WorldWideScience

Sample records for strong bottom water

  1. Strong Flows of Bottom Water in Abyssal Channels of the Atlantic

    Science.gov (United States)

    Morozov, E. G.

    Analysis of bottom water transport through the abyssal channels of the Atlantic Ocean is presented. The study is based on recent observations in the Russian expeditions and historical data. A strong flow of Antarctic Bottom Water from the Argentine Basin to the Brazil Basin through the Vema Channel is observed on the basis of lowered profilers and anchored buoys with current meters. The further flow of bottom water in the Brazil Basin splits in the northern part of the basin. Part of the bottom water flows to the East Atlantic through the Romanche and Chain fracture zones. The other part follows the bottom topography and flows to the northwester into the North American Basin. Part of the northwesterly flow propagates through the Vema Fracture Zone into the Northeastern Atlantic. This flow generally fills the bottom layer in the Northeastern Atlantic basins. The flows of bottom waters through the Romanche and Chain fracture zones do not spread to the Northeast Atlantic due to strong mixing in the equatorial zone and enhanced transformation of bottom water properties.

  2. Bottomonia: open bottom strong decays and spectrum

    Directory of Open Access Journals (Sweden)

    Santopinto E.

    2014-05-01

    Full Text Available We present our results for the bottomonium spectrum with self energy corrections. The bare masses used in the calculation are computed within Godfrey and Isgur’s relativized quark model. We also discuss our results for the open bottom strong decay widths of higher bottomonia in the 3P0 pair-creation model.

  3. Spreading of Antarctic Bottom Water in the Atlantic Ocean

    OpenAIRE

    Morozov, E.; Tarakanov, R. Y.; Zenk, Walter

    2012-01-01

    This paper describes the transport of bottom water from its source region in the Weddell Sea through the abyssal channels of the Atlantic Ocean. The research brings together the recent observations and historical data. A strong flow of Antarctic Bottom Water through the Vema Channel is analyzed. The mean speed of the flow is 30 cm/s. A temperature increase was found in the deep Vema Channel, which has been observed for 30 years already. The flow of bottom water in the northern part of the Bra...

  4. SPREADING OF ANTARCTIC BOTTOM WATER IN THE ATLANTIC OCEAN

    Directory of Open Access Journals (Sweden)

    Eugene Morozov

    2012-01-01

    Full Text Available This paper describes the transport of bottom water from its source region in the Weddell Sea through the abyssal channels of the Atlantic Ocean. The research brings together the recent observations and historical data. A strong flow of Antarctic Bottom Water through the Vema Channel is analyzed. The mean speed of the flow is 30 cm/s. A temperature increase was found in the deep Vema Channel, which has been observed for 30 years already. The flow of bottom water in the northern part of the Brazil Basin splits. Part of the water flows through the Romanche and Chain fracture zones. The other part flows to the North American Basin. Part of the latter flow propagates through the Vema Fracture Zone into the Northeast Atlantic. The properties of bottom water in the Kane Gap and Discovery Gap are also analyzed.

  5. Bottom Backscattering Strengths Measured in Shallow and Deep Water

    Science.gov (United States)

    2017-01-18

    to the MF results. 18-01-2017 Memorandum Report Bottom scattering Bottom scattering strength Reverberation Underwater acoustics Active sonar August...Naval Research Laboratory Washington, DC 20375-5320 NRL/MR/7160--17-9701 Bottom Backscattering Strengths Measured in Shallow and Deep Water January...18, 2017 Approved for public release; distribution is unlimited. RogeR C. gauss edwaRd L. Kunz Joseph M. FiaLKowsKi RiChaRd Menis Acoustic Signal

  6. Bottom Sediment Chemistry, Nutrient Balance, and Water Birds in ...

    African Journals Online (AJOL)

    Water bird characteristics, nutrient loadings, and the levels of bottom sediment silicon oxide (SiO2), aluminium oxide (Al2O3), ferric oxide (Fe2O3), calcium oxide (CaO), copper (Cu), phosphorus (P) and organic carbon (C) was studied in eight high altitude (2040-2640m) small shallow (0.065-0.249 km2; 0.9-3.1 m) ...

  7. Recovery of municipal waste incineration bottom ash and water treatment sludge to water permeable pavement materials.

    Science.gov (United States)

    Lin, Cheng-Fang; Wu, Chung-Hsin; Ho, Hsiu-Mai

    2006-01-01

    Water treatment plant sludge and municipal solid waste incinerator bottom ash are non-hazardous residues, and they can be reprocessed to produce useful materials for city public works. In this study, an effort was endeavored to investigate the properties of water permeable bricks made of water treatment sludge and bottom ash without involving an artificial aggregate step. The water treatment plant sludge was dried and ground, and the bottom ash was subjected to magnetic separation to remove ferrous metals. Both sludge and bottom ash were ground and sieved to a size of bottom ash and the blocks were molded under a pressure of 110 kg/cm2. Thereafter, the molded blocks were sintered at temperatures of 900-1200 degrees C for 60-360 min. The compressive strength, permeability and water absorption rate of the sintered brick were examined and compared to relevant standards. The amount of bottom ash added in the mixture with water treatment sludge affects both the compressive strength and the permeability of the sintered bricks. The two effects are antonymous as higher bottom ash content will develop a beehive configuration and have more voids in the brick. It is concluded that a 20% weight content of bottom ash under a sintering condition of 1150 degrees C for 360 min can generate a brick with a compressive strength of 256 kg/cm2, a water absorption ratio of 2.78% and a permeability of 0.016 cm/s.

  8. An Analysis Model for Water Cone Subsidence in Bottom Water Drive Reservoirs

    Science.gov (United States)

    Wang, Jianjun; Xu, Hui; Wu, Shucheng; Yang, Chao; Kong, lingxiao; Zeng, Baoquan; Xu, Haixia; Qu, Tailai

    2017-12-01

    Water coning in bottom water drive reservoirs, which will result in earlier water breakthrough, rapid increase in water cut and low recovery level, has drawn tremendous attention in petroleum engineering field. As one simple and effective method to inhibit bottom water coning, shut-in coning control is usually preferred in oilfield to control the water cone and furthermore to enhance economic performance. However, most of the water coning researchers just have been done on investigation of the coning behavior as it grows up, the reported studies for water cone subsidence are very scarce. The goal of this work is to present an analytical model for water cone subsidence to analyze the subsidence of water cone when the well shut in. Based on Dupuit critical oil production rate formula, an analytical model is developed to estimate the initial water cone shape at the point of critical drawdown. Then, with the initial water cone shape equation, we propose an analysis model for water cone subsidence in bottom water reservoir reservoirs. Model analysis and several sensitivity studies are conducted. This work presents accurate and fast analytical model to perform the water cone subsidence in bottom water drive reservoirs. To consider the recent interests in development of bottom drive reservoirs, our approach provides a promising technique for better understanding the subsidence of water cone.

  9. Influence of internal tides on Antarctic Bottom Water propagation through abyssal channels

    Science.gov (United States)

    Morozov, Eugene

    2010-05-01

    Antarctic Bottom Water (AABW) propagates in the Atlantic Ocean from the Weddell Sea to the north through narrow passages in submarine ridges. Submarine ridges are regions of strong internal tide generation in the ocean that causes mixing and eventually AABW loses its distinguishing properties such as low temperature and salinity. The Vema Fracture Zone (11 N) and Romanche Fracture Zone (equator) in the Mid-Atlantic Ridge (MAR) are pathways for AABW to the Northeast Atlantic. The deep basin of the Northeast Atlantic (Canary Basin and Gambia Abyssal Plain) are filled with the bottom water propagating through the Vema FZ rather than through the equatorial fracture zones because strong internal tides and mixing over the slopes of the MAR near the equator cause warming of AABW and decrease of its density. Further propagation of AABW through the Kane Gap is low. Recent field measurements in the fracture zones confirm this concept based on modeling results. Results of recent cruises are presented.

  10. Learning the ropes : winning in the international arena takes strong performances on a triple bottom line

    Energy Technology Data Exchange (ETDEWEB)

    Falkenberg, L.

    2000-10-02

    The challenges facing the petroleum industry in terms of their social and environmental responsibilities at an international level were discussed. Compared to a decade ago, today's company must satisfy shareholders of different types, including environmentalists, non-governmental organizations, religious groups, social activists, international charity agencies and the media. These groups have demanded a shift from financial accountability to a triple bottom line which includes the reporting of financial, social and environmental outcomes. In particular, this paper presented an example where Talisman Energy of Calgary started work in civil war raged Sudan and became the target of criticism from the American Secretary of State. Canada's Minister of Foreign Affairs was pressured by interest groups to impose sanctions on Talisman regardless of the constructive development in the local Sudanese community through projects supported by Talisman. Talisman is responding by communicating the real benefits of its involvement in Sudan, including vaccination campaigns, provision of clean water, funding for schools, jobs for local people, and support for human rights monitoring. 1 fig.

  11. Instability of bottom-water redox conditions during accumulation of Quaternary sediment in the Japan Sea

    Science.gov (United States)

    Piper, D.Z.; Isaacs, C.M.

    1996-01-01

    recording sulfate-reducing conditions in bottom water. The forcing function that altered their accumulation, that is, that altered primary productivity and bottom water redox conditions, is problematic. Currently held opinion suggests that O2 depletion was most strongly developed during glacial advances. Low sea level during such times is interpreted to have enhanced primary productivity and restricted bottom-water advection.

  12. Lime application methods, water and bottom soil acidity in fresh water fish ponds

    Directory of Open Access Journals (Sweden)

    Queiroz Julio Ferraz de

    2004-01-01

    Full Text Available Although some methods for determining lime requirement of pond soils are available and commonly used, there is still no consensus on whether it is more effective to apply liming materials to the bottoms of empty ponds or to wait and apply them over the water surface after ponds are filled. There is also little information on how deep lime reacts in pond sediment over time, and whether the depth of reaction is different when liming materials are applied to the water or to the soil. Therefore, three techniques for treating fish ponds with agricultural limestone were evaluated in ponds with clayey soils at a commercial fish farm. Amounts of agricultural limestone equal to the lime requirement of bottom soils were applied to each of three ponds by: direct application over the pond water surface; spread uniformly over the bottom of the empty pond; spread uniformly over the bottom of the empty pond followed by tilling of the bottom. Effectiveness of agricultural limestone applications did not differ among treatment methods. Agricultural limestone also reacted quickly to increase total alkalinity and total hardness of pond water to acceptable concentrations within 2 weeks after application. The reaction of lime to increase soil pH was essentially complete after one to two months, and lime had no effect below a soil depth of 8 cm. Tilling of pond bottoms to incorporate liming materials is unnecessary, and tilling consumes time and is an expensive practice; filled ponds can be limed effectively.

  13. Validation of current acoustic dead-zone estimation methods in lakes with strongly sloped bottoms

    Czech Academy of Sciences Publication Activity Database

    Tušer, Michal; Balk, H.; Mrkvička, T.; Frouzová, Jaroslava; Čech, Martin; Muška, Milan; Kubečka, Jan

    2011-01-01

    Roč. 9, - (2011), s. 507-514 ISSN 1541-5856 R&D Projects: GA ČR(CZ) GA206/07/1392 Grant - others:EEA FM, NFM(CZ) CZ 0091 Institutional research plan: CEZ:AV0Z60170517 Keywords : acoustic dead zone * bottom slope * lentic freshwater habitats Subject RIV: DA - Hydrology ; Limnology Impact factor: 1.535, year: 2011

  14. Mercury in water and bottom sediments from a mexican reservoir

    International Nuclear Information System (INIS)

    Avila Perez, P.; Zarazua Ortega, G.; Barcelo Quintal, D.; Rosas, P.; Diazdelgado, C.

    2001-01-01

    The Lerma-Santiago river's source is located in the State of Mexico. Its drainage basin occupies an area of 129,632 km2. The river receives urban wastewater discharges from 29 municipalities, as well as industrial water discharges, both treated and untreated, mainly from the industrial zones of Toluca, Lerma, Ocoyoacac, Santiago Tianguistengo, Pasteje and Atlacomulco. It is estimated that during a year, the stream receives 536 x 106 m3 of waste waters, which carries 350,946 ton of organic load; 33% of these waste waters come from urban discharges, and 67% originate from industrial discharges. The Jose Antonio Alzate Reservoir fed by the Lerma river is the first significant water reservoir downstream of the main industrial areas in the State of Mexico and both are considered the most contaminated water bodies in the State of Mexico. Mercury concentrations in water and bottom sediments in the Jose Antonio Alzate Reservoir were determined in 6 different sampling zones over a 1-year period. Mercury was measured by instrumental neutron activation analysis (INAA) and irradiated with a thermal neutron flux of 9 x 1012 n. cm-2 s-1 for a period of 26 hours. High variations of mercury concentrations in water in both, soluble and suspended forms, were observed to depend on the sampling season. During the rainy season, rain events contribute with a substantial water volume to modify physicochemical parameters like pH, which dilute chemical species in the Alzate Reservoir. There are evidence that in the Jose Antonio Alzate reservoir, sedimentation and adsorption act as a natural cleaning process, decreasing the dissolved concentrations and increasing the metallic content of the sediments. A negative gradient was identified for mercury concentrations, from the Lerma river inlet to Alzate Reservoir dam, which demonstrates the considerable influence of the Lerma river inlet. This gradient also proves the existence of a metal recycling process between water and sediment, while the

  15. Reshaping the Antarctic Circumpolar Current via Antarctic Bottom Water Export

    Science.gov (United States)

    Stewart, A.; Hogg, A.

    2016-02-01

    Westerly wind forcing of Antarctic Circumpolar Current (ACC) is balanced at large-scale topographic obstructions by form drag; the formation of standing meanders produces a net westward pressure gradient associated with the geostrophically balanced meridional flow. These topographic obstructions also support the northward geostrophic flow of Antarctic Bottom Water (AABW), which piles up dense water on the eastern side of the topography and thereby acts to reduce the form drag. We therefore hypothesize that variations in the density of AABW and its export rate must be accommodated by reshaping the ACC's standing meanders in order to preserve the zonal force balance. We test this hypothesis using an idealized, eddy-resolving sector model of the ACC. We find that response of the ACC to switching off AABW production depends on whether the topography is high enough to block barotropic potential vorticity (PV) contours. If re-entrant PV contours exist then the ACC responds similarly to switching off AABW production or halving the westerly wind strength: for example the ACC transport drops by 10-20% and the surface speed in the meander decreases by around 25%. If PV contours are blocked then the ACC transport becomes insensitive to the westerlies, but switching off AABW production still leads to a reduced ACC transport through a wider, slower meander. These results suggest that the warming and freshening of AABW observed in recent decades may have a detectable impact on the surface circulation of the ACC.

  16. Net-bottom Cage Inserts for Water Bird Casualties

    Directory of Open Access Journals (Sweden)

    Jackie Belle

    2017-10-01

    Full Text Available My Bright Idea is a net-bottomed cage insert, which is used to support pelagic avian casualties. The idea was designed and modified by the International Bird Rescue in California (Bird Rescue.

  17. The occurrence of heavy metals and metal-resistant bacteria in water and bottom sediments of the Straszyn reservoir (Poland

    Directory of Open Access Journals (Sweden)

    Kulbat Eliza

    2017-01-01

    Full Text Available The aim of this study is to investigate the distribution of selected heavy metals and metal–resistant bacteria in water and bottom sediments of the surface drinking water reservoir for Gdańsk. The following sequence of metals in regard to metal concentration in sediments can be written down: Zn > Pb > Cu > Cd. The evaluation of metals accumulation was performed using the Müller index, to indicate the bottom sediment's contamination and geochemical classification of sediment quality according to Polish standards. The Müller geochemical index was changing in a wide range: < 1–4.1. Although the maximum value of Müller's geochemical index determined for copper indicates that the sediment is ‘strongly contaminated’, in general the analysed bottom sediments were classified as the I and II category according to Polish geochemical standards. From the microbiological side a significant part of heterotrophic bacteria isolated from the bottom sediment and surface water (raw and treated water showed a resistance to 0.2 mM and 2 mM concentrations of zinc, copper and lead. The highest percentages of metal–resistant bacteria were recorded in the sediments of the reservoir (60%–88%. The share of metal–resistant strains in the raw water was significantly lower (34%–61%. The results indicate also that water treatment processes may contribute to the selection of resistant strains.

  18. Properties of the Water Column and Bottom Derived from AVIRIS Data

    Science.gov (United States)

    Lee, Zhong-Ping; Carder, Kendall L.; Chen, F. Robert; Peacock, Thomas G.

    2001-01-01

    Using AVIRIS data as an example, we show in this study that the optical properties of the water column and bottom of a large, shallow area can be adequately retrieved using a model-driven optimization technique. The simultaneously derived properties include bottom depth, bottom albedo, and water absorption and backscattering coefficients, which in turn could be used to derive concentrations of chlorophyll, dissolved organic matter, and suspended sediments. The derived bottom depths were compared with a bathymetry chart and a boat survey and were found to agree very well. Also, the derived bottom-albedo image shows clear spatial patterns, with end members consistent with sand and seagrass. The image of absorption and backscattering coefficients indicates that the water is quite horizontally mixed. These results suggest that the model and approach used work very well for the retrieval of sub-surface properties of shallow-water environments even for rather turbid environments like Tampa Bay, Florida.

  19. Studies on the independence of the strong interactions on the flavor quantum numbers with bottom, charm, strange, and light quarks

    International Nuclear Information System (INIS)

    Biebel, O.

    1993-11-01

    A study of possible flavour dependence of the strong interaction is presented using data collected with the OPAL detector at the e + e - collider LEP. Four subsamples of events, highly enriched in bottom, charm, strange and light quarks are obtained from high momentum electrons and muons, D *± mesons, K s 0 mesons, and highly energetic stable charged particles, respectively. From the jet production rates of each of these four samples a strong coupling constant α s f for the dominant quark flavour is derived. The ratios of α s for a specific quark flavour f and its complementary flavours are determined to be α s b /α s udsc =1.017±0.036, α s c /α s udsb =0.918±0.115, α s s /α s udcb =1.158±0.164, α s uds /α s cb =1.038 ± 0.221, where the errors are combinations of statistical and systematic uncertainties. In combining the relevant data samples, a systematic study of possible dependence of the strong interaction on quark mass, weak isospin, and generation is performed. No evidence for any such dependence of the strong coupling constant α s is observed. Finally all samples are combined to determine the strong coupling constant of each flavour individually. Again the results are well consistent with the flavour independence of QCD. (orig.)

  20. Seasonal and inter-annual temperature variability in the bottom waters over the Black Sea shelf

    Science.gov (United States)

    Shapiro, G. I.; Wobus, F.; Aleynik, D. L.

    2011-02-01

    Long-term changes in the state of the Bottom Shelf Water (BSW) on the Western shelf of the Black Sea are assessed using analysis of intra- and inter-annual variations of temperature as well as their relations to physical parameters of both shelf and deep-sea waters. First, large data sets of in-situ observations over the 20th century are compiled into high-resolution monthly climatology at different depth levels. Then, the temperature anomalies from the climatic mean are calculated and aggregated into spatial compartments and seasonal bins to reveal temporal evolution of the BSW. For the purpose of this study the BSW is defined as such shelf water body between the seabed and the upper mixed layer (bounded by the σθ = 14.2 isopycnal) which has limited ability to mix vertically with oxygen-rich surface waters during the warm season (May-November) due to the formation of a seasonal pycnocline. The effects of atmospheric processes at the surface on the BSW are hence suppressed as well as the action of the "biological pump". The vertical extent of the near- bottom waters is determined based on energy considerations and the structure of the seasonal pycnocline, whilst the horizontal extent is controlled by the shelf break, where strong along-slope currents hinder exchanges with the deep sea. The BSW is shown to occupy nearly half of the area of the shelf during the summer stratification period. The potential of the BSW to ventilate horizontally during the warm season with the deep-sea waters is assessed using isopycnic analysis of temperature variations. A long-term time series of temperature anomalies in the BSW is constructed from observations during the May-November period for the 2nd half of the 20th century. The results reveal a warm phase in the 1960s/70s, followed by cooling of the BSW during 1980-2001. The transition between the warm and cold periods coincides with a regime shift in the Black Sea ecosystem. While it was confirmed that the memory of winter

  1. A Study on the Environmental Standard of Sediment on the Bottom of the Water

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Chang Hee; Yoo, Hye Jin [Korea Environment Institute, Seoul (Korea)

    2000-12-01

    Sediment on the bottom of the water has been considered one of the water pollutants in the environmental management of Korea so treated as a management on pollutants, as you can see the examples in the dragging operation in the polluted sea area. To healthily maintain and conserve the water ecosystem including bottom living things in the water, sediment on the bottom of the water should be recognized as the independent medium, which should maintain the certain quality like the water, the atmosphere, and soil, rather than the source of water pollution. Such recognition means that the management of sediment on the bottom of the water should change the fragmentary goal, centered the post management focusing on the water management, to the ecosystematic goal including the bottom living things. In a point of the view, this study has a great significance to suggest not only the final goal for the management of sediment on the bottom of the water but also the necessity of developing the environmental standard of the sediment on the bottom of the water, which is a standard of the management or judgment in the actual managing the sediment on the bottom of the water - an estimation on the pollution of sediment, a removal of the polluted sediment, a purification of sediment, and an abandonment of the dragged sediment -, and the development measures. Considering the situation that even the basic scheme related to the management of sediment is not prepared in the Government level, the concept of the environmental standard of sediment, the foreign example of the environmental standard of sediment, the current state of the domestic sediment pollution, and the development scheme of the environmental standard in this study must be the important foundation to establish the management system of sediment in the Government level. 121 refs., 10 figs., 45 tabs.

  2. Near-bottom water warming in the Laptev Sea in response to atmospheric and sea-ice conditions in 2007

    Directory of Open Access Journals (Sweden)

    Jens A. Hölemann

    2011-05-01

    Full Text Available In this paper we present new data from ship-based measurements and two-year observations from moorings in the Laptev Sea along with Russian historical data. The observations from the Laptev Sea in 2007 indicate that the bottom water temperatures on the mid-shelf increased by more than 3°C compared to the long-term mean as a consequence of the unusually high summertime surface water temperatures. Such a distinct increase in near-bottom temperatures has not been observed before. Remnants of the relatively warm bottom water occupied the mid-shelf from September 2007 until April 2008. Strong polynya activity during March to May 2007 caused more summertime open water and therefore warmer sea surface temperatures in the Laptev Sea. During the ice-free period in August and September 2007, the prevailing cyclonic atmospheric circulation deflected the freshwater plume of the River Lena to the east, which increased the salinity on the mid-shelf north of the Lena Delta. The resulting weaker density stratification allowed more vertical mixing of the water column during storms in late September and early October, leading to the observed warming of the near-bottom layer in the still ice-free Laptev Sea. In summer and autumn 2008, when the density stratification was stronger and sea surface temperatures were close to the long-term mean, no near-bottom water warming was observed. Warmer water temperatures near the seabed may also impact the stability of the shelf's submarine permafrost.

  3. Classification of bottom composition and bathymetry of shallow waters by passive remote sensing

    Science.gov (United States)

    Spitzer, D.; Dirks, R. W. J.

    The use of remote sensing data in the development of algorithms to remove the influence of the watercolumn on upwelling optical signals when mapping the bottom depth and composition in shallow waters. Calculations relating the reflectance spectra to the parameters of the watercolumn and the diverse bottom types are performed and measurements of the underwater reflection coefficient of sandy, mud, and vegetation-type seabottoms are taken. The two-flow radiative transfer model is used. Reflectances within the spectral bands of the Landsat MSS, the Landsat TM, SPOT HVR, and the TIROS-N series AVHRR were computed in order to develop appropriate algorithms suitable for the bottom depth and type mapping. Bottom depth and features appear to be observable down to 3-20 m depending on the water composition and bottom type.

  4. Bottom depth and type for shallow waters: Hyperspectral observations from a blimp

    Energy Technology Data Exchange (ETDEWEB)

    Lee, ZhongPing; Carder, K.; Steward, R. [Univ. of South Florida, St. Petersburg, FL (United States)] [and others

    1997-08-01

    In a study of a blimp transect over Tampa Bay (Florida), hyperspectral upwelling radiance over the sand and seagrass bottoms was measured. These measurements were converted to hyperspectral remote-sensing reflectances. Using a shallow-water remote-sensing-reflectance model, in-water optical properties, bottom depths and bottom albedos were derived analytically and simultaneously by an optimization procedure. In the process, curvatures of sand and seagrass albedos were used. Also used was a model of absorption spectrum of phytoplankton pigments. The derived bottom depths were compared with bathymetry charts and found to agree well. This study suggests that a low-flying blimp is a useful platform for the study and mapping of coastal water environments. The optical model as well as the data-reduction procedure used are practical for the retrieval of shallow water optical properties.

  5. Influence of Ross Sea Bottom Water changes on the warming and freshening of the Antarctic Bottom Water in the Australian-Antarctic Basin

    Directory of Open Access Journals (Sweden)

    K. Shimada

    2012-07-01

    Full Text Available Changes to the properties of Antarctic Bottom Water in the Australian-Antarctic Basin (AA-AABW between the 1990s and 2000s are documented using data from the WOCE Hydrographic Program (WHP and repeated hydrographic surveys. Strong cooling and freshening are observed on isopycnal layers denser than γn = 28.30 kg m−3. Changes in the average salinity and potential temperature below this isopycnal correspond to a basin-wide warming of 1300 ± 200 GW and freshening of 24 ± 3 Gt year−1. Recent changes to dense shelf water in the source regions in the Ross Sea and George V Land can explain the freshening of AA-AABW but not its extensive warming. An alternative mechanism for this warming is a decrease in the supply of AABW from the Ross Sea (RSBW. Hydrographic profiles between the western Ross Sea and George V Land (171–158° E were analyzed with a simple advective-diffusive model to assess the causes of the observed changes. The model suggests that the warming of RSBW observed between the 1970s and 2000s can be explained by a 21 ± 23% reduction in RSBW transport and the enhancement of the vertical diffusion of heat resulting from a 30 ± 7% weakening of the abyssal stratification. The documented freshening of Ross Sea dense shelf water leads to a reduction in both salinity and density stratification. Therefore the direct freshening of RSBW at its source also produces an indirect warming of the RSBW. A simple box model suggests that the changes in RSBW properties and volume transport (a decrease of 6.7% is assumed between the year 1995 and 2005 can explain 51 ± 6% of the warming and 84 ± 10% of the freshening observed in AA-AABW.

  6. Treated bottom ash medium and method of arsenic removal from drinking water

    Science.gov (United States)

    Gadgil, Ashok

    2009-06-09

    A method for low-cost arsenic removal from drinking water using chemically prepared bottom ash pre-treated with ferrous sulfate and then sodium hydroxide. Deposits on the surface of particles of bottom ash form of activated iron adsorbent with a high affinity for arsenic. In laboratory tests, a miniscule 5 grams of pre-treated bottom ash was sufficient to remove the arsenic from 2 liters of 2400 ppb (parts per billion) arsenic-laden water to a level below 50 ppb (the present United States Environmental Protection Agency limit). By increasing the amount of pre-treated bottom ash, even lower levels of post-treatment arsenic are expected. It is further expected that this invention supplies a very low-cost solution to arsenic poisoning for large population segments.

  7. Relaxing the formation of hypoxic bottom water with sediment microbial fuel cells.

    Science.gov (United States)

    Touch, Narong; Hibino, Tadashi; Morimoto, Yuki; Kinjo, Nobutaka

    2017-12-01

    The method of improving bottom water environment using industrial wastes to suppress diffusion substances from bottom sediment has recently captured the attention of many researchers. In this study, wastewater discharge-derived sediment was used to examine an alternative approach involving the use of sediment microbial fuel cells (SMFCs) in relaxing the formation of hypoxic bottom water, and removing reduced substances from sediment. Concentrations of dissolved oxygen (DO) and other ions were measured in overlying water and sediment pore water with and without the application of SMFCs. The results suggest that SMFCs can markedly reduce hydrogen sulfide and manganese ion concentrations in overlying water, and decrease the depletions of redox potential and DO concentration. In addition, SMFCs can dissolve ferric compounds in the sediment and thereby release the ferric ion available to fix phosphate in the sediment. Our results indicate that SMFCs can be used as an alternative method to relax the formation of hypoxic bottom water and to remove reduced substances from the sediment, thus improving the quality of both water and sediment environments.

  8. Uranium isotopes in waters and bottom sediments of rivers and lakes in Poland

    International Nuclear Information System (INIS)

    Pietrzak-Flis, Z.; Kaminska, I.; Chrzanowski, E.

    2004-01-01

    Activity concentrations of 238 U, 234 U and 235 U were determined in waters and bottom sediments in two main rivers in Poland (the Vistula and Odra rivers) with their tributaries, in four coastal rivers and six lakes. Concentration of 238 U and 233 U were compared with the concentrations of 226 Ra determined in another study. As compared with concentrations in coastal rivers and in lakes, enhanced concentrations of the radionuclides were observed in water and bottom sediments in the upper and middle courses of Vistula river, whereas in the Odra river the enhanced concentrations were present only in the bottom sediments. The enhanced concentrations in the Vistula river result from the discharge of coal mine waters from the Upper Silesian Coal Basin, and they indicate that the discharge was continued. The enhanced concentration in Odra river observed only in bottom sediments indicate that the discharge occurred in the past. The 234 U/ 238 U ratio for the bottom sediments was close to unity, indicating that these isotopes were close to equilibrium, whereas for water the average ratio was form 1.2 for lakes to 1.5 for the Vistula river, demonstrating the lack of equilibrium. (author)

  9. Numerical simulation of water flow through the bottom en piece of a nuclear fuel assembly

    International Nuclear Information System (INIS)

    Navarro, Moyses A.; Santos, Andre A. Campagnole dos

    2007-01-01

    The water flow through the bottom nozzle of a nuclear fuel assembly was simulated using a commercial CFD code, CFX 10.0. Previously, simulations with a perforated plate similar to the bottom nozzle plate were performed to define the appropriate mesh refinement and turbulence model (κ-ε or SST). Subsequently, the numerical simulation was performed with the optimized mesh using the turbulence model (κ-ε in a standard bottom nozzle with some geometric simplifications. The numerical results were compared with experimental results to determine the pressure drop through the bottom nozzle in the Reynolds range from ∼10500 to ∼95000. The agreement between the numerical simulations and experimental results may be considered satisfactory. The study indicated that the CFD codes can play an important role in the development of pieces with complex geometries, optimizing the planning of the experiments and aiding in the experimental analysis. (author)

  10. a New Technique Based on Mini-Uas for Estimating Water and Bottom Radiance Contributions in Optically Shallow Waters

    Science.gov (United States)

    Montes-Hugo, M. A.; Barrado, C.; Pastor, E.

    2015-08-01

    The mapping of nearshore bathymetry based on spaceborne radiometers is commonly used for QC ocean colour products in littoral waters. However, the accuracy of these estimates is relatively poor with respect to those derived from Lidar systems due in part to the large uncertainties of bottom depth retrievals caused by changes on bottom reflectivity. Here, we present a method based on mini unmanned aerial vehicles (UAS) images for discriminating bottom-reflected and water radiance components by taking advantage of shadows created by different structures sitting on the bottom boundary. Aerial surveys were done with a drone Draganfly X4P during October 1 2013 in optically shallow waters of the Saint Lawrence Estuary, and during low tide. Colour images with a spatial resolution of 3 mm were obtained with an Olympus EPM-1 camera at 10 m height. Preliminary results showed an increase of the relative difference between bright and dark pixels (dP) toward the red wavelengths of the camera's receiver. This is suggesting that dP values can be potentially used as a quantitative proxy of bottom reflectivity after removing artefacts related to Fresnel reflection and bottom adjacency effects.

  11. Shallow water bathymetry correction using sea bottom classification with multispectral satellite imagery

    Science.gov (United States)

    Kazama, Yoriko; Yamamoto, Tomonori

    2017-10-01

    Bathymetry at shallow water especially shallower than 15m is an important area for environmental monitoring and national defense. Because the depth of shallow water is changeable by the sediment deposition and the ocean waves, the periodic monitoring at shoe area is needed. Utilization of satellite images are well matched for widely and repeatedly monitoring at sea area. Sea bottom terrain model using by remote sensing data have been developed and these methods based on the radiative transfer model of the sun irradiance which is affected by the atmosphere, water, and sea bottom. We adopted that general method of the sea depth extraction to the satellite imagery, WorldView-2; which has very fine spatial resolution (50cm/pix) and eight bands at visible to near-infrared wavelengths. From high-spatial resolution satellite images, there is possibility to know the coral reefs and the rock area's detail terrain model which offers important information for the amphibious landing. In addition, the WorldView-2 satellite sensor has the band at near the ultraviolet wavelength that is transmitted through the water. On the other hand, the previous study showed that the estimation error by the satellite imagery was related to the sea bottom materials such as sand, coral reef, sea alga, and rocks. Therefore, in this study, we focused on sea bottom materials, and tried to improve the depth estimation accuracy. First, we classified the sea bottom materials by the SVM method, which used the depth data acquired by multi-beam sonar as supervised data. Then correction values in the depth estimation equation were calculated applying the classification results. As a result, the classification accuracy of sea bottom materials was 93%, and the depth estimation error using the correction by the classification result was within 1.2m.

  12. Transport of Antarctic bottom water through the Kane Gap, tropical NE Atlantic Ocean

    NARCIS (Netherlands)

    Morozov, E.G.; Tarakanov, R.Y.; van Haren, H.

    2013-01-01

    We study low-frequency properties of the Antarctic Bottom Water (AABW) flow through the Kane Gap (9° N) in the Atlantic Ocean. The measurements in the Kane Gap include five visits with CTD (Conductivity-Temperature-Depth) sections in 2009–2012 and a year-long record of currents on a mooring using

  13. Chemical quality of water and bottom sediment, Stillwater National Wildlife Refuge, Lahontan Valley, Nevada

    Science.gov (United States)

    Thodal, Carl E.

    2017-12-28

    The U.S. Geological Survey, in cooperation with the U.S. Fish and Wildlife Service collected data on water and bottom-sediment chemistry to be used to evaluate a new water rights acquisition program designed to enhance wetland habitat in Stillwater National Wildlife Refuge and in Lahontan Valley, Churchill County, Nevada. The area supports habitat critical to the feeding and resting of migratory birds travelling the Pacific Flyway. Information about how water rights acquisitions may affect the quality of water delivered to the wetlands is needed by stakeholders and Stillwater National Wildlife Refuge managers in order to evaluate the effectiveness of this approach to wetlands management. A network of six sites on waterways that deliver the majority of water to Refuge wetlands was established to monitor the quality of streamflow and bottom sediment. Each site was visited every 4 to 6 weeks and selected water-quality field parameters were measured when flowing water was present. Water samples were collected at varying frequencies and analyzed for major ions, silica, and organic carbon, and for selected species of nitrogen and phosphorus, trace elements, pharmaceuticals, and other trace organic compounds. Bottom-sediment samples were collected for analysis of selected trace elements.Dissolved-solids concentrations exceeded the recommended criterion for protection of aquatic life (500 milligrams per liter) in 33 of 62 filtered water samples. The maximum arsenic criterion (340 micrograms per liter) was exceeded twice and the continuous criterion was exceeded seven times. Criteria protecting aquatic life from continuous exposure to aluminum, cadmium, lead, and mercury (87, 0.72, 2.5, and 0.77 micrograms per liter, respectively) were exceeded only once in filtered samples (27, 40, 32, and 36 samples, respectively). Mercury was the only trace element analyzed in bottom-sediment samples to exceed the published probable effect concentration (1,060 micrograms per kilogram).

  14. Reconstructing bottom water temperatures from measurements of temperature and thermal diffusivity in marine sediments

    Science.gov (United States)

    Miesner, F.; Lechleiter, A.; Müller, C.

    2015-07-01

    Continuous monitoring of oceanic bottom water temperatures is a complicated task, even in relatively easy-to-access basins like the North or Baltic seas. Here, a method to determine annual bottom water temperature variations from inverse modeling of instantaneous measurements of temperatures and sediment thermal properties is presented. This concept is similar to climate reconstructions over several thousand years from deep borehole data. However, in contrast, the presented method aims at reconstructing the recent temperature history of the last year from sediment thermal properties and temperatures from only a few meters depth. For solving the heat equation, a commonly used forward model is introduced and analyzed: knowing the bottom water temperature variations for the preceding years and the thermal properties of the sediments, the forward model determines the sediment temperature field. The bottom water temperature variation is modeled as an annual cosine defined by the mean temperature, the amplitude and a phase shift. As the forward model operator is non-linear but low-dimensional, common inversion schemes such as the Newton algorithm can be utilized. The algorithms are tested for artificial data with different noise levels and for two measured data sets: from the North Sea and from the Davis Strait. Both algorithms used show stable and satisfying results with reconstruction errors in the same magnitude as the initial data error. In particular, the artificial data sets are reproduced with accuracy within the bounds of the artificial noise level. Furthermore, the results for the measured North Sea data show small variances and resemble the bottom water temperature variations recorded from a nearby monitoring site with relative errors smaller than 1 % in all parameters.

  15. Valorization of MSWI bottom ash for biogas desulfurization: Influence of biogas water content.

    Science.gov (United States)

    Fontseré Obis, Marta; Germain, Patrick; Troesch, Olivier; Spillemaecker, Michel; Benbelkacem, Hassen

    2017-02-01

    In this study an alternative valorization of Municipal Solid Waste Incineration (MSWI) Bottom Ash (BA) for H 2 S elimination from landfill biogas was evaluated. Emphasis was given to the influence of water content in biogas on H 2 S removal efficiency by BA. A small-scale pilot was developed and implemented in a landfill site located in France. A new biogas analyzer was used and allowed real-time continuous measurement of CH 4 , CO 2 , O 2 , H 2 S and H 2 O in raw and treated biogas. The H 2 S removal efficiency of bottom ash was evaluated for different inlet biogas humidities: from 4 to 24g water /m 3 . The biogas water content was found to greatly affect bottom ash efficiency regarding H 2 S removal. With humid inlet biogas the H 2 S removal was almost 3 times higher than with a dry inlet biogas. Best removal capacity obtained was 56gH 2 S/kgdryBA. A humid inlet biogas allows to conserve the bottom ash moisture content for a maximum H 2 S retention. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. Bottom-Water Oxygenation in the Central Gulf of California for the Last 16 kyrs

    Science.gov (United States)

    Karlin, R. E.; Harris, A.

    2006-12-01

    Laminated sediment records from the central Gulf of California reveal changes in oxygen-related microfabric, which can be directly related to variations in the intensity and location of the oxygen-minimum zone (OMZ) for the last 16,000 years. The intensity and location of the OMZ depends on the interaction of primary productivity and bottom water oxygen availability created by compositional variations and replenishment speed of Pacific Intermediate Water (PIW). Seven cores recovered from water depths ranging from 525 to 820 meters directly sample changes in the extent of the OMZ and PIW. Chronologies for six Atlantis II cores are based on independent radiocarbon ages, stratigraphic correlation, oxygen-isotope stratigraphy, and lamina counts from x-radiograph images. At DSDP Site 480, the varve chronology, when compared to an independent age model based on radiocarbon ages and secular variation curves, indicates that the Site 480 record is continuous and has an age error comparable to that of ice core and tree ring records. Bottom-water oxygenation was relatively higher from 17 to ~15.5 cal kyrs BP and ~12.3 to ~11.9 cal kyrs BP, was lower from ~15.5 to ~12.3 cal kyrs BP and ~11.6 to 7 cal kyrs and began increasing again after 7 cal kyrs. Changes in microfabric and, hence, bottom water oxygenation were not synchronous in the central Gulf. The change from oxic to more anoxic conditions near the end of the last glacial and the Younger Dryas began at depth and progressively shallowed with time. The transition to more oxic conditions in the Younger Dryas also began at depth and shallowed with time. The relationships between proxies for PIW oxygenation, primary productivity, and sediment flux suggest that productivity controlled bottom-water oxygenation from 17 to 11.6 cal kyrs BP. Lower oxygen availability due to less PIW input appears to have controlled bottom-water oxygenation from 11.6 to ~10 cal kyrs BP. No clear basin-wide relationship is found between productivity

  17. BOTTOM SEDIMENTS IN DELTAIC SHALLOW-WATER AREAS – ARE THEY SOILS?

    Directory of Open Access Journals (Sweden)

    Anna N. Tkachenko

    2016-01-01

    Full Text Available This article is based on long-term research of aquatic landscapes in the VolgaRiver delta which was held in 2010–2012 and included investigation and sampling of bottom sediments in deltaic lagoons, fresh-water bays, small channels, oxbow lakes, and part of the deltaic near-shore zone. Contrasting hydrological regime and suspended matter deposition together with huge amount of water plants in the river delta provide for the formation of different types of subaquatic soils. The purpose of this research is to reveal the properties of the subaquatic soils in the Volga River deltaic area and to propose pedogenetic approaches to the diagnostic of aquazems as soil types. It is suggested to name the horizons in aquazems in the same way as in terrestrial soils in the recent Russian soil classification system, and apply symbols starting with the combination of caps – AQ (for “aquatic”. The aquazems’ horizons are identified and their general properties are described. Most typical of aquazems is the aquagley (AQG horizon; it is dove grey, homogeneous in color and permeated by clay. The upper part is usually enriched in organic matter and may be qualified for aquahumus (AQA or  aquapeat (AQT horizons. In case of active hydrodynamic regime and/or strong mixing phenomena, the oxidized (AQOX or aqox horizon, or property could be formed. It is yellowish-grey, thin, and depleted of organic matter. The main types of aquzems specified by forming agents and combinations of horizons are described.

  18. The bottom water exchange between the Singapore Strait and the West Johor Strait

    Science.gov (United States)

    Sun, Yunfang; Eltahir, Elfatih; Malanotte-Rizzoli, Paola

    2017-08-01

    As a part of the border between Singapore and Malaysia, the West Johor Strait (WJS) suffered newly from harmful algal blooms. There is no previous study showing the source of the nutrients in the WJS. This paper is investigating the possible water exchange between the water in the WJS and the bottom water in Singapore Strait. This paper adopts a two-level nesting atmosphere-ocean coupled models to downscale the global atmosphere-ocean model into the Singapore coastal water, keeping the large-scale and long-term ocean and climate circulation signals and the advantages of the high-resolution. Based on the high-resolution ocean circulation fields, a Lagrangian particle tracking model is used to trace the Singapore Strait's bottom water movement and the water mixing in the WJS. The results showed that the numerical models well resolved the Singapore coastal water regional circulation. There is a small but significant bottom water (1.25%) transport from the Singapore Strait to the WJS, which occurs from the southwest coastline of Singapore. The bottom water in the Singapore Strait prefers to enter the WJS during the spring tide and the flood period, and stay in Johor Strait for 6.4 days. The spring tide is the first-order factor for the water vertical mixing in the WJS, the wind is also very important for the vertical mixing especially in neap tide condition. An overall very important factor is the light perturbation. With the strongest vertical mixing of nutrients and bottom sediments due to the spring tide, the latter ones may inhibit the light penetration during the spring tide and reduce the algal bloom. The light penetration otherwise is greater during the neap tide, when the winds are the most important factor and hence favor the algal bloom. With the strongest wind in February and the longest permanence time in June and the sufficient nutrient supply in February and June, the most serious algal blooms may happen in February and June in the WJS.

  19. MONITORING OF PHOSPHORUS CONTENT IN “WATER-PARTICULATE MATERIALS-BOTTOM SEDIMENTS SYSTEM” FOR RIVER PRUT

    Directory of Open Access Journals (Sweden)

    VASILE RUSU

    2011-03-01

    Full Text Available Monitoring of phosphorus content in “water-particulatematerials-bottom sediments system” for river Prut. Seasonal and spatialdynamics of phosphorus forms in water, particulate materials and bottomsediments of river Prut was elucidated. The scheme for determination ofphosphorus forms in water and particulate materials according to World HealthOrganization classification was evaluated. Additionally, this scheme was tested forestimation of phosphorus content in bottom sediments. The supplemented schemeallows the analysis of the phosphorus forms for the entirely system “water –particulate materials – bottom sediments”, extending possibilities for interpretationof phosphorus dynamics in natural waters.

  20. Topological helical edge states in water waves over a topographical bottom

    KAUST Repository

    Wu, Shi qiao

    2017-11-27

    We present the discovery of topologically protected helical edge states in water wave systems, which are realized in water wave propagating over a topographical bottom whose height is modulated periodically in a two-dimensional triangular pattern. We develop an effective Hamiltonian to characterize the dispersion relation and use spin Chern numbers to classify the topology. Through full wave simulations we unambiguously demonstrate the robustness of the helical edge states which are immune to defects and disorders so that the backscattering loss is significantly reduced. A spin splitter is designed for water wave systems, where helical edge states with different spin orientations are spatially separated with each other, and potential applications are discussed.

  1. Impact of bottom trawling on sediment characteristics - A study along inshore waters off Veraval coast, India

    Digital Repository Service at National Institute of Oceanography (India)

    Bhagirathan, U.; Meenakumari, B.; Jayalakshmy, K.V.; Panda, S.K.; Madhu, V.R.; Vaghela, D.T.

    . Madhu · D. T. Vaghela Received: 27 June 2008 / Accepted: 20 November 2008 / Published online: 18 December 2008 © Springer Science + Business Media B.V. 2008 Abstract The present communication is a study on the impact of bottom trawling on the sediment... environment. This variation with water depth is agreeing with the result of study con- ducted by Jayaraj (2006) along northwest Indian shelf. In this study, the organic matter content increased towards shallower depth from deeper regions. Trawling can reduce...

  2. Numerical simulation of water flow through the bottom end piece of a nuclear fuel assembly

    International Nuclear Information System (INIS)

    Navarro, Moyses Alberto; Santos, Andre A.C. dos

    2007-01-01

    An experimental and numerical study was conducted on the pressure loss of flows through the bottom end piece of a nuclear fuel assembly. To determine an optimized numerical methodology using the commercial CFD code, CFX 10.0, a series of preliminary simulations of water flows through perforated plates in a square ducts were performed. A perforated plate is a predominant geometry of the bottom end piece, responsible for the majority of the flow's pressure drop. The numerical pressure loss applying an optimized mesh and the k-ε turbulence model showed good agreement when compared with a conventional methodology (Idelchik). Numerical results for the standard bottom end piece were obtained applying the previously determined mesh criteria and the k-ε turbulence model with some geometric simplifications. The agreement between the numerical simulations and experimental results can be considered satisfactory but suggest further numerical investigations with the bottom piece under real conditions of the experiment, without the geometric simplifications and with a gap between the piece and the wall of the flow channel. Additionally, other turbulence models should be appraised for this complex geometry. (author)

  3. Numerical Simulation of Water Flow through the Bottom End Piece of a Nuclear Fuel Assembly

    Science.gov (United States)

    Navarro, Moysés A.; Santos, André A. C. Dos

    An experimental and numerical study was conducted on the pressure loss of flows through the bottom end piece of a nuclear fuel assembly. To determine an optimized numerical methodology using the commercial CFD code, CFX 10.0, a series of preliminary simulations of water flows through perforated plates in a square ducts were performed. A perforated plate is a predominant geometry of the bottom end piece, responsible for the majority of the flow's pressure drop. The numerical pressure loss applying an optimized mesh and the k-ɛ turbulence model showed good agreement when compared with a conventional methodology (Idelchik). Numerical results for the standard bottom end piece were obtained applying the previously determined mesh criteria and the k-ɛ turbulence model with some geometric simplifications. The agreement between the numerical simulations and experimental results can be considered satisfactory but suggests further numerical investigations with the bottom piece under real conditions of the experiment, without the geometric simplifications and with a gap between the piece and the wall of the flow channel. Additionally, other turbulence models should be appraised for this complex geometry.

  4. The role of the complete Coriolis force in cross-equatorial transport of the Antarctic Bottom Water

    Science.gov (United States)

    Stewart, Andrew; Dellar, Paul

    2010-05-01

    has sign opposite to that of the Coriolis parameter f is subject to symmetric instability, and measurements confirm that the potential vorticity is indeed close to zero near the equator. The solution reveals that the transport of fluid through the channel is strongly affected by the non-traditional component of the Coriolis force. The geometry of the channel and the position of the current are also found to have a substantial effect on the solution. The combination of non-traditional effects with the bathymetry of the channel through which the Antarctic Bottom Water flows can increase the cross-equatorial transport by 50% or more, for realistic parameters. To determine how realistic equatorial topography might influence the transport of the Antarctic Bottom Water, we conduct large-scale numerical simulations of the two-layer shallow water equations, including the complete Coriolis force. The flow into the basin is prescribed at the southern boundary, and the time-dependent shallow water equations are integrated to a quasi-steady state. We discuss some of the computational complications associated with the additional Coriolis terms, and we compare the transports predicted by the traditional and non-traditional equations.

  5. Rainy Periods and Bottom Water Stagnation Initiating Brine Accumulation and Metal Concentrations: 1. The Late Quaternary

    Science.gov (United States)

    Rossignol-Strick, Martine

    1987-06-01

    A working hypothesis is proposed to account for the present accumulation of brines in isolated pockets of the ocean floor and for the formation of the underlying organic and metal-rich sediments. These are the Tyro and Bannock basins in the East Mediterranean, the Red Sea Deeps, and the Orca Basin in the northern Gulf of Mexico. Initiation of brine-derived deposition in the Red Sea Deeps and Orca Basin occurred between 12,000 and 8000 years B.P. This time bracket also encompasses the formation of the latest East Mediterranean sapropel and the wettest global climate since the last glacial maximum. This wet period first appeared in the tropics around 12,000 years B.P, then in the subtropical and middle latitudes. During the same period, the 23,000 year precession cycle brought the summer insolation of the northern hemisphere to its peak at 11,000 years B.P. with retreating northern hemisphere ice sheets. The Red Sea Deeps and the Orca Basin became anoxic during this humid period, and metal-rich sapropel deposition then began. In contrast, the Tyro and Bannock basins began accumulating a brine long before and persisted beyond this climatic stage. The hypothesis involves two propositions: (1) As in the Eastern Mediterranean Sea, marine anoxia was mainly the consequence of the large influx of continental runoff and local precipitation. Longer residence time of bottom waters, so-called "stagnation," in silled rimmed basins would have resulted from lower salinity at the sea surface in areas of deep water formation in the Eastern Mediterranean, the Red Sea, and the Gulf of Mexico and (2) Miocene or older evaporites underlie these basins or outcrop on their flanks. Leaching from these evaporites was an ongoing process before the quasi-stagnation phase, but the initial leachate, much less saline than the present brines, was continuously flushed by bottom circulation. The climate-induced quiescence of bottom waters in these basins enabled the leachate to accumulate. The

  6. Occurrence and distribution of perfluoroalkyl substances (PFASs) in surface water and bottom water of the Shuangtaizi Estuary, China.

    Science.gov (United States)

    Shao, Mihua; Ding, Guanghui; Zhang, Jing; Wei, Lie; Xue, Huanhuan; Zhang, Nannan; Li, Yang; Chen, Guanqun; Sun, Yeqing

    2016-09-01

    Perfluoroalkyl substances (PFASs) have been recognized as emerging environmental pollutants. However, there is limited information on the contamination level and spatial distribution of PFASs in the Shuangtaizi Estuary, where the Shuangtaizi Hekou Nature Reserve is located. In the present study, the contamination level and spatial distribution of PFASs in surface water (approximately 0.5 m below the surface) and bottom water (about 0.5 m above the bottom) of the Shuangtaizi Estuary were investigated. The data indicated that the Shuangtaizi Estuary was commonly contaminated by PFASs. The total concentration of PFASs in surface and bottom water of the Shuangtaizi Estuary ranged from 66.2 to 185 ng L(-1) and from 44.8 to 209 ng L(-1), respectively. The predominant PFASs were perfluorobutanoic acid (PFBA), perfluoropentanoic acid, perfluorooctanoic acid, perfluorohexanoic acid and perfluorobutane sulfonate (PFBS). In general, PFAS concentrations in surface water samples were lower than those in bottom water samples. The spatial distribution of PFASs in the Shuangtaizi Estuary was mainly affected by particular landform, tide and residual currents in Liaodong Bay. The total mass flux of 15 PFASs from the Shuangtaizi River to Liaodong Bay was estimated to be 352 kg year(-1), which was lower than the total flux from the Daling River and the Daliao River. As short-chain PFASs, such as PFBS and PFBA, have been the prevalent compounds in some places and are continuously produced and used, long-term monitoring and effective pollution controls are suggested. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. Accelerated freshening of Antarctic Bottom Water over the last decade in the Southern Indian Ocean.

    Science.gov (United States)

    Menezes, Viviane V; Macdonald, Alison M; Schatzman, Courtney

    2017-01-01

    Southern Ocean abyssal waters, in contact with the atmosphere at their formation sites around Antarctica, not only bring signals of a changing climate with them as they move around the globe but also contribute to that change through heat uptake and sea level rise. A repeat hydrographic line in the Indian sector of the Southern Ocean, occupied three times in the last two decades (1994, 2007, and, most recently, 2016), reveals that Antarctic Bottom Water (AABW) continues to become fresher (0.004 ± 0.001 kg/g decade -1 ), warmer (0.06° ± 0.01°C decade -1 ), and less dense (0.011 ± 0.002 kg/m 3 decade -1 ). The most recent observations in the Australian-Antarctic Basin show a particularly striking acceleration in AABW freshening between 2007 and 2016 (0.008 ± 0.001 kg/g decade -1 ) compared to the 0.002 ± 0.001 kg/g decade -1 seen between 1994 and 2007. Freshening is, in part, responsible for an overall shift of the mean temperature-salinity curve toward lower densities. The marked freshening may be linked to an abrupt iceberg-glacier collision and calving event that occurred in 2010 on the George V/Adélie Land Coast, the main source region of bottom waters for the Australian-Antarctic Basin. Because AABW is a key component of the global overturning circulation, the persistent decrease in bottom water density and the associated increase in steric height that result from continued warming and freshening have important consequences beyond the Southern Indian Ocean.

  8. The nepheloid bottom layer and water masses at the shelf break of the western Ross Sea

    Science.gov (United States)

    Capello, Marco; Budillon, Giorgio; Cutroneo, Laura; Tucci, Sergio

    2009-06-01

    In the austral summers of 2000/2001 and 2002/2003 the Italian CLIMA Project carried out two oceanographic cruises along the northwestern margin of the Ross Sea, where the Antarctic Bottom Water forms. Here there is an interaction between the water masses on the sea floor of the outer shelf and slope with a consequent evolution of benthic nepheloid layers and an increase in total particulate matter. We observed three different situations: (a) the presence of triads (bottom structures characterized by a concomitant jump in turbidity, temperature, and salinity data) and high re-suspension phenomena related to the presence of the Circumpolar Deep Water and its mixing with cold, salty shelf waters associated with gravity currents; (b) the absence of triads with high re-suspension, implying that when the gravity currents are no longer active the benthic nepheloid layer may persist until the suspended particles settle to the sea floor, suggesting that the turbidity data can be used to study recent gravity current events; and (c) the absence of turbidity and sediment re-suspension phenomena supports the theory that a steady situation had been re-established and the current interaction no longer occurred or had finished sometime before.

  9. Impacts of Bottom Trawling and Litter on the Seabed in Norwegian Waters

    Directory of Open Access Journals (Sweden)

    Pål Buhl-Mortensen

    2018-02-01

    Full Text Available Bottom trawling and seabed littering are two serious threats to seabed integrity. We present an overview of the distribution of seabed litter and bottom trawling in Norwegian waters (the Norwegian Sea and the southern Barents Sea. Vessel Monitoring System (VMS records and trawl marks (TM on the seabed were used as indicators of pressure and impact of bottom trawling, respectively. Estimates of TM density and litter abundance were based on analyses of seabed videos from 1,778 locations, surveyed during 23 cruises, part of the Norwegian seabed mapping programme MAREANO. The abundance and composition of litter and the density of TM varied with depth, and type of sediments and marine landscapes. Lost or discarded fishing gear (especially lines and nets, and plastics (soft and hard plastic and rubber were the dominant types of litter. The distribution of litter reflected the distribution of fishing intensity (density of VMS records and density of TM at a regional scale, with highest abundance close to the coast and in areas with high fishing intensity, indicated from the VMS data. However, at a local scale patterns were less clear. An explanation to this could be that litter is transported with currents and accumulates in troughs, canyons, and local depressions, rather than reflecting the fisheries footprints directly. Also, deliberate dumping of discarded fishing gear is likely to occur away from good fishing grounds. Extreme abundance of litter, observed close to the coast is probably caused by such discarded fishing gear, but the contribution from aggregated populations on land is also indicated from the types of litter observed. The density of trawl marks is a good indicator of physical impact in soft sediments where the trawl gear leaves clear traces, whereas on harder substrates the impacts on organisms is probably greater than indicated by the hardly visible marks. The effects of litter on benthic communities is poorly known, but large litter

  10. Importance of different types of marine particles for the scavenging of heavy metals in the deep-sea bottom water

    International Nuclear Information System (INIS)

    Koschinsky, A.; Winkler, A.; Fritsche, U.

    2003-01-01

    In experiments of 7 days duration using voltammetric and radiotracer measurement techniques, the role of different particle types in the sorption of dissolved metal species in a disturbed deep-sea bottom seawater system were investigated. Resuspension of oxic to suboxic surface sediment into the bottom water in the deep sea (either by natural events or industrial activities like Mn nodule mining) has been shown to be followed quickly by scavenging of dissolved heavy metals, e.g. released from interstitial water, on the resuspended particles. Compared to other deep-sea particles (like clay minerals, calcite and apatite), Mn and Fe oxides and oxyhydroxides were found to be by far the most important phases in scavenging many dissolved heavy metals. Only Pb was sorbed strongly on all particles used, with highest affinity to carbonate fluorapatite. Caesium + was significantly scavenged only by clay minerals like illite. The sorption experiments support a simple electrostatic model: Hydrated cations and labile cationic chloro-complexes in seawater like Mn 2+ , MnCl + , Co 2+ , Ni 2+ , Cu 2+ , Zn 2+ , Ba 2+ , and PbCl + , are preferentially adsorbed or ion-exchanged on the negatively charged surfaces of Mn oxides. In contrast, oxyanions and neutrally or negatively charged complexes like HVO 4 2- , MoO 4 2- , HAsO 4 2- , UO 2 (CO 3 ) 2 2- , and PbCO 3 0 associate with neutral to slightly positive amphoteric Fe oxyhydroxide particles. Metals forming strong chloro-complexes in seawater like Cd (CdCl 2 0 ), are less readily sorbed by oxides than others. A comparison of the results of voltammetric and radiotracer techniques revealed that after fast sorption within the first hour, isotopic exchange dominated reactions on MnO 2 -rich particles in the following days. This was especially pronounced for Mn and Co which are bound to the Mn oxide surface via a redox transformation

  11. Range-Dependent Acoustic Propagation in Shallow Water with Elastic Bottom Effects

    Science.gov (United States)

    2013-09-30

    Acoustic Propagation in Shallow Water with Elastic Bottom Effects 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d...This is the final version. The range-dependence models a seamount of approximately 400m in heigth and about 20km in range extent. The seamount is 2...The range-dependence models a seamount of approximately 400m in heighth and about 20km in range extent. The seamount is 2-dimensional. This is a

  12. Topological helical edge states in water waves over a topographical bottom

    Science.gov (United States)

    Wu, Shiqiao; Wu, Ying; Mei, Jun

    2018-02-01

    We present the discovery of topologically protected helical edge states in water wave systems, which are realized in water wave propagating over a topographical bottom whose height is modulated periodically in a two-dimensional triangular pattern. We develop an effective Hamiltonian to characterize the dispersion relation and use spin Chern numbers to classify the topology. Through full-wave simulations we unambiguously demonstrate the robustness of the helical edge states which are immune to defects and disorders so that the backscattering loss is significantly reduced. A spin splitter is designed for water wave systems, where helical edge states with different spin orientations are spatially separated with each other, and potential applications are discussed.

  13. Numerical Simulation Study on Steam-Assisted Gravity Drainage Performance in a Heavy Oil Reservoir with a Bottom Water Zone

    Directory of Open Access Journals (Sweden)

    Jun Ni

    2017-12-01

    Full Text Available In the Pikes Peak oil field near Lloydminster, Canada, a significant amount of heavy oil reserves is located in reservoirs with a bottom water zone. The properties of the bottom water zone and the operation parameters significantly affect oil production performance via the steam-assisted gravity drainage (SAGD process. Thus, in order to develop this type of heavy oil resource, a full understanding of the effects of these properties is necessary. In this study, the numerical simulation approach was applied to study the effects of properties in the bottom water zone in the SAGD process, such as the initial gas oil ratio, the thickness of the reservoir, and oil saturation of the bottom water zone. In addition, some operation parameters were studied including the injection pressure, the SAGD well pair location, and five different well patterns: (1 two corner wells, (2 triple wells, (3 downhole water sink well, (4 vertical injectors with a horizontal producer, and (5 fishbone well. The numerical simulation results suggest that the properties of the bottom water zone affect production performance extremely. First, both positive and negative effects were observed when solution gas exists in the heavy oil. Second, a logarithmical relationship was investigated between the bottom water production ratio and the thickness of the bottom water zone. Third, a non-linear relation was obtained between the oil recovery factor and oil saturation in the bottom water zone, and a peak oil recovery was achieved at the oil saturation rate of 30% in the bottom water zone. Furthermore, the operation parameters affected the heavy oil production performance. Comparison of the well patterns showed that the two corner wells and the triple wells patterns obtained the highest oil recovery factors of 74.71% and 77.19%, respectively, which are almost twice the oil recovery factors gained in the conventional SAGD process (47.84%. This indicates that the optimized SAGD process

  14. Effect of water flow rate and water chemistry on corrosion environment in reactor pressure vessel bottom of BWRs

    International Nuclear Information System (INIS)

    Ichikawa, Nagayoshi; Hemmi, Yukio; Takagi, Junichi; Urata, Hidehiro

    1999-01-01

    To evaluate the corrosion environment at the bottom of the reactor pressure vessel in a BWR and the effect of hydrogen water chemistry on the corrosion of materials in the region, measurements of the corrosion potential of Type-304 stainless steel and nickel base alloy were made in a laboratory test loop. The effect of water chemistry on the corrosion potential of nickel base alloy is found to be similar to the effect on Type-304 stainless steel. Flow analysis and precise evaluations of the corrosion potential of materials in the bottom region were implemented. Corrosion potentials throughout the region were evaluated from the flow analysis results. At the jet pump outlet and shroud support leg, a rather large amount of hydrogen had to be added to reduce the potential. Conversely, a small amount of hydrogen was enough in the case of the stub tube of the control rod drive guide tubing and the ICM housings located in the center of the bottom region. (author)

  15. Toward tracing routes of bottom waters in the Eastern Mediterranean basin using a multidisciplinary approach

    Science.gov (United States)

    Rubino, Angelo; Zanchettin, Davide; Bensi, Manuel; Cardin, Vanessa; Hainbucher, Dagmar; Baldi, Franco; Marchetto, Davide; Mapelli, Francesca; Borin, Sara

    2013-04-01

    We use near-bottom measurements of total mercury, biopolymeric carbon and its constituents, microbial activities, and bacterial diversity to attempt tracing routes of convectively generated bottom waters toward the abyss of the Eastern Mediterranean basin. The advantage of employing these parameters -which are often linked to persistent biological activities rather than to episodic flow phenomena- to complement the traditionally used ones (temperature, salinity, and dissolved oxygen) is twofold: they can yield valuable information even when the values of temperature and salinity in competing sources are virtually indistinguishable and they can allow also for a spatial and temporal integration of the export of newly formed deep waters. In our case study -the Eastern Mediterranean basin, which can be considered as a miniature global ocean - the proposed method seems to be able to capture two different exporting routes from the northern convective source and one exporting route from the eastern convective source, thus elucidating further aspects of the structure and variability of the local deep stratification.

  16. Re-initiation of bottom water formation in the East Sea (Japan Sea) in a warming world.

    Science.gov (United States)

    Yoon, Seung-Tae; Chang, Kyung-Il; Nam, SungHyun; Rho, TaeKeun; Kang, Dong-Jin; Lee, Tongsup; Park, Kyung-Ae; Lobanov, Vyacheslav; Kaplunenko, Dmitry; Tishchenko, Pavel; Kim, Kyung-Ryul

    2018-01-25

    The East Sea (Japan Sea), a small marginal sea in the northwestern Pacific, is ventilated deeply down to the bottom and sensitive to changing surface conditions. Addressing the response of this marginal sea to the hydrological cycle and atmospheric forcing would be helpful for better understanding present and future environmental changes in oceans at the global and regional scales. Here, we present an analysis of observations revealing a slowdown of the long-term deepening in water boundaries associated with changes of water formation rate. Our results indicate that bottom (central) water formation has been enhanced (reduced) with more (less) oxygen supply to the bottom (central) layer since the 2000s. This paper presents a new projection that allows a three-layered deep structure, which retains bottom water, at least until 2040, contrasting previous results. This projection considers recent increase of slope convections mainly due to the salt supply via air-sea freshwater exchange and sea ice formation and decrease of open-ocean convections evidenced by reduced mixed layer depth in the northern East Sea, resulting in more bottom water and less central water formations. Such vigorous changes in water formation and ventilation provide certain implications on future climate changes.

  17. The estimation of turnover time in the Japan Sea bottom water by 129I

    International Nuclear Information System (INIS)

    Suzuki, Takashi; Togawa, Orihiko; Minakawa, Masayuki

    2010-01-01

    It is well known that the Japan Sea is sensitive for the environment such a global warming. To understand the oceanic circulation in the Japan Sea, we estimated a turnover time and a potential formation rate of the Japan Sea bottom water (JSBW) using an oceanographic tracer of 129 I. The turnover time of JSBW was calculated based on the increased concentration during the nuclear era. The turnover time was estimated to be 180 - 210 years. The potential formation rate of JSBW is calculated based on the existence of the anthropogenic 129 I in the JSBW. The potential formation rate of JSBW is estimated to be (3.6-4.1) x 10 12 m 3 /y which is consistent with another estimation and is about quarter of that of the upper Japan Sea proper water. (author)

  18. Antarctic Bottom Water temperature changes in the western South Atlantic from 1989 to 2014

    Science.gov (United States)

    Johnson, Gregory C.; McTaggart, Kristene E.; Wanninkhof, Rik

    2014-12-01

    Warming of abyssal waters in recent decades contributes to global heat uptake and sea level rise. Repeat oceanographic section data in the western South Atlantic taken mostly in 1989 (1995 across the Scotia Sea), 2005, and 2014 are used to quantify warming in abyssal waters that spread northward through the region from their Antarctic origins in the Weddell Sea. While much of the Scotia Sea warmed between 1995 and 2005, only the southernmost portion, on the north side of the Weddell Gyre, continued to warm between 2005 and 2014. The abyssal Argentine Basin also warmed between 1989 and 2005, but again only the southernmost portion continued to warm between 2005 and 2014, suggesting a slowdown in the inflow of the coldest, densest Antarctic Bottom Waters into the western South Atlantic between 1989 and 2014. In contrast, the abyssal waters of the Brazil Basin warmed both between 1989 and 2005 and between 2005 and 2014, at a rate of about 2 m°C yr-1. This warming is also assessed in terms of the rates of change of heights above the bottom for deep isotherms in each deep basin studied. These results, together with findings from previous studies, suggest the deep warming signal observed in the Weddell Sea after the mid-1970s Weddell Polynya was followed by abyssal warming in the Argentine Basin from the late 1970s through about 2005, then warming in the deep Vema Channel from about 1992 through at least 2010, and warming in the Brazil Basin from 1989 to 2014.

  19. Quality of water and chemistry of bottom sediment in the Rillito Creek basin, Tucson, Arizona, 1986-92

    Science.gov (United States)

    Tadayon, Saeid; Smith, C.F.

    1994-01-01

    Data were collected on physical properties and chemistry of 4 surface water, l4 ground water, and 4 bottom sediment sites in the Rillito Creek basin where artificial recharge of surface runoff is being considered. Concentrations of suspended sediment in streams generally increased with increases in streamflow and were higher during the summer. The surface water is a calcium and bicarbonate type, and the ground water is calcium sodium and bicarbonate type. Total trace ek=nents in surface water that exceeded the U.S. Environmental Protection Agency primary maximum contaminant levels for drinking-water standards were barium, beryllium, cadmium, chromium, lead, mercury and nickel. Most unfiltered samples for suspended gross alpha as uranium, and unadjusted gross alpha plus gross beta in surface water exceeded the U.S. Environmental Protection Agency and the State of Arizona drinking-water standards. Comparisons of trace- element concentrations in bottom sediment with those in soils of the western conterminous United States generally indicate similar concentrations for most of the trace elements, with the exceptions of scandium and tin. The maximum concentration of total nitrite plus nitrate as nitrogen in three ground- samples and total lead in one ground-water sample exceeded U.S. Environmental Protection Agency primary maximum contaminant levels for drinking- water standards, respectively. Seven organochlorine pesticides were detected in surface-water samples and nine in bottom-sediment samples. Three priority pollutants were detected in surface water, two were detected in ground water, and eleven were detected in bottom sediment. Low concentrations of oil and grease were detected in surface-water and bottom- sediment samples.

  20. Property changes of deep and bottom waters in the Western Tropical Atlantic

    Science.gov (United States)

    Herrford, Josefine; Brandt, Peter; Zenk, Walter

    2017-06-01

    The flow of North Atlantic Deep Water (NADW) and Antarctic Bottom Water (AABW) contributes to the Atlantic meridional overturning circulation. Changes in the associated water mass formation might impact the deep ocean's capacity to take up anthropogenic CO2 while a warming of the deep ocean significantly contributes to global sea level rise. Here we compile historic and recent shipboard measurements of hydrography and velocity to provide a comprehensive view of water mass distribution, pathways, along-path transformation and long-term temperature changes of NADW and AABW in the western South and Equatorial Atlantic. We confirm previous results which show that the northwest corner of the Brazil Basin represents a splitting point for the southward/northward flow of NADW/AABW. The available measurements sample water mass transformation along the two major routes for deep and bottom waters in the tropical to South Atlantic - along the deep western boundary and eastward, parallel to the equator - as well as the hot-spots of extensive mixing. We find lower NADW and lighter AABW to form a highly interactive transition layer in the northern Brazil Basin. The AABW north of 5°S is relatively homogeneous with only lighter AABW being able to pass through the Equatorial Channel (EQCH) into the North Atlantic. Spanning a period of 26 years, our data also allow an estimation of long-term temperature trends in abyssal waters. We find a warming of 2.5±0.7•10-3 °C yr-1 of the waters in the northern Brazil Basin at temperatures colder than 0.6 °C throughout the period 1989-2014 and can relate this warming to a thinning of the dense AABW layer. Whereas isopycnal heave is the dominant effect which defines the vertical distribution of temperature trends on isobars, we also find temperature changes on isopycnals in the lower NADW and AABW layers. There temperatures on isopycnals exhibit decadal variations with warming in the 1990s and cooling in the 2000s - the contributions to the

  1. Coastal Freshening Prevents Fjord Bottom Water Renewal in Northeast Greenland: A Mooring Study From 2003 to 2015

    Science.gov (United States)

    Boone, Wieter; Rysgaard, Søren; Carlson, Daniel F.; Meire, Lorenz; Kirillov, Sergei; Mortensen, John; Dmitrenko, Igor; Vergeynst, Leendert; Sejr, Mikael K.

