Geology of gemstone deposit Ugljarevats (Central Serbia) and contributions to genetic model

International Nuclear Information System (INIS)

Kureshevicj, Lidija; Vushovicj, Olivera; Delicj-Nikolicj, Ivana

2017-01-01

Silica gemstone deposit Ugljarevats is situated within the ophiolite sequence of the Vardar zone central deep fault. Genetic processes of this deposit are connected to the Neogene calc-alkaline magmatic activity of the Vardar zone and hydrothermal activity triggered by it. Based on surface occurrences of listwenitized serpentinite containing silica mineralization, it can be inferred that the ore body is an elongated oval stock. Within the stock of hydrothermally altered serpentinite, the gemstone mineralization occurs as veins, stock works and irregular bodies. Present gemstone types include chalcedony varieties (jasper, colourless and greenish chalcedony, carnelian and sard) and opal (opalized serpentinite). Homogenous pieces are very rare. Most often, various types of silica are intimately intermixed and combined. The mineralization has formed in two distinct hydrothermal phases, apparently in close time succession. Jasper and coloured chalcedony (and rare magnesite) are the products of the first phase of hydro- thermal activity, while the colourless chalcedony is formed in the second phase. Newly discovered type of silica vein with central-symmetrical parallel banding gives new contributions to a genetic model, proving the precipitation process and its products are unpredictably changeable, heterogeneous and depending on the evolution of the local environment physico-chemical conditions, notably the contents of impurities and system's openness degree. (author)

Nutrient stoichiometry in Sphagnum along a nitrogen deposition gradient in highly polluted region of Central-East Europe

Energy Technology Data Exchange (ETDEWEB)

Jirousek, Martin, E-mail: machozrut@mail.muni.c [Department of Botany and Zoology, Faculty of Science, Masaryk University, Kotlarska 2, 61137 Brno (Czech Republic); Hajek, Michal [Department of Botany and Zoology, Faculty of Science, Masaryk University, Kotlarska 2, 61137 Brno (Czech Republic); Bragazza, Luca [WSL Swiss Federal Institute for Forest, Snow and Landscape Research, Site Lausanne, Station 2, Case Postale 96, CH-1015 Lausanne (Switzerland); Ecole Polytechnique Federale de Lausanne (EPFL), Laboratory of Ecological Systems - ECOS, Batiment GR, Station 2, CH-1015 Lausanne (Switzerland); Department of Biology and Evolution, University of Ferrara, Corso Ercole I d' Este 32, I-44100 Ferrara (Italy)

2011-02-15

We investigated the variation of N:P and N:K ratio in ombrotrophic Sphagnum plants along a gradient of atmospheric N deposition from 1 to 2.5 g m{sup -2} year{sup -1} in Central-East Europe. The N:P and N:K ratio in Sphagnum capitula increased significantly along the N deposition gradient. Sphagnum species from the Cuspidata section were characterised by significantly lower ratios at low N deposition. When we compared the observed N:P ratios in Sphagnum plants with the values reported in a previous European-wide study, we found a correspondence in nutrient stoichiometry only for a few bogs: higher P concentration in Sphagnum capitula caused a lower N:P ratio in most of the study bogs so that Sphagnum plants still seem N-limited despite their N saturation. Interaction between summer water table decrease and aerial liming of surrounding forests is proposed as an explanation for this discrepancy. Local forestry practice interacting with climate thus alter N:P stoichiometry of Sphagnum along the N deposition gradient. - Research highlights: Despite high atmopsheric nitrogen deposition, Sphagnum mosses still have rather low N:P ratio. Regional climate and landscape management can enhance P and K availability in bogs. Sphagnum species of the Cuspidata section were characterised by lower N:P ratio. - Regional climate and local forestry practices are expected to alter nutrient stoichiometry in Sphagnum mosses at high atmospheric N deposition in Central-East Europe.

Nutrient stoichiometry in Sphagnum along a nitrogen deposition gradient in highly polluted region of Central-East Europe

International Nuclear Information System (INIS)

Jirousek, Martin; Hajek, Michal; Bragazza, Luca

2011-01-01

We investigated the variation of N:P and N:K ratio in ombrotrophic Sphagnum plants along a gradient of atmospheric N deposition from 1 to 2.5 g m -2 year -1 in Central-East Europe. The N:P and N:K ratio in Sphagnum capitula increased significantly along the N deposition gradient. Sphagnum species from the Cuspidata section were characterised by significantly lower ratios at low N deposition. When we compared the observed N:P ratios in Sphagnum plants with the values reported in a previous European-wide study, we found a correspondence in nutrient stoichiometry only for a few bogs: higher P concentration in Sphagnum capitula caused a lower N:P ratio in most of the study bogs so that Sphagnum plants still seem N-limited despite their N saturation. Interaction between summer water table decrease and aerial liming of surrounding forests is proposed as an explanation for this discrepancy. Local forestry practice interacting with climate thus alter N:P stoichiometry of Sphagnum along the N deposition gradient. - Research highlights: → Despite high atmopsheric nitrogen deposition, Sphagnum mosses still have rather low N:P ratio.→ Regional climate and landscape management can enhance P and K availability in bogs. → Sphagnum species of the Cuspidata section were characterised by lower N:P ratio. - Regional climate and local forestry practices are expected to alter nutrient stoichiometry in Sphagnum mosses at high atmospheric N deposition in Central-East Europe.

Spatial Databases of Geological, Geophysical, and Mineral Resource Data Relevant to Sandstone-Hosted Copper Deposits in Central Kazakhstan

Science.gov (United States)

Syusyura, Boris; Box, Stephen E.; Wallis, John C.

2010-01-01

Central Kazakhstan is host to one of the world's giant sandstone-hosted copper deposits, the Dzhezkazgan deposit, and several similar, smaller deposits. The United Stated Geological Survey (USGS) is assessing the potential for other, undiscovered deposits of this type in the surrounding region of central Kazakhstan. As part of this effort, Syusyura compiled and partially translated an array of mostly unpublished geologic, geophysical, and mineral resource data for this region in digital format from the archives of the former Union of Soviet Socialists Republics (of which Kazakhstan was one of the member republics until its dissolution in 1991), as well as from later archives of the Republic of Kazakhstan or of the Kazakhstan consulting firm Mining Economic Consulting (MEC). These digital data are primarily map-based displays of information that were transmitted either in ESRI ArcGIS, georeferenced format, or non-georeferenced map image files. Box and Wallis reviewed all the data, translated Cyrillic text where necessary, inspected the maps for consistency, georeferenced the unprojected map images, and reorganized the data into the filename and folder structure of this publication.

Gold deposits in the Xiaoqinling-Xiong'ershan region, Qinling mountains, central China

Science.gov (United States)

Mao, J.; Goldfarb, R.J.; Zhang, Z.; Xu, W.; Qiu, Yumin; Deng, J.

2002-01-01

The gold-rich Xiaoqinling-Xiong'ershan region in eastern Shaanxi and western Henan provinces, central China, lies about 30-50 km inland of the southern margin of the North China craton. More than 100 gold deposits and occurrences are concentrated in the Xiaoqinling (west), Xiaoshan (middle), and Xiong'ershan (east) areas. Late Archean gneiss of the Taihua Group, and Middle Proterozoic metavolcanic rocks of the Xiong'er Group are the main host rocks for the deposits. Mesozoic granitoids (ca. 178-104 Ma) are present in most gold districts, but deposits are typically hosted in the Precambrian basement rocks hundreds of meters to as far as 10 km from the intrusions and related hornfels zones. Deposits in the Xiaoqinling and Xiaoshan areas are best classified as orogenic gold deposits, with ores occurring in a number of distinct belts both in quartz veins and disseminated in altered metamorphic rocks. Alteration assemblages are dominated by quartz, sericite, pyrite, and carbonate minerals. The ore-forming fluids were low salinity, CO2-rich, and characterized by isotopically heavy ??18O. Four deposits (Dongchuang, Wenyu, Yangzhaiyu, and Dahu) in the Xiaoqinling area each contain resources of about 1 Moz Au. Some of the gold deposits in the Xiong'ershan area represent more shallowly emplaced tellurium-enriched orogenic systems, which include resources of approximately 1-1.5 Moz Au at Shanggong and Beiling (or Tantou). Others are epithermal deposits (e.g., Qiyugou and Dianfang) that are hosted in volcanic breccia pipes. Isotopic dates for all gold deposits, although often contradictory, generally cluster between 172-99 Ma and are coeval with emplacement of the post-kinematic granitoids. The gold deposits formed during a period of relaxation of far-field compressional stresses, clearly subsequent to the extensive Paleozoic-early Mesozoic accretion of are terranes and the Yangtze craton onto the southern margin of the North China craton. Hydrothermal and magmatic events

Geochemical evidence for the origin of late Quaternary loess in central Alaska

Science.gov (United States)

Muhs, D.R.; Budahn, J.R.

2006-01-01

Loess is extensive in central Alaska, but there are uncertainties about its source and the direction of paleo-winds that deposited it. Both northerly and southerly winds have been inferred. The most likely sources of loess are the Tanana River (south), the Nenana River (southeast), and the Yukon River (north). Late Quaternary loess in central Alaska has immobile trace-element compositions (Cr/Sc, Th/Ta, Th/ Sc, Th/U, Eu/Eu*, GdN/YbN) that indicate derivation mostly from the Tanana River. However, other ratios (As/Sb, Zr/Hf, LaN/YbN) and quantitative modeling indicate that the Yukon River was also a source. During the last glacial period, there may have been a longer residence time of the Siberian and Canadian high-pressure cells, along with a strengthened Aleutian low-pressure cell. This would have generated regional-scale northeasterly winds and explains derivation of loess from the Yukon River. However, superim-posed upon this synoptic-scale circulation, there may have been strong, southerly katabatic winds from expanded glaciers on the northern flank of the Alaska Range. These winds could have provided eolian silt from the Tanana River. Yukon River and Tanana River sediments are highly calcareous, whereas Fairbanks-area loess is not. This suggests that carbonate leaching in loess kept ahead of sedimentation and that late Quaternary loess in central Alaska was deposited relatively slowly. ?? 2006 NRC Canada.

Depositional architecture and sequence stratigraphy of the Upper Jurassic Hanifa Formation, central Saudi Arabia

Science.gov (United States)

El-Sorogy, Abdelbaset; Al-Kahtany, Khaled; Almadani, Sattam; Tawfik, Mohamed

2018-03-01

To document the depositional architecture and sequence stratigraphy of the Upper Jurassic Hanifa Formation in central Saudi Arabia, three composite sections were examined, measured and thin section analysed at Al-Abakkayn, Sadous and Maashabah mountains. Fourteen microfacies types were identified, from wackestones to boundstones and which permits the recognition of five lithofacies associations in a carbonate platform. Lithofacies associations range from low energy, sponges, foraminifers and bioclastic burrowed offshoal deposits to moderate lithoclstic, peloidal and bioclastic foreshoal deposits in the lower part of the Hanifa while the upper part is dominated by corals, ooidal and peloidal high energy shoal deposits to moderate to low energy peloidal, stromatoporoids and other bioclastics back shoal deposits. The studied Hanifa Formation exhibits an obvious cyclicity, distinguishing from vertical variations in lithofacies types. These microfacies types are arranged in two third order sequences, the first sequence is equivalent to the lower part of the Hanifa Formation (Hawtah member) while the second one is equivalent to the upper part (Ulayyah member). Within these two sequences, there are three to six fourth-order high frequency sequences respectively in the studied sections.

Obsidian deposits in the central Balkans? Tested against archaeological evidence

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Tripković Boban

2003-01-01

Full Text Available Finds of obsidian artefacts on sites distant from the presumed primary source have often received a romantic note in the history of archaeology manifested in the idea about local exploitation as a form of procurement and archaeologists’ search for as yet undetected deposits of this raw material. In due course, such concepts have found their way into Serbian archaeology as well. The main objective of this contribution, therefore, is to reconsider the current knowledge about obsidian in the central and north Balkans, to test how well founded the idea about the use of local sources is, as well as to indicate some possible directions for future research.

Petrogenesis and depositional history of felsic pyroclastic rocks from the Melka Wakena archaeological site-complex in South central Ethiopia

Science.gov (United States)

Resom, Angesom; Asrat, Asfawossen; Gossa, Tegenu; Hovers, Erella

2018-06-01

The Melka Wakena archaeological site-complex is located at the eastern rift margin of the central sector of the Main Ethiopian Rift (MER), in south central Ethiopia. This wide, gently sloping rift shoulder, locally called the "Gadeb plain" is underlain by a succession of primary pyroclastic deposits and intercalated fluvial sediments as well as reworked volcaniclastic rocks, the top part of which is exposed by the Wabe River in the Melka Wakena area. Recent archaeological survey and excavations at this site revealed important paleoanthropological records. An integrated stratigraphic, petrological, and major and trace element geochemical study has been conducted to constrain the petrogenesis of the primary pyroclastic deposits and the depositional history of the sequence. The results revealed that the Melka Wakena pyroclastic deposits are a suite of mildly alkaline, rhyolitic pantellerites (ash falls, pumiceous ash falls and ignimbrites) and slightly dacitic ash flows. These rocks were deposited by episodic volcanic eruptions during early to middle Pleistocene from large calderas along the Wonji Fault Belt (WFB) in the central sector of the MER and from large silicic volcanic centers at the eastern rift shoulder. The rhyolitic ash falls, pumiceous ash falls and ignimbrites have been generated by fractional crystallization of a differentiating basaltic magma while the petrogenesis of the slightly dacitic ash flows involved some crustal contamination and assimilation during fractionation. Contemporaneous fluvial activities in the geomorphologically active Gadeb plain deposited overbank sedimentary sequences (archaeology bearing conglomerates and sands) along meandering river courses while a dense network of channels and streams have subsequently down-cut through the older volcanic and sedimentary sequences, redepositing the reworked volcaniclastic sediments further downstream.

Dzhezkazgan and associated sandstone copper deposits of the Chu-Sarysu basin, Central Kazakhstan

Science.gov (United States)

Box, Stephen E.; Seltmann, Reimar; Zientek, Michael L.; Syusyura, Boris; Creaser, Robert A.; Dolgopolova, Alla

2012-01-01

Sandstone-hosted copper (sandstone Cu) deposits occur within a 200-km reach of the northern Chu-Sarysu basin of central Kazakhstan (Dzhezkazgan and Zhaman-Aibat deposits, and the Zhilandy group of deposits). The deposits consist of Cu sulfide minerals as intergranular cement and grain replacement in 10 ore-bearing members of sandstone and conglomerate within a 600- to 1,000-m thick Pennsylvanian fluvial red-bed sequence. Copper metal content of the deposits ranges from 22 million metric tons (Mt, Dzehzkazgan) to 0.13Mt (Karashoshak in the Zhilandy group), with average grades of 0.85 to 1.7% Cu and significant values for silver (Ag) and rhenium (Re). Broader zones of iron reduction (bleaching) of sandstones and conglomerates of the red-bed sequence extend over 10 km beyond each of the deposits along E-NE-trending anticlines, which began to form in the Pennsylvanian. The bleached zones and organic residues within them are remnants of ormer petroleum fluid accumulations trapped by these anticlines. Deposit sites along these F1anticlines are localized at and adjacent to the intersections of nearly orthogonal N-NW-trending F2synclines. These structural lows served to guide the flow of dense ore brines across the petroleum-bearing anticlines, resulting in ore sulfide precipitation where the two fluids mixed. The ore brine was sourced either from the overlying Early Permian lacustrine evaporitic basin, whose depocenter occurs between the major deposits, or from underlying Upper Devonian marine evaporites. Sulfur isotopes indicate biologic reduction of sulfate but do not resolve whether the sulfate was contributed from the brine or from the petroleum fluids. New Re-Os age dates of Cu sulfides from the Dzhezkazgan deposit indicate that mineralization took place between 299 to 309 Ma near the Pennsylvanian-Permian age boundary. At the Dzhezkazgan and some Zhilandy deposits, F2fold deformation continued after ore deposition. Copper orebodies in Lower Permian

Annular and central heavy pigment deposition on the posterior lens capsule in the pigment dispersion syndrome: pigment deposition on the posterior lens capsule in the pigment dispersion syndrome.

Science.gov (United States)

Turgut, Burak; Türkçüoğlu, Peykan; Deniz, Nurettin; Catak, Onur

2008-12-01

To report annular and central heavy pigment deposition on the posterior lens capsule in a case of pigment dispersion syndrome. Case report. A 36-year-old female with bilateral pigment dispersion syndrome presented with progressive decrease in visual acuity in the right eye over the past 1-2 years. Clinical examination revealed the typical findings of pigment dispersion syndrome including bilateral Krunkenberg spindles, iris transillumination defects, and dense trabecular meshwork pigmentation. Remarkably, annular and central dense pigmentation of the posterior lens capsule was noted in the right eye. Annular pigment deposition on the posterior lens capsule may be a rare finding associated with pigment dispersion syndrome. Such a finding suggests that there may be aqueous flow into the retrolental space in some patients with this condition. The way of central pigmentation is the entrance of aqueous to Berger's space. In our case, it is probable that spontaneous detachment of the anterior hyaloid membrane aided this entrance.

Characteristics of Wet Deposition in Japan

Science.gov (United States)

Iwasaki, A.; Arakaki, T.

2017-12-01

Acid deposition survey in Japan has started since 1991 by Japan Environmental Laboratories Association (JELA). The JELA has about 60 monitoring sites for wet deposition including remote, rural and urban area. The measured constituents of wet deposition are; precipitation, pH, electric conductivity, major Anions, and major Cations. From those data, we analyze spatial and temporal variations of wet deposition components in Japan. Among the 60 monitoring sites, 39 sampling sites were selected in this study, which have kept sampling continuously between 2003JFY and 2014JFY. All samples were collected by wet-only samplers. To analyze area characteristics, all the areas were divided into 6 regions; Northern part of Japan (NJ), Facing the Japan Sea (JS), Eastern part of Japan (EJ), Central part of Japan (CJ), Western part of Japan (WJ) and Southern West Islands (SW). NO3- and non-sea-salt-SO42- (nss-SO42-) are major components of rain acidification. Especially, between December and February (winter) the air mass from west affected the temporal variations of those acid components and the concentrations were higher in JS and WJ regions than those in other regions. Japanese ministry of the Environment reported that mixing ratio of NO2 in Japan has been less than 0.04ppm since 1976, and that of SO2 has been less than 0.02ppm since 1978. Their concentrations in Japan have remained flat or slowly decreased recently. However the temporal variations of NO3-/nss-SO42- ratio in winter in JS region were significantly increased on average at 2.2% y-1 from 2003JFY to 2014JFY. The results suggest that long-range transboundary air pollutants increased NO3- concentrations and NO3-/nss-SO42- ratio.

The role of catastrophic geomorphic events in central Appalachian landscape evolution

Science.gov (United States)

Jacobson, R.B.; Miller, A.J.; Smith, J.A.

1989-01-01

Catastrophic geomorphic events are taken as those that are large, sudden, and rare on human timescales. In the nonglaciated, low-seismicity central Appalachians, these are dominantly floods and landslides. Evaluation of the role of catastrophic events in landscape evolution includes assessment of their contributions to denudation and formation of prominent landscape features, and how they vary through space and time. Tropical storm paths and topographic barriers at the Blue Ridge and Allegheny Front create significant climatic variability across the Appalachians. For moderate floods, the influence of basin geology is apparent in modifying severity of flooding, but for the most extreme events, flood discharges relate mainly to rainfall characteristics such as intensity, duration, storm size, and location. Landslide susceptibility relates more directly to geologic controls that determine what intensity and duration of rainfall will trigger slope instability. Large floods and landslides are not necessarily effective in producing prominent geomorphic features. Large historic floods in the Piedmont have been minimally effective in producing prominent and persistent geomorphic features. In contrast, smaller floods in the Valley and Ridge produced erosional and depositional features that probably will require thousands of years to efface. Scars and deposits of debris slide-avalanches triggered on sandstone ridges recover slowly and persist much longer than scars and deposits of smaller landslides triggered on finer-grained regolith, even though the smaller landslides may have eroded greater aggregate volume. The surficial stratigraphic record can be used to extend the spatial and temporal limits of our knowledge of catastrophic events. Many prominent alluvial and colluvial landforms in the central Appalachians are composed of sediments that were deposited by processes similar to those observed in historic catastrophic events. Available stratigraphic evidence shows two

Perturbation methods and the Melnikov functions for slowly varying oscillators

International Nuclear Information System (INIS)

Lakrad, Faouzi; Charafi, Moulay Mustapha

2005-01-01

A new approach to obtaining the Melnikov function for homoclinic orbits in slowly varying oscillators is proposed. The present method applies the Lindstedt-Poincare method to determine an approximation of homoclinic solutions. It is shown that the resultant Melnikov condition is the same as that obtained in the usual way involving distance functions in three dimensions by Wiggins and Holmes [Homoclinic orbits in slowly varying oscillators. SIAM J Math Anal 1987;18(3):612

Thin accretion disk signatures of slowly rotating black holes in Horava gravity

International Nuclear Information System (INIS)

Harko, Tiberiu; Kovacs, Zoltan; Lobo, Francisco S N

2011-01-01

In this work, we consider the possibility of observationally testing Horava gravity by using the accretion disk properties around slowly rotating black holes of the Kehagias-Sfetsos (KS) solution in asymptotically flat spacetimes. The energy flux, temperature distribution, the emission spectrum as well as the energy conversion efficiency are obtained, and compared to the standard slowly rotating general relativistic Kerr solution. Comparing the mass accretion in a slowly rotating KS geometry in Horava gravity with the one of a slowly rotating Kerr black hole, we verify that the intensity of the flux emerging from the disk surface is greater for the slowly rotating Kehagias-Sfetsos solution than for rotating black holes with the same geometrical mass and accretion rate. We also present the conversion efficiency of the accreting mass into radiation, and show that the rotating KS solution provides a much more efficient engine for the transformation of the accreting mass into radiation than the Kerr black holes. Thus, distinct signatures appear in the electromagnetic spectrum, leading to the possibility of directly testing Horava gravity models by using astrophysical observations of the emission spectra from accretion disks.

Thin accretion disk signatures of slowly rotating black holes in Horava gravity

Energy Technology Data Exchange (ETDEWEB)

Harko, Tiberiu; Kovacs, Zoltan [Department of Physics and Center for Theoretical and Computational Physics, University of Hong Kong, Pok Fu Lam Road (Hong Kong); Lobo, Francisco S N, E-mail: harko@hkucc.hku.hk, E-mail: zkovacs@hku.hk, E-mail: flobo@cii.fc.ul.pt [Centro de Astronomia e Astrofisica da Universidade de Lisboa, Campo Grande, Ed. C8 1749-016 Lisboa (Portugal)

2011-08-21

In this work, we consider the possibility of observationally testing Horava gravity by using the accretion disk properties around slowly rotating black holes of the Kehagias-Sfetsos (KS) solution in asymptotically flat spacetimes. The energy flux, temperature distribution, the emission spectrum as well as the energy conversion efficiency are obtained, and compared to the standard slowly rotating general relativistic Kerr solution. Comparing the mass accretion in a slowly rotating KS geometry in Horava gravity with the one of a slowly rotating Kerr black hole, we verify that the intensity of the flux emerging from the disk surface is greater for the slowly rotating Kehagias-Sfetsos solution than for rotating black holes with the same geometrical mass and accretion rate. We also present the conversion efficiency of the accreting mass into radiation, and show that the rotating KS solution provides a much more efficient engine for the transformation of the accreting mass into radiation than the Kerr black holes. Thus, distinct signatures appear in the electromagnetic spectrum, leading to the possibility of directly testing Horava gravity models by using astrophysical observations of the emission spectra from accretion disks.

Depositional facies mosaics and their time lines in Lower Ordovician carbonates of central Appalachians

Energy Technology Data Exchange (ETDEWEB)

Nguyen, C.T.; Goldhammer, R.K.; Hardie, L.A.

1985-02-01

A comparative sedimentology and facies stratigraphy study of the Lower Ordovician carbonate of the central Appalachians (Beekmantown Group and equivalents) has been carried out. Our approach used subfacies (rock record of subenvironments) as the basin units of section measurement. The authors differentiated related sets of subfacies into larger facies units (rock record of environments). Facies were then correlated from section to section using fossils and lithostratigraphy to make a 3-dimensional facies mosaic. Within this mosaic, time lines were constructed using onlap-offlap tongues and cyclic sequences. These time lines cut across facies boundaries. Using this approach, the authors have established that the lower 600 m of the Lower Ordovician carbonate sequence is made up of 4 main facies: (1) cyclic laminite facies composed of a package of shoaling-upward shelf lagoon-peritidal cycles, (2) thin-bedded grainstone facies deposited in a shelf lagoon, (3) Renalcis bioherm facies recording a shelf lagoon patch-reef environment, and (4) Epiphyton bioherm facies recording a shelf-edge reef system. The distribution of these facies along time lines across the strike of the central Appalachians is markedly zoned. Epiphyton bioherm facies dominate the eastern margin while cyclic laminite facies dominate the western margin, with thin-bedded grainstone and Renalcis bioherm facies making up the central belt. This zonation of facies is a typical shallow carbonate shelf system with fringing reefs along the eastern, seaward margin and tidal flats along the western, landward margin. Vertical distribution of these facies across strike records 3 major sea level changes during deposition of the lower 600 m of this extensive Lower Ordovician carbonate shelf.

REVIEW OF COASTAL CHARACTERISTICS OF IRON SAND DEPOSITS IN CILACAP CENTRAL JAVA

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Hananto Kurnio

2017-07-01

Full Text Available Mineable iron sand deposits in Cilacap – southern coastal area of Central Java have certain coastal characteristics that need to be studied in order to understand its depositional environment. With the knowledge of such environment, it can be applied to look for other places prospective of iron sand deposits that have the same characteristics especially recently when Cilacap’s deposits were almost depleted. Coastal characteristics of iron sand deposit in Cilacap is shown by successive sandy beach ridges separated by marshy valleys typical of prograded coasts and by dunes of sand elongated parallel to the shore line with elevation varies from 0 m to 15 m above sea level. The iron sand deposit was derived from denudation of andesite and “Old Andesite Formation” enriched in magnetite and ilmenite minerals in the steep elevated and deeply weathered rock hinterlands of Cilacap. High sediment loads of Serayu Basin in the hinterland (3,500-4,500 ton/km2/year; Citarum River basin only 800-1,200 ton/km2/year was causing extensive deposition of iron sand in the coastal zone. Key words: coast, characteristic, iron sand, Cilacap Endapan pasir besi yang dapat ditambang di Cilacap – pesisir selatan Jawa Tengah memiliki karakteristik pantai tertentu yang perlu dikaji agar dapat dipahami lingkungan pengendapannya. Dengan pengetahuan tentang lingkungan pengendapan tersebut, dapat diterapkan untuk mencari daerah-daerah lain prospek endapan pasir besi yang memiliki karakteristik yang sama terutama pada akhir-akhir ini ketika endapan Cilacap akan habis. Karakteristik pantai endapan pasir besi di Cilacap dicirikan oleh urutan pematang pantai berpasir yang dipisahkan oleh lembah-lembah berawa khas pantai maju dan oleh gumuk-gumuk pasir memanjang sejajar dengan garis pantai dengan ketinggian bervariasi dari 0 m hingga 15 m dari muka laut. Endapan pasir besi di daerah ini berasal dari proses denudasi andesit dan “Formasi Andesit

Exploration potential of the Eocene deposits in central Romanian block sea off shore

International Nuclear Information System (INIS)

Tambrea, D; Raileanu, A; Barbuliceanu, N; Borosi, V.

2002-01-01

Full text:The study area comprises the Eocene Istria Depression bounded by Peceneaga- Camena and Heracleea faults, in front of North Dobrogea Orogene and Central Dobrogea, in the Romanian Black Sea offshore. The analysis of 100 two- dimensional (2D) seismic lines and two- three dimensional (3D) seismic surveys and well data has permitted to outline that the geo dynamic evolution of Eocene basins has led to the deposition of carbonate- sliciclastic turbidity, porous carbonate shelf margin reservoir deposits, and muddy carbonate turbiditic source rocks that present new Eocene petroleum targets. The main Eocene sub basin located in Iris-Venus area is deep, rhombic shaped, del imitated by normal faults, and may be connected with the strike-slip deformation component of Peceneaga- Camena fault. The next sub basin, located on West Lebeda area may be considered a cross- fault extensional zone. In the following sub basin East Lebada- Minerva area, normal faults generated a tectonic corridor characterized by high subsidence rate and local submarine/sub aerial intra slope topographic high. The last sub basin localized in Histria is a ponded one and captured highly organic matter rich muddly carbonate turgidities. In all sub basins, there is a progression from structure control to sediment control deposition

Hydrothermal uranium deposits containing molybdenum and fluorite in the Marysvale volcanic field, west-central Utah

Science.gov (United States)

Cunningham, C.G.; Rasmussen, J.D.; Steven, T.A.; Rye, R.O.; Rowley, P.D.; Romberger, S.B.; Selverstone, J.

1998-01-01

Uranium deposits containing molybdenum and fluorite occur in the Central Mining Area, near Marysvale, Utah, and formed in an epithermal vein system that is part of a volcanic/hypabyssal complex. They represent a known, but uncommon, type of deposit; relative to other commonly described volcanic-related uranium deposits, they are young, well-exposed and well-documented. Hydrothermal uranium-bearing quartz and fluorite veins are exposed over a 300 m vertical range in the mines. Molybdenum, as jordisite (amorphous MoS2, together with fluorite and pyrite, increase with depth, and uranium decreases with depth. The veins cut 23-Ma quartz monzonite, 20-Ma granite, and 19-Ma rhyolite ash-flow tuff. The veins formed at 19-18 Ma in a 1 km2 area, above a cupola of a composite, recurrent, magma chamber at least 24 ?? 5 km across that fed a sequence of 21- to 14-Ma hypabyssal granitic stocks, rhyolite lava flows, ash-flow tuffs, and volcanic domes. Formation of the Central Mining Area began when the intrusion of a rhyolite stock, and related molybdenite-bearing, uranium-rich, glassy rhyolite dikes, lifted the fractured roof above the stock. A breccia pipe formed and relieved magmatic pressures, and as blocks of the fractured roof began to settle back in place, flat-lying, concave-downward, 'pull-apart' fractures were formed. Uranium-bearing, quartz and fluorite veins were deposited by a shallow hydrothermal system in the disarticulated carapace. The veins, which filled open spaces along the high-angle fault zones and flat-lying fractures, were deposited within 115 m of the ground surface above the concealed rhyolite stock. Hydrothermal fluids with temperatures near 200??C, ??18OH2O ~ -1.5, ?? -1.5, ??DH2O ~ -130, log fO2 about -47 to -50, and pH about 6 to 7, permeated the fractured rocks; these fluids were rich in fluorine, molybdenum, potassium, and hydrogen sulfide, and contained uranium as fluoride complexes. The hydrothermal fluids reacted with the wallrock resulting in

GIS-based identification of areas with mineral resource potential for six selected deposit groups, Bureau of Land Management Central Yukon Planning Area, Alaska

Science.gov (United States)

Jones, James V.; Karl, Susan M.; Labay, Keith A.; Shew, Nora B.; Granitto, Matthew; Hayes, Timothy S.; Mauk, Jeffrey L.; Schmidt, Jeanine M.; Todd, Erin; Wang, Bronwen; Werdon, Melanie B.; Yager, Douglas B.

2015-01-01

This study, covering the Bureau of Land Management (BLM) Central Yukon Planning Area (CYPA), Alaska, was prepared to aid BLM mineral resource management planning. Estimated mineral resource potential and certainty are mapped for six selected mineral deposit groups: (1) rare earth element (REE) deposits associated with peralkaline to carbonatitic intrusive igneous rocks, (2) placer and paleoplacer gold, (3) platinum group element (PGE) deposits associated with mafic and ultramafic intrusive igneous rocks, (4) carbonate-hosted copper deposits, (5) sandstone uranium deposits, and (6) tin-tungsten-molybdenum-fluorspar deposits associated with specialized granites. These six deposit groups include most of the strategic and critical elements of greatest interest in current exploration.

Properties of indium tin oxide films deposited on unheated polymer substrates by ion beam assisted deposition

International Nuclear Information System (INIS)

Yu Zhinong; Li Yuqiong; Xia Fan; Zhao Zhiwei; Xue Wei

2009-01-01

The optical, electrical and mechanical properties of indium tin oxide (ITO) films prepared on polyethylene terephthalate (PET) substrates by ion beam assisted deposition at room temperature were investigated. The properties of ITO films can be improved by introducing a buffer layer of silicon dioxide (SiO 2 ) between the ITO film and the PET substrate. ITO films deposited on SiO 2 -coated PET have better crystallinity, lower electrical resistivity, and improved resistance stability under bending than those deposited on bare PET. The average transmittance and the resistivity of ITO films deposited on SiO 2 -coated PET are 85% and 0.90 x 10 -3 Ω cm, respectively, and when the films are bent, the resistance remains almost constant until a bending radius of 1 cm and it increases slowly under a given bending radius with an increase of the bending cycles. The improved resistance stability of ITO films deposited on SiO 2 -coated PET is mainly attributed to the perfect adhesion of ITO films induced by the SiO 2 buffer layer.

Gravel size matters: Early Middle Palaeolithic artefacts made from local Rhine and Meuse deposits in the central Netherlands

NARCIS (Netherlands)

van den Biggelaar, D.F.A.M.; van Balen, R.T.; Kluiving, S.J.; Verpoorte, A.; Alink, A

2016-01-01

The artefact size of the Early Middle Palaeolithic (EMP) assemblages in ice-pushed Rhine–Meuse deposits in the central Netherlands decreases northwestward. This trend correlates to the downstream fining direction of the Rhine–Meuse fluvial system, the source of the rock material, showing that

Testing optically stimulated luminescence dating on sand-sized quartz of deltaic deposits from the Sperchios delta plain, central Greece

Directory of Open Access Journals (Sweden)

Evangelos Tsakalos

2018-04-01

Full Text Available This study reports on the first investigation into the potential of luminescence dating to establish a chronological framework for the depositional sequences of the Sperchios delta plain, central Greece. A series of three borehole cores (20 m deep and two shallow cores (4 m deep, from across the delta plain, were extracted, and samples were collected for luminescence dating. The luminescence ages of sand-sized quartz grains were obtained from small aliquots of quartz, using the Single-Aliquot Regenerative-dose (SAR protocol. The equivalent dose determination included a series of tests and the selection of the Minimum Age Model (MAM as the most appropriate statistical model. This made it possible to confirm the applicability of quartz Optically Stimulated Luminescence (OSL dating to establish absolute chronology for deltaic sediments from the Sperchios delta plain.Testing age results of the five cores showed that the deltaic sediments were deposited during the Holocene. A relatively rapid deposition is implied for the top ∼14 m possibly as a result of the deceleration in the rate of the sea-level rise and the transition to terrestrial conditions, while on the deeper parts, the reduced sedimentation rate may indicate a lagoonal or coastal environment. Keywords: Luminescence dating, Holocene, Sedimentation rates, Deltaic deposits, Sperchios delta plain, Central Greece

Patterns of seabird and marine mammal carcass deposition along the central California coast, 1980-1986

Science.gov (United States)

Bodkin, James L.; Jameson, Ronald J.

1991-01-01

At monthly intervals from February 1980 through December 1986, a 14.5-km section of central California coastline was systematically surveyed for beach-cast carcasses of marine birds and mammals. Five hundred and fifty-four bird carcasses and 194 marine mammal carcasses were found. Common murres, western grebes, and Brandt's cormorants composed 45% of the bird total. California sea lions, sea otters, and harbor seals composed 90% of the mammal total. Several factors appeared to affect patterns of carcass deposition. The El Niño – Southern Oscillation (ENSO) of 1982–1983 was the dominant influence in terms of interannual variation in carcass deposition. During this ENSO, 56% of the seabirds and 48% of the marine mammals washed ashore. Patterns of intra-annual variation were species specific and were related to animal migration patterns, reproduction, and seasonal changes in weather. Nearshore currents and winds influenced the general area of carcass deposition, while beach substrate type and local patterns of sand deposition influenced the location of carcass deposition on a smaller spatial scale. Weekly surveys along a 1.1-km section of coastline indicated that 62% of bird carcasses and 41% of mammal carcasses remained on the beach less than 9 days. Cause of death was determined for only 8% of the carcasses. Oiling was the most common indication of cause of death in birds (6%). Neonates composed 8% of all mammal carcasses.

Midwifery education in Central-Eastern Europe.

Science.gov (United States)

Mivšek, Polona; Baškova, Martina; Wilhelmova, Radka

2016-02-01

Problems in midwifery in many Central-Eastern European countries are very similar; it is possible to speak about the evolving Central-Eastern model of midwifery care. The educational models of this region have a relatively strong theoretical part; however, there is an insufficient practical dimension. Theoretical part of midwifery education in the universities is relatively autonomous and is slowly changing the professional identity of graduates. Copyright © 2015 Elsevier Ltd. All rights reserved.

Nutrient stoichiometry in Sphagnum along a nitrogen deposition gradient in highly polluted region of Central-East Europe.

Science.gov (United States)

Jiroušek, Martin; Hájek, Michal; Bragazza, Luca

2011-02-01

We investigated the variation of N:P and N:K ratio in ombrotrophic Sphagnum plants along a gradient of atmospheric N deposition from 1 to 2.5 g m(-2) year(-1) in Central-East Europe. The N:P and N:K ratio in Sphagnum capitula increased significantly along the N deposition gradient. Sphagnum species from the Cuspidata section were characterised by significantly lower ratios at low N deposition. When we compared the observed N:P ratios in Sphagnum plants with the values reported in a previous European-wide study, we found a correspondence in nutrient stoichiometry only for a few bogs: higher P concentration in Sphagnum capitula caused a lower N:P ratio in most of the study bogs so that Sphagnum plants still seem N-limited despite their N saturation. Interaction between summer water table decrease and aerial liming of surrounding forests is proposed as an explanation for this discrepancy. Local forestry practice interacting with climate thus alter N:P stoichiometry of Sphagnum along the N deposition gradient. Copyright © 2010 Elsevier Ltd. All rights reserved.

Quintinite-1 M from the Mariinsky Deposit, Ural Emerald Mines, Central Urals, Russia

Science.gov (United States)

Zhitova, E. S.; Popov, M. P.; Krivovichev, S. V.; Zaitsev, A. N.; Vlasenko, N. S.

2017-12-01

The paper describes the first finding of quintinite [Mg4Al2(OH)12][(CO3)(H2O)3] at the Mariinsky deposit in the Central Urals, Russia. The mineral occurs as white tabular crystals in cavities within altered gabbro in association with prehnite, calcite, and a chlorite-group mineral. Quintinite is the probable result of late hydrothermal alteration of primary mafic and ultramafic rocks hosting emerald-bearing glimmerite. According to electron microprobe data, the Mg: Al ratio is 2: 1. IR spectroscopy has revealed hydroxyl and carbonate groups and H2O molecules in the mineral. According to single crystal XRD data, quintinite is monoclinic, space group C2/ m, a =5.233(1), b = 9.051(2), c = 7.711(2) Å, β = 103.09(3)°, V = 355.7(2) Å3. Based on structure refinement, the polytype of quintinite should be denoted as 1M. This is the third approved occurrence of quintinite-1M in the world after the Kovdor complex and Bazhenovsky chrysotile-asbestos deposit.

The Neogene molasse deposits of the Zagros Mountains in central Dezful Embayment: facies, sedimentary environments and controls

Directory of Open Access Journals (Sweden)

Ali Hossein Jalilian

2016-03-01

Full Text Available The upper part of Neogene sequence of the Zagros Mountains consists of a clastic succession which is identified as Aghajari and Bakhtyari formations. The sequence is an excellent example of synorogenic sedimentation or molasse deposited in northern portion of the Zagros foreland basin. Sedimentological analysis of an outcrop section representing Miocene-Pliocene sediments in central Dezful Embayment resulted in recognizing 9 lithofacies and 4 architectural elements. These lithofacies include conglometate (Gt, Gh, Gmm, sandstone (Sp, Sh, Sr, St and mudstone (Fm, Fl that were deposited in meandering stream, braided river and alluvial fan environments. Paleocurrent analysis of cross-beds, channels and asymmetric ripple marks indicate that these Neogene clastics were mainly drived from Cretaceous to Paleogene highlands in the Zagros Mountains on the north. This stratigraphic record is coarsening-upward and formed by a regressive depositional megacycle under arid climate. Facies and depositional history analysis show that sedimentation of the Zagros molasse was primarily controlled by base-level changes rather than catchment lithology or climate. The sedimentary record of this regressive megacycle reveales the base-level was constantly falling down on one hand and the provenance was uplifting on the other hand. Tectonic activities and Zagros Mountains rising in the Late Miocene resulted in deposition of fining-upward point-bar and floodplain sequences of the Aghajari Formation in low-gradient meandering streams. The Lahbari Member of the Aghajari Formation represents deposition in braided rivers that composed predominantly of flood-plain deposits in the Early Pliocene. Finally, the sedimentary cycle of the Zagros molasse deposits terminated with massive conglomerates of the Bakhtyari Formation deposited in large alluvial fans near the source area.

Early colonization of thermal niches in a silica-depositing hot spring in central Tibet.

Science.gov (United States)

Lau, C Y; Aitchison, J C; Pointing, S B

2008-03-01

Thermophilic microbial mats dominated by the anoxygenic phototroph Roseiflexus castenholzii commonly develop around sinter-depositing geysers in the Daggyai Tso geothermal field of central Tibet. In this study we used morphological and molecular genetic techniques to reveal a diverse pioneer biofilm community including both archaea and bacteria involved in early colonization of such thermal niches at temperatures ranging from 46 to 77 degrees C. Sinter precipitation and biomineralization were evident at all locations, but the latter was selective between taxa and most evident on filamentous cells. Evidence for possible indirect biosignatures from biofilms overwhelmed by sinter deposition was found. Succession to a mature community appeared to relate to the growth rate for key taxa outpacing that of silicification within an optimum temperature range of 54-61 degrees C. The thin surface layer of silicification-resistant cyanobacteria that developed on the surface of mature mats may play a role in preventing biomineralization of the susceptible R. castenholzii beneath within these communities.

Data on nearshore wave process and surficial beach deposits, central Tamil Nadu coast, India.

Science.gov (United States)

Joevivek, V; Chandrasekar, N

2017-08-01

The chronicles of nearshore morphology and surficial beach deposits provide valuable information about the nature of the beach condition and the depositional environment. It imparts an understanding about the spatial and temporal relationship of nearshore waves and its influence over the distribution of beach sediments. This article contains data about wave and sediment dynamics of the ten sandy beaches along the central Tamil Nadu coast, India. This present dataset comprises nearshore wave parameters, breaker wave type, beach morphodynamic state, grain size distribution and weight percentage of heavy and light mineral distribution. The dataset will figure out the beach morphology and hydrodynamic condition with respect to the different monsoonal season. This will act as a field reference to realize the coastal dynamics in an open sea condition. The nearshore entities were obtained from the intensive field survey between January 2011 and December 2011, while characteristics of beach sediments are examined by the chemical process in the laboratory environment.

Uranium deposits in the Eureka Gulch area, Central City district, Gilpin County, Colorado

Science.gov (United States)

Sims, P.K.; Osterwald, F.W.; Tooker, E.W.

1954-01-01

The Eureka Gulch area of the Central City district, Gilpin County, Colo., was mined for ores of gold, silver, copper, lead, and zinc; but there has been little mining activity in the area since World War I. Between 1951 and 1953 nine radioactive mine dumps were discovered in the area by the U.S. Geological Survey and by prospectors. the importance of the discoveries has not been determined as all but one of the mines are inaccessible, but the distribution, quantity, and grade of the radioactive materials found on the mine dumps indicate that the area is worth of additional exploration as a possible source of uranium ore. The uranium ans other metals are in and near steeply dipping mesothermal veins of Laramide age intrusive rocks. Pitchblende is present in at least four veins, and metatorbernite, associated at places with kosolite, is found along two veins for a linear distance of about 700 feet. The pitchblends and metatorbernite appear to be mutually exclusive and seem to occur in different veins. Colloform grains of pitchblende were deposited in the vein essentially contemporaneously with pyrite. The pitchblende is earlier in the sequence of deposition than galena and sphalerite. The metatorbernite replaces altered biotite-quartz-plagioclase gneiss and altered amphibolite, and to a lesser extent forms coatings on fractures in these rocks adjacent to the veins; the kasolite fills vugs in highly altered material and in altered wall rocks. Much of the pitchblende found on the dumps has been partly leached subsequent to mining and is out of equilibrium. Selected samples of metatorbernite-bearing rock from one mine dump contain as much as 6.11 percent uranium. The pitchblende is a primary vein mineral deposited from uranium-bearing hydrothermal solutions. The metatorbernite probably formed by oxidation, solution, and transportation of uranium from primary pitchblende, but it may be a primary mineral deposited directly from fluids of different composition from these

Clinical and radiological aspects of limited forms of infiltrative pulmonary tuberculosis and slowly resolving pneumonia

International Nuclear Information System (INIS)

Caraiani, Olga; Lesnic, Evelina; Niguleanu, Adriana; Niguleanu, Radu

2016-01-01

Despite of a clearly defined diagnostic algorithm of pulmonary tuberculosis, low sensibility of contemporary laboratory methods in limited forms of pulmonary tuberculosis contributes to a difficult differential diagnosis with community acquired pneumonia, especially with slowly resolving pneumonia. A case-control, prospective, selective, comparative and descriptive study was performed using a group of 180 patients, divided into two samples: I group - 125 cases with limited form of pulmonary infiltrative tuberculosis; II group - 55 cases with slowly resolving community-acquired pneumonia. The findings identified the prevalence of intoxication syndrome in the slowly resolving pneumonia sample. Lung destructions and bronchogenous dissemination was identified only in the tuberculosis sample. A higher impact of comorbidities and old age was more relevant in slowly resolving pneumonia sample. Clinical and radiological improvement was established in most patients of both groups, but the considerable resorption of lung infiltrates predominated in slowly resolving pneumonia sample. (authors)

Soliton-effect generation of Raman pulses in optical fibers with slowly decreasing dispersion

International Nuclear Information System (INIS)

Wenhua Cao; Youwei Zhang

1995-01-01

We suggested that single-mode fibers with slowly decreasing dispersion (FSDD) should be used for the generation of tunable ultrashort RAman pulses. A mathematical model is obtained for the description of ultrafast stimulated Raman scattering in optical fibers with slowly decreasing dispersion. Numerical simulations show that, under identical pump conditions, Raman pulse generated from this kind of fiber is shorter with a higher peak power than that generated from conventional fibers. This means that the Raman threshold of fibers with slowly decreasing dispersion may be lower than that of conventional fibers. Given pump conditions, we found that the highest peak power and narrowest width of the Raman pulse correspond to an optimal decrement velocity of the fiber dispersion

Some aspects on the variations in depositional flux of excess Thorium-230 in the central Indian basin during Late Quaternary

Digital Repository Service at National Institute of Oceanography (India)

Sukumaran, N.P.

Examined in this paper is the tentative history of the depositional flux of @u230@@Th@dxs@@ (the unsupported fraction of @u230@@Th scavenged from the overlying water column), for the Late Quaternary period from a sediment core of the Central Indian...

Geophysical prospecting for iron ore deposit around Tajimi village, Lokoja, North–Central Nigeria

Directory of Open Access Journals (Sweden)

Bayowa Oyelowo

2016-09-01

Full Text Available Ground magnetic and electrical resistivity survey were undertaken to investigate the occurrence and geometry of iron ore deposit around Tajimi village, Lokoja, North-Central Nigeria. The generated residual map of the ground-magnetic data acquired at 250 stations along 15 traverses revealed numerous prominent anomalies, mostly trending in the N-S direction. The radial power spectrum revealed the depth to magnetic sources between 6 m to 20 m. The interpreted VES data characterized the area into three subsurface layers: top soil, presumably iron ore layer and weathered/fresh basement. The result of vertical electrical sounding curves showed a sudden drop in resistivity (42-241 Ωm over high magnetic response. The geo-electric section revealed that the study area is generally characterized with thin overburden (0.5-1.7 m and the thickness of the second layer (presumed to be the iron ore layer ranged between 6.2-25.1 m. The study concluded that areas of high magnetic intensity showed a sudden drop in resistivity value for the VES points, which give an indication of the presence of an electrically conductive structure presumed to be iron ore deposits.

Atmospheric deposition of beryllium in Central Europe: comparison of soluble and insoluble fractions in rime and snow across a pollution gradient.

Science.gov (United States)

Bohdalkova, Leona; Novak, Martin; Voldrichova, Petra; Prechova, Eva; Veselovsky, Frantisek; Erbanova, Lucie; Krachler, Michael; Komarek, Arnost; Mikova, Jitka

2012-11-15

Little is known about atmospheric input of beryllium (Be) into ecosystems, despite its highly toxic behavior. For three consecutive winters (2009-2011), we measured Be concentrations in horizontal deposition (rime) and vertical deposition (snow) at 10 remote mountain-top locations in the Czech Republic, Central Europe. Beryllium was determined both in filtered waters, and in HF digests of insoluble particles. Across the sites, soluble Be concentrations in rime were 7 times higher, compared to snow (6.1 vs. 0.9ng·L(-1)). Rime scavenged the pollution-rich lower segments of clouds. The lowest Be concentrations were detected in the soluble fraction of snow. Across the sites, 34% of total Be deposition occurred in the form of soluble (bioavailable) Be, the rest were insoluble particles. Beryllium fluxes decreased in the order: vertical dry deposition insoluble>vertical dry deposition soluble>horizontal deposition soluble>vertical wet deposition insoluble>vertical wet deposition soluble>horizontal deposition insoluble. The average contributions of these Be forms to total deposition were 56, 21, 8, 7, 5 and 3%, respectively. Sites in the northeast were more Be-polluted than the rest of the country with sources of pollution in industrial Silesia. Copyright © 2012 Elsevier B.V. All rights reserved.

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

Controllable chemical vapor deposition of large area uniform nanocrystalline graphene directly on silicon dioxide

DEFF Research Database (Denmark)

Sun, Jie; Lindvall, Niclas; Cole, Matthew T.

2012-01-01

Metal-catalyst-free chemical vapor deposition (CVD) of large area uniform nanocrystalline graphene on oxidized silicon substrates is demonstrated. The material grows slowly, allowing for thickness control down to monolayer graphene. The as-grown thin films are continuous with no observable pinholes...

Slowly Digestible Carbohydrate for Balanced Energy: In Vitro and In Vivo Evidence

Directory of Open Access Journals (Sweden)

Vishnupriya Gourineni

2017-11-01

Full Text Available There is growing interest among consumers in foods for sustained energy management, and an increasing number of ingredients are emerging to address this demand. The SUSTRA™ 2434 slowly digestible carbohydrate is a blend of tapioca flour and corn starch, with the potential to provide balanced energy after a meal. The aim of the study was to characterize this starch’s digestion profile in vitro (modified Englyst assay and in vivo (intact and cecectomized rooster study, and to determine its effects on available energy, by measuring post-prandial glycemia in healthy adults (n = 14, in a randomized, double-blind, placebo-controlled, cross-over study, with two food forms: cold-pressed bar and pudding. The in vitro starch digestion yielded a high slowly digestible fraction (51% compared to maltodextrin (9%. In the rooster digestibility model, the starch was highly digestible (94%. Consumption of slowly digestible starch (SDS, in an instant pudding or bar, yielded a significantly lower glycemic index compared to a control. At individual time points, the SDS bar and pudding yielded blood glucose levels with significantly lower values at 30–60 min and significantly higher values at 120–240 min, demonstrating a balanced energy release. This is the first study to comprehensively characterize the physiological responses to slowly digestible starch (tapioca and corn blend in in vitro and in vivo studies.

Slowly Digestible Carbohydrate for Balanced Energy: In Vitro and In Vivo Evidence

Science.gov (United States)

Gourineni, Vishnupriya; Stewart, Maria L.; Skorge, Rob; Sekula, Bernard C.

2017-01-01

There is growing interest among consumers in foods for sustained energy management, and an increasing number of ingredients are emerging to address this demand. The SUSTRA™ 2434 slowly digestible carbohydrate is a blend of tapioca flour and corn starch, with the potential to provide balanced energy after a meal. The aim of the study was to characterize this starch’s digestion profile in vitro (modified Englyst assay) and in vivo (intact and cecectomized rooster study), and to determine its effects on available energy, by measuring post-prandial glycemia in healthy adults (n = 14), in a randomized, double-blind, placebo-controlled, cross-over study, with two food forms: cold-pressed bar and pudding. The in vitro starch digestion yielded a high slowly digestible fraction (51%) compared to maltodextrin (9%). In the rooster digestibility model, the starch was highly digestible (94%). Consumption of slowly digestible starch (SDS), in an instant pudding or bar, yielded a significantly lower glycemic index compared to a control. At individual time points, the SDS bar and pudding yielded blood glucose levels with significantly lower values at 30–60 min and significantly higher values at 120–240 min, demonstrating a balanced energy release. This is the first study to comprehensively characterize the physiological responses to slowly digestible starch (tapioca and corn blend) in in vitro and in vivo studies. PMID:29125542

Seismic sequence stratigraphy and platform to basin reservoir structuring of Lower Cretaceous deposits in the Sidi Aïch-Majoura region (Central Tunisia)

Science.gov (United States)

Azaïez, Hajer; Bédir, Mourad; Tanfous, Dorra; Soussi, Mohamed

2007-05-01

In central Tunisia, Lower Cretaceous deposits represent carbonate and sandstone reservoir series that correspond to proven oil fields. The main problems for hydrocarbon exploration of these levels are their basin tectonic configuration and their sequence distribution in addition to the source rock availability. The Central Atlas of Tunisia is characterized by deep seated faults directed northeast-southwest, northwest-southeast and north-south. These faults limit inherited tectonic blocks and show intruded Triassic salt domes. Lower Cretaceous series outcropping in the region along the anticline flanks present platform deposits. The seismic interpretation has followed the Exxon methodologies in the 26th A.A.P.G. Memoir. The defined Lower Cretaceous seismic units were calibrated with petroleum well data and tied to stratigraphic sequences established by outcrop studies. This allows the subsurface identification of subsiding zones and thus sequence deposit distribution. Seismic mapping of these units boundary shows a structuring from a platform to basin blocks zones and helps to understand the hydrocarbon reservoir systems-tract and horizon distribution around these domains.

Glaciolacustrine deposits formed in an ice-dammed tributary valley in the south-central Pyrenees: New evidence for late Pleistocene climate

Science.gov (United States)

Sancho, Carlos; Arenas, Concha; Pardo, Gonzalo; Peña-Monné, José Luis; Rhodes, Edward J.; Bartolomé, Miguel; García-Ruiz, José M.; Martí-Bono, Carlos

2018-04-01

Combined geomorphic features, stratigraphic characteristics and sedimentologic interpretation, coupled with optically stimulated luminescence (OSL) dates, of a glacio-fluvio-lacustrine sequence (Linás de Broto, northern Spain) provide new information to understand the palaeoenvironmental significance of dynamics of glacier systems in the south-central Pyrenees during the Last Glacial Cycle (≈130 ka to 14 ka). The Linás de Broto depositional system consisted of a proglacial lake fed primarily by meltwater streams emanating from the small Sorrosal glacier and dammed by a lateral moraine of the Ara trunk glacier. The resulting glacio-fluvio-lacustrine sequence, around 55 m thick, is divided into five lithological units consisting of braided fluvial (gravel deposits), lake margin (gravel and sand deltaic deposits) and distal lake (silt and clay laminites) facies associations. Evolution of the depositional environment reflects three phases of progradation of a high-energy braided fluvial system separated by two phases of rapid expansion of the lake. Fluvial progradation occurred during short periods of ice melting. Lake expansion concurred with ice-dam growth of the trunk glacier. The first lake expansion occurred over a time range between 55 ± 9 ka and 49 ± 11 ka, and is consistent with the age of the Viu lateral moraine (49 ± 8 ka), which marks the maximum areal extent of the Ara glacier during the Last Glacial Cycle. These dates confirm that the maximum areal extent of the glacier occurred during Marine Isotope Stages 4 and 3 in the south-central Pyrenees, thus before the Last Glacial Maximum. The evolution of the Linás de Broto depositional system during this maximum glacier extent was modulated by climate oscillations in the northern Iberian Peninsula, probably related to latitudinal shifts of the atmospheric circulation in the southern North-Atlantic Ocean, and variations in summer insolation intensity.

Forced solitary Rossby waves under the influence of slowly varying topography with time

International Nuclear Information System (INIS)

Yang Hong-Wei; Yin Bao-Shu; Yang De-Zhou; Xu Zhen-Hua

2011-01-01

By using a weakly nonlinear and perturbation method, the generalized inhomogeneous Korteweg—de Vries (KdV)—Burgers equation is derived, which governs the evolution of the amplitude of Rossby waves under the influence of dissipation and slowly varying topography with time. The analysis indicates that dissipation and slowly varying topography with time are important factors in causing variation in the mass and energy of solitary waves. (general)

A measurement of summertime dry deposition of ambient air particulates and associated metallic pollutants in Central Taiwan.

Science.gov (United States)

Fang, Guor-Cheng; Chiang, Hung-Che; Chen, Yu-Cheng; Xiao, You-Fu; Wu, Chia-Ming; Kuo, Yu-Chen

2015-04-01

The purpose of this study is to characterize metallic elements associated with atmospheric particulate matter in the dry deposition plate, total suspended particulate, fine particles, and coarse particles at Taichung Harbor and Gong Ming Junior High School (airport) in central Taiwan at a sampling site from June 2013 to August 2013. The results indicated that: (1) the average concentrations of the metallic elements Cr and Cd were highest at the Gong Ming Junior High School (airport), and the average concentrations of the metallic elements Ni, Cu, and Pb were highest at the Taichung Harbor sampling site. (2) The high smelting industry density and export/import rate of heavily loaded cargos were the main reasons leading to these findings. (3) The average metallic element dry deposition and metallic element PM(2.5-10) all followed the order of Pb > Cr > Cu > Ni > Cd at the two sampling sites. However, the average metallic elements Cu and Pb were found to have the highest dry deposition velocities and concentrations in PM(2.5) for the two sampling sites in this study. (4) The correlation coefficients of ambient air particle dry deposition and concentration with wind speed at the airport were higher than those from the harbor sampling site. The wind and broad open spaces at Taichung Airport were the possible reasons for the increasing correlation coefficients for ambient air particle concentration and dry deposition with wind speed at the Taichung Airport sampling site.

A Geochemical Analysis of Rare Earth Elements Associated with Significant Phosphate Deposits of West-Central Florida

Science.gov (United States)

Turner, K. M.; Owens, J. D.

2017-12-01

Rare earth elements (REEs) such as the lanthanide series as well as yttrium, uranium, and thorium are an important industrial resource for expanding technological sectors; therefore, demand and production will continue to increase. Increased market prices resulting in decreased demand has led to new exploration for REE mineral resources in North America. Phosphorite deposits are being investigated as a possible supply but the overall concentrations, depositional environments, and ages are relatively unexplored. Phosphorite is commonly associated with ocean floor sediment deposition and upwelling; however, it may also form in estuarine and supratidal zones with low wave activity, present along Florida's west coast. Interestingly, it seems that major ancient phosphorite deposits are often, if not always, associated with major icehouse conditions (widespread glaciations) and rarely observed during greenhouse conditions. By analyzing a set of sonic drill cores, spatiotemporal REE concentrations can be better constrained for a wide-age range of the Miocene-Pliocene aged Bone Valley Member of the Peace River Formation, the largest North American phosphate deposit. We present concentrations from a depth-transect of samples collected in West-Central Florida, showing the phosphatic sands and silts of the area are highly enriched sedimentary archives for REE, yielding concentrations up to 200 ppm for some REE. The weathering and transport of igneous and metamorphic minerals from the southern Appalachians to the Florida coast where a series of winnowing events occurred may explain the enrichment seen by our data. Sediment cores showing well-rounded quartz sands, dolomitic silts, teeth, bones, and marine fossils commonly found in a near shore depositional environment support this hypothesis. Previous analysis of phosphate grains, teeth, bones, and bulk sediment indicate REE are not associated with and/or sourcing from biogenic components, but rather entering the lattice

Methods, quality assurance, and data for assessing atmospheric deposition of pesticides in the Central Valley of California

Science.gov (United States)

Zamora, Celia; Majewski, Michael S.; Foreman, William T.

2013-01-01

The U.S. Geological Survey monitored atmospheric deposition of pesticides in the Central Valley of California during two studies in 2001 and 2002–04. The 2001 study sampled wet deposition (rain) and storm-drain runoff in the Modesto, California, area during the orchard dormant-spray season to examine the contribution of pesticide concentrations to storm runoff from rainfall. In the 2002–04 study, the number and extent of collection sites in the Central Valley were increased to determine the areal distribution of organophosphate insecticides and other pesticides, and also five more sample types were collected. These were dry deposition, bulk deposition, and three sample types collected from a soil box: aqueous phase in runoff, suspended sediment in runoff, and surficial-soil samples. This report provides concentration data and describes methods and quality assurance of sample collection and laboratory analysis for pesticide compounds in all samples collected from 16 sites. Each sample was analyzed for 41 currently used pesticides and 23 pesticide degradates, including oxygen analogs (oxons) of 9 organophosphate insecticides. Analytical results are presented by sample type and study period. The median concentrations of both chloryprifos and diazinon sampled at four urban (0.067 micrograms per liter [μg/L] and 0.515 μg/L, respectively) and four agricultural sites (0.079 μg/L and 0.583 μg/L, respectively) during a January 2001 storm event in and around Modesto, Calif., were nearly identical, indicating that the overall atmospheric burden in the region appeared to be fairly similar during the sampling event. Comparisons of median concentrations in the rainfall to those in the McHenry storm-drain runoff showed that, for some compounds, rainfall contributed a substantial percentage of the concentration in the runoff; for other compounds, the concentrations in rainfall were much greater than in the runoff. For example, diazinon concentrations in rainfall were about

Optical dating of perennially frozen deposits associated with preserved ancient plant and animal DNA in north-central Siberia

DEFF Research Database (Denmark)

Arnold, L.J.; Roberts, R.G.; Macphee, R.D.E.

2008-01-01

We present chronological constraints on a suite of permanently frozen fluvial deposits which contain ancient DNA (aDNA) from the Taimyr Peninsula of north-central Siberia. The luminescence phenomenology of these samples is first discussed, focusing on the optically stimulated luminescence (OSL) d...... of providing a reliable chronometric framework for sedimentary aDNA records in permafrost environments. (C) 2007 Elsevier Ltd. All rights reserved Udgivelsesdato: 2008...

Iron deposits in the chronically inflamed central nervous system and contributes to neurodegeneration.

Science.gov (United States)

Andersen, Hjalte Holm; Johnsen, Kasper Bendix; Moos, Torben

2014-05-01

Neurodegenerative disorders are characterized by the presence of inflammation in areas with neuronal cell death and a regional increase in iron that exceeds what occurs during normal aging. The inflammatory process accompanying the neuronal degeneration involves glial cells of the central nervous system (CNS) and monocytes of the circulation that migrate into the CNS while transforming into phagocytic macrophages. This review outlines the possible mechanisms responsible for deposition of iron in neurodegenerative disorders with a main emphasis on how iron-containing monocytes may migrate into the CNS, transform into macrophages, and die out subsequently to their phagocytosis of damaged and dying neuronal cells. The dying macrophages may in turn release their iron, which enters the pool of labile iron to catalytically promote formation of free-radical-mediated stress and oxidative damage to adjacent cells, including neurons. Healthy neurons may also chronically acquire iron from the extracellular space as another principle mechanism for oxidative stress-mediated damage. Pharmacological handling of monocyte migration into the CNS combined with chelators that neutralize the effects of extracellular iron occurring due to the release from dying macrophages as well as intraneuronal chelation may denote good possibilities for reducing the deleterious consequences of iron deposition in the CNS.

Atmospheric deposition of beryllium in Central Europe: Comparison of soluble and insoluble fractions in rime and snow across a pollution gradient

International Nuclear Information System (INIS)

Bohdalkova, Leona; Novak, Martin; Voldrichova, Petra; Prechova, Eva; Veselovsky, Frantisek; Erbanova, Lucie; Krachler, Michael; Komarek, Arnost; Mikova, Jitka

2012-01-01

Little is known about atmospheric input of beryllium (Be) into ecosystems, despite its highly toxic behavior. For three consecutive winters (2009–2011), we measured Be concentrations in horizontal deposition (rime) and vertical deposition (snow) at 10 remote mountain-top locations in the Czech Republic, Central Europe. Beryllium was determined both in filtered waters, and in HF digests of insoluble particles. Across the sites, soluble Be concentrations in rime were 7 times higher, compared to snow (6.1 vs. 0.9 ng·L −1 ). Rime scavenged the pollution-rich lower segments of clouds. The lowest Be concentrations were detected in the soluble fraction of snow. Across the sites, 34% of total Be deposition occurred in the form of soluble (bioavailable) Be, the rest were insoluble particles. Beryllium fluxes decreased in the order: vertical dry deposition insoluble > vertical dry deposition soluble > horizontal deposition soluble > vertical wet deposition insoluble > vertical wet deposition soluble > horizontal deposition insoluble. The average contributions of these Be forms to total deposition were 56, 21, 8, 7, 5 and 3%, respectively. Sites in the northeast were more Be-polluted than the rest of the country with sources of pollution in industrial Silesia. -- Highlights: ► We measured Be concentrations in rime and snow in the Czech Republic. ► Soluble Be concentrations in rime were 7 times higher than in snow. ► 34% of total Be deposition occurred in the form of soluble (bioavailable) Be. ► Dry-deposited fluxes dominated Be inputs. ► Soluble Be concentrations only rarely exceeded 30 ng·L −1 .

Depositional model for Rival and Midale subintervals (Mississippian), north-central Burke County, North Dakota

Energy Technology Data Exchange (ETDEWEB)

Harris, T.L.

1988-07-01

The Rival and Midale subintervals (Charles Formation, Upper Mississippian), north-central Burke County, North Dakota, represent two relative sea level fluctuations. Updip (northeast), the Rival subinterval contains fine to medium-bedded and chicken-wire anhydrite with interbedded algal bindstone that was deposited on supratidal flats. Basinward (southwest), the lithology changes to oncolitic, peloidal, intraclastic grainstone/packstone that was deposited in intertidal and subtidal restricted lagoonal environments. Evaporites precipitated in the sediment of the intertidal to shallow subtidal restricted lagoonal environment. Overlying the Rival subinterval is skeletal wackestone and packstone of the lower Midale subinterval. The presence of normal-marine fauna (crinoids, brachiopods, trilobites, rugose and tabulate coral) indicates a significant relative sea level transgression occurred following deposition of the Rival. The middle and upper Midale subinterval consists of intensely burrowed dolowackestone and dolomudstone that contain a less diversified faunal assemblage. Overlying the Midale carbonates is a transitional zone of calcareous shale and dolomite that grades upward into mottled (burrowed.) and finely laminated microgranular dolomite and anhydrite. The upper Midale section represents a relative sea level regression (shoreline progradation). Updip (northeast) reservoirs produce from the Midale carbonates, which are sealed laterally and vertically by calcarous shale and microgranular dolomitic anhydrite of the Midale Evaporite. Downdip (southwest), the Rival produces from porous grainstone, which is sealed laterally by intertidal/supratidal carbonates and evaporites, resulting in a stratigraphic trap. Vuggy and intergranular porosity are the major porosity types in the Rival grainstone, and moldic and intercrystalline porosity are dominant in the Midale dolowackestone.

Depositional setting and early diagenesis of the dinosaur eggshell-bearing Aren Fm at Bastus, Late Campanian, south-central Pyrenees

Science.gov (United States)

Díaz-Molina, Margarita; Kälin, Otto; Benito, M. Isabel; Lopez-Martinez, Nieves; Vicens, Enric

2007-07-01

The Late Cretaceous Aren Fm exposed north of Bastus in the Tremp Basin (south-central Pyrenees) preserves an excellent record of dinosaur eggs laid in a marine littoral setting. Different from other cases reported in literature, at the Bastus site the preferential nesting ground was original beach sand. The coastal deposits of Aren Fm can be grouped into four facies assemblages, representing respectively shoreface, beachface, beach ridge plain and backbarrier lagoon environments. Shoreface deposits include fine- to coarse-grained hybrid arenites and subordinate quartz-dominated conglomerates with ripple structures of wave and wave-current origin. Beachface deposits are mainly storm beach conglomerates, but parallel-laminated foreshore arenites locally occur. Backbarrier lagoon deposits comprise of washover sandy conglomerates that grade laterally into sandy lime mudstones, biomicrites and marls. Beach ridge sediment, wherein the bulk of dinosaur eggs and eggshell debris occurs, predominantly is a reddish hybrid arenite that has undergone a complex early diagenetic evolution, including marine and meteoric cementation followed by soil development. The reddish arenites overlie wave-dominated shoreface deposits and in places pass laterally into lagoonal deposits. They originally formed shore ridges, that became stabilized during progradational episodes by pedogenesis (beach ridge, sensu [Otvos, E.G., 2000. Beach ridges—definitions and significance. Geomorphology 32, 83-108.]), which also affected the dinosaur eggs. The eggshell-bearing beach ridge arenites are typically preserved at the top of parasequences forming the systems tracts of a third-order sequence. Thick packages of this facies resulted from aggradation of barrier/beach ridge deposits, whose preservation below surfaces of transgressive erosion was favoured by incipient lithification.

Sandy aeolian deposits and environments and their relation to climate during the Last Glacial Maximum and Lateglacial in northwest and central Europe

NARCIS (Netherlands)

Kasse, C.

2002-01-01

Periglacial aeolian sand sheets and dunes of the last glacial cover extensive areas of northwest and central Europe. Four sedimentary facies have been described that could be related to fluvio-aeolian and cryogenic processes, moisture content of the depositional surface and surface morphology.

Cesium levels in foodstuffs fall slowly

International Nuclear Information System (INIS)

Rantavaara, A.

