atmospheric Chemistry and Deposition). The model is a so-called trajectory model and simulates the physical and chemical processes in the atmosphere using meteorological and emission data as input. The advantage of combining measurements with model calculations is that the strengths of both methods is obtained. Conclusions concerning: 1) actual concentration levels at the monitoring stations, 2) deposition at the monitoring stations, 3) seasonal variations and 4) long term trends in concentrations and depositions are mainly based on the direct measurements. These are furthermore used to validate the results of the model calculations. Calculations and conclusions concerning: 1) depositions to land surface and to the individual marine water, 2) contributions from different emission

  2. Mechanical characteristics of a tool steel layer deposited by using direct energy deposition

    Science.gov (United States)

    Baek, Gyeong Yun; Shin, Gwang Yong; Lee, Eun Mi; Shim, Do Sik; Lee, Ki Yong; Yoon, Hi-Seak; Kim, Myoung Ho

    2017-07-01

    This study focuses on the mechanical characteristics of layered tool steel deposited using direct energy deposition (DED) technology. In the DED technique, a laser beam bonds injected metal powder and a thin layer of substrate via melting. In this study, AISI D2 substrate was hardfaced with AISI H13 and M2 metal powders for mechanical testing. The mechanical and metallurgical characteristics of each specimen were investigated via microstructure observation and hardness, wear, and impact tests. The obtained characteristics were compared with those of heat-treated tool steel. The microstructures of the H13- and M2-deposited specimens show fine cellular-dendrite solidification structures due to melting and subsequent rapid cooling. Moreover, the cellular grains of the deposited M2 layer were smaller than those of the H13 structure. The hardness and wear resistance were most improved in the M2-deposited specimen, yet the H13-deposited specimen had higher fracture toughness than the M2-deposited specimen and heat-treated D2.

  3. Exogenous deposits

    International Nuclear Information System (INIS)

    Khasanov, A.Kh.

    1988-01-01

    Exogenous deposits forming as a result of complex exogenous processes, passed under the influence of outside forces on the Earth surface. To them relate physical and chemical weathering, decomposition and decay of mineral masses, redistribution and transportation of material, forming and deposit of new minerals and ores steady on the earth surface conditions

  4. Electro-Deposition Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — The electro-deposition laboratory can electro-deposit various coatings onto small test samples and bench level prototypes. This facility provides the foundation for...

  5. Breaking Through the Multi-Mesa-Channel Width Limited of Normally Off GaN HEMTs Through Modulation of the Via-Hole-Length

    Science.gov (United States)

    Chien, Cheng-Yen; Wu, Wen-Hsin; You, Yao-Hong; Lin, Jun-Huei; Lee, Chia-Yu; Hsu, Wen-Ching; Kuan, Chieh-Hsiung; Lin, Ray-Ming

    2017-06-01

    We present new normally off GaN high-electron-mobility transistors (HEMTs) that overcome the typical limitations in multi-mesa-channel (MMC) width through modulation of the via-hole-length to regulate the charge neutrality screen effect. We have prepared enhancement-mode (E-mode) GaN HEMTs having widths of up to 300 nm, based on an enhanced surface pinning effect. E-mode GaN HEMTs having MMC structures and widths as well as via-hole-lengths of 100 nm/2 μm and 300 nm/6 μm, respectively, exhibited positive threshold voltages ( V th) of 0.79 and 0.46 V, respectively. The on-resistances of the MMC and via-hole-length structures were lower than those of typical tri-gate nanoribbon GaN HEMTs. In addition, the devices not only achieved the E-mode but also improved the power performance of the GaN HEMTs and effectively mitigated the device thermal effect. We controlled the via-hole-length sidewall surface pinning effect to obtain the E-mode GaN HEMTs. Our findings suggest that via-hole-length normally off GaN HEMTs have great potential for use in next-generation power electronics.

  6. Athabasca basin unconformity-type uranium deposits. A special class of sandstone-type deposits

    International Nuclear Information System (INIS)

    Hoeve, J.

    1980-01-01

    Two major episodes of uranium metallogenesis are recognized in Northern Saskatchewan. The first is of late-Hudsonian age and gave rise to metamorphic-hydrothermal pitchblende deposits of simple mineralogy at Beaverlodge (primary mineralization: 1780+-20 m.y.). The second and more important episode of approximately Grenvillian age rendered unconformity-type deposits in the Athabasca Basin (primary mineralization: 1000-1300 m.y.). The late-Hudsonian deposits at Beaverlodge were overprinted by this second event and new deposits of complex mineralogy were formed in that area. The metallogenetic importance of a third and much later episode which gave rise to mineralization within the Athabasca Formation is uncertain at the moment. With regards to metallogenesis of the unconformity-type deposits, presently available evidence favours a diagenetic-hydrothermal rather than a near-surface supergene or a magmatic/metamorphic hydrothermal model. The diagenetic-hydrothermal model relates uranium mineralization to 'red bed-type' diagenetic processes in the Athabasca Formation involving post-depositional oxidation and leaching, which continued for several hundred million years after deposition. Ore deposits were formed by interaction, under conditions of deep burial at elevated temperatures and pressures, of a uraniferous oxidizing Athabasca aquifer with reducing, graphite-bearing, metamorphic rocks of the basin floor. The large-scale convection required for such interaction may have been induced by mafic magmatic activity coeval with the episode of mineralization. The diagenetic-hydrothermal model displays close similarities with metallogenetic models developed for certain sandstone-type deposits. (author)

  7. Native gold from the Inagli Pt-Au placer deposit (the Aldan Shield, Russia): geochemical characteristics and implications for possible bedrock sources

    Science.gov (United States)

    Svetlitskaya, Tatyana V.; Nevolko, Peter A.; Kolpakov, Vladislav V.; Tolstykh, Nadezhda D.

    2018-03-01

    The Inagli alluvial Pt-Au placer deposit in the Republic of Sakha (Yakutia), Russia, is linked to the Inagli massif, one of the several Uralian-Alaskan-type alkaline-ultrabasic complexes in the Aldan Shield. Gold from the placer is heterogeneous in composition and is represented by three types. Type 1 gold is the most abundant and is characterized by simple Au-Ag alloys with 4-34 wt% Ag, low Cu (up to 0.08 wt%) and negligible Hg, Pt, and Pd contents, and silver-tellurium sulfosalts (Ag-Cu-Te-S-As compounds) in the inclusion suite. Silicate inclusions are biotite, K-feldspar, Fe-Mg amphibole, chlorite, plagioclase, Fe-Mg pyroxene, zircon, and titanite. Distinctive features of this gold type are most similar to those derived from low-sulfidation systems linked to iron oxide copper-gold or iron skarn types of mineralization. The bedrock source of type 1 gold could be related with monzonite to syenite intrusions surrounding the Inagli massif. Distinctive features of type 2 gold include a wide discontinuous range of Ag content (1-18 wt%), elevated Cu (up to 0.5 wt%), and occasional Pd (up to 0.3 wt%) levels, non-detectable Pt and Hg contents, and rare inclusions of simple sulfides (digenite, pyrrhotite) and Na amphibole. Type 3 gold is distinguished by a narrow range in Ag content (5-8 wt%), elevated Hg (0.5-1 wt%) contents, negligible Cu, Pt and Pd levels, and Au-Pb compounds + K-feldspar inclusions. Microchemical characteristics of type 2 and type 3 gold are interpreted as suggestive of an alkaline-magmatic-related fluid. Based on the grain morphology and microchemical signatures, potential bedrock sources for both gold types could be related to the numerous alkaline veins and potassic alteration zones within the dunite core. A comparison of the Inagli and the Kondyor placer gold allows to generate distinctive generic signatures for gold from Uralian-Alaskan-type alkaline-ultrabasic complexes in the Aldan Shield.

  8. World Distribution of Uranium Deposits (UDEPO) with uranium deposit classification. 2009 ed

    International Nuclear Information System (INIS)

    2009-10-01

    The World Distribution of Uranium Deposits (UDEPO) database provides general, technical and geological information, including references, about the worldwide uranium deposits. UDEPO has been published on the internet which allows the users to register freely and to work with datasets (http://www-nfcis.iaea.org). The UDEPO web site is designed to allow users to retrieve data sets on a variety of deposit related topics ranging from specific information on individual uranium deposits to statistical information on uranium deposits worldwide. The basic building blocks for the UDEPO database are the more than 900 individual deposits for which information is available in the database. The database is arranged in a relational database format which has one main table and a number of associated tables. Structured nature of the database allows filtering and querying the database in more systematic way. The web site provides filtering and navigation to the data from the database. It has also a statistical tool which provides summary information on number of deposits and uranium resources by type and status, and by country and status. In this respect and with regard to the data presented, the UDEPO database is a unique database which provides freely accessible information on worldwide uranium deposits. Although a great effort is spent to have complete and accurate database, the users should take into consideration that there still might be missing or outdated data for individual deposits due to the rapid changes in the uranium industry due to the new exploration works which are ongoing everyday. This document and its supplementary CD-ROM represent a snapshot of the status of the database as of the end of 2008. However, the database is being continuously updated and the latest updates and additions can be accessed from the database web site (http://wwwnfcis.iaea.org)

  9. Geological factors of deposit formation

    International Nuclear Information System (INIS)

    Grushevoj, G.V.

    1980-01-01

    Geologic factors of hydrogenic uranium deposit formation are considered. Structural, formation and lithological-facies factors of deposit formation, connected with zones of stratal oxidation, are characterized. Peculiarities of deposit localization, connected with orogenic structures of Mesozoic and lenozoic age, are described. It is noted that deposits of anagenous group are widely spread in Paleozoic formations, infiltration uranium deposits are localized mainly in Cenozoic sediments, while uranium mineralization both anagenous and infiltration groups are widely developed in Mesozoic sediments. Anagenous deposits were formed in non-oxygen situation, their age varies from 200 to 55 mln years. Infiltration deposit formation is determined by asymmetric oxidation zonation, their age varies from 10 - 40 mln years to dozens of thousand years [ru

  10. Deposit3D: a tool for automating structure depositions to the Protein Data Bank

    Energy Technology Data Exchange (ETDEWEB)

    Badger, J., E-mail: jbadger@active-sight.com; Hendle, J.; Burley, S. K.; Kissinger, C. R. [SGX Inc., 10505 Roselle Street, San Diego, CA 92121 (United States)

    2005-09-01

    This paper describes a Python script that may be used to gather all required structure-annotation information into an mmCIF file for upload through the RCSB PDB ADIT structure-deposition interface. Almost all successful protein structure-determination projects in the public sector culminate in a structure deposition to the Protein Data Bank (PDB). In order to expedite the deposition proces, Deposit3D has been developed. This command-line script calculates or gathers all the required structure-deposition information and outputs this data into a mmCIF file for subsequent upload through the RCSB PDB ADIT interface. Deposit3D might be particularly useful for structural genomics pipeline projects because it allows workers involved with various stages of a structure-determination project to pool their different categories of annotation information before starting a deposition session.

  11. Deposit3D: a tool for automating structure depositions to the Protein Data Bank

    International Nuclear Information System (INIS)

    Badger, J.; Hendle, J.; Burley, S. K.; Kissinger, C. R.

    2005-01-01

    This paper describes a Python script that may be used to gather all required structure-annotation information into an mmCIF file for upload through the RCSB PDB ADIT structure-deposition interface. Almost all successful protein structure-determination projects in the public sector culminate in a structure deposition to the Protein Data Bank (PDB). In order to expedite the deposition proces, Deposit3D has been developed. This command-line script calculates or gathers all the required structure-deposition information and outputs this data into a mmCIF file for subsequent upload through the RCSB PDB ADIT interface. Deposit3D might be particularly useful for structural genomics pipeline projects because it allows workers involved with various stages of a structure-determination project to pool their different categories of annotation information before starting a deposition session

  12. Stratigraphic implications of uranium deposits

    International Nuclear Information System (INIS)

    Langford, F.F.

    1980-01-01

    One of the most consistent characteristics of economic uranium deposits is their restricted stratigraphic distribution. Uraninite deposited with direct igneous affiliation contains thorium, whereas chemical precipitates in sedimentary rocks are characterized by thorium-free primary uranium minerals with vanadium and selenium. In marine sediments, these minerals form low-grade disseminations; but in terrestrial sediments, chiefly fluvial sandstones, the concentration of uranium varies widely, with the high-grade portions constituting ore. Pitchblende vein deposits not only exhibit the same chemical characteristics as the Colorado-type sandstone deposits, but they have a stratigraphically consistent position at unconformities covered by fluvial sandstones. If deposits in such diverse situations have critical features in common, they are likely to have had many features of their origin in common. Thus, vein deposits in Saskatchewan and Australia may have analogues in areas that contain Colorado-type sandstone deposits. In New Mexico, the presence of continental sandstones with peneconformable uranium deposits should also indicate good prospecting ground for unconformity-type vein deposits. All unconformities within the periods of continental deposition ranging from Permian to Cretaceous should have uranium potential. Some situations, such as the onlap of the Abo Formation onto Precambrian basement in the Zuni Mountains, may be directly comparable to Saskatchewan deposition. However, uranium occurrences in the upper part of the Entrada Sandstone suggest that unconformities underlain by sedimentary rocks may also be exploration targets

  13. Valoração dos atributos de qualidade do tomate de mesa: um estudo com atacadistas da CEAGESP Valuation of the quality attributes of tomato for fresh market: a study with CEAGESP wholesalers

    Directory of Open Access Journals (Sweden)

    Sabrina L de Oliveira

    2012-06-01

    Full Text Available A grande variação no valor do tomate de mesa, do mesmo grupo varietal, mesma classificação e no mesmo dia de comercialização, no mercado atacadista da CEAGESP, tem entre suas causas mais importantes a diferença de qualidade nos atributos destes frutos. O objetivo deste trabalho foi criar uma ferramenta de avaliação dos atributos de qualidade considerados importantes para o tomate de mesa e, a partir da avaliação, apontar os mais relevantes na diferença de valor praticado na comercialização da CEAGESP. Primeiramente, foram levantados os principais atributos que determinam a qualidade do tomate de mesa a partir de entrevista com agentes de comercialização de tomate da CEAGESP. A partir deste levantamento, foi criado um gabarito de avaliação visual da qualidade. Por fim, foram levantados os lotes de tomate de mesa de preço máximo e os de preço mínimo para três classificações (graúdo, médio e miúdo comercializados no mesmo dia, avaliando-se os seus atributos de qualidade por dois sistemas: sistema I - avaliação dos atributos de qualidade por meio de notas de desempenho de acordo com o gabarito, e o sistema II - levantamento da frequência de ocorrência de cada atributo avaliado no lote de tomate. Os atributos que determinam a qualidade do tomate, segundo os agentes de comercialização de tomate da CEAGESP, são: o tamanho (tipo ou calibre, a coloração do fruto, a ausência de defeitos, durabilidade, embalagem e sabor. Os atributos determinantes na variação de preços avaliados pelo sistema I são embalagens paletizáveis e embalagens que proporcionem um adequado empilhamento, enquanto que, para o sistema II, estes atributos são: frutos sem danos superficiais de casca e proteção adequada da embalagem contra injúrias mecânicas.The great variation in the value of tomato from the same variety group, same classification and on the same day of marketing, registered by the Terminal Market of CEAGESP, were related to

  14. Valoración del paisaje y evaluación del potencial interpretativo como herramienta para el turismo sostenible en el Ecoparque Las Monjas (La Mesa, Cundinamarca

    Directory of Open Access Journals (Sweden)

    Alejandra Cecilia Reyes Palacios

    2017-01-01

    Full Text Available La inspección de policía La Esperanza, en la Mesa (Cundinamarca con su belleza natural -enmarcada por la pureza y abundancia de sus aguas, las formas de su paisaje, la biodiversidad de flora y fauna-, ofrece el escenario propicio para el desarrollo ecoturístico de la región. Inicialmente, se caracterizó el paisaje del Ecoparque Las Monjas, después se calculó el potencial interpretativo de los sitios de interés y se determinó que la capacidad de carga está limitada por el manejo que se le viene dando a este escenario paisajístico. Por lo anterior, se recomienda un plan de manejo que vincule a los actores locales, utilizando la interpretación ambiental como herramienta que garantice la conservación de los recursos naturales y el desarrollo turístico sostenible.

  15. Mineral deposits of Central America, with a section on manganese deposits of Panama

    Science.gov (United States)

    Roberts, Ralph Jackson; Irving, Earl Montgomery; Simons, F.S.

    1957-01-01

    The mineral deposits of Central America were studied between 1942 and 1945, in cooperation with the United States Department of State and the Foreign Economic Administration. Emphasis was originally placed on the study of strategic-mineral deposits, especially of antimony, chromite, manganese, quartz, and mica, but deposits of other minerals that offered promise of significant future production were also studied. A brief appraisal of the base-metal deposits was made, and deposits of iron ore in Honduras and of lead and zinc ores in Guatemala were mapped. In addition, studies were made of the regional geology of some areas, data were collected from many sources, and a new map of the geology of Central America was compiled.