    2018-03-01

    The freshwater content of the Arctic Ocean and its bordering seas has recently increased. Observing freshening events is an important step toward identifying the drivers and understanding the effects of freshening on ocean circulation and marine ecosystems. Here we present a 13 year (2003-2015) record of temperature and salinity in Young Sound-Tyrolerfjord (74°N) in Northeast Greenland. Our observations show that strong freshening occurred from August 2005 to August 2007 (-0.92 psu or -0.46 psu yr-1) and from August 2009 to August 2013 (-0.66 psu or -0.17 psu yr-1). Furthermore, temperature-salinity analysis from 2004 to 2014 shows that freshening of the coastal water ( range at sill depth: 33.3 psu in 2005 to 31.4 psu in 2007) prevented renewal of the fjord's bottom water. These data provide critical observations of interannual freshening rates in a remote fjord in Greenland and in the adjacent coastal waters and show that coastal freshening impacts the fjord hydrography, which may impact the ecosystem dynamics in the long term.

  2. Benthic iron and phosphorus release from river dominated shelf sediments under varying bottom water O2 concentrations.

    Science.gov (United States)

    Ghaisas, N. A.; Maiti, K.; White, J. R.

    2017-12-01

    Phosphorus (P) cycling in coastal ocean is predominantly controlled by river discharge and biogeochemistry of the sediments. In coastal Louisiana, sediment biogeochemistry is strongly influenced by seasonally fluctuating bottom water O2, which, in turn transitions the shelf sediments from being a sink to source of P. Sediment P-fluxes were 9.73 ± 0.76 mg / m2 /d and 0.67±0.16 mg/m2/d under anaerobic and aerobic conditions respectively, indicating a 14 times higher P-efflux from oxygen deprived sediments. A high sedimentary oxygen consumption rate of 889 ± 33.6 mg/m2/d was due to organic matter re-mineralization and resulted in progressively decreasing the water column dissolved O2 , coincident with a P-flux of 7.2 ± 5.5 mg/m2/d from the sediment. Corresponding water column flux of Fe total was 19.7 ± 7.80 mg/m2/d and the sediment-TP decreased from 545 mg/Kg to 513 mg/Kg. A simultaneous increase in pore water Fe and P concentrations in tandem with a 34.6% loss in sedimentary Fe-bound P underscores the importance of O2 on coupled Fe- P biogeochemistry. This study suggests that from a 14,025 sq. km hypoxia area, Louisiana shelf sediments can supply 1.33x105 kg P/day into the water column compared to 0.094 x 105 kg P/day during the fully aerobic water column conditions.

  3. GAMMA-SPECTROMETER FOR WATER AREAS AND BOTTOM SEDIMENTS RADIATION MONITORING

    Directory of Open Access Journals (Sweden)

    A. I. Zhukouski

    2016-01-01

    Full Text Available In order to solve the problem of continuous or periodic monitoring of water areas affected by radioactive contamination in the result of scheduled emissions in nuclear power plants or in the result of emergency situations in nuclear fuel cycle plants we need to develop measurement instruments with advanced mathematics and program support to assess the level of radioactive contamination with required accuracy. The aim of theoretical research was to optimize detection device construction, estimate spectrometer metrological parameters in given measurement geometries, and determine effective position of detection device in the process of in situ measurements. This device consists of spectrometric scintillation probe packed into sealed container (detection device based on NaI(T1 crystal of Ø 63 × 63 mm or Ø 63 × 160 mm size, cable reel with deep-sea cable and a tablet PC for data processing and displaying. The container withstands static hydraulic pressure up to 5 MPa and can be used for measurements at depths of 500 m maximum. Probe measures energy distribution of gammaradiation with energy from 70 keV to 3000 keV. The implemented three-dimensional system for detection device position and orientation determination allows automatic operation of the device (without operator for water areas or bottom sediment scanning. The spectrometer can output measurement results with threedimensional geographical coordinates as index maps of distribution with necessary resolution and accuracy. Monte Carlo models of spectrometer and controlled objects are developed in order to determine the detector response functions to given radionuclides in given measurement geometries without use of expensive standard measures of activity. Multifunction gamma-spectrometer for in situ radiation monitoring of water areas and bottom sediments was developed and constructed. In the result of theoretical researches the response functions have been calculated in the form of

  4. Importance of bottom-up approach in water management - sustainable development of catchment areas in Croatia

    Science.gov (United States)

    Pavic, M.; Cosic-Flajsig, G.; Petricec, M.; Blazevic, Z.

    2012-04-01

    Association for preservation of Croatian waters and sea SLAP is a non-governmental organization (NGO) that gathers more than 150 scientist, hydrologist and civil engineers. SLAP has been established in 2006 and since then had organized many conferences and participated in projects dealing with water management. We have started our work developing plans to secure water supply to the 22 (21) villages in the rural parts of Dubrovnik (Pozega) area and trough the years we have accumulated knowledge and experience in dealing with stakeholders in hydrology and water management. Within this paper we will present importance of bottom-up approach to the stakeholders in water management in Croatia on two case studies: (1) Management of River Trebizat catchment area - irrigation of the Imotsko-Bekijsko rural parts; (2) Development of multipurpose water reservoirs at the River Orljava catchment area. Both projects were designed in the mid and late 1980's but due to the war were forgotten and on halt. River Trebizat meanders between Croatia and Bosnia and Herzegovina and acquires joint management by both countries. In 2010 and 2011 SLAP has organized conferences in both countries gathering all the relevant stakeholders from representatives of local and state governments, water management companies and development agencies to the scientist and interested NGO's. The conferences gave firm scientific background of the topic including presentation of all previous studies and measurements as well as model results but presented in manner appropriate to the stakeholders. The main result of the conference was contribution to the development of joint cross-border project sent to the EU Pre-Accession funds in December 2011 with the aim to strengthen capacities of both countries and prepare larger project dealing with management of the whole Trebizat catchment area to EU structural funds once Croatia enters EU in 2013. Similar approach was taken for the Orljava catchment in the northern

  5. Chemical evidence of the changes of the Antarctic Bottom Water ventilation in the western Ross Sea between 1997 and 2003

    Science.gov (United States)

    Rivaro, Paola; Massolo, Serena; Bergamasco, Andrea; Castagno, Pasquale; Budillon, Giorgio

    2010-05-01

    Data from three Italian CLIMA project cruises between 1997 and 2003 were used to obtain sections of the hydrographic and chemical properties of the main water masses across the shelf break off Cape Adare (western Ross Sea, Antarctica). Dissolved oxygen, nitrate and phosphate data were combined on the basis of the Redfield ratio to obtain the quasi-conservative tracers NO (9[NO 3]+[O 2]), PO (135[PO 4]+[O 2]) and phosphate star PO4* ( PO4*=[PO 4]+[O 2]/175-1.95). In 1997 and 2003 the presence of the High Salinity Shelf Water at the bottom depth near the sill was traced by both physical and chemical measurements. In 2001 the Modified Shelf Water, characterized by warmer temperature and by a lower dissolved oxygen content than High Salinity Shelf Water, was observed at the shelf edge. The distribution of the chemical tracers together with the hydrographic observations showed recently formed Antarctic Bottom Water on the continental slope during all of the cruises. These observations were confirmed by the extended optimum multiparameter analysis. The calculated thickness of the new Antarctic Bottom Water, as well as the tracer content, were variable in time and in space. The estimated volume of the new Antarctic Bottom Water and the export of dissolved oxygen and nutrient associated with the overflowing water were different over the examined period. In particular, a lower (˜55%) export was evidenced in 2001 compared to 1997.

  6. ESTIMATION OF MODERN CONDITION OF POLLUTION DEGREE OF WATER AND BOTTOM SEDIMENT OF THE SOUTHERN PART OF THE AGRAKHAN BAY

    Directory of Open Access Journals (Sweden)

    A. A. Gadzhiev

    2012-01-01

    Full Text Available The article presents the data obtained in the course of field research in the southern part of theAgrakhan Bay. As a result of research, conducted full hydrochemical analysis of water samples taken at nine stations. An estimate is given of the degree of pollution of water and bottom sediments of the oil products , phenols and heavy metals.

  7. Bottom water oxygenation changes in the northern Okinawa Trough since the last 88ka: Controlled by local hydrology and climate

    Science.gov (United States)

    Zou, Jianjun; Shi, Xuefa; Zhu, Aimei; Bai, Yazhi; Selvaraj, Kandasamy

    2014-05-01

    Dissolved oxygen content in oceanic bottom water is closely related to the surface organic carbon export and subsurface water stratification, regulating the biogeochemical cycles of some key nutrients and trace elements in intermediate and deep water columns. Further, the rate of organic carbon flux to sediments and bottom water oxygen concentration together determine the intensity of reducing conditions in sediments. In this study, we obtain high-resolution geochemical elements (TOC, TN, TS, CaCO3, Cd, U, Mn and Mo) in a radiocarbon (14C) and δ18O dated, sediment core CSH1 collected from the northern Okinawa Trough to reconstruct the history of bottom water redox conditions over 88 ka. Our data revealed the presence of hypoxic bottom water in the northern Okinawa Trough during late MIS5a-early MIS4, Last Glacial Maximum, and the early Last Deglacial intervals. During the Holocene and the early MIS5a, the dissolved oxygen content in bottom water has increased with decreasing water stratification, which was probably caused by the increased upwelling from the bottom in tandem with the climbing of Kuroshio Current and subdued freshwater effect in the northern Okinawa Trough. The reasons that caused the change of dissolved oxygen content in bottom water in the northern Okinawa Trough varied during different periods. The main factors are related to sea level, strengths of East Asian monsoon and the Kuroshio Current, and the shift of Westerly Jet Axis. The semi-closed topography in the northern Okinawa Trough provides a space framework for the presence of anoxia, while the sea level together with the Kuroshio Current, the East Asian monsoon and the Westerly Jet Axis seems to affect the strength of water stratification and the nutrient supply; thereby, regulating the dissolved oxygen exchange between surface and bottom waters. This work was supported by the National Natural Science Foundation of China(Grant No.:40906035,40710069004) and by basic scientific fund for

  8. Application of hydrogen water chemistry to moderate corrosive circumstances around the reactor pressure vessel bottom of boiling water reactors

    International Nuclear Information System (INIS)

    Uchida, Shunsuke; Ibe, Eishi; Nakata, Kiyatomo; Fuse, Motomasa; Ohsumi, Katsumi; Takashima, Yoshie

    1995-01-01

    Many efforts to preserve the structural integrity of major piping, components, and structures in a boiling water reactor (BWR) primary cooling system have been directed toward avoiding intergranular stress corrosion cracking (IGSCC). Application of hydrogen water chemistry (HWC) to moderate corrosive circumstances is a promising approach to preserve the structural integrity during extended lifetimes of BWRs. The benefits of HWC application are (a) avoiding the occurrence of IGSCC on structural materials around the bottom of the crack growth rate, even if microcracks are present on the structural materials. Several disadvantage caused by HWC are evaluated to develop suitable countermeasures prior to HWC application. The advantages and disadvantages of HWC are quantitatively evaluated base on both BWR plant data and laboratory data shown in unclassified publications. Their trade-offs are discussed, and suitable applications of HWC are described. It is concluded that an optimal amount of Hydrogen injected into the feedwater can moderate corrosive circumstances, in the region to be preserved, without serious disadvantages. The conclusions have been drawn by combining experimental and theoretical results. Experiments in BWR plants -- e.g., direct measurements of electrochemical corrosion potential and crack growth rate at the RPV bottom -- are planned that would collect data to support the theoretical considerations

  9. Dynamics of phosphorus forms in the bottom sediments and their interstitial water for the Prut River (Moldova).

    Science.gov (United States)

    Rusu, Vasile; Postolachi, Larisa; Povar, Igor; Alder, Alfredo; Lupascu, Tudor

    2012-09-01

    Phosphorus concentration in rivers results from both external inputs and internal loading from the bottom sediments. Seasonal, spatial, and multi-annual dynamics of phosphorus forms in bottom sediments and their interstitial water for the river Prut (Moldova) were evaluated. In order to determine content of total phosphorus in the bottom sediments, fresh (wet) samples were subjected to persulfate oxidation. The content of inorganic phosphorus was determined after acidic oxidation of samples. The amount of organic phosphorus was obtained by subtracting inorganic phosphorus from the amount of total phosphorus. Content of phosphorus forms in interstitial water was determined after centrifugation of fresh (wet) sediments. In general, the shape of dynamics of the amounts of inorganic phosphorus in sediments was close during years 2009, 2010, and 2011, with registered higher contents of this form on the middle course of the river. The spatial dynamics of organic phosphorus is less homogeneous along the Prut River. During 2009, higher amounts of organic phosphorus were recorded on the middle sector. During the spring of year 2010, the content of organic phosphorus in sediments was practically not changed along the river. The ratio of inorganic/organic phosphorus in bottom sediments was similar during the researched years, with the predominance of the inorganic phosphorus being recorded. Also, the increasing tendency of the percentage of organic phosphorus from spring to summer was identified. Generally, appropriate spatial and seasonal dynamics of phosphorus forms in bottom sediments and their interstitial water were recorded, although sometimes with some differences.

  10. Arsenic remediation of drinking water using iron-oxide coated coal bottom ash

    Energy Technology Data Exchange (ETDEWEB)

    MATHIEU, JOHANNA L.; GADGIL, ASHOK J.; ADDY, SUSAN E.A.; KOWOLIK, KRISTIN

    2010-06-01

    We describe laboratory and field results of a novel arsenic removal adsorbent called 'Arsenic Removal Using Bottom Ash' (ARUBA). ARUBA is prepared by coating particles of coal bottom ash, a waste material from coal fired power plants, with iron (hydr)oxide. The coating process is simple and conducted at room temperature and atmospheric pressure. Material costs for ARUBA are estimated to be low (~;;$0.08 per kg) and arsenic remediation with ARUBA has the potential to be affordable to resource-constrained communities. ARUBA is used for removing arsenic via a dispersal-and-removal process, and we envision that ARUBA would be used in community-scale water treatment centers. We show that ARUBA is able to reduce arsenic concentrations in contaminated Bangladesh groundwater to below the Bangladesh standard of 50 ppb. Using the Langmuir isotherm (R2 = 0.77) ARUBA's adsorption capacity in treating real groundwater is 2.6x10-6 mol/g (0.20 mg/g). Time-to-90percent (defined as the time interval for ARUBA to remove 90percent of the total amount of arsenic that is removed at equilibrium) is less than one hour. Reaction rates (pseudo-second-order kinetic model, R2>_ 0.99) increase from 2.4x105 to 7.2x105 g mol-1 min-1 as the groundwater arsenic concentration decreases from 560 to 170 ppb. We show that ARUBA's arsenic adsorption density (AAD), defined as the milligrams of arsenic removed at equilibrium per gram of ARUBA added, is linearly dependent on the initial arsenic concentration of the groundwater sample, for initial arsenic concentrations of up to 1600 ppb and an ARUBA dose of 4.0 g/L. This makes it easy to determine the amount of ARUBA required to treat a groundwater source when its arsenic concentration is known and less than 1600 ppb. Storing contaminated groundwater for two to three days before treatment is seen to significantly increase ARUBA's AAD. ARUBA can be separated from treated water by coagulation and clarification, which is expected to

  11. Achieving integrated urban water management: planning top-down or bottom-up?

    Science.gov (United States)

    Gabe, J; Trowsdale, S; Vale, R

    2009-01-01

    Integrated Urban Water Management (IUWM) acknowledges a broad range of environmental and socio-economic outcomes but the link between design intentions and operational performance is not always clear. This may be due in part to a lack of shared principles that remove bias and inconsistency in assessing the operational performance of IUWM. This paper investigates the possibility of developing shared principles through examination of shared objectives and shared indicators within two logical and integrated frameworks for urban residential developments that aspire for IUWM and sustainable development. The framework method was applied using very different approaches-one a top-down urban planning process, the other a bottom-up community consultation process. Both frameworks highlight the extent to which IUWM is part of a broad social and environmental system. Core environmental performance objectives and indicators were very similar, highlighting the potential to develop shared principles in reporting and benchmarking the environmental performance of neighbourhood developments. Socio-economic indicators were highly variable due to process and likely contextual differences, thus it is unclear if the influence of IUWM on these variables can transcend the social context unless the practice of urban water management can expand its core responsibility beyond "hard" physical infrastructure.

  12. Estimating Discharge, Depth and Bottom Friction in Sand Bed Rivers Using Surface Currents and Water Surface Elevation Observations

    Science.gov (United States)

    Simeonov, J.; Czapiga, M. J.; Holland, K. T.

    2017-12-01

    We developed an inversion model for river bathymetry estimation using measurements of surface currents, water surface elevation slope and shoreline position. The inversion scheme is based on explicit velocity-depth and velocity-slope relationships derived from the along-channel momentum balance and mass conservation. The velocity-depth relationship requires the discharge value to quantitatively relate the depth to the measured velocity field. The ratio of the discharge and the bottom friction enter as a coefficient in the velocity-slope relationship and is determined by minimizing the difference between the predicted and the measured streamwise variation of the total head. Completing the inversion requires an estimate of the bulk friction, which in the case of sand bed rivers is a strong function of the size of dune bedforms. We explored the accuracy of existing and new empirical closures that relate the bulk roughness to parameters such as the median grain size diameter, ratio of shear velocity to sediment fall velocity or the Froude number. For given roughness parameterization, the inversion solution is determined iteratively since the hydraulic roughness depends on the unknown depth. We first test the new hydraulic roughness parameterization using estimates of the Manning roughness in sand bed rivers based on field measurements. The coupled inversion and roughness model is then tested using in situ and remote sensing measurements of the Kootenai River east of Bonners Ferry, ID.

  13. Surface hydration drives rapid water imbibition into strongly hydrophilic nanopores.

    Science.gov (United States)

    Fang, Chao; Qiao, Rui

    2017-08-09

    The imbibition of liquids into nanopores plays a critical role in numerous applications, and most prior studies focused on imbibition due to capillary flows. Here we report molecular simulations of the imbibition of water into single mica nanopores filled with pressurized gas. We show that, while capillary flow is suppressed by the high gas pressure, water is imbibed into the nanopore through surface hydration in the form of monolayer liquid films. As the imbibition front moves, the water film behind it gradually densifies. Interestingly, the propagation of the imbibition front follows a simple diffusive scaling law. The effective diffusion coefficient of the imbibition front, however, is more than ten times larger than the diffusion coefficient of the water molecules in the water film adsorbed on the pore walls. We clarify the mechanism for the rapid water imbibition observed here.

  14. New model and field data on estimates of Antarctic Bottom Water flow through the deep Vema Channel

    Science.gov (United States)

    Frey, D. I.; Fomin, V. V.; Diansky, N. A.; Morozov, E. G.; Neiman, V. G.

    2017-05-01

    We used a numerical model of the ocean circulation with a high spatial resolution to obtain estimates of the kinematic characteristics of Antarctic Bottom Water flow through the abyssal Vema Channel in the southwestern part of the Atlantic Ocean. The results of simulations correspond to the data of direct velocity measurements made at several locations in the channel. The high horizontal and vertical resolution of the model in the bottom layer allowed us to study in detail the hydrodynamics of this flow over its entire length.

  15. Effect of the Discharge Water which Mixed Sewage Disposal Water with Seawater Desalting Treated Sewage for Bottom Sediment and Hypoxic Water Mass

    Science.gov (United States)

    Watanabe, Ryoichi; Yamasaki, Koreyoshi; Minagawa, Tomoko; Iyooka, Hiroki; Kitano, Yoshinori

    For every time in summer season, hypoxic water mass has formed at the inner part of Hakata Bay. Field observation study has carried out at the inner part of Hakata Bay since 2004 with the particular aim of tracking the movement of hypoxic water mass. Hypoxic water masses form the end of June to September on this area because the consumption of oxygen in bottom water layers exceeds the re-supply of oxygen from the atmosphere. Under such hypoxic conditions, the seawater desalination plant has begun to use in 2005. After seawater desalination plant operation starting, hypoxic water mass tends to improve. In this research, the authors show the following result. After seawater desalination plant has begun to operate, the hypoxia around the mixed discharge water outlet tends to be improved.

  16. Environmental complexity of a port: Evidence from circulation of the water masses, and composition and contamination of bottom sediments.

    Science.gov (United States)

    Cutroneo, L; Carbone, C; Consani, S; Vagge, G; Canepa, G; Capello, M

    2017-06-15

    Ports are complex environments due to their complicated geometry (quays, channels, and piers), the presence of human activities (vessel traffic, shipyards, industries, and discharges), and natural factors (stream and torrent inputs, sea action, and currents). Taking these factors into consideration, we have examined the marine environment of a port from the point of view of the circulation of the water masses, hydrological characteristics, distribution of the sediment grain-size, mineralogical characteristics, and metal concentrations of the bottom sediments. Our results show that, in the case of the Port of Genoa (north-western Italy), the impact of human activities (such as a coal power-plant, oil depots, shipyards, dredging of the bottom sediments, etc.), natural processes (such as currents, fresh water and sediment inputs from the torrents), and the morphology of the basin, are important factors in the sediment, water, and metal distributions that have given rise to a complex environment. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Detection of reactive oxygen species supplied into the water bottom by atmospheric non-thermal plasma jet using iodine-starch reaction

    Science.gov (United States)

    Kawasaki, Toshiyuki; Eto, Wataru; Hamada, Masaki; Wakabayashi, Yasutaka; Abe, Yasufumi; Kihara, Keisuke

    2015-08-01

    The supply of reactive oxygen species (ROS) to a target through liquid by plasma jet should be clarified. In this study, a non-thermal plasma jet was irradiated onto the water surface in atmospheric air, and the ROS reaching the water bottom were detected using a gel reagent with iodine-starch reactions. As a result, two-dimensional ROS distributions were visually obtained at the bottom, and the relative ROS concentration was obtained by absorbance measurement. Oxygen addition to helium led to a higher ROS supply into the bottom than helium plasma jet and ozone exposure. A doughnut-shaped ROS distribution was clearly observed at the bottom under certain conditions. The ROS concentration at the bottom significantly depended on irradiation distance and water layer thickness. It is observed from the results obtained using a liquid reagent that the plasma-jet-induced flow and the mixing effect play an important role in ROS supply into the bottom.

  18. Three-Dimensional Acoustic Propagation Through Shallow Water Internal, Surface Gravity and Bottom Sediment Waves

    Science.gov (United States)

    2011-09-01

    and large ( sand waves) transverse bedforms [21]. Note that in the literature the term ” sand dunes ” can refer to both sand waves and megaripples...Bottom ripples have wave- lengths of centimeters, whereas the length scales of megaripples and sand waves are tens and even hundreds of meters. The last...number. Full field numerical modeling of low frequency sound propaga- tion through large sand waves located on a sloped bottom was performed using the

  19. A new mini box corer for sampling muddy bottoms in antarctic shallow waters

    Directory of Open Access Journals (Sweden)

    Carlos Alejandro Echeverría

    2009-06-01

    Full Text Available A new Mini Box Corer (MBC-GEAMB was developed for bottom sampling in Antarctic shallow waters down to 100 m depth from a small vessel. It consists of a detachable stainless steel box with a total sampling area of 0.0625 m², and a closing arm with a detachable blade without an external frame. MBC allowed stratified bottom sampling and good quality samples comparable to those obtained through diving. A comparison between the MBC-GEAMB and a 0.056 m²van Veen grab (VV was undertaken for the benthic macrofaunal composition in Admiralty Bay, King George Island (Antarctica. MBC and VV samples were taken from three depths (20, 30 and 60m in two sites. Total densities sampled with the MBC were up to 10 times higher than those obtained with van Veen grab. VV samples might lead to faunistic abundance underestimation compared to the MBC samples. Besides, MBC showed a higher performance on discriminating different sites as regards total macrofaunal density. It is suggested that MBC could be employed as an efficient remote sampling device for shallow-waters where direct sampling by SCUBA was not advisable.Um novo Mini Box Corer (MBC-GEAMB foi desenvolvido para amostragens de fundo em águas rasas antárticas até 100 metros de profundidade, a partir de embarcações pequenas. Consiste em uma caixa de aço inox destacável com uma área total de amostragem de 0,0625 m², e um braço de fechamento com uma lâmina destacável, sem um suporte externo. MBC permite a amostragem estratificada do sedimento de fundo com amostras de qualidade comparáveis àquelas obtidas através de mergulho autônomo. Uma comparação entre o MBC-GEAMB e um van Veen de área 0,056 m²(VV foi realizada utilizando a composição da macrofauna bentônica na Baía do Almirantado, (Ilha Rei George, Antarctica. Amostragens com MBC e VV foram realizadas em três profundidades (20, 30 e 60m em dois locais. As densidades totais obtidas com o MBC foram até 10 vezes maiores que as obtidas

  20. Basicities of Strong Bases in Water: A Computational Study

    OpenAIRE

    Kaupmees, Karl; Trummal, Aleksander; Leito, Ivo

    2014-01-01

    Aqueous pKa values of strong organic bases – DBU, TBD, MTBD, different phosphazene bases, etc – were computed with CPCM, SMD and COSMO-RS approaches. Explicit solvent molecules were not used. Direct computations and computations with reference pKa values were used. The latter were of two types: (1) reliable experimental aqueous pKa value of a reference base with structure similar to the investigated base or (2) reliable experimental pKa value in acetonitrile of the investigated base itself. ...

  1. Millennial-scale changes of surface and bottom water conditions in the northwestern Pacific during the last deglaciation

    Science.gov (United States)

    Kim, Sunghan; Khim, Boo-Keun; Ikehara, Ken; Itaki, Takuya; Shibahara, Akihiko; Yamamoto, Masanobu

    2017-07-01

    Changes in water column conditions in the northwestern Pacific during the last 23 ka were reconstructed using geochemical and isotope proxies and redox elemental compositions along with published data (alkenone sea surface temperature (SST) and benthic foraminiferal fauna) at core GH02-1030. Surface water primary productivity in terms of biogenic opal and TOC contents, which mainly represented export production of diatom, was closely related to alkenone (spring-summer) SST and the development of spring-summer mixed layer depth. The different variation patterns of nitrate and silicic acid utilization, estimated by bulk δ15N and δ30Sidiatom values, respectively, are most likely due to the water column denitrification influence on bulk δ15N. Dysoxic bottom water conditions occurred during the Bølling-Allerød (BA) and the Pre-Boreal (PB), which was evident by laminated sediments, abundant dysoxic benthic foraminifers, and increased redox elemental compositions. Although surface water productivity increased during the BA and PB, dysoxic bottom water conditions were caused by a combination of enhanced surface water productivity and reduced ventilation of North Pacific Intermediate Water (NPIW) in response to meltwater input from the high latitude areas. Based on records of core GH02-1030 and other cores in the northwestern Pacific, the Okhotsk Sea, and the Bering Sea, which are all proximal to the modern NPIW source region, dissolved oxygen concentrations of bottom water were more depleted during the BA than PB. Such difference was attributed to more sluggish NPIW ventilation due to more meltwater input during the BA than the PB. The opening or closure of the Bering Strait is critical to the direction of meltwater transport to the northwestern Pacific.

  2. Examination of abyssal sea floor and near-bottom water mixing processes using Ra-226 and Rn-222

    International Nuclear Information System (INIS)

    Key, R.M.

    1981-01-01

    Since Broecker's (1965) original work, extensive studies have been made on abyssal near-bottom water-mixing processes using the radioactive parent-daughter pair radium-226 (Ra) - radon-222 (Rn). One assumption critical to all of these studies is that sediments immediately under a given water column are the source of excess radon (=Rn concentration - Ra concentration) found in bottom waters. Since 1965 theoretical works of increasing complexity have tried to explain areal variations of excess radon and radium. However, Key et al. (1979b) have reported the only extensive measurements of radium and radon in bottom water and sediments at the same location. This dissertation is an expansion of that work both in theory and in scope. A diagenetic sediment model based on the work of Schink and Guinasso (1978), Cochran (1979), and Key et al. (1979b) was developed to model Ra-Rn in near-surface abyssal sediments. In order to maximize model application information, the degrees of freedom were minimized by measuring as many of the model parameters as possible. The most glaring discrepancy found was that measured near-surface total radium profiles could not be fit using plutonium-derived bioturbation rates. There is an implication that plutonium profiles modeled with currently accepted bioturbation models do not give a true indication of the real biologically induced mixing process. After adjusting for this problem in the source function, diagenetic theory explains near-surface radon-distributions adequately. Using both the adjusted diagenetic model and the empirical model developed by Key et al. (1979b), reasonable agreement was found between the sedimentary radon deficit and near-bottom water surplus. Inadequacy of present diagenetic theory makes any attempt to differentiate sedimentary radium sources academic

  3. Rainy Periods and Bottom Water Stagnation Initiating Brine Accumulation and Metal Concentrations, 2. Precambrian Gold-Uranium Ore Beds and Banded Iron Formations

    Science.gov (United States)

    Rossignol-Strick, Martine

    1987-08-01

    I previously suggested that heavy runoff during the 12,500-7000 years B.P. tropical pluvial period generated bottom water quiescence and reducing conditions making possible sapropel formation, accumulation of brine originating at the sea bottom, and long-term preservation of hydrothermal sulfides in the Red Sea Deeps. I hypothesized the same process to account for two Precambrian strata-bound ores. In the Upper Witwatersrand paleoplacers, South Africa, gold and uranium eroded by running water from upstream greenstones, reached highest concentrations in association with organic matter in carbonaceous seams, and deposited in the distal end of fluvial fans during transgressive phases. I propose that the deep waters over these fans became anoxic when large, sudden floods stratified the water column. The organic matter thus locally preserved concentrated gold and uranium from the partial dissolution of the detrital metallic grains. In the Hamersley basin of Western Australia, banded iron formations (BIF) of the Dales Gorge Member are a major source of iron ore. Regularly fluctuating environmental conditions are shown by repetitious BIF and black shale macrobands. I propose that they were deposited in a confined, silled, deep basin connected with the open ocean. Before initiation of the lowest BIF deposition the active regional thermohaline circulation flushing the deep waters under a rather arid climate diluted and oxidized the Fe2+-rich hydrothermal effluents exhaling from the basin floor. Then, during a strong wet period, heavy runoff scavenging volcanoclastics from the land surface lowered the basin surface water salinity and prevented deepwater renewal. The hydrothermal effluents began to accumulate and progressively concentrated in the quiescent and progressively oxygen-depleted deep water. During this wet initial phase, the massive black, organic-rich pyritic shale at the top of the Mount McRae Shale Member was deposited immediately and conformably underlying the

  4. A Synoptic View of the Ventilation and Circulation of Antarctic Bottom Water from Chlorofluorocarbons and Natural Tracers.

    Science.gov (United States)

    Purkey, Sarah G; Smethie, William M; Gebbie, Geoffrey; Gordon, Arnold L; Sonnerup, Rolf E; Warner, Mark J; Bullister, John L

    2018-01-03

    Antarctic Bottom Water (AABW) is the coldest, densest, most prolific water mass in the global ocean. AABW forms at several distinct regions along the Antarctic coast and feeds into the bottom limb of the meridional overturning circulation, filling most of the global deep ocean. AABW has warmed, freshened, and declined in volume around the globe in recent decades, which has implications for the global heat and sea level rise budgets. Over the past three decades, the use of tracers, especially time-varying tracers such as chlorofluorocarbons, has been essential to our understanding of the formation, circulation, and variability of AABW. Here, we review three decades of temperature, salinity, and tracer data and analysis that have led to our current knowledge of AABW and how the southern component of deep-ocean ventilation is changing with time.

  5. A Synoptic View of the Ventilation and Circulation of Antarctic Bottom Water from Chlorofluorocarbons and Natural Tracers

    Science.gov (United States)

    Purkey, Sarah G.; Smethie, William M.; Gebbie, Geoffrey; Gordon, Arnold L.; Sonnerup, Rolf E.; Warner, Mark J.; Bullister, John L.

    2018-01-01

    Antarctic Bottom Water (AABW) is the coldest, densest, most prolific water mass in the global ocean. AABW forms at several distinct regions along the Antarctic coast and feeds into the bottom limb of the meridional overturning circulation, filling most of the global deep ocean. AABW has warmed, freshened, and declined in volume around the globe in recent decades, which has implications for the global heat and sea level rise budgets. Over the past three decades, the use of tracers, especially time-varying tracers such as chlorofluorocarbons, has been essential to our understanding of the formation, circulation, and variability of AABW. Here, we review three decades of temperature, salinity, and tracer data and analysis that have led to our current knowledge of AABW and how the southern component of deep-ocean ventilation is changing with time.

  6. Thermodynamic Study of Water Activity of Single Strong Electrolytes

    Directory of Open Access Journals (Sweden)

    Seyed Hossein Hashemi

    2017-06-01

    Full Text Available Today, due to the natural decline of oil exploitation, the use of methods of oil recovery, has made significant progress. However, these methods are accompanied by accumulation and deposition of mineral deposits in oil field installations. In the present study, aqueous solutions, strontium sulfate, barium sulfate, manganese sulfate and nickel sulfate are studied, in terms of EUNIQUAC model and genetic algorithms. Based on the findings of this article, as temperature increases, in order to increase the solubility of the system, the ionic strength decreases; but with increasing pressure, the solubility of barium sulfate increases. Meanwhile, in this article, to evaluate water activity, aqueous solutions of manganese sulfate and nickel sulfate is studied.

  7. Forcing of a bottom-mounted circular cylinder by steep regular water waves at finite depth

    DEFF Research Database (Denmark)

    Paulsen, Bo Terp; Bredmose, Henrik; Bingham, Harry B.

    2014-01-01

    surface, but the strong nonlinear motion of the free surface was included. The numerical model was verified and validated by grid convergence and by comparison to relevant experimental measurements. First-order convergence towards an analytical solution was demonstrated and an excellent agreement...... with the experimental data was found. Time-domain computations of the normalized inline force history on the cylinder were analysed as a function of dimensionless wave height, water depth and wavelength. Here the dependence on depth was weak, while an increase in wavelength or wave height both lead to the formation...... at the back of the cylinder following the passage of the wave crest. The numerical computations were further analysed in the frequency domain. For a representative example, the secondary load cycle was found to be associated with frequencies above the fifth- and sixth-harmonic force component. For the third...

  8. The occurrence of heavy metals and metal-resistant bacteria in water and bottom sediments of the Straszyn reservoir (Poland)

    Science.gov (United States)

    Kulbat, Eliza; Sokołowska, Aleksandra

    2017-11-01

    The aim of this study is to investigate the distribution of selected heavy metals and metal-resistant bacteria in water and bottom sediments of the surface drinking water reservoir for Gdańsk. The following sequence of metals in regard to metal concentration in sediments can be written down: Zn > Pb > Cu > Cd. The evaluation of metals accumulation was performed using the Müller index, to indicate the bottom sediment's contamination and geochemical classification of sediment quality according to Polish standards. The Müller geochemical index was changing in a wide range: water (raw and treated water) showed a resistance to 0.2 mM and 2 mM concentrations of zinc, copper and lead. The highest percentages of metal-resistant bacteria were recorded in the sediments of the reservoir (60%-88%). The share of metal-resistant strains in the raw water was significantly lower (34%-61%). The results indicate also that water treatment processes may contribute to the selection of resistant strains.

  9. The footprint of bottom trawling in European waters: distribution, intensity, and seabed integrity

    DEFF Research Database (Denmark)

    Eigaard, Ole Ritzau; Bastardie, Francois; Hinzen, N.T.

    2017-01-01

    Mapping trawling pressure on the benthic habitats is needed as background to support an ecosystem approach to fisheries management. The extent and intensity of bottom trawling on the European continental shelf (0-1000 m) was analysed from logbook statistics and vessel monitoring system data for 2...

  10. Hyperspectral signatures and WorldView-3 imagery of Indian River Lagoon and Banana River Estuarine water and bottom types

    Science.gov (United States)

    Bostater, Charles R.; Oney, Taylor S.; Rotkiske, Tyler; Aziz, Samin; Morrisette, Charles; Callahan, Kelby; Mcallister, Devin

    2017-10-01

    Hyperspectral signatures and imagery collected during the spring and summer of 2017 and 2016 are presented. Ground sampling distances (GSD) and pixel sizes were sampled from just over a meter to less than 4.0 mm. A pushbroom hyperspectral imager was used to calculate bidirectional reflectance factor (BRF) signatures. Hyperspectral signatures of different water types and bottom habitats such as submerged seagrasses, drift algae and algal bloom waters were scanned using a high spectral and digital resolution solid state spectrograph. WorldView-3 satellite imagery with minimal water wave sun glint effects was used to demonstrate the ability to detect bottom features using a derivative reflectance spectroscopy approach with the 1.3 m GSD multispectral satellite channels centered at the solar induced fluorescence band. The hyperspectral remote sensing data collected from the Banana River and Indian River Lagoon watersheds represents previously unknown signatures to be used in satellite and airborne remote sensing of water in turbid waters along the US Atlantic Ocean coastal region and the Florida littoral zone.

  11. A Determination of an Abrupt Motion of the Sea Bottom by Using Snapshot Data of Water Waves

    Directory of Open Access Journals (Sweden)

    T. S. Jang

    2012-01-01

    Full Text Available This paper presents an inverse problem and its solution procedure, which are aimed at identifying a sudden underwater movement of the sea bottom. The identification is mathematically shown to work with a known snapshot data of generated water wave configurations. It is also proved that the problem has a unique solution. However, the inverse problem is involved in an integral equation of the first kind, resulting in an ill-posed problem in the sense of stability. That is, the problem lacks solution stability properties. To overcome the difficulty of solution instability, in this paper, a stabilization technique, called regularization, is incorporated in the present solution procedure for the identification of the sea bottom movement. A numerical experiment is presented to demonstrate that the proposed (numerical solution procedure operates.

  12. Deep and bottom water export from the Southern Ocean to the Pacific over the past 38 million years

    Science.gov (United States)

    van de Flierdt, T.; Frank, M.; Halliday, A.N.; Hein, J.R.; Hattendorf, B.; Gunther, D.; Kubik, P.W.

    2004-01-01

    The application of radiogenic isotopes to the study of Cenozoic circulation patterns in the South Pacific Ocean has been hampered by the fact that records from only equatorial Pacific deep water have been available. We present new Pb and Nd isotope time series for two ferromanganese crusts that grew from equatorial Pacific bottom water (D137-01, "Nova," 7219 m water depth) and southwest Pacific deep water (63KD, "Tasman," 1700 m water depth). The crusts were dated using 10Be/9Be ratios combined with constant Co-flux dating and yield time series for the past 38 and 23 Myr, respectively. The surface Nd and Pb isotope distributions are consistent with the present-day circulation pattern, and therefore the new records are considered suitable to reconstruct Eocene through Miocene paleoceanography for the South Pacific. The isotope time series of crusts Nova and Tasman suggest that equatorial Pacific deep water and waters from the Southern Ocean supplied the dissolved trace metals to both sites over the past 38 Myr. Changes in the isotopic composition of crust Nova are interpreted to reflect development of the Antarctic Circumpolar Current and changes in Pacific deep water circulation caused by the build up of the East Antarctic Ice Sheet. The Nd isotopic composition of the shallower water site in the southwest Pacific appears to have been more sensitive to circulation changes resulting from closure of the Indonesian seaway. Copyright 2004 by the American Geophysical Union.

  13. Distribution of shallow water soft and hard bottom seabeds in the Isla del Coco National Park, Pacific Costa Rica

    Directory of Open Access Journals (Sweden)

    Jeffrey A. Sibaja-Cordero

    2012-11-01

    Full Text Available Geographic Information Systems (GIS applications used in marine habitats are powerful tools for management and monitoring of marine reserves and resources. Here, we present a series of maps of the soft and hard substrates in the shallow waters (>80 m depth of Parque Nacional Isla del Coco (PNIC= Isla del Coco National Park. We use bathymetry data and field data as input for a GIS, GAM, and kriging methods to generate a series of maps that describe the bottom characteristics. Eight types of bottom were found in the PNIC by composition and grain size. The shore of the island and islets consisted of rocky formations (mainly basalts, with coral reefs in the subtidal of some areas. Rhodolith beds had a dispersing distribution. The bottom on the southern and southwestern region is hard substrate, while sediments cover the northern and northeastern zones. Slightly gravelly sand dominated the bays, while gravelly sand (with more coarse grains was frequent offshore. The inner areas of Chatham and Wafer bays have mud and organic matter. The sediments in the area are mostly carbonates, except in Bahía Yglesias where clastic sediments (from the erosion of basalts are presented. The information generated in this study could be a valuable input for future monitoring in the PNIC.

  14. The role of Argopecten purpuratus shells structuring the soft bottom community in shallow waters of southern Peru

    Science.gov (United States)

    Lomovasky, Betina J.; Gamero, Patricia A.; Romero, Leonardo; Firstater, Fausto N.; Gamarra Salazar, Alex; Hidalgo, Fernando; Tarazona, Juan; Iribarne, Oscar O.

    2015-12-01

    Accumulation of Argopecten purpuratus shells often occurs after El Niño events in shallow waters of Independencia Bay (14°17‧S-76°10‧W; Pisco, Peru). Here we experimentally investigate the effects of their shell accumulation on macrobenthos assemblages in soft bottom, shallow areas of the bay. A field experiment (from May 2006 to May 2007), including four treatments with different coverage levels of empty shells of A. purpuratus, were randomly arranged in: (1) areas devoid of shells ("Empty" treatment: experimental control), (2) 50% of the plot area covered with shells haphazardly distributed over the bottom ("medium" treatment), (3) 100% of the plot area covered with shells, forming a 10 cm valve layer ("full" treatment) and (4) "natural control". We found a total of 124 taxa throughout the experiment. Polychaetes, crustaceans and mollusks were the most abundant groups in "natural controls", dominated by the gastropod Nassarius gayi and the polychaetes Prionospio peruana, Platynereis bicanaliculata and Mediomastus branchiferus. The abundance of individuals (N) and the species richness (S) were higher in the "medium" treatment, but only in one month under positive sea bottom thermal anomalies. Similarity analysis (Bray-Curtis) showed that "natural control", "empty" and "full" treatments were more similar among them than the "medium" treatment. Multidimensional analysis showed no clear species association among treatments and a higher grouping among the samplings of Jun-06, Aug-06 and Nov-06. Our results also showed that the commercial crab Romaleon polyodon and the polyplacophora Tonicia elegans were positively affected by shell accumulations ("medium" treatment), while the limpet Fissurella crassa was negatively affected. Our study shows that directly by changing habitat structure or indirectly by changing sediment characteristics, the addition of scallop shells to the soft bottom can modify the macrobenthic assemblage; however, the seasonal oceanographic

  15. Critical heat flux of water in vertical tubes with an upper plenum and a closed bottom

    International Nuclear Information System (INIS)

    Kim, Hong Chae; Baek, Won Pil; Chang, Soon Heung

    2000-01-01

    An experimental study is conducted for vertical round tubes with an upper plenum and a closed bottom to investigate CHF behavior and CHF onset location under the counter-current condition. The measured CHF values are well predicted by general Wallis type flooding correlations. A 1-D steady state analytical flooding model for thermosyphon by El-Genk and Saber was assessed with the data and the liquid film thickness at the liquid entrance was calculated. The CHF onset position becomes different with L/D and D, and liquid entrance geometry affects only CHF values not CHF onset positions

  16. The oxygen content of ocean bottom waters, the burial efficiency of organic carbon, and the regulation of atmospheric oxygen.

    Science.gov (United States)

    Betts, J N; Holland, H D

    1991-01-01

    Data for the burial efficiency of organic carbon with marine sediments have been compiled for 69 locations. The burial efficiency as here defined is the ratio of the quantity of organic carbon which is ultimately buried to that which reaches the sediment-water interface. As noted previously, the sedimentation rate exerts a dominant influence on the burial efficiency. The logarithm of the burial efficiency is linearly related to the logarithm of the sedimentation rate at low sedimentation rates. At high sedimentation rates the burial efficiency can exceed 50% and becomes nearly independent of the sedimentation rate. The residual of the burial efficiency after the effect of the sedimentation rate has been subtracted is a weak function of the O2 concentration in bottom waters. The scatter is sufficiently large, so that the effect of the O2 concentration in bottom waters on the burial efficiency of organic matter could be either negligible or a minor but significant part of the mechanism that controls the level of O2 in the atmosphere.

  17. The oxygen content of ocean bottom waters, the burial efficiency of organic carbon, and the regulation of atmospheric oxygen

    Science.gov (United States)

    Betts, J. N.; Holland, H. D.

    1991-01-01

    Data for the burial efficiency of organic carbon with marine sediments have been compiled for 69 locations. The burial efficiency as here defined is the ratio of the quantity of organic carbon which is ultimately buried to that which reaches the sediment-water interface. As noted previously, the sedimentation rate exerts a dominant influence on the burial efficiency. The logarithm of the burial efficiency is linearly related to the logarithm of the sedimentation rate at low sedimentation rates. At high sedimentation rates the burial efficiency can exceed 50% and becomes nearly independent of the sedimentation rate. The residual of the burial efficiency after the effect of the sedimentation rate has been subtracted is a weak function of the O2 concentration in bottom waters. The scatter is sufficiently large, so that the effect of the O2 concentration in bottom waters on the burial efficiency of organic matter could be either negligible or a minor but significant part of the mechanism that controls the level of O2 in the atmosphere.

  18. Numerical model for a watering plan to wash out organic matter from the municipal solid waste incinerator bottom ash layer in closed system disposal facilities.

    Science.gov (United States)

    Ishii, Kazuei; Furuichi, Toru; Tanikawa, Noboru

    2009-02-01

    Bottom ash from municipal solid waste incineration (MSWI) is a main type of waste that is landfilled in Japan. The long-term elution of organic matter from the MSWI bottom ash layers is a concern because maintenance and operational costs of leachate treatment facilities are high. In closed system disposal facilities (CSDFs), which have a roof to prevent rainfall from infiltrating into the waste layers, water must be supplied artificially and its quantity can be controlled. However, the quantity of water needed and how to apply it (the intensity, period and frequency) have not been clearly defined. In order to discuss an effective watering plan, this study proposes a new washout model to clarify a fundamental mechanism of total organic carbon (TOC) elution behavior from MSWI bottom ash layers. The washout model considers three phases: solid, immobile water and mobile water. The parameters, including two mass transfer coefficients of the solid-immobile water phases and immobile-mobile water phases, were determined by one-dimensional column experiments for about 2 years. The intensity, period and frequency of watering and other factors were discussed based on a numerical analysis using the above parameters. As a result, our washout model explained adequately the elution behavior of TOC from the MSWI bottom ash layer before carbonation occurred (pH approximately 8.3). The determined parameters and numerical analysis suggested that there is a possibility that the minimum amount of water needed for washing out TOC per unit weight of MSWI bottom ash layer could be determined, which depends on the two mass transfer coefficients and the depth of the MSWI bottom ash layer. Knowledge about the fundamental mechanism of the elution behavior of TOC from the MSWI bottom ash layer before carbonation occurs, clarified by this study, will help an effective watering plan in CSDFs.

  19. Records of wells, water levels, and chemical quality of ground water in the French Prairie-Mission Bottom area, northern Willamette Valley, Oregon

    Science.gov (United States)

    Price, Don

    1961-01-01

    An investigation of the ground-water resources of the northern Willamette Valley was begun in 1960 as a cooperative program between the Ground Water Branch, U.S. Geological Survey, and the Oregon State Engineer. The northern Willamette Valley area is one of the fastest growing areas of ground-water use within the state. The purpose of the investigation is to obtain an understanding of the availability, movement, and chemical quality of the ground-water resources of the area. This information is needed to attain an optimum development of the ground-water resources of the area and to aid in the prevention of problems of overdevelopment and pollution. The first phase of the program was the collection of well records, water level records, and chemical quality data in the central part of this area, which is known as the French Prairie-Mission Bottom area. The records collected in this phase of the study are essential in the preparation of an interpretive report describing the occurrence and movement of ground-water in the French Prairie-Mission Bottom area. These records, which will not be included in the interpretive report that is being prepared at this time, are being made available in this publication to aid in the location and the development of the ground-water resources of the area, and to serve as a supplement to the forthcoming interpretive report.

  20. Contrasting fates of organic matter in locations having different organic matter inputs and bottom water O2 concentrations

    Science.gov (United States)

    Mai-Thi, Ngoc-Nu; St-Onge, Guillaume; Tremblay, Luc

    2017-11-01

    The goals of this work were to study sedimentary organic matter (OM) composition and transformation since the end of the last deglaciation and to evaluate the influence of contrasting depositional conditions on these parameters. One station was located in the Lower St. Lawrence Estuary (LSLE) where the current bottom waters are hypoxic and receive terrigenous and marine OM. The other station, located in the Gulf of St. Lawrence (GSL), has more oxygenated bottom waters and almost only marine OM inputs. Analyses included enantiomers of amino acids (L and D-AA) and muramic acid that provide different markers of OM alteration state and reactivity and of bacterial contribution to OM composition and diagenesis. The markers clearly indicated the increase in OM alteration state with depth in the sediments of the LSLE and the GSL. The steady decrease in AA yields with depth confirmed the preferential degradation of AA compared to the rest of the OM. The OM in the surface sediment of the LSLE was less altered than that of the GSL and was enriched in bacterial biomass as indicated by much higher muramic acid yields. Results indicated that an important degradation of particulate organic matter occurs in the water column in the GSL, while it takes place mostly in the sediments in the LSLE. The presence of heterogeneous OM and hypoxic conditions in the LSLE likely reduce OM degradation rate in its deep water layer. However, the zone near the water-sediment interface is responsible for large variations in AA composition at both locations. A relatively new redox index, based on AA composition, was tested and appeared robust. This study highlights the importance of ambient conditions in determining the fate of OM and in the biogeochemical cycles of vital elements.

  1. Analytical model for bottom reflooding heat transfer in light water reactors (the UCFLOOD code)

    International Nuclear Information System (INIS)

    Arrieta, L.; Yadigaroglu, G.

    1978-08-01

    The UCFLOOD code is based on mechanistic models developed to analyze bottom reflooding of a single flow channel and its associated fuel rod, or a tubular test section with internal flow. From the hydrodynamic point of view the flow channel is divided into a single-phase liquid region, a continuous-liquid two-phase region, and a dispersed-liquid region. The void fraction is obtained from drift flux models. For heat transfer calculations, the channel is divided into regions of single-phase-liquid heat transfer, nucleate boiling and forced-convection vaporization, inverted-annular film boiling, and dispersed-flow film boiling. The heat transfer coefficients are functions of the local flow conditions. Good agreement of calculated and experimental results has been obtained. A code user's manual is appended

  2. Development of a GPS buoy system for monitoring tsunami, sea waves, ocean bottom crustal deformation and atmospheric water vapor

    Science.gov (United States)

    Kato, Teruyuki; Terada, Yukihiro; Nagai, Toshihiko; Koshimura, Shun'ichi

    2010-05-01

    bottom positions with a few centimeters in accuracy. The system is now operational for more than ten sites along the Japanese coasts. Currently, however, the measurements are not continuous but have been done once to several times a year using a boat. If a GPS and acoustic system is placed on a buoy, ocean bottom position could be monitored in near real-time and continuous manner. This will allow us to monitor more detailed and short term crustal deformations at the sea bottom. Another application plan is for an atmospheric research. Previous researchers have shown that GPS is capable of measuring atmospheric water vapor through estimating tropospheric zenith delay measurements of GPS at the sea surface. Information of water vapor content and its temporal variation over sea surface will much contribute to weather forecast on land which has mostly been conducted only by land observations. Considering that the atmospheric mass moves from west to east in general in and around Japanese islands, information of water vapor together with other atmospheric data from an array of GPS buoy placed in the west of Japanese Islands, will much improve weather forecast. We try to examine if this is also feasible. As a conclusion of a series of GPS buoy experiments, we could assert that GPS buoy system will be a powerful tool to monitor ocean surface and much contribute to provide safe and secure life of people.

  3. CHARACTERISTICS OF SPATIAL DISTRIBUTION OF PHOSPHORUS AND NITROGEN IN THE BOTTOM SEDIMENTS OF THE WATER RESERVOIR PORAJ

    Directory of Open Access Journals (Sweden)

    Katarzyna Rozpondek

    2017-07-01

    Full Text Available The aim of this study was to determine the content of phosphorus and nitrogen in the bottom sediments of the Poraj Reservoir located on the Warta River, along with defining their spatial distribution and the relationship between these elements and organic matter, aluminum and iron. Samples of bottom sediments were collected on the basis of regular measurement grid of 46 points located in the area of the water reservoir Poraj. The collected samples were analyzed in terms of content of following elements, which values are in range: total phosphorus (TP 0,06 – 5,06 g/kg, total nitrogen (TN 0,17 – 9,66 g/kg, organic matter (OM 0,49 - 28,41% of solid content, aluminum (Al 2,44 - 145,15 g/kg and iron (Fe 0,28 - 16,50 g/kg. By using of GIS system, spatial distribution of obtained results of laboratory analyzes were interpolated (Inverse Distance Weighted method was used. On basis of spatial distribution it was noted that in northern part of water reservoir bottom sediments have greater values of TP, TN and OM than in southern part. The study also included calculation of correlation between: OM and TN (n=46, R^2= 0,9335, TN and Fe (n=46, R^2= 0,8782, TN and Al (n=46, R^2= 0,8629, OM and Fe (n=46, R^2= 0,8243, OM and Al (n=46, R^2= 0,7981, TP and Fe (n=46, R^2= 0,7456, TP and Al (n=46, R^2= 0,6209. The presented pilot studies show that the potential content of phosphorus, nitrogen and organic matter in the sediments of the water reservoir Poraj can reach a significant level. The need to plan and carry out further research allowing the evaluation of the properties of the analyzed elements and examining their potential impact on water quality in the tested water reservoir was stated.

  4. Summer Bottom Trawl Survey

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Sampling the coastal waters of the Gulf of Maine using the Northeast Fishery Science Center standardized bottom trawl has been problematic due to large areas of hard...

  5. Effects of transient bottom water currents and oxygen concentrations on benthic exchange rates as assessed by eddy correlation measurements

    DEFF Research Database (Denmark)

    Holtappels, Moritz; Glud, Ronnie N.; Doris, Daphne

    2013-01-01

    Eddy correlation (EC) measurements in the benthic boundary layer (BBL) allow estimating benthic O2 uptake from a point distant to the sediment surface. This noninvasive approach has clear advantages as it does not disturb natural hydrodynamic conditions, integrates the flux over a large foot......-print area and allows many repetitive flux measurements. A drawback is, however, that the measured flux in the bottom water is not necessarily equal to the flux across the sediment-water interface. A fundamental assumption of the EC technique is that mean current velocities and mean O2 concentrations......, which is comparable to the O2 uptake of shelf sediments. Second, the case of transient velocities was examined with a 2D k-ε turbulence model demonstrating that the vertical flux can be biased by 30–100% for several hours during changing current velocities from 2 to 10 cm s−1. Results are compared...

  6. Bottom attenuation estimation using sound intensity fluctuations due to mode coupling by nonlinear internal waves in shallow water.

    Science.gov (United States)

    Grigorev, Valery A; Katsnelson, Boris G; Lynch, James F

    2016-11-01

    Analyses of fluctuations of low frequency signals (300 ± 30 Hz) propagating in shallow water in the presence of nonlinear internal waves (NIWs) in the Shallow Water 2006 experiment are carried out. Signals were received by a vertical line array at a distance of ∼20 km from the source. A NIW train was moving totally inside of the acoustic track, and the angle between the wave front of the NIW and the acoustic track in the horizontal plane was ∼10°. It is shown that the spectrum of the sound intensity fluctuations contains peaks corresponding to the coupling of pairs of propagating modes. Analysis of spectra at different hydrophone depths, and also summed over depth allows the authors to estimate attenuation in the bottom sediments.

  7. Bottoming organic Rankine cycle configurations to increase Internal Combustion Engines power output from cooling water waste heat recovery

    International Nuclear Information System (INIS)

    Peris, Bernardo; Navarro-Esbrí, Joaquín; Molés, Francisco

    2013-01-01

    This work is focused on waste heat recovery of jacket cooling water from Internal Combustion Engines (ICEs). Cooling water heat does not always find use due to its low temperature, typically around 90 °C, and usually is rejected to the ambient despite its high thermal power. An efficient way to take benefit from the ICE cooling water waste heat can be to increase the power output through suitable bottoming Organic Rankine Cycles (ORCs). Thereby, this work simulates six configurations using ten non flammable working fluids and evaluates their performances in efficiency, safety, cost and environmental terms. Results show that the Double Regenerative ORC using SES36 gets the maximum net efficiency of 7.15%, incrementing the ICE electrical efficiency up to 5.3%, although requires duplicating the number of main components and high turbine size. A more rigorous analysis, based on the system feasibility, shows that small improvements in the basic cycle provide similar gains compared to the most complex schemes proposed. So, the single Regenerative ORC using R236fa and the Reheat Regenerative ORC using R134a seem suitable cycles which provide a net efficiency of 6.55%, incrementing the ICE electrical efficiency up to 4.9%. -- Highlights: • Suitable bottoming cycles for ICE cooling water waste heat recovery are studied. • Non flammable working fluids and various ORC configurations are evaluated. • Double regenerative cycle using SES36 is the most efficient configuration. • Regenerative and reheat regenerative ORCs seem feasible cycles. • Electrical efficiency of the ICE can be improved up to 5.3%

  8. Governing for Integrated Water and Flood Risk Management: Comparing Top-Down and Bottom-Up Approaches in Spain and California

    Directory of Open Access Journals (Sweden)

    Anna Serra-Llobet

    2016-10-01

    Full Text Available Flood risk management in the context of Integrated Water Resource Management (IWRM is becoming widely accepted as an approach to improving resilience in light of increasing flood risks due to climate change and other factors. This paper contributes to a better understanding of the governance arrangements needed for effectively implement integrated approaches to managing flood risk. We compare how IWRM and flood risk management have been operationalized within “top-down” and “bottom-up” governance arrangements in the European Union and the United States. We focus in particular on two case study regions, the Catalan coastal region in Spain and the San Francisco Bay Area in California, which have strong similarities in economy, climate, and environmental values, but different institutional settings. Our findings contribute empirical evidence of the need for a balance between “top-down” and “bottom-up” approaches. While the San Francisco Bay Area’s strongly collaborative and participatory approach has generated new connections among flood managers and other stakeholders, the lack of a central entity with the capacity and mandate for on-going coordination and region-wide risk assessments appears to constrain its ability to support integrated and adaptive management. The European Union’s top-down approach and the presence of a central authority at the river basin scale have led to a consolidated regional plan in Catalonia encompassing all phases of flood risk management, but the degree of engagement and opportunities for knowledge-sharing among participants may be more limited.

  9. Final Scientific/Technical Report: Characterizing the Response of the Cascadia Margin Gas Hydrate Reservoir to Bottom Water Warming Along the Upper Continental Slope

    Energy Technology Data Exchange (ETDEWEB)

    Solomon, Evan A. [Univ. of Washington, Seattle, WA (United States); Johnson, H. Paul [Univ. of Washington, Seattle, WA (United States); Salmi, Marie [Univ. of Washington, Seattle, WA (United States); Whorley, Theresa [Univ. of Washington, Seattle, WA (United States)

    2017-11-10

    continental shelf at water depths <180 m and at the upper limit of methane hydrate stability along the Washington margin. 5) The majority of the seeps cored during the 2014 research expedition on the R/V Thompson contained abundant authigenic carbonate indicating that they are locations of long-lived seepage rather than emergent seep systems related to methane hydrate dissociation. Despite the evidence for enhanced methane seepage at the upper limit of methane hydrate stability along the Washington margin, we found no unequivocal evidence for active methane hydrate dissociation as a source of fluid and gas at the seeps surveyed. The pore fluid and bottom water chemistry shows that the seeps are fed by a variety of fluid and methane sources, but that methane hydrate dissociation, if occurring, is not widespread and is only a minor source (below the detection limit of our methods). Collectively, these results provide a significant advance in our understanding of the thermal structure of the Cascadia subduction zone and the fluid and methane sources feeding seeps along the upper continental slope of the Washington-sector of the Cascadia margin. Though we did not find unequivocal evidence for methane hydrate dissociation as a source of water and methane at the upper pressure-temperature limit of methane hydrate stability at present, continued warming of North Pacific Intermediate Water in the future has the potential to impact the methane hydrate reservoir in sediments at greater depths along the slope. Thus, this study provides a strong foundation and the necessary characterization of the background state of seepage at the upper limit of methane hydrate stability for future investigations of this important process.

  10. Bottom head assembly

    International Nuclear Information System (INIS)

    Fife, A.B.

    1998-01-01

    A bottom head dome assembly is described which includes, in one embodiment, a bottom head dome and a liner configured to be positioned proximate the bottom head dome. The bottom head dome has a plurality of openings extending there through. The liner also has a plurality of openings extending there through, and each liner opening aligns with a respective bottom head dome opening. A seal is formed, such as by welding, between the liner and the bottom head dome to resist entry of water between the liner and the bottom head dome at the edge of the liner. In the one embodiment, a plurality of stub tubes are secured to the liner. Each stub tube has a bore extending there through, and each stub tube bore is coaxially aligned with a respective liner opening. A seat portion is formed by each liner opening for receiving a portion of the respective stub tube. The assembly also includes a plurality of support shims positioned between the bottom head dome and the liner for supporting the liner. In one embodiment, each support shim includes a support stub having a bore there through, and each support stub bore aligns with a respective bottom head dome opening. 2 figs

  11. Comparison of Mercury in Water, Bottom Sediment, and Zooplankton in Two Front Range Reservoirs in Colorado, 2008-09

    Science.gov (United States)

    Mast, M. Alisa; Krabbenhoft, David P.

    2010-01-01

    The U.S. Geological Survey, in cooperation with the Colorado Department of Public Health and Environment, conducted a study to investigate environmental factors that may contribute to the bioaccumulation of mercury in two Front Range reservoirs. One of the reservoirs, Brush Hollow Reservoir, currently (2009) has a fish-consumption advisory for mercury in walleye (Stizostedion vitreum), and the other, Pueblo Reservoir, which is nearby, does not. Water, bottom sediment, and zooplankton samples were collected during 2008 and 2009, and a sediment-incubation experiment was conducted in 2009. Total mercury concentrations were low in midlake water samples and were not substantially different between the two reservoirs. The only water samples with detectable methylmercury were collected in shallow areas of Brush Hollow Reservoir during spring. Mercury concentrations in reservoir bottom sediments were similar to those reported for stream sediments from unmined basins across the United States. Despite higher concentrations of fish-tissue mercury in Brush Hollow Reservoir, concentrations of methylmercury in sediment were as much as 3 times higher in Pueblo Reservoir. Mercury concentrations in zooplankton were at the low end of concentrations reported for temperate lakes in the Northeastern United States and were similar between sites, which may reflect the seasonal timing of sampling. Factors affecting bioaccumulation of mercury were assessed, including mercury sources, water quality, and reservoir characteristics. Atmospheric deposition was determined to be the dominant source of mercury; however, due to the proximity of the reservoirs, atmospheric inputs likely are similar in both study areas. Water-quality constituents commonly associated with elevated concentrations of mercury in fish (pH, alkalinity, sulfate, nutrients, and dissolved organic carbon) did not appear to explain differences in fish-tissue mercury concentrations between the reservoirs. Low methylmercury

  12. Improvement of the free-surface tension model in shallow water basin by using in-situ bottom-friction measurements

    Science.gov (United States)

    Alekseenko, Elena; Kuznetsov, Konstantin; Roux, Bernard

    2016-04-01

    Wind stress on the free surface is the main driving force behind the circulation of the upper part of the ocean, which in hydrodynamic models are usually defined in terms of the coefficient of surface tension (Zhang et al., 2009, Davies et al., 2003). Moreover, wave motion impacts local currents and changes sea level, impacts the transport and the stratification of the entire water column. Influence of surface waves at the bottom currents is particularly pronounced in the shallow coastal systems. However, existing methods of parameterization of the surface tension have significant limits, especially in strong wind waves (Young et al., 2001, Jones et al., 2004) due to the difficulties of measuring the characteristics of surface waves in stormy conditions. Thus, the formula for calculating the coefficient of surface tension in our day is the actual problem in modeling fluid dynamics, particularly in the context of strong surface waves. In the hydrodynamic models usually a coefficient of surface tension is calculated once at the beginning of computation as a constant that depends on the averaged wind waves characteristic. Usually cases of strongly nonlinear wind waves are not taken into account, what significantly reduces the accuracy of the calculation of the flow structures and further calculation of the other processes in water basins, such as the spread of suspended matter and pollutants. Thus, wave motion influencing the pressure on the free surface and at the bottom must be considered in hydrodynamic models particularly in shallow coastal systems. A method of reconstruction of a free-surface drag coefficient based on the measured in-situ bottom pressure fluctuations is developed and applied in a three-dimensional hydrodynamic model MARS3D, developed by the French laboratory of IFREMER (IFREMER - French Research Institute for Marine Dynamics). MARS3D solves the Navier-Stokes equations for incompressible fluid in the Boussinesq approximation and with the

  13. Automatic non-destructive three-dimensional acoustic coring system for in situ detection of aquatic plant root under the water bottom

    Directory of Open Access Journals (Sweden)

    Katsunori Mizuno

    2016-05-01

    Full Text Available Digging is necessary to detect plant roots under the water bottom. However, such detection is affected by the transparency of water and the working skills of divers, usually requires considerable time for high-resolution sampling, and always damages the survey site. We developed a new automatic non-destructive acoustic measurement system that visualizes the space under the water bottom, and tested the system in the in situ detection of natural plant roots. The system mainly comprises a two-dimensional waterproof stage controlling unit and acoustic measurement unit. The stage unit was electrically controlled through a notebook personal computer, and the space under the water bottom was scanned in a two-dimensional plane with the stage unit moving in steps of 0.01 m (±0.0001 m. We confirmed a natural plant root with diameter of 0.025–0.030 m in the reconstructed three-dimensional acoustic image. The plant root was at a depth of about 0.54 m and the propagation speed of the wave between the bottom surface and plant root was estimated to be 1574 m/s. This measurement system for plant root detection will be useful for the non-destructive assessment of the status of the space under the water bottom.

  14. A bottom-up approach of stochastic demand allocation in water quality modelling

    NARCIS (Netherlands)

    Blokker, E.J.M.; Vreeburg, J.H.G.; Beverloo, H.; Klein Arfman, M.; Van Dijk, J.C.

    2010-01-01

    An “all pipes” hydraulic model of a DMA-sized drinking water distribution system was onstructed with two types of demand allocations. One is constructed with the conventional op-down approach, i.e. a demand multiplier pattern from the booster station is llocated to all demand nodes with a correction

  15. Development process for integrated water resources management plan under a bottom-up participation perspective

    Directory of Open Access Journals (Sweden)

    Kittiwet Kuntiyawichai

    2014-06-01

    Full Text Available This article presents the development process for the integrated water resources management and development plan of Maha Sarakham Province by considering the priority and urgency of water problem issues. Gathering feedback from stakeholders and prioritizing water management and development projects are also taken into consideration. In view of integrated plans, the project is classified into short-, medium- and long-term plans with the project duration of 2 years, 3 years and 5 years, respectively. In this case, the plans can be categorized into proposed provincial and local plans. Firstly, the comprehensive provincial plans can be divided into 2 groups, i.e. district plans with the total number of 532 plans, which comprise of 505 projects for coping with drought and 27 projects for flood mitigation, and provincial plans from 13 agencies with the amount of 513 projects, which include 396 projects and 117 projects for dealing with drought and flood, respectively. Secondly, there are 4,099 of local plans to be put in place, in which 3,973 projects and 126 projects are proposed to handle drought and flood problems, respectively. From the analysis, it is found that if all planned drought relief projects are implemented, the water demand for domestic and agricultural needs could be covered by 96% and 51%, respectively. In case of the entire proposed flood alleviation projects are executed, 29% of the total flood prone areas can be effectively protected.

  16. A bottom-up approach of stochastic demand allocation in water quality modelling

    NARCIS (Netherlands)

    Blokker, E.J.M.; Vreeburg, J.H.G.; Beverloo, H.; Klein Arfman, M.; Van Dijk, J.C.

    2010-01-01

    An “all pipes” hydraulic model of a drinking water distribution system was constructed with two types of demand allocations. One is constructed with the conventional top-down approach, i.e. a demand multiplier pattern from the booster station is allocated to all demand nodes with a correction factor

  17. Coral by-catch in shrimp bottom trawl surveys in West Greenland waters (2010 – 2012)

    DEFF Research Database (Denmark)

    Jørgensbye, Helle; Arboe, Nanette Hammeken

    There have been zoological expeditions in Greenland waters since the 19th century documenting the sea life, including cold water corals. Coral trees (vernacular name for Paragorgia arborea) are mentioned as early as 1741 in the first natural history book about Greenland (Egede 1741). Due to the m......There have been zoological expeditions in Greenland waters since the 19th century documenting the sea life, including cold water corals. Coral trees (vernacular name for Paragorgia arborea) are mentioned as early as 1741 in the first natural history book about Greenland (Egede 1741). Due....... The identification of the corals is based on Kenchington et al. (2009). The identification of many specimens has further been verified by Ole Tendal (Zoological Museum, Copenhagen) on the basis of frozen samples. Few corals, mainly soft corals (Alcyonacea) and sea pens (Pennatulacea), were found in the depth range...... within which shrimp are fished. This first analysis suggests that dense fields of Sea Pens and patches of octocorals occur in the depth range and within the area covered by the shrimp fishery...

  18. Changes in Bottom Water Physical Properties Above the Mid-Atlantic Ridge Flank in the Brazil Basin

    Science.gov (United States)

    Zhao, Jian; Thurnherr, Andreas M.

