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Sample records for drainage polluted subtropical

  1. Ion activity and distribution of heavy metals in acid mine drainage polluted subtropical soils

    International Nuclear Information System (INIS)

    Li Yongtao; Becquer, Thierry; Dai Jun; Quantin, Cecile; Benedetti, Marc F.

    2009-01-01

    The oxidative dissolution of mine wastes gives rise to acidic, metal-enriched mine drainage (AMD) and has typically posed an additional risk to the environment. The poly-metallic mine Dabaoshan in South China is an excellent test site to understand the processes affecting the surrounding polluted agricultural fields. Our objectives were firstly to investigate metal ion activity in soil solution, distribution in solid constituents, and spatial distribution in samples, secondly to determine dominant environment factors controlling metal activity in the long-term AMD-polluted subtropical soils. Soil Column Donnan Membrane Technology (SC-DMT) combined with sequential extraction shows that unusually large proportion of the metal ions are present as free ion in the soil solutions. The narrow range of low pH values prevents any pH effects during the binding onto oxides or organic matter. The differences in speciation of the soil solutions may explain the different soil degradation observed between paddy and non-paddy soils. - First evidence of the real free metal ion concentrations in acid mine drainage context in tropical systems

  2. Plastic pollution in the South Pacific subtropical gyre.

    Science.gov (United States)

    Eriksen, Marcus; Maximenko, Nikolai; Thiel, Martin; Cummins, Anna; Lattin, Gwen; Wilson, Stiv; Hafner, Jan; Zellers, Ann; Rifman, Samuel

    2013-03-15

    Plastic marine pollution in the open ocean of the southern hemisphere is largely undocumented. Here, we report the result of a (4489 km) 2424 nautical mile transect through the South Pacific subtropical gyre, carried out in March-April 2011. Neuston samples were collected at 48 sites, averaging 50 nautical miles apart, using a manta trawl lined with a 333 μm mesh. The transect bisected a predicted accumulation zone associated with the convergence of surface currents, driven by local winds. The results show an increase in surface abundance of plastic pollution as we neared the center and decrease as we moved away, verifying the presence of a garbage patch. The average abundance and mass was 26,898 particles km(-2) and 70.96 g km(-2), respectively. 88.8% of the plastic pollution was found in the middle third of the samples with the highest value of 396,342 particles km(-2) occurring near the center of the predicted accumulation zone. Copyright © 2013 Elsevier Ltd. All rights reserved.

  3. The impact of anthropogenic pollution on limnological characteristics of a subtropical highland reservoir “Lago de Guadalupe”, Mexico

    Directory of Open Access Journals (Sweden)

    Sepulveda-Jauregui A.

    2013-08-01

    Full Text Available “Lago de Guadalupe” is an important freshwater ecosystem located in the northern part of the metropolitan area surrounding Mexico City, under high demographic pressure. It receives approximately 15 hm3·y-1 of untreated municipal wastewater from the surrounding municipalities. In order to develop a comparative assessment of the pollution effect over the limnological characteristics of Lago de Guadalupe, this lake was characterised from February 2006 to July 2009, and the results were compared with those obtained from a non-polluted lake “Lago el Llano” located in the same drainage area. Lago de Guadalupe was hypereutrophic with anoxic conditions throughout most of the water column. In contrast, Lago el Llano was mesotrophic with high dissolved oxygen concentrations throughout the entire water column with a clinograde profile. Both reservoirs had a monomictic mixing regime. The longitudinal zonation of physicochemical and biological variables were investigated in order to better understand the processes controlling the water quality across the reservoir during its residence time. This study shows the impact of anthropogenic pollution on the limnological characteristics of a subtropical reservoir and confirms that under adequate management schemes, namely avoiding pollution and wastewater discharges, subtropical reservoirs can be prevented from developing eutrophic conditions.

  4. Pollution of Indus water and the drainage system of Sindh

    International Nuclear Information System (INIS)

    Sohaq, M.A.; Mahessar, A.A.; Bohio, I.A.

    2005-01-01

    Adequate supply of fresh and clean drinking water is basic need for all human beings on the earth yet it has been observed that millions of people worldwide are deprived of this essential facility. Freshwater resources all over the world are being threatened not only by over-exploitation and poor management but also by ecological degradation. The main sources of freshwater pollution can be attributed to discharge of untreated waste, dumping of industrial effluent, and run-off from agricultural fields. Industrial growth, urbanization and the increasing use of synthetic organic substances have serious and adverse impacts on fresh water bodies. Piles of garbage and fouling of air and water resources are one of the most common sights in Pakistan. These are, in fact, one of the consequences of the process of rapid urbanization, coupled with increased industrialization that country is witness. It goes doubt that environmental deterioration is a natural outcome of rapid population growth, increase in agricultural practices, industrialization, mechanization and mobilization of society. River Indus and drainage system of the Sindh province nowadays are facing severe problem of industrial pollution by the discharge of untreated effluent of different industries. In that context, several field surveys of sugar industries located in interior Sindh and pharmaceutical Company, Jamshoro, were carried out to asses the quality and quantity of pollution. (author)

  5. The application of lichens as ecological surrogates of air pollution in the subtropics: a case study in South Brazil.

    Science.gov (United States)

    Koch, Natália M; Branquinho, Cristina; Matos, Paula; Pinho, Pedro; Lucheta, Fabiane; Martins, Suzana M A; Vargas, Vera M F

    2016-10-01

    The use of lichens as ecological surrogates has been an important tool to evaluate the impact of air pollution in both ecosystem and human health but remains underused in the subtropics due to lack of knowledge. Aiming to support the application of lichen as ecological surrogates of the effects of air pollution in the subtropics, we hypothesized that urbanization was an important driver of changes on lichen diversity, composition, and vitality. For that, we quantified several lichen diversity metrics (richness, cover, and community composition) and photobiont vitality in relation to atmospheric pollution or its surrogates (modeled pollutant gases, pollutants in lichen thallus, and land cover). We confirmed that air pollution was a key driver for lichen diversity. Changes in lichen community composition and vitality were very significantly related to air pollution and integrated the effect of multiple stressors (particulate matter, NOx, and Cu), thus being powerful ecological indicators of air pollution in the subtropics.

  6. Progress on Phytoremediation of Drainage Water N and P Pollution in Farmland Drainage Ditches:A Review

    Directory of Open Access Journals (Sweden)

    LUO Liang-guo

    2016-01-01

    Full Text Available Water pollution is a main issue that contributes to the water quality-induced shortage of global water resources. After cleaner production technology successfully applied to the industrial pollution control, agricultural non-point source pollution has been the biggest contributor to water pollution, in particular, the leading source of excess nitrogen and phosphorus in surface water and gaining more attention. The phytoremediation technology has been gradually applied to improve surface water quality because of the advantages in its insitu remediation and no secondary pollution. This paper summarized the progress made on the main approaches, influencing factors and issues of removing N and P in farmland drainage water using phytoremediation. Recommendations regarding to the future research in strengthening plant combination, its economic and social efficiencies, and the implementation from small scale demonstration to large scale extension will be proposed. It would further support improving the effect of agricultural nonpoint source pollution control.

  7. Acid mine drainage: mining and water pollution issues in British Columbia

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-12-31

    The importance of protecting water quality and some of the problems associated with mineral development are described. Negative impacts of mining operations such as sedimentation, water disturbances, and water pollution from waste rock and tailings are considered. Mining wastes, types of water pollution from mining, the legacy of acid mine drainage, predicting acid mine drainage, preventing and mitigating acid mine drainage, examples from the past, and cyanide heap-leaching are discussed. The real costs of mining at the Telkwa open pit coal mine are assessed. British Columbia mines that are known for or are potentially acid generating are shown on a map. 32 refs., 10 figs.

  8. Direct versus indirect electrochemical oxidation of pesticide polluted drainage water containing sodium chloride

    DEFF Research Database (Denmark)

    Muff, Jens; Erichsen, Rasmus; Damgaard, Christian

    2008-01-01

    concentrations. Analyses of the actual pollutants, Me-Parathion, parathion, malathion and degradation products, confirmed that the concentrations of all initial pollutants were eliminated during the treatment. The only exception was O,O,O-triethyl-phosphoric acid, a degradation product which was formed during...... the treatment. Indirect electrochemical treatment, where a highly oxidized brine solution was added to the drainage water, revealed immediately reduction in COD, and similar to the direct treatment, degradation of all of the pesticide pollutants was obtained except for the O,O,O-triethyl-phosphoric acid...... contribute to the degradation. Experiments with addition of aqueous sodium hypochlorite solution to the drainage water revealed that hypochlorite was the main oxidizing agent responsible for the indirect oxidation. The experimentally obtained results for the pesticide degradation were compared to theoretic...

  9. Direct versus indirect electrochemical oxidation of pesticide polluted drainage water containing sodium chloride

    DEFF Research Database (Denmark)

    Muff, Jens; Erichsen, Rasmus; Damgaard, Christian

    2008-01-01

    Drainage water from a depot of chemical waste, polluted with a mixture of organophosphates and degradation products was treated by a direct as well as an indirect electrochemical method using a Ti/Pt-Ir anode and Stainless Steel 304 cathode. With a concentration of 0.7%, sodium chloride was the m......Drainage water from a depot of chemical waste, polluted with a mixture of organophosphates and degradation products was treated by a direct as well as an indirect electrochemical method using a Ti/Pt-Ir anode and Stainless Steel 304 cathode. With a concentration of 0.7%, sodium chloride...... the treatment. Indirect electrochemical treatment, where a highly oxidized brine solution was added to the drainage water, revealed immediately reduction in COD, and similar to the direct treatment, degradation of all of the pesticide pollutants was obtained except for the O,O,O-triethyl-phosphoric acid....... The experiments proved that the obtained degradation of pesticide solely was caused by indirect electrochemical oxidation, mainly due to the electrolytic formation of hypochlorite during the treatment, and that direct electron transfer from the pesticide substances at the anode surface didn't significantly...

  10. The impact of episodic coal mine drainage pollution on benthic macroinvertebrates in streams in the Anthracite region of Pennsylvania

    International Nuclear Information System (INIS)

    MacCausland, A.; McTammany, M.E.

    2007-01-01

    Episodic coal mine drainage, caused by fluctuations in mine discharges relative to stream flow, has devastating effects on aquatic macroinvertebrate communities. Seven stream reaches in the Anthracite region of Pennsylvania were identified as chronically, episodically or not impaired by mine drainage, and sampled seasonally for 1 year to determine the effect of episodic mine drainage on macroinvertebrates. Specific conductance fluctuated seasonally in episodic sites; it was lower in winter when discharge increased and higher in summer when discharges decreased and mine drainage made up a larger proportion of stream flow. Although we hypothesized that episodic streams would have higher macroinvertebrate richness than chronic streams, comparisons showed no differences in richness between treatments. Episodic pollution may result from undersized or poorly maintained passive treatment systems; therefore, intensive macroinvertebrate monitoring may be needed to identify streams being affected by episodic mine drainage because macroinvertebrate richness may be sensitive to water quality fluctuations. - Episodic coal mine pollution decreases benthic macroinvertebrate richness and density

  11. Assessment of Pollutant Removal Efficiency and Drainage Capacity in Stormwater Biofilters

    Science.gov (United States)

    Carroll, S. J.; Mills, H.; Reagan, A.; Triassi, M.; Bauer, S.; Matiasek, S. J.; Libby, R.; Meddings, C.

    2016-12-01

    Urban stormwater runoff contributes to flooding and impacts water quality with increased sediment and pollutant loads. Biofilters are vegetated filtration systems designed to mitigate stormwater by enhancing infiltration, sedimentation, contaminant sorption and uptake. Despite the rapid implementation of biofilters as stormwater management solutions, their performance is mainly evaluated in terms of flood reduction while their pollutant removal efficiency is rarely assessed. We investigated the effect of biofilter composition on drainage capacity and individual pollutant removal in test columns. Triplicate columns consisted of layers of pebbles, fine sand, filtration mix (test variable), mulch, lava rock and Santa Barbara sedges. The filtration mix was one of five combinations of coarse sand and local loam soil ranging from 100% sand to 100% soil. Consistent with differences in pore size distribution, hydraulic conductivity values were lowest in 100% soil biofilters (3.0 ± 0.6 mm/h) and highest in the 100% sand biofilters (22.7 ± 4.2 mm/h). A synthetic mixture of nutrients, metals, and salts in proportions representative of stormwater composition was applied to the test columns. Biofilters removed over 98% of dissolved copper, nickel, and zinc, and at least 67% of dissolved lead, even when applying synthetic runoff with metal concentrations three orders of magnitude larger than in actual stormwater. In addition, biofilters oxygenated, neutralized, and decreased the turbidity of stormwater. Ammonium was quantitatively removed from synthetic runoff (97-100%), while nitrate and phosphate were poorly retained (48-64%) or even leached from sand biofilters. This study demonstrated that, while decreasing drainage capacity, adding even a small proportion of native soil to the filtration media significantly increases pollutant removal of biofilters. With proper consideration of the filtration mixture, biofiltration systems can effectively remediate urban stormwater.

  12. Biodiversity of zoosporic fungi in polluted water drainages across Niles’Delta region, Lower Egipt

    Directory of Open Access Journals (Sweden)

    Esam H. Ali

    2013-12-01

    Full Text Available Thirty-four identified in addition to five unidentified species appertaining to ten genera of zoosporic fungi were identified and isolated from eighty four polluted water samples, which were randomly collected from different polluted sites of the water drainages along the Niles Delta in Lower Egypt. Baiting sesame seeds culture technique was employed at 20±2º C for the recovery of zoosporic fungi. The genera; Pythium and Saprolegnia (8 and 7 zoosporic fungal species, respectively showed the broadest spectra of species diversity whereas Aqualinderella was only represented by one species (A. fermentans. Saprolegnia delica and Dictyuchus carpophorus (the greatest fungal populations were the most dominant isolated zoosporic fungal species where they were highly occurred especially at the hyper-polluted waters with the heavy metals. These two species could be considered as indicators for the response of the structure and function of microbial communities for water pollution. Several zoosporic fungal species were rarely encountered. Both Aqualinderella fermentans and Pythium rostratum were recovered in moderate frequency of occurrence. Water samples which had high concentrations in heavy metals were the poorest in the species diversity of zoosporic fungi. Despite that, fungal species belonging to the family Saprolegniaceae flourished in hyper polluted water samples whilst those belonging to the family Pythiaceae predominated in more diluted water samples. Also, the prevalent species; S. delica and D. carpophorus were not affected by heavy metals concentrations being as indicators for water pollution with the heavy metals. pH values of the polluted water samples had no influence on the occurrence of zoosporic fungi. Water samples characterized by high organic matter content and low total soluble salts were the richest in zoosporic fungal species.

  13. Study of environmental pollution and mineralogical characterization of sediment rivers from Brazilian coal mining acid drainage

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Luis F.O., E-mail: felipeqma@hotmail.com [Environmental Science and Nanotechnology Department, Institute of Environmental Research and Human Development – IPADH, Capivari de Baixo, Santa Catarina (Brazil); Laboratory of Environmental Researches and Nanotechnology Development, Centro Universitário La Salle, Victor Barreto, 2288 Centro 92010-000, Canoas, RS (Brazil); Fdez- Ortiz de Vallejuelo, Silvia; Martinez-Arkarazo, Irantzu; Castro, Kepa [Department of Analytical Chemistry, University of the Basque Country (EHU/UPV), P.O. Box 644, 48080 Bilbao, Basque Country (Spain); Oliveira, Marcos L.S. [Environmental Science and Nanotechnology Department, Institute of Environmental Research and Human Development – IPADH, Capivari de Baixo, Santa Catarina (Brazil); Sampaio, Carlos H.; Brum, Irineu A.S. de [Universidade Federal do Rio Grande do Sul, Escola de Engenharia, Departamento de Metalurgia, Centro de Tecnologia, Av. Bento Gonçalves, 9500, Bairro Agronomia, CEP: 91501-970, Porto Alegre, RS (Brazil); Leão, Felipe B. de; Taffarel, Silvio R. [Laboratory of Environmental Researches and Nanotechnology Development, Centro Universitário La Salle, Victor Barreto, 2288 Centro 92010-000, Canoas, RS (Brazil); Madariaga, Juan M. [Department of Analytical Chemistry, University of the Basque Country (EHU/UPV), P.O. Box 644, 48080 Bilbao, Basque Country (Spain)

    2013-03-01

    Acid drainage from coal mines and metal mining is a major source of underground and surface water contamination in the world. The coal mining acid drainage (CMAD) from mine contains large amount of solids in suspension and a high content of sulphate and dissolved metals (Al, Mn, Zn, Cu, Pb, Fe, etc.) that finally are deposited in the rivers. Since this problem can persist for centuries after mine abandonment, it is necessary to apply multidisciplinary methods to determine the potential risk in a determinate area. These multidisciplinary methods must include molecular and elemental analysis and finally all information must be studied statistically. This methodology was used in the case of coal mining acid drainage from the Tubarao River (Santa Catarina, Brazil). During molecular analysis, Raman Spectroscopy, electron bean, and X-ray diffraction (XRD) have been proven very useful for the study of minerals present in sediment rivers near this CMAD. The obtained spectra allow the precise identification of the minerals as jarosite, quartz, clays, etc. The elemental analysis (Al, As, Fe, K, Na, Ba, Mg, Mn, Ti, V, Zn, Ag, Co, Li, Mo, Ni, Se, Sn, W, B, Cr, Cu, Pb and Sr) was realised by inductively coupled plasma mass spectrometry (ICP-MS). Statistical analysis (Principal Component Analysis) of these dates of concentration reveals the existence of different groups of samples with specific pollution profiles in different areas of the Tubarao River. Highlights: ► Increasing coal drainage sediments geochemical information will increase human health information in this area. ► Brazilian coal mining information will increase recuperation planning information. ► The nanominerals showed strong sorption ability to aqueous hazardous elements.

  14. Study of environmental pollution and mineralogical characterization of sediment rivers from Brazilian coal mining acid drainage

    International Nuclear Information System (INIS)

    Silva, Luis F.O.; Fdez- Ortiz de Vallejuelo, Silvia; Martinez-Arkarazo, Irantzu; Castro, Kepa; Oliveira, Marcos L.S.; Sampaio, Carlos H.; Brum, Irineu A.S. de; Leão, Felipe B. de; Taffarel, Silvio R.; Madariaga, Juan M.

    2013-01-01

    Acid drainage from coal mines and metal mining is a major source of underground and surface water contamination in the world. The coal mining acid drainage (CMAD) from mine contains large amount of solids in suspension and a high content of sulphate and dissolved metals (Al, Mn, Zn, Cu, Pb, Fe, etc.) that finally are deposited in the rivers. Since this problem can persist for centuries after mine abandonment, it is necessary to apply multidisciplinary methods to determine the potential risk in a determinate area. These multidisciplinary methods must include molecular and elemental analysis and finally all information must be studied statistically. This methodology was used in the case of coal mining acid drainage from the Tubarao River (Santa Catarina, Brazil). During molecular analysis, Raman Spectroscopy, electron bean, and X-ray diffraction (XRD) have been proven very useful for the study of minerals present in sediment rivers near this CMAD. The obtained spectra allow the precise identification of the minerals as jarosite, quartz, clays, etc. The elemental analysis (Al, As, Fe, K, Na, Ba, Mg, Mn, Ti, V, Zn, Ag, Co, Li, Mo, Ni, Se, Sn, W, B, Cr, Cu, Pb and Sr) was realised by inductively coupled plasma mass spectrometry (ICP-MS). Statistical analysis (Principal Component Analysis) of these dates of concentration reveals the existence of different groups of samples with specific pollution profiles in different areas of the Tubarao River. Highlights: ► Increasing coal drainage sediments geochemical information will increase human health information in this area. ► Brazilian coal mining information will increase recuperation planning information. ► The nanominerals showed strong sorption ability to aqueous hazardous elements

  15. Generalization of the Sitnica river drainage system with potential pollution of tributaries

    Directory of Open Access Journals (Sweden)

    Valjarević Aleksandar

    2015-01-01

    Full Text Available Maps are miniature graphic representation of distinct area and as not being completely real require generalization. Cartographic generalization represents a specific investigation method in cartography. Generalization includes the processes of selection, simplification, and symbolization of details according to the purpose and the map scale. The river generalization requires the phase classification, selection, magnification and simplification to being used. Linear symbols are given on the map by their corresponding/characteristic length and remained unchanged even after the generalization. Particular cartographic criterions need to be applied during generalization. In the given case of the Sitnica river drainage system were applied the computer supported generalization based on the software Global Mapper 16.1 and the Open source software QGIS 2.6.1. The Sitnica drainage system is generalized in three levels. The first included digitalization of all linear objects related to the river Sitnica and its tributaries. Second level resulted in vector generalized data that indicate on polluted tributaries, whereas the final, third stage led to construction of multilayered vector map of the Sitnica catchments area with polluted tributaries.

  16. The impact of episodic coal mine drainage pollution on benthic macroinvertebrates in streams in the Anthracite region of Pennsylvania.

    Science.gov (United States)

    Maccausland, A; McTammany, M E

    2007-09-01

    Episodic coal mine drainage, caused by fluctuations in mine discharges relative to stream flow, has devastating effects on aquatic macroinvertebrate communities. Seven stream reaches in the Anthracite region of Pennsylvania were identified as chronically, episodically or not impaired by mine drainage, and sampled seasonally for 1 year to determine the effect of episodic mine drainage on macroinvertebrates. Specific conductance fluctuated seasonally in episodic sites; it was lower in winter when discharge increased and higher in summer when discharges decreased and mine drainage made up a larger proportion of stream flow. Although we hypothesized that episodic streams would have higher macroinvertebrate richness than chronic streams, comparisons showed no differences in richness between treatments. Episodic pollution may result from undersized or poorly maintained passive treatment systems; therefore, intensive macroinvertebrate monitoring may be needed to identify streams being affected by episodic mine drainage because macroinvertebrate richness may be sensitive to water quality fluctuations.

  17. Downeast Drainage - Examining and Communicating the Dynamics of Bacteria Pollution Events in the Gulf of Maine

    Science.gov (United States)

    Smith, S. M.; Brady, D. C.; Cole, K. L.; Jones, S.; McGreavy, B.; Petersen, C.; Rothenheber, D.; Gerard, B.; Roy, S. G.

    2015-12-01

    The New England Sustainability Consortium is an interdisciplinary NSF EPSCoR funded project organized to strengthen the connections between science and decision-making and to advance the practice of sustainability science. The project uses complementary research capacity at several institutions to examine watershed and estuarine processes linked to bacteria pollution affecting shellfish harvesting and beach water quality in the Gulf of Maine. A fundamental research target is the development of a better approach for the prediction of coastal bacteria pollution events that can cause losses in tourism and shellfishery revenue. Enhanced prediction and communication of the events require a simultaneous examination of watershed pollution sources, drainage systems, estuarine residence times and bacterial survival. Our presentation will summarize initial observations from our investigations and stakeholder engagement activities at two project reference sites located in Wells and Bar Harbor, Maine. These will include field measurements, watershed and estuarine modeling outcomes, and stakeholder engagement results that are framed to quantify and explain land-sea interactions linked to bacterial pollution events in locations with varied relief, hydrodynamics, and stakeholder communities.

  18. Progress on Phytoremediation of Drainage Water N and P Pollution in Farmland Drainage Ditches:A Review

    OpenAIRE

    LUO Liang-guo; CHEN Chong-juan; ZHAO Tian-cheng

    2016-01-01

    Water pollution is a main issue that contributes to the water quality-induced shortage of global water resources. After cleaner production technology successfully applied to the industrial pollution control, agricultural non-point source pollution has been the biggest contributor to water pollution, in particular, the leading source of excess nitrogen and phosphorus in surface water and gaining more attention. The phytoremediation technology has been gradually applied to improve surface water...

  19. Air pollution and daily clinic visits for headache in a subtropical city: Taipei, Taiwan.

    Science.gov (United States)

    Chiu, Hui-Fen; Weng, Yi-Hao; Chiu, Ya-Wen; Yang, Chun-Yuh

    2015-02-17

    This study was undertaken to determine whether there was an association between air pollutant levels and daily clinic visits for headache in Taipei, Taiwan. Daily clinic visits for headache and ambient air pollution data for Taipei were obtained for the period from 2006-2011. The odds ratio of clinic visits for headache was estimated using a case-crossover approach, controlling for weather variables, day of the week, seasonality, and long-term time trends. In the single pollutant models, on warm days (≥23 °C) statistically significant positive associations were found for increased rate of headache occurrence and levels of particulate matter (PM10), sulfur dioxide (SO2), nitrogen dioxide (NO2), carbon monoxide (CO), and ozone (O3). On cool days (<23 °C), all pollutants were significantly associated with increased headache visits except SO2. For the two-pollutant models, PM10, O3 and NO2 were significant for higher rate of headache visits in combination with each of the other four pollutants on cool days. On warm days, CO remained statistically significant in all two-pollutant models. This study provides evidence that higher levels of ambient air pollutants increase the risk of clinic visits for headache.

  20. Air pollution and daily clinic visits for migraine in a subtropical city: Taipei, Taiwan.

    Science.gov (United States)

    Chiu, Hui-Fen; Yang, Chun-Yuh

    2015-01-01

    This study was undertaken to determine whether there was an association between air pollutant levels and daily clinic visits for migraine in Taipei, Taiwan. Daily clinic visits for migraine and ambient air pollution data for Taipei were obtained for the period 2006-2011. The relative risk of clinic visits for migraine was estimated using a case-crossover approach, controlling for weather variables, day of the week, seasonality, and long-term time trends. In the single-pollutant models, on warm days (>23°C) statistically significant positive associations were found for increased rate of migraine occurrence and levels of particulate matter (PM10), sulfur dioxide (SO2), nitrogen dioxide (NO2), carbon monoxide (CO), and ozone (O3). On cool days (<23°C), all pollutants were significantly associated with increased migraine visits except CO and SO2. For the two-pollutant models, O3 and NO2 were significant for higher rate of migraine visits in combination with each of the other four pollutants on cool days. On warm days, CO remained statistically significant in all two-pollutant models. This study provides evidence that higher levels of ambient air pollutants enhance the risk of clinic visits for migraine.

  1. Air pollution exposure and daily clinical visits for allergic rhinitis in a subtropical city: Taipei, Taiwan.

    Science.gov (United States)

    Chen, Chih-Cheng; Chiu, Hui-Fen; Yang, Chun-Yuh

    2016-01-01

    This study was undertaken to determine whether there was an association between air pollutant level exposure and daily clinic visits for allergic rhinitis (AR) in Taipei, Taiwan. Daily clinic visits for AR and ambient air pollution data for Taipei were obtained for the period of 2006-2011. The relative risk for clinic visits for AR was estimated using a case-crossover approach, controlling for weather variables, day of the week, seasonality, and long-term time trends. In the single-pollutant models, on warm days (>23ºC) significant positive associations were found for increased rate of AR occurrence and ambient levels of particulate matter (PM10), sulfur dioxide (SO2), nitrogen dioxide (NO2), carbon monoxide (CO), and ozone (O3). On cool days (<23ºC), all air pollutants were significantly associated with elevated number of AR visits except SO2. For the two-pollutant models, PM10, O3, and NO2 were significantly associated with higher rate of AR visits in combination with each of the other four pollutants on cool days. On warm days, CO levels remained significantly related with increased AR visits in all two-pollutant models. This study provides evidence that higher levels of ambient air contaminants enhance the risk of elevated frequency of clinic visits for AR.

  2. From Antarctica to the subtropics: Contrasted geographical concentrations of selenium, mercury, and persistent organic pollutants in skua chicks (Catharacta spp.).

    Science.gov (United States)

    Carravieri, Alice; Cherel, Yves; Brault-Favrou, Maud; Churlaud, Carine; Peluhet, Laurent; Labadie, Pierre; Budzinski, Hélène; Chastel, Olivier; Bustamante, Paco

    2017-09-01

    Seabirds integrate bioaccumulative contaminants via food intake and have revealed geographical trends of contamination in a variety of ecosystems. Pre-fledging seabird chicks are particularly interesting as bioindicators of chemical contamination, because concentrations in their tissues reflect primarily dietary sources from the local environment. Here we measured 14 trace elements and 18 persistent organic pollutants (POPs) in blood of chicks of skuas that breed in four sites encompassing a large latitudinal range within the southern Indian Ocean, from Antarctica (Adélie Land, south polar skua Catharacta maccormicki), through subantarctic areas (Crozet and Kerguelen Islands, brown skua C. lonnbergi), to the subtropics (Amsterdam Island, C. lonnbergi). Stables isotopes of carbon (δ 13 C, feeding habitat) and nitrogen (δ 15 N, trophic position) were also measured to control for the influence of feeding habits on contaminant burdens. Concentrations of mercury (Hg) and selenium (Se) were very high at all the four sites, with Amsterdam birds having the highest concentrations ever reported in chicks worldwide (4.0 ± 0.8 and 646 ± 123 μg g -1 dry weight, respectively). Blood Hg concentrations showed a clear latitudinal pattern, increasing from chicks in Antarctica to chicks in the subantarctic and subtropical islands. Interestingly, blood Se concentrations showed similar between-population differences to Hg, suggesting its involvement in protective mechanisms against Hg toxicity. Chicks' POPs pattern was largely dominated by organochlorine pesticides, in particular DDT metabolites and hexachlorobenzene (HCB). Skua chicks from subantarctic islands presented high concentrations and diversity of POPs. By contrast, chicks from the Antarctic site overall had the lowest concentrations and diversity of both metallic and organic contaminants, with the exception of HCB and arsenic. Skua populations from these sites, being naturally exposed to different quantities of

  3. Fine particulate air pollution and hospital admissions for pneumonia in a subtropical city: Taipei, Taiwan.

    Science.gov (United States)

    Tsai, Shang-Shyue; Yang, Chun-Yuh

    2014-01-01

    This study was undertaken to determine whether there was a correlation between fine particles (PM2.5) levels and hospital admissions for pneumonia in Taipei, Taiwan. Hospital admissions for pneumonia and ambient air pollution data for Taipei were obtained for the period from 2006 to 2010. The relative risk of hospital admissions for pneumonia was estimated using a case-crossover approach, controlling for weather variables, day of the week, seasonality, and long-term time trends. For the single-pollutant model (without adjustment for other pollutants), increased numbers of admissions for pneumonia were significantly associated with higher PM2.5 levels both on warm days (>23°C) and on cool days (<23°C). This was accompanied by an interquartile range elevation correlated with a 12% (95% CI = 16%-13%) and 4% (95% CI = 3%-6%) rise in number of admissions for pneumonia, respectively. In the two-pollutant models, PM2.5 remained significant after inclusion of sulfur dioxide (SO₂) or ozone (O₃) both on warm and on cool days. This study provides evidence that higher levels of PM2.5 increase the risk of hospital admissions for pneumonia.

  4. Transport of desert dust mixed with North African industrial pollutants in the subtropical Saharan Air Layer

    OpenAIRE

    Rodríguez González, Sergio; Alastuey Urós, José Andrés; Alonso Pérez, Silvia; Querol, X.; Cuevas, Emilio; Abreu Afonso, J.; Viana, M.; Pandolfi, M.; Rosa Díaz, Jesús de la

    2011-01-01

    An analysis of chemical composition data of particulate matter samples (TSP, PM10 and PM2.5) collected from 2002 to 2008 in the North Atlantic free troposphere at the Izana Global Atmospheric Watch (GAW) observatory (Tenerife, Canary Islands) shows that desert dust is very frequently mixed with particulate pollutants in the Saharan Air Layer (SAL). The study of this data set with Median Concentrations At Receptor (MCAR) plots allowed the identification of the potential source regions of the d...

  5. Sediment and pollutant load modelling using an integrated urban drainage modelling toolbox: an application of City Drain.

    Science.gov (United States)

    Rodríguez, J P; Achleitner, S; Möderl, M; Rauch, W; Maksimović, C; McIntyre, N; Díaz-Granados, M A; Rodríguez, M S

    2010-01-01

    Numerical and computational modelling of flow and pollutant dynamics in urban drainage systems is becoming more and more integral to planning and design. The main aim of integrated flow and pollutant models is to quantify the efficiency of different measures at reducing the amount of pollutants discharged into receiving water bodies and minimise the consequent negative water quality impact. The open source toolbox CITY DRAIN developed in the Matlab/Simulink environment, which was designed for integrated modelling of urban drainage systems, is used in this work. The goal in this study was to implement and test computational routines for representing sediment and pollutant loads in order to evaluate catchment surface pollution. Tested models estimate the accumulation, erosion and transport of pollutants--aggregately--on urban surfaces and in sewers. The toolbox now includes mathematical formulations for accumulation of pollutants during dry weather period and their wash-off during rainfall events. The experimental data acquired in a previous research project carried out by the Environmental Engineering Research Centre (CIIA) at the Universidad de los Andes in Bogotá (Colombia) was used for the calibration of the models. Different numerical approaches were tested for their ability to calibrate to the sediment transport conditions. Initial results indicate, when there is more than one peak during the rainfall event duration, wash-off processes probably can be better represented using a model based on the flow instead of the rainfall intensity. Additionally, it was observed that using more detailed models (compared with an instantaneous approach) for representing pollutant accumulation do not necessarily lead to better results.

  6. Integrated studies of a regional ozone pollution synthetically affected by subtropical high and typhoon system in the Yangtze River Delta region, China

    Directory of Open Access Journals (Sweden)

    L. Shu

    2016-12-01

    Full Text Available Severe high ozone (O3 episodes usually have close relations to synoptic systems. A regional continuous O3 pollution episode was detected over the Yangtze River Delta (YRD region in China during 7–12 August 2013, in which the O3 concentrations in more than half of the cities exceeded the national air quality standard. The maximum hourly concentration of O3 reached 167.1 ppb. By means of the observational analysis and the numerical simulation, the characteristics and the essential impact factors of the typical regional O3 pollution are comprehensively investigated. The observational analysis shows that the atmospheric subsidence dominated by the western Pacific subtropical high plays a crucial role in the formation of high-level O3. The favorable weather conditions, such as extremely high temperature, low relative humidity and weak wind speed, caused by the abnormally strong subtropical high are responsible for the trapping and the chemical production of O3 in the boundary layer. In addition, when the YRD cities are at the front of Typhoon Utor, the periphery circulation of typhoon system can enhance the downward airflows and cause worse air quality. However, when the typhoon system weakens the subtropical high, the prevailing southeasterly surface wind leads to the mitigation of the O3 pollution. The integrated process rate (IPR analysis incorporated in the Community Multi-scale Air Quality (CMAQ model is applied to further illustrate the combined influence of subtropical high and typhoon system in this O3 episode. The results show that the vertical diffusion (VDIF and the gas-phase chemistry (CHEM are two major contributors to O3 formation. During the episode, the contributions of VDIF and CHEM to O3 maintain the high values over the YRD region. On 10–12 August, the cities close to the sea are apparently affected by the typhoon system, with the contribution of VDIF increasing to 28.45 ppb h−1 in Shanghai and 19.76 ppb h−1 in

  7. Transport of desert dust mixed with North African industrial pollutants in the subtropical Saharan Air Layer

    Science.gov (United States)

    Rodríguez, S.; Alastuey, A.; Alonso-Pérez, S.; Querol, X.; Cuevas, E.; Abreu-Afonso, J.; Viana, M.; Pérez, N.; Pandolfi, M.; de La Rosa, J.

    2011-07-01

    An analysis of chemical composition data of particulate matter samples (TSP, PM10 and PM2.5) collected from 2002 to 2008 in the North Atlantic free troposphere at the Izaña Global Atmospheric Watch (GAW) observatory (Tenerife, Canary Islands) shows that desert dust is very frequently mixed with particulate pollutants in the Saharan Air Layer (SAL). The study of this data set with Median Concentrations At Receptor (MCAR) plots allowed the identification of the potential source regions of the dust and particulate pollutants. Areas located at the south of the southern slope of the Atlas mountains emerge as the most frequent source of the soil desert dust advected to the northern edge of the SAL in summer. Industrial emissions occurring in Northern Algeria, Eastern Algeria, Tunisia and the Atlantic coast of Morocco appear as the most important source of the nitrate, ammonium and a fraction of sulphate (at least 60 % of the sulphate phosphate-based fertilizer industry and power plants. Although desert dust emissions appear as the most frequent source of the phosphorous observed in the SAL, high P concentrations are observed when the SAL is affected by emissions from open mines of phosphate and phosphate based fertilizer industry. The results also show that a significant fraction of the sulphate (up to 90 % of sulphate <10 μm transported from some regions) observed in the SAL may be influenced by soil emissions of evaporite minerals in well defined regions where dry saline lakes (chotts) are present. These interpretations of the MCAR plots are consistent with the results obtained with the Positive Matrix Factorization (PMF2) receptor modelling. The results of this study show that North African industrial pollutants may be mixed with desert dust and exported to the North Atlantic in the Saharan Air Layer.

  8. Transport of desert dust mixed with North African industrial pollutants in the subtropical Saharan Air Layer

    Directory of Open Access Journals (Sweden)

    S. Rodríguez

    2011-07-01

    Full Text Available An analysis of chemical composition data of particulate matter samples (TSP, PM10 and PM2.5 collected from 2002 to 2008 in the North Atlantic free troposphere at the Izaña Global Atmospheric Watch (GAW observatory (Tenerife, Canary Islands shows that desert dust is very frequently mixed with particulate pollutants in the Saharan Air Layer (SAL. The study of this data set with Median Concentrations At Receptor (MCAR plots allowed the identification of the potential source regions of the dust and particulate pollutants. Areas located at the south of the southern slope of the Atlas mountains emerge as the most frequent source of the soil desert dust advected to the northern edge of the SAL in summer. Industrial emissions occurring in Northern Algeria, Eastern Algeria, Tunisia and the Atlantic coast of Morocco appear as the most important source of the nitrate, ammonium and a fraction of sulphate (at least 60 % of the sulphate <10 μm transported from some regions observed in the SAL. These emissions are mostly linked to crude oil refineries, phosphate-based fertilizer industry and power plants. Although desert dust emissions appear as the most frequent source of the phosphorous observed in the SAL, high P concentrations are observed when the SAL is affected by emissions from open mines of phosphate and phosphate based fertilizer industry. The results also show that a significant fraction of the sulphate (up to 90 % of sulphate <10 μm transported from some regions observed in the SAL may be influenced by soil emissions of evaporite minerals in well defined regions where dry saline lakes (chotts are present. These interpretations of the MCAR plots are consistent with the results obtained with the Positive Matrix Factorization (PMF2 receptor modelling. The results of this study show that North African industrial pollutants may be mixed with desert dust and exported to the North Atlantic in the Saharan Air Layer.

  9. Transport of desert dust mixed with North African industrial pollutants in the subtropical Saharan Air Layer

    OpenAIRE

    S. Rodríguez; A. Alastuey; S. Alonso-Pérez; X. Querol; E. Cuevas; J. Abreu-Afonso; M. Viana; N. Pérez; M. Pandolfi; J. de la Rosa

    2011-01-01

    An analysis of chemical composition data of particulate matter samples (TSP, PM10 and PM2.5) collected from 2002 to 2008 in the North Atlantic free troposphere at the Izaña Global Atmospheric Watch (GAW) observatory (Tenerife, Canary Islands) shows that desert dust is very frequently mixed with particulate pollutants in the Saharan Air Layer (SAL). The study of this data set with Median Concentrations At Receptor (MCAR) plots allowed the identification of the potential source regions of the d...

  10. A novel approach for acid mine drainage pollution biomonitoring using rare earth elements bioaccumulated in the freshwater clam Corbicula fluminea.

    Science.gov (United States)

    Bonnail, Estefanía; Pérez-López, Rafael; Sarmiento, Aguasanta M; Nieto, José Miguel; DelValls, T Ángel

    2017-09-15

    Lanthanide series have been used as a record of the water-rock interaction and work as a tool for identifying impacts of acid mine drainage (lixiviate residue derived from sulphide oxidation). The application of North-American Shale Composite-normalized rare earth elements patterns to these minority elements allows determining the origin of the contamination. In the current study, geochemical patterns were applied to rare earth elements bioaccumulated in the soft tissue of the freshwater clam Corbicula fluminea after exposure to different acid mine drainage contaminated environments. Results show significant bioaccumulation of rare earth elements in soft tissue of the clam after 14 days of exposure to acid mine drainage contaminated sediment (ΣREE=1.3-8μg/gdw). Furthermore, it was possible to biomonitor different degrees of contamination based on rare earth elements in tissue. The pattern of this type of contamination describes a particular curve characterized by an enrichment in the middle rare earth elements; a homologous pattern (E MREE =0.90) has also been observed when applied NASC normalization in clam tissues. Results of lanthanides found in clams were contrasted with the paucity of toxicity studies, determining risk caused by light rare earth elements in the Odiel River close to the Estuary. The current study purposes the use of clam as an innovative "bio-tool" for the biogeochemical monitoring of pollution inputs that determines the acid mine drainage networks affection. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. Fate, transport and effects of pollutants originating from acid mine drainage in the Olifants River, South Africa

    CSIR Research Space (South Africa)

    Dabrowski, JM

    2014-08-01

    Full Text Available and Effects of Pollutants Originating from Acid Mine Drainage in the Olifants 1 River, South Africa 2 J.M. Dabrowski1*, J. Dabrowski2,1, L. Hill1, P. McMillan1, Oberholster P.J.3 3 4 1 CSIR, Natural Resources and Environment, PO Box 395, Pretoria, 0001... Gower AM, Myers G, Kent M, Foulkes ME 1994. Relationships between macroinvertebrate 481 communities and environmental variables in metal-contaminated streams in south-west 482 England. Freshwater Biology 32(1): 199-221. 483 Gustafsson JP. 2011. Visual...

  12. Study of Inorganic Pollutants Removal from Acid Mine Drainage by Hemp Hurds

    Science.gov (United States)

    Demcak, Stefan; Balintova, Magdalena

    2016-12-01

    Sulphates in wastewaters have an origin as the by-products of a variety of industrial operations. A specific and major producer of such effluents, which contained sulphates and heavy metals, is the mining industry. These contaminants should be removed from wastewater using an adequate process of treatment. The paper deals with selected heavy metals (iron, cooper, and manganese) and sulphate removal from acid mine drainage outflowing from an abandoned mine in Smolnik (Slovakia) using the modified biosorbent - Holland hemp hurds. Pre-treatment of acid mine drainage was based on oxidation of ferrous cations from acid mine drainage by hydrogen peroxide and subsequent precipitation. The precipitate were analysed by infrared spectrometry which found the precipitate containing hydroxide and sulphate functional groups. During this process the concentration of sulphate decreased by 43.8 %. Hemp hurds modified by NaOH decreased concentration of Cu2+ in solution by about 70 %

  13. Uranium pollution in an estuary affected by pyrite acid mine drainage and releases of naturally occurring radioactive materials

    International Nuclear Information System (INIS)

    Villa, M.; Manjon, G.; Hurtado, S.; Garcia-Tenorio, R.

    2011-01-01

    Highlights: → Huelva estuary is affected by former phosphogypsum releases and pyrite acid mine drainage. → Time evolution of uranium concentration is analyzed after halting of NORM releases. → Two new contamination sources are preventing the complete uranium cleaning: (1) The leaching of phosphogypsum stacks located close to Tinto River. (2) Pyrite acid mine drainage. → High uranium concentrations are dissolved in water and precipitate subsequently. - Abstract: After the termination of phosphogypsum discharges to the Huelva estuary (SW Spain), a unique opportunity was presented to study the response of a contaminated environmental compartment after the cessation of its main source of pollution. The evolution over time of uranium concentrations in the estuary is presented to supply new insights into the decontamination of a scenario affected by Naturally Occurring Radioactive Material (NORM) discharges. The cleaning of uranium isotopes from the area has not taken place as rapidly as expected due to leaching from phosphogypsum stacks. An in-depth study using various techniques of analysis, including 234 U/ 238 U and 230 Th/ 232 Th ratios and the decreasing rates of the uranium concentration, enabled a second source of uranium contamination to be discovered. Increased uranium levels due to acid mine drainage from pyrite mines located in the Iberian Pyrite Belt (SW Spain) prevent complete uranium decontamination and, therefore, result in levels nearly twice those of natural background levels.

  14. Characterization of water pollution in drainage networks using continuous monitoring data in the Citadel area of Hue City, Vietnam.

    Science.gov (United States)

    Nagano, Y; Teraguchi, T; Lieu, P K; Furumai, H

    2014-01-01

    In the Citadel area of Hue City, drainage systems that include canals and ponds are considerable sources of fecal contaminants to inundated water during the rainy season because canals and ponds receive untreated wastewater. It is important to investigate the characteristics of hydraulics and water pollution in canals and ponds. At the canals and ponds, water sampling was conducted during dry and wet weather periods in order to evaluate fecal contamination and to investigate changes in water pollution caused by runoff inflow. Inundated water was also collected from streets during heavy rainfall. At the canals and ponds, concentrations of Escherichia coli and total coliform exceeded the Vietnamese regulation values for surface water in 23 and 24 out of 27 samples (85 and 89%), respectively. The water samples were categorized based on the characteristics of water pollution using cluster analysis. In the rainy season, continuous monitoring was conducted at the canals and ponds using water depth and electrical conductivity (EC) sensors to investigate the dynamic relationship between water level and water pollution. It is suggested that in the canals, high EC meant water stagnation and low EC signified river water inflow. Therefore, EC might be a good indicator of water flow change in canals.

  15. PATTERNS UTILIZED IN THE SIMULATION OF UNDERGROUND WATER FLOW AND THE TRANSPORTATION OF POLLUTANTS IN THE BAHLUI DRAINAGE BASIN

    Directory of Open Access Journals (Sweden)

    Ionut Minea

    2012-03-01

    Full Text Available ABSTRACT. – Patterns utilized in the simulation of underground water flow and the transportation of pollutants in the Bahlui drainage basin. In the actual context of accelerate economic development, the excessive exploatation of water resources from the underground and the contamination of these with different water pollutants has become a major problem which has enetered the attention of many researchers. For the evaluation of an underground water flow and pollutants transport sistem we have chosen the package of programs MODFLOW which includes a whole series of applications,such as MOC3D, MT3D, MT3DMS, PEST, UCODE, PMPATH, which allow simulations and multiple recalibrations of the capacity of recharging of the aquifers, the flowing of the water towards wells and drillings the transport of a pollutant agent in the underground or the evaluation of the exchange of water between the hidrographic network and aquifers. The sistem targets both the evaluation of the modelation of the underground flowing and the simulation of a punctual polluation of the canvas of groundwater scenery, in the meadow of the river Bahlui, west from Letcani village.

  16. Associations between mortality and meteorological and pollutant variables during the cool season in two Asian cities with sub-tropical climates: Hong Kong and Taipei.

    Science.gov (United States)

    Goggins, William B; Chan, Emily Y Y; Yang, Chunyuh; Chong, Marc

    2013-07-19

    Numerous studies have found associations between extreme temperatures and human mortality but relatively few studies have been done in sub-tropical and tropical cities, especially in Asia. In this study we examine the impact of cold temperatures, cold waves and other meteorological and environmental variables on cool season mortality in 2 subtropical Asian cities. Separate analysis of daily mortality time-series from Hong Kong and Taipei using Generalized Additive Models with natural mortality as the outcome daily mean temperature as the main explanatory variable and relative humidity, solar radiation, wind speed, pollutants (nitrogen dioxide (NO(2)), sulfur dioxide (SO(2)), respirable suspended particulates (PM(10)), ozone (O(3)), seasonality and day of the week controlled as potential confounders. Lags up to 35 days were considered for temperature, and distributed lag models were used to determine the number of lags for final models. Subgroup analyses were also done by gender, age group, cause of death and geographical area of residence. Cold temperatures were strongly associated with higher mortality with lagged effects persisting up to 3 weeks in Hong Kong and 2 weeks in Taipei. Cold effects were much stronger for deaths among older people and non-cancer deaths. Prolonged cold spells modestly but significantly raised mortality after accounting for the effects of individual cold days. Higher daily ozone levels were also strongly associated with higher short-term mortality in Taipei and Hong Kong, while relative humidity and solar radiation were weakly and inconsistently associated with mortality. Cold temperatures and cold spells substantially increase short-term mortality in sub-tropical Asian cities particularly among the elderly. Greater attention needs to be paid to the adverse health effects of cold temperatures. Interventions including provisions of shelters, cold weather warnings and education about the possible health effects of cold temperature should

  17. White-faced storm-petrels Pelagodroma marina predated by gulls as biological monitors of plastic pollution in the pelagic subtropical Northeast Atlantic.

    Science.gov (United States)

    Furtado, Ricardo; Menezes, Dilia; Santos, Carolina Jardim; Catry, Paulo

    2016-11-15

    Marine plastic pollution is rapidly growing and is a source of major concern. Seabirds often ingest plastic debris and are increasingly used as biological monitors of plastic pollution. However, virtually no studies have assessed plastics in seabirds in the deep subtropical North Atlantic. We investigated whether remains of white-faced storm-petrels (WFSP) present in gull pellets could be used for biomonitoring. We analysed 263 pellets and 79.0% of these contained plastic debris originating in the digestive tract of WFSP. Pellets with no bird prey did not contain plastics. Most debris were fragments (83.6%) with fewer plastic pellets (8.2%). Light-coloured plastics predominated (71.0%) and the most frequent polymer was HDPE (73.0%). Stable isotopes in toe-nails of WFSP containing many versus no plastics did not differ, indicating no individual specialisation leading to differential plastic ingestion. We suggest WFSP in pellets are highly suitable to monitor the little known pelagic subtropical Northeast Atlantic. Copyright © 2016 Elsevier Ltd. All rights reserved.

  18. Acid mine drainage in the Iberian Pyrite Belt: 1. Hydrochemical characteristics and pollutant load of the Tinto and Odiel rivers.

    Science.gov (United States)

    Nieto, Jose M; Sarmiento, Aguasanta M; Canovas, Carlos R; Olias, Manuel; Ayora, Carlos

    2013-11-01

    Acid mine drainage in the Iberian Pyrite Belt is probably the worst case in the world of surface water pollution associated with mining of sulphide mineral deposits. The Iberian Pyrite Belt is located in SW Iberian Peninsula, and it has been mined during the last 4,500 years. The central and eastern part of the Iberian Pyrite Belt is drained by the Tinto and Odiel rivers, which receive most of the acidic leachates from the mining areas. As a result, the main channels of the Tinto and Odiel rivers are very rich in metals and highly acidic until reaching the Atlantic Ocean. A significant amount of the pollutant load transported by these two rivers is delivered during the rainy season, as is usual in rivers of Mediterranean climate regions. Therefore, in order to have an accurate estimation of the pollutant loads transported by the Tinto and Odiel rivers, a systematic sampling on a weekly basis and a high temporal resolution sampling of floods events were both performed. Results obtained show that metal fluxes are strongly dependent on the study period, highlighting the importance of inter-annual studies involving dry and wet years.

  19. Hydrological modeling of a watershed affected by acid mine drainage (Odiel River, SW Spain). Assessment of the pollutant contributing areas

    Science.gov (United States)

    Galván, L.; Olías, M.; Cánovas, C. R.; Sarmiento, A. M.; Nieto, J. M.

    2016-09-01

    The Odiel watershed drains materials belonging to the Iberian Pyrite Belt, where significant massive sulfide deposits have been mined historically. As a result, a huge amount of sulfide-rich wastes are deposited in the watershed, which suffer from oxidation, releasing acidic lixiviates with high sulfate and metal concentrations. In order to reliably estimate the metal loadings along the watershed a complete series of discharge and hydrochemical data are essential. A hydrological model was performed with SWAT (Soil and Water Assessment Tool) to solve the scarcity of gauge stations along the watershed. The model was calibrated and validated from daily discharge data (from 1980 to 2010) at the outlet of the watershed, river inputs into an existent reservoir, and a flow gauge station close to the northern area of the watershed. Discharge data obtained from the hydrological model, together with analytical data, allowed the estimation of the dissolved pollutant load delivered annually by the Odiel River (e.g. 9140 t of Al, 2760 t of Zn). The pollutant load is influenced strongly by the rainfall regime, and can even double during extremely rainy years. Around 50% of total pollution comes from the Riotinto Mining District, so the treatment of Riotinto lixiviates reaching the Odiel watershed would reduce the AMD (Acid Mine Drainages) in a remarkable way, improving the water quality downstream, especially in the reservoir of Alcolea, currently under construction. The information obtained in this study will allow the optimization of remediation efforts in the watershed, in order to improve its water quality.

  20. Spatial and Seasonal Variations of Heavy Metal Loads in Uyo Urban Drainage Stream under PS and NPS Pollution

    Directory of Open Access Journals (Sweden)

    O. E. Essien

    2012-12-01

    Full Text Available The concentration of heavy metals (HM in the 4km urban drainage stream in Uyo was studied using grab and composite sampling of water from six stations on the stream, and analyzed by a multipurpose atomic absorption spectrophotometer. The data were statistically analyzed using SPSS version 17 software arid correlated between stations and among samples. HM contamination was evaluated with the coefficient and rate of dispersion between stations and the Normalized Scatter Coefficient (NSC. The seasonal distribution of metal pollution varied individually amongst metals at stations. The Fe and Pb concentrations exceeded the safe drinking water standard, rendering the water quality not acceptable for drinking; however, the quality was within the safe limit for crop production along the river bank. The relative.dominance of heavy metals followed a different sequence in upstream leachate effluent from all downstream stations. The NSC in dry-wet season was higher than in wet season, and was in the order: Fe>Cu>Zn>Pb, showing that large but variable concentration of Fe from PS and NPS contaminated the stream at faster rate in the wet season while Pb contaminated at nearly constant rate. However, in the dry season, Fe and Pb depleted at downstream at rates far higher than Zn as Cu was increasing. Fe and Pb could be good pollution monitor for total maximum daily load (TMDL pollution monitoring programme.

  1. Mine drainage treatment

    OpenAIRE

    Golomeova, Mirjana; Zendelska, Afrodita; Krstev, Boris; Golomeov, Blagoj; Krstev, Aleksandar

    2012-01-01

    Water flowing from underground and surface mines and contains high concentrations of dissolved metals is called mine drainage. Mine drainage can be categorized into several basic types by their alkalinity or acidity. Sulfide rich and carbonate poor materials are expected to produce acidic drainage, and alkaline rich materials, even with significant sulfide concentrations, often produce net alkaline water. Mine drainages are dangerous because pollutants may decompose in the environment. In...

  2. The effects of fine particulate air pollution on daily mortality: a case-crossover study in a subtropical city, Taipei, Taiwan.

    Science.gov (United States)

    Tsai, Shang-Shyue; Chang, Chih-Ching; Liou, Saou-Hsing; Yang, Chun-Yuh

    2014-05-12

    This study was undertaken to determine whether there was an association between PM2.5 levels and daily mortality in Taipei, Taiwan, the largest metropolitan city with a subtropical climate. Daily mortality, air pollution, and weather data for Taipei were obtained for the period from 2006-2008. The relative risk of daily mortality was estimated using a time-stratified case-crossover approach, controlling for weather variables, day of the week, seasonality, and long-term time trends. For the single pollutant model, PM2.5 showed association with total mortality both on warm (>23 °C) and cool days (<23 °C). There is no indication of an association between PM2.5 and risk of death due to respiratory diseases both on warm and cool days. PM2.5 had effects on the risk of death from cardiovascular diseases only on cool days. In the two-pollutant models, PM2.5 remained effects on the risk of mortality for all cause and cardiovascular disease after the inclusion of SO2 and O3 both on warm and cool days. This study provides evidence that short-term exposure to PM2.5 increased the risk of death for all cause and cardiovascular disease.

  3. Pilot test of pollution control and metal resource recovery for acid mine drainage.

    Science.gov (United States)

    Yan, Bo; Mai, Ge; Chen, Tao; Lei, Chang; Xiao, Xianming

    2015-01-01

    The study was undertaken in order to recover the metal resources from acid mine drainage (AMD). A 300 m(3)/d continuous system was designed and fractional precipitation technology employed for the main metals Fe, Cu, Zn, and Mn recovery. The system was operated for six months using actual AMD in situ. The chemicals' input and also the retention time was optimized. Furthermore, the material balance was investigated. With the system, the heavy metals of the effluent after the Mn neutralization precipitation were below the threshold value of the Chinese integrated wastewater discharge limit. The precipitates generated contained 42%, 12%, 31%, and 18% for Fe, Cu, Zn, and Mn, respectively, and the recovery rates of Fe, Cu, Zn, and Mn were 82%, 79%, 83%, and 83%, respectively. The yield range of the precipitate had significant correlation with the influent metal content. Using the X-ray diffraction analysis, the refinement for Fe, Cu, and Zn could be achieved through the processes of roasting and floatation. Cost-benefit was also discussed; the benefit from the recycled metal was able to pay for the cost of chemical reagents used. Most important of all, through the use of this technology, the frustrating sludge problems were solved.

  4. Effect of drainage on CO2, CH4, and N2O fluxes from aquaculture ponds during winter in a subtropical estuary of China.

    Science.gov (United States)

    Yang, Ping; Lai, Derrick Y F; Huang, Jia F; Tong, Chuan

    2018-03-01

    Aquaculture ponds are dominant features of the landscape in the coastal zone of China. Generally, aquaculture ponds are drained during the non-culture period in winter. However, the effects of such drainage on the production and flux of greenhouse gases (GHGs) from aquaculture ponds are largely unknown. In the present study, field-based research was performed to compare the GHG fluxes between one drained pond (DP, with a water depth of 0.05m) and one undrained pond (UDP, with a water depth of 1.16m) during one winter in the Min River estuary of southeast China. Over the entire study period, the mean CO 2 flux in the DP was (0.75±0.12) mmol/(m 2 ·hr), which was significantly higher than that in the UDP of (-0.49±0.09) mmol/(m 2 ·hr) (paquaculture ponds from a net sink to a net source of CO 2 in winter. Mean CH 4 and N 2 O emissions were significantly higher in the DP compared to those in the UDP (CH 4 =(0.66±0.31) vs. (0.07±0.06) mmol/(m 2 ·hr) and N 2 O=(19.54±2.08) vs. (0.01±0.04) µmol/(m 2 ·hr)) (paquaculture ponds can increase the emissions of potent GHGs from the coastal zone of China to the atmosphere during winter, further aggravating the problem of global warming. Copyright © 2017. Published by Elsevier B.V.

  5. Association between fine particulate air pollution and hospital admissions for chest pain in a subtropical city: Taipei, Taiwan.

    Science.gov (United States)

    Chen, Chih-Cheng; Yang, Chun-Yuh

    2017-01-01

    This study determined the association between fine particles (PM 2.5 ) levels and hospital admissions for chest pain (CP) in Taipei, Taiwan. Hospital admissions for CP and ambient air pollution data for Taipei were obtained for the period 2009-2013. The relative risk of hospital admissions was estimated using a case-crossover approach, after controlling for weather variables, day of the week, seasonality, and long-term time trends. For single-pollutant models (without adjustment for other pollutants), increased frequency of CP admissions was significantly associated with PM 2.5 levels on warm days (>23°C), with an interquartile range rise correlated with a 15% (95% confidence interval = 11-31%) elevation in number of CP admissions. In two-pollutant models, PM 2.5 remained significant after inclusion of each of the other four pollutants: sulfur dioxide (SO 2 ), nitrogen dioxide (NO 2 ), carbon monoxide (CO), and ozone (O 3 ) on warm days. Generally, no marked associations were observed between PM 2.5 levels and risk of CP admissions on cool days in both single- and two-pollutant models. This study provides evidence that higher PM 2.5 concentrations enhance the risk of hospital admissions for CP on warm days.

  6. Subtropical forest catchments in South China provide an efficient biological N sink alleviating regional N pollution: evidence from dual nitrate isotopes

    Science.gov (United States)

    Yu, L.; Mulder, J.; Zhu, J.; Zhang, X. S.; Dörsch, P.

    2016-12-01

    In warm-humid subtropics of South China, enhanced N deposition has led to extreme N saturation in a wide range of forests, with significant nitrate (NO3-) leaching from well-drained soils. Yet, the imbalanced N budget, with limited N export by stream runoff, reveals strong N retention in these forest catchments. Here, to strengthen our understanding of catchment-scale N turnover, we combine a dual NO3- isotope study with weekly inorganic N flux monitoring for two years, across five southern forest catchments in China. In each catchment, data were collected along a hydrological continuum consisting of a hill slope (HS), a groundwater discharge zone (GDZ) and a stream outlet. Combined for all catchments, the data show that the atmogenic ammonium (NH4+) is efficiently removed in the soil pore water of HS, while NO3- is produced. Depleted δ15N and δ18O signals in NO3- on the HS suggested the occurrence of efficient nitrification. In the GDZ, the strong decline in NO3- concentration associated with significant increase in δ15N and δ18O of NO3- indicated denitrification as the dominant N sink. Such uniform N turnover pattern may be attributed to similar climatic and topographic conditions, which facilitate efficient N transformation and transport along the hydrological continuum. In-out N budgets across these sites revealed that elevated N deposition stimulated catchment N retention, which was matched by increasing difference in 15N enrichment of NO3- between HS and GDZ. Thus, N attenuation by denitrification in South Chinese forest catchments appears to be driven by N deposition load in a range of 10 to 50 kg ha-1 yr-1. Our study demonstrates widely overlooked N sink function of subtropical forest catchments, which may be of great importance for alleviating regional N pollution.

  7. Epilithic and endolithic microorganisms and deterioration on stone church facades subject to urban pollution in a sub-tropical climate.

    Science.gov (United States)

    Gaylarde, Christine; Baptista-Neto, Jose Antônio; Ogawa, Akiko; Kowalski, Matthew; Celikkol-Aydin, Sukriye; Beech, Iwona

    2017-02-01

    Weathering of two church facades in Rio de Janeiro was caused substantially by salts, mainly halite and gypsum, detected by SEM and chemical analyses, which cause physical stresses by deposition within the rock. Biofilm populations, determined by SEM and as operational taxonomic units (OTUs), degraded stone by penetration, solubilization and redeposition of minerals on their surfaces. Endolithic cyanobacteria were associated with gypsum deposits. Microbiomes were typical for high-stress environments, high salt, intense insolation, low water and low nutrients (eg halophilic Rubrobacter, Salinicola, Sterigmatomyces). The main colonizers on the church most affected by traffic (Nossa Senhora da Candelária - CA) were Actinobacteria; Gammaproteobacteria (chiefly Pseudomonas) were predominant on the site situated in a leafy square (São Francisco de Paula - SF). Major Gammaproteobacteria on CA were halophilic Halomonas and Rhodobacteriaceae. Fungal OTUs on both churches were principally dimorphic, yeast-like basidiomycetes. Many OTUs of thermophilic microorganisms (eg the Thermomicrobia class, Chloroflexi) were present. This is the first use of next generation sequencing (NGS) to study microbial biofilm interactions with metamorphic and granite buildings in an intensely urban, sub-tropical climate.

