WorldWideScience

Sample records for drained soil

  1. Climate mitigation scenarios of drained peat soils

    Science.gov (United States)

    Kasimir Klemedtsson, Åsa; Coria, Jessica; He, Hongxing; Liu, Xiangping; Nordén, Anna

    2014-05-01

    The national inventory reports (NIR) submitted to the UNFCCC show Sweden - which as many other countries has wetlands where parts have been drained for agriculture and forestry purposes, - to annually emit 12 million tonnes carbon dioxide equivalents, which is more GHG'es than industrial energy use release in Sweden. Similar conditions can be found in other northern countries, having cool and wet conditions, naturally promoting peat accumulation, and where land use management over the last centuries have promoted draining activities. These drained peatland, though covering only 2% of the land area, have emissions corresponding to 20% of the total reported NIR emissions. This substantial emission contribution, however, is hidden within the Land Use Land Use Change and Forestry sector (LULUCF) where the forest Carbon uptake is even larger, which causes the peat soil emissions become invisible. The only drained soil emission accounted in the Swedish Kyoto reporting is the N2O emission from agricultural drained organic soils of the size 0.5 million tonnes CO2e yr-1. This lack of visibility has made incentives for land use change and management neither implemented nor suggested, however with large potential. Rewetting has the potential to decrease soil mineralization, why CO2 and N2O emissions are mitigated. However if the soil becomes very wet CH4 emission will increase together with hampered plant growth. By ecological modeling, using the CoupModel the climate change mitigation potential have been estimated for four different land use scenarios; 1, Drained peat soil with Spruce (business as usual scenario), 2, raised ground water level to 20 cm depth and Willow plantation, 3, raised ground water level to 10 cm depth and Reed Canary Grass, and 4, rewetting to an average water level in the soil surface with recolonizing wetland plants and mosses. We calculate the volume of biomass production per year, peat decomposition, N2O emission together with nitrate and DOC

  2. Water Table Recession in Subsurface Drained Soils

    OpenAIRE

    Moustafa, Mahmoud Mohamed; Yomota, Atsushi

    1999-01-01

    Theoretical drainage equations are intensively tested in many parts of humid and arid regions and are commonly used in drainage design. However, this is still a great concern in Japan as the drainage design is exclusively based on local experiences and empirical basis. There is a need therefore to evaluate the theoretical drainage equations under Japanese field conditions to recommend equations for design of subsurface drainage systems. This was the main motivation for this study. While drain...

  3. The effect of drains on the alkalinity of agricultural soils

    International Nuclear Information System (INIS)

    Iqbal, M.A.; Butt, T.; Anwar-ul-Haque; Haroon, M.; Haq, I.U.

    2009-01-01

    The purpose of the study was to observe the effect of industrial and domestic drains on the nearby agricultural areas which are either irrigated or not by the waste water but are close to drains. For this purpose 48 soil samples were collected from the selected areas of Faisalabad and were analyzed for alkali metals like Na/sup +/, K/sup +/, Li/sup +/ and some alkaline earth metals like Ba/sup 2+/> Mg/sup 3+/> Na/sup +/> K/sup +/> Li/sup +/ the levels of Ba/sup +2/ and K/sup +/ were found higher than permissible levels in almost all the soil samples. It was also concluded that the agricultural areas near the industrial drain which are either irrigated or not by the industrial waste water are found highly contaminated with mobile alkali metals (K, Na etc.) and higher values of percentage salinity. (author)

  4. Application of Prefabricated Vertical Drain in Soil Improvement

    Directory of Open Access Journals (Sweden)

    Tedjakusuma B.

    2012-01-01

    Full Text Available Although the use of Prefabricated Vertical Drain (PVD in soil improvement is not new, this paper is interesting since it gives the full spectrum from preliminary design stage; trial embankment and pilot test to final soil improvement. The final installation of the PVD was based on the soil investigation report and the results of instrumentation monitoring. Finally, using back analysis, vertical and horizontal coefficients of consolidation and compression index can be determined, which can be applied to predict a more accurate prediction of settlement.

  5. Characterization Plan for Soils Around Drain Line PLA-100115

    Energy Technology Data Exchange (ETDEWEB)

    D. Shanklin

    2006-05-24

    This Characterization Plan supports the Hazardous Waste Management Act/Resource Conservation and Recovery Act (HWMA/RCRA) closure of soils that may have been contaminated by releases from drain line PLA-100115, located within the Idaho Nuclear Technology and Engineering Center at the Idaho National Laboratory Site. The requirements to address the closure of soils contaminated by a potential release from this line in a characterization plan was identified in the "HWMA/RCRA Less Than 90-day Generator Closure Report for the VES-SFE-126."

  6. Centrifuge modelling of drained lateral pile - soil response

    DEFF Research Database (Denmark)

    Klinkvort, Rasmus Tofte

    of rigid piles. The tests have been performed in homogeneously dense dry or saturated Fontainebleau sand in order to mimic simplified drained offshore soil conditions. Approximately half of the tests have been carried out to investigate the centrifuge procedure in order to create a methodology of testing...... tests were used to investigate the pile - soil interaction to gain a better in-sight into the complex problem. A monotonic test series was carried out initially and then pile - soil interaction curves were deduced from these tests and compared with methodologies used today. The results indicate...... that the current methodologies can be improved and a modification to the methodology has been proposed. Secondly, a cyclic test series was carried out. The accumulation of displacement and the change in secant stiffness of the total response of these tests were evaluated. A simple mathematical model was proposed...

  7. Powerful Software to Simulate Soil Consolidation Problems with Prefabricated Vertical Drains

    OpenAIRE

    Gonzalo García-Ros; Iván Alhama; Manuel Cánovas

    2018-01-01

    The present work describes the program Simulation of Consolidation with Vertical Drains (SICOMED_2018), a tool for the solution of consolidation processes in heterogeneous soils, with totally or partially penetrating prefabricated vertical drains (PVD) and considering both the effects of the smear zone, generated when introducing the drain into the ground, and the limitation in the discharge capacity of the drain. In order to provide a completely free program, the code Next-Generation Simulat...

  8. An Equal-Strain Analytical Solution for the Radial Consolidation of Unsaturated Soils by Vertical Drains considering Drain Resistance

    Directory of Open Access Journals (Sweden)

    Feng Zhou

    2018-01-01

    Full Text Available Developing an analytical solution for the consolidation of unsaturated soils remains a challenging task due to the complexity of coupled governing equations for air and water phases. This paper presents an equal-strain model for the radial consolidation of unsaturated soils by vertical drains, and the effect of drain resistance is also considered. Simplified governing equations are established, and an analytical solution to calculate the excess pore-air and pore-water pressures is derived by using the methods of matrix analysis and eigenfunction expansion. The average degrees of consolidation for air and water phases and the ground surface settlement are also given. The solutions of the equal-strain model are verified by comparing the proposed free-strain model with the equal-strain model, and reasonably good agreement is obtained. Moreover, parametric studies regarding the drain resistance effect are graphically presented.

  9. Heterotrophic soil respiration in forestry-drained peatlands

    International Nuclear Information System (INIS)

    Minkkinen, K.; Shurpali, N. J.; Alm, J.; Penttilae, T.

    2007-01-01

    Heterotrophic soil respiration (CO 2 efflux from the decomposition of peat and root litter) in three forestry-drained peatlands with different site types and with a large climatic gradient from the hemi-boreal (central Estonia) to south (southern Finland) and north boreal (northern Finland) conditions was studied. Instantaneous fluxes varied between 0 and 1.3 g CO 2 -C m -2 h -1 , and annual fluxes between 248 and 515 g CO 2 -C m -2 a -1 . Variation in the annual fluxes among site types was studied only in the south-boreal site where we found a clear increase from nutrient-poor to nutrient-rich site types. More than half of the within-site variation was temporal and explained by soil surface (-5 cm) temperature (T5). The response of soil respiration to T5 varied between the sites; the most northerly site had the highest response to T5 and the most southerly the lowest. This trend further resulted in increased annual fluxes towards north. This unexpected result is hypothesised to be related to differences in site factors like substrate quality, nutrient status and hydrology but also to temperature acclimation, i.e., adaptation of decomposer populations to different climates. (orig.)

  10. Carbon balance of rewetted and drained peat soils used for biomass production: A mesocosm study

    DEFF Research Database (Denmark)

    Karki, Sandhya; Elsgaard, Lars; Kandel, Tanka

    2016-01-01

    of lower CO2 emissions without losing agricultural land. The present study quantified the carbon balance (CO2, CH4 and harvested biomass C) of rewetted and drained peat soils under intensively managed reed canary grass (RCG) cultivation. Mesocosms were maintained at five different ground water levels (GWL......), i.e., 0, 10, 20 cm below the soil surface, representing rewetted peat soils, and 30 and 40 cm below the soil surface, representing drained peat soils. Net ecosystem exchange (NEE) of CO2 and CH4 emissions were measured during the growing period of RCG (May to September) using transparent and opaque...... closed chamber methods. The average dry biomass yield was significantly lower from rewetted peat soils (12 Mg ha−1) than drained peat soils (15 Mg ha−1). Also, CO2 fluxes of gross primary production (GPP) and ecosystem respiration (ER) from rewetted peat soils were significantly lower than drained peat...

  11. Strip-drains for in situ clean up of contaminated fine-grained soils

    International Nuclear Information System (INIS)

    Bowders, J.J.; Gabr, M.A.

    1995-01-01

    Methods for in situ remediation of contaminated soils, such as bioremediation, vacuum/air stripping and soil flushing have been found to be less effective under fine-grained soil conditions. To enhance the performance of these techniques, it was proposed that strip-drains or wick drains also known as prefabricated vertical (PV) drains be used. The research objective was to determine the feasibility of using PV drains to enhance the soil flushing process. Bench top and intermediate-scale laboratory experiments were conducted. An overview of the work, results and future considerations were presented. Results indicated that the technology is feasible. A preliminary model for the technology to be used in any field situation was developed. The model is currently being tested with data from physical experiments on both intermediate and field tests. 5 figs

  12. Estimating drain flow from measured water table depth in layered soils under free and controlled drainage

    Science.gov (United States)

    Saadat, Samaneh; Bowling, Laura; Frankenberger, Jane; Kladivko, Eileen

    2018-01-01

    Long records of continuous drain flow are important for quantifying annual and seasonal changes in the subsurface drainage flow from drained agricultural land. Missing data due to equipment malfunction and other challenges have limited conclusions that can be made about annual flow and thus nutrient loads from field studies, including assessments of the effect of controlled drainage. Water table depth data may be available during gaps in flow data, providing a basis for filling missing drain flow data; therefore, the overall goal of this study was to examine the potential to estimate drain flow using water table observations. The objectives were to evaluate how the shape of the relationship between drain flow and water table height above drain varies depending on the soil hydraulic conductivity profile, to quantify how well the Hooghoudt equation represented the water table-drain flow relationship in five years of measured data at the Davis Purdue Agricultural Center (DPAC), and to determine the impact of controlled drainage on drain flow using the filled dataset. The shape of the drain flow-water table height relationship was found to depend on the selected hydraulic conductivity profile. Estimated drain flow using the Hooghoudt equation with measured water table height for both free draining and controlled periods compared well to observed flow with Nash-Sutcliffe Efficiency values above 0.7 and 0.8 for calibration and validation periods, respectively. Using this method, together with linear regression for the remaining gaps, a long-term drain flow record for a controlled drainage experiment at the DPAC was used to evaluate the impacts of controlled drainage on drain flow. In the controlled drainage sites, annual flow was 14-49% lower than free drainage.

  13. Modelling Technique for the Assessment of the Sub-Soil Drain for Groundwater Seepage Remediation

    Directory of Open Access Journals (Sweden)

    Tajul Baharuddin Mohamad Faizal

    2017-01-01

    Full Text Available Groundwater simulation technique was carried out for examining the performance of sub-soil drain at problematic site area. Subsoil drain was proposed as one of solution for groundwater seepage occurred at the slope face by reducing groundwater table at Taman Botani Park Kuala Lumpur. The simulation technique used Modular Three-Dimensional Finite Difference Groundwater Flow (MODFLOW software. In transient conditions, the results of simulation showed that heads increases surpass 1 to 2 m from the elevation level of the slope area that caused groundwater seepage on slope face. This study attempt to decrease the heads increase surpass by using different sub-soil drain size in simulation technique. The sub-soil drain capable to decline the heads ranges of 1 to 2 m.

  14. Interpretation of Cone Penetration Testing in Silty Soils Conducted under Partially Drained Conditions

    DEFF Research Database (Denmark)

    Holmsgaard, Rikke; Nielsen, Benjaminn Nordahl; Ibsen, Lars Bo

    2016-01-01

    The standard penetration rate used in cone penetration tests (CPTs) is 20 mm=s, regardless of soil type, which yields fully drained penetration in sand and fully undrained penetration in clay. However, for silty soils that represent an intermediate grain size composition and unique characteristic...

  15. Community structure and soil pH determine chemoautotrophic carbon dioxide fixation in drained paddy soils.

    Science.gov (United States)

    Long, Xi-En; Yao, Huaiying; Wang, Juan; Huang, Ying; Singh, Brajesh K; Zhu, Yong-Guan

    2015-06-16

    Previous studies suggested that microbial photosynthesis plays a potential role in paddy fields, but little is known about chemoautotrophic carbon fixers in drained paddy soils. We conducted a microcosm study using soil samples from five paddy fields to determine the environmental factors and quantify key functional microbial taxa involved in chemoautotrophic carbon fixation. We used stable isotope probing in combination with phospholipid fatty acid (PLFA) and molecular approaches. The amount of microbial (13)CO2 fixation was determined by quantification of (13)C-enriched fatty acid methyl esters and ranged from 21.28 to 72.48 ng of (13)C (g of dry soil)(-1), and the corresponding ratio (labeled PLFA-C:total PLFA-C) ranged from 0.06 to 0.49%. The amount of incorporationof (13)CO2 into PLFAs significantly increased with soil pH except at pH 7.8. PLFA and high-throughput sequencing results indicated a dominant role of Gram-negative bacteria or proteobacteria in (13)CO2 fixation. Correlation analysis indicated a significant association between microbial community structure and carbon fixation. We provide direct evidence of chemoautotrophic C fixation in soils with statistical evidence of microbial community structure regulation of inorganic carbon fixation in the paddy soil ecosystem.

  16. Flow and transport processes in a macroporous subsurface-drained glacial till soil

    DEFF Research Database (Denmark)

    Villholth, Karen G.; Jensen, Karsten Høgh

    1998-01-01

    disturbance and compaction of the soil surface. Hypothetically introducing fully surface-connected macropores into the calibrated model resulted in a 22% increase in the loss of solute to the drain, indicating the significance of the hydraulic conditions at the soil surface and the model specification thereof......The experimental results from a field-scale tracer experiment in a subsurface-drained glacial till soil were analyzed by the application of a single/dual porosity model (MACRO), optionally accounting for concurrent and interacting flow and transport in the bulk soil porosity as well...... concentration. The exchange was overpredicted and too rapid when the soil aggregate size (distance between macropores) obtained from an image analysis of soil cores was used in the model. On this basis, the model assumption of instant equilibration of the solute across the matrix porosity, disregarding small...

  17. Differences in microbial community structure and nitrogen cycling in natural and drained tropical peatland soils.

    Science.gov (United States)

    Espenberg, Mikk; Truu, Marika; Mander, Ülo; Kasak, Kuno; Nõlvak, Hiie; Ligi, Teele; Oopkaup, Kristjan; Maddison, Martin; Truu, Jaak

    2018-03-16

    Tropical peatlands, which play a crucial role in the maintenance of different ecosystem services, are increasingly drained for agriculture, forestry, peat extraction and human settlement purposes. The present study investigated the differences between natural and drained sites of a tropical peatland in the community structure of soil bacteria and archaea and their potential to perform nitrogen transformation processes. The results indicate significant dissimilarities in the structure of soil bacterial and archaeal communities as well as nirK, nirS, nosZ, nifH and archaeal amoA gene-possessing microbial communities. The reduced denitrification and N 2 -fixing potential was detected in the drained tropical peatland soil. In undisturbed peatland soil, the N 2 O emission was primarily related to nirS-type denitrifiers and dissimilatory nitrate reduction to ammonium, while the conversion of N 2 O to N 2 was controlled by microbes possessing nosZ clade I genes. The denitrifying microbial community of the drained site differed significantly from the natural site community. The main reducers of N 2 O were microbes harbouring nosZ clade II genes in the drained site. Additionally, the importance of DNRA process as one of the controlling mechanisms of N 2 O fluxes in the natural peatlands of the tropics revealed from the results of the study.

  18. Phosphorus Dynamics in Long-Term Flooded, Drained, and Reflooded Soils

    Directory of Open Access Journals (Sweden)

    Juan Tian

    2017-07-01

    Full Text Available In flooded areas, soils are often exposed to standing water and subsequent drainage, thus over fertilization can release excess phosphorus (P into surface water and groundwater. To investigate P release and transformation processes in flooded alkaline soils, wheat-growing soil and vegetable-growing soil were selected. We flooded-drained-reflooded two soils for 35 d, then drained the soils, and 10 d later reflooded the soils for 17 d. Dissolved reactive phosphorus (DRP, soil inorganic P fractions, Olsen P, pH, and Eh in floodwater and pore water were analyzed. The wheat-growing soil had significantly higher floodwater DRP concentrations than vegetable-growing soil, and floodwater DRP in both soils decreased with the number of flooding days. During the reflooding period, DRP in overlying floodwater from both soils was less than 0.87 mg/L, which was 3–25 times less than that during the flooding period. Regardless of flooding or reflooding, pore water DRP decreased with flooding days. The highest concentration of pore water DRP observed at a 5-cm depth. Under the effect of fertilizing and flooding, the risk of vertical P movement in 10–50 cm was enhanced. P diffusion occurred from the top to the bottom of the soils. After flooding, Al-P increased in both soils, and Fe-P, O-P, Ca2-P decreased, while Fe-P, Al-P, and O-P increased after reflooding, When Olsen P in the vegetable-growing soil exceeded 180.7 mg/kg and Olsen P in the wheat-growing soil exceeded 40.8 mg/kg, the concentration of DRP in pore water increased significantly. Our results showed that changes in floodwater and pore water DRP concentrations, soil inorganic P fractions, and Olsen P are significantly affected by fertilizing and flooding; therefore, careful fertilizer management should be employed on flooded soils to avoid excess P loss.

  19. Diminishing peat oxidation of agricultural peat soils by infiltration via submerged drains

    NARCIS (Netherlands)

    Akker, van den J.J.H.; Hendriks, R.F.A.

    2017-01-01

    Oxidation of peat soils used in dairy farming in the western peat area of The Netherlands causes subsidence rates up to 13 mm.y and emissions of CO2 to about 27 t.ha.y. In 2003 experiments started with subsurface irrigation by submerged drains to raise groundwater levels to reduce oxidation and so

  20. Sinking during earthquakes: Critical acceleration criteria control drained soil liquefaction

    Science.gov (United States)

    Clément, C.; Toussaint, R.; Stojanova, M.; Aharonov, E.

    2018-02-01

    This article focuses on liquefaction of saturated granular soils, triggered by earthquakes. Liquefaction is defined here as the transition from a rigid state, in which the granular soil layer supports structures placed on its surface, to a fluidlike state, in which structures placed initially on the surface sink to their isostatic depth within the granular layer. We suggest a simple theoretical model for soil liquefaction and show that buoyancy caused by the presence of water inside a granular medium has a dramatic influence on the stability of an intruder resting at the surface of the medium. We confirm this hypothesis by comparison with laboratory experiments and discrete-element numerical simulations. The external excitation representing ground motion during earthquakes is simulated via horizontal sinusoidal oscillations of controlled frequency and amplitude. In the experiments, we use particles only slightly denser than water, which as predicted theoretically increases the effect of liquefaction and allows clear depth-of-sinking measurements. In the simulations, a micromechanical model simulates grains using molecular dynamics with friction between neighbors. The effect of the fluid is captured by taking into account buoyancy effects on the grains when they are immersed. We show that the motion of an intruder inside a granular medium is mainly dependent on the peak acceleration of the ground motion and establish a phase diagram for the conditions under which liquefaction happens, depending on the soil bulk density, friction properties, presence of water, and peak acceleration of the imposed large-scale soil vibrations. We establish that in liquefaction conditions, most cases relax toward an equilibrium position following an exponential in time. We also show that the equilibrium position itself, for most liquefaction regimes, corresponds to the isostatic equilibrium of the intruder inside a medium of effective density. The characteristic time to relaxation is

  1. Preservation of labile organic matter in soils of drained thaw lakes in Northern Alaska

    Science.gov (United States)

    Mueller, Carsten W.; Rethemeyer, Janet; Kao-Kniffin, Jenny; Löppmann, Sebastian; Hinkel, Kenneth; Bockheim, James

    2014-05-01

    A large number of studies predict changing organic matter (OM) dynamics in arctic soils due to global warming. In contrast to rather slowly altering bulk soil properties, single soil organic matter (SOM) fractions can provide a more detailed picture of the dynamics of differently preserved SOM pools in climate sensitive arctic regions. By the study of the chemical composition of such distinctive SOM fractions using nuclear magnetic resonance spectroscopy (NMR) together with radiocarbon analyses it is possible to evaluate the stability of the major OM pools. Approximately 50-75% of Alaska's Arctic Coastal Plain is covered with thaw lakes and drained thaw lakes that follow a 5,000 yr cycle of development (between creation and final drainage), thus forming a natural soil chronosequence. The drained thaw lakes offer the possibility to study SOM dynamics affected by permafrost processes over millennial timescales. In April 2010 we sampled 16 soil cores (including the active and permanent layer) reaching from young drained lakes (0-50 years since drainage) to ancient drained lakes (3000-5500 years since drainage). Air dried soil samples from soil horizons of the active and permanent layer were subjected to density fractionation in order to differentiate particulate OM and mineral associated OM. The chemical composition of the SOM fractions was analyzed by 13C CPMAS NMR spectroscopy. For a soil core of a young and an ancient drained thaw lake basin we also analyzed the 14C content. For the studied soils we can show that up to over 25 kg OC per square meter are stored mostly as labile, easily degradable organic matter rich in carbohydrates. In contrast only 10 kg OC per square meter were sequestered as presumably more stable mineral associated OC dominated by aliphatic compounds. Comparable to soils of temperate regions, we found small POM (dating we could show the stabilization of younger more labile OM at greater depth in buried O horizons. Additionally the study of the

  2. A new design equation for drained stability of conical slopes in cohesive-frictional soils

    Directory of Open Access Journals (Sweden)

    Boonchai Ukritchon

    2018-04-01

    Full Text Available New plasticity solutions to the drained stability of conical slopes in homogeneous cohesive-frictional soils were investigated by axisymmetric finite element limit analysis. Three parameters were studied, i.e. excavated height ratios, slope inclination angles, and soil friction angles. The influences of these parameters on the stability factor and predicted failure mechanism of conical slopes were discussed. A new design equation developed from a nonlinear regression of the lower bound solution was proposed for drained stability analyses of a conical slope in practice. Numerical examples were given to demonstrate a practical application of the proposed equation to stability evaluations of conical slopes with both associated and non-associated flow rules. Keywords: Limit analysis, Slope stability, Conical slope, Unsupported excavation, Cohesive-frictional soils

  3. Dissolved organic nitrogen (DON) losses from nested artificially drained lowland catchments with contrasting soil types

    Science.gov (United States)

    Tiemeyer, Bärbel; Kahle, Petra; Lennartz, Bernd

    2010-05-01

    Artificial drainage is a common practice to improve moisture and aeration conditions of agricultural land. It shortens the residence time of water in the soil and may therefore contribute to the degradation of peatlands as well as to the still elevated level of diffuse pollution of surface water bodies, particularly if flow anomalies like preferential flow cause a further acceleration of water and solute fluxes. Especially in the case of nitrate, artificially drained sub-catchments are found to control the catchment-scale nitrate losses. However, it is frequently found that nitrate losses and nitrogen field balances do not match. At the same time, organic fertilizers are commonly applied and, especially in lowland catchments, organic soils have been drained for agricultural use. Thus, the question arises whether dissolved organic nitrogen (DON) forms an important component of the nitrogen losses from artificially drained catchments. However, in contrast to nitrate and even to dissolved organic carbon (DOC), this component is frequently overlooked, especially in nested catchment studies with different soil types and variable land use. Here, we will present data from a hierarchical water quantity and quality measurement programme in the federal state Mecklenburg-Vorpommern (North-Eastern Germany). The monitoring programme in the pleistocene lowland catchment comprises automatic sampling stations at a collector drain outlet (4.2 ha catchment), at a ditch draining arable land on mineral soils (179 ha), at a ditch mainly draining grassland on organic soils (85 ha) and at a brook with a small rural catchment (15.5 km²) of mixed land use and soil types. At all sampling stations, daily to weekly composite samples were taken, while the discharge and the meteorological data were recorded continuously. Water samples were analyzed for nitrate-nitrogen, ammonium-nitrogen and total nitrogen. We will compare two years: 2006/07 was a very wet year (P = 934 mm) with a high summer

  4. Powerful Software to Simulate Soil Consolidation Problems with Prefabricated Vertical Drains

    Directory of Open Access Journals (Sweden)

    Gonzalo García-Ros

    2018-02-01

    Full Text Available The present work describes the program Simulation of Consolidation with Vertical Drains (SICOMED_2018, a tool for the solution of consolidation processes in heterogeneous soils, with totally or partially penetrating prefabricated vertical drains (PVD and considering both the effects of the smear zone, generated when introducing the drain into the ground, and the limitation in the discharge capacity of the drain. In order to provide a completely free program, the code Next-Generation Simulation Program with Integrated Circuit Emphasis (Ngspice has been used as a numerical tool while the Matrix Laboratory (MATLAB code was used to program and create an interface with the user through interactive screens. In this way, SICOMED_2018 is presented as an easy-to-use and intuitive program, with a simple graphical interface that allows the user to enter all the soil properties and geometry of the problem without having to resort to a complex software package that requires programming. Illustrative applications describe both the versatility of the program and the reliability of its numerical solutions.

  5. No tillage and liming reduce greenhouse gas emissions from poorly drained agricultural soils in Mediterranean regions

    International Nuclear Information System (INIS)

    García-Marco, Sonia; Abalos, Diego; Espejo, Rafael; Vallejo, Antonio; Mariscal-Sancho, Ignacio

    2016-01-01

    No tillage (NT) has been associated to increased N_2O emission from poorly drained agricultural soils. This is the case for soils with a low permeable Bt horizon, which generates a perched water layer after water addition (via rainfall or irrigation) over a long period of time. Moreover, these soils often have problems of acidity and require liming application to sustain crop productivity; changes in soil pH have large implications for the production and consumption of soil greenhouse gas (GHG) emissions. Here, we assessed in a split-plot design the individual and interactive effects of tillage practices (conventional tillage (CT) vs. NT) and liming (Ca-amendment vs. not-amendment) on N_2O and CH_4 emissions from poorly drained acidic soils, over a field experiment with a rainfed triticale crop. Soil mineral N concentrations, pH, temperature, moisture, water soluble organic carbon, GHG fluxes and denitrification capacity were measured during the experiment. Tillage increased N_2O emissions by 68% compared to NT and generally led to higher CH_4 emissions; both effects were due to the higher soil moisture content under CT plots. Under CT, liming reduced N_2O emissions by 61% whereas no effect was observed under NT. Under both CT and NT, CH_4 oxidation was enhanced after liming application due to decreased Al"3"+ toxicity. Based on our results, NT should be promoted as a means to improve soil physical properties and concurrently reduce N_2O and CH_4 emissions. Raising the soil pH via liming has positive effects on crop yield; here we show that it may also serve to mitigate CH_4 emissions and, under CT, abate N_2O emissions. - Highlights: • The effect of tillage and liming on GHG was studied in poorly drained acidic soils. • NT reduced N_2O emissions, global warming potential and greenhouse gases intensity. • Liming reduced N_2O and CH_4 emissions under CT; no effect was observed under NT. • NT and liming provide an opportunity for N_2O and CH_4 mitigation.

  6. No tillage and liming reduce greenhouse gas emissions from poorly drained agricultural soils in Mediterranean regions

    Energy Technology Data Exchange (ETDEWEB)

    García-Marco, Sonia, E-mail: sonia.garcia@upm.es [Departamento de Química y Tecnología de los Alimentos, E.T.S.I. Agronómica, Alimentaria y de Biosistemas, Universidad Politécnica de Madrid, Ciudad Universitaria, 28040 Madrid (Spain); Abalos, Diego, E-mail: diego.abalosrodriguez@wur.nl [Departamento de Química y Tecnología de los Alimentos, E.T.S.I. Agronómica, Alimentaria y de Biosistemas, Universidad Politécnica de Madrid, Ciudad Universitaria, 28040 Madrid (Spain); Espejo, Rafael, E-mail: rafael.espejo@upm.es [Departamento de Producción Agraria, E.T.S.I. Agronómica, Alimentaria y de Biosistemas, Universidad Politécnica de Madrid, Ciudad Universitaria, 28040 Madrid (Spain); Vallejo, Antonio, E-mail: antonio.vallejo@upm.es [Departamento de Química y Tecnología de los Alimentos, E.T.S.I. Agronómica, Alimentaria y de Biosistemas, Universidad Politécnica de Madrid, Ciudad Universitaria, 28040 Madrid (Spain); Mariscal-Sancho, Ignacio, E-mail: i.mariscal@upm.es [Departamento de Producción Agraria, E.T.S.I. Agronómica, Alimentaria y de Biosistemas, Universidad Politécnica de Madrid, Ciudad Universitaria, 28040 Madrid (Spain)

    2016-10-01

    No tillage (NT) has been associated to increased N{sub 2}O emission from poorly drained agricultural soils. This is the case for soils with a low permeable Bt horizon, which generates a perched water layer after water addition (via rainfall or irrigation) over a long period of time. Moreover, these soils often have problems of acidity and require liming application to sustain crop productivity; changes in soil pH have large implications for the production and consumption of soil greenhouse gas (GHG) emissions. Here, we assessed in a split-plot design the individual and interactive effects of tillage practices (conventional tillage (CT) vs. NT) and liming (Ca-amendment vs. not-amendment) on N{sub 2}O and CH{sub 4} emissions from poorly drained acidic soils, over a field experiment with a rainfed triticale crop. Soil mineral N concentrations, pH, temperature, moisture, water soluble organic carbon, GHG fluxes and denitrification capacity were measured during the experiment. Tillage increased N{sub 2}O emissions by 68% compared to NT and generally led to higher CH{sub 4} emissions; both effects were due to the higher soil moisture content under CT plots. Under CT, liming reduced N{sub 2}O emissions by 61% whereas no effect was observed under NT. Under both CT and NT, CH{sub 4} oxidation was enhanced after liming application due to decreased Al{sup 3+} toxicity. Based on our results, NT should be promoted as a means to improve soil physical properties and concurrently reduce N{sub 2}O and CH{sub 4} emissions. Raising the soil pH via liming has positive effects on crop yield; here we show that it may also serve to mitigate CH{sub 4} emissions and, under CT, abate N{sub 2}O emissions. - Highlights: • The effect of tillage and liming on GHG was studied in poorly drained acidic soils. • NT reduced N{sub 2}O emissions, global warming potential and greenhouse gases intensity. • Liming reduced N{sub 2}O and CH{sub 4} emissions under CT; no effect was observed under NT

  7. A Worldwide Assessment of Greenhouse Gas Emissions from Drained Organic Soils

    Directory of Open Access Journals (Sweden)

    Francesco Nicola Tubiello

    2016-04-01

    Full Text Available Despite the importance of organic soils, including peatlands, in the global carbon cycle, detailed information on regional and global emissions is scarce. This is due to the difficulty to map, measure, and assess the complex dynamics of land, soil, and water interactions needed to assess the human-driven degradation of organic soils. We produced a new methodology for the comprehensive assessment of drained organic soils in agriculture and the estimation of the associated greenhouse gas emissions. Results indicated that over 25 million hectares of organic soils were drained worldwide for agriculture use, of which about 60% were in boreal and temperate cool areas, 34% in tropical areas, and 5% in warm temperate areas. Total emissions from the drainage were globally significant, totaling nearly one billion tonnes CO2eq annually. Of this, the CO2 component, about 780 million tonnes, represented more than one-fourth of total net CO2 emissions from agriculture, forestry, and land use. The bulk of these emissions came from a few tropical countries in Southeast Asia, and was linked to land clearing and drainage for crop cultivation. Geospatial data relative to this work were disseminated via the FAO geospatial server GeoNetwork, while the national aggregated statistics were disseminated via the FAOSTAT database.

  8. Interaction of the Bored Sand and Gravel Drain Pile with the Surrounding Compacted Loam Soil and Foundation Raft Taking into Account Rheological Properties of the Loam Soil and Non-Linear Properties of the Drain Pile

    Science.gov (United States)

    Ter-Martirosyan, Z. G.; Ter-Martirosyan, A. Z.; Anzhelo, G. O.; Buslov, A. S.

    2018-01-01

    The task of the interaction of the sand and gravel drain pile with the surrounding loam soil after its preliminary deep compaction and formation of the composite ground cylinder from the drain pile and surrounding compacted loam soil (cells) is considered in the article. It is seen that the subsidence and carrying capacity of such cell considerably depends on physical and mechanical properties of the compacted drain piles and surrounding loam soil as well as their diameter and intercellular distance. The strain-stress state of the cell is considered not taking into account its component elements, but taking into account linear and elastic-plastic properties of the drain pile and creep flow of the surrounding loam soil. It is stated that depending on these properties the distribution and redistribution of the load on a cell takes place from the foundation raft between the drain pile and surrounding soil. Based on the results of task solving the formulas and charts are given demonstrating the ratio of the load between the drain pile and surrounding loam soil in time.

  9. Stability performance and interface shear strength of geocomposite drain/soil systems

    Science.gov (United States)

    Othman, Maidiana; Frost, Matthew; Dixon, Neil

    2018-02-01

    Landfill covers are designed as impermeable caps on top of waste containment facilities after the completion of landfill operations. Geocomposite drain (GD) materials consist of a geonet or geospacer (as a drainage core) sandwiched between non-woven geotextiles that act as separators and filters. GD provides a drainage function as part of the cover system. The stability performance of landfill cover system is largely controlled by the interface shear strength mobilized between the elements of the cover. If a GD is used, the interface shear strength properties between the upper surface of the GD and the overlying soil may govern stability of the system. It is not uncommon for fine grained materials to be used as cover soils. In these cases, understanding soil softening issues at the soil interface with the non-woven geotextile is important. Such softening can be caused by capillary break behaviour and build-up of water pressures from the toe of the drain upwards into the cover soil. The interaction processes to allow water flow into a GD core through the soil-geotextile interface is very complex. This paper reports the main behaviour of in-situ interface shear strength of soil-GD using field measurements on the trial landfill cover at Bletchley, UK. The soil softening at the interface due to soaked behaviour show a reduction in interface shear strength and this aspect should be emphasized in design specifications and construction control. The results also help to increase confidence in the understanding of the implications for design of cover systems.

  10. The transformation of weak saturated soils using piles-drains for improving its mechanical properties

    Science.gov (United States)

    Ter-Martirosyan, Z. G.; Ter-Martirosyan, A. Z.; Sidorov, V. V.

    2018-04-01

    In practice of increased responsibility structures design there are often weak saturated clayey soils with low characteristics of deformability and strength take place on the construction site. In these cases, foundations using piles-drains of sandy or coarse material are recommended by norms, which is able to bear the load and to accelerate the consolidation process. The presented solutions include an analytical solution of the interaction problem between piles and slab raft foundation with the surrounding soil of the base with the possibility of extension of pile shaft. The closed-form solutions to determine the stresses in pile shaft and in the soil under the foundation slab are obtained. The article presents the results of large scale tests in the pilot area construction of major energy facilities in Russia.

  11. Soil settlement analysis in soft soil by using preloading system and prefabricated vertical draining runway of Kualanamu Airport

    Science.gov (United States)

    Roesyanto; Iskandar, R.; Silalahi, S. A.; Fadliansyah

    2018-02-01

    The method of soil improvement, using the combination of prefabricated vertical drain (PVD) and preloading, was used to accelerate the process of consolidation and the consolidation settlement in the runway of Kualanamu International Airport, which was constructed on the soft soil sediment like silty clay. In this research, the investigated area was the runway of Kualanamu International Airport zone I which had 11 meter-thickness of soft soil. Geotechnic instruments surveyed was settlement plate. Monitoring was done toward the behavior of landfill such as basic soil settlement. The result were compared with the analysis of finite element method of full scale in Mohr-Coulomb model by verifying the vertical drain of asymmetric unit cell and equivalent plane strain unit cell condition. The results of the research showed that there were an interesting behavior between the data in field observation and finite element of Mohr-Coulomb model. It was also found that the result of soil settlement of finite element method of Mohr-Coulomb model was closed to the result of settlement plate monitoring.

  12. Breakthrough of two pesticides into tile drain and shallow groundwater: comparison of tile drain reaction and soil profiles within a field scale irrigation experiment

    Science.gov (United States)

    Klaus, Julian; Zehe, Erwin; Elsner, Martin; Palm, Juliane; Schneider, Dorothee; Schröder, Boris; Steinbeiss, Sibylle; West, Stephanie

    2010-05-01

    Preferential flow in macropores is a key process which strongly affects infiltration and may cause rapid transport of pesticides into depths of 80 to 150 cm. At these depths they experience a much slower degradation, may leach into shallow groundwater or enter a tile-drain and are transported into surface water bodies. Therefore, preferential transport might be an environmental problem, if the topsoil is bypassed, which has been originally thought to act as a filter to protect the subsoil and shallow groundwater. To investigate the behaviour of two pesticides with different chemical characteristics and to compare their transport behaviour in soil and into the tile drain an irrigation experiment was performed on a 400 m² field site. The experimental plot is located in the Weiherbach valley, south-west Germany, which basic geology consists of Loess and Keuper layers, the soil at the test site is a gleyic Colluvisol. The distance of the irrigation site to the Weiherbach brook is approximately 12 m, the field is drained with a tile-drain in about 1.2 m depth and shows discharge over the entire year. Three hours before the irrigation started, the farmer applied a pesticide solution consisting of Isoproturon (80 g) and Flufenacet (20 g) (IPU and FLU) according to conventional agricultural practice on the field plot. The irrigation took place in three time blocks (80 min, 60 min, 80 min) with in total 33.6 mm of precipitation. During the first block 1600 g of Bromide were mixed in the irrigation water. The drainage outlet was instrumented with a pressure probe. About 50 water samples ware taken during the experimental day, and several samples more the days after the experiment. They were analysed for the pesticides, bromide and water isotopes. In the two days after the experiment three soil profiles were excavated and soil samples were taken on a 10x10 cm² scheme. One week after the experiment two additional profiles were excavated. The soil was analysed for IPU, FLU

  13. Spatial variation in herbicide leaching from a marine clay soil via subsurface drains

    Science.gov (United States)

    Ulén, Barbro M; Larsbo, Mats; Kreuger, Jenny K; Svanbäck, Annika

    2013-01-01

    Background Subsurface transport via tile drains can significantly contribute to pesticide contamination of surface waters. The spatial variation in subsurface leaching of normally applied herbicides was examined together with phosphorus losses in 24 experimental plots with water sampled flow-proportionally. The study site was a flat, tile-drained area with 60% marine clay in the topsoil in southeast Sweden. The objectives were to quantify the leaching of frequently used herbicides from a tile drained cracking clay soil and to evaluate the variation in leaching within the experimental area and relate this to topsoil management practices (tillage method and structure liming). Results In summer 2009, 0.14, 0.22 and 1.62%, respectively, of simultaneously applied amounts of MCPA, fluroxypyr and clopyralid were leached by heavy rain five days after spraying. In summer 2011, on average 0.70% of applied bentazone was leached by short bursts of intensive rain 12 days after application. Peak flow concentrations for 50% of the treated area for MCPA and 33% for bentazone exceeded the Swedish no-effect guideline values for aquatic ecosystems. Approximately 0.08% of the glyphosate applied was leached in dissolved form in the winters of 2008/2009 and 2010/2011. Based on measurements of glyphosate in particulate form, total glyphosate losses were twice as high (0.16%) in the second winter. The spatial inter-plot variation was large (72–115%) for all five herbicides studied, despite small variations (25%) in water discharge. Conclusions The study shows the importance of local scale soil transport properties for herbicide leaching in cracking clay soils. © 2013 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. PMID:23658148

  14. Heterotrophic soil respiration in drained peatlands: Abiotic drivers, and changes after clearfelling and afforestation

    Energy Technology Data Exchange (ETDEWEB)

    Maekiranta, P.

    2012-07-01

    Climate change is likely to affect the large carbon (C) stocks of northern peatlands. These C reservoirs may further be affected by human-induced forestry activities and changes in land use. Possible responses of peatland C storages to these changes have significant uncertainties mainly because of the difficulties in predicting peat decomposition rates in changing conditions. This study aims at revealing the effects of abiotic drivers, especially soil temperature and water table level (WL), on peat decomposition rate indicated by heterotrophic peat soil respiration (R{sub PEAT}) in drained forested peatlands. Furthermore it aims to describe the changes in R{sub PEAT} following clearfelling in forestry-drained peatlands and afforestation of former agricultural organic soil croplands. For this, R{sub PEAT} was estimated using chambers to measure CO{sub 2} efflux from trenched litter-free plots, at nine afforested organic soil cropland sites and one forestrydrained site with clearfelling treatment. This study revealed that within the studied sites soil temperature was the main driver of R{sub PEAT}. It was also apparent that the old peat storage in these sites was rather resistant to the short-term changes in WL conditions; i.e. fluctuations of WL caused only minor changes in R{sub PEAT}. The study also demonstrated that in low water level conditions there were mechanisms that could hinder R{sub PEAT}. Excessive WL drawdown (>61cm ) was observed to reduce R{sub PEAT} and furthermore, in low water level conditions the temperature sensitivity of R{sub PEAT} was reduced. These findings suggest that climate change and the associated increase in temperature would have the potential to substantially increase soil C release from drained peatlands. This C release may, however, be constrained, if warming is accompanied by changes in evapotranspiration, precipitation regimes, or the frequency of extreme events (e.g. droughts) that would severely affect WL and surface soil

  15. Migratory bird habitat in relation to tile drainage and poorly drained hydrologic soil groups

    Science.gov (United States)

    Kastner, Brandi; Christensen, Victoria G.; Williamson, Tanja N.; Sanocki, Chris A.

    2016-01-01

    The Prairie Pothole Region (PPR) is home to more than 50% of the migratory waterfowl in North America. Although the PPR provides an abundance of temporary and permanent wetlands for nesting and feeding, increases in commodity prices and agricultural drainage practices have led to a trend of wetland drainage. The Northern Shoveler is a migratory dabbling duck species that uses wetland habitats and cultivated croplands in the PPR. Richland County in North Dakota and Roberts County in South Dakota have an abundance of wetlands and croplands and were chosen as the study areas for this research to assess the wetland size and cultivated cropland in relation to hydrologic soil groups for the Northern Shoveler habitat. This study used geographic information system data to analyze Northern Shoveler habitats in association with Natural Resource Conservation Service soil data. Habitats, which are spatially associated with certain hydrologic soil groups, may be at risk of artificial drainage installations because of their proximity to cultivated croplands and soil lacking in natural drainage that may become wet or inundated. Findings indicate that most wetlands that are part of Northern Shoveler habitats were within or adjacent to cultivated croplands. The results also revealed soil hydrologic groups with high runoff potential and low water transmission rates account for most of the soil within the Northern Shoveler‘s wetland and cropland habitats. Habitats near agriculture with high runoff potential are likely to be drained and this has the potential of reducing Northern Shoveler habitat.

  16. Complete and Partial Photo-oxidation of Dissolved Organic Matter Draining Permafrost Soils.

    Science.gov (United States)

    Ward, Collin P; Cory, Rose M

    2016-04-05

    Photochemical degradation of dissolved organic matter (DOM) to carbon dioxide (CO2) and partially oxidized compounds is an important component of the carbon cycle in the Arctic. Thawing permafrost soils will change the chemical composition of DOM exported to arctic surface waters, but the molecular controls on DOM photodegradation remain poorly understood, making it difficult to predict how inputs of thawing permafrost DOM may alter its photodegradation. To address this knowledge gap, we quantified the susceptibility of DOM draining the shallow organic mat and the deeper permafrost layer of arctic soils to complete and partial photo-oxidation and investigated changes in the chemical composition of each DOM source following sunlight exposure. Permafrost and organic mat DOM had similar lability to photomineralization despite substantial differences in initial chemical composition. Concurrent losses of carboxyl moieties and shifts in chemical composition during photodegradation indicated that photodecarboxylation could account for 40-90% of DOM photomineralized to CO2. Permafrost DOM had a higher susceptibility to partial photo-oxidation compared to organic mat DOM, potentially due to a lower abundance of phenolic moieties with antioxidant properties. These results suggest that photodegradation will likely continue to be an important control on DOM fate in arctic freshwaters as the climate warms and permafrost soils thaw.

  17. Phosphorus and greenhouse gas dynamics in a drained calcareous wetland soil in Minnesota.

    Science.gov (United States)

    Berryman, Erin M; Venterea, Rodney T; Baker, John M; Bloom, Paul R; Elf, Brandy

    2009-01-01

    Restoration of wetland hydrology can produce ecological benefits but may have unintended consequences. We examined effects of altered water level on release of dissolved reactive phosphorus (DRP) and greenhouse gases (GHG) in soil cores from a marsh being evaluated for restoration. We also measured field concentrations of DRP and other constituents in wetland porewater. Intact cores from a sampling location with higher Fe and lower calcium carbonate (CaCO(3)) contents released more DRP than another location, and displayed higher DRP under completely saturated compared to partly drained conditions. Porewater samples collected from the high-Fe location also contained higher DRP levels. Chemical data suggest that redox-driven reactions largely controlled DRP levels at the high-Fe site, while CaCO(3) adsorption was more important at the low-Fe site. Over the long term, water table elevation may attenuate P draining from the wetland due to decreased mineralization. However, such measures may increase P release in the short term. Raising the water level in soil cores resulted in decreased nitrous oxide (N(2)O) emissions, increased methane (CH(4)) emissions, and an overall increase in total global warming potential (GWP). The proportion of total GWP contributed by N(2)O decreased from 14% to < or = 1% as water level was raised, while the proportion contributed by CH(4) increased from 10 to 20% to 60 to 80%. Restoration of hydrology in the Rice Lake wetland has the potential to affect both local water quality and global air quality. These combined effects complicate the cost-to-benefit analysis of such wetland restoration efforts.

  18. Nitrogen mineralization in forestry-drained peatland soils in the Stołowe Mountains National Park (Central Sudetes Mts

    Directory of Open Access Journals (Sweden)

    Glina Bartłomiej

    2016-06-01

    Full Text Available The aim of this work was to determine the intensity of nitrogen mineralization in forestry drained ombrotrophic peatland soils in the Stołowe Mountains National Park, SW Poland. Additionally discussion about the shallow organic soils classification according to Polish Soil Classification (2011 is presented. For the study three research transects were established on forestry drained ombrotrophic peatlands in the Stołowe Mountains. Each of the transect consisted of four (site A and B or five (site C sampling plots. Sampling was conducted in the year 2012. The soil samples for the basic soil properties analysis were sampled in April, whereas undisturbed soil samples were collected in stainless steel rings (100 cm3 every 10 cm in April (spring, July (summer and October (autumn to show the seasonal dynamics of nitrogen mineralization. Statistical analysis showed that the content of N-NH4 was mainly determined by actual soil moisture and precipitation rate, whereas the content of N-NO3 was positively correlated with air temperature. Among investigated peatlands the highest concentrations of mineral nitrogen forms was observed in the Długie Mokradło bog, situated on the Skalniak Plateau-summit. Additionally, the results obtained showed that implementation of new subtype: shallow fibric peat soils (in Polish: gleby torfowe fibrowe płytkie within the type of peat soils (in polish: gleby torfowe should be considered during developing of the next update of Polish Soil Classification.

  19. Photochemical alteration of organic carbon draining permafrost soils shifts microbial metabolic pathways and stimulates respiration.

    Science.gov (United States)

    Ward, Collin P; Nalven, Sarah G; Crump, Byron C; Kling, George W; Cory, Rose M

    2017-10-03

    In sunlit waters, photochemical alteration of dissolved organic carbon (DOC) impacts the microbial respiration of DOC to CO 2 . This coupled photochemical and biological degradation of DOC is especially critical for carbon budgets in the Arctic, where thawing permafrost soils increase opportunities for DOC oxidation to CO 2 in surface waters, thereby reinforcing global warming. Here we show how and why sunlight exposure impacts microbial respiration of DOC draining permafrost soils. Sunlight significantly increases or decreases microbial respiration of DOC depending on whether photo-alteration produces or removes molecules that native microbial communities used prior to light exposure. Using high-resolution chemical and microbial approaches, we show that rates of DOC processing by microbes are likely governed by a combination of the abundance and lability of DOC exported from land to water and produced by photochemical processes, and the capacity and timescale that microbial communities have to adapt to metabolize photo-altered DOC.The role of dissolved organic carbon (DOC) photo-alteration in the microbial respiration of DOC to CO 2 is unclear. Here, the authors show that the impact of this mechanism depends on whether photo-alteration of DOC produces or removes molecules used by native microbial communities prior to light exposure.

  20. Three-dimensional modelling of an embankment built on a soft soil improved with prefabricated vertical drains

    OpenAIRE

    Venda Oliveira, P.J.; Cruz, R.F.P.M.L.; Lemos, L.J.L.; Almeida e Sousa, J.N.V.

    2015-01-01

    This work compares the field measurements of a non-symmetric embankment built on a Portuguese soft soil improved with prefabricated vertical drains (PVDs), with the numerical predictions of a 3D modelling where the PVDs are simulated according to the field flow conditions. The change in the permeability with the void ratio and the effect of the smear zone are also included in the numerical analysis. The numerical predictions are compared with the field data in terms of settlement, horizontal ...

  1. Methane and CO2 fluxes from peat soil, palm stems and field drains in two oil palm plantations in Sarawak, Borneo, on different tropical peat soil types.

    Science.gov (United States)

    Manning, Frances; Lip Khoon, Kho; Hill, Tim; Arn Teh, Yit

    2017-04-01

    Oil palm plantations have been expanding rapidly on tropical peat soils in the last 20 years, with 50 % of SE Asian peatlands now managed as industrial or small-holder plantations, up from 11% in 1990. Tropical peat soils are an important carbon (C) store, containing an estimated 17 % of total peatland C. There are large uncertainties as to the soil C dynamics in oil palm plantations on peat due to a shortage of available data. It is therefore essential to understand the soil C cycle in order to promote effective management strategies that optimise yields, whilst maintaining the high C storage capacity of the soil. Here we present CO2 and CH4 fluxes from two oil palm plantations in Sarawak, Malaysia on peat soils. Data were collected from different surface microforms within each plantation that experienced different surface management practices. These included the area next to the palm, in bare soil harvest paths, beneath frond piles, underneath cover crops, from the surface of drains, and from palm stems. Data were collected continuously over one year and analysed with different environmental variables, including soil temperature, WTD, O2, soil moisture and weather data in order to best determine the constraints on the dataset. Total soil respiration (Rtot) varied between 0.09 and 1.59 g C m-2 hr-1. The largest fluxes (0.59 - 1.59 g C m-2 hr-1) were measured next to the palms. Larger CO2 fluxes were observed beneath the cover crops than in the bare soil. This trend was attributed to priming effects from the input of fresh plant litter and exudates. Peat soil type was shown to have significantly different fluxes. The different plantations also had different environmental drivers best explaining the variation in Rtot - with soil moisture being the most significant variable on Sabaju series soil and soil temperature being the most significant environmental variable in the plantation with the Teraja series soil. Rtot was shown to reduce significantly with increasing

  2. DRAINMOD-FOREST: Integrated Modeling of Hydrology, Soil Carbon and Nitrogen Dynamics, and Plant Growth for Drained Forests.

    Science.gov (United States)

    Tian, Shiying; Youssef, Mohamed A; Skaggs, R Wayne; Amatya, Devendra M; Chescheir, G M

    2012-01-01

    We present a hybrid and stand-level forest ecosystem model, DRAINMOD-FOREST, for simulating the hydrology, carbon (C) and nitrogen (N) dynamics, and tree growth for drained forest lands under common silvicultural practices. The model was developed by linking DRAINMOD, the hydrological model, and DRAINMOD-N II, the soil C and N dynamics model, to a forest growth model, which was adapted mainly from the 3-PG model. The forest growth model estimates net primary production, C allocation, and litterfall using physiology-based methods regulated by air temperature, water deficit, stand age, and soil N conditions. The performance of the newly developed DRAINMOD-FOREST model was evaluated using a long-term (21-yr) data set collected from an artificially drained loblolly pine ( L.) plantation in eastern North Carolina, USA. Results indicated that the DRAINMOD-FOREST accurately predicted annual, monthly, and daily drainage, as indicated by Nash-Sutcliffe coefficients of 0.93, 0.87, and 0.75, respectively. The model also predicted annual net primary productivity and dynamics of leaf area index reasonably well. Predicted temporal changes in the organic matter pool on the forest floor and in forest soil were reasonable compared to published literature. Both predicted annual and monthly nitrate export were in good agreement with field measurements, as indicated by Nash-Sutcliffe coefficients above 0.89 and 0.79 for annual and monthly predictions, respectively. This application of DRAINMOD-FOREST demonstrated its capability for predicting hydrology and C and N dynamics in drained forests under limited silvicultural practices. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  3. Triclosan affects the microbial community in simulated sewage-drain-field soil and slows down xenobiotic degradation

    Energy Technology Data Exchange (ETDEWEB)

    Svenningsen, Hanne [Department of Geochemistry, Geological Survey of Denmark and Greenland (GEUS), Oster Voldgade 10, DK-1350 Copenhagen K (Denmark); Department of Biology, University of Copenhagen, Solvgade 83H, DK-1307 Copenhagen K (Denmark); Henriksen, Trine [Department of Geochemistry, Geological Survey of Denmark and Greenland (GEUS), Oster Voldgade 10, DK-1350 Copenhagen K (Denmark); Prieme, Anders [Department of Biology, University of Copenhagen, Solvgade 83H, DK-1307 Copenhagen K (Denmark); Johnsen, Anders R., E-mail: arj@geus.dk [Department of Geochemistry, Geological Survey of Denmark and Greenland (GEUS), Oster Voldgade 10, DK-1350 Copenhagen K (Denmark)

    2011-06-15

    Effects of the common antibacterial agent triclosan on microbial communities and degradation of domestic xenobiotics were studied in simulated sewage-drain-field soil. Cultivable microbial populations decreased 22-fold in the presence of 4 mg kg{sup -1} of triclosan, and triclosan-resistant Pseudomonas strains were strongly enriched. Exposure to triclosan also changed the general metabolic profile (Ecoplate substrate profiling) and the general profile (T-RFLP) of the microbial community. Triclosan degradation was slow at all concentrations tested (0.33-81 mg kg{sup -1}) during 50-days of incubation. Mineralization experiments ({sup 14}C-tracers) and chemical analyses (LC-MS/MS) showed that the persistence of a linear alkylbenzene sulfonate (LAS) and a common analgesic (ibuprofen) increased with increasing triclosan concentrations (0.16-100 mg kg{sup -1}). The largest effect was seen for LAS mineralization which was severely reduced by 0.16 mg kg{sup -1} of triclosan. Our findings indicate that environmentally realistic concentrations of triclosan may affect the efficiency of biodegradation in percolation systems. - Highlights: > Triclosan may enter the soil environment through sewage. > Triclosan impacts the microbial community in sewage-drain-field soil. > Triclosan-resistant pseudomonads are strongly enriched. > Degradation of co-occurring LAS and ibuprofen is reduced. - Environmentally realistic triclosan concentrations in percolation systems may reduce the biodegradation of other xenobiotics and select for triclosan-resistant bacteria.