1994-01-01

Since spring 1986, radioactive decay has reduced the total amount of radioactive cesium 137 in the Finnish environment, originating in Chernobyl, by 17 per cent. The cesium content in fish keeps falling at a diminishing rate, depending on the species of fish and environmental factors. The use of fish from lakes need not be restricted anymore. The cesium contents of game, mushrooms and wild berries have remained steady for some years now. The same is true for agricultural produce. The contents in milk and meat still keep falling slowly. Most of the cesium ingested by finns comes from fish, then from game, reindeer and gathered foods; the lowest amounts are received from agricultural products. (orig.)

Correlation and stratigraphic eruption age of the pyroclastic flow deposits and wide spread volcanic ashes intercalated in the Pliocene-Pleistocene strata, central Japan

International Nuclear Information System (INIS)

Nagahashi, Yoshitaka; Satoguchi, Yasufumi; Yoshikawa, Shusaku

2000-01-01

Three pyroclastic flow deposits in the Takayama and Omine area, central Honshu, are correlated to the distal widespread volcanic ashes intercalated in the Plio-Pleistocene boundary strata in central Japan. The correlation is based on these stratigraphic relationships, facies, magnetostratigraphy, petrographic properties such as mineral assemblage, refractive index and chemical composition of the volcanic glasses and orthopyroxene. As the result of these correlation, the eruption age of the proximal pyroclastic flow deposits have become clear. And precise correlation between proximal eruption units and distal depositional units is now possible. Ho-Kd 39 Tephra erupted at about 1.76 Ma, forming a co-ignimbrite ash, which deposited in the Kanto sedimentary basin. Eb-Fukuda Tephra erupted at about 1.75 Ma, and distal volcaniclastic deposit sedimented in the Kinki, Niigata and Kanto sedimentary basins. The eruptional and depositional phase are divided into the stage 1, stage 2 (early), stage 2 (late) and stage 3. Stage 1 is phreato-plinian type eruption phase, forming distal ash fall deposit. Stage 2 (early) is plinian pumice fall, intra-plinian pyroclastic flow and plinian pumice fall eruption phase, forming distal ash fall. Stage 2 (late) is final eruptional phase of the biggest pyroclastic flow of the Eb-Fukuda Tephra, forming a co-ignimbrite ash fall. Stage 3 is resedimented stage after the end of the explosive eruption. It is notable that resedimented volcaniclastic deposit reached Osaka sedimentary basin 300 km away from the eruption center. Om-SK110 Tephra erupted at about 1.65 Ma, divided into the stage 1, stage 2 and stage 3. Stage 1 is eruption phase of the plinian pumice fall and first pyroclastic flow. Stage 2 is pauses in eruption activity. Stage 3 is second pyroclastic flow phase, it is inferred that the pyroclastic flow of the stage 3 directly entered the Niigata sedimentary basin and simultaneously formed a co-ignimbrite ash. (author)

Hydrothermal Fe-Si-Mn oxide deposits from the Central and South Valu Fa Ridge, Lau Basin

International Nuclear Information System (INIS)

Sun Zhilei; Zhou Huaiyang; Yang Qunhui; Sun Zhixue; Bao Shenxu; Yao Huiqiang

2011-01-01

Highlights: → The Fe-Mn crust in the HHF has seawater contribution, whereas the Fe-Si oxide in the MHF is dominated by hydrothermal fluid → The Nd isotope of diffuse flow Fe-Si-Mn deposits indicates the obvious hydrothermal origin. → The Mn/Fe ratio in hydrothermal deposit may be a good indicator of propagating activities of the Valu Fa Ridge. - Abstract: A series of samples from the Hine Hina hydrothermal field (HHF) and the Mariner hydrothermal field (MHF) in the Central and Southern Valu Fa Ridge (VFR), Lau Basin were examined to explain the source origin and formation of the hydrothermal Fe-Si-Mn oxide deposits. The mineralogy was studied by X-ray diffraction (XRD), scanning electron microscopy (SEM), Moessbauer spectroscopy, and energy-dispersive spectroscopy (EDS). For the Fe-Mn oxide crusts in the HHF, varying amounts of volcanic fragments and some seawater contributions were recognized, along with higher concentrations of Mn, Al, Co, Ni, Zn, Sr, Mo, elevated ΣREE and negative Ce anomalies. In contrast, the Si-rich oxide samples of the MHF were enriched in Cu, Pb and Ba, indicative of proximity to a hydrothermal jet. Moreover, conductive cooling of hydrothermal fluid evoked the Si-rich deposit formation in the MHF. The Sr, Nd and Pb isotope data provided further constraints regarding the source and formation of the Fe-Si-Mn deposits in the VFR by showing that the samples of the HHF are a mixture of three components, namely, hydrothermal fluid, seawater and volcanic materials, whereas the samples of the MHF were dominated by hydrothermal fluids. The seawater had a minor influence on the Nd isotope data, and the Pb isotope data exhibited a close association with the substrate rock and preformed volcaniclastic layers in this area. The occurrence of relatively high Mn/Fe ratios in the hydrothermal deposits of this area may be a good indicator of the propagating activities of the VFR over geological time.

Estimation of PAHs dry deposition and BaP toxic equivalency factors (TEFs) study at Urban, Industry Park and rural sampling sites in central Taiwan, Taichung.

Science.gov (United States)

Fang, Guor-Cheng; Chang, Kuan-Foo; Lu, Chungsying; Bai, Hsunling

2004-05-01

The concentrations of polycyclic aromatic hydrocarbons (PAHs) in gas phase and particle bound were measured simultaneously at industrial (INDUSTRY), urban (URBAN), and rural areas (RURAL) in Taichung, Taiwan. And the PAH concentrations, size distributions, estimated PAHs dry deposition fluxes and health risk study of PAHs in the ambient air of central Taiwan were discussed in this study. Total PAH concentrations at INDUSTRY, URBAN, and RURAL sampling sites were found to be 1650 +/- 1240, 1220 +/- 520, and 831 +/- 427 ng/m3, respectively. The results indicated that PAH concentrations were higher at INDUSTRY and URBAN sampling sites than the RURAL sampling sites because of the more industrial processes, traffic exhausts and human activities. The estimation dry deposition and size distribution of PAHs were also studied. The results indicated that the estimated dry deposition fluxes of total PAHs were 58.5, 48.8, and 38.6 microg/m2/day at INDUSTRY, URBAN, and RURAL, respectively. The BaP equivalency results indicated that the health risk of gas phase PAHs were higher than the particle phase at three sampling sites of central Taiwan. However, compared with the BaP equivalency results to other studies conducted in factory, this study indicated the health risk of PAHs was acceptable in the ambient air of central Taiwan.

Soft-sediment deformation structures in cores from lacustrine slurry deposits of the Late Triassic Yanchang Fm. (central China

Directory of Open Access Journals (Sweden)

Yang Renchao

2016-09-01

Full Text Available The fine-grained autochthonous sedimentation in the deep part of a Late Triassic lake was frequently interrupted by gravity-induced mass flows. Some of these mass flows were so rich in water that they must have represented slurries. This can be deduced from the soft-sediment deformation structures that abound in cores from these lacustrine deposits which constitute the Yanchang Fm., which is present in the Ordos Basin (central China.

Descriptive models, grade-tonnage relations, and databases for the assessment of sediment-hosted copper deposits: with emphasis on deposits in the Central Africa Copperbelt, Democratic Republic of the Congo and Zambia: Chapter J in Global mineral resource assessment

Science.gov (United States)

Taylor, Cliff D.; Causey, J. Douglas; Denning, Paul; Hammarstrom, Jane M.; Hayes, Timothy S.; Horton, John D.; Kirschbaum, Michael J.; Parks, Heather L.; Wilson, Anna B.; Wintzer, Niki E.; Zientek, Michael L.

2013-01-01

The Central African Copperbelt (CACB) is one of the most important copper-producing regions of the world. The majority of copper produced in Africa comes from this region defined by the Neoproterozoic Katanga sedimentary basin of the southern Democratic Republic of the Congo (DRC) and northern Zambia. Copper in the CACB is mined from sediment-hosted stratabound copper deposits associated with red beds and includes the giant deposits in the Kolwezi and Tenge-Fungurume districts in the DRC and the Konkola-Musoshi and Nchanga-Chingola districts in Zambia. In recent years, sediment-hosted structurally controlled replacement and vein (SCRV) copper deposits, such as the giant Kansanshi deposit in Zambia have become important exploration targets in the CACB region.

Short Term vs Long Term Environmental Reconstruction from Carbonated Deposits of the Limagne Area (Massif Central, France)

Energy Technology Data Exchange (ETDEWEB)

Barbecot, F.; Gibert, E.; Amokrane, Y.; Massault, M.; Noret, A. [Centre National de la Recherche Scientifique Interaction et Dynamique des Environnements de Surface, Universite Paris (France); Ghaleb, B. [Geotop, Universite du Quebec a Montreal, Montreal (Canada)

2013-07-15

A 80 cm sequence has been cored from carbonated travertine in the limagne area (French Massif Central, France) in order to document recent environmental fluctuations (0-100 a) of gaseous springs, in relation to the environmental and geochemical parameters that control the isotopic signatures of modern carbonate deposits. The chronology of these finely laminated deposits that are ideal for reconstructing hydrological conditions at very narrow time steps is determined through AMS-{sup 14}C and {sup 210}Pb/{sup 226}Ra radiometric methods. Preliminary results highlight a high enrichment in stable isotopes (eg up to +8 per mille vs VPDB for {delta}{sup 13}C), likely linked to both recharge temperature and degassing processes. Moreover, two general trends are superimposed: the first one, cyclic, may be correlated to the hydrologic annual/biannual budget while the second one, linear, implies a long term environmental trend. (author)

Peralkaline- and calc-alkaline-hosted volcanogenic massive sulfide deposits of the Bonnifield District, East-Central Alaska

Science.gov (United States)

Dusel-Bacon, Cynthia; Foley, Nora K.; Slack, John E.; Koenig, Alan E.; Oscarson, Robert L.

2012-01-01

Volcanogenic massive sulfide (VMS) Zn-Pb-Cu-Ag-Au deposits of the Bonnifield mining district formed during Late Devonian-Early Mississippian magmatism along the western edge of Laurentia. The largest deposits, Dry Creek and WTF, have a combined resource of 5.7 million tonnes at 10% Zn, 4% Pb, 0.3% Cu, 300 grams per tonne (g/t) Ag, and 1.6 g/t Au. These polymetallic deposits are hosted in high field strength element (HFSE)- and rare-earth element (REE)-rich peralkaline (pantelleritic) metarhyolite, and interlayered pyritic argillite and mudstone of the Mystic Creek Member of the Totatlanika Schist Formation. Mystic Creek metarhyolite and alkali basalt (Chute Creek Member) constitute a bimodal pair that formed in an extensional environment. A synvolcanic peralkaline quartz porphyry containing veins of fluorite, sphalerite, pyrite, and quartz intrudes the central footwall at Dry Creek. The Anderson Mountain deposit, located ~32 km to the southwest, occurs within calc-alkaline felsic to intermediate-composition metavolcanic rocks and associated graphitic argillite of the Wood River assemblage. Felsic metavolcanic rocks there have only slightly elevated HFSEs and REEs. The association of abundant graphitic and siliceous argillite with the felsic volcanic rocks together with low Cu contents in the Bonnifield deposits suggests classification as a siliciclastic-felsic type of VMS deposit. Bonnifield massive sulfides and host rocks were metamorphosed and deformed under greenschist-facies conditions in the Mesozoic. Primary depositional textures, generally uncommon, consist of framboids, framboidal aggregates, and spongy masses of pyrite. Sphalerite, the predominant base metal sulfide, encloses early pyrite framboids. Galena and chalcopyrite accompanied early pyrite formation but primarily formed late in the paragenetic sequence. Silver-rich tetrahedrite is a minor late phase at the Dry Creek deposit. Gold and Ag are present in low to moderate amounts in pyrite from all of

Mineralogy and Trace Element Chemistry of Ferberite/Reinite from Tungsten Deposits in Central Rwanda

Directory of Open Access Journals (Sweden)

Philippe Muchez

2013-04-01

Full Text Available Tungsten mineralization in hydrothermal quartz veins from the Nyakabingo,Gifurwe and Bugarama deposits in central Rwanda occurs as the iron-rich endmember ofthe wolframite solid solution series (ferberite and in the particular form of reinite, whichrepresents a pseudomorph of ferberite after scheelite. Primary ferberite, reinite and latesecondary ferberite are characterized by their trace element chemistry and rare earthelement patterns. The replacement of scheelite by ferberite is also documented in the traceelement composition. Primary ferberite shows high Mg, Zn, Sc, V, Nb, In and Snconcentrations, but very low Ca, Pb, Sr and Ba contents. Reinite and late secondaryferberite display an uncommon trace element composition containing high concentrationsof Ca, Pb, Sr, Ba, As and Ga, but very low levels in Sn, Zr, Hf, In, Ti, Sc, Nb, Ta, Mg andZn. Late secondary ferberite replacing primary ferberite is characterized by additionalenrichments in Bi, Pb, As and Sb. The rare earth element patterns of reinite and secondaryferberite are also similar to hydrothermal scheelite. The formation of the tungsten depositsin central Rwanda is interpreted to be epigenetic in origin, and the hydrothermalmineralizing fluids are related to the intrusion of the G4-granites.

Chemical and boron isotopic composition of tourmaline from the Mariinsky emerald deposit, Central Urals, Russia

Science.gov (United States)

Baksheev, Ivan A.; Trumbull, Robert B.; Popov, Mikhail P.; Erokhin, Yuri V.; Kudryavtseva, Olesya E.; Yapaskurt, Vasily O.; Khiller, Vera V.; Vovna, Galina M.; Kiselev, Vladimir I.

2018-04-01

Tourmaline is abundant at the Mariinsky schist-hosted emerald deposit in the Central Urals, Russia, both in emerald-bearing phlogopite veins (type 1) and later, emerald-free pockets, lenses, and veinlets cutting the phlogopite veins (type 2). The Ca content in tourmaline is influenced by the host rocks (ultramafic and mafic rocks), associated minerals, and minerals crystallized before tourmaline (amphibole, fluorite, margarite). The Na concentration in tourmaline depends on the presence or absence of paragonite, and the association with micas also strongly influences the contents of Li, Zn, Ni, and Co in tourmaline. Type 1 tourmalines associated with phlogopite are relatively depleted in these elements, whereas type 2 tourmalines associated with margarite or paragonite are enriched. Some differences in isomorphic substitutions along with the trace element composition (Zn, V, Sr, Co, REE) may have value in exploration of emerald-bearing and emerald-free veins in schist-hosted emerald deposits. The δ11B values in tourmaline of all types fall in a narrow total range from -11.3 to -8.4‰. These values, combined with a mineralization temperature of 420-360 °C, yield an estimated δ11B fluid composition of -7.4 to -6.8‰ suggesting a mixed source of boron, likely dominated from the granitic rocks surrounding the emerald belt. The narrow range of B-isotope compositions in tourmaline from throughout the Mariinsky deposit suggests a well-mixed hydrothermal system.

Weakly Coupled Oscillators in a Slowly Varying World

OpenAIRE

Park, Youngmin; Ermentrout, Bard

2016-01-01

We extend the theory of weakly coupled oscillators to incorporate slowly varying inputs and parameters. We employ a combination of regular perturbation and an adiabatic approximation to derive equations for the phase-difference between a pair of oscillators. We apply this to the simple Hopf oscillator and then to a biophysical model. The latter represents the behavior of a neuron that is subject to slow modulation of a muscarinic current such as would occur during transient attention through ...

Oceanic ferromanganese deposits: Future resources and past-ocean recorders

Digital Repository Service at National Institute of Oceanography (India)

Banakar, V.K.; Nair, R.R.; Parthiban, G.; Pattan, J.N.

decades following the Mero's publication witnessed global "Nodule Rush". The technological leaders of those years like US, Germany, Japan, France, New-Zealand, and USSR have conducted major scientific expeditions to the Central Pacific to map...-Mn-(Cu+Ni+Co) in ferromanganese deposits from the Central Indian Ocean (Source: Jauhari, 1987). OCEANIC FERROMANGANESE DEPOSITS 45 DISTRIBUTION The nodules occur invariably in almost all the deep-sea basins witnessing low sedimentation rates. But abundant ore grade deposits...

Depositional setting and early diagenesis of the dinosaur eggshell-bearing Aren Fm at Bastus, Late Campanian, south-central Pyrenees

OpenAIRE

Díaz Molina, Margarita; Kälin, Otto; Benito Moreno, María Isabel; López Martínez, Nieves; Vicens, Enric

2007-01-01

The Late Cretaceous Aren Fm exposed north of Bastus in the Tremp Basin (south-central Pyrenees) preserves an excellent record of dinosaur eggs laid in a marine littoral setting. Different from other cases reported in literature, at the Bastus site the preferential nesting ground was original beach sand. The coastal deposits of Aren Fm can be grouped into four facies assemblages, representing respectively shoreface, beachface, beach ridge plain and backbarrier lagoon environments. Shoreface de...

Petroleum demand continues to grow but slowly

International Nuclear Information System (INIS)

Anon.

1998-01-01

While it is always entertaining and intellectually stimulating to look at all the marvelous technological alternatives just around the corner for transport, the transport task in Australia continues to grow and so does petroleum consumption. Australia presently consumes more than 750,000 barrels per day of petroleum products. Latest figures are given for petroleum consumption up to the end of August 1998. They indicate that total demand for petrol has continued to grow, but very slowly. Growth in 1997-1998 compared with 1996-1997 was only 0.3%. This trend for very low growth has been continued into July and August, perhaps indicative of a slow down in the economy

Quaternary geologic map of the north-central part of the Salinas River Valley and Arroyo Seco, Monterey County, California

Science.gov (United States)

Taylor, Emily M.; Sweetkind, Donald S.

2014-01-01

Arroyo Seco, a perennial drainage in the central Coast Range of California, records a sequence of strath terraces. These terraces preserve an erosional and depositional history, controlled by both climate change and regional tectonics. These deposits have been mapped and correlated on the basis of field investigations, digital terrain analysis, stream gradient profiles, evaluation of published regional soil maps, and satellite imagery. Seven of the strath terraces and associated alluvial fans have been dated by optically stimulated luminescence (OSL) or infrared stimulated luminescence (IRSL). The OSL and IRSL dates on seven of the strath terraces and associated alluvial fans in Arroyo Seco are approximately >120 ka, >65 ka, 51–46 ka, 36–35 ka, 9 ka, and 2–1 ka. These dates generally fall within the range of ages reported from many well-dated marine terraces on the California coast that are formed during sea-level high stands. Tectonic movements, consistently upward, result in a constantly and slowly emerging coastline, however, the regional effects of climate change and resulting eustatic sea-level rises are interpreted as the driving mechanism for erosion and aggradation in Arroyo Seco.

Thermal radiation and nonthermal radiation of the slowly changing dynamic Kerr–Newman black hole

International Nuclear Information System (INIS)

Meng Qingmiao; Wang Shuai; Jiang Jijian; Deng Deli

2008-01-01

Using the related formula of dynamic black hole, we have calculated the instantaneous radiation energy density of the slowly changing dynamic Kerr–Newman black hole. It is found that the instantaneous radiation energy density of a black hole is always proportional to the quartic of the temperature of the event horizon in the same direction. By using the Hamilton–Jacobin equation of scalar particles in the curved spacetime, the spontaneous radiation of the slowly changing dynamic Kerr–Newman black hole is studied. The energy condition for the occurrence of the spontaneous radiation is obtained. (general)

Sound transmission in slowly varying circular and annular ducts with flow

NARCIS (Netherlands)

Rienstra, S.W.

1999-01-01

Sound transmission through straight circular ducts with a uniform inviscid mean flow and a constant acoustic lining (impedance wall) is classically described by a modal expansion. A natural extension for ducts with axially slowly varying properties (diameter and mean flow, wall impedance) is a

Dimensional Modeling By Using a New Response to Slowly Changing Dimensions

DEFF Research Database (Denmark)

Frank, L.; Frank, C.; Jensen, Christian Søndergaard

2005-01-01

Dimensions are defined as dynamic or slowly changing if the attributes or relationships of a dimension can be updated. Aggregations to dynamic dimensions might be misleading if the measures are aggregated without regarding the changes of the dimensions. Kimball et al. has described three classic ...

BSW process of the slowly evaporating charged black hole

OpenAIRE

Wang, Liancheng; He, Feng; Fu, Xiangyun

2015-01-01

In this paper, we study the BSW process of the slowly evaporating charged black hole. It can be found that the BSW process will also arise near black hole horizon when the evaporation of charged black hole is very slow. But now the background black hole does not have to be an extremal black hole, and it will be approximately an extremal black hole unless it is nearly a huge stationary black hole.

Magnetostratigraphy, paleomagnetic correlation, and deformation of pleistocene deposits in the south central Puget Lowland, Washington

Science.gov (United States)

Hagstrum, J.T.; Booth, D.B.; Troost, K.G.; Blakely, R.J.

2002-01-01

Paleomagnetic results from Pleistocene sedimentary deposits in the central Puget Lowland indicate that the region has experienced widespread deformation within the last 780 kyr. Three oriented samples were collected from unaltered fine-grained sediments mostly at sea level to determine the magnetostratigraphy at 83 sites. Of these, 47 have normal, 18 have reversed, and 18 have transitional (8 localities) polarities. Records of reversed- to normal-polarity transitions of the geomagnetic field were found in thick sections of silt near the eastern end of the Tacoma Narrows Bridge, and again at Wingehaven Park near the northern tip of Vashon Island. The transitional horizons, probably related to the Bruhnes-Matuyama reversal, apparently fall between previously dated Pleistocene sediments at the Puyallup Valley type section (all reversed-polarity) to the south and the Whidbey Island type section (all normal-polarity) to the north. The samples, in general, are of sufficient quality to record paleosecular variation (PSV) of the geomagnetic field, and a statistical technique is used to correlate horizons with significant agreement in their paleomagnetic directions. Our data are consistent with the broad structures of the Seattle uplift inferred at depth from seismic reflection, gravity, and aeromagnetic profiles, but the magnitude of vertical adjustments is greatly subdued in the Pleistocene deposits.

Radiocarbon ages of upper quaternary deposit in central Nepal and their geomorphological significance

International Nuclear Information System (INIS)

Yamanaka, Hidetsugu

1982-01-01

The author visited Nepal from October, 1980, to February, 1981, investigated the geomorphology and upper Quaternary geology in Central Nepal, and collected a number of samples for radiocarbon dating. After returning to his university, he dated ten samples by himself. In Nepal, radiocarbon age has been scarcely reported as yet, besides in Kathmandu valley. Therefore, the author's ten data of the age are very important for the late Quaternary chronological study of Nepal Himalayas. In this paper, the author describes sampling localities and horizons, dating results and their geomorphological significance. These ten samples included Pokhara valley, Marsyandi Kohla, Modi Khola, Madi Khola and Muktinath samples. Some conclusion was derived as for the geomorphological development in central Nepal: The last Himalayan glacial age had already ended before 9,000 yr BP (years before A.D. 1950); In the Midland region, from 4,300 to 600 yr BP, some large-scale mudflows broke out nearly contemporaneously in the upper valleys, and they flowed down torrentially and catastrophically to deposit in the middle course of rivers. But the cause of vast quantity of material suddenly brought down from the Great Himalayas has been still left unexplained. The conclusion like this also was able to be applied to the middle Marsyandi Khola and the Pokhara valley. The wide-spread schema that the river was aggraded in the glacial age and degraded in the interglacial age may not be applicable to the rivers in the Midland region of Nepal Himalayas. (Wakatsuki, Y.)

Cell cycle disturbances in slowly growing sublines isolated from X-irradiated L5178Y-S cell populations

International Nuclear Information System (INIS)

Beer, J.Z.; Bocian, E.; Budzicka, E.; Szumiel, I.; Ziemba-Zak, B.; Kopec, M.

1974-01-01

Cell cycle was analyzed autoradiographically in a test line of murine leukaemic lymphoblasts L5178Y-S and in two slowly growing sublines isolated from cell cultures irradiated with 300 rad of X-rays. It was found that prolongation of the cell cycle in the slowly growing sublines is connected primarily with delayed progression through G2 phase. This conclusion was further supported by results of determination of DNA content per cell in 13 slowly growing cell sublines and karyotype analysis of 18 sublines. No correlation was found between a sublines' mean doubling time and its chromosome number whereas DNA content per cell was clearly dependent on the growth rate. (author)

Slowly moving test charge in two-electron component non-Maxwellian plasma

International Nuclear Information System (INIS)

Ali, S.; Eliasson, B.

2015-01-01

Potential distributions around a slowly moving test charge are calculated by taking into account the electron-acoustic waves in an unmagnetized plasma. Considering a neutralizing background of static positive ions, the supra-thermal hot and cold electrons are described by the Vlasov equations to account for the Kappa (power-law in velocity space) and Maxwell equilibrium distributions. Fourier analysis further leads to the derivation of electrostatic potential showing the impact of supra-thermal hot electrons. The test charge moves slowly in comparison with the hot and cold electron thermal speeds and is therefore shielded by the electrons. This gives rise to a short-range Debye-Hückel potential decaying exponentially with distance and to a far field potential decaying as inverse third power of the distance from the test charge. The results are relevant for both laboratory and space plasmas, where supra-thermal hot electrons with power-law distributions have been observed

Depositional environments and sequence stratigraphy of the Bahram Formation (middle–late Devonian in north of Kerman, south-central Iran

Directory of Open Access Journals (Sweden)

Afshin Hashmie

2016-09-01

Full Text Available This study is focused on sedimentary environments, facies distribution, and sequence stratigraphy. The facies and sequence stratigraphic analyses of the Bahram Formation (middle–late Devonian in south-central Iran are based on two measured stratigraphic sections in the southern Tabas block. The Bahram Formation overlies red sandstones Padeha Formation in sections Hutk and Sardar and is overlain by Carboniferous carbonate deposits of Hutk Formation paraconformably, with a thickness of 354 and 386 m respectively. Mixed siliciclastic and carbonate sediments are present in this succession. The field observations and laboratory studies were used to identify 14 micro/petrofacies, which can be grouped into 5 depositional environments: shore, tidal flat, lagoon, shoal and shallow open marine. A mixed carbonate-detrital shallow shelf is suggested for the depositional environment of the Bahram Formation which deepens to the east (Sardar section and thins in southern locations (Hutk section. Three 3rd-order cyclic siliciclastic and carbonate sequences in the Bahram Formation and one sequence shared with the overlying joint with Hutk Formation are identified, on the basis of shallowing upward patterns in the micro/pertofacies.

A genetic model based on evapoconcentration for sediment-hosted exotic-Cu mineralization in arid environments: the case of the El Tesoro Central copper deposit, Atacama Desert, Chile

Science.gov (United States)

Fernández-Mort, A.; Riquelme, R.; Alonso-Zarza, A. M.; Campos, E.; Bissig, T.; Mpodozis, C.; Carretier, S.; Herrera, C.; Tapia, M.; Pizarro, H.; Muñoz, S.

2017-12-01

Although the formation of exotic-Cu deposits is controlled by multiple factors, the role of the sedimentary environment has not been well defined. We present a case study of the El Tesoro Central exotic-Cu deposit located in the Atacama Desert of northern Chile. This deposit consists of two mineralized bodies hosted within Late Cenozoic gravels deposited in an arid continental environment dominated by alluvial fans with sub-surficial ponded water bodies formed at the foot of these fans or within the interfan areas. Both exotic-Cu orebodies mostly consist of chrysocolla, copper wad, atacamite, paratacamite, quartz, opal, and calcite. The most commonly observed paragenesis comprises chrysocolla, silica minerals, and calcite and records a progressive increase in pH, which is notably influenced by evaporation. The results of stable isotope analyses (δ13C and δ18O) and hydrogeochemical simulations confirm that evapoconcentration is the main controlling factor in the exotic-Cu mineralization at El Tesoro Central. This conclusion complements the traditional genetic model based on the gradual neutralization of highly oversaturated Cu-bearing solutions that progressively cement the gravels and underlying bedrock regardless of the depositional environment. This study concludes that in exotic-Cu deposits formed relatively far from the source, a favorable sedimentary environment and particular hydrologic and climatic conditions are essential to trap, accumulate, evapoconcentrate, neutralize and saturate Cu-bearing solutions to trigger mineralization. Thus, detailed sedimentological studies should be incorporated when devising exploration strategies in order to discover new exotic-Cu resources, particularly if they are expected to have formed relatively far from the metal sources.

Stratigraphy, age, and depositional setting of the Miocene Barstow Formation at Harvard Hill, central Mojave Desert, California

Science.gov (United States)

Leslie, Shannon R.; Miller, David M.; Wooden, Joseph L.; Vazquez, Jorge A.

2010-01-01

New detailed geologic mapping and geochronology of the Barstow Formation at Harvard Hill, 30 km east of Barstow, CA, help to constrain Miocene paleogeography and tectonics of the central Mojave Desert. A northern strand of the Quaternary ENE-striking, sinistral Manix fault divides the Barstow Formation at Harvard Hill into two distinct lithologic assemblages. Strata north of the fault consist of: a green rhyolitic tuff, informally named the Shamrock tuff; lacustrine sandstone; partially silicified thin-bedded to massive limestone; and alluvial sandstone to pebble conglomerate. Strata south of the fault consist of: lacustrine siltstone and sandstone; a rhyolitic tuff dated at 19.1 Ma (U-Pb); rock-avalanche breccia deposits; partially silicified well-bedded to massive limestone; and alluvial sandstone and conglomerate. Our U-Pb zircon dating of the Shamrock tuff by SHRIMP-RG yields a peak probability age of 18.7 ± 0.1 Ma. Distinctive outcrop characteristics, mineralogy, remanent magnetization, and zircon geochemistry (Th/U) suggest that the Shamrock tuff represents a lacustrine facies of the regionally extensive Peach Spring Tuff (PST). Here we compare zircon age and geochemical analyses from the Shamrock tuff with those of the PST at Stoddard Wash and provide new insight into the age of zircon crystallization in the PST rhyolite. Results of our field studies show that Miocene strata at Harvard Hill mostly accumulated in a lacustrine environment, although depositional environments varied from a relatively deep lake to a very shallow lake or even onshore setting. Rock-avalanche breccias and alluvial deposits near the base of the exposed section indicate proximity to a steep basin margin and detrital studies suggest a southern source for coarse-grained deposits; therefore, we may infer a southern basin-margin setting at Harvard Hill during the early Miocene. Our geochronology demonstrates that deposition of the Barstow Formation at Harvard Hill extended from before

Selective transport of palynomorphs in marine turbiditic deposits: An example from the Ascension-Monterey Canyon system offshore central California

Science.gov (United States)

McGann, Mary

2017-01-01

The pollen assemblage of a deep-sea core (15G) collected at lower bathyal depths (3491 m) on a levee of Monterey Canyon off central California was investigated to gain insights into the delivery processes of terrigenous material to submarine fans and the effect this transport has on the palynological record. Thirty-two samples were obtained down the length of the core, 19 from hemipelagic and mixed mud deposits considered to be the background record, and 13 others from displaced flow deposits. The pollen record obtained from the background samples documents variations in the terrestrial flora as it adapted to changing climatic conditions over the last 19,000 cal yrs BP. A Q-mode cluster analysis defined three pollen zones: a Glacial Pollen Zone (ca. 20,000–17,000 cal yr BP), an overlying Transitional Pollen Zone (ca. 17,000–11,500 cal yr BP), and an Interglacial Pollen Zone (ca. 11,500 cal yr BP to present). Another Q-mode cluster analysis, of both the background mud and flow deposits, also defined these three pollen zones, but four of the 13 turbiditic deposits were assigned to pollen zones older than expected by their stratigraphic position. This was due to these samples containing statistically significant fewer palynomorphs than the background muds as well as being enriched (∼10–35% in some cases) in hydraulically-efficient Pinus pollen. A selective bias in the pollen assemblage, such as demonstrated here, may result in incorrect interpretations (e.g., climatic shifts or environmental perturbations) based on the floral record, indicating turbiditic deposits should be avoided in marine palynological studies. Particularly in the case of fine-grained flow deposits that may not be visually distinct, granulometry and grain size frequency distribution curves may not be enough to identify these biased deposits. Determining the relative abundance and source of displaced shallow-water benthic foraminifera entrained in these sediments serves as an excellent

Stable isotope evidence for formation from magmatic fluids of the mineralized breccias in the Los Bronces and El Teniente copper deposits, Central Chile

International Nuclear Information System (INIS)

Skewes, M.A; Arevalo, A; Holmgren, C.; Stern, C.R

2001-01-01

The giant Miocene and Pliocene Rio Blanco-Los Bronces (Warnaars et al., 1985; Serrano et al., 1996; Vargas et al., 1999) and El Teniente (Camus, 1975; Cuadra, 1986; Skewes and Arevalo, 2000) copper deposits of central Chile are among the largest copper deposits in the world. Hypogene copper ore is more significant than supergene ore in these deposits, and most of the hypogene copper occurs in the matrix of multiple clusters of breccias (Skewes and Stern, 1994; 1995). The origin of the large mineralized breccia pipes in these and other Andean copper deposits has been attributed to the explosive expansion of magmatic aqueous fluids derived from cooling plutons (Emmons, 1938; Kents, 1964; Warnaars et al., 1985; Sillitoe, 1985; Skewes and Stern, 1994, 1995). Warnaars et al. (1985) and Skewes and Stern (1996) suggested that mineral deposition in the matrix of these breccias took place by the rapid cooling of the same magmatic fluids that generated the brecciation. Highly saline, high-temperature magmatic fluid inclusions occur in quartz and tourmaline in the matrix of these breccias (Holmgren et al., 1988; Vargas et al., 1999; Skewes et al., 2001) (au)

Dimensional Modeling By Using a New Response to Slowly Changing Dimensions

DEFF Research Database (Denmark)

Frank, L.; Frank, C.; Jensen, Christian Søndergaard

2005-01-01

solutions/responses to handling the aggregation problems caused by slowly changing dimensions. In this paper, we will describe a fourth solution. A special aspect of our new response is that it should be used before the other responses, as it will change the design of the data warehouse. Afterwards, it may...

Atmospheric deposition and soil vertical distribution of {sup 7}Be in a semiarid region of central Argentina

Energy Technology Data Exchange (ETDEWEB)

Lohaiza, Flavia A.; Velasco, Hugo; Ayub, Jimena Juri; Rizzotto, Marcos; Valladares, Diego L. [Grupo de Estudios Ambientales, Instituto de Matematica Aplicada San Luis, Universidad Nacional de San Luis - CONICET, Ejercito de los Andes 950, D5700HHW San Luis (Argentina)

2014-07-01

Beryllium-7 is a potentially powerful tracer of soil erosion but poor information on {sup 7}Be atmospheric deposition and associated soil inventories in a semiarid region of Central Argentina exists. We estimated the {sup 7}Be atmospheric wet deposition and {sup 7}Be inventory in undisturbed soils north of the City of San Luis (S 33 deg. 9'; W 66 deg. 16') and explored its seasonal variation. Rain and soil samples were collected during 2006-2008 and 2009-2012, respectively. The atmospheric wet deposition was estimated considering both the mean activity concentration in rainwater and the precipitation regime of the region. Using the assessed monthly wet deposition of {sup 7}Be, the expected {sup 7}Be areal activity in soil was estimated applying a simple model. These estimated values were confronted with the experimental measurements in soil. The {sup 7}Be rainwater activity concentration ranged from 0.7 to 3.2 Bq l{sup -1}, with a mean of 1.7 Bq l{sup -1} (sd = 0.53 Bq l{sup -1}). A good linear relationship between {sup 7}Be wet deposition and rain magnitude was obtained (R=0.92, p<0.0001). The wet deposition on soil ranged from 1.1 to 120 Bq m{sup -2} with a mean value of 32.7 Bq m-2 (sd = 29.9 Bq m-2). The annual depositional flux was estimated at 1140 ± 120 Bq m{sup -2} y{sup -1}. The {sup 7}Be mass activity (Bq kg{sup -1}) values in soil samples in the wet period (November-April) were higher than in the dry period (May-October). A typical decreasing exponential function of {sup 7}Be areal activity (Bq m{sup -2}) with soil mass depth (kg m{sup -2}) was found and the distribution parameters for each month were determined. The minimum value of areal activity was 51 Bq m{sup -2} in August, reaching the maximum of 438 Bq m{sup -2} in February. The relaxation mass depth ranged from 2.9 kg m{sup -2} in March to 1.3 kg m{sup -2} in August. The confrontation of experimental measurements in soil with the estimated values using the model showed a good agreement

Assessment of the slowly-imploding liner (LINUS) fusion reactor concept

International Nuclear Information System (INIS)

Miller, R.L.; Krakowski, R.A.

1980-01-01

Prospects for the slowly-imploding liner (LINUS) fusion reactor concept are reviewed. The concept envisages the nondestructive, repetitive and reversible implosion of a liquid-metal cylindrical annulus (liner) onto field-reversed DT plasmoids. Adiabatic heating of the plasmoid to ignition at ultra-high magnetic fields results in a compact, high power density fusion reactor with unique solutions to several technological problems and potentially favorable economics

Computations of slowly moving shocks

International Nuclear Information System (INIS)

Karni, S.; Canic, S.

1997-01-01

Computations of slowly moving shocks by shock capturing schemes may generate oscillations are generated already by first-order schemes, but become more pronounced in higher-order schemes which seem to exhibit different behaviors: (i) the first-order upwind (UW) scheme which generates strong oscillations and (ii) the Lax-Friedrichs scheme which appears not to generate any disturbances at all. A key observation is that in the UW case, the numerical viscosity in the shock family vanishes inside the slow shock layer. Simple scaling arguments show the third-order effects on the solution may no longer be neglected. We derive the third-order modified equation for the UW scheme and regard the oscillatory solution as a traveling wave solution of the parabolic modified equation for the perturbation. We then look at the governing equation for the perturbation, which points to a plausible mechanism by which postshock oscillations are generated. It contains a third-order source term that becomes significant inside the shock layer, and a nonlinear coupling term which projects the perturbation on all characteristic fields, including those not associated with the shock family. 5 refs., 8 figs

Surface vertical deposition for gold nanoparticle film

International Nuclear Information System (INIS)

Diao, J J; Qiu, F S; Chen, G D; Reeves, M E

2003-01-01

In this rapid communication, we present the surface vertical deposition (SVD) method to synthesize the gold nanoparticle films. Under conditions where the surface of the gold nanoparticle suspension descends slowly by evaporation, the gold nanoparticles in the solid-liquid-gas junction of the suspension aggregate together on the substrate by the force of solid and liquid interface. When the surface properties of the substrate and colloidal nanoparticle suspension define for the SVD, the density of gold nanoparticles in the thin film made by SVD only depends on the descending velocity of the suspension surface and on the concentration of the gold nanoparticle suspension. (rapid communication)

Bactericidal effects of antibiotics on slowly growing and nongrowing bacteria.

OpenAIRE

Eng, R H; Padberg, F T; Smith, S M; Tan, E N; Cherubin, C E

1991-01-01

Antimicrobial agents are most often tested against bacteria in the log phase of multiplication to produce the maximum bactericidal effect. In an infection, bacteria may multiply less optimally. We examined the effects of several classes of antimicrobial agents to determine their actions on gram-positive and gram-negative bacteria during nongrowing and slowly growing phases. Only ciprofloxacin and ofloxacin exhibited bactericidal activity against nongrowing gram-negative bacteria, and no antib...

Upper Cenozoic deposits of the central Delmarva Peninsula, Maryland and Delaware

Science.gov (United States)

Owens, James Patrick; Denny, Charles Storrow

1979-01-01

The surface and shallow subsurface sediments of the lower Delmarva Peninsula include beds ranging in age from Miocene to Holocene. The oldest beds appear to be typical shelf deposits of the Chesapeake Group (Calvert-Choptank age). These marine units are overlain by deltaic deposits, which range from fluviatile facies in the north (Pensauken Formation) to marginal marine and marine beds in the south ('Yorktown(?) and Cohansey(?)' Formations as used by Rasmussen and Slaughter in 1955). This large deltaic mass underlies most of the Delmarva Peninsula. Fossil age determinations supplemented by some radiometric dates indicate the delta to be largely late Miocene in age. The nonmarine facies of the delta, the Pensauken Formation, previously was considered to be Pleistocene in age. The late Miocene delta and possibly the Yorktown Formation (lower to middle Pliocene) are overlain by a feldspathic sand, the Beaverdam, which is at least in part marginal marine. Microflora recovered from this formation include species no longer indigenous to the Delmarva region ('exotics'). On the basis of existing information, microfloral assemblages containing 'exotics' are pre-Pleistocene in age. The Beaverdam therefore is pre-Pleistocene in age, probably late Pliocene. A highly dissected and weathered unit, the Walston Silt, caps the uplands of the central Delmarva Peninsula, where it overlies the Beaverdam. The Walston has a microflora containing 'exotics' and therefore is considered to be the youngest Tertiary unit (uppermost Pliocene) in this area. Sediments forming a barrier-back-barrier sequence fringe most of the southern Maryland-Delaware part of the Delmarva Peninsula and are found at altitudes of as much as 15 m (50 ft) above sea level. This sequence, the Omar Formation, is Sangamon in age and has been dated radiometrically as 60,000 to about 100,000 years old. The microflora in these beds contains no 'exotics,' and the assemblage suggests a warm-temperate environment. The Omar

On the dynamics of slowly rotating stellar systems

International Nuclear Information System (INIS)

Davoust, E.

1989-01-01

Kinematical observations are now available for stellar systems which might rotate slowly. The study of periodic orbits in model stellar systems shows that a mean motion in epicyclic or circular orbits contributes to balance the centrifugal force, in addition to the velocity dispersions. Two dynamical models, the generalized Toomre and Plummer models, are adapted to the case of slow rotation. They are applied to two globular clusters, M 3 and 47 Tucanae, and 12 clusters of galaxies. 47 Tucanae is found to rotate, but none of the clusters of galaxies has any significant mean motion, except SC 316-44. 34 refs., 1 fig., 3 tabs. (author)

Organic petrology and geochemistry of Eocene Suzak bituminous marl, north-central Afghanistan: Depositional environment and source rock potential

Science.gov (United States)

Hackley, Paul C.; Sanfilipo, John

2016-01-01

Organic geochemistry and petrology of Eocene Suzak bituminous marl outcrop samples from Madr village in north-central Afghanistan were characterized via an integrated analytical approach to evaluate depositional environment and source rock potential. Multiple proxies suggest the organic-rich (TOC ∼6 wt.%) bituminous marls are ‘immature’ for oil generation (e.g., vitrinite Ro  1) indicating organic input from marine algae and/or bacterial biomass, and sterane/hopane ratios are low (0.12–0.14). Monoaromatic steroids are dominated by C28clearly indicating a marine setting. High gammacerane index values (∼0.9) are consistent with anoxia stratification and may indicate intermittent saline-hypersaline conditions. Stable C isotope ratios also suggest a marine depositional scenario for the Suzak samples, consistent with the presence of marine foraminifera including abundant planktic globigerinida(?) and rare benthic discocyclina(?) and nummulites(?). Biomarker 2α-methylhopane for photosynthetic cyanobacteria implies shallow photic zone deposition of Madr marls and 3β-methylhopane indicates presence of methanotrophic archaea in the microbial consortium. The data presented herein are consistent with deposition of Suzak bituminous marls in shallow stratified waters of a restricted marine basin associated with the southeastern incipient or proto-Paratethys. Geochemical proxies from Suzak rock extracts (S content, high polar content, C isotopes, normal (αααR) C27–29 steranes, and C29/C30 and C26/C25 hopane ratios) are similar to extant data from Paleogene oils produced to the north in the Afghan-Tajik Basin. This observation may indicate laterally equivalent strata are effective source rocks as suggested by previous workers; however, further work is needed to strengthen oil-source correlations.

Slowly varying dilaton cosmologies and their field theory duals

International Nuclear Information System (INIS)

Awad, Adel; Das, Sumit R.; Ghosh, Archisman; Oh, Jae-Hyuk; Trivedi, Sandip P.

2009-01-01

We consider a deformation of the AdS 5 xS 5 solution of IIB supergravity obtained by taking the boundary value of the dilaton to be time dependent. The time dependence is taken to be slowly varying on the anti-de Sitter (AdS) scale thereby introducing a small parameter ε. The boundary dilaton has a profile which asymptotes to a constant in the far past and future and attains a minimum value at intermediate times. We construct the supergravity (sugra) solution to first nontrivial order in ε, and find that it is smooth, horizon-free, and asymptotically AdS 5 xS 5 in the far future. When the intermediate values of the dilaton becomes small enough the curvature becomes of order the string scale and the sugra approximation breaks down. The resulting dynamics is analyzed in the dual SU(N) gauge theory on S 3 with a time dependent coupling constant which varies slowly. When Nε 5 xS 5 again. When Nε>>1, we formulate a classical adiabatic perturbation theory based on coherent states which arises in the large N limit. For large values of the 't Hooft coupling this reproduces the supergravity results. For small 't Hooft coupling the coherent state calculations become involved and we cannot reach a definite conclusion. We argue that the final state should have a dual description which is mostly smooth AdS 5 space with the possible presence of a small black hole.

Main types and metallogenetic characteristics of sandstone-type uranium deposits in central asian mobile belt and its neighbouring area, and the study on prospecting direction of northwest China

International Nuclear Information System (INIS)

Fu Chengming

2007-01-01

Based on the study of geotectonic setting, formation evolution model and metallogenic characteristics of uranium productive basins, important sandstone-type uranium deposits in Central Asian mobile belt and neighbouring area are divided into five types. The statial distribution pattern of different sandstone-type uranium deposits is analyzed in detail. Geotectonic setting and metallogenetic characteristics are discussed. Finally, the characteristics of basin geodynamics, prospecting type and ore-bearing stratigraphy in Northwest China have been proposed. (authors)

Hydrothermal processes in the Edmond deposits, slow- to intermediate-spreading Central Indian Ridge

Science.gov (United States)

Cao, Hong; Sun, Zhilei; Zhai, Shikui; Cao, Zhimin; Jiang, Xuejun; Huang, Wei; Wang, Libo; Zhang, Xilin; He, Yongjun

2018-04-01

The Edmond hydrothermal field, located on the Central Indian Ridge (CIR), has a distinct mineralization history owing to its unique magmatic, tectonic, and alteration processes. Here, we report the detailed mineralogical and geochemical characteristics of hydrothermal metal sulfides recovered from this area. Based on the mineralogical investigations, the Edmond hydrothermal deposits comprise of high-temperature Fe-rich massive sulfides, medium-temperature Zn-rich sulfide chimney and low-temperature Ca-rich sulfate mineral assemblages. According to these compositions, three distinctive mineralization stages have been identified: (1) low-temperature consisting largely of anhydrite and pyrite/marcasite; (2) medium-high temperature distinguished by the mineral assemblage of pyrite, sphalerite and chalcopyrite; and (3) low-temperature stage characterized by the mineral assemblage of colloidal pyrite/marcasite, barite, quartz, anglesite. Several lines of evidence suggest that the sulfides were influenced by pervasive low-temperature diffuse flows in this area. The hydrothermal deposits are relatively enriched in Fe (5.99-18.93 wt%), Zn (2.10-10.00 wt%) and Ca (0.02-19.15 wt%), but display low Cu (0.28-0.81 wt%). The mineralogical varieties and low metal content of sulfides in the Edmond hydrothermal field both indicate that extensive water circulation is prevalent below the Edmond hydrothermal field. With regard to trace elements, the contents of Pb, Ba, Sr, As, Au, Ag, and Cd are significantly higher than those in other sediment-starved mid-ocean ridges, which is indicative of contribution from felsic rock sources. Furthermore, the multiphase hydrothermal activity and the pervasive water circulation underneath are speculated to play important roles in element remobilization and enrichment. Our findings deepen our understanding about the complex mineralization process in slow- to intermediate-spreading ridges globally.

Nitrogen excess in slowly-rotating beta Cephei stars: deep mixing or diffusion?

NARCIS (Netherlands)

Morel, T.; Butler, K.; Aerts, C.C.; Neiner, C.; Briquet, M.

2007-01-01

We present the results of an NLTE abundance study of a small sample of beta Cephei stars, which point to the existence of a population of slowly-rotating B-type pulsators exhibiting a significant amount of nitrogen-enriched material at their surface. Although the origin of this nitrogen excess

Reasons why Plutonium 242 is the best fission chamber deposit to monitor the fast component of a high neutron flux

International Nuclear Information System (INIS)

Filliatre, P.; Oriol, L.; Jammes, C.; Vermeeren, L.

2008-01-01

The FNDS project aims at developing fission chambers to measure on-line the fast component of a high neutron flux (∼10 14 ncm -2 s -1 or more) with a significant thermal component. We identify with simulations the deposits of fission chambers that are best suited to this goal. We address the question of the evolution of the deposit by radiative capture and decay. A deposit of 242 Pu appears as the best choice, with a high initial sensitivity to fast neutrons only slowly degrading under irradiation. The effect of unavoidable impurities was assessed: small concentrations of 241 Pu and 239 Pu can be tolerated

Paleoenvironmental reconstruction of the Oligocene-Miocene deposits of the Tethyan Seaway, Qom Formation, Central Iran

Science.gov (United States)

Dabaghi Sadr, Fatemeh; Schmiedl, Gerhard

2017-04-01

The Cenozoic climate transition from greenhouse to icehouse conditions was associated with major paleogeographic changes in the Tethyan realm. The closure of the Tethyan Seaway and its Iranian gateways during the terminal Paleogene and early Neogene, between approximately 28 and 18 million years, influenced the latitudinal exchange of water masses and energy and is documented in sediment successions of the Qom formation in central Iran. Little is known on the spatial expression and the exact depositional histories of the Qom Formation on orbital time-scales, including a lack of quantitative sea-level reconstructions and studies on the impact of climatic and tectonic changes on marine ecosystems and sedimentation processes. The PhD project focuses on the investigation of lithostratigraphy, biostratigraphy, paleoecology and paleoenvironmental evolution of the Iranian gateways based on late Oligocene to early Miocene foraminiferal faunas and carbonate facies from selected sediment sections of the Qom Basin. The Qom Formation was deposited in the Central Iranian back-arc basin during the Oligocene-Miocene. In this study foraminiferal faunas and carbonate microfacies were studied based on total 191 samples of two section of Qom Formation. One of them is Molkabad section, which is located northwest of Molkabad mountains, southeast of Garmsar. The section mainly consists of limestones, calcareous marls, marls, and gypsum-bearing marls with a total thickness of 760 meters. The Qom Formation at Molkabad section overlies Eocene rocks with an unconformity and consists of the following lithostratigraphic units (from the lower to upper part): Lithothamnium Limestone, Lower Marl Limestone, Bryozoa Limestone, and Upper Marl Group. The Molkabad fault separates the Qom Formation from the overlying Upper Red Formation. The other section is located at Navab anticline in Qom Formation .The section mainly consist of limestone, marl, and gypsum with a total thickness of 318 meters Navab

When a Slowly Rotating Aquaplanet is Coupled to a Dynamical Ocean

Science.gov (United States)

Salameh, J.; Marotzke, J.

2017-12-01

Planets orbiting in close distance from their stars have a high probability to be detected, and are expected to be slowly rotating due to strong tidal forces. By increasing the rotation period from 1 Earth-day to 365 Earth-days, we previously found that the global-mean surface temperature of an aquaplanet with a static mixed-layer ocean decreases by up to 27 K. The cooling is attributed to an increase of the planetary albedo with the rotation period, which is associated with the different distributions of the sea ice and the deep convective clouds. However, we had there assumed a fixed mixed-layer depth and a zero oceanic heat transport in the aquaplanet configuration. The limitations of these assumptions in such exotic climates are still unclear. We therefore perform coupled atmosphere-ocean aquaplanet simulations with the general circulation model ICON for various rotation periods ranging from 1 Earth-day to 365 Earth-days. We investigate how the underlying oceanic circulation modifies the mean climate of slowly rotating aquaplanets, and whether the day-to-night oceanic heat transport reduces the surface-temperature gradients and the sea-ice extent.

Polyurethanes Crosslinked with Poly(vinyl alcohol as a Slowly-Degradable and Hydrophilic Materials of Potential Use in Regenerative Medicine

Directory of Open Access Journals (Sweden)

Justyna Kucińska-Lipka

2018-02-01

Full Text Available Novel, slowly-degradable and hydrophilic materials with proper mechanical properties and surface characteristics are in great demand within the biomedical field. In this paper, the design, synthesis, and characterization of polyurethanes (PUR crosslinked with poly(vinyl alcohol (PVA as a new proposition for regenerative medicine is described. PVA-crosslinked PURs were synthesized by a two-step polymerization performed in a solvent (dimethylsulfoxide, DMSO. The raw materials used for the synthesis of PVA-crosslinked PURs were poly(ε-caprolactone (PCL, 1,6-hexamethylene diisocyanate (HDI, and PVA as a crosslinking agent. The obtained materials were studied towards their physicochemical, mechanical, and biological performance. The tests revealed contact angle of the materials surface between 38–47° and tensile strength in the range of 41–52 MPa. Mechanical characteristics of the obtained PURs was close to the characteristics of native human bone such as the cortical bone (TSb = 51–151 MPa or the cancellous bone (TSb = 10–20 MPa. The obtained PVA-crosslinked PURs did not show significant progress of degradation after 3 months of incubation in a phosphate-buffered saline (PBS. Accordingly, the obtained materials may behave similar to slowly-degradable materials, which can provide long-term physical support in, for example, tissue regeneration, as well as providing a uniform calcium deposition on the material surface, which may influence, for example, bone restoration. A performed short-term hemocompatibility study showed that obtained PVA-crosslinked PURs do not significantly influence blood components, and a cytotoxicity test performed with the use of MG 63 cell line revealed the great cytocompatibility of the obtained materials. According to the performed studies, such PVA-crosslinked PURs may be a suitable proposition for the field of tissue engineering in regenerative medicine.

Facies volcánicas del depósito de avalancha de detritos del volcán Tata Sabaya, Andes Centrales Volcanic facies of the debris avalanche deposit of Tata Sabaya Volcano, Central Andes

Directory of Open Access Journals (Sweden)

Benigno Godoy

2012-09-01

evolution of a volcano. These flows are formed by edifice instability, which could be due to several factors such as the presence of hydrother-mally altered areas, climatic changes, earthquakes, shallow magma intrusions (cryptodomes and/or dykes and/or fault activity beneath or close to the volcano. The final product of this avalanche flow, known as debris avalanche deposit (DAD shows typical hummocky and closed drainage morphologies. More than 14 volcanic centers of the Central Andes have volcanic DAD's, being Tata Sabaya (Bolivia one of them. The collapse that has originated the deposit could have been generated by a combination of magmatic and seismic activity in the volcano. The deposit associated to the partial collapse of Tata Sabaya volcano is distributed on its lower southern flank and partially fills the north-western part of the Salar de Coipasa basin. The deposit covers a minimum area of 230 km² and has an estimated minimum volume of 6±1 km³. The deposit is formed by 6 different types of hummocks, according to their compositions: lavic, pyroclastic, sedimentary, mixed, pyroclastic breccia and basaltic-andesitic hummocks. Based on the predominant hummock type and the spatial distribution, the deposit has been divided into 6 different facies (Toreva Block Facies, Volcanic Hummocks Facies, Central Facies, Sedimentary Hummocks Facies, Mixed Facies and Pyroclastic Breccia Hummocks Facies. Taking into account the facies distribution and their characteristics, we infer the pre-collapse structure of the volcano.

Sedimentology and Palynostratigraphy of a Pliocene-Pleistocene (Piacenzian to Gelasian) deposit in the lower Negro River: Implications for the establishment of large rivers in Central Amazonia

Science.gov (United States)

Soares, Emílio Alberto Amaral; D'Apolito, Carlos; Jaramillo, Carlos; Harrington, Guy; Caputo, Mario Vicente; Barbosa, Rogério Oliveira; Bonora dos Santos, Eneas; Dino, Rodolfo; Gonçalves, Alexandra Dias

2017-11-01

The Amazonas fluvial system originates in the Andes and runs ca. 6700 km to the Atlantic Ocean, having as the main affluent the Negro River (second largest in water volume). The Amazonas transcontinental system has been dated to the late Miocene, but the timing of origin and evolutionary processes of its tributaries are still poorly understood. Negro River alluvial deposits have been dated to the middle to late Pleistocene. Recently, we studied a number of boreholes drilled for the building of a bridge at the lower course of the Negro River. A thin (centimetric) sedimentary deposit was found, laterally continuous for about 1800 m, unconformably overlaying middle Miocene strata and unconformably overlain by younger Quaternary deposits. This deposit consists predominantly of brownish-gray sandstones cemented by siderite and with subordinate mudstone and conglomerate beds. Palynological, granulometric, textural and mineralogical data suggest that the initial Negro River aggradation took place in the deep incised valley under anoxic conditions and subsequently along the floodplain, with efficient transport of mixed origin particles (Andean and Amazonic). Angiosperm leaves, wood and pollen are indicative of a tropical continental palaeoenvironment. A well preserved palynoflora that includes Alnipollenites verus, Grimsdalea magnaclavata and Paleosantalaceaepites cingulatus suggests a late Pliocene to early Pleistocene (Piacenzian to Gelasian) age for this unit, which was an age yet unrecorded in the Amazon Basin. These results indicate that by the late Pliocene-early Pleistocene, large scale river activity was occurring in Central Amazonia linking this region with the Andean headwaters, and therefore incompatible with Central Amazonia barriers like the Purus arch.

[The effect of locally injected betamethasone on collagen deposition in benign central airway stenosis].

Science.gov (United States)

Chen, Y F; Xu, D F; Zeng, Y M; Zhang, H P; Yang, D Y; Chen, X Y; Zhang, J

2016-08-01

To assess the effects of locally injected betamethasone on cicatricial tissue hyperplasia in patients with benign central airway stenosis. A prospective study was conducted with 2 treatment modalities: conventional interventional(CI)therapy, and CI combined with local betamethasone injection(LBI). The average optical density value of TGF-β1 and collagen density in the local airway tissues were compared before therapy and 7 d after the CI treatment and the LBI treatment, respectively. Six patients were recruited in this study from May 2013 to June 2015.The results showed significant statistical differences by paired t-test in TGF-β1: 92±38 vs 164±47(t=-7.984, P=0.000)before and after the CI treatment, respectively; 128±45 vs 78±40 (t=10.055, P=0.000)before and after the LBI treatment, respectively. The collagen density was 91 932±59 520 vs 150 252±76 673(t=-8.105, P=0.000) before and after the CI treatment, respectively; 107 024±54 880 vs 114 038±50 772(t=-0.621, P=0.54) before and after the LBI treatment, respectively.Trend comparisons made before and after the treatments showed significant statistical differences in TGF-β1(F=712.139, P=0.000) and in the collagen density (F=261.256, P=0.000)between the CI treatment and the LBI treatment groups. The CI treatment was shown to stimulate the production of TGF-β1 and the deposition of collagen, while the LBI treatment was shown to reduce the production of TGF-β1 and alleviate the deposition of collagen from the stimulation of the CI treatment.

Sequence stratigraphy, sedimentary systems and petroleum plays in a low-accommodation basin: Middle to upper members of the Lower Jurassic Sangonghe Formation, Central Junggar Basin, Northwestern China

Science.gov (United States)

Feng, Youliang; Jiang, Shu; Wang, Chunfang

2015-06-01

The Lower Jurassic Junggar Basin is a low-accommodation basin in northwestern China. Because of low subsidence rates and a warm, wet climate, deposits of the Central subbasin of the Junggar Basin formed from fluvial, deltaic, shallow lake facies. Sequence stratigraphy and sedimentary systems of the Lower Jurassic members of the Sangonghe Formation (J1s) were evaluated by observing cores, interpreting wireline logs and examining seismic profiles. Two third-order sequences were recognized in the strata. The distribution of the sedimentary systems in the systems tracts shows that tectonic movement, paleorelief, paleoclimate and changes in lake level controlled the architecture of individual sequences. During the development of the lowstand systems tract (LST), the intense structural movement of the basin resulted in a significant fall in the water level in the lake, accompanied by rapid accommodation decrease. Braided rivers and their deltaic systems were also developed in the Central Junggar Basin. Sediments carried by braided rivers were deposited on upward slopes of the paleorelief, and braid-delta fronts were deposited on downward slopes. During the transgressive systems tract (TST), the tectonic movement of the basin was quiescent and the climate was warm and humid. Lake levels rose and accommodation increased quickly, shoal lines moved landward, and shore- to shallow-lake deposits, sublacustrine fans and deep-lake facies were deposited in shallow- to deep-lake environments. During the highstand systems tract (HST), the accommodation no longer increased but sediment supply continued, far exceeding accommodation. HST deposits slowly formed in shallow-lake to meandering river delta-front environments. Relatively low rates of structural subsidence and low accommodation resulted in coarse-grained successions that were fining upward. Deposits were controlled by structural movement and paleorelief within the LST to TST deposits in the Central subbasin. Fine- to medium

Radial modes of slowly rotating compact stars in the presence of magnetic field

Energy Technology Data Exchange (ETDEWEB)

Panda, N.R. [Institute of Physics, Bhubaneswar (India); Siksha ' O' Anusandhan University, Bhubaneswar (India); Mohanta, K.K. [Rairangpur College, Rairangpur, Odisha (India); Sahu, P.K. [Institute of Physics, Bhubaneswar (India)

2016-09-15

Compact stars are composed of very high-density hadron matter. When the matter is above nuclear matter density, then there is a chance of different phases of matter such as hadron matter to quark matter. There is a possible phase which, having the quark core surrounded by a mixed phase followed by hadronic matter, may be considered as a hybrid phase inside the stars called hybrid star (HS). The star which consists of only u, d and s quarks is called quark star (QS) and the star which has only hadronic matter is called neutron star (NS). For the equation of state (EOS) of hadronic matter, we have considered the Relativistic Mean Field (RMF) theory and we incorporated the effect of strong magnetic fields. For the EOS of the quark phase we use the simple MIT bag model. We have assumed Gaussian parametrization to make the density dependent for both bag pressure in quark matter and magnetic field. We have constructed the intermediate mixed phase by using the Glendenning conjecture. Eigenfrequencies of radial pulsations of slowly rotating magnetized compact stars (NS, QS, HS) are calculated in a general relativistic formalism given by Chandrasekhar and Friedman. We have studied the effect of central density on the square of the frequencies of the compact stars in the presence of zero and strong magnetic field. (orig.)

Inhalation of uranium nanoparticles: respiratory tract deposition and translocation to secondary target organs in rats.

Science.gov (United States)

Petitot, Fabrice; Lestaevel, Philippe; Tourlonias, Elie; Mazzucco, Charline; Jacquinot, Sébastien; Dhieux, Bernadette; Delissen, Olivia; Tournier, Benjamin B; Gensdarmes, François; Beaunier, Patricia; Dublineau, Isabelle

2013-03-13

Uranium nanoparticles (fuel cycle and during remediation and decommissioning of nuclear facilities. Explosions and fires in nuclear reactors and the use of ammunition containing depleted uranium can also produce such aerosols. The risk of accidental inhalation of uranium nanoparticles by nuclear workers, military personnel or civilian populations must therefore be taken into account. In order to address this issue, the absorption rate of inhaled uranium nanoparticles needs to be characterised experimentally. For this purpose, rats were exposed to an aerosol containing 10⁷ particles of uranium per cm³ (CMD=38 nm) for 1h in a nose-only inhalation exposure system. Uranium concentrations deposited in the respiratory tract, blood, brain, skeleton and kidneys were determined by ICP-MS. Twenty-seven percent of the inhaled mass of uranium nanoparticles was deposited in the respiratory tract. One-fifth of UO₂ nanoparticles were rapidly cleared from lung (T(½)=2.4 h) and translocated to extrathoracic organs. However, the majority of the particles were cleared slowly (T(½)=141.5 d). Future long-term experimental studies concerning uranium nanoparticles should focus on the potential lung toxicity of the large fraction of particles cleared slowly from the respiratory tract after inhalation exposure. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Relative Attitude Estimation for a Uniform Motion and Slowly Rotating Noncooperative Spacecraft

Directory of Open Access Journals (Sweden)

Liu Zhang

2017-01-01

Full Text Available This paper presents a novel relative attitude estimation approach for a uniform motion and slowly rotating noncooperative spacecraft. It is assumed that the uniform motion and slowly rotating noncooperative chief spacecraft is in failure or out of control and there is no a priori rotation rate information. We utilize a very fast binary descriptor based on binary robust independent elementary features (BRIEF to obtain the features of the target, which are rotational invariance and resistance to noise. And then, we propose a novel combination of single candidate random sample consensus (RANSAC with extended Kalman filter (EKF that makes use of the available prior probabilistic information from the EKF in the RANSAC model hypothesis stage. The advantage of this combination obviously reduces the sample size to only one, which results in large computational savings without the loss of accuracy. Experimental results from real image sequence of a real model target show that the relative angular error is about 3.5% and the mean angular velocity error is about 0.1 deg/s.

Accumulation of slowly activating delayed rectifier potassium current (IKs) in canine ventricular myocytes

DEFF Research Database (Denmark)

Stengl, Milan; Volders, Paul G A; Thomsen, Morten Bækgaard

2003-01-01

In guinea-pig ventricular myocytes, in which the deactivation of slowly activating delayed rectifier potassium current (IKs) is slow, IKs can be increased by rapid pacing as a result of incomplete deactivation and subsequent current accumulation. Whether accumulation of IKs occurs in dogs, in which...

Health and health services in Central America.

Science.gov (United States)

Garfield, R M; Rodriguez, P F

1985-08-16

Despite rapid economic growth since World War II, health conditions improved only slowly in most of Central America. This is a result of poor medical, social, and economic infrastructure, income maldistribution, and the poor utilization of health investments. The economic crisis of the 1980s and civil strife have further endangered health in the region. Life expectancy has fallen among men in El Salvador and civil strife has become the most common cause of death in Guatemala, Nicaragua, and El Salvador. Large-scale US assistance has done little to improve conditions, and refugees continue to pour into North America. It is estimated that there are more than a million refugees within Central America, while a million have fled to the United States. Costa Rica and Nicaragua are partial exceptions to this dismal health picture. An effective approach to the many health problems in Central America will require joint planning and cooperation among all countries in the region.

Dust deposition and ambient PM10 concentration in northwest China: Spatial and temporal variability

Science.gov (United States)

Aeolian dust transport and deposition are important geophysical processes which influence global bio-geochemical cycles. Currently, reliable continental deposition data are scarce in central Asia. Located in the eastern part of central Asia, Xinjiang Province of northwestern China has long played a ...

Studies of carbon deposition and consumption on Ru/TiO2 during Fischer-Tropsch synthesis

International Nuclear Information System (INIS)

Yokomizo, G.; Bell, A.T.; Duncan, T.M.

1986-01-01

Isotropic tracer techniques have been used to characterize the dynamics of carbon deposition on the surface of a Ru/TiO 2 catalyst during Fischer-Tropsch synthesis and 13 C-NMR spectroscopy has been used to characterize the structure of the deposited carbon. Elemental carbon, designated C/sub α/ is formed very rapidly, whereas alkyl carbon, designated C/sub β/ accumulates much more slowly. The influence of catalyst reduction on temperature, reaction conditions, and time under reaction conditions on the surface concentrations and reactivity of C/sub α/ and C/sub β/ will be discussed. It will be shown that C/sub β/ progressively becomes less reactive and may be the precursor to the formation of graphitic carbon

Reasons why Plutonium 242 is the best fission chamber deposit to monitor the fast component of a high neutron flux

Energy Technology Data Exchange (ETDEWEB)

Filliatre, P. [CEA, DEN, SPEx/LDCI, F-13108 Saint-Paul-lez-Durance (France); Laboratoire Commun d' Instrumentation CEA-SCK-CEN (France)], E-mail: philippe.filliatre@cea.fr; Oriol, L.; Jammes, C. [CEA, DEN, SPEx/LDCI, F-13108 Saint-Paul-lez-Durance (France); Laboratoire Commun d' Instrumentation CEA-SCK-CEN (France); Vermeeren, L. [SCK-CEN, Boeretang 200, B-2400 Mol (Belgium); Laboratoire Commun d' Instrumentation CEA-SCK-CEN (France)

2008-08-11

The FNDS project aims at developing fission chambers to measure on-line the fast component of a high neutron flux ({approx}10{sup 14}ncm{sup -2}s{sup -1} or more) with a significant thermal component. We identify with simulations the deposits of fission chambers that are best suited to this goal. We address the question of the evolution of the deposit by radiative capture and decay. A deposit of {sup 242}Pu appears as the best choice, with a high initial sensitivity to fast neutrons only slowly degrading under irradiation. The effect of unavoidable impurities was assessed: small concentrations of {sup 241}Pu and {sup 239}Pu can be tolerated.

Angular momentum transport by heat-driven g-modes in slowly pulsating B stars

Science.gov (United States)

Townsend, R. H. D.; Goldstein, J.; Zweibel, E. G.

2018-03-01

Motivated by recent interest in the phenomenon of waves transport in massive stars, we examine whether the heat-driven gravity (g) modes excited in slowly pulsating B (SPB) stars can significantly modify the stars' internal rotation. We develop a formalism for the differential torque exerted by g modes, and implement this formalism using the GYRE oscillation code and the MESASTAR stellar evolution code. Focusing first on a 4.21M⊙ model, we simulate 1 000 yr of stellar evolution under the combined effects of the torque due to a single unstable prograde g mode (with an amplitude chosen on the basis of observational constraints), and diffusive angular momentum transport due to convection, overshooting, and rotational instabilities. We find that the g mode rapidly extracts angular momentum from the surface layers, depositing it deeper in the stellar interior. The angular momentum transport is so efficient that by the end of the simulation, the initially non-rotating surface layers are spun in the retrograde direction to ≈ 30 per cent of the critical rate. However, the additional inclusion of magnetic stresses in our simulations almost completely inhibits this spin-up. Expanding our simulations to cover the whole instability strip, we show that the same general behaviour is seen in all SPB stars. After providing some caveats to contextualize our results, we hypothesize that the observed slower surface rotation of SPB stars (as compared to other B-type stars) may be the direct consequence of the angular momentum transport that our simulations demonstrate.

