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Sample records for athabasca deposit

  1. Unconformity-related uranium deposits, Athabasca area, Saskatchewan, and East Alligator Rivers area, Northern Territory, Australia

    International Nuclear Information System (INIS)

    Most unconformity-type uranium deposits in Saskatchewan occur within a few tens of metres above and/or below the basal unconformity of the 1.45 b.y. Athabasca Sandstone. Graphitic basement rocks coincident with post-Athabasca faulting or brecciation at or near the unconformity are important in localizing uranium deposits which form as tabular, ribbon-like bodies with grades averaging over 2 percent uranium and containing up to 50,000 tonnes U3O8. Some of these deposits have similar contents of nickel and arsenic. In the genetic model used to explain these deposits, traces of uranium were leached from the sandstone and basement rocks by oxidized formation waters. A thick clay regolith absorbed uranium from the solution, and the fixed uranium was reduced through an indirect reaction with graphite. The clay mineral surfaces were thus continuously cleared to allow further adsorption. Fluid convection was induced by topographic relief and/or crustal heating from radioactive decay, and would continue uranium deposition until all permeability was plugged by minerals. The East Alligator Rivers uranium deposits in Northern Territory, Australia occur within Middle Proterozoic quartz-chlorite and quartz-muscovite schists overlain by sandstone. Highest grades occur in silicified breccias where carbonate beds were leached out. Mineralization ages are both pre- and post-Kombolgie Sandstone, but, to date, no significant uranium mineralization has been found in the sandstone. There are many similarities with Saskatchewan deposits, but also important differences. (auth)

  2. Geology of the uranium deposits related to the sub-Athabasca unconformity, Saskatchewan

    International Nuclear Information System (INIS)

    The Athabasca Basin is a large, oval, dish-shaped structure, 425 km by 225 km (80 000 km2) containing about 1500 m of mainly flat-lying quartz-rich sandstone of the Athabasca Group. The basin lies with marked angular unconformity across a Hudsonian basement of deformed and metamorphosed Archean and Aphebian sedimentary, volcanic and plutonic rocks trending north to northeast beneath the basin. In the Carswell Circular Structure in the central western half of the basin rocks are brought to surface through 1200 m of sandstone. The rocks of the basin are less than one percent exposed. Overburden locally reaches 90 m thick. Uranium deposits have been found near the southeast edge of the basin, within the Carswell Circular Structure, and along the northern rim of the basin. They are (1) at the unconformity as high-grade masses elongated in and parallel to major faults, hosted mainly in highly-altered white clay feldspar-rich basement rocks and associated with graphitic metasediments and calc-silicate rocks; (2) within the first 40 m above the unconformity in grey to black and multicoloured Athabasca sandstones and shales as a coating on quartz grains, as disseminations in the clay matrix and as veins; and (3) within 100 m below the unconformity as fracture fillings and disseminations in basement rocks

  3. Atmospheric deposition of mercury and methylmercury to landscapes and waterbodies of the Athabasca oil sands region.

    Science.gov (United States)

    Kirk, Jane L; Muir, Derek C G; Gleason, Amber; Wang, Xiaowa; Lawson, Greg; Frank, Richard A; Lehnherr, Igor; Wrona, Fred

    2014-07-01

    Atmospheric deposition of metals originating from a variety of sources, including bitumen upgrading facilities and blowing dusts from landscape disturbances, is of concern in the Athabasca oil sands region of northern Alberta, Canada. Mercury (Hg) is of particular interest as methylmercury (MeHg), a neurotoxin which bioaccumulates through foodwebs, can reach levels in fish and wildlife that may pose health risks to human consumers. We used spring-time sampling of the accumulated snowpack at sites located varying distances from the major developments to estimate winter 2012 Hg loadings to a ∼20 000 km(2) area of the Athabasca oil sands region. Total Hg (THg; all forms of Hg in a sample) loads were predominantly particulate-bound (79 ± 12%) and increased with proximity to major developments, reaching up to 1000 ng m(-2). MeHg loads increased in a similar fashion, reaching up to 19 ng m(-2) and suggesting that oil sands developments are a direct source of MeHg to local landscapes and water bodies. Deposition maps, created by interpolation of measured Hg loads using geostatistical software, demonstrated that deposition resembled a bullseye pattern on the landscape, with areas of maximum THg and MeHg loadings located primarily between the Muskeg and Steepbank rivers. Snowpack concentrations of THg and MeHg were significantly correlated (r = 0.45-0.88, p < 0.01) with numerous parameters, including total suspended solids (TSS), metals known to be emitted in high quantities from the upgraders (vanadium, nickel, and zinc), and crustal elements (aluminum, iron, and lanthanum), which were also elevated in this region. Our results suggest that at snowmelt, a complex mixture of chemicals enters aquatic ecosystems that could impact biological communities of the oil sands region.

  4. Snowpack deposition of trace elements in the Athabasca oil sands region, Canada.

    Science.gov (United States)

    Guéguen, C; Cuss, C W; Cho, S

    2016-06-01

    The total recoverable and dissolved concentrations of 29 metals and metalloids were analyzed in snowpack collected at 91 sites in the Athabasca oil sands region, Canada in winter 2011. Based on deposition pattern from geographical centre, three groups were found: Type-1 metals (i.e. dissolved and total recoverable V; Mo) showed a significant exponential decrease with distance, suggesting oil sands development sources; Type-2 elements (e.g. Al, Sb, As, Ba, Fe, Ni, Tl, and Ti and Zn) showed exponentially decline patterns but with some local point sources; Type-3 elements (e.g. Cd, Cl, Cr, Mn, Sr and Th) deposition pattern represented local sources. A self-organizing map showed that sites with the highest elemental concentrations (Cluster I) were mainly located in the vicinity of upgrading facilities and along the north-south transects. The lowest elemental concentration sites (Cluster III) were the most distal sites or located in the western region of the study area. PMID:27031808

  5. Nitrogen and sulphur deposition and the growth of Sphagnum fuscum in bogs of the Athabasca Oil Sands Region, Alberta

    Directory of Open Access Journals (Sweden)

    Melanie A. VILE

    2010-08-01

    Full Text Available One of the consequences of ongoing development of the oil sands reserve in the Athabasca Oil Sands Region (AOSR near Fort McMurray, Alberta, Canada (56° 39' N, 111° 13' W is an increase in emissions of nitrogen (N and sulphur (S, with an attendant increases in regional atmospheric N and S deposition. Regional land cover across northeastern Alberta is a mixture of Boreal Mixedwood, Boreal Highlands, and Subarctic areas. Peatlands occupy between 22 and 66% of these natural regions, and the land cover of bogs varies between 6.7% in the Mixedwood Region to 46% in the Subarctic Region. Ombrotrophic bog ecosystems may be especially sensitive to atmospheric deposition of N and S. Across 10 ombrotrophic bog sites in the AOSR over four years (2005– 2008, we found no evidence of elevated deposition of NH4 +-N, NO3 –-N, total inorganic nitrogen (TIN; NH4 +-N plus NO3 –-N, or SO4 2–-S, with values measured using ion exchange resin collectors averaging 0.61 ± 04, 0.20 ± 0.01, 0.81 ± 0.04, and 1.14 ± 0.06 kg ha–1 y–1, respectively. Vertical growth and net primary production of Sphagnum fuscum, an indicator of elevated deposition, did not differ consistently across sites, averaging 11.8 ± 0.2 mm y–1 and 234 ± 3.3 g m–2 y–1, respectively, over the four years. Neither vertical growth nor net primary production of S. fuscum was correlated with growing season atmospheric N or S deposition. Our data provide a valuable benchmark of background values for monitoring purposes in anticipation of increasing N and S deposition over a broader geographic region within the AOSR.

  6. Fluids preserved in variably altered graphitic pelitic schists in the Dufferin Lake Zone, south-central Athabasca Basin, Canada: implications for graphite loss and uranium deposition

    Science.gov (United States)

    Pascal, Marjolaine; Boiron, Marie-Christine; Ansdell, Kevin; Annesley, Irvine R.; Kotzer, Tom; Jiricka, Dan; Cuney, Michel

    2016-06-01

    The Athabasca Basin (Canada) contains the highest grade unconformity-type uranium deposits in the world. Underlying the Athabasca Group sedimentary rocks of the Dufferin Lake Zone are variably graphitic, pelitic schists (VGPS), altered to chlorite and hematite (Red/Green Zone: RGZ). They were locally bleached near the unconformity during paleoweathering and/or later fluid interaction. Overall, graphite was lost from the RGZ and the bleached zone relative to the original VGPS. Fluid inclusions were examined in different generations of quartz veins, using microthermometry and Raman spectroscopy, to characterize and compare the different fluids that interacted with the RGZ and the VGPS. In the VGPS, CH4-, and N2-rich fluid inclusions, which homogenize into the vapor phase between -100 and -74 °C, and -152 and -125 °C, respectively, and CO2-rich fluid inclusions, homogenizing either into vapor or liquid between 20 and 28 °C, are present. Carbonic fluids could be the result of the breakdown of graphite to CH4 + CO2, whereas N2-rich fluid is interpreted to be the result of breakdown of feldspars/micas to NH4 ++N2. In the RGZ, the presence of fluid inclusions with low ice melting temperature (-38 to -16 °C) reflect the presence of CaCl2, and fluid inclusions with halite daughter minerals that dissolve between 190 and 240 °C indicate the presence of highly saline fluids. These fluids are interpreted to be derived from the Athabasca Basin. The circulation of carbonic fluids and brines occurred during two different events related to different P-T conditions of trapping. The carbonic fluids interacted with basement rocks during retrograde metamorphism of the basement rocks before deposition of the Athabasca Basin, whereas the brines circulated after the deposition of the Athabasca Basin. These latter fluids are similar to brines related to uranium mineralization at McArthur River and thus, in addition to possibly being related to graphite depletion in the RGZ, they could

  7. Oil sands development and its impact on atmospheric wet deposition of air pollutants to the Athabasca Oil Sands Region, Alberta, Canada.

    Science.gov (United States)

    Lynam, Mary M; Dvonch, J Timothy; Barres, James A; Morishita, Masako; Legge, Allan; Percy, Kevin

    2015-11-01

    Characterization of air pollutant deposition resulting from Athabasca oil sands development is necessary to assess risk to humans and the environment. To investigate this we collected event-based wet deposition during a pilot study in 2010-2012 at the AMS 6 site 30 km from the nearest upgrading facility in Fort McMurray, AB, Canada. Sulfate, nitrate and ammonium deposition was (kg/ha) 1.96, 1.60 and 1.03, respectively. Trace element pollutant deposition ranged from 2 × 10(-5) - 0.79 and exhibited the trend Hg oil sands development, urban activities and forest fires were deposited. High deposition of the elements Sr, Mn, Fe and Mg which are tracers for soil and crustal dust implies land-clearing, mining and hauling emissions greatly impacted surrounding human settlements and ecosystems. PMID:26277649

  8. A multi-isotope approach for estimating industrial contributions to atmospheric nitrogen deposition in the Athabasca oil sands region in Alberta, Canada

    International Nuclear Information System (INIS)

    Industrial nitrogen (N) emissions in the Athabasca oil sands region (AOSR), Alberta, Canada, affect nitrate (NO3) and ammonium (NH4) deposition rates in close vicinity of industrial emitters. NO3–N and NH4–N open field and throughfall deposition rates were determined at various sites between 3 km and 113 km distance to the main oil sand operations between May 2008 and May 2009. NO3 and NH4 were analyzed for δ15N–NO3, δ18O–NO3, Δ17O–NO3 and δ15N–NH4. Marked differences in the δ18O and Δ17O values between industrial emissions and background deposition allowed for the estimation of minimum industrial contributions to atmospheric NO3 deposition. δ15N–NH4 values also allowed for estimates of industrial contributions to atmospheric NH4 deposition. Results revealed that particularly sites within ∼30 km radius from the main oil sands developments are significantly affected by industrial contributions to atmospheric NO3 and NH4 deposition. -- Highlights: •Atmospheric NO3 and NH4 deposition rates are elevated near industrial emitters. •δ18O and Δ17O values of NO3 at high N deposition sites are isotopically distinct. •Industrial contributions to NO3 deposition are estimated using δ18O and Δ17O values. •Elevated δ15N values of NO3 and NH4 deposition indicate industrial contributions. -- Distinct δ18O, Δ17O, and δ15N values were used to estimate industrially derived N contributions to atmospheric nitrate and ammonium deposition in the Athabasca oil sands region

  9. Oil sands development and its impact on atmospheric wet deposition of air pollutants to the Athabasca Oil Sands Region, Alberta, Canada.

    Science.gov (United States)

    Lynam, Mary M; Dvonch, J Timothy; Barres, James A; Morishita, Masako; Legge, Allan; Percy, Kevin

    2015-11-01

    Characterization of air pollutant deposition resulting from Athabasca oil sands development is necessary to assess risk to humans and the environment. To investigate this we collected event-based wet deposition during a pilot study in 2010-2012 at the AMS 6 site 30 km from the nearest upgrading facility in Fort McMurray, AB, Canada. Sulfate, nitrate and ammonium deposition was (kg/ha) 1.96, 1.60 and 1.03, respectively. Trace element pollutant deposition ranged from 2 × 10(-5) - 0.79 and exhibited the trend Hg < Se < As < Cd < Pb < Cu < Zn < S. Crustal element deposition ranged from 1.4 × 10(-4) - 0.46 and had the trend: La < Ce < Sr < Mn < Al < Fe < Mg. S, Se and Hg demonstrated highest median enrichment factors (130-2020) suggesting emissions from oil sands development, urban activities and forest fires were deposited. High deposition of the elements Sr, Mn, Fe and Mg which are tracers for soil and crustal dust implies land-clearing, mining and hauling emissions greatly impacted surrounding human settlements and ecosystems.

  10. Micrometer scale carbon isotopic study of bitumen associated with Athabasca uranium deposits: Constraints on the genetic relationship with petroleum source-rocks and the abiogenic origin hypothesis

    Science.gov (United States)

    Sangély, L.; Chaussidon, M.; Michels, R.; Brouand, M.; Cuney, M.; Huault, V.; Landais, P.

    2007-06-01

    In situ analytical techniques - Fourier transform infrared microspectroscopy (μFTIR) and ion microprobe - have been used to unravel the origin of solid bitumen associated with the uranium deposits of Athabasca (Saskatchewan, Canada). Both aliphaticity and carbon isotopic compositions within the samples are heterogeneous but spatially organized in concentric zonations at the micrometer scale. Finally, the δ13C values are positively correlated to the aliphatic contents over an extremely large isotopic range from ˜ - 49‰ to ˜ - 31‰. We infer that this positive correlation may be related to the carbon isotopic fractionations associated with the synthesis of bitumen through the catalytic hydrogenation of CO 2, rather than the result of pre-existing petroleum product precipitation and/or alteration (such as radiolysis). This explanation is consistent with (i) published results of abiogenic synthesis experiments, in which the differences in δ13C values between saturated and unsaturated hydrocarbons range from + 2 and + 19‰, in contrast to the differences systematically observed in conventional bitumen and petroleum ranging from 0‰ to - 4‰; (ii) the absence of a similar positive correlation between aliphatic contents and δ13C values in the other bitumen analyzed in the present study, for which a biogenic origin has been unequivocally established (samples from Oklo, Gabon, and Lodève, France, uranium deposits); (iii) the presence of CO 2 and H 2 in the gas-phase of fluid inclusions in the Athabasca uranium deposits, H 2 resulting from water radiolysis. The present results suggest that the δ13C vs. aliphaticity correlation could be used as a criterion to discriminate between abiogenic vs. biogenic origin of macromolecular organic matter.

  11. A rapid in situ method for determining the ages of uranium oxide minerals: Evolution of the Cigar Lake deposit, Athabasca Basin

    International Nuclear Information System (INIS)

    The authors present a rapid and accurate technique for making in situ U-Pb isotopic measurements of uranium oxide minerals that utilizes both electron and ion microprobes. U and Pb concentrations are determined using an electron microprobe, whereas the isotopic composition of Pb for the same area is measured using a high-resolution ion microprobe. The advantages of this approach are: mineral separation and chemical digestion are unnecessary; homogeneous uranium oxide standards, which are difficult to obtain, are not required; and precise and accurate U-Pb ages on ∼10 microm spots can be obtained in a matter of hours. The authors have applied their method to study the distribution of U-Pb ages in complexly intergrown uranium oxides from the unconformity-type Cigar Lake uranium deposit, Saskatchewan, Canada. In situ U-Pb results from early formed uraninite define a well-correlated array on concordia with upper and lower intercepts of 1,467 ± 63 Ma and 443 ± 96 Ma (±1σ), respectively. The 1,467 Ma age is interpreted as the minimum age of mineralization and is consistent with the age of clay-mineral alteration (approximately1477 Ma) and magnetization of diagenetic hematite (1,650 to 1,450 Ma) that is associated with these unconformity-type uranium deposits and early diagenesis of the Athabasca Basin sediments. In situ U-Pb isotopic analysis of uraninite and coffinite can document the Pb*/U heterogeneities that can occur on a scale of 15 to 30 microm, thus providing relatively accurate information regarding the timing of fluid interactions associated with the evolution of these deposits

  12. The importance of atmospheric base cation deposition for preventing soil acidification in the Athabasca Oil Sands Region of Canada.

    Science.gov (United States)

    Watmough, Shaun A; Whitfield, Colin J; Fenn, Mark E

    2014-09-15

    Industrial activities in the oil sands region of Alberta, Canada have resulted in greatly elevated emissions of SO2 and N (NO(x) and NH3) and there are concerns over possible widespread ecosystem acidification. Acid sensitive soils in the region are common and have very low base cation weathering rates: the median base cation weathering rate estimated for 63 sites using PROFILE was just 17 mmol cm(-2) yr(-1). Deposition of S and N in throughfall was approximately twice as high as deposition measured with open collectors and could be as high as 360 mmol cm(-2) yr(-1) within 20 km of the main industrial center, although deposition declined logarithmically with distance from the industrial activities. Base cation deposition however, mostly exceeded the combined inputs of S and N in bulk deposition and throughfall, particularly during the summer months. The potential for soil acidification at a site close (deposition at the site, soil base saturation and soil solution pH and molar Ca:Al ratio were predicted to increase in the future assuming acid and base cation deposition constant at current rates. This work shows that despite extremely low soil base cation weathering rates in the region, the risk of soil acidification is mitigated to a large extent by high base cation deposition, which in contrast to S emissions is derived from fugitive dust sources in the mines, and is poorly quantified for regional modeling studies.

  13. Athabasca asphaltene structures

    Energy Technology Data Exchange (ETDEWEB)

    Dettman, H.; Salmon, S.; Zinz, D. [National Centre for Upgrading Technology, Devon, AB (Canada)

    2009-07-01

    In order to model petroleum behaviour during production and refining processes, it is important to understand the molecular character of oil components. Gas chromatography can be used to separate components with boiling points less than 524 degrees C. However, since asphaltenes have a higher boiling point, gel permeation chromatography (GPC) must be used to separate species before analysis. Analysis of Athabasca asphaltene GPC fractions has shown that asphaltenes consist of 2 types of species, notably crunchy species that are graphitic in appearance, and oily species. The molecular weights range from 400 to 2000 g/mole as measured by low resolution mass spectrometry. This poster described the ongoing effort to separate the asphaltenes by polarity. Athabasca asphaltenes were subfractioned into 4 parts according to differential solubility in pentane and centrifugation. Acidic species were isolated from the asphaltenes using adsorption chromatography. The 4 polarity fractions and acid species have been characterized with particular reference to elemental and metals content. Analyses were performed by Fourier transform infrared (FTIR) and nuclear magnetic resonance (NMR) carbon type analyses. This poster provided comparisons of their elution profiles by GPC. tabs., figs.

  14. Market outlook for Athabasca bitumen: the economics of location

    International Nuclear Information System (INIS)

    The use of steam assisted gravity drainage (SAGD) was shown to have lowered supply costs and made Athabasca bitumen competitive in the North American market for heavy crudes and bitumen. As part of a SAGD commercialization study, the potential market for Athabasca bitumen, its transportation and netback prices were studied. While both Syncrude and Suncor have identified a need for additional bitumen in the future, it was also recognized that Athabasca bitumen prices must be cost competitive with Syncrude's and Suncor's own products. The study also revealed that the most significant obstacle for Athabaska bitumen to being fully competitive in the North American market was the lack of transportation infrastructure. It was suggested that using larger volume pipelines would aid in keeping pipeline tariffs low , which in turn, would improve Athabaska bitumen's competitiveness and enable further development of the deposit. 8 figs., 1 table

  15. Receptor Modeling of Epiphytic Lichens to Elucidate the Sources and SpatialDistribution of Inorganic Air Pollution in the Athabasca Oil Sands Region

    Science.gov (United States)

    The contribution of inorganic air pollutant emissions to atmospheric deposition in the Athabasca Oil Sands Region (AOSR) of Alberta, Canada was investigated in the surrounding boreal forests, using a common epiphytic lichen bio-indicator species (Hypogymnia physodes) and applyi...

  16. Has Alberta oil sands development altered delivery of polycyclic aromatic compounds to the Peace-Athabasca Delta?

    Directory of Open Access Journals (Sweden)

    Roland I Hall

    Full Text Available BACKGROUND: The extent to which Alberta oil sands mining and upgrading operations have enhanced delivery of bitumen-derived contaminants via the Athabasca River and atmosphere to the Peace-Athabasca Delta (200 km to the north is a pivotal question that has generated national and international concern. Accounts of rare health disorders in residents of Fort Chipewyan and deformed fish in downstream ecosystems provided impetus for several recent expert-panel assessments regarding the societal and environmental consequences of this multi-billion-dollar industry. Deciphering relative contributions of natural versus industrial processes on downstream supply of polycyclic aromatic compounds (PACs has been identified as a critical knowledge gap. But, this remains a formidable scientific challenge because loading from natural processes remains unknown. And, industrial activity occurs in the same locations as the natural bitumen deposits, which potentially confounds contemporary upstream-downstream comparisons of contaminant levels. METHODS/PRINCIPAL FINDINGS: Based on analyses of lake sediment cores, we provide evidence that the Athabasca Delta has been a natural repository of PACs carried by the Athabasca River for at least the past two centuries. We detect no measureable increase in the concentration and proportion of river-transported bitumen-associated indicator PACs in sediments deposited in a flood-prone lake since onset of oil sands development. Results also reveal no evidence that industrial activity has contributed measurably to sedimentary concentration of PACs supplied by atmospheric transport. CONCLUSIONS/SIGNIFICANCE: Findings suggest that natural erosion of exposed bitumen in banks of the Athabasca River and its tributaries is a major process delivering PACs to the Athabasca Delta, and the spring freshet is a key period for contaminant mobilization and transport. This baseline environmental information is essential for informed management

  17. Isotopic Evidence for Oil Sands Petroleum Coke in the Peace-Athabasca Delta.

    Science.gov (United States)

    Jautzy, Josué J; Ahad, Jason M E; Gobeil, Charles; Smirnoff, Anna; Barst, Benjamin D; Savard, Martine M

    2015-10-20

    The continued growth of mining and upgrading activities in Canada's Athabasca oil sands (AOS) region has led to concerns about emissions of contaminants such as polycyclic aromatic hydrocarbons (PAHs). Whereas a recent increase in PAH emissions has been demonstrated within around 50 km of the main center of surface mining and upgrading operations, the exact nature of the predominant source(s) and the geographical extent of the deposition are still under debate. Here, we report a century-long source apportionment of PAHs using dual (δ(2)H, δ(13)C) compound-specific isotope analysis on phenanthrene deposited in a lake from the Athabasca sector of the Peace-Athabasca Delta situated ∼150 km downstream (north) of the main center of mining operations. The isotopic signatures in the core were compared to those of the main potential sources in this region (i.e., unprocessed AOS bitumen, upgrader residual coke, forest fires, coal, gasoline and diesel soot). A significant concurrent increase (∼55.0‰) in δ(2)H and decrease (∼1.5‰) in δ(13)C of phenanthrene over the last three decades pointed to an increasingly greater component of petcoke-derived PAHs. This study is the first to quantify long-range (i.e., >100 km) transport of a previously under-considered anthropogenic PAH source in the AOS region.

  18. Isotopic Evidence for Oil Sands Petroleum Coke in the Peace-Athabasca Delta.

    Science.gov (United States)

    Jautzy, Josué J; Ahad, Jason M E; Gobeil, Charles; Smirnoff, Anna; Barst, Benjamin D; Savard, Martine M

    2015-10-20

    The continued growth of mining and upgrading activities in Canada's Athabasca oil sands (AOS) region has led to concerns about emissions of contaminants such as polycyclic aromatic hydrocarbons (PAHs). Whereas a recent increase in PAH emissions has been demonstrated within around 50 km of the main center of surface mining and upgrading operations, the exact nature of the predominant source(s) and the geographical extent of the deposition are still under debate. Here, we report a century-long source apportionment of PAHs using dual (δ(2)H, δ(13)C) compound-specific isotope analysis on phenanthrene deposited in a lake from the Athabasca sector of the Peace-Athabasca Delta situated ∼150 km downstream (north) of the main center of mining operations. The isotopic signatures in the core were compared to those of the main potential sources in this region (i.e., unprocessed AOS bitumen, upgrader residual coke, forest fires, coal, gasoline and diesel soot). A significant concurrent increase (∼55.0‰) in δ(2)H and decrease (∼1.5‰) in δ(13)C of phenanthrene over the last three decades pointed to an increasingly greater component of petcoke-derived PAHs. This study is the first to quantify long-range (i.e., >100 km) transport of a previously under-considered anthropogenic PAH source in the AOS region. PMID:26404505

  19. Ambient air quality observations in the Athabasca oil sands region

    International Nuclear Information System (INIS)

    Both Syncrude and Suncor have plans to develop new oil sands leases and to increase crude oil and bitumen recovery in the Athabasca oil sands region. In recognition of the effects that this will have on the environment, Suncor has proposed modifications to reduce SO2 emissions to the atmosphere, while Syncrude plans to develop additional ambient air quality, sulphur deposition and biomonitoring programs. This report discussed the ambient air quality monitoring that was undertaken in the Fort McMurray-Fort McKay airshed. Twelve continuous ambient air quality stations and 76 passive monitoring stations are maintained in the region. Environment Canada maintains eight precipitation monitoring stations in northern Alberta and Saskatchewan. Source characterization, ambient air quality and meteorology observations, air quality monitoring, and air quality data from continuous sulphur dioxide, hydrogen sulphide, nitrogen oxides, ozone, carbon monoxide, hydrocarbon, acid rain and particulates analyzers were reviewed. The documentation of all computer files used for the analysis of the air quality data is discussed in the Appendix. 47 refs., 39 tabs., 53 figs

  20. Open Technologies at Athabasca University's Geospace Observatories

    Science.gov (United States)

    Connors, M. G.; Schofield, I. S.

    2012-12-01

    Athabasca University Geophysical Observatories feature two auroral observation sites situated in the subauroral zone of western Canada, separated by approximately 25 km. These sites are both on high-speed internet and ideal for observing phenomena detectable from this latitude, which include noctilucent clouds, meteors, and magnetic and optical aspects of the aurora. General aspects of use of Linux in observatory management are described, with emphasis on recent imaging projects involving control of high resolution digital SLR cameras at low cadence, and inexpensive white light analog video cameras at 30 Hz. Linux shell scripts are extensively used, with image capture controlled by gphoto2, the ivtv-utils package, x264 video coding library, and ffmpeg. Imagemagick allows processing of images in an automated fashion. Image archives and movies are created and can be correlated with magnetic data. Much of the magnetic data stream also uses GMT (Generic Mapping Tools) within shell scripts for display. Additionally, SPASE metadata are generated for most of the magnetic data, thus allowing users of our AUTUMN magnetic data repository to perform SPASE queries on the dataset. Visualization products from our twin observatories will be presented.

  1. Source Apportionment of Background PAHs in the Peace-Athabasca Delta (Alberta, Canada) Using Molecular Level Radiocarbon Analysis.

    Science.gov (United States)

    Jautzy, Josué J; Ahad, Jason M E; Hall, Roland I; Wiklund, Johan A; Wolfe, Brent B; Gobeil, Charles; Savard, Martine M

    2015-08-01

    The downstream accumulation of polycyclic aromatic hydrocarbons (PAHs) in the Peace-Athabasca Delta (PAD), an ecologically important landscape, is a key issue of concern given the rapid development of the oil sands industry in Northern Alberta, Canada. In addition to PAHs derived from industrial activity (i.e., oil sands mining) within the Athabasca watershed, however, forest fires and erosion of fossil fuel deposits within both the Athabasca and Peace watersheds are two potentially important natural sources of PAHs delivered to the PAD. Consequently, evaluating the environmental impact of mining activities requires a quantitative understanding of natural, background PAHs. Here, we utilize molecular-level natural-abundance radiocarbon measurements on an amalgamated sediment record from a Peace River flood-susceptible oxbow lake in the northern Peace sector of the PAD to quantitatively discriminate sources of naturally occurring alkylated PAHs (fossil and modern biomass). A radiocarbon mass balance quantified a predominantly natural petrogenic source (93% petrogenic, 7% forest fire) for alkylated PAHs during the past ∼50 years. Additionally, a significant petrogenic component determined for retene, a compound usually considered a biomarker for softwood combustion, suggests that its use as a unique forest fire indicator may not be suitable in PAD sediments receiving Peace watershed-derived fluvial inputs. PMID:26115178

  2. Syncrude's Aurora Mine : the key to future Athabasca oil sands development

    International Nuclear Information System (INIS)

    Syncrude's newest mine, the Aurora mine is located 35 km northeast of Syncrude's existing Mildred Lake plant, across the Athabasca River. It has a potential to produce more than 2.5 billion barrels of bitumen. Aurora will eventually consist of two surface mines, the Aurora North and Aurora South. Mining and extraction will occur at Aurora with the resulting bitumen transported as a froth by pipeline back to the existing plant for upgrading to Syncrude Sweet Blend. A total of 120 km of pipeline will be used. Syncrude has developed a new method of sending oilsand from its Athabasca deposit to the extraction plant. The company plans to phase out the dragline, bucketwheel reclaimer, and conveyor ore mining and delivery system in favour of shovel, truck, and hydrotransport technology. The advantages of hydrotransport include significant energy savings and considerably less plant infrastructure. A hydrotransport prototype is at work at Syncrude's base mine where it is responsible for 15 per cent of the production

  3. Syncrude`s Aurora Mine : the key to future Athabasca oil sands development

    Energy Technology Data Exchange (ETDEWEB)

    Kershaw, D. [Syncrude Canada Ltd., Edmonton, AB (Canada)

    1998-09-01

    Syncrude`s newest mine, the Aurora mine is located 35 km northeast of Syncrude`s existing Mildred Lake plant, across the Athabasca River. It has a potential to produce more than 2.5 billion barrels of bitumen. Aurora will eventually consist of two surface mines, the Aurora North and Aurora South. Mining and extraction will occur at Aurora with the resulting bitumen transported as a froth by pipeline back to the existing plant for upgrading to Syncrude Sweet Blend. A total of 120 km of pipeline will be used. Syncrude has developed a new method of sending oilsand from its Athabasca deposit to the extraction plant. The company plans to phase out the dragline, bucketwheel reclaimer, and conveyor ore mining and delivery system in favour of shovel, truck, and hydrotransport technology. The advantages of hydrotransport include significant energy savings and considerably less plant infrastructure. A hydrotransport prototype is at work at Syncrude`s base mine where it is responsible for 15 per cent of the production.

  4. Online Planetary Science Courses at Athabasca University

    Science.gov (United States)

    Connors, Martin; Munyikwa, Ken; Bredeson, Christy

    2016-01-01

    Athabasca University offers distance education courses in science, at freshman and higher levels. It has a number of geology and astronomy courses, and recently opened a planetary science course as the first upper division astronomy course after many years of offering freshman astronomy. Astronomy 310, Planetary Science, focuses on process in the Solar System on bodies other than Earth. This process-oriented course uses W. F. Hartmann's "Moons and Planets" as its textbook. It primarily approaches the subject from an astronomy and physics perspective. Geology 415, Earth's Origin and Early Evolution, is based on the same textbook, but explores the evidence for the various processes, events, and materials involved in the formation and evolution of Earth. The course provides an overview of objects in the Solar System, including the Sun, the planets, asteroids, comets, and meteoroids. Earth's place in the solar system is examined and physical laws that govern the motion of objects in the universe are looked at. Various geochemical tools and techniques used by geologists to reveal and interpret the evidence for the formation and evolution of bodies in the solar system as well as the age of earth are also explored. After looking at lines of evidence used to reconstruct the evolution of the solar system, processes involved in the formation of planets and stars are examined. The course concludes with a look at the origin and nature of Earth's internal structure. GEOL415 is a senior undergraduate course and enrols about 15-30 students annually. The courses are delivered online via Moodle and student evaluation is conducted through assignments and invigilated examinations.

  5. Recent innovative applications of geophysics to new uranium discoveries in the Athabasca Basin

    International Nuclear Information System (INIS)

    The history of exploration for uranium in the Athabasca Basin of northern Saskatchewan, Canada, has evolved from early airborne radiometric surveys and ground prospecting in the 1960's to resistivity, gravity and horizontal loop electromagnetic (HLEM) surveys plus drilling in the 1970's, to a predominance of deep penetrating airborne and ground time domain electromagnetic (TDEM) surveys since then, accompanied by systematic drilling of graphitic conductors at regular intervals. While other types of geophysical surveys have been and are still employed to supplement EM techniques, exploration remains very much a conductor-focused exercise. The eastern Athabasca basin has seen most of the historic exploration work and is becoming very much a mature uranium play. There is a limited amount of remaining conductor length to be tested for conventional unconformity-type deposits, and there is evidence of a diminishing return on this methodology. While discoveries of less than 30,000 tonnes (U3O8) have been made, it has been seventeen years since the discovery of the world class McArthur River deposit in 1988. This has led to the realization that a paradigm shift is required to improve the discovery rate and sustain uranium production from the basin. At Cameco, a new defining principle is a greater emphasis on employing geophysical techniques to remotely map the ore system geology at all scales, both the geological conditions that favor uranium deposition/preservation and the subtle manifestations of the presence of a uranium deposit. This means greater attention to attempting to understand the lithostructural setting and the ore-fluid processes involved. Innovative thinking and integration in the last five years have significantly improved Cameco's rate of discovery and identification of new uranium occurrences in the Athabasca Basin of northern Saskatchewan, Canada. Some recent discoveries which will be discussed, in order of advancement, are 1) the O2 North Extension

  6. Bird nesting on an Athabasca power line structure

    International Nuclear Information System (INIS)

    SaskPower has recently completed its 400 km Athabasca power line, and is evaluating the predicted environmental impact of the line on the resident population of bald eagles and other raptors. During construction of the line, five major types of impact associated with the line were addressed. Minor route adjustments were made to by-pass nests of bald eagles and osprey to minimize impact of construction on breeding. The proximity of the power line to cliff faces and the north shore of lake Athabasca was maximized, and frequency of stream crossings and proximity to rapids were minimized. Route adjustments were made to ensure that the line was at least 1.6 km from bald eagle nest sites. As structures of the main 115 kV power line allow a minimum separation between conductors and grounded spars of 1.6 m, and between conductors of 4.6 m, electrocution was not considered to be a significant risk. However, on the 25 kV power line in regions of known bald eagle activity and in close proximity to bodies of water, provision was made for special structures to allow birds to perch without danger of electrocution. It was concluded that the resident population of raptors will probably be enhanced, particularly in areas not previously utilized. 8 refs., 5 figs

  7. Method for Extraction and Multielement Analysis of Hypogymnia Physodes Samples from the Athabasca Oil Sands Region

    Science.gov (United States)

    A microwave-assisted digestion technique followed by ICPMS (inductively coupled plasma-mass spectrometry) analysis was used to measure concentrations of 43 elements in Hypogymnia physodes samples collected in the Athabasca Oil Sands Region (AOSR) of northern Alberta, Canad...

  8. Quantifying saline groundwater seepage to surface waters in the Athabasca oil sands region

    International Nuclear Information System (INIS)

    Western Canadian oil sands contain over 170 billion barrels of proven unconventional petroleum reserves currently extracted at 1.8 million barrels per day by either surface mining, or by in situ techniques that require subsurface injection of steam and hydrocarbon solvents. Natural high-salinity springs are known to add water and entrained inorganic and organic constituents to the Athabasca River and its tributaries in the region of ongoing bitumen production. However, the magnitude and synoptic distribution of these saline inputs has remained unquantified. Here, a chloride mass balance is used to estimate saline groundwater discharge to the Athabasca River from 1987 to 2010. Results show that the highest saline water discharge rate to the Athabasca River occurs between Ft. McMurray and the Peace-Athabasca Delta, supported by subcrop exposure of lower Cretaceous- and Devonian-aged formations bearing saline waters. Further, the input of saline groundwater is found to be an important control on the chemistry of the lower Athabasca River, despite comprising 10−1 to 3% of the Athabasca River’s discharge. The flux of natural saline groundwater entering the Athabasca does not appear to have increased or decreased from 1987 to 2010. The origin of seep salinity is interpreted as relict subglacial meltwater that has dissolved Devonian-aged evaporites, supported by saline Na-Cl type waters with low 18O/16O and 2H/1H ratios relative to modern precipitation. The magnitude of groundwater discharge and its impact on the Athabasca River’s chemistry in the area of ongoing bitumen development warrants the incorporation of natural groundwater seepages into surface water quality monitoring networks.

  9. A bioassessment of lakes in the Athabasca Oil Sands Region, Alberta, using benthic macroinvertebrates

    Directory of Open Access Journals (Sweden)

    Keith M. SOMERS

    2010-08-01

    Full Text Available Emissions of sulphur oxides, nitrogen oxides and other pollutants have increased in the Athabasca Oil Sands Region (AOSR in Alberta, Canada. Atmospheric pollutants impact aquatic communities through a number of processes, but due to a lack of regional monitoring programs potential biological impacts have not been assessed. In this study, a bioassessment was conducted using approaches borrowed from a variety of protocols to establish a baseline dataset, determine appropriate methodologies, and to assess the current impact of emissions on benthic macroinvertebrate (BMI communities in the AOSR. As a result, 32 lakes, including 5 test lakes located in a modelled high deposition region, were sampled for water chemistry and BMI. The Reference Condition Approach (RCA was used because a baseline dataset does not exist and data were evaluated using three separate statistical techniques. All of the statistical methods used: One Sample T-Tests, Multivariate Analysis of Variance (MANOVA and Test Site Analysis (TSA, showed that BMI assemblages in test lakes differed from BMI assemblages in reference lakes. Traditional statistics classified all 5 test lakes as "significantly impaired" whereas TSA identified 3 of the 5 test lakes as only potentially impaired and 2 lakes were in "reference condition". The variability in lake attributes present challenges in interpreting BMI data and establishing an accurate biomonitoring program in the AOSR which need to be addressed in future assessment studies.

  10. Legacy of a half century of Athabasca oil sands development recorded by lake ecosystems.

    Science.gov (United States)

    Kurek, Joshua; Kirk, Jane L; Muir, Derek C G; Wang, Xiaowa; Evans, Marlene S; Smol, John P

    2013-01-29

    The absence of well-executed environmental monitoring in the Athabasca oil sands (Alberta, Canada) has necessitated the use of indirect approaches to determine background conditions of freshwater ecosystems before development of one of the Earth's largest energy deposits. Here, we use highly resolved lake sediment records to provide ecological context to ∼50 y of oil sands development and other environmental changes affecting lake ecosystems in the region. We show that polycyclic aromatic hydrocarbons (PAHs) within lake sediments, particularly C1-C4-alkylated PAHs, increased significantly after development of the bitumen resource began, followed by significant increases in dibenzothiophenes. Total PAH fluxes in the modern sediments of our six study lakes, including one site ∼90 km northwest of the major development area, are now ∼2.5-23 times greater than ∼1960 levels. PAH ratios indicate temporal shifts from primarily wood combustion to petrogenic sources that coincide with greater oil sands development. Canadian interim sediment quality guidelines for PAHs have been exceeded since the mid-1980s at the most impacted site. A paleoecological assessment of Daphnia shows that this sentinel zooplankter has not yet been negatively impacted by decades of high atmospheric PAH deposition. Rather, coincident with increases in PAHs, climate-induced shifts in aquatic primary production related to warmer and drier conditions are the primary environmental drivers producing marked daphniid shifts after ∼1960 to 1970. Because of the striking increase in PAHs, elevated primary production, and zooplankton changes, these oil sands lake ecosystems have entered new ecological states completely distinct from those of previous centuries. PMID:23297215

  11. Changes in the areal extents of the Athabasca River, Birch River, and Cree Creek Deltas, 1950-2014, Peace-Athabasca Delta, Canada

    Science.gov (United States)

    Timoney, Kevin; Lee, Peter

    2016-04-01

    Deltas form where riverborne sediment accumulates at the interface of river mouths and their receiving water bodies. Their areal extent is determined by the net effect of processes that increase their extent, such as sediment accumulation, and processes that decrease their extent, such as erosion and subsidence. Through sequential mapping and construction of river discharge and sediment histories, this study examined changes in the subaerial extents of the Cree Creek and Athabasca River Deltas (both on the Athabasca River system) and the Birch River Delta in northern Canada over the period 1950-2014. The purpose of the study was to determine how, when, and why the deltas changed in areal extent. Temporal growth patterns were similar across the Athabasca and Birch River systems indicative of a climatic signal. Little or no areal growth occurred from 1950 to 1968; moderate growth occurred between 1968 and the early to mid-1980s; and rapid growth occurred between 1992 and 2012. Factors that affected delta progradation included dredging, sediment supply, isostatic drowning, delta front bathymetry, sediment capture efficiency, and storms. In relation to sediment delivered, areal growth rates were lowest in the Athabasca Delta, intermediate in the Birch Delta, and highest in the Cree Creek Delta. Annual sediment delivery is increasing in the Cree Creek Delta; there were no significant trends in annual sediment delivery in the Birch and Athabasca Deltas. There was a lag of up to several years between sediment delivery events and progradation. Periods of delta progradation were associated with low water levels of the receiving basins. Predicted climate-change driven declines in river discharge and lake levels may accelerate delta progradation in the region. In the changing ecosystems of northeastern Alberta, inadequate monitoring of vegetation, landforms, and sediment regimes hampers the elucidation of the nature, rate, and causality of ecosystem changes.

  12. Palaeolimnological assessment of lake acidification and environmental change in the Athabasca Oil Sands Region, Alberta

    Directory of Open Access Journals (Sweden)

    Sergi PLA

    2010-08-01

    Full Text Available Exploitation of the Athabasca Oil Sands has expanded hugely over the last 40 years. Regional emissions of oxidised sulphur and nitrogen compounds increased rapidly over this period and similar emissions have been linked to lake acidification in other parts of North America and Europe. To determine whether lakes in the region have undergone acidification, 12 lakes within the Regional Municipality of Wood Buffalo and the Caribou Mountains were selected to cover chemical and spatial gradients and sediment cores were obtained for palaeolimnological analyses including radiometric dating, diatom analysis, isotopic analysis of bulk sediment 13C and 15N, and spheroidal carbonaceous particles (SCPs. All lake sediment cores show evidence of industrial contamination based on SCPs, but there is no clear industrial signal in stable isotopes. Most lakes showed changes in diatom assemblages and sediment C:N ratios consistent with nutrient enrichment over various timescales, with potential drivers including climatic change, forest fires and anthropogenic nitrogen deposition. Only one of the 12 lakes investigated showed strong evidence of acidification with a decline in diatom-inferred pH from 6.3 to 5.6 since 1970 linked to increasing relative abundances of the acidophilous diatom species Actinella punctata, Asterionella ralfsii and Fragilariforma polygonata. Analysis of mercury (Hg in the acidified lake showed increasing sediment fluxes over the last 20 years, a possible indication of industrial contamination. The acidified lake is the smallest of those studied with the shortest residence time, suggesting a limited capacity for neutralisation of acid inputs in catchment soils or by inlake processes.

  13. Choosing MOODLE: An Evaluation of Learning Management Systems at Athabasca University

    Science.gov (United States)

    Stewart, Brian; Briton, Derek; Gismondi, Mike; Heller, Bob; Kennepohl, Dietmar; McGreal, Rory; Nelson, Christine

    2007-01-01

    Athabasca University--Canada's Open University evaluated learning management systems (LMS) for use by the university. Evaluative criteria were developed in order to ensure that different platforms were tested against weighted criteria representing the needs of the university. Three LMSs (WebCt, LotusNotes, and Moodle) were selected for the…

  14. "The Open Library at AU" (Athabasca University): Supporting Open Access and Open Educational Resources

    Science.gov (United States)

    Elliott, Colin; Fabbro, Elaine

    2015-01-01

    To address challenges that learners, course creators, librarians and academics involved with OER and MOOCs are facing when looking for scholarly materials, Athabasca University Library has initiated the development of "the Open Library at AU." This open library is a full library website that provides easy access to open and free…

  15. Investing for the future : Athabasca Oil Sands Trust 1998 annual report

    International Nuclear Information System (INIS)

    The Athabasca Oil Sand Trust was created in 1995 when a subsidiary of the Trust, Athabasca Oil Sands Investment Inc., acquired Alberta's 11.74 per cent working interest in the Syncrude Project, which is a joint venture involved in the mining and upgrading of bitumen from the Athabasca oil sands. The Trust is a closed-end investment trust which was created to provide an opportunity for direct public investment in Syncrude and oil sands development in northern Alberta. Syncrude, produced a record 76.7 million barrels of Syncrude Sweet Blend (SSB), and shipped its one billionth barrel on April 16, 1998. Another key achievement in 1998 was the investment the Syncrude Joint Venture Partners of almost half a billion dollars to maintain Syncrude's operations and pursue the Business Plan growth targets outlined in last year's report. By aggressively pursuing this capital investment program despite the current low oil prices, the Syncrude Joint Venture Partners expect to double SSB production to 155 million barrels per year by 2007. The Athabasca Trust's share of these capital expenditures to fuel the projected growth in production is about $ 70 million this year and the next. The report provides operating statistics on production, financial highlights and consolidated balance sheets for 1998, including operating expenditures, capital expenditures, and the usual notes to the consolidated financial statement. 10 tabs., 2 figs

  16. As long as the rivers flow: Athabasca River knowledge, use and change

    Energy Technology Data Exchange (ETDEWEB)

    Candler, C.; Olson, R.; Deroy, S. [Firelight Group Research Cooperative, Victoria, BC (Canada)

    2010-11-15

    This document is a report supported by specific information gathered by the Athabasca Chipewyan First Nation (ACFN) and the Mikisew Cree First Nation (MCFN), and takes part in an Athabasca River Use and Traditional Ecological Knowledge (TEK) study conducted in 2010. The main objective was to provide a written submission, based on evidence, in order to effectively notify the crown about plans for managing industrial water withdrawals from the lower Athabasca River. The First Nations used the same methods, wrote their community reports as distinguished stand-alone documents and made the choice to present the ACFN and MCFN data in parallel with each other within the same document. The study provides information on the knowledge and uses of the Athabasca River by the community members. Context and background for the study can be found in the part A. It comprises a short discussion of the Treaty No.8 of 1899, the latter confirming the rights of First Nation people. The importance of boat transportation for the community members is mentioned, and a summary of the methods is given. The results of the ACFN and MCFN studies are given in part B and C. The reduction of the quantity and quality of the river has affected the practice of ACFN and MCFN aboriginal and treaty rights. The community perceptions of the changes of the river and how it has influenced their lifestyle is discussed. Some uses of the Athabasca river have been lost because of concerns regarding contamination associated with oil sands operations. The last part of the document provides an analysis of results and suggests two thresholds that define the ability of ACFN and MCFN members to practice their rights and access their territories. This document ends with recommendations for implementation of these thresholds. 22 refs., 12 maps.

  17. Alberta's economic development of the Athabasca oil sands

    Science.gov (United States)

    Steinmann, Michael

    This dissertation examines the 61-year evolution of public policies pertaining to development of Alberta's non-conventional source of crude oil. The Athabasca oil sands contain an estimated 1.5 trillion barrels and provide for a safe continental supply. The Provincial Government first sponsored this undertaking in 1943. The period from then to 1971 was one of a transition from a wheat economy to a natural-resource economic base. A stable government emerged and was able to negotiate viable development policies. A second period, 1971 to 1986, was marked by unstable world conditions that afforded the Alberta government the ability to set terms of development with multi-national oil firms. A 50% profit-sharing plan was implemented, and basic 1973 terms lasted until 1996. However, 1986 was a critical year because the Organization of Petroleum Exporting Countries (OPEC) reduced prices, causing the Alberta economy to lapse into recession. During a third period, 1986 to 1996, the Alberta Government was unable to adapt quickly to world conditions. A new leadership structure in 1996 made major changes to create ongoing fiscal and development policies. That history provides answers to two primary research questions: How do public policies affect the behaviors of the modern corporation and visa versa? What are the implications for development theory? Two sources of information were used for this study. First, it was possible to review the Premier's files located in the Provincial Archives. Materials from various government libraries were also examined. Some 7,000 documents were used to show the evolution of government policymaking. Second, interviews with leaders of oil companies and federal research facilities were important. Findings support the thesis that, to facilitate oil sands development, government and the private sector have closely collaborated. In particular, revenue policies have allowed for effective R&D organization. Relying on intensive technological

  18. Airborne Petcoke Dust is a Major Source of Polycyclic Aromatic Hydrocarbons in the Athabasca Oil Sands Region.

    Science.gov (United States)

    Zhang, Yifeng; Shotyk, William; Zaccone, Claudio; Noernberg, Tommy; Pelletier, Rick; Bicalho, Beatriz; Froese, Duane G; Davies, Lauren; Martin, Jonathan W

    2016-02-16

    Oil sands mining has been linked to increasing atmospheric deposition of polycyclic aromatic hydrocarbons (PAHs) in the Athabasca oil sands region (AOSR), but known sources cannot explain the quantity of PAHs in environmental samples. PAHs were measured in living Sphagnum moss (24 sites, n = 68), in sectioned peat cores (4 sites, n = 161), and snow (7 sites, n = 19) from ombrotrophic bogs in the AOSR. Prospective source samples were also analyzed, including petroleum coke (petcoke, from both delayed and fluid coking), fine tailings, oil sands ore, and naturally exposed bitumen. Average PAH concentrations in near-field moss (199 ng/g, n = 11) were significantly higher (p = 0.035) than in far-field moss (118 ng/g, n = 13), and increasing temporal trends were detected in three peat cores collected closest to industrial activity. A chemical mass-balance model estimated that delayed petcoke was the major source of PAHs to living moss, and among three peat core the contribution to PAHs from delayed petcoke increased over time, accounting for 45-95% of PAHs in contemporary layers. Petcoke was also estimated to be a major source of vanadium, nickel, and molybdenum. Scanning electron microscopy with energy-dispersive X-ray spectroscopy confirmed large petcoke particles (>10 μm) in snow at near-field sites. Petcoke dust has not previously been considered in environmental impact assessments of oil sands upgrading, and improved dust control from growing stockpiles may mitigate future risks.

  19. Airborne Petcoke Dust is a Major Source of Polycyclic Aromatic Hydrocarbons in the Athabasca Oil Sands Region.

    Science.gov (United States)

    Zhang, Yifeng; Shotyk, William; Zaccone, Claudio; Noernberg, Tommy; Pelletier, Rick; Bicalho, Beatriz; Froese, Duane G; Davies, Lauren; Martin, Jonathan W

    2016-02-16

    Oil sands mining has been linked to increasing atmospheric deposition of polycyclic aromatic hydrocarbons (PAHs) in the Athabasca oil sands region (AOSR), but known sources cannot explain the quantity of PAHs in environmental samples. PAHs were measured in living Sphagnum moss (24 sites, n = 68), in sectioned peat cores (4 sites, n = 161), and snow (7 sites, n = 19) from ombrotrophic bogs in the AOSR. Prospective source samples were also analyzed, including petroleum coke (petcoke, from both delayed and fluid coking), fine tailings, oil sands ore, and naturally exposed bitumen. Average PAH concentrations in near-field moss (199 ng/g, n = 11) were significantly higher (p = 0.035) than in far-field moss (118 ng/g, n = 13), and increasing temporal trends were detected in three peat cores collected closest to industrial activity. A chemical mass-balance model estimated that delayed petcoke was the major source of PAHs to living moss, and among three peat core the contribution to PAHs from delayed petcoke increased over time, accounting for 45-95% of PAHs in contemporary layers. Petcoke was also estimated to be a major source of vanadium, nickel, and molybdenum. Scanning electron microscopy with energy-dispersive X-ray spectroscopy confirmed large petcoke particles (>10 μm) in snow at near-field sites. Petcoke dust has not previously been considered in environmental impact assessments of oil sands upgrading, and improved dust control from growing stockpiles may mitigate future risks. PMID:26771587

  20. Long-term reliability of the Athabasca River (Alberta, Canada) as the water source for oil sands mining

    Science.gov (United States)

    St-Jacques, J. M.; Sauchyn, D.; Luckman, B. H.

    2015-12-01

    Exploitation of the Alberta oil sands, the world's third largest crude oil reserve, requires fresh water from the Athabasca River, an allocation of 4.4% of the mean annual flow. This allocation takes into account seasonal fluctuations but not long-term climatic variability and change. This paper examines the decadal-scale variability in river discharge in the Athabasca River Basin (ARB) with 1) a generalized-least-squares (GLS) regression analysis of the trend and variability in gauged flow, and 2) a 900-year tree-ring reconstruction of the water-year flow of the Athabasca River at Athabasca, Alberta. The GLS analysis removes confounding transient trends related to the Pacific Decadal Oscillation (PDO) and Pacific North American mode (PNA). It shows long-term declining flows throughout the ARB. The tree-ring record reveals a larger range of flows and severity of hydrologic deficits than those captured by the instrumental records that are the basis for surface water allocation. It includes periods of sustained low flow of multiple decades in duration, suggesting the influence of the PDO and PNA teleconnections. These results together demonstrate that low-frequency variability must be considered in ARB water allocation, which has not been the case. We show that the current and projected surface water allocations from the Athabasca River for the exploitation of the Alberta oil sands are based on an untenable assumption of the representativeness of the short instrumental record.

  1. Spatial and temporal distribution of ambient nitric acid and ammonia in the Athabasca Oil Sands Region, Alberta

    Directory of Open Access Journals (Sweden)

    Diane ALEXANDER

    2010-08-01

    Full Text Available Monthly average ambient concentrations of gaseous nitric acid (HNO3 and ammonia (NH3 were monitored at the Athabasca Oils Sands Region (AOSR, Alberta, Canada, between May 2005 and September 2008. Generally, concentrations of both pollutants were elevated and highly variable in space and time. The highest atmospheric concentrations occurred in the vicinity of the major mining and oil extraction activities of Fort Murray and Fort McKay. Maximum monthly average concentrations of HNO3 decreased from >6 μg m–3 2005 and 2006 to <4 μg m–3 in 2007 and 2008. While the HNO3 summer seasonal averages in 2005 and 2006 approached ~2 μg m–3 at some sites, in the subsequent summers and during winter seasons it rarely exceeded 1 μg m–3 and no clear differences between summer and winter occurred. Concentrations of NH3 were elevated during the entire study and frequently reached 6 μg m–3. Generally, NH3 stayed higher in summer than in winter; the summer seasonal averages often exceeded 4 μg m–3 while those for winter only on two occasions were above 3 μg m–3. In summer 2008, an expansion of the area with elevated NH3 levels was observed extending to remote locations. Ammonia is of a much higher concern from a perspective of possible biological effects, because of its potential for direct toxic effect on lichens and its contribution to the elevated N dry deposition with possible negative consequences for forests and other ecosystems.

  2. Multicomponent seismic reservoir characterization of a steam-assisted gravity drainage (SAGD) heavy oil project, Athabasca oil sands, Alberta

    Science.gov (United States)

    Schiltz, Kelsey Kristine

    Steam-assisted gravity drainage (SAGD) is an in situ heavy oil recovery method involving the injection of steam in horizontal wells. Time-lapse seismic analysis over a SAGD project in the Athabasca oil sands deposit of Alberta reveals that the SAGD steam chamber has not developed uniformly. Core data confirm the presence of low permeability shale bodies within the reservoir. These shales can act as barriers and baffles to steam and limit production by prohibiting steam from accessing the full extent of the reservoir. Seismic data can be used to identify these shale breaks prior to siting new SAGD well pairs in order to optimize field development. To identify shale breaks in the study area, three types of seismic inversion and a probabilistic neural network prediction were performed. The predictive value of each result was evaluated by comparing the position of interpreted shales with the boundaries of the steam chamber determined through time-lapse analysis. The P-impedance result from post-stack inversion did not contain enough detail to be able to predict the vertical boundaries of the steam chamber but did show some predictive value in a spatial sense. P-impedance from pre-stack inversion exhibited some meaningful correlations with the steam chamber but was misleading in many crucial areas, particularly the lower reservoir. Density estimated through the application of a probabilistic neural network (PNN) trained using both PP and PS attributes identified shales most accurately. The interpreted shales from this result exhibit a strong relationship with the boundaries of the steam chamber, leading to the conclusion that the PNN method can be used to make predictions about steam chamber growth. In this study, reservoir characterization incorporating multicomponent seismic data demonstrated a high predictive value and could be useful in evaluating future well placement.

  3. Natural radiation-induced damage in quartz. III. A new ozonide radical in drusy quartz from the Athabasca Basin, Saskatchewan

    International Nuclear Information System (INIS)

    Quartz crystals collected in druses, including one annealed at 400oC, from a fracture in the hanging-wall sandstone at the McArthur River uranium deposit in the Paleoproterozoic Athabasca basin, northern Saskatchewan, have been investigated by single-crystal X-band electron paramagnetic resonance (EPR) spectroscopy at room temperature and 110 K. The single-crystal EPR spectra allow us to distinguish eight paramagnetic defects, including one new center and seven previously reported centers. These centers, most of which were discovered in artificially irradiated crystals and only a few had been suggested to occur in natural quartz by powder EPR, are herewith positively established for the first time as natural radiation-induced defects by single-crystal EPR. The new center is similar in principal g-factor values to the ozonide radical (O3-) in various minerals and synthetic compounds, and is characterized by its g-maximum and g-minimum axes approximately parallel to two O-O edges of the SiO4 quasi-tetrahedron in the quartz structure. This geometry is also compatible with an ozonide radical formed from a silicon vacancy. The observed linewidths of the new ozonide radical vary from 0.087 to 0.257 mT, which are attributed to unresolved site-splittings or unresolved hyperfine splittings. This new ozonide radical is distinct from a previously reported ozonide radical in citrine quartz, which is characterized by the presence of a small 27Al hyperfine structure. The new ozonide radical is probably linked to a Si atom in the neighboring tetrahedron and hence represents a general case in quartz, whereas the previously reported ozonide radical linked to a neighboring Al atom is a special variant in Al-bearing quartz. The presence of natural radiation-induced defects in drusy quartz is attributable to the presence of uranium in mineralized assemblages nearby or late hydrothermal fluids. (author)

  4. Natural radiation-induced damage in quartz. III. A new ozonide radical in drusy quartz from the Athabasca Basin, Saskatchewan

    Energy Technology Data Exchange (ETDEWEB)

    Botis, S.M.; Pan, Y.; Nokhrin, S. [Univ. of Saskatchwan, Dept. of Geological Sciences, Saskatoon, Saskatchewan (Canada); Nilges, M.J. [Univ. of Illinois at Urbana-Champaign, Illinois EPR Research Center, Urbana, Illinois (United States)

    2008-02-15

    Quartz crystals collected in druses, including one annealed at 400{sup o}C, from a fracture in the hanging-wall sandstone at the McArthur River uranium deposit in the Paleoproterozoic Athabasca basin, northern Saskatchewan, have been investigated by single-crystal X-band electron paramagnetic resonance (EPR) spectroscopy at room temperature and 110 K. The single-crystal EPR spectra allow us to distinguish eight paramagnetic defects, including one new center and seven previously reported centers. These centers, most of which were discovered in artificially irradiated crystals and only a few had been suggested to occur in natural quartz by powder EPR, are herewith positively established for the first time as natural radiation-induced defects by single-crystal EPR. The new center is similar in principal g-factor values to the ozonide radical (O{sub 3}{sup -}) in various minerals and synthetic compounds, and is characterized by its g-maximum and g-minimum axes approximately parallel to two O-O edges of the SiO{sub 4} quasi-tetrahedron in the quartz structure. This geometry is also compatible with an ozonide radical formed from a silicon vacancy. The observed linewidths of the new ozonide radical vary from 0.087 to 0.257 mT, which are attributed to unresolved site-splittings or unresolved hyperfine splittings. This new ozonide radical is distinct from a previously reported ozonide radical in citrine quartz, which is characterized by the presence of a small {sup 27}Al hyperfine structure. The new ozonide radical is probably linked to a Si atom in the neighboring tetrahedron and hence represents a general case in quartz, whereas the previously reported ozonide radical linked to a neighboring Al atom is a special variant in Al-bearing quartz. The presence of natural radiation-induced defects in drusy quartz is attributable to the presence of uranium in mineralized assemblages nearby or late hydrothermal fluids. (author)

  5. Running out of steam? Oil sands development and water use in the Athabasca River watershed : science and market based solutions

    International Nuclear Information System (INIS)

    This paper contained 2 reports conducted to assess the implications of current and planned water withdrawals from the Athabasca River, and options for water management. This first section examined future water flows and human withdrawals from the Athabasca River, and examined forecasted changes in climate in the oil sands region. Issues related to water flow, water quality, and instream flow needs were discussed. The second section examined options available to the industry. Alberta's current water use framework was discussed, and new policy targets and mechanisms were analyzed. 72 refs., 21 figs

  6. Properties Correlations and Characterization of Athabasca Oil Sands-derived Synthetic Crude Oil

    Institute of Scientific and Technical Information of China (English)

    Wang Jun; Zhao Suoqi; Xu Chunming; Chung Keng H.

    2007-01-01

    Narrow fractions of Athabasca oil sands-derived synthetic crude oil (SCO) from Canada were obtained by distillation at 20 ℃ to 500 ℃ and characterized. The yield and properties, such as density, refractive index, viscosity,freezing point, sulfur and nitrogen content and UOP K-index, were correlated as a function of boiling temperature (Tb).The properties of naphtha fractions, jet fuel and diesel fractions could be predicted accurately with the correlations, which are useful for process design considerations, such as optimizing operating conditions of refinery processing units. The other key properties and characteristics of naphtha fractions, jet fuel, diesel and vacuum gas oil were also determined.