  4. Triclosan affects the microbial community in simulated sewage-drain-field soil and slows down xenobiotic degradation

    International Nuclear Information System (INIS)

    Svenningsen, Hanne; Henriksen, Trine; Prieme, Anders; Johnsen, Anders R.

    2011-01-01

    Effects of the common antibacterial agent triclosan on microbial communities and degradation of domestic xenobiotics were studied in simulated sewage-drain-field soil. Cultivable microbial populations decreased 22-fold in the presence of 4 mg kg -1 of triclosan, and triclosan-resistant Pseudomonas strains were strongly enriched. Exposure to triclosan also changed the general metabolic profile (Ecoplate substrate profiling) and the general profile (T-RFLP) of the microbial community. Triclosan degradation was slow at all concentrations tested (0.33-81 mg kg -1 ) during 50-days of incubation. Mineralization experiments ( 14 C-tracers) and chemical analyses (LC-MS/MS) showed that the persistence of a linear alkylbenzene sulfonate (LAS) and a common analgesic (ibuprofen) increased with increasing triclosan concentrations (0.16-100 mg kg -1 ). The largest effect was seen for LAS mineralization which was severely reduced by 0.16 mg kg -1 of triclosan. Our findings indicate that environmentally realistic concentrations of triclosan may affect the efficiency of biodegradation in percolation systems. - Highlights: → Triclosan may enter the soil environment through sewage. → Triclosan impacts the microbial community in sewage-drain-field soil. → Triclosan-resistant pseudomonads are strongly enriched. → Degradation of co-occurring LAS and ibuprofen is reduced. - Environmentally realistic triclosan concentrations in percolation systems may reduce the biodegradation of other xenobiotics and select for triclosan-resistant bacteria.

  5. Development and testing of watershed-scale models for poorly drained soils

    Science.gov (United States)

    Glenn P. Fernandez; George M. Chescheir; R. Wayne Skaggs; Devendra M. Amatya

    2005-01-01

    Watershed-scale hydrology and water quality models were used to evaluate the crrmulative impacts of land use and management practices on dowrzstream hydrology and nitrogen loading of poorly drained watersheds. Field-scale hydrology and nutrient dyyrutmics are predicted by DRAINMOD in both models. In the first model (DRAINMOD-DUFLOW), field-scale predictions are coupled...

  6. Laccase from a non-melanogenic, alkalotolerant gamma-proteobacterium JB isolated from industrial wastewater drained soil.

    Science.gov (United States)

    Bains, Jasleen; Capalash, Neena; Sharma, Prince

    2003-07-01

    A gram-negative, alkalotolerant bacterium, isolated from the soil continually drained with industrial wastewater and identified as gamma-proteobacterium by partial 16S rRNA sequence analysis, produced a polyphenol oxidase, which showed laccase but not tyrosinase activity. The organism grew well from pH 6 to 10 and produced laccase maximally at pH 10. The enzyme was stable from pH 3 to 10.6 for at least 24 h and was optimally active at 55 degrees C and pH 6.5 in a 5 min assay.

  7. Peat origin and land use effects on microbial activity, respiration dynamics and exo-enzyme activities in drained peat soils in the Netherlands

    NARCIS (Netherlands)

    Brouns, Karlijn; Keuskamp, Joost; Potkamp, Gerrit; Verhoeven, J.T.A.; Hefting, Mariet M.

    2016-01-01

    This study assessed the risk of decomposition-driven soil subsidence in drained peat soils in the Netherlands, contrasting in peat origin and current land use. In a full factorial design, fen peat and bog peat were sampled from sites in use for nature conservation and for dairy farming, which

  8. Microbial activity and community structure in two drained fen soils in the Ljubljana Marsh

    NARCIS (Netherlands)

    Kraigher, Barbara; Stres, Blaz; Hacin, Janez; Ausec, Luka; Mahne, Ivan; van Elsas, Jan D.; Mandic-Mulec, Ines

    Fen peatlands are specific wetland ecosystems containing high soil organic carbon (SOC). There is a general lack of knowledge about the microbial communities that abound in these systems. We examined the microbial activity and community structure in two fen soils differing in SOC content sampled

  9. Flow and transport processes in a macroporous subsurface-drained glacial till soil

    DEFF Research Database (Denmark)

    Villholth, Karen Grothe; Jensen, Karsten Høgh; Fredericia, Johnny

    1998-01-01

    of macropore structure and hydraulic efficiency, using image analysis and tension infiltration, and of soil water content, level of groundwater table, and chloride content of soil water within the soil profile yielded insights into small-scale processes and their associated variability. Macropore how...... into the soil profile. Dye infiltration experiments in the field as well as in the laboratory supported the recognition of the dominant contribution of macropores to the infiltration and transport process. The soil matrix significantly influenced the tracer distribution by acting as a source or sink...... for continuous solute exchange with the macropores. An average field-determined active macroporosity constituted 0.2% of the total porosity, or approximately 10% of the total macroporosity. (C) 1998 Elsevier Science B.V. All rights reserved....

  10. Transport of water, bromide ion, nutrients and the pesticides bentazone and imidacloprid in a cracking, tile drained clay soil at Andelst, the Netherlands

    NARCIS (Netherlands)

    Smelt, J.H.; Hendriks, R.F.A.; Pas, van der L.J.T.; Matser, A.M.; Toorn, van den A.; Oostindie, K.; Dijk-Hooijer, van O.M.; Boesten, J.J.T.I.; Scorza Júnior, R.P.

    2003-01-01

    The aim of this study was to perform a field experiment to collect a high quality data set suitable for validating and improving pesticide leaching models and nutrient leaching models for drained and cracking clay soils. The transport of water, bromide, nutrients and the pesticides bentazone and

  11. Corn nitrogen management influences nitrous oxide emissions in drained and undrained soils

    Science.gov (United States)

    Tile-drainage and nitrogen (N) fertilization are important for corn (Zea mays L.) production. To date, no studies have evaluated nitrous oxide (N2O) emissions of single vs. split-N fertilizer application under different soil drainage conditions. The objective of this study was to quantify season-lon...

  12. Loss of the soil carbon storage function of drained forested peatlands

    Directory of Open Access Journals (Sweden)

    C. Wüst-Galley

    2016-04-01

    Full Text Available Peatlands form a large but unstable C store. Drainage of peatlands converts them into C sources, which is undesirable if increases in atmospheric CO2 levels are to be minimised. Therefore, quantification of C stocks and an understanding of which ecosystems or management regimes are capturing or emitting C is needed. Such information is scarce for temperate European forests. We studied the soil properties of sixteen peatlands in Switzerland, representing three forest types, to test whether peatlands that are more strongly affected by drainage (according to vegetation have lost their function as C sinks or stores. Bulk density and ash enrichment, as well as H/C, O/C and C/N quotients, indicated that the soils of the two forest types that appeared to be more strongly affected by drainage were more degraded and had lost their functions as C stores. Long-term net rates of C loss estimated using the ash residue method were similar across all three forest types, for sites where this could be estimated.

  13. The effect of stocking rate on soil solution nitrate concentrations beneath a free-draining dairy production system in Ireland.

    Science.gov (United States)

    McCarthy, J; Delaby, L; Hennessy, D; McCarthy, B; Ryan, W; Pierce, K M; Brennan, A; Horan, B

    2015-06-01

    Economically viable and productive farming systems are required to meet the growing worldwide need for agricultural produce while at the same time reducing environmental impact. Within grazing systems of animal production, increasing concern exists as to the effect of intensive farming on potential N losses to ground and surface waters, which demands an appraisal of N flows within complete grass-based dairy farming systems. A 3-yr (2011 to 2013) whole-farm system study was conducted on a free-draining soil type that is highly susceptible to N loss under temperate maritime conditions. Soil solution concentrations of N from 3 spring-calving, grass-based systems designed to represent 3 alternative whole-farm stocking rate (SR) treatments in a post-milk quota situation in the European Union were compared: low (2.51 cows/ha), medium (2.92 cows/ha), and high SR (3.28 cows/ha). Each SR had its own farmlet containing 18 paddocks and 23 cows. Nitrogen loss from each treatment was measured using ceramic cups installed to a depth of 1m to sample the soil water. The annual and monthly average nitrate, nitrite, ammonia, and total N concentrations in soil solution collected were analyzed for each year using a repeated measures analysis. Subsequently, and based on the biological data collated from each farm system treatment within each year, the efficiency of N use was evaluated using an N balance model. Based on similar N inputs, increasing SR resulted in increased grazing efficiency and milk production per hectare. Stocking rate had no significant effect on soil solution concentrations of nitrate, nitrite, ammonia, or total N (26.0, 0.2, 2.4, and 32.3 mg/L, respectively). An N balance model evaluation of each treatment incorporating input and output data indicated that the increased grass utilization and milk production per hectare at higher SR resulted in a reduction in N surplus and increased N use efficiency. The results highlight the possibility for the sustainable

  14. Sap flow characteristics of neotropical mangroves in flooded and drained soils

    Science.gov (United States)

    Krauss, Ken W.; Young, P. Joy; Chambers, Jim L.; Doyle, Thomas W.; Twilley, Robert R.

    2007-01-01

    Effects of flooding on water transport in mangroves have previously been investigated in a few studies, most of which were conducted on seedlings in controlled settings. In this study, we used heat-dissipation sap probes to determine if sap flow (Js) attenuates with radial depth into the xylem of mature trees of three south Florida mangrove species growing in Rookery Bay. This was accomplished by inserting sap probes at multiple depths and monitoring diurnal flow. For most species and diameter size class combinations tested, Js decreased dramatically beyond a radial depth of 2 or 4 cm, with little sap flow beyond a depth of 6 cm. Mean Js was reduced on average by 20% in Avicennia germinans (L.) Stearn, Laguncularia racemosa (L.) Gaertn. f. and Rhizophora mangle L. trees when soils were flooded. Species differences were highly significant, with L. racemosahaving the greatest midday Js of about 26g H2O H2O m−2s−1 at a radial depth of 2 cm compared with a mean for the other two species of about 15 g H2O m−2s−1. Sap flow at a depth of 2 cm in mangroves was commensurate with rates reported for other forested wetland tree species. We conclude that: (1) early spring flooding of basin mangrove forests causes reductions in sap flow in mature mangrove trees; (2) the sharp attenuations in Js along the radial profile have implications for understanding whole-tree water use strategies by mangrove forests; and (3) regardless of flood state, individual mangrove tree water use follows leaf-level mechanisms in being conservative.

  15. Effectiveness of submerged drains in reducing subsidence of peat soils in agricultural use, and their effects on water management and nutrient loading of surface water: modelling of a case study in the western peat soil area of The Netherlands

    Science.gov (United States)

    Hendriks, Rob F. A.; van den Akker, Jan J. A.

    2017-04-01

    Effectiveness of submerged drains in reducing subsidence of peat soils in agricultural use, and their effects on water management and nutrient loading of surface water: modelling of a case study in the western peat soil area of The Netherlands In the Netherlands, about 8% of the area is covered by peat soils. Most of these soils are in use for dairy farming and, consequently, are drained. Drainage causes decomposition of peat by oxidation and accordingly leads to surface subsidence and greenhouse gas emission. Submerged drains that enhance submerged infiltration of water from ditches during the dry and warm summer half year were, and are still, studied in The Netherlands as a promising tool for reducing peat decomposition by raising groundwater levels. For this purpose, several pilot field studies in the Western part of the Dutch peat area were conducted. Besides the effectiveness of submerged drains in reducing peat decomposition and subsidence by raising groundwater tables, some other relevant or expected effects of these drains were studied. Most important of these are water management and loading of surface water with nutrients nitrogen, phosphorus and sulphate. Because most of these parameters are not easy to assess and all of them are strongly depending on the meteorological conditions during the field studies some of these studies were modelled. The SWAP model was used for evaluating the hydrological results on groundwater table and water discharge and recharge. Effects of submerged drains were assessed by comparing the results of fields with and without drains. An empirical relation between deepest groundwater table and subsidence was used to convert effects on groundwater table to effects on subsidence. With the SWAP-ANIMO model nutrient loading of surface water was modelled on the basis of field results on nutrient concentrations . Calibrated models were used to assess effects in the present situation, as thirty-year averages, under extreme weather

  16. Evolution of soil and vegetation cover on the bottom of drained thermokarst lake (a case study in the European Northeast of Russia)

    Science.gov (United States)

    Kaverin, Dmitry; Pastukhov, Alexander

    2015-04-01

    The evolution of soils and landscapes has been studied in a lake bed of former thermokarst lake, which was totally drained in 1979. Melioration of thermokarst lakes was conducted experimentally and locally under Soviet economics program during 1970-s. The aim of the program was to increase in biomass productivity of virgin tundra permafrost-thermokarst sites under agricultural activities. The former thermokarst lake "Opytnoe" located in the Bolshezemelskaya Tundra, Russian European Northeast. The lake bed is covered by peat-mineral sediments, which serves as soil-forming sediments favoring subsequent permafrost aggradation and cryogenic processes as well. Initially, after drainage, swampy meadows had been developed almost all over the lake bed. Further on, succession of landscape went diversely, typical and uncommon tundra landscapes formed. When activated, cryogenic processes favored the formation of peat mounds under dwarf shrub - lichen vegetation (7% of the area). Frost cracks and peat circles affected flat mounds all over the former lake bottom. On drained peat sites, with no active cryogenic processes, specific grass meadows on Cryic Sapric Histosols were developed. Totally, permafrost-affected soils occupy 77% of the area (2011). In some part of the lake bed further development of waterlogging leads to the formation of marshy meadows and willow communities where Gleysols prevail. During last twenty years, permafrost degradation has occurred under tall shrub communities, and it will progress in future. Water erosion processes in the drained lake bottom promoted the formation of local hydrographic network. In the stream floodplain grassy willow-stands formed on Fluvisols (3% of the area). The study has been conducted under Clima-East & RFBR 14-05-31111 projects.

  17. Evaluation of the hooghoudt and kirkham tile drain equations in the soil and water assessment tool to simulate tile flow and nitrate-nitrogen.

    Science.gov (United States)

    Moriasi, Daniel N; Gowda, Prasanna H; Arnold, Jeffrey G; Mulla, David J; Ale, Srinivasulu; Steiner, Jean L; Tomer, Mark D

    2013-11-01

    Subsurface tile drains in agricultural systems of the midwestern United States are a major contributor of nitrate-N (NO-N) loadings to hypoxic conditions in the Gulf of Mexico. Hydrologic and water quality models, such as the Soil and Water Assessment Tool, are widely used to simulate tile drainage systems. The Hooghoudt and Kirkham tile drain equations in the Soil and Water Assessment Tool have not been rigorously tested for predicting tile flow and the corresponding NO-N losses. In this study, long-term (1983-1996) monitoring plot data from southern Minnesota were used to evaluate the SWAT version 2009 revision 531 (hereafter referred to as SWAT) model for accurately estimating subsurface tile drain flows and associated NO-N losses. A retention parameter adjustment factor was incorporated to account for the effects of tile drainage and slope changes on the computation of surface runoff using the curve number method (hereafter referred to as Revised SWAT). The SWAT and Revised SWAT models were calibrated and validated for tile flow and associated NO-N losses. Results indicated that, on average, Revised SWAT predicted monthly tile flow and associated NO-N losses better than SWAT by 48 and 28%, respectively. For the calibration period, the Revised SWAT model simulated tile flow and NO-N losses within 4 and 1% of the observed data, respectively. For the validation period, it simulated tile flow and NO-N losses within 8 and 2%, respectively, of the observed values. Therefore, the Revised SWAT model is expected to provide more accurate simulation of the effectiveness of tile drainage and NO-N management practices. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  18. Cleanup Verification Package for the 118-H-6:2, 105-H Reactor Ancillary Support Areas, Below-Grade Structures, and Underlying Soils; the 118-H-6:3, 105-H Reactor Fuel Storage Basin and Underlying Soils; the 118-H-6:6 Fuel Storage Basin Deep Zone Side Slope Soils; the 100-H-9, 100-H-10, and 100-H-13 French Drains; the 100-H-11 and 100-H-12 Expansion Box French Drains; and the 100-H-14 and 100-H-31 Surface Contamination Zones

    International Nuclear Information System (INIS)

    Appel, M.J.

    2006-01-01

    This cleanup verification package documents completion of removal actions for the 105-H Reactor Ancillary Support Areas, Below-Grade Structures, and Underlying Soils (subsite 118-H-6:2); 105-H Reactor Fuel Storage Basin and Underlying Soils (118-H-6:3); and Fuel Storage Basin Deep Zone Side Slope Soils. This CVP also documents remedial actions for the following seven additional waste sties: French Drain C (100-H-9), French Drain D (100-H-10), Expansion Box French Drain E (100-H-11), Expansion Box French Drain F (100-H-12), French Drain G (100-H-13), Surface Contamination Zone H (100-H-14), and the Polychlorinated Biphenyl Surface Contamination Zone (100-H-31)

  19. The Effect of Mechanical Anisotropy and Heterogeneity of Shear Strength Parameters of Soils on Drained Bearing Capacity of Shallow Foundations

    Directory of Open Access Journals (Sweden)

    R. Jamshidi Chenari

    2017-09-01

    Full Text Available Natural formation of soil deposits causes heterogeneity and anisotropy in their strength and stiffness properties. However, most soils in their natural states exhibit some anisotropy with respect to shear strength and heterogeneity with respect to the depth. In this paper, the standard Mohr- Coulomb constitutive law is generalized to anisotropic version in order to consider the effect of cohesion anisotropy of soil. Random field theory coupled with finite difference method was utilized in Monte Carlo simulations with considering the effect of auto-correlation and cross correlation between strength parameters of soil, in order to calculate the bearing capacity of shallow foundation in a strain controlled scheme. The results showed that the bearing capacity of shallow foundation decreases with increasing in variability of strength parameters and increases with increasing in anisotropy ratio.

  20. Hydrologic effects of size and location of harvesting on a large drained pine forest on organic soils

    Science.gov (United States)

    Devendra M. Amatya; Kim Hyunwoo; George M. Chescheir; R. Wayne Nettles Skaggs

    2008-01-01

    A calibrated DRAINWAT model was used to evaluate long -term hydrologic effects of conversion to agriculture of a 30 km2 pine forest on mostly organic soils in North Carolina, USA. Fifty years of weather data were used for determining baseline outflows. Simulation revealed that increased mean annual outflow was significant only for a 75% conversion at both upstream and...

  1. Prefabricated vertical drains, vol. I : engineering guidelines.

    Science.gov (United States)

    1986-09-01

    This volume presents procedures and guidelines applicable to the design and instal : tion of prefabricated vertical drains to accelerate consolidation of soils. The : contents represent the Consultant's interpretation of the state-of-the-art as of : ...

  2. The water quality of streams draining a plantation forest on gley soils: the Nant Tanllwyth, Plynlimon mid-Wales

    Directory of Open Access Journals (Sweden)

    C. Neal

    2004-01-01

    Full Text Available The water quality of the Nant Tanllwyth stream in the Plynlimon region of mid-Wales is related to the key hydrobiogeological controls and the effects of conifer harvesting based on an analysis of rain, cloud, stream and groundwater measurements. The results show the normal patterns of stream water quality response to hydrology. Thus, there is a high damping of atmospheric inputs due to storage in a highly heterogeneous soil and groundwater system. Correspondingly, there is a highly dynamic response for components such as calcium, bicarbonate and aluminium. This response links to the relative inputs of acidic and aluminium-bearing soil waters under high flow conditions and base enriched bicarbonate bearing waters from the groundwater areas under baseflow conditions. The introduction of a deep borehole near the main stem of the river opened up a groundwater flow route to the stream and other parts of the catchment. There were two aspects to this. Firstly, it caused a change to the stream water quality, particularly under baseflow conditions, by increasing the concentrations of calcium and magnesium and by reducing the acidity. The monitoring shows that this change has persisted for over eight years and that there is no sign of reversion to pre-borehole times. Secondly, it caused a change in the groundwater level and chemistry at a borehole on the other side of the river. This feature shows that the fracture system is of hydrogeochemical and hydrogeological complexity. The effects of conifer harvesting are remarkable. At the local scale, felling leads to the expected short term increase in nitrate, ammonium and phosphate from the disturbance of the soil and the reduction in uptake into the vegetation. Correspondingly, there is a reduction in sodium and chloride linked to reduced scavenging of atmospheric inputs from cloud water by the vegetation and also due to increased dilution potential due to reductions in transpiration by the trees. However

  3. Containment vessel drain system

    Science.gov (United States)

    Harris, Scott G.

    2018-01-30

    A system for draining a containment vessel may include a drain inlet located in a lower portion of the containment vessel. The containment vessel may be at least partially filled with a liquid, and the drain inlet may be located below a surface of the liquid. The system may further comprise an inlet located in an upper portion of the containment vessel. The inlet may be configured to insert pressurized gas into the containment vessel to form a pressurized region above the surface of the liquid, and the pressurized region may operate to apply a surface pressure that forces the liquid into the drain inlet. Additionally, a fluid separation device may be operatively connected to the drain inlet. The fluid separation device may be configured to separate the liquid from the pressurized gas that enters the drain inlet after the surface of the liquid falls below the drain inlet.

  4. Flocculation of organic carbon from headwaters to estuary - the impact of soil erosion, water quality and land use on carbon transformation processes in eight streams draining Exmoor, UK

    Science.gov (United States)

    Snoalv, J.; Groeneveld, M.; Quine, T. A.; Tranvik, L.

    2017-12-01

    Flocculation of dissolved organic carbon (DOC) in streams and rivers is a process that contributes to the pool of particulate organic carbon (POC) in the aquatic system. In low-energy waters the increased sedimentation rates of this higher-density fraction of organic carbon (OC) makes POC important in allocating organic carbon into limnic storage, which subsequently influences emissions of greenhouse gases from the continental environment to the atmosphere. Allochthonous OC, derived from the terrestrial environment by soil erosion and litterfall, import both mineral aggregate-bound and free OC into freshwaters, which comprise carbon species of different quality and recalcitrance than autochthonous in-stream produced OC, such as from biofilms, aquatic plants and algae. Increased soil erosion due to land use change (e.g. agriculture, deforestation etc.) influences the input of allochthonous OC, which can lead to increased POC formation and sedimentation of terrestrial OC at flocculation boundaries in the landscape, i.e. where coagulation and flocculation processes are prone to occur in the water column. This study investigates the seasonal variation in POC content and flocculation capacity with respect to water quality (elemental composition) in eight river systems (four agricultural and four wooded streams) with headwaters in Exmoor, UK, that drain managed and non-managed land into Bristol Channel. Through flocculation experiments the samples were allowed to flocculate by treatments with added clay and salt standards that simulate the flocculation processes by 1) increased input of sediment into streams, and 2) saline mixing at the estuarine boundary, in order to quantify floc production and investigate POC quality by each process respectively. The results show how floc production, carbon quality and incorporation (e.g. complexation) of metals and rare earth elements (REE) in produced POC and remaining DOC in solution vary in water samples over the season and how

  5. 216-Z-8 French drain characterization study

    International Nuclear Information System (INIS)

    Marratt, M.C.; Kasper, R.B.; Van Luik, A.E.

    1984-09-01

    The 216-Z-8 French drain study is one of a series of studies examining historical transuranic waste facilities no longer in use at the Hanford Site. The 216-Z-8 French drain underground disposal system consisted of a large settling tank that overflowed into a French drain. The French drain consisted of two large-diameter, gravel filled, vitrified clay pipes placed on end, end-to-end, over a gravel-filled excavation. The top of the drain was sealed with concrete to prevent the upward flow of waste solution. The waste solution discharged to the 216-Z-8 waste disposal system was a neutralized, transuranic recovery process, filter cake, backflush slurry. The primary objective of this study was to determine the distribution of plutonium and americium beneath the French drain. Transuranic activity under the French drain did not exceed 5 nCi/g in the soil samples obtained from a well within 1 m of the drain structure. Conservative estimates indicated that 4 to 5 m 3 of radioactive contaminated sediments, 10 nCi/g may lie directly under the 216-Z-8 French drain. The secondary objective of the study was to evaluate the possibility of a leak in the settling tank. Results from the analysis of soil samples from wells drilled around the settling tank indicated the presence of low-level transuranic contamination (on the order of 0.001 nci/g) in the soil surrounding the tank. However, the distribution of the contamination does not support a leak as a plausible mechanism to account for the observed activity surrounding the tank. The bulk of the plutonium was confirmed to be in the sludge that remained in the tank; thus, no significant environmental impact would be expected even if there has been a leak

  6. Using Smoke Injection in Drains to Identify Potential Preferential Pathways in a Drained Arable Field

    Science.gov (United States)

    Nielsen, M. H.; Petersen, C. T.; Hansen, S.

    2014-12-01

    Macropores forming a continuous pathway between the soil surface and subsurface drains favour the transport of many contaminants from agricultural fields to surface waters. The smoke injection method presented by Shipitalo and Gibbs (2000) used for demonstrating and quantifying such pathways has been further developed and used on a drained Danish sandy loam. In order to identify the preferential pathways to drains, smoke was injected in three 1.15 m deep tile drains (total drain length 93 m), and smoke emitting macropores (SEMP) at the soil surface were counted and characterized as producing either strong or weak plumes compared to reference plumes from 3 and 6 mm wide tubes. In the two situations investigated in the present study - an early spring and an autumn situation, smoke only penetrated the soil surface layer via earthworm burrows located in a 1.0 m wide belt directly above the drain lines. However, it is known from previous studies that desiccation fractures in a dry summer situation also can contribute to the smoke pattern. The distance between SEMP measured along the drain lines was on average 0.46 m whereas the average spacing between SEMP with strong plumes was 2.3 m. Ponded water was applied in 6 cm wide rings placed above 52 burrows including 17 reference burrows which did not emit smoke. Thirteen pathways in the soil were examined using dye tracer and profile excavation. SEMP with strong plumes marked the entrance of highly efficient transport pathways conducting surface applied water and dye tracer into the drain. However, no single burrow was traced all the way from the surface into the drain, the dye patterns branched off in a network of other macropores. Water infiltration rates were significantly higher (P drains and surface waters, pathways being associated primarily with unevenly distributed SEMP producing strong smoke plumes.

  7. High soil solution carbon and nitrogen concentrations in a drained Atlantic bog are reduced to natural levels by 10 years of rewetting

    Science.gov (United States)

    Frank, S.; Tiemeyer, B.; Gelbrecht, J.; Freibauer, A.

    2014-04-01

    Anthropogenic drainage of peatlands releases additional greenhouse gases to the atmosphere, and dissolved carbon (C) and nutrients to downstream ecosystems. Rewetting drained peatlands offers a possibility to reduce nitrogen (N) and C losses. In this study, we investigate the impact of drainage and rewetting on the cycling of dissolved C and N as well as on dissolved gases, over a period of 1 year and a period of 4 months. We chose four sites within one Atlantic bog complex: a near-natural site, two drained grasslands with different mean groundwater levels and a former peat cutting area rewetted 10 years ago. Our results clearly indicate that long-term drainage has increased the concentrations of dissolved organic carbon (DOC), ammonium, nitrate and dissolved organic nitrogen (DON) compared to the near-natural site. DON and ammonium contributed the most to the total dissolved nitrogen. Nitrate concentrations below the mean groundwater table were negligible. The concentrations of DOC and N species increased with drainage depth. In the deeply-drained grassland, with a mean annual water table of 45 cm below surface, DOC concentrations were twice as high as in the partially rewetted grassland with a mean annual water table of 28 cm below surface. The deeply drained grassland had some of the highest-ever observed DOC concentrations of 195.8 ± 77.3 mg L-1 with maximum values of >400 mg L-1. In general, dissolved organic matter (DOM) at the drained sites was enriched in aromatic moieties and showed a higher degradation status (lower DOC to DON ratio) compared to the near-natural site. At the drained sites, the C to N ratios of the uppermost peat layer were the same as of DOM in the peat profile. This suggests that the uppermost degraded peat layer is the main source of DOM. Nearly constant DOM quality through the profile furthermore indicated that DOM moving downwards through the drained sites remained largely biogeochemically unchanged. Unlike DOM concentration, DOM

  8. Small scale soil carbon and moisture gradients in a drained peat bog grassland and their influence on CO2, CH4 and N2O fluxes

    Science.gov (United States)

    Leiber-Sauheitl, K.; Fuß, R.; Freibauer, A.

    2012-04-01

    Due to the UNFCCC report requirements of each country on the emissions of greenhouse gases from key sources the joint research project "Organic Soils" was established in Germany. The project's objective is to improve the data set on greenhousegas emissions from organic soils in Germany. Within 12 German Project Catchments emissions from different types of organic soils, e.g. under different land uses and hydrological conditions, are measured. At the location "Großes Moor" near Gifhorn (Lower Saxony) the effects of small-scale soil organic carbon and groundwater level gradients on the GHG fluxes (CO2, CH4 and N2O) are quantified. The study area is located within a former peat bog altered by drainage and peat cutting, which is currently grassland under extensive agricultural use. The focus of the study is on the acquisition of CO2, CH4 and N2O fluxes on six sites via manual closed chambers. In order to calculate the annual CO2 exchange rate, values are interpolated on a 0.5 hour scale between measurement campaigns. In combination with continually logged meteorological parameters, such as the photosynthetic active radiation as well as air and soil temperatures, we calculate the daily CO2 ecosystem exchange of the different sites. During the 2011 campaign, CO2 was determined as the most important greenhouse gas. The groundwater table was the dominant variable influencing gas emissions. Another important factor was the vegetation composition. In detail, highest CO2 emissions occurred with a water table of 40-50 cm below ground level, temperatures above 10°C and low plant biomass amounts. Due to the more complex formation of N2O by a number of processes, each being promoted by different soil conditions, the measurement of N2O fluxes in the field was complemented by a laboratory experiment. In this, the use of stable isotope tracer techniques enabled us to quantify the contribution of single biochemical pathways to the overall formation of N2O under controlled

  9. Thailand and brain drain

    Directory of Open Access Journals (Sweden)

    Terry Commins

    2009-01-01

    Full Text Available Brain drain has been the subject of research since the 1960s. This research has been hampered by a lack of accurate data from both source and receiving countries on migration and on the losses and gains to developing economies of skilled migration. However, despite these handicaps, research has been able to clearly show that trends are changing and the effect this is having is usually quite different for individual source countries.Thailand, as a developing economy, could be regarded as a source country. Fortunately, Thailand has never ranked highly in terms of brain drain when compared to other states in Asia and while it may not be a significant problem it nonetheless needs to be monitored. Thailand is also somewhat unique in that the migration that has occurred has been almost equally split between secondary and tertiary educated Thais. Thailand also ranks low in terms of tertiary educated population who have migrated when compared to other countries in the region. Globalisation is having a profound effect on the migration of skilled workers. As trade becomes increasingly free, barriers to the movement of services or people are also freed. As the better educated are encouraged to think globally, so too will they be inclined to move globally into the world community.This paper examines Thailand’s position with respect to brain drain, some of the lessons we have learned and some of the steps that are being taken to minimise the impact of the loss of skilled workers, with a particular focus on science and technology. The conclusion is that brain drain should not be viewed as an entirely negative development and that the positive outcomes should be recognised, encouraged and incorporated into policy.

  10. Globalization, Brain Drain, and Development

    OpenAIRE

    Docquier, Frédéric; Rapoport, Hillel

    2012-01-01

    This paper reviews four decades of economics research on the brain drain, with a focus on recent contributions and on development issues. We first assess the magnitude, intensity, and determinants of the brain drain, showing that brain drain (or high-skill) migration is becoming a dominant pattern of international migration and a major aspect of globalization. We then use a stylized growth model to analyze the various channels through which a brain drain affects the sending countries and revi...

  11. HUBUNGAN KEDEKATAN EKOLOGIS ANTARA FAUNA TANAH DENGAN KARAKTERISTIK TANAH GAMBUT YANG DIDRAINASE UNTUK HTI Acacia crassicarpa (Ecological Proximity Relationship Between Soil Fauna and The Characteristics of Drained Peatland for Industrial Plantation

    Directory of Open Access Journals (Sweden)

    Yunita Lisnawati

    2014-10-01

    yang tinggi dan mempunyai tingkat kematangan yang masih rendah.   ABSTRACT Management of peatlands for HTI cultivation of Acacia crassicarpa begins by making drainage ditches and land clearing, followed by the preparation of land for planting. As for the maintenance activity, it includes weed control using herbicides and fertilizer. Management and maintenance activities certainly have implications for the ecological condition of peatlands, where the changes in ecological conditions due to land conversion will impact the abundance and diversity of soil fauna. Abundance and diversity of soil fauna and ecosystem function showed a very complex relationship not widely known this far.  Soil fauna tendency to select certain habitat is affected by several ecological factors, both biotic and abiotic. The study aims to assess the ecological proximity between the characteristics of peatland drained for HTI cultivation of A. crassicarpa and the abundance of soil fauna. The study was conducted in HTI peatlands of PT. Arara Abadi, Rasau Kuning District, Siak Regency, Riau. Soil fauna sampling was conducted by taking soil sample of 25 x 25 x 25 cm in size.  Separation of soil fauna from the soil was performed by a modification to a barlese funnel. Observed variables were the abundance and the diversity of soil fauna, peat maturity (C/N, water contentof peatand ground water table.  For observing ecological proximity, hierarchical analysis was used.  Result showed that the highest of soil fauna abundance was found in A. crassicarpa stand, 2 year’s old of age. The species diversity of soil fauna in research location included as medium abundant by H’ value 1,2. Formicidae was potential become a low level-humidity bioindicators of peatsoil, which described by those pattern : low water content and higher level of peat maturity. Entomobryidae was potential become a high water content  bioindicator and low level of peat maturity.

  12. Thailand and brain drain

    OpenAIRE

    Terry Commins

    2009-01-01

    Brain drain has been the subject of research since the 1960s. This research has been hampered by a lack of accurate data from both source and receiving countries on migration and on the losses and gains to developing economies of skilled migration. However, despite these handicaps, research has been able to clearly show that trends are changing and the effect this is having is usually quite different for individual source countries.Thailand, as a developing economy, could be regarded as a sou...

  13. Short-term effects of biogas digestate and cattle slurry application on greenhouse gas emissions affected by N availability from grasslands on drained fen peatlands and associated organic soils

    Science.gov (United States)

    Eickenscheidt, T.; Freibauer, A.; Heinichen, J.; Augustin, J.; Drösler, M.

    2014-11-01

    A change in German energy policy has resulted in a strong increase in the number of biogas plants in Germany. As a consequence, huge amounts of nutrient-rich residues, the by-products of the fermentative process, are used as organic fertilizers. Drained peatlands are increasingly used to satisfy the huge demand for fermentative substrates (e.g., energy crops, grass silage) and the digestate is returned to the peatlands. However, drained organic soils are considered as hot spots for nitrous oxide (N2O) emissions and organic fertilization is additionally known to increase N2O emissions from managed grasslands. Our study addressed the questions (a) to what extent biogas digestate and cattle slurry application increase N2O and methane (CH4) fluxes as well as the mineral nitrogen use efficiency (NUEmin) and grass yield, and (b) how different soil organic matter contents (SOMs) and nitrogen contents promote the production of N2O. In addition NH3 volatilization was determined at one application event to obtain first clues with respect to the effects of soil and fertilizer types. The study was conducted at two sites within a grassland parcel, which differed in their soil organic carbon (SOC) and N contents. At each site (named Corg-medium and Corg-high) three plots were established: one was fertilized five times with biogas digestate, one with cattle slurry, and the third served as control plot. On each plot, fluxes of N2O and CH4 were measured on three replicates over 2 years using the closed chamber method. For NH3 measurements we used the calibrated dynamic chamber method. On an annual basis, the application of biogas digestate significantly enhanced the N2O fluxes compared to the application of cattle slurry and additionally increased the plant N-uptake and NUEmin. Furthermore, N2O fluxes from the Corg-high treatments significantly exceeded N2O fluxes from the Corg-medium treatments. Annual cumulative emissions ranged from 0.91 ± 0.49 to 3.14 ± 0.91 kg N ha-1 yr-1

  14. The stable stiffness triangle - drained sand during deformation cycles

    DEFF Research Database (Denmark)

    Sabaliauskas, Tomas; Ibsen, Lars Bo

    2017-01-01

    Cyclic, drained sand stiffness was observed using the Danish triaxial appa- ratus. New, deformation dependant soil property (the stable stiffness triangle) was detected. Using the the stable stiffness triangle, secant stiffness of drained sand was plausible to predict (and control) even during ir...... findings can find application in off-shore, seismic and other engi- neering practice, or inspire new branches of research and modelling wherever dynamic, cyclic or transient loaded sand is encountered....

  15. Drains and Drainage Capabilities: Quantitative Analysis of Drain Efficiencies

    Directory of Open Access Journals (Sweden)

    Andaç Aykan

    2016-03-01

    Full Text Available Objective: In this study, it was aimed to compare the efficiency of the same type of but different-sized silicone drains at different surgical procedures. Material and Methods: Twenty-four patients, who had different diagnoses and were operated between 2011 and 2013, were included. In all patients, 7- and 10-mm silicone-ended, Jackson–Pratt drains were used. Drains that were under 30 cc/day removed. The connection tube and perforated silicone end were examined due to the clot content. All drain efficiencies were calculated, and the results were statistically analyzed. Results: Seven of the 24 patients (29.2% were males and 17 (70.8% were females; the mean age was 39.0±11.4 years. Totally, 49 drains were used, of which 25 (51% were 7 mm and 24 (49% were 10 mm in size. Median removal time was the 5th day (2–12 for the 7-mm drains and the 6th day (3–14 for the 10-mm drains. There was no statistically significant difference between the groups for drain removal time (p=0.268. Further, there was no difference at the connection tube and silicone end for clot content between the 7- and 10-mm drains (p=0.58. For the drainage volume and efficiency, no difference was observed between the groups (p=0.146. Conclusion: In this study it was observed that there is no difference in the drainage volume and efficiency between different-sized Jackson–Pratt drains.

  16. Leaching of dissolved phosphorus from tile-drained agricultural areas.

    Science.gov (United States)

    Andersen, H E; Windolf, J; Kronvang, B

    2016-01-01

    We investigated leaching of dissolved phosphorus (P) from 45 tile-drains representing animal husbandry farms in all regions of Denmark. Leaching of P via tile-drains exhibits a high degree of spatial heterogeneity with a low concentration in the majority of tile-drains and few tile-drains (15% in our investigation) having high to very high concentration of dissolved P. The share of dissolved organic P (DOP) was high (up to 96%). Leaching of DOP has hitherto been a somewhat overlooked P loss pathway in Danish soils and the mechanisms of mobilization and transport of DOP needs more investigation. We found a high correlation between Olsen-P and water extractable P. Water extractable P is regarded as an indicator of risk of loss of dissolved P. Our findings indicate that Olsen-P, which is measured routinely in Danish agricultural soils, may be a useful proxy for the P leaching potential of soils. However, we found no straight-forward correlation between leaching potential of the top soil layer (expressed as either degree of P saturation, Olsen-P or water extractable P) and the measured concentration of dissolved P in the tile-drain. This underlines that not only the source of P but also the P loss pathway must be taken into account when evaluating the risk of P loss.

  17. Predicting artificailly drained areas by means of selective model ensemble

    DEFF Research Database (Denmark)

    Møller, Anders Bjørn; Beucher, Amélie; Iversen, Bo Vangsø

    . The approaches employed include decision trees, discriminant analysis, regression models, neural networks and support vector machines amongst others. Several models are trained with each method, using variously the original soil covariates and principal components of the covariates. With a large ensemble...... out since the mid-19th century, and it has been estimated that half of the cultivated area is artificially drained (Olesen, 2009). A number of machine learning approaches can be used to predict artificially drained areas in geographic space. However, instead of choosing the most accurate model....... The study aims firstly to train a large number of models to predict the extent of artificially drained areas using various machine learning approaches. Secondly, the study will develop a method for selecting the models, which give a good prediction of artificially drained areas, when used in conjunction...

  18. Plumbing the brain drain.

    Science.gov (United States)

    Saravia, Nancy Gore; Miranda, Juan Francisco

    2004-08-01

    Opportunity is the driving force of migration. Unsatisfied demands for higher education and skills, which have been created by the knowledge-based global economy, have generated unprecedented opportunities in knowledge-intensive service industries. These multi-trillion dollar industries include information, communication, finance, business, education and health. The leading industrialized nations are also the focal points of knowledge-intensive service industries and as such constitute centres of research and development activity that proactively draw in talented individuals worldwide through selective immigration policies, employment opportunities and targeted recruitment. Higher education is another major conduit of talent from less-developed countries to the centres of the knowledge-based global economy. Together career and educational opportunities drive "brain drain and recirculation". The departure of a large proportion of the most competent and innovative individuals from developing nations slows the achievement of the critical mass needed to generate the enabling context in which knowledge creation occurs. To favourably modify the asymmetric movement and distribution of global talent, developing countries must implement bold and creative strategies that are backed by national policies to: provide world-class educational opportunities, construct knowledge-based research and development industries, and sustainably finance the required investment for these strategies. Brazil, China and India have moved in this direction, offering world-class education in areas crucial to national development, such as biotechnology and information technology, paralleled by investments in research and development. As a result, only a small proportion of the most highly educated individuals migrate from these countries, and research and development opportunities employ national talent and even attract immigrants.

  19. Improved simulation of poorly drained forests using Biome-BGC.

    Science.gov (United States)

    Bond-Lamberty, Ben; Gower, Stith T; Ahl, Douglas E

    2007-05-01

    Forested wetlands and peatlands are important in boreal and terrestrial biogeochemical cycling, but most general-purpose forest process models are designed and parameterized for upland systems. We describe changes made to Biome-BGC, an ecophysiological process model, that improve its ability to simulate poorly drained forests. Model changes allowed for: (1) lateral water inflow from a surrounding watershed, and variable surface and subsurface drainage; (2) adverse effects of anoxic soil on decomposition and nutrient mineralization; (3) closure of leaf stomata in flooded soils; and (4) growth of nonvascular plants (i.e., bryophytes). Bryophytes were treated as ectohydric broadleaf evergreen plants with zero stomatal conductance, whose cuticular conductance to CO(2) was dependent on plant water content. Individual model changes were parameterized with published data, and ecosystem-level model performance was assessed by comparing simulated output to field data from the northern BOREAS site in Manitoba, Canada. The simulation of the poorly drained forest model exhibited reduced decomposition and vascular plant growth (-90%) compared with that of the well-drained forest model; the integrated bryophyte photosynthetic response accorded well with published data. Simulated net primary production, biomass and soil carbon accumulation broadly agreed with field measurements, although simulated net primary production was higher than observed data in well-drained stands. Simulated net primary production in the poorly drained forest was most sensitive to oxygen restriction on soil processes, and secondarily to stomatal closure in flooded conditions. The modified Biome-BGC remains unable to simulate true wetlands that are subject to prolonged flooding, because it does not track organic soil formation, water table changes, soil redox potential or anaerobic processes.

  20. Pesticide transport to tile-drained fields in SWAT model – macropore flow and sediment

    DEFF Research Database (Denmark)

    Lu, Shenglan; Trolle, Dennis; Blicher-Mathiesen, Gitte

    2015-01-01

    Tool (SWAT) to simulate transport of both mobile (e.g. Bentazon) and strongly sorbed (e.g. Diuron) pesticides in tile drains. Macropore flow is initiated when soil water content exceeds a threshold and rainfall intensity exceeds infiltration capacity. The amount of macropore flow is calculated...... to macropore sediment transport. Simulated tile drain discharge, sediment and pesticide loads are calibrated against data from intensively monitored tile-drained fields and streams in Denmark....

  1. Influence of Hudiara Drain Water Irrigation on Trace Elements Load ...

    African Journals Online (AJOL)

    ... Drain Water Irrigation on Trace Elements Load In Soil And Uptake By Vegetables. ... This polluted water not only contains organic matter and crop nutrients but also ... Plant samples were collected at maturity from all the monitoring points. ... (DO), Chemical Oxygen Demand (COD) and Biological Oxygen Demand (BOD) ...

  2. Method of draining water through a solid waste site without leaching

    Science.gov (United States)

    Treat, Russell L.; Gee, Glendon W.; Whyatt, Greg A.

    1993-01-01

    The present invention is a method of preventing water from leaching solid waste sites by preventing atmospheric precipitation from contacting waste as the water flows through a solid waste site. The method comprises placing at least one drain hole through the solid waste site. The drain hole is seated to prevent waste material from entering the drain hole, and the solid waste site cover material is layered and graded to direct water to flow toward the drain hole and to soil beneath the waste site.

  3. Modeling the impact of nitrogen fertilizer application and tile drain configuration on nitrate leaching using SWAT

    Science.gov (United States)

    Recently, the Soil and Water Assessment Tool (SWAT) was revised to improve the partitioning of runoff and tile drainage in poorly drained soils by modifying the algorithm for computing the soil moisture retention parameter. In this study, the revised SWAT model was used to evaluate the sensitivity a...

  4. Closed suction drain with bulb

    Science.gov (United States)

    ... of gloves. Put a new bandage around the drain tube site. Use surgical tape to hold it down ... small amount of redness is normal). There is drainage from the skin around the tube site. There is more tenderness and swelling at ...

  5. Fine root production at drained peatland sites

    Energy Technology Data Exchange (ETDEWEB)

    Finer, L [Finnish Forest Research Inst. (Finland). Joensuu Research Station; Laine, J [Helsinki Univ. (Finland). Dept. of Forest Ecology

    1997-12-31

    The preliminary results of the Finnish project `Carbon balance of peatlands and climate change` show that fine roots play an important role in carbon cycling on peat soils. After drainage the roots of mire species are gradually replaced by the roots of trees and other forest species. Pine fine root biomass reaches a maximum level by the time of crown closure, some 20 years after drainage on pine mire. The aim of this study is to compare the results of the sequential coring method and the ingrowth bag method used for estimating fine root production on three drained peatland sites of different fertility. The results are preliminary and continuation to the work done in the study Pine root production on drained peatlands, which is part of the Finnish project `Carbon cycling on peatlands and climate change`. In this study the fine root biomass was greater on the poor site than on the rich sites. Pine fine root production increased with the decrease in fertility. Root turnover and the production of field layer species were greater on the rich sites than on the poor site. The results suggested that the in growth bag method measured more root activity than the magnitude of production. More than two growing seasons would have been needed to balance the root dynamics in the in growth bags with the surrounding soil. That time would probably have been longer on the poor site than on the rich ones and longer for pine and field layer consisting of dwarf shrubs than for field layer consisting of sedge like species and birch. (11 refs.)

  6. Fine root production at drained peatland sites

    Energy Technology Data Exchange (ETDEWEB)

    Finer, L. [Finnish Forest Research Inst. (Finland). Joensuu Research Station; Laine, J. [Helsinki Univ. (Finland). Dept. of Forest Ecology

    1996-12-31

    The preliminary results of the Finnish project `Carbon balance of peatlands and climate change` show that fine roots play an important role in carbon cycling on peat soils. After drainage the roots of mire species are gradually replaced by the roots of trees and other forest species. Pine fine root biomass reaches a maximum level by the time of crown closure, some 20 years after drainage on pine mire. The aim of this study is to compare the results of the sequential coring method and the ingrowth bag method used for estimating fine root production on three drained peatland sites of different fertility. The results are preliminary and continuation to the work done in the study Pine root production on drained peatlands, which is part of the Finnish project `Carbon cycling on peatlands and climate change`. In this study the fine root biomass was greater on the poor site than on the rich sites. Pine fine root production increased with the decrease in fertility. Root turnover and the production of field layer species were greater on the rich sites than on the poor site. The results suggested that the in growth bag method measured more root activity than the magnitude of production. More than two growing seasons would have been needed to balance the root dynamics in the in growth bags with the surrounding soil. That time would probably have been longer on the poor site than on the rich ones and longer for pine and field layer consisting of dwarf shrubs than for field layer consisting of sedge like species and birch. (11 refs.)

  7. Theoretical computation background for transformation of foundations using pile drains

    Directory of Open Access Journals (Sweden)

    Ter-Martirosyan Zaven

    2017-01-01

    Full Text Available In the design of foundations for buildings and structures of various purposes, including improved risk, weak water-saturated clay soils with low mechanical characteristics are often found on a construction site. One of the possible ways of using them as a foundation is to seal them in various ways, including using pile drains of sand or rock stone material that are capable of both absorbing the load at the base and accelerating the process of filtration consolidation. This paper describes an analytical solution to the problem of interaction between the pile and the mattress with the surrounding soil of the foundation, taking into account the possibility of expanding the pile shaft. Solutions are obtained for determining the stresses in the shaft of the pile drain and in the soil under the mattress. The solution takes into account the influence of the pre-stressed state of the foundation after compaction on the formation of a stress-strain state during the erection and operation of structures. The solutions are relevant for consolidating pile drains made of rubble or for jet grouting piles, the rigidity of which is comparable to the rigidity of the surrounding soil. The paper describes the technique for determining the characteristics of the strength and deformability of the converted foundation and the results of large-scale tests at the experimental site for the construction of a large energy facility in Russia.

  8. Method of processing laundry drain

    Energy Technology Data Exchange (ETDEWEB)

    Sugimoto, Y; Oda, A; Yusa, H; Kitamura, M; Horiuchi, S

    1979-09-28

    Purpose: To subject the laundry drain to flocculation precipitation treatment in the prior stage of an inverse osmotic treatment, and subject only the supernatant to the inverse osmotic treatment and the precipitate directly to the condensation treatment, thereby decreasing the frequency of exchange of the inverse osmotic membranes, and reducing the quantity of purifying water. Method: The laundry drain is supplied to a flocculation precipitation tank, and added and mixed with a flocculant and a neutralizing agent, thus being subjected to a flocculation precipitation treatment. The supernatant is transported to a circulation tank through a transportation pipe, and is subjected to an inverse osmotic treatment in inverse osmotic module through the circulation tank, a filter and a high tension pump, and then returned to the circulation tank. The supernatant is thus concentrated to a predetermined concentration by repeating such operations. On the other hand, the precipitate at the bottom part of the flocculation precipitation tank is supplied through the transportation pipe to an evaporator supply tank together with the concentrate from the drain circulation tank, and evaporated and concentrated in the evaporator.

  9. Rotina computacional para a determinação da velocidade de sedimentação das partículas do solo em suspensão no escoamento superficial Computational routine for the determination of the sedimentation velocity of the soil particles in the drain

    Directory of Open Access Journals (Sweden)

    Luiz F. C. de Oliveira

    2005-04-01

    Full Text Available O presente trabalho teve como objetivo desenvolver uma rotina computacional para a determinação da velocidade de deposição de partículas em suspensão no escoamento superficial, verificar sua aplicação por intermédio de modelo de transporte de sedimentos e comparar os resultados obtidos com dados experimentais. Empregou-se na rotina o processo iterativo de Newton-Rapshon para a solução das equações empregadas na determinação da velocidade de deposição de partículas em suspensão no escoamento superficial, e na solução da equação do transporte de sedimentos empregou-se a técnica das diferenças finitas. Essas rotinas foram empregadas na implementação do modelo MTSES (Modelo para Transporte de Solutos no Solo e no Escoamento Superficial. As velocidades de queda das partículas obtidas pela rotina desenvolvida, em média, foram superestimadas, com erro relativo médio de 0,63%, o que possibilitou a utilização da rotina desenvolvida no MTSES. O modelo MTSES superestimou o total de sedimentos transportados pelo escoamento superficial para todas as intensidades de precipitação empregadas neste estudo, com variações porcentuais de 15,6 a 58,3%.The present work had as objective to develop a computational routine for the determination of the sedimentation velocity in the drain and to verify its application through a model of transport of sediments and to compare the results obtained with experimental data. It was used in the routine the iterative process of Newton-Rapshon for the solution of the equations applied in the determination of the sedimentation velocity in the drain, and on the solution of the transport of sediments equation was applied the technique of the finite differences. Those routines were used in the implementation of the model MTSES (Model for solute transport in the soil and in the drain. The sedimentation velocities obtained by the developed routine were overestimated, with a medium relative error of 0

  10. Americium/curium bushing melter drain tests

    International Nuclear Information System (INIS)

    Smith, M.E.; Hardy, B.J.; Smith, M.E.

    1997-01-01

    Americium and curium were produced in the past at the Savannah River Site (SRS) for research, medical, and radiological applications. They have been stored in a nitric acid solution in an SRS reprocessing facility for a number of years. Vitrification of the americium/curium (Am/Cm) solution will allow the material to be safely stored or transported to the DOE Oak Ridge Reservation. Oak Ridge is responsible for marketing radionuclides for research and medical applications. The bushing melter technology being used in the Am/Cm vitrification research work is also under consideration for the stabilization of other actinides such as neptunium and plutonium. A series of melter drain tests were conducted at the Savannah River Technology Center to determine the relationship between the drain tube assembly operating variables and the resulting pour initiation times, glass flowrates, drain tube temperatures, and stop pour times. Performance criteria such as ability to start and stop pours in a controlled manner were also evaluated. The tests were also intended to provide support of oil modeling of drain tube performance predictions and thermal modeling of the drain tube and drain tube heater assembly. These drain tests were instrumental in the design of subsequent melter drain tube and drain tube heaters for the Am/Cm bushing melter, and therefore in the success of the Am/Cm vitrification and plutonium immobilization programs

  11. Soils

    Science.gov (United States)

    Emily Moghaddas; Ken Hubbert

    2014-01-01

    When managing for resilient forests, each soil’s inherent capacity to resist and recover from changes in soil function should be evaluated relative to the anticipated extent and duration of soil disturbance. Application of several key principles will help ensure healthy, resilient soils: (1) minimize physical disturbance using guidelines tailored to specific soil types...