  8. Association between Fine Particulate Air Pollution and Daily Clinic Visits for Migraine in a Subtropical City: Taipei, Taiwan.

    Science.gov (United States)

    Chen, Chih-Cheng; Tsai, Shang-Shyue; Yang, Chun-Yuh

    2015-04-29

    This study was undertaken to determine whether there was an association between fine particle (PM₂.₅) levels and daily clinic visits for migraine in Taipei, Taiwan. Daily clinic visits for migraine and ambient air pollution data for Taipei were obtained for the period from 2006-2011. The odds ratio of clinic visits was estimated using a case-crossover approach, controlling for weather variables, day of the week, seasonality, and long-term time trends. Generally, no significant associations between PM₂.₅ levels and migraine visits were observed on cool days. On warm days, however, for the single pollutant model (without adjustment for other pollutants), increased clinic visits for migraine were significantly associated with PM₂.₅ levels, with an interquartile range (IQR) rise associated with a 13% (95% CI = 8%-19%) elevation in number of migraine visits. In bi-pollutant model, PM₂.₅ remained significant after the inclusion of sulfur dioxide (SO₂) or ozone (O₃) on warm days. This study provides evidence that higher levels of PM₂.₅ increase the risk of clinic visits for migraine in Taipei, Taiwan.

  9. Long term remediation of highly polluted acid mine drainage: A sustainable approach to restore the environmental quality of the Odiel river basin

    International Nuclear Information System (INIS)

    Caraballo, Manuel A.; Macias, Francisco; Roetting, Tobias S.; Nieto, Jose Miguel; Ayora, Carlos

    2011-01-01

    During 20 months of proper operation the full scale passive treatment in Mina Esperanza (SW Spain) produced around 100 mg/L of ferric iron in the aeration cascades, removing an average net acidity up to 1500 mg/L as CaCO 3 and not having any significant clogging problem. Complete Al, As, Cd, Cr, Cu, Ti and V removal from the water was accomplished through almost the entire operation time while Fe removal ranged between 170 and 620 mg/L. The system operated at a mean inflow rate of 43 m 3 /day achieving an acid load reduction of 597 g.(m 2 day) -1 , more than 10 times higher than the generally accepted 40 g.(m 2 day) -1 value commonly used as a passive treatment system designing criteria. The high performance achieved by the passive treatment system at Mina Esperanza demonstrates that this innovative treatment design is a simple, efficient and long lasting remediation option to treat highly polluted acid mine drainage. - Highlights: → Novel reactive mixture enable 20 month of high hydraulic conductivity. → Acid load reduction improved 10 times comparing to vertical flow wetland. → High biotic and abiotic iron oxidation and removal. → Complete Al, As, Cd, Cr, Cu, Ti and V water removal. - A high permeable alkaline reactive substrate offers a sustainable option to remediate severely polluted acid mine drainage in the Odiel basin

  10. A geochemical approach to the restoration plans for the Odiel River basin (SW Spain), a watershed deeply polluted by acid mine drainage.

    Science.gov (United States)

    Macías, Francisco; Pérez-López, Rafael; Caraballo, Manuel A; Sarmiento, Aguasanta M; Cánovas, Carlos R; Nieto, Jose M; Olías, Manuel; Ayora, Carlos

    2017-02-01

    The Odiel River Basin (SW Spain) drains the central part of the Iberian Pyrite Belt (IPB), a world-class example of sulfide mining district and concomitantly of acid mine drainage (AMD) pollution. The severe AMD pollution and the incipient state of remediation strategies implemented in this region, coupled with the proximity of the deadline for compliance with the European Water Framework Directive (WFD), urge to develop a restoration and water resources management strategy. Furthermore, despite the presence of some reservoirs with acid waters in the Odiel basin, the construction of the Alcolea water reservoir has already started. On the basis of the positive results obtained after more than 10 years of developing a specific passive remediation technology (dispersed alkaline substrate (DAS)) for the highly polluted AMD of this region, a restoration strategy is proposed. The implementation of 13 DAS treatment plants in selected acid discharges along the Odiel and Oraque sub-basins and other restoration measurements of two acidic creeks is proposed as essential to obtain a good water quality in the future Alcolea reservoir. This restoration strategy is also suggested as an economically and environmentally sustainable approach to the extreme metal pollution affecting the waters of the region and could be considered the starting point for the future compliance with the WFD in the Odiel River Basin.

  11. Copper removal from acid mine drainage-polluted water using glutaraldehyde-polyethyleneimine modified diatomaceous earth particles

    Directory of Open Access Journals (Sweden)

    Mikael Larsson

    2018-02-01

    Full Text Available Mine waters and tailings generated from mining and mineral processing activities often have detrimental impact on the local environment. One example is acid mine drainage, in which sulphides in the mining waste react with water and oxygen to produce an acidic environment that subsequently dissolves host rock minerals from the waste containing toxic metals and trace elements. Copper is one such metal of significance, as it is mined at large volumes in sulphide containing ores. It has strong biocidal activity that greatly affects ecosystems. We have previously reported that glutaraldehyde (GA-crosslinked polyethyleneimine (PEI has strong affinity and selectivity for copper and that diatomaceous earth (DE particles can be modified with the material to form a copper-extraction resin. In this study, the copper uptake of GA-PEI-DE particles was investigated from synthetic and real acid mine drainage samples under different pHs and their copper removal performance was compared with that of selected commercial resins. The results revealed that copper could effectively and preferentially bind to the material at pH 4, and that the copper could be completely eluted by lowering of the pH. In addition, effective copper uptake and elution was demonstrated using real legacy acid mine drainage water from Mount Lyell in Tasmania.

  12. Copper removal from acid mine drainage-polluted water using glutaraldehyde-polyethyleneimine modified diatomaceous earth particles.

    Science.gov (United States)

    Larsson, Mikael; Nosrati, Ataollah; Kaur, Simarpreet; Wagner, Jochen; Baus, Ulf; Nydén, Magnus

    2018-02-01

    Mine waters and tailings generated from mining and mineral processing activities often have detrimental impact on the local environment. One example is acid mine drainage, in which sulphides in the mining waste react with water and oxygen to produce an acidic environment that subsequently dissolves host rock minerals from the waste containing toxic metals and trace elements. Copper is one such metal of significance, as it is mined at large volumes in sulphide containing ores. It has strong biocidal activity that greatly affects ecosystems. We have previously reported that glutaraldehyde (GA)-crosslinked polyethyleneimine (PEI) has strong affinity and selectivity for copper and that diatomaceous earth (DE) particles can be modified with the material to form a copper-extraction resin. In this study, the copper uptake of GA-PEI-DE particles was investigated from synthetic and real acid mine drainage samples under different pHs and their copper removal performance was compared with that of selected commercial resins. The results revealed that copper could effectively and preferentially bind to the material at pH 4, and that the copper could be completely eluted by lowering of the pH. In addition, effective copper uptake and elution was demonstrated using real legacy acid mine drainage water from Mount Lyell in Tasmania.

  13. Acid rock drainage in the uranium mining and milling site of Pocos de Caldas, Brazil -- duration assessment, pollutant generation modelling and remediation strategies

    International Nuclear Information System (INIS)

    Fernandes, H.M.; Franklin, M.R.

    2002-01-01

    This geochemical modeling work was carried out to simulate the acid drainage generation from one of the waste-rock piles at the Pocos de Caldas uranium mining site. The mathematical code STEADQYL was used. The estimated results were in good agreement for sulphate and uranium concentrations and the duration of the acid water generation was estimated to be about 500 years. The effect of covering the dump with a material that minimized oxygen diffusion was assessed. Projections indicated that covering the dump with a 1.0 m thickness of a material (like clay), which had an oxygen diffusion coefficient of 10 9 m 2 ·s 1 , would reduce the pollutant concentrations to acceptable values. The estimated cost, when using this strategy, would be about US $10 million. (author)

  14. Subsurface drainage

    CSIR Research Space (South Africa)

    Van Der Merwe, CJ

    1993-09-01

    Full Text Available The report describes the findings of the research project on subsurface drainage. The need for drainage was quantified by evaluating HVS tests on wet pavements. Geotextiles were investigated and various tests performed. Soil/geotextile compatibility...

  15. Microbial reduction of ferric iron oxyhydroxides as a way for remediation of grey forest soils heavily polluted with toxic metals by infiltration of acid mine drainage

    Science.gov (United States)

    Georgiev, Plamen; Groudev, Stoyan; Spasova, Irena; Nicolova, Marina

    2015-04-01

    The abandoned uranium mine Curilo is a permanent source of acid mine drainage (AMD) which steadily contaminated grey forest soils in the area. As a result, the soil pH was highly acidic and the concentration of copper, lead, arsenic, and uranium in the topsoil was higher than the relevant Maximum Admissible Concentration (MAC) for soils. The leaching test revealed that approximately half of each pollutant was presented as a reducible fraction as well as the ferric iron in horizon A was presented mainly as minerals with amorphous structure. So, the approach for remediation of the AMD-affected soils was based on the process of redoxolysis carried out by iron-reducing bacteria. Ferric iron hydroxides reduction and the heavy metals released into soil solutions was studied in the dependence on the source of organic (fresh or silage hay) which was used for growth and activity of soil microflora, initial soil pH (3.65; 4.2; and 5.1), and the ion content of irrigation solutions. The combination of limestone (2.0 g/ kg soil), silage addition (at rate of 45 g dry weight/ kg soil) in the beginning and reiterated at 6 month since the start of soil remediation, and periodical soil irrigation with slightly acidic solutions containing CaCl2 was sufficient the content of lead and arsenic in horizon A to be decreased to concentrations similar to the relevant MAC. The reducible, exchangeable, and carbonate mobile fractions were phases from which the pollutants was leached during the applied soil remediation. It determined the higher reduction of the pollutants bioavailability also as well as the process of ferric iron reduction was combined with neutralization of the soil acidity to pH (H2O) 6.2.

  16. Diversity of metazoan parasites of the African catfish Clarias gariepinus (Burchell, 1822) as indicators of pollution in a subtropical African river system.

    Science.gov (United States)

    Madanire-Moyo, G; Barson, M

    2010-06-01

    The relationship between parasite species diversity and organic pollution in the upper Manyame catchment, Zimbabwe, was investigated between October 2006 and January 2007. The parasite assemblage comprised 13 species in total. Species richness in the unpolluted sites was high; in the moderately polluted sites, it was low, while in the polluted sites, only one parasite species was encountered. Component community diversity, as measured by the Shannon index (H'), decreased with increase in organic pollution. The distribution and occurrence of ectoparasites (Dolops ranarum, Lamproglena clariae, Chonopeltis sp. and Macrogyrodactylus sp.) and one endoparasite (Lytocestus sp.) were limited to the unpolluted sites, demonstrating their sensitivity to organic pollution. The prevalence of the nematodes Paracamallanus cyathopharynx, Procamallanus laevionchus and Contracaecum spp. larvae decreased along the pollution gradient, showing their high sensitivity to organic pollution. The platyhelminths Diplostomum sp. and Polyonchobothrium clarias were the most tolerant and occurred at both polluted and unpolluted sites. Proteocephalus sp. and Caryophyllaeus sp. were limited to the polluted sites, probably as a result of high abundance of oligochaetes and copepods, their intermediate hosts that thrive in sewage-enriched sediments, at the downstream sites. The observed results assume that the decrease in parasite diversity can be related to increased organic pollution. Some parasites requiring complex life histories were absent along with pollution-related disappearance of their vector hosts. Further studies should address the identification of parasite life stages that are more sensitive to pollutants.

  17. Hydrogeochemical and mineralogical characteristics related to heavy metal attenuation in a stream polluted by acid mine drainage: a case study in Dabaoshan Mine, China.

    Science.gov (United States)

    Zhao, Huarong; Xia, Beicheng; Qin, Jianqiao; Zhang, Jiaying

    2012-01-01

    Dabaoshan Mine, the largest mine in south China, has been developed since the 1970s. Acid mine drainage (AMD) discharged from the mine has caused severe environmental pollution and human health problems. In this article, chemical characteristics, mineralogy of ocher precipitations and heavy metal attenuation in the AMD are discussed based on physicochemical analysis, mineral analysis, sequential extraction experiments and hydrogeochemistry. The AMD chemical characteristics were determined from the initialwater composition, water-rock interactions and dissolved sulfide minerals in the mine tailings. The waters, affected and unaffected by AMD, were Ca-SO4 and Ca-HCO3 types, respectively. The affected water had a low pH, high SO4(2-) and high heavy metal content and oxidation as determined by the Fe2+/Fe3+ couple. Heavy metal and SO4(2-) contents of Hengshi River water decreased, while pH increased, downstream. Schwertmannite was the major mineral at the waste dump, while goethite and quartz were dominant at the tailings dam and streambed. Schwertmannite was transformed into goethite at the tailings dam and streambed. The sulfate ions of the secondary minerals changed from bidentate- to monodentate-complexes downstream. Fe-Mn oxide phases of Zn, Cd and Pb in sediments increased downstream. However, organic matter complexes of Cu in sediments increased further away from the tailings. Fe3+ mineral precipitates and transformations controlled the AMD water chemistry.

  18. Long term remediation of highly polluted acid mine drainage: a sustainable approach to restore the environmental quality of the Odiel river basin.

    Science.gov (United States)

    Caraballo, Manuel A; Macías, Francisco; Rötting, Tobias S; Nieto, José Miguel; Ayora, Carlos

    2011-12-01

    During 20 months of proper operation the full scale passive treatment in Mina Esperanza (SW Spain) produced around 100 mg/L of ferric iron in the aeration cascades, removing an average net acidity up to 1500 mg/L as CaCO(3) and not having any significant clogging problem. Complete Al, As, Cd, Cr, Cu, Ti and V removal from the water was accomplished through almost the entire operation time while Fe removal ranged between 170 and 620 mg/L. The system operated at a mean inflow rate of 43 m(3)/day achieving an acid load reduction of 597 g·(m(2) day)(-1), more than 10 times higher than the generally accepted 40 g·(m(2) day)(-1) value commonly used as a passive treatment system designing criteria. The high performance achieved by the passive treatment system at Mina Esperanza demonstrates that this innovative treatment design is a simple, efficient and long lasting remediation option to treat highly polluted acid mine drainage. Copyright © 2011 Elsevier Ltd. All rights reserved.

  19. Performance of Denitrifying Bioreactors at Reducing  Agricultural Nitrogen Pollution in a Humid  Subtropical Coastal Plain Climate

    Directory of Open Access Journals (Sweden)

    Timothy Rosen

    2017-02-01

    Full Text Available Denitrifying bioreactors are an agricultural best management practice developed in the  midwestern United States to treat agricultural drainage water enriched with nitrate‐nitrogen (NO3N. The practice is spreading rapidly to agricultural regions with poor water quality due to nutrient  enrichment. This makes it imperative to track bioreactor NO3‐N reduction efficiency as this practice  gets deployed to new regions. This study evaluated the application and performance of denitrifying  bioreactors in the humid subtropical coastal plain environment of the Chesapeake Bay catchment to  provide data about regionally specific NO3‐N reduction efficiencies. NO3‐N samples were taken  before  and  after  treatment  at  three  denitrifying  bioreactors,  in  addition  to  other  nutrients  (orthophosphate‐phosphorus,  PO4‐P;  ammonium‐nitrogen,  NH4‐N;  total  nitrogen,  TN;  total  phosphorus,  TP  and  water  quality  parameters  (dissolved  oxygen,  DO;  oxidation  reduction  potential,  ORP;  pH;  specific  conductance,  SPC.  Total  removal  ranged  drastically  between  bioreactors from 10 to 133 kg N, with removal efficiencies of 9.0% to 62% and N removal rates of  0.21 to 5.36 g N removed per m3 of bioreactor per day. As the first bioreactor study in the humid  subtropical coastal plain, this data provides positive proof of concept that denitrifying bioreactor is  another tool for reducing N loads in agricultural tile drainage in this region.

  20. Pollution

    NARCIS (Netherlands)

    Dürr, E.; Jaffe, R.; Nonini, D.M.

    2014-01-01

    This essay points to the role of pollution in understanding the social construction of hierarchies and urban space. Conceptualizations of pollution and approaches to waste management always reflect the Zeitgeist and tend to be politically charged. We argue that an ethnographic approach to pollution

  1. Forest drainage

    Science.gov (United States)

    R.W. Skaggs; S. Tian; G.M. Chescheir; Devendra Amatya; M.A. Youssef

    2016-01-01

    Most of the world's 4030 million ha of forested lands are situated on hilly, mountainous or well-drained upland landscapes where improved drainage is not needed. However, there are millions of hectares of poorly drained forested lands where excessively wet soil conditions limit tree growth and access for harvesting and other management activities. Improved or...

  2. Acid mine drainage

    Science.gov (United States)

    Bigham, Jerry M.; Cravotta, Charles A.

    2016-01-01

    Acid mine drainage (AMD) consists of metal-laden solutions produced by the oxidative dissolution of iron sulfide minerals exposed to air, moisture, and acidophilic microbes during the mining of coal and metal deposits. The pH of AMD is usually in the range of 2–6, but mine-impacted waters at circumneutral pH (5–8) are also common. Mine drainage usually contains elevated concentrations of sulfate, iron, aluminum, and other potentially toxic metals leached from rock that hydrolyze and coprecipitate to form rust-colored encrustations or sediments. When AMD is discharged into surface waters or groundwaters, degradation of water quality, injury to aquatic life, and corrosion or encrustation of engineered structures can occur for substantial distances. Prevention and remediation strategies should consider the biogeochemical complexity of the system, the longevity of AMD pollution, the predictive power of geochemical modeling, and the full range of available field technologies for problem mitigation.

  3. Exploring Agricultural Drainage's Influence on Wetland and ...

    Science.gov (United States)

    Artificial agricultural drainage (i.e. surface ditches or subsurface tile) is an important agricultural management tool. Artificial drainage allows for timely fieldwork and adequate root aeration, resulting in greater crop yields for farmers. This practice is widespread throughout many regions of the United States and the network of artificial drainage is especially extensive in flat, poorly-drained regions like the glaciated Midwest. While beneficial for crop yields, agricultural drains often empty into streams within the natural drainage system. The increased network connectivity may lead to greater contributing area for watersheds, altered hydrology and increased conveyance of pollutants into natural water bodies. While studies and models at broader scales have implicated artificial drainage as an important driver of hydrological shifts and eutrophication, the actual spatial extent of artificial drainage is poorly known. Consequently, metrics of wetland and watershed connectivity within agricultural regions often fail to explicitly include artificial drainage. We use recent agricultural census data, soil drainage data, and land cover data to create estimates of potential agricultural drainage across the United States. We estimate that agricultural drainage in the US is greater than 31 million hectares and is concentrated in the upper Midwest Corn Belt, covering greater than 50% of available land for 114 counties. Estimated drainage values for numerous countie

  4. Analysis on Heavy Metal Distribution in Overlying Deposit and Pollution Characteristics in Drainage Basin of Xiaojiang River in Dongchuan District, China

    Science.gov (United States)

    Huang, Qianrui; Cheng, Xianfeng; Xu, Jun; Qi, Wufu; Yang, Shuran; Dong, Tao; Zhang, Xiangqun

    2017-12-01

    The distribution characteristics of heavy metal (Cu, Zn, As, Pb and Cd) content in overlying deposit in Xiaojiang River is analyzed in this thesis, and potential ecological risk index is adopted to evaluate the potential ecological risk of heavy metal pollution in the overlying deposit. Results indicate that the heavy metal (Cu, Zn, As, Pb and Cd) content in overlying deposit in Xiaojiang River all has exceeded standard, especially the content near diggings which is much higher than the national first standard value. And this will affect the bottom mud and river system of Jinsha River to some extent. Cu and Cd are the key pollutants and should be taken as the key object of study. It can be seen from comparison between samples in wet season and that in dry season that pollutants in bottom mud will be released due to the effect of pH value, and secondary pollution of the river will be caused.

  5. Sustainable Drainage Systems

    Directory of Open Access Journals (Sweden)

    Miklas Scholz

    2015-05-01

    Full Text Available Urban water management has somewhat changed since the publication of The Sustainable Drainage System (SuDS Manual in 2007 [1], transforming from building traditional sewers to implementing SuDS, which are part of the best management practice techniques used in the USA and seen as contributing to water-sensitive urban design in Australia. Most SuDS, such as infiltration trenches, swales, green roofs, ponds, and wetlands, address water quality and quantity challenges, and enhance the local biodiversity while also being acceptable aesthetically to the public. Barriers to the implementation of SuDS include adoption problems, flood and diffuse pollution control challenges, negative public perception, and a lack of decision support tools addressing, particularly, the retrofitting of these systems while enhancing ecosystem services. [...

  6. The subtropical nutrient spiral

    Science.gov (United States)

    Jenkins, William J.; Doney, Scott C.

    2003-12-01

    We present an extended series of observations and more comprehensive analysis of a tracer-based measure of new production in the Sargasso Sea near Bermuda using the 3He flux gauge technique. The estimated annually averaged nitrate flux of 0.84 ± 0.26 mol m-2 yr-1 constitutes only that nitrate physically transported to the euphotic zone, not nitrogen from biological sources (e.g., nitrogen fixation or zooplankton migration). We show that the flux estimate is quantitatively consistent with other observations, including decade timescale evolution of the 3H + 3He inventory in the main thermocline and export production estimates. However, we argue that the flux cannot be supplied in the long term by local diapycnal or isopycnal processes. These considerations lead us to propose a three-dimensional pathway whereby nutrients remineralized within the main thermocline are returned to the seasonally accessible layers within the subtropical gyre. We describe this mechanism, which we call "the nutrient spiral," as a sequence of steps where (1) nutrient-rich thermocline waters are entrained into the Gulf Stream, (2) enhanced diapycnal mixing moves nutrients upward onto lighter densities, (3) detrainment and enhanced isopycnal mixing injects these waters into the seasonally accessible layer of the gyre recirculation region, and (4) the nutrients become available to biota via eddy heaving and wintertime convection. The spiral is closed when nutrients are utilized, exported, and then remineralized within the thermocline. We present evidence regarding the characteristics of the spiral and discuss some implications of its operation within the biogeochemical cycle of the subtropical ocean.

  7. Stormwater Drainage Wells

    Science.gov (United States)

    Provides information for identifying stormwater drainage wells, learn how to comply with regulations for storm water drainage wells, and how to reduce the threat to ground water from stormwater injection wells.

  8. Drainage of radioactive areas

    International Nuclear Information System (INIS)

    1981-04-01

    This Code of Practice covers all the drainage systems which may occur in the radioactive classified area of an establishment, namely surface water, foul, process and radioactive drainage. It also deals with final discharge lines. The Code of Practice concentrates on those aspects of drainage which require particular attention because the systems are in or from radioactive areas and typical illustrations are given in appendices. The Code makes references to sources of information on conventional aspects of drainage design. (author)

  9. Radiation mutagenesis of subtropic plants

    International Nuclear Information System (INIS)

    Kerkadze, I.G.

    1987-01-01

    Possibilities of expansion of subtropic plant changeability and development of new gene bank for future selection-genetic studies are detected. New trends of radiation mutagenesis of subtropic plants are formulated as results of studies during many years. A lot of mutants is subjected to sufficient tests, and concrete results are obtained with the help of these tests for definite species. Summing genetic and selection estimations of the results, it is possible to make the conclusion that mutant selection represents one of the powerful methods of preparation of productive and qualitative species of subtropic plants, which are successfully introduced into practice

  10. 33 CFR 157.134 - Cargo tank drainage.

    Science.gov (United States)

    2010-07-01

    ...) POLLUTION RULES FOR THE PROTECTION OF THE MARINE ENVIRONMENT RELATING TO TANK VESSELS CARRYING OIL IN BULK Crude Oil Washing (COW) System on Tank Vessels Design, Equipment, and Installation § 157.134 Cargo tank drainage. Each cargo tank must be designed for longitudinal and transverse drainage of crude oil to allow...

  11. Percutaneous transhepatic biliary drainage

    International Nuclear Information System (INIS)

    Park, Jae Hyung; Hong, Seong Mo; Han, Man Chung

    1982-01-01

    Percutaneous transhepatic biliary drainage was successfully made 20 times on 17 patients of obstructive jaundice for recent 1 year since June 1981 at Department of Radiology in Seoul National University Hospital. The causes of obstructive jaundice was CBD Ca in 13 cases, metastasis in 2 cases, pancreatic cancer in 1 case and CBD stone in 1 case. Percutaneous transhepatic biliary drainage is a relatively ease, safe and effective method which can be done after PTC by radiologist. It is expected that percutaneous transhepatic biliary drainage should be done as an essential procedure for transient permanent palliation of obstructive jaundice

  12. adequacy of drainage channels f drainage channels in a small

    African Journals Online (AJOL)

    eobe

    carried out and data obtain from drainage channels. The time of concentratio version of version of Kirpich equation (new equation of time new equation of time from the drainage channels were determined using results showed that most of the drainage channels h. All the drainage channels of basin A had velocities ra.

  13. Acid Mine Drainage Treatment

    National Research Council Canada - National Science Library

    Fripp, Jon

    2000-01-01

    .... Acid mine drainage (AMD) can have severe impacts to aquatic resources, can stunt terrestrial plant growth and harm wetlands, contaminate groundwater, raise water treatment costs, and damage concrete and metal structures...

  14. Thematic survey of subsurface drainage systems in the Czech Republic

    Czech Academy of Sciences Publication Activity Database

    Tlapáková, L.; Žaloudík, Jiří; Kolejka, Jaromír

    2017-01-01

    Roč. 13, č. 2 (2017), s. 55-65 ISSN 1744-5647 Institutional support: RVO:60077344 ; RVO:68145535 Keywords : subsurface drainage system * remote sensing * image interpretation * drainage recognition and mapping Subject RIV: DJ - Water Pollution ; Quality; DE - Earth Magnetism, Geodesy, Geography (UGN-S) OBOR OECD: Environmental sciences (social aspects to be 5.7); Physical geography (UGN-S) Impact factor: 2.174, year: 2016

  15. Anticyclonic eddies increase accumulation of microplastic in the North Atlantic subtropical gyre

    NARCIS (Netherlands)

    Brach, Laurent; Deixonne, Patrick; Bernard, Marie France; Durand, Edmée; Desjean, Marie Christine; Perez, Emile; van Sebille, Erik; ter Halle, Alexandra

    2018-01-01

    There are fundamental gaps in our understanding of the fates of microplastics in the ocean, which must be overcome if the severity of this pollution is to be fully assessed. The predominant pattern is high accumulation of microplastic in subtropical gyres. Using in situ measurements from the 7th

  16. Urban drainage in Barcelona: From hazard to resource?

    Directory of Open Access Journals (Sweden)

    David Saurí

    2017-06-01

    Full Text Available Our objective in this paper is to trace the historical trajectory of urban drainage in Barcelona from the 19th century to the present highlighting the main changes in approach, from the 'everything down the drain' philosophy of the 19th century to the sustainable urban drainage systems of the early 21st century. In this trajectory we identify four main historical periods. The first period corresponds to the 'Garcia Faria Plan' of the late 19th century which initiated the construction of modern drainage in Barcelona. The second period, lasting for much of the 20th century, showed the expansion of the centralised sewer system that, however, could not solve the chronic problems of flooding and pollution created by fast urbanisation. The third period, governed by the Olympic Games of 1992 and the rehabilitation of the beach front, entailed a massive reconfiguration of the sewer system now connected to wastewater treatment plants and enhanced with a number of large underground stormwater reservoirs. Finally, since the early 2000s, urban drainage is increasingly adopting decentralised, smallscale solutions to drainage such as Sustainable Urban Drainage Systems (SUDS. While signs of the transition towards a more sustainable approach to urban drainage are already present, the conventional approach remains strong and appears to be evolving also towards more sustainable solutions. Hence, system coexistence rather than substitution appears to be the outcome of the transition in urban drainage in this city.

  17. Acid drainage (AD) in nature and environmental impact of acid mine drainage (AMD) in Southern Tuscany

    International Nuclear Information System (INIS)

    Di Lella, Luigi Antonello; Protano, Giuseppe; Riccobono, Francesco

    2005-01-01

    Acid drainage (AD) is a natural process occurring locally at the Earth's surface. It consists in a substantial increase of acidity of surface waters as a result of chemical reactions occurring in the atmosphere (i.e. acid rain) or involving reactive phases (i.e. pyrite) present in the percolated medium. Acidic surface waters (usually pH < 4) can be produced by oxidation of sulphides (mainly pyrite and other iron sulphides) exposed to atmospheric oxygen, while human activities, such as mining, can greatly enhance this process. Acid drainage promoted by mining activities is called acid mine drainage (AMD) and is a primary source of environmental pollution and a world-wide problem in both active and abandoned mining areas. In fact, exposure of iron sulphides to oxidising conditions produces strongly acidic drainage waters rich in sulphate and a variety of heavy elements (i.e. As, Cd, Pb, Sb). Several occurrences of active acid mine drainage have been found in the Metalliferous Hills (southern Tuscany). The most important AMD phenomena were observed in the Fenice Capanne and Niccioleta mining areas

  18. Predicting tile drainage discharge

    DEFF Research Database (Denmark)

    Iversen, Bo Vangsø; Kjærgaard, Charlotte; Petersen, Rasmus Jes

    More than 50 % of Danish agricultural areas are expected to be artificial tile drained. Transport of water and nutrients through the tile drain system to the aquatic environment is expected to be significant. For different mitigation strategies such as constructed wetlands an exact knowledge...... of the water load coming from the tile drainage system is therefore essential. This work aims at predicting tile drainage discharge using dynamic as well as a statistical predictive models. A large dataset of historical tile drain discharge data, daily discharge values as well as yearly average values were...... used in the analysis. For the dynamic modelling, a simple linear reservoir model was used where different outlets in the model represented tile drain as well as groundwater discharge outputs. This modelling was based on daily measured tile drain discharge values. The statistical predictive model...

  19. Percutaneous drainage of lung abscesses

    International Nuclear Information System (INIS)

    van Sonnenberg, E.; D'Agostino, H.; Casola, G.; Vatney, R.R.; Wittich, G.R.; Harker, C.

    1989-01-01

    The authors performed percutaneous drainage of lung abscesses in 12 patients. Indications for drainage were septicemia and persistence or worsening of radiographic findings. These lung abscesses were refractory to intravenous antibiotics and to bronchial toilet. Etiology of the abscesses included pneumonia (most frequently), trauma, postoperative development, infected necrotic neoplasm, and infected sequestration. Guidelines for drainage included passage of the catheter through contiguously abnormal lung and pleura, inability of the patient to cough, and/or bronchial obstruction precluding bronchial drainage. Cure was achieved in 11 of 12 patients. Catheters were removed on an average of 16 days after insertion. Antibiotics were administered an average of 18 days before drainage. No major complications occurred

  20. Evaluation of Life Cycle Assessment (LCA) for Roadway Drainage Systems.

    Science.gov (United States)

    Byrne, Diana M; Grabowski, Marta K; Benitez, Amy C B; Schmidt, Arthur R; Guest, Jeremy S

    2017-08-15

    Roadway drainage design has traditionally focused on cost-effectively managing water quantity; however, runoff carries pollutants, posing risks to the local environment and public health. Additionally, construction and maintenance incur costs and contribute to global environmental impacts. While life cycle assessment (LCA) can potentially capture local and global environmental impacts of roadway drainage and other stormwater systems, LCA methodology must be evaluated because stormwater systems differ from wastewater and drinking water systems to which LCA is more frequently applied. To this end, this research developed a comprehensive model linking roadway drainage design parameters to LCA and life cycle costing (LCC) under uncertainty. This framework was applied to 10 highway drainage projects to evaluate LCA methodological choices by characterizing environmental and economic impacts of drainage projects and individual components (basin, bioswale, culvert, grass swale, storm sewer, and pipe underdrain). The relative impacts of drainage components varied based on functional unit choice. LCA inventory cutoff criteria evaluation showed the potential for cost-based criteria, which performed better than mass-based criteria. Finally, the local aquatic benefits of grass swales and bioswales offset global environmental impacts for four impact categories, highlighting the need to explicitly consider local impacts (i.e., direct emissions) when evaluating drainage technologies.

  1. Stormwater Drainage Manual 2008

    OpenAIRE

    Burke, Christopher B.; Burke, Thomas T.

    2008-01-01

    This manual is a comprehensive catalog of procedures, design methods and criteria, and general background information which will enable the designer to quickly learn or review the basic principles of storm drainage design. Subjects included are precipitation and hydrological cycle, runoff and its estimation, open channels, flow in gutters and inlets, stormwater storage, storm sewer system design, computer applications for computing watershed runoff, and water quality. Included in the appendic...

  2. Reducing the uncertainty in subtropical cloud feedback

    Science.gov (United States)

    Myers, Timothy A.; Norris, Joel R.

    2016-03-01

    Large uncertainty remains on how subtropical clouds will respond to anthropogenic climate change and therefore whether they will act as a positive feedback that amplifies global warming or negative feedback that dampens global warming by altering Earth's energy budget. Here we reduce this uncertainty using an observationally constrained formulation of the response of subtropical clouds to greenhouse forcing. The observed interannual sensitivity of cloud solar reflection to varying meteorological conditions suggests that increasing sea surface temperature and atmospheric stability in the future climate will have largely canceling effects on subtropical cloudiness, overall leading to a weak positive shortwave cloud feedback (0.4 ± 0.9 W m-2 K-1). The uncertainty of this observationally based approximation of the cloud feedback is narrower than the intermodel spread of the feedback produced by climate models. Subtropical cloud changes will therefore complement positive cloud feedbacks identified by previous work, suggesting that future global cloud changes will amplify global warming.

  3. Light respiration by subtropical seaweeds.

    Science.gov (United States)

    Carvalho, Matheus C; Eyre, Bradley D

    2017-06-01

    Here, we report the first-ever measurements of light CO 2 respiration rate (CRR) by seaweeds. We measured the influence of temperature (15-25°C) and light (irradiance from 60 to 670 μmol · m -2  · s -1 ) on the light CCR of two subtropical seaweed species, and measured the CRR of seven different seaweed species under the same light (150 μmol · m -2  · s -1 ) and temperature (25°C). There was little effect of irradiance on light CRR, but there was an effect of temperature. Across the seven species light CRR was similar to OCR (oxygen consumption rate in the dark), with the exception of a single species. The outlier species was a coralline alga, and the higher light CRR was probably driven by calcification. CRR could be estimated from OCR, as well as carbon photosynthetic rates from oxygen photosynthetic rates, which suggests that previous studies have probably provided good estimations of gross photosynthesis for seaweeds. © 2017 Phycological Society of America.

  4. Anticyclonic eddies increase accumulation of microplastic in the North Atlantic subtropical gyre.

    Science.gov (United States)

    Brach, Laurent; Deixonne, Patrick; Bernard, Marie-France; Durand, Edmée; Desjean, Marie-Christine; Perez, Emile; van Sebille, Erik; Ter Halle, Alexandra

    2018-01-01

    There are fundamental gaps in our understanding of the fates of microplastics in the ocean, which must be overcome if the severity of this pollution is to be fully assessed. The predominant pattern is high accumulation of microplastic in subtropical gyres. Using in situ measurements from the 7th Continent expedition in the North Atlantic subtropical gyre, data from satellite observations and models, we show how microplastic concentrations were up to 9.4 times higher in an anticyclonic eddy explored, compared to the cyclonic eddy. Although our sample size is small, this is the first suggestive evidence that mesoscale eddies might trap, concentrate and potentially transport microplastics. As eddies are known to congregate nutrients and organisms, this phenomenon should be considered with regards to the potential impact of plastic pollution on the ecosystem in the open ocean. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Mine water quality deterioration due to acid mine drainage

    Science.gov (United States)

    Singh, Gurdeep

    1987-03-01

    Water quality deterioration due to acid mine drainage is of concern in the northeastern coalfield of India as the water in this area is severely polluted. The mine drainage water emanating from various collieries are highly acidic in character and contain high hardness, sulphate, total dissolved solids and iron coupled with low pH values—which further results in contamination of trace (heavy) metals at significant levels. Trace metals are highly toxic and undesirable and are injurious to human health. These acidic waters are also typically hard in character because of iron sulphate content rather than common Ca-Mg bicarbonate type hardness.

  6. Delayed drainage versus autotransfusion drainage and routine drainage after total knee arthroplasty: a comparative study

    Science.gov (United States)

    2013-01-01

    Background The purpose of this research is to compare the clinical results of different drainage methods in total knee arthroplasty (TKA). Methods This retrospective comparative study included 55 patients who accepted primary unilateral TKA between October 2010 and November 2012. The patients were classified according to the drainage method used: 25 patients in the autotransfusion drainage group, 12 patients in the delayed drainage group, and 18 patients in the routine drainage group. Otherwise, the same operative procedures and postoperative care were applied to all patients. The variables recorded included total amount of postoperative drainage (including intraoperative blood loss); cases of allogenic blood transfusion; body temperatures on postoperative days 1, 3, and 7; and pre- and postoperative hemoglobin level. Some other elements such as postoperative swelling, range of motion, and wound healing were also compared. Results Patients who underwent autotransfusion were found to have an amount of drainage (799.2 ± 196.7 mL) significantly greater than that in the routine drainage group (666.1 ± 155.0 mL), which in turn was significantly greater than that in the delayed drainage group (381.7 ± 129.2 mL). The postoperative hemoglobin level in the delayed drainage group (91.5 ± 7.9 g/L) was similar to that in the autotransfusion group (92.0 ± 9.6 g/L), while that in the routine drainage group (81.3 ± 9.9 g/L) was significantly lower. The patients in the autotransfusion group were observed to have higher body temperatures than those in the other two groups. In the routine drainage group, eight cases accepted allogenic blood transfusion, and the percentage (44.4%) was significantly higher than that in the other two groups. There were no significant between-group differences in swelling, healing qualities, and range of motion. Conclusions Delayed postoperative drainage may reduce blood loss and the chance of allogenic blood transfusion compared with routine

  7. Preoperative biliary drainage in Perihilar Cholangiocarcinoma: Identifying patients who require percutaneous drainage after failed endoscopic drainage

    Science.gov (United States)

    Wiggers, Jimme K; Koerkamp, Bas Groot; Coelen, Robert J; Rauws, Erik A; Schattner, Mark A; Nio, C Yung; Brown, Karen T; Gonen, Mithat; van Dieren, Susan; van Lienden, Krijn P; Allen, Peter J; Besselink, Marc GH; Busch, Olivier RC; D’Angelica, Michael I; DeMatteo, Robert P; Gouma, Dirk J; Kingham, T Peter; Jarnagin, William R; van Gulik, Thomas M

    2016-01-01

    Background and study aims Preoperative biliary drainage is often initiated with endoscopic retrograde cholangiopancreatography (ERCP) in patients with potentially resectable perihilar cholangiocarcinoma (PHC), but additional percutaneous transhepatic catheter (PTC) drainage is frequently required. This study aimed to develop and validate a prediction model to identify patients with a high risk of inadequate ERCP drainage. Patients and Methods Patients with potentially resectable PHC and preoperative (attempted) ERCP drainage were included from two specialty center cohorts between 2001 and 2013. Indications for additional PTC drainage were failure to place an endoscopic stent, failure to relieve jaundice, cholangitis, or insufficient drainage of the future liver remnant. A prediction model was derived from the European cohort and externally validated in the USA cohort. Results 108 of 288 patients (38%) required additional preoperative PTC after inadequate ERCP drainage. Independent risk factors for additional PTC were proximal biliary obstruction on preoperative imaging (Bismuth 3 or 4) and pre-drainage total bilirubin level. The prediction model identified three subgroups: patients with a low risk of 7%, a moderate risk of 40%, and a high risk of 62%. The high-risk group consisted of patients with a total bilirubin level above 150 μmol/L and Bismuth 3a or 4 tumours, who typically require preoperative drainage of the angulated left bile ducts. The prediction model had good discrimination (AUC 0.74) and adequate calibration in the external validation cohort. Conclusions Selected patients with potentially resectable PHC have a high risk (62%) of inadequate preoperative ERCP drainage requiring additional PTC. These patients might do better with initial PTC instead of ERCP. PMID:26382308

  8. Subsurface agricultural irrigation drainage: the need for regulation.

    Science.gov (United States)

    Lemly, A D

    1993-04-01

    Subsurface drainage resulting from irrigated agriculture is a toxic threat to fish and wildlife resources throughout the western United States. Studies by the U.S. Department of the Interior show that migratory waterfowl have been poisoned by drainwater contaminants on at least six national wildlife refuges. Allowing this poisoning to continue is a violation of the Migratory Bird Treaty Act under U.S. Federal law. Critical wetlands and waterfowl populations are threatened in both the Pacific and Central flyways. The public is also at risk and health warnings have been issued in some locations. Subsurface irrigation drainage is a complex effluent containing toxic concentrations of trace elements, salts, and nitrogenous compounds. Some of the contaminants are classified by the U.S. Environmental Protection Agency (EPA) as priority pollutants and they can be present in concentrations that exceed EPA's criteria for toxic waste. The on-farm drainage systems used to collect and transport this wastewater provide point-source identification as well as a mechanism for toxics control through the National Pollutant Discharge Elimination System (NPDES) permit process. A four-step approach is presented for dealing with irrigation drainage in an environmentally sound manner. This regulatory strategy is very similar to those commonly used for industrial discharges and includes site evaluation, contaminant reduction through NPDES, and compliance monitoring. The EPA must recognize subsurface irrigation drainage as a specific class of pollution subject to regulation under the NPDES process. Active involvement by EPA is necessary to ensure that adequate controls on this wastewater are implemented.

  9. Peritoneal Drainage Versus Pleural Drainage After Pediatric Cardiac Surgery.

    Science.gov (United States)

    Gowda, Keshava Murty Narayana; Zidan, Marwan; Walters, Henry L; Delius, Ralph E; Mastropietro, Christopher W

    2014-07-01

    We aimed to determine whether infants undergoing cardiac surgery would more efficiently attain negative fluid balance postoperatively with passive peritoneal drainage as compared to traditional pleural drainage. A prospective, randomized study including children undergoing repair of tetralogy of Fallot (TOF) or atrioventricular septal defect (AVSD) was completed between September 2011 and June 2013. Patients were randomized to intraoperative placement of peritoneal catheter or right pleural tube in addition to the requisite mediastinal tube. The primary outcome measure was fluid balance at 48 hours postoperatively. Variables were compared using t tests or Fisher exact tests as appropriate. A total of 24 patients were enrolled (14 TOF and 10 AVSD), with 12 patients in each study group. Mean fluid balance at 48 hours was not significantly different between study groups, -41 ± 53 mL/kg in patients with periteonal drainage and -9 ± 40 mL/kg in patients with pleural drainage (P = .10). At 72 hours however, postoperative fluid balance was significantly more negative with peritoneal drainage, -52.4 ± 71.6 versus +2.0 ± 50.6 (P = .04). On subset analysis, fluid balance at 48 hours in patients with AVSD was more negative with peritoneal drainage as compared to pleural, -82 ± 51 versus -1 ± 38 mL/kg, respectively (P = .02). Fluid balance at 48 hours in patients with TOF was not significantly different between study groups. Passive peritoneal drainage may more effectively facilitate negative fluid balance when compared to pleural drainage after pediatric cardiac surgery, although this benefit is not likely universal but rather dependent on the patient's underlying physiology. © The Author(s) 2014.

  10. Seasonality of macroalgal communities in a subtropical drainage basin in Paraná state, southern Brazil.

    Science.gov (United States)

    Branco, C C Z; Krupek, R A; Peres, C K

    2008-11-01

    Seasonal dynamics of macroalgal communities was analyzed monthly by samplings in three stream segments of the Pedras River Basin, mid-south region of Paraná State, southern Brazil, from April 2004 to March 2005. The seasonal fluctuations in macroalgal species richness and abundance were correlated with selected environmental variables. In general, the seasonal distribution patterns of these communities were distinct from those reported from other tropical and temperate regions, with higher macroalgal richness and abundance observed from late spring to late fall. Multiple linear regression analysis revealed that the stream variable most closely related with the temporal distribution pattern observed was temperature, which had a very similar seasonal pattern to the biological parameters. On the other hand, the floristic composition was quite diverse in the streams sampled. Among the 25 taxa identified, only two were common to the three streams whereas 15 were restricted to a single sampling site. These data indicate that, although temperature seems to be an effective relationship with global temporal pattern, particular characteristics of each stream can strongly influence the seasonal tendencies in local scale. The results of Detrended Correspondence Analysis (DCA) and Cluster Analysis corroborated this observation.

  11. Seasonality of macroalgal communities in a subtropical drainage basin in Paraná state, southern Brazil

    Directory of Open Access Journals (Sweden)

    CCZ. Branco

    Full Text Available Seasonal dynamics of macroalgal communities was analyzed monthly by samplings in three stream segments of the Pedras River Basin, mid-south region of Paraná State, southern Brazil, from April 2004 to March 2005. The seasonal fluctuations in macroalgal species richness and abundance were correlated with selected environmental variables. In general, the seasonal distribution patterns of these communities were distinct from those reported from other tropical and temperate regions, with higher macroalgal richness and abundance observed from late spring to late fall. Multiple linear regression analysis revealed that the stream variable most closely related with the temporal distribution pattern observed was temperature, which had a very similar seasonal pattern to the biological parameters. On the other hand, the floristic composition was quite diverse in the streams sampled. Among the 25 taxa identified, only two were common to the three streams whereas 15 were restricted to a single sampling site. These data indicate that, although temperature seems to be an effective relationship with global temporal pattern, particular characteristics of each stream can strongly influence the seasonal tendencies in local scale. The results of Detrended Correspondence Analysis (DCA and Cluster Analysis corroborated this observation.

  12. The effect of climate change on urban drainage

    DEFF Research Database (Denmark)

    Grum, M.; Jørgensen, A.T.; Johansen, R.M.

    2006-01-01

    That we are in a period of extraordinary rates of climate change is today evident. These climate changes are likely to impact local weather conditions with direct impacts on precipitation patterns and urban drainage. In recent years several studies have focused on revealing the nature, extent and...... to urban drainage. However, in spite of these uncertainties, and others raised in the discussion, the tendency is clear: extreme precipitation events effecting urban drainage and causing flooding will become more frequent as a result of climate change.......That we are in a period of extraordinary rates of climate change is today evident. These climate changes are likely to impact local weather conditions with direct impacts on precipitation patterns and urban drainage. In recent years several studies have focused on revealing the nature, extent...... and consequences of climate change on urban drainage and urban runoff pollution issues. This study uses predictions from a regional climate model to look at the effects of climate change on extreme precipitation events. Results are presented in terms of point rainfall extremes. The analysis involves three steps...

  13. Drainage from coal mines: Chemistry and environmental problems

    International Nuclear Information System (INIS)

    Wildeman, T.

    1991-01-01

    Much of the research on coal-mine drainage chemistry was conducted a decade ago, and now increased environmental awareness has brought about renewed interest in the findings. Consideration of the trace minerals and elements in coal points to the possible generation of acidic waters upon weathering, especially when pyrite is present. When pyrite weathers, it produces H + and Fe 3+ which catalyze the incongruent weathering of other carbonates and sulfides. In this weathering mechanism, catalysis by bacteria is important. Of the environmental problems in coal mine drainage, the mineral acidity of the water is the most serious. This is caused not only by the H + , but also by Mn 4+ , Fe 3+ , and Al 3+ that are found or generated within the drainage. Case studies in Kentucky, Pennsylvania, Illinois, and Colorado show that the abundance and form of pyrite in the deposit and in the overburden determines the level of acidity and the concentration of heavy metal pollutants in the drainage. Recent trends in environmental enforcement that emphasize integrated stream water standards and biotoxicity assays point to the possibility that the concentrations of heavy metals in coal mine drainages may cause environmental concern

  14. Water pollution by agriculture

    OpenAIRE

    Moss, Brian

    2007-01-01

    Agriculture disrupts all freshwater systems hugely from their pristine states. The former reductionist concept of pollution was of examining individual effects of particular substances on individual taxa or sub-communities in freshwater systems, an essentially ecotoxicological concept. It is now less useful than a more holistic approach that treats the impacts on the system as a whole and includes physical impacts such as drainage and physical modification of river channels and modification o...

  15. Pesticide Pollution in Ecosystems

    OpenAIRE

    İlter, Hüseyin; Kurt, Burak; Ötegen, Volkan Recai; Akbaba, Muhsin

    2018-01-01

    Pesticidepollution affects both aquatic and soil ecosystems. Factors that promotepesticide pollution include drainage patterns, properties of the pesticide,rainfall, microbial activity, treatment surface and rate of application.Pesticides are able to move from one ecosystem to another through processessuch as transfer (mobility) and transformation (degradation). Transfer mayoccur through surface runoff, vapourization to atmosphere, sorption (adsorp‐tion/desorp-tion), plant uptakeor soil water...

  16. Results of percutaneous abscess drainage

    International Nuclear Information System (INIS)

    Daehnert, W.; Guenther, R.; Klose, K.; Gamstaetter, G.

    1983-01-01

    Between 1978 and 1983 fifty-two abdominal abscesses in 44 patients were drained percutaneously, 79% of the abscesses occurred as postoperative complications. The overall success rate was 60%, whereas only 42% of left subphrenic abscesses were cured. Complications were encountered in 4.5%. Reasons for drainage failures were: liver sequestration, loculation, fistulae and recurrences. Percutaneous abscess drainage in an alternative, and valuable addition, to surgery. (orig.) [de

  17. Tile Drainage Density Reduces Groundwater Travel Times and Compromises Riparian Buffer Effectiveness.

    Science.gov (United States)

    Schilling, Keith E; Wolter, Calvin F; Isenhart, Thomas M; Schultz, Richard C

    2015-11-01

    Strategies to reduce nitrate-nitrogen (nitrate) pollution delivered to streams often seek to increase groundwater residence time to achieve measureable results, yet the effects of tile drainage on residence time have not been well documented. In this study, we used a geographic information system groundwater travel time model to quantify the effects of artificial subsurface drainage on groundwater travel times in the 7443-ha Bear Creek watershed in north-central Iowa. Our objectives were to evaluate how mean groundwater travel times changed with increasing drainage intensity and to assess how tile drainage density reduces groundwater contributions to riparian buffers. Results indicate that mean groundwater travel times are reduced with increasing degrees of tile drainage. Mean groundwater travel times decreased from 5.6 to 1.1 yr, with drainage densities ranging from 0.005 m (7.6 mi) to 0.04 m (62 mi), respectively. Model simulations indicate that mean travel times with tile drainage are more than 150 times faster than those that existed before settlement. With intensive drainage, less than 2% of the groundwater in the basin appears to flow through a perennial stream buffer, thereby reducing the effectiveness of this practice to reduce stream nitrate loads. Hence, strategies, such as reconnecting tile drainage to buffers, are promising because they increase groundwater residence times in tile-drained watersheds. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  18. Nitrate source apportionment in a subtropical watershed using Bayesian model

    International Nuclear Information System (INIS)

    Yang, Liping; Han, Jiangpei; Xue, Jianlong; Zeng, Lingzao; Shi, Jiachun; Wu, Laosheng; Jiang, Yonghai

    2013-01-01

    Nitrate (NO 3 − ) pollution in aquatic system is a worldwide problem. The temporal distribution pattern and sources of nitrate are of great concern for water quality. The nitrogen (N) cycling processes in a subtropical watershed located in Changxing County, Zhejiang Province, China were greatly influenced by the temporal variations of precipitation and temperature during the study period (September 2011 to July 2012). The highest NO 3 − concentration in water was in May (wet season, mean ± SD = 17.45 ± 9.50 mg L −1 ) and the lowest concentration occurred in December (dry season, mean ± SD = 10.54 ± 6.28 mg L −1 ). Nevertheless, no water sample in the study area exceeds the WHO drinking water limit of 50 mg L −1 NO 3 − . Four sources of NO 3 − (atmospheric deposition, AD; soil N, SN; synthetic fertilizer, SF; manure and sewage, M and S) were identified using both hydrochemical characteristics [Cl − , NO 3 − , HCO 3 − , SO 4 2− , Ca 2+ , K + , Mg 2+ , Na + , dissolved oxygen (DO)] and dual isotope approach (δ 15 N–NO 3 − and δ 18 O–NO 3 − ). Both chemical and isotopic characteristics indicated that denitrification was not the main N cycling process in the study area. Using a Bayesian model (stable isotope analysis in R, SIAR), the contribution of each source was apportioned. Source apportionment results showed that source contributions differed significantly between the dry and wet season, AD and M and S contributed more in December than in May. In contrast, SN and SF contributed more NO 3 − to water in May than that in December. M and S and SF were the major contributors in December and May, respectively. Moreover, the shortcomings and uncertainties of SIAR were discussed to provide implications for future works. With the assessment of temporal variation and sources of NO 3 − , better agricultural management practices and sewage disposal programs can be implemented to sustain water quality in subtropical watersheds

  19. Particle Pollution

    Science.gov (United States)

    ... Your Health Particle Pollution Public Health Issues Particle Pollution Recommend on Facebook Tweet Share Compartir Particle pollution — ... see them in the air. Where does particle pollution come from? Particle pollution can come from two ...

  20. Review on the quality of sediments from the stormwater drainage system in the urban area

    Directory of Open Access Journals (Sweden)

    Nawrot Nicole

    2017-01-01

    Full Text Available The main task of the stormwater drainage system (SDS is a safe drainage of rainwater and snowmelt from the urban area to the receiver. The flow of rain water in the drainage pipes is directly related with the formation of sediments in the whole stormwater system. In addition, pollutants from land runoff get adsorbed to the sediments. The sludge is mainly formed in those elements of SDS, wherein the flow conditions allow for sedimentation. This article provides an overview of the literature concerning the characteristics of sediments from SDS, with a particular focus on heavy metals in sediments deposited in the urban catchment area.

  1. Percutaneous drainage of tuberculous abscesses

    International Nuclear Information System (INIS)

    Puri, S.K.; Panicker, H.; Narang, P.; Kumar, N.; Dhall, A.; Gupta, S.B.

    2001-01-01

    To assess the role of percutaneous catheter drainage (PCD) in the management of tuberculous ilio-psoas abscesses, twenty-two patients with 26 tuberculous ilio-psoas abscesses were subjected to PCD under real time US guidance taking help of a pre-procedure CT for planning the route of catheter insertion. Complete cure of the ilio-psoas abscesses could be achieved in 22 of 26 abscesses (84.6%). Average duration of drainage was 10 days. US/ CT follow-up ranged from 3-24 months. PCD was a failure in four abscesses (15.4%). Two patients, one with bilateral abscesses, had recurrent abscesses while one patient had an abscess associated with extensive spondylo-discitis. No significant complication was encountered in the study. PCD is a simple, safe and very effective (success rate 84.6%) alternative to surgical drainage in the management of tuberculous ilio-psoas abscesses. (author)

  2. Technical note on drainage systems

    DEFF Research Database (Denmark)

    Bentzen, Thomas Ruby

    note is divided into four main topics: First, a short review of the precipitation in Denmark as well as how historical (actual) rainfall data can be used advantageously to those simple design methods, then how pipelines and reservoirs can be dimensioned and finally how safety in the design can......This technical note will present simple but widely used methods for the design of drainage systems. The note will primarily deal with surface water (rainwater) which on a satisfactorily way should be transport into the drainage system. Traditional two types of sewer systems exist: A combined system...

  3. Subsurface lateral flow from hillslope and its contribution to nitrate loading in streams through an agricultural catchment during subtropical rainstorm events

    Directory of Open Access Journals (Sweden)

    B. Zhang

    2011-10-01

    Full Text Available Subsurface lateral flow from agricultural hillslopes is often overlooked compared with overland flow and tile drain flow, partly due to the difficulties in monitoring and quantifying. The objectives of this study were to examine how subsurface lateral flow generated through soil pedons from cropped hillslopes and to quantify its contribution to nitrate loading in the streams through an agricultural catchment in the subtropical region of China. Profiles of soil water potential along hillslopes and stream hydro-chemographs in a trenched stream below a cropped hillslope and at the catchment outlet were simultaneously recorded during two rainstorm events. The dynamics of soil water potential showed positive matrix soil water potential over impermeable soil layer at 0.6 to 1.50 m depths during and after the storms, indicating soil water saturation and drainage processes along the hillslopes irrespective of land uses. The hydro-chemographs in the streams, one trenched below a cropped hillslope and one at the catchment outlet, showed that the concentrations of particulate nitrogen and phosphorus corresponded well to stream flow during the storm, while the nitrate concentration increased on the recession limbs of the hydrographs after the end of the storm. All the synchronous data revealed that nitrate was delivered from the cropped hillslope through subsurface lateral flow to the streams during and after the end of the rainstorms. A chemical mixing model based on electricity conductivity (EC and H+ concentration was successfully established, particularly for the trenched stream. The results showed that the subsurface lateral flow accounted for 29% to 45% of total stream flow in the trenched stream, responsible for 86% of total NO3-N loss (or 26% of total N loss, and for 5.7% to 7.3% of total stream flow at the catchment outlet, responsible for about 69% of total NO3-N loss (or 28% of total N

  4. Pollution from Urban Stormwater Infiltration

    DEFF Research Database (Denmark)

    Mikkelsen, Peter Steen; Weyer, G.; Berry, C.

    1994-01-01

    Stormwater infiltration in urban areas gives cause for concern with regard to the risk of soil and groundwater pollution. Compared with conventional storm drainage, infiltration introduces different and widely unknown conditions governing the impacts and the fate of the pollutants......, and it is therefore difficult to assess the overall environmental impact. This paper gives a state of the art assessment of the water quality aspects of stormwater infiltration and proposes ways of managing the inherent problems. The major stormwater pollution sources are highlighted and the different processes...

  5. Atmospheric pollution; Pollution atmospherique

    Energy Technology Data Exchange (ETDEWEB)

    Lambrozo, J.; Guillossou, G. [EDF-Gas de France, Service des Etudes Medicales, 75 - Paris (France)

    2008-10-15

    The atmosphere is the reservoir of numerous pollutants (nitrogen oxides, sulfur oxides, carbon oxides, particulates, volatile organic compounds, polycyclic aromatic hydrocarbons) from natural origin or anthropogenic origin ( industry, transport, agriculture, district heating). With epidemiologic studies the atmospheric pollution is associated with an increase of respiratory and cardiovascular diseases. At the european level, the technological progress, the legislation have allowed a reduction of pollutant emissions, however these efforts have to be continued because the sanitary impact of atmospheric pollution must not be underestimated, even if the risks appear less important that these ones in relation with tobacco, inside pollution or others factors of cardiovascular risks. Indeed, on these last factors an individual action is possible for the exposure to air pollution people have no control. (N.C.)

  6. in remediating acid mine drainage

    African Journals Online (AJOL)

    The management and treatment of contaminated mine water is one of the most urgent problems facing the South African mining industry. The cost advantage of permeable reactive barriers (PRBs) has seen their increased application as means of passively treating mine drainage. A PRB is built by placing a reactive material ...

  7. The study of azaarene behavior over atmosphere of subtropical city(Keelung)

    Science.gov (United States)

    Liu, Chih Yun

    2017-04-01

    In this study, we collected the Total Suspended Particulates (TSP) from July 2014 to February 2016 in the subtropical city (Keelung), and researched azaarene behavior over atmosphere. Polycyclic Aromatic Compounds (PAHs) are ubiquitous pollutants in the environment; they have known carcinogens and/or mutagens, mainly produce from incomplete combustion. Azaarenes are polycyclic aromatic hydrocarbon derivative compounds in which a carbon atom in one of the aromatic rings is substituted by a nitrogen atom. Organism exposure to azaarenes occurs through inhalation of polluted air and by ingestion of food and/or water containing combustion products and accumulate in the body. Total azaarene concentration (16 individual compound concentration of the aggregate) is between 0.92 to 3.76 μg/m3, results showed that the concentration of azaarenes have significant seasonal variation, they have higher concentration in the cold month. In molecular weight, the highest proportion is the molecular weight equal to 143(ΣMQ) and then the molecular weight equal to 179(BAP), ΣMQ would rise from 30% 40% to 40% 50% during the cold month and warm months. Compared to ring number, 2-rings are biggest part, the smallest is 4-rings, its ratio has slight variation, but primary species is 2-rings. Emissions from transportation, local housing heating, factories burning fossil fuels and dust from Mainland south air mass are pollutant, their sources and climate conditions can affect concentration and composition of compound. There are highly significant correlation between 3-rings and 4-rings, which suggests that there are similar source strengths and transport mechanisms for these compounds. Correlation between concentration of azaarenes and ambient temperature is negative moderation, with concentration of atmospheric suspended particles is positive moderate correlation. Finally, we establish the relationship between the three parameters to predict concentration of azaarenes over atmosphere of

  8. Anthropogenic forcing of estuarine hypoxic events in sub-tropical catchments: landscape drivers and biogeochemical processes.

    Science.gov (United States)

    Wong, Vanessa N L; Johnston, Scott G; Burton, Edward D; Bush, Richard T; Sullivan, Leigh A; Slavich, Peter G

    2011-11-15

    Episodic hypoxic events can occur following summer floods in sub-tropical estuaries of eastern Australia. These events can cause deoxygenation of waterways and extensive fish mortality. Here, we present a conceptual model that links key landscape drivers and biogeochemical processes which contribute to post-flood hypoxic events. The model provides a framework for examining the nature of anthropogenic forcing. Modification of estuarine floodplain surface hydrology through the construction of extensive drainage networks emerges as a major contributing factor to increasing the frequency, magnitude and duration of hypoxic events. Forcing occurs in two main ways. Firstly, artificial drainage of backswamp wetlands initiates drier conditions which cause a shift in vegetation assemblages from wetland-dominant species to dryland-dominant species. These species, which currently dominate the floodplain, are largely intolerant of inundation and provide abundant labile substrate for decomposition following flood events. Decomposition of this labile carbon pool consumes oxygen in the overlying floodwaters, and results in anoxic conditions and waters with excess deoxygenation potential (DOP). Carbon metabolism can be strongly coupled with microbially-mediated reduction of accumulated Fe and Mn oxides, phases which are common on these coastal floodplain landscapes. Secondly, artificial drainage enhances discharge rates during the flood recession phase. Drains transport deoxygenated high DOP floodwaters rapidly from backswamp wetlands to the main river channel to further consume oxygen. This process effectively displaces the natural carbon metabolism processes from floodplain wetlands to the main channel. Management options to reduce the impacts of post-flood hypoxia include i) remodifying drainage on the floodplain to promote wetter conditions, thereby shifting vegetation assemblages towards inundation-tolerant species, and ii) strategic retention of floodwaters in the backswamp

  9. Definition of the drainage filter problem

    NARCIS (Netherlands)

    Zaslavsky, D.

