Sample records for tailings impoundment solutions

  1. Design, permitting, and construction issues associated with closure of the Panna Maria uranium tailings impoundment

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Strachan, C.L.; Raabe, K.L.

    1997-12-31

    In 1992, Panna Maria Uranium Operations (PMUO) initiated licensing and engineering activities for closure of the Panna Maria mill and 150-acre tailings impoundment located in southeast Texas. Closure of the tailings impoundment is permitted by license amendment through the Texas Natural Resources Conservation Commission (TNRCC), and based on closure criteria outlined in Texas regulations. The closure plan for the Panna Maria tailings impoundment was submitted for Texas regulatory agency review in April 1993, with details of the closure plan modified in 1994, 1995, and 1996. The closure plan included a multi-layered cover over the regraded tailings surface which was designedmore » for long-term isolation of tailings, reduction of radon emanation to regulated levels, and reduction of infiltration to TNRCC-accepted levels. The cover and embankment slope surfaces and surrounding areas were designed to provide acceptable erosional stability as compared to runoff velocities from the Probable Maximum Precipitation event. Cover materials were selected from on-site materials and evaluated for suitability based on permeability, radon attenuation, and soil dispersivity characteristics. Off-site materials were used when necessary. The cover over the tailings has a maximum slope of 0.5 percent, and the regraded embankment slopes outside the perimeter of the impoundment have a maximum slope of 20 percent. All reclaimed slopes are covered with topsoil and revegetated. A riprap-lined channel is to be used to convey runoff from within the perimeter of the reclaimed impoundment to the north of the impoundment.« less

  2. Development of a dust deposition forecast model for a mine tailings impoundment

    NASA Astrophysics Data System (ADS)

    Stovern, Michael

    Wind erosion, transport and deposition of particulate matter can have significant impacts on the environment. It is observed that about 40% of the global land area and 30% of the earth's population lives in semiarid environments which are especially susceptible to wind erosion and airborne transport of contaminants. With the increased desertification caused by land use changes, anthropogenic activities and projected climate change impacts windblown dust will likely become more significant. An important anthropogenic source of windblown dust in this region is associated with mining operations including tailings impoundments. Tailings are especially susceptible to erosion due to their fine grain composition, lack of vegetative coverage and high height compared to the surrounding topography. This study is focused on emissions, dispersion and deposition of windblown dust from the Iron King mine tailings in Dewey-Humboldt, Arizona, a Superfund site. The tailings impoundment is heavily contaminated with lead and arsenic and is located directly adjacent to the town of Dewey-Humboldt. The study includes in situ field measurements, computational fluid dynamic modeling and the development of a windblown dust deposition forecasting model that predicts deposition patterns of dust originating from the tailings impoundment. Two instrumented eddy flux towers were setup on the tailings impoundment to monitor the aeolian and meteorological conditions. The in situ observations were used in conjunction with a computational fluid dynamic (CFD) model to simulate the transport of windblown dust from the mine tailings to the surrounding region. The CFD model simulations include gaseous plume dispersion to simulate the transport of the fine aerosols, while individual particle transport was used to track the trajectories of larger particles and to monitor their deposition locations. The CFD simulations were used to estimate deposition of tailings dust and identify topographic mechanisms

  3. Characterization and assessment of potential environmental risk of tailings stored in seven impoundments in the Aries river basin, Western Romania

    PubMed Central

    2013-01-01

    Background The objective of this study was to examine the potential environmental risk of tailings resulted after precious and base metal ores processing, stored in seven impoundments located in the Aries river basin, Romania. The tailings were characterized by mineralogical and elemental composition, contamination indices, acid rock drainage generation potential and water leachability of hazardous/priority hazardous metals and ions. Multivariate statistical methods were used for data interpretation. Results Tailings were found to be highly contaminated with several hazardous/priority hazardous metals (As, Cu, Cd, Pb), and pose potential contamination risk for soil, sediments, surface and groundwater. Two out of the seven studied impoundments does not satisfy the criteria required for inert wastes, shows acid rock drainage potential and thus can contaminate the surface and groundwater. Three impoundments were found to be highly contaminated with As, Pb and Cd, two with As and other two with Cu. The tailings impoundments were grouped based on the enrichment factor, geoaccumulation index, contamination factor and contamination degree of 7 hazardous/priority hazardous metals (As, Cd, Cr, Cu, Ni, Pb, Zn) considered typical for the studied tailings. Principal component analysis showed that 47% of the elemental variability was attributable to alkaline silicate rocks, 31% to acidic S-containing minerals, 12% to carbonate minerals and 5% to biogenic elements. Leachability of metals and ions was ascribed in proportion of 61% to silicates, 11% to acidic minerals and 6% to the organic matter. A variability of 18% was attributed to leachability of biogenic elements (Na, K, Cl-, NO3-) with no potential environmental risk. Pattern recognition by agglomerative hierarchical clustering emphasized the grouping of impoundments in agreement with their contamination degree and acid rock drainage generation potential. Conclusions Tailings stored in the studied impoundments were found to

  4. Elemental and mineral inventory of tailing impoundments near Pezinok, Slovakia and possible courses of action for their remediation

    NASA Astrophysics Data System (ADS)

    Majzlan, Juraj; Brecht, Björn; Lalinská, Bronislava; Chovan, Martin; Moravanský, Daniel; Uhlík, Peter

    2010-01-01

    An effective remediation strategy for a polluted site should take the absolute amount of the pollutant(s) into account. Here, we present an elemental budget for As, Sb and Fe in two tailing impoundments of the former Sb-Au deposit near Pezinok, Slovakia. The two impoundments contain 5,740×103 kg As, 6,360×103 kg Sb and 50,105×103 kg Fe. An estimated total Au content in the impoundments is 132 kg. The most abundant minerals in the tailings are quartz, illite, and chlorite. The content of carbonates in the tailings is 3.5-10.5 wt% calcite equivalent and we estimate that the carbonates are sufficiently abundant to buffer the pH at circumneutral values, up to the point when all pyrite decomposes. The possible courses of action are i) do nothing, ii) build an active barrier to capture the released As and Sb, iii) isolate the impoundments from rain and ground water and iv) use the impoundments as a source of Sb and redeposit the waste in a safer form. The simplest approach is to do nothing, which seems to be the most likely course of events, given the current economic, political and societal state of the Slovak Republic. Although this action costs nothing in the short term, it may cause significant damage to the environment, especially to the alluvial sediments and associated water resources in the long term.

  5. Geochemical characterisation of seepage and drainage water quality from two sulphide mine tailings impoundments: Acid mine drainage versus neutral mine drainage

    USGS Publications Warehouse

    Heikkinen, P.M.; Raisanen, M.L.; Johnson, R.H.

    2009-01-01

    Seepage water and drainage water geochemistry (pH, EC, O2, redox, alkalinity, dissolved cations and trace metals, major anions, total element concentrations) were studied at two active sulphide mine tailings impoundments in Finland (the Hitura Ni mine and Luikonlahti Cu mine/talc processing plant). The data were used to assess the factors influencing tailings seepage quality and to identify constraints for water treatment. Changes in seepage water quality after equilibration with atmospheric conditions were evaluated based on geochemical modelling. At Luikonlahti, annual and seasonal changes were also studied. Seepage quality was largely influenced by the tailings mineralogy, and the serpentine-rich, low sulphide Hitura tailings produced neutral mine drainage with high Ni. In contrast, drainage from the high sulphide, multi-metal tailings of Luikonlahti represented typical acid mine drainage with elevated contents of Zn, Ni, Cu, and Co. Other factors affecting the seepage quality included weathering of the tailings along the seepage flow path, process water input, local hydrological settings, and structural changes in the tailings impoundment. Geochemical modelling showed that pH increased and some heavy metals were adsorbed to Fe precipitates after net alkaline waters equilibrated with the atmosphere. In the net acidic waters, pH decreased and no adsorption occurred. A combination of aerobic and anaerobic treatments is proposed for Hitura seepages to decrease the sulphate and metal loading. For Luikonlahti, prolonged monitoring of the seepage quality is suggested instead of treatment, since the water quality is still adjusting to recent modifications to the tailings impoundment.

  6. Geochemical and mineralogical characterization of a neutral, low-sulfide/high-carbonate tailings impoundment, Markušovce, eastern Slovakia.

    PubMed

    Hiller, Edgar; Petrák, Marián; Tóth, Roman; Lalinská-Voleková, Bronislava; Jurkovič, L'ubomír; Kučerová, Gabriela; Radková, Anežka; Sottník, Peter; Vozár, Jaroslav

    2013-11-01

    Tailings deposits generated from mining activities represent a potential risk for the aquatic environment through the release of potentially toxic metals and metalloids occurring in a variety of minerals present in the tailings. Physicochemical and mineralogical characteristics of tailings such as total concentrations of chemical elements, pH, ratio of acid-producing to acid-neutralizing minerals, and primary and secondary mineral phases are very important factors that control the actual release of potentially toxic metals and metalloids from the tailings to the environment. The aims of this study are the determination of geochemical and mineralogical characteristics of tailings deposited in voluminous impoundment situated near the village of Markušovce (eastern Slovakia) and identification of the processes controlling the mobility of selected toxic metals (Cu, Hg) and metalloids (As, Sb). The studied tailings have unique features in comparison with the other tailings investigated previously because of the specific mineral assemblage primarily consisting of barite, siderite, quartz, and minor sulfides. To meet the aims, samples of the tailings were collected from 3 boreholes and 15 excavated pits and subjected to bulk geochemical analyses (i.e., determination of chemical composition, pH, Eh, acid generation, and neutralization potentials) combined with detailed mineralogical characterization using optical microscopy, X-ray diffraction (XRD), electron microprobe analysis (EMPA), and micro-X-ray diffraction (μ-XRD). Additionally, the geochemical and mineralogical factors controlling the transfer of potentially toxic elements from tailings to waters were also determined using short-term batch test (European norm EN 12457), sampling of drainage waters and speciation-equilibrium calculations performed with PHREEQC. The tailings mineral assemblage consists of siderite, barite, quartz, and dolomite. Sulfide minerals constitute only a minor proportion of the tailings

  7. The role of cassiterite controlling arsenic mobility in an abandoned stanniferous tailings impoundment at Llallagua, Bolivia.

    PubMed

    Romero, Francisco Martín; Canet, Carles; Alfonso, Pura; Zambrana, Rubén N; Soto, Nayelli

    2014-05-15

    The surface water contamination by potentially toxic elements (PTE) leached from mine tailings is a major environmental concern. However, the formation of insoluble solid phases can control the mobility of PTE, with subsequent decrease of the risk that tailings suppose to the environment. We characterized the tailings from a tin inactive mine in Llallagua, Bolivia in order to assess the risk for surface water quality. These tailings contain high concentrations of PTE, with up to 94,344 mg/kg Fe, 9,135 mg/kg Sn, 4,606 mg/kg As, 1,362 mg/kg Cu, 1,220 mg/kg Zn, 955 mg/kg Pb and 151 mg/kg Cd. Oxidation of sulfide minerals in these tailings generates acid leachates (pH=2.5-3.5), rich in SO4(2-) and dissolved PTE, thereby releasing contaminants to the surface waters. Nevertheless, the concentrations of dissolved Sn, As and Pb in acid leachates are low (Sn<0.01 mg/L; As=0.25-2.55 mg/L; Pb<0.05 mg/L). This indicates that, for the most part, Sn, As and Pb are being retained by the solid phases in the impoundment, so that these elements are not reaching the surface waters. Fe-bearing cassiterite-an insoluble and weathering-resistant oxide mineral-is abundant in the studied tailing deposits; it should be the main solid phase controlling Sn and As mobility in the impoundment. Additionally, jarosite and plumbojarosite, identified among the secondary minerals, could also play an important role controlling the mobility of As and Pb. Taking into account (a) the low solubility constants of cassiterite (Ksp=10(-64.2)), jarosite (Ksp=10(-11)) and plumbojarosite (Ksp=10(-28.66)), and (b) the stability of these minerals under acidic conditions, we can conclude that they control the long-term fate of Sn, As and Pb in the studied tailings. Copyright © 2014 Elsevier B.V. All rights reserved.

  8. Microbial communities in a porphyry copper tailings impoundment and their impact on the geochemical dynamics of the mine waste.

    PubMed

    Diaby, Nouhou; Dold, Bernhard; Pfeifer, Hans-Rudolf; Holliger, Christof; Johnson, D Barrie; Hallberg, Kevin B

    2007-02-01

    The distribution and diversity of acidophilic bacteria of a tailings impoundment at the La Andina copper mine, Chile, was examined. The tailings have low sulfide (1.7% pyrite equivalent) and carbonate (1.4% calcite equivalent) contents and are stratified into three distinct zones: a surface (0-70-80 cm) 'oxidation zone' characterized by low-pH (2.5-4), a 'neutralization zone' (70-80 to 300-400 cm) and an unaltered 'primary zone' below 400 cm. A combined cultivation-dependent and biomolecular approach (terminal restriction enzyme fragment length polymorphism and 16S rRNA clone library analysis) was used to characterize the indigenous prokaryotic communities in the mine tailings. Total cell counts showed that the microbial biomass was greatest in the top 125 cm of the tailings. The largest numbers of bacteria (10(9) g(-1) dry weight of tailings) were found at the oxidation front (the junction between the oxidation and neutralization zones), where sulfide minerals and oxygen were both present. The dominant iron-/sulfur-oxidizing bacteria identified at the oxidation front included bacteria of the genus Leptospirillum (detected by molecular methods), and Gram-positive iron-oxidizing acidophiles related to Sulfobacillus (identified both by molecular and cultivation methods). Acidithiobacillus ferrooxidans was also detected, albeit in relatively small numbers. Heterotrophic acidophiles related to Acidobacterium capsulatum were found by molecular methods, while another Acidobacterium-like bacterium and an Acidiphilium sp. were isolated from oxidation zone samples. A conceptual model was developed, based on microbiological and geochemical data derived from the tailings, to account for the biogeochemical evolution of the Piuquenes tailings impoundment.

  9. Sulfide oxidation and acid mine drainage formation within two active tailings impoundments in the Golden Quadrangle of the Apuseni Mountains, Romania.

    PubMed

    Sima, Mihaela; Dold, Bernhard; Frei, Linda; Senila, Marin; Balteanu, Dan; Zobrist, Jurg

    2011-05-30

    Sulfidic mine tailings have to be classified as one of the major source of hazardous materials leading to water contamination. This study highlights the processes leading to sulfide oxidation and acid mine drainage (AMD) formation in the active stage of two tailings impoundments located in the southern part of the Apuseni Mountains, in Romania, a well-known region for its long-term gold-silver and metal mining activity. Sampling was undertaken when both impoundments were still in operation in order to assess their actual stage of oxidation and long-term behavior in terms of the potential for acid mine drainage generation. Both tailings have high potential for AMD formation (2.5 and 3.7 wt.% of pyrite equivalent, respectively) with lesser amount of carbonates (5.6 and 3.6 wt.% of calcite equivalent) as neutralization potential (ABA=-55.6 and -85.1 tCaCO(3)/1000 t ) and showed clear signs of sulfide oxidation yet during operation. Sequential extraction results indicate a stronger enrichment and mobility of elements in the oxidized tailings: Fe as Fe(III) oxy-hydroxides and oxides (transformation from sulfide minerals, leaching in oxidation zone), Ca mainly in water soluble and exchangeable form where gypsum and calcite are dissolved and higher mobility of Cu for Ribita and Pb for Mialu. Two processes leading to the formation of mine drainage at this stage could be highlighted (1) a neutral Fe(II) plume forming in the impoundment with ferrihydrite precipitation at its outcrop and (2) acid mine drainage seeping in the unsaturated zone of the active dam, leading to the formation of schwertmannite at its outcrop. Copyright © 2011 Elsevier B.V. All rights reserved.

  10. Hypersalinity reduces the risk of cyanide toxicosis to insectivorous bats interacting with wastewater impoundments at gold mines.

    PubMed

    Griffiths, Stephen R; Donato, David B; Lumsden, Linda F; Coulson, Graeme

    2014-01-01

    Wildlife and livestock that ingest bioavailable cyanide compounds in gold mining tailings dams are known to experience cyanide toxicosis. Elevated levels of salinity in open impoundments have been shown to prevent wildlife cyanide toxicosis by reducing drinking and foraging. This finding appears to be consistent for diurnal wildlife interacting with open impoundments, however the risks to nocturnal wildlife of cyanide exposure are unknown. We investigated the activity of insectivorous bats in the airspace above both fresh (potable to wildlife) and saline water bodies at two gold mines in the goldfields of Western Australian. During this study, cyanide-bearing solutions stored in open impoundments at both mine sites were hypersaline (range=57,000-295,000 mg/L total dissolved solids (TDS)), well above known physiological tolerance of any terrestrial vertebrate. Bats used the airspace above each water body monitored, but were more active at fresh than saline water bodies. In addition, considerably more terminal echolocation buzz calls were recorded in the airspace above fresh than saline water bodies at both mine sites. However, it was not possible to determine whether these buzz calls corresponded to foraging or drinking bouts. No drinking bouts were observed in 33 h of thermal video footage recorded at one hypersaline tailings dam, suggesting that this water is not used for drinking. There is no information on salinity tolerances of bats, but it could be assumed that bats would not tolerate salinity in drinking water at concentrations greater than those documented as toxic for saline-adapted terrestrial wildlife. Therefore, when managing wastewater impoundments at gold mines to avoid wildlife mortalities, adopting a precautionary principle, bats are unlikely to drink solutions at salinity levels ≥50,000 mg/L TDS. © 2013 Published by Elsevier Inc.

  11. Tail mean and related robust solution concepts

    NASA Astrophysics Data System (ADS)

    Ogryczak, Włodzimierz

    2014-01-01

    Robust optimisation might be viewed as a multicriteria optimisation problem where objectives correspond to the scenarios although their probabilities are unknown or imprecise. The simplest robust solution concept represents a conservative approach focused on the worst-case scenario results optimisation. A softer concept allows one to optimise the tail mean thus combining performances under multiple worst scenarios. We show that while considering robust models allowing the probabilities to vary only within given intervals, the tail mean represents the robust solution for only upper bounded probabilities. For any arbitrary intervals of probabilities the corresponding robust solution may be expressed by the optimisation of appropriately combined mean and tail mean criteria thus remaining easily implementable with auxiliary linear inequalities. Moreover, we use the tail mean concept to develope linear programming implementable robust solution concepts related to risk averse optimisation criteria.

  12. Windblown Dust Deposition Forecasting and Spread of Contamination around Mine Tailings.

    PubMed

    Stovern, Michael; Guzmán, Héctor; Rine, Kyle P; Felix, Omar; King, Matthew; Ela, Wendell P; Betterton, Eric A; Sáez, Avelino Eduardo

    2016-02-01

    Wind erosion, transport and deposition of windblown dust from anthropogenic sources, such as mine tailings impoundments, can have significant effects on the surrounding environment. The lack of vegetation and the vertical protrusion of the mine tailings above the neighboring terrain make the tailings susceptible to wind erosion. Modeling the erosion, transport and deposition of particulate matter from mine tailings is a challenge for many reasons, including heterogeneity of the soil surface, vegetative canopy coverage, dynamic meteorological conditions and topographic influences. In this work, a previously developed Deposition Forecasting Model (DFM) that is specifically designed to model the transport of particulate matter from mine tailings impoundments is verified using dust collection and topsoil measurements. The DFM is initialized using data from an operational Weather Research and Forecasting (WRF) model. The forecast deposition patterns are compared to dust collected by inverted-disc samplers and determined through gravimetric, chemical composition and lead isotopic analysis. The DFM is capable of predicting dust deposition patterns from the tailings impoundment to the surrounding area. The methodology and approach employed in this work can be generalized to other contaminated sites from which dust transport to the local environment can be assessed as a potential route for human exposure.

  13. Windblown Dust Deposition Forecasting and Spread of Contamination around Mine Tailings

    PubMed Central

    Stovern, Michael; Guzmán, Héctor; Rine, Kyle P.; Felix, Omar; King, Matthew; Ela, Wendell P.; Betterton, Eric A.; Sáez, Avelino Eduardo

    2017-01-01

    Wind erosion, transport and deposition of windblown dust from anthropogenic sources, such as mine tailings impoundments, can have significant effects on the surrounding environment. The lack of vegetation and the vertical protrusion of the mine tailings above the neighboring terrain make the tailings susceptible to wind erosion. Modeling the erosion, transport and deposition of particulate matter from mine tailings is a challenge for many reasons, including heterogeneity of the soil surface, vegetative canopy coverage, dynamic meteorological conditions and topographic influences. In this work, a previously developed Deposition Forecasting Model (DFM) that is specifically designed to model the transport of particulate matter from mine tailings impoundments is verified using dust collection and topsoil measurements. The DFM is initialized using data from an operational Weather Research and Forecasting (WRF) model. The forecast deposition patterns are compared to dust collected by inverted-disc samplers and determined through gravimetric, chemical composition and lead isotopic analysis. The DFM is capable of predicting dust deposition patterns from the tailings impoundment to the surrounding area. The methodology and approach employed in this work can be generalized to other contaminated sites from which dust transport to the local environment can be assessed as a potential route for human exposure. PMID:29082035

  14. Subpart W: National Emission Standards for Radon Emissions From Operating Mill Tailings

    EPA Pesticide Factsheets

    Subpart W limits the radon-222 emissions rate from uranium tailings piles to 20 picocuries per square meter per second and requires that new tailings impoundments meet certain work practice standards.

  15. The formation and potential importance of cemented layers in inactive sulfide mine tailings

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Blowes, D.W.; Reardon, E.J.; Cherry, J.A.

    Investigations of inactive sulfide-rich tailings impoundments at the Heath Steele (New Brunswick) and Waite Amulet (Quebec) minesites have revealed two distinct types of cemented layers or hardpans. That at Heath Steele is 10-15 cm thick, occurs 20-30 cm below the depth of active oxidation, is continuous throughout the tailings impoundment, and is characterized by cementation of tailings by gypsum and Fe(II) solid phases, principally melanterite. Hardpan at the Waite Amulet site is only 1-5 cm thick, is laterally discontinuous (10-100 cm), occurs at the depth of active oxidation, and is characterized by cementation of tailings by Fe(III) minerals, principally goethite,more » lepidocrocite, ferrihydrite, and jarosite. At Heath Steele, an accumulation of gas-phase CO{sub 2}, of up to 60{percent} of the pore gas, occurs below the hardpan. The calculated diffusivity of the hardpan layer is only about 1/100 that of the overlying, uncemented tailings. The pore-water chemistry at Heath Steele has changed little over a 10-year period, suggesting that the cemented layer restricts the movement of dissolved metals through the tailings and also acts as a zone of metal accumulation. Generation of a cemented layer therefore has significant environmental and economic implications. It is likely that, in sulfide-rich tailings impoundments, the addition of carbonate-rich buffering material during the late stages of tailings deposition would enhance the formation of hardpan layers.« less

  16. Historic mills and mill tailings as potential sources of contamination in and near the Humboldt River basin, northern Nevada. Chapter D.

    USGS Publications Warehouse

    Nash, J. Thomas; Stillings, Lisa L.

    2003-01-01

    Reconnaissance field studies of 40 mining districts in and near the Humboldt River basin have identified 83 mills and associated tailings impoundments and several other kinds of mineral-processing facilities (smelters, mercury retorts, heap-leach pads) related to historic mining. The majority of the mills and tailings sites are not recorded in the literature. All tailings impoundments show evidence of substantial amounts of erosion. At least 11 tailings dams were breached by flood waters, carrying fluvial tailings 1 to 15 km down canyons and across alluvial fans. Most of the tailings sites are dry most of the year, but some are near streams. Tailings that are wet for part of the year do not appear to be reacting significantly with those waters because physical factors such as clay layers and hard-pan cement appear to limit permeability and release of metals to surface waters. The major impact of mill tailings on surface- water quality may be brief flushes of runoff during storm events that carry acid and metals released from soluble mineral crusts. Small ephemeral ponds and puddles that tend to collect in trenches and low areas on tailings impoundments tend to be acidic and extremely enriched in metals, in part through cycles of evaporation. Ponded water that is rich in salts and metals could be acutely toxic to unsuspecting animals. Rare extreme storms have the potential to cause catastrophic failure of tailings impoundments, carry away metals in stormwaters, and transport tailings as debris flows for 1 to 15 km. In most situations these stormwaters and transported tailings could impact wildlife but probably would impact few or no people or domes-tic water wells. Because all identified historic tailings sites are several kilometers or more from the Humboldt River and major tributaries, tailings probably have no measurable impact on water quality in the main stem of the Humboldt River.

  17. Velocity field measurements in tailings dam failure experiments using a combined PIV-PTV approach

    USDA-ARS?s Scientific Manuscript database

    Tailings dams are built to impound mining waste, also called tailings, which consists of a mixture of fine-sized sediments and water contaminated with some hazardous chemicals used for extracting the ore by leaching. Non-Newtonian flow of sediment-water mixture resulting from a failure of tailings d...

  18. Modelling of Fluidised Geomaterials: The Case of the Aberfan and the Gypsum Tailings Impoundment Flowslides

    PubMed Central

    Dutto, Paola; Stickle, Miguel Martin; Pastor, Manuel; Manzanal, Diego; Yague, Angel; Moussavi Tayyebi, Saeid; Lin, Chuan; Elizalde, Maria Dolores

    2017-01-01

    The choice of a pure cohesive or a pure frictional viscoplastic model to represent the rheological behaviour of a flowslide is of paramount importance in order to obtain accurate results for real cases. The principal goal of the present work is to clarify the influence of the type of viscous model—pure cohesive versus pure frictional—with the numerical reproduction of two different real flowslides that occurred in 1966: the Aberfan flowslide and the Gypsum tailings impoundment flowslide. In the present work, a depth-integrated model based on the v-pw Biot–Zienkiewicz formulation, enhanced with a diffusion-like equation to account for the pore pressure evolution within the soil mass, is applied to both 1966 cases. For the Aberfan flowslide, a frictional viscous model based on Perzyna viscoplasticity is considered, while a pure cohesive viscous model (Bingham model) is considered for the case of the Gypsum flowslide. The numerical approach followed is the SPH method, which has been enriched by adding a 1D finite difference grid to each SPH node in order to improve the description of the pore water evolution in the propagating mixture. The results obtained by the performed simulations are in agreement with the documentation obtained through the UK National Archive (Aberfan flowslide) and the International Commission of large Dams (Gypsum flowslide). PMID:28772924

  19. Design, construction and management of tailings storage facilities for surface disposal in China: case studies of failures.

    PubMed

    Wei, Zuoan; Yin, Guangzhi; Wang, J G; Wan, Ling; Li, Guangzhi

    2013-01-01

    Rapid development of China's economy demands for more mineral resources. At the same time, a vast quantity of mine tailings, as the waste byproduct of mining and mineral processing, is being produced in huge proportions. Tailings impoundments play an important role in the practical surface disposal of these large quantities of mining waste. Historically, tailings were relatively small in quantity and had no commercial value, thus little attention was paid to their disposal. The tailings were preferably discharged near the mines and few tailings storage facilities were constructed in mainland China. This situation has significantly changed since 2000, because the Chinese economy is growing rapidly and Chinese regulations and legislation require that tailings disposal systems must be ready before the mining operation begins. Consequently, data up to 2008 shows that more than 12 000 tailings storage facilities have been built in China. This paper reviews the history of tailings disposal in China, discusses three cases of tailings dam failures and explores failure mechanisms, and the procedures commonly used in China for planning, design, construction and management of tailings impoundments. This paper also discusses the current situation, shortcomings and key weaknesses, as well as future development trends for tailings storage facilities in China.

  20. 30 CFR 77.216-4 - Water, sediment or slurry impoundments and impounding structures; reporting requirements...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Water, sediment or slurry impoundments and....216-4 Water, sediment or slurry impoundments and impounding structures; reporting requirements... of the initial plan approval, the person owning, operating, or controlling a water, sediment, or...

  1. 30 CFR 77.216-4 - Water, sediment or slurry impoundments and impounding structures; reporting requirements...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Water, sediment or slurry impoundments and....216-4 Water, sediment or slurry impoundments and impounding structures; reporting requirements... of the initial plan approval, the person owning, operating, or controlling a water, sediment, or...

  2. 30 CFR 77.216-4 - Water, sediment or slurry impoundments and impounding structures; reporting requirements...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Water, sediment or slurry impoundments and....216-4 Water, sediment or slurry impoundments and impounding structures; reporting requirements... of the initial plan approval, the person owning, operating, or controlling a water, sediment, or...

  3. Remote sensing supported surveillance and characterization of tailings behavior at a gold mine site, Finland.

    NASA Astrophysics Data System (ADS)

    Rauhala, Anssi; Tuomela, Anne; Rossi, Pekka M.; Davids, Corine

    2017-04-01

    The management of vast amounts of tailings produced is one of the key issues in mining operations. The effective and economic disposal of the waste requires knowledge concerning both basic physical properties of the tailings as well as more complex aspects such as consolidation behavior. The behavior of tailings in itself is a very complex issue that can be affected by flocculation, sedimentation, consolidation, segregation, deposition, freeze-thaw, and desiccation phenomena. The utilization of remote sensing in an impoundment-scale monitoring of tailings could benefit the management of tailings, and improve our knowledge on tailings behavior. In order to gain better knowledge of tailings behavior in cold climate, we have utilized both modern remote sensing techniques and more traditional in situ and laboratory measurements in characterizing thickened gold tailings behavior at a Finnish gold mine site, where the production has been halted due to low gold prices. The remote sensing measurements consisted of elevation datasets collected from unmanned aerial vehicles during summers 2015 and 2016, and a further campaign is planned for the summer 2017. The ongoing traditional measurements include for example particle-size distribution, frost heave, frost depth, water retention, temperature profile, and rheological measurements. Initial results from the remote sensing indicated larger than expected settlements on parts of the tailings impoundment, and also highlighted some of the complexities related to data processing. The interpretation of the results and characterization of the behavior is in this case complicated by possible freeze-thaw effects and potential settlement of the impoundment bottom structure consisting of natural peat. Experiments with remote sensing and unmanned aerial vehicles indicate that they could offer potential benefits in frequent mine site monitoring, but there is a need towards more robust and streamlined data acquisition and processing. The

  4. River impoundment and sunfish growth

    Treesearch

    Andrew L. Rypel

    2011-01-01

    Impoundment of rivers by dams is widespread and one of the most devastating anthropogenic impacts to freshwater environments. Linking theoretical and applied research on river impoundment requires an improved capacity for predicting how varying degrees of impoundment affects a range of species. Here, growth of 14 North American sunfish species resilient to river...

  5. 40 CFR 268.4 - Treatment surface impoundment exemption.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... impoundment or series of impoundments provided that: (1) Treatment of such wastes occurs in the impoundments... under § 264.13 or § 265.13, must be designed such that representative samples of the sludge and the... this chapter. If the volume of liquid flowing through the impoundment or series of impoundments...

  6. 40 CFR 268.4 - Treatment surface impoundment exemption.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... impoundment or series of impoundments provided that: (1) Treatment of such wastes occurs in the impoundments... under § 264.13 or § 265.13, must be designed such that representative samples of the sludge and the... this chapter. If the volume of liquid flowing through the impoundment or series of impoundments...

  7. 40 CFR 268.4 - Treatment surface impoundment exemption.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... impoundment or series of impoundments provided that: (1) Treatment of such wastes occurs in the impoundments... under § 264.13 or § 265.13, must be designed such that representative samples of the sludge and the... this chapter. If the volume of liquid flowing through the impoundment or series of impoundments...

  8. 40 CFR 268.4 - Treatment surface impoundment exemption.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... impoundment or series of impoundments provided that: (1) Treatment of such wastes occurs in the impoundments... under § 264.13 or § 265.13, must be designed such that representative samples of the sludge and the... this chapter. If the volume of liquid flowing through the impoundment or series of impoundments...

  9. Spectral induced polarization (SIP) response of mine tailings.

    PubMed

    Placencia-Gómez, Edmundo; Parviainen, Annika; Slater, Lee; Leveinen, Jussi

    2015-02-01

    Mine tailings impoundments are a source of leachates known as acid mine drainage (AMD) which can pose a contamination risk for surrounding surface and groundwater. Methodologies which can help management of this environmental issue are needed. We carried out a laboratory study of the spectral induced polarization (SIP) response of tailings from the Haveri Au-Cu mine, SW Finland. The primary objectives were, (1) to determine possible correlations between SIP parameters and textural properties associated with oxidative-weathering mechanisms, mineralogical composition and metallic content, and (2) to evaluate the effects of the pore water chemistry on SIP parameters associated with redox-inactive and redox-active electrolytes varying in molar concentration, conductivity and pH. The Haveri tailings exhibit well defined relaxation spectra between 100 and 10,000Hz. The relaxation magnitudes are governed by the in-situ oxidative-weathering conditions on sulphide mineral surfaces contained in the tailings, and decrease with the oxidation degree. The oxidation-driven textural variation in the tailings results in changes to the frequency peak of the phase angle, the imaginary conductivity and chargeability, when plotted versus the pore water conductivity. In contrast, the real and the formation electrical conductivity components show a single linear dependence on the pore water conductivity. The increase of the pore water conductivity (dominated by the increase of ions concentration in solution) along with a transition to acidic conditions shifts the polarization peak towards higher frequencies. These findings show the unique sensitivity of the SIP method to potentially discriminate AMD discharges from reactive oxidation zones in tailings, suggesting a significant advantage for monitoring threatened aquifers. Copyright © 2014 Elsevier B.V. All rights reserved.

  10. Spectral induced polarization (SIP) response of mine tailings

    NASA Astrophysics Data System (ADS)

    Placencia-Gómez, Edmundo; Parviainen, Annika; Slater, Lee; Leveinen, Jussi

    2015-02-01

    Mine tailings impoundments are a source of leachates known as acid mine drainage (AMD) which can pose a contamination risk for surrounding surface and groundwater. Methodologies which can help management of this environmental issue are needed. We carried out a laboratory study of the spectral induced polarization (SIP) response of tailings from the Haveri Au-Cu mine, SW Finland. The primary objectives were, (1) to determine possible correlations between SIP parameters and textural properties associated with oxidative-weathering mechanisms, mineralogical composition and metallic content, and (2) to evaluate the effects of the pore water chemistry on SIP parameters associated with redox-inactive and redox-active electrolytes varying in molar concentration, conductivity and pH. The Haveri tailings exhibit well defined relaxation spectra between 100 and 10,000 Hz. The relaxation magnitudes are governed by the in-situ oxidative-weathering conditions on sulphide mineral surfaces contained in the tailings, and decrease with the oxidation degree. The oxidation-driven textural variation in the tailings results in changes to the frequency peak of the phase angle, the imaginary conductivity and chargeability, when plotted versus the pore water conductivity. In contrast, the real and the formation electrical conductivity components show a single linear dependence on the pore water conductivity. The increase of the pore water conductivity (dominated by the increase of ions concentration in solution) along with a transition to acidic conditions shifts the polarization peak towards higher frequencies. These findings show the unique sensitivity of the SIP method to potentially discriminate AMD discharges from reactive oxidation zones in tailings, suggesting a significant advantage for monitoring threatened aquifers.

  11. 30 CFR 77.216 - Water, sediment, or slurry impoundments and impounding structures; general.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Water, sediment, or slurry impoundments and... WORK AREAS OF UNDERGROUND COAL MINES Surface Installations § 77.216 Water, sediment, or slurry... structures which impound water, sediment, or slurry shall be required if such an existing or proposed...

  12. 30 CFR 77.216 - Water, sediment, or slurry impoundments and impounding structures; general.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Water, sediment, or slurry impoundments and... WORK AREAS OF UNDERGROUND COAL MINES Surface Installations § 77.216 Water, sediment, or slurry... structures which impound water, sediment, or slurry shall be required if such an existing or proposed...

  13. 30 CFR 816.49 - Impoundments.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ..., prudent, engineering practices and any design criteria established by the regulatory authority. The... surrounding landowners for agricultural, industrial, recreational, or domestic uses. (6) The impoundment will... safely removed in accordance with current, prudent, engineering practices. Such an impoundment shall be...

  14. 30 CFR 816.49 - Impoundments.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ..., prudent, engineering practices and any design criteria established by the regulatory authority. The... surrounding landowners for agricultural, industrial, recreational, or domestic uses. (6) The impoundment will... safely removed in accordance with current, prudent, engineering practices. Such an impoundment shall be...

  15. 30 CFR 816.49 - Impoundments.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ..., prudent, engineering practices and any design criteria established by the regulatory authority. The... surrounding landowners for agricultural, industrial, recreational, or domestic uses. (6) The impoundment will... safely removed in accordance with current, prudent, engineering practices. Such an impoundment shall be...

  16. 30 CFR 816.49 - Impoundments.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ..., prudent, engineering practices and any design criteria established by the regulatory authority. The... surrounding landowners for agricultural, industrial, recreational, or domestic uses. (6) The impoundment will... safely removed in accordance with current, prudent, engineering practices. Such an impoundment shall be...

  17. 30 CFR 816.49 - Impoundments.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ..., prudent, engineering practices and any design criteria established by the regulatory authority. The... surrounding landowners for agricultural, industrial, recreational, or domestic uses. (6) The impoundment will... safely removed in accordance with current, prudent, engineering practices. Such an impoundment shall be...

  18. 50 CFR 28.42 - Impounding of domestic animals.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 50 Wildlife and Fisheries 8 2011-10-01 2011-10-01 false Impounding of domestic animals. 28.42... VIOLATIONS OF PARTS 25, 26, AND 27 Impoundment Procedures § 28.42 Impounding of domestic animals. (a) Any animal trespassing on the lands of any national wildlife refuge may be impounded and disposed of in...

  19. 50 CFR 28.42 - Impounding of domestic animals.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 50 Wildlife and Fisheries 9 2013-10-01 2013-10-01 false Impounding of domestic animals. 28.42... VIOLATIONS OF PARTS 25, 26, AND 27 Impoundment Procedures § 28.42 Impounding of domestic animals. (a) Any animal trespassing on the lands of any national wildlife refuge may be impounded and disposed of in...

  20. 50 CFR 28.42 - Impounding of domestic animals.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 50 Wildlife and Fisheries 9 2014-10-01 2014-10-01 false Impounding of domestic animals. 28.42... VIOLATIONS OF PARTS 25, 26, AND 27 Impoundment Procedures § 28.42 Impounding of domestic animals. (a) Any animal trespassing on the lands of any national wildlife refuge may be impounded and disposed of in...

  1. 50 CFR 28.42 - Impounding of domestic animals.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 50 Wildlife and Fisheries 6 2010-10-01 2010-10-01 false Impounding of domestic animals. 28.42... VIOLATIONS OF PARTS 25, 26, AND 27 Impoundment Procedures § 28.42 Impounding of domestic animals. (a) Any animal trespassing on the lands of any national wildlife refuge may be impounded and disposed of in...

  2. 50 CFR 28.42 - Impounding of domestic animals.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 50 Wildlife and Fisheries 9 2012-10-01 2012-10-01 false Impounding of domestic animals. 28.42... VIOLATIONS OF PARTS 25, 26, AND 27 Impoundment Procedures § 28.42 Impounding of domestic animals. (a) Any animal trespassing on the lands of any national wildlife refuge may be impounded and disposed of in...

  3. Infiltration from an impoundment for coal‐bed natural gas, Powder River Basin, Wyoming: Evolution of water and sediment chemistry

    USGS Publications Warehouse

    Healy, Richard W.; Rice, Cynthia A.; Bartos, Timothy T.; P. McKinley, Michael

    2008-01-01

    Development of coal‐bed natural gas (CBNG) in the Powder River Basin, Wyoming, has increased substantially in recent years. Among environmental concerns associated with this development is the fate of groundwater removed with the gas. A preferred water‐management option is storage in surface impoundments. As of January 2007, permits for more than 4000 impoundments had been issued within Wyoming. A study was conducted on changes in water and sediment chemistry as water from an impoundment infiltrated the subsurface. Sediment cores were collected prior to operation of the impoundment and after its closure and reclamation. Suction lysimeters were used to collect water samples from beneath the impoundment. Large amounts of chloride (12,300 kg) and nitrate (13,500 kg as N), most of which accumulated naturally in the sediments over thousands of years, were released into groundwater by infiltrating water. Nitrate was more readily flushed from the sediments than chloride. If sediments at other impoundment locations contain similar amounts of chloride and nitrate, impoundments already permitted could release over 48 × 106 kg of chloride and 52 × 106 kg of nitrate into groundwater in the basin. A solute plume with total dissolved solid (TDS) concentrations at times exceeding 100,000 mg/L was created in the subsurface. TDS concentrations in the plume were substantially greater than those in the CBNG water (about 2300 mg/L) and in the ambient shallow groundwater (about 8000 mg/L). Sulfate, sodium, and magnesium are the dominant ions in the plume. The elevated concentrations are attributed to cation‐exchange‐enhanced gypsum dissolution. As gypsum dissolves, calcium goes into solution and is exchanged for sodium and magnesium on clays. Removal of calcium from solution allows further gypsum dissolution.

  4. Surface mine impoundments as wildlife and fish habitat

    Treesearch

    Mark A. Rumble

    1989-01-01

    Unreclaimed surface mine impoundments provide poor fish and wildlife habitat. Recommendations given here for reclaiming "prelaw" impoundments and creating new impoundments could provide valuable fish and wildlife habitat if incorporated into existing laws and mine plans.

  5. 36 CFR 262.11 - Impounding of dogs.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 36 Parks, Forests, and Public Property 2 2014-07-01 2014-07-01 false Impounding of dogs. 262.11... ENFORCEMENT SUPPORT ACTIVITIES Impoundments and Removals § 262.11 Impounding of dogs. Any dog found running at large in a part of the National Forest System, which has been closed to dogs running at large, may be...

  6. 36 CFR 262.11 - Impounding of dogs.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 36 Parks, Forests, and Public Property 2 2012-07-01 2012-07-01 false Impounding of dogs. 262.11... ENFORCEMENT SUPPORT ACTIVITIES Impoundments and Removals § 262.11 Impounding of dogs. Any dog found running at large in a part of the National Forest System, which has been closed to dogs running at large, may be...

  7. 36 CFR 262.11 - Impounding of dogs.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 36 Parks, Forests, and Public Property 2 2013-07-01 2013-07-01 false Impounding of dogs. 262.11... ENFORCEMENT SUPPORT ACTIVITIES Impoundments and Removals § 262.11 Impounding of dogs. Any dog found running at large in a part of the National Forest System, which has been closed to dogs running at large, may be...

  8. 36 CFR 262.11 - Impounding of dogs.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 36 Parks, Forests, and Public Property 2 2011-07-01 2011-07-01 false Impounding of dogs. 262.11... ENFORCEMENT SUPPORT ACTIVITIES Impoundments and Removals § 262.11 Impounding of dogs. Any dog found running at large in a part of the National Forest System, which has been closed to dogs running at large, may be...

  9. 36 CFR 262.11 - Impounding of dogs.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 36 Parks, Forests, and Public Property 2 2010-07-01 2010-07-01 false Impounding of dogs. 262.11... ENFORCEMENT SUPPORT ACTIVITIES Impoundments and Removals § 262.11 Impounding of dogs. Any dog found running at large in a part of the National Forest System, which has been closed to dogs running at large, may be...

  10. 49 CFR 193.2181 - Impoundment capacity: LNG storage tanks.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... LIQUEFIED NATURAL GAS FACILITIES: FEDERAL SAFETY STANDARDS Design Impoundment Design and Capacity § 193.2181 Impoundment capacity: LNG storage tanks. Each impounding system serving an LNG storage tank must have a... 49 Transportation 3 2010-10-01 2010-10-01 false Impoundment capacity: LNG storage tanks. 193.2181...

  11. Groundwater chemistry near an impoundment for produced water, Powder River Basin, Wyoming, USA

    USGS Publications Warehouse

    Healy, R.W.; Bartos, T.T.; Rice, C.A.; McKinley, M.P.; Smith, B.D.

    2011-01-01

    The Powder River Basin is one of the largest producers of coal-bed natural gas (CBNG) in the United States. An important environmental concern in the Basin is the fate of the large amounts of groundwater extracted during CBNG production. Most of this produced water is disposed of in unlined surface impoundments. A 6-year study of groundwater flow and water chemistry at one impoundment, Skewed Reservoir, has produced the most detailed data set for any impoundment in the Basin. Data were collected from a network of 21 observation wells and three suction lysimeters. A groundwater mound formed atop bedrock within initially unsaturated, unconsolidated deposits underlying the reservoir. Heterogeneity in physical and chemical properties of sediments resulted in complex groundwater flow paths and highly variable groundwater chemistry. Sulfate, bicarbonate, sodium, and magnesium were the dominant ions in all areas, but substantial variability existed in relative concentrations; pH varied from less than 3 to more than 9, and total dissolved solids concentrations ranged from less than 5000 to greater than 100,000 mg/L. Selenium was a useful tracer of reservoir water; selenium concentrations exceeded 300 μg/L in samples obtained from 18 of the 24 sampling points. Groundwater travel time from the reservoir to a nearby alluvial aquifer (a linear distance of 177 m) was calculated at 474 days on the basis of selenium concentrations. The produced water is not the primary source of solutes in the groundwater. Naturally occurring salts and minerals within the unsaturated zone, dissolved and mobilized by infiltrating impoundment water, account for most of the solute mass in groundwater. Gypsum dissolution, cation-exchange, and pyrite oxidation appear to be important reactions. The complex geochemistry and groundwater flow paths at the study site underscore the difficulty in assessing effects of surface impoundments on water resources within the Powder River Basin.

  12. 30 CFR 817.84 - Coal mine waste: Impounding structures.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 3 2014-07-01 2014-07-01 false Coal mine waste: Impounding structures. 817.84... ACTIVITIES § 817.84 Coal mine waste: Impounding structures. New and existing impounding structures constructed of coal mine waste or intended to impound coal mine waste shall meet the requirements of § 817.81...

  13. 30 CFR 816.84 - Coal mine waste: Impounding structures.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Coal mine waste: Impounding structures. 816.84... ACTIVITIES § 816.84 Coal mine waste: Impounding structures. New and existing impounding structures constructed of coal mine waste or intended to impound coal mine waste shall meet the requirements of § 816.81...

  14. 30 CFR 816.84 - Coal mine waste: Impounding structures.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 3 2011-07-01 2011-07-01 false Coal mine waste: Impounding structures. 816.84... ACTIVITIES § 816.84 Coal mine waste: Impounding structures. New and existing impounding structures constructed of coal mine waste or intended to impound coal mine waste shall meet the requirements of § 816.81...

  15. 30 CFR 817.84 - Coal mine waste: Impounding structures.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Coal mine waste: Impounding structures. 817.84... ACTIVITIES § 817.84 Coal mine waste: Impounding structures. New and existing impounding structures constructed of coal mine waste or intended to impound coal mine waste shall meet the requirements of § 817.81...

  16. 30 CFR 816.84 - Coal mine waste: Impounding structures.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 3 2012-07-01 2012-07-01 false Coal mine waste: Impounding structures. 816.84... ACTIVITIES § 816.84 Coal mine waste: Impounding structures. New and existing impounding structures constructed of coal mine waste or intended to impound coal mine waste shall meet the requirements of § 816.81...

  17. 30 CFR 817.84 - Coal mine waste: Impounding structures.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 3 2011-07-01 2011-07-01 false Coal mine waste: Impounding structures. 817.84... ACTIVITIES § 817.84 Coal mine waste: Impounding structures. New and existing impounding structures constructed of coal mine waste or intended to impound coal mine waste shall meet the requirements of § 817.81...

  18. 30 CFR 817.84 - Coal mine waste: Impounding structures.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 3 2013-07-01 2013-07-01 false Coal mine waste: Impounding structures. 817.84... ACTIVITIES § 817.84 Coal mine waste: Impounding structures. New and existing impounding structures constructed of coal mine waste or intended to impound coal mine waste shall meet the requirements of § 817.81...

  19. 30 CFR 816.84 - Coal mine waste: Impounding structures.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 3 2014-07-01 2014-07-01 false Coal mine waste: Impounding structures. 816.84... ACTIVITIES § 816.84 Coal mine waste: Impounding structures. New and existing impounding structures constructed of coal mine waste or intended to impound coal mine waste shall meet the requirements of § 816.81...

  20. 30 CFR 817.84 - Coal mine waste: Impounding structures.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 3 2012-07-01 2012-07-01 false Coal mine waste: Impounding structures. 817.84... ACTIVITIES § 817.84 Coal mine waste: Impounding structures. New and existing impounding structures constructed of coal mine waste or intended to impound coal mine waste shall meet the requirements of § 817.81...

  1. 30 CFR 816.84 - Coal mine waste: Impounding structures.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 3 2013-07-01 2013-07-01 false Coal mine waste: Impounding structures. 816.84... ACTIVITIES § 816.84 Coal mine waste: Impounding structures. New and existing impounding structures constructed of coal mine waste or intended to impound coal mine waste shall meet the requirements of § 816.81...

  2. 30 CFR 77.216-2 - Water, sediment, or slurry impoundments and impounding structures; minimum plan requirements...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... the District Manager. (b) Any changes or modifications to plans for water, sediment, or slurry... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Water, sediment, or slurry impoundments and impounding structures; minimum plan requirements; changes or modifications; certification. 77.216-2 Section...

  3. 30 CFR 77.216-2 - Water, sediment, or slurry impoundments and impounding structures; minimum plan requirements...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... the District Manager. (b) Any changes or modifications to plans for water, sediment, or slurry... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Water, sediment, or slurry impoundments and impounding structures; minimum plan requirements; changes or modifications; certification. 77.216-2 Section...

  4. 30 CFR 77.216-2 - Water, sediment, or slurry impoundments and impounding structures; minimum plan requirements...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... the District Manager. (b) Any changes or modifications to plans for water, sediment, or slurry... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Water, sediment, or slurry impoundments and impounding structures; minimum plan requirements; changes or modifications; certification. 77.216-2 Section...

  5. 30 CFR 77.216-2 - Water, sediment, or slurry impoundments and impounding structures; minimum plan requirements...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... the District Manager. (b) Any changes or modifications to plans for water, sediment, or slurry... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Water, sediment, or slurry impoundments and impounding structures; minimum plan requirements; changes or modifications; certification. 77.216-2 Section...

  6. Effects of small impoundments on downstream crayfish assemblages

    Treesearch

    Susan B. Adams

    2013-01-01

    Dams and impoundments, both large and small, affect downstream physicochemical characteristics and up- and downstream biotic communities. I tested whether small dams and their impoundments altered downstream crayfish assemblages in northern Mississippi. I sampled crayfish and measured physicochemical variables at 4 sites downstream of impoundments (outlet sites) and 4...

  7. The impact of unconfined mine tailings in residential areas from a mining town in a semi-arid environment: Nacozari, Sonora, Mexico

    PubMed Central

    Meza-Figueroa, Diana; Maier, Raina M.; de la O-Villanueva, Margarita; Gómez-Alvarez, Agustín; Moreno-Zazueta, Alan; Rivera, Jacinto; Campillo, Alberto; Grandlic, Christopher; Anaya, Ricardo; Palafox-Reyes, Juan

    2009-01-01

    Past mining activities in northern Mexico left a legacy of delerict landscapes devoid of vegetation and seasonal formation of salt efflorescence. Metal content was measured in mine tailings, efflorescent salts, soils, road dust and residential soils to investigate contamination. Climatic effects such as heavy wind and rainfall events can have great impact on the dispersion of metals in semi-arid areas, since soils are typically sparsely vegetated. Geochemical analysis of this site revealed that even though total metal content in mine tailings was relatively low (e.g. Cu = 1000 mg kg-1), metals including Mn, Ba, Zn, and Cu were all found at significantly higher levels in efflorescence salts formed by evaporation on the tailings impoundment surface following the rainy season (e.g. Cu=68000 mg kg-1). Such efflorescent fine-grained salts are susceptible to wind erosion resulting in increased metal spread to nearby residential soils. Our results highlight the importance of seasonally dependent salt-formation and wind erosion in determining risk levels associated with potential inhalation or ingestion of airborne particulates originating from contaminated sites such as tailings impoundments. In low metal-content mine tailings located in arid and semi-arid environments, efflorescence salts could represent a human health risk and a challenge for plant establishment in mine tailings. PMID:19500816

  8. The impact of unconfined mine tailings in residential areas from a mining town in a semi-arid environment: Nacozari, Sonora, Mexico.

    PubMed

    Meza-Figueroa, Diana; Maier, Raina M; de la O-Villanueva, Margarita; Gómez-Alvarez, Agustín; Moreno-Zazueta, Alan; Rivera, Jacinto; Campillo, Alberto; Grandlic, Christopher J; Anaya, Ricardo; Palafox-Reyes, Juan

    2009-09-01

    Past mining activities in northern Mexico left a legacy of delerict landscapes devoid of vegetation and seasonal formation of salt efflorescence. Metal content was measured in mine tailings, efflorescent salts, soils, road dust, and residential soils to investigate contamination. Climatic effects such as heavy wind and rainfall events can have great impact on the dispersion of metals in semi-arid areas, since soils are typically sparsely vegetated. Geochemical analysis of this site revealed that even though total metal content in mine tailings was relatively low (e.g. Cu= 1000 mg kg(-1)), metals including Mn, Ba, Zn, and Cu were all found at significantly higher levels in efflorescence salts formed by evaporation on the tailings impoundment surface following the rainy season (e.g. Cu= 68,000 mg kg(-1)). Such efflorescent fine-grained salts are susceptible to wind erosion resulting in increased metal spread to nearby residential soils. Our results highlight the importance of seasonally dependent salt-formation and wind erosion in determining risk levels associated with potential inhalation or ingestion of airborne particulates originating from contaminated sites such as tailings impoundments. In low metal-content mine tailings located in arid and semi-arid environments, efflorescence salts could represent a human health risk and a challenge for plant establishment in mine tailings.

  9. Sulfur speciation and stable isotope trends of water-soluble sulfates in mine tailings profiles.

    PubMed

    Dold, Bernhard; Spangenberg, Jorge E

    2005-08-01

    Sulfur speciation and the sources of water-soluble sulfate in three oxidizing sulfidic mine tailings impoundments were investigated by selective dissolution and stable isotopes. The studied tailings impoundments--Piuquenes, Cauquenes, and Salvador No. 1--formed from the exploitation of the Rio Blanco/La Andina, El Teniente, and El Salvador Chilean porphyry copper deposits, which are located in Alpine, Mediterranean, and hyperarid climates, respectively. The water-soluble sulfate may originate from dissolution of primary ore sulfates (e.g., gypsum, anhydrite, jarosite) or from oxidation of sulfide minerals exposed to aerobic conditions during mining activity. With increasing aridity and decreasing pyrite content of the tailings, the sulfur speciation in the unsaturated oxidation zones showed a trend from dominantly Fe(III) oxyhydroxide fixed sulfate (e.g., jarosite and schwertmannite) in Piuquenes toward increasing presence of water-soluble sulfate at Cauquenes and Salvador No. 1. In the saturated primary zones, sulfate is predominantly present in water-soluble form (mainly as anhydrite and/or gypsum). In the unsaturated zone at Piuquenes and Cauquenes, the delta34S(SO4)values ranged from +0.5 per thousand to +2.0 per thousand and from -0.4 per thousand to +1.4 per thousand Vienna Canyon Diablo Troilite (V-CDT), respectively, indicating a major sulfate source from pyrite oxidation (delta34S(pyrite) = -1.1 per thousand and -0.9 per thousand). In the saturated zone at Piuquenes and Cauquenes, the values ranged from -0.8 per thousand to +0.3 per thousand and from +2.2 per thousand to +3.9 per thousand, respectively. At Cauquenes the 34S enrichment in the saturated zone toward depth indicates the increasing contribution of isotopically heavy dissolved sulfate from primary anhydrite (approximately +10.9 per thousand). At El Salvador No. 1, the delta34S(SO4) average value is -0.9 per thousand, suggesting dissolution of supergene sulfate minerals (jarosite, alunite, gypsum

  10. Spatial and Temporal Analysis of the Microbial Community in the Tailings of a Pb-Zn Mine Generating Acidic Drainage ▿ †

    PubMed Central

    Huang, Li-Nan; Zhou, Wen-Hua; Hallberg, Kevin B.; Wan, Cai-Yun; Li, Jie; Shu, Wen-Sheng

    2011-01-01

    Analysis of spatial and temporal variations in the microbial community in the abandoned tailings impoundment of a Pb-Zn mine revealed distinct microbial populations associated with the different oxidation stages of the tailings. Although Acidithiobacillus ferrooxidans and Leptospirillum spp. were consistently present in the acidic tailings, acidophilic archaea, mostly Ferroplasma acidiphilum, were predominant in the oxidized zones and the oxidation front, indicating their importance to generation of acid mine drainage. PMID:21705549

  11. Microbiological Water Quality of Impoundments: A Literature Review.

    DTIC Science & Technology

    1982-12-01

    A123-470 MICROBIOLOGICAL WATER QUALITY OF IMPOUNDMENTS:A i/i LITERATURE REYIEU(U) TEX S UNJY AT DALLAS RICHRDSON G BURTON DEC 82 NES/MP/E-82-6...REPORT G PERIOD COVERED . MICROBIOLOGICAL WATER QUALITY OF IMPOUNDMENTS: Final report A LITERATURE REVIEW 6. PERFORMING ORG. REPORT NUMBER 7. AUTHOR...Va. 22151. IS. KEY WORDS (Continue an reverse side It necessary mid Identify by black numnber) Bacteria Water quality S Impoundments Water sampling

  12. 40 CFR 264.1085 - Standards: Surface impoundments.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... the surface impoundment by installing and operating either of the following: (1) A floating membrane... from a surface impoundment using a floating membrane cover shall meet the requirements specified in... floating membrane cover designed to meet the following specifications: (i) The floating membrane cover...

  13. Survey of intersex largemouth bass from impoundments in Georgia USA

    USGS Publications Warehouse

    Kellock, Kristen A.; Trushel, Brittany E.; Ely, Patrick C.; Jennings, Cecil A.; Bringolf, Robert B.

    2015-01-01

    Intersex fish are increasingly being reported worldwide, primarily in rivers that receive treated wastewater, but few studies have investigated intersex in waters that do not receive wastewater. In a recent reconnaissance survey of intersex fish in North America, a high rate of intersex was reported for Largemouth Bass Micropterus salmoides in some southeastern U.S. rivers; however, the occurrence of intersex in impoundments has not been well described, especially on a statewide scale. Therefore, our objective for this project was to survey the occurrence of intersex Largemouth Bass in a variety of impoundment habitats across Georgia. Largemouth Bass were collected from 11 impoundments without direct municipal or agricultural wastewater inputs. Gonads from all male Largemouth Bass were evaluated for the incidence and severity of the intersex condition based on presence and arrangement of testicular oocytes. Overall 48% of male Largemouth Bass collected from impoundments were intersex, which was found in 9 of the 11 impoundments. Among impoundments, incidence of intersex ranged from 0 to 82% of the males sampled and surface area of the impoundment was a significant predictor of intersex incidence. Intersex fish were smaller than normal males, but population-level effects of intersex and causative factors of endocrine disruption in the impoundments remain unknown. The high incidence of intersex males in small impoundments demonstrates that the condition is not confined to rivers and suggests that factors other than those previously associated with intersex (i.e., municipal wastewater) may be involved.

  14. Application of an integrated biomarker response index to assess ground water contamination in the vicinity of a rare earth mine tailings site.

    PubMed

    Si, Wantong; He, Xiaoying; Li, Ailing; Liu, Li; Li, Jisheng; Gong, Donghui; Liu, Juan; Liu, Jumei; Shen, Weishou; Zhang, Xuefeng

    2016-09-01

    We utilized a multi-biomarker approach (Integrated Biomarker Response version 2, IBRv2) to investigate the scope and dispersion of groundwater contamination surrounding a rare earth mine tailings impoundment. Parameters of SD rat included in our IBRv2 analyses were glutathione levels, superoxide dismutase, catalase, and glutathione peroxidase activities, total anti-oxidative capacity, chromosome aberration, and micronucleus formation. The concentration of 20 pollutants including Cl(-), SO4 (2-), Na(+), K(+), Mg(2+), Ca(2+), TH, CODMn, As, Se, TDS, Be, Mn, Co, Ni, Cu, Zn, Mo, Cd, and Pb in the groundwater were also analyzed. The results of this study indicated that groundwater polluted by tailings impoundment leakage exhibited significant ecotoxicological effects. The selected biomarkers responded sensitively to groundwater pollution. Analyses showed a significant relationship between IBRv2 values and the Nemerow composite index. IBRv2 could serve as a sensitive ecotoxicological diagnosis method for assessing groundwater contamination in the vicinity of rare earth mine tailings. According to the trend of IBRv2 value and Nemerow composite index, the maximum diffusion distance of groundwater pollutants from rare earth mine tailings was approximately 5.7 km.

  15. Water impoundments for wildlife: a habitat management workshop.

    Treesearch

    M. Dean Knighton

    1985-01-01

    Discusses many aspects of managing wildlife water impoundments in the western Great Lakes region. Political and biological justification, where and how to build impoundments, water-level management options, vegetation, water quality, invertebrate populations, and research needs are all considered.

