Sample records for athabasca deposit

  1. Tracing industrial sulfur emissions in atmospheric sulfate deposition in the Athabasca Oil Sands Region, Alberta, Canada (United States)

    Bernadette C. Proemse; Bernhard. Mayer; Mark E. Fenn


    Anthropogenic S emissions in the Athabasca oil sands region (AOSR) in Alberta, Canada, affect SO4 deposition in close vicinity of industrial emitters. Between May 2008 and May 2009, SO4-S deposition was monitored using open field bulk collectors at 15 sites and throughfall collectors at 14 sites at distances between 3 and 113 km from one of the major emission stacks in...

  2. Estimating the sensitivity of forest soils to acid deposition in the Athabasca Oil Sands Region, Alberta

    Directory of Open Access Journals (Sweden)

    Julian AHERNE


    Full Text Available The Athabasca Oil Sands Region of northern Alberta is home to the largest source of S emissions in Canada, and some of the surrounding upland forests are located on acid-sensitive soils. The relative sensitivity of these ecosystems to acidic deposition is largely dependent upon the mineral weathering rate. Weathering rates were evaluated across a range of soils (n = 43 typical of the region using a soil texture approximation (STA and the PROFILE model. The STA was recalibrated for use in the region, and the weathering rates calculated with this method were used to calculate steady-state critical loads of acidity at 333 sites using the Simple Mass Balance (SMB Model and a critical chemical criterion for molar base cation (Ca2+, Mg2+, K+ to aluminium ratio of 10. Soils are dominated by quartz, with small quantities of slowly weatherable minerals, and consequently weathering rates are among the lowest in Canada (median = 11.5 meq m–2 y–1, resulting in very low critical loads. Atmospheric acid (S and N deposition varies considerably across the region, but in general is much lower than impacted areas of central Canada. Under conditions of complete N retention, 34% of the sites receive acid deposition in excess of their critical load; if all N deposition is leached, 62% of the sites are currently exceeded. Acid-sensitive soils in the region are at risk of acidifying due to pressures from industrialization associated with extraction of fossil fuels.

  3. Spatial and temporal patterns in trace element deposition to lakes in the Athabasca oil sands region (Alberta, Canada) (United States)

    Cooke, Colin A.; Kirk, Jane L.; Muir, Derek C. G.; Wiklund, Johan A.; Wang, Xiaowa; Gleason, Amber; Evans, Marlene S.


    The mining and processing of the Athabasca oil sands (Alberta, Canada) has been occurring for decades; however, a lack of consistent regional monitoring has obscured the long-term environmental impact. Here, we present sediment core results to reconstruct spatial and temporal patterns in trace element deposition to lakes in the Athabasca oil sands region. Early mining operations (during the 1970s and 1980s) led to elevated V and Pb inputs to lakes located order control over lake sediment base cation concentrations and overall lake sediment geochemical composition. Trace element concentrations generally did not exceed Canadian sediment quality guidelines, and no spatial or temporal trends were observed in the frequency of guideline exceedence. Our results demonstrate that early mining efforts had an even greater impact on trace element cycling than has been appreciated previously, placing recent monitoring efforts in a critical long-term context.

  4. Tracing industrial ammonium in atmospheric deposition in the Athabasca Oil Sands Region, Alberta, Canada (United States)

    Mayer, B.; Proemse, B. C.; Fenn, M. E.


    The expanding industrial development in the Athabasca oil sands region (AOSR) in northeastern Alberta, Canada, has raised concerns about increasing nitrogen (N) emissions from oil sands operations and their potential effects on the surrounding terrestrial and aquatic ecosystems. Stable isotope techniques may help to trace industrial emissions provided that they are isotopically distinct from background isotope ratios of atmospheric N compounds. Ammonium deposition rates (NH4-N) typically exceed nitrate deposition rates (NO3-N) in the AOSR (Proemse et al., 2013), suggesting that emissions of reduced nitrogen compounds play a significant role for the atmospheric nitrogen budget in the AOSR. We collected atmospheric ammonium in open field bulk deposition and throughfall using ion exchange resins over ~6 months time periods from summer 2007 to summer 2011 located at distances between 3 to 113 km to one of the major oil sands developments in the AOSR. Ammonium deposition rates and δ15N-NH4 values were determined using ion chromatography and the ammonium diffusion method (Sebilo et al., 2004) on resin extracts. Atmospheric ammonium deposition rates in open field bulk collectors and throughfall collectors ranged from 1.0 to 4.7 kg ha-1 yr-1 NH4-N, and from 1.0 to 18.3 kg ha-1 yr-1 NH4-N, respectively. δ15N-NH4 values varied from -6.3 to +14.8‰ with the highest δ15N values typically associated with elevated NH4-N deposition rates. δ15N-NH4 values of up to +20.1‰ were observed for industrially emitted NH4 in particulate matter (PM2.5) emissions (Proemse et al., 2012) suggesting that industrial NH3 and NH4 emissions are associated with elevated δ15N values providing a potential tracer. Applying a two-end-member mixing analysis using a background δ15N-NH4 value of -3.6‰ for summer and -3.2‰ for winter periods revealed that particularly sites within ~30 km radius from the main oil sands developments are significantly affected by industrial contributions to

  5. A multi-isotope approach for assessing industrial contributions to atmospheric nitrogen deposition in the Athabasca oil sands region in Alberta, Canada (United States)

    Bernadette C. Proemse; Bernhard Mayer; Mark E. Fenn; Christopher S. Ross


    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...

  6. Differential effects of high atmospheric N and S deposition on bog plant/lichen tissue and porewater chemistry across the Athabasca Oil Sands Region (United States)

    R. Kelman Wieder; Melanie A. Vile; Kimberli D. Scott; Cara M. Albright; Kelly J. McMillen; Dale H. Vitt; Mark E. Fenn


    Oil extraction and development activities in the Athabasca Oil Sands Region of northern Alberta, Canada, release NOx, SOx, and NHy to the atmosphere, ultimately resulting in increasing N and S inputs to surrounding ecosystems through atmospheric deposition. Peatlands are a major feature of the northern Alberta landscape, with bogs covering 6-10% of the land area, and...

  7. Multielement statistical evidence for uraniferous hydrothermal activity in sandstones overlying the Phoenix uranium deposit, Athabasca Basin, Canada (United States)

    Chen, Shishi; Hattori, Keiko; Grunsky, Eric C.


    The Phoenix U deposit, with indicated resources of 70.2 M lb U3O8, occurs along the unconformity between the Proterozoic Athabasca Group sandstones and the crystalline basement rocks. Principal component analysis (PCA) is applied to the compositions of sandstones overlying the deposit. Among PCs, PC1 accounts for the largest variability of U and shows a positive association of U with rare earth elements (REEs) + Y + Cu + B + Na + Mg + Ni + Be. The evidence suggests that U was dispersed into sandstones together with these elements during the uraniferous hydrothermal activity. Uranium shows an inverse association with Zr, Hf, Th, Fe, and Ti. Since they are common in detrital heavy minerals, such heavy minerals are not the major host of U. The elements positively associated with U are high in concentrations above the deposit, forming a "chimney-like" or "hump-like" distribution in a vertical section. Their enrichment patterns are explained by the ascent of basement fluids through faults to sandstones and the circulation of basinal fluids around the deposit. The Pb isotope compositions of whole rocks are similar to expected values calculated from the concentrations of U, Th, and Pb except for sandstones close to the deposit. The data suggest that in situ decay of U and Th is responsible for the Pb isotope compositions of most sandstones and that highly radiogenic Pb dispersed from the deposit to the proximal sandstones long after the mineralization. This secondary dispersion is captured in PC8, which has low eigenvalue. The data suggests that the secondary dispersion has minor effect on the overall lithogeochemistry of sandstones.

  8. 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


    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.

  9. Synchronous egress and ingress fluid flow related to compressional reactivation of basement faults: the Phoenix and Gryphon uranium deposits, southeastern Athabasca Basin, Saskatchewan, Canada (United States)

    Li, Zenghua; Chi, Guoxiang; Bethune, Kathryn M.; Eldursi, Khalifa; Thomas, David; Quirt, David; Ledru, Patrick


    Previous studies on unconformity-related uranium deposits in the Athabasca Basin (Canada) suggest that egress flow and ingress flow can develop along single fault systems at different stages of compressional deformation. This research aims to examine whether or not both ingress and egress flow can develop at the same time within an area under a common compressional stress field, as suggested by the reverse displacement of the unconformity surface by the basement faults. The study considers the Phoenix and Gryphon uranium deposits in the Wheeler River area in the southeastern part of the Athabasca Basin. Two-dimensional numerical modeling of fluid flow, coupled with compressional deformation and thermal effects, was carried out to examine the fluid flow pattern. The results show that local variations in the basement geology under a common compressional stress field can result in both egress and ingress flow at the same time. The fault zone at Phoenix underwent a relatively low degree of deformation, as reflected by minor reverse displacement of the unconformity, and egress flow developed, whereas the fault zone at Gryphon experienced a relatively high degree of deformation, as demonstrated by significant reverse displacement of the unconformity, and ingress flow was dominant. The correlation between strain development and location of uranium mineralization, as exemplified by Gryphon and Phoenix uranium deposits, suggests that the localization of dilation predicted by numerical modeling may represent favourable sites for uranium mineralization in the Athabasca Basin.

  10. The role of the thermal convection of fluids in the formation of unconformity-type uranium deposits: the Athabasca Basin, Canada (United States)

    Pek, A. A.; Malkovsky, V. I.


    In the global production of uranium, 18% belong to the unconformity-type Canadian deposits localized in the Athabasca Basin. These deposits, which are unique in terms of their ore quality, were primarily studied by Canadian and French scientists. They have elaborated the diagenetic-hydrothermal hypothesis of ore formation, which suggests that (1) the deposits were formed within a sedimentary basin near an unconformity surface dividing the folded Archean-Proterozoic metamorphic basement and a gently dipping sedimentary cover, which is not affected by metamorphism; (2) the spatial accommodation of the deposits is controlled by the rejuvenated faults in the basement at their exit into the overlying sedimentary sequence; the ore bodies are localized above and below the unconformity surface; (3) the occurrence of graphite-bearing rocks is an important factor in controlling the local structural mineralization; (4) the ore bodies are the products of uranium precipitation on a reducing barrier. The mechanism that drives the circulation of ore-forming hydrothermal solutions has remained one of the main unclear questions in the general genetic concept. The ore was deposited above the surface of the unconformity due to the upflow discharge of the solution from the fault zones into the overlying conglomerate and sandstone. The ore formation below this surface is a result of the downflow migration of the solutions along the fault zones from sandstone into the basement rocks. A thermal convective system with the conjugated convection cells in the basement and sedimentary fill of the basin may be a possible explanation of why the hydrotherms circulate in the opposite directions. The results of our computations in the model setting of the free thermal convection of fluids are consistent with the conceptual reasoning about the conditions of the formation of unique uranium deposits in the Athabasca Basin. The calculated rates of the focused solution circulation through the fault

  11. Assessment of multi-trophic changes in a shallow boreal lake simultaneously exposed to climate change and aerial deposition of contaminants from the Athabasca Oil Sands Region, Canada. (United States)

    Summers, Jamie C; Kurek, Joshua; Rühland, Kathleen M; Neville, Erin E; Smol, John P


    The Athabasca Oil Sands Region (AOSR) has been intensely developed for industrial bitumen extraction and upgrading since the 1980s. A paucity of environmental monitoring prior to development raises questions about baseline conditions in freshwater systems in the region and ecological responses to industrial activities. Further, climatic changes prompt questions about the relative roles of climate and industry in shaping aquatic ecosystems through time. We use aquatic bioindicators from multiple trophic levels, concentrations of petrogenic contaminants (dibenzothiophenes), and spectrally-inferred chlorophyll-a preserved in well-dated sediments of a closed-basin, shallow lake ~50km away from the main area of industry, in conjunction with climate observations, to assess how the biotic assemblages of a typical AOSR lake have changed during the past ~75years. We examine the contributions of the area's stressors in structuring aquatic communities. Increases in sedimentary measures of petrogenic contaminants provide clear evidence of aerial contaminant deposition from local industry since its establishment, while climate records demonstrate consistent warming and a recent period of reduced precipitation. Quantitative comparisons of biological assemblages from before and after the establishment of regional industry find significant (pchanges are not consistent with a threshold-type shift in response to the onset of regional industry. Rather, biotic assemblages from multiple trophic levels suggest transitions to an increasingly complex benthic environment and relatively warmer waters, which, like the increasing trends in inferred primary production, are consistent with a changing climate. These findings highlight the important role of climate conditions in regulating primary production and structuring aquatic communities in these shallow systems. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Evolution and origin of brines in proterozoic basins in the vicinity of the basement / cover unconformity. Application to uranium deposits in the Kombolgie (Australia) and Athabasca (Canada) basins; Evolution et origine des saumures dans les bassins proterozoiques au voisinage de la discordance socle/couverture. L'exemple de l'environnement des gisements d'uranium associes aux bassins Kombolgie (Australie) et Athabasca (Canada)

    Energy Technology Data Exchange (ETDEWEB)

    Derome, D


    The nature, evolution and origin of the fluids circulating at the basis of two Proterozoic sandstone basins (Kombolgie, Australia and Athabasca, Canada), associated with unconformity type uranium mineralization have been characterised. The coupling of several techniques (micro-thermometry, Raman, LIBS) for analysing individual fluid inclusions trapped in different quartz generations, sampled in the vicinity of Australian and Canadian uranium deposits, has led to the quantitative determination of the composition of the paleo-fluids which may have had a role in the genesis of these deposits. The P-T,x evolution of these fluids, in the vicinity of the interface between the basement and the sedimentary cover, has been reconstructed. The proposed fluid circulation model for the two basins is the following: - A sodium dominated chloride-rich brine (15-20 wt% NaCl + 4-12 wt% CaCl{sub 2}), highly oxidising (equilibrated with hematite) is responsible for the early diagenetic silicification. - The circulation of a calcium chloride-rich brine (25-30 wt.% CaCl{sub 2}+0-10 wt.% NaCl) was responsible for the deposition of a second quartz generation and dravite (magnesium-rich tourmaline) in the sandstone at the nose of the reverse basement-rooted faults. The highly calcic nature of this brine probably results from the evolution of the sodic brine through Na{r_reversible}Ca exchange in the basement. A low salinity fluid with traces of methane was heated heated in the basement rocks. It was mixed with the brines at the basis of the Kombolgie basin, during tectonic movements and hydraulic brecciation. This fluid has been rarely observed in the Canadian deposits. This study has shown many similarities between the fluid regimes of the Kombolgie and Athabasca basins. In both districts, a mixing between two Na-Ca-(Mg) chloride brines has been evidenced. Estimated temperatures and depths (about 5 km) are similar for both basins. However the brines observed at the basis of the Athabasca

  13. Streamflow input to Lake Athabasca, Canada (United States)

    Rasouli, K.; Hernández-Henríquez, M. A.; Déry, S. J.


    The Lake Athabasca drainage area in northern Canada encompasses ecologically rich and sensitive ecosystems, vast forests, glacier-clad mountains, and abundant oil reserves in the form of oil sands. The basin includes the Peace-Athabasca Delta, recognized internationally by UNESCO and the Ramsar Convention as a biologically rich inland delta and wetland that are now under increasing pressure from multiple stressors. In this study, streamflow variability and trends for rivers feeding Lake Athabasca are investigated over the last half century. Hydrological regimes and trends are established using a robust regime shift detection method and the Mann-Kendall (MK) test, respectively. Results show that the Athabasca River, which is the main contributor to the total lake inflow, experienced marked declines in recent decades impacting lake levels and its ecosystem. From 1960 to 2010 there was a significant reduction in lake inflow and a significant recession in the Lake Athabasca level. Our trend analysis corroborates a previous study using proxy data obtained from nearby sediment cores suggesting that the lake level may drop 2 to 3 m by 2100. The lake recession may threaten the flora and fauna of the Athabasca Lake basin and negatively impact the ecological cycle of an inland freshwater delta and wetland of global importance.

  14. Streamflow input to Lake Athabasca, Canada

    Directory of Open Access Journals (Sweden)

    K. Rasouli


    Full Text Available The Lake Athabasca drainage area in northern Canada encompasses ecologically rich and sensitive ecosystems, vast forests, glacier-clad mountains, and abundant oil reserves in the form of oil sands. The basin includes the Peace–Athabasca Delta, recognized internationally by UNESCO and the Ramsar Convention as a biologically rich inland delta and wetland that are now under increasing pressure from multiple stressors. In this study, streamflow variability and trends for rivers feeding Lake Athabasca are investigated over the last half century. Hydrological regimes and trends are established using a robust regime shift detection method and the Mann–Kendall (MK test, respectively. Results show that the Athabasca River, which is the main contributor to the total lake inflow, experienced marked declines in recent decades impacting lake levels and its ecosystem. From 1960 to 2010 there was a significant reduction in lake inflow and a significant recession in the Lake Athabasca level. Our trend analysis corroborates a previous study using proxy data obtained from nearby sediment cores suggesting that the lake level may drop 2 to 3 m by 2100. The lake recession may threaten the flora and fauna of the Athabasca Lake basin and negatively impact the ecological cycle of an inland freshwater delta and wetland of global importance.

  15. Mapping lithological heterogeneity in Athabasca oil sand reservoirs using surface seismic data

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Y.; Chopra, S. [Arcis Corp., Calgary, AB (Canada)


    The distribution of bitumen in the McMurray formation in the Athabasca oil sands varies due to the high degree of facies heterogeneity throughout the deposit, making it difficult to interpret geology and estimate the bitumen distribution. Good quality seismic data has good lateral and vertical coverage and helps understand oil sands reservoir heterogeneity. The relationships between reservoir lithology and rock physics parameters need to be determined, especially those that can be derived from seismic data, in order to honour the advantage of seismic data in mapping reservoir heterogeneity for the Athabasca oil sands. A practical work flow was presented along with real examples for extracting lithology-sensitive rock physics parameters from surface seismic data for characterization of lithological heterogeneity of Athabasca oilsands reservoirs in the McMurray formation. Improvement in terms of reliable 3-parameter AVO inversion was the key step in the workflow. A case history demonstrated that the method helps understand the lithological heterogeneity of Athabasca oil sand reservoirs. The derived results from the case study calibrated well with the available log curves and a blind well test confirmed the accuracy of the calibration. 4 refs., 6 figs.

  16. Ozonation of Canadian Athabasca asphaltene (United States)

    Cha, Zhixiong

    Application of ozonation in the petrochemical industry for heavy hydrocarbon upgrading has not been sufficiently explored. Among heavy hydrocarbons, asphaltenes are the heaviest and the most difficult fractions for analysis and treatment. Therefore, ozonation of asphaltenes presents an interesting application in the petrochemical industry. Commercial application of ozonation in the petrochemical industry has three obstacles: availability of an ozone-resistant and environmentally friendly solvent, the precipitation of ozonation intermediates during reaction, and recovery of the solvent and separation of the ozonation products. Preliminary ozonation of Athabasca oil sands asphaltene in nonparticipating solvents encountered serious precipitation of the ozonation intermediates. The precipitated intermediates could be polymeric ozonides and intermolecular ozonides or polymeric peroxides. Because the inhomogeneous reaction medium caused low ozone efficiency, various participating solvents such as methanol and acetic acid were added to form more soluble hydroperoxides. The mass balance results showed that on average, one asphaltene molecule reacted with 12 ozone molecules through the electrophilic reaction and the subsequent decomposition of ozonation intermediates generated acetone extractable products. GC/MS analysis of these compounds indicated that the free radical reactions could be important for generation of volatile products. The extensively ozonated asphaltene in the presence of participating solvents were refluxed with methanol to generate more volatile products. GC/MS analysis of the methanol-esterified ozonation products indicated that most volatile products were aliphatic carboxylic acid esters generated through cleavage of substituents. Reaction kinetics study showed that asphaltene ozonation was initially a diffusion rate-controlled reaction and later developed to a chemical reaction rate-controlled reaction after depletion of the reactive aromatic sites

  17. Effects of canopy-deposition interaction on H{sup +} supply to soils in Pinus banksiana and Populus tremuloides ecosystems in the Athabasca oil sands region in Alberta, Canada

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Kangho, E-mail: [Department of Renewable Resources, 442 Earth Sciences Building, University of Alberta, Edmonton, Alberta, T6G 2E3 (Canada); Chang, Scott X., E-mail: [Department of Renewable Resources, 442 Earth Sciences Building, University of Alberta, Edmonton, Alberta, T6G 2E3 (Canada); Arshad, M.A., E-mail: [Department of Renewable Resources, 442 Earth Sciences Building, University of Alberta, Edmonton, Alberta, T6G 2E3 (Canada); Agriculture and Agri-Food Canada, Beaverlodge Research Farm, Beaverlodge, AB, T0H 0C0 (Canada)


    Soil acidification has been of concern in the oil sands region in Alberta due to increased acid deposition. Using the canopy budget model, and accounting for H{sup +} canopy leaching by organic acids, we determined sources and sinks of H{sup +} in throughfall in jack pine (Pinus banksiana) and trembling aspen (Populus tremuloides) stands in two watersheds from 2006 to 2009. In pine stands, H{sup +} deposition was greater in throughfall than in bulk precipitation while the opposite was true in aspen stands. The annual H{sup +} interception deposition was 148.8-193.8 and 49.7-70.0 mol{sub c} ha{sup -1} in pine and aspen stands, respectively; while the annual H{sup +} canopy leaching was 127.1-128.7 and 0.0-6.0 mol{sub c} ha{sup -1}, respectively. The greater H{sup +} supply in pine stands was caused by greater interception deposition of SO{sub 4}{sup 2-} and organic acids released from the pine canopy. Such findings have significant implications for establishing critical loads for various ecosystems in the oil sands region. - Highlights: > We monitored acid deposition in the oil sands region of Alberta over three years. > A modified canopy budget model was developed to evaluate H{sup +} budget as the first such attempt in western Canada. > The H{sup +} supply by organic acid leaching from jack pine canopy was a significant source of H{sup +}. > This has implications for establishing critical loads for acid deposition for watersheds in the region. - A modified canopy budget model was developed and organic acid leaching from jack pine canopies was a significant source of H{sup +} in the oil sands region of Alberta.

  18. Surface Water Elevation and Quality, Peace-Athabasca Delta, Canada, 2006-2007 (United States)

    National Aeronautics and Space Administration — ABSTRACT: The Peace-Athabasca Delta (PAD) is a large boreal wetland located in northeastern Alberta, Canada at the confluence of the Peace and Athabasca Rivers with...

  19. Water Quality and Spectral Reflectance, Peace-Athabasca Delta, Canada, 2010-2011 (United States)

    National Aeronautics and Space Administration — ABSTRACT: The Peace-Athabasca Delta (PAD) is a hydrologically complex and ecologically diverse freshwater delta formed by the confluence of the Peace, Athabasca, and...

  20. Water Quality and Spectral Reflectance, Peace-Athabasca Delta, Canada, 2010-2011 (United States)

    National Aeronautics and Space Administration — The Peace-Athabasca Delta (PAD) is a hydrologically complex and ecologically diverse freshwater delta formed by the confluence of the Peace, Athabasca, and Birch...

  1. Surface Water Elevation and Quality, Peace-Athabasca Delta, Canada, 2006-2007 (United States)

    National Aeronautics and Space Administration — The Peace-Athabasca Delta (PAD) is a large boreal wetland located in northeastern Alberta, Canada at the confluence of the Peace and Athabasca Rivers with Lake...

  2. Brine migrations in the Athabasca Basin platform, alteration and associated fluid-rock exchanges; Migrations de saumures dans le socle du bassin de l'Athabasca, alteration et echanges fluide-roche associes

    Energy Technology Data Exchange (ETDEWEB)

    Mercadier, J.; Cathelineau, M.; Richard, A.; Boiron, M.Ch.; Cuney, M. [G2R, Nancy-Universite, CNRS, CREGU, 54 - Vandoeuvre-les-Nancy (France); Milesi, J.P. [AREVA, BU Mines, Tour Areva, 92 - Paris La Defense (France)


    Uranium deposits of Athabasca Basin (Saskatchewan, Canada) are considered as the richest in the world. They result from massive percolation of basin brines in the underlying platform. The authors describe the brine movements and how structures and micro-fractures promoted this percolation until very important depths (hundreds of meters under the discordance), and their chemical modifications as they interacted with platform rocks, thus promoting the transformation of an initially sodic brine into a uranium-enriched calcic brine which is essential to the formation of discordance-type deposit

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

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


    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.

  4. Metal bioaccumulation and effects biomarkers in mussels caged in the Athabasca OS mining area (United States)

    Pilote, M.; André, C.; Turcotte, P.; Gagné, F.; Gagnon, C.


    The Athabasca oil-sand (OS) deposit area is the largest world's known stock of crude bitumen and the third-largest proven crude oil reserve. Mining activity is well known to release associated contaminants, such as metals, and causes potential risk to the environment and aquatic life. The purpose of this study aimed to determine the impacts of OS mining on water quality and mussels in the area of Fort McMurray, Northern Alberta (Canada), for 2 consecutive years which showed different river water flow and metals coefficient of distribution. Autochthonous mussels (Pyganodon grandis) were placed in cages and in-situ exposed in the Athabasca R. for 4 weeks. Thereafter, metals and inorganic elements, including rare earth elements, were analyzed in water, and mussel gills and digestive glands to evaluate bioaccumulation, bioconcentration factor (BCF) and determine the resulting effects by measuring biomarkers of stress. This study clearly shows high bioaccumulation of Be (2012), V, Ni and Pb (2013) in mussel digestive glands in the Steepbank R. which flows directly of OS mining area than at the reference site, while Al, V, Cr, Co, Ni, Mo (2012) and Ni (2013) were significantly higher in mussel gills which shows different pathways of exposure for V and Ni. Metals exposure consequently impacted metallothionein and lipid peroxidation (oxidative tissues damage) in mussel. These results confirm that some metals and inorganic elements are bioavailable in mussel tissues, which was associated to metal detoxification and oxidative stress in mussels located downstream OS mining area.

  5. Online Planetary Science Courses at Athabasca University (United States)

    Connors, Martin; Munyikwa, Ken; Bredeson, Christy


    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.

  6. Assessment of regional acidifying pollutants in the Athabasca oil sands area under different emission scenarios (United States)

    Cho, Sunny; Vijayaraghavan, Krish; Spink, David; Jung, Jaegun; Morris, Ralph; Pauls, Ron


    Acid deposition is a potential environmental impact of oil sands development in the Athabasca Oil Sands Region (AOSR) in Northeastern Alberta. An acid deposition management framework has been established to manage this issue. This framework includes an acid deposition modelling and time-to-effect impact assessment component that was recently implemented for four acidifying emissions cases using the Community Multi-scale Air Quality (CMAQ) model. Predicted gross Potential Acid Input (PAI) deposition in the AOSR increases from the historical to existing case with further increases predicted in two future cases due to the projected increase in NOx emissions. On average the total predicted PAI deposition in the AOSR is approximately 40% sulphur deposition and 60% nitrogen deposition. Sulphur deposition decreases by 7% from the historical to existing cases due to the reductions in SO2 emissions that have occurred in the AOSR but increases by 5% from the existing to future case 1 and by 8% from existing to future case 2 even though continued AOSR SO2 emission decreases were modelled. This is likely the result of the deposition reduction associated with a single large reduction in SO2 emissions from one facility's main stack being offset elsewhere in the AOSR by deposition increases due to small increases in SO2 emissions from several in situ sources with shorter stacks. Average nitrogen deposition over the AOSR increases by 10% from the historical to existing case and then further increases by 10.6% from the existing case to future case 1 and by 12.3% from the existing case to future case 2. The increasing relevance of NOx emissions over SO2 emissions in the AOSR suggests that a robust treatment of nitrogen chemistry such as in CMAQ is required for conducting deposition assessments in the region. The modelling results provide information that can be used to inform oil sands emission management priorities in the context of acid deposition and nitrogen eutrophication

  7. Sulfur Biogeochemistry of Athabasca Oilsands Composite Tailings (United States)

    Warren, L. A.; Kendra, K. E.


    Oil sands tailings are important, globally relevant, S reservoirs, known to contain active and diverse microbial communities. As evidenced by increasing S emissions from the oil sands, active biogeochemical S cycling within composite tailings (CT, a mixture of tailings, post-processed sand and gypsum, used for dry reclamation), is likely; however the S biogeochemistry of these residues has not been investigated to date. With surface mining of Alberta's oil sands spanning over 142,000 square km and accelerated production, these tailings-based landscapes will become increasingly prevalent with the potential for significant environmental impacts. The objectives here, were thus to characterize depth dependent S biogeochemistry of a 40 meter CT deposit (Fort McMurray, AB, CANADA). Drill samples were collected in December of 2012 from 5 depths spanning 36 m in the CT deposit, for geochemical, metagenomic and functional enrichment analyses. Results establish widespread microbial S biogeochemical cycling within the CT deposit. Porewater H2S was detected extensively throughout the deposit with background levels ranging from 14-23 μM and a concentrated pocket of 300 μM occurring at depth. Porewater Fe(II) (1-40 μM) was detected only within surficial depth samples. Current Fe(II) concentrations are not sufficient to sequester the levels of H2S generated by CT, indicating CT may become a net source of S emissions, as generated H2S at depth migrates to the surface, in untreated CT deposits. Metagenomic (454 pyrosequencing) characterization revealed highly diverse CT microbial communities, with 21 different phyla encountered overall and 1/3 of these presenting as candidate divisions. The cultivation independent identification of several known IRB and sulphate (SRB) reducing bacteria within these communities was consistent with observed positive growth in IRB and SRB functional metabolic enrichments. Furthermore, two depth dependent structurally distinct communities emerged: a

  8. An assessment of nitrogen saturation in Pinus banksiana plots in the Athabasca Oil Sands Region, Alberta

    Directory of Open Access Journals (Sweden)

    Shaun A. WATMOUGH


    Full Text Available During the past 15 years, there has been a dramatic increase in the amount of reactive nitrogen (N in the atmosphere, leading to concerns that chronic elevated N deposition may result in negative effects on natural ecosystems. This study examines the response of jack pine (Pinus banksiana plots to N air concentrations within the Athabasca Oil Sands Region (AOSR in northern Alberta, which has experienced elevated N emissions since the 1990s. Air concentrations of nitrogen dioxide (NO2, ammonia, and nitric acid at the study plots are generally low although NO2 is strongly correlated with sulphur dioxide indicating an exposure gradient associated with industrial emissions. Nitrogen concentrations in P. banksiana foliage and two lichen indicator species (Hypogymnia physodes and Evernia mesomorpha were significantly correlated with annual NO2 exposure. Relationships between NO2 (or N exposure and other aspects of N cycling were less evident. Nitrogen content and carbon to nitrogen ratio in the forest floor and soil or potential net N mineralization rates were not correlated with N exposure. Nitrification was negligible suggesting efficient ecosystem immobilization of current N deposition. Based on the response of foliage to N exposure, sites closest to industrial activity appear to be in the early stages of N saturation.

  9. Has Alberta oil sands development increased far-field delivery of airborne contaminants to the Peace-Athabasca Delta? (United States)

    Wiklund, Johan A; Hall, Roland I; Wolfe, Brent B; Edwards, Thomas W D; Farwell, Andrea J; Dixon, D George


    Identifying potential regional contamination by Alberta oil sands industrial emissions on sensitive ecosystems like the Peace-Athabasca Delta, ~200 km to the north, requires knowledge of historical contaminant levels and trends. Here we provide some of these critically-needed data, based on analysis of metals in a sediment core from an upland precipitation-fed lake in the delta. The lake is well-situated to record the anthropogenic history of airborne contaminant deposition for this region. Sediment records of metals of concern (Pb, Sb, As, Hg) reflect early to mid-20th century increases in North American industrial emissions, followed by reduced emissions due to improved industrial practices after 1950-70. Notably, Pb, Sb, As and Hg have declined since the onset of Alberta oil sands production, belying concerns that this activity has enhanced far-field atmospheric delivery of these contaminants to the delta. Copyright © 2012 Elsevier B.V. All rights reserved.

  10. Metal bioaccumulation and biomarkers of effects in caged mussels exposed in the Athabasca oil sands area. (United States)

    Pilote, M; André, C; Turcotte, P; Gagné, F; Gagnon, C


    The Athabasca oil sands deposit is the world's largest known reservoir of crude bitumen and the third-largest proven crude oil reserve. Mining activity is known to release contaminants, including metals, and to potentially impact the aquatic environment. The purpose of this study was to determine the impacts of oil sands mining on water quality and metal bioaccumulation in mussels from the Fort McMurray area in northern Alberta, Canada. The study presents two consecutive years of contrasting mussel exposure conditions (low and high flows). Native freshwater mussels (Pyganodon grandis) were placed in cages and exposed in situ in the Athabasca River for four weeks. Metals and inorganic elements were then analyzed in water and in mussel gills and digestive glands to evaluate bioaccumulation, estimate the bioconcentration factor (BCF), and determine the effects of exposure by measuring stress biomarkers. This study shows a potential environmental risk to aquatic life from metal exposure associated with oil sands development along with the release of wastewater from a municipal treatment plant nearby. Increased bioaccumulation of Be, V, Ni and Pb was observed in mussel digestive glands in the Steepbank River, which flows directly through the oil sands mining area. Increased bioaccumulation of Al, V, Cr, Co, Ni, Mo and Ni was also observed in mussel gills from the Steepbank River. These metals are naturally present in oil sands and generally concentrate and increase with the extraction process. The results also showed different pathways of exposure (particulate or dissolved forms) for V and Ni resulting from different river water flows, distribution coefficient (Kd) and BCF. Increasing metal exposure downstream of the oil sands mining area had an impact on metallothionein and lipid peroxidation in mussels, posing a potential environmental risk to aquatic life. These results confirm the bioavailability of some metals in mussel tissues associated with detoxification of

  11. Bitumen content estimation of Athabasca oil sand from broad band infrared reflectance spectra

    Energy Technology Data Exchange (ETDEWEB)

    Rivard, B.; Feng, J. [Alberta Univ., Edmonton, AB (Canada). Dept. of Earth and Atmospheric Sciences, Earth Observation Systems Laboratory; Lyder, D. [Alberta Environment, Edmonton, AB (Canada); Gallie, A. [Laurentian Univ., Sudbury, ON (Canada). Dept. of Earth Sciences; Cloutis, E. [Winnipeg Univ., MB (Canada). Dept. of Geography; Dougan, P.; Gonzalez, S. [Syncrude Canada Ltd, Edmonton, AB (Canada); Cox, D. [Suncor Energy Inc., Fort McMurray, AB (Canada); Lipsett, M.G. [Alberta Univ., Edmonton, AB (Canada). Dept. of Mechanical Engineering


    Oil sand deposits are not homogeneous. The ore has a large variability in clay, bitumen and fines, which impact bitumen recovery. This paper reported on a study in which a linear model was developed to estimate total bitumen content (TBC) with good accuracy and independent of mine location. The purpose of the study was to enable oil sands mining operators to estimate TBC in real time. Modelling of the TBC in the Athabasca oil sands of western Canada was undertaken on the basis of hyperspectral reflectance spectra. A variety of bitumen, water, and clay mineral spectral features were used to develop broad-band TBC predictive models, with less than 1.5 percent error with respect to laboratory methods of bitumen assay. Simple broad band models, based upon previously identified Gaussian features or wavelet features, provided an incremental improvement over the two-band ratio model presently used by industry. This paper also presented a newly developed and improved two-band model which combines the same two bands, normalized to their mean. The influence of water, clay, and textural variation on selected bitumen features was addressed by a wavelet-based, broad-band model comprised of indices and five bands, where the bands were normalized to the mean of the bands. The most robust estimator of TBC appeared to be the five-band model which can be used at different sites within a mine as well as in different mines without additional tuning or calibration. 17 refs., 4 tabs., 8 figs.

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

    Directory of Open Access Journals (Sweden)

    Keith M. SOMERS


    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.

  13. Legacy of a half century of Athabasca oil sands development recorded by lake ecosystems. (United States)

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


    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.

  14. Alberta's economic development of the Athabasca oil sands (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

  15. Cover systems in the Athabasca oil sands : a summary of the Green Bullet and ten years of reclamation research at Syncrude Canada Ltd.

    Energy Technology Data Exchange (ETDEWEB)

    O' Kane, M. [O' Kane Consultants Inc., Calgary, AB (Canada)


    This PowerPoint presentation discussed the use of a dry cover system over oil sand tailings as land reclamation strategy. Dry covers can range from a single layer of earthen material to several layers of different material types, including native soils, non-reactive tailings or waste rock, geosynthetic materials, and oxygen consuming organic materials. The 3 prototype covers used in the Athabasca deposit in northern Alberta include peat, glacial till and sedge-sphagnum open bog (SSOB). The hydraulic role of the covers was described. This presentation also described how the physical reclamation works, with particular reference to how the area is contoured to ensure proper drainage. Soil and vegetation assessments are undertaken to ensure the reclamation amendments are achieving the goals of the reclamation plan. tabs., figs.

  16. Origin and composition of mineralizing fluids in the Athabasca Basin, Canada; Origine et composition des fluides mineralisateurs dans le Bassin de l'Athabasca, Canada

    Energy Technology Data Exchange (ETDEWEB)

    Richard, A.; Cathelineau, M.; Boiron, M.Ch.; Cuney, M.; Mercadier, J. [G2R, Nancy-Universite, CNRS, CREGU, 54 - Vandoeuvre-les-Nancy (France); Milesi, J.P. [AREVA, BU Mines, Tour Areva, 92 - Paris La Defense (France)


    The authors report studies aimed at understanding mechanisms of concentration of uranium in the geological environment of the Athabasca Basin (Saskatchewan, Canada). They describe how two brines, a sodic one and a calcic one, circulated and mixed together while carrying uranium with exceptional and very heterogeneous concentrations. They show that these brines have a common origin and are formed by sea water evaporation, that the calcic brine formed itself by interaction between the sodic brine and platform rocks, and that the interactions of brines with platform rocks and minerals, water radiolysis, and bitumen synthesis have controlled the isotopic content in oxygen, hydrogen and carbon of these brines

  17. Limited role for thermal erosion by turbulent lava in proximal Athabasca Valles, Mars (United States)

    Cataldo, Vincenzo; Williams, David A.; Dundas, Colin M.; Kestay, Laszlo P.


    The Athabasca Valles flood lava is among the most recent (Mars and was probably emplaced turbulently. The Williams et al. (2005) model of thermal erosion by lava has been applied to what we term “proximal Athabasca,” the 75 km long upstream portion of Athabasca Valles. For emplacement volumes of 5000 and 7500 km3and average flow thicknesses of 20 and 30 m, the duration of the eruption varies between ~11 and ~37 days. The erosion of the lava flow substrate is investigated for three eruption temperatures (1270°C, 1260°C, and 1250°C), and volatile contents equivalent to 0–65 vol % bubbles. The largest erosion depths of ~3.8–7.5 m are at the lava source, for 20 m thick and bubble-free flows that erupted at their liquidus temperature (1270°C). A substrate containing 25 vol % ice leads to maximum erosion. A lava temperature 20°C below liquidus reduces erosion depths by a factor of ~2.2. If flow viscosity increases with increasing bubble content in the lava, the presence of 30–50 vol % bubbles leads to erosion depths lower than those relative to bubble-free lava by a factor of ~2.4. The presence of 25 vol % ice in the substrate increases erosion depths by a factor of 1.3. Nevertheless, modeled erosion depths, consistent with the emplacement volume and flow duration constraints, are far less than the depth of the channel (~35–100 m). We conclude that thermal erosion does not appear to have had a major role in excavating Athabasca Valles.

  18. Aqueous dune-like bedforms in Athabasca Valles and neighbouring locations utilized in palaeoflood reconstruction (United States)

    Durrant, L.; Balme, M. R.; Carling, P. A.; Grindrod, P. M.


    Putative fluvial dunes have been identified within the Athabasca Valles and associated network of channels on Mars. Previous published work identified and measured bedforms in Athabasca Valles using photoclinometry methods on 2-3 m/pixel resolution Mars Orbiter Camera Narrow Angle images, and argued that these were created by an aqueous megaflood that occurred between 2 and 8 million years ago. This event is likely to have occurred due to geological activity associated with the Cerberus Fossae fracture system at the source of Athabasca Vallis. The present study has used higher resolution, 25 cm/pixel images from the Mars Reconnaissance Orbiter HiRISE camera, as well as stereo-derived digital terrain models and GIS software, to re-measure and evaluate these bedforms together with data from newly discovered neighbouring fields of bedforms. The analysis indicates that the bedforms are aqueous dunes, in that they occur in channel locations where dunes would be expected to be preserved and moreover they have geometries very similar to megaflood dunes on Earth. Dune geometries are used to estimate megaflood discharge rates, including uncertainty, which results support previous flood estimates that indicate that a flood with a discharge of ∼2 × 106m3s-1 created these bedforms.

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

    Sauchyn, David J; St-Jacques, Jeannine-Marie; Luckman, Brian H


    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 (i) a generalized least-squares (GLS) regression analysis of the trend and variability in gauged flow and (ii) a 900-y 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.

  20. Sources of particulate matter components in the Athabasca oil sands region: investigation through a comparison of trace element measurement methodologies (United States)

    Phillips-Smith, Catherine; Jeong, Cheol-Heon; Healy, Robert M.; Dabek-Zlotorzynska, Ewa; Celo, Valbona; Brook, Jeffrey R.; Evans, Greg


    The province of Alberta, Canada, is home to three oil sands regions which, combined, contain the third largest deposit of oil in the world. Of these, the Athabasca oil sands region is the largest. As part of Environment and Climate Change Canada's program in support of the Joint Canada-Alberta Implementation Plan for Oil Sands Monitoring program, concentrations of trace elements in PM2. 5 (particulate matter smaller than 2.5 µm in diameter) were measured through two campaigns that involved different methodologies: a long-term filter campaign and a short-term intensive campaign. In the long-term campaign, 24 h filter samples were collected once every 6 days over a 2-year period (December 2010-November 2012) at three air monitoring stations in the regional municipality of Wood Buffalo. For the intensive campaign (August 2013), hourly measurements were made with an online instrument at one air monitoring station; daily filter samples were also collected. The hourly and 24 h filter data were analyzed individually using positive matrix factorization. Seven emission sources of PM2. 5 trace elements were thereby identified: two types of upgrader emissions, soil, haul road dust, biomass burning, and two sources of mixed origin. The upgrader emissions, soil, and haul road dust sources were identified through both the methodologies and both methodologies identified a mixed source, but these exhibited more differences than similarities. The second upgrader emissions and biomass burning sources were only resolved by the hourly and filter methodologies, respectively. The similarity of the receptor modeling results from the two methodologies provided reassurance as to the identity of the sources. Overall, much of the PM2. 5-related trace elements were found to be anthropogenic, or at least to be aerosolized through anthropogenic activities. These emissions may in part explain the previously reported higher levels of trace elements in snow, water, and biota samples collected

  1. Overcoming the geotechnical challenges of drift development at the unconformity of the Athabasca Basin

    Energy Technology Data Exchange (ETDEWEB)

    Yameogo, S.T.; Hatley, J., E-mail: [Cameco Corp., McArthur River Operation, Saskatoon, SK (Canada)


    Rock mechanics literature has documented the challenges, failures and successes of tunnelling through weak rocks. Cases usually deal with low RMR rock masses or high stresses in a fractured zone. With the combination of 5 MPa water pressure, 14 RMR ground with clay infillings and ground freeze walls, the case of the 510-8225N development drift at McArthur River is certainly much more challenging, especially when high grade uranium production is at stake. The article explains the excavation and the ground control techniques that were used to overcome the challenges of development at the Unconformity in the Athabasca Basin. (author)

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

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


    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. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

  3. The maximum size of inflated flood lavas: implications for the origin and evolution of Athabasca Valles, Mars (United States)

    Sori, M. M.; Hamilton, C. W.


    We constrain the maximum size that an inflating, cooling-limited basalt flow can obtain using numerical models. We find that the Athabasca Valles flood lava on Mars is too large to represent a single, pāhoehoe-like inflated flow. Our work can be used to characterize putative lava flows throughout the solar system's terrestrial bodies.

  4. Spatial and temporal distribution of ambient nitric acid and ammonia in the Athabasca Oil Sands Region, Alberta (United States)

    A. Bytnerowicz; W. Fraczek; S. Schilling; D. Alexander


    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...

  5. Microbial processes in the Athabasca Oil Sands and their potential applications in microbial enhanced oil recovery. (United States)

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


    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.

  6. Recent Warming, Rather than Industrial Emissions of Bioavailable Nutrients, Is the Dominant Driver of Lake Primary Production Shifts across the Athabasca Oil Sands Region. (United States)

    Summers, Jamie C; Kurek, Joshua; Kirk, Jane L; Muir, Derek C G; Wang, Xiaowa; Wiklund, Johan A; Cooke, Colin A; Evans, Marlene S; Smol, John P


    Freshwaters in the Athabasca Oil Sands Region (AOSR) are vulnerable to the atmospheric emissions and land disturbances caused by the local oil sands industry; however, they are also affected by climate change. Recent observations of increases in aquatic primary production near the main development area have prompted questions about the principal drivers of these limnological changes. Is the enhanced primary production due to deposition of nutrients (nitrogen and phosphorus) from local industry or from recent climatic changes? Here, we use downcore, spectrally-inferred chlorophyll-a (VRS-chla) profiles (including diagenetic products) from 23 limnologically-diverse lakes with undisturbed catchments to characterize the pattern of primary production increases in the AOSR. Our aim is to better understand the relative roles of the local oil sands industry versus climate change in driving aquatic primary production trends. Nutrient deposition maps, generated using geostatistical interpolations of spring-time snowpack measurements from a grid pattern across the AOSR, demonstrate patterns of elevated total phosphorus, total nitrogen, and bioavailable nitrogen deposition around the main area of industrial activity. However, this pattern is not observed for bioavailable phosphorus. Our paleolimnological findings demonstrate consistently greater VRS-chla concentrations compared to pre-oil sands development levels, regardless of morphological and limnological characteristics, landscape position, bioavailable nutrient deposition, and dibenzothiophene (DBT)-inferred industrial impacts. Furthermore, breakpoint analyses on VRS-chla concentrations across a gradient of DBT-inferred industrial impact show limited evidence of a contemporaneous change among lakes. Despite the contribution of bioavailable nitrogen to the landscape from industrial activities, we find no consistency in the spatial pattern and timing of VRS-chla shifts with an industrial fertilizing signal. Instead

  7. Recent Warming, Rather than Industrial Emissions of Bioavailable Nutrients, Is the Dominant Driver of Lake Primary Production Shifts across the Athabasca Oil Sands Region.