  7. Impacts of sulphur and nitrogen deposition in western Canada

    OpenAIRE

    Patrick D. SHAW; Julian AHERNE

    2010-01-01

    The expansion of transportation sectors (road vehicles and marine vessels), industry (e.g., oil and gas) and urban centres in western Canada has triggered a growth in research, monitoring and modelling activities investigating the impacts of sulphur and nitrogen deposition on aquatic and terrestrial ecosystems. This special issue presents an overview of related research in British Columbia (Georgia Basin), Alberta (Athabasca Oil Sands Region), Saskatchewan and Manitoba. The research provides ...

  8. Microbial processes in the Athabasca Oil Sands and their potential applications in microbial enhanced oil recovery.

    Science.gov (United States)

    Harner, N K; Richardson, T L; Thompson, K A; Best, R J; Best, A S; Trevors, J T

    2011-11-01

    The Athabasca Oil Sands are located within the Western Canadian Sedimentary Basin, which covers over 140,200 km(2) of land in Alberta, Canada. The oil sands provide a unique environment for bacteria as a result of the stressors of low water availability and high hydrocarbon concentrations. Understanding the mechanisms bacteria use to tolerate these stresses may aid in our understanding of how hydrocarbon degradation has occurred over geological time, and how these processes and related tolerance mechanisms may be used in biotechnology applications such as microbial enhanced oil recovery (MEOR). The majority of research has focused on microbiology processes in oil reservoirs and oilfields; as such there is a paucity of information specific to oil sands. By studying microbial processes in oil sands there is the potential to use microbes in MEOR applications. This article reviews the microbiology of the Athabasca Oil Sands and the mechanisms bacteria use to tolerate low water and high hydrocarbon availability in oil reservoirs and oilfields, and potential applications in MEOR. PMID:21853326

  9. Toxicity of Athabasca River and oil sands sediments to larval fish

    Energy Technology Data Exchange (ETDEWEB)

    Parrott, J.; Turcotte, D.; Headley, J.; Hewitt, M. [Environment Canada, Ottawa, ON (Canada)

    2010-07-01

    This presentation reported on a study that evaluated oil sands tailings pond sediments and sediments from the Athabasca River for embryo-larval toxicity in fathead minnows and walleye. Following 20 days of exposure to 5 sediments from the Athabasca River at concentrations up to 25 g/L, there were no observed effects in fathead minnow eggs and larvae. However, at concentrations as low as 0.2 to 1 g wet wt/L, two of three tailings pond sediments were toxic to fathead minnows. Larvae growth was reduced in all three tailings pond sediments. Nine of 18 polycyclic aromatic hydrocarbons (PAHs) measured in tailing pond sediments were found to be above the Freshwater Sediment Quality Guidelines set by the Canadian Council of Ministers of the Environment (CCME), with phenanthrene being the highest. The values for total dry weight PAHs and total naphthenic acids in tailings pond sediment and river sediment were discussed. The cause for the observed toxicity in fathead minnow larvae could not be determined based on the preliminary study results. As part of the ongoing study, walleye eggs and larvae are being exposed to the sediments to compare their relative sensitivity and to determine possible causative compounds.

  10. Toxicity of Athabasca River and oil sands sediments to larval fish

    International Nuclear Information System (INIS)

    This presentation reported on a study that evaluated oil sands tailings pond sediments and sediments from the Athabasca River for embryo-larval toxicity in fathead minnows and walleye. Following 20 days of exposure to 5 sediments from the Athabasca River at concentrations up to 25 g/L, there were no observed effects in fathead minnow eggs and larvae. However, at concentrations as low as 0.2 to 1 g wet wt/L, two of three tailings pond sediments were toxic to fathead minnows. Larvae growth was reduced in all three tailings pond sediments. Nine of 18 polycyclic aromatic hydrocarbons (PAHs) measured in tailing pond sediments were found to be above the Freshwater Sediment Quality Guidelines set by the Canadian Council of Ministers of the Environment (CCME), with phenanthrene being the highest. The values for total dry weight PAHs and total naphthenic acids in tailings pond sediment and river sediment were discussed. The cause for the observed toxicity in fathead minnow larvae could not be determined based on the preliminary study results. As part of the ongoing study, walleye eggs and larvae are being exposed to the sediments to compare their relative sensitivity and to determine possible causative compounds.

  11. Characterization of Physically and Chemically Separated Athabasca Asphaltenes Using Small-Angle X-ray Scattering

    Energy Technology Data Exchange (ETDEWEB)

    Amundaraín Hurtado, Jesús Leonardo; Chodakowski, Martin; Long, Bingwen; Shaw, John M. (Alberta)

    2012-02-07

    Athabasca asphaltenes were characterized using small-angle X-ray scattering (SAXS). Two methods were used to separate asphaltenes from the Athabasca bitumen: namely, chemical separation by precipitation with n-pentane and physical separation by nanofiltration using a zirconia membrane with a 20 nm average pore size. The permeate and chemically separated samples were diluted in 1-methylnaphtalene and n-dodecane prior to SAXS measurements. The temperature and asphaltene concentration ranges were 50-310 C and 1-10.4 wt %, respectively. Model-independent analysis of SAXS data provided the radius of gyration and the scattering coefficients. Model-dependent fits provided size distributions for asphaltenes assuming that they are dense and spherical. Model-independent analysis for physically and chemically separated asphaltenes showed significant differences in nominal size and structure, and the temperature dependence of structural properties. The results challenge the merits of using chemically separated asphaltene properties as a basis for asphaltene property prediction in hydrocarbon resources. While the residuals for model-dependent fits are small, the results are inconsistent with the structural parameters obtained from model-independent analysis.

  12. Initial environmental impacts of the Obed Mountain coal mine process water spill into the Athabasca River (Alberta, Canada).

    Science.gov (United States)

    Cooke, Colin A; Schwindt, Colin; Davies, Martin; Donahue, William F; Azim, Ekram

    2016-07-01

    On October 31, 2013, a catastrophic release of approximately 670,000m(3) of coal process water occurred as the result of the failure of the wall of a post-processing settling pond at the Obed Mountain Mine near Hinton, Alberta. A highly turbid plume entered the Athabasca River approximately 20km from the mine, markedly altering the chemical composition of the Athabasca River as it flowed downstream. The released plume traveled approximately 1100km downstream to the Peace-Athabasca Delta in approximately four weeks, and was tracked both visually and using real-time measures of river water turbidity within the Athabasca River. The plume initially contained high concentrations of nutrients (nitrogen and phosphorus), metals, and polycyclic aromatic hydrocarbons (PAHs); some Canadian Council of Ministers of the Environmental (CCME) Guidelines were exceeded in the initial days after the spill. Subsequent characterization of the source material revealed elevated concentrations of both metals (arsenic, lead, mercury, selenium, and zinc) and PAHs (acenaphthene, fluorene, naphthalene, phenanthrene, and pyrene). While toxicity testing using the released material indicated a relatively low or short-lived acute risk to the aquatic environment, some of the water quality and sediment quality variables are known carcinogens and have the potential to exert negative long-term impacts. PMID:27017080

  13. Initial insights from 2.5D hydraulic modeling of floods in Athabasca Valles, Mars

    Science.gov (United States)

    Keszthelyi, L.P.; Denlinger, R.P.; O'Connell, D. R. H.; Burr, D.M.

    2007-01-01

    We present the first application of a 2.5D hydraulic model to catastrophic floods on Mars. This model simulates flow over complex topography and incorporates flood dynamics that could not be modeled in the earlier 1D models. We apply this model to Athabasca Valles, the youngest outflow channel on Mars, investigating previous bank-full discharge estimates and utilizing the interpolated Mars Orbiter Laser Altimeter elevation map as input. We confirm that the bank-full assumption does not fit the observed landforms. Instead, the channel appears more deeply incised near the source. Flow modeling also identifies several areas of special interest, including a dry cataract that coincides with a region of predicted high erosion. However, artifacts in the elevation data strongly impacted estimated stages and velocities in other areas. More extensive connection between the flood hydraulics and observed landforms awaits improved topographic data.

  14. Delayed coking studies on Athabasca bitumen and Cold Lake heavy oil

    Energy Technology Data Exchange (ETDEWEB)

    Govindhakannan, J.; Khulbe, C. [National Centre for Upgrading Technology, Devon, AB (Canada); Natural Resources Canada, Devon, AB (Canada). CanmetENERGY

    2009-07-01

    This poster highlighted the results of a study that quantified the delayed coking product yields of Athabasca bitumen and Cold Lake heavy oil. It also investigated the effect of operating pressure and feed rates on product yield and quality. The effect of pressure on conversion of sulphur and nitrogen was also examined. Experimental results revealed that the yield of liquid products decreases and the yields of coke and gases increase as the operating pressure increases. Sulphur and nitrogen conversions increase with increasing pressure. In this study, the yield and quality of delayed coking products were not influenced by the variation in feed rates. It was concluded that feed rate changes do not significantly affect the yield and quality of delayed coking products because the residual liquid and coke trapped in the coker drum reside there for a duration that approaches infinity, compared to much smaller average residence time for vapor-phase compounds. tabs., figs.

  15. The Open Library at AU (Athabasca University: Supporting Open Access and Open Educational Resources

    Directory of Open Access Journals (Sweden)

    Colin Elliott

    2015-04-01

    Full Text Available To address challenges that learners, course creators, librarians and academics involved with OER and MOOCs are facing when looking for scholarly materials, Athabasca University Library has initiated the development of the Open Library at AU. This open library is a full library website that provides easy access to open and free resources. Tools and information literacy tutorials are also included to enable learners, researchers, and others to find, evaluate, and use the information they need for their open learning course or research. Many of the challenges that those involved in open learning face are addressed by the open library and the potential impact it can have on open learning and knowledge sharing is tremendous. http://dx.doi.org/10.5944/openpraxis.7.2.196

  16. Athabasca University: Conversion from Traditional Distance Education to Online Courses, Programs and Services

    Directory of Open Access Journals (Sweden)

    Alan Davis

    2001-01-01

    Full Text Available In its 30 years of operation, Athabasca University has witnessed the full impact of the growth of online distance education. Its conversion from mixed media course production and telephone/ mail tutoring to a variety of electronic information and communication technologies has been heterogeneous across disciplines and programs. Undergraduate programs in business, computing, and some social science programs have largely led the conversion, and all graduate programs have, since their inception, employed various features of online delivery. The parallel conversion of student services has been equally important to the effectiveness of these processes. The implications of this approach for the quality of offerings, support systems, costing, and the primary mandate of the University (which is to remove barriers, not create them are discussed.

  17. Carbon dynamics, food web structure and reclamation strategies in Athabasca oil sands wetlands (CRFAW)

    International Nuclear Information System (INIS)

    This abstract provided details of the Carbon Dynamics, Food Web Structure and Reclamation Strategies in Athabasca Oil Sands Wetlands (CFRAW) program, a collaboration between oil sands industry partners and university laboratories. CFRAW researchers are investigating the effects of mine tailings and process waters on the development, health, and function of wetland communities in post-mining landscapes. The aim of the program is to accurately predict how quickly the reclaimed wetlands will approach conditions seen in reference wetland systems. The program is also examining the effects of hydrocarbons as a surrogate source of carbon after they are metabolized by bacteria. The biological uptake, pathways, and movement through the food web of materials used by the biota in constructed wetlands are also being studied. Flux estimates will be used to determine if wetlands amended with peat will maintain their productivity. A conceptual model of carbon pathways and budgets is also being developed.

  18. Century-long source apportionment of PAHs in Athabasca oil sands region lakes using diagnostic ratios and compound-specific carbon isotope signatures.

    Science.gov (United States)

    Jautzy, Josué; Ahad, Jason M E; Gobeil, Charles; Savard, Martine M

    2013-06-18

    Evaluating the impact that airborne contamination associated with Athabasca oil sands (AOS) mining operations has on the surrounding boreal forest ecosystem requires a rigorous approach to source discrimination. This study presents a century-long historical record of source apportionment of polycyclic aromatic hydrocarbons (PAHs) in dated sediments from two headwater lakes located approximately 40 and 55 km east from the main area of open pit mining activities. Concentrations of the 16 Environmental Protection Agency (EPA) priority PAHs in addition to retene, dibenzothiophene (DBT), and six alkylated groups were measured, and both PAH molecular diagnostic ratios and carbon isotopic signatures (δ(13)C) of individual PAHs were used to differentiate natural from anthropogenic inputs. Although concentrations of PAHs in these lakes were low and below the Canadian Council of Ministers of the Environment (CCME) guidelines, diagnostic ratios pointed to an increasingly larger input of petroleum-derived (i.e., petrogenic) PAHs over the past 30 years concomitant with δ(13)C values progressively shifting to the value of unprocessed AOS bitumen. This petrogenic source is attributed to the deposition of bitumen in dust particles associated with wind erosion from open pit mines.

  19. Coke yield and heat transfer in reaction of liquid-solid agglomerates of Athabasca vacuum residue

    Energy Technology Data Exchange (ETDEWEB)

    Ali, M.; Courtney, M.; Boddez, L.; Gray, M. [Alberta Univ., Edmonton, AB (Canada). Dept. of Chemical and Materials Engineering

    2010-02-15

    Delayed coking and fluid-bed coking are the most common commercial processes used by the petroleum industry for the thermal conversion of vacuum residues into petroleum distillate products. This paper presented the results of an experimental study of coke yield at long reaction times from agglomerates of coke particles and Athabasca vacuum residue (AVR). The ultimate coke yield was determined for a range of agglomerate thicknesses, liquid concentrations and reaction temperatures. The agglomerates were heated on Curie-point alloy strips in an induction furnace at 503 and 530 degrees C until all toluene-soluble material was converted. A simple heat transfer model was used to describe the temperature profile within the agglomerates. Coke yield results from agglomerates were compared to the coke yield results from reacting thin films of vacuum residue. The average coke yield from the agglomerates was 23 per cent, while the coke yield from thin films of 20 {mu}m thickness was 11 per cent, which supports the role of mass transfer in coke formation reactions. The ultimate coke yield was insensitive to vacuum residue concentration, agglomerate size, and reaction temperature. According to control experiments on thin films of liquid at different heating rates, the temperature-time history has little effect on the ultimata coke yield. 13 refs., 2 tabs., 10 figs.

  20. Condensation induced water hammer and steam assisted gravity drainage in the Athabasca oil sands

    International Nuclear Information System (INIS)

    Most people will have been exposed to some aspect of the debate about the Athabasca Oil Sands in North-Eastern Alberta and the significant role that the oil sands are expected to play in supplying conventional fossil fuels. Part of the bitumen is recovered from mines and part is recovered from in situ projects utilizing the Steam Assisted Gravity Drainage Process (SAGD). SAGD utilizes a considerable amount of steam, that is injected into geological formations. Hot water, bitumen and some vapour are recovered from the production wells. With significant steam generation, transmission and injection, there is the very real possibility of condensation induced water hammers. There have been a number of catastrophic failures to date. The intent of the paper is to provide interesting background information on the in situ oil sands industry. More importantly, to show some interesting and broader applications of thermalhydraulics developed in the nuclear industry. The expertise developed may have potential markets, with some adaptation, to the oil sands industry. Finally, there has been some discussion about using nuclear power for steam generation in the oil sands. (orig.)

  1. Modeling and mapping the effects of heat and pressure outside a SAGD steam chamber using time-lapse multicomponent seismic data, Athabasca oil sands, Alberta

    Science.gov (United States)

    Zeigler, Loren Michelle

    The field of study is a bitumen producing reservoir within the McMurray Formation. The deposit is a part of the Athabasca oil sands trend in Northeastern Alberta, Canada. This field contains 16 well pads that are, combined, producing more than 41,000 BOPD. Bitumen reservoirs are unique as a result of their high viscosity, low API gravity oil. This oil in this field has been produced by means of a method called Steam Assisted Gravity Drainage (SAGD), since 2007. In this method, two vertically stacked, horizontal wells are drilled. The upper well injects high temperature, high pressure steam and as the viscosity of the bitumen decreases it will begin to flow, via gravity, down to the lower producing well. Reservoir monitoring in this field is very important for multiple reasons, including the shallow depth and the large velocity changes that result from SAGD production. In order to map these changes, time-lapse multicomponent data were incorporated with rock physics modeling in order to map and interpret changes in Vp/Vs with production. When fluid substitution results and pressure estimations are combined, the resulting velocities are consistent with the core sample modeling done by Kato et al. (2008). These results were then compared with the seismic data in order to identify areas affected by steam, heat, and pressure within the reservoir through time-lapse Vp/Vs. PP time-lapse results show the location of the steam chamber within the reservoir, however these data do not give any information about the effects of pressure or heat. Converted-wave (PS) data can be used to image pressure and viscosity changes in the reservoir. When these data are combined into a Vp/Vs volume, the effects of steam, heat and pressure can be identified. Vp/Vs areas of little to no difference indicate steamed zones while the surrounding areas with large differences indicate heated and pressured zones.

  2. Model development for prediction and mitigation of dissolved oxygen sags in the Athabasca River, Canada

    Energy Technology Data Exchange (ETDEWEB)

    Martin, Nancy, E-mail: nancy@ualberta.ca [Department of Civil and Environmental Engineering, University of Alberta, Edmonton, AB, Canada T6G 2W2 (Canada); McEachern, Preston [Tervita Corporation, AB (Canada); Yu, Tong; Zhu, David Z. [Department of Civil and Environmental Engineering, University of Alberta, Edmonton, AB, Canada T6G 2W2 (Canada)

    2013-01-15

    Northern rivers exposed to high biochemical oxygen demand (BOD) loads are prone to dissolved oxygen (DO) sags in winter due to re-aeration occurring within limited open water leads. Additionally, photosynthesis is reduced by decreased daylight hours, inability of solar radiation to pass through ice, and slower algal growth in winter. The low volumetric flow decreases point-source dilution while their travel time increases. The Athabasca River in Alberta, Canada, has experienced these sags which may affect the aquatic ecosystem. A water quality model for an 800 km reach of this river was customized, calibrated, and validated specifically for DO and the factors that determine its concentration. After validation, the model was used to assess the assimilative capacity of the river and mitigation measures that could be deployed. The model reproduced the surface elevation and water temperature for the seven years simulated with mean absolute errors of < 15 cm and < 0.9 °C respectively. The ice cover was adequately predicted for all seven winters, and the simulation of nutrients and phytoplankton primary productivity were satisfactory. The DO concentration was very sensitive to the sediment oxygen demand (SOD), which represented about 50% of the DO sink in winter. The DO calibration was improved by implementing an annual SOD based on the BOD load. The model was used to estimate the capacity of the river to assimilate BOD loads in order to maintain a DO concentration of 7 mg/L, which represents the chronic provincial guideline plus a buffer of 0.5 mg/L. The results revealed the maximum assimilative BOD load of 8.9 ton/day at average flow conditions, which is lower than the maximum permitted load. In addition, the model predicted a minimum assimilative flow of about 52 m{sup 3}/s at average BOD load. Climate change scenarios could increase the frequency of this low flow. A three-level warning-system is proposed to manage the BOD load proactively at different river

  3. Assessing the potential environmental impact of Athabasca oil sands development in lakes across Northwest Saskatchewan

    Science.gov (United States)

    Ahad, J. M.; Cumming, B. F.; Das, B.; Sanei, H.

    2011-12-01

    The continued development of Canada's Athabasca oil sands poses a significant environmental challenge. Low buffered boreal lakes located downwind of the prevailing eastward wind direction may be threatened by acidification and elevated inputs of airborne contaminants such as polycyclic aromatic hydrocarbons (PAHs). An accurate assessment of the impact that increased levels of bitumen production may have on lakes in the region requires an understanding of the historic variability within these systems prior to at least the past several decades. Here we report concentrations of PAHs, δ13C and δ15N of organic matter (OM), Rock-Eval pyrolysis analyses, and distributions of n-alkanes in dated sediment cores from ten lakes located across NW Saskatchewan. Concentrations of PAHs were relatively low (fires as a principal PAH source. Plots of Hydrogen Index (HI) versus Oxygen Index (OI) fell within a relatively narrow range typical for sediments containing a high content of algal-derived OM. Relatively lower C/N ratios and higher abundances of C17 n-alkane in more recent sediments pointed to an increasingly larger component of algal-derived OM. In all ten lakes δ13C showed gradual upcore depletions that fell within the expected range for fossil fuel combustion (i.e., Suess effect), although this alone may not explain the up to ~3% depletion observed in several of the lakes. In conjunction with the other upcore trends these data may suggest a possible increase in primary productivity over the past several decades in many of the lakes studied. δ15N signatures were more variable, showing upcore increases in some lakes and upcore depletions in others. The increasingly lighter values observed in more recent sediments in some lakes suggest a potential input of depleted bioavailable nitrogen, as might be expected from anthropogenic NOx emissions. This study implies that thus far it appears that oil sands industry related emissions have had only a minor environmental impact on

  4. Impacts of sulphur and nitrogen deposition in western Canada

    Directory of Open Access Journals (Sweden)

    Patrick D. SHAW

    2010-08-01

    Full Text Available The expansion of transportation sectors (road vehicles and marine vessels, industry (e.g., oil and gas and urban centres in western Canada has triggered a growth in research, monitoring and modelling activities investigating the impacts of sulphur and nitrogen deposition on aquatic and terrestrial ecosystems. This special issue presents an overview of related research in British Columbia (Georgia Basin, Alberta (Athabasca Oil Sands Region, Saskatchewan and Manitoba. The research provides a valuable benchmark for future studies across the region and points the way forward for 'acid rain' policies in western Canada.

  5. An integrated numerical framework for water quality modelling in cold-region rivers: A case of the lower Athabasca River.

    Science.gov (United States)

    Shakibaeinia, Ahmad; Kashyap, Shalini; Dibike, Yonas B; Prowse, Terry D

    2016-11-01

    There is a great deal of interest to determine the state and variations of water quality parameters in the lower Athabasca River (LAR) ecosystem, northern Alberta, Canada, due to industrial developments in the region. As a cold region river, the annual cycle of ice cover formation and breakup play a key role in water quality transformation and transportation processes. An integrated deterministic numerical modelling framework is developed and applied for long-term and detailed simulation of the state and variation (spatial and temporal) of major water quality constituents both in open-water and ice covered conditions in the lower Athabasca River (LAR). The framework is based on the a 1D and a 2D hydrodynamic and water quality models externally coupled with the 1D river ice process models to account for the cold season effects. The models are calibrated/validated using available measured data and applied for simulation of dissolved oxygen (DO) and nutrients (i.e., nitrogen and phosphorus). The results show the effect of winter ice cover on reducing the DO concentration, and a fluctuating temporal trend for DO and nutrients during summer periods with substantial differences in concentration between the main channel and flood plains. This numerical frame work can be the basis for future water quality scenario-based studies in the LAR. PMID:27376919

  6. Reconstruction of multi-century flood histories from oxbow lake sediments, Peace-Athabasca Delta, Canada

    Science.gov (United States)

    Wolfe, Brent B.; Hall, Roland I.; Last, William M.; Edwards, Thomas W. D.; English, Michael C.; Karst-Riddoch, Tammy L.; Paterson, Andrew; Palmini, Roger

    2006-12-01

    Floods caused by ice-jams on the Peace River are considered to be important for maintaining hydro-ecological conditions of perched basins in the Peace-Athabasca Delta (PAD), Canada, a highly productive and internationally recognized northern boreal ecosystem. Concerns over the potential linkages between regulation of the Peace River in 1968 for hydroelectric production and low Peace River discharge between 1968 and 1971 during the filling of the hydroelectric reservoir, absence of a major ice-jam flood event between 1975 and 1995, and low water levels in perched basins during the 1980s and early 1990s have sparked numerous environmental studies largely aimed at restoring water levels in the PAD. Lack of sufficient long-term hydrological records, however, has limited the ability to objectively assess the importance of anthropogenic factors versus natural climatic forcing in regulating hydro-ecological conditions of the PAD. Here, we report results of a paleolimnological study on laminated sediments from two oxbow lakes in the PAD, which are located adjacent to major flood distributaries of the Peace River. Sediment core magnetic susceptibility measurements, supported by results from several other physical and geochemical analyses as well as stratigraphic correspondence with recorded high-water events on the Peace River, provide proxy records of flood history spanning the past 180 and 300 years in these two basins. Results indicate that inferred flood frequency has been highly variable over the past 300 years but in decline for many decades beginning as early as the late nineteenth century, well before Peace River regulation. Additionally, several multi-decadal intervals without a major flood have occurred during the past 300 years. While climate-related mechanisms responsible for this variability in flood frequency remain to be determined, as does quantifying the relative roles of river regulation and climate variability on hydro-ecological conditions in the PAD

  7. Implications of a 2 degree C global temperature rise on Canada's water resources : Athabasca River and oil sands development : Great Lakes and hydropower production

    International Nuclear Information System (INIS)

    A globally averaged warming of 2 degrees C is expected to occur by the middle of this century unless significant efforts are made in all countries to reduce greenhouse gas (GHG) emissions. This study examined the impacts of a 2 degrees C global warming on: (1) the Athabasca River and oil sands production; and (2) the Great Lakes and hydropower production. The study was based on previous climate predictions from 6 coupled ocean-atmosphere global climate models. The studies showed that the Athabasca River and the Great Lakes regions have seen increases in mean temperatures and changes in precipitation patterns in recent decades. Flows in the Athabasca River decreased by approximately 20 per cent between 1958 and 2003, and water levels in the Great Lakes have remained consistently low between 1998 and 2001. Under the 2 degrees C warming scenario, minimum flows in the Athabasca River are likely to diminish by 7 to 10 per cent, and water levels in the Great Lakes could fall by 0.08 to 1.18 metres, indicating a potential loss of between 2 to 17 per cent in hydropower production on the St. Lawrence River. An increased frequency and severity of hot spells in summer will increase the region's peak summer energy demand. Results also suggested that the projected rate of water use from the Athabasca River for oil sands projects will become more unsustainable under climate change. The impacts of water withdrawal from oil sands projects will have serious consequences beyond the area of the projects themselves, threatening the productivity of the Peace Athabasca Delta, compromising the sharing of water with downstream jurisdictions in the Mackenzie River system, and ecosystem degradation. The study recommended that Alberta should consider withholding approval of oil sands projects until substantial water conservation measures are introduced. Plans should also be developed for alternative energy projects to compensate for declines in hydropower from the Great Lakes system. It was

  8. Scavenging ratio of polycyclic aromatic compounds in rain and snow at the Athabasca oil sands region

    Directory of Open Access Journals (Sweden)

    L. Zhang

    2014-07-01

    Full Text Available Athabasca oil sands industry in northern Alberta, Canada is a possible source of polycyclic aromatic compounds (PACs. Monitored PACs, including polycyclic aromatic hydrocarbons (PAHs, alkylated PAHs, and dibenzothiophenes, in precipitation and in air at three near-source sites in the Fort MacKay and Fort McMurray area during May 2011 to August 2012 were analyzed to generate a database of scavenging (or washout ratios (Wt for PACs scavenged by both snow and rain. Median precipitation and air concentrations of parent PAHs over the May 2011 to August 2012 period ranged from 0.3–184.9 (chrysene ng L−1 and 0.01–3.9 (naphthalene ng m−3, respectively, which were comparable to literature values. Higher concentrations in precipitation and air were observed for alkylated PAHs and dibenzothiophenes. The median precipitation and air concentrations were 11.3–646.7 (C3-fluoranthene/pyrene ng L−1 and 0.21–16.9 (C3-naphthalene ng m−3, respectively, for alkylated PAHs, and 8.5–530.5 (C4-dibenzothiophene ng L−1 and 0.13–6.6 (C2-dibenzothiophene ng m−3 for dibenzothiophenes and their alkylated derivatives. Median Wt over the measurement period were 6100–1.1 × 106 from snow scavenging and 350–2.3 × 105 from rain scavenging depending on the PAC species. Median Wt for parent PAHs were within the range of those observed at other urban and suburban locations. But Wt for acenaphthylene in snow samples was 2–7 times higher. Some individual snow and rain samples exceeded literature values by a factor of 10. Wt for benzo(apyrene, dibenz(a,hanthracene, and benzo(g,h,iperylene in snow samples had reached 107, which is the maximum for PAH snow scavenging ratios reported in literature. From the analysis of data subsets, Wt for particulate-phase dominant PACs were 14–20 times greater than gas-phase dominant PACs in snow samples and 7–20 times greater than gas-phase dominant PACs in rain samples. Wt from snow scavenging was ∼9 times greater

  9. From evaporated seawater to uranium-mineralizing brines: Isotopic and trace element study of quartz-dolomite veins in the Athabasca system

    Science.gov (United States)

    Richard, Antonin; Boulvais, Philippe; Mercadier, Julien; Boiron, Marie-Christine; Cathelineau, Michel; Cuney, Michel; France-Lanord, Christian

    2013-07-01

    Stable isotope (O, H, C), radiogenic isotope (Sr, Nd) and trace element analyses have been applied to quartz-dolomite veins and their uranium(U)-bearing fluid inclusions associated with Proterozoic unconformity-related UO2 (uraninite) ores in the Athabasca Basin (Canada) in order to trace the evolution of pristine evaporated seawater towards U-mineralizing brines during their migration through sediments and basement rocks. Fluid inclusion data show that quartz and dolomite have precipitated from brines of comparable chemistry (excepted for relatively small amounts of CO2 found in dolomite-hosted fluid inclusions). However, δ18O values of quartz veins (δ18O = 11‰ to 18‰) and dolomite veins (δ18O = 13‰ to 24‰) clearly indicate isotopic disequilibrium between quartz and dolomite. Hence, it is inferred that this isotopic disequilibrium primarily reflects a decrease in temperature between the quartz stage (˜180 °C) and the dolomite stage (˜120 °C). The δ13C values of CO2 dissolved in dolomite-hosted fluid inclusions (δ13C = -30‰ to -4‰) and the δ13C values of dolomite (δ13C = -23.5‰ to -3.5‰) indicate that the CO2 dissolved in the mineralizing brines originated from brine-graphite interactions in the basement. The resulting slight increase in the fluid partial pressure of CO2 (pCO2) may have triggered dolomite precipitation instead of quartz. δ18O values of quartz veins and previously published δ18O values of the main alteration minerals around the U-ores (illite, chlorite and tourmaline) show that quartz and alteration minerals were isotopically equilibrated with the same fluid at ˜180 °C. The REE concentrations in dolomite produce PAAS-normalized patterns that show some similarities with that of UO2 and are clearly distinct from that of the other main REE-bearing minerals in these environments (monazite, zircon and aluminum phosphate-sulfate (APS) minerals). The radiogenic isotope compositions of dolomite (87Sr/86Sri = 0.7053 to 0

  10. Water balance and nutrient status in a reclamation research trial in the Athabasca oil sands region, Alberta

    Energy Technology Data Exchange (ETDEWEB)

    Tan, X.; Dubyk, C.; Kuzmic, F.; Martindale, D. [Shell Canada Energy, Fort McMurray, AB (Canada). Albian Sands Project

    2010-07-01

    This paper discussed a reclamation research trial undertaken in the Athabasca oils sands region to examine water balance and nutrient status in reclamation materials constructed on a northeast-facing slope. The soil covers comprise a peat-mineral mixture overlying clean tailings sand on top of a compacted base of lean soil. Water balance in terms of water runoff, interflow, water storage and evapotranspiration was evaluated by placing field instruments along the slope. For chemistry analyses, runoff and interflow water samples, rainfall, and in-situ water were collected during the growing season. A trend shown in the 5-year data was a decrease in interflow volumes since the start of monitoring. The water balance showed that roughly one-third of the precipitation was lost to runoff. The soil moisture condition remains well above the permanent wilting point during the non-frozen period. In general, the nutrients available in the reclamation system were low. As the vegetation on the slope develops further, the water status and the nutrient status will continue to be monitored. Shifts in the contribution of the different components of water balance are expected as nutrients become more available for plants to uptake.

  11. Compromised metamorphosis and thyroid hormone changes in wood frogs (Lithobates sylvaticus) raised on reclaimed wetlands on the Athabasca oil sands

    International Nuclear Information System (INIS)

    The wet landscape approach to oil sands tailings reclamation in the Athabasca Oil Sands region involves creating wetlands from fluid tailings in mined-out pits. We measured time to metamorphosis, thyroid hormone status, and detoxification enzyme (EROD) induction in Wood frog (Lithobates sylvaticus) tadpoles raised on reclaimed oil sands wetlands of different ages [young (≤7 yr) vs. old (>7 yr)] and compared data with tadpoles raised on reference (control) wetlands. Metamorphosis was delayed or never occurred in tadpoles raised in young tailings; those exposed to older tailings developed similarly to those in reference wetlands. Thyroid hormone disruption likely played an important role in the metamorphosis delay as the T3:T4 ratio was lowest in tadpoles raised in young, tailings-affected wetlands. Our findings suggest tailings wetlands become less toxic with age, and that these amphibians will be able to complete their life cycle in tailing wetlands that have sufficiently detoxified with age. - This work provides guidance for reclamation of oil sands tailings and shows the usefulness of frogs and caging studies in environmental toxicology.

  12. Indicators of early successional trends in environmental condition and community function in constructed wetlands of the Athabasca Oilsands region

    Energy Technology Data Exchange (ETDEWEB)

    Ciborowski, J.; Kovalenko, K. [Windsor Univ., ON (Canada); Dixon, G.; Farwell, A. [Waterloo Univ., ON (Canada); Foote, L.; Mollard, F.; Roy, M. [Alberta Univ., Edmonton, AB (Canada); Smits, J.; Turcotte, D. [Saskatchewan Univ., Saskatoon, SK (Canada)

    2010-07-01

    This presentation reported on a study that compared interannual environmental variation in post-mining Athabasca oil sands landscapes. In particular, it compared biological, ecotoxicological and carbon dynamic aspects of sixteen 5 to 30 year old wetlands with different ages, reclamation materials and stockpiled surface materials such as peat. In addition to determining carbon fluxes, standing stocks of hydrocarbons were measured along with organic substrate, bacterioplankton, phytoplankton, biofilm, macrophytes, litter, zoobenthos, and aquatic insect emergence. Gas fluxes, microbial, plant, zoobenthic, amphibian, and tree swallow nestling production, and stable isotope signatures were used to determine carbon pathways, fluxes and budgets. Coarse taxon richness in reference wetlands reached an asymptote in 5 to 7 years. Richness, composition and emergent plant cover of oilsands-affected wetlands converged over a 15 to 20 year period with reference wetland patterns. The development of emergent but not submergent plant cover and associated biota accelerated with the addition of peat. Water chemistry was found to be more important than sediment in terms of regulating submergent biological properties. The study showed that the most important regulator of community composition may be residual salinity. Compared to more temperate biomes, the successional trends were slower.

  13. Performance of NiWP/Al2O3 catalyst for hydroprocessing of light gas oils derived from Athabasca bitumen

    Energy Technology Data Exchange (ETDEWEB)

    Owusu-Boakye, A.; Ferdous, D.; Dalai, A.K. [Saskatchewan Univ., Saskatoon, SK (Canada). Dept. of Chemistry and Chemical Engineering; Adjaye, J. [Syncrude Canada Ltd., Edmonton, AB (Canada). Edmonton Research Centre

    2004-07-01

    The quality of diesel fuel in terms of cetane number and coloring is diminished if it has a high content of aromatics which cause the formation of undesirable emissions in exhaust gases. These compounds typically occur as mono, di, tri and polyaromatics. In response to strict environmental regulations, middle distillates now have fewer aromatics. Sulphur and nitrogen compounds in diesel fuels also cause the formation of SOx and NOx in the atmosphere, but the aromatic hydrogenation of diesel fuels is more complex than any of the hydrodesulphurization (HDS) or hydrodenitrogenation (HDN) processes. The NiWP/Al{sub 2}O{sub 3} catalyst in a trickle-bed reactor was used under a range of temperature and pressure conditions to study the reactivity of vacuum, atmospheric and hydrocracked light gas oils produced from Athabasca bitumen. The hydrogen feed ratio was kept constant and product samples from different feedstocks were analyzed with respect to sulfur, nitrogen and aromatic content. The study also included a comparison of gasoline selectivity and kinetic parameters for HDS and HDN reactions for the feed materials.

  14. Native bitumens in surficial soils of the Athabasca oil sands region : preliminary characterization and assessment of contaminant mobility

    Energy Technology Data Exchange (ETDEWEB)

    Fleming, M.; Fleming, I. [Saskatchewan Univ., Saskatoon, SK (Canada). Dept. of Civil and Geological Engineering; Headley, J. [Environment Canada, Saskatoon, SK (Canada). National Hydrology Research Centre

    2009-07-01

    A study was conducted on bitumen tarballs located in surficial soils in Alberta's Athabasca region. The tarballs occur in every soil type in the region, and pose a challenge to oil sands operators who hope to use the soils for reclamation activities. Chromatographic analyses have shown that the tarballs contain variable petroleum hydrocarbon concentrations and possess a characteristic chromatographic footprint. The Canadian Council of Ministers of the Environment has characterized the hydrocarbons according to various fractions. A soil-column leaching study is also being conducted by the University of Saskatchewan on heavily-impacted tarball soil under unsaturated conditions. Results of the study have indicated that the soil has low levels of contaminant mobility and degradation. Hydrocarbon concentrations in leachate water are less than 20 per cent of ground water guidelines for Alberta. It was concluded that after respiration over 9 months, the most active soil column in the study degraded only 2.7 g of an estimated 650 g.

  15. Descriptive epidemiology of detected anthrax outbreaks in wild wood bison (Bison bison athabascae) in northern Canada, 1962-2008.

    Science.gov (United States)

    Salb, Amanda; Stephen, Craig; Ribble, Carl; Elkin, Brett

    2014-07-01

    We inventoried and assessed historical anthrax outbreak data from 1962-2008 in wild wood bison (Bison bison athabascae) in Wood Buffalo National Park and the Slave River Lowlands (SRL), Northwest Territories, Canada. We compared these results with a 2010 outbreak in the SRL. Anthrax outbreaks have occurred in 12 of the years between 1962 and 2008 in wild wood bison with 1,515 anthrax deaths detected. The average number of carcasses found each outbreak year was 126 (range 1-363), though local averages varied. The numbers of animals found dead per outbreak declined over the past four decades. Outbreaks varied in duration from 16-44 days (average length 25.5 days). The length of an outbreak was not a determinant of the number of dead bison found, but outbreaks starting in July had more deaths than those staring in June. Males were more likely to be detected in an outbreak, outbreaks were likely not random events, and there was no relationship between outbreak size or length and location. Future surveillance activities may benefit from targeting bulls and planning surveillance activities for more than 3 wk after outbreak detection. Coordinating data collecting and recording efforts between jurisdictions may overcome historical challenges in inconsistent record keeping.

  16. Understanding ozone formation and the radical budget during oil sands plume transport in the Athabasca region of Alberta

    Science.gov (United States)

    Moussa, S. G.; Leithead, A.; Li, S. M.; Wang, D. K.; O'brien, J.; Mittermeier, R. L.; Gordon, M.; Staebler, R. M.; Liu, P.; Liggio, J.

    2015-12-01

    The sources of ozone and hydroxyl radicals (OH) in the Alberta oil sands (OS) region have not previously been well characterized. In the summer of 2013, airborne measurements of various volatile organic compounds (VOCs), nitrogen oxides (NOx = NO2+NO) and ozone were made in the Athabasca OS region between August 13 and September 7, 2013. Proton Transfer Reaction-Time of Flight-Mass Spectrometry (PTR-ToF-MS) and whole air samples were used to measure VOCs. A box model incorporating the Master Chemical Mechanism (MCM v3.3), was constrained by measured chemical species and meteorological parameters and used to simulate the evolution of an OS plume. In doing so, an improved understanding of the chemical factors controlling the radical budget and the evolution of ozone in oil sands plumes is achieved. Our results indicate that approximately 20% of the in-plume generated OH radicals are derived from primary sources (HCHO, O3 and HONO photolysis). The remaining OH is derived from the recycling of hydroperoxyl radical (HO2). The HO2 and alkyl peroxyl radical (RO2) chemistry leads to 35% of the ozone formation in the plume, while the main sink for ozone in the plume was via reactions with alkenes (anthropogenic and biogenic). The results of this work will help to characterize ozone formation and the factors influencing its atmospheric fate in the oil sands region.

  17. Athabasca oil sands process water: characterization by atmospheric pressure photoionization and electrospray ionization fourier transform ion cyclotron resonance mass spectrometry.

    Science.gov (United States)

    Barrow, Mark P; Witt, Matthias; Headley, John V; Peru, Kerry M

    2010-05-01

    The Athabasca oil sands in Canada are a less conventional source of oil which have seen rapid development. There are concerns about the environmental impact, with particular respect to components in oil sands process water which may enter the aquatic ecosystem. Naphthenic acids have been previously targeted for study, due to their implications in toxicity toward aquatic wildlife, but it is believed that other components, too, contribute toward the potential toxicity of the oil sands process water. When mass spectrometry is used, it is necessary to use instrumentation with a high resolving power and mass accuracy when studying complex mixtures, but the technique has previously been hindered by the range of compounds that have been accessible via common ionization techniques, such as electrospray ionization. The research described here applied Fourier transform ion cyclotron resonance mass spectrometry in conjunction with electrospray ionization and atmospheric pressure photoionization, in both positive-ion and negative-ion modes, to the characterization of oil sands process water for the first time. The results highlight the need for broader characterization when investigating toxic components within oil sands process water. PMID:20359201

  18. Indicators of early successional trends in environmental condition and community function in constructed wetlands of the Athabasca Oilsands region

    International Nuclear Information System (INIS)

    This presentation reported on a study that compared interannual environmental variation in post-mining Athabasca oil sands landscapes. In particular, it compared biological, ecotoxicological and carbon dynamic aspects of sixteen 5 to 30 year old wetlands with different ages, reclamation materials and stockpiled surface materials such as peat. In addition to determining carbon fluxes, standing stocks of hydrocarbons were measured along with organic substrate, bacterioplankton, phytoplankton, biofilm, macrophytes, litter, zoobenthos, and aquatic insect emergence. Gas fluxes, microbial, plant, zoobenthic, amphibian, and tree swallow nestling production, and stable isotope signatures were used to determine carbon pathways, fluxes and budgets. Coarse taxon richness in reference wetlands reached an asymptote in 5 to 7 years. Richness, composition and emergent plant cover of oilsands-affected wetlands converged over a 15 to 20 year period with reference wetland patterns. The development of emergent but not submergent plant cover and associated biota accelerated with the addition of peat. Water chemistry was found to be more important than sediment in terms of regulating submergent biological properties. The study showed that the most important regulator of community composition may be residual salinity. Compared to more temperate biomes, the successional trends were slower.

  19. Compromised metamorphosis and thyroid hormone changes in wood frogs (Lithobates sylvaticus) raised on reclaimed wetlands on the Athabasca oil sands

    Energy Technology Data Exchange (ETDEWEB)

    Hersikorn, Blair D., E-mail: blair.hersikorn@usask.c [Toxicology Centre, University of Saskatchewan, 44 Campus Drive, Saskatoon, Saskatchewan, S7N 5B3 (Canada); Smits, Judit E.G., E-mail: judit.smits@ucalgary.c [Faculty of Veterinary Medicine, University of Calgary, 3280 Hospital Drive NW, Calgary, Alberta, T2N 4Z6 (Canada)

    2011-02-15

    The wet landscape approach to oil sands tailings reclamation in the Athabasca Oil Sands region involves creating wetlands from fluid tailings in mined-out pits. We measured time to metamorphosis, thyroid hormone status, and detoxification enzyme (EROD) induction in Wood frog (Lithobates sylvaticus) tadpoles raised on reclaimed oil sands wetlands of different ages [young ({<=}7 yr) vs. old (>7 yr)] and compared data with tadpoles raised on reference (control) wetlands. Metamorphosis was delayed or never occurred in tadpoles raised in young tailings; those exposed to older tailings developed similarly to those in reference wetlands. Thyroid hormone disruption likely played an important role in the metamorphosis delay as the T3:T4 ratio was lowest in tadpoles raised in young, tailings-affected wetlands. Our findings suggest tailings wetlands become less toxic with age, and that these amphibians will be able to complete their life cycle in tailing wetlands that have sufficiently detoxified with age. - This work provides guidance for reclamation of oil sands tailings and shows the usefulness of frogs and caging studies in environmental toxicology.

  20. Radionuclide levels in fish from Lake Athabasca February 1993. Northern River Basins Study project report no.26

    International Nuclear Information System (INIS)

    The Northern River Basins Study was initiated through the 'Canada-Alberta-Northwest Territories Agreement Respecting the Peace-Athabasca-Slave River Basin Study, Phase II - Technical Studies' which was signed September 27, 1991. The purpose of the study is to understand and characterize the cumulative effects of development on the water and aquatic environment of the Study Area by coordinating with existing programs and undertaking appropriate new technical studies. This publication reports the method and findings of particular work conducted as part of the Northern River Basins Study. As such, the work was governed by a specific terms of reference and is expected to contribute information about the Study Area within the context of the overall study as described by the Study Final Report. This report has been reviewed by the Study Science Advisory Committee in regards to scientific content and has been approved by the Study Board of Directors for public release. It is explicit in the objectives of the Study to report the results of technical work regularly to the public. This objective is served by distributing project reports to an extensive network of libraries, agencies, organizations and interested individuals and by granting universal permission to reproduce the material. This report contains referenced data obtained from external to the Northern River Basins Study. Individuals interested in using external data must obtain permission to do so from the donor agency. (author). 47 refs., 9 tabs., 2 figs

  1. Nuclear energy as a subsurface heavy oil recovery technique (Project Athabasca). [Alberta

    Energy Technology Data Exchange (ETDEWEB)

    Moore, S.D.

    1976-01-01

    Nuclear energy may become an acceptable thermal recovery technique in the subsurface heavy oil deposits of N. Alberta. The subterranean detonation cavern also may facilitate secondary and tertiary in situ recovery methods, steam injection, and fireflood. Less than 5% of Canada's heavy oil reserves, variously estimated at up to 600-billion bbl, are producible by surface mining. Recovery theory is simple--the nuclear detonation releases both thermal and shock energy to convert otherwise immobile viscous heavy oil deposits into conventionally recoverable hydrocarbons. The proposed Project Athabaska, to employ a 10-kt device, requires exhaustive planning to overcome formidable technical, political, and environmental concerns. Technically, precedent shows that project cost is practically indepencent of yield. The crude oil production unit will comprise a central detonation or emplacement well and several peripheral production wells. Each successive recovery technique will benefit from vastly improved permeability resulting from the prior recovery method.

  2. Geology and mineralogy of the Key Lake U-Ni deposits, northern Saskatchewan, Canada

    International Nuclear Information System (INIS)

    The Key Lake deposit is located at the southeastern rim of the Athabasca Basin in northern Saskatchewan. The first orebody (the Gartner) was discovered in the summer of 1975, and the second (the Deilmann) one year later. At the present stage of investigation - drilling still continues -the following features are apparent. Both orebodies occur in approximately northeast-southwest-striking fracture zones, which affected the crystalline basement as well as the overlying Athabasca sandstone formation. The country rock comprises, from top to bottom, various deposits of glacial origin, the Athabasca sandstone and metasediments of the Wollaston Fold Belt. The main mineralization consists of uranium oxides and nickel sulphides/arsenides. Rarely, some gangue occurs in the form of quartz and carbonates. Drilling results to date indicate, for the Gartner orebody, a length of 1500 m, a width of 10 to 40 m, a depth of 80 m and a grade of up to 45% U3O8 + 45% Ni; and, for the Deilmann orebody, a minimum length of 800 m, a width of 10 to more than 100 m, a depth of 150 m and contents of up to 20% U3O8 + 25% Ni. The thickness of the glacial overburden varies between 20 and 100 m. Precise reserve calculations are being made, but several difficulties have delayed their completion. The ore is tectonically and lithologically controlled. The presence of geothermometers, as tetragonal α-U3O7 (formation temperature, 1350C) and bravoite (1370C), in association with intergrowth textures of other ore minerals, points to a low-temperature origin. (author)

  3. Dissolved organic carbon in a constructed and natural fens in the Athabasca oil sands region, Alberta, Canada.

    Science.gov (United States)

    Khadka, Bhupesh; Munir, Tariq M; Strack, Maria

    2016-07-01

    In the Athabasca oil sands region near Fort McMurray, Alberta, Canada, peatlands are disturbed extensively in order to recover bitumen below the surface. Hence, following oil sands mining, landscape reclamation is a part of the mine closure process in order to return functioning ecosystems, including peatlands, to the region. This study was conducted at a pilot fen reclamation project and three other diverse natural (poor, rich and saline) fens in the oil sands region during the growing seasons of 2013 and 2014, the first and second year post-construction. Ecosystem functioning of the constructed fen (CF) was evaluated with reference to natural fens based on pore water dissolved organic carbon (DOC) concentration and chemistry. Significant variation of DOC concentration among the reference fens was observed, varying from an average of 42.0mg/L at the rich fen (RF) to 70.8mg/L at the saline fen (SF). Dissolved organic carbon concentration at CF was significantly lower than at all reference fens, but increased significantly over the first two years. Seasonal variation of DOC concentration was also observed in each site with concentration increasing over the growing season. At CF, DOC was comprised of larger, more humic and complex aromatic compounds than reference fens in the first year post-construction based on its spectrophotometric properties; however, these differences were reduced in the second year. Initial DOC concentration and chemistry at CF was indicative of the source being largely the peat placed during fen construction. Changes in chemistry and increasing concentration of DOC in the second growing season likely resulted from increasing inputs from plants established on site. These results suggest that DOC concentration is likely to increase in future at CF as vascular plant productivity increases and in response to salinity sourced from tailing sand used to construct the catchment. PMID:27037879

  4. And now for something completely different: condensation induced water hammer and steam assisted gravity drainage in the Athabasca Oil Sands

    International Nuclear Information System (INIS)

    Most people will have been exposed to some aspect of the debate about the Athabasca Oil Sands in North-Eastern Alberta and the significant role that the oil sands are expected to play in supplying conventional fossil fuels. Part of the bitumen is recovered from mines and part is recovered from in situ projects utilizing the Steam Assisted Gravity Drainage Process (SAGD). SAGD utilizes a considerable amount of steam, that is injected into geological formations. Hot water, bitumen and some vapour are recovered from the production wells. With significant steam generation, transmission and injection, there is the very real possibility of condensation induced water hammers. There have been a number of catastrophic failures to date. Two major failures will be highlighted: MEG Energy had a steam distribution line fail at the Christina Lake project. Large parts of the pipe, weighing some 2500 kg, were thrown some 800 meters into the bush during the failure; and, Total had a steam release (blowout) at their Joslyn property due to a loss of caprock containment. A number of causes have been postulated. While it is agreed that there was sufficient downhole pressure to hydraulically fracture the formation, questions have been raised about the contribution that condensation induced water hammer made. The situations that have occurred will be outlined, along with some preliminary thermal hydraulic work. The intent of the paper is to provide interesting background information on the in situ oil sands industry. More importantly, to show some interesting and broader applications of thermalhydraulics developed in the nuclear industry. The expertise developed may have potential markets, with some adaptation, to the oil sands industry. Finally, there has been some discussion about using nuclear power for steam generation in the oil sands. (author)

  5. Application of solid state silicon-29 and carbon-13 nuclear magnetic resonance spectroscopy to the characterization of inorganic matter-humic complexes in Athabasca oil sands

    International Nuclear Information System (INIS)

    In Athabasca oil sands there is a fraction of non-crystalline solids tightly bound to humic matter. It is believed, that the presence of this fraction, which resists subsequent wetting by water, introduces serious problems in bitumen recovery when using water based processes. In the present work, 29Si and 13C solid state magic angle spinning (MAS) NMR techniques were applied to characterize these solids which were isolated from Athabasca oil sands of estuarine and marine origin. On the basis of 29Si results it is suggested that there is a short-range disorder in these samples. It is also shown that aluminum is present in the nearest-neighbor environment of the silicon atoms, thus demonstrating that these solids are comprised of disordered alumino-silicates (allophanes). 13C CP/MAS NMR spectra of demineralized inorganic matter-humic complexes derived from both estuarine and marine oil sands indicate that the distribution of carbon types in each region of the spectra is similar, with aromatic carbon being the predominant type of carbon

  6. Physiological and biochemical responses of small fish exposed to Athabasca oil sands sediment

    International Nuclear Information System (INIS)

    A study was conducted to determine the influence of naturally occurring oil sands related compounds on the reproductive function and hepatic responses of fish. Wild fish, both exposed and unexposed to the compounds in question, were collected along with sediments for laboratory testing. The study showed that in vitro gonadal incubation levels of steroid production were lower at the tributary sites within the oil sands deposits. One indicator of exposure to oil sands related compounds (hepatic 7-ethoxyresorufin-O-deethylase activity) was shown to be 5 times higher at the same sites. In addition, slimy sculpin were exposed to sediment samples from the Steepbank River site for 4 to 8 days to evaluate the absorption of the indicator. The indicator in exposed fish was found to be comparable to that measured in fish native to the oil sands area. The study was not capable of predicting an altered ability of gonadal tissue of exposed fish to produce steroid hormones in vitro. It was concluded that future development could compromise the reproductive health of fish in the area

  7. Compound-specific radiocarbon analysis to evaluate the contribution of Peace River floodings to the PAH background in the Peace-Athabasca Delta

    Science.gov (United States)

    Jautzy, J. J.; Ahad, J. M.; Hall, R. I.; Wiklund, J. A.; Gobeil, C.; Savard, M. M.

    2013-12-01

    The oil sands of Northern Alberta, Canada are one of the largest hydrocarbon reserves in the world. The rapid growth of the bitumen exploitation in this region involves large scale mining infrastructure, raising questions about the environmental impact of these operations. One of the main issues is the emission of hazardous organic compounds such as polycyclic aromatic hydrocarbons (PAHs). PAHs, which are found naturally in petroleum, are also produced through incomplete combustion and diagenesis of organic matter. The complex nature of the surrounding geology (natural levels of bitumen) requires tools able to discriminate sources of pollutants. The establishment of the PAH background is crucial in order to investigate the impacts of oil sands mining in the Athabasca region. Here we present a new approach to discriminate the sources of alkylated PAHs (fossil or modern biomass) and their relative contributions. Using a dated sediment sequence from a lake situated in the Peace-Athabasca Delta periodically flooded by the Peace River, 6 different groups of parent and alkylated PAHs were extracted and collected by preparative capillary gas chromatography (PCGC) for natural abundance radiocarbon (14C) measurement. Three grouped layers each comprising approximately 10 years of sedimentation and spanning the period of mining operations (i.e., the past 40 years) were analyzed. We report here the first use of 14C measurements on alkylated PAHs extracted from lake sediments. Our results showed low radiocarbon content for all alkylated and parent PAHs analyzed in the three sediment layers. However, a slight trend toward a more modern PAH input can be seen up-core. PAH isomers ratios pointed to a major influence of petroleum input in the entire lake sequence, supporting the predominance of a fossil carbon source as indicated by the low radiocarbon contents. As the Peace River cuts through the Peace oil sands formation, our results can be explained by the main contribution of

  8. Landform design for a fen wetland on a tailings sand deposit in northern Alberta

    Energy Technology Data Exchange (ETDEWEB)

    McKenna, G.T.; Papini, A.G.; Scordo, E.B. [BGC Engineering Inc., Vancouver, BC (Canada); Wytrykush, C. [Syncrude Canada Ltd., Edmonton, AB (Canada)

    2010-07-01

    This paper discussed one of the first fens to be established in a post-mining area of the Athabasca oil sands region. The entire watershed is specifically designed to support a wetland, and it will be constructed on a soft tailings deposit. A fen is a peat-accumulating wetland with a water table that is at, or close to, the surface consisting of mineral-saturated water coming from either groundwater or surface water. In order to monitor and adjust the fen design for field conditions, a full hydrological site investigation was launched together with parallel research programs involving the creation of a conservative landform design with controls over surface water and groundwater seepage inputs. Controlling the salinity of fen waters from tailings consolidation and seepage over time is a critical component to fen design. There are a limited number of documented examples of large-scale constructed fen wetlands.

  9. Variation in immune function, body condition, and feather corticosterone in nestling Tree Swallows (Tachycineta bicolor) on reclaimed wetlands in the Athabasca oil sands, Alberta, Canada

    Energy Technology Data Exchange (ETDEWEB)

    Jane Harms, N., E-mail: naomi.harms@usask.c [University of Saskatchewan, Western College of Veterinary Medicine, Department of Veterinary Pathology, 52 Campus Drive, Saskatoon, SK, S7N 5B4 (Canada); Fairhurst, Graham D., E-mail: graham.fairhurst@usask.c [University of Saskatchewan, Department of Biology, 112 Science Place, Saskatoon, SK, S7N 5E2 (Canada); Bortolotti, Gary R., E-mail: gary.bortolotti@usask.c [University of Saskatchewan, Department of Biology, 112 Science Place, Saskatoon, SK, S7N 5E2 (Canada); Smits, Judit E.G., E-mail: judit.smits@usask.c [University of Saskatchewan, Western College of Veterinary Medicine, Department of Veterinary Pathology, 52 Campus Drive, Saskatoon, SK, S7N 5B4 (Canada)

    2010-03-15

    In the Athabasca oil sands region of northern Alberta, mining companies are evaluating reclamation using constructed wetlands for integration of tailings. From May to July 2008, reproductive performance of 40 breeding pairs of tree swallows (Tachycineta bicolor), plus growth and survival of nestlings, was measured on three reclaimed wetlands on two oil sands leases. A subset of nestlings was examined for i) feather corticosterone levels, ii) delayed-type hypersensitivity response, and iii) innate immune function. Nestlings on one of two wetlands created with oil sands process affected material (OSPM) were heavier and had greater wing-lengths, and mounted a stronger delayed-type hypersensitivity response compared those on the reference wetland. Corticosterone was significantly higher in male nestlings on one of two OSPM-containing wetland compared to the reference wetland. Body condition of 12-day-old female nestlings was inversely related to feather corticosterone. Under ideal weather conditions, reclaimed wetlands can support healthy populations of aerially-insectivorous birds. - Under ideal weather conditions, tree swallow nestlings on reclaimed OSPM-affected wetlands are in good body condition and mount strong cell-mediated immune responses.

  10. Variation in immune function, body condition, and feather corticosterone in nestling Tree Swallows (Tachycineta bicolor) on reclaimed wetlands in the Athabasca oil sands, Alberta, Canada

    International Nuclear Information System (INIS)

    In the Athabasca oil sands region of northern Alberta, mining companies are evaluating reclamation using constructed wetlands for integration of tailings. From May to July 2008, reproductive performance of 40 breeding pairs of tree swallows (Tachycineta bicolor), plus growth and survival of nestlings, was measured on three reclaimed wetlands on two oil sands leases. A subset of nestlings was examined for i) feather corticosterone levels, ii) delayed-type hypersensitivity response, and iii) innate immune function. Nestlings on one of two wetlands created with oil sands process affected material (OSPM) were heavier and had greater wing-lengths, and mounted a stronger delayed-type hypersensitivity response compared those on the reference wetland. Corticosterone was significantly higher in male nestlings on one of two OSPM-containing wetland compared to the reference wetland. Body condition of 12-day-old female nestlings was inversely related to feather corticosterone. Under ideal weather conditions, reclaimed wetlands can support healthy populations of aerially-insectivorous birds. - Under ideal weather conditions, tree swallow nestlings on reclaimed OSPM-affected wetlands are in good body condition and mount strong cell-mediated immune responses.

  11. TUBERCULOSIS AND BRUCELLOSIS IN WOOD BISON (BISON BISON ATHABASCAE) IN NORTHERN CANADA: A RENEWED NEED TO DEVELOP OPTIONS FOR FUTURE MANAGEMENT.

    Science.gov (United States)

    Shury, Todd K; Nishi, John S; Elkin, Brett T; Wobeser, Gary A

    2015-07-01

    Effective, long-term strategies to manage the threat of bovine tuberculosis and brucellosis spillback from northern, diseased bison to the Canadian cattle herd and adjacent disease-free wood bison (Bison bison athabascae) herds have eluded policy makers in recent decades. A controversial plan to depopulate infected herds and repopulate them with disease-free wood bison was rejected in 1990 because of significant public concern. Since then, technical advances in vaccine technology, genetic salvage, selective culling, and diagnostic test development have occurred. Containment strategies to reduce further spread of these diseases are a necessary first step; recent progress has been made in this area, but challenges remain. This progress has produced more options for management of these herds in northern Canada, and it is time to consider wood bison conservation and long-term disease eradication as equally important goals that must satisfy concerns of conservation groups, agriculture sectors, aboriginal groups, and the general public. Management of wildlife disease reservoirs in other areas, including Yellowstone and Riding Mountain national parks, has demonstrated that effective disease management is possible. Although combinations of different strategies, including vaccination, genetic salvage techniques, and selective culling, that use sensitive and specific diagnostic tests may offer alternatives to depopulation/repopulation, they also have logistic constraints and cost implications that will need consideration in a multistakeholder, collaborative-management framework. We feel the time is right for this discussion, so a long-term solution to this problem can be applied.