Quasi-stationary gravitational collapse of slowly rotating bodies in general relativity

Energy Technology Data Exchange (ETDEWEB)

Miller, J C [Oxford Univ. (UK). Dept. of Astrophysics

1977-05-01

This paper presents results of quasi-stationary collapse calculations for a class of slowly rotating non-homogeneous bodies in general relativity. The results are qualitatively similar to those obtained previously for homogeneous models indicating that the effects described for the homogeneous models are likely to have some relevance for the gravitational collapse of real stars towards the black hole state. There is also a discussion of some basic questions associated with such calculations.

Fog deposition fluxes of water and ions to a mountainous site in Central Europe

Science.gov (United States)

Klemm, Otto; Wrzesinsky, Thomas

2007-09-01

Fog and precipitation composition and deposition were measured over a 1-yr period. Ion concentrations were higher in fog than in precipitation by factors of between 6 and 18. The causes of these differences were less dilution of fog water due to non-availability of condensable water vapour, and more efficient transfer of surface emissions to fog water as compared to rain water or snow. Fogwater and dissolved ions depositions were measured with eddy covariance in combination with a bulk fogwater collector. Annual fogwater deposition was 9.4% that of precipitation. The annual deposition of ions through fog was of the same order as that for precipitation. Ammonium, representing local emission sources, had 46% more annual deposition through fog than through precipitation. The fog droplet number and mass size distributions are reported. Fog droplets of 15 μm diameter contribute most to the deposition flux. The variability of processes and parameters contributing to deposition of ions through fog (ion concentrations in fog water, liquid water content in air, fog duration and turbulence) is high.

Uni-directional waves over slowly varying bottom, part II: Deformation of travelling waves

NARCIS (Netherlands)

Pudjaprasetya, S.R.; Pudjaprasetya, S.R.; van Groesen, Embrecht W.C.

1996-01-01

A new Korteweg-de Vries type of equation for uni-directional waves over slowly varying bottom has been derived in Part I. The equation retains the Hamiltonian structure of the underlying complete set of equations for surface waves. For flat bottom it reduces to the standard Korteweg-de Vries

Structural controls and evolution of gold-, silver-, and REE-bearing copper-cobalt ore deposits, Blackbird district, east-central Idaho: Epigenetic origins

Science.gov (United States)

Lund, K.; Tysdal, Russell G.; Evans, Karl V.; Kunk, Michael J.; Pillers, Renee M.

2011-01-01

The Cu-Co ± Au (± Ag ± Ni ± REE) ore deposits of the Blackbird district, east-central Idaho, have previously been classified as Besshi-type VMS, sedex, and IOCG deposits within an intact stratigraphic section. New studies indicate that, across the district, mineralization was introduced into the country rocks as a series of structurally controlled vein and alteration systems. Quartz-rich and biotite-rich veins (and alteration zones) and minor albite and siderite veinlets maintain consistent order and sulfide mineral associations across the district. Both early and late quartz veins contain chalcopyrite and pyrite, whereas intermediate-stage tourmaline-biotite veins host the cobaltite. Barren early and late albite and late carbonate (generally siderite) form veins or are included in the quartz veins. REE minerals, principally monazite, allanite, and xenotime, are associated with both tourmaline-biotite and late quartz veins. The veins are in mineralized intervals along axial planar cleavage, intrafolial foliation, and shears.

Weathering of radionuclides deposited in inhabited areas

International Nuclear Information System (INIS)

Roed, J.; Andersson, K.G.; Togawa, O.

1996-01-01

When determining the long-term consequences of an accidental deposition of radionuclides from a nuclear power plant in an inhabited area it is essential to be able to predict the migration with time of the deposited radiocaesium. Through the years that have passed since the Chernobyl accident occurred in 1986, the weathering effects on deposited radiocaesium on different types of surface in urban, suburban and industrial areas have been followed through six measurement campaigns to the Gaevle area of Sweden. The weathering effects after the Chernobyl accident were also investigated in towns in the Ukraine and in Russia. The radiocaesium level on asphalt and concrete pavements was found to decrease rather rapidly. It was found that the weathering effects over the first decade could be described by a double exponential function. Similar analytical functions were derived for the other urban surfaces. However, the weathering half-lives of radiocaesium on walls and roofs of buildings were found to be much longer. Even in urban centres, the largest contribution to the dose-rate immediately after deposition often comes from the open grassed areas and areas of soil. As the dose-rate from such surfaces usually decreases slowly, depending on the soil type, the relative importance of these surfaces will often increase with time. After a decade, the dose-rate from horizontal pavements will decrease by a factor of 10 or more, but the dose-rate from an area of soil or a roof may only be halved. Correspondingly, the dose-rate from a wall decreases by only 10-20 %. (author)

Smoothing of the Time Structure of Slowly Extracted Beam From Synchrotron by RF-Knock-out Method

International Nuclear Information System (INIS)

Voloshnyuk, A.V.; Bezshyjko, O.A.; Dolinskiy, A.V.; Dolinskij, A.V.

2005-01-01

Results of the study are presented in work on smoothing of the time structure of the bunch, slowly extracted from synchrotron. The numerical algorithm has been designed for study of the influence of the radio-frequency field of the resonator on time structure of the bunch. The numerical algorithm is based on method Monte-Carlo, where particles in the beam have been extracted by means of slow moving to the third-order resonance conditions. Characteristics of the time structure are vastly smoothed when synchrotron oscillations have been used as first experiments showed. Theoretical motivation of the reasons, influencing upon time structure of the slowly extracted beam is explained in given work

The geology and chronology of the Acheulean deposits in the Mieso area (East-Central Ethiopia).

Science.gov (United States)

Benito-Calvo, Alfonso; Barfod, Dan N; McHenry, Lindsay J; de la Torre, Ignacio

2014-11-01

This paper presents the Quaternary sequence of the Mieso area of Central-East Ethiopia, located in the piedmont between the SE Ethiopian Escarpment and the Main Ethiopian Rift-Afar Rift transition sector.In this region, a piedmont alluvial plain is terraced at þ25 m above the two main fluvial courses, the Mieso and Yabdo Rivers. The piedmont sedimentary sequence is divided into three stratigraphic units separated by unconformities. Mieso Units I and II contain late Acheulean assemblages and a weakly consolidated alluvial sequence, consisting mainly of fine sediments with buried soils and, to a lesser degree, conglomerates. Palaeo-wetland areas were common in the alluvial plain, represented by patches of tufas, stromatolites and clays. At present, the piedmont alluvial surface is preserved mainly on a dark brown soil formed at the top of Unit II. Unit III corresponds to a fluvial deposit overlying Unit II, and is defined by sands, silty clays and gravels, including several Later Stone Age (LSA) occurrences. Three fine-grained tephra levels are interbedded in Unit I (tuffs TBI and TA) and II (tuff CB), and are usually spatially-constrained and reworked. Argon/argon (40Ar/39Ar) dating from tuff TA, an ash deposit preserved in a palustrine environment, yielded an age of 0.212 ± 0.016 Ma (millions of years ago). This date places thetop of Unit I in the late Middle Pleistocene, with Acheulean sites below and above tuff TA. Regional correlations tentatively place the base of Unit I around the Early-Middle Pleistocene boundary, Unit II inthe late Middle Pleistocene and within the Late Pleistocene, and the LSA occurrences of Unit III in the LatePleistoceneeHolocene.

Model for analyzing growth kinetics of a slowly growing Mycobacterium sp

International Nuclear Information System (INIS)

Lambrecht, R.S.; Carriere, J.F.; Collins, M.T.

1988-01-01

This report describes a simple method for quantifying viable mycobacteria and for determining generation time. We used statistical models and computer analysis of growth curves generated for the slowly growing mycobacterium Mycobacterium paratuberculosis under controlled conditions to derive a mathematical formula relating the dependent variable, growth, to the independent variables, log10 number of organisms in the inoculum (inoculum size) and incubation time. Growth was measured by a radiometric method which detects 14 CO 2 release during metabolism of a 14 C-labeled substrate. The radiometric method allowed for early detection of growth and detected as few as three viable bacteria. The coefficient of variation between culture vials inoculated with the same number of M. paratuberculosis was 0.083. Radiometric measurements were highly correlated to spectrophotometric and plate count methods for measuring growth (r = 0.962 and 0.992, respectively). The proportion of the total variability explained by the model in a goodness of fit test was 0.9994. Application of the model to broth cultures provided accurate estimates of the number of M. paratuberculosis (standard error = 0.21, log10 scale) and the growth rate (coefficient of variation, 0.03). Generation time was observed to be dependent upon the number of organisms in the inoculum. The model accurately described all phases of growth of M. paratuberculosis and can likely be applied to other slowly growing microorganisms

Delineating slowly and rapidly evolving fractions of the Drosophila genome.

Science.gov (United States)

Keith, Jonathan M; Adams, Peter; Stephen, Stuart; Mattick, John S

2008-05-01

Evolutionary conservation is an important indicator of function and a major component of bioinformatic methods to identify non-protein-coding genes. We present a new Bayesian method for segmenting pairwise alignments of eukaryotic genomes while simultaneously classifying segments into slowly and rapidly evolving fractions. We also describe an information criterion similar to the Akaike Information Criterion (AIC) for determining the number of classes. Working with pairwise alignments enables detection of differences in conservation patterns among closely related species. We analyzed three whole-genome and three partial-genome pairwise alignments among eight Drosophila species. Three distinct classes of conservation level were detected. Sequences comprising the most slowly evolving component were consistent across a range of species pairs, and constituted approximately 62-66% of the D. melanogaster genome. Almost all (>90%) of the aligned protein-coding sequence is in this fraction, suggesting much of it (comprising the majority of the Drosophila genome, including approximately 56% of non-protein-coding sequences) is functional. The size and content of the most rapidly evolving component was species dependent, and varied from 1.6% to 4.8%. This fraction is also enriched for protein-coding sequence (while containing significant amounts of non-protein-coding sequence), suggesting it is under positive selection. We also classified segments according to conservation and GC content simultaneously. This analysis identified numerous sub-classes of those identified on the basis of conservation alone, but was nevertheless consistent with that classification. Software, data, and results available at www.maths.qut.edu.au/-keithj/. Genomic segments comprising the conservation classes available in BED format.

Depositional conditions of the coal-bearing Hirka Formation beneath ...

Indian Academy of Sciences (India)

This work focuses on the relationship between the coal deposition and explosive volcanism of the Miocene basin, NW central Anatolia, Turkey. The coal-bearing Hirka Formation was deposited over the Galatian Andesitic Complex and/or massive lagoonal environments during the Miocene. The investigated lignite is a high ...

Slowly biodegradable organic compounds impact the biostability of non-chlorinated drinking water produced from surface water.

Science.gov (United States)

Hijnen, W A M; Schurer, R; Bahlman, J A; Ketelaars, H A M; Italiaander, R; van der Wal, A; van der Wielen, P W J J

2018-02-01

It is possible to distribute drinking water without a disinfectant residual when the treated water is biologically stable. The objective of this study was to determine the impact of easily and slowly biodegradable compounds on the biostability of the drinking water at three full-scale production plants which use the same surface water, and on the regrowth conditions in the related distribution systems. Easily biodegradable compounds in the drinking water were determined with AOC-P17/Nox during 2012-2015. Slowly biodegradable organic compounds measured as particulate and/or high-molecular organic carbon (PHMOC), were monitored at the inlet and after the different treatment stages of the three treatments during the same period. The results show that PHMOC (300-470 μg C L -1 ) was approximately 10% of the TOC in the surface water and was removed to 50-100 μg C L -1 . The PHMOC in the water consisted of 40-60% of carbohydrates and 10% of proteins. A significant and strong positive correlation was observed for PHMOC concentrations and two recently introduced bioassay methods for slowly biodegradable compounds (AOC-A3 and biomass production potential, BPC 14 ). Moreover, these three parameters in the biological active carbon effluent (BACF) of the three plants showed a positive correlation with regrowth in the drinking water distribution system, which was assessed with Aeromonas, heterotrophic plate counts, coliforms and large invertebrates. In contrast, the AOC-P17/Nox concentrations did not correlate with these regrowth parameters. We therefore conclude that slowly biodegradable compounds in the treated water from these treatment plants seem to have a greater impact on regrowth in the distribution system than easily biodegradable compounds. Copyright © 2017 Elsevier Ltd. All rights reserved.

Atmospheric particle characterization, distribution, and deposition in Xi'an, Shaanxi Province, Central China

International Nuclear Information System (INIS)

Cao Zongze; Yang Yuhua; Lu, Julia; Zhang Chengxiao

2011-01-01

Physical characterization and chemical analysis of settled dusts collected in Xi'an from November 2007 to December 2008 show that (1) dust deposition rates ranged from 14.6 to 350.4 g m -2 yr -1 . The average deposition rate (76.7 g m -2 yr -1 ) ranks the 11th out of 56 dust deposition rates observed throughout the world. The coal-burning power was the major particle source; (2) on average (except site 4), ∼10% of the settled dusts having size 70% having size <30 μm; (3) the concentrations for 20 out of 27 elements analyzed were upto 18 times higher than their soil background values in China. With such high deposition rates of dusts that contain elevated levels of toxic elements, actions should be taken to reduce emission and studies are needed to assess the potential impacts of settled particles on surface ecosystem, water resource, and human health in the area. - Research highlights: → High atmospheric dust deposition rate in Xi'an, Shaanxi, China. → Coal-burning power plan being a major source of particulate matter in Xi'an area. → High levels of toxic elements in the settled dusts. → Enrichment of heavy metals (e.g., Pb, Ni, Cu) in fine particles. - Atmospheric dust deposition rate is high and the levels of toxic elements associated with the settled dusts are elevated in Xi'an, Shaanxi, China.

Charge-collection efficiency of GaAs field effect transistors fabricated with a low temperature grown buffer layer: dependence on charge deposition profile

International Nuclear Information System (INIS)

McMorrow, D.; Knudson, A.R.; Melinger, J.S.; Buchner, S.

1999-01-01

The results presented here reveal a surprising dependence of the charge-collection efficiency of LT GaAs FETs (field effect transistors) on the depth profile of the deposited charge. Investigation of the temporal dependence of the signal amplitude, carrier density contours, and potential contours reveals different mechanisms for charge collection arising from carriers deposited above and below the LT GaAs buffer layer, respectively. In particular, carriers deposited below the LT GaAs buffer layer dissipate slowly and give rise to a persistent charge collection that is associated with a bipolar-like gain process. These results may be of significance in understanding the occurrence of single-event upsets from protons, neutrons, and large-angle, glancing heavy-ion strikes. (authors)

LH Dynamics in Overweight Girls with Premature Adrenarche and Slowly Progressive Sexual Precocity

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Rosenfield RobertL

2010-08-01

Full Text Available Background. Excess adiposity and premature adrenarche (PA are risk factors for the development of polycystic ovary syndrome (PCOS. Methods. Girls with slowly progressive precocious breast development, who were overweight and had PA (SPPOPA, 6.2–8.2 years, , overweight PA (6.6–10.8 years, , and overweight premenarcheal controls (OW-PUB, 10.6–12.8 years, underwent hormonal sleep testing and GnRH agonist (GnRHag and ACTH tests. Results. Despite an insignificant sleep-related increase in LH and prepubertal baseline hormone levels, SPPOPA peak LH and estradiol responses to GnRHag were intermediate between those of PA and OW-PUB, the LH being significantly different from both. Conclusions. GnRHag tests indicate that SPPOPA is a slowly progressive form of true puberty with blunted LH dynamics. These results argue against the prepubertal hyperandrogenism of excess adiposity or PA enhancing LH secretion or causing ovarian hyperandrogenism prior to menarche. Excess adiposity may contribute to both the early onset and slow progression of puberty.

Depósitos corneales de ciprofloxacino Corneal deposits of ciprofloxacin

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Taimi Cárdenas Díaz

2010-01-01

Full Text Available Las fluoroquinolonas son ampliamente utilizadas para el tratamiento de infecciones oculares bacterianas, ya que tienen actividad tanto para grampositivos, como para gramnegativos. Son fármacos seguros, pero se han descrito depósitos blancos cristalinianos en pacientes con administración frecuente y prolongada;en la mayoría de los casos, ellos resuelven de forma lenta al interrumpir el tratamiento. Si esto no ocurre, los depósitos se deben desbridar. Se ilustran 3 casos operados de catarata que llevaron tratamiento con ciprofloxacino en el posoperatorio, en los cuales se presentaron depósitos corneales y aunque disminuyó la agudeza visual, esta se recuperó después de la queratectomía.Fluoroquinolones are broadly used for the treatment of bacterial ocular infections, since they can act upon both grampositive and gramnegative bacteria. They are safe drugs, but white corneal deposits have been described in patients who frequently take this drug for a long period of time. In most of the cases, the deposits disappear slowly after the treatment is interrupted. If this does not happen, the deposits should be eliminated. Three cases operated on from cataract were presented, who had been taken ciprofloxacin in the postoperative stage and had corneal deposits. Although their visual acuity decreased, it recovered after keratectomy.

Sjogrens Syndrome Presenting with Central Nervous System Involvement

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Tülay Terzi

2012-01-01

Full Text Available Sjogren’s syndrome is a slowly progressive autoimmune disease. Neurological involvement occurs in approximately 20-25% cases in Sjogren’s syndrome. 87% of the neurological involvement is peripheral nervous system, almost 13% in the form of central nervous system involvement. Affected central nervous system may show similar clinical and radiological findings as in multiple sclerosis (MS. In this paper, a 43-year-old patient is discussed who was referred with the complaint of dizziness, there was MS- like lesions in brain imaging studies and was diagnosed with Sjogren’s syndrome. MS- like clinical and radiologic tables can be seen, albeit rarely in Sjogren’s syndrome. In these cases, early diagnosis and early treatment for the sjögren has a great importance for the prognosis of the disease.

Peat - a slowly renewable biofuel

International Nuclear Information System (INIS)

Anon.

2000-01-01

The international investigation group of the Finnish Ministry of Trade and Industry suggest that peat should be classified as a slowly renewable energy source. Regeneration of peat can take up to thousands of years. Hence peat differs from wood energy, classified as renewable energy, and on the other hand from fossil fuels, such as coal. The report of the investigation group includes all the present research information on greenhouse gas balances of Finnish peatlands, i.e. how much greenhouse gases are liberated from Finnish mires, and on the other hand how much greenhouse gases they absorb. The net emissions of greenhouse gases of Finnish mires are over 10 million tons per year, and those of combustion of peat, mainly CO 2 , are over 8 million tons. The total greenhouse gas emissions of peat combustion and Finnish mire are estimated to be 19 (+- 9) % per year. This corresponds to about 25% of the total greenhouse gas emissions in Finland. The objective of the report was also to study the effects of the utilization of cutaway peat production areas (reforestation, returning the areas back to mires, agricultural utilization) on the greenhouse gas emission balances. The precise investigation of the effects of the greenhouse gas balances and the utilization of cutaway areas require further investigation and measurements at Finnish mires. The group consisted of Patrick Crill (USA), Ken Hargraves (GB) and Atte Korhola (FIN). The report of the group will be published in the Studies and Reports Serie of the Finnish Ministry of Trade and Industry both in English and in Finnish

PALEOENVIRONMENTAL RECONSTRUCTION FROM BENTHIC FORAMINIFERAL ASSEMBLAGES OF EARLY HOLOCENE, SHALLOW MARINE DEPOSITS IN GOMBONG, CENTRAL JAVA

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Luli Gustiani

2017-07-01

Full Text Available A 30m-long sediment core covering the Holocene period was taken from the area of Gombong in the southern part of Central Java. The sediments were deposited in a shallow marine to lagoonal environment that was confirmed by the dominance of Ammonia beccarii along the core intervals. In addition, the species Quinqueloculina poeyana, Miliolinella lakemacquariensis, and Miliolinella subrotunda were also found in the sediments that are typical of normal shallow marine conditions. The decrease and increase in the abundance of these species throughout the core is an expression of sea level change in the area, which results the environmental changes. Low sea level is expressed by the dominance of Ammonia beccarii, and the low abundances or absence of the other three species. In contrast, high sea level stands are reflected by the presence of all four species. The high sea level would imply favorable conditions for benthic foraminifera because it would result in normal shallow marine conditions in the area. Finally, from this benthic assemblages study, it can be assumed that the environmental transformation from the originally shallow marine environment into land was occurred at level 5.5m depths of the sediment core, when all benthic foraminifera were terminated, including Ammonia beccarii. These new results from the shallow marine deposits in the Gombong area are a new contribution to the understanding of paleoenvironmental change in the region, which in turn is important for understanding sea level change as well as climate change in the region.

Vyhodnotenie malakofauny z náplavov Neresnice (stredné Slovensko Interpretation of molluscan fauna from the Neresnica River flood deposits (Central Slovakia

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Marek Čiliak

2011-11-01

Full Text Available Sampling of flood debris deposits can be useful method in insufficiently surveyed areas. This sampling method also allows us to detect the presence of rare and endangered species in the study area. We studied flood debris along the Neresnica River to gather data on mollusc fauna of the Pliešovská Kotlina basin and the Javorie Mts. (Central Slovakia. In spring 2010, samples of flood debris were taken at three sites along the river. Molluscan thanatocoenoses were composed of 68 species (56 terrestrial and 12 aquatic ones. The most notable records were two subterranean species – Lucilla scintilla and L. singleyana, and also the species of nature conservation interest – Vertigo angustior. We found representatives of all ecological groups of molluscs, which provide the evidence of ecosystem diversity in various habitats along the river. We documented that the land use of the studied drainage basin was only partially reflected by the structure of mollusc assemblages from flood deposits.

Ground-water resources of north-central Connecticut

Science.gov (United States)

Cushman, Robert Vittum

1964-01-01

The term 'north-central Connecticut' in this report refers to an area of about 640 square miles within the central lowland of the Connecticut River basin north of Middletown. The area is mostly a broad valley floor underlain by unconsolidated deposits of Pleistocene and Recent age which mantle an erosional surface formed on consolidated rocks of pre-Triassic and Triassic age. The mean annual precipitation at Hartford, near the center of the area, is 42.83 inches and is uniformly distributed throughout the year. The average annual streamflow from the area is about 22 inches or about half the precipitation. The consolidated water-bearing formations are crystalline rocks of pre-Triassic age and sedimentary and igneous rocks of the Newark group of Triassic age. The crystalline rocks include the Middletown gneiss, the Maromas granite gneiss, the Glastonbury granite-gneiss of Rice and Gregory (1906), and the Bolton schist which form the basement complex and the Eastern Upland of north-central Connecticut. Enough water for domestic, stock, and small commercial use generally can be obtained from the crystalline rocks. Recoverable ground water occurs in the interconnected joints and fracture zones and is yielded in amounts ranging from 29 to 35 gpm (gallons per minute) to wells ranging in depth from 29 to 550 feet. The sedimentary rocks of Triassic age underlie all the Connecticut River Lowland and are predominantly arkosic sandstone and shale. Water supplies sufficient for domestic, stock, and small commercial use can be obtained from shallow wells penetrating these rocks, and larger supplies sufficient for industries and smaller municipalities can probably be obtained from deeper wells. Reported yields range from ? to 578 gpm; the larger yields are generally obtained from wells between 300 and 600 feet in depth. Yields are larger where the overlying material is sand and gravel or where the rocks are well fractured. The igneous rocks of Triassic age are basalt and have

Sedimentary environments and stratigraphy of the carbonate-silicilastic deposits of the Shirgesht Formation: implications for eustasy and local tectonism in the Kalmard Block, Central Iran

OpenAIRE

reza Mousavi-Harami; aram bayetgoll; asadolah Mahboubi

2015-01-01

Introduction   Sedimentological and sequence stratigraphic analysis providing insight into the main relationships between sequence architecture and stacking pattern, syn/post-depositional tectonics, and eustatic sea-level fluctuations (Gawthorpe and Leeder 2000; Zecchin et al. 2003, 2004; Carpentier et al. 2007). Relative variations in sea level are due to tectonic activity and eustasy. The Shirgesht Formation in the Kalmard Block of Central Iran provides a useful case study for to determine ...

Ethical Leadership Styles of Future Managers in Central and Eastern European Countries

OpenAIRE

Anna Remišová; Anna Lašáková

2013-01-01

There is a limited understanding what the constituent elements of the ethical leadership are. Although various researchers defined ethical leadership as a specific leadership style, with typical personality traits and behaviors, the precise instantiation of the content of ethical leadership was only seldom investigated. The body of empirical research on ethical leadership is only slowly beginning to build up. Furthermore, the ethical leadership in Central and Eastern European countries (CEE c...

Mycobacterium alsiense, a novel, slowly growing species isolated from two patients with pulmonary disease

DEFF Research Database (Denmark)

Richter, Elvira; Tortoli, Enrico; Fischer, Arno

2007-01-01

A previously undescribed, slowly growing Mycobacterium species was isolated from pulmonary specimens of two patients, one from Denmark and one from Italy. The isolates showed unique 16S rRNA internal transcribed spacers and hsp65 sequences: the 16S rRNA was most closely related to Mycobacterium...

Hubble Diagram Test of Expanding and Static Cosmological Models: The Case for a Slowly Expanding Flat Universe

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Laszlo A. Marosi

2013-01-01

Full Text Available We present a new redshift (RS versus photon travel time ( test including 171 supernovae RS data points. We extended the Hubble diagram to a range of z = 0,0141–8.1 in the hope that at high RSs, the fitting of the calculated RS/ diagrams to the observed RS data would, as predicted by different cosmological models, set constraints on alternative cosmological models. The Lambda cold dark matter (ΛCDM, the static universe model, and the case for a slowly expanding flat universe (SEU are considered. We show that on the basis of the Hubble diagram test, the static and the slowly expanding models are favored.

Maps of Quaternary Deposits and Liquefaction Susceptibility in the Central San Francisco Bay Region, California

Science.gov (United States)

Witter, Robert C.; Knudsen, Keith L.; Sowers, Janet M.; Wentworth, Carl M.; Koehler, Richard D.; Randolph, Carolyn E.; Brooks, Suzanna K.; Gans, Kathleen D.

2006-01-01

This report presents a map and database of Quaternary deposits and liquefaction susceptibility for the urban core of the San Francisco Bay region. It supercedes the equivalent area of U.S. Geological Survey Open-File Report 00-444 (Knudsen and others, 2000), which covers the larger 9-county San Francisco Bay region. The report consists of (1) a spatial database, (2) two small-scale colored maps (Quaternary deposits and liquefaction susceptibility), (3) a text describing the Quaternary map and liquefaction interpretation (part 3), and (4) a text introducing the report and describing the database (part 1). All parts of the report are digital; part 1 describes the database and digital files and how to obtain them by downloading across the internet. The nine counties surrounding San Francisco Bay straddle the San Andreas fault system, which exposes the region to serious earthquake hazard (Working Group on California Earthquake Probabilities, 1999). Much of the land adjacent to the Bay and the major rivers and streams is underlain by unconsolidated deposits that are particularly vulnerable to earthquake shaking and liquefaction of water-saturated granular sediment. This new map provides a consistent detailed treatment of the central part of the 9-county region in which much of the mapping of Open-File Report 00-444 was either at smaller (less detailed) scale or represented only preliminary revision of earlier work. Like Open-File Report 00-444, the current mapping uses geomorphic expression, pedogenic soils, inferred depositional environments, and geologic age to define and distinguish the map units. Further scrutiny of the factors controlling liquefaction susceptibility has led to some changes relative to Open-File Report 00-444: particularly the reclassification of San Francisco Bay mud (Qhbm) to have only MODERATE susceptibility and the rating of artificial fills according to the Quaternary map units inferred to underlie them (other than dams - adf). The two colored

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).

Identification of tsunami deposits considering the tsunami waveform: An example of subaqueous tsunami deposits in Holocene shallow bay on southern Boso Peninsula, Central Japan

Science.gov (United States)

Fujiwara, Osamu; Kamataki, Takanobu

2007-08-01

This study proposes a tsunami depositional model based on observations of emerged Holocene tsunami deposits in outcrops located in eastern Japan. The model is also applicable to the identification of other deposits, such as those laid down by storms. The tsunami deposits described were formed in a small bay of 10-20-m water depth, and are mainly composed of sand and gravel. They show various sedimentary structures, including hummocky cross-stratification (HCS) and inverse and normal grading. Although, individually, the sedimentary structures are similar to those commonly found in storm deposits, the combination of vertical stacking in the tsunami deposits makes a unique pattern. This vertical stacking of internal structures is due to the waveform of the source tsunamis, reflecting: 1) extremely long wavelengths and wave period, and 2) temporal changes of wave sizes from the beginning to end of the tsunamis. The tsunami deposits display many sub-layers with scoured and graded structures. Each sub-layer, especially in sandy facies, is characterized by HCS and inverse and normal grading that are the result of deposition from prolonged high-energy sediment flows. The vertical stack of sub-layers shows incremental deposition from the repeated sediment flows. Mud drapes cover the sub-layers and indicate the existence of flow-velocity stagnant stages between each sediment flow. Current reversals within the sub-layers indicate the repeated occurrence of the up- and return-flows. The tsunami deposits are vertically divided into four depositional units, Tna to Tnd in ascending order, reflecting the temporal change of wave sizes in the tsunami wave trains. Unit Tna is relatively fine-grained and indicative of small tsunami waves during the early stage of the tsunami. Unit Tnb is a protruding coarse-grained and thickest-stratified division and is the result of a relatively large wave group during the middle stage of the tsunami. Unit Tnc is a fine alternation of thin sand

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

Deposit Money Creation in Search Equilibrium

OpenAIRE

Keiichiro Kobayashi

2002-01-01

The endogenous creation of bank credit and of deposit money is modeled. If banks have a limited ability to commit to making interbank loans, then, in order for bank deposits to be accepted as liquid assets, an upper bound is placed upon the size of each bank's asset portfolio, where the bound is determined as a certain multiple of the bank's capital. In our search model, the Central Limit Theorem implies that the multiplier is a non-linear function of the aggregate level of bank assets. Thus ...

Dynamics of a slowly evaporating solvent-polymer mixture with a deformable upper surface

KAUST Repository

Hennessy, M. G.

2014-06-17

This paper examines how surface deformations affect the stability of a slowly evaporating solvent-polymer mixture. The destabilizing effect of surface-tension variations arising from evaporation-induced concentration gradients and the counteracting influence of mean gravity and surface tension are incorporated into the mathematical model. A linear stability analysis that takes advantage of the separation between the characteristic time scales of the slowly evolving base state and the perturbations is carried out in combination with numerical solutions of the linearized system. It is shown that the onset of instability can occur for Marangoni numbers that are much lower than the critical value for a non-deformable surface. Moreover, two types of Marangoni instabilities appear in the system: one is associated with the traditional stationary instability, and the other is an oscillatory instability that is not present for a non-deformable liquid surface. A region of the parameter space where the oscillatory instability dominates is identified and used to formulate appropriate conditions for future experiments. © 2014 The authors 2014. Published by Oxford University Press on behalf of the Institute of Mathematics and its Applications. All rights reserved.

Dynamics of a slowly evaporating solvent-polymer mixture with a deformable upper surface

KAUST Repository

Hennessy, M. G.; Munch, A.

2014-01-01

This paper examines how surface deformations affect the stability of a slowly evaporating solvent-polymer mixture. The destabilizing effect of surface-tension variations arising from evaporation-induced concentration gradients and the counteracting influence of mean gravity and surface tension are incorporated into the mathematical model. A linear stability analysis that takes advantage of the separation between the characteristic time scales of the slowly evolving base state and the perturbations is carried out in combination with numerical solutions of the linearized system. It is shown that the onset of instability can occur for Marangoni numbers that are much lower than the critical value for a non-deformable surface. Moreover, two types of Marangoni instabilities appear in the system: one is associated with the traditional stationary instability, and the other is an oscillatory instability that is not present for a non-deformable liquid surface. A region of the parameter space where the oscillatory instability dominates is identified and used to formulate appropriate conditions for future experiments. © 2014 The authors 2014. Published by Oxford University Press on behalf of the Institute of Mathematics and its Applications. All rights reserved.

Mycobacterium arosiense sp. nov., a slowly growing, scotochromogenic species causing osteomyelitis in an immunocompromised child

DEFF Research Database (Denmark)

Bang, D.; Herlin, T.; Stegger, M.

2008-01-01

A yellow-pigmented, scotochromogenic, slowly growing mycobacterial strain, designated T1921(T), was isolated from the disseminated osteomyelitic lesions of a 7-year-old child with an underlying partial gamma interferon receptor alpha-1 deficiency. Hybridization by the line probe assay indicated...

Measurement of the 36Cl deposition flux in central Japan: natural background levels and seasonal variability

International Nuclear Information System (INIS)

Tosaki, Yuki; Tase, Norio; Sasa, Kimikazu; Takahashi, Tsutomu; Nagashima, Yasuo

2012-01-01

Essential parameters for the applications of 36 Cl as a tracer in groundwater studies include the initial 36 Cl/Cl ratio, at the time of recharge, and/or the natural background deposition flux of 36 Cl in the recharge area. To facilitate the hydrological use of 36 Cl in central Japan, this study aimed to obtain a precise estimate of the long-term average local 36 Cl flux and to characterize its seasonal variability. The 36 Cl in precipitation was continuously monitored in Tsukuba, central Japan over a period of >5 years. The 36 Cl flux showed a clear seasonal variation with an annual peak during the spring, which was attributed to the seasonal variability of tropopause height. The long-term average 36 Cl flux (32 ± 2 atoms m −2 s −1 ), estimated from the measured data, was consistent with the prediction from the 36 Cl latitudinal fallout model scaled using the global mean production rate of 20 atoms m −2 s −1 . The initial 36 Cl/Cl ratio was estimated to be (41 ± 6) × 10 −15 , which is similar to that of pre-bomb groundwater in the Tsukuba Upland. An observation period covering an 11-year solar cycle would yield more accurate estimates of the values, given the increased 36 Cl flux during the solar minimum. - Highlights: ► We monitored 36 Cl in precipitation in central Japan over a period of >5 years. ► The 36 Cl flux varied seasonally, with a peak in spring. ► The long-term average 36 Cl flux and the initial 36 Cl/Cl ratio were 32 ± 2 atoms m −2 s −1 and (41 ± 6) × 10 −15 , respectively. ► An observation period covering an 11-year solar cycle would yield more accurate estimates of the values, given the increased 36 Cl flux during the solar minimum.

Reconnaissance for radioactive deposits in Alaska, 1953

Science.gov (United States)

Matzko, John J.; Bates, Robert G.

1955-01-01

During the summer of 1953 the areas investigated for radioactive deposits in Alaska were on Nikolai Creek near Tyonek and on Likes Creek near Seward in south-central Alaska where carnotite-type minerals had been reported; in the headwaters of the Peace River in the eastern part of the Seward Peninsula and at Gold Bench on the South Fork of the Koyukuk River in east-central Alaska, where uranothorianite occurs in places associated with base metal sulfides and hematite; in the vicinity of Port Malmesbury in southeastern Alaska to check a reported occurrence of pitchblende; and, in the Miller House-Circle Hot Springs area of east-central Alaska where geochemical studies were made. No significant lode deposits of radioactive materials were found. However, the placer uranothorianite in the headwaters of the Peace River yet remains as an important lead to bedrock radioactive source materials in Alaska. Tundra cover prevents satisfactory radiometric reconnaissance of the area, and methods of geochemical prospecting such as soil and vegetation sampling may ultimately prove more fruitful in the search for the uranothorianite-sulfide lode source than geophysical methods.

Geologic Map and Engineering Properties of the Surficial Deposits of the Tok Area, East-Central Alaska

Science.gov (United States)

Carrara, Paul E.

2007-01-01

The Tok area 1:100,000-scale map, through which the Alaska Highway runs, is in east-central Alaska about 160 km west of the Yukon border. The surficial geologic mapping in the map area is in support of the 'Geologic Mapping in support of land, resources, and hazards issues in Alaska' Project of the USGS National Cooperative Geologic Mapping Program. The Tok map area contains parts of three physiographic provinces, the Alaska Range, the Yukon-Tanana Upland, and the Northway-Tanana Lowland. The high, rugged, glaciated landscape of the eastern Alaska Range dominates the southwestern map area. The highest peak, an unnamed summit at the head of Cathedral Rapids Creek No. 2, rises to 2166 m. The gently rolling hills of the Yukon-Tanana Upland, in the northern map area, rise to about 1000 m. The Northway-Tanana Lowland contains the valley of the westerly flowing Tanana River. Elevations along the floor of the lowland generally range between 470 and 520 m. The dominant feature within the map is the Tok fan, which occupies about 20 percent of the map area. This large (450 km2), nearly featureless fan contains a high percentage of volcanic clasts derived from outside the present-day drainage of the Tok River. Because the map area is dominated by various surficial deposits, the map depicts 26 different surficial units consisting of man-made, alluvial, colluvial, eolian, lacustrine, organic, glaciofluvial, glacial, and periglacial deposits. The accompanying table provides information concerning the various units including their properties, characteristics, resource potential, and associated hazards in this area of the upper Tanana valley.

The role of social toxicity in responses to a slowly-evolving environmental disaster: the case of amphibole asbestos exposure in Libby, Montana, USA.

Science.gov (United States)

Cline, Rebecca J W; Orom, Heather; Chung, Jae Eun; Hernandez, Tanis

2014-09-01

Experiencing a disaster has significant negative effects on psychological adjustment. Case study accounts point to two consistent trends in slowly-evolving environmental disasters: (a) patterns of negative social dynamics, and (b) relatively worse psychological outcomes than in natural disasters. Researchers have begun to explicitly postulate that the social consequences of slowly-evolving environmental disasters (e.g., community conflict) have their own effects on victims' psychological outcomes. This study tested a model of the relationship between those social consequences and psychological adjustment of victims of a slowly-evolving environmental disaster, specifically those whose health has been compromised by the amphibole asbestos disaster in Libby, MT. Results indicate that experiencing greater community conflict about the disaster was associated with greater family conflict about the disaster which, in turn, was associated with greater social constraints on talking with others about their disease, both directly and indirectly through experiencing stigmatization. Experiencing greater social constraints was associated with worse psychological adjustment, both directly and indirectly through failed social support. Findings have implications for understanding pathways by which social responses create negative effects on mental health in slowly-evolving environmental disasters. These pathways suggest points for prevention and response (e.g., social support, stigmatization of victims) for communities experiencing slowly-evolving environmental disasters.

The ESR age of Portlandia arctica shells from glacial deposits of Central Latvia . an answer to a controversy on the age and genesis of their enclosing sediments

Science.gov (United States)

Molodkov, Anatoly; Dreimanis, Aleksis; ĀBoltiņš, Ojars; Raukas, Anto

The occurrence of Portlandia arctica shells in glacigenic sediments of Central Latvia had created a controversy in many publications about (1) their age ranging from the Holsteinian to the Late Weichselian and (2) the genesis of their enclosing sediments: glacial, glaciomarine or marine. Our reinvestigation of the main object of controversy, the Lı¯čupe site, leads to a conclusion that the sedimentary package of diamictons, clays and sands containing Portlandia arctica shells and marine microfossils is a large glacial raft that had been transported and deposited by the Riga lobe during the Weichselian. The electron spin resonance (ESR) ages on five sets of Portlandia arctica shells from the Lı¯čupe and Daugmales Tomēni sites range from 86.0±6.8 to 105.0±9.2 ka BP. These ESR age determinations and the cool climate indicators of the associated microflora and microfauna suggest that their source sediments, probably in the Gulf of Riga, are marine clays of Early Weichselian age, probably correlative to the Brørup Interstadial. In Central Latvia Portlandia arctica shells and their enclosing clay occur resedimented or translocated in glacial deposits during Weichselian glacial advances.

Optimization of the luminescence emission of Si nanocrystals synthesized from non-stoichiometric Si oxides using a Central Composite Design of the deposition process

International Nuclear Information System (INIS)

Morana, B.; Sande, J.C.G. de; Rodriguez, A.; Sangrador, J.; Rodriguez, T.; Avella, M.; Jimenez, J.

2008-01-01

Si oxide films with a controlled excess of Si were deposited on Si wafers by LPCVD using Si 2 H 6 and O 2 , thermally annealed to 1100 deg. C for 1 h to form Si nanocrystals embedded in SiO 2 and subsequently annealed at 450 deg. C in forming gas. The samples were characterized by Fourier transform infrared spectroscopy, spectroscopic ellipsometry and cathodoluminescence spectroscopy. The excess of Si in the as-deposited samples, ranging from 0 to 70% in volume, was obtained from the ellipsometry data analysis. After annealing at 1100 deg. C, the samples show a luminescence band (peaking at 665 nm) at 80 K and at room temperature which is associated to the presence of Si nanocrystals. The growth rate, the excess of Si incorporated to the films and the intensity of the luminescence band were modelled using a Face-Centered Central Composite Design as a function of the main deposition variables (pressure, 185-300 mTorr; temperature, 250-400 deg. C; Si 2 H 6 /O 2 flow ratio, 2-5) aiming to control the growth process and the incorporation of Si in excess as well as to determine the experimental conditions that yield the samples with the maximum intensity of the luminescence emission

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.

Atmospheric particle characterization, distribution, and deposition in Xi'an, Shaanxi Province, Central China

Energy Technology Data Exchange (ETDEWEB)

Cao Zongze; Yang Yuhua [Key Laboratory of Analytical Chemistry for Life Science of Shaanxi Province, School of Chemistry and Materials Science, Shaanxi Normal University, Xi' an, 710062 (China); Department of Chemistry and Biology, Ryerson University, 350 Victoria Street, Toronto, Ontario, M5B 2K3 (Canada); Lu, Julia, E-mail: julialu@ryerson.c [Department of Chemistry and Biology, Ryerson University, 350 Victoria Street, Toronto, Ontario, M5B 2K3 (Canada); Key Laboratory of Analytical Chemistry for Life Science of Shaanxi Province, School of Chemistry and Materials Science, Shaanxi Normal University, Xi' an, 710062 (China); Zhang Chengxiao, E-mail: cxzhang@snnu.edu.c [Key Laboratory of Analytical Chemistry for Life Science of Shaanxi Province, School of Chemistry and Materials Science, Shaanxi Normal University, Xi' an, 710062 (China)

2011-02-15

Physical characterization and chemical analysis of settled dusts collected in Xi'an from November 2007 to December 2008 show that (1) dust deposition rates ranged from 14.6 to 350.4 g m{sup -2} yr{sup -1}. The average deposition rate (76.7 g m{sup -2} yr{sup -1}) ranks the 11th out of 56 dust deposition rates observed throughout the world. The coal-burning power was the major particle source; (2) on average (except site 4), {approx}10% of the settled dusts having size <2.6, {approx}30% having size <10.5, and >70% having size <30 {mu}m; (3) the concentrations for 20 out of 27 elements analyzed were upto 18 times higher than their soil background values in China. With such high deposition rates of dusts that contain elevated levels of toxic elements, actions should be taken to reduce emission and studies are needed to assess the potential impacts of settled particles on surface ecosystem, water resource, and human health in the area. - Research highlights: High atmospheric dust deposition rate in Xi'an, Shaanxi, China. Coal-burning power plan being a major source of particulate matter in Xi'an area. High levels of toxic elements in the settled dusts. Enrichment of heavy metals (e.g., Pb, Ni, Cu) in fine particles. - Atmospheric dust deposition rate is high and the levels of toxic elements associated with the settled dusts are elevated in Xi'an, Shaanxi, China.

Atmospheric deposition, retention, and stream export of dioxins and PCBs in a pristine boreal catchment

International Nuclear Information System (INIS)

Bergknut, Magnus; Laudon, Hjalmar; Jansson, Stina; Larsson, Anna; Gocht, Tilman; Wiberg, Karin

2011-01-01

The mass-balance between diffuse atmospheric deposition of organic pollutants, amount of pollutants retained by the terrestrial environment, and levels of pollutants released to surface stream waters was studied in a pristine northern boreal catchment. This was done by comparing the input of atmospheric deposition of polychlorinated dibenzo-p-dioxins and furans (PCDD/Fs) and PCBs with the amounts exported to surface waters. Two types of deposition samplers were used, equipped with a glass fibre thimble and an Amberlite sampler respectively. The measured fluxes showed clear seasonality, with most of the input and export occurring during winter and spring flood, respectively. The mass balance calculations indicates that the boreal landscape is an effective sink for PCDD/Fs and PCBs, as 96.0-99.9 % of received bulk deposition was retained, suggesting that organic pollutants will continue to impact stream water in the region for an extended period of time. - Graphical abstract: Display Omitted Highlights: → The fluxes of organic pollutants in a pristine boreal catchment were measured. → Most of the input and export occurred during winter and spring flood. → 96.0-99.9% of received bulk deposition was retained by the landscape. → Organic pollutants will impact boreal stream waters for an extended period of time. - The boreal landscape is effective in retaining diffuse atmospheric deposition of dioxins and PCBs, slowly releasing these pollutants into nearby streams.

In vitro batch fecal fermentation comparison of gas and short-chain fatty acid production using "slowly fermentable" dietary fibers.

Science.gov (United States)

Kaur, Amandeep; Rose, Devin J; Rumpagaporn, Pinthip; Patterson, John A; Hamaker, Bruce R

2011-01-01

Sustained colonic fermentation supplies beneficial fermentative by-products to the distal colon, which is particularly prone to intestinal ailments. Blunted/delayed initial fermentation may also lead to less bloating. Previously, we reported that starch-entrapped alginate-based microspheres act as a slowly fermenting dietary fiber. This material was used in the present study to provide a benchmark to compare to other "slowly fermentable" fibers. Dietary fibers with previous reports of slow fermentation, namely, long-chain inulin, psyllium, alkali-soluble corn bran arabinoxylan, and long-chain β-glucan, as well as starch-entrapped microspheres were subjected to in vitro upper gastrointestinal digestion and human fecal fermentation and measured over 48 h for pH, gas, and short-chain fatty acids (SCFA). The resistant fraction of cooked and cooled potato starch was used as another form of fermentable starch and fructooligosaccharides (FOS) served as a fast fermenting control. Corn bran arabinoxylan and long-chain β-glucan initially appeared slower fermenting with comparatively low gas and SCFA production, but later fermented rapidly with little remaining in the final half of the fermentation period. Long-chain inulin and psyllium had slow and moderate, but incomplete, fermentation. The resistant fraction of cooked and cooled potato starch fermented rapidly and appeared similar to FOS. In conclusion, compared to the benchmark slowly fermentable starch-entrapped microspheres, a number of the purported slowly fermentable fibers fermented fairly rapidly overall and, of this group, only the starch-entrapped microspheres appreciably fermented in the second half of the fermentation period. Consumption of dietary fibers, particularly commercial prebiotics, leads to uncomfortable feelings of bloating and flatulence due to their rapid degradation in our large intestine. This article employs claimed potential slowly fermenting fibers and compares their fermentation rates

Exploration-systems approach to the Copper Mountain area uranium deposits, central Wyoming. National Uranium Resource Evaluation

International Nuclear Information System (INIS)

Sayala, D.; Lindgren, J.; Babcock, L.

1982-09-01

This report presents the results of multidisciplinary investigations of uranium deposits in the Copper Mountain District of central Wyoming. Although the studies on which the report is based began in 1977, work on the project has been discontinuous and was conducted partly by investigators no longer on the project. The project report represents an effort by the authors to compile and interpret the various data and to draw reasonable conclusions. Although an attempt is made to integrate, where possible, the results of different studies (or surveys), the report is organized into individual sections that present methods and results for each approach used. Investigations reported separately include geology, geochemistry, geophysics, and emanometry. These are aimed at characterizing and understanding the Copper Mountain uranium district and aiding in the detection of similar districts. A summary of overall project results, a comparison of the usefulness of individual approaches or combinations of approaches, and conclusions are presented in separate report sections for the project as a whole. All six sections in this report have been abstracted and indexed

The Pulsed Cylindrical Magnetron for Deposition

Science.gov (United States)

Korenev, Sergey

2012-10-01

The magnetron sputtering deposition of films and coatings broadly uses in microelectronics, material science, environmental applications and etc. The rate of target evaporation and time for deposition of films and coatings depends on magnetic field. These parameters link with efficiency of gas molecules ionization by electrons. The cylindrical magnetrons use for deposition of films and coatings on inside of pipes for different protective films and coatings in oil, chemical, environmental applications. The classical forming of magnetic field by permanent magnets or coils for big and long cylindrical magnetrons is complicated. The new concept of pulsed cylindrical magnetron for high rate deposition of films and coating for big and long pipes is presented in this paper. The proposed cylindrical magnetron has azimuthally pulsed high magnetic field, which allows forming the high ionized plasma and receiving high rate of evaporation material of target (central electrode). The structure of proposed pulsed cylindrical magnetron sputtering system is given. The main requirements to deposition system are presented. The preliminary data for forming of plasma and deposition of Ta films and coatings on the metal pipers are discussed. The comparison of classical and proposed cylindrical magnetrons is given. The analysis of potential applications is considered.

Facies distribution, depositional environment, and petrophysical features of the Sharawra Formation, Old Qusaiba Village, Central Saudi Arabia

Science.gov (United States)

Abbas, Muhammad Asif; Kaminski, Michael; Umran Dogan, A.

2016-04-01

The Silurian Sharawra Formation has great importance as it rests over the richest source rock of the Qusaiba Formation in central Saudi Arabia. The Sharawra Formation has four members including Jarish, Khanafriyah, Nayyal, and Zubliyat. The formation mainly consists of sandstone and siltstone with subordinate shale sequences. The lack of published research on this formation requires fundamental studies that can lay the foundation for future research. Three outcrops were selected from the Old Qusaiba Village in Central Saudi Arabia for field observations, petrographical and petrophysical study. Thin section study has been aided by quantitative mineralogical characterization using scanning electron microscopy - energy dispersive spectroscopy and powder x-ray diffraction (XRD) for both minerals, cements, and clay minerals (detrital and authigenic). The outcrops were logged in detail and nine different lithofacies have been identified. The thin section study has revealed the Sharawra Formation to be mainly subarkosic, while the mica content increases near to its contact with the Qusaiba Formation. The XRD data has also revealed a prominent change in mineralogy with inclusion of minerals like phlogopite and microcline with depths. Field observations delineated a prominent thinning of strata as lithofacies correlation clearly shows the thinning of strata in the southwestern direction. The absence of outcrop exposures further supports the idea of southwestern thinning of strata. This is mainly attributed to local erosion and the presence of thicker shale interbeds in the southeastern section, which was probably subjected to more intense erosion than the northwestern one. The Sharawra Formation rests conformably over the thick transgressive shale sequence, deposited during the post glacial depositional cycle. The lowermost massive sandstone bed of the Sharawra Formation represents the beginning of the regressive period. The shale interbeds in the lower part are evidence of

Smectite-zeolite envelope surrounding the Tsukiyoshi uranium deposit, central Japan. A natural analogue study

International Nuclear Information System (INIS)

Utada, Minoru

2003-01-01

The Tsukiyoshi uranium deposit in Gifu Prefecture is the largest one in Japan. It is embedded in lower part of the Mizunami Group of Miocene age. Relating to the existence of this uranium deposit, the constituent minerals in sediments were studied by XRD and SEM, using many drilling cores. The most abundant authigenic mineral is smectite. The amount of smectite increases generally from upper to lower horizons, and a highly smectitized zone is situated around the uranium deposit. Smectitization predominated in mafic glassy grains of sediments, which was probably formed in early burial diagenesis. Zeolites including clinoptilolite-heulandite, mordenite, analcime, chabazite and philipsite are secondly abundant authigenic minerals. They seem to have been formed at early to late diagenetic stages. Opaline silica is rather rare. Carbonate minerals, including calcite, dolomite, siderite and rhodocrosite are common. They may be formed by diagenesis as well. Gypsum and pyrite occur in upper horizons and lower horizons, respectively. In particular, a highly smectitized zone including pyrite probably played an important role for retarding the migration of uranium and as a result keeping the uranium deposit for past one million years. This smectite-zeolite envelope surrounding the Tsukiyoshi uranium deposit is regarded as a natural analogue of the buffer materials surrounding the high-level radioactive waste repository. (author)

Propagation of 3D internal gravity wave beams in a slowly varying stratification

Science.gov (United States)

Fan, Boyu; Akylas, T. R.

2017-11-01

The time-mean flows induced by internal gravity wave beams (IGWB) with 3D variations have been shown to have dramatic implications for long-term IGWB dynamics. While uniform stratifications are convenient both theoretically and in the laboratory, stratifications in the ocean can vary by more than an order of magnitude over the ocean depth. Here, in view of this fact, we study the propagation of a 3D IGWB in a slowly varying stratification. We assume that the stratification varies slowly relative to the local variations in the wave profile. In the 2D case, the IGWB bends in response to the changing stratification, but nonlinear effects are minor even in the finite amplitude regime. For a 3D IGWB, in addition to bending, we find that nonlinearity results in the transfer of energy from waves to a large-scale time-mean flow associated with the mean potential vorticity, similar to IGWB behavior in a uniform stratification. In a weakly nonlinear setting, we derive coupled evolution equations that govern this process. We also use these equations to determine the stability properties of 2D IGWB to 3D perturbations. These findings indicate that 3D effects may be relevant and possibly fundamental to IGWB dynamics in nature. Supported by NSF Grant DMS-1512925.

Re-Os dating of mineralization in Siah Kamar porphyry Mo deposit (NW Iran) and investigating on its temporal relationship with porphyry Cu-Mo deposits in the southern Lesser Caucasus, NW and central Iran

Science.gov (United States)

Simmonds, Vartan; Moazzen, Mohssen; Selby, David

2017-04-01

The Neo-Tethyan basin closure in Iran is characterized by the Urumieh-Dokhtar magmatic arc (UDMA), formed by north-eastward subduction of the Neo-Tethyan oceanic crust during the Alpine orogeny. This belt also coincides with the porphyry copper metallogenic belt of Iran, which hosts many porphyry Cu-Mo deposits (PCDs) and prospects, such as Sungun (NW Iran) and Sarcheshmeh (central Iran). The Siah Kamar porphyry Mo deposit (PMD) is the first discovered porphyry molybdenum deposit on this belt, which is located 10 km west of Mianeh (NW Iran), with 39.2 Mt proved reserves @ 539 ppm Mo and 66.4 Mt probable reserves @ 266 ppm Mo. The host porphyry stock has quartz-monzonitic composition, which intruded the volcanic and pyroclastic rocks of Eocene age. Re content of molybdenites is about 10.44-41.05 ppm which, considering the several tens of ppm concentration, is comparable with porphyry Mo deposits (e.g., Climax in USA), being clearly distinguished from porphyry Cu-Mo deposits. Re-Os dating of molybdenites from this PMD has given model ages between 28.1±0.15 to 29.06±0.2 Ma, and isochron age of 28.0±2.1 Ma, corresponding to the middle Oligocene (upper part of Rupelian). Comparing the ages determined for Siah Kamar PMD with porphyry Cu-Mo mineralizations in the Lesser Caucasus indicates that it is younger than most of the dated PCDs and prospects there, especially those of upper Eocene, while it is a little older than Paragachay and first-stage Kadjaran PCDs [1]. In a regional scale of NW Iran, it shows a narrow overlap with vein-type Cu-Mo-Au mineralizations in Qarachilar (Qaradagh batholith) and is nearly coeval with Haftcheshmeh PCD, indicating that mineralization in the Siah Kamar PMD corresponds to the second porphyry mineralization epoch in NW Iran, proposed by [2]. Meanwhile, mineralization in Siah Kamar is older than all the porphyry Cu-Mo mineralizations along the central and SE parts of the UDMA, except the Bondar Hanza PCD in Kerman zone, which nearly

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

Directory of Open Access Journals (Sweden)

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.

Electric and magnetic mirrors and grating for slowly moving neutral atoms and molecules

International Nuclear Information System (INIS)

Opat, G.I.; Washington Univ., Seattle, WA; Wark, S.J.; Hajnal, J.V.; Cimmino, A.

1990-01-01

Those atoms or molecules which happen to have positive Stark or Zeeman energies (by virtue of their internal quantum state) are repelled by regions of high electrostatic or magnetostatic energy density, respectively. Using electrostatic or magnetostatic fields, which are periodic in a plane, it is possible to construct mirrors and gratings for slowly moving atoms and molecules. The theory of such devices is presented, together with some ideas for their fabrication. 10 refs., 4 figs

Signal shape registration in the JINR synchrophasotron slowly extracted beam parameter control system

International Nuclear Information System (INIS)

Volkov, V.I.; Kulikov, I.I.; Romanov, S.V.

1982-01-01

Signal shape registration in the JINR synchrophasotron slowly estracted beam parameter control system on-line with the ES-1010 computer is described. 32 input signals can be connected to the registrator. The maximum measurement rate of signal shape registration is about 38 kHz. The registrator consists of 32-channel analog multiplexer, 10-bit analog-to-digital converter, 1024-word buffer memory and control circuits. For information representation the colour TV monitor is used

Effect of exercise on deposition and subsequent retention of inhaled particles

International Nuclear Information System (INIS)

Bennett, W.D.; Messina, M.S.; Smaldone, G.C.

1985-01-01

To investigate the effect of exercise and its associated increase in ventilation on the deposition and subsequent retention of inhaled particles, we measured the fractional and regional lung deposition of a radioactively tagged (/sup 99m/Tc) monodisperse aerosol (2.6 microns mass median aerodynamic diam) in normal human subjects at rest and while exercising on a bicycle ergometer. Breath-by-breath deposition fraction (DF) was measured throughout the aerosol exposures by Tyndallometry. Following each exposure gamma camera analysis was used to 1) determine the regional distribution of deposited particles and 2) monitor lung retention for 2.5 h and again at 24 h. We found that DF was unchanged between ventilation at rest (6-10 l/min) and exercise (32-46 l/min). Even though mouth deposition was enhanced with exercise, it was not large enough to produce a significant difference in the deposition fraction of the lung (DFL) between resting and exercise exposures. The central-to-peripheral distribution of deposited aerosol was larger for the exercise vs. resting exposure, reflecting a shift of particle deposition to more central bronchial airways. Apical-to-basal distribution was not different for the two exposures. Retention at 2.5 h and 24 h (R24) was reduced following the exercise vs. the resting exposure, consistent with greater bronchial deposition during exercise. The product of DFL and R24 gave a measure of fractional burden at 24 h (B24), i.e., the fraction of inhaled aerosol residing in the lungs 24 h after exposure. B24 was not significantly different between rest and exercise exposures

COMPARING INDEPENDENT COMPONENT ANALYSIS WITH PRINCIPLE COMPONENT ANALYSIS IN DETECTING ALTERATIONS OF PORPHYRY COPPER DEPOSIT (CASE STUDY: ARDESTAN AREA, CENTRAL IRAN

Directory of Open Access Journals (Sweden)

S. Mahmoudishadi

2017-09-01

Full Text Available The image processing techniques in transform domain are employed as analysis tools for enhancing the detection of mineral deposits. The process of decomposing the image into important components increases the probability of mineral extraction. In this study, the performance of Principal Component Analysis (PCA and Independent Component Analysis (ICA has been evaluated for the visible and near-infrared (VNIR and Shortwave infrared (SWIR subsystems of ASTER data. Ardestan is located in part of Central Iranian Volcanic Belt that hosts many well-known porphyry copper deposits. This research investigated the propylitic and argillic alteration zones and outer mineralogy zone in part of Ardestan region. The two mentioned approaches were applied to discriminate alteration zones from igneous bedrock using the major absorption of indicator minerals from alteration and mineralogy zones in spectral rang of ASTER bands. Specialized PC components (PC2, PC3 and PC6 were used to identify pyrite and argillic and propylitic zones that distinguish from igneous bedrock in RGB color composite image. Due to the eigenvalues, the components 2, 3 and 6 account for 4.26% ,0.9% and 0.09% of the total variance of the data for Ardestan scene, respectively. For the purpose of discriminating the alteration and mineralogy zones of porphyry copper deposit from bedrocks, those mentioned percentages of data in ICA independent components of IC2, IC3 and IC6 are more accurately separated than noisy bands of PCA. The results of ICA method conform to location of lithological units of Ardestan region, as well.

Comparing Independent Component Analysis with Principle Component Analysis in Detecting Alterations of Porphyry Copper Deposit (case Study: Ardestan Area, Central Iran)

Science.gov (United States)

Mahmoudishadi, S.; Malian, A.; Hosseinali, F.

2017-09-01

The image processing techniques in transform domain are employed as analysis tools for enhancing the detection of mineral deposits. The process of decomposing the image into important components increases the probability of mineral extraction. In this study, the performance of Principal Component Analysis (PCA) and Independent Component Analysis (ICA) has been evaluated for the visible and near-infrared (VNIR) and Shortwave infrared (SWIR) subsystems of ASTER data. Ardestan is located in part of Central Iranian Volcanic Belt that hosts many well-known porphyry copper deposits. This research investigated the propylitic and argillic alteration zones and outer mineralogy zone in part of Ardestan region. The two mentioned approaches were applied to discriminate alteration zones from igneous bedrock using the major absorption of indicator minerals from alteration and mineralogy zones in spectral rang of ASTER bands. Specialized PC components (PC2, PC3 and PC6) were used to identify pyrite and argillic and propylitic zones that distinguish from igneous bedrock in RGB color composite image. Due to the eigenvalues, the components 2, 3 and 6 account for 4.26% ,0.9% and 0.09% of the total variance of the data for Ardestan scene, respectively. For the purpose of discriminating the alteration and mineralogy zones of porphyry copper deposit from bedrocks, those mentioned percentages of data in ICA independent components of IC2, IC3 and IC6 are more accurately separated than noisy bands of PCA. The results of ICA method conform to location of lithological units of Ardestan region, as well.

Geology and Mineral Deposits of the Snow Camp-Saxapahaw Area, Central North Carolina

Science.gov (United States)

Schmidt, Robert G.; Gumiel, Pablo; Payas, Alba

2006-01-01

The Snow Camp-Saxapahaw study area, in the Carolina slate belt in the Southeastern United States, is notable for large zones of high-sulfidation alteration in arc-related metavolcanic rocks. The area has potential for additional significant pyrophyllite and related aluminosilicate refractory mineral deposits and may have potential for small- to medium-size gold deposits also associated with the high-sulfidation hydrothermal systems. The Carolina slate belt is an elongate zone of mostly low-grade metamorphic rocks of Neoproterozoic to early Paleozoic age that extends from northeastern Georgia to southern Virginia. It is dominated by volcanic rocks but locally consists of fine-grained epiclastic sedimentary rocks. Plutons and subvolcanic bodies have intruded the rocks of the Carolina slate belt in many places and have been important in controlling the metamorphism and in localizing hydrothermal alteration. The Snow Camp-Saxapahaw area is mostly underlain by volcanic and volcaniclastic rocks and lesser amounts of intrusive shallow plutons. The volcanic rocks range in composition from basalt to rhyolite; however andesites, dacites, and rhyodacites are the most abundant. The intrusive bodies are largely granite and quartz monzonite; gabbroic bodies also are common. It was possible to establish the relative ages of only part of these rocks. Two northeast-trending fault zones and fractures divide the map area into three structural blocks; the central block was tilted down to the southwest to form a grabenlike structure. Most of the hydrothermally altered rocks and all of the intensely altered zones are confined to the downdropped block, which we think may have been calderalike in origin. A major volcanic unit, the Reedy Branch Tuff, is limited to the southwestern part of the graben and may be the youngest volcanic rock in the area. Layered rocks record one or more strong folding events, but the diversity of rock types, lack of recognizable stratigraphic markers, and

Boron isotopic composition of tertiary borate deposits in the Puna Plateau of the Central Andes, NW Argentina

International Nuclear Information System (INIS)

Kasemann, Simone; Franz, Gerhard; Viramonte, Jose G.; Alonso, Ricardo N.

1998-01-01

Full text: The most important borate deposits in South America are concentrated in the Central Andes. The Neogene deposits are located in the Puna Plateau of N W Argentina. These continental deposits are stratiform in the tectonically deformed Tertiary rocks. The largest borate accumulations Tincalayu, Sijes and Loma Blanca are part of the Late Miocene Sijes Formation, composed by different evaporitic and clastic units. In the main borate units of each location different phases of borates dominate. In Tincalayu the mayor mineral is borax with minor amounts of kernite and other rare borate minerals (ameginite, rivadavite, etc.). The principal minerals in Loma Blanca are borax with minor ulexite and inyoite. In the two main units of Sijes hydroboracite and colemanite are the major minerals; inyoite and ulexite appear subordinately. The deposition of the borates is due to a strong evaporation in playa lakes, which were fed by boron bearing thermal fluids (Alonso and Viramonte 1990). From Loma Blanca we determined δ 11 B values of ulexite (- 6.3 %0), inyoite (-12.7 %0) and terrugite (-16.2 %0); and from Tincalayu the δ 11 B values of borax (-10.5 %0), tincal (-12.2 %0) kernite (-11.7 %0) and inderite (-15.4 %0). The borates of Sijes are hydroboracite (-16.8 %0 to -17.2 %0), ulexite (-22.4 %0) and inyoite (-28.5 %0 to -29.6 %0). In order to get information about the δ 11 B values and pH of a boron solution we analysed the thermal spring of Antuco. It has a δ 11 B of -12.5%0 at a pH of 7.9. The presently forming ulexite deposit has a δ 11 B of -22.4%0. Borates within one depositional unit show a decreasing δ 11 B value sequence from the Na-Borates to the Ca-Borates related to the boron coordination of the minerals (Oi et al. 1989). The difference in the δ 11 B values excludes the precipitation in equilibrium from solutions with constant pH. According to results from previous work on Neogene borates (Turkey, USA) we interpret the borate succession due to

Erosion and deposition by supercritical density flows during channel avulsion and backfilling: Field examples from coarse-grained deepwater channel-levée complexes (Sandino Forearc Basin, southern Central America)

Science.gov (United States)

Lang, Jörg; Brandes, Christian; Winsemann, Jutta

2017-03-01

Erosion and deposition by supercritical density flows can strongly impact the facies distribution and architecture of submarine fans. Field examples from coarse-grained channel-levée complexes from the Sandino Forearc Basin (southern Central America) show that cyclic-step and antidune deposits represent common sedimentary facies of these depositional systems and relate to the different stages of avulsion, bypass, levée construction and channel backfilling. During channel avulsion, large-scale scour-fill complexes (18 to 29 m deep, 18 to 25 m wide, 60 to > 120 m long) were incised by supercritical density flows. The multi-storey infill of the large-scale scour-fill complexes comprises amalgamated massive, normally coarse-tail graded or widely spaced subhorizontally stratified conglomerates and pebbly sandstones, interpreted as deposits of the hydraulic-jump zone of cyclic steps. The large-scale scour-fill complexes can be distinguished from small-scale channel fills based on the preservation of a steep upper margin and a coarse-grained infill comprising mainly amalgamated hydraulic-jump zone deposits. Channel fills include repeated successions deposited by cyclic steps with superimposed antidunes. The deposits of the hydraulic-jump zone of cyclic steps comprise regularly spaced scours (0.2 to 2.6 m deep, 0.8 to 23 m long) infilled by intraclast-rich conglomerates or pebbly sandstones, displaying normal coarse-tail grading or backsets. These deposits are laterally and vertically associated with subhorizontally stratified, low-angle cross-stratified or sinusoidally stratified sandstones and pebbly sandstones, which were deposited by antidunes on the stoss side of the cyclic steps during flow re-acceleration. The field examples indicate that so-called spaced stratified deposits may commonly represent antidune deposits with varying stratification styles controlled by the aggradation rate, grain-size distribution and amalgamation. The deposits of small-scale cyclic

Platinum-Group Minerals and Other Accessory Phases in Chromite Deposits of the Alapaevsk Ophiolite, Central Urals, Russia

Directory of Open Access Journals (Sweden)

Federica Zaccarini

2016-10-01

Full Text Available An electron microprobe study has been carried out on platinum-group minerals, accessory phases, and chromite in several chromite deposits of the Alapaevsk ophiolite (Central Urals, Russia namely the Bakanov Kluch, Kurmanovskoe, Lesnoe, 3-d Podyony Rudnik, Bol’shaya Kruglyshka, and Krest deposits. These deposits occur in partially to totally serpentinized peridotites. The microprobe data shows that the chromite composition varies from Cr-rich to Al-rich. Tiny platinum-group minerals (PGM, 1–10 µm in size, have been found in the chromitites. The most abundant PGM is laurite, accompanied by minor cuproiridsite and alloys in the system Os–Ir–Ru. A small grain (about 20 μm was found in the interstitial serpentine of the Bakanov Kluch chromitite, and its calculated stoichiometry corresponds to (Ni,Fe5P. Olivine, occurring in the silicate matrix or included in fresh chromite, has a mantle-compatible composition in terms of major and minor elements. Several inclusions of amphibole, Na-rich phlogopite, and clinopyroxene have been identified. The bimodal Cr–Al composition of chromite probably corresponds to a vertical distribution in the ophiolite sequence, implying formation of Cr-rich chromitites in the deep mantle, and Al-rich chromitites close to the Moho-transition zone, in a supra-subduction setting. The presence of abundant hydrous silicate inclusions, such as amphibole and phlogopite, suggests that the Alapaevsk chromitites crystallized as a result of the interaction between a melt enriched in fluids and peridotites. Laurite and cuproiridsite are considered to be magmatic in origin, i.e., entrapped as solid phases during the crystallization of chromite at high temperatures. The sulfur fugacity was relatively high to allow the precipitation of Ir-bearing sulfides, but below the Os–OsS2 buffer. The alloys in the system Os–Ir–Ru are classified as secondary PGM, i.e., formed at low temperature during the serpentinization process. The

Geochemistry and fluid characteristics of the Dalli porphyry Cu-Au deposit, Central Iran

Science.gov (United States)

Zarasvandi, Alireza; Rezaei, Mohsen; Raith, Johann; Lentz, David; Azimzadeh, Amir-Mortaza; Pourkaseb, Hooshang

2015-11-01

The Miocene Dalli porphyry Cu-Au deposit in the central part of Urumieh-Dokhtar magmatic arc is the first reported Au-rich porphyry Cu deposit in the Zagros orogenic belt. The Cu-Au mineralization is mainly hosted in diorite and quartz diorite intrusions, presenting as numerous veinlets in the altered wall rocks, with potassic, phyllic, and propylitic alteration developed. Based on the mineral assemblages and crosscutting relations of veinlets, hydrothermal mineralization-alteration occurred in at least three stages, characterized by veinlets of (1) Qtz + Kfs + Mag ± Ccp, (2) Qtz + Py + Ccp ± Bn ± Cv ± Cc and, (3) Qtz + Chl + Bt. The ore-bearing intrusions exhibit typical geochemical characteristics of subduction zone magmas, including LREE fractionated pattern, strong enrichment in LILE (Cs, Rb, Ba, Pb, and U), and depletion of HFSE, with marked negative Ti and Nb anomalies. The adakite-like ore-hosting porphyry intrusions are characterized by a systematic gradual decreasing and increasing of Y and Eu/Eu∗ with increasing SiO2 content, respectively. Moreover, they exhibit a significant increasing trend of Sr/Y with decreasing of Y, which indicates progressive hornblende fractionation and suppression of plagioclase fractionation during the evolution toward high water content of parental magma. A relatively flat HREE pattern with low Dyn/Ybn and Nb/Ta values may represent that amphibole played a more important role than garnet in the generation of the adakitic melts in the thickened lower crust. Based on the phase assemblages confirmed by detailed laser Raman spectroscopy analyses and proportion of solid, liquid, and gaseous components, five types of fluid inclusions were recognized, which are categorized as; (1) liquid-rich two phase (liquidH2O + vaporH2O) (IIA), (2) vapor-rich two phase (vaporH2O/CO2 + liquidH2O) (IIB), (3) high saline simple fluids (IIIA; liquidH2O + vaporH2O + Hl), (4) high saline opaque mineral-bearing fluids (IIIB; liquidH2O + vaporH2O

Late Cretaceous coal overlying karstic bauxite deposits in the Parnassus-Ghiona Unit, Central Greece: Coal characteristics and depositional environment

Energy Technology Data Exchange (ETDEWEB)

Kalaitzidis, Stavros; Siavalas, George; Christanis, Kimon [Dept. of Geology, University of Patras, 26504 Rio-Patras (Greece); Skarpelis, Nikos [Dept. of Geology and Geoenvironment, University of Athens, 15784 Zografou (Greece); Araujo, Carla Viviane [Petrobras-Cenpes GEOQ/PDEXP, Rua Horacio Macedo n 950, Cidade Universitaria - Ilha do Fundao, 21941-915 Rio de Janeiro (Brazil)

2010-04-01

The Pera-Lakkos coal located on top of bauxite deposits in the Ghiona mining district (Central Greece), is the only known Mesozoic (Late Cretaceous) coal in the country. It was derived from herbaceous plants and algae growing in mildly brackish mires that formed behind a barrier system during a regression of the sea, on a karstified limestone partly filled in with bauxitic detritus. Petrological, mineralogical and geochemical data point to the predominance of reducing conditions and intense organic matter degradation in the palaeomires. O/C vs. H/C and OI vs. HI plots, based on elemental analysis and Rock-Eval data, characterize kerogen types I/II. This reflects the relatively high liptinite content of the coal. Besides kerogen composition, O/C vs. H/C plot for the Pera-Lakkos coals is in accordance with a catagenesis stage of maturation in contrast with vitrinite reflectance and T{sub max} from Rock-Eval pyrolysis, which indicate the onset of oil window maturation stage. Suppression of vitrinite reflectance should be considered and the high liptinite content corroborates this hypothesis. Despite some favourable aspects for petroleum generation presented by the Pera-Lakkos coal, its maximum thickness (up to 50 cm) points to a restricted potential for petroleum generation. Coal oxidation took place either during the late stage of peat formation, due to wave action accompanying the subsequent marine transgression, or epigenetically after the emergence of the whole sequence due to percolation of drainage waters. Both options are also supported by the REE shale-normalized profiles, which demonstrate an upwards depletion in the coal layer. Oxidation also affected pyrite included in the coal; this led to the formation of acidic (sulfate-rich) solutions, which percolated downwards resulting in bleaching of the upper part of the underlying bauxite. (author)

Geologic map of the Alamosa 30’ × 60’ quadrangle, south-central Colorado

Science.gov (United States)

Thompson, Ren A.; Shroba, Ralph R.; Michael N. Machette,; Fridrich, Christopher J.; Brandt, Theodore R.; Cosca, Michael A.