    2018-01-01

    Warming of abyssal waters in recent decades has been widely documented around the global ocean. Here repeat hydrographic data collected in 1997 and 2014 near a deep fracture zone canyon in the eastern Brazil Basin are used to quantify the long-term change. Significant changes are found in the Antarctic Bottom Water (AABW) within the canyon. The AABW in 2014 was warmer (0.08 ± 0.06°C), saltier (0.01 ± 0.005), and less dense (0.005 ± 0.004 kg m-3) than in 1997. In contrast, the change in the North Atlantic Deep Water has complicated spatial structure and is almost indistinguishable from zero at 95% confidence. The resulting divergence in vertical displacement of the isopycnals modifies the local density stratification. At its peak, the local squared buoyancy frequency (N2) near the canyon is reduced by about 20% from 1997 to 2014. Similar reduction is found in the basinwide averaged profiles over the Mid-Atlantic Ridge flank along 25°W in years 1989, 2005, and 2014. The observed changes in density stratification have important implications for internal tide generation and dissipation.

  19. A bottom-up approach to identifying the maximum operational adaptive capacity of water resource systems to a changing climate

    Science.gov (United States)

    Culley, S.; Noble, S.; Yates, A.; Timbs, M.; Westra, S.; Maier, H. R.; Giuliani, M.; Castelletti, A.

    2016-09-01

    Many water resource systems have been designed assuming that the statistical characteristics of future inflows are similar to those of the historical record. This assumption is no longer valid due to large-scale changes in the global climate, potentially causing declines in water resource system performance, or even complete system failure. Upgrading system infrastructure to cope with climate change can require substantial financial outlay, so it might be preferable to optimize existing system performance when possible. This paper builds on decision scaling theory by proposing a bottom-up approach to designing optimal feedback control policies for a water system exposed to a changing climate. This approach not only describes optimal operational policies for a range of potential climatic changes but also enables an assessment of a system's upper limit of its operational adaptive capacity, beyond which upgrades to infrastructure become unavoidable. The approach is illustrated using the Lake Como system in Northern Italy—a regulated system with a complex relationship between climate and system performance. By optimizing system operation under different hydrometeorological states, it is shown that the system can continue to meet its minimum performance requirements for more than three times as many states as it can under current operations. Importantly, a single management policy, no matter how robust, cannot fully utilize existing infrastructure as effectively as an ensemble of flexible management policies that are updated as the climate changes.

  20. Modern Deep-sea Sponges as Recorders of Bottom Water Silicon Isotopes

    Science.gov (United States)

    Hendry, K. R.; Georg, R. B.; Rickaby, R. E.; Robinson, L. F.; Halliday, A. N.

    2008-12-01

    Major zones of opal accumulation in the world oceans have experienced geographical shifts during the Cenozoic coincident with times of transition in oceanic circulation and climate. The global marine silica cycle is likely to respond to various large-scale changes including the distillation of Si and other nutrients in ocean basins; weathering and continental inputs; and biological productivity in surface waters. These processes could potentially be distinguished by their impact on the isotopic composition of dissolved silica in the world oceans. Although diatoms dominate uptake of silica in surface waters, box-modelling (de la Rocha and Bickle, 2005) suggests that sponges spicules have a greater potential to reflect whole ocean changes in the silica cycle, by recording deep-water silicon isotopes. Here, we introduce a new calibration study of modern deep- sea sponges collected on a transect cruise across the Drake Passage, in the Southern Ocean, from a range of depths and seawater silicic acid concentrations. Sponges were collected by benthic trawling, and dried immediately. The spicules were later isolated from cellular material and cleaned for surface contaminants, before dissolution and analysis by NuPlasma HR MC-ICP-MS in medium resolution mode. We discuss our preliminary data, the extent to which inter and intraspecies variations reflect environmental conditions, and the implications for palaeoreconstructions of the marine silicon cycle. de la Rocha, C. and M. Bickle (2005). Sensitivity of silicon isotopes to whole-ocean changes in the silica cycle. Marine Geology 217, 267-282.

  1. Seasonal and inter-annual temperature variability in the bottom waters over the western Black Sea shelf

    Directory of Open Access Journals (Sweden)

    G. I. Shapiro

    2011-09-01

    Full Text Available Long-term changes in the state of the Bottom Shelf Water (BSW on the Western shelf of the Black Sea are assessed using analysis of intra-seasonal and inter-annual temperature variations. For the purpose of this study the BSW is defined as such shelf water mass between the seabed and the upper mixed layer (bounded by the σθ = 14.2 isopycnal which has limited ability to mix vertically with oxygen-rich surface waters during the warm season due to formation of a seasonal pycnocline. A long-term time series of temperature anomalies in the BSW is constructed from in-situ observations taken over the 2nd half of the 20th century. The BSW is shown to occupy nearly half of the shelf area during the summer stratification period (May–November.The results reveal a warm phase in the 1960s/70s, followed by a cold phase between 1985 and 1995 and a further warming after 1995. The transition between the warm and cold periods coincides with a regime shift in the Black Sea ecosystem. While it was confirmed that the memory of winter convection is well preserved over the following months in the deep sea, the signal of winter cooling in the BSW significantly reduces during the warm season. The potential of the BSW to ventilate horizontally during the warm season with the deep-sea waters is assessed using isopycnic analysis of temperature variations. It is shown that temperature in the BSW is stronger correlated with the temperature of Cold Intermediate Waters (CIW in the deep sea than with the severity of the previous winters, thus indicating that the isopycnal exchanges with the deep sea are more important for inter-annual/inter-decadal variability of the BSW on the western Black Sea shelf than effects of winter convection on the shelf itself.

  2. Strong Water Isotopic Anomalies in the Martian Atmosphere: Probing Current and Ancient Reservoirs

    Science.gov (United States)

    Villanueva, G. L.; Mumma, M. J.; Novak, R. E.; Käufl, H. U.; Hartogh, P.; Encrenaz, T.; Tokunaga, A.; Khayat, A.; Smith, M. D.

    2015-01-01

    We measured maps of atmospheric water (H2O) and its deuterated form (HDO) across the martian globe, showing strong isotopic anomalies and a significant high deuterium/hydrogen (D/H) enrichment indicative of great water loss. The maps sample the evolution of sublimation from the north polar cap, revealing that the released water has a representative D/H value enriched by a factor of about 7 relative to Earth's ocean [Vienna standard mean ocean water (VSMOW)]. Certain basins and orographic depressions show even higher enrichment, whereas high-altitude regions show much lower values (1 to 3 VSMOW). Our atmospheric maps indicate that water ice in the polar reservoirs is enriched in deuterium to at least 8 VSMOW, which would mean that early Mars (4.5 billion years ago) had a global equivalent water layer at least 137 meters deep.

  3. Occurrence and distribution of contaminants in bottom sediment and water of the Barron River Canal, Big Cypress National Preserve, Florida

    Science.gov (United States)

    Miller, Ronald L.; McPherson, Benjamin F.

    2001-01-01

    Trace elements and organic contaminants in bottom-sediment samples collected from 10 sites on the Barron River Canal and from one site on the Turner River in October 1998 had patterns of distribution that indicated different sources. At some sites on the Barron River Canal, lead, copper, and zinc, normalized to aluminum, exceeded limits normally considered as background and may be enriched by human activities. Polynuclear aromatic hydrocarbons and p-cresol, normalized against organic carbon, had patterns of distribution that indicated local sources of input from a road or vehicular traffic or from an old creosote wood treatment facility. Phthalate esters and the traces elements arsenic, cadmium, and zinc were more widely distributed with the highest normalized concentrations occurring at the Turner River background site, probably due to the high percentage of fine sediment (74% less than 63 micrometers) and high organic carbon concentration (42%) at that site and the binding effect of organic carbon on trace elements and trace organic compounds. Low concentrations of pesticides or pesticide degradation products were detected in bottom sediment (DDD and DDE, each less than 3.5 µg/kg) and water (9 pesticides, each less than 0.06 µ/L), primarily in the northern reach of the Barron River Canal where agriculture is a likely source. Although a few contaminants approached criteria that would indicate adverse effects on aquatic life, none exceeded the criteria, but the potential synergistic effects of mixtures of contaminants found at most sites are not included in the criteria.

  4. A Bottom-Up Approach investigating the Potential Impacts of Ethanol in Atmospheric Waters

    Science.gov (United States)

    Mead, R. N.; Taylor, A.; Shimizu, M. S.; Avery, B.; Kieber, R. J.; Willey, J. D.

    2017-12-01

    Ethanol, an emerging biofuel primarily derived from corn, can enter the atmosphere through incomplete combustion as well as natural emissions. There is a paucity of knowledge on the impacts of ethanol with other organic compounds in atmospheric waters. In this study, Guaiacol (2-methoxy phenol) was chosen as a proxy to investigate photolytic reactions with ethanol in rainwater with subsequent measurements of optical properties and chemical composition. Solutions with equimolar concentrations of guaiacol, ethanol, and hydrogen peroxide (pH 4.5 deionized water) were reacted in artificial sunlight for 6 hours. Solutions kept in the dark over this time showed no change in absorbance while solutions exposed to light (without and with ethanol) had increases in absorbance indicating formation of new chromophoric compounds. Although, little difference was observed optically and by GC/MS between solutions prepared without and with ethanol, the rate of guaiacol loss decreased with ethanol present, suggesting that ethanol could act as a radical scavenger. To simulate more polluted air masses, NaNO2 was added to each reaction mixture to observe further changes. The presence of NaNO2 led to larger increases in absorbance than in earlier experiments. No differences were observed between non-ethanol and ethanol containing solutions both optically and when run by GC-MS. Following irradiation experiments, solutions were placed in the dark and allowed to react for prolonged periods of time. After a week, solutions prepared with ethanol exhibited higher absorbance than samples without added ethanol. This was the case for trials carried out in simulated clean air masses as well as ones carried out with NaNO2.

  5. DRIVERS OF THE DYNAMICS OF DIAZOTROPHS AND DENITRIFIERS IN NORTH SEA BOTTOM WATERS AND SEDIMENTS

    Directory of Open Access Journals (Sweden)

    Lucas eStal

    2015-07-01

    Full Text Available The fixation of dinitrogen (N2 and denitrification are two opposite processes in the nitrogen cycle. The former transfers atmospheric dinitrogen gas into bound nitrogen in the biosphere, while the latter returns this bound nitrogen back to atmospheric dinitrogen. It is unclear whether or not these processes are intimately connected in any microbial ecosystem or that they are spatially and/or temporally separated. Here, we measured seafloor nitrogen fixation and denitrification as well as pelagic nitrogen fixation by using the stable isotope technique. Alongside, we measured the diversity, abundance, and activity of nitrogen-fixing and denitrifying microorganisms at three stations in the southern North Sea. Nitrogen fixation ranged from undetectable to 2.4 nmol N L-1 d-1 and from undetectable to 8.2 nmol N g-1 d-1 in the water column and seafloor, respectively. The highest rates were measured in August at Doggersbank, both for the water column and for the seafloor. Denitrification ranged from 1.7 to 208.8 µmol m-2 d-1 and the highest rates were measured in May at the Oyster Grounds. DNA sequence analysis showed sequences of nifH, a structural gene for nitrogenase, related to sequences from anaerobic sulfur/iron reducers and sulfate reducers. Sequences of the structural gene for nitrite reductase, nirS, were related to environmental clones from marine sediments. Quantitative polymerase chain reaction (qPCR data revealed the highest abundance of nifH and nirS genes at the Oyster Grounds. Quantitative reverse transcription polymerase chain reaction (qRT-PCR data revealed the highest nifH expression at Doggersbank and the highest nirS expression at the Oyster Grounds. The distribution of the diazotrophic and denitrifying communities seems to be subject to different selecting factors, leading to spatial and temporal separation of nitrogen fixation and denitrification. These selecting factors include temperature, organic matter availability, and

  6. THE INFLUENCE OF GYPSUM TREATMENT ON PHOSPHORUS RETENTION IN BOTTOM SEDIMENTS AND ON THE WATER OF MAN-MADE LAKE

    Directory of Open Access Journals (Sweden)

    Lilianna Bartoszek

    2017-01-01

    Full Text Available The paper presents a research covering the stability of phosphorus retention in the bottom sediments, resulting from application of gypsum in anoxic conditions and in slightly acidic environment (pH~5 of solutions. The present work also contains an analysis of possible effects of gypsum application for water from the reservoir, on the basis of selected parameters of overlying water. Undisturbed deposit cores extracted from two research stations on the Solina Reservoir have been a subject to a 10-weeks long exposure in determinate conditions, after application of gypsum. The conducted research indicated that retention capacities of deposits, which become increased after the use of gypsum, will decrease over time (e.g. after winter period. Application of gypsum led to a quite significant increase in concentrations of calcium in solutions. Intense release of iron from the sediments into the solutions and decrease in SO42- content, during the said 10-week exposure in anoxic conditions, indicates the use of iron (III and sulphates as electron acceptors in process of oxidization of an organic substance.

  7. The Deposition and Accumulation of Microplastics in Marine Sediments and Bottom Water from the Irish Continental Shelf.

    Science.gov (United States)

    Martin, Jake; Lusher, Amy; Thompson, Richard C; Morley, Audrey

    2017-09-07

    Microplastics are widely dispersed throughout the marine environment. An understanding of the distribution and accumulation of this form of pollution is crucial for gauging environmental risk. Presented here is the first record of plastic contamination, in the 5 mm-250 μm size range, of Irish continental shelf sediments. Sixty-two microplastics were recovered from 10 of 11 stations using box cores. 97% of recovered microplastics were found to reside shallower than 2.5 cm sediment depth, with the area of highest microplastic concentration being the water-sediment interface and top 0.5 cm of sediments (66%). Microplastics were not found deeper than 3.5 ± 0.5 cm. These findings demonstrate that microplastic contamination is ubiquitous within superficial sediments and bottom water along the western Irish continental shelf. Results highlight that cores need to be at least 4-5 cm deep to quantify the standing stock of microplastics within marine sediments. All recovered microplastics were classified as secondary microplastics as they appear to be remnants of larger items; fibres being the principal form of microplastic pollution (85%), followed by broken fragments (15%). The range of polymer types, colours and physical forms recovered suggests a variety of sources. Further research is needed to understand the mechanisms influencing microplastic transport, deposition, resuspension and subsequent interactions with biota.

  8. Depth investigation of rapid sand filters for drinking water production reveals strong stratification in nitrification biokinetic behavior

    DEFF Research Database (Denmark)

    Tatari, Karolina; Smets, Barth F.; Albrechtsen, Hans-Jørgen

    2016-01-01

    The biokinetic behavior of NH4 + removal was investigated at different depths of a rapid sand filter treating groundwater for drinking water preparation. Filter materials from the top, middle and bottom layers of a full-scale filter were exposed to various controlled NH4 + loadings in a continuous...

  9. Strong water absorption in the dayside emission spectrum of the planet HD 189733b.

    Science.gov (United States)

    Grillmair, Carl J; Burrows, Adam; Charbonneau, David; Armus, Lee; Stauffer, John; Meadows, Victoria; van Cleve, Jeffrey; von Braun, Kaspar; Levine, Deborah

    2008-12-11

    Recent observations of the extrasolar planet HD 189733b did not reveal the presence of water in the emission spectrum of the planet. Yet models of such 'hot-Jupiter' planets predict an abundance of atmospheric water vapour. Validating and constraining these models is crucial to understanding the physics and chemistry of planetary atmospheres in extreme environments. Indications of the presence of water in the atmosphere of HD 189733b have recently been found in transmission spectra, where the planet's atmosphere selectively absorbs the light of the parent star, and in broadband photometry. Here we report the detection of strong water absorption in a high-signal-to-noise, mid-infrared emission spectrum of the planet itself. We find both a strong downturn in the flux ratio below 10 microm and discrete spectral features that are characteristic of strong absorption by water vapour. The differences between these and previous observations are significant and admit the possibility that predicted planetary-scale dynamical weather structures may alter the emission spectrum over time. Models that match the observed spectrum and the broadband photometry suggest that heat redistribution from the dayside to the nightside is weak. Reconciling this with the high nightside temperature will require a better understanding of atmospheric circulation or possible additional energy sources.

  10. Application of hydrogen water chemistry to moderate corrosive circumstances around the reactor pressure vessel bottom of boiling water reactors

    International Nuclear Information System (INIS)

    Shunsuke Uchida; Eishi Ibe; Katsumi Ohsumi

    1994-01-01

    Application of hydrogen water chemistry to moderate corrosive circumstances is a promising approach to preserve structural integrities of major components and structures in the primary cooling system of BWRs. The benefits of HWC application are usually accompanied by several disadvantages. After evaluating merits and demerits of HWC application, it is concluded that optimal amounts of hydrogen injected into the feed water can moderate corrosive circumstances, in the region to be preserved, without serious disadvantages. (authors). 1 fig., 4 refs

  11. Better well control through safe drilling margin identification, influx analysis and direct bottom hole pressure control method for deep water

    Energy Technology Data Exchange (ETDEWEB)

    Veeningen, Daan [National Oilwell Varco IntelliServ (NOV), Houston, TX (United States)

    2012-07-01

    Currently, well control events are almost exclusively detected by using surface measurements. Measuring a volume increase in the 'closed loop' mud circulation system; a standpipe pressure decrease; or changes in a variety of drilling parameters provide indicators of a kick. Especially in deep water, where the riser comprises a substantial section of the well bore, early kick detection is paramount for limiting the severity of a well bore influx and improve the ability to regain well control. While downhole data is presently available from downhole tools nearby the bit, available data rates are sparse as mud pulse telemetry bandwidth is limited and well bore measurements compete with transmission of other subsurface data. Further, data transfer is one-directional, latency is significant and conditions along the string are unknown. High-bandwidth downhole data transmission system, via a wired or networked drill string system, has the unique capability to acquire real-time pressure and temperature measurement at a number of locations along the drill string. This system provides high-resolution downhole data available at very high speed, eliminating latency and restrictions that typically limit the availability of downhole data. The paper describes well control opportunities for deep water operations through the use of downhole data independent from surface measurements. First, the networked drill string provides efficient ways to identify pore pressure, fracture gradient, and true mud weight that comprise the safe drilling margin. Second, the independent measurement capability provides early kick detection and improved ability to analyze an influx even with a heterogeneous mud column through distributed along-string annular pressure measurements. Third, a methodology is proposed for a direct measurement method using downhole real-time pressure for maintaining constant bottom hole pressure during well kills in deep water. (author)

  12. Ground-water flow and ground- and surface-water interaction at McBaine Bottoms, Columbia, Missouri--2000-02

    Science.gov (United States)

    Smith, Brenda J.

    2003-01-01

    McBaine Bottoms southwest of Columbia, Missouri, is the site of 4,269 acres of the Eagle Bluffs Conservation Area operated by the Missouri Department of Conservation, about 130 acres of the city of Columbia wastewater-treat-ment wetlands, and the city of Columbia munici-pal-supply well field. The city of Columbia wastewater-treatment wetlands supply treated effluent to the Eagle Bluffs Conservation Area. The presence of a sustained ground-water high underlying the Eagle Bluffs Conservation Area has indicated that ground-water flow is toward the municipal well field that supplies drinking water to the city of Columbia. The U.S. Geological Survey, in cooperation with the Missouri Department of Conservation and the city of Columbia, measured the ground-water levels in about 88 monitoring wells and the surface-water elevation at 4 sites monthly during a 27-month period to determine the ground-water flow and the ground- and surface-water interaction at McBaine Bottoms. Lateral ground-water flow was dominated by the presence of a ground-water high that was beneath the Eagle Bluffs Conservation Area and the presence of a cone of depression in the northern part of the study area. The ground-water high was present during all months of the study. Ground-water flow was radially away from the apex of the ground-water high; west and south of the high, flow was toward the Missouri River, east of the high, flow was toward Perche Creek, and north of the high, flow was toward the north toward the city of Columbia well field. The cone of depression was centered around the city of Columbia well field. Another permanent feature on the water-level maps was a ground-water high beneath treatment wetland unit 1. Although the ground-water high beneath the Eagle Bluffs Conservation Area was present throughout the study period, the configuration of the high changed depending on hydrologic conditions. Generally in the spring, the height of the ground-water high began to decrease and hydraulic

  13. Spatial distribution and environmental geochemistry of zinc metal in water and surficial bottom sediments of Lagoon Burullus, Egypt.

    Science.gov (United States)

    El-Badry, Abd El-Monsef Ahmed; El-Kammar, Ahmad Mohamed

    2018-02-01

    Lagoon Burullus is located in the North West quadrant of the Nile Delta. It receives drainage water through several drains around the lagoon. Understanding the mobility and bioavailability of zinc metal in bottom sediments of Lagoon Burullus is essential for the design of remediation processes and the institution of environmental recommendation for zinc pollution. Single extractions used to fractionate zinc into five fractions. The chemical analyses preceded using atomic absorption spectrometry after using the digestion technique. Zinc concentrates in the residual fraction (167.5μg/g) followed by the organic (14.6μg/g), exchangeable (3.2μg/g), carbonate (2.4μg/g) and then the Fe-Mn hydroxides (1μg/g) fractions. The average content of zinc (189μg/g) is about three fold the average earth's crust. Ecological pollution index show that the metal has a low-risk assessment to surrounding ecosystem. The anthropogenic activities considered as the main source of pollution. Copyright © 2017. Published by Elsevier Ltd.

  14. Occurence of antibiotic compounds found in the water column and bottom sediments from a stream receiving two waste water treatment plant effluents in northern New Jersey, 2008

    Science.gov (United States)

    Gibs, Jacob; Heckathorn, Heather A.; Meyer, Michael T.; Klapinski, Frank R.; Alebus, Marzooq; Lippincott, Robert

    2013-01-01

    An urban watershed in northern New Jersey was studied to determine the presence of four classes of antibiotic compounds (macrolides, fluoroquinolones, sulfonamides, and tetracyclines) and six degradates in the water column and bottom sediments upstream and downstream from the discharges of two wastewater treatment plants (WWTPs) and a drinking-water intake (DWI). Many antibiotic compounds in the four classes not removed by conventional WWTPs enter receiving waters and partition to stream sediments. Samples were collected at nine sampling locations on 2 days in September 2008. Two of the nine sampling locations were background sites upstream from two WWTP discharges on Hohokus Brook. Another background site was located upstream from a DWI on the Saddle River above the confluence with Hohokus Brook. Because there is a weir downstream of the confluence of Hohokus Brook and Saddle River, the DWI receives water from Hohokus Brook at low stream flows. Eight antibiotic compounds (azithromycin (maximum concentration 0.24 μg/L), ciprofloxacin (0.08 μg/L), enrofloxacin (0.015 μg/L), erythromycin (0.024 μg/L), ofloxacin (0.92 μg/L), sulfamethazine (0.018 μg/L), sulfamethoxazole (0.25 μg/L), and trimethoprim (0.14 μg/L)) and a degradate (erythromycin-H2O (0.84 μg/L)) were detected in the water samples from the sites downstream from the WWTP discharges. The concentrations of six of the eight detected compounds and the detected degradate compound decreased with increasing distance downstream from the WWTP discharges. Azithromycin, ciprofloxacin, ofloxacin, and trimethoprim were detected in stream-bottom sediments. The concentrations of three of the four compounds detected in sediments were highest at a sampling site located downstream from the WWTP discharges. Trimethoprim was detected in the sediments from a background site. Pseudo-partition coefficients normalized for streambed sediment organic carbon concentration were calculated for azithromycin, ciprofloxacin, and

  15. Investigation of the complexation of metal-ions by strong ligands in fresh and marine water.

    Science.gov (United States)

    Pesavento, Maria; Biesuz, Raffaela; Profumo, Antonella; Soldi, Teresa

    2003-01-01

    The detection and investigation of metal ions bound in strong complexes in natural waters is a difficult task, due to low concentration of the metal ions themselves, and also of the strong ligands, which, moreover, are often not of a well-defined composition. Here, a method is proposed for the investigation of the speciation of metal ions in natural waters. It is based on the sorption of metal ions on strongly sorbing ion exchange resins, i.e. complexing resins. For this reason the method is called Resin Titration. It has been shown in previous investigations that the concentration of metal ion totally sorbed by a particular resin, and its reaction coefficient in the solution phase in the presence of the resin, can be determined from the sorption data using a simple relationship. Here, a data treatment (the Ruzic linearization method) is proposed for also determining the concentration of the ligands responsible for the complex in equilibrium with the resin. The method was applied to data obtained by Resin Titration of a freshwater and a seawater. Copper(II) and aluminium(III) were considered, using Chelex 100 as a titrant, due to its strong sorbing properties towards these metal ions. The results were: the total metal concentration in equilibrium with the resin, the side reaction coefficients, and the concentration of ligands. In all these cases the ligands forming very strong complexes were found to be at concentration lower than that of the metals. The Ruzic linearization method allows the determination of the concentration of the ligands forming very strong complexes in equilibrium with Chelex 100. The reaction coefficient was better determined by the calculation method previously proposed for RT. The ligands responsible for the strong complexes were found to be at low concentration, often lower than that of the metal ions considered. The metal in the original sample is partly bound to these ligands, since the complexes are very strong. Only a part of the metal

  16. Lake Worth bottom sediments : A chronicle of water-quality changes in western Fort Worth, Texas, 1914-2001

    Science.gov (United States)

    Braun, Christopher L.; Harwell, Glenn R.

    2004-01-01

    In spring 2000, the Texas Department of Health issued a fish-consumption advisory for Lake Worth, Tex., because of elevated concentrations of polychlorinated biphenyls (PCBs) in fish (Texas Department of Health, 2000). In response to the advisory and in cooperation with the U.S. Air Force, the U.S. Geological Survey (USGS) collected 21 surficial samples and three deeper gravity core samples from the sediment deposited at the bottom of Lake Worth. The purpose of that study was to assess the spatial distribution and historical trends of selected hydrophobic contaminants, including PCBs, and to determine, to the extent possible, sources of selected metals and hydrophobic organic contaminants (HOCs) to Lake Worth. Hydrophobic (literally “water fearing”) contaminants tend to chemically adsorb to soils and sediments. Fifteen of the top 20 contaminants on the Agency for Toxic Substances and Disease Registry (2001) priority list of hazardous substances are hydrophobic. Chemical analysis of sediment cores is one method that can be used to determine trends in HOCs such as PCBs. As sediments accumulate in lakes and reservoirs, they generate a partial historical record of water quality. This fact sheet describes the collection of sediment cores, age-dating methods, and historical trends in PCBs in Lake Worth sediments. The fact sheet also describes the spatial distribution of PCBs in surficial sediments and concludes with objectives for the second phase of data collection and the approach that will be used to achieve these objectives. The USGS published a comprehensive report on the first phase of the study (Harwell and others, 2003). Lake Worth is a reservoir on the West Fork Trinity River on the western edge of Fort Worth in Tarrant County. In 1914, the City of Fort Worth completed the reservoir to serve as a municipal water supply. Lake Worth has a surface area of 13.2 square kilometers and a storage capacity of 47 million cubic meters. The drainage area to the

  17. Nitrogen and water inputs to tomato plant do not trigger bottom-up effects on a leafminer parasitoid through host and non-host exposures.

    Science.gov (United States)

    Dong, Yong-Cheng; Han, Peng; Niu, Chang-Ying; Zappalà, Lucia; Amiens-Desneux, Edwige; Bearez, Philippe; Lavoir, Anne-Violette; Biondi, Antonio; Desneux, Nicolas

    2018-03-01

    Bottom-up and top-down forces are major components of biological control against pests in an agro-ecosystem. Understanding the multi-trophic interactions between plants and secondary consumers would help optimize pest control strategies. We manipulated nitrogen and/or water inputs to tomato plants (Solanum lycopersicum) to test whether these manipulations could trigger bottom-up effects on the parasitoid Necremnus tutae via host (Tuta absoluta) and/or non-host (Bemisia tabaci) exposures, and compared the control efficacy of N. tutae on T. absoluta in the presence and absence of B. tabaci. The results showed no cascading effects of plant nitrogen and/or water inputs on N. tutae via either host or non-host exposure. The bottom-up force was mitigated by chewing or sap-feeding insect consumers at the second energy level. By contrast, the top-down force on T. absoluta from parasitoids was enhanced by an additionally provided non-host, which could produce alternative food sources extending N. tutae longevity and enhancing the fitness of its offspring. Our results provided evidence for the combination of bottom-up and top-down approaches in tomato integrated pest management programs. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  18. Research on the degradation mechanism of dimethyl phthalate in drinking water by strong ionization discharge

    Science.gov (United States)

    Hong, ZHAO; Chengwu, YI; Rongjie, YI; Huijuan, WANG; Lanlan, YIN; I, N. MUHAMMAD; Zhongfei, MA

    2018-03-01

    The degradation mechanism of dimethyl phthalate (DMP) in the drinking water was investigated using strong ionization discharge technology in this study. Under the optimized condition, the degradation efficiency of DMP in drinking water was up to 93% in 60 min. A series of analytical techniques including high-performance liquid chromatography, liquid chromatography mass spectrometry, total organic carbon analyzer and ultraviolet-visible spectroscopy were used in the study. It was found that a high concentration of ozone (O3) produced by dielectric barrier discharge reactor was up to 74.4 mg l-1 within 60 min. Tert-butanol, isopropyl alcohol, carbonate ions ({{{{CO}}}3}2-) and bicarbonate ions ({{{{HCO}}}3}-) was added to the sample solution to indirectly prove the presence and effect of hydroxyl radicals (·OH). These analytical findings indicate that mono-methyl phthalate, phthalic acid (PA) and methyl ester PA were detected as the major intermediates in the process of DMP degradation. Finally, DMP and all products were mineralized into carbon dioxide (CO2) and water (H2O) ultimately. Based on these analysis results, the degradation pathway of DMP by strong ionization discharge technology were proposed.

  19. Wood Nanotechnology for Strong, Mesoporous, and Hydrophobic Biocomposites for Selective Separation of Oil/Water Mixtures.

    Science.gov (United States)

    Fu, Qiliang; Ansari, Farhan; Zhou, Qi; Berglund, Lars A

    2018-03-27

    Tremendous efforts have been dedicated to developing effective and eco-friendly approaches for separation of oil-water mixtures. Challenges remain in terms of complex processing, high material cost, low efficiency, and scale-up problems. Inspired by the tubular porosity and hierarchical organization of wood, a strong, mesoporous, and hydrophobic three-dimensional wood structure is created for selective oil/water separation. A delignified wood template with hydrophilic characteristics is obtained by removal of lignin. The delignified wood template is further functionalized by a reactive epoxy-amine system. This wood/epoxy biocomposite reveals hydrophobic/oleophilic functionality and shows oil absorption as high as 15 g/g. The wood/epoxy biocomposite has a compression yield strength and modulus up to 18 and 263 MPa, respectively, at a solid volume fraction of only 12%. This is more than 20 times that of cellulose-based foams/aerogels reconstructed from cellulose nanofibrils. The favorable performance is ascribed to the natural hierarchical honeycomb structure of wood. Oil can be selectively absorbed not only from below but also from above the water surface. High oil/water absorption capacity of both types of wood structures (delignified template and polymer-modified biocomposite) allows for applications in oil/water separation.

  20. Collision-Induced Melting in Collisions of Water Ice Nanograins: Strong Deformations and Prevention of Bouncing

    Science.gov (United States)

    Nietiadi, Maureen L.; Umstätter, Philipp; Alabd Alhafez, Iyad; Rosandi, Yudi; Bringa, Eduardo M.; Urbassek, Herbert M.

    2017-11-01

    Collisions between ice grains are ubiquitous in the outer solar system. The mechanics of such collisions is traditionally described by the elastic contact theory of adhesive spheres. Here we use molecular dynamics simulations to study collisions between nanometer-sized amorphous water ice grains. We demonstrate that the collision-induced heating leads to grain melting in the interface of the colliding grains. The large lateral deformations and grain sticking induced considerably modify available macroscopic collision models. We report on systematic increases of the contact radius, strong grain deformations, and the prevention of grain bouncing.

  1. Triple bottom line assessment of raw water treatment: methodology and application to a case study in the municipality of Oppegård in south-eastern Norway.

    Science.gov (United States)

    Venkatesh, G; Azrague, Kamal; Bell, Stig; Eikebrokk, Bjørnar

    2015-01-01

    There could be several options a water treatment plant (WTP) can select from, if an improvement in treated water quality (WQ) is desired. This paper outlines a methodology to test a variety of approaches to accomplish pre-set goals as regards WQ, while adopting a triple bottom line approach. This approach, in a nutshell, takes into consideration economic, environmental and social aspects in decision-making. The methodology has been applied to the Stangasen WTP in the town of Oppegård in south-eastern Norway. Among the seven alternative approaches compared were the use, as coagulant, of five different dosages of granulated aluminium sulphate, liquid aluminium sulphate (48%) and liquid ferric chloride (40%). Using the set of weighting factors obtained from experts, it was determined that increasing the dosage of granulated aluminium sulphate by 20% over the current one would be the most sustainable option from a triple bottom line point of view.

  2. Climate variability and demand growth as drivers of water scarcity in the Turkwel river basin: a bottom-up risk assessment of a data-sparse basin in Kenya

    Science.gov (United States)

    Hirpa, F. A.; Dyer, E.; Hope, R.; Dadson, S. J.

    2017-12-01

    Sustainable water management and allocation are essential for maintaining human well-being, sustaining healthy ecosystems, and supporting steady economic growth. The Turkwel river basin, located in north-western Kenya, experiences a high level of water scarcity due to its arid climate, high rainfall variability, and rapidly growing water demand. However, due to sparse hydro-climatic data and limited literature, the water resources system of the basin has been poorly understood. Here we apply a bottom-up climate risk assessment method to estimate the resilience of the basin's water resources system to growing demand and climate stressors. First, using a water resource system model and historical climate data, we construct a climate risk map that depicts the way in which the system responds to climate change and variability. Then we develop a set of water demand scenarios to identify the conditions that potentially lead to the risk of unmet water demand and groundwater depletion. Finally, we investigate the impact of climate change and variability by stress testing these development scenarios against historically strong El Niño/Southern Oscillation (ENSO) years and future climate projections from multiple Global Circulation Models (GCMs). The results reveal that climate variability and increased water demand are the main drivers of water scarcity in the basin. Our findings show that increases in water demand due to expanded irrigation and population growth exert the strongest influence on the ability of the system to meet water resource supply requirements, and in all cases considered increase the impacts of droughts caused by future climate variability. Our analysis illustrates the importance of combining analysis of future climate risks with other development decisions that affect water resources planning. Policy and investment decisions which maximise water use efficiency in the present day are likely to impart resilience to climate change and variability under a

  3. Governing for Integrated Water and Flood Risk Management: Comparing Top-Down and Bottom-Up Approaches in Spain and California

    OpenAIRE

    Anna Serra-Llobet; Esther Conrad; Kathleen Schaefer

    2016-01-01

    Flood risk management in the context of Integrated Water Resource Management (IWRM) is becoming widely accepted as an approach to improving resilience in light of increasing flood risks due to climate change and other factors. This paper contributes to a better understanding of the governance arrangements needed for effectively implement integrated approaches to managing flood risk. We compare how IWRM and flood risk management have been operationalized within “top-down” and “bottom-up” gover...

  4. Diurnal behavior of the carbon dioxide flux and change in the isotopic ratio δ13C in surface and near-bottom water in littoral of Lake Baikal

    Science.gov (United States)

    Panchenko, Mikhail V.; Domysheva, Valentina M.; Padalko, Natalia L.; Chernikov, Eugenii V.; Prazdnichnykh, Maxim I.; Tumakov, Alexander G.; Pestunov, Dmitrii A.

    2014-11-01

    Lake Baikal is one of the unique natural environments in Siberia which, to a large extent, affects the state of the nature in this region. The processes of gas exchange in the "water-atmosphere" system have been studied in Lake Baikal since 2002. The main purpose of the integrated investigations of exchange of carbon-containing gases in the water-atmosphere system in Lake Baikal is to study the contribution of physical, chemical, and biological components of the process and their interrelation with the intensity and rhythms of the fluxes. In 2013, the integrated measurements in the littoral area of Baikal were complemented with studies of the diurnal dynamics of isotopic ratio δ 13C in the surface and near-bottom water, which were not yet performed in Baikal before. In this work, we analyze first results of the joint analysis of RO2 fluxes in the "atmosphere - water surface" system and δ 13C, obtained in August 2013 in the littoral area of South Baikal. It is shown that d13C markedly increases in the surface waters at daylight time. In nighttime period, there takes place a reverse process, when δ 13C of the surface water approaches δ 13C, which is recorded for near-bottom water.

  5. Antarctic Bottom Water from the Adélie and George V Land coast, East Antarctica (140-149°E)

    Science.gov (United States)

    Williams, G. D.; Aoki, S.; Jacobs, S. S.; Rintoul, S. R.; Tamura, T.; Bindoff, N. L.

    2010-04-01

    We report on observations of dense shelf water overflows and Antarctic Bottom Water (AABW) formation along the continental margin of the Adélie and George V Land coast between 140°E and 149°E. Vertical sections and bottom layer water mass properties sampled during two RVIB Nathaniel B Palmer hydrographic surveys (NBP00-08, December 2000/January 2001 and NBP04-08, October 2004) describe the spreading of cold, dense shelf water on the continental slope and rise from two independent source regions. The primary source region is the Adélie Depression, exporting high-salinity dense shelf water through the Adélie Sill at 143°E. An additional eastern source region of lower-salinity dense shelf water from the Mertz Depression is identified for the first time from bottom layer properties northwest of the Mertz Sill and Mertz Bank (146°E-148°E) that extend as far as the Buffon Channel (144.75°E) in summer. Regional analysis of satellite-derived ice production estimates over the entire region from 1992 to 2005 suggests that up to 40% of the total ice production for the region occurs over the Mertz Depression and therefore this area is likely to make a significant contribution to the total dense shelf water export. Concurrent time series from bottom-mounted Microcats and ADCP instruments from the Mertz Polynya Experiment (April 1998 to May 1999) near the Adélie Sill and on the upper continental slope (1150 m) and lower continental rise (3250 m) to the north describe the seasonal variability in downslope events and their interaction with the ambient water masses. The critical density for shelf water to produce AABW is examined and found to be 27.85 kg m-3 from the Adélie Depression and as low as 27.80 kg m-3 from the Mertz Depression. This study suggests previous dense shelf water export estimates based on the flow through the Adélie Sill alone are conservative and that other regions around East Antarctica with similar ice production to the Mertz Depression could be

  6. Reconnaissance investigation of water quality, bottom sediment, and biota associated with irrigation drainage in and near Stillwater Wildlife Management Area, Churchill County, Nevada, 1986-87

    International Nuclear Information System (INIS)

    Hoffman, R.J.; Hallock, R.J.; Rowe, T.G.; Lico, M.S.; Burge, H.L.

    1990-01-01

    An investigation was initiated to determine whether irrigation drainage in and near the Stillwater Wildlife Management Area has caused or has potential to cause harmful effects on human health or fish and wildlife, or may adversely affect the suitability of water for beneficial uses. Samples of surface and groundwater, bottom sediment, and biota were collected from sites upstream and downstream from the Fallon agricultural area in the Carson Desert and were analyzed for potentially toxic trace elements, including selenium. Other analyses included radioactive substances, major dissolved constituents, and nutrients in water, and pesticide residues in bottom sediments and biota. In areas affected by irrigation drainage, concentrations of the following constituents commonly were found to exceed baseline concentrations or federal and state criteria for the protection of aquatic life or the propagation of wildlife: in water, arsenic, boron, dissolved solids, sodium, and un-ionized ammonia; in bottom sediments, arsenic, lithium, mercury, molybdenum, and selenium; and in biota, arsenic, boron, chromium, copper, mercury, selenium, and zinc. In some wetlands, selenium and mercury appear to be biomagnified whereas arsenic is bioaccumulated. Some radioactive substances were substantially higher at the downstream sites compared with upstream background sites, but the significance of this to wildlife is unknown at present. 88 refs., 32 figs., 19 tabs

  7. Water-wave diffraction and radiation by multiple three-dimensional bodies over a mild-slope bottom

    DEFF Research Database (Denmark)

    Ruiz, Pau Mercadé; Ferri, Francesco; Kofoed, Jens Peter

    2017-01-01

    Highlights •A tool to model wave diffraction and radiation in mild-slope bottoms is proposed. •The tool combines a mild-slope equation model with diffraction transfer matrices. •The tool predictions are verified against analytical solutions for two test problems.......Highlights •A tool to model wave diffraction and radiation in mild-slope bottoms is proposed. •The tool combines a mild-slope equation model with diffraction transfer matrices. •The tool predictions are verified against analytical solutions for two test problems....

  8. Bottom production

    Energy Technology Data Exchange (ETDEWEB)

    Baines, J.; Baranov, S.P.; Bartalini, P.; Bay, A.; Bouhova, E.; Cacciari, M.; Caner, A.; Coadou, Y.; Corti, G.; Damet, J.; Dell-Orso, R.; De Mello Neto, J.R.T.; Domenech, J.L.; Drollinger, V.; Eerola, P.; Ellis, N.; Epp, B.; Frixione, S.; Gadomski, S.; Gavrilenko, I.; Gennai, S.; George, S.; Ghete, V.M.; Guy, L.; Hasegawa, Y.; Iengo, P.; Jacholkowska, A.; Jones, R.; Kharchilava, A.; Kneringer, E.; Koppenburg, P.; Korsmo, H.; Kramer, M.; Labanca, N.; Lehto, M.; Maltoni, F.; Mangano, M.L.; Mele, S.; Nairz, A.M.; Nakada, T.; Nikitin, N.; Nisati, A.; Norrbin, E.; Palla, F.; Rizatdinova, F.; Robins, S.; Rousseau, D.; Sanchis-Lozano, M.A.; Shapiro, M.; Sherwood, P.; Smirnova, L.; Smizanska, M.; Starodumov, A.; Stepanov, N.; Vogt, R.

    2000-03-15

    In the context of the LHC experiments, the physics of bottom flavoured hadrons enters in different contexts. It can be used for QCD tests, it affects the possibilities of B decays studies, and it is an important source of background for several processes of interest. The physics of b production at hadron colliders has a rather long story, dating back to its first observation in the UA1 experiment. Subsequently, b production has been studied at the Tevatron. Besides the transverse momentum spectrum of a single b, it has also become possible, in recent time, to study correlations in the production characteristics of the b and the b. At the LHC new opportunities will be offered by the high statistics and the high energy reach. One expects to be able to study the transverse momentum spectrum at higher transverse momenta, and also to exploit the large statistics to perform more accurate studies of correlations.

  9. Bottom Production

    CERN Document Server

    Nason, P.; Schneider, O.; Tartarelli, G.F.; Vikas, P.; Baines, J.; Baranov, S.P.; Bartalini, P.; Bay, A.; Bouhova, E.; Cacciari, M.; Caner, A.; Coadou, Y.; Corti, G.; Damet, J.; Dell'Orso, R.; De Mello Neto, J.R.T.; Domenech, J.L.; Drollinger, V.; Eerola, P.; Ellis, N.; Epp, B.; Frixione, S.; Gadomski, S.; Gavrilenko, I.; Gennai, S.; George, S.; Ghete, V.M.; Guy, L.; Hasegawa, Y.; Iengo, P.; Jacholkowska, A.; Jones, R.; Kharchilava, A.; Kneringer, E.; Koppenburg, P.; Korsmo, H.; Kramer, M.; Labanca, N.; Lehto, M.; Maltoni, F.; Mangano, Michelangelo L.; Mele, S.; Nairz, A.M.; Nakada, T.; Nikitin, N.; Nisati, A.; Norrbin, E.; Palla, F.; Rizatdinova, F.; Robins, S.; Rousseau, D.; Sanchis-Lozano, M.A.; Shapiro, M.; Sherwood, P.; Smirnova, L.; Smizanska, M.; Starodumov, A.; Stepanov, N.; Vogt, R.

    2000-01-01

    We review the prospects for bottom production physics at the LHC. Members of the working group who has contributed to this document are: J. Baines, S.P. Baranov, P. Bartalini, A. Bay, E. Bouhova, M. Cacciari, A. Caner, Y. Coadou, G. Corti, J. Damet, R. Dell'Orso, J.R.T. De Mello Neto, J.L. Domenech, V. Drollinger, P. Eerola, N. Ellis, B. Epp, S. Frixione, S. Gadomski, I. Gavrilenko, S. Gennai, S. George, V.M. Ghete, L. Guy, Y. Hasegawa, P. Iengo, A. Jacholkowska, R. Jones, A. Kharchilava, E. Kneringer, P. Koppenburg, H. Korsmo, M. Kraemer, N. Labanca, M. Lehto, F. Maltoni, M.L. Mangano, S. Mele, A.M. Nairz, T. Nakada, N. Nikitin, A. Nisati, E. Norrbin, F. Palla, F. Rizatdinova, S. Robins, D. Rousseau, M.A. Sanchis-Lozano, M. Shapiro, P. Sherwood, L. Smirnova, M. Smizanska, A. Starodumov, N. Stepanov, R. Vogt

  10. Strongly Coupled Molybdenum Carbide on Carbon Sheets as a Bifunctional Electrocatalyst for Overall Water Splitting.

    Science.gov (United States)

    Wang, Hao; Cao, Yingjie; Sun, Cheng; Zou, Guifu; Huang, Jianwen; Kuai, Xiaoxiao; Zhao, Jianqing; Gao, Lijun

    2017-09-22

    High-performance and affordable electrocatalysts from earth-abundant elements are desirably pursued for water splitting involving hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). Here, a bifunctional electrocatalyst of highly crystalline Mo 2 C nanoparticles supported on carbon sheets (Mo 2 C/CS) was designed toward overall water splitting. Owing to the highly active catalytic nature of Mo 2 C nanoparticles, the high surface area of carbon sheets and efficient charge transfer in the strongly coupled composite, the designed catalysts show excellent bifunctional behavior with an onset potential of -60 mV for HER and an overpotential of 320 mV to achieve a current density of 10 mA cm -2 for OER in 1 m KOH while maintaining robust stability. Moreover, the electrolysis cell using the catalyst only requires a low cell voltage of 1.73 V to achieve a current density of 10 mA cm -2 and maintains the activity for more than 100 h when employing the Mo 2 C/CS catalyst as both anode and cathode electrodes. Such high performance makes Mo 2 C/CS a promising electrocatalyst for practical hydrogen production from water splitting. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Up-going Red Water in the Ice at the Bottom of the World: Picture Taking Boxes and Listening Boxes Tell Us How and Why

    Science.gov (United States)

    Carr, C. G.; Pettit, E. C.

    2017-12-01

    Blood Falls is a place where red water comes out from under ice to the top of the ice and makes a strange red water fall. This ice is part of the big ice at the bottom of the world. The red water only comes out at some times and not every year, but it always comes out at the same place. The red water is important because it has tiny tiny not-animal life that tells us how life could be on other worlds. Knowing about the ice and red water is important because this ice is cold, colder than other ice in other places, and we want to know how water can get through. We didn't know why the red water comes up from under the ice when it does or how. We wanted to understand how the ice breaks and we watched the ice by taking pictures all year to see when the red water comes out. We found out that in the cold part of one year, the red water came out even though the air was not warm enough for water to be water! We think the red water comes out because the red water is blocked under the heavy ice and gets pushed tight. In the cold part of the year, cracks break down from the air into the ice and other cracks break up from under the ice because the red water is so pushed. The cracks from the top and bottom of the ice join, and the red water comes out. We used listening boxes that can feel how the ground moves to understand that the ice is breaking at the bottom and we can see that it breaks at the top of the ice. The red water can stay water and not ice inside the big ice because the red water has tiny pieces of the same stuff that can turn ice into water on the roads. If the ice breaks in the cold time, no water can get in from the top of the ice, so the red water under the ice stays clean from the air water. If the ice breaks in the warm time of year, water could get in from the top of the ice and make the red water under the ice not clean from the air. Since we saw in our pictures that the red water came out in the cold time of year, this means the red water could stay clean

  12. Statistical comparison of leaching behavior of incineration bottom ash using seawater and deionized water: Significant findings based on several leaching methods.

    Science.gov (United States)

    Yin, Ke; Dou, Xiaomin; Ren, Fei; Chan, Wei-Ping; Chang, Victor Wei-Chung

    2018-02-15

    Bottom ashes generated from municipal solid waste incineration have gained increasing popularity as alternative construction materials, however, they contains elevated heavy metals posing a challenge for its free usage. Different leaching methods are developed to quantify leaching potential of incineration bottom ashes meanwhile guide its environmentally friendly application. Yet, there are diverse IBA applications while the in situ environment is always complicated, challenging its legislation. In this study, leaching tests were conveyed using batch and column leaching methods with seawater as opposed to deionized water, to unveil the metal leaching potential of IBA subjected to salty environment, which is commonly encountered when using IBA in land reclamation yet not well understood. Statistical analysis for different leaching methods suggested disparate performance between seawater and deionized water primarily ascribed to ionic strength. Impacts of leachant are metal-specific dependent on leaching methods and have a function of intrinsic characteristics of incineration bottom ashes. Leaching performances were further compared on additional perspectives, e.g. leaching approach and liquid to solid ratio, indicating sophisticated leaching potentials dominated by combined geochemistry. It is necessary to develop application-oriented leaching methods with corresponding leaching criteria to preclude discriminations between different applications, e.g., terrestrial applications vs. land reclamation. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Preliminary Examination of the System Fly Ash-Bottom Ash-Flue Gas Desulphurization Gypsum-Portland Cement-Water for Road Construction

    Directory of Open Access Journals (Sweden)

    R. Tokalic

    2013-01-01

    Full Text Available This paper describes an investigation into the use of three power plant wastes: fly ash, flue gas desulphurization gypsum, and bottom ash for subbase layers in road construction. Two kinds of mixtures of these wastes with Portland cement and water were made: first with fly ash consisting of coarser particles (<1.651 mm and second with fly ash consisting of smaller particles (<0.42 mm. The mass ratio of fly ash-Portland cement-flue gas desulphurization gypsum-bottom ash was the same (3 : 1 : 1 : 5 in both mixtures. For both mixtures, the compressive strength, the mineralogical composition, and the leaching characteristics were determined at different times, 7 and 28 days, after preparation. The obtained results showed that both mixtures could find a potential use for subbase layers in road construction.

  14. Watershed trend analysis and water-quality assessment using bottom-sediment cores from Cheney Reservoir, south-central Kansas

    Science.gov (United States)

    Pope, Larry M.

    1998-01-01

    An examination of Cheney Reservoir bottom sediment was conducted in August 1997 to describe long-term trends and document the occurrence of selected constituents at concentrations that may be detrimental to aquatic organisms. Average concentrations of total phosphorus in bottom-sediment cores ranged from 94 to 674 milligrams per kilogram and were statistically related to silt- and (or) clay-size particles. Results from selected sampling sites in Cheney Reservoir indicate an increasing trend in total phosphorus concentrations. This trend is probably of nonpoint-source origin and may be related to an increase in fertilizer sales in the area, which more than doubled between 1965 and 1996, and to livestock production. Few organochlorine compounds were detected in bottom-sediment samples from Cheney Reservoir. DDT, its degradation products DDD and DDE, and dieldrin had detectable concentrations in the seven samples that were analyzed. DDT and DDD were each detected in one sample at concentrations of 1.0 and 0.65 microgram per kilogram, respectively. By far, the most frequently detected organochlorine insecticide was DDE, which was detected in all seven samples, ranging in concentration from 0.31 to 1.3 micrograms per kilogram. A decreasing trend in DDE concentrations was evident in sediment-core data from one sampling site. Dieldrin was detected in one sample from each of two sampling sites at concentrations of 0.21 and 0.22 micrograms per kilogram. Polychlorinated biphenyls were not detected in any bottom-sediment sample analyzed. Selected organophosphate, chlorophenoxy-acid, triazine, and acetanilide pesticides were analyzed in 18 bottom-sediment samples. Of the 23 pesticides analyzed, only the acetanilide herbicide metolachlor was detected (in 22 percent of the samples). Seven bottom-sediment samples were analyzed for major metals and trace elements. The median and maximum concentrations of arsenic and chromium, the maximum concentration of copper, and all

  15. Magnetic separation technique for environmental water purification by strong magnetic field generator loading HTS bulk magnets

    International Nuclear Information System (INIS)

    Oka, T.; Tanaka, K.; Kimura, T.; Mimura, D.; Fukui, S.; Ogawa, J.; Sato, T.; Ooizumi, M.; Yokoyama, K.; Yamaguchi, M.

    2010-01-01

    The magnetic separation technique in combination with high temperature superconducting bulk magnets has been investigated to purify the ground water which has been used in the coolant system for the incinerator furnace to cool the burning gas. The experiment has been operated by means of the newly-built alternating channel type magnetic separating device. The separation ratios of ferromagnetic flocks including fine magnetite powder have been estimated by means of the high gradient magnetic separation method with small iron balls filled in the water channels. As the magnetic force acting on the magnetic particle is given by the product of a magnetization of the material and a gradient of magnetic field, and as the ferromagnetic stainless steel balls yield the steep gradient of magnetic field around them in a strong magnetic field, the system has exhibited a quite excellent performance with respect to the separation ratios. The separation ratios of the flocks which contain the magnetite powder with the values more than 50 ppm have remained over 80% for under the flow rates less than 5 L/min.

  16. Magnetic separation technique for environmental water purification by strong magnetic field generator loading HTS bulk magnets

    Science.gov (United States)

    Oka, T.; Tanaka, K.; Kimura, T.; Mimura, D.; Fukui, S.; Ogawa, J.; Sato, T.; Ooizumi, M.; Yokoyama, K.; Yamaguchi, M.

    2010-11-01

    The magnetic separation technique in combination with high temperature superconducting bulk magnets has been investigated to purify the ground water which has been used in the coolant system for the incinerator furnace to cool the burning gas. The experiment has been operated by means of the newly-built alternating channel type magnetic separating device. The separation ratios of ferromagnetic flocks including fine magnetite powder have been estimated by means of the high gradient magnetic separation method with small iron balls filled in the water channels. As the magnetic force acting on the magnetic particle is given by the product of a magnetization of the material and a gradient of magnetic field, and as the ferromagnetic stainless steel balls yield the steep gradient of magnetic field around them in a strong magnetic field, the system has exhibited a quite excellent performance with respect to the separation ratios. The separation ratios of the flocks which contain the magnetite powder with the values more than 50 ppm have remained over 80% for under the flow rates less than 5 L/min.

  17. Seasonality of bottom water temperature in the northern North Sea reconstructed from the oxygen isotope composition of the bivalve Arctica islandica

    Science.gov (United States)

    Trofimova, Tamara; Andersson, Carin; Bonitz, Fabian

    2017-04-01

    The seasonality of temperature changes is an important characteristic of climate. However, observational data for the ocean are only available for the last 150 year from a limited number of locations. Prior to 18th century information is only available from proxy reconstructions. The vast majority of such reconstructions depend on land-based archives, primarily from dendrochronology. Established marine proxy records for the ocean, especially at high latitudes, are both sparsely distributed and poorly resolved in time. Therefore, the identification and development of proxies for studying key ocean processes at sub-annual resolution that can extend the marine instrumental record is a clear priority in marine climate science. In this study, we have developed a record of early Holocene seasonal variability of bottom water temperature from the Viking Bank in the northern most North Sea. This area is of a particular interest since the hydrography is controlled by the inflow of Atlantic water. The reconstruction is based on the oxygen isotope composition of the growth increments in two sub-fossil shells of Arctica islandica (Bivalvia), dated to 9600-9335 cal. yr BP. By combining radiocarbon dating and sclerochronological techniques a floating chronology spanning over 200 years was constructed. Using the chronology as an age model, oxygen isotope measurements from 2 shells were combined into a 22-years long record. The results from this oxygen isotope record are compared with stable oxygen isotope profiles from modern shells to estimate changes in the mean state and seasonality between present and early Holocene. Shell-derived oxygen isotope values together with ice-volume corrected oxygen isotope values for the seawater were used to calculate bottom-water temperatures on a sub-annual time-scale. Preliminary results of the reconstructed early Holocene bottom water temperature indicate higher seasonality and lower minimum temperature compared to the present.

  18. Resurvey of quality of surface water and bottom material of the Barataria Preserve of Jean Lafitte National Historical Park and Preserve, Louisiana, 1999-2000

    Science.gov (United States)

    Swarzenski, Christopher M.

    2003-01-01

    The quality of water and bottom material in the Barataria Preserve of Jean Lafitte National Historical Park and Preserve, Louisiana, was surveyed from March 1999 to May 2000. Organochlorine, chlorophenoxy acid, and organophosphorus pesticides; polychlorinated biphenyls (PCB?s); and trace elements were analyzed in surface water and bottom material from three sites previously sampled in a 1981-82 survey. Surface water at six sites was sampled and analyzed for selected nutrients and major inorganic ions based on their importance to human health, the health of the marshes of the Barataria Preserve, or their usefulness in tracking the circulation of Mississippi River water in the Barataria Preserve. Southern Louisiana was in a moderate to severe drought during most of the sampling period, which elevated salinity in the Barataria Preserve for at least 8 months. Specific conductance values were less than 3,000 ?S/cm (microsiemens per centimeter at 25 degrees Celsius) in surface water throughout the Barataria Preserve from March through September 1999. Specific conductance values increased over the next 2 months and then remained between 5,000 and 6,000 ?S/cm. The herbicide 2,4-D was detected in water at the two sites sampled in August 1999 but not at any site during the two other sampling times. Iron, manganese, and the trace elements copper, nickel, and zinc were detected in dissolved and whole-water samples at all three sites. Nitrite+ nitrate, as nitrogen, concentrations ranged from less than 0.002 to 0.19 mg/L (milligrams per liter). Ammonia, as nitrogen, concentrations ranged from less than 0.01 to 0.16 mg/L. Orthophosphate, as phosphorus, concentrations ranged from less than 0.002 to 0.14 mg/L. Calcium, magnesium, potassium, sulfate, and chloride concentrations in surface water were elevated due to the marine influence on the composition of surface water in the Barataria Preserve during the sampling period. Sulfate and chloride concentrations reached 379 and 2

  19. Reconstructing Holocene bottom water oxygenation and fluvial discharge in the marine environment near Eureka, California using a portable XRF method

    Science.gov (United States)

    Burtt, D. G.; Addison, J. A.; Foster, A. L.

    2013-12-01

    X-ray fluorescence (XRF) spectrometry is a method of performing chemical composition analysis of bulk samples. Traditionally, samples are processed gradually over days or weeks to create topographically flat, dry, and homogenous compositions. The current experiment applies this technique for rapid measurement of chemical composition in intact marine sediment cores. We used a handheld Thermo Scientific NitonXL3t-950 XRF to measure the core TN062-O550 (40.867 N, 124.572 W, 550 m water depth), which was collected from 13 km off the coast of Eureka, California. Custom calibrations were developed to accommodate marine sediments, and measurements collected by hand were compared to those taken using a custom-built sediment core stand. Following the initial calibration tests, the portable XRF was used to assess water column oxygen levels within TN062-O550 over the last 4000 years. This assessment was based upon the relatively well-known correspondence between iron and titanium, which can be used to infer the relative abundance of ferric and ferrous minerals, and therefore serve as a proxy for ambient oxygen levels. In addition to testing the oxygenation, these analyses were used to investigate the potential correlation between iron levels and deposition by fluvial discharge and/or surface run-off (rainfall). We found a strongly positive correlation between iron and titanium throughout the length of the core. This correlation suggests that more oxidized iron has accumulated than reduced iron, thus implying oxygenation in the water column and/or upper sediment profile. This is further supported by pervasive bioturbation in the sediment core. These results also have implications for applying these geochemical data as a proxy for regional precipitation and/or fluvial deposition in the marine environment. Based on a preliminary age-depth model developed for TN062-O550, and application of the iron and titanium concentrations as a precipitation proxy, there is a relative maximum

  20. BOTTOM DEPOSITS OF STRATIFIED, SEEPAGE, URBAN LAKE (ON EXAMPLE OF TYRSKO LAKE, POLAND AS A FACTOR POTENTIALLY SHAPING LAKE WATER QUALITY

    Directory of Open Access Journals (Sweden)

    Renata Augustyniak

    2017-09-01

    The obtained results revealed, that bottom sediment of Tyrsko Lake can be classified as mixed, silica-organic type, with quite high content of iron (over 4% Fe in d.w.. The total phosphorus content was ca. 3.5 mg P g-1 d.w. on average. Phosphorus in bottom sediment was bound mainly with organic matter (NaOH-nrP fraction, which had over 50% share in TP. Easy mobile fractions (NH4-Cl-P and BD-P together included ca 5% to 7 % TP only. The obtained results show, that bottom sediment of Tyrsko Lake can bind phosphorus quite effectively. Calculated internal mineral phosphorus loading during summer stagnation period was 10.9 kg P and it was lower that the assessed annual external phosphorus load (22.6 kg P y-1. The assessed annual phosphorus loading from both sources still was lower than critical load according to Vollenweider criteria. But due to the fact that internal loading phenomenon is occurring in the lake it should be taken into consideration that the lake water quality can deteriorate gradually during the longer time perspective. These findings should be taken into consideration in the future if the potential protection and restoration procedures will be developed.

  1. Ocean bottom pressure modeling for detection of seafloor vertical deformation

    Science.gov (United States)

    Inazu, D.; Hino, R.; Fujimoto, H.

    2009-12-01

    Detection of seafloor crustal deformation is a difficult problem in marine geodesy. Horizontal displacement of the ocean bottom has been detected with accuracy of several centimeters per year by the GPS/Acoustic positioning of seafloor reference points (Spiess et al. 1998). Meanwhile, bottom pressure observations can record the vertical deformation of seafloor and there have been many challenges to detect vertical seafloor displacement. However, ocean bottom pressure variations are highly dominated by oceanic signals such as tidal and subinertial motions. The tidal and other oceanic variations in bottom pressure records are mostly equivalent to several tens and several centimeters water height anomalies, respectively. Generally, the ocean tide is efficiently corrected. Non-tidal components are required to be accurately removed from the bottom pressure records so that the vertical displacement of less than ten centimeters, the expected amount of displacement caused by slow slip events often observed in several subduction zones, is detected by continuous bottom pressure monitoring. We examine the bottom pressure estimations derived from the Kalman filter and smoother runs of the ECCO (Estimating the Circulation & Climate of the Ocean) product to compare in-situ bottom pressure records. The assimilated bottom pressure moderately represents the seasonal variation, and hardly represents the variation with periods less than a few months. This high frequency variation is mainly explained by the barotropic phenomena induced by meteorological disturbances. Hirose et al. (2001) and Carrère and Lyard (2003) modeled the barotropic ocean motion with the forcing of atmospheric pressure loading and wind over global oceans for the sake of the correction of satellite observations. This study addresses the accurate bottom pressure modeling, which enables us to detect vertical displacement of several centimeters from the in-situ bottom pressure observations. We develop accurate

  2. Rapid bottom-water circulation changes during the last glacial cycle in the coastal low-latitude NE Atlantic

    NARCIS (Netherlands)

    Gallego-Torres, D.; Romero, O.E.; Martínez-Ruiz, F.; Kim, J.-H.; Donner, B.; Ortega-Huertas, M.

    2014-01-01

    Previous paleoceanographic studies along the NW African margin focused on the dynamics of surface and intermediate waters, whereas little attention has been devoted to deep-water masses. Currently, these deep waters consist mainly of North Atlantic Deep Waters as part of the Atlantic Meridional

  3. Bactericidal Effect of Strong Acid Electrolyzed Water against Flow Enterococcus faecalis Biofilms.

    Science.gov (United States)

    Cheng, Xiaogang; Tian, Yu; Zhao, Chunmiao; Qu, Tiejun; Ma, Chi; Liu, Xiaohua; Yu, Qing

    2016-07-01

    This study evaluated the bactericidal effect of strong acid electrolyzed water (SAEW) against flow Enterococcus faecalis biofilm and its potential application as a root canal irrigant. Flow E. faecalis biofilms were generated under a constant shear flow in a microfluidic system. For comparison, static E. faecalis biofilms were generated under a static condition on coverslip surfaces. Both the flow and static E. faecalis biofilms were treated with SAEW. Sodium hypochlorite (NaOCl, 5.25%) and normal saline (0.9%) were included as the controls. Bacterial reductions were evaluated using confocal laser scanning microscopy and the cell count method. Morphological changes of bacterial cells were observed using scanning electron microscopy. The confocal laser scanning microscopic and cell count results showed that SAEW had a bactericidal effect similar to that of 5.25% NaOCl against both the flow and static E. faecalis biofilms. The scanning electron microscopic results showed that smooth, consecutive, and bright bacteria surfaces became rough, shrunken, and even lysed after treated with SAEW, similar to those in the NaOCl group. SAEW had an effective bactericidal effect against both the flow and static E. faecalis biofilms, and it might be qualified as a root canal irrigant for effective root canal disinfection. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  4. Clastic Pipes: Proxies of High Water Tables and Strong Ground Motion, Jurassic Carmel Formation, Southern Utah

    Science.gov (United States)

    Wheatley, David; Chan, Marjorie

    2015-04-01

    Multiple soft sediment deformation features from bed-scale to basin-scale are well preserved within the Jurassic Carmel Formation of Southern Utah. Field mapping reveals thousands of small-scale clastic injectite pipes (10 cm to 10 m diameter, up to 20 m tall) in extremely high densities (up to 500+ pipes per 0.075 square kilometers). The pipes weather out in positive relief from the surrounding host strata of massive sandstone (sabkha) and crossbedded sands with minor conglomerate and shale (fluvial) deposits. The host rock shows both brittle and ductile deformation. Reverse, normal, and antithetical faulting is common with increased frequency, including ring faults, surrounding the pipes. The pipes formed from liquefaction and subsequent fluidization induced by strong ground motion. Down-dropped, graben blocks and ring faults surrounding pipes indicate initial sediment volume increase during pipe emplacement followed by sediment volume decrease during dewatering. Complex crosscutting relationships indicate several injection events where some pipe events reached the surface as sand blows. Multiple ash layers provide excellent stratigraphic and temporal constraints for the pipe system with the host strata deposited between 166 and 164 Ma. Common volcanic fragments and rounded volcanic cobbles occur within sandstone and conglomerate beds, and pipes. Isolated volcanic clasts in massive sandstone indicate explosive volcanic events that could have been the exogenic trigger for earthquakes. The distribution of pipes are roughly parallel to the Middle Jurassic paleoshoreline located in marginal environments between the shallow epicontinental Sundance Sea and continental dryland. At the vertical stratigraphic facies change from dominantly fluvial sediments to dominantly massive sabkha sediments, there is a 1-2 m-thick floodplain mudstone that was a likely seal for underlying, overpressurized sediments. The combination of loose porous sediment at a critical depth of water

  5. Effect of Strongly Alkaline Electrolyzed Water on Silk Degumming and the Physical Properties of the Fibroin Fiber

    OpenAIRE

    Cao, Ting-Ting; Wang, Yuan-Jing; Zhang, Yu-Qing

    2013-01-01

    Strongly alkaline electrolyzed water (SAEW) was prepared by electrolysis of tap water in a laboratory-made water electrolyzer. The pH of stored SAEW was stable for more than one month. The hardness of the electrolyzed water was 30% lower and the Na(+) concentration was 18% higher than those of the tap water. Silkworm cocoon shells were boiled in pH 11.50 SAEW at a ratio of 1∶40∼80 (W/V) for 20 min and the sericin layers around the silk fibroin fibers were removed completely. The tensile prope...

  6. Chemicals of emerging concern in water and bottom sediment in Great Lakes areas of concern, 2010 to 2011-Collection methods, analyses methods, quality assurance, and data

    Science.gov (United States)

    Lee, Kathy E.; Langer, Susan K.; Menheer, Michael A.; Foreman, William T.; Furlong, Edward T.; Smith, Steven G.

    2012-01-01

    The U.S. Geological Survey (USGS) cooperated with the U.S. Environmental Protection Agency and the U.S. Fish and Wildlife Service on a study to identify the occurrence of chemicals of emerging concern (CECs) in water and bottom-sediment samples collected during 2010–11 at sites in seven areas of concern (AOCs) throughout the Great Lakes. Study sites include tributaries to the Great Lakes in AOCs located near Duluth, Minn.; Green Bay, Wis.; Roches­ter, N.Y.; Detroit, Mich.; Toledo, Ohio; Milwaukee, Wis.; and Ashtabula, Ohio. This report documents the collection meth­ods, analyses methods, quality-assurance data and analyses, and provides the data for this study. Water and bottom-sediment samples were analyzed at the USGS National Water Quality Laboratory in Denver, Colo., for a broad suite of CECs. During this study, 135 environmental and 23 field dupli­cate samples of surface water and wastewater effluent, 10 field blank water samples, and 11 field spike water samples were collected and analyzed. Sixty-one of the 69 wastewater indicator chemicals (laboratory method 4433) analyzed were detected at concentrations ranging from 0.002 to 11.2 micrograms per liter. Twenty-eight of the 48 pharmaceuticals (research method 8244) analyzed were detected at concentrations ranging from 0.0029 to 22.0 micro­grams per liter. Ten of the 20 steroid hormones and sterols analyzed (research method 4434) were detected at concentrations ranging from 0.16 to 10,000 nanograms per liter. During this study, 75 environmental, 13 field duplicate samples, and 9 field spike samples of bottom sediment were collected and analyzed for a wide variety of CECs. Forty-seven of the 57 wastewater indicator chemicals (laboratory method 5433) analyzed were detected at concentrations ranging from 0.921 to 25,800 nanograms per gram. Seventeen of the 20 steroid hormones and sterols (research method 6434) analyzed were detected at concentrations ranging from 0.006 to 8,921 nanograms per gram. Twelve of

  7. THE INFLUENCE OF SEA-LEVEL CHANGES ON SEA-BOTTOM MORPHOLOGY OF SINGKAWANG WATERS WEST KALIMANTAN BASED ON ANALYSES OF BATHYMETRIC AND SEISMIC DATA

    Directory of Open Access Journals (Sweden)

    Hananto Kurnio

    2017-07-01

    Full Text Available In the history of Quaternary geology, global climate changes influenced worldwide sea-level variations. On this study, these phenomena are tried to be assessed through sea-bottom morphology changes using bathymetric and seismic strata box data obtained during field survey in Singkawang Waters, West Kalimantan. Sea-level changes in this area are referred to global variations that had been studied by many researchers. Maximal depth attained during bathymetry mapping was -52 meters which take place as a depression between Lemukutan and Penata Besar Islands. General depths are - 30 m; thus, morphology reconstruction was done for sea-level positions - 10 m, - 20 m, and - 30 m from mean sea level. At the study area, sea-level dropped more than -30 m was only occurred in sea bottom morphology of isolated depressions. These isolated depressions are assumed as paleo-lakes which occurred throughout Sunda Land by some authors. The study also shows that sea-level history in Singkawang’s area span from approximately 10,000 years ago or Holocene time to Recent. During low sea-levels, the sea-bottom morphology was characterized by more extension of Singkawang land, formations of narrow straits between islands and developments of paleo-lakes assumed as fresh water lakes in the past. These events, based on Voris’s Diagram, occurred about 10,200 up to 8,300 years ago. On the other hand, marine clays appeared on coastal area of Singkawang. These might be evidence of sea-level rise in this area. About + 5m sea-level rise flooded this area approximately 4,200 years ago. Influences of sea-level changes to subbottom geological conditions were also assessed. The assessment was carried out by analyzing shallow seismic reflection records by using strata box. The records demonstrated that subsurface geology were characterized by truncation reflector configurations interpreted as fluvial environments.