    Directory of Open Access Journals (Sweden)

    Jamie C Summers

    Full Text Available Freshwaters in the Athabasca Oil Sands Region (AOSR are vulnerable to the atmospheric emissions and land disturbances caused by the local oil sands industry; however, they are also affected by climate change. Recent observations of increases in aquatic primary production near the main development area have prompted questions about the principal drivers of these limnological changes. Is the enhanced primary production due to deposition of nutrients (nitrogen and phosphorus from local industry or from recent climatic changes? Here, we use downcore, spectrally-inferred chlorophyll-a (VRS-chla profiles (including diagenetic products from 23 limnologically-diverse lakes with undisturbed catchments to characterize the pattern of primary production increases in the AOSR. Our aim is to better understand the relative roles of the local oil sands industry versus climate change in driving aquatic primary production trends. Nutrient deposition maps, generated using geostatistical interpolations of spring-time snowpack measurements from a grid pattern across the AOSR, demonstrate patterns of elevated total phosphorus, total nitrogen, and bioavailable nitrogen deposition around the main area of industrial activity. However, this pattern is not observed for bioavailable phosphorus. Our paleolimnological findings demonstrate consistently greater VRS-chla concentrations compared to pre-oil sands development levels, regardless of morphological and limnological characteristics, landscape position, bioavailable nutrient deposition, and dibenzothiophene (DBT-inferred industrial impacts. Furthermore, breakpoint analyses on VRS-chla concentrations across a gradient of DBT-inferred industrial impact show limited evidence of a contemporaneous change among lakes. Despite the contribution of bioavailable nitrogen to the landscape from industrial activities, we find no consistency in the spatial pattern and timing of VRS-chla shifts with an industrial fertilizing signal

  8. Reactivity of Athabasca residue and of its SARA fractions during residue hydroconversion

    Energy Technology Data Exchange (ETDEWEB)

    Verstraete, J.; Danial-Fortain, P.; Gauthier, T.; Merdrignac, I. [IFP-Lyon, Vermaison (France); Budzinski, H. [Bordeaux Univ. (France). ISM-LPTC, UMR CNRS


    Residue conversion processes are becoming increasingly important because of the declining market for residual fuel oil and a greater demand for middle distillates. Ebullated-bed hydroconversion is a commercially proven technology for converting heavy feedstocks with high amounts of impurities. The process enables the conversion of atmospheric or vacuum residues at temperatures up to 440 degrees C, and at liquid hourly space velocity (LHSV) conditions in the range of 0.15 to 0.5 per hour. A 540 degrees C conversion of up to 80 weight per cent can be achieved under these conditions. This paper reported on a research study conducted at IFP Lyon in which the residue hydroconversion in a large-scale ebullated bed bench unit was investigated to determine the impact of operating conditions and feed properties on yield and product qualities. Hydrogen was added to the feed in the bench units to keep a high hydrogen partial pressure and favour the catalytic hydroconversion reactions. In a typical test, the reactor was fed with 50 g of feedstock and 0.45 g of crushed equilibrium industrial NiMo catalyst, pressurized hydrogen and quickly heated at the reaction temperature. This paper also discussed the conversion of Athabasca bitumen residue in the large-scale pilot plant and also in the small scale batch reactor. The effect of operating temperature and space velocity was examined. The reactivity of the saturates, aromatics, resins and asphaltenes (SARA) fractions of the bitumen was studied separately in order to better understand the conversion mechanisms and reactivities. The Athabasca bitumen feed and SARA fractions were also analyzed in terms of standard petroleum analysis, SARA fractionation, elemental analysis, size exclusion chromatography (SEC) and 13C NMR. Hydroconversion experiments were conducted in the batch unit at different reaction temperatures and reaction times. A comparison of small-scale batch results with those obtained with the continuous large-scale bench

  9. Beyond Naphthenic Acids: Environmental Screening of Water from Natural Sources and the Athabasca Oil Sands Industry Using Atmospheric Pressure Photoionization Fourier Transform Ion Cyclotron Resonance Mass Spectrometry. (United States)

    Barrow, Mark P; Peru, Kerry M; Fahlman, Brian; Hewitt, L Mark; Frank, Richard A; Headley, John V


    There is a growing need for environmental screening of natural waters in the Athabasca region of Alberta, Canada, particularly in the differentiation between anthropogenic and naturally-derived organic compounds associated with weathered bitumen deposits. Previous research has focused primarily upon characterization of naphthenic acids in water samples by negative-ion electrospray ionization methods. Atmospheric pressure photoionization is a much less widely used ionization method, but one that affords the possibility of observing low polarity compounds that cannot be readily observed by electrospray ionization. This study describes the first usage of atmospheric pressure photoionization Fourier transform ion cyclotron resonance mass spectrometry (in both positive-ion and negative-ion modes) to characterize and compare extracts of oil sands process water, river water, and groundwater samples from areas associated with oil sands mining activities. When comparing mass spectra previously obtained by electrospray ionization and data acquired by atmospheric pressure photoionization, there can be a doubling of the number of components detected. In addition to polar compounds that have previously been observed, low-polarity, sulfur-containing compounds and hydrocarbons that do not incorporate a heteroatom were detected. These latter components, which are not amenable to electrospray ionization, have potential for screening efforts within monitoring programs of the oil sands.

  10. Century-long source apportionment of PAHs in Athabasca oil sands region lakes using diagnostic ratios and compound-specific carbon isotope signatures. (United States)

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


    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.

  11. Parasitological Analysis and Gill Histopathology of Pearl Dace (Semotilus Margarita) and Brook Stickleback (Culaea Inconstans) Collected from the Athabasca Oil Sands Area (Canada). (United States)

    Raine, J C; Pietrock, M; Willner, K; Chung, K; Turcotte, D; Parrott, J L


    Pearl dace (Semotilus margarita) and brook stickleback (Culaea inconstans) were collected from tributaries of the Athabasca River (Alberta, Canada), upstream (reference site) and downstream of oil sands deposits where fish were expected to be exposed to naturally occurring oil sands constituents. The objective was to determine if fish collected from these sites exhibited differences in the prevalence or intensity of infection by parasites or in gill histology. Dace did not display significant differences in these parameters. Alternately, upstream stickleback were predominantly infected by complex life history parasites, while downstream fish were primarily infected by parasites with simpler life histories. Moreover, downstream stickleback exhibited significantly more clubbing and aneurysms in secondary gill lamellae relative to upstream fish. This suggested a difference in habitat quality between upstream and downstream sites. However, based on basic body condition parameters of the fish, it would appear that any impacts upon the health of the fish due to the presence of naturally occurring oil sands associated chemical constituents would have been minor.

  12. 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


    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Ciborowski, J. [Windsor Univ., ON (Canada); Dixon, G. [Waterloo Univ., ON (Canada); Foote, L. [Alberta Univ., Edmonton, AB (Canada); Liber, K.; Smits, J. [Saskatchewan Univ., Regina, SK (Canada)


    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.

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

    Directory of Open Access Journals (Sweden)

    Alan Davis


    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.

  15. Proceedings of the 7. annual Athabasca oil sands conference : oil sands trade show and conference

    Energy Technology Data Exchange (ETDEWEB)



    The Athabasca Oil Sands Projects are considered a major source energy supply for North America, which means increased commitments from producing companies to improve environmental impact and enhance the technology used for extraction and refining. This annual conference, which was hosted by the world's leading group of experts in the unconventional oil industry, provided a venue to network, do business and discover new strategies and innovations for the industry. The presentations highlighted thermal recovery methods, transportation infrastructure, and government policies designed to ensure project success. The four sessions of the conference were entitled: the oil sands landscape, technology advances; project updates; and, research and development. The conference featured 12 presentations, of which 4 have been catalogued separately for inclusion in this database. tabs., figs.

  16. Proceedings of the 8. annual Athabasca oil sands conference : oil sands trade show and conference

    Energy Technology Data Exchange (ETDEWEB)



    This conference featured the latest information on challenges, strategies, technologies, and labour issues facing the heavy oil industry. It was hosted by the world's leading group of experts in the unconventional oil industry and offered prime networking opportunities in an interactive setting for over 500 delegates from around the world. The Athabasca Oil Sands Projects are considered a major source energy supply for North America, which means increased commitments from producing companies to improve environmental impact and enhance the technology used for extraction and refining. Advances in thermal recovery operations, notably steam assisted gravity drainage (SAGD), were highlighted along with new pumping technologies and tailings management issues. The sessions of the conference were entitled: project updates; pumping for the future; and, operational concerns. The conference featured 16 presentations, of which 5 have been catalogued separately for inclusion in this database. tabs., figs.

  17. Sources of particulate matter components in the Athabasca oil sands region: investigation through a comparison of trace element measurement methodologies

    Directory of Open Access Journals (Sweden)

    C. Phillips-Smith


    Full Text Available The province of Alberta, Canada, is home to three oil sands regions which, combined, contain the third largest deposit of oil in the world. Of these, the Athabasca oil sands region is the largest. As part of Environment and Climate Change Canada's program in support of the Joint Canada-Alberta Implementation Plan for Oil Sands Monitoring program, concentrations of trace elements in PM2. 5 (particulate matter smaller than 2.5 µm in diameter were measured through two campaigns that involved different methodologies: a long-term filter campaign and a short-term intensive campaign. In the long-term campaign, 24 h filter samples were collected once every 6 days over a 2-year period (December 2010–November 2012 at three air monitoring stations in the regional municipality of Wood Buffalo. For the intensive campaign (August 2013, hourly measurements were made with an online instrument at one air monitoring station; daily filter samples were also collected. The hourly and 24 h filter data were analyzed individually using positive matrix factorization. Seven emission sources of PM2. 5 trace elements were thereby identified: two types of upgrader emissions, soil, haul road dust, biomass burning, and two sources of mixed origin. The upgrader emissions, soil, and haul road dust sources were identified through both the methodologies and both methodologies identified a mixed source, but these exhibited more differences than similarities. The second upgrader emissions and biomass burning sources were only resolved by the hourly and filter methodologies, respectively. The similarity of the receptor modeling results from the two methodologies provided reassurance as to the identity of the sources. Overall, much of the PM2. 5-related trace elements were found to be anthropogenic, or at least to be aerosolized through anthropogenic activities. These emissions may in part explain the previously reported higher levels of trace elements in snow

  18. An added dimension: GC atmospheric pressure chemical ionization FTICR MS and the Athabasca oil sands. (United States)

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


    The Athabasca oil sands industry, an alternative source of petroleum, uses large quantities of water during processing of the oil sands. In keeping with Canadian environmental policy, the processed water cannot be released to natural waters and is thus retained on-site in large tailings ponds. There is an increasing need for further development of analytical methods for environmental monitoring. The following details the first example of the application of gas chromatography atmospheric pressure chemical ionization Fourier transform ion cyclotron resonance mass spectrometry (GC-APCI-FTICR MS) for the study of environmental samples from the Athabasca region of Canada. APCI offers the advantages of reduced fragmentation compared to other ionization methods and is also more amenable to compounds that are inaccessible by electrospray ionization. The combination of GC with ultrahigh resolution mass spectrometry can improve the characterization of complex mixtures where components cannot be resolved by GC alone. This, in turn, affords the ability to monitor extracted ion chromatograms for components of the same nominal mass and isomers in the complex mixtures. The proof of concept work described here is based upon the characterization of one oil sands process water sample and two groundwater samples in the area of oil sands activity. Using the new method, the Ox and OxS compound classes predominated, with OxS classes being particularly relevant to the oil sands industry. The potential to resolve retention times for individual components within the complex mixture, highlighting contributions from isomers, and to characterize retention time profiles for homologous series is shown, in addition to the ability to follow profiles of double bond equivalents and carbon number for a compound class as a function of retention time. The method is shown to be well-suited for environmental forensics.

  19. Paleolimnological assessment of nutrient enrichment on diatom assemblages in a priori defined nitrogen- and phosphorus-limited lakes downwind of the Athabasca Oil Sands, Canada

    Directory of Open Access Journals (Sweden)

    Kathleen R. Laird


    Full Text Available As the industrial footprint of the Athabasca Oil Sands Region (AOSR continues to expand, concern about the potential impacts of pollutants on the surrounding terrestrial and aquatic ecosystems need to be assessed. An emerging issue is whether recent increases in lake production downwind of the development can be linked to AOSR activities, and/or whether changing climatic conditions are influencing lake nutrient status. To decipher the importance of pollutants, particularly atmospheric deposition of reactive nitrogen (Nr, and the effects of climate change as potential sources of increasing lake production, lakes from both within and outside of the nitrogen deposition zone were analyzed for historical changes in diatom assemblages. Lake sediment cores were collected from a priori defined nitrogen (N - and phosphorus (P - limited lakes within and outside the N plume associated with the AOSR. Diatom assemblages were quantified at sub-decadal resolution since ca. 1890 to compare conditions prior to oil sands expansion and regional climate warming, to the more recent conditions in each group of lakes (Reference and Impacted, N- and P-limited lakes. Analyses of changes in assemblage similarity and species turnover indicates that changes in diatom assemblages were minimal both within and across all lake groups.  Small changes in percent composition of planktonic taxa, particularly small centric taxa (Discostella and Cyclotella species and pennate taxa, such as Asterionella formosa and Fragilaria crotonensis, occurred in some of the lakes. While these changes were consistent with potential climate effects on algal growth, water column stability and other factors; the timing and direction of biotic changes were variable among sites suggesting that any apparent response to climate was lake dependent. The absence of a consistent pattern of diatom changes associated with receipt of reactive nitrogen or intrinsic nutrient-limitation status of the lake

  20. Developing the Guidelines for Reclamation to Forest Vegetation in the Athabasca Oil Sands Region

    Energy Technology Data Exchange (ETDEWEB)

    Straker, J. [Integral Ecology Group Ltd., Victoria, BC (Canada); Cumulative Environmental Management Association, Fort McMurray, AB (Canada). Reclamation Working Group, Terrestrial Subgroup; Donald, G. [Donald Functional and Applied Ecology Inc., Victoria, BC (Canada); Cumulative Environmental Management Association, Fort McMurray, AB (Canada). Reclamation Working Group, Terrestrial Subgroup


    This paper discussed the development process behind and the structure of the Guidelines for Reclamation to Forest Vegetation in the Athabasca Oil Sands Region. The advances present in the second edition, published in 2010, were described relative to the first edition, which was published in 1998. Oils sands mining companies are mandated to use the manual under the Alberta Environmental Protection and Enhancement Act. The paper provided an overview of the structure of the second edition and presented the process used to develop the second edition. It also described the planning approaches for revegetative treatments and the planning guidance of overstory and understory species selection. The methods for evaluating revegetative success were also described with particular reference to plant community composition and soil salinity indicators as examples of indicator development. The goal of the manual is to provide guidance on re-establishing the vegetation component of upland ecosystems on reclaimed landscapes and on evaluating the success of the re-establishment, assuming that the reclaimed plant communities should have species characteristic of native plant communities in the region, that the trends of vegetation community and structure development on reclaimed land should be similar to native plant communities in the region, and that the reclaimed ecosystems should have development trajectories that satisfy land-use objectives and provide resilience against natural disturbances. 15 refs., 1 tab., 1 fig.

  1. Foliage Chemistry of Pinus baksiana in the Athabasca Oil Sands Region, Alberta, Canada

    Directory of Open Access Journals (Sweden)

    Bernadette C. Proemse


    Full Text Available Industrial emissions in the Athabasca Oil Sands Region (AOSR, Alberta, Canada, have caused concerns about the effect of oil sands operations on the surrounding terrestrial environments, including jack pine (Pinus banksiana Lamb. stands. We collected jack pine needles from 19 sites in the AOSR (13–128 km from main operations for foliar chemical analyses to investigate the environmental impact on jack pine. Pine needles from three age classes, the current annual growth (CAG, 2011, one year and two year old pine needles, were collected. Samples were analyzed for total carbon (TC, nitrogen (TN, and sulfur (TS, inorganic S (SO4-S, base cations (Ca, Mg, Na, and other elements (B, Cu, Fe, Mn, P, Zn; CAG needles were also analyzed for their nitrogen and carbon isotopic compositions. Only TN, TS, Ca, B, Zn, and Fe contents showed weak but significant increases with proximity to the major oil sands operations. C and N isotopic compositions showed no trend with distance or TC and TN contents. Total S contents in CAG of pine foliage increased significantly with proximity to the main industrial operation while foliar inorganic S to organic S ratios (SO4-S/Sorg ranged consistently between 0.13 and 0.32, indicating low to moderately high S loading. Hence, this study suggests some evidence of uptake of S emissions in close proximity to anthropogenic sources, although the reported values have not reached a level of environmental concern.

  2. Moving to Open Educational Resources at Athabasca University: A Case Study

    Directory of Open Access Journals (Sweden)

    Cindy Ives


    Full Text Available Since the birth of the World Wide Web, educators have been exchanging ideas and sharing resources online. They are all aware of the turmoil in higher education created by freely available content, including some hopeful developments charted in this issue. Interest has grown steadily over the past decade in making a university-level education openly available to students around the globe who would otherwise be overlooked, and recommendations for how to do this are well documented (e.g., UNESCO, 2002; OECD, 2007. Initiatives in the United States (Thille, 2012, Canada (Stacey, 2011b, Africa (OER Africa, n.d., and the United Kingdom (JISC, 2012 are easily accessed and case studies abound (e.g., Barrett, Grover, Janowski, van Lavieren, Ojo, & Schmidt, 2009. Supporting the widespread availability of OER is a goal that Athabasca University (AU has embraced through association with the Commonwealth of Learning and by becoming a charter member of the OER University (OERu, 2011. The use of OER in AU programs has strategic local implications that go beyond the five reasons for institutions to engage in OER projects described by Hylén (2006. Recently at AU explorations have begun into the potential of using OER in course design and production.

  3. Geology of the Cluff Lake uranium deposits

    Energy Technology Data Exchange (ETDEWEB)

    Harper, C.T.


    The uranium deposits discovered by Amok (Canada) Ltd. in the Cluff Lake area of northwestern Saskatchewan occur at or near the southern edge of the uplifted basement core of the Carswell circular structure. Two types of mineralization, distinguishable by their geological and structural setting and mineral paragenesis, have been recognized. The N-Claude type is characterized by a relatively simple mineral assemblage, consisting of uraninite or pitchblende with coffinite, and is accompanied by variable amounts of graphite and organic matter, and Fe, Cu, Pb and Mo sulphides. Both N and Claude orebodies occur within quartzofeldspathic gneisses of the basement core. On the other hand, the D-type ore has a complex mineral assemblage consisting of: uraninite, pitchblende, thucholite and coffinite, along with native gold and selenium; gold tellurides, and selenides of Pb, Bi, Ni and Co; sulphides of Fe, Cu and Pb; and organic matter. The D orebody occurs within carbonaceous shales at the base of the Athabasca Formation as well as in fault zones in regolithic quartzofeldspathic gneisses above the inverted unconformity. An age of 1050 m.y., which is consistent with a period (circa to 1200 to 1000 m.y.) of widespread hydrothermal activity and uranium mineralization or reworking within and adjacent to the Athabasca Basin, has been obtained from uranium mineralization from the D orebody. Later reworking (circa 470 m.y.) of the mineralization occurred at the intersection of older mineralized shear zones with radial faults produced during meteorite impact.

  4. Impacts of sulphur and nitrogen deposition in western Canada

    Directory of Open Access Journals (Sweden)

    Patrick D. SHAW


    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. Evaluating microbial carbon sources in Athabasca oil sands tailings ponds using natural abundance stable and radiocarbon isotopes (United States)

    Ahad, J. M.; Pakdel, H.


    Natural abundance stable (δ13C) and radiocarbon (Δ14C) isotopes of phospholipid fatty acids (PLFAs) were used to evaluate the carbon sources utilized by the active microbial populations in surface sediments from Athabasca oil sands tailings ponds. The absence of algal-specific PLFAs at three of the four sites investigated, in conjunction with δ13C signatures for PLFAs that were generally within ~3‰ of that reported for oil sands bitumen (~ -30‰), indicated that the microbial communities growing on petroleum constituents were dominated by aerobic heterotrophs. The Δ14C values of PLFAs ranged from -906 to -586‰ and pointed to a significant uptake of fossil carbon (up to ~90% of microbial carbon derived from petroleum), particularly in PLFAs (e.g., cy17:0 and cy19:0) often associated with petroleum hydrocarbon degrading bacteria. The comparatively higher levels of 14C in other, less specific PLFAs (e.g., 16:0) indicated the preferential uptake of younger organic matter by the general microbial population (~50-80% of microbial carbon derived from petroleum). Since the main carbon pools in tailings sediment were essentially 'radiocarbon dead' (i.e., no detectable 14C), the principal source for this modern carbon is considered to be the Athabasca River, which provides the bulk of the water used in the bitumen extraction process. The preferential uptake of the minor amount of young and presumably more biodegradable material present in systems otherwise dominated by recalcitrant petroleum constituents has important implications for remediation strategies. On the one hand, it implies that mining-related organic contaminants could persist in the environment long after tailings pond reclamation has begun. Alternatively, it may be that the young, labile organic matter provided by the Athabasca River plays an important role in stimulating or supporting the microbial utilization of petroleum carbon in oil sands tailings ponds via co-metabolism or priming processes

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

    Energy Technology Data Exchange (ETDEWEB)

    Martin, Nancy, E-mail: [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)


    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

  7. Arsenic speciation in the lower Athabasca River watershed: A geochemical investigation of the dissolved and particulate phases. (United States)

    Donner, Mark W; Javed, Muhammad Babar; Shotyk, William; Francesconi, Kevin A; Siddique, Tariq


    Human and ecosystem health concerns for arsenic (As) in the lower Athabasca River downstream of Athabasca Bituminous Sands (ABS) mining (Alberta, Canada) prompted an investigation to determine its forms in surface and groundwater upstream and downstream of industry. Dissolved As species, together with total and particulate As, were used to evaluate the potential bioavailability of As in water as well as to decipher inputs from natural geological processes and ABS mining and upgrading activities. Water samples were collected from the river in October at 13 locations in 2014 and 19 locations in 2015, spanning up to 125 km. Additional samples were collected from groundwater, tributaries and springs. "Dissolved" (0.45 μm). In 2014, when total As concentrations were greater, a significant correlation (p  0.45 μm, suggesting that mineral material is an important source of As. Naturally saline groundwater contained low dissolved As (<2 μg L-1) and did not appear to be a significant source to the river. Arsenic in shallow groundwater near a tailings pond exceeded 50 μg L-1 predominantly as As(III) warranting further investigation. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Source apportionment of ambient fine and coarse particulate matter at the Fort McKay community site, in the Athabasca Oil Sands Region, Alberta, Canada. (United States)

    Landis, Matthew S; Patrick Pancras, J; Graney, Joseph R; White, Emily M; Edgerton, Eric S; Legge, Allan; Percy, Kevin E


    An ambient air particulate matter sampling study was conducted at the Wood Buffalo Environmental Association (WBEA) AMS-1 Fort McKay monitoring station in the Athabasca Oil Sand Region (AOSR) in Alberta, Canada from February 2010 to July 2011. Daily 24h integrated fine (PM2.5) and coarse (PM10-2.5) particulate matter was collected using a sequential dichotomous sampler. Over the duration of the study, 392 valid daily dichotomous PM2.5 and PM10-2.5 sample pairs were collected with concentrations of 6.8±12.9μgm-3 (mean±standard deviation) and 6.9±5.9μgm-3, respectively. A subset of 100 filter pairs was selected for element analysis by energy dispersive X-ray fluorescence and dynamic reaction cell inductively coupled plasma mass spectrometry. Application of the U.S. EPA positive matrix factorization (PMF) receptor model to the study data matrix resolved five PM2.5 sources explaining 96% of the mass including oil sands upgrading (32%), fugitive dust (26%), biomass combustion (25%), long-range Asian transport lead source (9%), and winter road salt (4%). An analysis of historical PM2.5 data at this site shows that the impact of smoke from wildland fires was particularly high during the summer of 2011. PMF resolved six PM10-2.5 sources explaining 99% of the mass including fugitive haul road dust (40%), fugitive oil sand (27%), a mixed source fugitive dust (16%), biomass combustion (12%), mobile source (3%), and a local copper factor (1%). Results support the conclusion of a previous epiphytic lichen biomonitor study that near-field atmospheric deposition in the AOSR is dominated by coarse fraction fugitive dust from bitumen mining and upgrading operations, and suggest that fugitive dust abatement strategies targeting the three major sources of PM10-2.5 (e.g., oil sand mining, haul roads, bulk material stockpiles) would significantly reduce near-field atmospheric deposition gradients in the AOSR and reduce ambient PM concentrations in the Fort McKay community

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

    Energy Technology Data Exchange (ETDEWEB)

    Ciborowski, J.J. [Windsor Univ., ON (Canada); Dixon, G. [Waterloo Univ., ON (Canada); Foote, L. [Alberta Univ., Edmonton, AB (Canada); Liber, K.; Smits, J.E. [Saskatchewan Univ., Regina, SK (Canada)


    The remediation and ecology of oilsands constructed wetlands was discussed with reference to a project known as the Carbon dynamics, Food web structure and Reclamation strategies in Athabasca oil sands Wetlands (CFRAW). This joint project between 7 mining partners and 5 universities documents how tailings in constructed wetlands modify maturation leading to natural conditions in a reclaimed landscape. Since wetlands are expected to make up 20-50 per cent of the final reclamation landscape of areas surface mined for oil sands in northeastern Alberta, the project focuses on how quickly wetlands amended with reclamation materials approach the conditions seen in reference wetland systems. This study provided a conceptual model of carbon pathways and budgets to evaluate how the allocation of carbon among compartments changes as newly formed wetlands mature in the boreal system. It is likely that succession and community development will accelerate if constructed wetlands are supplemented with stockpiled peat or topsoil. The bitumens and naphthenic acids found in wetlands constructed with mine tailings materials are initially toxic, but may ultimately serve as an alternate source of carbon once they degrade or are metabolized by bacteria. This study evaluated the sources, biological uptake, pathways, and movement through the food web of materials used by the biota in constructed wetlands, with particular reference to how productivity of new wetlands is maintained. Net ecosystem productivity is being monitored along with rates of organic carbon accumulation from microbial, algal, and macrophyte production, and influx of outside materials. The rates of leaf litter breakdown and microbial respiration are also being monitored to determine how constituents speed or slow food web processes of young and older wetlands. Carbon and nitrogen stable isotope measurements indicate which sources are incorporated into the food web as wetlands age, and how this influences community

  10. From evaporated seawater to uranium-mineralizing brines: Isotopic and trace element study of quartz-dolomite veins in the Athabasca system (United States)

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


    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

  11. Use of Bathymetric and LiDAR Data in Generating Digital Elevation Model over the Lower Athabasca River Watershed in Alberta, Canada

    Directory of Open Access Journals (Sweden)

    Ehsan H. Chowdhury


    Full Text Available The lower Athabasca River watershed is one of the most important regions for Alberta and elsewhere due to fact that it counts for the third largest oil reserve in the world. In order to support the oil and gas extraction, Athabasca River provides most of the required water supply. Thus, it is critical to understand the characteristics of the river and its watershed in order to develop sustainable water management strategies. Here, our main objective was to develop a digital elevation model (DEM over the lower Athabasca River watershed including the main river channel of Athabasca River (i.e., approximately 128 km from Fort McMurray to Firebag River confluence. In this study, the primary data were obtained from the Alberta Environmental Monitoring, Evaluation and Reporting Agency. Those were: (i Geoswath bathymetry at 5–10 m spatial resolution; (ii point cloud LiDAR data; and (iii river cross-section survey data. Here, we applied spatial interpolation methods like inverse distance weighting (IDW and ordinary kriging (OK to generate the bathymetric surface at 5 m × 5 m spatial resolution using the Geoswath bathymetry data points. We artificially created data gaps in 24 sections each in the range of 100 to 400 m along the river and further investigated the performance of the methods based on statistical analysis. We observed that the DEM generated using the both IDW and OK methods were quite similar, i.e., r2, relative error, and root mean square error were approximately 0.99, 0.002, and 0.104 m, respectively. We also evaluated the performance of both methods over individual sections of interest; and overall deviation was found to be within ±2.0 m while approximately 96.5% of the data fell within ±0.25 m. Finally, we combined the Geoswath-derived DEM and LiDAR-derived DEM in generating the final DEM over the lower Athabasca River watershed at 5 m × 5 m resolution.

  12. An Overview of SWOT Related Research in Canada, with a Focus on the Peace-Athabasca Delta Region (United States)

    Peters, D. L.; Baird, D. J.; Brisco, B.; Cantin, J. F.; Fiset, J. M.; Fortin, V.; Leconte, R.; Niemann, O.; Pietroniro, A.; Saint-Jean, R.; Siles, G. L.; Skelly, R.; Stiff, D.; Trudel, M.; Yang, D.


    Satellite remote sensing platforms like the Surface Water and Ocean Topography (SWOT) provide innovative opportunities to monitor surface water elevation of rivers, lakes and wetlands. For rivers, surface water slopes can be obtained and discharge estimated where gauging is of low density and/or absent, such as remote northern regions of Canada. In wetlands areas, such as deltas, high resolution surface water extent and digital elevation mapping (DEM) can be combined with surface water elevation products to assess recharge, drawdown and storage of water. The Peace-Athabasca Delta (PAD) is a deltaic ecosystem of international importance. This 6000 km2 delta complex, which formed at the confluence of the Peace, Athabasca and Birch rivers, contains >1000 lake/wetland basins with varying degrees of connectivity to the main flow system. Wetland hydroperiod is influenced by occasional ice-jam and open-water inundations that recharge the basins. Prior studies identified i) change in storage and ii) pathways of river-to-wetland floodwater connection as key knowledge gaps, limiting our ability to assess ecosystem status. Surface elevation mapping of the PAD was obtained using aerial remote sensing Light Detection and Ranging (LiDAR), plus thousands of ground based surface and bathymetric survey points tied to Global Positioning System (GPS). The elevation information was recently used to develop a high resolution DEM and a two dimensional hydraulic model (H2D2). Importantly, the surveyed areas contain >25 wetland monitoring sites where water level/depth, water quality, and aquatic ecology have been monitored for several years. The objective of this presentation is four-fold: i) Outline ongoing SWOT related research in Canada; ii) Present the surface water connectivity and storage results for the PAD complex; iii) Outline the implications of anticipated SWOT derived products in enhancing our ability to understand hydrological regimes by providing novel hydrometric data sets

  13. 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)


    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.

  14. Heterocyclic Aromatics in Petroleum Coke, Snow, Lake Sediments, and Air Samples from the Athabasca Oil Sands Region. (United States)

    Manzano, Carlos A; Marvin, Chris; Muir, Derek; Harner, Tom; Martin, Jonathan; Zhang, Yifeng


    The aromatic fractions of snow, lake sediment, and air samples collected during 2011-2014 in the Athabasca oil sands region were analyzed using two-dimensional gas chromatography following a nontargeted approach. Commonly monitored aromatics (parent and alkylated-polycyclic aromatic hydrocarbons and dibenzothiophenes) were excluded from the analysis, focusing mainly on other heterocyclic aromatics. The unknowns detected were classified into isomeric groups and tentatively identified using mass spectral libraries. Relative concentrations of heterocyclic aromatics were estimated and were found to decrease with distance from a reference site near the center of the developments and with increasing depth of sediments. The same heterocyclic aromatics identified in snow, lake sediments, and air were observed in extracts of delayed petroleum coke, with similar distributions. This suggests that petroleum coke particles are a potential source of heterocyclic aromatics to the local environment, but other oil sands sources must also be considered. Although the signals of these heterocyclic aromatics diminished with distance, some were detected at large distances (>100 km) in snow and surface lake sediments, suggesting that the impact of industry can extend >50 km. The list of heterocyclic aromatics and the mass spectral library generated in this study can be used for future source apportionment studies.

  15. Exploring the biodegradation and toxicity of naphthenic acids present in Athabasca oil sands process affected waters using simulated wetlands

    Energy Technology Data Exchange (ETDEWEB)

    Toor, N.; Liber, K. [Saskatchewan Univ., Regina, SK (Canada); MacKinnon, M. [Syncrude Canada Ltd., Edmonton, AB (Canada); Fedorak, P. [Alberta Univ., Edmonton, AB (Canada)


    Naphthenic acids (NAs) are a persistent group of dissolved organic acids found in oil sands process affected water (OSPW) from the Athabasca Oil Sands (AOS) in northern Alberta. This study investigated the feasibility of reducing the toxicity of OSPW in wetland environments, and proposed a strategy for reclamation at the AOS. Laboratory microcosms were used to mimic natural wetlands. The purpose was to determine if the toxicities of OSPWs generated by Syncrude Canada Ltd. (Syncrude) and Suncor Energy Inc. (Suncor) change with time as a result of aging and biodegradation. Experiments involved 2 types of OSPW obtained from Syncrude and Suncor. Nutrient availability (nitrogen and phosphorus enrichment) was increased for both short and long hydraulic retention times (40 and 400 days). The NAs found in the OSPW were tracked over the course of one year using Fourier Transform Infrared Spectroscopy, Gas Chromatography/Mass Spectrometry and Microtox bioassays. The objective was to determine the relationships between total NA concentrations, the degree to which different sub-groups of NAs are biodegraded and any potential reduction in OSPW toxicity.

  16. Sphagnum mosses from 21 ombrotrophic bogs in the athabasca bituminous sands region show no significant atmospheric contamination of "heavy metals". (United States)

    Shotyk, William; Belland, Rene; Duke, John; Kempter, Heike; Krachler, Michael; Noernberg, Tommy; Pelletier, Rick; Vile, Melanie A; Wieder, Kelman; Zaccone, Claudio; Zhang, Shuangquan


    Sphagnum moss was collected from 21 ombrotrophic (rain-fed) peat bogs surrounding open pit mines and upgrading facilities of Athabasca bituminous sands in Alberta (AB). In comparison to contemporary Sphagnum moss from four bogs in rural locations of southern Germany (DE), the AB mosses yielded lower concentrations of Ag, Cd, Ni, Pb, Sb, and Tl, similar concentrations of Mo, but greater concentrations of Ba, Th, and V. Except for V, in comparison to the "cleanest", ancient peat samples ever tested from the northern hemisphere (ca. 6000-9000 years old), the concentrations of each of these metals in the AB mosses are within a factor of 3 of "natural, background" values. The concentrations of "heavy metals" in the mosses, however, are proportional to the concentration of Th (a conservative, lithophile element) and, therefore, contributed to the plants primarily in the form of mineral dust particles. Vanadium, the single most abundant trace metal in bitumen, is the only anomaly: in the AB mosses, V exceeds that of ancient peat by a factor of 6; it is therefore enriched in the mosses, relative to Th, by a factor of 2. In comparison to the surface layer of peat cores collected in recent years from across Canada, from British Columbia to New Brunswick, the Pb concentrations in the mosses from AB are far lower.

  17. Strategy to Conduct Quantitative Ecohydrologic Analysis of a UNESCO World Heritage Site: the Peace-Athabasca Delta, Canada (United States)

    Ward, E. M.; Gorelick, S.; Hadly, E. A.


    The 6000 km2 Peace-Athabasca Delta ("Delta") in northeastern Alberta, Canada, is a Ramsar Convention Wetland and UNESCO World Heritage Site ("in Danger" status pending) where hydropower development and climate change are creating ecological impacts through desiccation and reduction in Delta shoreline habitat. We focus on ecohydrologic changes and mitigation and adaptation options to advance the field of ecohydrology using interdisciplinary technology by combining, for the first time, satellite remote sensing and hydrologic simulation with individual-based population modeling of muskrat (Ondatra zibethicus), a species native to the Delta whose population dynamics are strongly controlled by the hydrology of floodplain lakes. We are building a conceptual and quantitative modeling framework linking climate change, upstream water demand, and hydrologic change in the floodplain to muskrat population dynamics with the objective of exploring the impacts of these stressors on this ecosystem. We explicitly account for cultural and humanistic influences and are committed to effective communication with the regional subsistence community that depends on muskrat for food and income. Our modeling framework can ultimately serve as the basis for improved stewardship and sustainable development upstream of stressed freshwater deltaic, coastal and lake systems worldwide affected by climate change, providing a predictive tool to quantify population changes of animals relevant to regional subsistence food security and commercial trapping.

  18. Modelling boreal lake catchment response to anthropogenic acid deposition

    Directory of Open Access Journals (Sweden)

    Shaun A. WATMOUGH


    Full Text Available A dynamic hydrogeochemical model of water acidification (MAGIC: Model of Acidification of Groundwater in Catchments was applied to two catchments with contrasting hydrological influences in the Athabasca Oil Sands Region of Alberta to predict catchment response to elevated levels of acidic deposition. Key processes that determine catchment response to atmospheric deposition, including groundwater base cation inputs and retention of sulphur (S in peatland complexes were parameterized in the model. Although deposition of S and nitrogen (N in the region has increased over the last 40 years, levels are low at the study sites relative to impacted areas of eastern North America. Model forecasts for the period 2005–2100 were run under constant 2005 deposition levels (base case and at acid deposition double this level. Simulated past and future soil base saturation was constant over the course of the 200 year (1900–2100 modelled period. At the lake with high charge balance acid neutralizing capacity (ANCCB, where large base cation sources dominate lake chemistry, little change in surface water chemistry was predicted under either forecast scenario. Under the double acid forecast scenario at the low ANCCB lake, simulated lake ANCCB decreased in response to elevated S deposition, but the magnitude of decrease was comparable to the range in observational data. The simulations suggest limited risk of acidification, primarily due to S retention in the catchments, but the potential for drought-induced episodic depression of ANCCB may be important on this landscape.

  19. Distribution of clay minerals in the process streams produced by the extraction of bitumen from Athabasca oil sands

    Energy Technology Data Exchange (ETDEWEB)

    Kaminsky, H.A.W.; Etsell, T.H.; Ivey, D.G. [Alberta Univ., Edmonton, AB (Canada). Dept. of Chemical and Materials Engineering; Omotoso, O. [Natural Resources Canada, Devon, AB (Canada). CETC


    The clay minerals present in the oil sands were studied with particular reference to how they are partitioned in bitumen ore during the extraction process. Bitumen production from surface-mined oil sands accounts for nearly two-thirds of the total bitumen production in Alberta. Every cubic meter of mined ore results in 1.3 cubic meters of mature fine tailings (MFT). The characteristic differences between the clay minerals that report to the froth versus the tailings streams were also examined to determine which minerals could impact different unit operations in the bitumen extraction process. X-ray diffraction and random powder samples were used to quantify the clay minerals. Particle size distribution and clay activity balances were also conducted. The degree of partitioning during the conditioning and flotation stages in a batch extractor was determined by the surface properties of the clay minerals. The water-continuous tailings stream was separated into fine and coarse tailings fractions through sedimentation. The study showed that bitumen-clay interactions may be dominated by kaolinite or iron oxides. Clays are responsible for the poor settling behaviour of MFTs. The clay minerals present in the oil sands include illite, illite-smectite, kaolinite, kaolinite-smectite, and chlorite. The close proximity of the tailings ponds to the Athabasca River and volatile organic compounds (VOCs) emission require that the ponds be reclaimed to a natural landscape before mine closure. In addition to its impact on fine tailings reclamation, clay mineralogy plays a role in extraction froth flotation and emulsion stability during froth treatment. The mineralogy of the froth solids was found to be different from the mineralogy of the middlings and tailings solids. 39 refs., 6 tabs., 6 figs.

  20. Carbon dynamics, food web structure and reclamation strategies in Athabasca oil sands wetlands (CFRAW) : overview and progress

    Energy Technology Data Exchange (ETDEWEB)

    Ciborowski, J. [Windsor Univ., Windsor, ON (Canada); Dixon, D.G. [Waterloo Univ., Waterloo, ON (Canada); Foote, L. [Alberta Univ., Edmonton, AB (Canada); Liber, K.; Smits, J.E. [Saskatchewan Univ., Saskatoon, SK (Canada)


    Seven oil sand mining partners and 5 university labs have joined forces to study the effects of mine tailings and process waters on development, health and function of wetland communities formed in post-mining landscapes. The collaborative effort, know as the carbon dynamics, food web structure and reclamation strategies in Athabasca oil sands wetlands (CRFAW), aims to identify the materials and strategies most effective and economical in producing a functioning reclamation landscape. This presentation reported on part of the study that tested predictions about how quickly wetlands amended with reclamation materials approach the conditions of reference wetland systems. It provided a conceptual model of carbon pathways and budgets to assess how the allocation of carbon among compartments changes as newly formed wetlands mature in the boreal system. It was assumed that stockpiling constructed wetlands with peat or topsoil would accelerate succession and community development. Although the bitumen and the naphthenic acids found in constructed wetlands are initially toxic, they may serve as an alternate source of carbon once they degrade. This study also assessed the sources, biological uptake, pathways, and movement through the food web of materials used by the biota in constructed wetlands. Additional studies are examining how the productivity of new wetlands is maintained. Net ecosystem productivity is being monitored along with rates of organic carbon accumulation from microbial, algal, and macrophyte production, and influx of outside materials. The rates of leaf litter breakdown and microbial respiration are being compared to determine how constituents speed or slow food web processes of young and older wetlands. Carbon and nitrogen isotope values in food web compartments indicate which sources are incorporated into the food web as wetlands age. The values are used to determine how this influences community development, food web structure and complexity, and the

  1. Size-resolved Pb distribution in the Athabasca River shows snowmelt in the bituminous sands region an insignificant source of dissolved Pb (United States)

    Javed, Muhammad Babar; Cuss, Chad W.; Grant-Weaver, Iain; Shotyk, William


    Lead (Pb) is a metal of special importance because of its long history of commercial and industrial use, global atmospheric contamination accelerated by the use of gasoline additives, and health effects, with children being especially vulnerable. Global atmospheric Pb pollution reached its zenith in the 1970’s, but subsequent impacts on freshwater aquatic systems are poorly understood. Employing metal-free sampling and handling protocols, we show that snowmelt from the Athabasca bituminous sands region is an insignificant source of dissolved Pb to the Athabasca River (AR). Total Pb in the AR is low, and almost entirely in particulate form. Lead in the suspended solids in the AR exactly follows thorium (Th), a conservative lithophile element, and a linear regression of Pb against Th (Pb = 1.6 × Th + 0.0 R2 = 0.99) yields a slope identical to the Pb/Th ratio in the Upper Continental Crust. In the “dissolved” fraction, the Pb/Th ratio is equivalent to that of deep, open ocean seawater; and dominated by colloidal forms. Taken together, these results show that the efforts of recent decades to reduce anthropogenic Pb to the environment have been successful: Pb loading to the river can now be explained predominantly by natural processes, namely erosion plus chemical weathering.

  2. Estimation of vanadium water quality benchmarks for the protection of aquatic life with relevance to the Athabasca Oil Sands region using species sensitivity distributions. (United States)

    Schiffer, Stephanie; Liber, Karsten


    Elevated vanadium (V) concentrations in oil sands coke, which is produced and stored on site of some major Athabasca Oil Sands companies, could pose a risk to aquatic ecosystems in northern Alberta, Canada, depending on its future storage and utilization. In the present study, V toxicity was determined in reconstituted Athabasca River water to various freshwater organisms, including 2 midge species (Chironomus dilutus and Chironomus riparius; 4-d and 30-d to 40-d exposures) and 2 freshwater fish species (Oncorhynchus mykiss and Pimephales promelas; 4-d and 28-d exposures) to facilitate estimation of water quality benchmarks. The acute toxicity of V was 52.0 and 63.2 mg/L for C. dilutus and C. riparius, respectively, and 4.0 and 14.8 mg V/L for P. promelas and O. mykiss, respectively. Vanadium exposure significantly impaired adult emergence of C. dilutus and C. riparius at concentrations ≥16.7 (31.6% reduction) and 8.3 (18.0% reduction) mg/L, respectively. Chronic toxicity in fish presented as lethality, with chronic 28-d LC50s of 0.5 and 4.3 mg/L for P. promelas and O. mykiss, respectively. These data were combined with data from the peer-reviewed literature, and separate acute and chronic species sensitivity distributions (SSDs) were constructed. The acute and chronic hazardous concentrations endangering only 5% of species (HC5) were estimated as 0.64 and 0.05 mg V/L, respectively. These new data for V toxicity to aquatic organisms ensure that there are now adequate data available for regulatory agencies to develop appropriate water quality guidelines for use in the Athabasca Oil Sands region and elsewhere. Until then, the HC5 values presented in the present study could serve as interim benchmarks for the protection of aquatic life from exposure to hazardous levels of V in local aquatic environments. Environ Toxicol Chem 2017;36:3034-3044. © 2017 SETAC. © 2017 SETAC.

  3. Distribution of naphthenic acids in tissues of laboratory-exposed fish and in wild fishes from near the Athabasca oil sands in Alberta, Canada. (United States)

    Young, Rozlyn F; Michel, Lorelei Martínez; Fedorak, Phillip M


    Naphthenic acids, which have a variety of commercial applications, occur naturally in conventional crude oil and in highly biodegraded petroleum such as that found in the Athabasca oil sands in Alberta, Canada. Oil sands extraction is done using a caustic aqueous extraction process. The alkaline pH releases the naphthenic acids from the oil sands and dissolves them into water as their soluble naphthenate forms, which are anionic surfactants. These aqueous extracts contain concentrations of naphthenates that are acutely lethal to fishes and other aquatic organisms. Previous research has shown that naphthenic acids can be taken up by fish, but the distribution of these acids in various tissues of the fish has not been determined. In this study, rainbow trout (Oncorhynchus mykiss) were exposed to commercial (Merichem) naphthenic acids in the laboratory. After a 10-d exposure to approximately 3mg naphthenic acids/L, the fish were dissected and samples of gills, heart, liver, kidney, muscle, and eggs were extracted and analyzed for free (unconjugated) naphthenic acids by a gas chromatography-mass spectrometry method. Each of the tissues contained naphthenic acids and non-parametric statistical analyses showed that gills and livers contained higher concentrations than the muscles and that the livers had higher concentrations than the hearts. Four different species of fish (two fish of each species) were collected from the Athabasca River near two oil sands mining and extraction operations. No free naphthenic acids were detected in the muscle or liver of these fish. Copyright © 2010 Elsevier Inc. All rights reserved.