  16. 2015 Uranium Mill Tailings Radiation Control Act (UMTRCA) Title ll Annual Report, L-Bar, New Mexico Disposal Site

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Frazier, William; Johnson, Dick

    The L-Bar, New Mexico, Uranium Mill Tailings Radiation Control Act (UMTRCA) Title II Disposal Site was inspected on August 18, 2015. The tailings impoundment was in excellent condition. Erosion and vegetation measurements to monitor the condition of the impoundment cover indicated that no erosion is occurring, and perennial vegetation foliar cover at the measurement plots increased substantially compared to previous years due to above-average precipitation for the year. A short segment of the perimeter fence near the site entrance was realigned in spring 2015 because a gully was undermining the fence corner. Loose fence strands at another location were repairedmore » during the inspection, and a section of fence needs to be realigned to avoid areas affected by deep gullies and sediment deposition. Inspectors identified no other maintenance needs or cause for a follow-up inspection. Groundwater monitoring is required every 3 years. The next monitoring event will be in 2016.« less

  17. The long-term environmental impacts of the Mount Polley mine tailings spill, British Columbia, Canada

    NASA Astrophysics Data System (ADS)

    Byrne, Patrick; Hudson-Edwards, Karen; Macklin, Mark; Brewer, Paul; Bird, Graham; Williams, Richard

    2015-04-01

    On the 4th August 2014 a tailings impoundment failure at the Mount Polley gold and copper mine in British Columbia, Canada, released approximately 25 million m3 of solid and liquid waste into Hazeltine Creek, Quesnel Lake and Polley Lake. The sheer volume of the tailings released caused Haseltine Creek channel to expand from 2m to over 25m in width and Polley Lake water level to rise by 1.7m. The spill also removed trees in a 900 km2 corridor either side of Hazeltine Creek. Local residents and government officials have expressed serious concerns regarding the potential long-term effects on regional biodiversity, water security and to the livelihoods of First Nation communities. Among impoundment failures, the Mount Polley disaster is unique in that the solid tailings contain an unusual mixture of metal contaminants (arsenic, copper, gold, manganese, nickel, lead, vanadium). As particulate matter is the principal carrier of metal contaminants, the spilled tailings may reside in the regional soils and sediments for 1000s of years serving as a secondary source of pollution. The environmental risk posed by the spilled tailings is compounded by the location of the spill in a mountainous forested catchment, affected by severe winters with prominent spring snow melts that have the potential to remobilise very large quantities of spilled tailings. No data currently exist on the short- to long-term behaviour of these tailings in soils and sediments and the effects of the clean-up operations on their behaviour in this type of river environment. In this study, we adopt a multidisciplinary approach to determine the environmental and geomorphological impacts of the tailings spill. We have two specific objectives. (1) The physicochemical speciation and geochemical stability of spilled tailings will be characterised in surface and hyporheic sediments using bulk chemistry, mineralogical (XRD and SEM) and speciation methods (sequential extractions, electron microprobe analysis, XAS

  18. The Wireless Sensor Network (WSN) Based Coal Ash Impoundments Safety Monitoring System

    NASA Astrophysics Data System (ADS)

    Sun, E. J.; Nieto, A.; Zhang, X. K.

    2017-01-01

    Coal ash impoundments are inevitable production of the coal-fired power plants. All coal ash impoundments in North Carolina USA that tested for groundwater contamination are leaking toxic heavy metals and other pollutants. Coal ash impoundments are toxic sources of dangerous pollutants that pose a danger to human and environmental health if the toxins spread to adjacent surface waters and drinking water wells. Coal ash impoundments failures accidents resulted in serious water contamination along with toxic heavy metals. To improve the design and stability of coal ash impoundments, the Development of a Coal Ash Impoundment Safety Monitoring System (CAISM) was proposed based on the implementation of a wireless sensor network (WSN) with the ability to monitor the stability of coal ash impoundments, water level, and saturation levels on-demand and remotely. The monitoring system based on a robust Ad-hoc network could be adapted to different safety conditions.

  19. Physicochemical and mineralogical characterization of Musina mine copper and New Union gold mine tailings: Implications for fabrication of beneficial geopolymeric construction materials

    NASA Astrophysics Data System (ADS)

    Gitari, M. W.; Akinyemi, S. A.; Thobakgale, R.; Ngoejana, P. C.; Ramugondo, L.; Matidza, M.; Mhlongo, S. E.; Dacosta, F. A.; Nemapate, N.

    2018-01-01

    The mining industries in South Africa generates huge amounts of mine waste that includes tailings; waste rocks and spoils. The tailings materials are dumped in surface impoundments that turn to be sources of hazards to the environment and the surrounding communities. The main environmental hazards posed by these tailings facilities are associated with their chemical constituents. Exposure to chemical constituents can occur through windblown dust, erosion to surface water bodies, inhalation by human beings and animals and through bioaccumulation and bio magnification by plants. Numerous un-rehabilitated tailings dumps exist in Limpopo province of South Africa. The communities found around these mines are constantly exposed to the environmental hazards posed by these tailing facilities. Development of a cost-effective technology that can beneficially utilize these tailings can reduce the environmental hazards and benefit the communities. This paper presents the initial evaluation of the copper and gold mine tailings in Limpopo, South Africa with a view to assessing the suitability of conversion into beneficial geopolymeric materials. Copper tailings leachates had alkaline pH (7.34-8.49) while the gold tailings had acidic pH. XRD confirmed presence of aluminosilicate minerals. Geochemical fractionation indicates that majority of the major and trace species are present in residual fraction. A significant amount of Ca, Cu and K was available in the mobile fraction and is expected to be released on tailings contacting aqueous solutions. Results from XRF indicates the tailings are rich in SiO2, Al2O3 and CaO which are the main ingredients in geopolymerization process. The SiO2/Al2O3 ratios indicates the tailings would require blending with Al2O3 rich feedstock for them to develop maximum strength. Moreover, the tailings have particle size in the range of fine sand which indicates potential application as aggregates in conventional brick manufacture.

  20. Hydrologic effects of impoundments in Sherburne National Wildlife Refuge, Minnesota

    USGS Publications Warehouse

    Brown, R.G.

    1984-01-01

    The hydrologic effects of proposed impoundments in Sherburne National Wildlife Refuge were found to be insignificant with respect to both ground- and surface-water flow patterns and water quality. Monitoring of water levels in 23 observation wells and of discharge in the St. Francis River during 1980 and 1981 has shown that ground water in the surf icial aquifer responds quickly to areal recharge and subsequently discharges to the St. Francis River. The impoundment of surface water in the refuge was not found to affect water levels in the refuge significantly. The impoundments may affect ground-water-flow systems beneath and adjacent to the impoundments. Quality of ground and surface water was found to be similar except ground water contained higher concentrations of dissolved nitrite plus nitrate nitrogen than surface water. Phytoplankton removed dissolved nitrite plus nitrate nitrogen from surface water. The effects of impoundments on water quality are expected to be minor.

  1. Vehicle impoundment regulations as a means for reducing traffic-violations and road accidents in Israel.

    PubMed

    Rosenbloom, Tova; Eldror, Ehud

    2013-01-01

    The vehicle impoundment sanction in Israel is applicable to several violations, and authorizes police officers to impound a vehicle for period of 30 days, in addition to license suspension. This study examined the effects of vehicle impoundment on traffic-violations and road accidents in Israel, using both subjective and objective measures. A telephone survey was administered to 378 impounded drivers, examining their knowledge and support of the impoundment penalty, as well as the impoundment's effect on their daily life and subsequent driving behaviors. Survey results indicated most impounded drivers did not recognize the violations to which impoundment applies. Respondents described the impoundment experience as one, which interfered with a variety of daily life aspects, and eventually lead them to the adoption of safer driving behaviors. Additionally, data analysis of police records was performed on 1549 impounded drivers and 1354 controls with matching violations performed prior to the application of the impoundment regulation, comparing accident and traffic-violations involvement in the subsequent year. Results indicated that impoundment failed to yield a significant effect over subsequent accident involvement, compared to previous sanctions. A comparison of subsequent traffic-violations indicated lower rates of violations following impoundment as compared with previous sanctions. Specifically, drivers whose vehicle was impounded were less likely to commit traffic violations in the following year than drivers subjected to other sanctions. The results are explained according to psychological behavioral theories of punishment effectiveness. These findings provide further support for impoundment as a deterrent for several traffic-violations. Copyright © 2012 Elsevier Ltd. All rights reserved.

  2. Greening Solutions Applicable in the Tailing Ponds Tăusani and Bosneag from Moldova Nouă

    NASA Astrophysics Data System (ADS)

    Burlacu, I. F.; Deak, G.; Raischi, M. C.; Daescu, A.; Zamfir, S.; Uritescu, B.; Cirstinoiu, C.; Olteanu, M. V.

    2017-06-01

    This study aims to propose solutions for greening of the tailings ponds resulted from mining activities with transboundary impacts. As case study, are proposed for greening the Boşneag and Tăuşani tailing ponds because they pollute Moldova Nouă, Danube and towns on the Serbian side of the Danube with particles in suspension. We analyzed four scenarios of modeling dispersion of particles in suspension (copper and other heavy metals) from the Tăuşani and Boşneag tailing ponds in the theoretical background where pollution has cross-border nature and require studying the transport of pollutants over a long distance from the source and modeling dispersion of particles in suspension in the atmosphere, these were performed using TAPM model, able to simulate the aspects mentioned. After running the software for modeling the dispersion of particles, was revealed that the pollution generated from the pollution sources taked into consideration is very high and significantly affects quality of life on considerable areas both in Romania and Serbia, thus amplifying the need to implement greening solutions of the analyzed area. Following the results obtained are presented three alternatives solutions for greening the area studied, aiming at minimizing the impact on the environmental and population.

  3. 40 CFR 63.134 - Process wastewater provisions-surface impoundments.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 9 2010-07-01 2010-07-01 false Process wastewater provisions-surface... Manufacturing Industry for Process Vents, Storage Vessels, Transfer Operations, and Wastewater § 63.134 Process wastewater provisions—surface impoundments. (a) For each surface impoundment that receives, manages, or...

  4. Simulation of windblown dust transport from a mine tailings impoundment using a computational fluid dynamics model

    NASA Astrophysics Data System (ADS)

    Stovern, Michael; Felix, Omar; Csavina, Janae; Rine, Kyle P.; Russell, MacKenzie R.; Jones, Robert M.; King, Matt; Betterton, Eric A.; Sáez, A. Eduardo

    2014-09-01

    Mining operations are potential sources of airborne particulate metal and metalloid contaminants through both direct smelter emissions and wind erosion of mine tailings. The warmer, drier conditions predicted for the Southwestern US by climate models may make contaminated atmospheric dust and aerosols increasingly important, due to potential deleterious effects on human health and ecology. Dust emissions and dispersion of dust and aerosol from the Iron King Mine tailings in Dewey-Humboldt, Arizona, a Superfund site, are currently being investigated through in situ field measurements and computational fluid dynamics modeling. These tailings are heavily contaminated with lead and arsenic. Using a computational fluid dynamics model, we model dust transport from the mine tailings to the surrounding region. The model includes gaseous plume dispersion to simulate the transport of the fine aerosols, while individual particle transport is used to track the trajectories of larger particles and to monitor their deposition locations. In order to improve the accuracy of the dust transport simulations, both regional topographical features and local weather patterns have been incorporated into the model simulations. Results show that local topography and wind velocity profiles are the major factors that control deposition.

  5. Simulation of windblown dust transport from a mine tailings impoundment using a computational fluid dynamics model.

    PubMed

    Stovern, Michael; Felix, Omar; Csavina, Janae; Rine, Kyle P; Russell, MacKenzie R; Jones, Robert M; King, Matt; Betterton, Eric A; Sáez, A Eduardo

    2014-09-01

    Mining operations are potential sources of airborne particulate metal and metalloid contaminants through both direct smelter emissions and wind erosion of mine tailings. The warmer, drier conditions predicted for the Southwestern US by climate models may make contaminated atmospheric dust and aerosols increasingly important, due to potential deleterious effects on human health and ecology. Dust emissions and dispersion of dust and aerosol from the Iron King Mine tailings in Dewey-Humboldt, Arizona, a Superfund site, are currently being investigated through in situ field measurements and computational fluid dynamics modeling. These tailings are heavily contaminated with lead and arsenic. Using a computational fluid dynamics model, we model dust transport from the mine tailings to the surrounding region. The model includes gaseous plume dispersion to simulate the transport of the fine aerosols, while individual particle transport is used to track the trajectories of larger particles and to monitor their deposition locations. In order to improve the accuracy of the dust transport simulations, both regional topographical features and local weather patterns have been incorporated into the model simulations. Results show that local topography and wind velocity profiles are the major factors that control deposition.

  6. Simulation of windblown dust transport from a mine tailings impoundment using a computational fluid dynamics model

    PubMed Central

    Stovern, Michael; Felix, Omar; Csavina, Janae; Rine, Kyle P.; Russell, MacKenzie R.; Jones, Robert M.; King, Matt; Betterton, Eric A.; Sáez, A. Eduardo

    2014-01-01

    Mining operations are potential sources of airborne particulate metal and metalloid contaminants through both direct smelter emissions and wind erosion of mine tailings. The warmer, drier conditions predicted for the Southwestern US by climate models may make contaminated atmospheric dust and aerosols increasingly important, due to potential deleterious effects on human health and ecology. Dust emissions and dispersion of dust and aerosol from the Iron King Mine tailings in Dewey-Humboldt, Arizona, a Superfund site, are currently being investigated through in situ field measurements and computational fluid dynamics modeling. These tailings are heavily contaminated with lead and arsenic. Using a computational fluid dynamics model, we model dust transport from the mine tailings to the surrounding region. The model includes gaseous plume dispersion to simulate the transport of the fine aerosols, while individual particle transport is used to track the trajectories of larger particles and to monitor their deposition locations. In order to improve the accuracy of the dust transport simulations, both regional topographical features and local weather patterns have been incorporated into the model simulations. Results show that local topography and wind velocity profiles are the major factors that control deposition. PMID:25621085

  7. Creating and managing wetland impoundments to provide habitat for aquatic birds

    USGS Publications Warehouse

    Perry, M.C.; Kangas, P.; Obrecht, H.H.; Comin, Francisco A.; Herrera-Silveira, Jorge A.; Ramirez-Ramirez, Javier

    2000-01-01

    Patuxent Research Refuge, located in Central Maryland (USA), has approximately 140 ha of impoundments that were constructed for recreational and wildlife conservation purposes. Impoundments are of three major designs: dammed ravines, excavated basins, and diked ponds. Over 50 species of wetland plants were transplanted to impoundments of Patuxent from many parts of the United States between 1945 and 1963 to determine the species best suited for establishment in tannin-stained infertile waters. The wood duck was the only waterfowl species commonly observed on the Refuge when the area was established, but Canada geese, mallards, and black ducks, were introduced and numerous techniques developed to improve nesting and brood habitat. Twenty-six waterfowl species and 80 species of other water birds have used the impoundments for resting, feeding, or nesting. Management is now conducted to optimize avian biodiversity. Management techniques include drawdowns of water every 3-5 years in most impoundments to provide maximum plant and invertebrate food resources for wildlife. Research on the impounded wetlands at Patuxent has included evaluation of vegetation in regard to water level management, improving nest box design to reduce use of boxes by starlings, imprinting of waterfowl to elevated nesting structures to reduce predation on nests, and drawdown techniques to increase macroinvertebrates. Data on waterfowl abundance are evaluated relative to management activities and a preliminary computer model for management of the impoundments has been developed. Past, present, and future management and research projects are reviewed in this paper.

  8. 32 CFR 634.53 - Disposition of vehicles after impoundment.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 32 National Defense 4 2010-07-01 2010-07-01 true Disposition of vehicles after impoundment. 634.53 Section 634.53 National Defense Department of Defense (Continued) DEPARTMENT OF THE ARMY (CONTINUED) LAW ENFORCEMENT AND CRIMINAL INVESTIGATIONS MOTOR VEHICLE TRAFFIC SUPERVISION Impounding Privately Owned Vehicles § 634.53 Disposition of vehicles...

  9. Arsenic mobility in soils impacted by tailings at Zimapán, México

    NASA Astrophysics Data System (ADS)

    Aurora Armienta, M.; Resendiz, Isabel; Múgica, Violeta; Cruz, Olivia; Aguayo, Alejandra; Ceniceros, Nora

    2014-05-01

    The Zimapán mining zone, in Central México is one of the worldwide sites known for As contamination. For more than 20 years and until recently, As-rich groundwater, mainly due to mineralization in a limestone aquifer, was an important source of As exposure to the inhabitants. In addition, decades of ore processing have produced hazardous wastes (tailings), many of them settled in the town outskirts. Although mineralogical and chemical differences exist among the various deposits; every one has high As contents (up to several thousands mg/kg) and other toxic elements that may be released to the nearby soils. To assess As mobility in soils impacted by tailings, total and sequential fractionation determinations were performed in 120 superficial and 40 cm depth samples collected at various distances near three of the impoundments. Higher total As concentrations were measured in the dry (up to 51,534 mg/kg) with respect to the rainy season (up to 23,570 mg/kg) indicating the occurrence of As wash off by rain. Although concentrations were lower in the deep regarding the superficial samples at most sites, As contents reached several thousands mg/kg at 40 cm depth indicating also its vertical transport that may reach the shallow aquifer. Sequential extractions showed differences between soils impacted by highly oxidized (red) tailings and low oxidized (gray) deposits. Most of the As occurs in the Fe-Mn oxides fraction (up to 92%) followed by the organic matter and sulfides fraction (up to 52 %) in soils close to red tailings, while organic matter and sulfide fraction contain most of the As (up to 95%) in soil samples close to low-oxidized deposits. Arsenic proportion in the residual fraction increased with distance from oxidized tailings. Low pH values (from 2.0 to 2.5) in superficial soils revealed the influence of acid mine drainage at distances up to 40 m from the red deposit. In contrast, the lowest pH was 7.1 in soils impacted by low-oxidized deposits, reflecting

  10. Wind erosion of waste impoundments in arid climates and mitigation of dust pollution.

    PubMed

    Blight, G E

    2008-12-01

    Wind can erode and disperse fine-grained material from an impoundment of mining, industrial or municipal waste that stands above the level of its surroundings. Such dust dispersion can be a serious nuisance as well as a health hazard to inhabitants and animals in nearby settlements. It can also degrade crops, making them less marketable, and pollute soil, surface water and ground water. Wind can seasonally erode waste impoundments in all types of climate, but the erosion intensifies and persists for more of each year as regional aridity increases. As clouds of dust are often observed billowing across the top surfaces of waste impoundments in dry windy weather, there is a common misconception that dust arises from erosion of the top surface of an impoundment, resulting in much effort and money being misspent on top treatments when in fact the sloped sides of the impoundments are the true source of blown dust. This paper offers a brief review of general waste impoundment wind erosion issues and then focuses in more detail on the mechanics of how wind erodes surfaces of waste impoundments. Recommendations are offered for mitigating the effects of wind-eroded dust.

  11. Efficient degradation of Acid Orange 7 in aqueous solution by iron ore tailing Fenton-like process.

    PubMed

    Zheng, Jianming; Gao, Zhanqi; He, Huan; Yang, Shaogui; Sun, Cheng

    2016-05-01

    An effective method based on iron ore tailing Fenton-like process was studied for removing an azo dye, Acid Orange 7 (AO7) in aqueous solution. Five tailings were characterized by X-ray fluorescence spectroscope (XFS), Brunner-Emmet-Teller (BET) measurement, and Scanning Electron Microscope (SEM). The result of XFS showed that Fe, Si and Ca were the most abundant elements and some toxic heavy metals were also present in the studied tailings. The result of BET analysis indicated that the studied tailings had very low surface areas (0.64-5.68 m(2) g(-1)). The degradation efficiencies of AO7 were positively correlated with the content of iron oxide and cupric oxide, and not related with the BET surface area of the tailings. The co-existing metal elements, particularly Cu, might accelerate the heterogeneous Fenton-like reaction. The effects of other parameters on heterogeneous Fenton-like degradation of AO7 by a converter slag iron tailing (tailing E) which contains highest iron oxide were also investigated. The tailing could be reused 10 times without significant decrease of the catalytic capacity. Very low amount of iron species and almost undetectable toxic elements were leached in the catalytic degradation of AO7 by the tailing E. The reaction products were identified by gas chromatography-mass spectrometry and a possible pathway of AO7 degradation was proposed. This study not only provides an effective method for removing azo dyes in polluted water by employing waste tailings as Fenton-like catalysts, but also uses waste tailings as the secondary resource. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Microbial communities in flowback water impoundments from hydraulic fracturing for recovery of shale gas

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Mohan, Arvind Murali; Hartsock, Angela; Hammack, Richard W

    2013-12-01

    Hydraulic fracturing for natural gas extraction from shale produces waste brine known as flowback that is impounded at the surface prior to reuse and/or disposal. During impoundment, microbial activity can alter the fate of metals including radionuclides, give rise to odorous compounds, and result in biocorrosion that complicates water and waste management and increases production costs. Here, we describe the microbial ecology at multiple depths of three flowback impoundments from the Marcellus shale that were managed differently. 16S rRNA gene clone libraries revealed that bacterial communities in the untreated and biocide-amended impoundments were depth dependent, diverse, and most similar tomore » species within the taxa [gamma]-proteobacteria, [alpha]-proteobacteria, δ-proteobacteria, Clostridia, Synergistetes, Thermotogae, Spirochetes, and Bacteroidetes. The bacterial community in the pretreated and aerated impoundment was uniform with depth, less diverse, and most similar to known iodide-oxidizing bacteria in the [alpha]-proteobacteria. Archaea were identified only in the untreated and biocide-amended impoundments and were affiliated to the Methanomicrobia class. This is the first study of microbial communities in flowback water impoundments from hydraulic fracturing. The findings expand our knowledge of microbial diversity of an emergent and unexplored environment and may guide the management of flowback impoundments.« less

  13. Biological productivity in small impoundments

    USDA-ARS?s Scientific Manuscript database

    Most ponds and small impoundments are built or used with a principal use in mind. That use may be recreational fishing, commercial aquaculture, waterfowl hunting, potable water storage, irrigation water supply, livestock watering, stormwater retention, landscaping, swimming, or others. In practice, ...

  14. Towards Sustainable Water Quality In Estuarine Impoundments: The Current State.

    NASA Astrophysics Data System (ADS)

    Wright, J.; Worrall, F.

    Several estuarine impoundment schemes have been built or are proposed in the UK and worldwide. The impounding of estuaries is currently a popular approach to urban regeneration in the UK. By creation of an aesthetically pleasing amenity impound- ment, including the drowning of "unsightly" tidal mud flats, it is hoped that prestige development will be encouraged in the estuarine area. Impounding fundamentally alters the dynamics of estuaries, with consequences in terms of sedimentation patterns and rates, and water quality. The SIMBA Project at- tempts to understand the controls on water quality in impoundments, with a view to- wards long term and sustainable high water quality through good barrage design and management practice. Detailed water quality surveys have been carried out on a total of 79 dates on the Tees, Tawe, Wansbeck and Blyth estuaries. Water quality parameters which have been determined are pH, Eh, dissolved oxygen (DO), biochemical oxygen demand (BOD), conductivity, transparency, suspended solids, alkalinity, temperature, nutri- ents (nitrate+nitrite, ammonium and orthophosphate), and a large range of dissolved metals. Statistical analyses are used to demonstrate the major controls on water qual- ity in impoundments. A distinction is made between total tidal exclusion (freshwater) systems, in which water quality is primarily influenced by external/catchment factors, and partial tidal exclusion systems, in which water quality is processed internally. This internal processing is due to density stratification creating compartments of saline wa- ter in contact with oxygen demanding sediments and isolated from the atmosphere, which leads to conditions of low DO and changes in redox conditions which may lead to release of metals and phosphate from the sediment.

  15. Run-of-River Impoundments Can Remain Unfilled While Transporting Gravel Bedload: Numerical Modeling Results

    NASA Astrophysics Data System (ADS)

    Pearson, A.; Pizzuto, J. E.

    2015-12-01

    Previous work at run-of-river (ROR) dams in northern Delaware has shown that bedload supplied to ROR impoundments can be transported over the dam when impoundments remain unfilled. Transport is facilitated by high levels of sand in the impoundment that lowers the critical shear stresses for particle entrainment, and an inversely sloping sediment ramp connecting the impoundment bed (where the water depth is typically equal to the dam height) with the top of the dam (Pearson and Pizzuto, in press). We demonstrate with one-dimensional bed material transport modeling that bed material can move through impoundments and that equilibrium transport (i.e., a balance between supply to and export from the impoundment, with a constant bed elevation) is possible even when the bed elevation is below the top of the dam. Based on our field work and previous HEC-RAS modeling, we assess bed material transport capacity at the base of the sediment ramp (and ignore detailed processes carrying sediment up and ramp and over the dam). The hydraulics at the base of the ramp are computed using a weir equation, providing estimates of water depth, velocity, and friction, based on the discharge and sediment grain size distribution of the impoundment. Bedload transport rates are computed using the Wilcock-Crowe equation, and changes in the impoundment's bed elevation are determined by sediment continuity. Our results indicate that impoundments pass the gravel supplied from upstream with deep pools when gravel supply rate is low, gravel grain sizes are relatively small, sand supply is high, and discharge is high. Conversely, impoundments will tend to fill their pools when gravel supply rate is high, gravel grain sizes are relatively large, sand supply is low, and discharge is low. The rate of bedload supplied to an impoundment is the primary control on how fast equilibrium transport is reached, with discharge having almost no influence on the timing of equilibrium.

  16. Assessing Resiliency in a Large Lake Receiving Mine Tailings Waste: Impacts of Major Environmental Disturbance.

    NASA Astrophysics Data System (ADS)

    Petticrew, Ellen; Owens, Philip; Albers, Sam

    2016-04-01

    On 4th August 2014, the tailings impoundment of the Mount Polley copper and gold mine in British Columbia failed. Material from the impoundment (surface area = 2.7 km2) flowed into nearby Polley Lake and Hazeltine Creek, before discharging into Quesnel Lake, a large (ca. 100 km long, >500 m deep), relatively pristine lake. Initial estimates suggest that approximately 25 Mm3 of tailings (water and solids) and eroded soils and surficial materials from Hazeltine Creek were delivered to Quesnel Lake, raising the lake by 7.7 cm. Much of this material was deposited at the bottom of Quesnel Lake but a plume of fine-grained sediment (D50 of ca. 1 μm) remained suspended in the water column. The impact of the distribution of this sediment was monitored over the next 15 months using water column profiling for temperature, conductivity, fluorescence and turbidity with depth. The plume movement was regulated by natural processes associated with the physical limnology of this large fjord lake, specifically, seiche events which transferred suspended particles both up-lake, against the flow regime, and down-lake into the Quesnel River. Samples of lake water and bottom sediment taken from the impacted area show elevated levels of total metals and other elements, which may have important ecosystem implications in this watershed. Indeed, the breach occurred at a time when a peak run of sockeye salmon were returning to their natal streams in the Quesnel basin. Zooplankton sampling for metals was initiated in fall 2014 to determine up take of metals into the food web. This poster describes the failure of the impoundment dam and presents results of sampling the aquatic environment over the first fifteen months of impact.

  17. Quality of water for livestock in man-made impoundments in the northern High Plains

    Treesearch

    Mark A. Rumble

    1985-01-01

    Twenty-seven water quality parameters were measured in coal surface mine impoundments, bentonite surface mine impoundments, and livestock ponds in the Northern High Plains. Most impoundments were safe for use as a source for livestock drinking water. Eight water quality parameters were different (a

  18. Microbial communities in flowback water impoundments from hydraulic fracturing for recovery of shale gas.

    PubMed

    Murali Mohan, Arvind; Hartsock, Angela; Hammack, Richard W; Vidic, Radisav D; Gregory, Kelvin B

    2013-12-01

    Hydraulic fracturing for natural gas extraction from shale produces waste brine known as flowback that is impounded at the surface prior to reuse and/or disposal. During impoundment, microbial activity can alter the fate of metals including radionuclides, give rise to odorous compounds, and result in biocorrosion that complicates water and waste management and increases production costs. Here, we describe the microbial ecology at multiple depths of three flowback impoundments from the Marcellus shale that were managed differently. 16S rRNA gene clone libraries revealed that bacterial communities in the untreated and biocide-amended impoundments were depth dependent, diverse, and most similar to species within the taxa γ-proteobacteria, α-proteobacteria, δ-proteobacteria, Clostridia, Synergistetes, Thermotogae, Spirochetes, and Bacteroidetes. The bacterial community in the pretreated and aerated impoundment was uniform with depth, less diverse, and most similar to known iodide-oxidizing bacteria in the α-proteobacteria. Archaea were identified only in the untreated and biocide-amended impoundments and were affiliated to the Methanomicrobia class. This is the first study of microbial communities in flowback water impoundments from hydraulic fracturing. The findings expand our knowledge of microbial diversity of an emergent and unexplored environment and may guide the management of flowback impoundments. © 2013 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

  19. Uranium mill tailings: nuclear waste and natural laboratory for geochemical and radioecological investigations

    USGS Publications Warehouse

    Landa, Edward R.

    2004-01-01

    Uranium mill tailings (UMT) are a high volume, low specific activity radioactive waste typically disposed in surface impoundments. This review focuses on research on UMT and related earth materials during the past decade relevant to the assessment of: (1) mineral hosts of radionuclides; (2) the use of soil analogs in predicting long-term fate of radionuclides; (3) microbial and diagenetic processes that may alter radionuclide mobility in the surficial environment; (4) waste-management technologies to limit radionuclide migration; and (5) the impact of UMT on biota.

  20. Distribution of aquifers, liquid-waste impoundments, and municipal water-supply sources, Massachusetts

    USGS Publications Warehouse

    Delaney, David F.; Maevsky, Anthony

    1980-01-01

    Impoundments of liquid waste are potential sources of ground-water contamination in Massachusetts. The map report, at a scale of 1 inch equals 4 miles, shows the idstribution of aquifers and the locations of municipal water-supply sources and known liquid-waste impoundments. Ground water, an important source of municipal water supply, is produced from shallow sand and gravel aquifers that are generally unconfined, less than 200 feet thick, and yield less than 2,000 gallons per minute to individual wells. These aquifers commonly occupy lowlands and stream valleys and are most extensive in eastern Massachusetts. Surface impoundments of liquid waste are commonly located over these aquifers. These impoundments may leak and allow waste to infiltrate underlying aquifers and alter their water quality. (USGS)

  1. 30 CFR 77.216-1 - Water, sediment or slurry impoundments and impounding structures; identification.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Water, sediment or slurry impoundments and... AND SURFACE WORK AREAS OF UNDERGROUND COAL MINES Surface Installations § 77.216-1 Water, sediment or..., operating, or controlling the structure, shall be located on or immediately adjacent to each water, sediment...

  2. 30 CFR 77.216-1 - Water, sediment or slurry impoundments and impounding structures; identification.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Water, sediment or slurry impoundments and... AND SURFACE WORK AREAS OF UNDERGROUND COAL MINES Surface Installations § 77.216-1 Water, sediment or..., operating, or controlling the structure, shall be located on or immediately adjacent to each water, sediment...

  3. The Role of Small Impoundments on Flow Alteration Within River Networks

    NASA Astrophysics Data System (ADS)

    Brogan, C. O.; Keys, T.; Scott, D.; Burgholzer, R.; Kleiner, J.

    2017-12-01

    Numerous water quality and quantity models have been established to illustrate the ecologic and hydrologic effects of large reservoirs. Smaller, unregulated ponds are often assumed to have a negligible impact on watershed flow regimes even though they overwhelmingly outnumber larger waterbodies. Individually, these small impoundments impart merely a fraction of the flow alteration larger reservoirs do; however, a network of ponds may act cumulatively to alter the flow regime. Many models have attempted to study smaller impoundments but rely on selectively available rating curves or bathymetry surveys. This study created a generalized process to model impoundments of varying size across a 58 square mile watershed exclusively using satellite imagery and publicly available information as inputs. With information drawn from public Army Corps of Engineers databases and LiDAR surveys, it was found that impoundment surface and drainage area served as useful explanatory variables, capable of predicting both pond bathymetry and outlet structure area across the 37 waterbodies modeled within the study area. Working within a flow routing model with inputs from the Chesapeake Bay HSPF model and verified with USGS gauge data, flow simulations were conducted with increasing number of impoundments to quantify how small ponds affect the overall flow regime. As the total impounded volume increased, simulations showed a notable reduction in both low and peak flows. Medium-sized floods increased as the network of ponds and reservoirs stabilized the catchment's streamflow. The results of this study illustrate the importance of including ponded waters into river corridor models to improve downstream management of both water quantity and quality.

  4. The global abundance and size distribution of lakes, ponds, and impoundments

    USGS Publications Warehouse

    Downing, J.A.; Prairie, Y.T.; Cole, J.J.; Duarte, C.M.; Tranvik, L.J.; Striegl, Robert G.; McDowell, W.H.; Kortelainen, Pirkko; Caraco, N.F.; Melack, J.M.; Middelburg, J.J.

    2006-01-01

    One of the major impediments to the integration of lentic ecosystems into global environmental analyses has been fragmentary data on the extent and size distribution of lakes, ponds, and impoundments. We use new data sources, enhanced spatial resolution, and new analytical approaches to provide new estimates of the global abundance of surface-water bodies. A global model based on the Pareto distribution shows that the global extent of natural lakes is twice as large as previously known (304 million lakes; 4.2 million km 2 in area) and is dominated in area by millions of water bodies smaller than 1 km2. Similar analyses of impoundments based on inventories of large, engineered dams show that impounded waters cover approximately 0.26 million km2. However, construction of low-tech farm impoundments is estimated to be between 0.1 % and 6% of farm area worldwide, dependent upon precipitation, and represents >77,000 km 2 globally, at present. Overall, about 4.6 million km2 of the earth's continental "land" surface (>3%) is covered by water. These analyses underscore the importance of explicitly considering lakes, ponds, and impoundments, especially small ones, in global analyses of rates and processes. ?? 2006, by the American Society of Limnology and Oceanography, Inc.

  5. French Modular Impoundment: Final Cost and Performance Evaluation

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Drown, Peter; French, Bill

    This report comprises the Final Cost and Performance Report for the Department of Energy Award # EE0007244, the French Modular Impoundment (aka the “French Dam”.) The French Dam is a system of applying precast modular construction to water control structures. The “French Dam” is a term used to cover the construction means/methods used to construct or rehabilitate dams, diversion structures, powerhouses, and other hydraulic structures which impound water and are covered under FDE’s existing IP (Patents # US8414223B2; US9103084B2.)

  6. Tidal management sffects sub-adult fish assemblages in impounded South Carolina Marshes

    USGS Publications Warehouse

    Carswell, Ben L.; Peterson, James T.; Jennings, Cecil A.

    2015-01-01

    In coastal South Carolina, most impounded marshes are managed for waterfowl; fewer are managed for fishes. Tidal control is central to each strategy but raises concerns that nursery function could be impaired. This research examined the assemblage composition of fishes during early-life stages. We sampled two impoundments of each management type monthly in 2008 and 2009. We used light traps to collect 61,527 sub-adult fish representing 21 species and 16 families and push nets to collect 12,670 sub-adult fish representing 13 species and 11 families. The effective number of species detected at larval stage in “fish” impoundments (summer mean = 2.52 ± 0.20, winter mean = 2.02 ± 0.66) was greater than in “waterfowl” impoundments (summer mean = 1.27 ± 0.14, winter mean = 1.06 ± 0.09); CI = 90 %. Species richness did not differ between management types, but hierarchical linear models predicted differences in assemblage composition. These findings underscore the importance of frequent water exchange for maintaining diverse assemblages of early-life-stage fishes in marsh impoundments.

  7. Measures of Water Quality in Merrit Island National Wildlife Refuge Impoundments and Adjacent Indian River Lagoon

    NASA Technical Reports Server (NTRS)

    Blum, Linda K.

    2000-01-01

    The goal of this project was to conduct preliminary investigations to determine appropriate sampling strategies to measure the flux of dissolved nutrients (specifically, NH4+, NO3-, NO2-, and PO4(3-)) and suspended particulate matter (TSS) between impoundments and the IRL in preparation for an intensive three-year monitoring program. In addition to nutrients and TSS, a variety of common water quality indicators were also measured during these preliminary studies. Six impoundments and a single restored marsh were selected for study. Over a month long period, water samples were collected weekly at selected impoundment culverts. Water was collected in duplicate as independent grab samples from both the lagoon side and within the perimeter ditch directly adjacent to the culverts. Water quality indicators inside and outside the marsh impoundments were different. Ammonium, salinity, bacteria, and chlorophyll-a were higher inside the impoundments as expected possibly as a result of the great affect of evaporation on impoundment water. Water quality indicators responded rapidly both inside and outside the impoundments as exemplified by the increase in NH4(+)-N concentrations during a horseshoe crab die-off. Water quality indicators were high variable during the month in which water samples were collected. Because the impoundments are widely spaced it is logistically unrealistic to sample each of the impoundments and associated seagrass beds on a single day, sampling must be stratified to allow patterns of material movement and the annual flux of materials to and from the impoundments to be determined.

  8. Sedimentation in Lake Onalaska, Navigation Pool 7, upper Mississippi River, since impoundment

    USGS Publications Warehouse

    Korschgen, C.E.; Jackson, G.A.; Muessig, L.F.; Southworth, D.C.

    1987-01-01

    Sediment accumulation was evaluated in Lake Onalaska, a 2800-ha backwater impoundment on the Upper Mississippi River. Computer programs were used to process fathometric charts and generate an extensive data set on water depth for the lake. Comparison of 1983 survey data with pre-impoundment (before 1937) data showed that Lake Onalaska had lost less than 10 percent of its original mean depth in the 46 years since impoundment. Previous estimates of sedimentation rates based on Cesium-137 sediment core analysis appear to have been too high. (DBO)

  9. The 27 May 1937 catastrophic flow failure of gold tailings at Tlalpujahua, Michoacán, México

    NASA Astrophysics Data System (ADS)

    Macías, J. L.; Corona-Chávez, P.; Sanchéz-Núñez, J. M.; Martínez-Medina, M.; Garduño-Monroy, V. H.; García-Tenorio, F.; Cisneros-Máximo, G.

    2014-08-01

    On 27 May 1937, after one week of sustained heavy rainfall, a voluminous flood caused the death of at least 300 people and the destruction of the historic El Carmen church and several neighborhoods in the mining region of Tlalpujahua, Michoacán, central Mexico. This destructive flood was triggered by the breaching of the impoundment of the Los Cedros tailings and the sudden release of 16 Mt of water-saturated waste materials. The muddy silty flood, moving at estimated speeds of 20-25 m s-1, was channelized along the Dos Estrellas and Tlalpujahua drainages and devastated everything along its flow path. After advancing 2.5 km downstream, the flood slammed into El Carmen church and surrounding houses at estimated speeds of ~7 m s-1, destroying many of construction walls and covering the church floor with ~2 m of mud and debris. Eyewitness accounts and newspaper articles, together with analysis of archived photographic materials, indicated that the flood consisted of three muddy pulses. This interpretation is confirmed and extended by the results of our geological investigations during 2013 and 2014. Stratigraphic relations and granulometric data for selected proximal and distal samples show that the flood behaved as a hyperconcentrated flow along most of its trajectory. Even though premonitory signs of possible impoundment failure were reported days before the flood, and people living downstream were alerted, authorities ordered no evacuations or other mitigative actions. The catastrophic flood at Tlalpujahua provides a well-documented, though tragic, example of impoundment breaching of a tailings dam caused by the combined effects of intense rainfall, dam weakness, and inadequate emergency-management protocols - unfortunately an all too common case-scenario for most of the world's mining regions.

  10. The Authority of the President to Impound Funds Appropriated by Congress.

    ERIC Educational Resources Information Center

    Adams, James R.

    During fiscal year 1973, President Nixon ordered the impoundment of about 18 billion dollars in Federal funds for domestic programs. A large portion of that amount was used to slash federal funding for education programs. The entire impoundment controversy revolves around the doctrine of separation of powers. Insofar as the President has refused…

  11. Monticello Mill Tailings Site, Operable Unit lll, Annual Groundwater Report, May 2015 Through April 2016

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Nguyen, Jason; Smith, Fred

    This report provides the annual analysis of water quality restoration progress, cumulative through April 2016, for Operable Unit (OU) III, surface water and groundwater, of the U.S. Department of Energy (DOE) Office of Legacy Management (LM) Monticello Mill Tailings Site (MMTS). The MMTS is a Comprehensive Environmental Response, Compensation, and Liability Act National Priorities List site located in and near the city of Monticello, San Juan County, Utah. MMTS comprises the 110-acre site of a former uranium- and vanadium-ore-processing mill (mill site) and 1700 acres of surrounding private and municipal property. Milling operations generated 2.5 million cubic yards of wastemore » (tailings) from 1942 to 1960. The tailings were impounded at four locations on the mill site. Inorganic constituents in the tailings drained from the impoundments to contaminate local surface water (Montezuma Creek) and groundwater in the underlying alluvial aquifer. Mill tailings dispersed by wind and water also contaminated properties surrounding and downstream of the mill site. Remedial actions to remove and isolate radiologically contaminated soil, sediment, and debris from the former mill site, Operable Unit I (OU I), and surrounding properties (OU II) were completed in 1999 with the encapsulation of the wastes in an engineered repository located on DOE property 1 mile south of the former mill site. This effectively removed the primary source of groundwater contamination; however, contamination of groundwater and surface water remains within OU III at levels that exceed water quality protection standards. Uranium is the primary contaminant of concern (COC). LM implemented monitored natural attenuation with institutional controls as the OU III remedy in 2004. Because groundwater restoration proceeded more slowly than expected and did not meet performance criteria established in the OU III Record of Decision (June 2004), LM implemented a contingency action in 2009 by an Explanation

  12. The 27 May 1937 catastrophic flow failure of gold tailings at Tlalpujahua, Michoacan, Mexico

    NASA Astrophysics Data System (ADS)

    Macias, J. L.; Corona-Chavez, P.; Sanchez-Nunez, J. M.; Martinez-Medina, M.; Garduno-Monroy, V. H.; Capra, L.; Garcia-Tenorio, F.; Cisneros-Maximo, G.

    2015-05-01

    On 27 May 1937, after one week of sustained heavy rainfall, a voluminous flood caused the death of at least 300 people and the destruction of the historic El Carmen church and several neighborhoods in the mining region of Tlalpujahua, Michoacan, central Mexico. This destructive flood was triggered by the breaching of the impoundment of the Los Cedros tailings and the sudden release of circa 16 Mt of water-saturated waste materials. The muddy silty flood, moving at estimated speeds of 20-25 m s-1, was channelized along the Dos Estrellas and Tlalpujahua drainages and devastated everything along its flow path. After advancing 2.5 km downstream, the flood slammed into El Carmen church and surrounding houses at estimated speeds of ~ 7 m s-1, destroying many construction walls and covering the church floor with ~ 2 m of mud and debris. Revision of eyewitness accounts and newspaper articles, together with analysis of archived photographic materials, indicated that the flood consisted of three muddy pulses. Stratigraphic relations and granulometric data for selected proximal and distal samples show that the flood behaved as a hyperconcentrated flow along most of its trajectory. A total volume of the Lamas flood deposit was estimated as 1.5 x 106 m3. The physically based bidimensional (2-D) hydraulic model FLO-2D was implemented to reproduce the breached flow (0.5 sediment concentration) with a maximum flow discharge of 8000 m3 s-1 for a total outflow volume (sediment + water) of 2.5 x 106 m3, similar to the calculations obtained using field measurements. Even though premonitory signs of possible impoundment failure were reported days before the flood, and people living downstream were alerted, authorities ordered no evacuations or other mitigative actions. The catastrophic flood at Tlalpujahua provides a well-documented, though tragic, example of impoundment breaching of a tailings dam caused by the combined effects of intense rainfall, dam weakness, and inadequate

  13. 30 CFR 780.25 - Reclamation plan: Siltation structures, impoundments, and refuse piles.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... for each proposed siltation structure, impoundment, and refuse pile within the proposed permit area... is capable of being done after consideration of cost, logistics, and available technology. The fact... groundwater flow observed or anticipated during wet periods in the area of the proposed impoundment. (D...

  14. 30 CFR 784.16 - Reclamation plan: Siltation structures, impoundments, and refuse piles.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... for each proposed siltation structure, impoundment, and refuse pile within the proposed permit area... of being done after consideration of cost, logistics, and available technology. The fact that one... periods in the area of the proposed impoundment. (D) Consider the possibility of mudflows, rock-debris...

  15. 30 CFR 780.25 - Reclamation plan: Siltation structures, impoundments, and refuse piles.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... for each proposed siltation structure, impoundment, and refuse pile within the proposed permit area... is capable of being done after consideration of cost, logistics, and available technology. The fact... groundwater flow observed or anticipated during wet periods in the area of the proposed impoundment. (D...

  16. 30 CFR 784.16 - Reclamation plan: Siltation structures, impoundments, and refuse piles.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... for each proposed siltation structure, impoundment, and refuse pile within the proposed permit area... of being done after consideration of cost, logistics, and available technology. The fact that one... periods in the area of the proposed impoundment. (D) Consider the possibility of mudflows, rock-debris...

  17. 30 CFR 780.25 - Reclamation plan: Siltation structures, impoundments, and refuse piles.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... for each proposed siltation structure, impoundment, and refuse pile within the proposed permit area... is capable of being done after consideration of cost, logistics, and available technology. The fact... groundwater flow observed or anticipated during wet periods in the area of the proposed impoundment. (D...

  18. Speciation and characterization of arsenic in Ketza River mine tailings using X-ray absorption spectroscopy.

    PubMed

    Paktunc, Dogan; Foster, Andrea; Laflamme, Gilles

    2003-05-15

    Ketza River mine tailings deposited underwater and those exposed near the tailings impoundment contain approximately 4 wt % As. Column-leaching tests indicated the potential for high As releases from the tailings. The tailings are composed dominantly of iron oxyhydroxides, quartz, calcite, dolomite, muscovite, ferric arsenates, and calcium-iron arsenates. Arsenopyrite and pyrite are trace constituents. Chemical compositions of iron oxyhydroxide and arsenate minerals are highly variable. The XANES spectra indicate that arsenic occurs as As(V) in tailings, but air-drying prior to analysis may have oxidized lower-valent As. The EXAFS spectra indicate As-Fe distances of 3.35-3.36 A for the exposed tailings and 3.33-3.35 A for the saturated tailings with coordination numbers of 0.96-1.11 and 0.46-0.64, respectively. The As-Ca interatomic distances ranging from 4.15 to 4.18 A and the coordination numbers of 4.12-4.58 confirm the presence of calcium-iron arsenates in the tailings. These results suggest that ferric arsenates and inner-sphere corner sharing or bidentate-binuclear attachment of arsenate tetrahedra onto iron hydroxide octahedra are the dominant form of As in the tailings. EXAFS spectra indicate that the exposed tailings are richer in arsenate minerals whereas the saturated tailings are dominated by the iron oxyhydroxides, which could help explain the greater release of As from the exposed tailings during leaching tests. It is postulated that the dissolution of ferric arsenates during flow-through experiments caused the high As releases from both types of tailings. Arsenic tied to iron oxyhydroxides as adsorbed species are considered stable; however, iron oxyhydroxides having low Fe/As molar ratios may not be as stable. Continued As releases from the tailings are likely due to dissolution of both ferric and calcium-iron arsenates and desorption of As from high-As bearing iron oxyhydroxides during aging.

  19. Speciation and characterization of arsenic in Ketza River mine tailings using x-ray absorption spectroscopy

    USGS Publications Warehouse

    Paktunc, D.; Foster, A.; Laflamme, G.

    2003-01-01

    Ketza River mine tailings deposited underwater and those exposed near the tailings impoundment contain approximately 4 wt % As. Column-leaching tests indicated the potential for high As releases from the tailings. The tailings are composed dominantly of iron oxyhydroxides, quartz, calcite, dolomite, muscovite, ferric arsenates, and calcium-iron arsenates. Arsenopyrite and pyrite are trace constituents. Chemical compositions of iron oxyhydroxide and arsenate minerals are highly variable. The XANES spectra indicate that arsenic occurs as As(V) in tailings, but air-drying prior to analysis may have oxidized lower-valent As. The EXAFS spectra indicate As-Fe distances of 3.35-3.36 A?? for the exposed tailings and 3.33-3.35 A?? for the saturated tailings with coordination numbers of 0.96-1.11 and 0.46-0.64, respectively. The As-Ca interatomic distances ranging from 4.15 to 4.18 A?? and the coordination numbers of 4.12-4.58 confirm the presence of calcium-iron arsenates in the tailings. These results suggest that ferric arsenates and inner-sphere corner sharing or bidentatebinuclear attachment of arsenate tetrahedra onto iron hydroxide octahedra are the dominant form of As in the tailings. EXAFS spectra indicate that the exposed tailings are richer in arsenate minerals whereas the saturated tailings are dominated by the iron oxyhydroxides, which could help explain the greater release of As from the exposed tailings during leaching tests. It is postulated that the dissolution of ferric arsenates during flow-through experiments caused the high As releases from both types of tailings. Arsenic tied to iron oxyhydroxides as adsorbed species are considered stable; however, iron oxyhydroxides having low Fe/As molar ratios may not be as stable. Continued As releases from the tailings are likely due to dissolution of both ferric and calcium-iron arsenates and desorption of As from high-As bearing iron oxyhydroxides during aging.

  20. Sediment characteristics and configuration within three dam impoundments on the Kalamazoo River, Michigan, 2000

    USGS Publications Warehouse

    Rheaume, S.J.; Rachol, C.M.; Hubbell, D.L.; Simard, Andreanne

    2002-01-01

    The removal of the remnants of three hydroelectric dams on the Kalamazoo River near Plainwell, Otsego, and Allegan, Michigan, has been proposed. The benefits of this removal include returning the Kalamazoo River to its pre-dam flow, increasing recreational use and safety on the river, and improving aquatic habitat. The U.S. Environmental Protection Agency has designated this reach of the Kalamazoo River as a Federal Superfund site because of the historical discharge of papermill waste containing polychlorinated biphenyls. Much of this waste material remains concentrated in organic sediment and kaolinite clay deposited upstream from the three dam foundations. Sediment containing up to 150 milligrams per kilogram polychlorinated biphenyls could move if dam foundations are removed; therefore, it is necessary to estimate the characteristic and configuration of the sediment before work begins. Data collected from augered sections and sediment cores show that impoundment sediments were deposited in two distinctly different sedimentary environments. Interbedded lacustrine sediments that overlie the pre-dam channel surface consist of organic-rich silt and clay, fine to medium sand, and some gravel. These materials were deposited in a repetitive, cyclic fashion related to former stream velocities when the impoundment water levels were 5-10 feet higher. Lowering of these water levels and demolition of the superstructures of these dams resulted in erosion of much of these instream lacustrine sediments and subsequent deposition of coarse-grained alluvium in the impounded channel behind the remaining dam foundations. The composite thicknesses of the lacustrine deposits and overlying alluvium was determined from sediment cores collected from each impoundment. The volume of instream sediment contained in each impoundment is estimated to be about 77,600 cubic yards at the Plainwell impoundment; 268,900 cubic yards at the Otsego impoundment; and 1,192,600 cubic yards at the

  1. Efficiency of baited hoop nets for sampling catfish in southeastern U.S. small impoundments

    USGS Publications Warehouse

    Wallace, Benjamin C.; Weaver, Daniel M.; Kwak, Thomas J.

    2011-01-01

    Many U.S. natural resource agencies stock catfish (Ictaluridae) into small impoundments to provide recreational fishing opportunities. However, effective standardized methods for sampling catfish in small impoundments have not been developed for wide application, particularly in the southeastern United States. We evaluated the efficiency of three bait treatments (i.e., soybean cake, sunflower cake, and no bait) of tandem hoop nets in two North Carolina small impoundments during the fall of 2008 and spring of 2009 in a factorial experimental design. The impoundments were stocked with catchable-size channel catfish Ictalurus punctatus at contrastingly low (5.5 fi sh/ha) and high (90.0 fi sh/ha) rates prior to our sampling. Nets baited with soybean cake consistently sampled more channel catfish than any other treatment. Channel catfish catch ranged as high as 3,251 fi sh per net series during the fall in nets baited with soybean cake in the intensively stocked impoundment and was up to 8.5 and 15.3 times higher during the fall than in the spring in each impoundment. Nets baited with soybean cake sampled significantly (12 and 24 times) more channel catfish than those with no bait in the two impoundments. These trends did not occur among other catfish species. Nonictalurid fish and turtle catch was higher during spring compared to that of fall, corresponding with low channel catfish catches. Our results indicate that tandem hoop nets baited with soybean cake during the fall is a more efficient method for sampling channel catfish compared to nets baited with sunflower cake or no bait in spring or fall. Our findings validate this technique for application in southeastern U.S. small impoundments to assess catfish abundance to guide management and evaluate the success of catfish stocking programs.

  2. Cumulative impoundment evaporation in water resource management within the mid-Atlantic: A case study in Virginia

    NASA Astrophysics Data System (ADS)

    Scott, D.; Burgholzer, R.; Kleiner, J.; Brogan, C. O.; Julson, C.; Withers, E.

    2017-12-01

    Across the eastern United States, successful management of water resources to satisfy the competing demands for human consumption, industry, agriculture, and ecosystems requires both water quality and water quantity considerations. Over the last 2 decades, low streamflows during dry summers have increased scrutiny on water supply withdrawals. Within Virginia, a statewide hydrologic model provides quantitative assessments on impacts from proposed water withdrawals to downstream river flow. Currently, evaporative losses are only accounted for from the large reservoirs. In this study, we sought to provide a baseline estimate for the cumulative evaporation from impoundments across all of the major river basins in Virginia. Virginia provides an ideal case study for the competing water demands in the mid-Atlantic region given the unique tracking of water withdrawals throughout the river corridor. In the over 73,000 Virginia impoundments, the cumulative annual impoundment evaporation was 706 MGD, or 49% of the permitted water withdrawal. The largest reservoirs (>100 acres) represented over 400 MGD, and 136 MGD for the smaller impoundments (< 5 acres). In regions with high impoundment density, impoundment evaporation tended to be a significant fraction of the total amount of water loss (evaporation + demand), with some areas where impoundment evaporation was greater than human water demand. Seasonally, our results suggest that cumulative impoundment evaporation in some watersheds greatly impacts streamflow during low flow periods. Our results demonstrate that future water supply planning will require not only understanding evaporation within large reservoirs, but also the thousands of small impoundments across the landscape.

  3. Solvent extraction of Cu, Mo, V, and U from leach solutions of copper ore and flotation tailings.

    PubMed

    Smolinski, Tomasz; Wawszczak, Danuta; Deptula, Andrzej; Lada, Wieslawa; Olczak, Tadeusz; Rogowski, Marcin; Pyszynska, Marta; Chmielewski, Andrzej Grzegorz

    2017-01-01

    Flotation tailings from copper production are deposits of copper and other valuable metals, such as Mo, V and U. New hydrometallurgical technologies are more economical and open up new possibilities for metal recovery. This work presents results of the study on the extraction of copper by mixed extractant consisting p -toluidine dissolved in toluene. The possibility of simultaneous liquid-liquid extraction of molybdenum and vanadium was examined. D2EHPA solutions was used as extractant, and recovery of individual elements compared for the representative samples of ore and copper flotation tailings. Radiometric methods were applied for process optimization.

  4. Short-term microbial effects of a large-scale mine-tailing storage facility collapse on the local natural environment

    PubMed Central

    Baldwin, Susan A.; Taylor, Jon; Gurr, David B.; Denesiuk, Daniel R.; Van Hamme, Jonathan D.; Fraser, Lauchlan H.

    2018-01-01

    We investigated the impacts of the Mount Polley tailings impoundment failure on chemical, physical, and microbial properties of substrates within the affected watershed, comprised of 70 hectares of riparian wetlands and 40 km of stream and lake shore. We established a biomonitoring network in October of 2014, two months following the disturbance, and evaluated riparian and wetland substrates for microbial community composition and function via 16S and full metagenome sequencing. A total of 234 samples were collected from substrates at 3 depths and 1,650,752 sequences were recorded in a geodatabase framework. These data revealed a wealth of information regarding watershed-scale distribution of microbial community members, as well as community composition, structure, and response to disturbance. Substrates associated with the impact zone were distinct chemically as indicated by elevated pH, nitrate, and sulphate. The microbial community exhibited elevated metabolic capacity for selenate and sulfate reduction and an abundance of chemolithoautotrophs in the Thiobacillus thiophilus/T. denitrificans/T. thioparus clade that may contribute to nitrate attenuation within the affected watershed. The most impacted area (a 6 km stream connecting two lakes) exhibited 30% lower microbial diversity relative to the remaining sites. The tailings impoundment failure at Mount Polley Mine has provided a unique opportunity to evaluate functional and compositional diversity soon after a major catastrophic disturbance to assess metabolic potential for ecosystem recovery. PMID:29694379

  5. High levels of activity of bats at gold mining water bodies: implications for compliance with the International Cyanide Management Code.

    PubMed

    Griffiths, Stephen R; Donato, David B; Coulson, Graeme; Lumsden, Linda F

    2014-06-01

    Wildlife and livestock are known to visit and interact with tailings dam and other wastewater impoundments at gold mines. When cyanide concentrations within these water bodies exceed a critical toxicity threshold, significant cyanide-related mortality events can occur in wildlife. Highly mobile taxa such as birds are particularly susceptible to cyanide toxicosis. Nocturnally active bats have similar access to uncovered wastewater impoundments as birds; however, cyanide toxicosis risks to bats remain ambiguous. This study investigated activity of bats in the airspace above two water bodies at an Australian gold mine, to assess the extent to which bats use these water bodies and hence are at potential risk of exposure to cyanide. Bat activity was present on most nights sampled during the 16-month survey period, although it was highly variable across nights and months. Therefore, despite the artificial nature of wastewater impoundments at gold mines, these structures present attractive habitats to bats. As tailings slurry and supernatant pooling within the tailings dam were consistently well below the industry protective concentration limit of 50 mg/L weak acid dissociable (WAD) cyanide, wastewater solutions stored within the tailings dam posed a minimal risk of cyanide toxicosis for wildlife, including bats. This study showed that passively recorded bat echolocation call data provides evidence of the presence and relative activity of bats above water bodies at mine sites. Furthermore, echolocation buzz calls recorded in the airspace directly above water provide indirect evidence of foraging and/or drinking. Both echolocation monitoring and systematic sampling of cyanide concentration in open wastewater impoundments can be incorporated into a gold mine risk-assessment model in order to evaluate the risk of bat exposure to cyanide. In relation to risk minimisation management practices, the most effective mechanism for preventing cyanide toxicosis to wildlife

  6. Anthropogenic sediment retention: major global impact from registered river impoundments

    NASA Astrophysics Data System (ADS)

    Vörösmarty, Charles J.; Meybeck, Michel; Fekete, Balázs; Sharma, Keshav; Green, Pamela; Syvitski, James P. M.

    2003-10-01

    In this paper, we develop and apply a framework for estimating the potential global-scale impact of reservoir construction on riverine sediment transport to the ocean. Using this framework, we discern a large, global-scale, and growing impact from anthropogenic impoundment. Our study links information on 633 of the world's largest reservoirs (LRs) (≥0.5 km 3 maximum storage capacity) to the geography of continental discharge and uses statistical inferences to assess the potential impact of the remaining >44,000 smaller reservoirs (SRs). Information on the LRs was linked to a digitized river network at 30' (latitude×longitude) spatial resolution. A residence time change (Δ τR) for otherwise free-flowing river water is determined locally for each reservoir and used with a sediment retention function to predict the proportion of incident sediment flux trapped within each impoundment. The discharge-weighted mean Δ τR for individual impoundments distributed across the globe is 0.21 years for LRs and 0.011 years for SRs. More than 40% of global river discharge is intercepted locally by the LRs analyzed here, and a significant proportion (≈70%) of this discharge maintains a theoretical sediment trapping efficiency in excess of 50%. Half of all discharge entering LRs shows a local sediment trapping efficiency of 80% or more. Analysis of the recent history of river impoundment reveals that between 1950 and 1968, there was tripling from 5% to 15% in global LR sediment trapping, another doubling to 30% by 1985, and stabilization thereafter. Several large basins such as the Colorado and Nile show nearly complete trapping due to large reservoir construction and flow diversion. From the standpoint of sediment retention rates, the most heavily regulated drainage basins reside in Europe. North America, Africa, and Australia/Oceania are also strongly affected by LRs. Globally, greater than 50% of basin-scale sediment flux in regulated basins is potentially trapped in

  7. 25 CFR 166.807 - When will we impound unauthorized livestock or other property?

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... WATER GRAZING PERMITS Trespass Actions § 166.807 When will we impound unauthorized livestock or other... other property refuses to accept delivery of a written notice of trespass and the unauthorized livestock... after five days of providing notice of impoundment if you failed to correct the trespass. ...

  8. 25 CFR 166.807 - When will we impound unauthorized livestock or other property?

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... WATER GRAZING PERMITS Trespass Actions § 166.807 When will we impound unauthorized livestock or other... other property refuses to accept delivery of a written notice of trespass and the unauthorized livestock... after five days of providing notice of impoundment if you failed to correct the trespass. ...

  9. 25 CFR 166.807 - When will we impound unauthorized livestock or other property?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... WATER GRAZING PERMITS Trespass Actions § 166.807 When will we impound unauthorized livestock or other... other property refuses to accept delivery of a written notice of trespass and the unauthorized livestock... after five days of providing notice of impoundment if you failed to correct the trespass. ...

  10. 25 CFR 166.807 - When will we impound unauthorized livestock or other property?

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... WATER GRAZING PERMITS Trespass Actions § 166.807 When will we impound unauthorized livestock or other... other property refuses to accept delivery of a written notice of trespass and the unauthorized livestock... after five days of providing notice of impoundment if you failed to correct the trespass. ...

  11. 25 CFR 166.807 - When will we impound unauthorized livestock or other property?

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... WATER GRAZING PERMITS Trespass Actions § 166.807 When will we impound unauthorized livestock or other... other property refuses to accept delivery of a written notice of trespass and the unauthorized livestock... after five days of providing notice of impoundment if you failed to correct the trespass. ...

  12. Using Helicopter Electromagnetic Surveys to Identify Potential Hazards at Mine Waste Impoundments

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Hammack, R.W.