  12. Geologic setting of the East Alligator uranium deposits and prospects

    International Nuclear Information System (INIS)

    Since 1969, four major uranium deposits and a number of important prospects have been discovered in the East Alligator region of the Northern Territory. The region is now considered to be one of the most prospective in the world for locating further uranium reserves. Exploration activity in recent years, however, has been hampered as a result of government delays in processing new applications for exploration tenements. It is expected that this situation will continue until such time as the government has resolved the political problems associated with establishment of the Kakadu National Park, Aboriginal Land Rights and current mine development in the area. This paper briefly describes the geology of some deposits and prospects. It should be noted that certain prospects have not been included in this discussion because of the lack of sufficient data. The common geologic features are summarized to determine the most important similarities and possible ore controls. A brief comparison with the Athabasca Basin in Canada is presented. The regional geology has been presented by other authors (Needham and Stuart-Smith, this volume) and will not be repeated in this discussion. In summary, the authors hope to provide a greater insight into the different geologic environments of uranium mineralization in the East Alligator region and in this way aid in elucidating the metallogenesis

  13. NONMETALS DEPOSITS

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    <正>20102406 Chen Gang(China University of Geosciences,Beijing 100083,China);Li Fengming Discussion on Geological Characteristics and Genesis of Yuquanshan Graphite Deposit of Xinjiang(Xinjiang Geology,ISSN1000-8845,CN65-1092/P,27(4),2009,p.325-329,4 illus.,4 tables,5 refs.)Key words:graphite deposit,XinjiangYuquanshan graphite deposit of Xinjiang occurs in mica-quartz schist of Xingeer Information which belongs to Xinditate Group of Lower Pt in Kuluketage Block of Tarim paleo-continent,and experiences two mineralizing periods of

  14. NONMETALS DEPOSITS

    Institute of Scientific and Technical Information of China (English)

    2014-01-01

    <正>20140876 Gao Junbo(College of Resources and Environmental Engineering,Guizhou University,Guiyang 550025,China);Yang Ruidong Study on the Strontium Isotopic Composition of Large Devonian Barite Deposits from Zhenning,Guizhou Province(Geochimica,

  15. NONMETALS DEPOSITS

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    <正>20122457 Cai Jianshe ( Fujian Institute of Geological Survey and Drawing,Fuzhou 350011,China ) On the Geologic Characteristics and Genesis of the Longtangsi Fluorite Deposit in Pucheng County,Fujian Province ( Geology of Fujian,ISSN1001-3970,CN35-1080 / P,30 ( 4 ), 2011,p.301-306,3illus.,1table,6 refs.,with English abstract ) Key words:fluorspar deposit,Fujian Province

  16. NONMETALS DEPOSITS

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    <正>20110947 Chen Xinglong(Guizhou Bureau of Nonferrous Metal and Nuclear Geology,Guiyang 550005,China);Gong Heqiang Endowment Factors and Development & Utilization Strategy of Bauxite Resource in North Guizhou Province(Guizhou Geology,ISSN1000-5943,CN52-1059/P,27(2),2010,p.106-110,6 refs.,with English abstract)Key words:bauxite deposit,Guizhou Province20110948 Dang Yanxia(Mineral Resource & Reservoir Evaluation Center,Urumiq 830000,China);Fan Wenjun Geological Features and a Primary Study of Metallogenesis of the Wucaiwang Zeolite Deposit,Fuyun County(Xinjiang Geology,ISSN1000-8845,CN65-1092/P,28(2),2010,p.167-170,2 illus.,1 table,5 refs.)Key words:zeolite deposit,Xinjiang Nearly all zeolite deposits in the world result from low-temperature-alteration of glass-bearing volcanic rocks.The southern slope of the Kalamali Mountain is one of the regions where medium to acid volcanics are major lithological type,thus it is a preferred area to look for zeolite deposit.The Wucaiwang zeolite ore district consists of mainly acid volcanic-clastic rocks.

  17. METALS DEPOSITS

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    <正>20091594 Bao Yafan(The Third Geologic Survey of Jilin Province,Siping 136000,China);Liu Yanjun Relations between Bashenerxi Granite,West Dongkunlun and Baiganhu Tungsten-Tin Deposit(Jilin Geology,ISSN1001-2427,CN22-1099/P,27(3),2008,p.56-59,67,5 illus.,2 tables,7 refs.,with English abstract)Key words:tungsten ores,tin ores,monzogranite,Kunlun Mountains20091595 Chen Fuwen(Yichang Institute of Geology and Mineral Resources,China Geological Survey,Yichang 443003,China);Dai Pingyun Metallogenetic and Isotopic Chronological Study on the Shenjiaya Gold Deposit in Xuefeng Mountains,Hunan Province(Acta Geologica Sinica,ISSN0001-5717,CN11-1951/P,82(7),2008,p.906-911,3 illus.,2 tables,30 refs.)Key words:gold ores,HunanThe Shenjiaya gold deposit is a representative one

  18. METALS DEPOSITS

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    <正>20111705 An Junbo(Team 603,Bureau of Nonferrous Metals Geological Exploration of Jilin Province,Hunchun 133300,China);Xu Renjie Geological Features and Ore Genesis of Baishilazi Scheelite Deposit in Yanbian Area(Jilin Geology,ISSN1001-2427,CN22-1099/P,29(3),2010,p.39-43,2 illus.,2 tables,7 refs.)Key words:tungsten ores,Jilin ProvinceThe Baishilazi scheelite deposit is located in contacting zone between the marble of the Late Palaeozoic Qinglongcun Group and the Hercynian biotite granite.The vein and lenticular major ore body is obviously controlled by NE-extending faults and con

  19. METALS DEPOSITS

    Institute of Scientific and Technical Information of China (English)

    2013-01-01

    <正>20131565 Cai Lianyou(No.332 Geological Team,Bureau of Geology and Mineral Resources Exploration of Anhui Province,Huangshan 245000,China);Weng Wangfei Geological Characteristics and Genesis Analysis of Guocun Navajoite Deposit in South Anhui Province(Mineral Resources and Geology,

  20. METALS DEPOSITS

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    <正>20102341 Bao Peisheng(Institute of Geology,Chinese Academy of Geological Science,Beijing 100037,China)Further Discussion on the Genesis of the Podiform Chromite Deposits in the Ophiolites-Questioning about the Rock:Melt Interaction Metallogeny(Geological Bulletin of China,ISSN1671-2552,CN11-4648/P,28(12),2009,p.1741-1761

  1. NONMETALS DEPOSITS

    Institute of Scientific and Technical Information of China (English)

    2013-01-01

    <正>20131601 Gao Junbo(College of Resources and Environmental Engineering,Guizhou University,Guiyang 550003,China);Yang Ruidong Hydrothermal Venting-Flowing Sedimentation Characteristics of Devonian Barite Deposits from Leji,Zhenning County,Guizhou Province(Acta Sedimentologica Sinica,ISSN1000-0550,CN62-1038/P,30(3),

  2. METALS DEPOSITS

    Institute of Scientific and Technical Information of China (English)

    2015-01-01

    20150904An Fang(State Key Laboratory of Continental Dynamics,Department of Geology,Northwest University,Xi’an 710069,China);Wang Juli Skarn Mineral Assemblage in Representative Ore Districts of Sayak Copper Orefield,Kazakhstan,and Its Genetic Implications(Mineral Deposits,ISSN0258-7106,CN11-1965/P,33(3),2014,p.521-540,

  3. Characterizing baseline concentrations, proportions, and processes controlling deposition of river-transported bitumen-associated polycyclic aromatic compounds at a floodplain lake (Slave River Delta, Northwest Territories, Canada).

    Science.gov (United States)

    Elmes, Matthew C; Wiklund, Johan A; Van Opstal, Stacey R; Wolfe, Brent B; Hall, Roland I

    2016-05-01

    Inadequate knowledge of baseline conditions challenges ability for monitoring programs to detect pollution in rivers, especially where there are natural sources of contaminants. Here, we use paleolimnological data from a flood-prone lake ("SD2", informal name) in the Slave River Delta (SRD, Canada), ∼ 500 km downstream of the Alberta oil sands development and the bitumen-rich McMurray Formation to identify baseline concentrations and proportions of "river-transported bitumen-associated indicator polycyclic aromatic compounds" (indicator PACs; Hall et al. 2012) and processes responsible for their deposition. Results show that indicator PACs are deposited in SD2 by Slave River floodwaters in concentrations that are 45 % lower than those in sediments of "PAD31compounds", a lake upstream in the Athabasca Delta that receives Athabasca River floodwaters. Lower concentrations at SD2 are likely a consequence of sediment retention upstream as well as dilution by sediment influx from the Peace River. In addition, relations with organic matter content reveal that flood events dilute concentrations of indicator PACs in SD2 because the lake receives high-energy floods and the lake sediments are predominantly inorganic. This contrasts with PAD31 where floodwaters increase indicator PAC concentrations in the lake sediments, and concentrations are diluted during low flood influence intervals due to increased deposition of lacustrine organic matter. Results also show no significant differences in concentrations and proportions of indicator PACs between pre- (1967) and post- (1980s and 1990 s) oil sands development high flood influence intervals (t = 1.188, P = 0.279, d.f. = 6.136), signifying that they are delivered to the SRD by natural processes. Although we cannot assess potential changes in indicator PACs during the past decade, baseline concentrations and proportions can be used to enhance ongoing monitoring efforts.

  4. Examination of mercury and organic carbon dynamics from a constructed fen in the Athabasca oil sands region, Alberta, Canada using in situ and laboratory fluorescence measurements

    Science.gov (United States)

    Oswald, C.; Carey, S. K.

    2013-12-01

    In the Athabasca oil sands region, mined landscapes must be reclaimed to a functioning natural ecosystem as part of the mine closure process. To test wetland construction techniques on oil sands tailings, 55 ha of mined landscape on the Syncrude Canada Ltd. property is being reclaimed to a watershed containing a graminoid fen. The 18 ha constructed fen consists of an approximately 50 cm thick peat-mineral soil layer separated from underlying tailings sand by a thin layer of clay till. The water table in the fen is maintained by pumping water into the fen from a nearby lake and controlling outflow with under-drains. The objective of this study was to assess total mercury (THg) and methyl mercury (MeHg) concentration dynamics in water exported from the fen in relation to organic carbon quantity and composition. Water quality data from summer 2012 when the fen pumps were first turned on show that dissolved organic carbon (DOC) concentrations are on average twice as high in water flowing through the underlying tailings sand aquifer (median: 42.0 mg/L) compared to DOC concentrations in water flowing through the fen peat package (median: 20.3 mg/L). Given these DOC concentrations, filtered THg concentrations are very low (median values are 0.81 ng/L and 0.17 ng/L for water flowing through the fen peat and sand tailings, respectively) compared to concentrations reported for other boreal wetlands. Although a relationship was identified between filtered THg and DOC (r2=0.60), its slope (0.06 ng Hg/mg C) is an order-of-magnitude smaller than the typical range of slopes found at other wetland sites potentially suggesting a small pool of mercury in the peat and/or limited partitioning of mercury into solution. Filtered MeHg concentrations in all water samples are near the limit of detection and suggest that biogeochemical conditions conducive to methylation did not exist in the fen peat or tailings sand at the time of sampling. In addition to these baseline THg and Me

  5. NONMETALS DEPOSITS

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    <正>20111761 Chen Hua(115 Geological Party,Guizhou Bureau of Geology and Mineral Exploration & Development,Guiyang 551400,China);Deng Chao Analysis on the Metallogenic Environment of Maochang Bauxite in Guizhou Province(Guizhou Geology,ISSN1000-5943,CN52-1059/P,27(3),2010,p.198-201,2 illus.,1 table,8 refs.)Key words:bauxite deposit,Guizhou Province By long time physical and chemical process,the carbonate rock after Central Guizhou uplidft,becomes red clay,after further weathering,the red clay decomposed into the oxide,hydroxide of Al and Fe,in the dissolution hole and depression,it concentrates primary fragmentary tight and earthy karst bauxite ore.Because the variation of landform,it decomposes and cracks again,affords the material source

  6. Deposit model for volcanogenic uranium deposits

    Science.gov (United States)

    Breit, George N.; Hall, Susan M.

    2011-01-01

    Volcanism is a major contributor to the formation of important uranium deposits both close to centers of eruption and more distal as a result of deposition of ash with leachable uranium. Hydrothermal fluids that are driven by magmatic heat proximal to some volcanic centers directly form some deposits. These fluids leach uranium from U-bearing silicic volcanic rocks and concentrate it at sites of deposition within veins, stockworks, breccias, volcaniclastic rocks, and lacustrine caldera sediments. The volcanogenic uranium deposit model presented here summarizes attributes of those deposits and follows the focus of the International Atomic Energy Agency caldera-hosted uranium deposit model. Although inferred by some to have a volcanic component to their origin, iron oxide-copper-gold deposits with economically recoverable uranium contents are not considered in this model.

  7. Structural and hydrothermal modification of the Gaertner uranium deposit, Key Lake, Saskatchewan, Canada

    International Nuclear Information System (INIS)

    The Key Lake uranium deposits are located at the southeastern edge of the Athabasca Basin, approximately 240 km north of La Ronge, Saskatchewan. Key Lake Mining Corporation is at present the world's largest uranium producer with an annual rated production of approximately 12 million pounds of U3O8. The Gaertner deposit consists of massive aggregates of uranium and nickel minerals immediately above the Early/Middle Proterozoic unconformity at its intersection with the Key Lake structural zone. Peripheral ore shoots extend along fractures into the wall rocks. The main ore minerals are uraninite and coffinite which are accompanied by Ni-arsenides, Ni-sulpharsenides and Ni-, Fe-, Pb-, Co- and Cu-sulphides. Radially textured anisotropic uraninite in the Gaertner deposit represents the oldest mineralization phase dated at 1255+-12 Ma. A series of tectonic events and accompanying hydrothermal mobilization and alteration resulted in modifications of the original monomineralic uranium orebody. Based on ore microscopic examinations and field observations in the Gaertner open pit, the following modification stages are identified: 1. ∼900 Ma: Fracturing of radially textured anisotropic uraninite, the oldest recognised uranium ore, subsequent introduction of Ni, As, S, Fe, Co and Cu. Radiometric dating of associated coffinite indicates an age of approximately 900 Ma. 2. ∼300 Ma: Renewed fracturing of the nickeliferous uranium ore stockwork, hydrothermal carbonate and clay alteration with dispersion of mobilized elements into the wall rocks, and multiple redistribution/introduction of U under varying physico-chemical conditions. On the basis of isotropy and optical reflectivity, four uraninite/pitchblende generations are distinguished in addition to a second nickel mineral suite and a coffinite phase. 3. <300 Ma: Vertical offset within the deposit under shallow conditions. Hydrothermal activity is not apparent. (author). 13 refs, 10 figs

  8. Hydrogeochemistry and uranium fixation in the Cigar Lake uranium deposit, northern Saskatchewan

    International Nuclear Information System (INIS)

    The 1.3 billion year old Cigar Lake uranium deposit, discovered by COGEMA in 1981, is a very rich and large mineralization of uraninite-pitchblende and coffinite in the Athabasca Sandstone in northern Saskatchewan. The mineralization occurs at the -450 m deep unconformity contact of the sandstone with the underlying high-grade rocks of the basement. The sandstone, particularly its basal unit, is the regional aquifer and, due to permeability caused by extensive fracturing, groundwater is found in all parts of the deposit. The composition of this groundwater has been studied in detail over the past 3 years. The compositions of the groundwaters from different parts of the deposit reveal a reduced, redox-buffered, steady-state system of water interaction with the ore and host rock. All groundwaters, including those in contact with the mineralization, are dilute, neutral pH waters containing low concentrations of dissolved uranium (∼10-7.9 to 10-9 mol/L U). Concentrations of dissolved radium-226 and radon-222 are also low except in groundwaters sampled within the ore zone. The redox chemistry is controlled by a number of different processes, including inorganic and organic reactions, bacterial activity and radiolysis of water in the ore zone. The iron-redox couple is the main process controlling the redox conditions in the present dynamic system. The formation of iron colloids in the ore zone and the retention of these colloids in the bordering clay zone restrict the migration of naturally occurring radionuclides, such as uranium, thorium and radium, from the ore. Information from the redox, colloid and isotope chemistries is used to discuss the history of uranium fixation in this deposit. (author)

  9. Reclamation design for a fen wetland on a tailings sand deposit in northern Alberta

    Energy Technology Data Exchange (ETDEWEB)

    Wytrykush, C. [Syncrude Canada Ltd., Edmonton, AB (Canada); McKenna, G.T.; Papini, A.G.; Scordo, E.B. [BGC Engineering Inc., Vancouver, BC (Canada)

    2010-07-01

    This paper discussed the first attempt at designing and constructing a fen wetland and surrounding watershed on a soft tailings deposit in the Athabasca oil sands region. Among the main design components were upland hummocks, vegetated swales, a pond for water storage, a fen wetland, and 2 perched fens. For each component, reclamation prescriptions were developed using methods from Syncrude's regulatory approvals for upland forests, advice from technical experts on wetlands, and results from an analogous wetland research program. Prior to the reclamation, a long-term research program was started to appraise the response of wetland plants to different operation treatments, including placement depth, material type, compaction, and salinity. Operation techniques were developed to glean live in-situ peat material from the top layer of the boreal forest for use in wetland reclamation. Design topography and soil material types were taken into account in developing the prescriptions, which were used to test specific research hypotheses within the instrumented research watershed.

  10. S reactivity of an oil sands composite tailings deposit undergoing reclamation wetland construction.

    Science.gov (United States)

    Reid, Michelle L; Warren, Lesley A

    2016-01-15

    This study is the first to characterize the S stability of a composite tailings (CT) deposit undergoing pilot wetland reclamation in the Athabasca Oil Sands Region (AOSR, Alberta, Canada). As CT is sulfur, organic carbon and bacterially rich, the goal of this study was to characterize the in situ aqueous distribution of sulfur compounds across the wetland, sand cap and underlying CT zones of the deposit, in an effort to establish the potential for microbial sulfur cycling and generation of H2S, an explosive, corrosive and toxicity risk. Porewater samples from three depths spanning the different layers of the deposit, as well as wetland surface ponded water samples were collected for geochemical analyses (July and Sept 2013), and for microbial enrichments (both S reducing and S oxidizing bacteria) in June 2014. While porewater ΣH2S(aq) was detected at all depths across the three zones of the deposit, results identify that the sand cap layer required for construction, acts as a mixing zone generating the highest solution H2S concentrations (>500 uM or 18 mg/L) and H2S gas levels (over 100 and up to 180 ppm) observed. Porewater dissolved sulfate concentrations (0.14-6.97 mM) were orders of magnitude higher and did not correlate to the observed distribution of ΣH2S concentrations throughout the deposit. Unique to the sandcap, dissolved organic carbon positively correlated with the observed maxima of ΣH2S(aq) seen in this layer. The water management of the deposit is a critical factor in the observed S trends. Active dewatering of the CT resulted in migration of S rich water up into the sandcap, while downwelling labile organic carbon from the developing wetland acted in concert to stimulate microbial generation of the H2S in this structural layer to the highest levels observed. Functional enrichments identified that diverse S reducing and oxidizing microbial metabolisms are widespread throughout the deposit, indicating that these waste materials are

  11. S reactivity of an oil sands composite tailings deposit undergoing reclamation wetland construction.

    Science.gov (United States)

    Reid, Michelle L; Warren, Lesley A

    2016-01-15

    This study is the first to characterize the S stability of a composite tailings (CT) deposit undergoing pilot wetland reclamation in the Athabasca Oil Sands Region (AOSR, Alberta, Canada). As CT is sulfur, organic carbon and bacterially rich, the goal of this study was to characterize the in situ aqueous distribution of sulfur compounds across the wetland, sand cap and underlying CT zones of the deposit, in an effort to establish the potential for microbial sulfur cycling and generation of H2S, an explosive, corrosive and toxicity risk. Porewater samples from three depths spanning the different layers of the deposit, as well as wetland surface ponded water samples were collected for geochemical analyses (July and Sept 2013), and for microbial enrichments (both S reducing and S oxidizing bacteria) in June 2014. While porewater ΣH2S(aq) was detected at all depths across the three zones of the deposit, results identify that the sand cap layer required for construction, acts as a mixing zone generating the highest solution H2S concentrations (>500 uM or 18 mg/L) and H2S gas levels (over 100 and up to 180 ppm) observed. Porewater dissolved sulfate concentrations (0.14-6.97 mM) were orders of magnitude higher and did not correlate to the observed distribution of ΣH2S concentrations throughout the deposit. Unique to the sandcap, dissolved organic carbon positively correlated with the observed maxima of ΣH2S(aq) seen in this layer. The water management of the deposit is a critical factor in the observed S trends. Active dewatering of the CT resulted in migration of S rich water up into the sandcap, while downwelling labile organic carbon from the developing wetland acted in concert to stimulate microbial generation of the H2S in this structural layer to the highest levels observed. Functional enrichments identified that diverse S reducing and oxidizing microbial metabolisms are widespread throughout the deposit, indicating that these waste materials are

  12. Atmospheric Deposition Modeling Results

    Data.gov (United States)

    U.S. Environmental Protection Agency — This asset provides data on model results for dry and total deposition of sulfur, nitrogen and base cation species. Components include deposition velocities, dry...

  13. Electro-Deposition Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — The electro-deposition laboratory can electro-deposit various coatings onto small test samples and bench level prototypes. This facility provides the foundation for...

  14. Calcium Pyrophosphate Deposition (CPPD)

    Science.gov (United States)

    ... Patient / Caregiver Diseases & Conditions Calcium Pyrophosphate Deposition (CPPD) Calcium Pyrophosphate Deposition (CPPD) Fast Facts The risk of ... young people, too. Proper diagnosis depends on detecting calcium pyrophosphate crystals in the fluid of an affected ...

  15. Comparison of P-containing {gamma}-Al{sub 2}O{sub 3} supported Ni-Mo bimetallic carbide, nitride and sulfide catalysts for HDN and HDS of gas oils derived from Athabasca bitumen

    Energy Technology Data Exchange (ETDEWEB)

    Sundaramurthy, V.; Dalai, A.K. [Catalysis and Chemical Reaction Engineering Laboratories, Department of Chemical Engineering, University of Saskatchewan, Saskatoon, SK (Canada); Adjaye, J. [Syncrude Edmonton Research Centre, Edmonton, AB (Canada)

    2006-09-01

    Phosphorus containing {gamma}-Al{sub 2}O{sub 3} supported bimetallic Ni-Mo carbide, nitride and sulfide catalysts have been synthesized from an oxide precursor containing 12.73wt.% Mo, 2.54wt.% Ni and 2.38wt.% P and characterized by elemental analysis, pulsed CO chemisorption, surface area measurements, X-ray diffraction, temperature-programmed reduction and DRIFT spectroscopy of CO adsorption. DRIFT spectroscopy of adsorbed CO on activated catalysts showed that carbide and nitride catalysts have surface exposed sites of Mo{sup o+} (0Athabasca bitumen in the temperature range 340-370 and 375-400{sup o}C respectively at 8.8MPa. The gradual transformation of Ni-Mo carbide and nitride phases into Ni-Mo sulfide phases was observed during precoking period, and the formed Ni-Mo sulfide phases enhanced the HDN and HDS activities of carbide and nitride catalysts. The {gamma}-Al{sub 2}O{sub 3} supported Ni-Mo bimetallic sulfide catalyst was found to be more active for HDN and HDS of light gas oil and heavy gas oil than the corresponding carbide and nitride catalysts on the basis of unit weight. (author)

  16. A multiple lines of evidence approach for the ecological risk assessment of an accidental bitumen release from a steam assisted gravity drainage (SAGD) well in the Athabasca oil sands region.

    Science.gov (United States)

    Berger, Robert G; Aslund, Melissa Whitfield; Sanders, Greg; Charlebois, Michael; Knopper, Loren D; Bresee, Karl E

    2016-01-15

    To assess the ecological impacts of two independent accidental bitumen releases from two steam assisted gravity drainage (SAGD) wells in the Athabasca oil sands region, a multiple lines of evidence (LOE) approach was developed. Following the release in 2010, action was taken to minimize environmental impact, including the selective removal of the most highly impacted vegetation and the use of oil socks to minimize possible runoff. An ecological risk assessment (ERA) was then conducted based on reported concentrations of bitumen related contaminants in soil, vegetation, and water. Results of biological assessments conducted at the site were also included in the risk characterization. Overall, the conclusion of the ERA was that the likelihood of long-term adverse health effects to ecological receptors in the area was negligible. To provide evidence for this conclusion, a small mammal sampling plan targeting Southern red-back voles (Myodes gapperi) was carried out at two sites and two relevant reference areas. Voles were readily collected at all locations and no statistically significant differences in morphometric measurements (i.e., body mass, length, foot length, and adjusted liver weight) were found between animals collected from impact zones of varying levels of coverage. Additionally, no trends corresponding with bitumen coverage were observed with respect to metal body burden in voles for metals that were previously identified in the source bitumen. Hepatic ethoxyresorufin-O-deethylase (EROD) activity was statistically significantly elevated in voles collected from the high impact zones of sites compared to those collected from the reference areas, a finding that is indicative of continued exposure to contaminants. However, this increase in EROD was not correlated with any observable adverse population-wide biological outcomes. Therefore the biological sampling program supported the conclusion of the initial ERA and supported the hypothesis of no significant

  17. Acid Deposition Phenomena

    International Nuclear Information System (INIS)

    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 (SO2) and nitrogen oxides (NOx). When these two compounds react with water, oxygen, and sunlight in the atmosphere, the result is sulfuric (H2SO4) and nitric acids (HNO3), the primary agents of acid deposition which mainly produced from the combustion of fossil fuel and from petroleum refinery. Airborne chemicals can travel long distances from their sources and can therefore affect ecosystems over broad regional scales and in locations far from the sources of emissions. According to the concern of petroleum ministry with the environment and occupational health, in this paper we will discussed the acid deposition phenomena through the following: Types of acidic deposition and its components in the atmosphere Natural and man-made sources of compounds causing the acidic deposition. Chemical reactions causing the acidic deposition phenomenon in the atmosphere. Factors affecting level of acidic deposition in the atmosphere. Impact of acid deposition. Procedures for acidic deposition control in petroleum industry

  18. Airfoil deposition model

    Science.gov (United States)

    Kohl, F. J.

    1982-01-01

    The methodology to predict deposit evolution (deposition rate and subsequent flow of liquid deposits) as a function of fuel and air impurity content and relevant aerodynamic parameters for turbine airfoils is developed in this research. The spectrum of deposition conditions encountered in gas turbine operations includes the mechanisms of vapor deposition, small particle deposition with thermophoresis, and larger particle deposition with inertial effects. The focus is on using a simplified version of the comprehensive multicomponent vapor diffusion formalism to make deposition predictions for: (1) simple geometry collectors; and (2) gas turbine blade shapes, including both developing laminar and turbulent boundary layers. For the gas turbine blade the insights developed in previous programs are being combined with heat and mass transfer coefficient calculations using the STAN 5 boundary layer code to predict vapor deposition rates and corresponding liquid layer thicknesses on turbine blades. A computer program is being written which utilizes the local values of the calculated deposition rate and skin friction to calculate the increment in liquid condensate layer growth along a collector surface.

  19. Petrography, fluid inclusion analysis, and geochronology of the End uranium deposit, Kiggavik, Nunavut, Canada

    Science.gov (United States)

    Chi, Guoxiang; Haid, Taylor; Quirt, David; Fayek, Mostafa; Blamey, Nigel; Chu, Haixia

    2016-04-01

    The End deposit is one of several uranium deposits in the Kiggavik area near the Proterozoic Thelon Basin, which is geologically similar to the Athabasca Basin known for its unconformity-related uranium deposits. The mineralization occurs as uraninite and coffinite in quartz veins and wall rocks (psammopelitic gneisses) in the sub-Thelon basement and is associated with clay- and hematite-altered fault zones. Fluid inclusions were studied in quartz cementing unmineralized breccias formed before mineralization (Q2), quartz veins that were formed before mineralization but spatially associated with uranite (Q4), and calcite veins that were formed after mineralization. Four types of fluid inclusions were recognized, namely liquid-dominated biphase (liquid + vapor), vapor-dominated biphase (vapor + liquid), monophase (vapor-only), and triphase (liquid + vapor + halite) inclusions. The first three types were found in Q2, whereas all four types were found in Q4 and calcite. The coexistence of these different types of inclusions within individual fluid inclusion assemblages is interpreted to indicate fluid immiscibility and heterogeneous trapping. Based on microthermometry, the fluids associated with Q2 are characterized by low salinities (0.4 to 6.6 wt%) and moderate temperatures from 148 to 261 °C, and the fluids associated with calcite show high salinities (26.8 to 29.3 wt%) and relatively low temperatures from 146 to 205 °C, whereas the fluids associated with Q4 have a wide range of salinities from 0.7 to 38.8 wt% and temperatures from 80 to 332 °C. Microthermometric and cryogenic Raman spectroscopic studies indicate that the high-salinity fluids in Q4 and calcite belong to the H2O-NaCl-CaCl2 ± MgCl2 system, with some dominated by NaCl and others by CaCl2. The fluid inclusions in Q2 are interpreted to be unrelated to mineralization, whereas those in Q4 and calcite reflect the mineralizing fluids. The fluid inclusion data are consistent with a genetic link of

  20. Radiation-induced defects in clay minerals, markers of the mobility of the uranium in solution in the unconformity-type uranium deposits

    International Nuclear Information System (INIS)

    This study presents the works driven on three groups of clay minerals (kaolins, illite, sudoite (di-tri-octahedral chlorites)) characteristics of the alteration halos surrounding unconformity-type uranium deposits, in order to reveal uranium paleo-circulations in the intra-cratonic meso-Proterozoic basins (1,2 - 1,6 Ga). Thanks to Electron Paramagnetic Resonance Spectroscopy (EPR), we were able to highlight the persistence of structural defects in kaolin-group minerals contemporaneous of the basin diagenesis, and demonstrate the existence of relatively stable defects in illites and sudoites contemporaneous of the uranium deposits setting. Thus, the main defect in illite (Ai centre) and the main defect in sudoite (As centre) are characterized by their g components such as, respectively, gt = 2,003 et g// = 2,051 for illite and gt = 2,008 et g// = 2,051 for sudoite. As the main defect in kaolins (kaolinite/dickite), the main defects in illite and sudoite are perpendicularly oriented according to the (ab) plane, on the tetrahedral Si-O bound. However, their thermal stabilities seem different. The observation of samples from different zones (background, anomal or mineralized) of the Athabasca basin (Canada) allowed to identify a parallel evolution between actual defects concentration measured in the different clay minerals and the proximity of the mineralisation zones. Consequently, clays minerals can be considered as potential plotters of zones where uranium-rich solutions have circulated. (author)

  1. Deposition patterns with Turbuhaler.

    Science.gov (United States)

    Borgström, L

    1994-01-01

    The degree of lung deposition is an important factor in the evaluation of different inhalation flow driven dry powder inhalers. A number of studies using radioactive and non-radioactive methods have been performed with Turbuhaler to assess lung deposition under different conditions. Mean total lung deposition of terbutaline sulfate or budesonide via Turbuhaler in healthy volunteers ranged from 21-32% of the dose when a normal inhalation flow (60L/min) was used. At a low flow (30L/min) a mean 15% of the dose was deposited in the lungs, a similar value as for a well-performed inhalation via a pressurized metered dose inhaler. Regional deposition of inhaled drug can be expressed as the ratio between the amount of drug deposited in the more peripheral parts of the lung relative to the more central parts. In a comparative study, budesonide and terbutaline sulfate were given by inhalation via Turbuhaler to healthy volunteers. The ratio of peripheral to central deposition was 2.03 for terbutaline and 1.72 for budesonide. Thus, both the water-soluble terbutaline sulfate and the non-water soluble budesonide seemed to behave in the same way when inhaled via Turbuhaler. In conclusion, Turbuhaler delivers over 20% of a metered dose to the lungs when inhaled at a normal inhalation flow rate. The regional deposition pattern in the lungs was the same for terbutaline sulfate and budesonide, in spite of differences in water solubility. PMID:10147081

  2. MAPLE deposition of nanomaterials

    Energy Technology Data Exchange (ETDEWEB)

    Caricato, A.P., E-mail: annapaola.caricato@le.infn.it [Department of Mathematics and Physics “E. De Giorgi”, University of Salento, Via Arnesano, I-73100 Lecce (Italy); Arima, V.; Catalano, M. [National Nanotechnology Laboratory (NNL), CNR Istituto Nanoscienze, c/o Distretto Tecnologico, Via Arnesano n. 16, I-73100 Lecce (Italy); Cesaria, M. [Department of Mathematics and Physics “E. De Giorgi”, University of Salento, Via Arnesano, I-73100 Lecce (Italy); Cozzoli, P.D. [Department of Mathematics and Physics “E. De Giorgi”, University of Salento, Via Arnesano, I-73100 Lecce (Italy); National Nanotechnology Laboratory (NNL), CNR Istituto Nanoscienze, c/o Distretto Tecnologico, Via Arnesano n. 16, I-73100 Lecce (Italy); Martino, M. [Department of Mathematics and Physics “E. De Giorgi”, University of Salento, Via Arnesano, I-73100 Lecce (Italy); Taurino, A.; Rella, R. [Institute for Microelectronics and Microsystems, IMM-CNR, Via Monteroni, I-73100 Lecce (Italy); Scarfiello, R. [National Nanotechnology Laboratory (NNL), CNR Istituto Nanoscienze, c/o Distretto Tecnologico, Via Arnesano n. 16, I-73100 Lecce (Italy); Tunno, T. [Department of Mathematics and Physics “E. De Giorgi”, University of Salento, Via Arnesano, I-73100 Lecce (Italy); Zacheo, A. [Department of Mathematics and Physics “E. De Giorgi”, University of Salento, Via Arnesano, I-73100 Lecce (Italy); National Nanotechnology Laboratory (NNL), CNR Istituto Nanoscienze, c/o Distretto Tecnologico, Via Arnesano n. 16, I-73100 Lecce (Italy)

    2014-05-01

    The matrix-assisted pulsed laser evaporation (MAPLE) has been recently exploited for depositing films of nanomaterials by combining the advantages of colloidal inorganic nanoparticles and laser-based techniques. MAPLE-deposition of nanomaterials meeting applicative purposes demands their peculiar properties to be taken into account while planning depositions to guarantee a congruent transfer (in terms of crystal structure and geometric features) and explain the deposition outcome. In particular, since nanofluids can enhance thermal conductivity with respect to conventional fluids, laser-induced heating can induce different ablation thermal regimes as compared to the MAPLE-treatment of soft materials. Moreover, nanoparticles exhibit lower melting temperatures and can experience pre-melting phenomena as compared to their bulk counterparts, which could easily induce shape and or crystal phase modification of the material to be deposited even at very low fluences. In this complex scenario, this review paper focuses on examples of MAPLE-depositions of size and shape controlled nanoparticles for different applications highlights advantages and challenges of the MAPLE-technique. The influence of the deposition parameters on the physical mechanisms which govern the deposition process is discussed.

  3. Preliminary fingerprinting of Athabasca oil sands polar organics in environmental samples using electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry.

    Science.gov (United States)

    Headley, J V; Barrow, M P; Peru, K M; Fahlman, B; Frank, R A; Bickerton, G; McMaster, M E; Parrott, J; Hewitt, L M

    2011-07-15

    There is a growing need to develop analytical methods that can distinguish compounds found within industrially derived oil sands process water (OSPW) from those derived from natural weathering of oil sands deposits. This is a difficult challenge as possible leakage beyond tailings pond containments will probably be in the form of mixtures of water-soluble organics that may be similar to those leaching naturally into aquatic environments. We have evaluated the potential of negative ion electrospray ionization high-resolution Fourier transform ion cyclotron resonance mass spectrometry (FTICRMS) for comparing oil sands polar organics from tailing ponds, interceptor wells, groundwater, river and lake surface waters. Principal component analysis was performed for all species observed. which included the O(2) class (often assumed to be monocarbxoylic naphthenic acids) along with a wide range of other species including humic substances in the river and lake samples: O(n) where n=1-16; NO(n) and N(2)O(n) where n=1-13; and O(n)S and O(n)S(2) where n=1-10 and 1-8, respectively. A broad range of species was investigated because classical naphthenic acids can be a small fraction of the 'organics' detected in the polar fraction of OSPW, river water and groundwater. Aquatic toxicity and environmental chemistry are attributed to the total organics (not only the classical naphthenic acids). The distributions of the oil sands polar organics, particularly the sulfur-containing species, O(n)S and O(n)S(2), may have potential for distinguishing sources of OSPW. The ratios of species containing O(n) along with nitrogen-containing species: NO(n), and N(2)O(n), were useful for differentiating organic components derived from OSPW from those found in river and lake waters. Further application of the FTICRMS technique for a diverse range of OSPW of varying ages and composition, as well as the surrounding groundwater wells, may be critical in assessing whether leakage from industrial sources

  4. Biomimetic thin film deposition

    Energy Technology Data Exchange (ETDEWEB)

    Rieke, P.R.; Graff, G.E.; Campbell, A.A.; Bunker, B.C.; Baskaran, S.; Song, L.; Tarasevich, B.J.; Fryxell, G.E.

    1995-09-01

    Biological mineral deposition for the formation of bone, mollusk shell and other hard tissues provides materials scientists with illustrative materials processing strategies. This presentation will review the key features of biomineralization and how these features can be of technical importance. We have adapted existing knowledge of biomineralization to develop a unique method of depositing inorganic thin films and coating. Our approach to thin film deposition is to modify substrate surfaces to imitate the proteins found in nature that are responsible for controlling mineral deposition. These biomimetic surfaces control the nucleation and growth of the mineral from a supersaturated aqueous solution. This has many processing advantages including simple processing equipment, environmentally benign reagents, uniform coating of highly complex shapes, and enhanced adherence of coating. Many different types of metal oxide, hydroxide, sulfide and phosphate materials with useful mechanical, optical, electronic and biomedical properties can be deposited.

  5. Automatic Payroll Deposit System.

    Science.gov (United States)

    Davidson, D. B.

    1979-01-01

    The Automatic Payroll Deposit System in Yakima, Washington's Public School District No. 7, directly transmits each employee's salary amount for each pay period to a bank or other financial institution. (Author/MLF)

  6. Modeled Wet Nitrate Deposition

    Data.gov (United States)

    U.S. Environmental Protection Agency — Modeled data on nitrate wet deposition was obtained from Dr. Jeff Grimm at Penn State Univ. Nitrate wet depostion causes acidification and eutrophication of surface...

  7. Podiform chromite deposits

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Location and characteristics of 1,124 individual mineral deposits of this type, with grade and tonnage models for chromium as well as several related elements.

  8. Uranium deposit research, 1983

    International Nuclear Information System (INIS)

    Research on uranium deposits in Canada, conducted as a prerequisite for assessment of the Estimated Additional Resources of uranium, revealed that (a) the uranium-gold association in rudites of the Huronian Supergroup preferably occurs in the carbon layers; (b) chloritized ore at the Panel mine, Elliot Lake, Ontario, occurs locally in tectonically disturbed areas in the vicinity of diabase dykes; (c) mineralization in the Black Sturgeon Lake area, Ontario, formed from solutions in structural and lithological traps; (d) the Cigar Lake deposit, Saskatchewan, has two phases of mineralization: monomineralic and polymetallic; (e) mineralization of the JEB (Canoxy Ltd.) deposit is similar to that at McClean Lake; (f) the uranium-carbon assemblage was identified in the Claude deposit, Carswell Structure; and (g) the Otish Mountains area, Quebec, should be considered as a significant uranium-polymetallic metallogenic province

  9. Alluvial Deposits in Iowa

    Data.gov (United States)

    Iowa State University GIS Support and Research Facility — This coverage maps alluvial deposits throughout Iowa. This generally would include areas of alluvial soils associated with modern streams that are identified on...

  10. Speleothem (Cave Deposit) Data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Records of past temperature, precipitation, and other aspects of climate derived from mineral deposits found in caves. Parameter keywords describe what was measured...

  11. Gemstone deposits of Serbia

    Directory of Open Access Journals (Sweden)

    Miladinović Zoran

    2016-06-01

    Full Text Available Gemstone minerals in Serbia have never been regarded as an interesting and significant resource. Nevertheless, more than 150 deposits and occurrences have been recorded and some of them preliminarily explored in the last 50 years. The majority of deposits and occurrences are located within the Serbo-Macedonian metallogenic province and the most significant metallogenic units at the existing level of knowledge are the Fruska Gora ore district, Cer ore district, Sumadija metallogenic zone, Kopaonik metallogenic zone and Lece-Halkidiki metallogenic zone. The most important genetic type of deposits is hydrothermal, particularly in case of serpentinite/peridotite as host/parent rock. Placer deposits are also economically important. The dominant gemstones are silica minerals: chalcedony (Chrysoprase, carnelian, bluish chalcedony etc., jasper (picture, landscape, red etc., common opal (dendritic, green, milky white etc., silica masses (undivided, and quartz (rock crystal, amethyst etc.. Beside silica minerals significant gemstones in Serbia include also beryl (aquamarine, garnet (almandine and pyrope, tourmaline, fluorite, rhodochrosite, carbonate-silica breccia, carbonate-silica onyx, silicified wood, howlite, serpentinite, marble onyx, and kyanite. This paper aims to present an overview of Serbian gemstone deposits and occurrences and their position based on a simplified gemstone metallogenic map of Serbia, as well as genetic-industrial classification of gemstone deposits and gemstone varieties.

  12. Uranium deposits in Africa

    International Nuclear Information System (INIS)

    Africa is not only known for its spectacular diamond, gold, copper, chromium, platinum and phosphorus deposits but also for its uranium deposits. At least two uranium provinces can be distinguished - the southern, with the equatorial sub-province; and the south Saharan province. Uranium deposits are distributed either in cratons or in mobile belts, the first of sandstone and quartz-pebble conglomerate type, while those located in mobile belts are predominantly of vein and similar (disseminated) type. Uranium deposits occur within Precambrian rocks or in younger platform sediments, but close to the exposed Precambrian basement. The Proterozoic host rocks consist of sediments, metamorphics or granitoids. In contrast to Phanerozoic continental uranium-bearing sediments, those in the Precambrian are in marginal marine facies but they do contain organic material. The geology of Africa is briefly reviewed with the emphasis on those features which might control the distribution of uranium. The evolution of the African Platform is considered as a progressive reduction of its craton area which has been affected by three major Precambrian tectonic events. A short survey on the geology of known uranium deposits is made. However, some deposits and occurrences for which little published material is available are treated in more detail. (author)

  13. Pulsed laser deposition: Prospects for commercial deposition of epitaxial films

    Energy Technology Data Exchange (ETDEWEB)

    Muenchausen, R.E.

    1999-03-01

    Pulsed laser deposition (PLD) is a physical vapor deposition (PVD) technique for the deposition of thin films. The vapor source is induced by the flash evaporation that occurs when a laser pulse of sufficient intensity (about 100 MW/cm{sup 2}) is absorbed by a target. In this paper the author briefly defines pulsed laser deposition, current applications, research directed at gaining a better understanding of the pulsed laser deposition process, and suggests some future directions to enable commercial applications.

  14. Vein type uranium deposits

    International Nuclear Information System (INIS)

    Veins are tabular- or sheet-like masses of minerals occupying or following a fracture or a set of fractures in the enclosing rock. They have been formed later than the country rock and fractures, either by filling of the open spaces or by partial or complete replacement of the adjoining rock or most commonly by both of these processes combined. This volume begins with the occurrences and deposits known from old shield areas and the sedimentary belts surrounding them. They are followed by papers describing the European deposits mostly of Variscan age, and by similar deposits known from China being of Jurassic age. The volume is completed by two papers which do not fit exactly in the given scheme. A separate abstract was prepared for each of the 25 papers in this report

  15. Shedding of ash deposits

    DEFF Research Database (Denmark)

    Zbogar, Ana; Frandsen, Flemming; Jensen, Peter Arendt;

    2009-01-01

    Ash deposits formed during fuel thermal conversion and located on furnace walls and on convective pass tubes, may seriously inhibit the transfer of heat to the working fluid and hence reduce the overall process efficiency. Combustion of biomass causes formation of large quantities of troublesome....... Low melting temperatures make straw ashes especially troublesome, since their stickiness is higher at lower temperatures, compared to coal ashes. Increased stickiness will eventually lead to a higher collection efficiency of incoming ash particles, meaning that the deposit may grow even faster...

  16. An EPR study of native radiation-induced paramagnetic defects in sudoite (di-trioctahedral Al-Mg chlorite) from the alteration halo related to unconformity-type uranium deposits

    Science.gov (United States)

    Morichon, Élisa; Allard, Thierry; Beaufort, Daniel; Quirt, David

    2010-03-01

    Natural radiation-induced defects were identified in specimens of sudoite (Al-Mg di-trioctahedral chlorite) related to unconformity-type uranium deposits at the base of the Athabasca Group (Saskatchewan, Canada), using electron paramagnetic resonance (EPR) spectroscopy at X- and Q-band frequencies. X-band spectra indicate the presence of a main native defect, named the As-center, whose EPR signal is dominated by an axially distorted spectrum with apparent principal components as follows: g // = 2,051 and g ⊥ = 2,005, and a secondary defect with apparent component g = 2,025. The study of oriented specimens shows that the main defect has its g // component perpendicular to the ( ab) plane of sudoite. The As-center corresponds to an electron hole located on oxygen atoms of the structure and is likely associated with Si, according to the lack of hyperfine structure. The As-center in sudoite has EPR parameters similar to the A-center in kaolinite and dickite, and the Ai-center in illite. The saturation behavior of EPR spectra as a function of power demonstrates that native defects of sudoite are different from those known in other clays, such as kaolinite, dickite or smectite, but are similar to those of illite. The isochronal annealing data suggest that the main defect in sudoite is stable to more than 300°C. The corresponding defects characterized in sudoite may have the potential for tracing past radionuclide migration around unconformity-type uranium deposits.

  17. Paleolimnological assessment of riverine and atmospheric pathways and sources of metal deposition at a floodplain lake (Slave River Delta, Northwest Territories, Canada).

    Science.gov (United States)

    MacDonald, Lauren A; Wiklund, Johan A; Elmes, Matthew C; Wolfe, Brent B; Hall, Roland I

    2016-02-15

    Growth of natural resource development in northern Canada has raised concerns about the effects on downstream aquatic ecosystems, but insufficient knowledge of pre-industrial baseline conditions continues to undermine ability of monitoring programs to distinguish industrial-derived contaminants from those supplied by natural processes. Here, we apply a novel paleolimnological approach to define pre-industrial baseline concentrations of 13 priority pollutant metals and vanadium and assess temporal changes, pathways and sources of these metals at a flood-prone lake (SD2) in the Slave River Delta (NWT, Canada) located ~500 km north of Alberta's oil sands development and ~140 km south of a former gold mine at Yellowknife, NWT. Results identify that metal concentrations, normalized to lithium concentration, are not elevated in sediments deposited during intervals of high flood influence or low flood influence since onset of oil sands development (post-1967) relative to the 1920-1967 baseline established at SD2. When compared to a previously defined baseline for the upstream Athabasca River, several metal-Li relations (Cd, Cr, Ni, Zn, V) in post-1967 sediments delivered by floodwaters appear to plot along a different trajectory, suggesting that the Peace and Slave River watersheds are important natural sources of metal deposition at the Slave River Delta. However, analysis revealed unusually high concentrations of As deposited during the 1950s, an interval of very low flood influence at SD2, which corresponded closely with emission history of the Giant Mine gold smelter indicating a legacy of far-field atmospheric pollution. Our study demonstrates the potential for paleolimnological characterization of baseline conditions and detection of pollution from multiple pathways in floodplain ecosystems, but that knowledge of paleohydrological conditions is essential for interpretation of contaminant profiles. PMID:26688053

  18. "Total Deposition (TDEP) Maps"

    Science.gov (United States)

    The presentation provides an update on the use of a hybrid methodology that relies on measured values from national monitoring networks and modeled values from CMAQ to produce of maps of total deposition for use in critical loads and other ecological assessments. Additionally, c...

  19. Thorium ore deposits

    International Nuclear Information System (INIS)

    The main occurences of the thorium minerals of the Argentine Republic which have not been exploited, due to their reduced volume, are described. The thoriferous deposits have three genetic types: pegmatitic, hydrothermal and detritic, being the most common minerals: monazite, thorite and thorogummite. The most important thorium accumulations are located in Salta, being of less importance those of Cordoba, Jujuy and San Juan. (M.E.L.)

  20. The classification of minerals deposits

    International Nuclear Information System (INIS)

    In this part of book author present the classification of minerals deposits. Deposit formation take place as a result of complicated and long geology processes in the wide temperature intervals (from 1500 digC to usual) and pressures (from usual and to tens kilobars). Deposits of minerals as other investigation objects require in definite systematization on the base of definite characteristics

  1. Limited Deposit Insurance Coverage and Bank Competition

    OpenAIRE

    Shy, Oz; Stenbacka, Rune; Yankov, Vladimir

    2014-01-01

    Deposit insurance designs in many countries place a limit on the coverage of deposits in each bank. However, no limits are placed on the number of accounts held with different banks. Therefore, under limited deposit insurance, some consumers open accounts with different banks to achieve higher or full deposit insurance coverage. We compare three regimes of deposit insurance: No deposit insurance, unlimited deposit insurance, and limited deposit insurance. We show that limited deposit insuranc...

  2. FDIC Summary of Deposits (SOD) Download File

    Data.gov (United States)

    Federal Deposit Insurance Corporation — The FDIC's Summary of Deposits (SOD) download file contains deposit data for branches and offices of all FDIC-insured institutions. The Federal Deposit Insurance...

  3. Some characteristics of electrospark deposition

    Energy Technology Data Exchange (ETDEWEB)

    Lesnjak, A. [Q-Techna, Krsko (Sierra Leone); Tusek, J. [Faculty of Mechanical Engineering, Ljubljana (Sierra Leone)

    2003-11-01

    The paper deals with some characteristics of electrospark deposition. A relevant device and the process are described, the material transfer is shown schematically, and the average droplet mass, the thickness of deposited layer, and the layer roughness are determined. Two types of substrate (tool steel, austenitic stainless steel), two types of shielding gas, (Ar, He), and three types of filler material, (WC, TiC, Stellite 6) were used. With some deposit, chemical analyses of deposit surfaces were performed and with some others through-thickness chemical analyses. Among the final conclusions the most important one is that the addition of a shielding gas results in a considerable increase in deposit quality. The device manufacturer, however, recommends deposition without the addition of a shielding gas. (orig.)

  4. Momentum Deposition in Curvilinear Coordinates

    Energy Technology Data Exchange (ETDEWEB)

    Cleveland, Mathew Allen [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Lowrie, Robert Byron [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Rockefeller, Gabriel M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Thompson, Kelly Glen [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Wollaber, Allan Benton [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-08-03

    The momentum imparted into a material by thermal radiation deposition is an important physical process in astrophysics and inertial confinement fusion (ICF) simulations. In recent work we presented a new method of evaluating momentum deposition that relies on the combination of a time-averaged approximation and a numerical integration scheme. This approach robustly and efficiently evaluates the momentum deposition in spherical geometry. Future work will look to extend this approach to 2D cylindrical geometries.

  5. Electrophoretic Deposition of Hydroxyapatite Coating

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Hydroxyapatite (HAP) coatings were deposited onto titanium substrates by electrophoretic deposition (EPD) fromethanol. The results indicated that the addition of very small amount of HCI resulted in a decrease in the aging timeas well as the suspension concentration required to obtain a coating. In addition, the results revealed the existenceof a critical saturated voltage (Vsat), which had significant effect on the quality of deposition. The mean interfacialshear strengths of HAP coatings after sintering were found to be greater than 13 MPa.

  6. Combined Tree-Ring Carbon and Nitrogen Isotopes to infer past atmospheric deposition in Northeastern Alberta

    Science.gov (United States)

    Savard, M. M.; Bégin, C.; Marion, J.

    2013-12-01

    Monitoring atmospheric emissions from industrial centers in North America is significantly younger than the emitting activities themselves. Attention should be placed on SOx and NOx emissions as they have been increasing over the last 15 years in western Canada. In Northeastern Alberta in particular, two distinct diffuse pollution contexts deserve attention: the Lower Athabasca Oil Sands (OS) district (north of Fort McMurray), and the coal fired power plant (CFPP) area (west of Edmonton). The NOx and SO2 emissions started in 1967 and 1956, but the direct air quality monitoring has been initiated in 1997 and 1985, in these respective contexts. In an attempt to address the gap in emission and deposition monitoring, we explored the δ13C and δ15N patterns of spruce trees (Picea glauca and Picea mariana) growing in four stands in the OS district and one stand, in the CFPP area. Tree-ring series collected from these five sites all covering the 1880-2010 period were analyzed and their δ13C and δ15N values examined along with the climatic parameters and SOx and NOx emission proxies. For two stands in the OS district where soil drainage was poor δ15N series did not vary significantly, but the intermediate and long-term δ13C and δ15N trends inversely correlate in the three other studied stands. For these three sites statistical analyses for the pre-operation calibration periods (1910-1961 and 1900-1951) allowed developing transfer functions and predicting the natural δ13C and δ15N responses to climatic conditions for the operation periods. The measured series all depart from the modeled natural trends, depicting anomalies. Interestingly, the anomalies in the two regions can be nicely reproduced by multiple-regression models combining local climatic parameters with acidifying emissions. Notwithstanding the significant inverse correlations between the δ13C and δ15N series for the three well drained sites and their link to acidifying emissions, it is too early to

  7. Multiphase flow wax deposition modelling

    Energy Technology Data Exchange (ETDEWEB)

    Matzain, A. [Petronas Research and Scientific Services, Kuala Lumpur (Malaysia); Zhang, H.-Q.; Volk, M.; Redus, C.L.; Brill, J.P. [University of Tulsa (United States); Apte, M.S. [Shell Technology EP (United States); Creek, J.L. [Chevron Petroleum Technology (United States)

    2000-07-01

    Results are presented from two-phase flow wax deposition tests using a state-of-the-art, high pressure, multiphase flow test facility. Wax deposition was found to be flow pattern dependent and occurs only along the pipe wall in contact with the waxy crude oil. The deposition buildup trend at low mixture velocities is similar to that observed in laminar single-phase flow tests. The buildup trend at high mixture velocities is similar to that observed in turbulent single-phase flow tests. Thinner and harder deposits at the bottom than at the top of the pipe were observed in horizontal intermittent flow tests. Thicker and harder deposits were observed at low liquid superficial velocity than at high liquid superficial velocity annular flow tests. No wax deposition was observed along the upper portion of the pipe in stratified flow tests. A semi-empirical kinetic model tailored for the wax deposition tests predicted wax thickness with an acceptable accuracy, especially at high oil superficial velocity. Deposition rate reduction due to shear stripping and rate enhancement due to entrapment of oil and other mechanisms not accounted for by the classical Fick's mass diffusion theory were incorporated through the use of dimensionless variables and empirical constants derived from the wax deposition data. The kinetic model, although semi-empirical, provides an insight for future model development. (author)

  8. 78 FR 56583 - Deposit Insurance Regulations; Definition of Insured Deposit

    Science.gov (United States)

    2013-09-13

    ... U.S. bank under deposit agreements governed by non-U.S. law to take advantage of a large bank's... 330 Bank deposit insurance, Banks, Banking, Reporting and recordkeeping requirements, Savings and Loan... of U.S. insured depository institutions (``IDI'' or ``U.S. bank''). The Final Rule clarifies...

  9. Enhanced nitrogen deposition over China

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Xuejun; Zhang, Ying; Han, Wenxuan; Tang, Aohan; Shen, Jianlin; Cui, Zhenling; Christie, Peter; Zhang, Fusuo [College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193 (China); Vitousek, Peter [Department of Biology, Stanford University, Stanford, California 94305 (United States); Erisman, Jan Willem [VU University Amsterdam, 1081 HV Amsterdam (Netherlands); Goulding, Keith [The Sustainable Soils and Grassland Systems Department, Rothamsted Research, Harpenden AL5 2JQ (United Kingdom); Fangmeier, Andreas [Institute of Landscape and Plant Ecology, University of Hohenheim, 70593 Stuttgart (Germany)

    2013-02-28

    China is experiencing intense air pollution caused in large part by anthropogenic emissions of reactive nitrogen. These emissions result in the deposition of atmospheric nitrogen (N) in terrestrial and aquatic ecosystems, with implications for human and ecosystem health, greenhouse gas balances and biological diversity. However, information on the magnitude and environmental impact of N deposition in China is limited. Here we use nationwide data sets on bulk N deposition, plant foliar N and crop N uptake (from long-term unfertilized soils) to evaluate N deposition dynamics and their effect on ecosystems across China between 1980 and 2010. We find that the average annual bulk deposition of N increased by approximately 8 kilograms of nitrogen per hectare (P < 0.001) between the 1980s (13.2 kilograms of nitrogen per hectare) and the 2000s (21.1 kilograms of nitrogen per hectare). Nitrogen deposition rates in the industrialized and agriculturally intensified regions of China are as high as the peak levels of deposition in northwestern Europe in the 1980s, before the introduction of mitigation measures. Nitrogen from ammonium (NH4+) is the dominant form of N in bulk deposition, but the rate of increase is largest for deposition of N from nitrate (NO3-), in agreement with decreased ratios of NH3 to NOx emissions since 1980. We also find that the impact of N deposition on Chinese ecosystems includes significantly increased plant foliar N concentrations in natural and semi-natural (that is, non-agricultural) ecosystems and increased crop N uptake from long-term-unfertilized croplands. China and other economies are facing a continuing challenge to reduce emissions of reactive nitrogen, N deposition and their negative effects on human health and the environment.

  10. Deposition and Resuspension of Particles

    DEFF Research Database (Denmark)

    Lengweiler, P.; Nielsen, Peter V.; Moser, A.;

    A new experimental set-up to investigate the physical process of dust deposition and resuspension on and from surfaces is introduced. Dust deposition can reduce the airBorne dust concentration considerably. As a basis for developing methods to eliminate dust related problems in rooms, there is a...

  11. Sandstone-type uranium deposits

    International Nuclear Information System (INIS)

    World-class sandstone-type uranium deposits are defined as epigenetic concentrations of uranium minerals occurring as uneven impregnations and minor massive replacements primarily in fluvial, lacustrine, and deltaic sandstone formations. The main purpose of this introductory paper is to define, classify, and introduce to the general geologic setting for sandstone-type uranium deposits

  12. Liquefier Dynamics in Fused Deposition

    DEFF Research Database (Denmark)

    Bellini, Anna; Guceri, Selcuk; Bertoldi, Maurizio

    2004-01-01

    Layered manufacturing (LM) is an evolution of rapid prototyping (RP) technology whereby a part is built in layers. Fused deposition modeling (FDM) is a particular LM technique in which each section is fabricated through vector style deposition of building blocks, called roads, which...

  13. Variable temperature semiconductor film deposition

    Science.gov (United States)

    Li, Xiaonan; Sheldon, Peter

    1998-01-01

    A method of depositing a semiconductor material on a substrate. The method sequentially comprises (a) providing the semiconductor material in a depositable state such as a vapor for deposition on the substrate; (b) depositing the semiconductor material on the substrate while heating the substrate to a first temperature sufficient to cause the semiconductor material to form a first film layer having a first grain size; (c) continually depositing the semiconductor material on the substrate while cooling the substrate to a second temperature sufficient to cause the semiconductor material to form a second film layer deposited on the first film layer and having a second grain size smaller than the first grain size; and (d) raising the substrate temperature, while either continuing or not continuing to deposit semiconductor material to form a third film layer, to thereby anneal the film layers into a single layer having favorable efficiency characteristics in photovoltaic applications. A preferred semiconductor material is cadmium telluride deposited on a glass/tin oxide substrate already having thereon a film layer of cadmium sulfide.

  14. Ni-Co laterite deposits

    Science.gov (United States)

    Marsh, Erin E.; Anderson, Eric D.

    2011-01-01

    Nickel-cobalt (Ni-Co) laterite deposits are an important source of nickel (Ni). Currently, there is a decline in magmatic Ni-bearing sulfide lode deposit resources. New efforts to develop an alternative source of Ni, particularly with improved metallurgy processes, make the Ni-Co laterites an important exploration target in anticipation of the future demand for Ni. This deposit model provides a general description of the geology and mineralogy of Ni-Co laterite deposits, and contains discussion of the influences of climate, geomorphology (relief), drainage, tectonism, structure, and protolith on the development of favorable weathering profiles. This model of Ni-Co laterite deposits represents part of the U.S. Geological Survey Mineral Resources Program's effort to update the existing models to be used for an upcoming national mineral resource assessment.

  15. Enhanced nitrogen deposition over China.

    Science.gov (United States)

    Liu, Xuejun; Zhang, Ying; Han, Wenxuan; Tang, Aohan; Shen, Jianlin; Cui, Zhenling; Vitousek, Peter; Erisman, Jan Willem; Goulding, Keith; Christie, Peter; Fangmeier, Andreas; Zhang, Fusuo

    2013-02-28

    China is experiencing intense air pollution caused in large part by anthropogenic emissions of reactive nitrogen. These emissions result in the deposition of atmospheric nitrogen (N) in terrestrial and aquatic ecosystems, with implications for human and ecosystem health, greenhouse gas balances and biological diversity. However, information on the magnitude and environmental impact of N deposition in China is limited. Here we use nationwide data sets on bulk N deposition, plant foliar N and crop N uptake (from long-term unfertilized soils) to evaluate N deposition dynamics and their effect on ecosystems across China between 1980 and 2010. We find that the average annual bulk deposition of N increased by approximately 8 kilograms of nitrogen per hectare (P effects on human health and the environment.

  16. Glacial atmospheric phosphorus deposition

    Science.gov (United States)

    Kjær, Helle Astrid; Dallmayr, Remi; Gabrieli, Jacopo; Goto-Azuma, Kumiko; Hirabayashi, Motohiro; Svensson, Anders; Vallelonga, Paul

    2016-04-01

    Phosphorus in the atmosphere is poorly studied and thus not much is known about atmospheric phosphorus and phosphate transport and deposition changes over time, though it is well known that phosphorus can be a source of long-range nutrient transport, e.g. Saharan dust transported to the tropical forests of Brazil. In glacial times it has been speculated that transport of phosphorus from exposed shelves would increase the ocean productivity by wash out. However whether the exposed shelf would also increase the atmospheric load to more remote places has not been investigated. Polar ice cores offer a unique opportunity to study the atmospheric transport of aerosols on various timescales, from glacial-interglacial periods to recent anthropogenic influences. We have for the first time determined the atmospheric transport of phosphorus to the Arctic by means of ice core analysis. Both total and dissolved reactive phosphorus were measured to investigate current and past atmospheric transport of phosphorus to the Arctic. Results show that glacial cold stadials had increased atmospheric total phosphorus mass loads of 70 times higher than in the past century, while DRP was only increased by a factor of 14. In the recent period we find evidence of a phosphorus increase over the past 50 yrs in ice cores close to human occupation likely correlated to forest fires. References: Kjær, Helle Astrid, et al. "Continuous flow analysis method for determination of dissolved reactive phosphorus in ice cores." Environmental science & technology 47.21 (2013): 12325-12332. Kjær, Helle Astrid, et al. "Greenland ice cores constrain glacial atmospheric fluxes of phosphorus." Journal of Geophysical Research: Atmospheres120.20 (2015).