  4. Toxicity of aqueous vanadium to zooplankton and phytoplankton species of relevance to the athabasca oil sands region. (United States)

    Schiffer, Stephanie; Liber, Karsten


    Vanadium (V) is an abundant trace metal present in bitumen from the Athabasca Oil Sands (AOS) region in Alberta, Canada. The upgrading of bitumen can result in the production of large volumes of a carbonaceous material referred to as petroleum coke that contains V at elevated levels compared to the native bitumen. Previous studies have shown that coke has the capacity to leach ecotoxicologically relevant levels of V into water it contacts, yet limited data are available on the toxicity of aqueous V to planktonic organisms. Therefore, this study set out to evaluate the acute and chronic toxicity of V (as vanadate oxyanions) to freshwater zooplankton and phytoplankton species that are either commonly-used laboratory species, or species more regionally-representative of northern Alberta. Four cladoceran (2-d and 21-d tests) and two algal (3-d tests) species were exposed to V to obtain both acute and chronic toxicity estimates. Acute V toxicity (LC50s) ranged from 0.60mgV/L for Ceriodaphnia quadrangula to 2.17mgV/L for Daphnia pulex. Chronic toxicity estimates (EC50s) for cladoceran survival and reproduction were nearly identical within species and ranged from a low of 0.13 to a high of 0.46mgV/L for Daphnia dentifera and D. pulex, respectively. The lack of sublethal V toxicity in daphnia suggests a direct mechanism of toxicity through ion imbalance. Growth inhibition (EC50) of green algae occurred at concentrations of 3.24 and 4.12mgV/L for Pseudokirchneriella subcapitata and Scenedesmus quadricauda, respectively. Overall, cladocerans were more sensitive to V than green algae, with survival of the field-collected D. dentifera being approximately 2.5 to 3.5 times more sensitive to acute and chronic V exposure than the standard test species D. pulex. However, there were no significant differences in V toxicity between the field-collected cladocerans Simocephalus serrulatus and C. quadrangula, compared to the respective standard species D. pulex and Ceriodaphnia dubia

  5. Chironomidae larvae from the lower Athabasca River, AB, Canada and its tributaries including macroscopic subfamily and tribe keys, indices for environmental tolerance and trait-based information for biomonitoring

    Directory of Open Access Journals (Sweden)

    A. Namayandeh


    Full Text Available Since 2011 the Joint Oil Sands Monitoring (JOSM program has been conducted in the lower Athabasca River by the Governments of Canada and Alberta to assess the freshwater health in areas associated with oil sands development. The majority of the benthic invertebrate assemblage of the Athabasca River and its tributaries are Chironomidae larvae. Assessments of such benthic assemblages are made difficult because the identification of Chironomidae larvae is costly and time consuming. To facilitate this identification process, we aimed to develop a simple taxonomic key for Chironomidae larvae of this region. This taxonomic reference and identification key makes use of the known taxonomic details on these Chironomidae species. Moreover, we provide details on their geographical distribution, ecology, habitats, environmental tolerance values for species, and traitbased morphological characters. Our main goal was to make this information readily available to both non-specialists and specialists so that biomonitoring programs can more readily utilize these organisms in biomonitoring.

  6. Parasite community similarity in Athabasca River trout-perch (Percopsis omiscomaycus) varies with local-scale land use and sediment hydrocarbons, but not distance or linear gradients. (United States)

    Blanar, C A; Hewitt, M; McMaster, M; Kirk, J; Wang, Z; Norwood, W; Marcogliese, D J


    Parasite communities have been shown to be structured by processes at scales ranging from continental to microhabitat, but few studies have simultaneously considered spatial and environmental variables, measured at different scales, to assess their relative influences on parasite abundance, species richness, and community similarity. Parasite abundance, diversity, and community similarity in Athabasca River trout-perch (Percopsis omiscomaycus) were examined in relation to water quality, substrate profile, metal and organic compound levels in water and sediment, and landscape use patterns at different scales, as well as distance among sites and upstream-downstream position along the river. Although species richness did not differ among sites, there were significant differences in abundance of individual taxa and community structure. We observed a shift from communities dominated by larval trematodes Diplostomum spp. to domination by gill monogeneans Urocleidus baldwini, followed by a reversion further downstream. Variations in the abundance of these taxa and of overall community similarity were strongly correlated with sediment hydrocarbons (alkanes and polycyclic aromatic hydrocarbons (PAHs)) as well as landscape use within 5 km of study sites. No correlations were noted with any other predictors, indicating that parasite populations and communities in this system were likely primarily influenced by habitat level and landscape-scale filters, rather than larger-scale processes such as distance decay or river continuum effects.

  7. 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)


    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.

  8. High-resolution projections of 21st century climate over the Athabasca River Basin through an integrated evaluation-classification-downscaling-based climate projection framework (United States)

    Cheng, Guanhui; Huang, Guohe; Dong, Cong; Zhu, Jinxin; Zhou, Xiong; Yao, Y.


    An evaluation-classification-downscaling-based climate projection (ECDoCP) framework is developed to fill a methodological gap of general circulation models (GCMs)-driven statistical-downscaling-based climate projections. ECDoCP includes four interconnected modules: GCM evaluation, climate classification, statistical downscaling, and climate projection. Monthly averages of daily minimum (Tmin) and maximum (Tmax) temperature and daily cumulative precipitation (Prec) over the Athabasca River Basin (ARB) at a 10 km resolution in the 21st century under four Representative Concentration Pathways (RCPs) are projected through ECDoCP. At the octodecadal scale, temperature and precipitation would increase; after bias correction, temperature would increase with a decreased increment, while precipitation would increase only under RCP 8.5. Interannual variability of climate anomalies would increase from RCPs 4.5, 2.6, 6.0 to 8.5 for temperature and from RCPs 2.6, 4.5, 6.0 to 8.5 for precipitation. Bidecadal averaged climate anomalies would decrease from December-January-February (DJF), March-April-May (MAM), September-October-November (SON) to June-July-August (JJA) for Tmin, from DJF, SON, MAM to JJA for Tmax, and from JJA, MAM, SON to DJF for Prec. Climate projection uncertainties would decrease in May to September for temperature and in November to April for precipitation. Spatial climatic variability would not obviously change with RCPs; climatic anomalies are highly correlated with climate-variable magnitudes. Climate anomalies would decrease from upstream to downstream for temperature, and precipitation would follow an opposite pattern. The north end and the other zones would have colder and warmer days, respectively; precipitation would decrease in the upstream and increase in the remaining region. Climate changes might lead to issues, e.g., accelerated glacier/snow melting, deserving attentions of researchers and the public.

  9. Deposit model for volcanogenic uranium deposits (United States)

    Breit, George N.; Hall, Susan M.


    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.

  10. Dust is the dominant source of "heavy metals" to peat moss (Sphagnum fuscum) in the bogs of the Athabasca Bituminous Sands region of northern Alberta. (United States)

    Shotyk, William; Bicalho, Beatriz; Cuss, Chad W; Duke, M John M; Noernberg, Tommy; Pelletier, Rick; Steinnes, Eiliv; Zaccone, Claudio


    Sphagnum fuscum was collected from twenty-five ombrotrophic (rain-fed) peat bogs surrounding open pit mines and upgrading facilities of Athabasca Bituminous Sands (ABS) in northern Alberta (AB) in order to assess the extent of atmospheric contamination by trace elements. As a control, this moss species was also collected at a bog near Utikuma (UTK) in an undeveloped part of AB and 264km SW of the ABS region. For comparison, this moss was also collected in central AB, in the vicinity of the City of Edmonton which is approximately 500km to the south of the ABS region, from the Wagner Wetland which is 22km W of the City, from Seba Beach (ca. 90km W) and from Elk Island National Park (ca. 45km E). All of the moss samples were digested and trace elements concentrations determined using ICP-SMS at a commercial laboratory, with selected samples also analyzed using instrumental neutron activation analysis at the University of Alberta. The mosses from the ABS region yielded lower concentrations of Ag, As, Bi, Cd, Cu, Pb, Sb, Tl, and Zn compared to the moss from the Edmonton area. Concentrations of Ni and Mo in the mosses were comparable in these two regions, but V was more abundant in the ABS samples. Compared with the surface vegetation of eight peat cores collected in recent years from British Columbia, Ontario, Quebec and New Brunswick, the mean concentrations of Ag, As, Bi, Cd, Cu, Mo, Ni, Pb, Sb, Tl and Zn in the mosses from the ABS region are generally much lower. In fact, the concentrations of these trace elements in the samples from the ABS region are comparable to the corresponding values in forest moss from remote regions of central and northern Norway. Lithophile element concentrations (Ba, Be, Ga, Ge, Li, Sc, Th, Ti, Zr) explain most of the variation in trace metal concentrations in the moss samples. The mean concentrations of Th and Zr are greatest in the moss samples from the ABS region, reflecting dust inputs to the bogs from open pit mines, aggregate

  11. Atmospheric Deposition Modeling Results (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...

  12. Electro-Deposition Laboratory (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...

  13. Calcium Pyrophosphate Deposition (CPPD) (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 ...

  14. Deposit Games with Reinvestment

    NARCIS (Netherlands)

    van Gulick, G.; Borm, P.E.M.; De Waegenaere, A.M.B.; Hendrickx, R.L.P.


    In a deposit game coalitions are formed by players combining their capital. The proceeds of their investments then have to be divided among those players. The current model extends earlier work on capital deposits by allowing reinvestment of returns. Two specific subclasses of deposit games are

  15. Using biofilms and grazing chironomids (Diptera: Chironomidae) to determine primary production, nitrogen stable isotopic baseline and enrichment within wetlands differing in anthropogenic stressors and located in the Athabasca oil sands region of Alberta

    Energy Technology Data Exchange (ETDEWEB)

    Frederick, K.; Ciborowski, J.J. [Windsor Univ., Windsor, ON (Canada); Wytrykush, C.M. [Syncrude Canada Ltd., Edmonton, AB (Canada)


    This presentation reported on a study that investigated the effects of oil sands process materials (OSPM) and construction disturbances on primary production and nitrogen stable isotope enrichment in reclaimed and reference wetlands at oil sands mines in the Athabasca basin. Productivity and food web analyses were instrumental in evaluating the succession and viability of reclaimed wetlands. Primary production was estimated through chlorophyll a (Chl a) concentrations and biomass. Carbon (C) and nitrogen (N) stable isotope ratios were used to identify energy sources, storage and the magnitude and direction of energy transfer within food webs. The objectives were to determine primary productivity, the N baseline, and N enrichment from biofilms and grazing invertebrates colonizing artificial substrates immersed in the water column of two OSPM-affected, two constructed reference and two natural reference wetlands. The lower biomass and Chl a concentrations in OSPM-affected and constructed wetlands suggests that both anthropogenic disturbance and OSPM have an adverse effect on primary productivity and overall wetland function.

  16. Shedding of ash deposits

    DEFF Research Database (Denmark)

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


    Ash deposits formed during fuel thermal conversion and located on furnace walls and on convective pass tubes, may seriously inhibit the transfer of heat to the working fluid and hence reduce the overall process efficiency. Combustion of biomass causes formation of large quantities of troublesome...... ash deposits which contain significant concentrations of alkali, and earth-alkali metals. The specific composition of biomass deposits give different characteristics as compared to coal ash deposits, i.e. different physical significance of the deposition mechanisms, lower melting temperatures, etc....... Low melting temperatures make straw ashes especially troublesome, since their stickiness is higher at lower temperatures, compared to coal ashes. Increased stickiness will eventually lead to a higher collection efficiency of incoming ash particles, meaning that the deposit may grow even faster...

  17. Petrography, fluid inclusion analysis, and geochronology of the End uranium deposit, Kiggavik, Nunavut, Canada (United States)

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


    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

  18. 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.


    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.

  19. Stratiform chromite deposit model (United States)

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


    Stratiform chromite deposits are of great economic importance, yet their origin and evolution remain highly debated. Layered igneous intrusions such as the Bushveld, Great Dyke, Kemi, and Stillwater Complexes, provide opportunities for studying magmatic differentiation processes and assimilation within the crust, as well as related ore-deposit formation. Chromite-rich seams within layered intrusions host the majority of the world's chromium reserves and may contain significant platinum-group-element (PGE) mineralization. This model of stratiform chromite deposits is part of an effort by the U.S. Geological Survey's Mineral Resources Program to update existing models and develop new descriptive mineral deposit models to supplement previously published models for use in mineral-resource and mineral-environmental assessments. The model focuses on features that may be common to all stratiform chromite deposits as a way to gain insight into the processes that gave rise to their emplacement and to the significant economic resources contained in them.

  20. Deposition and Resuspension Section

    Energy Technology Data Exchange (ETDEWEB)

    Slinn, W. G.N.; Horst, T. W.; Sehmel, G. A.; Hodgson, W. H.; Lloyd, F. D.; Orgill, M. M.; Bander, T. J.; Thorp, J. M.; Schwendiman, L. C.; Young, J. A.; Tanner, T. M.; Thomas, C. W.; Wogman, N. A.; Petersen, M. R.; Hadlock, R. K.; Droppo, J. G.; Woodruff, R. K.


    Nineteen papers are covered in this section. Significant contributions were made in 1975 in both the theoretical and the more practical experimental measurements of particle deposition and resuspension. Solutions of theoretical deposition-resuspension equations were formulated and nondimensionalized air and ground concentrations were predicted as a function of distance. In other theoretical studies assumptions and analyses regarding surface boundary conditions were investigated and methods presented whereby they can be fitted together within a single theoretical framework. Deposition in vegetation canopies was considered; formulations were developed and conclusions drawn regarding canopy filtration efficiency. Dry deposition of gases was shown to be rate-limited by many processes, and experiments and equipment were designed to measure gradients of SO/sub 2/ and deposition fluxes. A computer model was improved and used to predict downwind concentrations for a generalized area source. A dimensional analysis correlation was formulated from experimental particle deposition velocity data, but was found to show insignificant improvement when compared statistically with an earlier derived correlation. Wind tunnel measurements of deposition velocities to gravel beds and scaled trees showed that particles will penetrate very significantly to underlying surfaces. Initial field experiments measured deposition velocity to sagebrush canopies. Other controlled field studies were initiated for measuring resuspension, including resuspension from truck traffic. Suspension of soil and the size distribution of particles airborne under various air regimes were studied. In the large METROMEX study done near St. Louis, several pollutants were sampled and analyzed as a function of distance. These studies gave insight into the relative inportance of dry deposition and atmospheric dispersion as mechanisms for reducing air concentrations. (auth)

  1. Electroless atomic layer deposition

    Energy Technology Data Exchange (ETDEWEB)

    Robinson, David Bruce; Cappillino, Patrick J.; Sheridan, Leah B.; Stickney, John L.; Benson, David M.


    A method of electroless atomic layer deposition is described. The method electrolessly generates a layer of sacrificial material on a surface of a first material. The method adds doses of a solution of a second material to the substrate. The method performs a galvanic exchange reaction to oxidize away the layer of the sacrificial material and deposit a layer of the second material on the surface of the first material. The method can be repeated for a plurality of iterations in order to deposit a desired thickness of the second material on the surface of the first material.

  2. Alluvial Deposits in Iowa (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...

  3. Speleothem (Cave Deposit) Data (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...

  4. Automatic Payroll Deposit System. (United States)

    Davidson, D. B.


    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)

  5. Modeled Wet Nitrate Deposition (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...

  6. Podiform chromite deposits (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.

  7. Resedimented salt deposits

    Energy Technology Data Exchange (ETDEWEB)

    Slaczka, A.; Kolasa, K. (Jagiellonian Univ., Krakow (Poland))


    Carparthian foredeep's Wieliczka salt mine, unique gravity deposits were lately distinguished. They are mainly built of salt particles and blocks with a small admixture of fragments of Miocene marls and Carpathian rocks, deposited on precipitated salt. The pattern of sediment distribution is similar to a submarine fan. Gravels are dominant in the upper part and sands in lower levels, creating a series of lobes. Coarse-grained deposits are represented by disorganized, self-supported conglomerates passing into matrix-supported ones, locally with gradation, and pebbly sandstones consisting of salt grains and scattered boulder-size clasts. The latter may show in the upper part of a single bed as indistinct cross-bedding and parallel lamination. These sediments are interpreted as debris-flow and high-density turbidity current deposits. Salt sandstones (saltstones) which build a lower part of the fan often show Bouma sequences and are interpreted as turbidity-current deposits. The fan deposits are covered by a thick series of debrites (olistostromes) which consist of clay matrix with salt grains and boulders. The latter as represented by huge (up to 100,000 m{sup 3}) salt blocks, fragments of Miocene marls and Carpathian rocks. These salt debrites represent slumps and debris-flow deposits. The material for resedimented deposits was derived from the southern part of the salt basin and from the adjacent, advancing Carpathian orogen. The authors believe the distinct coarsening-upward sequence of the series is the result of progressive intensification of tectonic movements with paroxysm during the sedimentation of salt debrites (about 15 Ma).

  8. Plant Community and Nitrogen Deposition as Drivers of Alpha and Beta Diversities of Prokaryotes in Reconstructed Oil Sand Soils and Natural Boreal Forest Soils (United States)

    Prescott, Cindy E.; Renaut, Sébastien; Terrat, Yves; Grayston, Sue J.


    ABSTRACT The Athabasca oil sand deposit is one of the largest single oil deposits in the world. Following surface mining, companies are required to restore soil-like profiles that can support the previous land capabilities. The objective of this study was to assess whether the soil prokaryotic alpha diversity (α-diversity) and β-diversity in oil sand soils reconstructed 20 to 30 years previously and planted to one of three vegetation types (coniferous or deciduous trees and grassland) were similar to those found in natural boreal forest soils subject to wildfire disturbance. Prokaryotic α-diversity and β-diversity were assessed using massively parallel sequencing of 16S rRNA genes. The β-diversity, but not the α-diversity, differed between reconstructed and natural soils. Bacteria associated with an oligotrophic lifestyle were more abundant in natural forest soils, whereas bacteria associated with a copiotrophic lifestyle were more abundant in reconstructed soils. Ammonia-oxidizing archaea were most abundant in reconstructed soils planted with grasses. Plant species were the main factor influencing α-diversity in natural and in reconstructed soils. Nitrogen deposition, pH, and plant species were the main factors influencing the β-diversity of the prokaryotic communities in natural and reconstructed soils. The results highlight the importance of nitrogen deposition and aboveground-belowground relationships in shaping soil microbial communities in natural and reconstructed soils. IMPORTANCE Covering over 800 km2, land disturbed by the exploitation of the oil sands in Canada has to be restored. Here, we take advantage of the proximity between these reconstructed ecosystems and the boreal forest surrounding the oil sand mining area to study soil microbial community structure and processes in both natural and nonnatural environments. By identifying key characteristics shaping the structure of soil microbial communities, this study improved our understanding of

  9. Plant Community and Nitrogen Deposition as Drivers of Alpha and Beta Diversities of Prokaryotes in Reconstructed Oil Sand Soils and Natural Boreal Forest Soils. (United States)

    Masse, Jacynthe; Prescott, Cindy E; Renaut, Sébastien; Terrat, Yves; Grayston, Sue J


    The Athabasca oil sand deposit is one of the largest single oil deposits in the world. Following surface mining, companies are required to restore soil-like profiles that can support the previous land capabilities. The objective of this study was to assess whether the soil prokaryotic alpha diversity (α-diversity) and β-diversity in oil sand soils reconstructed 20 to 30 years previously and planted to one of three vegetation types (coniferous or deciduous trees and grassland) were similar to those found in natural boreal forest soils subject to wildfire disturbance. Prokaryotic α-diversity and β-diversity were assessed using massively parallel sequencing of 16S rRNA genes. The β-diversity, but not the α-diversity, differed between reconstructed and natural soils. Bacteria associated with an oligotrophic lifestyle were more abundant in natural forest soils, whereas bacteria associated with a copiotrophic lifestyle were more abundant in reconstructed soils. Ammonia-oxidizing archaea were most abundant in reconstructed soils planted with grasses. Plant species were the main factor influencing α-diversity in natural and in reconstructed soils. Nitrogen deposition, pH, and plant species were the main factors influencing the β-diversity of the prokaryotic communities in natural and reconstructed soils. The results highlight the importance of nitrogen deposition and aboveground-belowground relationships in shaping soil microbial communities in natural and reconstructed soils.IMPORTANCE Covering over 800 km2, land disturbed by the exploitation of the oil sands in Canada has to be restored. Here, we take advantage of the proximity between these reconstructed ecosystems and the boreal forest surrounding the oil sand mining area to study soil microbial community structure and processes in both natural and nonnatural environments. By identifying key characteristics shaping the structure of soil microbial communities, this study improved our understanding of how

  10. Reactive polymer fused deposition manufacturing (United States)

    Kunc, Vlastimil; Rios, Orlando; Love, Lonnie J.; Duty, Chad E.; Johs, Alexander


    Methods and compositions for additive manufacturing that include reactive or thermosetting polymers, such as urethanes and epoxies. The polymers are melted, partially cross-linked prior to the depositing, deposited to form a component object, solidified, and fully cross-linked. These polymers form networks of chemical bonds that span the deposited layers. Application of a directional electromagnetic field can be applied to aromatic polymers after deposition to align the polymers for improved bonding between the deposited layers.

  11. Air pollution and dry deposition of nitrogen and sulphur in the AOSR estimated using passive samplers (United States)

    Yu-Mei Hsu; Andrzej Bytnerowicz


    NO2 and SO2 are the primary pollutants produced by industrial facilities of the Athabasca Oil sand Region (AOSR), Alberta, Canada. The major emission sources are the upgrader stacks for SO2 and stacks, mine fleets and vehicles for NO2. After emitting from the sources, NO

  12. Electrophoretic deposition of biomaterials (United States)

    Boccaccini, A. R.; Keim, S.; Ma, R.; Li, Y.; Zhitomirsky, I.


    Electrophoretic deposition (EPD) is attracting increasing attention as an effective technique for the processing of biomaterials, specifically bioactive coatings and biomedical nanostructures. The well-known advantages of EPD for the production of a wide range of microstructures and nanostructures as well as unique and complex material combinations are being exploited, starting from well-dispersed suspensions of biomaterials in particulate form (microsized and nanoscale particles, nanotubes, nanoplatelets). EPD of biological entities such as enzymes, bacteria and cells is also being investigated. The review presents a comprehensive summary and discussion of relevant recent work on EPD describing the specific application of the technique in the processing of several biomaterials, focusing on (i) conventional bioactive (inorganic) coatings, e.g. hydroxyapatite or bioactive glass coatings on orthopaedic implants, and (ii) biomedical nanostructures, including biopolymer–ceramic nanocomposites, carbon nanotube coatings, tissue engineering scaffolds, deposition of proteins and other biological entities for sensors and advanced functional coatings. It is the intention to inform the reader on how EPD has become an important tool in advanced biomaterials processing, as a convenient alternative to conventional methods, and to present the potential of the technique to manipulate and control the deposition of a range of nanomaterials of interest in the biomedical and biotechnology fields. PMID:20504802

  13. Aerosol deposition on plant leaves (United States)

    James B. Wedding; Roger W. Carlson; James J. Stukel; Fakhri A. Bazzaz


    An aerosol generator and wind tunnel system designed for use in aerosol deposition is described. Gross deposition on rough pubescent leaves was nearly 7 times greater than on smooth, waxy leaves. Results suggest that aerosol deposition, on a per unit area basis, for single horizontal streamlining leaves is similar to that for arrays of leaves under similar flow...

  14. A Micrometeorological Perspective on Deposition

    DEFF Research Database (Denmark)

    Jensen, Niels Otto


    An expression for the dry deposition velocity is given in terms of constant flux layer scaling. Numerical values of upper bounds on the deposition velocity is given for a typical situation. Some remarks are then offered on the relative merits of various ways in which the combined diffusion-deposition...

  15. Electrophoretic Deposition of Gallium with High Deposition Rate

    Directory of Open Access Journals (Sweden)

    Hanfei Zhang


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

  16. Limited Deposit Insurance Coverage and Bank Competition


    SHY, Oz; Stenbacka, Rune; Yankov, Vladimir


    Deposit insurance schemes 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...

  17. Variations in the uranium isotopic compositions of uranium ores from different types of uranium deposits (United States)

    Uvarova, Yulia A.; Kyser, T. Kurt; Geagea, Majdi Lahd; Chipley, Don


    Variations in 238U/235U and 234U/238U ratios were measured in uranium minerals from a spectrum of uranium deposit types, as well as diagenetic phosphates in uranium-rich basins and peraluminous rhyolites and associated autunite mineralisation from Macusani Meseta, Peru. Mean δ238U values of uranium minerals relative to NBL CRM 112-A are 0.02‰ for metasomatic deposits, 0.16‰ for intrusive, 0.18‰ for calcrete, 0.18‰ for volcanic, 0.29‰ for quartz-pebble conglomerate, 0.29‰ for sandstone-hosted, 0.44‰ for unconformity-type, and 0.56‰ for vein, with a total range in δ238U values from -0.30‰ to 1.52‰. Uranium mineralisation associated with igneous systems, including low-temperature calcretes that are sourced from U-rich minerals in igneous systems, have low δ238U values of ca. 0.1‰, near those of their igneous sources, whereas uranium minerals in basin-hosted deposits have higher and more variable values. High-grade unconformity-related deposits have δ238U values around 0.2‰, whereas lower grade unconformity-type deposits in the Athabasca, Kombolgie and Otish basins have higher δ238U values. The δ234U values for most samples are around 0‰, in secular equilibrium, but some samples have δ234U values much lower or higher than 0‰ associated with addition or removal of 234U during the past 2.5 Ma. These δ238U and δ234U values suggest that there are at least two different mechanisms responsible for 238U/235U and 234U/238U variations. The 234U/238U disequilibria ratios indicate recent fluid interaction with the uranium minerals and preferential migration of 234U. Fractionation between 235U and 238U is a result of nuclear-field effects with enrichment of 238U in the reduced insoluble species (mostly UO2) and 235U in oxidised mobile species as uranyl ion, UO22+, and its complexes. Therefore, isotopic fractionation effects should be reflected in 238U/235U ratios in uranium ore minerals formed either by reduction of uranium to UO2 or chemical

  18. Radioactive deposits in California (United States)

    Walker, George W.; Lovering, Tom G.


    Reconnaissance examination by Government geologists of many areas, mine properties, and prospects in California during the period between 1948 and 1953 has confirmed the presence of radioactive materials in place at more than 40 localities. Abnormal radioactivity at these localities is due to concentrations of primary and secondary uranium minerals, to radon gas, radium (?), and to thorium minerals. Of the known occurrences only three were thought to contain uranium oxide (uranitite or pitchblende), 4 contained uranium-bearing columbate, tantalate, or titanate minerals, 12 contained secondary uranium minerals, such as autunite, carnotite, and torbernite, one contained radon gas, 7 contained thorium minerals, and, at the remaining 16 localities, the source of the anomalous radiation was not positively determined. The occurrences in which uranium oxide has been tentatively identified include the Rathgeb mine (Calaveras County), the Yerih group of claims (San Bernardino County), and the Rainbow claim (Madera County). Occurrences of secondary uranium minerals are largely confined to the arid desert regions of south-eastern California including deposits in San Bernardino, Kern, Inyo, and Imperial Counties. Uranium-bearing columbate, tantalate, or titanate minerals have been reported from pegmatite and granitic rock in southeastern and eastern California. Thorium minerals have been found in vein deposits in eastern San Bernardino County and from pegmatites and granitic rocks in various parts of southeastern California; placer concentrations of thorium minerals are known from nearly all areas in the State that are underlain, in part, by plutonic crystalline rocks. The primary uranium minerals occur principally as minute accessory crystals in pegmatite or granitic rock, or with base-metal sulfide minerals in veins. Thorium minerals also occur as accessory crystals in pegmatite or granitic rock, in placer deposits derived from such rock, and, at Mountain Pass, in veins

  19. FDIC Summary of Deposits (SOD) Download File (United States)

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

  20. Ballistic Deposition of Nanoclusters. (United States)

    Ulbrandt, Jeffrey; Li, Yang; Headrick, Randall

    Nanoporous thin-films are an important class of materials, possessing a large surface area to volume ratio, with applications ranging from thermoelectric and photovoltaic materials to supercapacitors. In-Situ X-ray Reflectivity and Grazing Incidence Small Angle X-Ray Scattering (GISAXS) were used to monitor thin-films grown from Tungsten Silicide (WSi2) and Copper (Cu) nanoclusters. The nanoclusters ranged in size from 2 nm to 6 nm diameter and were made by high-pressure magnetron sputtering via plasma gas condensation (PGC). X-Ray Reflectivity (XRR) measurements of the films at various stages of growth reveal that the resulting films exhibit very low density, approaching 15% of bulk density. This is consistent with a simple off-lattice ballistic deposition model where particles stick at the point of first contact without further restructuring. DOE Office of Basic Energy Sciences under contract DE-FG02-07ER46380.

  1. 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)


    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)

  2. Liquefier Dynamics in Fused Deposition

    DEFF Research Database (Denmark)

    Bellini, Anna; Guceri, Selcuk; Bertoldi, Maurizio


    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 are then stac......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...

  3. (Acidic deposition and the environment)

    Energy Technology Data Exchange (ETDEWEB)

    Garten, C.T.; Lindberg, S.E.; Van Miegroet, H.


    The travelers presented several papers at the Fourth International Conference on Acidic Deposition. These covered the following topics: atmospheric chemistry and deposition of airborne nitrogen compounds, soil solution chemistry in high-elevation spruce forests, and forest throughfall measurements for estimating total sulfur deposition to ecosystems. In addition, S. E. Lindberg was invited to organize and chair a conference session on Throughfall and Stemflow Experiments, and to present an invited lecture on Atmospheric Deposition and Canopy Interactions of Metals and Nitrogen in Forest Ecosystems: The Influence of Global Change'' at the 110th Anniversary Celebration of the Free University of Amsterdam.

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

    Energy Technology Data Exchange (ETDEWEB)

    MacDonald, Lauren A., E-mail: [Department of Biology, University of Waterloo, Waterloo, ON N2L 3G1 (Canada); Wiklund, Johan A. [Department of Biology, University of Waterloo, Waterloo, ON N2L 3G1 (Canada); Elmes, Matthew C.; Wolfe, Brent B. [Department of Geography and Environmental Studies, Wilfrid Laurier University, Waterloo, ON N2L 3C5 (Canada); Hall, Roland I., E-mail: [Department of Biology, University of Waterloo, Waterloo, ON N2L 3G1 (Canada)


    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. - Highlights: • We examine metal depositional history at a

  5. 78 FR 11604 - Deposit Insurance Regulations; Definition of Insured Deposit (United States)


    ..., (202) 898-3670; F. Angus Tarpley III, Supervisory Counsel, Legal Division, (202) 898-6646; Catherine... required to repay a deposit in a foreign branch if it cannot do so because of ``war, insurrection, or civil... the world. The U.K. FSA currently has proposed that the rules governing deposit-taking by foreign...

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

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


    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. Variable temperature semiconductor film deposition (United States)

    Li, X.; Sheldon, P.


    A method of depositing a semiconductor material on a substrate is disclosed. 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.

  8. 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...

  9. Geotechnical Description of Mineral Deposits

    Directory of Open Access Journals (Sweden)

    Sasvári Tibor


    Full Text Available Performing various mineral deposits extraction methods requires thorough knowledge of the rock masses` geomechanical parameters. In the geotechnical description of mineral deposits there is proposed a methodical approarch at the collection, registration, and evaluation of rock masses` geological properties for geotechnics being applied within the mining industry.

  10. A remote coal deposit revisited

    DEFF Research Database (Denmark)

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


    In 1908, members of the “Danmark Expedition” discovered a coal deposit in a very remote area in western Germania Land, close to the margin of the inland ice in northeast Greenland. The deposit was, however, neither sampled nor described, and was revisited in 2009 for the first time since its...


    Energy Technology Data Exchange (ETDEWEB)

    Michael Volk; Cem Sarica


    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

  12. 76 FR 21265 - Interest on Deposits; Deposit Insurance Coverage (United States)


    ..., Federal Deposit Insurance Corporation, 550 17th Street, NW., Washington, DC 20429. Hand Delivery: Guard... Treasury and General Government Appropriations Act, enacted as part of the Omnibus Consolidated and...

  13. 76 FR 41392 - Interest on Deposits; Deposit Insurance Coverage (United States)


    ... volatility as depository institutions competed for an increased share of business deposits by offering... earnings credits. A third commenter urged that the Financial Stability Oversight Council (the FSOC) should...

  14. Atmospheric deposition 2000. NOVA 2003; Atmosfaerisk deposition 2000. NOVA 2003

    Energy Technology Data Exchange (ETDEWEB)

    Ellermann, T.; Hertel, O.; Hovmand, M.F.; Kemp, K.; Skjoeth, C.A.


    This report presents measurements and calculations from the atmospheric part of NOVA 2003 and covers results for 2000. It summarises the main results concerning concentrations and depositions of nitrogen, phosphorus and sulphur compounds related to eutrophication and acidification. Depositions of atmospheric compounds to Danish marine waters as well as land surface are presented. Measurements: In 2000 the monitoring program consisted of eight stations where wet deposition of ammonium, nitrate, phosphate (semi quantitatively) and sulphate were measured using bulk precipitation samplers. Six of the stations had in addition measurements of atmospheric content of A, nitrogen, phosphorus, and sulphur compounds in gas and particulate phase carried out by use of filter pack samplers. Filters were analysed at the National Environmental Research Institute. Furthermore nitrogen dioxide were measured using nitrogen dioxide filter samplers and monitors. Model calculations: The measurements in the monitoring program were supplemented with model calculations of concentrations and depositions of nitrogen and sulphur compounds to Danish land surface, marine waters, fjords and bays using the ACDEP model (Atmospheric Chemistry and Deposition). The model is a so-called trajectory model and simulates the physical and chemical processes in the atmosphere using meteorological and emission data as input. The advantage of combining measurements with model calculations is that the strengths of both methods is obtained. Conclusions concerning: 1) actual concentration levels at the monitoring stations, 2) deposition at the monitoring stations, 3) seasonal variations and 4) long term trends in concentrations and depositions are mainly based on the direct measurements. These are furthermore used to validate the results of the model calculations. Calculations and conclusions concerning: 1) depositions to land surface and to the individual marine water, 2) contributions from different emission


    Directory of Open Access Journals (Sweden)

    Branko Crnković


    Full Text Available The geology, petrographycal composition and properties of dimension stone deposits in Croatia are described. Dimension stone deposits in the conception of mobilistic view of the genesis and structure of Dinarides, as well as after stratigraphic units, are considered. Valuation of the dimension stones of the active quarries is exposed. The marketable categories of dimension stone in Croatia are different varietes of limestones and calcareous clastites, primarly of Cretaceous age, and to lesser degree of Jurassic and Paleogene. The greatest part of deposits is concentrated in the Adriatic carbonate platform or Adriaticum.

  16. Particle deposition in ventilation ducts

    Energy Technology Data Exchange (ETDEWEB)

    Sippola, Mark Raymond [Univ. of California, Berkeley, CA (United States)


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

  17. Atomic layer deposition for semiconductors

    CERN Document Server

    Hwang, Cheol Seong


    This edited volume discusses atomic layer deposition (ALD) for all modern semiconductor devices, moving from the basic chemistry of ALD and modeling of ALD processes to sections on ALD for memories, logic devices, and machines.

  18. Hereditary iron and copper deposition

    DEFF Research Database (Denmark)

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


    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...

  19. Electrospark deposition for die repair

    Directory of Open Access Journals (Sweden)

    J. Tušek


    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.

  20. Legal Deposit of Electronic Publications

    Directory of Open Access Journals (Sweden)

    Burcu Umut Zan


    Full Text Available The most important and basic role of the deposition studies, which are the greatest contributions to the knowledge sharing, is to gather the artistic and philosophical works of a country and provide them for the use of future researchers. However, since early deposition studies were limited with printed publications, they do not involve the electronic publication types appearing with the development of information technology. This stems from the fact that the electronic publications require procedures different from those of the printed publications in terms of deposition steps because of their structures. Today, in order to guarantee that all registered cultural products, which are mostly produced and used in the electronic environment could be fully collected, electronic publications should also be covered by and regulated under legal deposit. This study analyzes the deposition of electronic publications, within the framework of their storage and protection, being put in the use of the users as well as the common approaches to deposition practices in the world parallel to the developments in the information technology. The related situation in Turkey was also evaluated.

  1. A Radon Progeny Deposition Model (United States)

    Guiseppe, V. E.; Elliott, S. R.; Hime, A.; Rielage, K.; Westerdale, S.


    The next generation low-background detectors operating underground aim for unprecedented low levels of radioactive backgrounds. Although the radioactive decays of airborne radon (particularly 222Rn) 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 210Pb on sensitive locations of a detector. An understanding of the potential surface contamination from deposition will enable requirements of radon-reduced air and clean room environments for the assembly of low background experiments. It is known that there are a number of environmental factors that govern the deposition of progeny onto surfaces. However, existing models have not explored the impact of some environmental factors important for low background experiments. A test stand has been constructed to deposit radon progeny on various surfaces under a controlled environment in order to develop a deposition model. Results from this test stand and the resulting deposition model are presented.

  2. Depositional origin of snow sastrugi (United States)

    Leonard, K. C.; Tremblay, B.


    Sastrugi are wind-parallel elongated surface roughness features found on both land and sea ice. Simple models of sastrugi formation suggest that these features grow via deposition of windblown snow in the lee of an initial perturbation in surface topography, and subsequent erosion of the up-wind end of the bump. We present a mechanism for the creation of sastrugi nucleation sites: the initial surface perturbation. Modeling results of plumes of blowing snow moving at or above 15 meters per second (at the 10m reference level) show that when the snow surface is depleted of loose (erodible) snow, small amounts of deposition occur. Once formed, these irregularly spaced small deposits of snow (less than 0.1 cm over 1m2 or less) can persist and propagate.


    Energy Technology Data Exchange (ETDEWEB)

    Cem Sarica; Michael Volk


    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.

  4. Lateritic nickel deposits of Brazil (United States)

    de Oliveira, S. M. Barros; Trescases, J. J.; Melfi, A. José


    Many nickel deposits are known in Brazil, accounting for about 350 · 106 tons of ore with an average of 1.5% Ni. All are of the lateritic type. These deposits are scattered throughout the country, being rarer in the Northeastern Region and in the South, below 25 °S latitude. They are mainly associated with mafic-ultramafic massifs of large dimensions and ultramafic alkaline complexes, and occur in climatic regions of contrasting seasons. The weathering profile developed over the fresh rock consists, from bottom to top, of the following horizons: altered rock, coarse saprolite, argillaceous saprolite, ferruginous saprolite and lateritic overburden. The thickness of each horizon varies from one deposit to another, the whole profile generally exceeding 20 m. The saprolitic horizons with inherited minerals (serpentine, chlorite) or neoformed minerals (smectites) constitute the silicated nickel ore and are thicker were climatic conditions are drier; the ferruginous upper horizons made up of iron oxide-hydroxides are more developed in more humid regions. In Brazil, the silicated ore generally prevails over the oxidized ore. The main Ni-bearing minerals are serpentine, smectite, garnierite and goethite. The lateritic nickel deposits of Brazil may be correlated with two erosion surfaces, corresponding to the Sul Americano (Lower Tertiary) and Velhas (Upper Tertiary) levelling cycles. The degree of dismantling of the higher and more ancient surface and the consequent development of the Velhas Surface control the position of the nickel accumulation in the landscape. Thus, the deposits may be found either in the lowlands or in the highlands, where they are always covered by a silcrete layer. The alteration profiles in the Brazilian lateritic nickel deposits are broadly similar to those described elsewhere in the world. However, they present two characteristic features: the silicated ore prevails over the oxidized ore, and a silicified layer covers the profies developed on

  5. The role of transverse speed on deposition height and material efficiency in laser deposited titanium alloy

    CSIR Research Space (South Africa)

    Mahamood, RM


    Full Text Available deposition and reweighing after deposition. The substrate and the deposits were thoroughly cleaned using wire brush and acetone to remove unmelted powder particles from the surface of the substrate and the deposit. The height and width of the deposits were...

  6. 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....

  7. Nitrogen deposition and terrestrial biodiversity (United States)

    Christopher M. Clark; Yongfei Bai; William D. Bowman; Jane M. Cowles; Mark E. Fenn; Frank S. Gilliam; Gareth K. Phoenix; Ilyas Siddique; Carly J. Stevens; Harald U. Sverdrup; Heather L. Throop


    Nitrogen deposition, along with habitat losses and climate change, has been identified as a primary threat to biodiversity worldwide (Butchart et al., 2010; MEA, 2005; Sala et al., 2000). The source of this stressor to natural systems is generally twofold: burning of fossil fuels and the use of fertilizers in modern intensive agriculture. Each of these human...

  8. Grow Your Own Copper Deposit (United States)

    Corcoran, Timothy John


    Crystals are beautiful structures--yet they occur naturally in dirty and remote places. In the inquiry-based activity described here, students will enjoy the process of creating their own crystals and using microscopes to examine them. It demonstrates the process of mineral concentration and deposition. Upon completing this activity, students…

  9. Simple Chemical Vapor Deposition Experiment (United States)

    Pedersen, Henrik


    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…

  10. Fossil ascomycetes in Quaternary deposits

    NARCIS (Netherlands)

    van Geel, B.; Aptroot, A.


    Abstract: Remains of various ascomycetes, mainly ascospores, have been detected during palynological studies of lake sediments, peat deposits and samples from archaeological sites. Many taxa can be identified to genus or species level of extant taxa. Ascospore remains may sometimes give indications


    African Journals Online (AJOL)


    textural characteristics, organic matter contents, mineralogical ... such as the organic matter content and depositional environment of the .... laminated. 100. 10510 Shale. Light grey shale. 100. 10610 Shale. Medium grey shale. 100. 10640 Shale. Dark grey shale with termination. 100. 10680 Shale. Dark grey shale with.

  12. Electro-spark deposition technology

    Energy Technology Data Exchange (ETDEWEB)

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


    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.

  13. Constructing deposition chronologies for peat deposits using radiocarbon dating

    Directory of Open Access Journals (Sweden)

    N. Piotrowska


    Full Text Available Radiocarbon dating is one of the main methods used to establish peat chronologies. This article reviews the basis of the method and its application to dating of peat deposits. Important steps in the radiocarbon dating procedure are described, including selection and extraction of material (and fractions for dating, chemical and physical preparation of media suitable for measurements, measurements of 14C activity or concentration, calculations, calibration of results and age-depth modelling.

  14. Imaging Approaches for Contact Lens Deposition. (United States)

    Panthi, Shyam; Nichols, Jason J


    Deposition on contact lenses (CLs) starts quickly after their application to the ocular surface. Deposits may be composed of tear film components or other extraneous substances. These deposits have been related to various adverse conditions of the eye, leading to reduced biocompatibility between the CLs and the ocular surface. Analysis of these deposits is essential to better elucidate the relationship between these deposits and their adverse reactions so that better methods of increasing biocompatibility can be developed. Although methods such as enzymatic assays are available for quantitative analysis, they do not provide a complete picture of the deposition (e.g., lack of morphological details), and therefore, the use of imaging methods that can provide both qualitative and quantitative information about the deposits may be more preferable. Therefore, a search of the peer-reviewed literature that focused on imaging methods in the analysis of deposits on CLs was conducted. Various methods of imaging deposits in-vitro, in-vivo, or ex-vivo have been described along with the associated results. Imaging methods using fluorescence-based techniques and scanning electron microscopy appear to be the most frequently used methods. Some of the described methods not only provided morphologies but also identified the types of various deposits that were attached to the CLs. Various CL materials possessed different deposition morphologies and different quantities of the attached deposits. Further imaging studies performed in conjunction with other methods that could identify and quantify the deposits at a molecular level are recommended.

  15. High throughput semiconductor deposition system

    Energy Technology Data Exchange (ETDEWEB)

    Young, David L.; Ptak, Aaron Joseph; Kuech, Thomas F.; Schulte, Kevin; Simon, John D.


    A reactor for growing or depositing semiconductor films or devices. The reactor may be designed for inline production of III-V materials grown by hydride vapor phase epitaxy (HVPE). The operating principles of the HVPE reactor can be used to provide a completely or partially inline reactor for many different materials. An exemplary design of the reactor is shown in the attached drawings. In some instances, all or many of the pieces of the reactor formed of quartz, such as welded quartz tubing, while other reactors are made from metal with appropriate corrosion resistant coatings such as quartz or other materials, e.g., corrosion resistant material, or stainless steel tubing or pipes may be used with a corrosion resistant material useful with HVPE-type reactants and gases. Using HVPE in the reactor allows use of lower-cost precursors at higher deposition rates such as in the range of 1 to 5 .mu.m/minute.

  16. Chemical vapor deposition of sialon (United States)

    Landingham, R.L.; Casey, A.W.

    A laminated composite and a method for forming the composite by chemical vapor deposition are described. The composite includes a layer of sialon and a material to which the layer is bonded. The method includes the steps of exposing a surface of the material to an ammonia containing atmosphere; heating the surface to at least about 1200/sup 0/C; and impinging a gas containing N/sub 2/, SiCl/sub 4/, and AlCl/sub 3/ on the surface.

  17. Measuring coal deposits by radar (United States)

    Barr, T. A.


    Front-surface, local-oscillator radar directly compares frequency of signals reflected from front and back surfaces of coal deposits. Thickness is measured directly as frequency difference. Transmitter is frequency modulated, so thickness is computed directly from frequency difference. Because front and back reflections are detected in combination rather than separately, masking of comparatively weak back signal is less problem. Also system is not sensitive to extraneous reflections from targets between transmitting antenna and coal surface.

  18. 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...... 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.  ...

  19. Pele Plume Deposit on Io (United States)


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

  20. Complexing and hydrothermal ore deposition

    CERN Document Server

    Helgeson, Harold C


    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

  1. Particle Deposition onto Enclosure Surfaces (United States)


    from constant bombardment by surrounding gas molecules. Such irregular motions of pollen grains in water were first observed by the botanist Robert...mode" particles, when neither of the mechanism works effectively to cause particle deposition (Figure 3). With respect to particle composition ... analyses as well as the limitations associated with these models. 7.1 Homogeneous Turbulence Model Modeling efforts for studying particle

  2. Electro-spark deposition technology

    Energy Technology Data Exchange (ETDEWEB)

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


    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.