  8. Bottom friction optimization for a better barotropic tide modelling

    Science.gov (United States)

    Boutet, Martial; Lathuilière, Cyril; Son Hoang, Hong; Baraille, Rémy

    2015-04-01

    At a regional scale, barotropic tides are the dominant source of variability of currents and water heights. A precise representation of these processes is essential because of their great impacts on human activities (submersion risks, marine renewable energies, ...). Identified sources of error for tide modelling at a regional scale are the followings: bathymetry, boundary forcing and dissipation due to bottom friction. Nevertheless, bathymetric databases are nowadays known with a good accuracy, especially over shelves, and global tide models performances are better than ever. The most promising improvement is thus the bottom friction representation. The method used to estimate bottom friction is the simultaneous perturbation stochastic approximation (SPSA) which consists in the approximation of the gradient based on a fixed number of cost function measurements, regardless of the dimension of the vector to be estimated. Indeed, each cost function measurement is obtained by randomly perturbing every component of the parameter vector. An important feature of SPSA is its relative ease of implementation. In particular, the method does not require the development of tangent linear and adjoint version of the circulation model. Experiments are carried out to estimate bottom friction with the HYbrid Coordinate Ocean Model (HYCOM) in barotropic mode (one isopycnal layer). The study area is the Northeastern Atlantic margin which is characterized by strong currents and an intense dissipation. Bottom friction is parameterized with a quadratic term and friction coefficient is computed with the water height and the bottom roughness. The latter parameter is the one to be estimated. Assimilated data are the available tide gauge observations. First, the bottom roughness is estimated taking into account bottom sediment natures and bathymetric ranges. Then, it is estimated with geographical degrees of freedom. Finally, the impact of the estimation of a mixed quadratic/linear friction

  9. Temporal structure of an electric signal produced upon interaction of radiation from a HF laser with the bottom surface of a water column

    International Nuclear Information System (INIS)

    Andreev, Sergei N; Kazantsev, S Yu; Kononov, I G; Pashinin, Pavel P; Firsov, K N

    2009-01-01

    Generation of an electric signal is investigated when a HF-laser pulse interacts with the lower surface of a water column in a cell with a bottom transparent to laser radiation, while the upper surface of the water column remains open. The electric signal exhibits a temporal structure of two spikes spaced by time τ which is linearly dependent on the laser output energy. It is found that the value of τ (up to 1.3 ms) is an order of magnitude greater than the time during which the vapour pressure in a cavity produced due to the volume explosive boiling of water in the exposed area is greater than the atmospheric pressure. The second spike was determined to appear upon the collapse of the vapour cavity. A mathematical model is constructed that explains the motion of the water column above the vapour cavity taking into account the temporal evolution of the vapour pressure above it. It is shown that the prolonged lifetime of the vapour cavity after the decrease in the vapour pressure down to the atmospheric value is caused by the inertial motion of the water column acquiring the velocity at the initial stage of the cavity expansion. The calculated time of the water column motion agrees well with the experimental time interval between the spikes of an electric signal. (interaction of laser radiation with matter)

  10. WAVECALC: an Excel-VBA spreadsheet to model the characteristics of fully developed waves and their influence on bottom sediments in different water depths

    Science.gov (United States)

    Le Roux, Jacobus P.; Demirbilek, Zeki; Brodalka, Marysia; Flemming, Burghard W.

    2010-10-01

    The generation and growth of waves in deep water is controlled by winds blowing over the sea surface. In fully developed sea states, where winds and waves are in equilibrium, wave parameters may be calculated directly from the wind velocity. We provide an Excel spreadsheet to compute the wave period, length, height and celerity, as well as horizontal and vertical particle velocities for any water depth, bottom slope, and distance below the reference water level. The wave profile and propagation can also be visualized for any water depth, modeling the sea surface change from sinusoidal to trochoidal and finally cnoidal profiles into shallow water. Bedload entrainment is estimated under both the wave crest and the trough, using the horizontal water particle velocity at the top of the boundary layer. The calculations are programmed in an Excel file called WAVECALC, which is available online to authorized users. Although many of the recently published formulas are based on theoretical arguments, the values agree well with several existing theories and limited field and laboratory observations. WAVECALC is a user-friendly program intended for sedimentologists, coastal engineers and oceanographers, as well as marine ecologists and biologists. It provides a rapid means to calculate many wave characteristics required in coastal and shallow marine studies, and can also serve as an educational tool.

  11. Bottom lines

    International Nuclear Information System (INIS)

    Dabbs, F.

    1998-01-01

    The technological challenges facing the Alberta oilpatch in 1998 were reviewed. Attention was drawn to the fallacy of certain neo-conservative views, held by some members of the provincial government. This view holds that technology development is not a public concern and should be left entirely to the private sector. It is argued that rather than leaving it to the private sector, the government should play a strong leadership role. The government should do this by setting the agenda, by providing substantial and patient funding, by initiating partnerships with the private sector and by being a committed partner and catalyst in technology transfer. In support of this contention, the achievements of the Alberta Oil Sands Technology and Research Authority (AOSTRA) and of the Alberta Research Council were cite., These include the work on horizontal drilling, top-drive rigs, advanced exploration software, oilsands mining innovations, the steam-assisted gravity drainage (SAGD) technology, and the Taciuk process for bitumen recovery. All of these technologies, developed by government-industry funding, have contributed immeasurably to the Alberta economic miracle. Public expenditures on funding these research projects were but a fraction of the billions of dollars that have been, and will continue to be, returned to the people of Alberta in licence fees and royalties. In 1998, in the wake of the Kyoto Conference, the need for government leadership in energy research is even greater than it has been in the past. Nothing less than the viability of the fossil fuel industry and the Alberta economy depend upon finding solutions to the production and processing of greenhouse gas emissions

  12. Restrictions in Mg/Ca-Paleotemperature Estimations in High-Latitude Bottom Waters: Evidence from the Fram Strait and the Nordic Seas

    Science.gov (United States)

    Werner, K.; Marchitto, T. M., Jr.; Not, C.; Spielhagen, R. F.; Husum, K.

    2014-12-01

    Mg to Ca ratios of the benthic foraminifer species Cibicidoides wuellerstorfi provide a great potential for reconstructing bottom water temperatures, especially from the lower end of the temperature range between 0 and 6°C (Tisserand et al., 2013). A set of core top samples from the Fram Strait and the Norwegian margin have been studied for Mg/Ca ratios in C. wuellerstorfi in order to establish a calibration relationship to the environmental conditions. In this part of the northern North Atlantic the bottom water temperature range between -0.5 and -1°C. For the calibration to modern water mass conditions, modern oceanographic data from both existing conductivity-temperature-depth (CTD) casts and the World Ocean Data Base 2013 (Boyer et al., 2013) have been used. Benthic Mg/Ca ratios are relatively high suggesting a preference of C. wuellerstorfi to incorporate Mg below 0°C. Although no correlation has been found to existing temperature calibrations, the data are in line with earlier Mg/Ca data from C. wuellerstorfi in the area (Martin et al., 2002; Elderfield et al., 2006). The carbonate ion effect is most likely a main cause for the relatively high Mg/Ca ratios found in core top samples from the Fram Strait and the Nordic Seas, however, other factors may influence the values as well. Holocene records of benthic trace metal/Ca ratios from the eastern Fram Strait display trends similar to those found in other proxy indicators, despite the difficulties to constrain a temperature calibration for this low temperature range. In particular, the benthic B/Ca and Li/Ca records resemble trends in Holocene planktic foraminifer assemblages, suggesting to be influenced by environmental factors such as the carbonate ion effect consistent for the entire water column.

  13. Expanded U.S. mid-Atlantic Margin Deep-Water Allostratigraphy; Bottom-Current Controls on Margin Evolution

    Science.gov (United States)

    Gibson, J. C.; Miller, N. C.; Hutchinson, D. R.; Ten Brink, U. S.; Mountain, G. S.; Chaytor, J. D.; Shillington, D. J.

    2017-12-01

    redistributed is unknown, but the magnitude and spatial extent of the bottom-current erosion are well constrained by our study. The southern MAM has experienced a number of significant mass wasting events spanning the Miocene-Pleistocene, suggesting that bottom-current erosion may have played a role in undercutting, and therefore over-steepening the slope.

  14. Reconnaissance investigation of water quality, bottom sediment, and biota associated with irrigation drainage in the middle Green River basin, Utah, 1986-87

    Science.gov (United States)

    Stephens, D.W.; Waddell, Bruce; Miller, J.B.

    1988-01-01

    Reconnaissance of wildlife areas in the middle Green River basin of Utah was conducted during 1986 and 1987 to determine whether irrigation drainage has caused, or has the potential to cause significant harmful effects on human health, fish, and wildlife, or may adversely affect the suitability of water for beneficial uses. Studies at Stewart Lake Waterfowl Management Area and Ouray National Wildlife Refuge indicated that concentrations of boron, selenium, and zinc in water, bottom sediment, and biological tissue were sufficiently large to be harmful to fish and wildlife, and to adversely affect beneficial uses of water. Selenium is the principal element of concern in both areas. Concentrations of dissolved selenium in irrigation drain water entering Stewart Lake Waterfowl Management Area ranged from 14-140 micrograms/L (ug/L) and consistently exceeded Utah standards for wildlife protection in water in two of the four drains. Concentrations of boron and zinc exceeded Utah standards only occasionally in the drain waters. Concentrations of total selenium in sediments collected where the drains discharge into the lake were 10-85 ug/gm. Liver tissue collected from American coots at Stewart Lake Waterfowl Management Area contained concentrations of selenium from 4.9-26 ug/gm (dry weight), and whole body samples of carp contained as much as 31 ug/gm (dry weight). Concentrations of selenium in Potamogeton and blue-green algae ranged from 2.1-27 ug/gm. Concentrations of boron, selenium, and zinc were also measured in water from Ouray National Wildlife Refuge. Liver tissue of American coots from the North Roadside Pond, which receives irrigation tailwater, contained a geometric-mean concentration of selenium of 32 ug/gm (dry weight). Five water-bird eggs collected from the North and South Roadside Ponds contained selenium concentrations of 63-120 ug/gm (dry weight). (Lantz-PTT)

  15. Chlor-alkali industrial contamination and riverine transport of mercury: Distribution and partitioning of mercury between water, suspended matter, and bottom sediment of the Thur River, France

    International Nuclear Information System (INIS)

    Hissler, Christophe; Probst, Jean-Luc

    2006-01-01

    Total dissolved and total particulate Hg mass balances were estimated during one hydrological period (July 2001-June 2002) in the Thur River basin, which is heavily polluted by chlor-alkali industrial activity. The seasonal variations of the Hg dynamics in the aquatic environment were assessed using total Hg concentrations in bottom sediment and suspended matter, and total and reactive dissolved Hg concentrations in the water. The impact of the chlor-alkali plant (CAP) remains the largest concern for Hg contamination of this river system. Upstream from the CAP, the Hg partitioning between dissolved and particulate phases was principally controlled by the dissolved fraction due to snow melting during spring high flow, while during low flow, Hg was primarily adsorbed onto particulates. Downstream from the CAP, the Hg partitioning is controlled by the concentration of dissolved organic and inorganic ligands and by the total suspended sediment (TSS) concentrations. Nevertheless, the particulate fluxes were five times higher than the dissolved ones. Most of the total annual flux of Hg supplied by the CAP to the river is transported to the outlet of the catchment (total Hg flux: 70 μg m -2 a -1 ). Downstream from the CAP, the bottom sediment, mainly composed of coarse sediment (>63 μm) and depleted in organic matter, has a weak capacity to trap Hg in the river channel and the stock of Hg is low (4 mg m -2 ) showing that the residence time of Hg in this river is short

  16. Assessment of Near-Bottom Water Quality of Southwestern Coast of Sarawak, Borneo, Malaysia: A Multivariate Statistical Approach

    Directory of Open Access Journals (Sweden)

    Chen-Lin Soo

    2017-01-01

    Full Text Available The study on Sarawak coastal water quality is scarce, not to mention the application of the multivariate statistical approach to investigate the spatial variation of water quality and to identify the pollution source in Sarawak coastal water. Hence, the present study aimed to evaluate the spatial variation of water quality along the coastline of the southwestern region of Sarawak using multivariate statistical techniques. Seventeen physicochemical parameters were measured at 11 stations along the coastline with approximately 225 km length. The coastal water quality showed spatial heterogeneity where the cluster analysis grouped the 11 stations into four different clusters. Deterioration in coastal water quality has been observed in different regions of Sarawak corresponding to land use patterns in the region. Nevertheless, nitrate-nitrogen exceeded the guideline value at all sampling stations along the coastline. The principal component analysis (PCA has determined a reduced number of five principal components that explained 89.0% of the data set variance. The first PC indicated that the nutrients were the dominant polluting factors, which is attributed to the domestic, agricultural, and aquaculture activities, followed by the suspended solids in the second PC which are related to the logging activities.

  17. Hydrogen gas generation from metal aluminum-water interaction in municipal solid waste incineration (MSWI) bottom ash.

    Science.gov (United States)

    Nithiya, Arumugam; Saffarzadeh, Amirhomayoun; Shimaoka, Takayuki

    2018-03-01

    In the present research, municipal solid waste incineration (MSWI) bottom ash (BA) residues from three incinerators (N, K, and R) in Japan were collected for hydrogen gas generation purpose. The samples were split into four particle size fractions: (1) d≤0.6, (2) 0.6≤d≤1.0, (3) 1.0≤d≤2.0, and (4) 2.0≤d≤4.75mm for the characterization of metal aluminum, the relationship between the present metal aluminum and hydrogen gas production, and the influence of external metal aluminum on the enhancement of hydrogen gas. The batch experiments were performed for each BA fraction under agitated (200rpm) and non-agitated conditions at 40°C for 20days. The highest amount of hydrogen gas (cumulative) was collected under agitation condition that was 39.4, 10.0, and 8.4 L/kg of dry ash for N2, R2, and K2 (all fraction 2), respectively. To take the benefit of the BA high alkalinity (with initial pH over 12), 0.1 and 1g of household aluminum foil were added to the fractions 2 and 3. A Significantly larger amount of hydrogen gas was collected from each test. For 0.1g of aluminum foil, the cumulative amount of gas was in the range of 62 to 78 L/kg of dry ash and for 1g of aluminum foil the cumulative amount of hydrogen was in the range of 119-126 L/kg of dry ash. This indicated that the hydrogen gas yield was significantly a function of supplementary aluminum and the intrinsic alkaline environment of the BA residues rather than ash source or particle size. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Occurrence and partitioning of antibiotic compounds found in the water column and bottom sediments from a stream receiving two wastewater treatment plant effluents in Northern New Jersey, 2008

    International Nuclear Information System (INIS)

    Gibs, Jacob; Heckathorn, Heather A.; Meyer, Michael T.; Klapinski, Frank R.; Alebus, Marzooq; Lippincott, Robert L.

    2013-01-01

    An urban watershed in northern New Jersey was studied to determine the presence of four classes of antibiotic compounds (macrolides, fluoroquinolones, sulfonamides, and tetracyclines) and six degradates in the water column and bottom sediments upstream and downstream from the discharges of two wastewater treatment plants (WWTPs) and a drinking-water intake (DWI). Many antibiotic compounds in the four classes not removed by conventional WWTPs enter receiving waters and partition to stream sediments. Samples were collected at nine sampling locations on 2 days in September 2008. Two of the nine sampling locations were background sites upstream from two WWTP discharges on Hohokus Brook. Another background site was located upstream from a DWI on the Saddle River above the confluence with Hohokus Brook. Because there is a weir downstream of the confluence of Hohokus Brook and Saddle River, the DWI receives water from Hohokus Brook at low stream flows. Eight antibiotic compounds (azithromycin (maximum concentration 0.24 μg/L), ciprofloxacin (0.08 μg/L), enrofloxacin (0.015 μg/L), erythromycin (0.024 μg/L), ofloxacin (0.92 μg/L), sulfamethazine (0.018 μg/L), sulfamethoxazole (0.25 μg/L), and trimethoprim (0.14 μg/L)) and a degradate (erythromycin–H 2 O (0.84 μg/L)) were detected in the water samples from the sites downstream from the WWTP discharges. The concentrations of six of the eight detected compounds and the detected degradate compound decreased with increasing distance downstream from the WWTP discharges. Azithromycin, ciprofloxacin, ofloxacin, and trimethoprim were detected in stream-bottom sediments. The concentrations of three of the four compounds detected in sediments were highest at a sampling site located downstream from the WWTP discharges. Trimethoprim was detected in the sediments from a background site. Pseudo-partition coefficients normalized for streambed sediment organic carbon concentration were calculated for azithromycin, ciprofloxacin

  19. Occurrence and partitioning of antibiotic compounds found in the water column and bottom sediments from a stream receiving two wastewater treatment plant effluents in Northern New Jersey, 2008

    Energy Technology Data Exchange (ETDEWEB)

    Gibs, Jacob, E-mail: jgibs@usgs.gov [U.S. Geological Survey, 810 Bear Tavern Road, West Trenton, NJ 08628 (United States); Heckathorn, Heather A. [U.S. Geological Survey, 810 Bear Tavern Road, West Trenton, NJ 08628 (United States); Meyer, Michael T. [U.S. Geological Survey, 4821 Quail Crest Place, Lawrence, KS 66049 (United States); Klapinski, Frank R.; Alebus, Marzooq; Lippincott, Robert L. [New Jersey Department of Environmental Protection, PO Box 413, Trenton, NJ 08625 (United States)

    2013-08-01

    An urban watershed in northern New Jersey was studied to determine the presence of four classes of antibiotic compounds (macrolides, fluoroquinolones, sulfonamides, and tetracyclines) and six degradates in the water column and bottom sediments upstream and downstream from the discharges of two wastewater treatment plants (WWTPs) and a drinking-water intake (DWI). Many antibiotic compounds in the four classes not removed by conventional WWTPs enter receiving waters and partition to stream sediments. Samples were collected at nine sampling locations on 2 days in September 2008. Two of the nine sampling locations were background sites upstream from two WWTP discharges on Hohokus Brook. Another background site was located upstream from a DWI on the Saddle River above the confluence with Hohokus Brook. Because there is a weir downstream of the confluence of Hohokus Brook and Saddle River, the DWI receives water from Hohokus Brook at low stream flows. Eight antibiotic compounds (azithromycin (maximum concentration 0.24 μg/L), ciprofloxacin (0.08 μg/L), enrofloxacin (0.015 μg/L), erythromycin (0.024 μg/L), ofloxacin (0.92 μg/L), sulfamethazine (0.018 μg/L), sulfamethoxazole (0.25 μg/L), and trimethoprim (0.14 μg/L)) and a degradate (erythromycin–H{sub 2}O (0.84 μg/L)) were detected in the water samples from the sites downstream from the WWTP discharges. The concentrations of six of the eight detected compounds and the detected degradate compound decreased with increasing distance downstream from the WWTP discharges. Azithromycin, ciprofloxacin, ofloxacin, and trimethoprim were detected in stream-bottom sediments. The concentrations of three of the four compounds detected in sediments were highest at a sampling site located downstream from the WWTP discharges. Trimethoprim was detected in the sediments from a background site. Pseudo-partition coefficients normalized for streambed sediment organic carbon concentration were calculated for azithromycin

  20. Discharge and water-quality data for selected streams at low flow including some bottom-material analyses, and limnological study of six lakes, Westchester County, New York

    Science.gov (United States)

    Archer, Roger J.; Turk, John T.

    1977-01-01

    Water-quality data collected at sites on 33 Westchester County, N.Y., streams August 4 to 6, 1976 during low flow (80-percent or more duration) indicate that although the chemical characteristics of most streams met State standards for water-supply source waters, none met the coliform standard, and several failed to meet standards for organic nitrogen, pH, and dissolved oxygen. Chemical analyses of bottom materials indicated detectable concentrations of the insecticides chlordane, dieldrin, and DDT at most of the 17 stream sites sampled. Polychlorinated biphenyls(PCB's) were found in more than half the samples, and the lead concentration on one stream was significantly higher than at the other sites. The six lakes studied are similar in bedrock geology, climate, and algal types and numbers. Minor differences in the chemistry of the lakes is attributable to the presence or absence of marble (calcium carbonate) in the gneissic basins, septic loadings of soluble constituents, or runoff containing salt from winter road deicing. The lakes probably receive most of their water by direct runoff and groundwater seepage rather than from major streams. All six lakes can be classed as eutrophic on the basis of algal type and density, dissolved-oxygen distribution, and nitrogen and phosphorus concentrations. (Woodard-USGS)

  1. Bottom-Water Conditions in a Marine Basin after the Cretaceous–Paleogene Impact Event: Timing the Recovery of Oxygen Levels and Productivity

    Science.gov (United States)

    Sosa-Montes De Oca, Claudia; Martínez-Ruiz, Francisca; Rodríguez-Tovar, Francisco Javier

    2013-01-01

    An ultra-high-resolution analysis of major and trace element contents from the Cretaceous–Paleogene boundary interval in the Caravaca section, southeast Spain, reveals a quick recovery of depositional conditions after the impact event. Enrichment/depletion profiles of redox sensitive elements indicate significant geochemical anomalies just within the boundary ejecta layer, supporting an instantaneous recovery –some 102 years– of pre-impact conditions in terms of oxygenation. Geochemical redox proxies point to oxygen levels comparable to those at the end of the Cretaceous shortly after impact, which is further evidenced by the contemporary macrobenthic colonization of opportunistic tracemakers. Recovery of the oxygen conditions was therefore several orders shorter than traditional proposals (104–105 years), suggesting a probable rapid recovery of deep-sea ecosystems at bottom and in intermediate waters. PMID:24349232

  2. Bottom-water conditions in a marine basin after the Cretaceous-Paleogene impact event: timing the recovery of oxygen levels and productivity.

    Directory of Open Access Journals (Sweden)

    Claudia Sosa-Montes De Oca

    Full Text Available An ultra-high-resolution analysis of major and trace element contents from the Cretaceous-Paleogene boundary interval in the Caravaca section, southeast Spain, reveals a quick recovery of depositional conditions after the impact event. Enrichment/depletion profiles of redox sensitive elements indicate significant geochemical anomalies just within the boundary ejecta layer, supporting an instantaneous recovery--some 10(2 years--of pre-impact conditions in terms of oxygenation. Geochemical redox proxies point to oxygen levels comparable to those at the end of the Cretaceous shortly after impact, which is further evidenced by the contemporary macrobenthic colonization of opportunistic tracemakers. Recovery of the oxygen conditions was therefore several orders shorter than traditional proposals (10(4-10(5 years, suggesting a probable rapid recovery of deep-sea ecosystems at bottom and in intermediate waters.

  3. Bottom-water conditions in a marine basin after the Cretaceous-Paleogene impact event: timing the recovery of oxygen levels and productivity.

    Science.gov (United States)

    Sosa-Montes De Oca, Claudia; Martínez-Ruiz, Francisca; Rodríguez-Tovar, Francisco Javier

    2013-01-01

    An ultra-high-resolution analysis of major and trace element contents from the Cretaceous-Paleogene boundary interval in the Caravaca section, southeast Spain, reveals a quick recovery of depositional conditions after the impact event. Enrichment/depletion profiles of redox sensitive elements indicate significant geochemical anomalies just within the boundary ejecta layer, supporting an instantaneous recovery--some 10(2) years--of pre-impact conditions in terms of oxygenation. Geochemical redox proxies point to oxygen levels comparable to those at the end of the Cretaceous shortly after impact, which is further evidenced by the contemporary macrobenthic colonization of opportunistic tracemakers. Recovery of the oxygen conditions was therefore several orders shorter than traditional proposals (10(4)-10(5) years), suggesting a probable rapid recovery of deep-sea ecosystems at bottom and in intermediate waters.

  4. Prevention of strong stench for stocked radioisotope sewerage using total water treatment agent for small-sized cooling towers

    International Nuclear Information System (INIS)

    Aoki, Katsumi; Nishimaki, Toshiyuki; Furuse, Yuko; Shinozuka, Akiko

    1996-01-01

    In general, the sewerage at radioisotope laboratories has very strong stench. We treated the sewerage with a total water treatment agent (Tachileslegi, Nippon Nouyaku Co., Ltd. ) that is widely used for prevention of slime, scale, corrosion in cooling towers. As the result, the stench was decreased to about two thirds to that of control estimated by odor-test. (author)

  5. Strong CH/O interactions between polycyclic aromatic hydrocarbons and water: Influence of aromatic system size.

    Science.gov (United States)

    Veljković, Dušan Ž

    2018-03-01

    Energies of CH/O interactions between water molecule and polycyclic aromatic hydrocarbons with a different number of aromatic rings were calculated using ab initio calculations at MP2/cc-PVTZ level. Results show that an additional aromatic ring in structure of polycyclic aromatic hydrocarbons significantly strengthens CH/O interactions. Calculated interaction energies in optimized structures of the most stable tetracene/water complex is -2.27 kcal/mol, anthracene/water is -2.13 kcal/mol and naphthalene/water is -1.97 kcal/mol. These interactions are stronger than CH/O contacts in benzene/water complex (-1.44 kcal/mol) while CH/O contacts in tetracene/water complex are even stronger than CH/O contacts in pyridine/water complexes (-2.21 kcal/mol). Electrostatic potential maps for different polycyclic aromatic hydrocarbons were calculated and used to explain trends in the energies of interactions. Copyright © 2017 Elsevier Inc. All rights reserved.

  6. Food Waste to Energy: How Six Water Resource Recovery Facilities are Boosting Biogas Production and the Bottom Line

    Science.gov (United States)

    Water Resource Recovery Facilities (WRRFs) with anaerobic digestion have been harnessing biogas for heat and power since at least the 1920’s. A few are approaching “energy neutrality” and some are becoming “energy positive” through a combination of energy efficiency measures and...

  7. Formation of anoxia and denitrification in the bottom waters of a tropical estuary, southwest coast of India.

    Digital Repository Service at National Institute of Oceanography (India)

    Martin, G.D.; Muraleedharan, K.R.; Vijay, J.G.; Rejomon, G.; Madhu, N.V.; Shivaprasad, A.; Haridevi, C.K.; Nair, M.; Balachandran, K.K.; Revichandran, C.; Jayalakshmy, K.V.; Chandramohanakumar, N.

    and makes the CBW system highly productive. Intrusion of AS waters seems to be stronger towards the upstream end (approx. 15 km), than had been previously reported, as a consequence of the lowering of river discharges and deepening of channels in the estuary...

  8. Copper ion fluxes through the floating water bridge under strong electric potential.

    Science.gov (United States)

    Giuliani, Livio; D'Emilia, Enrico; Lisi, Antonella; Grimaldi, Settimio; Brizhik, Larissa; Del Giudice, Emilio

    2015-01-01

    We have performed a series of experiments applying high voltage between two electrodes, immersed in two beakers containing bidistilled water in a way similar to experiments conducted by Fuchs and collaborators, which showed that a water bridge can be formed between the two containers. We also observed the formation of water bridge. Moreover, choosing different pairs of electrodes depending on the material they are made up of, we observed that copper ions flow can pass along the bridge if the negative electrode is made up of copper. We show that the direction of the flux not only depends on the applied electrostatic field but on the relative electronegativity of the electrodes too. These results open new perspectives in understanding the properties of water. We suggest a possible explanation of the obtained results.

  9. Pesticide concentrations in water and in suspended and bottom sediments in the New and Alamo rivers, Salton Sea Watershed, California, April 2003

    Science.gov (United States)

    LeBlanc, Lawrence A.; Orlando, James L.; Kuivila, Kathryn

    2004-01-01

    This report contains pesticide concentration data for water, and suspended and bed sediment samples collected in April 2003 from twelve sites along the New and Alamo Rivers in the Salton Sea watershed, in southeastern California. The study was done in collaboration with the California State Regional Water Quality Control Board, Colorado River Region, to assess inputs of current-use pesticides associated with water and sediment into the New and Alamo Rivers. Five sites along the New River and seven sites along the Alamo River, downstream of major agricultural drains, were selected and covered the lengths of the rivers from the international boundary to approximately 1.5 km from the river mouths. Sampling from bridges occurred at seven of the twelve sites. At these sites, streamflow measurements were taken. These same sites were also characterized for cross-stream homogeneity by measuring dissolved oxygen, pH, specific conductance, temperature, and suspended solids concentration at several vertical (depths) and horizontal (cross-stream) points across the river. Large volume water samples (200?300 L) were collected for isolation of suspended sediments by flow-through centrifugation. Water from the outflow of the flow-through centrifuge was sampled for the determination of aqueous pesticide concentrations. In addition, bottom sediments were sampled at each site. Current-use pesticides and legacy organochlorine compounds (p,p'-DDT, p,p'-DDE and p,p'-DDD) were extracted from sediments and measured via gas chromatography/mass spectrometry (GC/MS). Organic carbon and percentage of fines were also determined for suspended and bottom sediments. Cross-stream transects of dissolved constituents and suspended sediments showed that the rivers were fairly homogeneous at the sites sampled. Streamflow was higher at the outlet sites, with the Alamo River having higher flow (1,240 cfs) than the New River (798 cfs). Twelve current-use pesticides, one legacy organochlorine compound (p

  10. Connecting the surface to near-shore bottom waters in the California Current ecosystem: a study of Northern California interannual to decadal oceanographic variability

    Science.gov (United States)

    Fish, C.; Hill, T. M.; Davis, C. V.; Lipski, D.; Jahncke, J.

    2017-12-01

    Elucidating both surface and bottom water ecosystem impacts of temperature change, acidification, and food web disruption are needed to understand anthropogenic processes in the ocean. The Applied California Current Ecosystem Studies (ACCESS) partnership surveys the California Current within the Greater Farallones and Cordell Bank National Marine Sanctuaries three times annually, sampling water column hydrography and discrete water samples from 0 m and 200 m depth at five stations along three primary transects. The transects span the continental shelf with stations as close as 13 km from the coastline to 65 km. This time series extends from 2004 to 2017, integrating information on climate, productivity, zooplankton abundance, oxygenation, and carbonate chemistry. We focus on the interpretation of the 2012-2017 carbonate chemistry data and present both long term trends over the duration of the time series as well as shorter term variability (e.g., ENSO, `warm blob' conditions) to investigate the region's changing oceanographic conditions. For example, we document oscillations in carbonate chemistry, oxygenation, and foraminiferal abundance in concert with interannual oceanographic variability and seasonal (upwelling) cycles. We concentrate on results from near Cordell Bank that potentially impact deep sea coral ecosystems.

  11. Sensitivity of California water supply to changes in runoff magnitude and timing: A bottom-up assessment of vulnerabilities and adaptation strategies

    Science.gov (United States)

    Fefer, M.; Dogan, M. S.; Herman, J. D.

    2017-12-01

    Long-term shifts in the timing and magnitude of reservoir inflows will potentially have significant impacts on water supply reliability in California, though projections remain uncertain. Here we assess the vulnerability of the statewide system to changes in total annual runoff (a function of precipitation) and the fraction of runoff occurring during the winter months (primarily a function of temperature). An ensemble of scenarios is sampled using a bottom-up approach and compared to the most recent available streamflow projections from the state's 4th Climate Assessment. We evaluate these scenarios using a new open-source version of the CALVIN model, a network flow optimization model encompassing roughly 90% of the urban and agricultural water demands in California, which is capable of running scenario ensembles on a high-performance computing cluster. The economic representation of water demand in the model yields several advantages for this type of analysis: optimized reservoir operating policies to minimize shortage cost and the marginal value of adaptation opportunities, defined by shadow prices on infrastructure and regulatory constraints. Results indicate a shift in optimal reservoir operations and high marginal value of additional reservoir storage in the winter months. The collaborative management of reservoirs in CALVIN yields increased storage in downstream reservoirs to store the increased winter runoff. This study contributes an ensemble evaluation of a large-scale network model to investigate uncertain climate projections, and an approach to interpret the results of economic optimization through the lens of long-term adaptation strategies.

  12. Changes in bottom water conditions on the New Jersey paleoshelf during the Paleocene-Eocene Thermal Maximum (56 million years ago)

    Science.gov (United States)

    Park, J.; Makarova, M.; Miller, K. G.; Browning, J. V.; Wright, J. D.

    2016-12-01

    The goal of my study is to reconstruct bottom water conditions on the New Jersey paleoshelf during the Paleocene-Eocene Thermal Maximum (PETM) using stable isotopes on the Millville, NJ core. We analyzed tests (shells) of three benthic foraminiferal genera (Cibicidoides, Anomalinoides, and Gavelinella) for carbon (δ13C) and oxygen (δ18O) isotopes using mass spectrometry. Benthic foraminifera are unicellular organisms that live on the ocean floor and use calcium (Ca2+) and carbonate (CO32- ) ions to construct their tests. By doing this, they record the isotopic composition of carbon and oxygen in the seawater. The δ13C records show a sharp decrease of 3.5‰ across the PETM onset, marking the globally recognized carbon isotope excursion (CIE). Coupled benthic and planktonic (surface dwellers) carbon isotopic records indicate a 3‰ vertical gradient in the water column on the shelf. This is much higher than δ13C vertical gradients in the modern ocean (<2‰) and can be explained as evidence for more efficient cycling of organic carbon during the PETM. δ18O records of benthic foraminifera show a 2‰ decrease across the CIE onset, suggesting seafloor warming of 7-10°C (assuming all due to temperature). The change in δ18O of benthic foraminifera is much greater than in the sea surface recorded by surface dwellers (1‰ or 4°C assuming all due to temperature), implying reorganization of the water column on the shelf during the PETM.

  13. Isothiazolone Volatility Study of a Water Bottom from Fuel Treated with Kathon(trade name) FP1.5 Biocide

    Science.gov (United States)

    1993-11-01

    specific biocides was evaluated. Pure cultures of Hormonoconis resinae (previously Cladosporium resinae ), Yarrowia lipolytica and Pseudomonas...R.A., "Growth of Cladosporium resinae in Sea Water/Fuel Systems", Developments in Industrial Microbiology, 22, 781 (1981). 5 MacGregor C. and Devitt S...Contractor Report CR/87/431, (1987). 8 Hebda A.J. and Jones G.M., "Conditions and Modifications to Conditions for Growth of C. resinae in Canadian

  14. The Activation of Free Dipeptides Promoted by Strong Activating Agents in Water Does not Yield Diketopiperazines

    Science.gov (United States)

    Beaufils, Damien; Jepaul, Sandra; Liu, Ziwei; Boiteau, Laurent; Pascal, Robert

    2016-03-01

    The activation of dipeptides was studied in the perspective of the abiotic formation of oligopeptides of significant length as a requirement for secondary structure formation. The formation of piperazin-2,5-diones (DKP), previously considered as a dead end when activating free dipeptides, was shown in this work to be efficiently suppressed when using strong activating agents (e.g., carbodiimides). This behaviour was explained by the fast formation of a 5(4 H)-oxazolone intermediate at a rate that exceeds the time scale of the rotation of the peptide bond from the predominant trans-conformation into the cis-isomer required for DKP formation. No DKP was observed when using strong activating agents whereas phosphate mixed anhydrides or moderately activated esters were observed to predominantly yield DKP. The DKP side-reaction no longer constitutes a drawback for the C-terminus elongation of peptides. These results are considered as additional evidence that pathways involving strong activation are required to drive the emergence of living entities rather than close to equilibrium processes.

  15. Application of Confined Blasting in Water-Filled Deep Holes to Control Strong Rock Pressure in Hard Rock Mines

    Directory of Open Access Journals (Sweden)

    Jingxuan Yang

    2017-11-01

    Full Text Available In extra-thick coal seams, mining operations can lead to large-scale disturbances, complex overburden structures, and frequent and strong strata behavior in the stope, which are serious threats to mine safety. This study analyzed the overburden structure and strata behavior and proposed the technique of confined blasting in water-filled deep holes as a measure to prevent strong rock pressure. It found that there are two primary reasons for the high effectiveness of the proposed technique in presplitting hard coal and rock. First, the fracture water enables much more efficient transfer of dynamic load due to its incompressibility. Second, the subsequent expansion of water can further split the rock by compression. A mechanical model was used to reveal how the process of confined blasting in water-filled deep holes presplit roof. Moreover, practical implementation of this technique was found to improve the structure of hard, thick roof and prevent strong rock pressure, demonstrating its effectiveness in roof control.

  16. Processes controlling forms of phosphorus in surficial sediments from the eastern Arabian Sea impinged by varying bottom water oxygenation conditions

    Digital Repository Service at National Institute of Oceanography (India)

    PrakashBabu, C.; Nath, B.N.

    -axis at C2490ppm P org is similar to that of 70 and 60ppm found in other studies (Mach et al., 1987; De Lange, 1992). Mach et al. (1987) and de Lange (1992) have attributed to excess P org the experimental errorin estimating organic P.Partof inorganic-P may... is characterized by the presence of an intense oxygen minimum zone with denitrification in the water column (Naqvi, 1991, De Sousa et al., 1996). Nevertheless, relatively low P bio fraction is surprising (25–33%; Table 3), and sediments from this area deviate from...

  17. Model-Based Water Wall Fault Detection and Diagnosis of FBC Boiler Using Strong Tracking Filter

    Directory of Open Access Journals (Sweden)

    Li Sun

    2014-01-01

    Full Text Available Fluidized bed combustion (FBC boilers have received increasing attention in recent decades. The erosion issue on the water wall is one of the most common and serious faults for FBC boilers. Unlike direct measurement of tube thickness used by ultrasonic methods, the wastage of water wall is reconsidered equally as the variation of the overall heat transfer coefficient in the furnace. In this paper, a model-based approach is presented to estimate internal states and heat transfer coefficient dually from the noisy measurable outputs. The estimated parameter is compared with the normal value. Then the modified Bayesian algorithm is adopted for fault detection and diagnosis (FDD. The simulation results demonstrate that the approach is feasible and effective.

  18. Axisymmetric flow in a cylindrical tank over a rotating bottom. Part II. Deformation of the water surface and experimental verification of the theory

    Science.gov (United States)

    Iga, Keita; Yokota, Sho; Watanabe, Shunichi; Ikeda, Takashi; Niino, Hiroshi; Misawa, Nobuhiko

    2017-12-01

    The theory of axisymmetric flow in a cylindrical container with a rotating bottom, as described in Part I, is validated against the results of previous and our own laboratory experiments. First, deformation of the water surface is derived using the velocity distribution of the axisymmetric flow obtained by the theory. The form of the water surface is classified into three regimes, and the rotation rates of the transitions between these regimes are determined. The parameters predicted from this theory are compared with the results measured in laboratory experiments and also with data from previous experimental studies. The theory predicts the experimental data well, but a slight difference was found in the narrow region close to the side wall. Corrections estimated by considering the fluid behavior around the side wall boundary layer successfully explain most of the discrepancies. This theory appears to predict the results of the laboratory experiments very well, much better than a theory using an assumption of quadratic drag as a model of turbulent boundary layers.

  19. Occurrence of by-products of strong oxidants reacting with drinking water contaminants--scope of the problem.

    OpenAIRE

    Rice, R G; Gomez-Taylor, M

    1986-01-01

    This paper describes results of a detailed literature review of the organic and inorganic by-products that have been identified as being formed in aqueous solution with four of the strong oxidizing/disinfecting agents commonly employed in drinking water treatment. These agents are: chlorine, chlorine dioxide, chloramine, and ozone. Significant findings include the production of similar nonchlorinated organic oxidation products from chlorine, chlorine dioxide, and ozone. In addition, all three...

  20. Near-Bottom Hypoxia Impacts Dynamics of Bacterioplankton Assemblage throughout Water Column of the Gulf of Finland (Baltic Sea)

    Science.gov (United States)

    Laas, Peeter; Šatova, Elina; Lips, Inga; Lips, Urmas; Simm, Jaak; Kisand, Veljo; Metsis, Madis

    2016-01-01

    Over the past century the spread of hypoxia in the Baltic Sea has been drastic, reaching its ‘arm’ into the easternmost sub-basin, the Gulf of Finland. The hydrographic and climatological properties of the gulf offer a broad suite of discrete niches for microbial communities. The current study explores spatiotemporal dynamics of bacterioplankton community in the Gulf of Finland using massively parallel sequencing of 16S rRNA fragments obtained by amplifying community DNA from spring to autumn period. The presence of redoxcline and drastic seasonal changes make spatiotemporal dynamics of bacterioplankton community composition (BCC) and abundances in such estuary remarkably complex. To the best of our knowledge, this is the first study that analyses spatiotemporal dynamics of BCC in relation to phytoplankton bloom throughout the water column (and redoxcline), not only at the surface layer. We conclude that capability to survive (or benefit from) shifts between oxic and hypoxic conditions is vital adaptation for bacteria to thrive in such environments. Our results contribute to the understanding of emerging patterns in BCCs that occupy hydrographically similar estuaries dispersed all over the world, and we suggest the presence of a global redox- and salinity-driven metacommunity. These results have important implications for understanding long-term ecological and biogeochemical impacts of hypoxia expansion in the Baltic Sea (and similar ecosystems), as well as global biogeography of bacteria specialized inhabiting similar ecosystems. PMID:27213812

  1. Penggunaan Bottom Ash Sebagai Pengganti Agregat Halus Pada Mortar Hvfa

    OpenAIRE

    Sulistio, Aldi Vincent; Wahjudi, Samuel; Hardjito, Djwantoro; Antoni, Antoni

    2016-01-01

    Bottom ash adalah material limbah PLTU yang melimpah dan kurang dimanfaatkan. Terdapat potensi pemanfaatan bottom ash sebagai agregat halus dalam campuran beton. Dalam penelitian ini, bottom ash diberi treatment ayak dan tumbuk untuk digunakan sebagai pengganti pasir dalam campuran beton. Hal pertama yang dilakukan adalah pengujian karateristik fisik dan kimiawi dari bottom ash. Dilakukan pengujian water content, sieve analysis, fineness modulus, dan berat isi dari pasir dan bottom ash yang d...

  2. Concentration maxima of volatile organic iodine compounds in the bottom layer water and the cold, dense water over the Chukchi Sea in the western Arctic Ocean: a possibility of production related to degradation of organic matter

    Science.gov (United States)

    Ooki, A.; Kawasaki, S.; Kuma, K.; Nishino, S.; Kikuchi, T.

    2015-07-01

    We conducted a shipboard observation over the Chukchi Sea and the Canada Basin in the western Arctic Ocean in September and October 2012 to obtain vertical distributions of four volatile organic iodine compounds (VOIs) in seawater. VOIs are believed to play a role in ozone destruction in the troposphere and lower stratosphere. The VOIs observed in this study were iodomethane (CH3I), iodoethane (C2H5I), diiodomethane (CH2I2) and chloroiodomethane (CH2ClI). Maximum concentrations of the four VOIs were found in the bottom layer water over the Chukchi Sea shelf, in which layer the maximum concentration of ammonium (NH4+) also occurred. A significant correlation was observed between C2H5I and NH4+ (correlate coefficient R = 0.93) and between CH3I and NH4+ (R = 0.77), suggesting production of these VOIs increased with degradation of organic matter. Over the northern Chukchi Sea shelf-slope area, concentration maxima of CH2I2, CH2ClI, and CH3I were found in the subsurface cold, dense water (CDW). A large nitrogen deficit (N-deficit = NH4+ + NO3- + NO2- - 16PO43-) simultaneously occurred in this water, suggesting production of the three VOIs in the sediment or the bottom layer water over the shelf, probably in association with degradation of organic matter. We conclude that VOI production over the Chukchi Sea shelf can be largely attributed to the degradation of organic matter that is produced in the highly productive shelf water. High concentrations of CH2ClI were also found in the Alaskan Coastal Water (ACW) from the Bering Strait to the surface of the northern Chukchi slope. The VOIs that originated at the Chukchi Sea shelf are expected to be laterally transported to the Arctic Ocean Basin though the subsurface CDW and the surface ACW.

  3. Catch and post-release mortalities of deep-water sharks caught by bottom longlines in the Cantabrian Sea (NE Atlantic)

    Science.gov (United States)

    Rodríguez-Cabello, Cristina; Sánchez, Francisco

    2017-12-01

    The majority of deep-water fish have very low capacity to survive discarding as fishery bycatch due to their biological characteristics and adaptation to depth. This study explores the catch and post-release mortalities of several deep-water shark species caught by bottom longline in the El Cachucho (Le Danois Bank) MPA in northern Spanish waters (NE Atlantic). Survivorship was qualitatively evaluated according to health condition and responses of individuals after capture and subsequent release. A total of 15 species were caught, of which the most abundant were leafscale gulper shark Centrophorus squamosus (39%), birdbeak dogfish Deania calcea (39%) and Portuguese dogfish Centroscymnus coelolepis (10%). Catch or at-vessel mortality (AVM) for these species was lower than expected, 1.2%, 8.8% and 4.5%, respectively but 18.9%, 37.4% and 38.6% including both those specimens dead on retrieval and those scored in poor condition). The species with the highest vitality rate was C. squamosus (37.3% in good condition; 43.8% in moderate condition), followed by D. calcea (22.8% in good condition; 39.8% in moderate condition) and C. coelolepis (6.8% and 54.5%). Post-release mortality (PRM) was examined using electronic tags (PSATs, n = 14). Of the nine C. squamosus tagged successfully, three died within 5-10 weeks after release, whereas the other six survived for periods of at least 45-120 days, when tags were programmed to release). In the case of C. coelolepis, two of the four tagged specimens died almost immediately after release, whereas the other two tags indicated that the fish survived immediate release, but data were too limited to gauge survival due to tag failure.

  4. Observed bottom boundary layer transport and uplift on the continental shelf adjacent to a western boundary current

    Science.gov (United States)

    Schaeffer, A.; Roughan, M.; Wood, J. E.

    2014-08-01

    Western boundary currents strongly influence the dynamics on the adjacent continental shelf and in particular the cross-shelf transport and uplift through the bottom boundary layer. Four years of moored in situ observations on the narrow southeastern Australian shelf (in water depths of between 65 and 140 m) were used to investigate bottom cross-shelf transport, both upstream (30°S) and downstream (34°S) of the separation zone of the East Australian Current (EAC). Bottom transport was estimated and assessed against Ekman theory, showing consistent results for a number of different formulations of the boundary layer thickness. Net bottom cross-shelf transport was onshore at all locations. Ekman theory indicates that up to 64% of the transport variability is driven by the along-shelf bottom stress. Onshore transport in the bottom boundary layer was more intense and frequent upstream than downstream, occurring 64% of the time at 30°S. Wind-driven surface Ekman transport estimates did not balance the bottom cross-shelf flow. At both locations, strong variability was found in bottom water transport at periods of approximately 90-100 days. This corresponds with periodicity in EAC fluctuations and eddy shedding as evidenced from altimeter observations, highlighting the EAC as a driver of variability in the continental shelf waters. Ocean glider and HF radar observations were used to identify the bio-physical response to an EAC encroachment event, resulting in a strong onshore bottom flow, the uplift of cold slope water, and elevated coastal chlorophyll concentrations.

  5. Occurrence of by-products of strong oxidants reacting with drinking water contaminants--scope of the problem.

    Science.gov (United States)

    Rice, R G; Gomez-Taylor, M

    1986-11-01

    This paper describes results of a detailed literature review of the organic and inorganic by-products that have been identified as being formed in aqueous solution with four of the strong oxidizing/disinfecting agents commonly employed in drinking water treatment. These agents are: chlorine, chlorine dioxide, chloramine, and ozone. Significant findings include the production of similar nonchlorinated organic oxidation products from chlorine, chlorine dioxide, and ozone. In addition, all three chlorinous oxidants/disinfectants can produce chlorinated by-products under certain conditions. The presence of chloronitrile compounds in drinking waters is indicated to arise from reactions of chlorine or chloramine to amine/amide functions in amino acids or proteinaceous materials, followed by dehydrohalogenation. These nitriles could hydrolyze to produce the corresponding chloroacetic acids. It is concluded that to minimize the presence of oxidation by-products in drinking waters, the concentrations of oxidizable organic/inorganic impurities should be lowered before any oxidizing agent is added.

  6. Microscopic models for proton transfer in water and strongly hydrogen-bonded complexes with a single-well proton potential

    DEFF Research Database (Denmark)

    Kuznetsov, A.M.; Ulstrup, Jens

    2004-01-01

    A new mechanism and formalism for proton transfer in donor-acceptor complexes with long hydrogen bonds introduced recently [1], is applied to a proton transfer in liquid water. "Structural diffusion" of hydroxonium ions is regarded as totally adiabatic process, with synchronous hindered translation...... of two closest water molecules to and from the reaction complex as crucial steps. The water molecules induce a "gated" shift of the proton from the donor to the acceptor in the double-well potential with simultaneous breaking/formation of hydrogen bonds between these molecules and the proton donor...... and acceptor. The short-range and long-range proton transfer as "structural diffusion" of Zundel complexes is also considered. The theoretical formalism is illustrated with the use of Morse, exponential, and harmonic molecular potentials. This approach is extended to proton transfer in strongly hydrogen...

  7. Strong influence of vapor pressure deficit on plants' water-use efficiency: a modelling approach

    Science.gov (United States)

    Yi, K.; Zhang, Q.; Novick, K. A.

    2017-12-01

    The plant's trade-off between carbon uptake and water loss, which is often represented as intrinsic water-use efficiency (iWUE), is an important determinant of how plants will respond to expected changes in climate. Here, we present on work that assesses how the response of iWUE to the climatic drivers differs across the isohydricity spectrum, and to evaluate the relative influence of climatic drivers (vapor pressure deficit (D), soil moisture (θ), and atmospheric CO2 (ca)) on iWUE. The results suggested noticeable difference in the response of iWUE to climatic drivers among the species. The iWUE of the isohydric species, which tends to regulate stomata more actively, was more responsive to the variation of θ and D compared to the anisohydric species, of which stomata regulation is less active. Among the climatic drivers, D was the most influential driver on iWUE for all species. These results are consistent with those from a complementary effort to leverage long-term eddy covariance flux records from the FLUXNET 2015 database to compare the influence of D and θ on iWUE across a wide range of biomes; this analysis revealed that D is a more influential driver of iWUE than θ in the most cases. These findings highlight the importance of atmospheric dryness on trees' physiological response, which is important to understand given the large, global increases in D expected in coming decades. As a final step, we will report on early results to evaluate performance of widely-used ecosystem models in capturing the response of iWUE to climatic drivers across regions and to find out if the projection agrees well with flux tower observations. We also attempt to seek whether the relationship between iWUE and climatic drivers can be generalized for each vegetation type or climate regime.

  8. Some Durability Aspects of Ambient Cured Bottom Ash Geopolymer Concrete

    Directory of Open Access Journals (Sweden)

    Saravanakumar R.

    2017-09-01

    Full Text Available The present study examines some durability aspects of ambient cured bottom ash geopolymer concrete (BA GPC due to accelerated corrosion, sorptivity, and water absorption. The bottom ash geopolymer concrete was prepared with sodium based alkaline activators under ambient curing temperatures. The sodium hydroxide used concentration was 8M. The performance of BA GPC was compared with conventional concrete. The test results indicate that BA GPC developes a strong passive layer against chloride ion diffusion and provides better protection against corrosion. Both the initial and final rates of water absorption of BA GPC were about two times less than those of conventional concrete. The BA GPC significantly enhanced performance over equivalent grade conventional concrete (CC.

  9. Measurements of wave attenuation due to a soft bottom: The SWAMP experiment

    Science.gov (United States)

    Forristall, George Z.; Reece, Allan M.

    1985-03-01

    The Sea Wave Attenuation Measurement Program (SWAMP) was designed to provide measurements of the attenuation of waves as they travel from deep water to relatively shallow water off the Mississippi Delta. The soft bottom was suspected of causing strong attenuation in the area. This effect has now been measured. A wave staff and electromagnetic current meter were used to estimate directional wave spectra at the Cognac platform in 312 m (1025 feet) of water and at platform VV in South Pass Block 27 in 19 m (63 feet) of water. In addition, measurements of vertical bottom motion were made at platform VV. Seven storm periods from Sepember 1979 to February 1981 were studied. The directional spectral comparisons showed that the theoretically calculated refraction and shoaling can explain the changes in the spectra when the wave height is low. However, as the wave height increases, a nonlinear attenuation mechanism becomes increasingly strong. The attenuation is a strong function of deep-water wave height and a weak function of wave frequency. The bottom motion measurements showed that the bottom moved downward with small amplitude under wave crests.

  10. Effect of Strongly Alkaline Electrolyzed Water on Silk Degumming and the Physical Properties of the Fibroin Fiber.

    Directory of Open Access Journals (Sweden)

    Ting-Ting Cao

    Full Text Available Strongly alkaline electrolyzed water (SAEW was prepared by electrolysis of tap water in a laboratory-made water electrolyzer. The pH of stored SAEW was stable for more than one month. The hardness of the electrolyzed water was 30% lower and the Na(+ concentration was 18% higher than those of the tap water. Silkworm cocoon shells were boiled in pH 11.50 SAEW at a ratio of 1∶40∼80 (W/V for 20 min and the sericin layers around the silk fibroin fibers were removed completely. The tensile properties and thermal decomposition temperature of a single filament of silk fibroin obtained by the SAEW method were almost the same as those for the fiber obtained by the neutral soap, and much higher than those for the fiber obtained by Na2CO3 degumming. The results demonstrate that SAEW is an environmentally friendly and pollution-free silk degumming agent that allows highly efficient, low cost recovery of sericin.

  11. Effect of Strongly Alkaline Electrolyzed Water on Silk Degumming and the Physical Properties of the Fibroin Fiber.

    Science.gov (United States)

    Cao, Ting-Ting; Wang, Yuan-Jing; Zhang, Yu-Qing

    2013-01-01

    Strongly alkaline electrolyzed water (SAEW) was prepared by electrolysis of tap water in a laboratory-made water electrolyzer. The pH of stored SAEW was stable for more than one month. The hardness of the electrolyzed water was 30% lower and the Na(+) concentration was 18% higher than those of the tap water. Silkworm cocoon shells were boiled in pH 11.50 SAEW at a ratio of 1∶40∼80 (W/V) for 20 min and the sericin layers around the silk fibroin fibers were removed completely. The tensile properties and thermal decomposition temperature of a single filament of silk fibroin obtained by the SAEW method were almost the same as those for the fiber obtained by the neutral soap, and much higher than those for the fiber obtained by Na2CO3 degumming. The results demonstrate that SAEW is an environmentally friendly and pollution-free silk degumming agent that allows highly efficient, low cost recovery of sericin.

  12. Improving the success of bottom-up development work by acknowledging the dynamics among stakeholders: a case study from an Engineers Without Borders water supply project in Tenganan, Indonesia.

    Science.gov (United States)

    Bowen, J; Acciaioli, G

    2009-01-01

    This paper presents a model of development action synthesising the development arena framework with collective action theory. It shows how application of this model in the Engineers Without Borders Australia (EWB) water supply improvement and capacity building project in Tenganan, Indonesia has helped to maximise the extent to which the project practice can reflect the project rhetoric as "bottom-up" or community-inspired. The model posits a broad range of stakeholders actively engaged in development action: each stakeholder is different, with its own interests, missions, procedures, and ways of deploying power in development action. Recognising the multiplicity of subjects of development is especially crucial for improving bottom-up practice. Connections and interactions among stakeholders are inherently problematic, and must be negotiated to accomplish development work, as tensions in the dynamic among stakeholders may operate to restrict the success of these "bottom-up" development projects.

  13. Reconnaissance investigation of water quality, bottom sediment, and biota associated with irrigation drainage in the Owyhee and Vale Projects, Oregon and Idaho, 1990-91

    Science.gov (United States)

    Rinella, F.A.; Mullins, W.H.; Schuler, C.A.

    1994-01-01

    downstream manner. Constituent values at drainwater sites generally were comparable to concentrations below the irrigated ureas in the Owyhee and Vale project areas. The trace elements arsenic, boron, copper, molybdenum, vanadium, and zinc were detected in most water samples; cadmium, chromium, lead, and selenium were detected in some samples at concentrations generally near the analytical reporting limit; mercury was not detected in any samples. In some water samples, concentrations of arsenic, boron, cadmium, copper, and lead exceeded State or Federal water-quality standards or criteria. Most trace elements in bottom sediment were detected at concentrations within the expected 95-percent baseline range for soils from the Western United States. Concentrations that exceeded the 95-percent baseline range for study area soils were: (1) arsenic and lead in one sample from a site in the Vale project area; (2) mercury, lead, and tin in one sample from a site in the Snake River system; (3) manganese in two samples from two sites in the Snake River system; and (4) manganese from one sample from a site in the Vale project area. Fifteen pesticides and metabolites were detected in whole-water samples collected from sites in the study area. DDT, plus its metabolites (DDE and DDD), dieldrin, endrin, 2,4-D, dicamba, and dacthal were detected in samples collected from seven or more sites. Other pesticides detected included chlorpyrifos, endosulfan, ethion, malathion, parathion, phorate, and lindane. Most of the detected pesticide concentrations generally were largest in drainwater and at the most downstream sampling locations in the Owyhee and Vale project areas. Concentrations exceeded water-quality criteria established for the protection of freshwater aquatic life in 86 percent of the whole-water samples analyzed for DDT plus its metabolites, 71 percent of the dieldrin samples, 14 percent of the endrin samples, and 10 percent of the parathion samples. Eight pesticides and

  14. Model testing of radioactive contamination by {sup 90}Sr, {sup 137}Cs and {sup 239,240}Pu of water and bottom sediments in the Techa River (Southern Urals, Russia)

    Energy Technology Data Exchange (ETDEWEB)

    Kryshev, I.I. [Scientific and Production Association ' Typhoon' , 82 Lenin Ave., Obninsk, Kaluga Region, 249038 (Russian Federation)], E-mail: ecomod@obninsk.com; Boyer, P.; Monte, L.; Brittain, J.E.; Dzyuba, N.N.; Krylov, A.L.; Kryshev, A.I.; Nosov, A.V.; Sanina, K.D.; Zheleznyak, M.I. [Scientific and Production Association ' Typhoon' , 82 Lenin Ave., Obninsk, Kaluga Region, 249038 (Russian Federation)

    2009-03-15

    This paper presents results of testing models for the radioactive contamination of river water and bottom sediments by {sup 90}Sr, {sup 137}Cs and {sup 239,240}Pu. The scenario for the model testing was based on data from the Techa River (Southern Urals, Russia), which was contaminated as a result of discharges of liquid radioactive waste into the river. The endpoints of the scenario were model predictions of the activity concentrations of {sup 90}Sr, {sup 137}Cs and {sup 239,240}Pu in water and bottom sediments along the Techa River in 1996. Calculations for the Techa scenario were performed by six participant teams from France (model CASTEAUR), Italy (model MARTE), Russia (models TRANSFER-2, CASSANDRA, GIDRO-W) and Ukraine (model RIVTOX), all using different models. As a whole, the radionuclide predictions for {sup 90}Sr in water for all considered models, {sup 137}Cs for MARTE and TRANSFER-2, and {sup 239,240}Pu for TRANSFER-2 and CASSANDRA can be considered sufficiently reliable, whereas the prediction for sediments should be considered cautiously. At the same time the CASTEAUR and RIVTOX models estimate the activity concentrations of {sup 137}Cs and {sup 239,240}Pu in water more reliably than in bottom sediments. The models MARTE ({sup 239,240}Pu) and CASSANDRA ({sup 137}Cs) evaluated the activity concentrations of radionuclides in sediments with about the same agreement with observations as for water. For {sup 90}Sr and {sup 137}Cs the agreement between empirical data and model predictions was good, but not for all the observations of {sup 239,240}Pu in the river water-bottom sediment system. The modelling of {sup 239,240}Pu distribution proved difficult because, in contrast to {sup 137}Cs and {sup 90}Sr, most of models have not been previously tested or validated for plutonium.

  15. Flowable Backfill Materials from Bottom Ash for Underground Pipeline

    Directory of Open Access Journals (Sweden)

    Kyung-Joong Lee

    2014-04-01

    Full Text Available The purpose of this study was to investigate the relationship between strength and strain in manufacturing controlled low strength materials to recycle incineration bottom ash. Laboratory tests for controlled low strength materials with bottom ash and recycled in-situ soil have been carried out. The optimum mixing ratios were 25%–45% of in-situ soil, 30% of bottom ash, 10%–20% of fly ash, 0%–3% of crumb rubber, 3% of cement, and 22% of water. Each mixture satisfied the standard specifications: a minimum 20 cm of flowability and 127 kPa of unconfined compressive strength. The average secant modulus (E50 was (0.07–0.08 qu. The ranges of the internal friction angle and cohesion for mixtures were 36.5°–46.6° and 49.1–180 kPa, respectively. The pH of all of the mixtures was over 12, which is strongly alkaline. Small-scale chamber tests for controlled low strength materials with bottom ash and recycled in-situ soil have been carried out. Vertical deflection of 0.88–2.41 mm and horizontal deflection of 0.83–3.72 mm were measured during backfilling. The vertical and horizontal deflections of controlled low strength materials were smaller than that of sand backfill.

  16. Flowable Backfill Materials from Bottom Ash for Underground Pipeline.

    Science.gov (United States)

    Lee, Kyung-Joong; Kim, Seong-Kyum; Lee, Kwan-Ho

    2014-04-25

    The purpose of this study was to investigate the relationship between strength and strain in manufacturing controlled low strength materials to recycle incineration bottom ash. Laboratory tests for controlled low strength materials with bottom ash and recycled in-situ soil have been carried out. The optimum mixing ratios were 25%-45% of in-situ soil, 30% of bottom ash, 10%-20% of fly ash, 0%-3% of crumb rubber, 3% of cement, and 22% of water. Each mixture satisfied the standard specifications: a minimum 20 cm of flowability and 127 kPa of unconfined compressive strength. The average secant modulus ( E 50 ) was (0.07-0.08) q u . The ranges of the internal friction angle and cohesion for mixtures were 36.5°-46.6° and 49.1-180 kPa, respectively. The pH of all of the mixtures was over 12, which is strongly alkaline. Small-scale chamber tests for controlled low strength materials with bottom ash and recycled in-situ soil have been carried out. Vertical deflection of 0.88-2.41 mm and horizontal deflection of 0.83-3.72 mm were measured during backfilling. The vertical and horizontal deflections of controlled low strength materials were smaller than that of sand backfill.

  17. Evidence for carbon flux shortage and strong carbon/nitrogen interactions in pea nodules at early stages of water stress.

    Science.gov (United States)

    Gálvez, Loli; González, Esther M; Arrese-Igor, Cesar

    2005-09-01

    Symbiotic N2 fixation in legume nodules declines under a wide range of environmental stresses. A high correlation between N2 fixation decline and sucrose synthase (SS; EC 2.4.1.13) activity down-regulation has been reported, although it has still to be elucidated whether a causal relationship between SS activity down-regulation and N2 fixation decline can be established. In order to study the likely C/N interactions within nodules and the effects on N2 fixation, pea plants (Pisum sativum L. cv. Sugar snap) were subjected to progressive water stress by withholding irrigation. Under these conditions, nodule SS activity declined concomitantly with apparent nitrogenase activity. The levels of UDP-glucose, glucose-1-phosphate, glucose-6-phosphate, and fructose-6-phosphate decreased in water-stressed nodules compared with unstressed nodules. Drought also had a marked effect on nodule concentrations of malate, succinate, and alpha-ketoglutarate. Moreover, a general decline in nodule adenylate content was detected. NADP+-dependent isocitrate dehydrogenase (ICDH; EC 1.1.1.42) was the only enzyme whose activity increased as a result of water deficit, compensating for a possible C/N imbalance and/or supplying NADPH in circumstances that the pentose phosphate pathway was impaired, as suggested by the decline in glucose-6-phosphate dehydrogenase (G6PDH; EC 1.1.1.49) activity. The overall results show the occurrence of strong C/N interactions in nodules subjected to water stress and support a likely limitation of carbon flux that might be involved in the decline of N2 fixation under drought.

  18. Detachable strong cation exchange monolith, integrated with capillary zone electrophoresis and coupled with pH gradient elution, produces improved sensitivity and numbers of peptide identifications during bottom-up analysis of complex proteomes.

    Science.gov (United States)

    Zhang, Zhenbin; Yan, Xiaojing; Sun, Liangliang; Zhu, Guijie; Dovichi, Norman J

    2015-04-21

    A detachable sulfonate-silica hybrid strong cation-exchange monolith was synthesized in a fused silica capillary, and used for solid phase extraction with online pH gradient elution during capillary zone electrophoresis-tandem mass spectrometry (CZE-MS/MS) proteomic analysis. Tryptic digests were prepared in 50 mM formic acid and loaded onto the strong cation-exchange monolith. Fractions were eluted using a series of buffers with lower concentration but higher pH values than the 50 mM formic acid background electrolyte. This combination of elution and background electrolytes results in both sample stacking and formation of a dynamic pH junction and allows use of relatively large elution buffer volumes while maintaining reasonable peak efficiency and resolution. A series of five pH bumps were applied to elute E. coli tryptic peptides from the monolith, followed by analysis using CZE coupled to an LTQ-Orbitrap Velos mass spectrometer; 799 protein groups and 3381 peptides were identified from 50 ng of the digest in a 2.5 h analysis, which approaches the identification rate for this organism that was obtained with an Orbitrap Fusion. We attribute the improved numbers of peptide and protein identifications to the efficient fractionation by the online pH gradient elution, which decreased the complexity of the sample in each elution step and improved the signal intensity of low abundance peptides. We also performed a comparative analysis using a nanoACQUITY UltraPerformance LCH system. Similar numbers of protein and peptide identifications were produced by the two methods. Protein identifications showed significant overlap between the two methods, whereas peptide identifications were complementary.

  19. Detailed study of selenium in soil, water, bottom sediment, and biota in the Sun River Irrigation Project, Freezout Lake Wildlife Management Area, and Benton Lake National Wildlife Refuge, west-central Montana, 1990-92

    Science.gov (United States)

    Nimick, D.A.; Lambing, J.H.; Palawski, D.U.; Malloy, J.C.

    1996-01-01

    Selenium and other constituents are adversely affecting water quality and creating a potential hazard to wildlife in several areas of the Sun River Irrigation Project, Freezout Lake Wildlife Management Area, and Benton Lake National Wildlife Refuge in west-central Montana. Selenium derived from Cretaceous shale and Tertiary and Quaternary deposits containing shale detritus is transported in the oxic shallow ground-water systems. At Freezout Lake Wildlife Management Area, drainage from irrigated glacial deposits is the primary source of selenium; drainage from non-irrigated farmland is a significant source locally. Benton Lake generally receives more selenium from natural runoff from its non-irrigated basin than from the trans-basin diversion of irrigation return flow. Selenium has accumulated in aquatic plants and invertebrates, fish, and water birds, particularly in wetlands that receive the largest selenium loads. Although selenium residues in biological tissue from some wetland units exceeded biological risk levels, water-bird reproduction generally has not been impaired. The highest selenium residues in biota commonly occurred in samples from Priest Butte Lakes, which also had the highest selenium concentration in wetland water. Selenium concentrations in all invertebrate samples from Priest Butte Lakes and the south end of Freezeout Lake exceeded the critical dietary threshold for water birds. Selenium delivered to wetlands accumulates in bottom sediment, predominantly in near-shore areas. Potential impacts to water quality, and presumably biota, may be greatest near the mouths of inflows. Most selenium delivered to wetlands will continue to accumulate in bottom sediment and biota.

  20. Water-Soluble Polymers with Strong Photoluminescence through an Eco-Friendly and Low-Cost Route.

    Science.gov (United States)

    Guo, Zhaoyan; Ru, Yue; Song, Wenbo; Liu, Zhenjie; Zhang, Xiaohong; Qiao, Jinliang

    2017-07-01

    Photoluminescence (PL) of nonconjugated polymers brings a favorable opportunity for low-cost and nontoxic luminescent materials, while most of them still exhibit relatively weak emission. Strong PL from poly[(maleic anhydride)-alt-(vinyl acetate)] (PMV) from low-cost monomer has been found in organic solvents, yet the necessity of noxious solvents would hinder its practical applications. Herein, through a novel, eco-friendly, and one-step route, PMV-derived PL polymers can be fabricated with the highest quantum yield of 87% among water-soluble nonconjugated PL polymers ever reported. These PMV-derived polymers emit strong blue emission in both solutions and solids, and can be transformed into red-emission agents easily. These PL polymers exhibit application potentials in light-conversion agricultural films. It is assumed that this work not only puts forward a convenient preparation routine for nonconjugated polymers with high PL, but also provides an industrial application possibility for them. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. The Bottom Boundary Layer

    Science.gov (United States)

    Trowbridge, John H.; Lentz, Steven J.

    2018-01-01

    The oceanic bottom boundary layer extracts energy and momentum from the overlying flow, mediates the fate of near-bottom substances, and generates bedforms that retard the flow and affect benthic processes. The bottom boundary layer is forced by winds, waves, tides, and buoyancy and is influenced by surface waves, internal waves, and stratification by heat, salt, and suspended sediments. This review focuses on the coastal ocean. The main points are that (a) classical turbulence concepts and modern turbulence parameterizations provide accurate representations of the structure and turbulent fluxes under conditions in which the underlying assumptions hold, (b) modern sensors and analyses enable high-quality direct or near-direct measurements of the turbulent fluxes and dissipation rates, and (c) the remaining challenges include the interaction of waves and currents with the erodible seabed, the impact of layer-scale two- and three-dimensional instabilities, and the role of the bottom boundary layer in shelf-slope exchange.

  2. Spring Bottom Trawl Survey

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The standardized NEFSC Spring Bottom Trawl Survey was initiated in 1968 and covered an area from Cape Hatteras, NC, to Nova Scotia, Canada, at depths >27m....

  3. Winter Bottom Trawl Survey

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The standardized NEFSC Winter Bottom Trawl Survey was initiated in 1992 and covered offshore areas from the Mid-Atlantic to Georges Bank. Inshore strata were covered...

  4. Fall Bottom Trawl Survey

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The standardized NEFSC Fall Bottom Trawl Survey was initiated in 1963 and covered an area from Hudson Canyon, NY to Nova Scotia, Canada. Throughout the years,...