  12. Development of rationalized system treating floor drain

    International Nuclear Information System (INIS)

    Nakamura, Yasuyuki; Serizawa, Kenichi; Komatsu, Akihiro; Shimizu, Takayuki

    1998-01-01

    Radioactive liquid wastes generated at BWR plants are collected and treated as required. These days, however, generation of floor drain has deceased and HFF (Hollow Fiber Filter) has experienced a wide applicability to several kinds of liquid wastes. We should consider that the floor drain can be mixed and diluted with equipment drain and be purified by HFF. That enables some of the sumps and long priming pipes to be combined. From this point of view, we have developed a highly rationalized waste liquid system. We have evaluated the applicability of this system after an investigation into the generation and properties of floor drain and equipment drain at the latest BWR'S and an on-site test at a typical BWR. (author)

  13. Accounting for the risks of phosphorus losses through tile drains in a phosphorus index.

    Science.gov (United States)

    Reid, D Keith; Ball, Bonnie; Zhang, T Q

    2012-01-01

    Tile drainage systems have been identified as a significant conduit for phosphorus (P) losses to surface water, but P indices do not currently account for this transport pathway in a meaningful way. Several P indices mention tile drains, but most account for either the reduction in surface runoff or the enhanced transport through tiles rather than both simultaneously. A summary of the current state of how tile drains are accounted for within P indices is provided, and the challenges in predicting the risk of P losses through tile drains that are relative to actual losses are discussed. A framework for a component P Index is described, along with a proposal to incorporate predictions of losses through tile drains as a component within this framework. Options for calibrating and testing this component are discussed. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  14. QUALIFIED VERSION OF MIGRATION: BRAIN DRAIN

    Directory of Open Access Journals (Sweden)

    Ayhan GENCLER

    2009-07-01

    Full Text Available Though globalization suggests an international exchange of people besides goods and capital, developed countries often tended to put forward some restrictions on the migration of workers from developed countries. However, there has been an increase in skilled international migration especially during the last two decades. Skilled international migration or brain drain points out the emigration of educated and highly skilled workers. It seems that, in general, developing or underdeveloped countries experience the negative consequences of the brain drain and suffer from the decreases in their human capital. The paper explains the phenomenon of skilled international migration, or brain drain, and summarizes the main global trends in this area.

  15. To determine the slow shearing rate for consolidation drained shear box tests

    Science.gov (United States)

    Jamalludin, Damanhuri; Ahmad, Azura; Nordin, Mohd Mustaqim Mohd; Hashim, Mohamad Zain; Ibrahim, Anas; Ahmad, Fauziah

    2017-08-01

    Slope failures always occur in Malaysia especially during the rainy seasons. They cause damage to properties and fatalities. In this study, a total of 24 one dimensional consolidation tests were carried out on soil samples taken from 16 slope failures in Penang Island and in Baling, Kedah. The slope failures in Penang Island are within the granitic residual soil while in Baling, Kedah they are situated within the sedimentary residual soil. Most of the disturbed soil samples were taken at 100mm depth from the existing soil surface while some soil samples were also taken at 400, 700 and 1000mm depths from the existing soil surface. They were immediately placed in 2 layers of plastic bag to prevent moisture loss. Field bulk density tests were also carried out at all the locations where soil samples were taken. The field bulk density results were later used to re-compact the soil samples for the consolidation tests. The objective of the research is to determine the slow shearing rate to be used in consolidated drained shear box for residual soils taken from slope failures so that the effective shear strength parameters can be determined. One dimensional consolidation tests were used to determine the slow shearing rate. The slow shearing rate found in this study to be used in the consolidated drained shear box tests especially for Northern Malaysian residual soils was 0.286mm/minute.

  16. Drain Back, Low Flow Solar Combi Systems

    DEFF Research Database (Denmark)

    Perers, Bengt; Furbo, Simon; Fan, Jianhua

    2014-01-01

    Drain Back systems with ETC collectors are tested and analyzed in a Danish - Chinese cooperation project. Experiences from early work at DTU, with drain back, low flow systems, was used to design two systems: 1) One laboratory system at DTU and 2) One demonstration system in a single family house...... in Sorö Denmark. Detailed monitoring and modelling of the system in the DTU lab is done to be able to generalize the results, to other climates and loads and to make design optimizations. The advantage with drain back, low flow systems, is that the system can be made more simple with less components...... and that the performance can be enhanced. A combination of the drain back- and system expansion vessel was tested successfully. Small initial problems with installation and proposals for design improvements to avoid these in practice are described in the paper. Installer education and training is an important step to have...

  17. Penrose Drain Migration After Laparoscopic Surgery

    Directory of Open Access Journals (Sweden)

    Pazouki AbdolReza

    2009-05-01

    Full Text Available Laparoscopy has made a revolution in surgical procedures and treatment of various diseases but its complications are still under investigation. Intra-abdominal visceral and vessel injuries, trocar site hernia, and leaving foreign bodies into the peritoneal cavity are among some laparoscopic surgery complications. This is a rare report of Penrose drain migration following incomplete laparoscopic Fundoplication surgery. The patient was a 47- year- old woman, who was a candidate for Touplet Fundoplication via laparoscopic approach due to refractory gastro-esophageal reflux disease (GERD. While wrapping a Penrose drain around the esophagus, the patient had a cardiorespiratory arrest. Attempts to remove the Penrose drain were unsuccessful and the surgical procedure was terminated due to patient's condition. Four months later, after a long period of dysphagia and abdominal pain, the Penrose drain was defecated via rectum.

  18. Brain drain of China and India

    OpenAIRE

    Li, Yuan

    2012-01-01

    Abstract Under the background of globalization, brain drain is a common phenomenon in many countries. Talents flow from developing countries to developed countries, and this phenomenon unavoidably exerts various and profound influences to both the source countries and the receiving countries. This thesis deals with the phenomenon of brain drain with the aim to investigate the phenomenon further and carry out two case studies of China and India. The research method is main...

  19. Necessity of suction drains in gynecomastia surgery.

    Science.gov (United States)

    Keskin, Mustafa; Sutcu, Mustafa; Cigsar, Bulent; Karacaoglan, Naci

    2014-05-01

    The aim of gynecomastia surgery is to restore a normal chest contour with minimal signs of breast surgery. The authors examine the rate of complications in gynecomastia surgery when no closed-suction drains are placed. One hundred thirty-eight consecutive male patients who underwent gynecomastia surgery without drains were retrospectively analyzed to determine whether the absence of drains adversely affected patient outcomes. Patients were managed by ultrasonic-assisted liposuction both with and without the pull-through technique. The mean age of the patients was 29 years, and the mean volume of breast tissue aspirated was 350 mL per beast. Pull-through was needed in 23 cases. There was only 1 postoperative hematoma. These results are comparable with previously published data for gynecomastia surgery in which drains were placed, suggesting that the absence of drains does not adversely affect postoperative recovery. Routine closed-suction drainage after gynecomastia surgery is unnecessary, and it may be appropriate to omit drains after gynecomastia surgery.

  20. How to remove a chest drain.

    Science.gov (United States)

    Allibone, Elizabeth

    2015-10-07

    RATIONALE AND KEY POINTS: This article aims to help nurses to undertake the removal of a chest drain in a safe, effective and patient-centred manner. This procedure requires two practitioners. The chest drain will have been inserted aseptically to remove air, blood, fluid or pus from the pleural cavity. ▶ Chest drains may be small or wide bore depending on the underlying condition and clinical setting. They may be secured with a mattress suture and/or an anchor suture. ▶ Chest drains are usually removed under medical instructions when the patient's lung has inflated, the underlying condition has resolved, there is no evidence of respiratory compromise or failure, and their anticoagulation status has been assessed as satisfactory. ▶ Chest drains secured with a mattress suture should be removed by two practitioners. One practitioner is required to remove the tube and the other to tie the mattress suture (if present) and secure the site. REFLECTIVE ACTIVITY: Clinical skills articles can help update your practice and ensure it remains evidence based. Apply this article to your practice. Reflect on and write a short account of: 1. How reading this article will change your practice. 2. How this article could be used to educate patients with chest drains. Subscribers can upload their reflective accounts at: rcni.com/portfolio .

  1. Soil

    International Nuclear Information System (INIS)

    Freudenschuss, A.; Huber, S.; Riss, A.; Schwarz, S.; Tulipan, M.

    2002-01-01

    Environmental soil surveys in each province of Austria have been performed, soils of about 5,000 sites were described and analyzed for nutrients and pollutants, the majority of these data are recorded in the soil information system of Austria (BORIS) soil database, http://www.ubavie.gv.at/umweltsituation/boden/boris), which also contains a soil map of Austria, data from 30 specific investigations mainly in areas with industry and results from the Austria - wide cesium investigation. With respect to the environmental state of soils a short discussion is given, including two geographical charts, one showing which sites have soil data (2001) and the other the cadmium distribution in top soils according land use (forest, grassland, arable land, others). Information related to the soil erosion, Corine land cover (Europe-wide land cover database), evaluation of pollutants in soils (reference values of As, Cd, Co, Cr, Cu, Hg, Mo, Ni, Se, Pb, Tl, Va, Zn, AOX, PAH, PCB, PCDD/pcdf, dioxin), and relevant Austrian and European standards and regulations is provided. Figs. 2, Tables 4. (nevyjel)

  2. Laparoscopic radical prostatectomy: omitting a pelvic drain

    Directory of Open Access Journals (Sweden)

    David Canes

    2008-03-01

    Full Text Available PURPOSE: Our goal was to assess outcomes of a selective drain placement strategy during laparoscopic radical prostatectomy (LRP with a running urethrovesical anastomosis (RUVA using cystographic imaging in all patients. Materials and Methods: A retrospective chart review was performed for all patients undergoing LRP between January 2003 and December 2004. The anastomosis was performed using a modified van Velthoven technique. A drain was placed at the discretion of the senior surgeon when a urinary leak was demonstrated with bladder irrigation, clinical suspicion for a urinary leak was high, or a complex bladder neck reconstruction was performed. Routine postoperative cystograms were obtained. RESULTS: 208 patients underwent LRP with a RUVA. Data including cystogram was available for 206 patients. The overall rate of cystographic urine leak was 5.8%. A drain was placed in 51 patients. Of these, 8 (15.6% had a postoperative leak on cystogram. Of the 157 undrained patients, urine leak was radiographically visible in 4 (2.5%. The higher leak rate in the drained vs. undrained cohort was statistically significant (p = 0.002. Twenty-four patients underwent pelvic lymph node dissection (8 drained, 16 undrained. Three undrained patients developed lymphoceles, which presented clinically on average 3 weeks postoperatively. There were no urinomas or hematomas in either group. CONCLUSIONS: Routine placement of a pelvic drain after LRP with a RUVA is not necessary, unless the anastomotic integrity is suboptimal intraoperatively. Experienced clinical judgment is essential and accurate in identifying patients at risk for postoperative leakage. When suspicion is low, omitting a drain does not increase morbidity.

  3. Soils

    International Nuclear Information System (INIS)

    Freudenschuss, A.; Huber, S.; Riss, A.; Schwarz, S.; Tulipan, M.

    2001-01-01

    For Austria there exists a comprehensive soil data collection, integrated in a GIS (geographical information system). The content values of pollutants (cadmium, mercury, lead, copper, mercury, radio-cesium) are given in geographical charts and in tables by regions and by type of soil (forests, agriculture, greenland, others) for the whole area of Austria. Erosion effects are studied for the Austrian region. Legal regulations and measures for an effective soil protection, reduction of soil degradation and sustainable development in Austria and the European Union are discussed. (a.n.)

  4. Mechanical decontamination techniques for floor drain systems

    International Nuclear Information System (INIS)

    Palau, G.L.

    1987-01-01

    The unprecedented nature of cleanup activities at Three Mile Island Unit 2 (TMI-2) following the 1979 accident has necessitated the development of new techniques to deal with radiation and contamination in the plant. One of these problems was decontamination of floor drain systems, which had become highly contaminated with various forms of dirt and sludge containing high levels of fission products and fuel from the damaged reactor core. The bulk of this contamination is loosely adherent to the drain pipe walls; however, significant amounts of contamination have become incorporated into pipe wall oxide and corrosion layers and embedded in microscopic pits and fissures in the pipe wall material. The need to remove this contamination was recognized early in the TMI-2 cleanup effort. A program consisting of development and laboratory testing of floor drain decontamination techniques was undertaken early in the cleanup with support from the Electric Power Research Institute (EPRI). Based on this initial research, two techniques were judged to show promise for use at TMI-2: a rotating brush hone system and a high-pressure water mole nozzle system. Actual use of these devices to clean floor drains at TMI-2 has yielded mixed decontamination results. The decontamination effectiveness that has been obtained is highly dependent on the nature of the contamination in the drain pipe and the combination of decontamination techniques used

  5. Liquefaction under drained condition, from the lab to reality ?

    Science.gov (United States)

    Clément, Cécile; Aharonov, Einat; Stojanova, Menka; Toussaint, Renaud

    2015-04-01

    Liquefaction constitutes a significant natural hazard in relation to earthquakes and landslides. This effect can cause buildings to tilt or sink into the soil, mud-volcanoes, floatation of buried objects, long-runout landslides, etc. In this work we present a new understanding regarding the mechanism by which buildings sink and tilt during liquefaction caused by earthquakes. Conventional understanding of liquefaction explains most observed cases as occurring in an undrained, under-compacted, layer of sandy soil saturated with water [1]: According to that understanding, the under compacted sandy layer has the tendency to compact when a load is applied. In our case the load comes from ground shaking during an earthquake. When the soil compacts, the fluid pore pressure rises. Because in undrained conditions the fluid cannot flow out, the pore pressure builds up. The weight of buildings is in this case transferred from the grains of the soil to the pore water. The soil loses its rigidity and it flows like a liquid. From this model scientists made theoretical and empirical laws for geotechnical use and buildings construction. Despite the success of this conventional model in many cases, liquefied soils were also observed under drained conditions, and in previously compacted soils, which doesn't agree with the assumption of the model quoted above. One of the famous liquefaction events is the Kobe port destruction during the 1995 earthquake. A simple calculation of the Deborah number following Goren et al ([2][3]) shows that the undrained constraint was not met below the Kobe port during the 1995 earthquake. We propose another model, of liquefaction in drained granular media. According to our model the mere presence of water in granular media is enough to cause liquefaction during an earthquake, provided that the water reaches close to the surface. Our computations are based on the buoyancy force, and we take into account the static fluid pressure only. For small

  6. Characterizing subsurface water flow to artificial drain lines using fiber-optic distributed temperature sensing

    Science.gov (United States)

    Shults, D.; Brooks, E. S.; Heinse, R.; Keller, C. K.

    2017-12-01

    Over the last several years growers have experienced increasingly wet spring conditions in the Palouse Region located in North Idaho, Eastern Washington and Eastern Oregon. As a result more artificial drain lines are being installed so growers can access their fields earlier in the growing season. Additionally there has been increasing adoption of no-tillage practices among growers in order minimize erosion and runoff in the region. There is a growing body of evidence that suggests long-term no-tillage may lead to the establishment of large macropore networks through increased earthworm activity and the preservation of root channels. These macropore networks, in conjunctions with the presence of artificial drains lines, may create connected preferential flow paths from agricultural fields to receiving streams. This connectivity of flow paths from agricultural fields to receiving water bodies may increase the loading of nutrients and agricultural chemicals as some flow paths may largely bypass soil matrix interaction where materials can be sequestered. Our primary objective for this study was to characterize subsurface flow to two artificial drain lines, one under conventional tillage and the other under no-tillage, using distributed temperature sensing (DTS) technology. During the study (November 2016-April 2017) the near surface soil-water temperature was consistently colder than that of deeper depths. Temperature was thus used as a tracer as snow melt and soil-water moved from the near surface to the drain lines during snowmelt and precipitation events. The spatial and temporal variability of the temperature along the artificial drain line under no-tillage practices was found to be greater than that of the conventional tilled field. It is hypothesized that preferential flow paths are responsible for the increased variability of temperature seen in the drain line under long term no-till management. The temperature along the conventional till drain line showed a

  7. 21 CFR 868.5995 - Tee drain (water trap).

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Tee drain (water trap). 868.5995 Section 868.5995...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5995 Tee drain (water trap). (a) Identification. A tee drain (water trap) is a device intended to trap and drain water that collects in ventilator...

  8. FROM BRAIN DRAIN TO BRAIN NETWORKING

    Directory of Open Access Journals (Sweden)

    Irina BONCEA

    2015-06-01

    Full Text Available Scientific networking is the most accessible way a country can turn the brain drain into brain gain. Diaspora’s members offer valuable information, advice or financial support from the destination country, without being necessary to return. This article aims to investigate Romania’s potential of turning brain drain into brain networking, using evidence from the medical sector. The main factors influencing the collaboration with the country of origin are investigated. The conclusions suggest that Romania could benefit from the diaspora option, through an active implication at institutional level and the implementation of a strategy in this area.

  9. QUALIFIED VERSION OF MIGRATION: BRAIN DRAIN

    OpenAIRE

    Ayhan GENCLER

    2009-01-01

    Though globalization suggests an international exchange of people besides goods and capital, developed countries often tended to put forward some restrictions on the migration of workers from developed countries. However, there has been an increase in skilled international migration especially during the last two decades. Skilled international migration or brain drain points out the emigration of educated and highly skilled workers. It seems tha...

  10. The European Politics of Brain Drain

    DEFF Research Database (Denmark)

    Hasselbalch, Jacob

    This qualitative multi-method studymaps the politics of brain drain at the level of the European Union and follows the evolution of the issue over the last four parliamentary periods. By utilizing a novel combination of interviews with a content and network analysis of parliamentary questions...

  11. Filling, storing and draining. Three key aspects of landslide hydrology

    Science.gov (United States)

    Bogaard, Thom; Greco, Roberto

    2016-04-01

    Rainfall-triggered landslides are among the most widespread hazards in the world. The hydrology in and around a landslide area is key to pore pressure build-up in the soil skeleton which reduces shear strength due to the buoyancy force exerted by water in a saturated soil and to soil suction in an unsaturated soil. Extraordinary precipitation events trigger most of the landslides, but, at the same time, the vast majority of slopes do not fail. The intriguing question is: 'When and where exactly can a slope become triggered to slide and flow downwards?' The objective of this article is to present and discuss landslide hydrology at three scales - pore, hillslope, and catchment - which, taken together, give an overview of this interdisciplinary science. In fact, for rainfall-triggered landslides to occur, an unfavourable hydrological interplay should exist between fast and/or prolonged infiltration, and a relatively 'slow' drainage. The competition of water storage, pressure build-up and the subsequently induced drainage contains the importance of the timing, which is indisputably one of the more delicate but relevant aspects of landslide modelling, the overlay of hydrological processes with different time scales. As slopes generally remain stable, we can argue that effective drainage mechanisms spontaneously develop, as the best for a slope to stay stable is getting rid of the overload of water (above field capacity), either vertically or laterally. So, landslide hydrology could be framed as 'Filling-Storing-Draining'. Obviously, 'Storing' is added to stress the importance of dynamic pressure build-up for slope stability. 'Draining' includes all removal of water from the system (vertical and lateral flow, evaporation and transpiration) and thus pore water pressure release. Furthermore, by addressing landslide hydrology from both earth sciences and soil mechanics perspectives, we aim to manifest the hydrological processes in hillslopes and their influence on behaviour

  12. A Rare Complication of Abdominal Drain: Fallopian Tube Herniation Through the Drain Site

    Directory of Open Access Journals (Sweden)

    Dilek Uygur

    2016-05-01

    Full Text Available Prophylactic drainage of the peritoneal cavity after obstetrical and gynecological surgery is widely practiced. The idea of “when in doubt, drain” is accepted and applied clinically by many surgeons. However, surgically placed drains are not without risk. The present case describes herniation of fallopian tube during the removal of a surgical drain placed after a cesarean section.

  13. A Rare Complication of Abdominal Drain: Fallopian Tube Herniation Through the Drain Site

    OpenAIRE

    Dilek Uygur; Seval Erdinç; Hülya Dede; Ümit Taşdemir; Oktay Kaymak; Nuri Danışman

    2016-01-01

    Prophylactic drainage of the peritoneal cavity after obstetrical and gynecological surgery is widely practiced. The idea of “when in doubt, drain” is accepted and applied clinically by many surgeons. However, surgically placed drains are not without risk. The present case describes herniation of fallopian tube during the removal of a surgical drain placed after a cesarean section.

  14. Establishment and application of the estimation model for pollutant concentrfation in agriculture drain

    Science.gov (United States)

    Li, Qiangkun; Hu, Yawei; Jia, Qian; Song, Changji

    2018-02-01

    It is the key point of quantitative research on agricultural non-point source pollution load, the estimation of pollutant concentration in agricultural drain. In the guidance of uncertainty theory, the synthesis of fertilization and irrigation is used as an impulse input to the farmland, meanwhile, the pollutant concentration in agricultural drain is looked as the response process corresponding to the impulse input. The migration and transformation of pollutant in soil is expressed by Inverse Gaussian Probability Density Function. The law of pollutants migration and transformation in soil at crop different growth periods is reflected by adjusting parameters of Inverse Gaussian Distribution. Based on above, the estimation model for pollutant concentration in agricultural drain at field scale was constructed. Taking the of Qing Tong Xia Irrigation District in Ningxia as an example, the concentration of nitrate nitrogen and total phosphorus in agricultural drain was simulated by this model. The results show that the simulated results accorded with measured data approximately and Nash-Sutcliffe coefficients were 0.972 and 0.964, respectively.

  15. Drain Current Modulation of a Single Drain MOSFET by Lorentz Force for Magnetic Sensing Application.

    Science.gov (United States)

    Chatterjee, Prasenjit; Chow, Hwang-Cherng; Feng, Wu-Shiung

    2016-08-30

    This paper reports a detailed analysis of the drain current modulation of a single-drain normal-gate n channel metal-oxide semiconductor field effect transistor (n-MOSFET) under an on-chip magnetic field. A single-drain n-MOSFET has been fabricated and placed in the center of a square-shaped metal loop which generates the on-chip magnetic field. The proposed device designed is much smaller in size with respect to the metal loop, which ensures that the generated magnetic field is approximately uniform. The change of drain current and change of bulk current per micron device width has been measured. The result shows that the difference drain current is about 145 µA for the maximum applied magnetic field. Such changes occur from the applied Lorentz force to push out the carriers from the channel. Based on the drain current difference, the change in effective mobility has been detected up to 4.227%. Furthermore, a detailed investigation reveals that the device behavior is quite different in subthreshold and saturation region. A change of 50.24 µA bulk current has also been measured. Finally, the device has been verified for use as a magnetic sensor with sensitivity 4.084% (29.6 T(-1)), which is very effective as compared to other previously reported works for a single device.

  16. Carbon accumulation in pristine and drained mires

    Energy Technology Data Exchange (ETDEWEB)

    Maekilae, M.

    2011-07-01

    The carbon accumulation of 73 peat columns from 48 pristine and drained mires was investigated using a total of 367 dates and age-depth models derived from bulk density measurements. Peat columns were collected from mires of varying depth, age, degree of natural state and nutrient conditions in aapa mire and raised bog regions and coastal mires from southern and central Finland and Russian Karelia. Particular attention was paid to the accumulation of carbon over the last 300 years, as this period encompasses the best estimates of the oxic layer (acrotelm) age across the range of sites investigated. In general, drained mires are initially more nutrient-rich than pristine mires. Organic matter decomposes more rapidly at drained sites than at pristine sites, resulting in thinner peat layers and carbon accumulation but a higher dry bulk density and carbon content. The average carbon accumulation was calculated as 24.0 g m-2 yr-1 at pristine sites and 19.4 g m-2 yr-1 at drained sites, while for peat layers younger than 300 years the respective figures were 45.3 and 34.5 g m-2 yr-1 at pristine and drained sites. For the <300-year-old peat layers studied here, the average thickness was 19 cm less and the carbon accumulation rate 10.8 g m-2 yr-1 lower in drained areas than in pristine areas. The amount carbon accumulation of surface peat layers depends upon the mire site type, vegetation and natural state; variations reflect differences in plant communities as well as factors that affect biomass production and decay rates. The highest accumulation rates and thus carbon binding for layers younger than 300 years were measured in the ombrotrophic mire site types (Sphagnum fuscum bog and Sphagnum fuscum pine bog), and the second highest rates in wet, treeless oligotrophic and minerotrophic mire site types. The lowest values of carbon accumulation over the last 300 years were obtained for the most transformed, sparsely forested and forested mire site types, where the water

  17. Processing method of radioactive cleaning drain

    International Nuclear Information System (INIS)

    Otsuka, Shigemitsu; Murakami, Tadashi; Kitao, Hideo

    1998-01-01

    Upon processing of radioactive cleaning drains, contained Co-60 is removed by a selectively adsorbing adsorbent. In addition, after removing suspended materials by a filtering device, Co-60 as predominant nuclides in the drain is selectively adsorbed. The concentration of objective Co-60 is in the order of 0.1 Bq/cc, and non-radioactive metal ions such as Na + ions are present in the order of ppm in addition to Co-60. A granular adsorbent for selectively adsorbing Co-60 is oxine-added activated carbon, and has a grain size of from 20 to 48 mesh. The granular adsorbent is used while being filled in an adsorbing tower. Since a relatively simple device comprising the filtering device and the adsorbing tower in combination is provided, the reduction of the construction cost can be expected. In addition, since no filtering aid is used in the filtering device, the amount of secondary wastes is small. (N.H.)

  18. Percutaneous Retrieval of a Retained Jackson-Pratt Drain Fragment

    International Nuclear Information System (INIS)

    Namyslowski, Jan; Halin, Neil J.; Greenfield, Alan J.

    1996-01-01

    A retained intraabdominal Jackson-Pratt drain fragment was percutaneously retrieved using an inflated angioplasty balloon that had been maneuvered inside of the drain lumen over a hydrophilic-coated steerable guidewire

  19. Device for discharging drain in a control rod driving apparatus

    International Nuclear Information System (INIS)

    Ikeda, Tadasu; Ikuta, Takuzo; Yoshida, Tomiji; Tsukahara, Katsumi.

    1975-01-01

    Object: To efficiently and safely collect and discharge drain by a simple construction in which a drain cover and a drain tank in a control rod driving apparatus are integrally formed, and an overhauling wrench of said apparatus and a drain hose are mounted on the drain tank. Structure: When a mounting bolt is untightened by a torque wrench so as to be removed from a flange surface of the control rod driving apparatus in a nuclear reactor, axial movement of said apparatus is absorbed by a spring so that drain containing a radioactive material is discharged into a drain tank through the flange surface of said apparatus and is then guided into a collecting tank through a drain hose. (Kamimura, M.)

  20. Drained Triaxial Tests on Eastern Scheldt Sand

    DEFF Research Database (Denmark)

    Praastrup, U.; Jakobsen, Kim Parsberg

    In the process of understanding and developing models for geomaterials, the stress-strain behaviour is commonly studied by performing triaxial tests. In the present study static triaxial tests have been performed to gain knowledge of the stress-strain behaviour of frictional materials during...... monotonic loading. The tests reported herein are all drained tests, starting from different initial states of stress and following various stress paths. AIl the tests are performed on reconstituted medium dense specimens of Eastern Scheldt Sand....

  1. QUALIFIED VERSION OF MIGRATION: BRAIN DRAIN

    OpenAIRE

    Gencler, Ayhan

    2009-01-01

    Though globalization suggests an international exchange of people besides goods and capital, developed countries often tended to put forward some restrictions on the migration of workers from developed countries. However, there has been an increase in skilled international migration especially during the last two decades. Skilled international migration or brain drain points out the emigration of educated and highly skilled workers. It seems that, in general, developing or underdeveloped...

  2. Brain drain: Propulsive factors and consequences

    Directory of Open Access Journals (Sweden)

    Dragan ILIC

    2018-01-01

    Full Text Available When speaking about the total number of highly educated individuals’ migration, it is easy to spot that it is rapidly increasing. The brain drain issues should be taken very seriously especially in under developed and in the developing countries, knowing that the human capital is globally mobile and that highly educated individuals can without any issues market their knowledge around the globe. Dealing with it requires a carefully tailored strategy for these countries, which are suffering from severe human capital losses on annual basis. Since the labor markets of today are highly competitive, it is necessary for these countries to secure good advancement and doing business opportunities. The purpose of this research is to provide an insight into the key propulsive factors and potential consequences caused by the brain drain. The method used in order to conduct the research was a carefully designed questionnaire taken by the date subject enrolled at the third and fourth years of state governed and privately owned universities. This research shows that one of the key reasons for brain drain in underdeveloped and in the developing countries is shortage of further educational advancement opportunities.

  3. Fallopian Tube Herniation: An Unusual Complication of Surgical Drain

    OpenAIRE

    Sharma, Lipi; Singh, Alpana; Bhaskaran, Sruthi; Radhika, A. G.; Radhakrishnan, Gita

    2012-01-01

    Background. Surgical drains have been used since time immemorial, but their use is not without complications. By presenting this case we aim to describe an uncommon complication of herniation of fallopian tube following the simple procedure of surgical drain removal. Case Presentation. This case describes a 23-year G2P1L1 who underwent an emergency cesarean section for obstructed labor with intraperitoneal drain insertion. The patient had an uneventful postoperative period, drain was removed ...

  4. Fallopian Tube Herniation through Left Sided Abdominal Drain Site.

    Science.gov (United States)

    Hussain, Khalid; Masood, Jovaria

    2016-06-01

    Intra-abdominal drains have been used since long to prevent intra-abdominal collection, and detect any anastomotic leaks. We report a case of left sided fallopian tube herniation from a left lower abdominal drain site in a 27-year female who underwent caesarian section for breach presentation. Several complications related to drain usage has been described but left sided fallopian tube prolapse through drain site has not been reported in literature.

  5. 46 CFR 45.157 - Scuppers and gravity drains.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Scuppers and gravity drains. 45.157 Section 45.157 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) LOAD LINES GREAT LAKES LOAD LINES Conditions of Assignment § 45.157 Scuppers and gravity drains. Scuppers and gravity deck drains from spaces...

  6. Remote sensing for assessing the zone of benefit where deep drains improve productivity of land affected by shallow saline groundwater.

    Science.gov (United States)

    Kobryn, H T; Lantzke, R; Bell, R; Admiraal, R

    2015-03-01

    The installation of deep drains is an engineering approach to remediate land salinised by the influence of shallow groundwater. It is a costly treatment and its economic viability is, in part, dependent on the lateral extent to which the drain increases biological productivity by lowering water tables and soil salinity (referred to as the drains' zone of benefit). Such zones may be determined by assessing the biological productivity response of adjacent vegetation over time. We tested a multi-temporal satellite remote sensing method to analyse temporal and spatial changes in vegetation condition surrounding deep drainage sites at five locations in the Western Australian wheatbelt affected by dryland salinity-Morawa, Pithara, Beacon, Narembeen and Dumbleyung. Vegetation condition as a surrogate for biological productivity was assessed by Normalised Difference Vegetation Index (NDVI) during the peak growing season. Analysis was at the site scale within a 1000 m buffer zone from the drains. There was clear evidence of NDVI increasing with elevation, slope and distance from the drain. After accounting for elevation, slope and distance from the drain, there was a significant increase in NDVI across the five locations after installation of deep drains. Changes in NDVI after drainage were broadly consistent with measured changes at each site in groundwater levels after installation of the deep drains. However, this study assessed the lateral extent of benefit for biological productivity and gave a measure of the area of benefit along the entire length of the drain. The method demonstrated the utility of spring NDVI images for rapid and relatively simple assessment of the change in site condition after implementation of drainage, but approaches for further improvement of the procedure were identified. Copyright © 2014 Elsevier Ltd. All rights reserved.

  7. MEDICAL BRAIN DRAIN - A THEORETICAL APPROACH

    Directory of Open Access Journals (Sweden)

    Boncea Irina

    2013-07-01

    Full Text Available Medical brain drain is defined as the migration of health personnel from developing countries to developed countries and between industrialized nations in search for better opportunities. This phenomenon became a global growing concern due to its impact on both the donor and the destination countries. This article aims to present the main theoretical contributions starting from 1950 until today and the historical evolution, in the attempt of correlating the particular case of medical brain drain with the theory and evolution of the brain drain in general. This article raises questions and offers answers, identifies the main issues and looks for possible solutions in order to reduce the emigration of medical doctors. Factors of influence include push (low level of income, poor working conditions, the absence of job openings and social recognition, oppressive political climate and pull (better remuneration and working conditions, prospects for career development, job satisfaction, security factors. Developing countries are confronting with the loss of their most valuable intellectuals and the investment in their education, at the benefit of developed nations. An ethical debate arises as the disparities between countries increases, industrialized nations filling in the gaps in health systems with professionals from countries already facing shortages. However, recent literature emphasizes the possibility of a “beneficial brain drain” through education incentives offered by the emigration prospects. Other sources of “brain gain” for donor country are the remittances, the scientific networks and return migration. Measures to stem the medical brain drain involve the common effort and collaboration between developing and developed countries and international organizations. Measures adopted by donor countries include higher salaries, better working conditions, security, career opportunities, incentives to stimulate return migration. Destination

  8. Soil magnetic susceptibility: A quantitative proxy of soil drainage for use in ecological restoration

    Science.gov (United States)

    Grimley, D.A.; Wang, J.-S.; Liebert, D.A.; Dawson, J.O.

    2008-01-01

    Flooded, saturated, or poorly drained soils are commonly anaerobic, leading to microbially induced magnetite/maghemite dissolution and decreased soil magnetic susceptibility (MS). Thus, MS is considerably higher in well-drained soils (MS typically 40-80 ?? 10-5 standard international [SI]) compared to poorly drained soils (MS typically 10-25 ?? 10-5 SI) in Illinois, other soil-forming factors being equal. Following calibration to standard soil probings, MS values can be used to rapidly and precisely delineate hydric from nonhydric soils in areas with relatively uniform parent material. Furthermore, soil MS has a moderate to strong association with individual tree species' distribution across soil moisture regimes, correlating inversely with independently reported rankings of a tree species' flood tolerance. Soil MS mapping can thus provide a simple, rapid, and quantitative means for precisely guiding reforestation with respect to plant species' adaptations to soil drainage classes. For instance, in native woodlands of east-central Illinois, Quercus alba , Prunus serotina, and Liriodendron tulipifera predominantly occur in moderately well-drained soils (MS 40-60 ?? 10-5 SI), whereas Acer saccharinum, Carya laciniosa, and Fraxinus pennsylvanica predominantly occur in poorly drained soils (MS Urbana, IL, U.S.A.). Through use of soil MS maps calibrated to soil drainage class and native vegetation occurrence, restoration efforts can be conducted more successfully and species distributions more accurately reconstructed at the microecosystem level. ?? 2008 Society for Ecological Restoration International.

  9. A large-strain radial consolidation theory for soft clays improved by vertical drains

    OpenAIRE

    Geng, X; Yu, H-S

    2017-01-01

    A system of vertical drains with combined vacuum and surcharge preloading is an effective solution for promoting radial flow, accelerating consolidation. However, when a mixture of soil and water is deposited at a low initial density, a significant amount of deformation or surface settlement occurs. Therefore, it is necessary to introduce large-strain theory, which has been widely used to manage dredged disposal sites in one-dimensional theory, into radial consolidation theory. A governing eq...

  10. A large strain radial consolidation theory for soft clays improved by vertical drains\\ud

    OpenAIRE

    Geng, Xueyu; Yu, Hai-sui

    2017-01-01

    A system of vertical drains with combined vacuum and surcharge preloading is an effective 10 solution for promoting radial flow, accelerating consolidation. However, when a mixture of soil and\\ud 11 water is deposited at a low initial density, a significant amount of deformation or surface settlement 12 occurs. Therefore, it is necessary to introduce large strain theory, which has been widely used to manage\\ud 13 dredged disposal sites in one-dimensional theory, into radial consolidation theo...

  11. A prospective randomized study of use of drain versus no drain after burr-hole evacuation of chronic subdural hematoma.

    Science.gov (United States)

    Singh, Amit Kumar; Suryanarayanan, Bhaskar; Choudhary, Ajay; Prasad, Akhila; Singh, Sachin; Gupta, Laxmi Narayan

    2014-01-01

    Chronic subdural hematoma (CSDH) recurs after surgical evacuation in 5-30% of patients. Inserting subdural drain might reduce the recurrence rate, but is not commonly practiced. There are few prospective studies to evaluate the effect of subdural drains. A prospective randomized study to investigate the effect of subdural drains in the on recurrence rates and clinical outcome following burr-hole drainage (BHD) of CSDH was undertaken. During the study period, 246 patients with CSDH were assessed for eligibility. Among 200 patients fulfilling the eligibility criteria, 100 each were assigned to "drain group" (drain inserted into the subdural space following BHD) and "without drain group" (subdural drain was not inserted following BHD) using random allocation software. The primary end point was recurrence needing re-drainage up to a period of 6 months from surgery. Recurrence occurred in 9 of 100 patients with a drain, and 26 of 100 patients in without drain group (P = 0.002). The mortality was 5% in patients with drain and 4% in patients without drain group (P = 0.744). The medical and surgical complications were comparable between the two study groups. Use of a subdural drain after burr-hole evacuation of a CSDH reduces the recurrence rate and is not associated with increased complications.

  12. Hot moments of N2O transformation and emission in tropical soils from the Pantanal and the Amazon (Brazil)

    DEFF Research Database (Denmark)

    Liengaard, Lars; Figueiredo, Viviane; Markfoged, Rikke

    2014-01-01

    Tropical wetland soils emit large amounts of nitrous oxide (N2O), especially following wetting of drained soil. We investigated seasonally drained wetland soils from the Pantanal and the Amazon, both with a natural high nitrate content and low pH. Here we report the effect of wetting on the produ......Tropical wetland soils emit large amounts of nitrous oxide (N2O), especially following wetting of drained soil. We investigated seasonally drained wetland soils from the Pantanal and the Amazon, both with a natural high nitrate content and low pH. Here we report the effect of wetting...

  13. Cryogenic Fuel Tank Draining Analysis Model

    Science.gov (United States)

    Greer, Donald

    1999-01-01

    One of the technological challenges in designing advanced hypersonic aircraft and the next generation of spacecraft is developing reusable flight-weight cryogenic fuel tanks. As an aid in the design and analysis of these cryogenic tanks, a computational fluid dynamics (CFD) model has been developed specifically for the analysis of flow in a cryogenic fuel tank. This model employs the full set of Navier-Stokes equations, except that viscous dissipation is neglected in the energy equation. An explicit finite difference technique in two-dimensional generalized coordinates, approximated to second-order accuracy in both space and time is used. The stiffness resulting from the low Mach number is resolved by using artificial compressibility. The model simulates the transient, two-dimensional draining of a fuel tank cross section. To calculate the slosh wave dynamics the interface between the ullage gas and liquid fuel is modeled as a free surface. Then, experimental data for free convection inside a horizontal cylinder are compared with model results. Finally, cryogenic tank draining calculations are performed with three different wall heat fluxes to demonstrate the effect of wall heat flux on the internal tank flow field.

  14. Roundtable. Strategies to discourage brain drain.

    Science.gov (United States)

    Kupfer, Linda; Hofman, Karen; Jarawan, Raya; McDermott, Jeanne; Bridbord, Ken

    2004-08-01

    Building health research expertise in developing countries often requires personnel to receive training beyond national borders. For research funding agencies that sponsor this type of training, a major goal is to ensure that trainees return to their country of origin: attaining this objective requires the use of proactive strategies. The strategies described were developed under the extramural acquired immunodeficiency syndrome (AIDS) International Training and Research Program (AITRP) funded by the Fogarty International Center (FIC) at the National Institutes of Health, United States. This programme supports universities in the United States that provide research training to scientists from developing countries to enable them to address the global epidemic of human immunodeficiency virus (HIV)/AIDS and the related tuberculosis (TB) epidemic. This paper describes the strategies employed to discourage brain drain by the principle investigators (PIs) of five of the longest-funded AITRPs (funded for 15 years). Long-term trainees in these programmes spent from 11 to 96 months (an average of 26 months) studying. Using scientific, political and economic strategies that address brain drain issues, PIs working in AITRPs have attained an average rate of return home for their trainees of 80%.

  15. Reduction of the Shear Strength of Soils in the Niger Delta Area of ...

    African Journals Online (AJOL)

    Evaluation of the effects of crude oil pollution on the engineering properties of the affected soils and comparison with the engineering properties of unpolluted soils of similar soil structure within the same zone was carried out. Decrease in values of un-drained cohesion, un-drained angle of internal friction, optimum moisture ...

  16. Land use of drained peatlands: Greenhouse gas fluxes, plant production, and economics.

    Science.gov (United States)

    Kasimir, Åsa; He, Hongxing; Coria, Jessica; Nordén, Anna

    2017-10-10

    Drained peatlands are hotspots for greenhouse gas (GHG) emissions, which could be mitigated by rewetting and land use change. We performed an ecological/economic analysis of rewetting drained fertile peatlands in a hemiboreal climate using different land use strategies over 80 years. Vegetation, soil processes, and total GHG emissions were modeled using the CoupModel for four scenarios: (1) business as usual-Norway spruce with average soil water table of -40 cm; (2) willow with groundwater at -20 cm; (3) reed canary grass with groundwater at -10 cm; and (4) a fully rewetted peatland. The predictions were based on previous model calibrations with several high-resolution datasets consisting of water, heat, carbon, and nitrogen cycling. Spruce growth was calibrated by tree-ring data that extended the time period covered. The GHG balance of four scenarios, including vegetation and soil, were 4.7, 7.1, 9.1, and 6.2 Mg CO 2 eq ha -1  year -1 , respectively. The total soil emissions (including litter and peat respiration CO 2 + N 2 O + CH 4 ) were 33.1, 19.3, 15.3, and 11.0 Mg CO 2 eq ha -1  year -1 , respectively, of which the peat loss contributed 35%, 24%, and 7% of the soil emissions for the three drained scenarios, respectively. No peat was lost for the wet peatland. It was also found that draining increases vegetation growth, but not as drastically as peat respiration does. The cost-benefit analysis (CBA) is sensitive to time frame, discount rate, and carbon price. Our results indicate that the net benefit was greater with a somewhat higher soil water table and when the peatland was vegetated with willow and reed canary grass (Scenarios 2 and 3). We conclude that saving peat and avoiding methane release using fairly wet conditions can significantly reduce GHG emissions, and that this strategy should be considered for land use planning and policy-making. © 2017 John Wiley & Sons Ltd.

  17. Defining Effective Salt Leaching Regions Between Drains

    OpenAIRE

    ANAPALI, Ömer; ŞAHİN, Üstün; ÖZTAŞ, Taşkın; HANAY, Abdurrahman

    2014-01-01

    The application of sufficient amounts of leaching water by means of an effective method is very important in the management and reclamation of saline and sodic soils. Reclamation cannot be achieved with insufficient leaching water application, while excess water application may cause severe problems in soil. Knowledge of the leaching regions and intensities may help to control the amounts of leaching water through effective leaching methods in areas of limited leaching. This study was und...

  18. Brain drain from developing countries: how can brain drain be converted into wisdom gain?

    OpenAIRE

    Dodani, Sunita; LaPorte, Ronald E

    2005-01-01

    Brain drain is defined as the migration of health personnel in search of the better standard of living and quality of life, higher salaries, access to advanced technology and more stable political conditions in different places worldwide. This migration of health professionals for better opportunities, both within countries and across international borders, is of growing concern worldwide because of its impact on health systems in developing countries. Why do talented people leave their count...

  19. Generation of airborne Listeria innocua from model floor drains.

    Science.gov (United States)

    Berrang, Mark E; Frank, Joseph F

    2012-07-01

    Listeria monocytogenes can colonize floor drains in poultry processing and further processing facilities, remaining present even after cleaning and disinfection. Therefore, during wash down, workers exercise caution to avoid spraying hoses directly into drains in an effort to prevent the escape and transfer of drain microflora to food contact surfaces. The objective of this study was to examine the extent to which an inadvertent water spray into a colonized floor drain can cause the spread of airborne Listeria. Listeria innocua was used to inoculate a polyvinyl chloride model floor drain, resulting in approximately 10(8) cells per ml of phosphate-buffered saline and 10(4) attached cells per square centimeter of inner surface. Each model drain was subjected to a 2-s spray of tap water at 68.9 kPa from a distance of 1 m. Drains were sprayed while filled and again after emptying. Airborne cells were collected by using sedimentation plates containing Listeria selective agar which were placed on the floor and walls of a contained room at incremental horizontal and vertical distances of 0.6, 1.2, 2.4, or 4.0 m from the drain. Sedimentation plates were exposed for 10 min. A mechanical sampler was used to also collect air by impaction on the surface of Listeria selective agar to determine the number of cells per liter of air. The experiment was conducted in triplicate rooms for each of four replications. L. innocua was detected on sedimentation plates on the floor as far as 4.0 m from the drain and on walls as high as 2.4 m above the floor and 4 m from the drain. A 2-s spray with a water hose into a contaminated drain can cause airborne spread of Listeria, resulting in the potential for cross-contamination of food contact surfaces, equipment, and exposed product.

  20. 241-AY-102 Leak Detection Pit Drain Line Inspection Report

    International Nuclear Information System (INIS)

    Boomer, Kayle D.; Engeman, Jason K.; Gunter, Jason R.; Joslyn, Cameron C.; Vazquez, Brandon J.; Venetz, Theodore J.; Garfield, John S.

    2014-01-01

    This document provides a description of the design components, operational approach, and results from the Tank AY-102 leak detection pit drain piping visual inspection. To perform this inspection a custom robotic crawler with a deployment device was designed, built, and operated by IHI Southwest Technologies, Inc. for WRPS to inspect the 6-inch leak detection pit drain line

  1. Horner's syndrome caused by an intercostal chest drain.

    OpenAIRE

    Campbell, P; Neil, T; Wake, P N

    1989-01-01

    Horner's syndrome occurred in a young woman as a complication of the treatment of a traumatic pneumothorax with an intercostal drain. The nerve damage probably occurred when the lung had fully re-expanded, pressing the tip of the intercostal drain, lying at the apex of the pleural cavity, on to the sympathetic chain.

  2. Rethinking "Brain Drain" in the Era of Globalisation

    Science.gov (United States)

    Rizvi, Fazal

    2005-01-01

    This paper discusses a range of issues concerning the idea of "brain drain" within the context of recent thinking on transnational mobility. It argues that the traditional analyses of brain drain are not sufficient, and that we can usefully approach the topic from a postcolonial perspective concerned with issues of identity, national…

  3. A new specifically designed forceps for chest drain insertion.

    LENUS (Irish Health Repository)

    Andrews, Emmet

    2012-02-03

    Insertion of a chest drain can be associated with serious complications. It is recommended that the drain is inserted with blunt dissection through the chest wall but there is no specific instrument to aid this task. We describe a new reusable forceps that has been designed specifically to facilitate the insertion of chest drains.A feasibility study of its use in patients who required a chest drain as part of elective cardiothoracic operations was undertaken. The primary end-point was successful and accurate placement of the drain. The operators also completed a questionnaire rating defined aspects of the procedure. The new instrument was used to insert the chest drain in 30 patients (19 male, 11 female; median age 61.5 years (range 16-81 years)). The drain was inserted successfully without the trocar in all cases and there were no complications. Use of the instrument rated as significantly easier relative to experience of previous techniques in all specified aspects. The new device can be used to insert intercostal chest drains safely and efficiently without using the trocar or any other instrument.

  4. The health workforce crisis: the brain drain scourge.

    Science.gov (United States)

    Ike, Samuel O

    2007-01-01

    The magnitude of the health workforce crisis engendered by brain drain particularly in Africa, and nay more especially Nigeria, has been assuming increasingly alarming proportions in the past three decades. The challenge it poses in meeting the manpower needs in the healthcare sector as well as in the larger economy of the sending countries is enormous. This paper thus sets out to highlight the scope of this brain drain, its effects and the reasons sustaining it, as well as makes concrete suggestions to help stern the tide. A review of the literature on brain drain with particular emphasis on the health workforce sector was done, with focus on Africa, and specifically Nigeria. Literature search was done using mainly the Medline, as well as local journals. The historical perspectives, with the scope of external and internal brain drain are explored. The glaring effects of brain drain both in the global workforce terrain and specifically in the health sectors are portrayed. The countries affected most and the reasons for brain drain are outlined. Strategic steps to redress the brain drain crisis are proffered in this paper. The health workforce crisis resulting from brain drain must be brought to the front-burner of strategic policy decisions leading to paradigm shift in political, social and economic conditions that would serve as incentives to curb the scourge.

  5. Analytical solutions for a single vertical drain with time-dependent vacuum combined surcharge preloading in membrane and membraneless systems

    International Nuclear Information System (INIS)

    Geng, X Y; Indraratna, B; Rujikiatkamjorn, C

    2010-01-01

    Vertical drains combined with vacuum pressure and surcharge preloading are widely used to accelerate the consolidation process of soft clay in order to decrease the pore pressure as well as to increase the effective stress. Currently there are two types of vacuum preloading systems commercially available; (a) membrane system with an airtight membrane over the drainage layer and, (b) membraneless system where a vacuum system is connected to individual drain. Their effectiveness varies from site to site depending on the type of soil treated and the characteristics of the drain-vacuum system. This study presents the analytical solutions of vertical drains with vacuum preloading for both membrane and membraneless systems. According to the field and laboratory observations, the vacuum in both of the membraneless and membrane system was assumed to be decreasing along the drain whereas in the membrane system, it was maintained at a constant level. This model was verified by using the measured settlements and excess pore pressures obtained from large-scale laboratory testing and case studies in Australia. The analytical solutions improved the accuracy of predicting the dissipation of pore water pressure and the associated settlement. The effects of the permeability of the sand blanket in a membrane system and the possible loss of vacuum were also discussed.

  6. App-assisted external ventricular drain insertion.

    Science.gov (United States)

    Eftekhar, Behzad

    2016-09-01

    The freehand technique for insertion of an external ventricular drain (EVD) is based on fixed anatomical landmarks and does not take individual variations into consideration. A patient-tailored approach based on augmented-reality techniques using devices such as smartphones can address this shortcoming. The Sina neurosurgical assist (Sina) is an Android mobile device application (app) that was designed and developed to be used as a simple intraoperative neurosurgical planning aid. It overlaps the patient's images from previously performed CT or MRI studies on the image seen through the device camera. The device is held by an assistant who aligns the images and provides information about the relative position of the target and EVD to the surgeon who is performing EVD insertion. This app can be used to provide guidance and continuous monitoring during EVD placement. The author describes the technique of Sina-assisted EVD insertion into the frontal horn of the lateral ventricle and reports on its clinical application in 5 cases as well as the results of ex vivo studies of ease of use and precision. The technique has potential for further development and use with other augmented-reality devices.

  7. Carbon dioxide emissions and nutrition on a drained pine mire - a case study

    Energy Technology Data Exchange (ETDEWEB)

    Hartman, M; Karsisto, M; Kaunisto, S [Finnish Forest Research Inst., Vantaa (Finland). Vantaa Research Centre

    1997-12-31

    Drainage of boreal peatlands intensify aerobic decomposition and carbon dioxide emission from the peat substrate and increase tree growth. CO{sub 2} emission rates depend on the ground water level and the soil temperature. Predicted rises in mean air temperatures due to anthropogenically induced climate change are expected to further increase carbon dioxide emission from drained boreal peatlands. The role of added nutrients is somewhat vague. The purpose of this presentation is to give some preliminary results on microbial biomass carbon and on carbon dioxide output/input relationship on a pine mire. (6 refs.)

  8. Carbon dioxide emissions and nutrition on a drained pine mire - a case study

    Energy Technology Data Exchange (ETDEWEB)

    Hartman, M.; Karsisto, M.; Kaunisto, S. [Finnish Forest Research Inst., Vantaa (Finland). Vantaa Research Centre

    1996-12-31

    Drainage of boreal peatlands intensify aerobic decomposition and carbon dioxide emission from the peat substrate and increase tree growth. CO{sub 2} emission rates depend on the ground water level and the soil temperature. Predicted rises in mean air temperatures due to anthropogenically induced climate change are expected to further increase carbon dioxide emission from drained boreal peatlands. The role of added nutrients is somewhat vague. The purpose of this presentation is to give some preliminary results on microbial biomass carbon and on carbon dioxide output/input relationship on a pine mire. (6 refs.)

  9. Decommissioning of fast reactors after sodium draining

    International Nuclear Information System (INIS)

    2009-11-01

    Acknowledging the importance of passing on knowledge and experience, as well mentoring the next generation of scientists and engineers, and in response to expressed needs by Member States, the IAEA has undertaken concrete steps towards the implementation of a fast reactor data retrieval and knowledge preservation initiative. Decommissioning of fast reactors and other sodium bearing facilities is a domain in which considerable experience has been accumulated. Within the framework and drawing on the wide expertise of the Technical Working Group on Fast Reactors (TWG-FR), the IAEA has initiated activities aiming at preserving the feedback (lessons learned) from this experience and condensing those to technical recommendations on fast reactor design features that would ease their decommissioning. Following a recommendation by the TWG-FR, the IAEA had convened a topical Technical Meeting (TM) on 'Operational and Decommissioning Experience with Fast Reactors', hosted by CEA, Centre d'Etudes de Cadarache, France, from 11 to 15 March 2002 (IAEA-TECDOC- 1405). The participants in that TM exchanged detailed technical information on fast reactor operation and decommissioning experience with various sodium cooled fast reactors, and, in particular, reviewed the status of the various decommissioning programmes. The TM concluded that the decommissioning of fast reactors to reach safe enclosure presented no major difficulties, and that this had been accomplished mainly through judicious adaptation of processes and procedures implemented during the reactor operation phase, and the development of safe sodium waste treatment processes. However, the TM also concluded that, on the path to achieving total dismantling, challenges remain with regard to the decommissioning of components after sodium draining, and suggested that a follow-on TM be convened, that would provide a forum for in-depth scientific and technical exchange on this topic. This publication constitutes the Proceedings of

  10. Preferential transport of isoproturon at a plot scale and a field scale tile-drained site

    Science.gov (United States)

    Zehe, Erwin; Flühler, Hannes

    2001-06-01

    Irrigation experiments using the tracers Brilliant Blue (BB) and Bromide (Br) were conducted on three plots of 1.4×1.4 m 2 (plot scale) and a field scale subsurface drained test site (900 m 2) to clarify mechanisms causing rapid transport of surface applied Isoproturon (IPU) during preferential flow events. One of the small plots (site 10) and the field scale test site are located on the same field. One day after irrigation of the plot scale sites the Br and IPU concentration in two vertical soil profiles as well as the macroporousity on separate profiles and hydraulic properties of single macropores were determined. During irrigation of the field scale test site discharge, soil moisture as well as the concentration of IPU and Br in the drainage outlet were measured. Preferential flow in deep penetrating earthworm burrows caused a fast breakthrough of IPU and Br into the tile drain (1.2 m depth) at the field scale site as well as leaching of IPU into the subsoil (>0.8 m) at site 10. The results suggest a hierarchy of preconditions for the occurrence of preferential flow events of which a sufficient number of deep penetrating macropores interconnected to the soil surface seems to be the most important one. Moreover there is evidence that facilitated transport of IPU attached to mobile soil particles occurred during the preferential flow events at the field scale site and site 10. The susceptibility for preferential flow as well as the susceptibility for facilitated transport appear to be intrinsic properties of the investigated soil.

  11. Advances in chest drain management in thoracic disease

    Science.gov (United States)

    George, Robert S.

    2016-01-01

    An adequate chest drainage system aims to drain fluid and air and restore the negative pleural pressure facilitating lung expansion. In thoracic surgery the post-operative use of the conventional underwater seal chest drainage system fulfills these requirements, however they allow great variability amongst practices. In addition they do not offer accurate data and they are often inconvenient to both patients and hospital staff. This article aims to simplify the myths surrounding the management of chest drains following chest surgery, review current experience and explore the advantages of modern digital chest drain systems and address their disease-specific use. PMID:26941971

  12. Shearon Harris steam generator channel head drain line leakage

    International Nuclear Information System (INIS)

    Bauer, P.A.