    1977-01-01

    It is common to consider the following: I. Retention of soil particles that may enter the drainage pipe and cause its clogging. For some sensitive structures it is important to prevent settlements due to soil transportation by drainage water.

  10. 33 CFR 155.400 - Platform machinery space drainage on oceangoing fixed and floating drilling rigs and other...

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Platform machinery space drainage on oceangoing fixed and floating drilling rigs and other platforms. 155.400 Section 155.400 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) POLLUTION OIL OR HAZARDOUS MATERIAL POLLUTION PREVENTION REGULATION...

  11. Solid Waste in Drainage Network of Rio do Meio Watershed, Florianópolis/SC

    Directory of Open Access Journals (Sweden)

    Taiana Gava

    2012-12-01

    Full Text Available The urban drainage network is among the main pollution transport load factors. Researches on the identification of solid waste transported in the drainage network have been considered the allow evaluation of its impact. In this paper we analyze the main characteristics that influences the presence of solid wastes in the drainage network of the Rio do Meio basin, Florianópolis/SC. A metal net was installed in selected river section and monitored after each rain event. The results showed about 0.27 kg/ha.year of waste are carried in the drainage network. The majority being composed of plastics and building materials. Through the analysis of the data, it was possible to verify the presence of waste in the drainage network is due to poor packaging and to the lack of sweeping in some parts of the basin. It was also found that the total precipitation is directly proportional to the appearance of solid waste. It was concluded that the lack of an integrated management between the components of sanitary system leave unnoticed simple structural measures that ultimately decrease the amount of solid waste in the drainage basin, and that could eliminate this source of pollution.

  12. 49 CFR 213.319 - Drainage.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Drainage. 213.319 Section 213.319 Transportation... TRANSPORTATION TRACK SAFETY STANDARDS Train Operations at Track Classes 6 and Higher § 213.319 Drainage. Each drainage or other water carrying facility under or immediately adjacent to the roadbed shall be maintained...

  13. 49 CFR 213.33 - Drainage.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Drainage. 213.33 Section 213.33 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION TRACK SAFETY STANDARDS Roadbed § 213.33 Drainage. Each drainage or other water carrying facility...

  14. Drainage under increasing and changing requirements

    NARCIS (Netherlands)

    Schultz, E.; Zimmer, D.; Vlotman, W.F.

    2007-01-01

    This year the Working Group on Drainage of the International Commission on Irrigation and Drainage (ICID) celebrates its 25th anniversary. This paper reviews the development of drainage for three different agro-climatic zones, i.e. the temperate (humid), the arid/semi-arid and the humid/semi-humid

  15. Diatoms as biomonitors in two temporary streams affected by acid drainage from disused mines

    International Nuclear Information System (INIS)

    Ferris, J.M.; Brown, P.L.; Vyverman, W.; Gell, P.

    2002-01-01

    Diatoms are increasingly used as biomonitors of water quality in Australia, partly as an extension of the AUSRIVAS concept and partly through the increasing emphasis on biological/ecological monitoring of stream health that is acknowledged in the Australian and New Zealand water quality guidelines (ANZECC and ARMCANZ, 2000). This work brings together the findings of three studies relating diatom populations to the water chemistry of two temporary streams affected by acid drainage. In the three studies reported, changes in the benthic diatom flora have been successfully used to: show the toxic effects of acid drainage from two mine sites; differentiate between nutrient and acid drainage pollution in a stream system affected by more than one pollutant and provide independent corroboration of the AQUARISK ecological risk assessment code

  16. Macroinvertebrate community response to acid mine drainage in rivers of the High Andes (Bolivia).

    NARCIS (Netherlands)

    Damme, P.A. van; Hamel, C.; Ayala, A.; Bervoets, L.

    2008-01-01

    Several High Andes Rivers are characterized by inorganic water pollution known as acid mine drainage (AMD). The aim of this study was to assess the relationship between metal concentrations in the sediments and the macroinvertebrate communities in two river basins affected by AMD. In general, the

  17. Influence of mine drainage on water quality along River Nyaba in ...

    African Journals Online (AJOL)

    ELO

    Drainage from underground coal mines, surface mines and coal refuse piles is the oldest industrial pollution in the Enugu coal area which is characterized by numerous surface water, hand dug wells and shallow unconfined aquifer and as such the water sources are prone to con- tamination from coal mining activities.

  18. Mercury in tropical and subtropical coastal environments

    Science.gov (United States)

    Costa, Monica F.; Landing, William M.; Kehrig, Helena A.; Barletta, Mário; Holmes, Christopher D.; Barrocas, Paulo R. G.; Evers, David C.; Buck, David G.; Vasconcellos, Ana Claudia; Hacon, Sandra S.; Moreira, Josino C.; Malm, Olaf

    2012-01-01

    Anthropogenic activities influence the biogeochemical cycles of mercury, both qualitatively and quantitatively, on a global scale from sources to sinks. Anthropogenic processes that alter the temporal and spatial patterns of sources and cycling processes are changing the impacts of mercury contamination on aquatic biota and humans. Human exposure to mercury is dominated by the consumption of fish and products from aquaculture operations. The risk to society and to ecosystems from mercury contamination is growing, and it is important to monitor these expanding risks. However, the extent and manner to which anthropogenic activities will alter mercury sources and biogeochemical cycling in tropical and sub-tropical coastal environments is poorly understood. Factors as (1) lack of reliable local/regional data; (2) rapidly changing environmental conditions; (3) governmental priorities and; (4) technical actions from supra-national institutions, are some of the obstacles to overcome in mercury cycling research and policy formulation. In the tropics and sub-tropics, research on mercury in the environment is moving from an exploratory “inventory” phase towards more process-oriented studies. Addressing biodiversity conservation and human health issues related to mercury contamination of river basins and tropical coastal environments are an integral part of paragraph 221 paragraph of the United Nations document “The Future We Want” issued in Rio de Janeiro in June 2012. PMID:22901765

  19. Integrated urban drainage, status and perspectives.

    Science.gov (United States)

    Harremoës, P

    2002-01-01

    This paper summarises the status of urban storm drainage as an integrated professional discipline, including the management-policy interface, by which the goals of society are implemented. The paper assesses the development of the discipline since the INTERURBA conference in 1992 and includes aspects of the papers presented at the INTERURBA-II conference in 2001 and the discussions during the conference. Tools for integrated analysis have been developed, but there is less implementation than could be expected. That is due to lack of adequate knowledge about important mechanisms, coupled with a significant conservatism in the business. However, significant integrated analyses have been reported. Most of them deal with the sewer system and the treatment plant, while few incorporate the receiving water as anything but the object of the loads to be minimised by engineering measures up-stream. Important measures are local infiltration, source control, storage basins, local treatment and real time control. New paradigms have been introduced: risk of pollution due to system failure, technology for water reuse, sustainability, new architecture and greener up-stream solutions as opposed to down-stream concrete solutions. The challenge is to combine the inherited approaches with the new approaches by flexibility and adaptability.

  20. Origin of acid mine drainage in Enugu

    International Nuclear Information System (INIS)

    Uma, K.O.

    1992-01-01

    Mine flooding is a serious problem in the Enugu Coal Mines and has led to the abandonment of two of the four mines. About 1800 m 3 of water is pumped out daily from the mines into the nearby streams. The source of this enormous volume of water has been established based on the hydrodynamics and hydrology of the area. Two prolific aquifers - an unconfined and a confined system - overlie the mines, but the mine water is derived principally from the unconfined aquifer. The pathway of flow is, provided by the numerous fractures connecting the two aquifers and the mine tunnel. The major hydrochemical activity resulting in pollution of the mine water occurs within the sumps in the floor of the longwalls. These sumps act as oxidation chambers where groundwater from the fractures mixes and subsequently reacts with sulfur-rich solutes released by coal mining. Contrary to general belief, the mine drainage has not seriously degraded the chemistry of receiving streams. The pH and electric conductivity, representing, the dissolved ions, were increased less than 10% of the values in the unaffected region

  1. Using diatom indices for water quality assessment in a subtropical river, China.

    Science.gov (United States)

    Tan, Xiang; Sheldon, Fran; Bunn, Stuart E; Zhang, Quanfa

    2013-06-01

    Diatoms have been regularly used as bioindicators to assess water quality of surface waters. However, diatom-based indices developed for a specific geographic region may not be appropriate elsewhere. We sampled benthic diatom assemblages in the upper Han River, a subtropical river in China, to evaluate applicability of 14 diatom-based indices used worldwide for water quality assessment. A total of 194 taxa from 31 genera were identified in the dry season and 139 taxa from 23 genera in the wet season. During the dry season, significant relationships were found for all but one of the diatom-based indices (Index Diatom Artois-Picardie) with one or more physical and chemical variables including nutrients and ion concentrations in river waters. The Biological Diatom Index (IBD) and diatom-based eutrophication/pollution index (EPI-D) were strongly related to trophic status and ionic content, while Watanabe's Index was related to organic pollution and conductivity. Yet, the diatom indices showed weak relationships with physical and chemical variables during the wet season. It suggests that diatom-based indices developed in Europe can be applied with confidence as bioindicators of water quality in subtropical rivers of China, at least during base-flow conditions.

  2. Acid mine drainage in Australia: its extent and potential future liability. Supervising Scientist Report 125

    International Nuclear Information System (INIS)

    Harries, J.

    1997-01-01

    In order to better understand the impact of acid drainage in Australia and to provide a basis for assessing long-term management options, the Office of the Supervising Scientist (OSS) and the Australian Centre for Minesite Rehabilitation Research (ACMRR) initiated this study to prepare a status report on acid mine drainage in Australia. The study is supported by the Minerals Council of Australia. The coverage of this study includes all mine sites where sulphidic oxidation in mine wastes or mine workings leads to the release of contaminated drainage with off-site impacts. The objectives of the study were: 1. to quantify and characterise the generation of contaminated drainage by sulphidic oxidation from historic and current mining activities in Australia; 2. to develop a classification scheme to characterise the potential for off-site impacts from sulphidic oxidation in mine wastes; 3. to compare the cost at the national level of managing sulphidic oxidation in mine wastes and any resulting contaminated drainage with other mining and environmental costs; 4. to make recommendations based on the information received to improve the understanding and management of acid mine drainage in Australia. Information was collected on the extent and management of sulphidic oxidation and acid drainage at operating, historic and derelict mines in Australia. Mining operators, environmental officers, industry representatives, state government departments and others were asked about their experience with acid mine drainage and how it is currently managed at operating and historic mine sites. Based on the information collected, the additional cost of managing potentially acid generating wastes at operating mine sites is estimated to be about AUD 60 million per year. Potentially, the financial risk could be much greater if sulphide oxidation and release of pollutants is discovered after mine closure, as was the case for historic sites like Mt Lyell, Rum Jungle or Mt Morgan. The

  3. Water pollution by agriculture.

    Science.gov (United States)

    Moss, Brian

    2008-02-12

    Agriculture disrupts all freshwater systems hugely from their pristine states. The former reductionist concept of pollution was of examining individual effects of particular substances on individual taxa or sub-communities in freshwater systems, an essentially ecotoxicological concept. It is now less useful than a more holistic approach that treats the impacts on the system as a whole and includes physical impacts such as drainage and physical modification of river channels and modification of the catchment as well as nutrient, particulate and biocide pollution. The European Water Framework Directive implicitly recognizes this in requiring restoration of water bodies to 'good ecological quality', which is defined as only slightly different from pristine state. The implications for the management of agriculture are far more profound than is currently widely realized.

  4. Can controlled drainage control agricultural nutrient emissions? Evidence from a BACI experiment combined with a dual isotope approach

    DEFF Research Database (Denmark)

    Carstensen, Mette Vodder; Poulsen, Jane Rosenstand; Ovesen, Niels Bering

    2016-01-01

    and reduce drain outflow and nitrate loss, which were reduced by 38–52 % (97–127 mm) and 36–48 % (6–8 kg nitrate-N ha−1) relative to conventional drainage levels, respectively. Controlled drainage did not appear to influence harvest yield or cause pollution swapping as the loss of total phosphorous...... at the impacted plots, except during one event where a pronounced decline in nitrate concentrations and ceased drain flow was observed....

  5. Extreme weather: Subtropical floods and tropical cyclones

    Science.gov (United States)

    Shaevitz, Daniel A.

    Extreme weather events have a large effect on society. As such, it is important to understand these events and to project how they may change in a future, warmer climate. The aim of this thesis is to develop a deeper understanding of two types of extreme weather events: subtropical floods and tropical cyclones (TCs). In the subtropics, the latitude is high enough that quasi-geostrophic dynamics are at least qualitatively relevant, while low enough that moisture may be abundant and convection strong. Extratropical extreme precipitation events are usually associated with large-scale flow disturbances, strong ascent, and large latent heat release. In the first part of this thesis, I examine the possible triggering of convection by the large-scale dynamics and investigate the coupling between the two. Specifically two examples of extreme precipitation events in the subtropics are analyzed, the 2010 and 2014 floods of India and Pakistan and the 2015 flood of Texas and Oklahoma. I invert the quasi-geostrophic omega equation to decompose the large-scale vertical motion profile to components due to synoptic forcing and diabatic heating. Additionally, I present model results from within the Column Quasi-Geostrophic framework. A single column model and cloud-revolving model are forced with the large-scale forcings (other than large-scale vertical motion) computed from the quasi-geostrophic omega equation with input data from a reanalysis data set, and the large-scale vertical motion is diagnosed interactively with the simulated convection. It is found that convection was triggered primarily by mechanically forced orographic ascent over the Himalayas during the India/Pakistan flood and by upper-level Potential Vorticity disturbances during the Texas/Oklahoma flood. Furthermore, a climate attribution analysis was conducted for the Texas/Oklahoma flood and it is found that anthropogenic climate change was responsible for a small amount of rainfall during the event but the

  6. Water Pollution

    Science.gov (United States)

    Bowen, H. J. M.

    1975-01-01

    Deals with water pollution in the following categories: a global view, self purification, local pollution, difficulties in chemical analysis, and remedies for water pollution. Emphasizes the extent to which man's activities have modified the cycles of certain elements. (GS)

  7. Air Pollution

    OpenAIRE

    Appleton, Bonnie Lee, 1948-2012; Koci, Joel; Harris, Roger; Sevebeck, Kathryn P.; Alleman, Dawn; Swanson, Lynette

    2009-01-01

    This publication reviews the major phytotoxic air pollutants, in decreasing order of severity, they include oxidants, sulfur dioxide, and particulates. Topics also include the connection between weather and air pollution and a section on diagnosing air pollution damage to trees.

  8. Air Pollution

    Science.gov (United States)

    Air pollution is a mixture of solid particles and gases in the air. Car emissions, chemicals from factories, dust, pollen and ... Ozone, a gas, is a major part of air pollution in cities. When ozone forms air pollution, ...

  9. Ammonia-nitrogen removal from urban drainage using modified fresh empty fruit bunches: A case study in Kota Kinabalu, Sabah

    Science.gov (United States)

    Ricky, L. N. S.; Shahril, Y.; Nurmin, B.; Zahrim, AY

    2016-06-01

    Highly concentration of ammonia nitrogen in urban drainage could pollute the river and give pungent smell. The strong pungent odours that coming out from the urban drainage may degrade the image a city and could possibly reduce the present of tourist. To minimize the presence of pungent odours, the ammonia nitrogen can be removed from the urban drainage by applying proper adsorbent. In this study, an adsorbent produced through chemical modification of fresh empty fruit bunch (EFB) fibers has been carried out. The maximum adsorption capacity is between 0.01-0.60 mg/g. The finding also shows that the retention time is vital when designing ammonia nitrogen filter.

  10. Mine Drainage Generation and Control Options.

    Science.gov (United States)

    Wei, Xinchao; Rodak, Carolyn M; Zhang, Shicheng; Han, Yuexin; Wolfe, F Andrew

    2016-10-01

    This review provides a snapshot of papers published in 2015 relevant to the topic of mine drainage generation and control options. The review is broken into 3 sections: Generation, Prediction and Prevention, and Treatment Options. The first section, mine drainage generation, focuses on the characterization of mine drainage and the environmental impacts. As such, it is broken into three subsections focused on microbiological characterization, physiochemical characterization, and environmental impacts. The second section of the review is divided into two subsections focused on either the prediction or prevention of acid mine drainage. The final section focuses on treatment options for mine drainage and waste sludge. The third section contains subsections on passive treatment, biological treatment, physiochemical treatment, and a new subsection on beneficial uses for mine drainage and treatment wastes.

  11. Pollution from Urban Stormwater Infiltration

    DEFF Research Database (Denmark)

    Mikkelsen, Peter Steen; Weyer, G.; Berry, C.

    1994-01-01

    Stormwater infiltration in urban areas gives cause for concern with regard to the risk of soil and groundwater pollution. Compared with conventional storm drainage, infiltration introduces different and widely unknown conditions governing the impacts and the fate of the pollutants, and it is ther......Stormwater infiltration in urban areas gives cause for concern with regard to the risk of soil and groundwater pollution. Compared with conventional storm drainage, infiltration introduces different and widely unknown conditions governing the impacts and the fate of the pollutants......, and it is therefore difficult to assess the overall environmental impact. This paper gives a state of the art assessment of the water quality aspects of stormwater infiltration and proposes ways of managing the inherent problems. The major stormwater pollution sources are highlighted and the different processes...... operating in the soil and groundwater are described. The paper also discusses how the environmental risk of urban stormwater infiltration can be assessed, and outlines the possibilities for designing environmentally safe infiltration systems....

  12. Composite fibrous glaucoma drainage implant

    Science.gov (United States)

    Klapstova, A.; Horakova, J.; Shynkarenko, A.; Lukas, D.

    2017-10-01

    Glaucoma is a frequent reason of loss vision. It is usually caused by increased intraocular pressure leading to damage of optic nerve head. This work deals with the development of fibrous structure suitable for glaucoma drainage implants (GDI). Commercially produced metallic glaucoma implants are very effective in lowering intraocular pressure. However, these implants may cause adverse events such as damage to adjacent tissue, fibrosis, hypotony or many others [1]. The aim of this study is to reduce undesirable properties of currently produced drains and improve their properties by creating of the composite fibrous drain for achieve a normal intraocular pressure. Two types of electrospinning technologies were used for the production of very small tubular implants. First type was focused for production of outer part of tubular drain and the second type of electrospinning method made the inner part of shape follows the connections of both parts. Complete implant had a special properties suitable for drainage of fluid. Morphological parameters, liquid transport tests and in-vitro cell adhesion tests were detected.

  13. Urban drainage system planning and design--challenges with climate change and urbanization: a review.

    Science.gov (United States)

    Yazdanfar, Zeinab; Sharma, Ashok

    2015-01-01

    Urban drainage systems are in general failing in their functions mainly due to non-stationary climate and rapid urbanization. As these systems are becoming less efficient, issues such as sewer overflows and increase in urban flooding leading to surge in pollutant loads to receiving water bodies are becoming pervasive rapidly. A comprehensive investigation is required to understand these factors impacting the functioning of urban drainage, which vary spatially and temporally and are more complex when weaving together. It is necessary to establish a cost-effective, integrated planning and design framework for every local area by incorporating fit for purpose alternatives. Carefully selected adaptive measures are required for the provision of sustainable drainage systems to meet combined challenges of climate change and urbanization. This paper reviews challenges associated with urban drainage systems and explores limitations and potentials of different adaptation alternatives. It is hoped that the paper would provide drainage engineers, water planners, and decision makers with the state of the art information and technologies regarding adaptation options to increase drainage systems efficiency under changing climate and urbanization.

  14. Pollution Probe.

    Science.gov (United States)

    Chant, Donald A.

    This book is written as a statement of concern about pollution by members of Pollution Probe, a citizens' anti-pollution group in Canada. Its purpose is to create public awareness and pressure for the eventual solution to pollution problems. The need for effective government policies to control the population explosion, conserve natural resources,…

  15. BACTERIOPLANKTON DYNAMICS IN A SUBTROPICAL ESTUARY: EVIDENCE FOR SUBSTRATE LIMITATION

    Science.gov (United States)

    Bacterioplankton abundance and metabolic characteristics were measured along a transect in Pensacola Bay, Florida, USA, to examine the factors that control microbial water column processes in this subtropical estuary. The microbial measures included 3 H-L-leucine incorporation, e...

  16. 21 CFR 1250.65 - Drainage.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Drainage. 1250.65 Section 1250.65 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) REGULATIONS UNDER... Servicing Areas for Land and Air Conveyances § 1250.65 Drainage. All platforms and other places at which...

  17. Dynamic drainage of froth with wood fibers

    Science.gov (United States)

    J.Y. Zhu; Freya Tan

    2005-01-01

    Understanding froth drainage with fibers (or simply called fiber drainage in froth) is important for improving fiber yield in the flotation deinking operation. In this study, the data of water and fiber mass in foams collected at different froth heights were used to reconstruct the time dependent and spatially resolved froth density and fiber volumetric concentration...

  18. 24 CFR 3285.604 - Drainage system.

    Science.gov (United States)

    2010-04-01

    ... 24 Housing and Urban Development 5 2010-04-01 2010-04-01 false Drainage system. 3285.604 Section... DEVELOPMENT MODEL MANUFACTURED HOME INSTALLATION STANDARDS Ductwork and Plumbing and Fuel Supply Systems § 3285.604 Drainage system. (a) Crossovers. Multi-section homes with plumbing in more than one section...

  19. Anatomy of a subtropical intrathermocline eddy

    Science.gov (United States)

    Barceló-Llull, Bàrbara; Sangrà, Pablo; Pallàs-Sanz, Enric; Barton, Eric D.; Estrada-Allis, Sheila N.; Martínez-Marrero, Antonio; Aguiar-González, Borja; Grisolía, Diana; Gordo, Carmen; Rodríguez-Santana, Ángel; Marrero-Díaz, Ángeles; Arístegui, Javier

    2017-06-01

    An interdisciplinary survey of a subtropical intrathermocline eddy was conducted within the Canary Eddy Corridor in September 2014. The anatomy of the eddy is investigated using near submesoscale fine resolution two-dimensional data and coarser resolution three-dimensional data. The eddy was four months old, with a vertical extension of 500 m and 46 km radius. It may be viewed as a propagating negative anomaly of potential vorticity (PV), 95% below ambient PV. We observed two cores of low PV, one in the upper layers centered at 85 m, and another broader anomaly located between 175 m and the maximum sampled depth in the three-dimensional dataset (325 m). The upper core was where the maximum absolute values of normalized relative vorticity (or Rossby number), |Ro| =0.6, and azimuthal velocity, U=0.5 m s-1, were reached and was defined as the eddy dynamical core. The typical biconvex isopleth shape for intrathermocline eddies induces a decrease of static stability, which causes the low PV of the upper core. The deeper low PV core was related to the occurrence of a pycnostad layer of subtropical mode water that was embedded within the eddy. The eddy core, of 30 km radius, was in near solid body rotation with period of 4 days. It was encircled by a thin outer ring that was rotating more slowly. The kinetic energy (KE) content exceeded that of available potential energy (APE), KE/APE=1.58; this was associated with a low aspect ratio and a relatively intense rate of spin as indicated by the relatively high value of Ro. Inferred available heat and salt content anomalies were AHA=2.9×1018 J and ASA=14.3×1010 kg, respectively. The eddy AHA and ASA contents per unit volume largely exceed those corresponding to Pacific Ocean intrathermocline eddies. This suggests that intrathermocline eddies may play a significant role in the zonal conduit of heat and salt along the Canary Eddy Corridor.

  20. Percutaneous catheter drainage of tuberculous psoas abscesses

    International Nuclear Information System (INIS)

    Pombo, F.; Martin-Egana, R.; Cela, A.; Diaz, J.L.; Linares-Mondejar, P.; Freire, M.

    1993-01-01

    Six patients with 7 tuberculous psoas or ilio-psoas abscesses were treated by CT-guided catheter drainage and chemotherapy. The abscesses (5 unilateral and 1 bilateral) were completely drained using a posterior or lateral approach. The abscess volume was 70 to 700 ml (mean 300 ml) and the duration of drainage 5 to 11 days (mean 7 days). Immediate local symptomatic improvement was achieved in all patients, and there were no procedural complications. CT follow-up at 3 to 9 months showed normalization in 5 patients, 2 of whom are still in medical therapy. One patient, who did not take the medication regularly, had a recurrent abscess requiring new catheter drainage after which the fluid collection disappeared. Percutaneous drainage represents an efficient and attractive alternative to surgical drainage as a supplement to medical therapy in the management of patients with large tuberculous psoas abscesses. (orig.)

  1. Scale-dependent environmental control of mesozooplankton community structure in three aquaculture subtropical bays of China

    Directory of Open Access Journals (Sweden)

    Dong Sun

    2016-04-01

    Full Text Available Most subtropical bays of China have been under heavy pollution since the late 1990s, mainly because of the rapid development of aquaculture and discharge of industrial and agricultural wastewater. Some projects were conducted to investigate the zooplankton community in these bays, but those studies were less focused on the relationship between spatial structure of mesozooplankton community and environmental variables in/among bays. The mesozooplankton community structures in relation to physical, chemical and biological variables were studied in three subtropical bays of China with seasons and different spatial scales during 2000 and 2002–2003. Data were collected on temperature (T, salinity (S, concentration of chlorophyll a (Chl a, pH, dissolved oxygen (DO, soluble reactive phosphate (SRP, dissolved inorganic nitrogen (DIN, chemical oxygen demand (COD, suspended particle material (SPM and mesozooplankton taxonomic abundances. Correlation analysis showed that the main environmental factors correlated to the total abundance of mesozooplankton in these subtropical bays were Chl a, temperature, COD and SRP. Multivariate analysis indicated that DO, Chl a and temperature were the principal factors in influencing spatial differentiation of zooplankton community structure in the inter-bay scale. At the within-bay scale, the influencing factors were different among bays; the main factors were physical variables for Xiangshan Bay and Sanmen Bay, while chemical variables for Yueqing Bay, respectively. The results revealed that the environmental variables that affected spatial structure of mesozooplankton community were different at inter-bay scale and within-bay scales, and zooplankton community was more influenced by chemical (e.g. nutrients/ammonia variables when under serious eutrophication condition, while it would be more influenced by physical variables (temperature/salinity when under less eutrophic conditions.

  2. Decadal changes in salinity in the oceanic subtropical gyres

    Science.gov (United States)

    Melzer, Bryce A.; Subrahmanyam, Bulusu

    2017-01-01

    We analyzed spatial and temporal salinity trends in five subtropical gyre regions over the past six decades using Simple Ocean Data Assimilation (SODA) reanalysis with a focus on the subsurface salinity of the upper 1000 m of the ocean. Our results indicate an overall salinity increase within the mixed layer, and a salinity decrease at depths greater than 200 m in the global subtropical gyres over 61 years, of which each individual gyre was analyzed in further detail. We determine that freshwater fluxes at the air-sea interface are the primary drivers of the sea surface salinity (SSS) signature over these open ocean regions by quantifying the advective contribution within the surface layer. This was demonstrated through a mixed layer salinity budget in each subtropical gyre based on the vertically integrated advection and entrainment of salt. Our analysis of decadal variability of fluxes into and out of the gyres reveals little change in the strength of the mean currents through this region despite an increase in the annual export of salt in all subtropical gyres, with the meridional component dominating the zonal. This study reveals that the salt content of E-P maximum waters advected into the subtropical gyres is increasing over time. A combination of increasing direct evaporation over the regions with increasing remote evaporation over nearby E-P maxima is believed to be the main driver in increasing salinity of the subtropical oceans, suggesting an intensification of the global water cycle over decadal time scales.

  3. Subtropical Dust Storms and Downslope Wind Events

    Science.gov (United States)

    Pokharel, Ashok Kumar; Kaplan, Michael L.; Fiedler, Stephanie

    2017-10-01

    We performed detailed mesoscale observational analyses and Weather Research and Forecasting (WRF) model simulations to study the terrain-induced downslope winds that generated dust-emitting winds at the beginning of three strong subtropical dust storms in three distinctly different regions of North Africa and the Arabian Peninsula. We revisit the Harmattan dust storm of 2 March 2004, the Saudi dust storm of 9 March 2009, and the Bodélé Depression dust storm of 8 December 2011 and use high-resolution WRF modeling to assess the dynamical processes during the onset of the storms in more depth. Our results highlight the generation of terrain-induced downslope winds in response to the transition of the atmospheric flow from a subcritical to supercritical state in all three cases. These events precede the unbalanced adjustment processes in the lee of the mountain ranges that produced larger-scale dust aerosol mobilization and transport. We see that only the higher-resolution data sets can resolve the mesoscale processes, which are mainly responsible for creating strong low-level terrain-induced downslope winds leading to the initial dust storms.

  4. Endoscopic ultrasound-guided drainage of pancreatic pseudocysts

    DEFF Research Database (Denmark)

    Saftoiu, Adrian; Vilmann, Andreas; Vilmann, Peter

    2015-01-01

    Pancreatic pseudocysts are fluid collections in the peripancreatic tissues associated with acute or chronic pancreatitis. Endoscopic ultrasound (EUS)-guided drainage has become an established indication, having better results as compared to percutaneous drainage, nonguided endoscopic drainage...

  5. Acid mine drainage as an important mechanism of natural radiation enhancement in mining areas

    International Nuclear Information System (INIS)

    Fernandes, H.M.; Franklin, M.R.

    2002-01-01

    Acid mine drainage (AMD) is a world wide problem that occurs whenever sulfidic material is present in association to the mined ore. The acidic waters generated by the process of sulfide minerals oxidation can mobilize important amounts of pollutants and cause significant environmental impacts. The composition of the drainage will depend, on a very large extent, on the mineralogy of the rocks. The purpose of this paper is to demonstrate that acid mine drainage has the potential to enhance the natural levels of environmental radioactivity. The paper revises some strategies to be used in the diagnostic of the problem. General mathematical formulations that can assist on the prediction of the duration of the problem, and the definition of the size of the oxidizing zones in a waste dump are given. A study case on a waste dump of the Pocos de Caldas Uranium Mining Site, Brazil is also presented. (author)

  6. The Metal And Sulphate Removal From Mine Drainage Waters By Biological-Chemical Ways

    Directory of Open Access Journals (Sweden)

    Jenčárová Jana

    2015-06-01

    Full Text Available Mine drainage waters are often characterized by high concentrations of sulphates and metals as a consequence of the mining industry of sulphide minerals. The aims of this work are to prove some biological-chemical processes utilization for the mine drainage water treatment. The studied principles of contamination elimination from these waters include sulphate reduction and metal bioprecipitation by the application of sulphate-reducing bacteria (SRB. Other studied process was metal sorption by prepared biogenic sorbent. Mine drainage waters from Slovak localities Banská Štiavnica and Smolník were used to the pollution removal examination. In Banská Štiavnica water, sulphates decreased below the legislative limit. The elimination of zinc by sorption experiments achieved 84 % and 65 %, respectively.

  7. Acute pollution of recipients in urban areas

    DEFF Research Database (Denmark)

    Rauch, W.; Harremoës, P.

    1997-01-01

    Oxygen and ammonia concentration are key parameters of acute water pollution in urban rivers. These two abiotic parameters are statistically assessed for a historical rain series by means of a simplified deterministic model of the integrated drainage system. Continuous simulation of the system...... performance indicates that acute water pollution is caused by intermittent discharges from both sewer system and wastewater treatment plant. Neglecting one of them in the evaluation of the environmental impact gives a wrong impression of total system behavior. Detention basins and alternative operational...... modes in the treatment plant under wet weather loading have a limited positive effect for minimizing acute water pollution. (C) 1997 IAWQ. Published by Elsevier Science Ltd....

  8. Air Pollution

    Science.gov (United States)

    ... Health Lead Mercury Mold Nanomaterials Ozone Perfluorinated Chemicals Pesticides Radon Soy Infant Formula Styrene Water Pollution Weather ... government and non-government websites covering specific environmental, biological, and chemical agents that cause indoor air pollution. ...

  9. Water pollution

    OpenAIRE

    Institute, Marine

    2013-01-01

    Students will learn about what causes water pollution and how to be environmentally aware. *Note: Students should understand the concept of the water cycle before moving onto water pollution (see Lesson Plan “Oceans all Around Us”).

  10. Noise Pollution

    Science.gov (United States)

    ... Us Share Clean Air Act Title IV - Noise Pollution The 1990 Clean Air Act Amendments added a ... abatement 7642 Authorization of appropriations What is Noise Pollution? The traditional definition of noise is “unwanted or ...

  11. US and RTG guided percutaneous biliary drainage

    International Nuclear Information System (INIS)

    Bukowski, J.

    1994-01-01

    Under combined US and fluoroscopic guidance from anterior approach through left liver lobe a Seldinger technique was used for biliary drainage in 46 patients with nonresectable malignant biliary obstruction. In 9 cases of hilar tumor separating both hepatic ducts a second catheter was inserted through right liver lobe. In 11 cases an internal-external drainage was established. In 3 cases the externally drained bile was recycled by connecting the transhepatic catheter to a percutaneous gastrostomy also performed under US guidance. No severe complications were observed. A described drainage technique provides an effective palliative intervention for advanced biliary malignancies. (author)

  12. Cholangitis following percutaneous biliary drainage

    International Nuclear Information System (INIS)

    Audisio, R.A.; Bozzetti, F.; Cozzi, G.; Severini, A.; Belloni, M.; Friggerio, L.F.

    1989-01-01

    The binomial PTBD-cholangitis often stands under different and sometimes even opposite relations. Among its indications the procedure lists, the treatment of cholangitis which, on the other hand, may be itself a complication of biliary drainage. The present work proposes a critical review of cholangitis-PTBD correlations, from an ordinary clinical-radiological point of view. Different pathogenetic hypothesis of cholangitis (inflammation, cholestasis, surgical manipulation) are discussed together with risk factors (impaired macrophagic-phagocytic system, immunosuppresion, wide neoplastic liver involvement, multiple intrahepatic ductal obstructions, chronic liver diseases, aged patients, etc.). The authors also report about prevention and treatment of septic complications which must be carried out following technical and therapeutic strategies, such as chemoprophylaxis and focused antibiotic therapy according to coltural samples, slow injection of small amounts of contrast medium, peripheral branches approach, gentle handling of catheters and guidewires, flushing with saline solutions and brushing of the catheter itself, and finally use of large gauge catheters in the presence of bile sludge

  13. Air Pollution.

    Science.gov (United States)

    Barker, K.; And Others

    Pollution of the general environment, which exposes an entire population group for an indeterminate period of time, certainly constitutes a problem in public health. Serious aid pollution episodes have resulted in increased mortality and a possible relationship between chronic exposure to a polluted atmosphere and certain diseases has been…

  14. Water Pollution

    International Nuclear Information System (INIS)

    Goni, J.

    1984-01-01

    This work is about the water pollution. The air and the water interaction cycles is the main idea of the geochemical pollution conception. In the water surface as well as in the deep aquifers we can found cough metals or minerals from the athmosferic air. The activities of mercury fluor and nitrates are important to the pollution study

  15. Influence of alternative and conventional farming practices on subsurface drainage and water quality.

    Science.gov (United States)

    Oquist, K A; Strock, J S; Mulla, D J

    2007-01-01

    Agricultural runoff contributes nutrients to nonpoint-source pollution of surface waters. This study was conducted to investigate the potential use of alternative farming practices to improve water quality. The study examined the effects of both alternative and conventional farming practices on subsurface drainage and nitrogen and phosphorus loss through subsurface drainage from glacial till soils (i.e., Calciaquolls, Endoaquolls, Eutrudepts, Hapludolls) in southwest Minnesota. Alternative farming practices included organic management practices, species biodiversity, and/or practices that include reduced inputs of synthetic fertilizer and pesticides. Conventional farming practices include corn-soybean (Zea mays L.-Glycine max L., respectively) rotations and their associated recommended fertilizer rates as well as pesticide usage. Precipitation was highly variable during the 3-yr study period including a below-average year (2003), an average year (2002), and an above-average year (2004). Results indicate that alternative farming practices reduced subsurface drainage discharge by 41% compared with conventional practices. Flow-weighted mean nitrate-nitrogen (nitrate N) concentrations during tile flow were 8.2 and 17.2 mg L(-1) under alternative and conventional farming practices, respectively. Alternative farming practices reduced nitrate N losses by between 59 and 62% in 2002 and 2004 compared with conventional practices. Ammonium-nitrogen (ammonium N), orthophosphorus, and total phosphorus losses in subsurface drainage were very low and did not pose a substantial risk of pollution. Results suggest that alternative farming practices have the potential to reduce agricultural impacts on water quality.

  16. A review of acid drainage from waste rock dumps and mine sites (Australian and Scandinavia)

    International Nuclear Information System (INIS)

    Harries, J.R.

    1990-05-01

    This report reviews the literature from Australia and Scandinavia on acid drainage from pyritic waste rock dumps with an emphasis on measurements and theory of processes that control the rage of oxidation and the release of pollutants. Conditions within waste rock dumps have been measured at several mine sites and a range of rehabilitation treatments have been tried to reduce the release of pollutants. A number of models have been proposed to calculate air flow, water transport and geochemistry. The data and experience at the mine sites are compared with predictions of the models. Details of Australian and Swedish mine sites where waste rock is a source of acid drainage are described in the Appendices. 92 refs., 2 tabs., 10 figs

  17. Detecting Subsurface Agricultural Tile Drainage using GIS and Remote Sensing Technique

    Science.gov (United States)

    Budhathoki, M.; Gokkaya, K.; Tank, J. L.; Christopher, S. F.; Hanrahan, B.

    2015-12-01

    Subsurface tile drainage is a common practice in many of the row crop dominated agricultural lands in the Upper Midwest, which increases yield by making the soil more productive. It is reported that nearly half of all cropland in Indiana benefits from some sort of artificial drainage. However, subsurface tile has a significant negative impact on surface water quality by providing a fast means of transport for nutrients from fertilizers. Therefore, generating spatial data of tile drainage in the field is important and useful for agricultural landscape and hydrological studies. Subsurface tile drains in Indiana's croplands are not widely mapped. In this study, we will delineate subsurface tile drainage in agricultural land in Shatto Ditch watershed, located in Kosciusko County, Indiana. We will use geo-spatial methodology, which was purposed by earlier researchers to detect tile drainage. We will use aerial color-infrared and satellite imagery along with Light Detection and Ranging (LiDAR) data. In order to map tile lines with possible accuracy, we will use GIS-based analysis in combination with remotely sensed data. This research will be comprised of three stages: 1) masking out the potential drainage area using a decision tree rule based on land cover information, soil drainage category, surface slope, and satellite image differencing technique, 2) delineate tile lines using image processing techniques, and 3) check the accuracy of mapped tile lines with ground control points. To our knowledge, this study will be the first to check the accuracy of mapping with ground truth data. Based on the accuracy of results, we will extend the methodology to greater spatial scales. The results are expected to contribute to better characterizing and controlling water pollution sources in Indiana, which is a major environmental problem.

  18. A multimedia fugacity river model of pentachlorophenol in South Drainage Canal, China.

    Science.gov (United States)

    Chi, Jie; Huang, Guo-Lan

    2002-01-01

    An investigation of Pentachlorophenol (PCP) in South Drainage Canal and Haihe Estuary, Tianjin, China was carried out from 1998 to 1999. PCP was found in each sample of the surface microlayer, subsurface water, sediment and air. The waste drainage from a PCP-producing plant was the main pollution source of PCP to Haihe Estuary. The enrichment phenomenon of PCP in the surface microlayer was reported for the first time. The maximum enrichment factor was 4.11. A multimedia (including air, the surface microlayer, water and sediment) fugacity river model was established and successfully applied to fate data for pentachlorophenol in South Drainage Canal. The results showed that under steady state, 97.09% of the loaded PCP was removed by advective outflow into Bohai Bay and 2.46% was by the biodegradation in the water phase. The residue of PCP in South Drainage Canal mainly distributed (99.56%) in the water phase. The discharge rate of PCP from South Drainage Canal to Bohai Bay was 53.4 kg/h.

  19. Oil pollution

    International Nuclear Information System (INIS)

    Mankabady, Samir.

    1994-08-01

    Oil enters the marine environment when it is discharged, or has escaped, during transport, drilling, shipping, accidents, dumping and offshore operations. This book serves as a reference both on the various complex international operational and legal matters of oil pollution using examples such as the Exxon Valdez, the Braer and Lord Donaldson's report. The chapters include the development of international rules on the marine environment, the prevention of marine pollution from shipping activities, liability for oil pollution damage, the conflict of the 1990 Oil Pollution Act and the 1992 protocols and finally the cooperation and response to pollution incidents. (UK)

  20. Pollution Assessment of Rice Agriculture in the Taihu Lake Watershed Based on the Pollution Footprint: A Case Study of Changzhou City and Yixing City, China

    OpenAIRE

    LI Jing; MIN Qing-wen; LI Wen-hua; JIAO Wen-jun; YUAN Zheng

    2014-01-01

    Rice agriculture has been proved to make a great contribution to the food quantity security, but farmers are driven by economic in-terests to overuse the pesticides and chemical fertilizers. The water environment is getting worse and worse. Based on the first national census of pollution data and the production and drainage coefficient of the pollutants, this paper calculated pollutant (COD, TN and TP)quantity in-lets into river from rice agriculture. The pollution footprint based on the poll...

  1. Pressure Jumps during Drainage in Macroporous Soils

    DEFF Research Database (Denmark)

    Soto, Diego; Paradelo Pérez, Marcos; Corral, A

    2018-01-01

    Tensiometer readings obtained at high resolution during drainage of structured soil columns revealed pressure jumps with long range correlations and burst sequences with a hierarchical structure. The statistical properties of jumps are similar to Haines jumps described in invasion percolation...

  2. Evaluating roadway subsurface drainage practices - phase II.

    Science.gov (United States)

    2015-04-01

    Well-performing subsurface drainage systems form an important aspect of pavement design by the Iowa Department of : Transportation (DOT). The recently completed Iowa Highway Research Board (IHRB) project TR-643 provided extensive : insights into Iowa...

  3. Drainage information analysis and mapping system.

    Science.gov (United States)

    2012-10-01

    The primary objective of this research is to develop a Drainage Information Analysis and Mapping System (DIAMS), with online inspection : data submission, which will comply with the necessary requirements, mandated by both the Governmental Accounting...

  4. VT Lakes and Ponds Drainage Basins

    Data.gov (United States)

    Vermont Center for Geographic Information — (Link to Metadata) The WaterHydro_LKBSPRE layer consists of drainage basins for water bodies of approximately five or more acres. The data was digitized from...

  5. Fractal Analysis of Drainage Basins on Mars

    Science.gov (United States)

    Stepinski, T. F.; Marinova, M. M.; McGovern, P. J.; Clifford, S. M.

    2002-01-01

    We used statistical properties of drainage networks on Mars as a measure of martian landscape morphology and an indicator of landscape evolution processes. We utilize the Mars Orbiter Laser Altimeter (MOLA) data to construct digital elevation maps (DEMs) of several, mostly ancient, martian terrains. Drainage basins and channel networks are computationally extracted from DEMs and their structures are analyzed and compared to drainage networks extracted from terrestrial and lunar DEMs. We show that martian networks are self-affine statistical fractals with planar properties similar to terrestrial networks, but vertical properties similar to lunar networks. The uniformity of martian drainage density is between those for terrestrial and lunar landscapes. Our results are consistent with the roughening of ancient martian terrains by combination of rainfall-fed erosion and impacts, although roughening by other fluvial processes cannot be excluded. The notion of sustained rainfall in recent Mars history is inconsistent with our findings.

  6. Pyrolusite Process® to remove acid mine drainage contaminants from Kimble Creek in Ohio: A pilot study

    Science.gov (United States)

    Shiv Hiremath; Kirsten Lehtoma; Mike Nicklow; Gary. Willison

    2013-01-01

    The Kimble Creek abandoned coal mine site, located on Wayne National Forest in southeastern Ohio, is among several abandoned coal mine sites that have been responsible for the acid mine drainage (AMD) polluting ground and surface water. Materials released by AMD include iron, aluminum, manganese, other hazardous substances, and acidity that are harmful to aquatic life...

  7. Performance evaluation and accuracy of passive capillary samplers (PCAPs) for estimating real-time drainage water fluxes

    Science.gov (United States)

    Successful monitoring of pollutant transport through the soil profile requires accurate, reliable, and appropriate instrumentation to measure amount of drainage water or flux within the vadose layer. We evaluated the performance and accuracy of automated passive capillary wick samplers (PCAPs) for ...

  8. Social impact assessment of subsurface drainage

    International Nuclear Information System (INIS)

    Azhar, A.H.; Rafiq, M.; Alam, M.M.

    2005-01-01

    Social impact assessment of four drainage projects namely; Mardan SCARP Project (MSP), Fourth Drainage Project, Faisalabad (FDP), Chashma Command Area Development Project (CCADP) and Mirpurkhas Tile Drainage Project (MKOP) has been done. For this purpose, a socio-technical survey was carried out in which randomly selected farmers were interviewed. The investigations revealed that although significant population (-77%) at four study sites was educated, yet, the farmers were not satisfactorily educated to understand the operation and maintenance of drainage systems. The perusal of data revealed that 14%, 17% and 25% respondents from MSP, FOP and MKDP respectively had to migrate from their villages mainly due to pre-project water logging problem. However, installation of drainage systems in those areas improved the situation resulting in the increase of farm income, which was an attraction for them to return to their villages. The analysis of farm mechanization revealed that at MSP, FDP, CCADP and MKOP sites 71%, 42%, 40% and 75% respondents respectively were tractor owners and owners of some kind of other farm implements, whereas, remaining respondents were performing their farm operations on hire basis. Although, hire operation basis is much better than traditional ways, however, improving the farm mechanization could further enhance the benefits of drainage systems. The investigations revealed that a significant majority of respondents at four project sites had never met the Agricultural Extension Officer. The farmers' access to financing institutions such as ZTB was also negligible. There was lack of coordination among various departments such as WAPDA, Agriculture Extension and Irrigation and Power Department at four study sites. Nevertheless, the overall social impact investigations did reveal that the objectives of drainage systems installation have been achieved in terms of uplifting the socio-economic conditions of drainage areas. To make the efficient use of

  9. Sustainable Drainage Practices in Spain, Specially Focused on Pervious Pavements

    Directory of Open Access Journals (Sweden)

    Jorge Rodriguez-Hernandez

    2013-01-01

    Full Text Available The Spanish climate is full of contrasts, with torrential rains and long droughts; under these conditions, appropriate water management is essential. In Spain, until the end of the twentieth century, water management and legislative development lagged behind other more developed countries. Nowadays, great efforts are being made to reverse this situation and improve both water management and legislation in order to control the two main problems related to stormwater management in cities: floods and diffuse pollution. In this context, Sustainable Urban Drainage Systems (SUDS were developed as the main solution to these problems. The study of these techniques started in the 1970s in the USA, but they were not studied in Spain until 1993 when the University of Cantabria and CLABSA started to look into solutions for stormwater management. After 20 years of research and application, sustainable drainage in Spain is still behind other countries in spite of the efforts to change this situation, notably by the University of Cantabria with 10 years of experience in these techniques, mainly regarding pervious pavements, where more than 13 related research projects have been carried out. The future challenges focus on the application of pervious pavements for Urban Hydrological Rehabilitation.

  10. Gaseous elemental mercury (GEM) fluxes over canopy of two typical subtropical forests in south China

    Science.gov (United States)

    Yu, Qian; Luo, Yao; Wang, Shuxiao; Wang, Zhiqi; Hao, Jiming; Duan, Lei

    2018-01-01

    Mercury (Hg) exchange between forests and the atmosphere plays an important role in global Hg cycling. The present estimate of global emission of Hg from natural source has large uncertainty, partly due to the lack of chronical and valid field data, particularly for terrestrial surfaces in China, the most important contributor to global atmospheric Hg. In this study, the micrometeorological method (MM) was used to continuously observe gaseous elemental mercury (GEM) fluxes over forest canopy at a mildly polluted site (Qianyanzhou, QYZ) and a moderately polluted site (Huitong, HT, near a large Hg mine) in subtropical south China for a full year from January to December in 2014. The GEM flux measurements over forest canopy in QYZ and HT showed net emission with annual average values of 6.67 and 0.30 ng m-2 h-1, respectively. Daily variations of GEM fluxes showed an increasing emission with the increasing air temperature and solar radiation in the daytime to a peak at 13:00, and decreasing emission thereafter, even as a GEM sink or balance at night. High temperature and low air Hg concentration resulted in the high Hg emission in summer. Low temperature in winter and Hg absorption by plant in spring resulted in low Hg emission, or even adsorption in the two seasons. GEM fluxes were positively correlated with air temperature, soil temperature, wind speed, and solar radiation, while it is negatively correlated with air humidity and atmospheric GEM concentration. The lower emission fluxes of GEM at the moderately polluted site (HT) when compared with that in the mildly polluted site (QYZ) may result from a much higher adsorption fluxes at night in spite of a similar or higher emission fluxes during daytime. This shows that the higher atmospheric GEM concentration at HT restricted the forest GEM emission. Great attention should be paid to forests as a crucial increasing Hg emission source with the decreasing atmospheric GEM concentration in polluted areas because of Hg

  11. Percutaneous drainage of pelvic fluid collection

    International Nuclear Information System (INIS)

    Lee, Eun Young; Sohn, Cheol Ho

    1995-01-01

    To evaluate safe access route and success rate of percutaneous drainage of pelvic fluid collection. The 35 percutaneous drainages of pelvic fluid collection under the CT and fluorosocpic guidance were done in 32 patients. The anterior transabdominal approach was done in 20 patients, while the nine patients used the transgluteal approach through greater sciatic foramen. Three patients, who had septated or noncommunicating abscesses, underwent drainage using both approaches. The catheter was removed when the patient's symptom and laboratory data were improved or the amount of drainage and the size of fluid collection were markedly reduced. Success, partial success and failure were classified. The causes of fluid collection were complication of intraabdominal operation in 27 patient. The diagnosis after drainage included abscess (21), loculated ascites (6), and hematoma (4). The 27 cases (30 procedure) were treated successfully and the mean duration of catheter insertion was 10 days. The partial successes were two cases (2 procedures), which had palliative purpose. Three cases (3 procedures) were failed, which were multiple loculated ascites of pancreatic origin (2) and recurrent abscess (1). The significant complication during the procedure or drainage was not noted

  12. 14 CFR 27.1187 - Ventilation and drainage.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Ventilation and drainage. 27.1187 Section... and drainage. Each compartment containing any part of the powerplant installation must have provision for ventilation and drainage of flammable fluids. The drainage means must be— (a) Effective under...

  13. Late Pleistocene glacial fluctuations in Cordillera Oriental, subtropical Andes

    Science.gov (United States)

    Martini, Mateo A.; Kaplan, Michael R.; Strelin, Jorge A.; Astini, Ricardo A.; Schaefer, Joerg M.; Caffee, Marc W.; Schwartz, Roseanne

    2017-09-01

    The behavior of subtropical glaciers during Middle to Late Pleistocene global glacial maxima and abrupt climate change events, specifically in Earth's most arid low-latitude regions, remains an outstanding problem in paleoclimatology. The present-day climate of Cordillera Oriental, in arid northwestern Argentina, is influenced by shifts in subtropical climate systems, including the South American Summer Monsoon. To understand better past glacier-subtropical climates during the global Last Glacial Maximum (LGM, 26.5-19 ka) and other time periods, we combined geomorphic features with forty-two precise 10Be ages on moraine boulders and reconstructed paleo-equilibrium line altitudes (ELA) at Nevado de Chañi (24°S) in the arid subtropical Andes. We found a major glacial expansion at ∼23 ± 1.6 ka, that is, during the global LGM. Additional glacial expansions are observed before the global LGM (at ∼52-39 ka), and after, at 15 ± 0.5 and 12 ± 0.6 ka. The ∼15 ka glacial event was found on both sides of Chañi and the ∼12 ka event is only recorded on the east side. Reconstructed ELAs of the former glaciers exhibit a rise from east to west that resembles the present subtropical climate trajectory from the Atlantic side of the continent; hence, we infer that this climate pattern must have been present in the past. Based on comparison with other low-latitude paleoclimate records, such as those from lakes and caves, we infer that both temperature and precipitation influenced past glacial occurrence in this sector of the arid Andes. Our findings also imply that abrupt deglacial climate events associated with the North Atlantic, specifically curtailed meridional overturning circulation and regional cooling, may have had attendant impacts on low subtropical Southern Hemisphere latitudes, including the climate systems that affect glacial activity around Nevado de Chañi.

  14. Subsurface flow in a soil-mantled subtropical dolomite karst slope: A field rainfall simulation study

    Science.gov (United States)

    Fu, Z. Y.; Chen, H. S.; Zhang, W.; Xu, Q. X.; Wang, S.; Wang, K. L.

    2015-12-01

    Soil and epikarst co-evolve resulting in complex structures, but their coupled structural effects on hydrological processes are poorly understood in karst regions. This study examined the plot-scale subsurface flow characteristics from an integrated soil-epikarst system perspective in a humid subtropical cockpit karst region of Southwest China. A trench was excavated to the epikarst lower boundary for collecting individual subsurface flows in five sections with different soil thicknesses. Four field rainfall simulation experiments were carried out under different initial moisture conditions (dry and wet) and rainfall intensities (114 mm h- 1 (high) and 46 mm h- 1 (low) on average). The soil-epikarst system was characterized by shallow soil overlaying a highly irregular epikarst surface with a near-steady infiltration rate of about 35 mm h- 1. The subsurface flows occurred mainly along the soil-epikarst interface and were dominated by preferential flow. The subsurface flow hydrographs showed strong spatial variability and had high steady-state coefficients (0.52 and 0.36 for high and low rainfall intensity events). Irregular epikarst surface combining with high vertical drainage capacity resulted in high threshold rainfall depths for subsurface flows: 67 mm and 263 mm for initial wet and dry conditions, respectively. The above results evidenced that the irregular and permeable soil-epikarst interface was a crucial component of soil-epikarst architecture and consequently should be taken into account in the hydrological modeling for karst regions.

  15. Impact of Geography and Climate on the Genetic Differentiation of the Subtropical Pine Pinus yunnanensis.

    Science.gov (United States)

    Wang, Baosheng; Mao, Jian-Feng; Zhao, Wei; Wang, Xiao-Ru

    2013-01-01

    Southwest China is a biodiversity hotspot characterized by complex topography, heterogeneous regional climates and rich flora. The processes and driving factors underlying this hotspot remain to be explicitly tested across taxa to gain a general understanding of the evolution of biodiversity and speciation in the region. In this study, we examined the role played by historically neutral processes, geography and environment in producing the current genetic diversity of the subtropical pine Pinus yunnanensis. We used genetic and ecological methods to investigate the patterns of genetic differentiation and ecological niche divergence across the distribution range of this species. We found both continuous genetic differentiation over the majority of its range, and discrete isolated local clusters. The discrete differentiation between two genetic groups in the west and east peripheries is consistent with niche divergence and geographical isolation of these groups. In the central area of the species' range, population structure was shaped mainly by neutral processes and geography rather than by ecological selection. These results show that geographical and environmental factors together created stronger and more discrete genetic differentiation than isolation by distance alone, and illustrate the importance of ecological factors in forming or maintaining genetic divergence across a complex landscape. Our findings differ from other phylogenetic studies that identified the historical drainage system in the region as the primary factor shaping population structure, and highlight the heterogeneous contributions that geography and environment have made to genetic diversity among taxa in southwest China.

  16. Failures and complications of thoracic drainage

    Directory of Open Access Journals (Sweden)

    Đorđević Ivana

    2006-01-01

    Full Text Available Background/Aim. Thoracic drainage is a surgical procedure for introducing a drain into the pleural space to drain its contents. Using this method, the pleura is discharged and set to the physiological state which enables the reexpansion of the lungs. The aim of the study was to prove that the use of modern principles and protocols of thoracic drainage significantly reduces the occurrence of failures and complications, rendering the treatment more efficient. Methods. The study included 967 patients treated by thoracic drainage within the period from January 1, 1989 to June 1, 2000. The studied patients were divided into 2 groups: group A of 463 patients treated in the period from January 1, 1989 to December 31, 1994 in whom 386 pleural drainage (83.36% were performed, and group B of 602 patients treated form January 1, 1995 to June 1, 2000 in whom 581 pleural drainage (96.51% were performed. The patients of the group A were drained using the classical standards of thoracic drainage by the general surgeons. The patients of the group B, however, were drained using the modern standards of thoracic drainage by the thoracic surgeons, and the general surgeons trained for this kind of the surgery. Results. The study showed that better results were achieved in the treatment of the patients from the group B. The total incidence of the failures and complications of thoracic drainage decreased from 36.52% (group A to 12.73% (group B. The mean length of hospitalization of the patients without complications in the group A was 19.5 days versus 10 days in the group B. The mean length of the treatment of the patients with failures and complications of the drainage in the group A was 33.5 days versus 17.5 days in the group B. Conclusion. The shorter length of hospitalization and the lower morbidity of the studied patients were considered to be the result of the correct treatment using modern principles of thoracic drainage, a suitable surgical technique, and a

  17. The Ocean deserts:salt budgets of northern subtropical oceans and their

    KAUST Repository

    Carton, Jim

    2011-04-09

    The Ocean deserts: salt budgets of northern subtropical oceans and their relationship to climate variability The high salinity near surface pools of the subtropical oceans are the oceanic deserts, with high levels of evaporation and low levels of precip

  18. Air Pollution

    OpenAIRE

    Ababsa, Myriam

    2014-01-01

    The human costs of air pollution are considerable in Jordan. According to a report published in 2000 by the World Bank under the Mediterranean Environmental Technical Assistance Program (METAP), approximately 600 people die prematurely each year in Jordan because of urban pollution. 50-90% of air pollution in Jordanian towns is caused by road traffic. Readings taken in 2007 by Jordanian researchers showed that levels of black carbon particles in the air were higher in urban areas (caused by v...

  19. Information Pollution

    OpenAIRE

    Noruzi, Alireza

    2000-01-01

    The exponential growth of information resources creates new challenges for end-users. The correct information may be polluted by misinformation, disinformation, propaganda or incorrect information via the Internet and other media. This paper defines 'information pollution' as "the contamination of information by misinformation, disinformation, propaganda and incorrect information." The purpose of this paper is to present the methods of information pollution. It is concluded that it is sometim...

  20. Enviormental Pollution

    OpenAIRE

    Kanika Saini; Dr. Sona Malhotra

    2016-01-01

    Environment Pollution is one of the greatest problems today which is increasing with every passing year and causing crucial and severe damage to the earth. It has become a real problem since the beginning of the industrial revolution. It is the contamination of physical and biological components of the Earth / atmosphere system to such an extent that normal environmental processes are harmed. Pollution of the environment consists of five main types of pollution, namely air, water,...

  1. Environmental pollution

    International Nuclear Information System (INIS)

    Odzuck, W.

    1982-01-01

    The volume of the anthropogenic pollution of the environment (incl. radioactivity) is of great economical importance and has also a meaning to the health and happiness of people. The pocket book introduces into the whole problem by giving exact information and data. After a general survey, the pollutions of urban-industrial, and aquatic ecosystems are dealt with. The book closes with indications as to general principles, specific dangers, and the fature development of the environmental pollution. (orig.) [de

  2. Hydro-climatic dominated on long-term input-output nutrient budget of subtropical forest ecosystem

    Science.gov (United States)

    Chang, C. T.; Wang, C. P.; Huang, J. C.; Lin, T. C.

    2016-12-01

    Two-decadal budget of atmospheric deposition (input) and streamwater export (output) from 1994 to 2013 were collected in a subtropical forest at northeastern Taiwan. There were significant decline trends of summer SO42- and NO3- fluxes (June-August), but not for the winter. With the identifications of possible sources of air pollutants from atmospheric backward trajectories model and local air quality observations, the declining of sulfate and nitrate in the summer was possibly due to decreases of local emissions of SO2 and NOx. In contrast, the non-declining long-range transport of acid species might contribute a large portion of the acid deposition in the winter and led to the lack of significant declining trends of SO42- and NO3- fluxes. The results suggest that long-range transport of acidic pollutants could be a threat to forest ecosystems in the region. The two-decadal budget also revealed that both input and output of ions were positively correlated with water quantity, indicating strong hydro-climatic dominated the input-output nutrient cycling. Especially for the greater ions export via stream water during the wet summer growing season, which is noticeably contrast to the paradigm of biological control resulting in low ions export during the growing season. Our study is of significant implication under the trends of warming climate because global climate change could directly affect biogeochemical cycles particularly in the tropical/subtropical ecosystems through amplifying the seasonal precipitation.

  3. Source seasonality of polycyclic aromatic hydrocarbons (PAHs) in a subtropical city, Guangzhou, South China.

    Science.gov (United States)

    Li, J; Zhang, G; Li, X D; Qi, S H; Liu, G Q; Peng, X Z

    2006-02-15

    Mega-cities are large sources of air pollution on a regional base. Differences in energy structures, geographical settings and regional climate features lead to a large variety of air pollution sources from place to place. To understand the seasonality of air pollution sources is critical to precise emission inventories and a sound protection of human health. Based on a year-round dataset, the sources of PAHs in the air of Guangzhou were drawn by principal factor analysis (PCA) in combination with diagnostic ratios, and the seasonality of these sources were analyzed by PCA/MLR (multiple linear regressions) and discussed. The average total gaseous and particulate PAHs concentrations were 313 and 23.7 ng m(-3), respectively, with a higher concentration of vapor PAHs in summer and particulate PAHs in winter. In addition to vehicle exhaust, which contributed 69% of the particulate PAHs, coal combustion was still an important source and contributed 31% of the particulate PAHs. Relatively constant contribution from coal combustion was found through the year, implying that coal combustion in power plants was not a seasonally dependent source. Evaporation from contaminated ground may be an important source of light PAHs in summer, providing an average contribution of 68% to the total PAHs in this study. By comparing the PAH concentrations and meteorological parameters, we found that higher concentrations of particulate PAHs in winter resulted from enhanced vehicle exhaust under low temperature and accumulation of pollutants under decreased boundary layer, slower wind speed, and long-term dryness conditions. It is suggested that the typical subtropical monsoon climate in South China, cool and dry in winter, hot and humid in summer, may play a key role in controlling the source seasonality (by enhancing vehicle exhaust in winter, ground evaporation in summer), and hence the ambient concentrations of PAHs in the air.