  5. Energy and Water Conservation: Techniques to Reduce Waste and Improve the Budgetary Bottom Line. IssueTrak: A CEFPI Brief on Educational Facility Issues

    Science.gov (United States)

    Peterson, David J.

    2004-01-01

    This "IssueTrak" discusses how saving energy and becoming energy efficient may significantly impact a school district's bottom line as well as simply being the right thing to do. There are many opportunities to conserve that can be implemented at little or no cost. To be successful, a school district must allow employees to gather data, analyze…

  6. Stick-Jump (SJ) Evaporation of Strongly Pinned Nanoliter Volume Sessile Water Droplets on Quick Drying, Micropatterned Surfaces.

    Science.gov (United States)

    Debuisson, Damien; Merlen, Alain; Senez, Vincent; Arscott, Steve

    2016-03-22

    We present an experimental study of stick-jump (SJ) evaporation of strongly pinned nanoliter volume sessile water droplets drying on micropatterned surfaces. The evaporation is studied on surfaces composed of photolithographically micropatterned negative photoresist (SU-8). The micropatterning of the SU-8 enables circular, smooth, trough-like features to be formed which causes a very strong pinning of the three phase (liquid-vapor-solid) contact line of an evaporating droplet. This is ideal for studying SJ evaporation as it contains sequential constant contact radius (CCR) evaporation phases during droplet evaporation. The evaporation was studied in nonconfined conditions, and forced convection was not used. Micropatterned concentric circles were defined having an initial radius of 1000 μm decreasing by a spacing ranging from 500 to 50 μm. The droplet evaporates, successively pinning and depinning from circle to circle. For each pinning radius, the droplet contact angle and volume are observed to decrease quasi-linearly with time. The experimental average evaporation rates were found to decrease with decreasing pining radii. In contrast, the experimental average evaporation flux is found to increase with decreasing droplet radii. The data also demonstrate the influence of the initial contact angle on evaporation rate and flux. The data indicate that the total evaporation time of a droplet depends on the specific micropattern spacing and that the total evaporation time on micropatterned surfaces is always less than on flat, homogeneous surfaces. Although the surface patterning is observed to have little effect on the average droplet flux-indicating that the underlying evaporation physics is not significantly changed by the patterning-the total evaporation time is considerably modified by patterning, up to a factor or almost 2 compared to evaporation on a flat, homogeneous surface. The closely spaced concentric circle pinning maintains a large droplet radius and

  7. CALCULATION AND ANALYSIS OF THE EXPECTED IMPACT OF THE HYDROTECHNICAL CONSTRUCTION ON THE ENVIRONMENTAL CONDITION IN THE WATER AREA AND BOTTOM TOPOGRAPHY IN CASE OF THE CONSTRUCTION OF THE APPROACH CHANNEL TO THE SABETTA PORT

    Directory of Open Access Journals (Sweden)

    Vvedensky Alexei Rostislavovich

    2017-05-01

    Full Text Available The estimation of changes in the ecological situation and bottom topography in the Ob Bay, which may be caused by the construction of the approach channel to the port of Sabetta, was carried out with the help of the developed complex of numerical models. Particular attention was paid to the study of the displacement of the boundaries of the saline water expansion and the sediment accumulation in the channel area. It is established that the possible influence of the approach channel on the hydrologic-hydrochemical characteristics is less than their natural interannual and seasonal variability in the investigated water area. The change in the bottom topography after the construction of the approach channel does not entail a significant change in the regime of hydrologic-hydrochemical parameters of the Ob Bay and, consequently, should not affect the biocenosis. The calculated changes in the bottom topography in the approach channel area will not exceed 2 % of the depth per year and will not become a significant obstacle to the reliable and uninterrupted operation of the Sabetta port.

  8. Pipeline bottoming cycle study. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1980-06-01

    The technical and economic feasibility of applying bottoming cycles to the prime movers that drive the compressors of natural gas pipelines was studied. These bottoming cycles convert some of the waste heat from the exhaust gas of the prime movers into shaft power and conserve gas. Three typical compressor station sites were selected, each on a different pipeline. Although the prime movers were different, they were similar enough in exhaust gas flow rate and temperature that a single bottoming cycle system could be designed, with some modifications, for all three sites. Preliminary design included selection of the bottoming cycle working fluid, optimization of the cycle, and design of the components, such as turbine, vapor generator and condensers. Installation drawings were made and hardware and installation costs were estimated. The results of the economic assessment of retrofitting bottoming cycle systems on the three selected sites indicated that profitability was strongly dependent upon the site-specific installation costs, how the energy was used and the yearly utilization of the apparatus. The study indicated that the bottoming cycles are a competitive investment alternative for certain applications for the pipeline industry. Bottoming cycles are technically feasible. It was concluded that proper design and operating practices would reduce the environmental and safety hazards to acceptable levels. The amount of gas that could be saved through the year 2000 by the adoption of bottoming cycles for two different supply projections was estimated as from 0.296 trillion ft/sup 3/ for a low supply projection to 0.734 trillion ft/sup 3/ for a high supply projection. The potential market for bottoming cycle equipment for the two supply projections varied from 170 to 500 units of varying size. Finally, a demonstration program plan was developed.

  9. Charmed Bottom Baryon Spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Zachary S; Detmold, William; Meinel, Stefan; Orginos, Kostas

    2014-11-01

    The spectrum of doubly and triply heavy baryons remains experimentally unexplored to a large extent. Although the detection of such heavy particle states may lie beyond the reach of exper- iments for some time, it is interesting compute this spectrum from QCD and compare results between lattice calculations and continuum theoretical models. Several lattice calculations ex- ist for both doubly and triply charmed as well as doubly and triply bottom baryons. Here, we present preliminary results from the first lattice calculation of doubly and triply heavy baryons including both charm and bottom quarks. We use domain wall fermions for 2+1 flavors (up down and strange) of sea and valence quarks, a relativistic heavy quark action for the charm quarks, and non-relativistic QCD for the heavier bottom quarks. We present preliminary results for the ground state spectrum.

  10. Bottom-linked innovation

    DEFF Research Database (Denmark)

    Kristensen, Catharina Juul

    2018-01-01

    Employee-driven innovation is gaining ground as a strategy for developing sustainable organisations in the public and private sector. This type of innovation is characterised by active employee participation, and the bottom-up perspective is often emphasised. This article explores an issue that has...... hitherto been paid little explicit attention, namely collaboration between middle managers and employees in innovation processes. In contrast to most studies, middle managers and employees are here both subjects of explicit investigation. The collaboration processes explored in this article are termed...... ‘bottom-linked innovation’. The empirical analysis is based on an in-depth qualitative study of bottom-linked innovation in a public frontline institution in Denmark. By combining research on employee-driven innovation and middle management, the article offers new insights into such collaborative...

  11. Change in the Nd isotopic composition of the bottom water and detrital sediments on the Bering Slope over the last 500 kyrs with implications for the formation of the North Pacific Intermediate Water

    Science.gov (United States)

    Jang, K.; Huh, Y.; Han, Y.

    2015-12-01

    The Bering Sea is a potential location for the formation of the North Pacific Intermediate/Deep Water (NPIW/NPDW) and may play an important role in the global heat distribution. We reconstructed the neodymium isotopic ratio (ɛNd) of authigenic Fe-Mn oxide coatings and detrital sediments on the Bering Slope (IODP Expedition 323 site U1345; water depth 1008 m) over the last 500 kyrs. The ɛNd is a quasi-conservative water mass tracer. We compared three different leaching techniques to assure that authigenic signals are captured without contamination from terrigenous sources: (1) leaching (3 hours) with 0.02 M hydroxylamine hydrochloride (HH) in 25% buffered acetic acid after decarbonation; sediment/solution (v/v) > 10, (2) leaching (1 hour) with 0.02 M HH in 25% buffered acetic acid without decarbonation; sediment/solution ~ 1, and (3) leaching (1 hour) with 0.005 M HH in 1.5% buffered acetic acid-0.003 M Na-EDTA without decarbonation; sediment/solution > 40. The low Al concentrations and less radiogenic ɛNdvalues indicated that method (2) is the most appropriate leaching process. The average ɛNd of the authigenic fraction over the last 500 kyrs is -3.3 ± 0.9 (1σ, n=38), with large temporal fluctuations. The ɛNd of authigenic and detrital fractions are well correlated (r2 ~ 0.66), suggesting that the bottom water composition in the Bering Sea was governed by terrigenous inflow from surrounding areas. Radiogenic ɛNd peaks (up to -1.9) seem to be influenced by radiogenic water inflow from the the Kamchatka or Aluetian arcs. The high bulk density and low b* values imply higher terrigenous versus biological contribution and enhanced sea ice formation. Subsequent brine formation would have triggered sinking of radiogenic surface water, forming the NPIW. On the other hand, non-radiogenic ɛNd troughs (down to -5.3) are observed at times of low bulk density and high b* values. We presume higher biological productivity which is supported by the high opal content at

  12. The ecological effects of water level fluctuation and phosphate enrichment in mesotrophic peatlands are strongly mediated by soil chemistry

    NARCIS (Netherlands)

    Mettrop, I.S.; Rutte, M.D.; Kooijman, A.M.; Lamers, L.P.M.

    2015-01-01

    Since the re-establishment of a more natural water regime is considered by water management in wetlands with artificially stable water levels, the biogeochemical and ecological effects of water level fluctuation with different nutrient loads should be investigated. This is particularly important for

  13. Monitoring of metals in Tilapia nilotica tissues, bottom sediments ...

    African Journals Online (AJOL)

    Tilapia (Tilapia nilotica), bottom sediments and water were collected from Nworie River and Oguta Lake. The muscle, liver and gills of the fish as well as the bottom sediments and water were analysed for Al, Cr, Cd, Pb, As, Zn, Mn, Co, Se, Cu, Ni and Fe using atomic absorption spectrophotometer to highlight the importance ...

  14. Bottom and top physics

    International Nuclear Information System (INIS)

    Foley, K.J.; Fridman, A.; Gilman, F.J.; Herten, G.; Hinchliffe, I.; Jawahery, A.; Sanda, A.; Schmidt, M.P.; Schubert, K.R.

    1987-09-01

    The production of bottom quarks at the SSC and the formalism and phenomenology of observing CP violation in B meson decays is discussed. The production of a heavy t quark which decays into a real W boson, and what we might learn from its decays is examined

  15. Reconnaissance investigation of water quality, bottom sediment, and biota associated with irrigation drainage in Bowdoin National Wildlife Refuge and adjacent areas of the Milk River basin, northeastern Montana, 1986-87

    Science.gov (United States)

    Lambing, J.H.; Jones, W.E.; Sutphin, J.W.

    1988-01-01

    Concentrations of trace elements, radiochemicals, and pesticides in the Bowdoin National Wildlife Refuge lakes generally were not substantially larger than those in the water supplied from Dodson South Canal or in irrigation drainage. Concentrations of arsenic (47 micrograms/L), uranium (43 microg/L), and vanadium (51 microg/L) in Dry Lake Unit, and boron (1,000 microg/L) in Lake Bowdoin were notably larger than at other sites. Zinc concentrations in an irrigation drain (56 microg/L) and two shallow domestic wells (40 and 47 microg/L) were elevated relative to other sites. Concentrations of gross alpha radiation (64 picocuries/L) and gross beta radiation (71 picocuries/L) were elevated in Dry Lake Unit. Pesticides concentrations at all sites were 0.08 microg/L or less. Water use guidelines concentrations for boron, cadmium, uranium, zinc, and gross alpha radiation were slightly exceeded at several sites. In general, trace-constituent concentrations measured in the water do not indicate any potential toxicity problems in Bowdoin National Wildlife Refuge; however, highwater conditions in 1986 probably caused dilution of dissolved constituents compared to recent dry years. Trace element concentrations in bottom sediments of the refuge lakes were generally similar to background concentrations in the soils. The only exception was Dry Lake Unit, which had concentrations of chromium (99 micrograms/g), copper (37 microg/g), nickel (37 microg/g), vanadium (160 microg/g), and zinc (120 microg/g) that were about double the mean background concentrations. The maximum selenium concentration in bottom sediment was 0.6 microg/g. Pesticide concentrations in bottom sediments were less than analytical detection limits at all sites. With few exceptions, concentrations of trace elements and pesticides in biota generally were less than values known to produce harmful effects on growth or reproduction. (Lantz-PTT)

  16. Effects of bottom water oxygen concentrations on mercury distribution and speciation in sediments below the oxygen minimum zone of the Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Chakraborty, P.; Mason, R.P.; Jayachandran, S.; Vudamala, K.; Armoury, K.; Sarkar, Arindam; Chakraborty, S.; Bardhan, P.; Naik, R.

    and degradation in aquatic ecosystems. In ACS symposium series (Vol. 835, pp. 262-297). Washington, DC; Am. Chem. S.; 1999. Bordovsky, O.K., 1965. Accumulation of organic matter in bottom sediments. Mar. Geol. 3, 33–82. Botsford, L. W., Castilla, J. C...., Peterson, C. H., 1997. The management of fisheries and marine ecosystems. Science, 277 (5325), 509-515. Broenkow, W.W. and Cline, J.D., 1969. Colorimetric determination of dissolved oxygen at low concentrations. Limnol. Oceanogr. 14(3), 450-454. Bryan...

  17. Sea spray production by bag breakup mode of fragmentation of the air-water interface at strong and hurricane wind

    Science.gov (United States)

    Troitskaya, Yuliya; Kandaurov, Alexander; Ermakova, Olga; Kozlov, Dmitry; Sergeev, Daniil; Zilitinkevich, Sergej

    2016-04-01

    Sea sprays is a typical element of the marine atmospheric boundary layer (MABL) of large importance for marine meteorology, atmospheric chemistry and climate studies. They are considered as a crucial factor in the development of hurricanes and severe extratropical storms, since they can significantly enhance exchange of mass, heat and momentum between the ocean and the atmosphere. This exchange is directly provided by spume droplets with the sizes from 10 microns to a few millimeters mechanically torn off the crests of a breaking waves and fall down to the ocean due to gravity. The fluxes associated with the spray are determined by the rate of droplet production at the surface quantified by the sea spray generation function (SSGF), defined as the number of spray particles of radius r produced from the unit area of water surface in unit time. However, the mechanism of spume droplets' formation is unknown and empirical estimates of SSGF varied over six orders of magnitude; therefore, the production rate of large sea spray droplets is not adequately described and there are significant uncertainties in estimations of exchange processes in hurricanes. Experimental core of our work comprise laboratory experiments employing high-speed video-filming, which have made it possible to disclose how water surface looks like at extremely strong winds and how exactly droplets are torn off wave crests. We classified events responsible for spume droplet, including bursting of submerged bubbles, generation and breakup of "projections" or liquid filaments (Koa, 1981) and "bag breakup", namely, inflating and consequent blowing of short-lived, sail-like pieces of the water-surface film, "bags". The process is similar to "bag-breakup" mode of fragmentation of liquid droplets and jets in gaseous flows. Basing on statistical analysis of results of these experiments we show that the main mechanism of spray-generation is attributed to "bag-breakup mechanism On the base of general principles

  18. Role of the bottom sediments immediately beneath the lake water-groundwater interface in the transport and removal of cyanobacteria, cyanophage, and dissolved organic carbon during natural lake-bank filtration at a kettle pond subject to harmful algal blooms

    Science.gov (United States)

    Harvey, R. W.; Metge, D. W.; LeBlanc, D. R.; Underwood, J. C.; Aiken, G.; McCobb, T. D.; Jasperse, J.

    2015-12-01

    Bank filtration has proven to be a sustainable, cost-effective method of removing cyanobacteria and their harmful toxins from surface water during filtration through bottom and aquifer sediments. The biologically active layer of sediments immediately beneath the sediment-water interface (colmation layer) is believed to be particularly important in this process. An in situ experiment was conducted that involved assessing the transport behaviors of bromide (conservative tracer), Synechococcus sp. IU625 (cyanobacterium, 2.6 ± 0.2 µm), AS-1 (tailed cyanophages, 110 nm long), MS2 (coliphages, 26 nm diameter), and carboxylate-modified microspheres (1.7 µm diameter) introduced to the colmation layer using a bag-and-barrel (Lee-type) seepage meter. The constituents were monitored as they advected through the colmation layer and underlying aquifer sediments at Ashumet Pond in Cape Cod, MA, a mesotrophic kettle pond that recharges a portion of a sole-source, drinking water aquifer. Because the pond DOC includes the various cyanotoxins produced during harmful algal bloom senescence, the DOC and aforementioned colloids were tracked concomitantly. The tracer test constituents were monitored as they advected across the pond water-groundwater interface and through the underlying aquifer sediments under natural-gradient conditions past push-points samplers placed at ~30-cm intervals along a 1.2-m-long, diagonally downward flow path. More than 99% of the microspheres, IU625, MS2, AS-1, and ~42% of the pond DOC were removed in the colmation layer (upper 25 cm of poorly sorted bottom sediments) at two test locations characterized by dissimilar seepage rates (1.7 vs. 0.26 m d-1). Retention profiles in recovered core material indicated that >82% of the attached IU625 were in the top 3 cm of bottom sediments. The colmation layer was also responsible for rapid changes in the character of the DOC and was more effective (by 3 orders of magnitude) at removing microspheres than was the

  19. Seabed morphology and bottom water masses related to benthic habitats at the Cristóbal Colón diapir (NW of the Guadalquivir ridge, Gulf of Cádiz)

    OpenAIRE

    Palomino, D. (Desirée); Vázquez-Garrido, J.T. (Juan Tomás); Rueda, J.L. (José Luis); Fernández-Salas, L.M. (Luis Miguel); López-González, N. (Nieves); Díaz-del-Río-Español, V. (Víctor)

    2014-01-01

    The seabed morphology and the sub-superficial characteristics of the Cristóbal Colón diapir located on the continental slope of the Gulf of Cadiz have been analysed from data obtained in the framework of the LIFE+INDEMARES/CHICA project. The aim of this study is to recognize the morphological features and the geological processes generated by the bottom water masses and their influence on the habitats and associated benthic communities. The NACW affects the generation of morpho...

  20. Investigation of the tritium content in surface water, bottom sediments (zoobenthos), macrophytes, and fish in the mid-stream region of the Yenisei River (Siberia, Russia).

    Science.gov (United States)

    Bondareva, Lydia; Schultz, Michael K

    2015-11-01

    The potential sources of tritium input to the Yenisei River ecosystem are derived from local operations of nuclear facilities of the Mining and Chemical Combine operated by the state-owned Rosatom corporation and from sources derived from global weapons testing fallout and nuclear power. The background tritium concentrations in zoobenthos, bottom sediments, relevant commercial fish species, and widespread endogenous aquatic plants have been obtained for the first time in this region. Our results demonstrate that the major input term of tritium to this region of the Yenisei is derived from nearby mining operations of Rosatom, with tritium concentrations in aquatic plants marginally exceeding the observed background values obtained from upstream control sample collection sites.

  1. Between Soft Legality and Strong Legitimacy : A Political Economy Approach to the Struggle for Basic Entitlements to Safe Water and Sanitation

    NARCIS (Netherlands)

    de Gaay Fortman, B.|info:eu-repo/dai/nl/068346581; Marcatelli, M.

    This article argues that the internationally declared “human right to safe water and sanitation,” although characterized by soft legality, may yet support universal access to such basic entitlements by virtue of its strong legitimacy. From a strategic perspective, human rights do indeed provide

  2. Strong linkages between surface and deep-water dissolved organic matter in the East/Japan Sea

    Science.gov (United States)

    Kim, Tae-Hoon; Kim, Guebuem; Shen, Yuan; Benner, Ronald

    2017-05-01

    Vertical and horizontal distributions of total dissolved amino acids (TDAAs), dissolved organic carbon (DOC), and dissolved organic nitrogen (DON) were measured in the East/Japan Sea (EJS). The euphotic zone of this sea is N-limited, and the N : P ratio is ˜ 13 below 200 m depth. Elevated TDAA concentrations (137 ± 34 nM) and DOC-normalized yields (0.8 ± 0.2 % of DOC) were observed in deep waters ( ≥ 1000 m) of the EJS and compared with those in the deep North Pacific Ocean. Significantly high TDAA concentrations and yields were observed in a region of deep-water formation, indicating the convection of margin-derived bioavailable dissolved organic matter (DOM) to deep waters. Declining TDAA concentrations (36 ± 12 %) and yields (33 ± 13 %) were observed between 1000 and 3000 m throughout the EJS, indicating the utilization of bioavailable DOM in deep waters. Concentrations of the D-enantiomers of amino acids (Ala, Glx, Asx, and Ser) were relatively high in deep waters of the EJS, indicating substantial bacterial contributions to DOM from surface and upper mesopelagic waters. Climate warming during the past few decades in the EJS is weakening deep convection during the winter, and one consequence of this reduction in deep convection is a decline in the supply of bioavailable DOM from surface waters.

  3. Methods of analysis by the U.S. Geological Survey National Water Quality Laboratory; determination of semivolatile organic compounds in bottom sediment by solvent extraction, gel permeation chromatographic fractionation, and capillary-column gas chromatography/mass spectrometry

    Science.gov (United States)

    Furlong, E.T.; Vaught, D.G.; Merten, L.M.; Foreman, W.T.; Gates, Paul M.

    1996-01-01

    A method for the determination of 79 semivolatile organic compounds (SOCs) and 4 surrogate compounds in soils and bottom sediment is described. The SOCs are extracted from bottom sediment by solvent extraction, followed by partial isolation using high-performance gel permeation chromatography (GPC). The SOCs then are qualitatively identified and quantitative concentrations determined by capillary-column gas chromatography/mass spectrometry (GC/MS). This method also is designed for an optional simultaneous isolation of polychlorinated biphenyls (PCBs) and organochlorine (OC) insecticides, including toxaphene. When OCs and PCBs are determined, an additional alumina- over-silica column chromatography step follows GPC cleanup, and quantitation is by dual capillary- column gas chromatography with electron-capture detection (GC/ECD). Bottom-sediment samples are centrifuged to remove excess water and extracted overnight with dichloromethane. The extract is concentrated, centrifuged, and then filtered through a 0.2-micrometer polytetrafluoro-ethylene syringe filter. Two aliquots of the sample extract then are quantitatively injected onto two polystyrene- divinylbenzene GPC columns connected in series. The SOCs are eluted with dichloromethane, a fraction containing the SOCs is collected, and some coextracted interferences, including elemental sulfur, are separated and discarded. The SOC-containing GPC fraction then is analyzed by GC/MS. When desired, a second aliquot from GPC is further processed for OCs and PCBs by combined alumina-over-silica column chromatography. The two fractions produced in this cleanup then are analyzed by GC/ECD. This report fully describes and is limited to the determination of SOCs by GC/MS.

  4. Characterization of bottom sediments in lakes using hydroacoustic methods and comparison with laboratory measurements.

    Science.gov (United States)

    Anderson, Michael A; Pacheco, Porfirio

    2011-10-01

    The acoustical properties of bottom sediments in two lakes were shown to be strongly correlated with clay content, organic C and total N concentrations, and other important sediment properties. The fractal dimension of the bottom echo was more strongly correlated with sediment physical and chemical properties than energy-based measures. The fractal dimension was also related to rates of PO4-P and NH4-N release from intact sediment cores and sediment oxygen demand. Measurements made at 430-kHz were more sensitive to differences in sediment properties than 201- or 38-kHz. Hydroacoustic measurements allow rapid assessment of properties important in lake restoration and water resource management. Copyright © 2011 Elsevier Ltd. All rights reserved.

  5. Ocean bottom seismometer technology

    Science.gov (United States)

    Prothero, William A., Jr.

    Seismometers have been placed on the ocean bottom for about 45 years, beginning with the work of Ewing and Vine [1938], and their current use to measure signals from earthquakes and explosions constitutes an important research method for seismological studies. Approximately 20 research groups are active in the United Kingdom, France, West Germany, Japan, Canada, and the United States. A review of ocean bottom seismometer (OBS) instrument characteristics and OBS scientific studies may be found in Whitmarsh and Lilwall [1984]. OBS instrumentation is also important for land seismology. The recording systems that have been developed have been generally more sophisticated than those available for land use, and several modern land seismic recording systems are based on OBS recording system designs.The instrumentation developed for OBS work was the topic of a meeting held at the University of California, Santa Barbara, in July 1982. This article will discuss the state of the art of OBS Technology, some of the problems remaining to be solved, and some of the solutions proposed and implemented by OBS scientists and engineers. It is not intended as a comprehensive review of existing instrumentation.

  6. Thermodynamic evaluation of the impact of strongly swelling polymer hydrogels with ionic silver on the water retention capacity of sandy substrate

    Science.gov (United States)

    Smagin, A. V.

    2017-01-01

    The impact of two types of strongly swelling polymer hydrogel (SSPH) on the water retention capacity of quartz sand in pure water and Ag+ solutions (10-100 mg/l) has been studied by using a centrifugation method in a wide range of thermodynamic water potential (Gibbs energy) from 0 to 3030 J/kg. The experimental data for the water retention curves (WRC) were estimated by the van Genuchten model. Both hydrogels - the Aquasorb preparation (Germany) with hydrophilic properties and high degree of swelling in pure water (700-1000 g H2O/g) and the new Russian amphiphilic SSPH with a peat filler (degree of swelling 500-700 g H2O/g) were very effective as water adsorbing soil conditioners in relatively small doses from 0.05 to 0.3% per mass of dry (105°C) soil substrate. The water retention capacity of sandy substrate increases under the influence of SSPH with 2-3 times up to the level of native loamy sands and loams. Adding Ag+ to the water solution results just for the highest concentration of SSPH (0.3%) and iconic silver (100 mg/l) in a significant decrease of the water retention in the soil-gel compositions.

  7. Strong low-pass filtering effects on water vapour flux measurements with closed-path eddy correlation systems

    DEFF Research Database (Denmark)

    Ibrom, Andreas; Dellwik, Ebba; Flyvbjerg, Henrik K.

    2007-01-01

    forest in Soro, Zealand, Denmark, amounted on average to 42% of the measured flux, while it was only 4% for the CO2 flux, which was measured with the same EC system. We recommend using the described method to correct water vapour fluxes measured in any closed-path EC system for unintended low......Turbulent water vapour fluxes measured with closed-path eddy correlation (EC) systems are unintentionally low-pass filtered by the system in a manner that varies with environmental conditions. Why and how is described here. So is the practical method that systematically corrects long-term flux...... datasets for this substantial measurement error. In contrast to earlier studies, a large number of spectra and raw data have been used in the analysis to define the low-pass filtering characteristic of the EC system. This revealed that the cut-off frequency of the closed-path EC system for water vapour...

  8. Water level measurements (bottom hydrostatic pressure) data from the Gulf of Alaska from 02 April 1983 to 25 October 1989 (NODC Accession 0000339)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Depth, pressure, and water temperature data were collected at fixed platforms in the Gulf of Mexico from April 2, 1983 to October 25, 1989. Data were submitted...

  9. Effects of bottom water dissolved oxygen variability on copper and lead fractionation in the sediments across the oxygen minimum zone, western continental margin of India

    Digital Repository Service at National Institute of Oceanography (India)

    Chakraborty, P.; Chakraborty, S.; Jayachandran, S.; Madan, R.; Sarkar, Arindam; Linsy, P.; Nath, B.N.

    in the sediments: acid soluble forms (water soluble, exchangeable and carbonate/bicarbonate forms); reducible forms (metal associates with Fe, Mn-oxyhydroxide binding phases); oxidizable forms (metal associates with sedimentary organic carbon binding phases... was included. This step also helps to remove excess salt content from the marine sediments. Thus, the modified BCR protocol allows us to separate and determine the concentrations of water soluble metal complexes (Fr. 1); ion-exchangeable, and carbonate/bicarbonate...

  10. Mobility of 2,2',5,5'-tetrachlorobiphenyl in model systems containing bottom sediments and water from the lower Fox River, Wisconsin

    Science.gov (United States)

    Elder, J.F.; James, R.V.; Steuer, J.J.

    1996-01-01

    Sediment-water partitioning and diffusive transport of 2,2',5,5'- tetrachlorobiphenyl, PCB congener IUPAC 52 (TCB52) were examined in laboratory experiments with sediments from two sites in the lower Fox River, Wisconsin. Native water was pumped at controlled flow rates through cells containing sediments amended with a known activity of carbon-14-labeled TCB52. Concentrations of TCB52 in water and sediments were determined by liquid scintillation measurements of carbon-14 activity. Sediment-water partitioning was independent of flow rate for rates up to 8 m/d. Distribution coefficients (K(d)) and soil-sorption coefficients (K(oc)) were found to be at maximum levels 5-10 cm below the surface, despite an absence of significant variation in the fraction of organic carbon (f(oc)) through the same profile. Other factors, such as the effects of colloids and microbial activity in the sediments, are likely to be important in controlling the PCB distribution. Log K(d) and log K(oc) ranges were 4.1-4.9 and 5.3-6.1, respectively, and calculated effective diffusivities at the sediment-water interface ranged from 3 to 8 x 10-10 cm2/s. Gradual increases with time in TCB52 concentrations in the water phase, possibly due to effects of microbial activity, were observed. Diffusion experiments and models showed that the TCB52 migration rate within the sediment column is 8-9 mm/yr.

  11. Core-debris quenching-heat-transfer rates under top- and bottom-reflood conditions

    International Nuclear Information System (INIS)

    Ginsberg, T.; Tutu, N.; Klages, J.; Schwarz, C.E.; Sanborn, Y.

    1983-02-01

    This paper presents recent experimental data for the quench-heat-transfer characteristics of superheated packed beds of spheres which were cooled, in separate experiments, by top- and bottom-flooding modes. Experiments were carried out with beds of 3-mm steel spheres of 330-mm height. The initial bed temperature was 810 K. The observed heat-transfer rates are strongly dependent on the mode of water injection. The results suggest that top-flood bed quench heat transfer is limited by the rate at which water can penetrate the bed under two-phase countercurrent-flow conditions. With bottom-reflood the heat-transfer rate is an order-of-magnitude greater than under top-flood conditions and appears to be limited by particle-to-fluid film boiling heat transfer

  12. Methods of analysis by the U.S. Geological Survey National Water Quality Laboratory : determination of organophosphate pesticides in bottom sediment by gas chromatography with flame photometric detection

    Science.gov (United States)

    Jha, Virendra Kumar; Wydoski, Duane S.

    2003-01-01

    A method for the isolation of 20 parent organophosphate pesticides and 5 pesticide degradates from bottom-sediment samples is described. The compound O-ethyl-O-methyl-S-proplyphosphorothioate is reported as an estimated concentration because of variable performance. In this method, the sediment samples are centrifuged to remove excess waster mixed with anhydrous sodium sulfate and Soxhlet extracted overnight with dichloromethane (93 percent) and methanol (7 percent). The extract is concentrated and then filtered through a 0.2-micrometer polytetrafluoroethylene membrane syringe filter. An aliquot of the sample extract is quantitatively injected onto two polystyrene-divinylbenzene gel-permeation chromatographic columns connected in series. The compounds are eluted with dichloromethane and a fraction is collected for analysis, with some coextracted interferences, including elemental sulfur, separated and discarded. The aliquot is concentrated and solvent exchanged to ethyl acetate. The extract is analyzed by dual capillary-column gas chromatography with flame photometric detection. Single-operator method detection limits in sodium sulfate matrix samples ranged from 0.81 to 2 micrograms per kilogram. Method performance was validated by spiking all compounds into three different solid matrices (sodium sulfate, bed sediment from Clear Creek, and bed sediment from Evergreen Lake) at three different concentrations. Eight replicates were analyzed at each concentration in each matrix. Mean recoveries of method compounds spiked in Clear Creek samples ranged from 43 to 110 percent, and those in Evergreen Lake samples ranged from 62 to 118 percent for all pesticides. Mean recoveries of method compounds spiked in reagent sodium sulfate samples ranged from 41 to 101 percent for all pesticides. The only exception was O-ethyl-O-methyl-S-propylphosphorothioate, which had an average recovery of 35 percent, and, thus, sample concentration is reported as estimated ('E' remark code).

  13. Hierarchically porous, ultra-strong reduced graphene oxide-cellulose nanocrystal sponges for exceptional adsorption of water contaminants

    DEFF Research Database (Denmark)

    Yousefi, Nariman; Wong, Kerwin K.W.; Hosseinidoust, Zeinab

    2018-01-01

    Self-assembly of graphene oxide (GO) nanosheets into porous 3D sponges is a promising approach to exploit their capacity to adsorb contaminants while facilitating the recovery of the nanosheets from treated water. Yet, forming mechanically robust sponges with suitable adsorption properties presen...

  14. Water deficit affects mesophyll limitation of leaves more strongly in sun than in shade in two contrasting Picea asperata populations.

    Science.gov (United States)

    Duan, Baoli; Li, Yan; Zhang, Xiaolu; Korpelainen, Helena; Li, Chunyang

    2009-12-01

    The aim of this study was to examine the response of internal conductance to CO(2) (g(i)) to soil water deficit and contrasting light conditions, and their consequences on photosynthetic physiology in two Picea asperata Mast. populations originating from wet and dry climate regions of China. Four-year-old trees were subjected to two light treatments (30% and 100% of full sunlight) and two watering regimes (well watered, drought) for 2 years. In both tested populations, drought significantly decreased g(i) and the net photosynthesis rate (A) and increased carbon isotope composition (delta(13)C) values in both light treatments, in particular in the sun. Moreover, drought resulted in a significantly higher relative limitation due to stomatal conductance (L(s)) in both light treatments and higher relative limitation due to internal conductance (L(i)) and abscisic acid (ABA) in the sun plants. The results also showed that L(i) (0.26-0.47) was always greater than L(s) (0.12-0.28). On the other hand, drought significantly decreased the ratio of chloroplastic to internal CO(2) concentration (C(c)/C(i)), photosynthetic nitrogen utilization efficiency (PNUE) and total biomass in the sun plants of the wet climate population, whereas there were no significant changes in these parameters in the dry climate population. Our results also showed that the dry climate population possessed higher delta(13)C values with higher ratio of internal conductance to stomatal conductance (g(i)/g(s)), suggesting that increasing the g(i)/g(s) ratio enhances water-use efficiency (WUE) in plants evolved in arid environments. Thus, we propose that the use of the g(i)/g(s) parameter to screen P. asperata plants with higher water deficit tolerance is certainly worthy of consideration. Furthermore, g(i) is an important variable, which reflects the population differences in PNUE, and it should thus be included in plant physiological investigations related to leaf economics.

  15. New Raman method for aqueous solutions: xi-function dispersion evidence for strong F(-)-water H-bonds in aqueous CsF and KF solutions.

    Science.gov (United States)

    Walrafen, George E

    2005-08-15

    The Raman xi-function dispersion method recently elucidated for the strong H-bond breaker, ClO4-, in water [G. E. Walrafen, J. Chem. Phys. 122, 094510 (2005)] is extended to the strongly H-bond forming ion, F-. Measuring the xi function is analogous to measuring DeltaG from the thermodynamic activity of the water, aH2O, as the stoichiometric mol fraction of the water in the solution decreases due to addition of an electrolyte or nonelectrolyte. xi is the derivative of the OH-stretching part of the Gibbs free energy with respect to the water mol fraction; xiomega identical with-RT[ partial differential ln(Iomega/IREF) partial differentialX2](T,P). I is the Raman intensity at omega (omega=Raman shift in cm-1); IREF, that at an arbitrary reference omega; and, X2 is the water mol fraction (X1=CsF or KF mol fraction). ln(Iomega/IREF) was found to be linear in X2 for the complete range of OH-stretching omega's, with correlation coefficients as large as 0.999 96. Linearity of ln(Iomega/IREF) versus X2 is an experimental fact for all omega's throughout the spontaneous Raman OH-stretching contour; this fact cannot be negated by relative contributions of ultrafast/fast, homogeneous/inhomogeneous processes which may underlie this linearity. Linearity in ln(Iomega/IREF) versus 1T, or in ln(Iomega/IREF) versus P, was also observed for the Raman H-bond energy DeltaE and pair volume DeltaV dispersions, respectively. A low-frequency maximum (MAX) and a high-frequency minimum (MIN) were observed in the xi function dispersion curve. Deltaxi=xiMIN-xiMAX values of -7000+/-800-cal/mol H2O for CsF, and the experimentally equal Deltaxi=-6400+/-1000-cal/mol H2O for KF, were obtained. These Deltaxi's are opposite in sign but have nearly the same absolute magnitude as the Deltaxi value for NaClO4 in water; Deltaxi=+8050+/-100-cal/mol H2O. A positive Deltaxi corresponds to a water-water H-bond breaker; a negative Deltaxi to a H-bond former; specifically, a F--water H-bond former, in the

  16. Detailed study of water quality, bottom sediment, and biota associated with irrigation drainage in the Klamath Basin, California and Oregon, 1990-92

    Science.gov (United States)

    Dileanis, Peter D.; Schwarzbach, S.E.; Bennett, Jewel

    1996-01-01

    The effect of irrigation drainage on the water quality and wildlife of the Klamath Basin in California and Oregon was evaluated during 1990-92 as part of the National Irrigation Water Quality Program of the U.S. Department of the Interior. The study focused on land serviced by the Bureau of Reclamation Klamath Project, which supplies irrigation water to agricultural land in the Klamath Basin and the Lost River Basin. The Tule Lake and Lower Klamath National Wildlife Refuges, managed by the U.S. Fish and Wildlife Service, are in the study area. These refuges provide critical resting and breeding habitat for waterfowl on the Pacific flyway and are dependent on irrigation drainwater from upstream agriculture for most of their water supply. Water-quality characteristics throughout the study area were typical of highly eutrophic systems during the summer months of 1991 and 1992. Dissolved-oxygen concentrations and pH tended to fluctuate each day in response to diurnal patterns of photosynthesis, and frequently exceeded criteria for protection of aquatic organisms. Nitrogen and phosphorus concentrations were generally at or above threshold levels characteristic of eutrophic lakes and streams. At most sites the bulk of dissolved nitrogen was organically bound. Elevated ammonia concentrations were common in the study area, especially down- stream of drain inputs. High pH of water increased the toxicity of ammonia, and concentrations exceeded criteria at sites upstream and downstream of irrigated land. Concentrations of ammonia in samples from small drains on the Tule Lake refuge leaseland were higher than those measured in the larger, integrating drains at primary monitoring sites. The mean ammonia concentration in leaseland drains [1.21 milligrams per liter (mg/L)] was significantly higher than the mean concentration in canals delivering water to the leaseland fields (0.065 mg/L) and higher than concentrations reported to be lethal to Daphnia magna (median lethal

  17. Aram Chaos: a Long Lived Subsurface Aqueous Environment with Strong Water Resources Potential for Human Missions on Mars

    Science.gov (United States)

    Sibille, L.; Mueller, R.; Niles, P. B.; Glotch, T.; Archer, P. D.; Bell, M. S.

    2015-01-01

    Aram Chaos, Mars is a crater 280 kilometers in diameter with elevations circa. minus 2 to minus 3 kilometers below datum that provides a compelling landing site for future human explorers as it features multiple scientific regions of interest (ROI) paired with a rich extensible Resource ROI that features poly-hydrated sulfates [1]. The geologic history of Aram Chaos suggests several past episodes of groundwater recharge and infilling by liquid water, ice, and other materials [1-3]. The creation of the fractured region with no known terrestrial equivalent may have been caused by melting of deep ice reservoirs that triggered the collapse of terrain followed by catastrophic water outflows over the region. Aram Chaos is of particular scientific interest because it is hypothesized that the chaotic terrain may be the source of water that contributed to the creation of nearby valleys such as Ares Vallis flowing toward Chryse Planitia. The liquid water was likely sourced as groundwater and therefore represents water derived from a protected subsurface environment making it a compelling astrobiological site [2]. The past history of water is also represented by high concentrations of hematite, Fe-oxyhydroxides, mono-hydrated and poly-hydrated sulfates [1, 2]. Poly-hydrated sulfates are likely to contain abundant water that evolves at temperatures below 500 degrees Centigrade thus conferring Aram Chaos a potentially high value for early in-situ resource utilization (ISRU) [4]. The geologic history also calls for future prospecting of deep ice deposits and possibly liquid water via deep drilling. The most recent stratigraphic units in the central part of Aram Chaos are not fractured, and are part of a dome-shaped formation that features bright, poorly-consolidated material that contains both hydrated sulfates and ferric oxides according to OMEGA (Observatoire pour la Minéralogie, l'Eau, les Glaces et l'Activité) data [5]. These surface material characteristics are

  18. Monitoring of metals in Tilapia nilotica tissues, bottom sediments ...

    African Journals Online (AJOL)

    EKEANYANWU RC

    Tilapia (Tilapia nilotica), bottom sediments and water were collected from Nworie River and Oguta Lake. The muscle, liver and gills of the fish .... drinking water by the poor, when the public water system fails. The Nworie River is ..... Lead, Cadmium and Mercury in surrounding water and organs of some species of fish from ...

  19. The GEOtop model as a tool to describe the strongly coupled energy and water balance in permafrost or seasonally-frozen soils

    Science.gov (United States)

    Endrizzi, S.

    2011-12-01

    GEOtop is a small scale grid-based model that couples the soil heat and water budgets, represents the energy exchange with the atmosphere considering the radiative and turbulent fluxes, and describes the subsurface water flow in its fully three-dimensional nature. In particular, the model reproduces the strong coupling between water and energy balance during soil freezing and thawing processes, considering the highly non-linear heat capacity effect resulting from phase change. In addition, it describes the water and energy budgets in the snow cover, represents blowing snow, and models the temporal evolution of the snow depth and, therefore, its effect on soil temperature. Infiltration in frozen soil and runoff are also represented. Vegetation effects are considered, in particular as regards snow interception, trapping, and the interactions with turbulent and radiative heat exchange. GEOtop is therefore a very useful tool in several applications that involve permafrost and seasonally-frozen soils, both in high altitude and latitude regions. In particular, GEOtop allows evaluating the effects of water lateral transport in the freezing/thawing process, effects that are often neglected, but may be significant. Applications are shown for i) a typical peat-covered arctic environment, where the position of the frost table controls the runoff production rate, due to the strong decrease of the soil hydraulic conductivity with depth; and ii) an alpine site, where borehole data are used to test the model and the effect of the upslope drainage distance is studied.

  20. Dissociation of strong acid revisited: X-ray photoelectron spectroscopy and molecular dynamics simulations of HNO3 in water

    Energy Technology Data Exchange (ETDEWEB)

    Lewis, Tanza; Winter, Berndt; Stern, Abraham C.; Baer, Marcel D.; Mundy, Christopher J.; Tobias, Douglas J.; Hemminger, J. C.

    2011-08-04

    Molecular-level insight into the dissociation of nitric acid in water is obtained from photoelectron X-ray spectroscopy and first-principles molecular dynamics (MD) simulations. Our combined studies reveal surprisingly abrupt changes in solvation configurations of undissociated nitric acid at approximately 4 M concentration. Experimentally, this is inferred from N1s binding energy shifts of HNO3(aq) as a function of concentration, and is associated with variations in the local electronic structure of the nitrogen atom. It also shows up as a discontinuity in the degree of dissociation as a function of concentration, determined here from the N1s photoelectron signal intensity, which can be separately quantified for undissociated HNO3(aq) and dissociated NO3-(aq). Intermolecular interactions within the nitric acid solution are discussed on the basis of MD simulations, which reveal that molecular HNO3 interacts remarkably weakly with solvating water molecules at low concentration; around 4 M there is a turnover to a more structured solvation shell, accompanied by an increase in hydrogen bonding between HNO3 and water. We suggest that the driving force behind the more structured solvent configuration of HNO3 is the overlap of nitric acid solvent shells that sets in around 4 M concentration. This work was supported by the US Department of Energy Basic Energy Sciences' Chemical Sciences, Geosciences & Biosciences Division. Pacific Northwest National Laboratory is operated by Battelle for the US Department of Energy.

  1. Exploring the role of wave drag in the stable stratified oceanic and atmospheric bottom boundary layer in the cnrs-toulouse (cnrm-game) large stratified water flume

    NARCIS (Netherlands)

    Kleczek, M.; Steeneveld, G.J.; Paci, A.; Calmer, R.; Belleudy, A.; Canonici, J.C.; Murguet, F.; Valette, V.

    2014-01-01

    This paper reports on a laboratory experiment in the CNRM-GAME (Toulouse) stratified water flume of a stably stratified boundary layer, in order to quantify the momentum transfer due to orographically induced gravity waves by gently undulating hills in a boundary layer flow. In a stratified fluid, a

  2. A novel self-assembly Lentinan-tetraphenylethylene​ composite with strong blue​ fluorescence in water and its properties.

    Science.gov (United States)

    Li, Mengxia; Chen, Pan; Xu, Min; Xu, Xiaojuan

    2017-10-15

    We report a unique self-assembly of lentinan, a triple helical β-(1→3)-glucan (t-LNT), in water. By molecular dynamics simulation, it was found that t-LNT aggregated preferentially along the chain direction to form long chains, accompanied by side-direction linkage to form branches. Transmission electron microscopy images demonstrated that t-LNT formed dendrite-like fibers, which further formed fishnet-like porous/mesoporous aggregates with increasing concentration. The meshes in the fishnet were ascribed to the intersection of branches. The major driving force for aggregation was expected to be hydrogen bonding between hydroxyl groups in t-LNT chains. Based on this self-assembly behavior, a novel composite was prepared from t-LNT and tetraphenylethylene (TPE) by entrapping TPE aggregates into the meshes of t-LNT fishnets. The as-prepared t-LNT/TPE composite largely enhanced the blue fluorescence of TPE in water, exhibiting stable optical property and good biocompatibility, and t-LNT is expected to show great potential as a carrier of hydrophobic molecules for biomedical application. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Solar radiation (PAR and UVA) and water temperature in relation to biochemical performance of Gelidium corneum (Gelidiales, Rhodophyta) in subtidal bottoms off the Basque coast

    Science.gov (United States)

    Quintano, Endika; Ganzedo, Unai; Díez, Isabel; Figueroa, Félix L.; Gorostiaga, José M.

    2013-10-01

    Gelidium corneum (Hudson) J.V. Lamouroux is a very important primary producer in the Cantabrian coastal ecosystem. Some local declines in their populations have been recently detected in the Basque coast. Occurrences of yellowing and an unusual branch breakdown pattern have also been reported for some G. corneum populations. In order to gain further insight into those environmental stressors operating at a local scale, here we investigate if shallow subtidal populations of G. corneum living under potentially different conditions of irradiance (PAR and UVA) and water temperature exhibit differences in some biochemical indicators of stress, namely C:N, antioxidant activity (radical cation of 2,2‧-azino-bis (3-ethylbenzothiazoline-6-sulfonate); ABTS+ assay) and mycosporine-like amino acids (MAAs) (Asterine 330 and Palythine). We hypothesised that G. corneum subjected to higher ambient levels of irradiance and water temperature would show higher C:N ratios, lower antioxidant activity and higher MAA concentrations. Our results partially support this hypothesis. We found that G. corneum exposed to increased levels of irradiance (PAR, UVA) exhibited greater C:N ratios and lower antioxidant activity (higher IC50), whereas no relationship was found regarding MAAs. No differences in biochemical performance in relation to temperature were detected among G. corneum exposed to comparable high light. Similarly, G. corneum growing under lower UVA radiation levels showed no differences in any of the measured biochemical variables with regard to PAR and water temperature. These findings suggest that, among the environmental factors examined, UVA radiation may be an important driver in regulating the along-shore variation in G. corneum biochemical performance. Therefore, the role of irradiance, especially UV radiation, in potential future alterations in Cantabrian G. corneum populations cannot be ruled out as a potential underlying factor.

  4. Competition between Free-Floating Plants Is Strongly Driven by Previously Experienced Phosphorus Concentrations in the Water Column.

    Directory of Open Access Journals (Sweden)

    Edwin T H M Peeters

    Full Text Available Nutrients can determine the outcome of the competition between different floating plant species. The response of floating plants to current phosphorus levels may be affected by previously experienced phosphorus concentrations because some species have the ability to store excess phosphorus for later use. This might have an impact on their competition. Here, we investigate the effect of previous and actual phosphorus concentrations on the growth rate of free-floating plant species (Azolla filiculoides, Lemna minor/gibba and Ricciocarpus natansand the effect of phosphorus history on the competition between L. minor/gibba and A. filiculoides and between L. minor/gibba and R. natans. As expected, plant growth was lower when previously kept at low instead of high phosphorus concentrations. Growth of L. minor/gibba and A. filiculoides with a phosphorus rich history was comparable for low and high actual phosphorus concentrations, however, internal phosphorus concentrations were significantly lower with low actual phosphorus concentration. This indicates that both species perform luxury phosphorus uptake. Furthermore, internal P concentration in Azolla and Lemna increased within two weeks after a period of P deficit without a strong increase in growth. A. filiculoides in a mixture with L. minor/gibba grew faster than its monoculture. Morphological differences may explain why A. filiculoides outcompeted L. minor/gibba and these differences may be induced by phosphorus concentrations in the past. Growth of L. minor/gibba was only reduced by the presence of A. filiculoides with a high phosphorus history. Growth of L. minor/gibba and R. natans in mixtures was positively affected only when they had a high phosphorus history themselves and their competitor a low phosphorus history. These observations clearly indicate that phosphorus history of competing plants is important for understanding the outcome of the competition. Therefore, actual and previously

  5. Two tropical conifers show strong growth and water-use efficiency responses to altered CO2 concentration.

    Science.gov (United States)

    Dalling, James W; Cernusak, Lucas A; Winter, Klaus; Aranda, Jorge; Garcia, Milton; Virgo, Aurelio; Cheesman, Alexander W; Baresch, Andres; Jaramillo, Carlos; Turner, Benjamin L

    2016-11-01

    Conifers dominated wet lowland tropical forests 100 million years ago (MYA). With a few exceptions in the Podocarpaceae and Araucariaceae, conifers are now absent from this biome. This shift to angiosperm dominance also coincided with a large decline in atmospheric CO 2 concentration (c a ). We compared growth and physiological performance of two lowland tropical angiosperms and conifers at c a levels representing pre-industrial (280 ppm), ambient (400 ppm) and Eocene (800 ppm) conditions to explore how differences in c a affect the growth and water-use efficiency (WUE) of seedlings from these groups. Two conifers (Araucaria heterophylla and Podocarpus guatemalensis) and two angiosperm trees (Tabebuia rosea and Chrysophyllum cainito) were grown in climate-controlled glasshouses in Panama. Growth, photosynthetic rates, nutrient uptake, and nutrient use and water-use efficiencies were measured. Podocarpus seedlings showed a stronger (66 %) increase in relative growth rate with increasing c a relative to Araucaria (19 %) and the angiosperms (no growth enhancement). The response of Podocarpus is consistent with expectations for species with conservative growth traits and low mesophyll diffusion conductance. While previous work has shown limited stomatal response of conifers to c a , we found that the two conifers had significantly greater increases in leaf and whole-plant WUE than the angiosperms, reflecting increased photosynthetic rate and reduced stomatal conductance. Foliar nitrogen isotope ratios (δ 15 N) and soil nitrate concentrations indicated a preference in Podocarpus for ammonium over nitrate, which may impact nitrogen uptake relative to nitrate assimilators under high c a SIGNIFICANCE: Podocarps colonized tropical forests after angiosperms achieved dominance and are now restricted to infertile soils. Although limited to a single species, our data suggest that higher c a may have been favourable for podocarp colonization of tropical South America 60

  6. Effect of leachate solutions from fly ash bottom ash on groundwater quality

    Energy Technology Data Exchange (ETDEWEB)

    Kopsick, D.A.; Angino, E.E.

    1981-12-01

    Leaching experiments on fly ash and bottom ash for Ca, Mg, Na, K, Fe, Mn, Zn, Cu and Pb indicated a potential for contamination of ground- and surface-water supplies. Due to the variability in chemical composition of coals, it is difficult to make generalizations concerning the chemistry of leachate solutions from the ashes of the coals. A decrease in concentration with time of leaching was observed for all elements, except for Ca which was released at a constant rate. Fly ash from a Missouri coal generated a leachate enriched in Pb, Zn, Cu, Fe, Mn and Cd, reflective of the high Pb-Zn mineralization present in the surrounding area. With a pH of 3.0 this ash has the greatest potential for groundwater contamination. Conversely, leachates from Wyoming fly and bottom ashes exhibited low trace-metal concentrations. These same solutions were high in K, Na, Ca and Mg, and also showed strong pozzolanic behaviour, which will reduce the leachability of these ashes. In most instances, fly and bottom ash from Kentucky and Illinois coals yielded leachates intermediate in elemental composition to leachates of Missouri and Wyoming coal ashes. Leaching experiments indicate that it is not valid to predict the chemistry of leachates from fly and bottom ash based solely on the chemical composition of the ash. (16 refs.)

  7. Internal Wave Exposure in Eastern Tropical Pacific Panamá and Costa Rica is Coincident with Strong Vertical Gradients in Shallow Water Benthic Community Composition

    Science.gov (United States)

    Leichter, J.

    2016-02-01

    Multi-year time series and hydrographic observations at near shore sites in Eastern Tropical Pacific Panamá and Costa Rica show regionally coherent internal wave exposure that is strongly modulated across seasons. Sites were sampled to the west of the Osa Peninsula in Costa Rica and near Isla Coiba in Panamá with spatial separation of approximately 250 km. From approximately January through April each year, internal wave activity inferred from high frequency temperature variability is pronounced, associated with well developed and shallow density stratification. The occurrence of highly variable temperatures is correlated with shallow density stratification and oxygen concentrations as low as 1 to 1.5 µg L-1 measured at the base of the thermocline at 50 to 60 m depth in the offshore water column during winter and spring conditions. The physical variability in the near shore corresponds to and appears to drive strong vertical gradients in the benthic community assemblages on rocky substrata. With increasing depth the benthic communities are dominated by scleractinian corals (predominantly in the genera Pocillopora, Pavona, and Porites) from near the surface to approximately 8 m depth, followed by of a range of sessile suspension feeders including sea fans and gorgonians at approximately 10 to 20 m depth, and predominantly rocky bare space with sporadic algal and isolated invertebrate communities to 30 m depth which was the limit of the current sampling. This vertical patterning of the benthic community appears to reflect the strong vertical gradients in hydrographic forcing. From May through December hydrographic conditions at the benthic study sites is significantly less variable, associated with deeper offshore stratification and a decrease in temperature variation driven by internal wave activity impinging on the shallow water ecosystems. The highly variable physical environment in these tropical settings sets a context for strong patterning of benthic

  8. High-technology metals as emerging contaminants: Strong increase of anthropogenic gadolinium levels in tap water of Berlin, Germany, from 2009 to 2012

    International Nuclear Information System (INIS)

    Tepe, N.; Romero, M.; Bau, M.

    2014-01-01

    Highlights: • Monitoring study Berlin-2012 confirms tap water contamination with gadolinium. • Contamination confined to western districts of Berlin. • Strong increase of anthropogenic gadolinium from 2009 to 2012. • Anthropogenic gadolinium is tracer for wastewater-derived substances. - Abstract: The distribution of rare earth elements (REE) in tap water sampled in December 2012 in Berlin, Germany, is characterized by anomalously high levels of gadolinium (Gd). While the western districts of the city show strong anthropogenic positive Gd anomalies in REE distribution patterns, the eastern districts are (almost) unaffected. This contamination with anthropogenic Gd results from Gd-based contrast agents used in Magnetic Resonance Imaging, that enter rivers, groundwater and eventually tap water via the clear water effluent from wastewater treatment plants. While the spatial distribution of anthropogenic Gd in 2012 confirms results of an earlier study in 2009 (Kulaksiz and Bau, 2011a), anthropogenic Gd concentrations have increased between 1.5- and 11.5-fold in just three years. This confirms predictions based upon the increase of anthropogenic Gd concentrations in the Havel River over the past two decades and the time it takes the water to migrate from the Havel River to the groundwater production wells. Anomalously high levels of anthropogenic Gd in tap water, which are not confined to Berlin but have also been observed in London, U.K., and in German cities in the Ruhr area and along the Rhine River, reveal that high-technology metals have become emerging contaminants. While non-toxic at the observed concentrations, the anthropogenic Gd is a microcontaminant that may be used as a conservative pseudo-natural tracer for wastewater-derived xenobiotics such as pharmaceuticals, food additives and personal care products. Our results suggest that monitoring the concentrations of such substances in Berlin’s drinking water can be restricted to a few central and

  9. CHARACTERISTICS OF SLUDGE BOTTOM MESH

    Directory of Open Access Journals (Sweden)

    Kamil Szydłowski

    2016-05-01

    Full Text Available The main aim of the study was to assess the selected heavy metals pollution of bottom sediments of small water bodies of different catchment management. Two ponds located in Mostkowo village were chosen for investigation. The first small water reservoir is surrounded by the cereal fields, cultivated without the use of organic and mineral fertilizers (NPK. The second reservoir is located in a park near rural buildings. Sediment samples were collected by the usage of KC Denmark sediments core probe. Samples were taken from 4 layers of sediment, from depth: 0–5, 5–10, 10–20 and 20–30 cm. Sampling was made once during the winter period (2014 year when ice occurred on the surface of small water bodies, from three points. The material was prepared for further analysis according to procedures used in soil science. The content of heavy metals (Cd, Cr, Cu, Ni, Pb and Zn were determined by atomic absorption spectrometry by usage of ASA ICE 3000 Thermo Scientific after prior digestion in the mixture (5: 1 of concentrated acids (HNO3 and HClO4. Higher pH values ​​were characteristic for sediments of pond located in a park than in pond located within the agricultural fields. In both small water bodies the highest heavy metal concentrations occurred in the deepest points of the research. In the sediments of the pond located within crop fields the highest concentration of cadmium, copper, lead and zinc were observed in a layer of 0–5 cm, wherein the nickel and chromium in a layer of 20–30 cm. In the sediments of the pond, located in the park the highest values ​​occurred at the deepest sampling point in the layer taken form 10–20 cm. Sediments from second reservoir were characterized by the largest average concentrations of heavy metals, except the lead content in sediment form the layer of 10–20 cm. According to the geochemical evaluation of sediments proposed by Bojakowska and Sokołowska [1998], the majority of samples belongs to Ist

  10. Fresh Bottom Ash Characteristics Dependence on Fractional Composition

    Directory of Open Access Journals (Sweden)

    Jurgita Seniūnaitė

    2017-09-01

    Full Text Available Waste incineration process generates two main by-products streams: fly ash and bottom ash. Bottom ash is composed of a variety of oxides, heavy metals and salts. Chemical materials distributed unevenly in different fractions of bottom ash. This study investigates the heavy metals (Pb, Cd content dependence of bottom ash and fraction composition. Studies were performed with five different fractions (0–2 mm; 2–5.6 mm; 5.6–11.2 mm; 11.2–22,4 mm; 22.4–40 mm of fresh bottom ash. After a one-step leaching test (distilled water was used as a solvent, was determinate, that highest concentrations of the lead (Pb (from 0.141 to 0.146 mg/l are leached from the smallest (0–2 mm 2–5.6 mm bottom ash fractions particles. Heavy metals concentration in these fractions eluates respectively was 2.83 and 2.91 times higher than the limit value of leaching. The highest concentration of cadmium (4.214 mg/l was determinate in 0–2 mm fraction bottom ash eluate. concentration of cadmium was 1.40 times higher than the limit value of leaching. It can be concluded that 0–2 mm; 2–5.6 mm fraction bottom ash can’t be used in civil engineering, without pre-treatment (eg. washing or aging.

  11. In-situ methylation of strongly polar organic acids in natural waters supported by ion-pairing agents for headspace GC-MSD analysis

    Energy Technology Data Exchange (ETDEWEB)

    Neitzel, P.L.; Walther, W. [Dresden University of Technology, Institute for Groundwater Managemant, Dresden (Germany); Nestler, W. [Institute for Technology and Economics, Department of Civil Engineering and Architecture, Dresden (Germany)

    1998-06-01

    Strongly polar organic substances like halogenated acetic acids have been analyzed in surface water and groundwater in the catchment area of the upper Elbe river in Saxony since 1992. Coming directly from anthropogenic sources like industry, agriculture and indirectly by rainfall, their concentrations can increase up to 100 {mu}g/L in the aquatic environment of this catchment area. A new static headspace GC-MSD method without a manual pre-concentration step is presented to analyze the chlorinated acetic acids relevant to the Elbe river as their volatile methyl esters. Using an ion-pairing agent as modifier for the in-situ methylation of the analytes by dimethylsulfate, a minimal detection limit of 1 {mu}g/L can be achieved. Problems like the thermal degradation of chlorinated acetic acids to halogenated hydrocarbons and changing reaction yields during the headspace methylation, could be effectively reduced. The method has been successfully applied to monitoring bank infiltrate, surface water, groundwater and water works pumped raw water according to health provision principles. (orig.) With 3 figs., 2 tabs., 29 refs.

  12. Feasibility of wavelength dispersive X-ray fluorescence spectrometry for a simplified analysis of bromine in water samples with the aid of a strong anion exchange disk

    International Nuclear Information System (INIS)

    An, Jinsung; Jung, Hyeyeon; Bae, Jo-Ri; Yoon, Hye-On; Seo, Jungju

    2014-01-01

    The feasibility of wavelength dispersive X-ray fluorescence spectrometry (WDXRF) for a simplified analysis of bromine (Br) in water samples with the aid of strong anion exchange (SAX) disk was assessed in this study. Dissolved Br in the water sample was pre-concentrated on the SAX disk and directly analyzed by WDXRF without an elution step. The SAX disk was capable of fully adsorbing both bromide (Br − ) and bromate (BrO 3 − ) on its surface owing to their anionic properties, regardless of the pH level of environmental samples. The SAX–WDXRF system was examined using calibration standards (i.e., SAX disks with specific amounts of Br retained; 1, 10, 50, 100 and 500 μg), and a determination coefficient of R 2 = 0.9999 was yielded. The system had a low detection limit for Br (limit of detection = 0.253 μg for Br on the SAX disk) with good reproducibility (relative standard error (RSE) = 4–7%). Spike and inter-comparison tests were performed to confirm the accuracy of the proposed SAX–WDXRF method. Both tests exhibited reasonable accuracy (RSE = 3–6%). The method is simple and easy, indicating a great possibility of application in various environmental sample types, especially for which a simplified analytical system for the determination of Br is urgently required. - Highlights: • Bromide and bromate were entirely retained on a strong anion exchange (SAX) disk. • The SAX disk was used to pre-concentrate dissolved Br species from water samples. • The SAX disk adsorbing dissolved Br was directly analyzed by WDXRF. • The accuracy of the SAX–WDXRF method was confirmed by spike and inter-comparison tests. • Rapid and sensitive Br analysis can be achieved using the proposed SAX–WDXRF method

  13. Mechanism of water pollution in a shallow lake. Part 4. Behavior of phosphorus and its compounds in bottom sediment in Nanbu Tega-numa. Sensuisei konuma no suishitsu odaku kiko. 4. Nanbu Teganuma no teishitsuchu no zenrin oyobi rin kagobutsu no kyodo

    Energy Technology Data Exchange (ETDEWEB)

    Tatsumoto, H.; Tomizawa, T.; Makino, S. (Chiba University, Chiba (Japan). Faculty of Engineering); Yoshihara, C.; Aikawa, M. (Kisarazu College of Technology, Chiba (Japan))

    1994-03-15

    Identification of the state of eutrophication in lakes requires importantly learning behavior of phosphorus contained in bottom mud. The Lake Nanbu Tega-numa was chosen for its water shallowness and it having only one each of water inlet and outlet, where a cylindrical sampler was used to sample bottom mud from two or more points of the lake to investigate the forms and distribution of phosphorus. As a result, the following matters were made clear: the vertical phosphorus distribution showed the highest phosphorus content in a layer of a depth of 30 cm from the lake surface, and the content tended to decrease at a depth of 45 cm; the horizontal distribution had a highest value of 5.1 mg/g (dry) at the water inlet area, which declined as moving toward the center of the lake; the water area at a largest lake width showed the minimum value of 1.3 mg/g; and the water inlet area had the highest inorganic state phosphorus at the bottom mud surface as 2.9 mg/g for Fe-type phosphorus and 0.34 mg/g for Ca-type phosphorus, which showed a trend of decreasing as the lake water moves down. 5 refs., 3 figs., 2 tabs.

  14. Water Chemistry and Conductivity-Temperature-Depth (CTD) profiles at coral reef sites in Batangas, Philippines from discrete surface and bottom water samples collected between 2012-03-12 and 2015-06-03 (NCEI Accession 0162832)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Laboratory experiments reveal calcification rates of crustose coralline algae (CCA) are strongly correlated to seawater aragonite saturation state. Predictions of...

  15. Effect of leachate solutions from fly and bottom ash on groundwater quality

    Science.gov (United States)

    Kopsick, Deborah A.; Angino, Ernest E.

    1981-12-01

    Leaching experiments on fly and bottom ash for Ca, Mg, Na, K, Fe, Mn, Zn, Cu and Pb indicated a potential for contamination of ground- and surface-water supplies. Due to the variability in chemical composition of coals, it is difficult to make generalizations concerning the chemistry of leachate solutions from the ashes of the coals. A decrease in concentration with time of leaching was observed for all elements, except for Ca which was released at a constant rate. Fly ash from a Missouri coal generated a leachate enriched in Pb, Zn, Cu, Fe, Mn and Cd, reflective of the high Pb/1bZn mineralization present in the surrounding area. With a pH of 3.0 this ash has the greatest potential for groundwater contamination. Conversely, leachates from Wyoming fly and bottom ashes exhibited low trace-metal concentrations. These same solutions were high in K, Na, Ca and Mg, and also showed strong pozzolanic behvior, which will reduce the leachability of these ashes. In most instances, fly and bottom ash from Kentucky and Illinois coals yielded leachates intermediate in elemental composition to leachates of Missouri and Wyoming coal ashes. Leaching experiments indicate that it is not valid to predict the chemistry of leachates from fly and bottom ash based solely on the chemical composition of the ash. From the limited number of parameters and sites examined in this study, it is clear that many of the problems related to leachates from fly and bottom ash and gob piles are site specific as well as specific to the source of coal burned. These results are, nevertheless, indicative of problems likely to be encountered in working with these materials.

  16. High resolution bottom penetrating sonar. Test report

    Energy Technology Data Exchange (ETDEWEB)

    Volberg, H.

    1996-08-01

    The Great Belt Sonar (GBS) is a multi-functional sub-bottom profiling and buried object detection sonar system that can provide a wide variety of selectable operations based on user needs and environmental characteristics. In order to assess the bottom penetration and pipe tracking performance of the sonar system, controlled laboratory tests with known environmental parameters are required. Once the general characteristic and the potential for pipe detection of the system under the laboratory environment are established, field tests can be carried out to fully exercise all the system operations under the real ocean environment. Theoretical small scale system test considerations and a system setup for proof-of-concept trials have been proposed in `Pipe Tracking Sonar`, technical report. This report describes recent testing of the GBS system under small scale controlled laboratory environment. The experiment objectives given the size limitations of the laboratory environment, and the test equipment configuration and setup are described. The GBS system test measurements and findings are given. Finally, conclusions and future design and test considerations are discussed. The report assumes familiarity with the GBS system specifications and operational characteristics as well as theoretical background on acoustic propagation through the water-bottom interface. (EG)

  17. Pressing technology for large bottoms

    International Nuclear Information System (INIS)

    Jilek, L.

    1986-01-01

    The technology has been selected of a circular plate bent into the shape of a trough, for pressing bottoms of pressure vessels from a circular plate of large diameter. The initial sheet is first bent in the middle by heating with the edges remaining straight. These are then welded longitudinally by electroslag welding and the circular shape is flame cut. The result will be a plate with a straight surface in the middle with raised edges which may be pressed into the desired shape. In this manner it is also possible to press pressure vessel bottoms with tube couplings from plates which are thickened in the middle and drilled; additional welding is then eliminated. Deformation from heat treatment may be avoided by the use of a fixture in the shape of a ring with a groove into which is fixed the edge of the bottom. During hardening of the bottom it will be necessary to care for the withdrawal of vapours and gases which would hamper uniform cooling. Bottom hardening with the grill and the cupola downwards has been proven. Deformation which occurs during treatment may to a certain extent be removed by calibration which cannot, however, be made without special fixtures and instruments. (J.B.)

  18. Use of strong anion exchange resins for the removal of perfluoroalkylated substances from contaminated drinking water in batch and continuous pilot plants.

    Science.gov (United States)

    Zaggia, Alessandro; Conte, Lino; Falletti, Luigi; Fant, Massimo; Chiorboli, Andrea

    2016-03-15

    In recent years abnormally high levels of perfluoroalkylated substances (PFAS) have been detected both in surface and underground water sampled in an area covering approximately 150 square kilometers in the Veneto region (Italy) indicating the presence of a pollution point source (fluorochemicals production plant). Adsorption on granular activated carbon is an emergency measure which is poorly effective requiring frequent replacement. This work focuses on the application of three strong anion exchange resins (Purolite® A520E, A600E and A532E) for the removal of traces of PFOA, PFOS, PFBA and PFBS (concentration of hundreds of ng L(-1)) from drinking water. This technology is attractive for the possibility of reusing resins after an in-situ regeneration step. A strong relationship between the hydrophobicity of the exchange functional group of the resin and its capacity in removing PFAS exists. A600E (non hydrophobic) and A520E (fairly hydrophobic) show a reduced sorption capacity compared to A532E (highly hydrophobic). While A600E and A520E can be regenerated with solvent-less dilute solutions of non-toxic NH4Cl and NH4OH, A532E requires concentrated solutions of methanol or ethanol and 1% NH4Cl and for the sake of this work it was regarded as non-regenerable. The volume of regeneration effluents requiring incineration can be efficiently reduced by more than 96.5% by using reverse osmosis coupled with under-vacuum evaporation. Transmission electron analysis on saturated resins showed that large molecular macro-aggregates of PFAS can form in the intraparticle pores of resin indicating that ion exchange is not the only mechanism involved in PFAS removal. Copyright © 2015 Elsevier Ltd. All rights reserved.