2015-10-15

The Alamosa 30'× 60' quadrangle is located in the central San Luis Basin of southern Colorado and is bisected by the Rio Grande. The Rio Grande has headwaters in the San Juan Mountains of Colorado and ultimately discharges into the Gulf of Mexico 3,000 kilometers (km) downstream. Alluvial floodplains and associated deposits of the Rio Grande and east-draining tributaries, La Jara Creek and Conejos River, occupy the north-central and northwestern part of the map area. Alluvial deposits of west-draining Rio Grande tributaries, Culebra and Costilla Creeks, bound the Costilla Plain in the south-central part of the map area. The San Luis Hills, a northeast-trending series of flat-topped mesas and hills, dominate the landscape in the central and southwestern part of the map and preserve fault-bound Neogene basin surfaces and deposits. The Precambrian-cored Sangre de Cristo Mountains rise to an elevation of nearly 4,300 meters (m), almost 2,000 m above the valley floor, in the eastern part of the map area. In total, the map area contains deposits that record surficial, tectonic, sedimentary, volcanic, magmatic, and metamorphic processes over the past 1.7 billion years.

Dimensionally similar discharges with central rf heating on the DIII-D tokamak

International Nuclear Information System (INIS)

Petty, C.C.; Luce, T.C.; Pinsker, R.I.

1993-04-01

The scaling of L-mode heat transport with normalized gyroradius is investigated on the DIII-D tokamak using central rf heating. A toroidal field scan of dimensionally similar discharges with central ECH and/or fast wave heating show gyro-Bohm-like scaling both globally and locally. The main difference between these restats and those using NBI heating on DIII-D is that with rf heating the deposition profile is not very sensitive to the plasma density. Therefore central heating can be utilized for both the low-B and high-B discharges, whereas for NBI the power deposition is decidedly off-axis for the high-B discharge (i.e., high density)

Seasonal and long-term change in lead deposition in central Japan: evidence for atmospheric transport from continental Asia

International Nuclear Information System (INIS)

Bellis, David J.; Satake, Kenichi; Inagaki, Michiko; Zeng, Jiye; Oizumi, Tsuyoshi

2005-01-01

Long-range transport of air pollution from continental Asia is currently an important issue concerning the Japanese environment, especially in regions susceptible to acidification due to low buffering capacity, such as Murakami, Niigata prefecture, located on the west coast of central Japan. Evidence for long-range transport was obtained through lead and lead isotopic analysis of 84 archived precipitation filters, showing seasonal changes in lead deposition from May 1999 to May 2002. Lead deposition was highest in winter and spring (November through May) each year and lowest in summer. Computed 72-h back trajectories showed that in winter air masses were predominantly transported from the northwest, passing over northern China and eastern Russia, whilst in summer air masses predominantly originated from the southeast passing over Japan. Lead isotopic analysis showed higher 208 Pb/ 206 Pb during winter, indicating that lead originated from a different source. A plot of 207 Pb/ 206 Pb vs. 208 Pb/ 206 Pb identified a thorogenic component, which is excess 208 Pb compared to a standard lead growth curve, indicative of certain lead ores and coals in continental Asia. The data provided evidence of long-range transport of lead from continental Asia to Japan. Bark pockets included within the trunks of two Japanese cedar trees harvested near Murakami, dating between 1972 and 1982, exhibited lead isotope ratios indicative of Japanese-sourced lead. In contrast, current (2003) bark showed thorogenic ratios, consistent with a relative decline in Japanese-sourced and increase in continental-sourced lead

Central Asian integration as a way of guaranteeing regional security, economic growth, feasibility and prospects

OpenAIRE

Najmitdinov, Ahadhon

2010-01-01

Nowadays, CA countries are facing serious challenges. Their industries are slowly recovering from the disruption of “supplier-producer” ties among former Soviet republics and East European states. The transformation from centrally-planned economies into market oriented ones requires absolute reconsideration of political and economic values. The focus towards industrialization has been implemented. For instance, Uzbekistan is among the very few former USSR countries which have developed motor-...

Eating slowly led to decreases in energy intake within meals in healthy women.

Science.gov (United States)

Andrade, Ana M; Greene, Geoffrey W; Melanson, Kathleen J

2008-07-01

Although reducing eating rate is frequently advocated for control of food intake and thus body weight, empirical evidence is extremely limited and inconsistent. We sought to compare the impact of slow and quick eating rates on development of satiation in healthy women. In a randomized design, 30 healthy women (22.9+/-7.1 years; body mass index [calculated as kg/m(2)] 22.1+/-2.9) were studied on two test visits to compare slow and quick eating rates. Satiation was examined as the main outcome, using the objective measure of energy intake during ad libitum meals. At designated times, subjects also rated perceived hunger, satiety, desire to eat, thirst and meal palatability on visual analogue scales. Slow rates of ingestion led to significant decreases in energy intake (quick: 645.7+/-155.9 kcal; slow: 579.0+/-154.7 kcal; Pmeal completion under the quick condition, satiety was significantly lower than the slow condition (PIndex (quick: 0.1; slow: 0.2; Pmeal completion, pleasantness ratings tended to be higher under the slow condition (P=0.04; but not significant after Bonferroni adjustment). Ad libitum energy intake was lower when the meal was eaten slowly, and satiety was higher at meal completion. Although more study is needed, these data suggest that eating slowly may help to maximize satiation and reduce energy intake within meals.

Slowly biodegradable organic compounds impact the biostability of non-chlorinated drinking water produced from surface water

NARCIS (Netherlands)

Hijnen, W.A.M.; Schurer, R.; Bahlman, J.A.; Ketelaars, H.A.M.; Italiaander, R.; Wal, van der A.; Wielen, van der P.W.J.J.

2018-01-01

It is possible to distribute drinking water without a disinfectant residual when the treated water is biologically stable. The objective of this study was to determine the impact of easily and slowly biodegradable compounds on the biostability of the drinking water at three full-scale production

Orbital radar studies of paleodrainages in the central Namib Desert

Science.gov (United States)

Lancaster, N.; Schaber, G.G.; Teller, J.T.

2000-01-01

Orbital radar images of the central Namib Desert show clearly the extent of relict fluvial deposits associated with former courses of the Tsondab and Kuiseb rivers. South of the Kuiseb River, radar data show the existence of a drainage network developed in calcrete-cemented late Tertiary fluvial deposits. The sand-filled paleovalleys are imaged as radar-dark tones in contrast to the radar-bright interfluves where the calcreted gravels occur. The drainage network developed as a result of local runoff from indurated gravels and channeled surface and subsurface flow to the sites of the many interdune lacustrine deposits found in the area. (C) Elsevier Science Inc., 2000.Orbital radar images of the central Namib Desert show clearly the extent of relict fluvial deposits associated with former courses of the Tsondab and Kuiseb rivers. South of the Kuiseb River, radar data show the existence of a drainage network developed in calcrete-cemented late Tertiary fluvial deposits. The sand-filled paleovalleys are imaged as radar-dark tones in contrast to the radar-bright interfluves where the calcreted gravels occur. The drainage network developed as a result of local runoff from indurated gravels and channeled surface and subsurface flow to the sites of the many interdune lacustrine deposits found in the area.

Different injection techniques in the assessment of central haemodynamics in patients with cirrhosis

DEFF Research Database (Denmark)

Christensen, Tine N; Mortensen, Christian; Henriksen, Jens H

2013-01-01

Objective. Patients with cirrhosis often present with an abnormal distribution of blood volume with a reduced central blood volume (CBV) and central circulation time (CCT). In this group of patients it is important to determine the central haemodynamics as accurately as possible. The purpose...... of the present study was to compare an alternative injection technique by injecting technetium-labelled human serum albumin ((99m)Tc-HSA) from a deposit within the catheter lumen with the conventional injection technique by injecting iodine-labelled human serum albumin ((125)I-HSA) directly from a syringe...... was significantly shorter, and CO and CBV were significantly lower when determined by the alternative catheter deposit injection technique compared to determination by the traditional syringe deposit injection technique. The mean difference (bias) between CCT measured with the two methods was 0.38 s with limits...

Central Paleozoic prehistory of Vilyuyskiy syneclise

Energy Technology Data Exchange (ETDEWEB)

Ul' mesvay, F S

1981-01-01

Based on a study of lithological features of the central Paleozoic deposits of the Ygyattinskiy and Kempendyayskiy Basins, a comparison plan is developed. The main features of the middle Paleozoic history of the region are clarified. Their affiliation to a single structure of the avlakogen type is established. Based on the proximity of rock associations and time for development, a similarity of the studied region and the Pripyatskiy-Donets avlakogen has been established. A conclusion is drawn about the possible productivity of the middle Paleozoic deposits.

Coastal evidence for Holocene subduction-zone earthquakes and tsunamis in central Chile

Science.gov (United States)

Dure, Tina; Cisternas, Marco; Horton, Benjamin; Ely, Lisa; Nelson, Alan R.; Wesson, Robert L.; Pilarczyk, Jessica

2015-01-01

The ∼500-year historical record of seismicity along the central Chile coast (30–34°S) is characterized by a series of ∼M 8.0–8.5 earthquakes followed by low tsunamis (tsunami (>10 m), but the frequency of such large events is unknown. We extend the seismic history of central Chile through a study of a lowland stratigraphic sequence along the metropolitan coast north of Valparaíso (33°S). At this site, higher relative sea level during the mid Holocene created a tidal marsh and the accommodation space necessary for sediment that preserves earthquake and tsunami evidence. Within this 2600-yr-long sequence, we traced six laterally continuous sand beds probably deposited by high tsunamis. Plant remains that underlie the sand beds were radiocarbon dated to 6200, 5600, 5000, 4400, 3800, and 3700 cal yr BP. Sediment properties and diatom assemblages of the sand beds—for example, anomalous marine planktonic diatoms and upward fining of silt-sized diatom valves—point to a marine sediment source and high-energy deposition. Grain-size analysis shows a strong similarity between inferred tsunami deposits and modern coastal sediment. Upward fining sequences characteristic of suspension deposition are present in five of the six sand beds. Despite the lack of significant lithologic changes between the sedimentary units under- and overlying tsunami deposits, we infer that the increase in freshwater siliceous microfossils in overlying units records coseismic uplift concurrent with the deposition of five of the sand beds. During our mid-Holocene window of evidence preservation, the mean recurrence interval of earthquakes and tsunamis is ∼500 years. Our findings imply that the frequency of historical earthquakes in central Chile is not representative of the greatest earthquakes and tsunamis that the central Chilean subduction zone has produced.

Coastal evidence for Holocene subduction-zone earthquakes and tsunamis in central Chile

Science.gov (United States)

Dure, Tina; Cisternas, Marco; Horton, Benjamin; Ely, Lisa; Nelson, Alan R.; Wesson, Robert L.; Pilarczyk, Jessica

2015-01-01

The ∼500-year historical record of seismicity along the central Chile coast (30–34°S) is characterized by a series of ∼M 8.0–8.5 earthquakes followed by low tsunamis (10 m), but the frequency of such large events is unknown. We extend the seismic history of central Chile through a study of a lowland stratigraphic sequence along the metropolitan coast north of Valparaíso (33°S). At this site, higher relative sea level during the mid Holocene created a tidal marsh and the accommodation space necessary for sediment that preserves earthquake and tsunami evidence. Within this 2600-yr-long sequence, we traced six laterally continuous sand beds probably deposited by high tsunamis. Plant remains that underlie the sand beds were radiocarbon dated to 6200, 5600, 5000, 4400, 3800, and 3700 cal yr BP. Sediment properties and diatom assemblages of the sand beds—for example, anomalous marine planktonic diatoms and upward fining of silt-sized diatom valves—point to a marine sediment source and high-energy deposition. Grain-size analysis shows a strong similarity between inferred tsunami deposits and modern coastal sediment. Upward fining sequences characteristic of suspension deposition are present in five of the six sand beds. Despite the lack of significant lithologic changes between the sedimentary units under- and overlying tsunami deposits, we infer that the increase in freshwater siliceous microfossils in overlying units records coseismic uplift concurrent with the deposition of five of the sand beds. During our mid-Holocene window of evidence preservation, the mean recurrence interval of earthquakes and tsunamis is ∼500 years. Our findings imply that the frequency of historical earthquakes in central Chile is not representative of the greatest earthquakes and tsunamis that the central Chilean subduction zone has produced.

Deposition of intranasal glucocorticoids--preliminary study.

Science.gov (United States)

Rapiejko, Piotr; Sosnowski, Tomasz R; Sova, Jarosław; Jurkiewicz, Dariusz

2015-01-01

Intranasal glucocorticoids are the treatment of choice in the therapy of rhinitis. The differences in efficiency of particular medications proven by therapeutic index may result from differences in composition of particular formulations as well as from diverse deposition in nasal cavities. Intranasal formulations of glucocorticoids differ in volume of a single dose in addition to variety in density, viscosity and dispenser nozzle structure. The aim of this report was to analyze the deposition of most often used intranasal glucocorticoids in the nasal cavity and assessment of the usefulness of a nose model from a 3D printer reflecting anatomical features of a concrete patient. Three newest and most often used in Poland intranasal glucocorticoids were chosen to analysis; mometasone furoate (MF), fluticasone propionate (FP) and fluticasone furoate (FF). Droplet size distribution obtained from the tested formulations was determined by use of a laser aerosol spectrometer Spraytec (Malvern Instruments, UK). The model of the nasal cavity was obtained using a 3D printer. The printout was based upon a tridimensional reconstruction of nasal cavity created on the basis of digital processing of computed tomography of paranasal sinuses. The deposition of examined medications was established by a method of visualization combined with image analysis using commercial substance which colored itself intensively under the influence of water being the dominant ingredient of all tested preparations. On the basis of obtained results regions of dominating deposition of droplets of intranasal medication on the wall and septum of the nasal cavity were compared. Droplet size of aerosol of tested intranasal medications typically lies within the range of 25-150 µm. All tested medications deposited mainly on the anterior part of inferior turbinate. FP preparation deposited also on the anterior part of the middle nasal turbinate, marginally embracing a fragment of the central part of this

Territorial dynamics and stable home range formation for central place foragers.

Directory of Open Access Journals (Sweden)

Jonathan R Potts

Full Text Available Uncovering the mechanisms behind territory formation is a fundamental problem in behavioural ecology. The broad nature of the underlying conspecific avoidance processes are well documented across a wide range of taxa. Scent marking in particular is common to a large range of terrestrial mammals and is known to be fundamental for communication. However, despite its importance, exact quantification of the time-scales over which scent cues and messages persist remains elusive. Recent work by the present authors has begun to shed light on this problem by modelling animals as random walkers with scent-mediated interaction processes. Territories emerge as dynamic objects that continually change shape and slowly move without settling to a fixed location. As a consequence, the utilisation distribution of such an animal results in a slowly increasing home range, as shown for urban foxes (Vulpes vulpes. For certain other species, however, home ranges reach a stable state. The present work shows that stable home ranges arise when, in addition to scent-mediated conspecific avoidance, each animal moves as a central place forager. That is, the animal's movement has a random aspect but is also biased towards a fixed location, such as a den or nest site. Dynamic territories emerge but the probability distribution of the territory border locations reaches a steady state, causing stable home ranges to emerge from the territorial dynamics. Approximate analytic expressions for the animal's probability density function are derived. A programme is given for using these expressions to quantify both the strength of the animal's movement bias towards the central place and the time-scale over which scent messages persist. Comparisons are made with previous theoretical work modelling central place foragers with conspecific avoidance. Some insights into the mechanisms behind allometric scaling laws of animal space use are also given.

Lithostratigraphy and depositional environments in the Waterberg-Erongo area, central Namibia, and correlation with the main Karoo Basin, South Africa

Science.gov (United States)

Holzförster, Frank; Stollhofen, Harald; Stanistreet, Ian G.

1999-07-01

The dissected landscape of the Waterberg-Erongo area, central Namibia, exposes Karoo-equivalent strata deposited in basins that occur throughout sub-Saharan Africa. Although many are of economic interest, including coal-bearing strata, their depositional history is not well understood. This study of the Waterberg-Erongo area provides detailed lithostratigraphical data, which suggest sedimentation from the late Early Triassic to the Early Jurassic in a fault-bounded depository. Subsidence and sediment supply were controlled predominantly by the northeast-southwest trending Waterberg-Omaruru Fault Zone, which defines the northwestern margin of the depository. Facies development and thickness distribution of the Karoo strata in the Waterberg-Erongo area, perhaps the most continuous of any of the Karoo basins, indicate a northeastwardly-migrating depocentre alongside that fault, in response to major extensional movements in the early pre-South Atlantic rift zone. Periodic fault movements repeatedly caused basinward progradation of the alluvial facies, which are reflected by stacked fining-upward cycles in the lithological record. On a broader scale, the results of this study suggest that the northward propagation of the rift zone between Southern Africa and South America, was partially accommodated by transfer lineaments. Local depocentres developed along these lineaments, such as those in the Waterberg-Erongo area, with localised enhanced subsidence greater than that revealed in other Namibian onshore exposures, dominated by the rifting itself.

Interest Rate Fluctuation Effect on Commercial Bank's Fixed Fund Deposit in Nigeria

OpenAIRE

Okolo Chimaobi Valentine

2015-01-01

Commercial banks in Nigeria adopted many strategies to attract fresh deposits including the use of high deposit rate. However, pricing of banking services moved in favor of the banks at the expense of customers, resulting in their seeking other investment alternatives rather than saving their money in the bank. Both deposit and lending rates were greatly influenced by the Central Bank of Nigeria (CBN) decision on interest rate. Therefore, commercial bank effort to attract...

Regional distribution regularity of sandstone uranium deposits in Asian continent and prospecting strategy for sandstone uranium deposits in China

International Nuclear Information System (INIS)

Chen Zuyi

2002-01-01

Since the 1980's, after the discovery of numerous sandstone uranium deposits in Middle Asia (Kazakhstan, Uzbekistan) many large sandstone uranium deposits have been found in both Russia and Mongolia. So that Asia has become the most concentrated region of sandstone uranium deposits. The known sandstone uranium deposits occur mostly in a arcual tectonic belt constrained from the north by the Siberian continental block, and the Tarim-North China continental block from the south. This belt is named by Russian geologists as the Central Asian Mobile Belt, and some Chinese geologists call it the 'Mongolian Arc'. A lot of large and super large metallic, non-metallic, gold, polymetallic, porphyry copper and gold, massive sulphide and uranium deposits (of sandstone and volcanic types) with different origin and various types concentrated occur in this belt. The abundant and colourful mineral resources in the region are closely associated with the specific geologic-tectonic evolution of the above belt. It is necessary to strengthen the detailed geologic research and uranium prospecting in the region

Local particle densities and global multiplicities in central heavy ion interactions at 3.7, 14.6, 60 and 200 A GeV

International Nuclear Information System (INIS)

Adamovich, M.I.; Alexandrov, Y.A.; Aggarwal, M.M.

1992-03-01

The energy and centrality dependence of local particle pseudorapidity densities as well as validity of various parametrizations of the distributions are examined. The dispersion, σ, of the rapidity density distribution of produced particles varies slowly with centrality and is 0.80, 0.98, 1.21 and 1.41 for central interactions at 3.7, 14.6, 60 and 200 A GeV incident energy, respectively. σ is found to be independent of the size of the interacting system at fixed energy. A novel way of representing the window dependence of the multiplicity as normalized variance versus inverse average multiplicity is outlined. (au)

Local particle densities and global multiplicities in central heavy ion interactions at 3.7, 14.6, 60 and 200 A GeV

International Nuclear Information System (INIS)

Adamovich, M.I.; Alexandrov, Y.A.; Chernyavsky, M.M.; Gerassimov, S.G.; Larionova, V.G.; Maslennikova, N.V.; Orlova, G.I.; Peresadko, N.G.; Rappoport, V.M.; Salmanova, N.A.; Tretyakova, M.I.; Aggarwal, M.M.; Arora, R.; Bhatia, V.S.; Mittra, I.S.; Andreeva, N.P.; Anson, Z.V.; Bubnov, V.I.; Chasnikov, I.Y.; Eligbaeva, G.Z.; Eremenko, L.E.; Gaitinov, A.S.; Kalyachkina, G.S.; Kanygina, E.K.; Lepetan, V.N.; Shakhova, T.I.; Avetyan, F.A.; Marutyan, N.A.; Sarkisova, L.G.; Sarkisyan, V.R.; Badyal, S.K.; Bhasin, A.; Gupta, V.K.; Kachroo, S.; Kaul, G.L.; Kitroo, S.; Mangotra, L.K.; Rao, N.K.; Basova, E.; Nasrulaeva, H.; Nasyrov, S.H.; Petrov, N.V.; Qarshiev, D.A.; Trofimova, T.P.; Tuleeva, U.; Bhalla, K.B.; Gupta, S.K.; Kumar, V.; Lal, P.; Lokanathan, S.; Mookerjee, S.; Palsania, H.S.; Raniwala, R.; Raniwala, S.; Bogdanaov, V.G.; Plyushchev, V.A.; Solovjeva, Z.I.; Burnett, T.H.; Grote, J.; Lord, J.; Skelding, D.; Wilkes, R.J.; Chernova, L.P.; Gulamov, K.G.; Lukicheva, N.S.; Navotny, V.S.; Saidkhanov, N.; Shpilev, S.N.; Surin, E.L.; Svechnikova, L.N.; Zhochova, S.I.; Ganssauge, E.R.; Rhee, J.T.; Garpman, S.; Jakobsson, B.; Nystrand, J.; Otterlund, I.; Soederstroem, K.; Stenlund, E.; Heckman, H.H.; Cai, X.; Huang, H.; Liu, L.S.; Qian, W.Y.; Wang, H.Q.; Zhou, D.C.; Judek, B.; Just, L.; Tothova, M.; Karabova, M.; Vokal, S.; Krasnov, S.A.; Kulikova, S.; Maksimkina, T.N.; Shabratova, G.S.; Tolstov, K.D.; Luo, S.B.; Qin, Y.M.; Zhang, D.H.; Weng, Z.Q.; Xia, Y.L.; Xu, G.F.; Zheng, P.Y.

1992-01-01

The energy and centrality dependence of local particle pseudorapidity densities as well as validity of various parameterizations of the distributions are examined. The dispersion, σ, of the rapidity density distribution of produced particles varies slowly with centrality and is 0.80, 0.98, 1.21 and 1.41 for central interactions at 3.7, 14.6, 60 and 200 A GeV incident energy, respectively, σ is found to be independent of the size of the interacting system at fixed energy. A novel, way of representing the window dependence of the multiplicity as normalized variance versus inverse average multiplicity is outlined. (orig.)

Response of deposit-feeders to exclusion of epibenthic predators in a Mediterranean intertidal flat

NARCIS (Netherlands)

Como, S.; Rossi, F.; Lardicci, C.

2004-01-01

Deposit-feeders are common components of macrofaunal assemblages in intertidal soft sediments. Predation has been considered to have a central role in affecting their distribution and population dynamics. This study investigates the effect of epibenthic predators on deposit-feeders, inhabiting the

Age and geochemistry of host rocks of the Cobre Panama porphyry Cu-Au deposit, central Panama: Implications for the Paleogene evolution of the Panamanian magmatic arc

Science.gov (United States)

Baker, Michael J.; Hollings, Peter; Thompson, Jennifer A.; Thompson, Jay M.; Burge, Colin

2016-04-01

The Cobre Panama porphyry Cu-Au deposit, located in the Petaquilla district of central Panama, is hosted by a sequence of medium- to high-K calc-alkaline volcanic and sub-volcanic rocks. New crystallisation ages obtained from a granodiorite Petaquilla batholith and associated mineralised diorite to granodiorite porphyry stocks and dikes at Cobre Panama indicate that the batholith was emplaced as a multi-phase intrusion, over a period of 4 million years from 32.20 ± 0.76 Ma to 28.26 ± 0.61 Ma, while the porphyritic rocks were emplaced over a 2 million year period from 28.96 ± 0.62 Ma to 27.48 ± 0.68 Ma. Both the volcanic to sub-volcanic host rocks and intrusive rocks of the Cobre Panama deposit evolved via fractional crystallisation processes, as demonstrated by the major elements (e.g. Al2O3, Fe2O3, TiO2 and MgO) displaying negative trends with increasing SiO2. The Petaquilla intrusive rocks, including the diorite-granodiorite porphyries and granodiorite batholith, are geochemically evolved and appear to have formed from more hydrous magmas than the preceding host volcanic rocks, as evidenced by the presence of hornblende phenocrysts, higher degrees of large-ion lithophile element (LILE) and light rare earth element (LREE) enrichment and heavy rare earth element (HREE) depletion, and higher Sr/Y and La/Yb values. However, the degree of LREE enrichment, HREE depletion and La/Yb values are insufficient for the intrusive rocks to be considered as adakites. Collectively, the volcanic and intrusive rocks have LILE, REE and mobile trace element concentrations similar to enriched Miocene-age Cordilleran arc magmatism found throughout central and western Panama. Both the Petaquilla and Cordilleran arc magmatic suites are geochemically more evolved than the late Cretaceous to Eocene Chagres-Bayano arc magmas from northeastern Panama, as they display higher degrees of LILE and LREE enrichment. The geochemical similarities between the Petaquilla and Cordilleran arc magmas

Long-range transported dissolved organic matter, ions and black carbon deposited on Central Asian snow covered glaciers

Science.gov (United States)

Schmale, Julia; Kang, Shichang; Peltier, Richard

2014-05-01

Ninety percent of the Central Asian population depend on water precipitated in the mountains stored in glaciers and snow cover. Accelerated melting of the snow and ice can be induced by the deposition of airborne impurities such as mineral dust, black carbon and co-emitted species leading to significant reductions of the surface albedo. However, Central Asia is a relatively understudied region and data on the source regions, chemical and microphysical characteristics as well as modelling studies of long-range transported air pollution and dust to the Tien Shan mountains is very scarce. We studied the atmospheric aerosol deposited most likely between summer 2012 and summer 2013on three different glaciers in the Kyrgyz Republic. Samples were taken from four snow pits on the glaciers Abramov (2 pits, 39.59 °N, 71.56 °E, 4390 m elevation, 240 cm deep, and 39.62°N, 71.52 °E, 4275 m elevation, 125 cm deep), Ak-Shiirak (41.80 °N, 78.18 °E, 4325 m elevation, 75 cm deep) and Suek (41.78 °N, 77.75 °E, 4341 m elevation, 200 cm deep). The latter two glaciers are located roughly within 6 and 38 km of an operating gold mine. The snow was analyzed for black carbon, ions, metals and organic carbon. We here focus on the results of inorganic ion measurements and organic carbon speciation based on analysis with an Aerodyne high-resolution time-of-flight aerosol spectrometer (HR-ToF-AMS) and potential pollution sources that can be deduced from the chemical information as well as back trajectories. Average contributions of snow impurities measured by the HR-ToF-AMS were dominated by organic carbon. Relative concentrations of organic carbon, sulfate, nitrate and ammonium in snow were 86 %, 3 %, 9 % and 2 % respectively for Abramov, 92 %, 1 %, 5 % and 1 % for Suek, and 95 %, 1 %, 3 % and 1 % for Ak-Shiirak. Generally, impurities on Suek and Ak-Shiirak were three and five times higher than on Abramov. Mass concentrations of organic carbon were on average 6 times higher in samples

Uranium deposits of Zaire

International Nuclear Information System (INIS)

Kitmut, D.; Malu wa Kalenga

1979-01-01

Since April 1960, following the closing of the Shinkolobwe mine, the Republic of Zaire has ceased to be a producer of uranium. Nevertheless, Gecamines (Generale des carrieres et mines du Zaire), a wholly state-owned company, is continuing its research on uranium occurrences which have been discovered in its concession in the course of aerial radiometric prospecting. The most recent campaign was the one carried out in 1969 and 1972 by Hunting Company. On-the-ground verification of these shows has not yet resulted in the discovery of a workable deposit. There are other sectors cutting across Zaire which might well contain uranium deposits: this is true of the sedimentary phosphates of the region of Lower Zaire as well as of the frontier region between Zaire and the Central African Empire. However, no detailed exploration work has yet been carried out. (author)

Atmospheric dry and wet deposition of sulphur and nitrogen species and assessment of critical loads of acidic deposition exceedance in South Africa

Directory of Open Access Journals (Sweden)

Stuart J. Piketh

2011-03-01

Full Text Available We tested the hypothesis that acidic atmospheric pollution deposition, originating from the South African central industrial area, poses an environmental threat across a larger region within the dispersal footprint. A network of 37 passive monitoring sites to measure SO₂ and NO₂ was operated from August 2005 to September 2007. The area extended over the entire northern and eastern interior of South Africa. Monitoring locations were chosen to avoid direct impacts from local sources such as towns, mines and highways. Dry deposition rates of SO₂ and NO₂ were calculated from the measured concentrations. Concentrations of sulphur and nitrogen species in wet deposition from a previous study were used in conjunction with measured rainfall for the years 2006 and 2007 to estimate the wet deposition over the region. The calculated total (non-organic acidic deposition formed the basis for an assessment of exceedance of critical loads based on sensitivity of the regional soils. Regional soil sensitivity was determined by combining two major soil attributes available in the World Inventory of Soil Emission Potentials (International Soil Reference and Information Centre. Results indicate that certain parts of the central pollution source area on the South African Highveld have the potential for critical load exceedance, while limited areas downwind show lower levels of exceedance. Areas upwind and remote areas up and downwind, including forested areas of the Drakensberg escarpment, do not show any exceedance of the critical loads.

Radiation protection Aspects Using the Thermal Waters from the Felix-1 Mai-Oradea Geothermal Deposit

International Nuclear Information System (INIS)

Jurcut, T.; Cosma, C.; Pop, I.

2001-01-01

Full text: The geothermal 'Felix-1 Mai-Oradea' deposit is situated in the western part of Romania and it is well known long years ago. The waters of this deposit are used in the medical treatments in the two resorts (Felix and 1 Mai) and for heating and swimming pools in Oradea town. The deposit depth (2500-3000 m) determines a high temperature (66-900 deg. C) of these waters also a mineral content of 200-1400 mg/l, the main components being Ca and Mg. First time, during some years, the thermal water was directly used in the central heating radiators from 'Nufarul' residential district. At present a heating switch installation is utilised. The high radium content of these thermal waters comparatively with Italian or Japanese thermal waters suggested us a study of radium deposition on the inner walls of the pipes also in the inner central heating radiators. Analysing these depositions using a high resolution Ge-Li detector, the radium-226 and small quantities of radium-224 and 223 isotopes were registered. Average radium-226 deposition was 1200 Bq/kg. (author)

Slowly progressive fluent aphasia; Clinical features and an imaging study including MRI, SPECT and PET

Energy Technology Data Exchange (ETDEWEB)

Sakurai, Yasuhisa; Momose, Toshimitsu; Watanabe, Toshiaki; Ishikawa, Takashi; Iwata, Makoto (Tokyo Univ. (Japan). Faculty of Medicine); Bando, Mitsuaki

1991-05-01

Three patients with slowly progressive fluent aphasia are reported. One of the patients presented with memory disturbance. They were characterized clinically by having selective deficits in vocabulary, which resulted in impairment of confrontation naming, and auditory comprehension. MRI showed an atrophy not only in the left temporal lobe (including the superior, middle and inferior temporal gyri), hippocampus, parahippocampual gyrus, and fusiform gyrus, but also in the left parietal lobe. I-123 IMP SPECT and F-18 FDG PET were used to determine regional cerebral blood flow and regional cerebral metabolic rate, respectively. In addition to the decreased tracer uptake in the left temporal and/or parietal lobe, a decreased uptake was seen in the bilateral basal ganglia, the inner side of the temporal lobe (including the bilateral hippocampus), the right anterior temporal lobe, and the left thalamus. These findings may deny the previous thought that lesions are localized in slowly progressive fluent aphasia. Furthermore, noticeable difficulty in naming, i.e., patients unable to recognize the right answer, are considered attributable to widespread lesions from the whole left temporal lobe, including the hippocampus, to the right temporal lobe. (N.K.).

Evidence for de-sulfidation to form native electrum in the Fire Creek epithermal gold-silver deposit, north-central Nevada

Science.gov (United States)

Perez, J.; Day, J. M.; Cook, G. W.

2012-12-01

The Fire Creek property is a newly developed and previously unstudied epithermal Au-Ag deposit located in the Northern Shoshone range of north central Nevada. The mineralization occurs within and above en echelon N-NW trending basaltic dykes that are hosted within a co-genetic and bimodal suite of mid-Miocene basalts and andesites formed in association with the Yellowstone hotspot-track. Previous studies of Au-Ag mineralization in the Great Basin have focused primarily on extensively mined and/or low-grade deposits. Therefore, the ability for unrestricted sampling of a major Au-Ag deposit early in its exploration and development represents an opportunity for refined understanding of epithermal ore genesis processes. New petrology reveals at least two distinct pulses of mineralization that in relative order of timing are: 1) S-rich veins which are associated with initial host-rock alteration; 2) quartz- and/or calcite-rich veins which vary from fine-grained to lath-like quartz crystals with large calcite crystals in vein centers. Native electrum occurs only within the second phase of mineralization and typically occurs within quartz and adjacent to cross-cut first-phase S-rich veins. In places the electrum appears to replace or form overgrowths around existing sulfide phases. High levels of gold and silver are found in both the first (0.8 g Au/tonne) and second-phase pulses (37 g Au/tonne). Fire Creek shares many similarities with its northern neighbor, the Mule Canyon Au-Ag deposit, with high Fe sulfide contents for some of the ores, altered wall-rocks and the presence of narrow and discontinuous gold-bearing siliceous veins. Like Fire Creek, Mule Canyon possesses two distinct mineralizing phases, a sulfide rich and a late stage calcite/silica assemblage. The first pulse appears to be identical in both locations with a variation of disseminated to euhedral iron-sulfides and associated intense alteration of host rock. However, Fire Creek differs from Mule Canyon in

Pitchblende deposits at the Wood and Calhoun mines, Central City mining district, Gilpin County, Colorado

Science.gov (United States)

Moore, Frank R.; Butler, C.R.

1952-01-01

Pitchblende has been mined in commercial quantities from four gold- and silver-bearing pyrite-sphalerite-galena veins that occur in an area about one-half mile square on the south side of Quartz Hill, Central City district, Gilpin County, Colo. These veins are the Kirk, the German-Belcher, the Wood, and the Calhoun. Two of these veins, the Wood and the Calhoun, were studied in an attempt to determine the geologic factors favorable for pitchblende deposition. All accessible workings at the Wood and East Calhoun mines were mapped by tape and compass, and the distribution of radioactivity was studied in the field. Channel and chip samples were taken for chemical assay to compare radioactivity with uranium content. The pitchblende-bearing veins cat both pre-Cambrian granite gneiss and quartz-biotite schist; however, the gneiss was the more favorable host rock. Two bostonite porphyry dikes of Tertiary(?) age were crosscut by the Wood and Calhoun veins. The pitchblende occurs in lenses erratically distributed along the veins and in stringers extending outward from the veins. In the lenses it forms hard'. masses, but elsewhere it is Soft and powdery. The pitchblende is contemporaneous with the pyrite bat earlier than the sphalerite and galena in the same vein. All the observed pitchblende was at depths of less than 400 ft. The veins probably cannot be mined profitably for the pitchblende alone under present conditions.

An Efficient Hierarchical Multiscale Finite Element Method for Stokes Equations in Slowly Varying Media

KAUST Repository

Brown, Donald L.

2013-01-01

Direct numerical simulation (DNS) of fluid flow in porous media with many scales is often not feasible, and an effective or homogenized description is more desirable. To construct the homogenized equations, effective properties must be computed. Computation of effective properties for nonperiodic microstructures can be prohibitively expensive, as many local cell problems must be solved for different macroscopic points. In addition, the local problems may also be computationally expensive. When the microstructure varies slowly, we develop an efficient numerical method for two scales that achieves essentially the same accuracy as that for the full resolution solve of every local cell problem. In this method, we build a dense hierarchy of macroscopic grid points and a corresponding nested sequence of approximation spaces. Essentially, solutions computed in high accuracy approximation spaces at select points in the the hierarchy are used as corrections for the error of the lower accuracy approximation spaces at nearby macroscopic points. We give a brief overview of slowly varying media and formal Stokes homogenization in such domains. We present a general outline of the algorithm and list reasonable and easily verifiable assumptions on the PDEs, geometry, and approximation spaces. With these assumptions, we achieve the same accuracy as the full solve. To demonstrate the elements of the proof of the error estimate, we use a hierarchy of macro-grid points in [0, 1]2 and finite element (FE) approximation spaces in [0, 1]2. We apply this algorithm to Stokes equations in a slowly porous medium where the microstructure is obtained from a reference periodic domain by a known smooth map. Using the arbitrary Lagrange-Eulerian (ALE) formulation of the Stokes equations (cf. [G. P. Galdi and R. Rannacher, Fundamental Trends in Fluid-Structure Interaction, Contemporary Challenges in Mathematical Fluid Dynamics and Its Applications 1, World Scientific, Singapore, 2010]), we obtain

On homogenization of stokes flow in slowly varying media with applications to fluid–structure interaction

KAUST Repository

Brown, Donald L.

2011-09-11

In this paper we establish corrector estimates for Stokes flow in slowly varying perforated media via two scale asymptotic analysis. Current methods and techniques are often not able to deal with changing geometries prevalent in applied problems. For example, in a deformable porous medium environment, the geometry does not remain periodic under mechanical deformation and if slow variation in the geometry occurs. For such problems, one cannot use classical homogenization results directly and new homogenization results and estimates are needed. Our work uses asymptotic techniques of Marusic-Paloka and Mikelic (Bollettino U. M. I 7:661-671, 1996) where the authors constructed a downscaled velocity which converges to the fine-scale velocity at a rate of ε1/6 where ε is the characteristic length scale. We assume a slowly varying porous medium and study homogenization and corrector estimates for the Stokes equations. Slowly varying media arise, e. g., in fluid-structure interaction (FSI) problems (Popov et al. in Iterative upscaling of flows in deformable porous media, 2008), carbonation of porous concrete (Peter in C. R. Mecanique 335:357-362, 2007a; C. R. Mecanique 335:679-684, 2007b), and various other multiphysics processes. To homogenize Stokes flows in such media we restate the cell problems of Marusic-Paloka and Mikelic (Bollettino U. M. I 7:661-671, 1996) in a moving RVE framework. Further, to recover the same convergence properties it is necessary to solve an additional cell problem and add one more corrector term to the downscaled velocity. We further extend the framework of Marusic-Paloka and Mikelic (Bollettino U. M. I 7:661-671, 1996) to three spatial dimensions in both periodic and variable pore-space cases. Next, we also propose an efficient algorithm for computing the correctors by solving a limited number of cell problems at selected spatial locations. We present two computational examples: one for a constructed medium of elliptical perforations, and

Fabrication of Hyperbolic Metamaterials using Atomic Layer Deposition

DEFF Research Database (Denmark)

Shkondin, Evgeniy

 technology allowing thickness control on atomic scale. As the deposition relies on a surface reaction, conformal pinhole free films can be deposited on various substrates with advanced topology. This method has been a central theme of the project and a core fabrication technique of plasmonic and dielectric...... in dielectric host, the fabrication is still challenging, since ultrathin, continuous, pinhole free nanometer-scale coatings are desired. The required high-quality thin layers have been fabricated using atomic layer deposition (ALD). It is a relatively new, cyclic, self-limiting thin film deposition......, especially in the infrared range, result in high loss and weak connement to the surface. Additionally, the most implemented metals in plasmonics such as Au and Ag are diffcult to pattern at nanoscale due to their limited chemistry, adhesion or oxidation issues. Therefore the implementation of...

In situ fossil seedlings of a Metasequoia-like taxodiaceous conifer from Paleocene river floodplain deposits of central Alberta, Canada.

Science.gov (United States)

Falder, A B; Stockey, R A; Rothwell, G W

1999-06-01

Fossil seeds and seedlings of a Metasequoia-like taxodiaceous conifer occur in Paleocene deposits at the Munce's Hill and Gao Mine localities of central Alberta, Canada. Compression/impression specimens are preserved in upright growth positions among seedlings of the cercidiphyllaceous dicot Joffrea speirsii Crane & Stockey. There are a large number of seeds, a few of which were buried while germinating and show a radicle or short primary root. More than 500 Metasequoia-like seedlings have been identified that have two linear cotyledons with parallel margins and rounded tips. Three specimens have been found that display three cotyledons. Slightly older seedlings show decussate pairs of leaves attached to the stem distal to the cotyledons. Still older seedlings have axillary branches that show varying sizes and numbers of opposite leaves arranged in a single plane distal to the opposite pairs. These specimens reveal that both Joffrea and this extinct taxodiaceous conifer were early colonizers of North American floodplain communities at the beginning of the Tertiary.

Fog deposition fluxes of water and ions to a mountainous site in Central Europe

OpenAIRE

Klemm, Otto; Wrzesinsky, Thomas

2011-01-01

Fog and precipitation composition and deposition were measured over a 1-yr period. Ion concentrations were higher in fog than in precipitation by factors of between 6 and 18. The causes of these differences were less dilution of fog water due to non-availability of condensable water vapour, and more efficient transfer of surface emissions to fog water as compared to rain water or snow. Fogwater and dissolved ions depositions were measured with eddy covariance in combination with a bulk fogwat...

Unusual Slowly Rotating Brown Dwarfs Discovered through Precision Spitzer Photometry

Science.gov (United States)

Heinze, Aren; Metchev, S.

2014-01-01

Many brown dwarfs exhibit low-amplitude rotationally modulated variability due to photospheric inhomogeneities caused by condensate clouds in their atmospheres. The Spitzer Space Telescope 'Weather on Other Worlds' (WoW) project has monitored 44 brown dwarfs at unprecedented photometric precision from space. We present one of several important new results from WoW: the discovery of brown dwarfs with unexpectedly slow rotation periods. While most brown dwarfs have periods of 2-12 hours, we have identified two with well-constrained periods of 13±1 and >20 hours, respectively, and 2 others that show more tentative evidence of longer than 20-hour periods. By serving as almost non-rotating standards, these objects will allow more accurate calibration of spectroscopic measurements of brown dwarfs' projected rotational velocities. The existence of such slowly-rotating objects also constrains models of brown dwarf formation and angular momentum evolution.

The neuropsychological and neuroradiological correlates of slowly progressive visual agnosia.

Science.gov (United States)

Giovagnoli, Anna Rita; Aresi, Anna; Reati, Fabiola; Riva, Alice; Gobbo, Clara; Bizzi, Alberto

2009-04-01

The case of a 64-year-old woman affected by slowly progressive visual agnosia is reported aiming to describe specific cognitive-brain relationships. Longitudinal clinical and neuropsychological assessment, combined with magnetic resonance imaging (MRI), spectroscopy, and positron emission tomography (PET) were used. Sequential neuropsychological evaluations performed during a period of 9 years since disease onset showed the appearance of apperceptive and associative visual agnosia, alexia without agraphia, agraphia, finger agnosia, and prosopoagnosia, but excluded dementia. MRI showed moderate diffuse cortical atrophy, with predominant atrophy in the left posterior cortical areas (temporal, parietal, and lateral occipital cortical gyri). 18FDG-PET showed marked bilateral posterior cortical hypometabolism; proton magnetic resonance spectroscopic imaging disclosed severe focal N-acetyl-aspartate depletion in the left temporoparietal and lateral occipital cortical areas. In conclusion, selective metabolic alterations and neuronal loss in the left temporoparietooccipital cortex may determine progressive visual agnosia in the absence of dementia.

Theoretical investigation into the feasibility to deposit RF energy centrally in the head-and-neck region

International Nuclear Information System (INIS)

Paulides, Margarethus M.; Vossen, Stefan H.J.A.; Zwamborn, Adrianus P.M.; Rhoon, Gerard C. van

2005-01-01

Purpose: To investigate the ability to deposit radiofrequency energy centrally in the neck as a function of antenna positions, number of antennas, and operating frequency. Methods and Materials: Power absorption (PA) distributions in a realistic model of the head-and-neck anatomy are calculated in which the head model is irradiated by an array of dipole antennas. The relative PA distributions corresponding to different setups are visualized and analyzed using the ratio of the average PA (aPA) in the target and neck region. Results: Both the PA distributions and aPA ratios indicate an optimal focusing ability of the setups (i.e., the ability to direct energy efficiently into the target region), between 400 and 600 MHz. In this frequency band, the focusing ability depends only moderately on the size of the neck. Finally, it is found that the focusing ability at 433 MHz is increased significantly by increasing the number of antenna elements. Conclusions: The optimal frequency is found to be highly dependent on the size of the target volume; thus, a single optimum is hard to define. However, future clinical research will focus on 433 MHz based on the optimal range of frequencies, as found in this study

Morphogenesis of the Czechowskie Lake as inferred from the sedimentological analysis of limnic, colluvial and glacifluvial deposits (Eastern Pomerania, North Central Poland)

Science.gov (United States)

Kordowski, Jaroslaw; Błaszkiewicz, Mirosław; Kramkowski, Mateusz; Słowiński, Michał; Tyszkowski, Sebastian; Brauer, Achim; Ott, Florian

2014-05-01

Czechowskie Lake is situated in north-central Poland in Tuchola Forest, about 100 kilometers SW away from Gdańsk. In the deepest parts of the lake bottom, there are hidden laminated sediments which hold the Late Glacial and Holcene climatic record. These deposits are subject of detailled work of the joint German-Polish Virtual Institute of Integrated Climate and Landscape Evolution (ICLEA) of the Helmholtz Association. It has the area of 76,6 ha. Actual water level is at 109,9 m a.s.l. The average depth is 9,59 m, maximal 32 m. The lake occupies a large subglacial channel, reproduced within the glacifluvial sediments of the Pomeranian Phase of the last glaciation. In the widest place it has the width of 1 kilometer. The maximal depth of the channel (counting from the channel edges to the reconstructed deepest lake mineral floor (after removal of the limnic sediments)) may reach 70 meters. Inside of the channel some throughs and small hills do exist which are built of outwash sediments but, considering internal structures, they bear some similarity to the dead ice moraines and kames. The vicinity of the channel consists of two outwash plain levels. The lower one was created on the dead ice blocks. The maximum infilling with the limnic and telmatic sediments reaches over 12 m. In the bottom of the lake there is a marked presence of many overdeepenings with the diameter of dozen or several dozen meters and the depth of up to 10 m with numerous, distinct throughs between them. They favoured the preservation of the lamination in the deepest parts of the lake due to waves hampering and stopping of the density circulation in the lake waterbody. In the colluvial and fluvioglacial deposits there were carried out carefull sedminetological analyses. Limnic sediments were identified by bore holes with preserved undisturbed structure. All done works revealed that some of the glacifluvial deposits were deposited in subglacial conditions in supercritical flow regime. They were

Multiple Stage Ore Formation in the Chadormalu Iron Deposit, Bafq Metallogenic Province, Central Iran: Evidence from BSE Imaging and Apatite EPMA and LA-ICP-MS U-Pb Geochronology

Directory of Open Access Journals (Sweden)

Hassan Heidarian

2018-02-01

Full Text Available The Chadormalu magnetite-apatite deposit in Bafq metallogenic province, Central Iran, is hosted in the late Precambrian-lower Cambrian volcano-sedimentary rocks with sodic, calcic, and potassic alterations characteristic of iron oxide copper-gold (IOCG and iron oxide-apatite (IOA ore systems. Apatite occurs as scattered irregular veinlets and disseminated grains, respectively, within and in the marginal parts of the main ore-body, as well as apatite-magnetite veins in altered wall rocks. Textural evidence (SEM-BSE images of these apatites shows primary bright, and secondary dark areas with inclusions of monazite/xenotime. The primary, monazite-free fluorapatite contains higher concentrations of Na, Si, S, and light rare earth elements (LREE. The apatite was altered by hydrothermal events that led to leaching of Na, Si, and REE + Y, and development of the dark apatite. The bright apatite yielded two U-Pb age populations, an older dominant age of 490 ± 21 Ma, similar to other iron deposits in the Bafq district and associated intrusions, and a younger age of 246 ± 17 Ma. The dark apatite yielded a U-Pb age of 437 ± 12 Ma. Our data suggest that hydrothermal magmatic fluids contributed to formation of the primary fluorapatite, and sodic and calcic alterations. The primary apatite reequilibrated with basinal brines in at least two regional extensions and basin developments in Silurian and Triassic in Central Iran.

Deposition of metal Islands, metal clusters and metal containing single molecules on self-assembled monolayers

NARCIS (Netherlands)

Speets, Emiel Adrianus

2005-01-01

The central topic of this thesis is the deposition of metals on Self-Assembled Monolayers (SAMs). Metals are deposited in the form of submicron scale islands, nanometer scale clusters, and as supramolecular, organometallic coordination cages. Several SAMs on various substrates were prepared and

Pinning, de-pinning and re-pinning of a slowly varying rivulet

KAUST Repository

Paterson, C.; Wilson, S.K.; Duffy, B.R.

2013-01-01

The solutions for the unidirectional flow of a thin rivulet with prescribed volume flux down an inclined planar substrate are used to describe the locally unidirectional flow of a rivulet with constant width (i.e. pinned contact lines) but slowly varying contact angle as well as the possible pinning and subsequent de-pinning of a rivulet with constant contact angle and the possible de-pinning and subsequent re-pinning of a rivulet with constant width as they flow in the azimuthal direction from the top to the bottom of a large horizontal cylinder. Despite being the same locally, the global behaviour of a rivulet with constant width can be very different from that of a rivulet with constant contact angle. In particular, while a rivulet with constant non-zero contact angle can always run from the top to the bottom of the cylinder, the behaviour of a rivulet with constant width depends on the value of the width. Specifically, while a narrow rivulet can run all the way from the top to the bottom of the cylinder, a wide rivulet can run from the top of the cylinder only to a critical azimuthal angle. The scenario in which the hitherto pinned contact lines of the rivulet de-pin at the critical azimuthal angle and the rivulet runs from the critical azimuthal angle to the bottom of the cylinder with zero contact angle but slowly varying width is discussed. The pinning and de-pinning of a rivulet with constant contact angle, and the corresponding situation involving the de-pinning and re-pinning of a rivulet with constant width at a non-zero contact angle which generalises the de-pinning at zero contact angle discussed earlier, are described. In the latter situation, the mass of fluid on the cylinder is found to be a monotonically increasing function of the constant width. © 2013 Elsevier Masson SAS. All rights reserved.

Pinning, de-pinning and re-pinning of a slowly varying rivulet

KAUST Repository

Paterson, C.

2013-09-01

The solutions for the unidirectional flow of a thin rivulet with prescribed volume flux down an inclined planar substrate are used to describe the locally unidirectional flow of a rivulet with constant width (i.e. pinned contact lines) but slowly varying contact angle as well as the possible pinning and subsequent de-pinning of a rivulet with constant contact angle and the possible de-pinning and subsequent re-pinning of a rivulet with constant width as they flow in the azimuthal direction from the top to the bottom of a large horizontal cylinder. Despite being the same locally, the global behaviour of a rivulet with constant width can be very different from that of a rivulet with constant contact angle. In particular, while a rivulet with constant non-zero contact angle can always run from the top to the bottom of the cylinder, the behaviour of a rivulet with constant width depends on the value of the width. Specifically, while a narrow rivulet can run all the way from the top to the bottom of the cylinder, a wide rivulet can run from the top of the cylinder only to a critical azimuthal angle. The scenario in which the hitherto pinned contact lines of the rivulet de-pin at the critical azimuthal angle and the rivulet runs from the critical azimuthal angle to the bottom of the cylinder with zero contact angle but slowly varying width is discussed. The pinning and de-pinning of a rivulet with constant contact angle, and the corresponding situation involving the de-pinning and re-pinning of a rivulet with constant width at a non-zero contact angle which generalises the de-pinning at zero contact angle discussed earlier, are described. In the latter situation, the mass of fluid on the cylinder is found to be a monotonically increasing function of the constant width. © 2013 Elsevier Masson SAS. All rights reserved.

Hideout of sea water impurities in steam generator tube deposits: laboratory and field studies

International Nuclear Information System (INIS)

Balakrishnan, P.V.; Turner, C.W.; Thompson, R.; Sawochka, S.

1996-01-01

Sea water impurities hide out within thin (∼10 μm) deposits on steam generator tubes, as demonstrated by both laboratory studies using segments of fouled steam generator tubes pulled in 1992 from Crystal River-3 nuclear power station and field hideout return studies performed during recent plant shutdowns. Laboratory tests performed at 279 o C (534 o F) and heat fluxes ranging from 35 to 114 kW/m 2 (11,100 - 36,150 Btu/h.ft 2 ), conditions typical of the lower tubesheet to the first support plate region of a once-through steam generator, showed that impurity hideout can occur in thin free-span tube deposits. The extent of hideout increased with increasing heat flux. Soluble species, such as sodium and chloride ions, returned promptly to the bulk water from the deposits when the heat flux was turned off, whereas less soluble species, such as calcium sulfate and magnesium hydroxide, returned more slowly. Recent field hideout return studies performed at Crystal River-3 where the water level in the steam generators was maintained below the first tube support plate during the shutdown, thus wetting only the thin deposits in the free span and the small sludge pile, corroborate the laboratory findings, showing that hideout does indeed occur in the free-span regions of the tubes. These findings suggest that hideout within tube deposits has to be accounted for in the calculation of crevice chemistry from hideout return studies and in controlling the bulk chemistry using the molar ratio criterion. (author). 3 refs., 4 tabs., 3 figs

Forest canopy uptake of atmospheric nitrogen deposition at eastern U.S. conifer sites: Carbon storage implications?

Science.gov (United States)

Herman Sievering; Ivan Fernandez; John Lee; John Hom; Lindsey Rustad

2000-01-01

Dry deposition determinations, along with wet deposition and throughfall (TF) measurements, at a spruce fir forest in central Maine were used to estimate the effect of atmospherically deposited nitrogen (N) uptake on forest carbon storage. Using nitric acid and particulate N as well as TF ammonium and nitrate data, the growing season (May-October) net canopy uptake of...

A Developmental Study of Static Postural Control and Superimposed Arm Movements in Normal and Slowly Developing Children.

Science.gov (United States)

Fisher, Janet M.

Selected electromyographic parameters underlying static postural control in 4, 6, and 8 year old normally and slowly developing children during performance of selected arm movements were studied. Developmental delays in balance control were assessed by the Cashin Test of Motor Development (1974) and/or the Williams Gross Motor Coordination Test…

Sedimentary environments and stratigraphy of the carbonate-silicilastic deposits of the Shirgesht Formation: implications for eustasy and local tectonism in the Kalmard Block, Central Iran

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reza Mousavi-Harami

2015-09-01

Full Text Available   Introduction   Sedimentological and sequence stratigraphic analysis providing insight into the main relationships between sequence architecture and stacking pattern, syn/post-depositional tectonics, and eustatic sea-level fluctuations (Gawthorpe and Leeder 2000 Zecchin et al. 2003, 2004 Carpentier et al. 2007. Relative variations in sea level are due to tectonic activity and eustasy. The Shirgesht Formation in the Kalmard Block of Central Iran provides a useful case study for to determine the processes responsible on internal architecture and stacking pattern of depositional sequences in a half-graben basin. In the Shirgesht Formation, siliciclastic and carbonate successions of the Kalmard Basin, the cyclic stratigraphic record is the result of the complex interaction of regional uplift, eustasy, local tectonics, sediment supply, and sedimentary processes (Bayet-Goll 2009, 2014 Hosseini-Barzi and Bayet-Goll 2009.     Material & Methods   Lower Paleozoic successions in Tabas and Kalmard blocks from Central Iran share the faunal and floral characteristics with other Gondwana sectors such as south-western Europe and north Africa–Middle East (Ghaderi et al. 2009. The geology of these areas was outlined by Ruttner et al. (1968 and by Bruton et al. (2004. The Cambrian-Middle Triassic strata in the Kalmard Block were deposited in a shallow water platform that possesses lithologic dissimilarities with the Tabas area (Aghanabati 2004. The occurrence of two active faults indicates clearly that Kalmard basin formed a mobile zone throughout the Paleozoic so that lithostratigraphic units show considerably contrasting facies in comparison with Tabas basin (Hosseini-Barzi and Bayet-Goll 2009 Bayet-Goll 2014 . The Shirgesht Formation in the Block Kalmard is mainly composed of carbonate-siliciclastic successions that disconformability overlain Kalmard Formation (attributed to Pre-Cambrian and is underlain by Gachal (Carboniferous or

Sedimentary environments and stratigraphy of the carbonate-silicilastic deposits of the Shirgesht Formation: implications for eustasy and local tectonism in the Kalmard Block, Central Iran

Directory of Open Access Journals (Sweden)

aram bayetgoll

2015-10-01

Full Text Available Introduction   Sedimentological and sequence stratigraphic analysis providing insight into the main relationships between sequence architecture and stacking pattern, syn/post-depositional tectonics, and eustatic sea-level fluctuations (Gawthorpe and Leeder 2000; Zecchin et al. 2003, 2004; Carpentier et al. 2007. Relative variations in sea level are due to tectonic activity and eustasy. The Shirgesht Formation in the Kalmard Block of Central Iran provides a useful case study for to determine the processes responsible on internal architecture and stacking pattern of depositional sequences in a half-graben basin. In the Shirgesht Formation, siliciclastic and carbonate successions of the Kalmard Basin, the cyclic stratigraphic record is the result of the complex interaction of regional uplift, eustasy, local tectonics, sediment supply, and sedimentary processes (Bayet-Goll 2009, 2014; Hosseini-Barzi and Bayet-Goll 2009.     Material & Methods   Lower Paleozoic successions in Tabas and Kalmard blocks from Central Iran share the faunal and floral characteristics with other Gondwana sectors such as south-western Europe and north Africa–Middle East (Ghaderi et al. 2009. The geology of these areas was outlined by Ruttner et al. (1968 and by Bruton et al. (2004. The Cambrian-Middle Triassic strata in the Kalmard Block were deposited in a shallow water platform that possesses lithologic dissimilarities with the Tabas area (Aghanabati 2004. The occurrence of two active faults indicates clearly that Kalmard basin formed a mobile zone throughout the Paleozoic so that lithostratigraphic units show considerably contrasting facies in comparison with Tabas basin (Hosseini-Barzi and Bayet-Goll 2009; Bayet-Goll 2014 . The Shirgesht Formation in the Block Kalmard is mainly composed of carbonate-siliciclastic successions that disconformability overlain Kalmard Formation (attributed to Pre-Cambrian and is underlain by Gachal (Carboniferous or Rahdar (Devonian

The Influence of Slowly Varying Mass on Severity of Dynamics Nonlinearity of Bearing-Rotor Systems with Pedestal Looseness

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Mian Jiang

2018-01-01

Full Text Available Nonlinearity measure is proposed to investigate the influence of slowly varying mass on severity of dynamics nonlinearity of bearing-rotor systems with pedestal looseness. A nonlinear mathematical model including the effect of slowly varying disk mass is developed for a bearing-rotor system with pedestal looseness. The varying of equivalent disk mass is described by a cosine function, and the amplitude coefficient is used as a control parameter. Then, nonlinearity measure is employed to quantify the severity of dynamics nonlinearity of bearing-rotor systems. With the increasing of looseness clearances, the curves that denote the trend of nonlinearity degree are plotted for each amplitude coefficient of mass varying. It can be concluded that larger amplitude coefficients of the disk mass varying will have more influence on the severity of dynamics nonlinearity and generation of chaotic behaviors in rotor systems with pedestal looseness.

The impact of acid deposition and forest harvesting on lakes and their forested catchments in south central Ontario: a critical loads approach

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S. A. Watmough

2002-01-01

Full Text Available The impact of acid deposition and tree harvesting on three lakes and their representative sub-catchments in the Muskoka-Haliburton region of south-central Ontario was assessed using a critical loads approach. As nitrogen dynamics in forest soils are complex and poorly understood, for simplicity and to allow comparison among lakes and their catchments, CLs (A for both lakes and forest soils were calculated assuming that nitrate leaching from catchments will not change over time (i.e. a best case scenario. In addition, because soils in the region are shallow, base cation weathering rates for the representative sub-catchments were calculated for the entire soil profile and these estimates were also used to calculate critical loads for the lakes. These results were compared with critical loads obtained by the Steady State Water Chemistry (SSWC model. Using the SSWC model, critical loads for lakes were between 7 and 19 meq m-2yr-1 higher than those obtained from soil measurements. Lakes and forests are much more sensitive to acid deposition if forests are harvested, but two acid-sensitive lakes had much lower critical loads than their respective forested sub-catchments implying that acceptable acid deposition levels should be dictated by the most acid-sensitive lakes in the region. Under conditions that assume harvesting, the CL (A is exceeded at two of the three lakes and five of the six sub-catchments assessed in this study. However, sulphate export from catchments greatly exceeds input in bulk deposition and, to prevent lakes from falling below the critical chemical limit, sulphate inputs to lakes must be reduced by between 37% and 92% if forests are harvested. Similarly, sulphate leaching from forested catchments that are harvested must be reduced by between 16 and 79% to prevent the ANC of water draining the rooting zone from falling below 0 μeq l-1. These calculations assume that extremely low calcium leaching losses (9–27 μeq l-1 from

Geology and mineral deposits of Churchill County, Nevada

Science.gov (United States)

Willden, Ronald; Speed, Robert C.

1974-01-01

Churchill County, in west-central Nevada, is an area of varied topography and geology that has had a rather small total mineral production. The western part of the county is dominated by the broad low valley of the Carson Sink, which is underlain by deposits of Lake Lahontan. The bordering mountain ranges to the west and south are of low relief and underlain largely by Tertiary volcanic and sedimentary units. Pre-Tertiary rocks are extensively exposed east of the Carson Sink in the Stillwater Range, Clan Alpine Mountains, Augusta Mountains, and New Pass Mountains. The eastern valleys are underlain by Quaternary alluvial and lacustrine deposits contemporaneous with the western deposits of Lake Lahontan. The eastern mountain ranges are more rugged than the western ranges and have higher relief; the eastern valleys are generally narrower.

Λ( t ) cosmology induced by a slowly varying Elko field

Energy Technology Data Exchange (ETDEWEB)

Pereira, S.H.; Pinho, A.S.S.; Silva, J.M. Hoff da [Universidade Estadual Paulista (Unesp), Faculdade de Engenharia, Guaratinguetá, Departamento de Física e Química Av. Dr. Ariberto Pereira da Cunha 333, 12516-410—Guaratinguetá, SP (Brazil); Jesus, J.F., E-mail: shpereira@feg.unesp.br, E-mail: alexandre.pinho510@gmail.com, E-mail: hoff@feg.unesp.br, E-mail: jfjesus@itapeva.unesp.br [Universidade Estadual Paulista (Unesp), Campus Experimental de Itapeva, R. Geraldo Alckmin, 519 Itapeva, SP (Brazil)

2017-01-01

In this work the exact Friedmann-Robertson-Walker equations for an Elko spinor field coupled to gravity in an Einstein-Cartan framework are presented. The torsion functions coupling the Elko field spin-connection to gravity can be exactly solved and the FRW equations for the system assume a relatively simple form. In the limit of a slowly varying Elko spinor field there is a relevant contribution to the field equations acting exactly as a time varying cosmological model Λ( t )=Λ{sub *}+3β H {sup 2}, where Λ{sub *} and β are constants. Observational data using distance luminosity from magnitudes of supernovae constraint the parameters Ω {sub m} and β, which leads to a lower limit to the Elko mass. Such model mimics, then, the effects of a dark energy fluid, here sourced by the Elko spinor field. The density perturbations in the linear regime were also studied in the pseudo-Newtonian formalism.

Lung Deposition And Biological Effects Of Inhaled Radon Progenies

International Nuclear Information System (INIS)

Balashazy, I.; Farkas, A.; Szoke, I.; Moustafa, M.; Kudela, G.

2010-01-01

Inhaled radon progenies provide more than the half of natural radiation exposure. There is increasing evidence that the cellular distribution of radiation burden is an important factor regarding the biological response to ionisation radiation, thus, one of our tasks was the characterisation of the distribution of cellular exposure. Histological studies of former uranium miners presented strong correlation between primer deposition hot spots and neoplastic lesions. Most of these lesions were located along the carinal regions of the large bronchial airways. In the present work, computational fluid dynamics (CFD) approaches have been applied to simulate the deposition distribution of inhaled radon progenies along central human airways. The geometry and the cellular structure of epithelial lung tissue were numerically reconstructed based on anatomical and histological data. Single and multiple ha-hit and cellular dose distributions have been computed applying Monte Carlo modelling techniques at different breathing conditions. Figure 1. Deposition enhancement factor (EF) of inhaled radon progenies on a central airway bifurcation in airway generations 4-5 during light physical activity breathing condition. Size of scanning surface element is a 45μm side triangle. Left panel: EF max=1400,Dp=200 nm (attached). Right panel: EF max1290, Dp= 1 nm (unattached). Values of local per average deposition densities, that is, enhancement factors (Figure 1), hit probabilities and doses may be up to two-three orders of magnitude higher in the deposition hot spots than the average values. Dose calculations revealed that some cell clusters may receive high doses even at low exposure conditions. Applying the model to different radiation exposure conditions useful relations can be received regarding the linear-non threshold hypothesis

Optimization of deposition conditions of CdS thin films using response surface methodology

Energy Technology Data Exchange (ETDEWEB)

Yücel, Ersin, E-mail: dr.ersinyucel@gmail.com [Department of Physics, Faculty of Arts and Sciences, Mustafa Kemal University, 31034 Hatay (Turkey); Güler, Nuray [Department of Physics, Faculty of Arts and Sciences, Mustafa Kemal University, 31034 Hatay (Turkey); Yücel, Yasin [Department of Chemistry, Faculty of Arts and Sciences, Mustafa Kemal University, 31034 Hatay (Turkey)

2014-03-15

Highlights: • Statistical methods used for optimization of CdS deposition parameters. • The morphology of the films was smooth, homogeneous and continuous. • Optimal conditions found as pH 11, stirring speed:361 rpm and deposition time: 55 min. • CdS thin film band gap value was 2.72 eV under the optimum conditions. -- Abstract: Cadmium sulfide (CdS) thin films were prepared on glass substrates by chemical bath deposition (CBD) technique under different pH, stirring speed and deposition time. Response Surface Methodology (RSM) and Central Composite Design (CCD) were used to optimization of deposition parameters of the CdS thin films. RSM and CCD were also used to understand the significance and interaction of the factors affecting the film quality. Variables were determined as pH, stirring speed and deposition time. The band gap was chosen as response in the study. Influences of the variables on the band gap and the film quality were investigated. 5-level-3-factor central composite design was employed to evaluate the effects of the deposition conditions parameters such as pH (10.2–11.8), stirring speed (132–468 rpm) and deposition time (33–67 min) on the band gap of the films. The samples were characterized using X-ray diffraction (XRD), scanning electron microscope (SEM) and ultraviolet–visible spectroscopy (UV–vis) measurements. The optimal conditions for the deposition parameters of the CdS thin films have been found to be: pH 11, 361 of stirring speed and 55 min of deposition time. Under the optimal conditions theoretical (predicted) band gap of CdS (2.66 eV) was calculated using optimal coded values from the model and the theoretical value is good agreement with the value (2.72 eV) obtained by verification experiment.