  4. Utilization and preference rating of various subtropical pasture ...

    African Journals Online (AJOL)

    The percentage utilization and preference demonstrated by Bonsmara beef cows was measrued twice (December 1976 and March 1977) on 18 subtropical grasses, legumes and grass-legume mixtures under supplemental spray irrigation. Clipping before and after grazing, with a two to three day period of stay, was carried ...

  5. Environmental control of flowering in tropical - subtropical grasses ...

    African Journals Online (AJOL)

    Tropical-subtropical grasses have shown a wide range of response to photoperiod. Some of the response patterns which they exhibit are extremely complex and often seem unrelated to the conditions to which the plants are adapted. However, there is an increasing realisation of the possible role of factors of the ...

  6. Thermodynamic Environments Supporting Extreme Convection in Subtropical South America

    Science.gov (United States)

    Rasmussen, K. L.; Trier, S. B.

    2015-12-01

    Extreme convection tends to form in the vicinity of mountain ranges, and the Andes in subtropical South America help spawn some of the most intense convection in the world. Subsequent to initiation, the convection often evolves into propagating mesoscale convective systems (MCSs) similar to those seen over the U.S. Great Plains and produces damaging tornadoes, hail, and floods across a wide agricultural region. In recent years, studies on the nature of convection in subtropical South America using spaceborne radar data have elucidated key processes responsible for their extreme characteristics, including a strong relationship between the Andes topography and convective initiation. Building on previous work, an investigation of the thermodynamic environment supporting some of the deepest convection in the world will be presented. In particular, an analysis of the thermodynamic destabilization in subtropical South America, which considers the parcel buoyancy minimum for conditionally unstable air parcels, will be presented. Additional comparisons between the nocturnal nature and related diurnal cycle of MCSs in subtropical South America the U.S. Great Plains will provide insights into the processes controlling MCS initiation and upscale growth.

  7. Impact of erosion in the taluses of subtropical orchard terraces

    NARCIS (Netherlands)

    Duran Zuazo, V.H.; Ruiz, J.A.; Raya, A.M.; Tarifa, D.F.

    2005-01-01

    The coast of the provinces of Granada and Malaga (SE Spain) are economically important areas for the subtropical fruit cultivation. The climate is characterized by heavy periodic rainfall, which is one of the main factors responsible for soil erosion in this agroecosystem. However, the erosion

  8. Buoyancy-stirring interactions in a subtropical embayment: a ...

    African Journals Online (AJOL)

    Maputo Bay, on the coast of Mozambique, is a tidally energetic, subtropical embayment in a region subjected to strong seasonal rainfall. Data from moored current meters, tide gauges and monthly bay-wide surveys were used to characterise the evolution of the density structure on seasonal, fortnightly and semi-diurnal ...

  9. Air pollution

    International Nuclear Information System (INIS)

    Anon.

    2008-01-01

    Air pollution has accompanied and developed with the industrial age, since its beginnings. This very complete review furnishes the toxicological data available for the principal pollutants and assesses the epidemiologic studies thus far conducted. It also describes European regulations and international commitments for the reduction of emissions. (author)

  10. Glaucoma Drainage Device Erosion Following Ptosis Surgery.

    Science.gov (United States)

    Bae, Steven S; Campbell, Robert J

    2017-09-01

    To highlight the potential risk of glaucoma drainage device erosion following ptosis surgery. Case report. A 71-year-old man underwent uncomplicated superotemporal Ahmed glaucoma valve implantation in the left eye in 2008. Approximately 8 years later, the patient underwent bilateral ptosis repair, which successfully raised the upper eyelid position. Three months postoperatively, the patient's glaucoma drainage implant tube eroded through the corneal graft tissue and overlying conjunctiva to become exposed. A graft revision surgery was successfully performed with no further complications. Caution and conservative lid elevation may be warranted when performing ptosis repair in patients with a glaucoma drainage implant, and patients with a glaucoma implant undergoing ptosis surgery should be followed closely for signs of tube erosion.

  11. GEOMORPHOLOGIC ANALYSIS OF DRAINAGE NETWORKS ON MARS

    Directory of Open Access Journals (Sweden)

    KERESZTURI ÁKOS

    2012-06-01

    Full Text Available Altogether 327 valleys and their 314 cross-sectional profiles were analyzed on Mars, including width, depth, length, eroded volume, drainage and spatial density, as well as the network structure.According to this systematic analysis, five possible drainage network types were identified such as (a small valleys, (b integrated small valleys, (c individual, medium-sized valleys, (d unconfined,anastomosing outflow valleys, and (e confined outflow valleys. Measuring their various morphometric parameters, these five networks differ from each other in terms of parameters of the eroded volume, drainage density and depth values. This classification is more detailed than those described in the literature previously and correlated to several numerical parameters for the first time.These different types were probably formed during different periods of the evolution of Mars, and sprung from differently localized water sources, and they could be correlated to similar fluvialnetwork types from the Earth.

  12. Radiological management of abdominal surgical drainages

    International Nuclear Information System (INIS)

    Miotto, D.; Viglione, C.; Chiesura Corona, M.

    1987-01-01

    The authors consider their early results in radiological drainage management of abscesses and fistulas complicating abdominal surgery by integrated use of angiographic materials and interventional methods. Twenty-five patients, affected by isolated (32%) or communicating (68%) abscesses, were treated. Cavity obliteration and clinical recovery were obtained in 18 patients (72%), partial success in 1 (4%); a patient was treated unsuccessfully. Five patients were not evaluated because they died or underwent surgery again. Average drainage intervall was 54 days. Drainage management was carried out by replacement of surgical catheters and fibrin occlusion. Fibrin occlusion was performed in 7 patients with the following results: 3 successes, one partial success and one failure. Two cases were not evaluated. Although a comparison with a control group was not performed, the authors consider the procedure a safe, economic and simple method for abdominal abscess management

  13. Percutaneous epidural drainage through a burr hole

    Directory of Open Access Journals (Sweden)

    Priscila M Falsarella

    2016-01-01

    Full Text Available Intracranial extradural collection may cause an increase in intracranial pressure, requiring rapid emergency treatment to reduce morbidity and mortality. We described an alternative CT-guided percutaneous access for extradural collection drainage. We report a case of a patient with previous craniectomy for meningioma ressection who presented to the Emergency Department with symptoms of intracranial hypertension. Brains CT showed a extradural collection with subfalcine herniation. After multidisciplinary discussion a CT-guided percutaneous drainage through previous burr hole was performed. The patient was discharged after 36 hours of admission, without further symptoms. We describe a safe and effective alternative percutaneous access for extradural collection drainage in patients with previous burr hole.

  14. Endoscopic Ultrasound-Guided Biliary Drainage

    International Nuclear Information System (INIS)

    Artifon, Everson L.A.; Ferreira, Fla'vio C.; Sakai, Paulo

    2012-01-01

    To demonstrate a comprehensive review of published articles regarding endoscopic ultrasound (EUS)-guided biliary drainage. Review of studies regarding EUS-guided biliary drainage including case reports, case series and previous reviews. EUS-guided hepaticogastrostomy, coledochoduodenostomy and choledoantrostomy are advanced biliary and pancreatic endoscopy procedures, and together make up the echo-guided biliary drainage. Hepaticogastrostomy is indicated in cases of hilar obstruction, while the procedure of choice is the coledochoduodenostomy or choledochoantrostomy in distal lesions. Both procedures must be performed only after unsuccessful ERCPs. The indication of these procedures must be made under a multidisciplinary view while sharing information with the patient or legal guardian. Hepaticogastrostomy and coledochoduodenostomy or choledochoantrostomy are feasible when performed by endoscopists with expertise in biliopancreatic endoscopy. Advanced echo-endoscopy should currently be performed under a rigorous protocol in educational institutions.

  15. Comparison of Natural Drainage Group and Negative Drainage Groups after Total Thyroidectomy: Prospective Randomized Controlled Study

    Science.gov (United States)

    Woo, Seung Hoon; Kim, Jin Pyeong; Park, Jung Je; Shim, Hyun Seok; Lee, Sang Ha; Lee, Ho Joong; Won, Seong Jun; Son, Hee Young; Kim, Rock Bum

    2013-01-01

    Purpose The aim of this study was to compare a negative pressure drain with a natural drain in order to determine whether a negative pressure drainage tube causes an increase in the drainage volume. Materials and Methods Sixty-two patients who underwent total thyroidectomy for papillary thyroid carcinoma (PTC) were enrolled in the study between March 2010 and August 2010 at Gyeongsang National University Hospital. The patients were prospectively and randomly assigned to two groups, a negative pressure drainage group (n=32) and natural drainage group (n=30). Every 3 hours, the volume of drainage was checked in the two groups until the tube was removed. Results The amount of drainage during the first 24 hours postoperatively was 41.68±3.93 mL in the negative drain group and 25.3±2.68 mL in the natural drain group (pdrainage at postoperative day 3 was not statistically different between the two groups. In addition, the vocal cord palsy and temporary and permanent hypocalcemia were not different between the two groups. Conclusion These results indicate that a negative pressure drain may increase the amount of drainage during the first 24-48 hours postoperatively. Therefore, it is not necessary to place a closed suction drain when only a total thyroidectomy is done. PMID:23225820

  16. Direct Evidence for PCB Destruction in the Subtropical Troposphere by OH Radicals

    Science.gov (United States)

    Mandalakis, M.; Berresheim, H.; Stephanou, E.

    2003-04-01

    Although polychlorinated biphenyls (PCBs) production and use were banned by the mid-1970s, PCBs are ubiquitous pollutants in nearly all environmental compartments. Because of their high persistence and toxicity PCBs can pose toxic effects on animals and humans, decades after their release into the environment. It has been supported that warm temperatures at the tropical and subtropical regions of the earth favor the volatilization of PCBs, which are subsequently transported to colder areas of high latitude. This process, known as "global distillation effect", could cause an enhancement of PCB concentrations in the plant biomass and the marine mammals of Earth's polar regions. It has been experimentally established, that chemical reactions of PCBs with OH radicals might be the dominant loss processes in the atmosphere1. Nevertheless, PCBs atmospheric removal by OH radicals has never been positively demonstrated under real atmospheric conditions, mainly due to the difficulties to measure simultaneously the concentration of OH radicals and PCBs in the atmosphere. By applying elaborated sampling and analytical techniques2,3, under real atmospheric conditions, we achieved the simultaneous determination of OH radicals and PCBs congeners and demonstrated for the first time that PCB removal from the troposphere of subtropical regions is due to a large extent to reactions with OH radicals. References 1. Anderson, P. N. &Hites, R. A. OH radical reactions: The major removal pathway for polychlorinated biphenyls from the atmosphere. Environ. Sci. Technol. 30, 1756-1763 (1996). 2. Berresheim, H., Elste, T., Plass-Dülmer, C., Eisele, F. L. &Tanner, D. J. Chemical ionization mass spectrometer for long-term measurements of atmospheric OH and H2SO4. Int. J. Mass Spectrom. 202, 91-109 (2000). 3. Mandalakis, M., M. Tsapakis, and E.G. Stephanou, Optimization and application of high-resolution gas chromatography with ion trap tandem mass spectrometry to the determination of

  17. The nitrate export in subtropical mountainous catchment: implication for land use change impact

    Science.gov (United States)

    Huang, J.-C.; Lee, T.-Y.; Kao, S.-J.; Hsu, S.-C.; Lin, H.-J.; Peng, T.-R.

    2010-12-01

    Agricultural activity is the dominant factor affecting water quality and nitrate export, which causes eutrophication and episodic acidification in downstream water bodies (e.g., reservoirs, lakes, and coastal zones). However, in subtropical mountainous areas such environmental impact due to the land use change was rarely documented. In this study, we investigated 16 sub-catchments during 2007 and 2008 in the Chi-Chia-Wan catchment where is the sole habitat for the endemic species, Formosan landlocked salmon (Oncorhynchus masou formosanus). The results revealed that the NO3-N concentration in pristine catchments varied from 0.144 to 0.151 mg/L without significant seasonal variation. This concentration was comparable with other forestry catchments around the world. However, the annual nitrate export was around 375.3-677.1 kg/km2/yr, much higher than other catchments due to the greater amount of rainfall. This is an important baseline for comparisons with other climate areas. As for the impact of agricultural activities, the catchments with some human disturbance, ~5.2% of the catchment area, might yield 5947.2 kg N/km2/yr - over 10-times higher than that of pristine catchment. Such high export caused by such a low level of disturbance might indicate that subtropical mountainous area is highly sensitive to agricultural activities. As for the land-use effect on nitrate yield, the forestry land might yield 488.5 ± 325.1 kg/km2/yr and the vegetable farm could yield 298 465.4 ± 3347.2 kg/km2/yr - 1000-times greater than the forestry. The estimated nitrate yields for land use classes were a crucial basis and useful for the land manager to assess the possible impacts (e.g., non-point source pollution evaluation and the recovery of land expropriation).

  18. Removal of selenium from contaminated agricultural drainage water by nanofiltration membranes

    Science.gov (United States)

    Kharaka, Y.K.; Ambats, G.; Presser, T.S.; Davis, R.A.

    1996-01-01

    Seleniferous agricultural drainage wastewater has become a new major source of pollution in the world. In the USA, large areas of farmland in 17 western states, generate contaminated salinized drainage with Se concentrations much higher than 5 ??g/l, the US Environmental Protection Agency water-quality criterion for the protection of aquatic life; Se values locally reach 4200 ??g/l in western San Joaquin Valley, California. Wetland habitats receiving this drainage have generally shown Se toxicosis in aquatic birds causing high rates of embryonic deformity and mortality, or have indicated potential ecological damage. Results of our laboratory flow experiments indicate that nanofiltration, the latest membrane separation technology, can selectively remove > 95% of Se and other multivalent anions from > 90% of highly contaminated water from the San Joaquin Valley, California. Such membranes yield greater water output and require lower pressures and less pretreatment, and therefore, are more cost effective than traditional reverse osmosis membranes. Nanofiltration membranes offer a potential breakthrough for the management of Se contaminated wastes not only from agricultural drainage, but from other sources also.

  19. The effect of climate change on urban drainage: an evaluation based on regional climate model simulation.

    Science.gov (United States)

    Grum, M; Jørgensen, A T; Johansen, R M; Linde, J J

    2006-01-01

    That we are in a period of extraordinary rates of climate change is today evident. These climate changes are likely to impact local weather conditions with direct impacts on precipitation patterns and urban drainage. In recent years several studies have focused on revealing the nature, extent and consequences of climate change on urban drainage and urban runoff pollution issues. This study uses predictions from a regional climate model to look at the effects of climate change on extreme precipitation events. Results are presented in terms of point rainfall extremes. The analysis involves three steps: Firstly, hourly rainfall intensities from 16 point rain gauges are averaged to create a rain gauge equivalent intensity for a 25 x 25 km square corresponding to one grid cell in the climate model. Secondly, the differences between present and future in the climate model is used to project the hourly extreme statistics of the rain gauge surface into the future. Thirdly, the future extremes of the square surface area are downscaled to give point rainfall extremes of the future. The results and conclusions rely heavily on the regional model's suitability in describing extremes at timescales relevant to urban drainage. However, in spite of these uncertainties, and others raised in the discussion, the tendency is clear: extreme precipitation events effecting urban drainage and causing flooding will become more frequent as a result of climate change.

  20. Preliminary appraisal of the geohydrologic aspects of drainage wells, Orlando area, central Florida

    Science.gov (United States)

    Kimrey, Joel O.

    1978-01-01

    The Floridan aquifer contains two highly transmissive cavernous zones in the Orlando area: an upper producing zone about 150-600 feet below land surface; and a lower producing zone about 1,100-1,500 feet below land surface. Natural head differences are downward and there is hydraulic connection between the two producing zones. Drainage wells are finished open-end into the upper producing zone and emplace surface waters directly into that zone by gravity. Quantitatively, their use constitutes an effective method of artificial recharge. Their negative aspects relate to the probably poor, but unknown, quality of the recharge water. Caution is suggested in drawing definite and final conclusions on the overall geohydrologic and environmental effects of drainage wells prior to the collection and interpretation of a considerable quantity of new data. Though few ground-water pollution problems have been documented to date, the potential for such pollution should be seriously considered in light of the prob-able continuing need to use drainage wells; the probable volumes and quality of water involved; and the hydraulic relations between the two producing zones.

  1. Drainage: 'prevention is better than cure'.

    Science.gov (United States)

    Reilly, Nick

    2012-10-01

    Excellent standards of cleanliness are more important for healthcare facilities than in virtually every other type of building, and well-managed drainage systems play a crucial part in this. business and commercial, utilities, public sector, and facilities management clients. Nick Reilly, director at UKDN Waterflow, discusses best practice in this area for healthcare estates managers.

  2. Preoperative biliary drainage for pancreatic cancer

    NARCIS (Netherlands)

    van Heek, N. T.; Busch, O. R.; van Gulik, T. M.; Gouma, D. J.

    2014-01-01

    This review is to summarize the current knowledge about preoperative biliary drainage (PBD) in patients with biliary obstruction caused by pancreatic cancer. Most patients with pancreatic carcinoma (85%) will present with obstructive jaundice. The presence of toxic substances as bilirubin and bile

  3. Preoperative biliary drainage for pancreatic cancer.

    Science.gov (United States)

    Van Heek, N T; Busch, O R; Van Gulik, T M; Gouma, D J

    2014-04-01

    This review is to summarize the current knowledge about preoperative biliary drainage (PBD) in patients with biliary obstruction caused by pancreatic cancer. Most patients with pancreatic carcinoma (85%) will present with obstructive jaundice. The presence of toxic substances as bilirubin and bile salts, impaired liver function and altered nutritional status due to obstructive jaundice have been characterized as factors for development of complications after surgery. Whereas PBD was to yield beneficial effects in the experimental setting, conflicting results have been observed in clinical studies. The meta-analysis from relative older studies as well as more importantly a recent clinical trial showed that PBD should not be performed routinely. PBD for patients with a distal biliary obstruction is leading to more serious complications compared with early surgery. Arguments for PBD have shifted from a potential therapeutic benefit towards a logistic problem such as patients suffering from cholangitis and severe jaundice at admission or patients who need extra diagnostic tests, or delay in surgery due to a referral pattern or waiting list for surgery as well as candidates for neoadjuvant chemo(radio)therapy. If drainage is indicated in these patients it should be performed with a metal stent to reduce complications after the drainage procedure such as stent occlusion and cholangitis. Considering a change towards more neoadjuvant therapy regimes improvement of the quality of the biliary drainage concept is still important.

  4. CT guidance of percutaneous hepatic abscess drainage

    International Nuclear Information System (INIS)

    Li Jiahua; Zhang Jiaxing; Cao Chuanwu; Li Maoquan; Lu Fuming; Zheng Manhua

    2008-01-01

    Objective: To discuss the method and effectiveness of percutaneous drainage for hepatic abscess under CT guidance. Methods: 20 patients were enrolled into this retrospective research, including 13 males and 7 females with age form 18 to 84 yrs. The diagnosis were made by clinical examination, laboratory test and CT imaging. Hepatic abscess focus involved right lobe in 9 cases, left lobe of 6 cases, both lobes with 5 cases. All patients received percutaneous abscess drainage subsequently. Results: There were 14 cases with solitary abscess, in which 9 disappeared completely after single procedure of aspiration under CT guidance, 1 disappeared after twice aspirations. Multiple or multi-lobular abscesses were found in six cases, which were treated by aspirating the larger one first or by splitting multi-aspiration. In all cases, drainage catheters were placed and lavage was done with a mean time of 19.2 days together with intravenous antibiotics. There was no recurrence until the end-piont of research. Conclusions: Percutaneous CT-guided aspiration and drainage is an effective way in the treatment of hepatic abscess. (authors)

  5. Peritoneal drainage for newborn intestinal perforation: primary ...

    African Journals Online (AJOL)

    Keywords: intestinal perforation in newborn, necrotizing enterocolitis, primary peritoneal drainage. Department of Surgery, Paul L. Foster School of Medicine, Texas Tech University. HSC, El Paso, Texas, USA. Correspondence to Donald E. Meier, MD, Department of Surgery, Paul L. Foster. School of Medicine, Texas Tech ...

  6. CASE REPORT CAS Transcolonic pelvic abscess drainage

    African Journals Online (AJOL)

    Although there are a number of reports of successful drainage of deep pelvic collections using transrectal, transvaginal, transgluteal and other routes,1,2 some collections remain difficult to access. An elderly female patient with renal failure presented with features of sepsis following a partial sigmoid colectomy for ...

  7. Urban drainage models - making uncertainty analysis simple

    DEFF Research Database (Denmark)

    Vezzaro, Luca; Mikkelsen, Peter Steen; Deletic, Ana

    2012-01-01

    There is increasing awareness about uncertainties in modelling of urban drainage systems and, as such, many new methods for uncertainty analyses have been developed. Despite this, all available methods have limitations which restrict their widespread application among practitioners. Here, a modif...

  8. Selecting the drainage method for agricultural land

    NARCIS (Netherlands)

    Bos, M.G.

    2001-01-01

    To facilitate crop growth excess water should be drained from the rooting zone to allow root development of the crop and from the soil surface to facilitate access to the field. Basically, there are three drainage methods from which the designer can select being; surface drains, pumped tube wells

  9. Recovery of water from acid mine drainage

    CSIR Research Space (South Africa)

    Mulopo, J

    2010-10-01

    Full Text Available The reaction rate of sulphate removal from acid mine drainage using barium carbonate was studied for various pH, calcium concentration, and BaCO3/SO42 feed ratios in batch studies. Process synthesis concepts were used to investigate the interaction...

  10. The Heimlich Valve for Pleural Cavity Drainage

    African Journals Online (AJOL)

    The ANNALS of AFRICAN SURGERY | www.annalsofafricansurgery.com. The ANNALS of ... valves allow for outpatient management of pleural drainage ... anesthesia. Where the procedure was not tolerable or the patient was too young to co-operate, additional sedation was used. Following insertion, all chest tubes.

  11. Ozone Pollution

    Science.gov (United States)

    Known as tropospheric or ground-level ozone, this gas is harmful to human heath and the environment. Since it forms from emissions of volatile organic compounds (VOCs) and nitrogen oxides (NOx), these pollutants are regulated under air quality standards.

  12. Light Pollution

    Science.gov (United States)

    Riegel, Kurt W.

    1973-01-01

    Outdoor lighting is light pollution which handicaps certain astronomical programs. Protective measures must be adopted by the government to aid observational astronomy without sacrificing legitimate outdoor lighting needs. (PS)

  13. Combatting operational pollution from offshore petroleum activities: international legal regime

    International Nuclear Information System (INIS)

    Vinogradov, S.V.; Wagner, J.P.

    1997-01-01

    Existing global and regional rules and regulations, and regulatory trends, aimed at curbing pollution associated with the normal operation of offshore oil and gas installations are assessed. The designation 'operational pollution' is used to cover a variety of discharges including: oil produced in water; contaminated drill cuttings and muds; sewage; garbage; deck drainage; naturally occurring materials such as radionuclides, heavy metals and aromatics; atmospheric emissions, principally CO 2 , SO x , NO x , CH 4 and volatile organic compounds. The main focus of regulatory attention at present is platform drainage, offshore processing drainage, production water discharge, and displacement discharge. The legal framework considered extends to the appropriate global and regional treaties, ''soft law'' instruments and recommendations. (UK)

  14. Environmental pollution

    International Nuclear Information System (INIS)

    Hanif, J.; Hanif, M.I.

    1997-01-01

    The third proceedings of National Symposium on Modern Trends in Contemporary Chemistry was held in Islamabad, Pakistan from February 24-26, 1997. In this symposium more than 220 scientists, engineers and technologist were registered from 11 universities, 17 research organisations and 8 non-governmental organisation including some commercial establishments. The symposium was divided into five technical sessions on hydro spheric pollution, atmospheric pollution, bio spheric pollution, lithospheric pollution and impact assessment and environmental education. Environmental and ecology are so interdependent that any change in the balance due to natural and man made cause may result in a disaster, flood, fire, earthquake, epidemic, population explosion etc. are the natural ways of unbalancing our ecosystem. The scope of this symposium includes: 1) Review the chemistry and the chemical techniques like polarography, coulometry, HPLC, GC-MS, NAA, XRF, AAS, AES etc. involved in the assessment monitoring and control of various pollutions. 2) Propose sampling, transportation, measurement and standardization procedures. 3) Collaboration in scientific data collection. 4) Mutual consultation for management of the pollution problem in a cost effective manner. 5) sharing knowledge and experience with various environmental protection groups both in public and private sector. (A.B.)

  15. Topological Analysis of Urban Drainage Networks

    Science.gov (United States)

    Yang, Soohyun; Paik, Kyungrock; McGrath, Gavan; Rao, Suresh

    2016-04-01

    Urban drainage networks are an essential component of infrastructure, and comprise the aggregation of underground pipe networks carrying storm water and domestic waste water for eventual discharge to natural stream networks. Growing urbanization has contributed to rapid expansion of sewer networks, vastly increasing their complexity and scale. Importance of sewer networks has been well studied from an engineering perspective, including resilient management, optimal design, and malfunctioning impact. Yet, analysis of the urban drainage networks using complex networks approach are lacking. Urban drainage networks consist of manholes and conduits, which correspond to nodes and edges, analogous to junctions and streams in river networks. Converging water flows in these two networks are driven by elevation gradient. In this sense, engineered urban drainage networks share several attributes of flows in river networks. These similarities between the two directed, converging flow networks serve the basis for us to hypothesize that the functional topology of sewer networks, like river networks, is scale-invariant. We analyzed the exceedance probability distribution of upstream area for practical sewer networks in South Korea. We found that the exceedance probability distributions of upstream area follow power-law, implying that the sewer networks exhibit topological self-similarity. The power-law exponents for the sewer networks were similar, and within the range reported from analysis of natural river networks. Thus, in line with our hypothesis, these results suggest that engineered urban drainage networks share functional topological attributes regardless of their structural dissimilarity or different underlying network evolution processes (natural vs. engineered). Implications of these findings for optimal design of sewer networks and for modeling sewer flows will be discussed.

  16. Ground Pollution Science

    International Nuclear Information System (INIS)

    Oh, Jong Min; Bae, Jae Geun

    1997-08-01

    This book deals with ground pollution science and soil science, classification of soil and fundamentals, ground pollution and human, ground pollution and organic matter, ground pollution and city environment, environmental problems of the earth and ground pollution, soil pollution and development of geological features of the ground, ground pollution and landfill of waste, case of measurement of ground pollution.

  17. Ground water pollution: General studies. (Latest citations from the NTIS bibliographic database). Published Search

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-05-01

    The bibliography contains citations concerning sources, contaminant transport, and monitoring of pollutants in aquifers. Topics include pollution characterization from landfills and mine drainage, descriptions of study programs undertaken by specific states, and Superfund site studies of contaminated areas. The uses of mathematical models are also discussed. (Contains 50-250 citations and includes a subject term index and title list.) (Copyright NERAC, Inc. 1995)

  18. 77 FR 21870 - National Oil and Hazardous Substances Pollution Contingency Plan; National Priorities List...

    Science.gov (United States)

    2012-04-12

    ... and Hazardous Substances Pollution Contingency Plan; National Priorities List: Deletion of the A & F... constitutes Appendix B of 40 CFR part 300, which is the National Oil and Hazardous Substances Pollution... surrounding soil and water drainage pathway to the Embarras River. In addition, some of the steel storage...

  19. Exploring Agricultural Drainage's Influence on Wetland and Watershed Connectivity

    Science.gov (United States)

    Artificial agricultural drainage (i.e. surface ditches or subsurface tile) is an important agricultural management tool. Artificial drainage allows for timely fieldwork and adequate root aeration, resulting in greater crop yields for farmers. This practice is widespread throughou...

  20. The Effects of Coarse Particles on Daily Mortality: A Case-Crossover Study in a Subtropical City, Taipei, Taiwan.

    Science.gov (United States)

    Cheng, Meng-Hsuan; Chiu, Hui-Fen; Yang, Chun-Yuh

    2016-03-22

    Many studies have examined the effects of air pollution on daily mortality over the past two decades. However, information on the relationship between levels of coarse particles (PM2.5-10) and daily mortality is relatively sparse due to the limited availability of monitoring data. Furthermore, the results are inconsistent. In the current study, the association between coarse particle levels and daily mortality in Taipei, Taiwan's largest city, which has a subtropical climate, was undertaken for the period 2006-2008 using a time-stratified case-crossover analysis. For the single pollutant model (without adjustment for other pollutants), PM2.5-10 showed statistically significant association with total mortality both on warm and cool days, with an interquartile range increase associated with a 11% (95% CI = 6%-17%) and 4% (95% CI = 1%-7%) rise in number of total deaths, respectively. In two-pollutant models, PM2.5-10 remained significant effects on total mortality after the inclusion of SO₂ and O₃ both on warm and cool days. We observed no significant associations between PM2.5-10 and daily mortality from respiratory diseases both on warm and cool days. For daily mortality from circulatory diseases, the effect of PM2.5-10 remained significant when SO₂ or O₃ was added in the regression model both on warm and cool days. Future studies of this type in cities with varying climates and cultures are needed.

  1. Response of epiphytic bryophytes to simulated N deposition in a subtropical montane cloud forest in southwestern China.

    Science.gov (United States)

    Song, Liang; Liu, Wen-Yao; Ma, Wen-Zhang; Qi, Jin-Hua

    2012-11-01

    A field manipulation experiment was conducted in a subtropical montane cloud forest in southwestern China to determine the possible responses of epiphytic bryophytes to increasing nitrogen (N) deposition from community to physiology level, and to find sensitive epiphytic bryophytes that may be used as indicators for assessing the degree of N pollution. N addition had significantly negative effects on species richness and cover of the epiphytic bryophyte community. Harmful effects of high N loads were recorded for chlorophyll, growth, and vitality of the species tested. The decline of some epiphytic bryophytes may result from detrimental effects on degradation to photosynthetic pigments. Bazzania himalayana (Mitt.) Schiffn., Bazzania ovistipula (Steph.) Mizut., and Homaliodendron flabellatum (Sm.) Fleisch. are candidates in atmospheric nitrogen monitoring. Epiphytic bryophytes in the montane cloud forest are very sensitive to increasing N deposition and often difficult to recover once they have been destroyed, providing early detection of enhanced N pollution for trees or even the whole forest ecosystem. The inference that increasing N pollution may lead to loss of biodiversity is a concern to the developing economy in western China, and should alert the government to the adverse impacts caused by increased industrial pollution during the process of China's West Development.

  2. Land drainage and restoration of land after NCB opencast mining

    Energy Technology Data Exchange (ETDEWEB)

    Bragg, N.

    The author outlines the MAFF Field Drainage Research Unit's research into drainage of reinstated land. Current investigations have aimed at identifying the problems of reinstated soil and how they affect drainage design. Experiments on efficiency of permeable field drains and non-permeable field drains are mentioned. Further work is needed to examine long-term effects of storage on soil structure and whether existing drainage can be revitalised by secondary treatment.

  3. Processing potential of jellies from subtropical loquat cultivars

    Directory of Open Access Journals (Sweden)

    Paula Nogueira CURI

    2016-01-01

    Full Text Available Abstract To increase the availability to consumers and add more value to loquat (Eriobotrya japonica Lindl., which is a very perishable and seasonal fruit, and in order to identify which cultivars grown in subtropical regions are more suitable for jelly processing, the objective of this study was to evaluate the influence of different loquat cultivars (Fukuhara, Kurisaki, Mizumo, Mizuho and Mizauto grown in subtropical regions of Brazil on the physicochemical characteristics, rheological properties and sensory acceptance of the resulting jelly. Based on sensory acceptance the most suitable loquat cultivars for jelly processing are Kurisaki and Mizuho. In this study it was found that the consumer prefers a more acidic, less sweet, less firm or softer loquat jelly, clearer with a more intense red color.

  4. Atlantic Meridional Overturning Circulation slowdown cooled the subtropical ocean.

    Science.gov (United States)

    Cunningham, Stuart A; Roberts, Christopher D; Frajka-Williams, Eleanor; Johns, William E; Hobbs, Will; Palmer, Matthew D; Rayner, Darren; Smeed, David A; McCarthy, Gerard

    2013-12-16

    [1] Observations show that the upper 2 km of the subtropical North Atlantic Ocean cooled throughout 2010 and remained cold until at least December 2011. We show that these cold anomalies are partly driven by anomalous air-sea exchange during the cold winters of 2009/2010 and 2010/2011 and, more surprisingly, by extreme interannual variability in the ocean's northward heat transport at 26.5°N. This cooling driven by the ocean's meridional heat transport affects deeper layers isolated from the atmosphere on annual timescales and water that is entrained into the winter mixed layer thus lowering winter sea surface temperatures. Here we connect, for the first time, variability in the northward heat transport carried by the Atlantic Meridional Overturning Circulation to widespread sustained cooling of the subtropical North Atlantic, challenging the prevailing view that the ocean plays a passive role in the coupled ocean-atmosphere system on monthly-to-seasonal timescales.

  5. A Comparison of Preoperative Biliary Drainage Methods for Perihilar Cholangiocarcinoma: Endoscopic versus Percutaneous Transhepatic Biliary Drainage.

    Science.gov (United States)

    Kim, Kwang Min; Park, Ji Won; Lee, Jong Kyun; Lee, Kwang Hyuck; Lee, Kyu Taek; Shim, Sang Goon

    2015-11-23

    Controversy remains over the optimal approach to preoperative biliary drainage in patients with resectable perihilar cholangiocarcinoma. We compared the clinical outcomes of endoscopic biliary drainage (EBD) with those of percutaneous transhepatic biliary drainage (PTBD) in patients undergoing preoperative biliary drainage for perihilar cholangiocarcinoma. A total of 106 consecutive patients who underwent biliary drainage before surgical treatment were divided into two groups the PTBD group (n=62) and the EBD group (n=44). Successful drainage on the first attempt was achieved in 36 of 62 patients (58.1%) with PTBD, and in 25 of 44 patients (56.8%) with EBD. There were no significant differences in predrainage patient demographics and decompression periods between the two groups. Procedure-related complications, especially cholangitis and pancreatitis, were significantly more frequent in the EBD group than the PTBD group (PTBD vs EBD 22.6% vs 54.5%, p<0.001). Two patients (3.8%) in the PTBD group experienced catheter tract implantation metastasis after curative resection during the follow-up period. EBD was associated with a higher risk of procedure-related complications than PTBD. These complications were managed properly without severe morbidity; however, in the PTBD group, there were two cases of cancer dissemination along the catheter tract.

  6. The foam drainage equation for drainage dynamics in unsaturated porous media

    Science.gov (United States)

    Lehmann, P.; Hoogland, F.; Assouline, S.; Or, D.

    2017-07-01

    Similarity in liquid-phase configuration and drainage dynamics of wet foam and gravity drainage from unsaturated porous media expands modeling capabilities for capillary flows and supplements the standard Richards equation representation. The governing equation for draining foam (or a soil variant termed the soil foam drainage equation—SFDE) obviates the need for macroscopic unsaturated hydraulic conductivity function by an explicit account of diminishing flow pathway sizes as the medium gradually drains. The study provides new and simple analytical expressions for drainage rates and volumes from unsaturated porous media subjected to different boundary conditions. Two novel analytical solutions for saturation profile evolution were derived and tested in good agreement with a numerical solution of the SFDE. The study and the proposed solutions rectify the original formulation of foam drainage dynamics of Or and Assouline (2013). The new framework broadens the scope of methods available for quantifying unsaturated flow in porous media, where the intrinsic conductivity and geometrical representation of capillary drainage could improve understanding of colloid and pathogen transport. The explicit geometrical interpretation of flow pathways underlying the hydraulic functions used by the Richards equation offers new insights that benefit both approaches.

  7. Uncertainty quantification and integration of machine learning techniques for predicting acid rock drainage chemistry: a probability bounds approach.

    Science.gov (United States)

    Betrie, Getnet D; Sadiq, Rehan; Morin, Kevin A; Tesfamariam, Solomon

    2014-08-15

    Acid rock drainage (ARD) is a major pollution problem globally that has adversely impacted the environment. Identification and quantification of uncertainties are integral parts of ARD assessment and risk mitigation, however previous studies on predicting ARD drainage chemistry have not fully addressed issues of uncertainties. In this study, artificial neural networks (ANN) and support vector machine (SVM) are used for the prediction of ARD drainage chemistry and their predictive uncertainties are quantified using probability bounds analysis. Furthermore, the predictions of ANN and SVM are integrated using four aggregation methods to improve their individual predictions. The results of this study showed that ANN performed better than SVM in enveloping the observed concentrations. In addition, integrating the prediction of ANN and SVM using the aggregation methods improved the predictions of individual techniques. Copyright © 2014 Elsevier B.V. All rights reserved.

  8. FLORISTIC CHANGES IN A SUB-TROPICAL RAIN FOREST SUCCESSION

    Directory of Open Access Journals (Sweden)

    Rochadi Abdulhadi

    1992-02-01

    Full Text Available Floristic changes in a subtropical rain forest were assesed. Three regrowth forests aged 20 years, 50 years and 60 years and an undisturbed forest were sampled. The series of sites sho floristic changes that would be expected in a successional sequence. The regrowth forests were dominated by the secondary species but the primary species occur from the early stage. The oldest regrowth (60 year old-site was still well short of regaining its original condition.

  9. Convective initiation in the vicinity of the subtropical Andes

    Science.gov (United States)

    Rasmussen, K. L.; Houze, R.

    2014-12-01

    Extreme convection tends to form in the vicinity of mountain ranges, and the Andes in subtropical South America help spawn some of the most intense convection in the world. An investigation of the most intense storms for 11 years of TRMM Precipitation Radar (PR) data shows a tendency for squall lines to initiate and develop in this region with the canonical leading convective line/trailing stratiform structure. The synoptic environment and structures of the extreme convection and MCSs in subtropical South America are similar to those found in other regions of the world, especially the United States. In subtropical South America, however, the topographical influence on the convective initiation and maintenance of the MCSs is unique. A capping inversion in the lee of the Andes is important in preventing premature triggering. The Andes and other mountainous terrain of Argentina focus deep convective initiation in a narrow region. Subsequent to initiation, the convection often evolves into propagating mesoscale convective systems similar to those seen over the Great Plains of the U. S. and produces damaging tornadoes, hail, and floods across a wide agricultural region. Numerical simulations conducted with the NCAR Weather Research and Forecasting (WRF) Model extend the observational analysis and provide an objective evaluation of storm initiation, terrain effects, and development mechanisms. The simulated mesoscale systems closely resemble the storm structures seen by the TRMM Precipitation Radar as well as the overall shape and character of the storms shown in GOES satellite data. A sensitivity experiment with different configurations of topography, including both decreasing and increasing the height of the Andes Mountains, provides insight into the significant influence of orography in focusing convective initiation in this region. Lee cyclogenesis and a strong low-level jet are modulated by the height of the Andes Mountains and directly affect the character

  10. Nutrient leaching under zero tension in a subtropical clonal eucalypt ...

    African Journals Online (AJOL)

    Little is known about the effects of residue burning or retention on nutrient leaching during the inter-rotation of clonal Eucalyptus grown on the sandy soils of subtropical Zululand, South Africa. A study compared zero-tension nutrient leaching through the top metre of soil at depths of 0.15, 0.5 and 1.0 m in an undisturbed crop ...

  11. Estimating the benefits of improved drainage on pavement ...

    African Journals Online (AJOL)

    The drainage quality is an important parameter which affects the performance of highway pavements. In India, since last few years considerable importance has been given to the drainage as per of pavement. A poor quality of drainage results in premature deterioration of the pavement structure and necessitating large ...

  12. Role of Lithology and Rock Structure in Drainage Development in ...

    African Journals Online (AJOL)

    Lithology and Rock structure play a vital role in the development of Drainage Network in any drainage basin. The drainage patterns upon land surface develop as directed by the underlying lithology and rock structure. In fact, lithology and rock structure together shape the basin and are decisive parameters of nature and ...

  13. PASSIVE TREATMENT OF ACID ROCK DRAINAGE FROM A SUBSURFACE MINE

    Science.gov (United States)

    Acidic, metal-contaminated drainages are a critical problem facing many areas of the world. Acid rock drainage results when metal sulfide minerals, particularly pyrite, are oxidized by exposure to oxygen and water. The deleterious effects of these drainages on receiving streams a...

  14. Drainage of Splenic Abscess: A Case Report | Kombo | Nigerian ...

    African Journals Online (AJOL)

    ... and was managed by tube drainage. His post operative recovery was uneventful. Conclusion: Tube drainage of the splenic abscess is encouraged if there is easy access to the abscess and there is evidence of residual splenic tissue in the critically ill patient. Key Word: Tube drainage, splenic abscess, splenectomy.

  15. Cropping Systems and Climate Change in Humid Subtropical Environments

    Directory of Open Access Journals (Sweden)

    Ixchel M. Hernandez-Ochoa

    2018-02-01

    Full Text Available In the future, climate change will challenge food security by threatening crop production. Humid subtropical regions play an important role in global food security, with crop rotations often including wheat (winter crop and soybean and maize (summer crops. Over the last 30 years, the humid subtropics in the Northern Hemisphere have experienced a stronger warming trend than in the Southern Hemisphere, and the trend is projected to continue throughout the mid- and end of century. Past rainfall trends range, from increases up to 4% per decade in Southeast China to −3% decadal decline in East Australia; a similar trend is projected in the future. Climate change impact studies suggest that by the middle and end of the century, wheat yields may not change, or they will increase up to 17%. Soybean yields will increase between 3% and 41%, while maize yields will increase by 30% or decline by −40%. These wide-ranging climate change impacts are partly due to the region-specific projections, but also due to different global climate models, climate change scenarios, single-model uncertainties, and cropping system assumptions, making it difficult to make conclusions from these impact studies and develop adaptation strategies. Additionally, most of the crop models used in these studies do not include major common stresses in this environment, such as heat, frost, excess water, pests, and diseases. Standard protocols and impact assessments across the humid subtropical regions are needed to understand climate change impacts and prepare for adaptation strategies.

  16. Strong hydrological control on nutrient cycling of subtropical rainforests

    Science.gov (United States)

    Lin, T. C.; Chang, C. T.; Huang, J. C.; Wang, L.; Lin, N. H.

    2016-12-01

    Forest nutrient cycling is strongly controlled by both biological and hydrological factors. However, based on a close examination of earlier reports, we highlight the role of hydrological control on nutrient cycling at a global scale and is more important at humid tropical and subtropical forests. we analyzed the nutrient budget of precipitation input and stream water output from 1994 to 2013 in a subtropical forest in Taiwan and conducted a data synthesis using results from 32 forests across the globe. The results revealed that monthly input and output of ions were positively correlated with water quantity, indicating hydrological control on nutrient cycling. Hydrological control is also evident from the greater ions export via stream water during the warm and wet growing season. The synthesis also illustrates that strong hydrological control leads to lower nitrogen retention and greater net loss of base cations in humid regions, particularly in the humid tropical and subtropical forests. Our result is of great significance in an era of global climate change because climate change could directly affect ecosystem nutrient cycling particularly in the tropics through changes in patterns of precipitation regime.

  17. Filamentary structure in chemical tracer distributions near the subtropical jet following a wave breaking event

    Directory of Open Access Journals (Sweden)

    J. Ungermann

    2013-10-01

    Full Text Available This paper presents a set of observations and analyses of trace gas cross sections in the extratropical upper troposphere/lower stratosphere (UTLS. The spatially highly resolved (≈0.5 km vertically and 12.5 km horizontally cross sections of ozone (O3, nitric acid (HNO3, and peroxyacetyl nitrate (PAN, retrieved from the measurements of the CRISTA-NF infrared limb sounder flown on the Russian M55-Geophysica, revealed intricate layer structures in the region of the subtropical tropopause break. The chemical structure in this region shows an intertwined stratosphere and troposphere. The observed filaments in all discussed trace gases are of a spatial scale of less than 0.8 km vertically and about 200 km horizontally across the jet stream. Backward trajectory calculations confirm that the observed filaments are the result of a breaking Rossby wave in the preceding days. An analysis of the trace gas relationships between PAN and O3 identifies four distinct groups of air mass: polluted subtropical tropospheric air, clean tropical upper-tropospheric air, the lowermost stratospheric air, and air from the deep stratosphere. The tracer relationships further allow the identification of tropospheric, stratospheric, and the transitional air mass made of a mixture of UT and LS air. Mapping of these air mass types onto the geo-spatial location in the cross sections reveals a highly structured extratropical transition layer (ExTL. Finally, the ratio between the measured reactive nitrogen species (HNO3 + PAN + ClONO2 and O3 is analysed to estimate the influence of tropospheric pollution on the extratropical UTLS. In combination, these diagnostics provide the first example of a multi-species two-dimensional picture of the inhomogeneous distribution of chemical species within the UTLS region. Since Rossby wave breaking occurs frequently in the region of the tropopause break, these observed fine-scale filaments are likely ubiquitous in the region. The

  18. EFFECTIVENESS OF AUTOGENIC DRAINAGE VERSUS POSTURAL DRAINAGE ON OXYGEN SATURATION IN PATIENTS WITH CHRONIC BRONCHITIS WITH 15 MINUTES POST THERAPY

    OpenAIRE

    V. Kiran; Dr. Bhimasen .S; E. Mastanaiah; A. Thiruppathi

    2014-01-01

    Background: Patients with COPD will have more amount of secretions. To clear the secretions by using of different bronchial hygiene techniques like postural drainage and autogenic drainage technique, manual hyperventilation technique ,active cycle breathing technique .Hence in this study to compare the short-term effects of postural drainage with clapping (PD) and autogenic drainage (AD) on level of oxygen saturation in blood, and amount of sputum recovery. Methodology: The study was done ...

  19. Screening for exopolysaccharide-producing bacteria from sub-tropical polluted groundwater

    Directory of Open Access Journals (Sweden)

    R. FUSCONI

    Full Text Available A selection of exopolysaccharide (EPS -- producing bacterial strains was conducted in groundwater adjacent to an old controlled landfill in the City of São Carlos (São Paulo, Brazil. The strains were isolated in P and E media under aerobic and microaerophilic conditions at 25ºC. A total of 26 strains were isolated and based on the mucoid mode of the colonies, 6 were selected and their morphological, physiological and biochemical aspects were characterized. All strains presented pigmentation, ranging from yellow to orange and from pink to salmon, with a shiny glistening aspect in all tested media. Strains Lb, Lc and Lg, which excelled the others with regard to the mucoid mode of the colonies, were selected to be cultured in E medium with alternate sucrose and glucose as carbon sources in anaerobiosis at 25ºC to analyze the production of EPS. Strains Lc and Lg were classified as being of order Actinomycelates, suborder Corynebacterineae. Lg strain was identified as Gordonia polyisoprenivorans and Lc strain did not correspond to a known description and therefore a more detailed study is under preparation. Considering all ecological aspects and the metabolic potential associated with the microorganisms of the environment studied, as well as the capacity to produce pigment and EPS, and the presence of G. polyisoprenivorans, a rubber degrader bacterium, the potential of the groundwater analyzed is evident as a source of microorganisms to be utilized in studies related to environmental remediation.

  20. Screening for exopolysaccharide-producing bacteria from sub-tropical polluted groundwater

    Directory of Open Access Journals (Sweden)

    FUSCONI R.

    2002-01-01

    Full Text Available A selection of exopolysaccharide (EPS -- producing bacterial strains was conducted in groundwater adjacent to an old controlled landfill in the City of São Carlos (São Paulo, Brazil. The strains were isolated in P and E media under aerobic and microaerophilic conditions at 25ºC. A total of 26 strains were isolated and based on the mucoid mode of the colonies, 6 were selected and their morphological, physiological and biochemical aspects were characterized. All strains presented pigmentation, ranging from yellow to orange and from pink to salmon, with a shiny glistening aspect in all tested media. Strains Lb, Lc and Lg, which excelled the others with regard to the mucoid mode of the colonies, were selected to be cultured in E medium with alternate sucrose and glucose as carbon sources in anaerobiosis at 25ºC to analyze the production of EPS. Strains Lc and Lg were classified as being of order Actinomycelates, suborder Corynebacterineae. Lg strain was identified as Gordonia polyisoprenivorans and Lc strain did not correspond to a known description and therefore a more detailed study is under preparation. Considering all ecological aspects and the metabolic potential associated with the microorganisms of the environment studied, as well as the capacity to produce pigment and EPS, and the presence of G. polyisoprenivorans, a rubber degrader bacterium, the potential of the groundwater analyzed is evident as a source of microorganisms to be utilized in studies related to environmental remediation.

  1. Addressing Flooding and SuDS when Improving Drainage and Sewerage Systems—A Comparative Study of Selected Scandinavian Cities

    Directory of Open Access Journals (Sweden)

    Geir Torgersen

    2014-04-01

    Full Text Available Pluvial flooding already challenges the capacity of drainage and sewerage system in urban areas in Scandinavia. For system owners this requires a stricter prioritization when improving the systems. Experts seem to agree that a regime shift from improving old combined sewers by piped solutions to more sustainable drainage systems (SuDS, must take place. In this paper results from an investigation amongst the largest cities in Norway, Denmark and Sweden concerning drivers and preferred methods for improving the old system are presented. The results indicate that Norway ranks flood prevention lower than the other Scandinavian countries. During the last decades, Norwegian authorities have had a strong focus on pollution from wastewater treatment plants (WWTP. The attention to drainage and sewerage system regarding flooding, water leaks, infiltration or pollution has been neglected. Renewal or rate of investment in relation to existing drainage and sewerage system is easy to register, and provides a measure of the activity. In order to optimize flood prevention, and may be promoting the use of SuDS, the cities should be required to measure the efficiency, either by monitoring or modeling the impact of stormwater to the system. Lack of such requirements from Norwegian authorities seem to be a plausible explanation to why Norwegian cities are less focused on flood prevention compared to Swedish and Danish cities.

  2. [CAT-guided percutaneous drainage of abscesses].

    Science.gov (United States)

    Aguilera Manrique, F; Fernández Miranda, E; García Cáceres, E; Franciso Moriana Maldonado, J; Granero Molina, J; Aguilera Manrique, G

    2001-09-01

    Drainage of percutaneous abscesses guided by Computerized Axial Tomography (CAT) is a technique being employed more frequently all the time by Radiodiagnostic Services. Correctly put into practice by trained professionals, this procedure can prevent patients having to undergo another series of treatments which bear greater risks, to have a longer hospital stay, or even, depending on the case, to have to undergo an operation. Nurses in a radiological unit have an overwhelming role in every step of a percutaneous abscess drainage, a role which can not be carried out by any other personnel. To achieve being up to date in this technique and to perform our function as nurses in the use of this technique are the main objectives of this review.

  3. Percutaneous drainage of 100 subphrenic abscesses

    International Nuclear Information System (INIS)

    Casola, G.; Sonnenberg, E. van; D'Agostino, H.; Kothari, R.; May, S.; Taggart, S.

    1990-01-01

    PURPOSE: Percutaneous drainage of subphrenic abscesses is technically more difficult because lung and pleura may be transgressed during catheter insertion. The purpose of this paper is to determine the incidence of thoracic complications secondary to subphrenic abscess drainage and to determine factors that may alter this. The authors' series consists of 100 subphrenic abscesses that were drained percutaneously. Patients range in age from 14 to 75 years. Abscesses were secondary to surgery (splenectomy, pancreatectomy, partial hepatectomy, gastrectomy), pancreatitis, and trauma. Catheters ranged in size from 8 to 14 F and were inserted via trocar or Seldinger technique. Thoracic complications of pneumothorax or empyema were determined from follow-up chest radiographs or CT scans

  4. SOIL COVER IN TUTOVA DRAINAGE BASIN

    Directory of Open Access Journals (Sweden)

    I. C. Stanga

    2010-10-01

    Full Text Available This article covers a monographic presentation of the soils from the Tutova drainage basin. The analysis of the pedogeographic assemblage was performed based on the soil surveys of the territories corresponding to Tutova’s drainage basin, and completed with field research. The taxonomic classification was done in accordance with the Romanian System of Soil Taxonomy (2003 and the soil map was created at a 1:25.000 scale. The zonal soils dominate the region; the Chernisols are on the first rank with a share of 39.95%, followed by Luvisols with a percent of 27.62%. Among the soils with an azonal and intrazonal character, the entic soils are dominant (21.90%, followed by Anthrosols (8.89% and by Hydrisols (1.64%.

  5. Range of drainage effect of surface mines

    Energy Technology Data Exchange (ETDEWEB)

    Sozanski, J.

    1978-03-01

    This paper discusses methods of calculating the range of effects of water drainage from surface coal mines and other surface mines. It is suggested that methods based on test pumping (water drainage) are time consuming, and the results can be distorted by atmospheric factors such as rain fall or dry period. So-called empirical formulae produce results which are often incorrect. The size of a cone shaped depression calculated on the basis of empirical formulae can be ten times smaller than the size of the real depression. It is suggested that using a formula based on the Dupuit formula is superior to other methods of depression calculation. According to the derived formulae the radius of the depresion cone is a function of parameters of the water bearing horizons, size of surface mine working and of water depression. The proposed formula also takes into account the influence of atmospheric factors (water influx caused by precipitation, etc.). (1 ref.) (In Polish)

  6. Air pollution

    International Nuclear Information System (INIS)

    Feugier, A.

    1996-01-01

    The air pollution results from the combustion of petroleum products, natural gas, coal, wastes and transports. Some compounds are considered as particularly pollutants: the carbon monoxide, the nitrogen oxides, the tropospheric ozone and the sulfur dioxides. Their environmental and biological effects are described. The present political guide lines concerns the combustion plants, the ozone, the wastes incineration and the vehicles emissions. The aim is at some future date to control the air quality, to reduce the volatile organic compounds emissions and to limit the sulfur rate of some petroleum products. (O.L.)

  7. ENVIRONMENTAL POLLUTION

    OpenAIRE

    Reyna Ramos, julio

    2014-01-01

    The article shows the complexity of the problem of environmental pollution and what can be the possible solutions to the problem. Also, how the Industrial Engineering can contribute to the prevention and control of pollution. El artículo muestra la complejidad del problema de la contaminación ambiental y cuáles pueden ser las propuestas de solución al problema. Así mismo, cómo la Ingeniería Industrial puede contribuir a la prevención y control de la contaminación.

  8. Proceedings of the international land reclamation and mine drainage conference and third international conference on the abatement of acidic drainage. Volume 2: Mine drainage -- SP 06B-94

    International Nuclear Information System (INIS)

    Anon.

    1994-01-01

    Volume 2 of these proceedings is divided into six sessions: Mine drainage--Case studies (5 papers); Control of mine drainage--General (6); Control of mine drainage--Dry covers (6); Mine hydrology (6); a Poster session of miscellaneous papers (24); and a section of 59 abstracts. 78 papers dealing with or applicable to coal or uranium mining have been processed separately for inclusion on the data base

  9. Factors influencing pleural drainage in parapneumonic effusions.

    Science.gov (United States)

    Porcel, J M; Valencia, H; Bielsa, S

    2016-10-01

    The identification of parapneumonic effusions (PPE) requiring pleural drainage is challenging. We aimed to determine the diagnostic accuracy of radiological and pleural fluid findings in discriminating between PPE that need drainage (complicated PPE (CPPE)) and those that could be resolved with antibiotics only (uncomplicated PPE (UPPE)). A retrospective review of 641 consecutive PPE, of which 393 were categorized as CPPE and 248 as UPPE. Demographics, radiological (size and laterality on a chest radiograph) and pleural fluid parameters (pus, bacterial cultures, biochemistries) were compared among groups. Logistic regression was performed to determine variables useful for predicting chest drainage, and receiver-operating characteristic curves assisted in the selection of the best cutoff values. According to the likelihood ratios (LR), findings increasing the probability of chest tube usage the most were: effusions occupying ≥1/2 of the hemithorax (LR 13.5), pleural fluid pH ≤7.15 (LR 6.2), pleural fluid glucose ≤40mg/dL (LR 5.6), pus (LR 4.8), positive pleural fluid cultures (LR 3.6), and pleural fluid lactate dehydrogenase >2000U/L (LR 3.4). In the logistic regression analysis only the first two were selected as significant predictors of CPPE. In non-purulent effusions, the effusion's size and pleural fluid pH retained their discriminatory properties, in addition to a pleural fluid C-reactive protein (CRP) level >100mg/L. Large radiological effusions and a pleural fluid pH ≤7.15 were the best predictors for chest drainage in patients with PPE. In the subgroup of patients with non-purulent effusions, pleural fluid CRP also contributed to CPPE identification. Copyright © 2016 Elsevier España, S.L.U. and Sociedad Española de Medicina Interna (SEMI). All rights reserved.

  10. Integrated urban drainage, status and perspectives

    DEFF Research Database (Denmark)

    Harremoës, Poul

    2002-01-01

    This paper summarises the status of urban storm drainage as an integrated professional discipline, including the management-policy interface, by which the goals of society are implemented. The paper assesses the development of the discipline since the INTERURBA conference in 1992 and includes asp......-stream concrete solutions. The challenge is to combine the inherited approaches with the new approaches by flexibility and adaptability....

  11. Is routine drainage necessary after pancreaticoduodenectomy?

    Science.gov (United States)

    Wang, Qiang; Jiang, Yong-Jian; Li, Ji; Yang, Feng; Di, Yang; Yao, Lie; Jin, Chen; Fu, De-Liang

    2014-01-01

    With the development of imaging technology and surgical techniques, pancreatic resections to treat pancreatic tumors, ampulla tumors, and other pancreatic diseases have increased. Pancreaticoduodenectomy, one type of pancreatic resection, is a complex surgery with the loss of pancreatic integrity and various anastomoses. Complications after pancreaticoduodenectomy such as pancreatic fistulas and anastomosis leakage are common and significantly associated with patient outcomes. Pancreatic fistula is one of the most important postoperative complications; this condition can cause intraperitoneal hemorrhage, septic shock, or even death. An effective way has not yet been found to avoid the occurrence of pancreatic fistula. In most medical centers, the frequency of pancreatic fistula has remained between 9% and 13%. The early detection and routine drainage of anastomotic fistulas, pancreatic fistulas, bleeding, or other intra-abdominal fluid collections after pancreatic resections are considered as important and effective ways to reduce postoperative complications and the mortality rate. However, many recent studies have argued that routine drainage after abdominal operations, including pancreaticoduodenectomies, does not affect the incidence of postoperative complications. Although inserting drains after pancreatic resections continues to be a routine procedure, its necessity remains controversial. This article reviews studies of the advantages and disadvantages of routine drainage after pancreaticoduodenectomy and discusses the necessity of this procedure. PMID:25009383

  12. Branching pattern in natural drainage network

    Science.gov (United States)

    Hooshyar, M.; Singh, A.; Wang, D.

    2017-12-01

    The formation and growth of river channels and their network evolution are governed by the erosional and depositional processes operating on the landscape due to movement of water. The branching structure of drainage network is an important feature related to the network topology and contain valuable information about the forming mechanisms of the landscape. We studied the branching patterns in natural drainage networks, extracted from 1 m Digital Elevation Models (DEMs) of 120 catchments with minimal human impacts across the United States. We showed that the junction angles have two distinct modes an the observed modes are physically explained as the optimal angles that result in minimum energy dissipation and are linked to the exponent characterizing slope-area curve. Our findings suggest that the flow regimes, debris-flow dominated or fluvial, have distinct characteristic angles which are functions of the scaling exponent of the slope-area curve. These findings enable us to understand the geomorphological signature of hydrological processes on drainage networks and develop more refined landscape evolution models.

  13. Drainage and Stratification Kinetics of Foam Films

    Science.gov (United States)

    Zhang, Yiran; Sharma, Vivek

    2014-03-01

    Baking bread, brewing cappuccino, pouring beer, washing dishes, shaving, shampooing, whipping eggs and blowing bubbles all involve creation of aqueous foam films. Foam lifetime, drainage kinetics and stability are strongly influenced by surfactant type (ionic vs non-ionic), and added proteins, particles or polymers modify typical responses. The rate at which fluid drains out from a foam film, i.e. drainage kinetics, is determined in the last stages primarily by molecular interactions and capillarity. Interestingly, for certain low molecular weight surfactants, colloids and polyelectrolyte-surfactant mixtures, a layered ordering of molecules, micelles or particles inside the foam films leads to a stepwise thinning phenomena called stratification. Though stratification is observed in many confined systems including foam films containing particles or polyelectrolytes, films containing globular proteins seem not to show this behavior. Using a Scheludko-type cell, we experimentally study the drainage and stratification kinetics of horizontal foam films formed by protein-surfactant mixtures, and carefully determine how the presence of proteins influences the hydrodynamics and thermodynamics of foam films.

  14. Percutaneous abscess drainage in Crohn's disease

    International Nuclear Information System (INIS)

    Strotzer, M.; Manke, C.; Feuerbach, S.; Lock, G.; Bregenzer, N.; Schoelmerich, J.