    2008-01-01

    In July 2003, helicopter electromagnetic surveys were conducted at 14 coal waste impoundments in southern West Virginia. The purpose of the surveys was to detect conditions that could lead to impoundment failure either by structural failure of the embankment or by the flooding of adjacent or underlying mine works. Specifically, the surveys attempted to: 1) identify saturated zones within the mine waste, 2) delineate filtrate flow paths through the embankment or into adjacent strata and receiving streams, and 3) identify flooded mine workings underlying or adjacent to the waste impoundment. Data from the helicopter surveys were processed to generate conductivity/depthmore » images. Conductivity/depth images were then spatially linked to georeferenced air photos or topographic maps for interpretation. Conductivity/depth images were found to provide a snapshot of the hydrologic conditions that exist within the impoundment. This information can be used to predict potential areas of failure within the embankment because of its ability to image the phreatic zone. Also, the electromagnetic survey can identify areas of unconsolidated slurry in the decant basin and beneath the embankment. Although shallow, flooded mineworks beneath the impoundment were identified by this survey, it cannot be assumed that electromagnetic surveys can detect all underlying mines. A preliminary evaluation of the data implies that helicopter electromagnetic surveys can provide a better understanding of the phreatic zone than the piezometer arrays that are typically used.« less

  13. Spawning activity of the Australian lungfish Neoceratodus forsteri in an impoundment.

    PubMed

    Roberts, D T; Mallett, S; Krück, N C; Loh, W; Tibbetts, I

    2014-01-01

    This study assessed the spawning activity of the threatened Australian lungfish Neoceratodus forsteri by measuring egg densities within the artificial habitat of a large impoundment (Lake Wivenhoe, Australia). Eggs were sampled (August to November 2009) from multiple locations across the impoundment, but occurred at highest densities in water shallower than 40 cm along shorelines with a dense cover of submerged terrestrial vegetation. The numbers of eggs declined over the study period and all samples were dominated by early developmental stages and high proportions of unviable eggs. The quality of the littoral spawning habitats declined over the study as flooded terrestrial grasses decomposed and filamentous algae coverage increased. Water temperatures at the spawning site exhibited extreme variations, ranging over 20·4° C in water shallower than 5 cm. Dissolved oxygen concentrations regularly declined to <1 mg l⁻¹ at 40 and 80 cm water depth. Spawning habitats utilised by N. forsteri within impoundments expose embryos to increased risk of desiccation or excessive submergence through water-level variations, and extremes in temperature and dissolved oxygen concentration that present numerous challenges for successful spawning and recruitment of N. forsteri in large impoundment environments. © 2014 The Fisheries Society of the British Isles.

  14. Low molecular weight carboxylic acids in oxidizing porphyry copper tailings.

    PubMed

    Dold, Bernhard; Blowes, David W; Dickhout, Ralph; Spangenberg, Jorge E; Pfeifer, Hans-Rudolf

    2005-04-15

    The distribution of low molecular weight carboxylic acids (LMWCA) was investigated in pore water profiles from two porphyry copper tailings impoundments in Chile (Piuquenes at La Andina and Cauquenes at El Teniente mine). The objectives of this study were (1) to determine the distribution of LMWCA, which are interpreted to be the metabolic byproducts of the autotroph microbial community in this low organic carbon system, and (2) to infer the potential role of these acids in cycling of Fe and other elements in the tailings impoundments. The speciation and mobility of iron, and potential for the release of H+ via hydrolysis of the ferric iron, are key factors in the formation of acid mine drainage in sulfidic mine wastes. In the low-pH oxidation zone of the Piuquenes tailings, Fe(III) is the dominant iron species and shows high mobility. LMWCA, which occur mainly between the oxidation front down to 300 cm below the tailings surface at both locations (e.g., max concentrations of 0.12 mmol/L formate, 0.17 mmol/L acetate, and 0.01 mmol/L pyruvate at Piuquenes and 0.14 mmol/L formate, 0.14 mmol/L acetate, and 0.006 mmol/L pyruvate at Cauquenes), are observed at the same location as high Fe concentrations (up to 71.2 mmol/L Fe(II) and 16.1 mmol/L Fe(III), respectively). In this zone, secondary Fe(III) hydroxides are depleted. Our data suggest that LMWCA may influence the mobility of iron in two ways. First, complexation of Fe(III), through formation of bidentate Fe(III)-LMWCA complexes (e.g., pyruvate, oxalate), may enhance the dissolution of Fe(III) (oxy)hydroxides or may prevent precipitation of Fe(III) (oxy)hydroxides. Soluble Fe(III) chelate complexes which may be mobilized downward and convert to Fe(II) by Fe(III) reducing bacteria. Second, monodentate LMWCA (e.g., acetate and formate) can be used by iron-reducing bacteria as electron donors (e.g., Acidophilum spp.), with ferric iron as the electron acceptor. These processes may, in part, explain the low abundances

  15. 25 CFR 161.707 - When will BIA impound unauthorized livestock or other property?

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... WATER NAVAJO PARTITIONED LANDS GRAZING PERMITS Trespass Actions § 161.707 When will BIA impound... livestock or other property refuses to accept delivery of a written notice of trespass and the unauthorized... after 5 days of providing notice of impoundment if the trespasser failed to correct the trespass. ...

  16. 25 CFR 161.707 - When will BIA impound unauthorized livestock or other property?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... WATER NAVAJO PARTITIONED LANDS GRAZING PERMITS Trespass Actions § 161.707 When will BIA impound... livestock or other property refuses to accept delivery of a written notice of trespass and the unauthorized... after 5 days of providing notice of impoundment if the trespasser failed to correct the trespass. ...

  17. 25 CFR 161.707 - When will BIA impound unauthorized livestock or other property?

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... WATER NAVAJO PARTITIONED LANDS GRAZING PERMITS Trespass Actions § 161.707 When will BIA impound... livestock or other property refuses to accept delivery of a written notice of trespass and the unauthorized... after 5 days of providing notice of impoundment if the trespasser failed to correct the trespass. ...

  18. 25 CFR 161.707 - When will BIA impound unauthorized livestock or other property?

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... WATER NAVAJO PARTITIONED LANDS GRAZING PERMITS Trespass Actions § 161.707 When will BIA impound... livestock or other property refuses to accept delivery of a written notice of trespass and the unauthorized... after 5 days of providing notice of impoundment if the trespasser failed to correct the trespass. ...

  19. 25 CFR 161.707 - When will BIA impound unauthorized livestock or other property?

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... WATER NAVAJO PARTITIONED LANDS GRAZING PERMITS Trespass Actions § 161.707 When will BIA impound... livestock or other property refuses to accept delivery of a written notice of trespass and the unauthorized... after 5 days of providing notice of impoundment if the trespasser failed to correct the trespass. ...

  20. Estimated sediment thickness, quality, and toxicity to benthic organisms in selected impoundments in Massachusetts

    USGS Publications Warehouse

    Breault, Robert F.; Sorenson, Jason R.; Weiskel, Peter K.

    2013-01-01

    The U.S. Geological Survey and the Massachusetts Department of Fish and Game, Division of Ecological Restoration, collaborated to collect baseline information on the quantity and quality of sediment impounded behind selected dams in Massachusetts, including sediment thickness and the occurrence of contaminants potentially toxic to benthic organisms. The thicknesses of impounded sediments were measured, and cores of sediment were collected from 32 impoundments in 2004 and 2005. Cores were chemically analyzed, and concentrations of 32 inorganic elements and 108 organic compounds were quantified. Sediment thicknesses varied considerably among the 32 impoundments, with an average thickness of 3.7 feet. Estimated volumes also varied greatly, ranging from 100,000 cubic feet to 81 million cubic feet. Concentrations of toxic contaminants as well as the number of contaminants detected above analytical quantification levels (also known as laboratory reporting levels) varied greatly among sampling locations. Based on measured contaminant concentrations and comparison to published screening thresholds, bottom sediments were predicted to be toxic to bottom-dwelling (benthic) organisms in slightly under 30 percent of the impoundments sampled. Statistically significant relations were found between several of the contaminants and individual indicators of urban land use and industrial activity in the upstream drainage areas of the impoundments. However, models developed to estimate contaminant concentrations at unsampled sites from upstream landscape characteristics had low predictive power, consistent with the long and complex land-use history that is typical of many drainage areas in Massachusetts.

  1. 40 CFR 61.344 - Standards: Surface impoundments.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 9 2012-07-01 2012-07-01 false Standards: Surface impoundments. 61.344 Section 61.344 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS National Emission Standard for Benzene...

  2. 40 CFR 61.344 - Standards: Surface impoundments.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 8 2010-07-01 2010-07-01 false Standards: Surface impoundments. 61.344 Section 61.344 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS National Emission Standard for Benzene...

  3. Study Effects of Impounded Water on Trees

    Treesearch

    W. M. Broadfoot

    1970-01-01

    In recent years farmers and sportsmen have built many temporary shallow-water impoundments in southern hardwood forests. While the main purpose has been to attract waterfowl, a recent study shows that these forest lakes, if properly managed, can also benefit the timber.

  4. Pre- and post-impoundment nitrogen in the lower Missouri River

    USGS Publications Warehouse

    Blevins, Dale W.; Wilkison, Donald H.; Niesen, Shelley L.

    2013-01-01

    Large water-sample sets collected from 1899 through 1902, 1907, and in the early 1950s allow comparisons of pre-impoundment and post-impoundment (1969 through 2008) nitrogen concentrations in the lower Missouri River. Although urban wastes were not large enough to detectably increase annual loads of total nitrogen at the beginning of the 20th century, carcass waste, stock-yard manure, and untreated human wastes measurably increased ammonia and organic-nitrogen concentrations during low flows. Average total-nitrogen concentrations in both periods were about 2.5 mg/l, but much of the particulate-organic nitrogen, which was the dominant form of nitrogen around 1900, has been replaced by nitrate. This change in speciation was caused by the nearly 80% decrease in suspended-sediment concentrations that occurred after impoundment, modern agriculture, drainage of riparian wetlands, and sewage treatment. Nevertheless, bioavailable nitrogen has not been low enough to limit primary production in the Missouri River since the beginning of the 20th century. Nitrate concentrations have increased more rapidly from 2000 through 2008 (5 to 12% per year), thus increasing bioavailable nitrogen delivered to the Mississippi River and affecting Gulf Coast hypoxia. The increase in nitrate concentrations with distance downstream is much greater during the post-impoundment period. If strategies to decrease total-nitrogen loads focus on particulate N, substantial decreases will be difficult because particulate nitrogen is now only 23% of total nitrogen in the Missouri River. A strategy aimed at decreasing particulates also could further exacerbate land loss along the Gulf of Mexico, which has been sediment starved since Missouri River impoundment. In contrast, strategies or benchmarks aimed at decreasing nitrate loads could substantially decrease nitrogen loadings because nitrates now constitute over half of the Missouri's nitrogen input to the Mississippi. Ongoing restoration and creation

  5. From lithotroph- to organotroph-dominant: directional shift of microbial community in sulphidic tailings during phytostabilization

    PubMed Central

    Li, Xiaofang; Bond, Philip L.; Van Nostrand, Joy D.; Zhou, Jizhong; Huang, Longbin

    2015-01-01

    Engineering microbial diversity to enhance soil functions may improve the success of direct revegetation in sulphidic mine tailings. Therefore, it is essential to explore how remediation and initial plant establishment can alter microbial communities, and, which edaphic factors control these changes under field conditions. A long-term revegetation trial was established at a Pb-Zn-Cu tailings impoundment in northwest Queensland. The control and amended and/or revegetated treatments were sampled from the 3-year-old trial. In total, 24 samples were examined using pyrosequencing of 16S rRNA genes and various chemical properties. The results showed that the microbial diversity was positively controlled by soil soluble Si and negatively controlled by soluble S, total Fe and total As, implying that pyrite weathering posed a substantial stress on microbial development in the tailings. All treatments were dominated by typical extremophiles and lithotrophs, typically Truepera, Thiobacillus, Rubrobacter; significant increases in microbial diversity, biomass and frequency of organotrophic genera (typically Nocardioides and Altererythrobacter) were detected in the revegetated and amended treatment. We concluded that appropriate phytostabilization options have the potential to drive the microbial diversity and community structure in the tailings toward those of natural soils, however, inherent environmental stressors may limit such changes. PMID:26268667

  6. 25 CFR 161.710 - How can impounded livestock or other property be redeemed?

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 25 Indians 1 2011-04-01 2011-04-01 false How can impounded livestock or other property be redeemed? 161.710 Section 161.710 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAND AND WATER NAVAJO PARTITIONED LANDS GRAZING PERMITS Trespass Actions § 161.710 How can impounded livestock or other...

  7. 25 CFR 161.710 - How can impounded livestock or other property be redeemed?

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 25 Indians 1 2014-04-01 2014-04-01 false How can impounded livestock or other property be redeemed? 161.710 Section 161.710 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAND AND WATER NAVAJO PARTITIONED LANDS GRAZING PERMITS Trespass Actions § 161.710 How can impounded livestock or other...

  8. 25 CFR 161.710 - How can impounded livestock or other property be redeemed?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 25 Indians 1 2010-04-01 2010-04-01 false How can impounded livestock or other property be redeemed? 161.710 Section 161.710 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAND AND WATER NAVAJO PARTITIONED LANDS GRAZING PERMITS Trespass Actions § 161.710 How can impounded livestock or other...

  9. 25 CFR 161.711 - How will BIA sell impounded livestock or other property?

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 25 Indians 1 2012-04-01 2011-04-01 true How will BIA sell impounded livestock or other property? 161.711 Section 161.711 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAND AND WATER NAVAJO PARTITIONED LANDS GRAZING PERMITS Trespass Actions § 161.711 How will BIA sell impounded livestock...

  10. 25 CFR 161.710 - How can impounded livestock or other property be redeemed?

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 25 Indians 1 2013-04-01 2013-04-01 false How can impounded livestock or other property be redeemed? 161.710 Section 161.710 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAND AND WATER NAVAJO PARTITIONED LANDS GRAZING PERMITS Trespass Actions § 161.710 How can impounded livestock or other...

  11. 25 CFR 161.710 - How can impounded livestock or other property be redeemed?

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 25 Indians 1 2012-04-01 2011-04-01 true How can impounded livestock or other property be redeemed? 161.710 Section 161.710 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAND AND WATER NAVAJO PARTITIONED LANDS GRAZING PERMITS Trespass Actions § 161.710 How can impounded livestock or other...

  12. 25 CFR 161.711 - How will BIA sell impounded livestock or other property?

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 25 Indians 1 2011-04-01 2011-04-01 false How will BIA sell impounded livestock or other property? 161.711 Section 161.711 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAND AND WATER NAVAJO PARTITIONED LANDS GRAZING PERMITS Trespass Actions § 161.711 How will BIA sell impounded livestock...

  13. 25 CFR 161.711 - How will BIA sell impounded livestock or other property?

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 25 Indians 1 2014-04-01 2014-04-01 false How will BIA sell impounded livestock or other property? 161.711 Section 161.711 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAND AND WATER NAVAJO PARTITIONED LANDS GRAZING PERMITS Trespass Actions § 161.711 How will BIA sell impounded livestock...

  14. 25 CFR 161.711 - How will BIA sell impounded livestock or other property?

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 25 Indians 1 2013-04-01 2013-04-01 false How will BIA sell impounded livestock or other property? 161.711 Section 161.711 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAND AND WATER NAVAJO PARTITIONED LANDS GRAZING PERMITS Trespass Actions § 161.711 How will BIA sell impounded livestock...

  15. 25 CFR 161.711 - How will BIA sell impounded livestock or other property?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 25 Indians 1 2010-04-01 2010-04-01 false How will BIA sell impounded livestock or other property? 161.711 Section 161.711 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAND AND WATER NAVAJO PARTITIONED LANDS GRAZING PERMITS Trespass Actions § 161.711 How will BIA sell impounded livestock...

  16. Methylmercury in flood-control impoundments and natural waters of northwestern Minnesota, 1997-99

    USGS Publications Warehouse

    Brigham, M.E.; Krabbenhoft, D.P.; Olson, M.L.; DeWild, J.F.

    2002-01-01

    We studied methylmercury (MeHg) and total mercury (HgT) in impounded and natural surface waters in northwestern Minnesota, in settings ranging from agricultural to undeveloped. In a recently constructed (1995) permanent-pool impoundment, MeHg levels typically increased from inflow to outflow during 1997; this trend broke down from late 1998 to early 1999. MeHg levels in the outflow reached seasonal maxima in mid-summer (maximum of 1.0 ng L−1 in July 1997) and late-winter (maximum of 6.6 ng L−1 in February 1999), and are comparable to high levels observed in new hydroelectric reservoirs in Canada. Spring and autumn MeHg levels were typically about 0.1–0.2 ng L−1. Overall, MeHg levels in both the inflow (a ditch that drains peatlands) and outflow were significantly higher than in three nearby reference natural lakes. Eleven older permanent-pool impoundments and six natural lakes in northwestern Minnesota were sampled five times. The impoundments typically had higher MeHg levels (0.071–8.36 ng L−1) than natural lakes. Five of six lakes MeHg levels typical of uncontaminated lakes (0.014–1.04 ng L−1) with highest levels in late winter, whereas a hypereutrophic lake had high levels (0.37–3.67 ng L−1) with highest levels in mid-summer. Seven temporary-pool impoundments were sampled during summer high-flow events. Temporary-pool impoundments that retained water for about 10–15 days after innundation yielded pronounced increases in MeHg from inflow to outflow, in one case reaching 4.6 ng L−1, which was about 2 ng L−1 greater than the mean inflow concentration during the runoff event.

  17. Effects of reservoir impoundment on fish assemblages in the Wujiang River of China

    NASA Astrophysics Data System (ADS)

    Zhu, D.; Yang, Z.

    2016-08-01

    Fishery catches were investigated during the spring and autumn in the period 2006-2010. The fish assemblages’ composition and dynamics were analysed and compared under the pressure of the Pengshui Reservoir impoundment. A total of 101 species were sampled in the lower Wujiang River. 78 species and 83 species were found in the upper and the lower reaches, respectively. After impoundment there were five species in the Yanhe branch and nine species in the Pengshui branch. The abundance of species was higher in the Pengshui than in the Yanhe. Fish abundance did not change in the first year of impoundment (2008) in the Lujiao- Gongtan reach, but it dramatically declined by 45.95% in 2009. The fish were subdivided into three groups and two ecotypes according to their time-series appearance in fish catches and their habitat preference. Species composition changed significantly with decreases in numbers of lotic species. Fish assemblages responded more rapidly and dramatically to impoundment in the reservoir section than the section below the Pengshui Dam.

  18. The flotation tailings of the former Pb-Zn mine of Touiref (NW Tunisia): mineralogy, mine drainage prediction, base-metal speciation assessment and geochemical modeling.

    PubMed

    Othmani, Mohamed Ali; Souissi, Fouad; Bouzahzah, Hassan; Bussière, Bruno; da Silva, Eduardo Ferreira; Benzaazoua, Mostafa

    2015-02-01

    The underground extraction of Pb-Zn mineralization in the Touiref area stopped in 1958. A large volume of flotation tailings (more than 500 Mt) containing sulfides were deposited in a tailings impoundment. The goals of this study are to evaluate the neutralization capacity of the unoxidized and oxidized tailings, to assess the speciation of metals between the different components of the tailings material, and to assess the mobility of metals and the secondary minerals' precipitation in pore waters using geochemical modeling. To accomplish these objectives, representative samples from both fresh and oxidized zones were collected along a vertical profile through the tailings pile. Physical, chemical (ICP-MS), and mineralogical characterization (X-ray diffraction (XRD), reflected light microscopy, scanning electron microscope (SEM)) of these samples was performed. Grain size analysis shows that the tailings are dominated by silt- to sand-sized fractions. The microscopic observation highlights the presence of pyrite, marcasite, galena, and sphalerite as primary minerals in a carbonated matrix. The study reveals also the presence of secondary minerals represented by cerussite, smithsonite, anglesite, and Fe oxi-hydroxides as important scavengers for trace elements. The static tests show that the presence of calcite in the tailing samples ensures acid-neutralizing capacity (ANC), which is significantly greater than the acidity potential (PA). The geochemical characterization of the unoxidized samples shows higher Cd, Pb, and Zn concentrations than the oxidized samples containing the highest values for Fe and SO4. Sequential extraction tests show that significant percentages of metals are distributed between the acid-soluble fractions (Cd, Pb, and Zn) and the reducible one (Zn). Pore water analysis indicates that Ca is the dominant cation (8,170 and 6,200 mg L(-1), respectively), whereas sulfate is the principal anion (6,900 and 5,100 mg L(-1), respectively). Saturation

  19. 40 CFR 265.1086 - Standards: Surface impoundments.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... floating membrane cover in accordance with the provisions specified in paragraph (c) of this section; or (2... emissions from a surface impoundment using a floating membrane cover shall meet the requirements specified... with a floating membrane cover designed to meet the following specifications: (i) The floating membrane...

  20. 40 CFR 63.7907 - What are my inspection and monitoring requirements for surface impoundments?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 13 2010-07-01 2010-07-01 false What are my inspection and monitoring requirements for surface impoundments? 63.7907 Section 63.7907 Protection of Environment ENVIRONMENTAL... Remediation Surface Impoundments § 63.7907 What are my inspection and monitoring requirements for surface...

  1. 40 CFR 63.7907 - What are my inspection and monitoring requirements for surface impoundments?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 14 2013-07-01 2013-07-01 false What are my inspection and monitoring requirements for surface impoundments? 63.7907 Section 63.7907 Protection of Environment ENVIRONMENTAL... Remediation Surface Impoundments § 63.7907 What are my inspection and monitoring requirements for surface...

  2. 40 CFR 63.7907 - What are my inspection and monitoring requirements for surface impoundments?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 14 2014-07-01 2014-07-01 false What are my inspection and monitoring requirements for surface impoundments? 63.7907 Section 63.7907 Protection of Environment ENVIRONMENTAL... Remediation Surface Impoundments § 63.7907 What are my inspection and monitoring requirements for surface...

  3. 40 CFR 63.7907 - What are my inspection and monitoring requirements for surface impoundments?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 14 2012-07-01 2011-07-01 true What are my inspection and monitoring requirements for surface impoundments? 63.7907 Section 63.7907 Protection of Environment ENVIRONMENTAL... Remediation Surface Impoundments § 63.7907 What are my inspection and monitoring requirements for surface...

  4. 40 CFR 63.7907 - What are my inspection and monitoring requirements for surface impoundments?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 13 2011-07-01 2011-07-01 false What are my inspection and monitoring requirements for surface impoundments? 63.7907 Section 63.7907 Protection of Environment ENVIRONMENTAL... Remediation Surface Impoundments § 63.7907 What are my inspection and monitoring requirements for surface...

  5. Self-assembly behavior of tail-to-tail superstructure formed by mono-6-O-(4-carbamoylmethoxy-benzoyl)-β-cyclodextrin in solution and the solid state.

    PubMed

    Xu, Zhe; Chen, Xin; Liu, Jing; Yan, Dong-Qing; Diao, Chun-Hua; Guo, Min-Jie; Fan, Zhi

    2014-07-01

    A novel mono-modified β-cyclodextrin (β-CD) consisting of 4-carbamoylmethoxy-benzoyl unit at the primary side was synthesized and its self-assembly behavior was determined by X-ray crystallography and NMR spectroscopy. The crystal structure shows a 'Yin-Yang'-like packing mode, in which the modified β-CD exhibits a channel superstructure formed by a tail-to-tail dimer as the repeating motif with the substituted group embedded within the hydrophobic cavity of the facing β-CD. The geometry of the substituted group is determined by the inclusion of the cavity and is further stabilized by two intermolecular hydrogen bonds between the carbonyl O atom and phenyl group. Furthermore, NMR ROESY investigation indicates that the self-assembly behavior of the substituted group within the β-CD cavity is retained in aqueous solution, and the effective binding constant Ka was calculated to be 1330 M(-1) by means of (1)H NMR titration according to iterative determination. Copyright © 2014 Elsevier Ltd. All rights reserved.

  6. 32 CFR 634.49 - Standards for impoundment.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... CRIMINAL INVESTIGATIONS MOTOR VEHICLE TRAFFIC SUPERVISION Impounding Privately Owned Vehicles § 634.49... ongoing operations or movement of traffic, threaten public safety or convenience, are involved in criminal...— (i) On a street or bridge, in a tunnel, or is double parked, and interferes with the orderly flow of...

  7. 32 CFR 634.49 - Standards for impoundment.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... CRIMINAL INVESTIGATIONS MOTOR VEHICLE TRAFFIC SUPERVISION Impounding Privately Owned Vehicles § 634.49... ongoing operations or movement of traffic, threaten public safety or convenience, are involved in criminal...— (i) On a street or bridge, in a tunnel, or is double parked, and interferes with the orderly flow of...

  8. 32 CFR 634.49 - Standards for impoundment.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... CRIMINAL INVESTIGATIONS MOTOR VEHICLE TRAFFIC SUPERVISION Impounding Privately Owned Vehicles § 634.49... ongoing operations or movement of traffic, threaten public safety or convenience, are involved in criminal...— (i) On a street or bridge, in a tunnel, or is double parked, and interferes with the orderly flow of...

  9. 32 CFR 634.49 - Standards for impoundment.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... CRIMINAL INVESTIGATIONS MOTOR VEHICLE TRAFFIC SUPERVISION Impounding Privately Owned Vehicles § 634.49... ongoing operations or movement of traffic, threaten public safety or convenience, are involved in criminal...— (i) On a street or bridge, in a tunnel, or is double parked, and interferes with the orderly flow of...

  10. 32 CFR 634.51 - Procedures for impoundment.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 32 National Defense 4 2013-07-01 2013-07-01 false Procedures for impoundment. 634.51 Section 634.51 National Defense Department of Defense (Continued) DEPARTMENT OF THE ARMY (CONTINUED) LAW... in the installation law enforcement desk journal or blotter. (2) The owner will be allowed 3 days...

  11. 32 CFR 634.51 - Procedures for impoundment.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 32 National Defense 4 2011-07-01 2011-07-01 false Procedures for impoundment. 634.51 Section 634.51 National Defense Department of Defense (Continued) DEPARTMENT OF THE ARMY (CONTINUED) LAW... in the installation law enforcement desk journal or blotter. (2) The owner will be allowed 3 days...

  12. The Tail Suspension Test

    PubMed Central

    Terrillion, Chantelle E.; Piantadosi, Sean C.; Bhat, Shambhu; Gould, Todd D.

    2012-01-01

    The tail-suspension test is a mouse behavioral test useful in the screening of potential antidepressant drugs, and assessing of other manipulations that are expected to affect depression related behaviors. Mice are suspended by their tails with tape, in such a position that it cannot escape or hold on to nearby surfaces. During this test, typically six minutes in duration, the resulting escape oriented behaviors are quantified. The tail-suspension test is a valuable tool in drug discovery for high-throughput screening of prospective antidepressant compounds. Here, we describe the details required for implementation of this test with additional emphasis on potential problems that may occur and how to avoid them. We also offer a solution to the tail climbing behavior, a common problem that renders this test useless in some mouse strains, such as the widely used C57BL/6. Specifically, we prevent tail climbing behaviors by passing mouse tails through a small plastic cylinder prior to suspension. Finally, we detail how to manually score the behaviors that are manifested in this test. PMID:22315011

  13. Waterbird use of coastal impoundments and management implications in east-central Florida

    NASA Technical Reports Server (NTRS)

    Breininger, David R.; Smith, Rebecca B.

    1990-01-01

    Monthly surveys were conducted on Kennedy Space Center for one year to determine densities of waterbirds within impounded salt marshes that were predominantly open water with little emergent vegetation. The objective was to assess the importance of these impoundments to waterbirds, particularly wading birds, which are species of special conservation concern. Water-level management for mosquito control and waterfowl provided habitat for an abundance of ducks, shorebirds, coots, and wading birds. Average densities throughout the year for these groups were 5.26, 412, 2.80, and 2.20 birds/ha, respectively. The majority of waterfowl were present during the winter. Shorebirds were most common during spring migration. Wading bird densities increased with declining water level. Due to the extensive alteration and development of coastal wetlands in central Florida, properly managed impoundments may provide important feeding areas for maintaining certain waterbird populations.

  14. Effects of seasonal drawdowns on fish assemblages in sections of an impounded river-canal system in upstate New York

    USGS Publications Warehouse

    George, Scott D.; Baldigo, Barry P.; Wells, Scott M

    2016-01-01

    The Mohawk River and New York State Barge Canal run together as a series of permanent and temporary impoundments for most of the distance between Rome and Albany, New York. The downstream or lower section is composed of two permanent impoundments, the middle section of a series of temporary (seasonal) impoundments, and the upper section of a series of permanent impoundments. In the middle section, movable dams are lifted from the water during winter and the wetted surface area decreases by 36–56%. We used boat electrofishing during spring 2014 and 2015 to compare the relative abundance of fish populations and the composition of fish assemblages between the permanently and seasonally impounded sections of the Barge Canal and to infer the effects of the two flow management practices. A total of 3,264 individuals from 38 species were captured, and total catch per unit effort (CPUE) ranged from 46.0 to 134.7 fish/h at sites in the seasonally impounded section, compared with 140.0–342.0 fish/h in the permanent lower section and 89.0–282.0 fish/h in the permanent upper section. The amount of drawdown explained 55% of the variation in total CPUE and was a highly significant predictor variable. Mean total CPUE in the seasonally impounded section was significantly lower (by about 50%) than that in either permanently impounded section, and the assemblage composition differed significantly between sections. The relative abundance of many lentic species was markedly lower in the seasonally impounded section, while the relative abundance of several native cyprinids and the percentage of individuals belonging to species that are native to the watershed was greater in this section. Overall, these findings suggest that winter dam removal in impounded rivers may reduce the abundance of fish but may also create more natural riverine conditions that favor some native species.

  15. The Tail of BPM

    NASA Astrophysics Data System (ADS)

    Kruba, Steve; Meyer, Jim

    Business process management suites (BPMS's) represent one of the fastest growing segments in the software industry as organizations automate their key business processes. As this market matures, it is interesting to compare it to Chris Anderson's 'Long Tail.' Although the 2004 "Long Tail" article in Wired magazine was primarily about the media and entertainment industries, it has since been applied (and perhaps misapplied) to other markets. Analysts describe a "Tail of BPM" market that is, perhaps, several times larger than the traditional BPMS product market. This paper will draw comparisons between the concepts in Anderson's article (and subsequent book) and the BPM solutions market.

  16. An Object-Based Machine Learning Classification Procedure for Mapping Impoundments in Brazil's Amazon-Cerrado Agricultural Frontier

    NASA Astrophysics Data System (ADS)

    Solvik, K.; Macedo, M.; Graesser, J.; Lathuilliere, M. J.

    2017-12-01

    Large-scale agriculture and cattle ranching in Brazil has driving the creation of tens of thousands of small stream impoundments to provide water for crops and livestock. These impoundments are a source of methane emissions and have significant impacts on stream temperature, connectivity, and water use over a large region. Due to their large numbers and small size, they are difficult to map using conventional methods. Here, we present a two-stage object-based supervised classification methodology for identifying man-made impoundments in Brazil. First, in Google Earth Engine pixels are classified as water or non-water using satellite data and HydroSHEDS products as predictors. Second, using Python's scikit-learn and scikit-image modules the water objects are classified as man-made or natural based on a variety of shape and spectral properties. Both classifications are performed by a random forest classifier. Training data is acquired by visually identifying impoundments and natural water bodies using high resolution satellite imagery from Google Earth.This methodology was applied to the state of Mato Grosso using a cloud-free mosaic of Sentinel 1 (10m resolution) radar and Sentinel 2 (10-20m) multispectral data acquired during the 2016 dry season. Independent test accuracy was estimated at 95% for the first stage and 93% for the second. We identified 54,294 man-made impoundments in Mato Grosso in 2016. The methodology is generalizable to other high resolution satellite data and has been tested on Landsat 5 and 8 imagery. Applying the same approach to Landsat 8 images (30 m), we identified 35,707 impoundments in the 2015 dry season. The difference in number is likely because the coarser-scale imagery fails to detect small (< 900 m2) objects. On-going work will apply this approach to satellite time series for the entire Amazon-Cerrado frontier, allowing us to track changes in the number, size, and distribution of man-made impoundments. Automated impoundment mapping

  17. 32 CFR 634.51 - Procedures for impoundment.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 32 National Defense 4 2010-07-01 2010-07-01 true Procedures for impoundment. 634.51 Section 634.51 National Defense Department of Defense (Continued) DEPARTMENT OF THE ARMY (CONTINUED) LAW ENFORCEMENT AND... installation law enforcement desk journal or blotter. (2) The owner will be allowed 3 days from the date the...

  18. 32 CFR 634.51 - Procedures for impoundment.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 32 National Defense 4 2012-07-01 2011-07-01 true Procedures for impoundment. 634.51 Section 634.51 National Defense Department of Defense (Continued) DEPARTMENT OF THE ARMY (CONTINUED) LAW ENFORCEMENT AND... installation law enforcement desk journal or blotter. (2) The owner will be allowed 3 days from the date the...

  19. 32 CFR 634.51 - Procedures for impoundment.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 32 National Defense 4 2014-07-01 2013-07-01 true Procedures for impoundment. 634.51 Section 634.51 National Defense Department of Defense (Continued) DEPARTMENT OF THE ARMY (CONTINUED) LAW ENFORCEMENT AND... installation law enforcement desk journal or blotter. (2) The owner will be allowed 3 days from the date the...

  20. Transport and dispersion of pollutants in surface impoundments: a finite difference model

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Yeh, G.T.

    1980-07-01

    A surface impoundment model by finite-difference (SIMFD) has been developed. SIMFD computes the flow rate, velocity field, and the concentration distribution of pollutants in surface impoundments with any number of islands located within the region of interest. Theoretical derivations and numerical algorithm are described in detail. Instructions for the application of SIMFD and listings of the FORTRAN IV source program are provided. Two sample problems are given to illustrate the application and validity of the model.

  1. 25 CFR 166.810 - How do I redeem my impounded livestock or other property?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 25 Indians 1 2010-04-01 2010-04-01 false How do I redeem my impounded livestock or other property? 166.810 Section 166.810 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAND AND WATER GRAZING PERMITS Trespass Actions § 166.810 How do I redeem my impounded livestock or other property? You...

  2. 25 CFR 166.810 - How do I redeem my impounded livestock or other property?

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 25 Indians 1 2011-04-01 2011-04-01 false How do I redeem my impounded livestock or other property? 166.810 Section 166.810 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAND AND WATER GRAZING PERMITS Trespass Actions § 166.810 How do I redeem my impounded livestock or other property? You...

  3. 25 CFR 166.810 - How do I redeem my impounded livestock or other property?

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 25 Indians 1 2013-04-01 2013-04-01 false How do I redeem my impounded livestock or other property? 166.810 Section 166.810 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAND AND WATER GRAZING PERMITS Trespass Actions § 166.810 How do I redeem my impounded livestock or other property? You...

  4. 25 CFR 166.810 - How do I redeem my impounded livestock or other property?

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 25 Indians 1 2012-04-01 2011-04-01 true How do I redeem my impounded livestock or other property? 166.810 Section 166.810 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAND AND WATER GRAZING PERMITS Trespass Actions § 166.810 How do I redeem my impounded livestock or other property? You...

  5. 25 CFR 166.810 - How do I redeem my impounded livestock or other property?

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 25 Indians 1 2014-04-01 2014-04-01 false How do I redeem my impounded livestock or other property? 166.810 Section 166.810 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAND AND WATER GRAZING PERMITS Trespass Actions § 166.810 How do I redeem my impounded livestock or other property? You...

  6. Cumuilative Effects of Impoundments on the Hydrology of Riparian Wetlands along the Marmaton River, west-central Missouri

    USGS Publications Warehouse

    Heimann, David C.; Krempa, Heather M.

    2011-01-01

    The effects of proposed impoundments and resulting streamflow regulation on riparian wetlands in the Marmaton River Basin, Missouri, USA were determined using measurements and numerical simulations of wetland water budgets. Calibrated and validated Soil-Plant-Air-Water (SPAW) models were used to simulate daily water depths of four riparian wetlands for Current (model scenario of existing impoundments) and Proposed (model scenario of existing and proposed impoundments) impoundment conditions. The simulated frequency of flooding decreased 19–65% at the wetlands following the additions of proposed impoundments. The reduced flooding resulted in decreases in wetland water depths at all sites during the 10 simulated growing seasons under Proposed conditions with an average duration of continuous water-depth declines of 289 days at the upstream (most regulated) site. Downstream wetlands within the zone of least regulation had an average duration of water level decreases of about 20 days. Decreased water levels under Proposed conditions resulted in a range of 65–365 additional dry days at the study wetlands during the simulated 10-year period of Proposed conditions. The areas of the four wetlands meeting the hydrologic criteria of a formal jurisdictional wetland definition decreased ranging from zero to 31% under Proposed impoundment conditions.

  7. Reaction of Hardwood Timber to Shallow-Water Impoundments

    Treesearch

    W. M. Broadfoot

    1958-01-01

    In recent years farmers and sportsmen have built many temporary shallow-water impoundments in southern hardwood forests. While the main purpose has been to attract waterfowl, a recent study shows that these forest lakes, if properly managed, can also benefit the timber.

  8. 32 CFR 634.23 - Specified consent to impoundment.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... ENFORCEMENT AND CRIMINAL INVESTIGATIONS MOTOR VEHICLE TRAFFIC SUPERVISION Motor Vehicle Registration § 634.23... installation traffic code provide for the removal and temporary impoundment of privately owned motor vehicles..., creating a safety hazard, disabled by accident, left unattended in a restricted or control area, or...

  9. Stochastic Modelling of the Hydraulic Anisotropy of Ash Impoundment Sediment

    NASA Astrophysics Data System (ADS)

    Slávik, Ivan

    2017-12-01

    In the case reported here the impoundments of a 400 MW coal heated power plant with an annual production of about 1.5 million tons of fuel ash are of the cross-valley type, operated by the simple and cheap „upstream method”. The aim of the research was to determine overall and local values of the permeability in horizontal as well as in vertical direction and the anisotropy of the thin-layered sedimented ash. The coal ashes are hydraulically transported through pipelines in form of a slurry and periodically floated on the beach of the impoundment. The ashes are deposited in the form of a thin-layered sediment, with random alternation of layers with a coarser or finer granularity. The ash impoundment sediment is anthropogenic sediment with horizontally laminated texture. Therefore, the sediment is anisotropic from the viewpoint of water seepage. The knowledge of the permeability and the seepage anisotropy of the sediment is a basic requirement for the design of an appropriate dewatering system. The seepage anisotropy of the ash sediment has been checked by means of stochastic modelling, based on the correlation between the effective grain diameter and the coefficient of permeability of the ash: the effective grain diameter and the thickness of individual layers have been proposed to be random events.

  10. Impoundment of the Zipingpu reservoir and triggering of the 2008 Mw 7.9 Wenchuan earthquake, China

    PubMed Central

    Tao, Wei; Masterlark, Timothy; Ronchin, Erika

    2015-01-01

    Abstract Impoundment of the Zipingpu reservoir (ZR), China, began in September 2005 and was followed 2.7 years later by the 2008 Mw 7.9 Wenchuan earthquake (WE) rupturing the Longmen Shan Fault (LSF), with its epicenter ~12 km away from the ZR. Based on the poroelastic theory, we employ three‐dimensional finite element models to simulate the evolution of stress and pore pressure due to reservoir impoundment, and its effect on the Coulomb failure stress on the LSF. The results indicate that the reservoir impoundment formed a pore pressure front that slowly propagated through the crust with fluid diffusion. The reservoir loading induced either moderate or no increase of the Coulomb failure stress at the hypocenter prior to the WE. The Coulomb failure stress, however, grew ~9.3–69.1 kPa in the depth range of 1–8 km on the LSF, which may have advanced tectonic loading of the fault system by ~60–450 years. Due to uncertainties of fault geometry and hypocenter location of the WE, it is inconclusive whether impoundment of the ZR directly triggered the WE. However, a small event at the hypocenter could have triggered large rupture elsewhere on fault, where the asperities were weakened by the ZR. The microseismicity around the ZR also showed an expanding pattern from the ZR since its impoundment, likely associated with diffusion of a positive pore pressure pulse. These results suggest a poroelastic triggering effect (even if indirectly) of the WE due to the impoundment of the ZR. PMID:27812436

  11. Fate of Radium in Marcellus Shale Flowback Water Impoundments and Assessment of Associated Health Risks.

    PubMed

    Zhang, Tieyuan; Hammack, Richard W; Vidic, Radisav D

    2015-08-04

    Natural gas extraction from Marcellus Shale generates large quantities of flowback water that contain high levels of salinity, heavy metals, and naturally occurring radioactive material (NORM). This water is typically stored in centralized storage impoundments or tanks prior to reuse, treatment or disposal. The fate of Ra-226, which is the dominant NORM component in flowback water, in three centralized storage impoundments in southwestern Pennsylvania was investigated during a 2.5-year period. Field sampling revealed that Ra-226 concentration in these storage facilities depends on the management strategy but is generally increasing during the reuse of flowback water for hydraulic fracturing. In addition, Ra-226 is enriched in the bottom solids (e.g., impoundment sludge), where it increased from less than 10 pCi/g for fresh sludge to several hundred pCi/g for aged sludge. A combination of sequential extraction procedure (SEP) and chemical composition analysis of impoundment sludge revealed that Barite is the main carrier of Ra-226 in the sludge. Toxicity characteristic leaching procedure (TCLP) (EPA Method 1311) was used to assess the leaching behavior of Ra-226 in the impoundment sludge and its implications for waste management strategies for this low-level radioactive solid waste. Radiation exposure for on-site workers calculated using the RESRAD model showed that the radiation dose equivalent for the baseline conditions was well below the NRC limit for the general public.

  12. Sediment organic carbon distribution in 4 small northern Missouri impoundments: implications for sampling and carbon sequestration

    USDA-ARS?s Scientific Manuscript database

    Recent research suggests that the rate of sediment carbon storage of small agricultural impoundments may be of similar magnitude on a per unit area as that of the world’s oceans. However, the role of small impoundments in the carbon budget has not received adequate attention; indeed availability of ...

  13. Recent accretion in two managed marsh impoundments in coastal Louisiana

    USGS Publications Warehouse

    Cahoon, D.R.

    1994-01-01

    Recent accretion was measured by the feldspar marker horizon method in two gravity-drained, managed, marsh impoundments and unmanaged reference marshes located on the rapidly subsiding coast of Louisiana. Water level management was designed to limit hydrologic exchange to the managed marsh by regulating the direction and rate of water flows. During a drawdown-flooding water management cycle, the unmanaged reference marshes had significantly higher vertical accretion rates, higher soil bulk density and soil mineral matter content, lower soil organic matter content, and higher rates of organic matter accumulation than the managed marsh. The rate of mineral matter accumulation was higher in both reference marshes, but was significantly higher in only one. Spatial variability in accumulation rates was low when analyzed in one managed marsh site, suggesting a primarily autochthonous source of matter. In contrast, the associated reference marsh apparently received allochthonous material that settled out in a distinct spatial pattern as water velocity decreased. The impoundment marshes experienced an accretion deficit of one full order of magnitude (0.1 vs. 1.0 m/yr) based on comparison of accretion and sea level rise data, while the unmanaged reference marshes experienced a five-fold smaller deficit or no deficit. These data suggest that the gravity-drained impoundments likely have a shorter life expectancy than the reference marshes in the rapidly subsiding Louisiana coast.

  14. 36 CFR 262.12 - Impounding of personal property.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... of the trespass is mailed by registered mail or delivered to such owner. (b) In the event the local... 15 days after the date a notice of intention to impound the property in trespass is first published... the site occupied during the period of the trespass. (d) If the personal property is not redeemed on...

  15. LCDRS FLOW FROM DOUBLE-LINED LANDFILLS AND SURFACE IMPOUNDMENTS

    EPA Science Inventory

    This report presents field data on the measured flows of liquid from the leakage detection, collection, and removal systems (LDCRSs) of 28 double-lined surface impoundment facilities. or each facility, information on design and operation is presented, as is an evaluation of the s...

  16. Geochemical behavior and environmental risks related to the use of abandoned base-metal tailings as construction material in the upper-Moulouya district, Morocco.

    PubMed

    Argane, R; El Adnani, M; Benzaazoua, M; Bouzahzah, H; Khalil, A; Hakkou, R; Taha, Y

    2016-01-01

    In some developing countries, base-metal residues that were abandoned in tailing ponds or impoundments are increasingly used as construction material without any control, engineering basis, or environmental concern. This uncontrolled reuse of mine tailings may constitute a new form of pollution risks for humans and ecosystems through metal leaching. Therefore, the aim of the current study is to assess mine drainage, metal mobility, and geochemical behavior of two abandoned mine tailings commonly used in the upper-Moulouya region (eastern Morocco) as fine aggregates for mortar preparation. Their detailed physical, chemical, and mineralogical properties were subsequently evaluated in the context of developing appropriate alternative reuses to replace their conventional disposal and limit their weathering exposure. The obtained results showed that both tailings contain relatively high quantities of residual metals and metalloids with lead (ranging between 3610 and 5940 mg/kg) being the major pollutant. However, the mineralogical investigations revealed the presence of abundant neutralizing minerals and low sulfide content which influence mine drainage geochemistry and subsequently lower metals mobility. In fact, leachate analyses from weathering cell kinetic tests showed neutral conditions and low sulfide oxidation rates. According to these results, the tailings used as construction material in the upper-Moulouya region have very low generating potential of contaminated effluents and their reuse as aggregates may constitute a sustainable alternative method for efficient tailing management.

  17. 25 CFR 166.811 - How will the sale of impounded livestock or other property be conducted?

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 25 Indians 1 2012-04-01 2011-04-01 true How will the sale of impounded livestock or other property be conducted? 166.811 Section 166.811 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAND AND WATER GRAZING PERMITS Trespass Actions § 166.811 How will the sale of impounded livestock or...

  18. 25 CFR 166.811 - How will the sale of impounded livestock or other property be conducted?

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 25 Indians 1 2014-04-01 2014-04-01 false How will the sale of impounded livestock or other property be conducted? 166.811 Section 166.811 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAND AND WATER GRAZING PERMITS Trespass Actions § 166.811 How will the sale of impounded livestock or...

  19. 25 CFR 166.811 - How will the sale of impounded livestock or other property be conducted?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 25 Indians 1 2010-04-01 2010-04-01 false How will the sale of impounded livestock or other property be conducted? 166.811 Section 166.811 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAND AND WATER GRAZING PERMITS Trespass Actions § 166.811 How will the sale of impounded livestock or...

  20. 25 CFR 166.811 - How will the sale of impounded livestock or other property be conducted?

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 25 Indians 1 2013-04-01 2013-04-01 false How will the sale of impounded livestock or other property be conducted? 166.811 Section 166.811 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAND AND WATER GRAZING PERMITS Trespass Actions § 166.811 How will the sale of impounded livestock or...

  1. 25 CFR 166.811 - How will the sale of impounded livestock or other property be conducted?

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 25 Indians 1 2011-04-01 2011-04-01 false How will the sale of impounded livestock or other property be conducted? 166.811 Section 166.811 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAND AND WATER GRAZING PERMITS Trespass Actions § 166.811 How will the sale of impounded livestock or...

  2. 40 CFR 63.943 - Standards-Surface impoundment vented to control device.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... the surface impoundment; the effects of outdoor exposure to wind, moisture, and sunlight; and the... shall inspect and monitor the air emission control equipment in accordance with the procedures specified...

  3. 40 CFR 63.943 - Standards-Surface impoundment vented to control device.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... the surface impoundment; the effects of outdoor exposure to wind, moisture, and sunlight; and the... shall inspect and monitor the air emission control equipment in accordance with the procedures specified...

  4. 40 CFR 63.943 - Standards-Surface impoundment vented to control device.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... the surface impoundment; the effects of outdoor exposure to wind, moisture, and sunlight; and the... shall inspect and monitor the air emission control equipment in accordance with the procedures specified...

  5. 40 CFR 63.943 - Standards-Surface impoundment vented to control device.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... the surface impoundment; the effects of outdoor exposure to wind, moisture, and sunlight; and the... shall inspect and monitor the air emission control equipment in accordance with the procedures specified...

  6. 40 CFR 63.943 - Standards-Surface impoundment vented to control device.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... the surface impoundment; the effects of outdoor exposure to wind, moisture, and sunlight; and the... shall inspect and monitor the air emission control equipment in accordance with the procedures specified...

  7. Evaluation of the grass mixture (Faestuca Rubra, Cynodon Dactylon, Lolium Multiflorum and Pennisetum sp.) as Sb phyto-stabilizer in tailings and Sb-rich soils.

    NASA Astrophysics Data System (ADS)

    Aurora Armienta, M.; Beltrán-Villavicencio, Margarita; Ruiz-Villalobos, Carlos E.; Labastida, Israel; Ceniceros, Nora; Cruz, Olivia; Aguayo, Alejandra

    2017-04-01

    Green house experiments were carried out to evaluate the growth and Sb assimilation of a grass assemblage: Faestuca Rubra, Cynodon Dactylon, Lolium Multiflorum and Pennisetum sp, in tailings and Sb-rich soils. Tailings and soil samples were obtained at the Mexican historical mining zone of Zimapán, Central México. More than 6 tailings impoundments are located at the town outskirts and constitute a contamination source from windblown and waterborne deposit on soils, besides acid mine drainage. Four substrates were used in the experiments: 100% tailings, 20% tailings + 80% soil, 50% tailings + 50% soil , and a soil sample far from tailings as a background. Concentrations of Sb ranged from 310 mg/kg to 413 mg/kg in tailings. A pH of 7.43, 1.27% organic matter, and high concentrations of N, K and P indicated adequate conditions for plant growth. The grass assemblage was raised during 21 days as indicated by OECD (Organisation for Economic Co-operation and Development) Guideline 208 Terrestrial Plant Test: Seedling Emergence and Seedling Growth Test. The highest Sb concentrations were measured in plants grown on tailings with 139 mg/kg in the aerial part and 883 mg/kg in roots. Concentrations of Sb decreased as the proportion of tailings diminished with 22.1 mg/kg in the aerial part and 10 mg/kg in roots corresponding to the plants grown in the 20 % tailings + 80% soil . Bioaccumulation (BAC) and bioconcentration factors (BF) of plants grown on tailings (BAC= 0.42, BCF=3.93) indicated their suitability as a phyto-stabilization option. The grass mixture may be thus applied to control windblown particulate tailings taking advantage to their tolerance to high Sb levels.

  8. Unconventional tail configurations for transport aircraft

    NASA Astrophysics Data System (ADS)

    Sánchez-Carmona, A.; Cuerno-Rejado, C.; García-Hernández, L.

    2017-06-01

    This article presents the bases of a methodology in order to size unconventional tail configurations for transport aircraft. The case study of this paper is a V-tail con¦guration. Firstly, an aerodynamic study is developed for determining stability derivatives and aerodynamic forces. The objective is to size a tail such as it develops at least the same static stability derivatives than a conventional reference aircraft. The optimum is obtained minimizing its weight. The weight is estimated through two methods: adapted Farrar£s method and a statistical method. The solution reached is heavier than the reference, but it reduces the wetted area.

  9. An Exercise in Evaluating the Contamination Potential of Surface Impoundments.

    ERIC Educational Resources Information Center

    Tinker, John R., Jr.

    1982-01-01

    Outlines a laboratory procedure which enables students to evaluate the contamination potential of surface impoundments and apply basic principles of hydrogeology to the land disposal of waste material. Includes a list of materials needed and directions for the instructor. (Author/DC)

  10. 32 CFR 636.38 - Impounding privately owned vehicles (POVs).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 32 National Defense 4 2010-07-01 2010-07-01 true Impounding privately owned vehicles (POVs). 636.38 Section 636.38 National Defense Department of Defense (Continued) DEPARTMENT OF THE ARMY... action will be documented by an entry in the Military Police desk journal. (ii) The owner will be allowed...

  11. 32 CFR 636.38 - Impounding privately owned vehicles (POVs).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 32 National Defense 4 2011-07-01 2011-07-01 false Impounding privately owned vehicles (POVs). 636.38 Section 636.38 National Defense Department of Defense (Continued) DEPARTMENT OF THE ARMY... action will be documented by an entry in the Military Police desk journal. (ii) The owner will be allowed...

  12. 32 CFR 636.38 - Impounding privately owned vehicles (POVs).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 32 National Defense 4 2012-07-01 2011-07-01 true Impounding privately owned vehicles (POVs). 636.38 Section 636.38 National Defense Department of Defense (Continued) DEPARTMENT OF THE ARMY... action will be documented by an entry in the Military Police desk journal. (ii) The owner will be allowed...

  13. 32 CFR 636.38 - Impounding privately owned vehicles (POVs).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 32 National Defense 4 2014-07-01 2013-07-01 true Impounding privately owned vehicles (POVs). 636.38 Section 636.38 National Defense Department of Defense (Continued) DEPARTMENT OF THE ARMY... action will be documented by an entry in the Military Police desk journal. (ii) The owner will be allowed...

  14. 32 CFR 636.38 - Impounding privately owned vehicles (POVs).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 32 National Defense 4 2013-07-01 2013-07-01 false Impounding privately owned vehicles (POVs). 636.38 Section 636.38 National Defense Department of Defense (Continued) DEPARTMENT OF THE ARMY... action will be documented by an entry in the Military Police desk journal. (ii) The owner will be allowed...

  15. Effect of ship locking on sediment oxygen uptake in impounded rivers

    NASA Astrophysics Data System (ADS)

    Lorke, A.; McGinnis, D. F.; Maeck, A.; Fischer, H.

    2012-12-01

    In the majority of large river systems, flow is regulated and/or otherwise affected by operational and management activities, such as ship locking. The effect of lock operation on sediment-water oxygen fluxes was studied within a 12.9 km long impoundment at the Saar River (Germany) using eddy-correlation flux measurements. The continuous observations cover a time period of nearly 5 days and 39 individual locking events. Ship locking is associated with the generation of surges propagating back and forth through the impoundment which causes strong variations of near-bed current velocity and turbulence. These wave-induced flow variations cause variations in sediment-water oxygen fluxes. While the mean flux during time periods without lock operation was 0.5 ± 0.1 g m-2 d-1, it increased by about a factor of 2 to 1.0 ± 0.5 g m-2 d-1within time periods with ship locking. Following the daily schedule of lock operations, fluxes are predominantly enhanced during daytime and follow a pronounced diurnal rhythm. The driving force for the increased flux is the enhancement of diffusive transport across the sediment-water interface by bottom-boundary layer turbulence and perhaps resuspension. Additional means by which the oxygen budget of the impoundment is affected by lock-induced flow variations are discussed.

  16. Patterns of fish use and piscivore abundance within a reconnected saltmarsh impoundment in the northern Indian River Lagoon, Florida

    USGS Publications Warehouse

    Stevens, Philip W.; Montague, C.L.; Sulak, K.J.

    2006-01-01

    Nearly all saltmarshes in east-central, Florida were impounded for mosquito control during the 1960s. The majority of these marshes have since been reconnected to the estuary by culverts, providing an opportunity to effectively measure exchange of aquatic organisms. A multi-gear approach was used monthly to simultaneously estimate fish standing stock (cast net), fish exchange with the estuary (culvert traps), and piscivore abundance (gill nets and bird counts) to document patterns of fish use in a reconnected saltmarsh impoundment. Changes in saltmarsh fish abundance, and exchange of fish with the estuary reflected the seasonal pattern of marsh flooding in the northern Indian River Lagoon system. During a 6-month period of marsh flooding, resident fish had continuous access to the marsh surface. Large piscivorous fish regularly entered the impoundment via creeks and ditches to prey upon small resident fish, and piscivorous birds aggregated following major fish movements to the marsh surface or to deep habitats. As water levels receded in winter, saltmarsh fish concentrated into deep habitats and emigration to the estuary ensued (200% greater biomass left the impoundment than entered). Fish abundance and community structure along the estuary shoreline (although fringed with marsh vegetation) were not analogous to marsh creeks and ditches. Perimeter ditches provided deep-water habitat for large estuarine predators, and shallow creeks served as an alternative habitat for resident fish when the marsh surface was dry. Use of the impoundment as nursery by transients was limited to Mugil cephalus Linnaeus, but large juvenile and adult piscivorous fish used the impoundment for feeding. In conclusion, the saltmarsh impoundment was a feeding site for piscivorous fish and birds, and functioned as a net exporter of forage fish to adjacent estuarine waters. ?? Springer 2006.

  17. LOCATING AND REPAIRING LEAKS IN LANDFILL/IMPOUNDMENT FLEXIBLE MEMBRANE LINERS

    EPA Science Inventory

    In the United States, the large quantities of solid and hazardous wastes generated each year are commonly disposed of in landfills and surface impoundments. Geomembrane liners (flexible membrane liners, FMLs) are often used to form an impermeable barrier to prevent migration of c...

  18. Limnology of Taylor Creek impoundment : with reference to other bodies in Upper St Johns River Basin, Florida

    USGS Publications Warehouse

    Goolsby, D.A.; McPherson, Benjamin F.

    1978-01-01

    Taylor Creek Impoundment, on the western part of the upper St. Johns basin, Fla., provides flood control and flow regulation. The 4,000-acre impoundment was first filled in 1969. The water was of relatively poor quality during the first three years of its existence, 1970-72. The impoundment is deep enough for thermal stratification, and a thermocline usually develops at 8 to 10 feet. During 1970-72 the hypolimnion remained anaerobic for more than six months. The poor water quality is attributed to the decomposition of flooded vegetation, of soil organic matter, and to heavy growths of phytoplankton and duckweed stimulated by an abundant supply of nutrients. Since 1972, the quality of the water has improved because of flushing of the impoundment and depletion of leachable nutrients and soil organic matter. The water is now similar in quality to that of nearby Wolf and Jane Green Creeks. Large releases of water may produce velocities great enough to resuspend bottom sediments several miles downstream where Taylor Creek flows into Lake Poinsett. (Woodard-USGS)

  19. The use of artificial impoundments by two amphibian species in the Delaware Water Gap National Recreation Area

    USGS Publications Warehouse

    Julian, J.T.; Snyder, C.D.; Young, J.A.

    2006-01-01

    We compared breeding activity of Ambystoma maculatum (Spotted Salamander) and Rana sylvatica (Wood Frog) in artificial impoundments to patterns in natural wetlands over a three-year period in the Delaware Water Gap National Recreation Area. Rana sylvatica were 5.6 times more likely to use natural bodies of water for breeding than artificial impoundments, while A. maculatum were 2.7 times more likely to use natural bodies of water. Both species were approximately 9 times more likely to breed in fishless bodies of water than in waters with predatory fish. Ambystoma maculatum were 6 times more likely to breed in wetlands with more stable seasonal hydroperiods, while R. sylvatica were only 2 times more likely to do so. We conclude that the high likelihood of fish presence in impoundments was the primary explanation for why both species were less likely to use impoundments than natural wetlands, while the tendency of A. maculatum to avoid natural wetlands with shorter hydroperiods explained why differences in use between pond types was more pronounced for R. sylvatica.

  20. 40 CFR 63.134 - Process wastewater provisions-surface impoundments.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...) The control device shall be designed, operated, and inspected in accordance with § 63.139 of this... treats a Group 1 wastewater stream or a residual removed from a Group 1 wastewater stream, the owner or... pollutants vapors vented from the surface impoundment to a control device in accordance with paragraph (b)(1...

  1. 40 CFR 63.134 - Process wastewater provisions-surface impoundments.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...) The control device shall be designed, operated, and inspected in accordance with § 63.139 of this... treats a Group 1 wastewater stream or a residual removed from a Group 1 wastewater stream, the owner or... pollutants vapors vented from the surface impoundment to a control device in accordance with paragraph (b)(1...

  2. 40 CFR 63.134 - Process wastewater provisions-surface impoundments.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...) The control device shall be designed, operated, and inspected in accordance with § 63.139 of this... treats a Group 1 wastewater stream or a residual removed from a Group 1 wastewater stream, the owner or... pollutants vapors vented from the surface impoundment to a control device in accordance with paragraph (b)(1...

  3. 40 CFR 63.134 - Process wastewater provisions-surface impoundments.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...) The control device shall be designed, operated, and inspected in accordance with § 63.139 of this... treats a Group 1 wastewater stream or a residual removed from a Group 1 wastewater stream, the owner or... pollutants vapors vented from the surface impoundment to a control device in accordance with paragraph (b)(1...

  4. The Impact of Impoundment on Mercury Bioaccumulation in Fish Downstream from a Newly Constructed Reservoir, Wujiang River, Southwest China.

    PubMed

    Li, Sixin; Zhou, Lianfeng; Chang, Jianbo; Yang, Zhi; Hu, Juxiang; Hongjun, Wang

    2017-11-01

    Mercury concentrations in fish were investigated downstream from a newly impounded subtropical reservoir in August 2008. After 6-7 months of reservoir impoundment, mean mercury concentration in fish from downstream is significantly increased by 1.9 times. Not only carnivorous fish but also benthic fish had significantly higher total mercury concentrations than others. No significant correlation was found between total mercury concentrations and body length or weight of 13 fish species. Compared with the pre-impoundment, total mercury in fish from downstream is significantly increased by reservoir impoundment, but the increased rate is lower than those in subarctic and temperate areas. Fish samples surpassed the Chinese hygienic standard for tolerances of mercury in foods increased by 4.3%. More attention should be given to fish mercury levels from downstream sites to prevent possible adverse effects on the health of local people.