    1992-01-01

    All three Shearon Harris steam generators were equipped with Inconel 600 drain penetrations inserted into clearance holes on the bottom center line of the plenums, roll expanded into the plenum shell, and seal welded to the stainless steel cladding. Eddy current inspections showed axial cracks in the drain lines of B and C generators, but not on the leaking A generator. The drain lines of the three generators were repaired by cutting off the pipe under the plenum, applying Inconel 600 cladding to the underside of the plenum by a temper bead process, spot facing the overlay cladding and welding a new Inconel 600 pipe coupling to the clad surface. 3 figs

  13. N loss to drain flow and N2O emissions from a corn-soybean rotation with winter rye.

    Science.gov (United States)

    Gillette, K; Malone, R W; Kaspar, T C; Ma, L; Parkin, T B; Jaynes, D B; Fang, Q X; Hatfield, J L; Feyereisen, G W; Kersebaum, K C

    2018-03-15

    Anthropogenic perturbation of the global nitrogen cycle and its effects on the environment such as hypoxia in coastal regions and increased N 2 O emissions is of increasing, multi-disciplinary, worldwide concern, and agricultural production is a major contributor. Only limited studies, however, have simultaneously investigated NO 3 - losses to subsurface drain flow and N 2 O emissions under corn-soybean production. We used the Root Zone Water Quality Model (RZWQM) to evaluate NO 3 - losses to drain flow and N 2 O emissions in a corn-soybean system with a winter rye cover crop (CC) in central Iowa over a nine year period. The observed and simulated average drain flow N concentration reductions from CC were 60% and 54% compared to the no cover crop system (NCC). Average annual April through October cumulative observed and simulated N 2 O emissions (2004-2010) were 6.7 and 6.0kgN 2 O-Nha -1 yr -1 for NCC, and 6.2 and 7.2kgNha -1 for CC. In contrast to previous research, monthly N 2 O emissions were generally greatest when N loss to leaching were greatest, mostly because relatively high rainfall occurred during the months fertilizer was applied. N 2 O emission factors of 0.032 and 0.041 were estimated for NCC and CC using the tested model, which are similar to field results in the region. A local sensitivity analysis suggests that lower soil field capacity affects RZWQM simulations, which includes increased drain flow nitrate concentrations, increased N mineralization, and reduced soil water content. The results suggest that 1) RZWQM is a promising tool to estimate N 2 O emissions from subsurface drained corn-soybean rotations and to estimate the relative effects of a winter rye cover crop over a nine year period on nitrate loss to drain flow and 2) soil field capacity is an important parameter to model N mineralization and N loss to drain flow. Published by Elsevier B.V.

  14. Development of Charge Drain Coatings: Final CRADA Report

    Energy Technology Data Exchange (ETDEWEB)

    Elam, Jeffrey W. [Argonne National Lab. (ANL), Argonne, IL (United States)

    2017-01-17

    The primary goal of this CRADA project was to develop and optimize tunable resistive coatings prepared by atomic layer deposition (ALD) for use as charge-drain coatings on the KLA-Tencor digital pattern generators (DPGs).

  15. Peat accumulation in drained thermokarst lake basins in continuous, ice-rich permafrost, northern Seward Peninsula, Alaska

    Science.gov (United States)

    Jones, Miriam C.; Grosse, Guido; Jones, Benjamin M.; Anthony, Katey Walter

    2012-01-01

    Thermokarst lakes and peat-accumulating drained lake basins cover a substantial portion of Arctic lowland landscapes, yet the role of thermokarst lake drainage and ensuing peat formation in landscape-scale carbon (C) budgets remains understudied. Here we use measurements of terrestrial peat thickness, bulk density, organic matter content, and basal radiocarbon age from permafrost cores, soil pits, and exposures in vegetated, drained lake basins to characterize regional lake drainage chronology, C accumulation rates, and the role of thermokarst-lake cycling in carbon dynamics throughout the Holocene on the northern Seward Peninsula, Alaska. Most detectable lake drainage events occurred within the last 4,000 years with the highest drainage frequency during the medieval climate anomaly. Peat accumulation rates were highest in young (50–500 years) drained lake basins (35.2 g C m−2 yr−1) and decreased exponentially with time since drainage to 9 g C m−2 yr−1 in the oldest basins. Spatial analyses of terrestrial peat depth, basal peat radiocarbon ages, basin geomorphology, and satellite-derived land surface properties (Normalized Difference Vegetation Index (NDVI); Minimum Noise Fraction (MNF)) from Landsat satellite data revealed significant relationships between peat thickness and mean basin NDVI or MNF. By upscaling observed relationships, we infer that drained thermokarst lake basins, covering 391 km2 (76%) of the 515 km2 study region, store 6.4–6.6 Tg organic C in drained lake basin terrestrial peat. Peat accumulation in drained lake basins likely serves to offset greenhouse gas release from thermokarst-impacted landscapes and should be incorporated in landscape-scale C budgets.

  16. Drain Back Systems in Laboratory and in Practice

    DEFF Research Database (Denmark)

    Perers, Bengt; Furbo, Simon; Fan, Jianhua

    2015-01-01

    in the collector loop to have a safe reliable operation. The components should also be designed and marked so that only one correct mounting option is possible, like forward and return pipes to/from the collector of slightly different sizes or color. Adapted installer education and training is a very important...... step to have success with drain back systems. Practices used in glycol systems may give serious failures. Key-words: Drain Back, Low Flow, Solar Combi System, ETC collectors....

  17. Cold Vacuum Drying facility effluent drain system design description

    International Nuclear Information System (INIS)

    PITKOFF, C.C.

    1999-01-01

    This document describes the Cold Vacuum Drying Facility (CVDF) effluent drain system (EFS). The primary function of the EFS is to collect and transport fire suppression water discharged into a CVDF process bay to a retention basin located outside the facility. The EFS also provides confinement of spills that occur inside a process bay and allows non-contaminated water that drains to the process bay sumps to be collected until sampling and analysis are complete

  18. Steam generator fitted with a dynamic draining device

    International Nuclear Information System (INIS)

    Chaix, J.E.

    1982-01-01

    This generator has, at its upper part, at least one drying structure for holding the water carried with the steam and communicating at its lower part with at least one discharge pipe for draining off the water, each pipe communicating with a dynamic draining device capable of creating a depression in order to suck up the water contained in the drying structure. Application is for pressurized water nuclear reactors [fr

  19. Nutrient Concentrations and Stable Isotopes of Runoff from a Midwest Tile-Drained Corn Field

    Science.gov (United States)

    Wilkins, B. P.; Woo, D.; Li, J.; Michalski, G. M.; Kumar, P.; Conroy, J. L.; Keefer, D. A.; Keefer, L. L.; Hodson, T. O.

    2017-12-01

    Tile drains are a common crop drainage device used in Midwest agroecosystems. While efficient at drainage, the tiles provide a quick path for nutrient runoff, reducing the time available for microbes to use nutrients (e.g., NO3- and PO43-) and reduce export to riverine systems. Thus, understanding the effects of tile drains on nutrient runoff is critical to achieve nutrient reduction goals. Here we present isotopic and concentration data collected from tile drain runoff of a corn field located near Monticello, IL. Tile flow samples were measured for anion concentrations and stable isotopes of H2O and NO3-, while precipitation was measured for dual isotopes of H2O. Results demonstrate early tile flow from rain events have a low Cl- concentration (60% contribution) in the beginning of the hydrograph. As flow continues H2O isotopic values reflect pre-event water (ground and soil water), and Cl- concentrations increase representing a greater influence by matrix flow (60-90% contribution). Nitrate concentrations change dramatically, especially during the growing season, and do not follow a similar trend as the conservative Cl-, often decreasing days before, which represents missing nitrate in the upper surface portion of the soil. Nitrate isotopic data shows significant changes in 15N (4‰) and 18O (4‰) during individual hydrological events, representing that in addition to plant uptake and leaching, considerate NO3- is lost through denitrification. It is notable, that throughout the season d15N and d18O of nitrate change significantly representing that seasonally, substantial denitrification occurs.

  20. Environmental impacts of alternative agricultural uses of poorly drained farm land in Ireland.

    Science.gov (United States)

    Sharma, Pooja; Humphreys, James; Holden, Nicholas M

    2018-05-07

    Abolition of the milk quota in the European Union and favourable market conditions have stimulated the expansion of the dairy sector in Ireland, causing more milk to be produced from poorly drained land. This work evaluated the environmental impacts of alternative agricultural uses for poorly drained farm land in Ireland using life cycle assessment (LCA). The avoided burden of the displaced product was used to calculate the net environmental consequences in the context of regional or global markets. The impact categories evaluated were climate change, eutrophication and acidification, all expressed per hectare of land for the alternative land uses, which were pasture-based milk, suckler beef and lowland sheep production and coniferous forestry. Beef had the lowest net climate change impact with global marginal and average product substitution while sheep had the lowest net climate change impact with European displaced product. For net eutrophication and acidification, dairy had the lowest impacts with European and global average displaced product. With global marginal displaced product, forestry had the lowest net eutrophication impact and sheep had the lowest net acidification impact. From an Irish perspective, forestry would generate the lowest environmental impacts and would also increase soil carbon stock, but this was not the best land use option from global perspective. Overall it can be concluded that a pasture based dairy or sheep system would have the greatest net global impact reduction (i.e. greatest global benefit) as land use options for farms with poorly drained soils. Prioritizing climate change, suckler beef system would perhaps be more favourable. It is clear that the choice of the displaced regional or global co-product from the market has a great influence on the results and there is a need to consider more detailed consumption modelling to better understand the substitution process. Copyright © 2018 Elsevier B.V. All rights reserved.

  1. Investigation on the Effect of Drained Strength when Designing Sheet Pile Walls

    DEFF Research Database (Denmark)

    Iversen, Kirsten Malte; Nielsen, Benjaminn Nordahl; Augustesen, Anders Hust

    that the height, anchor force, and the maximum bending moment in the wall can be lowered significantly when the effective cohesion is increased above zero. However, as the cohesion increases, the drop in the moment levels off, which implies that the benefit obtained from investigations increasing the cohesion......Long sheet pile walls are constructed in the cities as an integrated part of deep excavations for e.g. parking lots, pumping stations, reservoirs, and cut and cover tunnels. To minimise costs, the strength of the soil needs to be determined in the best possible way. The drained strength of clay...... expressed by c and ϕ is often estimated as c 10% = 10%・cu, and found by estimations based on the soil describtion, respectively. However, due to possible slicken slides and tension cracks, c = 0 is used on the back side of the sheet pile wall. This reduces the strength significantly. A parametric study...

  2. Circuital model for the spherical geodesic waveguide perfect drain

    Science.gov (United States)

    González, Juan C.; Grabovičkić, Dejan; Benítez, Pablo; Miñano, Juan C.

    2012-08-01

    The perfect drain for the Maxwell fish eye (MFE) is a non-magnetic dissipative region placed in the focal point to absorb all the incident radiation without reflection or scattering. The perfect drain was recently designed as a material with complex permittivity that depends on frequency. However, this material is only a theoretical material, so it cannot be used in practical devices. The perfect drain has been claimed as necessary for achieving super-resolution (Leonhardt 2009 New J. Phys. 11 093040), which has increased the interest in practical perfect drains suitable for manufacturing. Here, we present a practical perfect drain that is designed using a simple circuit (made of a resistance and a capacitor) connected to the coaxial line. Moreover, we analyze the super-resolution properties of a device equivalent to the MFE, known as a spherical geodesic waveguide, loaded with this perfect drain. The super-resolution analysis for this device is carried out using COMSOL Multiphysics. The results of simulations predict a super-resolution of up to λ/3000.

  3. Circuital model for the spherical geodesic waveguide perfect drain

    International Nuclear Information System (INIS)

    González, Juan C; Grabovičkić, Dejan; Benítez, Pablo; Miñano, Juan C

    2012-01-01

    The perfect drain for the Maxwell fish eye (MFE) is a non-magnetic dissipative region placed in the focal point to absorb all the incident radiation without reflection or scattering. The perfect drain was recently designed as a material with complex permittivity that depends on frequency. However, this material is only a theoretical material, so it cannot be used in practical devices. The perfect drain has been claimed as necessary for achieving super-resolution (Leonhardt 2009 New J. Phys. 11 093040), which has increased the interest in practical perfect drains suitable for manufacturing. Here, we present a practical perfect drain that is designed using a simple circuit (made of a resistance and a capacitor) connected to the coaxial line. Moreover, we analyze the super-resolution properties of a device equivalent to the MFE, known as a spherical geodesic waveguide, loaded with this perfect drain. The super-resolution analysis for this device is carried out using COMSOL Multiphysics. The results of simulations predict a super-resolution of up to λ/3000. (paper)

  4. Calibration and Validation of the Precision Nitrogen Management Tool for Artificially Drained Fields Under Maize

    Science.gov (United States)

    Marjerison, R.; Hutson, J.; Melkonian, J.; van Es, H.; Sela, S.

    2015-12-01

    Organic and inorganic fertilizer additions to agricultural fields can lead to soil nitrogen (N) levels in excess of those required for optimal crop growth. The primary loss pathways for this excess N are leaching and denitrification. Nitrate leaching from agricultural sources contributes to the formation of hypoxic zones in critical estuarine systems including the Chesapeake Bay and Gulf of Mexico. Denitrification can lead to the production of nitrous oxide (N2O), a potent greenhouse gas. Agricultural practices such as controlling the timing and location of fertilizer application can help reduce these losses. The Precision Nitrogen Management (PNM) model was developed to simulate water transport, nitrogen transformations and transport, and crop growth and nutrient uptake from agricultural fields. The PNM model allows for the prediction of N losses under a variety of crop and management scenarios. Recent improvements to the model include the option to simulate artificially drained fields. The model performs well in simulating drainage and nitrate leaching when compared to measured data from field studies in artificially drained soils in New York and Minnesota. A simulated N budget was compared to available data. The improved model will be used to assess different management options for reducing N losses in maize production under different climate projections for key maize production locations/systems in the U.S.

  5. Brain drain from developing countries: how can brain drain be converted into wisdom gain?

    Science.gov (United States)

    Dodani, Sunita; LaPorte, Ronald E

    2005-01-01

    Brain drain is defined as the migration of health personnel in search of the better standard of living and quality of life, higher salaries, access to advanced technology and more stable political conditions in different places worldwide. This migration of health professionals for better opportunities, both within countries and across international borders, is of growing concern worldwide because of its impact on health systems in developing countries. Why do talented people leave their countries and go abroad? What are the consequences of such migrations especially on the educational sector? What policies can be adopted to stem such movements from developing countries to developed countries? This article seeks to raise questions, identify key issues and provide solutions which would enable immigrant health professionals to share their knowledge, skills and innovative capacities and thereby enhancing the economic development of their countries. PMID:16260795

  6. Remaining Sites Verification Package for the 100-D-50:5 Process Sewers (183-DR Sedimentation Basin Drains). Attachment to Waste Site Reclassification Form 2006-025

    International Nuclear Information System (INIS)

    Dittmer, L.M.

    2007-01-01

    The 100-D-50:5 subsite encompasses the southern process sewers formerly servicing the 183-DR coagulation and sedimentation basins and proximate surface runoff collection drains. The results of confirmatory sampling of pipeline sediments and underlying soils at the 100-D-50:5 subsite demonstrated that residual contaminant concentrations do not preclude any future uses and allow for unrestricted use of shallow zone soils. The results also showed that residual contaminant concentrations are protective of groundwater and the Columbia River

  7. Study of the patency of different peritoneal drains used prophylactically in bariatric surgery.

    Science.gov (United States)

    Salgado Júnior, Wilson; Macedo Neto, Marcelo Martins; dos Santos, José Sebastião; Sakarankutty, Ajith Kumar; Ceneviva, Reginaldo; de Castro e Silva, Orlando

    2009-05-21

    To compare the performance of different types of abdominal drains used in bariatric surgery. A vertical banded Roux-en-Y gastric bypass was performed in 33 morbidly obese patients. Drainage of the peritoneal cavity was performed in each case using three different types of drain selected in a randomized manner: a latex tubular drain, a Watterman tubulolaminar drain, and a silicone channeled drain. Drain permeability, contamination of the drained fluid, ease of handling, and patient discomfort were evaluated postoperatively over a period of 7 d. The patients with the silicone channeled drain had larger volumes of drainage compared to patients with tubular and tubulolaminar drains between the third and seventh postoperative days. In addition, a lower incidence of discomfort and of contamination with bacteria of a more pathogenic profile was observed in the patients with the silicone channeled drain. The silicone channeled drain was more comfortable and had less chance of occlusion, which is important in the detection of delayed dehiscence.

  8. PEAT-CO2. Assessment of CO2 emissions from drained peatlands in SE Asia

    International Nuclear Information System (INIS)

    Hooijer, A.; Silvius, M.; Woesten, H.; Page, S.

    2006-12-01

    Forested tropical peatlands in SE Asia store at least 42,000 Megatonnes of soil carbon. This carbon is increasingly released to the atmosphere due to drainage and fires associated with plantation development and logging. Peatlands make up 12% of the SE Asian land area but account for 25% of current deforestation. Out of 27 million hectares of peatland, 12 million hectares (45%) are currently deforested and mostly drained. One important crop in drained peatlands is palm oil, which is increasingly used as a biofuel in Europe. In the PEAT-CO2 project, present and future emissions from drained peatlands were quantified using the latest data on peat extent and depth, present and projected land use and water management practice, decomposition rates and fire emissions. It was found that current likely CO2 emissions caused by decomposition of drained peatlands amounts to 632 Mt/y (between 355 and 874 Mt/y). This emission will increase in coming decades unless land management practices and peatland development plans are changed, and will continue well beyond the 21st century. In addition, over 1997-2006 an estimated average of 1400 Mt/y in CO2 emissions was caused by peatland fires that are also associated with drainage and degradation. The current total peatland CO2 emission of 2000 Mt/y equals almost 8% of global emissions from fossil fuel burning. These emissions have been rapidly increasing since 1985 and will further increase unless action is taken. Over 90% of this emission originates from Indonesia, which puts the country in 3rd place (after the USA and China) in the global CO2 emission ranking. It is concluded that deforested and drained peatlands in SE Asia are a globally significant source of CO2 emissions and a major obstacle to meeting the aim of stabilizing greenhouse gas emissions, as expressed by the international community. It is therefore recommended that international action is taken to help SE Asian countries, especially Indonesia, to better conserve

  9. Nurses’ Knowledge Levels of Chest Drain Management: A Descriptive Study

    Directory of Open Access Journals (Sweden)

    Merve Tarhan

    2016-12-01

    Full Text Available Objective: The physician is responsible for inserting one or more chest tubes into the pleural space or the mediastinal space and connecting them to an appropriate drainage system. When the general principles about care of patients with chest drains were implemented correctly and effectively by nurses, nurse will contribute to accelerate the healing process of patients. In this context, the aim of this study was to determine the nurses’ level of knowledge regarding the care of patients with chest drains. Methods: The study was conducted with 153 nurses who worked in a chest diseases and thoracic surgery hospital in July 2014. Questionnaire form of 35 questions prepared by investigators was used to collect data. For the analysis of results, frequency tests, independent sample t-test and oneway ANOVA test were used. Results: 69.3% of nurses stated that they had obtained information from colleguages. 35.3% considered their knowledge about chest drain management to be inadequate. 55.6% scored 13 points and above from knowledge questionnaire about chest drain management. There were statistically significant difference between knowledge level and educational background, clinic work type, working unit, years of professional experience and institutional experience, frequency of contact patients with chest drain and perception of knowledge level (p<0.05. Conclusion: Results of this study indicate that lack of evidence-based nursing care and insufficient training has resulted in uncertainty and knowledge deficit in important aspects of chest drain care. It can be concluded that nurses receive training needs and training protocols are about chest drain management.

  10. Prediction of phosphorus loads in an artificially drained lowland catchment using a modified SWAT model

    Science.gov (United States)

    Bauwe, Andreas; Eckhardt, Kai-Uwe; Lennartz, Bernd

    2017-04-01

    Eutrophication is still one of the main environmental problems in the Baltic Sea. Currently, agricultural diffuse sources constitute the major portion of phosphorus (P) fluxes to the Baltic Sea and have to be reduced to achieve the HELCOM targets and improve the ecological status. Eco-hydrological models are suitable tools to identify sources of nutrients and possible measures aiming at reducing nutrient loads into surface waters. In this study, the Soil and Water Assessment Tool (SWAT) was applied to the Warnow river basin (3300 km2), the second largest watershed in Germany discharging into the Baltic Sea. The Warnow river basin is located in northeastern Germany and characterized by lowlands with a high proportion of artificially drained areas. The aim of this study were (i) to estimate P loadings for individual flow fractions (point sources, surface runoff, tile flow, groundwater flow), spatially distributed on sub-basin scale. Since the official version of SWAT does not allow for the modeling of P in tile drains, we tested (ii) two different approaches of simulating P in tile drains by changing the SWAT source code. The SWAT source code was modified so that (i) the soluble P concentration of the groundwater was transferred to the tile water and (ii) the soluble P in the soil was transferred to the tiles. The SWAT model was first calibrated (2002-2011) and validated (1992-2001) for stream flow at 7 headwater catchments at a daily time scale. Based on this, the stream flow at the outlet of the Warnow river basin was simulated. Performance statistics indicated at least satisfactory model results for each sub-basin. Breaking down the discharge into flow constituents, it becomes visible that stream flow is mainly governed by groundwater and tile flow. Due to the topographic situation with gentle slopes, surface runoff played only a minor role. Results further indicate that the prediction of soluble P loads was improved by the modified SWAT versions. Major sources of

  11. Test of a simplified modeling approach for nitrogen transfer in agricultural subsurface-drained catchments

    Science.gov (United States)

    Henine, Hocine; Julien, Tournebize; Jaan, Pärn; Ülo, Mander

    2017-04-01

    In agricultural areas, nitrogen (N) pollution load to surface waters depends on land use, agricultural practices, harvested N output, as well as the hydrology and climate of the catchment. Most of N transfer models need to use large complex data sets, which are generally difficult to collect at larger scale (>km2). The main objective of this study is to carry out a hydrological and a geochemistry modeling by using a simplified data set (land use/crop, fertilizer input, N losses from plots). The modelling approach was tested in the subsurface-drained Orgeval catchment (Paris Basin, France) based on following assumptions: Subsurface tile drains are considered as a giant lysimeter system. N concentration in drain outlets is representative for agricultural practices upstream. Analysis of observed N load (90% of total N) shows 62% of export during the winter. We considered prewinter nitrate (NO3) pool (PWNP) in soils at the beginning of hydrological drainage season as a driving factor for N losses. PWNP results from the part of NO3 not used by crops or the mineralization part of organic matter during the preceding summer and autumn. Considering these assumptions, we used PWNP as simplified input data for the modelling of N transport. Thus, NO3 losses are mainly influenced by the denitrification capacity of soils and stream water. The well-known HYPE model was used to perform water and N losses modelling. The hydrological simulation was calibrated with the observation data at different sub-catchments. We performed a hydrograph separation validated on the thermal and isotopic tracer studies and the general knowledge of the behavior of Orgeval catchment. Our results show a good correlation between the model and the observations (a Nash-Sutcliffe coefficient of 0.75 for water discharge and 0.7 for N flux). Likewise, comparison of calibrated PWNP values with the results from a field survey (annual PWNP campaign) showed significant positive correlation. One can conclude that

  12. Current practice patterns of drain usage amongst UK and Irish surgeons performing bilateral breast reductions: Evidence down the drain.

    Science.gov (United States)

    Sugrue, Conor M; McInerney, Niall; Joyce, Cormac W; Jones, Deidre; Hussey, Alan J; Kelly, Jack L; Kerin, Michael J; Regan, Padraic J

    2015-01-01

    Bilateral breast reduction (BBR) is one of the most frequently performed female breast operations. Despite no evidence supporting efficacy of drain usage in BBRs, postoperative insertion is common. Recent high quality evidence demonstrating potential harm from drain use has subsequently challenged this traditional practice. The aim of this study is to assess the current practice patterns of drains usage by Plastic & Reconstructive and Breast Surgeons in UK and Ireland performing BBRs. An 18 question survey was created evaluating various aspects of BBR practice. UK and Irish Plastic & Reconstructive and Breast Surgeons were invited to participate by an email containing a link to a web-based survey. Statistical analysis was performed with student t-test and chi-square test. Two hundred and eleven responding surgeons were analysed, including 80.1% (171/211) Plastic Surgeons and 18.9% (40/211) Breast Surgeons. Of the responding surgeons, 71.6% (151/211) routinely inserted postoperative drains, for a mean of 1.32 days. Drains were used significantly less by surgeons performing ≥20 BBRs (p = 0.02). With the majority of BBRs performed as an inpatient procedure, there was a trend towards less drain usage in surgeons performing this procedure as an outpatient; however, this was not statistically significant (p = 0.07). Even with the high level of evidence demonstrating the safety of BBR without drains, they are still routinely utilised. In an era of evidence- based medicine, surgeons performing breast reductions must adopt the results from scientific research into their clinical practice.

  13. Corn stover harvest increases herbicide movement to subsurface drains: RZWQM simulations

    Science.gov (United States)

    Shipitalo, Martin J.; Malone, Robert W.; Ma, Liwang; Nolan, Bernard T.; Kanwar, Rameshwar S.; Shaner, Dale L.; Pederson, Carl H.

    2016-01-01

    BACKGROUND Crop residue removal for bioenergy production can alter soil hydrologic properties and the movement of agrochemicals to subsurface drains. The Root Zone Water Quality Model (RZWQM), previously calibrated using measured flow and atrazine concentrations in drainage from a 0.4 ha chisel-tilled plot, was used to investigate effects of 50 and 100% corn (Zea mays L.) stover harvest and the accompanying reductions in soil crust hydraulic conductivity and total macroporosity on transport of atrazine, metolachlor, and metolachlor oxanilic acid (OXA). RESULTS The model accurately simulated field-measured metolachlor transport in drainage. A 3-yr simulation indicated that 50% residue removal decreased subsurface drainage by 31% and increased atrazine and metolachlor transport in drainage 4 to 5-fold when surface crust conductivity and macroporosity were reduced by 25%. Based on its measured sorption coefficient, ~ 2-fold reductions in OXA losses were simulated with residue removal. CONCLUSION RZWQM indicated that if corn stover harvest reduces crust conductivity and soil macroporosity, losses of atrazine and metolachlor in subsurface drainage will increase due to reduced sorption related to more water moving through fewer macropores. Losses of the metolachlor degradation product OXA will decrease due to the more rapid movement of the parent compound into the soil.

  14. A study of the complications of small bore 'Seldinger' intercostal chest drains.

    Science.gov (United States)

    Davies, Helen E; Merchant, Shairoz; McGown, Anne

    2008-06-01

    Use of small bore chest drains (drainage over a 12-month period. One hundred consecutive small bore Seldinger (12F) chest drain insertions were evaluated. Few serious complications occurred. However, 21% of the chest drains were displaced ('fell out') and 9% of the drains became blocked. This contributed to high morbidity rates, with 13% of patients requiring repeat pleural procedures. The frequency of drain blockage in pleural effusion was reduced by administration of regular normal saline drain flushes (odds ratio for blockage in flushed drains compared with non-flushed drains 0.04, 95% CI: 0.01-0.37, P < 0.001). Regular chest drain flushes are advocated in order to reduce rates of drain blockage, and further studies are needed to determine optimal fixation strategies that may reduce associated patient morbidity.

  15. Frequency dependence and passive drains in fish-eye lenses

    Science.gov (United States)

    Quevedo-Teruel, O.; Mitchell-Thomas, R. C.; Hao, Y.

    2012-11-01

    The Maxwell fish eye lens has previously been reported as being capable of the much sought after phenomenon of subwavelength imaging. The inclusion of a drain in this system is considered crucial to the imaging ability, although its role is the topic of much debate. This paper provides a numerical investigation into a practical implementation of a drain in such systems, and analyzes the strong frequency dependence of both the Maxwell fish eye lens and an alternative, the Miñano lens. The imaging capability of these types of lens is questioned, and it is supported by simulations involving various configurations of drain arrays. Finally, a discussion of the near-field and evanescent wave contribution is given.

  16. Fibredrain method. Environmentally friendly vertical drain; Fiberdrain koho. Kankyo ni yasashii vertical drain koho

    Energy Technology Data Exchange (ETDEWEB)

    Suto, Y.; Inoue, T. [Fukken Co. Ltd., Hiroshima (Japan); Miura, N. [Saga University, Saga (Japan). Faculty of Science and Engineering; Yoshida, Y.; Hamada, K. [Hiroshima Prefectural Government Office, Hiroshima (Japan); Aboshi, H. [Hiroshima University, Hiroshima (Japan)

    1997-11-01

    Ground improvement using fibredrain (FD) material has not been used in Japan. For its practical use in Japan, laboratory experiment was made on such technological characteristics of FD material as tensile strength and permeability, and field test was also made to verify its improvement effect. A plane FD specimen of nearly 90mm wide and 9mm thick is composed of a folded double jute fabrics band and 4 twisted coir ropes arranged between the jute fabrics at even intervals, and the band is sewn up along center lines between the ropes. A mean permeability coefficient is estimated to be {kappa} = 1.0times10{sup -1}cm/s and {kappa} = 1.0times10{sup -2}cm/s at {sigma}{sup 3} = 0.5kgf/cm{sup 2} and {sigma}{sup 3} = 2.0kgf/cm{sup 2} in lateral pressure, respectively, showing sufficient permeabilities for vertical drain material. The tensile strength of fresh FD material is estimated to be a little stronger than 900kg/material width which is far stronger than that of conventional FD materials. The field test result showed that the FD material achieved the target for ground improvement, and has sufficient functions as a substitute for SD material. 6 refs., 10 figs.

  17. Moist Soil Management of Wetland Impoundments for Plants and Invertebrates

    Data.gov (United States)

    Department of the Interior — In year’s past an impoundment was drained (a drawdown) when floating-leaved plants covered more than 50% of the water area. Drawdowns encourage beneficial moist soil...

  18. Subsoil erosion dominates the supply of fine sediment to rivers draining into Princess Charlotte Bay, Australia.

    Science.gov (United States)

    Olley, Jon; Brooks, Andrew; Spencer, John; Pietsch, Timothy; Borombovits, Daniel

    2013-10-01

    The Laura-Normanby River (catchment area: 24,350 km(2)), which drains into Princess Charlotte Bay, has been identified in previous studies as the third largest contributor of sediment to the Great Barrier Reef World Heritage Area. These catchment scale modelling studies also identified surface soil erosion as supplying >80% of the sediment. Here we use activity concentrations of the fallout radionuclides (137)Cs and (210)Pbex to test the hypothesis that surface soil erosion dominates the supply of fine (river systems draining into Princess Charlotte Bay. Our results contradict these previous studies, and are consistent with channel and gully erosion being the dominant source of fine sediment in this catchment. The hypothesis that surface soil erosion dominates the supply of fine sediment to Princess Charlotte Bay is rejected. River sediment samples were collected using both time-integrated samplers and sediment drape deposits. We show that there is no detectable difference in (137)Cs and (210)Pbex activity concentrations between samples collected using these two methods. Two methods were also used to collect samples to characterise (137)Cs and (210)Pbex concentrations in sediment derived from surface soil erosion; sampling of surface-wash deposits and deployment of surface runoff traps that collected samples during rain events. While there was no difference in the (137)Cs activity concentrations for samples collected using these two methods, (210)Pbex activity concentrations were significantly higher in the samples collected using the runoff traps. The higher (210)Pbex concentrations are shown to be correlated with loss-on-ignition (r(2) = 0.79) and therefore are likely to be related to higher organic concentrations in the runoff trap samples. As a result of these differences we use a three end member mixing model (channel/gully, hillslope surface-wash and hillslope runoff traps) to determine the relative contribution from surface soil erosion. Probability

  19. Replacement of the drain system of secondary circuit at Monju

    International Nuclear Information System (INIS)

    Itoh, Kenji; Onuki, Koji; Tomobe, Katsuma; Taniyama, Sadami

    2003-01-01

    Monju is as a Japan's prototype fast breeder reactor cooled by liquid sodium. In the course of power buildup tests, the sodium leakage accident broke out on 8th December 1995. Though Monju has been already equipped with countermeasure systems against the sodium leakage accident, some additional improvements will be taken in order to reduce the damage by the leaked sodium when another leakage accident should recur. The most characteristic work is the drain system modification that leads to shorten the drain time and to reduce the quantity of leaked sodium in the event of sodium leakage. (author)

  20. Optimization design for drain to nuclear power condenser

    International Nuclear Information System (INIS)

    Ding Jiapeng; Jiang Chengren

    2010-01-01

    Characters and varieties of drain to nuclear power condenser are discussed in this paper. Take the main steam system of a nuclear power as an example, normal and detailed optimization design are introduced, related expatiate are used as a reference for the drain of other systems. According to the characters of nuclear power instant operation, the influence and needed actions related with the optimization design are also analyzed. Based on the above research, the scheme has been carried out in a nuclear power station and safety for the condenser operation of the nuclear power has been improved largely. (authors)

  1. Rare bile duct anomaly: B3 duct draining to gallbladder

    Directory of Open Access Journals (Sweden)

    Seung Eun Lee

    2016-01-01

    Full Text Available A 10-year-old girl presented with recurrent right upper abdominal pain and dyspepsia. Magnetic resonance cholangiopancreatography revealed a dilated common channel of intrahepatic bile duct of segment 3 (B3 and segment 4 (B4 drained into the gallbladder directly. The patient underwent laparoscopic cholecystectomy and Roux-en Y hepaticojejunostomy (B3-jejunostomy. Among the anatomical variability of the biliary system, the cholecystohepatic ducts are controversial in existence and incidence. We report a very rare variant of a cholecystohepatic duct in which the B3 duct drained into gallbladder directly and to the best of our knowledge this is the first report.

  2. Nitrate concentration-drainage flow (C-Q) relationship for a drained agricultural field in Eastern North Carolina Plain

    Science.gov (United States)

    Liu, W.; Youssef, M.; Birgand, F.; Chescheir, G. M.; Maxwell, B.; Tian, S.

    2017-12-01

    Agricultural drainage is a practice used to artificially enhance drainage characteristics of naturally poorly drained soils via subsurface drain tubing or open-ditch systems. Approximately 25% of the U.S. agricultural land requires improved drainage for economic crop production. However, drainage increases the transport of dissolved agricultural chemicals, particularly nitrates to downstream surface waters. Nutrient export from artificially drained agricultural landscapes has been identified as the leading source of elevated nutrient levels in major surface water bodies in the U.S. Controlled drainage has long been practiced to reduce nitrogen export from agricultural fields to downstream receiving waters. It has been hypothesized that controlled drainage reduces nitrogen losses by promoting denitrification, reducing drainage outflow from the field, and increasing plant uptake. The documented performance of the practice was widely variable as it depends on several site-specific factors. The goal of this research was to utilize high frequency measurements to investigate the effect of agricultural drainage and related management practices on nitrate fate and transport for an artificially drained agricultural field in eastern North Carolina. We deployed a field spectrophotometer to measure nitrate concentration every 45 minutes and measured drainage flow rate using a V-notch weir every 15 minutes. Furthermore, we measured groundwater level, precipitation, irrigation amount, temperature to characterize antecedent conditions for each event. Nitrate concentration-drainage flow (C-Q) relationships generated from the high frequency measurements illustrated anti-clockwise hysteresis loops and nitrate flushing mechanism in response to most precipitation and irrigation events. Statistical evaluation will be carried out for the C-Q relationships. The results of our analysis, combined with numerical modeling, will provide a better understanding of hydrological and

  3. Does the suction drain diameter matter? Bleeding analysis after total knee replacement comparing different suction drain gauges

    Directory of Open Access Journals (Sweden)

    Marcos George de Souza Leao

    Full Text Available ABSTRACT OBJECTIVES: To evaluate bleeding and the estimated blood loss in patients who underwent total knee replacement (TKR with different closed suction drains (3.2-mm and 4.8-mm gauge. METHODS: This was a randomized controlled trial with 22 patients who underwent TKR and were divided into two groups: Group I, with 11 patients in whom the 3.2-mm suction drain was used, and Group II, with 11 patients in whom the 4.8-mm suction drain was used. The hematocrit was measured after 24, 48 and 72 h after surgery in order to calculate the estimated blood loss. The drained volume was measured 3, 6, 12, 24, and 48 h after TKR, and thereafter both groups were compared. RESULTS: Regarding the hematocrit, there were no differences between groups in measured periods (24, 48, and 72 h after surgery. The total bleeding measured at the suction drains within 48 h was higher in Group II, with a statistically significant difference (p = 0.005; in the first 24 h, there was major bleeding in Group II (mean 893 mL, with a significant difference (p = 0.004. Between 24 and 48 h, there was no statistically significant difference in both groups (p = 0.710. The total estimated bleeding was higher in Group I, with mean of 463 mL, versus 409 mL in Group II, with no statistical significance (p = 0.394. CONCLUSIONS: Bleeding was higher in the group that used the 4.8 mm gauge suction drain, with no differences in hematocrit and estimated blood loss.

  4. Verifiable metamodels for nitrate losses to drains and groundwater in the Corn Belt, USA

    Science.gov (United States)

    Nolan, Bernard T.; Malone, Robert W.; Gronberg, Jo Ann M.; Thorp, K.R.; Ma, Liwang

    2012-01-01

    Nitrate leaching in the unsaturated zone poses a risk to groundwater, whereas nitrate in tile drainage is conveyed directly to streams. We developed metamodels (MMs) consisting of artificial neural networks to simplify and upscale mechanistic fate and transport models for prediction of nitrate losses by drains and leaching in the Corn Belt, USA. The two final MMs predicted nitrate concentration and flux, respectively, in the shallow subsurface. Because each MM considered both tile drainage and leaching, they represent an integrated approach to vulnerability assessment. The MMs used readily available data comprising farm fertilizer nitrogen (N), weather data, and soil properties as inputs; therefore, they were well suited for regional extrapolation. The MMs effectively related the outputs of the underlying mechanistic model (Root Zone Water Quality Model) to the inputs (R2 = 0.986 for the nitrate concentration MM). Predicted nitrate concentration was compared with measured nitrate in 38 samples of recently recharged groundwater, yielding a Pearson’s r of 0.466 (p = 0.003). Predicted nitrate generally was higher than that measured in groundwater, possibly as a result of the time-lag for modern recharge to reach well screens, denitrification in groundwater, or interception of recharge by tile drains. In a qualitative comparison, predicted nitrate concentration also compared favorably with results from a previous regression model that predicted total N in streams.

  5. Modeling the effects of tile drain placement on the hydrologic function of farmed prairie wetlands

    Science.gov (United States)

    Werner, Brett; Tracy, John; Johnson, W. Carter; Voldseth, Richard A.; Guntenspergen, Glenn R.; Millett, Bruce

    2016-01-01

    The early 2000s saw large increases in agricultural tile drainage in the eastern Dakotas of North America. Agricultural practices that drain wetlands directly are sometimes limited by wetland protection programs. Little is known about the impacts of tile drainage beyond the delineated boundaries of wetlands in upland catchments that may be in agricultural production. A series of experiments were conducted using the well-published model WETLANDSCAPE that revealed the potential for wetlands to have significantly shortened surface water inundation periods and lower mean depths when tile is placed in certain locations beyond the wetland boundary. Under the soil conditions found in agricultural areas of South Dakota in North America, wetland hydroperiod was found to be more sensitive to the depth that drain tile is installed relative to the bottom of the wetland basin than to distance-based setbacks. Because tile drainage can change the hydrologic conditions of wetlands, even when deployed in upland catchments, tile drainage plans should be evaluated more closely for the potential impacts they might have on the ecological services that these wetlands currently provide. Future research should investigate further how drainage impacts are affected by climate variability and change.

  6. Remaining Sites Verification Package for the 100-F-46, 119-F Stack Sampling French Drain. Attachment to Waste Site Reclassification Form 2008-021

    International Nuclear Information System (INIS)

    Capron, J.M.

    2008-01-01

    The 100-F-46 french drain consisted of a 1.5 to 3 m long, vertically buried, gravel-filled pipe that was approximately 1 m in diameter. Also included in this waste site was a 5 cm cast-iron pipeline that drained condensate from the 119-F Stack Sampling Building into the 100-F-46 french drain. In accordance with this evaluation, the confirmatory sampling results support a reclassification of this site to No Action. The current site conditions achieve the remedial action objectives and the corresponding remedial action goals established in the Remaining Sites ROD. The results of confirmatory sampling show that residual contaminant concentrations do not preclude any future uses and allow for unrestricted use of shallow zone soils. The results also demonstrate that residual contaminant concentrations are protective of groundwater and the Columbia River

  7. The management of vacuum neck drains in head and neck surgery and the comparison of two different practice protocols for drain removal.

    Science.gov (United States)

    Kasbekar, A V; Davies, F; Upile, N; Ho, M W; Roland, N J

    2016-01-01

    Introduction The management of vacuum neck drains in head and neck surgery is varied. We aimed to improve early drain removal and therefore patient discharge in a safe and effective manner. Methods The postoperative management of head and neck surgical patients with vacuum neck drains was reviewed retrospectively. A new policy was then implemented to measure drainage three times daily (midnight, 6am, midday). The decision for drain removal was based on the most recent drainage period (at Measuring drainage volumes three times daily allows for more accurate assessment of wound drainage, and this can lead to earlier removal of neck drains and safe discharge.

  8. Brain drain or brain gain : The case of Suriname

    NARCIS (Netherlands)

    T.W. Dulam (Tina)

    2015-01-01

    markdownabstractAbstract Brain drain refers to the emigration of highly skilled individuals mostly from a less developed (home) to a developed country (destination) thereby reducing the capacity of the home country to generate welfare for its population. In the literature there is much written

  9. State waste discharge permit application, 200-E chemical drain field

    International Nuclear Information System (INIS)

    1994-06-01

    As part of the Hanford Federal Facility Agreement and Consent Order negotiations (Ecology et al. 1994), the US Department of Energy, Richland Operations Office, the US Environmental Protection Agency, and the Washington State Department of Ecology agreed that liquid effluent discharges to the ground on the Hanford Site which affect groundwater or have the potential to affect ground would be subject to permitting under the structure of Chapter 173-216 (or 173-218 where applicable) of the Washington Administrative Code, the State Waste Discharge Permit Program. As a result of this decision, the Washington State Department of Ecology and the US Department of Energy, Richland Operations Office entered into Consent Order No. DE 91NM-177, (Ecology and DOE-RL 1991). The Consent Order No. DE 91NM-177 requires a series of permitting activities for liquid effluent discharges. This document presents the State Waste Discharge Permit (SWDP) application for the 200-E Chemical Drain Field. Waste water from the 272-E Building enters the process sewer line directly through a floor drain, while waste water from the 2703-E Building is collected in two floor drains, (north and south) that act as sumps and are discharged periodically. The 272-E and 2703-E Buildings constitute the only discharges to the process sewer line and the 200-E Chemical Drain Field

  10. Outcome in Chronic Subdural Hematoma After Subdural vs. Subgaleal Drain.

    Science.gov (United States)

    Ishfaq, Asim

    2017-07-01

    To compare the outcome after surgery for chronic subdural hematoma when the drain is placed in subdural space or subgaleal space. Quasi experimental study. Combined Military Hospital, Lahore, from July 2015 to June 2016. Patients with chronic subdural hematoma of both genders and age, ranging between 55 to 85 years, were included. Patients on antiplatelet/anticoagulant therapy and acute on chronic subdural hematoma were excluded. Patients were divided in two equal groups each depending on whether drain was placed in subgaleal space (Group 1), and subdual space (Group 2), (n=31 patients each). Patients were positioned flat in bed after surgery. Clinical and radiological parameters and clinical outcome were compared between the two groups. Statistical test with significance of p hematoma was 15 ±6.5 mm. Patients with subdural drain placement had more complications such as pneumocephalus 11 (35.4%) vs. 6 (19.3%), and intracerebral hemorrhage 4 (12.9%) vs. 2 (6.4%). Clinical outcome was good in both groups 27 (87%) in Group 1 and 28 (90%) in Group 2. Patients of both groups had good outcome after surgery. Complications like pneumocephalus and intracerebral hemorrhage were more common in subdural location of drain, though not reaching statistically significance level to favor one technique over another.

  11. On the use of drains in orthopedic and trauma

    African Journals Online (AJOL)

    2013-11-08

    Nov 8, 2013 ... Even major procedures like total knee and arthroplasties are being performed without drains. We set to find ... discourage wound healing while encouraging bacterial ... a period of two days or if drainage over the first twenty‑four hours was found ... Three of the twenty Kuntscher nailings for femoral fracture.

  12. Brain Drain: A Child's Brain on Poverty. Poverty Fact Sheet

    Science.gov (United States)

    Damron, Neil

    2015-01-01

    "Brain Drain: A Child's Brain on Poverty," released in March 2015 and prepared by intern Neil Damron, explores the brain's basic anatomy and recent research findings suggesting that poverty affects the brain development of infants and young children and the potential lifelong effects of the changes. The sheet draws from a variety of…

  13. State waste discharge permit application, 200-E chemical drain field

    Energy Technology Data Exchange (ETDEWEB)

    1994-06-01

    As part of the Hanford Federal Facility Agreement and Consent Order negotiations (Ecology et al. 1994), the US Department of Energy, Richland Operations Office, the US Environmental Protection Agency, and the Washington State Department of Ecology agreed that liquid effluent discharges to the ground on the Hanford Site which affect groundwater or have the potential to affect ground would be subject to permitting under the structure of Chapter 173-216 (or 173-218 where applicable) of the Washington Administrative Code, the State Waste Discharge Permit Program. As a result of this decision, the Washington State Department of Ecology and the US Department of Energy, Richland Operations Office entered into Consent Order No. DE 91NM-177, (Ecology and DOE-RL 1991). The Consent Order No. DE 91NM-177 requires a series of permitting activities for liquid effluent discharges. This document presents the State Waste Discharge Permit (SWDP) application for the 200-E Chemical Drain Field. Waste water from the 272-E Building enters the process sewer line directly through a floor drain, while waste water from the 2703-E Building is collected in two floor drains, (north and south) that act as sumps and are discharged periodically. The 272-E and 2703-E Buildings constitute the only discharges to the process sewer line and the 200-E Chemical Drain Field.

  14. Moving Policy Forward: "Brain Drain" as a Wicked Problem

    Science.gov (United States)

    Logue, Danielle

    2009-01-01

    The mobility of scientists and the concerns surrounding "brain drain" are not new. Even in the Ptolemic dynasty, the first king set out to attract and influence the movements of scholars to shift the centre of learning from Athens to Alexandria. Yet after all this time, there is still much policy discourse and debate focused on attempting to…

  15. Xpand chest drain: assessing equivalence to current standard ...

    African Journals Online (AJOL)

    leakage from 'open to air' system or breakage of glass bottle (with associated risk to ... and an air-leak detection system. It is connected to a ... need to add water. Xpand chest drain: assessing equivalence to current standard therapy – a randomised controlled trial. CHARL COOPER, M.B. CH.B. TIMOTHY HARDCASTLE ...

  16. An Improvised Active Drain | Ogirima | Nigerian Journal of Surgical ...

    African Journals Online (AJOL)

    An improvised active drain is designed from intravenous infusion set and recycled RedivacR or Haemovac® bottle. Outcome of the use of this system on 100 patients is presented. This suction drainage system had been used in major orthopaedic and common minor surgical procedures and no significant complication was ...

  17. Case Report: Supernumerary right renal vein draining inferior to the ...

    African Journals Online (AJOL)

    With recent increase in renal transplantations, renovascular reconstructions and imaging advances, meticulous knowledge of the normal and variant anatomy of the renal vasculature is important to avoid potential pitfalls. We report a case of an accessory renal vein arising from the right kidney, and draining into the inferior ...

  18. Xpand chest drain: assessing equivalence to current standard ...

    African Journals Online (AJOL)

    The Xpand chest drain is an external medical device made of plastic that incorporates a fluid reservoir, a one-way valve and an air-leak detection system ... conect ed to a 2 000 ml drainage bag) prevents exposure of body fluids to nursing staff.

  19. English and the Brain Drain : An Uncertain Relationship

    NARCIS (Netherlands)

    Houtkamp, C.

    2016-01-01

    In his book Linguistic Justice for Europe and the World, Van Parijs analyses in one of his chapters the brain drain from non-Anglophone to Anglophone countries, which hurts the economic development of the nonAnglophone states. Van Parijs deems it clear that English is a very important factor to

  20. Organic loss in drained wetland: managing the carbon footprint

    NARCIS (Netherlands)

    Durham, B.; van de Noort, R.; Martens, V.V.; Vorenhout, M.

    2012-01-01

    The recent installation of land drains at Star Carr, Yorkshire, UK, has been linked with loss of preservation quality in this important Mesolithic buried landscape, challenging the PARIS principle. Historically captured organic carbon, including organic artefacts, is being converted to soluble

  1. Brain Drain in Higher Education: Lost Hope or Opportunity?

    Science.gov (United States)

    Odhiambo, George

    2012-01-01

    The flight of human capital is a phenomenon that has been of concern to academics and development practitioners for decades but unfortunately, there is no systematic record of the number of skilled professionals that many African countries have continued to lose to the developed world. Termed the "brain drain", it represents the loss of…

  2. Draining Collars and Lenses in Liquid-Lined Vertical Tubes.

    Science.gov (United States)

    Jensen

    2000-01-01

    The speed at which an annular liquid collar drains under gravity g in a vertical tube of radius a, when the tube has an otherwise thin viscous liquid lining on its interior, is determined by a balance between the collar's weight and viscous shear stresses confined to narrow regions in the neighborhood of the collar's effective contact lines. Whether a collar grows or shrinks in volume as it drains depends on the modified Bond number B=rho g a(2)/(sigmaepsilon), where rho is the fluid density, sigma is its surface tension, and epsilona is the thickness of the thin film immediately ahead of the collar. Asymptotic methods are used here to determine the following nonlinear stability criteria for an individual collar, valid in the limit of small epsilon. For 0draining collars grow in volume and, in sufficiently long tubes, ultimately "snap off" to form stable lenses. For 0.5960drain, so that any lens ultimately ruptures, unless stabilizing intermolecular forces allow the formation of a lamella supported by a macroscopic Plateau border. If surfactant immobilizes the liquid's free surface, these critical values of B are reduced by a factor of 2 but the distance a collar must travel before it snaps off is unchanged. Gravitationally driven snap off is therefore most likely to occur in long tubes with radii substantially less than the capillary lengthscale sigma/rhog)(1/2). Copyright 2000 Academic Press.

  3. Phosphorus modeling in tile drained agricultural systems using APEX

    Science.gov (United States)

    Phosphorus losses through tile drained systems in agricultural landscapes may be causing the persistent eutrophication problems observed in surface water. The purpose of this paper is to evaluate the state of the science in the Agricultural Policy/Environmental eXtender (APEX) model related to surf...

  4. Drains after Thyroidectomy for Benign Thyroid Disorders; Are ...

    African Journals Online (AJOL)

    Prophylactic drainage after thyroidectomy has been a regular practice at Kenyatta National Hospital( KNH). This has been ... stay and post-operative pain. Introduction. Prophylactic drains are still regularly used in ..... Total versus subtotal thyroidectomy for the management of benign multinodular goiter in an endemic region.

  5. Anomie and the "Brain Drain": A Sociological Explanation.

    Science.gov (United States)

    Karadima, Oscar

    The concept of anomie is proposed as one sociological variable that may explain the "brain drain" phenomenon (i.e., the movement of highly qualified personnel from their country of origin to another, most often a more developed, technologically advanced country). It is hypothesized that the higher the level of anomie found among…

  6. Timing of Re-Transfusion Drain Removal Following Total Knee Replacement

    Science.gov (United States)

    Leeman, MF; Costa, ML; Costello, E; Edwards, D

    2006-01-01

    INTRODUCTION The use of postoperative drains following total knee replacement (TKR) has recently been modified by the use of re-transfusion drains. The aim of our study was to investigate the optimal time for removal of re-transfusion drains following TKR. PATIENTS AND METHODS The medical records of 66 patients who had a TKR performed between October 2003 and October 2004 were reviewed; blood drained before 6 h and the total volume of blood drained was recorded. RESULTS A total of 56 patients had complete records of postoperative drainage. The mean volume of blood collected in the drain in the first 6 h was 442 ml. The mean total volume of blood in the drain was 595 ml. Therefore, of the blood drained, 78% was available for transfusion. CONCLUSION Re-transfusion drains should be removed after 6 h, when no further re-transfusion is permissible. PMID:16551400

  7. Origin of the water drained by the tunnel Graton

    International Nuclear Information System (INIS)

    Plata B, A.

    1992-12-01

    The research of the origin of the water drained by the Graton tunnel was attempted using isotope techniques. During the period of studies (April 1989-October 1992), four field work was executed to sample waters for chemistry, stable isotope and Tritium analysis, an to inject tracers and verify the possible infiltration from the Rimac and Blanco rivers to the tunnel. The results of the stable isotope analysis show that the water drained by the Graton tunnel comes from a basin around 300 meters above the average altitude of the basin where the Graton is located. The Tritium analysis show that the water is relatively modern. Using the model of total mixing, the residence times of the water drained at the km 0.5 and 2.5 are in the order to 45 years. The conductivities of the water of the tunnel is higher than the Rimac river ones because the influence of mine water. The chemical analysis of the water sampled at the downstream end of the tunnel, show that the conservative ions of the water kept almost constant during more than two years. The results of the work with artificial tracer show that there is no significant leakage from the Rimac and Blanco rivers to the Graton tunnel. So far, it can be concluded as a preliminary approach that the Graton tunnel drains relatively modern water originated in another basin. The hydrodynamics of the area of study seems to include a large storage on underground water in the system. The topography, geology and isotopic composition of the water samples, points to the upper Mantaro river basin as the possible source of part of the water drained by the Graton tunnel. (authors). 20 p. 2 figs., 7 ills., 4 tabs

  8. Perioperative lumbar drain utilization in transsphenoidal pituitary resection.

    Science.gov (United States)

    Alharbi, Shatha; Harsh, Griffith; Ajlan, Abdulrazag

    2018-01-01

    To evaluate lumbar drain (LD) efficacy in transnasal resection of pituitary macroadenomas in preventing postoperative cerebrospinal fluid (CSF) leak, technique safety, and effect on length of hospital stay. We conducted a retrospective data review of pituitary tumor patients in our institution who underwent surgery between December 2006 and January 2013. All patients were operated on for complete surgical resection of pituitary macroadenoma tumors. Patients were divided into 2 groups: group 1 received a preoperative drain, while LD was not preoperatively inserted in group 2. In cases of tumors with suprasellar extension with anticipation of high-flow leak, LD was inserted after the patient was intubated and in a lateral position. Lumbar drain was used for 48 hours, and the drain was removed if no leak was observed postoperatively. In documented postoperative CSF leak patients with no preoperative drain, the leak was treated by LD trial prior to surgical reconstruction. Cases in which leak occurred 6 months postoperatively were excluded. Our study population consisted of 186 patients, 99 women (53%) and 87 men (47%), with a mean age of 50.3+/-16.1 years. Complications occurred in 7 patients (13.7%) in group 1 versus 21 (15.5%) in group 2 (p=0.72). Postoperative CSF leak was observed in 1 patient (1.9%) in group 1 and 7 (5%) in group 2 (Fisher exact test=0.3). Length of hospital stay was a mean of 4.7+/-1.9 days in group 1 and a mean of 2.7+/-2.4 days in group 2 (pLD insertion is generally considered safe with a low risk of complications, it increases the length of hospitalization. Minor complications include headaches and patient discomfort.