  17. TULSA UNIVERSITY PARAFFIN DEPOSITION PROJECTS

    Energy Technology Data Exchange (ETDEWEB)

    Michael Volk; Cem Sarica

    2003-10-01

    As oil and gas production moves to deeper and colder water, subsea multiphase production systems become critical for economic feasibility. It will also become increasingly imperative to adequately identify the conditions for paraffin precipitation and predict paraffin deposition rates to optimize the design and operation of these multiphase production systems. Although several oil companies have paraffin deposition predictive capabilities for single-phase oil flow, these predictive capabilities are not suitable for the multiphase flow conditions encountered in most flowlines and wellbores. For deepwater applications in the Gulf of Mexico, it is likely that multiphase production streams consisting of crude oil, produced water and gas will be transported in a single multiphase pipeline to minimize capital cost and complexity at the mudline. Existing single-phase (crude oil) paraffin deposition predictive tools are clearly inadequate to accurately design these pipelines because they do not account for the second and third phases, namely, produced water and gas. The objective of this program is to utilize the current test facilities at The University of Tulsa, as well as member company expertise, to accomplish the following: enhance our understanding of paraffin deposition in single and two-phase (gas-oil) flows; conduct focused experiments to better understand various aspects of deposition physics; and, utilize knowledge gained from experimental modeling studies to enhance the computer programs developed in the previous JIP for predicting paraffin deposition in single and two-phase flow environments. These refined computer models will then be tested against field data from member company pipelines. The following deliverables are scheduled during the first three projects of the program: (1) Single-Phase Studies, with three different black oils, which will yield an enhanced computer code for predicting paraffin deposition in deepwater and surface pipelines. (2) Two

  18. Spatial distribution and compositional variation of APS minerals related to uranium deposits in the Kiggavik-Andrew Lake structural trend, Nunavut, Canada

    Science.gov (United States)

    Riegler, Thomas; Quirt, Dave; Beaufort, Daniel

    2016-02-01

    The Kiggavik-Andrew Lake structural trend consists of four mineralized zones, partially outcropping, lying 2 km south of the erosional contact with the unmetamorphosed sandstone and basal conglomerates of the Paleoproterozoic Thelon Formation. The mineralization is controlled by a major E-W fault system associated with illite and sudoite alteration halos developed in the Archean metagraywackes of the Woodburn Lake Group. Aluminum phosphate sulfate (APS) minerals from the alunite group crystallized in association with the clay minerals in the basement alteration halo as well as in the overlying sandstones, which underwent mostly diagenesis. APS minerals are Sr- and S-rich (svanbergite end-member) in the sedimentary cover overlying the unconformity, whereas they are light rare earth elements (LREE)-rich (florencite end-member) in the altered basement rocks below the unconformity. The geochemical signature of each group of APS minerals together with the petrography indicates three distinct generations of APS minerals related to the following: (1) paleoweathering of continental surfaces prior to the basin occurrence, (2) diagenetic processes during the burial history of the lower unit of the Thelon sandstones, and (3) hydrothermal alteration processes which accompanied the uranium deposition in the basement rocks and partially overlap the sedimentary-diagenetic mineral parageneses. In addition, the association of a first generation of APS minerals with both detrital cerium oxide and aluminum oxy-hydroxide highlights the fact that a part of the detrital material of the basal Thelon Formation originated from eroded paleolaterite (allochthonous regolith). The primary rare earth element (REE)-bearing minerals (e.g., monazite, REE carbonates, and allanite) of the host rocks were characterized to identify the potential sources of REE. The REE chemical composition highlights a local re-incorporation of the REE released from the alteration processes in the APS minerals of

  19. Plasma Deposition of Amorphous Silicon

    Science.gov (United States)

    Calcote, H. F.

    1982-01-01

    Strongly adhering films of silicon are deposited directly on such materials as Pyrex and Vycor (or equivalent materials) and aluminum by a non-equilibrium plasma jet. Amorphous silicon films are formed by decomposition of silicon tetrachloride or trichlorosilane in the plasma. Plasma-jet technique can also be used to deposit an adherent silicon film on aluminum from silane and to dope such films with phosphorus. Ability to deposit silicon films on such readily available, inexpensive substrates could eventually lead to lower cost photovoltaic cells.

  20. Acid Deposition Maps in Spain

    International Nuclear Information System (INIS)

    Animal and monthly deposition velocity and total sulfur deposition maps have been performed for the peninsular Spain for 1992 by using the inferential method. To do this, updated databases with high space and time resolution, for land uses (CORINE) and meteorological information from analysis modelling for the same year, have been utilized. The final result are deposition maps in a 5x5 Km2 grid which allow to assess the methodology used in Europe to obtain the maps of excedances over the critical loads of pollutants. (Author) 32 refs

  1. Particle deposition in ventilation ducts

    Energy Technology Data Exchange (ETDEWEB)

    Sippola, Mark R.

    2002-09-01

    Exposure to airborne particles is detrimental to human health and indoor exposures dominate total exposures for most people. The accidental or intentional release of aerosolized chemical and biological agents within or near a building can lead to exposures of building occupants to hazardous agents and costly building remediation. Particle deposition in heating, ventilation and air-conditioning (HVAC) systems may significantly influence exposures to particles indoors, diminish HVAC performance and lead to secondary pollutant release within buildings. This dissertation advances the understanding of particle behavior in HVAC systems and the fates of indoor particles by means of experiments and modeling. Laboratory experiments were conducted to quantify particle deposition rates in horizontal ventilation ducts using real HVAC materials. Particle deposition experiments were conducted in steel and internally insulated ducts at air speeds typically found in ventilation ducts, 2-9 m/s. Behaviors of monodisperse particles with diameters in the size range 1-16 {micro}m were investigated. Deposition rates were measured in straight ducts with a fully developed turbulent flow profile, straight ducts with a developing turbulent flow profile, in duct bends and at S-connector pieces located at duct junctions. In straight ducts with fully developed turbulence, experiments showed deposition rates to be highest at duct floors, intermediate at duct walls, and lowest at duct ceilings. Deposition rates to a given surface increased with an increase in particle size or air speed. Deposition was much higher in internally insulated ducts than in uninsulated steel ducts. In most cases, deposition in straight ducts with developing turbulence, in duct bends and at S-connectors at duct junctions was higher than in straight ducts with fully developed turbulence. Measured deposition rates were generally higher than predicted by published models. A model incorporating empirical equations based on

  2. Cathodoluminescence in Quaternary carbonate deposits

    Science.gov (United States)

    Braithwaite, Colin J. R.

    2016-05-01

    The cathodoluminescent oscillatory and sectoral growth zones common in crystals formed in ancient limestone successions in a variety of putative environments appear to be rare or absent from Recent and Pleistocene marine carbonate sequences. The factors controlling cathodoluminescence and reasons for this disparity are examined. The cathodoluminescent zones in the cements of ancient rocks have been interpreted as responses to variations in the redox potential of formative pore waters during crystal growth; although similar cathodoluminescent behaviour is recorded from some deposits, including travertines and Quaternary speleothems, formed in what are thought to have been strongly oxidizing environments. The apparent absence of cathodoluminescence in the most Recent and Pleistocene marine deposits, that presumably reflect deposition and diagenesis in environments that are also characteristically oxidized, therefore seems anomalous. The controlling influences on cathodoluminescence are reviewed, together with evidence relating to observations of Pleistocene marine deposits and likely conditions of formation but, where it is present, the mechanism(s) for its development remain elusive.

  3. Hereditary iron and copper deposition

    DEFF Research Database (Denmark)

    Aaseth, Jan; Flaten, Trond Peder; Andersen, Ole

    2007-01-01

    Hereditary deposition of iron (primary haemochromatosis) or copper (Wilson's disease) are autosomal recessive metabolic disease characterized by progressive liver pathology and subsequent involvement of various other organs. The prevalence of primary haemochromatosis is approximately 0.5%, about...

  4. Electrospark deposition for die repair

    Directory of Open Access Journals (Sweden)

    J. Tušek

    2012-01-01

    Full Text Available The electrospark deposition is a process for surfacing of hard metal alloys, e.g. carbides and stellites, on the surfaces of new or old machine elements. In this process, a high current is conducted through an oscillating electrode and a substrate for a very short period of time. In the paper, the process is described and the thickness of deposited layer, chemical composition, dilution rate and the layer roughness are determined.

  5. Uranium deposits in volcanic rocks

    International Nuclear Information System (INIS)

    Twenty-eight papers were presented at the meeting and two additional papers were provided. Three panels were organized to consider the specific aspects of the genesis of uranium deposits in volcanic rocks, recognition criteria for the characterization of such deposits, and approaches to exploration. The papers presented and the findings of the panels are included in the Proceedings. Separate abstracts were prepared for each of these papers

  6. Vapor deposition of hardened niobium

    Science.gov (United States)

    Blocher, Jr., John M.; Veigel, Neil D.; Landrigan, Richard B.

    1983-04-19

    A method of coating ceramic nuclear fuel particles containing a major amount of an actinide ceramic in which the particles are placed in a fluidized bed maintained at ca. 800.degree. to ca. 900.degree. C., and niobium pentachloride vapor and carbon tetrachloride vapor are led into the bed, whereby niobium metal is deposited on the particles and carbon is deposited interstitially within the niobium. Coating apparatus used in the method is also disclosed.

  7. Paradigmatic shifts in exploration process: The role of industry-academia collaborative research and development in discovering the next generation of uranium ore deposits

    International Nuclear Information System (INIS)

    Full text: Uranium exploration increased over the past decade in a sympathetic response to a rapid increase in the price of uranium, inspired by fuel supply-demand, and stock market dynamics. Exploration activity likely peaked during this cycle in 2008, with in excess of 850 companies, engaged in the global exploration of a portfolio of over 3000 projects. Global uranium exploration expenditures for the period 2004-2008 are estimated at US$3.2 billion -from US$130 million in 2004, to an estimated peak of US$1.2 billion in 2008. A major focus of the exploration effort has been on brown-fields exploration in historical uranium districts. Less effort has been devoted to exploration at green-field frontiers. An anticipated significant reduction in global exploration expenditures in 2009, and beyond, is anticipated concurrent with the global recession. There is not much evidence to indicate that significant brand-new, large, and higher grade, uranium deposits have been discovered during this uranium exploration cycle. It is likely that future uranium explorers will need to be more efficient, and effective in their efforts, and to adopt new, and innovative business strategies for their survival, and success. This paper addresses some of the fundamental reasons why major economic discoveries of uranium ore bodies have been elusive over the past two decades, through a cyclical model know as the 'learning curve', using the prolific Athabasca Basin, Saskatchewan, as an exemplar. This model incorporates elements relating exploration expenditure, quantities of discovered uranium, and the sequence of uranium deposit discoveries, to reveal that discovery cycles are epochal in nature, and that they are also intimately related to the development, and deployment of new exploration technologies. The history of uranium exploration is parsed into the early 'prospector' exploration phase (1960- 1980), and the current model driven phase (1981-present). The future of successful uranium

  8. 12 CFR 19.170 - Discovery depositions.

    Science.gov (United States)

    2010-01-01

    ... 12 Banks and Banking 1 2010-01-01 2010-01-01 false Discovery depositions. 19.170 Section 19.170... PROCEDURE Discovery Depositions and Subpoenas § 19.170 Discovery depositions. (a) General rule. In any... deposition of an expert, or of a person, including another party, who has direct knowledge of matters...

  9. A Radon Progeny Deposition Model

    CERN Document Server

    Guiseppe, V E; Hime, A; Rielage, K; Westerdale, S

    2011-01-01

    The next generation low-background detectors operating underground aim for unprecedented low levels of radioactive backgrounds. Although the radioactive decays of airborne radon (particularly Rn-222) and its subsequent progeny present in an experiment are potential backgrounds, also problematic is the deposition of radon progeny on detector materials. Exposure to radon at any stage of assembly of an experiment can result in surface contamination by progeny supported by the long half life (22 y) of Pb-210 on sensitive locations of a detector. An understanding of the potential surface contamination from deposition will enable requirements of radon-reduced air and clean room environments for the assembly of low background experiments. It is known that there are a number of environmental factors that govern the deposition of progeny onto surfaces. However, existing models have not explored the impact of some environmental factors important for low background experiments. A test stand has been constructed to depos...

  10. [Calcium pyrophosphate dihydrate deposition disease].

    Science.gov (United States)

    Koitschev, C; Kaiserling, E; Koitschev, A

    2003-08-01

    Calcium pyrophosphate dihydrate deposition disease (CPPD) of the temporomandibular joint is rare. The disorder is characterized by the presence of crystal deposits within the affected joint. The deposition of crystals in adjacent soft tissue may lead to the formation of pseudotumors. This form of the disease is called tophaceous pseudogout and typically affects the temporomandibular joint. It is difficult to differentiate the disease, particularly from malignant tumors, on the clinical and radiographic findings alone. The diagnosis is based on histological identification of the calcium pyrophosphate crystals. We present an unusually advanced case of tophaceous pseudogout of the temporomandibular joint. The etiology, clinical and diagnostic criteria as well as treatment options are discussed on the basis of our own experience and a review of the literature. PMID:12942180

  11. Sub-aerial tailings deposition

    International Nuclear Information System (INIS)

    The sub-aerial technique involves the systematic deposition of tailings in thin layers and allowing each layer to settle, drain and partially air dry prior to covering with a further layer. Underdrainage produces densities in excess of those achieved by sub-aqueous deposition and any air-drying serves to preconsolidate each layer with a resulting further increase in density. The low permeability of the tailings surface resulting from this deposition technique results in high runoff coefficients and, by decanting the runoff component of direct precipitation, a net evaporation condition can be achieved even in high rainfall areas. An underdrainage system prevents the build-up of excess pore-pressures within the tailings mass and at decommissioning the tailings are fully consolidated and drained thereby eliminating the possibility of any long term seepage. This paper presents a general description of these design concepts, and details of two projects where the concepts have been applied

  12. TULSA UNIVERSITY PARAFFIN DEPOSITION PROJECTS

    Energy Technology Data Exchange (ETDEWEB)

    Cem Sarica; Michael Volk

    2004-06-01

    As oil and gas production moves to deeper and colder water, subsea multiphase production systems become critical for economic feasibility. It will also become increasingly imperative to adequately identify the conditions for paraffin precipitation and predict paraffin deposition rates to optimize the design and operation of these multi-phase production systems. Although several oil companies have paraffin deposition predictive capabilities for single-phase oil flow, these predictive capabilities are not suitable for the multiphase flow conditions encountered in most flowlines and wellbores. For deepwater applications in the Gulf of Mexico, it is likely that multiphase production streams consisting of crude oil, produced water and gas will be transported in a single multiphase pipeline to minimize capital cost and complexity at the mudline. Existing single-phase (crude oil) paraffin deposition predictive tools are clearly inadequate to accurately design these pipelines, because they do not account for the second and third phases, namely, produced water and gas. The objective of this program is to utilize the current test facilities at The University of Tulsa, as well as member company expertise, to accomplish the following: enhance our understanding of paraffin deposition in single and two-phase (gas-oil) flows; conduct focused experiments to better understand various aspects of deposition physics; and, utilize knowledge gained from experimental modeling studies to enhance the computer programs developed in the previous JIP for predicting paraffin deposition in single and two-phase flow environments. These refined computer models will then be tested against field data from member company pipelines.

  13. Nanofriction properties of molecular deposition films

    Institute of Scientific and Technical Information of China (English)

    王强斌; 高芒来; 张嗣伟

    2000-01-01

    The nanofriction properties of Au substrate and monolayer molecular deposition film and multilayer molecular deposition films on Au substrate and the molecular deposition films modified with alkyl-terminal molecule have been investigated by using an atomic force microscope. It is concluded that ( i ) the deposition of molecular deposition films on Au substrate and the modification of alkyl-terminal molecule to the molecular deposition films can reduce the frictional force; (ii) the molecular deposition films with the same terminal exhibit similar nanofriction properties, which has nothing to do with the molecular chain-length and the layer number; (iii) the unstable nanofriction properties of molecular deposition films are contributed to the active terminal of the molecular deposition film, which can be eliminated by decorating the active molecular deposition film with alkyl-terminal molecule, moreover, the decoration of alkyl-terminal molecule can lower the frictional force conspicuously; (iv) the relat

  14. Evolution of U fractionation processes through geologic time : consequences for the variation of U deposit types from Early Earth to Present

    Science.gov (United States)

    Cuney, M.

    2009-12-01

    pegmatoids (Charlebois, Canada), (iv) hydrothermal remobilization in veins (Beaverlodge, Canada) at about 1.75 Ga, and (v) U mineralization related to Na-metasomatism (Lagoa Real, Brazil ; Central Ukraine). After 1.75 Ga, a long period of tectonic quiescence occurred on the Earth, and large intracontinental basins, comprising at their base thick oxidized siliciclastic sequences were formed in many parts of the Nuna. In the Athabasca (Canada) and Kombolgie (Australia) basins, the siliciclastic sediments represented huge aquitards for sodic brines derived from overlying evaporites. The brines became calcic when infiltrated into the basement and leached U dominantly from Paleoproterozoic epicontinental sediments, their anatectic derivatives and high-K-U granites, to form the unconformity related U deposits. By the end of Silurian, with the apparition of land plants, deposits hosted by continental to marginal marine sandstone (roll front, tabular, tectono-lithologic, paleovalleys) became widespread. The largest volcanic related U-deposits are mostly known during the Mesozoic and calcrete are only known during late Caenozoic to Quaternary, but this may by due to the non preservation from erosion of such deposits formed at very shallow levels.

  15. Deposition and Resuspension of Particles

    DEFF Research Database (Denmark)

    Lengweiler, P.; Nielsen, Peter V.; Moser, A.;

    To investigate the physical process of deposition and resuspension of particles in the indoor environment, scale experiments are used and a sampling method is established. The influences of surface orientation and turbulence and velocity of the air on the dust load on a surface are analysed....

  16. ECONOMIC GEOLOGY (2)NONMETALS DEPOSITS

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    <正>20082329 Chen Wang(China University of Geosciences,Beijing 100083,China) Control Factors on Distribution of Carboniferous Bauxite Deposits in Western Henan Province (Geotectonica et Metallogenia,ISSN1001—1552,CN44—1595/P,31(4),2007,p.452—456,1 illus.,10 refs.) Key words:bauxite,mineralization con- trols,Henan Province

  17. A remote coal deposit revisited

    DEFF Research Database (Denmark)

    Bojesen-Kofoed, Jørgen A.; Kalkreuth, Wolfgang; Petersen, Henrik I.;

    2012-01-01

    environment related to meandering river channels. Spores and pollen in the lower fluvial deposits reflect abundant vegetation of ferns along the river banks. In contrast, a sparse spore and pollen flora in the coals show a mixed vegetation of ferns and gymnosperms. Based on proximate and petrographic analyses...

  18. Simple Chemical Vapor Deposition Experiment

    Science.gov (United States)

    Pedersen, Henrik

    2014-01-01

    Chemical vapor deposition (CVD) is a process commonly used for the synthesis of thin films for several important technological applications, for example, microelectronics, hard coatings, and smart windows. Unfortunately, the complexity and prohibitive cost of CVD equipment makes it seldom available for undergraduate chemistry students. Here, a…

  19. Electro-spark deposition technology

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, R.N. [Pacific Northwest National Lab., Richland, WA (United States)

    1997-12-01

    Electro-Spark Deposition (ESD) is a micro-welding process that uses short duration, high-current electrical pulses to deposit or alloy a consumable electrode material onto a metallic substrate. The ESD process was developed to produce coatings for use in severe environments where most other coatings fail. Because of the exceptional damage resistance of these coatings, and the versatility of the process to apply a wide variety of alloys, intermetallics, and cermets to metal surfaces, the ESD process has been designated critical to the life and economy of the advanced fossil energy systems as the higher temperatures and corrosive environments exceed the limits of known structural materials to accommodate the service conditions. Developments include producing iron aluminide-based coatings with triple the corrosion resistance of the best previous Fe{sub 3}Al coatings, coatings with refractory metal diffusion barriers and multi layer coatings for achieving functionally gradient properties between the substrate and the surface. A new development is the demonstration of advanced aluminide-based ESD coatings for erosion and wear applications. One of the most significant breakthroughs to occur in the last dozen years is the discovery of a process regime that yields an order of magnitude increase in deposition rates and achievable coating thicknesses. Achieving this regime has required the development of advanced ESD electronic capabilities. Development is now focused on further improvements in deposition rates, system reliability when operating at process extremes, and economic competitiveness.

  20. Systems for Guaranteeing Bank Deposits

    OpenAIRE

    Florin Untaru

    2013-01-01

    The advent of the financial crisis and the latest event that occurred in Cyprus bring new light to how states intervene when commercial banks are facing the risk of bankruptcy. While until now institutions had a clear traditional role to protect depositors, currently there is a trend to transfer damage to companies and individuals that hold deposits.

  1. Chemical-vapor-deposition reactor

    Science.gov (United States)

    Chern, S.

    1979-01-01

    Reactor utilizes multiple stacked trays compactly arranged in paths of horizontally channeled reactant gas streams. Design allows faster and more efficient deposits of film on substrates, and reduces gas and energy consumption. Lack of dead spots that trap reactive gases reduces reactor purge time.

  2. 开放教育资源:创新、研究与实践--访阿萨巴斯卡大学罗里·麦格雷尔教授%Open Educational Resources:Innovation, Research and Practice:An Interview with Prof.Rory McGreal of Athabasca University

    Institute of Scientific and Technical Information of China (English)

    王志军; 李馨; 赵云建

    2014-01-01

    原因、阿萨巴斯卡大学在积极参与开放教育资源实践过程中的收获;最后,他推荐了两本开放教育资源相关的著作。%Editor's Commentary:Professor Rory McGreal is a professor in the Centre for Distance Education at Athabasca University which is one of the most famous Open University in the world. He is also the director of the Technology Enhanced Knowledge Research Institute (TEKRI). Formerly, he served as the Associate Vice President Research in Athabasca University. Internationally, he is the Open Educational Resource Chair for many orgnizations including UNESCO\\CoL. He has severed as a member of the Global Advisory Council of the Observatory of Borderless Higher Education. Presently, he is Director of the OER Foundation, and a member of the Distance Education Hub, Advisory Group, Australia. He is also a co-Editor of the International Review of Research in Open and Distance Learning (IRRODL) from 2013, and on the editorial board or a reviewer for a variety of scholarly journals. For his excellent contribution in distance education, he was given the Wedemeyer Award for Distance Education practitioner in 2002.His present research interests include the use of Open Educational Resources and standards in technology assisted learning, particularly in the development and application of learning objects. He is also researching how these would be applied and formatted on mobile devices for M-learning. This interview is focus on the topic of Open Educational Resources (OER), the research, innovation and practices related to OER are deeply introduced to provide a three-dimensional, comprehensive, in-depth and up to date international research and practice panorama for readers. Professor Rory McGreal ifrst introduced the relationship between MOOCs and OER, then the reason for open of educational resource is in-depth analyzed. And then the following topics also introduced in this interview:how to effectively use and develop OER in the era

  3. Adhesion Strength of Biomass Ash Deposits

    DEFF Research Database (Denmark)

    Laxminarayan, Yashasvi; Jensen, Peter Arendt; Wu, Hao;

    2016-01-01

    . Therefore, timely removal of ash deposits is essential for optimal boiler operation. In order to improve the qualitative and quantitative understanding of deposit shedding in boilers, this study investigates the shear adhesion strength of biomass ash deposits on superheater tubes. Artificial biomass ash...... deposits were prepared on superheater tubes and sintered in an oven at temperatures up to 1000 °C. Subsequently, the deposits were sheared off by an electrically controlled arm, and the corresponding adhesion strength was measured. The results reveal the effect of temperature, ash/deposit composition......, sintering duration, and steel type on the adhesion strength....

  4. Vapor deposition of tantalum and tantalum compounds

    International Nuclear Information System (INIS)

    Tantalum, and many of its compounds, can be deposited as coatings with techniques ranging from pure, thermal chemical vapor deposition to pure physical vapor deposition. This review concentrates on chemical vapor deposition techniques. The paper takes a historical approach. The authors review classical, metal halide-based techniques and current techniques for tantalum chemical vapor deposition. The advantages and limitations of the techniques will be compared. The need for new lower temperature processes and hence new precursor chemicals will be examined and explained. In the last section, they add some speculation as to possible new, low-temperature precursors for tantalum chemical vapor deposition

  5. Paradigmatic Shifts in Exploration Process: The Role of Industry-Academia Collaborative Research and Development in Discovering the Next Generation of Uranium Ore Deposits

    International Nuclear Information System (INIS)

    Uranium exploration increased over the past decade in a sympathetic response to a rapid increase in the price of uranium, inspired by fuel supply-demand and stock market dynamics. Exploration activity likely peaked during this cycle in 2008 with in excess of 900 companies engaged in the global exploration of a portfolio of over 3000 projects. Global uranium exploration expenditures for the period 2004–2008 are estimated at US$3.2 billion — from US$130 million in 2004 to an estimated peak of US$1.2 billion in 2008. A major focus of the exploration effort has been on brown-fields exploration in historical uranium districts. Less effort has been devoted to exploration at green-field frontiers. A significant reduction in global exploration expenditures in 2009 and beyond is anticipated concurrent with the global recession. There is not much evidence to indicate that brand-new, large, and higher grade, uranium deposits have been discovered during this uranium exploration cycle. It is likely that future uranium explorers will need to be more efficient and effective in their efforts and to adopt new and innovative business strategies for their survival and success. This paper addresses some of the fundamental reasons why major economic discoveries of uranium ore bodies have been elusive over the past two decades, through a cyclical model know as the ‘learning curve’, using the prolific Athabasca Basin, Saskatchewan, as an exemplar. This model relates exploration expenditure, quantities of discovered uranium, and the sequence of uranium deposit discoveries, to reveal that discovery cycles are epochal in nature and that they are also intimately related to the development and deployment of new exploration technologies. The history of uranium exploration is parsed into the early ‘prospector’ exploration phase (1960–1980) and the current ‘model driven’ phase (1981–present). The future of successful uranium exploration is envisaged as

  6. Computational study of wax deposition in pipeline

    Science.gov (United States)

    Duan, Jimiao; Gong, Jing; Liu, Huishu

    2013-07-01

    Wax deposition in subsea pipelines is one of the flow assurance problems for oil and gas production. In contrast to many studies about single phase wax deposition, gas-oil wax deposition studies are very limited. The wax deposition mechanism and model prediction are restricted by many factors such as hydrodynamic and thermal when multiphase flow is involved. Wax deposition modeling becomes complicated under multiphase flowing conditions. wax deposition is depended by the flow pattern. The stratified flow is one of the most common flow patterns in the actual subsea gas-oil flowing conditions. In this work, numerical methods are used to study wax deposition in oil-gas stratified flow through a pipe. Based on the flow analysis about stratified flow, the non-isothermal heat and mass transfer is calculated. The temperature profile of the oil and the concentration profile of wax in oil are obtained. The change of the oil-gas interface i.e. the liquid holdup throughout the pipe must be taken into the heat and mass balance. The valid wax deposition surface must be taken into the wax deposition modeling by establishing function of the liquid holdup and the wetted area by oil. The molecular diffusion is as the deposition mechanism. The increase of the wax fraction in the deposit as a function of time depends on the mass flux from the oil deposit interface into the gel and the growth of the deposit thickness depends on the difference between the mass flux from the bulk oil to the oil deposit interface and the mass flux from the interface into the deposit. In addition, the growth of the wax deposit as a function of time along with the effect oil flow rate, gas flow rate and the inlet temperature are discussed. The presence of gas significantly reduces the severity of wax deposition by altering the heat and mass transfer characteristics.

  7. Thunderstorms Increase Mercury Wet Deposition.

    Science.gov (United States)

    Holmes, Christopher D; Krishnamurthy, Nishanth P; Caffrey, Jane M; Landing, William M; Edgerton, Eric S; Knapp, Kenneth R; Nair, Udaysankar S

    2016-09-01

    Mercury (Hg) wet deposition, transfer from the atmosphere to Earth's surface by precipitation, in the United States is highest in locations and seasons with frequent deep convective thunderstorms, but it has never been demonstrated whether the connection is causal or simple coincidence. We use rainwater samples from over 800 individual precipitation events to show that thunderstorms increase Hg concentrations by 50% relative to weak convective or stratiform events of equal precipitation depth. Radar and satellite observations reveal that strong convection reaching the upper troposphere (where high atmospheric concentrations of soluble, oxidized mercury species (Hg(II)) are known to reside) produces the highest Hg concentrations in rain. As a result, precipitation meteorology, especially thunderstorm frequency and total rainfall, explains differences in Hg deposition between study sites located in the eastern United States. Assessing the fate of atmospheric mercury thus requires bridging the scales of global transport and convective precipitation. PMID:27464305

  8. Atmosfærisk deposition

    DEFF Research Database (Denmark)

    Ellermann, T.; Hertel, O.; Kemp, K.;

    Kvælstofdepositionen til danske havområder, fjorde, vige og bugte er for 2001 blevet beregnet til 118 ktons N, hvilket er ca. 20 % lavere end i 2000. Tilsvarende er depositionen til landområderne beregnet til 87 ktons N, hvilket svarer til deposition i 2000. Den primære årsag til den højere...... deposition for 1999-2001, i forhold til tidligere år, er ændringer i beregningsmetoden. Den samlede kvælstofdeposition til farvandene er faldet svagt i perioden 1989-2001. Depositionen til landoverflader skønnes ikke ændret betydeligt. Depositionen af svovlforbindelser til danske landområder er for 2001...

  9. Complexing and hydrothermal ore deposition

    CERN Document Server

    Helgeson, Harold C

    1964-01-01

    Complexing and Hydrothermal Ore Deposition provides a synthesis of fact, theory, and interpretative speculation on hydrothermal ore-forming solutions. This book summarizes information and theory of the internal chemistry of aqueous electrolyte solutions accumulated in previous years. The scope of the discussion is limited to those aspects of particular interest to the geologist working on the problem of hydrothermal ore genesis. Wherever feasible, fundamental principles are reviewed. Portions of this text are devoted to calculations of specific hydrothermal equilibriums in multicompone

  10. Electrochemical Depositions in Ionic Liquids

    OpenAIRE

    De Vreese, Peter

    2013-01-01

    In this PhD thesis, several aspects of the electrodeposition of metals and alloys in ionic liquids were investigated. First, the deposition of brass from choline acetate was studied. Secondly, the electrodeposition of pure molybdenum from ionic liquids based on phosphonium chloride and zinc chloride was treated. In each case, the influence of water, either as a main constituent of the electrolyte or an impurity, was investigated. When comparing electrochemical processes such as electrodeposit...

  11. Electro-spark deposition technology

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, R.N. [Pacific Northwest Lab., WA (United States)

    1996-08-01

    Electro-Spark Deposition (ESD) is a micro-welding process that uses short duration, high-current electrical pulses to deposit or alloy a consumable electrode material onto a metallic substrate. The ESD process was developed to produce coatings for use in severe environments where most other coatings fail. Because of the exceptional damage resistance of these coatings, and the versatility of the process to apply a wide variety of alloys, intermetallics, and cermets to metal surfaces, the ESD process has been designated as one of the enabling technologies for advanced energy systems. Developments include producing iron aluminide-based coatings with triple the corrosion resistance of the best previous Fe{sub 3}Al coatings, coatings with refractory metal diffusion barriers and multi layer coatings for achieving functionally gradient properties between the substrate and the surface. One of the most significant breakthroughs to occur in the last dozen years is the discovery of a process regime that promises an order of magnitude increase in deposition rates and achievable coating thicknesses. Since this regime borders on and exceeds the normal operating limits of existing ESD electronic equipment, development is in progress to produce equipment that can consistently and reliably achieve these conditions for a broad range of materials. Progress so far has resulted in a consistent 500% increase in deposition rates, and greater rates still are anticipated. Technology transfer activities are a significant portion of the ESD program effort. Notable successes now include the start-up of a new business to commercialize the ESD technology, the incorporation of the process into the operations of a major gas turbine manufacturer, major new applications in gas turbine blade and steam turbine blade protection and repair, and in military, medical, metal-working, and recreational equipment applications.

  12. Crediting Tritium Deposition in Accident Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Murphy, C.E. Jr.

    2001-06-20

    This paper describes the major aspects of tritium dispersion phenomenology, summarizes deposition attributes of the computer models used in the DOE Complex for tritium dispersion, and recommends an approach to account for deposition in accident analysis.

  13. Isotropic metal deposition technique for metamaterials fabrication

    DEFF Research Database (Denmark)

    Malureanu, Radu; Andryieuski, Andrei; Lavrinenko, Andrei

    2009-01-01

    In this work we will present the first steps taken towards isotropic deposition of thin metallic layers on dielectric substrates. The deposition takes place in aqueous environment thus making it both cheap and easy to be implemented....

  14. CTD_DATABASE - Cascadia tsunami deposit database

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The Cascadia Tsunami Deposit Database contains data on the location and sedimentological properties of tsunami deposits found along the Cascadia margin. Data have...

  15. Adhesion Strength of Biomass Ash Deposits

    OpenAIRE

    Laxminarayan, Yashasvi; Jensen, Peter Arendt; Wu, Hao; Bøjer, M.; Jappe Frandsen, Flemming; Glarborg, Peter

    2016-01-01

    Ash deposition on boiler surfaces is a major problem encountered during biomass combustion. Ash deposition adversely influences the boiler efficiency, may corrode heat transfer surfaces, and may even completely block flue gas channels in severe cases, causing expensive unscheduled boiler shutdowns. Therefore, timely removal of ash deposits is essential for optimal boiler operation. In order to improve the qualitative and quantitative understanding of deposit shedding in boilers, this study in...

  16. 75 FR 6348 - Deposit of Biological Materials

    Science.gov (United States)

    2010-02-09

    ... Patent and Trademark Office Deposit of Biological Materials ACTION: Proposed collection; comment request....Fawcett@uspto.gov . Include ``0651-0022 Deposit of Biological Materials comment'' in the subject line of....Hanlon@uspto.gov . SUPPLEMENTARY INFORMATION: I. Abstract The deposit of biological materials as part...

  17. Towards a genetic classification of uranium deposits

    International Nuclear Information System (INIS)

    As the IAEA's uranium deposit classification is based on the deposit nature and morphology, some deposits which have been formed by very different genetic processes and located in very different geological environments, are grouped according to this classification. In order to build up a reliable genetic classification based on the mechanism at the origin of the formation of the deposit, the author presents the five main categories according to which uranium deposits can be classified: magmatic, hydrothermal, evapotranspiration, syn-sedimentary, and infiltration of meteoric water

  18. Particle deposition in granular media: Progress report

    Energy Technology Data Exchange (ETDEWEB)

    Tien, Chi

    1987-01-01

    This paper discusses topics on particle deposition in granular media. The six topics discussed are: experimental determination of initial collection efficiency in granular beds - an assessment of the effect of instrument sensitivity and the extent of particle bounce-off; deposition of polydispersed aerosols in granular media; in situ observation of aerosol deposition in a two-dimensional model filter; solid velocity in cross-flow granular moving bed; aerosol deposition in granular moving bed; and aerosol deposition in a magnetically stabilized fluidized bed. (LSP)

  19. Depositing Materials on the Micro- and Nanoscale

    DEFF Research Database (Denmark)

    Mar, Mikkel Dysseholm; Herstrøm, Berit; Shkondin, Evgeniy;

    2014-01-01

    that can be used separately or in combination to give the micro/nano system the properties needed. These techniques and film properties are presented. ALD (Atomic Layer Deposition) is good for very thin films (down to monolayers) with extremely good stepcoverage and extremely good control of the layer...... is good for high quality thin film metal deposition e.g. for electrical leads or surfaceplasmonic devices. MVD (Molecular Vapor Deposition) is used for making anti stiction coating. Below is shown an example of Atomic Layer Deposition which is a self-terminating chemical vapor deposition technique based...

  20. Deposit Reserve Rate No Panacea

    Institute of Scientific and Technical Information of China (English)

    Mark; A.DeWeaver

    2006-01-01

    To rein in runaway investment, China's central bank, the People's Bank of China (PBOC), took several measures in mid-June, including the most dramatic step of raising the deposit reserve rate by 0.5 percentage point According to Mark A. DeWeaver, who manages Quantrarian Asia Hedge, a fund that invests in Asian equities, the PBOC's measures may lower money supply growth in the short term; that is, the effect of these measures "may be only temporary." He believes that "attempts to slow money supply growth ...

  1. Minerals deposited as thin films

    International Nuclear Information System (INIS)

    Free matrix effects are due to thin film deposits. Thus, it was decided to investigate this technique as a possibility to use pure oxide of the desired element, extrapolating its concentration from analytical curves made with avoiding, at the same time, mathematical corrections. The proposed method was employed to determine iron and titanium concentrations in geological samples. The range studied was 0.1-5%m/m for titanium and 5-20%m/m for iron. For both elements the reproducibility was about 7% and differences between this method and other chemical determinations were 15% for titanium and 7% for iron. (Author)

  2. Metal deposition using seed layers

    Science.gov (United States)

    Feng, Hsein-Ping; Chen, Gang; Bo, Yu; Ren, Zhifeng; Chen, Shuo; Poudel, Bed

    2013-11-12

    Methods of forming a conductive metal layers on substrates are disclosed which employ a seed layer to enhance bonding, especially to smooth, low-roughness or hydrophobic substrates. In one aspect of the invention, the seed layer can be formed by applying nanoparticles onto a surface of the substrate; and the metallization is achieved by electroplating an electrically conducting metal onto the seed layer, whereby the nanoparticles serve as nucleation sites for metal deposition. In another approach, the seed layer can be formed by a self-assembling linker material, such as a sulfur-containing silane material.

  3. Energetic deposition of thin metal films

    CERN Document Server

    Al-Busaidy, M S K

    2001-01-01

    deposited films. The primary aim of this thesis was to study the physical effect of energetic deposition metal thin films. The secondary aim is to enhance the quality of the films produced to a desired quality. Grazing incidence X-ray reflectivity (GIXR) measurements from a high-energy synchrotron radiation source were carried out to study and characterise the samples. Optical Profilers Interferometery, Atomic Force Microscope (AFM), Auger electron spectroscopy (AES), Medium energy ion spectroscopy (MEIS), and the Electron microscope studies were the other main structural characterisation tools used. AI/Fe trilayers, as well as multilayers were deposited using a Nordico planar D.C. magnetron deposition system at different voltage biases and pressures. The films were calibrated and investigated. The relation between energetic deposition variation and structural properties was intensely researched. Energetic deposition refers to the method in which the deposited species possess higher kinetic energy and impact ...

  4. Thermoluminescence dating of the british coversand deposits

    Science.gov (United States)

    Bateman, M. D.

    Coversand deposits, thought to be of Lateglacial age are found in Britain in North Lincolnshire, South-West Lancashire and Central East Anglia. A comprehensive dating study of them, using thermoluminescence (TL) techniques, is currently underway in an attempt to link the British coversand deposits to the European coversand chronology. Initial results from four of the British coversand sites sampled are presented. The 26 TL dates from 14 samples show that in Lincolnshire aeolian deposition took place from 12.5 ka to I1 ka. Cessation of the initial sand deposition was synchronous with this in Lancashire, but sand deposition occurred significantly earlier in East Anglia. The upper layers of aeolian sand in Lancashire are much younger and are attributed to Holocene reworking. On the basis of these dates, Lincolnshire and Lancashire coversand deposition occurred at a similar time to the Younger Coversand II, whilst East Anglian coversand deposition coincided with the Younger Coversand I phase in the European coversand chronology.

  5. Digital electrospray for controlled deposition.

    Science.gov (United States)

    Deng, Weiwei; Waits, C Mike; Gomez, Alessandro

    2010-03-01

    Many novel functional structures are now fabricated by controlled deposition as a maskless, bottom-up fabrication technique. These applications require rapid and precise deposition of minute amounts of solutions/suspensions or their ultimate particle products in predefined patterns. The electrospray is a promising alternative to the commonly used inkjet printing because it can easily handle highly viscous liquid, avoid high shear rates, and has low risk of clogging. We demonstrate a proof-of-concept digital electrospray. This system consists of a 61-nozzle array microfabricated in silicon and a 61-element digital extractor fabricated using flexible polyimide substrates. "Digital" refers to the state of each electrospray source that can be tuned either on or off independently and responsively. We showed a resolution of 675 mum and a response frequency up to 100 Hz. With similar design and industry standard fabrication procedures, it is feasible to scale up the system to O(1000) sources with spatial resolution better than 250 mum and a O(kHz) response frequency. The latter is controlled by the viscous damping time. PMID:20370220

  6. Nanofriction properties of molecular deposition films

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The nanofriction properties of Au substrate and monolayer molecular deposition film and multilayer molecular deposition films on Au substrate and the molecular deposition films modified with alkyl-terminal molecule have been investigated by using an atomic force microscope. It is concluded that (ⅰ) the deposition of molecular deposition films on Au substrate and the modification of alkyl-terminal molecule to the molecular deposition films can reduce the frictional force; (ⅱ) the molecular deposition films with the same terminal exhibit similar nanofriction properties, which has nothing to do with the molecular chain-length and the layer number; (ⅲ) the unstable nanofriction properties of molecular deposition films are contributed to the active terminal of the molecular deposition film, which can be eliminated by decorating the active molecular deposition film with alkyl-terminal molecule, moreover, the decoration of alkyl-terminal molecule can lower the frictional force conspicuously; (ⅳ) the relative humidity affects the frictional force; the higher the RH, the lower the frictional force.

  7. Oil shales, evaporites and ore deposits

    Science.gov (United States)

    Eugster, Hans P.

    1985-03-01

    The relationships between oil shales, evaporites and sedimentary ore deposits can be classified in terms of stratigraphic and geochemical coherence. Oil shale and black shale deposition commonly follows continental red beds and is in turn followed by evaporite deposition. This transgressive-regressive sequence represents an orderly succession of depositional environments in space and time and results in stratigraphic coherence. The amount of organic carbon of a sediment depends on productivity and preservation, both of which are enhanced by saline environments. Work on Great Salt Lake. Utah, allows us to estimate that only 5% of TOC originally deposited is preserved. Inorganic carbonate production is similar to TOC production, but preservation is much higher. Oil shales and black shales commonly are enriched in heavy metals through scavenging by biogenic particles and complexation by organic matter. Ore deposits are formed from such rocks through secondary enrichment processes, establishing a geochemical coherence between oil shales and ore deposits. The Permian Kupferschiefer of N. Europe is used as an example to define a Kupferschiefer type (KST) deposit. Here oxygenated brines in contact with red beds become acidified through mineral precipitation and acquire metals by dissolving oxide coatings. Oxidation of the black shale leads to further acid production and metal acquisition and eventually to sulfide deposition along a reducing front. In order to form ore bodies, the stratigraphic coherence of the red bed-black shale-evaporite succession must be joined by the geochemical coherence of the ore body-evaporite-black shale association. The Cretaceous Cu-Zn deposits of Angola, the Zambian Copperbelt as well as the Creta, Oklahoma, deposits are other KST examples. In the Zambian Copperbelt, evaporites are indicated by the carbonate lenticles thought to be pseudomorphs after gypsum-anhydrite nodules. MVT deposits are also deposited by acid brines, but at more

  8. Analysing the Cenozoic depositional record

    DEFF Research Database (Denmark)

    Goledowski, Bartosz; Clausen, O.R.; Nielsen, S.B.

    between the global climate record (oxygen isotopes) and lithology variations on the Eocene-Oligocene transition in the eastern North Sea. Due to the strongly limited time resolution of low temperature thermochronology, the Cenozoic sedimentary record potentially provides the most detailed history of...... lower limit to erosion rate in source areas of the respective sedimentary bodies. The lower limit arises because some erosional products are transported out of the mapped area, and some erosion is caused by chemical dissolution. The development of the source areas will be modelled using surface process...... models. The matrix mass deposition history will be compared with the paleoclimate record (e.g. oxygen isotope curves) to see if the previously observed correlation in the eastern North Sea can be extended to other ages and locations.  ...

  9. UFOMOD - atmospheric dispersion and deposition

    International Nuclear Information System (INIS)

    The report gives an introduction into the modelling of atmospheric dispersion and deposition which has been implemented in the new program system UFOMOD for assessing the consequences after nuclear accidents. According to the new structure of UFOMOD, different trajectory models with ranges of validity near to the site and at far distances are applied. Emphasis is laid on the description of the segmented plume model MUSEMET and its affilated submodels, being the removal of activity from the cloud by dry and wet deposition, and special effects like plume rise and the behaviour of plumes released into building wakes. In addition, the evaluation of γ-dose correction factors to take account of the finite extent of the radioactive plume in the near range (up to about 20 km) are described. Only brief introductions are given into the principles of the other models available: the puff model RIMPUFF, the long-range puff model MESOS, and the special straight-line Gaussian model ISOLA which are used if low-level long-duration releases are considered. To define starting times of weather sequences and the probabilities of occurrence of these sequences, it is convenient to perform stratified sampling. Therefore, the preprocessing program package METSAM has been developed to perform for generic ACAs a random sampling of weather sequences out off a population of classified weather conditions. The sampling procedure and a detailed input/output (I/O) description is presented and an additional appendix, respectively. A general overview on the I/O structure of MUSEMET as well as a brief user guide to run the KfK version of the MESOS code are also given in the appendix. (orig.)

  10. Update on calcium pyrophosphate deposition.

    Science.gov (United States)

    Abhishek, Abhishek; Doherty, Michael

    2016-01-01

    Calcium pyrophosphate crystal deposition (CPPD) associates with ageing, osteoarthritis (OA), uncommon metabolic diseases, mutations and polymorphisms in the ankylosis human gene (ANKH). CPPD is frequently polyarticular, occurs due to a generalised articular predisposition, and the association between CPPD and OA is joint specific, for example CPPD associates with knee OA, but not with hip OA. Other recently identified associations include knee malalignment (knee CC), low cortical BMD and soft-tissue calcification. CPPD is generally asymptomatic. A recent study reported that knees with OA plus CC at the index joint, or at distant joints (in absence of index joint CC), were more likely to have attrition. CPPD can cause acute CPP crystal arthritis, chronic CPP crystal inflammatory arthritis, and is frequently present in joints with OA. Joint aspiration remains the gold standard for diagnosing CPPD, although other promising techniques are emerging. Patients with polyarticular or young onset CPPD should be screened for underlying metabolic abnormalities, however, such testing can be unrewarding. The treatment of CPPD is symptomatic. Acute CPP crystal arthritis is treated with rest, local application of ice-packs, joint aspiration, colchicine and/or intra-articular corticosteroid injection (once infection is excluded). Colchicine, low-dose corticosteroids, hydroxychloroquine and radiosynovectomy are recommended for the treatment of chronic or recurrent acute CPP crystal arthritis. Recent RCTs did not confirm any benefit from methotrexate, and although there is increasing interest in the use of anti-IL1 agents for acute or chronic CPP crystal arthritis, their efficacy has not been formally examined. Unlike gout, currently there are no treatments to eliminate CPP crystal deposits. PMID:27586801

  11. Laboratory Deposition Apparatus to Study the Effects of Wax Deposition on Pipe Magnetic Field Leakage Signals

    Directory of Open Access Journals (Sweden)

    Karim Mohd Fauzi Abd

    2014-07-01

    Full Text Available Accurate technique for wax deposition detection and severity measurement on cold pipe wall is important for pipeline cleaning program. Usually these techniques are validated by conventional techniques on laboratory scale wax deposition flow loop. However conventional techniques inherent limitations and it is difficult to reproduce a predetermine wax deposit profile and hardness at designated location in flow loop. An alternative wax deposition system which integrates modified pour casting method and cold finger method is presented. This system is suitable to reproduce high volume of medium hard wax deposit in pipe with better control of wax deposit profile and hardness.

  12. Review of cooling tower drift deposition models

    Energy Technology Data Exchange (ETDEWEB)

    Chen, N.C.J.

    1977-05-04

    The behavior, basic assumptions, and limitations of ten different models for calculating the drift deposition rate from wet cooling towers are reviewed and then their predicted results for such deposition with a common set of input parameters are compared. The predicted maximum deposition differs among the models by two orders of magnitude with a wide range in peak location. Comments and suggestions to improve the models are included.

  13. Vapor wall deposition in Teflon chambers

    OpenAIRE

    Zhang, X; R. H. Schwantes; R. C. McVay; H Lignell; M. M. Coggon; Flagan, R C; Seinfeld, J.H.

    2014-01-01

    Teflon chambers are ubiquitous in studies of atmospheric chemistry. Secondary organic aerosol (SOA) formation can be substantially underestimated owing to deposition of SOA-forming compounds to chamber walls. We present here an experimental protocol to constrain the nature of wall deposition of organic vapors in Teflon chambers. We measured the wall deposition rates of 25 oxidized organic compounds generated from the photooxidation of isoprene, toluene, α-pinene, and dodecan...

  14. CPI Overruns Deposit Reserve Rate Growth

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    @@ The People's Bank of China has announced its intention to raise the deposit reserve rate again,less than one month after the last rate increase, this means that the deposit reserve rate has increased a total of ten times this year. However, this time the central bank increased the deposit reserve rate by a full 1 percent, a bigger increase than the last nine adjustments of 0.5 percent.

  15. FTIR analysis of aviation fuel deposits

    Science.gov (United States)

    Helmick, L. S.; Seng, G. T.

    1984-01-01

    Five modes of operation of the Nicolet 7199 Fourier Transform Infrared Spectrophotometer have been evaluated for application in analysis of the chemical structure of accelerated storage/thermal deposits produced by jet fuels. Using primarily the absorption and emission modes, the effects of fuel type, stress temperature, stress time, type of spiking agent, spiking agent concentration, fuel flow, and post-depositional treatment on the chemical nature of fuel deposits have been determined.

  16. Bilateral Pseudoexfoliation Deposits on Intraocular Lens Implants

    OpenAIRE

    Elena Bonafonte Marquez; Sergio Bonafonte Royo

    2015-01-01

    We present a rare case of bilateral pseudoexfoliative deposits on both intraocular lens (IOL) implants in an 83-year-old woman with no other associated pathology, 5 years after cataract surgery. Pseudoexfoliation syndrome is the most common cause of secondary open-angle glaucoma worldwide and these deposits are usually found on the natural lens. The fact that pseudoexfoliative deposits have been found on IOL implants implies the need for a thorough examination in pseudophakic patients, for i...

  17. Solid Organic Deposition During Gas Injection Studies

    DEFF Research Database (Denmark)

    Dandekar, Abhijit Y.; Andersen, Simon Ivar; Stenby, Erling Halfdan

    2000-01-01

    . The asphaltene content of the different oil samples were determined by the TP 143 method. The standard asphaltenes and the solid organic deposit recovered from the swelling tests were analyzed using FTIR, HPLC-SEC and H-1 NMR. The aim of these analyses is to reveal the molecular nature of the deposits formed...... during the gas injection process in comparison with the standard asphaltenes in order to understand the mechanisms involved in asphaltene deposition....

  18. DETERMINATION METHODS OF THE ATMOSPHERIC DEPOSITION

    Directory of Open Access Journals (Sweden)

    Hanefi BAYRAKTAR

    2004-01-01

    Full Text Available The atmospheric deposition is defined as the turning back of pollutants to the earth, emitted either from natural or anthropogenic sources, after the some transformation stages of pollutants in the atmosphere. Because the atmospheric deposition (wet and dry deposition damages water, plants, soil, historical and other structures, it is one of the popular subject to study in recent years. However, it is difficult to study the determination of atmospheric deposition because it has a lot of various and changeable parameters. So, there is a need for various systems and surfaces for sampling. As wet deposition can be sampled by manual and automatic systems, the different developed sampling surfaces which minimize the effect of various topographic and meteorological conditions are used to sample dry deposition. Studies show that sampling with water surfaces is more suitable to collect both dry and bulk deposition. In this study, atmospheric deposition and its determination methods were explained and sampling surfaces that were developed to collect deposition of different air pollutants compared each other.

  19. Structural characterization of MAPLE deposited lipase biofilm

    International Nuclear Information System (INIS)

    Highlights: • Lipase from Candida Rugosa was deposited by Matrix Assisted Pulsed Laser Evaporation (MAPLE) on KBr pellets, mica and glass substrate. • The deposited film was characterized morphologically and structurally by optical microscopy, SEM and FTIR analysis. • Results of characterization underlined a phenomenon of aggregation taking place. • The aggregation phenomenon was reversible since lipase showed activity in the transesterification reaction between soybean oil and isopropyl alcohol once detached from the substrate. - Abstract: Lipases (triacylglycerol ester hydrolases) are enzymes used in several industrial applications. Enzymes immobilization can be used to address key issues limiting widespread application at industrial level. Immobilization efficiency is related to the ability to preserve the native conformation of the enzyme. MAPLE (Matrix Assisted Pulsed Laser Evaporation) technique, a laser deposition procedure for treating organic/polymeric/biomaterials, was applied for the deposition of lipase enzyme in an ice matrix, using near infrared laser radiation. Microscopy analysis showed that the deposition occurred in micrometric and submicrometric clusters with a wide size distribution. AFM imaging showed that inter-cluster regions are uniformly covered with smaller aggregates of nanometric size. Fourier transform infrared spectroscopy was used for both recognizing the deposited material and analyzing its secondary structure. Results showed that the protein underwent reversible self-association during the deposition process. Actually, preliminary tests of MAPLE deposited lipase used for soybean oil transesterification with isopropyl alcohol followed by gas chromatography–mass spectrometry gave results consistent with undamaged deposition of lipase

  20. Mass deposition from inspired polydisperse aerosols

    Energy Technology Data Exchange (ETDEWEB)

    Rudolf, G.; Gebhart, J.; Heyder, J.; Scheuch, G.; Stahlhofen, W. (Gesellschaft fuer Strahlen- und Umweltforschung m.b.H., Frankfurt (Germany, F.R.). Inst. fuer Biophysikalische Strahlenforschung)

    1988-01-01

    Mass deposition of polydisperse hydrophobic aerosol particles in various regions of the human respiratory tract has been calculated using a semi-empirical deposition model and assuming lognormal particle size distributions. The effects of polydispersity, breathing mode (nose versus mouth breathing), breathing pattern, particle size and density upon mass deposition are discussed. Significant differences are found from the model predictions of the ICRP TASK GROUP ON LUNG DYNAMICS (1966) and later ICRP recommendations. The influence of the geometric standard deviation of the size distribution upon mass deposition depends on particle size, and a simple explanation of this effect is introduced. (author).

  1. Structural characterization of MAPLE deposited lipase biofilm

    Energy Technology Data Exchange (ETDEWEB)

    Aronne, Antonio [Department of Chemical Engineering, Materials and Industrial Production, Università degli Studi di Napoli Federico II, Piazzale V. Tecchio 80, 80125 Napoli (Italy); Ausanio, Giovanni; Bloisi, Francesco [CNR-SPIN and Department of Physics, Università degli Studi di Napoli Federico II, Piazzale V. Tecchio 80, 80125 Napoli (Italy); Calabria, Raffaela [Istituto Motori-CNR, via G. Marconi 8, 80125 Napoli (Italy); Califano, Valeria, E-mail: v.califano@im.cnr.it [Istituto Motori-CNR, via G. Marconi 8, 80125 Napoli (Italy); Fanelli, Esther [Department of Chemical Engineering, Materials and Industrial Production, Università degli Studi di Napoli Federico II, Piazzale V. Tecchio 80, 80125 Napoli (Italy); Massoli, Patrizio [Istituto Motori-CNR, via G. Marconi 8, 80125 Napoli (Italy); Vicari, Luciano R.M. [CNR-SPIN and Department of Physics, Università degli Studi di Napoli Federico II, Piazzale V. Tecchio 80, 80125 Napoli (Italy)

    2014-11-30

    Highlights: • Lipase from Candida Rugosa was deposited by Matrix Assisted Pulsed Laser Evaporation (MAPLE) on KBr pellets, mica and glass substrate. • The deposited film was characterized morphologically and structurally by optical microscopy, SEM and FTIR analysis. • Results of characterization underlined a phenomenon of aggregation taking place. • The aggregation phenomenon was reversible since lipase showed activity in the transesterification reaction between soybean oil and isopropyl alcohol once detached from the substrate. - Abstract: Lipases (triacylglycerol ester hydrolases) are enzymes used in several industrial applications. Enzymes immobilization can be used to address key issues limiting widespread application at industrial level. Immobilization efficiency is related to the ability to preserve the native conformation of the enzyme. MAPLE (Matrix Assisted Pulsed Laser Evaporation) technique, a laser deposition procedure for treating organic/polymeric/biomaterials, was applied for the deposition of lipase enzyme in an ice matrix, using near infrared laser radiation. Microscopy analysis showed that the deposition occurred in micrometric and submicrometric clusters with a wide size distribution. AFM imaging showed that inter-cluster regions are uniformly covered with smaller aggregates of nanometric size. Fourier transform infrared spectroscopy was used for both recognizing the deposited material and analyzing its secondary structure. Results showed that the protein underwent reversible self-association during the deposition process. Actually, preliminary tests of MAPLE deposited lipase used for soybean oil transesterification with isopropyl alcohol followed by gas chromatography–mass spectrometry gave results consistent with undamaged deposition of lipase.

  2. Low-fluorine Stockwork Molybdenite Deposits

    Science.gov (United States)

    Ludington, Steve; Hammarstrom, Jane; Piatak, Nadine M.

    2009-01-01

    Low-fluorine stockwork molybdenite deposits are closely related to porphyry copper deposits, being similar in their tectonic setting (continental volcanic arc) and the petrology (calc-alkaline) of associated igneous rock types. They are mainly restricted to the Cordillera of western Canada and the northwest United States, and their distribution elsewhere in the world may be limited. The deposits consist of stockwork bodies of molybdenite-bearing quartz veinlets that are present in and around the upper parts of intermediate to felsic intrusions. The deposits are relatively low grade (0.05 to 0.2 percent Mo), but relatively large, commonly >50 million tons. The source plutons for these deposits range from granodiorite to granite in composition; the deposits primarily form in continental margin subduction-related magmatic arcs, often concurrent with formation of nearby porphyry copper deposits. Oxidation of pyrite in unmined deposits or in tailings and waste rock during weathering can lead to development of acid-rock drainage and limonite-rich gossans. Waters associated with low-fluorine stockwork molybdenite deposits tend to be nearly neutral in pH; variable in concentrations of molybdenum (10,000 ug/L); below regulatory guidelines for copper, iron, lead, zinc, and mercury; and locally may exceed guidelines for arsenic, cadmium, and selenium.

  3. Atomic layer deposition of nanoporous biomaterials

    Directory of Open Access Journals (Sweden)

    Roger J Narayan

    2010-03-01

    Full Text Available Due to its chemical stability, uniform pore size, and high pore density, nanoporous alumina is being investigated for use in biosensing, drug delivery, hemodialysis, and other medical applications. In recent work, we have examined the use of atomic layer deposition for coating the surfaces of nanoporous alumina membranes. Zinc oxide coatings were deposited on nanoporous alumina membranes using atomic layer deposition. The zinc oxide-coated nanoporous alumina membranes demonstrated antimicrobial activity against Escherichia coli and Staphylococcus aureus bacteria. These results suggest that atomic layer deposition is an attractive technique for modifying the surfaces of nanoporous alumina membranes and other nanostructured biomaterials.

  4. Origin of Unliberated Bitumen in Athabasca Oil Sands

    Institute of Scientific and Technical Information of China (English)

    TuYun; J.B.O'Carroll; B.D.Sparks; L.S.Kotlyar; S.Ng; K.H.Chung; G.Cuddy

    2005-01-01

    Oil sands contain a so-called organic rich solids component (ORS), i.e., solids whose surfaces are strongly associated with toluene insoluble organic matter (TIOM). Typically, humic material is the major component of TIOM.It provides sites for adsorption and chemical fixation of bitumen. This bound bitumen is """"""""unliberated"""""""", and considerable mechanical or chemical energy may be required to release it. In order to establish a correlation between bitumen recovery and ORS content, a few selected oil sands were processed in a Batch Extraction Unit (BEU).Analysis of the middlings and coarse tailings streams from these tests indicated a relatively constant bitumen to ORS ratio of 2.8±0.7. This value allows the liberated-unliberated bitumen balance (LUBB) to be calculated for any given oil sands. The amounts of bitumen recovered as primary froth during the BEU experiments are close to the estimated liberated bitumen contents in each case tested. This observation indicates that the liberated-unliberated bitumen calculation is an important quantitative parameter for prediction of bitumen recovery under specific recovery conditions. Preliminary results indicate that the ORS content of an oil sands may be estimated from the carbon content of bitumen free oil sands solids.

  5. Characterization of Ultra Fine Solids(BS) in Athabasca Bitumen

    Institute of Scientific and Technical Information of China (English)

    LI Zai-Feng(李再峰); Judy KUNG; TU Yun(涂云); Luba S.KOTLYAR; Keng H.CHUNG

    2004-01-01

    The ultra fine (<200 nm) inorganic solids (BS) were separated from bitumen which was washed by toluene and centrifugated at 2000 rpm.The result of PAS FTIR and image of TEM showed that the structure of BS particles was smiliar to that of kaolinite clay.On the surface of BS,both toluene insoluble organic matter and structural OH group are detected at the same time.The surface characteristics imparted a bi-wettable nature to the BS.As a result,the BS is able to stabilize fine water emulsion in the bitumen phase.The organic matter associated with BS is a possible factor of the fouling on catalyst and equipment.

  6. Hideout in steam generator tube deposits

    International Nuclear Information System (INIS)

    Hideout in deposits on steam generator tubes was studied using tubes coated with magnetite. Hideout from sodium chloride solutions at 279 degrees C was followed using an on-line high-temperature conductivity probe, as well as by chemical analysis of solution samples from the autoclave in which the studies were done. Significant hideout was observed only at a heat flux greater than 200 kW/m2, corresponding to a temperature drop greater than 2 degrees C across the deposits. The concentration factor resulting from the hideout increased highly non-linearly with the heat flux (varying as high as the fourth power of the heat flux). The decrease in the apparent concentration factor with increasing deposit thickness suggested that the pores in the deposit were occupied by a mixture of steam and water, which is consistent with the conclusion from the thermal conductivity measurements on deposits in a separate study. Analyses of the deposits after the hideout tests showed no evidence of any hidden-out solute species, probably due to the concentrations being very near the detection limits and to their escape from the deposit as the tests were being ended. This study showed that hideout in deposits may concentrate solutes in the steam generator bulk water by a factor as high as 2 x 103. Corrosion was evident under the deposit in some tests, with some chromium enrichment on the surface of the tube. Chromium enrichment usually indicates an acidic environment, but the mobility required of chromium to become incorporated into the thick magnetite deposit may indicate corrosion under an alkaline environment. An alkaline environment could result from preferential accumulation of sodium in the solution in the deposit during the hideout process. (author)

  7. Colloid Deposit Morphology and Clogging in Porous Media: Fundamental Insights Through Investigation of Deposit Fractal Dimension.