  5. Geochemistry of leachates from the El Fraile sulfide tailings piles in Taxco, Guerrero, southern Mexico.

    PubMed

    Talavera Mendoza, Oscar; Armienta Hernández, Ma Aurora; Abundis, José García; Mundo, Nestor Flores

    2006-06-01

    Leachates from the El Fraile tailings impoundment (Taxco, Mexico) were monitored every 2 months from October 2001 to August 2002 to assess the geochemical characteristics. These leachates are of interest because they are sometimes used as alternative sources of domestic water. Alternatively, they drain into the Cacalotenango creek and may represent a major source of metal contamination of surface water and sediments. Most El Fraile leachates show characteristics of Ca-SO(4), (Ca+Mg)-SO(4), Mg-SO(4 )and Ca-(SO(4)+HCO(3)) water types and are near-neutral (pH=6.3-7.7). Some acid leachates are generated by the interaction of meteoric water with tailings during rainfall events (pH=2.4-2.5). These contain variable levels of SO(4) (2-) (280-29,500 mg l(-1)) and As (<0.01-12.0 mg l(-1)) as well as Fe (0.025-2,352 mg l(-1)), Mn (0.1-732 mg l(-1)), Zn (<0.025-1465 mg l(-1)) and Pb (<0.01-0.351 mg l(-1)). Most samples show the highest metal enrichment during the dry seasons. Leachates used as domestic water typically exceed the Mexican Drinking Water Guidelines for sulfate, hardness, Fe, Mn, Pb and As, while acidic leachates exceed the Mexican Guidelines for Industrial Discharge Waters for pH, Cu, Cd and As. Speciation shows that in near-neutral solutions, metals exist mainly as free ions, sulfates and bicarbonates, while in acidic leachates they are present as sulfates and free ions. Arsenic appears as As((V)) in all samples. Thermodynamic and mineralogical evidence indicates that precipitation of Fe oxides and oxyhydroxides, clay minerals and jarosite as well as sorption by these minerals are the main processes controlling leachate chemistry. These processes occur mainly after neutralization by interaction with bedrock and equilibration with atmospheric oxygen.

  6. Colorado aqueduct system begins at impounded waters from Hoover Dam ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Colorado aqueduct system begins at impounded waters from Hoover Dam along with agreement made reserving use and ownership of several generators set to power pump houses downstream at Whitsett and beyond - Hoover Dam, Spanning Colorado River at Route 93, Boulder City, Clark County, NV

  7. The Role of Anionogenic Elements (As, Sb, Mo, Se, S, P, N, Cl, F, C) In The Formation of Technogenic Geochemical Anomalies

    NASA Astrophysics Data System (ADS)

    Abrosimova, Natalya; Bortnikova, Svetlana

    2017-12-01

    The study was conducted on the example of sulphide-containing mine tailings with a varying amount of sulphide and arsenide minerals, from three distinct tailings dumps situated in Russia: Karabash Mine Site, South Ural; Komsomolsk tailings impoundment, Kemerovo region; Khovu-Aksy mine site, Tuva Republic. The aim of the study was to compare the mobility of anionogenic elements (As, Sb, Mo, Se, S, P, N, Cl, F, C) and their role in migration, precipitation, and concentration of metals during the water-tailings interaction depending on the physicochemical parameters (pH, Eh) of the medium and the mineral composition of the waste material. Using slightly acidic leaching experiments the quantitative estimation of mobile forms of elements is given. Based on the compositions of the obtained water leaching solutions, aqueous speciation of chemical elements and saturation index of key minerals in the experimental solutions were calculated. The results of calculating forms of chemical elements made it possible to construct series of mobility of metals and metalloids in solutions with different physicochemical parameters. In the alkaline conditions, Sb>As>Cd>Cu>Zn>Fe>Pb, when the medium is acidified, the series changes, As>Cd>Cu>Zn>Pb>Sb>Fe in weakly alkaline conditions, Sb>Mn>As>Zn>Fe however, when the medium is acidified, the series changes to Cd>Mn>Pb>Cu>Zn>Sb>Ni>Fe>As under acidic conditions Cd>Cu>Zn>Pb>Mn>Fe>Se>Mo>Sb>As>Ni. The mineral composition of the tailings was investigated, which will allow to determine the sources of toxic elements and to understand the processes of secondary mineral formation in technogenic objects. Arsenopyrite and pyrite predominate in the heavy fraction of the Komsomolsk tailings impoundment, arsenopyrite grains are often corroded, Sb contained in Sb oxide and Sb sulfide. The pyrite and barite are determined in the solid matter of the Karabash Mine Site and chalcopyrite, sphalerite, tennantite Cu3AsS3, and tetrahedrite (Cu,Fe)12Sb4S13 are

  8. An examination of Washington State's vehicle impoundment law for motorcycle endorsements.

    DOT National Transportation Integrated Search

    2013-01-01

    In July 2007, Washington State modified its vehicle code to expressly allow law enforcement officers : to impound motorcycles of motorcyclists operating without a proper motorcycle endorsement on their : licenses. The objective for this study was to ...

  9. The role of impoundments in the sediment budget of the conterminous United States

    USGS Publications Warehouse

    Renwick, W.H.; Smith, S.V.; Bartley, J.D.; Buddemeier, R.W.

    2005-01-01

    Previous work on sediment budgets for U.S. agricultural regions has concluded that most sediment derived from accelerated erosion is still on the landscape, primarily in colluvial and alluvial deposits. Here we examine the role of small impoundments in the subcontinental sediment budget. A recent inventory based on a 30-m satellite imagery reveals approximately 2.6 million ponds, while extrapolation from a sample of 1:24,000 topographic quadrangles suggests the total may be as large as 8-9 million. These ponds capture an estimated 21% of the total drainage area of the conterminous U.S., representing 25% of total sheet and rill erosion. We estimate the total sedimentation in these small impoundments using three different methods; these estimates range from 0.43 to 1.78 ?? 109 m3 yr-1. Total sedimentation in ???43,000 reservoirs from the National Inventory of Dams is estimated at 1.67 ?? 109 m3 yr-1. Total USLE erosion in 1992 was 2.4 ?? 109 m3 yr-1, and export to coastal areas is estimated at 0.6 ?? 109 m3 yr-1. Total sedimentation in impoundments is large in relation to upland erosion, in apparent contradiction to previous studies that have identified colluvial and alluvial deposition as the primary sinks. Several alternative hypotheses that could help explain this result are proposed. Regardless of which of these alternatives may prove to be the most significant in any given setting, it is clear that most sedimentation is now taking place in subaqueous rather than subaerial environments, and that small impoundments are a major sediment sink. ?? 2005 Elsevier B.V. All rights reserved.

  10. Effects of river impoundment on ecosystem services of large tropical rivers: embodied energy and market value of artisanal fisheries.

    PubMed

    Hoeinghaus, David J; Agostinho, Angelo A; Gomes, Luiz C; Pelicice, Fernando M; Okada, Edson K; Latini, João D; Kashiwaqui, Elaine A L; Winemiller, Kirk O

    2009-10-01

    Applying the ecosystem services concept to conservation initiatives or in managing ecosystem services requires understanding how environmental impacts affect the ecology of key species or functional groups providing the services. We examined effects of river impoundments, one of the leading threats to freshwater biodiversity, on an important ecosystem service provided by large tropical rivers (i.e., artisanal fisheries). The societal and economic importance of this ecosystem service in developing countries may provide leverage to advance conservation agendas where future impoundments are being considered. We assessed impoundment effects on the energetic costs of fisheries production (embodied energy) and commercial market value of the artisanal fishery of the Paraná River, Brazil, before and after formation of Itaipu Reservoir. High-value migratory species that dominated the fishery before the impoundment was built constituted a minor component of the contemporary fishery that is based heavily on reservoir-adapted introduced species. Cascading effects of river impoundment resulted in a mismatch between embodied energy and market value: energetic costs of fisheries production increased, whereas market value decreased. This was partially attributable to changes in species functional composition but also strongly linked to species identities that affected market value as a result of consumer preferences even when species were functionally similar. Similar trends are expected in other large tropical rivers following impoundment. In addition to identifying consequences of a common anthropogenic impact on an important ecosystem service, our assessment provides insight into the sustainability of fisheries production in tropical rivers and priorities for regional biodiversity conservation.

  11. Acidity of Lakes and Impoundments in North-Central Minnesota

    Treesearch

    Elon S. Verry

    1981-01-01

    Measurements of lake and impoundment pH for several years, intensive sampling within years, and pH-calcium plots verify normal pH levels and do not show evidence of changes due to acid precipitation. These data in comparison with general lake data narrow the northern Lake States area in which rain or snow may cause lake acidification.

  12. Microdam Impoundments Provide Suitable Habitat for Larvae of Malaria Vectors: An Observational Study in Western Kenya.

    PubMed

    McCann, Robert S; Gimnig, John E; Bayoh, M Nabie; Ombok, Maurice; Walker, Edward D

    2018-05-04

    Impoundments formed by microdams in rural areas of Africa are important sources of water for people, but they provide potential larval habitats for Anopheles (Diptera: Culicidae) mosquitoes that are vectors of malaria. To study this association, the perimeters of 31 microdam impoundments in western Kenya were sampled for Anopheles larvae in three zones (patches of floating and emergent vegetation, shorelines of open water, and aggregations of cattle hoofprints) across dry and rainy seasons. Of 3,169 larvae collected, most (86.8%) were collected in the rainy season. Of 2,403 larvae successfully reared to fourth instar or adult, nine species were identified; most (80.2%) were Anopheles arabiensis Patton, sampled from hoofprint zones in the rainy season. Other species collected were Anopheles coustani Laveran, Anopheles gambiae s.s. Giles, Anopheles funestus Giles, and Anopheles rivulorum Leeson, Anopheles pharoensis Theobald, Anopheles squamosus Theobald, Anopheles rufipes (Gough), and Anopheles ardensis (Theobald). Larvae of An. funestus were uncommon (1.5%) in both dry and rainy seasons and were confined to vegetated zones, suggesting that microdam impoundments are not primary habitats for this important vector species, although microdams may provide a dry season refuge habitat for malaria vectors, contributing to population persistence through the dry season. In this study, microdam impoundments clearly provided habitat for the malaria vector An. arabiensis in the rainy season, most of which was within the shallow apron side of the impoundments where people brought cattle for watering, resulting in compacted soil with aggregations of water-filled hoofprints. This observation suggests a potential conflict between public health concerns about malaria and people's need for stable and reliable sources of water.

  13. Studies of the phytoplankton and soil algae of two strip-mine impoundments in Tuscarawas County, Ohio

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Richards, J.N.

    1973-01-01

    The process of strip-mining leaves vast areas that are denuded of vegetation and are open to primary succession by organisms such as algae. Acid strip-mine impoundments are either formed by man-made or natural processes. These impoundments are remnants of old strip-mine pits that have been filled with runoff water. The water chemistry of these ponds reflects the chemistry of the earth strata above the coal seam that was mined. These young impoundments or ponds are extremely low in pH and quite acidic due to the presence of great amounts of sulfuric acid. Algae that are found in these types ofmore » habitats exhibit a tolerance to acid conditions and are considered to be acidophilic. Few species of algae are known to be common componenets of these habitats.« less

  14. Mosquito production in a rotationally managed impoundment compared to other management techniques.

    PubMed

    Carlson, D B; O'Bryan, P D

    1988-06-01

    Mosquito production was monitored by larval dipping for 12 months in a 20.2 ha central east coast Florida salt marsh impoundment which was being managed under a rotational impoundment management (RIM) regime. This regime, implemented to provide mosquito control while retaining natural resource benefits, virtually eliminated salt-marsh Aedes mosquito production from late May through September when the marsh was closed to the estuary and flooded to approximately 1.0 ft NGVD. Anopheles spp. were collected only along the upland marsh edges in relatively low densities. Compared with the management methods of: 1) open to the estuary with culverts and, 2) passive retention of water with flapgate risers, RIM proved to be significantly more effective in reducing mosquito production.

  15. 40 CFR 63.942 - Standards-Surface impoundment floating membrane cover.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... seams or between the interface of the cover edge and its foundation mountings. (4) Except as provided...: organic vapor permeability; the effects of any contact with the liquid and its vapor managed in the surface impoundment; the effects of outdoor exposure to wind, moisture, and sunlight; and the operating...

  16. 40 CFR 63.942 - Standards-Surface impoundment floating membrane cover.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... seams or between the interface of the cover edge and its foundation mountings. (4) Except as provided...: organic vapor permeability; the effects of any contact with the liquid and its vapor managed in the surface impoundment; the effects of outdoor exposure to wind, moisture, and sunlight; and the operating...

  17. 40 CFR 63.942 - Standards-Surface impoundment floating membrane cover.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... seams or between the interface of the cover edge and its foundation mountings. (4) Except as provided...: organic vapor permeability; the effects of any contact with the liquid and its vapor managed in the surface impoundment; the effects of outdoor exposure to wind, moisture, and sunlight; and the operating...

  18. 40 CFR 63.942 - Standards-Surface impoundment floating membrane cover.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... seams or between the interface of the cover edge and its foundation mountings. (4) Except as provided...: organic vapor permeability; the effects of any contact with the liquid and its vapor managed in the surface impoundment; the effects of outdoor exposure to wind, moisture, and sunlight; and the operating...

  19. 40 CFR 63.942 - Standards-Surface impoundment floating membrane cover.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... seams or between the interface of the cover edge and its foundation mountings. (4) Except as provided...: organic vapor permeability; the effects of any contact with the liquid and its vapor managed in the surface impoundment; the effects of outdoor exposure to wind, moisture, and sunlight; and the operating...

  20. Heavy-tailed fractional Pearson diffusions.

    PubMed

    Leonenko, N N; Papić, I; Sikorskii, A; Šuvak, N

    2017-11-01

    We define heavy-tailed fractional reciprocal gamma and Fisher-Snedecor diffusions by a non-Markovian time change in the corresponding Pearson diffusions. Pearson diffusions are governed by the backward Kolmogorov equations with space-varying polynomial coefficients and are widely used in applications. The corresponding fractional reciprocal gamma and Fisher-Snedecor diffusions are governed by the fractional backward Kolmogorov equations and have heavy-tailed marginal distributions in the steady state. We derive the explicit expressions for the transition densities of the fractional reciprocal gamma and Fisher-Snedecor diffusions and strong solutions of the associated Cauchy problems for the fractional backward Kolmogorov equation.

  1. Sol-gel transition behavior of aqueous peptide-amphiphile (C16-W3K) solutions: effects of alkyl-tail length, mechanical shear, temperature, and salt

    NASA Astrophysics Data System (ADS)

    Yamamoto, Masashi; Otsuka, Takahiro; Orimo, Yoshinori; Maeda, Tomoki; Hotta, Atsushi

    Peptide amphiphiles (PA) possess nanoscale micelle structures and excellent biocompatibility. In aqueous PA solution, PA molecules can self-assemble through various configurations into spherical and wormlike micelles, which can occasionally form hydrogels. C16-W3K is one of the unique PA, whose micelle configurations can transfer from spherical to wormlike structures in its aqueous solution over time, while the wormlike micelles could also lead to gelation. In our recent research, the effects of the length of the hydrophobic alkyl tail and other external factors of C16-W3K on the gelation behavior of the C16-W3K solution have been discussed. It has been revealed that longer alkyl-tails could facilitate the gelation of the C16-W3K solution, and that the external stimuli, such as mechanical shear and heat, could promote faster gelation of the C16-W3K solution. It was also found that salt could adjust the pH of the C16-W3K solution, having profound influence on the gelation behavior of the C16-W3K solution. In fact, the gelation of the C16-W3K with a higher storage modulus could be obtained from relatively acidic solutions, while the gelation of the C16-W3K solution was firmly suppressed in highly basic solutions. This work was supported by a Grant-in-Aid for Scientific Research (A) (No. 15H02298 to A.H.) and a Grant-in-Aid for Research Activity Start-up (No.15H06586 to T.M.) from JSPS: KAKENHI.

  2. 25 CFR 161.708 - How are trespassers notified of impoundments?

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... PARTITIONED LANDS GRAZING PERMITS Trespass Actions § 161.708 How are trespassers notified of impoundments? (a) If the trespass is not corrected in the time specified in the initial trespass notice, BIA will send... published in the local newspaper nearest to the Indian agricultural lands where the trespass is occurring...

  3. 25 CFR 161.708 - How are trespassers notified of impoundments?

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... PARTITIONED LANDS GRAZING PERMITS Trespass Actions § 161.708 How are trespassers notified of impoundments? (a) If the trespass is not corrected in the time specified in the initial trespass notice, BIA will send... published in the local newspaper nearest to the Indian agricultural lands where the trespass is occurring...

  4. 25 CFR 161.708 - How are trespassers notified of impoundments?

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... PARTITIONED LANDS GRAZING PERMITS Trespass Actions § 161.708 How are trespassers notified of impoundments? (a) If the trespass is not corrected in the time specified in the initial trespass notice, BIA will send... published in the local newspaper nearest to the Indian agricultural lands where the trespass is occurring...

  5. 25 CFR 161.708 - How are trespassers notified of impoundments?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... PARTITIONED LANDS GRAZING PERMITS Trespass Actions § 161.708 How are trespassers notified of impoundments? (a) If the trespass is not corrected in the time specified in the initial trespass notice, BIA will send... published in the local newspaper nearest to the Indian agricultural lands where the trespass is occurring...

  6. 25 CFR 161.708 - How are trespassers notified of impoundments?

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... PARTITIONED LANDS GRAZING PERMITS Trespass Actions § 161.708 How are trespassers notified of impoundments? (a) If the trespass is not corrected in the time specified in the initial trespass notice, BIA will send... published in the local newspaper nearest to the Indian agricultural lands where the trespass is occurring...

  7. 25 CFR 168.16 - Impoundment and disposal of unauthorized livestock.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... of Intent to Impound unauthorized livestock is first published in the local newspaper, posted at the nearest chapter house, and in one or more local trading posts. (c) Unauthorized livestock on the Hopi... unauthorized livestock in areas for which a notice has been posted and published under paragraph (b) of this...

  8. 25 CFR 168.16 - Impoundment and disposal of unauthorized livestock.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... of Intent to Impound unauthorized livestock is first published in the local newspaper, posted at the nearest chapter house, and in one or more local trading posts. (c) Unauthorized livestock on the Hopi... unauthorized livestock in areas for which a notice has been posted and published under paragraph (b) of this...

  9. 1. BUNKER HILL LEAD SMELTER. VIEW IS FROM CENTRAL IMPOUNDMENT ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. BUNKER HILL LEAD SMELTER. VIEW IS FROM CENTRAL IMPOUNDMENT AREA LOOKING SOUTH. PLANT DRY IS IN CENTER FOREGROUND, SLAG FUMING PLANT IS IN RIGHT FOREGROUND, AND BAG HOUSE IS IN RIGHT BACKGROUND. VARIOUS PLANT STACKS ARE ALSO VISIBLE. - Bunker Hill Lead Smelter, Bradley Rail Siding, Kellogg, Shoshone County, ID

  10. 25 CFR 700.727 - Impoundment and disposal of unauthorized livestock.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... of Intent to Impound Unauthorized Livestock is first published in a local newspaper, posted at the nearest chapter house, and in one or more local trading posts. (c) Unauthorized livestock on the New Lands... livestock in areas for which notice has been posted and published under paragraph (b) of this section, will...

  11. 25 CFR 700.727 - Impoundment and disposal of unauthorized livestock.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... of Intent to Impound Unauthorized Livestock is first published in a local newspaper, posted at the nearest chapter house, and in one or more local trading posts. (c) Unauthorized livestock on the New Lands... livestock in areas for which notice has been posted and published under paragraph (b) of this section, will...

  12. Nutrient fluxes and stoichiometry in a large impounded river-bay system

    NASA Astrophysics Data System (ADS)

    Klump, J. V.; Waples, J. T.; Able, L. M.; Anderson, P. D.; Weckerly, K.; Szmania, D. C.

    2003-04-01

    Reservoir-induced aging of continental runoff has been shown to an anthropogenically induced global phenomenon with estimates that the mean age of river water reaching the coastal ocean has likely tripled historically. This aging is hypothesized to have a significant biogeochemical impact on land-margin systems by altering flow regimes, net water balances and residence times, reaeration of surface waters, carbon cycling processes, and sediment storage and transport. The Fox-Wolf watershed system contains more than 20 reservoirs, impoundments and lakes on the main stems of the two principal rivers that feed Green Bay and Lake Michigan. Consequently, this hydrologic system can be conceived as functioning as a series of linked biogeochemical reactors which retard flow, retain particles, significantly attenuate the flux of materials into sequential downstream "pools", and both process and repackage nutrients via tightly coupled benthic-pelagic biotic interactions. This successional transformation process results in a poorly understood delivery of nutrients, soils and contaminants from upstream sources to downstream receptors in Green Bay and ultimately -- Lake Michigan. Nutrient reprocessing (defined as the sum of all processes affecting nutrients, i.e. fixation, remineralization, repackaging, sedimentation, etc.) within each pool is hypothesized to be primarily a function of: (1) particle-solute and hydraulic residence times, (2) the quality and quantity of inputs, and (3) the food web structure. Overlaid on these dynamics are very strong seasonal forcing factors, including annual temperature cycles that induce order of magnitude variations in temperature dependent reaction rates, and winter ice cover on the upper pool lakes, reservoirs and Green Bay, that halts run off from the land and reduces within-basin mixing. These short term and seasonal loading dynamics result in considerable temporal stochasticity in the capacity of the biotic component of the ecosystem to

  13. Magnetite recovery from copper tailings increases arsenic distribution in solution phase and uptake in native grass.

    PubMed

    Liu, Yunjia; Huang, Longbin

    2017-01-15

    Reprocessing magnetite-rich copper (Cu) tailings prompted a concern about arsenic (As) risks in seepage water and revegetated plants at Ernest Henry Cu Mine (EHM) in North Queensland, Australia, due to the closely coupled relationship between iron (Fe) minerals and As mobility. The magnetite removal alone significantly decreased the content of crystalline Fe minerals and the maximum arsenate (As(V)) sorption capacity of the resultant tailings. A glasshouse experiment with native grass Red Flinders (Iseilema Vaginiflorum) was conducted with the reprocessed (low magnetite (LM)) and original (high magnetite (HM)) tailings, which were amended with 5% sugarcane residue (SR) as a basal treatment in combination with 0, 1 and 5% pine-biochar (BC). The organic matter treatments and plant growth stimulated the formation of secondary Fe minerals. The amount of extractable amorphous Fe in the amended and revegetated HM tailings was significantly higher than those in the LM. Arsenic forms in the specifically sorbed and the sorbed by amorphous Fe oxides were significantly increased by the SR amendment in the LM tailings, but which were decreased in the HM, compared to the unamended tailings. Soluble As levels in the porewater of the LM under revegetation were significantly higher (300-1150 μg As L -1 ) than those (up to 45-90 μg As L -1 ) in HM tailings in the same treatment, which led to the higher As concentrations in the plants grown in the LM tailings. In particular, root As concentration (62-146 mg kg -1 ) in the LM tailings was almost a magnitude higher than those (8-17 mg kg -1 ) in the HM. The present results confirmed the initial expectation that the recovery of magnetite from the Cu tailings significantly elevated the risk of As solubility in the tailings by decreasing As sorption capacity and increasing soluble As levels. Thus, it would be beneficial to retain high contents of magnetite in the top layer (e.g., root zone) of the Cu tailings for managing As

  14. Riverbed-Sediment Mapping in the Edwards Dam Impoundment on the Kennebec River, Maine By Use of Geophysical Techniques

    USGS Publications Warehouse

    Dudley, Robert W.

    1999-01-01

    INTRODUCTION In July 1997, the Federal Energy Regulatory Commission (FERC) issued a Final Environmental Impact Statement recommending that the 162-year-old Edwards Dam on the Kennebec River in Augusta, Maine, be removed. The impoundment formed by Edwards Dam extends about 15 mi to the city of Waterville, near the confluence of the Sebasticook River with the Kennebec River. The impoundment has a surface area of 1,143 acres, a gross storage of approximately 740 million ft3, and a usable storage of about 184 million ft3 (Stone and Webster, 1995a). According to FERC, removal of the 917-ft-long, 24-ft-high timber crib and concrete structure would restore 15 mi of riverine habitat, improve passage of ocean-migrating fish species native to the Kennebec River, and result in substantial recreational enhancements (Federal Energy Regulatory Commission, 1997). Because the removal of Edwards Dam would change the hydraulic characteristics of the river in the present-day impoundment, the potential transport of erodible, fine-grained sediment currently in the impoundment is a concern. Of particular concern is the erosion and transport of this sediment to areas downstream from the dam, a process that could introduce possible bacterial and chemical contamination and could impede river navigation as a result of sediment deposition. In an effort to build upon available information on the composition of the riverbed, the U.S. Geological Survey (USGS), in cooperation with the Maine State Planning Office, classified riverbed sediment types and mapped their areal extents in the lower (southern) half of the Edwards Dam impoundment. This report describes the methods used to collect and analyze the data used to create a map of sediment types in the Edwards Dam impoundment. The map is included with this report. Data used to map riverbed sediment types were also used to estimate the volume of observed mud and mud-containing sediment in the study area.

  15. 30 CFR 717.18 - Dams constructed of or impounding waste material.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... freeboard distance between the lowest point on the embankment crest and the maximum water elevation shall be... volume of water stored during the design precipitation event within 10 days. (viii) During construction... waters over the past year, existing storage capacity of impounding structures, any fires occurring in the...

  16. The X-ray Crystal Structure of the Phage Tail Terminator Protein Reveals the Biologically Relevant Hexameric Rang Structure and Demonstrates a Conserved mechanism of Tail Termination among Divrse Long Tailed Phages

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Pell, L.; Liu, A; Edmonds, L

    The tail terminator protein (TrP) plays an essential role in phage tail assembly by capping the rapidly polymerizing tail once it has reached its requisite length and serving as the interaction surface for phage heads. Here, we present the 2.7-A crystal structure of a hexameric ring of gpU, the TrP of phage ?. Using sequence alignment analysis and site-directed mutagenesis, we have shown that this multimeric structure is biologically relevant and we have delineated its functional surfaces. Comparison of the hexameric crystal structure with the solution structure of gpU that we previously solved using NMR spectroscopy shows large structural changesmore » occurring upon multimerization and suggests a mechanism that allows gpU to remain monomeric at high concentrations on its own, yet polymerize readily upon contact with an assembled tail tube. The gpU hexamer displays several flexible loops that play key roles in head and tail binding, implying a role for disorder-to-order transitions in controlling assembly as has been observed with other ? morphogenetic proteins. Finally, we have found that the hexameric structure of gpU is very similar to the structure of a putative TrP from a contractile phage tail even though it displays no detectable sequence similarity. This finding coupled with further bioinformatic investigations has led us to conclude that the TrPs of non-contractile-tailed phages, such as ?, are evolutionarily related to those of contractile-tailed phages, such as P2 and Mu, and that all long-tailed phages may utilize a conserved mechanism for tail termination.« less

  17. Analysis of Wading Bird use of Impounded Wetland Habitat on the Kennedy Space Center/Merritt Island National Wildlife Refuge, 1987-1998

    NASA Technical Reports Server (NTRS)

    Stolen, Eric D.; Breininger, David R.; Smith, Rebecca B.; Quincy, Charlie (Technical Monitor)

    2002-01-01

    This report summarizes results of the first eleven years of monthly aerial surveys of wading bird use of foraging habitats within impoundments on the Kennedy Space Center/Merritt Island National Wildlife Refuge. Some impoundments were used much more heavily by wading birds than were others. Analysis suggests that an increase in interspersion of open water and vegetated habitats is preferred foraging habitat. Many wading bird species increased their use of vegetated habitat in Fall and Winter when impoundments were flooded. The mean number of wading birds per survey was greatest during the Pre-nesting and Nesting seasons, declined during Post-nesting season, and was lowest during Winter when water levels within impoundments were high. During these times, shallow habitat along the IRL shoreline provided alternative habitats for wading birds. Various measures of monthly precipitation and impoundment water level were well correlated with the numbers of wading birds observed. Numbers of nesting attempts was steady during the study period, with the exception of an unusually high number of attempts in 1990. White Ibis accounted for over half of all wading bird nests counted. The mean number of nests per colony decreased during the study period, and the number of individual colonies increased.

  18. DOCUMENTING THE U.S. LANDFILL/IMPOUNDMENT PERMIT: A GUIDE TO TECHNICAL RESOURCES

    EPA Science Inventory

    Since 1976, beginning with the Resource Conservation and Recovery Act (RCRA), the United States government has legislated standards for landfills and surface impoundments to make certain that when disposing of hazardous wstes, human health and the environment will be protected. ...

  19. Plant/soil concentration ratios of SSWRa for contrasting sites around an active U mine-mill

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Ibrahim, S.A.; Whicker, F.W.

    Concentrations of 226Ra were determined in native vegetation and underlying substrate (soil and tailings) at various sites around a conventional open-pit, acid leach U production operation in Wyoming. Plant/soil concentration ratios (CRs) for 226Ra were estimated for various sites, including weathered tailings; a tailings impoundment shoreline; downwind from exposed tailings; a mine overburden reclamation area; and several background locations. Radium-226 concentrations for vegetation and substrate and CR values from the perturbed sites were elevated above background. The highest vegetation concentration (1.3 Bq g-1) was found in a grass which had invaded exposed, weathered tailings. Levels of 226Ra in soil andmore » vegetation and CR values decreased with distance from the tailings impoundment edge. CR values varied significantly among sites, but few differences were found between plant species groups. The observed CR values ranged from 0.07 at the background and reclamation areas to 0.4 downwind from the tailings area. Average CR values for plants growing on exposed tailings and within one meter from the impoundment edge were 0.15 and 0.3, respectively. CR values of 226Ra for plants on tailings substrates were comparatively low in contrast to other radionuclides in the U chain. We speculate that in the case of sulfuric acid leached tailings-derived material, 226Ra is sequestered as sulfate, which is highly insoluble relative to the sulfates of the other elements (e.g., U and Th) resulting in reduced availability for plant uptake.« less

  20. Organochlorine pesticide levels in Clarias gariepinus from polluted freshwater impoundments in South Africa and associated human health risks.

    PubMed

    Barnhoorn, I E J; van Dyk, J C; Genthe, B; Harding, W R; Wagenaar, G M; Bornman, M S

    2015-02-01

    There are increasing concerns regarding the safe human consumption of fish from polluted, freshwater impoundments. The aim of this study was to analyse the muscle tissue of the sharptooth catfish Clarias gariepinus for selected organo-chlorine pesticides (OCPs) and to perform a human health risk assessment using a standard protocol described by the United States Environmental Protection Agency (US EPA). Fish were collected from the polluted Roodeplaat-(RDPD), Rietvlei-(RVD) and Hartbeespoort (HBPD) Dam impoundments located in the north-eastern regions of South Africa. GC-MS analyses showed levels of various OCPs in fish muscle samples from all three impoundments. For fish collected from the RDPD, p,p'-DDE, endosulfan, lindane and β- and δ-HCH were the most prevalent OCPs detected, while p,p'-DDE and endosulfan were the most predominant in fish from the RVD. Lindane and β- and δ-HCH were the main OCPs detected in fish from the HBPD. Dieldrin was the only OCP detected at concentrations for which a cancer risk and a hazard index above the acceptable risk levels were estimated. This was the case for fish from both the RDPD and RVD impoundments. No toxic risk was estimated should fish from the HBPD be consumed. Copyright © 2014 Elsevier Ltd. All rights reserved.

  1. 32 CFR 634.52 - Search incident to impoundment based on criminal activity.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    .... This situation could also arise during cases of intoxicated driving or traffic accidents in which the... (CONTINUED) LAW ENFORCEMENT AND CRIMINAL INVESTIGATIONS MOTOR VEHICLE TRAFFIC SUPERVISION Impounding... general situations: (a) The owner or operator is not present. This situation could arise during traffic...

  2. 30 CFR 715.18 - Dams constructed of or impounding waste material.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... point on the embankment crest and the maximum water elevation shall be at least 3 feet to avoid... facility to be evacuated by spillways or decants of 90 percent of the volume of water stored during the..., existing storage capacity of impounding structures, any fires occurring in the material over the past year...

  3. Recovery of Manganese Ore Tailings by High-Gradient Magnetic Separation and Hydrometallurgical Method

    NASA Astrophysics Data System (ADS)

    Zhang, Xiufeng; Tan, Xiumin; Yi, Yuejun; Liu, Weizao; Li, Chun

    2017-11-01

    With the depletion of high-grade manganese ores, Mn ore tailings are considered valuable secondary resources. In this study, a process combining high-gradient magnetic separation (HGMS) with hydrometallurgical methods is proposed to recycle fine-grained Mn tailings. The Mn tailings were treated by HGMS at 12,500 G to obtain a Mn concentrate of 30% Mn with the recovery efficiency of 64%. The Mn concentrate could be used in the ferromanganese industry. To recover Mn further, the nonmagnetic fraction was leached by SO2 in an H2SO4 solution. Hydrogen peroxide was added to the leachate to oxidize Fe2+ to Fe3+, and the solution pH was adjusted to 5.0-5.5 with ammonia to remove Al, Fe, and Si impurities. The purified solution was reacted with NH4HCO3, and a saleable product of MnCO3 with 97.9% purity was obtained. The combined process can be applied to Mn recovery from finely dispersed weakly magnetic Mn ores or tailings.

  4. Alternative waste residue materials for passive in situ prevention of sulfide-mine tailings oxidation: a field evaluation.

    PubMed

    Nason, Peter; Johnson, Raymond H; Neuschütz, Clara; Alakangas, Lena; Öhlander, Björn

    2014-02-28

    Novel solutions for sulfide-mine tailings remediation were evaluated in field-scale experiments on a former tailings repository in northern Sweden. Uncovered sulfide-tailings were compared to sewage-sludge biosolid amended tailings over 2 years. An application of a 0.2m single-layer sewage-sludge amendment was unsuccessful at preventing oxygen ingress to underlying tailings. It merely slowed the sulfide-oxidation rate by 20%. In addition, sludge-derived metals (Cu, Ni, Fe, and Zn) migrated and precipitated at the tailings-to-sludge interface. By using an additional 0.6m thick fly-ash sealing layer underlying the sewage sludge layer, a solution to mitigate oxygen transport to the underlying tailings and minimize sulfide-oxidation was found. The fly-ash acted as a hardened physical barrier that prevented oxygen diffusion and provided a trap for sludge-borne metals. Nevertheless, the biosolid application hampered the application, despite the advances in the effectiveness of the fly-ash layer, as sludge-borne nitrate leached through the cover system into the underlying tailings, oxidizing pyrite. This created a 0.3m deep oxidized zone in 6-years. This study highlights that using sewage sludge in unconventional cover systems is not always a practical solution for the remediation of sulfide-bearing mine tailings to mitigate against sulfide weathering and acid rock drainage formation. Copyright © 2014 Elsevier B.V. All rights reserved.

  5. Alternative waste residue materials for passive in situ prevention of sulfide-mine tailings oxidation: A field evaluation

    USGS Publications Warehouse

    Nason, Peter; Johnson, Raymond H.; Neuschutz, Clara; Alakangas, Lena; Ohlander, Bjorn

    2014-01-01

    Novel solutions for sulfide-mine tailings remediation were evaluated in field-scale experiments on a former tailings repository in northern Sweden. Uncovered sulfide-tailings were compared to sewage-sludge biosolid amended tailings over 2 years. An application of a 0.2 m single-layer sewage-sludge amendment was unsuccessful at preventing oxygen ingress to underlying tailings. It merely slowed the sulfide-oxidation rate by 20%. In addition, sludge-derived metals (Cu, Ni, Fe, and Zn) migrated and precipitated at the tailings-to-sludge interface. By using an additional 0.6 m thick fly-ash sealing layer underlying the sewage sludge layer, a solution to mitigate oxygen transport to the underlying tailings and minimize sulfide-oxidation was found. The fly-ash acted as a hardened physical barrier that prevented oxygen diffusion and provided a trap for sludge-borne metals. Nevertheless, the biosolid application hampered the application, despite the advances in the effectiveness of the fly-ash layer, as sludge-borne nitrate leached through the cover system into the underlying tailings, oxidizing pyrite. This created a 0.3 m deep oxidized zone in 6-years. This study highlights that using sewage sludge in unconventional cover systems is not always a practical solution for the remediation of sulfide-bearing mine tailings to mitigate against sulfide weathering and acid rock drainage formation.

  6. [Influence of 175-m-impoundment in Three Gorges Reservoir area on the food web energy sources of main commercial fishes in backwater area of xiaojiang River].

    PubMed

    Li, Bin; Wang, Zhi-Jian; Yue, Xing-Jian; Wang, Yong-Ming; Jin, Li; Zhang, Yao-Guang

    2013-06-01

    The impoundment in the Three Gorges Reservoir Area (TGRA) was first reached 175 m in 2010. To approach the influence of this impoundment on the food web energy sources of fishes in the tributaries of TRGA, an analysis was made on the food web energy sources of seven economically important fishes (Carassius auratus, Cyprinus carpio, Silurus asotus, Culter mongolicus mongolicus, Mystus macropterus, Pelteobagrus vachelli, and Pelteobagrus nitidus) in the backwater area of Xiaojiang River by using stable isotope method in combining with IsoSource Model. The results showed that before this impoundment (July 2010), microalgae were the main energy sources for the seven species. After this impoundment (December 2010), the contribution ratio of the microalgae decreased somewhat, while the relative contribution of terrestrial C4 plants had an obvious increase. Especially for crucian carp (C. auratus) and catfish (S. asotus), the contribution rate of the C4 plants reached 38-54% and 32-50%, respectively. After the impoundment, at least 30% of the energy resources of these two fishes were come from terrestrial C4 plants, suggesting that the impoundment in TGRA increased the contribution rate of exogenous terrestrial C4 plants as the energy sources of fishes.

  7. 40 CFR 270.17 - Specific part B information requirements for surface impoundments.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... double liner and leak (leachate) detection, collection, and removal system, if the surface impoundment... double liners and a leak detection, collection, and removal system or alternative design is sought as... detection system is located in a saturated zone, submit detailed plans and an engineering report explaining...

  8. Rapid oxidation of sulfide mine tailings by reaction with potassium ferrate.

    PubMed

    Murshed, Mohamed; Rockstraw, David A; Hanson, Adrian T; Johnson, Michael

    2003-01-01

    The chemistry of sulfide mine tailings treated with potassium ferrate (K2FeO4) in aqueous slurry has been investigated. The reaction system is believed to parallel a geochemical oxidation in which ferrate ion replaces oxygen. This chemical system utilized in a pipeline (as a plug flow reactor) may have application eliminating the potential for tailings to leach acid while recovering the metal from the tailings. Elemental analyses were performed using an ICP spectrometer for the aqueous phase extract of the treated tailings; and an SEM-EDX for the tailing solids. Solids were analyzed before and after treatments were applied. ICP shows that as the mass ratio of ferrate ion to tailings increases, the concentration of metals in the extract solution increases; while EDX indicates a corresponding decrease in sulfur content of the tailing solids. The extraction of metal and reduction in sulfide content is significant. The kinetic timeframe is on the order of minutes.

  9. Restoration of Tidal Flow to Impounded Salt Marsh Exerts Mixed Effect on Leaf Litter Decomposition

    NASA Astrophysics Data System (ADS)

    Henry, B. A.; Schade, J. D.; Foreman, K.

    2015-12-01

    Salt marsh impoundments (e.g. roads, levees) disconnect marshes from ocean tides, which impairs ecosystem services and often promotes invasive species. Numerous restoration projects now focus on removing impoundments. Leaf litter decomposition is a central process in salt marsh carbon and nutrient cycles, and this study investigated the extent to which marsh restoration alters litter decomposition rates. We considered three environmental factors that can potentially change during restoration: salinity, tidal regime, and dominant plant species. A one-month field experiment (Cape Cod, MA) measured decay of litter bags in impounded, restored, and natural marshes under ambient conditions. A two-week lab experiment measured litter decay in controlled incubations under experimental treatments for salinity (1ppt and 30 ppt), tidal regime (inundated and 12 hr wet-dry cycles), and plant species (native Spartina alterniflora and invasive Phragmites australis). S. alterniflora decomposed faster in situ than P. australis (14±1.0% mass loss versus 0.74±0.69%). Corroborating this difference in decomposition, S. alterniflora supported greater microbial respiration during lab incubation, measured as CO2 flux from leaf litter and biological oxygen demand of water containing leached organic matter (OM). However, nutrient analysis of plant tissue and leached OM show P. australis released more nitrogen than S. alterniflora. Low salinity treatments in both lab and field experiments decayed more rapidly than high salinity treatments, suggesting that salinity inhibited microbial activity. Manipulation of inundation regime did not affect decomposition. These findings suggest the reintroduction of tidal flow to an impounded salt marsh can have mixed effects; recolonization by the native cordgrass could supply labile OM to sediment and slow carbon sequestration, while an increase in salinity might inhibit decomposition and accelerate sequestration.

  10. A HYDRODYNAMICAL SOLUTION FOR THE ''TWIN-TAILED'' COLLIDING GALAXY CLUSTER ''EL GORDO''

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Molnar, Sandor M.; Broadhurst, Tom, E-mail: sandor@phys.ntu.edu.tw

    The distinctive cometary X-ray morphology of the recently discovered massive galaxy cluster ''El Gordo'' (ACT-CT J0102–4915; z = 0.87) indicates that an unusually high-speed collision is ongoing between two massive galaxy clusters. A bright X-ray ''bullet'' leads a ''twin-tailed'' wake, with the Sunyaev-Zel'dovich (SZ) centroid at the end of the northern tail. We show how the physical properties of this system can be determined using our FLASH-based, N-body/hydrodynamic model, constrained by detailed X-ray, SZ, and Hubble lensing and dynamical data. The X-ray morphology and the location of the two dark matter components and the SZ peak are accurately described by amore » simple binary collision viewed about 480 million years after the first core passage. We derive an impact parameter of ≅300 kpc, and a relative initial infall velocity of ≅2250 km s{sup –1} when separated by the sum of the two virial radii assuming an initial total mass of 2.15 × 10{sup 15} M {sub ☉} and a mass ratio of 1.9. Our model demonstrates that tidally stretched gas accounts for the northern X-ray tail along the collision axis between the mass peaks, and that the southern tail lies off axis, comprising compressed and shock heated gas generated as the less massive component plunges through the main cluster. The challenge for ΛCDM will be to find out if this physically extreme event can be plausibly accommodated when combined with the similarly massive, high-infall-velocity case of the Bullet cluster and other such cases being uncovered in new SZ based surveys.« less

  11. Assessment of sediments in the riverine impoundments of national wildlife refuges in the Souris River Basin, North Dakota

    USGS Publications Warehouse

    Tangen, Brian A.; Laubhan, Murray K.; Gleason, Robert A.

    2014-01-01

    Accelerated sedimentation of reservoirs and riverine impoundments is a major concern throughout the United States. Sediments not only fill impoundments and reduce their effective life span, but they can reduce water quality by increasing turbidity and introducing harmful chemical constituents such as heavy metals, toxic elements, and nutrients. U.S. Fish and Wildlife Service national wildlife refuges in the north-central part of the United States have documented high amounts of sediment accretion in some wetlands that could negatively affect important aquatic habitats for migratory birds and other wetland-dependent wildlife. Therefore, information pertaining to sediment accumulation in refuge impoundments potentially is important to guide conservation planning, including future management actions of individual impoundments. Lands comprising Des Lacs, Upper Souris, and J. Clark Salyer National Wildlife Refuges, collectively known as the Souris River Basin refuges, encompass reaches of the Des Lacs and Souris Rivers of northwestern North Dakota. The riverine impoundments of the Souris River Basin refuges are vulnerable to sedimentation because of the construction of in-stream dams that interrupt and slow river flows and because of post-European settlement land-use changes that have increased the potential for soil erosion and transport to rivers. Information regarding sediments does not exist for these refuges, and U.S. Fish and Wildlife Service personnel have expressed interest in assessing refuge impoundments to support refuge management decisions. Sediment cores and surface sediment samples were collected from impoundments within Des Lacs, Upper Souris, and J. Clark Salyer National Wildlife Refuges during 2004–05. Cores were used to estimate sediment accretion rates using radioisotope (cesium-137 [137Cs], lead-210 [210Pb]) dating techniques. Sediment cores and surface samples were analyzed for a suite of elements and agrichemicals, respectively. Examination of

  12. An examination of Washington state’s vehicle impoundment law for motorcycle endorsements : traffic tech.

    DOT National Transportation Integrated Search

    2013-01-01

    In July 2007, Washington State modified its vehicle code : to clarify that its existing impoundment law for unlicensed : drivers also applies to operators without specially : endorsed licenses, including motorcycle riders, and : expressly allows law ...

  13. Sharptooth catfish shows its metal: a case study of metal contamination at two impoundments in the Olifants River, Limpopo river system, South Africa.

    PubMed

    Jooste, Antoinette; Marr, Sean M; Addo-Bediako, Abraham; Luus-Powell, Wilmien J

    2015-02-01

    Clarias gariepinus is increasing in importance as a global aquaculture species with a 100 fold increase in production over the past decade but this species still remains one of the most important wild harvested freshwater food fish throughout rural Africa. However, this species has been shown to accumulate metals from contaminated inland waters. In this paper, the metal concentrations in muscle tissue of C. gariepinus from two main-stem impoundments in the Olifants River, Limpopo Basin, were measured and a desktop risk assessment based on the US-EPA methodology completed to evaluate whether long-term consumption of C. gariepinus from these impoundments may pose a health risk to rural communities. Our results show that metals are accumulating in the muscle tissue of C. gariepinus and have appeared to have increased in the last two decades. Risk assessment generated Hazard quotients (HQ) greater than 1 indicate that long term consumption of fish from these impoundments may cause adverse health impacts. We found that lead (HQ=9), antimony (HQ=14), cobalt (HQ=2) and chromium (HQ=1) at one impoundment and lead (HQ=2) at the other impoundment were above acceptable levels for weekly consumption of 150 g C. gariepinus muscle tissue. Copyright © 2014 Elsevier Inc. All rights reserved.

  14. Monticello Mill Tailings Site Operable Unit III Annual Groundwater Report May 2014 Through April 2015, October 2015

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Nguyen, Jason; Smith, Fred

    This report provides the annual analysis of water quality restoration progress, cumulative through April 2015, for Operable Unit (OU) III, surface water and groundwater, of the U.S. Department of Energy (DOE) Office of Legacy Management Monticello Mill Tailings Site (MMTS). The MMTS is a Comprehensive Environmental Response, Compensation, and Liability Act National Priorities List site located in and near the city of Monticello, San Juan County, Utah. MMTS comprises the 110-acre site of a former uranium- and vanadium-ore-processing mill (mill site) and 1,700 acres of surrounding private and municipal property. Milling operations generated 2.5 million cubic yards of waste (tailings)more » from 1942 to 1960. The tailings were impounded at four locations on the mill site. Inorganic constituents in the tailings drained from the impoundments to contaminate local surface water (Montezuma Creek) and groundwater in the underlying alluvial aquifer. Mill tailings dispersed by wind and water also contaminated properties surrounding and downstream of the mill site. Remedial actions to remove and isolate radiologically contaminated soil, sediment, and debris from the former mill site (OU I) and surrounding properties (OU II) were completed in 1999 with the encapsulation of the wastes in an engineered repository located on DOE property 1 mile south of the former mill site. Contamination of groundwater and surface water remains within OU III at levels that exceed water quality protection standards. Uranium is the primary contaminant of concern. LM implemented monitored natural attenuation with institutional controls as the OU III remedy in 2004. Because groundwater restoration proceeded more slowly than expected and did not meet performance criteria established in the OU III Record of Decision (June 2004), LM implemented a contingency action in 2009 by an Explanation of Significant Difference to include a pump-and-treat system using a single extraction well and treatment by

  15. Preparation of intact monomeric collagen from rat tail tendon and skin and the structure of the nonhelical ends in solution.

    PubMed

    Chandrakasan, G; Torchia, D A; Piez, K A

    1976-10-10

    Procedures for the preparation of soluble collagen from rat skin and tail tendon were reviewed and revised to permit the preparation of native monomeric collagen with intact nonhelical ends. The degree of intactness was estimated from the tyrosine content, which is present only in the nonhelical ends, and by mobility of the COOH-terminal cyanogen bromide peptide of the alpha1 chain on sodium dodecyl sulfate gels. The amount of covalently cross-linked polymeric material present was estimated by molecular sieve chromatography of denatured samples. Rapid purification in the cold was sufficient to prevent or greatly reduce proteolytic alteration. Fractionation by salt precipitation at acid pH was effective in reducing the content of polymeric material. Rat tail tendon yielded completely intact native collagen, but some high molecular weight aggregates remained. Collagen from the skin of lathyritic rats was easier to obtain free of aggregates, but contained about 1 less tyrosine residue per alpha1 chain even when isolated in the presence of enzyme inhibitors. Proton NMR spectra of denatured acidic solutions of these preparations showed that 4 to 5 tyrosine residues per alpha chain were present, confirming the chemical analysis. Spectra of the native molecule showed that about the same number of tyrosine residues per chain are in rapid motion, unlike residues in the helical portion of the molecule, a result which shows that the nonhelical ends of the native molecule are unstructured in acidic solution.

  16. Evaluation of Major Dike-Impounded Ground-Water Reservoirs, Island of Oahu

    USGS Publications Warehouse

    Takasaki, Kiyoshi J.; Mink, John Francis

    1985-01-01

    Ground-water reservoirs impounded by volcanic dikes receive a substantial part of the total recharge to ground water on the island of Oahu because they generally underlie the rainiest areas. These reservoirs accumulate the infiltration from rainfall, store it temporarily, and steadily leak it to abutting basal reservoirs or to streams cutting into them. The dike reservoirs have high hydraulic heads and are mostly isolated from saline water. The most important and productive of the dike-impounded reservoirs are in an area of about 135 square miles in the main fissure zone of the Koolau volcano where the top of the dike-impounded water reaches an altitude of at least 1,000 feet. Water is impounded and stored both above and below sea level. The water stored above sea level in the 135 square mile area has been roughly estimated at 560 billion gallons. In comparison, the water stored above sea level in reservoirs underlying a dike-intruded area of about 53 square miles in the Waianae Range has been roughly estimated at 100 billion gallons. Storage below sea level is indeterminable, owing to uncertainties about the ability of the rock to store water as dike density increases and porosity decreases. Tunnels, by breaching dike controls, have reduced the water stored above sea level by at least 50 billion gallons in the Koolau Range and by 5 1/2 billion gallons in the Waianae Range, only a small part of the total water stored. Total leakage from storage in the Koolau Range has been estimated at about 280 Mgal/d (million gallons per day). This estimated leakage from the dike-impounded reservoirs makes up a significant part of the ground-water yield of the Koolau Range, which has been estimated to range from 450 to 580 Mgal/d. The largest unused surface leakage is in the Kaneohe, Kahana, and Punaluu areas, and the largest unused underflow occurs in the Waialee, Hauula-Laie, Punaluu, and Kahana areas. The unused underflow leakage is small in areas near and east of Waialae, but

  17. Weighted Kolmogorov-Smirnov test: accounting for the tails.

    PubMed

    Chicheportiche, Rémy; Bouchaud, Jean-Philippe

    2012-10-01

    Accurate goodness-of-fit tests for the extreme tails of empirical distributions is a very important issue, relevant in many contexts, including geophysics, insurance, and finance. We have derived exact asymptotic results for a generalization of the large-sample Kolmogorov-Smirnov test, well suited to testing these extreme tails. In passing, we have rederived and made more precise the approximate limit solutions found originally in unrelated fields, first in [L. Turban, J. Phys. A 25, 127 (1992)] and later in [P. L. Krapivsky and S. Redner, Am. J. Phys. 64, 546 (1996)].

  18. Near-tail reconnection as the cause of cometary tail disconnections

    NASA Technical Reports Server (NTRS)

    Russell, C. T.; Saunders, M. A.; Phillips, J. L.; Fedder, J. A.

    1986-01-01

    In a cometary tail disconnection event the plasma tail appears to separate from the coma and to accelerate away from it. As this occurs a new tail begins to form. It is proposed that these disconnections arise in a manner analogous to geomagnetic substorms, i.e., by the formation of a strongly reconnecting region in the near tail that forms a magnetic island in the coma and ejects the plasma tail by strengthening the magnetic 'slingshot' within the tail. This reconnection process may be triggered by several different processes, such as interplanetary shocks or variations in the Alfven Mach number.

  19. A risk assessment of water salinization during the initial impounding period of a proposed reservoir in Tianjin, China.

    PubMed

    Zhu, Liqin; Jiang, Cuiling; Wang, Youheng; Peng, Yanmei; Zhang, Peng

    2013-09-01

    Water salinization of coastal reservoirs seriously threatens the safety of their water supply. To elucidate the mechanism of salinization and to quantitatively analyze the risk in the initial period of the impoundment of a proposed reservoir in Tianjin Binhai New Area, laboratory and field simulation experiments were implemented and integrated with the actual operation of Beitang Reservoir, which is located in the same region and has been operational for many years. The results suggested that water salinization of the proposed reservoir was mainly governed by soil saline release, evaporation and leakage. Saline release was the prevailing factor in the earlier stage of the impoundment, then the evaporation and leakage effects gradually became notable over time. By referring to the actual case of Beitang Reservoir, it was predicted that the chloride ion (Cl(-)) concentration of the water during the initial impounding period of the proposed reservoir would exceed the standard for quality of drinking water from surface water sources (250 mg L(-1)), and that the proposed reservoir had a high risk of water salinization.

  20. Aerodynamics of a Flapping Airfoil with a Flexible Tail

    NASA Astrophysics Data System (ADS)

    Lai, Alan Kai San

    This dissertation presents computational solutions to an airfoil in a oscillatory heaving motion with a aeroelastically flexible tail attachment. An unsteady potential flow solver is coupled to a structural solver to obtain the aeroelastic flow solution over an inviscid fluid to investigate the propulsive performance of such a configuration. The simulation is then extended to a two-dimensional viscous solver by coupling NASA's CFL3D solver to the structural solver to study how the flow is altered by the presence of viscosity. Finally, additional simulations are done in three dimensions over wings with varying aspect ratio to study the three-dimensional effects on the propulsive performance of an airfoil with an aeroelastic tail. The computation reveals that the addition of the aeroelastic trailing edge improved the thrust generated by a heaving airfoil significantly. As the frequency of the heaving motion increases, the thrust generated by the airfoil with the tail increases exponentially. In an inviscid fluid, the increase in thrust is insufficient to overcome the increase in power required to maintain the motion and as a result the overall propulsive efficiency is reduced. When the airfoil is heaving in a viscous fluid, the presence of a suction boundary layer and the appearance of leading edge vortex increase the thrust generated to such an extent that the propulsive efficiency is increased by about 3% when compared to the same airfoil with a rigid tail. The three-dimensional computations shows that the presence of the tip vorticies suppress some of the increase in thrust observed in the two-dimensional viscous computations for short span wings. For large span wings, the overall thrust enhancing capabilities of the aeroelastic tail is preserved.

  1. 75 FR 64974 - Notice of Data Availability on Coal Combustion Residual Surface Impoundments

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-21

    ...-2009-0640; FRL-9216-3] RIN 2050-AE81 Notice of Data Availability on Coal Combustion Residual Surface... rulemaking (75 FR 51434, August 20, 2010) on the Disposal of Coal Combustion Residuals from Electric... Requests that EPA sent to electric utilities on their coal combustion residual surface impoundments as well...

  2. 40 CFR 63.7905 - What emissions limitations or work practice standards must I meet for surface impoundments?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS... Pollutants: Site Remediation Surface Impoundments § 63.7905 What emissions limitations or work practice...

  3. 40 CFR 63.7905 - What emissions limitations or work practice standards must I meet for surface impoundments?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS... Pollutants: Site Remediation Surface Impoundments § 63.7905 What emissions limitations or work practice...

  4. 40 CFR 63.7905 - What emissions limitations or work practice standards must I meet for surface impoundments?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS... Pollutants: Site Remediation Surface Impoundments § 63.7905 What emissions limitations or work practice...

  5. 40 CFR 63.7905 - What emissions limitations or work practice standards must I meet for surface impoundments?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS... Pollutants: Site Remediation Surface Impoundments § 63.7905 What emissions limitations or work practice...

  6. 40 CFR 63.7905 - What emissions limitations or work practice standards must I meet for surface impoundments?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS... Pollutants: Site Remediation Surface Impoundments § 63.7905 What emissions limitations or work practice...

  7. Tail gut cyst.

    PubMed

    Rao, G Mallikarjuna; Haricharan, P; Ramanujacharyulu, S; Reddy, K Lakshmi

    2002-01-01

    The tail gut is a blind extension of the hindgut into the tail fold just distal to the cloacal membrane. Remnants of this structure may form tail gut cyst. We report a 14-year-old girl with tail gut cyst that presented as acute abdomen. The patient recovered after cyst excision.

  8. Telling tails: selective pressures acting on investment in lizard tails.

    PubMed

    Fleming, Patricia A; Valentine, Leonie E; Bateman, Philip W

    2013-01-01

    Caudal autotomy is a common defense mechanism in lizards, where the animal may lose part or all of its tail to escape entrapment. Lizards show an immense variety in the degree of investment in a tail (i.e., length) across species, with tails of some species up to three or four times body length (snout-vent length [SVL]). Additionally, body size and form also vary dramatically, including variation in leg development and robustness and length of the body and tail. Autotomy is therefore likely to have fundamentally different effects on the overall body form and function in different species, which may be reflected directly in the incidence of lost/regenerating tails within populations or, over a longer period, in terms of relative tail length for different species. We recorded data (literature, museum specimens, field data) for relative tail length (n=350 species) and the incidence of lost/regenerating tails (n=246 species). We compared these (taking phylogeny into account) with intrinsic factors that have been proposed to influence selective pressures acting on caudal autotomy, including body form (robustness, body length, leg development, and tail specialization) and ecology (foraging behavior, physical and temporal niches), in an attempt to identify patterns that might reflect adaptive responses to these different factors. More gracile species have relatively longer tails (all 350 spp., P < 0.001; also significant for five of the six families tested separately), as do longer (all species, P < 0.001; Iguanidae, P < 0.05; Lacertidae, P < 0.001; Scindidae, P < 0.001), climbing (all species, P < 0.05), and diurnal (all species, P < 0.01; Pygopodidae, P < 0.01) species; geckos without specialized tails (P < 0.05); or active-foraging skinks (P < 0.05). We also found some relationships with the data for caudal autotomy, with more lost/regenerating tails for nocturnal lizards (all 246 spp., P < 0.01; Scindidae, P < 0.05), larger skinks (P < 0.05), climbing geckos (P < 0

  9. 40 CFR 61.222 - Standard.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... uranium mill tailings pile that are no longer operational shall not exceed 20 pCi/(m2-sec) (1.9 pCi/(ft2-sec)) of radon-222. (b) Once a uranium mill tailings pile or impoundment ceases to be operational it...

  10. Preliminary Toxicological Analysis of the Effect of Coal Slurry Impoundment Water on Human Liver Cells

    USGS Publications Warehouse

    Bunnell, Joseph E.

    2008-01-01

    Coal is usually 'washed' with water and a variety of chemicals to reduce its content of sulfur and mineral matter. The 'washings' or 'coal slurry' derived from this process is a viscous black liquid containing fine particles of coal, mineral matter, and other dissolved and particulate substances. Coal slurry may be stored in impoundments or in abandoned underground mines. Human health and environmental effects potentially resulting from leakage of chemical substances from coal slurry into drinking water supplies or aquatic ecosystems have not been systematically examined. Impoundments are semipermeable, presenting the possibility that inorganic and organic substances, some of which may be toxic, may contaminate ground or surface water. The Agency for Toxic Substances and Disease Registry, part of the Centers for Disease Control and Prevention, has concluded that well water in Mingo County, West Virginia, constitutes a public health hazard.

  11. Correlating Microbial Diversity Patterns with Geochemistry in an Extreme and Heterogeneous Environment of Mine Tailings

    PubMed Central

    Liu, Jun; Hua, Zheng-Shuang; Chen, Lin-Xing; Kuang, Jia-Liang; Li, Sheng-Jin; Shu, Wen-Sheng

    2014-01-01

    Recent molecular surveys have advanced our understanding of the forces shaping the large-scale ecological distribution of microbes in Earth's extreme habitats, such as hot springs and acid mine drainage. However, few investigations have attempted dense spatial analyses of specific sites to resolve the local diversity of these extraordinary organisms and how communities are shaped by the harsh environmental conditions found there. We have applied a 16S rRNA gene-targeted 454 pyrosequencing approach to explore the phylogenetic differentiation among 90 microbial communities from a massive copper tailing impoundment generating acidic drainage and coupled these variations in community composition with geochemical parameters to reveal ecological interactions in this extreme environment. Our data showed that the overall microbial diversity estimates and relative abundances of most of the dominant lineages were significantly correlated with pH, with the simplest assemblages occurring under extremely acidic conditions and more diverse assemblages associated with neutral pHs. The consistent shifts in community composition along the pH gradient indicated that different taxa were involved in the different acidification stages of the mine tailings. Moreover, the effect of pH in shaping phylogenetic structure within specific lineages was also clearly evident, although the phylogenetic differentiations within the Alphaproteobacteria, Deltaproteobacteria, and Firmicutes were attributed to variations in ferric and ferrous iron concentrations. Application of the microbial assemblage prediction model further supported pH as the major factor driving community structure and demonstrated that several of the major lineages are readily predictable. Together, these results suggest that pH is primarily responsible for structuring whole communities in the extreme and heterogeneous mine tailings, although the diverse microbial taxa may respond differently to various environmental conditions

  12. OVERVIEW OF CYANIDE PLANT FOUNDATIONS, ZINC BOXES, TANKS, AND TAILINGS ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    OVERVIEW OF CYANIDE PLANT FOUNDATIONS, ZINC BOXES, TANKS, AND TAILINGS PILES, LOOKING NORTHEAST. THE LOWER TRAM TERMINAL AND MILL SITE IS AT TOP CENTER IN THE DISTANCE. THE DARK SPOT JUST BELOW THE TRAM TERMINAL ARE REMAINS OF THE DEWATERING BUILDING. THE MAIN ACCESS ROAD IS AT UPPER LEFT. THE FOUNDATIONS AT CENTER SUPPORTED SIX 25 FT. OR GREATER DIAMETER SETTLING TANKS WHERE TAILINGS FROM THE MILL SETTLED IN A CYANIDE SOLUTION IN ORDER TO RECLAIM ANY GOLD CONTENT. THE PREGNANT SOLUTION WAS THEN RUN THROUGH THE ZINC BOXES ON THE GROUND AT CENTER RIGHT, WHERE ZINC SHAVINGS WERE INTRODUCED, CAUSING THE GOLD TO PRECIPITATE OUT OF THE CYANIDE SOLUTION, WHICH COULD BE USED AGAIN. THE FLAT AREA IN THE FOREGROUND WITH THE TANK AND TANK HOOPS IS THE FOOTPRINT OF A LARGE BUILDING WHERE THE PRECIPITATION AND FURTHER FILTERING AND FINAL CASTING TOOK PLACE. - Keane Wonder Mine, Park Route 4 (Daylight Pass Cutoff), Death Valley Junction, Inyo County, CA

  13. Phenolic contamination in the sand-and-gravel aquifer from a surface impoundment of wood treatment wastes, Pensacola, Florida

    USGS Publications Warehouse

    Troutman, D.E.; Godsy, E.M.; Goerlitz, D.F.; Ehrlich, G.G.