  9. Investigation on effectiveness of a prefabricated vertical drain during cyclic loading

    International Nuclear Information System (INIS)

    Indraratna, B; Ni, J; Rujikiatkamjorn, C

    2010-01-01

    The effectiveness of prefabricated vertical drains (PVDs) in enhancing the stability of soft soils during cyclic loading was investigated using triaxial cyclic loading tests. Both undrained and with PVD tests were employed to study the associated excess pore pressure and accumulated strain under the repeated loading condition. The loading frequency and cyclic stress ratio have been chosen to be the variables which influence the performance of soft clays. The experimental results illustrate that with PVDs, the excess pore water pressure generation during cyclic loading decreases significantly. It is found that the excess pore water pressure build up depends on both loading frequency and cyclic stress ratio. The excess pore water pressure will increase when each of them is increased. Furthermore, when the loading frequency is 0.1 Hz, the ratio of coefficient of consolidation under cyclic loading to that under static loading is almost one. With the increasing loading frequency, this ratio increases accordingly.

  10. Partitioning Carbon Dioxide Emission and Assessing Dissolved Organic Carbon Leaching of a Drained Peatland Cultivated with Pineapple at Saratok, Malaysia

    Directory of Open Access Journals (Sweden)

    Liza Nuriati Lim Kim Choo

    2014-01-01

    Full Text Available Pineapples (Ananas comosus (L. Merr. cultivation on drained peats could affect the release of carbon dioxide (CO2 into the atmosphere and also the leaching of dissolved organic carbon (DOC. Carbon dioxide emission needs to be partitioned before deciding on whether cultivated peat is net sink or net source of carbon. Partitioning of CO2 emission into root respiration, microbial respiration, and oxidative peat decomposition was achieved using a lysimeter experiment with three treatments: peat soil cultivated with pineapple, bare peat soil, and bare peat soil fumigated with chloroform. Drainage water leached from cultivated peat and bare peat soil was also analyzed for DOC. On a yearly basis, CO2 emissions were higher under bare peat (218.8 t CO2 ha/yr than under bare peat treated with chloroform (205 t CO2 ha/yr, and they were the lowest (179.6 t CO2 ha/yr under cultivated peat. Decreasing CO2 emissions under pineapple were attributed to the positive effects of photosynthesis and soil autotrophic activities. An average 235.7 mg/L loss of DOC under bare peat suggests rapid decline of peat organic carbon through heterotrophic respiration and peat decomposition. Soil CO2 emission depended on moderate temperature fluctuations, but it was not affected by soil moisture.

  11. Characteristics of dissolved organic matter in the Upper Klamath River, Lost River, and Klamath Straits Drain, Oregon and California

    Science.gov (United States)

    Goldman, Jami H.; Sullivan, Annett B.

    2017-12-11

    Concentrations of particulate organic carbon (POC) and dissolved organic carbon (DOC), which together comprise total organic carbon, were measured in this reconnaissance study at sampling sites in the Upper Klamath River, Lost River, and Klamath Straits Drain in 2013–16. Optical absorbance and fluorescence properties of dissolved organic matter (DOM), which contains DOC, also were analyzed. Parallel factor analysis was used to decompose the optical fluorescence data into five key components for all samples. Principal component analysis (PCA) was used to investigate differences in DOM source and processing among sites.At all sites in this study, average DOC concentrations were higher than average POC concentrations. The highest DOC concentrations were at sites in the Klamath Straits Drain and at Pump Plant D. Evaluation of optical properties indicated that Klamath Straits Drain DOM had a refractory, terrestrial source, likely extracted from the interaction of this water with wetland peats and irrigated soils. Pump Plant D DOM exhibited more labile characteristics, which could, for instance, indicate contributions from algal or microbial exudates. The samples from Klamath River also had more microbial or algal derived material, as indicated by PCA analysis of the optical properties. Most sites, except Pump Plant D, showed a linear relation between fluorescent dissolved organic matter (fDOM) and DOC concentration, indicating these measurements are highly correlated (R2=0.84), and thus a continuous fDOM probe could be used to estimate DOC loads from these sites.

  12. An experimental study about efficacy of the drain catheters

    Energy Technology Data Exchange (ETDEWEB)

    Ahn, Bum Gyu; Nho, Joon Young; Woo, Hyo Cheol; Hwang, Woo Cheol; Park, Choong Ki; Yoon, Jong Sup [Hallym University College of Medicine, Seoul (Korea, Republic of)

    1993-09-15

    Although percutaneous abscess drainage has become and accepted alternative from of therapy for selected patients with abscess, it is well known that there are several factors in the failure of adequate drainage such as pre- and post-procedural management, technique itself, various features of abscess, and selection and application of catheters. Among these factors, we made an experiment about drainage efficacy of commonly used various catheters with different viscosities of water-glycerin solution under the two different pressure gradients. The experimental values of flow rate were very lower than the calculated values. An efficacy of experimental value was 4-14%. Because the inner diameter of fittings and stopcocks was usually smaller than the inner diameter of catheters, these factors also affected the drain efficacy. Finally, we thought that it will be very helpful to the treatment of patient as well as to study about the catheter drainage, if the drain efficacy of individual catheters has been notified.

  13. External Suction and Fluid Output in Chest Drains After Lobectomy

    DEFF Research Database (Denmark)

    Lijkendijk, Marike; Neckelmann, Kirsten; Licht, Peter B

    2018-01-01

    influences the amount of fluid. METHODS: We randomly assigned (1:1) 106 patients who underwent lobectomy to either low (-5 cm H2O) or high (-20 cm H2O) external suction using an electronic chest drainage system. Only one chest drain was allowed, and we used strict algorithms for chest drain removal, which...... was delegated to staff nurses: air leakage less than 20 mL/min for 6 hours regardless of fluid output, provided it was serous. The primary end point was fluid output after 24 and 48 hours. RESULTS: Mean fluid output was significantly higher with high suction after both 24 (338 ± 265 mL versus 523 ± 215 m...

  14. 'Brain drain' from Serbia: One face of globalization of education?

    Directory of Open Access Journals (Sweden)

    Avramović Zoran

    2012-01-01

    Full Text Available In this paper we point out the role of the practice and ideology of globalization in brain drain process from Serbia. The listed data are based on the large-scale departure of highly educated persons from Serbia to the counties of West Europe and the USA. The dynamics, proportions and tendencies are analysed the role of the educational system in the process of departure of highly educated people and the reasons and consequences of the departure of scientist and engineering experts. In this article, education policy as state financial support are critical analysed. For Serbia, as the relatively undeveloped country in the middle of the modernization processes, this process has far-reaching effects on the social development. So, here we implied the possible solutions for the problem of brain drain.

  15. Reduction in wick drain effectiveness with spacing for Utah silts and clays.

    Science.gov (United States)

    2012-04-01

    Although decreasing the spacing of vertical drains usually decreases the time for consolidation, previous field tests have shown that there is a critical drain spacing for which tighter spacing does not decrease the time for consolidation. This...

  16. Brain drain: a challenge to global mental health

    OpenAIRE

    Oladeji, Bibilola D.; Gureje, Oye

    2016-01-01

    The brain drain of medical professionals from lower-income to higher-income countries contributes to the current inequity that characterises access to mental healthcare by those in need across the world and hinders efforts to scale up mental health services in resource-constrained settings, especially in Nigeria and other West African countries. The migration of skilled workers is driven by a combination of the globalisation of the labour market and the ability of highly resourced countries t...

  17. Outcome in Chronic Subdural Hematoma After Subdural vs. Subgaleal Drain

    International Nuclear Information System (INIS)

    Ishfaq, A.

    2017-01-01

    Objective: To compare the outcome after surgery for chronic subdural hematoma when the drain is placed in subdural space or subgaleal space. Study Design: Quasi experimental study. Place and Duration of Study: Combined Military Hospital, Lahore, from July 2015 to June 2016. Methodology: Patients with chronic subdural hematoma of both genders and age, ranging between 55 to 85 years, were included. Patients on antiplatelet/anticoagulant therapy and acute on chronic subdural hematoma were excluded. Patients were divided in two equal groups each depending on whether drain was placed in subgaleal space (Group 1), and subdual space (Group 2), (n=31 patients each). Patients were positioned flat in bed after surgery. Clinical and radiological parameters and clinical outcome were compared between the two groups. Statistical test with significance of p <0.05 was utilized using Statistical Package of Social Sciences (SPSS version 17). Results: Median age of the 62 patients was 72 +-12.5 years. Headache was the most common symptom reported in both groups, (n=47,75.8%) patients. Median thickness of hematoma was 15 +-6.5 mm. Patients with subdural drain placement had more complications such as pneumocephalus 11 (35.4%) vs. 6 (19.3%), and intracerebral hemorrhage 4 (12.9%) vs. 2 (6.4%). Clinical outcome was good in both groups 27 (87%) in Group 1 and 28 (90%) in Group 2. Conclusion: Patients of both groups had good outcome after surgery. Complications like pneumocephalus and intracerebral hemorrhage were more common in subdural location of drain, though not reaching statistically significance level to favor one technique over another. (author)

  18. Consolidation by Prefabricated Vertical Drains with a Threshold Gradient

    OpenAIRE

    Xiao Guo; Kang-He Xie; Yue-Bao Deng

    2014-01-01

    This paper shows the development of an approximate analytical solution of radial consolidation by prefabricated vertical drains with a threshold gradient. To understand the effect of the threshold gradient on consolidation, a parametric analysis was performed using the present solution. The applicability of the present solution was demonstrated in two cases, wherein the comparisons with Hansbo’s results and observed data were conducted. It was found that (1) the flow with the threshold gradie...

  19. Globalization and migration: A "unified brain drain" model

    OpenAIRE

    Brezis, Elise S.; Soueri, Ariel

    2012-01-01

    Globalization has led to a vast flow of migration of workers but also of students. The purpose of this paper is to analyze the migration of individuals encompassing decisions already at the level of education. We develop a unified brain drain model that incorporates the decisions of an individual vis - à - vis both education and migration. In the empirical part, this paper addresses international flows of migration within the EU and presents strong evidence of concentration of students in cou...

  20. Drain site evisceration of fallopian tube, another reason to discourage abdominal drain: report of a case and brief review of literature.

    Science.gov (United States)

    Saini, Pradeep; Faridi, M S; Agarwal, Nitin; Gupta, Arun; Kaur, Navneet

    2012-04-01

    Placement of a drain following abdominal surgery is common despite a lack of convincing evidence in the current literature to support this practice. The use of intra-abdominal drain is associated with many potential and serious complications. We report a drain site evisceration of the right fallopian tube after the removal of an intra-abdominal drain. The drain was placed in the right iliac fossa in a patient who underwent a lower segment Caesarean section (LSCS) for meconium liquor with fetal distress. The Pfannenstiel incision made for LSCS was reopened and the protruding inflamed fimbrial end of the right fallopian tube was excised. The patient made an uneventful recovery. Routine intra-abdominal prophylactic drain following an abdominal surgery including LSCS should be discouraged.

  1. Soil surface CO2 flux in a boreal black spruce fire chronosequence

    Science.gov (United States)

    Wang, Chuankuan; Bond-Lamberty, Ben; Gower, Stith T.

    2003-02-01

    Understanding the effects of wildfire on the carbon (C) cycle of boreal forests is essential to quantifying the role of boreal forests in the global carbon cycle. Soil surface CO2 flux (Rs), the second largest C flux in boreal forests, is directly and indirectly affected by fire and is hypothesized to change during forest succession following fire. The overall objective of this study was to measure and model Rs for a black spruce (Picea mariana [Mill.] BSP) postfire chronosequence in northern Manitoba, Canada. The experiment design was a nested factorial that included two soil drainage classes (well and poorly drained) × seven postfire aged stands. Specific objectives were (1) to quantify the relationship between Rs and soil temperature for different aged boreal black spruce forests in well-drained and poorly drained soil conditions, (2) to examine Rs dynamics along postfire successional stands, and (3) to estimate annual soil surface CO2 flux for these ecosystems. Soil surface CO2 flux was significantly affected by soil drainage class (p = 0.014) and stand age (p = 0.006). Soil surface CO2 flux was positively correlated to soil temperature (R2 = 0.78, p aged stand combination. Soil surface CO2 flux was significantly greater at the well-drained than the poorly drained stands (p = 0.007) during growing season. Annual soil surface CO2 flux for the 1998, 1995, 1989, 1981, 1964, 1930, and 1870 burned stands averaged 226, 412, 357, 413, 350, 274, and 244 g C m-2 yr-1 in the well-drained stands and 146, 380, 300, 303, 256, 233, and 264 g C m-2 yr-1 in the poorly drained stands. Soil surface CO2 flux during the winter (from 1 November to 30 April) comprised from 5 to 19% of the total annual Rs. We speculate that the smaller soil surface CO2 flux in the recently burned than the older stands is mainly caused by decreased root respiration.

  2. Leachates draining from controlled municipal solid waste landfill: Detailed geochemical characterization and toxicity tests.

    Science.gov (United States)

    Mavakala, Bienvenu K; Le Faucheur, Séverine; Mulaji, Crispin K; Laffite, Amandine; Devarajan, Naresh; Biey, Emmanuel M; Giuliani, Gregory; Otamonga, Jean-Paul; Kabatusuila, Prosper; Mpiana, Pius T; Poté, John

    2016-09-01

    Management of municipal solid wastes in many countries consists of waste disposal into landfill without treatment or selective collection of solid waste fractions including plastics, paper, glass, metals, electronic waste, and organic fraction leading to the unsolved problem of contamination of numerous ecosystems such as air, soil, surface, and ground water. Knowledge of leachate composition is critical in risk assessment of long-term impact of landfills on human health and the environment as well as for prevention of negative outcomes. The research presented in this paper investigates the seasonal variation of draining leachate composition and resulting toxicity as well as the contamination status of soil/sediment from lagoon basins receiving leachates from landfill in Mpasa, a suburb of Kinshasa in the Democratic Republic of the Congo. Samples were collected during the dry and rainy seasons and analyzed for pH, electrical conductivity, dissolved oxygen, soluble ions, toxic metals, and were then subjected to toxicity tests. Results highlight the significant seasonal difference in leachate physicochemical composition. Affected soil/sediment showed higher values for toxic metals than leachates, indicating the possibility of using lagoon system for the purification of landfill leachates, especially for organic matter and heavy metal sedimentation. However, the ecotoxicity tests demonstrated that leachates are still a significant source of toxicity for terrestrial and benthic organisms. Therefore, landfill leachates should not be discarded into the environment (soil or surface water) without prior treatment. Interest in the use of macrophytes in lagoon system is growing and toxic metal retention in lagoon basin receiving systems needs to be fully investigated in the future. This study presents useful tools for evaluating landfill leachate quality and risk in lagoon systems which can be applied to similar environmental compartments. Copyright © 2016 Elsevier Ltd. All

  3. The Simple Urine Bag as Wound Drain Post-Craniotomy in a Low ...

    African Journals Online (AJOL)

    Methods: A 4-year prospective cohort study of the effectiveness, outcome with use and complications of the Uribag as post craniotomy wound drain in a consecutive cohort of neurosurgical patients. Data analyzed include the patients' brief demographics; the types of cranial surgery in which drain was used; the drain ...

  4. 76 FR 62605 - Virginia Graeme Baker Pool and Spa Safety Act; Interpretation of Unblockable Drain

    Science.gov (United States)

    2011-10-11

    ... the VGB Act defines an ``unblockable drain'' as ``a drain of any size and shape that a human body... intentions. They claim that for this reason, backup systems are necessary, and a swimming pool or spa with a... of an ``unblockable drain,'' at 16 CFR 1450.2(b) and believe it was in error. Regardless of the size...

  5. Draining after breast reduction: a randomised controlled inter-patient study

    NARCIS (Netherlands)

    Corion, Leonard U. M.; Smeulders, Mark J. C.; van Zuijlen, Paul P. M.; van der Horst, Chantal M. A. M.

    2009-01-01

    One hundred and seven bilateral breast reductions were prospectively randomised during surgery to receive or not receive wound drains. Fifty-five patients were randomised to have a drain and 52 to not have a drain. There was no statistical difference in the number of complications between the

  6. An economic perspective on Malawi's medical "brain drain"

    Directory of Open Access Journals (Sweden)

    Mohiddin Abdu

    2006-12-01

    Full Text Available Abstract Background The medical "brain drain" has been described as rich countries "looting" doctors and nurses from developing countries undermining their health systems and public health. However this "brain-drain" might also be seen as a success in the training and "export" of health professionals and the benefits this provides. This paper illustrates the arguments and possible policy options by focusing on the situation in one of the poorest countries in the world, Malawi. Discussion Many see this "brain drain" of medical staff as wrong with developed countries exploiting poorer ones. The effects are considerable with Malawi facing high vacancy rates in its public health system, and with migration threatening to outstrip training despite efforts to improve pay and conditions. This shortage of staff has made it more challenging for Malawi to deliver on its Essential Health Package and to absorb new international health funding. Yet, without any policy effort Malawi has been able to demonstrate its global competitiveness in the training ("production" of skilled health professionals. Remittances from migration are a large and growing source of foreign exchange for poor countries and tend to go directly to households. Whilst the data for Malawi is limited, studies from other poor countries demonstrate the power of remittances in significantly reducing poverty. Malawi can benefit from the export of health professionals provided there is a resolution of the situation whereby the state pays for training and the benefits are gained by the individual professional working abroad. Solutions include migrating staff paying back training costs, or rich host governments remitting part of a tax (e.g. income or national insurance to the Malawi government. These schemes would allow Malawi to scale up training of health professionals for local needs and to work abroad. Summary There is concern about the negative impacts of the medical "brain-drain". However a

  7. An economic perspective on Malawi's medical "brain drain"

    Science.gov (United States)

    Record, Richard; Mohiddin, Abdu

    2006-01-01

    Background The medical "brain drain" has been described as rich countries "looting" doctors and nurses from developing countries undermining their health systems and public health. However this "brain-drain" might also be seen as a success in the training and "export" of health professionals and the benefits this provides. This paper illustrates the arguments and possible policy options by focusing on the situation in one of the poorest countries in the world, Malawi. Discussion Many see this "brain drain" of medical staff as wrong with developed countries exploiting poorer ones. The effects are considerable with Malawi facing high vacancy rates in its public health system, and with migration threatening to outstrip training despite efforts to improve pay and conditions. This shortage of staff has made it more challenging for Malawi to deliver on its Essential Health Package and to absorb new international health funding. Yet, without any policy effort Malawi has been able to demonstrate its global competitiveness in the training ("production") of skilled health professionals. Remittances from migration are a large and growing source of foreign exchange for poor countries and tend to go directly to households. Whilst the data for Malawi is limited, studies from other poor countries demonstrate the power of remittances in significantly reducing poverty. Malawi can benefit from the export of health professionals provided there is a resolution of the situation whereby the state pays for training and the benefits are gained by the individual professional working abroad. Solutions include migrating staff paying back training costs, or rich host governments remitting part of a tax (e.g. income or national insurance) to the Malawi government. These schemes would allow Malawi to scale up training of health professionals for local needs and to work abroad. Summary There is concern about the negative impacts of the medical "brain-drain". However a closer look at the evidence

  8. Subsoil erosion dominates the supply of fine sediment to rivers draining into Princess Charlotte Bay, Australia

    International Nuclear Information System (INIS)

    Olley, Jon; Brooks, Andrew; Spencer, John; Pietsch, Timothy; Borombovits, Daniel

    2013-01-01

    The Laura–Normanby River (catchment area: 24,350 km 2 ), which drains into Princess Charlotte Bay, has been identified in previous studies as the third largest contributor of sediment to the Great Barrier Reef World Heritage Area. These catchment scale modelling studies also identified surface soil erosion as supplying >80% of the sediment. Here we use activity concentrations of the fallout radionuclides 137 Cs and 210 Pb ex to test the hypothesis that surface soil erosion dominates the supply of fine ( 137 Cs and 210 Pb ex activity concentrations between samples collected using these two methods. Two methods were also used to collect samples to characterise 137 Cs and 210 Pb ex concentrations in sediment derived from surface soil erosion; sampling of surface-wash deposits and deployment of surface runoff traps that collected samples during rain events. While there was no difference in the 137 Cs activity concentrations for samples collected using these two methods, 210 Pb ex activity concentrations were significantly higher in the samples collected using the runoff traps. The higher 210 Pb ex concentrations are shown to be correlated with loss-on-ignition (r 2 = 0.79) and therefore are likely to be related to higher organic concentrations in the runoff trap samples. As a result of these differences we use a three end member mixing model (channel/gully, hillslope surface-wash and hillslope runoff traps) to determine the relative contribution from surface soil erosion. Probability distributions for 137 Cs and 210 Pb ex concentrations were determined for each of the end members, with these distributions then used to estimate the surface soil contribution to each of the collected river sediment samples. The mean estimate of contribution of surface derived sediment for all river samples (n = 70) is 16 ± 2%. This study reinforces the importance of testing model predictions before they are used to target investment in remedial action and adds to the body of evidence

  9. Investigation of the effects of slow-release fertilizer and struvite in biodegradation in filter drains and potential application of treated water in irrigation of road verges.

    Science.gov (United States)

    Theophilus, Stephen C; Mbanaso, Fredrick U; Nnadi, Ernest O; Onyedeke, Kingsley T

    2017-11-14

    Filter drains are usually laid along the margins of highways. Highway runoffs are polluted with hydrocarbons and high levels of total dissolved solids. Therefore, effective pollution removal mechanism is necessary in order to avoid contamination of surrounding soils and groundwater. Biodegradation is amongst pollution removal mechanisms in filter drains, but it is a relatively slow process which is dependent on wide range of factors including the type of pollutant and availability of nutrients. This paper reports on a study conducted to investigate the impact of slow-release fertilizer and struvite in enhancement of biodegradation of hydrocarbon in filter drains. Filter drain models incorporated with geotextile were challenged with cumulative oil loading of 178 mg/m 2 /week with a view to comparing the efficiency of these two nutrient sources under high oil pollution loading and realistic rainfall conditions of 13 mm/week. Nutrients and street dust were applied at one-off rate of 17 g/m 2 and 1.55 g/rig to provide nutrient enhancement and simulate field conditions respectively. The impact of the nutrients was studied by monitoring bacterial and fungal growth using nutrient agar, Rose Bengal Agar media and CO2 evolution. EC, pH, heavy metals, TPH, elemental analysis and SAR were used to investigate water quality of effluent of filter drains for potential application as irrigation fluid for trees and flowers planted on road verges. The results show that nutrient application encouraged microbial activities and enhanced biodegradation rates with differences in type of nutrient applied. Also, it was observed that incorporation of geotextiles in filter drains improved pollution retention efficiency and there is a potential opportunity for utilization of struvite in SuDS systems as sustainable nutrient source.

  10. Iatrogenic Perforation of the Left Ventricle during Insertion of a Chest Drain

    OpenAIRE

    Kim, Dongmin; Lim, Seong-Hoon; Seo, Pil Won

    2013-01-01

    Chest draining is a common procedure for treating pleural effusion. Perforation of the heart is a rare often fatal complication of chest drain insertion. We report a case of a 76-year-old female patient suffering from congestive heart failure. At presentation, unilateral opacity of the left chest observed on a chest X-ray was interpreted as massive pleural effusion, so an attempt was made to drain the left pleural space. Malposition of the chest drain was suspected because blood was draining ...

  11. Soil physics and the water management of spatially variable soils

    International Nuclear Information System (INIS)

    Youngs, E.G.

    1983-01-01

    The physics of macroscopic soil-water behaviour in inert porous materials has been developed by considering water flow to take place in a continuum. This requires the flow region to consist of an assembly of representative elementary volumes, repeated throughout space and small compared with the scale of observations. Soil-water behaviour in swelling soils may also be considered as a continuum phenomenon so long as the soil is saturated and swells and shrinks in the normal range. Macroscale heterogeneity superimposed on the inherent microscale heterogeneity can take many forms and may pose difficulties in the definition and measurement of soil physical properties and also in the development and use of predictive theories of soil-water behaviour. Thus, measurement techniques appropriate for uniform soils are often inappropriate, and criteria for soil-water management, obtained from theoretical considerations of behaviour in equivalent uniform soils, are not applicable without modification when there is soil heterogeneity. The spatial variability of soil-water properties is shown in results from field experiments concerned with water flow measurements; these illustrate both stochastic and deterministic heterogeneity in soil-water properties. Problems of water management of spatially variable soils when there is stochastic heterogeneity appear to present an insuperable problem in the application of theory. However, for soils showing deterministic heterogeneity, soil-water theory has been used in the solution of soil-water management problems. Thus, scaling using similar media theory has been applied to the infiltration of water into soils that vary over a catchment area. Also, the drain spacing to control the water-table height in soils in which the hydraulic conductivity varies with depth has been calculated using groundwater seepage theory. (author)

  12. Tracking the origin and dispersion of contaminated sediments transported by rivers draining the Fukushima radioactive contaminant plume

    Directory of Open Access Journals (Sweden)

    H. Lepage

    2015-03-01

    Full Text Available This study was conducted in several catchments draining the main Fukushima Dai-ichi Power Plant contaminant plume in Fukushima prefecture, Japan. We collected soils and sediment drape deposits (n = 128 and investigated the variation in 137Cs enrichment during five sampling campaigns, conducted every six months, which typically occurred after intense erosive events such as typhoons and snowmelt. We show that upstream contaminated soils are eroded during summer typhoons (June–October before being exported during the spring snowmelt (March–April. However, this seasonal cycle of sediment dispersion is further complicated by the occurrence of dam releases that may discharge large amounts of contaminants to the coastal plains during the coming years.

  13. Greenhouse gas flux measurements in a forestry-drained peatland indicate a large carbon sink

    Directory of Open Access Journals (Sweden)

    A. Lohila

    2011-11-01

    Full Text Available Drainage for forestry purposes increases the depth of the oxic peat layer and leads to increased growth of shrubs and trees. Concurrently, the production and uptake of the greenhouse gases carbon dioxide (CO2, methane (CH4 and nitrous oxide (N2O change: due to the accelerated decomposition of peat in the presence of oxygen, drained peatlands are generally considered to lose peat carbon (C. We measured CO2 exchange with the eddy covariance (EC method above a drained nutrient-poor peatland forest in southern Finland for 16 months in 2004–2005. The site, classified as a dwarf-shrub pine bog, had been ditched about 35 years earlier. CH4 and N2O fluxes were measured at 2–5-week intervals with the chamber technique. Drainage had resulted in a relatively little change in the water table level, being on average 40 cm below the ground in 2005. The annual net ecosystem exchange was −870 ± 100 g CO2 m−2 yr−1 in the calendar year 2005, indicating net CO2 uptake from the atmosphere. The site was a small sink of CH4 (−0.12 g CH4 m−2 yr−1 and a small source of N2O (0.10 g N2O m−2 yr−1. Photosynthesis was detected throughout the year when the air temperature exceeded −3 °C. As the annual accumulation of C in the above and below ground tree biomass (175 ± 35 g C m−2 was significantly lower than the accumulation observed by the flux measurement (240 ± 30 g C m−2, about 65 g C m−2 yr−1 was likely to have accumulated as organic matter into the peat soil. This is a higher average accumulation rate than previously reported for natural northern peatlands, and the first time C accumulation has been shown by EC measurements to occur in a forestry-drained peatland. Our results suggest that forestry

  14. Tile drainage as karst: Conduit flow and diffuse flow in a tile-drained watershed

    Science.gov (United States)

    Schilling, K.E.; Helmers, M.

    2008-01-01

    The similarity of tiled-drained watersheds to karst drainage basins can be used to improve understanding of watershed-scale nutrient losses from subsurface tile drainage networks. In this study, short-term variations in discharge and chemistry were examined from a tile outlet collecting subsurface tile flow from a 963 ha agricultural watershed. Study objectives were to apply analytical techniques from karst springs to tile discharge to evaluate water sources and estimate the loads of agricultural pollutants discharged from the tile with conduit, intermediate and diffuse flow regimes. A two-member mixing model using nitrate, chloride and specific conductance was used to distinguish rainwater versus groundwater inputs. Results indicated that groundwater comprised 75% of the discharge for a three-day storm period and rainwater was primarily concentrated during the hydrograph peak. A contrasting pattern of solute concentrations and export loads was observed in tile flow. During base flow periods, tile flow consisted of diffuse flow from groundwater sources and contained elevated levels of nitrate, chloride and specific conductance. During storm events, suspended solids and pollutants adhered to soil surfaces (phosphorus, ammonium and organic nitrogen) were concentrated and discharged during the rapid, conduit flow portion of the hydrograph. During a three-day period, conduit flow occurred for 5.6% of the time but accounted for 16.5% of the total flow. Nitrate and chloride were delivered primarily with diffuse flow (more than 70%), whereas 80-94% of total suspended sediment, phosphorus and ammonium were exported with conduit and intermediate flow regimes. Understanding the water sources contributing to tile drainage and the manner by which pollutant discharge occurs from these systems (conduit, intermediate or diffuse flow) may be useful for designing, implementing and evaluating non-point source reduction strategies in tile-drained landscapes. ?? 2007 Elsevier B.V. All

  15. Modified APEX model for Simulating Macropore Phosphorus Contributions to Tile Drains.

    Science.gov (United States)

    Ford, William I; King, Kevin W; Williams, Mark R; Confesor, Remegio B

    2017-11-01

    The contribution of macropore flow to phosphorus (P) loadings in tile-drained agricultural landscapes remains poorly understood at the field scale, despite the recognized deleterious impacts of contaminant transport via macropore pathways. A new subroutine that couples existing matrix-excess and matrix-desiccation macropore flow theory and a modified P routine is implemented in the Agricultural Policy Environmental eXtender (APEX) model. The original and modified formulation were applied and evaluated for a case study in a poorly drained field in Western Ohio with 31 months of surface and subsurface monitoring data. Results highlighted that a macropore subroutine in APEX improved edge-of-field discharge calibration and validation for both tile and total discharge from satisfactory and good, respectively, to very good and improved dissolved reactive P load calibration and validation statistics for tile P loads from unsatisfactory to very good. Output from the calibrated macropore simulations suggested median annual matrix-desiccation macropore flow contributions of 48% and P load contributions of 43%, with the majority of loading occurring in winter and spring. While somewhat counterintuitive, the prominence of matrix-desiccation macropore flow during seasons with less cracking reflects the importance of coupled development of macropore pathways and adequate supply of the macropore flow source. The innovative features of the model allow for assessments of annual macropore P contributions to tile drainage and has the potential to inform P site assessment tools. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  16. A retrospective study of the use of active suction wound drains in dogs and cats.

    Science.gov (United States)

    Bristow, P C; Halfacree, Z J; Baines, S J

    2015-05-01

    To report indications for use and complications associated with commonly used closed active suction wound drains in a large number of clinical cases. Retrospective review of medical case records (from 2004 to 2010) for dogs and cats that had a closed active suction drain placed into a wound. Only the four most common drain types were included: Mini Redovac®, Redovac®, Jackson Pratt® and Wound Evac®. Two hundred and fifty-three drains were placed in 33 cats and 195 dogs. Mini Redovac drains were used most frequently in cats (76 · 5%) and Redovac drains in dogs (54 · 3%). The infection rate for clean surgeries in dogs was 15 · 6% (unattainable in cats). Major complications occurred in four dogs; minor complications occurred in 12 drains in cats (35 · 3%), and in 74 drains in dogs (33 · 8%). There was no statistically significant association between the type of drain and complication rate for either species. Although closed active suction drains can be used with low risk of major complications, they lead to a high rate of infection in clean surgeries in dogs. It is recommended that such drains are kept in place for the shortest time possible and that strict asepsis is adhered to both during placement and management. © 2015 British Small Animal Veterinary Association.

  17. Comparison of a large and small-calibre tube drain for managing spontaneous pneumothoraces.

    Science.gov (United States)

    Benton, Ian J; Benfield, Grant F A

    2009-10-01

    To compare treatment success of large- and small-bore chest drains in the treatment of spontaneous pneumothoraces the case-notes were reviewed of those admitted to our hospital with a total of 73 pneumothoraces and who were treated by trainee doctors of varying experience. Both a large- and a small-bore intercostal tube drain system were in use during the two-year period reviewed. Similar pneumothorax profile and numbers treated with both drains were recorded, resulting in a similar drain time and numbers of successful and failed re-expansion of pneumothoraces. Successful pneumothorax resolution was the same for both drain types and the negligible tube drain complications observed with the small-bore drain reflected previously reported experiences. However the large-bore drain was associated with a high complication rate (32%) with more infectious complications (24%). The small-bore drain was prone to displacement (21%). There was generally no evidence of an increased failure and morbidity, reflecting poorer expertise, in the non-specialist trainees managing the pneumothoraces. A practical finding however was that in those large pneumothoraces where re-expansion failed, the tip of the drain had not been sited at the apex of the pleural cavity irrespective of the drain type inserted.

  18. Evisceration of Appendix through the Drain Site: A Rare Case Report.

    Science.gov (United States)

    Ravishankaran, Praveen; Rajamani, A

    2013-06-01

    Placing a drain after surgery is a usual procedure in any emergency abdominal operation. The drain is removed as soon as its purpose of draining the intraabdominal collection in served. Evisceration of intraabdominal organs through the drain site is a rare occurance. This case report is about an 12 year old girl who was admitted with blunt trauma abdomen. After completion of emergency laparotomy a drain was placed in the right lower quadrant. When the drain was removed on the 6th post operative day, the appendix eviscerated out of the drain site. The wound was extended a little and an appendectomy was done. This case is presented for its rarity as only two similar instances have been reported in literature so far.

  19. Runoff losses of sediment and phosphorus from no-till and cultivated soils receiving dairy manure.

    Science.gov (United States)

    Verbree, David A; Duiker, Sjoerd W; Kleinman, Peter J A

    2010-01-01

    Managing manure in no-till systems is a water quality concern because surface application of manure can enrich runoff with dissolved phosphorus (P), and incorporation by tillage increases particulate P loss. This study compared runoff from well-drained and somewhat poorly drained soils under corn (Zea mays, L.) production that had been in no-till for more than 10 yr. Dairy cattle (Bos taurus L.) manure was broadcast into a fall planted cover crop before no-till corn planting or incorporated by chisel/disk tillage in the absence of a cover crop. Rainfall simulations (60 mm h(-1)) were performed after planting, mid-season, and post-harvest in 2007 and 2008. In both years and on both soils, no-till yielded significantly less sediment than did chisel/disking. Relative effects of tillage on runoff and P loss differed with soil. On the well-drained soil, runoff depths from no-till were much lower than with chisel/disking, producing significantly lower total P loads (22-50% less). On the somewhat poorly drained soil, there was little to no reduction in runoff depth with no-till, and total P loads were significantly greater than with chisel/disking (40-47% greater). Particulate P losses outweighed dissolved P losses as the major concern on the well-drained soil, whereas dissolved P from surface applied manure was more important on the somewhat poorly drained soil. This study confirms the benefit of no-till to erosion and total P runoff control on well-drained soils but highlights trade-offs in no-till management on somewhat poorly drained soils where the absence of manure incorporation can exacerbate total P losses.

  20. India: 'brain drain' or the migration of talent?

    Science.gov (United States)

    Oommen, T K

    1989-09-01

    2 views on "brain drain" exist: 1) LDCs lose their enormous investments on higher education when skilled people migrate to other countries and 2) LDCs are exaggerating the problem and only a few skilled people migrate at 1 time. India does not completely lose its investment in education when professionals migrate, since the migrants still contribute to knowledge and also send remittances to relatives in India. Unemployed educated people would cause a greater drain on India's resources than educated migrants. The author prefers the phrase migration of talent to brain drain, since the former indicates a 2-way movement. Most migrants from LDCs are students. About 11,000 university graduates leave India every year for advanced study and/or work. A conservative estimate is that 2500 will remain abroad permanently. Most professionals who migrate go to the US and Canada. Factors promoting migration include 1) unemployment, 2) immigration rules, 3) colonial links, 4) financial incentives and material benefits, 5) pursuit of higher education, 6) improvement of working conditions and facilities, 7) avoidance of excessive bureaucratic procedures, and 8) compensation for the mismatch between Indian education and employment. Reasons for returning to India include 1) deference to wives who were unable to adjust to a foreign way of life, 2) contributing to Indian development, and 3) racial discrimination. It will probably not be possible to lure back migrants who left for material reasons. Attractive job offers could entice back those who left for advanced training. To encourage the return of those who left to pursue high quality research, India must 1) increase expenditure on research and development, possibly through the private industrial sector, 2) promote travel to other countries for professional enrichment, and 3) improve conditions of research work. The article concludes with an analysis of migration of talent from 3 perspectives: 1) the individual, 2) the nation

  1. Processing method for drained water containing ethanol amine

    International Nuclear Information System (INIS)

    Wakuta, Kuniharu; Ogawa, Naoki; Sagawa, Hiroshi; Kamiyoshi, Hideki; Fukunaga, Kazuo; Iwamoto, Ken; Miki, Tsuyoshi; Hirata, Toshio

    1998-01-01

    Drained water containing ethanol amine is processed with microorganisms such as hydrazine resistant denitrification bacteria in a biodegrading vessel (A) in the coexistence of nitrous ions and/or nitric ions under an anaerobic condition, and then it is processed with microorganisms such as nitrification bacteria in another biotic oxidation vessel (B) under an aerobic condition to generate the coexistent nitrate ion and/or nitric ion, and returned to the biodegrading vessel (A). Further, they are exposed to air or incorporated with an oxidant and optionally a copper compound such as copper sulfate as a catalyst is added in a step of removing hydrazine. (T.M.)

  2. Right superior vena cava draining into the left atrium

    Energy Technology Data Exchange (ETDEWEB)

    Calcagni, Giulio; Sidi, Daniel; Bonnet, Damien [University Rene Descartes-Paris 5, Department of Paediatric Cardiology, Hopital Necker-Enfants Malades, Paris (France); Batisse, Alain [Institut de Puericulture et de Perinatalogie, Paris (France); Vouhe, Pascal [University Rene Descartes-Paris 5, Department of Paediatric Cardiac Surgery, Hopital Necker-Enfants Malades, Paris (France); Ou, Phalla [University Rene Descartes-Paris 5, Department of Paediatric Cardiology, Hopital Necker-Enfants Malades, Paris (France); University Rene Descartes-Paris 5, Department of Pediatric Radiology, Hopital Necker-Enfants Malades, Paris (France)

    2008-08-15

    The right superior vena cava draining into the left atrium is a rare malformation causing cyanosis and clubbing in patients in whom no other signs of congenital heart defect are present. Diagnosis may be difficult as cyanosis may be mild and the anomaly is not always easily detectable by echocardiography. For this reason we report a 13-month-old male in whom we confirmed the clinical and echocardiographic suspicion of anomalous drainage of the right superior vena cava using multidetector CT. This allowed successful surgical reconnection of the right superior vena cava to the right atrium. (orig.)

  3. Laparoscopic primary repair and isoperistaltic endoluminal drain for Boerhaave's Syndrome.

    Science.gov (United States)

    Prete, Francesco; Pezzolla, Angela; Nitti, Paolo; Prete, Fernando

    2015-01-01

    Spontaneous oesophageal rupture, also known as Boerhaave syndrome (BS), is a rare and potentially lethal pathological condition. BS recognition is difficult, while rapidity of diagnosis, along with extension of the lesion, affects type and outcome of treatment. BS was classically treated by thoracotomy, but laparoscopic (LS), thoracoscopic (TS) surgery, and nonsurgical procedures as endoscopic stent positioning or use of glues have been described. Still, there is no model treatment, and selection of the most appropriate therapeutic procedure is complex in the absence of standardised criteria. We successfully managed a patient affected with BS by LS approach and present our experience along with a review of treatment options so far described. Our treatment integrated positioning of an oesophageal isoperistaltic endoluminal drain (IED), that we routinely use in oesophageal sutures at risk of leakage, and of which there is no previous report in the setting of BS. A 68 year old man presented to our attention with true BS, suspected on chest-abdominal CT scan and confirmed by upper GI contrast swallow test, showing leakage of hydro-soluble contrast from the lower third of the oesophagus. Of note, pleural cavities appeared intact. We performed an urgent laparoscopy 12 hours after the onset of symptoms. Laparoscopic toilet of the inferior mediastinum and dual layer oesophageal repair with pedicled omental flap were complemented by positioning of IED, feeding jejunostomy and two tubular drains. The patient had a slow but consistent recovery where IED played as a means of oesophageal suture protection, until he could be discharged home. We think that, when integrity of the pleura is documented, LS should be priority choice to avoid contamination of the pleural cavities. We have to consider every type of oesophageal repair in BS at risk of failure, and every means of protection of the suture is opportune. In our patient the oesophageal suture, covered with a flap of omentum

  4. Consequences assessment for fuel channel failure with consequential moderator drain

    International Nuclear Information System (INIS)

    Wahba, N.N.; Bayoumi, M.H.

    2002-01-01

    This paper documents the consequences of spontaneous pressure tube/consequential calandria tube rupture followed by the ejection of end fittings (as a result of guillotine failure of pressure tube) leading to the drain of the moderator. The event is postulated to occur in conjunction with an independent failure of Emergency Coolant Injection System (ECIS). The results of the detailed consequence assessments are used to propose a course of action to mitigate the consequences of such an event. A methodology based on a lumped-parameter model was developed to assess the consequences of the postulated event. (author)

  5. Interior drains for open pit disposal of uranium mill tailings

    International Nuclear Information System (INIS)

    Staub, W.P.

    1978-01-01

    A conceptualized interior drainage system is presented for reducing the environmental impact on natural groundwater by disposal of uranium mill tailings in the mined-out open pit. The evaporation/seepage ratio can be increased through the use of interior drains, long-term monitoring of groundwater quality can be eliminated, and the open pit will not require an extensive liner. Other advantages not related to groundwater are: control of fugitive dust and radon emanation during mill operations and timely reclamation after the impoundment is filled with tailings

  6. Right superior vena cava draining into the left atrium

    International Nuclear Information System (INIS)

    Calcagni, Giulio; Sidi, Daniel; Bonnet, Damien; Batisse, Alain; Vouhe, Pascal; Ou, Phalla

    2008-01-01

    The right superior vena cava draining into the left atrium is a rare malformation causing cyanosis and clubbing in patients in whom no other signs of congenital heart defect are present. Diagnosis may be difficult as cyanosis may be mild and the anomaly is not always easily detectable by echocardiography. For this reason we report a 13-month-old male in whom we confirmed the clinical and echocardiographic suspicion of anomalous drainage of the right superior vena cava using multidetector CT. This allowed successful surgical reconnection of the right superior vena cava to the right atrium. (orig.)

  7. Consolidation by Prefabricated Vertical Drains with a Threshold Gradient

    Directory of Open Access Journals (Sweden)

    Xiao Guo

    2014-01-01

    Full Text Available This paper shows the development of an approximate analytical solution of radial consolidation by prefabricated vertical drains with a threshold gradient. To understand the effect of the threshold gradient on consolidation, a parametric analysis was performed using the present solution. The applicability of the present solution was demonstrated in two cases, wherein the comparisons with Hansbo’s results and observed data were conducted. It was found that (1 the flow with the threshold gradient would not occur instantaneously throughout the whole unit cell. Rather, it gradually occurs from the vertical drain to the outside; (2 the moving boundary would never reach the outer radius of influence if R+1

  8. Global estimates of high-level brain drain and deficit.

    Science.gov (United States)

    Ioannidis, John P A

    2004-06-01

    Brain drain, the international migration of scientists in search of better opportunities, has been a long-standing concern, but quantitative measurements are uncommon and limited to specific countries or disciplines. We need to understand brain drain at a global level and estimate the extent to which scientists born in countries with low opportunities never realize their potential. Data on 1523 of the most highly cited scientists for 1981-1999 are analyzed. Overall, 31.9% of these scientists did not reside in the country where they were born (range 18.1-54.6% across 21 different scientific fields). There was great variability across developed countries in the proportions of foreign-born resident scientists and emigrating scientists. Countries without a critical mass of native scientists lost most scientists to migration. This loss occurred in both developed and developing countries. Adjusting for population and using the U.S. as reference, the number of highly cited native-born scientists was at least 75% of the expected number in only 8 countries other than the U.S. It is estimated that approximately 94% of the expected top scientists worldwide have not been able to materialize themselves due to various adverse conditions. Scientific deficit is only likely to help perpetuate these adverse conditions.

  9. Soil carbon inventories and d 13C along a moisture gradient in Botswana

    NARCIS (Netherlands)

    Bird, M.I.; Veenendaal, E.M.; Lloyd, J.

    2004-01-01

    We present a study of soil organic carbon (SOC) inventories and d 13C values for 625 soil cores collected from well-drained, coarse-textured soils in eight areas along a 1000 km moisture gradient from Southern Botswana, north into southern Zambia. The spatial distribution of trees and grass in the

  10. Influence of Soil Type and Drainage on Growth of Swamp Chestnut Oak (Quercus Michauxii Nutt.) Seedlings

    Science.gov (United States)

    Donald D. Hook

    1969-01-01

    Swamp chestnut oak (Quercus michauxii Nutt.) seedlings were grown for 2 years in five soil types in drained and undrained pots. First-year height growth was related to soil type and pot drainage, but second-year height growth was related only to soil type. Results suggest that swamp chestnut oak is site-sensitive. But slow growth, a maximum of 2...

  11. Drain Insertion in Chronic Subdural Hematoma: An International Survey of Practice.

    Science.gov (United States)

    Soleman, Jehuda; Kamenova, Maria; Lutz, Katharina; Guzman, Raphael; Fandino, Javier; Mariani, Luigi

    2017-08-01

    To investigate whether, after the publication of grade I evidence that it reduces recurrence rates, the practice of drain insertion after burr-hole drainage of chronic subdural hematoma has changed. Further, we aimed to document various practice modalities concerning the insertion of a drain adopted by neurosurgeons internationally. We administered a survey to neurosurgeons worldwide with questions relating to the surgical treatment of chronic subdural hematoma, with an emphasis on their practices concerning the use of a drain. The preferred surgical technique was burr-hole drainage (89%). Most surgeons prefer to place a drain (80%), whereas in 56% of the cases the reason for not placing a drain was brain expansion after evacuation. Subdural drains are placed by 50% and subperiosteal drains by 27% of the responders, whereas 23% place primarily a subdural drain if possible and otherwise a subperiosteal drain. Three quarters of the responders leave the drain for 48 hours and give prophylactic antibiotic treatment, mostly a single-shot dose intraoperatively (70%). Routine postoperative computed tomography is done by 59% mostly within 24-48 hours after surgery (94%). Adjunct treatment to surgery rarely is used (4%). The publication of grade I evidence in favor of drain use influenced positively this practice worldwide. Some surgeons are still reluctant to insert a drain, especially when the subdural space is narrow after drainage of the hematoma. The insertion of a subperiosteal drain could be a good alternative solution. However, its outcome and efficacy must be evaluated in larger studies. Copyright © 2017 Elsevier Inc. All rights reserved.

  12. Rapid breakthrough of pesticides via biopres into tile drains and shallow groundwater: a combined experimental and model study

    Science.gov (United States)

    Klaus, J.; Zehe, E.; Palm, J.; Schroeder, B.

    2009-04-01

    Preferential flow in macropores is a key process which strongly affects infiltration and may cause rapid transport of pesticides into depths of 80 to 150 cm. At these depths they experience a much slower degradation, may leach into shallow groundwater or enter a tile-drain and are transported in surface water bodies. Therefore, preferential transport is an environ¬mental problem because the topsoil is bypassed, which has been originally thought to act as a filter to protect the subsoil and shallow groundwater. To get a better insight in the process of pesticide transport in agricultural soils an irrigation experiment was performed on a 400 m² field site. The experimental plot is located in the Weiherbach valley, south-west Germany, which basic geology consists of Loess and Keuper layers, the soil at the test site is a gleyic Colluvisol. The distance of the irrigation site to the Weiherbach brook is aprox. 12 m, the field is drained with a tile-drain in about 1.2 m depth and the shows runoff over the entire year. Three hours before the irrigation started the farmer applied a pesticide solution consisting of Isoproturon and Flufenacet according to conventional agricultural practice. The irrigation took place in three time blocks (80 min, 60 min, 80 min) and had a total irrigation rate of 33.6 mm measured with ten precipitation samplers. During the first block a tracer solution of 1600 g Bromide and 2000 g Brilliant Blue was irrigated on the test site. The drainage outlet was instrumented with a pressure probe to measure the water level. About 50 water samples were taken on the day of the experiment from the drainage outlet by hand, and in an eight hour interval for six days with an automatic sample procedure. Discharge at the drainage outlet showed two peaks in response irrigation. The breakthrough of the tracer into the brook is much faster then the reaction of the discharge on the precipitation impulse. To gain insight in the vertical transport behaviour three

  13. Brain drain and health workforce distortions in Mozambique.

    Science.gov (United States)

    Sherr, Kenneth; Mussa, Antonio; Chilundo, Baltazar; Gimbel, Sarah; Pfeiffer, James; Hagopian, Amy; Gloyd, Stephen

    2012-01-01

    Trained human resources are fundamental for well-functioning health systems, and the lack of health workers undermines public sector capacity to meet population health needs. While external brain drain from low and middle-income countries is well described, there is little understanding of the degree of internal brain drain, and how increases in health sector funding through global health initiatives may contribute to the outflow of health workers from the public sector to donor agencies, non-governmental organisations (NGOs), and the private sector. An observational study was conducted to estimate the degree of internal and external brain drain among Mozambican nationals qualifying from domestic and foreign medical schools between 1980-2006. Data were collected 26-months apart in 2008 and 2010, and included current employment status, employer, geographic location of employment, and main work duties. Of 723 qualifying physicians between 1980-2006, 95.9% (693) were working full-time, including 71.1% (493) as clinicians, 20.5% (142) as health system managers, and 6.9% (48) as researchers/professors. 25.5% (181) of the sample had left the public sector, of which 62.4% (113) continued working in-country and 37.6% (68) emigrated from Mozambique. Of those cases of internal migration, 66.4% (75) worked for NGOs, 21.2% (24) for donor agencies, and 12.4% (14) in the private sector. Annual incidence of physician migration was estimated to be 3.7%, predominately to work in the growing NGO sector. An estimated 36.3% (41/113) of internal migration cases had previously held senior-level management positions in the public sector. Internal migration is an important contributor to capital flight from the public sector, accounting for more cases of physician loss than external migration in Mozambique. Given the urgent need to strengthen public sector health systems, frank reflection by donors and NGOs is needed to assess how hiring practices may undermine the very systems they seek

  14. Greenhouse gases emission from the sewage draining rivers.

    Science.gov (United States)

    Hu, Beibei; Wang, Dongqi; Zhou, Jun; Meng, Weiqing; Li, Chongwei; Sun, Zongbin; Guo, Xin; Wang, Zhongliang

    2018-01-15

    Carbon dioxide (CO 2 ), methane (CH 4 ) and nitrous oxide (N 2 O) concentration, saturation and fluxes in rivers (Beitang drainage river, Dagu drainage rive, Duliujianhe river, Yongdingxinhe river and Nanyunhe river) of Tianjin city (Haihe watershed) were investigated during July and October in 2014, and January and April in 2015 by static headspace gas chromatography method and the two-layer model of diffusive gas exchange. The influence of environmental variables on greenhouse gases (GHGs) concentration under the disturbance of anthropogenic activities was discussed by Spearman correlative analysis and multiple stepwise regression analysis. The results showed that the concentration and fluxes of CO 2 , CH 4 and N 2 O were seasonally variable with >winter>fall>summer, spring>summer>winter>fall and summer>spring>winter>fall for concentrations and spring>summer>fall>winter, spring>summer>winter>fall and summer>spring>fall>winter for fluxes respectively. The GHGs concentration and saturation were higher in comprehensively polluted river sites and lower in lightly polluted river sites. The three GHGs emission fluxes in two sewage draining rivers of Tianjin were clearly higher than those of other rivers (natural rivers) and the spatial variation of CH 4 was more obvious than the others. CO 2 and N 2 O air-water interface emission fluxes of the sewage draining rivers in four seasons were about 1.20-2.41 times and 1.13-3.12 times of those in the natural rivers. The CH 4 emission fluxes of the sewage draining rivers were 3.09 times in fall to 10.87 times in spring of those in the natural rivers in different season. The wind speed, water temperature and air temperature were related to GHGs concentrations. Nitrate and nitrite (NO 3 - +NO 2 - -N) and ammonia (NH 4 + -N) were positively correlated with CO 2 concentration and CH 4 concentration; and dissolved oxygen (DO) concentration was negatively correlated with CH 4 concentration and N 2 O concentration. The effect of

  15. Brain drain and health workforce distortions in Mozambique.

    Directory of Open Access Journals (Sweden)

    Kenneth Sherr

    Full Text Available Trained human resources are fundamental for well-functioning health systems, and the lack of health workers undermines public sector capacity to meet population health needs. While external brain drain from low and middle-income countries is well described, there is little understanding of the degree of internal brain drain, and how increases in health sector funding through global health initiatives may contribute to the outflow of health workers from the public sector to donor agencies, non-governmental organisations (NGOs, and the private sector.An observational study was conducted to estimate the degree of internal and external brain drain among Mozambican nationals qualifying from domestic and foreign medical schools between 1980-2006. Data were collected 26-months apart in 2008 and 2010, and included current employment status, employer, geographic location of employment, and main work duties.Of 723 qualifying physicians between 1980-2006, 95.9% (693 were working full-time, including 71.1% (493 as clinicians, 20.5% (142 as health system managers, and 6.9% (48 as researchers/professors. 25.5% (181 of the sample had left the public sector, of which 62.4% (113 continued working in-country and 37.6% (68 emigrated from Mozambique. Of those cases of internal migration, 66.4% (75 worked for NGOs, 21.2% (24 for donor agencies, and 12.4% (14 in the private sector. Annual incidence of physician migration was estimated to be 3.7%, predominately to work in the growing NGO sector. An estimated 36.3% (41/113 of internal migration cases had previously held senior-level management positions in the public sector.Internal migration is an important contributor to capital flight from the public sector, accounting for more cases of physician loss than external migration in Mozambique. Given the urgent need to strengthen public sector health systems, frank reflection by donors and NGOs is needed to assess how hiring practices may undermine the very systems they

  16. Effect of an intervention in storm drains to prevent Aedes aegypti reproduction in Salvador, Brazil.

    Science.gov (United States)

    Souza, Raquel Lima; Mugabe, Vánio André; Paploski, Igor Adolfo Dexheimer; Rodrigues, Moreno S; Moreira, Patrícia Sousa Dos Santos; Nascimento, Leile Camila Jacob; Roundy, Christopher Michael; Weaver, Scott C; Reis, Mitermayer Galvão; Kitron, Uriel; Ribeiro, Guilherme Sousa

    2017-07-11

    Aedes aegypti, the principal vector for dengue, chikungunya and Zika viruses, is a synanthropic species that uses stagnant water to complete its reproductive cycle. In urban settings, rainfall water draining structures, such as storm drains, may retain water and serve as a larval development site for Aedes spp. reproduction. Herein, we describe the effect of a community-based intervention on preventing standing water accumulation in storm drains and their consequent infestation by adult and immature Ae. aegypti and other mosquitoes. Between April and May of 2016, local residents association of Salvador, Brazil, after being informed of water accumulation and Ae. aegypti infestation in the storm drains in their area, performed an intervention on 52 storm drains. The intervention consisted of placing concrete at the bottom of the storm drains to elevate their base to the level of the outflow tube, avoiding water accumulation, and placement of a metal mesh covering the outflow tube to avoid its clogging with debris. To determine the impact of the intervention, we compared the frequency at which the 52 storm drains contained water, as well as adult and immature mosquitoes using data from two surveys performed before and two surveys performed after the intervention. During the pre-intervention period, water accumulated in 48 (92.3%) of the storm drains, and immature Ae. aegypti were found in 11 (21.2%) and adults in 10 (19.2%). After the intervention, water accumulated in 5 (9.6%) of the storm drains (P Aedes mosquitoes (mainly Culex spp.) in the storm drains also decreased after the intervention. This study exemplifies how a simple intervention targeting storm drains can result in a major reduction of water retention, and, consequently, impact Ae. aegypti larval populations. Larger and multi-center evaluations are needed to confirm the potential of citywide structural modifications of storm drains to reduce Aedes spp. infestation level.