    1998-01-01

    Purpose: To evaluate the success of percutaneous, CT-guided abscess drainage (PAD) in patients with Crohn's disease. Methods: Within the last 5 years 8 patients with Crohn's disease were treated by PAD for intra-abdominal abscesses. A fistula was determined to be the cause in 4 patients. The abscesses arose spontaneously in 7 patients while one patient had a postperative abscess. We used single lumen 10F- and double lumen 12F- and 14F-catheters for drainage (duration of drainage 8-20 days). Results: In all cases the abscess was successfully drained by PAD. However, an operation-free interval of at least three months was achieved in only two patients. A healing of the fistula was not attained in any of the 4 patients with a proven fistula. No enterocutaneous fistulas arose within the course of PAD. Conclusions: PAD is also useful for patients with Crohn's disease since it improves the starting situation for the necessary operative interventions. In most cases (especially with enterogenic fistulas), however, a long-lasting therapeutic result cannot be expected. (orig.) [de

  15. Modeling of subglacial hydrological development following rapid supraglacial lake drainage

    Science.gov (United States)

    Dow, C F; Kulessa, B; Rutt, I C; Tsai, V C; Pimentel, S; Doyle, S H; van As, D; Lindbäck, K; Pettersson, R; Jones, G A; Hubbard, A

    2015-01-01

    The rapid drainage of supraglacial lakes injects substantial volumes of water to the bed of the Greenland ice sheet over short timescales. The effect of these water pulses on the development of basal hydrological systems is largely unknown. To address this, we develop a lake drainage model incorporating both (1) a subglacial radial flux element driven by elastic hydraulic jacking and (2) downstream drainage through a linked channelized and distributed system. Here we present the model and examine whether substantial, efficient subglacial channels can form during or following lake drainage events and their effect on the water pressure in the surrounding distributed system. We force the model with field data from a lake drainage site, 70 km from the terminus of Russell Glacier in West Greenland. The model outputs suggest that efficient subglacial channels do not readily form in the vicinity of the lake during rapid drainage and instead water is evacuated primarily by a transient turbulent sheet and the distributed system. Following lake drainage, channels grow but are not large enough to reduce the water pressure in the surrounding distributed system, unless preexisting channels are present throughout the domain. Our results have implications for the analysis of subglacial hydrological systems in regions where rapid lake drainage provides the primary mechanism for surface-to-bed connections. Key Points Model for subglacial hydrological analysis of rapid lake drainage events Limited subglacial channel growth during and following rapid lake drainage Persistence of distributed drainage in inland areas where channel growth is limited PMID:26640746

  16. Modeling of subglacial hydrological development following rapid supraglacial lake drainage.

    Science.gov (United States)

    Dow, C F; Kulessa, B; Rutt, I C; Tsai, V C; Pimentel, S; Doyle, S H; van As, D; Lindbäck, K; Pettersson, R; Jones, G A; Hubbard, A

    2015-06-01

    The rapid drainage of supraglacial lakes injects substantial volumes of water to the bed of the Greenland ice sheet over short timescales. The effect of these water pulses on the development of basal hydrological systems is largely unknown. To address this, we develop a lake drainage model incorporating both (1) a subglacial radial flux element driven by elastic hydraulic jacking and (2) downstream drainage through a linked channelized and distributed system. Here we present the model and examine whether substantial, efficient subglacial channels can form during or following lake drainage events and their effect on the water pressure in the surrounding distributed system. We force the model with field data from a lake drainage site, 70 km from the terminus of Russell Glacier in West Greenland. The model outputs suggest that efficient subglacial channels do not readily form in the vicinity of the lake during rapid drainage and instead water is evacuated primarily by a transient turbulent sheet and the distributed system. Following lake drainage, channels grow but are not large enough to reduce the water pressure in the surrounding distributed system, unless preexisting channels are present throughout the domain. Our results have implications for the analysis of subglacial hydrological systems in regions where rapid lake drainage provides the primary mechanism for surface-to-bed connections. Model for subglacial hydrological analysis of rapid lake drainage eventsLimited subglacial channel growth during and following rapid lake drainagePersistence of distributed drainage in inland areas where channel growth is limited.

  17. Ultrasound-guided drainage of deep pelvic abscesses

    DEFF Research Database (Denmark)

    Lorentzen, Torben; Nolsøe, Christian; Skjoldbye, Bjørn

    2011-01-01

    The aim of this study was to demonstrate and evaluate the ultrasound-guided drainage of deep pelvic abscesses in which transabdominal percutaneous access could not be performed because of overlying structures. A retrospective analysis of 32 consecutive patients with 33 deep pelvic abscesses...... (median diameter 7 cm), 19 were treated with catheter drainage and 18 of these cases resulted in favorable clinical outcomes. Of the smaller abscesses (median diameter 4 cm), 14 were treated with needle drainage. In two of these cases, follow-up US showed that a repeat puncture and drainage was necessary....... All needle drainages resulted in favorable clinical outcomes. Sixteen of the 29 transrectal or transvaginal drainage procedures were performed without any anesthesia (10 were performed with a needle and six were performed with a catheter). Apart from minor discomfort during the drainage procedure...

  18. Ground water pollution through air pollutants

    International Nuclear Information System (INIS)

    Cichorowski, G.; Michel, B.; Versteegen, D.; Wettmann, R.

    1989-01-01

    The aim of the investigation is to determine the significance of air pollutants for ground water quality and ground water use. The report summarizes present knowledge and assesses statements with a view to potential ground water pollution from the air. In this context pollution paths, the spreading behaviour of pollutants, and 'cross points' with burden potentials from other pollutant sources are presented. (orig.) [de

  19. Water Pollution

    Science.gov (United States)

    We all need clean water. People need it to grow crops and to operate factories, and for drinking and recreation. Fish and wildlife depend on ... and phosphorus make algae grow and can turn water green. Bacteria, often from sewage spills, can pollute ...

  20. Nuclear pollution

    International Nuclear Information System (INIS)

    Ramade, Francois

    1979-01-01

    In this chapter devoted to nuclear pollution the following topics were studied: fundamentals of radiobiology (ecological importance of the various radioisotopes, biological effects of ionizing radiations); ecological effects of radioactive fallout (contamination of atmosphere, terrestrial ecosystems, oceans). The electronuclear industry and its environmental impact. PWR type reactors, fuel reprocessing plants, contamination of trophic chains by radionuclides released in the environment from nuclear installations [fr

  1. Water quality-based real time control of integrated urban drainage: a preliminary study from Copenhagen, Denmark

    OpenAIRE

    Vezzaro, Luca; Lund Christensen, Margit; Thirsing, Carsten; Grum, Morten; Mikkelsen, Peter Steen

    2013-01-01

    Global Real Time Control (RTC) of urban drainage systems is increasingly seen as cost-effective solution for responding to increasing performance demands. This study investigated the potential for including water-quality based RTC into the global control strategy which is under implementation in the Lynetten catchment (Copenhagen, Denmark). Two different strategies were simulated, considering: (i) water quality at the wastewater treatment plant (WWTP) inlet and (ii) pollution discharge to the...

  2. Regulations for the peat production water pollution control

    International Nuclear Information System (INIS)

    Savolainen, M.; Heikkinen, K.; Ihme, R.

    1996-01-01

    The regulations for peat production water pollution control include the latest information on anti-pollution constructions applicable to peat production including field ditches, sedimentation basins, overland flow areas, forest soil saturation, evaporation basins, chemicalization, detention of runoff and artificial flood plains. Information on subsurface drainage in peat mining is also given. The regulations deal with environmental viewpoints, planning of water protection and information on how to build, use and maintain anti-pollution constructions. Special attention is given to the soil conditions, because they play an important role in the building of different constructions. (orig.) (48 refs.)

  3. Regulations for the peat production water pollution control; Turvetuotannon vesiensuojeluohjeisto

    Energy Technology Data Exchange (ETDEWEB)

    Savolainen, M.; Heikkinen, K.; Ihme, R. [ed.] [VTT Communities and Infrastructure, Espoo (Finland)

    1996-12-31

    The regulations for peat production water pollution control include the latest information on anti-pollution constructions applicable to peat production including field ditches, sedimentation basins, overland flow areas, forest soil saturation, evaporation basins, chemicalization, detention of runoff and artificial flood plains. Information on subsurface drainage in peat mining is also given. The regulations deal with environmental viewpoints, planning of water protection and information on how to build, use and maintain anti-pollution constructions. Special attention is given to the soil conditions, because they play an important role in the building of different constructions. (orig.) (48 refs.)

  4. Treatment Solutions for Rainwater Contaminated with Various Pollutants

    Directory of Open Access Journals (Sweden)

    Adriana Tokar

    2015-07-01

    Full Text Available This study presents aspects on the environmental pollution with contaminants difficult to manage from sources such as car parking, roads and roofs in crowded areas that have deficient wastewater harvesting urban networks. The contaminants washed by the rainwater that are not collected and treated can reach directly into the natural environment. Thus, rainwater which falls on rough surfaces, especially in car parking and roads without drainage channels carries out various pollutants directly into the soil and water. In order to control environmental pollution there are presented solutions for contaminated rainwater depollution.

  5. Comparison between autologous blood transfusion drainage and closed-suction drainage/no drainage in total knee arthroplasty: a meta-analysis.

    Science.gov (United States)

    Hong, Kun-Hao; Pan, Jian-Ke; Yang, Wei-Yi; Luo, Ming-Hui; Xu, Shu-Chai; Liu, Jun

    2016-08-01

    Autologous blood transfusion (ABT) drainage system is a new unwashed salvaged blood retransfusion system for total knee replacement (TKA). However, whether to use ABT drainage, closed-suction (CS) drainage or no drainage in TKA surgery remains controversial. This is the first meta-analysis to assess the clinical efficiency, safety and potential advantages regarding the use of ABT drains compared with closed-suction/no drainage. PubMed, Embase, and the Cochrane Library were comprehensively searched in March 2015. Fifteen randomized controlled trials (RCTs) were identified and pooled for statistical analysis. The primary outcome evaluated was homologous blood transfusion rate. The secondary outcomes were post-operative haemoglobin on days 3-5, length of hospital stay and wound infections after TKA surgery. The pooled data included 1,721 patients and showed that patients in the ABT drainage group might benefit from lower blood transfusion rates (16.59 % and 37.47 %, OR: 0.28 [0.14, 0.55]; 13.05 % and 16.91 %, OR: 0.73 [0.47,1.13], respectively). Autologous blood transfusion drainage and closed-suction drainage/no drainage have similar clinical efficacy and safety with regard to post-operative haemoglobin on days 3-5, length of hospital stay and wound infections. Autologous blood transfusion drainage offers a safe and efficient alternative to CS/no drainage with a lower blood transfusion rate. Future large-volume high-quality RCTs with extensive follow-up will affirm and update this system review.

  6. Advances in drainage: Selected works from the Tenth International Drainage Symposium

    Science.gov (United States)

    Strock, Jeffrey S.; Hay, Christopher; Helmers, Matthew; Nelson, Kelly A.; Sands, Gary R.; Skaggs, R. Wayne; Douglas-Mankin, Kyle R.

    2018-01-01

    This article introduces a special collection of fourteen articles accepted from among the 140 technical presentations, posters, and meeting papers presented at the 10th International ASABE Drainage Symposium. The symposium continued in the tradition of previous symposia that began in 1965 as a forum for presenting and assessing the progress of drainage research and implementation throughout the world. The articles in this collection address a wide range of topics grouped into five broad categories: (1) crop response, (2) design and management, (3) hydrology and scale, (4) modeling, and (5) water quality. The collection provides valuable information for scientists, engineers, planners, and others working on crop production, water quality, and water quantity issues affected by agricultural drainage. The collection also provides perspectives on the challenges of increasing agricultural production in a changing climate, with ever-greater attention to water quality and quantity concerns that will require integrated technical, economic, and social solutions.

  7. Relating land use patterns to stream nutrient levels in red soil agricultural catchments in subtropical central China.

    Science.gov (United States)

    Wang, Yi; Li, Yong; Liu, Xinliang; Liu, Feng; Li, Yuyuan; Song, Lifang; Li, Hang; Ma, Qiumei; Wu, Jinshui

    2014-09-01

    Land use has obvious influence on surface water quality; thus, it is important to understand the effects of land use patterns on surface water quality. This study explored the relationships between land use patterns and stream nutrient levels, including ammonium-N (NH4 (+)-N), nitrate-N (NO3 (-)-N), total N (TN), dissolved P (DP), and total P (TP) concentrations, in one forest and 12 agricultural catchments in subtropical central China. The results indicated that the TN concentrations ranged between 0.90 and 6.50 mg L(-1) and the TP concentrations ranged between 0.08 and 0.53 mg L(-1), showing that moderate nutrient pollution occurred in the catchments. The proportional areal coverages of forests, paddy fields, tea fields, residential areas, and water had distinct effects on stream nutrient levels. Except for the forest, all studied land use types had a potential to increase stream nutrient levels in the catchments. The land use pattern indices at the landscape level were significantly correlated to N nutrients but rarely correlated to P nutrients in stream water, whereas the influence of the land use pattern indices at the class level on stream water quality differentiated among the land use types and nutrient species. Multiple regression analysis suggested that land use pattern indices at the class level, including patch density (PD), largest patch index (LPI), mean shape index (SHMN), and mean Euclidian nearest neighbor distance (ENNMN), played an intrinsic role in influencing stream nutrient quality, and these four indices explained 35.08 % of the variability of stream nutrient levels in the catchments (pstream nutrient pollution in subtropical central China.

  8. Removal of organic and inorganic pollutants from aqueous solutions by organically modified clayey sediments

    OpenAIRE

    Mubarak, Dalia Mohamed Fahmy

    2012-01-01

    Re-use of agricultural drainage water and industrial wastewater is one of the adopted strategies in different countries to close the gap between water resources and water demands. Drainage and industrial wastewater contain varieties of toxic pollutants that can potentially cause hazard on humans and environment. Although adsorption techniques are considered one of the proper methods for the wastewater treatments, economic aspect is a crucial factor for the broad application of such technique....

  9. Hazardous Air Pollutants

    Science.gov (United States)

    ... Protection Agency Search Search Contact Us Share Hazardous Air Pollutants Hazardous air pollutants are those known to ... of industrial facilities in two phases . About Hazardous Air Pollutants What are Hazardous Air Pollutants? Health and ...

  10. Concepts of Urban Drainage and Flood Protection

    DEFF Research Database (Denmark)

    Harremoës, Poul

    1990-01-01

    to calculate surcharging and flooding, rather than just relating to pipe capacity performance criteria; the capability of calculating long series of rain record in order to derive proper statistics on the pollutional load on the environment; and finally the capability of dynamically controlling the system...... in real time in order to decrease the pollutional load by optimization of the usage of storage at rains smaller than the design rain, without increasing the risk of floods....

  11. Spectral Pollution

    OpenAIRE

    Davies, E B; Plum, M

    2003-01-01

    We discuss the problems arising when computing eigenvalues of self-adjoint operators which lie in a gap between two parts of the essential spectrum. Spectral pollution, i.e. the apparent existence of eigenvalues in numerical computations, when no such eigenvalues actually exist, is commonplace in problems arising in applied mathematics. We describe a geometrically inspired method which avoids this difficulty, and show that it yields the same results as an algorithm of Zimmermann and Mertins.

  12. Adaptive Strategies of Bacillus thuringiensis Isolated from Acid Mine Drainage Site in Sabah, Malaysia.

    Science.gov (United States)

    Yik, Low Yi; Chin, Grace Joy Wei Lie; Budiman, Cahyo; Joseph, Collin Glenn; Musta, Baba; Rodrigues, Kenneth Francis

    2018-06-01

    The adaptive process in bacteria is driven by specific genetic elements which regulate phenotypic characteristics such as tolerance to high metal ion concentrations and the secretion of protective biofilms. Extreme environments such as those associated with heavy metal pollution and extremes of acidity offer opportunities to study the adaptive mechanisms of microorganisms. This study focused on the genome analysis of Bacillus thuringiensis (Bt MCMY1), a gram positive rod shaped bacterium isolated from an acid mine drainage site in Sabah, Malaysia by using a combination of Single Molecule Real Time DNA Sequencing, Scanning Electron Microscopy (SEM) and Fourier Transform Infrared Spectroscopy (FTIR). The genome size of Bt MCMY1 was determined to be 5,458,152 bases which was encoded on a single chromosome. Analysis of the genome revealed genes associated with resistance to Copper, Mercury, Arsenic, Cobalt, Zinc, Cadmium and Aluminum. Evidence from SEM and FTIR indicated that the bacterial colonies form distinct films which bear the signature of polyhydroxyalkanoates (PHA) and this finding was supported by the genome data indicating the presence of a genetic pathway associated with the biosynthesis of PHAs. This is the first report of a Bacillus sp. isolated from an acid mine drainage site in Sabah, Malaysia and the genome sequence will provide insights into the manner in which B. thuringiensis adapts to acid mine drainage.

  13. Regional Assessment of Human Fecal Contamination in Southern California Coastal Drainages

    Science.gov (United States)

    Cao, Yiping; Raith, Meredith R.; Smith, Paul D.; Griffith, John F.; Weisberg, Stephen B.; Schriewer, Alexander; Sheldon, Andrew; Crompton, Chris; Gregory, Jason; Guzman, Joe; Othman, Laila; Manasjan, Mayela; Choi, Samuel; Rapoport, Shana; Steele, Syreeta; Nguyen, Tommy; Yu, Xueyuan

    2017-01-01

    Host-associated genetic markers that allow for fecal source identification have been used extensively as a diagnostic tool to determine fecal sources within watersheds, but have not been used in routine monitoring to prioritize remediation actions among watersheds. Here, we present a regional assessment of human marker prevalence among drainages that discharge to the U.S. southern California coast. Approximately 50 samples were analyzed for the HF183 human marker from each of 22 southern California coastal drainages under summer dry weather conditions, and another 50 samples were targeted from each of 23 drainages during wet weather. The HF183 marker was ubiquitous, detected in all but two sites in dry weather and at all sites during wet weather. However, there was considerable difference in the extent of human fecal contamination among sites. Similar site ranking was produced regardless of whether the assessment was based on frequency of HF183 detection or site average HF183 concentration. However, site ranking differed greatly between dry and wet weather. Site ranking also differed greatly when based on enterococci, which do not distinguish between pollution sources, vs. HF183, which distinguishes higher risk human fecal sources from other sources, indicating the additional value of the human-associated marker as a routine monitoring tool. PMID:28777324

  14. Pitfalls in Cutaneous Melanoma Lymphatic Drainage.

    Science.gov (United States)

    Voinea, Silviu; Sandru, Angela; Gherghe, Mirela

    2016-01-01

    Sentinel node (SN) biopsy has become standard in staging of cutaneous melanoma. As skin lymphatic drainage is complex, preoperative empirical assessment of SN localization is virtually impossible. Therefore in order to identify all regional lymphatic basins corresponding to a specific primary tumor is mandatory to carry out preoperative lymphoscintigraphy. In this paper we present a clinical case that highlights the importance of identifying, biopsy and histological analysis of all SN in order to achieve a correct staging of the patient, followed by appropriate treatment according to the real clinical stage of the disease. Celsius.

  15. Button self-retaining drainage catheter

    International Nuclear Information System (INIS)

    Caridi, James G.; Hawkins, Irvin F.; Akins, E. William; Young, Ronald S.

    1997-01-01

    To help improve patient acceptance of long-term internal/external catheter access to the biliary tract in those with benign biliary obstruction, a simple design allows the catheter end to remain flush with the skin. It consists of a clothes button affixed to the drainage catheter with a wood screw after the catheter has been cut off at the skin exit. This button/screw device has been used successfully in 22 patients over the last 10 years; catheter exchanges were easily accomplished

  16. Percutaneous biliary drainage in patients with cholangiocarcinoma

    International Nuclear Information System (INIS)

    Mehta, A.C.; Gobel, R.J.; Rose, S.C.; Hayes, J.K.; Miller, F.J.

    1990-01-01

    This paper determines whether radiation therapy (RT) is a risk factor for infectious complications (particularly hepatic abscess formation) related to percutaneous biliary drainage (PBD). The authors retrospectively reviewed the charts of 98 consecutive patients who had undergone PBD for obstruction. In 34 patients with benign obstruction, three infectious complications occurred, none of which were hepatic abscess or fatal sepsis. In 39 patients who had malignant obstruction but did not have cholangiocarcinoma, 13 infectious complications occurred, including two hepatic abscesses and three cases of fatal sepsis. Of the 25 patients with cholangiocarcinoma, 15 underwent RT; in these 15 patients, 14 infectious complications occurred, including six hepatic abscesses and two cases of fatal sepsis

  17. Water Pollution. Project COMPSEP.

    Science.gov (United States)

    Lantz, H. B., Jr.

    This is an introductory program on water pollution. Examined are the cause and effect relationships of water pollution, sources of water pollution, and possible alternatives to effect solutions from our water pollution problems. Included is background information on water pollution, a glossary of pollution terminology, a script for a slide script…

  18. Percutaneous drainage of diverticular abscess: Adjunct to resection

    International Nuclear Information System (INIS)

    Mueller, P.R.; Saini, S.; Butch, R.J.; Simeone, J.F.; Rodkey, G.V.; Bousquet, J.C.; Ottinger, L.W.; Wittenberg, J.; Ferrucci, J.T. Jr.

    1986-01-01

    Traditional surgical management of acute diverticulitis with abscess may require a one-, two-, or three-stage procedure. Because of recent interest in CT diagnosis of diverticulitis, and novel access routes for interventional drainage of deep pelvic abscesses, the authors investigated the potential for converting complex two- and three-stage surgical procedures to simpler, safer one-stage colon resections by percutaneous drainage of the associated abscess. Of 23 patients with acute perforated diverticulitis who were referred for catheter drainage under radiologic guidance, successful catheter drainage and subsequent single-stage colon resection were carried out in 15. In three patients catheter drainage was unsuccessful and a multistage procedure was required. In three patients only percutaneous drainage was performed and operative intervention was omitted entirely

  19. Characteristics of Riverine DIN Export in Subtropical High-standing Island, Taiwan

    Science.gov (United States)

    Huang, J. C.; Kao, S. J.; Lee, T. Y.; Lin, T. C.

    2016-12-01

    Increases in nitrogen (N) availability and mobility resulting from anthropogenic activities has substantially altered nitrogen cycle both locally and globally. Taiwan characterized by the subtropical montane landscape with abundant rainfall, downwind to the most rapidly industrializing east coast of China can be a demonstration site for extreme high N input and riverine DIN (dissolved inorganic N) export. We used 49 watersheds with similar climatic and landscape settings, but classified into low-, moderate-, and highly-disturbed categories based on population density to illustrate their differences in nitrogen inputs through atmospheric N deposition, synthetic fertilizer and human emission and DIN export ratios. Our results showed that the island-wide average riverine DIN export is 3800 kg-N/km2yr, approximately 18-fold higher than the global average mostly due to the large input of synthetic fertilizer. The average riverine DIN export ratio is 0.30-0.51, which is much higher than the average of 0.20-0.25 of large rivers around the world indicating excessive N input relative to ecosystem demand or retention capacity. The low-disturbed watersheds despite of high input only export 0.06-0.18 of the input and well buffered to changes in input quantity suggesting high efficiency of nitrogen usage or high N retention capacity of the less disturbed watersheds. The moderate-disturbed watersheds show a linear increase of output with increases in total N inputs and a mean DIN export ratio of 0.20 to 0.31. The main differences in land use between low and moderately disturbed watershed are the relative proportions of agricultural land and forests, not the built-up lands. The export ratio of the highly-disturbed watersheds is 0.42-0.53, which is very high and suggests that much of the N input is transported downstream. The increases in riverine DIN export ratio along with the gradient of human disturbance in subtropical Taiwan shows a gradient in excess N saturation. Our

  20. Arterial Pulsations cannot Drive Intramural Periarterial Drainage: Significance for Aβ Drainage

    Directory of Open Access Journals (Sweden)

    Alexandra K. Diem

    2017-08-01

    Full Text Available Alzheimer's Disease (AD is the most common form of dementia and to date there is no cure or efficient prophylaxis. The cognitive decline correlates with the accumulation of amyloid-β (Aβ in the walls of capillaries and arteries. Our group has demonstrated that interstitial fluid and Aβ are eliminated from the brain along the basement membranes of capillaries and arteries, the intramural periarterial drainage (IPAD pathway. With advancing age and arteriosclerosis, the stiffness of arterial walls, this pathway fails in its function and Aβ accumulates in the walls of arteries. In this study we tested the hypothesis that arterial pulsations drive IPAD and that a valve mechanism ensures the net drainage in a direction opposite to that of the blood flow. This hypothesis was tested using a mathematical model of the drainage mechanism. We demonstrate firstly that arterial pulsations are not strong enough to produce drainage velocities comparable to experimental observations. Secondly, we demonstrate that a valve mechanism such as directional permeability of the IPAD pathway is necessary to achieve a net reverse flow. The mathematical simulation results are confirmed by assessing the pattern of IPAD in mice using pulse modulators, showing no significant alteration of IPAD. Our results indicate that forces other than the cardiac pulsations are responsible for efficient IPAD.

  1. Turbulent vertical diffusivity in the sub-tropical stratosphere

    Directory of Open Access Journals (Sweden)

    I. Pisso

    2008-02-01

    Full Text Available Vertical (cross-isentropic mixing is produced by small-scale turbulent processes which are still poorly understood and paramaterized in numerical models. In this work we provide estimates of local equivalent diffusion in the lower stratosphere by comparing balloon borne high-resolution measurements of chemical tracers with reconstructed mixing ratio from large ensembles of random Lagrangian backward trajectories using European Centre for Medium-range Weather Forecasts analysed winds and a chemistry-transport model (REPROBUS. We focus on a case study in subtropical latitudes using data from HIBISCUS campaign. An upper bound on the vertical diffusivity is found in this case study to be of the order of 0.5 m2 s−1 in the subtropical region, which is larger than the estimates at higher latitudes. The relation between diffusion and dispersion is studied by estimating Lyapunov exponents and studying their variation according to the presence of active dynamical structures.

  2. Potential role of resurfacing Subtropical Underwater in ENSO evolution

    Science.gov (United States)

    Qu, T.; Chi, J.

    2017-12-01

    Results from a model of the Estimating the Circulation and Climate of the Ocean (ECCO) have shown that the resurfacing of high salinity Subtropical Underwater contributes to the sea surface salinity variability in the equatorial Pacific. On interannual time scale, this contribution can account for as much as 25% of the surface freshwater flux anomalies and is believed to play a role in ENSO evolution. Having these results in mind, this study investigates the surface salinity budget and its primary controls in the equatorial Pacific using ECCO output for the period 1993-2016. Particular attention is paid to 2014/2015 and 2015/2016. Preliminary analyses of the model results suggest that enhanced subsurface processes and in particular enhanced entrainment of Subtropical Underwater are primarily responsible for the positive sea surface salinity anomalies in the central equatorial Pacific during 2014/2015, which represents an opposite phase of El Niño. These subsurface processes weakened during 2015/2016, diretly contributing to the development of the 2015/2016 El Niño. The mechanisms controlling these subsurface processes are discussed.

  3. Influence of Subtropical Jetstream on Arabian Gulf Precipitation

    Science.gov (United States)

    Sandeep, S.; Pauluis, O.; Ravindran, A. M.; TP, S.

    2017-12-01

    The Arabian Gulf and surrounding regions are predominantly arid. However, this region hosts a large population due to the intense economic activity that is centered on the exploration of natural resources in and around the Arabian Gulf. Thus, few precipitation events that occur during boreal winter are important for society and ecology of this region. The mechanisms of winter precipitation over the Gulf are not well understood, partly due to a lack of long term meteorological observation. Here we explore the dynamics of Arabian Gulf winter precipitation events using available observations and a high resolution atmospheric model simulation. Our analyses show that the northern Gulf receives about six times more precipitation than the southern Gulf. Often, the southern Gulf precipitation forms as a result of downstream development of northern Gulf disturbance. The southward movement of northern Gulf disturbances is influenced by the location of subtropical jet. The probability of a northern Gulf precipitating weather system to move south is higher when the subtropical jet is located equatorward of 30°N. The equatorward position of jet favors the penetration of mid-latitude weather systems over the Arabian Peninsula, which in turn pushes the Arabian anticyclone eastward and triggers moisture transport from the Arabian Sea that is essential for southern Gulf precipitation events.

  4. Environmental radioactivity investigations in the Georgian subtropical region

    International Nuclear Information System (INIS)

    Pagava, S.; Kakashvili, P.; Avtandilashvili, M.; Kharashvili, G.; Robakidze, Z.; Rusetski, V.; Togonidze, G.; Baratashvili, D.

    2002-01-01

    Environmental changes in the contamination of the Georgian subtropical region have been investigated by analysing anthropogenic and natural radionuclides in samples of soil and tea leaves for possible chromosome mutations. As the tea industry in Georgia is an important economic activity, such investigations are of great importance. The changes in the morphology of tea leaves, their colour, blossoming, growth inhibition or stimulation, prolongation of the germination period and levels of tanin-katechin complexes have been investigated. The results of radionuclide measurements in soil and tea leaves ( 40 K, 210 Pb and 137 Cs) are presented. Elevated concentrations of 137 Cs were observed in soil samples due to fallout from Chernobyl, however, no direct relationship between the concentration of 137 Cs in soil and tea leaves has been observed. Cyto-genetic analyses of tea primary roots will be presented and compared for different time periods. Further, ichtyofauna samples taken from the Georgian subtropical areas were analysed for anthropogenic ( 137 Cs) and natural ( 40 K) radionuclides. The observed concentrations of 137 Cs were low, close to the detection limit of the order of 0.4 Bq/kg dry weight. Some of the investigations were carried out in the framework of the IAEA Technical Co-operation project 'Marine Environmental Assessment of the Black Sea Region'

  5. Phytoplankton Growth and Microzooplankton Grazing in the Subtropical Northeast Atlantic

    Science.gov (United States)

    Cáceres, Carlos; Taboada, Fernando González; Höfer, Juan; Anadón, Ricardo

    2013-01-01

    Dilution experiments were performed to estimate phytoplankton growth and microzooplankton grazing rates during two Lagrangian surveys in inner and eastern locations of the Eastern North Atlantic Subtropical Gyre province (NAST-E). Our design included two phytoplankton size fractions (0.2–5 µm and >5 µm) and five depths, allowing us to characterize differences in growth and grazing rates between size fractions and depths, as well as to estimate vertically integrated measurements. Phytoplankton growth rates were high (0.11–1.60 d−1), especially in the case of the large fraction. Grazing rates were also high (0.15–1.29 d−1), suggesting high turnover rates within the phytoplankton community. The integrated balances between phytoplankton growth and grazing losses were close to zero, although deviations were detected at several depths. Also, O2 supersaturation was observed up to 110 m depth during both Lagrangian surveys. These results add up to increased evidence indicating an autotrophic metabolic balance in oceanic subtropical gyres. PMID:23935946

  6. Phytoplankton growth and microzooplankton grazing in the subtropical Northeast Atlantic.

    Directory of Open Access Journals (Sweden)

    Carlos Cáceres

    Full Text Available Dilution experiments were performed to estimate phytoplankton growth and microzooplankton grazing rates during two Lagrangian surveys in inner and eastern locations of the Eastern North Atlantic Subtropical Gyre province (NAST-E. Our design included two phytoplankton size fractions (0.2-5 µm and >5 µm and five depths, allowing us to characterize differences in growth and grazing rates between size fractions and depths, as well as to estimate vertically integrated measurements. Phytoplankton growth rates were high (0.11-1.60 d(-1, especially in the case of the large fraction. Grazing rates were also high (0.15-1.29 d(-1, suggesting high turnover rates within the phytoplankton community. The integrated balances between phytoplankton growth and grazing losses were close to zero, although deviations were detected at several depths. Also, O2 supersaturation was observed up to 110 m depth during both Lagrangian surveys. These results add up to increased evidence indicating an autotrophic metabolic balance in oceanic subtropical gyres.

  7. Predictors, spatial distribution, and occurrence of woody invasive plants in subtropical urban ecosystems

    Science.gov (United States)

    Christina L. Staudhammer; Francisco J. Escobedo; Nathan Holt; Linda J. Young; Thomas J. Brandeis; Wayne Zipperer; Other

    2015-01-01

    We examined the spatial distribution, occurrence, and socioecological predictors of woody invasive plants (WIP) in two subtropical, coastal urban ecosystems: San Juan, Puerto Rico and Miami-Dade, United States. These two cities have similar climates and ecosystems typical of subtropical regions but differ in socioeconomics, topography, and urbanization processes. Using...

  8. Pancreatic tissue fluid pressure during drainage operations for chronic pancreatitis

    DEFF Research Database (Denmark)

    Ebbehøj, N; Borly, L; Madsen, P

    1990-01-01

    Pancreatic tissue fluid pressure was measured in 10 patients undergoing drainage operations for painful chronic pancreatitis. The pressure was measured by the needle technique in the three anatomic regions of the pancreas before and at different stages of the drainage procedure, and the results...... a decrease in pancreatic tissue fluid pressure during drainage operations for pain in chronic pancreatitis. Regional pressure decrease were apparently unrelated to ERCP findings....

  9. Modeling of subglacial hydrological development following rapid supraglacial lake drainage

    OpenAIRE

    Dow, C F; Kulessa, B; Rutt, I C; Tsai, V C; Pimentel, S; Doyle, S H; van As, D; Lindb?ck, K; Pettersson, R; Jones, G A; Hubbard, A

    2015-01-01

    The rapid drainage of supraglacial lakes injects substantial volumes of water to the bed of the Greenland ice sheet over short timescales. The effect of these water pulses on the development of basal hydrological systems is largely unknown. To address this, we develop a lake drainage model incorporating both (1) a subglacial radial flux element driven by elastic hydraulic jacking and (2) downstream drainage through a linked channelized and distributed system. Here we present the model and exa...

  10. The construction technology of Chinese ancient city drainage facilities

    Science.gov (United States)

    Hequn, Li; Yufengyun

    2018-03-01

    In ancient china, according to the local natural environment, a variety of drainage facilities were built in order to excrete rainwater, domestic sewage, production wastewater and so on. These drainage facilities were mainly made of pottery, bricks, wood, stone, etc. For example, ceramic water pipelines, buried in the ground, connect together one by one, and there was a slight drop from one end to the other in favor of drainage. These measures can also be used for reference in today’s urban drainage and flood control.

  11. Pancreatic tissue fluid pressure during drainage operations for chronic pancreatitis

    DEFF Research Database (Denmark)

    Ebbehøj, N; Borly, L; Madsen, P

    1990-01-01

    Pancreatic tissue fluid pressure was measured in 10 patients undergoing drainage operations for painful chronic pancreatitis. The pressure was measured by the needle technique in the three anatomic regions of the pancreas before and at different stages of the drainage procedure, and the results...... were compared with preoperative endoscopic retrograde cholangiopancreatography (ERCP) morphology. The preoperatively elevated pressure decreased in all patients but one, to normal or slightly elevated values. The median pressure decrease was 50% (range, 0-90%; p = 0.01). The drainage anastomosis (a...... a decrease in pancreatic tissue fluid pressure during drainage operations for pain in chronic pancreatitis. Regional pressure decrease were apparently unrelated to ERCP findings....

  12. Pervious concrete reactive barrier for removal of heavy metals from acid mine drainage − column study

    Energy Technology Data Exchange (ETDEWEB)

    Shabalala, Ayanda N., E-mail: Ayanda.Shabalala@ump.ac.za [University of Johannesburg, PO Box 524, Auckland Park 2006 (South Africa); Ekolu, Stephen O. [University of Johannesburg, PO Box 524, Auckland Park 2006 (South Africa); Diop, Souleymane [Council for Geoscience, Private bag x112, Pretoria, 0001 (South Africa); Solomon, Fitsum [University of Johannesburg, PO Box 524, Auckland Park 2006 (South Africa)

    2017-02-05

    Highlights: • Pervious concrete raises the low pH of acid mine drainage up to 12; heavy metals precipitate. • Pervious concrete successfully removed greater than 99% of inorganic contaminants. • Ca(OH){sub 2} in pervious concrete reacts with SO{sub 4}{sup 2−} in acid mine drainage to form expansive gypsum. • Incorporating fly ash into pervious concrete mitigates damage caused by gypsum. • Pervious concrete reactive barrier offers a promising alternative method for treatment of acid mine drainage. - Abstract: This paper presents a column study conducted to investigate the potential use of pervious concrete as a reactive barrier for treatment of water impacted by mine waste. The study was done using acid mine drainage (AMD) collected from a gold mine (WZ) and a coalfield (TDB). Pervious concrete mixtures consisting of Portland cement CEM I 52.5R with or without 30% fly ash (FA) were prepared at a water-cementitious ratio of 0.27 then used to make cubes which were employed in the reactor columns. It was found that the removal efficiency levels of Al, Fe, Mn, Co and Ni were 75%, 98%, 99%, 94% and 95% for WZ; 87%, 96%, 99%, 98% and 90% for TDB, respectively. The high rate of acid reduction and metal removal by pervious concrete is attributed to dissolution of portlandite which is a typical constituent of concrete. The dominant reaction product in all four columns was gypsum, which also contributed to some removal of sulphate from AMD. Formation of gypsum, goethite, and Glauber’s salt were identified. Precipitation of metal hydroxides seems to be the dominant metal removal mechanism. Use of pervious concrete offers a promising alternative treatment method for polluted or acidic mine water.

  13. Pervious concrete reactive barrier for removal of heavy metals from acid mine drainage − column study

    International Nuclear Information System (INIS)

    Shabalala, Ayanda N.; Ekolu, Stephen O.; Diop, Souleymane; Solomon, Fitsum

    2017-01-01

    Highlights: • Pervious concrete raises the low pH of acid mine drainage up to 12; heavy metals precipitate. • Pervious concrete successfully removed greater than 99% of inorganic contaminants. • Ca(OH) 2 in pervious concrete reacts with SO 4 2− in acid mine drainage to form expansive gypsum. • Incorporating fly ash into pervious concrete mitigates damage caused by gypsum. • Pervious concrete reactive barrier offers a promising alternative method for treatment of acid mine drainage. - Abstract: This paper presents a column study conducted to investigate the potential use of pervious concrete as a reactive barrier for treatment of water impacted by mine waste. The study was done using acid mine drainage (AMD) collected from a gold mine (WZ) and a coalfield (TDB). Pervious concrete mixtures consisting of Portland cement CEM I 52.5R with or without 30% fly ash (FA) were prepared at a water-cementitious ratio of 0.27 then used to make cubes which were employed in the reactor columns. It was found that the removal efficiency levels of Al, Fe, Mn, Co and Ni were 75%, 98%, 99%, 94% and 95% for WZ; 87%, 96%, 99%, 98% and 90% for TDB, respectively. The high rate of acid reduction and metal removal by pervious concrete is attributed to dissolution of portlandite which is a typical constituent of concrete. The dominant reaction product in all four columns was gypsum, which also contributed to some removal of sulphate from AMD. Formation of gypsum, goethite, and Glauber’s salt were identified. Precipitation of metal hydroxides seems to be the dominant metal removal mechanism. Use of pervious concrete offers a promising alternative treatment method for polluted or acidic mine water.

  14. Laboratory Evaluation of Sulfur Modified Iron for Use as a Filter Material to Treat Agricultural Drainage Waters

    Science.gov (United States)

    Allred, B. J.

    2009-12-01

    Where subsurface drainage practices are employed, fertilizer nutrients and pesticides applied on farm fields and municipal locations are commonly intercepted by the buried drainage pipes and then discharged into local streams and lakes, oftentimes producing adverse environmental impacts on these surface water bodies. On-site water filter treatment systems can be employed to prevent the release of agricultural nutrients/pesticides into adjacent waterways. Sulfur modified iron is a relatively unknown industrial product that may have promise for use as a filter material to remove contaminants from subsurface drainage waters. Sulfur modified iron (SMI) is a high surface area iron powder (zero valent iron) that has been altered via chemical reaction with pure sulfur to produce a sulfur/iron surface coating on the iron particles. A laboratory investigation was conducted with contaminant removal batch tests, saturated falling-head hydraulic conductivity tests, and saturated solute transport column experiments to evaluate the feasibility for using SMI to treat subsurface drainage waters. Contaminant removal batch tests showed that three SMI samples were much more effective removing nitrate (> 94% nitrate removed) than three zero valent iron samples (pesticide, atrazine (< 37% atrazine removed). Hydraulic conductivity tests indicated that all three SMI samples that were evaluated had sufficient hydraulic conductivity, much greater than the 1 x 10-3 cm/s standard used for stormwater sand filters. The saturated solute transport tests confirmed that SMI can be effective removing nitrate and phosphate from drainage waters. Analysis of column effluent also showed that the large majority of nitrate removed by SMI was converted to ammonium. Consequently, these laboratory findings support the use of SMI in agricultural drainage water filter treatment systems, particularly when nitrate and phosphate pollution are major environmental concerns.

  15. Radioactive pollution

    International Nuclear Information System (INIS)

    Pohl, R.O.

    1976-01-01

    The widely published claims that the public health effects resulting from routine emissions are between 0.01 and 0.1 serious health effects per gigawattyear, and hence are at least a thousand times smaller than those resulting from air pollution by the burning of coal, cannot be true, for two reasons. The authors of these claims have ignored at least two of the more important isotopes, radon-222 and carbon-14, which are presently released to the environment, and thus contribute greatly to the health impact of nuclear energy. The health effects calculated in the earlier work cover only those which occur during the year in which the energy is generated. This means, figuratively speaking, that the authors have confused an annual installment payment with the full cost. This is unacceptable. The contribution to the health impact of nuclear energy arising from the single isotopic species radon-222 emanating from the mill tailings is estimated to 400 lung cancer deaths/GW(e)y, larger even than the most pessimistic estimates of the health impact of energy from coal through atmospheric pollution. We have no assurance that other long-lived isotopes do not contribute comparable amounts to the health impact of nuclear energy. The discussion of the health impact of radon-222 raises the fundamental moral question--how far into the future our responsibility extends. If such a long-termresponsibility is rejected, then we must at least try to predict the environmental buildup of radioactive pollutants, in order to avoid unacceptable and irreversible levels of radiation dose rate. The potential health consequences from long-lived radioisotopes seem to have been largely ignored so far, and should be explored in detail

  16. An Integrative Study of Photochemical Air Pollution in Hong Kong: an Overview

    Science.gov (United States)

    Wang, T.

    2014-12-01

    Hong Kong is situated in the Pearl River delta of Southern China. This region has experienced phenomenal economic growth in the past 30 years. Emissions of large amount of pollutants from urban areas and various industries coupled with subtropical climate have led to frequent occurrences of severe photochemical air pollution. Despite the long-term control efforts of the Hong Kong government, the atmospheric levels of ozone have been increasing in the past decade. To obtain an updated and more complete understanding of photochemical smog, an integrative study has been conducted during 2010-2014. Several intensive measurement campaigns were carried out at urban, suburban and rural sites in addition to the routine observations at fourteen air quality monitoring stations in Hong Kong. Meteorological, photochemical, and chemical-transport modeling studies were conducted to investigate the causes/processes of elevated photochemical pollution . The main activities of this study were to (1) examine the situation and trends of photochemical air pollution in Hong Kong, (2) understand some underlying chemical processes in particular the poorly-understood heterogeneous processes of reactive nitrogen oxides, (3) quantify the local, regional, and super-regional contributions to the ozone pollution in Hong Kong, and (4) review the control policy and make further recommendations based on the science. This paper will give an overview of this study and present some key results on the trends and chemistry of the photochemical pollution in this polluted subtropical region.

  17. Marine pollution

    International Nuclear Information System (INIS)

    Gerlach, S.A.

    1981-01-01

    The author of this book has combined his own vast experience as a marine biologist with a critical evaluation of the ever-increasing literature in a work which highlights those longterm effects and dangerous materials most threatening on a global scale. This English translation of the highly acclaimed German original has been revised and expanded to keep pace with the rapid process of research in the field. A particularly large number of changes were made in the chapter on oil pollution, and new chapters on waste heat and radioactivity in the ocean have been added. (orig.)

  18. Upstream Subtropical Signals Preceding the Asian Summer Monsoon Circulation.

    Science.gov (United States)

    Yang, Song; Lau, K.-M.; Yoo, S.-H.; Kinter, J. L.; Miyakoda, K.; Ho, C.-H.

    2004-11-01

    In this study, the authors address several issues with respect to the antecedent signals of the large-scale Asian summer monsoon that were earlier identified by Webster and Yang. In particular, they revisit the changes in the subtropical upper-tropospheric westerlies preceding the monsoon, depict the detailed structure of the monsoon's antecedent signals, and investigate the physical processes from the signals to the monsoon. They also explore the teleconnection of these signals to various large-scale climate phenomena and emphasize the importance of the upstream location of the signals relative to the Tibetan Plateau and the monsoon.Before a strong (weak) Asian summer monsoon, the 200-mb westerlies over subtropical Asia are weak (strong) during the previous winter and spring. A significant feature of these signals is represented by the variability of the Middle East jet stream whose changes are linked to the Arctic Oscillation, North Atlantic Oscillation, El Niño Southern Oscillation, and other climate phenomena. When this jet stream intensifies and shifts southeastward, cold air intrudes frequently from eastern Europe into the Middle East and southwestern Asia. As a result, in subtropical Asia, snow and precipitation increase, the ground wetness increases, and surface temperature decreases. A strengthening Middle East jet stream is also accompanied by increases in both stationary wave activity flux and higher-frequency eddy activities. The Tibetan Plateau acts to block these westerly activities propagating eastward and increase the persistence of the low-temperature anomalies, which in turn prolongs the atmospheric signals from winter to spring.A strong link is found between the persistent low-temperature anomalies and the decrease in geopotential height over southern Asia, including the Tibetan Plateau, in spring. The latter indicates a late establishment of the South Asian high, and implies a delay in the atmospheric transition from winter to summer conditions

  19. The Subtropical Grasslands LTAR: balancing agricultural production and conservation goals

    Science.gov (United States)

    Gomez-Casanovas, N.; Boughton, E.; Bernacchi, C.; DeLucia, E. H.; Sparks, J. P.; Silveira, M.; Boughton, R. K.; Swain, H.

    2015-12-01

    Subtropical grazing lands of peninsular Florida have been shaped by a long evolutionary history of lightning ignited fire followed by flooding resulting in a vast treeless prairie region in south-central Florida. In these grassland ecosystems fire return intervals are between 1-3 years. Beginning in the 1500's, Andalusian cattle began grazing in this region and the cattle industry began in earnest in the late 1800s/early 1900s. Today, Florida's prairie region is largely occupied by cow/calf ranch operations and also occupies the Northern Everglades watershed where water quality/quantity issues are at the forefront of environmental concerns. Florida ranches are characterized by a gradient of management intensities, ranging from sown pastures (most intensively managed) to semi-native pastures with a mix of introduced and native grasses, and rangeland (least managed ecosystem). Located at Archbold Biological Station, MacArthur Agro-ecology Research Center, and University of Florida Range Cattle Research Center (www.maerc.org; www.rcrec-ona.ifas.ufl.edu), a primary goal of the Subtropical Grasslands US Department of Agriculture Long-term Agro-Ecosystem Research LTAR is to balance intensification of sown pastures while enhancing management of native systems in a way that maximizes other ecosystem services (regulating, supporting, cultural, biodiversity). Here, we describe our proposed experimental design to compare ecosystem delivery from conventional and aspirational management regimes in sown pastures and native systems. Aspirational management goals are to (i) maximize productivity in sown pastures with a neutral effect on other ecosystem services, and (ii) manage native systems in a way that maximizes regulating, supporting, and biodiversity ecosystem services by utilizing patch burn grazing. Ultimately, we will determine if enhanced production in sown pasture under the aspirational management system can offset any reduction in productivity in semi

  20. The Effects of Coarse Particles on Daily Mortality: A Case-Crossover Study in a Subtropical City, Taipei, Taiwan

    Directory of Open Access Journals (Sweden)

    Meng-Hsuan Cheng

    2016-03-01

    Full Text Available Many studies have examined the effects of air pollution on daily mortality over the past two decades. However, information on the relationship between levels of coarse particles (PM2.5–10 and daily mortality is relatively sparse due to the limited availability of monitoring data. Furthermore, the results are inconsistent. In the current study, the association between coarse particle levels and daily mortality in Taipei, Taiwan’s largest city, which has a subtropical climate, was undertaken for the period 2006–2008 using a time-stratified case-crossover analysis. For the single pollutant model (without adjustment for other pollutants, PM2.5–10 showed statistically significant association with total mortality both on warm and cool days, with an interquartile range increase associated with a 11% (95% CI = 6%–17% and 4% (95% CI = 1%–7% rise in number of total deaths, respectively. In two-pollutant models, PM2.5–10 remained significant effects on total mortality after the inclusion of SO2 and O3 both on warm and cool days. We observed no significant associations between PM2.5–10 and daily mortality from respiratory diseases both on warm and cool days. For daily mortality from circulatory diseases, the effect of PM2.5–10 remained significant when SO2 or O3 was added in the regression model both on warm and cool days. Future studies of this type in cities with varying climates and cultures are needed.

  1. Exact solutions for nonlinear foam drainage equation

    Science.gov (United States)

    Zayed, E. M. E.; Al-Nowehy, Abdul-Ghani

    2017-02-01

    In this paper, the modified simple equation method, the exp-function method, the soliton ansatz method, the Riccati equation expansion method and the ( G^' }/G)-expansion method are used to construct exact solutions with parameters of the nonlinear foam drainage equation. When these parameters are taken to be special values, the solitary wave solutions and the trigonometric function solutions are derived from the exact solutions. The obtained results confirm that the proposed methods are efficient techniques for analytic treatments of a wide variety of nonlinear partial differential equations in mathematical physics. We compare our results together with each other yielding from these integration tools. Also, our results have been compared with the well-known results of others.

  2. Irrigation drainage: Green River basin, Utah

    Science.gov (United States)

    Stephens, Doyle W.; Waddell, Bruce; Miller, Jerry B.

    1988-01-01

    A reconnaissance of wildlife areas in the middle Green River basin of Utah during 1986-87 determined that concentrations of selenium in water and biological tissues were potentially harmful to wildlife at the Stewart Lake Waterfowl Management Area and in the Ouray National Wildlife Refuge. Concentations of selenium in irrigation drainage entering Stewart Lake ranged from 14 to 140 micrograms per liter; liver tissue from coots collected from the lake contained selenium concentrations of as much as 26 micrograms per gram and samples of tissue from carp contained as much as 31 micrograms per gram. Concentrations of selenium in a pond at the Ouray National Wildlife Refuge, which receives irrigation water and shallow ground water, were as much as 93 micrograms per liter. Liver tissue from coots collected from this pond contained selenium concentrations of as much as 43 micrograms per gram; eggs of water birds contained as much as 120 micrograms per gram.

  3. Drainage basins and channel incision on Mars

    Science.gov (United States)

    Aharonson, Oded; Zuber, Maria T.; Rothman, Daniel H.; Schorghofer, Norbert; Whipple, Kelin X.

    2002-02-01

    Measurements acquired by the Mars Orbiter Laser Altimeter on board the Mars Global Surveyor indicate that large drainage systems on Mars have geomorphic characteristics inconsistent with prolonged erosion by surface runoff. We find the topography has not evolved to an expected equilibrium terrain form, even in areas where runoff incision has been previously interpreted. By analogy with terrestrial examples, groundwater sapping may have played an important role in the incision. Longitudinally flat floor segments may provide a direct indication of lithologic layers in the bedrock, altering subsurface hydrology. However, it is unlikely that floor levels are entirely due to inherited structures due to their planar cross-cutting relations. These conclusions are based on previously unavailable observations, including extensive piece-wise linear longitudinal profiles, frequent knickpoints, hanging valleys, and small basin concavity exponents.

  4. Electrocoagulation treatment of peat bog drainage water containing humic substances.

    Science.gov (United States)

    Kuokkanen, V; Kuokkanen, T; Rämö, J; Lassi, U

    2015-08-01

    Electrocoagulation (EC) treatment of 100 mg/L synthetic wastewater (SWW) containing humic acids was optimized (achieving 90% CODMn and 80% DOC removal efficiencies), after which real peat bog drainage waters (PBDWs) from three northern Finnish peat bogs were also treated. High pollutant removal efficiencies were achieved: Ptot, TS, and color could be removed completely, while Ntot, CODMn, and DOC/TOC removal efficiencies were in the range of 33-41%, 75-90%, and 62-75%, respectively. Al and Fe performed similarly as the anode material. Large scale experiments (1 m(3)) using cold (T = 10-11 °C) PBDWs were also conducted successfully, with optimal treatment times of 60-120 min (applying current densities of 60-75 A/m(2)). Residual values of Al and Fe (complete removal) were lower than their initial values in the EC-treated PBDWs. Electricity consumption and operational costs in optimum conditions were found to be low and similar for all the waters studied: 0.94 kWh/m(3) and 0.15 €/m(3) for SWW and 0.35-0.70 kWh/m(3) and 0.06-0.12 €/m(3) for the PBDWs (large-scale). Thus, e.g. solar cells could be considered as a power source for this EC application. In conclusion, EC treatment of PBDW containing humic substances was shown to be feasible. Copyright © 2015 Elsevier Ltd. All rights reserved.

  5. Chemical aspects of acid mine drainage

    Energy Technology Data Exchange (ETDEWEB)

    Barnes, H.L. (Pennsylvania State Univ., University Park); Romberger, S.M.

    1968-01-01

    The elemental environment and causes of acid formation are discussed to establish a basis for water pollution abatement or control. Isolation is the preferred treatment where hydrologic conditions are favorable; or liming is considered as a second choice. For flooded mines sulfate-reducing bacteria deserves testing. Sealing of mines to forestall oxidation by excluding air is seen as too costly.

  6. Integrated urban drainage, status and perspectives

    DEFF Research Database (Denmark)

    Harremoës, Poul

    2002-01-01

    measures are local infiltration, source control, storage basins, local treatment and real time control. New paradigms have been introduced: risk of pollution due to system failure, technology for water reuse, sustainability, new architecture and greener up-stream solutions as opposed to down......-stream concrete solutions. The challenge is to combine the inherited approaches with the new approaches by flexibility and adaptability....

  7. Subtropical freshwater event at the onset of Younger Dryas

    Science.gov (United States)

    Weinelt, M.; Repschläger, J.; Balmer, S.; Schwab, C.; Andersen, N.; Blanz, T.; Sarnthein, M.

    2012-12-01

    The Younger Dryas (YD) (12.79-11.6 ka BP) cold spell during the last deglaciation is associated with a major breakdown of the Atlantic meridional overturning circulation (AMOC), the details of which are still controversial. Catastrophic events like a bolide impact or a major outflow of meltwater stored in the proglacial Lake Agassiz, which led to the capping of North Atlantic deep water convection sites, have been suggested to trigger the AMOC shutdown. However the geomorphological evidence for such a meltwater flood is not in agreement with the timing of the YD. Also, the YD was postulated to be part of a deglacial sequence of events generally characteristic of glacial terminations involving the displacement of major climatic zones and oceanographic fronts. We present detailed paleoceanographic records from sediment cores MD08-3180/ GEOFAR KF16 (38°N; 31.13°W, 3050 m w.d.) retrieved immediately east of the Mid Atlantic ridge south of the Azores Islands. At present, this site is located at the northern rim of the Azores Current, which delineates the subtropical gyre, recirculating warm waters of the North Atlantic Current. Due to its position at the boundary between temperate North East Atlantic waters and subtropical gyre waters, the site is ideally suited to trace past changes in the alternating influence of both water masses. Parallel stable-oxygen isotope records of surface water dwelling foraminifera Globigerinoides ruber w. (habitat depth 0-25m) and Globigerina bulloides (habitat depth 0-300m) may document the structure of surface waters. Sea Surface Temperatures (SST) were derived from the UK'37 index and from planktonic foraminifera (PF) assemblages using transfer functions. d18Ow-ice and Sea Surface Salinities were estimated using the d18O G.ruber w. record corrected for SST and changes in global ice volume. The d18O records of G.ruber w. and G.bulloides diverge between 13.4 ka and 12.95 ka BP. d18Ow data show a gradual increase in the freshening of

  8. ROOT ALLOMETRY OF TWO SUBTROPICAL PLANT COMMUNITIES OF NORTHEASTERN MEXICO

    Directory of Open Access Journals (Sweden)

    Jose de Jesus Navar Chaidez

    2009-06-01

    Full Text Available This research work aimed at the study of the root allometry in subtropical Tamaulipan thornscrub and pine forest communities of Nuevo Leon, Mexico. By excavating each individual root of each of 20 trees per plant community, we developed root allometric equations for biomass, volume, total length and diameter. Covariance analysis, ancova, was employed to determine the statistical difference of these parameters between plant communities. Results indicate that pine plant trees have larger root volumes, longer root systems and higher root basic densities than trees of Tamaulipan thornscrub forests. This piece of information is key to estimate root biomass, volume, total length and diameter of roots of trees of these plant communities at the stand scale; important environmental information.Key words: Power equations, ancova, root biomass, volume, length and diameter.

  9. Estimating the benefits of improved drainage on pavement ...

    African Journals Online (AJOL)

    user

    The drainage quality is an important parameter which affects the performance of highway pavements. In India ... pavement performance and maintenance needs; and (iii) to quantify the benefits in terms of cost due to the improved drainage ...... Jain was the founder Head of Excellence in Transportation Systems (CTRANS),.

  10. Remediation of Acid Mine Drainage with Sulfate Reducing Bacteria

    Science.gov (United States)

    Hauri, James F.; Schaider, Laurel A.

    2009-01-01

    Sulfate reducing bacteria have been shown to be effective at treating acid mine drainage through sulfide production and subsequent precipitation of metal sulfides. In this laboratory experiment for undergraduate environmental chemistry courses, students design and implement a set of bioreactors to remediate acid mine drainage and explain observed…

  11. Development Of An Agricultural Land Drainage And Reclamation ...

    African Journals Online (AJOL)

    Development Of An Agricultural Land Drainage And Reclamation Design Software. ... Journal of the Ghana Institution of Engineers ... The design of appropriate drainage structures however often involves complex hydrological, hydraulic and engineering computations and the use of charts, tables and nomographs, etc.

  12. The Random Walk Drainage Simulation Model as a Teaching Exercise

    Science.gov (United States)

    High, Colin; Richards, Paul

    1972-01-01

    Practical instructions about using the random walk drainage network simulation model as a teaching excercise are given and the results discussed. A source of directional bias in the resulting simulated drainage patterns is identified and given an interpretation in the terms of the model. Three points of educational value concerning the model are…

  13. Coupling between drainage and coarsening in wet foam

    Indian Academy of Sciences (India)

    Adjacent bubbles coalesce when the liquid border becomes too thin. In addition to drainage, the other process, which changes the macroscopic appearance of foam is the coars- ening. This occurs due to the gas diffusion from smaller to larger bubbles following the well-known Laplace–Young law [1]. Both effects, drainage ...

  14. Coupling between drainage and coarsening in wet foam

    Indian Academy of Sciences (India)

    Drainage and coarsening are two coupled phenomena during the evolution of wet foam. We show the variation in the growth rate of bubble size, along the height in a column of Gillette shaving foam, by microscope imaging. Simultaneously, the drainage of liquid at the same heights has been investigated by Raman ...

  15. Adequacy of Drainage Channels in a Small Urban Watershed in ...

    African Journals Online (AJOL)

    This research presents an analysis for the adequacy of drainage channels. Topographical and location map was used as a guide to locate the drainage channels. Rainfall records for a period of four years (2008-2011) were used to develop the intensity bdurationB B frequency of the study area . Field survey and geometrical ...

  16. Assessment of drainage techniques for evacuation of chronic subdural hematoma

    DEFF Research Database (Denmark)

    Sjåvik, Kristin; Bartek, Jiri; Sagberg, Lisa Millgård

    2018-01-01

    OBJECTIVE Surgery for chronic subdural hematoma (CSDH) is one of the most common neurosurgical procedures. The benefit of postoperative passive subdural drainage compared with no drains has been established, but other drainage techniques are common, and their effectiveness compared with passive s...

  17. A new approach in research into drainage materials

    NARCIS (Netherlands)

    Stuyt, L.C.P.M.

    1981-01-01

    In the past decades in many countries installation of agricultural drainage systems' has evolved into an almost completely mechanized operation. Progress in technology has been remarkable and drainage engineers obviously could not keep pace with enhanced research requirements:introduction of new

  18. Coupling between drainage and coarsening in wet foam

    Indian Academy of Sciences (India)

    Abstract. Drainage and coarsening are two coupled phenomena during the evolution of wet foam. We show the variation in the growth rate of bubble size, along the height in a column of Gillette shaving foam, by microscope imaging. Simultaneously, the drainage of liquid at the same heights has been investigated by ...

  19. 13 Morphometric Analysis of Ogunpa and Ogbere Drainage Basins ...

    African Journals Online (AJOL)

    `123456789jkl''''#

    The paper analysed the morphometric parameters of Ogbere and Ogunpa drainage basins located on basement complex rock in ... properties of Ogunpa drainage basin are likely to induce high magnitude flood compared to morphometric properties of Ogbere ..... Bs = VI/HE where Bs = Basin slope, VI = Vertical Interval and.

  20. Preoperative percutaneous transhepatic drainage: use or abuse. A clinical review

    NARCIS (Netherlands)

    Gouma, D. J.; Moody, F. G.

    1984-01-01

    The benefit of preoperative percutaneous transhepatic biliary drainage in patients with obstructive jaundice was reviewed in the literature from 1974 to July 1984. The role of preoperative drainage cannot be definitively assessed. Significant reduction of morbidity and mortality has been reported in

  1. Using bamboo (Bambusa vulgaris) as a field drainage material in ...

    African Journals Online (AJOL)

    Bamboo (Bambusa vulgaris), one of the most widespread member of its genus, was used as field drainage material in Akure, Nigeria. Pre-determined sizes of bamboo with uniform lengths and diameters were installed as sub-drains in agricultural field for drainage purposes, especially in developing countries like Nigeria.

  2. 7 CFR 1924.108 - Grading and drainage.

    Science.gov (United States)

    2010-01-01

    ... drainage. (a) General. Soil and geologic conditions must be suitable for the type of construction proposed... affect the structure and show proposed solutions. Grading will promote drainage of surface water away... Agriculture Regulations of the Department of Agriculture (Continued) RURAL HOUSING SERVICE, RURAL BUSINESS...

  3. Thematic survey of subsurface drainage systems in the Czech Republic

    Czech Academy of Sciences Publication Activity Database

    Tlapáková, L.; Žaloudík, J.; Kolejka, Jaromír

    2016-01-01

    Roč. 13, č. 2 (2016), s. 55-65 ISSN 1744-5647 Institutional support: RVO:68145535 Keywords : subsurface drainage system * remote sensing * image interpretation * drainage recognition and mapping Subject RIV: DE - Earth Magnetism, Geodesy, Geography Impact factor: 2.174, year: 2016 http://www.tandfonline.com/doi/full/10.1080/17445647.2016.1259129?scroll=top&needAccess=true

  4. Pancreaticoduodenectomy with External Drainage of the Pancreatic Remnant

    OpenAIRE

    Suvit Sriussadaporn; Rattaplee Pak-art; Sukanya Sriussadaporn; Kritaya Kritayakirana; Supparerk Prichayudh

    2008-01-01

    Leakage of the pancreaticojejunal anastomosis is a serious complication after pancreaticoduodenectomy. External drainage of the pancreatic remnant is one of several methods for reducing pancreaticojejunal anastomotic leakage or fistula. We investigated complications after pancreaticoduodenectomy with and without external drainage of the pancreatic remnant. METHODS: Patients who underwent pancreaticoduodenectomy at King Chulalongkorn Memorial Hospital, Bangkok, Thailand from November 1991 t...

  5. Modeling of subglacial hydrological development following rapid supraglacial lake drainage

    Science.gov (United States)

    Dow, C. F.; Kulessa, B.; Rutt, I. C.; Tsai, V. C.; Pimentel, S.; Doyle, S. H.; van As, D.; Lindbäck, K.; Pettersson, R.; Jones, G. A.; Hubbard, A.