  16. Information pertinent to the migration of radionuclides in ground water at the Nevada Test Site. Part 1. Review and analysis of existing information

    International Nuclear Information System (INIS)

    Borg, I.Y.; Stone, R.; Levy, H.B.; Ramspott, L.D.

    1976-01-01

    A history of NTS is given, the geologic and hydrologic setting is described, and the amount of radioactivity deposited within and near the main aquifers is estimated. The conclusions include: information currently available is insufficient to state categorically that radioactivity will never be carried off the Nevada Test Site by ground water movement; nonetheless, such a migration at levels above the maximum permissible concentration to existing wells and springs is considered unlikely; if offsite migration occurs, it will probably be from the southwestern margins of Pahute Mesa, where there is only a small chance of contaminating existing public water supplies; tritium is the most mobile radionuclide and may be the only long-lived isotope of concern. Highest priority is assigned to measurement of tritium and other radionuclides in large water samples taken from nuclear chimneys that water has re-entered after an explosion; expansion of the existing groundwater monitoring program at NTS to include wells with a higher probability of intersecting flow of contaminated water; measurement of groundwater flow velocities and other associated hydrologic parameters. High priority is assigned to production of an inventory of radionuclides deposited near NTS borders, especially beneath Pahute Mesa; determination of amounts of radioactivity deposited directly into the Lower Carbonate Aquifer; a sensitivity analysis of the many parameters that enter into transport calculations; a study of the many unplugged holes that penetrate the Tuff Aquitard; testing of the assumption that radionuclides deposited in the unsaturated zone are isolated from the saturated zone because of limited precipitation and downward movement of moisture; and determination of distribution coefficients for NTS alluvium, carbonate, and rhyolitic rocks, which are lacking or poorly represented in the literature. Twelve other recommendations of lesser priority are also given

  17. Tandem solar cells deposited using hot-wire chemical vapor deposition

    NARCIS (Netherlands)

    Veen, M.K. van

    2003-01-01

    In this thesis, the application of the hot-wire chemical vapor deposition (HWCVD) technique for the deposition of silicon thin films is described. The HWCVD technique is based on the dissociation of silicon-containing gasses at the catalytic surface of a hot filament. Advantages of this technique

  18. In-situ CdS/CdTe Heterojuntions Deposited by Pulsed Laser Deposition

    KAUST Repository

    Avila-Avendano, Jesus

    2016-04-09

    In this paper pulsed laser deposition (PLD) methods are used to study p-n CdTe/CdS heterojunctions fabricated in-situ. In-situ film deposition allows higher quality p-n interfaces by minimizing spurious contamination from the atmosphere. Morphologic and structural analyses were carried for CdTe films deposited on various substrates and different deposition conditions. The electrical characteristics and performance of the resulting p-n heterojunctions were studied as function of substrate and post-deposition anneal temperature. In-situ growth results on diodes with a rectification factor of ~ 105, an ideality factor < 2, and a reverse saturation current ~ 10-8 A. The carrier concentration in the CdTe film was in the range of ~ 1015 cm-3, as measured by C-V methods. The possible impact of sulfur diffusion from the CdS into the CdTe film is also investigated using High Resolution Rutherford Back-Scattering.

  19. In-situ CdS/CdTe Heterojuntions Deposited by Pulsed Laser Deposition

    KAUST Repository

    Avila-Avendano, Jesus; Mejia, Israel; Alshareef, Husam N.; Guo, Zaibing; Young, Chadwin; Quevedo-Lopez, Manuel

    2016-01-01

    In this paper pulsed laser deposition (PLD) methods are used to study p-n CdTe/CdS heterojunctions fabricated in-situ. In-situ film deposition allows higher quality p-n interfaces by minimizing spurious contamination from the atmosphere. Morphologic and structural analyses were carried for CdTe films deposited on various substrates and different deposition conditions. The electrical characteristics and performance of the resulting p-n heterojunctions were studied as function of substrate and post-deposition anneal temperature. In-situ growth results on diodes with a rectification factor of ~ 105, an ideality factor < 2, and a reverse saturation current ~ 10-8 A. The carrier concentration in the CdTe film was in the range of ~ 1015 cm-3, as measured by C-V methods. The possible impact of sulfur diffusion from the CdS into the CdTe film is also investigated using High Resolution Rutherford Back-Scattering.

  20. Reactive polymer fused deposition manufacturing

    Science.gov (United States)

    Kunc, Vlastimil; Rios, Orlando; Love, Lonnie J.; Duty, Chad E.; Johs, Alexander

    2017-05-16

    Methods and compositions for additive manufacturing that include reactive or thermosetting polymers, such as urethanes and epoxies. The polymers are melted, partially cross-linked prior to the depositing, deposited to form a component object, solidified, and fully cross-linked. These polymers form networks of chemical bonds that span the deposited layers. Application of a directional electromagnetic field can be applied to aromatic polymers after deposition to align the polymers for improved bonding between the deposited layers.

  1. Deposition of InP-ON-Si Substrates for Monolithic Integration of Advanced Electronics

    Science.gov (United States)

    1991-04-19

    efficiency, 3 low-cost solar cells , optoelectronic IC’s and GaAs IC’s on large-area Si substrates. Although much work has been done, the performance of the...1. Mesa Diode Fabrication A small piece was cut from the edge of the InP/InP solar cell ---;fr .12-1) I back contact was protected by photoresist. On...1~~~~ A,,).’,**** LLS - .* .’ ~*Ii* En - in - C *- -**0:; iU.)~ ILI Y a.E - CU CU tnJn ~c~C"+ m 00 -~4 CD J - -4i - - Ln cI- C2- El4 wi -r Lf

  2. Arc-related porphyry molybdenum deposit model: Chapter D in Mineral deposit models for resource assessment

    Science.gov (United States)

    Taylor, Ryan D.; Hammarstrom, Jane M.; Piatak, Nadine M.; Seal, Robert R.

    2012-01-01

    This report provides a descriptive model for arc-related porphyry molybdenum deposits. Presented within are geological, geochemical, and mineralogical characteristics that differentiate this deposit type from porphyry copper and alkali-feldspar rhyolite-granite porphyry molybdenum deposits. The U.S. Geological Survey's effort to update existing mineral deposit models spurred this research, which is intended to supplement previously published models for this deposit type that help guide mineral-resource and mineral-environmental assessments.

  3. Low-pressure chemical vapor deposition as a tool for deposition of thin film battery materials

    NARCIS (Netherlands)

    Oudenhoven, J.F.M.; Dongen, van T.; Niessen, R.A.H.; Croon, de M.H.J.M.; Notten, P.H.L.

    2009-01-01

    Low Pressure Chemical Vapor Deposition was utilized for the deposition of LiCoO2 cathode materials for all-solid-state thin-film micro-batteries. To obtain insight in the deposition process, the most important process parameters were optimized for the deposition of crystalline electrode films on

  4. Quartz-pebble-conglomerate gold deposits: Chapter P in Mineral deposit models for resource assessment

    Science.gov (United States)

    Taylor, Ryan D.; Anderson, Eric D.

    2018-05-17

    Quartz-pebble-conglomerate gold deposits represent the largest repository of gold on Earth, largely due to the deposits of the Witwatersrand Basin, which account for nearly 40 percent of the total gold produced throughout Earth’s history. This deposit type has had a controversial history in regards to genetic models. However, most researchers conclude that they are paleoplacer deposits that have been modified by metamorphism and hydrothermal fluid flow subsequent to initial sedimentation.The deposits are found exclusively within fault-bounded depositional basins. The periphery of these basins commonly consists of granite-greenstone terranes, classic hosts for lode gold that source the detrital material infilling the basin. The gold reefs are typically located along unconformities or, less commonly, at the top of sedimentary beds. Large quartz pebbles and heavy-mineral concentrates are found associated with the gold. Deposits that formed prior to the Great Oxidation Event (circa 2.4 giga-annum [Ga]) contain pyrite, whereas younger deposits contain iron oxides. Uranium minerals and hydrocarbons are also notable features of some deposits.Much of the gold in these types of deposits forms crystalline features that are the product of local remobilization. However, some gold grains preserve textures that are undoubtedly of detrital origin. Other heavy minerals, such as pyrite, contain growth banding that is truncated along broken margins, which indicates that they were transported into place as opposed to forming by in situ growth in a hydrothermal setting.The ore tailings associated with these deposits commonly contain uranium-rich minerals and sulfides. Oxidation of the sulfides releases sulfuric acid and mobilizes various metals into the environment. The neutralizing potential of the tailings is minimal, since carbonate minerals are rare. The continuity of the tabular ore bodies, such as those of the Witwatersrand Basin, has allowed these mines to be the deepest in

  5. Urban acid deposition

    Energy Technology Data Exchange (ETDEWEB)

    Conlan, D.E.; Longhurst, J.W.S.; Gee, D.R.; Hare, S.E.

    1991-07-01

    In this document results from the Greater Manchester Acid Deposition Survey (GMADS), an urban precipitation chemistry network, for 1990 are presented. Full analytical methods are described along with the precision and accuracy of the methods used. The spatial variability of precipitation chemistry and deposition over this urban region was investigated using a network of twenty collectors. Concentrations of non marine sulphate, ammonium, calcium and hydrogen, and nitrogen dioxide gas concentrations all show significant spatial variability. The spatial variability of the deposition rates of non marine sulphate, nitrate, ammonium, hydrogen and calcium were significant. (Author).

  6. Post-depositional fracturing and subsidence of pumice flow deposits: Lascar Volcano, Chile.

    Science.gov (United States)

    Whelley, Patrick L; Jay, J; Calder, E S; Pritchard, M E; Cassidy, N J; Alcaraz, S; Pavez, A

    Unconsolidated pyroclastic flow deposits of the 1993 eruption of Lascar Volcano, Chile, have, with time, become increasingly dissected by a network of deeply penetrating fractures. The fracture network comprises orthogonal sets of decimeter-wide linear voids that form a pseudo-polygonal grid visible on the deposit surface. In this work, we combine shallow surface geophysical imaging tools with remote sensing observations and direct field measurements of the deposit to investigate these fractures and their underlying causal mechanisms. Based on ground penetrating radar images, the fractures are observed to have propagated to depths of up to 10 m. In addition, orbiting radar interferometry shows that deposit subsidence of up to 1 cm/year -1 occurred between 1993 and 1996 with continued subsidence occurring at a slower rate thereafter. In situ measurements show that 1 m below the surface, the 1993 deposits remain 5°C to 15°C hotter, 18 years after emplacement, than adjacent deposits. Based on the observed subsidence as well as estimated cooling rates, the fractures are inferred to be the combined result of deaeration, thermal contraction, and sedimentary compaction in the months to years following deposition. Significant environmental factors, including regional earthquakes in 1995 and 2007, accelerated settling at punctuated moments in time. The spatially variable fracture pattern relates to surface slope and lithofacies variations as well as substrate lithology. Similar fractures have been reported in other ignimbrites but are generally exposed only in cross section and are often attributed to formation by external forces. Here we suggest that such interpretations should be invoked with caution, and deformation including post-emplacement subsidence and fracturing of loosely packed ash-rich deposits in the months to years post-emplacement is a process inherent in the settling of pyroclastic material.

  7. Estimating Pesticide Exposure from Dietary Intake and Organic Food Choices: The Multi-Ethnic Study of Atherosclerosis (MESA)

    Science.gov (United States)

    Beresford, Shirley A.A.; Fenske, Richard A.; Fitzpatrick, Annette L.; Lu, Chensheng; Nettleton, Jennifer A.; Kaufman, Joel D.

    2015-01-01

    Background Organophosphate pesticide (OP) exposure to the U.S. population is dominated by dietary intake. The magnitude of exposure from diet depends partly on personal decisions such as which foods to eat and whether to choose organic food. Most studies of OP exposure rely on urinary biomarkers, which are limited by short half-lives and often lack specificity to parent compounds. A reliable means of estimating long-term dietary exposure to individual OPs is needed to assess the potential relationship with adverse health effects. Objectives We assessed long-term dietary exposure to 14 OPs among 4,466 participants in the Multi-Ethnic Study of Atherosclerosis, and examined the influence of organic produce consumption on this exposure. Methods Individual-level exposure was estimated by combining information on typical intake of specific food items with average OP residue levels on those items. In an analysis restricted to a subset of participants who reported rarely or never eating organic produce (“conventional consumers”), we assessed urinary dialkylphosphate (DAP) levels across tertiles of estimated exposure (n = 480). In a second analysis, we compared DAP levels across subgroups with differing self-reported organic produce consumption habits (n = 240). Results Among conventional consumers, increasing tertile of estimated dietary OP exposure was associated with higher DAP concentrations (p Fenske RA, Fitzpatrick AL, Lu C, Nettleton JA, Kaufman JD. 2015. Estimating pesticide exposure from dietary intake and organic food choices: the Multi-Ethnic Study of Atherosclerosis (MESA). Environ Health Perspect 123:475–483; http://dx.doi.org/10.1289/ehp.1408197 PMID:25650532

  8. Low-fluorine Stockwork Molybdenite Deposits

    Science.gov (United States)

    Ludington, Steve; Hammarstrom, Jane; Piatak, Nadine M.

    2009-01-01

    Low-fluorine stockwork molybdenite deposits are closely related to porphyry copper deposits, being similar in their tectonic setting (continental volcanic arc) and the petrology (calc-alkaline) of associated igneous rock types. They are mainly restricted to the Cordillera of western Canada and the northwest United States, and their distribution elsewhere in the world may be limited. The deposits consist of stockwork bodies of molybdenite-bearing quartz veinlets that are present in and around the upper parts of intermediate to felsic intrusions. The deposits are relatively low grade (0.05 to 0.2 percent Mo), but relatively large, commonly >50 million tons. The source plutons for these deposits range from granodiorite to granite in composition; the deposits primarily form in continental margin subduction-related magmatic arcs, often concurrent with formation of nearby porphyry copper deposits. Oxidation of pyrite in unmined deposits or in tailings and waste rock during weathering can lead to development of acid-rock drainage and limonite-rich gossans. Waters associated with low-fluorine stockwork molybdenite deposits tend to be nearly neutral in pH; variable in concentrations of molybdenum (10,000 ug/L); below regulatory guidelines for copper, iron, lead, zinc, and mercury; and locally may exceed guidelines for arsenic, cadmium, and selenium.

  9. Development and evaluation of a long-term deposit probe for on-line monitoring of deposit growth

    Energy Technology Data Exchange (ETDEWEB)

    Brink, Anders; Lauren, Tor; Yrjas, Patrik; Hupa, Mikko [Process Chemistry Centre, Aabo Akademi University, Biskopsgatan 8, FI-20540 Turku (Finland); Friesenbichler, Joachim [Institute for Resource Efficient and Sustainable Systems, Technical University Graz Inffeldg. 21b, A-8010 Graz (Austria)

    2007-12-15

    A newly designed air-cooled probe for on-line monitoring of deposition growth has been tested in a boiler firing three woody fuels. Thermocouples are mounted on both sides of the tube wall enabling measurements of the heat flux through the probe wall. Knowing the heat flux through the probe wall, it is possible to measure the additional heat transfer resistance caused by the deposit and to estimate the properties of the deposit. Calculating the deposit thickness using the collected temperature data indicated the thinnest deposit when wood was fired, followed by bark and waste wood. The calculated deposit thickness was larger than those found when analysing the deposit thickness after the probe had been removed. Nevertheless, the ranking of fuels by deposit build-up rate was the same. (author)

  10. Dry deposition on urban surfaces

    International Nuclear Information System (INIS)

    Roed, J.

    1985-01-01

    In order to facilitate developing a model for deposition in urban areas, beryllium-7, created by cosmic radiation and fall-out cesium-137, have been used as tracers in measurements designed to find the dry deposition velocity on building surfaces. A literature review has revealed that very little work has been done on deposition in urban areas; therefore, a major effort on meausring the deposition parameter is needed to construct reliable models in this field. Deposition velocities in the range from 0.001-0.04 cm/s have been found. (author)

  11. A special issue devoted to gold deposits in northern Nevada: Part 2. Carlin-type Deposits

    Science.gov (United States)

    Hofstra, Albert H.; John, David A.; Theodore, Ted G.

    2003-01-01

    This is the second of two special issues of Economic Geology devoted to gold deposits in northern Nevada. Readers interested in a general overview of these deposits, their economic significance, their context within the tectonic evolution of the region, and synoptic references on each gold deposit type are directed to the preface of the first special issue (John et al., 2003). Volume 98, issue 2, contains five papers that address regional aspects important to the genesis of gold deposits in northern Nevada and five papers that present detailed studies of epithermal deposits and districts. All of the regional papers are pertinent to Carlin-type gold deposits, because they address the age of mineralization (Arehart et al., 2003), origin and evolutionary history of the northwest-striking mineral belts that localize many deposits (Grauch et al., 2003), nature of the middle and lower crust below these mineral belts (Howard, 2003), district- to deposit-scale stream sediment and lithogeochemical anomalies (Theodore et al., 2003), and stratigraphy and structure of a district located along a northeast-striking lineament (Peters et al., 2003).