  17. Brain drain in globalization A general equilibrium analysis from the sending countries’ perspective

    OpenAIRE

    Luca MARCHIORI; I-Ling SHEN; Frederic DOCQUIER

    2009-01-01

    The paper assesses the global effects of brain drain on developing economies and quantifies the relative sizes of various static and dynamic impacts. By constructing a unified generic framework characterized by overlapping generations dynamics and calibrated to real data, this study incorporates many direct impacts of brain drain whose interactions, along with other indirect effects, are endogenously and dynamically generated. Our findings suggest that the short-run impact of brain drain on r...

  18. Stress corrosion on austenitic stainless steels components after sodium draining

    International Nuclear Information System (INIS)

    Champeix, L.; Baque, P.; Chairat, C.

    1980-04-01

    The damage study performed on 316 pipes of a loop after two leakages allows to conclude that a stress corrosion process in sodium hydroxide environment has induced trans-crystaline cracks. The research of conditions inducing such a phenomenon is developed, including parametric tests under uniaxial load and some tests on pipe with welded joints. In aqueous sodium hydroxide, two corrosion processes have been revealed: a general oxidization increasing with environment aeration and a transcrystalline cracking appearing for stresses of the order of yield strength. Other conditions such a temperature (upper than 100 0 C) and time exposures (some tens of hours) are necessary. Cautions in order to limit introduction of wet air into drained loop and a choice of appropriate preheating conditions when restarting the installation must permit to avoid such a type of incident

  19. Brain drain: a challenge to global mental health.

    Science.gov (United States)

    Oladeji, Bibilola D; Gureje, Oye

    2016-08-01

    The brain drain of medical professionals from lower-income to higher-income countries contributes to the current inequity that characterises access to mental healthcare by those in need across the world and hinders efforts to scale up mental health services in resource-constrained settings, especially in Nigeria and other West African countries. The migration of skilled workers is driven by a combination of the globalisation of the labour market and the ability of highly resourced countries to attract and retain specialists from poorer countries. If we are to ameliorate the worldwide shortage of mental health professionals, we need to find innovative ways of attracting young doctors into psychiatric training in all countries. We must also introduce measures to improve health worker retention in low- and middle-income countries.

  20. Reducing resin use in floor drain processing system

    International Nuclear Information System (INIS)

    Flint, W.; Hobart, S.A.; Miller, A.D.

    1995-01-01

    The Kewaunee Nuclear Power Plant utilizes two mixed bed demineralizers for processing floor drain wastes. These demineralizers were originally designed for stream generator blowdown treatment, but were not needed for that purpose. Effluent from the resin beds is monitored for radioactivity and released for discharge. Plant radwaste inleakage volumes and resin disposal volumes were low in comparison with industry averages, but decontamination factors through the treatment system were less than desirable. Release criteria for discharges always had been met, but plant personnel wished to decrease their already low discharges of radioactive species, reduce their resin disposal costs, and provide a margin of safety in the unlikely event that fuel damage would be experienced during an operating cycle. This paper describes the study initiated to address those issues, the findings of the study, and results of implementing some of the study recommendations

  1. Nuclear power plant laundry drain treatment using membrane bio reactor

    International Nuclear Information System (INIS)

    Tsukamoto, Masaaki; Kohanawa, Osamu; Kinugasa, Atsushi; Ogawa, Naoki; Murogaki, Kenta

    2012-01-01

    In nuclear power plant, the radioactive effluent generated by washing the clothes worn in controlled area and the hand and shower water used at the controlled area are treated in laundry drain treatment system. Although various systems which treat such liquid waste preexist, the traditional treatment system has disadvantages such as high running cost and a large amount of secondary waste generation. To solve these matters, we have considered application of an activated sludge system, membrane bio reactor, which has been practically used in general industry. For nuclear power plant, the activated sludge system has been developed, tested in its adaptability and the adequacy has been proved. Some preexisting treatment systems have been replaced with this activated sludge system for the first time in a domestic nuclear power plant, and the renewal system is now in operation. The result is reported. (author)

  2. Drained coastal peatlands: A potential nitrogen source to marine ecosystems under prolonged drought and heavy storm events-A microcosm experiment.

    Science.gov (United States)

    Wang, Hongjun; Richardson, Curtis J; Ho, Mengchi; Flanagan, Neal

    2016-10-01

    Over the past several decades there has been a massive increase in coastal eutrophication, which is often caused by increased runoff input of nitrogen from landscape alterations. Peatlands, covering 3% of land area, have stored about 12-21% of global soil organic nitrogen (12-20Pg N) around rivers, lakes and coasts over millennia and are now often drained and farmed. Their huge nitrogen pools may be released by intensified climate driven hydrologic events-prolonged droughts followed by heavy storms-and later transported to marine ecosystems. In this study, we collected peat monoliths from drained, natural, and restored coastal peatlands in the Southeastern U.S., and conducted a microcosm experiment simulating coupled prolonged-drought and storm events to (1) test whether storms could trigger a pulse of nitrogen export from drought-stressed peatlands and (2) assess how differentially hydrologic managements through shifting plant communities affect nitrogen export by combining an experiment of nitrogen release from litter. During the drought phase, we observed a significant temporal variation in net nitrogen mineralization rate (NMR). NMR spiked in the third month and then decreased rapidly. This pattern indicates that drought duration significantly affects nitrogen mineralization in peat. NMR in the drained site reached up to 490±110kgha(-1)year(-1), about 5 times higher than in the restored site. After the 14-month drought phase, we simulated a heavy storm by bringing peat monoliths to saturation. In the discharge waters, concentrations of total dissolved nitrogen in the monoliths from the drained site (72.7±16.3mgL(-1)) was about ten times as high as from the restored site. Our results indicate that previously drained peatlands under prolonged drought are a potent source of nitrogen export. Moreover, drought-induced plant community shifts to herbaceous plants substantially raise nitrogen release with lasting effects by altering litter quality in peatlands

  3. CSER 94-011: Use of glovebags for demister draining operations

    International Nuclear Information System (INIS)

    Hess, A.L.

    1994-01-01

    A criticality safety review is presented for the use of plastic-sheet glovebags for the operations of draining demisters on the 26-inch vacuum system headers. A criticality drain is required because of the possibility for spilling liquid of sufficient volume and fissile content for criticality. It is recommended that the glovebag design include a rigid, 2ft x 2ft floor with a central drain feeding a geometrically favorable spill-catch vessel, plus a screen grid above the bottom for drain protection

  4. Estimation of local and regional components of drain - flow from an irrigated field

    International Nuclear Information System (INIS)

    Eching, S.O.; Hopmans, J.W.; Wallender, W.W.; Macyntyre, J.L.; Peters, D.

    1995-01-01

    The contribution of regional ground water and deep percolation from a furrow irrigated field to total drain flow was estimated using salt load analysis. It was found that 64% of the drain flow comes from regional ground water flow. The electrical conductivity of the drain water was highly correlated with the drain flow rate. From the field water balance with deep percolation as estimated from the salt load analysis, using yield function derived evapotranspiration, and measured changes in root zone water storage, it was shown that 14% of the crop evapotranspiration comes from ground water during the study period. 8 figs; 5 tabs; 15 refs ( Author )

  5. Remaining Sites Verification Package for the 331 Life Sciences Laboratory Drain Field Septic System. Attachment to Waste Site Reclassification Form 2008-020

    International Nuclear Information System (INIS)

    Capron, J.M.

    2008-01-01

    The 331 Life Sciences Laboratory Drain Field (LSLDF) septic system waste site consists of a diversion chamber, two septic tanks, a distribution box, and a drain field. This septic system was designed to receive sanitary waste water, from animal studies conducted in the 331-A and 331-B Buildings, for discharge into the soil column. However, field observations and testing suggest the 331 LSLDF septic system did not receive any discharges. In accordance with this evaluation, the confirmatory sampling results support a reclassification of the 331 LSLDF waste site to No Action. This site does not have a deep zone or other condition that would warrant an institutional control in accordance with the 300-FF-2 ROD under the industrial land use scenario

  6. Icelandic Inland Wetlands: Characteristics and Extent of Draining

    OpenAIRE

    Gudmundsson, Jon; Brink, Sigmundur H.; Arnalds, Olafur; Gisladottir, Fanney O.; Oskarsson, Hlynur

    2016-01-01

    Iceland has inland wetland areas with soils exhibiting both Andosol and Histosol properties which are uncommon elsewhere on Earth. They are generally fertile, with higher bird-nest densities than in similar wetlands in the neighboring countries, with nutrients released by rapid weathering of aeolian materials of basaltic nature. Icelandic inland wetlands cover about 9000 km2 constituting 19.4 % of the vegetated surfaces of the island. The wetland soils are often 1–3 m thick and store 33 to >1...

  7. The hudiara drain wastewater effect on the distribution of surrounding herbaceous vegetation

    Energy Technology Data Exchange (ETDEWEB)

    Shah, F R; Ahmad, N; Zahid, D M; Masood, K R; Ahmad, S.S., E-mail: dinmuhammadzahid@bzu.edu.p

    2010-06-15

    In this study, phytosociological survey using Braun-Blanquet's approach was undertaken to investigate the Hudiara drain wastewater influence on the surrounding vegetation. A total of 99 quadrats were laid to identify the plant species and altogether 66 species were recorded. Multivariate analysis of vegetation data (using CANOCO 4.5. software) classified the vegetation into two major communities including Cynodon dactylon, Boerhaavia diffusa, Parthenium hysterphorus and Xanthium strumarium groups. The presence of these species designated the area as waste land strongly supporting the growth of such species. The pattern of floral diversity was also not uniform and exhibited considerable variation. Canonical Correspondence Analysis revealed that the distribution of vegetation has correlation with environmental variables, but their role in the grouping of species remained non significant. However, soil EC played some role in the grouping of Stellaria media and Fagonia cretic. Similarly, some species viz., Ricinus communis, Boerhaavia diffusa and Phragmites karka showed a correlation with Fe and Cr respectively, suggesting Phragmites karka as a suitable candidate for chromium contaminated sites. (author)

  8. The hudiara drain wastewater effect on the distribution of surrounding herbaceous vegetation

    International Nuclear Information System (INIS)

    Shah, F.R.; Ahmad, N.; Zahid, D.M.; Masood, K.R.; Ahmad, S.S.

    2010-01-01

    In this study, phytosociological survey using Braun-Blanquet's approach was undertaken to investigate the Hudiara drain wastewater influence on the surrounding vegetation. A total of 99 quadrats were laid to identify the plant species and altogether 66 species were recorded. Multivariate analysis of vegetation data (using CANOCO 4.5. software) classified the vegetation into two major communities including Cynodon dactylon, Boerhaavia diffusa, Parthenium hysterphorus and Xanthium strumarium groups. The presence of these species designated the area as waste land strongly supporting the growth of such species. The pattern of floral diversity was also not uniform and exhibited considerable variation. Canonical Correspondence Analysis revealed that the distribution of vegetation has correlation with environmental variables, but their role in the grouping of species remained non significant. However, soil EC played some role in the grouping of Stellaria media and Fagonia cretic. Similarly, some species viz., Ricinus communis, Boerhaavia diffusa and Phragmites karka showed a correlation with Fe and Cr respectively, suggesting Phragmites karka as a suitable candidate for chromium contaminated sites. (author)

  9. Characterizing phosphorus dynamics in tile-drained agricultural fieldsof eastern Wisconsin

    Science.gov (United States)

    Madison, Allison; Ruark, Matthew; Stuntebeck, Todd D.; Komiskey, Matthew J.; Good, Laura W.; Drummy, Nancy; Cooley, Eric

    2014-01-01

    Artificial subsurface drainage provides an avenue for the rapid transfer of phosphorus (P) from agricultural fields to surface waters. This is of particular interest in eastern Wisconsin, where there is a concentrated population of dairy farms and high clay content soils prone to macropore development. Through collaboration with private landowners, surface and tile drainage was measured and analyzed for dissolved reactive P (DRP) and total P (TP) losses at four field sites in eastern Wisconsin between 2005 and 2009. These sites, which received frequent manure applications, represent a range of crop management practices which include: two chisel plowed corn fields (CP1, CP2), a no-till corn–soybean field (NT), and a grazed pasture (GP). Subsurface drainage was the dominant pathway of water loss at each site accounting for 66–96% of total water discharge. Average annual flow-weighted (FW) TP concentrations were 0.88, 0.57, 0.21, and 1.32 mg L−1 for sites CP1, CP2, NT, and GP, respectively. Low TP concentrations at the NT site were due to tile drain interception of groundwater flow where large volumes of tile drainage water diluted the FW-TP concentrations. Subsurface pathways contributed between 17% and 41% of the TP loss across sites. On a drainage event basis, total drainage explained between 36% and 72% of the event DRP loads across CP1, CP2, and GP; there was no relationship between event drainflow and event DRP load at the NT site. Manure applications did not consistently increase P concentrations in drainflow, but annual FW-P concentrations were greater in years receiving manure applications compared to years without manure application. Based on these field measures, P losses from tile drainage must be integrated into field level P budgets and P loss calculations on heavily manured soils, while also acknowledging the unique drainage patterns observed in eastern Wisconsin.

  10. Soil Phosphorus Compositional Characteristics as a Function of Land-Use Practice in the Upper Eau Galle River Watershed, Wisconsin

    National Research Council Canada - National Science Library

    James, William F; Eakin, Harry L; Ruiz, Carlos E; Barko, John W

    2004-01-01

    The purpose of this research was to quantify biologically labile and refractory phosphorus species in source soils of an agricultural watershed that drains into a eutrophic Corps of Engineers reservoir...

  11. Draining Water from Aircraft Fuel Using Nitrogen Enriched Air

    Directory of Open Access Journals (Sweden)

    Michael Frank

    2018-04-01

    Full Text Available This paper concerns a computational study of the process of removing water from an aircraft’s fuel tank by pumping nitrogen enriched air (NEA from the bottom of the tank. This is an important procedure for the smooth, efficient, and safe operation of the aircraft’s engine. Due to the low partial pressure of water in the pumped NEA, it absorbs water from the fuel. The water-laden bubbles enter the ullage, the empty space above the fuel, and escape into the environment. The effects of the number of NEA inlets and the NEA mass flow rate on the timescale of the NEA pumping were investigated using Computational Fluid Dynamics. The results reveal that the absorption of water by the NEA bubbles is low and is not affected by the number of the inlets used. Yet, the water content in the fuel decreases fast during the procedure, which is the desired outcome. We show that this is due to the relatively dry NEA entering the ullage and displacing the moist air, thus reducing the partial pressure of water at the fuel/ullage interface. This shift from equilibrium conditions forces water to evaporate from the fuel’s entire surface. Furthermore, the amount of water migrating from the fuel directly into the ullage is significantly greater than that absorbed by the rising bubbles. In turn, the rate of decrease of the water content in the ullage is determined by the total NEA mass flow rate and this is the dominant contributor to the draining time, with the number of NEA nozzles playing a minor role. We confirmed this by pumping NEA directly into the ullage, where we observe a significant decrease of water even when the NEA is not pumped through the fuel. We also show that doubling the mass flow rate halves the draining time. When considering the capability of most modern aircraft to pump NEA through the fuel as part of their inerting system, the proposed method for removing water is particularly attractive, requiring very little (if at all design modification.

  12. Management of Chest Drains: A National Survey on Surgeons‑in ...

    African Journals Online (AJOL)

    triangle of safety [Figure 1]. Just above a quarter of respondents (27.2%) always utilized different sizes of tubes for different pathologies and the same proportion of respondents always positioned the tip of the tube apically to drain pneumothorax and basally to drain pleural effusion. In contrast, 9.9% and 6.2% of respondents.

  13. Controlling the ambipolarity and improvement of RF performance using Gaussian Drain Doped TFET

    Science.gov (United States)

    Nigam, Kaushal; Gupta, Sarthak; Pandey, Sunil; Kondekar, P. N.; Sharma, Dheeraj

    2018-05-01

    Ambipolar conduction in tunnel field-effect transistors (TFETs) has been occurred as an inherent issue due to drain-channel tunneling. It makes TFET less efficient and restricts its application in complementary digital circuits. Therefore, this manuscript reports the application of Gaussian doping profile on nanometer regime silicon channel TFETs to completely eliminate the ambipolarity. For this, Gaussian doping is used in the drain region of conventional gate-drain overlap TFET to control the tunneling of electrons from the valence band of channel to the conduction band of drain. As a result, barrier width at the drain/channel junction increases significantly leading to the suppression of an ambipolar current even when higher doping concentration (1 ? 10 ? cm ?) is considered in the drain region. However, significant improvement in terms of RF figure-of-merits such as cut-off frequency (f ?), gain bandwidth product (GBW), and gate-to-drain capacitance (C ?) is achieved with Gaussian doped gate on drain overlap TFET as compared to its counterpart TFET.

  14. 77 FR 30886 - Virginia Graeme Baker Pool and Spa Safety Act; Interpretation of Unblockable Drain

    Science.gov (United States)

    2012-05-24

    ... interpretation and installed unblockable drain covers and now would have to go back and ``re-do'' their work... compliance and whether the pool operator is seeking a plan review and not just limited advice about how to... secondary anti-entrapment system to come into compliance, unless the pool uses a gravity drain system or the...

  15. Laparoscopic elective cholecystectomy with and without drain: A controlled randomised trial

    Directory of Open Access Journals (Sweden)

    Gouda El-labban

    2012-01-01

    Full Text Available Background : Laparoscopic cholecystectomy is the main method of treatment of symptomatic gallstones. Routine drainage after laparoscopic cholecystectomy is an issue of considerable debate. Therefore, a controlled randomised trial was designed to assess the value of drains in elective laparoscopic cholecystectomy. Materials and Methods: During a two-year period (From April 2008 to January 2010, 80 patients were simply randomised to have a drain placed (group A, an 8-mm pentose tube drain was retained below the liver bed, whereas 80 patients were randomised not to have a drain (group B placed in the subhepatic space. End points of this trial were to detect any differences in morbidity, postoperative pain, wound infection and hospital stay between the two groups. Results : There was no mortality in either group and no statistically significant difference in postoperative pain, nausea and vomiting, wound infection or abdominal collection between the two groups. However, hospital stay was longer in the drain group than in group without drain and it is appearing that the use of drain delays hospital discharge. Conclusion : The routine use of a drain in non-complicated laparoscopic cholecystectomy has nothing to offer; in contrast, it is associated with longer hospital stay.

  16. Drain Tube-Induced Jejunal Penetration Masquerading as Bile Leak following Whipple's Operation.

    Science.gov (United States)

    Bae, Sang Ho; Lee, Tae Hoon; Lee, Sae Hwan; Lee, Suck-Ho; Park, Sang-Heum; Kim, Sun-Joo; Kim, Chang Ho

    2011-05-01

    A 70-year-old man had undergone pancreaticoduodenectomy due to a distal common bile duct malignancy. After the operation, serous fluid discharge decreased from two drain tubes in the retroperitoneum. Over four weeks, the appearance of the serous fluid changed to a greenish bile color and the patient persistently drained over 300 ml/day. Viewed as bile leak at the choledochojejunostomy, treatment called for endoscopic diagnosis and therapy. Cap-fitted forward-viewing endoscopy demonstrated that the distal tip of a pancreatic drain catheter inserted at the pancreaticojejunostomy site had penetrated the opposite jejunum wall. One of the drain tubes primarily placed in the retroperitoneum had also penetrated the jejunum wall, with the distal tip positioned near the choledochojejunostomy site. No leak of contrast appeared beyond the jejunum or anastomosis site. Following repositioning of a penetrating catheter of the pancreaticojejunostomy, four days later, the patient underwent removal of two drain tubes without additional complications. In conclusion, the distal tip of the catheter, placed to drain pancreatic juice, penetrated the jejunum wall and may have caused localized perijejunal inflammation. The other drain tube, placed in the retroperitoneal space, might then have penetrated the inflamed wall of the jejunum, allowing persistent bile drainage via the drain tube. The results masqueraded as bile leakage following pancreaticoduodenectomy.

  17. Nurses’ knowledge of care of chest drain: A survey in a Nigerian semiurban university hospital

    Science.gov (United States)

    Kesieme, Emeka Blessius; Essu, Ifeanyichukwu Stanley; Arekhandia, Bruno Jeneru; Welcker, Katrin; Prisadov, Georgi

    2016-01-01

    Background/Objective: Inefficient nursing care of chest drains may associated with unacceptable and sometimes life-threatening complications. This report aims to ascertain the level of knowledge of care of chest drains among nurses working in wards in a teaching hospital in Nigeria. Methods: A cross-sectional study among nurses at teaching hospital using pretested self-administered questionnaires. Results: The majority were respondents aged between 31 and 40 years (45.4%) and those who have nursing experience between 6 and 10 years. Only 37 respondents (26.2%) had a good knowledge of nursing care of chest drains. Knowledge was relatively higher among nurses who cared for chest drains daily, nurses who have a work experience of 0.05). Performance was poor on the questions on position of drainage system were not statistically significant with relationship to waist level while mobilizing the patient, application of suction to chest drains, daily changing of dressing over chest drain insertion site, milking of tubes and drainage system with dependent loop. Conclusion: The knowledge of care of chest drains among nurses is poor, especially in the key post procedural care. There is an urgent need to train them so as to improve the nursing care of patients managed with chest drains. PMID:26857934

  18. Drain Tube-Induced Jejunal Penetration Masquerading as Bile Leak following Whipple’s Operation

    Directory of Open Access Journals (Sweden)

    Sang Ho Bae

    2011-05-01

    Full Text Available A 70-year-old man had undergone pancreaticoduodenectomy due to a distal common bile duct malignancy. After the operation, serous fluid discharge decreased from two drain tubes in the retroperitoneum. Over four weeks, the appearance of the serous fluid changed to a greenish bile color and the patient persistently drained over 300 ml/day. Viewed as bile leak at the choledochojejunostomy, treatment called for endoscopic diagnosis and therapy. Cap-fitted forward-viewing endoscopy demonstrated that the distal tip of a pancreatic drain catheter inserted at the pancreaticojejunostomy site had penetrated the opposite jejunum wall. One of the drain tubes primarily placed in the retroperitoneum had also penetrated the jejunum wall, with the distal tip positioned near the choledochojejunostomy site. No leak of contrast appeared beyond the jejunum or anastomosis site. Following repositioning of a penetrating catheter of the pancreaticojejunostomy, four days later, the patient underwent removal of two drain tubes without additional complications. In conclusion, the distal tip of the catheter, placed to drain pancreatic juice, penetrated the jejunum wall and may have caused localized perijejunal inflammation. The other drain tube, placed in the retroperitoneal space, might then have penetrated the inflamed wall of the jejunum, allowing persistent bile drainage via the drain tube. The results masqueraded as bile leakage following pancreaticoduodenectomy.

  19. Influence of landscape position and transient water table on soil development and carbon distribution in a steep, headwater catchment

    Science.gov (United States)

    Scott W. Bailey; Patricia A. Brousseau; Kevin J. McGuire; Donald S. Ross

    2014-01-01

    Upland headwater catchments, such as those in the AppalachianMountain region, are typified by coarse textured soils, flashy hydrologic response, and low baseflow of streams, suggesting well drained soils and minimal groundwater storage. Model formulations of soil genesis, nutrient cycling, critical loads and rainfall/runoff response are typically based on vertical...

  20. A mathematical model to optimize the drain phase in gravity-based peritoneal dialysis systems.

    Science.gov (United States)

    Akonur, Alp; Lo, Ying-Cheng; Cizman, Borut

    2010-01-01

    Use of patient-specific drain-phase parameters has previously been suggested to improve peritoneal dialysis (PD) adequacy. Improving management of the drain period may also help to minimize intraperitoneal volume (IPV). A typical gravity-based drain profile consists of a relatively constant initial fast-flow period, followed by a transition period and a decaying slow-flow period. That profile was modeled using the equation VD(t) = (V(D0) - Q(MAX) x t) xphi + (V(D0) x e(-alphat)) x (1 - phi), where V(D)(t) is the time-dependent dialysate volume; V(D0), the dialysate volume at the start of the drain; Q(MAX), the maximum drain flow rate; alpha, the exponential drain constant; and phi, the unit step function with respect to the flow transition. We simulated the effects of the assumed patient-specific maximum drain flow (Q(MAX)) and transition volume (psi), and the peritoneal volume percentage when transition occurs,for fixed device-specific drain parameters. Average patient transport parameters were assumed during 5-exchange therapy with 10 L of PD solution. Changes in therapy performance strongly depended on the drain parameters. Comparing 400 mL/85% with 200 mL/65% (Q(MAX/psi), drain time (7.5 min vs. 13.5 min) and IPV (2769 mL vs. 2355 mL) increased when the initial drain flow was low and the transition quick. Ultrafiltration and solute clearances remained relatively similar. Such differences were augmented up to a drain time of 22 minutes and an IPV of more than 3 L when Q(MAX) was 100 mL/min. The ability to model individual drain conditions together with water and solute transport may help to prevent patient discomfort with gravity-based PD. However, it is essential to note that practical difficulties such as displaced catheters and obstructed flow paths cause variability in drain characteristics even for the same patient, limiting the clinical applicability of this model.

  1. Sensitivity Analysis of the Agricultural Policy/Environmental eXtender (APEX) for Phosphorus Loads in Tile-Drained Landscapes.

    Science.gov (United States)

    Ford, W; King, K; Williams, M; Williams, J; Fausey, N

    2015-07-01

    Numerical modeling is an economical and feasible approach for quantifying the effects of best management practices on dissolved reactive phosphorus (DRP) loadings from agricultural fields. However, tools that simulate both surface and subsurface DRP pathways are limited and have not been robustly evaluated in tile-drained landscapes. The objectives of this study were to test the ability of the Agricultural Policy/Environmental eXtender (APEX), a widely used field-scale model, to simulate surface and tile P loadings over management, hydrologic, biologic, tile, and soil gradients and to better understand the behavior of P delivery at the edge-of-field in tile-drained midwestern landscapes. To do this, a global, variance-based sensitivity analysis was performed, and model outputs were compared with measured P loads obtained from 14 surface and subsurface edge-of-field sites across central and northwestern Ohio. Results of the sensitivity analysis showed that response variables for DRP were highly sensitive to coupled interactions between presumed important parameters, suggesting nonlinearity of DRP delivery at the edge-of-field. Comparison of model results to edge-of-field data showcased the ability of APEX to simulate surface and subsurface runoff and the associated DRP loading at monthly to annual timescales; however, some high DRP concentrations and fluxes were not reflected in the model, suggesting the presence of preferential flow. Results from this study provide new insights into baseline tile DRP loadings that exceed thresholds for algal proliferation. Further, negative feedbacks between surface and subsurface DRP delivery suggest caution is needed when implementing DRP-based best management practices designed for a specific flow pathway. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  2. Biodiversity on mire ecosystems and drained peatlands - a basis for environmental peat harvesting; Biologisk maangfald paa myrar och dikad torvmark - underlag foer ett miljoemaessigt torvbruk

    Energy Technology Data Exchange (ETDEWEB)

    Stedingk, Henrik von (Swedish Biodiversity Centre, Uppsala (Sweden))

    2009-07-01

    The interest of peat harvesting has increased, due to the political ambition to reduce greenhouse gas emissions and to increase the use of local energy sources. Peatlands drained for forestry, a common resource in Sweden, can be a good energy source in terms of greenhouse gas emissions, under certain conditions. The question is what consequences increased peat harvesting would have on biodiversity in the forest landscape. To answer this question this literature study was performed to summarize what is known about the life of a natural and drained mire, and to discuss what conservation values could be found on a drained peatland. The definition of mire is a wetland with active peat accumulation, even if mires also are distinguished based on specific plant communities. A mire often contains several mire types. Some mire taxa are specialized for living on mires, other organisms have other main habitats but utilize the mire for fulfilling their life cycle. The level of knowledge varies for different organisms. The best known groups are vascular plants and bryophytes. They are also used for classifying mires since their abundance is related to gradients of pH, fertility and water level. Arthropods is a diverse group on mires favored by open moist forests and water pools. Poor mires with restricted flora may be good insect habitats. Birds are found in habitats rich in insects. Large mires are richer in wader species thanks to higher heterogeneity and a variety of insect habitats. The microscopic life in peat is rich and the species composition differs from the forest soil, even if the level of knowledge is limited. Drainage leads to species turn over for many groups of organisms and drainage often leads to a decrease in diversity. However, drained peatlands is a collective concept including different peatland types in different succession phases and different intensity of drainage. Therefore in general, drained peatlands cannot be treated as less important for

  3. Heterotrophic respiration in drained tropical peat temperatures influenced by shading gradient

    Science.gov (United States)

    Jauhiainen, Jyrki; Kerojoki, Otto; Silvennoinen, Hanna; Limin, Suwido; Vasander, Harri

    2015-04-01

    Lowland peatlands in Southeast Asia constitute a highly concentrated carbon (C) pool of global significance. These peatlands have formed over periods of several millennia by forest vegetation tolerant to flooding and poor substrates. Uncontrollable drainage and reoccurring wild fires in lack of management after removal of forest cover has impaired the C-storing functions in large reclaimed areas. Intergovernmental Panel on Climate Change (IPCC) reporting sees drained tropical organic soils as one of the largest greenhouse gas emissions releasing terrestrial systems. Vast areas of deforested tropical peatlands do not receive noteworthy shading by vegetation, which increases the amount of solar radiation reaching the peat surface. We studied heterotrophic carbon dioxide (CO2), nitrous oxide (N2O) and methane (CH4) fluxes in tropical peat in conditions, where; (i) peat temperatures were modified by artificial shading (no shade, 28%, 51% and 90% from the full sun exposure), (ii) root respiration was minimized, (iii) nutrient availability for peat decomposer community was changed (NPK fertilization of 0 and 313 kg ha-1). The experiment was repeated at two over 20 years ago drained fallow agricultural- and degraded sites in Central Kalimantan, Indonesia. Enhanced shading created a lasting decrease in peat temperatures, and decreased diurnal temperature fluctuations, in comparison to less shaded plots. The largest peat temperature difference was between the unshaded and 90% shaded peat surface, where the average temperatures within the topmost 50-cm peat profile differed 3 °C, and diurnal temperatures at 5 cm depth varied up to 4.2 °C in the unshaded and 0.4 °C in the 90% shaded conditions. Highest impacts on the heterotrophic CO2 fluxes caused by the treatments were on agricultural land, where 90% shading from the full exposure resulted in a 33% lower CO2 emission average on the unfertilised plots and a 66% lower emission average on the fertilised plots. Correlation

  4. Oculo-peritoneal shunt: draining aqueous humor to the peritoneum

    Directory of Open Access Journals (Sweden)

    Ana Maldonado-Junyent

    2015-04-01

    Full Text Available In 2010, there were estimated to be approximately 60.5 million people with glaucoma. This number is expected to increase to 79.6 million by 2020. In 2010, there were 8.4 million people with bilateral blindness caused by glaucoma, and this number is expected in increase to 11.2 million by 2020. Filtering implants are special devices that have been developed to reduce intraocular pressure in patients with refractory glaucoma. The success rate of these implants is relatively low, and they continue to fail over time. To avoid failure caused by the formation of scar tissue around the implants, attempts have been made to drain the aqueous humor to various sites, including the venous system, lacrimal sac, sinuses, and conjunctival fornix. Recently, a system to shunt aqueous humor from the anterior chamber to the peritoneum has been developed. The surgical technique involved in this system is a modification of the technique currently used by neurosurgeons for the treatment of hydrocephalus. We present the first case operated using this technique.

  5. Crud separation from equipment drain of BWR atomic power station

    International Nuclear Information System (INIS)

    Hayashi, Masaru; Yamaguchi, Hisashi; Moriya, Yasuhiro; Koshiba, Yukihiko; Ota, Yoshiharu.

    1977-01-01

    In the primary cooling systems of BWR nuclear power stations, radioactive crud is generated and accumulates in reactors and circulating systems, which causes the radiation exposure of workers at the time of the inspection and maintenance of reactors. The chemical composition and grain size distribution of crud differ largely according to the construction of primary systems, the operational conditions of reactors, and the process of operation. The study on the application of nuclear pore membrane filter NPMF to the separation of crud in the waste water from equipment drain systems has been carried out. With the NPMF, clarified filtrate can be obtained without any filter aid, therefore the secondary waste of filter sludge is not generated. When the filter is clogged, the filtration capability can be regenerated by reverse flow washing, and continuous filtration is possible actually because the regeneration takes only short time. The NPMF is the polycarbonate membrane of about 10 μm thick, to which charged particles are irradiated vertically, and the flight tracks are etched with alkali solution, thus the required pore treatment is applied. The basic investigation of waste liquid, the endurance test of actual filters, the filtration test with the pilot apparatus, the demonstration test with an actual equipment, and the design of the actual equipment have been carried out for three years. (Kako, I.)

  6. Molten salt fueled reactors with a fast salt draining

    International Nuclear Information System (INIS)

    Ventre, Edmond; Blum, J.M.

    1976-01-01

    This invention relates to a molten salt nuclear reactor which comprises a new arrangement for shutting it down in complete safety. This nuclear reactor has a molten salt primary circuit comprising, in particular, the core of this reactor. It includes a leak tight vessel the capacity of which is appreciably greater than that of the molten salt volume of the circuit and placed so that the level of the molten salt, when all the molten salt of the circuit is contained in this vessel, is less than that of the base of the core. There are facilities for establishing and maintaining an inert gas pressure in the vessel above the molten salt, for releasing the compressed gas and for connecting the vessel to the primary circuit entering this vessel at a lower level than that of the molten salt and enabling molten salt to enter or leave the vessel according to the pressure of the inert gas. The particular advantage of this reactor is that it can be shut down safely since the draining of the primary circuit no longer results from a 'positive action' but from the suppression of an arrangement essential for the operation of the reactor consisting of the build-up of the said inert gas pressure in the said vessel [fr

  7. Dynamic Looping of a Free-Draining Polymer

    Energy Technology Data Exchange (ETDEWEB)

    Ye, Felix X. -F.; Stinis, Panos; Qian, Hong

    2018-01-11

    Here, we revisit the celebrated Wilemski--Fixman (WF) treatment for the looping time of a free-draining polymer. The WF theory introduces a sink term into the Fokker--Planck equation for the $3(N+1)$-dimensional Ornstein--Uhlenbeck process of polymer dynamics, which accounts for the appropriate boundary condition due to the formation of a loop. The assumption for WF theory is considerably relaxed. A perturbation method approach is developed that justifies and generalizes the previous results using either a delta sink or a Heaviside sink. For both types of sinks, we show that under the condition of a small dimensionless $\\epsilon$, the ratio of capture radius to the Kuhn length, we are able to systematically produce all known analytical and asymptotic results obtained by other methods. This includes most notably the transition regime between the $N^2$ scaling of Doi, and $N\\sqrt{N}/\\epsilon$ scaling of Szabo, Schulten, and Schulten. The mathematical issue at play is the nonuniform convergence of $\\epsilon\\to 0$ and $N\\to\\infty$, the latter being an inherent part of the theory of a Gaussian polymer. Our analysis yields a novel term in the analytical expression for the looping time with small $\\epsilon$, which was previously unknown. Monte Carlo numerical simulations corroborate the analytical findings. The systematic method developed here can be applied to other systems modeled by multidimensional Smoluchowski equations.

  8. Safety of thyroidectomy and cervical neck dissection without drains

    Science.gov (United States)

    Abboud, Bassam; Sleilaty, Ghassan; Rizk, Habib; Abadjian, Gerard; Ghorra, Claude

    2012-01-01

    Background Many studies have reported that drainage after thyroidectomy does not decrease the rate of local postoperative complications. We sought to review the safety of thyroidectomy combined with cervical neck dissection (CND) without drainage. Methods The medical records of consecutive patients who underwent thyroidectomy without drainage were retrospectively reviewed. Two groups were defined depending on whether CND was or was not performed. The main outcome was identification of patients with cervical bleeding, hematoma or seroma. Results We included 1127 patients (139 who had CND and 988 who did not). Of these, 207 patients (18%) had transient postoperative hypocalcemia, 9 (0.8%) had permanent postoperative hypoparathyroidism, 56 (5%) had transient postoperative hoarseness and 7 (0.6%) had permanent vocal cord paralysis. A total of 44 patients (4%) experienced postoperative hematoma and/or seroma: 8 patients (6%) who had CND and 36 (4%) who did not. There was no major bleeding in the 2 groups; all patients had minor bleeding or seroma not requiring surgical intervention. The postoperative stay in hospital for both groups was 1 day in 92% of patients. Wound infection occurred in 0.8% of all patients: 1 (0.7%) who had CND and 8 (0.8%) who did not. There was no significant difference between the groups in overall perioperative complications or in time of hospital discharge. Conclusion Thyroidectomy without drains is safe and effective, even in combination with CND. PMID:22449723

  9. Draining down of a nuclear steam generating system

    International Nuclear Information System (INIS)

    Jawor, J.C.

    1987-01-01

    The method is described of draining down contained reactor-coolant water from the inverted vertical U-tubes of a vertical-type steam generator in which the upper, inverted U-shaped ends of the tubes are closed and the lower ends thereof are open. The steam generator is part of a nuclear powered steam generating system wherein the reactor coolant water is normally circulated from and back into the reactor via a loop comprising the steam generator and inlet and outlet conduits connected to the lower end of the steam generator. The method comprises continuously introducing a gas which is inert to the system and which is under pressure above atmospheric pressure into at least one of the downwardly facing open ends of each of the U-tubes from below the tube sheet in which the open ends of the U-tubes are mounted adjacent the lower end of the steam generator, while permitting the water to flow out from the open ends of the U-tubes

  10. Reverse brain drain in South Korea: state-led model.

    Science.gov (United States)

    Yoon, B L

    1992-01-01

    Korea's reverse brain drain (RBD) has been an organized government effort, rather than a spontaneous social phenomenon, in that various policies and the political support of President Park, Chung-Hee were instrumental in laying the groundwork for its success. Particular features of Korea's RBD policies are the creation of a conducive domestic environment (i.e., government-sponsored strategic R & D institution-building, legal, and administrative reforms), and importantly, the empowerment of returnees (via, i.e., exceptionally good maternal benefits, guarantees of research autonomy). President Park played the cardinal role in empowering repatriates at the expense of his own civil bureaucracy, and his capacity for such patronage derived from Korea's bureaucratic-authoritarian political system. Returning scientists and engineers directly benefitted from this political system as well as Park's personal guardianship. For Park, empowerment of returning "brains" was necessary to accomplish his national industrialization plan, thereby enhancing his political legitimacy in domestic politics. An alliance with the R & D cadre was functionally necessary to successfully consolidate strong presidential power, and politically nonthreatening due to the particular form of "pact of domination" in Korea's power structure. RBD in Korea will continue in the near future given Korea's drive for high technology, and the remarkable expansion of local industrial and educational sectors. Korea's future RBD, however, needs to pay closer attention to the following 4 problems: research autonomy; equality issues; skill-based repatriation of technicians and engineers rather than Ph.Ds; and subsidies to small and medium industry for RBD.

  11. BRAIN DRAIN IN THE GLOBALIZATION ERA: THE CASE OF ROMANIA

    Directory of Open Access Journals (Sweden)

    MARIANA BĂLAN

    2017-06-01

    Full Text Available Migration is an old phenomenon in the history of humankind. However, the magnitude, complexity, and structure of migration flows in the global era are all unprecedented. According to the United Nations Report “Trends in International Migrant Stock: the 2015 Revision” at world level 244 million international migrants were recorded in 2015. With the increase in the number of migrants, the emigration of ‘high-skilled’ individuals is also growing. OECD and United Nation Statistics show that in the last decade the number of migrants with tertiary education increased by about 70%. Brain drain is also a well-known phenomenon. Highly educated individuals and scientists have travelled the world in all centuries in search of better study and research, and working conditions, and of new opportunities. Nowadays, in the era of globalisation and, implicitly, of swifter development of international markets, the emigration rate of high-skilled experts exceeds the total emigration rate, which shows the selectiveness of migration at educational level. The paper presents a brief analysis of the interdependencies between migration and globalisation and of the effects of globalisation on the migration of high-skilled individuals. The trends, structure, and volume of high-skilled labour force from Romania are analysed along with the effects generated by them.

  12. BRAIN DRAIN – BRAIN GAIN: SLOVAK STUDENTS AT CZECH UNIVERSITIES

    Directory of Open Access Journals (Sweden)

    FISCHER, Jakub

    2015-09-01

    Full Text Available The Slovak Republic is experiencing a growing brain drain of elite secondary school students. Slovak human capital flows chiefly to Czech Higher Education Institutes (HEIs. The aim of this paper is to analyse who these Slovak students are to create a complete profile of Slovak students at Czech HEIs. We used a unique dataset based on the surveys EUROSTUDENT V and DOKTORANDI 2014 to explore differences between Czech and Slovak students, their financial situation and the functionality of the intergenerational transmission mechanism. We have found that Slovak students at Czech HEIs come from highly educated families and from the middle and higher class families significantly more often than Czech students at Czech HEIs or Slovak students at Slovak HEIs. Approximately 80% of them came from grammar schools. Slovak students also often have better language skills. We have discovered that Slovak students at Czech HEIs enjoy certain social benefits, slightly more often they have higher monthly income compared to Czech students, and they work slightly less often during their studies. Finally, according to our findings, Slovak doctoral students are often reluctant to return back to the Slovak Republic or to stay in the Czech Republic.

  13. Criticality safety considerations for MSRE fuel drain tank uranium aggregation

    International Nuclear Information System (INIS)

    Hollenbach, D.F.; Hopper, C.M.

    1997-01-01

    This paper presents the results of a preliminary criticality safety study of some potential effects of uranium reduction and aggregation in the Molten Salt Reactor Experiment (MSRE) fuel drain tanks (FDTs) during salt removal operations. Since the salt was transferred to the FDTs in 1969, radiological and chemical reactions have been converting the uranium and fluorine in the salt to UF 6 and free fluorine. Significant amounts of uranium (at least 3 kg) and fluorine have migrated out of the FDTs and into the off-gas system (OGS) and the auxiliary charcoal bed (ACB). The loss of uranium and fluorine from the salt changes the chemical properties of the salt sufficiently to possibly allow the reduction of the UF 4 in the salt to uranium metal as the salt is remelted prior to removal. It has been postulated that up to 9 kg of the maximum 19.4 kg of uranium in one FDT could be reduced to metal and concentrated. This study shows that criticality becomes a concern when more than 5 kg of uranium concentrates to over 8 wt% of the salt in a favorable geometry

  14. Investigating the temporal dynamics of suspended sediment during flood events with 7Be and 210Pbxs measurements in a drained lowland catchment

    Science.gov (United States)

    Le Gall, Marion; Evrard, Olivier; Foucher, Anthony; Laceby, J. Patrick; Salvador-Blanes, Sébastien; Manière, Louis; Lefèvre, Irène; Cerdan, Olivier; Ayrault, Sophie

    2017-02-01

    Soil erosion is recognized as one of the main processes of land degradation in agricultural areas. High suspended sediment loads, often generated from eroding agricultural landscapes, are known to degrade downstream environments. Accordingly, there is a need to understand soil erosion dynamics during flood events. Suspended sediment was therefore sampled in the river network and at tile drain outlets during five flood events in a lowland drained catchment in France. Source and sediment fallout radionuclide concentrations (7Be, 210Pbxs) were measured to quantify both the fraction of recently eroded particles transported during flood events and their residence time. Results indicate that the mean fraction of recently eroded sediment, estimated for the entire Louroux catchment, increased from 45 ± 20% to 80 ± 20% between December 2013 and February 2014, and from 65 ± 20% to 80 ± 20% in January 2016. These results demonstrate an initial flush of sediment previously accumulated in the river channel before the increasing supply of sediment recently eroded from the hillslopes during subsequent events. This research highlights the utility of coupling continuous river monitoring and fallout radionuclide measurements to increase our understanding of sediment dynamics and improve the management of soil and water resources in agricultural catchments.

  15. Analysis of three-dimensional transient seepage into ditch drains ...

    Indian Academy of Sciences (India)

    Ratan Sarmah

    waterlogged soils in many regions of the world, including. India [2, 6–9]—to name a ... predicting two-dimensional seepage into a network of ...... when d1 ¼ 0, the lower limits of integration of the integral ...... and agricultural development. Irrig.

  16. Modelling evaporation from a drained and rewetted peatland

    NARCIS (Netherlands)

    Spieksma, J F M; Moors, EJ; Dolman, A J; Schouwenaars, J M

    1997-01-01

    Evaporation from a cutover raised bog in The Netherlands was modelled using a detailed, physically based evaporation model for heterogeneous vegetation and unsaturated soil water how ''SWAPS''. The model enables a quantification of the role of heterogeneity on evaporation. Micro-meteorological

  17. Greenhouse gas fluxes in a drained peatland forest during spring frost-thaw event

    Directory of Open Access Journals (Sweden)

    M. K. Pihlatie

    2010-05-01

    Full Text Available Fluxes of greenhouse gases (GHG carbon dioxide (CO2, methane (CH4 and nitrous oxide (N2O were measured during a two month campaign at a drained peatland forest in Finland by the eddy covariance (EC technique (CO2 and N2O, and automatic and manual chambers (CO2, CH4 and N2O. In addition, GHG concentrations and soil parameters (mineral nitrogen, temperature, moisture content in the peat profile were measured. The aim of the measurement campaign was to quantify the GHG fluxes during freezing and thawing of the top-soil, a time period with potentially high GHG fluxes, and to compare different flux measurement methods. The forest was a net CO2 sink during the two months and the fluxes of CO2 dominated the GHG exchange. The peat soil was a small sink of atmospheric CH4 and a small source of N2O. Both CH4 oxidation and N2O production took place in the top-soil whereas CH4 was produced in the deeper layers of the peat, which were unfrozen throughout the measurement period. During the frost-thaw events of the litter layer distinct peaks in CO2 and N2O emissions were observed. The CO2 peak followed tightly the increase in soil temperature, whereas the N2O peak occurred with a delay after the thawing of the litter layer. CH4 fluxes did not respond to the thawing of the peat soil. The CO2 and N2O emission peaks were not captured by the manual chambers and hence we conclude that high time-resolution measurements with automatic chambers or EC are necessary to quantify fluxes during peak emission periods. Sub-canopy EC measurements and chamber-based fluxes of CO2 and N2O were comparable, although the fluxes of N2O measured by EC were close to the detection limit of the system. We conclude

  18. Effect of soil properties and hydrology on Archaeal community composition in three temperate grasslands on peat

    DEFF Research Database (Denmark)

    Görres, Carolyn-Monika; Conrad, Ralf; Petersen, Søren O

    2013-01-01

    Grasslands established on drained peat soils are regarded as negligible methane (CH4) sources; however, they can still exhibit considerable soil CH4 dynamics. We investigated archaeal community composition in two different fen peat soils and one bog peat soil under permanent grassland in Denmark........ Overall, there seemed to be a significant coupling between peat type and archaeal community composition, with local hydrology modifying the strength of this coupling....

  19. Modeling interactions of soil hydrological dynamics and soil thermal and permafrost dynamics and their effects on carbon cycling in northern high latitudes

    Science.gov (United States)

    Zhuang, Q.; Tang, J.

    2008-12-01

    Large areas of northern high latitude ecosystems are underlain with permafrost. The warming temperature and fires deteriorate the stability of those permafrost, altering hydrological cycle, and consequently soil temperature and active layer depth. These changes will determine the fate of large carbon pools in soils and permafrost over the region. We developed a modeling framework of hydrology, permafrost, and biogeochemical dynamics based on our existing modules of these components. The framework was incorporated with a new snow dynamics module and the effects of soil moisture on soil thermal properties. The framework was tested for tundra and boreal forest ecosystems at field sites with respect to soil thermal and hydrological regimes in Alaska and was then applied to the whole Alaskan ecosystems for the period of 1923-2000 at a daily time step. Our two sets of simulations with and without considering soil moisture effects indicated that the soil temperature profile and active layer depth between two simulations are significant different. The differences of soil thermal regime would expect to result in different carbon dynamics. Next, we will verify the framework with the observed data of soil moisture and soil temperature at poor-drain, moderate-drain, and well-drain boreal forest sites in Alaska. With the verified framework, we will evaluate the effects of interactions of soil thermal and hydrological dynamics on carbon dynamics for the whole northern high latitudes.

  20. Oxic limestone drains for treatment of dilute, acidic mine drainage

    Science.gov (United States)

    Cravotta, Charles A.

    1998-01-01

    Limestone treatment systems can be effective for remediation of acidic mine drainage (AMD) that contains moderate concentrations of dissolved O2 , Fe3+ , or A13+ (1‐5 mg‐L‐1 ). Samples of water and limestone were collected periodically for 1 year at inflow, outflow, and intermediate points within underground, oxic limestone drains (OLDs) in Pennsylvania to evaluate the transport of dissolved metals and the effect of pH and Fe‐ and Al‐hydrolysis products on the rate of limestone dissolution. The influent was acidic and relatively dilute (pH 1 mg‐L‐1 ) but was near neutral (pH = 6.2‐7.0); Fe and Al decreased to less than 5% of influent concentrations. As pH increased near the inflow, hydrous Fe and Al oxides precipitated in the OLDs. The hydrous oxides, nominally Fe(OH)3 and AI(OH)3, were visible as loosely bound, orange‐yellow coatings on limestone near the inflow. As time elapsed, Fe(OH)3 and AI(OH)3 particles were transported downflow. During the first 6 months of the experiment, Mn 2+ was transported conservatively through the OLDs; however, during the second 6 months, concentrations of Mn in effluent decreased by about 50% relative to influent. The accumulation of hydrous oxides and elevated pH (>5) in the downflow part of the OLDs promoted sorption and coprecipitation of Mn as indicated by its enrichment relative to Fe in hydrous‐oxide particles and coatings on limestone. Despite thick (~1 mm) hydrous‐oxide coatings on limestone near the inflow, CaCO3 dissolution was more rapid near the inflow than at downflow points within the OLD where the limestone was not coated. The rate of limestone dissolution decreased with increased residence time, pH, and concentrations of Ca2+ and HCO3‐ and decreased PCO2. The following overall reaction shows alkalinity as an ultimate product of the iron hydrolysis reaction in an OLD:Fe2+ + 0.25 O2 +CaCO3 + 2.5 H2O --> Fe(OH)3 + 2 Ca2+ + 2 HCO3-where 2 moles of CaCO3 dissolve for each mole of Fe(OH)3 produced

  1. Assessing the biodegradability of microparticles disposed down the drain.

    Science.gov (United States)

    McDonough, Kathleen; Itrich, Nina; Casteel, Kenneth; Menzies, Jennifer; Williams, Tom; Krivos, Kady; Price, Jason

    2017-05-01

    Microparticles made from naturally occurring materials or biodegradable plastics such as poly(3-hydroxy butyrate)-co-(3-hydroxy valerate), PHBV, are being evaluated as alternatives to microplastics in personal care product applications but limited data is available on their ultimate biodegradability (mineralization) in down the drain environmental compartments. An OECD 301B Ready Biodegradation Test was used to quantify ultimate biodegradability of microparticles made of PHBV foam, jojoba wax, beeswax, rice bran wax, stearyl stearate, blueberry seeds and walnut shells. PHBV polymer was ready biodegradable reaching 65.4 ± 4.1% evolved CO 2 in 5 d and 90.5 ± 3.1% evolved CO 2 in 80 d. PHBV foam microparticles (125-500 μm) were mineralized extensively with >66% CO 2 evolution in 28 d and >82% CO 2 evolution in 80 d. PHBV foam microparticles were mineralized at a similar rate and extent as microparticles made of jojoba wax, beeswax, rice bran wax, and stearyl stearate which reached 84.8  ± 4.8, 84.9  ± 2.2, 82.7  ± 4.7, and 86.4 ± 3.2% CO 2 evolution respectively in 80 d. Blueberry seeds and walnut shells mineralized more slowly only reaching 39.3  ± 6.9 and 5.1 ± 2.8% CO 2 evolution in 80 d respectively. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Seasonal thaw settlement at drained thermokarst lake basins, Arctic Alaska

    Science.gov (United States)

    Liu, Lin; Schaefer, Kevin; Gusmeroli, Alessio; Grosse, Guido; Jones, Benjamin M.; Zhang, Tinjun; Parsekian, Andrew; Zebker, Howard

    2014-01-01

    Drained thermokarst lake basins (DTLBs) are ubiquitous landforms on Arctic tundra lowland. Their dynamic states are seldom investigated, despite their importance for landscape stability, hydrology, nutrient fluxes, and carbon cycling. Here we report results based on high-resolution Interferometric Synthetic Aperture Radar (InSAR) measurements using space-borne data for a study area located on the North Slope of Alaska near Prudhoe Bay, where we focus on the seasonal thaw settlement within DTLBs, averaged between 2006 and 2010. The majority (14) of the 18 DTLBs in the study area exhibited seasonal thaw settlement of 3–4 cm. However, four of the DTLBs examined exceeded 4 cm of thaw settlement, with one basin experiencing up to 12 cm. Combining the InSAR observations with the in situ active layer thickness measured using ground penetrating radar and mechanical probing, we calculated thaw strain, an index of thaw settlement strength along a transect across the basin that underwent large thaw settlement. We found thaw strains of 10–35% at the basin center, suggesting the seasonal melting of ground ice as a possible mechanism for the large settlement. These findings emphasize the dynamic nature of permafrost landforms, demonstrate the capability of the InSAR technique to remotely monitor surface deformation of individual DTLBs, and illustrate the combination of ground-based and remote sensing observations to estimate thaw strain. Our study highlights the need for better description of the spatial heterogeneity of landscape-scale processes for regional assessment of surface dynamics on Arctic coastal lowlands.