  19. Quantification of groundwater-stream water interactions based on temperature depth profiles under strong upwelling conditions in a sand-bed stream

    Science.gov (United States)

    Gaona, Jaime; Lewandowski, Jörg

    2017-04-01

    The quantification of groundwater-surface water interactions is not only required for budgets but also for an understanding of the complex relations between hyporheic exchange flows (HEF) and the associated chemical and biological processes that take place in hyporheic zones (HZ). Thus, there is a strong need to improve methods for flux estimation.The present study aims to quantify the vertical fluxes across the riverbed from data of temperature depth profiles recorded at the River Schlaube in East Brandenburg, Germany. In order to test the capabilities and limitations of existing methods, fluxes were calculated with an analytical (VFLUX, based on the amplitude attenuation and phase shift analysis) and a numerical (1DTempPro, parametrization based on observed values) approach for heat conduction. We conclude that the strong limitations of the flux estimates are caused by thermal and hydraulic heterogeneities of the sediment properties. Consequently, upscaling of fluxes must include other thermal techniques able to portray the spatial variability of thermal patterns, along with further developments of methods to link thermal depth profiles, thermal patterns of the surface of the streambed and all the other factors involved. Considering time and costs of temperature depth profiles of riverbeds, and the need for multiple devices to cover larger areas, it is additionally tested whether vertical fluxes can be infered from the uppermost temperature sensors of a data set. That would ease hyporheic investigations at larger scales.

  20. Bottom nozzle of a LWR fuel assembly

    International Nuclear Information System (INIS)

    Leroux, J.C.

    1991-01-01

    The bottom nozzle consists of a transverse element in form of box having a bending resistant grid structure which has an outer peripheral frame of cross-section corresponding to that of the fuel assembly and which has walls defining large cells. The transverse element has a retainer plate with a regular array of openings. The retainer plate is fixed above and parallel to the grid structure with a spacing in order to form, between the grid structure and the retainer plate a free space for tranquil flow of cooling water and for debris collection [fr

  1. Revisiting the round bottom flask rainbow experiment

    Science.gov (United States)

    Selmke, Markus; Selmke, Sarah

    2018-01-01

    A popular demonstration experiment in optics uses a round-bottom flask filled with water to project a circular rainbow on a screen with a hole through which the flask is illuminated. We show how the vessel's wall shifts the first- and second-order bows towards each other and consequently reduces the width of Alexander's dark band. We address the challenge this introduces in observing Alexander's dark band, and explain the importance of a sufficient distance between the flask and the screen. The wall-effect also introduces a splitting of the bows that can easily be misinterpreted.

  2. Unique 'man-made' object: reservoirs B10 and B11 of Techa cascade and means for in-situ measurement of its contamination - Water, soil, bottom sediments

    Energy Technology Data Exchange (ETDEWEB)

    Ivanov, Oleg; Potapov, Victor; Stepanov, Vyacheslav; Smirnov, Sergey; Volkovich, Anatoly [National Research Centre - Kurchatov Institute, 1 Kurchatov Sq., Moscow (Russian Federation)

    2014-07-01

    Contamination of natural objects - alarm fallout zones and flood plains near production sites (the result of technological accidents and resource extraction) occupy large areas. Large area and volume of pollution, moderate activity facilities (at low and medium-level rad-wastes) to make such objects specific types of radioactive waste. These objects exist for a long time, now they are characterized by a bound state of nuclides with the matrix. There are no cost-effective ways to remove these rad-wastes, the only solution for the rehabilitation of such areas is their isolation and regular monitoring through direct and indirect measurements. The task of mapping and subsequent monitoring of pollution is very complex. Most of the complexity of the laboratory measurement techniques, as well as high levels of contamination (to 10{sup 9} Bk/m{sup 2}) for radionuclides Cs-137 and Sr-90 require for mapping pollution field physical methods of measurement of the specific activity of radionuclides directly on the ground. The set of instruments for in-situ contamination measurements: a portable spectrometric collimated detector, collimated borehole spectrometric detector, underwater spectrometric detector, spectrometer for field measurements of the specific activity of Sr-90, connected to a portable MCA. The complex was used in Bryansk region, on the Techa river and Yenisei river. We present measurements of contamination in and around the reservoir No. 10 of Techa cascade containing a huge amount of radioactive waste. Measurements are performed in the framework of international expeditions in 2008, 2011 and 2012. To develop plans and programs for the rehabilitation of non-standard large-size objects containing radioactive waste precise and detailed measurement data are necessary and very often there is not enough of such data. Measurements of contaminated water, soil and bottom sediments in area of water reservoirs of Techa cascade have shown that unique system of detectors and

  3. Characterization of bottom sediments in the Río de la Plata estuary

    Science.gov (United States)

    Simionato, Claudia G.; Moreira, Diego

    2016-04-01

    Bottom sediments and surface water samples were collected in the intermediate and outer Río de la Plata Estuary during 2009-2010, in six repeated cruises, with 26 stations each. Samples were processed for grain size using a laser particle size analyzer, and water and organic matter contents. The aim of this work is to analyze this data set to provide a comprehensive and objective characterization of the bottom sediments distribution, to study their composition and to progress in the construction of a conceptual model of the involved physical mechanisms. Principal Components Analysis is applied to the bottom sediments size histograms to investigate the spatial patterns. Variations in grain-size parameters contain information on possible sediment transport patterns, which were analyzed by means of trend vectors. Sediments show a gradational arrangement of textures, sand dominant at the head, silt in the intermediate estuary and clayey silt and clay at its mouth; textures become progressively more poorly sorted offshore, and the water and organic matter contents increase. And seem to be strongly related to the geometry and the hydrodynamics. Along the Northern coast of the intermediate estuary, well sorted medium and fine silt predominates, whereas in the Southern coast, coarser and less sorted silt prevails, due to differences in tidal currents and/or in water pathways. Around Barra del Indio, clay prevails over silt and sand, and the water and organic matter contents reach a maximum, probably due flocculation, and the reduction of the currents. Immediately seawards the salt wedge, net transport reverses its direction and well sorted coarser sand from the adjacent shelf dominates. Relict sediment is observed around the Santa Lucía River, consisting of poorly sorted fine silt and clay. The inferred net transport suggests convergence at the Barra del Indio shoal, which is consistent with the constant growing of the banks.

  4. Vitrification of bottom ash from a municipal solid waste incinerator.

    Science.gov (United States)

    Xiao, Y; Oorsprong, M; Yang, Y; Voncken, J H L

    2008-01-01

    During incineration of municipal solid waste (MSW), various environmentally harmful elements and heavy metals are liberated either into bottom ash, or carried away with the off-gases and subsequently trapped in fly-ash. If these minor but harmful elements are not properly isolated and immobilized, it can lead to secondary environmental pollution to the air, soil and water. The stricter environmental regulations to be implemented in the near future in The Netherlands require a higher immobilization efficiency of the bottom ash treatment. In the present study, MSW incinerator bottom ash was vitrified at higher temperatures and the slag formed and metal recovered were examined. The behaviour of soluble elements that remain in the slag is evaluated by standard leaching test. The results obtained can provide a valuable route to treat the ashes from incinerators, and to make recycling and more efficient utilization of the bottom ash possible.

  5. Bottom reflector for power reactors

    International Nuclear Information System (INIS)

    Elter, C.; Kissel, K.F.; Schoening, J.; Schwiers, H.G.

    1982-01-01

    In pebble bed reactors erosion and damage due fuel elements movement on the surface of the bottom reflector should be minimized. This can be achieved by chamfering and/or rounding the cover edges of the graphite blocks and the edges between the drilled holes and the surface of the graphite block. (orig.) [de

  6. Culture from the Bottom Up

    Science.gov (United States)

    Atkinson, Dwight; Sohn, Jija

    2013-01-01

    The culture concept has been severely criticized for its top-down nature in TESOL, leading arguably to its falling out of favor in the field. But what of the fact that people do "live culturally" (Ingold, 1994)? This article describes a case study of culture from the bottom up--culture as understood and enacted by its individual users.…

  7. Grounding experiments on soft bottoms

    DEFF Research Database (Denmark)

    Sterndorff, M.J.; Pedersen, Preben Terndrup

    1996-01-01

    To verify a theoretical analysis procedure for calculation of the hull girder response of ships running aground, a series of large-scale ship grounding experiments was performed on an artificial island made of engineered fill. The tests were conducted by running a condemned fishing vessel up...... for grounding on soft bottoms....

  8. Removal of Thin Cirrus Path Radiances in the 0.4-1.0 micron Spectral Region Using the 1.375-micron Strong Water Vapor Absorption Channel

    Science.gov (United States)

    Gao, Bo-Cai; Kaufman, Yoram J.; Han, Wei; Wiscombe, Warren J.

    1998-01-01

    Through analysis of spectral imaging data acquired with the Airborne Visible Infrared Imaging Spectrometer (AVIRIS) from an ER-2 aircraft at 20 km altitude during several field programs, it was found that narrow channels near the center of the strong 1.38-micron water vapor band are very sensitive in detecting thin cirrus clouds. Based on this observation from AVIRIS data, a channel centered at 1.375 microns with a width of 30 nm was selected for the Moderate Resolution Imaging Spectrometer (MODIS) for remote sensing of cirrus clouds from space. The sensitivity of the 1.375-micron MODIS channel to detect thin cirrus clouds during the day time is expected to be one to two orders of magnitude better than the current infrared emission techniques. As a result, a larger fraction of the satellite data will likely be identified as containing cirrus clouds. In order to make better studies of surface reflectance properties, thin cirrus effects must be removed from satellite images. We have developed an empirical approach for removing/correcting thin cirrus effects in the 0.4 - 1.0 micron region using channels near 1.375 microns. This algorithm will be incorporated into the present MODIS atmospheric correction algorithms for ocean color and land applications and will yield improved MODIS atmospheric aerosol, land surface, and ocean color products.

  9. Influence of the sea bottom relief on the Cystoseira communities of the North Caucasian coast of the Black Sea

    Science.gov (United States)

    Simakova, U. V.

    2009-10-01

    We studied the characteristics of the Cystoseira ( Cystoseira barbata C. Ag, Cystoseira crinita (Desf.) Bory) community at the North Caucasian coast of the Black Sea under the conditions of the pronounced sea-bottom relief, namely, ridge- and steplike benches. It is shown that a number of parameters of the composition and community structure (the species richness, the diversity indices, the biomass, the dominance pattern, and the epiphyte: basephyte ratio) are influenced more strongly by the sea bottom relief than by the depth. Presumably, this may be due to the variation of the integrated water velocity over different relief elements. The major dominants are shown to have different ecologies: C. barbata inhabits hollows, where the wave effect is minor, while C. crinita prefers to inhabit the ridge tops, i.e., the biotopes with increased hydrodynamic activity.

  10. Compositions of foraminifera-rich turbidite sediments from the Shenhu area on the northern slope of the South China Sea: Implication for the presence of deep water bottom currents

    Science.gov (United States)

    Li, Niu; Feng, Dong; Chen, Linying; Wang, Hongbin; Chen, Duofu

    2017-05-01

    The sediments in gravity core DH-1, collected from Shenhu area on the northern slope of the South China Sea, are composed of two dark grey clay silt layers (A1 and A3) and two foraminifera-rich layers (A2 and A4) (A1 is the top layer and A4 is the bottom layer). Major and trace metal contents, along with grain size and mineralogic data suggest that these silt layers represent background hemipelagic sedimentation. Unlike silt layers, the intervening foraminifera-rich layerA4 exhibits a fining-upward trend, is distal turbidite. Grain size CM diagram and the sharp contacts between the foraminifera-rich layer A2 and the upper and lower layers suggest layer A2 is the result of depositional interaction between turbidite and bottom currents. AMS 14C dating of planktonic foraminifera indicate the age of the turbidite in A2 is between15.3 ka and 22.6 ka. We hypothesize that turbidite formation in this period was related to the increase supply of terrigenous matter since the Last Glacial Maximum. The rapid deposition of each turbidite led to reduced rates of oxygen diffusion into the sediment, allowing anoxic conditions develop in sediments and fostering U enrichment (>3.1 μg/g) in foraminifera-rich layer A4b. In contrast, decrease concentration of U and U/Mo ratios in foraminifera-rich layerA2, which is possibly due to U remobilization as a consequence of downward penetration of the oxidation front from the oxygen rich bottom currents. These new data suggest that authigenic U was quite sensitive to the inflow of bottom currents, and U/Mo ratios may indicate the depositional environmental change in relation to the bottom current action on the turbidite.

  11. Weaver Bottoms Wildlife Habitat Restoration: A Case Study

    Science.gov (United States)

    1994-05-01

    years. The proportion of sport fish, rough fish, and forage fish captured, showed little change between pre- and post-construction periods. Esport fish...vegetation that is not able to regenerate by seed and the subsequent development of open water, like what happened in Weaver Bottoms. If all stresses

  12. Effects of acid leaching aluminum from reservoir bottom sediment ...

    African Journals Online (AJOL)

    Three kinds of acid were used to leach bottom sediment soil of water reservoir to diminish aluminum from the soil for preparation of lightweight aggregates. Three concentrations were used in these investigations, including 1, 2 and 5 N. Operating temperatures were set at 25, 50, 70 and 90 celsius. Measuring took place in ...

  13. Trace Metals Distribution in Fish Tissues, Bottom Sediments and ...

    African Journals Online (AJOL)

    ... of tilapia while the lowest concentration with a value of 0.04mg/kg was recorded in tilapia bone. In most of the fish samples, cadmium concentration was found to be above the maximum tolerable values provided by international institutions. Keywords: Trace metals, Fish Tissues, Water, Bottom sediments, Okumeshi River ...

  14. Processed bottom ash for replacing fine aggregate in making high-volume fly ash concrete

    Directory of Open Access Journals (Sweden)

    Antoni

    2017-01-01

    Full Text Available Bottom ash is a coal plant by-product that is abundant and underutilized. There is the potential use of bottom ash as a fine aggregate replacement in concrete mixtures; however, the problems of water absorption and uniformity of quality of the material need to be overcome first. In this study, bottom ash was treated by sieve separation and pounding to smaller particle size for use as a sand substitute. The physical and chemical characteristics of bottom ash were tested after treatment including water absorption, sieve analysis, and fineness modulus. Highvolume fly ash (HVFA mortar specimens were made and the compressive strength and flowability test using bottom ash after treatment are compared with that of the sand specimen. Low water to cementitious ratio was used to ensure higher strength from the cementitious paste and superplasticizer demand was determined for each treatment. The result showed that bottom ash can be used as fine aggregate replacement material. Sieve separation of the bottom ash could produce 75% of the compressive strength compared with the control sand specimen, whereas pounded bottom ash could have up to 96% of the compressive strength of the control specimen. A 28-day compressive strength of 45 MPa was achievable with 100% replacement of fine aggregate with bottom ash.

  15. A method for treating bottom ash

    NARCIS (Netherlands)

    Rem, P.C.; Van Craaikamp, H.; Berkhout, S.P.M.; Sierhuis, W.; Van Kooy, L.A.

    2007-01-01

    A method for treating bottom ash from a waste incineration plant. The invention relates in particular to a method for treating bottom ash from a domestic waste incineration plant. In accordance with the invention bottom ash having a size ranging up to 2 mm is treated by removing a previously

  16. BC Hydro triple bottom line report 2002

    Energy Technology Data Exchange (ETDEWEB)

    Anon

    2002-08-01

    British Columbia Hydro (BC Hydro) published this document which measures the environmental, social and economic performance of the company. It is a complement to BC Hydro's 2002 Annual Report. The report was prepared to better understand the company's business in terms of its commitment to being an environmentally, socially, and economically responsible company (the three bottom lines). BC Hydro proved its ability to integrate the three bottom lines in decision making processes by carefully examining the environmental, social and economical impacts of programs such as Power Smart, Green and Alternative Energy, and Water Use Planning. All indicators point to BC Hydro achieving its commitment of providing a minimum of 10 per cent of new demand through 2010 with new green energy sources. Water Use Plans were developed for hydroelectric generating stations, and they should all be in place by 2003. Efficiencies realised through the Power Smart program offset the increases in greenhouse gas associated with increased energy demand. Juvenile sturgeon raised in a hatchery were released into the Columbia River in May 2002. The completion of a 40-kilometre trail on the Sunshine Coast was helped by a financial contribution from BC Hydro in the amount of 23,000 dollars. Safety improvements were implemented at eight facilities, such as dam remediation, dam surveillance and instrumentation updates. Scholarships were awarded across the province, along with additional donations to non-profit organizations. Co-op positions were provided for 150 students. Internal energy efficiency programs were successful. Planning is under way for significant maintenance work and equipment replacement projects as the transmission and distribution infrastructure ages. The number of reported indicators was expanded this year. In turn, they were aligned with the revised Global Reporting Initiative (GRI) guidelines. tabs.

  17. BC Hydro triple bottom line report 2002

    International Nuclear Information System (INIS)

    Anon

    2002-08-01

    British Columbia Hydro (BC Hydro) published this document which measures the environmental, social and economic performance of the company. It is a complement to BC Hydro's 2002 Annual Report. The report was prepared to better understand the company's business in terms of its commitment to being an environmentally, socially, and economically responsible company (the three bottom lines). BC Hydro proved its ability to integrate the three bottom lines in decision making processes by carefully examining the environmental, social and economical impacts of programs such as Power Smart, Green and Alternative Energy, and Water Use Planning. All indicators point to BC Hydro achieving its commitment of providing a minimum of 10 per cent of new demand through 2010 with new green energy sources. Water Use Plans were developed for hydroelectric generating stations, and they should all be in place by 2003. Efficiencies realised through the Power Smart program offset the increases in greenhouse gas associated with increased energy demand. Juvenile sturgeon raised in a hatchery were released into the Columbia River in May 2002. The completion of a 40-kilometre trail on the Sunshine Coast was helped by a financial contribution from BC Hydro in the amount of 23,000 dollars. Safety improvements were implemented at eight facilities, such as dam remediation, dam surveillance and instrumentation updates. Scholarships were awarded across the province, along with additional donations to non-profit organizations. Co-op positions were provided for 150 students. Internal energy efficiency programs were successful. Planning is under way for significant maintenance work and equipment replacement projects as the transmission and distribution infrastructure ages. The number of reported indicators was expanded this year. In turn, they were aligned with the revised Global Reporting Initiative (GRI) guidelines. tabs

  18. Perspectives on Geoacoustic Inversion of Ocean Bottom Reflectivity Data

    Directory of Open Access Journals (Sweden)

    N. Ross Chapman

    2016-09-01

    Full Text Available This paper focuses on acoustic reflectivity of the ocean bottom, and describes inversion of reflection data from an experiment designed to study the physical properties and structure of the ocean bottom. The formalism of Bayesian inference is reviewed briefly to establish an understanding of the approach for inversion that is in widespread use. A Bayesian inversion of ocean bottom reflection coefficient versus angle data to estimate geoacoustic model parameters of young oceanic crust is presented. The data were obtained in an experiment to study the variation of sound speed in crustal basalt with age of the crust at deep water sites in the Pacific Ocean where the sediment deposits overlying the basalt are very thin. The inversion results show that sound speed of both compressional and shear waves is increasing with crustal age over the track of the experiment where age increased from 40 to 70 million years.

  19. OIL DECONTAMINATION OF BOTTOM SEDIMENTS EXPERIMENTAL WORK RESULTS

    Directory of Open Access Journals (Sweden)

    Lushnikov Sergey V.

    2006-08-01

    Full Text Available This article presents the results of experimental work during 2004-2005 on oil decontamination of bottom sediments of Lake Schuchye, situated in the Komi Republic (Northern Russia. The cause of thecontamination were huge oil spills occurred after a series of accidental ruptures on the Harjaga-Usinsk and Vozej-Usinsk oil-pipe lines in 1994. Flotation technology was used for the cleaning of bottom sediments.157 tons of crude oil were removed during the course of 2-year experimental work from an area of 4,1 ha.The content of aliphatic and alicyclic oil hydrocarbons was reduced from 53,3 g/kg to 2,2 g/kg, on average.Hydrobiological investigations revealed that bottom sediments started to be inhabited by benthos organisms, dominantly Oligochaeta. Besides Oligochaeta, Chironomidae maggots and Bivalvia were detected. Theappearance of Macrozoobenthos organisms can serve as a bioindicator of water quality.

  20. Measuring Sandy Bottom Dynamics by Exploiting Depth from Stereo Video Sequences

    DEFF Research Database (Denmark)

    Musumeci, Rosaria E.; Farinella, Giovanni M.; Foti, Enrico

    2013-01-01

    in the study of the final equilibrium conditions of sea bottoms in the presence of water flows. Results obtained by processing data acquired in hydraulic laboratory confirm the effectiveness of the system which makes simple and fast the understanding of the sandy bottom dynamics and the related equilibrium...

  1. Influence of break structures on the distribution of radionuclides in bottom sediments of the Kyiv reservoir

    International Nuclear Information System (INIS)

    Shestopalov, V.M.; Lyal'ko, V.I.; Fedorovskij, A.D.; Sirenko, L.A.; Khodorovskij, A.Ya.

    2000-01-01

    We study the distribution of radionuclides in bottom sediments of the Kyiv reservoir on the basis of research of adjacent territory break - block structures with deciphering space-born images and ground measurements and forecast the occurrence of extreme situations due to the redistribution of bottom water flows and sediments of radionuclides

  2. Sedimentation and near-bottom currents in the South-Western Atlantic

    Science.gov (United States)

    Emelyanov, Emelyan M.

    2008-01-01

    The aims of the paper are: 1) to study the bottom relief and Late Quaternary bottom sediments of the South-Western Atlantic from the Amazon cone to the Vema Channel and Rio Grande Rise, and 2) to reconstruct recent and palaeo-Antarctic near-bottom currents (AABW). For this purpose, we used three main Parasound seismic profiles: 30 cores (up to 500 cm in length), the nanoplankton stratigraphy of 9 cores from the Brazilian lithological profile (along 24 °W), and literature sources. No soft sedimentes were found in the Vema channel; the bottom of the channel is acoustically "hard". Our geological data confirm that AABW flows mainly through this channel. The velocity of this flow should be higher than 100 cm.s-1. Only this strong current is able to rewash not only soft Holocene sediments, but also consolidated Quaternary deposits. Soft layered sediments occur at a depth less than 4200 m in the Hunter channel. Consequently, the AABW is able to flow from the Argentine Basin to the Brazil Basin only at a depth of more than 4200 m in this channel. Brown red clay or yellowish gray miopelagic clay prevail in the Brazil Deep. The age of red clay in the cores is different: Early or Late Pleistocene, or Holocene. Clay was rewashed and re-deposited in many areas of the deep. This means that the hydrodynamics sometimes was very active at a depth of 4000-5000 m in the Brazil Deep. The presence of conturite and turbidite interlayers in the red clay of the S. America continental base confirms the occurrence of a strong jet of the AABW (Deep Western Boundary current - DWBC) here. Antarctic and other diatoms were brought by AABW from Antarctica up to 10-5 °S. An unusual Pleistocene Ethmodiscus rex ooze was discovered at the latitude of 20 °S. Our data confirm the occurrence in the area between 10-5 °S of two mid-oceanic channels, one of them (EMOC) being located on a large sedimentary swell. The AABW in the cross-section from the Amazon River to the MAR flows through the Nara

  3. Area-intensive bottom culture production of blue mussels, Mytilus edulis (L.)

    DEFF Research Database (Denmark)

    Christensen, Helle Torp

    it is therefore necessary to focus on area-intensive production methods for mussel exploitation. For that purpose bottom culture production of blue mussels is relevant. Despite a long tradition for bottom culturing in Europe the method is still de-pendent on natural conditions, such as recruitment, food...... insights in biological mechanisms can be used as a tool to develop and optimize bottom culture production methods. The study was addressed through the following questions: 1) How can the seed mussel source in bottom culturing be supported? 2) How can survival of mussels in bottom culturing be improved......? And 3) How does bottom culture practice support an area-intensive exploitation of blue mussels? To answer the questions four experimental studies were conducted. Results from a laboratory- and a manipulated field experiment showed that blue mussels collected on sus-pended long line cultures in the water...

  4. Community-Level Sanitation Coverage More Strongly Associated with Child Growth and Household Drinking Water Quality than Access to a Private Toilet in Rural Mali.

    Science.gov (United States)

    Harris, Michael; Alzua, Maria Laura; Osbert, Nicolas; Pickering, Amy

    2017-06-20

    Sanitation access can provide positive externalities; for example, safe disposal of feces by one household prevents disease transmission to households nearby. However, little empirical evidence exists to characterize the potential health benefits from sanitation externalities. This study investigated the effect of community sanitation coverage versus individual household sanitation access on child health and drinking water quality. Using a census of 121 villages in rural Mali, we analyzed the association of community latrine coverage (defined by a 200 m radius surrounding a household) and individual household latrine ownership with child growth and household stored water quality. Child height-for-age had a significant and positive linear relationship with community latrine coverage, while child weight-for-age and household water quality had nonlinear relationships that leveled off above 60% coverage (p sanitation access of surrounding households was more important than private latrine access for protecting water quality and child health.

  5. Infaunal macrobenthic community of soft bottom sediment in a tropical shelf

    Digital Repository Service at National Institute of Oceanography (India)

    Jayaraj, K.A; Jacob, J.; DineshKumar, P.K.

    Studies of benthic communities in tropical shelf waters are limited. In this study, we deal with the infaunal benthic community of soft bottom sediment of the tropical eastern Arabian Sea shelf. Benthic macroinfauna was sampled with a Smith...

  6. Application of solidified sea bottom sediments into environmental bioremediation materials

    Directory of Open Access Journals (Sweden)

    Ahmed H.A. Dabwan

    2017-05-01

    Full Text Available Since dredged sea bottom sediments normally give off a horrible smell, the limitation of disposal places has become a serious problem in Japan. Hence, development of an alternative system to readily treat dredged sea bottom sediments is therefore needed. The development of “value-added” reused products from these sediments offers particular benefits both in terms of resource recovery and protection of the environment. We developed an in situ solidification system for the treatment of sea bottom sediments, the “Hi-Biah-System (HBS”. Firstly, this review deals with solidified sea bottom sediments for the construction of an artificial tidal flat in Ago Bay, Japan. The environmental conditions (pH, oxidation–reduction potential (ORP, acid volatile sulphide (AVS, loss on ignition (LOI, water content (WC, chemical oxygen demand (COD, total organic carbon (TOC, total nitrogen (T-N, chlorophyll a and particle size were then monitored in the constructed tidal flat. The number of benthos individuals and growth of short-necked clams (Ruditapes philippinarum in the artificial tidal flat were also evaluated. The environmental conditions, number of benthos individuals and growth of short-necked clams in the artificial tidal flat were shown to be similar to those observed in a natural tidal flat. Next, the potential use of solidified sea bottom sediments as soil parent material in the germination/growth of seagrass is presented. The soil parent material consisting of solidified sediments obtained using HBS plus soil conditioner and hardener seems to be effective for the germination of Zostera marina. The best growth after six months was observed in plants grown in soil parent material consisting of a mixture of solidified sediments and the sand by weight ration 70:30. The present study may suggest the possible application of solidified sea bottom sediments into growth of other plants.

  7. Plasmonic nanoparticles for a bottom-up approach to fabricate optical metamaterials

    Science.gov (United States)

    Dintinger, José; Scharf, Toralf

    2012-03-01

    We investigate experimentally metallic nanoparticle composites fabricated by bottom-up techniques as potential candidates for optical metamaterials. Depending on the plasmonic resonances sustained by individual NPs and their nanoscale organization into larger meta-atoms, various properties might emerge. Here, the focus of our contribution is on the fabrication and optical characterization of silver NP clusters with a spherical shape. We start with the characterisation of the "bulk" dielectric constants of silver NP inks by spectroscopic ellipsometry for different nanoparticle densities (i.e from strongly diluted dispersions to solid randomly packed films). The inks are then used to prepare spherical nanoparticle clusters by an oil-in water emulsion technique. The study of their optical properties demonstrates their ability to support Mie resonances in the visible. These resonances are associated with the excitation of a magnetic dipole, which constitutes a prerequisite to the realization of metamaterials with negative permeability.

  8. Coal liquefaction with subsequent bottoms pyrolysis

    Science.gov (United States)

    Walchuk, George P.

    1978-01-01

    In a coal liquefaction process wherein heavy bottoms produced in a liquefaction zone are upgraded by coking or a similar pyrolysis step, pyrolysis liquids boiling in excess of about 1000.degree. F. are further reacted with molecular hydrogen in a reaction zone external of the liquefaction zone, the resulting effluent is fractionated to produce one or more distillate fractions and a bottoms fraction, a portion of this bottoms fraction is recycled to the reaction zone, and the remaining portion of the bottoms fraction is recycled to the pyrolysis step.

  9. Community-Level Sanitation Coverage More Strongly Associated with Child Growth and Household Drinking Water Quality than Access to a Private Toilet in Rural Mali

    Science.gov (United States)

    2017-01-01

    Sanitation access can provide positive externalities; for example, safe disposal of feces by one household prevents disease transmission to households nearby. However, little empirical evidence exists to characterize the potential health benefits from sanitation externalities. This study investigated the effect of community sanitation coverage versus individual household sanitation access on child health and drinking water quality. Using a census of 121 villages in rural Mali, we analyzed the association of community latrine coverage (defined by a 200 m radius surrounding a household) and individual household latrine ownership with child growth and household stored water quality. Child height-for-age had a significant and positive linear relationship with community latrine coverage, while child weight-for-age and household water quality had nonlinear relationships that leveled off above 60% coverage (p water quality were not associated with individual household latrine ownership. The relationship between community latrine coverage and child height was strongest among households without a latrine; for these households, each 10% increase in latrine coverage was associated with a 0.031 (p-value = 0.040) increase in height-for-age z-score. In this study, the level of sanitation access of surrounding households was more important than private latrine access for protecting water quality and child health. PMID:28514143

  10. Wet physical separation of MSWI bottom ash

    NARCIS (Netherlands)

    Muchova, L.

    2010-01-01

    Bottom ash (BA) from municipal solid waste incineration (MSWI) has high potential for the recovery of valuable secondary materials. For example, the MSWI bottom ash produced by the incinerator at Amsterdam contains materials such as non-ferrous metals (2.3%), ferrous metals (8-13%), gold (0.4 ppm),

  11. Bottom ash test section evaluation Erwinville, LA.

    Science.gov (United States)

    2009-02-01

    Bottom ash is a by-product of the energy industry and the residual of burning coal in a kiln : firing process. Bottom ash is black and the consistency of coarse sand with gravel clinker : traces. The product is used in other states as embankment mate...

  12. Development of Crashworthy Bottom and Side Structures

    DEFF Research Database (Denmark)

    Naar, H.; Kujala, P.; Simonsen, Bo Cerup

    2002-01-01

    structures. The first structure is a conventional double bottom. In the second structure (presently protected through a patent) the bottom plating is stiffened with hat-profiles instead of bulb profiles. In the third structure the outer shell is an all-steel sandwich panel. In the fourth structure the bottom......The purpose of this work is to compare the resistance to damage of various types of double bottom structures in a stranding event. The results can also be interpreted as the crashworthiness of side structures penetrated by a striking vessel in a collision event. The comparative analyses are made...... by use of a commercial, explicit finite element program. The ship bottom is loaded with a conical indenter with a rounded tip, which is forced laterally into the structures in different positions. The aim is to compare resistance forces, energy absorption and penetration to fracture for four different...

  13. A ocean bottom vector magnetometer

    Science.gov (United States)

    Wang, Xiaomei; Teng, Yuntian; Wang, Chen; Ma, Jiemei

    2017-04-01

    The new development instrument with a compact spherical coil system and Overhauser magnetometer for measuring the total strength of the magnetic field and the vectors of strength, Delta inclination - Delta declination, meanwhile we also use a triaxial fluxgate instrument of the traditional instrument for geomagnetic vector filed measurement. The advantages of this method are be calibrated by each other and get good performances with automatic operation, good stability and high resolution. Firstly, a brief description of the instrument measurement principles and the key technologies are given. The instrument used a spherical coil system with 34 coils to product the homogeneous volume inside the coils which is large enough to accommodate the sensor of Overhauser total field sensor; the rest of the footlocker-sized ocean-bottom vector magnetometer consists of equipment to run the sensors and records its data (batteries and a data logger), weight to sink it to the sea floor, a remote-controlled acoustic release and flotation to bring the instrument back to the surface. Finally, the accuracy of the instrument was tested in the Geomagnetic station, and the measurement accuracies of total strength and components were better than 0.2nT and 1nT respectively. The figure 1 shows the development instrument structure. it includes six thick glass spheres which protect the sensor, data logger and batteries from the pressures of the deep sea, meanwhile they also provide recycling positive buoyancy; To cushion the glass, the spheres then go inside yellow plastic "hardhats". The triaxial fluxgate is inside No.1 glass spheres, data logger and batteries are inside No.2 glass spheres, the new vector sensor is inside No.3 glass spheres, acoustic communication unit is inside No.4 glass spheres, No.5 and No.6 glass spheres are empty which only provide recycling positive buoyancy. The figure 2 shows the development instrument Physical photo.

  14. Bottom-up effects on attention capture and choice

    DEFF Research Database (Denmark)

    Peschel, Anne; Orquin, Jacob Lund; Mueller Loose, Simone

    Attention processes and decision making are accepted to be closely linked together because only information that is attended to can be incorporated in the decision process. Little is known however, to which extent bottom-up processes of attention affect stimulus selection and therefore...... the information available to form a decision. Does changing one visual cue in the stimulus set affect attention towards this cue and what does that mean for the choice outcome? To address this, we conducted a combined eye tracking and choice experiment in a consumer choice setting with visual shelf simulations...... of different product categories. Surface size and visual saliency of a product label were manipulated to determine bottom-up effects on attention and choice. Results show a strong and significant increase in attention in terms of fixation likelihood towards product labels which are larger and more visually...

  15. Photoemission mechanism of water-soluble silver nanoclusters: ligand-to-metal-metal charge transfer vs strong coupling between surface plasmon and emitters.

    Science.gov (United States)

    Chen, Yuting; Yang, Taiqun; Pan, Haifeng; Yuan, Yufeng; Chen, Li; Liu, Mengwei; Zhang, Kun; Zhang, Sanjun; Wu, Peng; Xu, Jianhua

    2014-02-05

    Using carboxylate-protected silver nanoclusters (Ag-carboxylate NCs) as a model, we separately investigated the contribution of the ligand shell and the metal core to understand the nature of photoluminescence of Ag NCs. A new Ag(0)NCs@Ag(I)-carboxylate complex core-shell structural model has been proposed. The emission from the Ag-carboxylate NCs could be attributed to ligand-to-metal-metal charge transfer from Ag(I)-carboxylate complexes (the oxygen atom in the carboxylate ligands to the Ag(I) ions) to the Ag atoms and subsequent radiative relaxation. Additionally, we found that the emission wavelength of the Ag NCs depends on the excitation wavelength implying a strong coupling between surface plasmon and emitter in Ag NCs. The strong coupling between the surface plasmon and the emitter determines the quantum yield and lifetime. The emission mechanism of Ag NCs and its relation to the organic templates and metal cores were clearly clarified. The results should stimulate additional experimental and theoretical research on the molecular-level design of luminescent metal probes for optoelectronics and other applications.

  16. Evaluation of different approaches to quantify strong organic acidity and acid-base buffering of organic-rich surface waters in Sweden.

    Science.gov (United States)

    Köhler, Stephan; Hruska, Jakub; Jönsson, Jörgen; Lövgren, Lars; Lofts, Stephen

    2002-11-01

    The role of organic acids in buffering pH in surface waters has been studied using a small brownwater stream (26mg L(-1) TOC) draining a forested catchment in Northern Sweden. Under the conditions of elevated pressure of CO2 stream field pH was changed between 3.5 and 6.1 during the acidification and alkalinization experiment. Acid-base characteristics of the natural organic matter were also determined using a high precision potentiometric method for a concentrated sample from the same stream. We compared the predictions from the Windermere Humic Aqueous Model (WHAM Model V), a model derived from the potentiometric titration (diprotic/monoprotic acid model) and a previously derived triprotic acid model which only uses alkalinity and TOC as input variables. The predicted buffering characteristics of all three models are very similar in the pH range 4.5-7 which suggests that during routine analysis alkalinity and TOC are sufficient to give a good estimate of organic acid anion charge contribution in a large range of surface waters. A slightly adjusted version of WHAM V successfully describes the organic charge contribution in a large number of sampled surface water lakes, which were previously used to calibrate the triprotic model.

  17. What a drag: Quantifying the global impact of chronic bottom trawling on continental shelf sediment

    Science.gov (United States)

    Oberle, Ferdinand K.J.; Storlazzi, Curt; Hanebuth, Till J.J.

    2016-01-01

    Continental shelves worldwide are subject to intense bottom trawling that causes sediment to be resuspended. The widely used traditional concepts of modern sedimentary transport systems on the shelf rely only on estimates for naturally driven sediment resuspension such as through storm waves, bottom currents, and gravity-driven flows but they overlook a critical anthropogenic factor. The strong influence of bottom trawling on a source-to-sink sediment budget is explored on the NW Iberian shelf. Use of Automated Information System vessel tracking data provides for a high-resolution vessel track reconstruction and the accurate calculation of the spatial distribution of bottom trawling intensity and associated resuspended sediment load. The mean bottom trawling-induced resuspended sediment mass for the NW Iberian shelf is 13.50 Mt yr− 1, which leads to a six-fold increase in off-shelf sediment transport when compared to natural resuspension mechanisms. The source-to-sink budget analysis provides evidence that bottom trawling causes a rapid erosion of the fine sediment on human time scales. Combining global soft sediment distribution data of the shelves with worldwide bottom trawling intensity estimates we show that the bottom trawling-induced resuspended sediment mass amounts to approximately the same mass of all sediment entering the shelves through rivers. Spatial delineations between natural and anthropogenic sediment resuspension areas are presented to aid in marine management questions.

  18. Properties of cold-bonded lightweight artificial aggregate containing bottom ash with different curing regime

    Science.gov (United States)

    Mohamad Ibrahim, Norlia; Nizar Ismail, Khairul; Che Amat, Roshazita; Mohamad Ghazali, Mohamad Iqbal

    2018-03-01

    Cold-bonded pelletizing technique is frequently used in aggregate manufacturing process as it can minimise the energy consumption. It has contributed to both economical and environmental advantages because it helps to reduce the gas emissions problems. Bottom ash collected from municipal solid waste incineration (MSWI) plant was selected as raw material in this study and was utilised as a partial replacement for cement for artificial aggregate production. Several percentage of ash replacement was selected ranged from 10 to 50%. Aggregate pellets were subjected to different types of curing condition which is room-water (RW), room-room (RR), oven-room (OR) and oven-water (OW) condition. Properties of aggregate pellets were examined to obtain its density, water absorption, aggregate impact value (AIV) and specific gravity (SG). The results indicated that the most efficient curing regime is by exposing the aggregate in RW condition. The optimum aggregate was selected at 20% where it has satisfied the required density of 739.5kg/m3, and classified as strong aggregate with AIV 14. However, the water absorption of aggregate increased proportionately with the increment of ash content.

  19. Imaging Reservoir Siltation and Quaternary Stratigraphy Beneath the Mactaquac Headpond by Acoustic and Ground Penetrating Radar Sub-bottom Imaging

    Science.gov (United States)

    Grace, M.; Butler, K. E.; Peter, S.; Yamazaki, G.; Haralampides, K.

    2016-12-01

    The Mactaquac Hydroelectric Generating Station, located on the Saint John River in New Brunswick, Canada, is approaching the end of its life due to deterioration of the concrete structures. As part of an aquatic ecosystem study, designed to support a decision on the future of the dam, sediment in the headpond, extending 80 km upriver, is being examined. The focus of this sub-study lies in (i) mapping the thickness of sediments that have accumulated since inundation in 1968, and (ii) imaging the deeper glacial and post-glacial stratigraphy. Acoustic sub-bottom profiling surveys were completed during 2014 and 2015. An initial 3.5 kHz chirp sonar survey proved ineffective, lacking in both resolution and depth of the penetration. A follow-up survey employing a boomer-based "Seistec" sediment profiler provided better results, resolving sediment layers as thin as 12 cm, and yielding coherent reflections from the deeper Quaternary sediments. Post-inundation sediments in the lowermost 25 km of the headpond, between the dam and Bear Island, are interpreted to average 26 cm in thickness with the thickest deposits (up to 65 cm) in deep water areas overlying the pre-inundation riverbed west of Snowshoe Island, and south and east of Bear Island. A recent coring program confirmed the presence of silty sediment and showed good correlation with the Seistec thickness estimates. In the 15 km stretch upriver of Bear Island to Nackawic, the presence of gas in the uppermost sediments severely limits sub-bottom penetration and our ability to interpret sediment thicknesses. Profiles acquired in the uppermost 40 km reach of the headpond, extending to Woodstock, show a strong, positive water bottom reflection and little to no sub-bottom penetration, indicating the absence of soft post-inundation sediment. Deeper reflections observed within 5 km of the dam reveal a buried channel cut into glacial till, extending up to 20 m below the water bottom. Channel fill includes a finely laminated

  20. On the near-bottom variability in the northwestern Weddell Sea

    Science.gov (United States)

    Schröder, M.; Hellmer, H. H.; Absy, J. M.

    The thermohaline data from the first Brazilian hydrographic cruise to the northwestern Weddell Sea (AR XVIII) revealed significant near-bottom changes in water-column properties over seasonal and interannual time scales. Favorable ice conditions in 2000 allowed a dense station coverage of the area including the main pathways for Weddell Sea deep and bottom waters. The new results are compared with the data from the 1998 German cruise ANT XV/4 and other historical data. A warming of the bottom layer was discovered that was more attributable to short-term seasonal or interannual fluctuations in the formation of cold bottom water than to a long-term trend. There was both consistency and variation between and within seasons. Invariant bottom-water characteristics were observed in different seasons (summer/winter), and variable bottom-water characteristics were observed in the same season (summer) at the same locations. This reduces the possibility of a dominant seasonal effect. Instead, we propose that the intermittent behavior of small cold-water sources along the Weddell Sea's periphery causes the variability measured in the deep northwestern Weddell Sea. The observed variability has consequences for the water-mass export across the South Scotia Ridge, as the absence of the fresher/lighter Weddell Sea Bottom Water south of South Orkney Plateau during AR XVIII might be linked to a reduced ventilation of the deep Scotia Sea. The results of this study show the need for ongoing efforts for establishing a long-term monitoring of this region with global importance.

  1. Adsorption of 90Sr and 90Y by bottom-set beds in the Atlantic ocean

    International Nuclear Information System (INIS)

    Gromov, V.V.; Shakhova, N.F.; Emel'yanov, E.M.

    1978-01-01

    The behaviour of 90 Sr and 90 Y has been studied in an adsorption system of sea water-bottom-set beds of the Atlantic ocean (red clay; pelitic silt). It has been shown that strontium is present in the sea water in one form, viz, Sr 2+ . Adsorption of 90 Sr with bottom-set beds follows the ion-exchange mechanism. Yttrium is present in the sea water at least three forms (two absorbable and one non-absorbable). Yttrium-90 adsorption is an irreversible process and only about 10% 90 Y is desorbed by the sea water from red clay and silt

  2. Methods of analysis by the U.S. Geological Survey National Water Quality Laboratory : determination of organochlorine pesticides and polychlorinated biphenyls in bottom and suspended sediment by gas chromatography with electron-capture detection

    Science.gov (United States)

    Noriega, Mary C.; Wydoski, Duane S.; Foreman, William T.

    2004-01-01

    A method applicable for the determination of 19 organochlorine (OC) pesticides, including total toxaphene as a complex mixture, and 3 polychlorinated biphenyl (PCB) mixtures as Aroclor equivalents--Aroclor 1016/1242, 1254, and 1260--in soil, aquatic bottom sediment, and suspended sediment is described. Method performance data are presented. The solvent system is designed to extract simultaneously selected OC pesticides and PCBs from the same sample matrix. The compounds are extracted by conventional Soxhlet extraction with dichloromethane, followed by partial isolation using gel permeation chromatography (GPC) to remove inorganic sulfur and large naturally present molecules from the sediment extract. The aliquot of extract collected from the GPC for OCs (OC pesticides and PCBs) is split into two sample fractions by alumina/silica combined-column chromatography, followed by Florisil adsorption chromatography to remove interfering compounds in the second fraction. The OC fractions are analyzed by dual capillary-column gas chromatography with electron-capture detection (GC/ECD). This report is limited to the determination of selected OC pesticides and PCBs by GC/ECD using this method. Interim reporting levels (IRLs) have been set at 0.400 to 3.12 micrograms per kilogram for 18 individual OC pesticides, 200 micrograms per kilogram for toxaphene, and 4.04 to 4.68 micrograms per kilogram for the PCBs, based on a sample size of 25-gram equivalent dry weight. These reporting levels may change following additional determinations of method detection limits.

  3. Workability and strength of lignite bottom ash geopolymer mortar.

    Science.gov (United States)

    Sathonsaowaphak, Apha; Chindaprasirt, Prinya; Pimraksa, Kedsarin

    2009-08-30

    In this paper, the waste lignite bottom ash from power station was used as a source material for making geopolymer. Sodium silicate and sodium hydroxide (NaOH) were used as liquid for the mixture and heat curing was used to activate the geopolymerization. The fineness of bottom ash, the liquid alkaline/ash ratio, the sodium silicate/NaOH ratio and the NaOH concentration were studied. The effects of the additions of water, NaOH and napthalene-based superplasticizer on the workability and strength of the geopolymer mortar were also studied. Relatively high strength geopolymer mortars of 24.0-58.0 MPa were obtained with the use of ground bottom ash with 3% retained on sieve no. 325 and mean particle size of 15.7 microm, using liquid alkaline/ash ratios of 0.429-0.709, the sodium silicate/NaOH ratios of 0.67-1.5 and 7.5-12.5M NaOH. The incorporation of water improved the workability of geopolymer mortar more effectively than the use of napthalene-based superplasticizer with similar slight reduction in strengths. The addition of NaOH solution slightly improves the workability of the mix while maintaining the strength of the geopolymer mortars.

  4. USE OF STRONG ACID RESIN PUROLITE C100E FOR REMOVING PERMANENT HARDNESS OF WATER – FACTORS AFFECTING CATIONIC EXCHANGE CAPACITY

    Directory of Open Access Journals (Sweden)

    BOGDAN BANDRABUR

    2013-12-01

    Full Text Available This paper experimentally investigates the performance and capacity of Purolite C100E commercial resin recommended for water softening applications in the food industry. The practical ion exchange capacity and the softening process efficiency are studied in batch mode as a function of the sorption specific process factors. Optimum operation conditions were determined as initial pH 7.1, resin dose 8 g dry resin•L-1, temperature 25 oC, contact time of 360 min, and in those conditions the retention capacity for the Ca2+ ions is 17.18 mg•g-1 that corresponds to a removal efficiency equal to 85.7%.

  5. Testing strong interaction theories

    International Nuclear Information System (INIS)

    Ellis, J.

    1979-01-01

    The author discusses possible tests of the current theories of the strong interaction, in particular, quantum chromodynamics. High energy e + e - interactions should provide an excellent means of studying the strong force. (W.D.L.)

  6. Microplastics in Baltic bottom sediments: Quantification procedures and first results.

    Science.gov (United States)

    Zobkov, M; Esiukova, E

    2017-01-30

    Microplastics in the marine environment are known as a global ecological problem but there are still no standardized analysis procedures for their quantification. The first breakthrough in this direction was the NOAA Laboratory Methods for quantifying synthetic particles in water and sediments, but fibers numbers have been found to be underestimated with this approach. We propose modifications for these methods that will allow us to analyze microplastics in bottom sediments, including small fibers. Addition of an internal standard to sediment samples and occasional empty runs are advised for analysis quality control. The microplastics extraction efficiency using the proposed modifications is 92±7%. Distribution of microplastics in bottom sediments of the Russian part of the Baltic Sea is presented. Microplastic particles were found in all of the samples with an average concentration of 34±10 items/kg DW and have the same order of magnitude as neighbor studies reported. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. Bottom-mounted water level recorder data in the Gulf of Alaska as part of the Inner Shelf Transport and Recycling (ISHTAR) project from 05 July 1985 to 09 October 1988 (NODC Accession 0000349)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Depth, pressure, and water temperature data were collected at fixed platforms in the Gulf of Alaska from July 5, 1985 to October 9, 1988. These data were submitted...

  8. Modeling the formation of the quench product in municipal solid waste incineration (MSWI) bottom ash.

    Science.gov (United States)

    Inkaew, Kanawut; Saffarzadeh, Amirhomayoun; Shimaoka, Takayuki

    2016-06-01

    This study investigated changes in bottom ash morphology and mineralogy under lab-scale quenching conditions. The main purpose was to clarify the mechanisms behind the formation of the quench product/layer around bottom ash particles. In the experiments, the unquenched bottom ashes were heated to 300°C for 1h, and were quenched by warm water (65°C) with different simulated conditions. After having filtered and dried, the ashes were analyzed by a combination of methodologies namely, particle size distribution analysis, intact particle and thin-section observation, X-ray diffractometry, and scanning electron microscope with energy dispersive X-ray spectroscopy. The results indicated that after quenching, the morphology and mineralogy of the bottom ash changed significantly. The freshly quenched bottom ash was dominated by a quench product that was characterized by amorphous and microcrystalline calcium-silicate-hydrate (CSH) phases. This product also enclosed tiny minerals, glasses, ceramics, metals, and organic materials. The dominant mineral phases produced by quenching process and detected by XRD were calcite, Friedel's salt, hydrocalumite and portlandite. The formation of quench product was controlled by the fine fraction of the bottom ash (particle size ash-water reactions and formation of the quench product in the bottom ash was proposed. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. The analysis of bottom forming process for hybrid heating device

    Science.gov (United States)

    Bałon, Paweł; Świątoniowski, Andrzej; Kiełbasa, Bartłomiej

    2017-10-01

    In this paper the authors present an unusual method for bottom forming applicable for various industrial purposes including the manufacture of water heaters or pressure equipment. This method allows for the fabrication of the bottom of a given piece of stainless steel into a pre-determined shape conforming to the DIN standard which determines the most advantageous dimensions for the bottom cross section in terms of working pressure loading. The authors checked the validity of the method in a numerical and experimental way generating a tool designed to produce bottoms of specified geometry. Many problems are encountered during the design and production of parts, especially excessive sheet wrinkling over a large area of the part. The experiment showed that a lack of experience and numerical analysis in the design of such elements would result in the production of highly wrinkled parts. This defect would render the parts impossible to assemble with the cylindrical part. Many tool shops employ a method for drawing elements with a spherical surface which involves additional spinning, stamping, and grading operations, which greatly increases the cost of parts production. The authors present and compare two forming methods for spherical and parabolic objects, and experimentally confirm the validity of the sheet reversing method with adequate pressure force. The applied method produces parts in one drawing operation and in a following operation that is based on laser or water cutting to obtain a round blank. This reduces the costs of tooling manufacturing by requiring just one tool which can be placed on any hydraulic press with a minimum force of 2 000 kN.

  10. Bottom Scour Observed Under Hurricane Ivan

    National Research Council Canada - National Science Library

    Teague, William J; Jarosz, Eva; Keen, Timothy R; Wang, David W; Hulbert, Mark S

    2006-01-01

    Observations that extensive bottom scour along the outer continental shelf under Hurricane Ivan resulted in the displacement of more than 100 million cubic meters of sediment from a 35x15 km region...

  11. Exact Riemann solutions of the Ripa model for flat and non-flat bottom topographies

    Science.gov (United States)

    Rehman, Asad; Ali, Ishtiaq; Qamar, Shamsul

    2018-03-01

    This article is concerned with the derivation of exact Riemann solutions for Ripa model considering flat and non-flat bottom topographies. The Ripa model is a system of shallow water equations accounting for horizontal temperature gradients. In the case of non-flat bottom topography, the mass, momentum and energy conservation principles are utilized to relate the left and right states across the step-type bottom topography. The resulting system of algebraic equations is solved iteratively. Different numerical case studies of physical interest are considered. The solutions obtained from developed exact Riemann solvers are compared with the approximate solutions of central upwind scheme.

  12. Bottom production asymmetries at the LHC

    International Nuclear Information System (INIS)

    Norrbin, E.; Vogt, R.

    1999-01-01

    We present results on bottom hadron production asymmetries at the LHC within both the Lund string fragmentation model and the intrinsic bottom model. The main aspects of the models are summarized and specific predictions for pp collisions at 14 TeV are given. Asymmetries are found to be very small at central rapidities increasing to a few percent at forward rapidities. At very large rapidities intrinsic production could dominate but this region is probably out of reach of any experiment

  13. Bottom production asymmetries at the LHC

    Energy Technology Data Exchange (ETDEWEB)

    Norrbin, E.; Vogt, R.

    1999-01-01

    We present results on bottom hadron production asymmetries at the LHC within both the Lund string fragmentation model and the intrinsic bottom model. The main aspects of the models are summarized and specific predictions for pp collisions at 14 TeV are given. Asymmetries are found to be very small at central rapidities increasing to a few percent at forward rapidities. At very large rapidities intrinsic production could dominate but this region is probably out of reach of any experiment.

  14. Bottom mass from nonrelativistic sum rules at NNLL

    Energy Technology Data Exchange (ETDEWEB)

    Stahlhofen, Maximilian

    2013-01-15

    We report on a recent determination of the bottom quark mass from nonrelativistic (large-n) {Upsilon} sum rules with renormalization group improvement (RGI) at next-to-next-to-leading logarithmic (NNLL) order. The comparison to previous fixed-order analyses shows that the RGI computed in the vNRQCD framework leads to a substantial stabilization of the theoretical sum rule moments with respect to scale variations. A single moment fit (n=10) to the available experimental data yields M{sub b}{sup 1S}=4.755{+-}0.057{sub pert}{+-}0.009{sub {alpha}{sub s}}{+-}0.003{sub exp} GeV for the bottom 1S mass and anti m{sub b}(anti m{sub b})=4.235{+-}0.055{sub pert}{+-}0.003{sub exp} GeV for the bottom MS mass. The quoted uncertainties refer to the perturbative error and the uncertainties associated with the strong coupling and the experimental input.

  15. BOTTOM TYPES IDENTIFICATION IN SHALLOW CORAL REEF ECOSYSTEMS USING IMAGERY SATELLITE DATA

    Directory of Open Access Journals (Sweden)

    MASITA DWI MANDINI MANESSA

    2015-06-01

    Full Text Available Satellite data provide information about spectral signatures of objects in detail, based on the wide range of spectral wavelengths. Bottom types in a coral reef Ecosystems are diverse and each object has a different spectral signature. The aim of this research is to define bottom types using Multispectral and Hyperspectral imagery satellite data. Six processes were applied to Hyperspectral Images to identified bottom types using modification of Analytical Imaging and Geophysics LLC (AIG hyperspectral analysis. The multispectral analysis was focused on correcting water column noise by applying the radiative water column algorithm (Lyzenga, 1978, 1981 and the modified image correction algorithm (Lyzenga et al., 2006. The results showed that multispectral image analysis was able to identify a fine complexity of b bottom types classes with 68.57% overall accuracy. In contrast, Hyperion image identified a coarse complexity of bottom types classes with 61.57% overall accuracy. This low result was caused by low spatial resolution which created a mixing pixel around image of thin and narrow shallow coral reef ecosystem. Spatial resolution, atmosphere and water scattering played an important role in bottom types identification.

  16. Bottom Topographic Changes of Poyang Lake During Past Decade Using Multi-temporal Satellite Images

    Science.gov (United States)

    Zhang, S.

    2015-12-01

    Poyang Lake, as a well-known international wetland in the Ramsar Convention List, is the largest freshwater lake in China. It plays crucial ecological role in flood storage and biological diversity. Poyang Lake is facing increasingly serious water crises, including seasonal dry-up, decreased wetland area, and water resource shortage, all of which are closely related to progressive bottom topographic changes over recent years. Time-series of bottom topography would contribute to our understanding of the lake's evolution during the past several decades. However, commonly used methods for mapping bottom topography fail to frequently update quality bathymetric data for Poyang Lake restricted by weather and accessibility. These deficiencies have limited our ability to characterize the bottom topographic changes and understanding lake erosion or deposition trend. To fill the gap, we construct a decadal bottom topography of Poyang Lake with a total of 146 time series medium resolution satellite images based on the Waterline Method. It was found that Poyang Lake has eroded with a rate of -14.4 cm/ yr from 2000 to 2010. The erosion trend was attributed to the impacts of human activities, especially the operation of the Three Gorge Dams, sand excavation, and the implementation of water conservancy project. A decadal quantitative understanding bottom topography of Poyang Lake might provide a foundation to model the lake evolutionary processes and assist both researchers and local policymakers in ecological management, wetland protection and lake navigation safety.

  17. Gas hydrate quantification from ocean-bottom seismometer data along the continental margin of Western Svalbard.

    Science.gov (United States)

    Chabert, A.; Minshull, T. A.; Westbrook, G. K.; Berndt, C.

    2009-04-01

    The stability of shallow gas hydrate in the Arctic region is expected to be affected by the warming of the bottom-water in the next decades. It is, therefore, important to evaluate how the gas hydrate systems will react to future increases in bottom-water temperature and the impact on climate of the spatial and temporal variability of the release of methane from these reservoirs. As part of the International Polar Year initiative, a multidisciplinary marine expedition was carried out in September 2008 along the continental margin west of Svalbard in the Arctic. One of the objectives was to investigate the extent of the gas hydrate stability zone (GHSZ) along and across the continental slope and to estimate the quantity of methane present using the geophysical properties of methane hydrate- and gas-bearing sediments, which occur in and beneath the GHSZ. Three seismic experiments employing ocean-bottom seismometers (OBS) were carried out across and along the continental margin as part of the project. Seismic data from 13 OBS in closely spaced arrays were acquired from 5 representative sites off west Svalbard, above and below the upper limit of the GHSZ. Two to four OBSs were deployed at each site, with a spacing of 200 m. The high frequency airguns were fired at 5-s intervals, concurrently with the acquisition of multi-channel seismic reflection profiles. The OBSs were equipped with a 3-component 4.5 Hz geophone package and a broadband hydrophone; the data-loggers were operated at 1 kHz sample rate. The OBS experiments were designed to recover P- and S-wave velocities to depths of a few hundreds metres below the seabed in order to estimate the amount of hydrate in the region, hydrate increasing both the P- and S-wave velocities of the sediments in which it is present. The data show clearly recorded P reflections at short offsets, as well as refracted arrivals at larger offsets, from depths of 1 to 2 kilometres below the seabed. S waves, generated by P-S conversion on

  18. Color Fringes Bordering Black Stripes at the Bottom of a Swimming Pool

    Science.gov (United States)

    Fuster, Gonzalo; Rojas, Roberto; Slüsarenko, Viktor

    2016-01-01

    We have observed a nice example of chromatic dispersion due to refraction in water, in the form of color fringes bordering the black stripes that exist at the bottom of a swimming pool. Here we give a qualitative description of the phenomenon, explaining the role of the black stripes and the dispersive index of refraction of water.

  19. Bottom shear stress and salinity distribution in a windy Mediterranean lagoon

    Science.gov (United States)

    Alekseenko, Elena; Roux, Bernard; Kuznetsov, Konstantin

    2017-04-01

    This work concerns the wind influence on bottom shear stress and salinity levels in a Mediterranean semi-enclosed coastal lagoon (Etang de Berre), with respect to a replanting program of Zostera noltii. The MARS3D numerical model is used to analyze the 3D current, salinity and temperature distribution induced by three meteorological, oceanic and anthropogenic forcings in this lagoon. The numerical model has been carefully validated by comparison with daily observations of the vertical salinity and temperature profiles at three mooring stations, for one year. Then, two modelling scenarios are considered. The first scenario (scen.#1), starting with an homogeneous salinity of S=20 PSU and without wind forcing, studies a stratification process under the influence of a periodic seawater inflow and a strong freshwater inflow from an hydropower plant (250 m3/s). Then, in the second scenario (scen.#2), we study how a strong wind of 80 km/h can mix the haline stratification obtained at the end of scen.#1. The most interesting results concern four nearshore replanting areas ; two are situated on the eastern side of EB and two on the western side. The results of scen.#2 show that all these areas are subject to a downwind coastal jet. Concerning bottom salinity, the destratification process is very beneficial; it always remains greater than 12 PSU for a N-NW wind of 80 km/h and a hydropower runoff of 250 m3/s. Special attention is devoted to the bottom shear stress (BSS) for different values of the bottom roughness parameter (for gravels, sands and silts), and to the bottom salinity. BSS presents a maximum near the shoreline and decreases along transects perpendicular to the shoreline. There exists a zone, parallel to the shoreline, where BSS presents a minimum (close to zero). When comparing the BSS value at the four replanting areas with the critical value, BSScr, at which the sediment mobility would occur, we see that for the smaller roughness values (ranging from z0=3.5 e

  20. Bottom-of-sulcus dysplasia: imaging features.

    Science.gov (United States)

    Hofman, Paul A M; Fitt, Gregory J; Harvey, A Simon; Kuzniecky, Ruben I; Jackson, Graeme

    2011-04-01

    Dysplasia at the bottom of a sulcus is a subtle but distinct malformation of cortical development relevant to epilepsy. The purpose of this study was to review the imaging features important to the clinical diagnosis of this lesion. All cases recognized as typical bottom-of-sulcus dysplasia in our comprehensive epilepsy program over the period 2002-2007 were included in the study. In the 20 cases recognized, three major features were identified: cortical thickening at the bottom of a sulcus; a funnel-shaped extension of the lesion toward the ventricular surface, commonly with abnormal signal intensity; and an abnormal gyral pattern related to the bottom-of-sulcus dysplasia, sometimes with a puckered appearance. The pathologic features of the resected lesions were typical of focal cortical dysplasia. Bottom-of-sulcus dysplasia is a distinctive malformation of cortical development that can be diagnosed on the basis of imaging characteristics. Reliable identification of this type of malformation of cortical development is difficult but clinically important because the lesion appears to be highly epileptogenic and because the prognosis for seizure control is excellent after focal resection.

  1. Coal Bottom Ash for Portland Cement Production

    Directory of Open Access Journals (Sweden)

    Cristina Argiz

    2017-01-01

    Full Text Available Because of industrialization growth, the amount of coal power plant wastes has increased very rapidly. Particularly, the disposal of coal bottom ash (CBA is becoming an increasing concern for many countries because of the increasing volume generated, the costs of operating landfill sites, and its potential hazardous effects. Therefore, new applications of coal bottom ash (CBA have become an interesting alternative to disposal. For instance, it could be used as a Portland cement constituent leading to more sustainable cement production by lowering energy consumption and raw material extracted from quarries. Coal fly and bottom ashes are formed together in the same boiler; however, the size and shape of these ashes are very different, and hence their effect on the chemical composition as well as on the mineralogical phases must be studied. Coal bottom ash was ground. Later, both ashes were compared from a physical, mechanical, and chemical point of view to evaluate the potential use of coal bottom ash as a new Portland cement constituent. Both ashes, produced by the same electrical power plant, generally present similar chemical composition and compressive strength and contribute to the refill of mortar capillary pores with the reaction products leading to a redistribution of the pore size.

  2. Developing the new method measuring thickness and quality of bottom sediments in using ultrasonic wave

    Science.gov (United States)

    Ishikawa, Tomonari; Matsumoto, Yoshitaka; Hozumi, Naohiro

    2017-07-01

    Measuring the quality and thickness of bottom sediment that it causes some environmental problem, the shortage of water storage volume and anaerobic zone in the bottom of reservoirs, takes huge costs and long time. The purpose of our research is to develop a new method to measure the thickness and size characteristics of bottom sediment using ultrasonic waves that allow obtaining the quality of it indirectly. This new method applies the echo characteristic of bottom sediment in each particle size using the higher frequency than another method, which uses for measuring geological layer at seabed survey. In this research, we attempted to estimate the particle size of bottom sediment by ultrasonic waves irradiating from two different directions such as horizontal and vertical direction, and compare these experiments. We use sediment that we sampled from the lake bottom classified by particle size. At first, we acquired the results that show a relation between particle size and intensity; the obtained echo intensities, which were observed with oscilloscope, were changed depending on the particle sizes. In addition, peaks, which were obtained by power spectrum analysis, appeared on the same frequency band even though the different particle size. However the relation between the experiments of horizontal and vertical direction is not clear. This research indicated the possibility of estimating the characteristics of each particle size in bottom sediment by ultrasonic waves.

  3. Hydrothermal treatment of MSWI bottom ash forming acid-resistant material.

    Science.gov (United States)

    Etoh, Jiro; Kawagoe, Takeshi; Shimaoka, Takayuki; Watanabe, Koichiro

    2009-03-01

    To recycle municipal solid waste incinerator (MSWI) bottom ash, synthesis of hydrothermal minerals from bottom ash was performed to stabilize heavy metals. MSWI bottom ash was mixed with SiO(2), Al(OH)(3), and Mg(OH)(2) so its chemical composition was similar to that of hydrothermal clay minerals. These solid specimens were mixed with water at a liquid/solid ratio of 5. The reaction temperature was 200 degrees C, and reactions were performed for 24-240h. Generation of kaolinite/smectite mixed-layer clay mineral was found in the samples after the reaction of the mixture of bottom ash, SiO(2), and Mg(OH)(2). Calcium silicate hydrate minerals such as tobermorite and xonotlite were also generated. X-ray powder diffraction suggested the presence of amorphous materials. Leaching tests at various pHs revealed that the concentration of heavy metals in the leachates from MSWI bottom ash hydrothermally treated with SiO(2) and Mg(OH)(2) was lower than that in leachates from non-treated bottom ash, especially under acid conditions. Hydrothermal treatment with modification of chemical composition may have potential for the recycling of MSWI bottom ash.

  4. Accurate ocean bottom seismometer positioning method inspired by multilateration technique

    Science.gov (United States)

    Benazzouz, Omar; Pinheiro, Luis M.; Matias, Luis M. A.; Afilhado, Alexandra; Herold, Daniel; Haines, Seth

    2018-01-01

    The positioning of ocean bottom seismometers (OBS) is a key step in the processing flow of OBS data, especially in the case of self popup types of OBS instruments. The use of first arrivals from airgun shots, rather than relying on the acoustic transponders mounted in the OBS, is becoming a trend and generally leads to more accurate positioning due to the statistics from a large number of shots. In this paper, a linearization of the OBS positioning problem via the multilateration technique is discussed. The discussed linear solution solves jointly for the average water layer velocity and the OBS position using only shot locations and first arrival times as input data.

  5. Mixed-potential Behavior of Nanostructured RuO2 Sensing Electrode of Water Quality Sensors in Strong Alkaline Solutions at a Temperature Range of 9-30° C

    Science.gov (United States)

    Zhuiykov, Serge

    2009-05-01

    Mixed-potential behavior of the water quality monitoring sensors using nanostructured RuO2 sensing electrode (SE) has been observed in strong alkaline solutions at dissolved oxygen (DO) measurements in the temperature range of 9-30° C. This behavior indicated that a Faradaic oxygen reduction reaction becomes not only a one-electron process, which is typical for DO measurements at a neutral pH, but rather multi-step process with superoxide oxygen ions (O2-), OH- and RuO42- ions involvement. The DO sensing characteristics were examined in the pH range of 2.0-13.0. The measured emf at strong alkaline solutions is a mixed potential from the reactions involved RuO42- and OH- ions and DO. Impedance spectroscopy was employed for confirmation the mixed-potential behavior of the sensor. It was also found during experiments that OH- ions influence the response/recovery rate of the SE reactions as the pH of water increases.

  6. Water

    Science.gov (United States)

    ... www.girlshealth.gov/ Home Nutrition Nutrition basics Water Water Did you know that water makes up more ... to drink more water Other drinks How much water do you need? top Water is very important, ...

  7. Biogas--municipal solid waste incinerator bottom ash interactions: sulphur compounds removal.

    Science.gov (United States)

    Ducom, Gaëlle; Radu-Tirnoveanu, Daniela; Pascual, Christophe; Benadda, Belkacem; Germain, Patrick

    2009-07-30

    This study focuses on a new way of reusing municipal solid waste incinerator bottom ash: landfill gas purification before energetic valorisation. A pilot plant was designed and operated on a landfill site located in France (Loire). One kilogram bottom ash is able to sequestrate more than 3.0 g of hydrogen sulphide, 44 mg of methyl mercaptan, and 86 mg of dimethyl sulphide. Hydrogen sulphide retention is probably due to acid-basic reactions conducting to sulphur mineralisation under the form of low solubility metal sulphides. The reaction medium is hydration water. The retention mechanism for methyl mercaptan is probably similar but dimethyl sulphide is most likely retained by physical adsorption. As methane is not retained by bottom ash, the landfill gas energetic content will not be lowered. There seems to be no appreciable difference in these results whether bottom ash is fresh or carbonated. These results are encouraging in the perspective of a field scale application of this biogas treatment process.

  8. Strongly Correlated Topological Insulators

    Science.gov (United States)

    2016-02-03

    Strongly Correlated Topological Insulators In the past year, the grant was used for work in the field of topological phases, with emphasis on finding...surface of topological insulators. In the past 3 years, we have started a new direction, that of fractional topological insulators. These are materials...in which a topologically nontrivial quasi-flat band is fractionally filled and then subject to strong interactions. The views, opinions and/or

  9. Eco-friendly porous concrete using bottom ash aggregate for marine ranch application.

    Science.gov (United States)

    Lee, Byung Jae; Prabhu, G Ganesh; Lee, Bong Chun; Kim, Yun Yong

    2016-03-01

    This article presents the test results of an investigation carried out on the reuse of coal bottom ash aggregate as a substitute material for coarse aggregate in porous concrete production for marine ranch applications. The experimental parameters were the rate of bottom ash aggregate substitution (30%, 50% and 100%) and the target void ratio (15%, 20% and 25%). The cement-coated granular fertiliser was substituted into a bottom ash aggregate concrete mixture to improve marine ranch applications. The results of leaching tests revealed that the bottom ash aggregate has only a negligible amount of the ten deleterious substances specified in the Ministry of Environment - Enforcement Regulation of the Waste Management Act of Republic Korea. The large amount of bubbles/air gaps in the bottom ash aggregate increased the voids of the concrete mixtures in all target void ratios, and decreased the compressive strength of the porous concrete mixture; however, the mixture substituted with 30% and 10% of bottom ash aggregate and granular fertiliser, respectively, showed an equal strength to the control mixture. The sea water resistibility of the bottom ash aggregate substituted mixture was relatively equal to that of the control mixture, and also showed a great deal of improvement in the degree of marine organism adhesion compared with the control mixture. No fatality of fish was observed in the fish toxicity test, which suggested that bottom ash aggregate was a harmless material and that the combination of bottom ash aggregate and granular fertiliser with substitution rates of 30% and 10%, respectively, can be effectively used in porous concrete production for marine ranch application. © The Author(s) 2015.