    Science.gov (United States)

    Roth, Eric J; Gilbert, Benjamin; Mays, David C

    2015-10-20

    Experiments reveal a wide discrepancy between the permeability of porous media containing colloid deposits and the available predictive equations. Evidence suggests that this discrepancy results, in part, from the predictive equations failing to account for colloid deposit morphology. This article reports a series of experiments using static light scattering (SLS) to characterize colloid deposit morphology within refractive index matched (RIM) porous media during flow through a column. Real time measurements of permeability, specific deposit, deposit fractal dimension, and deposit radius of gyration, at different vertical positions, were conducted with initially clean porous media at various ionic strengths and fluid velocities. Decreased permeability (i.e., increased clogging) corresponded with higher specific deposit, lower fractal dimension, and smaller radius of gyration. During deposition, fractal dimension, radius of gyration, and permeability decreased with increasing specific deposit. During flushing with colloid-free fluid, these trends reversed, with increased fractal dimension, radius of gyration, and permeability. These observations suggest a deposition scenario in which large and uniform aggregates become deposits, which reduce porosity, lead to higher fluid shear forces, which then decompose the deposits, filling the pore space with small and dendritic fragments of aggregate.

  8. The mechanical properties of thin alumina film deposited by metal-organic chemical vapour deposition

    NARCIS (Netherlands)

    Haanappel, V.A.C.; Gellings, P.J.; Vendel, van de D.; Metselaar, H.S.C.; Corbach, van H.D.; Fransen, T.

    1995-01-01

    Amorphous alumina films were deposited by metal-organic chemical vapour deposition (MOCVD) on stainless steel, type AISI 304. The MOCVD experiments were performed in nitrogen at low and atmospheric pressures. The effects of deposition temperature, growth rate and film thickness on the mechanical pro

  9. Yangshan Gold Deposit: The Largest Carlin and Carlin-like Type Gold Deposit in China

    Institute of Scientific and Technical Information of China (English)

    YAN Fengzeng; LI Qiangzhi

    2008-01-01

    Gold Headquarter of the CAPF has discovered the Yangshan super large-scale gold depositin Gansu Province, which is a great breakthrough of gold exploration and prospecting in WesternQiniing Mountains of China. The gold resources of this deposit achieved 308 tons with increasingpotentials. Preliminary geological investigations indicate that the Yangshan gold deposit is located inthe intra-continental collision orogenic belt; and the deposit was formed during the continent-continentcollision orogenic processes. The geological characteristics of the deposit are similar to that of thetypical Carlin-type gold deposits, while differences still exist. The ore-forming background is notablydifferent from the Carlin gold deposit province in the United States; and the ore-forming fluids aresimilar with that of the orogenic-type gold deposit. Accordingly, the Yangshan gold deposit is atransitional type between the Carlin-type and the orogenic type gold deposits. At present, the Yangshangold deposit is the largest Carlin and Carlin-like type gold deposit that is ever discovered in China.Researches on metaliogeny, metaliogenic model and ore-enrichment regularities of the Yangshan golddeposit are crucial to meet the pressing needs of the current geological investigation and oreexploration of the deposit.

  10. The geomicrobiology of bauxite deposits

    Institute of Scientific and Technical Information of China (English)

    Xiluo Hao; Kwunlun Leung; Rucheng Wang; Weidong Sun; Yiliang Li

    2010-01-01

    Bauxite deposits are studied because of their economic value and because they play an important role in the study of paleoclimate and paleogeography of continents. They provide a rare record of the weathering and evolution of continental surfaces. Geomicrobiological analysis makes it possible to verify that microorganisms have played a critical role during the formation of bauxite with the possibility already intimated in previous studies. Ambient temperature, abundance of water, organic carbon and bioavailable iron and other metal substrates provide a suitable environment for microbes to inhabit. Thiobacillus, Leptospirilum, Thermophilic bacteria and Heterotrophs have been shown to be able to oxidize ferrous iron and to reduce sulfate-generating sulfuric acid, which can accelerate the weathering of aluminosilicates and precipitation of iron oxyhydroxides. Microorganisms referred to the genus Bacillus can mediate the release of alkaline metals. Although the dissimilatory iron-reducing and sulfate-reducing bacteria in bauxites have not yet been identified, some recorded authigenic carbonates and "bacteriopyrites" that appear to be unique in morphology and grain size might record microbial activity. Typical bauxite minerals such as gibbsite, kaolinite, covellite, galena, pyrite, zircon, calcium ptagioclase, orthoclase, and albite have been investigated as part of an analysis of microbial mediation. The paleoecologyof such bauxitic microorganisms inhabiting continental (sub) surfaces, revealed through geomicrobiological analysis, will add a further dimension to paleoclimatic and paleoenvironmental studies.

  11. 78 FR 16472 - Deposit of Biological Materials

    Science.gov (United States)

    2013-03-15

    ... United States Patent and Trademark Office Deposit of Biological Materials ACTION: Proposed collection....'' SUPPLEMENTARY INFORMATION: I. Abstract The deposit of biological materials as part of a patent application is... use the invention as specified by 35 U.S.C. 112. The term ``biological material'' is defined by 37...

  12. Review of Gaussian diffusion-deposition models

    Energy Technology Data Exchange (ETDEWEB)

    Horst, T.W.

    1979-01-01

    The assumptions and predictions of several Gaussian diffusion-deposition models are compared. A simple correction to the Chamberlain source depletion model is shown to predict ground-level airborne concentrations and dry deposition fluxes in close agreement with the exact solution of Horst.

  13. Atmospheric deposition maps for the Rocky Mountains

    Science.gov (United States)

    Nanus, L.; Campbell, D.H.; Ingersoll, G.P.; Clow, D.W.; Mast, M.A.

    2003-01-01

    Variability in atmospheric deposition across the Rocky Mountains is influenced by elevation, slope, aspect, and precipitation amount and by regional and local sources of air pollution. To improve estimates of deposition in mountainous regions, maps of average annual atmospheric deposition loadings of nitrate, sulfate, and acidity were developed for the Rocky Mountains by using spatial statistics. A parameter-elevation regressions on independent slopes model (PRISM) was incorporated to account for variations in precipitation amount over mountainous regions. Chemical data were obtained from the National Atmospheric Deposition Program/National Trends Network and from annual snowpack surveys conducted by the US Geological Survey and National Park Service, in cooperation with other Federal, State and local agencies. Surface concentration maps were created by ordinary kriging in a geographic information system, using a local trend and mathematical model to estimate the spatial variance. Atmospheric-deposition maps were constructed at 1-km resolution by multiplying surface concentrations from the kriged grid and estimates of precipitation amount from the PRISM model. Maps indicate an increasing spatial trend in concentration and deposition of the modeled constituents, particularly nitrate and sulfate, from north to south throughout the Rocky Mountains and identify hot-spots of atmospheric deposition that result from combined local and regional sources of air pollution. Highest nitrate (2.5-3.0kg/ha N) and sulfate (10.0-12.0kg/ha SO4) deposition is found in northern Colorado.

  14. Plasma Deposition of Doped Amorphous Silicon

    Science.gov (United States)

    Calcote, H. F.

    1985-01-01

    Pair of reports present further experimental details of investigation of plasma deposition of films of phosphorous-doped amosphous silicon. Probe measurements of electrical resistance of deposited films indicated films not uniform. In general, it appeared that resistance decreased with film thickness.

  15. A Simplified Diffusion-Deposition Model

    DEFF Research Database (Denmark)

    Jensen, Niels Otto

    1980-01-01

    The use of a simple top hat plume model facilitates an analytical treatment of the deposition problem. A necessary constraint, however, is that the diffusion velocity (e.g., in terms of the plume growth-rate) is large compared to the deposition velocity. With these limitations, explicit formulae...

  16. Fuzzy Comprehensive Appraisal of Concealed Ore Deposits

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    In this paper, the transformation from the fuzzy to the accurate process is exemplified by the Jiaodong gold ore deposits concentrated region where the mathematical analysis is used to appraise and forecast regional concealed gold ore deposits. In this sense, this paper presents a new way to the appraisal of the non-traditional mineral resources.

  17. Regional aerosol deposition in human upper airways

    Energy Technology Data Exchange (ETDEWEB)

    Swift, D.L.

    1991-11-01

    During the current report experimental studies of upper respiratory deposition of radon progeny aerosols and stimulant aerosols were carried out in replicate casts of nasal and oral passages of adults and children. Additionally, preliminary studies of nasal passage deposition of unattached Po{sup 218} particles was carried out in four human subjects. Data on nasal inspiratory deposition in replicate models of adults and infants from three collaborating laboratories were compared and a best-fit curve of deposition efficiency for both attached and unattached particles was obtained, showing excellent inter-laboratory agreement. This curve demonstrates that nasal inspiratory deposition of radon progeny is weakly dependent upon flow rate over physiologically realistic ranges of flow, does not show a significant age effect, and is relatively independent of nasal passage dimensions for a given age range. Improved replicate models of the human adult oral passage extending to the mid-trachea were constructed for medium and higher flow mouth breathing states; these models were used to assess the deposition of unattached Po{sup 218} particles during oronasal breathing in the oral passage and demonstrated lower deposition efficiency than the nasal passage. Measurements of both Po{sup 218} particle and attached fraction particle size deposition were performed in replicate nasal passage of a four week old infant. 5 refs., 1 fig.

  18. Resource assessment of copper deposits in China

    Institute of Scientific and Technical Information of China (English)

    ZHANG Qin-li; GU De-sheng; T. Shoji; H. Kaneda

    2005-01-01

    Copper-bearing deposits of China are statistically analyzed in terms of ore grade, metal amount and ore tonnage. Each of grade and metal amount shows more or less a lognormal distribution. Analysis gives 10 copper metallogenic districts, each having specific densities of deposit numbers and copper reserves larger than 3. Based on the ratio of copper in ore value (Rcu), Chinese copper deposits are classified into two groups: mainly copper-producing deposits (MC: Rcu≥0.5) and accessorily copper-producing deposits (AC: Rcu<0. 5). The grade-tonnage relation of MC deposits can be combined by two exponential functions approximating high grade (> 3.0 %) and low grade (<2.0%) parts. The critical copper grade, which is obtained from the low grade part of the relation, is 0. 34 %. Chinese copper resources are concluded to become pessimistic, because some mines are working with grades close to this critical value. Taking account of the fact that many copper deposits are actually polymetallic, Cu-equivalent grades, which are converted from ratios of metal prices to the copper price, are also introduced. The critical Cu-equivalent grade of MC deposits (0. 43 % ) also suggests that Chinese copper resources are pessimistic.

  19. 24 CFR 891.775 - Security deposits.

    Science.gov (United States)

    2010-04-01

    ... 24 Housing and Urban Development 4 2010-04-01 2010-04-01 false Security deposits. 891.775 Section 891.775 Housing and Urban Development Regulations Relating to Housing and Urban Development (Continued... Individuals-Section 162 Assistance § 891.775 Security deposits. The general requirements for security...

  20. Large Nonferrous Metals Deposits Found in Yunnan

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    <正>According to the Department of Land and Resources of Yunnan, Yunnan has made great achievements since implementation of the geological prospecting action plan. 5 ultra-large deposits and several large deposits have been found, and a group of key areas with favorable ore-forming prospect have been pinpointed.

  1. 37 CFR 2.208 - Deposit accounts.

    Science.gov (United States)

    2010-07-01

    ... COMMERCE RULES OF PRACTICE IN TRADEMARK CASES Fees and Payment of Money in Trademark Cases § 2.208 Deposit... replenish a deposit account may be submitted by electronic funds transfer through the Federal Reserve... electronic funds transfer over the Office's Internet Web site (www.uspto.gov). (3) A payment to replenish...

  2. Goudafzettingen in Suriname (Gold deposits in Surinam)

    NARCIS (Netherlands)

    Brinck, J.W.

    1956-01-01

    THE GOLD DEPOSITS IN SURINAM AND THE DISTRIBUTION OF CONCESSIONS THROUGH THE COUNTRY The fieldwork on the occurrence of primary and secondary gold deposits in Surinam on which this thesis is based was carried out by order of the Welfare Fund Surinam (Welvaarts Fonds Suriname) during the periods Dece

  3. Assessment of Global Mercury Deposition through Litterfall.

    Science.gov (United States)

    Wang, Xun; Bao, Zhengduo; Lin, Che-Jen; Yuan, Wei; Feng, Xinbin

    2016-08-16

    There is a large uncertainty in the estimate of global dry deposition of atmospheric mercury (Hg). Hg deposition through litterfall represents an important input to terrestrial forest ecosystems via cumulative uptake of atmospheric Hg (most Hg(0)) to foliage. In this study, we estimate the quantity of global Hg deposition through litterfall using statistical modeling (Monte Carlo simulation) of published data sets of litterfall biomass production, tree density, and Hg concentration in litter samples. On the basis of the model results, the global annual Hg deposition through litterfall is estimated to be 1180 ± 710 Mg yr(-1), more than two times greater than the estimate by GEOS-Chem. Spatial distribution of Hg deposition through litterfall suggests that deposition flux decreases spatially from tropical to temperate and boreal regions. Approximately 70% of global Hg(0) dry deposition occurs in the tropical and subtropical regions. A major source of uncertainty in this study is the heterogeneous geospatial distribution of available data. More observational data in regions (Southeast Asia, Africa, and South America) where few data sets exist will greatly improve the accuracy of the current estimate. Given that the quantity of global Hg deposition via litterfall is typically 2-6 times higher than Hg(0) evasion from forest floor, global forest ecosystems represent a strong Hg(0) sink. PMID:27418119

  4. Diamond deposition on thin cylindrical substrates

    Directory of Open Access Journals (Sweden)

    GORDANA S. RISTIĆ

    2011-03-01

    Full Text Available Diamond coatings were deposited onto different cylindrical substrates (Cu, SiC, W and Mo by the hot filament chemical vapor deposition (CVD method. Continuous, adhered and well-faceted crystalline coatings of diamond were obtained on Cu-wire using a special pretreatment with a mixture of diamond and metal powders as well as carefully controlled deposition at lower power. Diamond deposition on SiC-fiber gave continuous and uniform coatings when only the filament power was properly selected. Uniform, homogeneous, euchedral diamond coatings on W- and Mo-wires, attained at a higher filament power, confirmed once more the convenience of refractory metals as substrates for diamond deposition by the CVD technique. Characterization of the obtained coatings was realized using scanning electron microscopy (SEM. The obtained results are compared with the literature data. Differences are discussed with regard to the chemical nature of the substrates as well as their thermophysical characteristics.

  5. A Complexity View of Acid Deposition

    Institute of Scientific and Technical Information of China (English)

    朱建林; 方见树

    2003-01-01

    We show that acid deposition is analogous to complex systems composed of a series of interconnected components.Frequency-size distributions of weekly hydrogen deposition (WHD) of precipitation are consistent with double power-law in two different regimes separated by a crossover WHD. The distribution of variations in acid deposition over a week interval is remarkably symmetrical, with long tail extending over eight orders of magnitude. The acid deposition fluctuations exhibit fractal Brown motion with two different temporal scaling regimes and long-range correlation exists in the series. The power-laws in the acid deposition dynamics are considered to be indicators of seff-organization of atmosphere under environmental pollution stress.

  6. Biosensor Applications of MAPLE Deposited Lipase

    Directory of Open Access Journals (Sweden)

    Valeria Califano

    2014-10-01

    Full Text Available Matrix Assisted Pulsed Laser Evaporation (MAPLE is a thin film deposition technique derived from Pulsed Laser Deposition (PLD for deposition of delicate (polymers, complex biological molecules, etc. materials in undamaged form. The main difference of MAPLE technique with respect to PLD is the target: it is a frozen solution or suspension of the (guest molecules to be deposited in a volatile substance (matrix. Since laser beam energy is mainly absorbed by the matrix, damages to the delicate guest molecules are avoided, or at least reduced. Lipase, an enzyme catalyzing reactions borne by triglycerides, has been used in biosensors for detection of β-hydroxyacid esters and triglycerides in blood serum. Enzymes immobilization on a substrate is therefore required. In this paper we show that it is possible, using MAPLE technique, to deposit lipase on a substrate, as shown by AFM observation, preserving its conformational structure, as shown by FTIR analysis.

  7. Chemical vapor deposition coating for micromachines

    Energy Technology Data Exchange (ETDEWEB)

    MANI,SEETHAMBAL S.; FLEMING,JAMES G.; SNIEGOWSKI,JEFFRY J.; DE BOER,MAARTEN P.; IRWIN,LAWRENCE W.; WALRAVEN,JEREMY A.; TANNER,DANELLE M.; DUGGER,MICHAEL T.

    2000-04-21

    Two major problems associated with Si-based MEMS devices are stiction and wear. Surface modifications are needed to reduce both adhesion and friction in micromechanical structures to solve these problems. In this paper, the authors will present a process used to selectively coat MEMS devices with tungsten using a CVD (Chemical Vapor Deposition) process. The selective W deposition process results in a very conformal coating and can potentially solve both stiction and wear problems confronting MEMS processing. The selective deposition of tungsten is accomplished through silicon reduction of WF{sub 6}, which results in a self-limiting reaction. The selective deposition of W only on polysilicon surfaces prevents electrical shorts. Further, the self-limiting nature of this selective W deposition process ensures the consistency necessary for process control. Selective tungsten is deposited after the removal of the sacrificial oxides to minimize process integration problems. This tungsten coating adheres well and is hard and conducting, requirements for device performance. Furthermore, since the deposited tungsten infiltrates under adhered silicon parts and the volume of W deposited is less than the amount of Si consumed, it appears to be possible to release stuck parts that are contacted over small areas such as dimples. Results from tungsten deposition on MEMS structures with dimples will be presented. The effect of wet and vapor phase cleanings prior to the deposition will be discussed along with other process details. The W coating improved wear by orders of magnitude compared to uncoated parts. Tungsten CVD is used in the integrated-circuit industry, which makes this approach manufacturable.

  8. Sediment-hosted stratabound copper deposit model: Chapter M in Mineral deposit model for resource assessment

    Science.gov (United States)

    Hayes, Timothy S.; Cox, Dennis P.; Bliss, James D.; Piatak, Nadine M.; Seal, Robert R., II

    2015-01-01

    This report contains a descriptive model of sediment-hosted stratabound copper (SSC) deposits that supersedes the model of Cox and others (2003). This model is for use in assessments of mineral resource potential. SSC deposits are the second most important sources of copper in the world behind porphyry copper deposits. Around 20 percent of the copper in the world is produced from this class of deposits. They are also the most important sources of cobalt in the world, and they are fourth among classes of ore deposits in production of silver. SSC deposits are the basis of the economies of three countries: Democratic Republic of Congo, Poland, and Zambia. This report provides a description of the key features of SSC deposits; it identifies their tectonic-sedimentary environments; it illustrates geochemical, geophysical, and geoenvironmental characteristics of SSC deposits; it reviews and evaluates hypotheses on how these deposits formed; it presents exploration and assessment guides; and it lists some gaps in our knowledge about the SSC deposits. A summary follows that provides overviews of many subjects concerning SSC deposits.

  9. Research on depositing Ni45 alloy on titanium alloy surface by electrospark deposition

    Institute of Scientific and Technical Information of China (English)

    You Tao; Zhang Chunhui; Su Guiqiao; Yan Ping

    2008-01-01

    Taking Ni45 bar as electrode, a strengthened layer of thickness up to 50 pm was built up on BT20 titanium alloy matrix by means of electrospark deposition. Results of phase analysis by using of X-ray diffraction confirmed that the deposition layer was composed mostly of three phases, NiTi, NiTi2layer was up to 910 HV0.05, about 2.7 times as high as that of the matrix. The hardness at the cross-section of the entire deposition layer showed a gradient distribution. The effects of capacitance and deposition time on thickness of deposition layer were also studied, and results showed that with relatively low capacity and short deposition time the deposition layer without cracks can be obtained.

  10. Reducing tube bundle deposition using alternative amines

    International Nuclear Information System (INIS)

    Particle deposition rates were measured in a high-temperature loop for magnetite and hematite depositing onto Inconel-600 under flow-boiling conditions with pH controlled, using one of the following amines: morpholine, ammonia, ethanolamine, or dimethylamine. Hematite particles deposited at rates 10 times greater than those measured for magnetite although the hematite deposition rate dropped when the loop was operated under reducing conditions. The magnetite deposition rate was influenced by the amine used to control the pH, with the relative rate decreasing in the following series: morpholine (1) : ethanolamine (0.72) : ammonia (0.51) dimethylamine (0.25). These trends in deposition rate are discussed in terms of the surface chemistry of the corrosion products. Deposition rates for both magnetite and hematite increased significantly once the mixture quality exceeded about 0.3, which may be related to a change in the heat-transfer mechanism from nucleate boiling to 2-phase forced-convection through a thin film. (author)

  11. Deposition of large particles in human lung

    International Nuclear Information System (INIS)

    Twenty-four nonsmoking males, all without history of pulmonary disease, were randomly divided into four groups of six subjects each. The subjects in each group inhaled monodisperse Teflon particles labelled with 111In (half-life 2.83 days); 8.2, 11.5, 13.7 and 16.4 micron aerodynamic diameter, respectively. Radioactivity in head and throat, lung and stomach was determined after 0, 3 and 24 hrs using a profile scanner. For some subjects radioactivity was also determined using a whole-body scanner at 3.5 and 24 hrs. After the 24-hr determination the subjects inhaled labelled Teflon particles again, this time with a filter in front of the mouth. Average values for total deposition in the body, obtained using a profile scanner, whole-body scanner and filter measurements, agreed fairly well. Lung retention values obtained by whole-body and profile scanning also agreed well. The average deposition in the lung, expressed as a percentage of total deposition, was 49, 31, 21 and 13% for the four particle sizes (8.2-16.4 micron). Alveolar deposition, determined as retention at 24 hrs and expressed in percent of total deposition, was 15, 4, 4 and 1%. For the smallest particle sizes the deposition values agreed with earlier investigations. However, for the larger particles the two deposition values were higher than expected when compared to earlier studies

  12. Deposition of large particles in human lung.

    Science.gov (United States)

    Svartengren, M; Falk, R; Linnman, L; Philipson, K; Camner, P

    1987-01-01

    Twenty-four nonsmoking males, all without history of pulmonary disease, were randomly divided into four groups of six subjects each. The subjects in each group inhaled monodisperse Teflon particles labelled with 111In (half-life 2.83 days); 8.2, 11.5, 13.7 and 16.4 micron aerodynamic diameter, respectively. Radioactivity in head and throat, lung and stomach was determined after 0, 3 and 24 hrs using a profile scanner. For some subjects radioactivity was also determined using a whole-body scanner at 3.5 and 24 hrs. After the 24-hr determination the subjects inhaled labelled Teflon particles again, this time with a filter in front of the mouth. Average values for total deposition in the body, obtained using a profile scanner, whole-body scanner and filter measurements, agreed fairly well. Lung retention values obtained by whole-body and profile scanning also agreed well. The average deposition in the lung, expressed as a percentage of total deposition, was 49, 31, 21 and 13% for the four particle sizes (8.2-16.4 micron). Alveolar deposition, determined as retention at 24 hrs and expressed in percent of total deposition, was 15, 4, 4 and 1%. For the smallest particle sizes the deposition values agreed with earlier investigations. However, for the larger particles the two deposition values were higher than expected when compared to earlier studies. PMID:3102217

  13. Deposition of large particles in human lung

    Energy Technology Data Exchange (ETDEWEB)

    Svartengren, M.; Falk, R.; Linnman, L.; Philipson, K.; Camner, P.

    1987-01-01

    Twenty-four nonsmoking males, all without history of pulmonary disease, were randomly divided into four groups of six subjects each. The subjects in each group inhaled monodisperse Teflon particles labelled with /sup 111/In (half-life 2.83 days); 8.2, 11.5, 13.7 and 16.4 micron aerodynamic diameter, respectively. Radioactivity in head and throat, lung and stomach was determined after 0, 3 and 24 hrs using a profile scanner. For some subjects radioactivity was also determined using a whole-body scanner at 3.5 and 24 hrs. After the 24-hr determination the subjects inhaled labelled Teflon particles again, this time with a filter in front of the mouth. Average values for total deposition in the body, obtained using a profile scanner, whole-body scanner and filter measurements, agreed fairly well. Lung retention values obtained by whole-body and profile scanning also agreed well. The average deposition in the lung, expressed as a percentage of total deposition, was 49, 31, 21 and 13% for the four particle sizes (8.2-16.4 micron). Alveolar deposition, determined as retention at 24 hrs and expressed in percent of total deposition, was 15, 4, 4 and 1%. For the smallest particle sizes the deposition values agreed with earlier investigations. However, for the larger particles the two deposition values were higher than expected when compared to earlier studies.

  14. Structural characterization of MAPLE deposited lipase biofilm

    Science.gov (United States)

    Aronne, Antonio; Ausanio, Giovanni; Bloisi, Francesco; Calabria, Raffaela; Califano, Valeria; Fanelli, Esther; Massoli, Patrizio; Vicari, Luciano R. M.

    2014-11-01

    Lipases (triacylglycerol ester hydrolases) are enzymes used in several industrial applications. Enzymes immobilization can be used to address key issues limiting widespread application at industrial level. Immobilization efficiency is related to the ability to preserve the native conformation of the enzyme. MAPLE (Matrix Assisted Pulsed Laser Evaporation) technique, a laser deposition procedure for treating organic/polymeric/biomaterials, was applied for the deposition of lipase enzyme in an ice matrix, using near infrared laser radiation. Microscopy analysis showed that the deposition occurred in micrometric and submicrometric clusters with a wide size distribution. AFM imaging showed that inter-cluster regions are uniformly covered with smaller aggregates of nanometric size. Fourier transform infrared spectroscopy was used for both recognizing the deposited material and analyzing its secondary structure. Results showed that the protein underwent reversible self-association during the deposition process. Actually, preliminary tests of MAPLE deposited lipase used for soybean oil transesterification with isopropyl alcohol followed by gas chromatography-mass spectrometry gave results consistent with undamaged deposition of lipase.

  15. Reducing tube bundle deposition with alternative amines

    International Nuclear Information System (INIS)

    Particle deposition rates have been measured in a high-temperature loop for magnetite and hematite depositing onto Inconel-600 under flow-boiling conditions with pH controlled using one of the following amines: morpholine, ammonia, ethanolamine, or dimethylamine. Hematite particles deposited at rates an order of magnitude greater than those measured for magnetite, although the hematite deposition rate dropped when the loop was operated under reducing conditions. The magnetite deposition rate was influenced by the amine used to control the pH, with the relative rate decreasing in the following series: morpholine (1) : ethanolamine (0.72) ammonia (0.51) : dimethylamine (0.25). These trends in deposition rate are discussed in terms of the surface chemistry of the corrosion products. Deposition rates for both magnetite and hematite increased significantly once the mixture quality exceeded about 0.3, which may be related to a change in the heat transfer mechanism from nucleate boiling to two-phase forced convection through a thin film. (author)

  16. Depositional process for the Triassic-Jurassic stratiform manganese deposits in the Chichibu Belt, Southwest Japan.

    Science.gov (United States)

    Tomimatsu, Y.; Onoue, T.

    2015-12-01

    The chert-hosted manganese deposits have been known to occur in the Triassic to Jurassic chert or chert-greenstone complex within a Jurassic accretionary complex in Japan. In order to reveal the origin of these manganese deposits, we investigated the stratigraphy, age and geochemistry of manganese deposits from the Triassic to Jurassic bedded chert succession of the Chichibu Belt, defined as a Jurassic subduction-generated accretionary complex in Southwest Japan. The Triassic to Jurassic bedded cherts in the Chichibu Belt are considered to be deep-sea sediments that accumulated in an open-ocean realm of the Panthalassa Ocean. Our biostratigraphic analysis of radiolarians reveals that the stratiform manganese deposits intercalated in the bedded cherts were deposited in the Late Triassic and Early Jurassic. Upper Triassic manganese deposit occurs associated with the massive cherts which appear to have been formed by hydrothermal activity. The red bedded chert above the manganese deposit yields radiolarian fossils, including Trialatus longicornutus and Poulpus carcharus. These radiolarians indicate that age of manganese deposits can be correlated with the late Carnian age. Lower Jurassic manganese deposit occurs intercalated within the gray to dark gray bedded cherts. Detailed biostratigraphic analysis of radiolarians reveals that manganese deposit is embedded in the upper Pliensbachian to Toarcian (Trillus elkhornensis Zone). Chemical compositions of Upper Triassic deposits are characterized by enrichments in Mn and depletion of Co, Ni and Zn. These geochemical features are similar to those of modern submarine hydrothermal manganese deposits from hydrothermal activity. In contrast, lower Jurassic manganese deposits were triggered by an influx of warm, saline and oxic water into a stagnant deep ocean floor basin. It is likely that the deposits are considered to have formed by oceanic anoxic event.

  17. 24 CFR 886.315 - Security and utility deposits.

    Science.gov (United States)

    2010-04-01

    ... 24 Housing and Urban Development 4 2010-04-01 2010-04-01 false Security and utility deposits. 886... utility deposits. (a) Amount of deposits. If at the time of the initial execution of the Lease the Owner... security deposits and utility deposits from its resources and/or other public or private sources. (b)...

  18. Wet deposition in the northeastern United States

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, J; Mohnen, V; Kadlecek, J

    1980-12-01

    Attempts are made to examine concentration and wet deposition of pollutant material at selected stations within the northeastern United States and to characterize as many events as possible with respect to air mass origin. Further attempts are made to develop a regional pattern for the deposition of dominant ion species. MAP3S (US Multistate Atmospheric Power Production Pollution Study) data for 1977 to 1979 are used to determine concentration and deposition on an event basis from which monthly, seasonal, annual, and cumulative averages are developed. The ARL-ATAD trajectory model is used to characterize individual events as to air mass origin. Case studies are examined to illustrate variability in the chemical composition of precipitation originating from distinctly different air mass trajectories. A difference in concentration of pollution-related ions in precipitation is noted between Midwest/Ohio Valley and Great Lakes/Canadian air mass origins for carefully selected cases. Total deposition of the major ions is examined in an effort to develop a regional pattern for deposition over a period of at least one year. For that purpose, total deposition is normalized to remove the variability in precipitation amounts for inter-station comparison. No marked gradient is noted in the normalized deposition totals within the northeast of the United States. The Adirondack region exhibited the lowest normalized ion deposition value, while the Illinois station showed the highest of the MAP3S network. The data analysis suggest that the acid rain phenomena covers the entire northeast. The concept of large scale mixing emerges to account for the lack of a significant gradient in the normalized deposition.

  19. TEOS-based oxides: deposition dependent properties

    International Nuclear Information System (INIS)

    This paper reports the effects of three important parameters, deposition temperature, TEOS concentration and RF power in the plasma enhanced CVD of TEOS-based oxides on the resulting film characteristics such as impurity incorporation, film density, moisture absorption, intrinsic and thermal stresses. Ion-bombardment induced desorption of reactive precursor species is suggested to occur under certain conditions. Further, it is shown that the film properties continue to evolve until the film thickness exceeds 3000A. For 1 μm films deposited using typical settings of deposition parameters, the average TCE is estimated to be 0.9 ppm/ C using the stress-temperature characteristics. (orig.)

  20. Characteristics that distinguish types of epithermal deposits

    Science.gov (United States)

    Hayba, D.O.; Foley, N.K.; Heald-Wetlaufer, P.

    1984-01-01

    Three distinctive groupings of epithermal deposits were recognized from a literature study of fifteen well-described precious- and base-metal epithermal districts, supplemented by L. J. Buchanan's 1981 compilation of data from 47 less completely documented deposits. The three groups are distinguished primarily by the type of alteration and the sulfur fugacity indicated by the vein mineral assemblage. Additional discriminating criteria include composition of the host rock, timing of ore deposition relative to emplacement of the host, and relative abundances of gold, silver, and base metals.

  1. Bilateral Pseudoexfoliation Deposits on Intraocular Lens Implants

    Directory of Open Access Journals (Sweden)

    Elena Bonafonte Marquez

    2015-01-01

    Full Text Available We present a rare case of bilateral pseudoexfoliative deposits on both intraocular lens (IOL implants in an 83-year-old woman with no other associated pathology, 5 years after cataract surgery. Pseudoexfoliation syndrome is the most common cause of secondary open-angle glaucoma worldwide and these deposits are usually found on the natural lens. The fact that pseudoexfoliative deposits have been found on IOL implants implies the need for a thorough examination in pseudophakic patients, for it could be the only sign of secondary glaucoma.

  2. Deposition of contaminant aerosol on human skin

    DEFF Research Database (Denmark)

    Andersson, Kasper Grann; Roed, Jørn; Byrne, M.A.;

    2006-01-01

    Over recent years, it has been established that deposition of various types of pollutant aerosols (e.g., radioactive) on human skin can have serious deleterious effects on health. However. only few investigations in the past have been devoted to measurement of deposition velocities on skin...... to this variation. Part of the variation was found to be caused by differences between individuals, whereas another part was found to be related to environmental factors, The identification of major influences on skin contaminant deposition is important in estimating health effects as well as in identifying means...

  3. Thermodynamic analysis and deposition of refractory materials

    International Nuclear Information System (INIS)

    This article does not pretend to be an exhaustive review of all publications in which a thermodynamic analysis has been used to analyse the chemical vapour deposition of refractory materials. It simply covers a certain number of experiments in which the present authors made use of various aspects of this method: overall or partial optimization of a process, determination of the deposition material most suited to fulfilling a given role and approach to mechanisms governing the chemical deposition reaction. A thermodynamic analysis is presented here from a more unusual angle, by examples of localized and varied intervention, in order to demonstrate the multiple uses of the method. (orig.)

  4. Adhesion Strength of Biomass Ash Deposits

    DEFF Research Database (Denmark)

    Laxminarayan, Yashasvi; Jensen, Peter Arendt; Wu, Hao;

    2015-01-01

    This study investigates the shear adhesion strength of biomass ash deposits on superheater tubes. Artificial biomass ash deposits were prepared on superheater tubes and sintered in an oven at temperatures up to 1000°C. Subsequently, the deposits were sheared off with the help of an electrically...... controlled arm. Higher sintering temperatures resulted in greater adhesion strengths, with a sharp increase observed near the melting point of the ash. Repetition of experiments with fixed operation conditions revealed considerable variation in the obtained adhesion strengths, portraying the stochastic...

  5. Magnetoresistive multilayers deposited on the AAO membranes

    Energy Technology Data Exchange (ETDEWEB)

    Malkinski, Leszek M. [Advanced Materials Research Institute, University of New Orleans, 2000 Lakeshore Drive, New Orleans, LA 70148 (United States)]. E-mail: lmalkins@uno.edu; Chalastaras, Athanasios [Advanced Materials Research Institute, University of New Orleans, 2000 Lakeshore Drive, New Orleans, LA 70148 (United States); Vovk, Andriy [Advanced Materials Research Institute, University of New Orleans, 2000 Lakeshore Drive, New Orleans, LA 70148 (United States); Jung, Jin-Seung [Department of Chemistry, Kangnung National University, Kangnung 210702 (Korea, Republic of) ; Kim, Eun-Mee [Department of Chemistry, Kangnung National University, Kangnung 210702 (Korea, Republic of) ; Jun, Jong-Ho [Department of Applied Chemistry, Kunkuk University, Chungju 151747 (Korea, Republic of) ; Ventrice, Carl A. [Advanced Materials Research Institute, University of New Orleans, 2000 Lakeshore Drive, New Orleans, LA 70148 (United States)

    2005-02-01

    Silicon and GaAs wafers are the most commonly used substrates for deposition of giant magnetoresistive (GMR) multilayers. We explored a new type of a substrate, prepared electrochemically by anodization of aluminum sheets, for deposition of GMR multilayers. The surface of this AAO substrate consists of nanosized hemispheres organized in a regular hexagonal array. The current applied along the substrate surface intersects many magnetic layers in the multilayered structure, which results in enhancement of giant magnetoresistance effect. The GMR effect in uncoupled Co/Cu multilayers was significantly larger than the magnetoresistance of similar structures deposited on Si.

  6. Platinum-ruthenium bimetallic clusters on graphite: a comparison of vapor deposition and electroless deposition methods.

    Science.gov (United States)

    Galhenage, Randima P; Xie, Kangmin; Diao, Weijian; Tengco, John Meynard M; Seuser, Grant S; Monnier, John R; Chen, Donna A

    2015-11-14

    Bimetallic Pt-Ru clusters have been grown on highly ordered pyrolytic graphite (HOPG) surfaces by vapor deposition and by electroless deposition. These studies help to bridge the material gap between well-characterized vapor deposited clusters and electrolessly deposited clusters, which are better suited for industrial catalyst preparation. In the vapor deposition experiments, bimetallic clusters were formed by the sequential deposition of Pt on Ru or Ru on Pt. Seed clusters of the first metal were grown on HOPG surfaces that were sputtered with Ar(+) to introduce defects, which act as nucleation sites for Pt or Ru. On the unmodified HOPG surface, both Pt and Ru clusters preferentially nucleated at the step edges, whereas on the sputtered surface, clusters with relatively uniform sizes and spatial distributions were formed. Low energy ion scattering experiments showed that the surface compositions of the bimetallic clusters are Pt-rich, regardless of the order of deposition, indicating that the interdiffusion of metals within the clusters is facile at room temperature. Bimetallic clusters on sputtered HOPG were prepared by the electroless deposition of Pt on Ru seed clusters from a Pt(+2) solution using dimethylamine borane as the reducing agent at pH 11 and 40 °C. After exposure to the electroless deposition bath, Pt was selectively deposited on Ru, as demonstrated by the detection of Pt on the surface by XPS, and the increase in the average cluster height without an increase in the number of clusters, indicating that Pt atoms are incorporated into the Ru seed clusters. Electroless deposition of Ru on Pt seed clusters was also achieved, but it should be noted that this deposition method is extremely sensitive to the presence of other metal ions in solution that have a higher reduction potential than the metal ion targeted for deposition. PMID:26018140

  7. NOAA/WDC Global Tsunami Deposits Database

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Discover where, when and how severely tsunamis affected Earth in geologic history. Information regarding Tsunami Deposits and Proxies for Tsunami Events complements...

  8. ROE Total Nitrogen Deposition 1989-1991

    Data.gov (United States)

    U.S. Environmental Protection Agency — This dataset identifies the amount of wet, dry, and total deposition of nitrogen in kilograms per hectare from 1989 to 1991 at a set of point locations across the...

  9. ROE Wet Sulfate Deposition 2009-2011

    Data.gov (United States)

    U.S. Environmental Protection Agency — The raster data represent the amount of wet sulfate deposition in kilograms per hectare from 2009 to 2011. Summary data in this indicator were provided by EPA’s...

  10. ROE Wet Nitrate Deposition 1989-1991

    Data.gov (United States)

    U.S. Environmental Protection Agency — The raster data represent the amount of wet nitrate deposition in kilograms per hectare from 1989 to 1991. Summary data in this indicator were provided by EPA’s...

  11. ROE Total Sulfur Deposition 1989-1991

    Data.gov (United States)

    U.S. Environmental Protection Agency — This dataset identifies the amount of wet, dry, and total deposition of sulfur in kilograms per hectare from 1989 to 1991 at a set of point locations across the...

  12. ROE Wet Nitrate Deposition 2011-2013

    Data.gov (United States)

    U.S. Environmental Protection Agency — The raster data represent the amount of wet nitrate deposition in kilograms per hectare from 2011 to 2013. Summary data in this indicator were provided by EPA’s...

  13. ROE Total Nitrogen Deposition 2011-2013

    Data.gov (United States)

    U.S. Environmental Protection Agency — This dataset identifies the amount of wet, dry, and total deposition of nitrogen in kilograms per hectare from 2011 to 2013 at a set of point locations across the...

  14. ROE Total Sulfur Deposition 2011-2013

    Data.gov (United States)

    U.S. Environmental Protection Agency — This dataset identifies the amount of wet, dry, and total deposition of sulfur in kilograms per hectare from 2011 to 2013 at a set of point locations across the...

  15. Rare earth element mines, deposits, and occurrences

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This dataset contains location, geologic and mineral economic data for world rare earth mines, deposits, and occurrences. The data in this compilation were derived...

  16. Tax Evasion and Swiss Bank Deposits

    DEFF Research Database (Denmark)

    Johannesen, Niels

    Bank deposits in jurisdictions with banking secrecy constitute an effective tool to evade taxes on interest income. A recent EU reform reduces the scope for this type of tax evasion by introducing a source tax on interest income earned by EU residents in Switzerland and several other jurisdictions...... with banking secrecy. In this paper, we estimate the impact of the source tax on Swiss bank deposits held by EU residents while using that non-EU residents were not subject to the tax to apply a natural experiment methodology. We find that the 15% source tax caused Swiss bank deposits of EU residents to drop...... by more than 40% with most of the response occurring in two quarters immediately before and after the source tax was introduced. The estimates imply an elasticity of Swiss deposits with respect to the net-of-source-tax-rate in the range 2.5-3....

  17. The neutron characteristics of coal deposits

    International Nuclear Information System (INIS)

    The neutron parameters of coal vs. its hydrogen content are calculated. The strong dependences observed point the possibilities of neutron analytical methods for determining hydrogen content in coal deposits. (author)

  18. Porphyry copper deposits of the world

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Information on porphyry copper deposits from around the world with grade and tonnage models, a general classification based on geologic setting, mineralogy, with...

  19. Major mineral deposits of the world

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Regional locations and general geologic setting of known deposits of major nonfuel mineral commodities. Originally compiled in five parts by diverse authors,...

  20. Making Lightweight Structures By Vapor Deposition

    Science.gov (United States)

    Goela, Jitendra S.; Pickering, Michael A.; Taylor, Raymond L.

    1990-01-01

    Technique developed for fabrication of stiff, strong, lightweight structures of silicon carbide or other materials by any of several deposition processes. Structures made by method can have complicated shapes. Ability to manufacture complex shape from pure deposited SiC useful and leads to new products in several fields. These lightweight structures used as backup structures for optical components, as structural components in automotive, aerospace, and outer space applications, and as lightweight parts of furniture for outer space.

  1. Ultramafic-Hosted Talc-Magnesite Deposits

    Science.gov (United States)

    Robinson,, Gilpin R.; Van Gosen, Bradley S.; Foley, Nora K.

    2006-01-01

    This presentation on the geology of ultramafic-hosted talc-magnesite deposits was given at the 42nd Forum on the Geology of Industrial Minerals, May 7-13, 2006, in Asheville, North Carolina (USA). Talc is a soft inert industrial mineral commodity commonly used as a component or filler in ceramic, paint, paper, plastic, roofing, and electrical applications. Ultramafic-hosted talc-magnesite deposits are important sources of talc.

  2. Modelling The Dynamic Distribution Of Spray Deposits

    OpenAIRE

    Lebeau, Frédéric

    2004-01-01

    A mathematical model to estimate the spray distribution of phytopharmaceutical deposits under a spray boom is proposed. It focuses on the need to take account of the dynamic effects of the forward movement of the boom. These are related both to the horizontal and vertical boom movement and to the influence of aerodynamic factors on the nozzle spray distribution. The distribution of the spray deposits is computed by multiplying the nozzle spray pattern by the time needed to m...

  3. A Game Theory Approach of Deposit Insurance

    Institute of Scientific and Technical Information of China (English)

    JIANG Hong-xun; QIU Wan-hua; MING Ming

    2002-01-01

    This paper presents a dynamic game theory approach for deposit insurance. We formulate a deposit insurance problem as an incomplete information game theory model, which deduces the expression of Capital Charge Ratio for national central bank. The main contribution of the paper however is that we then extrapolate the declared value of the bank in best its policy. Finally a numerical example is used to illustrate the approach proposed in this paper.

  4. An Introduction to Copper Deposits in China

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    There are 11 genetic types of copper deposit in China, three of which (porphyry,contact metasomatic and VMS types) are the most important. The copper deposits distribute widely both temporally and spatially in China. The features of copper ores in China are mostly poor in copper tenor and complex in metal associated. The copper metallogeny in China predominantly occurs in three metallogenic megadomains, namely the circum-Pacific, the paleo-Asian and the Tethys-Himalayan.

  5. IMMUNOGLOBULIN DEPOSITIONS IN PERIPHERAL NERVES IN POLYMYOSITIS

    Institute of Scientific and Technical Information of China (English)

    李越星; 陈清棠; 吴丽娟; 贾钟; 张秋荣; 左越焕

    1995-01-01

    An immunocytochemical study was performed in 6 peripheral nerve specimens from 6 cases of polymyositis.The results revealed that depositions of IgG,IgM,IgA and C3 were found in the epineurium,perineurium and the walls of capillaries.These findings demonstrated that depositions of immonoglobulins and the complement-mediated immunoreaction may play an important role in pathogenesis of polymyositis with peripheral nerfve involvements.

  6. Major Brazilian gold deposits - 1982 to 1999

    Science.gov (United States)

    Thorman, Charles H.; DeWitt, Ed; Maron, Marcos A.; Ladeira, Eduardo A.

    2001-07-01

    Brazil has been a major but intermittent producer of gold since its discovery in 1500. Brazil led the world in gold production during the 18th and early 19th centuries. From the late 19th century to the late 20th century, total mining company and garimpeiro production was small and relatively constant at about 5 to 8 t/year. The discovery of alluvial deposits in the Amazon by garimpeiros in the 1970s and the opening of eight mines by mining companies from 1983 to 1990 fueled a major boom in Brazil's gold production, exceeding 100 t/year in 1988 and 1989. However, garimpeiro alluvial production decreased rapidly in the 1990s, to about 10 t/year by 1999. Company production increased about tenfold from about 4 t/year in 1982 to 40 t in 1992. Production from 1992 to the present remained relatively stable, even though several mines were closed or were in the process of closing and no new major mines were put into production during that period. Based on their production history from 1982-1999, 17 gold mines are ranked as major (>20 t) and minor (3-8 t) mines. From 1982-1999, deposits hosted in Archean rocks produced 66% of the gold in Brazil, whereas deposits in Paleoproterozoic and Neoproterozoic rocks accounted for 19% and 15%, respectively. Deposits in metamorphosed sedimentary rocks, especially carbonate-rich rocks and carbonate iron-formation, yielded the great bulk of the gold. Deposits in igneous rocks were of much less importance. The Archean and Paleoproterozoic terranes of Brazil largely lack base-metal-rich volcanogenic massive sulfide deposits, porphyry deposits, and polymetallic veins and sedimentary exhalative deposits. An exception to this is in the Carajás Mineral Province.

  7. Removal of External Deposits on Boiler Tubes

    Directory of Open Access Journals (Sweden)

    C. P. De

    1970-07-01

    Full Text Available The superheater tubes in Port and Starboard boilers were found to have completely clogged by heavy deposits, which on analysis mainly vanadium pentoxide and sodium sulphmatter. The cleaning of the deposits was accomplished by alternate spraying with 15-20 per cent hydrogen peroxide and washing with hot water jets. Over the past two years, since the date of cleaning, the IN ship is operating without any trouble in the boilers.

  8. Fabrication of Micro Components by Electrochemical Deposition

    DEFF Research Database (Denmark)

    Tang, Peter Torben

    The main issue of this thesis is the combination of electrochemical deposition of metals and micro machining. Processes for electroplating and electroless plating of nickel and nickel alloys have been developed and optimised for compatibility with microelectronics and silicon based micromechanics...... of electrochemical machining and traditional machining is compared to micro machining techniques as performed in the field of microelectronics. Various practical solutions and equipment for electrochemical deposition of micro components are demonstrated, as well as the use and experience obtained utilising...

  9. Study on pulsed excimer laser deposited films

    CERN Document Server

    Liu Jing Ru; Li Tie Jun; Yao Dong Sheng; Wang Li Ge; Yuan Xiao; Wang Sheng; Ye Xi Sheng

    2002-01-01

    Pulsed lasers of two different durations (30 ns, 500 fs) are used to deposit Hydrogen-free Diamond Like Carbon (DLC) films over large areas. Analysis of DLC films shows remarkable mechanical, optical, electrical, and chemical properties that are close to those of diamond. By optical emission spectroscopy and ion probe, the effects of plasma characteristic on DLC film are on experimentally studied. Amorphous silicon films deposited by PLD are also experimentally studied

  10. Semiconductor assisted metal deposition for nanolithography applications

    Science.gov (United States)

    Rajh, Tijana; Meshkov, Natalia; Nedelijkovic, Jovan M.; Skubal, Laura R.; Tiede, David M.; Thurnauer, Marion

    2001-01-01

    An article of manufacture and method of forming nanoparticle sized material components. A semiconductor oxide substrate includes nanoparticles of semiconductor oxide. A modifier is deposited onto the nanoparticles, and a source of metal ions are deposited in association with the semiconductor and the modifier, the modifier enabling electronic hole scavenging and chelation of the metal ions. The metal ions and modifier are illuminated to cause reduction of the metal ions to metal onto the semiconductor nanoparticles.

  11. Selective Electroless Silver Deposition on Graphene Edges

    DEFF Research Database (Denmark)

    Durhuus, D.; Larsen, M. V.; Andryieuski, Andrei;

    2015-01-01

    We demonstrate a method of electroless selective silver deposition on graphene edges or between graphene islands without covering the surface of graphene. Modifications of the deposition recipe allow for decoration of graphene edges with silver nanoparticles or filling holes in damaged graphene...... on silica substrate and thus potentially restoring electric connectivity with minimal influence on the overall graphene electrical and optical properties. The presented technique could find applications in graphene based transparent conductors as well as selective edge functionalization and can be extended...

  12. Perovskite thin films via atomic layer deposition.

    Science.gov (United States)

    Sutherland, Brandon R; Hoogland, Sjoerd; Adachi, Michael M; Kanjanaboos, Pongsakorn; Wong, Chris T O; McDowell, Jeffrey J; Xu, Jixian; Voznyy, Oleksandr; Ning, Zhijun; Houtepen, Arjan J; Sargent, Edward H

    2015-01-01

    A new method to deposit perovskite thin films that benefit from the thickness control and conformality of atomic layer deposition (ALD) is detailed. A seed layer of ALD PbS is place-exchanged with PbI2 and subsequently CH3 NH3 PbI3 perovskite. These films show promising optical properties, with gain coefficients of 3200 ± 830 cm(-1) .

  13. Perovskite Thin Films via Atomic Layer Deposition

    KAUST Repository

    Sutherland, Brandon R.

    2014-10-30

    © 2014 Wiley-VCH Verlag GmbH & Co. KGaA. (Graph Presented) A new method to deposit perovskite thin films that benefit from the thickness control and conformality of atomic layer deposition (ALD) is detailed. A seed layer of ALD PbS is place-exchanged with PbI2 and subsequently CH3NH3PbI3 perovskite. These films show promising optical properties, with gain coefficients of 3200 ± 830 cm-1.

  14. Sediment-Hosted Copper Deposits of the World: Deposit Models and Database

    Science.gov (United States)

    Cox, Dennis P.; Lindsey, David A.; Singer, Donald A.; Diggles, Michael F.

    2003-01-01

    Introduction This publication contains four descriptive models and four grade-tonnage models for sediment hosted copper deposits. Descriptive models are useful in exploration planning and resource assessment because they enable the user to identify deposits in the field and to identify areas on geologic and geophysical maps where deposits could occur. Grade and tonnage models are used in resource assessment to predict the likelihood of different combinations of grades and tonnages that could occur in undiscovered deposits in a specific area. They are also useful in exploration in deciding what deposit types meet the economic objectives of the exploration company. The models in this report supersede the sediment-hosted copper models in USGS Bulletin 1693 (Cox, 1986, and Mosier and others, 1986) and are subdivided into a general type and three subtypes. The general model is useful in classifying deposits whose features are obscured by metamorphism or are otherwise poorly described, and for assessing regions in which the geologic environments are poorly understood. The three subtypes are based on differences in deposit form and environments of deposition. These differences are described under subtypes in the general model. Deposit models are based on the descriptions of geologic environments and physical characteristics, and on metal grades and tonnages of many individual deposits. Data used in this study are presented in a database representing 785 deposits in nine continents. This database was derived partly from data published by Kirkham and others (1994) and from new information in recent publications. To facilitate the construction of grade and tonnage models, the information, presented by Kirkham in disaggregated form, was brought together to provide a single grade and a single tonnage for each deposit. Throughout the report individual deposits are defined as being more than 2,000 meters from the nearest adjacent deposit. The deposit models are presented here as

  15. Quantitative analysis of diamond deposition reactor efficiency

    International Nuclear Information System (INIS)

    Graphical abstract: Surface H atom densities in a diamond deposition plasma reactor and the highest predicted value (black line). A 350 μm diamond crystal grown at 70 μm/h. Highlights: ► Electron temperature measurement at high pressure in diamond deposition reactor. ► H-atom density measurements at high pressure and high power in diamond deposition reactor. ► Surface H-atom density measurements at high pressure and high power in diamond deposition reactor. ► Microwave cavity based reactor efficiency compared to others reactors. - Abstract: Optical emission spectroscopy has been used to characterize diamond deposition microwave chemical vapour deposition (MWCVD) plasmas operating at high power density. Electron temperature has been deduced from H atom emission lines while H-atom mole fraction variations have been estimated using actinometry technique, for a wide range of working conditions: pressure 25–400 hPa and MW power 600–4000 W. An increase of the pressure from 14 hPa to 400 hPa with a simultaneous increase in power causes an electron temperature decrease from 17,000 K to 10,000 K and a H atom mole fraction increase from 0.1 to up to 0.6. This last value however must be considered as an upper estimate due to some assumptions made as well as experimental uncertainties.

  16. Modeling sediment deposition from marine outfall jets.

    Science.gov (United States)

    Terfous, Abdelali; Chiban, Samia; Ghenaim, Abdellah

    2016-08-01

    This paper presents a two-dimensional model to study the sediment deposition from marine outfall jets. The introduced unidirectional coupling (fluid-sediment) is an appropriate choice in the case of low-concentrated particle-laden jets such as municipal wastewater discharge, where the concentration of particles is small enough and does not affect the hydrodynamic development of the jet in the nearfield. The sedimentation model takes advantage of the preferential concentration phenomenon. The deposition criterion states that the deposition of sediments begins when the vertical component of the entrainment velocity becomes smaller than the settling velocity. Once the deposition process begins, it is controlled by the settling velocity, entrainment velocity, volume flux, and sediment concentration. The deposition along the jet trajectory is expressed by an ordinary differential equation coupled with the liquid phase equations. Experiments of Lane-Serff and Moran [Sedimentation from Buoyant jets. J Hyd Eng. 2005;131(3):166-174], Cuthbertson and Davies [Deposition from particle-laden, round, turbulent, horizontal, buoyant jets in stationary and coflowing receiving fluids. J Hydr Eng. 2008;134(4):390-402], and Lee [Mixing of horizontal sediment laden jets [dissertation]. Hong Kong: University of Hong Kong; 2010], chosen from bibliography, are used to validate the model. These experiments cover the cases of horizontal and inclined buoyant jets in stationary ambient, horizontal buoyant jets in co-flow current and nonbuoyant horizontal jets in stationary ambient. Good agreement between the experiments and the obtained simulations is revealed. PMID:26732467

  17. MICRO ELECTRICAL DISCHARGE MACHINING DEPOSITION IN AIR

    Institute of Scientific and Technical Information of China (English)

    JIN Baidong; ZHAO Wansheng; WANG Zhenlong; CAO Guohui

    2006-01-01

    A new deposition method is described using micro electrical discharge machining (EDM)to deposit tool electrode material on workpiece in air. The basic principles of micro electrical discharge deposition (EDD) are analyzed and the realized conditions are predicted. With an ordinary EDM shaping machine, brass as the electrode, high-speed steel as the workpiece, a lot of experiments are carried out on micro EDD systematically and thoroughly. The effects of major processing parameters, such as the discharge current, discharge duration, pulse interval and working medium, are obtained. As a result, a micro cylinder with 0.19 mm in diameter and 7.35 mm in height is deposited.By exchanging the polarities of the electrode and workpiece the micro cylinder can be removed selectively. So the reversible machining of deposition and removal is achieved, which breaks through the constraint of traditional EDM. Measurements show that the deposited material is compact and close to workpiece base, whose components depend on the tool electrode material.

  18. Deposition uniformity inspection in IC wafer surface

    Science.gov (United States)

    Li, W. C.; Lin, Y. T.; Jeng, J. J.; Chang, C. L.

    2014-03-01

    This paper focuses on the task of automatic visual inspection of color uniformity on the surface of integrated circuits (IC) wafers arising from the layering process. The oxide thickness uniformity within a given wafer with a desired target thickness is of great importance for modern semiconductor circuits with small oxide thickness. The non-uniform chemical vapor deposition (CVD) on a wafer surface will proceed to fail testing in Wafer Acceptance Test (WAT). Early detection of non-uniform deposition in a wafer surface can reduce material waste and improve production yields. The fastest and most low-priced inspection method is a machine vision-based inspection system. In this paper, the proposed visual inspection system is based on the color representations which were reflected from wafer surface. The regions of non-uniform deposition present different colors from the uniform background in a wafer surface. The proposed inspection technique first learns the color data via color space transformation from uniform deposition of normal wafer surfaces. The individual small region statistical comparison scheme then proceeds to the testing wafers. Experimental results show that the proposed method can effectively detect the non-uniform deposition regions on the wafer surface. The inspection time of the deposited wafers is quite compatible with the atmospheric pressure CVD time.

  19. Atmospheric deposition fluxes to Monetary Bay

    Science.gov (United States)

    Gray, E.; Paytan, A.; Ryan, J.

    2008-12-01

    Atmospheric deposition has been widely recognized as a source of pollutants and nutrients to coastal ecosystems. Specifically, deposition includes nitrogen compounds, sulfur compounds, mercury, pesticides, phosphate, trace metals and other toxic compounds that can travel great distances. Sources of these components include both natural (volcanoes, mineral dust, forest fires) and anthropogenic (fossil fuels, chemical byproducts, incineration of waste) sources, which may contribute to harmful health and environmental impacts such as eutrophication, contaminated fish and harmful algal blooms. This study looks at the flux of aerosol deposition (TSP - total suspended particle load) to Monterey Bay, California. Samples are collected on a cascade impactor aerosol sampler (size fractions PM 2.5 and PM 10) every 48 hours continuously. Preliminary results indicate that the TSP for PM 10 ranged from 0.026 to 0.104 mg m-3 of air and for PM 2.5 from 0.014 to 0.046 mg m-3 of air. Using a deposition velocity of 2 cm s-1 for the large fraction (PM10 - PM 2.5) and a deposition velocity of 0.7 cm s-1 for the fine fraction (PM 2.5) deposition rates are 13 and 86 mg m-2 d-1 respectively.

  20. Stratiform chromite deposit model: Chapter E in Mineral deposit models for resource assessment

    Science.gov (United States)

    Schulte, Ruth F.; Taylor, Ryan D.; Piatak, Nadine M.; Seal, Robert R., II

    2012-01-01

    A new descriptive stratiform chromite deposit model was prepared which will provide a framework for understanding the characteristics of stratiform chromite deposits worldwide. Previous stratiform chromite deposit models developed by the U.S. Geological Survey (USGS) have been referred to as Bushveld chromium, because the Bushveld Complex in South Africa is the only stratified, mafic-ultramafic intrusion presently mined for chromite and is the most intensely researched. As part of the on-going effort by the USGS Mineral Resources Program to update existing deposit models for the upcoming national mineral resource assessment, this revised stratiform chromite deposit model includes new data on the geological, mineralogical, geophysical, and geochemical attributes of stratiform chromite deposits worldwide. This model will be a valuable tool in future chromite resource and environmental assessments and supplement previously published models used for mineral resource evaluation.

  1. Deposition of electrochromic tungsten oxide thin films by plasma-enhanced chemical vapor deposition

    Energy Technology Data Exchange (ETDEWEB)

    Henley, W.B.; Sacks, G.J. [Univ. of South Florida, Tampa, FL (United States). Center of Microelectronics

    1997-03-01

    Use of plasma-enhanced chemical vapor deposition (PECVD) for electrochromic WO{sub 3} film deposition is investigated. Oxygen, hydrogen, and tungsten hexafluoride were used as source gases. Reactant gas flow was investigated to determine the effect on film characteristics. High quality optical films were obtained at deposition rates on the order of 100 {angstrom}/s. Higher deposition rates were attainable but film quality and optical coherence degraded. Atomic emission spectroscopy (AES), was used to provide an in situ assessment of the plasma deposition chemistry. Through AES, it is shown that the hydrogen gas flow is essential to the deposition of the WO{sub 3} film. Oxygen gas flow and tungsten hexafluoride gas flow must be approximately equal for high quality films.