    2015-06-01

    The rapid drainage of supraglacial lakes injects substantial volumes of water to the bed of the Greenland ice sheet over short timescales. The effect of these water pulses on the development of basal hydrological systems is largely unknown. To address this, we develop a lake drainage model incorporating both (1) a subglacial radial flux element driven by elastic hydraulic jacking and (2) downstream drainage through a linked channelized and distributed system. Here we present the model and examine whether substantial, efficient subglacial channels can form during or following lake drainage events and their effect on the water pressure in the surrounding distributed system. We force the model with field data from a lake drainage site, 70 km from the terminus of Russell Glacier in West Greenland. The model outputs suggest that efficient subglacial channels do not readily form in the vicinity of the lake during rapid drainage and instead water is evacuated primarily by a transient turbulent sheet and the distributed system. Following lake drainage, channels grow but are not large enough to reduce the water pressure in the surrounding distributed system, unless preexisting channels are present throughout the domain. Our results have implications for the analysis of subglacial hydrological systems in regions where rapid lake drainage provides the primary mechanism for surface-to-bed connections.

  6. Evaluating the Acid Mine Drainage Potential at Abosso Goldfields ...

    African Journals Online (AJOL)

    Occurrence of Acid Rock Drainae (ARD) affects both plants and animals that are present in a drainage system. In some base metal and coal mining environments, the presence of sulphide minerals especially pyrite and their exposure to oxygen and water may trigger Acid Mine Drainage (AMD). Evaluation of the potential for ...

  7. Strike slip faulting inferred from offsetting of drainages: Lower ...

    Indian Academy of Sciences (India)

    The detailed analysis of landforms,drainages and geology of the area between the rivers Amaravati and Karjan was carried out in order to understand the tectonic history of the lower Narmada basin. Movement along the various faults in the area was studied on the basis of the drainage offsetting. Horizontal offsetting of ...

  8. Fate of pesticides in the arid subtropics, Botswana, Southern Africa.

    Science.gov (United States)

    Shunthirasingham, Chubashini; Mmereki, Baagi T; Masamba, Wellington; Oyiliagu, Catherine E; Lei, Ying D; Wania, Frank

    2010-11-01

    Despite a history of pesticide usage, few data exist on their concentrations in air and soil of Southern Africa. To add to the understanding of the processes controlling the fate of organic contaminants in arid regions, the levels, spatial trends, and seasonal variability of pesticides were studied in air and soil from Botswana. XAD resin-based passive air samplers (PAS) were deployed at 15 sites across the country from May 2006 to May 2007. Soil samples were collected from the vicinity of nine of the PAS sampling sites. In addition, 27 24-h high-volume air samples were collected in Maun, at the southeastern edge of the Okavango Delta, every two weeks for one year. Levels of pesticides in PAS were low, with α-endosulfan and lindane being most abundant. Concentrations in soils were extremely low and only soils with high organic carbon contained notable amounts of dieldrin and traces of other pesticides. In particular, air and soil from the Okavango Delta had very low levels even though the area had repeatedly been sprayed with DDT and endosulfan in the past. Air samples from Eastern Botswana, where the majority of the population lives, contained higher levels. Higher air concentrations of α-endosulfan occurred during summer and higher HCB levels occurred in winter. This seasonality was related with neither minor seasonal changes in temperature nor hydrological seasonal events such as the rainy season or the flooding of the Okavango Delta. Thus, the observed spatial and seasonal patterns are more likely related to pesticide usage pattern than to environmental factors or historical use. High temperature and low organic matter content limit the uptake capacity of most subtropical soils for pesticides. No evidence was found that sorption to dry mineral matter plays a major role. Arid soils in subtropical regions are therefore neither a major reservoir of organic contaminants nor do they constitute a significant long-term source of pesticides to the atmosphere.

  9. Biodiversity promotes tree growth during succession in subtropical forest.

    Directory of Open Access Journals (Sweden)

    Martin Barrufol

    Full Text Available Losses of plant species diversity can affect ecosystem functioning, with decreased primary productivity being the most frequently reported effect in experimental plant assemblages, including tree plantations. Less is known about the role of biodiversity in natural ecosystems, including forests, despite their importance for global biogeochemical cycling and climate. In general, experimental manipulations of tree diversity will take decades to yield final results. To date, biodiversity effects in natural forests therefore have only been reported from sample surveys or meta-analyses with plots not initially selected for diversity. We studied biomass and growth of subtropical forests stands in southeastern China. Taking advantage of variation in species recruitment during secondary succession, we adopted a comparative study design selecting forest plots to span a gradient in species richness. We repeatedly censored the stem diameter of two tree size cohorts, comprising 93 species belonging to 57 genera and 33 families. Tree size and growth were analyzed in dependence of species richness, the functional diversity of growth-related traits, and phylogenetic diversity, using both general linear and structural equation modeling. Successional age covaried with diversity, but differently so in the two size cohorts. Plot-level stem basal area and growth were positively related with species richness, while growth was negatively related to successional age. The productivity increase in species-rich, functionally and phylogenetically diverse plots was driven by both larger mean sizes and larger numbers of trees. The biodiversity effects we report exceed those from experimental studies, sample surveys and meta-analyses, suggesting that subtropical tree diversity is an important driver of forest productivity and re-growth after disturbance that supports the provision of ecological services by these ecosystems.

  10. Biodiversity promotes tree growth during succession in subtropical forest.

    Science.gov (United States)

    Barrufol, Martin; Schmid, Bernhard; Bruelheide, Helge; Chi, Xiulian; Hector, Andrew; Ma, Keping; Michalski, Stefan; Tang, Zhiyao; Niklaus, Pascal A

    2013-01-01

    Losses of plant species diversity can affect ecosystem functioning, with decreased primary productivity being the most frequently reported effect in experimental plant assemblages, including tree plantations. Less is known about the role of biodiversity in natural ecosystems, including forests, despite their importance for global biogeochemical cycling and climate. In general, experimental manipulations of tree diversity will take decades to yield final results. To date, biodiversity effects in natural forests therefore have only been reported from sample surveys or meta-analyses with plots not initially selected for diversity. We studied biomass and growth of subtropical forests stands in southeastern China. Taking advantage of variation in species recruitment during secondary succession, we adopted a comparative study design selecting forest plots to span a gradient in species richness. We repeatedly censored the stem diameter of two tree size cohorts, comprising 93 species belonging to 57 genera and 33 families. Tree size and growth were analyzed in dependence of species richness, the functional diversity of growth-related traits, and phylogenetic diversity, using both general linear and structural equation modeling. Successional age covaried with diversity, but differently so in the two size cohorts. Plot-level stem basal area and growth were positively related with species richness, while growth was negatively related to successional age. The productivity increase in species-rich, functionally and phylogenetically diverse plots was driven by both larger mean sizes and larger numbers of trees. The biodiversity effects we report exceed those from experimental studies, sample surveys and meta-analyses, suggesting that subtropical tree diversity is an important driver of forest productivity and re-growth after disturbance that supports the provision of ecological services by these ecosystems.

  11. Environmental Pollution: Noise Pollution - Sonic Boom

    Science.gov (United States)

    1977-06-01

    UNCLASSIFIED AD-A041 400 DDC/BIB-77/06 ENVIRONMENTAL POLLUTION NOISE POLLUTION SONIC BOOM A DDC BIBLIOGRAPHY DDC-TAS Cameron Station Alexandria, Va...rn7Sttio 658S-A041 400 4 TITLE xand r.VuhtlVlia) 2 TA i b- 1iblog ra ph y ENVIRONMENTAL POLLUTION : --. Apr-l IM59-Jul, 7NOISE POLLUTION -SONIC BOOM. 1,976...BIBLIOGRAPHY SEARCH CONTROL NO. /2OM09 AD- 769 970 20/1 1/3 DEFENSE UOCUMENTATION CENTER ALEXANDRIA VA ENVIRONMENTAL POLLUTION : NOISE POLLUTION

  12. Long-Term Changes in the Water Quality and Macroinvertebrate Communities of a Subtropical River in South China

    Directory of Open Access Journals (Sweden)

    Kun Li

    2014-12-01

    Full Text Available Subtropical rivers support a highly diverse array of benthic macroinvertebrates. In this study, by combining historical data and new data, we identified specific changes in the Guanlan River, in South China, from 1981 to 2011, and evaluated the effectiveness of an ecological restoration project under highly polluted conditions. From 1981 to 2011, the water quality in the Guanlan River underwent three major stages. With the deterioration of water quality, there was an overall decrease in the species number of macroinvertebrates in the Guanlan River, an increase in macroinvertebrate density, and a reduction of the biodiversity, and a reduction of functional feeding groups. In 2011, after five years of comprehensive remediation, the Guanlan River was somewhat improved. Macroinvertebrate biodiversity in the middle reach of the Guanlan River, where a key ecological restoration engineering project was implemented, did not differ significantly from other sites. This finding indicates that the effectiveness of ecological restoration measures in highly polluted rivers, particularly at the reach-scale, is very limited and even ineffective.

  13. Numerical Three-Dimensional Model of Airport Terminal Drainage System

    Directory of Open Access Journals (Sweden)

    Strzelecki Michał

    2014-03-01

    Full Text Available During the construction of an airport terminal it was found that as a result of the hydrostatic pressure of underground water the foundation plate of the building had dangerously shifted in the direction opposite to that of the gravitational forces. The only effective measure was to introduce a drainage system on the site. The complex geology of the area indicated that two independent drainage systems, i.e., a horizontal system in the Quaternary beds and a vertical system in the Tertiary water-bearing levels, were necessary. This paper presents numerical FEM calculations of the two drainage systems being part of the airport terminal drainaged esign. The computer simulation which was carried out took into consideration the actual effect of the drainage systems and their impact on the depression cone being formed in the two aquifers.

  14. Drainage filter technologies to mitigate site-specific phosphorus losses

    DEFF Research Database (Denmark)

    Kjærgaard, Charlotte; Heckrath, Goswin Johann; Iversen, Bo Vangsø

    2014-01-01

    of implementing the drainage filter technologies including surface-flow constructed wetlands, subsurface flow constructed wetlands, and drainage well filters (www.supremetech.dk). We will present results on P retention from (i) controlled column experiments with permeable filter substrates, and (ii) a full...... high risks areas of P loss and applying site-specific measures therefore seems a more cost-efficient approach. The Danish Commission for Nature and Agriculture has now called for a shift of paradigm towards targeted mitigation and development of new, cost-efficient technologies to mitigate site......-specific nutrient losses in drainage. The “SUPREME-TECH” project (2010-2015), funded by the Danish Strategic Research Council, aims at providing the scientific basis for developing cost-effective drainage filter technologies to retain P in agricultural drainage waters. The project studies different approaches...

  15. Organic pollutants and heavy metals in rainwater runoff and their fate in the unsaturated soil zone. Final report

    International Nuclear Information System (INIS)

    Grotehusmann, D.; Rohlfing, R.; Weyer, G.; Dittrich, D.; Gowik, P.; Pernak, P.

    1991-01-01

    This bibliographic study is part of the BMFT intergrated project ''Possibilitiis and limits of [ drainage in consederation of the soil and groundwater protection''. Subjects: Environmental relevance and general distribution of organic pollutants; organic pollutants in rain water, soil, and groundwater; fate of organic pollutants in soil; environmental relevance of heavy metals in soil, rain water, and runof; fate of heavy metals in the unsaturated soil rare. (orig./BBR) [de

  16. Proceedings of the international land reclamation and mine drainage conference and third international conference on the abatement of acidic drainage. Volume 1: Mine drainage -- SP 06A-94

    International Nuclear Information System (INIS)

    Anon.

    1994-01-01

    Volume 1 of these proceedings is divided into the following sections: Modeling mine water quality; Water treatment with wetlands; Predicting mine water quality; Water treatment--Chemical; Control of acid mine drainage--Wet covers; Site characterization monitoring; Control of acid mine drainage--Alkaline addition; and Mine water geochemistry. Papers dealing with or applicable to coal or uranium mining have been processed separately for inclusion on the data base

  17. Resilience of Socio-Hydrological Systems in Canadian Prairies to Agricultural Drainage: Policy Analysis and Modelling Approach

    Science.gov (United States)

    Wheater, H. S.; Xu, L.; Gober, P.; Pomeroy, J. W.; Wong, J.

    2017-12-01

    Extensive agricultural drainage of lakes and wetlands in the Canadian Prairies has led to benefits for agricultural production, but has had a substantial influence on hydrological regimes and wetland extent. There is need for the potential impacts of current policy in changing the socio-hydrological resilience of prairie wetland basins in response to agricultural drainage to be examined. Whilst wetland drainage can increase agricultural productivity, it can also reduce stocks of natural capital and decrease ecosystem services, such as pollutant retention, habitat for waterfowls, carbon sequestration, and downstream flood attenuation. Effective policies that balance drainage benefits and negative externalities have to consider pricing. This is explored here using the Cold Regions Hydrological Model for hydrological simulations and the Inclusive Wealth approach for modelling in support of cost-benefit analysis. Inclusive wealth aggregates the value of natural, human, and technological assets used to produce social welfare. A shadow price, defined as the marginal change in social value for a marginal change in the current stock quantity, is used to valuate assets that contribute to social welfare. The shadow price of each asset is estimated by taking into account the social and economic benefits and external losses of wetland services caused by wetland drainage. The coupled model was applied to the Smith Creek Research Basin in south-eastern Saskatchewan, Canada where wetland drainage has caused major alterations of the hydrological regime including increased peak flows, discharge volumes and duration of streamflow. Changes in depressional storage in wetlands was used to calculate the corresponding changes of inclusive wealth over a 30-year period under the impacts from the limitation proposed in the Agricultural Water Management Strategy of Saskatchewan. The adjusted societal values of drainage demonstrate the dynamics between changes in hydrological conditions of

  18. Preoperative Biliary Drainage in Patients with Resectable Perihilar Cholangiocarcinoma: Is Percutaneous Transhepatic Biliary Drainage Safer and More Effective than Endoscopic Biliary Drainage? A Meta-Analysis.

    Science.gov (United States)

    Al Mahjoub, Aimen; Menahem, Benjamin; Fohlen, Audrey; Dupont, Benoit; Alves, Arnaud; Launoy, Guy; Lubrano, Jean

    2017-04-01

    To determine the best initial procedure for performing preoperative biliary drainage in patients with resectable perihilar cholangiocarcinoma (PHCC). MEDLINE/PubMed and the Cochrane database were searched for all studies published until June 2016 comparing endoscopic biliary drainage (EBD) and percutaneous transhepatic biliary drainage (PTBD) for preoperative biliary drainage. Meta-analysis was performed by using Review Manager 5.3 software. Four retrospective studies were identified that met the criteria. The analysis was performed on 433 patients who underwent preoperative biliary drainage for resectable PHCC. Of those, 275 (63.5%) had EBD and 158 (36.5%) had PTBD as the initial procedure. The overall procedure-related morbidity rate was significantly lower in the PTBD group than in the EBD group (39 of 147 [26.5%] vs 82 of 185 [44.3%]; odds ratio [OR], 2.23; 95% confidence interval [CI], 1.39-3.57; P = .0009). The rate of conversion from one procedure to the other was significantly lower in the PTBD group than in the EBD group (8 of 158 [5.0%] vs 73 of 275 [26.5%]; odds ratio, 4.76; 95% CI, 2.71-8.36; P drainage in resectable PHCC. PTBD is associated with less conversion and lower rates of pancreatitis and cholangitis. Copyright © 2017 SIR. Published by Elsevier Inc. All rights reserved.

  19. Composition and fate of mine- and smelter-derived particulates in soils from humid subtropical and semiarid areas

    Science.gov (United States)

    Ettler, Vojtech; Kribek, Bohdan; Mihaljevic, Martin; Vanek, Ales; Penizek, Vit; Sracek, Ondra; Mapani, Ben; Kamona, Fred; Nyambe, Imasiku

    2017-04-01

    Soils in the vicinity of non-ferrous metal smelters are often highly polluted by inorganic contaminants released from particulate emissions, which undergo weathering processes and release contaminants when deposited in soils. We studied the heavy mineral fraction, separated from mining- and smelter-affected topsoils, from both a humid subtropical area in the Zambian Copperbelt and a hot semi-arid area in the northern Namibia. High concentrations of metal(loid)s were detected in the studied soils: up to 1450 ppm As, 8980 ppm Cu, 4640 ppm Pb, 2620 ppm Zn. A combination of X-ray diffraction analysis (XRD), scanning electron microscopy (SEM/EDS), and electron probe microanalysis (EPMA) helped to identify the phases forming individual metal(loid)-bearing particles. Whereas spherical particles originate from the smelting and flue gas cleaning processes, angular particles either have geogenic origins or they are windblown from the mining operations and mine waste disposal sites. Sulphides from ores and mine tailings often exhibit weathering rims in contrast to smelter-derived high-temperature sulphides (chalcocite [Cu2S], digenite [Cu9S5], covellite [CuS], non-stoichiometric quenched Cu-Fe-S phases). Soils from humid subtropical areas exhibit higher available concentrations of metal(loids), and higher frequencies of weathering features (especially for copper-bearing oxides such as delafossite [CuFeO2]) are observed. In contrast, metal(loid)s are efficiently retained in semi-arid soils, where a high proportion of non-weathered smelter slag particles and low-solubility Ca-Cu-Pb arsenates occur. Our results indicate that compared to semi-arid areas (where inorganic contaminants were rather immobile in soils despite their high concentrations) a higher potential risk exists for agriculture in mine- and smelter-affected humid subtropical areas (where metal(loid) contaminants can be highly available for the uptake by crops). This study was supported by the Czech Science

  20. Pollution Assessment of Rice Agriculture in the Taihu Lake Watershed Based on the Pollution Footprint: A Case Study of Changzhou City and Yixing City, China

    Directory of Open Access Journals (Sweden)

    LI Jing

    2014-08-01

    Full Text Available Rice agriculture has been proved to make a great contribution to the food quantity security, but farmers are driven by economic in-terests to overuse the pesticides and chemical fertilizers. The water environment is getting worse and worse. Based on the first national census of pollution data and the production and drainage coefficient of the pollutants, this paper calculated pollutant (COD, TN and TPquantity in-lets into river from rice agriculture. The pollution footprint based on the pollution footprint model and the pressure index of pollution based on the pollution pressure model were also calculated. The results showed that the river discharge of COD and TN took the most part in that of COD, TN and TP. The river discharge of COD, TN and TP was 792.96 t·a-1, 605.28 t·a-1 and 27.16 t·a-1 respectively. The pollution footprint of TN was the largest, which was 3 944.50 hm2, the second was the pollution footprint of TP, which was 2 578.95 hm2, the smallest was the pollution footprint of COD, which was 523.52 hm2. The pollution pressure index of rice agriculture was 2.10, indicating that the river is in a moderate pollution stress condition. So the pollutant river discharge of the rice agriculture is beyond the carrying capacity of the local waters.

  1. Limnological characterisation and phytoplankton seasonal variation in a subtropical shallow lake (Guaiba Lake, Brazil: a long-term study

    Directory of Open Access Journals (Sweden)

    Rodrigo da Rocha Andrade

    2014-12-01

    Full Text Available AIM: to provide a long-term limnological characterisation of a subtropical shallow lake in addition to verifying seasonal differences, including phytoplankton variation. METHODS: monthly sampling at sites IP, SJ and MD from 2000 to 2009 to analyse temperature - T; depth - Z; the depth of the euphotic zone - Zeu; Zeu/Z (%; total suspended solids - TSS; dissolved oxygen - DO; pH; electrical conductivity - EC; N-NH3, N-NO2, N-NO3; soluble reactive phosphorus - SRP; chlorophyll a - Chl-a and phytoplankton. RESULTS: low values of Z and Zeu characterised the shallow and turbid conditions of lake and corresponded to the contribution of nano-microflagellates (Chlamydomonas sp., Spermatozopsis sp., Cryptomonas sp. and Rhodomonas sp and diatoms (Aulacoseira granulata. Zeu/Z (%, SRP and Chl-a were significantly different at site IP (meso-eutrophic compared to sites SJ and MD (eutrophic. Phytoplankton density was also significantly higher at sites SJ and MD, and the largest relative contribution of Actinastrum sp., Dictyosphaerium sp., Micractinium sp., Monoraphidium sp., Scenedesmus/Desmodesmus sp. and Euglena sp. corresponded to the most polluted waters at site SJ. The significantly higher T (ºC in summer corresponded to significantly higher Chl-a as well as a greater richness and density of phytoplankton. Cocconeis sp., Gomphonema sp. and Pinnularia sp. (pennated diatoms were negatively correlated with temperature and were therefore more representative at the three sites in winter. Asterionella formosa was correlated with SRP and vernal blooms were recorded (2000-2001. Planktothrix isothrix and Planktothricoides raciborskii were expressive in the summer/late summer (2004-2005, and were significantly correlated with Chl-a and low SRP in water column. CONCLUSIONS: The study corroborated the sensitivity of phytoplankton in characterising different stages of eutrophication at different sites and corresponding watersheds as well as in characterising

  2. Effect of urbanization on the structure and functional traits of remnant subtropical evergreen broad-leaved forests in South China.

    Science.gov (United States)

    Huang, Liujing; Chen, Hongfeng; Ren, Hai; Wang, Jun; Guo, Qinfeng

    2013-06-01

    We investigated the effects of major environmental drivers associated with urbanization on species diversity and plant functional traits (PFTs) in the remnant subtropical evergreen broad-leaved forests in Metropolitan Guangzhou (Guangdong, China). Twenty environmental factors including topography, light, and soil properties were used to quantify the effects of urbanization. Vegetation data and soil properties were collected from 30 400-m(2) plots at 6 study sites in urban and rural areas. The difference of plant species diversity and PFTs of remnant forests between urban and rural areas were analyzed. To discern the complex relationships, multivariate statistical analyses (e.g., canonical correspondence analysis and regression analysis) were employed. Pioneer species and stress-tolerant species can survive and vigorously establish their population dominance in the urban environment. The native herb diversity was lower in urban forests than in rural forests. Urban forests tend to prefer the species with Mesophanerophyte life form. In contrast, species in rural forests possessed Chamaephyte and Nanophanerophyte life forms and gravity/clonal growth dispersal mode. Soil pH and soil nutrients (K, Na, and TN) were positively related to herb diversity, while soil heavy metal concentrations (Cu) were negatively correlated with herb diversity. The herb plant species diversity declines and the species in the remnant forests usually have stress-tolerant functional traits in response to urbanization. The factors related to urbanization such as soil acidification, nutrient leaching, and heavy metal pollution were important in controlling the plant diversity in the forests along the urban-rural gradients. Urbanization affects the structure and functional traits of remnant subtropical evergreen broad-leaved forests.

  3. Unilobar versus bilobar biliary drainage: effect on quality of life and bilirubin level reduction

    Directory of Open Access Journals (Sweden)

    Shivanand Gamanagatti

    2016-01-01

    Conclusion: Percutaneous biliary drainage provides good palliation of malignant obstructive jaundice. Partial-liver drainage achieved results as good as those after complete liver drainage with significant improvements in QOL and reduction of the bilirubin level.

  4. Kinetics of diuron under aerobic condition and residue analysis in sugarcane under subtropical field conditions.

    Science.gov (United States)

    Tandon, Shishir; Pant, Ravi

    2017-10-10

    The phenylureas group includes persistent herbicides which are major pollutants to soil and water. Dissipation kinetics of diuron in different soils under sugarcane field conditions was investigated. Diuron was extracted with acetone and florisil solid phase extraction clean-up and characterized by high-performance liquid chromatography-UV. Diuron persisted for more than 100 days and dissipation followed monophasic first-order kinetics. Persistence was more in sandy loam compared to silty clay loam soil. Half-life of diuron in silty clay loam soil was 22.57 and 32.37 days and in sandy loam was 28.35 and 43.93 days at 2 and 4 kg ha-1applications, respectively. Average recovery in soil, bagasse, leaf-straw and juice ranged from 75.95% to 84.20%, 80.15% to 89.35%, 77.46% to 86.19% and 81.88% to 92.68%, respectively. The quantitation limits for soil, bagasse, leaf-straw and juice were 0.01, 0.03, 0.04 μg g -1 and 0.008 μg mL -1 , respectively. Application of diuron inhibited growth of soil microbes initially but they recovered later. At harvest, diuron residues were below maximum residue limits in all samples. The study revealed that under subtropical conditions, diuron is safe for use in weed management and would not pose any residual/environmental problem and that sugarcane crop could be used safe for human/animal consumption.

  5. Benthic Diatom Based Indices for Water Quality Assessment in Two Subtropical Streams.

    Science.gov (United States)

    Tan, Xiang; Zhang, Quanfa; Burford, Michele A; Sheldon, Fran; Bunn, Stuart E

    2017-01-01

    Benthic diatoms have been universally used as indicators to assess water quality in lotic ecosystems. However, most diatom-based indices developed in Europe have not been widely used or tested in other continents such as Asia or Oceania. This study compared the performance of 14 widely-applied diatom indices in assessing ecological conditions in subtropical streams in South East Queensland (SEQ) in Australia and in the upper Han River in China. Most water quality variables in the upper Han River including dissolved organic carbon (DOC), total nitrogen (TN), and soluble reactive phosphorus (SRP) had strong relationships with at least one diatom index, with the exception of IDAP (Index Diatom Artois-Picardie), and TDI (Trophic Diatom Index). However, in SEQ, most of the environmental variables including DOC, ammonia nitrogen (NH 4 -N), TN, SRP, and electrical conductivity (EC) showed no significant relationships with diatom indices, and the DI-CH (Swiss Diatom Index) and WAT (Watanabe's Index) were unrelated to any of the variables examined. Only pH and nitrite or nitrate nitrogen (NO X -N) were significant predictors of several diatom indices in SEQ, especially TID (Rott trophic index). In the upper Han River, much of the spatial variation in most diatom indices was explained by proximate determinants alone, including EC, DOC, dissolved oxygen (DO) or SRP, or a combination of ultimate (canopy, forest) and proximate factors ( R 2 in most models> 0.75). Most diatom indices performed as predicted in the upper Han River where nutrient and organic matter pollution was relatively high, and variation in pH low. However, the indices performed poorly in SEQ where the water quality gradient was low and instead most responded to spatial variation in pH. This finding serves as a caution to the application of diatom indices in river basins that fall outside of the range of water quality values of the systems in which they originally developed.

  6. Creating an integrated historical record of extreme particulate air pollution events in Australian cities from 1994 to 2007.

    Science.gov (United States)

    Johnston, Fay H; Hanigan, Ivan C; Henderson, Sarah B; Morgan, Geoffrey G; Portner, Talia; Williamson, Grant J; Bowman, David M J S

    2011-04-01

    Epidemiological studies of exposure to vegetation fire smoke are often limited by the availability of accurate exposure data. This paper describes a systematic framework for retrospectively identifying the cause of air pollution events to facilitate a long, multicenter analysis of the public health effects of vegetation fire smoke pollution in Australia. Pollution events were statistically defined as any day at or above the 95th percentile of the 24-hr average concentration of particulate matter (PM). These were identified for six cities from three distinct ecoclimatic regions of Australia. The dates of each event were then crosschecked against a range of information sources, including online newspaper archives, government and research agency records, satellite imagery, and aerosol optical thickness measures to identify the cause for the excess particulate pollution. Pollution events occurred most frequently during summer for cities in subtropical and arid regions and during winter for cities in temperate regions. A cause for high PM on 67% of days examined in the city of Sydney was found, and 94% of these could be attributed to landscape fire smoke. Results were similar for cities in other subtropical and arid locations. Identification of the cause of pollution events was much lower in colder temperate regions where fire activity is less frequent. Bushfires were the most frequent cause of extreme pollution events in cities located in subtropical and arid regions of Australia. Although identification of pollution episodes was greatly improved by the use of multiple sources of information, satellite imagery was the most useful tool for identifying bushfire smoke pollution events.

  7. Treatment Solutions for Rainwater Contaminated with Various Pollutants

    OpenAIRE

    Adriana Tokar; Arina Negoițescu

    2015-01-01

    This study presents aspects on the environmental pollution with contaminants difficult to manage from sources such as car parking, roads and roofs in crowded areas that have deficient wastewater harvesting urban networks. The contaminants washed by the rainwater that are not collected and treated can reach directly into the natural environment. Thus, rainwater which falls on rough surfaces, especially in car parking and roads without drainage channels carries out various pol...

  8. Pollution of River Spree in Berlin from 1871 to 1914

    OpenAIRE

    Winklhöfer, Karin

    2015-01-01

    Abstract In the late 19th and early 20th century, industrialization and burgeoning town populations in Europe flooded rivers with waste water; rivers with restricted drainage became noticeably polluted. Berlin exemplified these problems and challenges and the kinds of responses and solutions that were brought to bear. Upstream of Köpenick, the Müggelspree could cope with the discharge of several small industrial establishments. The situation at Dahme River was different, however, becaus...

  9. Tile Drainage Expansion Detection using Satellite Soil Moisture Dynamics

    Science.gov (United States)

    Jacobs, J. M.; Cho, E.; Jia, X.

    2017-12-01

    In the past two decades, tile drainage installation has accelerated throughout the Red River of the North Basin (RRB) in parts of western Minnesota, eastern North Dakota, and a small area of northeastern South Dakota, because the flat topography and low-permeability soils in this region necessitated the removal of excess water to improve crop production. Interestingly, streamflow in the Red River has markedly increased and six of 13 major floods during the past century have occurred since the late 1990s. It has been suggested that the increase in RRB flooding could be due to change in agricultural practices, including extensive tile drainage installation. Reliable information on existing and future tile drainage installation is greatly needed to capture the rapid extension of tile drainage systems and to locate tile drainage systems in the north central U.S. including the RRB region. However, there are few reliable data of tile drainage installation records, except tile drainage permit records in the Bois de Sioux watershed (a sub-basin in southern part of the RRB where permits are required for tile drainage installation). This study presents a tile drainage expansion detection method based on a physical principle that the soil-drying rate may increase with increasing tile drainage for a given area. In order to capture the rate of change in soil drying rate with time over entire RRB (101,500 km2), two satellite-based microwave soil moisture records from the Advanced Microwave Scanning Radiometer for Earth Observing System (AMSR-E) and AMSR2 were used during 2002 to 2016. In this study, a sub-watershed level (HUC10) potential tile drainage growth map was developed and the results show good agreement with tile drainage permit records of six sub-watersheds in the Bois de Sioux watershed. Future analyses will include improvement of the potential tile drainage map through additional information using optical- and thermal-based sensor products and evaluation of its

  10. Dissemination of regional rainfall analysis in design and analysis of urban drainage at un-gauged locations

    DEFF Research Database (Denmark)

    Arnbjerg-Nielsen, K.; Harremoes, Poul; Mikkelsen, Peter Steen

    2002-01-01

    A research program in Denmark on statistical modelling of rainfall has resulted in a model for regional distribution of rainfall extremes. The results show that extreme rainfalls critical to the hydraulic function of urban drainage systems and the pollution discharge are subject to a significant...... regional variation of extreme rainfalls throughout the country. This has implications for design and analysis of all practical problems related to urban drainage, since the rainfall data so far recommended as input to engineering analyses underestimates the problems. Consequently, the Danish Water......-friendly spreadsheets and easy access to rainfall data as well as giving courses on the new paradigm. This has eased the implementation of the new concepts greatly....

  11. Concepts of Urban Drainage and Flood Protection

    DEFF Research Database (Denmark)

    Harremoës, Poul

    1990-01-01

    The significance of the introduction of modern computer technology to design, analysis, operation and control of sewer systems during rain is analyzed. With new tools come new basic concepts and new engineering criteria for performance. The most significant developments are: the capability to cal...... in real time in order to decrease the pollutional load by optimization of the usage of storage at rains smaller than the design rain, without increasing the risk of floods....

  12. USCG Vessel Pollution

    Data.gov (United States)

    Department of Homeland Security — The Marine Casualty and Pollution Data files provide details about marine casualty and pollution incidents investigated by Coast Guard Offices throughout the United...

  13. USCG Facility Pollution

    Data.gov (United States)

    Department of Homeland Security — The Marine Casualty and Pollution Data files provide details about marine casualty and pollution incidents investigated by Coast Guard Offices throughout the United...

  14. Implantation of a second glaucoma drainage device.

    Science.gov (United States)

    Francis, Brian A; Fernandes, Rodrigo A B; Akil, Handan; Chopra, Vikas; Diniz, Bruno; Tan, James; Huang, Alex

    2017-05-01

    To evaluate success rates in controlling intraocular pressure (IOP) after implantation of a second glaucoma drainage device (GDD) with a Baerveldt glaucoma implant in patients with refractory glaucoma, with a secondary aim of reducing the need for postoperative glaucoma medications. This retrospective, noncomparative, interventional study included patients undergoing a second GDD for uncontrolled glaucoma from a tertiary care glaucoma service. Data were obtained from the medical records for the preoperative period and after the 1st, 15th, and 30th day, 3, 6, and 12 months, and then yearly until the last postoperative visit. Visual acuity, IOP, and number of glaucoma medications (NGM) from the follow-up visits were compared to baseline. Success and failure criteria were analyzed based on IOP level or need of glaucoma medications. Forty-nine patients were studied, with a mean follow-up time of 25 ± 21 months. The mean preoperative IOP was 23.7 ± 8.2 mmHg, and decreased to 14.8 ± 4.0 mmHg after 1 year, 14.4 ± 3.9 mmHg after 2 years, and 16.6 ± 8.5 mmHg after 3 years. The mean preoperative NGM was 3.4 ± 1.3, and decreased to 2.0 ± 1.8 after 1 year, 2.5 ± 1.6 after 2 years, and 2.8 ± 2.0 after 3 years. Absolute success was 9% after 1 year for a postoperative IOP between 5 and 18 mmHg, and 76% for a postoperative IOP between 5 and 21 mmHg. The qualified success was 88% at the first and second years and 83% at the third year. With up to 3 years of follow-up, a second glaucoma drainage device was successful in reducing IOP to below 21 mmHg, but not as successful below 18 mmHg. The success rate is improved with the use of glaucoma medications with up to 3 years of follow-up.

  15. Copper isotope fractionation in acid mine drainage

    Science.gov (United States)

    Kimball, B.E.; Mathur, R.; Dohnalkova, A.C.; Wall, A.J.; Runkel, R.L.; Brantley, S.L.

    2009-01-01

    We measured the Cu isotopic composition of primary minerals and stream water affected by acid mine drainage in a mineralized watershed (Colorado, USA). The ??65Cu values (based on 65Cu/63Cu) of enargite (??65Cu = -0.01 ?? 0.10???; 2??) and chalcopyrite (??65Cu = 0.16 ?? 0.10???) are within the range of reported values for terrestrial primary Cu sulfides (-1??? waters (1.38??? ??? ??65Cu ??? 1.69???). The average isotopic fractionation (??aq-min = ??65Cuaq - ??65Cumin, where the latter is measured on mineral samples from the field system), equals 1.43 ?? 0.14??? and 1.60 ?? 0.14??? for chalcopyrite and enargite, respectively. To interpret this field survey, we leached chalcopyrite and enargite in batch experiments and found that, as in the field, the leachate is enriched in 65Cu relative to chalcopyrite (1.37 ?? 0.14???) and enargite (0.98 ?? 0.14???) when microorganisms are absent. Leaching of minerals in the presence of Acidithiobacillus ferrooxidans results in smaller average fractionation in the opposite direction for chalcopyrite (??aq-mino = - 0.57 ?? 0.14 ???, where mino refers to the starting mineral) and no apparent fractionation for enargite (??aq-mino = 0.14 ?? 0.14 ???). Abiotic fractionation is attributed to preferential oxidation of 65Cu+ at the interface of the isotopically homogeneous mineral and the surface oxidized layer, followed by solubilization. When microorganisms are present, the abiotic fractionation is most likely not seen due to preferential association of 65Cuaq with A. ferrooxidans cells and related precipitates. In the biotic experiments, Cu was observed under TEM to occur in precipitates around bacteria and in intracellular polyphosphate granules. Thus, the values of ??65Cu in the field and laboratory systems are presumably determined by the balance of Cu released abiotically and Cu that interacts with cells and related precipitates. Such isotopic signatures resulting from Cu sulfide dissolution should be useful for acid mine drainage

  16. Thoracoscopic Surgery for Pneumothorax Following Outpatient Drainage Therapy.

    Science.gov (United States)

    Sano, Atsushi; Yotsumoto, Takuma

    2017-10-20

    We investigated the outcomes of surgery for pneumothorax following outpatient drainage therapy. We reviewed the records of 34 patients who underwent operations following outpatient drainage therapy with the Thoracic Vent at our hospital between December 2012 and September 2016. Indications for outpatient drainage therapy were pneumothorax without circulatory or respiratory failure and pleural effusion. Indications for surgical treatment were persistent air leakage and patient preference for surgery to prevent or reduce the incidence of recurrent pneumothorax. Intraoperatively, 9 of 34 cases showed loose adhesions around the Thoracic Vent, all of which were dissected bluntly. The preoperative drainage duration ranged from 5 to 13 days in patients with adhesions and from 3 to 19 days in those without adhesions, indicating no significant difference. The duration of preoperative drainage did not affect the incidence of adhesions. The operative duration ranged from 30 to 96 minutes in patients with adhesions and from 31 to 139 minutes in those without adhesions, also indicating no significant difference. Outpatient drainage therapy with the Thoracic Vent was useful for spontaneous pneumothorax patients who underwent surgery, and drainage for less than 3 weeks did not affect intraoperative or postoperative outcomes.

  17. Systematic review comparing endoscopic, percutaneous and surgical pancreatic pseudocyst drainage

    Science.gov (United States)

    Teoh, Anthony Yuen Bun; Dhir, Vinay; Jin, Zhen-Dong; Kida, Mitsuhiro; Seo, Dong Wan; Ho, Khek Yu

    2016-01-01

    AIM: To perform a systematic review comparing the outcomes of endoscopic, percutaneous and surgical pancreatic pseudocyst drainage. METHODS: Comparative studies published between January 1980 and May 2014 were identified on PubMed, Embase and the Cochrane controlled trials register and assessed for suitability of inclusion. The primary outcome was the treatment success rate. Secondary outcomes included were the recurrence rates, re-interventions, length of hospital stay, adverse events and mortalities. RESULTS: Ten comparative studies were identified and 3 were randomized controlled trials. Four studies reported on the outcomes of percutaneous and surgical drainage. Based on a large-scale national study, surgical drainage appeared to reduce mortality and adverse events rate as compared to the percutaneous approach. Three studies reported on the outcomes of endoscopic ultrasound (EUS) and surgical drainage. Clinical success and adverse events rates appeared to be comparable but the EUS approach reduced hospital stay, cost and improved quality of life. Three other studies compared EUS and esophagogastroduodenoscopy-guided drainage. Both approaches were feasible for pseudocyst drainage but the success rate of the EUS approach was better for non-bulging cyst and the approach conferred additional safety benefits. CONCLUSION: In patients with unfavorable anatomy, surgical cystojejunostomy or percutaneous drainage could be considered. Large randomized studies with current definitions of pseudocysts and longer-term follow-up are needed to assess the efficacy of the various modalities. PMID:27014427

  18. The Role of Subtropical Intrusion in the Development of Typhoon Usagi (5W) 2007

    National Research Council Canada - National Science Library

    DeLeon, Raymund P

    2008-01-01

    ... of a decaying baroclinic system in the WNP. This analysis of the formation of Usagi points to sub-tropical intrusion of a strong lower-tropospheric baroclinic system undergoing decay as potential seedlings for typhoon formation in areas...

  19. Grasslands feeling the heat: The effects of elevated temperatures on a subtropical grassland

    Directory of Open Access Journals (Sweden)

    Rowan D. Buhrmann

    2016-12-01

    Conclusions: OTCs can simulate realistic increases of air temperature in subtropical grasslands. Graminoids and shrubs appear to benefit from elevated temperatures whilst forbs decrease in abundance, possibly through competition and/or direct physiological effects.

  20. An observational study of the carbon-sink strength of East Asian subtropical evergreen forests

    International Nuclear Information System (INIS)

    Tan Zhenghong; Zhang Yiping; Zhang Yongjiang; Song Qinhai; Cao Kunfang; Schaefer, D A; Liu Yuhong; Liang Naishen; Hsia, Yue-Joe; Zhou Guoyi; Li Yuelin; Yan Junhua; Juang, Jehn-Yih; Chu Housen; Yu Guirui; Sun Xiaomin

    2012-01-01

    Relatively little is known about the effects of regional warming on the carbon cycle of subtropical evergreen forest ecosystems, which are characterized by year-round growing season and cold winters. We investigated the carbon balance in three typical East Asia subtropical evergreen forests, using eddy flux, soil respiration and leaf-level measurements. Subtropical evergreen forests maintain continuous, high rates of photosynthetic activity, even during winter cold periods. Warm summers enhance photosynthetic rates in a limited way, because overall ecosystem productivity is primarily restrained by radiation levels during the warm period. Conversely, warm climates significantly enhance the respiratory carbon efflux. The finding of lower sensitivity of photosynthesis relative to that of respiration suggests that increased temperature will weaken the carbon-sink strength of East Asia subtropical evergreen forests. (letter)

  1. Sub-tropical urban environment affecting content and composition of non-structural carbohydrates of Lolium multiflorum ssp. italicum cv. Lema

    Energy Technology Data Exchange (ETDEWEB)

    Sandrin, Carla Zuliani; Figueiredo-Ribeiro, Rita de Cassia Leone; Carvalho, Maria Angela Machado de [Instituto de Botanica, Caixa Postal 3005, 01061-970 Sao Paulo, SP (Brazil); Carvalho Delitti, Welington Braz [Instituto de Biociencias, Universidade de Sao Paulo, Departamento de Ecologia, Caixa Postal 11461, 05422-970 Sao Paulo, SP (Brazil); Domingos, Marisa [Instituto de Botanica, Caixa Postal 3005, 01061-970 Sao Paulo, SP (Brazil)], E-mail: mmingos@superig.com.br

    2008-12-15

    This study analyzed the relationship between environmental factors, especially air pollution and climatic conditions, and non-structural carbohydrates (NSC) in plants of Lolium multiflorum exposed during 10 consecutive periods of 28 days at a polluted site (Congonhas) and at a reference site in Sao Paulo city (Brazil). After exposure, NSC composition and leaf concentrations of Al, Fe, Cu, Zn, Pb and Cd were measured. The seasonal pattern of NSC accumulation was quite similar in both sites, but plants at Congonhas showed higher concentrations of these compounds, especially fructans of low and medium degree of polymerization. Regression analysis showed that NSC in plants growing at the polluted site were explained by variations on temperature and leaf concentration of Fe (positive effect), as well as relative humidity and particulate material (negative effect). NSC in the standardized grass culture, in addition to heavy metal accumulation, may indicate stressing conditions in a sub-tropical polluted environment. - Particulate matter and air temperature increased non-structural carbohydrates in the standardized biomonitor grass in Sao Paulo.

  2. Sub-tropical urban environment affecting content and composition of non-structural carbohydrates of Lolium multiflorum ssp. italicum cv. Lema

    International Nuclear Information System (INIS)

    Sandrin, Carla Zuliani; Figueiredo-Ribeiro, Rita de Cassia Leone; Carvalho, Maria Angela Machado de; Carvalho Delitti, Welington Braz; Domingos, Marisa

    2008-01-01

    This study analyzed the relationship between environmental factors, especially air pollution and climatic conditions, and non-structural carbohydrates (NSC) in plants of Lolium multiflorum exposed during 10 consecutive periods of 28 days at a polluted site (Congonhas) and at a reference site in Sao Paulo city (Brazil). After exposure, NSC composition and leaf concentrations of Al, Fe, Cu, Zn, Pb and Cd were measured. The seasonal pattern of NSC accumulation was quite similar in both sites, but plants at Congonhas showed higher concentrations of these compounds, especially fructans of low and medium degree of polymerization. Regression analysis showed that NSC in plants growing at the polluted site were explained by variations on temperature and leaf concentration of Fe (positive effect), as well as relative humidity and particulate material (negative effect). NSC in the standardized grass culture, in addition to heavy metal accumulation, may indicate stressing conditions in a sub-tropical polluted environment. - Particulate matter and air temperature increased non-structural carbohydrates in the standardized biomonitor grass in Sao Paulo

  3. Superficial drainage studies in open-pit mines

    International Nuclear Information System (INIS)

    Teixeira Junior, P.B.; Leite, C.B.B.

    1984-01-01

    Drainage studies concerning large open-pit mining projects can be of vital importance throughout the mining activity itself as they may assist in avoiding activity interruptions due to drainage problems, therefore representing substantial savings. These studies should, in fact, be carried out from the initial activity stages and shall be considered in operational, project and planning decisions in order to optimize results and reduce costs. This specific study presents a drainage study systematization proposal, enphasazing economic decision criteria. The authors comment on studies of this nature developed at the Caldas uranium mine - NUCLEBRAS. (D.J.M.) [pt

  4. Vacuum-assisted drainage in cardiopulmonary bypass: advantages and disadvantages.

    Science.gov (United States)

    Carvalho Filho, Elio Barreto de; Marson, Fernando Augusto de Lima; Costa, Loredana Nilkenes Gomes da; Antunes, Nilson

    2014-01-01

    Systematic review of vacuum assisted drainage in cardiopulmonary bypass, demonstrating its advantages and disadvantages, by case reports and evidence about its effects on microcirculation. We conducted a systematic search on the period 1997-2012, in the databases PubMed, Medline, Lilacs and SciELO. Of the 70 selected articles, 26 were included in the review. Although the vacuum assisted drainage has significant potential for complications and requires appropriate technology and professionalism, prevailed in literature reviewed the concept that vacuum assisted drainage contributed in reducing the rate of transfusions, hemodilutions, better operative field, no significant increase in hemolysis, reduced complications surgical, use of lower prime and of smaller diameter cannulas.

  5. Functional Topology of Evolving Urban Drainage Networks

    Science.gov (United States)

    Yang, Soohyun; Paik, Kyungrock; McGrath, Gavan S.; Urich, Christian; Krueger, Elisabeth; Kumar, Praveen; Rao, P. Suresh C.

    2017-11-01

    We investigated the scaling and topology of engineered urban drainage networks (UDNs) in two cities, and further examined UDN evolution over decades. UDN scaling was analyzed using two power law scaling characteristics widely employed for river networks: (1) Hack's law of length (L)-area (A) [L∝Ah] and (2) exceedance probability distribution of upstream contributing area (δ) [P>(A≥δ>)˜aδ-ɛ]. For the smallest UDNs ((A≥δ>) plots for river networks are abruptly truncated, those for UDNs display exponential tempering [P>(A≥δ>)=aδ-ɛexp⁡>(-cδ>)]. The tempering parameter c decreases as the UDNs grow, implying that the distribution evolves in time to resemble those for river networks. However, the power law exponent ɛ for large UDNs tends to be greater than the range reported for river networks. Differences in generative processes and engineering design constraints contribute to observed differences in the evolution of UDNs and river networks, including subnet heterogeneity and nonrandom branching.

  6. Prognostic factors after percutaneous transhepatic biliary drainage

    International Nuclear Information System (INIS)

    Castoldi, M.C.; Cozzi, G.; Severini, A.; Pisani, P.; Ideo, G.; Bellomi, M.

    1991-01-01

    The authors reviewed the clinical charts and the radiographic files of 93 patients with obsructive jaundice -in 86 cases due to neoplasms -treated with PTBD. The test of differences from survival curves was used to identify the clinical parameters predictive of short survival after PTBD. The difference in survival curves was significant relative to serum indirect bilirubin (cut point: 7.6 mg%), to serum cholinesterase (cut point: 1290 mU/ml), to white blood cells counts (cut point: 8600/mm 3 ), to blood urea nitrogen (BUN) levels (cut point: 60 mg%). Because of the market negative prognostic value of high BUN levels, our data seemto indicate that PTBD should not be performed when severe renal insufficiency is present. Other parameters correlated with a short survival after PTBD were the histotype of metastasis (in comparison with the other ones) and in large neoplastic volume (in comparison with a small and medium ones). Through pre-PTBD radiological and laboratory data analysis, a group of patients can be selected in whom the procedure will increase neither well-being nor survival, as plotted against those patients who are likely to benefit from biliary drainage

  7. Lignor process for acidic rock drainage treatment.

    Science.gov (United States)

    Zhuang, J M; Walsh, T

    2004-09-01

    The process using lignosulfonates for acidic rock drainage (ARD) treatment is referred to as the Lignor process. Lignosulfonates are waste by-products produced in the sulfite pulping process. The present study has shown lignosulfonates are able to protect lime from developing an external surface coating, and hence to favor its dissociation. Further, the addition of lignosulfonates to ARD solutions increased the dotting and settling rate of the formed sludge. The capability of lignosulfonates to form stable metal-lignin complexes makes them very useful in retaining metal ions and thus improving the long-term stability of the sludge against leaching. The Lignor process involves metal sorption with lignosulfonates, ARD neutralization by lime to about pH 7, pH adjustment with caustic soda to 9.4 - 9.6, air oxidation to lower the pH to a desired level, and addition of a minimum amount of FeCl3 for further removal of dissolved metals. The Lignor process removes all concerned metals (especially Al and Mn) from the ARD of the Britannia Mine (located at Britannia Beach, British Columbia, Canada) to a level lower than the limits of the B.C. Regulations. Compared with the high-density sludge (HDS) process, the Lignor process has many advantages, such as considerable savings in lime consumption, greatly reduced sludge volume, and improved sludge stability.

  8. Inertial gravity currents from edge drainage

    Science.gov (United States)

    Momen, Mostafa; Zheng, Zhong; Bou-Zeid, Elie; Stone, Howard

    2017-11-01

    Gravity currents are formed due to a density gradient in the horizontal direction between the current and an ambient fluid. In this work, we present theoretical, numerical, and experimental studies of the release of a finite volume of fluid instantaneously from the edge of a rectangular domain for high-Reynolds-number flows. The setup is relevant in geophysical and engineering applications such as open channels, and dam-break problems. For the cases we considered, the results indicate that about half of the initial volume exits during an early adjustment period. Then, the inertial gravity current reaches a self-similar phase during which about 40% of its volume drains and its height decreases as τ-2, where τ is a dimensionless time that is derived with the typical gravity wave speed and the horizontal length of the domain. Based on scaling arguments, we reduce the shallow-water PDEs into two nonlinear ODEs, which are then solved analytically. The new self-similar solutions are in good agreement with the performed experiments and direct numerical simulations for various geometries and fluid densities. This study provides new insights into the dynamical behavior of edge drainage flows, particularly during the inertial regime. The simulations were performed on the Della computer clusters of Princeton University.

  9. Long hole waterjet drilling for gas drainage

    Energy Technology Data Exchange (ETDEWEB)

    Matt Stockwell; M. Gledhill; S. Hildebrand; S. Adam; Tim Meyer [CMTE (Australia)

    2003-04-01

    In-seam drilling for gas drainage is now an essential part of operations at many Australian underground coalmines. The objective of this project is to develop and trial a new drilling method for the accurate and efficient installation of long inseam boreholes (>1000 metres). This involves the integration of pure water-jet drilling technology (i.e. not water-jet assisted rotary drilling) developed by CMTE with conventional directional drilling technology. The system was similar to conventional directional drilling methods, but instead of relying on a down-hole-motor (DHM) rotating a mechanical drill bit for cutting, high pressure water-jets were used. The testing of the system did not achieve the full objectives set down in the project plan. A borehole greater than 1000 metres was not achieved. The first trial site had coal that was weathered, oxidized and dry. These conditions significantly affected the ability of the drilling tool to stay 'in-seam'. Due to the poor conditions at the first trial, many experimental objectives were forwarded to the second field trial. In the second trial drilling difficulties were experienced, this was due to the interaction between the confinement of the borehole and the dimensions of the down hole drilling assembly. This ultimately reduced the productivity of the system and the distance that could be drilled within the specified trial periods. Testing in the first field trial did not show any indication that the system would have this difficulty.

  10. Benthic Communities of Low-Order Streams Affected by Acid Mine Drainages: A Case Study from Central Europe

    Directory of Open Access Journals (Sweden)

    Marek Svitok

    2014-05-01

    Full Text Available Only little attention has been paid to the impact of acid mine drainages (AMD on aquatic ecosystems in Central Europe. In this study, we investigate the physico-chemical properties of low-order streams and the response of benthic invertebrates to AMD pollution in the Banská Štiavnica mining region (Slovakia. The studied streams showed typical signs of mine drainage pollution: higher conductivity, elevated iron, aluminum, zinc and copper loads and accumulations of ferric precipitates. Electric conductivity correlated strongly with most of the investigated elements (weighted mean absolute correlation = 0.95 and, therefore, can be recommended as a good proxy indicator for rapid AMD pollution assessments. The diversity and composition of invertebrate assemblages was related to water chemistry. Taxa richness decreased significantly along an AMD-intensity gradient. While moderately affected sites supported relatively rich assemblages, the harshest environmental conditions (pH < 2.5 were typical for the presence of a limited number of very tolerant taxa, such as Oligochaeta and some Diptera (Limnophyes, Forcipomyiinae. The trophic guild structure correlated significantly with AMD chemistry, whereby predators completely disappeared under the most severe AMD conditions. We also provide a brief review of the AMD literature and outline the needs for future detailed studies involving functional descriptors of the impact of AMD on aquatic ecosystems.

  11. Microbiome of Trichodesmium Colonies from the North Pacific Subtropical Gyre

    Directory of Open Access Journals (Sweden)

    Mary R. Gradoville

    2017-07-01

    Full Text Available Filamentous diazotrophic Cyanobacteria of the genus Trichodesmium, often found in colonial form, provide an important source of new nitrogen to tropical and subtropical marine ecosystems. Colonies are composed of several clades of Trichodesmium in association with a diverse community of bacterial and eukaryotic epibionts. We used high-throughput 16S rRNA and nifH gene sequencing, carbon (C and dinitrogen (N2 fixation assays, and metagenomics to describe the diversity and functional potential of the microbiome associated with Trichodesmium colonies collected from the North Pacific Subtropical Gyre (NPSG. The 16S rRNA and nifH gene sequences from hand-picked colonies were predominantly (>99% from Trichodesmium Clade I (i.e., T. thiebautii, which is phylogenetically and ecologically distinct from the Clade III IMS101 isolate used in most laboratory studies. The bacterial epibiont communities were dominated by Bacteroidetes, Alphaproteobacteria, and Gammaproteobacteria, including several taxa with a known preference for surface attachment, and were relatively depleted in the unicellular Cyanobacteria and small photoheterotrophic bacteria that dominate NPSG surface waters. Sequencing the nifH gene (encoding a subcomponent of the nitrogenase enzyme identified non-Trichodesmium diazotrophs that clustered predominantly among the Cluster III nifH sequence-types that includes putative anaerobic diazotrophs. Trichodesmium colonies may represent an important habitat for these Cluster III diazotrophs, which were relatively rare in the surrounding seawater. Sequence analyses of nifH gene transcripts revealed several cyanobacterial groups, including heterocystous Richelia, associated with the colonies. Both the 16S rRNA and nifH datasets indicated strong differences between Trichodesmium epibionts and picoplankton in the surrounding seawater, and also between the epibionts inhabiting Trichodesmium puff and tuft colony morphologies. Metagenomic and 16S r

  12. Influenza-associated hospitalization in a subtropical city.

    Directory of Open Access Journals (Sweden)

    Chit Ming Wong

    2006-04-01

    Full Text Available The impact of influenza on morbidity and hospitalization in the tropics and subtropics is poorly quantified. Uniquely, the Hong Kong Special Administrative Region has computerized hospital discharge diagnoses on 95% of total bed days, allowing disease burden for a well-defined population to be accurately assessed.Influenza-associated morbidity and hospitalization was assessed by Poisson regression models for weekly counts of hospitalizations in Hong Kong during 1996 to 2000, using proportions of positive influenza types A (H1N1 and H3N2 and B isolations in specimens sent for laboratory diagnosis as measures of influenza virus circulation. We adjusted for annual trend, seasonality, temperature, and relative humidity, as well as respiratory syncytial virus circulation. We found that influenza was significantly associated with hospitalization for acute respiratory disease (International Classification of Diseases version 9 codes [ICD9] 460-466 and 480-487 and its subcategory pneumonia and influenza (ICD9 480-487 for all age groups. The annual rates of excess hospitalization per 100,000 population for acute respiratory diseases for the age groups 0-14, 15-39, 40-64, 65-74, and 75+ were 163.3 (95% confidence interval [CI], 135-190, 6.0 (95% CI, 2.7-8.9, 14.9 (95% CI, 10.7-18.8, 83.8 (95% CI, 61.2-104.2, and 266 (95% CI, 198.7-330.2, respectively. Influenza was also associated with hospitalization for cerebrovascular disease (ICD9 430-438 for those aged over 75 y (55.4; 95% CI, 23.1-87.8; ischemic heart disease (ICD9 410-414 for the age group 40-64 y (5.3; 95% CI, 0.5-9.5 and over 75 y (56.4; 95% CI, 21.1-93.4; and diabetes mellitus (ICD9 250 for all age groups older than 40 y.Influenza has a major impact on hospitalization due to cardio-respiratory diseases as well as on cerebrovascular disease, ischemic heart disease, and diabetes mellitus in the tropics and subtropics. Better utilization of influenza vaccine during annual epidemics in the tropics

  13. Spatial and temporal patterns of eastern Australia subtropical coral communities.

    Directory of Open Access Journals (Sweden)

    Steven J Dalton

    Full Text Available Despite increases in the frequency and intensity of disturbances on coral reefs over the past few decades, the response of subtropical coral assemblages to climate change is poorly understood. To address this knowledge gap on Australian reefs and provide a baseline for future comparisons, we quantified spatial (10-100's of kilometres and temporal (decadal patterns of benthic assemblages across a latitudinal gradient along the east Australian coastline (23.5° S to 31.5° S. Benthic community composition was quantified at six locations from the southern Great Barrier Reef, Queensland (Heron Reef, 23.5° S, 152° E to northern New South Wales (31° S, 153.1° E and at Lord Howe Island (31.5° S, 159.1° E. Our results indicate significant latitudinal differences in benthic assemblages, while community composition at some sites was more similar to those hundreds of kilometres away than to that of neighbouring reefs. A general trend was observed with decreasing cover of Acroporidae with increasing latitude, corresponding with an increasing cover of Pocilloporidae and Dendrophylliidae. Heron Reef comprised a high proportion of Acropora corals (43% total coral cover and coralline algae (44%. In contrast, high-latitude reefs were dominated by mixed coral assemblages (0-52% and high macroalgal cover (16-27%. Decadal comparisons of high-latitude reefs showed regional stability of benthic assemblages (9 out of 11 assemblages remained stable at > 75% similarity, during a period of warming oceans (0.15-0.24°C per decade. Such temporal stability suggests that eastern Australian subtropical communities may be more resistant than tropical reef communities that have experienced assembly shifts caused by perturbations associated with recent global climate change. Despite the clear differences in the structure of coral assemblages evident in our spatial surveys, we suggest that the temporal stability of high-latitude reefs may provide a limited refuge for

  14. Heterotrophic respiration does not acclimate to continuous warming in a subtropical forest

    OpenAIRE

    Wu, Chuansheng; Liang, Naishen; Sha, Liqing; Xu, Xingliang; Zhang, Yiping; Lu, Huazheng; Song, Liang; Song, Qinghai; Xie, Youneng

    2016-01-01

    As heterotrophic respiration (R H) has great potential to increase atmospheric CO2 concentrations, it is important to understand warming effects on R H for a better prediction of carbon?climate feedbacks. However, it remains unclear how R H responds to warming in subtropical forests. Here, we carried out trenching alone and trenching with warming treatments to test the climate warming effect on R H in a subtropical forest in southwestern China. During the measurement period, warming increased...

  15. Bibliography for acid-rock drainage and selected acid-mine drainage issues related to acid-rock drainage from transportation activities

    Science.gov (United States)

    Bradley, Michael W.; Worland, Scott C.

    2015-01-01

    Acid-rock drainage occurs through the interaction of rainfall on pyrite-bearing formations. When pyrite (FeS2) is exposed to oxygen and water in mine workings or roadcuts, the mineral decomposes and sulfur may react to form sulfuric acid, which often results in environmental problems and potential damage to the transportation infrastructure. The accelerated oxidation of pyrite and other sulfidic minerals generates low pH water with potentially high concentrations of trace metals. Much attention has been given to contamination arising from acid mine drainage, but studies related to acid-rock drainage from road construction are relatively limited. The U.S. Geological Survey, in cooperation with the Tennessee Department of Transportation, is conducting an investigation to evaluate the occurrence and processes controlling acid-rock drainage and contaminant transport from roadcuts in Tennessee. The basic components of acid-rock drainage resulting from transportation activities are described and a bibliography, organized by relevant categories (remediation, geochemical, microbial, biological impact, and secondary mineralization) is presented.

  16. High carbon dioxide uptake by subtropical forest ecosystems in the East Asian monsoon region

    Science.gov (United States)

    Yu, Guirui; Chen, Zhi; Piao, Shilong; Peng, Changhui; Ciais, Philippe; Wang, Qiufeng; Li, Xuanran; Zhu, Xianjin

    2014-01-01

    Temperate- and high-latitude forests have been shown to contribute a carbon sink in the Northern Hemisphere, but fewer studies have addressed the carbon balance of the subtropical forests. In the present study, we integrated eddy covariance observations established in the 1990s and 2000s to show that East Asian monsoon subtropical forests between 20°N and 40°N represent an average net ecosystem productivity (NEP) of 362 ± 39 g C m−2 yr−1 (mean ± 1 SE). This average forest NEP value is higher than that of Asian tropical and temperate forests and is also higher than that of forests at the same latitudes in Europe–Africa and North America. East Asian monsoon subtropical forests have comparable NEP to that of subtropical forests of the southeastern United States and intensively managed Western European forests. The total NEP of East Asian monsoon subtropical forests was estimated to be 0.72 ± 0.08 Pg C yr−1, which accounts for 8% of the global forest NEP. This result indicates that the role of subtropical forests in the current global carbon cycle cannot be ignored and that the regional distributions of the Northern Hemisphere's terrestrial carbon sinks are needed to be reevaluated. The young stand ages and high nitrogen deposition, coupled with sufficient and synchronous water and heat availability, may be the primary reasons for the high NEP of this region, and further studies are needed to quantify the contribution of each underlying factor. PMID:24639529

  17. Drainage filter technologies to mitigate site-specific phosphorus losses in agricultural drainage discharge

    DEFF Research Database (Denmark)

    Kjærgaard, Charlotte; Heckrath, Goswin Johann; Canga, Eriona

    Losses of phosphorus (P) in drainage waters contribute an estimated 33% to the total agricultural P load in Denmark. Mitigating agricultural P losses is challenging, as critical P losses comprise only a very small fraction of actual soil P contents and are not directly related to fertilizer P input...... filters and constructed wetlands (CWs). Various natural and industrial P filter substrates (granulated Fe-oxides, crushed seashells, Filtralite-PTM, granulated lime, calcined diatomitic earth) have been tested for their affinity and long-term capacity to reduce inlet P concentrations to below...