Management of the slowly emerging zoonosis, Hendra virus, by private veterinarians in Queensland, Australia: a qualitative study.

Science.gov (United States)

Mendez, Diana H; Kelly, Jenny; Buttner, Petra; Nowak, Madeleine; Speare, Rick

2014-09-17

Veterinary infection control for the management of Hendra virus (HeV), an emerging zoonosis in Australia, remained suboptimal until 2010 despite 71.4% (5/7) of humans infected with HeV being veterinary personnel or assisting a veterinarian, three of whom died before 2009. The aim of this study was to identify the perceived barriers to veterinary infection control and HeV management in private veterinary practice in Queensland, where the majority of HeV outbreaks have occurred in Australia. Most participants agreed that a number of key factors had contributed to the slow uptake of adequate infection control measures for the management of HeV amongst private veterinarians: a work culture characterised by suboptimal infection control standards and misconceptions about zoonotic risks; a lack of leadership and support from government authorities; the difficulties of managing biosecurity and public health issues from a private workforce perspective; and the slow pattern of emergence of HeV. By 2010, some infection control and HeV management changes had been implemented. Participants interviewed agreed that further improvements remained necessary; but also cautioned that this was a complex process which would require time. Private veterinarians and government authorities prior to 2009 were unprepared to handle new slowly emerging zoonoses, which may explain their mismanagement of HeV. Slowly emerging zoonoses may be of low public health significance but of high significance for specialised groups such as veterinarians. Private veterinarians, who are expected to fulfil an active biosecurity and public health role in the frontline management of such emerging zoonoses, need government agencies to better recognise their contribution, to consult with the veterinary profession when devising guidelines for the management of zoonoses and to provide them with greater leadership and support. We propose that specific infection control guidelines for the management of slowly emerging

Pressure-temperature condition and hydrothermal-magmatic fluid evolution of the Cu-Mo Senj deposit, Central Alborz: fluid inclusion evidence

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Ebrahim Tale Fazel

2017-02-01

The Cu-Mo Senj deposit covering an area about 5 km2 is located in the central part of the Alborz Magmatic Arc (AMA. The Nb/Y versus Zr/TiO2 diagram (after Winchester and Floyd, 1977 illustrates a typical trend for the magmas in the Senj magmatic area–starting from basaltic and evolving to dacite/rhyodacitic compositions, with few data plotting in the alkali basalt field. Most of the igneous rocks plot within the medium- and high-K fields in the K2O versus SiO2 diagram. The igneous rocks from the Senj area define a typical high-K calc-alkaline on SiO2 versus K2O diagram (Le Maitre et al., 1989. All studied rocks show similar incompatible trace element patterns with an enrichment of large ion lithophile elements (LILE: K, Rb, Ba, Th and depletion of high field strength elements (HFSE: Nb and Ti, which are typical features of magmas from convergent margin tectonic settings (Pearce and Can, 1973. At least three veining stages namely QBC, QM, and QP which are related to alteration and mineralization are distinguished at the Senj mineralized area. Three distinct alteration assemblages including K-feldspar-biotite-sericite-quartz, quartz-sericite-K-feldspar-pyrite, and K-feldspar-biotite-sericite-quartz, are distinguishable with these veins. About 80 % of the copper at Senj is associated with the early QBC-stage veins, with another 5 to 15 % in the QM-and QP-stage veins. About 70 % of the molybdenite occur in QM veins. Discussion Fluid inclusion distribution, fluid chemistry, and homogenization behavior document that S2-type fluids are samples of magma-derived aqueous-saline fluids characterized by high salinity and temperature, and high Cu content. Such parental fluids scavenged Cu and Mo from the melt below and transported them to the hydrothermal system above. The increased abundance of S- and LV-types inclusion coinciding with the highest grade Cu mineralization (early QBC-stage veins at the Senj deposit suggests that brine-vapor unmixing and phase separation plays an

Factors influencing temporal changes in chemical composition of biogenic deposits in the middle Tążyna River Valley (Kuyavian Lakeland, central Poland)

Science.gov (United States)

Okupny, Daniel; Rzepecki, Seweryn; Borówka, Ryszard Krzysztof; Forysiak, Jacek; Twardy, Juliusz; Fortuniak, Anna; Tomkowiak, Julita

2016-06-01

The present paper discusses the influence of geochemical properties on biogenic deposits in the Wilkostowo mire near Toruń, central Poland. The analysed core has allowed the documentation of environmental changes between the older part of the Atlantic Period and the present day (probably interrupted at the turn of the Meso- and Neoholocene). In order to reconstruct the main stages in the sedimentation of biogenic deposits, we have used stratigraphic variability of selected litho-geochemical elements (organic matter, calcium carbonate, biogenic and terrigenous silica, macro- and micro-elements: Na, K, Mg, Ca, Fe, Mn, Cu, Zn, Pb, Cr and Ni). The main litho-geochemical component is CaCO3; its content ranges from 4.1 per cent to 92 per cent. The variability of CaCO3 content reflects mainly changes in hydrological and geomorphological conditions within the catchment area. The effects of prehistoric anthropogenic activities in the catchment of the River Tążyna, e.g., the use of saline water for economic purposes, are recorded in a change from calcareous gyttja into detritus-calcareous gyttja sedimentation and an increased content of lithophilous elements (Na, K, Mg and Ni) in the sediments. Principal component analysis (PCA) has enabled the distinction the most important factors that affected the chemical composition of sediments at the Wilkostowo site, i.e., mechanical and chemical denudation processes in the catchment, changes in redox conditions, bioaccumulation of selected elements and human activity. Sediments of the Wilkostowo mire are located in the direct vicinity of an archaeological site, where traces of intensive settlement dating back to the Neolithic have been documented. The settlement phase is recorded both in lithology and geochemical properties of biogenic deposits which fill the reservoir formed at the bottom of the Parchania Canal Valley.

Factors influencing temporal changes in chemical composition of biogenic deposits in the middle Tążyna River Valley (Kuyavian Lakeland, central Poland

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Okupny Daniel

2016-06-01

Full Text Available The present paper discusses the influence of geochemical properties on biogenic deposits in the Wilkostowo mire near Toruń, central Poland. The analysed core has allowed the documentation of environmental changes between the older part of the Atlantic Period and the present day (probably interrupted at the turn of the Meso- and Neoholocene. In order to reconstruct the main stages in the sedimentation of biogenic deposits, we have used stratigraphic variability of selected litho-geochemical elements (organic matter, calcium carbonate, biogenic and terrigenous silica, macro- and micro-elements: Na, K, Mg, Ca, Fe, Mn, Cu, Zn, Pb, Cr and Ni. The main litho-geochemical component is CaCO3; its content ranges from 4.1 per cent to 92 per cent. The variability of CaCO3 content reflects mainly changes in hydrological and geomorphological conditions within the catchment area. The effects of prehistoric anthropogenic activities in the catchment of the River Tążyna, e.g., the use of saline water for economic purposes, are recorded in a change from calcareous gyttja into detritus-calcareous gyttja sedimentation and an increased content of lithophilous elements (Na, K, Mg and Ni in the sediments. Principal component analysis (PCA has enabled the distinction the most important factors that affected the chemical composition of sediments at the Wilkostowo site, i.e., mechanical and chemical denudation processes in the catchment, changes in redox conditions, bioaccumulation of selected elements and human activity. Sediments of the Wilkostowo mire are located in the direct vicinity of an archaeological site, where traces of intensive settlement dating back to the Neolithic have been documented. The settlement phase is recorded both in lithology and geochemical properties of biogenic deposits which fill the reservoir formed at the bottom of the Parchania Canal Valley.

Radionuclides deposition and fine sediment transport in a forested watershed, central Japan

Science.gov (United States)

Nam, S.; Gomi, T.; Kato, H.; Tesfaye, T.; Onda, Y.

2011-12-01

We investigated radionuclides deposition and fine sediment transport in a 13 ha headwater watershed, Tochigi prefecture, located in 98.94 km north of Tokyo. The study site was within Karasawa experimental forest, Tokyo University of Agriculture and Technology. We conducted fingerprinting approach, based on the activities of fallout radionuclides, including caesium-134 (Cs-134) caesium-137 (Cs-137) and excess lead-210 (Pb-210ex). For indentifying specific sources of fine sediment, we sampled tree, soil on forested floor, soil on logging road surface, stream bed and stream banks. We investigated the radionuclides (i.e., as Cs-134, Cs-137 and Pb-210ex) deposition on tree after accident of nuclear power plants on March 11, 2011. We sampled fruits, leaves, branches, stems, barks on Japanese cedar (Sugi) and Japanese cypress (Hinoki). To analyze the samples, gammaray spectrometry was performed at a laboratory at the University of Tsukuba (Tsukuba City, Japan) using n-type coaxial low-energy HPGe gamma detectors (EGC-200-R and EGC25-195-R of EURYSIS Co., Lingolsheim, France) coupled with a multichannel analyzer. We also collected soil samples under the forest canopy in various soil depths from 2, 5, 10, 20, 30 cm along transect of hillslopes. Samples at forest road were collected road segments crossing on the middle section of monitoring watersheds. Fine sediment transport in the streams were collected at the outlet of 13 ha watersheds using integrated suspended sediment samplers. This study indicates the some portion of radio nuclide potentially remained on the tree surface. Part of the deposited radionuclides attached to soil particles and transported to the streams. Most of the fine sediment can be transported on road surface and/or near stream side (riparian zones).

Evidence for fat, oil, and grease (FOG) deposit formation mechanisms in sewer lines.

Science.gov (United States)

He, Xia; Iasmin, Mahbuba; Dean, Lisa O; Lappi, Simon E; Ducoste, Joel J; de los Reyes, Francis L

2011-05-15

The presence of hardened and insoluble fats, oil, and grease (FOG) deposits in sewer lines is a major cause of line blockages leading to sanitary sewer overflows (SSOs). Despite the central role that FOG deposits play in SSOs, little is known about the mechanisms of FOG deposit formation in sanitary sewers. In this study, FOG deposits were formed under laboratory conditions from the reaction between free fatty acids and calcium chloride. The calcium and fatty acid profile analysis showed that the laboratory-produced FOG deposit displayed similar characteristics to FOG deposits collected from sanitary sewer lines. Results of FTIR analysis showed that the FOG deposits are metallic salts of fatty acid as revealed by comparisons with FOG deposits collected from sewer lines and pure calcium soaps. Based on the data, we propose that the formation of FOG deposits occurs from the aggregation of excess calcium compressing the double layer of free fatty acid micelles and a saponification reaction between aggregated calcium and free fatty acids.

Lake-sediment record of PAH, mercury, and fly-ash particle deposition near coal-fired power plants in Central Alberta, Canada.

Science.gov (United States)

Barst, Benjamin D; Ahad, Jason M E; Rose, Neil L; Jautzy, Josué J; Drevnick, Paul E; Gammon, Paul R; Sanei, Hamed; Savard, Martine M

2017-12-01

We report a historical record of atmospheric deposition in dated sediment cores from Hasse Lake, ideally located near both currently and previously operational coal-fired power plants in Central Alberta, Canada. Accumulation rates of spheroidal carbonaceous particles (SCPs), an unambiguous marker of high-temperature fossil-fuel combustion, in the early part of the sediment record (pre-1955) compared well with historical emissions from one of North America's earliest coal-fired power plants (Rossdale) located ∼43 km to the east in the city of Edmonton. Accumulation rates in the latter part of the record (post-1955) suggested inputs from the Wabamun region's plants situated ∼17-25 km to the west. Increasing accumulation rates of SCPs, polycyclic aromatic hydrocarbons (PAHs) and Hg coincided with the previously documented period of peak pollution in the Wabamun region during the late 1960s to early 1970s, although Hg deposition trends were also similar to those found in western North American lakes not directly affected by point sources. A noticeable reduction in contaminant inputs during the 1970s is attributed in part to technological improvements and stricter emission controls. The over one hundred-year historical record of coal-fired power plant emissions documented in Hasse Lake sediments has provided insight into the impact that both environmental regulations and changes in electricity output have had over time. This information is crucial to assessing the current and future role of coal in the world's energy supply. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

Mineralogy, alteration patterns, geochemistry, and fluid properties of the Ag-Au epithermal deposit Nová Baňa, Slovakia

Science.gov (United States)

Majzlan, Juraj; Berkh, Khulan; Kiefer, Stefan; Koděra, Peter; Fallick, Anthony E.; Chovan, Martin; Bakos, František; Biroň, Adrián; Ferenc, Štefan; Lexa, Jaroslav

2018-02-01

In this contribution, we report new data on mineralogy, alteration patterns, geochemistry, fluid properties and source of fluids for the deposit Nová Baňa, one of the smaller epithermal deposits in the Middle Miocene Štiavnica andesite stratovolcano (Western Carpathians, Slovakia). Ore veins and the associated rocks were studied in samples from outcrops and old mines, grab samples, and bore holes from the central part of the deposit (ore structures Althandel, Jozef, Jakub, Vavrinec), northern part (Freischurf), SE part (Gupňa) and SW part (Šibeničný vrch). Pervasive hydrothermal alteration transformed the rock-forming minerals into a mixture of adularia and fine-grained quartz, with lesser amount of pyrite, Ti oxides and Fe oxides. This assemblage was further altered to omnipresent interstratified illite/smectite that was used in this study as a geothermometer, corroborating the results from the fluid inclusion work. Ore minerals comprise predominantly pyrite, sphalerite, galena but all sulfides are relatively sparse in the samples studied. Minerals of precious metals are electrum, Ag-tetrahedrite, acanthite, members of the polybasite-pearceite and pyrargyrite-proustite solid solution, and rare miargyrite, Hg-Ag tetrahedrite, and diaphorite. In the central part, we have found also some stibnite. In the SE part of the deposit, acanthite, uytenbogaardtite, and petrovskaite occur and seem to be related to supergene enrichment of the ores. In bulk ore samples, Zn usually dominates over Pb and Cu. The average Ag:Au ratio for the entire deposit is 64:1. The concentrations of precious metals in the grab samples reach maxima of 50 ppm Au and 570 ppm Ag in the SE part and 116 ppm Au and 1110 ppm Ag in the central part of the deposit. Fluid inclusions show signs of trapping of a heterogeneous fluid. In the central, northern and SE parts of the deposit, homogenization temperatures of 190-260 °C and consistently low salinities of minerals is recalculated to fluid

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.

Precipitation composition and wet deposition temporal pattern in Central Serbia for the period from 1998 to 2004.

Science.gov (United States)

Golobocanin, D; Zujić, A; Milenković, A; Miljević, N

2008-07-01

Bulk samples collected on a daily basis at three principal meteorological stations in central Serbia were analyzed on chloride (Cl(-)), nitrate (NO(3)(-)), sulfate (SO(4)(2-)), sodium (Na(+)), ammonium (NH(4)(+)), potassium (K(+)), calcium (Ca(2+)), and magnesium (Mg(2+)) in addition to precipitation amount, pH and conductivity measurements over the period 1998-2004. The data were subjected to variety of analyses (linear regression, principal component analysis, time series analysis) to characterize precipitation chemistry in the study area. The most abundant ion was SO(2-)(4) with annual volume weighted mean concentration of 242 microeq L(-1). Neutralization of precipitation acidity occurs both as a result of the dissolution of alkaline compounds containing Ca(2+), Mg(2+), and K(+) as well as the absorption of ammonia. The ratio of SO(4)(2-)/NO(3)(-) was above 5, which indicated that the combustion process of low-grade domestic lignite for electricity generation from coal-fired thermal power plants was the main source of pollution in the investigated area. A considerable mean annual bulk wet deposition of SO(4)-S determined by precipitation amount and concentrations of sulfate in the precipitation was calculated to be 12-35 kg ha(-1).

210Pb dating of sediments from the central and the northern Adriatic Sea: The deposition and preservation of sedimentary organic carbon

International Nuclear Information System (INIS)

Hamilton, T.; Fowler, S.; Miquel, J.C.; La Rosa, J.

1996-04-01

A central goal of the ELNA project is to assess the carbon assimilation capacity of the Northern Adriatic Sea. This requires fundamental quantitative information on budgets and sinks of organic carbon. Any change in carbon production in the water column should be reflected in the underlying sediments. Moreover, the fraction of particulate organic carbon reaching the sea floor which is subsequently preserved in the sediment will be strongly coupled to sediment accumulation and mixing. In this study a series of box cores were collected in order to characterize a hypothetical eutrophication gradient extending from the Po River outflow region in the north down to the shallow meso-Adriatic depression (Jabuka Pit). The main tasks assigned to IAEA-MEL were to provide 210 Pb derived sedimentation and dry-mass accumulation rates and to examine the possible correlations between sedimentary processes, the deposition and preservation of sedimentary organic carbon and pelagic primary productivity

The analytical investigation of temperature distribution in off-central ...

Indian Academy of Sciences (India)

central diode-pumped; diode-pumped; temperature distribution. ... In our model we consider a laser crystal of radius b and length L. Heat is deposited ..... [13] M Abramawitz and I A Stegun (eds), Handbook of mathematical function (Dover,.

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.

Atmospheric deposition of lead in Norway: spatial and temporal variation in isotopic composition

International Nuclear Information System (INIS)

Steinnes, E.; Aaberg, G.; Hjelmseth, H.

2005-01-01

Moss samples collected from 22 sites all over Norway at five different times during 1977-2000 were analysed for stable lead isotope ratios. These data together with total lead concentrations and relevant literature lead isotope data from UK, western/central Europe and eastern Europe/Russia were used to elucidate major source regions for lead deposited in different parts of the country at different times. The southernmost part of the country was most affected from western/central Europe around 1975, but the deposition declined rapidly and UK became a more significant source region in the 1980s. Recently, the influence is mostly from Eastern Europe. In the west, UK was the dominant source region during the whole period. In the middle and northern regions, the deposition was low but also decreasing regularly, and the main source region was probably the North Atlantic. In the far north-east, influence from Russia and eastern Europe was dominant during the whole period

Acid deposition and water use efficiency in Appalachian forests

Science.gov (United States)

Malcomb, J.

2017-12-01

Multiple studies have reported increases in forest water use efficiency in recent decades, but the drivers of these trends remain uncertain. While acid deposition has profoundly altered the biogeochemistry of Appalachian forests in the past century, its impacts on forest water use efficiency have been largely overlooked. Plant ecophysiology literature suggests that plants up-regulate transpiration in response to soil nutrient limitation in order to maintain sufficient mass flow of nutrients. To test the impacts of acid deposition on forest eco-hydrology in central Appalachia, we integrated dendrochronological techniques, including tree ring δ13C analysis, with catchment water balance data from the Fernow Experimental Forest in West Virginia. Tree cores from four species were collected in Fernow Watershed 3, which has received experimental ammonium sulfate additions since 1989, and Watershed 7, an adjacent control catchment. Initial results suggest that acidification treatments have not significantly influenced tree productivity compared to a control watershed, but the effect varies by species, with tulip poplar showing greatest sensitivity to acidification. Climatic water balance, defined as the difference between growing season precipitation and evapotranspiration, is significantly related to annual tree ring growth, suggesting that climate may be driving tree growth trends in chronically acidified Appalachian forests. Tree ring 13C analysis from Fernow cores is underway and these data will be integrated with catchment hydrology data from five other sites in central Appalachia and the U.S. Northeast, representing a range of forest types, soil base saturations, and acid deposition histories. This work will advance understanding of how climate and acid deposition interact to influence forest productivity and water use efficiency, and improve our ability to model carbon and water cycling in forested ecosystems impacted by acid deposition.

Spectral Unmixing Modeling of the Aristarchus Pyroclastic Deposit: Assessing the Eruptive History of Glass-Rich Regional Lunar Pyroclastic Deposits

Science.gov (United States)

Jawin, E. R.; Head, J. W., III; Cannon, K.

2017-12-01

The Aristarchus pyroclastic deposit in central Oceanus Procellarum is understood to have formed in a gas-rich explosive volcanic eruption, and has been observed to contain abundant volcanic glass. However, the interpreted color (and therefore composition) of the glass has been debated. In addition, previous analyses of the pyroclastic deposit have been performed using lower resolution data than are currently available. In this work, a nonlinear spectral unmixing model was applied to Moon Mineralogy Mapper (M3) data of the Aristarchus plateau to investigate the detailed mineralogic and crystalline nature of the Aristarchus pyroclastic deposit by using spectra of laboratory endmembers including a suite of volcanic glasses returned from the Apollo 15 and 17 missions (green, orange, black beads), as well as synthetic lunar glasses (orange, green, red, yellow). Preliminary results of the M3 unmixing model suggest that spectra of the pyroclastic deposit can be modeled by a mixture composed predominantly of a featureless endmember approximating space weathering and a smaller component of glass. The modeled spectra were most accurate with a synthetic orange glass endmember, relative to the other glasses analyzed in this work. The results confirm that there is a detectable component of glass in the Aristarchus pyroclastic deposit which may be similar to the high-Ti orange glass seen in other regional pyroclastic deposits, with only minimal contributions of other crystalline minerals. The presence of volcanic glass in the pyroclastic deposit, with the low abundance of crystalline material, would support the model that the Aristarchus pyroclastic deposit formed in a long-duration, hawaiian-style fire fountain eruption. No significant detection of devitrified black beads in the spectral modeling results (as was observed at the Apollo 17 landing site in the Taurus-Littrow pyroclastic deposit), suggests the optical density of the eruptive plume remained low throughout the

Mineralogy and geochemistry of bauxite and bentonite deposits from Mozambique

NARCIS (Netherlands)

Dos Muchangos, A.C.

2000-01-01

Results of mineralogical and geochemical studies of bauxites, kaolinitic clays and bentoniteS from Mozambique are presented in this thesis. The bauxite and kaolinitic clay deposits in Penhalonga area (in the central western part of Mozambique) are associated with Precambrian magmatic rocks and

Short-term seasonal variability in 7Be wet deposition in a semiarid ecosystem of central Argentina

International Nuclear Information System (INIS)

Juri Ayub, J.; Di Gregorio, D.E.; Velasco, H.; Huck, H.; Rizzotto, M.; Lohaiza, F.

2009-01-01

The 7 Be wet deposition has been intensively investigated in a semiarid region at San Luis Province, Argentina. From November 2006 to May 2008, the 7 Be content in rainwater was determined in 58 individual rain events, randomly comprising more than 50% of all individual precipitations at the sampling period. 7 Be activity concentration in rainwater ranged from 0.7 ± 0.3 Bq l -1 to 3.2 ± 0.7 Bq l -1 , with a mean value of 1.7 Bq l -1 (sd = 0.53 Bq l -1 ). No relationship was found between 7 Be content in rainwater and (a) rainfall amount, (b) precipitation intensity and (c) elapsed time between events. 7 Be ground deposition was found to be well correlated with rainfall amount (R = 0.92). For the precipitation events considered, the 7 Be depositional fluxes ranged from 1.1 to 120 Bq m -2 , with a mean value of 32.7 Bq m -2 (sd = 29.9 Bq m -2 ). The annual depositional flux was estimated at 1140 ± 120 Bq m -2 y -1 . Assuming the same monthly deposition pattern and that the 7 Be content in soil decreases only through radioactive decay, the seasonal variation of 7 Be areal activity density in soil was estimated. Results of this investigation may contribute to a valuable characterization of 7 Be input in the explored semiarid ecosystem and its potential use as tracer of environmental processes.

SEM/EDS characterisation of dusty deposits in precipitation and assessment of their origin

Directory of Open Access Journals (Sweden)

Miloš Miler

2014-07-01

Full Text Available Detailed scanning electron microscopy/energy dispersive spectroscopy (SEM/EDS analysis of dusty material in rainfall residue, deposited and collected on February 19th 2014 in Ljubljana, was carried out with the intention to characterise it according to its chemical and mineral composition and to assess its origin. The material consists of poorly sorted and sharp-edged particles of mostly very fine-grained silt and clay fractions, which is consistent with long-range aerial transport. Particles are represented by illite, chlorite and kaolinite group clay minerals, quartz, feldspars, carbonates, accessory minerals and secondary Fe-oxy-hydroxide minerals. Quantities of minerals and illite/ kaolinite ratio (4.5 correspond to dusts in rainfall residues originating from Moroccan Atlas, while chlorite/kaolinite ratio (2.8 agrees better with dust from central Libya. The element ratios Al/Si, Ca/Al, K/Ca, Mg/Al, Fe/Al and (Ca+Mg/Fe in the studied dusty deposit are in good agreement with ratios in dusts from rainfall residues originating from Morocco and northern Mauritania. This was also confirmed by the trajectories of cloud movement that caused precipitation with dusty deposit, although the back trajectory HYSPLIT simulation of air masses indicated northern Mauritania, central Niger, southern Algeria, southwestern and central Libya as the most possible source regions.

Uranium mineralization in the central region of Cuba

International Nuclear Information System (INIS)

Valdez, M.G.; Olivera, J.; Fernandez, P.

1995-01-01

The present work shows different geological and geophysical index for uranium mineralization found at Loma Alta iron ore deposit, located in the central region of Cuba. In this deposit was carried out pull work of iron ore. The tunnels were radiometrically documented in the wall and the floor observing some anomalies of the gamma ray intensity (up to 1700 c.p.s.) associated with the poor iron ore. In those points were collected solid sample. The obtained results were very important (uranium concentrations values up to 3500 ppm)

Sandstone uranium deposits of Eurasia – from genetic concepts to forecasting and new discoveries

International Nuclear Information System (INIS)

Pechenkin, I.

2014-01-01

Along the Eurasian continent’s southern borders lie uranium ore provinces and regions controlling medium-sized and, on rare occasions, large sandstone deposits. Central French, Eastern Rhodope and other regions are known in the west. Large uranium ore provinces were discovered in the south of the Turan Plate and in the depressions of South Kazakhstan, viz. Central Kyzyl Kum, Syr Darya, Chu Sarysu. A common criterion has been established for all objects of the sandstone type, located in oil and gas, coal etc. sedimentary basins – the zone of interlayer or ground-interlayer oxidation, controlling uranium mineralization. In 2003 we were able to justify the concept that the formation of giant deposits in Chu Sarysu province was caused by the collision between the Indian Plate and the southern part of the Eurasian continent. Within the limits of Pacific ore belt there is a zonal distribution of ore deposits. Ordinary mineralization is drawn towards its eastern fringe: gold, tin, copper, tungsten etc. Volcanic and tectonic structures of central type of Mesozoic age are located further west, from the north to the south, that is large calderas – Streltsovskaya (Russia), Dornot (Mongolia), Sian Shan (China), which control large and unique endogene uranium deposits. In the far west, in the region of subsiding tectonic tensions, there are sandstone deposits of uranium in Transbaikalia, Mongolia and Yunnan, which are specially connected to young basalts. Infiltration deposits of Vitim region are adjacent to endogene deposits of Streltsovsky region in the southern-easterly direction, and to the east of the deposits of Yunnan at the same latitude lay the Sian Shan caldera with geothermal deposits of uranium and other metals. We combined them into the unified submeridional Baikal-Southern China uranium ore belt. After examining the southern extremities of the Eurasian continent, the region of the collision of the Indian Plate, a distinct similarity can be perceived between

137Cs deposition in peat profiles on a raised bog in central Sweden

International Nuclear Information System (INIS)

Rosen, K.; Vinichuk, M.; Galan, P.R.; Johanson, K.J.

2009-01-01

Distribution of 137 Cs depositions within peat profiles in open bog and nearby (low pine) sites in raised bog are shown and discussed. A possible involvement of Sphagnum moss in radionuclide binding and retention in such nutrient poor ecosystem is suggested. (au)

The Kalatongke magmatic Ni-Cu deposits in the Central Asian Orogenic Belt, NW China: product of slab window magmatism?

Science.gov (United States)

Li, Chusi; Zhang, Mingjie; Fu, Piaoer; Qian, Zhuangzhi; Hu, Peiqing; Ripley, Edward M.

2012-01-01

The Permian Kalatongke Ni-Cu deposits in the Central Asian Orogenic Belt are among the most important Ni-Cu deposits in northern Xinjiang, western China. The deposits are hosted by three small mafic intrusions comprising mainly norite and diorite. Its tectonic context, petrogenesis, and ore genesis have been highly contested. In this paper, we present a new model involving slab window magmatism for the Kalatongke intrusions. The origin of the associated sulfide ores is explained in the context of this new model. Minor amounts of olivine in the intrusions have Fo contents varying between 71 and 81.5 mol%, which are similar to the predicted values for olivine crystallizing from coeval basalts in the region. Analytic modeling based on major element concentrations suggests that the parental magma of the Kalatongke intrusions and the coeval basalts represent fractionated liquids produced by ˜15% of olivine crystallization from a primary magma, itself produced by 7-8% partial melting of depleted mantle peridotite. Positive ɛ Nd values (+4 to +10) and significant negative Nb anomalies for both intrusive and extrusive rocks can be explained by the mixing of magma derived from depleted mantle with 6-18% of a partial melt derived from the lower part of a juvenile arc crust with a composition similar to coeval A-type granites in the region, plus up to 10% contamination with the upper continental crust. Our model suggests that a slab window was created due to slab break-off during a transition from oceanic subduction to arc-arc or arc-continent collision in the region in the Early Permian. Decompression melting in the upwelling oceanic asthenosphere produced the primary magma. When this magma ascended to pond in the lower parts of a juvenile arc crust, it underwent olivine crystallization and at the same time triggered partial melting of the arc crust. Mixing between these two magmas followed by contamination with the upper crust after the magma ascended to higher crustal

Slowly rotating general relativistic superfluid neutron stars with relativistic entrainment

International Nuclear Information System (INIS)

Comer, G.L.

2004-01-01

Neutron stars that are cold enough should have two or more superfluids or supercondutors in their inner crusts and cores. The implication of superfluidity or superconductivity for equilibrium and dynamical neutron star states is that each individual particle species that forms a condensate must have its own, independent number density current and equation of motion that determines that current. An important consequence of the quasiparticle nature of each condensate is the so-called entrainment effect; i.e., the momentum of a condensate is a linear combination of its own current and those of the other condensates. We present here the first fully relativistic modeling of slowly rotating superfluid neutron stars with entrainment that is accurate to the second-order in the rotation rates. The stars consist of superfluid neutrons, superconducting protons, and a highly degenerate, relativistic gas of electrons. We use a relativistic σ-ω mean field model for the equation of state of the matter and the entrainment. We determine the effect of a relative rotation between the neutrons and protons on a star's total mass, shape, and Kepler, mass-shedding limit

Depositional environments of the uranium bearing Cutler Formations, Lisbon Valley, Utah

International Nuclear Information System (INIS)

Campbell, J.A.; Steele-Mallory, B.A.

1979-01-01

The Cutler Formation in Lisbon Valley, San Juan County, Utah, is composed predominantly of fluvial arkosic sandstones, siltstones, shales, and mudstones that were deposited by meandering streams that flowed across a flood plain and tidal flat close to sea level. Two types of channel deposits are recognized from their sedimentary structures: meandering and distributary. The flood plain was occasionally transgressed by a shallow sea from the west, resulting in the deposition of several thin limestones and marine sandstones. The marine sandstones were deposited as longshore bars. Wind transported sand along the shoreline of the shallow sea, forming a coastal dune field. Marine sandstones and eolian sandstones are more common in the upper Cutler in the southern part of the area, whereas in the central and northern part of the area the formation is predominantly fluvial. Crossbed orientation indicates that Cutler streams flowed S. 67 0 W. on the average, whereas marine currents moved sediment S. 36 0 E. and N. 24 0 W., and wind transported sand S. 80 0 E. The uranium in the Cutler is found in the central and northern part of the area, in the upper part of the formation, in small fluvial sandstone bodies that were deposited predominantly in a distributary environment. No uranium is known in the marine or eolian sandstones. Petrographically, the uranium-bearing sandstones are identical to other Cutler fluvial sandstones except that they contain less calcite and more clay and are slightly coarser grained. Ore formation has modified the host sandstones very little

Depositional environments of the uranium-bearing Cutler Formations, Lisbon Valley, Utah

Science.gov (United States)

Campbell, John A.; Steele-Mallory, Brenda A.

1979-01-01

The Cutler Formation in Lisbon Valley, San Juan County, Utah, is composed predominantly of fluvial arkosic sandstones, siltstones, shales, and mudstones that were deposited by meandering streams that flowed across a flood plain and tidal flat close to sea level. Two types of channel deposits are recognized from their sedimentary structures: meandering and distributary. The flood plain was occasionally transgressed by a shallow sea from the west, resulting in the deposition of several thin limestones and marine sandstones. The marine sandstones were deposited as longshore bars. Wind transported sand along the shoreline of the shallow sea, forming a coastal dune field. Marine sandstones and eolian sandstones are more common in the upper Cutler in the southern part of the area, whereas in the central and northern part of the area the formation is predominantly fluvial. Crossbed orientation indicates that Cutler streams flowed S. 67? W. on the the average, whereas marine currents moved sediment S. 36? E. and N. 24? W., and wind transported sand S. 800 E. The uranium in the Cutler is found in the central and northern part of the area, in the upper part of the formation, in small fluvial sandstone bodies that were deposited predominantly in a distributary environment. No uranium is known in the marine or eolian sandstones. Petrographically, the uranium-bearing sandstones are identical to other Cutler fluvial sandstones except that they contain less calcite and more clay and are slightly coarser grained. Ore formation has modified the host sandstones very little.

Droplet model of pyrocarbon deposition from the gas phase. [HTGR

Energy Technology Data Exchange (ETDEWEB)

Linke, J; Koizlik, K; Luhleich, H; Nickel, H

1975-01-15

Based on extensive earlier work a model has been developed to describe the formation of carbon by pyrolysis of gaseous hydrocarbons. One of the central statements of this model is the assumption of the existence of a quasi liquid carbon phase during deposition process.This model is described and is discussed as are the consequences for the material properties and structural parameters which arise from it. To review the droplet model, statically deposited pyrocarbon is examined by characterization methods suitable to analyze just these structural parameters.The results prove the model conceptions to be realistic.

Nebulization and selective deposition of LTD4 in human lungs

DEFF Research Database (Denmark)

Bisgaard, H; Poulsen, L; Søndergaard, I

1987-01-01

volunteers were challenged on separate days with 40 nmol LTD4 or 100 mumol histamine, and the changes in FEV1 and partial flow volume curves initiated at 50% of vital capacity (Vmax30) were measured. A relative diffuse deposition pattern was ensured by inhalation via a settling bag. These results were...... changed in parallel when the deposition of the mediators was changed to a more central pattern. This indicates that the two mediators do not differ with respect to any selective effects on different parts of the airways....

Genesis of the Abu Marawat gold deposit, central Eastern Desert of Egypt

Science.gov (United States)

Zoheir, Basem A.; Akawy, Ahmed

2010-06-01

Gold mineralisation at the Abu Marawat mine, central Eastern Desert of Egypt, is related to a system of massive and sheared, milky quartz veins cutting a sequence of Neoproterozoic island arc metavolcanic/volcaniclastic rocks and related banded iron formation (BIF). Sulphide-bearing quartz veins and related hydrothermal breccia bodies display a range of textures including sheared, boudinaged and recrystallised quartz, open space filling and microbreccia. These variable textures imply a complex history of crack-seal mechanism characterising the relation between mineral deposition and a major N-S-trending shear zone, during a late brittle-ductile deformation event which affected the area at about 550 Ma. Gold-base metal mineralisation is associated with brecciation and fracturing of the iron ore bands, close to silicified shears and related quartz veins. The auriferous quartz lodes are characterised by the occurrence of visible pyrite-chalcopyrite ± pyrrhotite ± sphalerite ± galena mineralisation. Gold is refractory in pyrite and chalcopyrite, but rare visible gold/electrum and telluride specks were observed in a few samples. Hydrothermal alteration includes pervasive silicification, pyritisation, sericitisation, carbonatisation confined to a delicate set of veins and altered shears, and a more widespread propylitic alteration assemblage (quartz + chlorite + pyrite + calcite ± epidote). Fluid inclusion petrography and microthermometric studies suggest heterogeneous trapping of a low-salinity (1.4-6.7 wt.% eq. NaCl) aqueous solution and a carbonic fluid. Evidence for fluid immiscibility during ore formation includes variable liquid/vapour ratios in inclusions along individual trails and bulk inclusion homogenisation into liquid and occasionally to vapour at comparable temperatures. The trapping conditions of intragranular aqueous-carbonic inclusions approximate 264-378 °C at 700-1300 bar. Similar temperature estimates have been obtained from Al

Mycobacterium talmoniae sp. nov., a slowly growing mycobacterium isolated from human respiratory samples.

Science.gov (United States)

Davidson, Rebecca M; DeGroote, Mary Ann; Marola, Jamie L; Buss, Sarah; Jones, Victoria; McNeil, Michael R; Freifeld, Alison G; Elaine Epperson, L; Hasan, Nabeeh A; Jackson, Mary; Iwen, Peter C; Salfinger, Max; Strong, Michael

2017-08-01

A novel slowly growing, non-chromogenic species of the class Actinobacteria was isolated from a human respiratory sample in Nebraska, USA, in 2012. Analysis of the internal transcribed spacer sequence supported placement into the genus Mycobacterium with high sequence similarity to a previously undescribed strain isolated from a patient respiratory sample from Oregon, USA, held in a collection in Colorado, USA, in 2000. The two isolates were subjected to phenotypic testing and whole genome sequencing and found to be indistinguishable. The bacteria were acid-fast stain-positive, rod-shaped and exhibited growth after 7-10 days on solid media at temperatures ranging from 25 to 42°C. Colonies were non-pigmented, rough and slightly raised. Analyses of matrix-assisted laser desorption ionization time-of-flight profiles showed no matches against a reference library of 130 mycobacterial species. Full-length 16S rRNA gene sequences were identical for the two isolates, the average nucleotide identity (ANI) between their genomes was 99.7 % and phylogenetic comparisons classified the novel mycobacteria as the basal most species in the slowly growing Mycobacterium clade. Mycobacterium avium is the most closely related species based on rpoB gene sequence similarity (92 %), but the ANI between the genomes was 81.5 %, below the suggested cut-off for differentiating two species (95 %). Mycolic acid profiles were more similar to M. avium than to Mycobacterium simiae or Mycobacterium abscessus. The phenotypic and genomic data support the conclusion that the two related isolates represent a novel Mycobacterium species for which the name Mycobacterium talmoniae sp. nov. is proposed. The type strain is NE-TNMC-100812T (=ATCC BAA-2683T=DSM 46873T).

Mitigating mass movement caused by earthquakes and typhoons: a case study of central Taiwan

Science.gov (United States)

Lin, Jiun-Chuan

2013-04-01

Typhoons caused huge damages to Taiwan at the average of 3.8 times a year in the last 100 years, according to Central Weather Bureau data. After the Chi-Chi earthquake of 1999 at the magnitude of Richard Scale 7.3, typhoons with huge rainfall would cause huge debris flow and deposits at river channels. As a result of earthquakes, loose debris falls and flows became significant hazards in central Taiwan. Analysis of rainfall data and data about the sites of slope failure show that damage from natural hazards was enhanced in the last 20 years, as a result of the Chi-Chi earthquake. There are three main types of mass movement in Central Taiwan: landslides, debris flows and gully erosion. Landslides occurred mainly along hill slopes and river channel banks. Many dams, check dams, housing structures and even river channels can be raised to as high as 60 meters as a result of stacking up floating materials of landslides. Debris flows occurred mainly through typhoon periods and activated ancient debris deposition. New gullies were thus developed from deposits loosened and shaken up by earthquakes. Extreme earthquakes and typhoon events occurred frequently in the last 20 years. This paper analyzes the geological and geomorphologic background for the precarious areas and typhoons in central Taiwan, to make a systematic understanding of mass movement harzards. The mechanism and relations of debris flows and rainfall data in central Taiwan are analyzed. Ways for mitigating mass movement threats are also proposed in this paper. Keywords: mass movement, earthquakes, typhoons, hazard mitigation, central Ta

Dynamical bifurcation in a system of coupled oscillators with slowly varying parameters

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Igor Parasyuk

2016-08-01

Full Text Available This paper deals with a fast-slow system representing n nonlinearly coupled oscillators with slowly varying parameters. We find conditions which guarantee that all omega-limit sets near the slow surface of the system are equilibria and invariant tori of all dimensions not exceeding n, the tori of dimensions less then n being hyperbolic. We show that a typical trajectory demonstrates the following transient process: while its slow component is far from the stationary points of the slow vector field, the fast component exhibits damping oscillations; afterwards, the former component enters and stays in a small neighborhood of some stationary point, and the oscillation amplitude of the latter begins to increase; eventually the trajectory is attracted by an n-dimesional invariant torus and a multi-frequency oscillatory regime is established.

Slowly evolving connectivity in recurrent neural networks: I. The extreme dilution regime

International Nuclear Information System (INIS)

Wemmenhove, B; Skantzos, N S; Coolen, A C C

2004-01-01

We study extremely diluted spin models of neural networks in which the connectivity evolves in time, although adiabatically slowly compared to the neurons, according to stochastic equations which on average aim to reduce frustration. The (fast) neurons and (slow) connectivity variables equilibrate separately, but at different temperatures. Our model is exactly solvable in equilibrium. We obtain phase diagrams upon making the condensed ansatz (i.e. recall of one pattern). These show that, as the connectivity temperature is lowered, the volume of the retrieval phase diverges and the fraction of mis-aligned spins is reduced. Still one always retains a region in the retrieval phase where recall states other than the one corresponding to the 'condensed' pattern are locally stable, so the associative memory character of our model is preserved

Geology of Crownpoint Sec. 29 uranium deposit, McKinley County

International Nuclear Information System (INIS)

Wentworth, D.W.; Porter, D.A.; Jensen, H.N.

1980-01-01

The Crownpoint Sec. 29 deposit, located in the west-central part of the Grants mineral belt, represents a relatively recent uranium discovery in the Westwater Canyon Member (Jurassic) of the Morrison Formation. This deposit, estimated as containing up to 10 million pounds of uranium oxide, occurs in four vertically separate sandstone units. The average depth of the ore mineralization is approximately 2,000 ft (610 m) below the ground surface. Present-day structure of the Crownpoint Sec. 29 area is relatively simple and consists of gentle north-northeast-dipping strata with no known faulting. This deposit is located in an east-southeast-trending Westwater Canyon depocenter, whose course is believed to have been influenced by subtle Jurassic structure, which was penecontemporaneous with sedimentation. The deposit has been delineated by drilling on 200-ft (60-m) centers, involving approximately 348 holes and is awaiting shaft sinking and mine development

Soils and late-Quaternary landscape evolution in the Cottonwood River basin, east-central Kansas: Implications for archaeological research

Science.gov (United States)

Beeton, J.M.; Mandel, R.D.

2011-01-01

Temporal and spatial patterns of landscape evolution strongly influence the temporal and spatial patterns of the archaeological record in drainage systems. In this geoarchaeological investigation we took a basin-wide approach in assessing the soil stratigraphy, lithostratigraphy, and geochronology of alluvial deposits and associated buried soils in the Cottonwood River basin of east-central Kansas. Patterns of landscape evolution emerge when stratigraphic sequences and radiocarbon chronologies are compared by stream size and landform type. In the valleys of high-order streams (???4th order) the Younger Dryas Chronozone (ca. 11,000-10,000 14C yr B.P.) was characterized by slow aggradation accompanied by pedogenesis, resulting in the development of organic-rich cumulic soils. Between ca. 10,000 and 4900 14C yr B.P., aggradation punctuated by soil formation was the dominant process in those valleys. Alluvial fans formed on the margins of high-order stream valleys during the early and middle Holocene (ca. 9000-5000 14C yr B.P.) and continued to develop slowly until ca. 3000-2000 14C yr B.P. The late-Holocene record of high-order streams is characterized by episodes of entrenchment, rapid aggradation, and slow aggradation punctuated by soil development. By contrast, the early and middle Holocene (ca. 10,000-5000 14C yr B.P.) was a period of net erosion in the valleys of low-order streams. However, during the late Holocene small valleys became zones of net sediment storage. Consideration of the effects of these patterns of landscape evolution on the archaeological record is crucial for accurately interpreting that record and searching for buried archaeological deposits dating to specific cultural periods. ?? 2011 Wiley Periodicals, Inc. ?? 2011 Wiley Periodicals, Inc..

Chronic central serous choroidopathy with severe visual loss in hyperopic microphthalmic identical twins

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Fabry, Annelies

2011-01-01

Full Text Available Objective: To report chronic central serous choroidopathy with severe visual loss in hyperopic microphthalmic identical twins. Methods: The index patient was first examined in 1994, at age 31, and has been followed up closely for 17 years. He had repeated fluorescein and indocyanine green angiograms, OCT, ultrasound biometry, and recently also autofluorescence and EDI OCT. His twin brother was first examined in 2010, at age 47, and had a similar extensive exploration. Results: The index patient had a mean refractive error of +6 D OU and VA was 20/32++ in the RE and 20/200 in the LE in 1994. Vision slowly went down to 20/800+ in the RE and 20/600 in the LE in 2011. His twin brother has a mean refractive error of +6 D OU and VA 20/400 OU. Both have a short axial length of the eye, a thick choroid with dilated vessels, and central serous choroidopathy with cystic degeneration of the macula and retina in the posterior pole. Conclusions: We add to the reported complications of microphthalmos, chronic central serous choroidopathy.

Colloidal Asphaltene Deposition and Aggregation in Capillary Flow: Experiments and Mesoscopic Simulation

Science.gov (United States)

Boek, Edo S.; Ladva, Hemant K.; Crawshaw, John P.; Padding, Johan T.

2008-07-01

The aggregation and deposition of colloidal asphaltene in reservoir rock is a significant problem in the oil industry. To obtain a fundamental understanding of this phenomenon, we have studied the deposition and aggregation of colloidal asphaltene in capillary flow by experiment and simulation. For the simulation, we have used the stochastic rotation dynamics (SRD) method, in which the solvent hydrodynamic emerges from the collisions between the solvent particles, while the Brownian motion emerges naturally from the interactions between the colloidal asphaltene particles and the solvent. The asphaltene colloids interact through a screened Coulomb potential. We vary the well depth ɛ∝ and the flow rate v to obtain Peflow≫1 (hydrodynamic interactions dominate) and Re≪1 (Stokes flow). In the simulations, we impose a pressure drop over the capillary length and measure the corresponding solvent flow rate. We observe that the transient solvent flow rate decreases when the asphaltene particles become more "sticky". For a well depth ɛ∝ = 2kBT, a monolayer deposits on the capillary wall. With an increasing well depth, the capillary becomes totally blocked. The clogging is transient for ɛ∝ = 5kBT, but appears to be permanent for ɛ∝ = 10-20 kBT. We compare our simulation results with flow experiments in glass capillaries, where we use extracted asphaltenes in toluene, reprecipitated with n-heptane. In the experiments, the dynamics of asphaltene precipitation and deposition were monitored in a slot capillary using optical microscopy under flow conditions similar to those used in the simulation. Maintaining a constant flow rate of 5 μL min-1, we found that the pressure drop across the capillary first increased slowly, followed by a sharp increase, corresponding to a complete local blockage of the capillary. Doubling the flow rate to 10 μL min-1, we observe that the initial deposition occurs faster but the deposits are subsequently entrained by the flow. We

Mercato monetario, banche e nuove procedure di controllo della banca centrale

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Maria Luisa Marinelli

2012-04-01

Full Text Available Does central bank keep the control of bank deposits and bank rates by influ-encing the very short interest rate (overnight on the money market? The article focuses on liquidity management under two different bank ap-proaches. If bank is a creator of deposits, bank liquidity management influences bank rates, but deposits (money tend to become endogenous. While, if bank operates as intermediary among competitive markets, either bank rates or deposits are endogenously determined, and monetary rates become the price that equilibrate banking activity. Official rate adjustments have only the function of signalling the new range of equilibrating rates to banking operators.  JEL Codes: E51, E52 

[Clinico-psychological features of patients with favorable outcomes of slowly-progressive juvenile schizophrenia].

Science.gov (United States)

Tsutsul'kovskaia, M Ia; Bil'zho, A G; Kritskaia, V P; Meleshko, T K

1986-01-01

A follow-up study of patients with favourable outcomes of juvenile slowly progressing schizophrenia at the level of clinical cure (n = 84) revealed a number of clinical characteristics in the pattern of personality changes which correlated with a high level of the patients' social and occupational adaptation. The authors also determined external factors contributing to the achievement and stabilization of the "clinical cure" status. An experimental and psychological examination of these patients revealed finer mechanisms contributing to their social adaptation. These are high motivation of activities, compliance with social norms, a high level of voluntary regulation of activity and self-regulation, as well as the ability to overcome autistic trends in situations of interpersonal activities and cooperation.

Isolated, slowly evolving, and dynamical trapping horizons: Geometry and mechanics from surface deformations

International Nuclear Information System (INIS)

Booth, Ivan; Fairhurst, Stephen

2007-01-01

We study the geometry and dynamics of both isolated and dynamical trapping horizons by considering the allowed variations of their foliating two-surfaces. This provides a common framework that may be used to consider both their possible evolutions and their deformations as well as derive the well-known flux laws. Using this framework, we unify much of what is already known about these objects as well as derive some new results. In particular we characterize and study the ''almost isolated'' trapping horizons known as slowly evolving horizons. It is for these horizons that a dynamical first law holds and this is analogous and closely related to the Hawking-Hartle formula for event horizons

Niobium thin film coating on a 500-MHz copper cavity by plasma deposition

Energy Technology Data Exchange (ETDEWEB)

Haipeng Wang; Genfa Wu; H. Phillips; Robert Rimmer; Anne-Marie Valente; Andy Wu

2005-05-16

A system using an Electron Cyclotron Resonance (ECR) plasma source for the deposition of a thin niobium film inside a copper cavity for superconducting accelerator applications has been designed and is being constructed. The system uses a 500-MHz copper cavity as both substrate and vacuum chamber. The ECR plasma will be created to produce direct niobium ion deposition. The central cylindrical grid is DC biased to control the deposition energy. This paper describes the design of several subcomponents including the vacuum chamber, RF supply, biasing grid and magnet coils. Operational parameters are compared between an operating sample deposition system and this system. Engineering work progress toward the first plasma creation will be reported here.

India's manganese nodule mine site in the Central Indian Ocean

Digital Repository Service at National Institute of Oceanography (India)

Banakar, V.K.

This commentary highlights the activities of massive exploration programme for manganese nodule deposits in the Central Indian Basin located 5 km below the ocean surface and India's claim for mine site development and registration with UNCLOS...

Deposition of aluminium nanoparticles using dense plasma focus device

International Nuclear Information System (INIS)

Devi, Naorem Bilasini; Srivastava, M P; Roy, Savita

2010-01-01

Plasma route to nanofabrication has drawn much attention recently. The dense plasma focus (DPF) device is used for depositing aluminium nanoparticles on n-type Si (111) wafer. The plasma chamber is filled with argon gas and evacuated at a pressure of 80 Pa. The substrate is placed at distances 4.0 cm, 5.0 cm and 6.0 cm from the top of the central anode. The aluminium is deposited on Si wafer at room temperature with two focused DPF shots. The deposits on the substrate are examined for their morphological properties using atomic force microscopy (AFM). The AFM images have shown the formation of aluminium nanoparticles. From the AFM images, it is found that the size of aluminium nanoparticles increases with increase in distance between the top of anode and the substrate for same number of DPF shots.

Suppressed beta relaxations and reduced heat capacity in ultrastable organic glasses prepared by physical vapor deposition

Science.gov (United States)

Ediger, Mark

Glasses play an important role in technology as a result of their macroscopic homogeneity (e.g., the clarity of window glass) and our ability to tune properties through composition changes. A problem with liquid-cooled glasses is that they exhibit marginal kinetic stability and slowly evolve towards lower energy glasses and crystalline states. In contrast, we have shown that physical vapor deposition can prepare glasses with very high kinetic stability. These materials have properties expected for ``million-year-old'' glasses, including high density, low enthalpy, and high mechanical moduli. We have used nanocalorimetry to show that these high stability glasses have lower heat capacities than liquid-cooled glasses for a number of molecular systems. Dielectric relaxation has been used to show that the beta relaxation can be suppressed by nearly a factor of four in vapor-deposited toluene glasses, indicating a very tight packing environment. Consistent with this view, computer simulations of high stability glasses indicate reduced Debye-Waller factors. These high stability materials raise interesting questions about the limiting properties of amorphous packing arrangements.

Effect of Simulated N Deposition on Soil Exchangeable Cations in Three Forest Types of Subtropical China

Institute of Scientific and Technical Information of China (English)

LU Xian-Kai; MO Jiang-Ming; P.GUNDERSERN; ZHU Wei-Xing; ZHOU Guo-Yi; LI De-Jun; ZHANG Xu

2009-01-01

The effects of simulated nitrogen (N) deposition on soil exchangeable cations were studied in three forest types of subtropical China.Four N treatments with three replications were designed for the monsoon evergreen broadleaf forest (mature forest):control (0 kg N ha-1 year-1),low N (50 kg N ha-1 year-1),medium N (100 kg N ha-1 year-1) and high N (150 kg N ha-1 ycar-1),and only three treatments (i.e.,control,low N,medium N) were established for the pine and mixed forests.Nitrogen had been applied continuously for 26 months before the measurement.The mature forest responded more rapidly and intensively to N additions than the pine and mixed forests,and exhibited some significant negative symptoms,e.g.,soil acidification,Al mobilization and leaching of base cations from soil.The pine and mixed forests responded slowly to N additions and exhibited no significant response of soil cations.Response of soil exchangeable cations to N deposition varied in the forests of subtropical China,depending on soil N status and land-nse history.

Bilateral Pneumothoraces Following Central Venous Cannulation

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F. Pazos

2009-01-01

Full Text Available We report the occurrence of a bilateral pneumothoraces after unilateral central venous catheterization of the right subclavian vein in a 70-year-old patient. The patient had no history of pulmonary or pleural disease and no history of cardiothoracic surgery. Two days earlier, she had a median laparotomy under general and epidural anaesthesia. Prior to the procedure, the patient was hemodynamically stable and her transcutaneous oxygen saturation was 97% in room air. We punctured the right pleural space before cannulation of the right subclavian vein. After the procedure, the patient slowly became hemodynamically instable with respiratory distress. A chest radiograph revealed a complete left-side pneumothorax and a mild right-side pneumothorax. The right-side pneumothorax became under tension after left chest tube insertion. The symptoms finally resolved after insertion of a right chest tube. After a diagnostic work-up, we suspect a congenital “Buffalo chests” explaining bilateral pneumothoraces and a secondary tension pneumothorax.

Bilateral Pneumothoraces Following Central Venous Cannulation

Science.gov (United States)

Pazos, F.; Masterson, K.; Inan, C.; Robert, J.; Walder, B.

2009-01-01

We report the occurrence of a bilateral pneumothoraces after unilateral central venous catheterization of the right subclavian vein in a 70-year-old patient. The patient had no history of pulmonary or pleural disease and no history of cardiothoracic surgery. Two days earlier, she had a median laparotomy under general and epidural anaesthesia. Prior to the procedure, the patient was hemodynamically stable and her transcutaneous oxygen saturation was 97% in room air. We punctured the right pleural space before cannulation of the right subclavian vein. After the procedure, the patient slowly became hemodynamically instable with respiratory distress. A chest radiograph revealed a complete left-side pneumothorax and a mild right-side pneumothorax. The right-side pneumothorax became under tension after left chest tube insertion. The symptoms finally resolved after insertion of a right chest tube. After a diagnostic work-up, we suspect a congenital “Buffalo chests” explaining bilateral pneumothoraces and a secondary tension pneumothorax. PMID:19901997

Porphyry copper assessment of western Central Asia: Chapter N in Global mineral resource assessment

Science.gov (United States)

Berger, Byron R.; Mars, John L.; Denning, Paul; Phillips, Jeffrey D.; Hammarstrom, Jane M.; Zientek, Michael L.; Dicken, Connie L.; Drew, Lawrence J.; with contributions from Alexeiev, Dmitriy; Seltmann, Reimar; Herrington, Richard J.

2014-01-01

The U.S. Geological Survey conducted an assessment of resources associated with porphyry copper deposits in the western Central Asia countries of Kyrgyzstan, Uzbekistan, Kazakhstan, and Tajikistan and the southern Urals of Kazakhstan and Russia as part of a global mineral resource assessment. The purpose of the study was to (1) delineate permissive areas (tracts) for undiscovered porphyry copper deposits; (2) compile a database of known porphyry copper deposits and significant prospects; (3) where data permit, estimate numbers of undiscovered deposits within those permissive tracts; and (4) provide probabilistic estimates the amounts of copper (Cu), molybdenum (Mo), gold (Au), and silver (Ag) that could be contained in those undiscovered deposits.

Character, mass, distribution, and origin of tephra-fall deposits of the 1989-1990 eruption of redoubt volcano, south-central Alaska

Science.gov (United States)

Scott, W.E.; McGimsey, R.G.

1994-01-01

The 1989-1990 eruption of Redoubt Volcano spawned about 20 areally significant tephra-fall deposits between December 14, 1989 and April 26, 1990. Tephra plumes rose to altitudes of 7 to more than 10 km and were carried mainly northward and eastward by prevailing winds, where they substantially impacted air travel, commerce, and other activities. In comparison to notable eruptions of the recent past, the Redoubt events produced a modest amount of tephra-fall deposits - 6 ?? 107 to 5 ?? 1010 kg for individual events and a total volume (dense-rock equivalent) of about 3-5 ?? 107 m3 of andesite and dacite. Two contrasting tephra types were generated by these events. Pumiceous tephra-fall deposits of December 14 and 15 were followed on December 16 and all later events by fine-grained lithic-crystal tephra deposits, much of which fell as particle aggregates. The change in the character of the tephra-fall deposits reflects their fundamentally different modes of origin. The pumiceous deposits were produced by magmatically driven explosions. The finegrained lithic-crystal deposits were generated by two processes. Hydrovolcanic vent explosions generated tephrafall deposits of December 16 and 19. Such explosions continued as a tephra source, but apparently with diminishing importance, during events of January and February. Ash clouds of lithic pyroclastic flows generated by collapse of actively growing lava domes probably contributed to tephra-fall deposits of all events from January 2 to April 26, and were the sole source of tephra fall for at least the last 4 deposits. ?? 1994.

Biological mechanisms of gallium-67 tumor deposition

International Nuclear Information System (INIS)

Okuyama, Shinichi; Takeda, Shumpei; Sato, Tachio; Takusagawa, Kimihiko; Awano, Takayuki.

1979-01-01

This investigation was undertaken in order to clarify the tumor deposition mechanisms of 67 Ga citrate, a ''universal tumor labeler''. An interspecies comparison of various tumors in the rat and mouse indicated that its highest deposition was in the undifferentiated cell type. Amongst the siblings of experimental tumors, cellular membrane negative charge is greater in the free-cell types than the island-formers: a short-term labeling study revealed a greater 67 Ga deposition in the free-cell types. A subcellar fractionation showed an initial association of 67 Ga with the nuclear and membrane fractions, and a later transition to the lysosomal. Hypotonic lysis revealed a paralleled release of 67 Ga and lysosomal key enzymes. Morphological abnormality of the cancer lysosomes was thought to agree with their Ga retention. This property was clinically confirmed by a scintiscoring technique. Treatment with cold gallium of tumors modified the biological parameters of tumor growth: in vitro it suppressed cell proliferation, reduced saturation density; and produced cellular pleomorphism. In vivo it increased tumor consistency by reducing central necrosis and increasing the viable cell layer thickness. Thus, 67 Ga deposition is closely related to various biological parameters of malignancy including the cellular membrane negative charge as cancer is a membrane disorder, and the lysosomal morphology and function. (author)

Chronic nitrogen deposition influences the chemical dynamics ...

Science.gov (United States)

Atmospheric nitrogen deposition induces a forest carbon sink across broad parts of the Northern Hemisphere; this carbon sink may partly result from slower litter decomposition. Although microbial responses to experimental nitrogen deposition have been well-studied, evidence linking these microbial responses to changes in the degradation of specific compounds in decaying litter is sparse. We used wet chemistry and Fourier transform infrared spectroscopy (FTIR) methodologies to study the effects of chronic simulated nitrogen deposition on leaf litter and fine root chemistry during a three-year decomposition experiment at four northern hardwood forests in the north-central USA. Leaf litter and fine roots were highly different in initial chemistry such as concentrations of acid-insoluble fraction (AIF, or Klason lignin) and condensed tannins (CTs). These initial differences persisted over the course of decomposition. Results from gravimetrically-defined AIF and lignin/carbohydrate reference IR peak ratios both provide evidence that lignin in fine roots was selectively preserved under simulated nitrogen deposition. Lignin/carbohydrate peak ratios were strongly correlated with AIF, suggesting that AIF is a good predictor of lignin. Because AIF is abundant in fine roots, slower AIF degradation was the major driver of the slower fine root decomposition under nitrogen enrichment, explaining 73.9 % of the additional root mass retention. Nitrogen enrichment also slowed the

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

Feedback Control of Resistive Wall Modes in Slowly Rotating DIII-D Plasmas

Science.gov (United States)

Okabayashi, M.; Chance, M. S.; Takahashi, H.; Garofalo, A. M.; Reimerdes, H.; in, Y.; Chu, M. S.; Jackson, G. L.; La Haye, R. J.; Strait, E. J.

2006-10-01

In slowly rotating plasmas on DIII-D, the requirement of RWM control feedback have been identified, using a MHD code along with measured power supply characteristics. It was found that a small time delay is essential for achieving high beta if no rotation stabilization exists. The overall system delay or the band pass time constant should be in the range of 0.4 of the RWM growth time. Recently the control system was upgraded using twelve linear audio amplifiers and a faster digital control system, reducing the time-delay from 600 to 100 μs. The advantage has been clearly observed when the RWMs excited by ELMs were effectively controlled by feedback even if the rotation transiently slowed nearly to zero. This study provides insight on stability in the low- rotation plasmasw with balanced NBI in DIII-D and also in ITER.

Late post-irradiation phenomena in mammalian cell populations. Pt. 3. Characteristics of the slowly growing clones isolated from X-irradiated L5178Y-S cell cultures

International Nuclear Information System (INIS)

Beer, J.Z.; Szumiel, I.

1975-01-01

Populations of murine leukaemic lymphoblasts L5178Y-S irradiated with 300 rads of X-rays in vitro were analysed by serial clonings. It was found that the latent radiation-induced heritable lesions can be revealed by this technique. Approximately 100 slowly growing cell sublines with doubling times varying from 12 to 25 h, obtained by cloning, were assayed for: viability, cloning efficiency, mitotic index, labelling index (1 h and 24 h exposure to 3 H-thymidine), 3 H-thymidine incorporation rate, histone Fl phosphorous content, radiosensitivity, cell cycle disturbances, DNA per cell content, karyotype changes. The slowly-growing clones show normal or almost normal viability but have reduced cloning efficiencies. No correlations were found between the subline's doubling time or time interval between its isolation and determination, on one hand, and mitotic index or 1 h labelling index, on the other hand. 3 H-thymidine incorporation rate and histone Fl phosphorylation degree were inversely related to the subline's doubling time. Increased radiosensitivity of the slowly growing sublines, observed soon after their isolation, indicates that the heritable lesions in the cells studied are radiation-induced rather than selected. Autoradiographic analysis of the cell cycle indicates: heterogeneity of the slowly growing cell lines, occurence of cells with prolonged G2 phase and a possibility that in more severely damaged cells S phase is also affected. (author)

Long-range transport and deposition of sulfur in Asia

International Nuclear Information System (INIS)

Arndt, R.L.; Carmichael, G.R.

1995-01-01

The long range transport of sulfur in Asia is analyzed through the use of a multi-dimensional acid deposition model. The air quality of this region is heavily influenced by the combination of Asia's growing population, its expanding economy, and the associated systems of energy consumption and production. These factors combined with a shift to using indigenous coal as the primary fuel source for the region, will result in increased emissions of pollutants into the environment. By the year 2020 sulfur emissions from Asia are projected to exceed the combined emissions from Europe and North America. The authors have estimated sulfur deposition in Asia on a one-by-one degree spatial resolution in the region from Pakistan to Japan and from Indonesia to Mongolia using a 3-layer Lagrangian model. Deposition in excess of 10 g S/m 2 is predicted in south-central China. The relationship between emission source and receptor has been developed into a deposition matrix and examples of the source-receptor relationship are presented. 11 refs., 2 figs., 2 tabs

Sulfur impacts on forest health in west-central Alberta

International Nuclear Information System (INIS)

Maynard, D.G.; Stadt, J.J.; Mallett, K.I.; Volney, W.J.A.

1994-01-01

A study was conducted to evaluate forest health and tree growth in relation to sulfur deposition in mature and immature lodgepole pine and mature trembling aspen. Soil samples were taken in forests near two sour gas processing plants in west-central Alberta. The soil sample sites were classified into high, medium and low deposition classes. The impact of sulfur deposition on soil and foliar chemistry, tree growth, and forest health was evaluated. The analysis of tree growth, using radial increments, revealed no impact associated with the sulfur deposition class. The only indicators of extensive sulfur impacts on major forest communities detected to date are elevated sulfur concentrations in the surface organic horizon and foliage, the proportion of healthy lodgepole pines, and a depression in the annual specific volume increment. No evidence of widespread forest decline has been found. 42 refs., 35 tabs., 29 figs

Extended I-Love relations for slowly rotating neutron stars

Science.gov (United States)

Gagnon-Bischoff, Jérémie; Green, Stephen R.; Landry, Philippe; Ortiz, Néstor

2018-03-01

Observations of gravitational waves from inspiralling neutron star binaries—such as GW170817—can be used to constrain the nuclear equation of state by placing bounds on stellar tidal deformability. For slowly rotating neutron stars, the response to a weak quadrupolar tidal field is characterized by four internal-structure-dependent constants called "Love numbers." The tidal Love numbers k2el and k2mag measure the tides raised by the gravitoelectric and gravitomagnetic components of the applied field, and the rotational-tidal Love numbers fo and ko measure those raised by couplings between the applied field and the neutron star spin. In this work, we compute these four Love numbers for perfect fluid neutron stars with realistic equations of state. We discover (nearly) equation-of-state independent relations between the rotational-tidal Love numbers and the moment of inertia, thereby extending the scope of I-Love-Q universality. We find that similar relations hold among the tidal and rotational-tidal Love numbers. These relations extend the applications of I-Love universality in gravitational-wave astronomy. As our findings differ from those reported in the literature, we derive general formulas for the rotational-tidal Love numbers in post-Newtonian theory and confirm numerically that they agree with our general-relativistic computations in the weak-field limit.

Morphology and modern sedimentary deposits of the macrotidal Marapanim Estuary (Amazon, Brazil)

Science.gov (United States)

Araújo da Silva, Cléa; Souza-Filho, Pedro Walfir M.; Rodrigues, Suzan W. P.

2009-03-01

The northern Brazilian coast, east of the Amazon River is characterized by several macrotidal estuarine systems that harbor large mangrove areas with approximately 7600 km 2. The Marapanim Estuary is influenced by macrotidal regime with moderate waves influence. Morphologic units were investigated by using remote sensing images (i.e., Landsat-7 ETM+, RADARSAT- 1 Wide and SRTM) integrated with bathymetric data. The modern sedimentary deposits were analyzed from 67 cores collected by Vibracore and Rammkersonde systems. Analysis of morphology and surface sedimentary deposits of the Marapanim River reveal they are strongly influenced by the interaction of tidal, wave and fluvial currents. Based on these processes it was possible to recognize three distinct longitudinal facies zonation that revels the geological filling of a macrotidal estuary. The estuary mouth contain fine to medium marine sands strongly influenced by waves and tides, responsible for macrotidal sandy beaches and estuarine channel development, which are characterized by wave-ripple bedding and longitudinal cross-bedding sands. The estuary funnel is mainly influenced by tides that form wide tidal mudflats, colonized by mangroves, along the estuarine margin, with parallel laminations, lenticular bedding, root fragments and organic matter lenses. The upstream estuary contains coarse sand to gravel of fluvial origin. Massive mud with organic matter lenses, marks and roots fragments occur in the floodplain accumulates during seasonal flooding providing a slowly aggrading in the alluvial plain. This morphologic and depositional pattern show easily a tripartite zonation of a macrotidal estuary, that are in the final stage of filling.

Sediment deposition and trends and transport of phosphorus and other chemical constituents, Cheney Reservoir watershed, south-central Kansas

Science.gov (United States)

Mau, D.P.