    1984-01-01

    Creosote and pentachlorophenol wastewaters discharged to unlined surface impoundments have resulted in groundwater contamination in the vicinity of an industrial site near Pensacola, Florida. Total phenol concentrations of 36,000 microgm/liter have been detected 40 ft below land surface in a test hole 100 ft south of an overflow impoundment but less than 10 microgm/liter 90 ft below land surface. Samples collected in test holes 1,350 ft downgradient from the surface impoundments and 100 ft north of Pensacola Bay, above and immediately below a clay lens, indicate that phenol contaminated groundwater may not be discharging directly into Pensacola Bay. Phenol concentrations exceeding 20 microgm/liter were detected in samples from a drainage ditch discharging directly into Bayou Chico. Microbiological data collected near the test site suggest that an anaerobic methanogenic ecosystem contributes to a reduction in phenol concentrations in groundwater. A laboratory study using bacteria isolated from the study site indicates that phenol, 2-methylphenol, and 3-methylphenol are significantly degraded and that methanogenesis reduces total phenol concentrations in laboratory digestors by 45%. Pentachlorophenol may inhibit methanogenesis at concentrations exceeding 0.45 milligm/liter. (USGS)

  14. Remediation strategy, capping construction and ongoing monitoring for the mill tailings pond, Ningyo-Toge uranium mine, Japan

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Hiroshi Saito; Tomihiro Taki

    2013-07-01

    Ningyo-toge Uranium Mine is subject to the environmental remediation. The main purposes are to take measures to ensure the radiation protection from the exposure pathways to humans in future, and to prevent the occurrence of mining pollution. The Yotsugi Mill Tailings Pond in the Ningyo-toge Uranium Mine has deposited mining waste and impounded water as a buffer reservoir before it is transferred to the Water Treatment Facility. It is located at the upstream of the water-source river and as the impact on its environment in case of earthquake is estimated significant, the highest priority has been put to it amongmore » mine-related facilities in the Mine. So far, basic concept has been examined and a great number of data has been acquired, and using the data, some remediation activities have already done, including capping construction for the upstream part of the Mill Tailings Pond. The capping is to reduce rainwater penetration to lower the burden of water treatment, and to reduce radon exhalation and dose rates. Only natural materials are used to alleviate the future maintenance. Data, including settlement amount and underground temperature is now being acquired and accumulated to verify the effectiveness of the capping, and used for the future remediation of the Downstream with revision of its specifications if necessary. (authors)« less

  15. Weighted Kolmogorov-Smirnov test: Accounting for the tails

    NASA Astrophysics Data System (ADS)

    Chicheportiche, Rémy; Bouchaud, Jean-Philippe

    2012-10-01

    Accurate goodness-of-fit tests for the extreme tails of empirical distributions is a very important issue, relevant in many contexts, including geophysics, insurance, and finance. We have derived exact asymptotic results for a generalization of the large-sample Kolmogorov-Smirnov test, well suited to testing these extreme tails. In passing, we have rederived and made more precise the approximate limit solutions found originally in unrelated fields, first in [L. Turban, J. Phys. A1361-644710.1088/0305-4470/25/3/008 25, 127 (1992)] and later in [P. L. Krapivsky and S. Redner, Am. J. Phys.AJPIAS0002-950510.1119/1.18152 64, 546 (1996)].

  16. Impacts of Freshwater Impoundment in the West Loch of Pearl Harbor

    DTIC Science & Technology

    1993-05-01

    absence of applicable non-point standards, the "Yellow Book" criteria for freshwater aquatic life or domestic water supply could be applied to evaluate the...Waimalu, Waipahu, Wahiawa, and Ewa water use districts and contains the largest groundwater body on Oahu, supplying more than 50 percent of the island’s...irrigation; desalt existing brackish water supplies, and; 3 create a freshwater impoundment in West Loch. 6I I I The Board of Water Supply (BWS) and

  17. An eco-friendly method for heavy metal removal from mine tailings.

    PubMed

    Arab, Fereshteh; Mulligan, Catherine N

    2018-06-01

    One of the serious environmental problems that society is facing today is mine tailings. These byproducts of the process of extraction of valuable elements from ores are a source of pollution and a threat to the environment. For example, mine tailings from past mining activities at Giant Mines, Yellowknife, are deposited in chambers, stopes, and tailing ponds close to the shores of The Great Slave Lake. One of the environmentally friendly approaches for removing heavy metals from these contaminated tailing is by using biosurfactants during the process of soil washing. The objective of this present study is to investigate the effect of sophorolipid (SL) concentration, the volume of washing solution per gram of medium, pH, and temperature on the efficiency of sophorolipids in removing heavy metals from mine tailings. It was found that the efficiency of the sophorolipids depends on its concentration, and is greatly affected by changes in pH, and temperature. The results of this experiment show that increasing the temperature from 15 to 23 °C, while using sophorolipids, resulted in an increase in the removal of iron, copper, and arsenic from the mine tailing specimen, from 0.25, 2.1, and 8.6 to 0.4, 3.3, and 11.7%. At the same time, increasing the temperature of deionized water (DIW) from 15 to 23 °C led to an increase in the removal of iron, copper, and arsenic from 0.03, 0.9, and 1.8 to 0.04, 1.1, and 2.1%, respectively. By increasing temperature from 23 to 35 °C, when using sophorolipids, 22% reduction in the removal of arsenic was observed. At the same time while using DI water as the washing solution, increasing temperature from 23 to 35 °C resulted in 6.2% increase in arsenic removal. The results from this present study indicate that sophorolipids are promising agents for replacing synthetic surfactants in the removal of arsenic and other heavy metals from soil and mine tailings.

  18. Relationships among catch, angler catisfaction, and fish assemblage characteristics of an urban small impoundment fishery

    USGS Publications Warehouse

    Ivasauskas, Tomas J.; Xiong, Wilson N.; Engman, Augustin C.; Fischer, Jesse R.; Kwak, Thomas J.; Rundle, Kirk R.

    2017-01-01

    Urban fisheries provide unique angling opportunities for people from traditionally underrepresented demographics. Lake Raleigh is a 38-ha impoundment located on the North Carolina State University campus in Raleigh. Like many urban fisheries, little is known about angler use and satisfaction or how angling catch rate is related to fish availability in Lake Raleigh. We characterized the recreational fishery and fish assemblage with concurrent creel and boat electrofishing surveys over the course of one year. In total, 245 anglers were interviewed on 68 survey days. On average, anglers spent 1.7 h fishing per trip and caught 0.385 fish h –1. A large proportion of anglers (43.9%) targeted multiple species, whereas 36.5% targeted largemouth bass (Micropterus salmoides), 10.0% targeted panfish (i.e., sunfishes [Lepomis spp.] and crappies [Pomoxis spp.]), and 9.6% targeted catfish (Ameiurus spp. and Ictalurus spp.). Most anglers (69.4%) were satisfied with their experience, and overall satisfaction was unrelated to catch rate. Pulsed-DC boat electrofishing was conducted on 25 dates, and 617 fish were sampled. Angler catch rate was unrelated to electrofishing catch rate, implying that anglers' catch rate was independent of fish density or availability. Our results demonstrate that even minimally managed urban fisheries can provide high angler satisfaction, with limited dedication of management resources. Relationships Among Catch, Angler Satisfaction, and Fish Assemblage Characteristics of an Urban Small Impoundment Fishery (PDF Download Available). Available from: https://www.researchgate.net/publication/316636550_Relationships_Among_Catch_Angler_Satisfaction_and_Fish_Assemblage_Characteristics_of_an_Urban_Small_Impoundment_Fishery [accessed Aug 11, 2017].

  19. Solution Structure and Membrane Interaction of the Cytoplasmic Tail of HIV-1 gp41 Protein.

    PubMed

    Murphy, R Elliot; Samal, Alexandra B; Vlach, Jiri; Saad, Jamil S

    2017-11-07

    The cytoplasmic tail of gp41 (gp41CT) remains the last HIV-1 domain with an unknown structure. It plays important roles in HIV-1 replication such as mediating envelope (Env) intracellular trafficking and incorporation into assembling virions, mechanisms of which are poorly understood. Here, we present the solution structure of gp41CT in a micellar environment and characterize its interaction with the membrane. We show that the N-terminal 45 residues are unstructured and not associated with the membrane. However, the C-terminal 105 residues form three membrane-bound amphipathic α helices with distinctive structural features such as variable degree of membrane penetration, hydrophobic and basic surfaces, clusters of aromatic residues, and a network of cation-π interactions. This work fills a major gap by providing the structure of the last segment of HIV-1 Env, which will provide insights into the mechanisms of Gag-mediated Env incorporation as well as the overall Env mobility and conformation on the virion surface. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Simulated effects of impoundment of lake seminole on ground-water flow in the upper Floridan Aquifer in southwestern Georgia and adjacent parts of Alabama and Florida

    USGS Publications Warehouse

    Jones, L. Elliott; Torak, Lynn J.

    2004-01-01

    Hydrologic implications of the impoundment of Lake Seminole in southwest Georgia and its effect on components of the surface- and ground-water flow systems of the lower Apalachicola?Chattahoochee?Flint (ACF) River Basin were investigated using a ground-water model. Comparison of simulation results of postimpoundment drought conditions (October 1986) with results of hypothetical preimpoundment conditions (a similar drought prior to 1955) provides a qualitative measure of the changes in hydraulic head and ground-water flow to and from streams and Lake Seminole, and across State lines caused by the impoundment. Based on the simulation results, the impoundment of Lake Seminole changed ground-water flow directions within about 20?30 miles of the lake, reducing the amount of ground water flowing from Florida to Georgia southeast of the lake. Ground-water storage was increased by the impoundment, as indicated by a simulated increase of as much as 26 feet in the water level in the Upper Floridan aquifer. The impoundment of Lake Seminole caused changes to simulated components of the ground-water budget, including reduced discharge from the Upper Floridan aquifer to streams (315 million gallons per day); reduced recharge from or increased discharge to regional ground-water flow at external model boundaries (totaling 183 million gallons per day); and reduced recharge from or increased discharge to the undifferentiated overburden (totaling 129 million gallons per day).

  1. REAR PROFILE OF TAIL FROM SECOND LEVEL OF TAIL DOCK ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    REAR PROFILE OF TAIL FROM SECOND LEVEL OF TAIL DOCK STAND, SHOWING AIRCRAFT NUMBER (319), HORIZONTAL STABILIZER, TAIL CONE AND COOLING CTS FOR THE AUXILIARY POWER UNIT (APU), MECHANIC PAUL RIDEOUT IS LOWERING THE BALANCE PANELS ON THE STABILIZERS FOR LUBRICATION AND INSPECTION. - Greater Buffalo International Airport, Maintenance Hangar, Buffalo, Erie County, NY

  2. A long-term comparison of carbon sequestration rates in impounded and naturally tidal freshwater marshes along the lower Waccamaw River, South Carolina

    USGS Publications Warehouse

    Drexler, Judith Z.; Krauss, Ken W.; Sasser, M. Craig; Fuller, Christopher C.; Swarzenski, Christopher M.; Powell, Amber; Swanson, Kathleen M.; Orlando, James L.

    2013-01-01

    Carbon storage was compared between impounded and naturally tidal freshwater marshes along the Lower Waccamaw River in South Carolina, USA. Soil cores were collected in (1) naturally tidal, (2) moist soil (impounded, seasonally drained since ~1970), and (3) deeply flooded “treatments” (impounded, flooded to ~90 cm since ~2002). Cores were analyzed for % organic carbon, % total carbon, bulk density, and 210Pb and 137Cs for dating purposes. Carbon sequestration rates ranged from 25 to 200 g C m−2 yr−1 (moist soil), 80–435 g C m−2 yr−1 (naturally tidal), and 100–250 g C m−2 yr−1 (deeply flooded). The moist soil and naturally tidal treatments were compared over a period of 40 years. The naturally tidal treatment had significantly higher carbon storage (mean = 219 g C m−2 yr−1 vs. mean = 91 g C m−2 yr−1) and four times the vertical accretion rate (mean = 0.84 cm yr−1 vs. mean = 0.21 cm yr−1) of the moist soil treatment. The results strongly suggest that the long drainage period in moist soil management limits carbon storage over time. Managers across the National Wildlife Refuge system have an opportunity to increase carbon storage by minimizing drainage in impoundments as much as practicable.

  3. Effect of magnetic starch on the clarification of hematite tailings wastewater

    NASA Astrophysics Data System (ADS)

    Yue, Tao; Wu, Xiqing

    2018-02-01

    The magnetic starch solution, synthesized by mixing the caustic starch, the Fe2+ solution (in some cases containing the Zn2+, Cu2+, Mn2+ or Mg2+ ions) and H2O2 solution, was used as the flocculant to investigate its clarification effect on hematite tailings wastewater. Based on the clarification tests and adsorption analysis it was demonstrated that the magnetic starch produced better clarification effect than the caustic starch, and the adsorption of magnetic starch onto hematite tailings particles was also stronger than the caustic starch. AFM found that the magnetic interaction between magnetic seeds and hematite is characteristic of long range force and greatly strengthens the adsorption of magnetic seeds onto fine hematite for agglomeration. FTIR indicates the starch adsorbed onto the surfaces of hematite and magnetic seeds, thus acting as the bridging between hematite particles and magnetic seeds, resulting in an intensified coverage of the starch onto hematite and positive action in the clarification.

  4. Traveling waves and their tails in locally resonant granular systems

    DOE PAGES

    Xu, H.; Kevrekidis, P. G.; Stefanov, A.

    2015-04-22

    In the present study, we revisit the theme of wave propagation in locally resonant granular crystal systems, also referred to as mass-in-mass systems. We use three distinct approaches to identify relevant traveling waves. In addition, the first consists of a direct solution of the traveling wave problem. The second one consists of the solution of the Fourier tranformed variant of the problem, or, more precisely, of its convolution reformulation (upon an inverse Fourier transform) in real space. Finally, our third approach will restrict considerations to a finite domain, utilizing the notion of Fourier series for important technical reasons, namely themore » avoidance of resonances, which will be discussed in detail. All three approaches can be utilized in either the displacement or the strain formulation. Typical resulting computations in finite domains result in the solitary waves bearing symmetric non-vanishing tails at both ends of the computational domain. Importantly, however, a countably infinite set of anti-resonance conditions is identified for which solutions with genuinely rapidly decaying tails arise.« less

  5. Traveling waves and their tails in locally resonant granular systems

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Xu, H.; Kevrekidis, P. G.; Stefanov, A.

    In the present study, we revisit the theme of wave propagation in locally resonant granular crystal systems, also referred to as mass-in-mass systems. We use three distinct approaches to identify relevant traveling waves. In addition, the first consists of a direct solution of the traveling wave problem. The second one consists of the solution of the Fourier tranformed variant of the problem, or, more precisely, of its convolution reformulation (upon an inverse Fourier transform) in real space. Finally, our third approach will restrict considerations to a finite domain, utilizing the notion of Fourier series for important technical reasons, namely themore » avoidance of resonances, which will be discussed in detail. All three approaches can be utilized in either the displacement or the strain formulation. Typical resulting computations in finite domains result in the solitary waves bearing symmetric non-vanishing tails at both ends of the computational domain. Importantly, however, a countably infinite set of anti-resonance conditions is identified for which solutions with genuinely rapidly decaying tails arise.« less

  6. LCDRS FLOW FROM DOUBLE-LINED LANDFILLS AND SURFACE IMPOUNDMENTS. Project Summary (EPA/600/SR-93/070)

    EPA Science Inventory

    A study, sponsored by the U.S. Environmental Protection Agency (EPA), on measured flows from leakage detection, collection, and removal systems (LDCRSs) of 28 double-lined landfills and 8 double-lined surface impoundments indicated — all landfills with geomembrane top liners l...

  7. Ionic Liquid-Solute Interactions Studied by 2D NOE NMR Spectroscopy.

    PubMed

    Khatun, Sufia; Castner, Edward W

    2015-07-23

    Intermolecular interactions between a Ru(2+)(bpy)3 solute and the anions and cations of four different ionic liquids (ILs) are investigated by 2D NMR nuclear Overhauser effect (NOE) techniques, including {(1)H-(19)F} HOESY and {(1)H-(1)H} ROESY. Four ILs are studied, each having the same bis(trifluoromethylsulfonyl)amide anion in common. Two of the ILs have aliphatic 1-alkyl-1-methylpyrrolidinium cations, while the other two ILs have aromatic 1-alkyl-3-methylimidazolium cations. ILs with both shorter (butyl) and longer (octyl or decyl) cationic alkyl substituents are studied. NOE NMR results suggest that the local environment of IL anions and cations near the Ru(2+)(bpy)3 solute is rather different from the bulk IL structure. The solute-anion and solute-cation interactions are significantly different both for ILs with short vs long alkyl tails and for ILs with aliphatic vs aromatic cation polar head groups. In particular, the solute-anion interactions are observed to be about 3 times stronger for the cations with shorter alkyl tails relative to the ILs with longer alkyl tails. The Ru(2+)(bpy)3 solute interacts with both the polar head and the nonpolar tail groups of the 1-butyl-1-methylpyrrolidinium cation but only with the nonpolar tail groups of the 1-decyl-1-methylpyrrolidinium cation.

  8. 40 CFR 61.222 - Standard.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS National Emission Standards for Radon Emissions From the Disposal of Uranium Mill Tailings § 61.222 Standard. (a) Radon-222 emissions to the ambient air from...-sec)) of radon-222. (b) Once a uranium mill tailings pile or impoundment ceases to be operational it...

  9. Modulation of Extreme Flood Levels by Impoundment Significantly Offset by Floodplain Loss Downstream of the Three Gorges Dam

    NASA Astrophysics Data System (ADS)

    Mei, Xuefei; Dai, Zhijun; Darby, Stephen E.; Gao, Shu; Wang, Jie; Jiang, Weiguo

    2018-04-01

    River flooding—the world's most significant natural hazard—is likely to increase under anthropogenic climate change. Most large rivers have been regulated by damming, but the extent to which these impoundments can mitigate extreme flooding remains uncertain. Here the catastrophic 2016 flood on the Changjiang River is first analyzed to assess the effects of both the Changjiang's reservoir cascade and the Three Gorges Dam (TGD), the world's largest hydraulic engineering project on downstream flood discharge and water levels. We show that the Changjiang's reservoir cascade impounded over 30.0 × 103 m3/s of flow at the peak of the flood on 25 July 2016, preventing the occurrence of what would otherwise have been the second largest flood ever recorded in the reach downstream of the TGD. Half of this flood water storage was retained by the TGD alone, meaning that impoundment by the TGD reduced peak water levels at the Datong hydrometric station (on 25 July) by 1.47 m, compared to pre-TGD conditions. However, downstream morphological changes, in particular, extensive erosion of the natural floodplain, offset this reduction in water level by 0.22 m, so that the full beneficial impact of floodwater retention by the TGD was not fully realized. Our results highlight how morphological adjustments downstream of large dams may inhibit their full potential to mitigate extreme flood risk.

  10. [Effects of Three Gorges Reservoir impoundment on the wetland ecosystem service value of Dongting Lake, South-central China].

    PubMed

    Li, Jing-Bao; Dai, Yong; Yin, Ri-Xin; Yang, Yan; Li, Yu-dan; Wang, Ke-ying

    2013-03-01

    Based on the field investigation and measurement, and by using the monetary method, this paper estimated the wetland ecosystem service value of Dongting Lake before and after the impoundment of Three Gorges Reservoir (in 1996 and 2010, respectively). After the impoundment, the total ecosystem service value increased from 156.69x10(8) yuan in 1996 to 177.11x10(8) yuan in 2010. The main services value in 1996 was in the order of flood storage and regulation > water storage and supply > air regulation > scientific research and education, while that in 2010 was leisure tourism > shipping transportation > air regulation > water storage and supply. In the total service value of the wetland ecosystem, the direct value associated with water decreased from 110. 85x10(8) in 1996 to 27.47x10(8) in 2010, with a decrement of 75.2%. Though the proportion of the direct value in the production and supply of material products had somewhat increase, the indirect value in ecological environment regulation and maintenance and in culture and society still maintained at about 80% of the total value. In addition to climate factors, the impoundment of Three Gorges Reservoir and the reduction of water and sediment from Yangtze River to the Lake were the crucial reasons leading to the changes of the wetland ecosystem service value of Dongting Lake.

  11. Tailings dam-break flow - Analysis of sediment transport

    NASA Astrophysics Data System (ADS)

    Aleixo, Rui; Altinakar, Mustafa

    2015-04-01

    A common solution to store mining debris is to build tailings dams near the mining site. These dams are usually built with local materials such as mining debris and are more vulnerable than concrete dams (Rico et al. 2008). of The tailings and the pond water generally contain heavy metals and various toxic chemicals used in ore extraction. Thus, the release of tailings due to a dam-break can have severe ecological consequences in the environment. A tailings dam-break has many similarities with a common dam-break flow. It is highly transient and can be severely descructive. However, a significant difference is that the released sediment-water mixture will behave as a non-Newtonian flow. Existing numerical models used to simulate dam-break flows do not represent correctly the non-Newtonian behavior of tailings under a dam-break flow and may lead to unrealistic and incorrect results. The need for experiments to extract both qualitative and quantitative information regarding these flows is therefore real and actual. The present paper explores an existing experimental data base presented in Aleixo et al. (2014a,b) to further characterize the sediment transport under conditions of a severe transient flow and to extract quantitative information regarding sediment flow rate, sediment velocity, sediment-sediment interactions a among others. Different features of the flow are also described and analyzed in detail. The analysis is made by means of imaging techniques such as Particle Image Velocimetry and Particle Tracking Velocimetry that allow extracting not only the velocity field but the Lagrangian description of the sediments as well. An analysis of the results is presented and the limitations of the presented experimental approach are discussed. References Rico, M., Benito, G., Salgueiro, AR, Diez-Herrero, A. and Pereira, H.G. (2008) Reported tailings dam failures: A review of the European incidents in the worldwide context , Journal of Hazardous Materials, 152, 846

  12. Geometrical and hydrogeological impact on the behaviour of deep-seated rock slides during reservoir impoundment

    NASA Astrophysics Data System (ADS)

    Lechner, Heidrun; Zangerl, Christian

    2015-04-01

    Given that there are still uncertainties regarding the deformation and failure mechanisms of deep-seated rock slides this study concentrates on key factors that influence the behaviour of rock slides in the surrounding of reservoirs. The focus is placed on the slope geometry, hydrogeology and kinematics. Based on numerous generic rock slide models the impacts of the (i) rock slide geometry, (ii) reservoir impoundment and level fluctuations, (iii) seepage and buoyancy forces and (iv) hydraulic conductivity of the rock slide mass and the basal shear zone are examined using limit equilibrium approaches. The geometry of many deep-seated rock slides in metamorphic rocks is often influenced by geological structures, e.g. fault zones, joints, foliation, bedding planes and others. With downslope displacement the rock slide undergoes a change in shape. Several observed rock slides in an advanced stage show a convex, bulge-like topography at the foot of the slope and a concave topography in the middle to upper part. Especially, the situation of the slope toe plays an important role for stability. A potentially critical situation can result from a partially submerged flat slope toe because the uplift due to water pressure destabilizes the rock slide. Furthermore, it is essential if the basal shear zone daylights at the foot of the slope or encounters alluvial or glacial deposits at the bottom of the valley, the latter having a buttressing effect. In this study generic rock slide models with a shear zone outcropping at the slope toe are established and systematically analysed using limit equilibrium calculations. Two different kinematic types are modelled: (i) a translational or planar and (ii) a rotational movement behaviour. Questions concerning the impact of buoyancy and pore pressure forces that develop during first time impoundment are of key interest. Given that an adverse effect on the rock slide stability is expected due to reservoir impoundment the extent of

  13. A Tale of Two Tails: Exploring Stellar Populations in the Tidal Tails of NGC 3256

    NASA Astrophysics Data System (ADS)

    Rodruck, Michael; Charlton, Jane C.; Konstantopoulos, Iraklis

    2016-01-01

    Galaxy interactions can inject material into the intergalactic medium via violent gravitational dynamics, often visualized in tidal tails. The composition of these tails has remained a mystery, as previous studies have focused on detecting tidal features, rather than the composite material itself. We have developed an observing program using deep, multiband imaging to probe the chaotic regions of tidal tails in search for an underlying stellar population. NGC 3256's twin tidal tails serve as a case study for this new technique. Our results show color values of u - g = 1.15 and r - i = 0.08 for the Western tail, and u - g = 1.33 and r - i = 0.22 for the Eastern tail, corresponding to discrepant ages between the tails of approximately 320 Myr and 785 Myr, respectively. With the interaction age of the system measured at 400 Myr, we find the stellar light in Western tail to be dominated by disrupted star clusters formed during and after the interaction, whereas the light from the Eastern tail is dominated by a 10 Gyr population originating from the host galaxies. We fit the Eastern tail color to a Mixed Stellar Population (MSP) model comprised 94% by mass of a 10 Gyr stellar population, and 6% of a 309 Myr population. We find 52% of the bolometric flux originating from this 10 Gyr population. We also detect a blue to red color gradient in each tail, running from galactic center to tail tip. In addition to tidal tail light, we detect 29 star cluster candidates (SCCs) in the Western tail and 19 in the Eastern, with mean ages of 282 Myr and 98 Myr respectively. Interestingly, we find an excess of very blue SCCs in the Eastern tail as compared to the Western tail, marking a recent, small episode of star formation.

  14. Ionic Liquid–Solute Interactions Studied by 2D NOE NMR Spectroscopy

    DOE PAGES

    Khatun, Sufia; Castner, Edward W.

    2014-11-26

    Intermolecular interactions between a Ru²⁺(bpy)₃ solute and the anions and cations of four different ionic liquids (ILs) are investigated by 2D NMR nuclear Overhauser effect (NOE) techniques, including {¹H-¹⁹F} HOESY and {¹H-¹H} ROESY. Four ILs are studied, each having the same bis(trifluoromethylsulfonyl)amide anion in common. Two of the ILs have aliphatic 1-alkyl-1-methylpyrrolidinium cations, while the other two ILs have aromatic 1-alkyl-3-methylimidazolium cations. ILs with both shorter (butyl) and longer (octyl or decyl) cationic alkyl substituents are studied. NOE NMR results suggest that the local environment of IL anions and cations near the Ru²⁺(bpy)₃ solute is rather different from the bulkmore » IL structure. The solute-anion and solute-cation interactions are significantly different both for ILs with short vs long alkyl tails and for ILs with aliphatic vs aromatic cation polar head groups. In particular, the solute-anion interactions are observed to be about 3 times stronger for the cations with shorter alkyl tails relative to the ILs with longer alkyl tails. The Ru²⁺(bpy)₃ solute interacts with both the polar head and the nonpolar tail groups of the 1- butyl-1-methylpyrrolidinium cation but only with the nonpolar tail groups of the 1-decyl-1-methylpyrrolidinium cation.« less

  15. Thermo-mechanical properties and microfabric of fly ash-stabilized gold tailings.

    PubMed

    Lee, Joon Kyu; Shang, Julie Q; Jeong, Sangseom

    2014-07-15

    This paper studies the changes in thermal conductivity, temperature, and unconfined compressive strength of gold tailings and fly ash mixtures during the curing period of 5 days. The microfabric of the cured mixtures was investigated with mercury intrusion porosimetry (MIP). The mixture samples were prepared at their maximum dry unit weight and optimum moisture content. Effect of adding fly ash to gold tailings (i.e., 0, 20, and 40% of the dry weight of tailings) was examined, and a comparison was made on samples prepared at the same fly ash content by replacing gold tailings with humic acid (i.e., gold tailings and humic acid ratios of 100:0, 90:10, and 80:20 by weight) or by varying pore fluid chemistry (i.e., water and salt solutions of 1M NaCl and CaCl2). The results show that the initial thermal conductivity of the samples is sensitive to the mixture proportion and a declination in the thermal conductivity is observed due to hydration of fly ash and evaporation. Inclusion of fly ash and salts into gold tailings improves the unconfined compressive strength but the presence of humic acid in samples leads to the decrease of the strength. MIP results reveal the pore structure changes associated with the packing states of the samples that reflect the influential factors considered. Copyright © 2014 Elsevier B.V. All rights reserved.

  16. Cyanobacteria and cyanotoxins are present in drinking water impoundments and groundwater wells in desert environments.

    PubMed

    Chatziefthimiou, Aspassia D; Metcalf, James S; Glover, W Broc; Banack, Sandra A; Dargham, Soha R; Richer, Renee A

    2016-05-01

    Desert environments and drylands experience a drastic scarcity of water resources. To alleviate dependence on freshwater for drinking water needs, countries have invested in infrastructure development of desalination plants. Collectively, the countries of the Arabian Gulf produce 45% of the world's desalinated water, which is stored in dams, mega-reservoirs and secondary house water tanks to secure drinking water beyond daily needs. Improper storage practices of drinking water in impoundments concomitant with increased temperatures and light penetration may promote the growth of cyanobacteria and accumulation of cyanotoxins. To shed light on this previously unexplored research area in desert environments, we examined drinking and irrigation water of urban and rural environments to determine whether cyanobacteria and cyanotoxins are present, and what are the storage and transportation practices as well as the environmental parameters that best predict their presence. Cyanobacteria were present in 80% of the urban and 33% of the rural water impoundments. Neurotoxins BMAA, DAB and anatoxin-a(S) were not detected in any of the water samples, although they have been found to accumulate in the desert soils, which suggests a bioaccumulation potential if they are leached into the aquifer. A toxic BMAA isomer, AEG, was found in 91.7% of rural but none of the urban water samples and correlated with water-truck transportation, light exposure and chloride ions. The hepatotoxic cyanotoxin microcystin-LR was present in the majority of all sampled impoundments, surpassing the WHO provisional guideline of 1 μg/l in 30% of the urban water tanks. Finally, we discuss possible management strategies to improve storage and transportation practices in order to minimize exposure to cyanobacteria and cyanotoxins, and actions to promote sustainable use of limited water resources. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. High resolution flow field prediction for tail rotor aeroacoustics

    NASA Technical Reports Server (NTRS)

    Quackenbush, Todd R.; Bliss, Donald B.

    1989-01-01

    The prediction of tail rotor noise due to the impingement of the main rotor wake poses a significant challenge to current analysis methods in rotorcraft aeroacoustics. This paper describes the development of a new treatment of the tail rotor aerodynamic environment that permits highly accurate resolution of the incident flow field with modest computational effort relative to alternative models. The new approach incorporates an advanced full-span free wake model of the main rotor in a scheme which reconstructs high-resolution flow solutions from preliminary, computationally inexpensive simulations with coarse resolution. The heart of the approach is a novel method for using local velocity correction terms to capture the steep velocity gradients characteristic of the vortex-dominated incident flow. Sample calculations have been undertaken to examine the principal types of interactions between the tail rotor and the main rotor wake and to examine the performance of the new method. The results of these sample problems confirm the success of this approach in capturing the high-resolution flows necessary for analysis of rotor-wake/rotor interactions with dramatically reduced computational cost. Computations of radiated sound are also carried out that explore the role of various portions of the main rotor wake in generating tail rotor noise.

  18. Release behavior of uranium in uranium mill tailings under environmental conditions.

    PubMed

    Liu, Bo; Peng, Tongjiang; Sun, Hongjuan; Yue, Huanjuan

    2017-05-01

    Uranium contamination is observed in sedimentary geochemical environments, but the geochemical and mineralogical processes that control uranium release from sediment are not fully appreciated. Identification of how sediments and water influence the release and migration of uranium is critical to improve the prevention of uranium contamination in soil and groundwater. To understand the process of uranium release and migration from uranium mill tailings under water chemistry conditions, uranium mill tailing samples from northwest China were investigated with batch leaching experiments. Results showed that water played an important role in uranium release from the tailing minerals. The uranium release was clearly influenced by contact time, liquid-solid ratio, particle size, and pH under water chemistry conditions. Longer contact time, higher liquid content, and extreme pH were all not conducive to the stabilization of uranium and accelerated the uranium release from the tailing mineral to the solution. The values of pH were found to significantly influence the extent and mechanisms of uranium release from minerals to water. Uranium release was monitored by a number of interactive processes, including dissolution of uranium-bearing minerals, uranium desorption from mineral surfaces, and formation of aqueous uranium complexes. Considering the impact of contact time, liquid-solid ratio, particle size, and pH on uranium release from uranium mill tailings, reducing the water content, decreasing the porosity of tailing dumps and controlling the pH of tailings were the key factors for prevention and management of environmental pollution in areas near uranium mines. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Influence of the impoundment of the Three Gorges Reservoir on the micro-seismicity and the 2013 M5.1 Badong earthquake (Yangtze, China)

    NASA Astrophysics Data System (ADS)

    Zhang, Huai; Cheng, Huihong; Pang, Yajin; Shi, Yaolin; Yuen, David A.

    2016-12-01

    On December 16, 2013, right after the Three Gorges Reservoir (TGR) reached its highest annual water level, a powerful M5.1 earthquake occurred in Badong County, China's Hubei Province. The epicenter is 5.5 km away from the upstream boundary and 100 km from the dam. Was this earthquake triggered by the impoundment of the TGR, and what are its subsequences? To answer these questions, we constructed a coupled three-dimensional poroelastic finite element model to examine the ground surface deformation, the Coulomb failure stress change (ΔCFS) due to the variation of elastic stress and pore pressure, and the elastic strain energy potential accumulation in the TGR region upon the occurrence of this event. Our calculated maximum surface deformation values beneath the TGR compare well with GPS observations, which validates our numerical model. At the hypocenter of the earthquake, ΔCFS is around 8.0 ∼ 11.0 kPa, revealing that it may be eventually triggered by the impoundment. We also discovered that the total elastic strain energy potential accumulation due to the impounded water load is around 1.7 × 1012 J, merely equivalent to 0.01% of the total energy released by this event, indicating that this earthquake is predominately controlled by the typical regional tectonic settings as well as the weak fault zones, and the reservoir impoundment might only facilitate its procedure or occurrence. Furthermore, the stress level in this region remains high after this earthquake and the subsequent reservoir-triggered micro-seismicity or even bigger event are highly possible.

  20. Assessing Natural Radionuclide Migration in the Legacy Tailings of Uranium Production

    NASA Astrophysics Data System (ADS)

    Bondarenko, G.; Koliabina, I.; Marinich, O.

    2011-12-01

    The former Prydniprovsky Chemical Plant in Dniprodzerzhynsk, Ukraine, processed uranium ore from 1949 until 1991. Multiple tailing ponds containing solid residual waste products from the uranium leaching and processing of uranium were accumulated along the Dnieper River, including the largest, adjacent to the Dnieper Reservoir, containing over 12 million tons of tailings. Samples for this study were selected from a core recovered from the Dnieper tailing pit in 2009, and used to assess radionuclide migration from tailing ponds. Samples were selected from different depths of the tailing pit core, analyzed for total radionuclide concentrations [Marinich et al., 2009], and successively leached using distilled water, followed by 1N ammonium acetate solution, and finally by 1N HCl solution. Leaching times were ~24 h at 15.17 °C. 238U, 230Th and 226Ra leachate activities were measured by γ-spectrometry with a Ge(Li) detector. 210Pb activity was measured using a SEB-01 scintillation β-spectrometer. Errors depended on measuring method, radionuclide, activity and exposure time: 238U, 11.9%; 230Th, 10.9%; 226Ra, 9.3%; 210Pb ~30%. The average total 238U activity in the tailing profile was 4 Bq/g. The concentration of 238U in the water leachates increased with depth from 14.5% (7-7.5 m), to 43% (11-11.5 m). The concentration of 238U in the acid leachates behaved similarly, increasing from 5.5 % to 15.5% with depth. While the total 230Th activity in increased from 30 Bq/g (7-7.5 m) to 540 Bq/g (11-11.5 m), the 230Th concentration in ammonium acetate leachates decreased from ˜15% to ˜1%. The concentration of 226Ra in all leachates was <1%, indicating that, under conditions of the Dnieper tailing pit, 226Ra is essentially immobile. The concentration of 210Pb in the leachates was as high as 10%. In general, the magnitude of mobile activity from the Dnieper tailing pit core samples decreases in the order 238U>230Th≥210Pb> 226Ra. Secular radioactive equilibrium in the 238U

  1. Wind-tunnel Investigation of End-plate Effects of Horizontal Tails on a Vertical Tail Compared with Available Theory

    NASA Technical Reports Server (NTRS)

    Murray, Harry E

    1946-01-01

    A vertical-tail model with stub fuselage was tested in combination with various simulated horizontal tails to determine the effect of horizontal-tail span and location on the aerodynamic characteristics of the vertical tail. Available theoretical data on end-plate effects were collected and presented in the form most suitable for design purposes. Reasonable agreement was obtained between the measured and theoretical end-plate effects of horizontal tails on vertical tails, and the data indicated that the end-plate effect was determined more by the location of the horizontal tail than by the span of the horizontal tail. The horizontal tail gave most end-plate effect when located near either tip of the vertical tail and, when located near the base of the vertical tail, the end-plate effect was increased by moving the horizontal tail rearward.

  2. The path and surviving tail of a comet that fell into the sun

    NASA Technical Reports Server (NTRS)

    Sekanina, Z.

    1982-01-01

    A satisfactory orbital solution for Comet Howard-Koomen-Michels 1979 XI is found on the assumption that the comet's line of apsides coincided with that of the Kreutz sungrazing comet group. The derived perihelion distance then shows that this is the first known case of a comet falling into the sun. A dust tail that survived the comet is studied as a particle flow phenomenon controlled by no force other than solar gravity and solar radiation pressure. The tail's outline is interpreted in terms of an onset of dust production, a peak repulsive force on the particles, and a circumsolar dustfree zone due to particle sublimation. It is shown that the surviving debris consisted mostly of absorbing, submicron size particles in hyperbolic trajectories convex to the sun and curving toward the earth. The tail width may be a product of the interaction of charged dust in the tail with a complicated structure of the coronal magnetic field.

  3. Sediment characteristics and configuration within the Otsego City Dam impoundment on the Kalamazoo River, Michigan, 2001-02

    USGS Publications Warehouse

    Rheaume, S.J.; Hubbell, D.L.; Rachol, C.M.; Simard, A.; Fuller, L.M.

    2004-01-01

    The removal of the Otsego City Dam on the Kalamazoo River at Otsego, Mich., is under consideration by the Michigan Department of Environmental Quality and the city of Otsego. The historical discharge of papermill waste containing polychlorinated biphenyls from sources upstream from the dam has led the U.S. Environmental Protection Agency to designate the Kalamazoo River from Morrow Dam near Comstock to its mouth near Saugatuck as a Federal Superfund site. The papermill waste is concentrated in organic sediment and kaolinite clay, with the sediment containing as much as 94 milligrams per kilogram polychlorinated biphenyls. This contaminated sediment could move if the dam is removed; therefore, it is necessary to estimate the characteristics and configuration of the sediment before removal plans begin. Data from augered sections and sediment cores show that the current Otsego City impoundment sediments were deposited in two distinctly different sedimentary environments: (1) lacustrine sediments consisting of organic-rich silt and clay, fine to medium sand, and some gravel deposited in a repetitive, cyclic fashion related to former stream velocities when the Otsego City impoundment water levels were 2-4 feet higher (1880s-1960s), and from downstream movement of lacustrine sediments during the removal of the upstream Plainwell Dam superstructure in the 1980s; and (2) more recent (1980s-2002) coarse-grained alluvium deposited on top of the lacustrine sediments. The volume of instream sediment contained within the Otsego City impoundment is estimated to be about 457,270 cubic yards. This estimate is based on the composite thicknesses of the lacustrine deposits and overlying alluvium, which were determined to contain PCBs, and does not include bank or flood-plain deposits.

  4. Mineralogy and geochemistry of efflorescent minerals on mine tailings and their potential impact on water chemistry.

    PubMed

    Grover, B P C; Johnson, R H; Billing, D G; Weiersbye, I M G; Tutu, H

    2016-04-01

    In the gold mining Witwatersrand Basin of South Africa, efflorescent mineral crusts are a common occurrence on and nearby tailings dumps during the dry season. The crusts are readily soluble and generate acidic, metal- and sulphate-rich solutions on dissolution. In this study, the metal content of efflorescent crusts at an abandoned gold mine tailings dump was used to characterise surface and groundwater discharges from the site. Geochemical modelling of the pH of the solution resulting from the dissolution of the crusts was used to better understand the crusts' potential impact on water chemistry. The study involved two approaches: (i) conducting leaching experiments on oxidised and unoxidised tailings using artificial rainwater and dilute sulphuric acid and correlating the composition of crusts to these leachates and (ii) modelling the dissolution of the crusts in order to gain insight into their mineralogy and their potential impact on receiving waters. The findings suggested that there were two chemically distinct discharges from the site, namely an aluminium- and magnesium-rich surface water plume and an iron-rich groundwater plume. The first plume was observed to originate from the oxidised tailings following leaching with rainwater while the second plume originated from the underlying unoxidised tailings with leaching by sulphuric acid. Both groups of minerals forming from the respective plumes were found to significantly lower the pH of the receiving water with simulations of their dissolution found to be within 0.2 pH units of experimental values. It was observed that metals in a low abundance within the crust (for example, iron) had a stronger influence on the pH of the resulting solutions than metals in a greater abundance (aluminium or magnesium). Techniques such as powder X-ray diffraction (PXRD) and in situ mineral determination techniques such as remote sensing can effectively determine the dominant mineralogy. However, the minerals or metals

  5. Heavy metal leaching from mine tailings as affected by plants

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Zhu, D.; Schwab, A.P.; Banks, M.K.

    A column experiment was conducted to determine the impact of soil cover and plants on heavy metal leaching from mine tailings and heavy metal contaminated soil. Columns made of PVC were constructed with 30 cm subsoil covered by 30 cm of mine tailings followed by 0, 30, or 60 cm subsoil covered by 30 cm of mine tailings followed by 0, 30, or 60 cm of clean topsoil. Two grasses, tall fescue (Festuca arundinacea Schreb.) and big bluestem (Andropogon gerardii), were grown in the columns. The columns were leached at a slow rate for 1 yr with a 0.001 Mmore » CaCl{sub 2} solution under unsaturated conditions. The presence of both tall fescue and big bluestem increased Zn and Cd concentrations in the leachate. Lead concentrations in leachates were not affected by the presence of plants. Although plants generally reduced the total amount of water leached, total mass of Zn and Cd leached generally was not impacted by plants. Total mass of Pb leached was positively correlated with total leachate collected from each column. Covering the mine tailings with 60 cm of topsoil increased the mass of Zn and Cd leached relative to no topsoil. When the subsoil was absent, Zn and Cd leaching increased by as much as 20-fold, verifying the ability of soil to act as a sink for metals. Mine tailing remediation by establishing vegetation can reduce Pb movement but may enhance short-term Cd and Zn leaching. However, the changes were relatively small and do not outweigh the benefits of using vegetation in mine tailings reclamation.« less

  6. Mineralogical and geochemical characterization of arsenic in an abandoned mine tailings of Korea.

    PubMed

    Ahn, Joo Sung; Park, Young Seog; Kim, Ju-Yong; Kim, Kyoung-Woong

    2005-04-01

    The mineralogical and chemical characteristics of As solid phases in arsenic-rich mine tailings from the Nakdong As-Bi mine in Korea was investigated. The tailings generated from the ore roasting process contained 4.36% of As whereas the concentration was up to 20.2% in some tailings from the cyanidation process for the Au extraction. Thin indurated layers and other secondary precipitates had formed at the surfaces of the tailings piles and the As contents of the hardened layers varied from 2.87 to 16.0%. Scorodite and iron arsenate (Fe3AsO7) were the primary As-bearing crystalline minerals. Others such as arsenolamprite, bernardite and titanium oxide arsenate were also found. The amorphous As-Fe phases often showed framboidal aggregates and gel type textures with desiccation cracks. Sequential extraction results also showed that 55.7-91.1% of the As in tailings were NH(4)-oxalate extractable As, further confirmed the predominance of amorphous As-Fe solid phases. When the tailings were equilibrated with de-ionized water, the solution exhibited extremely acidic conditions (pH 2.01-3.10) and high concentrations of dissolved As (up to 29.5 mg L(-1)), indicating high potentials for As to be released during rainfall events. The downstream water was affected by drainage from tailings and contained 12.7-522 microg L(-1) of As. The amorphous As-Fe phases in tailings have not entirely been stabilized through the long term natural weathering processes. To remediate the environmental harms they had caused, anthropogenic interventions to stabilize or immobilize As in the tailings pile should be explored.

  7. Dynamics of dissolved organic matter in riverine sediments affected by weir impoundments: Production, benthic flux, and environmental implications.

    PubMed

    Chen, Meilian; Kim, Sung-Han; Jung, Heon-Jae; Hyun, Jung-Ho; Choi, Jung Hyun; Lee, Hyo-Jin; Huh, In-Ae; Hur, Jin

    2017-09-15

    In order to understand the characteristics and dynamics of dissolved organic matter (DOM) in the sediment of rivers affected by impoundments, we examined the vertical profiles and the benthic fluxes of DOM in four different core sediments located at upstream sites of weirs in major rivers of South Korea. In three out of four sites, exponential accumulation of dissolved organic carbon (DOC) with depth was observed with the signature of seasonal variability. Except for the site displaying a below-detection limit of Fe(II), the general accumulation trends of DOC with depth was concurrent with the increases of Fe(II) and NH 4 + and the decrease of PO 4 3- , signifying a close linkage of the DOM dynamics with anaerobic respiration via iron reduction, an important early diagenesis pathway. The estimated benthic fluxes from the cores revealed that the sediments likely serve as DOC, chromophoric DOM (CDOM), and fluorescent DOM (FDOM) sources to the overlying water. The benthic effluxes based on DOC were comparable to the ranges previously reported in lake and coastal areas, and those of CDOM and FDOM showed even higher levels. These findings imply that impoundment-affected river systems would change the DOM composition of the overlying water, ultimately influencing the subsequent water treatment processes such as disinfection byproducts production and membrane fouling. A simple mass balance model indicated that the impoundment-affected river sediments may operate as a net carbon sink in the environments due to a greater extent of sedimentation compared to the estimated benthic efflux and sediment biological respiration. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. 49 CFR 195.264 - Impoundment, protection against entry, normal/emergency venting or pressure/vacuum relief for...

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... specified: (1) For tanks built to API Specification 12F, API Standard 620, and others (such as API Standard... accordance with section 4.3.2.3.1. (2) For tanks built to API 2510, the installation of impoundment must be in accordance with section 5 or 11 of API 2510 (incorporated by reference, see § 195.3). (c...

  9. 49 CFR 195.264 - Impoundment, protection against entry, normal/emergency venting or pressure/vacuum relief for...

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... specified: (1) For tanks built to API Specification 12F, API Standard 620, and others (such as API Standard... accordance with section 4.3.2.3.1. (2) For tanks built to API 2510, the installation of impoundment must be in accordance with section 5 or 11 of API 2510 (incorporated by reference, see § 195.3). (c...

  10. 49 CFR 195.264 - Impoundment, protection against entry, normal/emergency venting or pressure/vacuum relief for...

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... specified: (1) For tanks built to API Specification 12F, API Standard 620, and others (such as API Standard... accordance with section 4.3.2.3.1. (2) For tanks built to API 2510, the installation of impoundment must be in accordance with section 5 or 11 of API 2510 (incorporated by reference, see § 195.3). (c...

  11. 49 CFR 195.264 - Impoundment, protection against entry, normal/emergency venting or pressure/vacuum relief for...

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... specified: (1) For tanks built to API Specification 12F, API Standard 620, and others (such as API Standard... accordance with section 4.3.2.3.1. (2) For tanks built to API 2510, the installation of impoundment must be in accordance with section 5 or 11 of API 2510 (incorporated by reference, see § 195.3). (c...

  12. Speciation and characterization of arsenic in gold ores and cyanidation tailings using X-ray absorption spectroscopy

    USGS Publications Warehouse

    Paktunc, D.; Foster, A.; Heald, S.; Laflamme, G.

    2004-01-01

    . Correlation of Ca with As in iron (III) oxyhydroxides as determined by electron microprobe analysis supports the coprecipitate origin for the presence of Ca in iron (III) oxyhydroxides. The samples containing higher abundances of ferric arsenates released higher As concentrations during the cyanidation tests. The presence of highly soluble ferric arsenates and Ca-Fe arsenates, and relatively unstable iron (III) oxyhydroxides with Fe/As molar ratios of less than 4 in the ore and process tailings suggests that not only the tailings in the impoundment will continue to release As, but also there is the potential for mobilization of As from the natural sources such as the unmined ore. ?? 2004 Elsevier Ltd.

  13. Speciation and characterization of arsenic in gold ores and cyanidation tailings using X-ray absorption spectroscopy

    NASA Astrophysics Data System (ADS)

    Paktunc, Dogan; Foster, Andrea; Heald, Steve; Laflamme, Gilles

    2004-03-01

    ) oxyhydroxides. Correlation of Ca with As in iron (III) oxyhydroxides as determined by electron microprobe analysis supports the coprecipitate origin for the presence of Ca in iron (III) oxyhydroxides. The samples containing higher abundances of ferric arsenates released higher As concentrations during the cyanidation tests. The presence of highly soluble ferric arsenates and Ca-Fe arsenates, and relatively unstable iron (III) oxyhydroxides with Fe/As molar ratios of less than 4 in the ore and process tailings suggests that not only the tailings in the impoundment will continue to release As, but also there is the potential for mobilization of As from the natural sources such as the unmined ore.

  14. Experimental study of solute transport in pool-pipe system and its significance on karst hydrogeology

    NASA Astrophysics Data System (ADS)

    Zhao, X.; Chang, Y.; Peng, F.; Wu, J.

    2016-12-01

    Study of solute transport in karst conduit is of great significance for prediction and prevention of groundwater pollution in southwest karst region. Solute transport in karst conduit is strongly influenced by pools which often develop along karst conduit. In order to investigate the effect of transient storage within pools on solute transport in the conduit, a pool-pipe system was built in the laboratory and some tracer tests were performed in various flow conditions to characterize the solute transport in different pool-pipe structures. The Qtracer2 program was used to obtain solute transport parameters. We used retardation coefficient R to characterize the difference between the 1-D analytical solution of the classical advection-dispersion equation and experimental results. The experimental results reveal that the concentration peak decreases with the number of pools whereas the dispersion coefficient and dispersivity increase gradually. Adding transient storage increases retardation as tailing of the breakthrough curve(BTC) is growing with the number of pools. This demonstrates that transient storage within pools is transformed to retardation. The symmetrical pool has longer tails compared to the asymmetrical pool. The concentration peak lag behind significantly due to the asymmetrical pool. A decrease in dispersivity and tailing of the BTC is observed in all pipes with the increase of flow velocities. The 1-D analytical solution of the classical advection-dispersion equation is well fitted to BTC of a single pipe in maximum flow velocity but is poorly fitted to other BTCs with appreciable tails. Therefore, it requires an appropriate model to explain tailing of the BTC. The conclusion has important significance for understanding of solute transport process in karst conduit. Future work will focus on using the appropriate model to explain tailing of the BTC.

  15. TIDAL TAILS OF MINOR MERGERS. II. COMPARING STAR FORMATION IN THE TIDAL TAILS OF NGC 2782

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Knierman, Karen A.; Scowen, Paul; Veach, Todd

    2013-09-10

    The peculiar spiral NGC 2782 is the result of a minor merger with a mass ratio {approx}4: 1 occurring {approx}200 Myr ago. This merger produced a molecular and H I-rich, optically bright eastern tail and an H I-rich, optically faint western tail. Non-detection of CO in the western tail by Braine et al. suggested that star formation had not yet begun. However, deep UBVR and H{alpha} narrowband images show evidence of recent star formation in the western tail, though it lacks massive star clusters and cluster complexes. Using Herschel PACS spectroscopy, we discover 158 {mu}m [C II] emission at themore » location of the three most luminous H{alpha} sources in the eastern tail, but not at the location of the even brighter H{alpha} source in the western tail. The western tail is found to have a normal star formation efficiency (SFE), but the eastern tail has a low SFE. The lack of CO and [C II] emission suggests that the western tail H II region may have a low carbon abundance and be undergoing its first star formation. The western tail is more efficient at forming stars, but lacks massive clusters. We propose that the low SFE in the eastern tail may be due to its formation as a splash region where gas heating is important even though it has sufficient molecular and neutral gas to make massive star clusters. The western tail, which has lower gas surface density and does not form high-mass star clusters, is a tidally formed region where gravitational compression likely enhances star formation.« less

  16. THE NARROW X-RAY TAIL AND DOUBLE Hα TAILS OF ESO 137-002 IN A3627

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Zhang, B.; Lin, X. B.; Kong, X.

    2013-11-10

    We present the analysis of a deep Chandra observation of a ∼2 L{sub *} late-type galaxy, ESO 137-002, in the closest rich cluster A3627. The Chandra data reveal a long (∼>40 kpc) and narrow tail with a nearly constant width (∼3 kpc) to the southeast of the galaxy, and a leading edge ∼1.5 kpc from the galaxy center on the upstream side of the tail. The tail is most likely caused by the nearly edge-on stripping of ESO 137-002's interstellar medium (ISM) by ram pressure, compared to the nearly face-on stripping of ESO 137-001 discussed in our previous work. Spectralmore » analysis of individual regions along the tail shows that the gas throughout it has a rather constant temperature, ∼1 keV, very close to the temperature of the tails of ESO 137-001, if the same atomic database is used. The derived gas abundance is low (∼0.2 solar with the single-kT model), an indication of the multiphase nature of the gas in the tail. The mass of the X-ray tail is only a small fraction (<5%) of the initial ISM mass of the galaxy, suggesting that the stripping is most likely at an early stage. However, with any of the single-kT, double-kT, and multi-kT models we tried, the tail is always 'over-pressured' relative to the surrounding intracluster medium (ICM), which could be due to the uncertainties in the abundance, thermal versus non-thermal X-ray emission, or magnetic support in the ICM. The Hα data from the Southern Observatory for Astrophysical Research show a ∼21 kpc tail spatially coincident with the X-ray tail, as well as a secondary tail (∼12 kpc long) to the east of the main tail diverging at an angle of ∼23° and starting at a distance of ∼7.5 kpc from the nucleus. At the position of the secondary Hα tail, the X-ray emission is also enhanced at the ∼2σ level. We compare the tails of ESO 137-001 and ESO 137-002, and also compare the tails to simulations. Both the similarities and differences of the tails pose challenges to the simulations. Several

  17. Ion mobility based on column leaching of South African gold tailings dam with chemometric evaluation.

    PubMed

    Cukrowska, Ewa M; Govender, Koovila; Viljoen, Morris

    2004-07-01

    New column leaching experiments were designed and used as an alternative rapid screening approach to element mobility assessment. In these experiments, field-moist material was treated with an extracting solution to assess the effects of acidification on element mobility in mine tailings. The main advantage of this version of column leaching experiments with partitioned segments is that they give quick information on current element mobility in conditions closely simulating field conditions to compare with common unrepresentative air-dried, sieved samples used for column leaching experiments. Layers from the tailings dump material were sampled and packed into columns. The design of columns allows extracting leachates from each layer. The extracting solutions used were natural (pH 6.8) and acidified (pH 4.2) rainwater. Metals and anions were determined in the leachates. The concentrations of metals (Ca, Mg, Fe, Mn, Al, Cr, Ni, Co, Zn, and Cu) in sample leachates were determined using ICP OES. The most important anions (NO3-, Cl-, and SO4(2)-) were determined using the closed system izotacophoresis ITP analyser. The chemical analytical data from tailings leaching and physico-chemical data from field measurements (including pH, conductivity, redox potential, temperature) were used for chemometric evaluation of element mobility. Principal factor analysis (PFA) was used to evaluate ions mobility from different layers of tailings dump arising from varied pH and redox conditions. It was found that the results from the partitioned column leaching illustrate much better complex processes of metals mobility from tailings dump than the total column. The chemometric data analysis (PFA) proofed the differences in the various layers leachability that are arising from physico-chemical processes due to chemical composition of tailings dump deposit. Copyright 2004 Elsevier Ltd.

  18. Automatic early warning of tail biting in pigs: 3D cameras can detect lowered tail posture before an outbreak

    PubMed Central

    Jack, Mhairi; Futro, Agnieszka; Talbot, Darren; Zhu, Qiming; Barclay, David; Baxter, Emma M.

    2018-01-01

    Tail biting is a major welfare and economic problem for indoor pig producers worldwide. Low tail posture is an early warning sign which could reduce tail biting unpredictability. Taking a precision livestock farming approach, we used Time-of-flight 3D cameras, processing data with machine vision algorithms, to automate the measurement of pig tail posture. Validation of the 3D algorithm found an accuracy of 73.9% at detecting low vs. not low tails (Sensitivity 88.4%, Specificity 66.8%). Twenty-three groups of 29 pigs per group were reared with intact (not docked) tails under typical commercial conditions over 8 batches. 15 groups had tail biting outbreaks, following which enrichment was added to pens and biters and/or victims were removed and treated. 3D data from outbreak groups showed the proportion of low tail detections increased pre-outbreak and declined post-outbreak. Pre-outbreak, the increase in low tails occurred at an increasing rate over time, and the proportion of low tails was higher one week pre-outbreak (-1) than 2 weeks pre-outbreak (-2). Within each batch, an outbreak and a non-outbreak control group were identified. Outbreak groups had more 3D low tail detections in weeks -1, +1 and +2 than their matched controls. Comparing 3D tail posture and tail injury scoring data, a greater proportion of low tails was associated with more injured pigs. Low tails might indicate more than just tail biting as tail posture varied between groups and over time and the proportion of low tails increased when pigs were moved to a new pen. Our findings demonstrate the potential for a 3D machine vision system to automate tail posture detection and provide early warning of tail biting on farm. PMID:29617403

  19. A novel polymer inclusion membrane based method for continuous clean-up of thiocyanate from gold mine tailings water.

    PubMed

    Cho, Youngsoo; Cattrall, Robert W; Kolev, Spas D

    2018-01-05

    Thiocyanate is present in gold mine tailings waters in concentrations up to 1000mgL -1 and this has a serious environmental impact by not allowing water reuse in the flotation of gold ore. This significantly increases the consumption of fresh water and the amount of wastewater discharged in tailings dams. At the same time thiocyanate in tailings waters often leads to groundwater contamination. A novel continuous membrane-based method for the complete clean-up of thiocyanate in concentrations as high as 1000mgL -1 from its aqueous solutions has been developed. It employs a flat sheet polymer inclusion membrane (PIM) of composition 70wt% PVC, 20wt% Aliquat 336 and 10wt% 1-tetradecanol which separates counter-current streams of a feed thiocyanate solution and a 1M NaNO 3 receiving solution. The PIM-based system has been operated continuously for 45days with 99% separation efficiency. The volume of the receiving solution has been drastically reduced by recirculating it and continuously removing thiocyanate by precipitating it with in-situ generated Cu(I). The newly developed PIM-based thiocyanate clean-up method is environmentally friendly in terms of reagent use and inexpensive with respect to both equipment and running costs. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Recovery of the Three-Gorges Reservoir Impoundment Signal from ICESat altimetry and GRACE

    NASA Astrophysics Data System (ADS)

    Carabajal, C. C.; Boy, J.; Luthcke, S. B.; Harding, D. J.; Rowlands, D. D.; Lemoine, F. G.

    2006-12-01

    The Three Gorges Dam along the Yangtze River in China is one of the largest dams in the world. The water impoundment of the Three-Gorges Reservoir started in June 2003, and the volume of water will continuously increase up to about 40 km3 in 2009, over a length of about 600 km. Although water-level changes along the Yangtze River and the Three Gorges Reservoir are measured by in situ water gauges, access to these data can be quite difficult. Estimates of inland water height and extent can also be recovered from altimetry measurements performed from satellite platforms, such as those acquired by the Geoscience laser Altimetry System (GLAS) on board the Ice, Cloud and Land Elevation Satellite (ICESat). ICESat has produced a comprehensive, highly precise, set of along-track elevation measurements, every three months since its launch in 2003, which intersect the Yangtze River along its East-West extent. In addition, the water impoundment of major artificial reservoirs induces variations of global geodetic quantities, such as the gravity field and Earth rotation (Chao, 1995, Boy & Chao, 2002). Water level changes within the reservoir are compared to GRACE (Gravity Recovery And Climate Experiment) recovered water mass changes. In addition, we compare the GRACE observations of mass change in the Yangtze region to hydrological changes computed from different global soil-moisture and snow models, such as GLDAS (Global Land Data Assimilation System).