  2. As-grown magnesium diboride superconducting thin films deposited by pulsed laser deposition

    Energy Technology Data Exchange (ETDEWEB)

    Grassano, G.; Ramadan, W.; Ferrando, V.; Bellingeri, E.; Marre, D.; Ferdeghini, C.; Grasso, G.; Putti, M.; Chincarini, A. [INFM, Dipartimento di Fisica, Genoa (Italy); Manfrinetti, P.; Palenzona, A. [INFM, Dipartimento di Chimica e Chimica Industriale, Genoa (Italy)

    2001-09-01

    As-grown superconducting MgB{sub 2} thin films were deposited by pulsed laser deposition on magnesium oxide and sapphire substrates. Starting from a non-stoichiometric, Mg and B mixed-powder target, we were able to grow the superconducting phase during the film deposition, without any further annealing process. So far, samples grown in the temperature range of 400-450 deg. C, and at an argon buffer pressure of the order of 10{sup -2} mbar turned out to be superconducting with an onset temperature of the resistive transition at about 25 K. Even if the deposition process still needs to be fully optimized, we have demonstrated that this method allows us to achieve in situ deposition of as-grown superconducting thin films. This procedure could therefore be promising for the deposition of high-quality epitaxial MgB{sub 2} thin films. (author)

  3. Phanerozoic Rifting Phases And Mineral Deposits

    Science.gov (United States)

    Hassaan, Mahmoud

    2016-04-01

    In North Africa occur Mediterranean and Red Sea metallogenic provinces. In each province distribute 47 iron- manganese- barite and lead-zinc deposits with tectonic-structural control. The author presents in this paper aspects of position of these deposits in the two provinces with Phanerozoic rifting . The Mediterranean Province belongs to two epochs, Hercynian and Alpine. The Hercynian Epoch manganese deposits in only Moroccoa- Algeria belong to Paleozoic tectonic zones and Proterozoic volcanics. The Alpine Epoch iron-manganese deposits are of post-orogenic exhalative-sedimentary origin. Manganese deposits in southern Morocco occur in Kabil-Rief quartz-chalcedony veins controlled by faults in andesitic sheets and in bedded pelitic tuffs, strata-form lenses and ore veins, in Precambrian schist and in Triassic and Cretaceous dolomites. Disseminated manganese with quartz and barite and effusive hydrothermal veins are hosted in Paleocene volcanics. Manganese deposits in Algeria are limited and unrecorded in Tunisia. Strata-form iron deposits in Atlas Heights are widespread in sub-rift zone among Jurassic sediments inter-bedding volcanic rocks. In Algeria, Group Beni-Saf iron deposits are localized along the Mediterranean coast in terrigenous and carbonate rocks of Jurassic, Cretaceous and Eocene age within faults and bedding planes. In Morocco strata-form hydrothermal lead-zinc deposits occur in contact zone of Tertiary andesite inter-bedding Cambrian shale, Lias dolomites and Eocene andesite. In both Algeria and Tunisia metasomatic Pb-Zn veins occur in Campanian - Maastrichtian carbonates, Triassic breccia, Jurassic limestone, Paleocene sandstones and limestone and Neogene conglomerates and sandstones. The Red Sea metallogenic province belongs to the Late Tertiary-Miocene times. In Wadi Araba hydrothermal iron-manganese deposits occur in Cretaceous sediments within 320°and 310 NW faults related to Tertiary basalt. Um-Bogma iron-manganese deposits are closely

  4. [Monitoring nitrogen deposition on temperate grassland in Inner Mongolia].

    Science.gov (United States)

    Zhang, Ju; Kang, Rong-hua; Zhao, Bin; Huang, Yong-mei; Ye, Zhi-xiang; Duan, Lei

    2013-09-01

    Nitrogen deposition on temperate steppe was monitored from November 2011 to October 2012 in Taipusi County, Inner Mongolia. The dry deposition of gaseous nitrogen compounds was calculated based on online-monitored atmospheric concentrations of NH3 and NO2 and dry deposition velocity simulated by CMAQ model. The wet deposition, dry deposition of particle, and throughfall deposition were also estimated by collecting rainfall, dust fall, and throughfall samples and the chemical analysis of NH4+ and NO3-concentrations. Results showed that the total deposition of nitrogen was up to 3.43 g x (m2 x a)(-1), which might be harmful to the ecosystem. The wet deposition accounted for about 44% of the total deposition, while dry deposition of gases and particle accounted for 38% and 18%, respectively. Since the deposition contributed more than wet deposition, a great attention should be paid on dry deposition monitoring. However, the very simple method for total deposition monitoring based on throughfall seemed not suitable for grassland because the monitored throughfall deposition was much lower than the total deposition. In addition, reduced nitrogen (NH4+ and NH3) contributed to 71% of the total deposition, while oxidation nitrogen (NO3- and NO2) was only 29%. Therefore, NH3 emission reduction should be considered as important as nitrogen oxides (NO3x) for controlling nitrogen deposition.

  5. Electrophoretic deposition of titania nanoparticles: Wet density of deposits during EPD

    Indian Academy of Sciences (India)

    Morteza Farrokhi-Rad; Taghi Shahrabi; Shirin Khanmohammadi

    2014-08-01

    Electrophoretic deposition (EPD) of titania nanoparticles was performed at different voltages and times. The wet density of deposits was calculated according to the Archimedes’ principle. The wet density as well as the electric field over the deposits increased with time and attained the plateau at longer times. The velocity at which particles attach to the deposit, strongly influences its wet density at initial times. However, the effect of electro-osmotic flow is dominant at longer times. The coating with higher wet density had the higher corrosion resistance in Ringer’s solution at 37.5 °C due to its closely packed and crack free microstructure.

  6. Novel photochemical vapor deposition reactor for amorphous silicon solar cell deposition

    Science.gov (United States)

    Rocheleau, Richard E.; Hegedus, Steven S.; Buchanan, Wayne A.; Jackson, Scott C.

    1987-07-01

    A novel photochemical vapor deposition (photo-CVD) reactor having a flexible ultraviolet-transparent Teflon curtain and a secondary gas flow to eliminate deposition on the window has been used to deposit amorphous silicon films and p-i-n solar cells. The background levels of atmospheric contaminants (H2O, CO2, N2) depend strongly on the vacuum procedures but not on the presence of a Teflon curtain in the reactor. Intrinsic films with a midgap density of states of 3×1015 eV-1 cm-3 and all-photo-CVD pin solar cells with efficiencies of 8.5% have been deposited.

  7. Uranium deposits in magmatic and metamorphic rocks

    International Nuclear Information System (INIS)

    The association of uranium with certain types of magmatic and metamorphic rocks is well known. They have consequently been explored and studied quite extensively. In recent years interest in them has been eclipsed by the discovery of larger, lower cost deposits in other geological environments. Nonetheless, magmatic and metamorphic rocks continue to be important sources of uranium and large areas of the Earth's crust with such rocks are prospective locations for additional discoveries. As future exploration and development could be more difficult the full importance of individual deposits may not be recognized until after many years of investigation and experience. In addition to being important host rocks, magmatic and metamorphic rocks have been of considerable interest to uranium geologists as they are considered to be important source rocks for uranium and thus can lead to deposits nearby in other environments. Furthermore, these rocks provide important information on the geochemical cycle of uranium in the Earth's crust and mantle. Such information can lead to identification of uranium provinces and districts and to a basic understanding of processes of formation of uranium deposits. The International Atomic Energy Agency convened a Technical Committee Meeting on Uranium Deposits in Magmatic and Metamorphic Rocks. The meeting was held in Salamanca, Spain, from 29 September to 3 October 1986. It was followed by a two day field trip to uranium deposits in the Ciudad Rodrigo and Don Benito areas. The meeting was attended by 48 participants from 22 countries. Two panels were organized for discussion of the following topics: (1) ore deposit genesis and characterization and (2) exploration and resource assessment. The technical papers together with the panel reports form this publication. The scope and variety of the papers included and the panel reports provide a good coverage of current knowledge and thinking on uranium in magmatic and metamorphic rocks

  8. Aerosol Deposition and Solar Panel Performance

    Science.gov (United States)

    Arnott, W. P.; Rollings, A.; Taylor, S. J.; Parks, J.; Barnard, J.; Holmes, H.

    2015-12-01

    Passive and active solar collector farms are often located in relatively dry desert regions where cloudiness impacts are minimized. These farms may be susceptible to reduced performance due to routine or episodic aerosol deposition on collector surfaces. Intense episodes of wind blown dust deposition may negatively impact farm performance, and trigger need to clean collector surfaces. Aerosol deposition rate depends on size, morphology, and local meteorological conditions. We have developed a system for solar panel performance testing under real world conditions. Two identical 0.74 square meter solar panels are deployed, with one kept clean while the other receives various doses of aerosol deposition or other treatments. A variable load is used with automation to record solar panel maximum output power every 10 minutes. A collocated sonic anemometer measures wind at 10 Hz, allowing for both steady and turbulent characterization to establish a link between wind patterns and particle distribution on the cells. Multispectral photoacoustic instruments measure aerosol light scattering and absorption. An MFRSR quantifies incoming solar radiation. Solar panel albedo is measured along with the transmission spectra of particles collected on the panel surface. Key questions are: At what concentration does aerosol deposition become a problem for solar panel performance? What are the meteorological conditions that most strongly favor aerosol deposition, and are these predictable from current models? Is it feasible to use the outflow from an unmanned aerial vehicle hovering over solar panels to adequately clean their surface? Does aerosol deposition from episodes of nearby forest fires impact performance? The outlook of this research is to build a model that describes environmental effects on solar panel performance. Measurements from summer and fall 2015 will be presented along with insights gleaned from them.

  9. Dispersion, deposition and resuspension of atmospheric contaminants

    International Nuclear Information System (INIS)

    The following topics are discussed: dry deposition, oil shale fugitive air emissions, particle resuspension and translocation, theoretical studies and applications, and processing of emissions by clouds and precipitation. The concentration of contaminant species in air is governed by the rate of input from sources, the rate of dilution or dispersion as a result of air turbulence, and the rate of removal to the surface by wet and dry deposition processes. Once on the surface, contaminants also may be resuspended, depending on meteorological and surface conditions. An understanding of these processes is necessary for accurate prediction of exposures of hazardous or harmful contaminants to humans, animals, and crops. In the field, plume dispersion and plume depletion by dry deposition were studied by the use of tracers. Dry deposition was investigated for particles of both respiration and inhalation interest. Complementary dry deposition studies of particles to rock canopies were conducted under controlled conditions in a wind tunnel. Because of increasing concern about hazardous, organic gases in the atmosphere some limited investigations of the dry deposition of nitrobenzene to a lichen mat were conducted in a stirred chamber. Resuspension was also studied using tracers and contaminated surfaces and in the wind tunnel. The objective of the resuspension studies was to develop and verify models for predicting the airborne concentrations of contaminants over areas with surface contamination, develop resuspension rate predictors for downwind transport, and develop predictors for resuspension input to the food chain. These models will be of particular relevance to the evaluation of deposition and resuspension of both radionuclides and chemical contaminants

  10. Information system of mineral deposits in Slovenia

    Science.gov (United States)

    Hribernik, K.; Rokavec, D.; Šinigioj, J.; Šolar, S.

    2010-03-01

    At the Geologic Survey of Slovenia the need for complex overview and control of the deposits of available non-metallic mineral raw materials and of their exploitations became urgent. In the framework of the Geologic Information System we established the Database of non-metallic mineral deposits comprising all important data of deposits and concessionars. Relational database is built with program package MS Access, but in year 2008 we plan to transfer it on SQL server. In the evidence there is 272 deposits and 200 concessionars. The mineral resources information system of Slovenia, which was started back in 2002, consists of two integrated parts, mentioned relational database of mineral deposits, which relates information in tabular way so that rules of relational algebra can be applied, and geographic information system (GIS), which relates spatial information of deposits. . The complex relationships between objects and the concepts of normalized data structures, lead to the practical informative and useful data model, transparent to the user and to better decision-making by allowing future scenarios to be developed and inspected. Computerized storage, and display system is as already said, developed and managed under the support of Geological Survey of Slovenia, which conducts research on the occurrence, quality, quantity, and availability of mineral resources in order to help the Nation make informed decisions using earth-science information. Information about deposit is stored in records in approximately hundred data fields. A numeric record number uniquely identifies each site. The data fields are grouped under principal categories. Each record comprise elementary data of deposit (name, type, location, prospect, rock), administrative data (concessionar, number of decree in official paper, object of decree, number of contract and its duration) and data of mineral resource produced amount and size of exploration area). The data can also be searched, sorted and

  11. Palladium clusters deposited on the heterogeneous substrates

    Science.gov (United States)

    Wang, Kun; Liu, Juanfang; Chen, Qinghua

    2016-07-01

    To improve the performance of the Pd composite membrane prepared by the cold spraying technology, it is extremely essential to give insights into the deposition process of the cluster and the heterogeneous deposition of the big Pd cluster at the different incident velocities on the atomic level. The deposition behavior, morphologies, energetic and interfacial configuration were examined by the molecular dynamic simulation and characterized by the cluster flattening ratio, the substrate maximum local temperature, the atom-embedded layer number and the surface-alloy formation. According to the morphology evolution, three deposition stages and the corresponding structural and energy evolution were clearly identified. The cluster deformation and penetrating depth increased with the enhancement of the incident velocity, but the increase degree also depended on the substrate hardness. The interfacial interaction between the cluster and the substrate can be improved by the higher substrate local temperature. Furthermore, it is found that the surface alloys were formed by exchanging sites between the cluster and substrate atoms, and the cluster atoms rearranged following as the substrate lattice arrangement from bottom to up in the deposition course. The ability and scope of the structural reconstruction are largely determined by both the size and incident energy of the impacted cluster.

  12. Definition and classification of surficial uranium deposits

    International Nuclear Information System (INIS)

    Uraniferous surficial deposits may be broadly defined as uraniferous sediments or soils, usually of Tertiary to Recent age, that have not been subjected to deep burial and may or may not have been cemented to some degree. Evaluation of the available literature shows that confusion has arisen as to the use of the term ''calcrete'' when describing fluviatile sediments that have been calcified to a greater or lesser degree. It is felt that a useful purpose would be served by proposing a classification system which may go some way towards a redefinition of the applicable terminology. Unfortunately the terms ''calcrete'' or ''valley calcrete'' have been used to define Tertiary to Recent sediments ranging from boulder beds to silts which, in some Namibian examples, contain between 5 and 50% CaCO3 and as much as 90% total carbonate in some Australian surficial uranium deposits. It is proposed that the detrital material constituting the sediments be prefixed with the terms calcareous, dolomitic, gypsiferous, halitiferous or ferruginous (e.g. calcareous grit) rather than the terms calcrete, dolocrete, gypcrete, and ferricrete, all of which have genetic connotations. The latter group of terms are preferably used for the pedogenic uranium deposits only. This will have the effect of placing these deposits in categories of their own and not confusing the issue with the overprint of pedogenic calcrete or duricrustal deposits which may or may not be present. This view is not shared by some authorities notably Butt and Carlisle (see this volume). (author)

  13. Deposition of carbonyl sulphide to soils

    Science.gov (United States)

    Kluczewski, S. M.; Brown, K. A.; Bel, J. N. B.

    Carbonyl sulphide (COS) is a trace constituent of the atmosphere and is also the main form in which 35S is released from CO 2-cooled nuclear reactors. Measurements of its deposition velocity ( Vg) are therefore important for validating radiological dose models and for interpreting the role of COS in the global S cycle. The Vg of [ 35S]COS to thin layers of several contrasting soils was measured in a through-flow fumigation system. Deposition velocity was not significantly affected by soil type, although deposition to moist soil was significantly greater ( P dried soils, mean values being 5.71 × 10 -6 ms -1 and 3.06 × 10 -6 ms -1, respectively. The results obtained are about three orders of magnitude smaller than published Vg values for SO 2 to similar soils, which suggests that uptake by soils is not a major sink for atmospheric COS. The results are consistent with the hypothesis that deposition to soil of [ 35S]COS from nuclear reactors is unlikely to contribute significantly to radiation dose from the food chain pathway. The reduction in Vg observed in heat-treated soils indicates a microbial involvement in uptake. However, it seems unlikely that microbial metabolism is the rate-controlling step, since stimulation of the microflora by the addition of nutrients did not increase COS deposition.

  14. Pulsed laser deposition of pepsin thin films

    Energy Technology Data Exchange (ETDEWEB)

    Kecskemeti, G. [Department of Optics and Quantum Electronics, University of Szeged, H-6720 Szeged, Dom ter 9 (Hungary)]. E-mail: kega@physx.u-szeged.hu; Kresz, N. [Department of Optics and Quantum Electronics, University of Szeged, H-6720 Szeged, Dom ter 9 (Hungary); Smausz, T. [Hungarian Academy of Sciences and University of Szeged, Research Group on Laser Physics, H-6720 Szeged, Dom ter 9 (Hungary); Hopp, B. [Hungarian Academy of Sciences and University of Szeged, Research Group on Laser Physics, H-6720 Szeged, Dom ter 9 (Hungary); Nogradi, A. [Department of Ophthalmology, University of Szeged, H-6720, Szeged, Koranyi fasor 10-11 (Hungary)

    2005-07-15

    Pulsed laser deposition (PLD) of organic and biological thin films has been extensively studied due to its importance in medical applications among others. Our investigations and results on PLD of a digestion catalyzing enzyme, pepsin, are presented. Targets pressed from pepsin powder were ablated with pulses of an ArF excimer laser ({lambda} = 193 nm, FWHM = 30 ns), the applied fluence was varied between 0.24 and 5.1 J/cm{sup 2}. The pressure in the PLD chamber was 2.7 x 10{sup -3} Pa. The thin layers were deposited onto glass and KBr substrates. Our IR spectroscopic measurements proved that the chemical composition of deposited thin films is similar to that of the target material deposited at 0.5 and 1.3 J/cm{sup 2}. The protein digesting capacity of the transferred pepsin was tested by adapting a modified 'protein cube' method. Dissolution of the ovalbumin sections proved that the deposited layers consisted of catalytically active pepsin.

  15. Pharmacological approach to evaluate aerosol pulmonary deposition.

    Science.gov (United States)

    Girodet, Pierre-Olivier; Molimard, Mathieu

    2005-01-01

    Drug delivery to the lung in vivo may be assessed using pharmacokinetic or pharmacodynamic techniques. The choice of method depends on drug class specificities. Pharmacokinetic determination of deposition to the lung for drugs without hepatic first-pass effect, such as short acting beta2-agonists, has to be done shortly after inhalation to minimize the effect of gastrointestinal absorption. For medication undergoing important hepatic first-pass metabolisation, such as inhaled corticosteroid, plasma concentration indirectly reflects bronchial deposition. The pharmacodynamic profile should be assessed through clinical effects and adverse events induced by inhaled drugs. Dose ranking of lung deposition for bronchodilators requires patient selection with sufficient bronchial obstruction to maintain room for improvement after the first dose. To assess dose effect relationship between inhaled corticosteroid, the Finney parallel line bioassay is the reference method with a study period of at least 6 weeks. Analysis of side effects with high doses of beta2-agonists or inhaled corticosteroids may also be used to compare lung deposition. Finally, pharmacological evaluation of lung deposition provides complementary information to scintigraphic studies, based on their clinical relevance. PMID:15966772

  16. Model boiler studies on deposition and corrosion

    International Nuclear Information System (INIS)

    Deposit formation was studied in a model boiler, with sea-water injections to simulate the in-leakage which could occur from sea-water cooled condensers. When All Volatile Treatment (AVT) was used for chemistry control the deposits consisted of the sea-water salts and corrosion products. With sodium phosphate added to the boiler water, the deposits also contained the phosphates derived from the sea-water salts. The deposits were formed in layers of differing compositions. There was no significant corrosion of the Fe-Ni-Cr alloy boiler tube under deposits, either on the open area of the tube or in crevices. However, carbon steel that formed a crevice around the tube was corroded severely when the boiler water did not contain phosphate. The observed corrosion of carbon steel was caused by the presence of acidic, highly concentrated chloride solution produced from the sea-water within the crevice. Results of theoretical calculations of the composition of the concentrated solution are presented. (author)

  17. Dry deposition to vegetated surfaces: parametric dependencies

    International Nuclear Information System (INIS)

    The dry deposition velocity of airborne pollutants to vegetated surfaces depends on the physico-chemical form of the pollutant, on meteorological conditions (windspeed, atmospheric stability) and on characteristics of the surface cover. This report examines these dependencies, drawing on experimental data and on information from theoretical analyses. A canopy model is outlined which uses first-order closure of the equations for turbulent transport of momentum (or matter), with losses of momentum (or matter) to individual canopy elements parameterised in terms of the mean windspeed: the model has previously been tested against experimental data on an artificial 'grass' canopy. The model is used to elucidate the features of the dependence of deposition velocity on windspeed and on whether the pollutant is in gaseous or particulate form: in the former case, the dependence on the molecular diffusivity of the gas is shown; in the latter case, dependencies on particle diameter and density are deduced. The predictions are related to available measurements. Additional hypotheses are introduced to treat the influence of atmospheric stability on deposition, and the analysis is used to shed light on the somewhat confusing picture that has emerged from past experimental studies. In considering the dependence of deposition velocity on the structural properties of the vegetation, it is established that more parameters than the single one conventionally used -aerodynamic roughness length - are needed to characterise the surface cover. Some indications of the extent of variation in deposition velocity from one type of vegetation to another are elicited from the model. (author)

  18. THE WATERSHED DEPOSITION TOOL: A MEANS TO LINK ATMOSPHERIC DEPOSITION TO WATERSHEDS

    Science.gov (United States)

    The potential for atmospheric deposition reductions to contribute to water quality management is not being included in many planning exercises. This is because often the water quality scientists do not know where to get and how to use projections of atmospheric deposition reducti...

  19. Alternate slicing and deposition strategies for fused deposition modelling of light curved parts

    Directory of Open Access Journals (Sweden)

    B. Huang

    2012-12-01

    Full Text Available Fused deposition modeling (FDM, as one of the additive manufacturing (AM techniques, has been widely used in the manufacturing industry from the 1990s. It is relatively cheaper than other AM methods and there are other advantages such as being able to process a variety of other polymers. Currently, FDM is more likely to be suitable for direct production of the terminal-use parts, in some cases challenging traditional process such as injection molding. Research evidences indicate that change of road and layer structure would have significant influence on the meso-structure and thus impact the mechanical properties of the resulting polymer parts. Adaptive flat layer deposition and curved layer deposition have been introduced to improve the mechanical properties of terminal-use product. It is necessary that an appropriate deposition scheme is essential to ensure the best interroad and inter-layer connectivity. Uninterrupted connections are likely to result in a continuous network of polymer chains, as in the case of the conventional processes. The current research proposes conventional flat layer deposition, adaptive flat layer deposition and curved layer deposition for FDM. In particular for curved parts, curved layer deposition in expected to ensure fiber continuity and better meso-structure. Mathematical models are developed for curved slicing, practically implemented to print physical parts and test results suggest marked improvement in the mechanical characteristics of curved parts.

  20. Interplay between the deposition mode and microstructure in electrochemically deposited Cu thin films

    Energy Technology Data Exchange (ETDEWEB)

    Kremmer, K. [Institute of Materials Science, TU Bergakademie Freiberg, Gustav-Zeuner-Str. 5, D-09599 Freiberg (Germany); Yezerska, O. [Fraunhofer Institute for Manufacturing Technology and Applied Materials Research, Wiener Str. 12, D-28359 Bremen (Germany); Schreiber, G. [Institute of Materials Science, TU Bergakademie Freiberg, Gustav-Zeuner-Str. 5, D-09599 Freiberg (Germany); Masimov, M. [Institute of Materials Science, TU Bergakademie Freiberg, Gustav-Zeuner-Str. 5, D-09599 Freiberg (Germany); Klemm, V. [Institute of Materials Science, TU Bergakademie Freiberg, Gustav-Zeuner-Str. 5, D-09599 Freiberg (Germany); Schneider, M. [Fraunhofer Institute for Manufacturing Technology and Applied Materials Research, Wiener Str. 12, D-28359 Bremen (Germany); Rafaja, D. [Institute of Materials Science, TU Bergakademie Freiberg, Gustav-Zeuner-Str. 5, D-09599 Freiberg (Germany)]. E-mail: rafaja@ww.tu-freiberg.de

    2007-06-13

    The influence of the electrochemical potential and the deposition mode on the preferred orientation and morphology of crystallites and on the microstrain in electrochemically deposited copper thin films was investigated using a combination of cyclic voltammetry, chronoamperometry, X-ray diffraction, SEM and the diffraction of backscattered electrons. With increasing negative electrochemical potential, the deposition mode changed from the charge transfer controlled one to the diffusion controlled one. At the highest electrochemical potentials, copper deposition was accompanied by hydrogen reduction. In potentiostatically deposited thin films, the preferred orientation of crystallites changed from {l_brace}111{r_brace} in the charge transfer controlled deposition mode to {l_brace}110{r_brace} in the diffusion controlled one. The increase of the electrochemical potential in the charge transport controlled deposition mode caused an increase of the dislocation density. The increasing electrochemical potential in the diffusion controlled mode led to a decrease of the dislocation density. The copper deposition, which was accompanied by the hydrogen reduction, produced needle-like crystallites with the {l_brace}100{r_brace} texture and with the lowest dislocation density.

  1. The uranium ore deposits in Ciudad Rodrigo Phyllites. about the possibility of new deposits

    International Nuclear Information System (INIS)

    The main features of the genesis of uranium deposits of the Fe mine type, are discussed in this paper. Pitchblende ore is related with phyllites bearing organic material and with geomorphological level, fossilized by eocene sediments. As a result, new uranium ore deposits are possible under Ciudad Rodrigo tertiary basin, tertiary cover depth being little more than three hundred feet. (Author)

  2. Deposition of Thin Film Electrolyte by Pulsed Laser Deposition (PLD) for micro-SOFC Development

    OpenAIRE

    Krogstad, Hedda Nordby

    2012-01-01

    Optimalization of PLD deposition of YSZ for micr-SOFC electrolyte applications by varying deposition pressure and target-substrate distance.Substrate used was Si-based chips and wafers (large area PLD), and the substrate temperature was held at 600. Dense films were obtained at 20 mTorr.

  3. 76 FR 7740 - Amendments to Deposit Insurance Regulations: Deposit Insurance Coverage Training; SMDIA Notification

    Science.gov (United States)

    2011-02-11

    .... Becker, Senior Consumer Affairs Specialist, Deposit Insurance Section, Division of Supervision and Consumer Protection, (202) 898-6644, mbecker@fdic.gov ; or Catherine A. ] Ribnick, Counsel, Legal Division... insurance training requirement on third parties (e.g., deposit brokers or affinity groups) that directly...

  4. Spatial atomic layer deposition: a route towards further industrialization of atomic layer deposition

    NARCIS (Netherlands)

    Poodt, P.W.G.; Cameron, D.C.; Dickey, E.; George, S.M.; Kuznetsov, V.; Parsons, G.N.; Roozeboom, F.; Sundaram, G.; Vermeer, A.

    2012-01-01

    Atomic layer deposition (ALD) is a technique capable of producing ultrathin conformal films with atomic level control over thickness. A major drawback of ALD is its low deposition rate, making ALD less attractive for applications that require high throughput processing. An approach to overcome this

  5. The Effect of Deposition Time on Textured Magnesium Diboride Thick Films Fabricated by Electrophoretic Deposition

    Directory of Open Access Journals (Sweden)

    W. G. Mutia

    2004-12-01

    Full Text Available MgB2 powders suspended in ethanol were electrophoretically deposited on high-purity molybdenum substrates having dimensions of 1 x 0.3 x 0.01 cm. The said substrate was set as the cathode and was placed 0.5 cm away from a graphite rod anode. A current density of ~0.02 mA/cm2 and a voltage of 600 V were applied. The effect of deposition time was studied by varying it as follows: 15 s, 30 s, 1 min, and 2 min. Heat treatment at 950 oC for 3 h was done after deposition. MgB2 thick films were successfully fabricated for the deposition carried out for 2 min. Deposition times less than 2 min resulted in insufficient deposited powder; hence formation of MgB2 was not facilitated. Films deposited at 15 and 30 s have good surface characteristics, wherein no microcracks were present. X-ray diffraction and surface image analysis reveal that the deposited films have a preferred orientation along the (10l direction.

  6. Factors influencing chloride deposition in a coastal hilly area and application to chloride deposition mapping

    Directory of Open Access Journals (Sweden)

    H. Guan

    2010-05-01

    Full Text Available Chloride is commonly used as an environmental tracer for studying water flow and solute transport in the environment. It is especially useful for estimating groundwater recharge based on the commonly used chloride mass balance (CMB method. Strong spatial variability in chloride deposition in coastal areas is one difficulty encountered in appropriately applying the method. A high-resolution bulk chloride deposition map in the coastal region is thus needed. The aim of this study is to construct a chloride deposition map in the Mount Lofty Ranges (MLR, a coastal hilly area of approximately 9000 km2 spatial extent in South Australia. We examined geographic (related to coastal distance, orographic, and atmospheric factors that may influence chloride deposition, using partial correlation and regression analyses. The results indicate that coastal distance, elevation, as well as terrain aspect and slope, appear to be significant factors controlling chloride deposition in the study area. Coastal distance accounts for 70% of spatial variability in bulk chloride deposition, with elevation, terrain aspect and slope an additional 15%. The results are incorporated into a de-trended residual kriging model (ASOADeK to produce a 1 km×1 km resolution bulk chloride deposition and concentration maps. The average uncertainty of the deposition map is about 20–30% in the western MLR, and 40–50% in the eastern MLR. The maps will form a useful basis for examining catchment chloride balance for the CMB application in the study area.

  7. 24 CFR 882.414 - Security and utility deposits.

    Science.gov (United States)

    2010-04-01

    ... 24 Housing and Urban Development 4 2010-04-01 2010-04-01 false Security and utility deposits. 882... Moderate Rehabilitation-Basic Policies § 882.414 Security and utility deposits. (a) If at the time of the... security deposits and utility deposits from its resources and/or other public or private sources. (b) If...

  8. 24 CFR 884.115 - Security and utility deposits.

    Science.gov (United States)

    2010-04-01

    ... 24 Housing and Urban Development 4 2010-04-01 2010-04-01 false Security and utility deposits. 884... Security and utility deposits. (a) An Owner may require Families to pay a security deposit in an amount... security and utility deposits, if required, from their own resources and/or other private or public sources....

  9. 24 CFR 886.116 - Security and utility deposits.

    Science.gov (United States)

    2010-04-01

    ... 24 Housing and Urban Development 4 2010-04-01 2010-04-01 false Security and utility deposits. 886... utility deposits. (a) An Owner may require Families to pay a security deposit in an amount up to, but not... utility deposits, if required, from their own resources and/or other private or public sources....

  10. Electroless Deposition of Fe-Mo-W-B Amorphous Alloys

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The preparation, formation mechanism, surface appearance and structure of electroless plating Fe-Mo-W-B amorphous alloys were systematically studied. The deposition rates of the deposits in different bath composition as plated were measured. The formation mechanism of the deposits was discussed. The parameter for amorphous structures formation was suggested for the deposits.

  11. 37 CFR 1.807 - Viability of deposit.

    Science.gov (United States)

    2010-07-01

    ... 37 Patents, Trademarks, and Copyrights 1 2010-07-01 2010-07-01 false Viability of deposit. 1.807... Biological Material § 1.807 Viability of deposit. (a) A deposit of biological material that is capable of... term of deposit. Viability may be tested by the depository. The test must conclude only that...

  12. 7 CFR 27.92 - Method of payment; advance deposit.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Method of payment; advance deposit. 27.92 Section 27... Micronaire § 27.92 Method of payment; advance deposit. Any payment or advance deposit under this subpart...,” and may not be made in cash except in cases where the total payment or deposit does not exceed...

  13. Influence of deposition time on the properties of chemical bath deposited manganese sulfide thin films

    Directory of Open Access Journals (Sweden)

    Anuar Kassim

    2010-12-01

    Full Text Available Manganese sulfide thin films were chemically deposited from an aqueous solution containing manganese sulfate, sodium thiosulfate and sodium tartrate. The influence of deposition time (2, 3, 6 and 8 days on the properties of thin films was investigated. The structure and surface morphology of the thin films were studied by X-ray diffraction and atomic force microscopy, respectively. In addition, in order to investigate the optical properties of the thin films, the UV-visible spectrophotometry was used. The XRD results indicated that the deposited MnS2 thin films exhibited a polycrystalline cubic structure. The number of MnS2 peaks on the XRD patterns initially increased from three to six peaks and then decreased to five peaks, as the deposition time was increased from 2 to 8 days. From the AFM measurements, the film thickness and surface roughness were found to be dependent on the deposition time.

  14. Structural and Optical Properties of Chemical Bath Deposited Silver Oxide Thin Films: Role of Deposition Time

    Directory of Open Access Journals (Sweden)

    A. C. Nwanya

    2013-01-01

    Full Text Available Silver oxide thin films were deposited on glass substrates at a temperature of 50°C by chemical bath deposition technique under different deposition times using pure AgNO3 precursor and triethanolamine as the complexing agent. The chemical analysis based on EDX technique shows the presence of Ag and O at the appropriate energy levels. The morphological features obtained from SEM showed that the AgxO structures varied as the deposition time changes. The X-ray diffraction showed the peaks of Ag2O and AgO in the structure. The direct band gap and the refractive index increased as the deposition time increased and was in the range of 1.64–1.95 eV and 1.02–2.07, respectively. The values of the band gap and refractive index obtained indicate possible applications in photovoltaic and photothermal systems.

  15. Effect of deposition pressure and post deposition annealing on SmCo thin film properties

    International Nuclear Information System (INIS)

    In this article we report on the effect of the deposition pressure and the post deposition annealing conditions on the structural and magnetic properties of SmCo thin films deposited on Si(100) wafers employing Ta buffer and capping layers. The films were deposited by DC magnetron sputtering and annealed in vacuum at various temperatures. The films under investigation were isotropic with high remanence magnetization, maximum coercive field of 8 kOe and a squareness ratio of coercivity higher than 0.9. It was found that the Ar pressure during the deposition is a key factor in controlling the stoichiometry and the structural and magnetic properties of the SmCo films, while the effect of the annealing temperature is crucial in optimizing the magnetic properties of the films. (copyright 2008 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  16. Atomic-layer deposition of silicon nitride

    CERN Document Server

    Yokoyama, S; Ooba, K

    1999-01-01

    Atomic-layer deposition (ALD) of silicon nitride has been investigated by means of plasma ALD in which a NH sub 3 plasma is used, catalytic ALD in which NH sub 3 is dissociated by thermal catalytic reaction on a W filament, and temperature-controlled ALD in which only a thermal reaction on the substrate is employed. The NH sub 3 and the silicon source gases (SiH sub 2 Cl sub 2 or SiCl sub 4) were alternately supplied. For all these methods, the film thickness per cycle was saturated at a certain value for a wide range of deposition conditions. In the catalytic ALD, the selective deposition of silicon nitride on hydrogen-terminated Si was achieved, but, it was limited to only a thin (2SiO (evaporative).

  17. Uranium and thorium deposits of Northern Ontario

    International Nuclear Information System (INIS)

    This, the second edition of the uranium-thorium deposit inventory, describes briefly the deposits of uranium and/or thorium in northern Ontario, which for the purposes of this circular is defined as that part of Ontario lying north and west of the Grenville Front. The most significant of the deposits described are fossil placers lying at or near the base of the Middle Precambrian Huronian Supergroup. These include the producing and past-producing mines of the Elliot Lake - Agnew Lake area. Also included are the pitchblende veins spatially associated with Late Precambrian (Keweenawan) diabase dikes of the Theano Point - Montreal River area. Miscellaneous Early Precambrian pegmatite, pitchblende-coffinite-sulphide occurrences near the Middle-Early Precambrian unconformity fringing the Lake Superior basin, and disseminations in diabase, granitic rocks, alkalic complexes and breccias scattered throughout northern Ontario make up the rest of the occurrences

  18. Worldwide deposition of strontium-90 through 1990

    International Nuclear Information System (INIS)

    Strontium-90 results from the Environmental Measurements Laboratory's (EML) Global Fallout Program (GFP) are presented for the years 1987 through 1990. Quarterly 90Sr deposition results for the 66 sampling locations of EML's GFP were generally low, indicating that there was no significant release of fission products into the atmosphere during this period. The global 90Sr deposition during these 4 years was lower than it has been for any similar period since this program began in 1958. Since there was no major atmospheric source of 90Sr during this period, the global cumulative deposit of 90Sr continued to decrease by radioactive decay to a 27 year low of 311.4 Pbq

  19. Model calculations to formation of salt deposits

    International Nuclear Information System (INIS)

    The present work is a contribution from the geophysical side and its target is to explain the formation of long stretched salt deposits - salt walls - in a better manner than has been done sofar using model calculations. A few works have already been dedicated to this subject (they are treated in chapter 5). They all have the disadvantage however in not being able to represent the time sequence of the salt deposit generations. Precisely the latter is achieved in this work by including assumed initial interference. The values for the salt wall distance and its growth rate are improved upon. The Schleswig-Holstein salt deposit is taken as example. The model calculations are supported by model experiments. (orig.)

  20. Washout and dry deposition of atmospheric aerosols

    International Nuclear Information System (INIS)

    The deposition velocities onto different rough surfaces and the washout coefficients of simulated rain droplets for submicron aerosols were studied in a wind channel. The influence of particle size and electric charge upon the collection efficiencies of simulated rain droplets was measured. The deposition velocity of the particles was determined as a function of aerosol size, wind velocity and roughness of the surface. The experiments were carried out with monodisperse, radioactive particles with sizes which were varied from 0.03 and 5 μm. Using the measured values, the activity flux of the long lived radon decay product (RaD), the mass flux of the atmospheric aerosol and the activity flux near a stack of a nuclear power plant onto the ground surface were calculated considering washout, rainout and dry deposition in the atmosphere. (author)

  1. Crud deposition modeling on BWR fuel rods

    International Nuclear Information System (INIS)

    Deposition of boiling water reactor (BWR) system corrosion products (crud) on operating fuel rods has resulted in performance-limiting conditions in a number of plants. The operational impact of performance-limiting conditions involving crud deposition can be detrimental to a BWR operator, resulting in unplanned or increased frequency of fuel inspections, fuel failure and associated radiological consequences, operational restrictions including core power derate and/or forced shutdowns to remove failed fuel, premature discharge of individual bundles or entire reloads, and/or undesirable core design restrictions. To facilitate improved management of crud-related fuel performance risks, EPRI has developed the CORAL (Crud DepOsition Risk Assessment ModeL) tool. This paper presents a summary of the CORAL elements and benchmarking results. Applications of CORAL as a tool for fuel performance risk assessment are also discussed. (author)

  2. Deposit control in process cooling water systems

    International Nuclear Information System (INIS)

    In order to achieve efficient heat transfer in cooling water systems, it is essential to control the fouling of heat exchanger surfaces. Solubilities of scale forming salts, their growth into crystals, and the nature of the surfaces play important roles in the deposition phenomenon. Condensed phosphates, organic polymers and compounds like phosphates are effective in controlling deposition of scale forming salts. The surface active agents inhibit crystal growth and modify the crystals of the scale forming salts, and thus prevent deposition of dense, uniformly structured crystalline mass on the heat transfer surface. Understanding the mechanism of biofouling is essential to control it by surface active agents. Certain measures taken in the plant, such as back flushing, to control scaling, sometimes may not be effective and can be detrimental to the system itself. (author)

  3. Deposition of nitrogen into the North Sea

    DEFF Research Database (Denmark)

    Leeuw, G. de; Skjøth, C.A.; Hertel, O.;

    2003-01-01

    , NO3-, NH3 and NH4+) into the North Sea and the processes governing this deposition. The Southern North Sea was studied as a prototype. Because the physical and chemical processes are described, as opposed to empirical relations, the results can potentially be transferred to other regional seas like...... and Harwich/Newcastle. These measurements provided data for sensitivity studies of a variety of problems associated with the coastal region that are not easily evaluated with larger scale models, to constrain models and to test model results. Concentrations of nitrogen compounds over the North Sea...... and the resulting deposition presented in this paper were obtained with the Lagrangian transport-chemistry model ACDEP. The average annual deposition in 1999 was 906 kg N km(-2). The results are compared with experimental data from the ferry. Effects of temporal and spatial variations are evaluated based...

  4. Sputtering. [as deposition technique in mechanical engineering

    Science.gov (United States)

    Spalvins, T.

    1976-01-01

    This paper primarily reviews the potential of using the sputtering process as a deposition technique; however, the manufacturing and sputter etching aspects are also discussed. Since sputtering is not regulated by classical thermodynamics, new multicomponent materials can be developed in any possible chemical composition. The basic mechanism for dc and rf sputtering is described. Sputter-deposition is described in terms of the unique advantageous features it offers such as versatility, momentum transfer, stoichiometry, sputter-etching, target geometry (coating complex surfaces), precise controls, flexibility, ecology, and sputtering rates. Sputtered film characteristics, such as strong adherence and coherence and film morphology, are briefly evaluated in terms of varying the sputtering parameters. Also described are some of the specific industrial areas which are turning to sputter-deposition techniques.

  5. Patterned deposition at moving contact lines

    CERN Document Server

    Thiele, Uwe

    2013-01-01

    When a simple or complex liquid recedes from a smooth solid substrate it often leaves a homogeneous or structured deposit behind. In the case of a receding non-volatile pure liquid the deposit might be a liquid film or an arrangement of droplets depending on the receding speed of the meniscus and the wetting properties of the system. For complex liquids with volatile components as, e.g., polymer solutions and particle or surfactant suspensions, the deposit might be a homogeneous or structured layer of solute - with structures ranging from line patterns that can be orthogonal or parallel to the receding contact line via hexagonal or square arrangements of drops to complicated hierarchical structures. We review a number of recent experiments and modelling approaches with a particular focus on mesoscopic hydrodynamic long-wave models. The conclusion highlights open question and speculates about future developments.

  6. Multi-Constituent Simulation of Thrombus Deposition

    CERN Document Server

    Wu, Wei-Tao; Massoudi, Mehrdad; Wagner, William R; Antaki, James F

    2016-01-01

    Based on the transport model of Sorensen et al. (1999), an improved mathematical model describing the process of thrombus deposition and growth was developed. Blood is treated as a multi-constituent mixture comprised of a linear fluid phase and a thrombus phase. The transport and reactions of 10 chemical and biological species are modeled using a system of coupled convection-reaction-diffusion (CRD) equations. These represent three main processes: initiation, propagation and stabilization. Computational fluid dynamic (CFD) simulations using the libraries of OpenFOAM were performed for two illustrative benchmark problems: mural thrombus growth in an injured blood vessel and thrombus deposition in a small (125 x 95 micros) crevice observed in vitro. For both problems, the simulated thrombus deposition agreed very well with experimental observations, both spatially and temporally. These promising results encourage further simulations to investigate clinical conditions and design factors that affect the risk of t...

  7. MOCVD deposition of YSZ on stainless steels

    Science.gov (United States)

    Chevalier, S.; Kilo, M.; Borchardt, G.; Larpin, J. P.

    2003-01-01

    Yttria stabilized zirconia was deposited on stainless steel using the metal-organic chemical vapor deposition (MOCVD) technique, from β-diketonate precursors. The variation of the evaporation temperatures of yttrium and zirconium precursor allowed to control the level of Y within the film. Over the temperature range 125-150 °C, the Y content increased from 2.5 to 17.6 at.%. X-ray diffraction (XRD) analyses evidenced tetragonal phase of zirconia when the Y content was below 8 at.%, and cubic phase for higher concentration. Sputtered neutral mass spectrometry (SNMS) profiles confirmed that the control and stability of Y precursor temperature were of major importance to guarantee the homogeneity of the deposited films.

  8. Simulation of Indoor Fine Suspension Particle Deposition

    Science.gov (United States)

    Li, K. Q.; Gong, G. C.; Zou, S. H.

    In this paper, the migration and deposition of particles are simulated using the Moment Dynamic Equation (MDE). Indoor fine suspension particle depositions and particle distribution function are obtained. Gas phase flow is simulated by v 2 - f model. The simulated results of particle concentration profiles show that a uniform concentration exists in the middle region of the room with a low supplying speed. At the same time, the total number of partciels deposited is also obtained using Gradient diffusion model. Through the comparison of velocity predictions among several CFD k-ɛ models and v 2 -f model and experimental data, it is concluded that the results obtained by v 2 -f model more accurately approximate the experimental data. So that the MDE combined v 2 -f model will gain in popularity amongst building engineers and it will gradually be adopted as an attractive alternative tool to predict contaminant particle dispersion and distribution.

  9. Texture of atomic layer deposited ruthenium

    OpenAIRE

    Musschoot, J.; Xie, Q; Deduytsche, D.; De Keyser, K; Longrie, D.; Haemers, J.; Van den Berghe, S.; Van Meirhaeghe, R. L.; D'Haen, Jan; Detavernier, C

    2010-01-01

    Ruthenium films were grown by plasma enhanced atomic layer deposition (ALD) on Si(1 0 0) and ALD TiN. X-ray diffraction (XRD) showed that the as-deposited films on Si(1 0 0) were polycrystalline, on TiN they were (0 0 2) oriented. After annealing at 800 degrees C for 60 s, all Ru films were strongly (0 0 2) textured and very smooth. Electron backscatter diffraction (EBSD) and transmission electron microscopy (TEM) demonstrated that the lateral grain size of the annealed films was several 100 ...

  10. Tax evasion and Swiss bank deposits

    DEFF Research Database (Denmark)

    Johannesen, Niels

    2014-01-01

    Bank deposits in offshore financial centers may be used to evade taxes on interest income. A recent EU reform limits the scope for this type of tax evasion by introducing a withholding tax on interest income earned by EU households in Switzerland and several other offshore centers. This paper...... quarters immediately before and after the tax was introduced. We also present evidence suggesting that the drop in Swiss bank deposits was driven by behavioral responses aiming to escape the tax - such as the transfer of funds to bank accounts in other offshore centers and the transfer of formal ownership...... of Swiss bank accounts to offshore holding companies - rather than repatriation of funds...

  11. Treating paraffin deposits in producing oil wells

    Energy Technology Data Exchange (ETDEWEB)

    Noll, L.

    1992-01-01

    Paraffin deposition has been a problem for operators in many areas since the beginning of petroleum production from wells. An extensive literature search on paraffin problems and methods of control has been carried out, and contact was made with companies which provide chemicals to aid in the treatment of paraffin problems. A discussion of the nature of paraffins and the mechanisms of this deposition is presented. The methods of prevention and treatment of paraffin problems are summarized. Suggested procedures for handling paraffin problems are provided. Suggestions for areas of further research testing are given.

  12. Shanxi Finding Another Large Bauxite Deposit

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    <正>According to Department of Resources of Shanxi,a new breakthrough has been made on the prospecting in the province.The preliminary result shows that another large bauxite mine has been found in Shiqie River in Baode County with a deposit height of 0.81- 8.01m and an estimate reserve of 140 million tons.Meanwhile 3 large-and 3 medium-size bauxite deposits have also been found in the northwest part of Shanxi including Hejiaqianhe of Xin County with an estimate reserve of 37.1 million tons and Beiguli of Jiaokou County.

  13. Bioactive surfaces with atomic layer deposition

    OpenAIRE

    Kvalvik, Julie Nitsche

    2015-01-01

    The overall goal of this work has been to make bioactive surfaces with atomic layer deposition (ALD). To do this, a new ALD system with titanium tetraisopropoxide (TTIP) and lysine as precursors was developed with emphasis on studying the effects of pulsing times and deposition temperatures. TTIP was chosen as titanium is regarded to be biocompatible and lysine was chosen as poly-L-lysine is a part of the extra-cellular matrix (ECM) and hence affects cell adhesion. The effect of a water pulse...

  14. Risk Adjusted Deposit Insurance for Japanese Banks

    OpenAIRE

    Ryuzo Sato; Rama V. Ramachandran; Bohyong Kang

    1990-01-01

    The purpose of this paper is to evaluate the Japanese deposit insurance scheme by contrasting the flat insurance rate with a market-determined risk-adjusted rate. The model used to calculate the risk-adjusted rate is that of Ronn and Verrna (1986) . It utilizes the notion of Merton(1977) that the deposit insurance can be based on a one-to-one relation between it and the put option; this permits the application of Black and Scholes(1973) model for the calculation of the insurance rate. The ris...

  15. Polymer-assisted deposition of films

    Science.gov (United States)

    McCleskey,Thomas M.; Burrell,Anthony K.; Jia,Quanxi; Lin,Yuan

    2012-02-28

    A polymer assisted deposition process for deposition of metal nitride films and the like is presented. The process includes solutions of one or more metal precursor and soluble polymers having binding properties for the one or more metal precursor. After a coating operation, the resultant coating is heated at high temperatures under a suitable atmosphere to yield metal nitride films and the like. Such films can be conformal on a variety of substrates including non-planar substrates. In some instances, the films can be epitaxial in structure and can be of optical quality. The process can be organic solvent-free.

  16. XRF analysis of depth profiled thin depositions

    International Nuclear Information System (INIS)

    The main information about atmospheric and water pollutants is obtained from analysis of thin depositions on filters. Due its high sensitivity for a large number of elements, the XRF analysis based on X-ray tube as source of excitation, is a very advantageous method to measure samples of this kind. However, due to very large absorption photon cross sections in this energy range, the deposition profile can play an important role in analysis. Neglecting it might lead in some cases to wrong results. Assuming a normalized exponentially decaying profile as a realistic approximation of the deposition profile of a given element as ρ(x) = mkme-kmx/(1- e-kmD), where ρ(x) is element density at depth x, m - its surface density, km - deposition parameter and D - sample thickness, the yield, Y(km), of a characteristic X-line measured on a side of the sample is given as a function of Φ(E) - incident X-ray flux at energy E, σf(E) - photoelectric absorption cross section of the element, χ(E) - total X-ray absorption coefficient in sample considering both incidence and emergence path. Measuring the sample on the opposite side, the yield will be Y(-km), while from the ratio Y(-km)/Y(km) can be determined numerically. Since y(km) = Y(km)/m is independent of m, the deposition superficial mass is calculated using a thick standard as m = Y(s)S(x)/y(km)S(s), where S(x) (S(s)) is the X-line intensity measured in sample (standard) and theoretical yield in standard Y(s) is calculated using the formulas of Shiraiwa and Fujino. A computer code based on this formalism was written. Many samples of wet soil and aerosols deposition on filters, previously measured by other methods, were used to check the correctness of the present analysis procedure and a very good agreement is found between our results and the measurements taken as reference. A table is given with the results of the IAEA soil standard SOIL-7, deposited wet on a thin filter and measured after drying. The soil deposition was 3

  17. Skin deposits in hereditary cystatin C amyloidosis

    DEFF Research Database (Denmark)

    Benedikz, Eirikur; Blöndal, H; Gudmundsson, G

    1990-01-01

    Clinically normal skin from 47 individuals aged 9-70 years was investigated. Cystatin C amyloid deposits were found in various locations of the skin by light and/or electron microscopy, in all 12 patients with a clinical history of hereditary cystatin C amyloidosis (HCCA). Six asymptomatic...... individuals, who had the Alu 1 restriction fragment length polymorphism (RFLP) marker reported to cosegregate with the disease, also had cystatin C amyloid deposits in the skin. Three asymptomatic individuals (age 17-46) belonging to the HCCA families were without amyloid in the skin but had Alu 1 RFLP marker...

  18. Diamond deposition on siliconized stainless steel

    International Nuclear Information System (INIS)

    Silicon diffusion layers in AISI 304 and AISI 316 type stainless steels were investigated as an alternative to surface barrier coatings for diamond film growth. Uniform 2 μm thick silicon rich interlayers were obtained by coating the surface of the steels with silicon and performing diffusion treatments at 800 deg. C. Adherent diamond films with low sp2 carbon content were deposited on the diffused silicon layers by a modified hot filament assisted chemical vapor deposition (HFCVD) method. Characterization of as-siliconized layers and diamond coatings was performed by energy dispersive X-ray analysis, scanning electron microscopy, X-ray diffraction and Raman spectroscopy.

  19. Electrochemical Deposition Of Thiolate Monolayers On Metals

    Science.gov (United States)

    Porter, Marc D.; Weissharr, Duane E.

    1995-01-01

    Electrochemical method devised for coating metal (usually, gold) surfaces with adherent thiolate monolayers. Affords greater control over location and amount of material deposited and makes it easier to control chemical composition of deposits. One important potential use for this method lies in fabrication of chemically selective thin-film resonators for microwave oscillators used to detect pollutants: monolayer formulated to bind selectively pollutant chemical species of interest, causing increase in mass of monolayer and corresponding decrease in frequency of resonance. Another important potential use lies in selective chemical derivatization for purposes of improving adhesion, lubrication, protection against corrosion, electrocatalysis, and electroanalysis.

  20. Atomic Layer Deposition from Dissolved Precursors.

    Science.gov (United States)

    Wu, Yanlin; Döhler, Dirk; Barr, Maïssa; Oks, Elina; Wolf, Marc; Santinacci, Lionel; Bachmann, Julien

    2015-10-14

    We establish a novel thin film deposition technique by transferring the principles of atomic layer deposition (ALD) known with gaseous precursors toward precursors dissolved in a liquid. An established ALD reaction behaves similarly when performed from solutions. "Solution ALD" (sALD) can coat deep pores in a conformal manner. sALD offers novel opportunities by overcoming the need for volatile and thermally robust precursors. We establish a MgO sALD procedure based on the hydrolysis of a Grignard reagent.

  1. Distribution And Mineralogy Of The Clay Deposits In Saudi Arabia

    OpenAIRE

    Al Mohandis, Ahmed A. [احمد عبد القادر المهندس

    1993-01-01

    The main goal of this paper is to characterize the mineral clay deposits in Saudi Arabia; especially their mineral composition, deposit size, geological setting and possible uses. Different published reports and papers on clay deposits of Saudi Arabia have been reviewed. Three major clay deposits have been studied by XRD, DTA and chemical analyses. Saudi clay deposits consist generally of kaolinite as a major mineral, and small amounts other clay minerals, such as montmorillonite and illite. ...

  2. Dual ion beam assisted deposition of biaxially textured template layers

    Energy Technology Data Exchange (ETDEWEB)

    Groves, James R.; Arendt, Paul N.; Hammond, Robert H.

    2005-05-31

    The present invention is directed towards a process and apparatus for epitaxial deposition of a material, e.g., a layer of MgO, onto a substrate such as a flexible metal substrate, using dual ion beams for the ion beam assisted deposition whereby thick layers can be deposited without degradation of the desired properties by the material. The ability to deposit thicker layers without loss of properties provides a significantly broader deposition window for the process.

  3. 12 CFR 347.203 - Deposit insurance required for all branches of foreign banks engaged in domestic retail deposit...

    Science.gov (United States)

    2010-01-01

    ... foreign banks engaged in domestic retail deposit activity in the same State. 347.203 Section 347.203 Banks... engaged in domestic retail deposit activity in the same State. The FDIC will not insure deposits in any... foreign bank in the same state that engages in domestic retail deposit activity will be an insured branch....

  4. A literature review on wet deposition

    International Nuclear Information System (INIS)

    The literature on wet deposition or precipitation scavenging have been reviewed with special reference to predicting the radiological consequences of accidental contamination. The work was part of the EEC Radiation Protection Programme and done under a subcontract with Association Euratom-C.E.A. No. SC-014-BIAF-423-DK(SD). (author)

  5. 78 FR 13212 - Investment and Deposit Activities

    Science.gov (United States)

    2013-02-27

    ... valuable portfolio management tool when there are inflationary risks in the economy. \\4\\ 77 FR 59144 (Sept... ADMINISTRATION 12 CFR Part 703 RIN 3133-AE06 Investment and Deposit Activities AGENCY: National Credit Union Administration (NCUA). ACTION: Final rule. SUMMARY: The NCUA Board (Board) is amending its investment...

  6. Deposition of biopolymer films on micromechanical sensors

    DEFF Research Database (Denmark)

    Keller, Stephan Sylvest; Gammelgaard, Lene; Jensen, Marie P.;

    2011-01-01

    The influence of various parameters on the spray-coating of thin films of poly(l-lactide) (PLLA) was investigated. The optimized processing conditions were used for deposition of the biodegradable polymer on arrays of SU-8 microcantilevers. The resonance frequency of the cantilevers before and af...

  7. Lifetime obtained by ion beam assisted deposition

    International Nuclear Information System (INIS)

    We have fabricated green organic light-emitting diodes based on tris-(8-hydroxyquinoline)aluminium (Alq3) thin films. In order to favor the charge carriers transport from the anode, we have deposited a N,N'-diphenyl-N,N'-bis (3-methylphenyl)-1,1'-diphenyl-4,4'-diamine (TPD) layer (hole transport layer) on a ITO anode. Cathode is obtained with a calcium layer covered with a silver layer. This silver layer is used to protect the other layers against oxygen during the OLED use. All the depositions are performed under vacuum and the devices are not exposed to air during their realisation. In order to improve the silver layer characteristics, we have realized this layer with the ion beam assisted deposition process. The aim of this process is to densify the layer and then reduce the permeation of H2O and O2. We have used argon ions to assist the silver deposition. All the OLEDs optoelectronic characterizations (I = f(V), L = f(V)) are performed in the ambient air. We compare the results obtained with the assisted layer with those obtained with a classical cathode realized by thermal unassisted evaporation. We have realized lifetime measurements in the ambient air and we discuss about the assisted layer influence on the OLEDs performances

  8. New Mexico Known Mineral Deposit Areas

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — This dataset contains all Known Mineral Deposit Areas in the state of New Mexico. It is in a vector digital structure digitized from a 1:500,000 scale map of the...

  9. Low-pressure, chemical vapor deposition polysilicon

    Science.gov (United States)

    Gallagher, B. D.; Crotty, G. C.

    1986-01-01

    The low-pressure chemical vapor deposition (LPCVD) of polycrystalline silicon was investigted. The physical system was described, as was the controlling process parameters and requirements for producing films for use as an integral portion of the solar cell contact system.

  10. Contaminant transport at a waste residue deposit

    DEFF Research Database (Denmark)

    Engesgaard, Peter Knudegaard; Traberg, Rikke

    1996-01-01

    Contaminant transport in an aquifer at an incinerator waste residue deposit in Denmark is simulated. A two-dimensional, geochemical transport code is developed for this purpose and tested by comparison to results from another code, The code is applied to a column experiment and to the field site...

  11. Atmosfærisk deposition 2000

    DEFF Research Database (Denmark)

    Ellermann, T.; Hertel, O.; Hovmand, M. F.;

    Denne rapport sammenfatter de vigtigste konklusioner fra dette års rapportering af atmosfæredelen af NOVA 2003 og opsummerer ovedresultaterne vedrørende måling og beregning af koncentrationer af atmosfæriske kvælstof-, fosfor-, svovlforbindelser og tungmetaller samt deposition til danske hav- og...... den største kvælstofdeposition, som hidtil er blevet rapporteret og ca. 20% højere end rapporteret for 1999 (Ellermann et al. 2000). For begge år viser de nyeste beregninger en tydeligt højere deposition til de danske farvande end hidtil rapporteret. Opdatering af model Det er vigtigt at bemærke, at...... den samlede deposition til de danske farvande, og dels højere kvælstofkoncentrationer i nedbøren. Denne forklaring underbygges af målingerne, som viser en svag stigning i våddepositionen fra 1999 til 2000 på trods af, at nedbørsmængden er lidt mindre i 2000 end 1999. Deposition opdelt på de...

  12. DRY DEPOSITION OF POLLUTANTS TO FORESTS

    Science.gov (United States)

    We report on the results of an extensive field campaign to measure dry deposition of ozone and sulfur dioxide to a sample of forest types in the United States. Measurements were made for full growing seasons over a deciduous forest in Pennsylvania and a mixed deciduous-conifer...

  13. Modeling of dust deposition in central Asia

    Science.gov (United States)

    The deposition of dust particles has a significant influence on the global bio-geochemical cycle. Currently, the lack of spatiotemporal data creates great uncertainty in estimating the global dust budget. To improve our understanding of the fate, transport and cycling of airborne dust, there is a ne...

  14. 28 CFR 68.22 - Depositions.

    Science.gov (United States)

    2010-07-01

    ... BEFORE ADMINISTRATIVE LAW JUDGES IN CASES INVOLVING ALLEGATIONS OF UNLAWFUL EMPLOYMENT OF ALIENS, UNFAIR IMMIGRATION-RELATED EMPLOYMENT PRACTICES, AND DOCUMENT FRAUD § 68.22 Depositions. (a) Notice. Any party... taken elsewhere, unless otherwise permitted by the Administrative Law Judge or agreed to by the...

  15. 37 CFR 1.25 - Deposit accounts.

    Science.gov (United States)

    2010-07-01

    ... COMMERCE GENERAL RULES OF PRACTICE IN PATENT CASES General Provisions Fees and Payment of Money § 1.25... account may be submitted by electronic funds transfer through the Federal Reserve Fedwire System, which... account number. (2) A payment to replenish a deposit account may be submitted by electronic funds...

  16. Panel 1 - comparative evaluation of deposition technologies

    Energy Technology Data Exchange (ETDEWEB)

    Fenske, G.R.; Stodolsky, F. [Argonne National Lab., IL (United States); Benson, D.K.; Pitts, R.J. [National Renewable Energy Lab., Golden, CO (United States); Bhat, D.G. [GTE Valenite Corp., Troy, MI (United States); Yulin Chen [Allison Gas Turbine Division, GM, Indianapolis, IN (United States); Gat, R.; Sunkara, M.K. [Case Western Reserve Univ., Cleveland, OH (United States); Kelly, M. [Stanford Univ., CA (United States); Lawler, J.E. [Univ. of Wisconsin, Madison (United States); Nagle, D.C. [Martin Marietta Labs., Baltimore, MD (United States); Outka, D. [Sandia National Laboratories, Livermore, CA (United States); Revankar, G.S. [Deere & Co., Moline, IL (United States); Subramaniam, V.V. [Ohio State Univ., Columbus (United States); Wilbur, P.J. [Colorado State Univ., Fort Collins (United States); Mingshow Wong [Northwestern Univ., Evanston, IL (United States); Woolam, W.E. [Southwest Research Inst., Arlington, VA (United States)

    1993-01-01

    This working group attempted to evaluate/compare the different types of deposition techniques currently under investigation for depositing diamond and diamond-like carbon films. A table lists the broad types of techniques that were considered for depositing diamond and diamond-like carbon films. After some discussion, it was agreed that any evaluation of the various techniques would be dependent on the end application. Thus the next action was to list the different areas where diamond and DLC films could find applications in transportation. These application areas are listed in a table. The table intentionally does not go into great detail on applications because that subject is dealt with specifically by Panel No. 4 - Applications To Transportation. The next action concentrated on identifying critical issues or limitations that need to be considered in evaluating the different processes. An attempt was then made to rank different broad categories of deposition techniques currently available or under development based on the four application areas and the limitations. These rankings/evaluations are given for diamond and DLC techniques. Finally, the working group tried to identify critical development and research issues that need to be incorporated into developing a long-term program that focuses on diamond/DLC coatings for transportation needs. 5 tabs.

  17. Stabilization of gravel deposits using microorganisms

    NARCIS (Netherlands)

    Van der Star, W.R.L.; Van Wijngaarden, W.K.; Van Paassen, L.A.; Van Baalen, L.R.; Zwieten, G.