  18. Rice agriculture impacts catchment hydrographic patterns and nitrogen export characteristics in subtropical central China: a paired-catchment study.

    Science.gov (United States)

    Wang, Yi; Liu, Xinliang; Wang, Hua; Li, Yong; Li, Yuyuan; Liu, Feng; Xiao, Runlin; Shen, Jianlin; Wu, Jinshui

    2017-06-01

    Increased nitrogen (N) concentrations in water bodies have highlighted issues regarding nutrient pollution in agricultural catchments. In this study, the ammonium-N (NH 4 + -N), nitrate-N (NO 3 - -N), and total N (TN) concentrations were observed in the stream water and groundwater of two contrasting catchments (named Tuojia and Jianshan) in subtropical central China from 2010 to 2014, to determine the rice agriculture impacts on the hydrographic patterns, and N export characteristics of the catchments. The results suggested that greater amounts of stream flow (523.0 vs. 434.7 mm year -1 ) and base flow (237.6 vs. 142.8 mm year -1 ) were produced in Tuojia than in Jianshan, and a greater base flow contribution to stream flow and higher frequencies of high-base flow days were observed during the fallow season than during the rice-growing season, indicating that intensive rice agriculture strongly influences the catchment hydrographic pattern. Rice agriculture resulted in moderate N pollution in the stream water and groundwater, particularly in Tuojia. Primarily, rice agriculture increased the NH 4 + -N concentration in the stream water; however, it increased the NO 3 - -N concentrations in the groundwater, suggesting that the different N species in the paddy fields migrated out of the catchments through distinct hydrological pathways. The average TN loading via stream flow and base flow was greater in Tuojia than in Jianshan (1.72 and 0.58 vs. 0.72 and 0.15 kg N ha -1  month -1 , respectively). Greater TN loading via stream flow was observed during the fallow season in Tuojia and during the rice-growing season in Jianshan, and these different results were most likely a result of the higher base flow contribution to TN loading (33.5 vs. 21.3%) and greater base flow enrichment ratio (1.062 vs. 0.876) in Tuojia than in Jianshan. Therefore, the impact of rice agriculture on catchment eco-hydrological processes should be considered when performing water quality

  19. Pollution management system

    DEFF Research Database (Denmark)

    2015-01-01

    A pollution management system comprises an array of one or more inlets and at least one outlet. The one or more inlets are arranged to collect polluted air and supply said polluted air to a polluted air treatment element. The one or more inlets each comprise a respective inlet sensor for measuring...

  20. Arctic vegetation damage by winter-generated coal mining pollution released upon thawing

    DEFF Research Database (Denmark)

    Elberling, B.; Søndergaard, J.; Jensen, L.A.

    2007-01-01

    Acid mine drainage (known as AMD) is a well-known environmental problem resulting from the oxidation of sulfidic mine waste. In cold regions, AMD is often considered limited by low temperatures most of the year and observed environmental impact is related to pollution generated during the warm...

  1. Unsynchronized influenza epidemics in two neighboring subtropical cities

    Directory of Open Access Journals (Sweden)

    Xiujuan Tang

    2018-04-01

    Full Text Available Objective: The aim of this study was to examine the synchrony of influenza epidemics between Hong Kong and Shenzhen, two neighboring subtropical cities in South China. Methods: Laboratory-confirmed influenza data for the period January 2006 to December 2016 were obtained from the Shenzhen Center for Disease Control and Prevention and the Department of Health in Hong Kong. The population data were retrieved from the 2011 population censuses. The weekly rates of laboratory-confirmed influenza cases were compared between Shenzhen and Hong Kong. Results: Unsynchronized influenza epidemics between Hong Kong and Shenzhen were frequently observed during the study period. Influenza A/H1N1 caused a more severe pandemic in Hong Kong in 2009, but the subsequent seasonal epidemics showed similar magnitudes in both cities. Two influenza A/H3N2 dominant epidemic waves were seen in Hong Kong in 2015, but these epidemics were very minor in Shenzhen. More influenza B epidemics occurred in Shenzhen than in Hong Kong. Conclusions: Influenza epidemics appeared to be unsynchronized between Hong Kong and Shenzhen most of the time. Given the close geographical locations of these two cities, this could be due to the strikingly different age structures of their populations. Keywords: Influenza epidemics, Synchrony, Shenzhen, Hong Kong

  2. Physical nutrient transport in the North Atlantic Subtropical Gyre

    Science.gov (United States)

    Jenkins, W.; Lott, D. E.

    2009-04-01

    Use of the helium-3 flux gauge to estimate the physically mediated flux of new nutrients to the euphotic zone of the North Atlantic subtropical gyre broadly suggests a pathway whereby inorganic nutrients that have been remineralized within the main thermocline may be returned to the seasonally accessible layer in the Sargasso Sea: the so-called "Nutrient Spiral" (Jenkins and Doney (2003), Glob. Biog. Cyc., 17(4), doi:1110.1029/2003GB002085.) The challenge, however, is identifying the exact mechanism whereby this occurs. One possible process is that of "obduction", whereby the combination of strong advection and rapidly deepening winter mixed layers result in the effective outcropping of substantial amounts of thermocline nutrients and tritiugenic helium-3. We present here a quantitative estimate based on hydrographic sections and geostrophic transports of the fluxes and transformations of both tritugenic helium-3 and nitrate within the basin, and attempt to relate these estimates to the specific shallow-water behaviors of these tracers, and their global and regional physical transports. An important constraint for these estimates lies in the evolving distributions of the transient tracers tritium and helium-3. We compare these results with other tracer-based estimates of new, net-community, and export production.

  3. Factors regulating trophic status in a large subtropical reservoir, China.

    Science.gov (United States)

    Xu, Yaoyang; Cai, Qinghua; Han, Xinqin; Shao, Meiling; Liu, Ruiqiu

    2010-10-01

    We evaluated a 4-year data set (July 2003 to June 2007) to assess the trophic state and its limiting factors of Three-Gorges Reservoir (TGR), China, a large subtropical reservoir. Based on Carlson-type trophic state index (TSI)(CHL), the trophic state of the system was oligotrophic (TSI(S) TSI(TP) and TSI(TN) were higher than the critical value of eutrophic state (TSI(S) > 50). Using Carlson's (1991) two-dimensional approach, deviations of the TSI(S) indicated that factors other than phosphorus and nitrogen limited algal growth and that nonalgal particles affected light attenuation. These findings were further supported by the significant correlation among the values of TSI(CHL) - TSI(SD) and nonvolatile suspended solids and water residence time. The logarithmic model showed that an equivalent TSI(CHL) and TSI(SD) could be found at tau = 54 days in the TGR (Fig. 7). Accordingly, nonalgal particulates dominated light attenuation and limited algal biomass of the reservoir when tau < 54 days.

  4. Variability of the subtropical mode water in the Southwest Pacific

    Science.gov (United States)

    Fernandez, Denise; Sutton, Philip; Bowen, Melissa

    2017-09-01

    The variability of Subtropical Mode Water (STMW) in the Southwest Pacific is investigated using a 28 year-long time series (1986-2014) of high-resolution expendable bathythermograph data north of New Zealand (PX06) and a shorter time series, the Roemmich-Gilson monthly Argo optimal interpolation for the 2004-2014 period. The variability in STMW inventories is compared to the variability in air-sea heat fluxes, mixed layer depths and transport of the East Auckland Current (EAUC) to assess both the atmospheric and oceanic roles influencing the formation and decay of STMW. The STMW north of New Zealand has a short lifespan with little persistence of the water mass from 1 year to the next one. Deeper mixed layers and negative anomalies in surface heat fluxes are correlated with increased formation of STMW. The heat content of the STMW layer is anticorrelated with inventories, particularly during the El Niño years. This suggests that large volumes of STMW are coincident with cooler conditions in the prior winter and less oceanic heat storage. There is significant seasonal and interannual variability in STMW inventories, however there are no trends in STMW properties, including its core layer temperature over the last decade. The variability of the winter EAUC transport is highly correlated with the STMW inventories and thermocline depth in the following spring, suggesting ocean dynamics deepen the thermocline and precondition for deeper mixed layers.

  5. Adaptive Drainage Slots for Acoustic Noise Attenuation Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Cornerstone Research Group, Inc. (CRG), proposes to demonstrate feasibility in the reduction of noise attributed to drainage slots in jet engine acoustic liners....

  6. Adaptive Drainage Slots for Acoustic Noise Attenuation Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Cornerstone Research Group, Inc. (CRG) demonstrated feasibility in the reduction of noise attributed to drainage slots in jet engine acoustic liners. This was...

  7. Pre-operative biliary drainage for obstructive jaundice

    Science.gov (United States)

    Fang, Yuan; Gurusamy, Kurinchi Selvan; Wang, Qin; Davidson, Brian R; Lin, He; Xie, Xiaodong; Wang, Chaohua

    2014-01-01

    Background Patients with obstructive jaundice have various pathophysiological changes that affect the liver, kidney, heart, and the immune system. There is considerable controversy as to whether temporary relief of biliary obstruction prior to major definitive surgery (pre-operative biliary drainage) is of any benefit to the patient. Objectives To assess the benefits and harms of pre-operative biliary drainage versus no pre-operative biliary drainage (direct surgery) in patients with obstructive jaundice (irrespective of a benign or malignant cause). Search methods We searched the Cochrane Hepato-Biliary Group Controlled Trials Register, Cochrane Central Register of Controlled Clinical Trials (CENTRAL) in The Cochrane Library, MEDLINE, EMBASE, and Science Citation Index Expanded until February 2012. Selection criteria We included all randomised clinical trials comparing biliary drainage followed by surgery versus direct surgery, performed for obstructive jaundice, irrespective of the sample size, language, and publication status. Data collection and analysis Two authors independently assessed trials for inclusion and extracted data. We calculated the risk ratio (RR), rate ratio (RaR), or mean difference (MD) with 95% confidence intervals (CI) based on the available patient analyses. We assessed the risk of bias (systematic overestimation of benefit or systematic underestimation of harm) with components of the Cochrane risk of bias tool. We assessed the risk of play of chance (random errors) with trial sequential analysis. Main results We included six trials with 520 patients comparing pre-operative biliary drainage (265 patients) versus no pre-operative biliary drainage (255 patients). Four trials used percutaneous transhepatic biliary drainage and two trials used endoscopic sphincterotomy and stenting as the method of pre-operative biliary drainage. The risk of bias was high in all trials. The proportion of patients with malignant obstruction varied between 60

  8. Vegetation damage and recovery after Chiginagak Volcano Crater drainage event

    Data.gov (United States)

    Department of the Interior — From August 20 — 23, 2006, I revisited Chiginigak volcano to document vegetation recovery after the crater drainage event that severely damaged vegetation in May of...

  9. Drainage facility management system : final report, June 2009.

    Science.gov (United States)

    2009-06-01

    This research project identified requirements for a drainage facility management system for the Oregon Department of Transportation. It also estimated the personnel resources needed to collect the inventory to populate such a system with data. A tota...

  10. Drainage identification analysis and mapping, phase 2 : technical brief.

    Science.gov (United States)

    2017-01-01

    This research studied, tested and rectified the compatibility issue related to the recent upgrades of : NJDOT vendor inspection software, and uploaded all collected data to make Drainage Identification : Analysis and Mapping System (DIAMS) current an...

  11. Ross Ice Drainage System (RIDS) Glaciochemical Analysis, Version 1

    Data.gov (United States)

    National Aeronautics and Space Administration — The Ross Ice Drainage System (RIDS) project provides a high-resolution record of atmospheric chemical deposition taken from several ice cores and snow pits located...

  12. A skin abscess model for teaching incision and drainage procedures.

    Science.gov (United States)

    Fitch, Michael T; Manthey, David E; McGinnis, Henderson D; Nicks, Bret A; Pariyadath, Manoj

    2008-07-03

    Skin and soft tissue infections are increasingly prevalent clinical problems, and it is important for health care practitioners to be well trained in how to treat skin abscesses. A realistic model of abscess incision and drainage will allow trainees to learn and practice this basic physician procedure. We developed a realistic model of skin abscess formation to demonstrate the technique of incision and drainage for educational purposes. The creation of this model is described in detail in this report. This model has been successfully used to develop and disseminate a multimedia video production for teaching this medical procedure. Clinical faculty and resident physicians find this model to be a realistic method for demonstrating abscess incision and drainage. This manuscript provides a detailed description of our model of abscess incision and drainage for medical education. Clinical educators can incorporate this model into skills labs or demonstrations for teaching this basic procedure.

  13. Accelerating transient drainage from UMTRA Project tailings piles

    International Nuclear Information System (INIS)

    1990-09-01

    The period between the completion of construction of the tailings disposal cell and the establishment of equilibrium moisture content and seepage conditions is considered to be the period of transient drainage. Transient drainage may be due to factors such as construction water, precipitation, or residual water from the milling process. Transient seepage rates usually exceed steady state seepage rates. If the transient seepage rate causes contaminant levels to exceed groundwater compliance standards, then an alternative groundwater compliance strategy or technical approach to reduce or mitigate the effects of the drainage must be adopted. This study examines methods to accelerate the transient drainage of soils and hence to remove excess pore water from tailings in UMTRA Project disposal cells. The technical and economic feasibility of possible methods is examined. In order to perform comparative economical analyses of the various methods, an example tailings pile is postulated. This pile is considered to be 300 meters by 300 meters by 10 meters in thickness

  14. Improvement and Expansion of Drainage Networks in Trillo and Almaraz to face heavy rains; Mejora y ampliacion de las redes de drenajes de C. N. Trillo y c. N. Almaraz para hace frente a lluvias intensas

    Energy Technology Data Exchange (ETDEWEB)

    Gavela, M.; Font, I.; Fernandez, E. J.

    2013-07-01

    This presentation outlines the adequacy of drainage networks in the Trillo and Almaraz precipitation values for a return period of 10,000 years. On the other hand includes the design of retention ponds to arriving effluent storm water networks, planned to contain the spillage of water possibly polluting the environment in the event if necessary a water treatment.

  15. Properties of the subglacial till inferred from supraglacial lake drainage

    Science.gov (United States)

    Neufeld, J. A.; Hewitt, D.

    2017-12-01

    The buildup and drainage of supraglacial lakes along the margins of the Greenland ice sheet has been previously observed using detailed GPS campaigns which show that rapid drainage events are often preceded by localised, transient uplift followed by rapid, and much broader scale, uplift and flexure associated with the main drainage event [1,2]. Previous models of these events have focused on fracturing during rapid lake drainage from an impermeable bedrock [3] or a thin subglacial film [4]. We present a new model of supraglacial drainage that couples the water flux from rapid lake drainage events to a simplified model of the pore-pressure in a porous, subglacial till along with a simplified model of the flexure of glacial ice. Using a hybrid mathematical model we explore the internal transitions between turbulent and laminar flow throughout the evolving subglacial cavity and porous till. The model predicts that an initially small water flux may locally increase pore-pressure in the till leading to uplift and a local divergence in the ice velocity that may ultimately be responsible for large hydro-fracturing and full-scale drainage events. Furthermore, we find that during rapid drainage while the presence of a porous, subglacial till is crucial for propagation, the manner of spreading is remarkably insensitive to the properties of the subglacial till. This is in stark contrast to the post-drainage relaxation of the pore pressure, and hence sliding velocity, which is highly sensitive to the permeability, compressibility and thickness of subglacial till. We use our model, and the inferred sensitivity to the properties of the subglacial till after the main drainage event, to infer the properties of the subglacial till. The results suggest that a detailed interpretation of supraglacial lake drainage may provide important insights into the hydrology of the subglacial till along the margins of the Greenland ice sheet, and the coupling of pore pressure in subglacial till

  16. Indoor air quality of a museum in a subtropical climate: The Oscar Niemeyer museum in Curitiba, Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Godoi, Ricardo H.M., E-mail: rhmgodoi@ufpr.br [Federal University of Paraná, Environmental Engineering Department, Curitiba, PR (Brazil); Carneiro, Barbara H.B. [University of Positivo, Curitiba (Brazil); Paralovo, Sarah L. [Federal University of Paraná, Environmental Engineering Department, Curitiba, PR (Brazil); Campos, Vania P.; Tavares, Tania M. [Institute of Chemistry, Federal University of Bahia, Salvador, BA (Brazil); Evangelista, Heitor [LARAMG/Department of Biophysics and Biometry, Rio de Janeiro State University, Rio de Janeiro, RJ (Brazil); Van Grieken, Rene [Department of Chemistry, University of Antwerp, Universiteitsplein 1, B-2610 Antwerp (Belgium); Godoi, Ana F.L. [Federal University of Paraná, Environmental Engineering Department, Curitiba, PR (Brazil)

    2013-05-01

    The assessment of damage to indoor cultural heritage, in particular by pollutants, is nowadays a major and growing concern for curators and conservators. Nevertheless, although many museums have been widely investigated in Europe, the effects of particulate matter and gaseous pollutants in museums under tropical and subtropical climates and with different economic realities are still unclear. An important portion of the world's cultural heritage is currently in tropical countries where both human and financial resources for preserving museum collections are limited. Hence, our aim is to assess the damage that can be caused to the artwork by pollution in hot and humid environments, where air quality and microclimatic condition differences can cause deterioration. As a case study, particulate matter as well as gases were collected at the Oscar Niemeyer Museum (MON) in Curitiba, Brazil, where large modern and contemporary works of art are displayed. NO{sub 2}, SO{sub 2}, O{sub 3}, Acetic Acid, Formic Acids and BTEX, in the ambient air, were sampled by means of passive diffusive sampling and their concentrations were determined by IC or GC–MS. The particulate matter was collected in bulk form and analyzed with the use of energy dispersive X-ray fluorescence and aethalometer. The chemical compositions of individual particles were quantitatively elucidated, including low-Z components like C, N and O, as well as higher-Z elements, using automated electron probe microanalysis. The gaseous and particulate matter levels were then compared with the concentrations obtained for the same pollutants in other museums, located in places with different climates, and with some reference values provided by international cultural heritage conservation centers. Results are interpreted separately and as a whole with the specific aim of identifying compounds that could contribute to the chemical reactions taking place on the surfaces of artifacts and which could potentially cause

  17. Indoor air quality of a museum in a subtropical climate: The Oscar Niemeyer museum in Curitiba, Brazil

    International Nuclear Information System (INIS)

    Godoi, Ricardo H.M.; Carneiro, Barbara H.B.; Paralovo, Sarah L.; Campos, Vania P.; Tavares, Tania M.; Evangelista, Heitor; Van Grieken, Rene; Godoi, Ana F.L.

    2013-01-01

    The assessment of damage to indoor cultural heritage, in particular by pollutants, is nowadays a major and growing concern for curators and conservators. Nevertheless, although many museums have been widely investigated in Europe, the effects of particulate matter and gaseous pollutants in museums under tropical and subtropical climates and with different economic realities are still unclear. An important portion of the world's cultural heritage is currently in tropical countries where both human and financial resources for preserving museum collections are limited. Hence, our aim is to assess the damage that can be caused to the artwork by pollution in hot and humid environments, where air quality and microclimatic condition differences can cause deterioration. As a case study, particulate matter as well as gases were collected at the Oscar Niemeyer Museum (MON) in Curitiba, Brazil, where large modern and contemporary works of art are displayed. NO 2 , SO 2 , O 3 , Acetic Acid, Formic Acids and BTEX, in the ambient air, were sampled by means of passive diffusive sampling and their concentrations were determined by IC or GC–MS. The particulate matter was collected in bulk form and analyzed with the use of energy dispersive X-ray fluorescence and aethalometer. The chemical compositions of individual particles were quantitatively elucidated, including low-Z components like C, N and O, as well as higher-Z elements, using automated electron probe microanalysis. The gaseous and particulate matter levels were then compared with the concentrations obtained for the same pollutants in other museums, located in places with different climates, and with some reference values provided by international cultural heritage conservation centers. Results are interpreted separately and as a whole with the specific aim of identifying compounds that could contribute to the chemical reactions taking place on the surfaces of artifacts and which could potentially cause irreversible

  18. Infected Baerveldt Glaucoma Drainage Device by Aspergillus niger

    Directory of Open Access Journals (Sweden)

    Nurul-Laila Salim

    2015-01-01

    Full Text Available Fungal endophthalmitis is rare but may complicate glaucoma drainage device surgery. Management is challenging as the symptoms and signs may be subtle at initial presentation and the visual prognosis is usually poor due to its resistant nature to treatment. At present there is lesser experience with intravitreal injection of voriconazole as compared to Amphotericin B. We present a case of successfully treated Aspergillus endophthalmitis following Baerveldt glaucoma drainage device implantation with intravitreal and topical voriconazole.

  19. Percutaneous drainage of complicated abscesses and fluid collections

    International Nuclear Information System (INIS)

    Wittich, G.R.; Karnel, F.; Kumpan, W.; Herold, C.; Schurawitzki, H.; Van Sonnenberg, E.; Casola, G.; Jantsch, H.

    1987-01-01

    The original concept of percutaneous, radiological abscess drainage was confined to well circumscribed, solitary abscesses, that could be reached by a short access avoiding transgression of uninvolved organs or compartments. With increasing experience criteria for percutaneous abscess drainage have been expanded to radiological treatment of pancreatic, periappendiceal, diverticular, interloop and mediastinal abscesses and fluid collections. The authors present their experience with percutaneous treatment of such 'complicated' abscesses in 140 patients. (orig.) [de

  20. Distributed Leadership in Drainage Basin Management: A Critical Analysis of ‘River Chief Policy’ from a Distributed Leadership Perspective

    Science.gov (United States)

    Zhang, Liuyi

    2018-02-01

    Water resources management has been more significant than ever since the official file stipulated ‘three red lines’ to scrupulously control water usage and water pollution, accelerating the promotion of ‘River Chief Policy’ throughout China. The policy launches creative approaches to include people from different administrative levels to participate and distributes power to increase drainage basin management efficiency. Its execution resembles features of distributed leadership theory, a vastly acknowledged western leadership theory with innovative perspective and visions to suit the modern world. This paper intends to analyse the policy from a distributed leadership perspective using Taylor’s critical policy analysis framework.

  1. Dissemination of regional rainfall analysis in design and analysis of urban drainage at un-gauged locations

    DEFF Research Database (Denmark)

    Arnbjerg-Nielsen, K.; Harremoes, Poul; Mikkelsen, Peter Steen

    2002-01-01

    regional variation of extreme rainfalls throughout the country. This has implications for design and analysis of all practical problems related to urban drainage, since the rainfall data so far recommended as input to engineering analyses underestimates the problems. Consequently, the Danish Water...... Pollution Control Committee has issued a statement recommending a new engineering practice. The dissemination of the research results proved to be difficult due to lack of understanding of the concepts of the new paradigm by practitioners. The traditional means of communication was supplemented by user...

  2. [Transport characteristics of air pollutants over the Yangtze Delta].

    Science.gov (United States)

    Wang, Yan; Chai, Fa-He; Wang, Yong-Hong; Liu, Ming

    2008-05-01

    Meteorological field of January, April, July and October in 2004 was obtained by running MM5 with NCEP datasets. Then we used HYSPLIT 4.8 model to calculate the backward and forward trajectories of representative cities. Distributions of trajectories and the affected areas vary with seasons. Transport current affecting Yangtze River Delta is mainly from Mongolia, North China or Northeast region, via Yellow Sea area, Shandong, Jiangsu province or Shanghai. Another important transport path is current from southwest because of the Southwest monsoon. A movement of East Asia monsoon plays an important part in the mesoscale transport of pollutants in Yangtze Delta. Winter monsoon is a main mechanism which moves the air pollutants in Yangtze Delta to South China and West Pacific ocean. Another important transport system is the subtropical anticyclone over the western Pacific Ocean which controls the east coast of our country in spring and summer. This circulation system mainly affects the inland area of our country.

  3. A framework to support decision making in the selection of sustainable drainage system design alternatives.

    Science.gov (United States)

    Wang, Mingming; Sweetapple, Chris; Fu, Guangtao; Farmani, Raziyeh; Butler, David

    2017-10-01

    This paper presents a new framework for decision making in sustainable drainage system (SuDS) scheme design. It integrates resilience, hydraulic performance, pollution control, rainwater usage, energy analysis, greenhouse gas (GHG) emissions and costs, and has 12 indicators. The multi-criteria analysis methods of entropy weight and Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) were selected to support SuDS scheme selection. The effectiveness of the framework is demonstrated with a SuDS case in China. Indicators used include flood volume, flood duration, a hydraulic performance indicator, cost and resilience. Resilience is an important design consideration, and it supports scheme selection in the case study. The proposed framework will help a decision maker to choose an appropriate design scheme for implementation without subjectivity. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Macroinvertebrate community response to acid mine drainage in rivers of the High Andes (Bolivia)

    International Nuclear Information System (INIS)

    Van Damme, Paul Andre; Hamel, Caroli; Ayala, Alfredo; Bervoets, Lieven

    2008-01-01

    Several High Andes Rivers are characterized by inorganic water pollution known as acid mine drainage (AMD). The aim of this study was to assess the relationship between metal concentrations in the sediments and the macroinvertebrate communities in two river basins affected by AMD. In general, the taxon diversity of the macroinvertebrate community at the family level was low. The concentrations of Cd, Cu, Zn, Pb and Ni at mining sites were higher than at unpolluted sites. The pH of the water was alkaline (7.0-8.5) in unpolluted sites, whereas it dropped to very low values (<3) at mining sites. Redundancy Analysis (RDA) showed that pH was the best predictor of macroinvertebrate community richness. The number of macroinvertebrate families decreased gradually with increasing acidity, both in pools and riffles, though it is suggested that riffle communities were more affected because they are in closer contact with the acid water. - Community response to AMD

  5. Human waterborne parasites in zebra mussels ( Dreissena polymorpha) from the Shannon River drainage area, Ireland.

    Science.gov (United States)

    Graczyk, Thaddeus K; Conn, David Bruce; Lucy, Frances; Minchin, Dan; Tamang, Leena; Moura, Lacy N S; DaSilva, Alexandre J

    2004-08-01

    Zebra mussels ( Dreissena polymorpha) from throughout the Shannon River drainage area in Ireland were tested for the anthropozoonotic waterborne parasites Cryptosporidium parvum, Giardia lamblia, Encephalitozoon intestinalis, E. hellem, and Enterocytozoon bieneusi, by the multiplexed combined direct immunofluorescent antibody and fluorescent in situ hybridization method, and PCR. Parasite transmission stages were found at 75% of sites, with the highest mean concentration of 16, nine, and eight C. parvum oocysts, G. lamblia cysts, and Encephalitozoon intestinalis spores/mussel, respectively. On average eight Enterocytozoon bieneusi spores/mussel were recovered at any selected site. Approximately 80% of all parasites were viable and thus capable of initiating human infection. The Shannon River is polluted with serious emerging human waterborne pathogens including C. parvum, against which no therapy exists. Zebra mussels can recover and concentrate environmentally derived pathogens and can be used for the sanitary assessment of water quality.

  6. Distribution of arsenic and mercury in subtropical coastal beachrock ...

    Indian Academy of Sciences (India)

    An assessment of coastal pollution was made on the basis of trace element concentrations (arsenic –As, mercury – Hg) in the Gulf of Mannar. The beachrock samples were collected along the coastal tracts between Rameswaram and Kanyakumari. The samples were dried and digested to determine the As and Hg using ...

  7. Distribution of arsenic and mercury in subtropical coastal beachrock ...

    Indian Academy of Sciences (India)

    An assessment of coastal pollution was made on the basis of trace element concentrations (arsenic –. As, mercury – Hg) in the ... to determine the As and Hg using atomic absorption spectrophotometer (AAS-air-acetylene and nitrous oxide method). ..... adjoining rivers, channels and regular monitoring of coastal zones are ...

  8. Distribution of arsenic and mercury in subtropical coastal beachrock ...

    Indian Academy of Sciences (India)

    An assessment of coastal pollution was made on the basis of trace element concentrations (arsenic –. As, mercury – Hg) in the Gulf of Mannar. The beachrock samples were collected along the coastal tracts between Rameswaram and Kanyakumari. The samples were dried and digested to determine the As and Hg using ...

  9. Is routine abdominal drainage necessary after liver resection?

    Science.gov (United States)

    Wada, Seidai; Hatano, Etsuro; Yoh, Tomoaki; Seo, Satoru; Taura, Kojiro; Yasuchika, Kentaro; Okajima, Hideaki; Kaido, Toshimi; Uemoto, Shinji

    2017-06-01

    Prophylactic abdominal drainage is performed routinely after liver resection in many centers. The aim of this study was to examine the safety and validity of liver resection without abdominal drainage and to clarify whether routine abdominal drainage after liver resection is necessary. Patients who underwent elective liver resection without bilio-enteric anastomosis between July, 2006 and June, 2012 were divided into two groups, based on whether surgery was performed before or after, we adopted the no-drain strategy. The "former group" comprised 256 patients operated on between July, 2006 and June, 2009 and the "latter group" comprised 218 patients operated between July, 2009 and June, 2012. We compared the postoperative complications, percutaneous drainage, and postoperative hospital stay between the groups, retrospectively. There were no significant differences in the rates of postoperative bleeding, intraabdominal infection, or bile leakage between the groups. Drain insertion after liver resection did not reduce the rate of percutaneous drainage. Postoperative hospital stay was significantly shorter in the latter group. Routine abdominal drainage is unnecessary after liver resection without bilio-enteric anastomosis.

  10. Percutaneous catheter drainage of intraabdominal abscesses and fluid

    International Nuclear Information System (INIS)

    Lee, Jong Tae; Kwon, Tae Hee; Yoo, Hyung Sik; Suh, Jung Ho; Lee, Young Ho

    1986-01-01

    Percutaneous catheter drainage has been reported to be an effective method in the management of selected patients with abscess and fluid collection. Its high success rate and relatively low complications make the procedure an alternative to surgery in the individual cases. During past two years percutaneous catheter drainage in 25 patients with intraabdominal abscesses and fluid collection was performed at the Department of Radiology, Yonsei University College of medicine. Here the technique and author's results were summarized. 1. The total 25 patients who had percutaneous catheter drainage are 10 liver abscesses, 3 subphrenic, one subhepatic, 4 renal and perirenal, 2 pelvic, one psoas, one anterior pararenal fluid from acute pancreatitis, one pancreas pseudocyst and 2 malignant tumor necrosis. 2. The modified Seldinger technique used for all cases of abscess and fluid drainage under guidance of ultrasound scan. The used catheters were 10F. Pigtail and 14F. Malecot (Cook c/o) catheters. 3. The abscesses and fluid of 17 patients among 25 were cured by the percutaneous catheter drainage and 4 patients were clinically improved. The catheter drainage was failed in 2 patients and 3 complication were developed. 4. The success rate of this procedure was 91.3%, failure rate was 8.7% and complication rate was 12%.

  11. Percutaneous transhepatic biliary drainage: analysis of 175 cases

    International Nuclear Information System (INIS)

    Suh, Kyung Jin; Lee, Sang Kwon; Kim, Tae Hun; Kim, Yong Joo; Kang, Duk Sik

    1990-01-01

    Percutaneous transhepatic biliary drainage is a safe, effective and palliative means of treatment in biliary obstruction, especially in cases with malignant obstruction which are inoperable. 175 cases of transhepatic biliary drainage were performed on 119 patients with biliary obstruction from January 1985 to June 1989 at Kyung-pook National University Hospital. The causes of obstructive jaundice were 110 malignant diseases and 9 benign diseases. The most common indication for drainage was palliative intervention of obstruction secondary to malignant tumor in 89 cases. 86 cases of external drainage were performed including 3 cases of left duct approach, 29 cases of external-internal drainage and 60 cases of endoprosthesis. In external and external-internal drainages, immediate major complications (11.9%) occurred, including not restricted to, but sepsis, bile peritonitis and hemobilia. Delayed major complications (42.9%) were mainly catheter related. The delayed major complication of endoprosthesis resulted from obstruction of the internal stent. The mean time period to reobstruction of the internal stent was about 12 weeks. To improve management status, regular follow-up is required, as is education of both patients and their families as to when immediate clinical attention is mandated. Close communication amongst the varying medical specialities involved will be necessary to provide optional treatment for each patient

  12. Do general dental practitioners leave teeth on 'open drainage'?

    Science.gov (United States)

    Eliyas, S; Barber, M W; Harris, I

    2013-12-01

    There is a need to ascertain the use of evidence-based dentistry in both primary and secondary care in order to tailor education. This study aims to evaluate the use of 'open drainage' as part of endodontic treatment in primary care in South Yorkshire. A questionnaire was circulated to 141 randomly selected general dental practitioners in the South Yorkshire area between January 2012 and January 2013. The response rate was 79% (112/141). Five of the returned questionnaires were incomplete and therefore not usable. Seventy-nine percent of respondents were general dental practitioners (GDPs) working in mainly NHS or mixed practices. The year of graduation varied between 1970 and 2011. Forty-one percent (44/107) stated that they had never left a tooth on open drainage. Twenty-nine percent (31/107) stated that they sometimes leave teeth on open drainage. Of those respondents who currently leave teeth on open drainage, most (68%) would leave teeth on open drainage for one to two days or less. This survey revealed that the practice of leaving teeth on open drainage is still present in general dental practice. Current guidelines do not comment on the use of this treatment modality. There is a need to ascertain further information about practices throughout the United Kingdom in order to provide clear evidence-based guidelines.

  13. Emission standards versus immission standards for assessing the impact of urban drainage on ephemeral receiving water bodies.

    Science.gov (United States)

    Freni, Gabriele; Mannina, Giorgio; Viviani, Gaspare

    2010-01-01

    In the past, emission standard indicators have been adopted by environmental regulation authorities in order to preserve the quality of a receiving water body. Such indicators are based on the frequency or magnitude of a polluted discharge that may be continuous or intermittent. In order to properly maintain the quality of receiving waters, the Water Framework Directive, following the basic ideas of British Urban Pollution Manual, has been established. The Directive has overtaken the emission-standard concept, substituting it with the stream-standard concept that fixes discharge limits for each polluting substance depending on the self-depurative characteristics of receiving waters. Stream-standard assessment requires the deployment of measurement campaigns that can be very expensive; furthermore, the measurement campaigns are usually not able to provide a link between the receiving water quality and the polluting sources. Therefore, it would be very useful to find a correlation between the quality status of the natural waters and the emission-based indicators. Thus, this study is aimed to finding a possible connection between the receiving water quality indicators drawn by environmental regulation authorities and emission-based indicators while considering both continuous (i.e. from the wastewater treatment plants) and intermittent pollution discharges (mainly from combined sewer overflows). Such research has been carried out by means of long-term analysis adopting a holistic modelling approach. The different parts of the integrated urban drainage system were modelled by a parsimonious integrated model. The analysis was applied to an ephemeral river bounding Bologna (Italy). The study concluded that the correlation between receiving water quality and polluting emissions cannot be generally stated. Nevertheless, specific analyses on polluting emissions were pointed out in the study highlighting cause-effect link between polluting sources and receiving water quality.

  14. Chemical profiling of oil and PAH polluted soil and drainage water

    DEFF Research Database (Denmark)

    Boll, Esther Sørensen

    of a polar group. I have worked with two test organisms that utilize this degradation pathway, the earthworm Eisenia Fetida and the terrestrial fungus Cunninghamella elegans. E. fetida was exposed to the two PAHs, phenanthrene and pyrene, in a hydroponic culture. E. fetida was extensively able to transform...

  15. 46 CFR 116.1120 - Drainage of cockpit vessels, well deck vessels, and open boats.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Drainage of cockpit vessels, well deck vessels, and open... PASSENGERS CONSTRUCTION AND ARRANGEMENT Drainage and Watertight Integrity of Weather Decks § 116.1120 Drainage of cockpit vessels, well deck vessels, and open boats. Drainage of cockpit vessels, well deck...

  16. Can cross-border pollution reduce pollution?

    OpenAIRE

    Panos Hatzipanayotou; Sajal Lahiri; Michael S. Michael

    2002-01-01

    We develop a North-South model of foreign aid and cross-border pollution resulting from production activities in the recipient country. There is both private and public abatement of pollution, the latter being financed through emissions tax revenue and foreign aid. We characterise a Nash equilibrium where the donor country chooses the amount of aid, and the recipient chooses the fraction of aid allocated to pollution abatement and/or the emission tax rate. At this equilibrium, an increase in ...

  17. Role of atmospheric circulations in haze pollution in December 2016

    Science.gov (United States)

    Yin, Zhicong; Wang, Huijun

    2017-09-01

    In the east of China, recent haze pollution has been severe and damaging. In addition to anthropogenic emissions, atmospheric circulations and local meteorological conditions were conducive factors. The number of December haze days over North China and the Huanghuai area has increased sharply since 2010 and was greatest in 2016. During 2016, the most aggressive control measures for anthropogenic emissions were implemented from 16 to 21 December, but the most severe haze pollution still occurred, covering approximately 25 % of the land area of China and lasting for 6 days. The atmospheric circulations must play critical roles in the sub-seasonal haze events. Actually, the positive phase of the East Atlantic-West Russia pattern in the middle troposphere strengthened the anomalous anti-cyclone over the NH area that confined vertical motion below. The associated southerly anomalies made the cold air and surface wind speed weaker, but enhanced the humid flow. Thus, the horizontal and vertical dispersion of atmospheric particulates was suppressed and the pollutants gathered within a narrow space. In December 2016, these key indices were strongly beneficial for haze occurrence and combined to result in the severest haze pollution. The influences of the preceding autumn sea surface temperature near the Gulf of Alaska and the subtropical eastern Pacific, October-November snow cover in western Siberia, and associated physical processes on haze pollution are also discussed.

  18. Sensitivity of drainage efficiency of cranberry fields to edaphic conditions

    Science.gov (United States)

    Periard, Yann; José Gumiere, Silvio; Rousseau, Alain N.; Caron, Jean; Hallema, Dennis W.

    2014-05-01

    Water management on a cranberry farm requires intelligent irrigation and drainage strategies to sustain strong productivity and minimize environmental impact. For example, to avoid propagation of disease and meet evapotranspiration demand, it is imperative to maintain optimal moisture conditions in the root zone, which depends on an efficient drainage system. However, several drainage problems have been identified in cranberry fields. Most of these drainage problems are due to the presence of a restrictive layer in the soil profile (Gumiere et al., 2014). The objective of this work is to evaluate the effects of a restrictive layer on the drainage efficiency by the bias of a multi-local sensitivity analysis. We have tested the sensitivity of the drainage efficiency to different input parameters set of soil hydraulic properties, geometrical parameters and climatic conditions. Soil water flux dynamic for every input parameters set was simulated with finite element model Hydrus 1D (Simanek et al., 2008). Multi-local sensitivity was calculated with the Gâteaux directional derivatives with the procedure described by Cheviron et al. (2010). Results indicate that drainage efficiency is more sensitive to soil hydraulic properties than geometrical parameters and climatic conditions. Then, the geometrical parameters of the depth are more sensitive than the thickness. The drainage efficiency was very insensitive to the climatic conditions. Understanding the sensitivity of drainage efficiency according to soil hydraulic properties, geometrical and climatic conditions are essential for diagnosis drainage problems. However, it becomes important to identify the mechanisms involved in the genesis of anthropogenic soils cranberry to identify conditions that may lead to the formation of a restrictive layer. References: Cheviron, B., S.J. Gumiere, Y. Le Bissonnais, R. Moussa and D. Raclot. 2010. Sensitivity analysis of distributed erosion models: Framework. Water Resources Research

  19. Sponge-rhodolith interactions in a subtropical estuarine system

    Science.gov (United States)

    Ávila, Enrique; Riosmena-Rodríguez, Rafael; Hinojosa-Arango, Gustavo

    2013-06-01

    The interactions between sponges and red macroalgae have been widely documented in tropical and subtropical environments worldwide, and many of them have been documented as mutualistic associations. Sponges, however, have also been frequently described as part of the associated fauna of rhodolith habitats (aggregations of free-living non-geniculated coralline macroalgae). Nonetheless, the types of interaction they establish as well as the role of sponges in these habitats remain unknown. In this study, the associations between sponges and rhodoliths were investigated in an estuarine ecosystem of the Mexican Pacific based on qualitative and quantitative data. A total of 13 sponge species were identified in five newly discovered rhodolith beds dominated by the non-geniculate coralline macroalga Lithophyllum margaritae. The sponge assemblages were strongly restricted to rhodolith habitats. The best predictor of sponge abundance (from 5.1 to 51.7 ind m-2) and species richness (from 2.6 to 6.1 sponge species m-2) was the rhodolith density rather than other population descriptors assessed (e.g., average size, branch density and sphericity). The identified sponges included a variety of forms: massive (46 %), encrusting (23 %), excavating (15 %), cushion-shape (8 %) and digitate (8 %). Moreover, more than 50 % of sponge species recorded (mainly massive and encrusting forms) were frequently found overgrowing and binding rhodoliths. Halichondria cf. semitubulosa and Mycale cecilia were the most common binding agents; these species bind an average of 3.1 and 6.6 rhodoliths per sponge individual, respectively. These findings reveal the importance of rhodoliths as habitat forming species, since these seaweed beds notably increased the substrate complexity in soft bottom environments. In addition, the relatively high abundance of sponges and their capability to bind rhodoliths suggest that these associated organisms could have an important contribution to rhodolith bed stability.

  20. Net Exchange Ecossistem in Subtropical Agriculture Area in Southern Brazil

    Science.gov (United States)

    Roberti, D. R.; Diaz, M.; Webler, G.; Fiorin, J.; de Moraes, O. L. L.; Teichrieb, C.; Amado, T.

    2015-12-01

    Southern Brazil contribute to 38% of Brazilian grain production. In contrast with the rest of the country, the south has a wet, subtropical climate that permits two annual harvests (double cropping system). The soybean and/or maize (summer) and black oat and/or wheat (winter) succession is widely used by farmers in plateau areas. In river natural lowlands, the cultivation of flooded irrigated rice is common. Changes in the land use affect the carbon, water and energy balance, and crop management practices, such as fertilization, water management, harvest and crop residues have influence in carbon exchange between the crop field and the atmosphere. This study quantifies the net exchange ecosystem (NEE) between the atmosphere and the crop cultivations in this wide region of Brazil from 2010 to 2014. We use data from two micrometeorological sites: Cruz Alta, with crop rotation and Cachoeira do Sul, with rice paddy. The carbon flux was analyzed using the eddy covariance method and gap filling procedures. The annual integration of data carbon demonstrates that the agroecosystems in southern Brazil is a acting as an light atmospheric CO2 sink. However, the NEE emissions that occurred in the fallow periods contributed negatively for such annual accumulation. To reduce this loss of CO2, farmers could cultivate plants in fallow periods, because there are favorable weather conditions for growing plants year round. Additionally, other management practices can increase the influx of C, including the production of more dry matter with cover crops by improving management and the immediate harvesting of crop after physiological maturity to reduce the period between maturation and harvest.

  1. Nitric Acid Uptake on Subtropical Cirrus Cloud Particles

    Science.gov (United States)

    Popp, P. J.; Gao, R. S.; Marcy, T. P.; Fahey, D. W.; Hudson, P. K.; Thompson, T. L.; Kaercher, B.; Ridley, B. A.; Weinheimer, A. J.; Knapp, D. J.; hide

    2004-01-01

    The redistribution of HNO3 via uptake and sedimentation by cirrus cloud particles is considered an important term in the upper tropospheric budget of reactive nitrogen. Numerous cirrus cloud encounters by the NASA WB-57F high-altitude research aircraft during the Cirrus Regional Study of Tropical Anvils and Cirrus Layers-Florida Area Cirrus Experiment (CRYSTAL-FACE) were accompanied by the observation of condensed-phase HNO3 with the NOAA chemical ionization mass spectrometer. The instrument measures HNO3 with two independent channels of detection connected to separate forward and downward facing inlets that allow a determination of the amount of HNO3 condensed on ice particles. Subtropical cirrus clouds, as indicated by the presence of ice particles, were observed coincident with condensed-phase HNO3 at temperatures of 197-224 K and pressures of 122-224 hPa. Maximum levels of condensed-phase HNO3 approached the gas-phase equivalent of 0.8 ppbv. Ice particle surface coverages as high as 1.4 # 10(exp 14) molecules/ square cm were observed. A dissociative Langmuir adsorption model, when using an empirically derived HNO3 adsorption enthalpy of -11.0 kcal/mol, effectively describes the observed molecular coverages to within a factor of 5. The percentage of total HNO3 in the condensed phase ranged from near zero to 100% in the observed cirrus clouds. With volume-weighted mean particle diameters up to 700 ?m and particle fall velocities up to 10 m/s, some observed clouds have significant potential to redistribute HNO3 in the upper troposphere.

  2. Nutrients retention in a small subtropical wetland (México

    Directory of Open Access Journals (Sweden)

    Martha B. Rendón-López

    2016-03-01

    Full Text Available In tropical areas very few studies have analysed wetlands’ ability to control nutrients. We analysed the efficiency of the Pátzcuaro subtropical wetland in Mexico to retain nutrients (total phosphorus: TP; soluble reactive phosphorus: PO43-, nitrite: NO2- and nitrate: NO3- and total suspended solids (TSS and its temporal variability from November 2011 to October 2012, where two hydrological different periods (dry and wet periods were included. The results indicate that, annually, this wetland reduced TP, 30.4%; PO43-, 19.2%; NO2-, 2.5%; NO3-, 17.6%; and TSS, 14.7%. However, the reduction % rose to 55.3% for TP and to 47.3% for PO43- during the dry period and to 14.1 % for NO2-, 49% for NO3- and 44.5% for TSS during the rainy period. These results show dependence on the hydrological cycle, although P retention is also related with uptake by a dense macrophyte community and with organic matter accumulation. The results obtained suggest that removal of N is due mainly to denitrification. TSS retention seems to respond to low speed hydraulics and the resistance generated by macrophytes roots and floating plants. Like other studies in temperate environments, this wetland seems to remove more efficiently P than N. Unlike that  in temperate environments where the highest nutrient retention occurs in autumn, we found the highest retention values for both NO2- and NO3- during summer (rainy period, and the lowest for P, probably due to release of P for the senescence of wetland plants during this period.   

  3. Classification scheme for acid rock drainage detection - the Hamersley Basin, Western Australia

    Science.gov (United States)

    Skrzypek, Grzegorz; Dogramaci, Shawan; McLean, Laura

    2017-04-01

    In arid environment where precipitation and surface water are very limited, groundwater is the most important freshwater resource. For this reasons it is intensively exploited and needs to be managed wisely and protected from pollutants. Acid rock drainage often constitutes a serious risk to groundwater quality, particularly in catchments that are subject to mining, large scale groundwater injection or abstraction. However, assessment of the potential acid rock drainage risk can be challenging, especially in carbonate rich environment, where the decreasing pH that usually accompanies pyrite oxidation, can be masked by the high pH-neutralisation capacity of carbonate minerals. In this study, we analysed 73 surface and groundwater samples from different water bodies and aquifers located in the Hamersley Basin, Western Australia. Although the majority of samples had a neutral pH, there was a large spatial variability in the dissolved sulphate concentrations that ranged from 1 mg/L to 15,000 mg/L. Waters with high dissolved sulphate concentration were found in areas with a high percentage of sulphide minerals (e.g. pyrite) located within the aquifer matrix and were characterised by low δ34SSO4 values (+1.2‰ to +4.6) consistent with signatures of aquifer matrix pyritic rock samples (+1.9‰ to +4.4). It was also found that the SO4 concentrations and acidity levels were not only dependent on δ34SSO4 values and existence of pyrite but also on the presence of carbonate minerals in the aquifer matrix. Based on the results from this study, a classification scheme has been developed for identification of waters impacted by acid rock drainage that also encompasses numerous concomitant geochemical processes that often occur in aqueous systems. The classification uses five proxies: SO4, SO4/Cl, SI of calcite, δ34SSO4 and δ18OSO4 to improve assessment of the contribution that oxidation of sulphide minerals has to overall sulphate ion concentrations, regardless of acidity

  4. THE POTENTIAL SOURCES OF POLLUTION AFFECTING THE WATER QUALITY OF LAKE IZNIK

    Directory of Open Access Journals (Sweden)

    Yalcın Askın OKTEM

    2013-01-01

    Full Text Available This study aimed to examine Lake Iznik, one of the most significant water resources of the South Marmara Region, and the anthropogenic pollution types affecting the drainage basin and their possible effects. Lake Iznik, a water resource that is quite significant because of its geographical position, is polluted not only with the point and non-point sources of pollution around it, but also with the pollutants spread via highways which are linear pollutants. The fertilization and disinfection of agricultural lands are considered to be one of the most significant factors changing the trophic level of the lake. Biological diversity of the lake is examined in many studies, while the studies on water quality are limited. The decrease in the type and amount of the productions of the lake indicates to the increasing destruction of the ecological balance as a result of the water pollution.

  5. Endoscopic computerized tomography guided percutaneous trans-gastric drainage: A case report on this hybrid approach

    OpenAIRE

    Tsutsui, Nobuhiro; Suzuki, Yutaka; Saito, Nobuhiro; Ohdaira, Hironori; Yamanouchi, Eigoro; Yoshida, Masashi

    2016-01-01

    Percutaneous drainage, percutaneous transgastric drainage, and endoscopic ultrasound (EUS)-guided transgastric drainage are primarily utilized for drainage of fluid collections dorsal to the stomach. Percutaneous transgastric drainage is performed with computed tomography (CT) guidance, but it requires inflation of a balloon in the stomach, and gastric peristalsis makes it difficult to ensure a reliable puncture route via the stomach. Using endoscopy-assisted CT-guidance, we were able to safe...

  6. Profile of thoracic trauma victims submitted to chest drainage

    Directory of Open Access Journals (Sweden)

    CESAR AUGUSTO BROSKA JÚNIOR

    Full Text Available ABSTRACT Objective: to describe and compare the variables involved in trauma victims undergoing thoracic drainage. Methods: we conducted a retrospective, analytical, descriptive, cross-sectional study, with medical records of patients attended at the Trauma Service of the Curitiba Evangelical University Hospital between February 2011 and January 2014. Results: there were 488 patients undergoing chest drainage, 84.7% men and 15.3% women, with an average age of 38.2 years. Attendances usually occurred at night, without predominance between open or closed mechanism, gender or age group. The majority of patients with thoracic trauma requiring drainage were diagnosed by anamnesis and physical examination (41.1% and drained in the emergency room (80.8%. Most of the patients (66.2% had another associated lesion, mostly some abdominal viscera. Complications were present in 16.6% (81 patients, most of them due to drainage positioning error (9.2%. The mean hospital stay was 15 days and drainage lasted for an average of 8.1 days, with no statistical difference between open and closed trauma. The clinical outcome was discharge in most cases. Conclusion: the profile of patients with thoracic trauma is that of young men, attended at night, with some other associated lesion. Although diagnosis and treatment were rapid and most often without the need for complex examinations, the time of drainage, hospitalization and complications were higher than in the literature, which can be explained by the drainage being made at the Emergency Room and the presence of associated injuries.

  7. A novel high vacuum chest drainage system - a pilot study.

    Science.gov (United States)

    Mrówczyński, Wojciech; Tille, Jean-Christophe; Khabiri, Ebrahim; Giliberto, Jean-Pierre; Courvoisier, Delphine S; Kalangos, Afksendiyos; Walpoth, Beat H

    2014-09-01

    To assess the safety and feasibility of use of a novel high vacuum chest drainage system (HVCDS) and its influence on the cardiovascular system compared to a conventional system (CCDS). Five anesthetized pigs underwent a median sternotomy. Three drains were placed in retrocardiac, retrosternal and left pleural positions. The animals received a HVCDS (22 Fr with 180 2-mm holes, n = 2) or a CCDS (n = 2). In the fifth animal off pump coronary artery bypass graft (OPCABG) stabilizers were tested. After chest closure animals had three 30 min runs of artificial bleeding (5 ml/min) under different negative aspiration pressures (-2, -20, -40 kPa) for both groups, followed by standardized surgical bleeding (-40 kPa - HVCDS, - 2 kPa - CCDS). Hemodynamic parameters and each drain's output were registered every 5 minutes and the residual blood was assessed. All catheters, the heart and left lung underwent macroscopic and histopathological examination. The application of the different pressures showed neither hemodynamic changes nor differences in blood drainage with both systems in two bleeding models. The HVCDS enabled drainage comparable to the CCDS but showed relevant clotting. Application of -20 kPa and -40 kPa caused macroscopic epicardial and pulmonary lesions in all tested devices including OPCABG stabilizers consisting of sub-epicardial or sub-pleural hemorrhage without myocyte or alveolar damage. The novel and conventional chest drainage systems used at pressures up to 40 kPa induced no hemodynamic instability. Both systems showed adequate equal drainage, despite major HVCDS clotting. High negative pressure drainage with both systems showed focal sub-epicardial and subpleural hemorrhage. Thus, long-term assessment of high pressure drainage and potential interaction with fragile structures (coronary bypass graft) should be carried out.

  8. Nitrogen budget in the Changjiang River drainage area

    Science.gov (United States)

    Jiang, Tao; Yu, Zhiming; Song, Xiuxian; Cao, Xihua

    2012-07-01

    We established a budget model of nitrogen (N) inputs and outputs between watersheds and waterbodies to determine the sources of riverine N in the Changjiang (Yangtze) River drainage area. Nitrogen inputs in the budget included N from synthetic fertilizer, biological fixation by leguminous and other crops, wet/dry atmospheric deposition, excreta from humans and animals, and crop residues. The total N input was estimated to be 17.6 Tg, of which 20% or 3.5 Tg N was transported into waterbodies. Of the total N transported into waterbodies, the largest proportion was N from animal waste (26%), followed by N from atmospheric wet/dry deposition (25%), synthetic fertilizer N (17%), N in sewage wastes (17%), N in human waste from rural areas (6%) and industrial wastewater N (9%). We studied the spatial patterns of N inputs and outputs by dividing the Changjiang River drainage area into four sub-basins, from upstream to downstream: the Tongtian River drainage area (TTD, the headwater drainage area, 138 000 km2, less disturbed by human activities); the Jinsha River drainage area (JSD, 347 000 km2, less disturbed by human activities, approx. 3 500 km upstream of the Changjiang estuary); the Pingshan-Yichang drainage area (PYD, 520 500 km2, large-scale human disturbance, about 2 000 km upstream of the Changjiang estuary); and the Yichang-Datong drainage area (YDD, 699 900 km2, large-scale human disturbance, approx. 620 km upstream of the Changjiang estuary). The average N input into waterbodies was 2.3, 7.3, 24.1, and 28.2 kg N/ha in the TTD, JSD, PYD, and YDD sub-basins, respectively, suggesting an increase of N-components of more than 10 times from upstream to downstream areas.

  9. Exocrine drainage in vascularized pancreas transplantation in the new millennium.

    Science.gov (United States)

    El-Hennawy, Hany; Stratta, Robert J; Smith, Fowler

    2016-06-24

    The history of vascularized pancreas transplantation largely parallels developments in immunosuppression and technical refinements in transplant surgery. From the late-1980s to 1995, most pancreas transplants were whole organ pancreatic grafts with insulin delivery to the iliac vein and diversion of the pancreatic ductal secretions to the urinary bladder (systemic-bladder technique). The advent of bladder drainage revolutionized the safety and improved the success of pancreas transplantation. However, starting in 1995, a seismic change occurred from bladder to bowel exocrine drainage coincident with improvements in immunosuppression, preservation techniques, diagnostic monitoring, general medical care, and the success and frequency of enteric conversion. In the new millennium, pancreas transplants are performed predominantly as pancreatico-duodenal grafts with enteric diversion of the pancreatic ductal secretions coupled with iliac vein provision of insulin (systemic-enteric technique) although the systemic-bladder technique endures as a preferred alternative in selected cases. In the early 1990s, a novel technique of venous drainage into the superior mesenteric vein combined with bowel exocrine diversion (portal-enteric technique) was designed and subsequently refined over the next ≥ 20 years to re-create the natural physiology of the pancreas with first-pass hepatic processing of insulin. Enteric drainage usually refers to jejunal or ileal diversion of the exocrine secretions either with a primary enteric anastomosis or with an additional Roux limb. The portal-enteric technique has spawned a number of newer and revisited techniques of enteric exocrine drainage including duodenal or gastric diversion. Reports in the literature suggest no differences in pancreas transplant outcomes irrespective of type of either venous or exocrine diversion. The purpose of this review is to examine the literature on exocrine drainage in the new millennium (the purported "enteric

  10. Using Drainage Slots in Permeable Paving Blocks to Delay the Effects of Clogging: Proof of Concept Study

    Directory of Open Access Journals (Sweden)

    Terry Lucke

    2014-09-01

    Full Text Available Permeable interlocking concrete pavements (PICP are specifically designed to remove sediment and other pollutants from stormwater runoff. Over time, this can lead to clogging of the PICP system. Previous research has shown that much of the clogging occurs on the bedding aggregate directly below the paving joints, while the remainder of the aggregate is unaffected. This paper describes a proof of concept study to delay the effects of clogging by making more efficient use of the bedding aggregate used in PICP systems. Lateral drainage slots were cut into the underside of PICP blocks to allow sediment-laden stormwater to access, and be filtered by, a greater surface area of bedding aggregate. Eight different slot designs were trialed in the study to determine which of the slot designs made the most efficient use of the bedding aggregate to filter the sediment from the stormwater. The study results demonstrated that the eight drainage slot designs deposited between 25% and 366% more sediment (by weight beneath the pavers than the control pavement. The results of the study suggest that PICP systems with drainage slots cast into their bases would take much longer to clog than unmodified pavers, thereby proving the concept of this study.

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

    Science.gov (United States)

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

    2009-01-01

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

  12. Combined environmental stress from shrimp farm and dredging releases in a subtropical coastal lagoon (SE Gulf of California).

    Science.gov (United States)

    Cardoso-Mohedano, J G; Páez-Osuna, F; Amezcua-Martínez, F; Ruiz-Fernández, A C; Ramírez-Reséndiz, G; Sanchez-Cabeza, J A

    2016-03-15

    Nutrient pollution causes environmental damages on aquatic ecosystems worldwide. Eutrophication produces impacts in coastal ecosystems, affecting biota and ecosystem services. The Urias coastal lagoon (SE Gulf of California) is a sub-tropical estuary under several environmental pressures such as nutrient inputs from shrimp farm effluents and dredging related to port operations, which can release substances accumulated in sediments. We assessed the water quality impacts caused by these activities and results showed that i) nitrogen was the limiting nutrient, ii) shrimp farm effluents increased particulate organic matter and chlorophyll a in the receiving stations, and iii) dredging activities increased nitrite and reduced dissolved oxygen concentrations. The co-occurrence of the shrimp farm releases and dredging activities was likely the cause of a negative synergistic effect on water quality which mainly decreases dissolved oxygen and increases nitrite concentrations. Coastal zone management should avoid the co-occurrence of these, and likely others, stressors in coastal ecosystems. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. Organochlorine pesticides and polychlorinated biphenyls along an east-to-west gradient in subtropical North Atlantic surface water.

    Science.gov (United States)

    Lammel, Gerhard; Spitzy, Alejandro; Audy, Ondřej; Beckmann, Sabine; Codling, Garry P; Kretzschmann, Lisett; Kukučka, Petr; Stemmler, Irene

    2017-04-01

    Despite the fact that most persistent toxic substances have hardly been primarily emitted for several decades, their concentrations are only slowly decreasing in the global oceans. Surface seawater samples were collected along a 38°-24° N/28°-67° W transect in the subtropical North Atlantic Ocean. While the concentration levels of hexachlorobenzene (2.1-6.1 pg L -1 ), dichlorodiphenyltrichloroethane (DDT, up to 2.1 pg L -1 ) and polychlorinated biphenyls (PCB, 10.8-24.9 pg L -1 ) were in the same range as observed earlier in the North Atlantic, hexachlorocyclohexane (HCH, 90-627 pg L -1 ) was found elevated, partly also relative to previous measurements in the same sea region. Hereby, the ratio α-HCH/γ-HCH was very low, 0.09-0.13. Chlordane and endosulfan were found in the range pollution patterns in surface seawaters seem to be determined by atmospheric and oceanic transport patterns, rather than by mixing and air-sea equilibrium. The comparison with global multicompartment chemistry-transport model predictions of surface seawater levels indicate underestimated degradation of PCBs and overestimated emissions of endosulfan.

  14. Plastic ingestion in oceanic-stage loggerhead sea turtles (Caretta caretta) off the North Atlantic subtropical gyre.

    Science.gov (United States)

    Pham, Christopher K; Rodríguez, Yasmina; Dauphin, Axelle; Carriço, Rita; Frias, João P G L; Vandeperre, Frederic; Otero, Vanessa; Santos, Marco R; Martins, Helen R; Bolten, Alan B; Bjorndal, Karen A

    2017-08-15

    Juvenile oceanic-stage sea turtles are particularly vulnerable to the increasing quantity of plastic coming into the oceans. In this study, we analysed the gastrointestinal tracts of 24 juvenile oceanic-stage loggerheads (Caretta caretta) collected off the North Atlantic subtropical gyre, in the Azores region, a key feeding ground for juvenile loggerheads. Twenty individuals were found to have ingested marine debris (83%), composed exclusively of plastic items (primarily polyethylene and polypropylene) identified by μ-Fourier Transform Infrared Spectroscopy. Large microplastics (1-5mm) represented 25% of the total number of debris and were found in 58% of the individuals sampled. Average number of items was 15.83±6.09 (±SE) per individual, corresponding to a mean dry mass of 1.07±0.41g. The results of this study demonstrate that plastic pollution acts as another stressor for this critical life stage of loggerhead turtles in the North Atlantic. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Physiological Responses of Two Epiphytic Bryophytes to Nitrogen, Phosphorus and Sulfur Addition in a Subtropical Montane Cloud Forest.

    Science.gov (United States)

    Chen, Xi; Liu, Wen-Yao; Song, Liang; Li, Su; Wu, Yi; Shi, Xian-Meng; Huang, Jun-Biao; Wu, Chuan-Sheng

    2016-01-01

    Atmospheric depositions pose significant threats to biodiversity and ecosystem function. However, the underlying physiological mechanisms are not well understood, and few studies have considered the combined effects and interactions of multiple pollutants. This in situ study explored the physiological responses of two epiphytic bryophytes to combined addition of nitrogen, phosphorus and sulfur. We investigated the electrical conductivity (EC), total chlorophyll concentration (Chl), nutrient stoichiometry and chlorophyll fluorescence signals in a subtropical montane cloud forest in south-west China. The results showed that enhanced fertilizer additions imposed detrimental effects on bryophytes, and the combined enrichment of simulated fertilization exerted limited synergistic effects in their natural environments. On the whole, EC, Chl, the effective quantum yield of photosystem II (ΦPSII) and photochemical quenching (qP) were the more reliable indicators of increased artificial fertilization. However, conclusions on nutrient stoichiometry should be drawn cautiously concerning the saturation uptake and nutrient interactions in bryophytes. Finally, we discuss the limitations of prevailing fertilization experiments and emphasize the importance of long-term data available for future investigations.