  12. Deposits of the Peruvian Pisco Formation compared to layered deposits on Mars

    Science.gov (United States)

    Sowe, M.; Bishop, J. L.; Gross, C.; Walter, S.

    2013-09-01

    Deposits of the Peruvian Pisco Formation are morphologically similar to the mounds of Juventae Chasma at the equatorial region on Mars (Fig. 1). By analyzing these deposits, we hope to gain information about the environmental conditions that prevailed during sediment deposition and erosion, hence conditions that might be applicable to the Martian layered and hydrated deposits. Mariner 9 data of the Martian mid-latitudes have already shown evidence of the wind-sculptured landforms that display the powerful prevailing eolian regime [1]. In addition, [2] reported on similarities between Martian erosional landforms and those of the rainless coastal desert of central Peru from the Paracas peninsula to the Rio Ica. As indicated by similar erosional patterns, hyper-arid conditions and unidirectional winds must have dominated at least after deposition of the sediments, which are intermixed volcaniclastic materials and evaporate minerals at both locations. Likewise, variations in composition are displayed by alternating layers of different competence. The Pisco formation bears yardangs on siltstones, sandstones and clays with volcaniclastic admixtures [3] whereas the presence of sulphate minerals and the omnipresent mafic mineralogy has been reported for the layered mounds of Juventae Chasma equally [4]. Likewise, a volcanic airfall deposition and lacustrine formation have been proposed for the sulphate-rich deposits of Juventae Chasma [5,6]. In order to find out about potential spectral similarities, we performed a detailed spectral analysis of the surface by using LANDSAT and Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) VNIR/ SWIR data (visible to near-infrared and shortwave infrared region).

  13. NURE uranium deposit model studies

    International Nuclear Information System (INIS)

    Crew, M.E.

    1981-01-01

    The National Uranium Resource Evaluation (NURE) Program has sponsored uranium deposit model studies by Bendix Field Engineering Corporation (Bendix), the US Geological Survey (USGS), and numerous subcontractors. This paper deals only with models from the following six reports prepared by Samuel S. Adams and Associates: GJBX-1(81) - Geology and Recognition Criteria for Roll-Type Uranium Deposits in Continental Sandstones; GJBX-2(81) - Geology and Recognition Criteria for Uraniferous Humate Deposits, Grants Uranium Region, New Mexico; GJBX-3(81) - Geology and Recognition Criteria for Uranium Deposits of the Quartz-Pebble Conglomerate Type; GJBX-4(81) - Geology and Recognition Criteria for Sandstone Uranium Deposits in Mixed Fluvial-Shallow Marine Sedimentary Sequences, South Texas; GJBX-5(81) - Geology and Recognition Criteria for Veinlike Uranium Deposits of the Lower to Middle Proterozoic Unconformity and Strata-Related Types; GJBX-6(81) - Geology and Recognition Criteria for Sandstone Uranium Deposits of the Salt Wash Type, Colorado Plateau Province. A unique feature of these models is the development of recognition criteria in a systematic fashion, with a method for quantifying the various items. The recognition-criteria networks are used in this paper to illustrate the various types of deposits

  14. Efecto de los hidrocarburos en suelos arenosos de la mesa de Guanipa-Venezuela y propuesta de tratamientos alternativos para la recuperación de suelos contaminados con gasoil y aceites dieléctricos con BPC

    OpenAIRE

    Gomez Oviedo, Adriana Sugey

    2012-01-01

    Esta investigación se ha dividido en tres etapas, primero se analizó el efecto de los hidrocarburos (crudos liviano, extrapesado y gasoil) a razón de dosis bajas 2 y 4 % p/p, y altas 30, 40 y 50 % p/p en un suelo arenoso de la Mesa de Guanipa en Venezuela, empleando técnicas analíticas e instrumentales para su caracterización, también se determinó el efecto que tienen estos contaminantes sobre la actividad biológica del suelo durante 29 días de incubación. La segunda fase consistió en aplicar...

  15. Vapor deposition of large area NpO2 and UO2 deposits

    International Nuclear Information System (INIS)

    Adair, H.L.; Gibson, J.R.; Kobisk, E.H.; Dailey, J.M.

    1976-01-01

    Deposition of NpO 2 and UO 2 thin films over an area of 7.5 to 10 cm diam has become a routine operation in preparation of fission chamber plates. Vacuum evaporation or electroplating has been used for this purpose. The ''paint brush'' technique has been used as well; however, uniformity requirements normally eliminate this procedure. Vapor deposition in vacuum appears to be the most suitable technique for preparing NpO 2 and UO 2 deposits of >200 cm 2 . This paper describes the procedures used in preparing uniform large area deposits of NpO 2 (approximately 300 cm 2 ) and UO 2 (approximately 2000 cm 2 ) by vacuum evaporation using electron bombardment heating and several substrate motion and heating methods to achieve uniformity and adhesion

  16. Precambrian uranium deposits as a possible source of uranium for the European Variscan deposits

    International Nuclear Information System (INIS)

    Mineeva, I.G.; Klochkov, A.S.

    2002-01-01

    The Precambrian uranium deposits have been studied on the territory of Baltic and Ukrainian shields. The primary Early Proterozoic complex Au-U deposits originated in granite-greenstone belts as a result of their evolution during continental earth crust formation by prolonged rift genesis. The greenstone belts are clues for revealing ancient protoriftogenic structures. The general regularities of uranium deposition on Precambrian shields are also traceable in Variscan uranium deposits from the Bohemian massif. The Variscan period of uranium ore formation is connected with a polychronous rejuvenation of ancient riftogenous systems and relatively younger processes of oil and gas formation leading to the repeated mobilization of U from destroyed Proterozoic and Riphean uranium deposits. (author)

  17. Uranium deposits in granitic rocks

    International Nuclear Information System (INIS)

    Nishimori, R.K.; Ragland, P.C.; Rogers, J.J.W.; Greenberg, J.K.

    1977-01-01

    This report is a review of published data bearing on the geology and origin of uranium deposits in granitic, pegmatitic and migmatitic rocks with the aim of assisting in the development of predictive criteria for the search for similar deposits in the U.S. Efforts were concentrated on the so-called ''porphyry'' uranium deposits. Two types of uranium deposits are primarily considered: deposits in pegmatites and alaskites in gneiss terrains, and disseminations of uranium in high-level granites. In Chapter 1 of this report, the general data on the distribution of uranium in igneous and metamorphic rocks are reviewed. Chapter 2 contains some comments on the classification of uranium deposits associated with igneous rocks and a summary of the main features of the geology of uranium deposits in granites. General concepts of the behavior of uranium in granites during crustal evolution are reviewed in Chapter 3. Also included is a discussion of the relationship of uranium mineralization in granites to the general evolution of mobile belts, plus the influence of magmatic and post-magmatic processes on the distribution of uranium in igneous rocks and related ore deposits. Chapter 4 relates the results of experimental studies on the crystallization of granites to some of the geologic features of uranium deposits in pegmatites and alaskites in high-grade metamorphic terrains. Potential or favorable areas for igneous uranium deposits in the U.S.A. are delineated in Chapter 5. Data on the geology of specific uranium deposits in granitic rocks are contained in Appendix 1. A compilation of igneous rock formations containing greater than 10 ppM uranium is included in Appendix 2. Appendix 3 is a report on the results of a visit to the Roessing area. Appendix 4 is a report on a field excursion to eastern Canada

  18. Enhanced nitrogen deposition over China

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Xuejun; Zhang, Ying; Han, Wenxuan; Tang, Aohan; Shen, Jianlin; Cui, Zhenling; Christie, Peter; Zhang, Fusuo [College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193 (China); Vitousek, Peter [Department of Biology, Stanford University, Stanford, California 94305 (United States); Erisman, Jan Willem [VU University Amsterdam, 1081 HV Amsterdam (Netherlands); Goulding, Keith [The Sustainable Soils and Grassland Systems Department, Rothamsted Research, Harpenden AL5 2JQ (United Kingdom); Fangmeier, Andreas [Institute of Landscape and Plant Ecology, University of Hohenheim, 70593 Stuttgart (Germany)

    2013-02-28

    China is experiencing intense air pollution caused in large part by anthropogenic emissions of reactive nitrogen. These emissions result in the deposition of atmospheric nitrogen (N) in terrestrial and aquatic ecosystems, with implications for human and ecosystem health, greenhouse gas balances and biological diversity. However, information on the magnitude and environmental impact of N deposition in China is limited. Here we use nationwide data sets on bulk N deposition, plant foliar N and crop N uptake (from long-term unfertilized soils) to evaluate N deposition dynamics and their effect on ecosystems across China between 1980 and 2010. We find that the average annual bulk deposition of N increased by approximately 8 kilograms of nitrogen per hectare (P < 0.001) between the 1980s (13.2 kilograms of nitrogen per hectare) and the 2000s (21.1 kilograms of nitrogen per hectare). Nitrogen deposition rates in the industrialized and agriculturally intensified regions of China are as high as the peak levels of deposition in northwestern Europe in the 1980s, before the introduction of mitigation measures. Nitrogen from ammonium (NH4+) is the dominant form of N in bulk deposition, but the rate of increase is largest for deposition of N from nitrate (NO3-), in agreement with decreased ratios of NH3 to NOx emissions since 1980. We also find that the impact of N deposition on Chinese ecosystems includes significantly increased plant foliar N concentrations in natural and semi-natural (that is, non-agricultural) ecosystems and increased crop N uptake from long-term-unfertilized croplands. China and other economies are facing a continuing challenge to reduce emissions of reactive nitrogen, N deposition and their negative effects on human health and the environment.

  19. Breakthrough to Non-Vacuum Deposition of Single-Crystal, Ultra-Thin, Homogeneous Nanoparticle Layers: A Better Alternative to Chemical Bath Deposition and Atomic Layer Deposition

    Directory of Open Access Journals (Sweden)

    Yu-Kuang Liao

    2017-04-01

    Full Text Available Most thin-film techniques require a multiple vacuum process, and cannot produce high-coverage continuous thin films with the thickness of a few nanometers on rough surfaces. We present a new ”paradigm shift” non-vacuum process to deposit high-quality, ultra-thin, single-crystal layers of coalesced sulfide nanoparticles (NPs with controllable thickness down to a few nanometers, based on thermal decomposition. This provides high-coverage, homogeneous thickness, and large-area deposition over a rough surface, with little material loss or liquid chemical waste, and deposition rates of 10 nm/min. This technique can potentially replace conventional thin-film deposition methods, such as atomic layer deposition (ALD and chemical bath deposition (CBD as used by the Cu(In,GaSe2 (CIGS thin-film solar cell industry for decades. We demonstrate 32% improvement of CIGS thin-film solar cell efficiency in comparison to reference devices prepared by conventional CBD deposition method by depositing the ZnS NPs buffer layer using the new process. The new ZnS NPs layer allows reduction of an intrinsic ZnO layer, which can lead to severe shunt leakage in case of a CBD buffer layer. This leads to a 65% relative efficiency increase.

  20. Dual Nitrate Isotopes in Dry Deposition: Utility for Partitioning Nox Source Contributions to Landscape Nitrogen Deposition

    Science.gov (United States)

    Dry deposition is a major component of total nitrogen deposition and thus an important source of bioavailable nitrogen to ecosystems. However, relative to wet deposition, less is known regarding the sources and spatial variability of dry deposition. This is in part due to diffi...

  1. CTS and CZTS for solar cells made by pulsed laser deposition and pulsed electron deposition

    DEFF Research Database (Denmark)

    Ettlinger, Rebecca Bolt

    This thesis concerns the deposition of thin films for solar cells using pulsed laser deposition (PLD) and pulsed electron deposition (PED). The aim was to deposit copper tin sulfide (CTS) and zinc sulfide (ZnS) by pulsed laser deposition to learn about these materials in relation to copper zinc tin...... time. We compared the results of CZTS deposition by PLD at DTU in Denmark to CZTS made by PED at IMEM-CNR, where CIGS solar cells have successfully been fabricated at very low processing temperatures. The main results of this work were as follows: Monoclinic-phase CTS films were made by pulsed laser...... deposition followed by high temperature annealing. The films were used to understand the double band gap that we and other groups observed in the material. The Cu-content of the CTS films varied depending on the laser fluence (the laser energy per pulse and per area). The material transfer from...

  2. Laboratory Deposition Apparatus to Study the Effects of Wax Deposition on Pipe Magnetic Field Leakage Signals

    Directory of Open Access Journals (Sweden)

    Karim Mohd Fauzi Abd

    2014-07-01

    Full Text Available Accurate technique for wax deposition detection and severity measurement on cold pipe wall is important for pipeline cleaning program. Usually these techniques are validated by conventional techniques on laboratory scale wax deposition flow loop. However conventional techniques inherent limitations and it is difficult to reproduce a predetermine wax deposit profile and hardness at designated location in flow loop. An alternative wax deposition system which integrates modified pour casting method and cold finger method is presented. This system is suitable to reproduce high volume of medium hard wax deposit in pipe with better control of wax deposit profile and hardness.

  3. The influences of target properties and deposition times on pulsed laser deposited hydroxyapatite films

    International Nuclear Information System (INIS)

    Bao Quanhe; Chen Chuanzhong; Wang Diangang; Liu Junming

    2008-01-01

    Hydroxyapatite films were produced by pulsed laser deposition from three kinds of hydroxyapatite targets and with different deposition times. A JXA-8800R electron probe microanalyzer (EPMA) with a Link ISIS300 energy spectrum analyzer was used to give the secondary electron image (SE) and determine the element composition of the films. The phases of thin film were analyzed by a D/max-γc X-ray diffractometer (XRD). The Fourier-transform infrared spectroscopy (FT-IR) was used to characterize the hydroxyl, phosphate and other functional groups. The results show that deposited films were amorphous which mainly composed of droplet-like particles and vibration of PO 4 3- groups. With the target sintering temperature deposition times increasing, the density of droplets is decreased. While with deposition times increasing, the density of droplets is increased. With the target sintering temperature and deposition time increasing, the ratio of Ca/P is increasing and higher than that of theoretical value of HA

  4. Discovery of potassium salts deposits in colombia

    International Nuclear Information System (INIS)

    Gonzalez Oviedo Leopoldo; Espinosa Baquero Armando

    2012-01-01

    The first potassium salts ores found in Colombia are presented and described; they are located in the Santander province, in La Mesa de los Santos area, between Los Santos village and the rio Chicamocha Canyon. From a geological point of view, the mineralization is associated to the sediments of the Paja Formation, Early Cretaceous in age, and is located near the base of the formation. In the study area the main structure is the Villanueva syncline which involves, from bottom to top, Los Santos, Rosablanca, Paja, Tablazo and Simiti formations.The mineralization consists of small veins where the main mineral is singenite (K 2 Ca[SO4] 2- H 2 O) with small amounts of carbonates and accidental minerals. In the host rock, minerals like langbeinite (K 2 Mg 2 [SO4] 3) andrinneite (K 3 Na[Fe,Cl] 6) are present; they show that the rock was formed in an evaporitic environment and that detailed studies of that sequence may lead to the discovery of other mineralizations of economic interest.

  5. Advanced deposition model for thermal activated chemical vapor deposition

    Science.gov (United States)

    Cai, Dang

    Thermal Activated Chemical Vapor Deposition (TACVD) is defined as the formation of a stable solid product on a heated substrate surface from chemical reactions and/or dissociation of gaseous reactants in an activated environment. It has become an essential process for producing solid film, bulk material, coating, fibers, powders and monolithic components. Global market of CVD products has reached multi billions dollars for each year. In the recent years CVD process has been extensively used to manufacture semiconductors and other electronic components such as polysilicon, AlN and GaN. Extensive research effort has been directed to improve deposition quality and throughput. To obtain fast and high quality deposition, operational conditions such as temperature, pressure, fluid velocity and species concentration and geometry conditions such as source-substrate distance need to be well controlled in a CVD system. This thesis will focus on design of CVD processes through understanding the transport and reaction phenomena in the growth reactor. Since the in situ monitor is almost impossible for CVD reactor, many industrial resources have been expended to determine the optimum design by semi-empirical methods and trial-and-error procedures. This approach has allowed the achievement of improvements in the deposition sequence, but begins to show its limitations, as this method cannot always fulfill the more and more stringent specifications of the industry. To resolve this problem, numerical simulation is widely used in studying the growth techniques. The difficulty of numerical simulation of TACVD crystal growth process lies in the simulation of gas phase and surface reactions, especially the latter one, due to the fact that very limited kinetic information is available in the open literature. In this thesis, an advanced deposition model was developed to study the multi-component fluid flow, homogeneous gas phase reactions inside the reactor chamber, heterogeneous surface

  6. Effect of post-deposition implantation and annealing on the properties of PECVD deposited silicon nitride films

    International Nuclear Information System (INIS)

    Shams, Q.A.