2001-01-01

Sediment deposition, water-quality trends, and mass transport of phosphorus, nitrogen, selected trace elements, and selected pesticides within the Cheney Reservoir watershed in south-central Kansas were investigated using bathymetric survey data and reservoir bottom-sediment cores. Sediment loads in the reservoir were investigated by comparing 1964 topographic data to 1998 bathymetric survey data. Approximately 7,100 acre-feet of sediment deposition occurred in Cheney Reservoir from 1965 through 1998. As of 1998, sediment had filled 27 percent of the reservoir's inactive conservation storage pool, which is less than the design estimate of 34 percent. Mean annual sediment deposition was 209 acre-feet per year, or 0.22 acre-feet per year per square mile, and the mean annual sediment load was 453 million pounds per year. During the 3-year period from 1997 through 1999, 23 sediment cores were collected from the reservoir, and subsamples were analyzed for nutrients (phosphorus and nitrogen species), selected trace elements, and selected organic pesticides. Mean concentrations of total phosphorus in reservoir bottom sediment ranged from 94 milligrams per kilogram at the upstream end of the reservoir to 710 milligrams per kilogram farther downstream near the reservoir dam. The mean concentration for all sites was 480 milligrams per kilogram. Total phosphorus concentrations were greatest when more silt- and clay-sized particles were present. The implications are that if anoxic conditions (inadequate oxygen) occur near the dam, phosphorus could be released from the sediment and affect the drinking-water supply. Analysis of selected cores also indicates that total phosphorus concentrations in the reservoir sediment increased over time and were probably the result of nonpoint-source activities in the watershed, such as increased fertilizer use and livestock production. Mean annual phosphorus loading to Cheney Reservoir was estimated to be 226,000 pounds per year on the basis

Developing occupational chronologies for surface archaeological deposits from heat retainer hearths on Pine Point and Langwell stations, Far Western New South Wales, Australia

International Nuclear Information System (INIS)

Shiner, J.

2003-01-01

The archaeological record of arid Australia is dominated by deflated distributions of stone artefacts and heat retainer hearths covering many thousands of square metres. These deposits have often been over-looked by archaeologists in preference for stratified deposits, which are regarded as more appropriate for investigating temporal issues. In recent years this situation had slowly begun to change with the large-scale dating of heat retainer hearths from surface contexts. The work of of Fanning and Holdaway (2001) and Holdaway et al. (2002) in Far Western New South Wales has demonstrated that through the dating of large numbers of hearths it is possible to develop occupational chronologies for surface deposits. At a wider landscape scale these chronologies reflect the timing and tempo of the occupation of different places. A major component of my doctoral fieldwork on Pine Point and Langwell stations, 50 km south of Broken Hill in Western New South Wales, aimed to establish occupational chronologies from hearths for surface archaeological distributions. This paper reports on radiocarbon results from this investigation. (author). 6 refs., 2 figs., 1 tab

Particulate Matter deposition on Quercus ilex leaves in an industrial city of central Italy

Czech Academy of Sciences Publication Activity Database

Sgrigna, G.; Saebo, A.; Gawronski, S.; Popek, R.; Calfapietra, Carlo

2015-01-01

Roč. 197, FEB 2015 (2015), s. 187-194 ISSN 0269-7491 Institutional support: RVO:67179843 Keywords : PM10 * PM2.5 * Leaf deposition * Quercus ilex * urban environment * atmospheric pollution Subject RIV: EH - Ecology, Behaviour Impact factor: 4.839, year: 2015

Arid urban ecosystem not a hotspot for N deposition

Science.gov (United States)

Grimm, N. B.; Cook, E. M.; Hall, S. J.; Wheeler, M.

2017-12-01

Urban areas are omitted in most long-term data collection for nitrogen deposition in the United States. Nitrogen sources in and surrounding cities are notoriously variable in space and time. In the desert Southwest, cities are distinct and isolated from one another, deposition is dominated by dryfall, and rainfall is spatially and temporally heterogeneous. These conditions present a challenge for understanding the overall rate, spatial pattern, and fate of nitrogen deposition in urbanized aridlands. We quantified long-term spatial and temporal patterns of inorganic nitrogen deposition in protected aridland ecosystems across an extensive urban-rural gradient in central Arizona, using multiple sampling methods. Furthermore, we assessed the impact of nitrogen deposition along the same gradient on winter annual plant growth and community structure, as an integrative indicator of the fate and impact of nitrogen deposition. Best estimates of nitrogen deposition, based on ion-exchange resin collectors, wet-dry bucket collectors, and inferential estimates of dryfall using passive samplers, were 7.2 ± 0.4 kg N ha-1 y-1 within city boundaries and 6.1 ± 0.3 kg N ha-1 y-1 in nearby desert lands. Although the data indicate the city may not be a hotspot of nitrogen deposition, species diversity of annual plants in urban desert remnant parks is reduced in a manner similar to diversity losses associated with experimental nitrogen fertilization. Thus, reduced species diversity is a possible consequence of locally elevated nitrogen deposition within the city. The long-term mean urban deposition rate estimated with mixed methods is substantially lower than that predicted by regional models and by estimated inorganic nitrogen fixation from automobile and other combustion sources. This discrepancy raises a question about the fate of this excess nitrogen in the larger aridland region.

Insights into mercury deposition and spatiotemporal variation in the glacier and melt water from the central Tibetan Plateau.

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Paudyal, Rukumesh; Kang, Shichang; Huang, Jie; Tripathee, Lekhendra; Zhang, Qianggong; Li, Xiaofei; Guo, Junming; Sun, Shiwei; He, Xiaobo; Sillanpää, Mika

2017-12-01

Long-term monitoring of global pollutant such as Mercury (Hg) in the cryosphere is very essential for understanding its bio-geochemical cycling and impacts in the pristine environment with limited emission sources. Therefore, from May 2015 to Oct 2015, surface snow and snow-pits from Xiao Dongkemadi Glacier and glacier melt water were sampled along an elevation transect from 5410 to 5678m a.s.l. in the central Tibetan Plateau (TP). The concentration of Hg in surface snow was observed to be higher than that from other parts of the TP. Unlike the southern parts of the TP, no clear altitudinal variation was observed in the central TP. The peak Total Hg (Hg T ) concentration over the vertical profile on the snow pits corresponded with a distinct yellowish-brown dust layer supporting the fact that most of the Hg was associated with particulate matter. It was observed that only 34% of Hg in snow was lost when the surface snow was exposed to sunlight indicating that the surface snow is less influenced by the post-depositional process. Significant diurnal variation of Hg T concentration was observed in the river water, with highest concentration observed at 7pm when the discharge was highest and lowest concentration during 7-8am when the discharge was lowest. Such results suggest that the rate of discharge was influential in the concentration of Hg T in the glacier fed rivers of the TP. The estimated export of Hg T from Dongkemadi river basin is 747.43gyr -1 , which is quite high compared to other glaciers in the TP. Therefore, the export of global contaminant Hg might play enhanced role in the Alpine regions as these glaciers are retreating at an alarming rate under global warming which may have adverse impact on the ecosystem and the human health of the region. Copyright © 2017 Elsevier B.V. All rights reserved.

Problems related to the determination of mass densities of evaporated reference deposits

Science.gov (United States)

Tagziria, H.; Pauwels, J.; Verdonk, J.; Van Gestel, J.; Eykens, R.; Gilliam, D. M.; Scott, R. D.; Byrne, J.; Dawber, P.

1991-05-01

The accurate characterization of the surface density (nuclei/cm 2) of thin isotopic deposits is of highest importance in certain experiments. If accuracies better than ± 0.5% are to be quoted, careful consideration of seemingly minor effects is necessary, as these effects may generate serious errors. The radial surface density distribution in the central region of the target disks, the thickness profile at the edges, and the evaluation of effective deposit diameters are discussed for the case of measurements and observations made during the preparation and characterization of 6LiF and 10B reference deposits, which were employed in a recent determination of the free neutron lifetime. Theoretical calculations are in excellent agreement with the experimental results.

SOME INOZOID SPONGES FROM UPPER TRIASSIC (NORIAN-RHAETIAN NAYBAND FORMATION OF CENTRAL IRAN

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BABA SENOWBARI-DARYAN

1997-11-01

Full Text Available Some small-scaled Norian-Rhaetian reefs and reef mounds are imbedded within the shales, siltstones and siliciclastic-carbonate deposits of the Nayband Formation in central Iran. These deposits belong to the central Iranian plate as part of the Cimmerian Continent. Most of the biogenic rocks have a biostromal geometry, biohermal constructions are rare. Inozoid, sphinctozoid, and chaetetid sponges are, beside of corals and other reef builders, the most important reef organisms within these bioconstructions. In some reefs a variety of hexactinellid sponges also occur. The following inozoid sponges are described in this paper: Radiofibra norica n. sp., Permocorynella maxima n. sp., ?Sestrostomella robusta, Marawandia iranica, n. gen., n. sp. and Enaulofungia? triassica n. sp. The first four taxa are among the most abundant sponges within the Nayband Formation where it is exposed in several localities in central Iran. Enaulofungia? triassica, however, is not an abundant sponge there. These inozoid sponges have never been reported from the Triassic deposits of this region. Radiofibra, until now known only from the Upper Permian of Djebel Tebaga (Tunisia, is reported here for the first time from Triassic rocks. The stratigraphic as well as the paleogeographic distribution of all the genera are discussed.   

Comparison of snowpack and winter wet-deposition chemistry in the Rocky Mountains, USA: implications for winter dry deposition

Science.gov (United States)

Clow, David W.; Ingersoll, George P.; Mast, M. Alisa; Turk, John T.; Campbell, Donald H.

Depth-integrated snowpack chemistry was measured just prior to maximum snowpack depth during the winters of 1992-1999 at 12 sites co-located with National Atmospheric Deposition Program/National Trend Network (NADP/NTN) sites in the central and southern Rocky Mountains, USA. Winter volume-weighted mean wet-deposition concentrations were calculated for the NADP/NTN sites, and the data were compared to snowpack concentrations using the paired t-test and the Wilcoxon signed-rank test. No statistically significant differences were indicated in concentrations of SO 42- or NO 3- ( p>0.1). Small, but statistically significant differences ( p⩽0.03) were indicated for all other solutes analyzed. Differences were largest for Ca 2+ concentrations, which on average were 2.3 μeq l -1 (43%) higher in the snowpack than in winter NADP/NTN samples. Eolian carbonate dust appeared to influence snowpack chemistry through both wet and dry deposition, and the effect increased from north to south. Dry deposition of eolian carbonates was estimated to have neutralized an average of 6.9 μeq l -1 and a maximum of 12 μeq l -1 of snowpack acidity at the southernmost sites. The good agreement between snowpack and winter NADP/NTN SO 42- and NO 3- concentrations indicates that for those solutes the two data sets can be combined to increase data density in high-elevation areas, where few NADP/NTN sites exist. This combination of data sets will allow for better estimates of atmospheric deposition of SO 42- and NO 3- across the Rocky Mountain region.

Role of DNA repair in repair of cytogenetic damages. Slowly repaired DNA injuries involved in cytogenetic damages repair

International Nuclear Information System (INIS)

Zaichkina, S.I.; Rozanova, O.M.; Aptikaev, G.F.; Ganassi, E.Eh.

1989-01-01

Caffeine was used to study the kinetics of cytogenetic damages repair in Chinese hamster fibroblasts. Its half-time (90 min) was shown to correlate with that of repair of slowly repaired DNA damages. The caffeine-induced increase in the number of irreparable DNA damages, attributed to inhibition of double-strand break repair, is in a quantitative correlation with the effect of the cytogenetic damage modification

Growing massive black holes in a Local Group environment: the central supermassive, slowly sinking and ejected populations

Science.gov (United States)

Micic, Miroslav; Holley-Bockelmann, Kelly; Sigurdsson, Steinn

2011-06-01

We explore the growth of ≤107 M⊙ black holes that reside at the centres of spiral and field dwarf galaxies in a Local Group type of environment. We use merger trees from a cosmological N-body simulation known as Via Lactea 2 (VL-2) as a framework to test two merger-driven semi-analytic recipes for black hole growth that include dynamical friction, tidal stripping and gravitational wave recoil in over 20 000 merger tree realizations. First, we apply a Fundamental Plane limited (FPL) model to the growth of Sgr A*, which drives the central black hole to a maximum mass limited by the black hole Fundamental Plane after every merger. Next, we present a new model that allows for low-level prolonged gas accretion (PGA) during the merger. We find that both models can generate an Sgr A* mass black hole. We predict a population of massive black holes in local field dwarf galaxies - if the VL-2 simulation is representative of the growth of the Local Group, we predict up to 35 massive black holes (≤106 M⊙) in Local Group field dwarfs. We also predict that hundreds of ≤105 M⊙ black holes fail to merge, and instead populate the Milky Way halo, with the most massive of them at roughly the virial radius. In addition, we find that there may be hundreds of massive black holes ejected from their hosts into the nearby intergalactic medium due to gravitational wave recoil. We discuss how the black hole population in the Local Group field dwarfs may help to constrain the growth mechanism for Sgr A*.

Deposition and clearance of inhaled 18FDG powder in patients with chronic obstructive pulmonary disease

International Nuclear Information System (INIS)

Yanai, M.; Sasaki, H.; Hatazawa, J.; Ojima, F.; Itoh, M.; Ido, T.

1998-01-01

As freon is limited in its use as a generator for aerosol inhalation, powder particles are used as an alternative for inhalation therapy. The pulmonary deposition and clearance of inhaled powder particles was studied by positron emission tomography (PET) in ten patients with chronic obstructive pulmonary disease (COPD) and in five normal controls. The powder, 5 μm in mean diameter, was water soluble and labelled with 2-deoxy-2[ 18 F]-fluoro-D-glucose ( 18 FDG). Powder inhalation was done with single deep inspiration from residual volume to total lung capacity. The initial deposition ratio in the right or left lung field to total inhaled dose, measured by an anteroposterior rectilinear scan, did not differ between normal and COPD patients. Ratios of radioactivity detected within the central and peripheral regions (the central to peripheral ratio) measured by the PET scan was not significantly different between COPD patients (4.8±2.6, mean±SD) and normals (2.6±0.8, mean±SD). However, the regional powder deposition in peripheral lung fields measured by the PET scan was significantly more uneven in COPD patients than in normal patients. The clearance rate of 18 FDG, defined as the retention ratio of 18 FDG activity to the initially deposited 18 FDG at 60 and 120 min after inhalation, in the trachea, large bronchi or peripheral lung fields measured by tomographic scan showed a wider variation in COPD patients than in normals. To conclude, inhaled powder tended to be deposited more centrally and was distributed more unevenly in the peripheral lung in chronic obstructive pulmonary disease patients than in normals. This could be a limitation of powder inhalation used for therapy in chronic obstructive pulmonary disease patients. (au)

Uranium in early proterozoic phosphate-rich metasedimentary rocks of east-central Minnesota

International Nuclear Information System (INIS)

McSwiggen, P.L.; Morey, G.B.; Weiblen, P.W.

1986-01-01

Exploration for unconformity-type uranium deposits in the late 1970s in east-central Minnesota led to the discovery of several uranium-bearing phosphorite occurrences in rocks of early Proterozoic age. In this report the authors use the term phosphorite for a rock or specimen that contains substantial sedimentary apatite (Altschuler et al., 1958). The deposits in Minnesota are especially interesting because of their high uranium content but low metamorphic grade. These occurrences characteristically contain 0.025 to 0.085 percent U and locally as much as 0.157 percent U (Ullmer, 1981), whereas typical primary marine phosphorites have uranium contents of 0.005 to 0.02 percent U (Altschuler et al., 1958). The presence of uranium in a marine phosphorite generally is explained by either the replacement of calcium in the apatite crystal structure or the adsorption of uranium in admixed organic matter and cryptocrystalline apatite. In east-central Minnesota the uranium is closely associated with the finely crystalline apatite, but the uranium has also been involved in several episodes of remobilization and redeposition. Thus, even though the phosphorite deposits are an interesting geologic phenomenon in themselves, they also are important as a possible source for epigenetic uranium deposits that may occur in the area

The scid mutation does not affect slowly repairing potentially lethal damage that is sensitive to 0.23 M NaCl

International Nuclear Information System (INIS)

Kimura, Hiroshi; Ikebuchi, Makoto; Fushiki, Masato; Komatsu, Kenshi.

1996-01-01

The repair of slowly repairing potentially lethal damage (PLD) in radiosensitive cells from the severe combined immunodeficient (scid) mouse was compared with that in Balb/c 3T3 cells with ''wild-type'' radiosensitivity and that in RD13B2 cells derived from scid cells whose sensitivity is normal because of the presence of fragments of human chromosome 8. Treatment with 0.23 M NaCl was used for fixation of slowly repairing PLD. The scid cells repaired PLD sensitive to 0.23 M NaCl to a great extent whin 3-4 h, similarly to Balb/c 3T3 and RD13B2 cells. This indicates that the scid mutation hardly affects the repair of PLD sensitive to 0.23 M NaCl. On the other hand, as reported previously, the rapidly repairing PLD that is sensitive to 0.5 M NaCl was repaired only slowly (3-4 h) in scid cells, in contrast to the rapid repair (within 1 h) seen with Balb/c 3T3 and RD13B2. This suggests that scid mutation is responsible for this repair at reduced rate. To confirm the independence of repair of 0.23 M NaCl-sensitive PLD from that of 0.5 M NaCl-sensitive PLD, both treatments with 0.23 M NaCl and 0.5 M NaCl were combined in each line. It is found that the repair of either PLD was not affected by the other treatment. The scid mutation impaired only the repair of 0.5 M NaCl-sensitive PLD. (author)

Paleozoic–early Mesozoic gold deposits of the Xinjiang Autonomous Region, northwestern China

Science.gov (United States)

Rui, Zongyao; Goldfarb, Richard J.; Qiu, Yumin; Zhou, T.; Chen, R.; Pirajno, Franco; Yun, Grace

2002-01-01

The late Paleozoic–early Mesozoic tectonic evolution of Xinjiang Autonomous Region, northwestern China provided a favorable geological setting for the formation of lode gold deposits along the sutures between a number of the major Eastern Asia cratonic blocks. These sutures are now represented by the Altay Shan, Tian Shan, and Kunlun Shan ranges, with the former two separated by the Junggar basin and the latter two by the immense Tarim basin. In northernmost Xinjiang, final growth of the Altaid orogen, southward from the Angara craton, is now recorded in the remote mid- to late Paleozoic Altay Shan. Accreted Early to Middle Devonian oceanic rock sequences contain typically small, precious-metal bearing Fe–Cu–Zn VMS deposits (e.g. Ashele). Orogenic gold deposits are widespread along the major Irtysh (e.g. Duyolanasayi, Saidi, Taerde, Kabenbulake, Akexike, Shaerbulake) and Tuergen–Hongshanzui (e.g. Hongshanzui) fault systems, as well as in structurally displaced terrane slivers of the western Junggar (e.g. Hatu) and eastern Junggar areas. Geological and geochronological constraints indicate a generally Late Carboniferous to Early Permian episode of gold deposition, which was coeval with the final stages of Altaid magmatism and large-scale, right-lateral translation along older terrane-bounding faults. The Tian Shan, an exceptionally gold-rich mountain range to the west in the Central Asian republics, is only beginning to be recognized for its gold potential in Xinjiang. In this easternmost part to the range, northerly- and southerly-directed subduction/accretion of early to mid-Paleozoic and mid- to late Paleozoic oceanic terranes, respectively, to the Precambrian Yili block (central Tian Shan) was associated with 400 to 250 Ma arc magmatism and Carboniferous through Early Permian gold-forming hydrothermal events. The more significant resulting deposits in the terranes of the southern Tian Shan include the Sawayaerdun orogenic deposit along the Kyrgyzstan

Gaseous Oxidized Mercury Dry Deposition Measurements in the Southwestern USA: A Comparison between Texas, Eastern Oklahoma, and the Four Corners Area

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Mark E. Sather

2014-01-01

Full Text Available Gaseous oxidized mercury (GOM dry deposition measurements using aerodynamic surrogate surface passive samplers were collected in central and eastern Texas and eastern Oklahoma, from September 2011 to September 2012. The purpose of this study was to provide an initial characterization of the magnitude and spatial extent of ambient GOM dry deposition in central and eastern Texas for a 12-month period which contained statistically average annual results for precipitation totals, temperature, and wind speed. The research objective was to investigate GOM dry deposition in areas of Texas impacted by emissions from coal-fired utility boilers and compare it with GOM dry deposition measurements previously observed in eastern Oklahoma and the Four Corners area. Annual GOM dry deposition rate estimates were relatively low in Texas, ranging from 0.1 to 0.3 ng/m2h at the four Texas monitoring sites, similar to the 0.2 ng/m2h annual GOM dry deposition rate estimate recorded at the eastern Oklahoma monitoring site. The Texas and eastern Oklahoma annual GOM dry deposition rate estimates were at least four times lower than the highest annual GOM dry deposition rate estimate previously measured in the more arid bordering western states of New Mexico and Colorado in the Four Corners area.

Stratigraphy and palaeoclimatic significance of Late Quaternary loess-palaeosol sequences of the Last Interglacial-Glacial cycle in central Alaska

Science.gov (United States)

Muhs, D.R.; Ager, T.A.; Bettis, E. Arthur; McGeehin, J.; Been, J.M.; Beget, J.E.; Pavich, M.J.; Stafford, Thomas W.; Stevens, D.A.S.P.

2003-01-01

Loess is one of the most widespread subaerial deposits in Alaska and adjacent Yukon Territory and may have a history that goes back 3 Ma. Based on mineralogy and major and trace element chemistry, central Alaskan loess has a composition that is distinctive from other loess bodies of the world, although it is quartz-dominated. Central Alaskan loess was probably derived from a variety of rock types, including granites, metabasalts and schists. Detailed stratigraphic data and pedologic criteria indicate that, contrary to early studies, many palaeosols are present in central Alaskan loess sections. The buried soils indicate that loess sedimentation was episodic, or at least rates of deposition decreased to the point where pedogenesis could keep ahead of aeolian input. As in China, loess deposition and pedogenesis are likely competing processes and neither stops completely during either phase of the loess/soil formation cycle. Loess deposition in central Alaska took place before, and probably during the last interglacial period, during stadials of the mid-Wisconsin period, during the last glacial period and during the Holocene. An unexpected result of our geochronological studies is that only moderate loess deposition took place during the last glacial period. Our studies lead us to conclude that vegetation plays a key role in loess accumulation in Alaska. Factors favouring loess production are enhanced during glacial periods but factors that favour loess accumulation are diminished during glacial periods. The most important of these is vegetation; boreal forest serves as an effective loess trap, but sparsely distributed herb tundra does not. Thus, thick accumulations of loess should not be expected where tundra vegetation was dominant and this is borne out by modern studies near the treeline in central Alaska. Much of the stratigraphic diversity of North American loess, including that found in the Central Lowlands, the Great Plains, and Alaska is explained by a new

Rubidium-strontium isotoppe study of Muruntan deposit. 1.Ore vien dating by isochrone technique

International Nuclear Information System (INIS)

Kostitsyn, Yu.A.

1993-01-01

Hydrothermal viens of Muruntau gold-ore deposit (Central Kyzylkum) have been studies by the isochrone technique. The ages obtained for the quartz-tourmaline (257+13 Ma), quartz-arsenopyrite (230.3+-3.5 Ma) and quartz-adularia (219.4+-4.2 Ma) hydrothermal viens reflect the different stages of the deposit evolution: gold-ore and gold-silver one. Strontium isotope analysis reveals that the matter of hydrothermal viens is originated from the surrounding black schists

Alunite in the Pascua-Lama high-sulfidation deposit: Constraints on alteration and ore deposition using stable isotope geochemistry

Science.gov (United States)

Deyell, C.L.; Leonardson, R.; Rye, R.O.; Thompson, J.F.H.; Bissig, T.; Cooke, D.R.

2005-01-01

The Pascua-Lama high-sulfidation system, located in the El Indio-Pascua belt of Chile and Argentina, contains over 16 million ounces (Moz) Au and 585 Moz Ag. The deposit is hosted primarily in granite rocks of Triassic age with mineralization occurring in several discrete Miocene-age phreatomagmatic breccias and related fracture networks. The largest of these areas is Brecha Central, which is dominated by a mineralizing assemblage of alunite-pyrite-enargite and precious metals. Several stages of hydrothermal alteration related to mineralization are recognized, including all types of alunite-bearing advanced argillic assemblages (magmatic-hydrothermal, steam-heated, magmatic steam, and supergene). The occurrence of alunite throughout the paragenesis of this epithermal system is unusual and detailed radiometric, mineralogical, and stable isotope studies provide constraints on the timing and nature of alteration and mineralization of the alunite-pyiite-enargite assemblage in the deposit. Early (preore) alteration occurred prior to ca. 9 Ma and consists of intense silicic and advanced argillic assemblages with peripheral argillic and widespread propylitic zones. Alunite of this stage occurs as fine intergrowths of alunite-quartz ?? kaolinite, dickite, and pyrophyllite that selectively replaced feldspars in the host rock. Stable isotope systematics suggest a magmatic-hydrothermal origin with a dominantly magmatic fluid source. Alunite is coeval with the main stage of Au-Ag-Cu mineralization (alunite-pyrite-enargite assemblage ore), which has been dated at approximately 8.8 Ma. Ore-stage alunite has an isotopic signature similar to preore alunite, and ?? 34Salun-py data indicate depositional temperatures of 245?? to 305??C. The ??D and ?? 18O data exclude significant involvement of meteoric water during mineralization and indicate that the assemblage formed from H2S-dominated magmatic fluids. Thick steam-heated alteration zones are preserved at the highest elevations in

Monte Carlo study of radial energy deposition from primary and secondary particles for narrow and large proton beamlet source models

International Nuclear Information System (INIS)

Peeler, Christopher R; Titt, Uwe

2012-01-01

In spot-scanning intensity-modulated proton therapy, numerous unmodulated proton beam spots are delivered over a target volume to produce a prescribed dose distribution. To accurately model field size-dependent output factors for beam spots, the energy deposition at positions radial to the central axis of the beam must be characterized. In this study, we determined the difference in the central axis dose for spot-scanned fields that results from secondary particle doses by investigating energy deposition radial to the proton beam central axis resulting from primary protons and secondary particles for mathematical point source and distributed source models. The largest difference in the central axis dose from secondary particles resulting from the use of a mathematical point source and a distributed source model was approximately 0.43%. Thus, we conclude that the central axis dose for a spot-scanned field is effectively independent of the source model used to calculate the secondary particle dose. (paper)

Sedimentary processes in the Carnot Formation (Central African Republic) related to the palaeogeographic framework of Central Africa

Science.gov (United States)

Censier, Claude; Lang, Jacques

1999-08-01

The depositional environment, provenance and processes of emplacement of the detrital material of the Mesozoic Carnot Formation are defined, by bedding and sedimentological analysis of its main facies, and are reconstructed within the palaeogeographic framework of Central Africa. The clastic material was laid down between probably the Albian and the end of the Cretaceous, in a NNW-oriented braided stream fluvial system that drained into the Doba Trough (Chad) and probably also into the Touboro Basin (Cameroon). The material was derived from weathering of the underlying Devonian-Carboniferous Mambéré Glacial Formation and of the Precambrian schist-quartzite complex located to the south of the Carnot Formation. These results provide useful indications as to the provenance of diamonds mined in the southwest Central African Republic.

Characteristics of debris avalanche deposits inferred from source volume estimate and hummock morphology around Mt. Erciyes, central Turkey

Science.gov (United States)

Hayakawa, Yuichi S.; Yoshida, Hidetsugu; Obanawa, Hiroyuki; Naruhashi, Ryutaro; Okumura, Koji; Zaiki, Masumi; Kontani, Ryoichi

2018-02-01

Debris avalanches caused by volcano sector collapse often form characteristic depositional landforms such as hummocks. Sedimentological and geomorphological analyses of debris avalanche deposits (DADs) are crucial to clarify the size, mechanisms, and emplacement of debris avalanches. We describe the morphology of hummocks on the northeastern flank of Mt. Erciyes in Kayseri, central Turkey, likely formed in the late Pleistocene. Using a remotely piloted aircraft system (RPAS) and the structure-from-motion and multi-view stereo (SfM-MVS) photogrammetry, we obtained high-definition digital elevation model (DEM) and orthorectified images of the hummocks to investigate their geometric features. We estimated the source volume of the DAD by reconstructing the topography of the volcano edifice using a satellite-based DEM. We examined the topographic cross sections based on the slopes around the scar regarded as remnant topography. Spatial distribution of hummocks is anomalously concentrated at a certain distance from the source, unlike those that follow the distance-size relationship. The high-definition land surface data by RPAS and SfM revealed that many of the hummocks are aligned toward the flow direction of the debris avalanche, suggesting that the extensional regime of the debris avalanche was dominant. However, some displaced hummocks were also found, indicating that the compressional regime of the flow contributed to the formation of hummocks. These indicate that the flow and emplacement of the avalanche were constrained by the topography. The existing caldera wall forced the initial eastward flow to move northward, and the north-side caldera wall forced the flow into the narrow and steepened outlet valley where the sliding debris underwent a compressional regime, and out into the unconfined terrain where the debris was most likely emplaced on an extensional regime. Also, the estimated volume of 12-15 × 108 m3 gives a mean thickness of 60-75 m, which is much

Aeolian dust supply from the Yellow River floodplain to the Pleistocene loess deposits of the Mangshan Plateau, central China: Evidence from zircon U-Pb age spectra

Science.gov (United States)

Shang, Yuan; Prins, Maarten A.; Beets, Christiaan J.; Kaakinen, Anu; Lahaye, Yann; Dijkstra, Noortje; Rits, Daniël S.; Wang, Bin; Zheng, Hongbo; van Balen, Ronald T.

2018-02-01

The thick loess-palaeosol sequences in the Mangshan Loess Plateau (MLP; central China) along the south bank of the lower reach of the Yellow River provide high-resolution records of Quaternary climate change. In addition, substantial increases in grain-size and accumulation rate have been inferred in the upper part of the loess sequence, above palaeosol layer S2. This study investigates the sources of the long-term dust supply to the MLP and explores the mechanism behind the sudden increase in sediment delivery and coarsening of the loess deposits since S2 (∼240 ka) by using end member modelling of the loess grain-size dataset and single-grain zircon U-Pb dating. Our results indicate that the lower Yellow River floodplain, directly north of the MLP, served as a major dust supply for the plateau at least since the deposition of loess unit L9 and indirectly suggest that the integration of the Yellow River and the disappearance of the Sanmen palaeolake took place before L9 (∼900 ka). The sudden change in sedimentology of the Mangshan sequence above palaeosol unit S2 may result from an increased fluvial sediment flux being transported to the lower reaches of the Yellow River because of tectonic movements (initiated) in the Weihe Basin around 240 ka. Furthermore, sediment coarsening can be explained by the gradual southward migration of the lower Yellow River floodplain towards the MLP since the deposition of palaeosol S2. The migration is evidenced by the formation of an impressive scarp, and is likely caused by tectonic tilting of the floodplain area.

Constraining Holocene Evolution of Shelf Bayhead Delta Deposits Offshore Mississippi, USA

Science.gov (United States)

Hollis, R. J.; Wallace, D. J.; Miner, M. D.

2017-12-01

The slowly subsiding inner shelf of Mississippi-Alabama (MS-AL) has a complex network of Late Quaternary paleofluvial and deltaic deposits driven by fluctuating sea levels. Since the Last Glacial Maximum, sea-level rise (SLR) has lead to transgressive reworking of these lithosomes. In rare instances, typically when the rate of relative sea-level rise was particularly rapid or sediment supply was high, these deposits are preserved. Results from studies in Texas and Alabama suggest bayhead deltas (or upper-estuarine units) backstepped kilometers landward in response to periods of rapid sea-level rise (i.e. 9.8-9.5 ka, 8.9-8.5 ka, 8.4-8.0 ka, 7.9-7.5 ka, and 7.4-6.8 ka). Bayhead delta backstepping depends on relative SLR rates, accommodation space, shelf slope, wave climate and sediment supply. While at least one preserved bayhead delta deposit has been identified on the inner shelf of MS-AL, the flooding and abandonment chronology is currently unknown. The previously quantified sandy bayhead delta deposit (>100.4 x106 m3) is roughly twice the combined volume of the subaerial Petit Bois barrier island, located two miles to the north, and the three western offshore shelf sand shoals (55.9 x106 m3). The sediment supply needed for the shoal's genesis requires further exploration and likely has many contributors, but transgressive ravinement of the sandy bayhead delta seems like a logical source. This study builds on previous work that has extensively mapped the stratigraphy of the eastern MS-AL inner shelf using geophysical and core data by adding a robust number of radiocarbon ages and macro-/micro- faunal analysis from new cores as a proxy for depositional environments. This source-to-sink approach helps to detail the evolution of ancient Pascagoula/Escatawpa, La Batre and Fowl paleo rivers, and their roles in the formation of the large inner shelf, shore-oblique shoals as well as Petit Bois Island. Correlating the new ages with previously published high-resolution sea

Type of delta cycle in the Upper Westphalian of the Central coalfield (Spain)

Energy Technology Data Exchange (ETDEWEB)

Colmenero, J R; Barba Regidor, P

1985-01-01

The deltas were one of the main depositional systems in Westphalian sedimentation of the Central Asturian Coalfield. A prograding shallow fluvial dominated deltaic cycle is analyzed in this paper. The prograding coarsening-upward sequence consists mainly of sandstone lithofacies deposited by small-scale distributary fluvial channels and bars. Several widely distributed bituminous coal seams in the delta-plain lithofacies reflect inactive stages without sedimentation before its definitive abandonment.

Decoherence approach to energy transfer and work done by slowly driven systems

Science.gov (United States)

Wang, Wen-ge

2018-01-01

A main problem, which is met when computing the energy transfer of or work done by a quantum system, comes from the fact that the system may lie in states with coherence in its energy eigenstates. As is well known, when the so-called environment-induced decoherence has happened with respect to a preferred basis given by the energy basis, no coherence exists among the energy basis and the energy change of the system can be computed in a definite way. I argue that one may make use of this property, in the search for an appropriate definition of quantum work for a total system that does not include any measuring apparatus. To show how this idea may work, in this paper, I study decoherence properties of a generic slowly driven system, which is weakly coupled to a huge environment whose main body is a complex quantum system. It is shown that decoherence may generically happen for such a system.

One-dimensional free-electron laser equations without the slowly varying envelope approximation

Directory of Open Access Journals (Sweden)

C. Maroli

2011-07-01

Full Text Available A set of one-dimensional equations has been deduced in the time domain from the Maxwell-Lorentz system with the aim of describing the free-electron laser radiation without using the slowly varying envelope approximation (SVEA. These equations are valid even in the case of arbitrarily short electron bunches and of current distributions with ripples on the scale of or shorter than the wavelength. Numerical examples are presented, showing that for long homogeneous bunches the new set of equations gives results in agreement with the SVEA free-electron laser theory and that the use of short or prebunched electron beams leads to a decrease of the emission lethargy. Furthermore, we demonstrate that in all cases in which the backward low frequency wave has negligible effects, these equations can be reduced to a form similar to the usual 1D SVEA equations but with a different definition of the bunching term.

Problems related to the determination of mass densities of evaporated reference deposits

International Nuclear Information System (INIS)

Tagziria, H.; Pauwels, J.; Verdonk, J.; Gestel, J. van; Eykens, R.; Gilliam, D.M.; Scott, R.D.; Byrne, J.; Dawber, P.

1991-01-01

The accurate characterization of the surface density (nuclei/cm 2 ) of thin isotopic deposits is of highest importance in certain experiments. If accuracies better than ±0.5% are to be quoted, careful consideration of seemingly minor effects is necessary, as these effects may generate serious errors. The radial surface density distribution in the central region of the target disks, the thickness profile at the edges, and the evaluation of effective deposit diameters are discussed for the case of measurements and observations made during the preparation and characterization of 6 LiF and 10 B reference deposits, which were employed in a recent determination of the free neutron lifetime. Theoretical calculations are in excellent agreement with the experimental results. (orig.)

Problems related to the determination of mass densities of evaporated reference deposits

Energy Technology Data Exchange (ETDEWEB)

Tagziria, H.; Pauwels, J.; Verdonk, J.; Gestel, J. van; Eykens, R. (Commission of the European Communities, Joint Research Centre, Central Bureau for Nuclear Measurements, Geel (Belgium)); Gilliam, D.M. (National Inst. of Standards and Tech., Gaithersburg, MD (USA)); Scott, R.D. (Scottish Universities Research and Reactor Centre, Glasgow (UK)); Byrne, J.; Dawber, P. (School of Mathematical and Physical Sciences, Univ. of Sussex, Brighton (UK))

1991-05-15

The accurate characterization of the surface density (nuclei/cm{sup 2}) of thin isotopic deposits is of highest importance in certain experiments. If accuracies better than {+-}0.5% are to be quoted, careful consideration of seemingly minor effects is necessary, as these effects may generate serious errors. The radial surface density distribution in the central region of the target disks, the thickness profile at the edges, and the evaluation of effective deposit diameters are discussed for the case of measurements and observations made during the preparation and characterization of {sup 6}LiF and {sup 10}B reference deposits, which were employed in a recent determination of the free neutron lifetime. Theoretical calculations are in excellent agreement with the experimental results. (orig.).

Magnetic, radiometric and gravity signatures of localities of epithermal gold deposits in Fiji

International Nuclear Information System (INIS)

Gunn, Peter J.; Mackey, Tim; Meixner, Tony J.

1998-01-01

Fiji contains several epithermal gold deposits and by studying the geophysical responses in the vicinity of these deposits it is possible to identify a set of geophysical characteristics which indicate localities where such deposits may be located. Epithermal gold deposits are formed above intrusive stocks resulting from subduction processes. The source intrusions for the deposits are normally covered by lavas and pyroclastic rocks and the irregular magnetic effects of these units obscure the magnetic effects of the intrusions. In Fiji however the source intrusions can be recognized as causing gravity highs and magnetic highs in upward continued magnetic data in which the magnetic effects of volcanic rocks are suppressed. Vents associated with the intrusions can be recognized as magnetic lows which sometimes contain a central high. Some vents and calderas can be recognized in digital elevation data. Increased potassium concentrations ca be interpreted to indicate potassium alteration associated with mineralizing processes. Fractures that may localize epithermal deposits can be recognized in the magnetic data and enhancements of the data such as produced by derivative operations. (author)

Uplift sequence of the Andes at 30°S: Insights from sedimentology and U/Pb dating of synorogenic deposits

Science.gov (United States)

Suriano, J.; Mardonez, D.; Mahoney, J. B.; Mescua, J. F.; Giambiagi, L. B.; Kimbrough, D.; Lossada, A.

2017-04-01

The South Central Andes at 30°S represent a key area to understand the Andes geodynamics as it is in the middle of the flat slab segment and all the morphotectonic units of the Central Andes are well developed. This work is focused in the proximal synorogenic deposits of the Western Precordillera, in the La Tranca valley, in order to unravel the uplift sequence of this belt. Nine facies associations were recognized; most of them represent piedmont facies with local provenance from Precordillera and were deposited in the wedge-top depozone, as is expected for proximal sinorogenic deposits. However there are intercalations of transference fluvial systems, which show mixed provenance indicating that Permo-Triassic igneous rocks were already exposed to the west (Frontal Cordillera). There are also lacustrine deposits which are interpreted as the result of damming by fault activity at east of the studied basin. Finally, two maximum depositional ages at ca. 11 Ma and 8 Ma of these deposits indicate that the onset of uplift of the Precordillera at 30°S is little older than 11 Ma. These data change two previous ideas about the evolution of the Precordillera: its uplift at 30° S is younger than proposed by previous works and it is nearly synchronous along strike.

Deposition of steeply infalling debris around white dwarf stars

Science.gov (United States)

Brown, John C.; Veras, Dimitri; Gänsicke, Boris T.

2017-06-01

High-metallicity pollution is common in white dwarf (WD) stars hosting remnant planetary systems. However, they rarely have detectable debris accretion discs, possibly because much of the influx is fast steeply infalling debris in star-grazing orbits, producing a more tenuous signature than a slowly accreting disc. Processes governing such deposition between the Roche radius and photosphere have so far received little attention and we model them here analytically by extending recent work on sun-grazing comets to WD systems. We find that the evolution of cm-to-km size (a0) infallers most strongly depends on two combinations of parameters, which effectively measure sublimation rate and binding strength. We then provide an algorithm to determine the fate of infallers for any WD, and apply the algorithm to four limiting combinations of hot versus cool (young/old) WDs with snowy (weak, volatile) versus rocky (strong, refractory) infallers. We find: (I) Total sublimation above the photosphere befalls all small infallers across the entire WD temperature (TWD) range, the threshold size rising with TWD and 100× larger for rock than snow. (II) All very large objects fragment tidally regardless of TWD: for rock, a0 ≽ 105 cm; for snow, a0 ≽ 103-3 × 104 cm across all WD cooling ages. (III) A considerable range of a0 avoids fragmentation and total sublimation, yielding impacts or grazes with cold WDs. This range rapidly narrows with increasing TWD, especially for snowy bodies. Finally, we briefly discuss how the various forms of deposited debris may finally reach the photosphere surface itself.

Biogenic CaCO3 and Opal Depositions and Their Latitudinal Comparison During the Past 600 ka in the Central Equatorial Pacific

Directory of Open Access Journals (Sweden)

Boo-Keun Khim

2015-01-01

Full Text Available The orbital-scale variations in biogenic CaCO3 and opal abundance in two piston cores collected in the central equatorial Pacific (core PC5101 from a southern site at _ and core PC5103 from a northern site at _ were compared to assess latitudinal differences. The correlation between the oxygen isotope stratigraphy of planktonic foraminifera (Globigerinoides sacculifer of PC5103 with the LR04 stacks provides the age of PC5103 to be approximately 950 ka. The age of PC5103 was further refined by correlating the CaCO3 content with the well-dated core RC11-210. The age of PC5101 was also constrained by the same CaCO3 chronostratigraphic correlation with RC11-210, resulting in an age of approximately 650 ka. Distinct orbital-scale series of CaCO3 and opal variations appear to be parallel between the two cores during the past 600 ka, which are controlled mainly by eccentricity with an approximate periodicity of 100 ka. It is worth noting that the biogenic CaCO3 and opal deposition patterns in the two cores differ between interglacial and glacial periods. During interglacial periods the biogenic opal content is higher in the southern core than in the northern core, which corresponds with the present-day condition. In contrast the CaCO3 content is higher in the northern core, which is contradictory to the present-day northward decreasing CaCO3 deposition pattern from the Equator. The collection site of PC5101 is approximately 350 m deeper than that of PC5103, which significantly promotes CaCO3 dissolution and causes unexpectedly high CaCO3 content at the northern site in contrast to the biogenic opal content.

Particulate deposition in the human lung under lunar habitat conditions.

Science.gov (United States)

Darquenne, Chantal; Prisk, G Kim

2013-03-01

Lunar dust may be a toxic challenge to astronauts. While deposition in reduced gravity is less than in normal gravity (1 G), reduced gravitational sedimentation causes particles to penetrate deeper in the lung, potentially causing more harm. The likely design of the lunar habitat has a reduced pressure environment and low-density gas has been shown to reduce upper airway deposition and increase peripheral deposition. Breathing air and a reduced-density gas approximating the density of the proposed lunar habitat atmosphere, five healthy subjects inhaled 1 -microm diameter aerosol boluses at penetration volumes (V(p)) of 200 ml (central airways), 500 ml, and 1000 ml (lung periphery) in microgravity during parabolic flight, and in 1 G. Deposition in the lunar habitat was significantly less than for Earth conditions (and less than in 1 G with the low-density gas) with a relative decrease in deposition of -59.1 +/- 14.0% (-46.9 +/- 11.7%), -50.7 +/- 9.2% (-45.8 +/- 11.2%), and -46.0 +/- 8.3% (-45.3 +/- 11.1%) at V(p) = 200, 500, and 1000 ml, respectively. There was no significant effect of reduced density on deposition in 1 G. While minimally affected by gas density, deposition was significantly less in microgravity than in 1 G for both gases, with a larger portion of particles depositing in the lung periphery under lunar conditions than Earth conditions. Thus, gravity, and not gas properties, mainly affects deposition in the peripheral lung, suggesting that studies of aerosol transport in the lunar habitat need not be performed at the low density proposed for the atmosphere in that environment.

Indico central - events organisation, ergonomics and collaboration tools integration

International Nuclear Information System (INIS)

Gonzalez Lopez, Jose Benito; Ferreira, Jose Pedro; Baron, Thomas

2010-01-01

While the remote collaboration services at CERN slowly aggregate around the Indico event management software, its new version which is the result of a careful maturation process includes improvements which will set a new reference in its domain. The presentation will focus on the description of the new features of the tool, the user feedback process which resulted in a new record of usability. We will also describe the interactions with the worldwide community of users and server administrators and the impact this has had on our development process, as well as the tools set in place to streamline the work between the different collaborating sites. A last part will be dedicated to the use of Indico as a central hub for operating other local services around the event organisation (registration epayment, audiovisual recording, webcast, room booking, and videoconference support)

Indico central - events organisation, ergonomics and collaboration tools integration

Energy Technology Data Exchange (ETDEWEB)

Gonzalez Lopez, Jose Benito; Ferreira, Jose Pedro; Baron, Thomas, E-mail: jose.benito.gonzalez@cern.c, E-mail: jose.pedro.ferreira@cern.c, E-mail: thomas.baron@cern.c [CERN IT-UDS-AVC, 1211 Geneve 23 (Switzerland)

2010-04-01

While the remote collaboration services at CERN slowly aggregate around the Indico event management software, its new version which is the result of a careful maturation process includes improvements which will set a new reference in its domain. The presentation will focus on the description of the new features of the tool, the user feedback process which resulted in a new record of usability. We will also describe the interactions with the worldwide community of users and server administrators and the impact this has had on our development process, as well as the tools set in place to streamline the work between the different collaborating sites. A last part will be dedicated to the use of Indico as a central hub for operating other local services around the event organisation (registration epayment, audiovisual recording, webcast, room booking, and videoconference support)

Indico Central - Events Organisation, Ergonomics and Collaboration Tools Integration

CERN Document Server

Gonzalez Lopez, J B; Baron, T; CERN. Geneva. IT Department

2010-01-01

While the remote collaboration services at CERN slowly aggregate around the Indico event management software, its new version which is the result of a careful maturation process includes improvements which will set a new reference in its domain. The presentation will focus on the description of the new features of the tool, the user feedback process which resulted in a new record of usability. We will also describe the interactions with the worldwide community of users and server administrators and the impact this has had on our development process, as well as the tools set in place to streamline the work between the different collaborating sites. A last part will be dedicated to the use of Indico as a central hub for operating other local services around the event organisation (registration epayment, audiovisual recording, webcast, room booking, and videoconference support)

Geologic appraisal of Paradox basin salt deposits for water emplacement

Science.gov (United States)

Hite, Robert J.; Lohman, Stanley William

1973-01-01

Thick salt deposits of Middle Pennsylvanian age are present in an area of 12,000 square miles in the Paradox basin of southeast Utah and southwest Colorado. The deposits are in the Paradox Member of the Hermosa Formation. The greatest thickness of this evaporite sequence is in a troughlike depression adjacent to the Uncompahgre uplift on the northeast side of the basin.The salt deposits consist of a cyclical sequence of thick halite units separated by thin units of black shale, dolomite, and anhydrite. Many halite units are several hundred feet thick and locally contain economically valuable potash deposits.Over much of the Paradox basin the salt deposits occur at depths of more than 5,000 feet. Only in a series of salt anticlines located along the northeastern side of the basin do the salt deposits rise to relatively shallow depths. The salt anticlines can be divided geographically and structurally into five major systems. Each system consists of a long undulating welt of thickened salt over which younger rocks are arched in anticlinal form. Locally there are areas along the axes of the anticlines where the Paradox Member was never covered by younger sediments. This allowed large-scale migration of Paradox strata toward and up through these holes in the sediment cover forming diapiric anticlines.The central or salt-bearing cores of the anticlines range in thickness from about 2,500 to 14,000 feet. Structure in the central core of the salt anticlines is the result of both regional-compression and flowage of the Paradox Member into the anticlines from adjacent synclines. Structure in the central cores of the salt anticlines ranges from relatively undeformed beds to complexly folded and faulted masses, in which stratigraphic continuity is undemonstrable.The presence of thick cap rock .over many of the salt anticlines is evidence of removal of large volumes of halite by groundwater. Available geologic and hydrologic information suggests that this is a relatively slow

Christmas Island lagoonal lakes, models for the deposition of carbonate–evaporite–organic laminated sediments

OpenAIRE

Trichet , Jean; Défarge , Christian; Tribble , J.; Tribble , G.W.; Sansone , F.J.

2001-01-01

The atoll of Christmas Island (now known as Kiritimati) in the Kiribati Republic (Central Pacific) lies at about 2°N in the intertropical convergence zone. Much of the surface area of the atoll (ca. 360 km2) is occupied by numerous lakes in which carbonate, evaporite (calcium sulfate, halite) and organic layers are deposited. Observations suggest that deposition of these different laminae is controlled by climatic and biologic factors. It is thought that periodic climatic variations, such as ...

Effect of electron degeneracy on fast-particles energy deposition in dense plasma systems

International Nuclear Information System (INIS)

Johzaki, T.; Nakao, Y.; Nakashima, H.; Kudo, K.

1997-01-01

The effects of electron degeneracy on fast-particles energy deposition in dense plasmas are investigated by making transport calculations for the fast particles. It is found that the degeneracy substantially affects the profiles of energy deposition of 3.52-MeV α-particles. On the other hand, the effect on the energy deposition of 14.1-MeV neutrons is negligibly small because the recoil ions, which transfer the neutron energy to the plasma constituents, are produced in a whole plasma volume due to the long mean-free-path of neutrons. The coupled transport-hydrodynamic calculations show that these effects of degeneracy are negligible in the ignition and burn characteristics of central ignition D-T targets. (author)

APPLICATION OF MAGNETIC SURVEY TO EXPLORE THE IRON ORE DEPOSITS IN THE NUSAWUNGU COASTAL REGENCY OF CILACAP CENTRAL JAVA

Directory of Open Access Journals (Sweden)

S Sehah

2017-12-01

Full Text Available The research aiming to explore the iron ore deposits in the Nusawungu coastal Regency of Cilacap has been conducted using the magnetic survey. The acquisition of magnetic data was conducted in April – Mei 2017, covering the area in the ranges of 109.314° – 109.345°E and 7.691° – 7.709°S. The obtained magnetic field strength data were corrected, reduced, and mapped to obtain the contour map of local magnetic anomaly. The modeling process was carried out along the path extending over the map from the positions of 109.314°E and 7.695°S to 109.335°E and 7.699°S, so that some subsurface anomalous objects are obtained. The lithological interpretation was performed to identify the types of subsurface rocks and their formations based on the magnetic susceptibility value of each anomalous objects and supported by the geological information of the research area. Based on the interpretation results, three rocks deposits of alluvium formations were obtained, which are estimated to contain iron ore. The first deposit has a length of 164.85 m, a depth of 0.57 – 8.43 m, and a magnetic susceptibility value of 0.0097 cgs. The second deposit has a length of 376.28 m, a depth of 2.56 – 19.66 m, and a magnetic susceptibility value of 0.0108 cgs. The third deposit has a length of 1,306.26 m, a depth of 3.70 – 58.69 m, and a magnetic susceptibility value of 0.0235 cgs. Out of the whole rocks deposits, the third rock deposit is interpreted to have the most prospective iron ore. This interpretation based on its high magnetic susceptibility value, which indicates the presence of many magnetic minerals (i.e. iron ores in the rock.

Atmospheric wet deposition of mercury in North America

Energy Technology Data Exchange (ETDEWEB)

Sweet, C.W.; Prestbo, E.; Brunette, B.

1999-07-01

Currently, 39 states in the US and 5 Canadian provinces have issued advisories about the dangers of eating mercury-contaminated fish taken from waters within their boundaries. The problem is most severe in the Great Lakes region, the Northeast US states, the Canadian maritime provinces, and in south Florida where many lakes and streams contain fish with concentrations of 1 ppm or higher. For many rural and remote locations, atmospheric deposition is the primary source of mercury. In 1995, the National Atmospheric Deposition Program (NADP) initiated a program to monitor total mercury and methylmercury (MMHg) in wet deposition (rain and snow) in North America. In this program, the Mercury Deposition Network (MDN), individual monitoring sites are funded and operated by a variety of local, state, and federal agencies. However, sampling and analysis are coordinated through a central laboratory so that all of the samples are collected and analyzed using the same protocols. Weekly wet-only precipitation samples are collected using an all-glass sampling train and special handling techniques. Analysis is by cold vapor atomic fluorescence spectrometry using USEPA Method 1631 for total mercury. Nearly 40 MDN sites are in operation in 1999. Most of the sites are in the eastern US and Canada. During 1996 and 1997, the volume-weighted mean concentration of total mercury in precipitation collected at 22 sites ranged from 6.0 to 18.9 ng/L. Annual deposition varied between 2.1 and 25.3 {micro} g/m{sup 2}. The average weekly wet deposition of total mercury is more than three times higher in the summer (June-August) than in the winter (December-February). This increase is due to both higher amounts of precipitation and higher concentrations of mercury in precipitation during the summer. The highest values for mercury concentration in precipitation and wet deposition of mercury were measured in the southeastern US.

Validating CFD Predictions of Pharmaceutical Aerosol Deposition with In Vivo Data.

Science.gov (United States)

Tian, Geng; Hindle, Michael; Lee, Sau; Longest, P Worth

2015-10-01

CFD provides a powerful approach to evaluate the deposition of pharmaceutical aerosols; however, previous studies have not compared CFD results of deposition throughout the lungs with in vivo data. The in vivo datasets selected for comparison with CFD predictions included fast and slow clearance of monodisperse aerosols as well as 2D gamma scintigraphy measurements for a dry powder inhaler (DPI) and softmist inhaler (SMI). The CFD model included the inhaler, a characteristic model of the mouth-throat (MT) and upper tracheobronchial (TB) airways, stochastic individual pathways (SIPs) representing the remaining TB region, and recent CFD-based correlations to predict pharmaceutical aerosol deposition in the alveolar airways. For the monodisperse aerosol, CFD predictions of total lung deposition agreed with in vivo data providing a percent relative error of 6% averaged across aerosol sizes of 1-7 μm. With the DPI and SMI, deposition was evaluated in the MT, central airways (bifurcations B1-B7), and intermediate plus peripheral airways (B8 through alveoli). Across these regions, CFD predictions produced an average relative error <10% for each inhaler. CFD simulations with the SIP modeling approach were shown to accurately predict regional deposition throughout the lungs for multiple aerosol types and different in vivo assessment methods.

Ways of distinguishing epigenetic types of gray-colored rocks in sheet-infiltration deposits

International Nuclear Information System (INIS)

Rasulova, S.D.; Yashunskii, Yu.V.

1994-01-01

At an infiltration deposit of uranium in Upper-Cretaceous sandy-clay alluvial deposits (Central Kyzylkum), six stages of postsedimentation epigenetic transformations were distinguished. The genesis of altered rocks was determined mostly by mineralogical methods. A new methodological technique is suggested, which calls for analysis of the textural, structural, and mineral correspondence of ferruginous components of gray-colored and oxidized rocks in the region of their contact and makes it possible to typify epigenetic changes in conditions of repeated change in the direction of geochemical processes

Identifying the source of fluvial terrace deposits using XRF scanning and Canonical Discriminant Analysis: A case study of the Chihshang terraces, eastern Taiwan

Science.gov (United States)

Chang, Queenie; Lee, Jian-Cheng; Hunag, Jyh-Jaan; Wei, Kuo-Yen; Chen, Yue-Gau; Byrne, Timothy B.

2018-05-01

The source of fluvial deposits in terraces provides important information about the catchment fluvial processes and landform evolution. In this study, we propose a novel approach that combines high-resolution Itrax-XRF scanning and Canonical Discriminant Analysis (CDA) to identify the source of fine-grained fluvial terrace deposits. We apply this approach to a group of terraces that are located on the hanging wall of the Chihshang Fault in eastern Taiwan with two possible sources, the Coastal Range on the east and the Central Range on the west. Our results of standard samples from the two potential sources show distinct ranges of canonical variables, which provided a better separation ability than individual chemical elements. We then tested the possibility of using this approach by applying it to several samples with known sediment sources and obtain positive results. Applying this same approach to the fine-grained sediments in Chihshang terraces indicates that they are mostly composed of Coastal Range material but also contain some inputs from the Central Range. In two lowest terraces T1 and T2, the fine-grained deposits show significant Central Range component. For terrace T4, the results show less Central Range input and a trend of decreasing Central Range influences up section. The Coastal Range material becomes dominant in the two highest terraces T7 and T10. Sediments in terrace T5 appear to have been potentially altered by post-deposition chemical alteration processes and are not included in the analysis. Our results show that the change in source material in the terraces deposits was relatively gradual rather than the sharp changes suggested by the composition of the gravels and conglomerates. We suggest that this change in sources is related to the change in dominant fluvial processes that controlled by the tectonic activity.

The first step in layer-by-layer deposition: Electrostatics and/or non-electrostatics?

NARCIS (Netherlands)

Lyklema, J.; Deschênes, L.

2011-01-01

A critical discussion is presented on the properties and prerequisites of adsorbed polyelectrolytes that have to function as substrates for further layer-by-layer deposition. The central theme is discriminating between the roles of electrostatic and non-electrostatic interactions. In order to

Monitoring the impact of simulated deep-sea mining in Central Indian Basin

Digital Repository Service at National Institute of Oceanography (India)

Sharma, R.; Nath, B.N.; Jaisankar, S.

Monitoring the Impact of Simulated Deep-sea Mining in Central Indian Basin R. SHARMA, B. NAGENDER NATH, AND S. JAI SANKAR National Institute of Oceanography, Dona Paula, Goa, India Monitoring of deep-sea disturbances, natural or man-made, has gained... has shown a partial recovery of the benthic ecosystem, with indications of restoration and recolonization. Keywords deep-sea mining, environmental impact, Central Indian Basin Deep-sea mineral deposits such as the polymetallic nodules and crusts...

About peculiarities of hydrocarbons deposits location in the productive series of the Baku archipelago area

International Nuclear Information System (INIS)

Gasanov, V.T.

2002-01-01

Full text : In Azerbaijan domestic and foreign companies hold wide-scaled prospecting operations in the central and southern parts of the Baku Archipelago and also in the Kobystan. There are hydrocarbons deposits determined in the northern of the Baku Archipelago. Deposits location by phase condition of hydrocarbons mainly follows the general regularity determined on many oil and gas bearing areas, pass of oil deposits to oil-gas and gas-condensate ones in the direction of increase of layers occurrence depth. There is also a considerable influence of a tectonic factor on the area location of deposits observed, expressing in difference of deposits height on different tectonic blocks and also there is an influence of a lithological factor. Results of works conducted on drilling and wells testing are still not enough for judging about lack of oil and gas content.

GEOLOGY OF THE FLORENCIA GOLD – TELLURIDE DEPOSIT (CAMAGÜEY, CUBA AND SOME METALLURGICAL CONSIDERATIONS

Directory of Open Access Journals (Sweden)

López K Jesús M.

2006-12-01

Full Text Available This paper describes the results from a study of the Florencia gold-telluride deposit in Central Cuba, including mineralogical, petrographical, microprobe and chemical analysis. Valuable information is provided for the exploration, mining and processing of gold ores from other nearby deposits with similar characteristics. Results highlight changes in the mineralogical composition of the ores between the north and south sectors of the deposit, as reflected in metallurgical concentrates after beneficiation and flotation of samples from these sectors.
It is shown that gold deposits of the Cretaceous Volcanic Arc of Cuba largely consist of native gold, telluride and pyrite, where arsenopyrite is almost absent. Traces of lead, zinc and cadmium are present in the periphery of the main ore zones.

Health impacts of mercury cycling in contaminated environments of central India studied by NAA and ICP-MS

International Nuclear Information System (INIS)

Patel, K.S.

2001-01-01

The heavy metal pollution in the Indian continent is increasing due to rapid industrialisation. Among heavy metals, the element: mercury is considered as global pollutant. In central India it is considered as global pollutant. Central India has been chosen for the investigation of the mercury pollution and their health impacts in the proposed project. The concentration and flux levels of the organic, inorganic and total mercury and their variations, sources and co-relation are investigated in various atmospheric and environmental compartments air, dry deposit, wet deposits, water, soil, sediment, etc. of central India lying between 18-23 deg. N latitude and 80-84 deg. longitude. The techniques CVAAS, NAA, XFS, ICP-MS, etc. would be used for monitoring the various chemical species of mercury employing established methodologies. (author)

Pele Plume Deposit on Io

Science.gov (United States)

1997-01-01

The varied effects of Ionian volcanism can be seen in this false color infrared composite image of Io's trailing hemisphere. Low resolution color data from Galileo's first orbit (June, 1996) have been combined with a higher resolution clear filter picture taken on the third orbit (November, 1996) of the spacecraft around Jupiter.A diffuse ring of bright red material encircles Pele, the site of an ongoing, high velocity volcanic eruption. Pele's plume is nearly invisible, except in back-lit photographs, but its deposits indicate energetic ejection of sulfurous materials out to distances more than 600 kilometers from the central vent. Another bright red deposit lies adjacent to Marduk, also a currently active ediface. High temperature hot spots have been detected at both these locations, due to the eruption of molten material in lava flows or lava lakes. Bright red deposits on Io darken and disappear within years or decades of deposition, so the presence of bright red materials marks the sites of recent volcanism.This composite was created from data obtained by the Solid State Imaging (CCD) system aboard NASA's Galileo spacecraft. The region imaged is centered on 15 degrees South, 224 degrees West, and is almost 2400 kilometers across. The finest details that can be discerned in this picture are about 3 kilometers across. North is towards the top of the picture and the sun illuminates the surface from the west.The Jet Propulsion Laboratory, Pasadena, CA manages the mission for NASA's Office of Space Science, Washington, DC.This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URL http://galileo.jpl.nasa.gov. Background information and educational context for the images can be found at URL http://www.jpl.nasa.gov/galileo/sepo

Miocene tectonic history of the Central Tauride intramontane basins, and the paleogeographic evolution of the Central Anatolian Plateau

Science.gov (United States)

Koç, Ayten; Kaymakci, Nuretdin; Van Hinsbergen, Douwe J. J.; Kuiper, Klaudia F.

2017-11-01

Marine Lower-Upper Miocene deposits uplifted to > 2 km elevation in the Tauride mountains of southern Turkey are taken as evidence for the rise of a nascent plateau. The dynamic causes of this uplift are debated, but generally thought to be a regional dynamic topographic effect of slab motions or slab break-off. Immediately adjacent to the high Tauride mountains lie the Central Tauride Intramontane Basins, which consist of Miocene and younger fluvio-lacustrine basins, at much lower elevations than the highly uplifted marine Miocene rocks. These basins include the previously analyzed Altınapa and Yalvaç basins, as well as the until now undescribed Ilgın Basin. In this paper, we aim to constrain the paleogeography of the Central Tauride Intramontane Basins and determine the role of the tectonics driving the formation of the high Miocene topography in southern Turkey. Therefore, we provide new data on the stratigraphy, sedimentology and structure of the continental Ilgın Basin. We provide an 40Ar/39Ar age of 11.61 ± 0.05 Ma for pumice deposits in the stratigraphy. We provide paleostress inversion analysis based on growth faults showing that the basin formed during multi-directional extension, with NE-SW to E-W dominating over subordinate Nsbnd S extension. We conclude that major, still-active normal faults like the Akşehir Fault also controlled Miocene Ilgın basin formation, with proximal facies close to the basin margins grading upwards and basinwards into lacustrine deposits representing the local depocenter. The Ilgın Basin was a local depocenter, but it may have connected with the adjacent Altınapa Basin during high lake levels in late Serravallian time. The Ilgın Basin and the other continental basins provide key constraints on the paleogeography and tectonic history of the region. These continental basins were likely close to the paleo-coastline during the Late Miocene after which there must have been major differential uplift of the Taurides. We

Pb-Zn mineralization of Ali ou Daoud area (Central High Atlas, Morocco: characterisation of deposit and relationship with the clay assemblages

Directory of Open Access Journals (Sweden)

Daoudi, L.

2008-12-01

Full Text Available Zn-Pb-Fe ores in the Ali ou Daoud deposit (Central High Atlas are found as stratiform levels and as karst fillings in carbonate platforms facies of Bajocian age. Tectonic structures (e.g., synsedimentary faults played a relevant role in the ore emplacement. The dolomitic ore-related host-rock levels are characterized by the presence of kaolinite enrichment in clay levels in amounts directly related to the proportion of the clay minerals. The latter is evidenced by correlation between kaolinite and sulphide contents, suggesting that the installation of kaolinite and mineralisations would result from the same hydrothermal fluid.[Français] Dans les séries sédimentaires carbonatées d’Ali ou Daoud (Haut Atlas Central, les minéralisations à Zn, Pb et Fe en amas stratiformes forment les faciès de remplissage des karsts d’une plateforme carbonatée bajocienne. Le contrôle structural joue un rôle capital dans la localisation du gîte en bordure de plateforme sur des failles synsédimentaires. Dans les niveaux dolomitiques encaissants des minéralisations, les assemblages argileux sont caractérisés par la présence de kaolinite dont la teneur varie parallèlement avec celle du minerai. Ceci suggère que la mise en place de la kaolinite et des minéralisations résulterait du même fluide hydrothermal. [Español] En las series sedimentarias carbonatadas de Ali ou Daoud (Alto Atlas Central, las mineralizaciones de Zn, Pb y Fe aparecen en niveles estratiformes como facies de reemplazamiento de los karsts de una plataforma carbonatada Bajociense. El control estructural desempeña un papel crucial en la localización del yacimiento a lo largo de la plataforma sobre fallas sinsedimentarias. En los niveles dolomíticos que incluyen las mineralizaciones, las asociaciones arcillosas se caracterizan por la presencia de caolinita, cuyo contenido varía paralelamente al de la mineralización. Esto sugiere que la creación de caolinita y de la

Neutrino Astrophysics in Slowly Rotating Spacetimes Permeated by Nonlinear Electrodynamics Fields

Science.gov (United States)

Mosquera Cuesta, Herman J.

2017-02-01

Many theoretical and astrophysical arguments involve consideration of the effects of super strong electromagnetic fields and the rotation during the late stages of core-collapse supernovae. In what follows, we solve Einstein field equations that are minimally coupled to an arbitrary (current-free) Born-Infeld nonlinear Lagrangian L(F,G) of electrodynamics (NLED) in the slow rotation regime a ≪ r+ (outer horizon size), up to first order in a/r. We cross-check the physical properties of such NLED spacetime w.r.t. against the Maxwell one. A study case on both neutrino flavor ({ν }e\\to {ν }μ ,{ν }τ ) oscillations and flavor+helicity (spin) flip ({ν }e\\to {\\overline{ν }}μ ,τ ) gyroscopic precession proves that in the spacetime of a slowly rotating nonlinear charged black hole (RNCBH), the neutrino dynamics translates into a positive enhancement of the r-process (reduction of the electron fraction Ye < 0.5). Consequently, it guarantees successful hyperluminous core-collapse supernova explosions due to the enlargement of the number and amount of decaying nuclide species. This posits that, as far as the whole luminosity is concerned, hypernovae will be a proof of the formation of astrophysical RNCBH.

Changes in erosional and depositional processes with time and management of Goa Coast, central west coast of India

Science.gov (United States)

Nayak, Ganapati; D'Souza, Joseph

2010-05-01

Coastal and estuarine environments, world over are facing immense impact due to both natural and anthropogenic processes. The natural processes include climatic changes, rise in sea level, cyclone, flood, tsunamis, coastal erosion, salinity ingress and siltation. Likewise, anthropogenic pressures include population expansion, ocean traffic, dredging, resource exploitation, pollution, unplanned urbanization and intensive industrialization. Due to these impacts the fragile coastal ecosystem and its entities, like sub ecosystems, resources, morphological units are undergoing unprecedented degradation, rendering these coastal regions vulnerable, impinging risk to human population, livestock, properties, as also, devastation of resourceful lands. This accelerates economic fatalities and irreversible obliteration to the ecosystems. Evidences on the global concern towards this issue have been well established. The countries world over, including India, pledged consensus towards the protection of the fragile coastal ecosystems through UNCED, Agenda-21. India, on 19th February 1991, has designated specified corridors along the landward side of the coastline as "Coastal Regulatory Zones" (CRZ), through appropriate policy and law. In context with the CRZ notification, scientific database at local and site-specific areas, developed. Synergy of ecosystems, landscape and resources with demographic, tourism data, vis-à-vis, economic corridors/sectors aided the paradigms and criterion for local and site specific prescriptions for Goa Coast. The Goa coast is a part of central west coast of India and is characterized by pocket beaches flanked by rocky cliffs, estuaries, bays, and at some places mangroves. Beaches in southern Goa are long and linear in nature with sand dunes. The Mandovi and Zuari estuarine system in Goa is the largest in this part of the coast. Mud flats, swampy marshes and wetlands are found mainly along estuaries and creeks. The beaches of Goa are stable beaches

Spatial patterns and temporal changes in atmospheric-mercury deposition for the midwestern USA, 2001–2016

Science.gov (United States)

Risch, Martin R.; Kenski, Donna M.