  1. Nesting habitat relationships of sympatric Crested Caracaras, Red-tailed Hawks, and White-tailed Hawks in South Texas

    USGS Publications Warehouse

    Actkinson, M.A.; Kuvlesky, W.P.; Boal, C.W.; Brennan, L.A.; Hernandez, F.

    2007-01-01

    We quantified nesting-site habitats for sympatric White-tailed Hawks (Buteo albicaudatus) (n = 40), Red-tailed Hawks (B. jamaicensis) (n = 39), and Crested Caracaras (Caracara cheriway) (n = 24) in the Coastal Sand Plain of south Texas. White-tailed Hawks and Crested Caracara nest sites occurred in savannas, whereas Red-tailed Hawk nest sites occurred in woodlands on the edge of savannas. White-tailed Hawk nest sites were in shrubs and trees that were shorter (3.5 ?? 1.0 m) and had smaller canopy diameters (5.5 ?? 2.1 m) than those of Red-tailed Hawks (10.1 ?? 2.0 m, 13.7 ?? 5.8 m) and Crested Caracaras (5.6 ?? 1.7 m, 8.5 ?? 3.5 m). Red-tailed Hawk nest sites had higher woody densities (15.7 ?? 9.6 plants) and more woody cover (84 ?? 19%) than those of White-tailed Hawks (5.6 ?? 5.8 plants, 20 ?? 21%) and Crested Caracaras (9.9 ?? 6.7 plants, 55 ?? 34%). Crested Caracara nest sites were in dense, multi-branched shrubs composed of more living material (97 ?? 3%) than those of White-tailed (88 ?? 18%) and Red-tailed hawks (88 ?? 18%). Nest sites of White-tailed Hawks, Red-tailed Hawks, and Crested Caracaras were similar to random samples from the surrounding habitat indicating that preferred nesting habitat was available for each of these species at least within 60 m of active nest sites. Nest tree height, along with woody plant and native grass cover best discriminated nest sites among the three raptor species. There was no overlap at Red-tailed and White-tailed hawk nest sites in vegetation structure, while Crested Caracara nests were in habitat intermediate between the two other species. Partitioning of nesting habitat may be how these raptor species co-exist at the broader landscape scale of our study area in the Coastal Sand Plain of Texas.

  2. INNOVATIVE CONCEPTS FOR DETECTING AND LOCATING LEAKS IN WASTE IMPOUNDMENT LINER SYSTEMS: ACOUSTIC EMISSION MONITORING AND TIME DOMAIN REFLECTOMETRY

    EPA Science Inventory

    This project is part of a program to investigate the use of innovative techniques for detecting and locating leaks in waste impoundment liners. Laboratory and small scale field studies were undertaken to evaluate the potential of Acoustic Emission Monitoring (AEM) and Time Domain...

  3. Sediment quantity and quality in three impoundments in Massachusetts

    USGS Publications Warehouse

    Zimmerman, Marc James; Breault, Robert F.

    2003-01-01

    As part of a study with an overriding goal of providing information that would assist State and Federal agencies in developing screening protocols for managing sediments impounded behind dams that are potential candidates for removal, the U.S Geological Survey determined sediment quantity and quality at three locations: one on the French River and two on Yokum Brook, a tributary to the west branch of the Westfield River. Data collected with a global positioning system, a geographic information system, and sediment-thickness data aided in the creation of sediment maps and the calculation of sediment volumes at Perryville Pond on the French River in Webster, Massachusetts, and at the Silk Mill and Ballou Dams on Yokum Brook in Becket, Massachusetts. From these data the following sediment volumes were determined: Perryville Pond, 71,000 cubic yards, Silk Mill, 1,600 cubic yards, and Ballou, 800 cubic yards. Sediment characteristics were assessed in terms of grain size and concentrations of potentially hazardous organic compounds and metals. Assessment of the approaches and methods used at study sites indicated that ground-penetrating radar produced data that were extremely difficult and time-consuming to interpret for the three study sites. Because of these difficulties, a steel probe was ultimately used to determine sediment depth and extent for inclusion in the sediment maps. Use of these methods showed that, where sampling sites were accessible, a machine-driven coring device would be preferable to the physically exhausting, manual sediment-coring methods used in this investigation. Enzyme-linked immunosorbent assays were an effective tool for screening large numbers of samples for a range of organic contaminant compounds. An example calculation of the number of samples needed to characterize mean concentrations of contaminants indicated that the number of samples collected for most analytes was adequate; however, additional analyses for lead, copper, silver

  4. Tail Buffeting

    NASA Technical Reports Server (NTRS)

    Abdrashitov, G.

    1943-01-01

    An approximate theory of buffeting is here presented, based on the assumption of harmonic disturbing forces. Two cases of buffeting are considered: namely, for a tail angle of attack greater and less than the stalling angle, respectively. On the basis of the tests conducted and the results of foreign investigators, a general analysis is given of the nature of the forced vibrations the possible load limits on the tail, and the methods of elimination of buffeting.

  5. Water velocity, turbulence, and migration rate of subyearling fall Chinook salmon in the free-flowing and impounded Snake River

    USGS Publications Warehouse

    Tiffan, Kenneth F.; Kock, Tobias J.; Haskell, Craig A.; Connor, William P.; Steinhorst, R. Kirk

    2009-01-01

    We studied the migratory behavior of subyearling fall Chinook salmon Oncorhynchus tshawytscha in free-flowing and impounded reaches of the Snake River to evaluate the hypothesis that velocity and turbulence are the primary causal mechanisms of downstream migration. The hypothesis states that impoundment reduces velocity and turbulence and alters the migratory behavior of juvenile Chinook salmon as a result of their reduced perception of these cues. At a constant flow (m3 /s), both velocity (km/d) and turbulence (the SD of velocity) decreased from riverine to impounded habitat as cross-sectional areas increased. We found evidence for the hypothesis that subyearling Chinook salmon perceive velocity and turbulence cues and respond to these cues by varying their behavior. The percentage of the subyearlings that moved faster than the average current speed decreased as fish made the transition from riverine reaches with high velocities and turbulence to upper reservoir reaches with low velocities and turbulence but increased to riverine levels again as the fish moved further down in the reservoir, where velocity and turbulence remained low. The migration rate (km/d) decreased in accordance with longitudinal reductions in velocity and turbulence, as predicted by the hypothesis. The variation in migration rate was better explained by a repeatedmeasures regression model containing velocity (Akaike’s information criterion ¼ 1,769.0) than a model containing flow (2,232.6). We conclude that subyearling fall Chinook salmon respond to changes in water velocity and turbulence, which work together to affect the migration rate.

  6. Research on Long Tail Recommendation Algorithm

    NASA Astrophysics Data System (ADS)

    Hu, Xuezhi; Zhang, Chuang; Wu, Ming; Zeng, Yang

    2017-10-01

    Most recommendation systems in the major electronic commerce platforms are influenced by the long tail effect more or less. There are sufficient researches of how to assess recommendation effect while no criteria to evaluate long tail recommendation rate. In this study, we first discussed the existing problems of recommending long tail products through specific experiments. Then we proposed a long tail evaluation criteria and compared the performance in long tail recommendation between different models.

  7. Horse impoundments under Control of Horses legislation in the Munster region of Ireland: factors affecting euthanasia.

    PubMed

    Cullinane, M; O'Sullivan, E; Collins, D M; Byrne, A W; More, S J

    2015-01-24

    Recently, considerable international attention has been paid to the problem of unwanted horses. In Ireland, stray horses, particularly in urban areas, are a further problem. The Control of Horses Act 1996 was enacted in response to an ongoing problem of uncontrolled horses in public places. As yet, no research work has been conducted focusing on stray horses in Ireland. This paper describes horses impounded under the Act in the Munster region of Ireland during 2005-2012 and the factors influencing decisions regarding their disposal. A logistic regression model was developed to investigate factors influencing the probability that a horse was euthanised during impoundment. In total, 3625 seizure events were recorded, most towards the end of the study period. Predictors for euthanasia during 2010-2012 included seizure location, sex, age, colour, body condition score and year. This study highlights the problem of stray horses in Ireland, particularly in urban areas. There is a need for rigorous enforcement of newly enacted horse identification legislation, allowing a fully integrated traceability system. More is required to manage the long-established societal problems of stray horses in urban settings, with a uniform approach by all Local Authorities being long overdue. British Veterinary Association.

  8. A Tale of Tails: Dissecting the Enhancing Effect of Tailed Primers in Real-Time PCR

    PubMed Central

    Vandenbussche, Frank; Mathijs, Elisabeth; Lefebvre, David; De Clercq, Kris; Van Borm, Steven

    2016-01-01

    Non-specific tail sequences are often added to the 5’-terminus of primers to improve the robustness and overall performance of diagnostic assays. Despite the widespread use of tailed primers, the underlying working mechanism is not well understood. To address this problem, we conducted a detailed in vitro and in silico analysis of the enhancing effect of primer tailing on 2 well-established foot-and-mouth disease virus (FMDV) RT-qPCR assays using an FMDV reference panel. Tailing of the panFMDV-5UTR primers mainly affected the shape of the amplification curves. Modelling of the raw fluorescence data suggested a reduction of the amplification efficiency due to the accumulation of inhibitors. In depth analysis of PCR products indeed revealed the rapid accumulation of forward-primer derived artefacts. More importantly, tailing of the forward primer delayed artefacts formation and concomitantly restored the sigmoidal shape of the amplification curves. Our analysis also showed that primer tailing can alter utilisation patterns of degenerate primers and increase the number of primer variants that are able to participate in the reaction. The impact of tailed primers was less pronounced in the panFMDV-3D assay with only 5 out of 50 isolates showing a clear shift in Cq values. Sequence analysis of the target region of these 5 isolates revealed several mutations in the inter-primer region that extend an existing hairpin structure immediately downstream of the forward primer binding site. Stabilisation of the forward primer with either a tail sequence or cationic spermine units restored the sensitivity of the assay, which suggests that the enhancing effect in the panFMDV-3D assay is due to a more efficient extension of the forward primer. ur results show that primer tailing can alter amplification through various mechanisms that are determined by both the assay and target region. These findings expand our understanding of primer tailing and should enable a more targeted and

  9. Hydrologic and geochemical data collected near Skewed Reservoir, an impoundment for coal-bed natural gas produced water, Powder River Basin, Wyoming

    USGS Publications Warehouse

    Healy, Richard W.; Rice, Cynthia A.; Bartos, Timothy T.

    2012-01-01

    The Powder River Structural Basin is one of the largest producers of coal-bed natural gas (CBNG) in the United States. An important environmental concern in the Basin is the fate of groundwater that is extracted during CBNG production. Most of this produced water is disposed of in unlined surface impoundments. A 6-year study of groundwater flow and subsurface water and soil chemistry was conducted at one such impoundment, Skewed Reservoir. Hydrologic and geochemical data collected as part of that study are contained herein. Data include chemistry of groundwater obtained from a network of 21 monitoring wells and three suction lysimeters and chemical and physical properties of soil cores including chemistry of water/soil extracts, particle-size analyses, mineralogy, cation-exchange capacity, soil-water content, and total carbon and nitrogen content of soils.

  10. Impact of a subsidized spay neuter clinic on impoundments and euthanasia in a community shelter and on service and complaint calls to animal control.

    PubMed

    Scarlett, Janet; Johnston, Naomi

    2012-01-01

    Reducing the number of homeless, nonhuman animals entering and being euthanatized in community shelters is the principal motivation for most spay/neuter (S/N) programs in the United States. This study evaluated the impact of a subsidized S/N clinic opened in 2005 in Transylvania County, North Carolina, on the numbers of impoundments (and euthanasia) of dogs and cats and on the number of animal-related service and complaint calls at the community's only animal shelter. Before opening the local S/N clinic, a significant linear decline in the shelter's dog-intake rate per 1,000 human population was evident. This decline did not accelerate after the S/N clinic opened in 2005. The rate of decline in euthanasia did level off after the clinic opened, but the proportion of impounded dogs euthanatized did not change significantly. The median number of cats impounded and euthanatized yearly in the Transylvania County Animal Services shelter decreased significantly after the S/N clinic opened; the proportion of cats euthanatized did not change. The median annual number of service calls and complaints decreased or leveled off. Unfortunately, data regarding many factors essential for conclusively interpreting these results were not available.

  11. Runaway tails in magnetized plasmas

    NASA Technical Reports Server (NTRS)

    Moghaddam-Taaheri, E.; Vlahos, L.; Rowland, H. L.; Papadopoulos, K.

    1985-01-01

    The evolution of a runaway tail driven by a dc electric field in a magnetized plasma is analyzed. Depending on the strength of the electric field and the ratio of plasma to gyrofrequency, there are three different regimes in the evolution of the tail. The tail can be (1) stable with electrons accelerated to large parallel velocities, (2) unstable to Cerenkov resonance because of the depletion of the bulk and the formation of a positive slope, (3) unstable to the anomalous Doppler resonance instability driven by the large velocity anisotropy in the tail. Once an instability is triggered (Cerenkov or anomalous Doppler resonance) the tail relaxes into an isotropic distribution. The role of a convection type loss term is also discussed.

  12. Interrelationships between fish tissue mercury concentrations and water quality for South Dakota natural lakes and impoundments

    USGS Publications Warehouse

    Chipps, Steven R.; Stetler, Larry; Stone, James J.; McCutcheon, Cindy M.

    2011-01-01

    The purpose of this study was to determine whether water quality parameters commonly associated with primary productivity may be used to predict the susceptibility of a specific water body to exceed proposed fish consumption advisory limitation of 0.3 mg kg−1. South Dakota currently has nine lakes and impoundments that exceed fish tissue mercury advisory limits of 1.0 mg kg−1 total mercury, far exceeding US Environmental Protection Agency and Food and Drug Administration 0.3 mg kg−1 consumption criteria. Previous studies suggest that increased aquatic productivity may mitigate the effects of biological production and subsequent uptake of methyl mercury through bio-dilution; however, it is uncertain whether these trends may exist within highly alkaline and highly productive aquatic conditions common to South Dakota lakes and impoundments. Water quality parameters and fish tissue mercury data for northern pike and walleye were collected and assessed using existing South Dakota Department of Environment and Natural Resources and Game Fish and Parks data. The data was initially screened using both parametric linear regression and non-parametric Mann–Whitney rank sum comparisons and further assessed using binary logistic regression and stepwise logistic regression methodology. Three separate phosphorus measurements (total, total dissolved, and Trophic State Index) and pH were determined to significantly correlate with increased mercury concentrations for the northern pike-in-impoundments model. However, phosphorus surprisingly was not a strong predictor for the remaining scenarios modeled. For the northern pike-in-natural lakes models, alkalinity was the most significant water quality parameter predicting increased mercury concentrations. Mercury concentrations for the walleye-in-natural lakes models were further influenced by pH and alkalinity. The water quality and fish tissue mercury interrelationships determined within this study suggest aquatic

  13. Water-quality study of Tulpehocken Creek, Berks County, Pennsylvania, prior to impoundment of Blue Marsh Lake

    USGS Publications Warehouse

    Barker, James L.

    1977-01-01

    Blue Marsh Lake is planned as a multipurpose impoundment to be constructed on Tulpehocken Creek near Bernville, Berks County, Pennsylvania. Prior to construction, samples of water, bed material, and soil were collected throughout the impoundment site to determine concentrations of nutrients, insecticides, trace metals, suspended sediment, and bacteria. Analyses of water suggest the Tulpehocken Creek basin to be a highly fertile environment. Nitrogen and phosphorus concentrations near the proposed dam site had median values of 4.5 and 0.13 mg/L, respectively. Suspended sediment discharges average between 100 and 200 tons (90.7 to 181.4 metric tons) per day during normal flows but may exceed 10,000 tons (9,070 metric tons) per day during storm runoff. Highest yields were measured during winter and early spring. Concentrations range from 3 mg/L to more than 500 mg/L. Bed material samples contain trace quantities of aldrin, DDT, DDD, DDE, dieldrin, and chlordane. Polychlorinated biphyenyls (PCB's) ranged from 10 to 100 μg/kg. Soils at the impoundment site are of average fertility. However, the silt loam texture is ideal for attachment and growth of aquatic plants. Bacteria populations indicative of recent fecal contamination are prevalent in the major inflows to the proposed lake. Fecal Coliform exceeded the standards recommended by the Federal Water Pollution Administration Committee on Water Quality Criteria for public water supply in 29 percent of the monthly samples, and exceeded the recommended public bathing waters standard in 83 percent of the samples collected from June to September. Arsenic from an industrial waste was found in the water, suspended sediment, and bed material of Tulpehocken Creek in concentrations of 0 to 30 μg/l, 2 to 879 μg/l, and 1 to 79 μg/g, respectively. It represents a potential environmental hazard; however, the measured concentrations are less than that known to be harmful to man, fish, or wildlife, according to published water

  14. Ring current impoundment of the Io plasma torus

    NASA Technical Reports Server (NTRS)

    Siscoe, G. L.; Thorne, R. M.; Richardson, J. D.; Bagenal, F.; Sullivan, J. D.; Eviatar, A.

    1981-01-01

    A newly discovered feature in the Io plasma formation that may be described as a ramp separating a high-density plasma ledge on its Jupiterward side from the lower-density radially distended Io plasma disc on its anti-Jupiterward side is observed to coincide with a marked inward decrease in the ring current population. The spatial congruency of the counter-directed maximal gradients in both plasma bodies reveals a profound coupling between them. The existence of the ramp requires a local order-of-magnitude reduction in the diffusion coefficient that governs radial mass transport. It is demonstrated that the diminished diffusive efficiency there is caused by strong pressure gradient inhibition of the interchange instability that underlies mass transport. The Io plasma torus, which is defined as the region of strong ultraviolet emissions, is identified as the plasma ledge. The plasma density in the ledge is high and, incidentally therefore, able to emit strongly because it is impounded against rapid, centrifugal expulsion by the inwardly directed pressure of the ring current at its inner edge.

  15. Reestablishing the Dominance of Biogeochemical Pathways for Reducing Downstream Nutrient Losses from Aged Impounded Features

    NASA Astrophysics Data System (ADS)

    Shukla, S.; Shukla, A.

    2017-12-01

    Water and phosphorus (P) dynamics and loss pathways at two stormwater impoundments (SIs) were analyzed using measured fluxes between 2008 and 2011. These SIs are a decade old. Analyses of water and P budgets along with the discernment of various P pools and characterization of the intermediary processes revealed that soil adsorption and plant uptake are secondary to volume reduction apropos of P treatment. At one site, extreme wet conditions in a year combined with soil P saturation resulted in it being a P source rather than a sink. The impoundment (SI-1) discharged 12% more P than incoming due to soil P desorption, a consequence of dilution of incoming stormwater with large water input from an extreme tropical rain event. The second impoundment (SI-2) was a consistent sink of P; 55% and 95% of the incoming total P was retained in the two years, mainly as a result of 49% and 84% volume retention, respectively. Analysis of plant available aluminum, iron, and phosphorus showed the surface soil to be P saturated and at risk of releasing P to a limit of environmental concern. These results when seen in light of more frequent extreme precipitation events under the changed climate scenario call for alternatives to revive the role of biogeochemical processes in P treatment because volume reduction may not always be the viable option, especially for wet conditions. Aboveground biomass harvesting and removal was evaluated to transform the SIs from a frequent P source to sink and maintain the long-term sink functions of the SIs. Use of harvested biomass as a source of nutrients (N and P) and carbon to agricultural soil can result in beneficial use of biomass and offset the cost of harvesting. Other avenues such as altering the hydrology of the SIs by compartmentalizing the system and increasing the storage were also explored for short-term benefits. Results provided a combination of hydraulic and biochemical options for achieving long-term water and nutrient retentions in

  16. Contrasting fish assemblages in free-flowing and impounded tributaries to the Upper Delaware River: Implications for conserving biodiversity

    USGS Publications Warehouse

    Baldigo, Barry P.; Delucia, Mari-Beth; Keller, Walter D.; Schuler, George E.; Apse, Colin D.; Moberg, Tara

    2015-01-01

    The Neversink River and the Beaver Kill in southeastern New York are major tributaries to the Delaware River, the longest undammed river east of the Mississippi. While the Beaver Kill is free flowing for its entire length, the Neversink River is subdivided by the Neversink Reservoir, which likely affects the diversity of local fish assemblages and health of aquatic ecosystems. The reservoir is an important part of the New York City waster-supply system that provides drinking water to more than 9 million people. Fish population and community data from recent quantitative surveys at comparable sites in both basins were assessed to characterize the differences between free-flowing and impounded rivers and the extent of reservoir effects to improve our capacity to define ecosystems responses that two modified flow-release programs (implemented in 2007 and 2011) should produce in the Neversink River. In general, the continuum of changes in fish assemblages which normally occur between headwaters and mouth was relatively uninterrupted in the Beaver Kill, but disrupted by the mid-basin impoundment in the Neversink River. Fish assemblages were also adversely affected at several acidified sites in the upper Neversink River, but not at most sites assessed herein. The reservoir clearly excluded diadromous species from the upper sub-basin, but it also substantially reduced community richness, diversity, and biomass at several mid-basin sites immediately downstream from the impoundment. There results will aid future attempts to determine if fish assemblages respond to more natural, yet highly regulated, flow regimes in the Neversink River. More important, knowledge gained from this study can help optimize use of valuable water resources while promoting species of special concern, such as American eel (Anguilla rostrata) and conserving biodiversity in Catskill Mountain streams.

  17. The new idea of transporting tailings-logs in tailings slurry pipeline and the innovation of technology of mining waste-fill method

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Lin Yu; Wang Fuji; Tao Yan

    2000-07-01

    This paper introduced a new idea of transporting mine tailings-logs in mine tailings-slurry pipeline and a new technology of mine cemented filing of tailings-logs with tailings-slurry. The hydraulic principles, the compaction of tailings-logs and the mechanic function of fillbody of tailings-logs cemented by tailings-slurry have been discussed.

  18. Investigation of the possibility of copper recovery from the flotation tailings by acid leaching.

    PubMed

    Antonijević, M M; Dimitrijević, M D; Stevanović, Z O; Serbula, S M; Bogdanovic, G D

    2008-10-01

    The flotation tailings pond of the Bor Copper Mine poses a great ecological problem not only for the town of Bor but also for the surrounding soils and watercourses. Since the old flotation tailings contain about 0.2% of copper on the average, we investigated their leaching with sulphuric acid in the absence and presence of an oxidant. The aim was to determine the leaching kinetics of copper and iron as affected by various factors such as: the pH value of the leach solution, stirring speed, pulp density, particle size, concentration of ferric ions, temperature and time for leaching. The average copper and iron recovery obtained was from 60% to 70% and from 2% to 3%, respectively. These results indicate that the old flotation tailings pond represents an important source of secondary raw material for the extraction of copper and that it should be valorized rather than land reclamation. At the end of the paper, a mechanism of dissolution of copper and iron minerals from the tailings was described.

  19. Anisotropic distribution function of minority tail ions generated by strong ion-cyclotron resonance heating

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Chang, C.S.; Colestock, P.

    1989-05-01

    The highly anisotropic particle distribution function of minority tail ions driven by ion-cyclotron resonance heating at the fundamental harmonic is calculated in a two-dimensional velocity space. It is assumed that the heating is strong enough to drive most of the resonant ions above the in-electron critical slowing-down energy. Simple analytic expressions for the tail distribution are obtained fro the case when the Doppler effect is sufficiently large to flatten the sharp pitch angle dependence in the bounce averaged qualilinear heating coefficient, D/sub b/, and for the case when D/sub b/ is assumed to be constant in pitch angle and energy.more » It is found that a simple constant-D/sub b/ solution can be used instead of the more complicated sharp-D/sub b/ solution for many analytic purposes. 4 refs., 4 figs.« less

  20. Modeling and statistical analysis of non-Gaussian random fields with heavy-tailed distributions.

    PubMed

    Nezhadhaghighi, Mohsen Ghasemi; Nakhlband, Abbas

    2017-04-01

    In this paper, we investigate and develop an alternative approach to the numerical analysis and characterization of random fluctuations with the heavy-tailed probability distribution function (PDF), such as turbulent heat flow and solar flare fluctuations. We identify the heavy-tailed random fluctuations based on the scaling properties of the tail exponent of the PDF, power-law growth of qth order correlation function, and the self-similar properties of the contour lines in two-dimensional random fields. Moreover, this work leads to a substitution for the fractional Edwards-Wilkinson (EW) equation that works in the presence of μ-stable Lévy noise. Our proposed model explains the configuration dynamics of the systems with heavy-tailed correlated random fluctuations. We also present an alternative solution to the fractional EW equation in the presence of μ-stable Lévy noise in the steady state, which is implemented numerically, using the μ-stable fractional Lévy motion. Based on the analysis of the self-similar properties of contour loops, we numerically show that the scaling properties of contour loop ensembles can qualitatively and quantitatively distinguish non-Gaussian random fields from Gaussian random fluctuations.

  1. Exploring Mercury Tail

    NASA Image and Video Library

    2008-08-26

    As the MESSENGER spacecraft approached Mercury, the UVVS field of view was scanned across the planet's exospheric "tail," which is produced by the solar wind pushing Mercury's exosphere (the planet's extremely thin atmosphere) outward. This figure, recently published in Science magazine, shows a map of the distribution of sodium atoms as they stream away from the planet (see PIA10396); red and yellow colors represent a higher abundance of sodium than darker shades of blue and purple, as shown in the colored scale bar, which gives the brightness intensity in units of kiloRayleighs. The escaping atoms eventually form a comet-like tail that extends in the direction opposite that of the Sun for many planetary radii. The small squares outlined in black correspond to individual measurements that were used to create the full map. These measurements are the highest-spatial-resolution observations ever made of Mercury's tail. In less than six weeks, on October 6, 2008, similar measurements will be made during MESSENGER's second flyby of Mercury. Comparing the measurements from the two flybys will provide an unprecedented look at how Mercury's dynamic exosphere and tail vary with time. Date Acquired: January 14, 2008. http://photojournal.jpl.nasa.gov/catalog/PIA11076

  2. Synchronous response of sedimentary organic carbon accumulation on the inner shelf of the East China Sea to the water impoundment of Three Gorges and Gezhouba Dams

    NASA Astrophysics Data System (ADS)

    Lin, Jia; Zhu, Qing; Hong, Yuehui; Yuan, Lirong; Liu, Jinzhong; Xu, Xiaoming; Wang, Jianghai

    2018-01-01

    Coastal seas, located between continents and the open ocean, are an important active carbon pool. The sedimentary total organic carbon (TOC) in these areas is a mixture of terrestrial and marine sources, and can be a powerful proxy for tracing natural processes and human activities. In this study, one fine-grained sediment core (DH5-1) from the inner shelf of the East China Sea was systematically analyzed for TOC and black carbon (BC) contents and TOC stable carbon isotope ratios (δ13C). By combining these data with 210Pb dating, an improved carbon correction model and a two end-member mixing model, we reconstructed century-scale high-resolution sequences of corrected TOC, terrestrial TOC and marine TOC contents and identified two carbon depletion events in the DH5-1 record. The two events, shown as two minima in the TOC profiles, correspond temporally to 1985-1987 AD and 2003-2006 AD, which exactly matches the water impoundment of the Gezhouba Dam and Three Gorges Dam, respectively. In addition, the variations in TOC contents and δ13C values before, during or after the minima demonstrate a relationship between the depletion events and water impoundment of the dams on the Changjiang River. The TOC reductions may represent synchronous responses of sedimentary TOC and resultant ecological effects on the inner shelf of the East China Sea to the water impoundment of the dams. These new TOC records reflect the interaction between natural and anthropogenic processes and, accordingly, provide a deep insight and important references for assessing marine ecological effects resulting from water impoundment of largescale dams.

  3. Metal loading in Soda Butte Creek upstream of Yellowstone National Park, Montana and Wyoming; a retrospective analysis of previous research; and quantification of metal loading, August 1999

    USGS Publications Warehouse

    Boughton, G.K.

    2001-01-01

    Acid drainage from historic mining activities has affected the water quality and aquatic biota of Soda Butte Creek upstream of Yellowstone National Park. Numerous investigations focusing on metals contamination have been conducted in the Soda Butte Creek basin, but interpretations of how metals contamination is currently impacting Soda Butte Creek differ greatly. A retrospective analysis of previous research on metal loading in Soda Butte Creek was completed to provide summaries of studies pertinent to metal loading in Soda Butte Creek and to identify data gaps warranting further investigation. Identification and quantification of the sources of metal loading to Soda Butte Creek was recognized as a significant data gap. The McLaren Mine tailings impoundment and mill site has long been identified as a source of metals but its contribution relative to the total metal load entering Yellowstone National Park was unknown. A tracer-injection and synoptic-sampling study was designed to determine metal loads upstream of Yellowstone National Park.A tracer-injection and synoptic-sampling study was conducted on an 8,511-meter reach of Soda Butte Creek from upstream of the McLaren Mine tailings impoundment and mill site downstream to the Yellowstone National Park boundary in August 1999. Synoptic-sampling sites were selected to divide the creek into discrete segments. A lithium bromide tracer was injected continuously into Soda Butte Creek for 24.5 hours. Downstream dilution of the tracer and current-meter measurements were used to calculate the stream discharge. Stream discharge values, combined with constituent concentrations obtained by synoptic sampling, were used to quantify constituent loading in each segment of Soda Butte Creek.Loads were calculated for dissolved calcium, silica, and sulfate, as well as for dissolved and total-recoverable iron, aluminum, and manganese. Loads were not calculated for cadmium, copper, lead, and zinc because these elements were infrequently

  4. Tail-scope: Using friends to estimate heavy tails of degree distributions in large-scale complex networks

    NASA Astrophysics Data System (ADS)

    Eom, Young-Ho; Jo, Hang-Hyun

    2015-05-01

    Many complex networks in natural and social phenomena have often been characterized by heavy-tailed degree distributions. However, due to rapidly growing size of network data and concerns on privacy issues about using these data, it becomes more difficult to analyze complete data sets. Thus, it is crucial to devise effective and efficient estimation methods for heavy tails of degree distributions in large-scale networks only using local information of a small fraction of sampled nodes. Here we propose a tail-scope method based on local observational bias of the friendship paradox. We show that the tail-scope method outperforms the uniform node sampling for estimating heavy tails of degree distributions, while the opposite tendency is observed in the range of small degrees. In order to take advantages of both sampling methods, we devise the hybrid method that successfully recovers the whole range of degree distributions. Our tail-scope method shows how structural heterogeneities of large-scale complex networks can be used to effectively reveal the network structure only with limited local information.

  5. 25 CFR 166.808 - How are trespassers notified if their unauthorized livestock or other property are to be impounded?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ..., DEPARTMENT OF THE INTERIOR LAND AND WATER GRAZING PERMITS Trespass Actions § 166.808 How are trespassers notified if their unauthorized livestock or other property are to be impounded? (a) If the trespass is not corrected in the time specified in the initial trespass notice, we will send written notice of our intent to...

  6. 25 CFR 166.808 - How are trespassers notified if their unauthorized livestock or other property are to be impounded?

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ..., DEPARTMENT OF THE INTERIOR LAND AND WATER GRAZING PERMITS Trespass Actions § 166.808 How are trespassers notified if their unauthorized livestock or other property are to be impounded? (a) If the trespass is not corrected in the time specified in the initial trespass notice, we will send written notice of our intent to...

  7. 25 CFR 166.808 - How are trespassers notified if their unauthorized livestock or other property are to be impounded?

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ..., DEPARTMENT OF THE INTERIOR LAND AND WATER GRAZING PERMITS Trespass Actions § 166.808 How are trespassers notified if their unauthorized livestock or other property are to be impounded? (a) If the trespass is not corrected in the time specified in the initial trespass notice, we will send written notice of our intent to...

  8. 25 CFR 166.808 - How are trespassers notified if their unauthorized livestock or other property are to be impounded?

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ..., DEPARTMENT OF THE INTERIOR LAND AND WATER GRAZING PERMITS Trespass Actions § 166.808 How are trespassers notified if their unauthorized livestock or other property are to be impounded? (a) If the trespass is not corrected in the time specified in the initial trespass notice, we will send written notice of our intent to...

  9. 25 CFR 166.808 - How are trespassers notified if their unauthorized livestock or other property are to be impounded?

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ..., DEPARTMENT OF THE INTERIOR LAND AND WATER GRAZING PERMITS Trespass Actions § 166.808 How are trespassers notified if their unauthorized livestock or other property are to be impounded? (a) If the trespass is not corrected in the time specified in the initial trespass notice, we will send written notice of our intent to...

  10. Does climate have heavy tails?

    NASA Astrophysics Data System (ADS)

    Bermejo, Miguel; Mudelsee, Manfred

    2013-04-01

    When we speak about a distribution with heavy tails, we are referring to the probability of the existence of extreme values will be relatively large. Several heavy-tail models are constructed from Poisson processes, which are the most tractable models. Among such processes, one of the most important are the Lévy processes, which are those process with independent, stationary increments and stochastic continuity. If the random component of a climate process that generates the data exhibits a heavy-tail distribution, and if that fact is ignored by assuming a finite-variance distribution, then there would be serious consequences (in the form, e.g., of bias) for the analysis of extreme values. Yet, it appears that it is an open question to what extent and degree climate data exhibit heavy-tail phenomena. We present a study about the statistical inference in the presence of heavy-tail distribution. In particular, we explore (1) the estimation of tail index of the marginal distribution using several estimation techniques (e.g., Hill estimator, Pickands estimator) and (2) the power of hypothesis tests. The performance of the different methods are compared using artificial time-series by means of Monte Carlo experiments. We systematically apply the heavy tail inference to observed climate data, in particular we focus on time series data. We study several proxy and directly observed climate variables from the instrumental period, the Holocene and the Pleistocene. This work receives financial support from the European Commission (Marie Curie Initial Training Network LINC, No. 289447, within the 7th Framework Programme).

  11. Tectonic state: its significance and characterization in the assessment of seismic effects associated with reservoir impounding

    USGS Publications Warehouse

    Castle, R.O.; Clark, M.M.; Grantz, A.; Savage, J.C.

    1980-01-01

    Any analysis of seismicity associated with the filling of large reservoirs requires an evaluation of the natural tectonic state in order to determine whether impoundment is the basic source, a mechanically unrelated companion feature, or a triggering stimulus of the observed seismicity. Several arguments indicate that the associated seismicity is usually a triggered effect. Among the elements of tectonic state considered here (existing fractures, accumulated elastic strain, and deformational style), deformational style is especially critical in forecasting the occurrence of impoundment-induced seismicity. The observational evidence indicates that seismicity associated with impounding generally occurs in areas that combine steeply dipping faults, relatively high strain rates, and either extensional or horizontal-shear strain. Simple physical arguments suggest: (1) that increased fluid pressures resulting from increased reservoir head should enhance the likelihood of seismic activity, whatever the tectonic environment; (2) that stress changes resulting from surface loading may increase the likelihood of crustal failure in areas of normal and transcurrent faulting, whereas they generally inhibit failure in areas of thrust faulting. Comparisons with other earthquake-producing artificial and natural processes (underground explosions, fluid injection, underground mining, fluid extraction, volcanic emissions) indicate that reservoir loading may similarly modify the natural tectonic state. Subsurface loading resulting from fluid extraction may be a particularly close analogue of reservoir loading; "seismotectonic" events associated with fluid extraction have been recognized in both seismically active and otherwise aseismic regions. Because the historic record of seismicity and surface faulting commonly is short in comparison with recurrence intervals of earthquake and fault-slip events, tectonic state is most reliably appraised through combined studies of historic

  12. Feasible conversion of solid waste bauxite tailings into highly crystalline 4A zeolite with valuable application.

    PubMed

    Ma, Dongyang; Wang, Zhendong; Guo, Min; Zhang, Mei; Liu, Jingbo

    2014-11-01

    Bauxite tailings are a major type of solid wastes generated in the flotation process. The waste by-products caused significant environmental impact. To lessen this hazardous effect from poisonous mine tailings, a feasible and cost-effective solution was conceived and implemented. Our approach focused on reutilization of the bauxite tailings by converting it to 4A zeolite for reuse in diverse applications. Three steps were involved in the bauxite conversion: wet-chemistry, alkali fusion, and crystallization to remove impurities and to prepare porous 4A zeolite. It was found that the cubic 4A zeolite was single phase, in high purity, with high crystallinity and well-defined structure. Importantly, the 4A zeolite displayed maximum calcium ion exchange capacity averaged at 296 mg CaCO3/g, comparable to commercially-available zeolite (310 mg CaCO3/g) exchange capacity. Base on the optimal synthesis condition, the reaction yield of zeolite 4A from bauxite tailings achieved to about 38.43%, hence, this study will provide a new paradigm for remediation of bauxite tailings, further mitigating the environmental and health care concerns, particularly in the mainland of PR China. Copyright © 2014 Elsevier Ltd. All rights reserved.

  13. Active tails enhance arboreal acrobatics in geckos

    PubMed Central

    Jusufi, Ardian; Goldman, Daniel I.; Revzen, Shai; Full, Robert J.

    2008-01-01

    Geckos are nature's elite climbers. Their remarkable climbing feats have been attributed to specialized feet with hairy toes that uncurl and peel in milliseconds. Here, we report that the secret to the gecko's arboreal acrobatics includes an active tail. We examine the tail's role during rapid climbing, aerial descent, and gliding. We show that a gecko's tail functions as an emergency fifth leg to prevent falling during rapid climbing. A response initiated by slipping causes the tail tip to push against the vertical surface, thereby preventing pitch-back of the head and upper body. When pitch-back cannot be prevented, geckos avoid falling by placing their tail in a posture similar to a bicycle's kickstand. Should a gecko fall with its back to the ground, a swing of its tail induces the most rapid, zero-angular momentum air-righting response yet measured. Once righted to a sprawled gliding posture, circular tail movements control yaw and pitch as the gecko descends. Our results suggest that large, active tails can function as effective control appendages. These results have provided biological inspiration for the design of an active tail on a climbing robot, and we anticipate their use in small, unmanned gliding vehicles and multisegment spacecraft. PMID:18347344

  14. Mobilization and transport of metal-rich colloidal particles from mine tailings into soil under transient chemical and physical conditions.

    PubMed

    Lu, Cong; Wu, Yaoguo; Hu, Sihai; Raza, Muhammad Ali; Fu, Yilin

    2016-04-01

    Exposed mine tailing wastes with considerable heavy metals can release hazardous colloidal particles into soil under transient chemical and physical conditions. Two-layered packed columns with tailings above and soils below were established to investigate mobilization and transport of colloidal particles from metal-rich mine tailings into soil under transient infiltration ionic strength (IS: 100, 20, 2 mM) and flow rate (FR: 20.7, 41, and 62.3 mm h(-1)), with Cu and Pb as representatives of the heavy metals. Results show that the tailing particles within the colloidal size (below 2 μm) were released from the columns. A step-decrease in infiltration IS and FR enhanced, whereas a step-increase in the IS and FR restrained the release of tailing particles from the column. The effects of step-changing FR were unexpected due to the small size of the released tailing particles (220-342 nm, being not sensitive to hydrodynamic shear force), the diffusion-controlled particle release process and the relatively compact pore structure. The tailing particles present in the solution with tested IS were found negatively charged and more stable than soil particles, which provides favorable conditions for tailing particles to be transported over a long distance in the soil. The mobilization and transport of Cu and Pb from the tailings into soil were mediated by the tailing particles. Therefore, the inherent toxic tailing particles could be considerably introduced into soil under certain conditions (IS reduction or FR decrease), which may result in serious environmental pollution.

  15. A risk assessment approach to manage inundation of Elseya albagula nests in impounded waters: a win-win situation?

    PubMed

    McDougall, A J; Espinoza, T; Hollier, C; Limpus, D J; Limpus, C J

    2015-03-01

    A risk assessment process was used to trial the impact of potential new operating rules on the frequency of nest inundation for the White-throated snapping turtle, Elseya albagula, in the impounded waters of the Burnett River, Queensland, Australia. The proposed operating rules would increase the barrage storage level during the turtle nesting season (May-July) and then would be allowed to reduce to a lower level for incubation for the rest of the year. These proposed operating rules reduce rates of nest inundation by altering water levels in the Ben Anderson Barrage impoundment of the Burnett River. The rules operate throughout the turtle reproductive period and concomitantly improve stability of littoral habitat and fishway operation. Additionally, the proposed rules are expected to have positive socio-economic benefits within the region. While regulated water resources will inherently have a number of negative environmental implications, these potential new operating rules have the capacity to benefit the environment while managing resources in a more sustainable manner. The operating rules have now been enacted in subordinate legislation and require the operator to maintain water levels to minimize turtle nest inundation.

  16. A Risk Assessment Approach to Manage Inundation of Elseya albagula Nests in Impounded Waters: A Win-Win Situation?

    NASA Astrophysics Data System (ADS)

    McDougall, A. J.; Espinoza, T.; Hollier, C.; Limpus, D. J.; Limpus, C. J.

    2015-03-01

    A risk assessment process was used to trial the impact of potential new operating rules on the frequency of nest inundation for the White-throated snapping turtle, Elseya albagula, in the impounded waters of the Burnett River, Queensland, Australia. The proposed operating rules would increase the barrage storage level during the turtle nesting season (May-July) and then would be allowed to reduce to a lower level for incubation for the rest of the year. These proposed operating rules reduce rates of nest inundation by altering water levels in the Ben Anderson Barrage impoundment of the Burnett River. The rules operate throughout the turtle reproductive period and concomitantly improve stability of littoral habitat and fishway operation. Additionally, the proposed rules are expected to have positive socio-economic benefits within the region. While regulated water resources will inherently have a number of negative environmental implications, these potential new operating rules have the capacity to benefit the environment while managing resources in a more sustainable manner. The operating rules have now been enacted in subordinate legislation and require the operator to maintain water levels to minimize turtle nest inundation.

  17. Comparison of the breeding biology of sympatric red-tailed Hawks, White-tailed Hawks, and Crested Caracaras in south Texas

    USGS Publications Warehouse

    Actkinson, M.A.; Kuvlesky, W.P.; Boal, C.W.; Brennan, L.A.; Hernandez, F.

    2009-01-01

    We compared the breeding biology of sympatric nesting Red-tailed Hawks (Buteo jamaicensis), White-tailed Hawks (Buteo albicaudatus), and Crested Caracaras (Caracara cheriway) in south Texas during 2003 and 2004. We monitored 46 breeding attempts by Red-tailed Hawks, 56 by White-tailed Hawks, and 27 by Crested Caracaras. Observed nesting success was similar for Red-tailed Hawks (62%) and Crested Caracaras (61%), but lower for White-tailed Hawks (51%). Daily survival rates (0.99) were the same for all three species. Red-tailed Hawks and White-tailed Hawks both fledged 1.13 young per nesting pair and Crested Caracaras fledged 1.39 young per nesting pair. All three species nested earlier in 2004 than in 2003; in addition, the overall nesting density of these three species almost doubled from 2003 (1.45 pairs/km2) to 2004 (2.71 pairs/km2). Estimated productivity of all three species was within the ranges reported from other studies. Given extensive and progressive habitat alteration in some areas of south Texas, and the limited distributions of White-tailed Hawks and Crested Caracaras, the presence of large ranches managed for free-range cattle production and hunting leases likely provides important habitat and may be key areas for conservation of these two species. ?? 2009 The Raptor Research Foundation, Inc.

  18. Microcrustaceans (Branchipoda and Copepoda) of Wetland Impoundments on the Savannah River Site, Aiken, South Carolina

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    DeBiase, Adrienne E; Taylor, Barbara E

    2005-09-21

    The United States Department of Energy’s Savannah River Site (SRS) in Aiken, Allendale, and Barnwell Counties, South Carolina, contains an abundance of freshwater wetlands and impoundments. Four large impoundments, as well as several small, abandoned farm and mill ponds, and about 400 Carolina bays and other small, isolated depression wetland ponds are located within the 893 km2 area of the SRS. Crustaceans of the orders Branchiopoda and Copepoda are nearly ubiquitous in these water bodies. Although small in size, these organisms are often very abundant. They consequently play an important trophic role in freshwater food webs supporting fish, larval salamanders,more » larval insects, and numerous other animals, aquatic and terrestrial. This report provides an introduction to the free-living microcrustaceans of lentic water bodies on the SRS and a comprehensive list of species known to occur there. Occurrence patterns are summarized from three extensive survey studies, supplemented with other published and unpublished records. In lieu of a key, we provide a guide to taxonomic resources and notes on undescribed species. Taxa covered include the orders Cladocera, Anostraca, Laevicaudata, and Spinicaudata of the Subclass Branchiopoda and the Superorders Calanoida and Cyclopoida of Subclass Copepoda. Microcrustaceans of the Superorder Harpacticoida of the Subclass Copepoda and Subclass Ostracoda are also often present in lentic water bodies. They are excluded from this report because they have not received much study at the species level on the SRS.« less

  19. Ecotoxicity of Mine Tailings: Unrehabilitated Versus Rehabilitated.

    PubMed

    Maboeta, M S; Oladipo, O G; Botha, S M

    2018-05-01

    Earthworms are bioindicators of soil pollution. The ecotoxicity of tailings from selected gold mines in South Africa was investigated utilizing Eisenia andrei bioassays and biomarkers. Samples were obtained from unrehabilitated, rehabilitated and naturally vegetated sites. Biomass, neutral red retention time (NRRT), survival and reproduction were assessed using standardized protocols. Earthworm biomass, NRRT and reproductive success in rehabilitated tailings (comparable to naturally vegetated site) were significantly higher (p < 0.05) than in unrehabilitated tailings. In addition, significantly lower (p < 0.05) body tissue concentrations of As, Cd, Co, Cu and Ni contents were found in the rehabilitated tailings compared to the unrehabilitated. Further, significantly lower (p < 0.05) soil Mn and Zn concentrations were obtained in unrehabilitated tailings than the rehabilitated and naturally vegetated sites. Overall, reduced ecotoxicity effects were confirmed in rehabilitated compared to unrehabilitated tailings. This suggests that rehabilitation as a post-mining restorative strategy has strong positive influence on mine tailings.

  20. Dissolved carbon dynamics in large boreal rivers from eastern Canada following their impoundment

    NASA Astrophysics Data System (ADS)

    Helie, J.; Rosa, E.; Lalonde, A.; Hillaire-Marcel, C.

    2009-12-01

    The carbon cycling in Canadian boreal environments is the focus of a growing number of investigations mainly because of the importance of hydropower and its potential in the area. Here, we document the behaviour of dissolved inorganic and organic carbon as well as particulate organic carbon (DIC-DOC-POC henceforth) in 5 impounded and 2 pristine river systems (respectively: La Grande 3400 m 3s-1, Eastmain 990 m3s-1, St. Lawrence 12 100 m3s-1, Ottawa 1950 m3s-1, Nelson 2370 m3s-1; Great Whales 680 m3s-1 and Koksoak 1895 m3s-1) river systems. These major rivers were sampled monthly at their outlet for one year except at the St. Lawrence River that has been sampled since June of 1997 on a bi-weekly basis. Complementary synoptic surveys were undertaken in August 2008 on the La Grande and Great Whales Rivers. When sampling, water temperature, pH, alkalinity and specific conductivity were measured. Samples were collected for the analysis of i) major ions concentrations; ii) δ13C and concentration of DIC, DOC and POC); iii) δ18O and δ2H of the water molecule; and iv) U series and Sr isotopes. In all the sampled river systems, POC concentrations were at least an order of magnitude smaller than the dissolved forms. Rivers draining carbonates bedrocks (St.Lawrence and Nelson Rivers) present higher concentrations and δ13C-DIC values linked to carbonate dissolution in soils. Conversely, rivers draining silicate-rich watersheds present lower δ13C- DIC values linked to the production of an isotopically light CO2 through oxidation of organic matter in soils and that of soil-derived DOC along river courses. However, isotopic composition of DIC in impounded rivers draining silicate catchments indicate significant CO2 degassing and some isotopic exchange with atmospheric CO2 in reservoirs. A relatively strong relationship is observed between pCO2 and δ13C-DIC across the studied river systems suggesting a continuum between the production of CO2 through DOM oxidation and CO2

  1. Evaluating the effect of vehicle impoundment policy on illegal construction and demolition waste dumping: Israel as a case study.

    PubMed

    Seror, Nissim; Hareli, Shlomo; Portnov, Boris A

    2014-08-01

    Construction and demolition (C&D) waste dumped alongside roads and in open areas is a major source of soil and underground water pollution. Since 2006, Israeli ministry for environmental protection enacted a policy of vehicle impoundment (VI) according to which track drivers caught while dumping C&D waste illegally have their vehicles impounded. The present study attempted to determine whether the VI policy was effective in increasing the waste hauling to authorized landfill sites, thus limiting the number of illegal unloads of C&D waste at unauthorized landfill sites and in open areas. During the study, changes in the ratio between the monthly amount of C&D waste brought to authorized landfills sites and the estimated total amount of C&D waste generated in different administrative districts of Israel were examined, before and after the enactment of the 2006 VI policy. Short questionnaires were also distributed among local track drivers in order to determine the degree of awareness about the policy in question and estimate its deterrence effects. According to the study's results, in the district of Haifa, in which the VI policy was stringently enacted, the ratio between C&D waste, dumped in authorized landfill sites, and the total amount of generated C&D waste, increased, on the average, from 20% in January 2004 to 35% in October 2009, with the effect attributed to the number of vehicle impoundments being highly statistically significant (t=2.324; p<0.05). By contrast, in the Jerusalem and Southern districts, in which the VI policy was less stringently enforced, the effect of VI on the above ratio was found to be insignificant (p>0.1). The analysis of the questionnaires, distributed among the local truck drivers further indicated that the changes observed in the district of Haifa are not coincident and appeared to be linked to the VI policy's enactment. In particular, 62% of the truck drivers, participated in the survey, were aware of the policy and 47% of them

  2. Development of copper recovery process from flotation tailings by a combined method of high‒pressure leaching‒solvent extraction.

    PubMed

    Han, Baisui; Altansukh, Batnasan; Haga, Kazutoshi; Stevanović, Zoran; Jonović, Radojka; Avramović, Ljiljana; Urosević, Daniela; Takasaki, Yasushi; Masuda, Nobuyuki; Ishiyama, Daizo; Shibayama, Atsushi

    2018-06-15

    Sulfide copper mineral, typically Chalcopyrite (CuFeS 2 ), is one of the most common minerals for producing metallic copper via the pyrometallurgical process. Generally, flotation tailings are produced as a byproduct of flotation and still consist of un‒recovered copper. In addition, it is expected that more tailings will be produced in the coming years due to the increased exploration of low‒grade copper ores. Therefore, this research aims to develop a copper recovery process from flotation tailings using high‒pressure leaching (HPL) followed by solvent extraction. Over 94.4% copper was dissolved from the sample (CuFeS 2 as main copper mineral) by HPL in a H 2 O media in the presence of pyrite, whereas the iron was co‒dissolved with copper according to an equation given as C Cu  = 38.40 × C Fe . To avoid co‒dissolved iron giving a negative effect on the subsequent process of electrowinning, solvent extraction was conducted on the pregnant leach solution for improving copper concentration. The result showed that 91.3% copper was recovered in a stripped solution and 98.6% iron was removed under the optimal extraction conditions. As a result, 86.2% of copper was recovered from the concentrate of flotation tailings by a proposed HPL‒solvent extraction process. Copyright © 2018 Elsevier B.V. All rights reserved.

  3. Assessing Risks of Mine Tailing Dam Failures

    NASA Astrophysics Data System (ADS)

    Concha Larrauri, P.; Lall, U.

    2017-12-01

    The consequences of tailings dam failures can be catastrophic for communities and ecosystems in the vicinity of the dams. The failure of the Fundão tailings dam at the Samarco mine in 2015 killed 19 people with severe consequences for the environment. The financial and legal consequences of a tailings dam failure can also be significant for the mining companies. For the Fundão tailings dam, the company had to pay 6 billion dollars in fines and twenty-one executives were charged with qualified murder. There are tenths of thousands of active, inactive, and abandoned tailings dams in the world and there is a need to better understand the hazards posed by these structures to downstream populations and ecosystems. A challenge to assess the risks of tailings dams in a large scale is that many of them are not registered in publicly available databases and there is little information about their current physical state. Additionally, hazard classifications of tailings dams - common in many countries- tend to be subjective, include vague parameter definitions, and are not always updated over time. Here we present a simple methodology to assess and rank the exposure to tailings dams using ArcGIS that removes subjective interpretations. The method uses basic information such as current dam height, storage volume, topography, population, land use, and hydrological data. A hazard rating risk was developed to compare the potential extent of the damage across dams. This assessment provides a general overview of what in the vicinity of the tailings dams could be affected in case of a failure and a way to rank tailings dams that is directly linked to the exposure at any given time. One hundred tailings dams in Minas Gerais, Brazil were used for the test case. This ranking approach could inform the risk management strategy of the tailings dams within a company, and when disclosed, it could enable shareholders and the communities to make decisions on the risks they are taking.

  4. Active Tails Enhance Arboreal Acrobatics in Geckos

    DTIC Science & Technology

    2008-03-18

    the secret to the gecko s arboreal acrobatics includes an active tail. We examine the tail s role during rapid climbing, aerial descent, and gliding. We show that a gecko s tail functions as an emergency fifth leg to prevent falling during rapid climbing. A response initiated by slipping causes the tail tip to push against the vertical surface, thereby preventing pitch-back of the head and upper body. When pitch-back cannot be prevented, geckos avoid falling by placing their tail in a posture similar to a bicycle s kickstand. Should a gecko fall with its back to the

  5. A cis-prenyltransferase from Methanosarcina acetivorans catalyzes both head-to-tail and nonhead-to-tail prenyl condensation.

    PubMed

    Ogawa, Takuya; Emi, Koh-Ichi; Koga, Kazushi; Yoshimura, Tohru; Hemmi, Hisashi

    2016-06-01

    Cis-prenyltransferase usually consecutively catalyzes the head-to-tail condensation reactions of isopentenyl diphosphate to allylic prenyl diphosphate in the production of (E,Z-mixed) polyprenyl diphosphate, which is the precursor of glycosyl carrier lipids. Some recently discovered homologs of the enzyme, however, catalyze the nonhead-to-tail condensation reactions between allylic prenyl diphosphates. In this study, we characterize a cis-prenyltransferase homolog from a methanogenic archaeon, Methanosarcina acetivorans, to obtain information on the biosynthesis of the glycosyl carrier lipids within it. This enzyme catalyzes both head-to-tail and nonhead-to-tail condensation reactions. The kinetic analysis shows that the main reaction of the enzyme is consecutive head-to-tail prenyl condensation reactions yielding polyprenyl diphosphates, while the chain lengths of the major products seem shorter than expected for the precursor of glycosyl carrier lipids. On the other hand, a subsidiary reaction of the enzyme, i.e., nonhead-to-tail condensation between dimethylallyl diphosphate and farnesyl diphosphate, gives a novel diterpenoid compound, geranyllavandulyl diphosphate. © 2016 Federation of European Biochemical Societies.

  6. Laboratory experiments on dam-break flow of water-sediment mixtures

    USDA-ARS?s Scientific Manuscript database

    Dams induce sedimentation and store significant amounts of sediment as they age; therefore, dam failures often involve the release of sediment-laden water to the downstream floodplain. In particular, tailings dams, which are constructed to impound mining wastes, can cause devastating damage when the...

  7. Fishers' knowledge identifies environmental changes and fish abundance trends in impounded tropical rivers.

    PubMed

    Hallwass, Gustavo; Lopes, Priscila F; Juras, Anastácio A; Silvano, Renato A M

    2013-03-01

    The long-term impacts of large hydroelectric dams on small-scale fisheries in tropical rivers are poorly known. A promising way to investigate such impacts is to compare and integrate the local ecological knowledge (LEK) of resource users with biological data for the same region. We analyzed the accuracy of fishers' LEK to investigate fisheries dynamics and environmental changes in the Lower Tocantins River (Brazilian Amazon) downstream from a large dam. We estimated fishers' LEK through interviews with 300 fishers in nine villages and collected data on 601 fish landings in five of these villages, 22 years after the dam's establishment (2006-2008). We compared these two databases with each other and with data on fish landings from before the dam's establishment (1981) gathered from the literature. The data obtained based on the fishers' LEK (interviews) and from fisheries agreed regarding the primary fish species caught, the most commonly used type of fishing gear (gill nets) and even the most often used gill net mesh sizes but disagreed regarding seasonal fish abundance. According to the interviewed fishers, the primary environmental changes that occurred after the impoundment were an overall decrease in fish abundance, an increase in the abundance of some fish species and, possibly, the local extinction of a commercial fish species (Semaprochilodus brama). These changes were corroborated by comparing fish landings sampled before and 22 years after the impoundment, which indicated changes in the composition of fish landings and a decrease in the total annual fish production. Our results reinforce the hypothesis that large dams may adversely affect small-scale fisheries downstream and establish a feasible approach for applying fishers' LEK to fisheries management, especially in regions with a low research capacity.

  8. Ecological aspects of microorganisms inhabiting uranium mill tailings

    USGS Publications Warehouse

    Miller, C.L.; Landa, E.R.; Updegraff, D.M.

    1987-01-01

    Numbers and types of microorganisms in uranium mill tailings were determined using culturing techniques. Arthrobacter were found to be the predominant microorganism inhabiting the sandy tailings, whereas Bacillus and fungi predominated in the slime tailings. Sulfate-reducing bacteria, capable of leaching radium, were isolated in low numbers from tailings samples but were isolated in significantly high numbers from topsoil in contact with the tailings. The results are placed in the context of the magnitude of uranium mill tailings in the United States, the hazards posed by the tailings, and how such hazards could be enhanced or diminished by microbial activities. Patterns in the composition of the microbial population are evaluated with respect to the ecological variables that influence microbial growth. ?? 1987 Springer-Verlag New York Inc.

  9. Feasible conversion of solid waste bauxite tailings into highly crystalline 4A zeolite with valuable application

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Ma, Dongyang; Wang, Zhendong; Guo, Min

    2014-11-15

    Highlights: • Concept to convert waste to valuable product is carried out in this study. • An industrially feasible and cost-effective approach was developed and optimized. • Highly crystalline and well-defined zeolite was produced under moderate conditions. • The zeolite derived from the bauxite tailings displayed high ion exchange capacity. • Bauxite tailings have potential application in heavy metal ions adsorbent. - Abstract: Bauxite tailings are a major type of solid wastes generated in the flotation process. The waste by-products caused significant environmental impact. To lessen this hazardous effect from poisonous mine tailings, a feasible and cost-effective solution was conceivedmore » and implemented. Our approach focused on reutilization of the bauxite tailings by converting it to 4A zeolite for reuse in diverse applications. Three steps were involved in the bauxite conversion: wet-chemistry, alkali fusion, and crystallization to remove impurities and to prepare porous 4A zeolite. It was found that the cubic 4A zeolite was single phase, in high purity, with high crystallinity and well-defined structure. Importantly, the 4A zeolite displayed maximum calcium ion exchange capacity averaged at 296 mg CaCO{sub 3}/g, comparable to commercially-available zeolite (310 mg CaCO{sub 3}/g) exchange capacity. Base on the optimal synthesis condition, the reaction yield of zeolite 4A from bauxite tailings achieved to about 38.43%, hence, this study will provide a new paradigm for remediation of bauxite tailings, further mitigating the environmental and health care concerns, particularly in the mainland of PR China.« less

  10. Stochastic modeling of the migration of Cs-137 in the soil considering a power law tailing in space

    NASA Astrophysics Data System (ADS)

    Oka, Hiroki; Hatano, Yuko

    2016-04-01

    We develop a theoretical model to reproduce the measured data of Cs-137 in the soil due to the Fukushima Daiichi NPP accident. In our past study, we derived the analytic solution under the generalized Robin boundary condition (Oka-Yamamoto solution). This is a generalization of the He-Walling solution (1996). We compared our solution with the Fukushima soil data of for 3 years after the accident and found that the concentration of Cs-137 has a discrepancy from our solution, specifically in a deep part because the depth profiles have a power law tailing. Therefore, we improved our model in the following aspect. When Cs particle (or Cs solution) migrate in the soil, the diffusion coefficient should be the results of many processes in the soil. These processes include the effect of various materials which constitute the soil (clay, litter, sand), or the variations of pore size in the soil. Hence we regard the diffusion coefficient as the stochastic variable, we derive the model. Specifically, we consider the solution of ADE to be the conditional probability C(x,t|D) in terms of the diffusion coefficient D and calculate C(x,t)=∫_(0~∞) C(x,t|D)*f(D)*dD, where f(D) is the probability density function of D. This model has a power law tailing in space like the space-fractional ADE.

  11. The impact of cemented layers and hardpans on oxygen diffusivity in mining waste heaps: a field study of the Halsbrücke lead-zinc mine tailings (Germany).

    PubMed

    Kohfahl, Claus; Graupner, Torsten; Fetzer, Christian; Pekdeger, Asaf

    2010-11-01

    This article reports fibre-optic oxygen measurements on a reactive mine waste heap located in the polymetallic sulphide mine district of Freiberg in south-eastern Germany. The heaped material consists of sulphide-bearing tailings from a processing plant of a lead-zinc mine. Mine waste material was deposited in the water phase after separation of mining ores in a flotation process. The tailing impoundment is partly covered with coarse sand and topsoil. Oxygen profiles were monitored during one year at eleven locations showing different physical and mineralogical compositions. At each location a borehole was drilled where the optic sensors were installed at 2-5 different depths. After installation the oxygen profiles were monitored seven times during one year from 2006-2007 and three to five oxygen profiles at each location were obtained. Oxygen measurements were accompanied by physical, chemical and mineralogical data of the tailing material. Additionally, a detailed mineralogical profile was analysed at a location representative for the central part of the heap, where the cemented layers show lateral continuity. Results showed that cemented layers have a significant influence on natural attenuation of the toxic As and Pb species owing to their capacity of water retention. The measured oxygen profiles are controlled by the zone of active pyrite weathering as well as by the higher water content in the cemented layers which reduces gaseous atmospheric oxygen supply. In contrast, gypsum bearing hardpans detected at three other locations have no detectable influence on oxygen profiles. Furthermore, the grain size distribution was proved to have a major effect on oxygen diffusivity due to its control on the water saturation. Temporal changes of the oxygen profiles were only observed at locations with coarse sediment material indicating also an important advective part of gas flux. Copyright © 2010 Elsevier B.V. All rights reserved.