    1988-01-01

    Recently it has been shown that memory-quality silicon nitride can be deposited using plasma enhanced chemical vapor deposition (PECVD). Nitrogen implantation and post-deposition annealing resulted in improved memory properties of MNOS devices. The primary objective of the work described here is the continuation of the above work. Silicon nitride films were deposited using argon as the carrier gas and evaluated in terms of memory performance as the charge-trapping layer in the metal-nitride-oxide-silicon (MNOS) capacitor structure. The bonding structure of PECVD silicon nitride was modified by annealing in different ambients at temperatures higher than the deposition temperature. Post-deposition ion implantation was used to introduce argon into the films in an attempt to influence the transfer, trapping, and emission of charge during write/erase exercising of the MNOS devices. Results show that the memory performance of PECVD silicon nitride is sensitive to the deposition parameters and post-deposition processing

  7. Breaking Through the Multi-Mesa-Channel Width Limited of Normally Off GaN HEMTs Through Modulation of the Via-Hole-Length.

    Science.gov (United States)

    Chien, Cheng-Yen; Wu, Wen-Hsin; You, Yao-Hong; Lin, Jun-Huei; Lee, Chia-Yu; Hsu, Wen-Ching; Kuan, Chieh-Hsiung; Lin, Ray-Ming

    2017-12-01

    We present new normally off GaN high-electron-mobility transistors (HEMTs) that overcome the typical limitations in multi-mesa-channel (MMC) width through modulation of the via-hole-length to regulate the charge neutrality screen effect. We have prepared enhancement-mode (E-mode) GaN HEMTs having widths of up to 300 nm, based on an enhanced surface pinning effect. E-mode GaN HEMTs having MMC structures and widths as well as via-hole-lengths of 100 nm/2 μm and 300 nm/6 μm, respectively, exhibited positive threshold voltages (V th ) of 0.79 and 0.46 V, respectively. The on-resistances of the MMC and via-hole-length structures were lower than those of typical tri-gate nanoribbon GaN HEMTs. In addition, the devices not only achieved the E-mode but also improved the power performance of the GaN HEMTs and effectively mitigated the device thermal effect. We controlled the via-hole-length sidewall surface pinning effect to obtain the E-mode GaN HEMTs. Our findings suggest that via-hole-length normally off GaN HEMTs have great potential for use in next-generation power electronics.

  8. Reaction kinetics of metal deposition via surface limited red-ox replacement of underpotentially deposited metal monolayers

    International Nuclear Information System (INIS)

    Gokcen, Dincer; Bae, Sang-Eun; Brankovic, Stanko R.

    2011-01-01

    The study of the kinetics of metal deposition via surface limited red-ox replacement of underpotentially deposited metal monolayers is presented. The model system was Pt submonolayer deposition on Au(1 1 1) via red-ox replacement of Pb and Cu UPD monolayers on Au(1 1 1). The kinetics of a single replacement reaction was studied using the formalism of the comprehensive analytical model developed to fit the open circuit potential transients from deposition experiments. The practical reaction kinetics parameters like reaction half life, reaction order and reaction rate constant are determined and discussed with their relevance to design and control of deposition experiments. The effects of transport limitation and the role of the anions/electrolyte on deposition kinetics are investigated and their significance to design of effective deposition process is discussed.

  9. Thermal plasma chemical vapor deposition

    International Nuclear Information System (INIS)

    Heberlein, J.; Pfender, E.

    1993-01-01

    Thermal plasmas, with temperatures up to and even exceeding 10 4 K, are capable of producing high density vapor phase precursors for the deposition of relatively thick films. Although this technology is still in its infancy, it will fill the void between the relatively slow deposition processes such as physical vapor deposition and the high rate thermal spray deposition processes. In this chapter, the present state-of-the-art of this field is reviewed with emphasis on the various types of reactors proposed for this emerging technology. Only applications which attracted particular attention, namely diamond and high T c superconducting film deposition, are discussed in greater detail. (orig.)

  10. Gemstone deposits of Serbia

    Directory of Open Access Journals (Sweden)

    Miladinović Zoran

    2016-06-01

    Full Text Available Gemstone minerals in Serbia have never been regarded as an interesting and significant resource. Nevertheless, more than 150 deposits and occurrences have been recorded and some of them preliminarily explored in the last 50 years. The majority of deposits and occurrences are located within the Serbo-Macedonian metallogenic province and the most significant metallogenic units at the existing level of knowledge are the Fruska Gora ore district, Cer ore district, Sumadija metallogenic zone, Kopaonik metallogenic zone and Lece-Halkidiki metallogenic zone. The most important genetic type of deposits is hydrothermal, particularly in case of serpentinite/peridotite as host/parent rock. Placer deposits are also economically important. The dominant gemstones are silica minerals: chalcedony (Chrysoprase, carnelian, bluish chalcedony etc., jasper (picture, landscape, red etc., common opal (dendritic, green, milky white etc., silica masses (undivided, and quartz (rock crystal, amethyst etc.. Beside silica minerals significant gemstones in Serbia include also beryl (aquamarine, garnet (almandine and pyrope, tourmaline, fluorite, rhodochrosite, carbonate-silica breccia, carbonate-silica onyx, silicified wood, howlite, serpentinite, marble onyx, and kyanite. This paper aims to present an overview of Serbian gemstone deposits and occurrences and their position based on a simplified gemstone metallogenic map of Serbia, as well as genetic-industrial classification of gemstone deposits and gemstone varieties.

  11. Uranium deposits in Africa

    International Nuclear Information System (INIS)

    Wilpolt, R.H.; Simov, S.D.

    1979-01-01

    Africa is not only known for its spectacular diamond, gold, copper, chromium, platinum and phosphorus deposits but also for its uranium deposits. At least two uranium provinces can be distinguished - the southern, with the equatorial sub-province; and the south Saharan province. Uranium deposits are distributed either in cratons or in mobile belts, the first of sandstone and quartz-pebble conglomerate type, while those located in mobile belts are predominantly of vein and similar (disseminated) type. Uranium deposits occur within Precambrian rocks or in younger platform sediments, but close to the exposed Precambrian basement. The Proterozoic host rocks consist of sediments, metamorphics or granitoids. In contrast to Phanerozoic continental uranium-bearing sediments, those in the Precambrian are in marginal marine facies but they do contain organic material. The geology of Africa is briefly reviewed with the emphasis on those features which might control the distribution of uranium. The evolution of the African Platform is considered as a progressive reduction of its craton area which has been affected by three major Precambrian tectonic events. A short survey on the geology of known uranium deposits is made. However, some deposits and occurrences for which little published material is available are treated in more detail. (author)

  12. Gemstone deposits of Serbia

    Science.gov (United States)

    Miladinović, Zoran; Simić, Vladimir; Jelenković, Rade; Ilić, Miloje

    2016-06-01

    Gemstone minerals in Serbia have never been regarded as an interesting and significant resource. Nevertheless, more than 150 deposits and occurrences have been recorded and some of them preliminarily explored in the last 50 years. The majority of deposits and occurrences are located within the Serbo-Macedonian metallogenic province and the most significant metallogenic units at the existing level of knowledge are the Fruska Gora ore district, Cer ore district, Sumadija metallogenic zone, Kopaonik metallogenic zone and Lece-Halkidiki metallogenic zone. The most important genetic type of deposits is hydrothermal, particularly in case of serpentinite/peridotite as host/parent rock. Placer deposits are also economically important. The dominant gemstones are silica minerals: chalcedony (Chrysoprase, carnelian, bluish chalcedony etc.), jasper (picture, landscape, red etc.), common opal (dendritic, green, milky white etc.), silica masses (undivided), and quartz (rock crystal, amethyst etc.). Beside silica minerals significant gemstones in Serbia include also beryl (aquamarine), garnet (almandine and pyrope), tourmaline, fluorite, rhodochrosite, carbonate-silica breccia, carbonate-silica onyx, silicified wood, howlite, serpentinite, marble onyx, and kyanite. This paper aims to present an overview of Serbian gemstone deposits and occurrences and their position based on a simplified gemstone metallogenic map of Serbia, as well as genetic-industrial classification of gemstone deposits and gemstone varieties.

  13. Experimental measurements of the thermal conductivity of ash deposits: Part 2. Effects of sintering and deposit microstructure

    Energy Technology Data Exchange (ETDEWEB)

    A. L. Robinson; S. G. Buckley; N. Yang; L. L. Baxter

    2000-04-01

    The authors report results from an experimental study that examines the influence of sintering and microstructure on ash deposit thermal conductivity. The measurements are made using a technique developed to make in situ, time-resolved measurements of the effective thermal conductivity of ash deposits formed under conditions that closely replicate those found in the convective pass of a commercial boiler. The technique is designed to minimize the disturbance of the natural deposit microstructure. The initial stages of sintering and densification are accompanied by an increase in deposit thermal conductivity. Subsequent sintering continues to densify the deposit, but has little effect on deposit thermal conductivity. SEM analyses indicates that sintering creates a layered deposit structure with a relatively unsintered innermost layer. They hypothesize that this unsintered layer largely determines the overall deposit thermal conductivity. A theoretical model that treats a deposit as a two-layered material predicts the observed trends in thermal conductivity.

  14. Isolation and Selection of Epiphytic Yeast for Biocontrol of Botrytis cinerea Pers. on Table Grapes Aislación y Selección de Levaduras Epífitas para el Biocontrol de Botrytis cinerea Pers. en Uva de Mesa

    Directory of Open Access Journals (Sweden)

    Marisol Vargas

    2012-09-01

    Full Text Available Botrytis cinerea Pers., the causal agent of gray mold, infects more than 200 plant species. This pathogen has traditionally been controlled by fungicides. However, with the increasing demand for pesticide-free foods new control strategies are needed. The objective of this study was to isolate and select grapevine (Vitis vinifera L. epiphytic yeasts for the biocontrol of B. cinerea in table grapes. Of the total isolated yeasts (n = 256, 32 exhibited mycelial growth inhibition in dual cultures with a halo > 4 mm, and eight of these isolates inhibited > 90% of conidial germination. When evaluating increasing concentrations on conidial germination inhibition, a dose-dependent response was observed with EC90 values from 0.45 x 10(5 to 0.22 x 10(8 cells mL-1. The antagonistic activity of six yeasts against B. cinerea in table grape berries 'Flame Seedless' increased as the yeast colonization time increased from 1 to 24 h on the berries, resulting in a higher biocontrol activity on B. cinerea. These results show the effectiveness of grapevine epiphytic yeasts as biocontrol agents of B. cinerea on table grapes.Botrytis cinerea Pers., agente causal de la pudrición gris, infecta a más de 200 especies vegetales. Tradicionalmente, este patógeno ha sido controlado con fungicidas; sin embargo, la creciente demanda de alimentos libres de pesticidas hace necesario el uso de nuevas estrategias de control. El objetivo de este estudio fue aislar y seleccionar levaduras epífitas de vid (Vitis vinifera L. para el biocontrol de B. cinerea en uva de mesa. Del total de levaduras aisladas (n = 256, 32 presentaron inhibición del crecimiento micelial, en cultivos duales, con un halo > 4 mm y ocho de estos aislamientos inhibieron la germinación de conidias > 90%. Al evaluar concentraciones crecientes de levaduras sobre la inhibición de la germinación de conidias, se observó una respuesta dosis-dependiente, con valores de CE90 de 0,45 x 10(5 a 0,22 x 10(8 c

  15. To what extent can intracrater layered deposits that lack clear sedimentary textures be used to infer depositional environments?

    Science.gov (United States)

    Cadieux, Sarah B.; Kah, Linda C.

    2015-03-01

    Craters within Arabia Terra, Mars, contain hundreds of meters of layered strata showing systematic alternation between slope- and cliff-forming units, suggesting either rhythmic deposition of distinct lithologies or similar lithologies that experienced differential cementation. On Earth, rhythmically deposited strata can be examined in terms of stratal packaging, wherein the interplay of tectonics, sediment deposition, and base level (i.e., the position above which sediment accumulation is expected to be temporary) result in changes in the amount of space available for sediment accumulation. These predictable patterns of sediment deposition can be used to infer changes in basin accommodation regardless of the mechanism of deposition (e.g. fluvial, lacustrine, or aeolian). Here, we analyze sedimentary deposits from three craters (Becquerel Crater, Danielson Crater, Crater A) in Arabia Terra. Each crater contains layered deposits that are clearly observed in orbital images. Although orbital images are insufficient to specifically determine the origin of sedimentary deposits, depositional couplets can be interpreted in terms of potential accommodation space available for deposition, and changes in the distribution of couplet thickness through stratigraphy can be interpreted in terms of changing base level and the production of new accommodation space. Differences in stratal packaging in these three craters suggest varying relationships between sedimentary influx, sedimentary base level, and concomitant changes in accommodation space. Previous groundwater upwelling models hypothesize that layered sedimentary deposits were deposited under warm climate conditions of early Mars. Here, we use observed stacking patterns to propose a model for deposition under cold climate conditions, wherein episodic melting of ground ice could raise local base level, stabilize sediment deposition, and result in differential cementation of accumulated strata. Such analysis demonstrates that

  16. Seasonal atmospheric deposition variations of polychlorinated biphenyls (PCBs) and comparison of some deposition sampling techniques.

    Science.gov (United States)

    Birgül, Askın; Tasdemir, Yücel

    2011-03-01

    Ambient air and bulk deposition samples were collected between June 2008 and June 2009. Eighty-three polychlorinated biphenyl (PCB) congeners were targeted in the samples. The average gas and particle PCB concentrations were found as 393 ± 278 and 70 ± 102 pg/m(3), respectively, and 85% of the atmospheric PCBs were in the gas phase. Bulk deposition samples were collected by using a sampler made of stainless steel. The average PCB bulk deposition flux value was determined as 6,020 ± 4,350 pg/m(2) day. The seasonal bulk deposition fluxes were not statistically different from each other, but the summer flux had higher values. Flux values differed depending on the precipitation levels. The average flux value in the rainy periods was 7,480 ± 4,080 pg/m(2) day while the average flux value in dry periods was 5,550 ± 4,420 pg/m(2) day. The obtained deposition values were lower than the reported values given for the urban and industrialized areas, yet close to the ones for the rural sites. The reported deposition values were also influenced by the type of the instruments used. The average dry deposition and total deposition velocity values calculated based on deposition and concentration values were found as 0.23 ± 0.21 and 0.13 ± 0.13 cm/s, respectively.

  17. Geochronology of the Thompson Creek Mo Deposit: Evidence for the Formation of Arc-related Mo Deposits

    Science.gov (United States)

    Lawrence, C. D.; Coleman, D. S.; Stein, H. J.

    2016-12-01

    The Thompson Creek Mo deposit in central ID, has been categorized as an arc-related Mo deposit due to the location, grade of Mo, and relative lack of enrichments in F, Rb, and Nb, compared to the Climax-type Mo deposits. Geochronology from this arc-related deposit provides an opportunity to compare and contrast magmatism, and mineralization to that in Climax-type deposits. Distinct pulses of magmatism were required to form the Thompson Creek Mo deposit, which is consistent with recent geochronology from Climax-type deposits. Molybdenite Re-Os geochronology from five veins requires at least three pulses of magmatism and mineralization between 89.39 +/- 0.37 and 88.47 +/- 0.16 Ma. Zircon U-Pb ages from these mineralized samples overlap with molybdenite mineralization, but show a much wider range (91.01 +/- 0.37 to 87.27 +/- 0.69). Previous work from Climax-type Mo deposits suggest a correlation between a super eruption, and the subsequent rapid (<1 Ma) onset, and completion of Mo mineralizing intrusions. The longer life (3-4 Ma) for the Thompson Creek Mo deposit suggests that the mineralizing intrusions for arc-related Mo deposits may not need to have as high [Mo] as the Climax-type deposits. This study also finds a shift in the source of magmatism from the pre- to syn-mineralizing intrusions. Zircons from pre-mineralizing intrusions have much higher (15-60 pg) concentrations of radiogenic Pb than zircons from mineralized intrusions, which all have less than 15 pg, though whole rock [U] are similar.

  18. Surficial uranium deposits: summary and conclusions

    International Nuclear Information System (INIS)

    Otton, J.K.