  3. Forming method of deposited film

    Energy Technology Data Exchange (ETDEWEB)

    Hirooka, Masaaki; Kanai, Masahiro; Han' na, Jun' ichi; Shimizu, Isamu


    This invention relates with a forming method of a functional deposited film which is useful for electronic devices such as semiconductor device, photosensitive device for electrophotography, etc. It enables to attain energy saving and film quality control at the same time, and large area deposited film can be obtained which has uniform physical properties. It also excels in productivity. In other words, a starting material which contains elements of Group II of the Periodic Table (Zn, Cd, Hg) and elements of Group VI (O, S, Se, Te) which are in the gaseous form, is contacted in a reaction vessel with gaseous halogen-based oxidizer to chemically form an excited precursor, from which a deposited film formed on a substrate. Halogenic oxidizer is chlorine and fluorine. Example of Group II-containing compound is Zn(CH/sub 3/)/sub 2/, and examples of Group II-containing compound are NO, H/sub 2/S, Se(C/sub 2/H/sub 5/)/sub 2/. Example of the substrate is Al, s/s, polyester, polyethylene, glass, etc.. (3 tabs)

  4. Federal Deposit Insurance Corporation (FDIC) Insured Banks (United States)

    Department of Homeland Security — The Summary of Deposits (SOD) is the annual survey of branch office deposits for all FDIC-insured institutions including insured U.S. branches of foreign banks. Data...

  5. CTD_DATABASE - Cascadia tsunami deposit database (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...

  6. CTS and CZTS for solar cells made by pulsed laser deposition and pulsed electron deposition

    DEFF Research Database (Denmark)

    Ettlinger, Rebecca Bolt

    This thesis concerns the deposition of thin films for solar cells using pulsed laser deposition (PLD) and pulsed electron deposition (PED). The aim was to deposit copper tin sulfide (CTS) and zinc sulfide (ZnS) by pulsed laser deposition to learn about these materials in relation to copper zinc tin......, which make them promising alternatives to the commercially successful solar cell material copper indium gallium diselenide (CIGS). Complementing our group's work on pulsed laser deposition of CZTS, we collaborated with IMEM-CNR in Parma, Italy, to deposit CZTS by pulsed electron deposition for the first...... of using pulsed electron deposition was to make CZTS at a low processing temperature, avoiding the 570 °C annealing step used for our pulsed laser deposited solar cells. Preliminary solar cells had an efficiency of 0.2 % with a 300 °C deposition step without annealing. Further process control is needed...

  7. Isotropic metal deposition technique for metamaterials fabrication

    DEFF Research Database (Denmark)

    Malureanu, Radu; Andryieuski, Andrei; Lavrinenko, Andrei


    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.......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....

  8. Innovations in marketing of deposit services


    Vasylieva, T. A.; I.V. Didenko


    The aim of the article is recent studies of global trends in marketing of innovative deposit services. The results of the analysis. Summing up the general, it should be noted that, according to our goal, we systematized the theoretical basis of innovation in marketing services and deposit rated their performance justified the specific marketing innovation support domestic banks in the deposit market. Conclusions and directions of further researches. Deposit market is an important resour...

  9. 75 FR 6348 - Deposit of Biological Materials (United States)


    ... Patent and Trademark Office Deposit of Biological Materials ACTION: Proposed collection; comment [email protected] . Include ``0651-0022 Deposit of Biological Materials comment'' in the subject line [email protected] . SUPPLEMENTARY INFORMATION: I. Abstract The deposit of biological materials as part of...

  10. Dry deposition of particles to ocean surfaces

    NARCIS (Netherlands)

    Larsen, S.E.; Edson, J.B.; Hummelshoj, P.; Jensen, N.O.; Leeuw, G. de; Mestayer, P.G.


    Dry deposition of atmospheric particles mainly depends on wind speed and particle diameter. The dry deposition velocity, Vd, is found to vary by a factor of 100-1,000 with diameter in a likely diameter range, adding uncertainty to deposition estimates, because the diameter distribution for many

  11. 31 CFR 29.334 - Deposit service. (United States)


    ... 31 Money and Finance: Treasury 1 2010-07-01 2010-07-01 false Deposit service. 29.334 Section 29... Satisfied by June 30, 1997 § 29.334 Deposit service. (a) Teachers Plan. (1) Periods of civilian service that... Benefit Payments under the Teachers Plan if the deposit for the service was paid in full to the Teachers...

  12. 37 CFR 1.25 - Deposit accounts. (United States)


    ... 37 Patents, Trademarks, and Copyrights 1 2010-07-01 2010-07-01 false Deposit accounts. 1.25... Deposit accounts. (a) For the convenience of attorneys, and the general public in paying any fees due, in ordering services offered by the Office, copies of records, etc., deposit accounts may be established in...

  13. 31 CFR 357.26 - Direct Deposit. (United States)


    ... 31 Money and Finance: Treasury 2 2010-07-01 2010-07-01 false Direct Deposit. 357.26 Section 357.26... Treasury Direct) § 357.26 Direct Deposit. (a) General. A payment by the Department with respect to a security shall be by direct deposit unless it is deemed necessary by the Department to make payment by...

  14. 78 FR 16472 - Deposit of Biological Materials (United States)


    ... 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...) or, (2) deposited in a suitable depository that has been recognized as an International Depositary...

  15. European wet deposition maps based on measurements

    NARCIS (Netherlands)

    Leeuwen EP van; Erisman JW; Draaijers GPJ; Potma CJM; Pul WAJ van; LLO


    To date, wet deposition maps on a European scale have been based on long-range transport model results. For most components wet deposition maps based on measurements are only available on national scales. Wet deposition maps of acidifying components and base cations based on measurements are needed

  16. 50 CFR 259.34 - Minimum and maximum deposits; maximum time to deposit. (United States)


    ... 50 Wildlife and Fisheries 7 2010-10-01 2010-10-01 false Minimum and maximum deposits; maximum time to deposit. 259.34 Section 259.34 Wildlife and Fisheries NATIONAL MARINE FISHERIES SERVICE, NATIONAL... Capital Construction Fund Agreement § 259.34 Minimum and maximum deposits; maximum time to deposit. (a...

  17. [Imaging findings of cristal deposit disorders]. (United States)

    Hirschmann, Anna; Studler, Ueli


    Cristal deposit disorders are characterised by cristal deposits in hyaline and fibrocartilage, in synovium, capsule, ligaments and tendons and periarticular soft tissue. Calciumpyrophosphatedihydrate (CPPD), hydroxyapatite (calcific tendinitis) and uric acid arthropathies are the most common cristal deposit diseases. Radiography is still the number one image modality for initial imaging and the identification of cristal-induced inflammatory arthropathies. Differentiation between the entities of cristal deposit arthropathies can be challenging. Clincial and radiological findings may overlap in different cristal deposit arthropathies, owing a certain diagnosis difficult.

  18. Cluster Implantation and Deposition Apparatus

    DEFF Research Database (Denmark)

    Hanif, Muhammad; Popok, Vladimir


    In the current report, a design and capabilities of a cluster implantation and deposition apparatus (CIDA) involving two different cluster sources are described. The clusters produced from gas precursors (Ar, N etc.) by PuCluS-2 can be used to study cluster ion implantation in order to develop...... contributions to the theory of cluster stopping in matter as well as for practical applications requiring ultra-shallow implantation and modification of surfaces on the nanoscale. Metal clusters from the magnetron cluster source are of interest for the production of optical sensors to detect specific biological...

  19. Metal deposition using seed layers (United States)

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


    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.

  20. Energetic deposition of thin metal films

    CERN Document Server

    Al-Busaidy, M S K


    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 ...

  1. Legal Deposit of Digital Materials

    Directory of Open Access Journals (Sweden)

    Erik Oltmans


    Full Text Available Digital publishing is causing a real paradigm shift for research institutions and publishers, as well as for libraries. As a consequence these institutions have to develop new policies, new business models and new infrastructures and techniques. A major problem is that, at the same rate at which our world is becoming digital, the digital information is threatened. New types of hardware, computer applications and file formats supersede each other, making our recorded digital information inaccessible in the long-term. In the past years libraries and archives have undertaken several actions and studies on digital preservation issues. For instance the Koninklijke Bibliotheek (KB has jointly with IBM developed a standard-based deposit system: Digital Information Archiving System ( DIAS. Using DIAS the KB realised in 2002 an electronic deposit (the e-Depot and signed archiving agreements with major science publishers for permanent keeping of their digital materials. In this paper I will discuss the fully operational e-Depot at the KB. I will focus on the data flow of processing the digital publications, and I will address the issue of digital preservation in detail.

  2. Area Selective Polymer Brush Deposition. (United States)

    Cummins, Cian; Shaw, Matthew T; Morris, Michael A


    Polymer brush films with chemical functionality to attach to site specific substrate areas are introduced for area selective deposition (ASD) application. It is demonstrated that polymer brushes with chemically defined end sites can be selectively bound to copper-specific regions of patterned copper/silica (Cu/SiO2 ) substrates. The process described overcomes various limitations of currently used technology including cost, complexity, and throughput, with potential implications for future electronic devices and nanomanufacturing. A comparative study of amine-terminated polystyrene and amine-terminated poly-2-vinyl pyridine polymer brushes (i.e., PS-NH2 and P2VP-NH2 ) with similar molecular weights display contrasting behavior on patterned Cu/SiO2 line features. Further, a thiol terminated poly-2-vinyl pyridine polymer brush (i.e., P2VP-SH) is investigated as a direct spin-on process to fabricate a metal oxide layer atop Cu areas only. The results presented here detail a novel methodology and open a new exciting process for ASD practices that can facilitate the precise deposition of dense metal, semiconductor, or dielectric films. We also discuss the applicability of polymer brushes to ASD uses going forward. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Salt deposition at particle contact points (United States)

    Nie, Xiaodong; Evitts, Richard W.; Besant, Robert W.; Kennell, Glyn F.


    Caking may occur when granular potash fertilizer with a moisture content greater than 0.25 % (w/w) undergoes drying. Since cake strength is proportional to the mass of crystal deposited per unit volume near contact points (and other factors) the modelling of mass deposition near contact points is important. The Young-Laplace equation for the air-salt-solution interface is used to determine the geometry of a 2-D planar saline film between two cubic potash particles. A 2-D theoretical model is developed and applied for ion diffusion and deposition near the contact point during drying. The numerical predictions of ion diffusion in an initially saturated salt illustrate the transient spatial distribution of new KCl deposits along the solid surfaces near the contact line. These results indicate the average salt deposition commences at the air-liquid-solid intersection, where the liquid film is thinnest, and moves toward the particle contact point with increasing area averaged KCl deposits, causing the formation of crystal deposits and bridges near contact points. It is concluded that the average salt deposit height increases inversely with distance from the contact point and decreases with initial contact angle of the contact region, but the deposition is nearly independent of the evaporation or drying rate near each contact region. Caking strength depends on, among other parameters, the amount of salt deposition near contact points.

  4. 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 depos...... koncentrationer af tungmetaller (Cr, Mn, Fe, Ni, Cu, Zn, As, Cd, og Pb) i 2001 adskiller sig ikke væsentligt fra det seneste år. Over de sidste ti år er der sket et fald i tungmetalniveauerne på mellem en faktor to og tre; størst for Pb og Cd....

  5. [Diagnosis of calcified deposits in soft tissues]. (United States)

    Wybier, M; Laredo, J D; Parlier, C; Champsaur, P


    Calcific deposit within soft tissues is frequently a clue for diagnosis. The radiological analysis of a calcific deposit within soft tissues includes the following aspects: the basic structure of the calcification, the grade of differentiation of the calcification, the site of the calcification, the number of calcific deposits, the shape of the calcification, the changes in the adjacent non-calcified soft tissues and in the adjacent bone, the course of the clinical signs, the course of the radiological abnormalities.

  6. 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: [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)


    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.

  7. Copper Deposits in Sedimentary and Volcanogenic Rocks (United States)

    Tourtelot, Elizabeth B.; Vine, James David


    Copper deposits occur in sedimentary and volcanogenic rocks within a wide variety of geologic environments where there may be little or no evidence of hydrothermal alteration. Some deposits may be hypogene and have a deep-seated source for the ore fluids, but because of rapid cooling and dilution during syngenetic deposition on the ocean floor, the resulting deposits are not associated with hydrothermal alteration. Many of these deposits are formed at or near major tectonic features on the Earth's crust, including plate boundaries, rift valleys, and island arcs. The resulting ore bodies may be stratabound and either massive or disseminated. Other deposits form in rocks deposited in shallow-marine, deltaic, and nonmarine environments by the movement and reaction of interstratal brines whose metal content is derived from buried sedimentary and volcanic rocks. Some of the world's largest copper deposits were probably formed in this manner. This process we regard as diagenetic, but some would regard it as syngenetic, if the ore metals are derived from disseminated metal in the host-rock sequence, and others would regard the process as epigenetic, if there is demonstrable evidence of ore cutting across bedding. Because the oxidation associated with diagenetic red beds releases copper to ground-water solutions, red rocks and copper deposits are commonly associated. However, the ultimate size, shape, and mineral zoning of a deposit result from local conditions at the site of deposition - a logjam in fluvial channel sandstone may result in an irregular tabular body of limited size; a petroleum-water interface in an oil pool may result in a copper deposit limited by the size and shape of the petroleum reservoir; a persistent thin bed of black shale may result in a copper deposit the size and shape of that single bed. The process of supergene enrichment has been largely overlooked in descriptions of copper deposits in sedimentary rocks. However, supergene processes may be

  8. Giant landslide deposits in northwest Argentina

    Energy Technology Data Exchange (ETDEWEB)

    Fauque, L.; Strecker, M.R.; Bloom, A.L.


    Giant Quaternary landslide deposits occur along mountain fronts in the structural transition zone between the high-angle reverse-fault-bounded Sierras Pampeanas and the low-angle thrust belt of the Sierras Subandinas. There are two modes of occurrence: (1) chaotic masses without distinct geometry, and (2) masses with distinct lobate geometry similar to glacial moraines. Type (1) deposits occur where the moving rock mass followed a narrow valley and blocked the drainage. Many of these caused subsequent formation of lakes and changed the sedimentation processes on pediments at the mountain fronts. In type (2) deposits, lateral and frontal ridges are up to 10 m higher than the interior parts; in some places pressure ridges within the lobes are well preserved. Type (2) deposits show reverse grading and were deposited on relatively smooth pediments or alluvial fans. The lobate geometry strongly suggests that type (2) deposits are a product of flowage and are debris stream or sturzstrom deposits (sense of Heim, 1932 and Hsu, 1975). All investigated deposits occur in areas of demonstrated Quaternary faulting and are interpreted as the result of tectonic movements, although structural inhomogeneities in the source area may have been a significant factor for some of the landslides. No datable materials have yet been found associated with the deposits.

  9. Hideout in steam generator tube deposits

    Energy Technology Data Exchange (ETDEWEB)

    Balakrishnan, P.V.; Franklin, K.J.; Turner, C.W


    Hideout in deposits on steam generator tubes was studied using tubes coated with magnetite. Hideout from sodium chloride solutions at 279 degrees C was followed using an on-line high-temperature conductivity probe, as well as by chemical analysis of solution samples from the autoclave in which the studies were done. Significant hideout was observed only at a heat flux greater than 200 kW/m{sup 2}, corresponding to a temperature drop greater than 2 degrees C across the deposits. The concentration factor resulting from the hideout increased highly non-linearly with the heat flux (varying as high as the fourth power of the heat flux). The decrease in the apparent concentration factor with increasing deposit thickness suggested that the pores in the deposit were occupied by a mixture of steam and water, which is consistent with the conclusion from the thermal conductivity measurements on deposits in a separate study. Analyses of the deposits after the hideout tests showed no evidence of any hidden-out solute species, probably due to the concentrations being very near the detection limits and to their escape from the deposit as the tests were being ended. This study showed that hideout in deposits may concentrate solutes in the steam generator bulk water by a factor as high as 2 x 10{sup 3}. Corrosion was evident under the deposit in some tests, with some chromium enrichment on the surface of the tube. Chromium enrichment usually indicates an acidic environment, but the mobility required of chromium to become incorporated into the thick magnetite deposit may indicate corrosion under an alkaline environment. An alkaline environment could result from preferential accumulation of sodium in the solution in the deposit during the hideout process. (author)

  10. Colloid Deposit Morphology and Clogging in Porous Media: Fundamental Insights Through Investigation of Deposit Fractal Dimension. (United States)

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


    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.

  11. Ultrafast deposition of silicon nitride and semiconductor silicon thin films by Hot Wire Chemical Vapor Deposition

    NARCIS (Netherlands)

    Schropp, R.E.I.; van der Werf, C.H.M.; Verlaan, V.; Rath, J.K.; Li, H. B. T.


    The technology of Hot Wire Chemical Vapor Deposition (HWCVD) or Catalytic Chemical Vapor Deposition (Cat-CVD) has made great progress during the last couple of years. This review discusses examples of significant progress. Specifically, silicon nitride deposition by HWCVD (HW-SiNx) is highlighted,

  12. Pulsed laser deposition in Twente: from research tool towards industrial deposition

    NARCIS (Netherlands)

    Blank, David H.A.; Dekkers, Jan M.; Rijnders, Augustinus J.H.M.


    After the discovery of the perovskite high Tc superconductors in 1986, a rare and almost unknown deposition technique attracted attention. Pulsed laser deposition (PLD), or laser ablation as it was called in the beginning, became popular because of the possibility to deposit complex materials, like

  13. Ammonia release method for depositing metal oxides

    Energy Technology Data Exchange (ETDEWEB)

    Silver, G.L.; Martin, F.S.


    A method of depositing metal oxides on substrates which is indifferent to the electrochemical properties of the substrates and which comprises forming ammine complexes containing metal ions and thereafter effecting removal of ammonia from the ammine complexes so as to permit slow precipitation and deposition of metal oxide on the substrates.

  14. Antireflection coatings on plastics deposited by plasma ...

    Indian Academy of Sciences (India)

    Home; Journals; Bulletin of Materials Science; Volume 31; Issue 4 ... The plasma polymerization process is more economical than ion-assisted physical vapour deposition processes as regards equipment and source materials and is more cost-effective, enabling the surface treatment and deposition of the ARC in the same ...

  15. Origin of bonebeds in Quaternary tank deposits (United States)

    Araújo-Júnior, Hermínio Ismael de; Porpino, Kleberson de Oliveira; Bergqvist, Lílian Paglarelli


    Tank deposits are an exceptional type of fossiliferous deposit and bear a remarkably fossil record of the Pleistocene megafauna of South America, particularly of Brazil. The taphonomy of vertebrate remains preserved in this type of environmental context was clearly driven by climate, similarly to most of the Quaternary continental fossil record. The formation of the vertebrates fossil record in tank deposits was influenced by the climate seasonality typical of arid climate. The taphonomic history of most tank deposits is a consequence of this seasonality and, as a result, the paleoecological data preserved in their fossil assemblages is reliable with respect to paleobiological and paleoenvironmental settings of the Quaternary ecosystems of the Brazilian Intertropical Region (BIR). Other tank deposits experienced an unusual taphonomic history that, besides climate, was affected by recurrent events of reworking produced by the depositional agents dominant in the surrounding alluvial plains. The conclusions obtained here concerning the main taphonomic settings and formative processes that characterize fossil vertebrate assemblages of tank deposits will help further studies aimed to recover information on the paleoecology of Quaternary fauna collected in such deposits by allowing a better understanding of their time and spatial resolutions and other potential biases.

  16. 33 CFR 20.605 - Depositions. (United States)


    ... questions and responses that were noted at the taking of the deposition and that would have been sustained if the witness had been personally present and testifying at a hearing, a deposition may be offered... taken by telephone conference call upon such terms, conditions, and arrangements as are prescribed in...

  17. Global reactive nitrogen deposition from lightning NOx

    NARCIS (Netherlands)

    Shepon, A.; Gildor, H.; Labrador, L.J.; Butler, T.; Ganzeveld, L.N.; Lawrence, M.G.


    We present results of the deposition of nitrogen compounds formed from lightning (LNO x ) using the global chemical transport Model of Atmospheric Transport and Chemistry¿Max Planck Institute for Chemistry version. The model indicates an approximately equal deposition of LNO x in both terrestrial

  18. Plant responses to insect egg deposition

    NARCIS (Netherlands)

    Hilker, M.; Fatouros, N.E.


    Plants can respond to insect egg deposition and thus resist attack by herbivorous insects from the beginning of the attack, egg deposition. We review ecological effects of plant responses to insect eggs and differentiate between egg-induced plant defenses that directly harm the eggs and indirect

  19. Deposition of contaminant aerosol on human skin

    DEFF Research Database (Denmark)

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


    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...

  20. 32 CFR 807.6 - Depositing payments. (United States)


    ... 32 National Defense 6 2010-07-01 2010-07-01 false Depositing payments. 807.6 Section 807.6 National Defense Department of Defense (Continued) DEPARTMENT OF THE AIR FORCE ADMINISTRATION SALE TO THE PUBLIC § 807.6 Depositing payments. Obtain instructions from the local Accounting and Finance Office...

  1. Goudafzettingen in Suriname (Gold deposits in Surinam)

    NARCIS (Netherlands)

    Brinck, J.W.


    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

  2. 37 CFR 2.208 - Deposit accounts. (United States)


    ... 37 Patents, Trademarks, and Copyrights 1 2010-07-01 2010-07-01 false Deposit accounts. 2.208 Section 2.208 Patents, Trademarks, and Copyrights UNITED STATES PATENT AND TRADEMARK OFFICE, DEPARTMENT OF COMMERCE RULES OF PRACTICE IN TRADEMARK CASES Fees and Payment of Money in Trademark Cases § 2.208 Deposit...

  3. Deposition and Investigation of Hydrophobic Coatings

    Directory of Open Access Journals (Sweden)

    Safonov Aleksey


    Full Text Available The fluoropolymer coatings of different morphologies are deposited by the HWCVD (Hot Wire CVD method. The effect of activator filament temperature on the structure of fluoropolymer coating is shown. The results of studying the hydrophobic fluoropolymer coatings with different structures, deposited by the HWCVD method, are presented.

  4. Adhesion Strength of Biomass Ash Deposits

    DEFF Research Database (Denmark)

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


    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 shutdown...

  5. Chemistry of deposit formation in distillate fuels

    Energy Technology Data Exchange (ETDEWEB)

    Hazlett, R.N.; Power, A.J.; Kelso, A.G.; Solly, R.K.


    The chemistry of deposit formation in distillate fuels was investigated at 65 and 80 C for time peroids equivalent to up to four years ambient storage. The chemical environment was varied by using different fuels, fuel blends, deposit promoters, and stabilzers. Blends of light cycle oil (LCO) in straight-run automotive distillate oil (ADO) were studied in most detail. A variety of carboxylic acids, a sulfonic acid, thiophenol, and caustic extract from LCO (primarily phenols) increased deposit formation, some very dramatically. For the carboxylic acids, a linear relationship was found between the hydrogen ion concentration calculated from pK/sub a/ values for water solutions and the amount of deposit formed. These acids enhanced deposit formation by catalytic action and are not incorporated into the deposit. Dodecylbenzenesulfonic acid and thiophenol were both strong deposit promoters, the latter deriving its major activity through partial conversion to benzenesulfonic acid during fuel stress. The phenols in the LCO caustic extract react via oxidative coupling to increase molecular size and develop low solubility in the fuel. A tertiary aliphatic amine stabilzer was effective for reducing the amounts of deposits from most stressed fuels and from all blends tested.

  6. The geomicrobiology of bauxite deposits

    Directory of Open Access Journals (Sweden)

    Xiluo Hao


    Full Text Available 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 plagioclase, orthoclase, and albite have been investigated as part of an analysis of microbial mediation. The paleoecology of such bauxitic microorganisms inhabiting continental (sub surfaces, revealed through geomicrobiological analysis, will add a further dimension to paleoclimatic and paleoenvironmental studies.

  7. A preliminary deposit model for lithium brines (United States)

    Bradley, Dwight; Munk, LeeAnn; Jochens, Hillary; Hynek, Scott; Labay, Keith A.


    This report is part of an effort by the U.S. Geological Survey to update existing mineral deposit models and to develop new ones. The global transition away from hydrocarbons toward energy alternatives increases demand for many scarce metals. Among these is lithium, a key component of lithium-ion batteries for electric and hybrid vehicles. Lithium brine deposits account for about three-fourths of the world’s lithium production. Updating an earlier deposit model, we emphasize geologic information that might directly or indirectly help in exploration for lithium brine deposits, or for assessing regions for mineral resource potential. Special attention is given to the best-known deposit in the world—Clayton Valley, Nevada, and to the giant Salar de Atacama, Chile.

  8. Tax evasion and Swiss bank deposits

    DEFF Research Database (Denmark)

    Johannesen, Niels


    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...... estimates the impact of the withholding tax on Swiss bank deposits held by EU residents while using non-EU residents who were not subject to the tax as a comparison group. We present evidence that Swiss bank deposits owned by EU residents declined by 30–40% relative to other Swiss bank deposits in two...... 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...

  9. Chemical vapor deposition coating for micromachines

    Energy Technology Data Exchange (ETDEWEB)



    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.

  10. Effects of deposition time in chemically deposited ZnS films in acidic solution

    Energy Technology Data Exchange (ETDEWEB)

    Haddad, H.; Chelouche, A., E-mail:; Talantikite, D.; Merzouk, H.; Boudjouan, F.; Djouadi, D.


    We report an experimental study on the synthesis and characterization of zinc sulfide (ZnS) single layer thin films deposited on glass substrates by chemical bath deposition technique in acidic solution. The effect of deposition time on the microstructure, surface morphology, optical absorption, transmittance, and photoluminescence (PL) was investigated by X-ray diffraction (XRD), scanning electronic microscopy (SEM), UV-Vis–NIR spectrophotometry and photoluminescence (PL) spectroscopy. The results showed that the samples exhibit wurtzite structure and their crystal quality is improved by increasing deposition time. The latter, was found to affect the morphology of the thin films as showed by SEM micrographs. The optical measurements revealed a high transparency in the visible range and a dependence of absorption edge and band gap on deposition time. The room temperature PL spectra indicated that all ZnS grown thin films emit a UV and blue light, while the band intensities are found to be dependent on deposition times. - Highlights: • Single layer ZnS thin films were deposited by CBD in acidic solution at 95 °C. • The effect of deposition time was investigated. • Coexistence of ZnS and ZnO hexagonal structures for time deposition below 2 h • Thicker ZnS films were achieved after monolayer deposition for 5 h. • The highest UV-blue emission observed in thin film deposited at 5 h.

  11. Chemical Vapor Deposition and Atomic Layer Deposition of Coatings for Mechanical Applications (United States)

    Doll, G. L.; Mensah, B. A.; Mohseni, H.; Scharf, T. W.


    Chemical vapor deposition (CVD) of films and coatings involves the chemical reaction of gases on or near a substrate surface. This deposition method can produce coatings with tightly controlled dimensions and novel structures. Furthermore, the non-line-of-sight-deposition capability of CVD facilitates the coating of complex-shaped mechanical components. Atomic layer deposition (ALD) is also a chemical gas phase thin film deposition technique, but unlike CVD, it utilizes “self-limiting” surface adsorption reactions (chemisorption) to control the thickness of deposited films. This article provides an overview of CVD and ALD, discusses some of their fundamental and practical aspects, and examines their advantages and limitations versus other vapor processing techniques such as physical vapor deposition in regard to coatings for mechanical applications. Finally, site-specific cross-sectional transmission electron microscopy inside the wear track of an ALD ZnO/ZrO2 8 bilayers nanolaminate coating determined the mechanisms that control the friction and wear.

  12. 31 CFR 344.4 - What are Time Deposit securities? (United States)


    ... 31 Money and Finance: Treasury 2 2010-07-01 2010-07-01 false What are Time Deposit securities? 344... LOCAL GOVERNMENT SERIES Time Deposit Securities § 344.4 What are Time Deposit securities? Time Deposit...? The issuer must fix the maturity periods for Time Deposit securities, which are issued as follows: (1...

  13. 50 CFR 270.16 - Deposit of funds. (United States)


    ... 50 Wildlife and Fisheries 7 2010-10-01 2010-10-01 false Deposit of funds. 270.16 Section 270.16... Deposit of funds. All funds collected or received by a Council under this section must be deposited in an... deposited in any interest-bearing account or certificate of deposit of a bank that is a member of the...

  14. Structural characterization of MAPLE deposited lipase biofilm (United States)

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


    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. Lateritic, supergene rare earth element (REE) deposits (United States)

    Cocker, Mark D.


    Intensive lateritic weathering of bedrock under tropical or sub-tropical climatic conditions can form a variety of secondary, supergene-type deposits. These secondary deposits may range in composition from aluminous bauxites to iron and niobium, and include rare earth elements (REE). Over 250 lateritic deposits of REE are currently known and many have been important sources of REE. In southeastern China, lateritic REE deposits, known as ion-adsorption type deposits, have been the world’s largest source of heavy REE (HREE). The lateritized upper parts of carbonatite intrusions are being investigated for REE in South America, Africa, Asia and Australia, with the Mt. Weld deposit in Australia being brought into production in late 2012. Lateritic REE deposits may be derived from a wide range of primary host rocks, but all have similar laterite and enrichment profiles, and are probably formed under similar climatic conditions. The weathering profile commonly consists of a depleted zone, an enriched zone, and a partially weathered zone which overlie the protolith. Lateritic weathering may commonly extend to depths of 30 to 60 m. REE are mobilized from the breakdown of primary REE-bearing minerals and redeposited in the enriched zone deeper in the weathering horizon as secondary minerals, as colloids, or adsorbed on other secondary minerals. Enrichment of REE may range from 3 to 10 times that of the source lithology; in some instances, enrichment may range up to 100 times.

  16. Adhesion Strength of Biomass Ash Deposits

    DEFF Research Database (Denmark)

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


    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...

  17. Rare earth element deposits in China (United States)

    Xie, Yu-Ling; Hou, Zeng-qian; Goldfarb, Richard J.; Guo, Xiang; Wang, Lei


    China is the world’s leading rare earth element (REE) producer and hosts a variety of deposit types. Carbonatite- related REE deposits, the most significant deposit type, include two giant deposits presently being mined in China, Bayan Obo and Maoniuping, the first and third largest deposits of this type in the world, respectively. The carbonatite-related deposits host the majority of China’s REE resource and are the primary supplier of the world’s light REE. The REE-bearing clay deposits, or ion adsorption-type deposits, are second in importance and are the main source in China for heavy REE resources. Other REE resources include those within monazite or xenotime placers, beach placers, alkaline granites, pegmatites, and hydrothermal veins, as well as some additional deposit types in which REE are recovered as by-products. Carbonatite-related REE deposits in China occur along craton margins, both in rifts (e.g., Bayan Obo) and in reactivated transpressional margins (e.g., Maoniuping). They comprise those along the northern, eastern, and southern margins of the North China block, and along the western margin of the Yangtze block. Major structural features along the craton margins provide first-order controls for REE-related Proterozoic to Cenozoic carbonatite alkaline complexes; these are emplaced in continental margin rifts or strike-slip faults. The ion adsorption-type REE deposits, mainly situated in the South China block, are genetically linked to the weathering of granite and, less commonly, volcanic rocks and lamprophyres. Indosinian (early Mesozoic) and Yanshanian (late Mesozoic) granites are the most important parent rocks for these REE deposits, although Caledonian (early Paleozoic) granites are also of local importance. The primary REE enrichment is hosted in various mineral phases in the igneous rocks and, during the weathering process, the REE are released and adsorbed by clay minerals in the weathering profile. Currently, these REE-rich clays are

  18. Deposition characteristics of titanium coating deposited on SiC fiber by cold-wall chemical vapor deposition

    Energy Technology Data Exchange (ETDEWEB)

    Luo, Xian, E-mail:; Wu, Shuai; Yang, Yan-qing; Jin, Na; Liu, Shuai; Huang, Bin


    The deposition characteristics of titanium coating on SiC fiber using TiCl{sub 4}-H{sub 2}-Ar gas mixture in a cold-wall chemical vapor deposition were studied by the combination of thermodynamic analysis and experimental studies. The thermodynamic analysis of the reactions in the TiCl{sub 4}-H{sub 2}-Ar system indicates that TiCl{sub 4} transforms to titanium as the following paths: TiCl{sub 4} → TiCl{sub 3} → Ti, or TiCl{sub 4} → TiCl{sub 3} → TiCl{sub 2} → Ti. The experimental results show that typical deposited coating contains two distinct layers: a TiC reaction layer close to SiC fiber and titanium coating which has an atomic percentage of titanium more than 70% and that of carbon lower than 30%. The results illustrate that a carbon diffusion barrier coating needs to be deposited if pure titanium is to be prepared. The deposition rate increases with the increase of temperature, but higher temperature has a negative effect on the surface uniformity of titanium coating. In addition, appropriate argon gas flow rate has a positive effect on smoothing the surface morphology of the coating. - Highlights: • Both thermodynamic analysis and experimental studies were adopted in this work. • The transformation paths of TiCl{sub 4} to Ti is: TiCl{sub 4} → TiCl{sub 3} → Ti, or TiCl{sub 4} → TiCl{sub 3} → TiCl{sub 2} → Ti. • Typical deposited Ti coating on SiC fiber contained two distinct layers. • Deposition temperature is important on deposition rate and morphologies. • Appropriate argon gas flow rate has a positive effect on smoothing of the coating.

  19. An Introduction to Atomic Layer Deposition (United States)

    Dwivedi, Vivek H.


    Atomic Layer Deposition has been instrumental in providing a deposition method for multiple space flight applications. It is well known that ALD is a cost effective nanoadditive-manufacturing technique that allows for the conformal coating of substrates with atomic control in a benign temperature and pressure environment. Through the introduction of paired precursor gases, thin films can be deposited on a myriad of substrates from flat surfaces to those with significant topography. By providing atomic layer control, where single layers of atoms can be deposited, the fabrication of metal transparent films, precise nano-laminates, and coatings of nano-channels, pores and particles is achievable. The feasibility of this technology for NASA line of business applications range from thermal systems, optics, sensors, to environmental protection. An overview of this technology will be presented.

  20. Tax Evasion and Swiss Bank Deposits

    DEFF Research Database (Denmark)

    Johannesen, Niels

    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.......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...

  1. ROE Wet Nitrate Deposition 2011-2013 (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...

  2. ROE Total Nitrogen Deposition 1989-1991 (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...

  3. ROE Total Nitrogen Deposition 2011-2013 (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...

  4. Rare earth element mines, deposits, and occurrences (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...

  5. 7 CFR 47.16 - Depositions. (United States)


    ... Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE MARKETING OF PERISHABLE AGRICULTURAL COMMODITIES RULES OF PRACTICE... which the deposition is to be conducted (telephone, audio-visual telecommunication, or by personal...

  6. Major mineral deposits of the world (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,...

  7. ROE Total Sulfur Deposition 1989-1991 (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...

  8. ROE Wet Nitrate Deposition 1989-1991 (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...

  9. Porphyry copper deposits of the world (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...

  10. NOAA/WDC Global Tsunami Deposits Database (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...

  11. ROE Wet Sulfate Deposition 2009-2011 (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...

  12. Antidunes: new insights on processes and deposits (United States)

    Leclair, Suzanne


    This talk presents :1) a brief review of the development of our understanding of antidune processes and deposits; 2) results from the author's current collaborative studies, and; 3) points out key issues to be addressed in future research on upper-regime bedforms and sedimentary structures. Antidunes deposits may be overlooked or incorrectly interpretated in the sedimentary record. In alongstream direction, their preserved sedimentary structures resemble dune trough-cross stratification while accros-stream sections show mostly planar beds. Antidune strata can be structureless, and hence similar to some chute-and-pool, or hydraulic-jumps deposits. Moreover, recognition of antidune stratification in nature may also be hampered by the spatial limitation of exposures compared to the scale of the formative bedforms. However, antidune signature presents internal distinctive stratal and textural features that were revealed by experimental investigation and observation in modern fluvial deposits. The main results come from the comparative image analysis of video records and photographs of sediment samples (sediment peels) from flume experiments with upper-stage, open-flow conditions. These results brough new insights on antidune migration processes and deposition /erosion sequences, allowing to revise the traditional model typically presented in texbooks. Differences do occur between deposition/erosion patterns of 'progresive' antidunes (not all antidunes break) and breaking antidunes, resulting in the (potential) preservation of spatially-limited strata with boundaries that define a sort of polygone within the overall deposits, and that can show 'clusters' of gravel (antidune signature may then be more apparent in sand-and-gravel sediment than in well-sorted sand). This specific sedimentary feature was obverved in modern deposits from a dryland river (where antidune can occur during flash floods). Otherwise, limited experimental data on submarine, super-critical , high

  13. Perovskite Thin Films via Atomic Layer Deposition

    KAUST Repository

    Sutherland, Brandon R.


    © 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. Deposit Insurance: A Strategy for Reform. (United States)


    issues related to the financial services industry is included at the end of this report. (See Related GAO Products.) In conducting this study we...hearings relating to deposit insur- ance programs and the financial services industry ; professional litera- ture concerned with deposit insurance, bank and...The topic of whether such a board might appropriately be given much broader powers to regulate the financial services industry was outside the scope of

  15. Selective Electroless Silver Deposition on Graphene Edges

    DEFF Research Database (Denmark)

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


    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...

  16. Evolution of ore deposits on terrestrial planets (United States)

    Burns, R. G.


    Ore deposits on terrestrial planets materialized after core formation, mantle evolution, crustal development, interactions of surface rocks with the hydrosphere and atmosphere, and, where life exists on a planet, the involvement of biological activity. Core formation removed most of the siderophilic and chalcophilic elements, leaving mantles depleted in many of the strategic and noble metals relative to their chondritic abundances. Basaltic magma derived from partial melting of the mantle transported to the surface several metals contained in immiscible silicate and sulfide melts. Magmatic ore deposits were formed during cooling, fractional crystallization and density stratification from the basaltic melts. Such ore deposits found in earth's Archean rocks were probably generated during early histories of all terrestrial planets and may be the only types of igneous ores on Mars. Where plate tectonic activity was prevalent on a terrestrial planet, temporal evolution of ore deposits took place. Repetitive episodes of subduction modified the chemical compositions of the crust and upper mantles, leading to porphyry copper and molybdenum ores in calc-alkaline igneous rocks and granite-hosted tin and tungsten deposits. Such plate tectonic-induced mineralization in relatively young igneous rocks on earth may also have produced hydrothermal ore deposits on Venus in addition to the massive sulfide and cumulate chromite ores associated with Venusian mafic igneous rock. Sedimentary ore deposits resulting from mechanical and chemical weathering in reducing atmospheres in Archean earth included placer deposits (e.g., uraninite, gold, pyrite ores). Chromite, ilmenite, and other dense unreactive minerals could also be present on channel floors and in valley networks on Mars, while banded iron formations might underlie the Martian northern plains regions. As oxygen evolved in earth's atmosphere, so too did oxide ores. By analogy, gossans above sulfide ores probably occur on Mars

  17. Sediment-Hosted Copper Deposits of the World: Deposit Models and Database (United States)

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


    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

  18. Litigation in Perinatal Care: The Deposition Process. (United States)

    Miller, Lisa A

    Litigation in perinatal nursing represents a disproportionate share of indemnity payouts and results in excessive psychological stress. Testimony at deposition or trial can be challenging for clinicians; little is taught in training or postgraduate education regarding litigation. Nurses, midwives, and physicians can effectively navigate the deposition process and prepare for trial testimony by understanding the plaintiff's goals, recognizing the role of documentation, and becoming familiar with various plaintiff's strategies including reptile theory. Knowledge of psychological concepts such as confirmation bias and cognitive dissonance may assist clinicians in responding to plaintiff's lines of questioning. Deposition preparation is crucial to the defense and requires active participation on the part of clinicians; it may include mock deposition or use of simulation laboratories. Common mistakes in deposition may be avoided with foresight and anticipatory planning by clinicians working closely with risk managers and defense attorneys. This article provides an overview of the deposition process, including the plaintiff's goals and common approaches, as well as the role of documentation and common errors of deponents.

  19. Impact of sludge deposition on biodiversity. (United States)

    Manzetti, Sergio; van der Spoel, David


    Sludge deposition in the environment is carried out in several countries. It encompasses the dispersion of treated or untreated sludge in forests, marsh lands, open waters as well as estuarine systems resulting in the gradual accumulation of toxins and persistent organic compounds in the environment. Studies on the life cycle of compounds from sludge deposition and the consequences of deposition are few. Most reports focus rather on treatment-methods and approaches, legislative aspects as well as analytical evaluations of the chemical profiles of sludge. This paper reviews recent as well as some older studies on sludge deposition in forests and other ecosystems. From the literature covered it can be concluded that sludge deposition induces two detrimental effects on the environment: (1) raising of the levels of persistent toxins in soil, vegetation and wild life and (2) slow and long-termed biodiversity-reduction through the fertilizing nutrient pollution operating on the vegetation. Since recent studies show that eutrophication of the environment is a major threat to global biodiversity supplying additional nutrients through sludge-based fertilization seems imprudent. Toxins that accumulate in the vegetation are transferred to feeding herbivores and their predators, resulting in a reduced long-term survival chance of exposed species. We briefly review current legislation for sludge deposition and suggest alternative routes to handling this difficult class of waste.

  20. Plasma deposited fluorinated films on porous membranes

    Energy Technology Data Exchange (ETDEWEB)

    Gancarz, Irena [Department of Polymer and Carbon Materials, Wrocław University of Technology, 50-370 Wrocław (Poland); Bryjak, Marek, E-mail: [Department of Polymer and Carbon Materials, Wrocław University of Technology, 50-370 Wrocław (Poland); Kujawski, Jan; Wolska, Joanna [Department of Polymer and Carbon Materials, Wrocław University of Technology, 50-370 Wrocław (Poland); Kujawa, Joanna; Kujawski, Wojciech [Nicolaus Copernicus University, Faculty of Chemistry, 7 Gagarina St., 87-100 Torun (Poland)


    75 KHz plasma was used to modify track etched poly(ethylene terephthalate) membranes and deposit on them flouropolymers. Two fluorine bearing monomers were used: perflourohexane and hexafluorobenzene. The modified surfaces were analyzed by means of attenuated total reflection infra-red spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy, atomic force microscopy and wettability. It was detected that hexaflourobenxene deposited to the larger extent than perflourohaxane did. The roughness of surfaces decreased when more fluoropolymer was deposited. The hydrophobic character of surface slightly disappeared during 20-days storage of hexaflourobenzene modified membrane. Perfluorohexane modified membrane did not change its character within 120 days after modification. It was expected that this phenomenon resulted from post-reactions of oxygen with radicals in polymer deposits. The obtained membranes could be used for membrane distillation of juices. - Highlights: • Plasma deposited hydrophobic layer of flouropolymers. • Deposition degree affects the surface properties. • Hydrohilization of surface due to reaction of oxygen with entrapped radicals. • Possibility to use modified porous membrane for water distillation and apple juice concentration.

  1. Stratiform chromite deposit model: Chapter E in Mineral deposit models for resource assessment (United States)

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


    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.

  2. Phanerozoic Rifting Phases And Mineral Deposits (United States)

    Hassaan, Mahmoud


    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

  3. Limitation of petrographic indices in depositional environmental interpretation of coal deposits (United States)

    Sahay, Vinay


    Organic petrology based petrographic indices (Tissue Preservation Index and Gelification Index) is a widely utilized tool in the study of depositional palaeoenvironment of coal. Evaluation of these petrographic indices suggests that, at present, utilize only vitrinite/huminite and inertinite macerals to interpret depositional environment of coal. Liptinite group macerals have important depositional environment implications, but liptinite macerals have not been taken into account in earlier petrographic indices (TPI and GI) formulations. This article examines the limitation of TPI and GI, and proposes improved TPI and GI indices, including the liptinite and inertinite macerals having depositional environment significance.

  4. Dry deposition models for radionuclides dispersed in air: a new approach for deposition velocity evaluation schema (United States)

    Giardina, M.; Buffa, P.; Cervone, A.; De Rosa, F.; Lombardo, C.; Casamirra, M.


    In the framework of a National Research Program funded by the Italian Minister of Economic Development, the Department of Energy, Information Engineering and Mathematical Models (DEIM) of Palermo University and ENEA Research Centre of Bologna, Italy are performing several research activities to study physical models and mathematical approaches aimed at investigating dry deposition mechanisms of radioactive pollutants. On the basis of such studies, a new approach to evaluate the dry deposition velocity for particles is proposed. Comparisons with some literature experimental data show that the proposed dry deposition scheme can capture the main phenomena involved in the dry deposition process successfully.

  5. Aerosol Deposition and Solar Panel Performance (United States)

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


    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.

  6. Investigating Dry Deposition of Ozone to Vegetation (United States)

    Silva, Sam J.; Heald, Colette L.


    Atmospheric ozone loss through dry deposition to vegetation is a critically important process for both air quality and ecosystem health. The majority of atmospheric chemistry models calculate dry deposition using a resistance-in-series parameterization by Wesely (1989), which is dependent on many environmental variables and lookup table values. The uncertainties contained within this parameterization have not been fully explored, ultimately challenging our ability to understand global scale biosphere-atmosphere interactions. In this work, we evaluate the GEOS-Chem model simulation of ozone dry deposition using a globally distributed suite of observations. We find that simulated daytime deposition velocities generally reproduce the magnitude of observations to within a factor of 1.4. When correctly accounting for differences in land class between the observations and model, these biases improve, most substantially over the grasses and shrubs land class. These biases do not impact the global ozone burden substantially; however, they do lead to local absolute changes of up to 4 ppbv and relative changes of 15% in summer surface concentrations. We use MERRA meteorology from 1979 to 2008 to assess that the interannual variability in simulated annual mean ozone dry deposition due to model input meteorology is small (generally less than 5% over vegetated surfaces). Sensitivity experiments indicate that the simulation is most sensitive to the stomatal and ground surface resistances, as well as leaf area index. To improve ozone dry deposition models, more measurements are necessary over rainforests and various crop types, alongside constraints on individual depositional pathways and other in-canopy ozone loss processes.