  12. Calculation of the fast ion tail distribution for a spherically symmetric hot spot

    NASA Astrophysics Data System (ADS)

    McDevitt, C. J.; Tang, X.-Z.; Guo, Z.; Berk, H. L.

    2014-10-01

    The fast ion tail for a spherically symmetric hot spot is computed via the solution of a simplified Fokker-Planck collision operator. Emphasis is placed on describing the energy scaling of the fast ion distribution function in the hot spot as well as the surrounding cold plasma throughout a broad range of collisionalities and temperatures. It is found that while the fast ion tail inside the hot spot is significantly depleted, leading to a reduction of the fusion yield in this region, a surplus of fast ions is observed in the neighboring cold plasma region. The presence of this surplus of fast ions in the neighboring cold region is shown to result in a partial recovery of the fusion yield lost in the hot spot.

  13. 40 CFR 440.131 - General provisions.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... met. In no case shall a pH limitation below 5.0 be permitted. (e) Groundwater infiltration provision... infiltration contributes a substantial amount of water to the tailing impoundment or wastewater holding... groundwater infiltration. This discharge shall be subject to the limitations for mine drainage applicable to...

  14. 40 CFR 440.131 - General provisions.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... met. In no case shall a pH limitation below 5.0 be permitted. (e) Groundwater infiltration provision... infiltration contributes a substantial amount of water to the tailing impoundment or wastewater holding... groundwater infiltration. This discharge shall be subject to the limitations for mine drainage applicable to...

  15. Arsenic in the rhizosphere soil solution of ferns.

    PubMed

    Wei, Chaoyang; Zheng, Huan; Yu, Jiangping

    2012-12-01

    The aim of this study was to explore the evidence of arsenic hyperaccumulation in plant rhizosphere solutions. Six common fern plants were selected and grown in three types of substrate: arsenic (As) -tailings, As-spiked soil, and soil-As-tailing composites. A rhizobox was designed with an in-situ collection of soil solutions to analyze changes in the As concentration and valence as well as the pH, dissolved organic carbon (DOC) and total nitrogen (TN). Arsenite composed less than 20% of the total As, and As depletion was consistent with N depletion in the rhizosphere solutions of the various treatments. The As concentrations in the rhizosphere and non-rhizosphere solutions in the presence of plants were lower than in the respective controls without plants, except for in the As-spiked soils. The DOC concentrations were invariably higher in the rhizosphere versus non-rhizosphere solutions from the various plants; however, no significant increase in the DOC content was observed in Pteris vittata, in which only a slight decrease in pH appeared in the rhizosphere compared to non-rhizosphere solutions. The results showed that As reduction by plant roots was limited, acidification-induced solubilization was not the mechanism for As hyperaccumulation.

  16. Hydrologic Change during the Colonial Era of the United States: Beavers and the Energy Cost of Impoundments (Invited)

    NASA Astrophysics Data System (ADS)

    Green, M. B.; Bain, D. J.; Arrigo, J. S.; Duncan, J. M.; Kumar, S.; Parolari, A.; Salant, N.; Vorosmarty, C. J.; Aloysius, N. R.; Bray, E. N.; Ruffing, C. M.; Witherell, B. B.

    2009-12-01

    Europeans colonized North America in the early 17th century with intentions ranging between long-term inhabitation and quick extraction of resources for economic gain in Europe. Whatever the intentions, the colonists relied on the landscape for resources resulting in dramatic change to the forest and fur-bearing mammal population. We demonstrate that initial exploitation of North American forest and furs caused a substantial decrease in mean water residence time (τ) between 1600 and 1800 A.D. That loss, which regionally changed from 51 to 41 days, contrasts with conventional wisdom that humans tend to diminish variability in water resources by increasing storage capacity and thus increasing τ. The loss of τ resulted from over-hunted beaver for the hat market in Europe. Analysis suggests that colonial era demographics and economics did not allow human resource allocation to impoundment construction on a level matching the historic beaver effort. However, the τ appears to have regionally increased during the 19th century, suggesting that humans eventually began replacing the water storage lost with the beaver. The analysis highlights the energy cost of impounding water, which is likely to continue to be an important factor given the increasing need for stable water resources and finite energy resources.

  17. EAR AND TAIL LESIONS ON CAPTIVE WHITE-TAILED DEER FAWNS (ODOCOILEUS VIRGINIANUS): A CASE STUDY.

    PubMed

    Ferguson, Treena L; Demarais, Stephen; Cooley, Jim; Fleming, Sherrill; Michel, Eric S; Flinn, Emily

    2016-06-01

    During the 2008-2011 time period, undiagnosed lesions were observed in 21 of 150 white-tailed deer fawns (Odocoileus virginianus) that were part of a captive deer herd at Mississippi State University. Clinical findings in healthy and diseased fawns from 0 to 90 days of age included bite and scratch marks followed by moderate to severe ear and tail necrosis. Gross necropsy findings of necrotizing ulcerative dermatitis correlated with histopathologic findings that included focally severe multifocal vasculitis, vascular necrosis, and thrombosis. This article is a clinical description of these previously unreported lesions associated with tissue necrosis in young captive white-tailed deer.

  18. On the average configuration of the geomagnetic tail

    NASA Technical Reports Server (NTRS)

    Fairfield, D. H.

    1978-01-01

    Over 3000 hours of IMP-6 magnetic field data obtained between 20 and 33 R sub E in the geomagnetic tail have been used in a statistical study of the tail configuration. A distribution of 2.5 minute averages of B sub Z as a function of position across the tail reveals that more flux crosses the equatorial plane near the dawn and dusk flanks than near midnight. The tail field projected in the solar magnetospheric equatorial plane deviates from the X axis due to flaring and solar wind aberration by an angle alpha = -0.9 y sub SM - 1.7 where Y sub SM is in earth radii and alpha is in degrees. After removing these effects the Y component of the tail field is found to depend on interplanetary sector structure. During an away sector the B sub Y component of the tail field is on average 0.5 gamma greater than that during a toward sector, a result that is true in both tail lobes and is independent of location across the tail.

  19. Hydrologic considerations for estimation of storage-capacity requirements of impounding and side-channel reservoirs for water supply in Ohio

    USGS Publications Warehouse

    Koltun, G.F.

    2001-01-01

    This report provides data and methods to aid in the hydrologic design or evaluation of impounding reservoirs and side-channel reservoirs used for water supply in Ohio. Data from 117 streamflow-gaging stations throughout Ohio were analyzed by means of nonsequential-mass-curve-analysis techniques to develop relations between storage requirements, water demand, duration, and frequency. Information also is provided on minimum runoff for selected durations and frequencies. Systematic record lengths for the streamflow-gaging stations ranged from about 10 to 75 years; however, in many cases, additional streamflow record was synthesized. For impounding reservoirs, families of curves are provided to facilitate the estimation of storage requirements as a function of demand and the ratio of the 7-day, 2-year low flow to the mean annual flow. Information is provided with which to evaluate separately the effects of evaporation on storage requirements. Comparisons of storage requirements for impounding reservoirs determined by nonsequential-mass-curve-analysis techniques with storage requirements determined by annual-mass-curve techniques that employ probability routing to account for carryover-storage requirements indicate that large differences in computed required storages can result from the two methods, particularly for conditions where demand cannot be met from within-year storage. For side-channel reservoirs, tables of demand-storage-frequency information are provided for a primary pump relation consisting of one variable-speed pump with a pumping capacity that ranges from 0.1 to 20 times demand. Tables of adjustment ratios are provided to facilitate determination of storage requirements for 19 other pump sets consisting of assorted combinations of fixed-speed pumps or variable-speed pumps with aggregate pumping capacities smaller than or equal to the primary pump relation. The effects of evaporation on side-channel reservoir storage requirements are incorporated into the

  20. Power-law tails and non-Markovian dynamics in open quantum systems: An exact solution from Keldysh field theory

    NASA Astrophysics Data System (ADS)

    Chakraborty, Ahana; Sensarma, Rajdeep

    2018-03-01

    The Born-Markov approximation is widely used to study the dynamics of open quantum systems coupled to external baths. Using Keldysh formalism, we show that the dynamics of a system of bosons (fermions) linearly coupled to a noninteracting bosonic (fermionic) bath falls outside this paradigm if the bath spectral function has nonanalyticities as a function of frequency. In this case, we show that the dissipative and noise kernels governing the dynamics have distinct power-law tails. The Green's functions show a short-time "quasi"-Markovian exponential decay before crossing over to a power-law tail governed by the nonanalyticity of the spectral function. We study a system of bosons (fermions) hopping on a one-dimensional lattice, where each site is coupled linearly to an independent bath of noninteracting bosons (fermions). We obtain exact expressions for the Green's functions of this system, which show power-law decay ˜|t - t'|-3 /2 . We use these to calculate the density and current profile, as well as unequal-time current-current correlators. While the density and current profiles show interesting quantitative deviations from Markovian results, the current-current correlators show qualitatively distinct long-time power-law tails |t - t'|-3 characteristic of non-Markovian dynamics. We show that the power-law decays survive in the presence of interparticle interaction in the system, but the crossover time scale is shifted to larger values with increasing interaction strength.

  1. Tail Shape Design of Boat Wind Turbines

    NASA Astrophysics Data System (ADS)

    Singamsitty, Venkatesh

    Wind energy is a standout among the most generally utilized sustainable power source assets. A great deal of research and improvements have been happening in the wind energy field. Wind turbines are mechanical devices that convert kinetic energy into electrical power. Boat wind turbines are for the small-scale generation of electric power. In order to catch wind energy effectively, boat wind turbines need to face wind direction. Tails are used in boat wind turbines to alter the wind turbine direction and receive the variation of the incoming direction of wind. Tails are used to change the performance of boat wind turbines in an effective way. They are required to generate a quick and steady response as per change in wind direction. Tails can have various shapes, and their effects on boat wind turbines are different. However, the effects of tail shapes on the performance of boat wind turbines are not thoroughly studied yet. In this thesis, five tail shapes were studied. Their effects on boat wind turbines were investigated. The power extracted by the turbines from the air and the force acting on the boat wind turbine tail were analyzed. The results of this thesis provide a guideline of tail shape design for boat wind turbines.

  2. A differential game solution to the Coplanar tail-chase aerial combat problem

    NASA Technical Reports Server (NTRS)

    Merz, A. W.; Hague, D. S.

    1976-01-01

    Numerical results obtained in a simplified version of the one on one aerial combat problem are presented. The primary aim of the data is to specify the roles of pursuer and evader as functions of the relative geometry and of the significant physical parameters of the problem. Numerical results are given in a case in which the slower aircraft is more maneuverable than the faster aircraft. A third order dynamic model of the relative motion is described, for which the state variables are relative range, bearing, and heading. The ranges at termination are arbitary in the present version of the problem, so the weapon systems of both aircraft can be visualized as forward firing high velocity weapons, which must be aimed at the tail pipe of the evader. It was found that, for the great majority of the ralative geometries, each aircraft can evade the weapon system of the other.

  3. Quasi-steady state aerodynamics of the cheetah tail

    PubMed Central

    Boje, Edward; Fisher, Callen; Louis, Leeann; Lane, Emily

    2016-01-01

    ABSTRACT During high-speed pursuit of prey, the cheetah (Acinonyx jubatus) has been observed to swing its tail while manoeuvring (e.g. turning or braking) but the effect of these complex motions is not well understood. This study demonstrates the potential of the cheetah's long, furry tail to impart torques and forces on the body as a result of aerodynamic effects, in addition to the well-known inertial effects. The first-order aerodynamic forces on the tail are quantified through wind tunnel testing and it is observed that the fur nearly doubles the effective frontal area of the tail without much mass penalty. Simple dynamic models provide insight into manoeuvrability via simulation of pitch, roll and yaw tail motion primitives. The inertial and quasi-steady state aerodynamic effects of tail actuation are quantified and compared by calculating the angular impulse imparted onto the cheetah's body and its shown aerodynamic effects contribute to the tail's angular impulse, especially at the highest forward velocities. PMID:27412267

  4. Wing-Fuselage Interference, Tail Buffeting, and Air Flow About the Tail of a Low-Wing Monoplane

    NASA Technical Reports Server (NTRS)

    White, James A; Hood, Manley J

    1935-01-01

    This report presents the results of wind tunnel tests on a Mcdonnell Douglas airplane to determine the wing-fuselage interference of a low-wing monoplane. The tests included a study of tail buffeting and the air flow in the region of the tail. The airplane was tested with and without the propeller slipstream, both in the original condition and with several devices designed to reduce or eliminate tail buffeting. The devices used were wing-fuselage fillets, a NACA cowling, reflexed trailing edge of the wing, and stub auxiliary airfoils.

  5. Risk-Based Remediation Approach for Cs-137 Contaminated Sediment/Soils at the Savannah River Site (SRS) Lower Three Runs Tail (U) - 13348 - SRNS-RP-2012-00546

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Freeman, Candice; Bergren, Christopher; Blas, Susan

    Lower Three Runs is a large blackwater stream that runs through the eastern and southern portion of the Savannah River Site. The Lower Three Runs watershed includes two SRS facility areas: P Area (P Reactor) and R Area (R Reactor) that provided effluent discharges to Lower Three Runs. During reactor operations, effluent discharges were well above natural (pre-industrial) or present day stream discharges. The watershed contains a 2,500-acre mainstream impoundment (PAR Pond), several smaller pre-cooler ponds, and a canal system that connects the pre-cooler ponds and discharges surface water to PAR Pond. From the PAR Pond dam, Lower Three Runsmore » flows approximately 36 kilometers braiding through bottom-land/flood-plain forests before it enters the Savannah River. About eight kilometers downstream from the PAR Pond dam, the SRS boundary narrows (termed the Lower Three Runs tail) providing a limited buffer of DOE property for the Lower Three Runs stream and associated flood-plain. Previous screening characterization efforts revealed Cs-137 contamination in the sediment/soils of the flood-plain. As a part of the American Recovery and Reinvestment Act stimulus package, a comprehensive characterization effort was executed on the sediment/soils of the Lower Three Runs tail flood-plain providing a comprehensive look at the contaminant signature of the area. As a follow-up to that characterization, a regulatory decision Core Team, comprised of members of the South Carolina Department of Health and Environmental Control, Environmental Protection Agency - Region IV, and DOE, conducted negotiations on a risk-based approach to address the level of contamination found in the tail flood-plain as an early action that provided a long-term solution to exposure scenarios. For evaluation purposes, the adolescent trespasser was selected as the most likely human receptor for the Lower Three Runs tail portion because of the natural attractiveness of the area for recreational

  6. Four tails problems for dynamical collapse theories

    NASA Astrophysics Data System (ADS)

    McQueen, Kelvin J.

    2015-02-01

    The primary quantum mechanical equation of motion entails that measurements typically do not have determinate outcomes, but result in superpositions of all possible outcomes. Dynamical collapse theories (e.g. GRW) supplement this equation with a stochastic Gaussian collapse function, intended to collapse the superposition of outcomes into one outcome. But the Gaussian collapses are imperfect in a way that leaves the superpositions intact. This is the tails problem. There are several ways of making this problem more precise. But many authors dismiss the problem without considering the more severe formulations. Here I distinguish four distinct tails problems. The first (bare tails problem) and second (structured tails problem) exist in the literature. I argue that while the first is a pseudo-problem, the second has not been adequately addressed. The third (multiverse tails problem) reformulates the second to account for recently discovered dynamical consequences of collapse. Finally the fourth (tails problem dilemma) shows that solving the third by replacing the Gaussian with a non-Gaussian collapse function introduces new conflict with relativity theory.

  7. Some Effects of Horizontal-Tail Position on the Vertical-Tail Pressure Distributions of a Complete Model in Sideslip at High Subsonic Speeds

    NASA Technical Reports Server (NTRS)

    Alford, William J., Jr.

    1958-01-01

    An investigation has been made in the Langley high-speed 7- by 10-foot tunnel of some effects of horizontal-tail position on the vertical-tail pressure distributions of a complete model in sideslip at high subsonic speeds. The wing of the model was swept back 28.82 deg at the quarter-chord line and had an aspect ratio of 3.50, a taper ratio of 0.067, and NACA 65A004 airfoil sections parallel to the model plane of symmetry. Tests were made with the horizontal tail off, on the wing-chord plane extended, and in T-tail arrangements in forward and rearward locations. The test Mach numbers ranged from 0.60 to 0.92, which corresponds to a Reynolds number range from approximately 2.93 x 10(exp 6) to 3.69 x 10(exp 6), based on the wing mean aerodynamic chord. The sideslip angles varied from -3.9 deg to 12.7 deg at several selected angles of attack. The results indicated that, for a given angle of sideslip, increases in angle of attack caused reductions in the vertical-tail loads in the vicinity of the root chord and increases at the midspan and tip locations, with rearward movements in the local chordwise centers of pressure for the midspan locations and forward movements near the tip of the vertical tail. At the higher angles of attack all configurations investigated experienced outboard and rearward shifts in the center of pressure of the total vertical-tail load. Location of the horizontal tail on the wing- chord plane extended produced only small effects on the vertical-tail loads and centers of pressure. Locating the horizontal tail at the tip of the vertical tail in the forward position caused increases in the vertical-tail loads; this configuration, however, experienced considerable reduction in loads with increasing Mach number. Location of the horizontal tail at the tip of the vertical tail in the rearward position produced the largest increases in vertical-tail loads per degree sideslip angle; this configuration experienced the smallest variations of loads with

  8. Effect of rare earth Ce on the far infrared radiation property of iron ore tailings ceramics

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Liu, Jie; Institute of Power Source and Ecomaterials Science, Hebei University of Technology, Tianjin 300130; Meng, Junping, E-mail: srlj158@sina.com

    2015-06-15

    Highlights: • Detailed process proposed for preparation of iron ore tailings ceramics. • Replace natural minerals with iron ore tailings as raw materials for preparing functional ceramics. • Impact mechanism of Ce on far infrared ceramics, as well as its optimum addition amounts can be obtained. • Propose a new perspective on considering the mechanism of far infrared radiation. - Abstract: A kind of far infrared radiation ceramics was prepared by using iron ore tailings, CaCO{sub 3} and SiO{sub 2} as main raw materials, and Ce as additive. The result of Fourier transform infrared spectroscopy showed that the sample exhibitsmore » excellent radiation value of 0.914 when doping 7 wt.% Ce. Ce{sup 4+} dissolved into iron diopside and formed interstitial solid solution with it sintered at 1150 °C. The oxidation of Fe{sup 2+} to Fe{sup 3+} caused by Ce{sup 4+} led to a decrease of crystallite sizes and enhancement of Mg–O and Fe–O vibration in iron diopside, which consequently improved the far infrared radiation properties of iron ore tailings ceramics.« less

  9. The Distant Sodium Tail of Mercury

    NASA Technical Reports Server (NTRS)

    Potter, A. E.; Killen, R. M.; Morgan, T. H.

    2001-01-01

    Models of the sodium atmosphere of Mercury predict the possible existence of a cornet-like sodium tail. Detection and mapping of the predicted sodium tail would provide quantitative data on the energy of the process that produces sodium atoms from the planetary surface. Previous efforts to detect the sodium tail by means of observations done during daylight hours have been only partially successful because scattered sunlight obscured the weak sodium emissions in the tail. However, at greatest eastern elongation around the March equinox in the northern hemisphere, Mercury can be seen as an evening star in astronomical twilight. At this time, the intensity of scattered sunlight is low enough that sodium emissions as low as 500 Rayleighs can be detected. Additional information is contained in the original extended abstract.

  10. Surficial Geology of the Floor of Lake Mead (Arizona and Nevada) as Defined by Sidescan-Sonar Imagery, Lake-Floor Topography, and Post-Impoundment Sediment Thickness

    USGS Publications Warehouse

    Twichell, D.C.; Cross, V.A.

    2009-01-01

    Sidescan-sonar imagery collected in Lake Mead during 1999-2001, a period of high lake level, has been used to map the surficial geology of the floor of this large reservoir that formed upon completion of the Hoover Dam in 1935. Four surficial geologic units were identified and mapped: rock exposures and alluvial deposits that existed prior to the formation of the lake and thin post-impoundment sediments ( 1 m) deposited since the lake formed. Exposures of rock are most extensive in the narrow, steep-sided sections of the lake, while alluvial deposits are most extensive on the gentle flanks of the broader basin sections of the lake. Post-impoundment sediment is restricted to the floors of the original river valleys that now lie below lake level. These sediments are thickest in the deltas that form at the mouths of the Colorado River and its tributaries, but cover the entire length of the valley floors of the lake. This sediment distribution is consistent with deposition from turbidity currents. Lake level has dropped more than 30 m between collection of the sidescan imagery and publication of this report. During this time, thick delta deposits have been eroded and redistributed to deeper parts of the lake by turbidity currents. While present-day post-impoundment sediment distribution should be similar to what it was in 2001, the thickness may be greater in some of the deeper parts of the lake now.

  11. Detection of Mercury's Potassium Tail

    NASA Astrophysics Data System (ADS)

    Schmidt, Carl; Leblanc, Francois; Moore, Luke; Bida, Thomas A.

    2017-10-01

    Ground-based observations of Mercury's exosphere bridge the gap between the MESSENGER and BepiColombo missions and provide a broad counterpart to their in situ measurements. Here we report the first detection of Mercury's potassium tail in both emission lines of the D doublet. The sodium to potassium abundance ratio at 5 planetary radii down-tail is approximately 95, near the mid-point of a wide range of values that have been quoted over the planet's disk. This is several times the Na/K present in atmospheres of the Galilean satellites and more than an order of magnitude above Mercury's usual analogue, the Moon. The observations confirm that Mercury's anomalously high Na/K ratios cannot be explained by differences in neutral loss rates. The width and structure of the Na and K tails is comparable and both exhibit a persistent enhancement in their northern lobe. We interpret this as a signature of Mercury's offset magnetosphere; the exosphere's source rates are locally enhanced at the southern surface, and sloshing from radiation pressure and gravity guides this population into the northern region of the tail.

  12. Lifting-surface-theory aspect-ratio corrections to the lift and hinge-moment parameters for full-span elevators on horizontal tail surfaces

    NASA Technical Reports Server (NTRS)

    Swanson, Robert S; Crandall, Stewart M

    1948-01-01

    A limited number of lifting-surface-theory solutions for wings with chordwise loadings resulting from angle of attack, parabolic-ac camber, and flap deflection are now available. These solutions were studied with the purpose of determining methods of extrapolating the results in such a way that they could be used to determine lifting-surface-theory values of the aspect-ratio corrections to the lift and hinge-moment parameters for both angle-of-attack and flap-deflection-type loading that could be used to predict the characteristics of horizontal tail surfaces from section data with sufficient accuracy for engineering purposes. Such a method was devised for horizontal tail surfaces with full-span elevators. In spite of the fact that the theory involved is rather complex, the method is simple to apply and may be applied without any knowledge of lifting-surface theory. A comparison of experimental finite-span and section value and of the estimated values of the lift and hinge-moment parameters for three horizontal tail surfaces was made to provide an experimental verification of the method suggested. (author)

  13. Contributions of the S100A9 C-Terminal Tail to High-Affinity Mn(II) Chelation by the Host-Defense Protein Human Calprotectin

    PubMed Central

    Brophy, Megan Brunjes; Nakashige, Toshiki G.; Gaillard, Aleth; Nolan, Elizabeth M.

    2014-01-01

    Human calprotectin (CP) is an antimicrobial protein that coordinates Mn(II) with high affinity in a Ca(II)-dependent manner at an unusual histidine-rich site (site 2) formed at the S100A8/S100A9 dimer interface. We present a 16-member CP mutant family where mutations in the S100A9 C-terminal tail (residues 96–114) are employed to evaluate the contributions of this region, which houses three histidines and four acidic residues, to Mn(II) coordination at site 2. The results from analytical size-exclusion chromatography, Mn(II) competition titrations, and electron paramagnetic resonance spectroscopy establish that the C-terminal tail is essential for high-affinity Mn(II) coordination by native CP in solution. The studies indicate that His103 and His105 (HXH motif) of the tail complete the Mn(II) coordination sphere in solution, affording an unprecedented biological His6 site. These solution studies are in agreement with a Mn(II)-CP crystal structure reported recently (PNAS 2013, 110, 3841). Remarkably high-affinity Mn(II) binding is retained when either H103 or H105 are mutated to Ala, when the HXH motif is shifted from positions 103–105 to 104–106, and when the human tail is substituted by the C-terminal tail of murine S100A9. Nevertheless, antibacterial activity assays employing human CP mutants reveal that the native disposition of His residues is important for conferring growth inhibition against Escherichia coli and Staphylococcus aureus. Within the S100 family, the S100A8/S100A9 heterooligomer is essential for providing high-affinity Mn(II) binding; the S100A7ox, S100A9(C3S), S100A12, and S100B homodimers do not exhibit such Mn(II)-binding capacity. PMID:24245608

  14. Black-tailed and white-tailed jackrabbits in the American West: History, ecology, ecological significance, and survey methods

    USGS Publications Warehouse

    Simes, Matthew; Longshore, Kathleen M.; Nussear, Kenneth E.; Beatty, Greg L.; Brown, David E.; Esque, Todd C.

    2015-01-01

    Across the western United States, Leporidae are the most important prey item in the diet of Golden Eagles (Aquila chrysaetos). Leporids inhabiting the western United States include black-tailed (Lepus californicus) and white-tailed jackrabbits (Lepus townsendii) and various species of cottontail rabbit (Sylvilagus spp.). Jackrabbits (Lepus spp.) are particularly important components of the ecological and economic landscape of western North America because their abundance influences the reproductive success and population trends of predators such as coyotes (Canis latrans), bobcats (Lynx rufus), and a number of raptor species. Here, we review literature pertaining to black-tailed and white-tailed jackrabbits comprising over 170 published journal articles, notes, technical reports, conference proceedings, academic theses and dissertations, and other sources dating from the late 19th century to the present. Our goal is to present information to assist those in research and management, particularly with regard to protected raptor species (e.g., Golden Eagles), mammalian predators, and ecological monitoring. We classified literature sources as (1) general information on jackrabbit species, (2) black-tailed or (3) white-tailed jackrabbit ecology and natural history, or (4) survey methods. These categories, especially 2, 3, and 4, were further subdivided as appropriate. The review also produced several tables on population trends, food habits, densities within various habitats, and jackrabbit growth and development. Black-tailed and white-tailed jackrabbits are ecologically similar in general behaviors, use of forms, parasites, and food habits, and they are prey to similar predators; but they differ in their preferred habitats. While the black-tailed jackrabbit inhabits agricultural land, deserts, and shrublands, the white-tailed jackrabbit is associated with prairies, alpine tundra, and sagebrush-steppe. Frequently considered abundant, jackrabbit numbers in western North

  15. Heavy Tail Behavior of Rainfall Extremes across Germany

    NASA Astrophysics Data System (ADS)

    Castellarin, A.; Kreibich, H.; Vorogushyn, S.; Merz, B.

    2017-12-01

    Distributions are termed heavy-tailed if extreme values are more likely than would be predicted by probability distributions that have exponential asymptotic behavior. Heavy-tail behavior often leads to surprise, because historical observations can be a poor guide for the future. Heavy-tail behavior seems to be widespread for hydro-meteorological extremes, such as extreme rainfall and flood events. To date there have been only vague hints to explain under which conditions these extremes show heavy-tail behavior. We use an observational data set consisting of 11 climate variables at 1440 stations across Germany. This homogenized, gap-free data set covers 110 years (1901-2010) at daily resolution. We estimate the upper tail behavior, including its uncertainty interval, of daily precipitation extremes for the 1,440 stations at the annual and seasonal time scales. Different tail indicators are tested, including the shape parameter of the Generalized Extreme Value distribution, the upper tail ratio and the obesity index. In a further step, we explore to which extent the tail behavior can be explained by geographical and climate factors. A large number of characteristics is derived, such as station elevation, degree of continentality, aridity, measures for quantifying the variability of humidity and wind velocity, or event-triggering large-scale atmospheric situation. The link between the upper tail behavior and these characteristics is investigated via data mining methods capable of detecting non-linear relationships in large data sets. This exceptionally rich observational data set, in terms of number of stations, length of time series and number of explaining variables, allows insights into the upper tail behavior which is rarely possible given the typical observational data sets available.

  16. The fish community of a small impoundment in upstate New York

    USGS Publications Warehouse

    McCoy, C. Mead; Madenjian, Charles P.; Adams, Jean V.; Harman, Willard N.

    2001-01-01

    Moe Pond is a dimictic impoundment with surface area of 15.6 ha, a mean depth of 1.8 m, and an unexploited fish community of only two species: brown bullhead (Ameiurus nebulosus) and golden shiner (Notemigonus crysoleucas). The age-1 and older brown bullhead population was estimated to be 4,057 individuals, based on the Schnabel capture-recapture method of population estimation. Density and biomass were respectively estimated at 260 individuals/ha and 13 kg/ha. Annual survival rate of age-2 through age-5 brown bullheads was estimated at 48%. The golden shiner length-frequency distribution was unimodal with modal length of 80 mm and maximum total length of 115 m. The golden shiner population estimate was 7,154 individuals, based on seven beach seine haul replicate samples; the density and biomass were 686 shiners/ha and 5 kg/ha, respectively. This study provides an information baseline that may be useful in understanding food web interactions and whole-pond nutrient flux.

  17. Quasi-steady state aerodynamics of the cheetah tail.

    PubMed

    Patel, Amir; Boje, Edward; Fisher, Callen; Louis, Leeann; Lane, Emily

    2016-08-15

    During high-speed pursuit of prey, the cheetah (Acinonyx jubatus) has been observed to swing its tail while manoeuvring (e.g. turning or braking) but the effect of these complex motions is not well understood. This study demonstrates the potential of the cheetah's long, furry tail to impart torques and forces on the body as a result of aerodynamic effects, in addition to the well-known inertial effects. The first-order aerodynamic forces on the tail are quantified through wind tunnel testing and it is observed that the fur nearly doubles the effective frontal area of the tail without much mass penalty. Simple dynamic models provide insight into manoeuvrability via simulation of pitch, roll and yaw tail motion primitives. The inertial and quasi-steady state aerodynamic effects of tail actuation are quantified and compared by calculating the angular impulse imparted onto the cheetah's body and its shown aerodynamic effects contribute to the tail's angular impulse, especially at the highest forward velocities. © 2016. Published by The Company of Biologists Ltd.

  18. The Sodium Tail of the Moon

    NASA Technical Reports Server (NTRS)

    Matta, M.; Smith, S.; Baumgardner, J.; Wilson, J.; Martinis, C.; Mendillo, M.

    2009-01-01

    During the few days centered about new Moon, the lunar surface is optically hidden from Earth-based observers. However, the Moon still offers an observable: an extended sodium tail. The lunar sodium tail is the escaping "hot" component of a coma-like exosphere of sodium generated by photon-stimulated desorption, solar wind sputtering and meteoroid impact. Neutral sodium atoms escaping lunar gravity experience solar radiation pressure that drives them into the anti-solar direction forming a comet-like tail. During new Moon time, the geometry of the Sun, Moon and Earth is such that the anti-sunward sodium flux is perturbed by the terrestrial gravitational field resulting in its focusing into a dense core that extends beyond the Earth. An all-sky camera situated at the El Leoncito Observatory (CASLEO) in Argentina has been successfully imaging this tail through a sodium filter at each lunation since April 2006. This paper reports on the results of the brightness of the lunar sodium tail spanning 31 lunations between April 2006 and September 2008. Brightness variability trends are compared with both sporadic and shower meteor activity, solar wind proton energy flux and solar near ultra violet (NUV) patterns for possible correlations. Results suggest minimal variability in the brightness of the observed lunar sodium tail, generally uncorrelated with any single source, yet consistent with a multi-year period of minimal solar activity and non-intense meteoric fluxes.

  19. Physical space and long-tail markets

    NASA Astrophysics Data System (ADS)

    Bentley, R. Alexander; Madsen, Mark E.; Ormerod, Paul

    2009-03-01

    The Internet is known to have had a powerful impact on on-line retailer strategies in markets characterised by long-tail distribution of sales [C. Anderson, Long Tail: Why the Future of Business is Selling Less of More, Hyperion, New York, 2006]. Such retailers can exploit the long tail of the market, since they are effectively without physical limit on the number of choices on offer. Here we examine two extensions of this phenomenon. First, we introduce turnover into the long-tail distribution of sales. Although over any given period such as a week or a month, the distribution is right-skewed and often power law distributed, over time there is considerable turnover in the rankings of sales of individual products. Second, we establish some initial results on the implications for shelf-space and physical retailers in such markets.

  20. Microcrustaceans (Branchiopoda and Copepoda) of Wetland Ponds and Impoundments on the Savannah River Site, Aiken, South Carolina

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Adrienne E. DeBiase; Barbara E. Taylor

    2005-09-21

    The United States Department of Energy's Savannah River Site (SRS) in Aiken, Allendale, and Barnwell Counties, South Carolina, contains an abundance of freshwater wetlands and impoundments. Four large impoundments, as well as several small, abandoned farm and mill ponds, and about 400 Carolina bays and other small, isolated depression wetland ponds are located within the 893 km2 area of the SRS. Crustaceans of the orders Branchiopoda and Copepoda are nearly ubiquitous in these water bodies. Although small in size, these organisms are often very abundant. They consequently play an important trophic role in freshwater food webs supporting fish, larval salamanders,more » larval insects, and numerous other animals, aquatic and terrestrial. This report provides an introduction to the free-living microcrustaceans of lentic water bodies on the SRS and a comprehensive list of species known to occur there. Occurrence patterns are summarized from three extensive survey studies, supplemented with other published and unpublished records. In lieu of a key, we provide a guide to taxonomic resources and notes on undescribed species. Taxa covered include the orders Cladocera, Anostraca, Laevicaudata, and Spinicaudata of the Subclass Branchiopoda and the Superorders Calanoida and Cyclopoida of Subclass Copepoda. Microcrustaceans of the Superorder Harpacticoida of the Subclass Copepoda and Subclass Ostracoda are also often present in lentic water bodies. They are excluded from this report because they have not received much study at the species level on the SRS.« less

  1. THERMAL TRANSITIONS IN NORMAL AND DEUTERATED RAT-TAIL TENDON, HUMAN SKIN, AND TUNA-FISH SKIN

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Rigby, B.J.

    1962-07-30

    The transition temperature and shrinkage temperature of collogens were determined in normal and deuterated rat-tail tendon, human skin, and tuna-fish skin. Increases were observed in the deuterated samples. Results, obtained with solid collagen, are compared with those obtained with collagen in solution. It is concluded that hydrogen bonds are involved in both reactions. (C.H.)

  2. Metal mobilization under alkaline conditions in ash-covered tailings.

    PubMed

    Lu, Jinmei; Alakangas, Lena; Wanhainen, Christina

    2014-06-15

    The aim of this study was to determine element mobilization and accumulation in mill tailings under alkaline conditions. The tailings were covered with 50 cm of fly ash, and above a sludge layer. The tailings were geochemically and mineralogically investigated. Sulfides, such as pyrrhotite, sphalerite and galena along with gangue minerals such as dolomite, calcite, micas, chlorite, epidote, Mn-pyroxene and rhodonite were identified in the unoxidized tailings. The dissolution of the fly ash layer resulted in a high pH (close to 12) in the underlying tailings. This, together with the presence of organic matter, increased the weathering of the tailings and mobilization of elements in the uppermost 47 cm of the tailings. All primary minerals were depleted, except quartz and feldspar which were covered by blurry secondary carbonates. Sulfide-associated elements such as Cd, Fe, Pb, S and Zn and silicate-associated elements such as Fe, Mg and Mn were released from the depletion zone and accumulated deeper down in the tailings where the pH decreased to circum-neutral. Sequential extraction suggests that Cd, Cu, Fe, Pb, S and Zn were retained deeper down in the tailings and were mainly associated with the sulfide phase. Calcium, Cr, K and Ni released from the ash layer were accumulated in the uppermost depletion zone of the tailings. Copyright © 2014 Elsevier Ltd. All rights reserved.

  3. Vertical Tail Buffeting Alleviation Using Piezoelectric Actuators-Some Results of the Actively Controlled Response of Buffet-Affected Tails (ACROBAT) Program

    NASA Technical Reports Server (NTRS)

    Moses, Robert W.

    1997-01-01

    Buffet is an aeroelastic phenomenon associated with high performance aircraft especially those with twin vertical tails. In particular, for the F/A-18 aircraft at high angles of attack, vortices emanating from wing/fuselage leading edge extensions burst, immersing the vertical tails in their wake. The resulting buffet loads on the vertical tails are a concern from fatigue and inspection points of view. Recently, a 1/6-scale F-18 wind-tunnel model was tested in the Transonic Dynamics Tunnel at the NASA Langley Research Center as part of the Actively Controlled Response Of Buffet Affected Tails (ACROBAT) Program to assess the use of active controls in reducing vertical tail buffeting. The starboard vertical tail was equipped with an active rudder and the port vertical tail was equipped with piezoelectric actuators. The tunnel conditions were atmospheric air at Mach 0.10. By using single-input-single-output control laws at gains well below the physical limits of the actuators, the power spectral density of the root strains at the frequency of the first bending mode of the vertical tail was reduced by as much as 60 percent up to angles of attack of 37 degrees. Root mean square (RMS) values of root strain were reduced by as much as 19 percent. The results herein illustrate that buffet alleviation of vertical tails can be accomplished using simple active control of the rudder or piezoelectric actuators. In fact, as demonstrated herein, a fixed gain single input single output control law that commands piezoelectric actuators may be active throughout the high angle-of-attack maneuver without requiring any changes during the maneuver. Future tests are mentioned for accentuating the international interest in this area of research.

  4. Ecological restoration alters microbial communities in mine tailings profiles

    NASA Astrophysics Data System (ADS)

    Li, Yang; Jia, Zhongjun; Sun, Qingye; Zhan, Jing; Yang, Yang; Wang, Dan

    2016-04-01

    Ecological restoration of mine tailings have impact on soil physiochemical properties and microbial communities. The surface soil has been a primary concern in the past decades, however it remains poorly understood about the adaptive response of microbial communities along the profile during ecological restoration of the tailings. In this study, microbial communities along a 60-cm profile were investigated in a mine tailing pond during ecological restoration of the bare waste tailings (BW) with two vegetated soils of Imperata cylindrica (IC) and Chrysopogon zizanioides (CZ) plants. Revegetation of both IC and CZ could retard soil degradation of mine tailing by stimulation of soil pH at 0-30 cm soils and altered the bacterial communities at 0-20 cm depths of the mine tailings. Significant differences existed in the relative abundance of the phyla Alphaproteobacteria, Deltaproteobacteria, Acidobacteria, Firmicutes and Nitrospira. Slight difference of bacterial communities were found at 30-60 cm depths of mine tailings. Abundance and activity analysis of nifH genes also explained the elevated soil nitrogen contents at the surface 0-20 cm of the vegetated soils. These results suggest that microbial succession occurred primarily at surface tailings and vegetation of pioneering plants might have promoted ecological restoration of mine tailings.

  5. Ecological restoration alters microbial communities in mine tailings profiles.

    PubMed

    Li, Yang; Jia, Zhongjun; Sun, Qingye; Zhan, Jing; Yang, Yang; Wang, Dan

    2016-04-29

    Ecological restoration of mine tailings have impact on soil physiochemical properties and microbial communities. The surface soil has been a primary concern in the past decades, however it remains poorly understood about the adaptive response of microbial communities along the profile during ecological restoration of the tailings. In this study, microbial communities along a 60-cm profile were investigated in a mine tailing pond during ecological restoration of the bare waste tailings (BW) with two vegetated soils of Imperata cylindrica (IC) and Chrysopogon zizanioides (CZ) plants. Revegetation of both IC and CZ could retard soil degradation of mine tailing by stimulation of soil pH at 0-30 cm soils and altered the bacterial communities at 0-20 cm depths of the mine tailings. Significant differences existed in the relative abundance of the phyla Alphaproteobacteria, Deltaproteobacteria, Acidobacteria, Firmicutes and Nitrospira. Slight difference of bacterial communities were found at 30-60 cm depths of mine tailings. Abundance and activity analysis of nifH genes also explained the elevated soil nitrogen contents at the surface 0-20 cm of the vegetated soils. These results suggest that microbial succession occurred primarily at surface tailings and vegetation of pioneering plants might have promoted ecological restoration of mine tailings.

  6. Ecological restoration alters microbial communities in mine tailings profiles

    PubMed Central

    Li, Yang; Jia, Zhongjun; Sun, Qingye; Zhan, Jing; Yang, Yang; Wang, Dan

    2016-01-01

    Ecological restoration of mine tailings have impact on soil physiochemical properties and microbial communities. The surface soil has been a primary concern in the past decades, however it remains poorly understood about the adaptive response of microbial communities along the profile during ecological restoration of the tailings. In this study, microbial communities along a 60-cm profile were investigated in a mine tailing pond during ecological restoration of the bare waste tailings (BW) with two vegetated soils of Imperata cylindrica (IC) and Chrysopogon zizanioides (CZ) plants. Revegetation of both IC and CZ could retard soil degradation of mine tailing by stimulation of soil pH at 0–30 cm soils and altered the bacterial communities at 0–20 cm depths of the mine tailings. Significant differences existed in the relative abundance of the phyla Alphaproteobacteria, Deltaproteobacteria, Acidobacteria, Firmicutes and Nitrospira. Slight difference of bacterial communities were found at 30–60 cm depths of mine tailings. Abundance and activity analysis of nifH genes also explained the elevated soil nitrogen contents at the surface 0–20 cm of the vegetated soils. These results suggest that microbial succession occurred primarily at surface tailings and vegetation of pioneering plants might have promoted ecological restoration of mine tailings. PMID:27126064

  7. Groundwater Impact Assessment of Tailings Storage Facility, Western Turkey

    NASA Astrophysics Data System (ADS)

    Peksezer-Sayit, A.; Yazicigil, H.

    2015-12-01

    A tailings storage facility (TSF) is a fundamental part of the mining process and should be carefully designed and managed to prevent any adverse environmental effects. TSF is site-specific and its design criteria are determined by regulations. The new mine waste regulation for the deposition of hazardous waste in a tailings storage facility in Turkey enforces, from bottom to top, 0.5 m thick compacted clay layer with K less than or equal to 1X10-9 m/s , 2 mm thick HDPE geomembrane, and a protective natural material or geotextile. Although these criteria seem to be enough to prevent leakage from the base, in practice, manufacturing and application errors may cause leakage and subsequent contamination of groundwater. The purpose of this study is to assess potential impacts of leakage from the base of TSF on groundwater quality both in operational and post-closure period of a mine site in western Turkey. For this purpose, analytical and 2-D and 3-D numerical models are used together. The potential leakage rate of sulphate-bearing solution from the base of TSF is determined from analytical model. 2-D finite element models (SEEP/W and CTRAN/W) are used to simulate unsaturated flow conditions and advective-dispersive contaminant transport below the TSF under steady-state and transient conditions for the operating period. The long-term impacts of leakage from the base of TSF on groundwater resources are evaluated by 3-D numerical groundwater flow (MODFLOW) and contaminant transport models (MT3DMS). The model results suggest that sulphate-bearing solution leaking from the base of TSF can reach water table in about 290 years. Hence, during the operational period (i.e. 21 years), no interaction is expected between the solution and groundwater. Moreover, long-term simulation results show that about 500 years later, the sulphate concentration in groundwater will be below the maximum allowable limits (i.e. 250 mg/L).

  8. A proactive approach to sustainable management of mine tailings

    NASA Astrophysics Data System (ADS)

    Edraki, Mansour; Baumgartl, Thomas

    2015-04-01

    The reactive strategies to manage mine tailings i.e. containment of slurries of tailings in tailings storage facilities (TSF's) and remediation of tailings solids or tailings seepage water after the decommissioning of those facilities, can be technically inefficient to eliminate environmental risks (e.g. prevent dispersion of contaminants and catastrophic dam wall failures), pose a long term economic burden for companies, governments and society after mine closure, and often fail to meet community expectations. Most preventive environmental management practices promote proactive integrated approaches to waste management whereby the source of environmental issues are identified to help make a more informed decisions. They often use life cycle assessment to find the "hot spots" of environmental burdens. This kind of approach is often based on generic data and has rarely been used for tailings. Besides, life cycle assessments are less useful for designing operations or simulating changes in the process and consequent environmental outcomes. It is evident that an integrated approach for tailings research linked to better processing options is needed. A literature review revealed that there are only few examples of integrated approaches. The aim of this project is to develop new tailings management models by streamlining orebody characterization, process optimization and rehabilitation. The approach is based on continuous fingerprinting of geochemical processes from orebody to tailings storage facility, and benchmark the success of such proactive initiatives by evidence of no impacts and no future projected impacts on receiving environments. We present an approach for developing such a framework and preliminary results from a case study where combined grinding and flotation models developed using geometallurgical data from the orebody were constructed to predict the properties of tailings produced under various processing scenarios. The modelling scenarios based on the

  9. 14 CFR 23.481 - Tail down landing conditions.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Tail down landing conditions. 23.481 Section 23.481 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION... Ground Loads § 23.481 Tail down landing conditions. (a) For a tail down landing, the airplane is assumed...

  10. 77 FR 74470 - Intent to Prepare an Environmental Impact Statement (EIS) for the Donlin Gold Project

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-14

    ... added to the project mailing list and for additional information, please visit the following web site... miles long by 1 mile wide by 1,850 feet deep; a waste treatment facility (tailings impoundment... description of the proposed project will be posted on the project web site prior to these meetings to help the...

  11. Moth tails divert bat attack: evolution of acoustic deflection.

    PubMed

    Barber, Jesse R; Leavell, Brian C; Keener, Adam L; Breinholt, Jesse W; Chadwell, Brad A; McClure, Christopher J W; Hill, Geena M; Kawahara, Akito Y

    2015-03-03

    Adaptations to divert the attacks of visually guided predators have evolved repeatedly in animals. Using high-speed infrared videography, we show that luna moths (Actias luna) generate an acoustic diversion with spinning hindwing tails to deflect echolocating bat attacks away from their body and toward these nonessential appendages. We pit luna moths against big brown bats (Eptesicus fuscus) and demonstrate a survival advantage of ∼ 47% for moths with tails versus those that had their tails removed. The benefit of hindwing tails is equivalent to the advantage conferred to moths by bat-detecting ears. Moth tails lured bat attacks to these wing regions during 55% of interactions between bats and intact luna moths. We analyzed flight kinematics of moths with and without hindwing tails and suggest that tails have a minimal role in flight performance. Using a robust phylogeny, we find that long spatulate tails have independently evolved four times in saturniid moths, further supporting the selective advantage of this anti-bat strategy. Diversionary tactics are perhaps more common than appreciated in predator-prey interactions. Our finding suggests that focusing on the sensory ecologies of key predators will reveal such countermeasures in prey.

  12. The effect of intact talin and talin tail fragment on actin filament dynamics and structure depends on pH and ionic strength.

    PubMed

    Goldmann, W H; Hess, D; Isenberg, G

    1999-03-01

    We employed quasi-elastic light scattering and electron microscopy to investigate the influence of intact talin and talin tail fragment on actin filament dynamics and network structure. Using these methods, we confirm previous reports that intact talin induces cross-linking as well as filament shortening on actin networks. We now show that the effect of intact talin as well as talin tail fragment on actin networks is controlled by pH and ionic strength. At pH 7.5, actin filament dynamics in the presence of intact talin and talin tail fragment are characterized by a rapid decay of the dynamic structure factor and by a square root power law for the stretched exponential decay which is in contrast with the theory for pure actin solutions. At pH 6 and low ionic strength, intact talin cross-links actin filaments more tightly than talin tail fragment. Talin head fragment showed no effect on actin networks, indicating that the actin binding sites reside probably exclusively within the tail domain.

  13. Flexible histone tails in a new mesoscopic oligonucleosome model.

    PubMed

    Arya, Gaurav; Zhang, Qing; Schlick, Tamar

    2006-07-01

    We describe a new mesoscopic model of oligonucleosomes that incorporates flexible histone tails. The nucleosome cores are modeled using the discrete surface-charge optimization model, which treats the nucleosome as an electrostatic surface represented by hundreds of point charges; the linker DNAs are treated using a discrete elastic chain model; and the histone tails are modeled using a bead/chain hydrodynamic approach as chains of connected beads where each bead represents five protein residues. Appropriate charges and force fields are assigned to each histone chain so as to reproduce the electrostatic potential, structure, and dynamics of the corresponding atomistic histone tails at different salt conditions. The dynamics of resulting oligonucleosomes at different sizes and varying salt concentrations are simulated by Brownian dynamics with complete hydrodynamic interactions. The analyses demonstrate that the new mesoscopic model reproduces experimental results better than its predecessors, which modeled histone tails as rigid entities. In particular, our model with flexible histone tails: correctly accounts for salt-dependent conformational changes in the histone tails; yields the experimentally obtained values of histone-tail mediated core/core attraction energies; and considers the partial shielding of electrostatic repulsion between DNA linkers as a result of the spatial distribution of histone tails. These effects are crucial for regulating chromatin structure but are absent or improperly treated in models with rigid histone tails. The development of this model of oligonucleosomes thus opens new avenues for studying the role of histone tails and their variants in mediating gene expression through modulation of chromatin structure.

  14. From dinosaurs to birds: a tail of evolution

    PubMed Central

    2014-01-01

    A particularly critical event in avian evolution was the transition from long- to short-tailed birds. Primitive bird tails underwent significant alteration, most notably reduction of the number of caudal vertebrae and fusion of the distal caudal vertebrae into an ossified pygostyle. These changes, among others, occurred over a very short evolutionary interval, which brings into focus the underlying mechanisms behind those changes. Despite the wealth of studies delving into avian evolution, virtually nothing is understood about the genetic and developmental events responsible for the emergence of short, fused tails. In this review, we summarize the current understanding of the signaling pathways and morphological events that contribute to tail extension and termination and examine how mutations affecting the genes that control these pathways might influence the evolution of the avian tail. To generate a list of candidate genes that may have been modulated in the transition to short-tailed birds, we analyzed a comprehensive set of mouse mutants. Interestingly, a prevalent pleiotropic effect of mutations that cause fused caudal vertebral bodies (as in the pygostyles of birds) is tail truncation. We identified 23 mutations in this class, and these were primarily restricted to genes involved in axial extension. At least half of the mutations that cause short, fused tails lie in the Notch/Wnt pathway of somite boundary formation or differentiation, leading to changes in somite number or size. Several of the mutations also cause additional bone fusions in the trunk skeleton, reminiscent of those observed in primitive and modern birds. All of our findings were correlated to the fossil record. An open question is whether the relatively sudden appearance of short-tailed birds in the fossil record could be accounted for, at least in part, by the pleiotropic effects generated by a relatively small number of mutational events. PMID:25621146

  15. Exploring Stellar Populations in the Tidal Tails of NGC3256

    NASA Astrophysics Data System (ADS)

    Rodruck, Michael; Konstantopoulos, Iraklis; Charlton, Jane C.

    2015-01-01

    Galaxy interactions can inject material into the intergalactic medium via violent gravitational dynamics, often visualized in tidal tails. The composition of these tails has remained a mystery, as previous studies have focused on detecting tidal features, rather than the composite material itself. With this in mind, we have developed an observing program using deep, multiband imaging to probe the chaotic regions of tidal tails in search for an underlying stellar population. NGC3256's Western and Eastern tidal tails serve as a case study for this new technique. Our results show median color values of u - g = 1.12 and r - i = 0.09 for the Western tail, and u - g = 1.29 and r - i = 0.21 for the Eastern tail, corresponding to ages of approximately 450 Myr and 900 Myr for the tails, respectively. A u - g color gradient is seen in the Western tail as well, running from 1.32 to 1.08 (~2000 Myr to 400 Myr), suggesting ages inside tidal tails can have significant variations.

  16. Role of organic acids in promoting colloidal transport of mercury from mine tailings

    USGS Publications Warehouse

    Slowey, A.J.; Johnson, S.B.; Rytuba, J.J.; Brown, Gordon E.

    2005-01-01

    A number of factors affect the transport of dissolved and paniculate mercury (Hg) from inoperative Hg mines, including the presence of organic acids in the rooting zone of vegetated mine waste. We examined the role of the two most common organic acids in soils (oxalic and citric acid) on Hg transport from such waste by pumping a mixed organic acid solution (pH 5.7) at 1 mL/min through Hg mine tailings columns. For the two total organic acid concentrations investigated (20 ??M and 1 mM), particle-associated Hg was mobilized, with the onset of paniculate Hg transport occurring later for the lower organic acid concentration. Chemical analyses of column effluent indicate that 98 wt % of Hg mobilized from the column was paniculate. Hg speciation was determined using extended X-ray absorption fine structure spectroscopy and transmission electron microscopy, showing that HgS minerals are dominant in the mobilized particles. Hg adsorbed to colloids is another likely mode of transport due to the abundance of Fe-(oxyhydr)oxides, Fe-sulfides, alunite, and jarosite in the tailings to which Hg(II) adsorbs. Organic acids produced by plants are likely to enhance the transport of colloid-associated Hg from vegetated Hg mine tailings by dissolving cements to enable colloid release. ?? 2005 American Chemical Society.

  17. Sirenomelia apus with vestigial tail.

    PubMed

    Parikh, Tushar B; Nanavati, Ruchi N; Udani, Rekha H

    2005-04-01

    Sirenomelia is an exceptionally rare congenital malformation characterized by complete or near complete fusion of lower limbs. A newborn with clinical features of sirenomelia including fused lower limbs in medial position, absent fibula, anal atresia, complete absence of urogenital system (bilateral renal agenesis, absent ureters, urinary bladder, absent internal and external genitalia), a single umbilical artery and a vestigial tail is reported. Association of vestigial tail with sirenomelia is not described in the literature.

  18. The effect of density-of-state tails on band-to-band tunneling: Theory and application to tunnel field effect transistors

    NASA Astrophysics Data System (ADS)

    Sant, S.; Schenk, A.

    2017-10-01

    It is demonstrated how band tail states in the semiconductor influence the performance of a Tunnel Field Effect Transistor (TFET). As a consequence of the smoothened density of states (DOS) around the band edges, the energetic overlap of conduction and valence band states occurs gradually at the onset of band-to-band tunneling (BTBT), thus degrading the sub-threshold swing (SS) of the TFET. The effect of the band tail states on the current-voltage characteristics is modelled quantum-mechanically based on the idea of zero-phonon trap-assisted tunneling between band and tail states. The latter are assumed to arise from a 3-dimensional pseudo-delta potential proposed by Vinogradov [1]. This model potential allows the derivation of analytical expressions for the generation rate covering the whole range from very strong to very weak localization of the tail states. Comparison with direct BTBT in the one-band effective mass approximation reveals the essential features of tail-to-band tunneling. Furthermore, an analytical solution for the problem of tunneling from continuum states of the disturbed DOS to states in the opposite band is found, and the differences to direct BTBT are worked out. Based on the analytical expressions, a semi-classical model is implemented in a commercial device simulator which involves numerical integration along the tunnel paths. The impact of the tail states on the device performance is analyzed for a nanowire Gate-All-Around TFET. The simulations show that tail states notably impact the transfer characteristics of a TFET. It is found that exponentially decaying band tails result in a stronger degradation of the SS than tail states with a Gaussian decay of their density. The developed model allows more realistic simulations of TFETs including their non-idealities.

  19. BIOMECHANICS. Why the seahorse tail is square.

    PubMed

    Porter, Michael M; Adriaens, Dominique; Hatton, Ross L; Meyers, Marc A; McKittrick, Joanna

    2015-07-03

    Whereas the predominant shapes of most animal tails are cylindrical, seahorse tails are square prisms. Seahorses use their tails as flexible grasping appendages, in spite of a rigid bony armor that fully encases their bodies. We explore the mechanics of two three-dimensional-printed models that mimic either the natural (square prism) or hypothetical (cylindrical) architecture of a seahorse tail to uncover whether or not the square geometry provides any functional advantages. Our results show that the square prism is more resilient when crushed and provides a mechanism for preserving articulatory organization upon extensive bending and twisting, as compared with its cylindrical counterpart. Thus, the square architecture is better than the circular one in the context of two integrated functions: grasping ability and crushing resistance. Copyright © 2015, American Association for the Advancement of Science.

  20. Peak and Tail Scaling of Breakthrough Curves in Hydrologic Tracer Tests

    NASA Astrophysics Data System (ADS)

    Aquino, T.; Aubeneau, A. F.; Bolster, D.

    2014-12-01

    Power law tails, a marked signature of anomalous transport, have been observed in solute breakthrough curves time and time again in a variety of hydrologic settings, including in streams. However, due to the low concentrations at which they occur they are notoriously difficult to measure with confidence. This leads us to ask if there are other associated signatures of anomalous transport that can be sought. We develop a general stochastic transport framework and derive an asymptotic relation between the tail scaling of a breakthrough curve for a conservative tracer at a fixed downstream position and the scaling of the peak concentration of breakthrough curves as a function of downstream position, demonstrating that they provide equivalent information. We then quantify the relevant spatiotemporal scales for the emergence of this asymptotic regime, where the relationship holds, in the context of a very simple model that represents transport in an idealized river. We validate our results using random walk simulations. The potential experimental benefits and limitations of these findings are discussed.

  1. The niche of an invasive marine microbe in a subtropical freshwater impoundment

    PubMed Central

    David Hambright, K; Beyer, Jessica E; Easton, James D; Zamor, Richard M; Easton, Anne C; Hallidayschult, Thayer C

    2015-01-01

    Growing attention in aquatic ecology is focusing on biogeographic patterns in microorganisms and whether these potential patterns can be explained within the framework of general ecology. The long-standing microbiologist's credo ‘Everything is everywhere, but, the environment selects' suggests that dispersal is not limiting for microbes, but that the environment is the primary determining factor in microbial community composition. Advances in molecular techniques have provided new evidence that biogeographic patterns exist in microbes and that dispersal limitation may actually have an important role, yet more recent study using extremely deep sequencing predicts that indeed everything is everywhere. Using a long-term field study of the ‘invasive' marine haptophyte Prymnesium parvum, we characterize the environmental niche of P. parvum in a subtropical impoundment in the southern United States. Our analysis contributes to a growing body of evidence that indicates a primary role for environmental conditions, but not dispersal, in the lake-wide abundances and seasonal bloom patterns in this globally important microbe. PMID:24950108

  2. Experiments on a Tail-wheel Shimmy

    NASA Technical Reports Server (NTRS)

    Harling, R; Dietz, O

    1954-01-01

    Model tests on the "running belt" and tests with a full-scale tail wheel were made on a rotating drum as well as on a runway in order to investigate the causes of the undesirable shimmy phenomena frequently occurring on airplane tail wheels, and the means of avoiding them. The small model (scale 1:10) permitted simulation of the mass, moments of inertia, and fuselage stiffness of the airplane and determination of their influence on the shimmy, whereas by means of the larger model with pneumatic tires (scale 1:2) more accurate investigations were made on the tail wheel itself. The results of drum and road tests show good agreement with one another and with model values. Detailed investigations were made regarding the dependence of the shimmy tendency on trail, rolling speed, load, size of tires, ground friction,and inclination of the swivel axis; furthermore, regarding the influence of devices with restoring effect on the tail wheel, and the friction damping required for prevention of shimmy. Finally observations from slow-motion pictures are reported and conclusions drawn concerning the influence of tire deformation.

  3. Tail loss and thermoregulation in the common lizard Zootoca vivipara

    NASA Astrophysics Data System (ADS)

    Herczeg, Gábor; Kovács, Tibor; Tóth, Tamás; Török, János; Korsós, Zoltán; Merilä, Juha

    2004-10-01

    Tail autotomy in lizards is an adaptive strategy that has evolved to reduce the risk of predation. Since tail loss reduces body mass and moving ability—which in turn are expected to influence thermal balance—there is potential for a trade-off between tail autotomy and thermoregulation. To test this hypothesis, we studied a common lizard (Zootoca vivipara) population at high latitude, inhabiting a high-cost thermal environment. Z. vivipara is a small, non-territorial lizard known as a very accurate thermoregulator. We made two predictions: (1) the reduced body weight due to tail loss results in faster heating rate (a benefit), and (2) the reduction in locomotor ability after tail loss induces a shift to the use of thermally poorer microhabitats (a cost), thus decreasing the field body temperatures of active lizards. We did not find any effect of tail loss on heating rate in laboratory experiments conducted under different thermal conditions. Likewise, no significant relationship between tail condition and field body temperatures, or between tail condition and thermal microhabitat use, were detected. Thus, our results suggest that tail autotomy does not influence the accuracy of thermoregulation in small-bodied lizards.

  4. Tail loss and thermoregulation in the common lizard Zootoca vivipara.

    PubMed

    Herczeg, Gábor; Kovács, Tibor; Tóth, Tamás; Török, János; Korsós, Zoltán; Merilä, Juha

    2004-10-01

    Tail autotomy in lizards is an adaptive strategy that has evolved to reduce the risk of predation. Since tail loss reduces body mass and moving ability-which in turn are expected to influence thermal balance-there is potential for a trade-off between tail autotomy and thermoregulation. To test this hypothesis, we studied a common lizard (Zootoca vivipara) population at high latitude, inhabiting a high-cost thermal environment. Z. vivipara is a small, non-territorial lizard known as a very accurate thermoregulator. We made two predictions: (1) the reduced body weight due to tail loss results in faster heating rate (a benefit), and (2) the reduction in locomotor ability after tail loss induces a shift to the use of thermally poorer microhabitats (a cost), thus decreasing the field body temperatures of active lizards. We did not find any effect of tail loss on heating rate in laboratory experiments conducted under different thermal conditions. Likewise, no significant relationship between tail condition and field body temperatures, or between tail condition and thermal microhabitat use, were detected. Thus, our results suggest that tail autotomy does not influence the accuracy of thermoregulation in small-bodied lizards.