    1984-01-01

    Uranium occurs in a variety of surficial environments in calcretes, gypcretes, silcretes, dolocretes and in organic sediments. Groundwater moving on low gradients generates these formations and, under favourable circumstances, uranium deposits. A variety of geomorphic settings can be involved. Most surficial deposits are formed in desert, temperate wetland, tropical, or transitional environments. The largest deposits known are in sedimentary environments in arid lands. The deposits form largely by the interaction of ground or surface waters on the geomorphic surface in favourable geologic terrains and climates. The deposits are commonly in the condition of being formed or reconstituted, or being destroyed. Carnotite is common in desert deposits while in wetland deposits no uranium minerals may be seen. Radioactive disequilibrium is common, particularly in wetland deposits. Granites and related rocks are major source rocks and most large deposits are in regions with enriched uranium contents, i.e. significantly greater than 5 ppm uranium. Uranium dissolution and transport is usually under oxidizing conditions. Transport in desert conditions is usually as a bicarbonate. A variety of fixation mechanisms operate to extract the uranium and form the deposits. Physical barriers to groundwater flow may initiate ore deposition. Mining costs are likely to be low because of the near surface occurrence, but there may be processing difficulties as clay may be present and the saline or carbonate content may be high. (author)

  19. Pulmonary artery stiffness in chronic obstructive pulmonary disease (COPD) and emphysema: The Multi-Ethnic Study of Atherosclerosis (MESA) COPD Study.

    Science.gov (United States)

    Liu, Chia-Ying; Parikh, Megha; Bluemke, David A; Balte, Pallavi; Carr, James; Dashnaw, Stephen; Poor, Hooman D; Gomes, Antoinette S; Hoffman, Eric A; Kawut, Steven M; Lima, Joao A C; McAllister, David A; Prince, Martin A; Vogel-Claussen, Jens; Barr, R Graham

    2018-01-01

    Chronic obstructive pulmonary disease (COPD) and particularly emphysema are characterized by stiffness of the aorta, due in part to accelerated elastin degradation in the lungs and aorta. Stiffness of the pulmonary arteries (PAs) may also be increased in COPD and emphysema, but data are lacking. We assessed PA stiffness using MRI in patients with COPD and related these measurements to COPD severity and percent emphysema. The Multi-Ethnic Study of Atherosclerosis (MESA) COPD Study recruited 290 participants, age 50-79 years with 10 or more packyears and free of clinical cardiovascular disease. COPD severity were defined on postbronchodilator spirometry by ATS/ERS criteria. Percent emphysema was defined as the percentage of regions of the lung COPD compared with controls (P = 0.002) and was inversely correlated with COPD severity (P = 0.004). PA strain was inversely associated to percent emphysema (P = 0.01). PA strain was also markedly correlated with right ventricular diastolic dysfunction measured by E/A ratios in the fully adjusted mix models (P = 0.02). PA strain is reduced in COPD, related in part to percent emphysema on CT scan, which may have implications for pulmonary small vessel flow and right ventricular function. 2 Technical Efficacy: Stage 1 J. Magn. Reson. Imaging 2018;47:262-271. © 2017 International Society for Magnetic Resonance in Medicine.

  20. Effect of heat treatment on the characteristics of tool steel deposited by the directed energy deposition process

    Science.gov (United States)

    Park, Jun Seok; Lee, Min-Gyu; Cho, Yong-Jae; Sung, Ji Hyun; Jeong, Myeong-Sik; Lee, Sang-Kon; Choi, Yong-Jin; Kim, Da Hye

    2016-01-01

    The directed energy deposition process has been mainly applied to re-work and the restoration of damaged steel. Differences in material properties between the base and the newly deposited materials are unavoidable, which may affect the mechanical properties and durability of the part. We investigated the effect of heat treatment on the characteristics of tool steel deposited by the DED process. We prepared general tool steel materials of H13 and D2 that were deposited onto heat-treated substrates of H13 and D2, respectively, using a direct metal tooling process. The hardness and microstructure of the deposited steel before and after heat treatment were investigated. The hardness of the deposited H13 steel was higher than that of wrought H13 steel substrate, while that of the deposited D2 was lower than that of wrought D2. The evolution of the microstructures by deposition and heat treatment varied depending on the materials. In particular, the microstructure of the deposited D2 steel after heat treatment consisted of fine carbides in tempered martensite and it is expected that the deposited D2 steel will have isotropic properties and high hardness after heat treatment.

  1. Laser deposition of HTSC films

    International Nuclear Information System (INIS)

    Sobol', Eh.N.; Bagratashvili, V.N.; Zherikhin, A.N.; Sviridov, A.P.

    1990-01-01

    Studies of the high-temperature superconducting (HTSC) films fabrication by the laser deposition are reviewed. Physical and chemical processes taking place during laser deposition are considered, such as the target evaporation, the material transport from the target to the substrate, the film growth on the substrate, thermochemical reactions and mass transfer within the HTSC films and their stability. The experimental results on the laser deposition of different HTSC ceramics and their properties investigations are given. The major technological issues are discussed including the deposition schemes, the oxygen supply, the target compositions and structure, the substrates and interface layers selection, the deposition regimes and their impact on the HTSC films properties. 169 refs.; 6 figs.; 2 tabs

  2. Atmospheric Deposition Modeling Results

    Data.gov (United States)

    U.S. Environmental Protection Agency — This asset provides data on model results for dry and total deposition of sulfur, nitrogen and base cation species. Components include deposition velocities, dry...

  3. Remedial actions at the former Climax Uranium Company Uranium Mill Site, Grand Junction, Mesa County, Colorado. Volume 1. Text. Draft environmental impact statement

    International Nuclear Information System (INIS)

    1986-03-01

    This statement evaluates and compares the environmental impacts associated with the remedial actions of the residual radioactive materials remaining at the inactive uranium processing site and associated vicinity properties at Grand Junction, Mesa County, Colorado. The site is a 114-acre tract of private and state owned land which contains approximately 3.1 million cubic yards of tailings and associated contaminated soils. The vicinity properties are homes, businesses, public buildings, and vacant lots which may have been contaminated during construction by the use of tailings as building material. An estimated 3465 vicinity properties would be cleaned up during remedial action of the tailings pile. This statement evaluates six alternatives for stabilization and disposal of the tailings and other contaminated materials: no action; stabilization at the Grand Junction site; disposal at the Cheney Reservoir site with truck transport; disposal at the Cheney Reservoir site with train and truck transport; disposal at the Two Road site with truck transport; disposal at the Two Road site with train and truck transport. All of the alternatives except include remedial action at an estimated 3465 vicinity properties. Alternative 3 is DOE's preferred alternative. 29 figs., 25 tabs

  4. Adhesion Strength of Biomass Ash Deposits

    DEFF Research Database (Denmark)

    Laxminarayan, Yashasvi; Jensen, Peter Arendt; Wu, Hao

    2016-01-01

    . Therefore, timely removal of ash deposits is essential for optimal boiler operation. In order to improve the qualitative and quantitative understanding of deposit shedding in boilers, this study investigates the shear adhesion strength of biomass ash deposits on superheater tubes. Artificial biomass ash...... deposits were prepared on superheater tubes and sintered in an oven at temperatures up to 1000 °C. Subsequently, the deposits were sheared off by an electrically controlled arm, and the corresponding adhesion strength was measured. The results reveal the effect of temperature, ash/deposit composition......, sintering duration, and steel type on the adhesion strength....

  5. Application potential of sequence stratigraphy to prospecting for sandstone-type uranium deposit in continental depositional basins

    International Nuclear Information System (INIS)

    Li Shengxiang; Chen Zhaobo; Chen Zuyi; Xiang Weidong; Cai Yuqi

    2001-01-01

    Sequence stratigraphy has been widely used in hydrocarbon exploration and development, and great achievements have been achieved. However, its application to the prospecting for sandstone-type uranium deposits is just beginning. The metallogenic characteristics of sandstone-type uranium deposits and those of oil and gas are compared, and the relationship between sandstone-type uranium metallogenesis and the system tracts of sequence stratigraphy is studied. The authors propose that highest and system tracts are the main targets for prospecting interlayer oxidation zone type sandstone uranium deposits, and the incised valleys of low stand system tracts are favourable places for phreatic oxidation zone type sandstone uranium deposits, and transgressive system tracts are generally unfavorable to the formation of in-situ leachable sandstone-type uranium deposits. Finally, the authors look ahead the application potential of sequence stratigraphy to the prospecting for sandstone-type uranium deposits in continental depositional basins

  6. Trait anger but not anxiety predicts incident type 2 diabetes: The Multi-Ethnic Study of Atherosclerosis (MESA).

    Science.gov (United States)

    Abraham, Sherley; Shah, Nina G; Diez Roux, Ana; Hill-Briggs, Felicia; Seeman, Teresa; Szklo, Moyses; Schreiner, Pamela J; Golden, Sherita Hill

    2015-10-01

    Prior studies have shown a bidirectional association between depression and type 2 diabetes mellitus (T2DM); however, the prospective associations of anger and anxiety with T2DM have not been established. We hypothesized that trait anger and anxiety would predict incident T2DM, independently of depressive symptoms. In the Multi-ethnic Study of Atherosclerosis (MESA), we prospectively examined the association of trait anger and trait anxiety (assessed via the Spielberger Trait Anger and Anxiety Scales, respectively) with incident T2DM over 11.4 years in 5598 White, Black, Hispanic, and Chinese participants (53.2% women, mean age 61.6 years) at baseline without prevalent T2DM or cardiovascular disease. We used Cox proportional hazards models to calculate the hazard ratios (HR) of incident T2DM by previously defined anger category (low, moderate, high), and anxiety quartile, as there were no previously defined categories. High total trait anger was associated with incident T2DM (HR 1.50; 95% CI 1.08-2.07) relative to low total trait anger. The association was attenuated following adjustment for waist circumference (HR 1.32; 95% CI 0.94-1.86). Higher anger reaction was also associated with incident T2DM (HR=1.07; 95% CI 1.03-1.11) that remained significant after adjusting for potential confounders/explanatory factors. In contrast, trait anxiety did not predict incident T2DM. High total trait anger and anger reaction are potential modifiable risk factors for T2DM. Further research is needed to explore the mechanisms of the anger-diabetes relationship and to develop preventive interventions. Copyright © 2015 Elsevier Ltd. All rights reserved.

  7. 19 CFR 210.28 - Depositions.

    Science.gov (United States)

    2010-04-01

    ... 19 Customs Duties 3 2010-04-01 2010-04-01 false Depositions. 210.28 Section 210.28 Customs Duties UNITED STATES INTERNATIONAL TRADE COMMISSION INVESTIGATIONS OF UNFAIR PRACTICES IN IMPORT TRADE ADJUDICATION AND ENFORCEMENT Discovery and Compulsory Process § 210.28 Depositions. (a) When depositions may be...

  8. Global deposition of airborne dioxin.

    Science.gov (United States)

    Booth, Shawn; Hui, Joe; Alojado, Zoraida; Lam, Vicky; Cheung, William; Zeller, Dirk; Steyn, Douw; Pauly, Daniel

    2013-10-15

    We present a global dioxin model that simulates one year of atmospheric emissions, transport processes, and depositions to the earth's terrestrial and marine habitats. We map starting emission levels for each land area, and we also map the resulting deposits to terrestrial and marine environments. This model confirms that 'hot spots' of deposition are likely to be in northern Europe, eastern North America, and in parts of Asia with the highest marine dioxin depositions being the northeast and northwest Atlantic, western Pacific, northern Indian Ocean and the Mediterranean. It also reveals that approximately 40% of airborne dioxin emissions are deposited to marine environments and that many countries in Africa receive more dioxin than they produce, which results in these countries being disproportionately impacted. Since human exposure to dioxin is largely through diet, this work highlights food producing areas that receive higher atmospheric deposits of dioxin than others. Copyright © 2013 Elsevier Ltd. All rights reserved.

  9. Depositional environment of the San Miguel lignite deposit in Atascosa and McMullen Counties, Texas

    Energy Technology Data Exchange (ETDEWEB)

    Gowan, S.W.

    1985-01-01

    An analysis of the environment of deposition of the San Miguel lignite deposit was carried out in order to understand newly discovered characteristics of the deposit. The environment of deposition of the overburden and underburden was evaluated through an interpretation of three continuous cores. Four coal cores and a highwall section were carefully described to determine the depositional environmental of the coal seams and partings. These studies were supplemented by the construction of seam and parting isopachs, and the analysis of the distribution of sulfur isotopes, sulfur, forms, and total sulfur within the coal. The sedimentary package is composed of a basal prograding barrier that beach, dune, and back-barrier sands. This unit correlates with a downdip sand that was also interpreted as a prograding barrier by other authors. The barrier is overlain by a series of slit and clay deposits of lagoonal, tidal flat, and tidal channel origin. These deposits are capped by restricted lagoon sediments composed of green, calcareous clays that occasionally contain shell layers. The restricted lagoon deposits formed when the barrier closed the lagoon off from the sea. Peat forming freshwater swamps eventually became established behind the barrier and on top of the restricted lagoon sediments. The parting isopachs reveal a reticulate morphology similar to the mangrove swamps located lateral to the modern Niger River Delta. The partings represent vegetated tidal flat deposits that formed during periodic invasions by the sea that killed the swamp and inundated the peat with sulfate rich water. The lignite interval is capped by open lagoon and tidal flat sediments.

  10. Vertically aligned carbon nanotube growth by pulsed laser deposition and thermal chemical vapor deposition methods

    International Nuclear Information System (INIS)

    Sohn, Jung Inn; Nam, Chunghee; Lee, Seonghoon

    2002-01-01

    We have grown vertically aligned carbon nanotubes on the various substrates such as a planar p-type Si(1 0 0) wafer, porous Si wafer, SiO 2 , Si 3 N 4 , Al 2 O 3 , and Cr by thermal chemical vapor deposition (CVD) at 800 deg.C, using C 2 H 2 gas as a carbon source and Fe catalyst films deposited by a pulsed laser on the substrates. The Fe films were deposited for 5 min by pulsed laser deposition (PLD). The advantage of Fe deposition by PLD over other deposition methods lies in the superior adhesion of Fe to a Si substrate due to high kinetic energies of the generated Fe species. Scanning electron microscopy (SEM) images show that vertically well-aligned carbon nanotubes are grown on Fe nanoparticles formed from the thermal annealing of the Fe film deposited by PLD on the various substrates. Atomic force microscopy (AFM) images show that the Fe film annealed at 800 deg.C is broken to Fe nanoparticles of 10-50 nm in size. We show that the appropriate density of Fe nanoparticles formed from the thermal annealing of the film deposited by PLD is crucial in growing vertically aligned carbon nanotubes. Using a PLD and a lift-off method, we developed the selective growth of carbon nanotubes on a patterned Fe-coated Si substrate

  11. Understanding the spectrum of diesel injector deposits

    Energy Technology Data Exchange (ETDEWEB)

    Quigley, Robert; Barbour, Robert [Lubrizol Limited, Derby (United Kingdom); Arters, David; Bush, Jim [Lubrizol Corporation, Wickliffe, OH (United States)

    2013-06-01

    Understanding the origin of diesel fuel injector deposits used to be relatively simple; for the most part they were caused by the decomposition of fuel during the combustion process, were generally organic in nature and typically only affected the nozzle orifices. However, modem fuel injector designs appear to be both more severe in terms of generating conditions conducive to creating new and different types of deposits and more likely to have their operation affected by those deposits. Changes to fuel composition and type have in some cases increased the potential pool of reactive species or provided new potential deposit precursors. As a result, the universe of diesel injector deposits now range from the traditional organic to partially or fully inorganic in nature and from nozzle coking deposits to deposits which can seize the internal components of the injector; so called internal diesel injector deposits. Frequently, combinations of inorganic and organic deposits are found. While power loss is one well known issue associated with nozzle deposits, other field problems resulting from these new deposits include severe issues with drivability, emissions, fuel consumption and even engine failure. Conventional deposit control additive chemistries were developed to be effective against organic nozzle coking deposits. These conventional additives in many cases may prove ineffective against this wide range of deposit types. This paper discusses the range of deposits that have been found to adversely impact modem diesel fuel injectors and compares the performance of conventional and new, advanced deposit control additives against these various challenges to proper fuel injector functioning. (orig.)

  12. A Micrometeorological Perspective on Deposition

    DEFF Research Database (Denmark)

    Jensen, Niels Otto

    1981-01-01

    An expression for the dry deposition velocity is given in terms of constant flux layer scaling. Numerical values of upper bounds on the deposition velocity is given for a typical situation. Some remarks are then offered on the relative merits of various ways in which the combined diffusion-deposition...

  13. Chemical bath deposited and dip coating deposited CuS thin films - Structure, Raman spectroscopy and surface study

    Science.gov (United States)

    Tailor, Jiten P.; Khimani, Ankurkumar J.; Chaki, Sunil H.