  7. Removal of atmospheric ethanol by wet deposition (United States)

    Felix, J. David; Willey, Joan D.; Thomas, Rachel K.; Mullaugh, Katherine M.; Avery, G. Brooks; Kieber, Robert J.; Mead, Ralph N.; Helms, John; Giubbina, Fernanda F.; Campos, M. Lucia A. M.; Cala, John


    The global wet deposition flux of ethanol is estimated to be 2.4 ± 1.6 Tg/yr with a conservative range of 0.2-4.6 Tg/yr based upon analyses of 219 wet deposition samples collected at 12 locations globally. This estimate calculated by using observed wet deposition ethanol concentrations is in agreement with previous models (1.4-5 Tg/yr) predicting the wet deposition sink using Henry's law coefficients and atmospheric ethanol concentrations. Wet deposition is estimated to remove between 6 and 17% of the total ethanol emitted to the atmosphere on an annual basis. The concentration of ethanol in marine rain (25 ± 6 nM) is an order of magnitude less than in the majority of terrestrial rains (345 ± 280 nM). Terrestrial rain samples collected in locations impacted by high local sources of biofuel usage and locations downwind from ethanol distilleries were an order of magnitude higher in ethanol concentration (3090 ± 448 nM) compared to rain collected in terrestrial locations not impacted by these sources. These results indicate that wet deposition of ethanol is heavily influenced by local sources. Results of this study are important because they suggest that as biofuel production and usage increase, the concentration of ethanol in the atmosphere will increase as well the wet deposition flux. Additional research constraining the sources, sinks, and atmospheric impacts of ethanol is necessary to better assist in the debate as whether or not to increase consumption of the alcohol as a biofuel.

  8. Cobalt—Styles of deposits and the search for primary deposits (United States)

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


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

  9. Origin and chemical composition of evaporite deposits (United States)

    Moore, George William


    A comparative study of marine evaporite deposits forming at the present time along the pacific coast of central Mexico and evaporite formations of Permian age in West Texas Basin was made in order to determine if the modern sediments provide a basis for understanding environmental conditions that existed during deposition of the older deposits. The field work was supplemented by investigations of artificial evaporite minerals precipitated in the laboratory and by study of the chemical composition of halite rock of different geologic ages. The environment of deposition of contemporaneous marine salt deposits in Mexico is acidic, is strongly reducing a few centimeters below the surface, and teems with microscopic life. Deposition of salt, unlike that of many other sediments, is not wholly a constructional phenomenon. Permanent deposits result only if a favorable balance exists between deposition in the dry season and dissolution in the wet season. Evaporite formations chosen for special study in the West Texas Basin are, in ascending order, the Castile, Salado, and Rustler formations, which have a combined thickness of 1200 meters. The Castile formation is largely composed of gypsum rock, the Salado, halite rock, and the Rustler, quartz and carbonate sandstone. The lower part of the Castile formation is bituminous and contains limestone laminae. The Castile and Rustler formations thicken to the south at the expense of salt of the intervening Salado formation. The clastic rocks of the Rustler formation are interpreted as the deposits of a series of barrier islands north of which halite rock of the Salado was deposited. The salt is believed to have formed in shallow water of uniform density that was mixed by the wind. Where water depth exceeded the depth of the wind mixing, density stratification developed, and gypsum was deposited. Dense water of high salinity below the density discontinuity was overlain by less dense, more normally saline water which was derived from

  10. 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:; 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)


    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.

  11. Applications of graphene electrophoretic deposition. A review. (United States)

    Chavez-Valdez, A; Shaffer, M S P; Boccaccini, A R


    This Review summarizes research progress employing electrophoretic deposition (EPD) to fabricate graphene and graphene-based nanostructures for a wide range of applications, including energy storage materials, field emission devices, supports for fuel cells, dye-sensitized solar cells, supercapacitors and sensors, among others. These carbonaceous nanomaterials can be dispersed in organic solvents, or more commonly in water, using a variety of techniques compatible with EPD. Most deposits are produced under constant voltage conditions with deposition time also playing an important role in determining the morphology of the resulting graphene structures. In addition to simple planar substrates, it has been shown that uniform graphene-based layers can be deposited on three-dimensional, porous, and even flexible substrates. In general, electrophoretically deposited graphene layers show excellent properties, e.g., high electrical conductivity, large surface area, good thermal stability, high optical transparency, and robust mechanical strength. EPD also enables the fabrication of functional composite materials, e.g., graphene combined with metallic nanoparticles, with other carbonaceous materials (e.g., carbon nanotubes) or polymers, leading to novel nanomaterials with enhanced optical and electrical properties. In summary, the analysis of the available literature reveals that EPD is a simple and convenient processing method for graphene and graphene-based materials, which is easy to apply and versatile. EPD has, therefore, a promising future for applications in the field of advanced nanomaterials, which depend on the reliable manipulation of graphene and graphene-containing systems.

  12. Stability of nanocrystalline electrochemically deposited layers

    DEFF Research Database (Denmark)

    Pantleon, Karen; Somers, Marcel A. J.


    The technological demand for manufacturing components with complex geometries of micrometer or sub-micrometer dimensions and ambitions for ongoing miniaturization have attracted particular attention to electrochemical deposition methods. Thin layers of electrochemically deposited metals and alloy...... 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.......The technological demand for manufacturing components with complex geometries of micrometer or sub-micrometer dimensions and ambitions for ongoing miniaturization have attracted particular attention to electrochemical deposition methods. Thin layers of electrochemically deposited metals and alloys...... have different microstructure and properties compared to bulk materials and the thermodynamic non-equilibrium state of as-deposited layers frequently results in changes of the microstructure as a function of time and/or temperature. The evolving microstructure affects the functionality and reliability...

  13. Electrophoretic deposition: a quantitative model for particle deposition and binder formation from alcohol-based suspensions

    NARCIS (Netherlands)

    Beer, De E.; Duval, J.F.L.; Meulenkamp, E.A.


    We investigated electrophoretic deposition from a suspension containing positively charged particles, isopropanol, water, and Mg(NO3)2, with the aim of describing the deposition rates of the particles and Mg(OH)2, which is formed due to chemical reactions at the electrode, in terms of quantitative

  14. Exploring the deposition of oxides on silicon for photovoltaic cells by pulsed laser deposition

    NARCIS (Netherlands)

    Doeswijk, L.M.; de Moor, Hugo H.C.; Rogalla, Horst; Blank, David H.A.


    Since most commercially available solar cells are still made from silicon, we are exploring the introduction of passivating qualities in oxides, with the potential to serve as an antireflection coating. Pulsed laser deposition (PLD) was used to deposit TiO2 and SrTiO3 coatings on silicon substrates.

  15. Controlling the resistivity gradient in chemical vapor deposition-deposited aluminum-doped zinc oxide

    NARCIS (Netherlands)

    Ponomarev, M. V.; Verheijen, M. A.; Keuning, W.; M. C. M. van de Sanden,; Creatore, M.


    Aluminum-doped ZnO (ZnO:Al) grown by chemical vapor deposition (CVD) generally exhibit a major drawback, i.e., a gradient in resistivity extending over a large range of film thickness. The present contribution addresses the plasma-enhanced CVD deposition of ZnO: Al layers by focusing on the control

  16. Tandem solar cells deposited using hot-wire chemical vapor deposition

    NARCIS (Netherlands)

    Veen, M.K. van


    In this thesis, the application of the hot-wire chemical vapor deposition (HWCVD) technique for the deposition of silicon thin films is described. The HWCVD technique is based on the dissociation of silicon-containing gasses at the catalytic surface of a hot filament. Advantages of this technique

  17. 31 CFR 344.7 - What are Demand Deposit securities? (United States)


    ... 31 Money and Finance: Treasury 2 2010-07-01 2010-07-01 false What are Demand Deposit securities... LOCAL GOVERNMENT SERIES Demand Deposit Securities § 344.7 What are Demand Deposit securities? Demand Deposit securities are one-day certificates of indebtedness that are automatically rolled over each day...

  18. 19 CFR 141.101 - Time of deposit. (United States)


    ... 19 Customs Duties 2 2010-04-01 2010-04-01 false Time of deposit. 141.101 Section 141.101 Customs... (CONTINUED) ENTRY OF MERCHANDISE Deposit of Estimated Duties § 141.101 Time of deposit. Estimated duties shall either be deposited with the Customs officer designated to receive the duties at the time of the...

  19. 25 CFR 163.17 - Deposit with bid. (United States)


    ... 25 Indians 1 2010-04-01 2010-04-01 false Deposit with bid. 163.17 Section 163.17 Indians BUREAU OF... and Operations § 163.17 Deposit with bid. (a) A deposit shall be made with each proposal for the purchase of Indian forest products. Such deposits shall be at least: (1) Ten (10) percent if the appraised...

  20. 37 CFR 1.807 - Viability of deposit. (United States)


    ... 37 Patents, Trademarks, and Copyrights 1 2010-07-01 2010-07-01 false Viability of deposit. 1.807... COMMERCE GENERAL RULES OF PRACTICE IN PATENT CASES Biotechnology Invention Disclosures Deposit of Biological Material § 1.807 Viability of deposit. (a) A deposit of biological material that is capable of...

  1. 37 CFR 1.806 - Term of deposit. (United States)


    ... 37 Patents, Trademarks, and Copyrights 1 2010-07-01 2010-07-01 false Term of deposit. 1.806... COMMERCE GENERAL RULES OF PRACTICE IN PATENT CASES Biotechnology Invention Disclosures Deposit of Biological Material § 1.806 Term of deposit. A deposit made before or during pendency of an application for...

  2. 5 CFR 831.2104 - Eligibility to make deposit. (United States)


    ... 5 Administrative Personnel 2 2010-01-01 2010-01-01 false Eligibility to make deposit. 831.2104... REGULATIONS (CONTINUED) RETIREMENT Deposits for Military Service § 831.2104 Eligibility to make deposit. The following individuals may make deposit for any full period of service performed before the separation on...

  3. 12 CFR 557.15 - Who owns a deposit account? (United States)


    ... 12 Banks and Banking 5 2010-01-01 2010-01-01 false Who owns a deposit account? 557.15 Section 557.15 Banks and Banking OFFICE OF THRIFT SUPERVISION, DEPARTMENT OF THE TREASURY DEPOSITS Deposit Activities of Federal Savings Associations § 557.15 Who owns a deposit account? You may treat the holder of...

  4. 12 CFR 969.2 - Deposits from members. (United States)


    ... 12 Banks and Banking 7 2010-01-01 2010-01-01 false Deposits from members. 969.2 Section 969.2 Banks and Banking FEDERAL HOUSING FINANCE BOARD FEDERAL HOME LOAN BANK LIABILITIES DEPOSITS § 969.2 Deposits from members. Banks may accept demand and time deposits from members, reserving the right to...

  5. 7 CFR 97.7 - Deposit of Voucher Specimen. (United States)


    ...) The application number assigned by the Office; (2) The crop kind, genus and species, and variety...) A statement that the deposit is capable of reproduction. (e) Replacement or supplement of deposit... replacement or supplemental deposit. Such deposits will be governed by the same considerations governing the...

  6. 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


    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.

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

    Directory of Open Access Journals (Sweden)

    Anuar Kassim


    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.

  8. Growth and properties of nanostructured titanium dioxide deposited by supersonic plasma jet deposition (United States)

    Dell'Orto, E. C.; Caldirola, S.; Sassella, A.; Morandi, V.; Riccardi, C.


    Titanium dioxide (TiO2) is a wide gap semiconductor suitable for many applications. In this work, TiO2 nanostructured thin films are deposited by a plasma assisted supersonic deposition technique on silicon and on conductive glass substrates. Optical Emission Spectroscopy (OES) is used to monitor plasma conditions and precursor dissociation reactions. The influence of deposition parameters on TiO2 structure, uniformity, grain size, and optical properties are investigated by atomic force microscopy (AFM), mechanical profilometer, scanning electron microscopy (SEM) and spectroscopic ellipsometry (SE). Experimental results show how employed technique allows obtaining uniform films, with a tunable deposition range. Grains size could be chosen varying precursor flux during the deposition process. Films nanostructure and porosity result to be affected by grains size. Substrate roughness results to affect film morphology.

  9. Atomic-layer deposition of silicon nitride

    CERN Document Server

    Yokoyama, S; Ooba, K


    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).

  10. Sol-gel deposited electrochromic coatings

    Energy Technology Data Exchange (ETDEWEB)

    Ozer, N.; Lampert, C.M.


    Electrochromic devices have increasing application in display devices, switchable mirrors and smart windows. A variety of vacuum deposition technologies have been used to make electrochromic devices. The sol- gel process offers an alternative approach to the synthesis of optical quality and low cost electrochromic device layers. This study summarizes the developments in sol-gel deposited electrochromic films. The sol-gel process involves the formation of oxide networks upon hydrolysis-condensation of alkoxide precursors. In this study we cover the sol-gel deposited oxides of WO[sub 3], V[sub 2]O[sub 5], TiO[sub 2], Nb[sub 2]O[sub 5], and NiO[sub x].

  11. Quenching Phase Separation by Vapor Deposition Polymerization (United States)

    Tao, Ran; Anthamatten, Mitchell


    Initiated chemical vapor deposition (iCVD) is a solventless, free radical technique predominately used to deposit homogeneous films of linear and crosslinked polymers directly from gas phase feeds. We report a template-free method to fabricate continuous-phase porous polymer films by simultaneous phase separation during iCVD. Phase separation during film growth is achieved by condensing an inert porogen, along with initiator, monomer, and crosslinker. When the vapor mixture transports to the cooled substrate, phase separation occurs along with polymerization and crosslinking, which quench the state of phase separation. The kinetics of spontaneously phase separation can be qualitatively understood on the basis of Cahn-Hilliard theory. A series of films were grown by varying monomer and porogen's degree of saturation. Deposited films were studied by electron microscopy and spectroscopic techniques.


    Bagby, W.C.; Pickthorn, W.J.; Goldfarb, R.; Hill, R.A.


    The Dee mine is a sediment-hosted, disseminated gold deposit in the Roberts Mountains allochthon of north central Nevada. Soil samples were collected from the C-horizon in undisturbed areas over the deposit in order to investigate the usefulness of soil geochemistry in identifying this type of deposit. Each sample was sieved to minus 80 mesh and analyzed quantitatively for Au, Ag, As, Sb, Hg, Tl and semi-quantitative data for an additional 31 elements. Rank sum analysis is successful for the Au, Ag, As, Sb, Hg, Tl suite, even though bedrock geology is disregarded. This method involves data transformation into a total element signature by ranking the data in ascending order and summing the element ranks for each sample. The rank sums are then divided into percentile groups and plotted. The rank sum plot for the Dee soils unequivocally identifies three of four known ore zones.

  13. Origin of emerald deposits of Brazil (United States)

    Giuliani, G.; Silva, L. J. H. D.; Couto, P.


    Precambrian emerald deposits of Brazil are found in a typical geologic setting with Archean basement and supracrustal, ultramafic, granitoid and rocks. Volcano-sedimentary series occur as imbricated structures or as bodies affected by complex folding and deformation. Emerald mineralization belongs to the classic biotite-schist deposit, which formed by the reaction of pegmatitic veins within ultrabasic rocks. At the same time, pegmatite-free emerald deposits linked to ductile shear zones are also known. Emerald formation is attributed to infiltrational metasomatic processes provoking a K-metasomatism of the ultrabasic rocks and also a desilication of the pegmatites. A new classification based on the geological setting, structural features, and ore paragenesis is proposed.

  14. Chemical vapor deposition of group IIIB metals (United States)

    Erbil, A.


    Coatings of Group IIIB metals and compounds thereof are formed by chemical vapor deposition, in which a heat decomposable organometallic compound of the formula given in the patent where M is a Group IIIB metal, such as lanthanum or yttrium and R is a lower alkyl or alkenyl radical containing from 2 to about 6 carbon atoms, with a heated substrate which is above the decomposition temperature of the organometallic compound. The pure metal is obtained when the compound of the formula 1 is the sole heat decomposable compound present and deposition is carried out under nonoxidizing conditions. Intermetallic compounds such as lanthanum telluride can be deposited from a lanthanum compound of formula 1 and a heat decomposable tellurium compound under nonoxidizing conditions.

  15. Sputtering. [as deposition technique in mechanical engineering (United States)

    Spalvins, T.


    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.

  16. Exploring and Monitoring of Methane Hydrate Deposits (United States)

    Sudac, D.; Obhođaš, J.; Nađ, K.; Valković, V.


    Relatively recently, in the last 20 years, it was discovered that methane hydrate (MH) deposits are globally distributed in the permafrost and oceans. Before 1965 when first deposits were discovered in nature, it was believed that MH can occur only in laboratory conditions or in vast parts of the Universe. Presently it is presumed that this solid crystalline compounds in which CH4 molecules occupies the water ice lattices (nominal chemical formula of MH is C4H62O23) can serve as an energy source favorably to the all of the world remaining conventional hydrocarbon sources. The worldwide estimates of MH deposits range from 2x1014 m3 to 3.053x1018 cubic meters. This uncertainty partly results from our limitations in geological understanding of the MH deposits, which is due to the relatively bad quality of data obtained by presently available seismic and electromagnetic techniques. Moreover, MH deposits can become vulnerable to climate changes, which were already occurring in geological past whit tremendous consequences for the global life on Earth. Thus, further development of advanced techniques is needed to enhance our abilities to better characterize, quantify and monitor the MH deposits. In the work presented 14 MeV neutrons and associated alpha particle imaging (API) where used to quantify the amount of MH in the sample. Samples were prepared from sea sediment, quartz sand and MH simulant. MH simulant with chemical formula C4H46O23 was made from sucrose (25 % by mass) and water. MH quantity was measured by measuring the carbon content in the sample [1-8].

  17. Enhanced Photocathodes for Astrophysics using Atomic Layer Deposition Techniques Deposition Techniques (United States)

    Siegmund, Oswald

    The objective of this program is to exploit the recent availability of atomic layer deposition techniques to provide a new generation of high performance photocathodes. We intend to work on the enhancement of photocathodes by atomic layer deposition, and on atomic layer deposited substrate structures, and assess their performance (gain, lifetime, stability, image fidelity) in microchannel plate based detectors. This would enable detection efficiency and bandpass improvements for microchannel plate based spaceflight detectors for imaging and spectroscopic instruments in small and large formats. Applications include the detection of soft X-ray, and UV through NUV. Recent work has achieved considerable success in development of borosilicate substrate microchannel plates functionalized by atomic layer deposited resistive and photoemissive materials. These could provide stable, compatible, substrates for high efficiency photocathodes, although very limited work has been done to date on this aspect. This development addresses detector technologies for SALSO, and impending proposals for a number of other NASA sub-orbital and satellite instruments. Results with borosilicate substrate microchannel plates functionalized by atomic layer deposited surface layers has been impressive, providing economical devices with long term stable gain and low background in formats up to 20 cm. Atomic layer deposition provides a surface layer that is smooth, clean, and chemically compatible with photocathode materials, and withstands high temperatures. The substrates can also be made with larger open area ratios, and the atomic layer deposition nanofabrication processes provides high secondary emission coefficients that will enhance photocathode efficiencies. Photocathodes (GaN, etc) deposited by MOCVD or MBE processes may also be deposited using atomic layer deposition, with potential advantages in layer structuring and selective area coverage and penetration over large areas.

  18. Identification of tsunami deposits using organic markers (United States)

    Bellanova, Piero; Schwarzbauer, Jan; Reicherter, Klaus; Jaffe, Bruce; Szczucinski, Witold


    Geochemical analyses of tsunami deposits are becoming standard and are used in almost every study. However, only inorganic proxies are typically studied. Recent studies that developed and broaden geochemical methods to investigate tsunami deposits (e.g., Szczucinski et al., 2016) and illustrate the importance of information from biomarker analyses (e.g., Shinozaki et al., 2015). These studies indicated that organic geochemistry can be used for the differentiation between marine and terrestrial matter, indicating a potential source of a deposit. Organic proxies also have the advantage of remaining longer in the sediment than inorganic proxies, which can be leached out by groundwater or rain. The 2011 Tohoku-oki tsunami inundated as much as 4.5 km inland and had run up heights of up to 40 m. Samples of sandy tsunami deposits from Sendai Plain, Samenoura Bay, and Oppa Bay (Japan) were collected and analyzed using gas chromatography-mass spectrometry (GC-MS) to search for natural compounds (biomarkers) and anthropogenic pollutants (anthropogenic markers). Natural compounds substances, such as fatty acids and n-alkanes, and anthropogenic compounds (e.g., polycyclic aromatic hydrocarbons and pesticides) were identified and quantified. Further, the two different compound types (natural vs. anthropogenic) were evaluated for their usefulness in identification of deposits from extreme flooding events. The analyzed chemical compounds and their diagenetic transformation products were distinctly different for the pre-tsunami, the tsunami and the thin post-tsunami eolian deposits. The preliminary results of this study point out the utility of organic indicators for the identification of extreme flooding events (like tsunamis), particularly for historic events. References Shinozaki, T., Fujino, S., Ikehara, M., Sawai, Y., Tamura, T., Goto, K., Sugawara, D., Abe, T., 2015. Marine biomarkers deposited on coastal land by the 2011Tohoku-oki tsunami. Natural Hazards 77

  19. Wax deposition in crude oil pipelines

    Energy Technology Data Exchange (ETDEWEB)

    Assuncao, Pablo Morelato; Rodrigues, Lorennzo Marrochi Nolding [Universidade Federal do Espirito Santo, Sao Mateus, ES (Brazil). Centro Universitario Norte do Espirito Santo. Engenharia de Petroleo; Romero, Mao Ilich [University of Wyoming, Laramie, WY (United States). Enhanced Oil Recovery Institute], e-mail:


    Crude oil is a complex mixture of hydrocarbons which consists of aromatics, paraffins, naphthenics, resins asphaltenes, etc. When the temperature of crude oil is reduced, the heavy components, like paraffin, will precipitate and deposit on the pipe internal wall in the form of a wax-oil gel. The gel deposit consists of wax crystals that trap some amount of oil. As the temperature gets cooler, more wax will precipitate and the thickness of the wax gel will increase, causing gradual solidification of the crude and eventually the oil stop moving inside the offshore pipeline. Crude oil may not be able to be re-mobilized during re-startup. The effective diameter will be reduced with wax deposition, resulting in several problems, for example, higher pressure drop which means additional pumping energy costs, poor oil quality, use of chemical components like precipitation inhibitors or flowing facilitators, equipment failure, risk of leakage, clogging of the ducts and process equipment. Wax deposition problems can become so sever that the whole pipeline can be completely blocked. It would cost millions of dollars to remediate an offshore pipeline that is blocked by wax. Wax solubility decreases drastically with decreasing temperature. At low temperatures, as encountered in deep water production, is easy to wax precipitate. The highest temperature below which the paraffins begins to precipitate as wax crystals is defined as wax appearance temperature (WAT). Deposition process is a complex free surface problem involving thermodynamics, fluid dynamics, mass and heat transfer. In this work, a numerical analysis of wax deposition by molecular diffusion and shear dispersion mechanisms in crude oil pipeline is studied. Diffusion flux of wax toward the wall is estimated by Fick's law of diffusion, in similar way the shear dispersion; wax concentration gradient at the solid-liquid interface is obtained by the volume fraction conservation equation; and since the wax deposition

  20. Treating paraffin deposits in producing oil wells

    Energy Technology Data Exchange (ETDEWEB)

    Noll, L.


    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.

  1. Acidic deposition: A review of biological effects (United States)

    Sparling, Donald W.; Hoffman, David J.; Rattner, Barnett A.; Burton, G. Allen; Cairns, John


    The problem of acidic deposition and its possible effects on habitats, organisms, materials, and human health has been recognized for centuries. Earliest accounts date to Cicero (about 100 B.C.), who linked structural damage to buildings and statues in Rome to the smokey rains of wood and charcoal burning.3 Based on estimated of human demographics and centers of population, problems caused by acidic deposition may extend back to 400 to 500 B.C., but were not fully manifested until the mid-1800s with the rise of the Industrial revolution. the term "acid rain" was apparently first coined by R.A. Smith in 1972.4

  2. Two-phase flow and calcite deposition

    Energy Technology Data Exchange (ETDEWEB)

    Gudmudsson, J.S.; Granadso-G, E.; Ortiz-R, J.


    The literature on two-phase flow in geothermal wells shows that the Orkiszewski method has found wide application in state-of-the-art wellbore simulators. Such a simulator was developed and then used for the problem of wellbore deposition of calcite in the Miravalles geothermal field in Costa Rica. The output of wells suffering calcite deposition decreases slowly at early time but rapidly at late time. The simulator was also used to estimate the deliverability curve for a large diameter well in the Svartsengi geothemal field in Iceland. The view is presented that more accurate wellbore simulators will make new reservoir engineering studies possible in geothermal fields.

  3. [Microbiologic studies of a spodumene deposit]. (United States)

    Karavaiko, G I; Avakian, Z A; Krutsko, V S; Mel'nikova, E O; Zhdanov, A V


    A wide spectrum of heterotrophic and autotrophic microorganisms was detected in the zones of decomposition of spodumene and bed rocks, pegmatites and shales, in the spodumene deposit. The following aerobic microorganisms which did not from spores predominated in the deposit: Arthrobacter globiformis, A. pascens, A. simplex, Nocardia globerula, Pseudomonas fluorescens, Ps. putida, Ps. testosteronii. The following specific bacterial groups were found: thionic, sulfate reducing, and nitrifying bacteria. Degradation of spodumene and bed rocks was found to occur in moist regions containing cracks; it was accompanied with a decrease in pH. A possible role of microorganisms in decomposition of spodumene as well as removal of elements is discussed.

  4. Chemical bath deposition of ZnO on functionalized self-assembled monolayers: selective deposition and control of deposit morphology. (United States)

    Shi, Zhiwei; Walker, Amy V


    We have developed a method by which to selectively and reproducibly deposit ZnO films on functionalized self-assembled monolayers (SAMs) using chemical bath deposition (CBD). The deposition bath is composed of zinc acetate and ethylenediamine. The deposition reaction pathways are shown to be similar to those observed for sulfides and selenides, even though ethylenediamine acts as both an oxygen source and a complexing agent. On -COOH terminated SAMs, Zn-carboxylate surface complexes act as nucleation sites for ion-by-ion growth, leading to the formation of adherent ZnO nanocrystallites. Cluster-by-cluster growth is also observed, which produces weakly adherent micrometer-sized ZnO crystallites. On -CH3 and -OH terminated SAMs, only micrometer-sized ZnO crystallites are observed because Zn(2+) does not complex with the SAM terminal group, preventing nucleation of the nanocrystalline phase. The application of either ultrasound ("sonication-assisted CBD") or stirring promotes ion-by-ion ZnO growth on -COOH terminated SAMs. Stirring produces smoother but less reproducible ZnO films than sonication-assisted CBD.

  5. Deposition kinetics of in-situ oxygen doped polysilicon film

    Directory of Open Access Journals (Sweden)

    Nalivaiko O. Yu.


    Full Text Available The influence of deposition conditions on composition of in-situ oxygen doped polysilicon films has been investigated. A kinetic model of adsorption-deposition process using concentrated silane and nitrous oxide has been developed. The range of optimal ratios of silane and nitrous oxide flows and deposition temperature, which provide the acceptable deposition rate, thickness uniformity, controllability of oxygen content in films and conformal deposition, have been determined.

  6. Estimates of cloud water deposition at mountain acid deposition program sites in the Appalachian Mountains

    Energy Technology Data Exchange (ETDEWEB)

    Ralph E. Baumgardner, Jr.; Selma S. Isil; Thomas F. Lavery; Christopher M. Rogers; Volker A. Mohnen [U.S. Environmental Protection Agency, Research Triangle Park, NC (USA)


    Cloud water deposition was estimated at three high-elevation sites in the Appalachian Mountains of the eastern United States (Whiteface Mountain, NY; Whitetop Mountain, VA; and Clingman s Dome, TN) from 1994 through 1999 as part of the Mountain Acid Deposition Program (MADPro). This paper provides a summary of cloud water chemistry, cloud liquid water content, cloud frequency, estimates of cloud water deposition of sulfur and nitrogen species, and estimates of total deposition of sulfur and nitrogen at these sites. Other cloud studies in the Appalachians and their comparison to MADPro are also summarized. Whiteface Mountain exhibited the lowest mean and median concentrations of sulfur and nitrogen ions in cloud water, while Clingman s Dome exhibited the highest mean and median concentrations. This geographic gradient is partly an effect of the different meteorological conditions experienced at northern versus southern sites in addition to the difference in pollution content of air masses reaching the sites. All sites measured seasonal cloud water deposition rates of SO{sub 4}{sup 2-} greater than 50 kg/ha and NO{sub 3}{sup -} rates of greater than 25 kg/ha. These high-elevation sites experienced additional deposition loading of SO{sub 4}{sup 2-} and NO{sub 3}{sup -} on the order of 6 20 times greater compared with lower elevation Clean Air Status and Trends Network (CASTNet) sites. Approximately 80 90% of this extra loading is from cloud deposition. 56 refs., 3 figs., 8 tabs., 1 app.

  7. 78 FR 13212 - Investment and Deposit Activities (United States)


    ... 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 regulation...). This final rule adds TIPS to the list of permissible investments for FCUs in part 703. TIPS will...

  8. 77 FR 59144 - Investment and Deposit Activities (United States)


    ... ADMINISTRATION 12 CFR Part 703 RIN 3133-AE06 Investment and Deposit Activities AGENCY: National Credit Union... to amend its investment regulation to allow federal credit unions (FCUs) to purchase Treasury... investments for FCUs in part 703. The Board believes TIPS will provide FCUs with an additional investment...

  9. 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)


    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.

  10. Electrospray deposition from fountain pen AFM probes

    NARCIS (Netherlands)

    Geerlings, J.; Sarajlic, Edin; Berenschot, Johan W.; Abelmann, Leon; Tas, Niels Roelof


    In this paper we present for the first time electrospraying from fountain pen probes. By using electrospray contactless deposition in an AFM setup becomes possible. Experiments on a dedicated setup were carried out as first step towards this goal. Spraying from 8 and 2 µm apertures was observed. For

  11. Metal bonding during sputter film deposition

    NARCIS (Netherlands)

    Shimatsu, T.; Shimatsu, T.; Mollema, R.H.; Monsma, D.J.; Keim, Enrico G.; Lodder, J.C.


    We studied the bonding between two flat Si substrates with thin metal films. The bonding was accomplished during thin film sputter deposition on contamination free surfaces of metal films. In this work we used Ti and Pt. Successful bonding of these metal films (each having a thickness of 10–20 nm)

  12. Towards understanding the genesis of PHOSPHORITE DEPOSITS

    Indian Academy of Sciences (India)

    Phosphorites Deposits · Dissolved phosphorus (P) in marine waters · Distribution of Phosphorus · Ancient / Quat.- Recent phosphorites · Scientific problems · Mechanisms proposed · PowerPoint Presentation · No Modern/Quat. analogs for ancient phosphorites - (Bentor, 1980; Cook, 1994) ?? Stromatolites · Slide 13.

  13. Sedimentology and depositional environments of the Upper ...

    African Journals Online (AJOL)


    trangressively later into shallow marine processes and periodically incised by fluvial channels (Fig.12). The older depositional sequence herein refer to as Unit I are characterized by well preserved, sharp based, non – imbricated to poorly imbricated, poorly sorted and matrix supported conglomerates suggesting debris flow ...

  14. Size dependent optical characteristics of chemically deposited ...

    Indian Academy of Sciences (India)

    Keywords. Thin film; ZnS; CBD method; optical properties. Abstract. ZnS thin films of different thicknesses were prepared by chemical bath deposition using thiourea and zinc acetate as S2- and Zn2+ source. The effect of film thickness on the optical and structural properties was studied. The optical absorption studies in the ...

  15. Federal Deposit Insurance Corporation Semiannual Regulatory Agenda (United States)


    ... institution closings and will help improve public confidence in the banking system. The rule eliminates the... Executive Compensation Criteria Into the Risk Assessment System: The FDIC is seeking comment on ways that the FDIC's risk-based deposit insurance assessment system (risk-based assessment system) could be...

  16. Automated semiconductor vacuum chemical vapor deposition facility (United States)


    A semiconductor vacuum chemical vapor deposition facility (totally automatic) was developed. Wafers arrived on an air track, automatically loaded into a furnace tube, processed, returned to the track, and sent on to the next operation. The entire process was controlled by a computer.

  17. Deposition dynamics of multi-solvent bioinks (United States)

    Kaneelil, Paul; Pack, Min; Cui, Chunxiao; Han, Li-Hsin; Sun, Ying


    Inkjet printing cellular scaffolds using bioinks is gaining popularity due to the advancement of printing technology as well as the growing demands of regenerative medicine. Numerous studies have been conducted on printing scaffolds of biomimetic structures that support the cell production of human tissues. However, the underlying physics of the deposition dynamics of bioinks remains elusive. Of particular interest is the unclear deposition dynamics of multi-solvent bioinks, which is often used to tune the micro-architecture formation. Here we systematically studied the effects of jetting frequency, solvent properties, substrate wettability, and temperature on the three-dimensional deposition patterns of bioinks made of Methacrylated Gelatin and Carboxylated Gelatin. The microflows inside the inkjet-printed picolitre drops were visualized using fluorescence tracer particles to decipher the complex processes of multi-solvent evaporation and solute self-assembly. The evolution of droplet shape was observed using interferometry. With the integrated techniques, the interplay of solvent evaporation, biopolymer deposition, and multi-drop interactions were directly observed for various ink and substrate properties, and printing conditions. Such knowledge enables the design and fabrication of a variety of tissue engineering scaffolds for potential use in regenerative medicine.

  18. Depositional environment and provenance of Middle Siwalik ...

    Indian Academy of Sciences (India)

    the Munster Basin, Ireland; Sedimentology 37 685–712. Maizels J 1993 Lithofacies variations within sandur deposits: The role of runoff regime, flow dynamics and sediment supply characteristics; Sedim. Geol. 85 299–325. Marshak S and Mitra G 1988 Basic Methods of Structural. Geology; Englewood Cliffs (New Jersey: ...

  19. sedimentology, depositional environments and basin evolution

    African Journals Online (AJOL)

    Preferred Customer

    subsurface geology, geochemical characteristics and reserve estimation of the coal and oil shale deposits of Delbi-Moye Basin. AMOCO (1988). Shigute Geleta ..... as barriers to river flows either as a constraint on lateral migration or by damming the flow water to form lakes (Alexander and Leeder, 1987). The depocenter of ...

  20. Nanostructured Antibacterial Silver Deposited on Polypropylene Nonwovens (United States)

    Hong-Bo, Wang; Jin-Yan, Wang; Qu-Fu, Wei; Jian-Han, Hong; Xiao-Yan, Zhao

    Nanostructured silver films were deposited on polypropylene (PP) nonwovens by RF magnetron sputter coating to obtain the antibacterial properties. Shake flask test was used to evaluate the antibacterial properties of the materials. Atomic force microscope (AFM) was utilized to observe the surface morphology. Energy-dispersive X-ray (EDX) was also employed to analyze the surface elemental compositions. The antibacterial results indicated that the prolonged deposition time led to a significant improvement in antibacterial effect, and sputtering power and argon pressure did not show obvious effect on antibacterial performance. It is believed that the total amount of silver ions released from the silver coating was increased as the deposition time increased. AFM images and quantitative analysis of EDX, respectively revealed that increase in deposition time led to the increased coverage of silver film and the increased silver weight percentage per unit surface, which provided evidences for the increased release rate of silver ions from the coating. Moreover, it was found that the optimum silver coating thickness was about 3 nm, taking antibacterial effect and cost of production into account.

  1. 40 CFR 1610.4 - Deposition Transcripts. (United States)


    ... 40 Protection of Environment 32 2010-07-01 2010-07-01 false Deposition Transcripts. 1610.4 Section 1610.4 Protection of Environment CHEMICAL SAFETY AND HAZARD INVESTIGATION BOARD ADMINISTRATIVE... to appear during a Board investigation, shall be recorded solely by an official reporter designated...

  2. Depositing Materials on the Micro- and Nanoscale

    DEFF Research Database (Denmark)

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


    on sequential introduction of precursor pulses with intermediate purging steps. The process proceeds by specific surface ligand-exchange reactions and this leads to layer-by-layer growth control. No other thin film deposition technique can approach the conformity achieved by ALD on high aspect ratio structures...

  3. Local plasma deposition on polymer components

    NARCIS (Netherlands)

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


    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)

  4. Reservoir characteristics and palaeo depositional environment of ...

    African Journals Online (AJOL)

    The Niger Delta is a prolific hydrocarbon producing belt in the southern Nigeria sedimentary basin on the continental margin of the Gulf of Guinea. This study used well log suites to delineate the hydrocarbon reservoirs, depositional environments and lithostratigraphy of the Duski Field, Onshore Niger Delta, Nigeria.

  5. Depositional environment and provenance of Middle Siwalik ...

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Earth System Science; Volume 121; Issue 1. Depositional environment and ... These oscillations are probably due to a combination of foreland-ward movement of Himalayan thrusts, climatic variations and mountain-ward shift of fanapex due to erosion. The Middle Siwalik sediments were derived ...

  6. Contaminant transport at a waste residue deposit

    DEFF Research Database (Denmark)

    Engesgaard, Peter Knudegaard; Traberg, Rikke


    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...

  7. Deposition kinetics of nanocolloidal gold particles

    NARCIS (Netherlands)

    Brouwer, E.A.M.; Kooij, Ernst S.; Hakbijl, Mark; Wormeester, Herbert; Poelsema, Bene


    The deposition kinetics of the irreversible adsorption of citrate-stabilized, nanocolloidal gold particles on Si/SiO2 surfaces, derivatized with (aminopropyl)triethoxysilane (APTES), is investigated in situ using single wavelength optical reflectometry. A well-defined flow of colloids towards the

  8. 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


    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.

  9. Chronic nitrogen deposition influences the chemical dynamics ... (United States)

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

  10. Efficient Phosphorescent OLEDS Based on Vacuum Deposition ...

    African Journals Online (AJOL)

    Thereby, we demonstrate high-efficiency organic light-emitting diodes by incorporating a double emission layer {i.e. both doped with the green phosphorescent dye tris(phenylpyridine)iridium [Ir(ppy)3]} into p-i-n-type device structure based on vacuum deposition technology. The intrinsic and doped transports layers are ...

  11. 28 CFR 68.22 - Depositions. (United States)


    ... 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 parties...

  12. Deposition of biopolymer films on micromechanical sensors

    DEFF Research Database (Denmark)

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


    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...

  13. Effects of Acid Deposition on Wood (United States)

    Mark Knaebe


    Since acid deposition increases the rate of deterioration of unpainted wood, it can also affect the performance of paint applied to this weathered wood. In tests conducted near Madison, Wisconsin, smooth-planed wood was allowed to weather before painting. Exposure for as little as 2 weeks shortened the service life of the subsequently applied paint. The paint bond was...

  14. Deposition of grids on plastic detectors

    CERN Document Server

    Birabeau, J P; Mendola, Onofrio


    In order to facilitate the locating of tracks of charged particles in cellulose-nitrate and polycarbonate (Makrofol, Lexan) foils, a method has been developed for the photo-deposition of translucent coordinate grids on these materials. The grids are resistant to the strongly caustic solutions used in developing tracks in plastic foils. (9 refs) .

  15. Deposition of nitrogen into the North Sea

    DEFF Research Database (Denmark)

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


    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...

  16. 31 CFR 223.4 - Deposits. (United States)


    ... 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 STATES...

  17. Templated Chemically Deposited Semiconductor Optical Fiber Materials (United States)

    Sparks, Justin R.; Sazio, Pier J. A.; Gopalan, Venkatraman; Badding, John V.


    Chemical deposition is a powerful technology for fabrication of planar microelectronics. Optical fibers are the dominant platform for telecommunications, and devices such as fiber lasers are forming the basis for new industries. High-pressure chemical vapor deposition (HPCVD) allows for conformal layers and void-free wires of precisely doped crystalline unary and compound semiconductors inside the micro-to-nanoscale-diameter pores of microstructured optical fibers (MOFs). Drawing the fibers to serve as templates into which these semiconductor structures can be fabricated allows for geometric design flexibility that is difficult to achieve with planar fabrication. Seamless coupling of semiconductor optoelectronic and photonic devices with existing fiber infrastructure thus becomes possible, facilitating all-fiber technological approaches. The deposition techniques also allow for a wider range of semiconductor materials compositions to be exploited than is possible by means of preform drawing. Gigahertz bandwidth junction-based fiber devices can be fabricated from doped crystalline semiconductors, for example. Deposition of amorphous hydrogenated silicon, which cannot be drawn, allows for the exploitation of strong nonlinear optical function in fibers. Finally, crystalline compound semiconductor fiber cores hold promise for high-power infrared light-guiding fiber devices and subwavelength-resolution, large-area infrared imaging.

  18. 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.


    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

  19. 14 CFR 13.125 - Depositions. (United States)


    ... Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION PROCEDURAL RULES INVESTIGATIVE AND ENFORCEMENT PROCEDURES Formal Fact-Finding Investigation Under an Order of Investigation § 13... Presiding Officer with reasonable notice to the party under investigation. Such depositions shall be taken...

  20. Micromorphology of modern tills in southwestern Spitsbergen – insights into depositional and post-depositional processes

    Directory of Open Access Journals (Sweden)

    Skolasińska Katarzyna


    Full Text Available Textural properties and microstructures are commonly used properties in the analysis of Pleistocene and older glacial deposits. However, contemporary glacial deposits are seldom studied, particularly in the context of post-depositional changes. This paper presents the results of a micromorphological study of recently deposited tills in the marginal zones of Hansbreen and Torellbreen, glaciers in southwestern Spitsbergen. The main objectives of this study were to compare modern tills deposited in subglacial and supraglacial conditions, as well as tills that were freshly released from ice with those laid down several decades ago. The investigated tills are primarily composed of large clasts of metamorphic rocks and represent coarse-grained, matrix-supported diamictons. The tills reveal several characteristic features for ductile (e.g. turbate structures and brittle (e.g. lineations, microshears deformations, which have been considered to be indicative of subglacial conditions. In supraglacial tills, the same structures are common as in the subglacial deposits, which points to the preservation of the primary features, though the sediment was transferred up to the glacier surface due to basal ice layer deformation and redeposited as slumps, or to formation of similar structures due to short-distance sediment re-deposition by mass flows. This study revealed that it might not be possible to distinguish subglacial and supraglacial tills on the basis of micromorphology if the latter are derived from a subglacial position. The only noted difference was the presence of iron oxide cementation zones and carbonate dissolution features in supraglacial tills. These features were found in tills that were deposited at least a few years ago and are interpreted to be induced by early post-depositional processes involving porewater/sediment interactions.

  1. Uranium deposits of the world. Europe

    Energy Technology Data Exchange (ETDEWEB)

    Dahlkamp, Franz J.


    Uranium Deposits of the World, in three volumes, comprises an unprecedented compilation of data and descriptions of the uranium regions in Asia, USA, Latin America and Europe structured by countries. With this third, the Europe volume, Uranium Deposits of the World presents the most extensive data collection of the set. It covers about 140 uranium regions in more than 20 European countries with nearly 1000 mentioned uranium deposits. Each country and region receives an analytical overview followed by the geologically- and economically-relevant synopsis of the individual regions and fields. The presentations are structured in three major sections: (a) location and magnitude of uranium regions, districts, and deposits, (b) principal features of regions and districts, and (c) detailed characteristics of selected ore fields and deposits. This includes sections on geology, alteration, mineralization, shape and dimensions of deposits, isotopes data, ore control and recognition criteria, and metallogenesis. Beside the main European uranium regions, for example in the Czech Republic, Eastern Germany, France, the Iberian Peninsula or Ukraine, also small regions an districts to the point of singular occurrences of interest are considered. This by far the most comprehensive presentation of European uranium geology and mining would not be possible without the author's access to extensive information covering the countries of the former Eastern Bloc states, which was partly not previously available. Abundantly illustrated with information-laden maps and charts throughout, this reference work is an indispensable tool for geologists, mining companies, government agencies, and others with an interest in European key natural resources. A great help for the reader's orientation are the substantial bibliography of uranium-related publications and the indices, latter containing about 3900 entries in the geographical part alone. The three volumes of Uranium Deposits of the

  2. Transmission electron microscopy studies of YBCO coated conductor deposited using multiple-stage chemical vapor deposition

    Energy Technology Data Exchange (ETDEWEB)

    Sasaki, H. [Japan Fine Ceramics Center, Material Research and Development Laboratory, 2-4-1, Mutsuno, Atsuta-ku, Nagoya, Aichi 456-8587 (Japan)]. E-mail:; Kato, T. [Japan Fine Ceramics Center, Material Research and Development Laboratory, 2-4-1, Mutsuno, Atsuta-ku, Nagoya, Aichi 456-8587 (Japan); Sasaki, Y. [Japan Fine Ceramics Center, Material Research and Development Laboratory, 2-4-1, Mutsuno, Atsuta-ku, Nagoya, Aichi 456-8587 (Japan); Hirayama, T. [Japan Fine Ceramics Center, Material Research and Development Laboratory, 2-4-1, Mutsuno, Atsuta-ku, Nagoya, Aichi 456-8587 (Japan); Kashima, N. [Electric Power Research and Development Center, Chubu Electric Power Co., Inc., 20-1, Kitasekiyama, Ohdaka-cho, Midori-ku, Nagoya, Aichi 459-8522 (Japan); Nagaya, S. [Electric Power Research and Development Center, Chubu Electric Power Co., Inc., 20-1, Kitasekiyama, Ohdaka-cho, Midori-ku, Nagoya, Aichi 459-8522 (Japan); Izumi, T. [Superconductivity Research Center, 1-10-13, Shinonome, Koto-ku, Tokyo 135-0062 (Japan); Shiohara, Y. [Superconductivity Research Center, 1-10-13, Shinonome, Koto-ku, Tokyo 135-0062 (Japan)


    A YBCO film was deposited on Hastelloy tape with highly oriented CeO{sub 2}/Gd{sub 2}Zr{sub 2}O{sub 7} multilayer using multiple-stage chemical vapor deposition. The microstructures of the YBCO coated conductor were examined in detail using transmission electron microscopy. Analysis indicated a YBCO film about 1 {mu}m thick was deposited and consisted mainly of c-axis oriented grains. However, a-axis oriented grains were also observed in the YBCO film, and these a-axis oriented grains grew larger with increasing thickness of the YBCO film.

  3. 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


    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

  4. Emission reductions to meet deposition criteria (United States)

    Smith, F. B.