  10. Strong Cosmic Censorship

    Science.gov (United States)

    Isenberg, James

    2017-01-01

    The Hawking-Penrose theorems tell us that solutions of Einstein's equations are generally singular, in the sense of the incompleteness of causal geodesics (the paths of physical observers). These singularities might be marked by the blowup of curvature and therefore crushing tidal forces, or by the breakdown of physical determinism. Penrose has conjectured (in his `Strong Cosmic Censorship Conjecture`) that it is generically unbounded curvature that causes singularities, rather than causal breakdown. The verification that ``AVTD behavior'' (marked by the domination of time derivatives over space derivatives) is generically present in a family of solutions has proven to be a useful tool for studying model versions of Strong Cosmic Censorship in that family. I discuss some of the history of Strong Cosmic Censorship, and then discuss what is known about AVTD behavior and Strong Cosmic Censorship in families of solutions defined by varying degrees of isometry, and discuss recent results which we believe will extend this knowledge and provide new support for Strong Cosmic Censorship. I also comment on some of the recent work on ``Weak Null Singularities'', and how this relates to Strong Cosmic Censorship.

  11. Analysis of the peach bottom 2 BWR turbine trip experiment by RELAP 5/3.2 code

    Directory of Open Access Journals (Sweden)

    Bousbia-Salah Anis

    2002-01-01

    Full Text Available This paper presents the results of the application of the system of the thermalhydraulic code RELAP5/Mod3.2 in predicting the Peach Bottom Boiling Water Reactor Turbine Trip test. This experiment constitutes a challenge to the capabilities of current computational tools in realistically predicting transient scenarios in nuclear power plants. In fact, it involves strong feedback during the transient between thermalhydraulics and neutronics. In this respect, a reference case was run in order to simulate the interactions between the generated steam line pressure wave propagation and the instantaneous core void distribution. An overall comparison shows good agreement between the code calculations and the experimental data. A series of sensitivity analyses were also performed in order to assess the code prediction features, as well as to identify uncertainties related to the adopted thermalhydraulic parameters used for the plant modelisation.

  12. 49 CFR 179.200-13 - Manway ring or flange, pressure relief device flange, bottom outlet nozzle flange, bottom washout...

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Manway ring or flange, pressure relief device flange, bottom outlet nozzle flange, bottom washout nozzle flange and other attachments and openings. 179....200-13 Manway ring or flange, pressure relief device flange, bottom outlet nozzle flange, bottom...

  13. A resting bottom sodium cooled fast reactor

    International Nuclear Information System (INIS)

    Costes, D.

    2012-01-01

    This follows ICAPP 2011 paper 11059 'Fast Reactor with a Cold Bottom Vessel', on sodium cooled reactor vessels in thermal gradient, resting on soil. Sodium is frozen on vessel bottom plate, temperature increasing to the top. The vault cover rests on the safety vessel, the core diagrid welded to a toric collector forms a slab, supported by skirts resting on the bottom plate. Intermediate exchangers and pumps, fixed on the cover, plunge on the collector. At the vessel top, a skirt hanging from the cover plunges into sodium, leaving a thin circular slit partially filled by sodium covered by argon, providing leak-tightness and allowing vessel dilatation, as well as a radial relative holding due to sodium inertia. No 'air conditioning' at 400 deg. C is needed as for hanging vessels, and this allows a large economy. The sodium volume below the slab contains isolating refractory elements, stopping a hypothetical corium flow. The small gas volume around the vessel limits any LOCA. The liner cooling system of the concrete safety vessel may contribute to reactor cooling. The cold resting bottom vessel, proposed by the author for many years, could avoid the complete visual inspection required for hanging vessels. However, a double vessel, containing support skirts, would allow introduction of inspecting devices. Stress limiting thermal gradient is obtained by filling secondary sodium in the intermediate space. (authors)

  14. Spectroscopy and decays of charm and bottom

    International Nuclear Information System (INIS)

    Butler, J.N.

    1997-10-01

    After a brief review of the quark model, we discuss our present knowledge of the spectroscopy of charm and bottom mesons and baryons. We go on to review the lifetimes, semileptonic, and purely leptonic decays of these particles. We conclude with a brief discussion B and D mixing and rare decays

  15. Police reform from the bottom up

    African Journals Online (AJOL)

    Over the past two decades the theories and strategies associated with institutional reform of the police as public agency have been a source of invigoration for ... Criminology, Faculty of Law at the University of Cape. Town. Elrena van der Spuy*. Elrena.vanderspuy@uct.ac.za. Title: Police reform from the bottom up: officers ...

  16. There's Plenty of Room at the Bottom

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 16; Issue 9. There's Plenty of Room at the Bottom. Richard P Feynman. Classics Volume 16 Issue 9 September 2011 pp 890-905. Fulltext. Click here to view fulltext PDF. Permanent link: http://www.ias.ac.in/article/fulltext/reso/016/09/0890-0905 ...

  17. Bottom fauna of the Malacca Strait

    Digital Repository Service at National Institute of Oceanography (India)

    Parulekar, A.H.; Ansari, Z.A.

    Bottom fauna of Malacca Strait (connecting the Indian Ocean with Pacific) in the depth range of 80 to 1350 m, is dominated by meiofauna which exceeds macrofauna by 12.5 times in weight and by more than 780 times in population density. Standing crop...

  18. Production efficiency of mussel bottom culture

    NARCIS (Netherlands)

    Capelle, Jacob J.

    2017-01-01

    Mussel bottom culture is an extensive type of aquaculture; it depends on natural resources for feed, seed and space. It consists of the translocation of seed from natural beds to designed culture areas, where mussel farmers try to improve production efficiency. Production efficiency is measured by

  19. Habitat modification drives benthic trophic diversity in an intertidal soft-bottom ecosystem

    NARCIS (Netherlands)

    van der Zee, E.M.; Tielens, E.; Holthuijsen, S.; Donadi, S.; Eriksson, B.K.; van der Veer, H.W.; Piersma, T.; Olff, H.; van der Heide, T.

    2015-01-01

    In intertidal soft-bottom ecosystems, ecosystem engineers such as reef-building bivalves, can strongly affect the associated benthic community by providing structure and stabilizing the sediment. Although several engineering species have declined dramatically in the past centuries, the consequences

  20. Phosphorus availability from bottom sediments of lakes using a nuclear technique

    International Nuclear Information System (INIS)

    Flores, F.; Facetti, J.F.

    1991-01-01

    Availability of phosphorus from the bottom sediments of a lake plays an import role in the development of aquatic biota and in the enhancement of eutrophication process. In this work the 31 P↔ 32 P isotopic exchange (E values) technique was applied to assess the potential influence of this phosphorus reservoir on the water quality of Acaray and Yguazu Dams, at the Eastern Region of Paraguay. Samples analyzed were taken from the bottom sediments of the water bodies at different sites as well as from the shores. The method is reliable and yields information of ecological significance

  1. Phosphorus availability from bottom sediments of lakes using a nuclear technique

    International Nuclear Information System (INIS)

    Flores, F.; Facetti, J.F.

    1992-01-01

    Availability of phosphorus from the bottom sediments of a lake plays an import role in the development of aquatic biota and in the enhancement of the eutrophication process. In this work, the 31 P- 32 P isotopic exchange (E values) technique was applied to assess the potential influence of this phosphorus 'reservoir' on the water quality of the Acaray and Yguazu Dams in the Easter Region of Paraguay. Samples analyzed were taken from the bottom sediments of the water body at different sites as well as from the shores. The method is reliable and yields information of potential ecological significance. (author) 14 refs.; 2 tabs

  2. "Triple-bottom-line" assessment of urban stormwater projects.

    Science.gov (United States)

    Taylor, A C; Fletcher, T D

    2006-01-01

    New guidelines have been developed and trialled in Australia to assist urban stormwater managers to assess options for projects that aim to improve urban waterway health. These guidelines help users to examine the financial, ecological and social dimensions of projects (i.e., the so-called "triple-bottom-line"). Features of the assessment process described in the guidelines include use of multi criteria analysis, input from technical experts as well as non-technical stakeholders, and provision of three alternative levels of assessment to suit stormwater managers with differing needs and resources. This paper firstly provides a background to the new guidelines and triple-bottom-line assessment. The assessment methodology promoted in the new guidelines is then briefly summarised. This methodology is compared and contrasted with European guidelines from the "SWARD" project that have been primarily developed for assessing the relative sustainability of options involving urban water supply and sewerage assets. Finally, the paper discusses how assessment methodologies that evaluate the financial, ecological and social dimensions of projects can, under some circumstances, be used to evaluate the relative progress of options for urban water management on a journey towards the widely pursued, but vaguely defined goal of "sustainable development".

  3. Ocean Bottom Seismometers technology: current state and future outlook

    Science.gov (United States)

    Ilinskiy, Dmitry; Ganzha, Oleg

    2016-04-01

    The beginning of 2000s was marked by a significant progress in the development and use of self-pop-up sea-bottom seismic recorders (Ocean Bottom Seismometers). In Russia it was a novel solution developed by the Russian Academy of Sciences Experimental Design Bureau of Oceanological Engineering. This recorder and its clones have been widely used not only for the Earth crust studies, but also for investigations of sub-basalt structures and gas hydrate exploration. And what has happened over the last 10 years? Let us look closely at the second generation of ocean bottom stations developed by Geonodal Solutions (GNS) as an illustration of the next step forward in the sea-bottom acquisition technology. First of all, hardware components have changed dramatically. The electronic components became much smaller, accordingly, the power consumption and electronic self-noise were dropped down significantly. This enabled development of compact station 330 mm in diameter instead of previous 450mm. The weight fell by half, while the autonomy increased up to 90 days due to both decreased energy consumption and increased capacity of the batteries. The dynamic range of recorded seismic data has expended as a result of decreased set noise and the application of 24-bit A/D converters. The instruments dimensions have been reduced, power consumption decreased, clock accuracy was significantly improved. At the same time, development of advanced time reference algorithms enabled to retain instrument accuracy around 1 ms during all the autonomous recording period. The high-speed wireless data transfer technology offered a chance to develop "maintenance-free" station throughout its operation time. The station can be re-used at the different sea bottom locations without unsealing of the deep-water container for data download, battery re-charge, clock synchronization. This noticeably reduces the labor efforts of the personnel working with the stations. This is critically important in field

  4. Strong Arcwise Connectedness

    OpenAIRE

    Espinoza, Benjamin; Gartside, Paul; Kovan-Bakan, Merve; Mamatelashvili, Ana

    2012-01-01

    A space is `n-strong arc connected' (n-sac) if for any n points in the space there is an arc in the space visiting them in order. A space is omega-strong arc connected (omega-sac) if it is n-sac for all n. We study these properties in finite graphs, regular continua, and rational continua. There are no 4-sac graphs, but there are 3-sac graphs and graphs which are 2-sac but not 3-sac. For every n there is an n-sac regular continuum, but no regular continuum is omega-sac. There is an omega-sac ...

  5. Abortion: Strong's counterexamples fail

    DEFF Research Database (Denmark)

    Di Nucci, Ezio

    2009-01-01

    This paper shows that the counterexamples proposed by Strong in 2008 in the Journal of Medical Ethics to Marquis's argument against abortion fail. Strong's basic idea is that there are cases--for example, terminally ill patients--where killing an adult human being is prima facie seriously morally......'s scenarios have some valuable future or admitted that killing them is not seriously morally wrong. Finally, if "valuable future" is interpreted as referring to objective standards, one ends up with implausible and unpalatable moral claims....

  6. Bottom Slamming on Heaving Point Absorber Wave Energy Devices

    DEFF Research Database (Denmark)

    De Backer, Griet; Vantorre, Marc; Frigaard, Peter

    2010-01-01

    Oscillating point absorber buoys may rise out of the water and be subjected to bottom slamming upon re-entering the water. Numerical simulations are performed to estimate the power absorption, the impact velocities and the corresponding slamming forces for various slamming constraints. Three buoy...... occurrence probabilities can be significantly reduced by adapting the control parameters. The magnitude of the slamming load is severely influenced by the buoy shape. The ratio between the peak impact load on the hemisphere and that on the 45 cone is approximately 2, whereas the power absorption is only 4......-8% higher for the 45 degrees cone. This work illustrates the need to include slamming considerations aside from power absorption criteria in the buoy shape design process and the control strategy....

  7. A strong comeback

    International Nuclear Information System (INIS)

    Marier, D.

    1992-01-01

    This article presents the results of a financial rankings survey which show a strong economic activity in the independent energy industry. The topics of the article include advisor turnover, overseas banks, and the increase in public offerings. The article identifies the top project finance investors for new projects and restructurings and rankings for lenders

  8. Ocean Bottom Seismograph Performance during the Cascadia Initiative

    Science.gov (United States)

    Aderhold, K.; Evers, B.

    2015-12-01

    The Ocean Bottom Seismograph Instrument Pool (OBSIP) provides instrumentation and operations support for the Cascadia Initiative community experiment. This experiment investigates geophysical processes across the Cascadia subduction zone through a combination of onshore and offshore seismic data. The recovery of Year 4 instruments in September 2015 marks the conclusion of a multi-year experiment that utilized 60 ocean-bottom seismographs (OBSs) specifically designed for the subduction zone boundary, including shallow/deep water deployments and active fisheries. The new instruments feature trawl-resistant enclosures designed by Lamont-Doherty Earth Observatory (LDEO) and Scripps Institution of Oceanography (SIO) for shallow deployment [water depth ≤ 500 m], as well as new deep-water instruments designed by Woods Hole Oceanographic Institute (WHOI). Existing OBSIP instruments were also deployed along the Blanco Transform Fault and on the Gorda Plate through complementary experiments. Stations include differential pressure gauges (DPG) and absolute pressure gauges (APG). All data collected from the Cascadia, Blanco, and Gorda deployments will be freely available through the Incorporated Research Institutions for Seismology (IRIS) Data Management Center (DMC). The Cascadia Initiative is the largest amphibious seismic experiment undertaken to date and demonstrates an effective structure for community experiments through collaborative efforts from the Cascadia Initiative Expedition Team (CIET), OBSIP (institutional instrument contributors [LDEO, SIO, WHOI] and Management Office [IRIS]), and the IRIS DMC. The successes and lessons from Cascadia are a vital resource for the development of a Subduction Zone Observatory (SZO). To guide future efforts, we investigate the quality of the Cascadia OBS data using basic metrics such as instrument recovery and more advanced metrics such as noise characteristics through power spectral density analysis. We also use this broad and

  9. 90Sr content in the Black Sea bottom sediments after the Chernobyl NPP accident and its use as a radiotracer for an assessment of bottom settlement rate

    International Nuclear Information System (INIS)

    Mirzoyeva, N. Y.; Egorov, V. N.; Polikarpov, G. G.

    2006-01-01

    The increase of 9 0Sr concentrations in the Black Sea bottom sediments along to western coast of the Black Sea and south part of Crimea was observed in 1987-1988 years. To our opinion, it was connected with hydrological processes (for example, currents), occurring in the given sea parts. The most polluted by post-Chernobyl 9 0Sr areas were bottom sediments of Dnieper, Dniester and Danube River deltas, territory of an arrangement of a main channel of the North-Crimea Channel - region of a peninsula Tarkhankut, southeast part of Crimea (Feodosiya area). The similar situation in confined of the greatest contents 9 0Sr to the specified areas not only is kept with time (till 2000), but the process of increase of 9 0Sr concentration in bottom sediments of the investigated regions is observed. So average concentration of 9 0Sr in Dnieper River delta bottom sediments in 1987 was 28,5 Bq kg - 1 , in 2000 - 148,2 28,5 Bq kg - 1 of Dry Weight. Such character of 9 0Sr redistribution shows, that both in first years after Chernobyl NPP accident, and in the following time, the entry of 9 0Sr in the Black Sea basin occurs, basically, with water flow of the large rivers in a northwest part of the Black Sea, discharge waters of the North-Crimean Channel. These sources of 9 0Sr input to the Black Sea ecosystem considerably prevailed above direct atmospheric pollution by given radionuclide in April-May 1986 at once after the Chernobyl NPP accident. On the base of monitoring researches results the maps of 9 0Sr dynamics redistribution in the Black Sea bottom sediments (0-5 cm) since 1986 (Chernobyl NPP accident) up to 2000 were sketched out. The distribution of 9 0Sr radionuclide in the bottom sediments columns, which were selected from the Corukh river mouth region and from the Dnieper-Bug estuary area, is investigated. The peaks of 9 0Sr increased contents were founded in the profile of its vertical distribution in the bottom sediments. These peaks correspond to the periods of 9 0Sr

  10. Metal distribution characteristic of MSWI bottom ash in view of metal recovery.

    Science.gov (United States)

    Xia, Yi; He, Pinjing; Shao, Liming; Zhang, Hua

    2017-02-01

    Bottom ash is the major by-product of municipal solid waste incineration (MSWI), and is often reused as an engineering material, such as road-base aggregate. However, some metals (especially aluminum) in bottom ash can react with water and generate gas that could cause expansion and failure of products containing the ash; these metals must be removed before the ash is utilized. The size distribution and the chemical speciation of metals in the bottom ash from two Chinese MSWI plants were examined in this study, and the recovery potential of metals from the ash was evaluated. The metal concentrations in these bottom ashes were lower than that generated in other developed countries. Specifically, the contents of Al, Fe, Cu and Zn were 18.9-29.2, 25.5-32.3, 0.7-1.0 and 1.6-2.5g/kg, respectively. Moreover, 44.9-57.0wt.% of Al and 55.6-75.4wt.% of Fe were distributed in bottom ash particles smaller than 5mm. Similarly, 46.6-79.7wt.% of Cu and 42.9-74.2wt.% of Zn were concentrated in particles smaller than 3mm. The Fe in the bottom ash mainly existed as hematite, and its chemical speciation was considered to limit the recovery efficiency of magnetic separation. Copyright © 2016. Published by Elsevier B.V.

  11. Understanding the chemical and mineralogical properties of the inorganic portion of MSWI bottom ash.

    Science.gov (United States)

    Bayuseno, A P; Schmahl, W W

    2010-01-01

    This paper investigates the changes of mineralogical composition of bottom ash in the environment. The chemical and mineralogical bulk composition was determined by X-ray fluorescence (XRF) and X-ray powder diffraction (XRPD) Rietveld method. Single bottom ash particles were investigated by optical microscopy, scanning electron microscopy with quantitative energy-dispersive X-ray microanalysis (SEM/EDX) and electron probe micro analysis (EPMA). SEM/EDX and EPMA are valuable complement to bulk analysis and provide means for rapid and sensitive multi-elemental analysis of ash particles. The fresh bottom ash consists of amorphous (>30 wt.%) and major crystalline phases (>1 wt.%) such as silicates, oxides and carbonates. The mineral assemblage of the fresh bottom ash is clearly unstable and an aging process occurs by reaction towards an equilibrium mineral phase composition in the environmental conditions. The significant decrease of anhydrite and amorphous contents was observed in the aged bottom ash, leading to the formation of ettringite, hydrocalumite and rosenhahnite under atmospheric conditions. In the water-treated sample, the calcite contents increased significantly, but ettringite was altered by the dissolution and precipitation processes in part, to produce gypsum, while the remaining part reacted with chloride to form hydrocalumite. Gypsum and other Ca based minerals may take up substantial amounts of heavy metals and subsequently control leaching behaviour of bottom ash. 2010 Elsevier Ltd. All rights reserved.

  12. Stable isotope evidence for the Bottom Convective Layer homogeneity in the Black Sea.

    Science.gov (United States)

    Dubinin, Alexander V; Dubinina, Elena O; Demidova, Tatyana P; Kokryatskaya, Nataliya M; Rimskaya-Korsakova, Maria N; Kosova, Sofia A; Yakushev, Evgeniy V

    2014-01-01

    The Black Sea is the largest euxinic basin on the Earth. The anoxic zone consists of the upper part water mass stratified by density, and the lower water mass homogenized relative to density (depth >1750 m), named the Bottom Convective Layer. To assess homogeneity and possible exchange of matter across the upper and lower boundaries of the Bottom Convective Layer, new data on stable isotope composition of S, O and H were obtained. Samples were collected in August 2008 and March 2009 from two stations located in the eastern central part of the Black Sea. Distribution of δ(18)O and δD values of water for the entire water column did not vary seasonally. Appreciable differences were marked for δD value variation in the picnocline area (water depth 200-400 m) and in the BCL 5 m above the bottom that might be caused by penetration of intrusions with elevated portion of shelf modified Mediterranean Water. Observed linear relationship between δ(18)O (or δD) and salinity indicates that mixing water and salt occurs at the same time, and the deep water of the Black Sea has two end members: the high-salinity Mediterranean seawater and freshwater input. In the Bottom Convective Layer, the average δ(34)S (H2S) was -40.6 ± 0.5‰ and did not vary seasonally. At the bottom (depth > 2000 m), (34)S depletion down to -41.0‰ was observed. Our δ(34)S (SO4) data are by 2-3‰ higher than those measured previously for the Bottom Convective Layer. Sulfate from the aerobic zone with δ(34)S (SO4) = +21‰ corresponds to ocean water sulfate and that has not been subjected to sulfate reduction. Average δ(34)S (SO4) values for depths > 1250 m were found to be +23.0 ± 0.2‰ (1σ). Sulfur isotope composition of sulfate does not change in the Bottom Convective Layer and on its upper and lower boundaries, and does not depend on the season of observation.

  13. Strong Electroweak Symmetry Breaking

    CERN Document Server

    Grinstein, Benjamin

    2011-01-01

    Models of spontaneous breaking of electroweak symmetry by a strong interaction do not have fine tuning/hierarchy problem. They are conceptually elegant and use the only mechanism of spontaneous breaking of a gauge symmetry that is known to occur in nature. The simplest model, minimal technicolor with extended technicolor interactions, is appealing because one can calculate by scaling up from QCD. But it is ruled out on many counts: inappropriately low quark and lepton masses (or excessive FCNC), bad electroweak data fits, light scalar and vector states, etc. However, nature may not choose the minimal model and then we are stuck: except possibly through lattice simulations, we are unable to compute and test the models. In the LHC era it therefore makes sense to abandon specific models (of strong EW breaking) and concentrate on generic features that may indicate discovery. The Technicolor Straw Man is not a model but a parametrized search strategy inspired by a remarkable generic feature of walking technicolor,...

  14. Post-training N-methyl-D-aspartate receptor blockade offers protection from retrograde interference but does not affect consolidation of weak or strong memory traces in the water maze.

    Science.gov (United States)

    Day, M; Langston, R F

    2006-01-01

    Memory consolidation is the process where labile memory traces become long-lasting, stable memories. Previous work has demonstrated that spatial memory consolidation, several days after training in a water maze had ceased, can be disrupted by a temporary intra hippocampal infusion of the alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid/kainate antagonist LY326325 (Riedel et al., 1999). Such reversible pharmacological techniques offer advantages over the permanent lesion studies that had first suggested a role for the hippocampus in memory consolidation. However, to date the role of N-methyl-D-aspartate receptors in such systems level processes remains controversial with evidence for impairments and augmentation of performance. Here we investigate the role of post-training hippocampal N-methyl-D-aspartate receptor blockade in rats and mice on the consolidation of weak and strong memory traces using an Atlantis water maze protocol. A hidden Atlantis platform was employed and rats (experiments 1 and 2) and mice (experiment 3) were required to dwell within 20 cm of the trained location to activate and subsequently reveal the escape platform. In experiments 1 and 3 a strong memory trace was established by training rats or mice for several days in the water maze. In experiment 2 a significantly weaker trace was instituted by reducing the training period. N-methyl-D-aspartate receptor blockade was induced after the last training trial and continued for seven days. Reliable memory for the trained platform location in a retention test 15 days after the last training day demonstrated that N-methyl-D-aspartate receptor blockade did not affect memory consolidation in rats or mice. Our results also show that post-training N-methyl-D-aspartate receptor blockade can lead to better performance in further retention tests conducted after the consolidation and drug administration period. Those data suggest that specific post-training N-methyl-D-aspartate receptor blockade

  15. Stabilization of bottom sediments from Rzeszowski Reservoir

    Directory of Open Access Journals (Sweden)

    Koś Karolina

    2015-06-01

    Full Text Available The paper presents results of stabilization of bottom sediments from Rzeszowski Reservoir. Based on the geotechnical characteristics of the tested sediments it was stated they do not fulfill all the criteria set for soils in earth embankments. Therefore, an attempt to improve their parameters was made by using two additives – cement and lime. An unconfined compressive strength, shear strength, bearing ratio and pH reaction were determined on samples after different time of curing. Based on the carried out tests it was stated that the obtained values of unconfined compressive strength of sediments stabilized with cement were relatively low and they did not fulfill the requirements set by the Polish standard, which concerns materials in road engineering. In case of lime stabilization it was stated that the tested sediments with 6% addition of the additive can be used for the bottom layers of the improved road base.

  16. Plasmons in strong superconductors

    International Nuclear Information System (INIS)

    Baldo, M.; Ducoin, C.

    2011-01-01

    We present a study of the possible plasmon excitations that can occur in systems where strong superconductivity is present. In these systems the plasmon energy is comparable to or smaller than the pairing gap. As a prototype of these systems we consider the proton component of Neutron Star matter just below the crust when electron screening is not taken into account. For the realistic case we consider in detail the different aspects of the elementary excitations when the proton, electron components are considered within the Random-Phase Approximation generalized to the superfluid case, while the influence of the neutron component is considered only at qualitative level. Electron screening plays a major role in modifying the proton spectrum and spectral function. At the same time the electron plasmon is strongly modified and damped by the indirect coupling with the superfluid proton component, even at moderately low values of the gap. The excitation spectrum shows the interplay of the different components and their relevance for each excitation modes. The results are relevant for neutrino physics and thermodynamical processes in neutron stars. If electron screening is neglected, the spectral properties of the proton component show some resemblance with the physical situation in high-T c superconductors, and we briefly discuss similarities and differences in this connection. In a general prospect, the results of the study emphasize the role of Coulomb interaction in strong superconductors.

  17. Microbial diversity from chlorophyll maximum, oxygen minimum and bottom zones in the southwestern Atlantic Ocean

    Science.gov (United States)

    Medina-Silva, Renata; de Oliveira, Rafael R.; Pivel, Maria A. G.; Borges, Luiz G. A.; Simão, Taiz L. L.; Pereira, Leandro M.; Trindade, Fernanda J.; Augustin, Adolpho H.; Valdez, Fernanda P.; Eizirik, Eduardo; Utz, Laura R. P.; Groposo, Claudia; Miller, Dennis J.; Viana, Adriano R.; Ketzer, João M. M.; Giongo, Adriana

    2018-02-01

    Conspicuous physicochemical vertical stratification in the deep sea is one of the main forces driving microbial diversity in the oceans. Oxygen and sunlight availability are key factors promoting microbial diversity throughout the water column. Ocean currents also play a major role in the physicochemical stratification, carrying oxygen down to deeper zones as well as moving deeper water masses up towards shallower depths. Water samples within a 50-km radius in a pockmark location of the southwestern Atlantic Ocean were collected and the prokaryotic communities from different water depths - chlorophyll maximum, oxygen minimum and deep-sea bottom (down to 1355 m) - were described. At phylum level, Proteobacteria were the most frequent in all water depths, Cyanobacteria were statistically more frequent in chlorophyll maximum zone, while Thaumarchaeota were significantly more abundant in both oxygen minimum and bottom waters. The most frequent microorganism in the chlorophyll maximum and oxygen minimum zones was a Pelagibacteraceae operational taxonomic unit (OTU). At the bottom, the most abundant genus was the archaeon Nitrosopumilus. Beta diversity analysis of the 16S rRNA gene sequencing data uncovered in this study shows high spatial heterogeneity among water zones communities. Our data brings important contribution for the characterisation of oceanic microbial diversity, as it consists of the first description of prokaryotic communities occurring in different oceanic water zones in the southwestern Atlantic Ocean.

  18. The use of bottom ash for replacing fine aggregate in concrete paving blocks

    Directory of Open Access Journals (Sweden)

    Antoni

    2017-01-01

    Full Text Available Bottom ash that results from coal burning for electrical generation is still much underutilized in Indonesia and it is necessary to increase the usage of this waste. The manufacture of paving blocks using bottom ash, which is normally associated with high water absorption due to its high porosity and carbon content, was examined in this study with the aim to increase the usage of this waste material. The study was done in three phases: (1 the mixture of cement and bottom ash passing sieves of 2 and 5 mm were done with ratios of 1:3, 1:4, and 1:5; from the best proportion, fly ash was used to replace the cement material from 10–80%, and (3 samples with 30% and 50% fly ash replacement ratios were used in combination with 5 mm and 10 mm sieved bottom ash. Compressive strength, water absorption, and abrasion resistance tests were conducted to assess the properties of the resultant paving block. From the result, bottom ash is used to replace natural sand in making paving blocks. By optimizing the particle packing density and using fly ash as a cement replacement, the compressive strength of paving blocks can exceed 40 MPa.

  19. Fresh Properties and Flexural Strength of Self-Compacting Concrete Integrating Coal Bottom Ash

    Directory of Open Access Journals (Sweden)

    Jamaluddin Norwati

    2016-01-01

    Full Text Available This paper presents the effect of using coal bottom ash as a partial replacement of fine aggregates in self-compacting concrete (SCC on its fresh properties and flexural strength. A comparison between SCC with various replacements of fine aggregates with coal bottom ash showed that SCC obtained flexural strength decrease on increase of water cement ratio from 0.35 to 0.45. The natural sand was replaced with coal bottom ash up to 30% volumetrically. The fresh properties were investigated by slump flow, T500 spread time, L-box test and sieve segregation resistance in order to evaluate its self-compatibility by compared to control samples embed with natural sand. The results revealed that the flowability and passing ability of SCC mixtures are decreased with higher content of coal bottom ash replacement. The results also showed that the flexural strength is affected by the presence of coal bottom ash in the concrete. In addition, the water cement ratios are influence significantly with higher binder content in concrete.

  20. Landlabs: An Integrated Approach to Creating Agricultural Enterprises that Meet the Triple Bottom Line

    Science.gov (United States)

    Jordan, Nicholas; Schulte, Lisa A.; Williams, Carol; Mulla, David; Pitt, David; Slotterback, Carissa Schively; Jackson, Randall; Landis, Douglas; Dale, Bruce; Becker, Dennis; Rickenbach, Mark; Helmers, Matt; Bringi, Bobby

    2013-01-01

    Global demand is increasing for food, feed, and fiber; for additional agricultural outputs, such as biofuels; and for ecosystem services, such as clean water and outdoor recreation. In response, new agricultural enterprises are needed that produce more outputs from existing lands while meeting the "triple bottom line" of high performance…

  1. pressure distribution in a layered reservoir with gas-cap and bottom

    African Journals Online (AJOL)

    2012-07-02

    Jul 2, 2012 ... pressure derivatives, interlayer cross flow, heterogeneity, reservoir characterization, pressure distribution, dimensionless pressure. 1. Introduction. Oil production from a layered reservoir with a top gas cap and bottom water acting simultaneously poses serious challenges of rate and pressure monitoring.

  2. Dielectric properties of MSWI bottom ash for non-invasive monitoring of moisture.

    Science.gov (United States)

    Ilyas, Aamir; Persson, Magnus; van Praagh, Martijn

    2013-08-01

    The dielectric procperties of MSWI bottom ash as a function of volumetric water content (VWC) are reported in this paper. The objective was to aid the development of microwave based non-invasive emission monitoring and control system for various bottom ash applications. The dielectric measurements were made, on a 1.5-year-old bottom ash, with an electrical network analyzer in microwave range (300 MHz-1.5 GHz). The VWC of the samples ranged between 0.05 and 0.40 m(3) m(-3). The relationship between the dielectric permittivity and the VWC was modeled with an empirical model and a physically based Birchak model (BM). The results showed that a linear relationship existed between the permittivity and the VWC at higher water contents (>0.25 m(3) m(-3)). However, at lower water contents (bottom ash. The permittivity measurement, with the current method, was not affected by high salt concentrations (10 and 20 dS/m). The empirical model, as compared to BM, provided the best fit between the actual and the predicted water content. The root mean square error (RMSE) values were 0.008-0.010 and 0.06-0.09 m(3) m(-3) for the empirical and the Birchak model, respectively.

  3. A dataset from bottom trawl survey around Taiwan

    Directory of Open Access Journals (Sweden)

    Kwang-tsao Shao

    2012-05-01

    Full Text Available Bottom trawl fishery is one of the most important coastal fisheries in Taiwan both in production and economic values. However, its annual production started to decline due to overfishing since the 1980s. Its bycatch problem also damages the fishery resource seriously. Thus, the government banned the bottom fishery within 3 nautical miles along the shoreline in 1989. To evaluate the effectiveness of this policy, a four year survey was conducted from 2000–2003, in the waters around Taiwan and Penghu (Pescadore Islands, one region each year respectively. All fish specimens collected from trawling were brought back to lab for identification, individual number count and body weight measurement. These raw data have been integrated and established in Taiwan Fish Database (http://fishdb.sinica.edu.tw. They have also been published through TaiBIF (http://taibif.tw, FishBase and GBIF (website see below. This dataset contains 631 fish species and 3,529 records, making it the most complete demersal fish fauna and their temporal and spatial distributional data on the soft marine habitat in Taiwan.

  4. Strong-coupling approximations

    International Nuclear Information System (INIS)

    Abbott, R.B.

    1984-03-01

    Standard path-integral techniques such as instanton calculations give good answers for weak-coupling problems, but become unreliable for strong-coupling. Here we consider a method of replacing the original potential by a suitably chosen harmonic oscillator potential. Physically this is motivated by the fact that potential barriers below the level of the ground-state energy of a quantum-mechanical system have little effect. Numerically, results are good, both for quantum-mechanical problems and for massive phi 4 field theory in 1 + 1 dimensions. 9 references, 6 figures

  5. Strong interaction and QFD

    International Nuclear Information System (INIS)

    Ebata, T.

    1981-01-01

    With an assumed weak multiplet structure for bosonic hadrons, which is consistent with the ΔI = 1/2 rule, it is shown that the strong interaction effective hamiltonian is compatible with the weak SU(2) x U(1) gauge transformation. Especially the rho-meson transforms as a triplet under SU(2)sub(w), and this is the origin of the rho-photon analogy. It is also shown that the existence of the non-vanishing Cabibbo angle is a necessary condition for the absence of the exotic hadrons. (orig.)

  6. Bottom Trawl Survey Protocol Development (HB0706, EK60)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Cruise objectives include: 1) Investigate performance characteristics of new research bottom trawl; 2) Develop standard operating procedures for the NEFSC Bottom...

  7. MIC damage in a water coolant header for remote process equipment

    International Nuclear Information System (INIS)

    Jenkins, C.F.

    1994-01-01

    Stainless steel water piping used to supply coolant for remote chemical separations equipment developed leaks during low flow conditions resulting from an extended interruption of operations. All the leaks occurred at welds in the bottom zone of the pipe, which was blanketed with silt deposits from the unfiltered well water used for cooling. Ultrasonic, radiographic, and metallographic examinations of leak sites revealed worm hole pitting adjacent to the welds. Seepage at the penetrations was strongly acidic and resulted in corrosion on the external pipe surfaces beneath brown crusty deposits which had developed. Analyses of the water and deposits suggest a strong propensity toward microbiologically influenced corrosion (MIC) and fouling

  8. Hyperspectral Imaging for Bottom Type Classification and Water Depth Determination

    National Research Council Canada - National Science Library

    Wilson, Nikole

    2000-01-01

    .... This research proposes to apply Philpot's principal components algorithm for bathymetric mapping to a MISI hyperspectral image, whereas previously this approach has been used on synthetic data...

  9. Strong Coupling Holography

    CERN Document Server

    Dvali, Gia

    2009-01-01

    We show that whenever a 4-dimensional theory with N particle species emerges as a consistent low energy description of a 3-brane embedded in an asymptotically-flat (4+d)-dimensional space, the holographic scale of high-dimensional gravity sets the strong coupling scale of the 4D theory. This connection persists in the limit in which gravity can be consistently decoupled. We demonstrate this effect for orbifold planes, as well as for the solitonic branes and string theoretic D-branes. In all cases the emergence of a 4D strong coupling scale from bulk holography is a persistent phenomenon. The effect turns out to be insensitive even to such extreme deformations of the brane action that seemingly shield 4D theory from the bulk gravity effects. A well understood example of such deformation is given by large 4D Einstein term in the 3-brane action, which is known to suppress the strength of 5D gravity at short distances and change the 5D Newton's law into the four-dimensional one. Nevertheless, we observe that the ...

  10. Probing magnetic bottom and crustal temperature variations along the Red Sea margin of Egypt

    Science.gov (United States)

    Ravat, D.; Salem, A.; Abdelaziz, A.M.S.; Elawadi, E.; Morgan, P.

    2011-01-01

    Over 50 magnetic bottom depths derived from spectra of magnetic anomalies in Eastern Egypt along the Red Sea margin show variable magnetic bottoms ranging from 10 to 34. km. The deep magnetic bottoms correspond more closely to the Moho depth in the region, and not the depth of 580??C, which lies significantly deeper on the steady state geotherms. These results support the idea of Wasilewski and coworkers that the Moho is a magnetic boundary in continental regions. Reduced-to-pole magnetic highs correspond to areas of Younger Granites that were emplaced toward the end of the Precambrian. Other crystalline Precambrian units formed earlier during the closure of ocean basins are not strongly magnetic. In the north, magnetic bottoms are shallow (10-15. km) in regions with a high proportion of these Younger Granites. In the south, the shoaling of the magnetic bottom associated with the Younger Granites appears to be restricted to the Aswan and Ras Banas regions. Complexity in the variation of magnetic bottom depths may arise due to a combination of factors: i) regions of Younger (Precambrian) Granites with high magnetite content in the upper crust, leaving behind low Curie temperature titanomagnetite components in the middle and lower crust, ii) rise in the depth of 580??C isotherm where the crust may have been heated due to initiation of intense magmatism at the time of the Red Sea rifting (~. 20. Ma), and iii) the contrast of the above two factors with respect to the neighboring regions where the Moho and/or Curie temperature truncates lithospheric ferromagnetism. Estimates of fractal and centroid magnetic bottoms in the oceanic regions of the Red Sea are significantly below the Moho in places suggesting that oceanic uppermost mantle may be serpentinized to the depth of 15-30 km in those regions. ?? 2011 Elsevier B.V.

  11. Improving ambient noise cross-correlations in the noisy ocean bottom environment of the Juan de Fuca plate

    Science.gov (United States)

    Tian, Ye; Ritzwoller, Michael H.

    2017-09-01

    Ambient noise tomography exploits seismic ground motions that propagate coherently over long interstation distances. Such ground motions provide information about the medium of propagation that is recoverable from interstation cross-correlations. Local noise sources, which are particularly strong in ocean bottom environments, corrupt ambient noise cross-correlations and compromise the effectiveness of ambient noise tomography. Based on 62 ocean bottom seismometers (OBSs) located on Juan de Fuca (JdF) plate from the Cascadia Initiative experiment and 40 continental stations near the coast of the western United States obtained in 2011 and 2012, we attempt to reduce the effects of local noise on vertical component seismic records across the plate and onto US continent. The goal is to provide better interstation cross-correlations for use in ambient noise tomography and the study of ambient noise directionality. As shown in previous studies, tilt and compliance noise are major sources of noise that contaminate the vertical channels of the OBSs and such noise can be greatly reduced by exploiting information on the horizontal components and the differential pressure gauge records, respectively. We find that ambient noise cross-correlations involving OBSs are of significantly higher signal-to-noise ratio at periods greater than 10 s after reducing these types of noise, particularly in shallow water environments where tilt and compliance noise are especially strong. The reduction of tilt and compliance noise promises to improve the accuracy and spatial extent of ambient noise tomography, allowing measurements based on coherently propagating ambient noise to be made at stations in the shallower parts of the JdF plate and at longer periods than in previous studies. In addition such local noise reduction produces better estimates of the azimuthal content of ambient noise.

  12. Bottom-up grammar analysis : a functional formulation

    NARCIS (Netherlands)

    Jeuring, J.T.; Swierstra, D.

    1994-01-01

    This paper discusses bottom-up grammar analysis problems such as te EMPTY problem and the FIRST problem. It defines a general class of bottom-up grammar analysis problems, and from this definition it derives a functional program for performing bottom-up grammar analysis. The derivation is purely

  13. 49 CFR 179.100-14 - Bottom outlets.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Bottom outlets. 179.100-14 Section 179.100-14... Specifications for Pressure Tank Car Tanks (Classes DOT-105, 109, 112, 114 and 120) § 179.100-14 Bottom outlets. (a) Bottom outlets for discharge of lading is prohibited, except as provided in § 179.103-3. If...

  14. 49 CFR 179.103-5 - Bottom outlets.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Bottom outlets. 179.103-5 Section 179.103-5... Specifications for Pressure Tank Car Tanks (Classes DOT-105, 109, 112, 114 and 120) § 179.103-5 Bottom outlets... devices as prescribed in § 179.103-3, tanks may be equipped with approved bottom outlet valves. If applied...

  15. LIGO: The strong belief

    CERN Multimedia

    Antonella Del Rosso

    2016-01-01

    Twenty years of designing, building and testing a number of innovative technologies, with the strong belief that the endeavour would lead to a historic breakthrough. The Bulletin publishes an abstract of the Courier’s interview with Barry Barish, one of the founding fathers of LIGO.   The plots show the signals of gravitational waves detected by the twin LIGO observatories at Livingston, Louisiana, and Hanford, Washington. (Image: Caltech/MIT/LIGO Lab) On 11 February, the Laser Interferometer Gravitational-Wave Observatory (LIGO) and Virgo collaborations published a historic paper in which they showed a gravitational signal emitted by the merger of two black holes. These results come after 20 years of hard work by a large collaboration of scientists operating the two LIGO observatories in the US. Barry Barish, Linde Professor of Physics, Emeritus at the California Institute of Technology and former Director of the Global Design Effort for the Internat...

  16. Control Properties of Bottom Fired Marine Boilers

    DEFF Research Database (Denmark)

    Solberg, Brian; Andersen, Palle; Karstensen, Claus M. S.

    2005-01-01

    This paper focuses on model analysis of a dynamic model of a bottom fired one-pass smoke tube boiler. Linearised versions of the model are analysed to determine how gain, time constants and right half plane zeros (caused by the shrink-and-swell phenomenon) depend on the steam flow load. Furthermore...... the interactions in the system are inspected to analyse potential benefit from using a multivariable control strategy in favour of the current strategy based on single loop theory. An analysis of the nonlinear model is carried out to further determine the nonlinear characteristics of the boiler system...

  17. Bottom loaded filter for radioactive liquids

    International Nuclear Information System (INIS)

    Wendland, W.G.

    1983-01-01

    This invention relates to equipment for filtering liquids and more particularly to filter assemblies for use with radioactive by-products of nuclear power plants. The invention provides a compact, bottom-loaded filter assembly that can be quickly and safely loaded and unloaded without the use of complex remote equipment. The assembly is integrally shielded and does not require external shielding. The closure hatch may be automatically aligned to facilitate quick sealing attachment after replacement of the filter cartridge, and the filter cartridge may be automatically positioned within the filter housing during the replacement operation

  18. A new kind of bottom quark factory

    International Nuclear Information System (INIS)

    Mtingwa, S.K.; Strikman, M.; AN SSSR, Leningrad

    1991-01-01

    We describe a novel method of producing large numbers of B mesons containing bottom quarks. It is known that one should analyze at least 10 9 B meson decays to elucidate the physics of CP violation and rare B decay modes. Using the ultra high energy electron beams from the future generation of electron linear colliders, we Compton backscatter low energy laser beams off these electron beams. From this process, we produce hot photons having energy hundreds of GeV. Upon scattering these hot photons onto stationary targets, we show that it is possible to photoproduce and measure the necessary 10 9 B mesons per year. 24 refs., 4 figs

  19. Top (and Bottom) asymmetries at the LHC

    CERN Document Server

    Pinamonti, Michele; The ATLAS collaboration

    2015-01-01

    The latest top pair production charge asymmetry measurements by the ATLAS and CMS Collaborations are presented: inclusive and differential measurements in the single lepton and dilepton channels based on the full 7 TeV data-set, a combination of the 7 TeV single lepton measurements by the two experiments, and a measurement in the single lepton channel on the full 8 TeV data-set performed by the CMS experiment. The first measurement of the bottom pair producion charge asymmetry by the LHCb experiment is also mentioned.

  20. Neoliberalism Viewed From the Bottom Up

    DEFF Research Database (Denmark)

    Danneris, Sophie

    2017-01-01

    Drawing on the assumption that it is pivotal to include a bottom up perspective to understand the way in which the welfare system functions, this chapter sets out to explore the lived experience of neoliberalism. The purpose is to gain insight into the consequences of neoliberalism from...... the viewpoint of the vulnerable benefit claimants who encounter it on a daily basis. The analysis is based on a qualitative longitudinal study conducted from 2013 to 2015, which shows how, in varying ways, clients routinely cope with being part of a neoliberal welfare state: by resignation, by taking action...

  1. PREFACE: Strongly correlated electron systems Strongly correlated electron systems

    Science.gov (United States)

    Saxena, Siddharth S.; Littlewood, P. B.

    2012-07-01

    This special section is dedicated to the Strongly Correlated Electron Systems Conference (SCES) 2011, which was held from 29 August-3 September 2011, in Cambridge, UK. SCES'2011 is dedicated to 100 years of superconductivity and covers a range of topics in the area of strongly correlated systems. The correlated electronic and magnetic materials featured include f-electron based heavy fermion intermetallics and d-electron based transition metal compounds. The selected papers derived from invited presentations seek to deepen our understanding of the rich physical phenomena that arise from correlation effects. The focus is on quantum phase transitions, non-Fermi liquid phenomena, quantum magnetism, unconventional superconductivity and metal-insulator transitions. Both experimental and theoretical work is presented. Based on fundamental advances in the understanding of electronic materials, much of 20th century materials physics was driven by miniaturisation and integration in the electronics industry to the current generation of nanometre scale devices. The achievements of this industry have brought unprecedented advances to society and well-being, and no doubt there is much further to go—note that this progress is founded on investments and studies in the fundamentals of condensed matter physics from more than 50 years ago. Nevertheless, the defining challenges for the 21st century will lie in the discovery in science, and deployment through engineering, of technologies that can deliver the scale needed to have an impact on the sustainability agenda. Thus the big developments in nanotechnology may lie not in the pursuit of yet smaller transistors, but in the design of new structures that can revolutionise the performance of solar cells, batteries, fuel cells, light-weight structural materials, refrigeration, water purification, etc. The science presented in the papers of this special section also highlights the underlying interest in energy-dense materials, which

  2. Characterization of a stratigraphically constrained gas hydrate system along the western continental margin of Svalbard from ocean bottom seismometer data

    OpenAIRE

    Chabert, Anne; Minshull, Tim A.; Westbrook, Graham K.; Berndt, Christian; Thatcher, Kate E.; Sarkar, Sudipta

    2011-01-01

    The ongoing warming of bottom water in the Arctic region is anticipated to destabilize some of the gas hydrate present in shallow seafloor sediment, potentially causing the release of methane from dissociating hydrate into the ocean and the atmosphere. Ocean-bottom seismometer (OBS) experiments were conducted along the continental margin of western Svalbard to quantify the amount of methane present as hydrate or gas beneath the seabed. P- and S-wave velocities were modeled for five sites alon...

  3. Experimental determination of bottom relief on the basis of studies of the lower part of the river Samara

    OpenAIRE

    Dubovyk, Denys; Borokhovych, Yulii

    2017-01-01

    Experimentally determine the bottom relief on the basis of studies of the lower section of the river. Samara. To build a route for measuring depths and digitizing depths, we used the built-in Android application, Androzik. Along with measurements of depths, water turbidity and sedimentation rate were determined. About 2,000 depth points were obtained, the data was transferred to the GIS platform, resulting in a bottom relief model, the area and volume of the reservoir. Laboratory tests of wat...

  4. NLO QCD corrections to top anti-top bottom anti-bottom production at the LHC

    CERN Document Server

    Bredenstein, Axel; Dittmaier, Stefan; Pozzorini, Stefano

    2010-01-01

    The next-to-leading order (NLO) QCD corrections to top anti-top bottom anti-bottom (tTbB) production at the LHC reveal that the scale choice adopted in previous lowest-order simulations underestimates the tTbB cross section by a factor two. We discuss a new dynamical scale that stabilizes the perturbative predictions and describe the impact of the corrections on the shape of distributions. We also account for the techniques employed to compute the six-particle one-loop amplitudes with high CPU efficiency.

  5. Investigation on Leaching Behaviour of Fly Ash and Bottom Ash Replacement in Self-Compacting Concrete

    Science.gov (United States)

    Kadir, Aeslina Abdul; Ikhmal Haqeem Hassan, Mohd; Bakri Abdullah, Mohd Mustafa Al

    2016-06-01

    Fly ash and bottom ash are some of the waste generated by coal-fired power plants, which contains large quantities of toxic and heavy metals. In recent years, many researchers have been interested in studying on the properties of self-compacting concrete incorporated with fly ash and bottom ash but there was very limited research from the combination of fly ash and bottom ash towards the environmental needs. Therefore, this research was focused on investigating the leachability of heavy metals of SCC incorporated with fly ash and bottom ash by using Toxicity Characteristic Leaching Procedure, Synthetic Precipitation Leaching Procedure and Static Leaching Test. The samples obtained from the coal-fired power plant located at Peninsula, Malaysia. In this study, the potential heavy metals leached out from SCC that is produced with fly ash as a replacement for Ordinary Portland Cement and bottom ash as a substitute for sand with the ratios from 10% to 30% respectively were designated and cast. There are eight heavy metals of concern such as As, Cr, Pb, Zn, Cu, Ni, Mn and Fe. The results indicated that most of the heavy metals leached below the permissible limits from the United States Environmental Protection Agency and World Health Organization limit for drinking water. As a conclusion, the minimum leaching of the heavy metals from the incorporation of fly ash and bottom ash in self-compacting concrete was found in 20% of fly ash and 20% of bottom ash replacement. The results also indicate that this incorporation could minimize the potential of environmental problems.

  6. An Improved Heat Budget Estimation Including Bottom Effects for General Ocean Circulation Models

    Science.gov (United States)

    Carder, Kendall; Warrior, Hari; Otis, Daniel; Chen, R. F.

    2001-01-01

    This paper studies the effects of the underwater light field on heat-budget calculations of general ocean circulation models for shallow waters. The presence of a bottom significantly alters the estimated heat budget in shallow waters, which affects the corresponding thermal stratification and hence modifies the circulation. Based on the data collected during the COBOP field experiment near the Bahamas, we have used a one-dimensional turbulence closure model to show the influence of the bottom reflection and absorption on the sea surface temperature field. The water depth has an almost one-to-one correlation with the temperature rise. Effects of varying the bottom albedo by replacing the sea grass bed with a coral sand bottom, also has an appreciable effect on the heat budget of the shallow regions. We believe that the differences in the heat budget for the shallow areas will have an influence on the local circulation processes and especially on the evaporative and long-wave heat losses for these areas. The ultimate effects on humidity and cloudiness of the region are expected to be significant as well.

  7. Fresh Bottom Ash Characteristics Dependence on Fractional Composition

    OpenAIRE

    Jurgita Seniūnaitė; Saulius Vasarevičius

    2017-01-01

    Waste incineration process generates two main by-products streams: fly ash and bottom ash. Bottom ash is composed of a variety of oxides, heavy metals and salts. Chemical materials distributed unevenly in different fractions of bottom ash. This study investigates the heavy metals (Pb, Cd) content dependence of bottom ash and fraction composition. Studies were performed with five different fractions (0–2 mm; 2–5.6 mm; 5.6–11.2 mm; 11.2–22,4 mm; 22.4–40 mm) of fresh bottom ash. After a one-step...

  8. Feasibility Of Making Concrete Using Lignite Coal Bottom Ash As Fine Aggregate

    Directory of Open Access Journals (Sweden)

    Thandavamoorthy T. S.

    2015-09-01

    Full Text Available Concrete is generally produced using materials such as crushed stone and river sand to the extent of about 80-90% combined with cement and water. These materials are quarried from natural sources. Their depletion will cause strain on the environment. To prevent this, bottom ash produced at thermal power plants by burning of coal has been utilized in this investigation into making concrete. The experimental investigation presents the development of concrete containing lignite coal bottom ash as fine aggregate in various percentages of 25, 50, and 100. Compressive, split tensile, and flexural strength as part of mechanical properties; acid, sulphate attack, and sustainability under elevated temperature as part of durability properties, were determined. These properties were compared with that of normal concrete. It was concluded from this investigation that bottom ash to an extent of 25% can be substituted in place of river sand in the production of concrete.

  9. <strong>Relative Biological Effect of Antiprotonsstrong>> strong>

    DEFF Research Database (Denmark)

    Bassler, Niels; Holzscheiter, Michael

    purpose/objective The AD-4/ACE collaboration has recently performed experiments to directly measure the RBE of antiprotons. Antiprotons have very similar stopping power compared to protons, but when they come to rest, antiprotons will annihilate on a target nucleus and thereby release almost 2 Ge......V of energy. About 30 MeV of this energy is deposited in the vicinity of the Bragg-peak, thereby significantly enhancing it. It is furthermore expected that this additional energy is deposited by radiation which carries a high-LET component. This will have a significant influence on the radiobiological...... nuclear research facility CERN. A beam of 126 MeV antiprotons, corresponding to about 12 cm range in water, was spread out to a SOBP with a width of 1 cm. Dosimetry experiments were carried out with ionization chambers, alanine pellets and radiochromic film, and the results were used for benchmarking...

  10. John Strong (1941 - 2006)

    CERN Multimedia

    Wickens, F

    Our friend and colleague John Strong was cruelly taken from us by a brain tumour on Monday 31st July, a few days before his 65th birthday John started his career working with a group from Westfield College, under the leadership of Ted Bellamy. He obtained his PhD and spent the early part of his career on experiments at Rutherford Appleton Laboratory (RAL), but after the early 1970s his research was focussed on experiments in CERN. Over the years he made a number of notable contributions to experiments in CERN: The Omega spectrometer adopted a system John had originally developed for experiments at RAL using vidicon cameras to record the sparks in the spark chambers; He contributed to the success of NA1 and NA7, where he became heavily involved in the electronic trigger systems; He was responsible for the second level trigger system for the ALEPH detector and spent five years leading a team that designed and built the system, which ran for twelve years with only minor interventions. Following ALEPH he tur...

  11. Stirring Strongly Coupled Plasma

    CERN Document Server

    Fadafan, Kazem Bitaghsir; Rajagopal, Krishna; Wiedemann, Urs Achim

    2009-01-01

    We determine the energy it takes to move a test quark along a circle of radius L with angular frequency w through the strongly coupled plasma of N=4 supersymmetric Yang-Mills (SYM) theory. We find that for most values of L and w the energy deposited by stirring the plasma in this way is governed either by the drag force acting on a test quark moving through the plasma in a straight line with speed v=Lw or by the energy radiated by a quark in circular motion in the absence of any plasma, whichever is larger. There is a continuous crossover from the drag-dominated regime to the radiation-dominated regime. In the crossover regime we find evidence for significant destructive interference between energy loss due to drag and that due to radiation as if in vacuum. The rotating quark thus serves as a model system in which the relative strength of, and interplay between, two different mechanisms of parton energy loss is accessible via a controlled classical gravity calculation. We close by speculating on the implicati...

  12. Strong-interaction nonuniversality

    International Nuclear Information System (INIS)

    Volkas, R.R.; Foot, R.; He, X.; Joshi, G.C.

    1989-01-01

    The universal QCD color theory is extended to an SU(3) 1 direct product SU(3) 2 direct product SU(3) 3 gauge theory, where quarks of the ith generation transform as triplets under SU(3)/sub i/ and singlets under the other two factors. The usual color group is then identified with the diagonal subgroup, which remains exact after symmetry breaking. The gauge bosons associated with the 16 broken generators then form two massive octets under ordinary color. The interactions between quarks and these heavy gluonlike particles are explicitly nonuniversal and thus an exploration of their physical implications allows us to shed light on the fundamental issue of strong-interaction universality. Nonuniversality and weak flavor mixing are shown to generate heavy-gluon-induced flavor-changing neutral currents. The phenomenology of these processes is studied, as they provide the major experimental constraint on the extended theory. Three symmetry-breaking scenarios are presented. The first has color breaking occurring at the weak scale, while the second and third divorce the two scales. The third model has the interesting feature of radiatively induced off-diagonal Kobayashi-Maskawa matrix elements

  13. The petroleum industry improving the bottom line

    International Nuclear Information System (INIS)

    Benner, R.I.

    1992-01-01

    The oil and gas exploration and production business environment has presented many challenges over the last decade, notably price volatility and rising costs. Managing the margin and changing a company's cost structure to improve the bottom line is a major issue with company executives. The experiences of Oryx Energy Company since its spinoff from Sun Company in 1988 are used as an example of a company makeover. A generalized exploration and production income statement is employed to present industry cost/portfolio relationships and strategies for improving the bottom line. At Oryx, three major strategies were set in place to enhance shareholder value: an increased emphasis on applied technology, including horizontal drilling, advanced 3-dimensional seismic prospecting, and intensive use of interactive computer workstations; international expansion; and an emphasis on the U.S. Gulf of Mexico, deemphasizing the onshore U.S. and the gas processing business. Specific strategies are outlined in the areas of increasing revenues, reducing production cost and exploration expense, and controlling general and administrative expenses. 8 refs., 18 figs., 2 tabs

  14. Effect of kaolin addition on the performance of controlled low-strength material using industrial waste incineration bottom ash.

    Science.gov (United States)

    Naganathan, Sivakumar; Razak, Hashim Abdul; Hamid, Siti Nadzriah Abdul

    2010-09-01

    Incineration of industrial waste produces large quantities of bottom ash which are normally sent to secured landfill, but is not a sustainable solution. Use of bottom ash in engineering applications will contribute to sustainability and generate revenue. One way of using the industrial waste incineration bottom ash is in controlled low-strength material (CLSM). Use of bottom ash in CLSM has problems related to bleeding and excessive strength development and so an additive has to be used to control bleeding and strength development. The main objective of this research is to study the effect of kaolin addition on the performance of CLSM made using industrial waste incineration bottom ash. CLSM mixes were made with bottom ash, cement, and refined kaolin. Various tests were performed on the CLSM in fresh and hardened states including compressive strength, water absorption, California bearing ratio (CBR) and the tests for concentration of leachable substances on the bleed and leachate. The compressive strength of CLSM tested ranged from 0.11 to 9.86 MPa. CBR values ranged from 6 to 46, and water absorption values from 12 to 36%. It was shown that the addition of kaolin delayed the initial setting time of CLSM mixtures, reduced bleeding, lowered the compressive strength, and increased the values of water absorption, sorption, and initial surface absorption. The CLSM tested did not have corrosivity. It was shown that the hardened CLSM was non hazardous, and the addition of kaolin increased the concentration of heavy metals and salts in the bleed and leachate.

  15. Some Applications of Holography to Study Strongly Correlated Systems

    Directory of Open Access Journals (Sweden)

    Bhatnagar Neha

    2018-01-01

    Full Text Available In this work, we study the transport coefficients of strongly coupled condensed matter systems using gauge/gravity duality (holography. We consider examples from the real world and evaluate the conductivities from their gravity duals. Adopting the bottom-up approach of holography, we obtain the frequency response of the conductivity for (1+1-dimensional systems. We also evaluate the DC conductivities for non-relativistic condensed matter systems with hyperscaling violating geometry.

  16. Effects of substrate induced respiration on the stability of bottom ash in landfill cover environment.

    Science.gov (United States)

    Ilyas, A; Lovat, E; Persson, K M

    2014-12-01

    The municipal solid waste incineration bottom ash is being increasingly used to construct landfill covers in Sweden. In post-closure, owing to increased cover infiltration, the percolating water can add external organic matter to bottom ash. The addition and subsequent degradation of this external organic matter can affect metal mobility through complexation and change in redox conditions. However, the impacts of such external organic matter addition on bottom ash stability have not been fully evaluated yet. Therefore, the objective of this study was to evaluate the impact of external organic matter on bottom ash respiration and metal leaching. The samples of weathered bottom ash were mixed with oven dried and digested wastewater sludge (1%-5% by weight). The aerobic respiration activity (AT4), as well as the leaching of metals, was tested with the help of respiration and batch leaching tests. The respiration and heavy metal leaching increased linearly with the external organic matter addition. Based on the results, it was concluded that the external organic matter addition would negatively affect the quality of landfill cover drainage. © The Author(s) 2014.

  17. Copper speciation in municipal solid waste incinerator bottom ash leachates; Kopparformer i lakvatten fraan energiaskor

    Energy Technology Data Exchange (ETDEWEB)

    Olsson, Susanna; Gustafsson, Jon Petter [Royal Inst. of Tech., Stockholm (Sweden); Schaik, Joris van; Berggren Kleja, Dan [Swedish Univ. of Agricultural Sciences, Uppsala (Sweden); Hees, Patrick van [Oerebro Univ. (Sweden)

    2006-03-15

    The formation of copper (Cu) complexes with dissolved organic carbon (DOC) in bottom ash from municipal solid waste incineration (MSWI) may increase the total amount of Cu released but at the same time reduce its toxicity. In this study, DOC in a MSWI bottom ash leachate was characterized and the Cu-binding properties of different DOC fractions in the ash leachate and in a soil solution were studied. This knowledge may be used for improved environmental assessment of MSWI bottom ash in engineering applications. The Cu{sup 2+} activity at different pH values was measured potentiometrically using a Cu-ion selective electrode (Cu-ISE). Experimental copper complexation results were compared to speciation calculations made in Visual MINTEQ with the NICA-Donnan model and the Stockholm Humic Model (SHM). The MSWI bottom ash leachate contained a larger proportion of hydrophilic organic carbon than the investigated soil solution and other natural waters. The hydrophilic fraction of both samples showed Cu{sup 2+} binding properties similar to that of the bulk, cation-exchanged, leachate. For the ash leachate, the pH dependence of the Cu activity was not correctly captured by neither the SHM nor the NICA-Donnan model, but for the soil solution the model predictions of Cu speciation were in good agreement with the obtained results. The complex formation properties of the ash DOC appears to be less pH-dependent than what is assumed for DOC in natural waters. Hence, models calibrated for natural DOC may give inconsistent simulations of Cu-DOC complexation in MSWI bottom ash leachate. A Biotic Ligand Model for Daphnia Magna was used to provide an estimate of the copper concentrations at LC50 for a simulated bottom ash leachate. It was concluded that the Cu concentrations in certain bottom ash leachates are high enough to pose an ecotoxicological risk; however, after dilution and soil sorption, the risks for neighboring water bodies are most likely negligible. Three processes were

  18. Bottom mounted seabed mooring frame for high current field

    Digital Repository Service at National Institute of Oceanography (India)

    AshokKumar, K.; Chandramohan, P.; Pednekar, P.S.; Diwan, S.G.

    and direction on the sea surface and at a fixed five layers. The company supplied frame was not suitable to use at the proposed measurement location, owing to random oscillation in the seabed, strong currents and high concentration of sediments in the water...

  19. Improved curdlan production with discarded bottom parts of Asparagus spear.

    Science.gov (United States)

    Anane, Rex Frimpong; Sun, Huifang; Zhao, Lamei; Wang, Le; Lin, Chun; Mao, Zichao

    2017-04-07

    This work evaluated the improvement of curdlan production of Agrobacterium sp. ATCC 31749 by using culture medium containing juice of discarded bottom part of green Asparagus spear (MJDA). Curdlan production was carried out using Agrobacterium sp. ATCC 31749 in flasks with different volumes of MJDA and its non-juice-adding control (CK) incubated in shaker at 30 °C, 200 rpm rotation for 168 h. All MJDA media increased Agrobacterium sp. ATCC 31749 cell mass and enhanced the cells' ability to utilise sucrose, the carbon source for curdlan biosynthesis, and thereby produced higher concentration of curdlan than CK which is used for commercial production of curdlan. After 168 h of fermentation, 10% MJDA produced 40.2 g/l of curdlan whiles CK produced 21.1 g/l. Curdlan production was increased by 90.4% higher in 10% MJDA than CK. Curdlan produced by 10% MJDA contains 1.2 and 1.5 µg/ml of Asparagus flavonoids and saponins respectively as additives which have wide range of health benefits. The mass of sucrose needed to produce 1.0 g curdlan by Agrobacterium sp. ATCC 31749 in CK is 1.7-fold more than in 10% MJDA. The results strongly revealed that 5-10% MJDA is a good curdlan fermentation media which increase curdlan production yield with cheaper cost of production and simultaneously reduce environmental waste resulting from the large scaled discarded bottom parts of green Asparagus spear during Asparagus production.

  20. Water Flow Experiments

    Indian Academy of Sciences (India)

    This is a simple exercise in elementary fluid dynamics for the undergraduate and the secondary school level. Here, we explore the flow of water through an orifice at the bottom of a cylindri- cal bottle/tank, first through a tube attached to the bottom of the bottle/tank and then without the tube. The experiment is easy to perform.

  1. Water

    Science.gov (United States)

    ... environment and your health: Green living Sun Water Health effects of water pollution How to protect yourself from water pollution Air ... can hurt your health. Learn more about the health effects of polluted water. You can also learn more ... Source: U.S. Environmental Protection Agency Here are ...

  2. Coil-springs used as mechanical filter. Modification of the bottom tie plate of a fuel assembly

    International Nuclear Information System (INIS)

    Nylund, O.

    1993-01-01

    Describes an improved design of the bottom tie plate of a fuel assembly. The improvement of the design is an arrangement of horizontal channels holding coil-springs and crossing the vertical channels for the cooling water. The coil-springs work as strainers for the cooling water

  3. Estimates of bottom roughness length and bottom shear stress in South San Francisco Bay, California

    Science.gov (United States)

    Cheng, R.T.; Ling, C.-H.; Gartner, J.W.; Wang, P.-F.

    1999-01-01

    A field investigation of the hydrodynamics and the resuspension and transport of participate matter in a bottom boundary layer was carried out in South San Francisco Bay (South Bay), California, during March-April 1995. Using broadband acoustic Doppler current profilers, detailed measurements of turbulent mean velocity distribution within 1.5 m above bed have been obtained. A global method of data analysis was used for estimating bottom roughness length zo and bottom shear stress (or friction velocities u*). Field data have been examined by dividing the time series of velocity profiles into 24-hour periods and independently analyzing the velocity profile time series by flooding and ebbing periods. The global method of solution gives consistent properties of bottom roughness length zo and bottom shear stress values (or friction velocities u*) in South Bay. Estimated mean values of zo and u* for flooding and ebbing cycles are different. The differences in mean zo and u* are shown to be caused by tidal current flood-ebb inequality, rather than the flooding or ebbing of tidal currents. The bed shear stress correlates well with a reference velocity; the slope of the correlation defines a drag coefficient. Forty-three days of field data in South Bay show two regimes of zo (and drag coefficient) as a function of a reference velocity. When the mean velocity is >25-30 cm s-1, the ln zo (and thus the drag coefficient) is inversely proportional to the reference velocity. The cause for the reduction of roughness length is hypothesized as sediment erosion due to intensifying tidal currents thereby reducing bed roughness. When the mean velocity is <25-30 cm s-1, the correlation between zo and the reference velocity is less clear. A plausible explanation of scattered values of zo under this condition may be sediment deposition. Measured sediment data were inadequate to support this hypothesis, but the proposed hypothesis warrants further field investigation.

  4. The impact of QCD plasma instabilities on bottom-up thermalization

    OpenAIRE

    Bodeker, Dietrich

    2005-01-01

    QCD plasma instabilities, caused by an anisotropic momentum distributions of the particles in the plasma, are likely to play an important role in thermalization in heavy ion collisions. We consider plasmas with two different components of particles, one strongly anisotropic and one isotropic or nearly isotropic. The isotropic component does not eliminate instabilities but it decreases their growth rates. We investigate the impact of plasma instabilities on the first stage of the ``bottom-up''...

  5. Migration of nitrate, nitrite, and ammonia through the municipal solid waste incinerator bottom ash layer in the simulated landfill.

    Science.gov (United States)

    Yao, Jun; Chen, Luxi; Zhu, Huayue; Shen, Dongsheng; Qiu, Zhanhong

    2017-04-01

    Simulated landfill was operated for 508 days to investigate the effect of municipal solid waste incinerator (MSWI) bottom ash layer on the migration of nitrate, nitrite, and ammonia when it was used as the intermediate layer in the landfill. The result suggested that the MSWI bottom ash layer could capture the nitrate, nitrite, and ammonia from the leachate. The adsorption of the nitrate, nitrite, and ammonia on the MSWI bottom ash layer was saturated at the days 396, 34, and 97, respectively. Afterwards, the nitrogen species were desorbed from the MSWI bottom ash layer. Finally, the adsorption and desorption could reach the equilibrium. The amounts of adsorbed nitrate and nitrite on the MSWI bottom ash layer were 1685.09 and 7.48 mg, respectively, and the amount of the adsorbed and transformed ammonia was 13,773.19 mg, which was much higher than the desorbed. The water leaching test and synthetic precipitation leaching procedure (SPLP) results showed that the leachable nitrate, nitrite, and ammonia in the MSWI bottom ash were greatly increased after the landfill operation, suggesting that the adsorbed nitrogen could be finally leached out. Besides, the results also showed that MSWI bottom ash layer could affect the release of nitrate and ammonia at the initial stage of the landfill. However, it had little effect on the release of nitrite.

  6. Marine bacterioplankton community turnover within seasonally hypoxic waters of a subtropical sound: Devil's Hole, Bermuda.

    Science.gov (United States)

    Parsons, Rachel J; Nelson, Craig E; Carlson, Craig A; Denman, Carmen C; Andersson, Andreas J; Kledzik, Andrew L; Vergin, Kevin L; McNally, Sean P; Treusch, Alexander H; Giovannoni, Stephen J

    2015-10-01

    Understanding bacterioplankton community dynamics in coastal hypoxic environments is relevant to global biogeochemistry because coastal hypoxia is increasing worldwide. The temporal dynamics of bacterioplankton communities were analysed throughout the illuminated water column of Devil's Hole, Bermuda during the 6-week annual transition from a strongly stratified water column with suboxic and high-pCO2 bottom waters to a fully mixed and ventilated state during 2008. A suite of culture-independent methods provided a quantitative spatiotemporal characterization of bacterioplankton community changes, including both direct counts and rRNA gene sequencing. During stratification, the surface waters were dominated by the SAR11 clade of Alphaproteobacteria and the cyanobacterium Synechococcus. In the suboxic bottom waters, cells from the order Chlorobiales prevailed, with gene sequences indicating members of the genera Chlorobium and Prosthecochloris--anoxygenic photoautotrophs that utilize sulfide as a source of electrons for photosynthesis. Transitional zones of hypoxia also exhibited elevated levels of methane- and sulfur-oxidizing bacteria relative to the overlying waters. The abundance of both Thaumarcheota and Euryarcheota were elevated in the suboxic bottom waters (> 10(9) cells l(-1)). Following convective mixing, the entire water column returned to a community typical of oxygenated waters, with Euryarcheota only averaging 5% of cells, and Chlorobiales and Thaumarcheota absent. © 2014 Society for Applied Microbiology and John Wiley & Sons Ltd.