2018-01-01

Spatial patterns and temporal changes in atmospheric-mercury (Hg) deposition were examined in a five-state study area in the Midwestern USA where 32% of the stationary sources of anthropogenic Hg emissions in the continental USA were located. An extensive monitoring record for wet and dry Hg deposition was compiled for 2001–2016, including 4666 weekly precipitation samples at 13 sites and 27 annual litterfall-Hg samples at 7 sites. This study is the first to examine these Hg data for the Midwestern USA. The median annual precipitation-Hg deposition at the study sites was 10.4 micrograms per square meter per year (ug/m2/year) and ranged from 5.8 ug/m2/year to 15.0 ug/m2/year. The median annual Hg concentration was 9.4 ng/L. Annual litterfall-Hg deposition had a median of 16.1 ug/m2/year and ranged from 9.7 to 23.4 ug/m2/year. Isopleth maps of annual precipitation-Hg deposition indicated a recurring spatial pattern similar to one revealed by statistical analysis of weekly precipitation-Hg deposition. In that pattern, high Hg deposition in southeastern Indiana was present each year, frequently extending to southern Illinois. Most of central Indiana and central Illinois had similar Hg deposition. Areas with comparatively lower annual Hg deposition were observed in Michigan and Ohio for many years and frequently included part of northern Indiana. The area in southern Indiana where high Hg deposition predominated had the highest number of extreme episodes of weekly Hg deposition delivering up to 15% of the annual Hg load from precipitation in a single week. Modeled 48-h back trajectories indicated air masses for these episodes often arrived from the south and southwest, crossing numerous stationary sources of Hg emissions releasing from 23 to more than 300 kg Hg per year. This analysis suggests that local and regional, rather than exclusively continental or global Hg emissions were likely contributing to the extreme episodes and at least in part, to the spatial

How were Neolithic ditches filled in? Deposition study of two enclosures from Bohemia

Czech Academy of Sciences Publication Activity Database

Řídký, Jaroslav; Končelová, Markéta; Šumberová, Radka; Limburský, Petr; Květina, Petr

2014-01-01

Roč. 17, č. 4 (2014), s. 579-601 ISSN 1461-9571 R&D Projects: GA ČR(CZ) GAP405/11/1590 Institutional support: RVO:67985912 Keywords : Late Neolithic * Central Europe * circular enclosures * rondels * formation processes * deposition Subject RIV: AC - Archeology, Anthropology, Ethnology

Constrained Magnetostratigraphic Dating of a Continental Middle Miocene Section in the Arid Central Asia

Directory of Open Access Journals (Sweden)

Verena Verestek

2018-05-01

Full Text Available The Neogene succession of the Aktau Mountains in the Ili Basin, southeast Kazakhstan, is a terrestrial archive well suited for researching the role of Central Asia in Miocene climate evolution. We present an integrated approach for dating the well-exposed Bastau Formation, based on magnetostratigraphy and constraints from cyclostratigraphy and biostratigraphy. Stepwise demagnetization yielded characteristic remanence directions that are consistent with those expected for the Miocene in Central Asia. The reddish-colored alluvial floodplain deposits and gray lacustrine deposits show partly complex magnetic behavior with magnetite and hematite as the main magnetic carriers, with variable demagnetization behavior and non-dipolar normal and reverse polarity directions. The observed magnetic properties are best explained by depositional variability and magneto-mineralogical alteration effects of both dissolution and neo-formation of magnetite, including significant secondary magnetization. The mean of reverse polarity directions is flatter than the expected Middle Miocene Earth magnetic field, which is an indicator for the existence of inclination shallowing that supports a primary origin. Detailed rock magnetic analyses are used to analyze the nature of the characteristic remanent magnetization and to discriminate primary and secondary remanence directions in order to obtain a reliable magnetostratigraphic result. The proposed age of 15.3–13.9 Ma for the Bastau Formation corresponds to the known biostratigraphic setting, matches with typical sedimentation rates of foreland basins in Central Asia, and coincides with spectral analysis of geochemical proxies of that section. The resulting age model serves as a robust framework for paleoclimate reconstruction of Neogene climate dynamics in Central Asia.

Data integration modeling applied to drill hole planning through semi-supervised learning: A case study from the Dalli Cu-Au porphyry deposit in the central Iran

Science.gov (United States)

Fatehi, Moslem; Asadi, Hooshang H.

2017-04-01

In this study, the application of a transductive support vector machine (TSVM), an innovative semi-supervised learning algorithm, has been proposed for mapping the potential drill targets at a detailed exploration stage. The semi-supervised learning method is a hybrid of supervised and unsupervised learning approach that simultaneously uses both training and non-training data to design a classifier. By using the TSVM algorithm, exploration layers at the Dalli porphyry Cu-Au deposit in the central Iran were integrated to locate the boundary of the Cu-Au mineralization for further drilling. By applying this algorithm on the non-training (unlabeled) and limited training (labeled) Dalli exploration data, the study area was classified in two domains of Cu-Au ore and waste. Then, the results were validated by the earlier block models created, using the available borehole and trench data. In addition to TSVM, the support vector machine (SVM) algorithm was also implemented on the study area for comparison. Thirty percent of the labeled exploration data was used to evaluate the performance of these two algorithms. The results revealed 87 percent correct recognition accuracy for the TSVM algorithm and 82 percent for the SVM algorithm. The deepest inclined borehole, recently drilled in the western part of the Dalli deposit, indicated that the boundary of Cu-Au mineralization, as identified by the TSVM algorithm, was only 15 m off from the actual boundary intersected by this borehole. According to the results of the TSVM algorithm, six new boreholes were suggested for further drilling at the Dalli deposit. This study showed that the TSVM algorithm could be a useful tool for enhancing the mineralization zones and consequently, ensuring a more accurate drill hole planning.

SEDIMENTARY LOW-MANGANESE HEMATITE DEPOSITS OF THE BUKOVICA AREA IN THE NORTHWESTERN MT. PETROVA GORA, CENTRAL CROATIA

Directory of Open Access Journals (Sweden)

Milivoj Čop

1998-12-01

Full Text Available Middle-Permian Gröden deposits crop out on the surface of 0.8 km in the Bukovica area and on the surface of 0.8 km2 in the Mt. Loskun-jska gora in the NW part of the Petrova gora Mountain. One half of the Bukovica Gröden deposits contains in its lowest parts 1 to 5 m (in average 2.5 m thick hematite bed cutted in blocks by NE-SW stretch¬ing vertical, normal and reverse faults. The hematite bed is unconfor-mably underlain by Lower Permian quartz-wackes (subgraywackes intercalated with shales intercalations. Ore deposit is explored by 308 boreholes (10509 m and by numerous adits, inclines and crosscuts on the underground surface of 0.4 km2 . From 1936 to 1941 and from 1953 to 1969 has been exploited 183000 t of ore with (in wt %: 34.0 Si02, 2.9 Al2O3; 59.0 Fe203; 0.15 MnO; 0.7 CaO; 0.4 MgO; 0.1 P, 0.37 S; 1.25 l.o. ign. Proven remaining ore reserves are 250.000 t. Paragenesis is investigated by microscopy of thin and polished sections, XRD, DTA, AAS analyses and by sedimentological analyses. Paragenesis major minerals are of hematite and quartz, with subordinate stable litho-clasts, muscovite (sericite and scarce kaolinite, calcite, dolomite, and barite. Accessories are zircon, rutile, tourmaline, amphibole, garnet, apatite. Epigenetic veinlets and small nests are built up of quartz or calcite as the main neominerals associated with siderite, barite, kaolinite, pyrite, gypsum. Iron from the Bukovica hematite ore origi¬nated by land weathering during hot climate and transported by rivers and underground waters deposited in river beds, in flood plains and in shallow sea. Precipitation of the Bukovica iron ores took place after the Saalic orogenetic phase. At Hrastno (SE Slovenia and at Rude nearby Samobor (Croatia, similar hematite deposits were found.

Nitrogen dynamics in oak forest soils along a historical deposition gradient

Science.gov (United States)

Ralph E. J. Boerner; Elaine Kennedy Sutherland

1995-01-01

This study quantified soil nutrient status and N mineralization/nitrification potentials in soils of oakdominated, unmanaged forest stands in seven experimental forests ranging along a historical and current acidic deposition gradient from southern Illinois to central West Virginia, U.S.A. Among these seven sites (that spanned 8.5º of longitude) soil pH and Ca...

Effects and quantification of acid runoff from sulfide-bearing rock deposited during construction of Highway E18, Norway

Science.gov (United States)

Hindar, Atle; Nordstrom, D. Kirk

2015-01-01

The Highway E18 between the cities of Grimstad and Kristiansand, southern Norway, constructed in the period 2006–2009, cuts through sulfide-bearing rock. The geology of this area is dominated by slowly-weathering gneiss and granites, and oxidation of fresh rock surfaces can result in acidification of surface water. Sulfide-containing rock waste from excavations during construction work was therefore deposited in three waste rock deposits off-site. The deposits consist of 630,000–2,360,000 metric tons of waste rock material. Shell sand and limestone gravel were added in layers in adequate amounts to mitigate initial acid runoff in one of the deposits. The shell sand addition was not adequate in the two others. The pH in the effluents from these two was reduced from 4.9–6.5 to 4.0–4.6, and Al concentrations increased from below 0.4 mg/L to 10–20 mg/L. Stream concentrations of trace metals increased by a factor of 25–400, highest for Ni, and then in decreasing order for Co, Mn, Cd, Zn and Cu. Concentrations of As, Cr and Fe remained unchanged. Ratios of Co/Ni and Cd/Zn indicate that the metal sources for these pair of metals are sphalerite and pyrite, respectively. Based on surveys and established critical limits for Al, surface waters downstream became toxic to fish and invertebrates. The sulfur release rates were remarkably stable in the monitoring period at all three sites. Annual sulfur release was 0.1–0.4% of the total amount of sulfur in the deposit, indicating release periods of 250–800 years. Precipitates of Al-hydroxysulfates, well-known from mining sites, were found at the base of the deposits, in streams and also along the ocean shore-line. The effects of added neutralization agents in the deposits and in treatment areas downstream gradually decreased, as indicated by reduced stream pH over time. Active measures are needed to avoid harmful ecological effects in the future.

Co-Cu-Au deposits in metasedimentary rocks-A preliminary report

Science.gov (United States)

Slack, J.F.; Causey, J.D.; Eppinger, R.G.; Gray, J.E.; Johnson, C.A.; Lund, K.I.; Schulz, K.J.

2010-01-01

A compilation of data on global Co-Cu-Au deposits in metasedimentary rocks refines previous descriptive models for their occurrence and provides important information for mineral resource assessments and exploration programs. This compilation forms the basis for a new classification of such deposits, which is speculative at this early stage of research. As defined herein, the Co-Cu-Au deposits contain 0.1 percent or more by weight of Co in ore or mineralized rock, comprising disseminated to semi-massive Co-bearing sulfide minerals with associated Fe- and Cu-bearing sulfides, and local gold, concentrated predominantly within rift-related, siliciclastic metasedimentary rocks of Proterozoic age. Some deposits have appreciable Ag ? Bi ? W ? Ni ? Y ? rare earth elements ? U. Deposit geometry includes stratabound and stratiform layers, lenses, and veins, and (or) discordant veins and breccias. The geometry of most deposits is controlled by stratigraphic layering, folds, axial-plane cleavage, shear zones, breccias, or faults. Ore minerals are mainly cobaltite, skutterudite, glaucodot, and chalcopyrite, with minor gold, arsenopyrite, pyrite, pyrrhotite, bismuthinite, and bismuth; some deposits have appreciable tetrahedrite, uraninite, monazite, allanite, xenotime, apatite, scheelite, or molybdenite. Magnetite can be abundant in breccias, veins, or stratabound lenses within ore or surrounding country rocks. Common gangue minerals include quartz, biotite, muscovite, K-feldspar, albite, chlorite, and scapolite; many deposits contain minor to major amounts of tourmaline. Altered wall rocks generally have abundant biotite or albite. Mesoproterozoic metasedimentary successions constitute the predominant geologic setting. Felsic and (or) mafic plutons are spatially associated with many deposits and at some localities may be contemporaneous with, and involved in, ore formation. Geoenvironmental data for the Blackbird mining district in central Idaho indicate that weathering of

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...

Interception and retention of 238Pu deposition by orange trees

International Nuclear Information System (INIS)

Pinder, J.E. III; Adriano, D.C.; Ciravolo, T.G.; Doswell, A.C.; Yehling, D.M.

1987-01-01

Radioisotope thermoelectric generators (RTG) transform the heat produced during the alpha decay of 238 Pu into electrical energy for use by deep-space probes, such as the Voyager spacecraft, which have returned images and other data from Jupiter, Saturn and Uranus. Future missions involving RTGs may be launched aboard the space shuttle, and there is a remote possibility that an explosion of liquid-hydrogen and liquid-oxygen fuel could rupture the RTGs and disperse 238 Pu into the atmosphere over central Florida. Research was performed to determine the potential transport to man of atmospherically dispersed Pu via contaminated orange fruits. The results indicate that the major contamination of oranges would result from the interception and retention of 238 Pu deposition by fruits. The resulting surface contamination could enter human food chains through transfer to internal tissues during peeling or in the reconstituted juices and flavorings made from orange skins. The interception of 238 Pu deposition by fruits is especially important because the results indicate no measurable loss of Pu from fruit surfaces through time or with washing. Approximately 1% of the 238 Pu deposited onto an orange grove would be harvested in the year following deposition

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)

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)

137Cs in a raised bog in central Sweden

International Nuclear Information System (INIS)

Rosen, K.; Vinichuk, M.; Johanson, K.J.

2009-01-01

The vertical distribution of 137 Cs activity in peat soil profiles and 137 Cs activity concentration in plants of various species was studied in samples collected at two sites on a raised bog in central Sweden. One site (open bog) was in an area with no trees and only a few sparsely growing plant species, while the other (low pine) was less than 100 m from the open bog site and had slowly growing Scots pine, a field layer dominated by some ericaceous plants and ground well-covered by plants. The plant samples were collected in 2004-2007 and were compared with samples collected in 1989 from the same open bog and low pine sites. Ground deposition of 137 Cs in 2005 was similar at both sites, 23 000 Bq m -2 . In the open bog peat profile it seems to be an upward transport of caesium since a clear peak of 137 Cs activity was found in the uppermost 1-4 cm of Sphagnum layers, whereas at the low pine site 137 Cs was mainly found in deeper (10-12 cm) layers. The migration rate was 0.57 cm yr -1 at the open bog site and the migration centre of 137 Cs was at a depth of 10.7, while the rate at the low pine site was 0.78 cm yr -1 and the migration centre was at 14.9 cm. Heather (Calluna vulgaris) was the plant species with the highest 137 Cs activity concentrations at both sites, 43.5 k Bq -1 DM in 1989 decreasing to 20.4 in 2004-2007 on open bog and 22.3 k Bq kg -1 DM in 1989 decreasing to 11.2 k Bq -1 DM by the period 2004-2007 on the low pine site. 137 Cs transfer factors in plants varied between 0.88 and 1.35 on the open bog and between 0.48 and 0.69 m 2 kg -1 DM at the low pine site.

Characteristics of debris avalanche deposits inferred from source volume estimate and hummock morphology around Mt. Erciyes, central Turkey

Directory of Open Access Journals (Sweden)

Y. S. Hayakawa

2018-02-01

Full Text Available Debris avalanches caused by volcano sector collapse often form characteristic depositional landforms such as hummocks. Sedimentological and geomorphological analyses of debris avalanche deposits (DADs are crucial to clarify the size, mechanisms, and emplacement of debris avalanches. We describe the morphology of hummocks on the northeastern flank of Mt. Erciyes in Kayseri, central Turkey, likely formed in the late Pleistocene. Using a remotely piloted aircraft system (RPAS and the structure-from-motion and multi-view stereo (SfM–MVS photogrammetry, we obtained high-definition digital elevation model (DEM and orthorectified images of the hummocks to investigate their geometric features. We estimated the source volume of the DAD by reconstructing the topography of the volcano edifice using a satellite-based DEM. We examined the topographic cross sections based on the slopes around the scar regarded as remnant topography. Spatial distribution of hummocks is anomalously concentrated at a certain distance from the source, unlike those that follow the distance–size relationship. The high-definition land surface data by RPAS and SfM revealed that many of the hummocks are aligned toward the flow direction of the debris avalanche, suggesting that the extensional regime of the debris avalanche was dominant. However, some displaced hummocks were also found, indicating that the compressional regime of the flow contributed to the formation of hummocks. These indicate that the flow and emplacement of the avalanche were constrained by the topography. The existing caldera wall forced the initial eastward flow to move northward, and the north-side caldera wall forced the flow into the narrow and steepened outlet valley where the sliding debris underwent a compressional regime, and out into the unconfined terrain where the debris was most likely emplaced on an extensional regime. Also, the estimated volume of 12–15 × 108 m3 gives a mean thickness of

Electrophoretic Deposition of Gallium with High Deposition Rate

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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.

Regional exploration for channel and playa uranium deposits in Western Australia using groundwater

International Nuclear Information System (INIS)

Noble, R.R.P.; Gray, D.J.; Reid, N.

2011-01-01

Shallow calcrete aquifers in the central north of the Yilgarn Craton in Western Australia are the host to numerous secondary carnotite U deposits. Sampling and analysis of approximately 1400 shallow aquifer groundwaters were conducted to test if U mineralisation of this type may be found using a >5 km sample spacing. Results show this can be achieved. All the economic deposits and most of the minor deposits and occurrences are associated with groundwater that has carnotite (KUO 2 VO 4 ) approaching or exceeding saturated conditions. Soluble U concentrations alone identified the largest deposit (Yeelirrie) and several smaller deposits, but this parameter was not as successful as the mineral saturation indices. Palaeodrainage distribution and thickness of cover combined with surface drainage and catchment boundaries provided background information of U primary sources and for areas with the highest exploration potential for channel and playa U deposits. Granites in the SE of the study area are less prospective with regard to secondary U deposits. Groundwater geochemistry in conjunction with palaeodrainage mapping may greatly improve exploration through cover where radiometric geophysics is not effective. The study of regional, shallow groundwater for U shows multiple benefits for mineral exploration, the economy and potable water quality.

Snow deposition and melt under different vegetative covers in central New York

Science.gov (United States)

A. R. Eschner; D. R. Satterlund

1963-01-01

Two-thirds of the annual runoff from watersheds in the Allegheny Plateau of central New York comes from the snow-or snow and rain that falls in December through April. Although the amounts of precipitation in this period are fairly uniform from year to year, the proportion that falls as snow varies; so does the amount that accumulates on the ground, and its duration...

Electron Acceleration in the Field-reversed Configuration (FRC) by Slowly Rotation Odd-parity Magnetic Fields (RMFo)

International Nuclear Information System (INIS)

Glasser, A.H.; Cohen, S.A.

2001-01-01

The trajectories of individual electrons are studied numerically in a 3D, prolate, FRC [field-reversed configuration] equilibrium magnetic geometry with added small-amplitude, slowly rotating, odd-parity magnetic fields (RMFos). RMFos cause electron heating by toroidal acceleration near the O-point line and by field-parallel acceleration away from it, both followed by scattering from magnetic-field inhomogeneities. Electrons accelerated along the O-point line move antiparallel to the FRC's current and attain average toroidal angular speeds near that of the RMFo, independent of the sense of RMFo rotation. A conserved transformed Hamiltonian, dependent on electron energy and RMFo sense, controls electron flux-surface coordinate

A CADASIL-Like Case with a Novel Noncysteine Mutation of the NOTCH3 Gene and Granular Deposits in the Renal Arterioles

Directory of Open Access Journals (Sweden)

Kuniyuki Nakamura

2015-01-01

Full Text Available We herein report the finding of a 62-year-old male, who developed dysarthria and dysphagia, with cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy- (CADASIL- like cerebral lesions. He also suffered from slowly progressive renal failure with the findings of granular deposits similar to electron-dense granular osmiophilic material in the renal arterioles. We found a novel heterozygous missense mutation of the NOTCH3 gene, c.4039G>C in exon 24, resulting in a p.Gly1347Arg substitution in its extracellular domain. The noncysteine substitution may underlie the pathogenesis of white matter lesions in the brain and of the chronic renal failure in the present case.

26 CFR 1.895-1 - Income derived by a foreign central bank of issue, or by Bank for International Settlements, from...

Science.gov (United States)

2010-04-01

... 26 Internal Revenue 9 2010-04-01 2010-04-01 false Income derived by a foreign central bank of... foreign central bank of issue, or by Bank for International Settlements, from obligations of the United States or from bank deposits. (a) In general. Income derived by a foreign central bank of issue from...

EFFECT OF CENTRAL FANS AND IN-DUCT FILTERS ON DEPOSITION RATES OF ULTRAFINE AND FINE PARTICLES IN AN OCCUPIED TOWNHOUSE

Science.gov (United States)

Airborne particles are implicated in morbidity and mortality of certain high-risk subpopulations. Exposure to particles occurs mostly indoors, where a main removal mechanism is deposition to surfaces. Deposition can be affected by the use of forced- air circulation through duct...

Middle Holocene avulsion-belt deposits in the central Rhine-Meuse delta, the Netherlands

NARCIS (Netherlands)

Makaske, B.; Berendsen, H.J.A.; Ree, M.H.M.

2007-01-01

The Schoonrewoerd fluvial system in the central Rhine¿Meuse delta was active as a Rhine distributary between 3900 and 3800 14C years BP. Based on planform patterns, cross-sectional facies architecture, reconstructed paleodischarge, and its short period of activity, the Schoonrewoerd fluvial system

Origin of silicic magmas along the Central American volcanic front: Genetic relationship to mafic melts

Science.gov (United States)

Vogel, Thomas A.; Patino, Lina C.; Eaton, Jonathon K.; Valley, John W.; Rose, William I.; Alvarado, Guillermo E.; Viray, Ela L.

2006-09-01

Silicic pyroclastic flows and related deposits are abundant along the Central American volcanic front. These silicic magmas erupted through both the non-continental Chorotega block to the southeast and the Paleozoic continental Chortis block to the northwest. The along-arc variations of the silicic deposits with respect to diagnostic trace element ratios (Ba/La, U/Th, Ce/Pb), oxygen isotopes, Nd and Sr isotope ratios mimic the along-arc variation in the basaltic and andesitic lavas. This variation in the lavas has been interpreted to indicate relative contributions from the slab and asthenosphere to the basaltic magmas [Carr, M.J., Feigenson, M.D., Bennett, E.A., 1990. Incompatible element and isotopic evidence for tectonic control of source mixing and melt extraction along the Central American arc. Contributions to Mineralogy and Petrology, 105, 369-380.; Patino, L.C., Carr, M.J. and Feigenson, M.D., 2000. Local and regional variations in Central American arc lavas controlled by variations in subducted sediment input. Contributions to Mineralogy and Petrology, 138 (3), 265-283.]. With respect to along-arc trends in basaltic lavas the largest contribution of slab fluids is in Nicaragua and the smallest input from the slab is in central Costa Rica — similar trends are observed in the silicic pyroclastic deposits. Data from melting experiments of primitive basalts and basaltic andesites demonstrate that it is difficult to produce high K 2O/Na 2O silicic magmas by fractional crystallization or partial melting of low-K 2O/Na 2O sources. However fractional crystallization or partial melting of medium- to high-K basalts can produce these silicic magmas. We interpret that the high-silica magmas associated Central America volcanic front are partial melts of penecontemporaneous, mantle-derived, evolved magmas that have ponded and crystallized in the mid-crust — or are melts extracted from these nearly completely crystallized magmas.

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

Full Text Available The geometry, stratigraphy, tectonics and volcanic components of the borate bearing Neogene basins in western Anatolia offer some important insights into on the relationship between basin evolution, borate formation and mode of extension in western Anatolia. Some of the borate deposits in NE-SW trending basins developed along the İzmir-Balıkesir Transfer Zone (İBTZ (e.g. Bigadiç, Sultançayır and Kestelek basins, and other deposits in the NE-SW trending basins which occur on the northern side of the Menderes Core Complex (MCC are the Selendi and Emet basins. The Kırka borate deposit occurs further to the east and is located in a completely different geological setting and volcanostratigraphic succession. Boron is widely distributed; including in soil and water, plants and animals. The element boron does not exist freely by itself in nature, but rather it occurs in combination with oxygen and other elements in salts, commonly known as borates. Approximately 280 boron-bearing minerals have been identified, the most common being sodium, calcium and magnesium salts. Four main continental metallogenic borate provinces are recognized at a global scale. They are located in Anatolia (Turkey, California (USA, Central Andes (South America and Tibet (Central Asia. The origin of borate deposits is related to Cenozoic volcanism, thermal spring activity, closed basins and arid climate. Borax is the major commercial source of boron, with major supplies coming from Turkey, USA and Argentina. Colemanite is the main calcium borate and large scale production is restricted to Turkey. Datolite and szaibelyite are confined to Russia and Chinese sources. Four Main borax (tincal deposits are present in Anatolia (Kırka, California (Boron, and two in the Andes (Tincalayu and Loma Blanca. Kırka, Boron and Loma Blanca have similarities with regard to their chemical and mineralogical composition of the borate minerals. Colemanite deposits with/without probertite and

DEPOSITIONAL ARCHITECTURE, FACIES CHARACTER AND GEOCHEMICAL SIGNATURE OF THE TIVOLI TRAVERTINES (PLEISTOCENE, ACQUE ALBULE BASIN, CENTRAL ITALY

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GIOVANNA DELLA PORTA

2017-08-01

Full Text Available Facies character, diagenesis, geochemical signature, porosity, permeability, and geometry of the upper Pleistocene Tivoli travertines were investigated integrating information from six borehole cores, drilled along a 3 km N-S transect, and quarry faces, in order to propose a revised depositional model. Travertines overlie lacustrine and alluvial plain marls, siltstones, sandstones and pyroclastic deposits from the Roman volcanic districts. In the northern proximal area, with respect to the inferred hydrothermal vents, travertines accumulated in gently-dipping, decametre-scale shallow pools of low-angle terraced slopes. The intermediate depositional zone, 2 km southward, consisted of smooth and terraced slopes dipping S and E. In the southernmost distal zone, travertine marshes dominated by coated vegetation and Charophytes interfingered with lacustrine siltstones and fluvial sandstones and conglomerates. Travertine carbon and oxygen stable isotope data confirm the geothermal origin of the precipitating spring water. The travertine succession is marked by numerous intraclastic/extraclastic wackestone to rudstone beds indicative of non-deposition and erosion during subaerial exposure, due to temporary interruption of the vent activity or deviation of the thermal water flow. These unconformities identify nine superimposed travertine units characterized by aggradation in the proximal zone and southward progradation in the intermediate to distal zones. The wedge geometry of the travertine system reflects the vertical and lateral superimposition of individual fan-shaped units in response to changes in the vent location, shifting through time to lower elevations southward. The complexity of the travertine architecture results from the intermittent activity of the vents, their locations, the topographic gradient, thermal water flow paths and the rates and modes of carbonate precipitation.

Augmented brain function by coordinated reset stimulation with slowly varying sequences

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Magteld eZeitler

2015-03-01

Full Text Available Several brain disorders are characterized by abnormally strong neuronal synchrony. Coordinated Reset (CR stimulation was developed to selectively counteract abnormal neuronal synchrony by desynchronization. For this, phase resetting stimuli are delivered to different subpopulations in a timely coordinated way. In neural networks with spike timing-dependent plasticity CR stimulation may eventually lead to an anti-kindling, i.e. an unlearning of abnormal synaptic connectivity and abnormal synchrony. The spatiotemporal sequence by which all stimulation sites are stimulated exactly once is called the stimulation site sequence, or briefly sequence. So far, in simulations, pre-clinical and clinical applications CR was applied either with fixed sequences or rapidly varying sequences (RVS. In this computational study we show that appropriate repetition of the sequence with occasional random switching to the next sequence may significantly improve the anti-kindling effect of CR. To this end, a sequence is applied many times before randomly switching to the next sequence. This new method is called SVS CR stimulation, i.e. CR with slowly varying sequences. In a neuronal network with strong short-range excitatory and weak long-range inhibitory dynamic couplings SVS CR stimulation turns out to be superior to CR stimulation with fixed sequences or RVS.

Augmented brain function by coordinated reset stimulation with slowly varying sequences.

Science.gov (United States)

Zeitler, Magteld; Tass, Peter A

2015-01-01

Several brain disorders are characterized by abnormally strong neuronal synchrony. Coordinated Reset (CR) stimulation was developed to selectively counteract abnormal neuronal synchrony by desynchronization. For this, phase resetting stimuli are delivered to different subpopulations in a timely coordinated way. In neural networks with spike timing-dependent plasticity CR stimulation may eventually lead to an anti-kindling, i.e., an unlearning of abnormal synaptic connectivity and abnormal synchrony. The spatiotemporal sequence by which all stimulation sites are stimulated exactly once is called the stimulation site sequence, or briefly sequence. So far, in simulations, pre-clinical and clinical applications CR was applied either with fixed sequences or rapidly varying sequences (RVS). In this computational study we show that appropriate repetition of the sequence with occasional random switching to the next sequence may significantly improve the anti-kindling effect of CR. To this end, a sequence is applied many times before randomly switching to the next sequence. This new method is called SVS CR stimulation, i.e., CR with slowly varying sequences. In a neuronal network with strong short-range excitatory and weak long-range inhibitory dynamic couplings SVS CR stimulation turns out to be superior to CR stimulation with fixed sequences or RVS.

THE ACTIVITIES OF THE NATIONAL BANK OF UKRAINE ON THE OPEN MARKET: OPERATION WITH CERTIFICATES OF DEPOSITS

Directory of Open Access Journals (Sweden)

Yuliia Harkusha

2016-06-01

Full Text Available In the article investigated the activities of the National Bank of Ukraine on the open market. The analysis of operations of the National Bank of Ukraine banks to raise funds placing deposit certificates. Defined impact operations of the central bank's own debt securities to trading volumes deposit certificates of the National Bank of Ukraine on the stock market and the credit activity of banks. Identified problems interest rate policy and the ways to overcome them. Key words: National Bank of Ukraine, certificates of deposits, open market, interest rate policy, banks, stock exchange. JEL: E 58

Long-term contraction of pyroclastic flow deposits at Augustine Volcano using InSAR

Science.gov (United States)

McAlpin, D. B.; Meyer, F. J.; Lu, Z.; Beget, J. E.

2013-12-01

Augustine Island is a small, 8x11 km island in South Central Alaska's lower Cook Inlet. It is approximately 280 km southwest of Anchorage, and occupied entirely by its namesake Augustine Volcano. The volcano's nearly symmetrical central cone reaches an altitude of 1260 m, and the surrounding island is composed almost entirely of volcanic deposits. It is the youngest and most frequently active volcano in the lower Cook Inlet, with at least seven known eruptions since the beginning of written records in 1812. Its two most recent eruptions occurred during March-August 1986, and January-March 2006 The 1986 and 2006 Augustine eruptions produced significant pyroclastic flow deposits (PFDs) on the island, both which have been well mapped by previous studies. Subsidence of material deposited by these pyroclastic flows has been measured by InSAR data, and can be attributed to at least four processes: (1) initial, granular settling; (2) thermal contraction; (3) loading of 1986 PFDs from overlying 2006 deposits; and (4) continuing subsidence of 1986 PFDs buried beneath 2006 flows. For this paper, SAR data for PFDs from Augustine Volcano were obtained from 1992 through 2005, from 2006-2007, and from 2007-2011. These time frames provided InSAR data for long-term periods after both 1986 and 2006 eruptions. From time-series analysis of these datasets, deformation rates of 1986 PFDs and 2006 PFDs were determined, and corrections applied where newer deposits were emplaced over old deposits. The combination of data sets analyzed in this study enabled, for the first time, an analysis of long and short term subsidence rates of volcanic deposits emplaced by the two eruptive episodes. The generated deformation time series provides insight into the significance and duration of the initial settling period and allows us to study the thermal regime and heat loss of the PFDs. To extract quantitative information about thermal properties and composition of the PFDs, we measured the thickness

Abrupt climatic events recorded by the Ili loess during the last glaciation in Central Asia: Evidence from grain-size and minerals

Science.gov (United States)

Song, Yougui; Zeng, Mengxiu; Chen, Xiuling; Li, Yue; Chang, Hong; An, Zhisheng; Guo, Xiaohua

2018-04-01

The loess record of Central Asia provides an important archive of regional climate and environmental changes. In contrast to the widely investigated loess deposits in the Chinese Loess Plateau, Central Asian loess-paleosol sequences remain poorly understood. Here, we present an aeolian loess section in the southern Ili Basin. Based on granularity and mineralogical analyses, we reconstruct climatic changes during the last glaciation. The results indicated that most of the abrupt climatic events (such as Dansgaard-Oeschger events and Heinrich events) were imprinted in this loess section, although their amplitudes and ages showed some differences. Compared with the millennial oscillations recoded in loess and stalagmites in East Asia, the arid Central Asia responded more sensitively to the warming events than to the cooling events. The shifting trajectory of westerlies across Central Asia played an important role in dust deposition during the stadials. The North Atlantic climatic signals may have been transmitted from Central Asia to the East Asian monsoon regions via the westerlies.

A Systematic Analysis of the Sensitivity of Plasma Pharmacokinetics to Detect Differences in the Pulmonary Performance of Inhaled Fluticasone Propionate Products Using a Model-Based Simulation Approach.

Science.gov (United States)

Weber, Benjamin; Hochhaus, Guenther

2015-07-01

The role of plasma pharmacokinetics (PK) for assessing bioequivalence at the target site, the lung, for orally inhaled drugs remains unclear. A validated semi-mechanistic model, considering the presence of mucociliary clearance in central lung regions, was expanded for quantifying the sensitivity of PK studies in detecting differences in the pulmonary performance (total lung deposition, central-to-peripheral lung deposition ratio, and pulmonary dissolution characteristics) between test (T) and reference (R) inhaled fluticasone propionate (FP) products. PK bioequivalence trials for inhaled FP were simulated based on this PK model for a varying number of subjects and T products. The statistical power to conclude bioequivalence when T and R products are identical was demonstrated to be 90% for approximately 50 subjects. Furthermore, the simulations demonstrated that PK metrics (area under the concentration time curve (AUC) and C max) are capable of detecting differences between T and R formulations of inhaled FP products when the products differ by more than 20%, 30%, and 25% for total lung deposition, central-to-peripheral lung deposition ratio, and pulmonary dissolution characteristics, respectively. These results were derived using a rather conservative risk assessment approach with an error rate of <10%. The simulations thus indicated that PK studies might be a viable alternative to clinical studies comparing pulmonary efficacy biomarkers for slowly dissolving inhaled drugs. PK trials for pulmonary efficacy equivalence testing should be complemented by in vitro studies to avoid false positive bioequivalence assessments that are theoretically possible for some specific scenarios. Moreover, a user-friendly web application for simulating such PK equivalence trials with inhaled FP is provided.

Logs of Paleoseismic Excavations Across the Central Range Fault, Trinidad

Science.gov (United States)

Crosby, Christopher J.; Prentice, Carol S.; Weber, John; Ragona, Daniel

2009-01-01

This publication makes available maps and trench logs associated with studies of the Central Range Fault, part of the South American-Caribbean plate boundary in Trinidad. Our studies were conducted in 2001 and 2002. We mapped geomorphic features indicative of active faulting along the right-lateral, Central Range Fault, part of the South American-Caribbean plate boundary in Trinidad. We excavated trenches at two sites, the Samlalsingh and Tabaquite sites. At the Samlalsingh site, sediments deposited after the most recent fault movement bury the fault, and the exact location of the fault was unknown until we exposed it in our excavations. At this site, we excavated a total of eleven trenches, six of which exposed the fault. The trenches exposed fluvial sediments deposited over a strath terrace developed on Miocene bedrock units. We cleaned the walls of the excavations, gridded the walls with either 1 m X 1 m or 1 m X 0.5 m nail and string grid, and logged the walls in detail at a scale of 1:20. Additionally, we described the different sedimentary units in the field, incorporating these descriptions into our trench logs. We mapped the locations of the trenches using a tape and compass. Our field logs were scanned, and unit contacts were traced in Adobe Illustrator. The final drafted logs of all the trenches are presented here, along with photographs showing important relations among faults and Holocene sedimentary deposits. Logs of south walls were reversed in Illustrator, so that all logs are drafted with the view direction to the north. We collected samples of various materials exposed in the trench walls, including charcoal samples for radiocarbon dating from both faulted and unfaulted deposits. The locations of all samples collected are shown on the logs. The ages of seventeen of the charcoal samples submitted for radiocarbon analysis at the University of Arizona Accelerator Mass Spectrometry Laboratory in Tucson, Ariz., are given in Table 1. Samples found in

A 600-year-long stratigraphic record of tsunamis in south-central Chile

Science.gov (United States)

Hong, Isabel; Dura, Tina; Ely, Lisa L.; Horton, Benajamin P.; Nelson, Alan R.; Cisternas, Marco; Nikitina, Daria; Wesson, Robert L.

2017-01-01

The stratigraphy within coastal river valleys in south-central Chile clarifies and extends the region’s history of large, earthquakes and accompanying tsunamis. Our site at Quidico (38.1°S, 73.3°W) is located in an overlap zone between ruptures of magnitude 8–9 earthquakes in 1960 and 2010, and, therefore, records tsunamis originating from subduction-zone ruptures north and south of the city of Concepción. Hand-dug pits and cores in a 3-m-thick sequence of freshwater peat in an abandoned meander (a little-examined depositional environment for tsunami deposits) and exposures along the Quidico River show five sand beds that extend as much as 1.2 km inland. Evidence for deposition of the beds by tsunamis includes tabular sand beds that are laterally extensive (>100 m), well sorted, fine upward, have sharp lower contacts, and contain diatom assemblages dominated by brackish and marine taxa. Using eyewitness accounts of tsunami inundation, 137Cs analyses, and 14C dating, we matched the upper four sand beds with historical tsunamis in 2010, 1960, 1835, and 1751. The oldest prehistoric bed dates to 1445–1490 CE and correlates with lacustrine and coastal records of similar-aged earthquakes and tsunamis in south-central Chile.

Deposition of acidifying components and base cations in Germany in the period 1987-1995

International Nuclear Information System (INIS)

Bleeker, A.; Draaijers, G.P.J; Klap, J.M.; Van Jaarsveld, J.A.

2000-01-01

The title project was carried out on behalf of and for account of the 'Umweltbundesamt' (UBA) Germany in co-operation with TNO-MEP and SC-DLO. The main products arising from this project are, for Germany, estimates of dry deposition with a high spatial resolution, which, in combination with wet deposition data, will be used for the calculation of critical load exceedances. The basic model used in this study was EDACS. This model calculates dry deposition fluxes on the basis of meteorological data and atmospheric concentrations of relevant species. As such, the project reported here further elaborates the work carried out in a previous project in 1996, with the following additions and/or improvements worked out: (a) The distribution of NH3 concentrations in Germany has now been calculated on a 5x5 km grid using the EUTREND model, while in the previous study these data were taken from the standard EMEP model; (b) Possible concepts for introducing cloud deposition into the inferential approach have been investigated, with results for a small study area in southern Germany shown; (c) Canopy exchange estimates for forest sites in Germany were related to parameters, also measured at these sites to gain better insight into the parameters controlling canopy uptake and leaching. SOx dry deposition fluxes were highest in central-east Germany, NOy fluxes in central-west Germany and NHx fluxes in north-west Germany. The highest dry deposition of potential acid (up to 15,000 eq. ha -1 y -1 in 1987) was calculated for 'Bundesland' Sachsen and the highest dry deposition load of nitrogen was calculated for Bremen (up to 2100 eq ha -1 y -1 in 1989). Dry deposition of SOx, NOy, NHx and potential acid in the 1993-1995 period decreased by 36%, 13%, 21% and 31%, respectively, compared to the 1987-1989 period The decrease in potential acid was highest in Sachsen (43%) and lowest in Baden-Wittemberg (12%). Dry deposition of non-sea salt Ca 2+ , K + , Mg 2+ and base cations decreased

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...

Non-conventional photocathodes based on Cu thin films deposited on Y substrate by sputtering

Energy Technology Data Exchange (ETDEWEB)

Perrone, A. [Department of Mathematics and Physics “E. De Giorgi”, University of Salento, 73100 Lecce (Italy); National Institute of Nuclear Physics and University of Salento, 73100 Lecce (Italy); D’Elia, M. [Department of Mathematics and Physics “E. De Giorgi”, University of Salento, 73100 Lecce (Italy); Gontad, F., E-mail: francisco.gontad@le.infn.it [Department of Mathematics and Physics “E. De Giorgi”, University of Salento, 73100 Lecce (Italy); National Institute of Nuclear Physics and University of Salento, 73100 Lecce (Italy); Di Giulio, M.; Maruccio, G. [Department of Mathematics and Physics “E. De Giorgi”, University of Salento, 73100 Lecce (Italy); Cola, A. [National Council Research, Institute for Microelectronics and Microsystems, 73100 Lecce (Italy); Stankova, N.E. [Institute of Electronics, Bulgarian Academy of Sciences, 1784 Sofia (Bulgaria); Kovacheva, D.G. [Institute of General and Inorganic Chemistry, Bulgarian Academy of Sciences, 1113 Sofia (Bulgaria); Broitman, E. [Department of Physics, Chemistry and Biology (IFM), Linköping University, SE-581 83 Linköping (Sweden)

2014-07-01

Copper (Cu) thin films were deposited on yttrium (Y) substrate by sputtering. During the deposition, a small central area of the Y substrate was shielded to avoid the film deposition and was successively used to study its photoemissive properties. This configuration has two advantages: the cathode presents (i) the quantum efficiency and the work function of Y and (ii) high electrical compatibility when inserted into the conventional radio-frequency gun built with Cu bulk. The photocathode was investigated by scanning electron microscopy to determine surface morphology. X-ray diffraction and atomic force microscopy studies were performed to compare the structure and surface properties of the deposited film. The measured electrical resistivity value of the Cu film was similar to that of high purity Cu bulk. Film to substrate adhesion was also evaluated using the Daimler–Benz Rockwell-C adhesion test method. Finally, the photoelectron performance in terms of quantum efficiency was obtained in a high vacuum photodiode cell before and after laser cleaning procedures. A comparison with the results obtained with a twin sample prepared by pulsed laser deposition is presented and discussed.

Transformation and Deposition of Sulphur and Nitrogen Compounds in the Marine Boundary Layer

Energy Technology Data Exchange (ETDEWEB)

Hertel, O

1995-10-01

In this thesis the author performs a model study of the transformation and deposition of sulphur and nitrogen compounds in the marine boundary layer, including source-receptor relationships. The central part of the study is the development and testing of a variable scale trajectory model for Europe, with special emphasis on modelling the concentrations of gases and aerosols in the marine atmosphere and the deposition to sea. A one-dimensional version of the model was developed to model the chemical degradation of dimethyl sulphide (DMS) in the marine boundary layer. Although the model reproduces the observed levels of DMS and methane sulphonic acid (MSA) well, the calculated DMS concentration is not always in phase with observed levels, probably because of a local coastal emission that is correlated with the shifting tide. Another version of the trajectory model, Atmospheric Chemistry and Deposition model (ACDEP), was developed to study the deposition of nitrogen compounds to the Danish sea waters. This model uses a new numerical scheme, the Eulerian Backward Iterative method. The model is able to reproduce observations of air concentrations and wet deposition fairly well; data for dry deposition were not available. The model was also used for calculation of deposition of nitrogen compounds to the Kattegat. Finally, a sensitivity study was performed on the model. 175 refs., 87 figs., 32 tabs.

Uranium deposits of Lagoa Real uranium Province, state of Bahia, Brazil

International Nuclear Information System (INIS)

Ribeiro, C.I.; Carvalho Filho, C.A. de; Hashizume, B.K.

1984-01-01

The Uranium Province of Lagoa Real is situated in the south-central part of the state of Bahia and constitutes, at the present moment, one of the most promising uranium districts of Brazil. The first anomaly was recorded in 1977 and, since then intense exploration and evaluation has been carried out in the area, resulting in the characterization of six ore deposits until now. Simultaneously, NUCLEBRAS has performed tests to establish the beneficiation characteristics of the ore, and developed preliminary mining plans. The host rock for the ore mineralization is related to sodic metasomatism and controlled by lithology and structure. The ore exhibits granoblastic texture, fine to coarse grain size, and the principal uranium minerals are uraninite, and, in minor quantities, pitchblende and uranophane. The solubility is over 90% of the U 3 O 8 contained, with an average acid consumption of 35 Kg per ton of ore treated. This paper presents a brief description of the main ore deposits and touches on their general characterisitcs. As an example, the deposit 'Jazida Cachoeira' is dealt with in greater detail, since this deposit is considered in the present context to be the most important one in the province. (Author) [pt

Atmospheric nitrogen deposition in the Yangtze River basin: Spatial pattern and source attribution.

Science.gov (United States)

Xu, Wen; Zhao, Yuanhong; Liu, Xuejun; Dore, Anthony J; Zhang, Lin; Liu, Lei; Cheng, Miaomiao

2018-01-01

The Yangtze River basin is one of the world's hotspots for nitrogen (N) deposition and likely plays an important role in China's riverine N output. Here we constructed a basin-scale total dissolved inorganic N (DIN) deposition (bulk plus dry) pattern based on published data at 100 observational sites between 2000 and 2014, and assessed the relative contributions of different reactive N (N r ) emission sectors to total DIN deposition using the GEOS-Chem model. Our results show a significant spatial variation in total DIN deposition across the Yangtze River basin (33.2 kg N ha -1 yr -1 on average), with the highest fluxes occurring mainly in the central basin (e.g., Sichuan, Hubei and Hunan provinces, and Chongqing municipality). This indicates that controlling N deposition should build on mitigation strategies according to local conditions, namely, implementation of stricter control of N r emissions in N deposition hotspots but moderate control in the areas with low N deposition levels. Total DIN deposition in approximately 82% of the basin area exceeded the critical load of N deposition for semi-natural ecosystems along the basin. On the basin scale, the dominant source of DIN deposition is fertilizer use (40%) relative to livestock (11%), industry (13%), power plant (9%), transportation (9%), and others (18%, which is the sum of contributions from human waste, residential activities, soil, lighting and biomass burning), suggesting that reducing NH 3 emissions from improper fertilizer (including chemical and organic fertilizer) application should be a priority in curbing N deposition. This, together with distinct spatial variations in emission sector contributions to total DIN deposition also suggest that, in addition to fertilizer, major emission sectors in different regions of the basin should be considered when developing synergistic control measures. Copyright © 2017. Published by Elsevier Ltd.

Phenolic acids as bioindicators of fly ash deposit revegetation

Energy Technology Data Exchange (ETDEWEB)

L. Djurdjevic; M. Mitrovic; P. Pavlovic; G. Gajic; O. Kostic [Institute for Biological Research ' Sinisa Stankovic,' Belgrade (Serbia and Montenegro). Department of Ecology

2006-05-15

The floristic composition, the abundance, and the cover of pioneer plant species of spontaneously formed plant communities and the content of total phenolics and phenolic acids, as humus constituents, of an ash deposit after 7 years of recultivation were studied. The restoration of both the soil and the vegetation on the ash deposits of the 'Nikola Tesla-A' thermoelectric power plant in Obrenovac (Serbia) is an extremely slow process. Unfavorable physical and chemical characteristics, the toxicity of fly ash, and extreme microclimatic conditions prevented the development of compact plant cover. The abundance and cover of plants increased from the central part of the deposit towards its edges. Festuca rubra L., Crepis setosa Hall., Erigeron canadensis L., Cirsium arvense (L.) Scop., Calamagrostis epigeios (L.) Roth., and Tamarix gallica L. were the most abundant species, thus giving the highest cover. Humus generated during the decomposition process of plant remains represents a completely new product absent in the ash as the starting material. The amount of total phenolics and phenolic acids in fly ash increased from the center of the deposit towards its edges in correlation with the increase in plant abundance and cover. The presence of phenolic acids indicates the ongoing process of humus formation in the ash, in which the most abundant pioneer plants of spontaneously formed plant communities play the main role. Phenolic compounds can serve as reliable bioindicators in an assessment of the success of the recultivation process of thermoelectric power plants' ash deposits.

Age and tectonomagmatic setting of the Eocene Çöpler-Kabataş magmatic complex and porphyry-epithermal Au deposit, East Central Anatolia, Turkey

Science.gov (United States)

İmer, Ali; Richards, Jeremy P.; Creaser, Robert A.

2013-06-01

The Çöpler epithermal Au deposit and related subeconomic porphyry Cu-Au deposit is hosted by the middle Eocene Çöpler-Kabataş magmatic complex in central eastern Anatolia. The intrusive rocks of the complex were emplaced into Late Paleozoic-Mesozoic metamorphosed sedimentary basement rocks near the northeastern margin of the Tauride-Anatolide Block. Igneous biotite from two samples of the magmatic complex yielded 40Ar/39Ar plateau ages of 43.75 ± 0.26 Ma and 44.19 ± 0.23, whereas igneous hornblende from a third sample yielded a plateau age of 44.13 ± 0.38. These ages closely overlap with 40Ar/39Ar ages of hydrothermal sericite (44.44 ± 0.28 Ma) and biotite (43.84 ± 0.26 Ma), and Re-Os ages from two molybdenite samples (44.6 ± 0.2 and 43.9 ± 0.2 Ma) suggesting a short-lived (history at Çöpler. No suitable minerals were found that could be used to date the epithermal system, but it is inferred to be close in age to the precursor porphyry system. The Çöpler-Kabataş intrusive rocks show I-type calc-alkaline affinities. Their normalized trace element patterns show enrichments in large ion lithophile and light rare earth elements and relative depletions in middle and heavy rare earth elements, resembling magmas generated in convergent margins. However, given its distance from the coeval Eocene Maden-Helete volcanic arc, the complex is interpreted to be formed in a back-arc setting, in response to Paleocene slab roll-back and upper-plate extension. The tectonomagmatic environment of porphyry-epithermal mineralization at Çöpler is comparable to some other isolated back-arc porphyry systems such as Bajo de la Alumbrera (Argentina) or Bingham Canyon (USA).

Early diagenesis of recently deposited organic matter: A 9-yr time-series study of a flood deposit

Science.gov (United States)

Tesi, T.; Langone, L.; Goñi, M. A.; Wheatcroft, R. A.; Miserocchi, S.; Bertotti, L.

2012-04-01

In Fall 2000, the Po River (Italy) experienced a 100-yr return period flood that resulted in a 1-25 cm-thick deposit in the adjacent prodelta (10-25 m water depth). In the following years, numerous post-depositional perturbations occurred including bioturbation, reworking by waves with heights exceeding 5 m, as well as periods of extremely high and low sediment supply. Cores collected in the central prodelta after the Fall 2000 flood and over the following 9 yr, allowed characterization of the event-strata in their initial state and documentation of their subsequent evolution. Sedimentological characteristics were investigated using X-radiographs and sediment texture analyses, whereas the composition of sedimentary organic matter (OM) was studied via bulk and biomarker analyses, including organic carbon (OC), total nitrogen (TN), carbon stable isotope composition (δ13C), lignin phenols, cutin-products, p-hydroxy benzenes, benzoic acids, dicarboxylic acids, and fatty acids. The 9-yr time-series analysis indicated that roughly the lower half of the original event bed was preserved in the sediment record. Conversely, the upper half of the deposit experienced significant alterations including bioturbation, addition of new material, as well as coarsening. Comparison of the recently deposited material with 9-yr old preserved strata represented a unique natural laboratory to investigate the diagenesis of sedimentary OM in a non-steady system. Bulk data indicated that OC and TN were degraded at similar rates (loss ∼17%) whereas biomarkers exhibited a broad spectrum of reactivities (loss from ∼6% to ∼60%) indicating selective preservation during early diagenesis. Given the relevance of episodic sedimentation in several margins, this study has demonstrated the utility of event-response and time-series sampling of the seabed for understanding the early diagenesis in non-steady conditions.

Origin and chemical composition of evaporite deposits

Science.gov (United States)

Moore, George William

1960-01-01

A comparative study of marine evaporite deposits forming at the present time along the pacific coast of central Mexico and evaporite formations of Permian age in West Texas Basin was made in order to determine if the modern sediments provide a basis for understanding environmental conditions that existed during deposition of the older deposits. The field work was supplemented by investigations of artificial evaporite minerals precipitated in the laboratory and by study of the chemical composition of halite rock of different geologic ages. The environment of deposition of contemporaneous marine salt deposits in Mexico is acidic, is strongly reducing a few centimeters below the surface, and teems with microscopic life. Deposition of salt, unlike that of many other sediments, is not wholly a constructional phenomenon. Permanent deposits result only if a favorable balance exists between deposition in the dry season and dissolution in the wet season. Evaporite formations chosen for special study in the West Texas Basin are, in ascending order, the Castile, Salado, and Rustler formations, which have a combined thickness of 1200 meters. The Castile formation is largely composed of gypsum rock, the Salado, halite rock, and the Rustler, quartz and carbonate sandstone. The lower part of the Castile formation is bituminous and contains limestone laminae. The Castile and Rustler formations thicken to the south at the expense of salt of the intervening Salado formation. The clastic rocks of the Rustler formation are interpreted as the deposits of a series of barrier islands north of which halite rock of the Salado was deposited. The salt is believed to have formed in shallow water of uniform density that was mixed by the wind. Where water depth exceeded the depth of the wind mixing, density stratification developed, and gypsum was deposited. Dense water of high salinity below the density discontinuity was overlain by less dense, more normally saline water which was derived from

Examination of Surface Deposits on Oldbury Reactor Core Graphite to Determine the Concentration and Distribution of 14C.

Directory of Open Access Journals (Sweden)

Liam Payne

Full Text Available Pile Grade A graphite was used as a moderator and reflector material in the first generation of UK Magnox nuclear power reactors. As all of these reactors are now shut down there is a need to examine the concentration and distribution of long lived radioisotopes, such as 14C, to aid in understanding their behaviour in a geological disposal facility. A selection of irradiated graphite samples from Oldbury reactor one were examined where it was observed that Raman spectroscopy can distinguish between underlying graphite and a surface deposit found on exposed channel wall surfaces. The concentration of 14C in this deposit was examined by sequentially oxidising the graphite samples in air at low temperatures (450°C and 600°C to remove the deposit and then the underlying graphite. The gases produced were captured in a series of bubbler solutions that were analysed using liquid scintillation counting. It was observed that the surface deposit was relatively enriched with 14C, with samples originating lower in the reactor exhibiting a higher concentration of 14C. Oxidation at 600°C showed that the remaining graphite material consisted of two fractions of 14C, a surface associated fraction and a graphite lattice associated fraction. The results presented correlate well with previous studies on irradiated graphite that suggest there are up to three fractions of 14C; a readily releasable fraction (corresponding to that removed by oxidation at 450°C in this study, a slowly releasable fraction (removed early at 600°C in this study, and an unreleasable fraction (removed later at 600°C in this study.

Stability of radioactive minerals in an oxidizing hydrogeological environment: new results from an alluvial placer deposit, Naegi district, central Japan

International Nuclear Information System (INIS)

Sasao, Eiji; Komuro, Kosei; Nakata, Masataka

2009-01-01

Study of the stability of radioactive minerals in a placer deposit in the Naegi District, southeastern Gifu Prefecture, Central Japan contributes to understanding the modes of nuclide migration under various hydrogeological environments in the tectonically active Japanese Island Arc system. The placer deposit is embedded in basal conglomerates of the lower-most alluvial sequences, exposed to a near-surface, oxidizing hydrogeological environment. The mineral samples, ranging in mesh size from 120 to 250, were identified after sieving and magnetic separation to be mainly cassiterite, thorite, monazite, and topaz, with subordinate amounts of zircon, fergusonite-(Y), xenotime and wolframite. Observations using optical and scanning microscopy indicated that many grains of zircon have well-preserved crystal faces. Most monazite and fergusonite-(Y) grains are partly abraded and corroded whereas thorite grains are highly abraded and corroded. This indicates that under an oxidizing hydrogeological environment, the mechanical durability and geological stability decrease from zircon to monazite/fergusonite-(Y) to thorite, which correlates well with the Mohs's hardness scale. Cut and polished thorite grains display a high degree of alteration. The altered portions have higher Th, Fe and Y contents, and lower U and Si contents in comparison with the unaltered portions, indicating leaching of U and Si. In the fergusonite-(Y) grains, the altered portions have higher Th, Nb and Ta contents, and lower U and Y contents in comparison with the unaltered portions, indicate leaching of U and Y. Thus it is determined that uranium is strongly leached in an oxidizing hydrogeological environment. The leaching behaviour is dependent on mineralogy and is consistent with thermodynamic estimates. The alteration rate of fergusonite-(Y) was calculated to range from 0.05 to 0.000025 μm/year based on the thickness of the external alteration film and the duration of exposure to the oxidizing

Benthic environmental baseline investigations in the manganese nodule area of the central Indian Basin

Digital Repository Service at National Institute of Oceanography (India)

Sharma, R.; Nath, B.N.; Gupta, S.M.; Ansari, Z.A.

In order to exploit the manganese nodule deposits in future, an assessment of the environmental impact due to potential mining activity, has been undertaken in the Central Indian Basin Under this programme, seabed surveys in five selected areas have...

Critical Factors Controlling Pd and Pt Potential in Porphyry Cu–Au Deposits: Evidence from the Balkan Peninsula

Directory of Open Access Journals (Sweden)

Demetrios G. Eliopoulos

2014-03-01

Full Text Available Porphyry Cu–Au–Pd±Pt deposits are significant Au resources, but their Pd and Pt potential is still unknown. Elevated Pd, Pt (hundreds of ppb and Au contents are associated with typical stockwork magnetite-bornite-chalcopyrite assemblages, at the central parts of certain porphyry deposits. Unexpected high grade Cu–(Pd+Pt (up to 6 ppm mineralization with high Pd/Pt ratios at the Elatsite porphyry deposit, which is found in a spatial association with the Chelopech epithermal deposit (Bulgaria and the Skouries porphyry deposit, may have formed during late stages of an evolved hydrothermal system. Estimated Pd, Pt and Au potential for porphyry deposits is consistent with literature model calculations demonstrating the capacity of aqueous vapor and brine to scavenge sufficient quantities of Pt and Pd, and could contribute to the global platinum-group element (PGE production. Critical requirements controlling potential of porphyry deposits may be from the metals contained in magma (metasomatized asthenospheric mantle wedge as indicated by significant Cr, Co, Ni and Re contents. The Cr content may be an indicator for the mantle input.

Relict Forms of a Disappeared Mountain. The Periglacial Deposits in Asinara Island-Sardinia, Italy

Directory of Open Access Journals (Sweden)

Sergio GINESU

2014-10-01

Full Text Available Asinara Island is located in northwestern Sardinia (Italy and only recently has been divested as a maximum-security prison and returned to nature protection as a National Park with Marine Protected Area along the coastal perimeter. Geologically, the island is formed by a Paleozoic basement in transition between the metamorphic rocks and the Pre-Hercynian granitic batholith of Sardinia. New surveys carried out to reconstruct the recent evolution of the landscape have shown a lot of deposits formed by large blocks of granitoid and anphibolitic rocks representing a favorable situation to produce this material formation in terms of differential erosion in periglaciar environment. Similar morphologies are possible to observe in many places in Sardinia continental hard rocks as effect of the conditions of refreezing periods ("glacial". These deposits are commonly known as " block streams " or " block fields " and reported for the first time in Italy in 1990 in the central area of the island of Sardinia, about 500 meters above sea level. Their presence in Sardinia is always documented in a range of altitudes not less than 350-400 meters and, in this case for the first time they have been identified in close proximity to the coastline. In addition, some of these deposits cover the thalwegs present on the granite rocks in the central portion of the island. The most interesting cases are represented by the deposits located on the northwestern side, near the lighthouse of Punta Scorno. The widespread presence of these deposits suggests significant areal erosion of the island terrain; they probably accumulated during the colder episodes that have characterized the Middle and Upper Pleistocene of the entire western Mediterranean. These testify the existence of an energy relief higher than the present one and a coastline located about 25 kilometers from the current position, however, documented by the block stream of Cala Arena, the first deposit located for

External quality-assurance project report for the National Atmospheric Deposition Program/National Trends Network and Mercury Deposition Network, 2009-2010

Science.gov (United States)

Wetherbee, Gregory A.; Martin, RoseAnn; Rhodes, Mark F.; Chesney, Tanya A.

2014-01-01

The U.S. Geological Survey operated six distinct programs to provide external quality-assurance monitoring for the National Atmospheric Deposition Program/National Trends Network (NTN) and Mercury Deposition Network (MDN) during 2009–2010. The field-audit program assessed the effects of onsite exposure, sample handling, and shipping on the chemistry of NTN samples; a system-blank program assessed the same effects for MDN. Two interlaboratory-comparison programs assessed the bias and variability of the chemical analysis data from the Central Analytical Laboratory (CAL) and Mercury (Hg) Analytical Laboratory (HAL). The blind-audit program was also implemented for the MDN to evaluate analytical bias in total Hg concentration data produced by the HAL. The co-located-sampler program was used to identify and quantify potential shifts in NADP data resulting from replacement of original network instrumentation with new electronic recording rain gages (E-gages) and precipitation collectors that use optical sensors. The results indicate that NADP data continue to be of sufficient quality for the analysis of spatial distributions and time trends of chemical constituents in wet deposition across the United States. Results also suggest that retrofit of the NADP networks with the new precipitation collectors could cause –8 to +14 percent shifts in NADP annual precipitation-weighted mean concentrations and total deposition values for ammonium, nitrate, sulfate, and hydrogen ion, and larger shifts (+13 to +74 percent) for calcium, magnesium, sodium, potassium, and chloride. The prototype N-CON Systems bucket collector is more efficient in the catch of precipitation in winter than Aerochem Metrics Model 301 collector, especially for light snowfall.

Gypsum ground: a new occurrence of gypsum sediment in playas of central Australia

Science.gov (United States)

Xiang Yang Chen; Bowler, James M.; Magee, John W.

1991-06-01

There are many playas (dry salt lakes) in arid central Australia (regional rainfall about 250 mm/y and pan evaporation around 3000 mm/y). Highly soluble salts, such as halite, only appear as a thin (several centimetres thick), white, ephemeral efflorescent crust on the dry surface. Gypsum is the major evaporite precipitating both at present and preserved in sediment sequences. One type of gypsum deposit forms a distinctive surface feature, which is here termed "gypsum ground". It consists of a thick (up to 80 cm) gypsum zone which rises from the surrounding smooth white playa surface and is overlain by a heaved brown crust. The gypsum zone, with an average gypsum content above 60%, consists of pure gypsum sublayers and interlayered clastic bands of sandy clay. The gypsum crystals are highly corroded, especially in the direction parallel to the c-axis and on the upper sides where illuviated clay has accumulated in corrosion hollows. Overgrowth parallel to the a- and b-axes is very common, forming highly discoidal habits. These secondary changes (corrosion and overgrowth) are well-developed in the vadose zone and absent from crystals below the long-term watertable (depth around 40 cm). These crystal characteristics indicate a rainwater leaching process. At Lake Amadeus, one of the largest playas (800 km 2) of central Australia, such gypsum ground occupies 16% of the total area. The gypsum ground is interpreted as an alteration of a pre-existing gypsum deposit which probably extended across the whole playa before breaking down, leaving a playa marginal terrace and several terrace islands within the gypsum ground. This pre-existing gypsum deposit, preserved in the residual islands, consists of pure, pale, sand-sized lenticular crystals. It is believed to have been deposited during an episode of high regional watertable, causing active groundwater seepage and more frequent surface brine in the playa. A later fall in watertable, probably resulting from climatic change

Sedimentary architecture and optical dating of Middle and Late Pleistocene Rhine-Meuse deposits - Fluvial response to climate change, sea-level fluctuation and glaciation

NARCIS (Netherlands)

Busschers, F.S.; Weerts, H.J.T.; Wallinga, J.; Cleveringa, P.; Kasse, C.; Wolf, H.de; Cohen, K.M.

2005-01-01

Eight continuous corings in the west-central Netherlands show a 15 to 25 m thick stacked sequence of sandy to gravelly channel-belt deposits of the Rhine-Meuse system. This succession of fluvial sediments was deposited under net subsiding conditions in the southern part of the North Sea Basin and

Sedimentary architecture and optical dating of Middle and Late Pleistocene Rhine-Meuse deposits fluvial response to climate change, sea-level fluctuation and glaciation

NARCIS (Netherlands)

Busschers, F.S.; Weerts, H.J.T.; Wallinga, J.; Kasse, C.; Cleveringa, P.; de Wolf, H.; Cohen, K.M.

2005-01-01

Eight continuous corings in the west-central Netherlands show a 15 to 25 m thick stacked sequence of sandy to gravelly channel-belt deposits of the Rhine-Meuse system. This succession of fluvial sediments was deposited under net subsiding conditions in the southern part of the North Sea Basin and

Preliminary report on the geology of uranium deposits in the Browns Park Formation in Moffat County, Colorado, and Carbon County, Wyoming

International Nuclear Information System (INIS)

Ormond, A.

1957-06-01

Uranium was first discovered in the Browns Park Formation in 1951 in the Miller Hill area of south-central Wyoming. Since that time economically important deposits in this formation have been discovered and developed in the Poison Basin of south-central Wyoming and in the Maybell area of northwest Colorado. The Browns Park is the youngest formation (Miocene) in the region and overlies older rocks with angular unconformity. The formation consists of a basal conglomerate, fluviatile, lacustrine, and eolian sandstones, and locally a few thin beds of clay, tuff, and algal limestone. The sandstones are predominantly fine- to medium-grained and consist of quartz grains, scattered black chert grains, and interstitial clay. The uranium deposits are of the sandstone-impregnation type and are not confined to specific stratigraphic horizons. The important ore minerals are autunite and uranophane in oxidized sandstones, and uraninite and coffinite in unoxidized sandstones. Uranium is often associated with limonite and calcium carbonate in concretionary forms. Woody material, thought to play an important part in the deposition of uranium in many sandstone-type deposits, is not present in the deposits of the Browns Park Formation. However, organic carbon in the form of petroleum and petroleum residues has been observed in association with uranium in both the Poison Basin and the Maybell areas

Central Bank Financial Strength and the Cost of Sterilization in China

DEFF Research Database (Denmark)

Ljungwall, Christer; Xiong, Yi; Yutong, Zou

2013-01-01

Using a unique monthly data set over the period 2000:1-2008:12, this paper presents empirical findings on China's central bank, the People's Bank of China, from the viewpoint of its financial strength and the cost of monetary policy instruments. The results show that PBoC is constrained...... by the costs of its monetary policy instruments. PBoC tend to use less costly but market-distorting instruments such as the deposit interest rate cap and reserve-ratio requirements, rather than more market-oriented but more costly instruments such as central bank note issuance. These costs remain under control...

Concentrations, Deposition, and Effects of Nitrogenous Pollutants in Selected California Ecosystems

Directory of Open Access Journals (Sweden)

Andrzej Bytnerowicz

2001-01-01

Full Text Available Atmospheric deposition of nitrogen (N in California ecosystems is ecologically significant and highly variable, ranging from about 1 to 45 kg/ha/year. The lowest ambient concentrations and deposition values are found in the eastern and northern parts of the Sierra Nevada Mountains and the highest in parts of the San Bernardino and San Gabriel Mountains that are most exposed to the Los Angeles air pollution plume. In the Sierra Nevada Mountains, N is deposited mostly in precipitation, although dry deposition may also provide substantial amounts of N. On the western slopes of the Sierra Nevada, the majority of airborne N is in reduced forms as ammonia (NH3 and particulate ammonium (NH4+ from agricultural activities in the California Central Valley. In southern California, most of the N air pollution is in oxidized forms as nitrogen oxides (NOx, nitric acid (HNO3, and particulate nitrate (NO3– resulting from fossil fuel combustion and subsequent complex photochemical reactions. In southern California, dry deposition of gases and particles provides most (up to 95% of the atmospheric N to forests and other ecosystems. In the mixed-conifer forest zone, elevated deposition of N may initially benefit growth of vegetation, but chronic effects may be expressed as deterioration of forest health and sustainability. HNO3 vapor alone has a potential for toxic effects causing damage of foliar surfaces of pines and oaks. In addition, dry deposition of predominantly HNO3 has lead to changes in vegetation composition and contamination of ground- and stream water where terrestrial N loading is high. Long-term, complex interactions between N deposition and other environmental stresses such as elevated ozone (O3, drought, insect infestations, fire suppression, or intensive land management practices may affect water quality and sustainability of California forests and other ecosystems.

Dust Deposition and Migration of the ITCZ through the Last Glacial Cycle in the Central Equatorial Pacific (Line Islands).

Science.gov (United States)

Reimi Sipala, M. A.; Marcantonio, F.

2014-12-01

Atmospheric dust can be used to record climate change in addition to itself playing a role in several key climate processes, such as affecting Earth's albedo, fomenting rain coalescence, encouraging biological productivity, and enhancing carbon export though particle sinks. Using deep sea sediments, it is possible to quantify and locate the sources and sinks of atmospheric dust. A key area of research is the shift in the inter-tropical converge zone (ITCZ), a thermally influenced area that shifts according to the northern and southern hemisphere temperature gradient. This ongoing project focuses on the changes of the ITCZ over the Central Equatorial Pacific (CEP) over the past ~25000 years. The research focuses on two cores taken from the Line Islands Ridge at 0° 29' N (ML1208-18GC), and 4° 41' N (ML1208-31BB). The main aim is to quantify the magnitude and provenance of windblown dust deposited in the CEP, and to address questions regarding the nature of the variations of dust through ice-age climate transitions. Radiogenic isotopes (Sr, Nd, Pb) have been successfully used to distinguish between different potential dust sources in the aluminosilicates fractions of Pacific Sediments. Our preliminary Pb isotope ratios suggest that, for modern deposition, the northern core's (31BB) detrital sediment fraction is likely sourced from Asian Loess (average ratios are 206Pb/204Pb = 18.88, 207Pb/204Pb = 15.69, 208Pb/204Pb = 39.06). The equatorial core's (18GC) detrital fraction has a less radiogenic Pb signature, which is consistent with South American dust sourcing (206Pb/204Pb = 18.62, 207Pb/204Pb = 15.63, 208Pb/204Pb = 38.62). This is indicative of a strong modern ITCZ that acts as an effective barrier for inter-hemispheric dust transport. Prior to Holocene time, the changes in Pb isotope ratios in both cores appear to be in anti-phase; the northern core becomes less radiogenic up to the LGM, while the southern core becomes more radiogenic. This is potentially due to a

Sustained Water Quality Impacts in Marine Environments Due to Mechanical Milling of Volcanic Deposits

Science.gov (United States)

Genareau, K. D.; Cronin, S. J.; Stewart, C.; Back, E.

2015-12-01

Explosive volcanic eruptions are known to be a significant geohazard, but post- or inter-eruptive processes (such as lahars, landslides, and debris avalanches) can be equally damaging to local and regional areas by remobilizing deposits. Numerous studies have found that soluble salts bound to ash grain surfaces may be quickly released into exposed waters, often lowering pH and adding trace metals with both beneficial and deleterious effects on marine flora and fauna (e.g., Fe influx initiating blooms of marine phytoplankton). Most of the cation content of pyroclastic deposits is released slowly into the environment through weathering and alteration processes. However, other pathways exist through the physical comminution of pyroclasts in fluvial and marine settings. In this case, mechanical fracturing of pyroclasts during progressive stages of disaggregation will lead to exposure of reactive particle surfaces. This study evaluates the potential, ongoing effects on water quality by experimental, mechanical milling of pyroclasts and the evaluation of released metals into exposed waters using the pyroclastic density current deposits of both the 2010 eruption of Merapi and the 2014 eruption of Kelud (Java, Indonesia), which have a bulk basaltic andesite/andesite composition (60-65 wt% SiO2). The electrical conductivity (EC) of water samples positively correlates with Ca and Sr concentrations in the case of bulk ash, whole, and crushed lapilli, but correlates with Na for the milled samples. Compared to other stages of pyroclast disaggregation, milled lapilli have the greatest effect on the concentration of alkali elements and produce a significant increase in Ca, Na, K, and Si. Mechanical milling of pyroclasts grinds down minerals and glass, resulting in an increased EC, pH, and Na concentration of exposed waters. Similar experiments are currently being conducted using basalt (50 wt% SiO2) and rhyolite (70 wt% SiO2) deposits, and these results will be presented

Genesis of iron-apatite ores in Posht-e-Badam Block (Central Iran ...