    The paper assumes Governments are willing and able to reduce national emissions of pollution to protect the environment. Sulphur dioxide is examined as an important example. Although not necessarily true at the present time, it further assumes: (i) that the cost of reducing these emissions from different industries (and other source types) are known, and that these costs include the secondary consequences of emission control (for example, possible resulting unemployment); (ii) that maximum deposition criteria ( mdc) have been established on some appropriate grid (above which undesirable environmental damage will occur) and that in some gridsquares these mdc are currently being exceeded; and (iii) that priorities for reducing the deposition may be ascribed for each gridsquare. The highest priority may reflect concern over excessive levels of heavy metals in drinking water drawn from wells used by remote homesteads, for example. Gridsquares where more gradual, and hopefully reversible, damage is taking place would be given a rather lower priority. The paper seeks to establish maximum levels of emission in each gridsquare which will result in depositions nowhere exceeding the mdc (on the scale of a gridsquare). It also offers a means of selecting an optimum staged reduction strategy whereby emissions are reduced gradually towards the ultimate maximum levels, and at each stage of the reduction, gives the maximum benefit for the capital outlay consistent with the priorities and costs outlined above. The paper utilizes a very simple analytical model of the deposition field resulting from a single emission. The model is tuned to give the best comparison with the 1985 sulphur deposition field obtained using the much more complex EMEP MSC-W Lagrangian model used operationally for acid-rain analyses in Europe.

  5. The Nopal 1 Uranium Deposit: an Overview (United States)

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


    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.

  6. Geomorphic Characteristics of Lofted Turbidity Current Deposits (United States)

    Steel, E.; Buttles, J. L.; Simms, A.; Mohrig, D. C.


    Hyperpycnal flows are river-derived turbidity currents, which - in the marine realm - commonly contain interstitial fluid that is fresher and therefore less dense than ambient fluid. These flows travel along the seabed surface due to their high suspended sediment concentrations, and their fate depends heavily on the balance between factors that increase bulk flow density, e.g. entrainment of sediment or ambient water, and those that decrease bulk flow density, e.g. deposition of suspended sediment. If suspended sediment is rapidly deposited from the flow, bulk flow density and flow velocity will decrease until it reaches a point of equal density to the ambient fluid through which it is travelling. Once this point is reached, the flow can begin to rise to the water surface or to a depth of neutral buoyancy in a process known as lofting. We ran 21 experimental turbidity currents with varying bulk flow and interstitial fluid densities, across three different basin geometries, in order to characterize the effect on deposit geometry. Our findings show that lofted turbidity currents are width-limited and generate narrower, more elongate deposits than bed-attached flows. We also show that steeper ramp gradients push the lofting point farther out into the basin. We show the effect of variations in bulk flow density, suspended sediment concentration, and fluid density on overall deposit geometry and flow run-out distances. Most importantly, the use of a 3-dimensional experimental tank allows for the first detailed analysis of the lofting process and its effects on length-to-width ratios of turbidite lobes.

  7. Ash contents of Costa Rican peat deposits

    Energy Technology Data Exchange (ETDEWEB)

    Raymond, R. Jr.; Cohen, A.D.; Bish, D.L.


    Fourteen sites within 6 Costa Rican peat localities were sampled using MacCaulay samplers and soil augers. Sample localities included high mountain (>2500 meters), river floodplain, and Gulf coastal plain. Peat deposits ranged from as thin as 20 cm to greater than 460 cm. Within the peat deposits, ash (that material which will remain following combustion) occurs both dispersed within the peat layers and as layers containing nearly 100% inorganic material interstratified with the peat layers. Ash in Costa Rican peats includes material derived from both organic and inorganic origins. The predominant inorganically derived material is volcanic and may result from direct volcanic ashfall into the peat environment or as detritus transported into the peat areas. Volcanic ash is rapidly altered within the peats, leaving little if any relict structures. Alteration products are pedominantly kaolin and smectite clays and gibbsite. Unaltered minerals identified by x-ray diffraction include quartz, cristobalite, plagiolase feldspar, and anatase. Hematite and bassanite (identified by x-ray diffraction) are present but result from the alteration of iron-bearing minerals and organic sulfur or gypsum during sample preparation. Pyrite is present as a very minor component of some Costa Rican peats. Organically-derived ash constituents in Costa Rican peats include siliceous diatoms, siliceous sponge spicules, and silica phytoliths. The type and abundance of ash constituents within Costa Rican peats can be evaluated based on geographic location of the peat deposits, the geologic conditions affecting their deposition, and the plant communities existing during deposition. 6 refs., 11 figs., 3 tabs.

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

    Directory of Open Access Journals (Sweden)



    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.

  9. Gigantic landslides versus glacial deposits: on origin of large hummock deposits in Alai Valley, Northern Pamir (United States)

    Reznichenko, Natalya


    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

  10. Deposition and high temperature corrosion in a 10 MW straw

    DEFF Research Database (Denmark)

    Michelsen, Hanne Philbert; Frandsen, Flemming; Dam-Johansen, Kim


    Deposition and corrosion measurements were conducted at a 10 MW wheat straw fired stoker boiler used for combined power and heat production. The plant experiences major problems with deposits on the heat transfer surfaces, and test probes have shown enhanced corrosion due to selective corrosion...... for metal temperatures above 520 C. Deposition measurements carried out at a position equal to the secondary superheater showed deposits rich in potassium and chlorine and to a lesser extent in silicon, calcium, and sulfur. Potassium and chlorine make up 40-80 wt% of the deposits. Mechanisms of deposit...

  11. Ti-doped hydrogenated diamond like carbon coating deposited by hybrid physical vapor deposition and plasma enhanced chemical vapor deposition (United States)

    Lee, Na Rae; Sle Jun, Yee; Moon, Kyoung Il; Sunyong Lee, Caroline


    Diamond-like carbon films containing titanium and hydrogen (Ti-doped DLC:H) were synthesized using a hybrid technique based on physical vapor deposition (PVD) and plasma enhanced chemical vapor deposition (PECVD). The film was deposited under a mixture of argon (Ar) and acetylene gas (C2H2). The amount of Ti in the Ti-doped DLC:H film was controlled by varying the DC power of the Ti sputtering target ranging from 0 to 240 W. The composition, microstructure, mechanical and chemical properties of Ti-doped DLC:H films with varying Ti concentrations, were investigated using Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), nano indentation, a ball-on-disk tribometer, a four-point probe system and dynamic anodic testing. As a result, the optimum composition of Ti in Ti-doped DLC:H film using our hybrid method was found to be a Ti content of 18 at. %, having superior electrical conductivity and high corrosion resistance, suitable for bipolar plates. Its hardness value was measured to be 25.6 GPa with a low friction factor.

  12. Dynamics and Deposits of Coignimbrite Plumes (United States)

    Engwell, Samantha; de'Michieli Vitturi, Mattia; Esposti Ongaro, Tomaso; Neri, Augusto


    Fine ash in the atmosphere poses a significant hazard, with potentially disastrous consequences for aviation and, on deposition, health and infrastructure. Fine-grained particles form a large proportion of ejecta in Plinian volcanic clouds. However, another common, but poorly studied phenomena exists whereby large amounts of fine ash are injected into the atmosphere. Coignimbrite plumes form as material is elutriated from the top of pyroclastic density currents. The ash in these plumes is considerably finer grained than that in Plinian plumes and can be distributed over thousands of kilometres in the atmosphere. Despite their significance, very little is known regarding coignimbrite plume formation and dispersion, predominantly due to the poor preservation of resultant deposits. As a result, consequences of coignimbrite plume formation are usually overlooked when conducting hazard and risk analysis. In this study, deposit characteristics and numerical models of plumes are combined to investigate the conditions required for coignimbrite plume formation. Coignimbrite deposits from the Campanian Ignimbrite eruption (Magnitude 7.7, 39 ka) are well sorted and very fine, with a mode of between 30 and 50 microns, and a significant component of respirable ash (less than 10 microns). Analogous distributions are found for coignimbrite deposits from Tungurahua 2006 and Volcan de Colima (2004-2006), amongst others, regardless of magnitude, type or chemistry of eruption. These results indicate that elutriation processes are the dominant control on coignimbrite grainsize distribution. To further investigate elutriation and coignimbrite plume dynamics, the numerical plume model of Bursik (2001) is applied. Model sensitivity analysis demonstrates that neutral buoyancy conditions (required for the formation of the plume) are controlled by a balance between temperature and gas mass flux in the upper most parts of the pyroclastic density current. In addition, results emphasize the

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

    Energy Technology Data Exchange (ETDEWEB)

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


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

  14. Metallogenic evolution of uranium deposits in the Middle East and North Africa deposits (United States)

    Howari, Fares; Goodell, Philip; Salman, Abdulaty


    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.

  15. Nitrate dry deposition measurements with surrogate surfaces (United States)

    Zhu, Xiang

    Nitrate dry deposition is one of the most important topics in the study of the dry deposition of acidic and acidifying substances. This study measured nitrate dry deposition to (1) a water surface sampler (WSS) which was recently developed in the Department of Chemical and Environmental Engineering at Illinois Institute of Technology, (2) a Nylasorb filter on a knife-edge surrogate surface and (3) a greased strip on a knife-edge surrogate surface. Airborne nitric acid (HNO3), nitrous acid (HNO2), and nitrogen dioxide (NO2) concentrations were also measured concurrently with the flux measurements. These measurements were then used to evaluate the utility of using surrogate surfaces, and in particular the WSS, to measure nitrate dry deposition. The nitrogen containing species that may be responsible for nitrate dry deposition to the WSS include nitrogen monoxide (NO), NO2, peroxyacetyl nitrate (PAN), ammonia (NH3) and ammonium (NH4+), HNO2,/ HNO3, and particulate nitrate. Theoretical calculations and experiments showed that HNO3 and particulate nitrate appear to be the major nitrate contributors to the water surface sampler. Nitrate dry deposition to the water surface, Nylasorb filter and the greased strip were measured during the daytime in June and July 1995 and during both the day and night time in September and October 1995. The results showed that during the daytime in June and July the average nitrate dry deposition to the WSS (36.28 mg/m2-day) was much higher than that to the Nylasorb filter (14.04 mg/m2-day). However, during September and October there is no statistically significant difference in nitrate deposition flux between the WSS (average 4.59 mg/m2-day for the nighttime and 10.58 mg/m2-day for the daytime) and the Nylasorb filter (average 4.53 mg/m2-day for the nighttime and 8.87 mg/m2-day). A set of three experiments showed that particulate nitrate fluxes measured with the greased strip were underestimated due to the loss of volatile particulate

  16. Financial products as alternatives to traditional deposits

    Directory of Open Access Journals (Sweden)

    Cristina Lidia MANEA


    In this context, increasing the safety of depositors appears as an undisputed necessity, which translates to our approach in the development of a constructive type applied research that takes into account the following stages: short description of risks and uncertainties characterizing the economic environment with emphasis on the importance of the financial instruments; analysis of empirical data on deposits in lei and euro at national level, identifying possible causes which led to one preference or another and finding the causes underlying the different options manifested in the capital, as compared to other counties; identifying the products that offer a dangerous alternative to traditional deposits from the Romanian banking market and describing these products and their related risks; the proposal of a new product, demonstrating its effectiveness by testing and confirmation of two hypotheses.

  17. Surface acoustic wave dust deposition monitor (United States)

    Fasching, G.E.; Smith, N.S. Jr.


    A system is disclosed for using the attenuation of surface acoustic waves to monitor real time dust deposition rates on surfaces. The system includes a signal generator, a tone-burst generator/amplifier connected to a transmitting transducer for converting electrical signals into acoustic waves. These waves are transmitted through a path defining means adjacent to a layer of dust and then, in turn, transmitted to a receiving transducer for changing the attenuated acoustic wave to electrical signals. The signals representing the attenuated acoustic waves may be amplified and used in a means for analyzing the output signals to produce an output indicative of the dust deposition rates and/or values of dust in the layer. 8 figs.

  18. Chemical Vapour Deposition of Large Area Graphene

    DEFF Research Database (Denmark)

    Larsen, Martin Benjamin Barbour Spanget

    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, and (2) optimize the process of growing high quality graphene in terms of carrier mobility, and crystal...... structure. Optimization of a process for graphene growth on commercially available copper foil is limited by the number of aluminium oxide particles on the surface of the catalyst. By replacing the copper foil with a thin deposited copper film on a SiO2/Si or c-plane sapphire wafer the particles can...

  19. Skin deposits in hereditary cystatin C amyloidosis

    DEFF Research Database (Denmark)

    Benedikz, Eirikur; Blöndal, H; Gudmundsson, G


    . Skin from 12 individuals who served as controls and skin from 14 close relatives of the patients was negative for amyloid. Punch biopsy of the skin is a simple procedure which is of value for the diagnosis of HCCA, even before the appearance of clinical symptoms. This method might also be of use......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...

  20. Hematite Deposits at Opportunity Landing Site (United States)


    This vertical cross-section of the Meridiani Planum region shows that the hematite-bearing plains are part of an extensive set of deposits on top of the ancient, heavily cratered terrain. The Mars Exploration Rover Opportunity is targeted to land here on January 24, 2004 Pacific Standard Time. The background surface image of Meridiani Planum was acquired by the Mars Orbital Camera on NASA's Mars Global Surveyor. On Earth, grey hematite is an iron oxide mineral that typically forms in the presence of liquid water. The rover Opportunity will study the martian terrain and examine the hematite deposits to determine whether liquid water was present in the past when rocks were being formed.

  1. Iron films deposited on porous alumina substrates

    Energy Technology Data Exchange (ETDEWEB)

    Yamada, Yasuhiro, E-mail:; Tanabe, Kenichi; Nishida, Naoki [Tokyo University of Science (Japan); Kobayashi, Yoshio [The University of Electro-Communications (Japan)


    Iron films were deposited on porous alumina substrates using an arc plasma gun. The pore sizes (120 – 250 nm) of the substrates were controlled by changing the temperature during the anodic oxidation of aluminum plates. Iron atoms penetrated into pores with diameters of less than 160 nm, and were stabilized by forming γ-Fe, whereas α-Fe was produced as a flat plane covering the pores. For porous alumina substrates with pore sizes larger than 200 nm, the deposited iron films contained many defects and the resulting α-Fe had smaller hyperfine magnetic fields. In addition, only a very small amount of γ-Fe was obtained. It was demonstrated that the composition and structure of an iron film can be affected by the surface morphology of the porous alumina substrate on which the film is grown.

  2. Atmospheric nitrogen compounds: Occurrence, composition and deposition

    DEFF Research Database (Denmark)

    Nielsen, T.; Pilegaard, K.; Egeløv, A.H.


    Traffic in cities and on highways is an important contributor to NOy atmospheric pollution in open areas. In this situation both the concentration and composition of NOy compounds show a wide variation and are dependent on meteorological and atmospheric chemical conditions. The proportion of NOz...... compounds (HNO3+nitrate+PAN+ PPN+N2O5+organic nitrates) increases while that of NOx decreases with increasing ozone concentrations. The dry deposition velocity of NO2 was determined to be 0.2 cm s(-1) above vegetation. The dry deposition contribution of the different NOy compounds was evaluated....... The possibility that a significant contribution is caused by a group of unidentified NOy compounds cannot be excluded. Therefore, future investigations of atmospheric pollution of sensitive ecosystems, at conditions with a relatively high atmospheric content of NOy compared to that of NH3, ought to take...

  3. Microbiological processes in banded iron formation deposition

    DEFF Research Database (Denmark)

    Posth, Nicole R.; Konhauser, Kurt O.; Kappler, Andreas


    Banded iron formations have been studied for decades, particularly regarding their potential as archives of the Precambrian environment. In spite of this effort, the mechanism of their deposition and, specifically, the role that microbes played in the precipitation of banded iron formation minerals......, remains unresolved. Evidence of an anoxic Earth with only localized oxic areas until the Great Oxidation Event ca 2·45 to 2·32 Ga makes the investigation of O2-independent mechanisms for banded iron formation deposition relevant. Recent studies have explored the long-standing proposition that Archean...... banded iron formations may have been formed, and diagenetically modified, by anaerobic microbial metabolisms. These efforts encompass a wide array of approaches including isotope, ecophysiological and phylogeny studies, molecular and mineral marker analysis, and sedimentological reconstructions. Herein...

  4. Thermal energy storage in granular deposits (United States)

    Ratuszny, Paweł


    Energy storage technology is crucial for the development of the use of renewable energy sources. This is a substantial constraint, however it can, to some extent, be solved by storing energy in its various forms: electrical, mechanical, chemical and thermal. This article presents the results of research in thermal properties of granular deposits. Correlation between temperature changes in the stores over a period of time and their physical properties has been studied. The results of the research have practical application in designing thermal stores based on bulk materials and ground deposits. Furthermore, the research results are significant for regeneration of the lower ground sources for heat pumps and provide data for designing ground heat exchangers for ventilation systems.

  5. Early Cambrian wave-formed shoreline deposits

    DEFF Research Database (Denmark)

    Clemmensen, Lars B; Glad, Aslaug Clemmensen; Pedersen, Gunver Krarup


    . During this period, wave-formed shoreline sediments (the Vik Member, Hardeberga Formation) were deposited on Bornholm and are presently exposed at Strøby quarry. The sediments consist of fine- and medium-grained quartz-cemented arenites in association with a few silt-rich mudstones. The presence of well......-preserved subaqueous dunes and wave ripples indicates deposition in a wave-dominated upper shoreface (littoral zone) environment, and the presence of interference ripples indicates that the littoral zone environment experienced water level fluctuations due to tides and/or changing meteorological conditions. Discoidal...... imprints is related to either the formation of thin mud layers, formed during a period of calm water when winds blew offshore for a longer period, or to the growth of bacterial mats. The orientation of the wave-formed bedforms indicates a local palaeoshoreline trending NE–SW and facing a large ocean...

  6. Dense deposit disease and C3 glomerulopathy. (United States)

    Barbour, Thomas D; Pickering, Matthew C; Terence Cook, H


    C3 glomerulopathy refers to those renal lesions characterized histologically by predominant C3 accumulation within the glomerulus, and pathogenetically by aberrant regulation of the alternative pathway of complement. Dense deposit disease is distinguished from other forms of C3 glomerulopathy by its characteristic appearance on electron microscopy. The extent to which dense deposit disease also differs from other forms of C3 glomerulopathy in terms of clinical features, natural history, and outcomes of treatment including renal transplantation is less clear. We discuss the pathophysiology of C3 glomerulopathy, with evidence for alternative pathway dysregulation obtained from affected individuals and complement factor H (Cfh)-deficient animal models. Recent linkage studies in familial C3 glomerulopathy have shown genomic rearrangements in the Cfh-related genes, for which the novel pathophysiologic concept of Cfh deregulation has been proposed. © 2013 Elsevier Inc. All rights reserved.

  7. Monitoring particle growth in deposition plasmas (United States)

    Schlebrowski, T.; Bahre, H.; Böke, M.; Winter, J.


    Plasma-enhanced chemical vapor deposition methods are frequently used to deposit barrier layers, e.g. on polymers for food packaging. These plasmas may suffer from particle (dust) formation. We report on a flexible monitoring system for dust. It is based on scanning a 3D plasma volume for particles by laser light scattering. The lower size limit of particles detected in the presented system is 20 nm. We report on existence diagrams for obtaining dust free or dust loaded capacitively or inductively coupled rf-plasmas in C2H2 depending on pressure, flow and rf-power. We further present growth rates for dust in these plasmas and show that monodisperse particles are only obtained during the first growth cycle.

  8. 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


    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

  9. Mixing from below in hydrothermal ore deposits (United States)

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


    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

  10. Atmospheric Transport and Deposition of Agricultural Chemicals (United States)

    Majewski, M. S.; Vogel, J. R.; Capel, P. D.


    Concentrations of more than 80 pesticides and select transformation products were measured in atmospheric deposition during two growing seasons in five agricultural areas across the United States. Rainfall samples were collected at study areas in California, Indiana, Maryland, and Nebraska. In the arid Yakima Valley of Washington, dry deposition for the same compounds was estimated using air concentration measurements and depositional models. In the predominantly corn, soybean, and alfalfa growing region of Nebraska, Indiana, and Maryland, the herbicides acetochlor, alachlor, atrazine, and metolachlor where the predominant pesticides detected, and the highest concentrations ranged from 0.64 microgram per liter (ug/L) for metolachlor in a small, predominantly dairy use dominated watershed in Maryland to 6.6 ug/L and 19 ug/L for atrazine in Indiana and Nebraska, respectively. California showed a different seasonal occurrence pattern and suite of detected pesticides because the rainy season occurs during the winter months and a wide variety of crops are grown throughout the year. With the exception of metolachlor (0.23 ug/L, max.), the corn and soybean herbicides were not used to any great extent in the California study area and were not detected. The insecticides diazinon (1.21 ug/L, max.) and chlorpyrifos (0.12 ug/L, max.) were detected in nearly every sample taken in California. The Washington study area was similar to California in terms of the variety of crops grown and the pesticides use, but it receives very little rainfall. Dry deposition was estimated at this site from air concentrations and particle settling velocities. The results of these studies show the importance of the atmosphere as an additional source of pesticide loading to agricultural watersheds.

  11. Antireflection coatings on plastics deposited by plasma ...

    Indian Academy of Sciences (India)


    software (FTG 1997). It was found that a thickness of. 150 nm, and a chosen refractive index of 1⋅50, for the carbonyl SiO2 layer yielded best results for the composite. ARC deposited on the carbonyl SiO2 layer, and so these values have been chosen for the carbonyl SiO2 layer in the design process. The refractive indices ...

  12. Spray-Deposited Superconductor/Polymer Coatings (United States)

    Wise, Stephanie A.; Tran, Sang Q.; Hooker, Matthew W.


    Coatings that exhibit the Meissner effect formed at relatively low temperature. High-temperature-superconductor/polymer coatings that exhibit Meissner effect deposited onto components in variety of shapes and materials. Simple, readily available equipment needed in coating process, mean coatings produced economically. Coatings used to keep magnetic fields away from electronic circuits in such cryogenic applications as magnetic resonance imaging and detection of infrared, and in magnetic suspensions to provide levitation and/or damping of vibrations.

  13. Controlled Deposition and Alignment of Carbon Nanotubes (United States)

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


    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.

  14. Magnetic filtered plasma deposition and implantation technique

    CERN Document Server

    Zhang Hui Xing; Wu Xian Ying


    A high dense metal plasma can be produced by using cathodic vacuum arc discharge technique. The microparticles emitted from the cathode in the metal plasma can be removed when the metal plasma passes through the magnetic filter. It is a new technique for making high quality, fine and close thin films which have very widespread applications. The authors describe the applications of cathodic vacuum arc technique, and then a filtered plasma deposition and ion implantation system as well as its applications

  15. Electrostatic force assisted deposition of graphene (United States)

    Liang, Xiaogan [Berkeley, CA


    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.

  16. Sediment-hosted Pb-Zn Deposits: a global perspective (United States)

    Leach, David L.; Sangster, Donald F.; Kelley, Karen D.; Large, R; Garven, G.; Allen, Craig R.


    Sediment-hosted Pb-Zn deposits contain the world's greatest lead and zinc resources and dominate world production of these metals. They are a chverse group of ore deposits hosted by a wide variety of carbonate and siliciclastic roch that have no obviolls genetic association with igneous activity. A nmge of ore-fortl1ing processes in a vmiety of geologic and tectonic environments created these deposits over at least two billion years of Earth history. The metals were precipitated by basinal brines in synsedimentary and early diagenetic to low-grade metamorphic environments. The deposits display a broad range of relationships to enclosing host rocks that includes stratiform, strata-bound, and discordant ores. These ores are divided into two broad subt)1Jes: Mississippi Valley-type (MVT) and sedimentmy exhalative (SEDEX), Despite the "exhalative" component inherent in the term "SEDEX," in this manusclipt, direct evidence of an exhalite in the ore or alteration component is not essential for a deposit to be classified as SEDEX. The presence of laminated sulfides parallel to bedding is assumed to be permissive evidence for exhalative ores. The chstinction between some SEDEX and MVT depOSits can be quite subjective because some SEDEX ores replaced carbonate, whereas some MVT depOSits formed in an early diagenetic environment and display laminated ore textures. Geologic and resource information are presented for 248 depositS that provide a framework to describe ,mel compare these deposits. Nine of tlle 10 largest sediment-hosted Pb-Zn deposits are SEDEX, Of the deposits that contain at least 2.5 million metric tons (Mt), there are 35 SEDEX (excluding Broken Hill-type) deposits and 15 MVT (excluding Iris-type) deposits. Despite the skewed distribution of the deposit size, the two deposits types have an excellent correlation between total tonnage and tonnage of contained metal (Pb + Zn), with a fairly consistent ratio of about lO/l, regardless of the size of the deposit or

  17. Particle size-density relationships in pyroclastic deposits: using component subpopulations to elucidate depositional conditions (United States)

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


    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

  18. Pulsed laser deposition of rare earth compounds

    CERN Document Server

    Stone, L A


    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...


    Directory of Open Access Journals (Sweden)

    Anto Gabrić


    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.

  20. Supersonic Flow Control Using Combined Energy Deposition

    Directory of Open Access Journals (Sweden)

    O. A. Azarova


    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.

  1. Placer tin deposits in central Alaska (United States)

    Chapman, Robert Mills; Coats, Robert Roy; Payne, Thomas G.


    Placer tin, in the form of cassiterite (Sn02) and (or) tinstone (fragments including cassiterite and some vein or rock material), is known or reported in deposits that have been prospected or mined for placer gold in four areas adjacent to the Yukon River in central Alaska, 120 to 240 miles west of Fairbanks. These areas are: the Morelock Creek area, on the north side of the Yukon River about 30 miles upstream from Tanana; the Moran Dome area, about 16 miles north of the Yukon River and 25 miles northwest of Tanana; the Mason Creek area, on the north side of the Yukon River about 36 miles west of Tanana; and the Ruby-Long area, on the south side of the Yukon River near Ruby and about 40 miles east of Galena. The only extensive placer mining in these areas has been in the Ruby-Long area. Other placer deposits including some cassiterite are known in central Alaska but are not discussed in this report. Bedrock in these areas is predominantly schist of various types with some associated greenstone and other metamorphic rocks. Some granite is exposed in the Moran Dome and Ruby-Long areas and in areas close to Morelock and Mason Creeks. Barren, milky quartz veins and veinlets transecting the metamorphic rocks are common. No cassiterite was found in the bedrock, and no bedrock source of the tin has been reported. In the Moran Dome and Mason Creek areas, and in part of the Ruby-Long area, tourmaline is present in the rocks of the tin-bearing drainage basins, and apparently absent elsewhere in these areas. The placer deposits are in both valley floor and bench alluvium, which are predominantly relatively thin, rarely exceeding a thickness of 30 feet. Most of the alluvium deposits are not perennially frozen. In the Morelock Creek area tin-bearing deposits are 5 to 5? miles above the mouth of the creek, and meager evidence indicates that cassiterite and gold are present in Morelock Creek valley and some of the tributaries both upstream and downstream from these deposits. The

  2. Deposition of plasmon gold–fluoropolymer nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Safonov, Alexey I., E-mail: [Kutateladze Institute of Thermophysics SB RAS, Lavrentyev Ave. 1, 630090, Novosibirsk (Russian Federation); Sulyaeva, Veronica S. [Nikolaev Institute of Inorganic Chemistry SB RAS, Lavrentyev Ave. 3, 630090, Novosibirsk (Russian Federation); Timoshenko, Nikolay I.; Kubrak, Konstantin V.; Starinskiy, Sergey V. [Kutateladze Institute of Thermophysics SB RAS, Lavrentyev Ave. 1, 630090, Novosibirsk (Russian Federation)


    Degradation-resistant two-dimensional metal–fluoropolymer composites consisting of gold nanoparticles coated with a thin fluoropolymer film were deposited on a substrate by hot wire chemical vapour deposition (HWCVD) and ion sputtering. The morphology and optical properties of the obtained coatings were determined. The thickness of the thin fluoropolymer film was found to influence the position of the surface plasmon resonance peak. Numerical calculations of the optical properties of the deposited materials were performed using Mie theory and the finite-difference time-domain (FDTD) method. The calculation results are consistent with the experimental data. The study shows that the position of the resonance peak can be controlled by changing the surface concentration of particles and the thickness of the fluoropolymer coating. The protective coating was found to prevent the plasmonic properties of the nanoparticles from changing for several months. - Highlights: • The gold–fluoropolymer composites are obtained by a combination of GJD and HWCVD. • The optical properties of composites were determined by experiments and calculation. • The dependence of SPR position on filling, NPs size and FP thickness were analyzed. • The plasmonic properties of the Au NPs are saved in the fluoropolymer matrix.

  3. Impact Response of Thermally Sprayed Metal Deposits (United States)

    Wise, J. L.; Hall, A. C.; Moore, N. W.; Pautz, S. D.; Franke, B. C.; Scherzinger, W. M.; Brown, D. W.


    Gas-gun experiments have probed the impact response of tantalum specimens that were additively manufactured using a controlled thermal spray deposition process. Velocity interferometer (VISAR) diagnostics provided time-resolved measurements of sample response under one-dimensional (i . e . , uniaxial strain) shock compression to peak stresses ranging between 1 and 4 GPa. The acquired wave-profile data have been analyzed to determine the Hugoniot Elastic Limit (HEL), Hugoniot equation of state, and high-pressure yield strength of the thermally deposited samples for comparison to published baseline results for conventionally wrought tantalum. The effects of composition, porosity, and microstructure (e . g . , grain/splat size and morphology) are assessed to explain differences in the dynamic mechanical behavior of spray-deposited versus conventional material. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

  4. Deposition of amorphous carbon-silver composites

    Energy Technology Data Exchange (ETDEWEB)

    Garcia-Zarco, O. [Instituto de Investigaciones en Materiales, Universidad Nacional Autonoma de Mexico, Circuito Exterior s/n, Ciudad Universitaria. 04510, Mexico D. F. Mexico (Mexico); Rodil, S.E., E-mail: ser42@iim.unam.m [Instituto de Investigaciones en Materiales, Universidad Nacional Autonoma de Mexico, Circuito Exterior s/n, Ciudad Universitaria. 04510, Mexico D. F. Mexico (Mexico); Camacho-Lopez, M.A. [Facultad de Quimica, Universidad Autonoma del Estado de Mexico, Tollocan s/n, esq. Paseo Colon, Toluca, Estado de Mexico, 50110 (Mexico)


    Composites of amorphous carbon films and silver were deposited by co-sputtering, where the target (10 cm diameter) was of pure graphite with small inclusion of pure silver (less than 1 cm{sup 2}). The films were deposited under different powers, from 40 to 250 W, and different target-substrate distances. The substrate was earthed and rotated in order to obtain a uniform distribution of the silver content. The addition of the Ag piece into the target increased the deposition rate of the carbon films, which could be related to the higher sputter yield of the silver, but there seems to be also a contribution from a larger emission of secondary electrons from the Ag that enhances the plasma and therefore the sputtering process becomes more efficient. Scanning electron micrographs acquired using backscattered electrons showed that the silver was segregated from the carbon matrix, forming nanoparticles or larger clusters as the power was increased. The X-ray diffraction pattern showed that the silver was crystalline and the carbon matrix remained amorphous, although for certain conditions a peak attributed to fullerene-like structures was obtained. Finally, we used Raman spectroscopy to understand the bonding characteristics of the carbon-silver composites, finding that there are variations in the D/G ratio, which can be correlated to the observed structure and X-ray diffraction results.

  5. 12 CFR 7.4007 - Deposit-taking. (United States)


    ... authority of the United States.” The Court stated that “ ndoubtedly a state has the legitimate power to... § 7.4007 Deposit-taking. (a) Authority of national banks. A national bank may receive deposits and...

  6. Application of design of experiment on electrophoretic deposition of ...

    Indian Academy of Sciences (India)


    ceramic coating materials on metal substrate by electrophoretic deposition technique in an aqueous medium has been described. The effects of various process parameters, e.g. coating material concentration, time of deposition, applied current, pH ...

  7. Evidence for change in depositional environment in the Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Rao, P.S.; Rao, Ch.M.

    cm interval were analyzed for calcium carbonate, organic carbon and reduced sulfur contents. Sedimentological analysis indicates that the core contains hemipelagic Globigerina ooze of Holocene age at the top, underlain by sediments depositEd...

  8. Multiwalled Carbon Nanotube Deposition on Model Environmental Surfaces (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...

  9. Point locations and characteristics of evaporite-related potash deposits (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...

  10. Ash Deposition Trials at Three Power Stations in Denmark

    DEFF Research Database (Denmark)

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


    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...

  11. Nitrogen Deposition onto the United States and Western Europe (United States)

    National Aeronautics and Space Administration — This data set contains data for wet and dry nitrogen-species deposition for the United States and Western Europe. Deposition data were acquired directly from...

  12. Management of polluted deposit in lake and river

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Chang Hee; Kim, Eun Jung [Korea Environment Institute, Seoul (Korea)


    In this study, the perception and problem of polluted deposit in Korea, which does not have a clear concept of it, were analyzed and the need of a comprehensive polluted deposit management, including the present condition of pollution, assessment, pollution prevention, and disposal of polluted deposit, was presented. Based on the analysis on foreign management system, the framework of polluted deposit management in Korea was provided. 84 refs., 11 figs., 40 tabs.

  13. Processing Research on Chemically Vapor Deposited Silicon Nitride. (United States)


    34 sea urchins ") predominated, suggesting that formation was primarily from the vapor phase with little of the nodular growths seen at only slightly...deposition parameters on crystallite size, morphology and deposition rate. Geometries include a cold-wall, flat plate reactor (CW) and 4-inch and 1-inch...typical crossections of banded deposits and deposits which showed transitions from amorphous to crystalline morphologies , respectively. Figure 2-5

  14. Strontium-Doped Lanthanum Manganite Films Prepared by Magnetic Deposition

    DEFF Research Database (Denmark)

    Menon, Mohan; Larsen, Casper; Andersen, Kjeld Bøhm


    Deposition of La0.85Sr0.15MnO3 (LSM) films from suspensions using a magnetic field was found to be a cheap and quick technique. Ninety weight percent of the particles present in the suspensions were deposited within the first minute of the deposition, and the thickness of the film varied linearly...

  15. Pebble orientation on large, experimental debris-flow deposits (United States)

    Major, J.J.


    Replicable, pronounced orientation of discoid pebbles (??? 8 mm) embedded on surfaces of large (??? 10 m3) experimental debris-flow deposits reveals that strongly aligned, imbricate fabric can develop rapidly over short distances in mass flows. Pebble long axes aligned subparallel to deposit margins as well as subparallel to margins of surge waves arrested within the deposits. Pebble alignment exhibited modes both parallel to (a(p)), and normal to (a(t)), the primary flow direction; intermediate axes dipped preferentially inward from surge-wave margins (b(i) orientation). Repetitive development of margin-parallel, imbricate fabric distributed across deposit surfaces provides compelling evidence that deposits formed dominantly through progressive incremental accretion rather than through simple en masse emplacement. Pronounced fabric along deposit and arrested surge-wave margins reflects significant grain interaction along flow margins. This sedimentological evidence for significant marginal grain interaction complements theoretical analyses (Iverson, 1997) and other experimental data (Major, 1996: Iverson, 1997) that indicate that resistance along flow margins is an important factor affecting debris-flow deposition. The fabric on the experimental deposits demonstrates that debris flows can develop strongly imbricate particle orientation that mimics fabric developed during fluvial deposition. Particle shape and local stress fields appear to have more control over fabric development than does general depositional process. Other criteria in addition to particle orientation are needed to discriminate mass flow from fluvial gravel deposits and to unravel depositional history. ?? 1998 Elsevier Science B.V. All rights reserved.

  16. Optimizing growth conditions for electroless deposition of Au films ...

    Indian Academy of Sciences (India)


    Cathodic: Mn+ + ne– → M (M = metal). The advantages of electroless deposition are many: it is simple, relatively inexpensive and does not generally depend on the shape, size or conductivity of the substrate but yields high purity films. Using electroless deposition, several metals have been deposited on Si and Ge surfaces.

  17. Electrophoretic deposition of titania nanoparticles: Wet density of ...

    Indian Academy of Sciences (India)


    Abstract. 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.

  18. Spatial atomic layer deposition of zinc oxide thin films

    NARCIS (Netherlands)

    Illiberi, A.; Roozeboom, F.; Poodt, P.W.G.


    Zinc oxide thin films have been deposited at high growth rates (up to ~1 nm/s) by spatial atomic layer deposition technique at atmospheric pressure. Water has been used as oxidant for diethylzinc (DEZ) at deposition temperatures between 75 and 250 °C. The electrical, structural (crystallinity and

  19. 46 CFR 391.2 - Ceiling on deposits. (United States)


    ... 46 Shipping 8 2010-10-01 2010-10-01 false Ceiling on deposits. 391.2 Section 391.2 Shipping... TAX ASPECTS OF THE CAPITAL CONSTRUCTION FUND § 391.2 Ceiling on deposits. (a) In general—(1) Total ceiling. Section 607(b) of the Act provides a ceiling on the amount which may be deposited by a party for...

  20. 18 CFR 385.404 - Depositions during proceedings (Rule 404). (United States)


    ... otherwise. (4) The deposition must be transcribed verbatim. (d) Nonstenographic means of recording... deponent, the transcription of the deposition must be submitted to the deponent for examination. (2) If the... deposition with a copy of the transcription. (2) Documents and things produced for inspection during the...

  1. 24 CFR 291.535 - Earnest money deposit. (United States)


    ... 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 firefighter/emergency...

  2. 31 CFR 515.326 - Custody of safe deposit boxes. (United States)


    ... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false Custody of safe deposit boxes. 515... Definitions § 515.326 Custody of safe deposit boxes. Safe deposit boxes shall be deemed to be in the custody... upon the meaning of the term custody. ...

  3. 31 CFR 500.326 - Custody of safe deposit boxes. (United States)


    ... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false Custody of safe deposit boxes. 500... Definitions § 500.326 Custody of safe deposit boxes. Safe deposit boxes shall be deemed to be in the custody... upon the meaning of the term custody. ...

  4. Particle deposition to forests : Summary of results and application

    NARCIS (Netherlands)

    Erisman, J.W.; Draaijers, G.; Duyzer, J.; Hofschreuder, P.; Leeuwen, van P.; Römer, F.; Ruijgrok, W.; Wyers, P.; Gallagher, M.


    Particle deposition to forest was studied at Speulder forest using experimental and modelling results. In this paper a short overview of the main results is given and they are applied in generalisation of deposition in The Netherlands. The results of the Aerosol project show that the deposition of

  5. Low pressure chemical vapour deposition at quasi-high flow

    NARCIS (Netherlands)

    Holleman, J.; Middelhoek, Jan


    A new chemical vapour deposition (CVD) technique is presented. It is especially advantageous for the deposition of compound materials. The technique improves the uniformity and reproducibility of the deposition. The economical use of gaseous reactants is improved by a factor varying between 5 and

  6. Deposition of a fine powder in horizontal pipelines and bends

    NARCIS (Netherlands)

    Reuvekamp, RJ; Ray, MB; Hoffmann, AC

    The deposition of a very fine powder in a horizontal, lean-phase pneumatic conveying conduit containing a 90degrees bend has been studied experimentally. The total deposition and the deposition pattern were studied as a function of superficial gas velocity, solids loading and bend geometry: one

  7. Imposed layer by layer growth by pulsed laser interval deposition

    NARCIS (Netherlands)

    Koster, Gertjan; Rijnders, Augustinus J.H.M.; Blank, David H.A.; Rogalla, Horst


    Pulsed laser deposition has become an important technique to fabricate novel materials. Although there is the general impression that, due to the pulsed deposition, the growth mechanism differs partially from continuous physical and chemical deposition techniques, it has hardly been used. Here, we

  8. Simulated dry deposition of nitric acid near forest edges

    NARCIS (Netherlands)

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


    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

  9. 12 CFR 303.243 - Brokered deposit waivers. (United States)


    ... 12 Banks and Banking 4 2010-01-01 2010-01-01 false Brokered deposit waivers. 303.243 Section 303.243 Banks and Banking FEDERAL DEPOSIT INSURANCE CORPORATION PROCEDURE AND RULES OF PRACTICE FILING PROCEDURES Other Filings § 303.243 Brokered deposit waivers. (a) Scope. Pursuant to section 29 of the FDI Act...

  10. 5 CFR 1639.12 - Deposit of funds collected. (United States)


    ... 5 Administrative Personnel 3 2010-01-01 2010-01-01 false Deposit of funds collected. 1639.12... Administrative Collection, Compromise, Termination, and Referral of Claims § 1639.12 Deposit of funds collected. All funds owed to the Board and collected under this part will be deposited in the Thrift Savings Fund...

  11. 46 CFR 287.14 - Deposit of earnings and receipts. (United States)


    ... 46 Shipping 8 2010-10-01 2010-10-01 false Deposit of earnings and receipts. 287.14 Section 287.14... OPERATORS ESTABLISHMENT OF CONSTRUCTION RESERVE FUNDS § 287.14 Deposit of earnings and receipts. (a) Earnings. A citizen may deposit all or any part of earnings derived from the operation, within the scope of...

  12. 30 CFR 250.1603 - Determination of sulphur deposit. (United States)


    ... 30 Mineral Resources 2 2010-07-01 2010-07-01 false Determination of sulphur deposit. 250.1603... Determination of sulphur deposit. (a) Upon receipt of a written request from the lessee, the District Manager will determine whether a sulphur deposit has been defined that contains sulphur in paying quantities (i...

  13. 37 CFR 211.5 - Deposit of identifying material. (United States)


    ... 37 Patents, Trademarks, and Copyrights 1 2010-07-01 2010-07-01 false Deposit of identifying... COPYRIGHT OFFICE AND PROCEDURES MASK WORK PROTECTION § 211.5 Deposit of identifying material. (a) General. This section prescribes rules pertaining to the deposit of identifying material for registration of a...

  14. 26 CFR 403.29 - Deposit of collateral. (United States)


    ... 26 Internal Revenue 18 2010-04-01 2010-04-01 false Deposit of collateral. 403.29 Section 403.29... ADMINISTRATION DISPOSITION OF SEIZED PERSONAL PROPERTY Seizures and Forfeitures § 403.29 Deposit of collateral... principal by the United States, may be pledged and deposited by claimants as collateral security in lieu of...

  15. Starch deposits in Themeda triandra Forsk | WRE | African Journal of ...

    African Journals Online (AJOL)

    Themeda triandra tillers were examined microscopically at one to two-weekly intervals to determine where starch was deposited. Large numbers of starch grains were always present but the position of these deposits varied according to growth activity and flowering time of the plant. Starch deposits in the roots were usually ...

  16. 27 CFR 24.151 - Deposit of collateral security. (United States)


    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Deposit of collateral... § 24.151 Deposit of collateral security. (a) Bonds or notes of the United States, or other obligations... pledged and deposited as collateral security in lieu of corporate sureties in accordance with the...

  17. 12 CFR Appendix C to Part 360 - Deposit File Structure (United States)


    ... 12 Banks and Banking 4 2010-01-01 2010-01-01 false Deposit File Structure C Appendix C to Part 360 Banks and Banking FEDERAL DEPOSIT INSURANCE CORPORATION REGULATIONS AND STATEMENTS OF GENERAL POLICY RESOLUTION AND RECEIVERSHIP RULES Pt. 360, App. C Appendix C to Part 360—Deposit File Structure This is the...

  18. 19 CFR 10.135 - Deposit of duties. (United States)


    ... 19 Customs Duties 1 2010-04-01 2010-04-01 false Deposit of duties. 10.135 Section 10.135 Customs... Actual Use § 10.135 Deposit of duties. When the requirement of § 10.134 has been met the merchandise may be entered or withdrawn from warehouse for consumption without deposit of duty when proof of use will...

  19. 27 CFR 28.42 - Evidence of deposit. (United States)


    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Evidence of deposit. 28.42 Section 28.42 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT... Use § 28.42 Evidence of deposit. The deposit of distilled spirits in a customs bonded warehouse or...

  20. 46 CFR 308.509 - Collateral deposit fund. (United States)


    ... 46 Shipping 8 2010-10-01 2010-10-01 false Collateral deposit fund. 308.509 Section 308.509... Risk Cargo Insurance Ii-Open Policy War Risk Cargo Insurance § 308.509 Collateral deposit fund. (a) Requirements. An assured electing to use a cash collateral deposit fund pursuant to § 308.507 shall comply with...

  1. 19 CFR 144.25 - Deposit of forms. (United States)


    ... 19 Customs Duties 2 2010-04-01 2010-04-01 false Deposit of forms. 144.25 Section 144.25 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY... Warehouse § 144.25 Deposit of forms. Either the transferor or the transferee may deposit the endorsed...

  2. 42 CFR 35.33 - Sale; prices; deposit of proceeds. (United States)


    ... 42 Public Health 1 2010-10-01 2010-10-01 false Sale; prices; deposit of proceeds. 35.33 Section 35...; deposit of proceeds. The board shall determine and redetermine from time to time the prices at which... of the Service. Moneys received from the sale of articles shall be deposited into the Treasury to the...

  3. 27 CFR 17.104 - Deposit of collateral. (United States)


    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Deposit of collateral. 17... PRODUCTS Bonds and Consents of Sureties § 17.104 Deposit of collateral. Except as otherwise provided by law... guaranteed as to both interest and principal by the United States, may be pledged and deposited by principals...

  4. 27 CFR 72.25 - Deposit of collateral. (United States)


    ... 27 Alcohol, Tobacco Products and Firearms 2 2010-04-01 2010-04-01 false Deposit of collateral. 72... Seizures and Forfeitures § 72.25 Deposit of collateral. (a) Bonds or notes of the United States, or other... be pledged and deposited by claimants as collateral security in lieu of corporate sureties in...

  5. 12 CFR 996.3 - Demand deposit accounts. (United States)


    ... 12 Banks and Banking 7 2010-01-01 2010-01-01 false Demand deposit accounts. 996.3 Section 996.3... OF THE RESOLUTION FUNDING CORPORATION § 996.3 Demand deposit accounts. Each Bank shall allow any... establish and maintain at least one demand deposit account for the purpose of facilitating the Resolution...

  6. 46 CFR 310.62 - Allowances and expenses; required deposit. (United States)


    ... 46 Shipping 8 2010-10-01 2010-10-01 false Allowances and expenses; required deposit. 310.62... Allowances and expenses; required deposit. (a) Items furnished. Each midshipman shall receive: Free tuition... orders. (b) Required Deposit. Prior to admission to the Academy, each midshipman shall make a specified...

  7. 37 CFR 1.805 - Replacement or supplement of deposit. (United States)


    ... deposit. 1.805 Section 1.805 Patents, Trademarks, and Copyrights UNITED STATES PATENT AND TRADEMARK OFFICE, DEPARTMENT OF COMMERCE GENERAL RULES OF PRACTICE IN PATENT CASES Biotechnology Invention Disclosures Deposit of Biological Material § 1.805 Replacement or supplement of deposit. (a) A depositor, after receiving...