  7. Designing the organisational chart from the bottom

    DEFF Research Database (Denmark)

    Giangreco, Antonio; Carugati, Andrea

    and control. Marco had been called in because of his reputation for being an effective innovator with unconventional ideas for the public sector. Previously, during his long career in the civil service, Marco proved to be an effective leader and negotiator who was open to other people's view points. He would...... share any significant and final decisions with his employees, rather than merely imposing his own personal choice. After spending some time in the organisation, he put into action a bottom up method to redesign the structure of the HR department. He decided to temporarily suspend the existing internal...... organisation and involve all the HR employees in its redesign, starting with a list of work related activities that they had identified. If on one hand this method was energy and time consuming, on the other, the new design would have greater chances of being adopted enthusiastically by his employees....

  8. Bottom loaded filter for radioactive liquid

    International Nuclear Information System (INIS)

    Wendland, W.G.

    1980-01-01

    A specification is given for a bottom loaded filter assembly for filtering radioactive liquids through a replaceable cartridge filter, which includes a lead-filled jacket enveloping a housing having a chamber therein for the filter cartridge. A track arrangement carries a hatch for sealing the chamber. A spacer plug supports the cartridge within guide means associated with the inlet conduit in the chamber. The plug and cartridge drop out of the chamber when the hatch is unbolted and moved laterally of the chamber along the track. During cartridge replacement a new plug and cartridge are supported in the guide means by a spacer bar inserted across the track means under the chamber. The hatch is then slid under the chamber and bolted to a flange on the housing, engaging an O-ring to seal the chamber. (author)

  9. Analysis of Peach Bottom turbine trip tests

    International Nuclear Information System (INIS)

    Cheng, H.S.; Lu, M.S.; Hsu, C.J.; Shier, W.G.; Diamond, D.J.; Levine, M.M.; Odar, F.

    1979-01-01

    Current interest in the analysis of turbine trip transients has been generated by the recent tests performed at the Peach Bottom (Unit 2) reactor. Three tests, simulating turbine trip transients, were performed at different initial power and coolant flow conditions. The data from these tests provide considerable information to aid qualification of computer codes that are currently used in BWR design analysis. The results are presented of an analysis of a turbine trip transient using the RELAP-3B and the BNL-TWIGL computer codes. Specific results are provided comparing the calculated reactor power and system pressures with the test data. Excellent agreement for all three test transients is evident from the comparisons

  10. Bringing corporate culture to the bottom line.

    Science.gov (United States)

    Denison, D R

    1984-01-01

    Up to now managers could find little evidence to support the idea that the organization's culture has an impact on its bottom-line performance. To remedy this, Denison draws on survey and performance data from 34 large corporations to show that those that have participative cultures experience better performance than those that do not. This difference in performance appears to have widened over the five years that these firms were studied. The results also hold up when the performance measures for each firm (return on investment and return on sales) are compared with those of their competitors. Denison suggests that this comparative approach to the study of organizational culture provides a way to capture the impact that culture has on organizational performance. This strategy, he argues, also provides a way of diagnosing organizations and measuring the ways in which human resources management, organizational culture, and management practices do, in fact, contribute to the success of business organizations.

  11. Control Properties of Bottom Fired Marine Boilers

    DEFF Research Database (Denmark)

    Solberg, Brian; Andersen, Palle; Karstensen, Claus M. S.

    2007-01-01

    This paper focuses on model analysis of a dynamic model of a bottom fired one-pass smoke tube boiler. Linearized versions of the model are analyzed and show large variations in system gains at steady state as function of load whereas gain variations near the desired bandwidth are small. An analysis...... of the potential benefit from using a multivariable control strategy in favor of the current strategy based on single loop theory is carried out and proves that the interactions in the system are not negligible and a subsequent controller design should take this into account. A design using dynamical decoupling...... showed substantial improvement compared to a decentralized scheme based on sequential loop closing. Similar or better result is expected to be obtainable using a full Multiple input Multiple output scheme. Furthermore closed loop simulations, applying a linear controller to the nonlinear plant model...

  12. Control Properties of Bottom Fired Marine Boilers

    DEFF Research Database (Denmark)

    Solberg, Brian; Andersen, Palle; Karstensen, Claus M. S.

    2005-01-01

    This paper focuses on model analysis of a dynamic model of a bottom fired one-pass smoke tube boiler. Linearised versions of the model are analysed to determine how gain, time constants and right half plane zeros (caused by the shrink-and-swell phenomenon) depend on the steam flow load. Furthermore...... the interactions in the system are inspected to analyse potential benefit from using a multivariable control strategy in favour of the current strategy based on single loop theory. An analysis of the nonlinear model is carried out to further determine the nonlinear characteristics of the boiler system...... and to verify whether nonlinear control is needed. Finally a controller based on single loop theory is used to analyse if input constraints become active when rejecting transient behaviour from the disturbance steam flow. The model analysis shows large variations in system gains at steady state as function...

  13. Water

    Science.gov (United States)

    Leopold, Luna Bergere; Baldwin, Helene L.

    1962-01-01

    What do you use water for?If someone asked you this question you would probably think right away of water for drinking. Then you would think of water for bathing, brushing teeth, flushing the toilet. Your list would get longer as you thought of water for cooking, washing the dishes, running the garbage grinder. Water for lawn watering, for play pools, for swimming pools, for washing the car and the dog. Water for washing machines and for air conditioning. You can hardly do without water for fun and pleasure—water for swimming, boating, fishing, water-skiing, and skin diving. In school or the public library, you need water to wash your hands, or to have a drink. If your home or school bursts into flames, quantities of water are needed to put it out.In fact, life to Americans is unthinkable without large supplies of fresh, clean water. If you give the matter a little thought, you will realize that people in many countries, even in our own, may suffer from disease and dirt simply because their homes are not equipped with running water. Imagine your own town if for some reason - an explosion, perhaps - water service were cut off for a week or several weeks. You would have to drive or walk to a neighboring town and bring water back in pails. Certainly if people had to carry water themselves they might not be inclined to bathe very often; washing clothes would be a real chore.Nothing can live without water. The earth is covered by water over three-fourths of its surface - water as a liquid in rivers, lakes and oceans, and water as ice and snow on the tops of high mountains and in the polar regions. Only one-quarter of our bodies is bone and muscle; the other three-fourths is made of water. We need water to live, and so do plants and animals. People and animals can live a long time without food, but without water they die in a few days. Without water, everything would die, and the world would turn into a huge desert.

  14. Characterization and hazard evaluation of bottom ash produced from incinerated hospital waste.

    Science.gov (United States)

    Gidarakos, Evangelos; Petrantonaki, Maria; Anastasiadou, Kalliopi; Schramm, Karl-Werner

    2009-12-30

    The uncontrolled disposal of bottom ash from incineration units of hazardous and infected wastes in many countries causes significant scale damage, since it contaminates the soil as well as surface and underground waters, putting both the environment and the public health at risk. In view of the above, a study of bottom ash produced at a hospital medical waste incinerator (HMWI) in Greece was conducted, in order to detect the presence of heavy metals and therefore assess its toxicity; this led to conclusions on the possible contamination of the soil as well as surface and underground waters as a result of its disposal in landfills. The study was conducted at a typical general hospital with 500-bed capacity. About 880 kg of infectious waste coming from a general hospital with all medical departments are pyrolyticly incinerated at the HMWI every day. International literature contains many references to research that characterizes bottom ash as either dangerous, not dangerous, or inert, in an effort to diagnose its proper management and disposal. For this reason, this study focuses on the characterization of bottom ash. Samples were collected from a combustion chamber, over a period of 1 year, and a series of tests were conducted, including an analysis of particle size distribution, morphology, mineralogical and chemical composition, heavy metal leaching behavior and PCDD/F.

  15. Water

    International Nuclear Information System (INIS)

    Chovanec, A.; Grath, J.; Kralik, M.; Vogel, W.

    2002-01-01

    An up-date overview of the situation of the Austrian waters is given by analyzing the status of the water quality (groundwater, surface waters) and water protection measures. Maps containing information of nitrate and atrazine in groundwaters (analyses at monitoring stations), nitrate contents and biological water quality of running waters are included. Finally, pollutants (nitrate, orthophosphate, ammonium, nitrite, atrazine etc.) trends in annual mean values and median values for the whole country for the years 1992-1999 are presented in tables. Figs. 5. (nevyjel)

  16. Water

    CSIR Research Space (South Africa)

    Van Wyk, Llewellyn V

    2010-08-01

    Full Text Available to explore desalination for future capacity. Water is essential to life: the human body is about 75 percent water, with up to 85 percent of brain cells liquid. Around 71 percent of the planet is covered in water, but 97,5 percent of it is salt water... risen to 90 percent, leaving only 10 percent for animals and plants. Yet 40 percent of the water used globally is for sanitation and other uses in buildings. The operation of buildings places a strain on raw water reserves, while wastewater and sewage...

  17. The impact of thermal treatment and cooling methods on municipal solid waste incineration bottom ash with an emphasis on Cl.

    Science.gov (United States)

    Yang, Shuo; Saffarzadeh, Amirhomayoun; Shimaoka, Takayuki; Kawano, Takashi; Kakuta, Yoshitada

    2016-10-01

    Municipal solid waste incineration (MSWI) bottom-ash products possess qualifications to be utilized in cement production. However, the instant use of bottom ash is inhibited by a number of factors, among which the chlorine (Cl) content is always strictly restricted. In this paper, the unquenched MSWI bottom ash was used as the experimental substance, and the influences of thermal treatment and cooling methods on the content and existence of Cl in the ash residues were investigated. The characterization of the MSWI bottom-ash samples examined by utilizing X-ray diffraction, optical microscopy, scanning electron microscopy/energy dispersive X-ray spectroscopy. The experimental results show that as a function of thermal treatment, the reduction rate of Cl is slight below 15.0%, which is relatively low compared with water washing process. Different cooling methods had impacts on the existing forms of Cl. It was understood that most of Cl existed in the glass phase if the bottom ash was air cooled. Contrarily in case of water-quenched bottom ash, Cl could also be accumulated in the newly-formed quench products as chloride salts or hydrate substances such as Friedel's salt.

  18. Water

    Science.gov (United States)

    ... Marion County, Indiana Salt Lake County, Utah Seattle-King County, Washington Tools and Training CLPPP CAP Healthy ... wish to use tap water for drinking or cooking, especially when the water has been off and ...

  19. Peat accumulation in kettle holes: bottom up or top down?

    Directory of Open Access Journals (Sweden)

    G. Gaudig

    2006-12-01

    Full Text Available Rapid peat formation in kettle hole-shaped basins may take place either a by peat forming downwards (top down from a floating mat under stable water level conditions (terrestrialisation, or b by peat forming upwards (bottom up as humus colloids seal off the basin, causing the water level to rise progressively (“kettle hole mire mechanism”. The latter mechanism has hardly been considered in the international literature. The floating-mat mechanism must lead to concave peat isochrones throughout the basin, whereas the kettle hole mire mechanism will yield surface-parallel isochrones. Peat isochrones were studied in three mires occupying kettle hole-shaped basins in north-eastern Germany by comparing pollen samples from the mineral soil–peat interface at different distances from the centre of each mire with the pollen assemblage profile of a central peat core. All three mires appeared to have largely surface-parallel isochrones and must have developed by the kettle hole mire mechanism. In one mire, this mechanism alternated and took place in combination with terrestrialisation following karst subsidence. The fact that evidence of the kettle hole mire mechanism was found at all of the sites investigated indicates that it may be a common peat forming mechanism in kettle hole-shaped basins worldwide.

  20. Bottom-up grammar analysis : a functional formulation

    OpenAIRE

    Jeuring, J.T.; Swierstra, D.

    1994-01-01

    This paper discusses bottom-up grammar analysis problems such as te EMPTY problem and the FIRST problem. It defines a general class of bottom-up grammar analysis problems, and from this definition it derives a functional program for performing bottom-up grammar analysis. The derivation is purely calculational, using theorems from lattice therory, the Bird-Meertens calculus, and laws for list-comprehensions. Sufficient conditions guaranteeing the existence of a solution emerge as a byproduct o...

  1. 49 CFR 179.220-18 - Bottom outlets.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Bottom outlets. 179.220-18 Section 179.220-18... Specifications for Non-Pressure Tank Car Tanks (Classes DOT-111AW and 115AW) § 179.220-18 Bottom outlets. (a) The inner container may be equipped with a bottom outlet of approved design and an opening provided in the...

  2. Trace elements in bottom sediments of the Barents Sea on the standard section "Kola Meridian"

    Directory of Open Access Journals (Sweden)

    Lapteva A. M.

    2017-03-01

    Full Text Available The levels of trace metals (Cu, Zn, Ni, Cr, Mn, Co, Pb, Cd, Hg and arsenic (As in samples of bottom sediments from the Barents Sea on eight stations of the standard section "Kola Meridian" have been investigated. Trace elements have been determined on atomic absorption spectrophotometer AA-6800 with mercury-hydride attachment HVG-1 of the company Shimadzu (Japan by the methods of flaming (acetylene – air and electrothermal atomization. Common and very toxic trace elements include Pb, Cd, As, and Hg. It is believed that 90 % of lead, 70–80 % of cadmium, and arsenic, over 30 % of mercury in the atmosphere are of anthropogenic origin, and emissions of these elements in the atmosphere are almost completely manufactured in the Northern Hemisphere. The main sources of income in the Barents Sea are waters of the North Atlantic current and the large-scale atmospheric transport from industrialized Central Europe. As a rule the spatial distribution of trace elements is in good agreement with the granulometric composition of bottom sediments and the content of organic carbon. The contents of most of the listed trace elements in samples of bottom sediments on the standard section "Kola Meridian" in the Norwegian classification are consistent with background levels with the exception of Ni, Cr, and As. Their content in bottom sediments at some stations has met the criteria for "slight" and "moderate" pollution. The obtained results confirm the insignificant levels of contamination of bottom sediments of some trace elements. On the status of stocks of commercial species of aquatic biological resources, the observed levels of contamination of bottom sediments in the investigated areas of the Barents Sea will have no significant effect

  3. Further studies of flow and reactive pollutant dispersion in a street canyon with bottom heating

    Science.gov (United States)

    Kang, Yoon-So; Baik, Jong-Jin; Kim, Jae-Jin

    This study numerically investigates how flow and reactive pollutant dispersion in a street canyon with a canyon aspect ratio of one vary with the street-bottom heating intensity. For this, numerical simulations are performed over a wide range of street-bottom heating intensities (Δ T=0-15 °C in 1 °C intervals) using a Reynolds-averaged Navier-Stokes equations (RANS) model with NO-NO 2-O 3 photochemistry. The pollutants NO and NO 2 are emitted from near the street bottom in the presence of background O 3. A primary vortex is formed in the street canyon in all the simulated cases, but the location of the vortex center at the cross-canyon plane becomes quasi-stationary or meanders in the street canyon, depending on the street-bottom heating intensity. The time series of the street canyon-averaged NO concentration at the cross-canyon plane exhibits a quasi-steady, oscillatory, or fluctuating pattern, depending on the street-bottom heating intensity. As the street-bottom heating intensity increases, the averaged NO and NO 2 concentrations tend to decrease and the magnitude of the roof-level area-integrated and time-averaged vertical mean (turbulent) flux between Δ T=2 and 13 °C tends to increase (decrease). Some peculiar features are found in the cases of Δ T=11, 12, and 13 °C in which there are strong downward motion near the downwind building wall, downward motion below the roof level near the upwind building wall, and strong reverse flow in the lower region of the street canyon. Moreover, the vortex center is shifted toward the upwind building wall and does not meander in the street canyon after a certain period of time. Following the downward motions below the roof level, the O 3-containing ambient air is considerably entrained into the street canyon, resulting in a large increase in the O 3 concentration in the street canyon. In the cases of Δ T=11, 12, and 13 °C, the magnitude of the vertical mean flux is larger than that of the vertical turbulent flux

  4. Deep Water Survey Data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The deep water biodiversity surveys explore and describe the biodiversity of the bathy- and bentho-pelagic nekton using Midwater and bottom trawls centered in the...

  5. Near 7-day response of ocean bottom pressure to atmospheric surface pressure and winds in the northern South China Sea

    Science.gov (United States)

    Zhang, Kun; Zhu, Xiao-Hua; Zhao, Ruixiang

    2018-02-01

    Ocean bottom pressures, observed by five pressure-recording inverted echo sounders (PIESs) from October 2012 to July 2014, exhibit strong near 7-day variability in the northern South China Sea (SCS) where long-term in situ bottom pressure observations are quite sparse. This variability was strongest in October 2013 during the near two years observation period. By joint analysis with European Center for Medium-Range Weather Forecasts (ECMWF) data, it is shown that the near 7-day ocean bottom pressure variability is closely related to the local atmospheric surface pressure and winds. Within a period band near 7 days, there are high coherences, exceeding 95% significance level, of observed ocean bottom pressure with local atmospheric surface pressure and with both zonal and meridional components of the wind. Ekman pumping/suction caused by the meridional component of the wind in particular, is suggested as one driving mechanism. A Kelvin wave response to the near 7-day oscillation would propagate down along the continental slope, observed at the Qui Nhon in the Vietnam. By multiple and partial coherence analyses, we find that local atmospheric surface pressure and Ekman pumping/suction show nearly equal influence on ocean bottom pressure variability at near 7-day periods. A schematic diagram representing an idealized model gives us a possible mechanism to explain the relationship between ocean bottom pressure and local atmospheric forcing at near 7-day periods in the northern SCS.

  6. Aquatic Habitat Bottom Classification Using ADCP

    Science.gov (United States)

    Description of physical aquatic habitat often includes data describing distributions of water depth, velocity and bed material type. Water depth and velocity in streams deeper than about 1 m may be continuously mapped using an acoustic Doppler current profiler from a moving boat. Herein we examine...

  7. Construction of water intake facilities from partially drying up watercourses

    Directory of Open Access Journals (Sweden)

    Orlov Evgeniy Vladimirovich

    Full Text Available Partially ephemeral streams are complex objects that can still be used for water supply or irrigation of agricultural land. The problem of such streams is poorly studied, because the influence of various environmental factors complicates carrying out any experiments. Also it is not possible to make their full classification due to their very strong variability not only on a particular geographical belt, but also within separate areas of the river. All this undoubtedly complicates the task of the designers when designing the system. Creation of laboratory models, allowing us to evaluate the possibilities of a spring use for the purpose of water supply, is very promising. These watercourses have a large amount of suspended sediments, so it is not possible to use the standard scheme of water using of the coastal and fluvial water intake structures. It is proposed to organize the fight with the sediments in the flow chart of primary clarifiers, which will perform the function of settling suspensions, to facilitate the work of water treatment facilities. Also the creation of artificial prop is useful in order to achieve the required level of water in a watercourse for water organization. If under the bottom of the river there is underground water, and the permeability of the soil is good, it is possible to arrange the withdrawal of water through infiltration intakes, by setting the filter under the bottom of the watercourse with its connection to filter, from which the water will climb to submersible pumps. Additional filtration through the soil of the river bottom allows not using the scheme sumps, which significantly reduces the cost of epy incoming water treatment.

  8. The muddy bottom sediments of the old river beds of the lower Vistula

    Directory of Open Access Journals (Sweden)

    Mimier Daria

    2016-03-01

    Full Text Available The main objective of this study was to characterize the muddy bottom sediments of three hydrologically different old river beds of the lower Vistula, located in the vicinity of Toruń: Port Drzewny, Martwa Wisła and Przybysz. Samples were taken at monthly intervals from April to November 2015 from two (Martwa Wisła and Przybysz or three sampling sites (Port Drzewny located in the central parts of the reservoirs. The bottom sediments of these water bodies were characterized by a low water content and organic matter content expressed as a percentage of dry weight, high organic matter content expressed in units of weight, as well as a high sediment oxygen demand. The most distinct reservoir was Martwa Wisła, most likely due to the lack of a connection with the River Vistula.

  9. Method and apparatus for disposing a radioactive waste container to submarine bottom

    International Nuclear Information System (INIS)

    Shibata, Kiyoshi; Yoshida, Shoichi.

    1980-01-01

    Purpose: To completely eliminate a danger occurred by the rolling of a hull in the ocean in a method and apparatus for disposing radioactive waste container to submarine bottom by independently handling the radioactive waste containers when loading the container in a compartment carried on a barge and sinking the containers together with the compartment to the submarine bottom at its disposing time. Method: Radioactive waste containers are carried into a compartment loaded on a barge floating completely, and the barge is then applied with external force thereto by a ship or the like and sailed to the marine disposal area. Then, water is filled in the ballast tank of the barge to submerge the barge, the compartment is floated and separated from the containers, and water is charged into the compartment to sink the compartment. (Aizawa, K.)

  10. Drag-based 'hovering' in ducks: the hydrodynamics and energetic cost of bottom feeding.

    Directory of Open Access Journals (Sweden)

    Gal Ribak

    Full Text Available Diving ducks use their webbed feet to provide the propulsive force that moves them underwater. To hold position near the bottom while feeding, ducks paddle constantly to resist the buoyant force of the body. Using video sequences from two orthogonal cameras we reconstructed the 3-dimensional motion of the feet through water and estimated the forces involved with a quasi-steady blade-element model. We found that during station holding, near the bottom, ducks use drag based propulsion with the webbed area of the foot moving perpendicular to the trajectory of the foot. The body was pitched at 76+/-3.47 degrees below the horizon and the propulsive force was directed 26+/-1.9 degrees ventral to the body so that 98% of the propulsive force in the sagittal plane of the duck worked to oppose buoyancy. The mechanical work done by moving both feet through a paddling cycle was 1.1+/-0.2 J which was equivalent to an energy expenditure of 3.7+/-0.5 W to hold position while feeding at 1.5 m depth. We conclude that in shallow water the high energetic cost of feeding in ducks is due to the need to paddle constantly against buoyancy even after reaching the bottom. The mechanical energy spent on holding position near the bottom, while feeding, is approximately 2 fold higher than previous estimates that were made for similar bottom depths but based on the presumed motion of the body instead of motion of the feet.

  11. How Service Innovation Boosts Bottom Lines

    Directory of Open Access Journals (Sweden)

    Claude Legrand

    2013-09-01

    Full Text Available In the national quest for ground-breaking R&D discoveries and inventions, service innovation is frequently ignored at considerable cost to an organization’s bottom line and a nation’s productivity. For the fact is that innovation applied systematically to all activities outside of R&D can make the difference between uninspiring results and substantial growth in every sector. Many countries, in particular in Europe, have recognized the importance of service innovation and are devoting considerable resources to research, the capture of best practices, and the measurement of progress and success. Given the physiognomy of the modern economy, it does not make sense for leaders in the Canadian public sector to devote all available innovation investment dollars to science and technology R&D. This article explores why service innovation is not yet a priority on the innovation agenda in Canada and why we should correct the dangerous misconception that there is just one “innovation gap” that needs to be addressed. It provides practical recommendations that public and private sector leaders can use to take advantage of this under-valued, high-potential innovation opportunity and calls for the creation of a national service innovation resource to support enterprises of all sizes as a means to improve Canadian productivity.

  12. Sensitivity analyses of the peach bottom turbine trip 2 experiment

    International Nuclear Information System (INIS)

    Bousbia Salah, A.; D'Auria, F.

    2003-01-01

    In the light of the sustained development in computer technology, the possibilities for code calculations in predicting more realistic transient scenarios in nuclear power plants have been enlarged substantially. Therefore, it becomes feasible to perform 'Best-estimate' simulations through the incorporation of three-dimensional modeling of reactor core into system codes. This method is particularly suited for complex transients that involve strong feedback effects between thermal-hydraulics and kinetics as well as to transient involving local asymmetric effects. The Peach bottom turbine trip test is characterized by a prompt core power excursion followed by a self limiting power behavior. To emphasize and understand the feedback mechanisms involved during this transient, a series of sensitivity analyses were carried out. This should allow the characterization of discrepancies between measured and calculated trends and assess the impact of the thermal-hydraulic and kinetic response of the used models. On the whole, the data comparison revealed a close dependency of the power excursion with the core feedback mechanisms. Thus for a better best estimate simulation of the transient, both of the thermal-hydraulic and the kinetic models should be made more accurate. (author)

  13. Chemical sequential extraction of heavy metals and sulphur in bottom ash and in fly ash from a pulp and paper mill complex.

    Science.gov (United States)

    Nurmesniemi, Hannu; Pöykiö, Risto; Kuokkanen, Toivo; Rämö, Jaakko

    2008-08-01

    A five-stage sequential extraction procedure was used to determine the distribution of 11 metals (Cd, Cr, Cu, Mo, Pb, Zn, As, Co, V, Ni, Ba), and sulphur (S) in bottom ash and in fly ash from a fluidized bed co-combustion (i.e. wood and peat) boiler of Stora Enso Oyj Oulu Mill at Oulu, Northern Finland, into the following fractions: (1) water-soluble fraction (H2O); (2) exchangeable fraction (CH3COOH); (3) easily reduced fraction (NH2OH-HCl); (4) oxidizable fraction (H2O2 + CH3COONH4); and (5) residual fraction (HF + HNO3 + HCl). Although metals were extractable in all fractions, the highest concentrations of most of the metals occurred in the residual fraction. From the environmental point of view, this fraction is the non-mobile fraction and is potentially the least harmful. The Ca concentrations of 29.3 g kg(-1) (dry weight) in bottom ash and of 68.5 g kg(-1) (dry weight) in fly ash were correspondingly approximately 18 and 43 times higher than the average value of 1.6 g kg(-1) (dry weight) in arable land in Central Finland. The ashes were strongly alkaline pH (approximately 12) and had a liming effects of 9.3% (bottom ash) and 13% (fly ash) expressed as Ca equivalents (dry weight). The elevated Ca concentrations indicate that the ashes are potential agents for soil remediation and for improving soil fertility. The pH and liming effect values indicate that the ashes also have a pH buffering capacity. From the environmental point of view, it is notable that the heavy metal concentrations in both types of ash were lower than the Finnish criteria for ash utilization.

  14. Ocean-bottom pressure changes above a fault area for tsunami excitation and propagation observed by a submarine dense network

    Science.gov (United States)

    Yomogida, K.; Saito, T.

    2017-12-01

    Conventional tsunami excitation and propagation have been formulated by incompressible fluid with velocity components. This approach is valid in most cases because we usually analyze tunamis as "long gravity waves" excited by submarine earthquakes. Newly developed ocean-bottom tsunami networks such as S-net and DONET have dramatically changed the above situation for the following two reasons: (1) tsunami propagations are now directly observed in a 2-D array manner without being suffered by complex "site effects" of sea shore, and (2) initial tsunami features can be directly detected just above a fault area. Removing the incompressibility assumption of sea water, we have formulated a new representation of tsunami excitation based on not velocity but displacement components. As a result, not only dynamics but static term (i.e., the component of zero frequency) can be naturally introduced, which is important for the pressure observed on the ocean floor, which ocean-bottom tsunami stations are going to record. The acceleration on the ocean floor should be combined with the conventional tsunami height (that is, the deformation of the sea level above a given station) in the measurement of ocean-bottom pressure although the acceleration exists only during fault motions in time. The M7.2 Off Fukushima earthquake on 22 November 2016 was the first event that excited large tsunamis within the territory of S-net stations. The propagation of tsunamis is found to be highly non-uniform, because of the strong velocity (i.e., sea depth) gradient perpendicular to the axis of Japan Trench. The earthquake was located in a shallow sea close to the coast, so that all the tsunami energy is reflected by the trench region of high velocity. Tsunami records (pressure gauges) within its fault area recorded clear slow motions of tsunamis (i.e., sea level changes) but also large high-frequency signals, as predicted by our theoretical result. That is, it may be difficult to extract tsunami

  15. High fire resistance in blocks containing coal combustion fly ashes and bottom ash.

    Science.gov (United States)

    García Arenas, Celia; Marrero, Madelyn; Leiva, Carlos; Solís-Guzmán, Jaime; Vilches Arenas, Luis F

    2011-08-01

    Fire resistance recycled blocks, containing fly ash and bottom ash from coal combustion power plants with a high fire resistance, are studied in this paper by testing different compositions using Portland cement type II, sand, coarse aggregate and fly ash (up to 50% of total weight) and bottom ash (up to 30% of total weight). The fire resistance, physical-chemical (density, pH, humidity, and water absorption capacity), mechanical (compressive and flexural strength), and leaching properties are measured on blocks made with different proportions of fly ash and bottom ash. The standard fire resistance test is reproduced on 28cm-high, 18cm-wide and 3cm-thick units, and is measured as the time needed to reach a temperature of 180°C on the non-exposed surface of the blocks for the different compositions. The results show that the replacement of fine aggregate with fly ash and of coarse aggregate with bottom ash have a remarkable influence on fire resistance and cause no detriment to the mechanical properties of the product. Additionally, according to the leaching tests, no environmental problems have been detected in the product. These results lead to an analysis of the recycling possibilities of these by-products in useful construction applications for the passive protection against fire. Copyright © 2011 Elsevier Ltd. All rights reserved.

  16. Bottom-up approaches for preparing drug nanocrystals: formulations and factors affecting particle size.

    Science.gov (United States)

    Sinha, Biswadip; Müller, Rainer H; Möschwitzer, Jan P

    2013-08-30

    The solubility dependent bioavailability problem has become a major hurdle in drug development processes. Drug nanocrystals have been widely accepted by the pharmaceutical industry to improve the bioavailability of poorly water-soluble compounds. Top-down and bottom-up technologies are the two primary technical approaches of drug nanocrystal production. Though the top-down approach has been hugely successful on the commercial front, it has some inherent drawbacks that necessitate the emergence of alternate approaches. The bottom-up approach has not yet been established as a successful commercial technology. However, it has the potential to produce small size drug nanocrystals with less energy demanding processes. The bottom-up approach is commonly known as precipitation technique. It would be possible to stabilize particles at an early stage of precipitation and to generate drug nanocrystals. In the first part of this review article, we have discussed various bottom-up technologies that are currently in use. This has been followed by description and analysis of various process parameters that can affect the final particle size of the drug nanocrystals. Copyright © 2013 Elsevier B.V. All rights reserved.

  17. The Study on Stability and Seakeeping Characteristics of the Glass Bottom Boat Trimaran in Karimunjawa Island

    Science.gov (United States)

    Arswendo Adietya, Berlian; Windyandari, Aulia; Fauzan Zakki, Ahmad

    2018-03-01

    Recently the diversity of fish populations in the waters Karimunjawa Island is only appreciated by those who have the ability to play diving and snorkeling. It is due to the unavailability of a vehicle that is specially made to delight in the fascination of the underwater panorama. One of the alternative solutions is using the glass bottom boat technology which is using transparent bottom that might look out the underwater scenery instead of swimming and snorkeling. The paper has focused on the study of intact stability and seakeeping characteristics of glass bottom boat trimaran in Karimunjawa Island. The intact stability characteristics will be investigated at the various load cases and weight distribution configurations which are influenced by the passenger positions and fuel tank condition. Regarding the seakeeping performance analysis, the ITTC-Bretschneider will be adopted as the wave spectrum at the wave parameters defined from the operational environment. The influence of the parameters on the stability and seakeeping of the glass bottom boat trimaran are presented and discussed.

  18. Heavy metal concentrations in Bottom Sediments of Ikpoba River ...

    African Journals Online (AJOL)

    MICHAEL HORSFALL

    2014-06-23

    Jun 23, 2014 ... March 2014. Vol. 18 (1) 27-32. Full-text Available Online at www.ajol.info and www.bioline.org.br/ja. Heavy metal concentrations in Bottom Sediments of Ikpoba River, Edo State, Nigeria. *1 ... Introduction: Bottom sediment is an integral part of the abiotic ... bank of this station includes bamboo trees, grasses.

  19. Use of Unprocessed Coal Bottom Ash as Partial Fine Aggregate ...

    African Journals Online (AJOL)

    2012r

    plastic density to decrease and bleeding to increase. Moreover, above 40% replacement of bottom ash, compressive strength, flexural strength, and modulus of elasticity decreased sharply. In addition, an increase in bottom ash content improved the drying shrinkage performance of the concrete. The research also.

  20. Postcolonial Appalachia: Bhabha, Bakhtin, and Diane Gilliam Fisher's "Kettle Bottom"

    Science.gov (United States)

    Stevenson, Sheryl

    2006-01-01

    Diane Gilliam Fisher's 2004 award-winning book of poems, "Kettle Bottom," offers students a revealing vantage point for seeing Appalachian regional culture in a postcolonial context. An artful and accessible poetic sequence that was selected as the 2005 summer reading for entering students at Smith College, "Kettle Bottom"…

  1. Hudson River Sub-Bottom Profile Points

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Hudson River Estuary Shallow Water Surveys. Subbottom Profile Points. Subbottom data was collected November 5 to December 15, 2009, in the estuary north from...

  2. Water

    OpenAIRE

    Hertie School of Governance

    2010-01-01

    All human life depends on water and air. The sustainable management of both is a major challenge for today's public policy makers. This issue of Schlossplatz³ taps the streams and flows of the current debate on the right water governance.

  3. THERMAL CONDUCTANCE IN AQUATIC BIRDS IN RELATION TO THE DEGREE OF WATER CONTACT, BODY-MASS, AND BODY-FAT - ENERGETIC IMPLICATIONS OF LIVING IN A STRONG COOLING ENVIRONMENT

    NARCIS (Netherlands)

    DEVRIES, J; VANEERDEN, MR

    1995-01-01

    Thermal conductance of carcasses of 14 aquatic bird species was determined by the warming constant technique. The effect on thermal conductance of body mass, age sex, fat deposits, and the degree of contact with water were studied. Only body mass and the degree of submergence in water had an effect.

  4. Characterization of Fly and Bottom Ashes Mixtures Treated using Sodium Lauryl Sulphate and Polyvinyl Alcohol

    Science.gov (United States)

    Robert, C. G.; Ayob, A.; Zaki, M. F. Muhammad; Razali, M. E.; Lew, E. V.; Hong, P. Y.

    2018-03-01

    Malaysia promotes coal as an option for solid fuel in electric power generation. Demanding of electricity needs, therefore, has led to increase the coal consumption and thus producing more coal waste products. The disposal of coal waste ashes has been a main concern to power generation station due to the need of disposal sites and operational costs. This study investigates the composition of fly ash (FA) and bottom ash (BA) mixtures with difference component percentage treated with sodium lauryl sulphate (SLS) and polyvinyl alcohol (PVA) at 1.5 and 2.5 wt% solutions and examined in terms of specific gravity, pH, maximum dry density properties, and its surface morphology. Although the chemical composition of the SLS and PVA treated fly and bottom ashes studied in this current work is not altered extensively, significant changes could be observed in its physicochemical properties. Chemically treated fly and bottom ashes mixtures with SLS and PVA at 1.5 wt% solution exhibited specific gravity of 1.97 to 2.92 and high pH values within range of 9.28 to 10.52. The mixture of BA:FA=0:1 ratio depicting high maximum dry density of 1.35 to 1.56 g/cm3 in both SLS and PVA solutions at 1.5 and 2.5 wt%. Scanning electron microscopy image shows distinct surface morphologies of SLS-treated fly and bottom ashes mixture that the particles are packed closely, strongly bonded similar to popcorn shape due to the effect of active silanol groups acted on coal ashes surface with the presence of Al-O/Si-O/other oxides. These findings suggest that higher level of chemical interaction between the fly and bottom ashes particles, significantly enhances pozzolanic reactions such as shear strength, plasticity, cementing properties, and thus other engineering properties.

  5. Characterization of Fly and Bottom Ashes Mixtures Treated using Sodium Lauryl Sulphate and Polyvinyl Alcohol

    Directory of Open Access Journals (Sweden)

    Robert C.G.

    2018-01-01

    Full Text Available Malaysia promotes coal as an option for solid fuel in electric power generation. Demanding of electricity needs, therefore, has led to increase the coal consumption and thus producing more coal waste products. The disposal of coal waste ashes has been a main concern to power generation station due to the need of disposal sites and operational costs. This study investigates the composition of fly ash (FA and bottom ash (BA mixtures with difference component percentage treated with sodium lauryl sulphate (SLS and polyvinyl alcohol (PVA at 1.5 and 2.5 wt% solutions and examined in terms of specific gravity, pH, maximum dry density properties, and its surface morphology. Although the chemical composition of the SLS and PVA treated fly and bottom ashes studied in this current work is not altered extensively, significant changes could be observed in its physicochemical properties. Chemically treated fly and bottom ashes mixtures with SLS and PVA at 1.5 wt% solution exhibited specific gravity of 1.97 to 2.92 and high pH values within range of 9.28 to 10.52. The mixture of BA:FA=0:1 ratio depicting high maximum dry density of 1.35 to 1.56 g/cm3 in both SLS and PVA solutions at 1.5 and 2.5 wt%. Scanning electron microscopy image shows distinct surface morphologies of SLS-treated fly and bottom ashes mixture that the particles are packed closely, strongly bonded similar to popcorn shape due to the effect of active silanol groups acted on coal ashes surface with the presence of Al-O/Si-O/other oxides. These findings suggest that higher level of chemical interaction between the fly and bottom ashes particles, significantly enhances pozzolanic reactions such as shear strength, plasticity, cementing properties, and thus other engineering properties.

  6. Bottom-feeding for blockbuster businesses.

    Science.gov (United States)

    Rosenblum, David; Tomlinson, Doug; Scott, Larry

    2003-03-01

    Marketing experts tell companies to analyze their customer portfolios and weed out buyer segments that don't generate attractive returns. Loyalty experts stress the need to aim retention programs at "good" customers--profitable ones- and encourage the "bad" ones to buy from competitors. And customer-relationship-management software provides ever more sophisticated ways to identify and eliminate poorly performing customers. On the surface, the movement to banish unprofitable customers seems reasonable. But writing off a customer relationship simply because it is currently unprofitable is at best rash and at worst counterproductive. Executives shouldn't be asking themselves, How can we shun unprofitable customers? They need to ask, How can we make money off the customers that everyone else is shunning? When you look at apparently unattractive segments through this lens, you often see opportunities to serve those segments in ways that fundamentally change customer economics. Consider Paychex, a payroll-processing company that built a nearly billion-dollar business by serving small companies. Established players had ignored these customers on the assumption that small companies couldn't afford the service. When founder Tom Golisano couldn't convince his bosses at Electronic Accounting Systems that they were missing a major opportunity, he started a company that now serves 390,000 U.S. customers, each employing around 14 people. In this article, the authors look closely at bottom-feeders--companies that assessed the needs of supposedly unattractive customers and redesigned their business models to turn a profit by fulfilling those needs. And they offer lessons other executives can use to do the same.

  7. A Record-High Ocean Bottom Pressure in the South Pacific Observed by GRACE

    Science.gov (United States)

    Boening, Carmen; Lee, Tong; Zlotnicki, Victor

    2011-01-01

    In late 2009 to early 2010, the Gravity Recovery and Climate Experiment (GRACE) satellite pair observed a record increase in ocean bottom pressure (OBP) over a large mid-latitude region of the South East Pacific. Its magnitude is substantially larger than other oceanic events in the Southern Hemisphere found in the entire GRACE data records (2003-2010) on multi-month time scales. The OBP data help to understand the nature of a similar signal in sea surface height (SSH) anomaly observed by altimetry: the SSH increase is mainly due to mass convergence. Analysis of the barotropic vorticity equation using scatterometer data, atmospheric reanalysis product, and GRACE and altimeter an atmospheric reanalysis product observations suggests that the observed OBP/SSH signal was primarily caused by wind stress curl associated with a strong and persistent anticyclone in late 2009 in combination with effects of planetary vorticity gradient, bottom topography, and friction

  8. Eddy current testing system for bottom mounted instrumentation welds

    International Nuclear Information System (INIS)

    Kobayashi, N.; Ueno, S.; Suganuma, N.; Oodake, T.; Maehara, T.; Kasuya, T.; Ichikawa, H.

    2015-01-01

    Eddy current testing (ECT) techniques are used to detect a defect, especially stress corrosion cracking. An ECT system and procedures have been developed for testing the bottom mounted instrumentation (BMI) weld area of the reactor vessel in a pressurized water reactor. It is difficult to position and move the probe on the BMI weld area because the area has complicated curved surfaces. The surface shape of weld area on the BMI mock-up was measured for generating the scanning trajectory of ECT probe. The space coordinates and the normal vectors at the scanning points as the scanning trajectory were calculated based on the measured results of weld surface shape. Each motion-axis position of the multi-axis robot corresponding to each scanning point was calculated by the inverse kinematic algorithm. The BMI mock-up test was performed using the developed ECT probe with the cross coil in the differential mode. The artificial SCC and EDM slits given on the build-up weld area were detected in the mock-up test. From the result of detecting defects, it is shown that this ECT system can detect a defect of approximately 2.3 mm in length, 0.5 mm in depth and 0.2 mm in width as the defect detection capability for the BMI welds. It was estimated that the average and the maximum probe tilt angles were 2.6 and 8.5 degrees, respectively

  9. Seasonal cycle of near-bottom transport and currents in the northern Gulf of California

    Science.gov (United States)

    Navarro, R.; López, M.; Candela, J.

    2016-12-01

    Seasonal cycles of near-bottom transport and temperature over the sills of the Northern Gulf of California, as well as surface geostrophic velocity anomalies, are presented. Transport at the sills, where overflows occur, is toward the head of the gulf all year round with maximum in October and minimum in June. Furthermore, transport is 180° out of phase with the surface geostrophic velocity across the northern gulf, consistent with the exchange being strongest in October. Seasonal cycles of near-bottom temperature and transport are also 180° out of phase, indicating that maximum water inflow is associated with the coolest water entering from the Pacific Ocean. Near-bottom temperature over the northern Ballenas Channel sill has a maximum in early August, which is more in phase with the surface temperature and consistent with intense mixing in the channel. Geostrophic velocity at the northern gulf is in phase with that near the mouth of the gulf, and approximately in phase with the seasonal heat input through the mouth, calculated previously by Beron-Vera and Ripa (2000). Moreover, the maximum lower-layer, horizontal heat output of the Ballenas Channel occurs in November, approximately one month after the maximum transport through the San Lorenzo and Delfín sills. Therefore, heat loss results from the continuous near-bottom inflow of relatively cold water at both sills which bound the deepest basins of the northern gulf. Moreover, the mean and seasonal cycles of heat and mass fluxes in the deepest basins of the northern gulf are almost everywhere in opposite directions.

  10. Water

    Directory of Open Access Journals (Sweden)

    E. Sanmuga Priya

    2017-05-01

    Full Text Available Phytoremediation through aquatic macrophytes treatment system (AMATS for the removal of pollutants and contaminants from various natural sources is a well established environmental protection technique. Water hyacinth (Eichhornia crassipes, a worst invasive aquatic weed has been utilised for various research activities over the last few decades. The biosorption capacity of the water hyacinth in minimising various contaminants present in the industrial wastewater is well studied. The present review quotes the literatures related to the biosorption capacity of the water hyacinth in reducing the concentration of dyestuffs, heavy metals and minimising certain other physiochemical parameters like TSS (total suspended solids, TDS (total dissolved solids, COD (chemical oxygen demand and BOD (biological oxygen demand in textile wastewater. Sorption kinetics through various models, factors influencing the biosorption capacity, and role of physical and chemical modifications in the water hyacinth are also discussed.

  11. Quantum electrodynamics of strong fields

    International Nuclear Information System (INIS)

    Greiner, W.

    1983-01-01

    Quantum Electrodynamics of Strong Fields provides a broad survey of the theoretical and experimental work accomplished, presenting papers by a group of international researchers who have made significant contributions to this developing area. Exploring the quantum theory of strong fields, the volume focuses on the phase transition to a charged vacuum in strong electric fields. The contributors also discuss such related topics as QED at short distances, precision tests of QED, nonperturbative QCD and confinement, pion condensation, and strong gravitational fields In addition, the volume features a historical paper on the roots of quantum field theory in the history of quantum physics by noted researcher Friedrich Hund

  12. Improving bottom-boundary conditions for SVAT simulations in shallow-groundwater systems

    Science.gov (United States)

    Morris, Paul J.; Verhoef, Anne; Macdonald, David M. J.; Gardner, Cate M.; Punalekar, Suvarna M.; Tatarenko, Irina; Gowing, David

    2013-04-01

    A well documented disparity exists between models that simulate: i) groundwater hydrological processes; and ii) soil-vegetation-atmosphere transfers (SVAT) of water and energy. This is particularly pertinent in shallow groundwater systems, such as lowland floodplains, where the domains of surface water and groundwater necessarily overlap. Consideration of either SVAT or groundwater processes in shallow groundwater systems necessitates a robust understanding of their bi-directional interactions. The hydrological bottom-boundary conditions of SVAT models can be driven using continuous groundwater data from dipwells. However, where such data are not available the bottom boundary must be simulated. We sought to develop a simple empirical model of subsurface fluxes of water between a floodplain soil column and its adjoining river, without the additional cost and complication of a fully linked surface water-groundwater model. We conducted our research at Yarnton Mead, a floodplain meadow on the River Thames in Oxfordshire, UK. We used in-situ soil-physical, hydrological and meteorological data to generate an empirical relationship between floodplain water-table position, and rate and direction of subsurface water fluxes between the floodplain soil and the river. We estimated rates of subsurface water flux into and out of our instrumented soil column as the residual term of a water balance equation. We then fitted a linear model to describe the rate and direction of subsurface flux as a function of water-table position. Although the level of explanation of the linear model is not high (r-squared = 0.39), the relationship is highly significant (p validated the model's simulated water tables against dipwell measurements. The simulated water tables fitted well to observed data with root mean square error of 0.13 m and r-squared = 0.71. The fit could be improved further by optimising the slope and intercept of the linear model. Our results are highly promising and suggest

  13. Stimulation of methane oxidation potential and effects on vegetation growth by bottom ash addition in a landfill final evapotranspiration cover.

    Science.gov (United States)

    Kim, Gil Won; Ho, Adrian; Kim, Pil Joo; Kim, Sang Yoon

    2016-09-01

    The landfilling of municipal solid waste is a significant source of atmospheric methane (CH4), contributing up to 20% of total anthropogenic CH4 emissions. The evapotranspiration (ET) cover system, an alternative final cover system in waste landfills, has been considered to be a promising way to mitigate CH4 emissions, as well as to prevent water infiltration using vegetation on landfill cover soils. In our previous studies, bottom ash from coal-fired power plants was selected among several industrial residues (blast furnace slag, bottom ash, construction waste, steel manufacture slag, stone powder sludge, and waste gypsum) as the best additive for ET cover systems, with the highest mechanical performance achieved for a 35% (wtwt(-1)) bottom ash content in soil. In this study, to evaluate the field applicability of bottom ash mixed soil as ET cover, four sets of lysimeters (height 1.2m×width 2m×length 6m) were constructed in 2007, and four different treatments were installed: (i) soil+bottom ash (35% wtwt(-1)) (SB); (ii) soil+compost (2% wtwt(-1), approximately corresponding to 40Mgha(-1) in arable field scale) (SC); (iii) soil+bottom ash+compost (SBC); and (iv) soil only as the control (S). The effects of bottom ash mixing in ET cover soil on CH4 oxidation potential and vegetation growth were evaluated in a pilot ET cover system in the 5th year after installation by pilot experiments using the treatments. Our results showed that soil properties were significantly improved by bottom ash mixing, resulting in higher plant growth. Bottom ash addition significantly increased the CH4 oxidation potential of the ET cover soil, mainly due to improved organic matter and available copper concentration, enhancing methanotrophic abundances in soil amended with bottom ash. Conclusively, bottom ash could be a good alternative as a soil additive in the ET cover system to improve vegetation growth and mitigate CH4 emission impact in the waste landfill system. Copyright © 2016

  14. Assessment of engineering plant analyzer with Peach Bottom 2 stability tests

    International Nuclear Information System (INIS)

    Rohatgi, U.S.; Mallen, A.N.; Cheng, H.S.; Wulff, W.

    1992-01-01

    Engineering Plant Analyzer (EPA) has been developed to simulate plant transients for Boiling Water Reactor (BWR). Recently, this code has been used to simulate LaSalle-2 instability event which was initiated by a failure in the feed water heater. The simulation was performed for the scram conditions and for the postulated failure in the scram. In order to assess the capability of the EPA to simulate oscillatory flows as observed in the LaSalle event, EPA has been benchmarked with the available data from the Peach Bottom 2 (PB2) Instability tests PT1, PT2, and PT4. This document provides a description of these tests

  15. Properties and Leachability of Self-Compacting Concrete Incorporated with Fly Ash and Bottom Ash

    Science.gov (United States)

    Kadir, Aeslina Abdul; Ikhmal Haqeem Hassan, Mohd; Jamaluddin, Norwati; Bakri Abdullah, Mohd Mustafa Al

    2016-06-01

    The process of combustion in coal-fired power plant generates ashes, namely fly ash and bottom ash. Besides, coal ash produced from coal combustion contains heavy metals within their compositions. These metals are toxic to the environment as well as to human health. Fortunately, treatment methods are available for these ashes, and the use of fly ash and bottom ash in the concrete mix is one of the few. Therefore, an experimental program was carried out to study the properties and determine the leachability of selfcompacting concrete incorporated with fly ash and bottom ash. For experimental study, self-compacting concrete was produced with fly ash as a replacement for Ordinary Portland Cement and bottom ash as a replacement for sand with the ratios of 10%, 20%, and 30% respectively. The fresh properties tests conducted were slump flow, t500, sieve segregation and J-ring. Meanwhile for the hardened properties, density, compressive strength and water absorption test were performed. The samples were then crushed to be extracted using Toxicity Characteristic Leaching Procedure and heavy metals content within the samples were identified accordingly using Atomic Absorption Spectrometry. The results demonstrated that both fresh and hardened properties were qualified to categorize as self-compacting concrete. Improvements in compressive strength were observed, and densities for all the samples were identified as a normal weight concrete with ranges between 2000 kg/m3 to 2600 kg/m3. Other than that, it was found that incorporation up to 30% of the ashes was safe as the leached heavy metals concentration did not exceed the regulatory levels, except for arsenic. In conclusion, this study will serve as a reference which suggests that fly ash and bottom ash are widely applicable in concrete technology, and its incorporation in self-compacting concrete constitutes a potential means of adding value to appropriate mix and design.

  16. Horns Rev offshore wind farm. Introducing hard bottom substrate sea bottom and marine biology. Data report 2001

    International Nuclear Information System (INIS)

    Leonhard, S.B.; Pedersen, John

    2002-08-01

    The Ministry of Environment and Energy requested ELSAM and ELTRA to establish an offshore wind farm with an output of 150 MW in the waters of Horns Rev, approximately 15 km off Blaevandshuk, which is the most westerly point of Denmark. The first phase of construction of the wind farm have started in spring 2002. Before the construction activities take place, a baseline description of the benthos has been conducted as a part of an environmental monitoring programme for the introduction of hard bottom substrates in the North Sea. The establishment of a monitoring programme is required according to some environmental guidelines for offshore wind farms prepared by the Danish Energy Agency. The monitoring programme established for the benthic infauna was performed in spring 2001. In addition to a proposed fish investigation programme concerning the stomach contents of fish a comparative programme on benthos was established as part of the monitoring programme. The benthos sampling in connection with the fish programme was conducted in autumn 2001. This benthic survey includes sampling in a proposed reference area for the fish surveys north east of the wind farm. This report presents the data of the baseline environmental survey of the seabed in the wind farm site and in the proposed reference site and a brief description of the weather conditions at the time of sampling. (au)

  17. Horns Rev offshore wind farm. Introducing hard bottom substrate sea bottom and marine biology. Data report 2001

    Energy Technology Data Exchange (ETDEWEB)

    Leonhard, S.B.; Pedersen, John

    2002-08-15

    The Ministry of Environment and Energy requested ELSAM and ELTRA to establish an offshore wind farm with an output of 150 MW in the waters of Horns Rev, approximately 15 km off Blaevandshuk, which is the most westerly point of Denmark. The first phase of construction of the wind farm have started in spring 2002. Before the construction activities take place, a baseline description of the benthos has been conducted as a part of an environmental monitoring programme for the introduction of hard bottom substrates in the North Sea. The establishment of a monitoring programme is required according to some environmental guidelines for offshore wind farms prepared by the Danish Energy Agency. The monitoring programme established for the benthic infauna was performed in spring 2001. In addition to a proposed fish investigation programme concerning the stomach contents of fish a comparative programme on benthos was established as part of the monitoring programme. The benthos sampling in connection with the fish programme was conducted in autumn 2001. This benthic survey includes sampling in a proposed reference area for the fish surveys north east of the wind farm. This report presents the data of the baseline environmental survey of the seabed in the wind farm site and in the proposed reference site and a brief description of the weather conditions at the time of sampling. (au)

  18. Policy intersections: Strengthening bottom up accountability amidst ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    It also aims to strengthen strategic alliances through the West African Convergence of Land and Water Struggles to secure community land rights, particularly women's ... IDRC is supporting research that studies the most effective ways to empower women, prevent gender-based violence, and make digital platforms work for ...

  19. A preliminary study on the occurrence of Dermatophyles and other keratinophilic fungi in bottom sediments of rivers and lakes

    Directory of Open Access Journals (Sweden)

    Krzysztof Ulfig

    2014-08-01

    Full Text Available Sam pies of bottom sediments from the Rivers Nacyna, Ruda and from an eutrophic reservoir holding cooling waters were examined for dermatophytes and correlated fungi. The species isolated were: Trichophyton terrestre complex, T. ajelloi (and its perfect form Anhroderma uncinatum. pathogenic strains of T. mentagrophytes and Microsporum cookei; also isolated were five species of the genus Chrysosporium.

  20. Strong WW Interaction at LHC

    Energy Technology Data Exchange (ETDEWEB)

    Pelaez, Jose R

    1998-12-14

    We present a brief pedagogical introduction to the Effective Electroweak Chiral Lagrangians, which provide a model independent description of the WW interactions in the strong regime. When it is complemented with some unitarization or a dispersive approach, this formalism allows the study of the general strong scenario expected at the LHC, including resonances.

  1. Transfer of radiocaesium from contaminated bottom sediments to marine organisms through benthic food chains in post-Fukushima and post-Chernobyl periods

    Science.gov (United States)

    Bezhenar, Roman; Jung, Kyung Tae; Maderich, Vladimir; Willemsen, Stefan; de With, Govert; Qiao, Fangli

    2016-05-01

    ) is close to the observed decrease constant in sediments (0.44 yr-1). These results strongly indicate that the gradual decrease of activity in demersal fish (decrease constant is 0.46 yr-1) is caused by the transfer of activity from organic matter deposited in bottom sediment through the deposit-feeding invertebrates. The estimated model transfer coefficient from bulk sediment to demersal fish in the model for 2012-2020 (0.13) is larger than that to the deposit-feeding invertebrates (0.07). In addition, the transfer of 137Cs through food webs for the period of 1945-2020 has been modelled for the Baltic Sea contaminated due to global fallout and from the Chernobyl accident. The model simulation results obtained with generic parameters are also in good agreement with available measurements in the Baltic Sea. Unlike the open coastal system where the FDNPP is located, the dynamics of radionuclide transfer in the Baltic Sea reach a quasi-steady state due to the slow rate in water mass exchange in this semi-enclosed basin. Obtained results indicate a substantial contribution of the benthic food chain in the long-term transfer of 137Cs from contaminated bottom sediments to marine organisms and the potential application of a generic model in different regions of the world's oceans.

  2. Transfer of radiocaesium from contaminated bottom sediments to marine organisms through benthic food chains in post-Fukushima and post-Chernobyl periods

    Energy Technology Data Exchange (ETDEWEB)

    Bezhenar, Roman; Maderich, Vladimir [Institute of Mathematical Machine and System Problems, Kiev (Ukraine); Jung, Kyung Tae [Korea Institute of Ocean Science and Technology, Ansan (Korea, Republic of); Willemsen, Stefan; With, Govert de [NRG, Arnhem (Netherlands); Qiao, Fangli [First Institute of Oceanography, Qingdao (China)

    2016-07-01

    -feeding invertebrates (0.45 yr{sup -1}) is close to the observed decrease constant in sediments (0.44 yr{sup -1}). These results strongly indicate that the gradual decrease of activity in demersal fish (decrease constant is 0.46 yr{sup -1}) is caused by the transfer of activity from organic matter deposited in bottom sediment through the deposit-feeding invertebrates. The estimated model transfer coefficient from bulk sediment to demersal fish in the model for 2012-2020 (0.13) is larger than that to the deposit-feeding invertebrates (0.07). In addition, the transfer of {sup 137}Cs through food webs for the period of 1945-2020 has been modelled for the Baltic Sea contaminated due to global fallout and from the Chernobyl accident. The model simulation results obtained with generic parameters are also in good agreement with available measurements in the Baltic Sea. Unlike the open coastal system where the FDNPP is located, the dynamics of radionuclide transfer in the Baltic Sea reach a quasi-steady state due to the slow rate in water mass exchange in this semi-enclosed basin. Obtained results indicate a substantial contribution of the benthic food chain in the long-term transfer of {sup 137}Cs from contaminated bottom sediments to marine organisms and the potential application of a generic model in different regions of the world's oceans.

  3. Abundance of plankton population densities in relation to bottom soil textural types in aquaculture ponds

    Directory of Open Access Journals (Sweden)

    F. Siddika

    2012-06-01

    Full Text Available Plankton is an important food item of fishes and indicator for the productivity of a water body. The present study was conducted to evaluate the effects of bottom soil textural conditions on abundance of plankton in aquaculture pond. The experiment was carried out using three treatments, i.e., ponds bottom with sandy loam (T1, with loam (T2 and with clay loam (T3. The ranges of water quality parameters analyzed were suitable for the growth of plankton during the experimental period. Similarly, chemical properties of soil were also within suitable ranges and every parameter showed higher ranges in T2. A total 20 genera of phytoplankton were recorded belonged to Chlorophyceae (7, Cyanophyceae (5, Bacillariophyceae (5, Euglenophyceae (2 and Dinophyceae (1. On the other hand, total 13 genera of zooplankton were recorded belonged to Crustacea (7 and Rotifera (6. The highest ranges of phytoplankton and zooplankton densities were found in T2 where low to medium-type bloom was observed during the study period. Consequently, the mean abundance of plankton (phytoplankton and zooplankton density was significantly highest in T2. The highest abundance of plankton in the T2 indicated that pond bottom with loamy soil is suitable for the growth and production of plankton in aquaculture ponds.

  4. Bottom Ash Waste Used in Different Construction Materials

    Science.gov (United States)

    Volokitin, G. G.; Skripnikova, N. K.; Volokitin, O. G.; Lutsenko, A. V.; Shekhovtsov, V. V.; Litvinova, V. A.; Semenovykh, M. A.

    2017-04-01

    The paper presents the investigations of the composition and properties of the bottom ash waste generated by Seversk thermal power plant of the Tomsk region. The compositions suggested for construction materials (fired and hydrothermal) are based on the bottom ash waste. Mechanical-and-physical and physicochemical properties of the produced specimens are investigated in this paper. Phase compositions are determined for fired materials based on the bottom ash waste, and a possibility of producing ash-based mineral wool is defined herein. The produced ash-containing fiber possesses a higher chemical resistance and performance characteristics due to its higher acidity index.

  5. Propagation of bottom-trapped waves over variable topography

    Digital Repository Service at National Institute of Oceanography (India)

    Shetye, S.R.

    on a topographic slope, as they propagate towards a deeper region of constant depth, is examined using a quasi-geostrophic model. It is seen that there can be no free transmitted wave to the region of constant depth. The bottom-trapped energy is thus... currents farther away. 1. INTRODUCTION Rhines (1970) showed that a stratified rotating fluid over sloping bottom topography can support free waves that are bottom-intensified. The in- crease in the kinetic energy of the currents with depth...

  6. Multileptons and the structure of weak decays of bottom mesons

    International Nuclear Information System (INIS)

    Branco, G.C.; Nilles, H.P.

    1978-06-01

    We present a model independent analysis of bottom quark weak interactions. In particular, we show how a study of multi-lepton events in e + e - annihilation can provide evidence for bottom particle production, and determine all the parameters of the decay such as (1) relative strength of ΔC = 1 and ΔC = 0 transitions (2) semi-leptonic branching ratio (3) amount of mixing (4) possible existence of flavour-changing neutral currents. Furthermore it is shown how three and four electron events from bottom decays can be used to obtain indirect evidence for the top quark. (orig.) [de

  7. Bottom-up Initiatives for Photovoltaic: Incentives and Barriers

    Directory of Open Access Journals (Sweden)

    Kathrin Reinsberger

    2014-06-01

    Full Text Available When facing the challenge of restructuring the energy system, bottom-up initiatives can aid the diffusion of decentralized and clean energy technologies. We focused here on a bottom-up initiative of citizen-funded and citizen-operated photovoltaic power plants. The project follows a case study-based approach and examines two different community initiatives. The aim is to investigate the potential incentives and barriers relating to participation or non-participation in predefined community PV projects. Qualitative, as well as quantitative empirical research was used to examine the key factors in the further development of bottom-up initiatives as contributors to a general energy transition.

  8. Strong-back safety latch

    International Nuclear Information System (INIS)

    DeSantis, G.N.

    1995-01-01

    The calculation decides the integrity of the safety latch that will hold the strong-back to the pump during lifting. The safety latch will be welded to the strong-back and will latch to a 1.5-in. dia cantilever rod welded to the pump baseplate. The static and dynamic analysis shows that the safety latch will hold the strong-back to the pump if the friction clamps fail and the pump become free from the strong-back. Thus, the safety latch will meet the requirements of the Lifting and Rigging Manual for under the hook lifting for static loading; it can withstand shock loads from the strong-back falling 0.25 inch

  9. Strong-back safety latch

    Energy Technology Data Exchange (ETDEWEB)

    DeSantis, G.N.

    1995-03-06

    The calculation decides the integrity of the safety latch that will hold the strong-back to the pump during lifting. The safety latch will be welded to the strong-back and will latch to a 1.5-in. dia cantilever rod welded to the pump baseplate. The static and dynamic analysis shows that the safety latch will hold the strong-back to the pump if the friction clamps fail and the pump become free from the strong-back. Thus, the safety latch will meet the requirements of the Lifting and Rigging Manual for under the hook lifting for static loading; it can withstand shock loads from the strong-back falling 0.25 inch.

  10. Evaluating the mutagenicity of leachates obtained from the bottom ash of a municipal solid waste incinerator by using a Salmonella reverse mutation assay.

    Science.gov (United States)

    Chen, Po-Wen; Liu, Zhen-Shu; Wun, Min-Jie; Ran, Cai-Ling

    2015-04-01

    The mutagenic potential of leachates derived from the bottom ash of a municipal solid waste incinerator in Taiwan were evaluated using an Ames Salmonella mutagenicity assay with three standard tester strains, TA98, TA100, and TA1535. Three types of leachants, leachant A (pH 4.93), leachant B (pH 2.88), and leachant C (deionized water, pH 6.0), were carried out according to toxicity characteristic leaching procedure (TCLP). Moreover, two types of bottom ash, nonsieved and sieved bottom ash (particle size bottom ash were all below the limits set by Taiwanese regulations. However, leachate A from nonsieved and bottom ash showed mutagenicity. Moreover, leachate A from bottom ash displayed stronger mutagenicity than that from nonsieved ash. The leachate A from bottom ash, that were diluted by 100-fold showed no mutagenicity. In conclusion, our results suggested that the chemical composition and mutagenic potential of leachates should be monitored to evaluate the safety of bottom ash. Copyright © 2014 Elsevier Ltd. All rights reserved.

  11. Synthesis of Zeolite-X from Bottom Ash for H2 Adsorption

    Science.gov (United States)

    Kurniawan, R. Y.; Romadiansyah, T. Q.; Tsamarah, A. D.; Widiastuti, N.

    2018-01-01

    Zeolite-X was synthesized from bottom ash power plant waste using fusion method on air atmosphere. The fused product dissolved in demineralized water and aluminate solution was added to adjust the SiO2/Al2O3 molar ratio gel prior hydrothermal process. The synthesis results were characterized using X-Ray Diffraction (XRD), Scanning Electron Microscope (SEM), and Fourier Transform Infrared (FTIR). The results showed that the zeolite-X has a high crystallinity with octahedral particle. The pure-form zeolite-X then was characterized and tested for H2 gas adsorption by gravimetric method to determine the H2 gas adsorption capacity of zeolite-X from bottom ash and it was compared to synthetic zeolite-X.

  12. DISTRIBUTION OF HYDROCARBONS IN PARTICULATE MATTER AND BOTTOM SEDIMENTS OF THE VOLGA DELTA

    Directory of Open Access Journals (Sweden)

    Inna Nemirovskaya

    2010-01-01

    Full Text Available Data are presented on the content and composition of hydrocarbons (aliphatic and polyaromatic in the filtered particulate matter and in the surface layer of the bottom sediments of the Volga River and the northern shelf of the Caspian Sea. Because of transformation and precipitation of anthropogenic and natural compounds, the HC composition in particulate matter and bottom sediments undergoes changes caused by precipitation of particulate matter, varying temperatures, and mixing of fresh and saline waters. It appeared that the greatest accumulation of the HC proceeds in the region of avalanche sedimentation, and their content is independent of the grain-size type of the sediments. The anthropogenic HC (oil and pyrogenous do not pass the marginal filter of the Volga River and do not enter the open part of the sea.

  13. Assessing and mitigating of bottom trawling. Final BENTHIS project Report (Benthic Ecosystem Fisheries Impact Study)

    DEFF Research Database (Denmark)

    Rijnsdorp, Adriaan D; Eigaard, Ole Ritzau; Kenny, Andrew

    2017-01-01

    the fuel cost without affecting the catch rate of the target species. Replacing mechanical stimulation by tickler chains with electrical stimulation In the beam trawl fishery for sole, reduced footprint and penetration depth as well as the fuel cost. Electrical stimulation is also a promising innovation...... to reduce the bycatch and bottom contact in the beam trawl fishery for brown shrimps. Sea trials to replace bottom trawls with pots were inconclusive. Results suggest that creels may offer an alternative for small Nephrops fishers in the Kattegat. In waters off Greece, the catch rates were very low. Sea...... trials with the blue mussel fishery showed that fishers could reduce their footprint by deploying acoustic equipment to detect mussel concentrations that allow the fishers to more precisely target the mussel beds and hence reduce fishing in areas with low mussel density. A review of the various case...

  14. Estuarine circulation reversals and related rapid changes in winter near-bottom oxygen conditions in the Gulf of Finland, Baltic Sea

    Directory of Open Access Journals (Sweden)

    T. Liblik

    2013-10-01

    Full Text Available The reversal of estuarine circulation caused by southwesterly wind forcing may lead to vanishing of stratification and subsequently to oxygenation of deep layers during the winter in the Gulf of Finland. Six conductivity, temperature, depth (CTD+oxygen transects (130 km long, 10 stations were conducted along the thalweg from the western boundary to the central gulf (21 December 2011–8 May 2012. Two bottom-mounted ADCP were installed, one near the western border and the second in the central gulf. A CTD with a dissolved oxygen sensor was deployed close to the western ADCP. Periods of typical estuarine circulation were characterized by strong stratification, high salinity, hypoxic conditions and inflow to the gulf in the near-bottom layer. Two circulation reversals were observed: one in December–January and one in February. The first reversal event was well developed; it caused the disappearance of the stratification and an increase in the oxygen concentration from hypoxic values to 270 μmol L−1 (to 6 mL L−1 throughout the water column along the thalweg and lasted approximately 1.5 months. Shifts from estuarine circulation to reversed circulation and vice versa were both associated with strong longitudinal (east–west gulf currents (up to 40 cm s−1 in the deep layer. The change from oxygenated to hypoxic conditions in the western near-entrance area of the gulf occurred very rapidly, within less than a day, due to the intrusion of the hypoxic salt wedge from the NE Baltic Proper. In the eastern part of the gulf, good oxygen conditions caused by reversals remained for a few months.

  15. Titanium: light, strong, and white

    Science.gov (United States)

    Woodruff, Laurel; Bedinger, George

    2013-01-01

    Titanium (Ti) is a strong silver-gray metal that is highly resistant to corrosion and is chemically inert. It is as strong as steel but 45 percent lighter, and it is twice as strong as aluminum but only 60 percent heavier. Titanium dioxide (TiO2) has a very high refractive index, which means that it has high light-scattering ability. As a result, TiO2 imparts whiteness, opacity, and brightness to many products. ...Because of the unique physical properties of titanium metal and the whiteness provided by TiO2, titanium is now used widely in modern industrial societies.

  16. NEFSC 2003 Spring Bottom Trawl Survey (DE0303, EK500)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NEFSC bottom trawl survey is a fisheries independent, multi-species survey that provides the primary scientific data for fisheries assessments in the U.S....

  17. Aluminium alloys in municipal solid waste incineration bottom ash.

    Science.gov (United States)

    Hu, Yanjun; Rem, Peter

    2009-05-01

    With the increasing growth of incineration of household waste, more and more aluminium is retained in municipal solid waste incinerator bottom ash. Therefore recycling of aluminium from bottom ash becomes increasingly important. Previous research suggests that aluminium from different sources is found in different size fractions resulting in different recycling rates. The purpose of this study was to develop analytical and sampling techniques to measure the particle size distribution of individual alloys in bottom ash. In particular, cast aluminium alloys were investigated. Based on the particle size distribution it was computed how well these alloys were recovered in a typical state-of-the-art treatment plant. Assessment of the cast alloy distribution was carried out by wet physical separation processes, as well as chemical methods, X-ray fluorescence analysis and electron microprobe analysis. The results from laboratory analyses showed that cast alloys tend to concentrate in the coarser fractions and therefore are better recovered in bottom ash treatment plants.

  18. NEFSC 1999 Fall Bottom Trawl Survey (AL9911, EK500)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NEFSC bottom trawl survey is a fisheries independent, multi-species survey that provides the primary scientific data for fisheries assessments in the U.S....

  19. NEFSC 2005 Spring Bottom Trawl Survey (AL0504, EK500)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NEFSC bottom trawl survey is a fisheries independent, multi-species survey that provides the primary scientific data for fisheries assessments in the U.S....

  20. NEFSC 2003 Fall Bottom Trawl Survey (AL0305, EK500)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NEFSC bottom trawl survey is a fisheries independent, multi-species survey that provides the primary scientific data for fisheries assessments in the U.S....