  5. Alleviation of environmental risks associated with severely contaminated mine tailings using amendments: Modeling of trace element speciation, solubility, and plant accumulation.

    PubMed

    Pardo, Tania; Bes, Cleménce; Bernal, Maria Pilar; Clemente, Rafael

    2016-11-01

    Tailings are considered one of the most relevant sources of contamination associated with mining activities. Phytostabilization of mine spoils may need the application of the adequate combination of amendments to facilitate plant establishment and reduce their environmental impact. Two pot experiments were set up to assess the capability of 2 inorganic materials (calcium carbonate and a red mud derivate, ViroBind TM ), alone or in combination with organic amendments, for the stabilization of highly acidic trace element-contaminated mine tailings using Atriplex halimus. The effects of the treatments on tailings and porewater physico-chemical properties and trace-element accumulation by the plants, as well as the processes governing trace elements speciation and solubility in soil solution and their bioavailability were modeled. The application of the amendments increased tailings pH and decreased (>99%) trace elements solubility in porewater, but also changed the speciation of soluble Cd, Cu, and Pb. All the treatments made A. halimus growth in the tailings possible; organic amendments increased plant biomass and nutritional status, and reduced trace-element accumulation in the plants. Tailings amendments modified trace-element speciation in porewater (favoring the formation of chlorides and/or organo-metallic forms) and their solubility and plant uptake, which were found to be mainly governed by tailing/porewater pH, electrical conductivity, and organic carbon content, as well as soluble/available trace-element concentrations. Environ Toxicol Chem 2016;35:2874-2884. © 2016 SETAC. © 2016 SETAC.

  6. On the folding phenomenon of comet tail rays

    NASA Astrophysics Data System (ADS)

    Ershkovich, A. I.

    1982-01-01

    It is shown that the folding phenomenon of the comet tail rays is compatible with the Ferraro isorotation law if the comet tail magnetic field has no azimuthal component, that is, Bphi (the polar angle) equals zero. Considering electric drift due to convectional electric fields, a formula is obtained for the angular rate of a ray closure which reduces to that of Ness and Donn (1966) if the velocity profile across the tail is linear. The magnetic field B of approximately 20-40 gammas in the coma and less than about 10 gammas in the distant tail is estimated under typical solar wind conditions at 1 AU.

  7. A note on trans-Planckian tail effects

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Graef, L.L.; Brandenberger, R., E-mail: leilagraef@usp.br, E-mail: rhb@physics.mcgill.ca

    2015-09-01

    We study the proposal by Mersini et al. [1] that the observed dark energy might be explained by the back-reaction of the set of tail modes in a theory with a dispersion relation in which the mode frequency decays exponentially in the trans-Planckian regime. The matter tail modes are frozen out, however they induce metric fluctuations. The energy-momentum tensor with which the tail modes effect the background geometry obtains contributions from both metric and matter fluctuations. We calculate the equation of state induced by the tail modes taking into account the gravitational contribution. We find that, in contrast to themore » case of frozen super-Hubble cosmological fluctuations, in this case the matter perturbations dominate, and they yield an equation of state which to leading order takes the form of a positive cosmological constant.« less

  8. Adaptive Suction and Blowing for Twin-Tail Buffet Control

    NASA Technical Reports Server (NTRS)

    Kandil, Osama A.; Yang, Zhi

    1999-01-01

    Adaptive active flow control for twin-tail buffet alleviation is investigated. The concept behind this technique is to place control ports on the tail outer and inner surfaces with flow suction or blowing applied through these ports in order to minimize the pressure difference across the tail. The suction or blowing volume flow rate from each port is proportional to the pressure difference across the tail at this location. A parametric study of the effects of the number and location of these ports on the buffet response is carried out. The computational model consists of a sharp-edged delta wing of aspect ratio one and swept-back flexible twin tail with taper ratio of 0.23. This complex multidisciplinary problem is solved sequentially using three sets of equations for the fluid flow, aeroelastic response and grid deformation, using a dynamic multi-block grid structure. The computational model is pitched at 30 deg angle of attack. The freestream Mach number and Reynolds number are 0.3 and 1.25 million, respectively. The model is investigated for the inboard position of the twin tails, which corresponds to a separation distance between the twin tails of 33% of the wing span. Comparison of the time history and power spectral density responses of the tails for various distributions of the control ports are presented and discussed.

  9. Structural Conservation of the Myoviridae Phage Tail Sheath Protein Fold

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Aksyuk, Anastasia A.; Kurochkina, Lidia P.; Fokine, Andrei

    2012-02-21

    Bacteriophage phiKZ is a giant phage that infects Pseudomonas aeruginosa, a human pathogen. The phiKZ virion consists of a 1450 {angstrom} diameter icosahedral head and a 2000 {angstrom}-long contractile tail. The structure of the whole virus was previously reported, showing that its tail organization in the extended state is similar to the well-studied Myovirus bacteriophage T4 tail. The crystal structure of a tail sheath protein fragment of phiKZ was determined to 2.4 {angstrom} resolution. Furthermore, crystal structures of two prophage tail sheath proteins were determined to 1.9 and 3.3 {angstrom} resolution. Despite low sequence identity between these proteins, all ofmore » these structures have a similar fold. The crystal structure of the phiKZ tail sheath protein has been fitted into cryo-electron-microscopy reconstructions of the extended tail sheath and of a polysheath. The structural rearrangement of the phiKZ tail sheath contraction was found to be similar to that of phage T4.« less

  10. Development in helicopter tail boom strake applications in the US

    NASA Technical Reports Server (NTRS)

    Wilson, John C.; Kelley, Henry L.; Donahue, Cynthia C.; Yenni, Kenneth R.

    1988-01-01

    The use of a strake or spoiler on a helicopter tail boom to beneficially change helicopter tail boom air loads was suggested in the United States in 1975. The anticipated benefits were a change of tail boom loads to reduce required tail rotor thrust and power and improve directional control. High tail boom air loads experienced by the YAH-64 and described in 1978 led to a wind tunnel investigation of the usefullness of strakes in altering such loads on the AH-64, UH-60, and UH-1 helicopters. The wind tunnel tests of 2-D cross sections of the tail boom of each demonstrated that a strake or strakes would be effective. Several limited test programs with the U.S. Army's OH-58A, AH-64, and UH-60A were conducted which showed the effects of strakes were modest for those helicopters. The most recent flight test program, with a Bell 204B, disclosed that for the 204B the tail boom strake or strakes would provide more than a modest improvement in directional control and reduction in tail rotor power.

  11. Transport and attenuation of metal(loid)s in mine tailings amended with organic carbon: Column experiments

    NASA Astrophysics Data System (ADS)

    Lindsay, Matthew B. J.; Blowes, David W.; Ptacek, Carol J.; Condon, Peter D.

    2011-07-01

    A laboratory-scale column experiment was conducted to evaluate the effect of organic carbon amendments on the mobility of As, Cu, Fe, Mn, Mo, Ni, Pb, Sb, Tl and Zn in mine tailings. Three columns were packed with sulfide- and carbonate-rich tailings, which were amended with a 1:1 (vol.) mixture of peat and spent brewing grain at proportions of 0, 2 and 5 vol. %. A simulated input solution characterized by circumneutral pH and elevated concentrations of SO 4 and S 2O 3 was passed through the columns for 540 days. The input solution contained low concentrations of metal(loid)s during the initial 300 days and elevated concentrations thereafter. Decreases in mass transport of S 2O 3 were observed in all columns; with increased attenuation observed at 5 vol. % organic carbon content. Removal of Mn, Ni, Cu, Sb and Mo was observed in all columns during the initial 300 days. However, during this time, mobilization of Fe, As, Zn and Pb was observed, with the greatest increases in concentration observed at the higher organic carbon content. During the final 240 days, S 2O 3 removal was enhanced in columns containing organic carbon, and Fe, Mn, Ni, Tl, As and Sb removal also was observed. This study demonstrates the influence of organic carbon amendments on metal(loid) mobility in mine tailings. Decreases in mass discharge of metal(loid)s may be achieved using this technique; however, site-specific geochemical conditions must be considered before field-scale implementation.

  12. A note on trans-Planckian tail effects

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Graef, L.L.; Instituto de Física, Universidade de São Paulo, Rua do Matão travessa R, São Paulo, SP, 05508-090; Brandenberger, R.

    2015-09-09

    We study the proposal by Mersini et al. http://dx.doi.org/10.1103/PhysRevD.64.043508 that the observed dark energy might be explained by the back-reaction of the set of tail modes in a theory with a dispersion relation in which the mode frequency decays exponentially in the trans-Planckian regime. The matter tail modes are frozen out, however they induce metric fluctuations. The energy-momentum tensor with which the tail modes effect the background geometry obtains contributions from both metric and matter fluctuations. We calculate the equation of state induced by the tail modes taking into account the gravitational contribution. We find that, in contrast to themore » case of frozen super-Hubble cosmological fluctuations, in this case the matter perturbations dominate, and they yield an equation of state which to leading order takes the form of a positive cosmological constant.« less

  13. Indirect Solar Wind Measurements Using Archival Cometary Tail Observations

    NASA Astrophysics Data System (ADS)

    Zolotova, Nadezhda; Sizonenko, Yuriy; Vokhmyanin, Mikhail; Veselovsky, Igor

    2018-05-01

    This paper addresses the problem of the solar wind behaviour during the Maunder minimum. Records on plasma tails of comets can shed light on the physical parameters of the solar wind in the past. We analyse descriptions and drawings of comets between the eleventh and eighteenth century. To distinguish between dust and plasma tails, we address their colour, shape, and orientation. Based on the calculations made by F.A. Bredikhin, we found that cometary tails deviate from the antisolar direction on average by more than 10°, which is typical for dust tails. We also examined the catalogues of Hevelius and Lubieniecki. The first indication of a plasma tail was revealed only for the great comet C/1769 P1.

  14. 14 CFR 23.497 - Supplementary conditions for tail wheels.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... Structure Ground Loads § 23.497 Supplementary conditions for tail wheels. In determining the ground loads on the tail wheel and affected supporting structures, the following apply: (a) For the obstruction load, the limit ground reaction obtained in the tail down landing condition is assumed to act up and aft...

  15. 14 CFR 23.497 - Supplementary conditions for tail wheels.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... Structure Ground Loads § 23.497 Supplementary conditions for tail wheels. In determining the ground loads on the tail wheel and affected supporting structures, the following apply: (a) For the obstruction load, the limit ground reaction obtained in the tail down landing condition is assumed to act up and aft...

  16. 14 CFR 29.411 - Ground clearance: tail rotor guard.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Ground clearance: tail rotor guard. 29.411 Section 29.411 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION... System Loads § 29.411 Ground clearance: tail rotor guard. (a) It must be impossible for the tail rotor to...

  17. 14 CFR 27.411 - Ground clearance: tail rotor guard.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Ground clearance: tail rotor guard. 27.411 Section 27.411 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION... System Loads § 27.411 Ground clearance: tail rotor guard. (a) It must be impossible for the tail rotor to...

  18. 14 CFR 27.411 - Ground clearance: tail rotor guard.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Ground clearance: tail rotor guard. 27.411 Section 27.411 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION... System Loads § 27.411 Ground clearance: tail rotor guard. (a) It must be impossible for the tail rotor to...

  19. 14 CFR 29.411 - Ground clearance: tail rotor guard.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Ground clearance: tail rotor guard. 29.411 Section 29.411 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION... System Loads § 29.411 Ground clearance: tail rotor guard. (a) It must be impossible for the tail rotor to...

  20. Thresher sharks use tail-slaps as a hunting strategy.

    PubMed

    Oliver, Simon P; Turner, John R; Gann, Klemens; Silvosa, Medel; D'Urban Jackson, Tim

    2013-01-01

    The hunting strategies of pelagic thresher sharks (Alopias pelagicus) were investigated at Pescador Island in the Philippines. It has long been suspected that thresher sharks hunt with their scythe-like tails but the kinematics associated with the behaviour in the wild are poorly understood. From 61 observations recorded by handheld underwater video camera between June and October 2010, 25 thresher shark shunting events were analysed. Thresher sharks employed tail-slaps to debilitate sardines at all times of day. Hunting events comprised preparation, strike, wind-down recovery and prey item collection phases, which occurred sequentially. Preparation phases were significantly longer than the others, presumably to enable a shark to windup a tail-slap. Tail-slaps were initiated by an adduction of the pectoral fins, a manoeuvre that changed a thresher shark's pitch promoting its posterior region to lift rapidly, and stall its approach. Tail-slaps occurred with such force that they may have caused dissolved gas to diffuse out of the water column forming bubbles. Thresher sharks were able to consume more than one sardine at a time, suggesting that tail-slapping is an effective foraging strategy for hunting schooling prey. Pelagic thresher sharks appear to pursue sardines opportunistically by day and night, which may make them vulnerable to fisheries. Alopiids possess specialist pectoral and caudal fins that are likely to have evolved, at least in part, for tail-slapping. The evidence is now clear; thresher sharks really do hunt with their tails.

  1. Thresher Sharks Use Tail-Slaps as a Hunting Strategy

    PubMed Central

    Oliver, Simon P.; Turner, John R.; Gann, Klemens; Silvosa, Medel; D'Urban Jackson, Tim

    2013-01-01

    The hunting strategies of pelagic thresher sharks (Alopias pelagicus) were investigated at Pescador Island in the Philippines. It has long been suspected that thresher sharks hunt with their scythe-like tails but the kinematics associated with the behaviour in the wild are poorly understood. From 61 observations recorded by handheld underwater video camera between June and October 2010, 25 thresher shark shunting events were analysed. Thresher sharks employed tail-slaps to debilitate sardines at all times of day. Hunting events comprised preparation, strike, wind-down recovery and prey item collection phases, which occurred sequentially. Preparation phases were significantly longer than the others, presumably to enable a shark to windup a tail-slap. Tail-slaps were initiated by an adduction of the pectoral fins, a manoeuvre that changed a thresher shark's pitch promoting its posterior region to lift rapidly, and stall its approach. Tail-slaps occurred with such force that they may have caused dissolved gas to diffuse out of the water column forming bubbles. Thresher sharks were able to consume more than one sardine at a time, suggesting that tail-slapping is an effective foraging strategy for hunting schooling prey. Pelagic thresher sharks appear to pursue sardines opportunistically by day and night, which may make them vulnerable to fisheries. Alopiids possess specialist pectoral and caudal fins that are likely to have evolved, at least in part, for tail-slapping. The evidence is now clear; thresher sharks really do hunt with their tails. PMID:23874415

  2. Effect of Tourmaline-Doped on the Far Infrared Emission of Iron Ore Tailings Ceramics.

    PubMed

    Liu, Jie; Meng, Junping; Liang, Jinsheng; Zhang, Hongchen; Gu, Xiaoyang

    2016-04-01

    Iron ore tailings as secondary resources have been of great importance to many countries in the world. Their compositions are similar to that of infrared emission ceramics, but there are few reports about it. In addition, tourmaline has high infrared emission properties due to its unique structure. With the purpose of expanding functional utilization of iron ore tailings, as well as reducing the production cost of far infrared ceramics, a new kind of far infrared emission ceramics was prepared by using iron ore tailings, calcium carbonate, silica, and natural tourmaline. The ceramics powders were characterized by Fourier transform infrared spectroscope, X-ray diffraction and scanning electron microscopy, respectively. The results show that after being sintered at 1065 °C, the percentage of pseudobrookite and lattice strain of samples increased with increasing the elbaite content. Furthermore, the added tourmaline was conducive to the densification sintering of ceramics. The appearance of Li-O vibration at 734.73 cm-1, as well as the strengthened Fe-O vibration at 987.68 cm-1 were attributed to the formation of Li0.375Fe1.23Ti1.4O5 solid solution, which led the average far infrared emissivity of ceramics increase from 0.861 to 0.906 within 8-14 µm.

  3. A Tale of Two Tails: Not Just Skin Deep

    PubMed Central

    Dutta, Abhijit; Ghosh, Sudip Kumar; Mandal, Asok Kumar

    2015-01-01

    The dorsal cutaneous appendage or the so called human tail is a rare congenital anomaly protruding from the lumbo-sacro-coccygeal area. These caudal appendages are divided into true-tails and pseudo-tails. We report here two cases of congenital pseudo-tail with underlying spina bifida and lipo-meningocele. In this article we seek to emphasize that, as the skin and nervous systems are intimately linked by their similar ectodermal origin, a dorsal appendage may be regarded as a cutaneous marker of the underlying spinal dysraphism. PMID:26288414

  4. A potential role for bat tail membranes in flight control.

    PubMed

    Gardiner, James D; Dimitriadis, Grigorios; Codd, Jonathan R; Nudds, Robert L

    2011-03-30

    Wind tunnel tests conducted on a model based on the long-eared bat Plecotus auritus indicated that the positioning of the tail membrane (uropatagium) can significantly influence flight control. Adjusting tail position by increasing the angle of the legs ventrally relative to the body has a two-fold effect; increasing leg-induced wing camber (i.e., locally increased camber of the inner wing surface) and increasing the angle of attack of the tail membrane. We also used our model to examine the effects of flying with and without a tail membrane. For the bat model with a tail membrane increasing leg angle increased the lift, drag and pitching moment (nose-down) produced. However, removing the tail membrane significantly reduced the change in pitching moment with increasing leg angle, but it had no significant effect on the level of lift produced. The drag on the model also significantly increased with the removal of the tail membrane. The tail membrane, therefore, is potentially important for controlling the level of pitching moment produced by bats and an aid to flight control, specifically improving agility and manoeuvrability. Although the tail of bats is different from that of birds, in that it is only divided from the wings by the legs, it nonetheless, may, in addition to its prey capturing function, fulfil a similar role in aiding flight control.

  5. A Potential Role for Bat Tail Membranes in Flight Control

    PubMed Central

    Gardiner, James D.; Dimitriadis, Grigorios; Codd, Jonathan R.; Nudds, Robert L.

    2011-01-01

    Wind tunnel tests conducted on a model based on the long-eared bat Plecotus auritus indicated that the positioning of the tail membrane (uropatagium) can significantly influence flight control. Adjusting tail position by increasing the angle of the legs ventrally relative to the body has a two-fold effect; increasing leg-induced wing camber (i.e., locally increased camber of the inner wing surface) and increasing the angle of attack of the tail membrane. We also used our model to examine the effects of flying with and without a tail membrane. For the bat model with a tail membrane increasing leg angle increased the lift, drag and pitching moment (nose-down) produced. However, removing the tail membrane significantly reduced the change in pitching moment with increasing leg angle, but it had no significant effect on the level of lift produced. The drag on the model also significantly increased with the removal of the tail membrane. The tail membrane, therefore, is potentially important for controlling the level of pitching moment produced by bats and an aid to flight control, specifically improving agility and manoeuvrability. Although the tail of bats is different from that of birds, in that it is only divided from the wings by the legs, it nonetheless, may, in addition to its prey capturing function, fulfil a similar role in aiding flight control. PMID:21479137

  6. Strong shock implosion, approximate solution

    NASA Astrophysics Data System (ADS)

    Fujimoto, Y.; Mishkin, E. A.; Alejaldre, C.

    1983-01-01

    The self-similar, center-bound motion of a strong spherical, or cylindrical, shock wave moving through an ideal gas with a constant, γ= cp/ cv, is considered and a linearized, approximate solution is derived. An X, Y phase plane of the self-similar solution is defined and the representative curved of the system behind the shock front is replaced by a straight line connecting the mappings of the shock front with that of its tail. The reduced pressure P(ξ), density R(ξ) and velocity U1(ξ) are found in closed, quite accurate, form. Comparison with numerically obtained results, for γ= {5}/{3} and γ= {7}/{5}, is shown.

  7. Extra-domain B in oncofetal fibronectin structurally promotes fibrillar head-to-tail dimerization of extracellular matrix protein.

    PubMed

    Schiefner, André; Gebauer, Michaela; Skerra, Arne

    2012-05-18

    The type III extra-domain B (ED-B) is specifically spliced into fibronectin (Fn) during embryogenesis and neoangiogenesis, including many cancers. The x-ray structure of the recombinant four-domain fragment Fn(III)7B89 reveals a tightly associated, extended head-to-tail dimer, which is stabilized via pair-wise shape and charge complementarity. A tendency toward ED-B-dependent dimer formation in solution was supported by size exclusion chromatography and analytical ultracentrifugation. When amending the model with the known three-dimensional structure of the Fn(III)10 domain, its RGD loop as well as the adhesion synergy region in Fn(III)9-10 become displayed on the same face of the dimer; this should allow simultaneous binding of at least two integrins and, thus, receptor clustering on the cell surface and intracellular signaling. Insertion of ED-B appears to stabilize overall head-to-tail dimerization of two separate Fn chains, which, together with alternating homodimer formation via disulfide bridges at the C-terminal Fn tail, should lead to the known macromolecular fibril formation.

  8. Vertical Tail Buffeting Alleviation Using Piezoelectric Actuators: Some Results of the Actively Controlled Response of Buffet-Affected Tails (ACROBAT) Program

    NASA Technical Reports Server (NTRS)

    Moses, Robert W.

    1997-01-01

    A 1/6-scale F-18 wind-tunnel model was tested in the Transonic Dynamics Tunnel at the NASA Langley Research Center as part of the Actively Controlled Response Of Buffet Affected Tails (ACROBAT) program to assess the use of active controls in reducing vertical tail buffeting. The starboard vertical tail was equipped with an active rudder and the port vertical tail was equipped with piezoelectric actuators. The tunnel conditions were atmospheric air at a dynamic pressure of 14 psf. By using single-input-single-output control laws at gains well below the physical limits of the actuators, the power spectral density of the root strains at the frequency of the first bending mode of the vertical tail was reduced by as much as 60 percent up to angles of attack of 37 degrees. Root mean square (RMS) values of root strain were reduced by as much as 19 percent. Buffeting alleviation results when using the rudder are presented for comparison. Stability margins indicate that a constant gain setting in the control law may be used throughout the range of angle of attack tested.

  9. The formation, structure, and ageing of As-rich hydrous ferric oxide at the abandoned Sb deposit Pezinok (Slovakia)

    NASA Astrophysics Data System (ADS)

    Majzlan, Juraj; Lalinská, Bronislava; Chovan, Martin; Jurkovič, L.'ubomír; Milovská, Stanislava; Göttlicher, Jörg

    2007-09-01

    The abandoned Sb deposit Pezinok in Slovakia is a significant source of As and Sb pollution that can be traced in the upper horizons of soils kilometers downstream. The source of the metalloids are two tailing impoundments which hold ˜380,000 m 3 of mining waste. The tailings and the discharged water have circumneutral pH values (7.0 ± 0.6) because the acidity generated by the decomposition of the primary sulfides (pyrite, FeS 2; arsenopyrite, FeAsS; berthierite, FeSb 2S 4) is rapidly neutralized by the abundant carbonates. The weathering rims on the primary sulfides are iron oxides which act as very efficient scavengers of As and Sb (with up to 19.2 wt% As and 23.7 wt% Sb). In-situ μ-XANES experiments indicate that As in the weathering rims is fully oxidized (As 5+). The pore solutions in the impoundment body contain up to 81 ppm As and 2.5 ppm Sb. Once these solutions are discharged from the impoundments, they precipitate or deposit masses of As-rich hydrous ferric oxide (As-HFO) with up to 28.3 wt% As 2O 5 and 2.7 wt% Sb. All As-HFO samples are amorphous to X-rays. They contain Fe and As in their highest oxidation state and in octahedral and tetrahedral coordination, respectively, as suggested by XANES and EXAFS studies on Fe K and As K edges. The iron octahedra in the As-HFO share edges to form short single chains and the chains polymerize by sharing edges or corners with the adjacent units. The arsenate ions attach to the chains in a bidentate-binuclear and monodentate fashion. In addition, hydrogen-bonded complexes may exist to satisfy the bonding requirements of all oxygen atoms in the first coordination sphere of As 5+. Structural changes in the As-HFO samples were traced by chemical analyses and Fe EXAFS spectroscopy during an ageing experiment. As the samples age, As becomes more easily leachable. EXAFS spectra show a discernible trend of increasing number of Fe-Fe pairs at a distance of 3.3-3.5 Å, that is, increasing polymerization of the iron

  10. Radon emanation from backfilled mill tailings in underground uranium mine.

    PubMed

    Sahu, Patitapaban; Mishra, Devi Prasad; Panigrahi, Durga Charan; Jha, Vivekananda; Patnaik, R Lokeswara; Sethy, Narendra Kumar

    2014-04-01

    Coarser mill tailings used as backfill to stabilize the stoped out areas in underground uranium mines is a potential source of radon contamination. This paper presents the quantitative assessment of radon emanation from the backfilled tailings in Jaduguda mine, India using a cylindrical accumulator. Some of the important parameters such as (226)Ra activity concentration, bulk density, bulk porosity, moisture content and radon emanation factor of the tailings affecting radon emanation were determined in the laboratory. The study revealed that the radon emanation rate of the tailings varied in the range of 0.12-7.03 Bq m(-2) s(-1) with geometric mean of 1.01 Bq m(-2) s(-1) and geometric standard deviation of 3.39. An increase in radon emanation rate was noticed up to a moisture saturation of 0.09 in the tailings, after which the emanation rate gradually started declining with saturation due to low diffusion coefficient of radon in the saturated tailings. Radon emanation factor of the tailings varied in the range of 0.08-0.23 with the mean value of 0.21. The emanation factor of the tailings with moisture saturation level over 0.09 was found to be about three times higher than that of the absolutely dry tailings. The empirical relationship obtained between (222)Rn emanation rate and (226)Ra activity concentration of the tailings indicated a significant positive linear correlation (r = 0.95, p < 0.001). This relationship may be useful for quick prediction of radon emanation rate from the backfill material of similar nature. Copyright © 2014 Elsevier Ltd. All rights reserved.

  11. Effect of Configuration Pitching Motion on Twin Tail Buffet Response

    NASA Technical Reports Server (NTRS)

    Sheta, Essam F.; Kandil, Osama A.

    1998-01-01

    The effect of dynamic pitch-up motion of delta wing on twin-tail buffet response is investigated. The computational model consists of a delta wing-twin tail configuration. The computations are carried out on a dynamic multi-block grid structure. This multidisciplinary problem is solved using three sets of equations which consists of the unsteady Navier-Stokes equations, the aeroelastic equations, and the grid displacement equations. The configuration is pitched-up from zero up to 60 deg. angle of attack, and the freestream Mach number and Reynolds number are 0.3 and 1.25 million, respectively. With the twin tail fixed as rigid surfaces and with no-forced pitch-up motion, the problem is solved for the initial flow conditions. Next, the problem is solved for the twin-tail response for uncoupled bending and torsional vibrations due to the unsteady loads on the twin tail and due to the forced pitch-up motion. The dynamic pitch-up problem is also solved for the flow response with the twin tail kept rigid. The configuration is investigated for inboard position of the twin tail which corresponds to a separation distance between the twin tail of 33% wing chord. The computed results are compared with the available experimental data.

  12. Tail regeneration affects the digestive performance of a Mediterranean lizard

    NASA Astrophysics Data System (ADS)

    Sagonas, Kostas; Karambotsi, Niki; Bletsa, Aristoula; Reppa, Aikaterini; Pafilis, Panayiotis; Valakos, Efstratios D.

    2017-04-01

    In caudal autotomy, lizards shed their tail to escape from an attacking predator. Since the tail serves multiple functions, caudal regeneration is of pivotal importance. However, it is a demanding procedure that requires substantial energy and nutrients. Therefore, lizards have to increase energy income to fuel the extraordinary requirements of the regenerating tail. We presumed that autotomized lizards would adjust their digestion to acquire this additional energy. To clarify the effects of tail regeneration on digestion, we compared the digestive performance before autotomy, during regeneration, and after its completion. Tail regeneration indeed increased gut passage time but did not affect digestive performance in a uniform pattern: though protein income was maximized, lipid and sugar acquisition remained stable. This divergence in proteins may be attributed to their particular role in tail reconstruction, as they are the main building blocks for tissue formation.

  13. Orphan Stars Found in Long Galaxy Tail

    NASA Astrophysics Data System (ADS)

    2007-09-01

    Astronomers have found evidence that stars have been forming in a long tail of gas that extends well outside its parent galaxy. This discovery suggests that such "orphan" stars may be much more prevalent than previously thought. The comet-like tail was observed in X-ray light with NASA's Chandra X-ray Observatory and in optical light with the Southern Astrophysical Research (SOAR) telescope in Chile. The feature extends for more than 200,000 light years and was created as gas was stripped from a galaxy called ESO 137-001 that is plunging toward the center of Abell 3627, a giant cluster of galaxies. "This is one of the longest tails like this we have ever seen," said Ming Sun of Michigan State University, who led the study. "And, it turns out that this is a giant wake of creation, not of destruction." Chandra X-ray Image of ESO 137-001 and Tail in Abell 3627 Chandra X-ray Image of ESO 137-001 and Tail in Abell 3627 The observations indicate that the gas in the tail has formed millions of stars. Because the large amounts of gas and dust needed to form stars are typically found only within galaxies, astronomers have previously thought it unlikely that large numbers of stars would form outside a galaxy. "This isn't the first time that stars have been seen to form between galaxies," said team member Megan Donahue, also of MSU. "But the number of stars forming here is unprecedented." The evidence for star formation in this tail includes 29 regions of ionized hydrogen glowing in optical light, thought to be from newly formed stars. These regions are all downstream of the galaxy, located in or near the tail. Two Chandra X-ray sources are near these regions, another indication of star formation activity. The researchers believe the orphan stars formed within the last 10 million years or so. The stars in the tail of this fast-moving galaxy, which is some 220 million light years away, would be much more isolated than the vast majority of stars in galaxies. H-alpha Image of

  14. Cell lineage tracing during Xenopus tail regeneration.

    PubMed

    Gargioli, Cesare; Slack, Jonathan M W

    2004-06-01

    The tail of the Xenopus tadpole will regenerate following amputation, and all three of the main axial structures - the spinal cord, the notochord and the segmented myotomes - are found in the regenerated tail. We have investigated the cellular origin of each of these three tissue types during regeneration. We produced Xenopus laevis embryos transgenic for the CMV (Simian Cytomegalovirus) promoter driving GFP (Green Fluorescent Protein) ubiquitously throughout the embryo. Single tissues were then specifically labelled by making grafts at the neurula stage from transgenic donors to unlabelled hosts. When the hosts have developed to tadpoles, they carry a region of the appropriate tissue labelled with GFP. These tails were amputated through the labelled region and the distribution of labelled cells in the regenerate was followed. We also labelled myofibres using the Cre-lox method. The results show that the spinal cord and the notochord regenerate from the same tissue type in the stump, with no labelling of other tissues. In the case of the muscle, we show that the myofibres of the regenerate arise from satellite cells and not from the pre-existing myofibres. This shows that metaplasia between differentiated cell types does not occur, and that the process of Xenopus tail regeneration is more akin to tissue renewal in mammals than to urodele tail regeneration.

  15. Predicting arsenic concentrations in porewaters of buried uranium mill tailings

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Langmuir, D.; Mahoney, J.; MacDonald, A.

    The proposed JEB Tailings Management Facility (TMF) to be emplaced below the groundwater table in northern Saskatchewan, Canada, will contain uranium mill tailings from McClean Lake, Midwest and Cigar Lake ore bodies, which are high in arsenic (up to 10%) and nickel (up to 5%). A serious concern is the possibility that high arsenic and nickel concentrations may be released from the buried tailings, contaminating adjacent groundwaters and a nearby lake. Laboratory tests and geochemical modeling were performed to examine ways to reduce the arsenic and nickel concentrations in TMF porewaters so as to minimize such contamination from tailings buriedmore » for 50 years and longer. The tests were designed to mimic conditions in the mill neutralization circuit (3 hr tests at 25 C), and in the TMF after burial (5--49 day aging tests). The aging tests were run at 50, 25 and 4 C (the temperature in the TMF). In order to optimize the removal of arsenic by adsorption and precipitation, ferric sulfate was added to tailings raffinates having Fe/As ratios of less than 3--5. The acid raffinates were then neutralized by addition of slaked lime to nominal pH values of 7, 8, or 9. Analysis and modeling of the test results showed that with slaked lime addition to acid tailings raffinates, relatively amorphous scorodite (ferric arsenate) precipitates near pH 1, and is the dominant form of arsenate in slake limed tailings solids except those high in Ni and As and low in Fe, in which cabrerite-annabergite (Ni, Mg, Fe(II) arsenate) may also precipitate near pH 5--6. In addition to the arsenate precipitates, smaller amounts of arsenate are also adsorbed onto tailings solids. The aging tests showed that after burial of the tailings, arsenic concentrations may increase with time from the breakdown of the arsenate phases (chiefly scorodite). However, the tests indicate that the rate of change decreases and approaches zero after 72 hrs at 25 C, and may equal zero at all times in the TMF at 4

  16. PSR J0357+3205: THE TAIL OF THE TURTLE

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Marelli, M.; De Luca, A.; Salvetti, D.

    2013-03-01

    Using a new XMM-Newton observation, we have characterized the X-ray properties of the middle-aged radio-quiet {gamma}-ray pulsar J0357+3205 (named Morla) and its tail. The X-ray emission from the pulsar is consistent with a magnetospheric non-thermal origin plus a thermal emission from a hot spot (or hot spots). The lack of a thermal component from the whole surface makes Morla the coldest neutron star in its age range. We found marginal evidence for a double-peaked modulation of the X-ray emission. The study of the 9' long tail confirmed the lack of extended emission near the pulsar itself. The tail shows amore » very asymmetric brightness profile and its spectrum lacks any spatial variation. We found the nebular emission to be inconsistent with a classical bow shock, ram-pressure-dominated pulsar wind nebula. We propose thermal bremsstrahlung as an alternative mechanism for Morla's tail emission. In this scenario, the tail emission comes from the shocked interstellar medium (ISM) material heated up to X-ray temperatures. This can fully explain the peculiar features of the tail, assuming a hot, moderately dense ISM around the pulsar. For a bremsstrahlung-emitting tail, we can estimate the pulsar distance to be between 300 and 900 pc. A pulsar velocity of {approx}1900 km s{sup -1} is required, which would make Morla the pulsar with the largest velocity, and high inclination angles (>70 Degree-Sign ) are preferred. We propose Morla's nebula as the first example of a new 'turtle's tail' class of thermally emitting nebulae associated with high-velocity pulsars.« less

  17. The tails of the satellite auroral footprints at Jupiter

    NASA Astrophysics Data System (ADS)

    Bonfond, B.; Saur, J.; Grodent, D.; Badman, S. V.; Bisikalo, D.; Shematovich, V.; Gérard, J.-C.; Radioti, A.

    2017-08-01

    The electromagnetic interaction between Io, Europa, and Ganymede and the rotating plasma that surrounds Jupiter has a signature in the aurora of the planet. This signature, called the satellite footprint, takes the form of a series of spots located slightly downstream of the feet of the field lines passing through the moon under consideration. In the case of Io, these spots are also followed by an extended tail in the downstream direction relative to the plasma flow encountering the moon. A few examples of a tail for the Europa footprint have also been reported in the northern hemisphere. Here we present a simplified Alfvénic model for footprint tails and simulations of vertical brightness profiles for various electron distributions, which favor such a model over quasi-static models. We also report here additional cases of Europa footprint tails, in both hemispheres, even though such detections are rare and difficult. Furthermore, we show that the Ganymede footprint can also be followed by a similar tail. Finally, we present a case of a 320° long Io footprint tail, while other cases in similar configurations do not display such a length.

  18. Hydrodynamic Characteristics of a Low-drag, Planing-tail Flying-boat Hull

    NASA Technical Reports Server (NTRS)

    Suydam, Henry B

    1948-01-01

    The hydrodynamic characteristics of a flying-boat incorporating a low-drag, planing-tail hull were determined from model tests made in Langley tank number 2 and compared with tests of the same flying boat incorporating a conventional-type hull. The planing-tail model, with which stable take-offs were possible for a large range of elevator positions at all center-of-gravity locations tested, had more take-off stability than the conventional model. No upper-limit porpoising was encountered by the planing-tail model. The maximum changes in rise during landings were lower for the planing-tail model than for the conventional model at most contact trims, an indication of improved landing stability for the planing-tail model. The hydrodynamic resistance of the planing-tail hull was lower than the conventional hull at all speeds, and the load-resistance ratio was higher for the planing-tail hull, being especially high at the hump. The static trim of the planing-tail hull was much higher than the conventional hull, but the variation of trim with speed during take-off was smaller.

  19. Hydrogen-bond rich ionic liquids with hydroxyl cationic tails

    NASA Astrophysics Data System (ADS)

    Deng, Li; Shi, Rui; Wang, Yanting; Ou-Yang, Zhong-Can

    2013-02-01

    To investigate if the amphiphilic feature exhibited in ionic liquids (ILs) with nonpolar cationic tails still exists in ILs with polar tails, by performing molecular dynamics simulations for 1-(8-hydroxyoctyl)-3-methyl-imidazolium nitrate (COH) and 1-octyl-3-methyl-imidazolium nitrate (C8), we found that, in COH, cationic tail groups can no longer aggregate to form separated nonpolar tail domains, instead hydroxyl groups form a rich number of hydrogen bonds with other groups, indicating that the hydroxyl substituent changes the IL system from an amphiphilic liquid to a polar liquid. Due to the large amount of hydrogen bonds, COH has slower dynamics than C8.

  20. 10 CFR Appendix A to Part 40 - Criteria Relating to the Operation of Uranium Mills and the Disposition of Tailings or Wastes...

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... to be relied upon for seepage control, tests must be conducted with representative tailings solutions... itself. (6) The design requirements in this criterion for longevity and control of radon releases apply... licensee shall control, minimize, or eliminate post-closure escape of nonradiological hazardous...

  1. Effectiveness of Flow Control for Alleviation of Twin-Tail Buffet

    NASA Technical Reports Server (NTRS)

    Sheta, Essam F.; Kandil, Osama A.; Yang, Zhi

    1998-01-01

    Effectiveness of active flow control for twin- tail buffet alleviation is investigated. Tangen- tial leading-edge blowing (TLEB) and flow suction along the vortex cores (FSVC) of the lead- ing edges of the delta wing are used to delay the vortex breakdown flow upstream of the twin tail. The combined effect of the TLEB and FSVC is also investigated. A parametric study of the effects of the spanwise position of the suction tubes and volumetric suction flow rate on the twin-tail buffet response are also investigated. The TLEB moves the path of leading-edge vortices laterally towards the twin tail, which increases the aero- dynamic damping on the tails. The FSVC effectively delays the breakdown location at high angles of attack. The computational model consists of a sharp-edged delta wing of aspect ratio one and swept-back flexible twin tail with taper ratio of 0.23. This complex multidisciplinary problem is solved sequentially using three sets of equations for the fluid flow, aeroelastic response and grid deformation, on a dynamic multi-block grid structure. The computational model is pitched at 30 deg. angle of attack. The freestream Mach number and Reynolds number are 0.3 and 1.25 million, respectively. The model is investigated for the inboard position of the twin tails, which corresponds to a separation distance between the twin tails of 33% of the wing span.

  2. Can tail damage outbreaks in the pig be predicted by behavioural change?

    PubMed

    Larsen, Mona Lilian Vestbjerg; Andersen, Heidi Mai-Lis; Pedersen, Lene Juul

    2016-03-01

    Tail biting, resulting in outbreaks of tail damage in pigs, is a multifactorial welfare and economic problem which is usually partly prevented through tail docking. According to European Union legislation, tail docking is not allowed on a routine basis; thus there is a need for alternative preventive methods. One strategy is the surveillance of the pigs' behaviour for known preceding indicators of tail damage, which makes it possible to predict a tail damage outbreak and prevent it in proper time. This review discusses the existing literature on behavioural changes observed prior to a tail damage outbreak. Behaviours found to change prior to an outbreak include increased activity level, increased performance of enrichment object manipulation, and a changed proportion of tail posture with more tails between the legs. Monitoring these types of behaviours is also discussed for the purpose of developing an automatic warning system for tail damage outbreaks, with activity level showing promising results for being monitored automatically. Encouraging results have been found so far for the development of an automatic warning system; however, there is a need for further investigation and development, starting with the description of the temporal development of the predictive behaviour in relation to tail damage outbreaks. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. Effect of Solute Size on Transport in Structured Porous Media

    NASA Astrophysics Data System (ADS)

    Hu, Qinhong; Brusseau, Mark L.

    1995-07-01

    The purpose of this work was to investigate the effect of solute size on transport in structured porous media. Miscible displacement experiments were performed with tracers of different sizes (i.e., tritiated water (3H2O), pentafluorobenzoate (PFBA), 2,4-dichlorophenoxyacetic acid (2,4-D), and hydroxypropyl-β-cyclodextrin (HPCD)) in aggregated, stratified, and macroporous media. The breakthrough curves exhibited both early breakthrough and tailing, indicative of nonideal transport in these structured media. Comparison of breakthrough curves revealed that the extent of nonideality (e.g., tailing) was HPCD > PFBA, 2,4-D > 3H2O. This behavior is consistent with the impact of solute size on the relative degree of "nonequilibrium" experienced by solutes whose transport is constrained by diffusive mass transfer. The capability of the first-order, dual-porosity mobile-immobile model to represent solute transport in these structured systems was evaluated by comparing independently determined values of the input parameters to values obtained by curve fitting of the experimental measurements. The calculated and optimized values compared quite well for the aggregated and stratified media, but not for the macroporous media. xperiments performed with tracers of different size are useful for characterizing the nature of the porous medium through which transport is occurring.

  4. Curved tails in polymerization-based bacterial motility

    NASA Astrophysics Data System (ADS)

    Rutenberg, Andrew D.; Grant, Martin

    2001-08-01

    The curved actin ``comet-tail'' of the bacterium Listeria monocytogenes is a visually striking signature of actin polymerization-based motility. Similar actin tails are associated with Shigella flexneri, spotted-fever Rickettsiae, the Vaccinia virus, and vesicles and microspheres in related in vitro systems. We show that the torque required to produce the curvature in the tail can arise from randomly placed actin filaments pushing the bacterium or particle. We find that the curvature magnitude determines the number of actively pushing filaments, independent of viscosity and of the molecular details of force generation. The variation of the curvature with time can be used to infer the dynamics of actin filaments at the bacterial surface.

  5. Metallicity gradients in tidal tails and merging systems

    NASA Astrophysics Data System (ADS)

    Torres-Flores, S.; Scarano, S., Jr.; Olave, D.; Alfaro, M.; Mendes de Oliveira, C.; de Mello, D. F.; Carrasco, E. R.; Amram, P.; Plana, H.

    2014-10-01

    We present an analysis of the metal distribution in the tidal tails of two interacting systems and in the main body of a galaxy merger: NGC92, NGC6845 and HCG31, respectively. Using Gemini/GMOS spectroscopic data, we found no metallicity gradients for the tail of NGC92. The abundances in the tail are similar to the values displayed by the central regions of NGC92. This fact suggests that gas mixing triggered by the interaction produces a flattening in the metallicity distribution of this system. For the system NGC6845, we found that regions located in the tail have similar abundances to one source located in the inner region of this galaxy, also suggesting a flat metal distribution. For HCG 31 we found an inhomogeneous metal distribution for the central region. Apparently, each star forming complex keeps its metal abundance despite the strong gravitational interaction that this system suffered. In the case of the tidal tails, our results support the scenario in which gas mixing produces a flattening in the metal distribution. However, we suggest that the star formation is an important mechanism in enhancing the oxygen abundance of these structures.

  6. Mine tailings composition in a historic site: implications for ecological restoration.

    PubMed

    Courtney, R

    2013-02-01

    Ecological restoration, using tolerant plant species and nutrient additions, is a low-cost option to decrease environmental risks associated with mine tailings. An attempt was previously made to establish such a vegetation cover on an abandoned tailings facility in Southern Ireland. Historically, the tailings site has been prone to dusting and is a potential source of contamination to the surrounding environment. The site was examined to determine the success of the previous restoration plan used to revegetate the site and to determine its suitability for further restoration. Three distinct floristic areas were identified (grassland, poor grassland and bare area) based on herbage compositions and elemental analysis. Surface and subsurface samples were taken to characterise tailings from within these areas of the tailings site. The pH of bare surface tailings (pH, 2.7) was significantly more acidic (p < 0.5) than in other areas. Additionally, negligible net neutralising potential resulted in the tailings being hostile to plant growth. Total metal concentrations in tailings were high (c. 10,000 mg kg(-1) for Pb and up to 20,000 mg kg(-1) for Zn). DTPA-extractable Zn and Pb were 16 and 11 % of the total amount, respectively. Metal content in grasses growing on some areas of the tailings were elevated and demonstrated the inability of the tailings to support sustainable plant growth. Due to the inherently hostile characteristics of these areas, future restoration work will employ capping with a barrier layer.

  7. AGES OF STAR CLUSTERS IN THE TIDAL TAILS OF MERGING GALAXIES

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Mulia, A. J.; Chandar, R.; Whitmore, B. C.

    We study the stellar content in the tidal tails of three nearby merging galaxies, NGC 520, NGC 2623, and NGC 3256, using BVI imaging taken with the Advanced Camera for Surveys on board the Hubble Space Telescope. The tidal tails in all three systems contain compact and fairly massive young star clusters, embedded in a sea of diffuse, unresolved stellar light. We compare the measured colors and luminosities with predictions from population synthesis models to estimate cluster ages and find that clusters began forming in tidal tails during or shortly after the formation of the tails themselves. We find amore » lack of very young clusters (≤10 Myr old), implying that eventually star formation shuts off in the tails as the gas is used up or dispersed. There are a few clusters in each tail with estimated ages that are older than the modeled tails themselves, suggesting that these may have been stripped out from the original galaxy disks. The luminosity function of the tail clusters can be described by a single power-law, dN/dL ∝ L{sup α}, with −2.6 < α < −2.0. We find a stellar age gradient across some of the tidal tails, which we interpret as a superposition of (1) newly formed stars and clusters along the dense center of the tail and (2) a sea of broadly distributed, older stellar material ejected from the progenitor galaxies.« less

  8. Effects of plant growth-promoting bacteria isolated from copper tailings on plants in sterilized and non-sterilized tailings.

    PubMed

    Liu, Weiqiu; Yang, Chao; Shi, Si; Shu, Wensheng

    2014-02-01

    Ten strains of Cu-tolerant bacteria with potential plant growth-promoting ability were isolated by selecting strains with the ability to use 1-aminocyclopropane-1-carboxylate as a sole nitrogen source (designated ACC-B) or fix nitrogen (designated FLN-B) originating from the rhizosphere of plants growing on copper tailings. All 10 strains proved to have intrinsic ability to produce indole acetic acid and siderophores, and most of them could mobilize insoluble phosphate. In addition, a greenhouse study showed that ACC-B, FLN-B and a mixture of both had similar, potent ability to stimulate growth of Pennisetum purpureum, Medicago sativa and Oenothera erythrosepala plants grown on sterilized tailings. For instance, above-ground biomass of P. purpureum was 278-357% greater after 60d growth on sterilized tailings in their presence. They could also significantly promote the growth of the plants grown on non-sterilized tailings, though the growth-promoting effects were much weaker. So, strategies for using of the plant growth-promoting bacteria in the practice of phytoremediation deserve further studies to get higher growth-promoting efficiency. Copyright © 2013 Elsevier Ltd. All rights reserved.

  9. [Assessment of anti-tremorogenic drugs--nicotine-induced tail-tremor model].

    PubMed

    Suemaru, K; Kawasaki, H; Gomita, Y

    1997-06-01

    The repeated administration of nicotine at small doses, which do not produce whole body tremor or convulsion, causes tremor only in the tail (tail-tremor) of rats. The tremor is accompanied by locomotor hyperactivity without rigidity and immobility of the whole body, suggesting that the nicotine-induced tail-tremor model is useful for studying the mechanism underlying tremor associated with movement. The tail-tremor induced by nicotine was suppressed by mecamylamine, a nicotinic antagonist, but not by atropine or scopolamine, muscalinic antagonists. Moreover, the tail-tremor was suppressed by the beta-blockers propranolol and pindolol, as well as the benzodiazepines diazepam and clonazepam. Tremor at rest is observed only in Parkinson's disease, which is improved with anti-muscalinic drugs. Essential tremor is one of the typical tremors connected with movement (postural and kinetic tremor) and is improved with beta-blocker. These findings and results suggest that nicotine-induced tail-tremor is useful for the study of essential tremor in animal models.

  10. Modeling of Longitudinal Unsteady Aerodynamics of a Wing-Tail Combination

    NASA Technical Reports Server (NTRS)

    Klein, Vladislav

    1999-01-01

    Aerodynamic equations for the longitudinal motion of an aircraft with a horizontal tail were developed. In this development emphasis was given on obtaining model structure suitable for model identification from experimental data. The resulting aerodynamic models included unsteady effects in the form of linear indicial functions. These functions represented responses in the lift on the wing and tail alone, and interference between those two lifting surfaces. The effect of the wing on the tail was formulated for two different expressions concerning the downwash angle at the tail. The first expression used the Cowley-Glauert approximation known-as "lag-in-downwash," the second took into account growth of the wing circulation and delay in the development of the lift on the tail. Both approaches were demonstrated in two examples using the geometry of a fighter aircraft and a large transport. It was shown that the differences in the two downwash formulations would increase for an aircraft with long tail arm performing low-speed, rapid maneuvers.

  11. Managing 'tail liability'.

    PubMed

    Frese, Richard C; Weber, Ryan J

    2013-11-01

    To reduce and control their level of tail liability, hospitals should: Utilize a self-insurance vehicle; Consider combined limits between the hospital and physicians; Communicate any program changes to the actuary, underwriter, and auditor; Continue risk management and safety practices; Ensure credit is given to the organization's own medical malpractice program.

  12. Membrane Association of the PTEN Tumor Suppressor: Electrostatic Interaction with Phos-phatidylserine-Containing Bilayers and Regulatory Role of the C-Terminal Tail

    PubMed Central

    Shenoy, Siddharth S.; Nanda, Hirsh; Lösche, Mathias

    2012-01-01

    The phosphatidylinositolphosphate phosphatase PTEN is the second most frequently mutated protein in human tumors. Its membrane association, allosteric activation and membrane dissociation are poorly understood. We recently reported PTEN binding affinities to membranes of different compositions and a preliminary investigation of the protein-membrane complex with neutron reflectometry (NR). Here we use NR to validate molecular dynamics (MD) simulations of the protein and study conformational differences of the protein in solution and on anionic membranes. NR shows that full-length PTEN binds to such membranes roughly in the conformation and orientation suggested by the crystal structure of a truncated PTEN protein, in contrast with a recently presented model which suggested that membrane binding depends critically on the SUMOylation of the CBR3 loop of PTEN’s C2 domain. Our MD simulations confirm that PTEN is peripherally bound to the bilayer surface and show slight differences of the protein structure in solution and in the membrane-bound state, where the protein body flattens against the bilayer surface. PTEN’s C2 domain binds phosphatidylserine (PS) tightly through its CBR3 loop, and its phosphatase domain also forms electrostatic interactions with PS. NR and MD results show consistently that PTEN’s unstructured, anionic C-terminal tail is repelled from the bilayer surface. In contrast, this tail is tightly tugged against the C2 domain in solution, partially obstructing the membrane-binding interface of the protein. Arresting the C-terminal tail in this conformation by phosphorylation may provide a control mechanism for PTEN’s membrane binding and activity. PMID:23073177

  13. Weathering of primary minerals and mobility of major elements in soils affected by an accidental spill of pyrite tailing.

    PubMed

    Martín, Francisco; Diez, María; García, Inés; Simón, Mariano; Dorronsoro, Carlos; Iriarte, Angel; Aguilar, José

    2007-05-25

    In the present work, soil profiles were sampled 40 days and three years after an accidental pyrite tailing spill from the Aznalcóllar mine (S Spain) in order to figure out the effects of the acidic solution draining from the tailing. The composition of the acidic solution, the mineralogy, and the total and soluble content of the major elements were analysed at varying depths. The results show a weathering process of carbonates and of primary silicates. Calcium released is leached or reacts with the sulphate ions to form gypsum. Magnesium, aluminium and potassium tend to leach from the uppermost millimetres of the soil, accumulating where the pH>/=5.0; also the iron, probably forming more or less complex hydroxysulphates, precipitate in the upper 5 cm. The strong releasing of soluble salts increases the electrical conductivity, while the soluble potassium tends to decrease in the uppermost part of the soil due to the neoformation of jarosite. Iron is soluble only where the pH

  14. Identification of chromosomal locations associated with tail biting and being a victim of tail-biting behaviour in the domestic pig (Sus scrofa domesticus).

    PubMed

    Wilson, Kaitlin; Zanella, Ricardo; Ventura, Carlos; Johansen, Hanne Lind; Framstad, Tore; Janczak, Andrew; Zanella, Adroaldo J; Neibergs, Holly Louise

    2012-11-01

    The objective of this study was to identify loci associated with tail biting or being a victim of tail biting in Norwegian crossbred pigs using a genome-wide association study with PLINK case-control analysis. DNA was extracted from hair or blood samples collected from 98 trios of crossbred pigs located across Norway. Each trio came from the same pen and consisted of one pig observed to initiate tail biting, one pig which was the victim of tail biting and a control pig which was not involved in either behaviour. DNA was genotyped using the Illumina PorcineSNP60 BeadChip whole-genome single-nucleotide polymorphism (SNP) assay. After quality assurance filtering, 53,952 SNPs remained comprising 74 animals (37 pairs) for the tail biter versus control comparison and 53,419 SNPs remained comprising 80 animals (40 pairs) for the victim of tail biting versus control comparison. An association with being a tail biter was observed on Sus scrofa chromosome 16 (SSC16; p = 1.6 × 10(-5)) and an unassigned chromosome (p = 3.9 × 10(-5)). An association with being the victim of tail biting was observed on Sus scrofa chromosomes 1 (SSC1; p = 4.7 × 10(-5)), 9 (SSC9; p = 3.9 × 10(-5)), 18 (SSC18; p = 7 × 10(-5) for 9,602,511 bp, p = 3.4 × 10(-5) for 9,653,881 bp and p = 5.3 × 10(-5) for 29,577,783 bp) and an unassigned chromosome (p = 6.1 × 10(-5)). An r(2) = 0.96 and a D' = 1 between the two SNPs at 9 Mb on SSC18 indicated extremely high linkage disequilibrium, suggesting that these two markers represent a single locus. These results provide evidence of a moderate genetic association between the propensity to participate in tail-biting behaviour and the likelihood of becoming a victim of this behaviour.

  15. A review on in situ phytoremediation of mine tailings.

    PubMed

    Wang, Li; Ji, Bin; Hu, Yuehua; Liu, Runqing; Sun, Wei

    2017-10-01

    Mine tailings are detrimental to natural plant growth due to their physicochemical characteristics, such as high pH, high salinity, low water retention capacity, high heavy metal concentrations, and deficiencies in soil organic matter and fertility. Thus, the remediation of mine tailings has become a key issue in environmental science and engineering. Phytoremediation, an in situ cost-effective technology, is emerging as the most promising remediation method for mine tailings by introducing tolerant plant species. It is particularly effective in dealing with large-area mine tailings with shallow contamination of organic, nutrient and metal pollutants. In this review, the background, concepts and applications of phytoremediation are comprehensively discussed. Furthermore, proper amendments used to improve the physical, chemical and biological properties of mine tailings are systematically reviewed and compared. Emphasis is placed on the types and characteristics of tolerant plants and their role in phytoremediation. Moreover, the role of microorganisms and their mechanism in phytoremediation are also discussed in-depth. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. The planarian regeneration transcriptome reveals a shared but temporally shifted regulatory program between opposing head and tail scenarios.

    PubMed

    Kao, Damian; Felix, Daniel; Aboobaker, Aziz

    2013-11-16

    Planarians can regenerate entire animals from a small fragment of the body. The regenerating fragment is able to create new tissues and remodel existing tissues to form a complete animal. Thus different fragments with very different starting components eventually converge on the same solution. In this study, we performed an extensive RNA-seq time-course on regenerating head and tail fragments to observe the differences and similarities of the transcriptional landscape between head and tail fragments during regeneration. We have consolidated existing transcriptomic data for S. mediterranea to generate a high confidence set of transcripts for use in genome wide expression studies. We performed a RNA-seq time-course on regenerating head and tail fragments from 0 hours to 3 days. We found that the transcriptome profiles of head and tail regeneration were very different at the start of regeneration; however, an unexpected convergence of transcriptional profiles occurred at 48 hours when head and tail fragments are still morphologically distinct. By comparing differentially expressed transcripts at various time-points, we revealed that this divergence/convergence pattern is caused by a shared regulatory program that runs early in heads and later in tails.Additionally, we also performed RNA-seq on smed-prep(RNAi) tail fragments which ultimately fail to regenerate anterior structures. We find the gene regulation program in response to smed-prep(RNAi) to display the opposite regulatory trend compared to the previously mentioned share regulatory program during regeneration. Using annotation data and comparative approaches, we also identified a set of approximately 4,800 triclad specific transcripts that were enriched amongst the genes displaying differential expression during the regeneration time-course. The regeneration transcriptome of head and tail regeneration provides us with a rich resource for investigating the global expression changes that occurs during

  17. 10 CFR Appendix A to Part 40 - Criteria Relating to the Operation of Uranium Mills and the Disposition of Tailings or Wastes...

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... to be relied upon for seepage control, tests must be conducted with representative tailings solutions... licensee shall control, minimize, or eliminate post-closure escape of nonradiological hazardous... beyond the control of the licensee. The phrase permits consideration of the cost of compliance only to...

  18. A tail like no other. The RPC-MAG view of Rosetta's tail excursion at comet 67P/Churyumov-Gerasimenko

    NASA Astrophysics Data System (ADS)

    Volwerk, Martin; Goetz, Charlotte; Richter, Ingo; Delva, Magda; Ostaszewski, Katharina; Schwingenschuh, Konrad; Glassmeier, Karl-Heinz

    2018-06-01

    Context. The Rosetta Plasma Consortium (RPC) magnetometer (MAG) data during the tail excursion in March-April 2016 are used to investigate the magnetic structure of and activity in the tail region of the weakly outgassing comet 67P/Churyumov-Gerasimenko (67P). Aims: The goal of this study is to compare the large scale (near) tail structure with that of earlier missions to strong outgassing comets, and the small scale turbulent energy cascade (un)related to the singing comet phenomenon. Methods: The usual methods of space plasma physics are used to analyse the magnetometer data, such as minimum variance analysis, spectral analysis, and power law fitting. Also the cone angle and clock angle of the magnetic field are calculated to interpret the data. Results: It is found that comet 67P does not have a classical draped magnetic field and no bi-lobal tail structure at this late stage of the mission when the comet is already at 2.7 AU distance from the Sun. The main magnetic field direction seems to be more across the tail direction, which may implicate an asymmetric pick-up cloud. During periods of singing comet activity the propagation direction of the waves is at large angles with respect to the magnetic field and to the radial direction towards the comet. Turbulent cascade of magnetic energy from large to small scales is different in the presence of singing as without it.

  19. An Evolutionarily Conserved Family of Virion Tail Needles Related to Bacteriophage P22 gp26: Correlation between Structural Stability and Length of the -Helical Trimeric Coiled Coil

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Bhardwaj, A.; Walker-Kopp, N; Casjens, S

    2009-01-01

    Bacteriophages of the Podoviridae family use short noncontractile tails to inject their genetic material into Gram-negative bacteria. In phage P22, the tail contains a thin needle, encoded by the phage gene 26, which is essential both for stabilization and for ejection of the packaged viral genome. Bioinformatic analysis of the N-terminal domain of gp26 (residues 1-60) led us to identify a family of genes encoding putative homologues of the tail needle gp26. To validate this idea experimentally and to explore their diversity, we cloned the gp26-like gene from phages HK620, Sf6 and HS1, and characterized these gene products in solution.more » All gp26-like factors contain an elongated {alpha}-helical coiled-coil core consisting of repeating, adjacent trimerization heptads and form trimeric fibers with length ranging between about 240 to 300 {angstrom}. gp26 tail needles display a high level of structural stability in solution, with Tm (temperature of melting) between 85 and 95 C. To determine how the structural stability of these phage fibers correlates with the length of the {alpha}-helical core, we investigated the effect of insertions and deletions in the helical core. In the P22 tail needle, we identified an 85-residue-long helical domain, termed MiCRU (minimal coiled-coil repeat unit), that can be inserted in-frame inside the gp26 helical core, preserving the straight morphology of the fiber. Likewise, we were able to remove three quarters of the helical core of the HS1 tail needle, minimally decreasing the stability of the fiber. We conclude that in the gp26 family of tail needles, structural stability increases nonlinearly with the length of the {alpha}-helical core. Thus, the overall stability of these bacteriophage fibers is not solely dependent on the number of trimerization repeats in the {alpha}-helical core.« less

  20. Remote control canard missile with a free-rolling tail brake torque system

    NASA Technical Reports Server (NTRS)

    Blair, A. B., Jr.

    1981-01-01

    An experimental wind-tunnel investigation has been conducted at supersonic Mach numbers to determine the static aerodynamic characteristics of a cruciform canard-controlled missile with fixed and free-rolling tail-fin afterbodies. Mechanical coupling effects of the free-rolling tail afterbody were investigated using an electronic/electromagnetic brake system that provides arbitrary tail-fin brake torques with continuous measurements of tail-to-mainframe torque and tail-roll rate. Results are summarized to show the effects of fixed and free-rolling tail-fin afterbodies that include simulated measured bearing friction torques on the longitudinal and lateral-directional aerodynamic characteristics.

Some links on this page may take you to non-federal websites. Their policies may differ from this site.