  8. Late Quaternary fine silt deposits of Jammu, NW Himalaya: Genesis ...

    Indian Academy of Sciences (India)

    Figure 20. Depositional model of the post-Siwalik deposit of the study area. (a) Lithofacies correlation and disposition of the various lithofacies. (b) Lateral lithofacies diagram of the exposed post-Siwalik deposits of the study area. The architecture shows the interfingering of channel (Gmm, Sm, Ss, Fl) and overbank facies.

  9. The Geometry and Structural Analysis of the Gold Deposits of ...

    African Journals Online (AJOL)

    The Chirano Mine gold deposit is a typical example of a structurally controlled deposit developed along the Kumasi Basin and the Sefwi Belt margin structure. The area has undergone various regimes of structural deformations. Consequently, all the Chirano deposits are intimately associated with shears and faults along a ...

  10. Electrophoretic deposition of titania nanoparticles: Wet density of ...

    Indian Academy of Sciences (India)

    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 ...

  11. Evaluation of the Acidic Wet Deposition Predictions of CMAQ (United States)

    Dennis, R. L.


    Acidic deposition is coming back into importance as part of more encompassing multi-pollutant thinking. Acidic and nutrient deposition is an important component of new multi-pollutant legislation being considered by the Administration. The Community Multiscale Air Quality model, CMAQ, was designed to handle multiple pollutants in a one-atmosphere context. Much of the initial evaluation of CMAQ was directed at the criteria pollutants. CMAQ's predictions of acidic deposition also need to be evaluated, not only because of the importance of deposition but also because deposition sets the lifetime of fine particles in the atmosphere. The controlling deposition is wet deposition, hence, we consider it first. We compare wet deposition for selected months throughout 1990, showing that CMAQ captures the main features of seasonality. We note that the previous problem of overprediction of winter wet deposition associated with the RADM cloud parameterization has been addressed through explicit recognition of icy cloud water. We are still plagued by the difficulty of meteorological models to predict precipitation as input to chemical transport models which produces additional scatter. Interestingly, there is a consistent differential between sulfate and nitrate wet deposition, with nitrate wet deposition being slightly lower. We explore several hypotheses for this behavior, including the hypothesis that this is more an issue of mixing than an issue of cloud chemistry. In general, CMAQ appears to be producing reasonable predictions that demonstrate an improvement in our ability to predict wet deposition, although there is room for improvement.

  12. Nickel-cobalt laterites: a deposit model: Chapter H in Mineral deposit models for resource assessment (United States)

    Marsh, Erin; Anderson, Eric J.; Gray, Floyd


    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

  13. Electrochemical deposited nickel nanowires: influence of deposition bath temperature on the morphology and physical properties (United States)

    Sofiah, A. G. N.; Kananathan, J.; Samykano, M.; Ulakanathan, S.; Lah, N. A. C.; Harun, W. S. W.; Sudhakar, K.; Kadirgama, K.; Ngui, W. K.; Siregar, J. P.


    This paper investigates the influence of the electrolytic bath temperature on the morphology and physical properties of nickel (Ni) nanowires electrochemically deposited into the anodic alumina oxide porous membrane (AAO). The synthesis was performed using nickel sulfate hexahydrate (NiSO4.6H2O) and boric acid (H3BO3) as an electrolytic bath for the electrochemical deposition of Ni nanowires. During the experiment, the electrolyte bath temperature varied from 40°C, 80°C, and 120°C. After the electrochemical deposition process, AAO templates cleaned with distilled water preceding to dissolution in sodium hydroxide (NaOH) solution to obtain free-standing Ni nanowires. Field Emission Scanning Electron Microscopy (FESEM), Energy Dispersive Spectroscopy (EDX) and X-ray Diffraction (XRD) analysis were employed to characterize the morphology and physical properties of the synthesized Ni nanowires. Finding reveals the electrodeposition bath temperature significantly influences the morphology and physical properties of the synthesized Ni nanowires. Rougher surface texture, larger crystal size, and longer Ni nanowires obtained as the deposition bath temperature increased. From the physical properties properties analysis, it can be concluded that deposition bath temperature influence the physical properties of Ni nanowires.

  14. Matrix shaped pulsed laser deposition: New approach to large area and homogeneous deposition

    Energy Technology Data Exchange (ETDEWEB)

    Akkan, C.K.; May, A. [INM – Leibniz Institute for New Materials, CVD/Biosurfaces Group, Campus D2 2, 66123 Saarbrücken (Germany); Hammadeh, M. [Department for Obstetrics, Gynecology and Reproductive Medicine, IVF Laboratory, Saarland University Medical Center and Faculty of Medicine, Building 9, 66421 Homburg, Saar (Germany); Abdul-Khaliq, H. [Clinic for Pediatric Cardiology, Saarland University Medical Center and Faculty of Medicine, Building 9, 66421 Homburg, Saar (Germany); Aktas, O.C., E-mail: [INM – Leibniz Institute for New Materials, CVD/Biosurfaces Group, Campus D2 2, 66123 Saarbrücken (Germany)


    Pulsed laser deposition (PLD) is one of the well-established physical vapor deposition methods used for synthesis of ultra-thin layers. Especially PLD is suitable for the preparation of thin films of complex alloys and ceramics where the conservation of the stoichiometry is critical. Beside several advantages of PLD, inhomogeneity in thickness limits use of PLD in some applications. There are several approaches such as rotation of the substrate or scanning of the laser beam over the target to achieve homogenous layers. On the other hand movement and transition create further complexity in process parameters. Here we present a new approach which we call Matrix Shaped PLD to control the thickness and homogeneity of deposited layers precisely. This new approach is based on shaping of the incoming laser beam by a microlens array and a Fourier lens. The beam is split into much smaller multi-beam array over the target and this leads to a homogenous plasma formation. The uniform intensity distribution over the target yields a very uniform deposit on the substrate. This approach is used to deposit carbide and oxide thin films for biomedical applications. As a case study coating of a stent which has a complex geometry is presented briefly.

  15. Atomic layer deposition of copper thin film and feasibility of deposition on inner walls of waveguides (United States)

    Yuqing, XIONG; Hengjiao, GAO; Ni, REN; Zhongwei, LIU


    Copper thin films were deposited by plasma-enhanced atomic layer deposition at low temperature, using copper(I)-N,N‧-di-sec-butylacetamidinate as a precursor and hydrogen as a reductive gas. The influence of temperature, plasma power, mode of plasma, and pulse time, on the deposition rate of copper thin film, the purity of the film and the step coverage were studied. The feasibility of copper film deposition on the inner wall of a carbon fibre reinforced plastic waveguide with high aspect ratio was also studied. The morphology and composition of the thin film were studied by atomic force microscopy and x-ray photoelectron spectroscopy, respectively. The square resistance of the thin film was also tested by a four-probe technique. On the basis of on-line diagnosis, a growth mechanism of copper thin film was put forward, and it was considered that surface functional group played an important role in the process of nucleation and in determining the properties of thin films. A high density of plasma and high free-radical content were helpful for the deposition of copper thin films.

  16. Sensitivity of Liquation Cracking to Deposition Parameters and Residual Stresses in Laser Deposited IN718 Alloy (United States)

    Zhang, Yaocheng; Yang, Li; Chen, Tingyi; Pang, Song; Zhang, Weihui


    The laser deposited IN718 alloys were fabricated with laser cladding system under different conditions to estimate the sensitivity of weld metal liquation cracking. The microstructure and the crack characterization of the laser deposited IN718 alloy were investigated, and the effect of metallurgical factors and residual stress on the crack sensitivity was analyzed. The results showed that the continuous dendritic Laves was precipitated and formed a Lave-austenite interface with ambiguous nanohardness distribution. The weld metal liquation cracking was propagated along the laser scanning direction and the buildup direction in the laser deposited IN718 alloy simultaneously, and the Nb-/Mo-riched fine granular clusters were formed in the crack surface. The precipitation amount of the coarse eutectic phases, presented as dendrite or network, was increased in the laser deposited alloy fabricated with IN718/C-Fe-Cr composite powder and slow cooling rate. The total crack length and the maximum crack length were decreased by increasing cooling rate, and the transverse residual stress was increased with increasing buildup layer number. The crack sensitivity of the laser deposited IN718 alloy was increased by the crack initiation provided by the metallurgical defects and the eutectic phases with low melting temperatures, and then, crack propagated along the continuous phase under the transverse residual stress.

  17. Sensitivity of Liquation Cracking to Deposition Parameters and Residual Stresses in Laser Deposited IN718 Alloy (United States)

    Zhang, Yaocheng; Yang, Li; Chen, Tingyi; Pang, Song; Zhang, Weihui


    The laser deposited IN718 alloys were fabricated with laser cladding system under different conditions to estimate the sensitivity of weld metal liquation cracking. The microstructure and the crack characterization of the laser deposited IN718 alloy were investigated, and the effect of metallurgical factors and residual stress on the crack sensitivity was analyzed. The results showed that the continuous dendritic Laves was precipitated and formed a Lave-austenite interface with ambiguous nanohardness distribution. The weld metal liquation cracking was propagated along the laser scanning direction and the buildup direction in the laser deposited IN718 alloy simultaneously, and the Nb-/Mo-riched fine granular clusters were formed in the crack surface. The precipitation amount of the coarse eutectic phases, presented as dendrite or network, was increased in the laser deposited alloy fabricated with IN718/C-Fe-Cr composite powder and slow cooling rate. The total crack length and the maximum crack length were decreased by increasing cooling rate, and the transverse residual stress was increased with increasing buildup layer number. The crack sensitivity of the laser deposited IN718 alloy was increased by the crack initiation provided by the metallurgical defects and the eutectic phases with low melting temperatures, and then, crack propagated along the continuous phase under the transverse residual stress.

  18. Low temperature deposition of crystalline silicon on glass by hot wire chemical vapor deposition (United States)

    Chung, Yung-Bin; Park, Hyung-Ki; Lee, Dong-Kwon; Jo, Wook; Song, Jean-Ho; Lee, Sang-Hoon; Hwang, Nong-Moon


    Although the deposition of crystalline silicon on a glass substrate has been pursued using hot wire chemical vapor deposition or plasma enhanced chemical vapor deposition for applications in flat panel displays and solar cells, the process has been only partly successful because of the inevitable formation of an amorphous incubation layer on a glass substrate. Currently, the crystalline silicon films are prepared by depositing an amorphous silicon film on a glass substrate and then crystallizing it by excimer laser annealing (ELA), metal induced crystallization or rapid thermal annealing (RTA). Here we report a new process, which can remove the amorphous incubation layer and thereby deposit crystalline silicon directly on glass using HCl. The intrinsic crystalline silicon film has a conductivity of 3.7×10 -5 Scm -1 and the n-type doped crystalline silicon film has the Hall mobility of 15.8 cm 2V -1 s -1, whose values are comparable to those prepared by ELA and RTA, respectively.

  19. In-situ CdS/CdTe Heterojuntions Deposited by Pulsed Laser Deposition

    KAUST Repository

    Avila-Avendano, Jesus


    In this paper pulsed laser deposition (PLD) methods are used to study p-n CdTe/CdS heterojunctions fabricated in-situ. In-situ film deposition allows higher quality p-n interfaces by minimizing spurious contamination from the atmosphere. Morphologic and structural analyses were carried for CdTe films deposited on various substrates and different deposition conditions. The electrical characteristics and performance of the resulting p-n heterojunctions were studied as function of substrate and post-deposition anneal temperature. In-situ growth results on diodes with a rectification factor of ~ 105, an ideality factor < 2, and a reverse saturation current ~ 10-8 A. The carrier concentration in the CdTe film was in the range of ~ 1015 cm-3, as measured by C-V methods. The possible impact of sulfur diffusion from the CdS into the CdTe film is also investigated using High Resolution Rutherford Back-Scattering.

  20. Selective deposition contact patterning using atomic layer deposition for the fabrication of crystalline silicon solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Young Joon [Graduate School of Energy Science and Technology, Chungnam National University, Yuseong-gu, Daejeon 305-764 (Korea, Republic of); Shin, Woong-Chul [NCD Co. Ltd., Yuseong-gu, Daejeon 305-509 (Korea, Republic of); Chang, Hyo Sik, E-mail: [Graduate School of Energy Science and Technology, Chungnam National University, Yuseong-gu, Daejeon 305-764 (Korea, Republic of)


    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 Al{sub 2}O{sub 3}, we produced local contacts without photolithography or any laser-based processes. Passivated emitter and rear-contact solar cells passivated with ozone-based Al{sub 2}O{sub 3} 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-Al{sub 2}O{sub 3} film. • Ozone-based Al{sub 2}O{sub 3} thin film was selectively deposited onto patterned silicon. • Selective deposition contact patterning method can increase cell-efficiency by 0.7%.

  1. Influence of Deposition Condition on Y2O3 Coatings Produced by Pulsed Electrophoretic Deposition

    Directory of Open Access Journals (Sweden)

    Hidetoshi Miyazaki


    Full Text Available Y2O3 nanoparticle suspension aqueous solution was prepared using citric acid. Then, Y2O3 film was deposited using this solution with pulsed electrophoretic deposition (EPD. A dense Y2O3 film of 25.7 μm thickness was obtained with deposition conditions of 0.5 wt% Y2O3 concentration, bias voltage of 0.5 V, and bias frequency of 1 kHz. The respective resistivities of the as-deposited film and films heat-treated at 200°C and 400°C were 2.84 × 103 Ω·cm, 5.36 × 104 Ω·cm, and 2.05 × 106 Ω·cm. A 59.8 μm thick dense Y2O3 film was obtained using two-step deposition with change of the bias voltage: a first step of 0.5 V and a second step of 2.0 V.

  2. Methanol electro-oxidation catalyzed by platinum deposited on various substrates using Electrochemical Atomic Layer Deposition (ECALD)

    CSIR Research Space (South Africa)

    Louw, EK


    Full Text Available , & Srinivasan, 1997). 22 2.5.3 Ion beam deposition Ion plating uses concurrent or periodic energetic particle bombardment of the depositing film to modify and control the composition and properties of the deposited film and to improve surface coverage...

  3. Al2O3 coatings against high temperature corrosion deposited by metal-organic low pressure chemical vapour deposition

    NARCIS (Netherlands)

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


    Metal-organic chemical vapour deposition of thin amorphous films of Al2O3 on steels was performed at low pressure. Aluminium tri-sec-butoxide (ATSB) was used as a precursor. The effects of the deposition temperature (200–380 °C), the deposition pressure (0.17–1.20 kPa) and the ATSB concentration

  4. CMAS Interactions with Advanced Environmental Barrier Coatings Deposited via Plasma Spray- Physical Vapor Deposition (United States)

    Harder, B. J.; Wiesner, V. L.; Zhu, D.; Johnson, N. S.


    Materials for advanced turbine engines are expected to have temperature capabilities in the range of 1370-1500C. At these temperatures the ingestion of sand and dust particulate can result in the formation of corrosive glass deposits referred to as CMAS. The presence of this glass can both thermomechanically and thermochemically significantly degrade protective coatings on metallic and ceramic components. Plasma Spray- Physical Vapor Deposition (PS-PVD) was used to deposit advanced environmental barrier coating (EBC) systems for investigation on their interaction with CMAS compositions. Coatings were exposed to CMAS and furnace tested in air from 1 to 50 hours at temperatures ranging from 1200-1500C. Coating composition and crystal structure were tracked with X-ray diffraction and microstructure with electron microscopy.

  5. Hardness Enhancement of STS304 Deposited with Yttria Stabilized Zirconia by Aerosol Deposition Method

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Il-Ho; Park, Chun-Kil; Kim, Hyung Sun; Jeong, Dea-Yong [Inha University, Incheon (Korea, Republic of); Lee, Yong-Seok [Sodoyeon Co., Yeoju (Korea, Republic of); Kong, Young-Min [University of Ulsan, Ulsan (Korea, Republic of); Kang, Kweon Ho [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)


    To improve the surface hardness of the STS304, Yttria stabilized zirconia (YSZ) films with nano-sized grain were deposited by an aerosol-deposition (AD) method. Coating layers showed dense structure and had -5µm thickness. When 3 mol% YSZ powders with tetragonal phase were deposited on STS304 substrate, tetragonal structure was transformed to cubic structure due to the high impact energy during the AD process. At the same time, strong impact by YSZ particles allowed the austenite phase in STS304 to be transformed into martensite phase. Surface hardness measured with nano indentor showed that YSZ coated film had 11.5 GPa, which is larger value than 7 GPa of STS304.

  6. Low-Temperature Deposition of Zinc Oxide Film by Plasma-Assisted Mist Chemical Vapor Deposition (United States)

    Takenaka, Kosuke; Okumura, Yusuke; Setsuhara, Yuichi


    Zinc oxide (ZnO) film deposition using a plasma-assisted mist chemical vapor deposition (CVD) with an inductively-coupled plasma source has been performed and the effects of the plasma exposure on film properties have been investigated with oxygen mixture ratio as a parameter. With increasing oxygen mixture ratio to Ar+O2(10%), the X-ray diffraction (XRD) results showed evident peaks of ZnO(0002), indicating that highly c-axis-oriented films were grown at low substrate temperatures below 200 °C. The deposition rate of ZnO films was as high as 100 nm/min. ZnO films with an optical transmittance of 75% for the visible region and a band gap energy of 3.32 eV have been obtained by using plasma-assisted mist CVD.

  7. Aerosol deposition in the human respiratory tract. I. Experimental procedure and total deposition

    Energy Technology Data Exchange (ETDEWEB)

    Altshuler, B.; Yarmus, L.; Palmes, E.D.; Nelson, N.


    Three volunteers were exposed via mouth inhalation to triphenyl phosphate (non-hygroscopic). Particle sizes tested ranged from 0.14 to 3.2 (6 homogenous steps). Deposition curves show minimum retention of 0.4 particle size. Brownian motion (random impact with gas) varies by d/sup -//sup 1/2; settling effect and impact effect vary by d/sup 2/ so minimum deposition is where these three processes counteract each other. Slower, deeper breathing resulted in greater deposition; differences were greater with larger particles, because settling and impaction vary with first power of time and Brownian varies with square root of time. Pneumoconiosis-producing dusts act on deep pulmonary tissues whereas major cancer producers act on the bronchi.

  8. MEAD Marine Effects of Atmospheric Deposition (United States)

    Jickells, T.; Spokes, L.


    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

  9. Acidic Depositions: Effects on Wildlife and Habitats (United States)


    The phenomenon of 'acid rain' is not new; it was recognized in the mid-1800s in industrialized Europe. In the 1960s a synthesis of information about acidification began in Europe, along with predictions of ecological effects. In the U.S. studies of acidification began in the 1920s. By the late 1970s research efforts in the U.S. and Canada were better coordinated and in 1980 a 10-year research program was undertaken through the National Acid Precipitation Assessment Plan (NAPAP) to determine the causes and consequences of acidic depositions. Much of the bedrock in the northeastern U.S. and Canada contains total alkalinity of 20 kg/ha/yr of wet sulphate depositions and are vulnerable to acidifying processes. Acidic depositions contribute directly to acidifying processes of soil and soil water. Soils must have sufficient acid-neutralizing capacity or acidity of soil will increase. Natural soil-forming processes that lead to acidification can be accelerated by acidic depositions. Long-term effects of acidification are predicted, which will reduce soil productivity mainly through reduced availability of nutrients and mobilization of toxic metals. Severe effects may lead to major alteration of soil chemistry, soil biota, and even loss of vegetation. Several species of earthworms and several other taxa of soil-inhabiting invertebrates, which are important food of many vertebrate wildlife species, are affected by low pH in soil. Loss of canopy in declining sugar maples results in loss of insects fed on by certain neotropical migrant bird species. No definitive studies categorically link atmospheric acidic depositions with direct or indirect effects on wild mammals. Researchers have concentrated on vegetative and aquatic effects. Circumstantial evidence suggests that effects are probable for certain species of aquatic-dependent mammals (water shrew, mink, and otter) and that these species are at risk from the loss of foods or contamination of these foods by metals

  10. The interaction of sleep and amyloid deposition on cognitive performance. (United States)

    Molano, Jennifer R V; Roe, Catherine M; Ju, Yo-El S


    Sleep difficulties are emerging as a risk factor for dementia. This study examined the effect of sleep and amyloid deposition on cognitive performance in cognitively normal adults. Sleep efficiency was determined by actigraphy. Cerebrospinal fluid Aβ42 levels sleep efficiency and amyloid deposition status was a significant predictor of memory performance as measured by total Selective Reminding Test scores. While Trail Making Test B performance was worse in those with amyloid deposition, sleep measures did not have an additive effect. In this study, amyloid deposition was associated with worse cognitive performance, and poor sleep efficiency specifically modified the effect of amyloid deposition on memory performance. © 2016 European Sleep Research Society.

  11. Deposit Insurance and Bank Liquidity: Does Ownership Structure Matter?

    Directory of Open Access Journals (Sweden)

    Irwan Trinugroho


    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.

  12. Seismic stratigraphy and depositional history of late Quaternary deposits at the eastern Yellow Sea shelf (United States)

    Yoo, Dong-Geun; Lee, Gwang-Soo; Kim, Gil-Young; Chang, Se-Won; Kim, Kyoung-Jin


    The late Quaternary stratigraphy and sedimentation at the eastern Yellow Sea shelf was studied using a dense network of high-resolution, single-channel seismic reflection profiles and sediment data. The shelf sequence in this area consists of six seismic units formed since the LGM. During the LGM, the study area was completely exposed, resulting in subaerial erosion associated with paleo-channel incision by the Huanghe and Korean Rivers. As the shelf was flooded, the incised channels were backfilled fluvial or coastal sediments, forming incised channel-fill deposits (SU1). The paleo-river may have supplied abundant terrigenous sediments to the study area around the paleo-river mouth and adjacent area. These sediments were trapped within the paleo-estuary and formed SU2, regarded as an estuarine deposit. Two types of serial sand ridges (SU3 and SU5) which correspond to transgressive deposits developed. SU3 on the southern part, west of Jeju Island (80 110 m deep) is regarded as a moribund-type mainly formed during the early to middle stage of transgression. These are thought to have ceased growing and remobilizing. In contrast, SU5 (occurring 30 50 m deep off the Korean Peninsula) is generally regarded as active sand ridges deposited during the late stage of transgression and is partly modified by modern tidal currents. As the transgression continued, the near-surface sediments were reworked and redistributed by shelf erosion, resulting in a thin veneer of transgressive sands (SU4). The uppermost unit (SU6) formed the Heuksan Mud Belt (HMB), which is one of the most prominent mud deposits in the Yellow Sea. The lower part of the HMD corresponds to shelf-mud deposited during the late stage of transgression, whereas the upper part consists of a recent shelf-delta developed after the highstand sea level at about 7 ka BP.

  13. Bulk sulfur (S) deposition in China (United States)

    Liu, Lei; Zhang, Xiuying; Wang, Shanqian; Zhang, Wuting; Lu, Xuehe


    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.

  14. Impediments to recovery from acid deposition (United States)

    Watmough, Shaun A.; Eimers, Catherine; Baker, Scott


    In response to large reductions in sulphur (S) emissions over the past 30 years, sulphate (SO42-) concentrations in precipitation at Plastic Lake in south-central Ontario, Canada, have declined by more than 70%. More recent decreases in NOx emissions have similarly led to a reduction in nitrate deposition (NO3-) and consequently the pH of bulk precipitation has increased by approximately 0.8 pH units since 1980. Despite the large decrease in acidic deposition, chemical recovery of the streams, as measured by an increase in pH and decrease in aluminum (Al), has been much less than expected, primarily due to losses of base cations from the shallow, base-poor soils. While nitrogen (N) is almost totally retained within the terrestrial catchment, S export continues to exceed inputs measured in bulk deposition and during the early part of the record approximately 70% of the anions in streams were buffered by calcium (Ca2+) and magnesium (Mg2+) compared with only 60% in 2011/12. In the wetland-draining stream (PC1), peak depressions in stream pH and peaks in SO42- and Al concentration in the fall are significantly positively correlated with annual drought days defined as the number of days when stream flow ceases. Even though reductions in SO2 and NOx emissions in Canada have resulted in large improvements in precipitation chemistry, the combined influence of soil acidification and climate-mediated biogeochemical processes occurring in wetlands cause acidification-related issues to persist. Forecasting the longer-term response of soils and surface waters in light of these observations is required to fully assess the need for further emission reductions.

  15. Orientation specific deposition of mesoporous particles

    Directory of Open Access Journals (Sweden)

    Tomas Kjellman


    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.

  16. Atomic layer deposition of nanostructured materials

    CERN Document Server

    Pinna, Nicola


    Atomic layer deposition, formerly called atomic layer epitaxy, was developed in the 1970s to meet the needs of producing high-quality, large-area fl at displays with perfect structure and process controllability. Nowadays, creating nanomaterials and producing nanostructures with structural perfection is an important goal for many applications in nanotechnology. As ALD is one of the important techniques which offers good control over the surface structures created, it is more and more in the focus of scientists. The book is structured in such a way to fi t both the need of the expert reader (du

  17. Iron-sulfide crystals in probe deposits

    DEFF Research Database (Denmark)

    Laursen, Karin; Frandsen, Flemming


    : (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......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...

  18. Fabrication of Micro Components by Electrochemical Deposition

    DEFF Research Database (Denmark)

    Tang, Peter Torben

    . The principles of general electrochemistry, electroplating, alloy plating, pulse plating and electroless plating are discussed, as well as measurement methods and improve-ment of important properties such as internal stress, material distribution, mechanical properties and magnetic properties. The use......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...... commercial processes for selective etching of copper and gold and for electroplating of gold and indium....

  19. Solid Organic Deposition During Gas Injection Studies

    DEFF Research Database (Denmark)

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


    Recently a series of first contact miscibility (swelling) experiments have been performed on undersaturated light and heavy oils using LPG rich and methane rich injection gases, in which solid organic deposition was observed. A compositional gradient in the oils during the gas injection process...... was also evident as oil fractions expelled from the top to bottom of the PVT cell were observed to vary in density, molecular weight, as well as darkness of color. The change in stability of the oil samples before and after the contact with gas was analyzed using flocculation threshold titration...

  20. Alaska's rare earth deposits and resource potential (United States)

    Barker, James C.; Van Gosen, Bradley S.


    Alaska’s known mineral endowment includes some of the largest and highest grade deposits of various metals, including gold, copper and zinc. Recently, Alaska has also been active in the worldwide search for sources of rare earth elements (REE) to replace exports now being limitedby China. Driven by limited supply of the rare earths, combined with their increasing use in new ‘green’ energy, lighting, transportation, and many other technological applications, the rare earth metals neodymium, europium and, in particular, the heavy rare earth elements terbium, dysprosium and yttrium are forecast to soon be in critical short supply (U.S. Department of Energy, 2010).

  1. Paleoclimatic signature in terrestrial flood deposits. (United States)

    Koltermann, C E; Gorelick, S M


    Large-scale process simulation was used to reconstruct the geologic evolution during the past 600,000 years of an alluvial fan in northern California. In order to reproduce the sedimentary record, the simulation accounted for the dynamics of river flooding, sedimentation, subsidence, land movement that resulted from faulting, and sea level changes. Paleoclimatic trends induced fluctuations in stream flows and dominated the development of the sedimentary deposits. The process simulation approach serves as a quantitative means to explore the genesis of sedimentary architecture and its link to past climatic conditions and fault motion.

  2. Development of Mouse Lung Deposition Models (United States)


    deposition calculations in each strain of mouse: first by 3/1)TLC/FRC( , where FRC is the functional residual capacity or lung volume at rest and TLC is lung capacity , to adjust airway dimensions to rest conditions, and second by 3/1T )2/V1( + , where TV is the tidal volume , to account for...geometry that was previously developed for humans, rats, and rhesus monkeys [6], [7]. Inputs to the model included lung geometry and volumes , and

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

    DEFF Research Database (Denmark)

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


    . This configuration enables a gentle treatment of sensitive materials like low-density polyethylene foils and biodegradable materials. SiOx coatings deposited in the novel setup were compared with other state of the art plasma coatings and were found to possess equally good or better barrier properties. The barrier...... effect of single-layer coatings deposited under different reaction conditions was studied. The coating thickness and the carbon content in the coatings were found to be the critical parameters for the barrier property. The novel barrier coating was applied on different polymeric materials...

  4. Nitrogen deposition threatens species richness of grasslands across Europe

    Energy Technology Data Exchange (ETDEWEB)

    Stevens, C.J. [Lancaster Environment Centre, Lancaster University, Lancaster LA1 4YQ (United Kingdom); Gowing, D.J.G. [Department of Life Sciences, The Open University, Walton Hall, Milton Keynes MK7 6AA (United Kingdom); Dupre, C.; Diekmann, M. [Institute of Ecology, FB 2, University of Bremen, Leobener Str., DE-28359 Bremen (Germany); Dorland, E. [Section of Landscape Ecology, Department of Geobiology, Utrecht University, P.O. Box 80084, 3508 TB Utrecht (Netherlands); Gaudnik, C.; Alard, D.; Corcket, E. [University of Bordeaux 1. UMR INRA 1202 Biodiversity, Genes and Communities, Equipe Ecologie des Communautes, Batiment B8 - Avenue des Facultes, F-33405 Talence (France); Bleeker, A. [Department of Air Quality and Climate Change, Energy Research Centre of the Netherlands, P.O. Box 1, 1755 ZG Petten (Netherlands); Bobbink, R. [B-WARE Research Centre, Radboud University, P.O. Box 9010, 6525 ED Nijmegen (Netherlands); Fowler, D. [NERC Centre for Ecology and Hydrology, Bush Estate, Penicuik, Midlothian EH26 0QB (United Kingdom); Mountford, J.O. [NERC Centre for Ecology and Hydrology, MacLean Building, Benson Lane, Crowmarsh Gifford, Wallingford, Oxfordshire OX10 8BB (United Kingdom); Vandvik, V. [Department of Biology, University of Bergen, Box 7800, N-5020 Bergen (Norway); Aarrestad, P.A. [Norwegian Institute for Nature Research, NO-7485 Trondheim (Norway); Muller, S. [Laboratoire des Interactions Ecotoxicologie, Biodiversite et Ecosystemes LIEBE, UMR CNRS 7146, U.F.R. Sci. F.A., Campus Bridoux, Universite Paul Verlaine, Avenue du General Delestraint, F-57070 Metz (France); Dise, N.B. [Department of Environmental and Geographical Science, Manchester Metropolitan University, Manchester M1 5GD (United Kingdom)


    Evidence from an international survey in the Atlantic biogeographic region of Europe indicates that chronic nitrogen deposition is reducing plant species richness in acid grasslands. Across the deposition gradient in this region (2-44 kg N ha{sup -1} yr{sup -1}) species richness showed a curvilinear response, with greatest reductions in species richness when deposition increased from low levels. This has important implications for conservation policies, suggesting that to protect the most sensitive grasslands resources should be focussed where deposition is currently low. Soil pH is also an important driver of species richness indicating that the acidifying effect of nitrogen deposition may be contributing to species richness reductions. The results of this survey suggest that the impacts of nitrogen deposition can be observed over a large geographical range. Atmospheric nitrogen deposition is reducing biodiversity in grasslands across Europe.

  5. Vapor-deposited porous films for energy conversion (United States)

    Jankowski, Alan F.; Hayes, Jeffrey P.; Morse, Jeffrey D.


    Metallic films are grown with a "spongelike" morphology in the as-deposited condition using planar magnetron sputtering. The morphology of the deposit is characterized by metallic continuity in three dimensions with continuous and open porosity on the submicron scale. The stabilization of the spongelike morphology is found over a limited range of the sputter deposition parameters, that is, of working gas pressure and substrate temperature. This spongelike morphology is an extension of the features as generally represented in the classic zone models of growth for physical vapor deposits. Nickel coatings were deposited with working gas pressures up 4 Pa and for substrate temperatures up to 1000 K. The morphology of the deposits is examined in plan and in cross section views with scanning electron microscopy (SEM). The parametric range of gas pressure and substrate temperature (relative to absolute melt point) under which the spongelike metal deposits are produced appear universal for other metals including gold, silver, and aluminum.

  6. Mapping of depositional and non-depositional areas in Salinas, California streams with concurrent pyrethroid and benthic macroinvertebrate assessments. (United States)

    Hall, Lenwood W; Anderson, Ronald D; Killen, William D


    This study used sediment mapping to determine the spatial extent of depositional and non-depositional areas in the wetted stream bed of four urban streams in Salinas, California. After the stream mapping was completed, 8 pyrethroids were analytically measured from randomly selected sites in 12 depositional and 12 non-depositional areas in the four Salinas streams. Benthic macroinvertebrate samples were collected and identified from depositional and non-depositional areas where pyrethroids were measured. In addition, physical habitat was also evaluated at each site where benthic communities were collected. Based on a random sampling design, 24 % of the 96 sediment sampling sites in the Salinas streams were classified as predominately depositional areas. Mean total pyrethroid concentrations were approximately 2× to 61× times higher in depositional areas of the Salinas streams when compared to non-depositional areas. Physical habitat scores from the 12 depositional and 12 non-depositional areas in the Salinas stream sites were extremely low compared with other California streams thus demonstrating that impaired physical habitat is a critical stressor in these streams. Approximately 6,300 individual macroinvertebrates were picked and identified from 70 taxa from the 24 Salinas stream sites. The most dominant taxa collected were all considered tolerant of environmental stressors and dominant taxa from both depositional and non-deposition areas were similar. Ten different benthic metrics for the Salinas streams were similar for the depositional areas, where pyrethroid concentrations consistently exceeded laboratory based toxicity thresholds, and non-depositional areas where pyrethroid concentrations were much lower. These results suggest that factors other than pyrethroids are responsible for impacting resident benthic communities in these urban Salinas streams.

  7. Large-scale internal structure in volcanogenic breakout flood deposits: Extensive GPR survey on volcaniclastic deposits (United States)

    Kataoka, K.; Gomez, C. A.


    Large-scale outburst floods from volcanic lakes such as caldera lakes or volcanically dammed river-valleys tend to be voluminous with total discharge of > 1-10s km3 and peak discharge of >10000s to 100000s m3 s-1. Such a large flood can travel long distance and leave sediments and bedforms/landforms extensively with large-scale internal structures, which are difficult to assess from single local sites. Moreover, the sediments and bedforms/landforms are sometimes untraceable, and outcrop information obtained by classical geological and geomorphological field surveys is limited to the dissected/terraced parts of fan body, road cuts and/or large quarries. Therefore, GPR (Ground Penetrating Radar), using the properties of electromagnetic waves' propagation through media, seems best adapted for the appraisal of large-scale subsurface structures. Recently, studies on GPR applications to volcanic deposits have successfully captured images of lava flows and volcaniclastic deposits and proved the usefulness of this method even onto the volcanic areas which often encompass complicated stratigraphy and structures with variable material, grainsize, and ferromagnetic content. Using GPR, the present study aims to understand the large-scale internal structures of volcanogenic flood deposits. The survey was carried out over two volcanogenic flood fan (or apron) sediments in northeast Japan, at Numazawa and Towada volcanoes. The 5 ka Numazawa flood deposits in the Tadami river catchment that has been emplaced by a breakout flood from ignimbrite-dammed valley leaving pumiceous gravelly sediments with meter-sized boulders in the flow path. At Towada volcano, a comparable flood event originating from a breach in the caldera rim emplaced the 13-15 ka Sanbongi fan deposits in the Oirase river valley, which is characterized by a bouldery fan deposits. The GPR data was collected following 200 to 500 m long lateral and longitudinal transects, which were captured using a GPR Pulse

  8. A 20-year simulated climatology of global dust aerosol deposition. (United States)

    Zheng, Yu; Zhao, Tianliang; Che, Huizheng; Liu, Yu; Han, Yongxiang; Liu, Chong; Xiong, Jie; Liu, Jianhui; Zhou, Yike


    Based on a 20-year (1991-2010) simulation of dust aerosol deposition with the global climate model CAM5.1 (Community Atmosphere Model, version 5.1), the spatial and temporal variations of dust aerosol deposition were analyzed using climate statistical methods. The results indicated that the annual amount of global dust aerosol deposition was approximately 1161±31Mt, with a decreasing trend, and its interannual variation range of 2.70% over 1991-2010. The 20-year average ratio of global dust dry to wet depositions was 1.12, with interannual variation of 2.24%, showing the quantity of dry deposition of dust aerosol was greater than dust wet deposition. High dry deposition was centered over continental deserts and surrounding regions, while wet deposition was a dominant deposition process over the North Atlantic, North Pacific and northern Indian Ocean. Furthermore, both dry and wet deposition presented a zonal distribution. To examine the regional changes of dust aerosol deposition on land and sea areas, we chose the North Atlantic, Eurasia, northern Indian Ocean, North Pacific and Australia to analyze the interannual and seasonal variations of dust deposition and dry-to-wet deposition ratio. The deposition amounts of each region showed interannual fluctuations with the largest variation range at around 26.96% in the northern Indian Ocean area, followed by the North Pacific (16.47%), Australia (9.76%), North Atlantic (9.43%) and Eurasia (6.03%). The northern Indian Ocean also had the greatest amplitude of interannual variation in dry-to-wet deposition ratio, at 22.41%, followed by the North Atlantic (9.69%), Australia (6.82%), North Pacific (6.31%) and Eurasia (4.36%). Dust aerosol presented a seasonal cycle, with typically strong deposition in spring and summer and weak deposition in autumn and winter. The dust deposition over the northern Indian Ocean exhibited the greatest seasonal change range at about 118.00%, while the North Atlantic showed the lowest seasonal

  9. Study of nozzle deposit formation mechanism for direct injection gasoline engines; Chokufun gasoline engine yo nozzle no deposit seisei kaiseki

    Energy Technology Data Exchange (ETDEWEB)

    Kinoshita, M.; Saito, A. [Toyota Central Research and Development Labs., Inc., Aichi (Japan); Matsushita, S. [Toyota Motor Corp., Aichi (Japan); Shibata, H. [Nippon Soken, Inc., Tokyo (Japan); Niwa, Y. [Denso Corp., Aichi (Japan)


    Nozzles in fuel injectors for direct injection gasoline engines are exposed to high temperature combustion gases and soot. In such a rigorous environment, it is a fear that fuel flow rate changes in injectors by deposit formation on nozzles. Fundamental factors of nozzle deposit formation were investigated through injector bench tests and engine dynamometer tests. Deposit formation processes were observed by SEM through engine dynamometer tests. The investigation results reveal nozzle deposit formation mechanism and how to suppress the deposit. 4 refs., 8 figs., 3 tabs.

  10. Colloidal Drop Deposition on Porous Substrates (United States)

    Sun, Ying; Pack, Min; Hu, Han; Kim, Dong-Ook; Yang, Xin


    Printable electronics and in particular paper and textile-based electronics have fueled research in inkjet printing on porous substrates. On nonporous substrates, the particle motion of the particles and evaporation of the solvent are the two main mechanisms that drive the final deposition morphology. For porous substrates another factor, mainly infiltration, adds a layer of complexity to the deposition patterns that has not yet been elucidated in literature. In this study, a high-speed camera was used to capture the imbibition of picoliter-sized polystyrene nanoparticles in water droplets into nano-porous anodic aluminum oxide substrates of various porosities and wettabilities. For water, the infiltration rate is much faster than both evaporation and particle motion and thus when the substrate fully imbibes the droplet, the well-known ``coffee ring'' is suppressed. However, when a residual droplet forms upon the termination of the infiltration regime, the competing particle motion and evaporation regimes, tP and tEI respectively, define the critical time scales for which the coffee ring will be formed (tP /tEI 1). National Science Foundation under Grant No. CMMI-1401438.

  11. Investigation on characterization of Ereen coal deposit

    Directory of Open Access Journals (Sweden)

    S. Jargalmaa


    Full Text Available The Ereen coal deposit is located 360 km west from Ulaanbaatar and 95 km from Bulgan town. The coal reserve of this deposit is approximately 345.2 million tons. The Ereen coal is used directly for the Erdenet power plant for producing of electricity and heat. The utilization of this coal for gas and liquid product using gasification and pyrolysis is now being considered. The proximate and ultimate analysis show that the Ereen coal is low rank D mark hard coal, which corresponds to subbituminous coal. The SEM images of initial coal sample have compact solid pieces. The SEM image of carbonized and activated carbon samples are hard material with high developed macro porosity structure. The SEM images of hard residue after thermal dissolution in autoclave characterizes hard pieces with micro porous structure in comparison with activated carbon sample. The results of the thermal dissolution of Ereen coal in tetralin with constant weight ratio between coal and tetralin (1:1.8 at the 450ºC show that 38% of liquid product can be obtained by thermal decomposition of the COM (coal organic matter.Mongolian Journal of Chemistry 16 (42, 2015, 18-21

  12. LBM simulations on agglomerate transport and deposition (United States)

    Dietzel, Mathias; Sommerfeld, Martin


    Agglomerated particles appear in various technical applications of the process industry in form of products, waste or contamination. Desired or undesired, these complex-structured particles need to be handled, involving transportation and separation processes, agglomerate growth and breakup as well as stabilization techniques. Both, fundamental research and industry have a strong demand of knowledge about agglomerate behavior. Numerical simulations are capable to provide an addition or even substitution of experimental data if accessibility is limited or too expensive. In this work, the Lattice Boltzmann Method (LBM) is used to perform high resolution simulations of agglomerates to investigate agglomerate transport and deposition depending on flow conditions and agglomerate structure. This paper presents an approach to generate and characterize three-dimensional agglomerates and to predict the flow around these aggregated structures using a 3D multi-scale LBM. The considered agglomerates are composed of spherical primary particles which are connected to each other by rigid joints. The characterization of the agglomerates is done using common equivalent diameters as well as the fractal dimension and the convex hull. Simulating the flow field around the agglomerates leads to the forces and torques acting on the aggregates. From that the drag, lift and torque coefficients can be determined and their dependencies on agglomerate structure, orientation and flow conditions can be estimated. The overall aim is modeling and simulating transport and deposition processes of agglomerated particles.

  13. Atmosfærisk deposition 2000

    DEFF Research Database (Denmark)

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

    af nedbør, forskelle i afstand til områder med høje emissioner i den nordlige del af det europæiske kontinent og intensitet af husdyrbrug og dermed ammoniak- emissionen på mere lokal skala. Depositionen pr. areal-enhed er generelt højere til land end til vand, hvilket primært skyldes deposition af...... ikke afspejler det generelle billede for hele Danmark. Usikkerhed på beregningerne Usikkerheden på beregning af deposition af kvælstof til de danske land- og vandområder er meget svær at bestemme. Med udgangspunkt i sammenligning mellem modelberegningerne og målingerne estimeres den samlede usikkerhed...... i beregningerne af kvælstofdepositionen til land til 50%. Anlægges igen en forsigtig betragtning kan usikkerheden i beregningerne for Kattegat estimeres til ca. 30%, hvilket også skønnes at gælde for resten af de Indre Danske Farvande. For den danske del af Nordsøen har vi ikke måledata...

  14. Vacuum deposition onto webs, films and foils

    CERN Document Server

    Bishop, Charles A


    Roll-to-roll vacuum deposition is the technology that applies an even coating to a flexible material that can be held on a roll and provides a much faster and cheaper method of bulk coating than deposition onto single pieces or non-flexible surfaces, such as glass. This technology has been used in industrial-scale applications for some time, including a wide range of metalized packaging (e.g. snack packets). Its potential as a high-speed, scalable process has seen an increasing range of new products emerging that employ this cost-effective technology: solar energy products are moving from rigid panels onto flexible substrates, which are cheaper and more versatile; in a similar way, electronic circuit 'boards' can be produced on a flexible polymer, creating a new range of 'flexible electronics' products; and, flexible displays are another area of new technology in vacuum coating, with flexible display panels and light sources emerging. Charles Bishop has written this book to meet the need he identified, as a t...

  15. Thin film deposition using rarefied gas jet (United States)

    Pradhan, Sahadev, , Dr.


    The rarefied gas jet of aluminium is studied at Mach number Ma = (Uj /√{ kbTj / mg }) in the range .01 physical vapor deposition (PVD) process for the development of the highly oriented pure metallic aluminum thin film with uniform thickness and strong adhesion on the surface of the substrate in the form of ionic plasma, so that the substrate can be protected from corrosion and oxidation and thereby enhance the lifetime and safety, and to introduce the desired surface properties for a given application. Here, H is the characteristic dimension, U_j and T_j are the jet velocity and temperature, n_d is the number density of the jet, m and d are the molecular mass and diameter, and kbis the Boltzmann constant. An important finding is that the capture width (cross-section of the gas jet deposited on the substrate) is symmetric around the centerline of the substrate, and decreases with increased Mach number due to an increase in the momentum of the gas molecules. DSMC simulation results reveals that at low Knudsen number ((Kn=0.01); shorter mean free paths), the atoms experience more collisions, which direct them toward the substrate. However, the atoms also move with lower momentum at low Mach number, which allows scattering collisions to rapidly direct the atoms to the substrate.

  16. Multi-Constituent Simulation of Thrombus Deposition (United States)

    Wu, Wei-Tao; Jamiolkowski, Megan A.; Wagner, William R.; Aubry, Nadine; Massoudi, Mehrdad; Antaki, James F.


    In this paper, we present a spatio-temporal mathematical model for simulating the formation and growth of a thrombus. Blood is treated as a multi-constituent mixture comprised of a linear fluid phase and a thrombus (solid) phase. The transport and reactions of 10 chemical and biological species are incorporated using a system of coupled convection-reaction-diffusion (CRD) equations to represent three processes in thrombus formation: initiation, propagation and stabilization. Computational fluid dynamic (CFD) simulations using the libraries of OpenFOAM were performed for two illustrative benchmark problems: in vivo thrombus growth in an injured blood vessel and in vitro thrombus deposition in micro-channels (1.5 mm × 1.6 mm × 0.1 mm) with small crevices (125 μm × 75 μm and 125 μm × 137 μm). For both problems, the simulated thrombus deposition agreed very well with experimental observations, both spatially and temporally. Based on the success with these two benchmark problems, which have very different flow conditions and biological environments, we believe that the current model will provide useful insight into the genesis of thrombosis in blood-wetted devices, and provide a tool for the design of less thrombogenic devices.

  17. Characterization of Metalorganic Chemical Vapor Deposition (United States)

    Jesser, W. A.