    2011-01-01

    One of the techniques used for the construction of underground infrastructure is horizontal directional drilling (HDD). This trenchless method is complicated when crossing gravel deposits as a borehole in coarse gravel tends to collapse, causing the drill pipe to get stuck or the failure of installa

  18. Deposition Diagnostics for Next-step Devices

    Energy Technology Data Exchange (ETDEWEB)

    C.H. Skinner; A.L. Roquemore; the NSTX team; A. Bader; W.R. Wampler

    2004-06-15

    The scale-up of deposition in next-step devices such as ITER will pose new diagnostic challenges. Codeposition of hydrogen with carbon needs to be characterized and understood in the initial hydrogen phase in order to mitigate tritium retention and qualify carbon plasma facing components for DT operations. Plasma facing diagnostic mirrors will experience deposition that is expected to rapidly degrade their reflectivity, posing a new challenge to diagnostic design. Some eroded particles will collect as dust on interior surfaces and the quantity of dust will be strictly regulated for safety reasons - however diagnostics of in-vessel dust are lacking. We report results from two diagnostics that relate to these issues. Measurements of deposition on NSTX with 4 Hz time resolution have been made using a quartz microbalance in a configuration that mimics that of a typical diagnostic mirror. Often deposition was observed immediately following the discharge suggesting that diagnostic shutters should be closed as soon as possible after the time period of interest. Material loss was observed following a few discharges. A novel diagnostic to detect surface particles on remote surfaces was commissioned on NSTX.

  19. 31 CFR 223.4 - Deposits.

    Science.gov (United States)

    2010-07-01

    ... 31 Money and Finance: Treasury 2 2010-07-01 2010-07-01 false Deposits. 223.4 Section 223.4 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) FISCAL SERVICE, DEPARTMENT OF THE TREASURY FINANCIAL MANAGEMENT SERVICE SURETY COMPANIES DOING BUSINESS WITH THE UNITED...

  20. Iron and manganese deposits in Uruguay

    International Nuclear Information System (INIS)

    This report is the results of the study carried out for the United Nations expert which the main object was: the study of the information available about iron and manganese formation in Uruguay, as well as the main researching deposit to determinate economical possibilities in the exportation.

  1. Local plasma deposition on polymer components

    NARCIS (Netherlands)

    Bolt, P.J.; Theelen, M.J.; Habets, D.; Winands, G.J.J.; Staemmler, L.

    2011-01-01

    For the modification of the surface energy of polymers, organosilicon coatings provide good optical and mechanical properties and are excellent candidates for the modification of the surface energy of polymers. These coatings can be deposited by plasma polymerization of hexamethyldisiloxane (HMDSO)

  2. Atomic layer deposition of nanoporous biomaterials.

    Energy Technology Data Exchange (ETDEWEB)

    Narayan, R. J.; Adiga, S. P.; Pellin, M. J.; Curtiss, L. A.; Stafslien, S.; Chisholm, B.; Monteiro-Riviere, N. A.; Brigmon, R. L.; Elam, J. W.; Univ. of North Carolina; North Carolina State Univ.; Eastman Kodak Co.; North Dakota State Univ.; SRL

    2010-03-01

    Due to its chemical stability, uniform pore size, and high pore density, nanoporous alumina is being investigated for use in biosensing, drug delivery, hemodialysis, and other medical applications. In recent work, we have examined the use of atomic layer deposition for coating the surfaces of nanoporous alumina membranes. Zinc oxide coatings were deposited on nanoporous alumina membranes using atomic layer deposition. The zinc oxide-coated nanoporous alumina membranes demonstrated antimicrobial activity against Escherichia coli and Staphylococcus aureus bacteria. These results suggest that atomic layer deposition is an attractive technique for modifying the surfaces of nanoporous alumina membranes and other nanostructured biomaterials. Nanoporous alumina, also known as anodic aluminum oxide (AAO), is a nanomaterial that exhibits several unusual properties, including high pore densities, straight pores, small pore sizes, and uniform pore sizes. In 1953, Keller et al. showed that anodizing aluminum in acid electrolytes results in a thick layer of nearly cylindrical pores, which are arranged in a close-packed hexagonal cell structure. More recently, Matsuda & Fukuda demonstrated preparation of highly ordered platinum and gold nanohole arrays using a replication process. In this study, a negative structure of nanoporous alumina was initially fabricated and a positive structure of a nanoporous metal was subsequently fabricated. Over the past fifteen years, nanoporous alumina membranes have been used as templates for growth of a variety of nanostructured materials, including nanotubes, nanowires, nanorods, and nanoporous membranes.

  3. Deposition of nitrogen into the North Sea

    NARCIS (Netherlands)

    Leeuw, G.de; Ambelas Skjøth, C.; Hertel, O.; Jickells, T.; Spokes, L.; Vignati, E.; Frohn, L.; Frydendall, J.; Schulz, M.; Tamm, S.; Sørensen, L.L.; Kunz, G.J.

    2003-01-01

    The flux of nitrogen species from the atmosphere into the ocean, with emphasis on coastal waters, was addressed during the ANICE project (Atmospheric Nitrogen Inputs into the Coastal Ecosystem). ANICE focused on quantifying the deposition of atmospheric inputs of inorganic nitrogen compounds (HNO3,

  4. Manganese deposition in drinking water distribution systems.

    Science.gov (United States)

    Gerke, Tammie L; Little, Brenda J; Barry Maynard, J

    2016-01-15

    This study provides a physicochemical assessment of manganese deposits on brass and lead components from two fully operational drinking water distributions systems. One of the systems was maintained with chlorine; the other, with secondary chloramine disinfection. Synchrotron-based in-situ micro X-ray adsorption near edge structure was used to assess the mineralogy. In-situ micro X-ray fluorescence mapping was used to demonstrate the spatial relationships between manganese and potentially toxic adsorbed metal ions. The Mn deposits ranged in thickness from 0.01 to 400 μm. They were composed primarily of Mn oxides/oxhydroxides, birnessite (Mn(3+) and Mn(4+)) and hollandite (Mn(2+) and Mn(4+)), and a Mn silicate, braunite (Mn(2+) and Mn(4+)), in varying proportions. Iron, chromium, and strontium, in addition to the alloying elements lead and copper, were co-located within manganese deposits. With the exception of iron, all are related to specific health issues and are of concern to the U.S. Environmental Protection Agency (U.S. EPA). The specific properties of Mn deposits, i.e., adsorption of metals ions, oxidation of metal ions and resuspension are discussed with respect to their influence on drinking water quality.

  5. World Distribution of Uranium Deposits (UDEPO) with uranium deposit classification. 2009 ed

    International Nuclear Information System (INIS)

    The World Distribution of Uranium Deposits (UDEPO) database provides general, technical and geological information, including references, about the worldwide uranium deposits. UDEPO has been published on the internet which allows the users to register freely and to work with datasets (http://www-nfcis.iaea.org). The UDEPO web site is designed to allow users to retrieve data sets on a variety of deposit related topics ranging from specific information on individual uranium deposits to statistical information on uranium deposits worldwide. The basic building blocks for the UDEPO database are the more than 900 individual deposits for which information is available in the database. The database is arranged in a relational database format which has one main table and a number of associated tables. Structured nature of the database allows filtering and querying the database in more systematic way. The web site provides filtering and navigation to the data from the database. It has also a statistical tool which provides summary information on number of deposits and uranium resources by type and status, and by country and status. In this respect and with regard to the data presented, the UDEPO database is a unique database which provides freely accessible information on worldwide uranium deposits. Although a great effort is spent to have complete and accurate database, the users should take into consideration that there still might be missing or outdated data for individual deposits due to the rapid changes in the uranium industry due to the new exploration works which are ongoing everyday. This document and its supplementary CD-ROM represent a snapshot of the status of the database as of the end of 2008. However, the database is being continuously updated and the latest updates and additions can be accessed from the database web site (http://wwwnfcis.iaea.org)

  6. Atmospheric Deposition of Phosphorus to the Everglades: Concepts, Constraints, and Published Deposition Rates for Ecosystem Management

    Directory of Open Access Journals (Sweden)

    Garth W. Redfield

    2002-01-01

    Full Text Available This paper summarizes concepts underlying the atmospheric input of phosphorus (P to ecosystems, published rates of P deposition, measurement methods, and approaches to future monitoring and research. P conveyed through the atmosphere can be a significant nutrient source for some freshwater and marine ecosystems. Particle sources and sinks at the land-air interface produce variation in P deposition from the atmosphere across temporal and spatial scales. Natural plant canopies can affect deposition rates by changing the physical environment and surface area for particle deposition. Land-use patterns can alter P deposition rates by changing particle concentrations in the atmosphere. The vast majority of P in dry atmospheric deposition is conveyed by coarse (2.5 to 10 μm and giant (10 to 100 μm particles, and yet these size fractions represent a challenge for long-term atmospheric monitoring in the absence of accepted methods for routine sampling. Most information on P deposition is from bulk precipitation collectors and wet/dry bucket sampling, both with questionable precision and accuracy. Most published annual rates of P deposition are gross estimates derived from bulk precipitation sampling in locations around the globe and range from about 5 to well over 100 mg P m–2 year–1, although most inland ecosystems receive between 20 and 80 mg P m–2 year–1. Rates below 30 mg P m–2 year–1 are found in remote areas and near coastlines. Intermediate rates of 30 to 50 mg P m–2 year–1 are associated with forests or mixed land use, and rates of 50 to 100 mg P m–2 year–1 or more are often recorded from urban or agricultural settings. Comparison with other methods suggests that these bulk precipitation estimates provide crude boundaries around actual P deposition rates for various land uses. However, data screening cannot remove all positive bias caused by contamination of bucket or bulk collectors. As a consequence, continued sampling

  7. Deposition of diamond and boron nitride films by plasma chemical vapour deposition

    Energy Technology Data Exchange (ETDEWEB)

    Albella, J.M. [Universidad Autonoma, CSIC, Madrid (Spain). Inst. of Mater. Sci.; Gomez-Aleixandre, C. [Universidad Autonoma, CSIC, Madrid (Spain). Inst. of Mater. Sci.; Sanchez-Garrido, O. [Universidad Autonoma, CSIC, Madrid (Spain). Inst. of Mater. Sci.; Vazquez, L. [Universidad Autonoma, CSIC, Madrid (Spain). Inst. of Mater. Sci.; Martinez-Duart, J.M. [Universidad Autonoma, CSIC, Madrid (Spain). Inst. of Mater. Sci.

    1995-01-01

    The deposition problems of diamond and cubic boron nitride (c-BN) by chemical vapour deposition techniques are reviewed, with major emphasis on the nucleation and reaction mechanisms. A discussion is made of the main deposition parameters (i.e. gas mixture, substrate conditioning, plasma discharges etc.) which favour the formation of the cubic phase. Most of the work is devoted to diamond owing to the large progress attained in this material. In fact, the use of diamond as a hard protective coating is now on a commercial scale. By contrast, the preparation of c-BN layers with good characteristics still needs of further research. ((orig.))

  8. The Nopal 1 Uranium Deposit: an Overview

    Science.gov (United States)

    Calas, G.; Allard, T.; Galoisy, L.

    2007-05-01

    The Nopal 1 natural analogue is located in the Pena Blanca uranium district, about 50 kms north of Chihuahua City, Mexico. The deposit is hosted in tertiary ignimbritic ash-flow tuffs, dated at 44 Ma (Nopal and Colorados formations), and overlying the Pozos conglomerate formation and a sequence of Cretaceous carbonate rocks. The deposit is exposed at the ground surface and consists of a near vertical zone extending over about 100 m with a diameter of 40 m. An interesting characteristic is that the primary mineralization has been exposed above the water table, as a result of the uplift of the Sierra Pena Blanca, and subsequently oxidized with a remobilization of hexavalent uranium. The primary mineralization has been explained by various genetic models. It is associated to an extensive hydrothermal alteration of the volcanic tuffs, locally associated to pyrite and preserved by an intense silicification. Several kaolinite parageneses occur in fissure fillings and feldspar pseudomorphs, within the mineralized breccia pipe and the barren surrounding rhyolitic tuffs. Smectites are mainly developed in the underlying weakly welded tuffs. Several radiation-induced defect centers have been found in these kaolinites providing a unique picture of the dynamics of uranium mobilization (see Allard et al., this session). Another evidence of this mobilization is given by the spectroscopy of uranium-bearing opals, which show characteristic fluorescence spectra of uranyl groups sorbed at the surface of silica. By comparison with the other uranium deposits of the Sierra Pena Blanca and the nearby Sierra de Gomez, the Nopal 1 deposit is original, as it is one of the few deposits hving retained a reduced uranium mineralization.

  9. Mississippi Valley-Type Lead-Zinc Deposit Model

    Science.gov (United States)

    Leach, David L.; Taylor, Ryan D.

    2009-01-01

    Mississippi Valley-type (MVT) lead-zinc (Pb+Zn) deposits are found throughout the world, and these deposits are characteristically distributed over hundreds of square kilometers that define individual ore districts. The median size of individual MVT deposits is 7.0 million tonnes with grades of about 7.9 percent Pb+Zn metal. However, MVT deposits usually occur in extensive districts consisting of several to as many as 400 deposits. Nearly one-quarter of the world's sedimentary and volcanic rock-hosted Pb+Zn resources are found in these deposits, with by-product commodities including silver (Ag), copper (Cu), and indium (In) for some deposits. Environmentally, MVT deposits are less of a concern than other types of mineral deposits since the carbonate-host rocks mitigate many environmental concerns.

  10. Aerosol deposition in the human respiratory system. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Yu, C.P.

    1988-01-01

    Attempts were made to develop mathematical models for the deposition of aerosols in the human respiratory system. Expressions were obtained for the mean deposition efficiency for nasal inspiration, nasal expiration, and mouth inspiration. A determination was made of statistical properties associated with each deposition efficiency due to intersubject and intrasubject variabilities. Expressions were then derived for head deposition with combined nose and mouth breathing. In the lung, deposition is a result primarily of impaction, sedimentation, and diffusion. While there was no adequate model for impaction, several deposition formulae for sedimentation were derived as well as ones for diffusion. Studies were also made of the particle charge effect, as the electrostatic image force on a particle contributes to its deposition. There is, however, a threshold charge per particle below which the particle charge has no effect on deposition. Deposition data on ultrafine particles is scarce due to the difficulties in conducting proper experiments.

  11. Properties of electrodeposited amorphous Fe-Ni-W alloy deposits

    Institute of Scientific and Technical Information of China (English)

    HE Feng-jiao; WANG Miao; LU Xin

    2006-01-01

    A new technique of electroplating amorphous Fe-Ni-W alloy deposits was proposed. The structure and morphology of Fe-Ni-W alloy deposit were detected by XRD and SEM. The friction and wear behavior of Fe-Ni-W alloy deposit were studied and compared with that of chromium deposit. The corrosion properties against 5% sodium chloride, 5% sulfuric acid and 5% sodium hydroxide were also discussed. The experimental results indicate that Fe-Ni-W alloy deposits have superior properties against wear than hard chromium deposits under dry sliding condition. Under oil sliding condition, except their better wear resistance, the deposits can protect their counterparts against wear. The deposits plated on brass and AISI 1045 steel show good behavior against corrosion of 5% sodium chloride, 5% sulfuric acid and 5% sodium hydroxide. The bath of electroplating amorphous Fe-Ni-W alloy deposits is environmentally friendly and would find widely use in industry.

  12. Cobalt cluster-assembled thin films deposited by low energy cluster beam deposition: Structural and magnetic investigations of deposited layers

    International Nuclear Information System (INIS)

    Cobalt cluster-assembled thin films were deposited on amorphous-carbon-coated copper grids and on silicon substrates at room temperature by low energy cluster beam deposition. Characterizations using high-resolution transmission electronic microscopy and atomic force microscopy reveal randomly stacked agglomerates of 9-11 nm diameter, which are themselves composed of small 3.6 nm diameter fcc cobalt clusters. The films are ferromagnetic up to room temperature and above, which implies that the clusters are exchange coupled. The approach to saturation is analyzed within the random anisotropy model. The values of the exchange coefficient A and the anisotropy constant K then derived are discussed. The temperature dependence of the coercivity below 100 K is discussed in terms of thermal activation effects. All results indicate that the fundamental entity governing the magnetic behaviors is constituted by the 9-11 nm diameter agglomerates rather than by the clusters themselves

  13. Electrochemical deposition and characterization of zinc–nickel alloys deposited by direct and reverse current

    Directory of Open Access Journals (Sweden)

    JELENA B. BAJAT

    2005-12-01

    Full Text Available Zn–Ni alloys electrochemically deposited on steel under various deposition conditions were investigated. The alloys were deposited on a rotating disc electrode and on a steel panel from chloride solutions by direct and reverse current. The influence of reverse plating variables (cathodic and anodic current densities and their time duration on the composition, phase structure and corrosion properties were investigated. The chemical content and phase composition affect the anticorrosive properties of Zn–Ni alloys during exposure to a corrosive agent (3 % NaCl solution. It was shown that the Zn–Ni alloy electrodeposited by reverse current with a full period T = 1 s and r = 0.2 exhibits the best corrosion properties of all the investigated alloys deposited by reverse current.

  14. Gigantic landslides versus glacial deposits: on origin of large hummock deposits in Alai Valley, Northern Pamir

    Science.gov (United States)

    Reznichenko, Natalya

    2015-04-01

    As glaciers are sensitive to local climate, their moraines position and ages are used to infer past climates and glacier dynamics. These chronologies are only valid if all dated moraines are formed as the result of climatically driven advance and subsequent retreat. Hence, any accurate palaeoenvironmental reconstruction requires thorough identification of the landform genesis by complex approach including geomorphological, sedimentological and structural landform investigation. Here are presented the implication of such approach for the reconstruction of the mega-hummocky deposits formation both of glacial and landslide origin in the glaciated Alai Valley of the Northern Pamir with further discussion on these and similar deposits validity for palaeoclimatic reconstructions. The Tibetan Plateau valleys are the largest glaciated regions beyond the ice sheets with high potential to provide the best geological record of glacial chronologies and, however, with higher probabilities of the numerous rock avalanche deposits including those that were initially considered of glacial origin (Hewitt, 1999). The Alai Valley is the largest intermountain depression in the upper reaches of the Amudarja River basin that has captured numerous unidentified extensive hummocky deposits descending from the Zaalai Range of Northern Pamir, covering area in more than 800 km2. Such vast hummocky deposits are usually could be formed either: 1) glacially by rapid glacial retreat due to the climate signal or triggered a-climatically glacial changes, such as glacial surge or landslide impact, or 2) during the landslide emplacement. Combination of sediment tests on agglomerates forming only in rock avalanche material (Reznichenko et al., 2012) and detailed geomorphological and sedimentological descriptions of these deposits allowed reconstructing the glacial deposition in the Koman and Lenin glacial catchments with identification of two gigantic rock avalanches and their relation to this glacial

  15. Heavy metal deposition mapping: concentrations and deposition of heavy metals in rural areas of the UK

    OpenAIRE

    Malcolm, Heath; Fowler, David; Crossley, Alan; Kentisbeer, John; Hallsworth, Steve; Lawlor, Alan; Rowland, Phil; Guyatt, Hayley; Beith, Sarah; Thacker, Sarah; Halford, Alan; ROGERS Stuart; Cape, J. Neil; Leeson, Sarah; Harmens, Harry

    2012-01-01

    CEH has been monitoring the concentrations of a range of heavy metals in rural locations across the UK since 2004. This report presents the annual average concentrations and deposition of heavy metals in air and rainfall samples collected from rural locations during 2011 and it reviews the temporal and spatial trends in heavy metal concentrations and deposition between 2004 and 2011. The monitoring network was established to measure the background concentration of a range of heavy meta...

  16. Factors influencing chloride deposition in a coastal hilly area and application to chloride deposition mapping

    Directory of Open Access Journals (Sweden)

    H. Guan

    2009-09-01

    Full Text Available Chloride is commonly used as an environmental tracer for studying water flow and solute transport in the environment. It is especially useful for estimating groundwater recharge based on the commonly used chloride mass balance (CMB method. Strong spatial variability in chloride deposition in coastal areas is one difficulty encountered in appropriately applying the CMB approach. Furthermore, intensive vegetation clearance for agriculture, for example during the European settlement in many coastal areas of Australia, may have perturbed catchment chloride balance conditions for appropriate use in CMB applications. In order to deal with these issues, a high resolution chloride deposition map in the coastal region is needed. In this study, we examined geographic, orographic, and atmospheric factors influencing chloride deposition in the Mount Lofty Ranges (MLR, a coastal hilly area of approximately 9000 km2 spatial extent in South Australia, using partial correlation and regression analyses. The results indicate that coastal distance, and terrain aspect and slope are two most significant factors controlling chloride deposition. Coastal distance accounts for 65% spatial variability in chloride deposition, with terrain aspect and slope for 8%. The deposition gradient is about 0.08 gm-2 year-1 km-1 as one progresses inland. The results are incorporated into a published de-trended residual kriging approach (ASOADeK to produce a 1 km×1 km resolution annual chloride deposition map and a bulk precipitation chloride concentration map. The average uncertainty of the deposition map is about 30% in the western MLR, and over 50% in the eastern MLR. The maps will form a very useful basis for examining catchment chloride balances for use in the CMB application in the study area.

  17. Iridium thin films deposited via pulsed laser deposition for future applications as transition-edge sensors

    Energy Technology Data Exchange (ETDEWEB)

    Galeazzi, M. E-mail: galeazzi@physics.miami.edu; Chen, C.; Cohn, J.L.; Gundersen, J.O

    2004-03-11

    The University of Miami has recently started developing and studying high-resolution microcalorimeters operating near 100 mK for X-ray and particle physics and astrophysics. These detectors will be based on Transition Edge Sensors technology fabricated using iridium thin films deposited via the Pulsed Laser Deposition technique. We report here the preliminary result of the room temperature characterization of the Ir thin films, and an overview of future plans to use the films as transition edge sensors.

  18. Atmospheric Deposition of Phosphorus to the Everglades: Concepts, Constraints, and Published Deposition Rates for Ecosystem Management

    OpenAIRE

    Redfield, Garth W.

    2002-01-01

    This paper summarizes concepts underlying the atmospheric input of phosphorus (P) to ecosystems, published rates of P deposition, measurement methods, and approaches to future monitoring and research. P conveyed through the atmosphere can be a significant nutrient source for some freshwater and marine ecosystems. Particle sources and sinks at the land-air interface produce variation in P deposition from the atmosphere across temporal and spatial scales. Natural plant canopies can affect depos...

  19. Oxygen Barrier Coating Deposited by Novel Plasma-enhanced Chemical Vapor Deposition

    DEFF Research Database (Denmark)

    Jiang, Juan; Benter, M.; Taboryski, Rafael Jozef;

    2010-01-01

    We report the use of a novel plasma-enhanced chemical vapor deposition chamber with coaxial electrode geometry for the SiOx deposition. This novel plasma setup exploits the diffusion of electrons through the inner most electrode to the interior samples space as the major energy source. This confi...... increased the barrier property of the modified low-density polyethylene, polyethylene terephthalate, and polylactide by 96.48%, 99.69%, and 99.25%, respectively....

  20. Uranium deposits of Gabon and Oklo reactors. Metallogenic model for rich deposits of the lower proterozoic

    International Nuclear Information System (INIS)

    The geology of the Franceville basin (Gabon) is examined: stratigraphy, tectonics and geodynamics. The mobile zone of the Ogooue is specially studied: lithology, metamorphism and tectonics, isotopic geochronologic data are given. The different uranium deposits are described. A whole chapter is devoted to the study of Oklo natural nuclear reactor. A metallogenic model is proposed evidencing conditions required for deposit genesis. Tectonics, microstructures sedimentology, organic matter, diagenesis and uraniferous mineralizations are examined

  1. Deposition of metal oxide films and nanostructures by methods derived from photochemical metal organic deposition

    OpenAIRE

    Xin ZHANG

    2009-01-01

    In this research, methods for the deposition of patterned films and nanostructures were developed from photochemical metal organic deposition (PMOD). Positive lithographic PMOD was demonstrated with films of titanium (IV) di-n-butoxide bis(2-ethylhexanoate) (Ti(OBun)2(eh)2), titanium (IV) diisopropoxide bis(2,4-pentanedionate), and zirconium (IV) di-n-butoxide bis(2,4-pentanedionate). The photochemistry of these complexes in films was studied by FTIR, AES, and XRD. Photo-induced reactivity an...

  2. Seismic stratigraphy and depositional history of late Quaternary deposits in the Yellow Sea.

    Science.gov (United States)

    Lee, Gwang-Soo; Yoo, Dong Geun; Bae, Sungho; Choul Kim, Dae; Yi, Hi-Il

    2016-04-01

    To identify the seismic stratigraphy and depositional history of late Quaternary deposits in the Yellow Sea, approximately 52,600 line-km of Chirp seismic profiles and 5,060 line-km of Sparker seismic profiles were analyzed. The Yellow Sea are correspond to three sedimentary environments: (1) a various scale sand ridges/waves and mud belt (the western inner-shelf of the Korean Peninsula), (2) recent- and paleo-channels, erosional and broad surface (the center of the Yellow Sea), and (3) prodelta mud patch (the eastern offshore of China). Based on the seismic stratigraphic analysis of seismic profiles, the late Quaternary deposits in the Yellow Sea are divided into five distinctive seismic units (units CY1~5), consisting of two depositional sequences that can be defined as erosional and disconformable strata. Each unit show different seismic facies and geometry, and is clearly separated by each bounding surface. The major depositional processes and sediment dispersal systems during the late Quaternary in the Yellow Sea are: (1) regressive estuarine/deltaic deposits (unit CY1), (2) transgressive incised channel fill (unit CY2), (3) transgressive sand sheet (unit CY3), (4) transgressive sand ridges (unit CY4), and (5) prodelta/recent mud (unit CY5). The depositional sequences follow the general concepts of sequence stratigraphy very well. Lower sequence (DI) correspond to the falling stage systems tract regarded as regressive estuarine or deltaic deposits (unit CY1), whereas upper sequence (DII) consists of a set of the transgressive (units CY2, CY3, and CY4) and highstand systems tract (unit CY5) formed since the last-glacial period.

  3. Factors influencing chloride deposition in a coastal hilly area and application to chloride deposition mapping

    OpenAIRE

    H. Guan; Love, A. J.; C. T. Simmons; Makhnin, O.; A. S. Kayaalp

    2010-01-01

    Chloride is commonly used as an environmental tracer for studying water flow and solute transport in the environment. It is especially useful for estimating groundwater recharge based on the commonly used chloride mass balance (CMB) method. Strong spatial variability in chloride deposition in coastal areas is one difficulty encountered in appropriately applying the method. A high-resolution bulk chloride deposition map in the coastal region is thus needed. The aim of this study is to construc...

  4. Factors influencing chloride deposition in a coastal hilly area and application to chloride deposition mapping

    OpenAIRE

    H. Guan; Love, A. J.; C. T. Simmons; Makhnin, O.; A. S. Kayaalp

    2010-01-01

    Chloride is commonly used as an environmental tracer for studying water flow and solute transport in the environment. It is especially useful for estimating groundwater recharge based on the commonly used chloride mass balance (CMB) method. Strong spatial variability in chloride deposition in coastal areas is one difficulty encountered in appropriately applying the method. A high-resolution bulk chloride deposition map in the coastal region is thus needed. The aim of this st...

  5. Advance in research on aerosol deposition simulation methods

    International Nuclear Information System (INIS)

    A comprehensive analysis of the health effects of inhaled toxic aerosols requires exact data on airway deposition. A knowledge of the effect of inhaled drugs is essential to the optimization of aerosol drug delivery. Sophisticated analytical deposition models can be used for the computation of total, regional and generation specific deposition efficiencies. The continuously enhancing computer seem to allow us to study the particle transport and deposition in more and more realistic airway geometries with the help of computational fluid dynamics (CFD) simulation method. In this article, the trends in aerosol deposition models and lung models, and the methods for achievement of deposition simulations are also reviewed. (authors)

  6. A Pyroclastic Flow Deposit on Venus

    Science.gov (United States)

    Ghail, R.; Wilson, L.

    2013-12-01

    Explosive volcanism on Venus is severely inhibited by its high atmospheric pressure and lack of water. This paper shows that a deposit located near 16°S, 144°E, here referred to as Scathach Fluctus, displays a number of morphological characteristics consistent with a pyroclastic flow deposit. These characteristics, particularly its lack of channelisation and evidence for momentum rather than cooling limited flow length, contrast with fissure-fed lava flow deposits. The total erupted volume is estimated to have been between 225 km3 and 875 km3 but this may have been emplaced in more than one event. Interaction between Scathach Fluctus and a small volcanic cone constrain the flow velocity to 48 m s-1 and plausible volatile concentrations to at least 1.8 wt% H2O, 4.3 wt% CO2 or 6.1 wt% SO2, the latter two implying magma sourced directly from the mantle. The deposit has radar characteristics, particularly an exponential backscatter function, that are similar to those of nearly half the planetary surface, implying that pyroclastic deposits may be much more common on Venus than has been recognised to date, and suggesting both a relatively volatile-rich mantle and a volcanic source for atmospheric SO2. Unfortunately, because the plains usually lack clear flow boundaries and structures, the features diagnostic of a high momentum flow - linear undulating deposits that lack channel morphology, cross narrow graben without deviation, climb obstacles and show evidence for parabolic flow out from steep drops - may not be identifiable. Thus, while pyroclastic flows may be common on Venus, Scathach Fluctus may, indeed, become the only proven example from Magellan data. False colour image of Scathach Fluctus using data from Cycle 1 (left-looking), Cycle 2 (right-looking) and passive emissivity combined to enhance the impression of relief in the grey scale image, overlain with colour-coded derived asperity height, defined as surface roughness at the scale-length of the Magellan

  7. Experimental measurements of the thermal conductivity of ash deposits: Part 2. Effects of sintering and deposit microstructure

    Energy Technology Data Exchange (ETDEWEB)

    A. L. Robinson; S. G. Buckley; N. Yang; L. L. Baxter

    2000-04-01

    The authors report results from an experimental study that examines the influence of sintering and microstructure on ash deposit thermal conductivity. The measurements are made using a technique developed to make in situ, time-resolved measurements of the effective thermal conductivity of ash deposits formed under conditions that closely replicate those found in the convective pass of a commercial boiler. The technique is designed to minimize the disturbance of the natural deposit microstructure. The initial stages of sintering and densification are accompanied by an increase in deposit thermal conductivity. Subsequent sintering continues to densify the deposit, but has little effect on deposit thermal conductivity. SEM analyses indicates that sintering creates a layered deposit structure with a relatively unsintered innermost layer. They hypothesize that this unsintered layer largely determines the overall deposit thermal conductivity. A theoretical model that treats a deposit as a two-layered material predicts the observed trends in thermal conductivity.

  8. Vacuum deposition of stoichiometric crystalline PbS films: The effect of sulfurizing environment during deposition

    Science.gov (United States)

    Singh, B. P.; Kumar, R.; Kumar, A.; Tyagi, R. C.

    2015-10-01

    Thin film of lead sulfide (PbS) was deposited onto highly cleaned glass and quartz substrates using a vacuum thermal evaporation technique. The effect of the sulfurizing environment on the growth and properties of vacuum-deposited PbS thin film was studied. The ambient sulfurizing environment was created by thermal decomposition of thiourea inside the vacuum chamber during deposition to maintain the stoichiometry and quality of the PbS film. The sulfurizing gas H2S, produced in the thermal decomposition of the solid sulfur containing thiourea readily combines with the cations (Pb2+) without leaving any anions (S2-) at the substrates and also has not produced any excess of sulfur at the substrates. The deposited film was characterized by optical spectroscopy, x-ray diffraction patterns, scanning electron micrographs with energy dispersive analysis of x-rays, and atomic force micrographs. The physical characterization of the deposited PbS film revealed that the surface of film grown in the sulfurizing environment improved and contained more stoichiometric sulfur in comparison to film deposited without the sulfurizing environment.

  9. Deposition of Cu seed layer film by supercritical fluid deposition for advanced interconnects

    Institute of Scientific and Technical Information of China (English)

    Zhao Bin; Zhao Ming-Tao; Zhang Yan-Fei; Yang Jun-He

    2013-01-01

    The deposition of a Cu seed layer film is investigated by supercritical fluid deposition (SCFD) using H2 as a reducing agent for Bis(2,2,6,6-tetramethyl-3,5-heptanedionato) copper in supercritical CO2 (scCO2).The effects of deposition temperature,precursor,and H2 concentration are investigated to optimize Cu deposition.Continuous metallic Cu films are deposited on Ru substrates at 190 ℃ when a 0.002 mol/L Cu precursor is introduced with 0.75 mol/L H2.A Cu precursor concentration higher than 0.002 mol/L is found to have negative effects on the surface qualities of Cu films.For a H2concentration above 0.56 mol/L,the root-mean-square (RMS) roughness of a Cu film decreases as the H2 concentration increases.Finally,a 20-nm thick Cu film with a smooth surface,which is required as a seed layer in advanced interconnects,is successfully deposited at a high H2 concentration (0.75 mol/L).

  10. Metallogenic evolution of uranium deposits in the Middle East and North Africa deposits

    Science.gov (United States)

    Howari, Fares; Goodell, Philip; Salman, Abdulaty

    2016-02-01

    This paper is briefly involved in classification and distributions of the Middle East and North Africa (MENA) uranium deposits. The study of these mineral systems can significantly contribute to our further understanding of the metallogeny of known and poorly explored deposits. This provides contribution to, and further enhancement of, current classifications and metallogenic models of uranium systems, allowing researchers to emphasize on unknown or poorly studied mineral systems found in MENA. The present study identified eight metallogenic types of uranium associated with: 1) the Archean rocks and intra-cratonic basins, 2) the Pan-African granites and rhyolites which are characterized by igneous activity, 3) Phanerozoic (Paleozoic) clastics, these deposits are the sedimentological response to Pan African magmatism, 4) Mesozoic (basal) clastics type e.g. Nubia sandstones which are characterized by uranium minerals, 5) regional sedimentary phosphate deposits which are categorized as geosynclinal, or continental margin deposits, on the shelf of the Tethys Ocean, 6) Cenozoic Intracratonic Felsic Magmatism of the Tibesti and Hoggar, and the sandstone U deposits of adjoining Niger. These are similar to the Pan-African magmatism metallogenic, 7) Calcretes, and 8) Resistate minerals which are often enriched in rare earth elements, sometimes including uranium. They are thus sometimes considered as U resources but poorly explored in the MENA region. These metallogenic types are described and discussed in the current paper.

  11. Deposition from wax-solvent mixtures under turbulent flow : effects of shear rate and time on deposit properties

    Energy Technology Data Exchange (ETDEWEB)

    Tiwary, R.; Mehrotra, A.K. [Calgary Univ., AB (Canada). Dept. of Chemical and Petroleum Engineering

    2008-07-01

    The effects of deposition time and shear rate on the deposition of solids was investigated under turbulent flow, for solutions of a multi-component wax in a paraffinic solvent. The deposition experiments were performed in a bench-scale flow-loop apparatus, incorporating a co-current double-pipe heat exchanger. The experiment involved 2 mixture compositions (10 and 15 mass per cent wax) at Reynolds numbers between 9000 and 27000 over a range of deposition times from 30 min to 24 h. The study showed that the deposit mass decreased with an increase in the Reynolds number, but it increased asymptotically with the deposition time. The deposit mass and density data were analyzed using a pseudo-steady-state heat transfer model to study the variation in the deposit-layer thickness and thermal conductivity with shear rate and deposition time. According to the GC analysis of deposit samples, there were noticeable changes in the carbon-number-distribution with shear rate and time. The variations in deposit properties were also assessed using a recently proposed model involving one-dimensional cubical-cage deformation. These study results provide evidence that deposition from waxy crude oils is mainly a thermally-driven process, in which the shear stress and the deposition time play significant roles by influencing the deposit properties. 4 refs.

  12. Aluminium phosphate sulphate minerals (APS) associated with proterozoic unconformity-type uranium deposits: crystal-chemical characterisation and petrogenetic significance; Les sulfates phosphates d'aluminium hydrates (APS) dans l'environnement des gisements d'uranium associes a une discordance proterozoique: caracterisation cristallochimique et signification petrogenetique

    Energy Technology Data Exchange (ETDEWEB)

    Gaboreau, St

    2005-07-01

    Aluminium phosphate sulfate minerals (APS) are particularly widespread and spatially associated with hydrothermal clay alteration in both the East Alligator River Uranium Field (Northern Territory, Australia) and the Athabasca basin (Saskatchewan, Canada), in the environment of proterozoic unconformity-related uranium deposits (URUD). The purpose of this study is both: 1) to characterize the nature and the origin of the APS minerals on both sides of the middle proterozoic unconformity between the overlying sandstones and the underlying metamorphic basement rocks that host the uranium ore bodies, 2) to improve our knowledge on the suitability of these minerals to indicate the paleo-conditions (redox, pH) at which the alteration processes relative to the uranium deposition operated. The APS minerals result from the interaction of oxidising and relatively acidic fluids with aluminous host rocks enriched in monazite. Several APS-bearing clay assemblages and APS crystal-chemistry have also been distinguished as a function of the distance from the uranium ore bodies or from the structural discontinuities which drained the hydrothermal solutions during the mineralisation event. One of the main results of this study is that the index mineral assemblages, used in the recent literature to describe the alteration zones around the uranium ore bodies, can be theoretically predicted by a set of thermodynamic calculations which simulate different steps of fluid-rock interaction processes related to a downward penetrating of hyper-saline, oxidizing and acidic diagenetic fluids through the lower sandstone units of the basins and then into the metamorphic basement rocks. The above considerations and the fact that APS with different crystal-chemical compositions crystallized in a range of fO{sub 2} and pH at which uranium can either be transported in solution or precipitated as uraninite in the host-rocks make these minerals not only good markers of the degree of alteration of the

  13. Paraffin wax deposits and chemical inhibitors

    Energy Technology Data Exchange (ETDEWEB)

    Mendell, J.L.

    1970-01-01

    Solutions to this problem becomes necessary with the advent of extremely deep production, offshore production, and the probability of ocean-floor completions. The reasons for paraffin-wax accumulations are many and difficult to pinpoint. Inhibition of these paraffin deposits appears to be the best solution. Paraffin solvents and inhibitors are as follows: solvents, wetting agents, dispersants, and crystal modifiers. Solvents are effective, but can harm a refinery catalyst and create health hazards. Wetting agents and dispersants comprise the majority of chemicals used as paraffin wax inhibitors. Crystal modifiers are relatively new and may provide the most efficient means of reducing deposition. Evaluations of chemical paraffin inhibitors are outlined. Field test results which consider the various chemicals tested may give satisfactory results in determining which particular chemical can solve the problem of the particular situation. (38 refs.)

  14. Strategic metal deposits of the Arctic Zone

    Science.gov (United States)

    Bortnikov, N. S.; Lobanov, K. V.; Volkov, A. V.; Galyamov, A. L.; Vikent'ev, I. V.; Tarasov, N. N.; Distler, V. V.; Lalomov, A. V.; Aristov, V. V.; Murashov, K. Yu.; Chizhova, I. A.; Chefranov, R. M.

    2015-11-01

    Mineral commodities rank high in the economies of Arctic countries, and the status of mineral resources and the dynamics of their development are of great importance. The growing tendency to develop strategic metal resources in the Circumarctic Zone is outlined in a global perspective. The Russian Arctic Zone is the leading purveyor of these metals to domestic and foreign markets. The comparative analysis of tendencies in development of strategic metal resources of the Arctic Zone in Russia and other countries is crucial for the elaboration of trends of geological exploration and research engineering. This paper provides insight into the development of Arctic strategic metal resources in global perspective. It is shown that the mineral resource potential of the Arctic circumpolar metallogenic belt is primarily controlled by large and unique deposits of nonferrous, noble, and rare metals. The prospective types of economic strategic metal deposits in the Russian Arctic Zone are shown.

  15. Deposited low temperature silicon GHz modulator

    CERN Document Server

    Lee, Yoon Ho Daniel; Lipson, Michal

    2013-01-01

    The majority of silicon photonics is built on silicon-on-insulator (SOI) wafers while the majority of electronics, including CPUs and memory, are built on bulk silicon wafers, limiting broader acceptance of silicon photonics. This discrepancy is a result of silicon photonics's requirement for a single-crystalline silicon (c-Si) layer and a thick undercladding for optical guiding that bulk silicon wafers to not provide. While the undercladding problem can be partially addressed by substrate removal techniques, the complexity of co-integrating photonics with state-of-the-art transistors and real estate competition between electronics and photonics remain problematic. We show here a platform for deposited GHz silicon photonics based on polycrystalline silicon with high optical quality suitable for high performance electro-optic devices. We demonstrate 3 Gbps polysilicon electro-optic modulator fabricated on a deposited polysilicon layer fully compatible with CMOS backend integration. These results open up an arr...

  16. Electrophoretically-deposited solid film lubricants

    Energy Technology Data Exchange (ETDEWEB)

    Dugger, M.T.; Panitz, J.K.J.; Vanecek, C.W.

    1995-04-01

    An aqueous-based process that uses electrophoresis to attract powdered lubricant in suspension to a charged target was developed. The deposition process yields coatings with low friction, complies with environmental safety regulations, requires minimal equipment, and has several advantages over processes involving organic binders or vacuum techniques. This work focuses on development of the deposition process, includes an analysis of the friction coefficient of the material in sliding contact with stainless steel under a range of conditions, and a functional evaluation of coating performance in a precision mechanical device application. Results show that solid lubricant films with friction coefficients as low as 0.03 can be produced. A 0.03 friction coefficient is superior to solid lubricants with binder systems and is comparable to friction coefficients generated with more costly vacuum techniques.

  17. Initial Stable State of Ocean Floor Deposits

    Institute of Scientific and Technical Information of China (English)

    洪振舜; 石名磊

    2004-01-01

    Extensive oedometer tests and physical tests have been conducted on remolded and reconstituted marine soils with different initial water contents and liquid limits. The oedometer test data can be well fitted with a straight line in the bilogarithmio ln(1 + e) ~ lg p plot. The initial effective stress corresponding to the initial void ratilo is determined by extrapolation of the bilogarithmic compression line. This new way of extrapolating oedometer test data to the initial void ratio overcomes the difficulty of measuring the residual effective stress of soils in the remolded state. The initial stable compression line of ocean floor deposits under different deposition environments corresponds to the compression line at the sensitivity equal to one. This initial stable compression line obtained in this study is consistent with the available compression line at the sensitivity equal to one which is proposed based on the experimental data of remolded undrained strengtl and the theoretical concept of Cam-clay critical state line.

  18. Nanosecond laser ablation and deposition of silicon

    Energy Technology Data Exchange (ETDEWEB)

    Siew, Wee Ong; Tou, Teck Yong [Multimedia University, Faculty of Engineering, Cyberjaya, Selangor (Malaysia); Yap, Seong Shan; Reenaas, Turid Worren [Norwegian University of Science and Technology, Department of Physics, Trondheim (Norway); Ladam, Cecile; Dahl, Oeystein [SINTEF Materials and Chemistry, Trondheim (Norway)

    2011-09-15

    Nanosecond-pulsed KrF (248 nm, 25 ns) and Nd:YAG (1064 nm, 532 nm, 355 nm, 5 ns) lasers were used to ablate a polycrystalline Si target in a background pressure of <10{sup -4} Pa. Si films were deposited on Si and GaAs substrates at room temperature. The surface morphology of the films was characterized using scanning electron microscopy (SEM) and atomic force microscopy (AFM). Round droplets from 20 nm to 5 {mu}m were detected on the deposited films. Raman Spectroscopy indicated that the micron-sized droplets were crystalline and the films were amorphous. The dependence of the properties of the films on laser wavelengths and fluence is discussed. (orig.)

  19. Protein Data Bank Depositions from Synchrotron Sources

    International Nuclear Information System (INIS)

    A survey and analysis of Protein Data Bank (PDB) depositions from international synchrotron radiation facilities, based on the latest released PDB entries, are reported. The results () show that worldwide, every year since 1999, more than 50% of the deposited X-ray structures have used synchrotron facilities, reaching 75% by 2003. In this web-based database, all PDB entries among individual synchrotron beamlines are archived, synchronized with the weekly PDB release. Statistics regarding the quality of experimental data and the refined model for all structures are presented, and these are analysed to reflect the impact of synchrotron sources. The results confirm the common impression that synchrotron sources extend the size of structures that can be solved with equivalent or better quality than home sources

  20. Electrochemical Behaviour of Sputtering Deposited DLC Films

    Institute of Scientific and Technical Information of China (English)

    LIUErjia; ZENGA; LIULX

    2003-01-01

    Diamondlike carbon (DLC) films were deposited via magnetron sputtering process. The energetic ion hombardment on the surface of growing film is one of the major parameters that control the atom mobility on the flirt1 surface and further the physical and chemical characteristics of the films. In this study, the energy of carbon ions was monitored by changing sputtering powerdensity, and its effect on the electrochemical performance of the films was investigated. For the deposition at a higher sputtering power density, a higher sp3 content in the DLC films was achieved with denser structure and increased film-substrate adhesion. The impedance at the interface of Si substrate/sulfufic acid solution was significantly enhanced, and at the same time higher film resistance, lower capacitance, higher breakdown potential and longer breakdown time were observed, which were related to the significant sp3 content of the DLC films.

  1. Electrochemical Behaviour of Sputtering Deposited DLC Films

    Institute of Scientific and Technical Information of China (English)

    LIU Erjia; ZENG A,LIU L X

    2003-01-01

    Diamondlike carbon (DLC) films were deposited via magnetron sputtering process. The energetic ion bombardment on the surface of growing film is one of the major parameters that control the atom mobility on the film surface and further the physical and chemical characteristics of the films. In this study, the energy of carbon ions was monitored by changing sputtering power density, and its effect on the electrochemical performance of the films was investigated. For the deposition at a higher sputtering power density, a higher sp3 content in the DLC films was achieved with denser structure and increased film-substrate adhesion. The impedance at the interface of Si substrate/sulfuric acid solution was significantly enhanced, and at the same time higher film resistance, lower capacitance, higher breakdown potential and longer breakdown time were observed, which were related to the significant sp3 content of the DLC films.

  2. Post deposition purification of PTCDA thin films

    International Nuclear Information System (INIS)

    The decomposition of perylene-3,4,9,10-tetracarboxylic dianhydride (PTCDA) molecules during evaporation of unpurified raw material in ultra high vacuum was studied. The fragments were identified by mass spectrometry and the influence of these fragments and further contaminations of the raw material on the electronic structure of PTCDA thin films was measured by photoemission spectroscopy. Annealing of contaminated PTCDA films was tested as cheap and easy to perform method for (partial) post deposition purification of the contaminated films

  3. Chemical Vapour Deposition of Large Area Graphene

    OpenAIRE

    Larsen, Martin Benjamin Barbour Spanget; Bøggild, Peter; Booth, Tim; Jørgensen, Anders Michael

    2015-01-01

    Chemical Vapor Deposition (CVD) is a viable technique for fabrication of large areas of graphene. CVD fabrication is the most prominent and common way of fabricating graphene in industry. In this thesis I have attempted to optimize a growth recipe and catalyst layer for CVD fabrication of uniform, single layer, and high carrier mobility large area graphene. The main goals of this work are; (1) explore the graphene growth mechanics in a low pressure cold-wall CVD system on a copper substrate, ...

  4. Flowslide Early Warning System in pyroclastic deposits

    Science.gov (United States)

    Olivares, Lucio; Damiano, Emila; De Cristofaro, Martina; Roberto, Greco; Mollo, Luigi; Netti, Nadia; Capparelli, Giovanna

    2015-04-01

    Most of the mountains of Campania are covered by airfall pyroclastic deposits in primary deposition generally in unsaturated conditions. These deposits are periodically subjected to rainfall induced landslides that may evolve into catastrophic flowslides. To protect towns EWS can be implemented in order to correctly and promptly predict the trigger. In the paper we detect some 'essential ingredients' for effective EWSs which are new with respect to those already employed and essentially based on pluviometric thresholds (Greco et. Al., 2013) and extremely simplified models not able to correctly follow the physical phenomena which are responsible of flowslides generation (Olivares et Al. 2009). Complex models, able to correctly simulate those physical phenomena such as infiltration processes and the effects of partial saturated conditions on shear strength contain the 'essential ingredients' that we discuss in the paper. A particular attention is devoted to define the relation between suction and shear strength and the water retention curve obtained from different techniques to assess a reliable hydro-geotechnical model to analyze the slope response of loose unsaturated pyroclastic deposits. An EWS that contains these elements can provide many advantages. In fact, catastrophic flowslides but even false alarms about such events, produce negative technological and productive shocks that strongly reduce the actual and prospective value added of investment in the areas at risk suggesting the opportunity of their shrinking and postponement. Of course this severely compromises the economic development of those areas. In the paper we propose to examine this subject in the Dixit e Pindyck framework of the Real Option Valuation Approach in order to explain the socio-economic value of effective EWS. In fact, such EWSs will embed valuable new real options in the investment opportunities in the areas at risk increasing their actual and prospective values. Keywords: slope

  5. Mixing from below in hydrothermal ore deposits

    Science.gov (United States)

    Bons, Paul D.; Gomez-Rivas, Enrique; Markl, Gregor; Walter, Bejamin

    2014-05-01

    Unconformity-related hydrothermal ore deposits typically show indications of mixing of two end-member fluids: (a) hot, deep, rock-buffered basement brines and (b) colder fluids derived from the surface or overlying sediments. The hydromechanics of bringing these fluids together from above and below remain unclear. Classical percolative Darcy-flow models are inconsistent with (1) fluid overpressure indicated by fracturing and brecciation, (2) fast fluid flow indicated by thermal disequilibrium, and (3) strong fluid composition variations on the mm-scale, indicated by fluid inclusion analyses (Bons et al. 2012; Fusswinkel et al. 2013). We propose that fluids first descend, sucked down by desiccation reactions in exhumed basement. Oldest fluids reach greatest depths, where long residence times and elevated temperatures allow them the extensively equilibrate with their host rock, reach high salinity and scavenge metals, if present. Youngest fluids can only penetrate to shallower depths and can (partially) retain signatures from their origin, for example high Cl/Br ratios from the dissolution of evaporitic halite horizons. When fluids are released from all levels of the crustal column, these fluids mix during rapid ascent to form hydrothermal ore deposits. Mixing from below provides a viable hydromechanical mechanism to explain the common phenomenon of mixed shallow and deep fluids in hydrothermal ore deposits. Bons, P.D., Elburg, M.A., Gomez-Rivas, E. 2012. A review of the formation of tectonic veins and their microstructures. J. Struct. Geol. doi:10.1016/j.jsg.2012.07.005 Fusswinkel, T., Wagner, T., Wälle, M., Wenzel, T., Heinrich, C.A., Markl, M. 2013. Fluid mixing forms basement-hosted Pb-Zn deposits: Insight from metal and halogen geochemistry of individual fluid inclusions. Geology. doi:10.1130/G34092.1

  6. Niobium sputter deposition on quarter wave resonators

    CERN Document Server

    Viswanadham, C; Jayaprakash, D; Mishra, R L

    2003-01-01

    Niobium sputter deposition on quarter wave copper R.F resonators, have been taken up in our laboratory, An ultra high vacuum system was made for this purpose. Niobium exhibits superconducting properties at liquid Helium temperature. A uniform coating of about 1.5 mu m of niobium on the internal surfaces of the copper resonant cavities is desired. Power dissipation in the resonators can be greatly reduced by making the internal surfaces of the R.F cavity super conducting. (author)

  7. Determination of electroless deposition by chemical nickeling

    OpenAIRE

    Badida, M.; M. Gombár; L. Sobotová; J. Kmec

    2013-01-01

    Increasing of technical level and reliability of machine products in compliance with the economical and ecological terms belongs to the main trends of the industrial development. During the utilisation of these products there arise their each other contacts and the interaction with the environment. That is the reason for their surface degradation by wear effect, corrosion and other influences. The chemical nickel-plating allows autocatalytic deposition of nickel from water solutions in the fo...

  8. Australia's experience with the variable deposit requirement

    OpenAIRE

    Australian Treasury

    1999-01-01

    This article examines the implementation of the Variable Deposit Requirement (VDR) capital control scheme in Australia in the 1970s. It notes that while capital controls can play a role in certain circumstances, they should not be used as a substitute for addressing underlying policy needs or financial sector reforms of an economy. The scheme was short-term in nature, and depended on subjective judgements about what level of capital inflow was appropriate at the time, and was unrelated to lon...

  9. Controlled Deposition and Alignment of Carbon Nanotubes

    Science.gov (United States)

    Smits, Jan M. (Inventor); Wincheski, Russell A. (Inventor); Patry, JoAnne L. (Inventor); Watkins, Anthony Neal (Inventor); Jordan, Jeffrey D. (Inventor)

    2012-01-01

    A carbon nanotube (CNT) attraction material is deposited on a substrate in the gap region between two electrodes on the substrate. An electric potential is applied to the two electrodes. The CNT attraction material is wetted with a solution defined by a carrier liquid having carbon nanotubes (CNTs) suspended therein. A portion of the CNTs align with the electric field and adhere to the CNT attraction material. The carrier liquid and any CNTs not adhered to the CNT attraction material are then removed.

  10. Trail formation based on directed pheromone deposition

    OpenAIRE

    Boissard, Emmanuel; Degond, Pierre; Motsch, Sébastien

    2011-01-01

    We propose an Individual-Based Model of ant-trail formation. The ants are modeled as self-propelled particles which deposit directed pheromones and interact with them through alignment interaction. The directed pheromones intend to model pieces of trails, while the alignment interaction translates the tendency for an ant to follow a trail when it meets it. Thanks to adequate quantitative descriptors of the trail patterns, the existence of a phase transition as the ant-pheromone interaction fr...

  11. Quality study of a fedspar deposit

    OpenAIRE

    Taboada, J.; Vaamonde, A.; Saavedra, A.; Argüelles, A.

    2000-01-01

    This work describes a pegmatite mineral deposit composed by some veins of a length between 50 and 800 meters and a width of almost 15 meters. With the purpose to evaluate the potential exploitation, we have characterized the quality of the selling product, through a sampling procedure, granulometric classification, magnetic separation, flotation process and mineralogical analysis. In order to establish the more able flotation process, we have tested different methods, that we also include her...

  12. Deposition and Coating Properties on CVD Tungsten

    Institute of Scientific and Technical Information of China (English)

    DU Ji-hong; LI Zheng-xiang; LIU Gao-jian; ZHOU Hui-Huang; CHUN liang

    2004-01-01

    Surface characterization and microstructure studies are performed on chemical vapor deposited (CVD) tungsten coating. There is about 2 μm thickness diffusion layer of tungsten in the molybdenum substrate. The thermal shock test shows tungsten coating has good adhesion with molybdenum substrate, but the elements of oxygen and carbon in the tungsten coating have the bad affection to the adhesion. The result of high-temperature diffusion experiment is the diffusion rate from molybdenum substrate to tungsten coating is faster.

  13. Electrostatic force assisted deposition of graphene

    Science.gov (United States)

    Liang, Xiaogan

    2011-11-15

    An embodiment of a method of depositing graphene includes bringing a stamp into contact with a substrate over a contact area. The stamp has at least a few layers of the graphene covering the contact area. An electric field is developed over the contact area. The stamp is removed from the vicinity of the substrate which leaves at least a layer of the graphene substantially covering the contact area.

  14. Complex Materials by Atomic Layer Deposition.

    Science.gov (United States)

    Schwartzberg, Adam M; Olynick, Deirdre

    2015-10-14

    Complex materials are defined as nanostructured materials with combinations of structure and/or composition that lead to performance surpassing the sum of their individual components. There are many methods that can create complex materials; however, atomic layer deposition (ALD) is uniquely suited to control composition and structural parameters at the atomic level. The use of ALD for creating complex insulators, semiconductors, and conductors is discussed, along with its use in novel structural applications.

  15. Particle size-density relationships in pyroclastic deposits: using component subpopulations to elucidate depositional conditions

    Science.gov (United States)

    Mackaman-Lofland, C. A.; Brand, B. D.; Taddeucci, J.

    2012-12-01

    Pyroclastic Density Currents (PDCs) are ground-hugging currents of hot gas, ash, and rock that travel at velocities up to 150 m/s down the flanks of volcanoes. PDCs are the most dangerous hazard associated with explosive volcanic eruptions, but because of current opacity and the risk inherent to observing PDCs in real time, their processes are poorly understood. Geologists rely on depositional relationships to lend insight into PDC transport and depositional processes. Outcrop exposure is typically incomplete, however, and the extent to which outcrop-scale depositional characteristics are representative of the parent current is still uncertain. The May 18th, 1980 eruption of Mt. St. Helens (MSH) produced multiple PDCs, burying the area north of the crater under 10s of meters of PDC deposits. Deep drainage erosion over the past 30 years has exposed these deposits in three dimensions, allowing a detailed study of deposit structures to be conducted for a variety of locations and depositional regimes with distance from source. We examine the grain size distribution and density characteristics of the discrete component subpopulations that make up the solids fraction of PDC deposits, focusing on changes associated with lateral facies variation, distance from source, and degree of topographic roughness. We analyze the grain size and density relationships of the component subpopulations using sequential fragmentation / transport theory (SFT), and use crystal morphoscopy to determine how different regional transport systems effect feldspar and hornblende crystal shape following the methods of Taddeucci and Palladino ((2002) Particle size-density relationships in pyroclastic deposits: inferences for emplacement processes. Bull Volcanol 64:273-284). Calculations of representative proximal and distal samples indicate juvenile pumice densities of ~1.3g/mL, accidental lithic densities of ~2.7g/mL, and crystal densities of ~2.6g/mL. We observe a general decrease in grain size and

  16. GYPSUM DEPOSITS IN THE REPUBLIC OF CROATIA

    Directory of Open Access Journals (Sweden)

    Anto Gabrić

    2002-12-01

    Full Text Available The occurences and deposits of gypsum can be found in big karst poljes (Sinjsko, Vrličko, Petrovo, Kosovo and Kninsko as well as in tectonnically predestined river valleys of Zrmanja, Butišnica and Una. There also appear spatially localized occurences on the island of Vis and in the vicinity of Samobor. Evaporites (gypsum and anhydrite with adjoining overlying clastic rocks (red sandstones, siltites and pelites, carbonate rocks (dolomites and limestones and porous carbonate breccias (Rauhwackes were deposited during the period of Upper Permian. The recent position of the Upper Permian beds is a result of complex tectonic, particularly neotectonic, movements and diapiric displacements. Evaporites were deposited in marginal areas of the epicontinental marine basin, in a period of favourable conditions for the sabkha and playa sedimentation due to the continuous shoreline progradation. The Upper Permian age of these sediments in Dalmatio is proved by the characteristic mineral paragenesis and palinological determinations in elastics rocks, as well as by isotope analyses of sulphure in gypsum. Gypsum is a significant ore mineral resource in building, cement production, as well as in a number of tehnological processes used in chemical industry and elsewhere. According to the recent investigations gypsum is predestined to serve as an ore mineral resource of significant perspectives (the paper is published in Croatian.

  17. Pulsed laser deposition of rare earth compounds

    CERN Document Server

    Stone, L A

    2001-01-01

    Magnetostrictive thin films have been deposited using various techniques such as sputtering and evaporation but the use of laser deposition has been limited. This research presents the results from pulsed laser deposition (PLD) of TbFe sub 2 , DyFe sub 2 and Terfenol-D thin films using an infra red Transversely Excited Atmospheric (TEA) CO sub 2 laser at lambda approx 10.6 mu m and an ultra violet Argon-Fluoride (ArF) excimer laser at lambda approx 193 nm. Results have showed that the TEA CO sub 2 laser under the range of conditions studied is not suitable for the production of magnetostrictive films. The problems experienced are a mixture of mostly fracture debris at low fluences (F approx 20 Jcm sup - sup 2) and melt droplets at high fluences (F approx 60 Jcm sup - sup 2). In all cases the destruction of the target is a major problem, with the Terfenol-D targets being the worst affected. Thin films produced were all iron rich. The use of an excimer laser has proved more successful in providing stoichiometri...

  18. Deposited sediment settlement and consolidation mechanisms

    Directory of Open Access Journals (Sweden)

    Shuai-jie Guo

    2015-10-01

    Full Text Available In order to study deposited sediment settlement and consolidation mechanisms, sediment settlement experiments were conducted using a settlement column. Based on the experimental results, sediment settlement stage definition, excessive pore pressure (EPP dissipation, and consolidation constitutive equations are discussed. Three stages, including the free settlement, hindered settlement, and self-weight consolidation settlement stages, are defined. The results of this study show that sediment settlement is mainly affected by the initial sediment concentration and initial settlement height, and the interface settlement rate is attenuated linearly with time on bilogarithmic scales during the hindered settlement and self-weight consolidation settlement stages. Moreover, the deposited sediment layer in the self-weight consolidation settlement stage experiences large strains, and the settlement amount in this stage is about 32% to 59% of the initial height of deposited sediment. EPP is nonlinearly distributed in the settlement direction, and consolidation settlement is faster than EPP dissipation in the self-weight consolidation settlement stage. Consolidation constitutive equations for the hydraulic conductivity and effective stress, applicable to large-strain consolidation calculation, were also determined and fitted in the power function form.

  19. Alkylphenols in atmospheric depositions and urban runoff.

    Science.gov (United States)

    Bressy, A; Gromaire, M-C; Lorgeoux, C; Chebbo, G

    2011-01-01

    A sampling campaign was conducted in order to determine alkylphenol (AP) concentrations in stormwater as well as potential AP sources in suburban environments. An analytical procedure was developed to quantify APs in bulk atmospheric deposition, building runoff, road runoff and stormwater. Both nonylphenols and octylphenols could be quantified in each sample. Median stormwater concentrations amounted to: 470 ng/l for nonylphenols, and 36 ng/l for octylphenols. These concentrations are 3 times higher than those found in atmospheric deposition, thus proving that local human activity constitutes a significant source of contamination. The contributions of the various sources to stormwater have been assessed from mass balances at the catchment scale. 70% of AP mass in stormwater originates from building and road emissions. Annual AP fluxes have been extrapolated from the total AP mass measured over our sampling periods for atmospheric depositions (44 to 84 µgNP/m(2)/yr) and stormwater (100 to 190 µgNP/m(2)/yr). Moreover, since APs were mainly found in the dissolved fraction, runoff treatment devices based on settling are unlikely to be very efficient. PMID:21330713

  20. Na Deposition on MnO(100)

    Science.gov (United States)

    Feng, Xu; Cox, David F.