  3. Traditional Foley drainage systems--do they drain the bladder?

    Science.gov (United States)

    Garcia, Maurice M; Gulati, Shelly; Liepmann, Dorian; Stackhouse, G Bennett; Greene, Kirsten; Stoller, Marshall L

    2007-01-01

    Foley catheters are assumed to drain the bladder to completion. Drainage characteristics of Foley catheter systems are poorly understood. To investigate unrecognized retained urine with Foley catheter drainage systems, bladder volumes of hospitalized patients were measured with bladder scan ultrasound volumetrics. Additionally, an in vitro bench top mock bladder and urinary catheter system was developed to understand the etiology of such residual volumes. A novel drainage tube design that optimizes indwelling catheter drainage was also designed. Bedside bladder ultrasound volumetric studies were performed on patients hospitalized in ward and intensive care unit. If residual urine was identified the drainage tubing was manipulated to facilitate drainage. An ex vivo bladder-urinary catheter model was designed to measure flow rates and pressures within the drainage tubing of a traditional and a novel drainage tube system. A total of 75 patients in the intensive care unit underwent bladder ultrasound volumetrics. Mean residual volume was 96 ml (range 4 to 290). In 75 patients on the hospital ward mean residual volume was 136 ml (range 22 to 647). In the experimental model we found that for every 1 cm in curl height, obstruction pressure increased by 1 cm H2O within the artificial bladder. In contrast, the novel spiral-shaped drainage tube demonstrated rapid (0.5 cc per second), continuous and complete (100%) reservoir drainage in all trials. Traditional Foley catheter drainage systems evacuate the bladder suboptimally. Outflow obstruction is caused by air-locks that develop within curled redundant drainage tubing segments. The novel drainage tubing design eliminates gravity dependent curls and associated air-locks, optimizes flow, and minimizes residual bladder urine.

  4. Variable carbon losses from recurrent fires in drained tropical peatlands.

    Science.gov (United States)

    Konecny, Kristina; Ballhorn, Uwe; Navratil, Peter; Jubanski, Juilson; Page, Susan E; Tansey, Kevin; Hooijer, Aljosja; Vernimmen, Ronald; Siegert, Florian

    2016-04-01

    Tropical peatland fires play a significant role in the context of global warming through emissions of substantial amounts of greenhouse gases. However, the state of knowledge on carbon loss from these fires is still poorly developed with few studies reporting the associated mass of peat consumed. Furthermore, spatial and temporal variations in burn depth have not been previously quantified. This study presents the first spatially explicit investigation of fire-driven tropical peat loss and its variability. An extensive airborne Light Detection and Ranging data set was used to develop a prefire peat surface modelling methodology, enabling the spatially differentiated quantification of burned area depth over the entire burned area. We observe a strong interdependence between burned area depth, fire frequency and distance to drainage canals. For the first time, we show that relative burned area depth decreases over the first four fire events and is constant thereafter. Based on our results, we revise existing peat and carbon loss estimates for recurrent fires in drained tropical peatlands. We suggest values for the dry mass of peat fuel consumed that are 206 t ha(-1) for initial fires, reducing to 115 t ha(-1) for second, 69 t ha(-1) for third and 23 t ha(-1) for successive fires, which are 58-7% of the current IPCC Tier 1 default value for all fires. In our study area, this results in carbon losses of 114, 64, 38 and 13 t C ha(-1) for first to fourth fires, respectively. Furthermore, we show that with increasing proximity to drainage canals both burned area depth and the probability of recurrent fires increase and present equations explaining burned area depth as a function of distance to drainage canal. This improved knowledge enables a more accurate approach to emissions accounting and will support IPCC Tier 2 reporting of fire emissions. © 2015 John Wiley & Sons Ltd.

  5. Effects of pond draining on biodiversity and water quality of farm ponds.

    Science.gov (United States)

    Usio, Nisikawa; Imada, Miho; Nakagawa, Megumi; Akasaka, Munemitsu; Takamura, Noriko

    2013-12-01

    Farm ponds have high conservation value because they contribute significantly to regional biodiversity and ecosystem services. In Japan pond draining is a traditional management method that is widely believed to improve water quality and eradicate invasive fish. In addition, fishing by means of pond draining has significant cultural value for local people, serving as a social event. However, there is a widespread belief that pond draining reduces freshwater biodiversity through the extirpation of aquatic animals, but scientific evaluation of the effectiveness of pond draining is lacking. We conducted a large-scale field study to evaluate the effects of pond draining on invasive animal control, water quality, and aquatic biodiversity relative to different pond-management practices, pond physicochemistry, and surrounding land use. The results of boosted regression-tree models and analyses of similarity showed that pond draining had little effect on invasive fish control, water quality, or aquatic biodiversity. Draining even facilitated the colonization of farm ponds by invasive red swamp crayfish (Procambarus clarkii), which in turn may have detrimental effects on the biodiversity and water quality of farm ponds. Our results highlight the need for reconsidering current pond management and developing management plans with respect to multifunctionality of such ponds. Efectos del Drenado de Estanques sobre la Biodiversidad y la Calidad del Agua en Estanques de Cultivo. © 2013 Society for Conservation Biology.

  6. Inverse problem in anisotropic poroelasticity: drained constants from undrained ultrasound measurements.

    Science.gov (United States)

    Berryman, James G; Nakagawa, Seiji

    2010-02-01

    Poroelastic analysis has traditionally focused on the relationship between dry and drained constants, which are assumed known, and the saturated or undrained constants, which are assumed unknown. However, there are many applications in this field of study for which the main measurements can only be made on the saturated/undrained system, and then it is uncertain what the effects of the fluids were on the system, since the drained constants remain a mystery. The work presented here shows how to deduce drained constants from undrained constants for anisotropic systems having symmetries ranging from isotropic to orthotropic. Laboratory ultrasound data are then inverted for the drained constants in three granular packings: one of glass beads, and two others for distinct types of more or less angular sand grain packings. Experiments were performed under uniaxial stress, which resulted in hexagonal (transversely isotropic) symmetry of the poroelastic response. One important conclusion from the general analysis is that the drained constants are uniquely related to the undrained constants, assuming that porosity, grain bulk modulus, and pore fluid bulk modulus are already known. Since the resulting system of equations for all the drained constants is linear, measurement error in undrained constants also propagates linearly into the computed drained constants.

  7. Inverse problem in anisotropic poroelasticity: Drained constants from undrained ultrasound measurements

    Energy Technology Data Exchange (ETDEWEB)

    Berryman, J.G.; Nakagawa, S.

    2009-11-20

    Poroelastic analysis has traditionally focused on the relationship between dry or drained constants which are assumed known and the saturated or undrained constants which are assumed unknown. However, there are many applications in this field of study for which the main measurements can only be made on the saturated/undrained system, and then it is uncertain what the eects of the uids were on the system, since the drained constants remain a mystery. The work presented here shows how to deduce drained constants from undrained constants for anisotropic systems having symmetries ranging from isotropic to orthotropic. Laboratory ultrasound data are then inverted for the drained constants in three granular packings: one of glass beads, and two others for distinct types of more or less angular sand grain packings. Experiments were performed under uniaxial stress, which resulted in hexagonal (transversely isotropic) symmetry of the poroelastic response. One important conclusion from the general analysis is that the drained constants are uniquely related to the undrained constants, assuming that porosity, grain bulk modulus, and pore uid bulk modulus are already known. Since the resulting system of equations for all the drained constants is linear, measurement error in undrained constants also propagates linearly into the computed drained constants.

  8. Homogenization of one-dimensional draining through heterogeneous porous media including higher-order approximations

    Science.gov (United States)

    Anderson, Daniel M.; McLaughlin, Richard M.; Miller, Cass T.

    2018-02-01

    We examine a mathematical model of one-dimensional draining of a fluid through a periodically-layered porous medium. A porous medium, initially saturated with a fluid of a high density is assumed to drain out the bottom of the porous medium with a second lighter fluid replacing the draining fluid. We assume that the draining layer is sufficiently dense that the dynamics of the lighter fluid can be neglected with respect to the dynamics of the heavier draining fluid and that the height of the draining fluid, represented as a free boundary in the model, evolves in time. In this context, we neglect interfacial tension effects at the boundary between the two fluids. We show that this problem admits an exact solution. Our primary objective is to develop a homogenization theory in which we find not only leading-order, or effective, trends but also capture higher-order corrections to these effective draining rates. The approximate solution obtained by this homogenization theory is compared to the exact solution for two cases: (1) the permeability of the porous medium varies smoothly but rapidly and (2) the permeability varies as a piecewise constant function representing discrete layers of alternating high/low permeability. In both cases we are able to show that the corrections in the homogenization theory accurately predict the position of the free boundary moving through the porous medium.

  9. Placement of percutaneous transhepatic biliary stent using a silicone drain with channels

    Science.gov (United States)

    Yoshida, Hiroshi; Mamada, Yasuhiro; Taniai, Nobuhiko; Mineta, Sho; Mizuguchi, Yoshiaki; Kawano, Yoichi; Sasaki, Junpei; Nakamura, Yoshiharu; Aimoto, Takayuki; Tajiri, Takashi

    2009-01-01

    This report describes a method for percutaneous transhepatic biliary stenting with a BLAKE Silicone Drain, and discusses the usefulness of placement of the drain connected to a J-VAC Suction Reservoir for the treatment of stenotic hepaticojejunostomy. Percutaneous transhepatic biliary drainage was performed under ultrasonographic guidance in a patient with stenotic hepaticojejunostomy after hepatectomy for hepatic hilum malignancy. The technique used was as follows. After dilatation of the drainage root, an 11-Fr tube with several side holes was passed through the stenosis of the hepaticojejunostomy. A 10-Fr BLAKE Silicone Drain is flexible, which precludes one-step insertion. One week after insertion of the 11-Fr tube, a 0.035-inch guidewire was inserted into the tube. After removal of the 11-Fr tube, the guidewire was put into the channel of a 10-Fr BLAKE Silicone Drain. The drain was inserted into the jejunal limb through the intrahepatic bile duct and was connected to a J-VAC Suction Reservoir. Low-pressure continued suction was applied. Patients can be discharged after insertion of the 10-Fr BLAKE Silicone Drain connected to the J-VAC Suction Reservoir. Placement of a percutaneous transhepatic biliary stent using a 10-Fr BLAKE Silicone Drain connected to a J-VAC Suction Reservoir is useful for the treatment of stenotic hepaticojejunostomy. PMID:19725159

  10. Continuous 'Passive' Registration of Non-Point Contaminant Loads Via Agricultural Subsurface Drain Tubes

    Science.gov (United States)

    Rozemeijer, J.; Jansen, S.; de Jonge, H.; Lindblad Vendelboe, A.

    2014-12-01

    Considering their crucial role in water and solute transport, enhanced monitoring and modeling of agricultural subsurface tube drain systems is important for adequate water quality management. For example, previous work in lowland agricultural catchments has shown that subsurface tube drain effluent contributed up to 80% of the annual discharge and 90-92% of the annual NO3 loads from agricultural fields towards the surface water. However, existing monitoring techniques for flow and contaminant loads from tube drains are expensive and labor-intensive. Therefore, despite the unambiguous relevance of this transport route, tube drain monitoring data are scarce. The presented study aimed developing a cheap, simple, and robust method to monitor loads from tube drains. We are now ready to introduce the Flowcap that can be attached to the outlet of tube drains and is capable of registering total flow, contaminant loads, and flow-averaged concentrations. The Flowcap builds on the existing SorbiCells, a modern passive sampling technique that measures average concentrations over longer periods of time (days to months) for various substances. By mounting SorbiCells in our Flowcap, a flow-proportional part of the drain effluent is sampled from the main stream. Laboratory testing yielded good linear relations (R-squared of 0.98) between drainage flow rates and sampling rates. The Flowcap was tested in practice for measuring NO3 loads from two agricultural fields and one glasshouse in the Netherlands. The Flowcap registers contaminant loads from tube drains without any need for housing, electricity, or maintenance. This enables large-scale monitoring of non-point contaminant loads via tube drains, which would facilitate the improvement of contaminant transport models and would yield valuable information for the selection and evaluation of mitigation options to improve water quality.

  11. Modeling flow and solute transport at a tile drain field site by explicit representation of preferential flow structures: Equifinality and uncertainty

    Science.gov (United States)

    Zehe, E.; Klaus, J.

    2011-12-01

    Rapid flow in connected preferential flow paths is crucial for fast transport of water and solutes through soils, especially at tile drained field sites. The present study tests whether an explicit treatment of worm burrows is feasible for modeling water flow, bromide and pesticide transport in structured heterogeneous soils with a 2-dimensional Richards based model. The essence is to represent worm burrows as morphologically connected paths of low flow resistance and low retention capacity in the spatially highly resolved model domain. The underlying extensive database to test this approach was collected during an irrigation experiment, which investigated transport of bromide and the herbicide Isoproturon at a 900 sqm tile drained field site. In a first step we investigated whether the inherent uncertainty in key data causes equifinality i.e. whether there are several spatial model setups that reproduce tile drain event discharge in an acceptable manner. We found a considerable equifinality in the spatial setup of the model, when key parameters such as the area density of worm burrows and the maximum volumetric water flows inside these macropores were varied within the ranges of either our measurement errors or measurements reported in the literature. Thirteen model runs yielded a Nash-Sutcliffe coefficient of more than 0.9. Also, the flow volumes were in good accordance and peak timing errors where less than or equal to 20 min. In the second step we investigated thus whether this "equifinality" in spatial model setups may be reduced when including the bromide tracer data into the model falsification process. We simulated transport of bromide for the 13 spatial model setups, which performed best with respect to reproduce tile drain event discharge, without any further calibration. Four of this 13 model setups allowed to model bromide transport within fixed limits of acceptability. Parameter uncertainty and equifinality could thus be reduced. Thirdly, we selected

  12. Drain tube migration into the anastomotic site of an esophagojejunostomy for gastric small cell carcinoma: short report

    OpenAIRE

    Lin Long-Wei; Lo Chiao; Lai Peng-Sheng; Lee Po-Chu

    2010-01-01

    Abstract Background Intraluminal migration of a drain through an anastomotic site is a rare complication of gastric surgery. Case Presentation We herein report the intraluminal migration of a drain placed after a lower esophagectomy and total gastrectomy with Roux-en-Y anastomosis for gastric small cell carcinoma. Persistent drainage was noted 1 month after surgery, and radiographic studies were consistent with drain tube migration. Endoscopy revealed the drain had migrated into the esophagoj...

  13. Water and nutrient balances in a large tile-drained agricultural catchment: a distributed modeling study

    Directory of Open Access Journals (Sweden)

    H. Li

    2010-11-01

    Full Text Available This paper presents the development and implementation of a distributed model of coupled water nutrient processes, based on the representative elementary watershed (REW approach, to the Upper Sangamon River Basin, a large, tile-drained agricultural basin located in central Illinois, mid-west of USA. Comparison of model predictions with the observed hydrological and biogeochemical data, as well as regional estimates from literature studies, shows that the model is capable of capturing the dynamics of water, sediment and nutrient cycles reasonably well. The model is then used as a tool to gain insights into the physical and chemical processes underlying the inter- and intra-annual variability of water and nutrient balances. Model predictions show that about 80% of annual runoff is contributed by tile drainage, while the remainder comes from surface runoff (mainly saturation excess flow and subsurface runoff. It is also found that, at the annual scale nitrogen storage in the soil is depleted during wet years, and is supplemented during dry years. This carryover of nitrogen storage from dry year to wet year is mainly caused by the lateral loading of nitrate. Phosphorus storage, on the other hand, is not affected much by wet/dry conditions simply because the leaching of it is very minor compared to the other mechanisms taking phosphorous out of the basin, such as crop harvest. The analysis then turned to the movement of nitrate with runoff. Model results suggested that nitrate loading from hillslope into the channel is preferentially carried by tile drainage. Once in the stream it is then subject to in-stream denitrification, the significant spatio-temporal variability of which can be related to the variation of the hydrologic and hydraulic conditions across the river network.

  14. Drainage of shallow peat harvesting areas with pipe drains; Madaltuneen turvetuotantokentaen kuivatustutkimus

    Energy Technology Data Exchange (ETDEWEB)

    Klemetti, V. [Vapo Oy, Jyvaeskylae (Finland)

    1997-12-01

    This study aims to develop pipe draining techniques in peat harvesting areas, which have been in active use so long time that the remaining peat layer is about one meter thick. The method should be technically and economically feasible as well as environmentally acceptable. Special attention is paid to pipe installation techniques, drain spacing and impacts on watercourses, which receive the drainage waters. After pipe installation the area was monitored by measuring pipe runoffs, water tables, moisture content of peat and quality of drain water. These are the results of second year. (orig.)

  15. Theory of Maxwell's fish eye with mutually interacting sources and drains

    Science.gov (United States)

    Leonhardt, Ulf; Sahebdivan, Sahar

    2015-11-01

    Maxwell's fish eye is predicted to image with a resolution not limited by the wavelength of light. However, interactions between sources and drains may ruin the subwavelength imaging capabilities of this and similar absolute optical instruments. Nevertheless, as we show in this paper, at resonance frequencies of the device, an array of drains may resolve a single source, or alternatively, a single drain may scan an array of sources, no matter how narrowly spaced they are. It seems that near-field information can be obtained from far-field distances.

  16. Drainage of shallow peat harvesting areas with pipe drains; Mataloituneen turvekentaen kuivatus putkisalaojilla

    Energy Technology Data Exchange (ETDEWEB)

    Klemetti, V.; Saenkiaho, K. [Vapo Oy, Jyvaeskylae (Finland); Rautiainen, O. [Ojamarkkinointi Oy, Heinola (Finland)

    1996-12-31

    This study aims to develop pipe draining technics in peat harvesting areas, which have been in active use so long time that the remaining peat layer is about one meter thick. The method should be technically and economically feasible as well as environmentally acceptable. Special attention is paid to pipe installation techniques, drain spacing and impacts on watercourses, which receive the drainage waters. After pipe installation the area is monitored by measuring pipe runoffs, water tables, moisture content of peat and quality of drain water

  17. Detecting peatland drains with Object Based Image Analysis and Geoeye-1 imagery.

    Science.gov (United States)

    Connolly, J; Holden, N M

    2017-12-01

    Peatlands play an important role in the global carbon cycle. They provide important ecosystem services including carbon sequestration and storage. Drainage disturbs peatland ecosystem services. Mapping drains is difficult and expensive and their spatial extent is, in many cases, unknown. An object based image analysis (OBIA) was performed on a very high resolution satellite image (Geoeye-1) to extract information about drain location and extent on a blanket peatland in Ireland. Two accuracy assessment methods: Error matrix and the completeness, correctness and quality (CCQ) were used to assess the extracted data across the peatland and at several sub sites. The cost of the OBIA method was compared with manual digitisation and field survey. The drain maps were also used to assess the costs relating to blocking drains vs. a business-as-usual scenario and estimating the impact of each on carbon fluxes at the study site. The OBIA method performed well at almost all sites. Almost 500 km of drains were detected within the peatland. In the error matrix method, overall accuracy (OA) of detecting the drains was 94% and the kappa statistic was 0.66. The OA for all sub-areas, except one, was 95-97%. The CCQ was 85%, 85% and 71% respectively. The OBIA method was the most cost effective way to map peatland drains and was at least 55% cheaper than either field survey or manual digitisation, respectively. The extracted drain maps were used constrain the study area CO 2 flux which was 19% smaller than the prescribed Peatland Code value for drained peatlands. The OBIA method used in this study showed that it is possible to accurately extract maps of fine scale peatland drains over large areas in a cost effective manner. The development of methods to map the spatial extent of drains is important as they play a critical role in peatland carbon dynamics. The objective of this study was to extract data on the spatial extent of drains on a blanket bog in the west of Ireland. The

  18. Detecting peatland drains with Object Based Image Analysis and Geoeye-1 imagery

    Directory of Open Access Journals (Sweden)

    J. Connolly

    2017-03-01

    Full Text Available Abstract Background Peatlands play an important role in the global carbon cycle. They provide important ecosystem services including carbon sequestration and storage. Drainage disturbs peatland ecosystem services. Mapping drains is difficult and expensive and their spatial extent is, in many cases, unknown. An object based image analysis (OBIA was performed on a very high resolution satellite image (Geoeye-1 to extract information about drain location and extent on a blanket peatland in Ireland. Two accuracy assessment methods: Error matrix and the completeness, correctness and quality (CCQ were used to assess the extracted data across the peatland and at several sub sites. The cost of the OBIA method was compared with manual digitisation and field survey. The drain maps were also used to assess the costs relating to blocking drains vs. a business-as-usual scenario and estimating the impact of each on carbon fluxes at the study site. Results The OBIA method performed well at almost all sites. Almost 500 km of drains were detected within the peatland. In the error matrix method, overall accuracy (OA of detecting the drains was 94% and the kappa statistic was 0.66. The OA for all sub-areas, except one, was 95–97%. The CCQ was 85%, 85% and 71% respectively. The OBIA method was the most cost effective way to map peatland drains and was at least 55% cheaper than either field survey or manual digitisation, respectively. The extracted drain maps were used constrain the study area CO2 flux which was 19% smaller than the prescribed Peatland Code value for drained peatlands. Conclusions The OBIA method used in this study showed that it is possible to accurately extract maps of fine scale peatland drains over large areas in a cost effective manner. The development of methods to map the spatial extent of drains is important as they play a critical role in peatland carbon dynamics. The objective of this study was to extract data on the spatial extent of

  19. Soil Physical and Environmental Conditions Controlling Patterned-Ground Variability at a Continuous Permafrost Site, Svalbard

    DEFF Research Database (Denmark)

    Watanabe, Tatsuya; Matsuoka, Norikazu; Christiansen, Hanne Hvidtfeldt

    2017-01-01

    properties and principal component analysis indicate that the distribution of patterned ground depends primarily on soil texture, soil moisture and the winter ground thermal regime associated with snow cover. Mudboils and composite patterns (mudboils surrounded by small polygons) occupy well-drained areas...... composed of clay-rich aeolian sediments. Compared to mudboils, composite patterns show a sharper contrast in soil texture between barren centres and vegetated rims. Hummocks filled with organic materials develop on poorly drained lowlands associated with a shallow water table. Ice-wedge polygons...

  20. Response of Soil Bulk Density and Mineral Nitrogen to Harvesting and Cultural Treatments

    Science.gov (United States)

    Minyi Zhou; Mason C. Carter; Thomas J. Dean

    1998-01-01

    The interactive effects of harvest intensity, site preparation, and fertilization on soil compaction and nitrogen mineralization were examined in a loblolly pine (Pinus taeda L.) stand growing on a sandy, well-drained soil in eastern Texas. The experimental design was 2 by 2 by 2 factorial, consisting of two harvesting treatments (mechanical whole-...

  1. Field-scale transport of water and bromide in a cracking clay soil

    NARCIS (Netherlands)

    Hendriks, R.F.A.; Hamminga, W.; Oostindie, K.; Bronswijk, J.J.B.

    1995-01-01

    The transport of a bromide tracer was studied in a cracking heavy clay soil. The soil was sampled six times and the groundwater and drain discharge were sampled frequently. Samples were analysed for bromide content. Solutes were transported in three domains: macropores, such as large continuous

  2. The cost of health professionals' brain drain in Kenya

    Directory of Open Access Journals (Sweden)

    Gbary Akpa

    2006-07-01

    Full Text Available Abstract Background Past attempts to estimate the cost of migration were limited to education costs only and did not include the lost returns from investment. The objectives of this study were: (i to estimate the financial cost of emigration of Kenyan doctors to the United Kingdom (UK and the United States of America (USA; (ii to estimate the financial cost of emigration of nurses to seven OECD countries (Canada, Denmark, Finland, Ireland, Portugal, UK, USA; and (iii to describe other losses from brain drain. Methods The costs of primary, secondary, medical and nursing schools were estimated in 2005. The cost information used in this study was obtained from one non-profit primary and secondary school and one public university in Kenya. The cost estimates represent unsubsidized cost. The loss incurred by Kenya through emigration was obtained by compounding the cost of educating a medical doctor and a nurse over the period between the average age of emigration (30 years and the age of retirement (62 years in recipient countries. Results The total cost of educating a single medical doctor from primary school to university is US$ 65,997; and for every doctor who emigrates, a country loses about US$ 517,931 worth of returns from investment. The total cost of educating one nurse from primary school to college of health sciences is US$ 43,180; and for every nurse that emigrates, a country loses about US$ 338,868 worth of returns from investment. Conclusion Developed countries continue to deprive Kenya of millions of dollars worth of investments embodied in her human resources for health. If the current trend of poaching of scarce human resources for health (and other professionals from Kenya is not curtailed, the chances of achieving the Millennium Development Goals would remain bleak. Such continued plunder of investments embodied in human resources contributes to further underdevelopment of Kenya and to keeping a majority of her people in the vicious

  3. Systematic review and meta-analysis of wound drains after thyroid surgery.

    LENUS (Irish Health Repository)

    Woods, R S R

    2014-04-01

    Drainage after routine thyroid and parathyroid surgery remains controversial. However, there is increasing evidence from a number of randomized clinical trials (RCTs) suggesting no benefit from the use of drains.

  4. 40 CFR 63.136 - Process wastewater provisions-individual drain systems.

    Science.gov (United States)

    2010-07-01

    ... restricts wind motion across the open area between the pipe and the drain) that encloses the space between...., there is no pump) or is operated with no more than slight fluctuations in the liquid level, the owner or...

  5. Influence of pleural drain insertion in lung function of patients undergoing coronary artery bypass grafting.

    Science.gov (United States)

    Ozelami Vieira, Irinea Beatriz Carvalho; Vieira, Fabiano F; Abrão, João; Gastaldi, Ada Clarice

    2012-01-01

    Longitudinal, prospective, randomized, blinded Trial to assess the influence of pleural drain (non-toxic PVC) site of insertion on lung function and postoperative pain of patients undergoing coronary artery bypass grafting in the first three days post-surgery and immediately after chest tube removal. Thirty six patients scheduled for elective myocardial revascularization with cardiopulmonary bypass (CPB) were randomly allocated into two groups: SX group (subxiphoid) and IC group (intercostal drain). Spirometry, arterial blood gases, and pain tests were recorded. Thirty one patients were selected, 16 in SX group and 15 in IC group. Postoperative (PO) spirometric values were higher in SX than in IC group (ppleural drain location on breathing. PaO(2) on the second PO increased significantly in SX group compared with IC group (pDrain with insertion in the subxiphoid region causes less change in lung function and discomfort, allowing better recovery of respiratory parameters. Copyright © 2012 Elsevier Editora Ltda. All rights reserved.

  6. Preliminary design studies of the draining tanks for the Molten Salt Fast Reactor

    International Nuclear Information System (INIS)

    Merle-Lucotte, E.; Allibert, M.; Heuer, D.; Brovchenko, M.; Laureau, A.; Ghetta, V.; Rubiolo, P.

    2014-01-01

    reactor called the Molten Salt Fast Reactor (MSFR). The reference MSFR design is a 3000 MWth reactor with a total fuel salt volume of 18 m3, operated at a mean fuel temperature of 750 deg. C. The first confinement barrier of the reactor includes a salt draining system. In case of a planned reactor shut down or in case of accidents leading to an excessive increase of the temperature in the fuel circuit, the fuel configuration may be changed passively by gravitational draining of the fuel salt in dedicated draining tank located under the reactor and designed to provide adequate reactivity margins while insuring a passive cooling of the fuel salt to extract the residual heat from the short to the long term. The present preliminary assessment of this sub-critical draining system has been performed to identify the physical constraints and to give some orders of magnitude of characteristic time periods (authors)

  7. Numerical Simulation of Liquids Draining From a Tank Using OpenFOAM

    Science.gov (United States)

    Sakri, Fadhilah Mohd; Sukri Mat Ali, Mohamed; Zaki Shaikh Salim, Sheikh Ahmad; Muhamad, Sallehuddin

    2017-08-01

    Accurate simulation of liquids draining is a challenging task. It involves two phases flow, i.e. liquid and air. In this study draining a liquid from a cylindrical tank is numerically simulated using OpenFOAM. OpenFOAM is an open source CFD package and it becomes increasingly popular among the academician and also industries. Comparisons with theoretical and results from previous published data confirmed that OpenFOAM is able to simulate the liquids draining very well. This is done using the gas-liquid interface solver available in the standard library of OpenFOAM. Additionally, this study was also able to explain the physics flow of the draining tank.

  8. Use of a Nasal Speculum for Chest-Drain Insertion: A Simple Technique

    OpenAIRE

    Saxena, Pankaj; Konstantinov, Igor E.; Newman, Mark A.J.

    2006-01-01

    Tube thoracostomy is a very commonly performed procedure in cardiothoracic surgery. Insertion of a chest drain requires expertise to minimize complications. We describe a simple technique of using a nasal speculum to perform this procedure.

  9. Postoperative intraabdominal fluid collections : a modified percutaneous drainage method using a surgical drain track

    International Nuclear Information System (INIS)

    Lee, Deok Hee; Kim, Gab Choul; Hwang, Jae Cheol; Yoon, Hyun Ki; Song, Ho Young; Sung, Kyu Bo

    2000-01-01

    In the management of postoperative fluid collection, the conventional percutaneous drainage method can be employed. Because of abdominal incisions and various types of surgical drains and/or T-tubes, the application of this method is not always easy, however. We inserted a drainage catheter through a pre-existing percutaneous track formed by a surgical drain located adjacent to the site of abnormal fluid collection. There was no need to remove the drain nor make an additional puncture in the abdominal wall. A dilator was inserted along the drain, and a guide wire was used to negotiate its intraperitoneal track and reach the accumulated fluid. The procedure was simple and safe. We briefly describe our experience of this modified percutaneous drainage technique, as used in three cases involving postoperative fluid collection. (author)

  10. Drain-Site Hernia Containing the Vermiform Appendix: Report of a Case

    Directory of Open Access Journals (Sweden)

    Markus Gass

    2013-01-01

    Full Text Available The herniated vermiform appendix has been described as content of every hernia orifice in the right lower quadrant. While the femoral and inguinal herniated vermiform appendix is frequent enough to result in an own designation, port-site or even drain-site hernias are less frequently described. We report the case of a 62-year-old woman who presented with right lower quadrant pain seven years after Roux-en-Y Cystojejunostomy for a pancreatic cyst. CT scan showed herniation of the vermiform appendix through a former drain-site. A diagnostic laparoscopy with appendectomy and direct closure of the abdominal wall defect combined with mesh reinforcement was performed. Despite the decreasing use of intraperitoneal drains over the recent years, a multitude of patients had intraperitoneal drainage in former times. These patients face nowadays the risk of drain-site hernias with sometimes even unexpected structures inside.

  11. Indwelling pleural drain for mobile management of malignant pleural effusion-combining benefits of both methods

    OpenAIRE

    Dinesh Mehta; Anshu Gupta; Sameer Singhal; Sachin Bansal

    2015-01-01

    Malignant pleural effusion is a leading cause of morbidity in lung cancer patients requiring repeated pleural aspirations or persistent intercostal drainage tube. Using an indigenous method of putting icd tube of smaller size with subcutaneous tunneling would allow draining fluid from lungs easily and painlessly when needed and avoid the need for repeated injections and chest tube insertion every time the fluid is to be drained.

  12. Indwelling pleural drain for mobile management of malignant pleural effusion-combining benefits of both methods

    Directory of Open Access Journals (Sweden)

    Dinesh Mehta

    2015-01-01

    Full Text Available Malignant pleural effusion is a leading cause of morbidity in lung cancer patients requiring repeated pleural aspirations or persistent intercostal drainage tube. Using an indigenous method of putting icd tube of smaller size with subcutaneous tunneling would allow draining fluid from lungs easily and painlessly when needed and avoid the need for repeated injections and chest tube insertion every time the fluid is to be drained.

  13. The impact of informal irrigation practices on soil drainage condition, soil pollution and land suitability for agriculture in El Saf area of El Giza Governorate

    Directory of Open Access Journals (Sweden)

    Hanan E.M. El Azab

    2015-12-01

    Full Text Available The study area was selected in El Saf District of El Giza Governorate in Egypt, covering 21461.4 ha of Nile sediments and their outskirts of alluvial higher and lower terraces. The aim of this study was to assess the impact of informal irrigation practices on drainage deterioration, soil pollution and land suitability for agricultural use using the satellite LDCM data 2013. From the lower alluvial terraces (partly cultivated using wastewater, the drainage flows westward via descending slopes resulting in land deterioration in both the alluvial lower terraces and alluvial plain of River Nile. The drainage conditions are excessively drained soils in the alluvial upper terraces within soils of Typic Haplocalcids, sandy skeletal, but in the lower terraces it partly occurred within soils of Typic Torriorthents, sandy skeletal. Moderately well drained soils occurred in soils of Typic Torriorthents, sandy in the alluvial lower terraces, while in the alluvial plain of Nile sediments are Sodic Haplotorrerts, fine. Poorly drained soils in the lower alluvial terraces have soils of Typic Epiaquents, sandy associated with Sodic Psammaquents and Aquic Haplocalcids, coarse loamy, while in the alluvial plain of River Nile the soils are Halic Epiaquerts, fine. Very poorly drained soils (submerged areas are scattered spots in both the lower alluvial terraces and the alluvial plain. In the alluvial plain of River Nile, 1967.1 ha become not suitable for the traditional cultivated crops, while in the alluvial terraces 3251.0 ha are not suitable for the proposed cultivation of Jojoba plants. Heavy metals of Cadmium (Cd, Cobalt (Co, Lead (Pb and Nickel (Ni were added to the soil surface and sub-surface in the irrigated areas by wastewater in the lower alluvial terraces (moderately well drained soils, but Cd and Co exceeded the standards of permissible total concentrations in these soils. The same metals were added to soil sub-surface layers in the alluvial plain

  14. Re-sampling of carbon stocks in forest soils and afforestation areas after 18 years – results from the 7x7 km Kvadratnet in Denmark

    DEFF Research Database (Denmark)

    Callesen, Ingeborg; Vesterdal, Lars; Stupak, Inge

    drainage regime of soils that were frequently water saturated in previous centuries. It was also hypothesized that carbon gains in soils with a low or intermediate carbon stock, typical of well-drained soils, reflected the favorable, high precipitation conditions during the monitoring period, allowing...

  15. Management of extensive surgical emphysema with subcutaneous drain: A case report

    Directory of Open Access Journals (Sweden)

    Quoc Tran

    Full Text Available Introduction: Subcutaneous emphysema (SE is a frequent and often self-limiting complication of tube thoracostomy or other cardiothoracic procedures. On rare occasions, severe and extensive surgical emphysema marked by palpable cutaneous tension, dysphagia, dysphonia, palpebral closure or associated with pneumoperitoneum, airway compromise, “tension phenomenon” and respiratory failure require treatment. Presentation of case: A 67 year old lady presented with a large spontaneous pneumothorax on the background of end-stage chronic obstructive pulmonary disease (COPD and newly diagnosed lung cancer, developed extensive surgical emphysema following insertion of a chest drain. Immediate improvement was observed after insertion of a large-bore, 26 French (Fr. intercostal catheter, subcutaneous drain which was maintained under low suction (−5 cm H2O for a further 24 h. Discussion: Several methods have been described in the literature for the treatment of extensive subcutaneous emphysema, including: emergency tracheostomy, multisite subcutaneous drainage, infraclavicular “blow holes” incisions and subcutaneous drains or simply increasing suction on an in situ chest drain. Here a large-bore, fenestrated, subcutaneous drain maintained on low negative pressure also provided the necessary decompression. Conclusion: In the absence of a comparative study to identify the most effective method to manage extensive subcutaneous emphysema, this case highlights an effective, simple and safe management option. Keywords: Pneumothorax, Subcutaneous emphysema, Drain, Low suction, Intercostal catheter, Case report

  16. Forest soils

    Science.gov (United States)

    Charles H. (Hobie) Perry; Michael C. Amacher

    2009-01-01

    Productive soils are the foundation of sustainable forests throughout the United States. Forest soils are generally subjected to fewer disturbances than agricultural soils, particularly those that are tilled, so forest soils tend to have better preserved A-horizons than agricultural soils. Another major contrast between forest and agricultural soils is the addition of...

  17. Navigating the socio-bio-geo-chemistry and engineering of nitrogen management in two illinois tile-drained watersheds.

    Science.gov (United States)

    David, Mark B; Flint, Courtney G; Gentry, Lowell E; Dolan, Mallory K; Czapar, George F; Cooke, Richard A; Lavaire, Tito

    2015-03-01

    Reducing nitrate loads from corn and soybean, tile-drained, agricultural production systems in the Upper Mississippi River basin is a major challenge that has not been met. We evaluated a range of possible management practices from biophysical and social science perspectives that could reduce nitrate losses from tile-drained fields in the Upper Salt Fork and Embarras River watersheds of east-central Illinois. Long-term water quality monitoring on these watersheds showed that nitrate losses averaged 30.6 and 23.0 kg nitrate N ha yr (Embarras and Upper Salt Fork watersheds, respectively), with maximum nitrate concentrations between 14 and 18 mg N L. With a series of on-farm studies, we conducted tile monitoring to evaluate several possible nitrate reduction conservation practices. Fertilizer timing and cover crops reduced nitrate losses (30% reduction in a year with large nitrate losses), whereas drainage water management on one tile system demonstrated the problems with possible retrofit designs (water flowed laterally from the drainage water management tile to the free drainage system nearby). Tile woodchip bioreactors had good nitrate removal in 2012 (80% nitrate reduction), and wetlands had previously been shown to remove nitrate (45% reductions) in the Embarras watershed. Interviews and surveys indicated strong environmental concern and stewardship ethics among landowners and farmers, but the many financial and operational constraints that they operate under limited their willingness to adopt conservation practices that targeted nitrate reduction. Under the policy and production systems currently in place, large-scale reductions in nitrate losses from watersheds such as these in east-central Illinois will be difficult. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  18. To drain or not to drain? Predictors of tube thoracostomy insertion and outcomes associated with drainage of traumatic hemothoraces.

    Science.gov (United States)

    Wells, Bryan J; Roberts, Derek J; Grondin, Sean; Navsaria, Pradeep H; Kirkpatrick, Andrew W; Dunham, Michael B; Ball, Chad G

    2015-09-01

    Historical data suggests that many traumatic hemothoraces (HTX) can be managed expectantly without tube thoracostomy (TT) drainage. The purpose of this study was to identify predictors of TT, including whether the quantity of pleural blood predicted tube placement, and to evaluate outcomes associated with TT versus expected management (EM) of traumatic HTXs. A retrospective cohort study of all trauma patients with HTXs and an Injury Severity Score (ISS) ≥12 managed at a level I trauma centre between April 1, 2005 and December 31, 2012 was completed. Mixed-effects models with a subject-specific random intercept were used to identify independent risk factors for TT. Logistic and log-linear regression were used to compute odds ratios (ORs) for mortality and empyema and percent increases in length of hospital and intensive care unit stay between patients managed with TT versus EM, respectively. A total of 635 patients with 749 HTXs were included in the study. Overall, 491 (66%) HTXs were drained while 258 (34%) were managed expectantly. Independent predictors of TT placement included concomitant ipsilateral flail chest [OR 3.03; 95% confidence interval (CI) 1.04-8.80; p=0.04] or pneumothorax (OR 6.19; 95% CI 1.79-21.5; p<0.01) and the size of the HTX (OR per 10cc increase 1.12; 95% CI 1.04-1.21; p<0.01). Although the adjusted odds of mortality were not significantly different between groups (OR 3.99; 95% CI 0.87-18.30; p=0.08), TT was associated with a 47.14% (95% CI, 25.57-69.71%; p<0.01) adjusted increase in hospital length of stay. Empyemas (n=29) only occurred among TT patients. Expectant management of traumatic HTX was associated with a shorter length of hospital stay, no empyemas, and no increase in mortality. Although EM of smaller HTXs may be safe, these findings must be confirmed by a large multi-centre cohort study and randomized controlled trials before they are used to guide practice. Copyright © 2015 Elsevier Ltd. All rights reserved.

  19. Safety of peritoneal and pleural drain placement in pediatric stem cell transplant recipients with severe veno-occlusive disease.

    Science.gov (United States)

    Madenci, Arin L; Stetson, Alyssa; Weldon, Christopher B; Lehmann, Leslie E

    2016-08-01

    Hepatic VOD (veno-occlusive disease) is a serious complication of HSCT (hematopoietic stem cell transplantation) and has historically been associated with high mortality. This obstruction to hepatic flow often results in fluid collections in the peritoneal and pleural cavities. Catheter placement to drain ascites or pleural fluid may reduce intra-abdominal hypertension and/or improve respiratory parameters. The safety of these interventions among critically ill, immunocompromised children is unknown. Among 32 HSCT recipients (2000-2012) with severe VOD, we assessed the primary outcome of procedural complication from peritoneal drain placement. Twenty-four (75%) patients underwent peritoneal drain placement. No patient sustained visceral perforation or hemorrhage with drain placement. Overall mortality was 47% (n = 15). The procedure was not associated with increased overall mortality (p > 0.99). Eight (25%) peritoneal drains required replacement for malfunction. Of 24 patients with peritoneal drains, one (4%) patient had a positive culture from ascitic fluid. Eight (25%) patients underwent pleural drain placement. No pleural drain-related procedural complication or infection occurred. Four (50%) of the eight patients with pleural drains had de-escalation in oxygen requirement at drain removal, compared to time of placement. In this study, peritoneal and pleural drains were safe interventions for children with severe VOD. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  20. Charge plasma based source/drain engineered Schottky Barrier MOSFET: Ambipolar suppression and improvement of the RF performance

    Science.gov (United States)

    Kale, Sumit; Kondekar, Pravin N.

    2018-01-01

    This paper reports a novel device structure for charge plasma based Schottky Barrier (SB) MOSFET on ultrathin SOI to suppress the ambipolar leakage current and improvement of the radio frequency (RF) performance. In the proposed device, we employ dual material for the source and drain formation. Therefore, source/drain is divided into two parts as main source/drain and source/drain extension. Erbium silicide (ErSi1.7) is used as main source/drain material and Hafnium metal is used as source/drain extension material. The source extension induces the electron plasma in the ultrathin SOI body resulting reduction of SB width at the source side. Similarly, drain extension also induces the electron plasma at the drain side. This significantly increases the SB width due to increased depletion at the drain end. As a result, the ambipolar leakage current can be suppressed. In addition, drain extension also reduces the parasitic capacitances of the proposed device to improve the RF performance. The optimization of length and work function of metal used in the drain extension is performed to achieve improvement in device performance. Moreover, the proposed device makes fabrication simpler, requires low thermal budget and free from random dopant fluctuations.

  1. Intra-articular injection of tranexamic acid via a drain plus drain-clamping to reduce blood loss in cementless total knee arthroplasty

    Directory of Open Access Journals (Sweden)

    Mutsuzaki Hirotaka

    2012-09-01

    Full Text Available Abstract Background Patients undergoing cementless total knee arthroplasty (TKA sometimes suffer large blood loss. In a retrospective study, we explored whether postoperative intra-articular retrograde injection of tranexamic acid (TA and leaving a drain clamp in place for 1 h reduced blood loss. Patients and methods Patients (n = 140 treated with unilateral primary cementless TKA (posterior cruciate ligament retained were divided into two groups: those who had an intra-articular injection of TA (1000 mg and drain clamping for 1 h postoperatively (study group, n = 70 and those who were not given TA and did not undergo clamping of their drains (control group, n = 70. Postoperative total blood loss, volume of drainage, hemoglobin level, transfusion amounts and rates, D-dimer level at postoperative day (POD 7, and complications were recorded. Results Total blood loss, total drainage, mean transfusion volume, and transfusion rates were lower in the study group than in controls (P P P  Conclusions Immediately postoperative intra-articular retrograde injection of TA and 1 h of drain-clamping effectively reduced blood loss and blood transfusion after cementless TKA. We believe that this method is simple, easy, and suitable for these patients.

  2. Reverse blocking characteristics and mechanisms in Schottky-drain AlGaN/GaN HEMT with a drain field plate and floating field plates

    Science.gov (United States)

    Wei, Mao; Wei-Bo, She; Cui, Yang; Jin-Feng, Zhang; Xue-Feng, Zheng; Chong, Wang; Yue, Hao

    2016-01-01

    In this paper, a novel AlGaN/GaN HEMT with a Schottky drain and a compound field plate (SD-CFP HEMT) is presented for the purpose of better reverse blocking capability. The compound field plate (CFP) consists of a drain field plate (DFP) and several floating field plates (FFPs). The physical mechanisms of the CFP to improve the reverse breakdown voltage and to modulate the distributions of channel electric field and potential are investigated by two-dimensional numerical simulations with Silvaco-ATLAS. Compared with the HEMT with a Schottky drain (SD HEMT) and the HEMT with a Schottky drain and a DFP (SD-FP HEMT), the superiorities of SD-CFP HEMT lie in the continuous improvement of the reverse breakdown voltage by increasing the number of FFPs and in the same fabrication procedure as the SD-FP HEMT. Two useful optimization laws for the SD-CFP HEMTs are found and extracted from simulation results. The relationship between the number of the FFPs and the reverse breakdown voltage as well as the FP efficiency in SD-CFP HEMTs are discussed. The results in this paper demonstrate a great potential of CFP for enhancing the reverse blocking ability in AlGaN/GaN HEMT and may be of great value and significance in the design and actual manufacture of SD-CFP HEMTs. Project supported by the National Natural Science Foundation of China (Grant Nos. 61204085, 61334002, 61306017, 61474091, 61574112, and 61574110).

  3. Reverse blocking characteristics and mechanisms in Schottky-drain AlGaN/GaN HEMT with a drain field plate and floating field plates

    International Nuclear Information System (INIS)

    Mao Wei; She Wei-Bo; Zhang Jin-Feng; Zheng Xue-Feng; Wang Chong; Hao Yue; Yang Cui

    2016-01-01

    In this paper, a novel AlGaN/GaN HEMT with a Schottky drain and a compound field plate (SD-CFP HEMT) is presented for the purpose of better reverse blocking capability. The compound field plate (CFP) consists of a drain field plate (DFP) and several floating field plates (FFPs). The physical mechanisms of the CFP to improve the reverse breakdown voltage and to modulate the distributions of channel electric field and potential are investigated by two-dimensional numerical simulations with Silvaco-ATLAS. Compared with the HEMT with a Schottky drain (SD HEMT) and the HEMT with a Schottky drain and a DFP (SD-FP HEMT), the superiorities of SD-CFP HEMT lie in the continuous improvement of the reverse breakdown voltage by increasing the number of FFPs and in the same fabrication procedure as the SD-FP HEMT. Two useful optimization laws for the SD-CFP HEMTs are found and extracted from simulation results. The relationship between the number of the FFPs and the reverse breakdown voltage as well as the FP efficiency in SD-CFP HEMTs are discussed. The results in this paper demonstrate a great potential of CFP for enhancing the reverse blocking ability in AlGaN/GaN HEMT and may be of great value and significance in the design and actual manufacture of SD-CFP HEMTs. (paper)

  4. Soil and Soil Water Relationships

    OpenAIRE

    Easton, Zachary M.; Bock, Emily

    2017-01-01

    Discusses the relationships between soil, water and plants. Discusses different types of soil, and how these soils hold water. Provides information about differences in soil drainage. Discusses the concept of water balance.

  5. Drain tube migration into the anastomotic site of an esophagojejunostomy for gastric small cell carcinoma: short report

    Directory of Open Access Journals (Sweden)

    Lin Long-Wei

    2010-05-01

    Full Text Available Abstract Background Intraluminal migration of a drain through an anastomotic site is a rare complication of gastric surgery. Case Presentation We herein report the intraluminal migration of a drain placed after a lower esophagectomy and total gastrectomy with Roux-en-Y anastomosis for gastric small cell carcinoma. Persistent drainage was noted 1 month after surgery, and radiographic studies were consistent with drain tube migration. Endoscopy revealed the drain had migrated into the esophagojejunostomy anastomotic site. The drain was removed from outside of abdominal wound while observing the anastomotic site endoscopically. The patient was treated with suction via a nasogastric tube drain for 5 days, and thereafter had an uneventful recovery. Conclusions Though drain tube migration is a rare occurrence, it should be considered in patients with persistent drainage who have undergone gastric surgery.

  6. Drain tube migration into the anastomotic site of an esophagojejunostomy for gastric small cell carcinoma: short report.

    Science.gov (United States)

    Lai, Peng-Sheng; Lo, Chiao; Lin, Long-Wei; Lee, Po-Chu

    2010-05-21

    Intraluminal migration of a drain through an anastomotic site is a rare complication of gastric surgery. We herein report the intraluminal migration of a drain placed after a lower esophagectomy and total gastrectomy with Roux-en-Y anastomosis for gastric small cell carcinoma. Persistent drainage was noted 1 month after surgery, and radiographic studies were consistent with drain tube migration. Endoscopy revealed the drain had migrated into the esophagojejunostomy anastomotic site. The drain was removed from outside of abdominal wound while observing the anastomotic site endoscopically. The patient was treated with suction via a nasogastric tube drain for 5 days, and thereafter had an uneventful recovery. Though drain tube migration is a rare occurrence, it should be considered in patients with persistent drainage who have undergone gastric surgery.

  7. Soil properties and growth of swamp white oak and pin oak on bedded soils in the lower Missouri River floodplain

    Science.gov (United States)

    John M. Kabrick; Daniel C. Dey; J. W. Van Sambeek; Michael Wallendorf; Michael A. Gold

    2005-01-01

    Restoring bottomland hardwood ecosystems is of great interest along the lower Missouri River and within the Mississippi Alluvial Valley. However, bottomland hardwood plantings commonly have a high failure rate. Among reasons cited for failures are frequent flooding and poorly drained site conditions. Soil bedding is a commonly used site preparation method shown to...

  8. In patients with extensive subcutaneous emphysema, which technique achieves maximal clinical resolution: infraclavicular incisions, subcutaneous drain insertion or suction on in situ chest drain?

    Science.gov (United States)

    Johnson, Charles H N; Lang, Sommer A; Bilal, Haris; Rammohan, Kandadai S

    2014-06-01

    A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was: 'In patients with extensive subcutaneous emphysema, which technique achieves maximal clinical resolution: infraclavicular incisions, subcutaneous drain insertion or suction on in situ chest drain?'. Altogether more than 200 papers were found using the reported search, of which 14 represented the best evidence to answer the clinical question. The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated. Subcutaneous emphysema is usually a benign, self-limiting condition only requiring conservative management. Interventions are useful in the context of severe patient discomfort, respiratory distress or persistent air leak. In the absence of any comparative study, it is not possible to choose definitively between infraclavicular incisions, drain insertion and increasing suction on an in situ drain as the best method for managing severe subcutaneous emphysema. All the three techniques described have been shown to provide effective relief. Increasing suction on a chest tube already in situ provided rapid relief in patients developing SE following pulmonary resection. A retrospective study showed resolution in 66%, increasing to 98% in those who underwent video-assisted thoracic surgery with identification and closure of the leak. Insertion of a drain into the subcutaneous tissue also provided rapid sustained relief. Several studies aided drainage by using regular compressive massage. Infraclavicular incisions were also shown to provide rapid relief, but were noted to be more invasive and carried the potential for cosmetic defect. No major complications were illustrated. © The Author 2014. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

  9. Autologous transfusion of drain contents in elective primary knee arthroplasty: its value and relevance.

    Science.gov (United States)

    Singh, Vinay Kumar; Singh, Pankaj Kumar; Javed, Sadaf; Kumar, Kuldeep; Tomar, Juhi

    2011-07-01

    Total knee arthroplasty is associated with significant post-operative blood loss often necessitating blood transfusions. Blood transfusions may be associated with transfusion reactions and may transmit human immunodeficiency virus, hepatitis C virus and hepatitis B virus, with devastating consequences. After total knee arthroplasty, transfusion of the contents of an autologous drain is becoming common practice. The aim of our study was to look at the effectiveness of these drains in elective primary total knee arthroplasty. A prospective study was conducted including 70 non-randomised patients. A normal suction drain was used in 35 patients (group A), whereas in the other 35 patients, a CellTrans™ drain was used (group B). All the operations were performed by four surgeons using a tourniquet with a medial parapatellar approach. Pre- and post-operative haemoglobin concentrations were recorded in both groups. A Student's t-test was applied to determine the statistical significance of the data collected. The average fall in post-operative haemoglobin was 3.66 g/dL (SD 1.46; range, 0.6-7.0) among patients in whom the simple drain was used (group A) and 2.29 g/dL (SD 0.92; range, 0.6-5.9) among those in whom the CellTrans™ drain was used (group B) (p<0.0001). Twenty-five units of allogeneic blood were required in group A compared to four units in group B. The rate of transfusion was 5.7% (2 patients) in the group in which CellTrans™ drain was used and 25.7% (9 patients) in the group in which a simple suction drain was used. Total knee arthroplasty is associated with significant post-operative blood loss despite best operative technique. Autologous reinfusion of the contents of a CellTrans™ drain significantly reduces the rate of post-operative blood transfusion. This study indicates that the use of an autologous drain could be recommended as routine practice in primary total knee arthroplasty.

  10. Human land-use and soil change

    Science.gov (United States)

    Wills, Skye A.; Williams, Candiss O.; Duniway, Michael C.; Veenstra, Jessica; Seybold, Cathy; Pressley, DeAnn

    2017-01-01

    Soil change refers to the alteration of soil and soil properties over time in one location, as opposed to soil variability across space. Although soils change with pedogensis, this chapter focuses on human caused soil change. Soil change can occur with human use and management over long or short time periods and small or large scales. While change can be negative or positive; often soil change is observed when short-term or narrow goals overshadow the other soil’s ecosystem services. Many soils have been changed in their chemical, physical or biological properties through agricultural activities, including cultivation, tillage, weeding, terracing, subsoiling, deep plowing, manure and fertilizer addition, liming, draining, and irrigation. Assessing soil change depends upon the ecosystem services and soil functions being evaluated. The interaction of soil properties with the type and intensity of management and disturbance determines the changes that will be observed. Tillage of cropland disrupts aggregates and decreases soil organic carbon content which can lead to decreased infiltration, increased erosion, and reduced biological function. Improved agricultural management systems can increase soil functions including crop productivity and sustainability. Forest management is most intensive during harvesting and seedling establishment. Most active management in forests causes disturbance of the soil surface which may include loss of forest floor organic materials, increases in bulk density, and increased risk of erosion. In grazing lands, pasture management often includes periods of biological, chemical and physical disturbance in addition to the grazing management imposed on rangelands. Grazing animals have both direct and indirect impacts on soil change. Hoof action can lead to the disturbance of biological crusts and other surface features impairing the soil’s physical, biological and hydrological function. There are clear feedbacks between vegetative systems

  11. Comparison and evaluation of model structures for the simulation of pollution fluxes in a tile-drained river basin.

    Science.gov (United States)

    Hoang, Linh; van Griensven, Ann; van der Keur, Peter; Refsgaard, Jens Christian; Troldborg, Lars; Nilsson, Bertel; Mynett, Arthur

    2014-01-01

    The European Union Water Framework Directive requires an integrated pollution prevention plan at the river basin level. Hydrological river basin modeling tools are therefore promising tools to support the quantification of pollution originating from different sources. A limited number of studies have reported on the use of these models to predict pollution fluxes in tile-drained basins. This study focused on evaluating different modeling tools and modeling concepts to quantify the flow and nitrate fluxes in the Odense River basin using DAISY-MIKE SHE (DMS) and the Soil and Water Assessment Tool (SWAT). The results show that SWAT accurately predicted flow for daily and monthly time steps, whereas simulation of nitrate fluxes were more accurate at a monthly time step. In comparison to the DMS model, which takes into account the uncertainty of soil hydraulic and slurry parameters, SWAT results for flow and nitrate fit well within the range of DMS simulated values in high-flow periods but were slightly lower in low-flow periods. Despite the similarities of simulated flow and nitrate fluxes at the basin outlet, the two models predicted very different separations into flow components (overland flow, tile drainage, and groundwater flow) as well as nitrate fluxes from flow components. It was concluded that the assessment on which the model provides a better representation of the reality in terms of flow paths should not only be based on standard statistical metrics for the entire river basin but also needs to consider additional data, field experiments, and opinions of field experts. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  12. Radiation dose associated with CT-guided drain placement for pediatric patients

    International Nuclear Information System (INIS)

    Schwartz, Cody J.; Isaacson, Ari J.; Fordham, Lynn Ansley; Ivanovic, Marija; Dixon, Robert G.; Taylor, J.B.