    A series of experimental and numerical investigations to develop a more complete understanding of the reactive fluid dynamics of chemical vapor deposition were conducted. In the experimental phases of the effort, a horizontal CVD reactor configuration was used for the growth of InP at UVA and for laser velocimetry measurements of the flow fields in the reactor at LaRC. This horizontal reactor configuration was developed for the growth of III-V semiconductors and has been used by our research group in the past to study the deposition of both GaAs and InP. While the ultimate resolution of many of the heat and mass transport issues will require access to a reduced-gravity environment, the series of groundbased research makes direct contributions to this area while attempting to answer the design questions for future experiments of how low must gravity be reduced and for how long must this gravity level be maintained to make the necessary measurements. It is hoped that the terrestrial experiments will be useful for the design of future microgravity experiments which likely will be designed to employ a core set of measurements for applications in the microgravity environment such as HOLOC, the Fluid Physics/Dynamics Facility, or the Schlieren photography, the Laser Imaging Velocimetry and the Laser Doppler Velocimetry instruments under development for the Advanced Fluids Experiment Module.

  18. Aerosol deposition in bends with turbulent flow

    Energy Technology Data Exchange (ETDEWEB)

    McFarland, A.R.; Gong, H.; Wente, W.B. [Texas A& M Univ., College Station, TX (United States)] [and others


    The losses of aerosol particles in bends were determined numerically for a broad range of design and operational conditions. Experimental data were used to check the validity of the numerical model, where the latter employs a commercially available computational fluid dynamics code for characterizing the fluid flow field and Lagrangian particle tracking technique for characterizing aerosol losses. Physical experiments have been conducted to examine the effect of curvature ratio and distortion of the cross section of bends. If it curvature ratio ({delta} = R/a) is greater than about 4, it has little effect on deposition, which is in contrast with the recommendation given in ANSI N13.1-1969 for a minimum curvature ratio of 10. Also, experimental results show that if the tube cross section is flattened by 25% or less, the flattening also has little effect on deposition. Results of numerical tests have been used to develop a correlation of aerosol penetration through a bend as a function of Stokes number (Stk), curvature ratio ({delta}) and the bend angle ({theta}). 17 refs., 10 figs., 2 tabs.

  19. Deposition and biokinetics of inhaled nanoparticles (United States)


    Particle biokinetics is important in hazard identification and characterization of inhaled particles. Such studies intend to convert external to internal exposure or biologically effective dose, and may help to set limits in that way. Here we focus on the biokinetics of inhaled nanometer sized particles in comparison to micrometer sized ones. The presented approach ranges from inhaled particle deposition probability and retention in the respiratory tract to biokinetics and clearance of particles out of the respiratory tract. Particle transport into the blood circulation (translocation), towards secondary target organs and tissues (accumulation), and out of the body (clearance) is considered. The macroscopically assessed amount of particles in the respiratory tract and secondary target organs provides dose estimates for toxicological studies on the level of the whole organism. Complementary, microscopic analyses at the individual particle level provide detailed information about which cells and subcellular components are the target of inhaled particles. These studies contribute to shed light on mechanisms and modes of action eventually leading to adverse health effects by inhaled nanoparticles. We review current methods for macroscopic and microscopic analyses of particle deposition, retention and clearance. Existing macroscopic knowledge on particle biokinetics and microscopic views on particle organ interactions are discussed comparing nanometer and micrometer sized particles. We emphasize the importance for quantitative analyses and the use of particle doses derived from real world exposures. PMID:20205860

  20. On the dry deposition of submicron particles

    Energy Technology Data Exchange (ETDEWEB)

    Wesely, M. L.


    The air-surface exchange of particles can have a strong role in determining the amount, size, and chemical composition of particles in the troposphere. Here the authors consider only dry processes (deposition processes not directly aided by precipitation) and mostly address particles less than about 2 {micro}m in diameter (often referred to as submicron particles because most of such particles are less than 1 {micro}m in diameter). The processes that control the dry exchange of particulate material between the atmosphere and the surface of the Earth are numerous, highly varied, and sometimes poorly understood. As a result, determining which of the surface processes to parameterize or simulate in modeling the tropospheric mass budget of a particulate substance can be a significant challenge. Dry deposition, for example, can be controlled by a combination of Brownian diffusion, impaction, interception, and gravitational settling, depending on the size of the particles, the roughness of the surface on both micrometeorological and microscopic scales, the geometrical structure of vegetative canopies, and other surface characteristics such as wetness. Particles can be added to the lower atmosphere by resuspension from land surfaces and sea spray. The roles of rapid gas-to-particle conversion and growth or shrinkage of particles as a result of water condensation or evaporation in the lower few meters of the atmosphere can also have a significant impact on particle concentrations in the lower atmosphere. Here, a few micrometeorological observations and inferences on particle air-surface exchange are briefly addressed.

  1. Swimming Motility Reduces Deposition to Silica Surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Nanxi [Univ. of Illinois, Urbana-Champaign, IL (United States); Massoudieh, Arash [The Catholic Univ. of America, Washington, DC (United States); Liang, Xiaomeng [The Catholic Univ. of America, Washington, DC (United States); Hu, Dehong [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Kamai, Tamir [Agricultural Research Organization, Bet Dagan (Israel); Ginn, Timothy R. [Univ. of California, Davis, CA (United States); Zilles, Julie L. [Univ. of Illinois, Urbana-Champaign, IL (United States); Nguyen, Thanh H. [Univ. of Illinois, Urbana-Champaign, IL (United States)


    The role of swimming motility on bacterial transport and fate in porous media was evaluated. We present microscopic evidence showing that strong swimming motility reduces attachment of Azotobacter vinelandii cells to silica surfaces. Applying global and cluster statistical analyses to microscopic videos taken under non-flow conditions, wild type, flagellated A. vinelandii strain DJ showed strong swimming ability with an average speed of 13.1 μm/s, DJ77 showed impaired swimming averaged at 8.7 μm/s, and both the non-flagellated JZ52 and chemically treated DJ cells were non-motile. Quantitative analyses of trajectories observed at different distances above the collector of a radial stagnation point flow cell (RSPF) revealed that both swimming and non-swimming cells moved with the flow when at a distance of at least 20 μm from the collector surface. Near the surface, DJ cells showed both horizontal and vertical movement diverging them from reaching surfaces, while chemically treated DJ cells moved with the flow to reach surfaces, suggesting that strong swimming reduced attachment. In agreement with the RSPF results, the deposition rates obtained for two-dimensional multiple-collector micromodels were also lowest for DJ, while DJ77 and JZ52 showed similar values. Strong swimming specifically reduced deposition on the upstream surfaces of the micromodel collectors.

  2. Geology and fluorspar deposits, Northgate district, Colorado (United States)

    Steven, Thomas A.


    The fluorspar deposits in the Northgate district, Jackson County, Colo., are among the largest in Western United States. The mines were operated intermittently during the 1920's and again during World War II, but production during these early periods of operation was not large. Mining was begun on a larger scale in 1951, and the district has assumed a prominent position among the fluorspar producers in the United States. Within the Northgate district, Precambrian metamorphic and igneous rocks crop out largely in the Medicine Bow Mountains, and later sedimentary rocks underlie North Park and fill old stream valleys in the mountains. The metamorphic rocks constitute a gneiss complex that formed under progressively changing conditions of regional metamorphism. They consist principally of hornblende-plagioclase gneiss (hornblende gneiss), quartz monzonite gneiss, pegmatite, biotite-garnet-quartz-plagioclase gneiss (biotite-garnet gneiss), hornblende-biotite-quartz-plagioclase gneiss (hornblende-biotite gneiss) and mylonite gneiss. The igneous rocks comprise some local fine-grained dacite porphyry dikes near the west margin of the district, and a quartz monzonitic stock and associated dikes in the central and eastern parts of the district. The sedimentary rocks in the district range in age from Permian to Recent. Folded Permian and Mesozoic rocks underlie the basin of North Park, and consist in sequence from oldest to youngest, of Satanka(?) shale (0-50 feet of brick-red shale) and Forelle(?) limestone (8-15 feet of pink to light-gray laminated limestone) of Permian age, Chugwater formation of Permian and Triassic age (690 feet of red silty shale and sandstone), Sundance formation of Late Jurassic age (145 feet of sandstone containing some shale and limestone), Morrison formation of Late Jurassic age (445 feet of variegated shale and minor sandstone and limestone), Dakota group as used by Lee (1927), now considered to be of Early Cretaceous age in this area (200

  3. Modeling of the transport and deposition of polydispersed particles: Effects of hydrodynamics and spatiotemporal evolution of the deposition rate. (United States)

    Ma, Enze; Ouahbi, Tariq; Wang, Huaqing; Ahfir, Nasre-Dine; Alem, Abdellah; Hammadi, Ahmed


    A time-distance-dependent deposition model is built to investigate the effects of hydrodynamic forces on the transport and deposition of polydispersed particles and the evolution of deposition rates with time and distance. Straining and the heterogeneity of the particle population are considered to play important roles in the decreasing distribution of deposition rates. Numerical simulations were applied in a series of sand column experiments at different fluid velocities for three different porous media. The effects of hydrodynamics forces are elaborated with the systematic variations of deposition dynamic parameters of the proposed model. With retention distributions with particle size as well as temporal and spatial evolutions of deposition rates, the transport and deposition mechanisms of polydispersed particles will be elucidated through the interplay of the variation of the particle size distribution of mobile particle populations and the geometrical change of the porous medium due to retention (straining and blocking). Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Simulating ozone dry deposition at a boreal forest with a multi-layer canopy deposition model

    NARCIS (Netherlands)

    Zhou, Putian; Ganzeveld, Laurens; Rannik, Ullar; Zhou, Luxi; Gierens, Rosa; Taipale, Ditte; Mammarella, Ivan; Boy, Michael


    A multi-layer ozone (O3) dry deposition model has been implemented into SOSAA (a model to Simulate the concentrations of Organic vapours, Sulphuric Acid and Aerosols) to improve the representation of O3 concentration and flux within and above the forest canopy in the planetary boundary layer. We

  5. Numerical Modelling of Suspended Transport and Deposition of Highway Deposited Sediments

    DEFF Research Database (Denmark)

    Bentzen, Thomas Ruby; Larsen, Torben; Bach, Christine

    Good data for calibration and validation of numerical models are of high importance. In the natural environment data can be hard to archive and the stochastic nature have governing influence on the data archived. Hence for modelling of suspended transport and deposition of particles, originating...

  6. Silicon deposition in diatoms : Control by the pH inside the silicon deposition vesicle

    NARCIS (Netherlands)

    Vrieling, EG; Gieskes, WWC; Beelen, TPM

    To test the hypothesis that silicification occurs under acid conditions in the silicon deposition vesicle (SDV), the acidity of the SDV of the pennate diatoms Navicula pelliculosa (Brebisson et Kutzing) Hilse, N. salinarum (Grunow) Hustedt, and Nitzschia sigma (Kutzing) Smith was determined during

  7. Aspects of thin film deposition on granulates by physical vapor deposition (United States)

    Eder, Andreas; Schmid, Gerwin H. S.; Mahr, Harald; Eisenmenger-Sittner, Christoph


    Thin film and coating technology has entered fields which may show significant deviations from classical coating applications where films are deposited on plane, sometimes large substrates. Often surfaces of small and irregularly shaped bodies have to be improved in respect to electrical, thermal or mechanical properties. Film deposition and characterization on such small substrates is not a trivial task. This specially holds for methods based on Physical Vapor Deposition (PVD) processes such as sputter deposition and its ion- and plasma assisted varieties. Due to their line of sight nature a key issue for homogenous films is efficient intermixing. If this problem is mastered, another task is the prediction and determination of the film thickness on single particles as well as on large scale ensembles thereof. In this work a mechanism capable of uniformly coating up to 1000 cm3 of granulate with particle sizes ranging from approx. 10 μm to 150 μm by magnetron sputtering is thoroughly described. A method for predicting the average film thickness on the particles is presented and tested for several differently shaped objects like microspheres, irregular grains of sinter powder or micro diamonds. For assessing the film thickness on single particles as well as on particle ensembles several complementary methods based on optics, X-ray analysis and gravimetry are employed. Their respective merits and limitations are discussed. Finally an outlook on adapting the described technology for surface modification by plasma based reactive and non-reactive processes is given.

  8. Characteristics of high quality ZnO thin films deposited by pulsed laser deposition

    NARCIS (Netherlands)

    Craciun, V.; Elders, J.; Gardeniers, Johannes G.E.; Boyd, Ian W.


    This paper show that under optimized deposition condition, films can be grown having a full width at half maximum (FWHM) value of the (002) x-ray diffraction (XRD) line a factor of 4 smaller than the previously published results using PLD and among the best reported so far by any technique. Under

  9. Ultraviolet optical properties of aluminum fluoride thin films deposited by atomic layer deposition

    Energy Technology Data Exchange (ETDEWEB)

    Hennessy, John, E-mail:; Jewell, April D.; Balasubramanian, Kunjithapatham; Nikzad, Shouleh [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, California 91109 (United States)


    Aluminum fluoride (AlF{sub 3}) is a low refractive index material with promising optical applications for ultraviolet (UV) wavelengths. An atomic layer deposition process using trimethylaluminum and anhydrous hydrogen fluoride has been developed for the deposition of AlF{sub 3} at substrate temperatures between 100 and 200 °C. This low temperature process has resulted in thin films with UV-optical properties that have been characterized by ellipsometric and reflection/transmission measurements at wavelengths down to 200 nm. The optical loss for 93 nm thick films deposited at 100 °C was measured to be less than 0.2% from visible wavelengths down to 200 nm, and additional microstructural characterization demonstrates that the films are amorphous with moderate tensile stress of 42–105 MPa as deposited on silicon substrates. X-ray photoelectron spectroscopy analysis shows no signature of residual aluminum oxide components making these films good candidates for a variety of applications at even shorter UV wavelengths.

  10. 76 FR 7740 - Amendments to Deposit Insurance Regulations: Deposit Insurance Coverage Training; SMDIA Notification (United States)


    ... Internet or other technology. Third, the rule would require IDIs to provide a link to the FDIC's Electronic... Internet or by means of other technology, these inquiries can be included in the paper or electronic... deposit accounts opened by mail or via the Internet or other technology, the publication can be provided...

  11. Breakthrough to Non-Vacuum Deposition of Single-Crystal, Ultra-Thin, Homogeneous Nanoparticle Layers: A Better Alternative to Chemical Bath Deposition and Atomic Layer Deposition

    Directory of Open Access Journals (Sweden)

    Yu-Kuang Liao


    Full Text Available Most thin-film techniques require a multiple vacuum process, and cannot produce high-coverage continuous thin films with the thickness of a few nanometers on rough surfaces. We present a new ”paradigm shift” non-vacuum process to deposit high-quality, ultra-thin, single-crystal layers of coalesced sulfide nanoparticles (NPs with controllable thickness down to a few nanometers, based on thermal decomposition. This provides high-coverage, homogeneous thickness, and large-area deposition over a rough surface, with little material loss or liquid chemical waste, and deposition rates of 10 nm/min. This technique can potentially replace conventional thin-film deposition methods, such as atomic layer deposition (ALD and chemical bath deposition (CBD as used by the Cu(In,GaSe2 (CIGS thin-film solar cell industry for decades. We demonstrate 32% improvement of CIGS thin-film solar cell efficiency in comparison to reference devices prepared by conventional CBD deposition method by depositing the ZnS NPs buffer layer using the new process. The new ZnS NPs layer allows reduction of an intrinsic ZnO layer, which can lead to severe shunt leakage in case of a CBD buffer layer. This leads to a 65% relative efficiency increase.

  12. Breakthrough to Non-Vacuum Deposition of Single-Crystal, Ultra-Thin, Homogeneous Nanoparticle Layers: A Better Alternative to Chemical Bath Deposition and Atomic Layer Deposition. (United States)

    Liao, Yu-Kuang; Liu, Yung-Tsung; Hsieh, Dan-Hua; Shen, Tien-Lin; Hsieh, Ming-Yang; Tzou, An-Jye; Chen, Shih-Chen; Tsai, Yu-Lin; Lin, Wei-Sheng; Chan, Sheng-Wen; Shen, Yen-Ping; Cheng, Shun-Jen; Chen, Chyong-Hua; Wu, Kaung-Hsiung; Chen, Hao-Ming; Kuo, Shou-Yi; Charlton, Martin D B; Hsieh, Tung-Po; Kuo, Hao-Chung


    Most thin-film techniques require a multiple vacuum process, and cannot produce high-coverage continuous thin films with the thickness of a few nanometers on rough surfaces. We present a new "paradigm shift" non-vacuum process to deposit high-quality, ultra-thin, single-crystal layers of coalesced sulfide nanoparticles (NPs) with controllable thickness down to a few nanometers, based on thermal decomposition. This provides high-coverage, homogeneous thickness, and large-area deposition over a rough surface, with little material loss or liquid chemical waste, and deposition rates of 10 nm/min. This technique can potentially replace conventional thin-film deposition methods, such as atomic layer deposition (ALD) and chemical bath deposition (CBD) as used by the Cu(In,Ga)Se₂ (CIGS) thin-film solar cell industry for decades. We demonstrate 32% improvement of CIGS thin-film solar cell efficiency in comparison to reference devices prepared by conventional CBD deposition method by depositing the ZnS NPs buffer layer using the new process. The new ZnS NPs layer allows reduction of an intrinsic ZnO layer, which can lead to severe shunt leakage in case of a CBD buffer layer. This leads to a 65% relative efficiency increase.


    Directory of Open Access Journals (Sweden)

    Nadezhda Bova


    Full Text Available The purpose of the paper is to define and demonstrate the role of deposit policy for banking institutions, summarize and highlight the problems and its solutions in deposit policy of Ukraine that provides economic downturn and recovery. Appropriate selection and implementation of the deposit policy objectives, its operational structure and tools determines the degree of development of financial inclusion, which generate developed financial market, ensures public confidence to the deposit services, and increases the level of savings that positively affects the banking system financial stability and economy in the country in whole. It is because of availability and security deposit services, commercial banks of Ukraine have the opportunity to increase its resource base due to savings of the population. Methodology. The paper is based on a synthesis of data to explore the bank deposit policy situation. The paper considers the scientific and theoretical approaches for the developing the deposit policy management. It contains the analysis of the dynamics and current situation and conditions of the resource potential of banking institutions in Ukraine. Results of the article shows direct dependency between savings, consumption and deposit policy, therefore every banking institution includes the mechanism of banking management of the development and implementation of deposit policy. Also, this management defines the deposit policy directions according to the conditions of bank resources mobilization and its applying in active operations. The obtained results confirm that the term “deposit policy” is too complex, but it is investigated in interaction with banking activity. It is explained how deposit policy influences banking system and has impact on economic growth in general. Practical implications. The research creates methodological approaches to the measurement of effectiveness of deposit policy. Also, it studies the existing ones. It provides

  14. 25 years of pulsed laser deposition (United States)

    Lorenz, Michael; Ramachandra Rao, M. S.


    It is our pleasure to introduce this special issue appearing on the occasion of the 25th anniversary of pulsed laser deposition (PLD), which is today one of the most versatile growth techniques for oxide thin films and nanostructures. Ever since its invention, PLD has revolutionized the research on advanced functional oxides due to its ability to yield high-quality thin films, multilayers and heterostructures of a variety of multi-element material systems with rather simple technical means. We appreciate that the use of lasers to deposit films via ablation (now termed PLD) has been known since the 1960s after the invention of the first ruby laser. However, in the first two decades, PLD was something of a 'sleeping beauty' with only a few publications per year, as shown below. This state of hibernation ended abruptly with the advent of high T c superconductor research when scientists needed to grow high-quality thin films of multi-component high T c oxide systems. When most of the conventional growth techniques failed, the invention of PLD by T (Venky) Venkatesan clearly demonstrated that the newly discovered high-T c superconductor, YBa2Cu3O7-δ , could be stoichiometrically deposited as a high-quality nm-thin film with PLD [1]. As a remarkable highlight of this special issue, Venkatesan gives us his very personal reminiscence on these particularly innovative years of PLD beginning in 1986 [2]. After Venky's first paper [1], the importance of this invention was realized worldwide and the number of publications on PLD increased exponentially, as shown in figure 1. Figure 1. Figure 1. Published items per year with title or topic PLD. Data from Thomson Reuters Web of Knowledge in September 2013. After publication of Venky's famous paper in 1987 [1], the story of PLD's success began with a sudden jump in the number of publications, about 25 years ago. A first PLD textbook covering its basic understanding was soon published, in 1994, by Chrisey and Hubler [3]. Within a

  15. Storm wave deposits in southern Istria (Croatia) (United States)

    Biolchi, Sara; Furlani, Stefano; Devoto, Stefano; Scicchitano, Giovanni


    The accumulation of large boulders related to extreme waves are well documented in different areas of the Mediterranean coasts, such as in Turkey, Algeria, Egypt, Greece (Lesbos and Crete islands), France, Spain, Malta, Italy (Sicily and Apulia regions). These deposits have been associated to storm or tsunami events or both, depending on the local history. If compared to the Mediterranean Sea, the Adriatic Sea is considered a shallow basin, with very low wave energy. In particular the NE Adriatic, where Istria Peninsula (Croatia) is located, geological and geomorphological evidences of extreme wave events have never been described, as well as no tsunamis have been registered. We present the boulder deposits that have been recently found out in southern Istria, at Premantura and Marlera localities and we discuss the mechanisms that could have been responsible of the detachment and movement of these large rocky blocks from the emerged part of the coast and from the sea bottom inland. A multidisciplinary approach was adopted: geological and geomorphological surveyings, UAV and digital photogrammetric analysis, applying of the hydrodynamic equations as well as underwater profiles were carried out between 2012 and 2016. The southern Istrian coasts are composed of Cretaceous bedded limestones, sub-horizontal or gently inclined toward the sea and are exposed to southern winds, Scirocco and Libeccio, with wide fetch. The boulder deposits occur in correspondence of flat promontories or ancient quarry pavements, where the topography, together with the bedding planes and a dense fracture pattern constitute the predisposing factors of the boulder sizing and detachment. Boulder sizes, density, position and elevation have been measured in order to apply the hydrodynamic equations, which provide wave height values that can discriminate a storm from a tsunami origin. Biogenic marine encrustations, sometimes very recent, have been observed on large part of the boulders, attesting

  16. Heterogeneity of the composition of the lithosphere and consanguinity of mineral deposits in eastern China (United States)

    Tingyu, Chen

    The distribution of mineral deposits in eastern China is heterogeneous. Principally, Au deposits are concentrated in northeast China, Fe deposits in northern China, Cu deposits in the Lower Yangzi River Valley, W deposits in the Nanling and surrounding regions, and Sn deposits in the area of Guangdong and Guangxi. This heterogeneity might reflect the nature of the primordial lithosphere of our planet.

  17. Deposition and benthic mineralization of organic carbon

    DEFF Research Database (Denmark)

    á Nordi, Gunnvør; Glud, Ronnie N.; Simonsen, Knud


    Seasonal variations in sedimentation and benthic mineralization of organic carbon (OC) were investigated in a Faroese fjord. Deposited particulate organic carbon (POC) was mainly of marine origin, with terrestrial material only accounting for b1%. On an annual basis the POC export fromthe euphotic...... of the fjord. Thiswas supported by the fact that themeasured benthic mineralization rate – in contrast to most investigations – actually increased with increasing water depth. In August,whenmineralization was at its maximum, the dissolved inorganic carbon (DIC) release from the sediment increased by 2.2mmolm−2...... for the water depth related changes in activity. The study in Kaldbaksfjørður underscore that fjords are important sites for long time OC burial, but emphasize the need for accounting for spatial variations when extrapolating results from a single or few stations to the scale of the entire fjord....

  18. Zebra rocks: compaction waves create ore deposits. (United States)

    Kelka, Ulrich; Veveakis, Manolis; Koehn, Daniel; Beaudoin, Nicolas


    Nature has a range of distinct mechanisms that cause initially heterogeneous systems to break their symmetry and form patterns. One of these patterns is zebra dolomite that is frequently hosting economically important base metal mineralization. A consistent generic model for the genesis of these periodically banded rocks is still lacking. In this contribution, we present for the first time a fully consistent mathematical model for the genesis of the pattern by coupling the reactive fluid-solid system with hydromechanics. We show that visual banding develops at a given stress and host-rock permeability indicating that the wavelength and occurrence of the pattern may be predictable for natural settings. This finding offers the exciting possibility of estimating conditions of formation of known deposits as well as forecasting potential exploration targets.

  19. Towards Commercial Gas Production from Hydrate Deposits

    Directory of Open Access Journals (Sweden)

    Richard Dawe


    Full Text Available Over the last decade global natural gas consumption has steadily increased since many industrialized countries are substituting natural gas for coal to generate electricity. There is also significant industrialization and economic growth of the heavily populated Asian countries of India and China. The general consensus is that there are vast quantities of natural gas trapped in hydrate deposits in geological systems, and this has resulted in the emerging importance of hydrates as a potential energy resource and an accompanying proliferation of recent studies on the technical and economic feasibility of gas production from hydrates. There are then the associated environmental concerns. This study reviews the state of knowledge with respect to natural gas hydrates and outlines remaining challenges and knowledge gaps.

  20. Effect of argon during diamond deposition

    Energy Technology Data Exchange (ETDEWEB)

    Barbosa, D.C.; Mengui, U.A.; Contin, A.; Trava-Airoldi, V.J.; Baldan, M.R.; Corat, E.J. [Instituto Nacional de Pesquisas Espaciais (INPE), Sao Jose dos Campos, SP (Brazil). Laboratorio Associado de Sensores e Materiais


    The effect of argon content upon the growth rate and the properties of diamond thin films grown with different grains sizes is explored. An argon-free and argon-rich gas mixture of methane and hydrogen is used in a hot filament chemical vapor deposition reactor. Characterization of the films is accomplished by scanning electron microscopy, Raman spectroscopy and high-resolution x-ray diffraction. An extensive comparison of the growth rate values obtained in this study with those found in the literature suggests that there are distinct common trends for microcrystalline and nanocrystalline diamond growth, despite a large variation in the gas mixture composition. Included is a discussion of the possible reasons for these observations. (author)


    Directory of Open Access Journals (Sweden)

    S A Vladimirov


    Full Text Available Objective: to study the incidence of osteoporosis (OP in patients with calcium pyrophosphate crystal deposition disease (CPCDD. Subjects and methods. Eighty patients with CPCDD were examined. Bone mineral density (BMD of the forearm, lumbar spine, and femoral neck was determined by dual-energy X-ray absorptiometry. Laboratory diagnosis involved determination of the blood levels of C-reactive protein, parathyroid hormone, calcium, magnesium, and phosphorus and the daily urinary excretion of calcium and phosphates. Results. The patients with OP were significantly older than those with normal BMD and osteopenia. Forearm bones were the most common isolated location of OP and osteopenia. Injuries in the history, traumatic fractures, and the intake of diuretics were somewhat more common in the patients diagnosed with OP. The incidence of hyperparathyroidism did not differ significantly in the groups.

  2. Understanding error generation in fused deposition modeling (United States)

    Bochmann, Lennart; Bayley, Cindy; Helu, Moneer; Transchel, Robert; Wegener, Konrad; Dornfeld, David


    Additive manufacturing offers completely new possibilities for the manufacturing of parts. The advantages of flexibility and convenience of additive manufacturing have had a significant impact on many industries, and optimizing part quality is crucial for expanding its utilization. This research aims to determine the sources of imprecision in fused deposition modeling (FDM). Process errors in terms of surface quality, accuracy and precision are identified and quantified, and an error-budget approach is used to characterize errors of the machine tool. It was determined that accuracy and precision in the y direction (0.08-0.30 mm) are generally greater than in the x direction (0.12-0.62 mm) and the z direction (0.21-0.57 mm). Furthermore, accuracy and precision tend to decrease at increasing axis positions. The results of this work can be used to identify possible process improvements in the design and control of FDM technology.

  3. Transport and deposition of thickened uranium tailings

    Energy Technology Data Exchange (ETDEWEB)

    Paulsen, E., E-mail: [AREVA Resources Canada, Inc., Saskatoon, SK (Canada)


    The McClean Lake operation has experienced several problems relating to the thickened tailings disposal system. These include issues relating to segregation, inadequate pumping capacity, and unstable pipeline operation. Segregation in the tailings management facility is of particular importance since it negatively impacts the long-term containment of arsenic and the consolidation of the tails solids. These issues have direct implications on the regulatory requirements of the operation. As a result several initiatives relating to tailings thickening, transport, and deposition were proposed and implemented. This paper presents an audit of the existing tailings transport system based on the rheological requirements of homogeneous tailings as well as the proposed changes and preliminary results of this study. (author)

  4. Occurrence model for volcanogenic beryllium deposits: Chapter F in Mineral deposit models for resource assessment (United States)

    Foley, Nora K.; Hofstra, Albert H.; Lindsey, David A.; Seal, Robert R.; Jaskula, Brian W.; Piatak, Nadine M.


    Current global and domestic mineral resources of beryllium (Be) for industrial uses are dominated by ores produced from deposits of the volcanogenic Be type. Beryllium deposits of this type can form where hydrothermal fluids interact with fluorine and lithophile-element (uranium, thorium, rubidium, lithium, beryllium, cesium, tantalum, rare earth elements, and tin) enriched volcanic rocks that contain a highly reactive lithic component, such as carbonate clasts. Volcanic and hypabyssal high-silica biotite-bearing topaz rhyolite constitutes the most well-recognized igneous suite associated with such Be deposits. The exemplar setting is an extensional tectonic environment, such as that characterized by the Basin and Range Province, where younger topaz-bearing igneous rock sequences overlie older dolomite, quartzite, shale, and limestone sequences. Mined deposits and related mineralized rocks at Spor Mountain, Utah, make up a unique economic deposit of volcanogenic Be having extensive production and proven and probable reserves. Proven reserves in Utah, as reported by the U.S. Geological Survey National Mineral Information Center, total about 15,900 tons of Be that are present in the mineral bertrandite (Be4Si2O7(OH)2). At the type locality for volcanogenic Be, Spor Mountain, the tuffaceous breccias and stratified tuffs that host the Be ore formed as a result of explosive volcanism that brought carbonate and other lithic fragments to the surface through vent structures that cut the underlying dolomitic Paleozoic sedimentary rock sequences. The tuffaceous sediments and lithic clasts are thought to make up phreatomagmatic base surge deposits. Hydrothermal fluids leached Be from volcanic glass in the tuff and redeposited the Be as bertrandite upon reaction of the hydrothermal fluid with carbonate clasts in lithic-rich sections of tuff. The localization of the deposits in tuff above fluorite-mineralized faults in carbonate rocks, together with isotopic evidence for the

  5. Chemical mediation of egg capsule deposition by mud snails. (United States)

    Rittschof, Dan; Sawardecker, Prasad; Petry, Caroline


    Mud snails (Ilyanassa obsoleta = Nassarius obsoletus = Nassa obsoleta) deposit eggs in protective capsules on hard substrata in soft bottom environments. We studied sites of egg capsule deposition and snail movement responses to odors to determine if chemoreception plays a role in deposition site selection. From results of field surveys, laboratory experiments, and field experiments, we conclude that mud snails use chemoreception for capsule deposition. Attractive odors originate from mud snail and whelk egg capsules and from living bivalves. Evidence for attractive odors from conspecifics is equivocal. Capsules are deposited on living odor sources and nearby hard substrates. We hypothesize that deposition of capsules on living substrates increases the likelihood that embryos will survive by decreasing the chance of smothering of embryos by sediments.

  6. Experimental study of aerosol deposition in pulsating balloon structures. (United States)

    Yue, G; Fadl, A; Barek, T; Zhang, Z; Major, J


    In this study, aerosol depositions within pulsating balloon structures are investigated. Cyclical motion of expansion and contraction of the balloon models are controlled by varying the surrounding vacuum pressures inside the air chamber. Balloons of various configurations are used to induce the air flows as well as to collect the deposited particles. The non-uniform distribution patterns of particle deposition inside the models are measured by fluorescence spectrophotometer. Different airflow rates are investigated. The objective of this study is to qualitatively investigate the phenomena of enhanced particle local deposition in pockets with moving wall conditions. It has been observed in the experiments that a particle deposition "hot spot" exists at the entrance of balloon model for almost all flow rates covered in the study and the moving boundary flow enhances the aerosol deposition significantly.

  7. Mesoscale Particle-Based Model of Electrophoretic Deposition

    Energy Technology Data Exchange (ETDEWEB)

    Giera, Brian; Zepeda-Ruiz, Luis A.; Pascall, Andrew J.; Weisgraber, Todd H.


    We present and evaluate a semiempirical particle-based model of electrophoretic deposition using extensive mesoscale simulations. We analyze particle configurations in order to observe how colloids accumulate at the electrode and arrange into deposits. In agreement with existing continuum models, the thickness of the deposit increases linearly in time during deposition. Resulting colloidal deposits exhibit a transition between highly ordered and bulk disordered regions that can give rise to an appreciable density gradient under certain simulated conditions. The overall volume fraction increases and falls within a narrow range as the driving force due to the electric field increases and repulsive intercolloidal interactions decrease. We postulate ordering and stacking within the initial layer(s) dramatically impacts the microstructure of the deposits. We find a combination of parameters, i.e., electric field and suspension properties, whose interplay enhances colloidal ordering beyond the commonly known approach of only reducing the driving force.

  8. High power RF window deposition apparatus, method, and device (United States)

    Ives, Lawrence R.; Lucovsky, Gerald; Zeller, Daniel


    A process for forming a coating for an RF window which has improved secondary electron emission and reduced multipactor for high power RF waveguides is formed from a substrate with low loss tangent and desirable mechanical characteristics. The substrate has an RPAO deposition layer applied which oxygenates the surface of the substrate to remove carbon impurities, thereafter has an RPAN deposition layer applied to nitrogen activate the surface of the substrate, after which a TiN deposition layer is applied using Titanium tert-butoxide. The TiN deposition layer is capped with a final RPAN deposition layer of nitridation to reduce the bound oxygen in the TiN deposition layer. The resulting RF window has greatly improved titanium layer adhesion, reduced multipactor, and is able to withstand greater RF power levels than provided by the prior art.

  9. Behaviors and mechanism of electrolyte electrophoresis during electrophoretic deposition

    Energy Technology Data Exchange (ETDEWEB)

    Ciou, Sian-Jie; Fung, Kuan-Zong [Department of Materials Science and Engineering, National Cheng Kung University, Tainan 70101 (China); Chiang, Kai-Wei [Department of Geomatics, National Cheng Kung University, Tainan 70101 (China)


    Electrochemical experiments, including cyclic voltammetry (CV) experiments, galvanostatic experiments, potentiostatic experiments, and kinetic experiments of the LSM electrode, were used to investigate the influence of a deposit on the electrode surface on the electrophoresis of protons in a porous media during electrophoretic deposition (EPD). In the kinetic experiments, the deposit reduced the electrochemical reaction rate of the LSM electrode according to the Tafel plots for the cathode where the YSZ was deposited. It was also observed that hydrogen was reduced at the cathode from the cyclic voltammogram. In the galvanostatic experiments, the proton concentration increased near the cathode because the deposit obstructed the electrode reaction. In the potentiostatic experiments, similar phenomena were observed. The deposit from the EPD became an obstacle to the electrochemical reaction, resulting in unusual kinetic behaviors of proton electrophoresis during electrolysis. (author)

  10. Fate of Deposited Nitrogen in Tropical Forests in Southern China

    DEFF Research Database (Denmark)

    Gurmesa, Geshere Abdisa

    and denitrification from the ecosystem. Loss of N, in turn, has many negative consequences, including soil and surface water acidification, plant nutrient imbalances and related adverse effects on biological diversities. Increased atmospheric N deposition that is anticipated for tropical regions may further aggravate...... these negative consequences. Thus, an improved understanding of how increased atmospheric N deposition impacts N retention efficiency of tropical forests is needed. However, the fate of deposited N in tropical forest ecosystems and its retention mechanisms remains elusive. This PhD thesis used the stable...... nitrogen (N) isotope 15N to uncover two aspects of N cycling in tropical forests: i) the patterns of ecosystem natural 15N abundance (δ15N) in relation to the 15N signature of deposition N, and its response to increased N deposition; ii) the fate of ambient and increased N deposition in the same forests...

  11. Surface Morphology of Zinc Oxide Thin Films deposited by TCVD (United States)

    Rafaie, H. A.; Noor, F. W. M.; Amizam, S.; Abdullah, S.; Rusop, M.


    Surface morphology study of Zinc Oxide (ZnO) thin films by using Thermal Chemical Vapor Deposition (Thermal-CVD) was investigated. The ZnO compound was synthesized from zinc acetate dehydrate which act as a starting material to form the ZnO thin films. It was deposited on as-prepared Nanonstructured Silicon (NSi) with deposition temperature ranging from 400-600° C without catalyst-assisted. The surface morphology of the samples before and after the deposition process was examined by using Analytical Scanning Electron Microscope (SEM). The result shows that the obtained ZnO thin films possess good crystalline structure at deposition temperature of 600° C and the surface morphologies of the ZnO thin films improved greatly with an increase in deposition temperature. XRD was employed to study the evolution of the crystalline orientation using X-Ray Diffractrometer (XRD).

  12. Effects of acid deposition on tree roots

    Energy Technology Data Exchange (ETDEWEB)

    Persson, H. [Swedish Univ. of Agricultural Sciences (Sweden). Dept. of Ecology and Environmental Research


    Large forest regions in SW Sweden have been exposed to high levels of acid deposition for many decades, causing soil acidification in forest soils. Historically, SO{sub 2} has been the major acidification agent, but lately nitrogen compounds increasingly have become important. The amount and chemical form of nitrogen strongly affects the pH in the rhizosphere and rhizoplane. Many forest stands show a positive growth response to increased nitrogen input, even in heavily N-loaded areas. Nitrogen fertilization experiments suggest that part of the increased forest production is caused by a translocation of biomass production from below-ground to above-ground parts. At the same time fine-root growth dynamics are strongly affected by the high N supply. Deficiencies of various nutrients (Mg,Ca,K,Mn and Zn) obtained from needle analyses have been reported from different Picea abies stands. In areas with more extensive acidification and nutrient leaching, a decline in tree vitality has been observed. Although deficiency symptoms in forest trees may be reflected in nitrogen/cation ratios in fine roots, few attempts have been made to explain forest damage symptoms from fine-root chemistry. Root damage is often described as a decline in the amount of living fine roots, an increase in the amount of dead versus live fine roots (a lower live/dead ratio) and an increasing amount of dead medium and coarse roots. The primary objectives of the present presentation were to analyse available data on the effects of high nitrogen and sulphur deposition on mineral nutrient balance in tree fine roots and to evaluate the risk of Al interference with cation uptake by roots

  13. Calcium pyrophosphate deposition disease: clinical manifestations

    Directory of Open Access Journals (Sweden)

    M.A. Cimmino


    Full Text Available Calcium pyrophosphate deposition (CPPD disease is an arthropathy caused by calcium pyrophosphate dihydrate (CPP crystal deposits in articular tissues, most commonly fibrocartilage and hyaline cartilage. According to EULAR, four different clinical presentations can be observed: 1 asymptomatic CPPD; 2 osteoarthritis (OA with CPPD; 3 acute CPP crystal arthritis; 4 chronic CPP inflammatory crystal arthritis. Acute CPP crystal arthritis is characterized by sudden onset of pain, swelling and tenderness with overlying erythema, usually in a large joint, most often the knee, wrist, shoulder, and hip. Occasionally, ligaments, tendons, bursae, bone and the spine can be involved. CPPD of the atlanto-occipital joint (crowned dens syndrome can cause periodic acute cervico-occipital pain with fever, neck stiffness and laboratory inflammatory syndrome. Chronic inflammatory arthritis is characterized by joint swelling, morning stiffness, pain, and high ESR and CRP. The relationship between OA and CPPD is still unclear. The main problem is whether such crystals are directly involved in the pathogenesis of OA or if they are the result of joint degeneration. Diagnosis is based on evaluation of history and clinical features, conventional radiology, and synovial fluid examination. Non-polarized light microscopy should be used initially to screen for CPPD crystals based upon their characteristic morphology, and compensated polarized light microscopy, showing the crystals to be weakly positive birefringent, is recommended for definitive identification, although this last pattern only occurs in about 20% of samples. The main goals of CPPD therapy are control of the acute or chronic inflammatory reaction and prevention of further episodes.

  14. Occupational monitoring at radioactive waste deposit

    Energy Technology Data Exchange (ETDEWEB)

    Pereira, Wagner S.; Cunha, Franklin S. [Indústrias Nucleares do Brasil (COMAP.N/FCN/INB), Resende, RJ (Brazil). Fábrica de Combustível Nuclear. Coordenação de Meio Ambiente e Proteção Radiológica Ambiental; Kelecom, Alphonse [Universidade Federal Fluminense (LARARA-PLS/UFF), Niterói, RJ (Brazil). Lab. de Radiobiologia e Radiometria Pedro Lopes dos Santos; Silva, Ademir X., E-mail:, E-mail:, E-mail:, E-mail:, E-mail: [Coordenacao de Pos-Graduacao e Pesquisa de Engenharia (PEN/COPPE/UFRJ), Rio de Janeiro, RJ (Brazil). Programa de Engenharia Nuclear


    The Initial Deposit of Low Activity Radioactive Waste - DIRBA is an ancillary facility to the Nuclear Fuel Factory - FCN for the initial storage of low activity radioactive waste generated in the nuclear fuel cycle under the responsibility of the FCN. Currently approximately 460 200-liter drums containing Class 2.3 waste are stored: Waste containing Natural Radionuclides (RBMN-RN). As part of the nuclear licensing of the facility, an area radiological monitoring program was developed with monthly monitoring of 17 exposure points, 3 direct long-distance air sampling points with CAM alpha-7 monitors, monitored in January and 9 points where smears of alpha long half-life emitters were monitored in January. The mean exposure rate between points was 0.5 μSv∙h{sup -1}, with a maximum of 1.27 μSv∙h{sup -1} varying, on average, between 0.98 μSv∙h{sup -1} at point P1 to 0.23 μSv∙h{sup -1} at P11. The monthly average was the same, 0.50 μSv∙h-1, ranging from 0.46 μSv∙h{sup -1} (November) to 0.57 μSv∙h{sup -1} (August). The half-life long-lived alpha sampling were all below the MDA as well as the 9 smears. Regarding the requirements of monitored areas, the deposit must be considered as supervised area, from the point of view of radioprotection. The possibility of tipping the drums or other accidents with spillage of material contained into them caused, in a proactive way, the area to be considered a controlled area. (author)

  15. The physical hydrogeology of ore deposits (United States)

    Ingebritsen, Steven E.; Appold, M.S.


    Hydrothermal ore deposits represent a convergence of fluid flow, thermal energy, and solute flux that is hydrogeologically unusual. From the hydrogeologic perspective, hydrothermal ore deposition represents a complex coupled-flow problem—sufficiently complex that physically rigorous description of the coupled thermal (T), hydraulic (H), mechanical (M), and chemical (C) processes (THMC modeling) continues to challenge our computational ability. Though research into these coupled behaviors has found only a limited subset to be quantitatively tractable, it has yielded valuable insights into the workings of hydrothermal systems in a wide range of geologic environments including sedimentary, metamorphic, and magmatic. Examples of these insights include the quantification of likely driving mechanisms, rates and paths of fluid flow, ore-mineral precipitation mechanisms, longevity of hydrothermal systems, mechanisms by which hydrothermal fluids acquire their temperature and composition, and the controlling influence of permeability and other rock properties on hydrothermal fluid behavior. In this communication we review some of the fundamental theory needed to characterize the physical hydrogeology of hydrothermal systems and discuss how this theory has been applied in studies of Mississippi Valley-type, tabular uranium, porphyry, epithermal, and mid-ocean ridge ore-forming systems. A key limitation in the computational state-of-the-art is the inability to describe fluid flow and transport fully in the many ore systems that show evidence of repeated shear or tensional failure with associated dynamic variations in permeability. However, we discuss global-scale compilations that suggest some numerical constraints on both mean and dynamically enhanced crustal permeability. Principles of physical hydrogeology can be powerful tools for investigating hydrothermal ore formation and are becoming increasingly accessible with ongoing advances in modeling software.

  16. Vein graphite deposits: geological settings, origin, and economic significance


    Luque del Villar, Francisco Javier; Huizenga, Jan-Marten; Crespo Feo, Elena; Wada, Hideki; Ortega Menor, Lorena; Barrenechea, Edurne


    Graphite deposits result from the metamorphism of sedimentary rocks rich in carbonaceous matter or from precipitation from carbon-bearing fluids (or melts). The latter process forms vein deposits which are structurally controlled and usually occur in granulites or igneous rocks. The origin of carbon, the mechanisms of transport, and the factors controlling graphite deposition are discussed in relation to their geological settings. Carbon in granulite-hosted graphite veins derives from sublith...

  17. 26 CFR 3.2 - Ceiling on deposits. (United States)


    ... 26 Internal Revenue 14 2010-04-01 2010-04-01 false Ceiling on deposits. 3.2 Section 3.2 Internal... CONSTRUCTION FUND § 3.2 Ceiling on deposits. (a) In general—(1) Total ceiling. Section 607(b) of the Act provides a ceiling on the amount which may be deposited by a party for a taxable year pursuant to an...

  18. The technology of Plasma Spray Physical Vapour Deposition


    M. Góral; J. Sieniawski


    Purpose: The deposition of thermal barrier coatings is currently the most effective means of protecting the surface of aircraft engine turbine blades from the impact of aggressive environment of combustion gases. The new technologies of TBC depositions are required.Design/methodology/approach: The essential properties of the PS-PVD process have been outlined, as well as recent literature references. In addition, the influence of a set process condition on the properties of the deposited coati...

  19. Reducing Abdominal Fat Deposition in Broiler Through Feeding Management


    Cecep Hidayat


    Abdominal fat in broiler carcass is considered as a waste and its existence reduces the carcass quality. Abdominal fat deposition is affected by several factors such as genetic, nutrition, feed, sex, age and environment. Reducing abdominal fat deposition can be carried out by regulating the nutrient intake to ensure that no excessive nutrient was consumed. Nutrition effects to reduce abdominal fat deposition are associated with nutrient concentration of ration and quantity of daily feed intak...

  20. Programming system for rapid evaluation of coal deposits


    Stanìk Frantiek


    Programming system for rapid evaluation of coal deposits (calculation of coal reserves) based on data stored in coal deposit database including processing of textual and graphic outputs was elaborated. The nature of such outputs is based on conventional coal reserve calculations so that connection with coal reserve calculations made in the past is secured. Differences in particular coal deposits as well as in individual coal seams are respected in the system. Coal seams differ one from anothe...