    2018-05-01

    The crystal structure, Raman spectroscopy and surface microtopography study on as-deposited CuS thin films were carried out. Thin films deposited by two techniques of solution growth were studied. The thin films used in the present study were deposited by chemical bath deposition (CBD) and dip coating deposition techniques. The X-ray diffraction (XRD) analysis of both the as-deposited thin films showed that both the films possess covellite phase of CuS and hexagonal unit cell structure. The determined lattice parameters of both the films are in agreement with the standard JCPDS as well as reported data. The crystallite size determined by Scherrer's equation and Hall-Williamsons relation using XRD data for both the as-deposited thin films showed that the respective values were in agreement with each other. The ambient Raman spectroscopy of both the as-deposited thin films showed major emission peaks at 474 cm-1 and a minor emmision peaks at 265 cm-1. The observed Raman peaks matched with the covellite phase of CuS. The atomic force microscopy of both the as-deposited thin films surfaces showed dip coating thin film to be less rough compared to CBD deposited thin film. All the obtained results are presented and deliberated in details.

  14. AlN/GaN-Based MOS-HEMT Technology: Processing and Device Results

    Directory of Open Access Journals (Sweden)

    S. Taking

    2011-01-01

    Full Text Available Process development of AlN/GaN MOS-HEMTs is presented, along with issues and problems concerning the fabrication processes. The developed technology uses thermally grown Al2O3 as a gate dielectric and surface passivation for devices. Significant improvement in device performance was observed using the following techniques: (1 Ohmic contact optimisation using Al wet etch prior to Ohmic metal deposition and (2 mesa sidewall passivation. DC and RF performance of the fabricated devices will be presented and discussed in this paper.

  15. Calcium Pyrophosphate Deposition (CPPD)

    Science.gov (United States)

    ... Patient / Caregiver Diseases & Conditions Calcium Pyrophosphate Deposition (CPPD) Calcium Pyrophosphate Deposition (CPPD) Fast Facts The risk of ... young people, too. Proper diagnosis depends on detecting calcium pyrophosphate crystals in the fluid of an affected ...

  16. Aerosol Deposition in Health and Disease

    Science.gov (United States)

    2012-01-01

    Abstract The success of inhalation therapy is not only dependent upon the pharmacology of the drugs being inhaled but also upon the site and extent of deposition in the respiratory tract. This article reviews the main mechanisms affecting the transport and deposition of inhaled aerosol in the human lung. Aerosol deposition in both the healthy and diseased lung is described mainly based on the results of human studies using nonimaging techniques. This is followed by a discussion of the effect of flow regime on aerosol deposition. Finally, the link between therapeutic effects of inhaled drugs and their deposition pattern is briefly addressed. Data show that total lung deposition is a poor predictor of clinical outcome, and that regional deposition needs to be assessed to predict therapeutic effectiveness. Indeed, spatial distribution of deposited particles and, as a consequence, drug efficiency is strongly affected by particle size. Large particles (>6 μm) tend to mainly deposit in the upper airway, limiting the amount of drugs that can be delivered to the lung. Small particles (<2 μm) deposit mainly in the alveolar region and are probably the most apt to act systemically, whereas the particle in the size range 2–6 μm are be best suited to treat the central and small airways. PMID:22686623

  17. 50 CFR 259.34 - Minimum and maximum deposits; maximum time to deposit.

    Science.gov (United States)

    2010-10-01

    ... B objective. A time longer than 10 years, either by original scheduling or by subsequent extension... OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE AID TO FISHERIES CAPITAL CONSTRUCTION FUND...) Minimum annual deposit. The minimum annual (based on each party's taxable year) deposit required by the...

  18. Electrostatic Deposition of Large-Surface Graphene

    Directory of Open Access Journals (Sweden)

    Charles Trudeau

    2018-01-01

    Full Text Available This work describes a method for electrostatic deposition of graphene over a large area using controlled electrostatic exfoliation from a Highly Ordered Pyrolytic Graphite (HOPG block. Deposition over 130 × 130 µm2 with 96% coverage is achieved, which contrasts with sporadic micro-scale depositions of graphene with little control from previous works on electrostatic deposition. The deposition results are studied by Raman micro-spectroscopy and hyperspectral analysis using large fields of view to allow for the characterization of the whole deposition area. Results confirm that laser pre-patterning of the HOPG block prior to cleaving generates anchor points favoring a more homogeneous and defect-free HOPG surface, yielding larger and more uniform graphene depositions. We also demonstrate that a second patterning of the HOPG block just before exfoliation can yield features with precisely controlled geometries.

  19. Influence of deposition parameters on morphological properties of biomedical calcium phosphate coatings prepared using electrostatic spray deposition

    International Nuclear Information System (INIS)

    Leeuwenburgh, S.C.G.; Wolke, J.G.C.; Schoonman, J.; Jansen, J.A.

    2005-01-01

    In order to deposit biomedical calcium phosphate (CaP) coatings with a defined surface morphology, the electrostatic spray deposition (ESD) technique was used since this technique offers the possibility to deposit ceramic coatings with a variety of surface morphologies. A scanning electron microscopical study was performed in order to investigate the influence of several deposition parameters on the final morphology of the deposited coatings. The chemical characteristics of the coatings were studied by means of X-ray diffraction and Fourier-transform infrared spectroscopy. Regarding the chemical coating properties, the results showed that the coatings can be described as crystalline carbonate apatite coatings, a crystal phase which is similar to the mineral phase of bone and teeth. The morphology of CaP coatings, deposited using the ESD technique, was strongly dependent on the deposition parameters. By changing the nozzle-to-substrate distance, the precursor liquid flow rate and the deposition temperature, coating morphologies were deposited, which varied from dense to highly porous, reticular morphologies. The formation of various morphologies was the result of an equilibrium between the relative rates of CaP solute precipitation/reaction, solvent evaporation and droplet spreading onto the substrate surface

  20. 42 CFR 422.388 - Deposits.

    Science.gov (United States)

    2010-10-01

    ... to CMS. (2) The deposit must at all times have a fair market value of an amount that is 120 percent... is made; (2) The fair market value exceeds the amount of the required deposit; or (3) The required... PROGRAM MEDICARE ADVANTAGE PROGRAM Provider-Sponsored Organizations § 422.388 Deposits. (a) Insolvency...

  1. Micromorphology of modern tills in southwestern Spitsbergen – insights into depositional and post-depositional processes

    Directory of Open Access Journals (Sweden)

    Skolasińska Katarzyna

    2016-12-01

    Full Text Available Textural properties and microstructures are commonly used properties in the analysis of Pleistocene and older glacial deposits. However, contemporary glacial deposits are seldom studied, particularly in the context of post-depositional changes. This paper presents the results of a micromorphological study of recently deposited tills in the marginal zones of Hansbreen and Torellbreen, glaciers in southwestern Spitsbergen. The main objectives of this study were to compare modern tills deposited in subglacial and supraglacial conditions, as well as tills that were freshly released from ice with those laid down several decades ago. The investigated tills are primarily composed of large clasts of metamorphic rocks and represent coarse-grained, matrix-supported diamictons. The tills reveal several characteristic features for ductile (e.g. turbate structures and brittle (e.g. lineations, microshears deformations, which have been considered to be indicative of subglacial conditions. In supraglacial tills, the same structures are common as in the subglacial deposits, which points to the preservation of the primary features, though the sediment was transferred up to the glacier surface due to basal ice layer deformation and redeposited as slumps, or to formation of similar structures due to short-distance sediment re-deposition by mass flows. This study revealed that it might not be possible to distinguish subglacial and supraglacial tills on the basis of micromorphology if the latter are derived from a subglacial position. The only noted difference was the presence of iron oxide cementation zones and carbonate dissolution features in supraglacial tills. These features were found in tills that were deposited at least a few years ago and are interpreted to be induced by early post-depositional processes involving porewater/sediment interactions.

  2. Predictors of Long-Term Healthy Arterial Aging: Coronary Artery Calcium Nondevelopment in the MESA Study.

    Science.gov (United States)

    Whelton, Seamus P; Silverman, Michael G; McEvoy, John W; Budoff, Matthew J; Blankstein, Ron; Eng, John; Blumenthal, Roger S; Szklo, Moyses; Nasir, Khurram; Blaha, Michael J

    2015-12-01

    This study sought to determine the predictors of healthy arterial aging. Long-term nondevelopment of coronary artery calcification (persistent CAC = 0) is a marker of healthy arterial aging. The predictors of this phenotype are not known. We analyzed 1,850 participants from MESA (Multi-Ethnic Study of Atherosclerosis) with baseline CAC = 0 who underwent a follow-up CAC scan at visit 5 (median 9.6 years after baseline). We examined the proportion with persistent CAC = 0 and calculated multivariable relative risks and area under the receiver operating characteristic curve for prediction of this healthy arterial aging phenotype. We found that 55% of participants (n = 1,000) had persistent CAC = 0, and these individuals were significantly more likely to be younger, female, and have fewer traditional risk factors (RF). Participants with an ASCVD (Atherosclerotic Cardiovascular Disease Risk Score) risk score healthy arterial aging than were participants with an ASCVD score ≥7.5%. There was no significant association between the Healthy Lifestyle variables (body mass index, physical activity, Mediterranean diet, and never smoking) and persistent CAC = 0. The area under the receiver operating characteristic curve incorporating age, sex, and ethnicity was 0.65, indicating fair to poor discrimination. No single traditional RF or combination of other risk factors increased the area under the receiver operating characteristic curve by more than 0.05. Whereas participants free of traditional cardiovascular disease RF were significantly more likely to have persistent CAC = 0, there was no single RF or specific low-risk RF phenotype that markedly improved the discrimination of persistent CAC = 0 over demographic variables. Therefore, we conclude that healthy arterial aging may be predominantly influenced by the long-term maintenance of a low cardiovascular disease risk profile or yet to be determined genetic factors rather than the absence of any specific RF cluster identified

  3. Time Resolved Deposition Measurements in NSTX

    International Nuclear Information System (INIS)

    Skinner, C.H.; Kugel, H.; Roquemore, A.L.; Hogan, J.; Wampler, W.R.

    2004-01-01

    Time-resolved measurements of deposition in current tokamaks are crucial to gain a predictive understanding of deposition with a view to mitigating tritium retention and deposition on diagnostic mirrors expected in next-step devices. Two quartz crystal microbalances have been installed on NSTX at a location 0.77m outside the last closed flux surface. This configuration mimics a typical diagnostic window or mirror. The deposits were analyzed ex-situ and found to be dominantly carbon, oxygen, and deuterium. A rear facing quartz crystal recorded deposition of lower sticking probability molecules at 10% of the rate of the front facing one. Time resolved measurements over a 4-week period with 497 discharges, recorded 29.2 (micro)g/cm 2 of deposition, however surprisingly, 15.9 (micro)g/cm 2 of material loss occurred at 7 discharges. The net deposited mass of 13.3 (micro)g/cm 2 matched the mass of 13.5 (micro)g/cm 2 measured independently by ion beam analysis. Monte Carlo modeling suggests that transient processes are likely to dominate the deposition

  4. Controllable deposition of gadolinium doped ceria electrolyte films by magnetic-field-assisted electrostatic spray deposition

    International Nuclear Information System (INIS)

    Ksapabutr, Bussarin; Chalermkiti, Tanapol; Wongkasemjit, Sujitra; Panapoy, Manop

    2013-01-01

    This paper describes a simple and low-temperature approach to fabrication of dense and crack-free gadolinium doped ceria (GDC) thin films with controllable deposition by a magnetic-field-assisted electrostatic spray deposition technique. The influences of external permanent magnets on the deposition of GDC films were investigated. The coating area deposited using two magnets with the same pole arrangement decreased in comparison with the case of no magnets, whereas the largest deposition area was obtained in the system of the opposite poles. Analysis of as-deposited films at 450 °C indicated the formation of uniform, smooth and dense thin films with a single-phase fluorite structure. The films produced in the system using same poles were thicker, smaller in crystallite size and smoother than those fabricated under other conditions. Additionally, the GDC film deposited using the same pole arrangement showed the maximum in electrical conductivity of about 2.5 × 10 −2 S/cm at a low operating temperature of 500 °C. - Highlights: • Magnetic-field-assisted electrostatic spray allows a controllable coating. • Dense, crack-free thin films were obtained at low process temperature of 450 °C. • Control of deposition, thickness and uniformity is easy to achieve simultaneously. • Films from the same pole were thicker, smaller in crystal size and smoother. • The maximum conductivity of doped ceria film was 2.5 × 10 −2 S/cm at 500 °C

  5. Factors influencing chloride deposition in a coastal hilly area and application to chloride deposition mapping

    Directory of Open Access Journals (Sweden)

    H. Guan

    2010-05-01

    Full Text Available Chloride is commonly used as an environmental tracer for studying water flow and solute transport in the environment. It is especially useful for estimating groundwater recharge based on the commonly used chloride mass balance (CMB method. Strong spatial variability in chloride deposition in coastal areas is one difficulty encountered in appropriately applying the method. A high-resolution bulk chloride deposition map in the coastal region is thus needed. The aim of this study is to construct a chloride deposition map in the Mount Lofty Ranges (MLR, a coastal hilly area of approximately 9000 km2 spatial extent in South Australia. We examined geographic (related to coastal distance, orographic, and atmospheric factors that may influence chloride deposition, using partial correlation and regression analyses. The results indicate that coastal distance, elevation, as well as terrain aspect and slope, appear to be significant factors controlling chloride deposition in the study area. Coastal distance accounts for 70% of spatial variability in bulk chloride deposition, with elevation, terrain aspect and slope an additional 15%. The results are incorporated into a de-trended residual kriging model (ASOADeK to produce a 1 km×1 km resolution bulk chloride deposition and concentration maps. The average uncertainty of the deposition map is about 20–30% in the western MLR, and 40–50% in the eastern MLR. The maps will form a useful basis for examining catchment chloride balance for the CMB application in the study area.

  6. Market Discipline and Deposit Insurance

    OpenAIRE

    Peresetsky, Anatoly

    2008-01-01

    The paper examines Russian banks’ household deposit interest rates for the transition period of setting up the deposit insurance system. Monthly observations of Russian banks’ interest rates and balance sheets are used in a fixed effects panel data model. It is shown market discipline has been significantly diminished after switching to the deposit insurance.

  7. Restoration of uranium solution mining deposits

    International Nuclear Information System (INIS)

    Devries, F.W.; Lawes, B.C.

    1982-01-01

    A process is provided for restoring an ore deposit after uranium solution mining using ammonium carbonate leaching solutions has ceased. The process involves flushing the deposit with an aqueous solution of a potassium salt during which potassium ions exchange with ammonium ions remaining in the deposit. The ammonium containing flushing solution is withdrawn from the deposit for disposal

  8. Restoration of uranium solution mining deposits

    Energy Technology Data Exchange (ETDEWEB)

    Devries, F.W.; Lawes, B.C.

    1982-01-19

    A process is provided for restoring an ore deposit after uranium solution mining using ammonium carbonate leaching solutions has ceased. The process involves flushing the deposit with an aqueous solution of a potassium salt during which potassium ions exchange with ammonium ions remaining in the deposit. The ammonium containing flushing solution is withdrawn from the deposit for disposal.

  9. Legal Deposit of Electronic Publications

    Directory of Open Access Journals (Sweden)

    Burcu Umut Zan

    2009-06-01

    Full Text Available The most important and basic role of the deposition studies, which are the greatest contributions to the knowledge sharing, is to gather the artistic and philosophical works of a country and provide them for the use of future researchers. However, since early deposition studies were limited with printed publications, they do not involve the electronic publication types appearing with the development of information technology. This stems from the fact that the electronic publications require procedures different from those of the printed publications in terms of deposition steps because of their structures. Today, in order to guarantee that all registered cultural products, which are mostly produced and used in the electronic environment could be fully collected, electronic publications should also be covered by and regulated under legal deposit. This study analyzes the deposition of electronic publications, within the framework of their storage and protection, being put in the use of the users as well as the common approaches to deposition practices in the world parallel to the developments in the information technology. The related situation in Turkey was also evaluated.

  10. A radon progeny deposition model

    International Nuclear Information System (INIS)

    Rielage, Keith; Elliott, Steven R.; Hime, Andrew; Guiseppe, Vincent E.; Westerdale, S.

    2010-01-01

    The next generation low-background detectors operating underground aim for unprecedented low levels of radioactive backgrounds. Although the radioactive decays of airborne radon (particularly 222 Rn) and its subsequent progeny present in an experiment are potential backgrounds, also problematic is the deposition of radon progeny on detector materials. Exposure to radon at any stage of assembly of an experiment can result in surface contamination by progeny supported by the long half life (22 y) of 210 Pb on sensitive locations of a detector. An understanding of the potential surface contamination from deposition will enable requirements of radon-reduced air and clean room environments for the assembly of low background experiments. It is known that there are a number of environmental factors that govern the deposition of progeny onto surfaces. However, existing models have not explored the impact of some environmental factors important for low background experiments. A test stand has been constructed to deposit radon progeny on various surfaces under a controlled environment in order to develop a deposition model. Results from this test stand and the resulting deposition model are presented.

  11. A Radon Progeny Deposition Model

    International Nuclear Information System (INIS)

    Guiseppe, V. E.; Elliott, S. R.; Hime, A.; Rielage, K.; Westerdale, S.