  16. Differential utility of the Bacteroidales DNA and RNA markers in the tiered approach for microbial source tracking in subtropical seawater.

    Science.gov (United States)

    Liu, Rulong; Cheng, Ken H F; Wong, Klaine; Cheng, Samuel C S; Lau, Stanley C K

    2015-07-01

    Source tracking of fecal pollution is an emerging component in water quality monitoring. It may be implemented in a tiered approach involving Escherichia coli and/or Enterococcus spp. as the standard fecal indicator bacteria (FIB) and the 16S rRNA gene markers of Bacteroidales as source identifiers. The relative population dynamics of the source identifiers and the FIB may strongly influence the implementation of such approach. Currently, the relative performance of DNA and RNA as detection targets of Bacteroidales markers in the tiered approach is not known. We compared the decay of the DNA and RNA of the total (AllBac) and ruminant specific (CF128) Bacteroidales markers with those of the FIB in seawater spiked with cattle feces. Four treatments of light and oxygen availability simulating the subtropical seawater of Hong Kong were tested. All Bacteroidales markers decayed significantly slower than the FIB in all treatments. Nonetheless, the concentrations of the DNA and RNA markers and E. coli correlated significantly in normoxic seawater independent of light availability, and in hypoxic seawater only under light. In hypoxic seawater without light, the concentrations of RNA but not DNA markers correlated with that of E. coli. Generally, the correlations between Enterococcus spp. and Bacteroidales were insignificant. These results suggest that either DNA or RNA markers may complement E. coli in the tiered approach for normoxic or hypoxic seawater under light. When light is absent, either DNA or RNA markers may serve for normoxic seawater, but only the RNA markers are suitable for hypoxic seawater.

  17. Optimal pollution trading without pollution reductions

    Science.gov (United States)

    Many kinds of water pollution occur in pulses, e.g., agricultural and urban runoff. Ecosystems, such as wetlands, can serve to regulate these pulses and smooth pollution distributions over time. This smoothing reduces total environmental damages when “instantaneous” damages are m...

  18. Condensation heating of the Asian summer monsoon and the subtropical anticyclone in the Eastern Hemisphere

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Y.M.; Wu, G.X.; Liu, H.; Liu, P. [Chinese Academy of Sciences, Beijing (China). Inst. of Atmospheric Physics

    2001-02-01

    The effects of condensation heating on the formation of the subtropical anticyclone in the Eastern Hemisphere (EH) are studied by means of theoretical analysis and numerical simulation. The complete vorticity equation is employed for the analysis. It is found that, due to the vertical gradient of strong condensation heating, the distribution of cyclone and anticyclone in the upper troposphere is out of phase with that in the middle and lower troposphere. This is confirmed by a series of numerical experiments. The horizontal gradient of the condensation heating also affects the configuration of the subtropical anticyclone. It is concluded that condensation heating is a key factor for the formation and location of the summer subtropical anticyclone in the EH. The latent heating released by the Asian monsoon rainfall contributes to the formation of the 200 hPa South Asian anticyclone on the western side of the heating center and the 500 hPa western Pacific subtropical anticyclone on the eastern side of the center. Such configurations are modified to some extent by surface sensible heating and orography. The circulation in mid-latitudes is also affected by the latent heating in the subtropical area through the propagation of Rossby waves. (orig.)

  19. Groundwater management for pollution control: a case study for oil shale mining in Northeast Estonia

    International Nuclear Information System (INIS)

    Erg, K.; Raukas, A.

    2001-01-01

    In Estonia oil shale is produced by underground and surface mining. The excavation methods used cause serious damage to the environment, especially to the topography, which hampers the further use of the mined-out areas. The oil shale mining has a serious impact on the environment also due to the pollution of surface and groundwater by polluted mine drainage waters, lowering of groundwater level, changing of soil properties and high air pollution rate. Decline in mining activities and the introduction of new technologies together with economic measures has improved the situation but much should be done during coming years. (author)

  20. Evaluation of Critical Parameters to Improve Slope Drainage System

    Directory of Open Access Journals (Sweden)

    Yong Weng Long

    2017-01-01

    Full Text Available This study focuses on identifying and evaluating critical parameters of various drainage configurations, arrangement, and filter which affect the efficiency of water draining system in slopes. There are a total of seven experiments with different types of homogeneous soil, drainage envelope, filter material, and quantity of pipes performed utilizing a model box with a dimension of 0.8 m × 0.8 m × 0.6 m. The pipes were orientated at 5 degrees from the horizontal. Rainfall event was introduced via a rainfall simulator with rainfall intensity of 434.1 mm/h. From the experiments performed, the expected outcomes when utilizing double pipes and geotextile as envelope filter were verified in this study. The results obtained from these experiments were reviewed and compared with Chapter 14 “Subsurface Drainage Systems” of DID’s Irrigation and Agricultural Drainage Manual of Malaysia and the European standard. It is recommended that the pipe installed in the slope could be wrapped with geotextile and in tandem with application of granular filter to minimize clogging without affecting the water discharge rate. Terzaghi’s filter criteria could be followed closely when deciding on new materials to act as aggregate filter. A caging system could be introduced as it could maintain the integrity of the drainage system and could ease installation.

  1. Efficiency of lachrymal sac drainage in newborns with dacryocystocele

    Directory of Open Access Journals (Sweden)

    Sakovich V.N.

    2016-12-01

    Full Text Available The article represents results of treatment of 14 newborns with unilateral dacryocystocele. Patients age was 7.2±0.5 days. In 9 newborns (64.3% dacryocystocele was complicated with lachrymal sac phlegmon; in 5 children (35.7% any complications were absent. Drainage of lachrymal sac through the lower lachrymal canaliculus, instillation of antibiotics, systemic antibiotic therapy in case of phlegmon were performed in all the children. Lachrymal sac washing was performed with a solution of the antibiotic ofloxacin till clear fluid evacuation. If necessary the drainage was repeated in 10 days. The drainage of lachrymal sac was successful in all the patients. 2-3 weeks after the drainage probing of nasolachrymal duct was perfomed in 4 children (28.6% including those 3 with lacrymal sac phlegmon. In 71.4% regression of dacryocystocele occurred itself. Any complications and side effects were not observed. Positive effect of the drainage, according to the authors, can be explained so that dilatation of lachrymal canaliculus before the procedure allows to eliminate Rosenmьller valve stenosis and evacuation of fluid, mucus and pus, being breeding ground for microorganisms from lachrymal sac, promotes inflammation subsiding. Authors also recommend to pay attention on prenatal diagnosis of dacryocystocele, using ultrasound investigation in the 3rd trimester of pregnancy.

  2. Percutaneous drainage with ultrasound guidance in the intensive care unit

    International Nuclear Information System (INIS)

    Kang, Doo Kyung; Won, Je Hwan; Kim, Jai Keun; Lee, Kwang Hun; Kim, Ji Hyung

    2004-01-01

    To determine the efficacy and safety of bedside percutaneous drainage procedures with ultrasound guidance in critically ill patients in the intensive care unit (ICU). Sixty five percutaneous drainage procedures performed at the bedside, in 39 ICU patients, were evaluated. All of the procedures were performed with ultrasound guidance alone. The procedures consisted of percutaneous drainage of abdominal (n=35) and pleural (n=27) fluids, percutaneous cholecystostomy (n=2) and percutaneous nephrostomy (n=1). The clinical responses were classified as 'complete response', 'partial response', 'failure' or 'undetermined'. The medical records were reviewed retrospectively to evaluate the clinical response. Technical success was achieved in 64 of the 65 procedures (98.5%). The complication rate was 13.8% (9 cases). There was no immediate procedure-related death or worsening of the clinical condition of the patients. The clinical responses after drainage were 'complete response' in 39 cases (60.9%). 'partial response' in 14 (21.9%), 'failure' in 3 (4.7%), and 'undetermined' in 8 (12.5%). Bedside drainage procedures with ultrasound guidance are effective and safe to perform when patients are too critically ill to be moved from the ICU to the angiography room

  3. Marine Pollution Prevention Act

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Marine Pollution Prevention Act of 2008 implements the International Convention for the Prevention of Pollution from Ships, including related Protocols (MARPOL)...

  4. Kookaburras and Polluted Streams.

    Science.gov (United States)

    Clark, Julie; Harrison, Terry

    2000-01-01

    Discusses the role of teachers in environmental education. Presents two simulations on water pollution in order to explore pollution of the environment and investigate the life and ecology of a native bird or investigate predator/prey relationships. (ASK)

  5. Particulate Matter (PM) Pollution

    Science.gov (United States)

    ... Environmental Protection Agency Search Search Particulate Matter (PM) Pollution Contact Us Share Most PM particles form in ... and cause serious health effects. Particulate Matter (PM) Pollution PM Basics What is PM, and how does ...

  6. Lead (Pb) Air Pollution

    Science.gov (United States)

    ... Environmental Protection Agency Search Search Lead (Pb) Air Pollution Contact Us Share As a result of EPA's ... protect aquatic and terrestrial ecosystems. Lead (Pb) Air Pollution Basic Information How does lead get in the ...

  7. Outdoor air Pollution

    CSIR Research Space (South Africa)

    Forbes, PBC

    2016-07-01

    Full Text Available regions. Ambient air pollution relates to the quality of outdoor air and will be discussed in this chapter, with a focus on the air pollutants which are typically regulated in this context internationally....

  8. Pollution of coastal seas

    Digital Repository Service at National Institute of Oceanography (India)

    Varkey, M.J.

    cities. Various types of wastes, if not properly treated, would cause serious pollution of these shallow seas endangering marine life and spoiling recreational facilities. Different polluting agents like sewage, chemicals, industrial coolants etc...

  9. Pollution of Barianwala drain and control measure

    International Nuclear Information System (INIS)

    Ahmed, K.

    1997-01-01

    In Punjab, the principal hydro spheric problems of industrial origin occur in stream and drainage channels where large industries and located. A typical example of this situation is the pollution of Barianwala drain which ultimately discharges into river Ravi. This drain is at present serving as an industrial effluent carrier for fourteen polluting industries, the majority of which are of pulp and paper type. The main objective of this study is to investigate the impact of their effluents on the drain and to suggest measures for control so as to save river Ravi from further pollution. The total effluent discharges from these industries on average basis is 86640 m-3/3. The range of their average characteristics being: pH 7.0 to 7.8, total solids 834 to 2918 mg/L suspended solids 118 to 1096 mg/L total dissolved, solids 08 to 1293 mg/L BODs 9564 to 2000 mg/L and COD 1755 to 3494 mg/L. The values are indicative of very high pollution entering the drain. Condition in the drain was investigated at the upstream and downstream sides and results of the investigations have been summarized. 96 percent increase in BOD and COD load at downstream in attributed to industrial effluent discharges. To certain extent wastewater reuse activity like manufacturing of crude paper board from the sedimented fibrous materials and extraction of oil by local population and going on at site at an increasing rate. Investigations revealed that pollution load of the drain can be reduced to certain extent, if the industries are asked to install sedimentation tanks or primary setting tanks within their premises. Because the majority of the plants are of pulp and paper type, NEQS levels can be achieved by a combined treatment plant consisting of anaerobic WSPs followed by aerated Lagoons at the downstream side. (author)

  10. Air Pollution Training Programs.

    Science.gov (United States)

    Public Health Service (DHEW), Rockville, MD.

    This catalog lists the universities, both supported and not supported by the Division of Air Pollution, which offer graduate programs in the field of air pollution. The catalog briefly describes the programs and their entrance requirements, the requirements, qualifications and terms of special fellowships offered by the Division of Air Pollution.…

  11. Water pollution biology

    Energy Technology Data Exchange (ETDEWEB)

    Mason, C.F. [University of Essex, Colchester (United Kingdom). Dept. of Biology

    1996-12-31

    Chapter 4 of this book describes the effects of major types of pollutants on aquatic life. These are: organic pollution, eutrophication, acidification, toxic chemicals, oil, and radioactivity. The review includes an description of some of the methods of assessing the biological impacts of pollution. 50 refs., 8 figs., 3 tabs.

  12. Water Pollution, Teachers' Edition.

    Science.gov (United States)

    Lavaroni, Charles W.; And Others

    One of three in a series about pollution, this teacher's guide for a unit on water pollution is designed for use in junior high school grades. It offers suggestions for extending the information and activities contained in the textual material for students. Chapter 1 discusses the problem of water pollution and involves students in processes of…

  13. The Other Water Pollution

    Science.gov (United States)

    Barton, Kathy

    1978-01-01

    Nonpoint source pollution, water pollution not released at one specific identifiable point, now accounts for 50 percent of the nation's water pollution problem. Runoff is the primary culprit and includes the following sources: agriculture, mining, hydrologic modifications, and urban runoff. Economics, legislation, practices, and management of this…

  14. Air Pollution, Teachers' Edition.

    Science.gov (United States)

    Lavaroni, Charles W.; O'Donnell, Patrick A.

    One of three in a series about pollution, this teacher's guide for a unit on air pollution is designed for use in junior high school grades. It offers suggestions for extending the information and activities contained in the textual material for students. Chapter 1 discusses the problem of air pollution and involves students in processes of…

  15. Indoor Air Pollution

    Science.gov (United States)

    We usually think of air pollution as being outdoors, but the air in your house or office could also be polluted. Sources of indoor pollution ... is known as sick building syndrome. Usually indoor air quality problems only cause discomfort. Most people feel ...

  16. Decomposing functional trait associations in a Chinese subtropical forest.

    Science.gov (United States)

    Li, Xuefei; Pei, Kequan; Kéry, Marc; Niklaus, Pascal A; Schmid, Bernhard

    2017-01-01

    Functional traits, properties of organisms correlated with ecological performance, play a central role in plant community assembly and functioning. To some extents, functional traits vary in concert, reflecting fundamental ecological strategies. While "trait syndromes" characteristic of e.g. fast-growing, early-successional vs. competitive, late-successional species are recognized in principle, less is known about the environmental and genetic factors at the source of trait variation and covariation within plant communities. We studied the three leaf traits leaf half-life (LHL), leaf mass per area (LMA) and nitrogen concentration in green leaves (Ngreen) and the wood trait wood density (WD) in 294 individuals belonging to 45 tree or shrub species in a Chinese subtropical forest from September 2006 to January 2009. Using multilevel ANOVA and decomposition of sums of products, we estimated the amount of trait variation and covariation among species (mainly genetic causes), i.e. plant functional type (deciduous vs. evergreen species), growth form (tree vs. shrub species), family/genus/species differences, and within species (mainly environmental causes), i.e. individual and season. For single traits, the variation between functional types and among species within functional types was large, but only LMA and Ngreen varied significantly among families and thus showed phylogenetic signal. Trait variation among individuals within species was small, but large temporal variation due to seasonal effects was found within individuals. We did not find any trait variation related to soil conditions underneath the measured individuals. For pairs of traits, variation between functional types and among species within functional types was large, reflecting a strong evolutionary coordination of the traits, with LMA, LHL and WD being positively correlated among each other and negatively with Ngreen. This integration of traits was consistent with a putative stem-leaf economics spectrum

  17. The culture of Tilapia species in tropical and subtropical conditions

    Directory of Open Access Journals (Sweden)

    De Maeseneer, J.

    1984-01-01

    Full Text Available Although since long known by African fishermen it is only in the last 40 years that Tilapia has been recognized as one of the most promising groups of fish species for culture. The initial successes for culture in Central Africa were followed by several failures mainly because of excessive breeding and early sexual maturity in shallow waterbodies as ponds. From the present knowledge it appears that tilapia has a great future for increasing the productivity in unmanaged environments as man-made lakes and reservoirs primarily destined for the production of hydro-electricity. Careful stocking of paddies and irrigation canals can solve a number of biological problems associated with them and provide an additional though valuable high-protein food source. Great future offers also the culture of tilapia in traditional pond culture especially in polyculture with members of the carp family, mullets and waterfowl in areas of the tropical and subtropical belt. In coastal ponds T, mossambica is a valuable species for sanitary reasons. The culture of tilapia in small farm ponds often meets with failure owing to excessive breeding and stunting unless the all-male technique can be applied through government input and encouragement. As a rule this type of production will be the least attractive. Although Tilapia spp. do not achieve the largest individu al growth their tolerance towards adverse conditions and their acceptance of a wide variety of foodstuffs, primarily waste products from agriculture, their resistance to diseases and (at least in some species their tolerance of crowded environments make them suitable subject for cultures in raceways, circular tanks and cages. Through heavy inputs of water and pelletized feeds nearly incredible annual yields as 2 000 tonnes per ha of water surface (1 and more were realized. This means that this type of production surpasses by far any other known form of animal husbandry but it needs high technological input (thus

  18. Stormwater quality from extensive green roofs in a subtropical region

    Science.gov (United States)

    Onis Pessoa, Jonas; Allasia, Daniel; Tassi, Rutineia; Vaz Viega, Juliana; Fensterseifer, Paula

    2016-04-01

    Green roofs have increasingly become an integral part of urban environments, mainly due to their aesthetic benefits, thermal comfort and efficiency in controlling excess runoff. However, the effects of this emerging technology in the qualitative characteristics of rainwater is still poorly understood. In this study was evaluated the effect of two different extensive green roofs (EGRs) and a traditional roof built with corrugated fiber cement sheets (control roof) in the quality of rainwater, in a subtropical climate area in the city of Santa Maria, in southern Brazil. The principal variant between the two EGRs were the type of plant species, time since construction, soil depth and the substrate characteristics. During the monitoring period of the experiment, between the months of April and December of 2015 fourteen rainfall events were selected for qualitative analysis of water from the three roofs and directly from rainfall. It was analyzed physical (turbidity, apparent color, true color, electrical conductivity, total solids, dissolved solids, suspended solids and temperature), chemical (pH, phosphate, total nitrogen, nitrate, nitrite, chloride, sulfate, BOD, iron and total hardness), heavy metals (copper, zinc, lead and chromium) and microbiological parameters (total coliforms and E. coli). It was also characterized the substrates used in both extensive green roofs. The results showed that the quality of the water drained from EGR s was directly influenced by their substrates (in turn containing significant levels of nutrients, organic matter and some metals). The passage of rainwater through green roofs and control roof resulted in the elevation of pH, allowing the conversion of the slightly acidic rainfall into basic water. Similarly, on both types of roofs occurred an increase of the values of most of the physical, chemical and microbiological parameters compared to rainwater. This same trend was observed for heavy metals, although with a much smaller degree

  19. Carbon stocks assessment in subtropical forest types of Kashmir Himalayas

    International Nuclear Information System (INIS)

    Shaheen, H.; Khan, R.W.A.; Hussain, K.; Ullah, T.S.; Mehmood, A.

    2016-01-01

    Estimation of carbon sequestration in forest ecosystem is necessary to mitigate impacts of climate change. Current research project was focused to assess the Carbon contents in standing trees and soil of different subtropical forest sites in Kashmir. Tree biomass was estimated by using allometric equations whereas Soil carbon was calculated by Walkey-Black titration method. Total carbon stock was computed as 186.27 t/ha with highest value of 326 t/ha recorded from Pinus roxburghii forest whereas lowest of 75.86 t/ha at mixed forest. Average biomass carbon was found to be 151.38 t/ha with a maximum value of 294.7 t/ha and minimum of 43.4 t/ha. Pinus roxburghii was the most significant species having biomass value of 191.8 t/ha, followed by Olea cuspidata (68.9 t/ha), Acacia modesta (12.71 t/ha), Dalbergia sissoo (12.01 t/ha), Broussonetia papyrifera (5.93 t/ha), Punica granatum (2.27 t/ha), Mallotus philippensis (2.2 t/ha), Albizia lebbeck (1.8t/ha), Ficus palmata (1.51 t/ha), Acacia arabica (1.4 t/ha), Melia azedarach, (1.14 t/ha) and Ficus carica (1.07 t/ha) respectively. Recorded value of tree density was 492/ha; average DBH was 87.27 cm; tree height was 13.3m; and regeneration value was 83 seedlings/ha. Soil carbon stocks were found to be 34.89 t/ha whereas agricultural soil carbon was calculated as 27.18 t/ha. Intense deforestation was represented by a stump density of 147.4/ha. The results of Principal Component Analysis (PCA) revealed the distinct species clusters on the basis of location, biomass and Carbon stock values. Pinus roxburghii and Olea cuspidata were found to be the major contributors of carbon stock having maximum vector lengths in the PCA Biplot. Forest in the area needs to be managed in a sustainable manner to increase its carbon sequestration potential. (author)

  20. Serological Survey of Hantavirus in Inhabitants from Tropical and Subtropical Areas of Brazil

    Directory of Open Access Journals (Sweden)

    Felipe Alves Morais

    2016-01-01

    Full Text Available Brazil has reported more than 1,600 cases of hantavirus cardiopulmonary syndrome (HPS since 1993, with a 39% rate of reported fatalities. Using a recombinant nucleocapsid protein of Araraquara virus, we performed ELISA to detect IgG antibodies against hantavirus in human sera. The aim of this study was to analyze hantavirus antibody levels in inhabitants from a tropical area (Amazon region in Rondônia state and a subtropical (Atlantic Rain Forest region in São Paulo state, Brazil. A total of 1,310 serum samples were obtained between 2003 and 2008 and tested by IgG-ELISA, and 82 samples (6.2%, of which 62 were from the tropical area (5.8% and 20 from the subtropical area (8.3%, tested positive. Higher levels of hantavirus antibody were observed in inhabitants of the populous subtropical areas compared with those from the tropical areas in Brazil.

  1. Integration of Rs/gis for Surface Water Pollution Risk Modeling. Case Study: Al-Abrash Syrian Coastal Basin

    Science.gov (United States)

    Yaghi, Y.; Salim, H.

    2017-09-01

    Recently the topic of the quality of surface water (rivers - lakes) and the sea is an important topics at different levels. It is known that there are two major groups of pollutants: Point Source Pollution (PSP) and non-point Source pollution (NPSP). Historically most of the surface water pollution protection programs dealing with the first set of pollutants which comes from sewage pipes and factories drainage. With the growing need for current and future water security must stand on the current reality of the coastal rivers basin in terms of freshness and cleanliness and condition of water pollution. This research aims to assign the NPS pollutants that reach Al Abrash River and preparation of databases and producing of risk Pollution map for NPS pollutants in order to put the basin management plan to ensure the reduction of pollutants that reach the river. This research resulted of establishing of Databases of NPSP (Like pesticides and fertilizers) and producing of thematic maps for pollution severity and pollution risk based on the pollution models designed in GIS environment and utilizing from remote sensing data. Preliminary recommendations for managing these pollutants were put.

  2. INTEGRATION OF RS/GIS FOR SURFACE WATER POLLUTION RISK MODELING. CASE STUDY: AL-ABRASH SYRIAN COASTAL BASIN

    Directory of Open Access Journals (Sweden)

    Y. Yaghi

    2017-09-01

    Full Text Available Recently the topic of the quality of surface water (rivers – lakes and the sea is an important topics at different levels. It is known that there are two major groups of pollutants: Point Source Pollution (PSP and non-point Source pollution (NPSP. Historically most of the surface water pollution protection programs dealing with the first set of pollutants which comes from sewage pipes and factories drainage. With the growing need for current and future water security must stand on the current reality of the coastal rivers basin in terms of freshness and cleanliness and condition of water pollution. This research aims to assign the NPS pollutants that reach Al Abrash River and preparation of databases and producing of risk Pollution map for NPS pollutants in order to put the basin management plan to ensure the reduction of pollutants that reach the river. This research resulted of establishing of Databases of NPSP (Like pesticides and fertilizers and producing of thematic maps for pollution severity and pollution risk based on the pollution models designed in GIS environment and utilizing from remote sensing data. Preliminary recommendations for managing these pollutants were put.

  3. Vacuum-assisted drainage in cardiopulmonary bypass: advantages and disadvantages

    Science.gov (United States)

    de Carvalho Filho, Élio Barreto; Marson, Fernando Augusto de Lima; da Costa, Loredana Nilkenes Gomes; Antunes, Nilson

    2014-01-01

    Systematic review of vacuum assisted drainage in cardiopulmonary bypass, demonstrating its advantages and disadvantages, by case reports and evidence about its effects on microcirculation. We conducted a systematic search on the period 1997-2012, in the databases PubMed, Medline, Lilacs and SciELO. Of the 70 selected articles, 26 were included in the review. Although the vacuum assisted drainage has significant potential for complications and requires appropriate technology and professionalism, prevailed in literature reviewed the concept that vacuum assisted drainage contributed in reducing the rate of transfusions, hemodilutions, better operative field, no significant increase in hemolysis, reduced complications surgical, use of lower prime and of smaller diameter cannulas. PMID:25140478

  4. Urban drainage design and climate change adaptation decision making

    DEFF Research Database (Denmark)

    Zhou, Qianqian

    century, the design objectives of urban drainage systems also include elements such as environmental protection and amenity values. Among the objectives, flood protection has received much attention in recent years as a result of increasing flood hazards and risks due to climate change impacts. Although...... new principles and approaches for assessment of urban drainage adaptation measures under climate change impacts. The thesis describes a new framework for design and analysis of urban drainage that accurately assesses hazards and vulnerabilities of urban areas and quantifies the present and future...... risks based on projections of climate change and city development. Furthermore, this framework can be utilized to identify cost-effective measures that can reduce the overall flood risk to an acceptable level considering both costs and benefits of adaptation. The framework is mainly based...

  5. Evaluation of the sustainability of road drainage systems

    Science.gov (United States)

    García-Diez, Iván; Palencia, Covadonga; Fernández Raga, María

    2017-04-01

    Water is the most erosive agent that exists on the linear structures, because they are constantly subjected to outdoor condition like irregular infiltration, frosts and different rain intensities. Another variables that highly influence in the entire lifetime of a natural drainage system are the spatial and temporal variability of the rainfall, the soil, the vegetation cover and the design. All this factors are affecting the vulnerability of the clearings and embankments, by wearing away the weakest materials which surround the roads or train rails, producing erosion and very bumpy surfaces. The result is that the original pattern, developped to disminished the lost of soil, is not properly working and it cannot eliminate water, with the consequence destruction of the linear structure after several rainfall periods, and the accumulation of material down slope. The propose of this research focuses on analysing the drainage systems used in spanish roads and railways lines. For this purpose, a revision of the literature has been done, and the main drainage solutions have been recovered, carrying out an evaluation of them from an environmental point of view. This procedure has been requested by several authors in the past (Nwa, E.U. & Twocock, J.G., 1969; Goulter, I.C., 1992), together with the need of designing a more sustainable drainage system. The final objective of this complete revision is to compare objetively the designs to valuate them in order to develop a new drainage patter which minimize the erosion, increasing the durability and effectiveness of the drainage system. For this purpose, it is neccesary to assure that all the systems will be compare under similar parameters of flow rate, vegetation, substrate, lenght, slope and total section. Only the channels pattern and water distribution will change. The analysis has been done following Liu, H. & Zhu, X.B., (2012), who pointed out that the main parameters to take into account to select a road drainage

  6. Measure Guideline: Guidance on Taped Insulating Sheathing Drainage Planes

    Energy Technology Data Exchange (ETDEWEB)

    Grin, A. [Building Science Corporation, Somerville, MA (United States); Lstiburek, J. [Building Science Corporation, Somerville, MA (United States)

    2014-09-01

    The goal of this research is to provide durable and long-term water management solutions using exterior insulating sheathing as part of the water management system. It is possible to tape or seal the joints in insulating sheathing to create a drainage plane and even an air control layer. There exists the material durability component of the tape as well as the system durability component being the taped insulating sheathing as the drainage plane. This measure guideline provides best practice and product recommendations from the interviewed contractors and homebuilders who collectively have a vast amount of experience. Three significant issues were discussed with the group, which are required to make taped insulating sheathing a simple, long-term, and durable drainage plane: horizontal joints should be limited or eliminated wherever possible; where a horizontal joint exists use superior materials; and frequent installation inspection and regular trade training are required to maintain proper installation.

  7. Drainage filters and constructed wetlands to mitigate sitespecific nutrient losses

    DEFF Research Database (Denmark)

    Kjærgaard, Charlotte; Canga, Eriona; Heckrath, Goswin Johann

    2012-01-01

    Despite substantial efforts, the leaching of nutrients from agricultural land is still a serious and costly environmental problem in Denmark and elsewhere. The quality goals of the European Water Framework Directive (WFD) for the aquatic environment require a substantial reduction of diffuse...... losses and 45-60% of total N losses. Hence, for a large number of recipients, drainage water nutrient loads has a major impact on water quality, however, mitigation options targeting subsurface drainage are lacking. An end-of-pipe drainage filter solution offers the benefits of a targeted measure...... as surface-flow and subsurface flow constructed wetlands. Various natural and industrial P filter substrates are tested towards P sorption properties, as well as hydraulic efficiency and P retention efficiency during variable flow regimes. A major challenge is to reduce comparatively low P concentrations...

  8. Electronic versus traditional chest tube drainage following lobectomy

    DEFF Research Database (Denmark)

    Lijkendijk, Marike; Licht, Peter B; Neckelmann, Kirsten

    2015-01-01

    OBJECTIVES: Electronic drainage systems have shown superiority compared with traditional (water seal) drainage systems following lung resections, but the number of studies is limited. As part of a medico-technical evaluation, before change of practice to electronic drainage systems for routine...... was delegated to staff nurses. Data were analysed by Cox proportional hazard regression model adjusting for lung function, gender, age, BMI, video-assisted thoracic surgery (VATS) or open surgery and presence of incomplete fissure or pleural adhesions. Time was distinguished as possible (optimal) and actual...... time for chest tube removal, as well as length of hospitalization. RESULTS: A total of 105 patients were randomized. We found no significant difference between the electronic group and traditional group in optimal chest tube duration (HR = 0.83; 95% CI: 0.55-1.25; P = 0.367), actual chest tube duration...

  9. Sustainable Remediation of Legacy Mine Drainage: A Case Study of the Flight 93 National Memorial

    Science.gov (United States)

    Emili, Lisa A.; Pizarchik, Joseph; Mahan, Carolyn G.

    2016-03-01

    Pollution from mining activities is a global environmental concern, not limited to areas of current resource extraction, but including a broader geographic area of historic (legacy) and abandoned mines. The pollution of surface waters from acid mine drainage is a persistent problem and requires a holistic and sustainable approach to addressing the spatial and temporal complexity of mining-specific problems. In this paper, we focus on the environmental, socio-economic, and legal challenges associated with the concurrent activities to remediate a coal mine site and to develop a national memorial following a catastrophic event. We provide a conceptual construct of a socio-ecological system defined at several spatial, temporal, and organizational scales and a critical synthesis of the technical and social learning processes necessary to achieving sustainable environmental remediation. Our case study is an example of a multi-disciplinary management approach, whereby collaborative interaction of stakeholders, the emergence of functional linkages for information exchange, and mediation led to scientifically informed decision making, creative management solutions, and ultimately environmental policy change.

  10. Hydrochemistry, mineralogy and sulfur isotope geochemistry of acid mine drainage at the Mt. Morgan mine environment, Queensland, Australia

    International Nuclear Information System (INIS)

    Edraki, M.; Golding, S.D.; Baublys, K.A.; Lawrence, M.G.

    2005-01-01

    Mineralogical, hydrochemical and S isotope data were used to constrain hydrogeochemical processes that produce acid mine drainage from sulfidic waste at the historic Mount Morgan Au-Cu mine, and the factors controlling the concentration of SO 4 and environmentally hazardous metals in the nearby Dee River in Queensland, Australia. Some highly contaminated acid waters, with metal contents up to hundreds of orders of magnitude greater than the Australia-New Zealand environmental standards, by-pass the water management system at the site and drain into the adjacent Dee River. Mine drainage precipitates at Mt. Morgan were classified into 4 major groups and were identified as hydrous sulfates and hydroxides of Fe and Al with various contents of other metals. These minerals contain adsorbed or mineralogically bound metals that are released into the water system after rainfall events. Sulfate in open pit water and collection sumps generally has a narrow range of S isotope compositions (δ 34 S = 1.8-3.7%o) that is comparable to the orebody sulfides and makes S isotopes useful for tracing SO 4 back to its source. The higher δ 34 S values for No. 2 Mill Diesel sump may be attributed to a difference in the source. Dissolved SO 4 in the river above the mine influence and 20 km downstream show distinctive heavier isotope compositions (δ 34 S = 5.4-6.8%o). The Dee River downstream of the mine is enriched in 34 S (δ 34 S = 2.8-5.4%o) compared with mine drainage possibly as a result of bacterial SO 4 reduction in the weir pools, and in the water bodies within the river channel. The SO 4 and metals attenuate downstream by a combination of dilution with the receiving waters, SO 4 reduction, and the precipitation of Fe and Al sulfates and hydroxides. It is suggested here that in subtropical Queensland, with distinct wet and dry seasons, temporary reducing environments in the river play an important role in S isotope systematics

  11. Exocrine drainage in vascularized pancreas transplantation in the new millennium

    Science.gov (United States)

    El-Hennawy, Hany; Stratta, Robert J; Smith, Fowler

    2016-01-01

    The history of vascularized pancreas transplantation largely parallels developments in immunosuppression and technical refinements in transplant surgery. From the late-1980s to 1995, most pancreas transplants were whole organ pancreatic grafts with insulin delivery to the iliac vein and diversion of the pancreatic ductal secretions to the urinary bladder (systemic-bladder technique). The advent of bladder drainage revolutionized the safety and improved the success of pancreas transplantation. However, starting in 1995, a seismic change occurred from bladder to bowel exocrine drainage coincident with improvements in immunosuppression, preservation techniques, diagnostic monitoring, general medical care, and the success and frequency of enteric conversion. In the new millennium, pancreas transplants are performed predominantly as pancreatico-duodenal grafts with enteric diversion of the pancreatic ductal secretions coupled with iliac vein provision of insulin (systemic-enteric technique) although the systemic-bladder technique endures as a preferred alternative in selected cases. In the early 1990s, a novel technique of venous drainage into the superior mesenteric vein combined with bowel exocrine diversion (portal-enteric technique) was designed and subsequently refined over the next ≥ 20 years to re-create the natural physiology of the pancreas with first-pass hepatic processing of insulin. Enteric drainage usually refers to jejunal or ileal diversion of the exocrine secretions either with a primary enteric anastomosis or with an additional Roux limb. The portal-enteric technique has spawned a number of newer and revisited techniques of enteric exocrine drainage including duodenal or gastric diversion. Reports in the literature suggest no differences in pancreas transplant outcomes irrespective of type of either venous or exocrine diversion. The purpose of this review is to examine the literature on exocrine drainage in the new millennium (the purported

  12. Meta-analysis of prophylactic abdominal drainage in pancreatic surgery.

    Science.gov (United States)

    Hüttner, F J; Probst, P; Knebel, P; Strobel, O; Hackert, T; Ulrich, A; Büchler, M W; Diener, M K

    2017-05-01

    Intra-abdominal drains are frequently used after pancreatic surgery whereas their benefit in other gastrointestinal operations has been questioned. The objective of this meta-analysis was to compare abdominal drainage with no drainage after pancreatic surgery. PubMed, the Cochrane Library and Web of Science electronic databases were searched systematically to identify RCTs comparing abdominal drainage with no drainage after pancreatic surgery. Two independent reviewers critically appraised the studies and extracted data. Meta-analyses were performed using a random-effects model. Odds ratios (ORs) were calculated to aggregate dichotomous outcomes, and weighted mean differences for continuous outcomes. Summary effect measures were presented together with their 95 per cent confidence intervals. Some 711 patients from three RCTs were included. The 30-day mortality rate was 2·0 per cent in the drain group versus 3·4 per cent after no drainage (OR 0·68, 95 per cent c.i. 0·26 to 1·79; P = 0·43). The morbidity rate was 65·6 per cent in the drain group and 62·0 per cent in the no-drain group (OR 1·17, 0·86 to 1·60; P = 0·31). Clinically relevant pancreatic fistulas were seen in 11·5 per cent of patients in the drain group and 9·5 per cent in the no-drain group. Reinterventions, intra-abdominal abscesses and duration of hospital stay also showed no significant difference between the two groups. Pancreatic resection with, or without abdominal drainage results in similar rates of mortality, morbidity and reintervention. © 2017 BJS Society Ltd Published by John Wiley & Sons Ltd.

  13. Implementation of a drainage information, analysis and management system

    Directory of Open Access Journals (Sweden)

    J.N. Meegoda

    2017-04-01

    Full Text Available An integrated drainage information, analysis and management system (DIAMS was developed and implemented for the New Jersey Department of Transportation (NJDOT. The purpose of the DIAMS is to provide a useful tool for managers to evaluate drainage infrastructure, to facilitate the determination of the present costs of preserving those infrastructures, and to make decisions regarding the optimal use of their infrastructure budgets. The impetus for DIAMS is the culvert information management system (CIMS, which is developed to manage the data for culvert pipes. DIAMS maintains and summarizes accumulated inspection data for all types of drainage infrastructure assets, including pipes, inlet/outlet structures, outfalls and manufactured treatment devices. DIAMS capabilities include identifying drainage infrastructure, maintaining inspection history, mapping locations, predicting service life based on the current condition states, and assessing present asset value. It also includes unit cost values of 72 standard items to estimate the current cost for new assets with the ability to adjust for future inflation. In addition, DIAMS contains several different repair, rehabilitation and replacement options to remedy the drainage infrastructure. DIAMS can analyze asset information and determine decisions to inspect, rehabilitate, replace or do nothing at the project and network levels by comparing costs with risks and failures. Costs may be optimized to meet annual maintenance budget allocations by prioritizing drainage infrastructure needing inspection, cleaning and repair. DIAMS functional modules include vendor data uploading, asset identification, system administration and financial analysis. Among the significant performance feature of DIAMS is its proactive nature, which affords decision makers the means of conducting a comprehensive financial analysis to determine the optimal proactive schedule for the proper maintenance actions and to prioritize them

  14. Environmental pollution from new chemical pollutants

    International Nuclear Information System (INIS)

    Ahmed, K.

    1995-01-01

    New chemical pollutants have entered the environment because of industrialisation, urbanization and developments. The new pollutants include polymers, plasticizers, polychlorinated biphenyls, acrylonitriles, detergents, lead, dioxins and pesticides. Investigations showed substational amount of their presence in the environment. Pesticides and polymers can be controlled by using photo sensitizers. Lead pollution in ambient air can be controlled by reducing lead content in the gasoline. Detergents can be controlled by switching over the manufacturing process from ABS to LAS. Dioxins can be controlled by incinerating the chlorinated waste above 1200 C. (author)

  15. Effects of different N sources on riverine DIN export and retention in a subtropical high-standing island, Taiwan

    Science.gov (United States)

    Huang-Chuan, Jr.; Lee, Tsung-Yu; Lin, Teng-Chiu; Hein, Thomas; Lee, Li-Chin; Shih, Yu-Ting; Kao, Shuh-Ji; Shiah, Fuh-Kwo; Lin, Neng-Huei

    2016-03-01

    highly disturbed watersheds are very high, 0.42-0.53, suggesting that much of the N input is transported downstream directly, and urges the need to increase the proportion of households connected to a sewage system and improve the effectiveness of wastewater treatment systems. The increases in the riverine DIN export ratio along the gradient of human disturbance also suggest a gradient in N saturation in subtropical Taiwan. Our results help to improve our understanding of factors controlling riverine DIN export and provide empirical evidence that calls for sound N emission/pollution control measures.

  16. Effects of different N sources on riverine DIN export and retention in a subtropical high-standing island, Taiwan.

    Science.gov (United States)

    Huang, Jr-Chuan; Lee, Tsung-Yu; Lin, Teng-Chiu; Hein, Thomas; Lee, Li-Chin; Shih, Yu-Ting; Kao, Shuh-Ji; Shiah, Fuh-Kwo; Lin, Neng-Huei

    the highly disturbed watersheds are very high, 0.42-0.53, suggesting that much of the N input is transported downstream directly, and urges the need to increase the proportion of households connected to a sewage system and improve the effectiveness of wastewater treatment systems. The increases in the riverine DIN export ratio along the gradient of human disturbance also suggest a gradient in N saturation in subtropical Taiwan. Our results help to improve our understanding of factors controlling riverine DIN export and provide empirical evidence that calls for sound N emission/pollution control measures.

  17. Estimation of sediment residence times in subtropical highland catchments of central Mexico combining river gauging and fallout radionuclides

    Science.gov (United States)

    Evrard, Olivier; Némery, Julien; Gratiot, Nicolas; Duvert, Clément; Lefèvre, Irène; Ayrault, Sophie; Esteves, Michel; Bonté, Philippe

    2010-05-01

    Subtropical regions of the world are affected by intense soil erosion associated with deforestation, overgrazing and cropping intensification. This land degradation leads to important on-site (e.g. decrease in soil fertility) and off-site impacts (e.g. reservoir sedimentation, water pollution). This study determined the mean sediment residence times in soils and rivers of three catchments (3 - 12 km²) with contrasted land uses (i.e. cropland, forests, rangelands, extended gully networks) located in highlands of the transvolcanic belt of central Mexico. Calculations were based on rainfall and river gauging as well as on fallout radionuclide measurements (Be-7, Cs-137, Pb-210). Atmospheric deposition of Be-7 and Pb-210 was estimated based on the analysis of rainfall precipitated samples. Rainfall samples were collected all throughout the rainy season in order to take account of the temporal variations of the radionuclide fluxes. Furthermore, sampling of suspended sediment was conducted at the outlet of each catchment during most of the storms that occurred throughout the 2009 rainy season. Be-7, Cs-137 and Pb-210 concentrations of this sediment were determined by gamma-spectrometry. A two-box balance model was then used to estimate the sediment residence time and the inventory of radionuclides in the three selected catchments. This model subdivided each catchment into two boxes: (i) a "soil-box" characterised by low transport velocities and hence long radionuclide residence times and (ii) a "river-box" covering the river surface and its surroundings characterised by quicker exchanges and shorter radionuclide residence times. Input and output fluxes of sediment and radionuclides were taken into account in each box. Radioactive decay during the residence time of sediment was also considered. The mean residence time of sediment in soils ranged between 13,300 - 28,500 years. In contrast, sediment residence time in rivers was much shorter, fluctuating between 28 and 393

  18. Nutrient (N, P, Si) transfers in the subtropical Red River system (China and Vietnam): Modelling and budget of nutrient sources and sinks

    Science.gov (United States)

    Le, Thi Phuong Quynh; Gilles, Billen; Garnier, Josette; Sylvain, Théry; Denis, Ruelland; Anh, Nghiem Xuan; Minh, Chau Van

    2010-02-01

    The Red River system, which has a population density that varies from 80 to over 1000 inhabitants km -2 in the different sectors of its watershed, is a typical example of a subtropical system experiencing high human pressure. A monthly survey of nutrient concentration was conducted at the outlet of the three main tributaries (Da, Thao and Lo) and at Hanoi on the main branch of the Red River in the upper part of the delta. Samples from headwater streams or irrigation channels draining homogeneous land use classes also were analysed. A GIS database describing the characteristics of the watershed in terms of morphology, climate, land use and population has been established. This served as the basis for implementing the Seneque/Riverstrahler model, which allowed calculation of nutrient transfers and transformations along the whole drainage network of the Red River system. The model was validated using the measured nutrient concentrations obtained during the survey and was used to establish an overall description and a comprehensive budget of nutrient transfer, retention and delivery for the three main sub-basins and the upper part of the delta upstream from Hanoi.

  19. Interannual and Decadal Changes in Salinity in the Oceanic Subtropical Gyres

    Science.gov (United States)

    Bulusu, Subrahmanyam

    2017-04-01

    There is evidence that the global water cycle has been undergoing an intensification over several decades as a response to increasing atmospheric temperatures, particularly in regions with skewed evaporation - precipitation (E-P) patterns such as the oceanic subtropical gyres. Moreover, observational data (rain gauges, etc.) are quite sparse over such areas due to the inaccessibility of open ocean regions. In this work, a comparison of observational and model simulations are conducted to highlight the potential applications of satellite derived salinity from NASA Aquarius Salinity mission, NASA Soil Moisture and Ocean Salinity (SMOS), and ESA's Soil Moisture Active Passive (SMAP). We explored spatial and temporal salinity changes (and trends) in surface and subsurface in the oceanic subtropical gyres using Argo floats salinity data, Simple Ocean Data Assimilation (SODA) reanalysis, Estimating the Circulations & Climate of the Ocean GECCO (German ECCO) model simulations, and Hybrid Coordinate Ocean Model (HYCOM). Our results based on SODA reanalysis reveals that a positive rising trend in sea surface salinity in the subtropical gyres emphasizing evidence for decadal intensification in the surface forcing in these regions. Zonal drift in the location of the salinity maximum of the south Pacific, north Atlantic, and south Indian regions implies a change in the mean near-surface currents responsible for advecting high salinity waters into the region. Also we found out that an overall salinity increase within the mixed layer, and a subsurface salinity decrease at depths greater than 200m in the global subtropical gyres over 61 years. We determine that freshwater fluxes at the air-sea interface are the primary drivers of the sea surface salinity (SSS) signature over these open ocean regions by quantifying the advective contribution within the surface layer. This was demonstrated through a mixed layer salinity budget in each subtropical gyre based on the vertically

  20. Spontaneous drainage in syringomyelia: magnetic resonance imaging findings

    International Nuclear Information System (INIS)

    Bogdanov, E.I.; Mendelevich, E.G.; Ibatullin, M.M.

    2000-01-01

    We present five cases of syringomyelia associated with Chiari I or other causes of partial obstructions at the cervicomedullary junction, with spontaneous disruption of the wall of a cervical syrinx and formation of a communication between the cavity and the subarachnoid space, shown on axial MRI. MRI can be used to investigate the hydrodynamics, showing the liquid inside the disrupted syrinx wall and the pathway of drainage. The finding of spontaneous drainage may be important for understanding the pathogenesis of syringomyelia and may be helpful for choosing a surgical approach. (orig.)

  1. Producing the Drainage Layer Database for North America (WATGRID)

    Science.gov (United States)

    Seglenieks, F. R.; Soulis, E. D.; Mackay, M.

    2004-05-01

    The hydrological component of coupled atmospheric-hydrologic models requires the creation of the drainage layer database (i.e. stream channel network, slopes, etc.). This is often done from a digital elevation model (DEM) using a lowest neighbour approach, however this method can lead to incorrect flow directions especially with large grid sizes. Using a technique developed by the Waterloo Hydrology Lab at the University of Waterloo, the drainage layer database for North America was produced at varying resolutions for a project called WATGRID. The projection used was based on the polar stereographic projection used by the Canadian Regional Climate Model (CRCM) for the Mackenzie Basin GEWEX Study (MAGS) at resolutions of 500, 200, and 51 km. The procedure involved first obtaining the best possible DEM and land cover map. Currently the best available public domain data set for elevation is the GTOPO30 database and for land cover it is the Global Land Cover Characterization database. Both of these data sets have a resolution of approximately 1 km and are available for all of North America from the USGS. The DEM was then verified so that it produced the correct derived river channels. To do this the river network derived from the DEM was compared to the river networks available in vector format from base maps of North America. The DEM was modified until the derived stream network produced drainage areas within 5% of measured values for all basins over 500 000 km2. Once the DEM was verified, the program WATMAP was used to derive the drainage layer database for various resolutions. This program divides the data sets into grid squares based on the required projection and resolution, then for each grid square it calculates the inflows and outflows around the perimeter of the grid square. From this, the program can determine the maximum outflow and inflow to derive parameters such as main drainage direction, secondary drainage direction, and channel slope. The program also

  2. Quaternary Reorganization of North American Mid-continent Drainage Systems

    Science.gov (United States)

    Carson, E. C.; Rawling, J. E., III; Attig, J. W.; Bates, B. R.

    2013-12-01

    Identification of ancestral drainage systems in the North American mid-continent has been a topic of research and debate among geologists since the middle of the 19th Century. Over time our understanding of the significance of Quaternary glaciations in reshaping drainage patterns has grown. The ancestral Teays River, which drained large areas of the central Appalachians and flowed westward across Indiana and western Illinois, was dammed multiple times by Quaternary glaciers before finally being rerouted to the course of the modern central Ohio River. Similarly, the northward-flowing ancestral Pittsburgh River was dammed by pre-Illinoian glaciers; subsequent stream piracy converted this river system into the modern Allegheny, Monongahela and uppermost Ohio Rivers. Deposits and geomorphic features along the westward-flowing lower Wisconsin River indicate that the modern upper Mississippi River and Wisconsin River may have experienced a similar history of ice blockage, stream piracy, and radical rerouting. Coring into the Bridgeport strath terrace along the lower Wisconsin River reveals that the bedrock surface dips to the east, indicating the valley was cut by an eastward-flowing river. We believe the most likely scenario following this interpretation is that an ancestral river flowing along the modern upper Mississippi River valley made a sharp bend at Prairie du Chien, WI, and flowed eastward along the valley occupied by the modern lower Wisconsin River. This river, referred to here as the Wyalusing River, likely flowed northeastward into the Great Lakes (St. Lawrence) drainage until that path was blocked by ice advancing from the northwest. Subsequent stream piracy immediately south of the modern confluence of the Mississippi and Wisconsin Rivers rerouted these streams, converting them to the headwaters of the greater Mississippi drainage. The combined rerouting of these river systems into entirely different drainage basins necessitates significant fundamental

  3. Sensing land pollution.

    Science.gov (United States)

    Bowden, L. W.

    1971-01-01

    Land pollution is described in numerous ways by various societies. Pollutants of land are material by-products of human activity and range from environmentally ineffective to positively toxic. The pollution of land by man is centuries old and correlates directly with economy, technology and population. In order to remotely sense land pollution, standards or thresholds must be established. Examples of the potential for sensing land pollution and quality are presented. The technological capabilities for remotely sensed land quality is far advanced over the judgment on how to use the sensed data. Until authoritative and directive decisions on land pollution policy are made, sensing of pollutants will be a random, local and academic affair.

  4. Water Pollution, Causes and Cures.

    Science.gov (United States)

    Manufacturing Chemists Association, Washington, DC.

    This commentary on sources of water pollution and water pollution treatment systems is accompanied by graphic illustrations. Sources of pollution such as lake bottom vegetation, synthetic organic pollutants, heat pollution, radioactive substance pollution, and human and industrial waste products are discussed. Several types of water purification…

  5. EFFECTIVENESS OF AUTOGENIC DRAINAGE VERSUS POSTURAL DRAINAGE ON OXYGEN SATURATION IN PATIENTS WITH CHRONIC BRONCHITIS WITH 15 MINUTES POST THERAPY

    Directory of Open Access Journals (Sweden)

    V. Kiran

    2014-12-01

    Full Text Available Background: Patients with COPD will have more amount of secretions. To clear the secretions by using of different bronchial hygiene techniques like postural drainage and autogenic drainage technique, manual hyperventilation technique ,active cycle breathing technique .Hence in this study to compare the short-term effects of postural drainage with clapping (PD and autogenic drainage (AD on level of oxygen saturation in blood, and amount of sputum recovery. Methodology: The study was done on 60 patients with COPD. Dividing Patients into two group and patients were treated with PD or AD in separate Groups. The effectiveness of the treatment was measured up to 6 days. Pulse oximetry was monitored and sputum was collected immediately after treatment and 15 minutes following each treatment. Results: The results of the study shown that there was significant difference in the amount of sputum recovered with AD (14.0±3.5 g vs PD (24.4±3.0 g and significant differences in Oxygen saturation; during PD fell from 93.3±0.7% to 91.2±0.8% (p<0.01 and required 15 min following treatment to return to baseline. Oxygen saturation did not fall during AD and increased to gradually following complete treatment days (baseline, 93.3±0.8%; p<0.01. Conclusion: Hence this study concludes that Autogenic drainage is more effective in improving spo2 in COPD & does not cause a sudden fall in spo2 as occurs in Postural drainage immediately after therapy. And it can be better tolerated by patients with COPD while producing fewer benefits in sputum clearance. In concern to mean amount of secretion removal Postural is found to be more effective

  6. Atmospheric pollution. Introduction; Pollution atmospherique. Introduction

    Energy Technology Data Exchange (ETDEWEB)

    Elichegaray, Ch. [Agence de l' Environnement et de la Maitrise de l' Energie, 75 - Paris (France)

    2006-07-15

    This article is a general introduction to air pollution. It focusses on air quality problems at the local and regional scale: 1 - atmospheric environment and determining factors of its quality; 2 - French situation; 3 - local scale impacts: health hazards; 4 - regional scale impacts: risks for health and ecosystems (acid rains, photochemical pollution); 5 - management of the atmospheric environment (national scale, international scale: monitoring of air quality and role of the French agency of environment and energy mastery - Ademe). (J.S.)

  7. Throughfall patterns of a Subtropical Atlantic Forest in Brazil

    Science.gov (United States)

    Macedo Sá, João Henrique; Borges Chaffe, Pedro Luiz; Yuimi de Oliveira, Debora; Nery Giglio, Joana; Kobiyama, Masato

    2017-04-01

    The interception process is responsible for the spatial and temporal redistribution of the precipitation that reaches the ground. This process is important especially in forested areas since it influences recycling of moisture from the air and also the amount of water that effectively reaches the ground. The contact of the precipitation with the canopy influences on the water quality, increasing the concentration of various nutrients in the throughfall (Tf) and stemflow (Sf). Brazil, only about 8% of the original Atlantic Forest cover remains. That is an important biome and little is known about the characteristics of rainfall interception of this forest. The total interception loss in forested areas is usually formulated as the gross precipitation (P) minus the sum of the throughfall (Tf) and the stemflow (Sf). The stems characteristics influence on Sf, meanwhile, the value of Tf strongly depends on the canopy and leaf structures. Because of the complex structure of the canopy, these characteristics are usually expressed by the simpler Leaf Area Index (LAI) or the Canopy Cover Fraction (CCF). The Araponga river experimental catchment (ARA) with 5.3 ha is on the northern plateau of Santa Catarina State, southern Brazil. It is an area completely covered by secondary subtropical Atlantic Forest, the regional climate is the Köppen Cfb type, i.e., temperate climate without dry season and with warm summer (the mean temperature of the hottest month is always under 22°C). The objectives of the present study were (i) to evaluate the spatial and temporal variation of canopy cover; (ii) to influence of the interception process on the precipitation quality; and (iii) to explore the relation between canopy cover and throughfall. Inside the catchment, 9 Tf gauges were installed 40 cm above the soil surface in order to include the interception by shrub. 28 hand-made gauges were installed on a circular area of 3 m radius to analyze the spatial variability of throughfall. During

  8. Ozone, nitric acid, and ammonia air pollution is unhealthy for people and ecosystems in southern Sierra Nevada, California

    Science.gov (United States)

    R. Cisneros; A. Bytnerowicz; D. Schweizer; S. Zhong; S. Traina; D.H. Bennett

    2010-01-01

    Two-week average concentrations of ozone (O3), nitric acid vapor (HNO3) and ammonia (NH3) were measured with passive samplers during the 2002 summer season across the central Sierra Nevada Mountains, California, along the San Joaquin River drainage. Elevated concentrations of the pollutants were...

  9. Economic feasibility of surface flow constructed (SFCW) wetlands for reduction of water pollution from agricultural fields in Denmark

    DEFF Research Database (Denmark)

    Gachango, Florence Gathoni; Pedersen, Søren Marcus; Kjaergaard, Charlotte

    2014-01-01

    Constructed wetlands have been proposed as cost effective and more targeted technologies in the reduction of nitrogen and phosphorous water pollution in drainage losses from agricultural fields in Denmark. Using two pig farms and one dairy farm situated in a pumped lowland catchment as study cases...

  10. Occurrence of amphibians in northern California coastal dune drainages

    Science.gov (United States)

    Halstead, Brian J.; Kleeman, Patrick M.

    2017-01-01

    Many coastal dune ecosystems have been degraded by non-native dune vegetation, but these systems might still provide valuable habitat for some taxa, including amphibians. Because restoration of degraded dune systems is occurring and likely to continue, we examined the occurrence of amphibians in drainages associated with a coastal dune ecosystem degraded by invasive plants (European Beachgrass, Ammophila arenaria, and Iceplant, Carpobrotus edulis). We found that occupancy of 3 amphibian species (California Red-legged Frog, Rana draytonii; Sierran Treefrog, Hyliola sierra; and Rough-skinned Newt, Taricha granulosa) among 21 coastal-dune drainages was high, with most coastal-dune drainages occupied by all 3 species. Furthermore, reproduction of Sierran Treefrogs and California Red-legged Frogs was estimated to occur in approximately ½ and ⅓ of the drainages, respectively. The probability of occurrence of Rough-skinned Newts and pre-metamorphic life stages of both anurans decreased during the study, perhaps because of ongoing drought in California or precipitation-induced changes in phenology during the final year of the study. Maintaining structural cover and moist features during dune restoration will likely benefit native amphibian populations inhabiting coastal-dune ecosystems.

  11. A Theoretical Study of Subsurface Drainage Model Simulation of ...

    African Journals Online (AJOL)

    A three-dimensional variable-density groundwater flow model, the SEAWAT model, was used to assess the influence of subsurface drain spacing, evapotranspiration and irrigation water quality on salt concentration at the base of the root zone, leaching and drainage in salt affected irrigated land. The study was carried out ...

  12. Subsurface Agricultural Irrigation Drainage: The Need for Regulation

    Science.gov (United States)

    A. Dennis Lemly

    1993-01-01

    Subsurface drainage resulting from irrigated agriculture is a toxic threat to fish and wildlife resources throughout the western United States. Studies by the U.S. Department of the Interior show that migratory waterfowl have been poisoned by drainwater contaminants on at least six national wildlife refuges. Allowing this poisoning to continue is a violation of the...

  13. Long-Term Hydrologic Impacts of Controlled Drainage Using DRAINMOD

    Science.gov (United States)

    Saadat, S.; Bowling, L. C.; Frankenberger, J.

    2017-12-01

    Controlled drainage is a management strategy designed to mitigate water quality issues caused by subsurface drainage but it may increase surface ponding and runoff. To improve controlled drainage system management, a long-term and broader study is needed that goes beyond the experimental studies. Therefore, the goal of this study was to parametrize the DRAINMOD field-scale, hydrologic model for the Davis Purdue Agricultural Center located in Eastern Indiana and to predict the subsurface drain flow and surface runoff and ponding at this research site. The Green-Ampt equation was used to characterize the infiltration, and digital elevation models (DEMs) were used to estimate the maximum depressional storage as the surface ponding parameter inputs to DRAINMOD. Hydraulic conductivity was estimated using the Hooghoudt equation and the measured drain flow and water table depths. Other model inputs were either estimated or taken from the measurements. The DRAINMOD model was calibrated and validated by comparing model predictions of subsurface drainage and water table depths with field observations from 2012 to 2016. Simulations based on the DRAINMOD model can increase understanding of the environmental and hydrological effects over a broader temporal and spatial scale than is possible using field-scale data and this is useful for developing management recommendations for water resources at field and watershed scales.

  14. Economic analysis of solid waste management and drainage for ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Good solid waste management involves reducing volumes, improving collection, investing in drainage, replacing riverside and wetland dumping with engineered landfills, and identifying sustainable mechanisms to finance waste management. Research is needed to understand the potential impacts of climate change and ...

  15. Acid Mine Drainage Potential of the Coral Snake Waste Dump ...

    African Journals Online (AJOL)

    This paper assessed the Acid Mine Drainage (AMD) potential of the Coral Snake Waste Dump located close to the Enkansu and Kaw streams in Obuasi. Ten water and fifty rock samples were analysed for physico-chemical parameters. Acid Base Accounting (ABA) determinations using static methods were employed to ...

  16. Use of land located within Eselnita drainage basin

    Directory of Open Access Journals (Sweden)

    DANIELA VLAD

    2011-12-01

    Full Text Available Developed on the south-eastern side of Almãjului Mountains, Eşelniţa drainage basin neighbours upon the following basins: upon S – SV with Mala, upon SV - V with Mraconia, upon V - NV with Berzasca, upon NV - NNE with Nera and on the NNE – SE direction with Cerna. The basin has a surface of 77 km2 and present a 5th degree hydrographic network according to Horton-Strahler ranking system, tributary to Danube by means of Eşelniţa main collector. Among surfaces belonging to various categories of use of land located within Eselnita drainage basin, there may be noticed the high share of forest and secondary grazing lands, although the latter have a smaller surface in comparison to the first ones. Therefore, the types of use of land located within the drainage basin are distinguished by the high share of surfaces of forests to the detriment of predominant agricultural land proven by using of some quantitative indexes defining the character of the Eselnita drainage basin as belonging to forestry type. Also the impact of human activities and number of inhabitants do not have a very damaging influence on the land corresponding to the basin, therefore it has a naturality index indicating an ecological equilibrium closed to the natural one.

  17. South Carolina's best management practices for forestry for minor drainage

    Science.gov (United States)

    Tonya Smith; Herb Nicholson

    2016-01-01

    Minor drainage is normally used to facilitate regeneration and timber harvesting by temporarily removing surface water from inundated forestland. Specific ditch depth and spacing recommendations are not listed in our manual, as each site is individually evaluated.

  18. The Heimlich Valve for Pleural Cavity Drainage | Makanga | Annals ...

    African Journals Online (AJOL)

    Methods: A retrospective descriptive analysis of all chest drains connected to a Heimlich valve between January 2009 and December 2012. Data on indications, duration of drainage and frequency of complications was collected. Results: Fifty seven chest tubes connected to a Heimlich valve were inserted over the study ...

  19. Endoscopic Ultrasound-guided Drainage of Pancreatic Pseudocysts

    DEFF Research Database (Denmark)

    Ng, Pui Yung; Nytoft Rasmussen, Ditlev; Vilmann, Peter

    2013-01-01

    or by telephonic interview. RESULTS: A total of 61 procedures were performed. The symptoms that indicated drainage were abdominal pain (n = 43), vomiting (n = 7) and jaundice (n = 5). The procedure was technically successful in 57 of the 61 procedures (93%). The immediate complication rate was 5%. At a mean follow...

  20. The Effect of Camber Bed Drainage Landforms on Soil Nutrient ...

    African Journals Online (AJOL)

    The Vertisols of the Accra Plains of Ghana are water logged after significant rainfall due to the low-lying topography (0.1-1 %). Camber bed (Cb) drainage landforms have been developed at the Agricultural Research Centre, Kpong, for draining off excess water. Field experiments were conducted to verify if maize growth and ...