    2016-03-01

    Na deposition on the MnO(100) surface was investigated by temperature programmed desorption (TPD), X-ray photoelectron spectroscopy (XPS) and low energy electron diffraction (LEED). Na TPD and XPS results indicate that adsorbed Na interacts strongly with the MnO substrate to form an irreversibly-adsorbed, oxidic Na compound on the surface for coverages up to 1 monolayer (ML). This strongly-bound Na diffuses into the MnO subsurface and bulk at elevated temperatures above 500 K. For Na coverages above 1 ML, metallic Na is present and desorbs from the surface below 500 K. The deposition of Na on MnO(100) follows a Stranski-Krastanov (SK) growth mode, with the formation of metallic Na islands following completion of the first Na monolayer. After Na deposition, the surface exhibits a diffuse (1 × 1) LEED pattern, suggesting the formation of disordered Na overlayers. After heating to 1000 K, the surface presents a (2 × 2) LEED pattern indicating that a surface reconstruction is induced by the diffusion of Na into the near surface region. CO2 can be used as a probe molecule in TPD to distinguish between metallic Na islands and oxidic Na in the first ML, and to indicate when Na that is still observable by XPS goes subsurface.

  1. High-deposition-rate ceramics synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Allendorf, M.D.; Osterheld, T.H.; Outka, D.A. [Sandia National Laboratories, Livermore, CA (United States)] [and others

    1995-05-01

    Parallel experimental and computational investigations are conducted in this project to develop validated numerical models of ceramic synthesis processes. Experiments are conducted in the High-Temperature Materials Synthesis Laboratory in Sandia`s Combustion Research Facility. A high-temperature flow reactor that can accommodate small preforms (1-3 cm diameter) generates conditions under which deposition can be observed, with flexibility to vary both deposition temperature (up to 1500 K) and pressure (as low as 10 torr). Both mass spectrometric and laser diagnostic probes are available to provide measurements of gas-phase compositions. Experiments using surface analytical techniques are also applied to characterize important processes occuring on the deposit surface. Computational tools developed through extensive research in the combustion field are employed to simulate the chemically reacting flows present in typical industrial reactors. These include the CHEMKIN and Surface-CHEMKIN suites of codes, which permit facile development of complex reaction mechanisms and vastly simplify the implementation of multi-component transport and thermodynamics. Quantum chemistry codes are also used to estimate thermodynamic and kinetic data for species and reactions for which this information is unavailable.

  2. Characterization of radioactive deposits in primary circuits

    International Nuclear Information System (INIS)

    Reduction of the dose rate that results from crud deposits in various systems of nuclear power plants, seems to be one of the most efficient steps to reduce collective operations doses recived by personnel working in these plants. At present, various processes are being applied tending to minimize those phonemena that lead to the generation of these radiation fields. For this reason, a great emphasis is attached to providing a procedure to follow-up the evolution of contamination levels produced in each system, and to asses the effects achieved by aplying corrective measures. At the Santa Maria de Garona nuclear plant, a device has been designed together with a procedure, to allow for gamma spectrometry tests to be performed on lines and other components as well as to quantify the specific activity of each of the isotopes presents in crud deposits. This method has been applied to measure the isotopes deposited in the Reactor Recirculation System lines, resulting that 76,8% of the total dose rate is due to Co''60 and 83.6% comes from both C0''60 and C0''58 put together. Smaller shares are attributable to Mn''54(10,6%), Fe(2,9%), Zn''65(1,4%) and Sb''124(1,4%)

  3. Supersonic Flow Control Using Combined Energy Deposition

    Directory of Open Access Journals (Sweden)

    O. A. Azarova

    2015-03-01

    Full Text Available Drag force control via energy deposition in an oncoming flow is a wide area of interest in aerospace sciences. Recently, investigations on the effect of combining energy sources have been conducted. The possibility of coupling microwave (MW discharges or MW and laser energy deposition is discussed. In the present work, the flow details accompanying the interaction of a combined energy release and an aerodynamic body in a supersonic flow are considered numerically on the base of the Euler equations. Comparison with non-combined energy deposition is analyzed. The effect of introducing the internal part to the energy release on the drag force reduction is examined. The flows for blunt cylinder, hemisphere-cylinder and pointed body are considered for a wide class of the combined energy source characteristics. Freestream Mach number is varied from 1.89 to 3.45. Complicated unsteady vortex structures caused by the Richtmyer–Meshkov instabilities are shown to be the reason for the reduction in drag. The unsteady double vortex mechanism of the frontal drag force reduction and mechanism of the constantly acting vortices at the steady flow are described. Suppression of shear layer instability and large scaled flow pulsations as the result of the combined energy release effect is established. Complex conservative difference schemes are used in the simulations.

  4. Source Molecular Effect on Amorphous Carbon Film Deposition

    OpenAIRE

    Kawazoe, Hiroki; Inayoshi, Takanori; Shinohara, Masanori; Matsuda, Yoshinobu; Fujiyama, Hiroshi; Nitta, Yuki; Nakatani, Tatsuyuki

    2009-01-01

    We investigated deposition process of amorphous carbon films using acetylene and methane as a source molecule, by using infrared spectroscopy in multiple internal reflection geometry (MIR-IRAS). We found that deposited film structures were different due to source molecules.

  5. Mineral deposits research in Uruguay. Technical economic part

    International Nuclear Information System (INIS)

    Technical researches, mineralogical and chemical analysis were carried out in Zapucay and Iman deposit located in Uruguay south America, as a result of that, researchers was described the mineral adherences of the deposits.

  6. Ash Deposition Trials at Three Power Stations in Denmark

    DEFF Research Database (Denmark)

    Laursen, Karin; Frandsen, Flemming; Larsen, Ole Hede

    1998-01-01

    Six full-scale trials were conducted at three power stations in Denmark: Ensted, Funen, and Vendsyssel power stations. During these trials, pulverized coal, bottom ash, fly ash, and deposits from cooled probes were sampled and analyzed with various techniques. On the basis of SEM analyses......, the deposits can be grouped into five textural types, which all possess distinct textural and chemical characteristics. Likewise, the deposition mechanisms for these five types are characteristic and they may be used for constructing a model for the buildup and maturation of an ash deposit. The deposits...... collected on the probes were thin (maximum 2 mm after 9 h) and the influence of operational parameters and probe temperatures on the magnitude of the deposits were minor. The probe temperatures had no influence on the composition of the ash deposits for coals with low ash deposition propensities, whereas...

  7. Multiwalled Carbon Nanotube Deposition on Model Environmental Surfaces

    Science.gov (United States)

    Deposition of multiwalled carbon nanotubes (MWNTs) on model environmental surfaces was investigated using a quartz crystal microbalance with dissipation monitoring (QCM-D). Deposition behaviors of MWNTs on positively and negatively charged surfaces were in good agreement with Der...

  8. Point locations and characteristics of evaporite-related potash deposits

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This spatial database of evaporite-related potash deposits and occurrences provides location and descriptive information for 981 deposits and occurrences that are...

  9. Influence of deposit architecture on intrastratal deformation, slope deposits of the Tres Pasos Formation, Chile

    Science.gov (United States)

    Auchter, Neal C.; Romans, Brian W.; Hubbard, Stephen M.

    2016-07-01

    Slope sediments on passive and active margins deform and fail across a broad range of scales ranging from loading and sediment remobilization near the sediment-water interface to submarine landslides and mass movements that incorporate significant volumes of slope deposits. Deformational styles are characterized by updip extension and downdip compressional features that occur above a detachment surface. Conditions for failure and deformation include the presence of weak layer(s) that serve as a detachment surface, competency contrasts that allow for detachment and downslope movement, deformation above a detachment surface, and a triggering mechanism(s) that initiates failure. Slope failure processes and products are well documented at scales resolvable by seismic-reflection surveys and in instances of extensive downslope failure, but the processes and products associated with intermediate-scale slope deformation are poorly understood. Intrastratal deformation is defined as stratigraphically isolated zones of deformation bounded above and below by concordant and undeformed strata. In this study, outcrop examples of intrastratal deformation from the Upper Cretaceous Tres Pasos Formation are used to elucidate the influence of depositional architecture on slope deformation. The facies distribution associated with compensational stacking of lobe deposits is shown to have a first-order control on the location and style of deformation. Detachment planes that form in mudstone deposits associated with lobe fringe and interlobe deposits are spatially limited and deformation is restricted to interbedded sandstone and mudstone associated with off-axial lobe positions. Downslope translation was arrested by stratigraphic buttresses associated with more sandstone-prone axial deposits. Emplacement of a regionally extensive mass transport deposit is interpreted as the triggering mechanism for contemporaneous intrastratal deformation of > 60 m of underlying stratigraphy. A vertical

  10. In Situ Electrochemical Deposition of Microscopic Wires

    Science.gov (United States)

    Yun, Minhee; Myung, Nosang; Vasquez, Richard

    2005-01-01

    A method of fabrication of wires having micron and submicron dimensions is built around electrochemical deposition of the wires in their final positions between electrodes in integrated circuits or other devices in which the wires are to be used. Heretofore, nanowires have been fabricated by a variety of techniques characterized by low degrees of controllability and low throughput rates, and it has been necessary to align and electrically connect the wires in their final positions by use of sophisticated equipment in expensive and tedious post-growth assembly processes. The present method is more economical, offers higher yields, enables control of wire widths, and eliminates the need for post-growth assembly. The wires fabricated by this method could be used as simple electrical conductors or as transducers in sensors. Depending upon electrodeposition conditions and the compositions of the electroplating solutions in specific applications, the wires could be made of metals, alloys, metal oxides, semiconductors, or electrically conductive polymers. In this method, one uses fabrication processes that are standard in the semiconductor industry. These include cleaning, dry etching, low-pressure chemical vapor deposition, lithography, dielectric deposition, electron-beam lithography, and metallization processes as well as the electrochemical deposition process used to form the wires. In a typical case of fabrication of a circuit that includes electrodes between which microscopic wires are to be formed on a silicon substrate, the fabrication processes follow a standard sequence until just before the fabrication of the microscopic wires. Then, by use of a thermal SiO-deposition technique, the electrodes and the substrate surface areas in the gaps between them are covered with SiO. Next, the SiO is electron-beam patterned, then reactive-ion etched to form channels having specified widths (typically about 1 m or less) that define the widths of the wires to be formed. Drops

  11. Imbalanced phosphorus and nitrogen deposition in China's forests

    Science.gov (United States)

    Du, Enzai; de Vries, Wim; Han, Wenxuan; Liu, Xuejun; Yan, Zhengbing; Jiang, Yuan

    2016-07-01

    Acceleration of anthropogenic emissions in China has substantially increased nitrogen (N) deposition during the last 3 decades and may result in an imbalance of atmospheric N and phosphorus (P) inputs in terrestrial ecosystems. However, the status of P deposition in China is poorly understood. This study synthesized data on total P and total N concentrations in bulk precipitation and throughfall from published literature to assess the characteristics of P deposition, N deposition and N : P deposition ratio in China's forests. Our results show relatively high mean rates of bulk P deposition (0.38 kg P ha-1 yr-1) and total P deposition (0.69 kg P ha-1 yr-1), but they were accompanied by even more elevated N inputs via bulk deposition (16.5 kg N ha-1 yr-1) and total deposition (21.6 kg N ha-1 yr-1), resulting in high N : P ratios in bulk deposition (44.4) and total deposition (32.8). Based on the difference between total deposition and bulk deposition, canopy-captured dry P and N deposition was estimated to be 0.31 kg P ha-1 yr-1 and 5.1 kg N ha-1 yr-1, respectively. We found significantly higher P deposition and lower N : P ratios at sites nearby than those far from semiarid regions. The estimated bulk and total deposition of P and N both showed a significant power-law increase with decreasing distance to the nearest large cities either in the areas nearby or far from semiarid regions. Our results suggest an anthropogenic alternation of regional P and N cycling, which may shift large areas of China's forests towards human-induced P limitation especially in southern China.

  12. Deposition of Aluminium Oxide Films by Pulsed Reactive Sputtering

    Institute of Scientific and Technical Information of China (English)

    Xinhui MAO; Bingchu CAI; Maosong WU; Guoping CHEN

    2003-01-01

    Pulsed reactive sputtering is a novel process used to deposit some compound films, which are not deposited by traditional D.C. reactive sputtering easily. In this paper some experimental results about the deposition of Al oxide films by pulsed reactive sputtering are presented. The hysteresis phenomenon of the sputtering voltage and deposition rate with the change of oxygen flow during sputtering process are discussed.

  13. Imparting passivity to vapor deposited magnesium alloys

    Science.gov (United States)

    Wolfe, Ryan C.

    Magnesium has the lowest density of all structural metals. Utilization of low density materials is advantageous from a design standpoint, because lower weight translates into improved performance of engineered products (i.e., notebook computers are more portable, vehicles achieve better gas mileage, and aircraft can carry more payload). Despite their low density and high strength to weight ratio, however, the widespread implementation of magnesium alloys is currently hindered by their relatively poor corrosion resistance. The objective of this research dissertation is to develop a scientific basis for the creation of a corrosion resistant magnesium alloy. The corrosion resistance of magnesium alloys is affected by several interrelated factors. Among these are alloying, microstructure, impurities, galvanic corrosion effects, and service conditions, among others. Alloying and modification of the microstructure are primary approaches to controlling corrosion. Furthermore, nonequilibrium alloying of magnesium via physical vapor deposition allows for the formation of single-phase magnesium alloys with supersaturated concentrations of passivity-enhancing elements. The microstructure and surface morphology is also modifiable during physical vapor deposition through the variation of evaporation power, pressure, temperature, ion bombardment, and the source-to-substrate distance. Aluminum, titanium, yttrium, and zirconium were initially chosen as candidates likely to impart passivity on vapor deposited magnesium alloys. Prior to this research, alloys of this type have never before been produced, much less studied. All of these metals were observed to afford some degree of corrosion resistance to magnesium. Due to the especially promising results from nonequilibrium alloying of magnesium with yttrium and titanium, the ternary magnesium-yttrium-titanium system was investigated in depth. While all of the alloys are lustrous, surface morphology is observed under the scanning

  14. Simulated dry deposition of nitric acid near forest edges

    NARCIS (Netherlands)

    DeJong, JJM; Klaassen, W; Jong, J.J.M. de

    1997-01-01

    Dry deposition is simulated to understand and generalize observations of enhanced deposition of air pollution near forest edges. Nitric acid is taken as an example as its deposition velocity is often assumed to be determined by turbulent transport only. The simulations are based on the micro-meteoro

  15. Acid deposition and its implications for nature conservation in Britain

    Energy Technology Data Exchange (ETDEWEB)

    Fry, G.L.A.; Cooke, A.S.

    1984-01-01

    A general consideration of acid deposition is given, in terms of the origins and fate of acid deposition and its effects on terrestrial, freshwater and marine ecosystems. Acid deposition in wetland sites in Britain is discussed, and conclusions are drawn for nature conservation in Britain. (177 refs.)

  16. Human respiratory deposition of particles during oronasal breathing

    Science.gov (United States)

    Swift, David L.; Proctor, Donald F.

    Deposition of particles in the tracheobronchial and pulmonary airways is computed as a function of particle size, correcting for deposition in the parallel nasal and oral airways with oronasal breathing. Thoracic deposition is lower at all sizes for oronasal breathing than for mouth breathing via tube, and is negligible for aerodynamic equivalent diameters of 10 μm or larger.

  17. Grade-Tonnage Model of Porphyry Copper Deposits of China

    Institute of Scientific and Technical Information of China (English)

    Wang Xueping; Wei Min; Yang Lipei; Zhao Jingman

    2003-01-01

    A grade-tonnage model is established according to the analysis of 72 porphyry copper deposits recorded in "The Mineral Resources Data Base of China". Based on the analysis of frequency histogram, the cumulative frequency distributing graph and the theoretical model with double logarithmic coordinates of copper deposits, the typical mathematical characteristics of grade-tonnage model of porphyry copper deposits are clarified.

  18. Particle deposition in low-speed, high-turbulence flows

    DEFF Research Database (Denmark)

    Reck, Mads; Larsen, Poul Scheel; Ullum, U.

    2002-01-01

    field measurements. Particle deposition is shown to be associated with near-wall coherent structures. Flow reversal, simulated by impulsive start, is shown to give higher deposition rates than steady mean flows. Key word index: Spoilage fungi; spores; food processing plant; deposition flux; large eddy...

  19. Resonant infrared pulsed laser deposition of thin biodegradable polymer films

    DEFF Research Database (Denmark)

    Bubb, D.M.; Toftmann, B.; Haglund Jr., R.F.;

    2002-01-01

    Thin films of the biodegradable polymer poly(DL-lactide-co-glycolide) (PLGA) were deposited using resonant infrared pulsed laser deposition (RIR-PLD). The output of a free-electron laser was focused onto a solid target of the polymer, and the films were deposited using 2.90 (resonant with O...

  20. 24 CFR 291.535 - Earnest money deposit.

    Science.gov (United States)

    2010-04-01

    ... 24 Housing and Urban Development 2 2010-04-01 2010-04-01 false Earnest money deposit. 291.535... Next Door Sales Program § 291.535 Earnest money deposit. (a) General. The earnest money deposit is the sum of money that must be paid by the law enforcement officer, teacher, or...

  1. Nickel-cobalt laterites: a deposit model: Chapter H in Mineral deposit models for resource assessment

    Science.gov (United States)

    Marsh, Erin; Anderson, Eric J.; Gray, Floyd

    2013-01-01

    Nickel-cobalt (Ni-Co) laterite deposits are supergene enrichments of Ni±Co that form from intense chemical and mechanical weathering of ultramafic parent rocks. These regolith deposits typically form within 26 degrees of the equator, although there are a few exceptions. They form in active continental margins and stable cratonic settings. It takes as little as one million years for a laterite profile to develop. Three subtypes of Ni-Co laterite deposits are classified according to the dominant Ni-bearing mineralogy, which include hydrous magnesium (Mg)-silicate, smectite, and oxide. These minerals form in weathering horizons that begin with the unweathered protolith at the base, saprolite next, a smectite transition zone only in profiles where drainage is very poor, followed by limonite, and then capped with ferricrete at the top. The saprolite contains Ni-rich hydrous Mg-silicates, the Ni-rich clays occur in the transition horizon, and Ni-rich goethite occurs in the limonite. Although these subtypes of deposits are the more widely used terms for classification of Ni-Co laterite deposits, most deposits have economic concentrations of Ni in more than one horizon. Because of their complex mineralogy and heterogeneous concentrations, mining of these metallurgically complex deposits can be challenging. Deposits range in size from 2.5 to about 400 million tonnes, with Ni and Co grades of 0.66–2.4 percent (median 1.3) and 0.01–0.15 percent (median 0.08), respectively. Modern techniques of ore delineation and mineralogical identification are being developed to aid in streamlining the Ni-Co laterite mining process, and low-temperature and low-pressure ore processing techniques are being tested that will treat the entire weathered profile. There is evidence that the production of Ni and Co from laterites is more energy intensive than that of sulfide ores, reflecting the environmental impact of producing a Ni-Co laterite deposit. Tailings may include high levels of

  2. Prediction of wall deposition behaviour in a pilot-scale spray dryer using deposition correlations for pipe flows

    Institute of Scientific and Technical Information of China (English)

    KOTA K.; LANGRISH T.A.G.

    2007-01-01

    The particle deposition behaviour of skim milk, water and maltodextrin in the conical section of a pilot-scale spray dryer was predicted using simple correlations for particle depositions in pipes. The predicted particle deposition fluxes of these materials were then compared with the measured deposition fluxes. The predicted particle deposition regimes of the spray dryer were expected to be in the diffusional and mixed (diffusional and inertial) regimes, but the experimental results suggested that the particle deposition was mainly in the inertial regime. Therefore, using the pipe correlations for predicting deposition in a pilot-scale spray dryer suggests that they do not sufficiently represent the actual deposition behaviour. This outcome indicates that a further study of particle flow patterns needs to be carried out using numerical simulations (computational fluid dynamics,CFD) in view of the additional geometrical complexity of the spray dryer.

  3. In-situ CdS/CdTe Heterojuntions Deposited by Pulsed Laser Deposition

    KAUST Repository

    Avila-Avendano, Jesus

    2016-04-09

    In this paper pulsed laser deposition (PLD) methods are used to study p-n CdTe/CdS heterojunctions fabricated in-situ. In-situ film deposition allows higher quality p-n interfaces by minimizing spurious contamination from the atmosphere. Morphologic and structural analyses were carried for CdTe films deposited on various substrates and different deposition conditions. The electrical characteristics and performance of the resulting p-n heterojunctions were studied as function of substrate and post-deposition anneal temperature. In-situ growth results on diodes with a rectification factor of ~ 105, an ideality factor < 2, and a reverse saturation current ~ 10-8 A. The carrier concentration in the CdTe film was in the range of ~ 1015 cm-3, as measured by C-V methods. The possible impact of sulfur diffusion from the CdS into the CdTe film is also investigated using High Resolution Rutherford Back-Scattering.

  4. Experimental study of porosity reduction in high deposition-rate Laser Material Deposition

    Science.gov (United States)

    Zhong, Chongliang; Gasser, Andres; Schopphoven, Thomas; Poprawe, Reinhart

    2015-12-01

    For several years, the interest in Additive Manufacturing (AM) is continuously expanding, owing to the paradigm shift that new production processes, such as Laser Material Deposition (LMD), provide over conventional manufacturing technologies. With LMD, three-dimensional, complex components out of a wide range of materials can be manufactured consecutively layer-by-layer. Despite the technological advantages of the LMD process, currently achieved deposition-rates of approx. 0.5 kg/h for Inconel 718 (IN 718) remain a major concern in regards to processing times and economic feasibility. Moreover, processing conditions need to be chosen carefully or else material defects can be systematically formed either at the interface separating two adjacent clad layers, at the bonding zone or within the bulk of the layer. In this respect, the effects of powder humidity, laser power, nominal powder particle size, powder morphology and shielding gas flow rate on the porosity in laser deposited single tracks at an increased deposition-rate of approx. 2 kg/h was investigated through experiments. Based on experimental results, several approaches of reducing porosity in high deposition-rate LMD are proposed in this paper.

  5. A new pulsed laser deposition technique: scanning multi-component pulsed laser deposition method.

    Science.gov (United States)

    Fischer, D; de la Fuente, G F; Jansen, M

    2012-04-01

    The scanning multi-component pulsed laser deposition (PLD) method realizes uniform depositions of desired coatings by a modified pulsed laser deposition process, preferably with a femto-second laser-system. Multi-component coatings (single or multilayered) are thus deposited onto substrates via laser induced ablation of segmented targets. This is achieved via horizontal line-scanning of a focused laser beam over a uniformly moving target's surface. This process allows to deposit the desired composition of the coating simultaneously, starting from the different segments of the target and adjusting the scan line as a function of target geometry. The sequence and thickness of multilayers can easily be adjusted by target architecture and motion, enabling inter/intra layer concentration gradients and thus functional gradient coatings. This new, simple PLD method enables the achievement of uniform, large-area coatings. Case studies were performed with segmented targets containing aluminum, titanium, and niobium. Under the laser irradiation conditions applied, all three metals were uniformly ablated. The elemental composition within the rough coatings obtained was fixed by the scanned area to Ti-Al-Nb = 1:1:1. Crystalline aluminum, titanium, and niobium were found to coexist side by side at room temperature within the substrate, without alloy formation up to 600 °C. PMID:22559543

  6. Characterisation of TiO 2 deposited by photo-induced chemical vapour deposition

    Science.gov (United States)

    Kaliwoh, Never; Zhang, Jun-Ying; Boyd, Ian W.

    2002-01-01

    We report the deposition of thin TiO 2 films on crystalline Si and quartz by photo-induced chemical vapour deposition (CVD) using UV excimer lamps employing a dielectric barrier discharge in krypton chloride (KrCl ∗) to provide intense narrow band radiation at λ=222 nm. The precursor used was titanium isopropoxide (TTIP). Films from around 20-510 nm in thickness with refractive indices from 2.20 to 2.54 were grown at temperatures between 50 and 350 °C. The higher refractive index values compare favourably with the value of 2.58 recorded for the bulk material. The measured deposition rate was around 50 nm/min at 350 °C. Fourier transform infrared spectroscopy (FTIR) revealed the presence of TiO 2 through the observation of a Ti-O absorption peak and the absence of OH in films deposited at 250-350 °C indicated relatively good quality films. The phase of films deposited at 200-350 °C was anatase as determined by X-ray diffraction.

  7. Effects of Ar plasma treatment for deposition of ruthenium film by remote plasma atomic layer deposition

    International Nuclear Information System (INIS)

    Ruthenium thin films were deposited on argon plasma-treated SiO2 and untreated SiO2 substrates by remote plasma atomic layer deposition using bis(ethylcyclopentadienyl)ruthenium [Ru(EtCp)2] as a Ru precursor and ammonia plasma as a reactant. The results of in situ Auger electron spectroscopy (AES) analysis indicate that the initial transient region of Ru deposition was decreased by Ar plasma treatment at 400 deg. C, but did not change significantly at 300 deg. C The deposition rate exhibited linearity after continuous film formation and the deposition rates were about 1.7 A/cycle and 0.4 A/cycle at 400 deg. C and 300 deg. C, respectively. Changes of surface energy and polar and dispersive components were measured by the sessile drop test. The quantity of surface amine groups was measured from the surface nitrogen concentration with AES. Furthermore, the Ar plasma-treated SiO2 contained more amine groups and less hydroxyl groups on the surface than on untreated SiO2. Auger spectra exhibited chemical shifts by Ru-O bonding, and larger shifts were observed on untreated substrates due to the strong adhesion of Ru films.

  8. Selective deposition contact patterning using atomic layer deposition for the fabrication of crystalline silicon solar cells

    International Nuclear Information System (INIS)

    Selective deposition contact (SDC) patterning was applied to fabricate the rear side passivation of crystalline silicon (Si) solar cells. By this method, using screen printing for contact patterning and atomic layer deposition for the passivation of Si solar cells with Al2O3, we produced local contacts without photolithography or any laser-based processes. Passivated emitter and rear-contact solar cells passivated with ozone-based Al2O3 showed, for the SDC process, an up-to-0.7% absolute conversion-efficiency improvement. The results of this experiment indicate that the proposed method is feasible for conversion-efficiency improvement of industrial crystalline Si solar cells. - Highlights: • We propose a local contact formation process. • Local contact forms a screen print and an atomic layer deposited-Al2O3 film. • Ozone-based Al2O3 thin film was selectively deposited onto patterned silicon. • Selective deposition contact patterning method can increase cell-efficiency by 0.7%

  9. Estimated variability of National Atmospheric Deposition Program/Mercury Deposition Network measurements using collocated samplers

    Science.gov (United States)

    Wetherbee, G.A.; Gay, D.A.; Brunette, R.C.; Sweet, C.W.

    2007-01-01

    The National Atmospheric Deposition Program/Mercury Deposition Network (MDN) provides long-term, quality-assured records of mercury in wet deposition in the USA and Canada. Interpretation of spatial and temporal trends in the MDN data requires quantification of the variability of the MDN measurements. Variability is quantified for MDN data from collocated samplers at MDN sites in two states, one in Illinois and one in Washington. Median absolute differences in the collocated sampler data for total mercury concentration are approximately 11% of the median mercury concentration for all valid 1999-2004 MDN data. Median absolute differences are between 3.0% and 14% of the median MDN value for collector catch (sample volume) and between 6.0% and 15% of the median MDN value for mercury wet deposition. The overall measurement errors are sufficiently low to resolve between NADP/MDN measurements by ??2 ng??l-1 and ??2 ????m-2?? year-1, which are the contour intervals used to display the data on NADP isopleths maps for concentration and deposition, respectively. ?? Springer Science+Business Media B.V. 2007.

  10. Atmospheric Sulfur Deposition on Farmland in East China

    Institute of Scientific and Technical Information of China (English)

    WANG Ti-Jian; YANG Hao-Ming; GAO Li-Jie; ZHANG Yan; HU Zheng-Yi; XU Cheng-Kai

    2005-01-01

    Atmospheric sulfur deposition onto typical farmland in East China was investigated using both field measurements and numerical modeling. The field measurements were conducted at the Experiment Station of Red Soil Ecology, Chinese Academy of Sciences, 10 km from Yingtan, Jiangxi Province, East China, between November 1998 and October 1999, and at the Changshu Ecological Experiment Station, Chinese Academy of Sciences, in a rapidly developing region of Jiangsu Province, East China, between April 2001 and March 2002. The regional acid deposition model system (RegADMS), in which the dry deposition velocities of SO2 and sulfate aerosols (SO42-) were estimated using a big-leaf resistance analogy model, was applied to simulate air sulfur deposition over East China and sulfur deposition onto lands of different use types in East China. The wet scavenging coefficients were parameterized in terms of precipitation rate, and the effect of sub-grid processes due to inhomogeneous land use on dry deposition velocity was also included. Results of the field measurements showed that over 83% of the total sulfur deposition at the Yingtan site was dry deposition, while at the Changshu site42% was dry deposition. The total sulfur deposition was much larger at the Yingtan site than at the Changshu site, which suggested contrasting air pollution and meteorological situations. The modeling results revealed that the total annual sulfur deposition over East China was 1.88 Mt, of which 72.8% was deposited onto farmland, and dry deposition accounted for 43% of the total sulfur deposited. The modeling results were generally in agreement with those from the observations.Overall, this study suggested that atmospheric sulfur deposition played an important role in the soil sulfur balance, which could have a significant effect on agricultural ecosystems in the study region.

  11. The power source effect on SiOx coating deposition by plasma enhanced chemical vapor deposition

    International Nuclear Information System (INIS)

    SiOx coatings were prepared by capacitively coupled plasma enhanced chemical vapor deposition on polyethyleneterephtalate substrates in 23 kHz middle-frequency and radio frequency power supplies, respectively, where hexamethyldisiloxane was used as gas source. The influences of discharge conditions on gas phase intermediate species and active radicals for SiOx formation was investigated by mass spectrometry as real-time in-situ diagnosis. The deposited SiOx coating chemical structures were also analyzed by Fourier transform infrared spectroscopy. Meanwhile, the film barrier property, oxygen transmission rate, was measured at 23 oC and 50% humidity circumstance. The better barrier property was obtained in the MF power source depositing SiOx coated PET.

  12. Gas permeation barriers deposited by atmospheric pressure plasma enhanced atomic layer deposition

    International Nuclear Information System (INIS)

    This paper reports on aluminum oxide (Al2O3) thin film gas permeation barriers fabricated by atmospheric pressure atomic layer deposition (APPALD) using trimethylaluminum and an Ar/O2 plasma at moderate temperatures of 80 °C in a flow reactor. The authors demonstrate the ALD growth characteristics of Al2O3 films on silicon and indium tin oxide coated polyethylene terephthalate. The properties of the APPALD-grown layers (refractive index, density, etc.) are compared to that deposited by conventional thermal ALD at low pressures. The films films deposited at atmospheric pressure show water vapor transmission rates as low as 5 × 10−5 gm−2d−1

  13. Characterization of nanocarbon deposited on insulator substrate by alcohol chemical vapor deposition

    Science.gov (United States)

    Tsujimoto, Marina; Murata, Hidenobu; Tachibana, Masaru

    2016-10-01

    Single-layer-graphene-like nanocarbon materials were directly deposited on c-plane sapphire substrates by thermal chemical vapor deposition with ethanol as a carbon source. Scanning electron microscopy (SEM) images show that the deposited materials have sheetlike grains of around 100 nm diameter. Most of them have “hills” with 32 nm diameter on the grains. According to atomic force microscopy (AFM) observation, the height of the sheetlike grains is below 1 nm, which is comparable to that of single-layer graphene, while the hills have a height of several nm. Raman spectra show that the material is similar to graphitic nanocarbon, which has a strong D band. This result implies that there are a number of defects in the nanocarbon materials.

  14. Similarities and Differences between the Sandstone-Hosted Jinding Zn-Pb Deposit and MVT Deposits

    Science.gov (United States)

    Chi, G.; Xue, C.

    2009-05-01

    The Jinding Zn-Pb deposit (Lanping basin, Yunnan, China) is the largest sandstone-hosted Zn-Pb deposit in the world, having a total reserve of approximately 220 Mt of ore grading 6.1% Zn and 1.3 Pb%. The sedimentary rocks in the Lanping basin were formed in continental environments and were subject to strong deformation during the Himalayan orogeny. The orebodies are hosted in Cretaceous and Paleocene sandstones and pebbly sandstones which formed a structural dome (the Jinding dome) near a regional, high- angle normal fault (the Pijiang fault). The ores can be divided into two types, the sandstone-type and breccia- type. The former consists of fine-grained sphalerite-galena-pyrite-marcasite disseminations in sandstones, and the latter includes sphalerite-galena-pyrite-marcasite disseminations in the matrix and celestite-pyrite- marcasite-sphalerite-galena-calcite filling fractures and cavities. Colloform textures are common in the breccia-type ores, which are associated with sand veins or dykes cemented by sulfides. Breccia-type ores commonly contain solid bitumen, and freshly opened sandstone-type ores have an oily smell. Oil inclusions are common in both types of ores. CO2-CH4-light hydrocarbon inclusions were found in celestite, sphalerite, authigenic quartz, and calcite. Homogenization temperatures of aqueous inclusions range from about 60 to 300 degree C, and salinities range from 1 to 25 wt.% NaCl equivalent. There is a trend of decreasing temperature and increasing salinities away from the Pijiang fault. Delta 34S (CDT) of sulfides range from -32 to 0 per mil. Noble gas isotopes of fluid inclusions and Pb isotopes of sulfides indicate both mantle and crustal sources. It is proposed that the mineralization resulted from mixing between a high-temperature, low-salinity, deep-seated fluid and a relatively high-salinity, low-temperature, basinal fluid. The former ascended along the Pijiang fault and spread westward, and the latter migrated before and during

  15. ZnS thin film deposited with chemical bath deposition process directed by different stirring speeds

    International Nuclear Information System (INIS)

    In this combined film thickness, scanning electron microscopy (SEM), X-ray diffraction and optical properties study, we explore the effects of different stirring speeds on the growth and optical properties of ZnS film deposited by CBD method. From the disclosed changes of thickness of ZnS film, we conclude that film thickness is independent of the stirring speeds in the heterogeneous process (deposition time less than 40 min), but increases with the stirring speeds and/or deposition time increasing in the homogeneous process. Grazing incident X-ray diffraction (GIXRD) and the study of optical properties disclosed that the ZnS films grown with different stirring speeds show partially crystallized film and exhibit good transmittance (70-88% in the visible region), but the stirring speeds cannot give much effects on the structure and optical properties in the homogeneous process.

  16. Deposition and characterization of Ru thin films prepared by metallorganic chemical vapor deposition

    CERN Document Server

    Kang, S Y; Lee, S K; Hwang, C S; Kim, H J

    2000-01-01

    Ru thin films were deposited at 300 approx 400 .deg. C by using Ru(C sub 5 H sub 4 C sub 2 H sub 5) sub 2 (Ru(EtCp) sub 2) as a precursor and low-pressure metalorganic chemical vapor deposition. The addition of O sub 2 gas was essential to form Ru thin films. The deposition rates of the films were about 200 A/min. For low oxygen addition and high substrate temperature, RuO sub 2 phases were formed. Also, thermodynamic calculations showed that all the supplied oxygen was consumed to oxidize carbon and hydrogen, cracked from the precursor ligand, rather than Ru. Thus, metal films could be obtained There was an optimum oxygen to precursor ratio at which the pure Ru phase could be obtained with minimum generation of carbon and RuO sub 2

  17. Hardness and stress of amorphous carbon film deposited by glow discharge and ion beam assisting deposition

    CERN Document Server

    Marques, F C

    2000-01-01

    The hardness and stress of amorphous carbon films prepared by glow discharge and by ion beam assisting deposition are investigated. Relatively hard and almost stress free amorphous carbon films were deposited by the glow discharge technique. On the other hand, by using the ion beam assisting deposition, hard films were also obtained with a stress of the same order of those found in tetrahedral amorphous carbon films. A structural analysis indicates that all films are composed of a sp sup 2 -rich network. These results contradict the currently accepted concept that both stress and hardness are only related to the concentration of sp sup 3 sites. Furthermore, the same results also indicate that the sp sup 2 sites may also contribute to the hardness of the films.

  18. Gas permeation barriers deposited by atmospheric pressure plasma enhanced atomic layer deposition

    Energy Technology Data Exchange (ETDEWEB)

    Hoffmann, Lukas, E-mail: lhoffmann@uni-wuppertal.de; Theirich, Detlef; Hasselmann, Tim; Räupke, André; Schlamm, Daniel; Riedl, Thomas, E-mail: t.riedl@uni-wuppertal.de [Institute of Electronic Devices, University of Wuppertal, Rainer-Gruenter-Str. 21, 42119 Wuppertal (Germany)

    2016-01-15

    This paper reports on aluminum oxide (Al{sub 2}O{sub 3}) thin film gas permeation barriers fabricated by atmospheric pressure atomic layer deposition (APPALD) using trimethylaluminum and an Ar/O{sub 2} plasma at moderate temperatures of 80 °C in a flow reactor. The authors demonstrate the ALD growth characteristics of Al{sub 2}O{sub 3} films on silicon and indium tin oxide coated polyethylene terephthalate. The properties of the APPALD-grown layers (refractive index, density, etc.) are compared to that deposited by conventional thermal ALD at low pressures. The films films deposited at atmospheric pressure show water vapor transmission rates as low as 5 × 10{sup −5} gm{sup −2}d{sup −1}.

  19. MEAD Marine Effects of Atmospheric Deposition

    Science.gov (United States)

    Jickells, T.; Spokes, L.

    2003-04-01

    The coastal seas are one of the most valuable resources on the planet but they are threatened by human activity. We rely on the coastal area for mineral resources, waste disposal, fisheries and recreation. In Europe, high population densities and high levels of industrial activity mean that the pressures arising from these activities are particularly acute. One of the main problems concerning coastal seas is the rapid increase in the amounts of nitrogen-based pollutants entering the water. They come from many sources, the most important ones being traffic, industry and agriculture. These pollutants can be used by algae as nutrients. The increasing concentrations of these nutrients have led to excessive growth of algae, some of which are harmful. When algae die and decay, oxygen in the water is used up and the resulting lower levels of oxygen may lead to fish kills. Human activity has probably doubled the amount of chemically and biologically reactive nitrogen present globally. In Europe the increases have been greater than this, leading to real concern over the health of coastal waters. Rivers have, until recently, been thought to be the most important source of reactive nitrogen to the coastal seas but we now know that inputs from the atmosphere are large and can equal, or exceed, those from the rivers. Our initial hypothesis was that atmospheric inputs are important and potentially different in their effect on coastal ecosystems to riverine inputs and hence require different management strategies. However, we had almost no information on the direct effects of atmospheric deposition on marine ecosystems, though clearly such a large external nitrogen input should lead to enhanced phytoplankton growth The aim of this European Union funded MEAD project has been to determine how inputs of nitrogen from the atmosphere affect the chemistry and biology of coastal waters. To try to answer this, we have conducted field experiments in the Kattegat, an area where we know

  20. Ecological effects of atmospheric nitrogen deposition on soil enzyme activity

    Institute of Scientific and Technical Information of China (English)

    WANG Cong-yan; Lv Yan-na; LIU Xue-yan Liu; WANG Lei

    2013-01-01

    The continuing increase in human activities is causing global changes such as increased deposition of atmospheric nitrogen.There is considerable interest in understanding the effects of increasing atmospheric nitrogen deposition on soil enzyme activities,specifically in terms of global nitrogen cycling and its potential future contribution to global climate change.This paper summarizes the ecological effects of atmospheric nitrogen deposition on soil enzyme activities,including size-effects,stage-effects,site-effects,and the effects of different levels and forms of atmospheric nitrogen deposition.We discuss needs for further research on the relationship between atmospheric nitrogen deposition and soil enzymes.

  1. Thallium in Low Temperature Ore Deposits,China

    Institute of Scientific and Technical Information of China (English)

    张忠; 张宝跺

    1996-01-01

    is paper deals with thallium in typical low-temperature deposits of Au,Tl,As,Sb and Hg in South China with respect to its mode of occurrence,minerals and geochemical correlations with many other coexisting major and trace elements,Criteria are proposed for identifying independent thallium deposits and thallium-bearing deposits and the Nanhnu realgar deposit is classified for the first time as an independent thallium deposit,Tl,F.Cl.I and B are suggested as indicators for low-temperature mineralization with examples furnished for their applications.

  2. Deposit Insurance and Bank Liquidity: Does Ownership Structure Matter?

    Directory of Open Access Journals (Sweden)

    Irwan Trinugroho

    2016-07-01

    Full Text Available We examine how the level deposit insurance coverage affects bank liquidity. We also test the role of ownership in the relationship between deposit insurance coverage and bank liquidity. This study uses quarterly data of Indonesian banks from Q1:2002 - Q2:2008. We argue that the presence of explicit deposit insurance changes a bank‘s behavior in liquidity management in the form of decreasing asset liquidity. We find some evidence on the negative impact of deposit insurance coverage on bank liquidity. However, little is found on the role of ownership structure. The credibility of deposit insurance system and implicit guarantee are the main policy implications.

  3. Cigar Lake, an original method for an exceptional deposit

    International Nuclear Information System (INIS)

    In 1976, the discovery of the high grade Deposit at Cluff Lake in the north of the province of Saskatchewan (Canada) opened new prospects in uranium deposits, which in turn quickly led to the discovery of exceptional deposits both in terms of grade (up 10 % in metal uranium) and tonnage (150, 000 tons of metal per deposit and more). Among these deposits are Key Lake, Cigar Lake, Midwest, MacClean, and more recently, Mac Arthur. These discoveries as well as future ones make the north of Saskatchewan the world's greatest and most interesting uranium-producing province. (authors)

  4. Atmospheric heavy metal deposition in Europe

    Energy Technology Data Exchange (ETDEWEB)

    Ruehling, Aa. (ed.)

    1994-03-01

    Atmospheric heavy metal deposition in Europe including 21 countries was monitored by the moss technique. The objectives of the project were to characterise qualitatively and quantitatively the regional atmospheric deposition pattern of heavy metals in background areas in Europe, to indicat the location of important heavy metal pollution sources. Samples of mainly the moss species Pleurozium schreberi, Hylocomium splendens and Hypnum cupresiforme were collected during the summertime 1990. The total concentrations of arsenic, cadmium, chromium, copper, iron, lead, nickel, vanadium and zinc were determined and the results presented in the form of coloured contour maps of Europe. In the Nordic countries and adjacent areas the regional deposition pattern of all the metals shows a decreasing gradient from relatively high values in the southern parts of Scandinavia to low values towards the North. A significant decreas. in the concentrations of most elements was found in this area during the last 10-20 years. Important local enhancements of the concentrations in moss were found superimposed on the regional background pattern, especially at the great smelting combinates in Nikel, Zapolyarnyj and Monchegorsk in Russia in the western part of the Kola Peninsula. Higher levels of metals are found at Mazeikiai (oil refinery) in Lithuania, close to Liepaja (steel mill) and Riga in Latvia and in the industrial north-eastern area of Estonia and adjacent area of Russia. Higher levels of metals were found in the metropolitan area of St. Petersburg. In Central Europe, Poland, and the Czech Republic have numerous sources of air pollution, as well as area in Germany. The Netherlands is particularly affected by pollution from Belgium and western Germany. The Environmental Monitoring and Data Group in the Nordic Countries would like the next survey of heavy metals, including mercury, in moss to take place in 1995. (EG) (45 refs.)

  5. Ash deposition impacts in the power industry

    International Nuclear Information System (INIS)

    There have been great strides in understanding the fundamental underpinnings of the slagging and fouling phenomena. Unfortunately as fuel quality changes due to coal pricing, mine closures, government regulations, market forces, etc., boilers and boiler operators continue to be plagued by poorer operating performance than desired. While improvements have been made, the need to address fundamental coal quality issues and how they affect deposition, emissions, handling, and combustion continues to be relevant. This paper presents the results of a study to assess how prevalent coal quality issues are to the power generation industry. A survey of selected EPRI members was made to determine the major areas where coal quality effects power generation and a reliability and availability assessment of the NERC GADS database for the years 1995 to 2004 was completed. This database was used to determine the lost generation through either forced outages, forced derates or planned outages and derates due to coal quality or slagging and fouling issues. The results clearly demonstrated that slagging, fouling, corrosion and fuel blending continue to be the leading coal quality concerns of utility personnel. Ash chemistry resulting from fuel blending and new coals being utilized continue to be the main area for needed utility support. A minimum estimated annual economic impact of over $1.2 billion was calculated for all coal- and lignite-fired boilers in the US based on coal quality and deposition occurrences. While this annual economic loss is huge, these outages and derates account for only about 1.6% of the total number of outages and derate occurrences and 2.5% of the total lost MW-hour generation. An annual evaluation of the coal quality and deposition-based outages and derates did not show a clear trend. In fact, the coal quality-based outages and derates generally increased over the ten-year period. (author)

  6. Bulk sulfur (S) deposition in China

    Science.gov (United States)

    Liu, Lei; Zhang, Xiuying; Wang, Shanqian; Zhang, Wuting; Lu, Xuehe

    2016-06-01

    A systematic dataset of an observation network on a national scale has been organized to investigate the spatial distribution of bulk sulfur (S) deposition (Sdep) throughout China during 2000-2013, representing by far the most detailed data set to track the bulk sulfur deposition throughout China since 2000. Such a dataset is needed for ecosystem studies and for developing emission control policies. Bulk Sdep values showed great variations, ranging from 2.17 to 70.55 kg ha-1 y-1, with an average of 22.99 kg ha-1 y-1. The average rate of bulk Sdep located in East Coastal region (35.97 kg ha-1 y-1), Middle Yangtze region (57.90 kg ha-1 y-1), Middle Yellow River region (23.42 kg ha-1 y-1), North Coastal region (42.19 kg ha-1 y-1), Northeast region (34.28 kg ha-1 y-1), South Coastal region (36.97 kg S ha-1 y-1), Southwest region (33.85 kg ha-1 y-1) was 4.50, 7.24, 2.93, 5.28, 4.29, 4.63 and 4.24 times than that in Northwest region (7.99 kg ha-1 y-1). Bulk Sdep over China was mainly from fossil fuel combustion (76.96%), biomass burning (7.64%), crust (6.22%), aged sea salt (5.48%) and agriculture (3.68%). A systematic observation network on a national scale should be established to conduct a long-term monitoring atmospheric Sdep (including wet and dry deposition), based on exiting ecological stations administrated by different departments in China.

  7. Quality study of a fedspar deposit

    Directory of Open Access Journals (Sweden)

    Taboada, J.

    2000-12-01

    Full Text Available This work describes a pegmatite mineral deposit composed by some veins of a length between 50 and 800 meters and a width of almost 15 meters. With the purpose to evaluate the potential exploitation, we have characterized the quality of the selling product, through a sampling procedure, granulometric classification, magnetic separation, flotation process and mineralogical analysis. In order to establish the more able flotation process, we have tested different methods, that we also include here. Later on, and with the finality to establish the selling feldspar percentage in the deposit, we realized a geostatic study in order to identify, not only the different qualities but also its distribution in the deposit.

    Este trabajo describe un yacimiento de pegmatita compuesto por varios filones, que varían entre 50 y 800 metros de longitud y casi 15 metros de ancho. Con el fin de evaluar el potencial de explotación, se caracteriza la calidad del producto vendible. Esto se lleva a cabo mediante un procedimiento de muestreo, clasificación granulométrica, separación magnética, proceso de flotación y análisis mineralógico. Para establecer el proceso de flotación más eficaz, se ha experimentado con varios procedimientos, cuya breve descripción se incluye. Posteriormente, y con el fin de establecer el porcentaje de feldespato vendible en el yacimiento, se realizó un estudio geoestadístico para identificar tanto las categorías de calidad como su distribución en el yacimiento.

  8. Comparison of lanthanum substituted bismuth titanate (BLT) thin films deposited by sputtering and pulsed laser deposition

    Energy Technology Data Exchange (ETDEWEB)

    Besland, M.P. [Institut des Materiaux Jean Rouxel, Universite de Nantes, UMR CNRS 6502, 2 rue de la Houssiniere, B.P. 32229, 44322, Nantes cedex 3 (France)]. E-mail: Marie-Paule.Besland@cnrs-imn.fr; Djani-ait Aissa, H. [Division milieux Ionises et lasers, Centre de Developpement des Technologies Avancees CDTA, Baba Hassen Alger, Algerie (Algeria); Barroy, P.R.J. [Institut des Materiaux Jean Rouxel, Universite de Nantes, UMR CNRS 6502, 2 rue de la Houssiniere, B.P. 32229, 44322, Nantes cedex 3 (France); Lafane, S. [Division milieux Ionises et lasers, Centre de Developpement des Technologies Avancees CDTA, Baba Hassen Alger, Algerie (Algeria); Tessier, P.Y. [Institut des Materiaux Jean Rouxel, Universite de Nantes, UMR CNRS 6502, 2 rue de la Houssiniere, B.P. 32229, 44322, Nantes cedex 3 (France); Angleraud, B. [Institut des Materiaux Jean Rouxel, Universite de Nantes, UMR CNRS 6502, 2 rue de la Houssiniere, B.P. 32229, 44322, Nantes cedex 3 (France); Richard-Plouet, M. [Institut des Materiaux Jean Rouxel, Universite de Nantes, UMR CNRS 6502, 2 rue de la Houssiniere, B.P. 32229, 44322, Nantes cedex 3 (France); Brohan, L. [Institut des Materiaux Jean Rouxel, Universite de Nantes, UMR CNRS 6502, 2 rue de la Houssiniere, B.P. 32229, 44322, Nantes cedex 3 (France); Djouadi, M.A. [Institut des Materiaux Jean Rouxel, Universite de Nantes, UMR CNRS 6502, 2 rue de la Houssiniere, B.P. 32229, 44322, Nantes cedex 3 (France)

    2006-01-20

    Bi{sub 4-x}La {sub x}Ti{sub 3}O{sub 12} (BLT {sub x}) (x = 0 to 1) thin films were grown on silicon (100) and platinized substrates Pt/TiO{sub 2}/SiO{sub 2}/Si using RF diode sputtering, magnetron sputtering and pulsed laser deposition (PLD). Stoichiometric home-synthesized targets were used. Reactive sputtering was investigated in argon/oxygen gas mixture, with a pressure ranging from 0.33 to 10 Pa without heating the substrate. PLD was investigated in pure oxygen, at a chamber pressure of 20 Pa for a substrate temperature of 400-440 deg. C. Comparative structural, chemical, optical and morphological characterizations of BLT thin films have been performed by X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), Energy Dispersive Spectroscopy (EDS), X-Ray Photoelectron Spectroscopy (XPS), Spectro-ellipsometric measurements (SE) and Atomic Force Microscopy (AFM). Both sputtering techniques allow to obtain uniform films with thickness ranging from 200 to 1000 nm and chemical composition varying from (Bi,La){sub 2} Ti{sub 3} O{sub 12} to (Bi,La){sub 4.5}Ti{sub 3}O{sub 12}, depending on deposition pressure and RF power. In addition, BLT films deposited by magnetron sputtering, at a pressure deposition ranging from 1.1 to 5 Pa, were well-crystallized after a post-deposition annealing at 650 deg. C in oxygen. They exhibit a refractive index and optical band gap of 2.7 and 3.15 eV, respectively. Regarding PLD, single phase and well-crystallized, 100-200 nm thick BLT films with a stoichiometric (Bi,La){sub 4}Ti{sub 3}O{sub 12} chemical composition were obtained, exhibiting in addition a preferential orientation along (200). It is worth noting that BLT films deposited by magnetron sputtering are as well-crystallized than PLD ones.

  9. Characterization of titanium oxynitride films deposited by low pressure chemical vapor deposition using amide Ti precursor

    Energy Technology Data Exchange (ETDEWEB)

    Song Xuemei; Gopireddy, Deepthi [Department of Chemical Engineering, University of Illinois at Chicago, Chicago, Illinois 60607 (United States); Takoudis, Christos G. [Department of Chemical Engineering, University of Illinois at Chicago, Chicago, Illinois 60607 (United States); Department of Bioengineering, University of Illinois at Chicago, Chicago, Illinois 60607 (United States)], E-mail: takoudis@uic.edu

    2008-07-31

    In this study, we investigate the use of an amide-based Ti-containing precursor, namely tetrakis(diethylamido)titanium (TDEAT), for TiN{sub x}O{sub y} film deposition at low temperature. Traditionally, alkoxide-based Ti-containing precursor, such as titanium tetra-isopropoxide (TTIP), along with NH{sub 3} is used for titanium oxynitride (TiN{sub x}O{sub y}) film deposition. When TTIP is used, at low temperatures it is difficult to form TiN{sub x}O{sub y} films with high N/O ratios. In this study, by using TDEAT, TiN{sub x}O{sub y} films are deposited on H-passivated Si (100) substrates in a cold wall reactor at 300 {sup o}C and 106 Pa. Rutherford backscattering spectroscopy analysis shows nitrogen incorporation in the TiN{sub x}O{sub y} films to be as high as 28 at.%. X-ray photoelectron spectroscopy analysis of as-deposited films confirms the formation of{sub .} TiN{sub x}O{sub y}, while Fourier transform infrared and Raman spectra indicate that the films have amorphous structure. Moreover, there is no detectable bulk carbon impurity and no SiO{sub 2} formation at the TiN{sub x}O{sub y}/Si interface. Upon annealing the as-deposited films in air at 750 deg. C for 30 min, they oxidize to TiO{sub 2} and crystallize to form a rutile structure with a small amount of anatase phase. Based on these results, TDEAT appears to be a promising precursor for both TiN{sub x}O{sub y} and TiO{sub 2} film deposition.

  10. Comparison of lanthanum substituted bismuth titanate (BLT) thin films deposited by sputtering and pulsed laser deposition

    International Nuclear Information System (INIS)

    Bi4-xLa xTi3O12 (BLT x) (x = 0 to 1) thin films were grown on silicon (100) and platinized substrates Pt/TiO2/SiO2/Si using RF diode sputtering, magnetron sputtering and pulsed laser deposition (PLD). Stoichiometric home-synthesized targets were used. Reactive sputtering was investigated in argon/oxygen gas mixture, with a pressure ranging from 0.33 to 10 Pa without heating the substrate. PLD was investigated in pure oxygen, at a chamber pressure of 20 Pa for a substrate temperature of 400-440 deg. C. Comparative structural, chemical, optical and morphological characterizations of BLT thin films have been performed by X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), Energy Dispersive Spectroscopy (EDS), X-Ray Photoelectron Spectroscopy (XPS), Spectro-ellipsometric measurements (SE) and Atomic Force Microscopy (AFM). Both sputtering techniques allow to obtain uniform films with thickness ranging from 200 to 1000 nm and chemical composition varying from (Bi,La)2 Ti3 O12 to (Bi,La)4.5Ti3O12, depending on deposition pressure and RF power. In addition, BLT films deposited by magnetron sputtering, at a pressure deposition ranging from 1.1 to 5 Pa, were well-crystallized after a post-deposition annealing at 650 deg. C in oxygen. They exhibit a refractive index and optical band gap of 2.7 and 3.15 eV, respectively. Regarding PLD, single phase and well-crystallized, 100-200 nm thick BLT films with a stoichiometric (Bi,La)4Ti3O12 chemical composition were obtained, exhibiting in addition a preferential orientation along (200). It is worth noting that BLT films deposited by magnetron sputtering are as well-crystallized than PLD ones

  11. Correction of deposition predictions with data assimilation

    International Nuclear Information System (INIS)

    Model predictions for rapid assessment and prognosis of possible radiological consequences after an accidental release of radionuclides play an important role in nuclear emergency management. Radiological measurements (e. g., dose rate measurements) can be used to improve such model predictions. This paper describes a method for combining model predictions and measurements (data assimilation) in the deposition model of the European radiological decision support system RODOS. The data assimilation approach is based on the Ensemble Kalman Filter, a Monte Carlo variant of the Kalman filter. (orig.)

  12. Iron-sulfide crystals in probe deposits

    DEFF Research Database (Denmark)

    Laursen, Karin; Frandsen, Flemming

    1998-01-01

    Iron-sulfides were observed in deposits collected on a probe inserted at the top of the furnace of a coal-fired power station in Denmark. The chemical composition of the iron-sulfides is equivalent to pyrrhotite (FeS). The pyrrhotites are present as crystals and, based on the shape of the crystals......: (1) impact of low viscous droplets of iron sulfide; and (2) sulfur diffusion. Previous research on the influence of pyrite on slagging focused on the decomposition of pyrite into pyrrhotite and especially on the oxidation stage of this product during impact on the heat transfer surfaces...

  13. DEPOSITION CARBON NANOSTRUCTURES BY SURFATRON GENERATED DISCHARGE

    Directory of Open Access Journals (Sweden)

    Marina Davydova

    2014-12-01

    Full Text Available Carbon nanostructures were deposited by surface wave discharge using various Ar/CH4/ CO2 gas mixture ratios. The morphology was controlled by adjusting of gas concentration and was investigated by scanning electron microscopy (SEM. Also, the influence of the low temperature plasma treatment and process time on the wettability of the diamond films has been studied. The results indicate that for hydrogen termination of diamond surface indicate that the temperature as low as 400°C and treatment time of 15 min is sufficient to attain the p-type surface conductivity of diamond.

  14. Orientation specific deposition of mesoporous particles

    Directory of Open Access Journals (Sweden)

    Tomas Kjellman

    2014-11-01

    Full Text Available We present a protocol for a facile orientation specific deposition of plate-like mesoporous SBA-15 silica particles onto a surface (mesopores oriented normal to surface. A drop of an aqueous dispersion of particles is placed on the surface and water vaporizes under controlled relative humidity. Three requirements are essential for uniform coverage: particle dispersion should not contain aggregates, a weak attraction between particles and surface is needed, and evaporation rate should be low. Aggregates are removed by stirring/sonication. Weak attraction is realized by introducing cationic groups to the surface. Insight into the mechanisms of the so-called coffee stain effect is also provided.

  15. Mixture for removing tar and paraffin deposits

    Energy Technology Data Exchange (ETDEWEB)

    kamenshchikov, F.A.; Frolov, M.A.; Golovin, I.N.; Khusainov, Z.M.; Smirnov, Ya.L.; Suchkov, B.M.

    1981-05-23

    Mixture is claimed for removing tar and paraffin deposits (TPD) on the basis of the butyl-benzene fraction (BBF), which is intended to more efficiently remove TPD from the surface of refinery equipment, additionally has piperylene, isoprene and isoamine with the following ratio of the components: piperylene, 19-31%; isoprene, 8-12%; isoamines, 8-12%, while BBF, the rest. The efficiency of the given compositions was assessed by the rate at which the plates were cleaned of TPD and pure commercial paraffin. It has been shown that BBF dissolves 4-6 times faster in the given mixture than in BBF and pyperylene.

  16. Pulsed laser deposition of liquid crystals

    OpenAIRE

    Gonzalo de los Reyes, José; Dyer, P. E.; Hird, M.

    1997-01-01

    Thin films of 4-cyano-4’-pentylbiphenyl ~5CB! liquid crystal have been fabricated by pulsed laser deposition. The suitability of different lasers ~ArF, KrF and CO2) has been investigated over a range of fluence using visible-UV and infrared absorption and optical microscopy to characterise the films. High performance liquid chromatography ~HPLC! and matrix assisted laser desorption ionization mass spectroscopy ~MALDI-MS! were used to assess the extent of decomposition of the films. The result...

  17. Stability of nanocrystalline electrochemically deposited layers

    DEFF Research Database (Denmark)

    Pantleon, Karen; Somers, Marcel A. J.

    2009-01-01

    of electrodeposited components, which can be beneficial, as for the electrical conductivity of copper interconnect lines, or detrimental, as for reduced strength of nickel in MEMS applications. The present work reports on in-situ studies of the microstructure stability of as-deposited nanocrystalline Cu-, Ag- and Ni...... found to occur for Ag-layers as well. Contrary to Cu and Ag, electrodeposited Ni-layers can be stable up to about 450 K. Similarities and characteristic differences of the mechanisms and kinetics of microstructure evolution in the various electrodeposits are discussed....

  18. Determination of electroless deposition by chemical nickeling

    Directory of Open Access Journals (Sweden)

    M. Badida

    2013-07-01

    Full Text Available Increasing of technical level and reliability of machine products in compliance with the economical and ecological terms belongs to the main trends of the industrial development. During the utilisation of these products there arise their each other contacts and the interaction with the environment. That is the reason for their surface degradation by wear effect, corrosion and other influences. The chemical nickel-plating allows autocatalytic deposition of nickel from water solutions in the form of coherent, technically very profitable coating without usage of external source of electric current. The research was aimed at evaluating the surface changes after chemical nickel-plating at various changes of technological parameters.

  19. Plasma distribution of cathodic ARC deposition system

    Energy Technology Data Exchange (ETDEWEB)

    Anders, S.; Raoux, S.; Krishnan, K.; MacGill, R.A.; Brown, I.G. [Lawrence Berkeley National Lab., CA (United States)

    1996-08-01

    The plasma distribution using a cathodic arc plasma source with and without magnetic macroparticle filter has been determined by depositing on a transparent plastic substrate and measuring the film absorption. It was found that the width of the distribution depends on the arc current, and it also depends on the cathode material which leads to a spatial separation of the elements when an alloy cathode is used. By applying a magnetic multicusp field near the exit of the magnetic filter, it was possible to modify the plasma distribution and obtain a flat plasma profile with a constant and homogeneous elemental distribution.

  20. Biocompatibility of chemical-vapour-deposited diamond.

    Science.gov (United States)

    Tang, L; Tsai, C; Gerberich, W W; Kruckeberg, L; Kania, D R

    1995-04-01

    The biocompatibility of chemical-vapour-deposited (CVD) diamond surfaces has been assessed. Our results indicate that CVD diamond is as biocompatible as titanium (Ti) and 316 stainless steel (SS). First, the amount of adsorbed and 'denatured' fibrinogen on CVD diamond was very close to that of Ti and SS. Second, both in vitro and in vivo there appears to be less cellular adhesion and activation on the surface of CVD diamond surfaces compared to Ti and SS. This evident biocompatibility, coupled with the corrosion resistance and notable mechanical integrity of CVD diamond, suggests that diamond-coated surfaces may be highly desirable in a number of biomedical applications. PMID:7654876