    2011-01-01

    The next generation low-background detectors operating underground aim for unprecedented low levels of radioactive backgrounds. Although the radioactive decays of airborne radon (particularly 222 Rn) and its subsequent progeny present in an experiment are potential backgrounds, also problematic is the deposition of radon progeny on detector materials. Exposure to radon at any stage of assembly of an experiment can result in surface contamination by progeny supported by the long half life (22 y) of 210 Pb on sensitive locations of a detector. An understanding of the potential surface contamination from deposition will enable requirements of radon-reduced air and clean room environments for the assembly of low background experiments. It is known that there are a number of environmental factors that govern the deposition of progeny onto surfaces. However, existing models have not explored the impact of some environmental factors important for low background experiments. A test stand has been constructed to deposit radon progeny on various surfaces under a controlled environment in order to develop a deposition model. Results from this test stand and the resulting deposition model are presented.

  12. Uranium deposit research, 1983

    International Nuclear Information System (INIS)

    Ruzicka, V.; LeCheminant, G.M.

    1984-01-01

    Research on uranium deposits in Canada, conducted as a prerequisite for assessment of the Estimated Additional Resources of uranium, revealed that (a) the uranium-gold association in rudites of the Huronian Supergroup preferably occurs in the carbon layers; (b) chloritized ore at the Panel mine, Elliot Lake, Ontario, occurs locally in tectonically disturbed areas in the vicinity of diabase dykes; (c) mineralization in the Black Sturgeon Lake area, Ontario, formed from solutions in structural and lithological traps; (d) the Cigar Lake deposit, Saskatchewan, has two phases of mineralization: monomineralic and polymetallic; (e) mineralization of the JEB (Canoxy Ltd.) deposit is similar to that at McClean Lake; (f) the uranium-carbon assemblage was identified in the Claude deposit, Carswell Structure; and (g) the Otish Mountains area, Quebec, should be considered as a significant uranium-polymetallic metallogenic province

  13. Deposition and Resuspension of Particles

    DEFF Research Database (Denmark)

    Lengweiler, P.; Nielsen, Peter V.; Moser, A.

    A new experimental set-up to investigate the physical process of dust deposition and resuspension on and from surfaces is introduced. Dust deposition can reduce the airBorne dust concentration considerably. As a basis for developing methods to eliminate dust related problems in rooms......, there is a need for better understanding of the mechanism of dust deposition and resuspension....

  14. Felsic magmatism and uranium deposits

    International Nuclear Information System (INIS)

    Cuney, M.

    2014-01-01

    Uranium strongly incompatible behaviour in silicate magmas results in its concentration in the most felsic melts and a prevalence of granites and rhyolites as primary U sources for the formation of U deposits. Despite its incompatible behaviour, U deposits resulting directly from magmatic processes are quite rare. In most deposits, U is mobilized by hydrothermal fluids or ground water well after the emplacement of the igneous rocks. Of the broad range of granite types, only a few have have U contents and physico-chemical properties that permit the crystallization of accessory minerals from which uranium can be leached for the formation of U deposits. The first granites on Earth which crystallized uraninite appeared at 3.1 Ga, are the potassic granites from the Kaapval craton (South Africa) which were also the source of the detrital uraninite for the Dominion Reef and Witwatersrand quartz pebble conglomerate deposits. Four types of granites or rhyolites can be sufficiently enriched in U to represent a significant source for the genesis of U deposits: peralkaline, high-K metaluminous calc-alkaline, L-type peraluminous ones and anatectic pegmatoids. L-type peraluminous plutonic rocks in which U is dominantly hosted in uraninite or in the glass in their volcanic equivalents represent the best U source. Peralkaline granites or syenites represent the only magmatic U-deposits formed by extreme fractional crystallization. The refractory character of the U-bearing minerals does not permit their extraction at the present economic conditions and make them unfavourable U sources for other deposit types. By contrast, felsic peralkaline volcanic rocks, in which U is dominantly hosted in the glassy matrix, represent an excellent source for many deposit types. High-K calc-alkaline plutonic rocks only represent a significant U source when the U-bearing accessory minerals [U-thorite, allanite, Nb oxides] become metamict. The volcanic rocks of the same geochemistry may be also a

  15. A remote coal deposit revisited

    DEFF Research Database (Denmark)

    Bojesen-Kofoed, Jørgen A.; Kalkreuth, Wolfgang; Petersen, Henrik I.

    2012-01-01

    discovery. The outcrops found in 2009 amount to approximately 8 m of sediment including a coal seam of 2 m thickness. More outcrops and additional coal deposits most certainly are to be found, pending further fieldwork. The deposits are Middle Jurassic, Callovian, in age and were deposited in a floodplain...... environment related to meandering river channels. Spores and pollen in the lower fluvial deposits reflect abundant vegetation of ferns along the river banks. In contrast, a sparse spore and pollen flora in the coals show a mixed vegetation of ferns and gymnosperms. Based on proximate and petrographic analyses...

  16. Innate responses of the predatory mite Phytoseiulus persimilis to a herbivore-induced plant volatile.

    Science.gov (United States)

    Sznajder, B; Sabelis, M W; Egas, M

    2011-06-01

    The responses of the predatory mite P. persimilis to herbivore-induced plant volatiles are at least partly genetically determined. Thus, there is potential for the evolution of this behaviour by natural selection. We tested whether distinct predator genotypes with contrasting responses to a specific herbivore-induced plant volatile, i.e. methyl salicylate (MeSa), could be found in a base population collected in the field (Sicily). To this end, we imposed purifying selection on individuals within iso-female lines of P. persimilis such that the lines were propagated only via the individual that showed either a preference or avoidance of MeSa. The responses of the lines were characterized as the mean proportion of individuals choosing MeSa when given a choice between MeSa and clean air. Significant variation in predator responses was detected among iso-female lines, thus confirming the presence of a genetic component for this behaviour. Nevertheless, we did not find a significant difference in the response to MeSa between the lines that were selected to avoid MeSa and the lines selected to prefer MeSa. Instead, in the course of selection the lines selected to avoid MeSa shifted their mean response towards a preference for MeSa. An inverse, albeit weaker, shift was detected for the lines selected to prefer MeSa. We discuss the factors that may have caused the apparent lack of a response to selection within iso-female line in this study and propose experimental approaches that address them.

  17. Molecular modeling of the green leaf volatile methyl salicylate on atmospheric air/water interfaces.

    Science.gov (United States)

    Liyana-Arachchi, Thilanga P; Hansel, Amie K; Stevens, Christopher; Ehrenhauser, Franz S; Valsaraj, Kalliat T; Hung, Francisco R

    2013-05-30

    Methyl salicylate (MeSA) is a green leaf volatile (GLV) compound that is emitted in significant amounts by plants, especially when they are under stress conditions. GLVs can then undergo chemical reactions with atmospheric oxidants, yielding compounds that contribute to the formation of secondary organic aerosols (SOAs). We investigated the adsorption of MeSA on atmospheric air/water interfaces at 298 K using thermodynamic integration (TI), potential of mean force (PMF) calculations, and classical molecular dynamics (MD) simulations. Our molecular models can reproduce experimental results of the 1-octanol/water partition coefficient of MeSA. A deep free energy minimum was found for MeSA at the air/water interface, which is mainly driven by energetic interactions between MeSA and water. At the interface, the oxygenated groups in MeSA tend to point toward the water side of the interface, with the aromatic group of MeSA lying farther away from water. Increases in the concentrations of MeSA lead to reductions in the height of the peaks in the MeSA-MeSA g(r) functions, a slowing down of the dynamics of both MeSA and water at the interface, and a reduction in the interfacial surface tension. Our results indicate that MeSA has a strong thermodynamic preference to remain at the air/water interface, and thus chemical reactions with atmospheric oxidants are more likely to take place at this interface, rather than in the water phase of atmospheric water droplets or in the gas phase.

  18. Particle deposition in ventilation ducts

    Energy Technology Data Exchange (ETDEWEB)

    Sippola, Mark Raymond [Univ. of California, Berkeley, CA (United States)

    2002-09-01

    Exposure to airborne particles is detrimental to human health and indoor exposures dominate total exposures for most people. The accidental or intentional release of aerosolized chemical and biological agents within or near a building can lead to exposures of building occupants to hazardous agents and costly building remediation. Particle deposition in heating, ventilation and air-conditioning (HVAC) systems may significantly influence exposures to particles indoors, diminish HVAC performance and lead to secondary pollutant release within buildings. This dissertation advances the understanding of particle behavior in HVAC systems and the fates of indoor particles by means of experiments and modeling. Laboratory experiments were conducted to quantify particle deposition rates in horizontal ventilation ducts using real HVAC materials. Particle deposition experiments were conducted in steel and internally insulated ducts at air speeds typically found in ventilation ducts, 2-9 m/s. Behaviors of monodisperse particles with diameters in the size range 1-16 μm were investigated. Deposition rates were measured in straight ducts with a fully developed turbulent flow profile, straight ducts with a developing turbulent flow profile, in duct bends and at S-connector pieces located at duct junctions. In straight ducts with fully developed turbulence, experiments showed deposition rates to be highest at duct floors, intermediate at duct walls, and lowest at duct ceilings. Deposition rates to a given surface increased with an increase in particle size or air speed. Deposition was much higher in internally insulated ducts than in uninsulated steel ducts. In most cases, deposition in straight ducts with developing turbulence, in duct bends and at S-connectors at duct junctions was higher than in straight ducts with fully developed turbulence. Measured deposition rates were generally higher than predicted by published models. A model incorporating empirical equations based on the

  19. FDIC Summary of Deposits (SOD) Download File

    Data.gov (United States)

    Federal Deposit Insurance Corporation — The FDIC's Summary of Deposits (SOD) download file contains deposit data for branches and offices of all FDIC-insured institutions. The Federal Deposit Insurance...

  20. Electronic properties of p-GaAs deposited on n-Si with pulsed-laser deposition

    International Nuclear Information System (INIS)

    Ullrich, B; Erlacher, A; Smith, H E; Mitchel, W C; Brown, G J

    2008-01-01

    By means of nanosecond laser pulses at 355, 532, and 1064 nm, p(Zn)-type GaAs was ablated and deposited on n-type Si. The samples showed rectification and Hall measurements established that the deposited material was p-type, but the active-doping concentration was six orders of magnitude below the target value. Because secondary-ion mass spectroscopy results indicated stoichiometric material transfer, we concluded that most of the Zn atoms do not act as acceptors because of the amorphous film texture. The work further showed indications that pulsed-laser deposition at 355 nm causes enhanced Si diffusion into the deposited film, compared to the ablations done at 532 and 1064 nm

  1. Comparison of stress in single and multiple layer depositions of plasma-deposited amorphous silicon dioxide

    International Nuclear Information System (INIS)

    Au, V; Charles, C; Boswell, R W

    2006-01-01

    The stress in a single-layer continuous deposition of amorphous silicon dioxide (SiO 2 ) film is compared with the stress within multiple-layer intermittent or 'stop-start' depositions. The films were deposited by helicon activated reactive evaporation (plasma assisted deposition with electron beam evaporation source) to a 1 μm total film thickness. The relationships for stress as a function of film thickness for single, two, four and eight layer depositions have been obtained by employing the substrate curvature technique on a post-deposition etch-back of the SiO 2 film. At film thicknesses of less than 300 nm, the stress-thickness relationships clearly show an increase in stress in the multiple-layer samples compared with the relationship for the single-layer film. By comparison, there is little variation in the film stress between the samples when it is measured at 1 μm film thickness. Localized variations in stress were not observed in the regions where the 'stop-start' depositions occurred. The experimental results are interpreted as a possible indication of the presence of unstable, strained Si-O-Si bonds in the amorphous SiO 2 film. It is proposed that the subsequent introduction of a 'stop-start' deposition process places additional strain on these bonds to affect the film structure. The experimental stress-thickness relationships were reproduced independently by assuming a linear relationship between the measured bow and film thickness. The constants of the linear model are interpreted as an indication of the density of the amorphous film structure

  2. Uraniferous surficial deposits in Southern Africa

    International Nuclear Information System (INIS)

    Hambleton-Jones, B.B.; Levin, M.; Wagener, G.F.

    1986-01-01

    Surficial uranium deposits are located in the north-western Cape Province of South Africa, in the Namib Desert east of Walvis Bay in South West Africa/Namibia and in the Serule Block of Botswana. They have been classified into the valley-fill, lacustrine, and pedogenic types. Carnotite is the main uranium-bearing mineral in the larger surficial deposits, with other minerals such as soddyite and phosphuranylite occurring locally. Uraninite or urano-organic complexes occur in the reducing environments of the diatomaceous earth, peat-rich deposits. Economically, the valley-fill type is the most important, with the largest deposits occurring in South West Africa/Namibia. In South West Africa/Namibia the valley-fill surficial uranium deposits occur in the Tumas and Langer Heinrich formations of the Teriary to Recent Namib Group. The Tubas, Langer Heinrich, and Welwitchia deposits are discussed: in them, carnotite occurs in calcareous and gypsiferous fluvial gravels. The pedogenic deposit at Mile 72 occurs in weathered granite and overlying gypcrete and has little economic potential. The economic potential of the surficial deposits in the north-western Cape Province is very limited in comparison with their South West African/Namibian counterparts, but the most important deposits are the lacustrine type, in particular those containing peat and diatomaceous earth. The mechanisms for the precipitation and preservation of the uranium are discussed

  3. Undiscovered porphyry copper resources in the Urals—A probabilistic mineral resource assessment

    Science.gov (United States)

    Hammarstrom, Jane M.; Mihalasky, Mark J.; Ludington, Stephen; Phillips, Jeffrey; Berger, Byron R.; Denning, Paul; Dicken, Connie; Mars, John; Zientek, Michael L.; Herrington, Richard J.; Seltmann, Reimar

    2017-01-01

    A probabilistic mineral resource assessment of metal resources in undiscovered porphyry copper deposits of the Ural Mountains in Russia and Kazakhstan was done using a quantitative form of mineral resource assessment. Permissive tracts were delineated on the basis of mapped and inferred subsurface distributions of igneous rocks assigned to tectonic zones that include magmatic arcs where the occurrence of porphyry copper deposits within 1 km of the Earth's surface are possible. These permissive tracts outline four north-south trending volcano-plutonic belts in major structural zones of the Urals. From west to east, these include permissive lithologies for porphyry copper deposits associated with Paleozoic subduction-related island-arc complexes preserved in the Tagil and Magnitogorsk arcs, Paleozoic island-arc fragments and associated tonalite-granodiorite intrusions in the East Uralian zone, and Carboniferous continental-margin arcs developed on the Kazakh craton in the Transuralian zone. The tracts range from about 50,000 to 130,000 km2 in area. The Urals host 8 known porphyry copper deposits with total identified resources of about 6.4 million metric tons of copper, at least 20 additional porphyry copper prospect areas, and numerous copper-bearing skarns and copper occurrences.Probabilistic estimates predict a mean of 22 undiscovered porphyry copper deposits within the four permissive tracts delineated in the Urals. Combining estimates with established grade and tonnage models predicts a mean of 82 million metric tons of undiscovered copper. Application of an economic filter suggests that about half of that amount could be economically recoverable based on assumed depth distributions, availability of infrastructure, recovery rates, current metals prices, and investment environment.

  4. Hideout in steam generator tube deposits

    International Nuclear Information System (INIS)

    Balakrishnan, P.V.; Franklin, K.J.; Turner, C.W.

    1998-05-01

    Hideout in deposits on steam generator tubes was studied using tubes coated with magnetite. Hideout from sodium chloride solutions at 279 degrees C was followed using an on-line high-temperature conductivity probe, as well as by chemical analysis of solution samples from the autoclave in which the studies were done. Significant hideout was observed only at a heat flux greater than 200 kW/m 2 , corresponding to a temperature drop greater than 2 degrees C across the deposits. The concentration factor resulting from the hideout increased highly non-linearly with the heat flux (varying as high as the fourth power of the heat flux). The decrease in the apparent concentration factor with increasing deposit thickness suggested that the pores in the deposit were occupied by a mixture of steam and water, which is consistent with the conclusion from the thermal conductivity measurements on deposits in a separate study. Analyses of the deposits after the hideout tests showed no evidence of any hidden-out solute species, probably due to the concentrations being very near the detection limits and to their escape from the deposit as the tests were being ended. This study showed that hideout in deposits may concentrate solutes in the steam generator bulk water by a factor as high as 2 x 10 3 . Corrosion was evident under the deposit in some tests, with some chromium enrichment on the surface of the tube. Chromium enrichment usually indicates an acidic environment, but the mobility required of chromium to become incorporated into the thick magnetite deposit may indicate corrosion under an alkaline environment. An alkaline environment could result from preferential accumulation of sodium in the solution in the deposit during the hideout process. (author)

  5. Spatial atomic layer deposition: a route towards further industrialization of atomic layer deposition

    NARCIS (Netherlands)

    Poodt, P.; Cameron, D.C.; Dickey, E.; George, S.M.; Kuznetsov, Vladimir; Parsons, G.N.; Roozeboom, F.; Sundaram, G.; Vermeer, A.