Indian Academy of Sciences (India)

Central Iran; iron-apatite ore; Kiruna-type; Posht-e-Badam Block; REE geochemistry. J. Earth Syst ... ferent ore genesis models have been proposed for ...... volatile-rich magma systems stress the important .... Laco magnetite flow deposits, northern Chile: An up-to- ... economic report on iron ore prevision of the Esfahan steel.

Peat classified as slowly renewable biomass fuel

International Nuclear Information System (INIS)

2001-01-01

thousands of years. The report states also that peat should be classified as biomass fuel instead of biofuels, such as wood, or fossil fuels such as coal. According to the report peat is a renewable biomass fuel like biofuels, but due to slow accumulation it should be considered as slowly renewable fuel. The report estimates that bonding of carbon in both virgin and forest drained peatlands are so high that it can compensate the emissions formed in combustion of energy peat

Use of Calluna vulgaris to detect signals of nitrogen deposition across an urban-rural gradient

Science.gov (United States)

Power, S. A.; Collins, C. M.

2010-05-01

Densely populated cities can experience high concentrations of traffic-derived pollutants, with oxides of nitrogen and ammonia contributing significantly to the overall nitrogen (N) budget of urban ecosystems. This study investigated changes in the biochemistry of in situ Calluna vulgaris plants to detect signals of N deposition across an urban-rural gradient from central London to rural Surrey, UK. Foliar N concentrations and δ 15N signatures were higher, and C/N ratios lower, in urban areas receiving the highest rates of N deposition. Plant phosphorus (P) concentrations were also highest in these areas, suggesting that elevated rates of N deposition are unlikely to result in progressive P-limitation in urban habitats. Free amino acid concentrations were positively related to N deposition for asparagine, glutamine, glycine, phenylalanine, isoleucine, leucine and lysine. Overall, relationships between tissue chemistry and N deposition were similar for oxidised, reduced and total N, although the strength of relationships varied with the different biochemical indicators. The results of this study indicate that current rates of N deposition are having substantial effects on plant biochemistry in urban areas, with likely implications for the biodiversity and functioning of urban ecosystems.

Depositional features and stratigraphic sections in granitic plutons: implications for the emplacement and crystallization of granitic magma

Science.gov (United States)

Wiebe, R. A.; Collins, W. J.

1998-09-01

Many granitic plutons contain sheet-like masses of dioritic to gabbroic rocks or swarms of mafic to intermediate enclaves which represent the input of higher temperature, more mafic magma during crystallization of the granitic plutons. Small-scale structures associated with these bodies (e.g. load-cast and compaction features, silicic pipes extending from granitic layers into adjacent gabbroic sheets) indicate that the sheets and enclave swarms were deposited on a floor of the magma chamber (on granitic crystal mush and beneath crystal-poor magma) while the mafic magma was incompletely crystallized. These structures indicate 'way up', typically toward the interior of the intrusions, and appear to indicate that packages of mafic sheets and enclave concentrations in these plutons are a record of sequential deposition. Hence, these plutons preserve a stratigraphic history of events involved in the construction (filling, replenishment) and crystallization of the magma chamber. The distinctive features of these depositional portions of plutons allow them to be distinguished from sheeted intrusions, which usually preserve mutual intrusive contacts and 'dike-sill' relations of different magma types. The considerable thickness of material that can be interpreted as depositional, and the evidence for replenishment, suggest that magma chamber volumes at any one time were probably much less than the final size of the pluton. Thus, magma chambers may be constructed much more slowly than presently envisaged. The present steep attitudes of these structures in many plutons may have developed gradually as the floor of the chamber (along with the underlying solidified granite and country rock) sank during continuing episodes of magma chamber replenishment. These internal magmatic structures support recent suggestions that the room problem for granites could be largely accommodated by downward movement of country rock beneath the magma chamber.

Primary CNS Nonamyloidogenic Light Chain Deposition Disease: Case Report and Brief Review.

Science.gov (United States)

Mercado, Juan Jose; Markert, James M; Meador, William; Chapman, Philip; Perry, Arie; Hackney, James R

2017-12-01

The true incidence of light chain deposition disease (LCDD) restricted to the central nervous system (CNS) is unknown. To our knowledge only 7 cases of LCDD restricted to the brain have been previously reported. We herein describe an unusual example. A 44-year-old man presented with a history of ischemic retinopathy in 2004 and left lower extremity hypoesthesia in 2007 that progressed gradually to left-sided weakness and numbness in the 2 years prior to his hospitalization in 2015. A stereotactic brain biopsy was performed, displaying nonspecific hyaline deposits of amorphous "amyloid-like" material involving deep brain white matter and vessels. These were Congo red negative and were accompanied by a sparse lymphoplasmacytic infiltrate. Plasma cells demonstrated kappa light chain class restriction by chromogenic in situ hybridization (CISH). There was patchy reactivity with kappa immunohistochemistry in the amorphous deposits. A diagnosis of light chain deposition disease was made. Subsequent systemic myeloma and lymphoma workups were negative. Previously reported cases have included men and women, spanning the ages of 19 and 72 years, often presenting with hemiparesis, hypoesthesia, or seizures. Deposits have been reported in the cerebrum and cerebellum. T2/FLAIR (fluid attenuation inversion recovery) changes are usual, but lesions may or may not produce contrast enhancement. The light chain deposition may be of kappa or lambda class. Most lesions have been accompanied by local lymphoid and/or plasma cell infiltrates exhibiting light chain restriction of the same class as the deposits. In summary, LCDD limited to the CNS is a rare lesion consisting of deposition of amyloid-like, but Congo red-negative monotypic light chain usually produced by local lymphoplasmacytic infiltrates.

The study of mineralization and fluid inclusion in Dehsalm Mahour 2 lead deposit, east of Lut block, Central Iran

Directory of Open Access Journals (Sweden)

Fateme Mohammadpour

2016-09-01

Full Text Available The Mahour 2 lead mineralization area is located, about 145 km west of Nehbandan and 2 km northwest of Mahour polymetal deposit and in the eastern part of Lut Block. The area comprises of volcanic and pyroclastic rocks (Eocene intruded by several intrusive rocks mainly as dioritic dykes and stocks. Mineralization as veins and filling the space, occurred in altered andesitic rocks. Supergene zone is characterized by azurite, malachite, linarite and iron oxides (hematite and limonite whereas, galena, pyrite, chalcopyrite and magnetite are the main minerals of hypogene zone. And, quartz and calcite are main gangue. The area is dominated by four types of alteration including silicic, sericitic, propylitic, and argillic. Fluid inclusions study on quartz mineral sections polished reveals the presence of 1.0 to 5.6 percent salt and homogeneous temperature between 278 to 570 ° C. The high temperature with low salinity zone mineralization in this area is likely related to another generation of mineralization in the area. The results of fluid inclusions show that the mineralization is probably a mixture of magmatic fluid and atmospheric, although there is doubt. Several similar criteria including form of deposit, primary ore deposit, alteration facies, tectonic environment and magmatic series document that there should be a correlation between the origin of the studied mineralization area and that of the Mahour polymetal deposit.

Influence of variable rates of neritic carbonate deposition on atmospheric carbon dioxide and pelagic sediments

Science.gov (United States)

Walker, J. C.; Opdyke, B. C.

1995-01-01

Short-term imbalances in the global cycle of shallow water calcium carbonate deposition and dissolution may be responsible for much of the observed Pleistocene change in atmospheric carbon dioxide content. However, any proposed changes in the alkalinity balance of the ocean must be reconciled with the sedimentary record of deep-sea carbonates. The possible magnitude of the effect of shallow water carbonate deposition on the dissolution of pelagic carbonate can be tested using numerical simulations of the global carbon cycle. Boundary conditions can be defined by using extant shallow water carbonate accumulation data and pelagic carbonate deposition/dissolution data. On timescales of thousands of years carbonate deposition versus dissolution is rarely out of equilibrium by more than 1.5 x 10(13) mole yr-1. Results indicate that the carbonate chemistry of the ocean is rarely at equilibrium on timescales less than 10 ka. This disequilibrium is probably due to sea level-induced changes in shallow water calcium carbonate deposition/dissolution, an interpretation that does not conflict with pelagic sedimentary data from the central Pacific.

THE ACTIVITIES OF THE NATIONAL BANK OF UKRAINE ON THE OPEN MARKET: OPERATION WITH CERTIFICATES OF DEPOSITS

OpenAIRE

Yuliia Harkusha

2016-01-01

In the article investigated the activities of the National Bank of Ukraine on the open market. The analysis of operations of the National Bank of Ukraine banks to raise funds placing deposit certificates. Defined impact operations of the central bank's own debt securities to trading volumes deposit certificates of the National Bank of Ukraine on the stock market and the credit activity of banks. Identified problems interest rate policy and the ways to overcome them. Key words: National Bank o...

Sedimentary architecture and optical dating of Middle and Late Pleistocene Rhine-Meuse deposits – fluvial response to climate change, sea-level fluctuation and glaciation

NARCIS (Netherlands)

Busschers, F.S.; Weerts, H.J.T.; Wallinga, J.; Cleveringa, P.; Kasse, C.; Wolf, H. de; Cohen, K.M.

2005-01-01

Eight continuous corings in the west-central Netherlands show a 15 to 25 m thick stacked sequence of sandy to gravelly channel-belt deposits of the Rhine-Meuse system. This succession of fluvial sediments was deposited under net subsiding conditions in the southern part of the North Sea Basin and

Life cycle assessment of central softening of very hard drinking water

DEFF Research Database (Denmark)

Godskesen, Berit; Hauschild, Michael Zwicky; Rygaard, Martin

2012-01-01

Life Cycle Assessment (LCA) to quantify the environmental impacts of central softening of drinking water considering both the negative effects at the waterworks and the positive effects imposed by the changed water quality in the households. The LCA modeling considered central softening of drinking......Many consumers prefer softened water due to convenience issues such as avoidance of removing limescale deposits from household appliances and surfaces, and to reduce consumption of cleaning agents and laundry detergents leading to lower household expenses. Even though central softening of drinking...... water entailed an increased use of energy, sand and chemicals at the waterworks, the distributed and softened drinking water supported a decrease in consumption of energy and chemical agents in the households along with a prolonged service life of household appliances which heat water. This study used...

Pigmented Creatine Deposits in Amyotrophic Lateral Sclerosis Central Nervous System Tissues Identified by Synchrotron Fourier Transform Infrared Microspectroscopy and X-ray Fluorescence Spectromicroscopy

Energy Technology Data Exchange (ETDEWEB)

Kastyak, M.; Szczerbowska-Boruchowska, M; Adamek, D; Tomik, B; Lankosz, M; Gough, K

2010-01-01

Amyotrophic Lateral Sclerosis (ALS) is an untreatable, neurodegenerative disease of motor neurons characterized by progressive muscle atrophy, limb paralysis, dysarthria, dysphagia, dyspnae and finally death. Large motor neurons in ventral horns of spinal cord and motor nuclei in brainstem, large pyramidal neurons of motor cortex and/or large myelinated axons of corticospinal tracts are affected. In recent synchrotron Fourier Transform Infrared microspectroscopy (sFTIR) studies of ALS CNS autopsy tissue, we discovered a small deposit of crystalline creatine, which has a crucial role in energy metabolism. We have now examined unfixed, snap frozen, post-autopsy tissue sections of motor cortex, brain stem, spinal cord, hippocampus and substantia nigra from six ALS and three non-degenerated cases with FTIR and micro-X-ray fluorescence (XRF). Heterogeneous pigmented deposits were discovered in spinal cord, brain stem and motor neuron cortex of two ALS cases. The FTIR signature of creatine has been identified in these deposits and in numerous large, non-pigmented deposits in four of the ALS cases. Comparable pigmentation and creatine deposits were not found in controls or in ALS hippocampus and substantia nigra. Ca, K, Fe, Cu and Zn, as determined by XRF, were not correlated with the pigmented deposits; however, there was a higher incidence of hot spots (Ca, Zn, Fe and Cu) in the ALS cases. The identity of the pigmented deposits remains unknown, although the absence of Fe argues against both erythrocytes and neuromelanin. We conclude that elevated creatine deposits may be indicators of dysfunctional oxidative processes in some ALS cases.

The Kongsberg silver deposits, Norway: Ag-Hg-Sb mineralization and constraints for the formation of the deposits

Science.gov (United States)

Kotková, Jana; Kullerud, Kåre; Šrein, Vladimír; Drábek, Milan; Škoda, Radek

2018-04-01

The Kongsberg silver district has been investigated by microscopy and electron microprobe analysis, focusing primarily on the Ag-Hg-Sb mineralization within the context of the updated mineral paragenesis. The earliest mineralization stage is represented by sulfides, including acanthite, and sulfosalts. Native silver formed initially through breakdown of early Ag-bearing phases and later through influx of additional Ag-bearing fluids and silver remobilization. The first two generations of native silver were separated in time by the formation of Ni-Co-Fe sulfarsenides and the monoarsenide niccolite along rims of silver crystals. The presence of As-free sulfosalts and the absence of di- and tri-arsenides suggest a lower arsenic/sulfur activity ratio for the Kongsberg deposits compared to other five-element deposits. Native silver shows binary Ag-Hg and Ag-Sb solid solutions, in contrast to the ternary Ag-Hg-Sb compositions typical for other deposits of similar type. Antimonial silver together with allargentum, dyscrasite, and pyrargyrite was documented exclusively from the northern area of the district. Elsewhere, the only Sb-bearing minerals are polybasite and tetrahedrite/freibergite. Hg-rich silver (up to 21 wt% Hg) has been documented only in the central-western area. Myrmekite of freibergite and chalcopyrite reflects exsolution from an original Ag-poor tetrahedrite upon cooling, while myrmekite of pyrite and silver, forming through breakdown of low-temperature phases (argentopyrite or lenaite) upon heating, characterizes the Kongsberg silver district. Based on the stabilities of minerals and mineral assemblages, the formation of the silver mineralization can be constrained to temperatures between 180 and 250 °C.

Lichens as biomonitors of atmospheric ammonium/ammonia deposition in Portugal

International Nuclear Information System (INIS)

Capelao, A.L.; Maguas, C.; Branquinho, C.; Cruz, C.; Martins-Loucao, M.A.

2000-01-01

The aim of the present work was to evaluate the potentiality of lichens as biomonitors of NH 4 + /NH 3 (ammonium/ammonia) and NO 3 - (nitrate) atmospheric deposition. For that, we used as a field station a rice plantation which is submitted, once a year, to air spraying fertilization with a mixture of nitrogen sources. Samples of an epiphytic lichen, Ramalina fastigiata, were collected from an ash-tree bordering the rice-plantation by the Sorraia River Valley (Central Portugal). The study started one month before fertilization and sampling was carried out for five months. The concentration of ammonium in the lichen was highly and significantly correlated with the number of days without precipitation before sampling, and had an inverse correlation with fluorescence values. Under these conditions, the amount of NH 4 + found in the lichen appears to reflect ammonium/ammonia dry deposition. (author)

Intermontane eolian sand sheet development, Upper Tulum Valley, central-western Argentina

Directory of Open Access Journals (Sweden)

Patrick Francisco Fuhr Dal' Bó

Full Text Available ABSTRACTThe intermontane Upper Tulum eolian sand sheet covers an area of ca. 125 km² at north of the San Juan Province, central-western Argentina. The sand sheet is currently an aggrading system where vegetation cover, surface cementation and periodic flooding withhold the development of dunes with slipfaces. The sand sheet surface is divided into three parts according to the distribution of sedimentary features, which reflects the variation in sediment budget, water table level and periodic flooding. The central sand sheet part is the main area of eolian deposition and is largely stabilized by vegetation. The sedimentary succession is 4 m thick and records the vertical interbedding of eolian and subaqueous deposits, which have been deposited for at least 3.6 ky with sedimentation rates of 86.1 cm/ky. The construction of the sand sheet is associated with deflation of the sand-graded debris sourced by San Juan alluvial fan, which is available mainly in drier fall-winter months where water table is lower and wind speeds are periodically above the threshold velocity for sand transport. The accumulation of sedimentary bodies occurs in a stabilized eolian system where vegetation cover, thin mud veneers and surface cementation are the main agents in promoting accumulation. The preservation of the sand sheet accumulations is enabled by the progressive creation of the accommodation space in a tectonically active basin and the continuous burial of geological bodies favored by high rates of sedimentation.

The Central Institute for Brain Research in Amsterdam and its directors.

Science.gov (United States)

Eling, Paul; Hofman, Michel A

2014-01-01

The Central Institute for Brain Research was founded in Amsterdam in 1908 as part of an international effort to study the nervous system with multiple institutions and various disciplines. The development of research in the past hundred years at the Brain Institute has hardly been documented. We analyze the history of this institute by means of brief portraits of its directors and their main research topics. It appears that each director introduced his own branch of neuroscience into the institute. Initially, mainly comparative neuroanatomical data were collected. Following the Second World War, the multidisciplinary approach slowly developed with research programs on systems neuroscience, neuroendocrinology, and brain disorders. Every new director introduced new approaches to the study of the brain and thus played an important role in keeping brain research in the Netherlands at the international forefront where it has been ever since its foundation in 1908.

Calibrating water depths of Ordovician communities: lithological and ecological controls on depositional gradients in Upper Ordovician strata of southern Ohio and north-central Kentucky, USA

Directory of Open Access Journals (Sweden)

Carlton E. Brett

2015-02-01

Full Text Available Limestone and shale facies of the Upper Ordovician Grant Lake Formation (Katian: Cincinnatian, Maysvillian are well exposed in the Cincinnati Arch region of southern Ohio and north-central Kentucky, USA. These rocks record a gradual change in lithofacies and biofacies along a gently northward-sloping ramp. This gradient spans very shallow, olive-gray, platy, laminated dolostones with sparse ostracodes in the south to offshore, nodular, phosphatic, brachiopod-rich limestones and marls in the north. This study uses facies analysis in outcrop to determine paleoenvironmental parameters, particularly those related to water depth (e.g., position of the photic zone and shoreline, relative degree of environmental energy. Within a tightly correlated stratigraphic interval (the Mount Auburn and Straight Creek members of the Grant Lake Formation and the Terrill Member of the Ashlock Formation, we document the occurrence of paleoenvironmental indicators, including desiccation cracks and light-depth indicators, such as red and green algal fossils and oncolites. This permitted recognition of a ramp with an average gradient of 10–20 cm water depth per horizontal kilometer. Thus, shallow subtidal (“lagoonal” deposits in the upramp portion fall within the 1.5–6 m depth range, cross-bedded grainstones representing shoal-type environments fall within the 6–18 m depth range and subtidal, shell-rich deposits in the downramp portion fall within the 20–30 m depth range. These estimates match interpretations of depth independently derived from faunal and sedimentologic evidence that previously suggested a gentle ramp gradient and contribute to ongoing and future high-resolution paleontologic and stratigraphic studies of the Cincinnati Arch region.

Risk assessment of metals in road-deposited sediment along an urban–rural gradient

International Nuclear Information System (INIS)

Zhao, Hongtao; Li, Xuyong

2013-01-01

We applied the traditional risk assessment methods originally designed for soils and river sediments to evaluation of risk associated with metals in road-deposited sediment (RDS) along an urban–rural gradient that included central urban (UCA), urban village (UVA), central suburban county (CSA), rural town (RTA), and rural village (RVA) areas in the Beijing metropolitan region. A new indicator RI RDS was developed which integrated the RDS characteristics of mobility, grain size and amount with the potential ecological risk index. The risk associated with metals in RDS in urban areas was generally higher than that in rural areas based on the assessment using traditional methods, but the risk was higher in urban and rural village areas than the areas with higher administration units based on the indicator RI RDS . These findings implied that RDS characteristics variation with the urban–rural gradient must be considered in metal risk assessment and RDS washoff pollution control. Highlights: ► Spatial pattern of metal risk level associated with road-deposited sediment (RDS) along urban–rural gradients varied. ► Risk level of metals changed significantly when grain size was considered. ► A new index integrating RDS characteristics and potential ecological risk was developed. ► Results from the new index were improved relative to those of traditional assessment methods. -- A new index integrating road-deposited sediment characteristics and potential ecological risk was developed to assess metal risk along the urban–rural gradient

Source sector and region contributions to BC and PM2.5 in Central Asia

NARCIS (Netherlands)

Kulkarni, S.; Sobhani, N.; Miller-Schulze, J.P.; Shafer, M.M.; Schauer, J.J.; Solomon, P.A.; Saide, P.E.; Spak, S.N.; Cheng, Y.F.; Denier Van Der Gon, H.A.C.; Lu, Z.; Streets, D.G.; Janssens-Maenhout, G.; Wiedinmyer, C.; Lantz, J.; Artamonova, M.; Chen, B.; Imashev, S.; Sverdlik, L.; Deminter, J.T.; Adhikary, B.; D'Allura, A.; Wei, C.; Carmichael, G.R.

2015-01-01

Particulate matter (PM) mass concentrations, seasonal cycles, source sector, and source region contributions in Central Asia (CA) are analyzed for the period April 2008-July 2009 using the Sulfur Transport and dEposition Model (STEM) chemical transport model and modeled meteorology from the Weather

Ground-water availability in the central part of Lake Ontario basin, New York

Science.gov (United States)

Miller, Todd S.; Krebs, Martha M.

1988-01-01

A set of three maps showing surficial geology, distribution of glacial aquifers, and potential well yield in the 708 sq mi central part of the Lake Ontario basin are presented at a scale of 1:125,000. The basin is parallel to Lake Ontario and extends from Rochester in the west to Oswego in the east. Aquifers consisting primarily of sand and gravel formed where meltwaters from glaciers deposited kame and outwash sand and gravel and where wave action along shores of glacial lakes eroded, reworked , and deposited beaches. Thick deposits of well-sorted sand and gravel yield relatively large quantities of water - typically more than 100 gal/min. Aquifers consisting of thin beds of sand and (or) gravel or thick gravel that contain a large proportion of silt and fine sand yield moderate amounts of water, 10 to 100 gal/min. Dug and driven wells that tap fine to medium sand deposits typically yield 1 to 10 gal/min. (USGS)

Thorium prospect of placer deposits in Koba area and its surroundings

International Nuclear Information System (INIS)

Ngadenin; Fd Dian Indrastomo; Widodo

2012-01-01

The objective of the present study of the thorium in placer of Koba, Central Bangka District. Bangka Belitung Province and its surrounding is to find out thorium prospect in alluvial deposits. The study method are geological and radiometrical mapping, grain counting and thorium grade analysis of pan concentrated. Result of the research reveals that lithology of the investigation area compose of meta sandstone unit with radiometric value of 35 c/s - 200 c/s, granite intrusion with radiometric value of 140-550 c/s and alluvial with radiometric value of 40-300 c/s SPP2NF. Content of monazite in the pan concentrated is approximately 7.54 %, content of thorium in pan concentrated of 1410 ppm, covered alluvial deposits of about 400 kilometers square with average thickness 3.77 meters. According to the study thorium prospect in Koba area is feasible to be Based on the type of deposit (placer) which are relatively easy to be mined at low cost, high content of monazite and thorium so that the prospect thorium Koba feasible to develop. (author)

Mud Lake, a modern analog of oil shale deposition in Florida

Energy Technology Data Exchange (ETDEWEB)

Burgess, J.D.

1987-01-01

Mud Lake in north-central Florida was identified by Bradley as an analog of oil shale-type kerogen deposition. This lake supports an abundant diatom and algal flora which is unique in that the accumulating algal ooze does not decay as long as it stays oxygenated. This same material does not nutritionally support many invertebrates, owing to its flocculent consistency and apparent indigestibility, although fish are abundant and an occasional crocodile is found in the lake. Accumulation of the algal ooze is very slow at roughly 1 foot per 52,000 years based on radiocarbon dates. An understanding of oil shale depositional conditions could be translated into a predictive model for location and recognition of hydrocarbon generating source rocks. When oil shales are mentioned the first association is likely to be that with the Eocene Green River Formation of the Western US. Conditions leading to deposition and preservation of this massive quantity of organic debris is difficult to comprehend, but recognition of modern analogs provide an available area for study and comparison.

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

Mineralization, geochemistry, fluid inclusion and sulfur stable isotope studies in the carbonate hosted Baqoroq Cu-Zn-As deposit (NE Anarak)

OpenAIRE

Mohammad Ali Jazi; Mohammad Hassan Karimpour; Azadeh Malekzadeh Shafaroudi

2015-01-01

Introduction The Baqoroq Cu-Zn-As deposit is located northeast of the town ofAnarak in Isfahan province, in theeast central areaof Iran. Copper mineralization occursin upper cretaceous carbonate rocks.Studyof thegeologyof the Nakhlak area, the location ofa carbonate-hosted base metaldeposit, indicatesthe importance of stratigraphic, lithological and structural controls in the placement of this ore deposit. (Jazi et al., 2015).Some of the most world’s most important epigenetic, stratabo...

Measurements of ammonia concentrations, fluxes and dry deposition velocities to a spruce forest 1991-1995

DEFF Research Database (Denmark)

Andersen, H.V.; Hovmand, M.F.; Hummelshøj, P.

1999-01-01

The dry deposition velocities and fluxes of ammonia have been estimated from measurements of the vertical gradient of ammonia and micrometeorology above a spruce forest in western Jutland, Denmark. Measurements have been made in seven periods, each lasting about one week and covering all seasons...... measuring period characterized by easterly winds with dry conditions and high ammonia concentrations, and the emissions might relate to evaporation from ammonia saturated surfaces or emission from mineralization in the forest soil. In general, relatively high net deposition velocities were observed during...... at conditions with easterly winds, the air have passed central Jutland with large emission areas. Some of the relatively low deposition velocities or emissions were observed during conditions with low ammonia concentration and westerly winds. These observations might relate to a compensation point of the forest...

Effects of Preprocessing on Multi-Direction Properties of Aluminum Alloy Cold-Spray Deposits

Science.gov (United States)

Rokni, M. R.; Nardi, A. T.; Champagne, V. K.; Nutt, S. R.

2018-05-01

The effects of powder preprocessing (degassing at 400 °C for 6 h) on microstructure and mechanical properties of 5056 aluminum deposits produced by high-pressure cold spray were investigated. To investigate directionality of the mechanical properties, microtensile coupons were excised from different directions of the deposit, i.e., longitudinal, short transverse, long transverse, and diagonal and then tested. The results were compared to properties of wrought 5056 and the coating deposited with as-received 5056 Al powder and correlated with the observed microstructures. Preprocessing softened the particles and eliminated the pores within them, resulting in more extensive and uniform deformation upon impact with the substrate and with underlying deposited material. Microstructural characterization and finite element simulation indicated that upon particle impact, the peripheral regions experienced more extensive deformation and higher temperatures than the central contact zone. This led to more recrystallization and stronger bonding at peripheral regions relative to the contact zone area and yielded superior properties in the longitudinal direction compared with the short transverse direction. Fractography revealed that crack propagation takes place along the particle-particle interfaces in the transverse directions (caused by insufficient bonding and recrystallization), whereas through the deposited particles, fracture is dominant in the longitudinal direction.

Financial development and energy consumption in Central and Eastern European frontier economies

International Nuclear Information System (INIS)

Sadorsky, Perry

2011-01-01

This study examines the impact of financial development on energy consumption in a sample of 9 Central and Eastern European frontier economies. Several different measures of financial development are examined including bank related variables and stock market variables. The empirical results, obtained from dynamic panel demand models, show a positive and statistically significant relationship between financial development and energy consumption when financial development is measured using banking variables like deposit money bank assets to GDP, financial system deposits to GDP, or liquid liabilities to GDP. Of the three stock market variables investigated, only one, stock market turnover, has a positive and statistically significant impact on energy consumption. Both short-run and long-run elasticities are presented. The implications of these results for energy policy are discussed. - Research Highlights: → Financial development affects energy consumption in 9 Central and Eastern European frontier economies. → Bank variables have a larger impact on energy consumption than do stock market variables. → Long run bank elasticities range from 0.117 to 0.276. → These results have implications for energy demand forecasts and greenhouse gas emissions.

Oxygen, hydrogen, sulfur, and carbon isotopes in the Pea Ridge magnetite-apatite deposit, southeast Missouri, and sulfur isotope comparisons to other iron deposits in the region

Science.gov (United States)

Johnson, Craig A.; Day, Warren C.; Rye, Robert O.

2016-01-01

Oxygen, hydrogen, sulfur, and carbon isotopes have been analyzed in the Pea Ridge magnetite-apatite deposit, the largest historic producer among the known iron deposits in the southeast Missouri portion of the 1.5 to 1.3 Ga eastern granite-rhyolite province. The data were collected to investigate the sources of ore fluids, conditions of ore formation, and provenance of sulfur, and to improve the general understanding of the copper, gold, and rare earth element potential of iron deposits regionally. The δ18O values of Pea Ridge magnetite are 1.9 to 4.0‰, consistent with a model in which some magnetite crystallized from a melt and other magnetite—perhaps the majority—precipitated from an aqueous fluid of magmatic origin. The δ18O values of quartz, apatite, actinolite, K-feldspar, sulfates, and calcite are significantly higher, enough so as to indicate growth or equilibration under cooler conditions than magnetite and/or in the presence of a fluid that was not entirely magmatic. A variety of observations, including stable isotope observations, implicate a second fluid that may ultimately have been meteoric in origin and may have been modified by isotopic exchange with rocks or by evaporation during storage in lakes.Sulfur isotope analyses of sulfides from Pea Ridge and seven other mineral deposits in the region reveal two distinct populations that average 3 and 13‰. Two sulfur sources are implied. One was probably igneous melts or rocks belonging to the mafic- to intermediate-composition volcanic suite that is present at or near most of the iron deposits; the other was either melts or volcanic rocks that had degassed very extensively, or else volcanic lakes that had trapped rising magmatic gases. The higher δ34S values correspond to deposits or prospects where copper is noteworthy—the Central Dome portion of the Boss deposit, the Bourbon deposit, and the Vilander prospective area. The correspondence suggests that (1) sulfur either limited the deposition

Pb-Zn mineralization of the Ali ou Daoud area (Central High Atlas, Morocco): characterisation of the deposit and relationships with the clay assemblages; Mineralisation Pb-Zn du type MVT de la region d'Ali ou Daoud (Haut Atlas Central, Maroc): caracterisations du gite et relations avec les corteges de mineraux argileux

Energy Technology Data Exchange (ETDEWEB)

Mouguina, E. M.; Daoudi, L.

2008-07-01

Zn-Pb-Fe ores in the Ali ou Daoud deposit (Central High Atlas) are found as stratiform levels and as karst fillings in carbonate platforms facies of Bajocian age. Tectonic structures (e.g., syn sedimentary faults) played a relevant role in the ore emplacement. The dolomitic ore-related host-rock levels are characterized by the presence of kaolinite enrichment in clay levels in amounts directly related to the proportion of the clay minerals. The latter is evidenced by correlation between kaolinite and sulphide contents, suggesting that the installation of kaolinite and mineralizations would result from the same hydrothermal fluid. (Author) 55 refs.

Nitrogen deposition alters nitrogen cycling and reduces soil carbon content in low-productivity semiarid Mediterranean ecosystems

International Nuclear Information System (INIS)

Ochoa-Hueso, Raúl; Maestre, Fernando T.; Ríos, Asunción de los; Valea, Sergio; Theobald, Mark R.; Vivanco, Marta G.; Manrique, Esteban; Bowker, Mathew A.

2013-01-01

Anthropogenic N deposition poses a threat to European Mediterranean ecosystems. We combined data from an extant N deposition gradient (4.3–7.3 kg N ha −1 yr −1 ) from semiarid areas of Spain and a field experiment in central Spain to evaluate N deposition effects on soil fertility, function and cyanobacteria community. Soil organic N did not increase along the extant gradient. Nitrogen fixation decreased along existing and experimental N deposition gradients, a result possibly related to compositional shifts in soil cyanobacteria community. Net ammonification and nitrification (which dominated N-mineralization) were reduced and increased, respectively, by N fertilization, suggesting alterations in the N cycle. Soil organic C content, C:N ratios and the activity of β-glucosidase decreased along the extant gradient in most locations. Our results suggest that semiarid soils in low-productivity sites are unable to store additional N inputs, and that are also unable to mitigate increasing C emissions when experiencing increased N deposition. -- Highlights: •Soil organic N does not increase along the extant N deposition gradient. •Reduced N fixation is related to compositional shifts in soil cyanobacteria community. •Nitrogen cycling is altered by simulated N deposition. •Soil organic C content decrease along the extant N deposition gradient. •Semiarid soils are unable to mitigate CO 2 emissions after increased N deposition. -- N deposition alters N cycling and reduces soil C content in semiarid Mediterranean ecosystems

Development of countermeasure against scale deposition at steam generators of PWRs

International Nuclear Information System (INIS)

Domae, M.; Miyajima, K.; Hirano, H.; Kushida, H.

2002-01-01

Scale deposition has occurred at steam generators of several PWRs. The scale deposition may lead to reduction of flow rate of coolant, deterioration of heat exchanging efficiency and so on. These phenomena affect plant operation performance. Thus, elucidation of the mechanism of the scale deposition and some effective countermeasure are required. In CRIEPI (Central Research Institute of Electric Power Industry), the scale deposition is studied from two aspects: fluid dynamics and water chemistry. Concerning the water chemistry, we think that electro-kinetic behavior of scale, that is, metal oxides is of great importance. The final goal of the water chemical approach is to evaluate electro-kinetic potential (zeta potential) of metal oxides such as magnetite (Fe 3 O 4 ) and hematite (Fe 2 O 3 ), and to develop some countermeasure of the scale deposition based on the electro-kinetic data. As a first step, the zeta potential of 25 μm Fe 3 O 4 particles was measured by the streaming potential method at room temperature, and effect of dispersant addition was studied. The dispersants examined were poly-acrylic acid (PAA, M w ∝ 25,000) and polyvinylpyrrolidone (PVP, M w ∝ 40,000). It has been found that the addition of PAA of more than 10 ppm lowers the zeta potentials by 5 - 15 mV in whole pH range, and that the addition of PVP of more than 10 ppm reduces absolute value of the zeta potentials. (authors)

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,

Sediment-Hosted Zinc-Lead Deposits of the World - Database and Grade and Tonnage Models

Science.gov (United States)

Singer, Donald A.; Berger, Vladimir I.; Moring, Barry C.

2009-01-01

This report provides information on sediment-hosted zinc-lead mineral deposits based on the geologic settings that are observed on regional geologic maps. The foundation of mineral-deposit models is information about known deposits. The purpose of this publication is to make this kind of information available in digital form for sediment-hosted zinc-lead deposits. Mineral-deposit models are important in exploration planning and quantitative resource assessments: Grades and tonnages among deposit types are significantly different, and many types occur in different geologic settings that can be identified from geologic maps. Mineral-deposit models are the keystone in combining the diverse geoscience information on geology, mineral occurrences, geophysics, and geochemistry used in resource assessments and mineral exploration. Too few thoroughly explored mineral deposits are available in most local areas for reliable identification of the important geoscience variables, or for robust estimation of undiscovered deposits - thus, we need mineral-deposit models. Globally based deposit models allow recognition of important features because the global models demonstrate how common different features are. Well-designed and -constructed deposit models allow geologists to know from observed geologic environments the possible mineral-deposit types that might exist, and allow economists to determine the possible economic viability of these resources in the region. Thus, mineral-deposit models play the central role in transforming geoscience information to a form useful to policy makers. This publication contains a computer file of information on sediment-hosted zinc-lead deposits from around the world. It also presents new grade and tonnage models for nine types of these deposits and a file allowing locations of all deposits to be plotted in Google Earth. The data are presented in FileMaker Pro, Excel and text files to make the information available to as many as possible. The

Ore horizons, ore facies, mineralogy and geochemistry of volconogenic massive sulfide (VMS deposits of the Varandan Ba-Pb-Cu deposit, southwest of Qamsar - Iran

Directory of Open Access Journals (Sweden)

Fayeq Hashemi

2017-11-01

Full Text Available Introduction The Varandan Ba-Pb-Cu deposits are located15 km southwest of the town of Qamsar and approximately 7 km south west of the Qazaan village, in the Urumieh- Dokhtar magmatic arc. The Kashan region that is situated in west-central Iran hosts several barite-base metal deposits and occurrences, the biggest ones are the Varandan Ba-Pb-Cu (case considered in this study and the Tapeh-Sorkh (Khalajmaasomi et al., 2010 and Dorreh Ba (Nazari, 1994 deposits. Previous researchers (Izadi, 1996; Farokhpey et al., 2010 have proposed an epithermal model for formation of the Varandan deposit. However, based on some feature of the deposit, it seems that this genetic model may not be correct. Therefore, it is necessary to do more precise research studies on the deposit. The main purpose of this paper is to discuss the genesis of the Varandan deposit based on geological, ore facies, mineralogy, wall rock alterations, and geochemical studies. Materials and methods A field study and sampling was performed during the summer of 2013. To assess the geochemical characteristics of the deposit, about 17 systematic samples from different ore facies of the first, second and third sub-horizon were collected for petrography and mineralogy, and for inductively coupled plasma-atomic emission spectroscopy(ICP-AES, X-ray diffraction (XRD and X-ray fluorescence (XRF geochemical analysis methods. The microscopic studies were done in the optics laboratory of the Shahrood University, and the geochemical analyzes were conducted in laboratories of the Center of Research and Mineral Processing Ore Minerals of Iran, Karaj, Iran. Results The host sequence in the Varandan deposit involves three units, from bottom to top: Unit1: grey, green siliceous tuff, brecciated tuff, crystal tuff and andesite; Unit2: white grey nummulitic limestone, limy tuff and marl: and Unit3: tuff breccia and crystal lithic tuff. Mineralization in the Varandan deposit has occurred as four ore sub

Biostratigraphical correlation of a new interglacial lacustrine deposit from Lind, western Jutland, Denmark

DEFF Research Database (Denmark)

Odgaard, Bent Vad; Krohn, Charlotte Fog; Kronborg, Christian

2008-01-01

and animal macrofossils and two cores were secured from the central part of the basin where the lacustrine deposits have a thickness of about 15 m. The stratigraphy of the deposit can be subdivided into unit A: a lake marl (4 m) superimposed by 3 metres of diatomite and sealed by a thin diamicton. On top...... of unit A follows unit B: 4 metres of gyttja, calcareous at the basal part and sealed by 40 cm of clay. Finally unit C on top of unit B is represented by 1.5 metres of gyttja. The pollen record of unit A can be correlated to the classical Danish record from the nearby Harreskov site (Andersen 1965...

Reduced Incidence of Slowly Progressive Heymann Nephritis in Rats Immunized With a Modified Vaccination Technique

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Arpad Z. Barabas

2006-01-01

Full Text Available A slowly progressive Heymann nephritis (SPHN was induced in three groups of rats by weekly injections of a chemically modified renal tubular antigen in an aqueous medium. A control group of rats received the chemically unmodified version of the antigen in an aqueous solution. One group of SPHN rats were pre- and post-treated with weekly injections of IC made up of rKF3 and rarKF3 IgM antibody at antigen excess (MIC (immune complexes [ICs] containing sonicated ultracentrifuged [u/c] rat kidney fraction 3 [rKF3] antigen and IgM antibodies specific against the antigen, at slight antigen excess. One group of SPHN rats were post-treated with MIC 3 weeks after the induction of the disease and one group of SPHN animals received no treatment. The control group of rats received pre- and post-treatment with sonicated u/c rKF3.

Genesis of iron-apatite ores in Posht-e-Badam Block (Central Iran) using REE geochemistry

Science.gov (United States)

Mokhtari, Mir Ali Asghar; Zadeh, Ghader Hossein; Emami, Mohamad Hashem

2013-06-01

Rare earth elements in apatites of different ore types show characteristic patterns which are related to different modes of formation of the ores. Most of the apatite-bearing iron ores are associated with alkaline magmas with LREE/HREE fractionation varying from moderate to steep. Iron-apatite deposits in Posht-e-Badam Block (Central Iran) have a high concentration of REE (more than 1000 ppm up to 2.5%), and show a strong LREE/HREE ratio with a pronounced negative Eu anomaly. This REE pattern is typical of magmatic apatite and quiet distinct from sedimentary apatites (phosphorites) which have a low REE contents and Ce negative anomalies. On the other hand, they are comparable to the REE patterns of apatites in Kiruna-type iron ores in different parts of the world. The REE patterns of apatites, iron-apatite ores and iron ores are similar and only have different REE contents. This similarity indicates a genetic relation for these rocks. Most of the iron-apatite deposits in Central Iran have similar REE patterns too, which in turn show a genetic relation for all of these deposits. This similarity indicates a similar origin and processes in their genesis. There are some small intrusions around some of the iron-apatite deposits that are petrographically identified as syenite and gabbro. These intrusions also have REE patterns similar to that of iron-apatite ores. This demonstrates a genetic relation between these intrusions and iron-apatite ores. The REE patterns of apatites in different deposits of Posht-e-Badam Block iron-apatite ores show an affinity to alkaline to sub-alkaline magmas and rifting environment. The alkaline host rocks of Central Iran iron-apatite ores are clearly related to an extensional setting where rifting was important (SSE-NNW fault lines). A probable source for this large scale ore forming processes is relatively low partial melting of mantle rocks. The ores have originated by magmatic differentiation as a late phase in the volcanic cycle

Trends of deposition fluxes and loadings of sulfur dioxide and nitrogen oxides in the artificial Three Northern Regions Shelter Forest across northern China

International Nuclear Information System (INIS)

Zhang, Xiaodong; Huang, Tao; Zhang, Leiming; Gao, Hong; Shen, Yanjie; Ma, Jianmin

2015-01-01

This study provides the first estimate of dry deposition fluxes of criteria air pollutants (SO_2 and NO_x) across the Three Northern Regions Shelter Forest (TNRSF) region in Northern China and their long-term trends from 1982 to 2010 using the inferential method. Dry deposition velocities of SO_2 and NO_x increased in many places of the TNRSF up to 118.2% for SO_2 and 112.1% for NO_x over the last three decades due to the increased vegetation coverage over the TNRSF. The highest atmospheric deposition fluxes of SO_2 and NO_x were found in the Central-North China region, followed by the Northeast and the Northwest China regions of the TNRSF. A total of 820,000 t SO_2 and 218,000 t NO_x was estimated to be removed from the atmosphere through dry deposition process over the TNRSF from 1982 to 2010. About 50% of the total removal occurred in the Central-North China region. The estimated total SO_2 and NO_x dry deposition fluxes from 1982 to 2010 between a TNRSF site in this region and an adjacent farmland outside the TNRSF showed that the fluxes of these two chemicals at the TNRSF site were the factors of 2–3 greater than their fluxes in the farmland. - Highlights: • We investigate removal of air pollutants by the Three-North Shelter Forest (Green Great Wall) in China. • The trend of SO_2 and NO_x dry deposition velocity and flux over the TNRSF increase over the last three decades. • Increasing trends of deposition fluxes of SO_2 and NO_x are more evident in Central-North and Northeast China. • We show higher deposition fluxes of SO_2 and NO_x within the TNSF than outside TNRSF. • Stronger removal of air pollutants by the TNRSF is expected when other criteria air pollutants are taken into account. - The TNRSF is demonstrated to be an effective sink for SO_2 and NO_x and has increased the removal of air pollutants from Northern China.

Eruption and Degassing Processes in a Supervolcanic System: The Volatile Record Preserved in Melt Inclusions from the 3.49Ma Tara Ignimbrite in the Central Andes

Science.gov (United States)

Grocke, S.; de Silva, S. L.; Schmitt, A. K.; Wallace, P. J.

2010-12-01

Analysis of H2O and CO2 in quartz and sanidine-hosted melt inclusions from one of the youngest supervolcanic eruptions in the Altiplano Puna Volcanic Complex (APVC) in the Central Andes provides information on crystallization depths and eruption and degassing processes. At least 740 km3 of high-K, metaluminous, rhyodacite to rhyolite magma erupted from the Guacha Caldera in southwest Bolivia, producing three phases of the 3.49 Ma Tara Ignimbrite: a Plinian fall-deposit, an extensive ignimbrite, and several post-caldera domes. Infrared spectroscopic analyses of quartz-hosted melt inclusions from Tara Plinian pumice have H2O contents of ~4.5 wt % and variable CO2 contents (110-300 ppm), corresponding to vapor saturation pressures up to 180 MPa. In contrast, sanidine-hosted melt inclusions from the Plinian-fall deposit contain bubbles, lower water contents (1.4-2.2 wt %) and lower CO2 (87-143 ppm). These vesiculated melt inclusions and low volatile contents suggest that the sanidine crystals leaked on their ascent to the surface and therefore do not record accurate pre-eruptive melt volatile contents. In contrast, quartz-hosted melt inclusions from post-caldera dome samples contain lower H2O contents of 2.5-3.5 wt % (average 2.9 wt %) and no detectable CO2, corresponding to vapor saturation pressures of 50-90 MPa. These data indicate that the preeruptive plinian stage Tara magma was vapor saturated at the time of melt inclusion entrapment and stored between 5-6 km, while those from the post-caldera domes were trapped at 2-3 km. Differences in CO2 between Plinian and dome melt inclusions require that the post-caldera dome quartzes represent a different generation of crystals that grew as the magma slowly rose and progressively degassed at 2-3 km. During this shallow crystallization, the magma evolved further and eventually fed the post-caldera domes, one of which is a high-Si rhyolite. Consistent with this interpretation, melt inclusions from post-caldera dome samples

Mineralogy of the Tertiary Clay Deposits in Makkah and Rabigh Quadrangles, West Central Arabian Shield, Saudi Arabia

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M.H. Basyoni

2002-06-01

Full Text Available The mineralogy of the Tertiary clay deposits in Makkah and Rabigh quadrangles was thoroughly investigated by X-ray diffraction and differential thermal and thermogravimetric analyses in addition to other techniques. Results show that the investigated samples are predominantly composed of montmorillonite (Ca++ and/or Mg++ rich variety and kaolinite, associated with subordinate illite and minor chlorite. Mixed layer montmorillonite-illite is recorded only in two samples. The relative abundance of these minerals by X-ray diffraction analysis showed that the studied clay deposits are of three types. The first, which is the most common, is highly montmorillonitic, the second is made up of a mixture of montmorillonite followed by kaolinite and illite and the third is highly kaolinitic with some montmorillonite. Generally, kaolinite shows a southward increase in Makkah quadrangle while chlorite, as a minor component, shows a northward increase in Rabigh quadrangle.

Growth fluctuations in a class of deposition models

CERN Document Server

Balazs, M

2003-01-01

We compute the growth fluctuations in equilibrium of a wide class of deposition models. These models also serve as general frame to several nearest-neighbor particle jump processes, e.g. the simple exclusion or the zero range process, where our result turns to current fluctuations of the particles. We use martingale technique and coupling methods to show that, rescaled by time, the variance of the growth as seen by a deterministic moving observer has the form |V-C|*D, where V and C is the speed of the observer and the second class particle, respectively, and D is a constant connected to the equilibrium distribution of the model. Our main result is a generalization of Ferrari and Fontes' result for simple exclusion process. Law of large numbers and central limit theorem are also proven. We need some properties of the motion of the second class particle, which are known for simple exclusion and are partly known for zero range processes, and which are proven here for! a type of deposition models and also for a t...

Remote sensing and Aeromagnetic investigations in porphyry copper deposits for identification of areas with high concentration of gold: a case study from the central part of Dehaj-Sarduiyeh belt, Kerman, Iran

Directory of Open Access Journals (Sweden)

Mahdieh Hosseinjani Zadeh

2018-04-01

Full Text Available Introduction Remote sensing has shown tremendous potential in the identification of alteration zones. The importance of this science for mineral exploration and recognition of alteration zones with lower cost, time, and manpower is confirmed in many studies (Amer et al., 2012; Hosseinjani Zadeh et al., 2014; Tayebi and Tangestani, 2015; Shahriari et al., 2015. Gold is one of the byproducts in most of the porphyry copper deposits (PCDs. Although the gold assay is partly low and reaches between 0.012- 0.38 g/t in these deposits, the high tonnage of copper deposits provides a considerable source of gold which has an important economic value (Kerrich et al., 2000. Extension, intensity of alteration, assays and the type of mineralization vary in different deposits. For instance, many Au-poor porphyry copper deposits in southwest USA, Central Asia, and west of South America are associated with widespread phyllic alteration (Kesler et al., 2002. In addition, there is a positive correlation between gold and magnetite in PCDs (Kesler et al., 2002; Shafiei and Shahabpour, 2008; Sillitoe, 1979. Therefore, aeromagnetic investigation could be useful in identification of these deposits. The aim of this research is discrimination of alteration zones and investigation areas with high concentration of gold through processing of remote sensing and aeromagnetic data. Materials and methods A number of prone areas with different concentrations of gold in Dehaj-Sarduiyeh copper belt including Sar Kuh, Abdar, Meiduk, Sarcheshmeh, Darrehzar, Sara, Iju and Seridune were investigated using the processing of Advanced space borne thermal emission and reflection radiometer (ASTER, and aeromagnetic data. Pre-processing acts such as crosstalk correction and Internal Average Relative Reflection (IARR calibration were implemented on the ASTER data in order to remove noise and acquire surface reflectance. The alteration minerals were discriminated by implementation of

Properties of all YBa2Cu3O7 Josephson edge junctions prepared by in situ laser ablation deposition

International Nuclear Information System (INIS)

Koren, G.; Aharoni, E.; Polturak, E.; Cohen, D.

1991-01-01

Thin-film YBa 2 Cu 3 O 7 -YBa 2 Cu 3 O 7 edge junctions of 0.4x10 μm 2 cross section were prepared in situ by a multistep laser ablation deposition process. The fabrication time was about 3 h and the yield of good devices was 50%. Typical junctions reached zero resistance at 72 K and had a critical current density J c of 300 A/cm 2 at 70 K. Their J c as a function of temperature increased slowly with decreasing temperature down to 65 K and much faster below it. In the region of low J c we observed suppression of the critical current by a magnetic field. Under microwave radiation clear Shapiro steps were observed whose magnitude versus the microwave field agreed qualitatively with the resistively shunted junction model of a current biased junction

Atmospheric nitrogen deposition in the Yangtze River basin: Spatial pattern and source attribution

International Nuclear Information System (INIS)

Xu, Wen; Zhao, Yuanhong; Liu, Xuejun; Dore, Anthony J.; Zhang, Lin; Liu, Lei; Cheng, Miaomiao

2018-01-01

The Yangtze River basin is one of the world's hotspots for nitrogen (N) deposition and likely plays an important role in China's riverine N output. Here we constructed a basin-scale total dissolved inorganic N (DIN) deposition (bulk plus dry) pattern based on published data at 100 observational sites between 2000 and 2014, and assessed the relative contributions of different reactive N (N r ) emission sectors to total DIN deposition using the GEOS-Chem model. Our results show a significant spatial variation in total DIN deposition across the Yangtze River basin (33.2 kg N ha −1 yr −1 on average), with the highest fluxes occurring mainly in the central basin (e.g., Sichuan, Hubei and Hunan provinces, and Chongqing municipality). This indicates that controlling N deposition should build on mitigation strategies according to local conditions, namely, implementation of stricter control of N r emissions in N deposition hotspots but moderate control in the areas with low N deposition levels. Total DIN deposition in approximately 82% of the basin area exceeded the critical load of N deposition for semi-natural ecosystems along the basin. On the basin scale, the dominant source of DIN deposition is fertilizer use (40%) relative to livestock (11%), industry (13%), power plant (9%), transportation (9%), and others (18%, which is the sum of contributions from human waste, residential activities, soil, lighting and biomass burning), suggesting that reducing NH 3 emissions from improper fertilizer (including chemical and organic fertilizer) application should be a priority in curbing N deposition. This, together with distinct spatial variations in emission sector contributions to total DIN deposition also suggest that, in addition to fertilizer, major emission sectors in different regions of the basin should be considered when developing synergistic control measures. - Highlights: • Total DIN deposition fluxes showed a significant spatial variation in the

Seismic stratigraphy and late Quaternary shelf history, south-central Monterey Bay, California

Science.gov (United States)

Chin, J.L.; Clifton, H.E.; Mullins, H.T.

1988-01-01

The south-central Monterey Bay shelf is a high-energy, wave-dominated, tectonically active coastal region on the central California continental margin. A prominent feature of this shelf is a sediment lobe off the mouth of the Salinas River that has surface expression. High-resolution seismic-reflection profiles reveal that an angular unconformity (Quaternary?) underlies the entire shelf and separates undeformed strata above it from deformed strata below it. The Salinas River lobe is a convex bulge on the shelf covering an area of approximately 72 km2 in water depths from 10 to 90 m. It reaches a maximum thickness of 35 m about 2.5 km seaward of the river mouth and thins in all directions away from this point. Adjacent shelf areas are characterized by only a thin (2 to 5 m thick) and uniform veneer of sediment. Acoustic stratigraphy of the lobe is complex and is characterized by at least three unconformity-bounded depositional sequences. Acoustically, these sequences are relatively well bedded. Acoustic foresets occur within the intermediate sequence and dip seaward at 0.7?? to 2.0??. Comparison with sedimentary sequences in uplifted onshore Pleistocene marine-terrace deposits of the Monterey Bay area, which were presumably formed in a similar setting under similar processes, suggests that a general interpretation can be formulated for seismic stratigraphic patterns. Depositional sequences are interpreted to represent shallowing-upwards progradational sequences of marine to nonmarine coastal deposits formed during interglacial highstands and/or during early stages of falling sea level. Acoustic foresets within the intermediate sequence are evidence of seaward progradation. Acoustic unconformities that separate depositional sequences are interpreted as having formed largely by shoreface planation and may be the only record of the intervening transgressions. The internal stratigraphy of the Salinas River lobe thus suggests that at least several late Quaternary

Can mergers make slowly rotating elliptical galaxies

International Nuclear Information System (INIS)

White, S.D.M.

1979-01-01

The results of numerical experiments are used to guide an analytic discussion of hyperbolic mergers among an uncorrelated galaxy population. The expected merger rate is derived as a function of progenitor mass and relative angular momentum, and is used to predict the distribution of the parameter V/sub c//sigma 0 for merger products where V/sub c/ is the maximum observed rotation velocity in a galaxy and sigma 0 is its central velocity dispersion. The median value of this parameter for mergers between comparable galaxies is estimated to be 0.65 and is higher than the observed value in any of the 14 galaxies for which data are available. It seems unlikely that most elliptical galaxies are the result of single or multiple mergers between initially unbound stellar systems; further observational and theoretical work is suggested which should lead to a conclusive test of this picture. The present arguments cannot, however, exclude formation from low angular momentum elliptical orbits

Peat is regarded as slowly renewable biomass fuel

International Nuclear Information System (INIS)

Myllylae, I.

2000-01-01

The Finnish Ministry of Trade and Industry commissioned an investigation on the role of peat in Finnish greenhouse gas balance in 1999. An international scientist group, consisting of Dr. Patrick Crill from USA, Dr. Ken Hargreaves from United Kingdom and docent Atte Korhola from Finland conducted the investigation. The scientist group made the proposition that peat should be classified as a slowly renewable biomass fuel, which is significant from the peat industry's point of view. An interesting detail of the investigation was the calculations, which showed that ditching of peatlands, have decreased the methane emissions from peatlands. Virgin peatlands bind carbon dioxide from the air, but simultaneously they emit methane, which is more harmful than CO 2 emissions. The carbon sink effect of Finnish peatlands is based on the CO 2 binding of virgin and ditched peatlands in Finland. The CO 2 emissions of peat production and combustion are smaller than the CO 2 binding. Virgin peatlands form a relative large source of methane. The investigation shows that when reviewing the effects of all the greenhouse gases on climate, the virgin peatlands may accelerate the greenhouse effect due to the methane emissions. The final conclusion is that ditching of virgin peatlands has reduced the radiation enforcement in Finland in some extent. When a virgin peatland is ditched the methane emissions from it are reduced significantly, and simultaneously more CO 2 is bound into vegetation. According to the investigation the net emissions of greenhouse gases in Finland exceed 10 million tonnes calculated as CO 2 . Of this the share of virgin peatlands is 8.4 million tonnes, which is of the same magnitude as the emissions from peat combustion. The life cycle analysis has shown that peat production should be directed to swampy fields removed from agricultural production. In most of the cases the combination of reforestation and repaludification into a functional peatland ecosystem could

Phenolic acids as bioindicators of fly ash deposit revegetation.

Science.gov (United States)

Djurdjević, L; Mitrović, M; Pavlović, P; Gajić, G; Kostić, O

2006-05-01

The floristic composition, the abundance, and the cover of pioneer plant species of spontaneously formed plant communities and the content of total phenolics and phenolic acids, as humus constituents, of an ash deposit after 7 years of recultivation were studied. The restoration of both the soil and the vegetation on the ash deposits of the "Nikola Tesla-A" thermoelectric power plant in Obrenovac (Serbia) is an extremely slow process. Unfavorable physical and chemical characteristics, the toxicity of fly ash, and extreme microclimatic conditions prevented the development of compact plant cover. The abundance and cover of plants increased from the central part of the deposit towards its edges (ranging from 1-80%). Festuca rubra L., Crepis setosa Hall., Erigeron canadensis L., Cirsium arvense (L.) Scop., Calamagrostis epigeios (L.) Roth., and Tamarix gallica L. were the most abundant species, thus giving the highest cover. Humus generated during the decomposition process of plant remains represents a completely new product absent in the ash as the starting material. The amount of total phenolics and phenolic acids (38.07-185.16 microg/g of total phenolics and 4.12-27.28 microg/g of phenolic acids) in fly ash increased from the center of the deposit towards its edges in correlation with the increase in plant abundance and cover. Ash samples contained high amounts of ferulic, vanillic, and p-coumaric acid, while the content of both p-hydroxybenzoic and syringic acid was relatively low. The presence of phenolic acids indicates the ongoing process of humus formation in the ash, in which the most abundant pioneer plants of spontaneously formed plant communities play the main role. Phenolic compounds can serve as reliable bioindicators in an assessment of the success of the recultivation process of thermoelectric power plants' ash deposits.

Geologic map of the west-central Buffalo National River region, northern Arkansas

Science.gov (United States)

Hudson, Mark R.; Turner, Kenzie J.

2014-01-01

This map summarizes the geology of the west-central Buffalo National River region in the Ozark Plateaus region of northern Arkansas. Geologically, the region lies on the southern flank of the Ozark dome, an uplift that exposes oldest rocks at its center in Missouri. Physiographically, the map area spans the Springfield Plateau, a topographic surface generally held up by Mississippian cherty limestone and the higher Boston Mountains to the south, held up by Pennsylvanian rocks. The Buffalo River flows eastward through the map area, enhancing bedrock erosion of an approximately 1,600-ft- (490-m-) thick sequence of Ordovician, Mississippian, and Pennsylvanian carbonate and clastic sedimentary rocks that have been mildly deformed by a series of faults and folds. Quaternary surficial units are present as alluvial deposits along major streams, including a series of terrace deposits from the Buffalo River, as well as colluvium and landslide deposits mantling bedrock on hillslopes.

Geochronology, petrogenesis and tectonic settings of pre- and syn-ore granites from the W-Mo deposits (East Kounrad, Zhanet and Akshatau), Central Kazakhstan

Science.gov (United States)

Li, GuangMing; Cao, MingJian; Qin, KeZhang; Evans, Noreen J.; Hollings, Pete; Seitmuratova, Eleonora Yusupovha

2016-05-01

There is significant debate regarding the mineralization ages of the East Kounrad, Zhanet and Akshatau W-Mo deposits of Central Kazakhstan, and the petrogenesis and tectono-magmatic evolution of the granites associated with these deposits. To address these issues, we present molybdenite Re-Os dating, zircon U-Pb dating, whole rock geochemistry as well as Sr-Nd-Pb and zircon O-Hf isotopic analyses on the pre-mineralization and ore-forming granites. U-Pb dating of zircons from pre-mineralization granitic rocks yield Late Carboniferous ages of 320-309 Ma, whereas ore-forming granites have Early Permian ages of 298-285 Ma. Molybdenite Re-Os isotopic data indicate a mineralization age of 296 Ma at East Kounrad, 294 Ma at Akshatau and 285 Ma at Zhanet. The pre-ore and ore-forming granites are high-K calc-alkaline, metaluminous to slightly peraluminous I-type granites. The pre-mineralization granites are relatively unfractionated, whereas the ore-forming granites are highly fractionated. The fractionating mineral phases are probably K-feldspar, apatite, Ti-bearing phases and minor plagioclase. The pre-mineralization and ore-forming rocks are characterized by similar Sr-Nd-Pb-Hf-O isotopic compositions ((87Sr/86Sr)i = 0.70308-0.70501, εNd (t) = - 0.5 to + 2.8, 207Pb/204Pb = 15.60-15.82, zircon εHf (t) = + 1.2 to + 15.6 and δ18O = + 4.6 to + 10.3‰), whole rock TDMC (Nd) (840-1120 Ma) and zircon TDMC (Hf) (320-1240 Ma). The isotopic characteristics are consistent with a hybrid magma source caused by 10-30% assimilation of ancient crust by juvenile lower crust. The geochronology and geochemistry of these granites show that the Late Carboniferous pre-mineralization granitic rocks formed during subduction, whereas the Early Permian ore-forming, highly fractionated granite probably underwent significant fractionation with a restite assemblage of K-feldspar, apatite, Ti-bearing phases and minor plagioclase and developed during collision between the Yili and Kazakhstan

Murgabskaya Oblast, a promising gas region of Central Asia

Energy Technology Data Exchange (ETDEWEB)

Amanniyazov, K.N.; Abdyyev, A.A.

1981-01-01

Gas fields of the Murgabskiy region are multiple-bed. The industrial gas content is associated with the sandy-terrigenous formations of the Shatlyk productive level of the lower Goterivskiy stage. The gas formation is anticlinal, occasionally floating. A map is compiled for the dispersal of the Shatlyk level which isolates the lithological composition, thickness, zones of dispersal of sandstone, etc. A description is provided for the map plan of the Shatlyk level. Alternation of sandy-argillaceous and carbonate rocks created favorable prerequisites for the development in the deposits of the Neocomian of lithological-physical pairs of ''collectors-mantles'', the basis for trap formation in structures and zones of lithological substitution. Within the Murgabskiy region, the greatest outlook for discovering new gas fields is confined to the Shatlyk level. It is associated with the central part of the Murgabskiy Basin where major deposits have already been discovered. A group of structures in the eastern submersion of the Kopetdag trough at the junction of the Murgabskiy Basin is important. The structures at the junction of East Kopetdag and the Murgabskiy Basin may be promising. The outlook for possible gas is associated with deposits of the lower cretaceous and Sharaplinksiy level. The main task must be comprehensive in investigation of the suprasaline apt-Neocomian and Kimmeridgian-Tithonian deposits as possible multiple-bed gas and oil containing masses.

Increased spruce tree growth in Central Europe since 1960s.

Science.gov (United States)

Cienciala, Emil; Altman, Jan; Doležal, Jiří; Kopáček, Jiří; Štěpánek, Petr; Ståhl, Göran; Tumajer, Jan

2018-04-01

Tree growth response to recent environmental changes is of key interest for forest ecology. This study addressed the following questions with respect to Norway spruce (Picea abies, L. Karst.) in Central Europe: Has tree growth accelerated during the last five decades? What are the main environmental drivers of the observed tree radial stem growth and how much variability can be explained by them? Using a nationwide dendrochronological sampling of Norway spruce in the Czech Republic (1246 trees, 266 plots), novel regional tree-ring width chronologies for 40(±10)- and 60(±10)-year old trees were assembled, averaged across three elevation zones (break points at 500 and 700m). Correspondingly averaged drivers, including temperature, precipitation, nitrogen (N) deposition and ambient CO 2 concentration, were used in a general linear model (GLM) to analyze the contribution of these in explaining tree ring width variability for the period from 1961 to 2013. Spruce tree radial stem growth responded strongly to the changing environment in Central Europe during the period, with a mean tree ring width increase of 24 and 32% for the 40- and 60-year old trees, respectively. The indicative General Linear Model analysis identified CO 2 , precipitation during the vegetation season, spring air temperature (March-May) and N-deposition as the significant covariates of growth, with the latter including interactions with elevation zones. The regression models explained 57% and 55% of the variability in the two tree ring width chronologies, respectively. Growth response to N-deposition showed the highest variability along the elevation gradient with growth stimulation/limitation at sites below/above 700m. A strong sensitivity of stem growth to CO 2 was also indicated, suggesting that the effect of rising ambient CO 2 concentration (direct or indirect by increased water use efficiency) should be considered in analyses of long-term growth together with climatic factors and N-deposition

Micropaleontologic record of Quaternary paleoenvironments in the Central Albemarle Embayment, North Carolina, U.S.A.

Science.gov (United States)

Culver, Stephen J.; Farrell, Kathleen M.; Mallinson, David J.; Willard, Debra A.; Horton, Benjamin P.; Riggs, Stanley R.; Thieler, E. Robert; Wehmiller, John F.; Parham, Peter; Snyder, Scott W.; Hillier, Caroline

2011-01-01

To understand the temporal and spatial variation of eustatic sea-level fluctuations, glacio-hydro-isostacy, tectonics, subsidence, geologic environments and sedimentation patterns for the Quaternary of a passive continental margin, a nearly complete stratigraphic record that is fully integrated with a three dimensional chronostratigraphic framework, and paleoenvironmental information are necessary. The Albemarle Embayment, a Cenozoic regional depositional basin in eastern North Carolina located on the southeast Atlantic coast of the USA, is an ideal setting to unravel these dynamic, interrelated processes.Micropaleontological data, coupled with sedimentologic, chronostratigraphic and seismic data provide the bases for detailed interpretations of paleoenvironmental evolution and paleoclimates in the 90. m thick Quaternary record of the Albemarle Embayment. The data presented here come from a transect of cores drilled through a barrier island complex in the central Albemarle Embayment. This area sits in a ramp-like setting between late Pleistocene incised valleys.The data document the episodic infilling of the Albemarle Embayment throughout the Quaternary as a series of transgressive-regressive (T-R) cycles, characterized by inner shelf, midshelf, and shoreface assemblages, that overlie remnants of fluvial to estuarine valley-fill. Barrier island and marginal marine deposits have a low preservation potential. Inner to mid-shelf deposits of the early Pleistocene are overlain by similar middle Pleistocene shelf sediments in the south of the study area but entirely by inner shelf deposits in the north. Late Pleistocene marine sediments are of inner shelf origin and Holocene deposits are marginal marine in nature. Pleistocene marine sediments are incised, particularly in the northern half of the embayment by lowstand paleovalleys, partly filled by fluvial/floodplain deposits and in some cases, overlain by remnants of transgressive estuarine sediments. The shallowing

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 ...

Mapping Aquifer Systems with Airborne Electromagnetics in the Central Valley of California

Science.gov (United States)

Knight, R. J.; Smith, R.; Asch, T. H.; Abraham, J.; Cannia, J.; Fogg, G. E.; Viezzoli, A.

2016-12-01

The Central Valley of California is an important agricultural region struggling to meet the need for irrigation water. Recent periods of drought have significantly reduced the delivery of surface water, resulting in extensive pumping of groundwater. This has exacerbated an already serious problem in the Central Valley, where a number of areas have experienced declining water levels for several decades leading to ongoing concerns about depletion of aquifers and impacts on ecosystems, as well as subsidence of the ground surface. The overdraft has been so significant, that there are now approximately140 million acre-feet (MAF) of unused groundwater storage in the Central Valley, storage that could be used to complement the 42 MAF of surface storage. The alluvial sedimentary geology of the Central Valley is typically composed of more than 50 to 70 percent fine-grained deposits dominated by silt and clay beds. These fine grained deposits can block potential recharge, and are associated with the large amount of observed subsidence. Fortunately, the geologic processes that formed the region created networks of sand and gravel which provide both a supply of water and pathways for recharge from the surface to the aquifers. The challenge is to find these sand and gravel deposits and thus identify optimal locations for surface spreading techniques so that recharge could be dramatically increased, and re-pressurization of the confined aquifer networks could be accomplished. We have acquired 100 line kilometers of airborne electromagnetic data over an area in the San Joaquin Valley, imaging the subsurface hydrostratigraphy to a depth of 500 m with spatial resolution on the order of meters to tens of meters. Following inversion of the data to obtain resistivity models along the flight lines, we used lithology logs in the area to transform the models to images displaying the distribution of sand and gravel, clay, and mixed fine and coarse materials. The quality of the data and

Overview of erosion–deposition diagnostic tools for the ITER-Like Wall in the JET tokamak

International Nuclear Information System (INIS)

Rubel, M.; Coad, J.P.; Widdowson, A.; Matthews, G.F.; Esser, H.G.; Hirai, T.; Likonen, J.; Linke, J.; Lungu, C.P.; Mayer, M.; Pedrick, L.; Ruset, C.

2013-01-01

This paper presents scientific and technical issues related to the development of erosion–deposition diagnostic tools for JET operated with the ITER-Like Wall: beryllium and tungsten marker tiles and several types of wall probes installed in the main chamber and in the divertor. Markers tiles are the standard limiter and divertor components additionally coated first with a thin sandwich of Ni–Be and Mo–W for, beryllium and tungsten markers, respectively. Both types of markers are embedded in regular arrays of limiter and divertor tiles. Coated W–Be probes are also inserted in the Be-covered Inconel cladding tiles on the central column. Other types of erosion–deposition diagnostic tools are: rotating collectors, deposition traps, louver clips, quartz microbalance and mirrors for the First Mirror Test at JET for ITER. The specific role of these tools is discussed in detail

Volcanogenic Massive Sulfide Deposits of the World - Database and Grade and Tonnage Models