    2012-01-01

    Spatial atomic layer deposition can be used as a high-throughput manufacturing technique in functional thin film deposition for applications such as flexible electronics. This; however, requires low-temperature processing and handling of flexible substrates. The authors investigate the process

  6. The effect of fog on radionuclide deposition velocities

    International Nuclear Information System (INIS)

    Gibb, R.; Carson, P.; Thompson, W.

    1997-01-01

    Current nuclear power station release models do not evaluate deposition under foggy atmospheric conditions. Deposition velocities and scavenging coefficients of radioactive particles entrained in fog are presented for the Point Lepreau area of the Bay of Fundy coast. It is recommended to calculate deposition based on fog deposition velocities. The deposition velocities can be calculated from common meteorological data. The range of deposition velocities is approximately 1 - 100 cm/s. Fog deposition is surface roughness dependent with forests having larger deposition and deposition velocities than soil or grasses. (author)

  7. Influence of the deposition geometry on the microstructure of sputter-deposited V-Al-C-N coatings

    Energy Technology Data Exchange (ETDEWEB)

    Darma, Susan; Krause, Baerbel; Doyle, Stephen; Mangold, Stefan; Baumbach, Tilo [ISS, Karlsruher Institut fuer Technologie (Germany); Ulrich, Sven; Stueber, Michael [IAM-AWP, Karlsruher Institut fuer Technologie (Germany)

    2012-07-01

    Multi-element hard coating materials such as V-Al-C-N are of great interest for many technological applications. Their mechanical properties depend on the composition and microstructure of the coating. In order to determine the optimum composition and deposition conditions of these complex materials, many samples are required. One powerful tool for reducing the number of experiments is based on the so-called combinatorial approach for thin film deposition: many different thin film samples can be realized simultaneously, exploiting the deposition gradient resulting from codeposition of several materials. We will present an X-ray diffraction study of the influence of the deposition geometry on the microstructure of V-Al-C-N coatings. The films were deposited by reactive RF magnetron sputtering from a segmented target composed of AlN and VC. Synchrotron radiation measurements where performed at the beamline PDIFF at ANKA. Significant texture changes were observed which can be attributed to the deposition geometry, as verified by calculations of the flux distribution. We conclude that codeposition can accelerate significantly the screening of new materials, under the condition that the desired property is not significantly influenced by the microstructural changes due to the deposition geometry.

  8. Electroless atomic layer deposition

    Science.gov (United States)

    Robinson, David Bruce; Cappillino, Patrick J.; Sheridan, Leah B.; Stickney, John L.; Benson, David M.

    2017-10-31

    A method of electroless atomic layer deposition is described. The method electrolessly generates a layer of sacrificial material on a surface of a first material. The method adds doses of a solution of a second material to the substrate. The method performs a galvanic exchange reaction to oxidize away the layer of the sacrificial material and deposit a layer of the second material on the surface of the first material. The method can be repeated for a plurality of iterations in order to deposit a desired thickness of the second material on the surface of the first material.

  9. Felsic magmatism and uranium deposits

    International Nuclear Information System (INIS)

    Cuney, Michel

    2014-01-01

    The strongly incompatible behaviour of uranium in silicate magmas results in its concentration in the most felsic melts and a prevalence of granites and rhyolites as primary U sources for the formation of U deposits. Despite its incompatible behavior, U deposits resulting directly from magmatic processes are quite rare. In most deposits, U is mobilized by hydrothermal fluids or ground water well after the emplacement of the igneous rocks. Of the broad range of granite types, only a few have U contents and physico-chemical properties that permit the crystallization of accessory minerals from which uranium can be leached for the formation of U deposits. The first granites on Earth, which crystallized uraninite, dated at 3.1 Ga, are the potassic granites from the Kaapval craton (South Africa) which were also the source of the detrital uraninite for the Dominion Reef and Witwatersrand quartz pebble conglomerate deposits. Four types of granites or rhyolites can be sufficiently enriched in U to represent a significant source for the genesis of U deposits: per-alkaline, high-K met-aluminous calc-alkaline, L-type peraluminous and anatectic pegmatoids. L-type peraluminous plutonic rocks in which U is dominantly hosted in uraninite or in the glass of their volcanic equivalents represent the best U source. Per-alkaline granites or syenites are associated with the only magmatic U-deposits formed by extreme fractional crystallization. The refractory character of the U-bearing minerals does not permit their extraction under the present economic conditions and make them unfavorable U sources for other deposit types. By contrast, felsic per-alkaline volcanic rocks, in which U is dominantly hosted in the glassy matrix, represent an excellent source for many deposit types. High-K calc-alkaline plutonic rocks only represent a significant U source when the U-bearing accessory minerals (U-thorite, allanite, Nb oxides) become metamict. The volcanic rocks of the same geochemistry may be

  10. Vein-type uranium deposits

    International Nuclear Information System (INIS)

    Rich, R.A.; Holland, H.D.; Petersen, U.

    1975-01-01

    A critical review is presented of published data bearing on the mineralogy, paragenesis, geochemistry, and origin of veiw-type uranium deposits. Its aim is to serve as a starting point for new research and as a basis for the development of new exploration strategies. During the formation of both vein and sandstone types of deposits uranium seems to have been dissolved by and transported in rather oxidized solutions, and deposited where these solutions encountered reducing agents such as carbon, sulfides, ferrous minerals and hydrocarbons. Granitic rocks abnormally enriched in uranium have apparently been the most common source for uranium in vein-type deposits. Oxidizing solutions have been derived either from the surface or from depth. Surface solutions saturated with atmospheric oxygen have frequently passed through red bed or clean sandstone conduits on their way to and from uranium source rocks. Deep solutions of non-surface origin have apparently become sufficiently oxidizing by passage through and equilibration with red beds. The common association of clean sandstones or red beds with uranium-rich granites in the vicinity of vein-type uranium deposits is probably not fortuitous, and areas where these rock types are found together are considered particularly favorable targets for uranium exploration

  11. Electrochemical deposition and characterization of zinc–nickel alloys deposited by direct and reverse current

    Directory of Open Access Journals (Sweden)

    JELENA B. BAJAT

    2005-12-01

    Full Text Available Zn–Ni alloys electrochemically deposited on steel under various deposition conditions were investigated. The alloys were deposited on a rotating disc electrode and on a steel panel from chloride solutions by direct and reverse current. The influence of reverse plating variables (cathodic and anodic current densities and their time duration on the composition, phase structure and corrosion properties were investigated. The chemical content and phase composition affect the anticorrosive properties of Zn–Ni alloys during exposure to a corrosive agent (3 % NaCl solution. It was shown that the Zn–Ni alloy electrodeposited by reverse current with a full period T = 1 s and r = 0.2 exhibits the best corrosion properties of all the investigated alloys deposited by reverse current.

  12. Effects of deposition period on the chemical bath deposited Cu4SnS4 thin films

    International Nuclear Information System (INIS)

    Kassim, Anuar; Wee Tee, Tan; Soon Min, Ho.; Nagalingam, Saravanan

    2010-01-01

    Cu 4 SnS 4 thin films were prepared by simple chemical bath deposition technique. The influence of deposition period on the structural, morphological and optical properties of films was studied. The films were characterized using X-ray diffraction, atomic force microscopy and UV-Vis Spectrophotometer. X-ray diffraction patterns indicated that the films were polycrystalline with prominent peak attributed to (221) plane of orthorhombic crystal structure. The films prepared at 80 min showed significant increased in the intensity of all diffractions. According to AFM images, these films indicated that the surface of substrate was covered completely. The obtained films also produced higher absorption characteristics when compared to the films prepared at other deposition periods based on optical absorption studies. The band gap values of films deposited at different deposition periods were in the range of 1.6-2.1 eV. Deposition for 80 min was found to be the optimum condition to produce good quality thin films under the current conditions. (author).

  13. Uso prático de marcadores moleculares para seleção assistida no melhoramento de uvas de mesa apirênicas Practical use of molecular markers for seedlessness assisted selection in grapevine breeding

    Directory of Open Access Journals (Sweden)

    Luís Fernando Revers

    2006-04-01

    Full Text Available A hipótese mais bem aceita atualmente para explicar a genética complexa da estenoespermocarpia, observada na videira, indica que a expressão deste fenótipo é controlada por três genes recessivos, independentemente herdados e controlados por um gene regulador dominante (sdI. Em estudo anterior, Lahogue et al. (1998 identificaram um marcador RAPD (Random Amplified Polymorphic DNA ligado ao gene sdI e utilizaram-no para desenvolver um SCAR (Sequence Characterized Amplified Region co-dominante denominado SCC8, que pode distinguir, em uma progênie, indivíduos com semente como também selecionar indivíduos apirênicos. Neste trabalho, são apresentados resultados da avaliação do potencial de aplicação do marcador molecular SCAR SCC8 para seleção assistida do caráter da apirenia no melhoramento de uvas de mesa sem sementes. A utilização deste marcador na seleção assistida para apirenia em uvas de mesa mostrou-se viável, e as conseqüências da sua utilização no programa de melhoramento da Embrapa Uva e Vinho são discutidas.The inheritance of seedlessness in grapevine is based on a complex genetic system, where the expression of three independently inherited recessive genes is controlled by a dominant regulator gene (sdI. In a previous study, Lahogue et al. (1998 identified a random amplified polymorphic DNA marker, tightly linked to the sdI gene and developed a codominant SCAR (Sequence Characterized Amplified Region marker named SCC8, that allows the distinction of seeded and seedless plants in a segregating progeny. The aim of the present work was to evaluate the usefullness of the SCAR marker SCC8 for assisted selection of the seedlessness character in grape breeding. According to our results, the use of the SCC8 marker is economically viable and the consequences of its use in the grapevine breeding program at Embrapa Uva e Vinho are discussed.

  14. The anthracite of Nazar-Aylok Deposit

    International Nuclear Information System (INIS)

    Pachadzhanov, D.N.; Valiev, Yu.Ya.

    2013-01-01

    Present article is devoted to anthracite of Nazar-Aylok Deposit. The ash content, composition of coals of Nazar-Aylok Deposit and thickness of deposit were considered. The coal samples were studied by means of neutron activation analysis.

  15. Surface deposition from radioactive plumes

    International Nuclear Information System (INIS)

    Garland, J.A.

    1980-01-01

    Accidents involving nuclear plants may release radioactive particles and gases to the atmosphere. Dry deposition of particles has been investigated mainly in the laboratory and a general understanding of the transfer mechanisms has been established. However there is apparently a substantial discrepancy between the few field observations of dry deposition of particles and laboratory measurements, particularly for 0.1 - 1 μm particles for which laboratory work shows very small deposition rates. In addition there are few estimates of deposition rates for forest and some other kinds of terrain. The most important gas in the context of a nuclear accident is I-131 and the behaviour of this gas at grass surfaces has received much attention. However smaller quantities of other gases and vapours may be released and the surface absorption of these species may require further investigation. In addition there is little knowledge of the behaviour of gases over many types of surface. The rate of deposition of particles and gases is influenced by many parameters including wind speed and the temperature stratification of the lower atmosphere. Conditions which give poor atmospheric dispersion usually give lower deposition velocities. Transfer to man depends on the availability of deposited materials on crops and grass. A wide range of isotopes including iodine and several metallic fission products are lost with a half life for residence on grass ranging from a few days to a few tens days, depending on climatic conditions

  16. Urban acid deposition in Greater Manchester

    Energy Technology Data Exchange (ETDEWEB)

    Lee, D.S.; Longhurst, J.W.S.; Gee, D.R.; Hare, S.E. (Manchester Polytechnic, Manchester (UK). Acid Rain Information Centre)

    1989-08-01

    Data are presented from a monitoring network of 18 bulk precipitation collectors and one wet-only collector in the urban area of Greater Manchester, in the north west of England. Weekly samples were analysed for all the major ions in precipitation along with gaseous nitrogen dioxide concentrations from diffusion tubes. Statistical analysis of the data shows significant spatial variation of non marine sulphate, nitrate, ammonium, acidity and calcium concentrations, and nitrogen dioxide concentrations. Calcium is thought to be responsible for the buffering of acidity and is of local origin. Wet deposition is the likely removal process for calcium in the atmosphere and probably by below cloud scavenging. Nitrate and ammonium concentrations and depositions show close spatial, temporal and statistical association. Examination of high simultaneous episodes of nitrate and ammonium deposition shows that these depositions cannot be explained in terms of trajectories and it is suggested that UK emissions of ammonia may be important. Statistical analysis of the relationships between nitrate and ammonium depositions, concentrations and precipitation amount suggest that ammonia from mesoscale sources reacts reversibly with nitric acid aerosol and is removed by below cloud scavenging. High episodes of the deposition of non marine sulphate are difficult to explain by trajectory analysis alone, perhaps suggesting local sources. In a comparison between wet deposition and bulk deposition, it was shown that only 15.2% of the non marine sulphur was dry deposited to the bulk precipitation collector. 63 refs., 86 figs., 31 tabs.

  17. Deposition of acidifying compounds

    International Nuclear Information System (INIS)

    Fowler, D.; Cape, J.N.; Sutton, M.A.; Mourne, R.; Hargreaves, K.J.; Duyzer, J.H.; Gallagher, M.W.

    1992-01-01

    Inputs of acidifying compounds to terrestrial ecosystems include deposition of the gases NO 2 , NO, HNO 2 , HNO 3 , NH 3 and SO 2 and the ions NO 3- , NH 4+ , SO 4 2- and H + in precipitation, cloud droplets and particles. Recent research has identified particular ecosystems and regions in which terrestrial effects are closely linked with specific deposition processes. This review paper identifies areas in which important developments have occurred during the last five years and attempts to show which aspects of the subject are most important for policy makers. Amongst the conclusions drawn, the authors advise that current uncertainties in estimates of S and N inputs by dry deposition should be incorporated in critical load calculations, and that, in regions dominated by wet deposition, spatial resolution of total inputs should be improved to match the current scales of information on landscape sensitivity to acidic inputs. 44 refs., 9 figs

  18. Few-mode vertical-cavity surface-emitting laser: Optional emission of transverse modes with different polarizations

    Science.gov (United States)

    Zhong, Chuyu; Zhang, Xing; Hofmann, Werner; Yu, Lijuan; Liu, Jianguo; Ning, Yongqiang; Wang, Lijun

    2018-05-01

    Few-mode vertical-cavity surface-emitting lasers that can be controlled to emit certain modes and polarization states simply by changing the biased contacts are proposed and fabricated. By directly etching trenches in the p-doped distributed Bragg reflector, the upper mesa is separated into several submesas above the oxide layer. Individual contacts are then deposited. Each contact is used to control certain transverse modes with different polarization directions emitted from the corresponding submesa. These new devices can be seen as a prototype of compact laser sources in mode division multiplexing communications systems.

  19. Carbonaceous deposits on naptha reforming catalysts

    International Nuclear Information System (INIS)

    Redwan, D.S.

    1999-01-01

    Carbonaceous deposits on naphtha reforming catalysts play a decisive role in limiting process performance. The deposits negatively after catalyst activity, selectivity and the production cycle of a semi regenerative reformer. The magnitude of negative effect of those deposits is directly proportional to their amounts and complexity. Investigations on used reforming catalysts samples reveal that the amount and type (complexity of the chemical nature) of carbonaceous deposits are directly proportional to the catalysts life on stream and the severity of operating conditions. In addition, the combustibility behavior of carbonaceous deposits on the catalyst samples taken from different reformers are found to be different. Optimal carbon removal, for in situ catalyst regeneration, requires the specific conditions be developed, based on the results of well designed and properly performed investigations of the amount and type of carbonaceous deposits. (author)

  20. Influence of deposition time on the properties of chemical bath deposited manganese sulfide thin films

    Directory of Open Access Journals (Sweden)

    Anuar Kassim

    2010-12-01

    Full Text Available Manganese sulfide thin films were chemically deposited from an aqueous solution containing manganese sulfate, sodium thiosulfate and sodium tartrate. The influence of deposition time (2, 3, 6 and 8 days on the properties of thin films was investigated. The structure and surface morphology of the thin films were studied by X-ray diffraction and atomic force microscopy, respectively. In addition, in order to investigate the optical properties of the thin films, the UV-visible spectrophotometry was used. The XRD results indicated that the deposited MnS2 thin films exhibited a polycrystalline cubic structure. The number of MnS2 peaks on the XRD patterns initially increased from three to six peaks and then decreased to five peaks, as the deposition time was increased from 2 to 8 days. From the AFM measurements, the film thickness and surface roughness were found to be dependent on the deposition time.