    2017-01-01

    To date, there are limited radiation dose data on CT-guided procedures in pediatric patients. Our goal was to quantify the radiation dose associated with pediatric CT-guided drain placement and follow-up drain evaluations in order to estimate effective dose. We searched the electronic medical record and picture archiving and communication system (PACS) to identify all pediatric (<18 years old) CT-guided drain placements performed between January 2008 and December 2013 at our institution. We compiled patient data and radiation dose information from CT-guided drain placements as well as pre-procedural diagnostic CTs and post-procedural follow-up fluoroscopic abscess catheter injections (sinograms). Then we converted dose-length product, fluoroscopy time and number of acquisitions to effective doses using Monte Carlo simulations and age-appropriate conversion factors based on annual quality-control testing. Fifty-two drainages were identified with mean patient age of 11.0 years (5 weeks to 17 years). Most children had diagnoses of appendicitis (n=23) or inflammatory bowel disease (n=11). Forty-seven patients had diagnostic CTs, with a mean effective dose of 7.3 mSv (range 1.1-25.5 mSv). Drains remained in place for an average of 16.9 days (range 0-75 days), with an average of 0.9 (0-5) sinograms per patient in follow-up. The mean effective dose for all drainages and follow-up exams was 5.3 mSv (0.7-17.1) and 62% (32/52) of the children had effective doses less than 5 mSv. The majority of pediatric patients who have undergone CT-guided drain placements at our institution have received total radiation doses on par with diagnostic ranges. This information could be useful when describing the dose of radiation to parents and providers when CT-guided drain placement is necessary. (orig.)

  13. Radiation dose associated with CT-guided drain placement for pediatric patients

    Energy Technology Data Exchange (ETDEWEB)

    Schwartz, Cody J.; Isaacson, Ari J.; Fordham, Lynn Ansley; Ivanovic, Marija; Dixon, Robert G. [University of North Carolina at Chapel Hill, Department of Radiology, UNC Health Care, Chapel Hill, NC (United States); Taylor, J.B. [University of North Carolina at Chapel Hill, Environment, Health and Safety, Chapel Hill, NC (United States)

    2017-05-15

    To date, there are limited radiation dose data on CT-guided procedures in pediatric patients. Our goal was to quantify the radiation dose associated with pediatric CT-guided drain placement and follow-up drain evaluations in order to estimate effective dose. We searched the electronic medical record and picture archiving and communication system (PACS) to identify all pediatric (<18 years old) CT-guided drain placements performed between January 2008 and December 2013 at our institution. We compiled patient data and radiation dose information from CT-guided drain placements as well as pre-procedural diagnostic CTs and post-procedural follow-up fluoroscopic abscess catheter injections (sinograms). Then we converted dose-length product, fluoroscopy time and number of acquisitions to effective doses using Monte Carlo simulations and age-appropriate conversion factors based on annual quality-control testing. Fifty-two drainages were identified with mean patient age of 11.0 years (5 weeks to 17 years). Most children had diagnoses of appendicitis (n=23) or inflammatory bowel disease (n=11). Forty-seven patients had diagnostic CTs, with a mean effective dose of 7.3 mSv (range 1.1-25.5 mSv). Drains remained in place for an average of 16.9 days (range 0-75 days), with an average of 0.9 (0-5) sinograms per patient in follow-up. The mean effective dose for all drainages and follow-up exams was 5.3 mSv (0.7-17.1) and 62% (32/52) of the children had effective doses less than 5 mSv. The majority of pediatric patients who have undergone CT-guided drain placements at our institution have received total radiation doses on par with diagnostic ranges. This information could be useful when describing the dose of radiation to parents and providers when CT-guided drain placement is necessary. (orig.)

  14. Gauze Impregnated With Quaternary Ammonium Salt Reduces Bacterial Colonization of Surgical Drains After Breast Reconstruction.

    Science.gov (United States)

    Strong, Amy L; Wolfe, Emily T; Shank, Nina; Chaffin, Abigail E; Jansen, David A

    2018-06-01

    Surgical site infection after breast reconstruction is associated with increased length of hospital stay, readmission rates, cost, morbidity, and mortality. Identifying methods to reduce surgical site infection without the use of antibiotics may be beneficial at reducing antimicrobial resistance, reserving the use of antibiotics for more severe cases. Quaternary ammonium salts have previously been shown to be a safe and effective antimicrobial agent in the setting of in vitro and in vivo animal experiments. A retrospective study was conducted to investigate the antimicrobial properties of a quaternary ammonium salt, 3-trimethoxysilyl propyldimethyloctadecyl ammonium chloride (QAS-3PAC; Bio-spear), at reducing surgical drain site colonization and infection after breast reconstruction (deep inferior epigastric perforator flap reconstruction or tissue expander placement). Twenty patients were enrolled, with 14 surgical drains covered with nonimpregnated gauze and 17 surgical drains covered with QAS-3PAC impregnated gauze, for the purposes of investigating bacterial colonization. Antibiotic sensitivity analysis was also conducted when bacterial cultures were positive. The overall incidence of bacterial colonization of surgical drains was lower in the treatment group compared with the control group (17.6% vs 64.3%, respectively; P = 0.008). QAS-3PAC impregnated gauze reduced the incidence of bacterial colonization of surgical drains during the first (0.0% vs 33.3%) and second (33.3% vs 87.5%; P = 0.04) postoperative week. Furthermore, no enhanced antibiotic resistance was noted on drains treated with QAS-3PAC impregnated gauze. The results of this study suggest that QAS-3PAC impregnated gauze applied over surgical drains may be an effective method for reducing the incidence of bacterial colonization.

  15. Correlation Between Cone Penetration Rate And Measured Cone Penetration Parameters In Silty Soils

    DEFF Research Database (Denmark)

    Poulsen, Rikke; Nielsen, Benjaminn Nordahl; Ibsen, Lars Bo

    2013-01-01

    This paper shows, how a change in cone penetration rate affects the cone penetration measurements, hence the cone resistance, pore pressure, and sleeve friction in silty soil. The standard rate of penetration is 20 mm/s, and it is generally accepted that undrained penetration occurs in clay while...... drained penetration occurs in sand. When lowering the penetration rate, the soil pore water starts to dissipate and a change in the drainage condition is seen. In intermediate soils such as silty soils, the standard cone penetration rate may result in a drainage condition that could be undrained......, partially or fully drained. However, lowering the penetration rate in silty soils has a great significance because of the soil permeability, and only a small change in penetration rate will result in changed cone penetration measurements. In this paper, analyses will be done on data from 15 field cone...

  16. Comparative effect of tube drain on post operative inflammatory complications of impacted mandibular third molar surgery College Hospital, Ibadan, Nigeria.

    Science.gov (United States)

    Obimakinde, O S; Fasola, A O; Arotiba, J T; Okoje, V N; Obiechina, A E

    2010-09-01

    Swelling, pain and trismus are acute reversible inflammatory complications of impacted mandibular third molar (M3) surgery. They contribute to the deterioration of quality of life and loss of several useful working hours. This study aimed to investigate whether the use of a surgical drain following M3 surgery can minimise these inflammatory complications. Eighty consecutive patients who gave consent were enrolled into the study. Patients were assigned into two groups (drain and no drain) by systematic sampling method which was modified to ensure matching of patients by age, sex and spatial relationship of the impacted mandibular third molar. The patients in the drain group (n=40) had a Foley's catheter drain inserted into the wound after the surgical procedure while the patients in the no drain group (n=40) had their wound closed without the use of drain. All patients had primary wound closure with 3.0 black silk sutures after the procedure. Demographic data, cheek dimension and maximal mouth opening were recorded before the procedure. Pain, swelling and trismus were evaluated in the two groups at 24 hours, 48 hours and 7th day after surgery. Post operative swelling and visual analogue scale score for pain were comparatively lesser in the drain group patients. The maximal interincisal distance was also more in the drain group patients. The findings from this study indicated that there is a significant benefit of using a surgical drain in minimising postoperative oedema, pain and trismus following surgical removal of impacted mandibular third molar.

  17. Hydrological patterns in warming permafrost: comparing results from a control and drained site on a floodplain tundra near Chersky, Northeast Siberia

    Science.gov (United States)

    Boelck, Sandra; Goeckede, Mathias; Hildebrandt, Anke; Vonk, Jorien; Heimann, Martin

    2017-04-01

    Permafrost areas represent a major reservoir for organic carbon. At the same time, permafrost ecosystems are very susceptible to changing climate conditions. The stability of this reservoir, i.e. changes in lateral and vertical carbon fluxes in permafrost ecosystems, largely depends on groundwater level, temperature and vegetation community. Particularly during summer when the soil thaws and a so-called active layer develops, fluctuations in carbon flux rates are often dominantly driven by water availability. Such dry soil conditions are expected to become more frequent in the future due to deepening active layers as a consequence of climate change. This could result in degradation of polygonal tundra landscape properties with channelled water transport pathways. Therefore, water table depth and the associated groundwater fluxes are crucial to understand transport patterns and to quantify the lateral export of carbon through an aquatic system. Consequently, a fundamental understanding of hydrological patterns on ecosystem structure and function is required to close the carbon balance of permafrost ecosystems. This study focuses on small-scale hydrological patterns and its influencing factors, such as topography and precipitation events. Near Chersky, Northeast Siberia, we monitored (i) a control site of floodplain tundra, and (ii) a drained site, characterised by a drainage ring which was constructed in 2004, to study the effects of water availability on the carbon cycle. This experimental disturbance simulates drainage effects following the degradation of ice-rich permafrost ecosystems under future climate change. Continuous monitoring of water table depth in drained and control areas revealed small-scale water table variations. At several key locations, we collected water samples to determine the isotopic composition (δ18O, δD) of surface water, suprapermafrost groundwater and precipitation. Furthermore, a weir at the drainage ditch was constructed to directly

  18. Moss and soil contributions to the annual net carbon flux of a maturing boreal forest

    Science.gov (United States)

    Harden, J.W.; O'Neill, K. P.; Trumbore, S.E.; Veldhuis, H.; Stocks, B.J.

    1997-01-01

    We used input and decomposition data from 14C studies of soils to determine rates of vertical accumulation of moss combined with carbon storage inventories on a sequence of burns to model how carbon accumulates in soils and moss after a stand-killing fire. We used soil drainage - moss associations and soil drainage maps of the old black spruce (OBS) site at the BOREAS northern study area (NSA) to areally weight the contributions of each moderately well drained, feathermoss areas; poorly drained sphagnum - feathermoss areas; and very poorly drained brown moss areas to the carbon storage and flux at the OBS NSA site. On this very old (117 years) complex of black spruce, sphagnum bog veneer, and fen systems we conclude that these systems are likely sequestering 0.01-0.03 kg C m-2 yr-' at OBS-NSA today. Soil drainage in boreal forests near Thompson, Manitoba, controls carbon storage and flux by controlling moss input and decomposition rates and by controlling through fire the amount and quality of carbon left after burning. On poorly drained soils rich in sphagnum moss, net accumulation and long-term storage of carbon is higher than on better drained soils colonized by feathermosses. The carbon flux of these contrasting ecosystems is best characterized by soil drainage class and stand age, where stands recently burned are net sources of CO2, and maturing stands become increasingly stronger sinks of atmospheric CO2. This approach to measuring carbon storage and flux presents a method of scaling to larger areas using soil drainage, moss cover, and stand age information.

  19. Use of laterally placed vacuum drains for management of aural hematomas in five dogs.

    Science.gov (United States)

    Pavletic, Michael M

    2015-01-01

    5 dogs (a Newfoundland, Golden Retriever, Shiba Inu, Staffordshire Terrier, and Vizsla) were referred for evaluation and treatment of unilateral aural hematomas within a week after their formation. Aural hematomas involved the left (3) or right (2) ears. With patients under anesthesia, the aural hematomas were approached surgically from the convex, or lateral, pinnal surface. Two small incisions were used to position a vacuum drain into the incised hematoma cavity. The drain exited at the base of the pinna and adjacent cervical skin. The free end of the drain was attached to a vacuum reservoir for 18 to 21 days. Drains and skin sutures were removed at this time along with the protective Elizabethan collar. All hematomas resolved and surgical sites healed during the minimum 6-month follow-up period. Cosmetic results were considered excellent in 4 of 5 patients. Slight wrinkling of the pinna in 1 patient resulted from asymmetric enlargement of the cartilaginous walls of the hematoma, where vacuum application resulted in a slight folding of the redundant lateral cartilage wall. The described treatment was efficient, economical, and minimally invasive and required no bandaging or wound care. Placement of the drain tubing on the convex (lateral) aspect sheltered the system from displacement by patients with an Elizabethan collar in place. Overall cosmetic results were excellent; asymmetric enlargement of the cartilaginous walls of the hematoma with slight folding of the pinna was seen in 1 patient.

  20. Is a drain tube necessary for minimally invasive lumbar spine fusion surgery?

    Science.gov (United States)

    Hung, Pei-I; Chang, Ming-Chau; Chou, Po-Hsin; Lin, Hsi-Hsien; Wang, Shih-Tien; Liu, Chien-Lin

    2017-03-01

    This study aimed to evaluate if closed suction wound drainage is necessary in minimally invasive surgery of transforaminal lumbar interbody fusion (MIS TLIF). This is a prospective randomized clinical study. Fifty-six patients who underwent MIS TLIF were randomly divided into groups A (with a closed suction wound drainage) and B (without tube drainage). Surgical duration, intraoperative blood loss, timing of ambulation, length of hospital stay and complications were recorded. Patients were followed up for an average of 25.3 months. Clinical outcome was assessed using the Oswestry disability index and visual analogue scale (VAS). Fusion rate was classified with the Bridwell grading system, based on plain radiograph. Both groups had similar patient demographics. The use of drains had no significant influence on perioperative parameters including operative time, estimated blood loss, length of stay and complications. Patients in group B started ambulation 1 day earlier than patients in group A (p drain tube can lead to pain, anxiety and discomfort during the postoperative period. We conclude that drain tubes are not necessary for MIS TLIF. Patients without drains had the benefit of earlier ambulation than those with drains.

  1. Drained peatlands used for extraction and agriculture: biogeochemical status with special attention to greenhouse gas fluxes and rewetting

    Science.gov (United States)

    Sirin, Andrey; Chistotin, Maxim; Suvorov, Gennady; Glagolev, Mikhail; Kravchenko, Irina; Minaeva, Tatiana

    2010-05-01

    ditches. The findings were supported by the studies conducted from 2005 at drained peatland sites in Moscow region (European part of Russia) which are used for peat extraction or as hayfield (Chistotin et al., 2006). Unexpected transient methane fluxes were observed at the inter-ditch surfaces in two types of sites: milled peat extraction area and used as a hay field after partial peat extraction. Under warm and wet conditions methane was released even from peat stockpiles. Microbiological studies showed not lower and near to twice higher genomic diversity of methanogens in extracted sites and in a hayfield as compared to virgin mire. We suppose that well-developed plant roots at the grassland provide a source of fresh organic material used for CH4 production. To test this hypothesis, a pot experiment with mesocosms which model three succession stages (bare peat, grass sowing, and developed grassland) under permanently high or fluctuating wetness was conducted. Methane efflux from peat under developed grassland was higher as compared to the other treatments. Under permanently high water supply the methane emission was 1 to 2 orders of magnitude higher. The obtained results clearly showed that plant organic matter can be an additional source of methane after rewetting which is obviously needed for abandoned peatland sites not used for agriculture any more. To mitigate the emissions, such management options as removal of the surface peat layer before rewetting could be applied. This practice could have additional benefits achieved by bringing day surface closer to ground water table level and forming more favorable soil conditions for mire species.

  2. Management techniques evaluation for sodic soils reclamation in the Valle Calido del Alto Magadalena

    International Nuclear Information System (INIS)

    Alfaro Rodriguez, Ricardo; Maria Caicedo, Antonio; Amezquita Collazos, Edgar

    1996-01-01

    An experiment was carried out at La Palmita farm, located within the irrigation district USOCOELLO, in El Espinal, Tolima, Vereda Guasimal-Pasoancho, on a soil classified as Typical Ustropept in advanced state of sodification, in order to reestablish its sustainable productive potential. Three techniques were evaluated as follows: drains spacing (50 and 100 meters), type of drains (pipes and gravel) and chemical correctives (sulfur and gypsum) plus a characteristic management in each stage of the reclamation process. After two semesters and by using rice as crop, the exchangeable sodium decreased in about 40% in the first layer, which brought the soil from a sodica condition to normal. Statistical differences were found between drains spacing and chemical correctives with best results or a spacing of 100 m and when sulfur was used as corrective. The process will continue until the hydrodynamic characteristics from 20 to 30 cm deep are reestablished as well as the nutritional balance throughout the soil profile

  3. How do peat type, sand addition and soil moisture influence the soil organic matter mineralization in anthropogenically disturbed organic soils?

    Science.gov (United States)

    Säurich, Annelie; Tiemeyer, Bärbel; Don, Axel; Burkart, Stefan

    2017-04-01

    Drained peatlands are hotspots of carbon dioxide (CO2) emissions from agriculture. As a consequence of both drainage induced mineralization and anthropogenic sand mixing, large areas of former peatlands under agricultural use contain soil organic carbon (SOC) at the boundary between mineral and organic soils. Studies on SOC dynamics of such "low carbon organic soils" are rare as the focus of previous studies was mainly either on mineral soils or "true" peat soil. However, the variability of CO2 emissions increases with disturbance and therefore, we have yet to understand the reasons behind the relatively high CO2 emissions of these soils. Peat properties, soil organic matter (SOM) quality and water content are obviously influencing the rate of CO2 emissions, but a systematic evaluation of the hydrological and biogeochemical drivers for mineralization of disturbed peatlands is missing. With this incubation experiment, we aim at assessing the drivers of the high variability of CO2 emissions from strongly anthropogenically disturbed organic soil by systematically comparing strongly degraded peat with and without addition of sand under different moisture conditions and for different peat types. The selection of samples was based on results of a previous incubation study, using disturbed samples from the German Agricultural Soil Inventory. We sampled undisturbed soil columns from topsoil and subsoil (three replicates of each) of ten peatland sites all used as grassland. Peat types comprise six fens (sedge, Phragmites and wood peat) and four bogs (Sphagnum peat). All sites have an intact peat horizon that is permanently below groundwater level and a strongly disturbed topsoil horizon. Three of the fen and two of the bog sites have a topsoil horizon altered by sand-mixing. In addition the soil profile was mapped and samples for the determination of soil hydraulic properties were collected. All 64 soil columns (including four additional reference samples) will be installed

  4. Postoperative use of drain in thyroid lobectomy – a randomized clinical trial conducted at Civil Hospital, Karachi, Pakistan

    Directory of Open Access Journals (Sweden)

    Memon Zahid

    2012-09-01

    Full Text Available Abstract Background Thyroidectomy is a common surgical procedure, after which drains are placed routinely. This study aims to assess the benefits of placing postoperative drains, its complications and affects on postoperative stay, in thyroid lobectomy. Methodology Randomized Clinical Trial of 60 goitre patients undergoing lobectomy was conducted at Civil Hospital Karachi, during July’11-December’11. Patients were randomly assigned into drain and non drain groups. Patient demographics, labs and complications were noted. Ultrasound of neck was performed on both groups. For drain group, the amount of fluid present in the surgical bed and redivac drain was added to calculate fluid collection while in non drain group it was calculated by ultrasound of neck on first and second post-op days. Data was entered and analyzed on SPSS v16 using Independent T tests. Result The mean total drain output for 2 days in non-drain group was significantly lower 10.67 (±9.072 ml while in drain group was 30.97 (±42.812 ml (p = 0.014. The mean postoperative stay of drain group (79.2 ±15.63 hours was significantly higher, as compared to mean postoperative stay of non drain group (50.4 ±7.32 hours. Mean Visual Analogue Score (VAS for pain day 1 (6.2 ±0.997 and day 2 (4.17 ±0.95 in drain group were significantly higher compared to day 1 (2.6 ±1.163 and day 2 (1.3 ±0.877 of non drain group. From drain group, 2 patients complained of stridor, dyspnea on Day 1 which subsided by Day 2 and 1 case of voice change, with no such complains in non drain group. No patients from both groups developed seroma, wound infection or hematoma. Conclusion In uncomplicated surgeries especially for lobectomy, use of drain can be omitted.

  5. Mechanism of improving forward and reverse blocking voltages in AlGaN/GaN HEMTs by using Schottky drain

    International Nuclear Information System (INIS)

    Zhao Sheng-Lei; Mi Min-Han; Luo Jun; Wang Yi; Dai Yang; Zhang Jin-Cheng; Ma Xiao-Hua; Hao Yue; Hou Bin

    2014-01-01

    In this paper, we demonstrate that a Schottky drain can improve the forward and reverse blocking voltages (BVs) simultaneously in AlGaN/GaN high-electron mobility transistors (HEMTs). The mechanism of improving the two BVs is investigated by analysing the leakage current components and by software simulation. The forward BV increases from 72 V to 149 V due to the good Schottky contact morphology. During the reverse bias, the buffer leakage in the Ohmicdrain HEMT increases significantly with the increase of the negative drain bias. For the Schottky-drain HEMT, the buffer leakage is suppressed effectively by the formation of the depletion region at the drain terminal. As a result, the reverse BV is enhanced from −5 V to −49 V by using a Schottky drain. Experiments and the simulation indicate that a Schottky drain is desirable for power electronic applications. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

  6. Soil algae

    African Journals Online (AJOL)

    Timothy Ademakinwa

    Also, the importance of algae in soil formation and soil fertility improvement cannot be over ... The presence of nitrogen fixing microalgae (Nostoc azollae) in the top soil of both vegetable ..... dung, fish food and dirty water from fish ponds on.

  7. Modeling the drain current and its equation parameters for lightly doped symmetrical double-gate MOSFETs

    International Nuclear Information System (INIS)

    Bhartia, Mini; Chatterjee, Arun Kumar

    2015-01-01

    A 2D model for the potential distribution in silicon film is derived for a symmetrical double gate MOSFET in weak inversion. This 2D potential distribution model is used to analytically derive an expression for the subthreshold slope and threshold voltage. A drain current model for lightly doped symmetrical DG MOSFETs is then presented by considering weak and strong inversion regions including short channel effects, series source to drain resistance and channel length modulation parameters. These derived models are compared with the simulation results of the SILVACO (Atlas) tool for different channel lengths and silicon film thicknesses. Lastly, the effect of the fixed oxide charge on the drain current model has been studied through simulation. It is observed that the obtained analytical models of symmetrical double gate MOSFETs are in good agreement with the simulated results for a channel length to silicon film thickness ratio greater than or equal to 2. (paper)

  8. Modeling the drain current and its equation parameters for lightly doped symmetrical double-gate MOSFETs

    Science.gov (United States)

    Bhartia, Mini; Chatterjee, Arun Kumar

    2015-04-01

    A 2D model for the potential distribution in silicon film is derived for a symmetrical double gate MOSFET in weak inversion. This 2D potential distribution model is used to analytically derive an expression for the subthreshold slope and threshold voltage. A drain current model for lightly doped symmetrical DG MOSFETs is then presented by considering weak and strong inversion regions including short channel effects, series source to drain resistance and channel length modulation parameters. These derived models are compared with the simulation results of the SILVACO (Atlas) tool for different channel lengths and silicon film thicknesses. Lastly, the effect of the fixed oxide charge on the drain current model has been studied through simulation. It is observed that the obtained analytical models of symmetrical double gate MOSFETs are in good agreement with the simulated results for a channel length to silicon film thickness ratio greater than or equal to 2.

  9. An analytical drain current model for symmetric double-gate MOSFETs

    Directory of Open Access Journals (Sweden)

    Fei Yu

    2018-04-01

    Full Text Available An analytical surface-potential-based drain current model of symmetric double-gate (sDG MOSFETs is described as a SPICE compatible model in this paper. The continuous surface and central potentials from the accumulation to the strong inversion regions are solved from the 1-D Poisson’s equation in sDG MOSFETs. Furthermore, the drain current is derived from the charge sheet model as a function of the surface potential. Over a wide range of terminal voltages, doping concentrations, and device geometries, the surface potential calculation scheme and drain current model are verified by solving the 1-D Poisson’s equation based on the least square method and using the Silvaco Atlas simulation results and experimental data, respectively. Such a model can be adopted as a useful platform to develop the circuit simulator and provide the clear understanding of sDG MOSFET device physics.

  10. An analytical drain current model for symmetric double-gate MOSFETs

    Science.gov (United States)

    Yu, Fei; Huang, Gongyi; Lin, Wei; Xu, Chuanzhong

    2018-04-01

    An analytical surface-potential-based drain current model of symmetric double-gate (sDG) MOSFETs is described as a SPICE compatible model in this paper. The continuous surface and central potentials from the accumulation to the strong inversion regions are solved from the 1-D Poisson's equation in sDG MOSFETs. Furthermore, the drain current is derived from the charge sheet model as a function of the surface potential. Over a wide range of terminal voltages, doping concentrations, and device geometries, the surface potential calculation scheme and drain current model are verified by solving the 1-D Poisson's equation based on the least square method and using the Silvaco Atlas simulation results and experimental data, respectively. Such a model can be adopted as a useful platform to develop the circuit simulator and provide the clear understanding of sDG MOSFET device physics.

  11. PWSCC Potential on the Drain Tubes of WEC Model 51F Steam Generators in Domestic Plants

    International Nuclear Information System (INIS)

    Chang, B. I.; Song, M. S.; Yoon, K. S.; Kim, I. Y.

    2009-01-01

    The drain couplings of Westinghouse Model 51F steam generators that had been operated in the domestic Nuclear Power Plants were modified and repaired in accordance with the corrective action of replacing the existing Alloy 600 weld build-up with Alloy 690(Alloy 52/152) weld build-up in order to increase its resistance to primary water stress corrosion cracking (PWSCC). The drain tube made of alloy 600, however, was not replaced and left susceptible to the PWSCC. Among the environmental, metallurgical and mechanical factors controlling a susceptibility to the PWSCC, it is believed that tensile stresses play an important role. The objective of this study is to conservatively estimate stress state of the drain tube during fabrication and when exposed to normal plant operations, and to investigate its potential for the PWSCC

  12. Leak or Fistula After Sleeve Gastrectomy: Treatment with Pigtail Drain by the Rendezvous Technique.

    Science.gov (United States)

    Soufron, Jacques

    2015-10-01

    After a sleeve gastrectomy, a leak or fistula is a serious complication. Laparoscopic drainage, drainage under US or CT scan control, or endoscopic insertion of a stent can be used, but a major re-operation is sometimes unavoidable. Endoscopic drainage with a pigtail catheter could give more success and fewer complications, but the insertion of the drain is not always possible nor does it always provide a perfect drainage. If a laparoscopic second look appears necessary, it is possible to insert a pigtail drain laparoscopically, but under endoscopic control, ensuring a correct positioning of the drain both in the peritoneal cavity and in the gastric tube. This simultaneous "rendezvous" technique could combine in this situation the advantages of purely surgical techniques and of purely endoscopic or image-guided techniques.

  13. A Drain Current Model Based on the Temperature Effect of a-Si:H Thin-Film Transistors

    International Nuclear Information System (INIS)

    Qiang Lei; Yao Ruo-He

    2012-01-01

    Based on the differential Ohm's law and Poisson's equation, an analytical model of the drain current for a-Si:H thin-film transistors is developed. This model is proposed to elaborate the temperature effect on the drain current, which indicates that the drain current is linear with temperature in the range of 290-360 K, and the results fit well with the experimental data

  14. A vapor generator equipped with an advanced drain device for the secondary side of the tubes plate

    International Nuclear Information System (INIS)

    Valadon, C.

    1995-01-01

    A draining design is proposed for the tube plate secondary side in a PWR type reactor, that does not interfere with the water flush 'street' thus allowing for an easy inspection and maintenance in the lower part of the tube bundle. The draining system is composed of a main groove on the upper side of the tube plate, which is connected to draining means situated outside the vapor generator. 6 fig

  15. Pontine infarction caused by medial branch injury of the basilar artery as a rare complication of cisternal drain placement

    OpenAIRE

    Horiuchi, Tetsuyoshi; Yamamoto, Yasunaga; Kuroiwa, Masafumi; Rahmah, Nunung Nur; Hongo, Kazuhiro

    2012-01-01

    We present a rare complication of cisternal drain placement during aneurysm surgery. A ruptured anterior communicating artery aneurysm was clipped through a right pterional approach. A cisternal drain was inserted from the retro-carotid to the prepontine cistern. Postoperatively, a left-sided paresis of the upper extremity had developed. A CT brain scan revealed that the drain was located between the pons and the basilar artery, resulting in a pontine infarction. Vascular neurosurgeons should...

  16. The Treatment Of The RSU In Controlled Drains: Their Sanitary Problem To The Production Of Energy

    International Nuclear Information System (INIS)

    Calderon U, Rafael A.

    1995-01-01

    The limitless world production of residuals generates constant concerns with relationship to its administration. The classic elimination methods as the drains controlled in front of the controversial incineration plants and gasification as well as the expectations created around the recycle practices, are reason of intense debates among city councils, specialist, environmentalist technicians and the public in general. The certain thing is that the residuals in the last 30 years have been valued economically. Today in day the residuals are appreciated by certain sectors that begin to monopolize the line of the recycle because they come them an excellent business. All the methods of elimination of residuals produce in turn others. Those of solid nature in general go to the drain, the semi-liquids becomes dehydrated for the same end. Presently work, without seeking to say that the employment of the drains is the best option, thinks about how it has more than enough they are possible to optimize its use. Showing beside their eminently sanitary vocation an energy alternative that allows the use of the combustible gas that is generated in them. An added value that is interesting if this it becomes source of well-being for social excluded nuclei and economically like it happens for example in the peripheries of the drains of the big Latin American cities. They are considered which are the main aspects that intervene in the generation, production and quality of the gas methane of the drains. Their reception methods and their use alternatives. Lastly emphasis is made in the environmental situation to European and international level about the gases of the drain, how it thinks about the topic of the greenhouse effect and which are the actions for the horizon of the year 2000. They are related some experiences in Europe on the use of the biogas

  17. Numerical simulation of draining and drying procedure for the ITER Generic Equatorial Port Plug cooling system

    International Nuclear Information System (INIS)

    Tanchuk, Victor; Grigoriev, Sergey; Lyublin, Boris; Maquet, Philippe; Senik, Konstantin; Pak, Sunil; Udintsev, Victor

    2016-01-01

    Highlights: • The cooling system of the ITER Generic Equatorial Port Plug (GEPP) is of a complicated combination of horizontal and vertical channels. • The calculation model for the entire GEPP cooling circuit comprising 12 sub-circuits and built up of 2421 finite-volume elements has been developed. • Transient analysis of this model simulating the draining procedure by the KORSAR/B1 code has been performed. • Water in amount of 263 g of initial 531 kg in the GEPP remains in the dead-ends of the DSM and DFW channels in 150 s of draining procedure. • Almost 3 h are required to boil off 263 g of water trapped in the dead-ends. - Abstract: For effective vacuum leak testing all cooling circuits serving the ITER vessel and in-vessel components shall be drained and dried so that after this procedure taking less than 100 h the purge gas passing through a component has water content less than 100 ppm. This process is four-stage, with the first stage using a short blast of compressed nitrogen to blow most of water in the coolant channels out of the circuit. This process is hindered by volumes which trap water due to gravity. To remove the trapped water, it is necessary, first, to heat up the structure by hot and compressed nitrogen, and then water is evaporated by depressurized nitrogen. The cooling system of the ITER Diagnostic Equatorial Port Plugs is of a complicated hydraulic configuration. The system branching might make difficult removal of water from the piping in the scheduled draining mode. The authors have proposed the KORSAR computation code to simulate draining of the GEPP cooling circuit. The numerical simulation performed has made it possible to describe the process dynamics during draining of the entire GEPP cooling circuit and to define the process time, amount and location of residual water and evolution of two-phase flow regime.

  18. Numerical simulation of draining and drying procedure for the ITER Generic Equatorial Port Plug cooling system

    Energy Technology Data Exchange (ETDEWEB)

    Tanchuk, Victor, E-mail: Victor.Tanchuk@sintez.niiefa.spb.su [JSC “D.V. Efremov Institute of Electrophysical Apparatus”, 196641 St. Petersburg (Russian Federation); Grigoriev, Sergey; Lyublin, Boris [JSC “D.V. Efremov Institute of Electrophysical Apparatus”, 196641 St. Petersburg (Russian Federation); Maquet, Philippe [ITER Organization, Route de Vinon sur Verdon, 13115 St Paul-lez-Durance (France); Senik, Konstantin [JSC “D.V. Efremov Institute of Electrophysical Apparatus”, 196641 St. Petersburg (Russian Federation); Pak, Sunil [National Fusion Research Institute, Daejeon (Korea, Republic of); Udintsev, Victor [ITER Organization, Route de Vinon sur Verdon, 13115 St Paul-lez-Durance (France)

    2016-11-01

    Highlights: • The cooling system of the ITER Generic Equatorial Port Plug (GEPP) is of a complicated combination of horizontal and vertical channels. • The calculation model for the entire GEPP cooling circuit comprising 12 sub-circuits and built up of 2421 finite-volume elements has been developed. • Transient analysis of this model simulating the draining procedure by the KORSAR/B1 code has been performed. • Water in amount of 263 g of initial 531 kg in the GEPP remains in the dead-ends of the DSM and DFW channels in 150 s of draining procedure. • Almost 3 h are required to boil off 263 g of water trapped in the dead-ends. - Abstract: For effective vacuum leak testing all cooling circuits serving the ITER vessel and in-vessel components shall be drained and dried so that after this procedure taking less than 100 h the purge gas passing through a component has water content less than 100 ppm. This process is four-stage, with the first stage using a short blast of compressed nitrogen to blow most of water in the coolant channels out of the circuit. This process is hindered by volumes which trap water due to gravity. To remove the trapped water, it is necessary, first, to heat up the structure by hot and compressed nitrogen, and then water is evaporated by depressurized nitrogen. The cooling system of the ITER Diagnostic Equatorial Port Plugs is of a complicated hydraulic configuration. The system branching might make difficult removal of water from the piping in the scheduled draining mode. The authors have proposed the KORSAR computation code to simulate draining of the GEPP cooling circuit. The numerical simulation performed has made it possible to describe the process dynamics during draining of the entire GEPP cooling circuit and to define the process time, amount and location of residual water and evolution of two-phase flow regime.

  19. Multiyear nutrient removal performance of three constructed wetlands intercepting tile drain flows from grazed pastures.

    Science.gov (United States)

    Tanner, Chris C; Sukias, James P S

    2011-01-01

    Subsurface tile drain flows can be a major s ource of nurient loss from agricultural landscapes. This study quantifies flows and nitrogen and phosphorus yields from tile drains at three intensively grazed dairy pasture sites over 3- to 5-yr periods and evaluates the capacity of constructed wetlands occupying 0.66 to 1.6% of the drained catchments too reduce nutrient loads. Continuous flow records are combined with automated flow-proportional sampling of nutrient concentrations to calculate tile drain nutrient yields and wetland mass removal rates. Annual drainage water yields rangedfrom 193 to 564 mm (16-51% of rainfall) at two rain-fed sites and from 827 to 853 mm (43-51% of rainfall + irrigation) at an irrigated site. Annually, the tile drains exported 14 to 109 kg ha(-1) of total N (TN), of which 58 to 90% was nitrate-N. Constructed wetlands intercepting these flows removed 30 to 369 gTN m(-2) (7-63%) of influent loadings annually. Seasonal percentage nitrate-N and TN removal were negatively associated with wetland N mass loadings. Wetland P removal was poor in all wetlands, with 12 to 115% more total P exported annually overall than received. Annually, the tile drains exported 0.12 to 1.38 kg ha of total P, of which 15 to 93% was dissolved reactive P. Additional measures are required to reduce these losses or provide supplementary P removal. Wetland N removal performance could be improved by modifying drainage systems to release flows more gradually and improving irrigation practices to reduce drainage losses.

  20. Effects of Drains on Pain, Comfort and Anxiety in Patients Undergone Surgery

    Directory of Open Access Journals (Sweden)

    Ummu Yildiz Findik

    2013-01-01

    Full Text Available Backround: Surgical drains negatively affect patients’ comfort, cause anxiety along with pain, as they are used to promote healing after surgery.Purpose: This study aimed to determine pain, comfort and anxiety levels of patients with drains postoperatively.Methodology: Research was performed with 192 patients undergone abdominal, neck, breast and open heart surgery and had surgical and underwater chest drains at the postoperative period. Patient Information Form, Numerical Pain Scale, General Comfort Questionnaire and Trait Anxiety Scale was used for collection of data. In evaluating the data, we used the t-test, variance and correlation analysis, mean, percentage and frequency.Results: The patients’ mean score of pain was 4.67±2.93, comfort was 2.75±0.29 and anxiety was 39.31±9.21. It was found statistically significant that the comfort level decreases as the pain level increases and that the patients undergone open heart surgery and with underwater chest drains have higher pain levels. It was found statistically significant that, comfort level in patients undergone abdominal or cardiac surgery is lower than patients undergone breast or neck surgery, and that the comfort level decreases as the duration of drains increases. The increasing state anxiety while pain increases and comfort decreases was found statistically significant.Conclusions: Surgeries and drains applied after these procedures decrease the comfort level of the patients as increases the pain level. Also, pain and discomfort increase the patients’ anxiety. Nurses who providing care to these patients are suggested to improve measures about pain and anxiety reduction for maintaining of comfort.

  1. The hydrology of a drained topographical depression within an agricutlural field in north-central Iowa

    Science.gov (United States)

    Roth, Jason L.; Capel, Paul D.

    2012-01-01

    North-central Iowa is an agriculturally intensive area comprising the southeastern portion of the Prairie Pothole Region, a landscape containing a high density of enclosed topographical depressions. Artificial drainage practices have been implemented throughout the area to facilitate agricultural production. Vertical surface drains are utilized to drain the topographical depressions that accumulate water. This study focuses on the hydrology of a drained topographical depression located in a 39.5 ha agricultural field. To assess the hydrology of the drained depression, a water balance was constructed for 11 ponding events during the 2008 growing season. Continuous pond and groundwater level data were obtained with pressure transducers. Flows into the vertical surface drain were calculated based on pond depth. Precipitation inflows and evaporative outflows of the ponds were calculated using climatic data. Groundwater levels were used to assess groundwater/pond interactions. Results of the water balances show distinct differences between the inflows to and outflows from the depression based on antecedent conditions. In wet conditions, groundwater inflow sustained the ponds. The ponds receded only after the groundwater level declined to below the land surface. In drier conditions, groundwater was not a source of water to the depression. During these drier conditions, infiltration comprised 30% of the outflows from the depression during declining pond stages. Over the entire study period, the surface drain, delivering water to the stream, was the largest outflow from the pond, accounting for 97% of the outflow, while evapotranspiration was just 2%. Precipitation onto the pond surface proved to be a minor component, accounting for 4% of the total inflows.

  2. Peat Soil Stabilization using Lime and Cement

    Directory of Open Access Journals (Sweden)

    Mohd Zambri Nadhirah

    2018-01-01

    Full Text Available This paper presents a study of the comparison between two additive Lime and Cement for treating peat soil in term of stabilization. Peat and organic soils are commonly known for their high compressibility, extremely soft, and low strength. The aim of this paper is to determine the drained shear strength of treated peat soil from Perlis for comparison purposes. Direct Shear Box Test was conducted to obtain the shear strength for all the disturbed peat soil samples. The quick lime and cement was mixed with peat soil in proportions of 10% and 20% of the dry weight peat soil. The experiment results showed that the addition of additives had improved the strength characteristics of peat soil by 14% increment in shear strength. In addition, the mixture of lime with peat soil yield higher result in shear strength compared to cement by 14.07% and 13.5% respectively. These findings indicate that the lime and cement is a good stabilizer for peat soil, which often experienced high amount of moisture content.

  3. Peat Soil Stabilization using Lime and Cement

    Science.gov (United States)

    Zambri, Nadhirah Mohd; Ghazaly, Zuhayr Md.

    2018-03-01

    This paper presents a study of the comparison between two additive Lime and Cement for treating peat soil in term of stabilization. Peat and organic soils are commonly known for their high compressibility, extremely soft, and low strength. The aim of this paper is to determine the drained shear strength of treated peat soil from Perlis for comparison purposes. Direct Shear Box Test was conducted to obtain the shear strength for all the disturbed peat soil samples. The quick lime and cement was mixed with peat soil in proportions of 10% and 20% of the dry weight peat soil. The experiment results showed that the addition of additives had improved the strength characteristics of peat soil by 14% increment in shear strength. In addition, the mixture of lime with peat soil yield higher result in shear strength compared to cement by 14.07% and 13.5% respectively. These findings indicate that the lime and cement is a good stabilizer for peat soil, which often experienced high amount of moisture content.

  4. Should I stay or should I go? An institutional approach to brain drain

    OpenAIRE

    Cassar, Lea; Frey, Bruno S

    2010-01-01

    This paper suggests that institutional factors which reward social net- works at the expenses of productivity can play an important role in ex- plaining brain drain. The e€ects of social networks on brain drain are analyzed in a decision theory framework with asymmetric information. We distinguish between the role of insidership and personal connections. The larger the cost of being an outsider, the smaller is the number and the average ability of researchers working in the domestic job mar...

  5. Sampling and analysis plan (SAP) for WESF drains and TK-100 sump

    International Nuclear Information System (INIS)

    Simmons, F.M.

    1998-01-01

    The intent of this project is to determine whether the Waste Encapsulation and Storage Facility (WESF) floor drain piping and the TK-100 sump are free from contamination. TK-100 is currently used as a catch tank to transfer low level liquid waste from WESF to Tank Farms via B Plant. This system is being modified as part of the WESF decoupling since B Plant is being deactivated. As a result of the 1,1,1-trichloroethane (TCA) discovery in TK-100, the associated WESF floor drains and the pit sump need to be sampled. Breakdown constituents have been reviewed and found to be non-hazardous. There are 29 floor drains that tie into a common header leading into the tank. To prevent high exposure during sampling of the drains, TK-100 will be removed into the B Plant canyon and a new tank will be placed in the pit before any floor drain samples are taken. The sump will be sampled prior to TK-100 removal. A sample of the sludge and any liquid in the sump will be taken and analyzed for TCA and polychlorinated biphenyl (PCB). After the sump has been sampled, the vault floor will be flushed. The flush will be transferred from the sump into TK-100. TK-100 will be moved into B Plant. The vault will then be cleaned of debris and visually inspected. If there is no visual indication of TCA or PCB staining, the vault will be painted and a new tank installed. If there is an indication of TCA or PCB from laboratory analysis or staining, further negotiations will be required to determine a path forward. A total of 8 sets of three 40ml samples will be required for all of the floor drains and sump. The sump set will include one 125ml solid sample. The only analysis required will be for TCA in liquids. PCBs will be checked in sump solids only. The Sampling and Analysis Plan (SAP) is written to provide direction for the sampling and analytical activities of the 29 WESF floor drains and the TK-100 sump. The intent of this plan is to define the responsibilities of the various organizations

  6. High performance AlGaN/GaN HEMTs with 2.4 μm source-drain spacing

    International Nuclear Information System (INIS)

    Wang Dongfang; Wei Ke; Yuan Tingting; Liu Xinyu

    2010-01-01

    This paper describes the performance of AlGaN/GaN HEMTs with 2.4 μm source-drain spacing. So far these are the smallest source-drain spacing AlGaN/GaN HEMTs which have been implemented with a domestic wafer and domestic process. This paper also compares their performance with that of 4 μm source-drain spacing devices. The former exhibit higher drain current, higher gain, and higher efficiency. It is especially significant that the maximum frequency of oscillation noticeably increased. (semiconductor integrated circuits)

  7. Effects of Fe plaque and organic acids on metal uptake by wetland plants under drained and waterlogged conditions.

    Science.gov (United States)

    Li, W C; Deng, H; Wong, M H

    2017-12-01

    This study aims to assess the role of Fe plaque in metal uptake and translocation by different wetland plants and examine the effects of organic acids on metal detoxification in wetland plants. It was found that although exposed to a similar level of metals in rhizosphere soil solution, metal uptake by shoots of Cypercus flabelliformis and Panicum paludosum was greatly reduced, consequently leading to a better growth under flooded than under drained conditions. This may be related to the enhanced Fe plaque in the former, but due to the decreased root permeability in the latter under anoxic conditions. The Fe plaque on root surface has potential to sequester metals and then reduce metal concentrations and translocation in shoot tissues. However, whether the Fe plaque acts as a barrier to metal uptake and translocation may also be dependent on the root anatomy. Although metal tolerance in wetland plants mainly depends upon their metal exclusion ability, the higher-than-toxic-level of metal concentrations in some species indicates that internal metal detoxification might also exist. It was suggested that malic or citric acid in shoots of P. paludosum and C. flabelliformis may account for their internal detoxification for Zn. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Measurement and modelling of CO2 flux from a drained fen peatland cultivated with reed canary grass and spring barley

    DEFF Research Database (Denmark)

    Kandel, Tanka Prasad; Elsgaard, Lars; Lærke, Poul Erik

    2013-01-01

    Cultivation of bioenergy crops has been suggested as a promising option for reduction of greenhouse gas (GHG) emissions from arable organic soils (Histosols). Here, we report the annual net ecosystem exchange (NEE) fluxes of CO2 as measured with a dynamic closed chamber method at a drained fen......-C m−2 in RCG and SB plots, respectively, with Rfb accounting for 32 and 22% respectively. Total estimated annual GP was −1818 ± 42 and −1329 ± 66 g CO2-C m−2 in RCG and SB plots leading to a NEE of 69 ± 36 g CO2-C m−2 yr−1 in RCG plots (i.e., a weak net source) and −41 ± 47 g CO2-C m−2 yr−1 in SB...

  9. Total selenium and selenium species in irrigation drain inflows to the Salton Sea, California, October 2008 and January 2009

    Science.gov (United States)

    May, Thomas W.; Walther, Michael J.; Saiki, Michael K.; Brumbaugh, William G.

    2009-01-01

    This report presents the results for two sampling periods (October 2008 and January 2009) during a 4-year monitoring program to characterize selenium concentrations in selected irrigation drains flowing into the Salton Sea, California. Total selenium, selenium species (dissolved selenite, selenate, organoselenium), and total suspended solids were determined in water samples. Total selenium also was determined in water column particulates and in sediment, detritus, and biota that included algae, plankton, midge larvae (family, Chironomidae), and two fish species (western mosquitofish, Gambusia affinis, and sailfin molly, Poecilia latipinna). In addition, sediments were analyzed for percent total organic carbon and particle size. Mean total selenium concentrations in water for both sampling periods ranged from 1.00 to 33.6 micrograms per liter, predominately as selenate, which is typical of waters where selenium is leached out of selenium-containing marine shales and associated soils under alkaline and oxidizing conditions. Total selenium concentrations (micrograms per gram dry weight) ranged as follows: algae, 1.52 to 8.26; plankton, 0.79 to 3.66; midges, 2.68 to 50.6; fish, 3.09 to 30.4; detritus, 1.78 to 58.0; and sediment, 0.42 to 10.0.

  10. Total selenium and selenium species in irrigation drain inflows to the Salton Sea, California, April and July 2008

    Science.gov (United States)

    May, Thomas W.; Walther, Michael J.; Saiki, Michael K.; Brumbaugh, William G.

    2009-01-01

    This report presents the results for two sampling periods (April 2008 and July 2008) during a 4-year monitoring program to characterize selenium concentrations in selected irrigation drains flowing into the Salton Sea, California. Total selenium, selenium species (dissolved selenite, selenate, organoselenium), and total suspended solids were determined in water samples and total selenium was determined in water column particulates and in sediment, detritus, and biota that included algae, plankton, midge larvae (family, Chironomidae), and two fish species - western mosquitofish (Gambusia affinis) and sailfin molly (Poecilia latipinna). In addition, sediments were analyzed for percent total organic carbon and particle size. Mean total selenium concentrations in water for both sampling periods ranged from 1.93 to 44.2 micrograms per liter, predominately as selenate, which is typical of waters where selenium is leached out of selenium-containing marine shales and associated soils under alkaline and oxidizing conditions. Total selenium concentrations (micrograms per gram dry weight) ranged as follows: algae, 0.75 to 3.39; plankton, 0.88 to 4.03; midges, 2.52 to 44.3; fish, 3.37 to 18.9; detritus, 1.11 to 13.6; sediment, 0.11 to 8.93.

  11. Total selenium and selenium species in irrigation drain inflows to the Salton Sea, California, October 2007 and January 2008

    Science.gov (United States)

    May, Thomas W.; Walther, Michael J.; Saiki, Michael K.; Brumbaugh, William G.

    2008-01-01

    This report presents the results for two sampling periods (October 2007 and January 2008) during a 4-year monitoring program to characterize selenium concentrations in selected irrigation drains flowing into the Salton Sea, California. Total selenium, selenium species (selenite, selenate, organoselenium), and total suspended solids were determined in water samples, and total selenium was determined in sediment, detritus, and biota that included algae, plankton, midge larvae (family, Chironomidae), and two fish species?western mosquitofish (Gambusia affinis) and sailfin molly (Poecilia latipinna). In addition, sediments were analyzed for percent total organic carbon and particle size. Mean total selenium concentrations in water for both sampling periods ranged from 0.97 to 64.5 micrograms per liter, predominately as selenate, which is typical of waters where selenium is leached out of selenium-containing marine shales and associated soils under alkaline and oxidizing conditions. Total selenium concentrations (micrograms per gram dry weight) ranged as follows: algae, 0.95 to 5.99; plankton, 0.15 to 19.3; midges, 1.39 to 15.4; fish, 3.71 to 25.1; detritus, 0.85 to 21.7; sediment, 0.32 to 7.28.

  12. DETERMINATION OF LIQUID FILM THICKNESS FOLLOWING DRAINING OF CONTACTORS, VESSELS, AND PIPES IN THE MCU PROCESS

    International Nuclear Information System (INIS)

    Poirier, M; Fernando Fondeur, F; Samuel Fink, S

    2006-01-01

    The Department of Energy (DOE) identified the caustic side solvent extraction (CSSX) process as the preferred technology to remove cesium from radioactive waste solutions at the Savannah River Site (SRS). As a result, Washington Savannah River Company (WSRC) began designing and building a Modular CSSX Unit (MCU) in the SRS tank farm to process liquid waste for an interim period until the Salt Waste Processing Facility (SWPF) begins operations. Both the solvent and the strip effluent streams could contain high concentrations of cesium which must be removed from the contactors, process tanks, and piping prior to performing contactor maintenance. When these vessels are drained, thin films or drops will remain on the equipment walls. Following draining, the vessels will be flushed with water and drained to remove the flush water. The draining reduces the cesium concentration in the vessels by reducing the volume of cesium-containing material. The flushing, and subsequent draining, reduces the cesium in the vessels by diluting the cesium that remains in the film or drops on the vessel walls. MCU personnel requested that Savannah River National Laboratory (SRNL) researchers conduct a literature search to identify models to calculate the thickness of the liquid films remaining in the contactors, process tanks, and piping following draining of salt solution, solvent, and strip solution. The conclusions from this work are: (1) The predicted film thickness of the strip effluent is 0.010 mm on vertical walls, 0.57 mm on horizontal walls and 0.081 mm in horizontal pipes. (2) The predicted film thickness of the salt solution is 0.015 mm on vertical walls, 0.74 mm on horizontal walls, and 0.106 mm in horizontal pipes. (3) The predicted film thickness of the solvent is 0.022 mm on vertical walls, 0.91 mm on horizontal walls, and 0.13 mm in horizontal pipes. (4) The calculated film volume following draining is: (a) Salt solution receipt tank--1.6 gallons; (b) Salt solution feed

  13. Assessment on urban soil pollution by biocides from building materials

    DEFF Research Database (Denmark)

    Bollmann, Ulla E.; Vollertsen, Jes; Bester, Kai

    2015-01-01

    . Based on a monitoring study of stormwater runoff from a residential catchment as well as direct façade runoff analysis, the present study was assessing the pollution of urban soil to biocides from building material. The stormwater runoff of a residential catchment in Silkeborg (Denmark) was monitored...... from a freshly painted or rendered house, it is obvious that a huge part is actually draining directly to the soil and not to the sewer system. Consequently, the soil in urban areas is exposed to stormwater highly polluted by biocides which might affect the microbial community there....

  14. Trace elements distribution in the Amazon floodplain soils

    International Nuclear Information System (INIS)

    Fernandes, E.A.N.; Ferraz, E.S.B.; Oliveira, H.

    1994-01-01

    Neutron activation analysis was performed on aluvial soil samples from several sites on the foodplains of the Amazon River and its major tributaries for trace elements determination. The spatial and temporal variations of chemical composition of floodland sediments in the Amazon basin are discussed. No significant difference was found in trace elemental distribution in the floodland soils along the Amazon main channel, even after the source material has been progressively diluted with that from lowland draining tributaries. It was also seen that the average chemical composition of floodplain soils compares well with that of the suspended sedimets. (author) 12 refs.; 5 figs.; 2 tabs

  15. Land Use Impacts on Water Quality of Rivers draining from Mulanje ...

    African Journals Online (AJOL)

    Land Use Impacts on Water Quality of Rivers draining from Mulanje Mountain: A Case of Ruo River in the Southern Malawi. ... The research recommends an integrated water resources management approach where all users and relevant stakeholders should take an active role in the conservation of Ruo River catchment in ...

  16. Umbilical vein draining into the inferior vena cava via the internal iliac vein, bypassing the liver

    International Nuclear Information System (INIS)

    Currarino, G.; Stannard, M.W.; Texas Univ., Dallas, TX; Kolni, H.

    1991-01-01

    This is the third report of an anomalous umbilical vein draining ectopically in a left pelvic vein, probably the left internal iliac, and through the inferior vena cava into the right atrium. The anomaly was encountered in a newborn infant with nonimmune hydrops fetalis, hypertrophic cardiomyopathy, multiorgan failure and possibly Noonan Syndrome. (orig.)

  17. Configuration of particle drain for the high energy charged particles in the magnetic dipole field

    International Nuclear Information System (INIS)

    Amirkhanov, I.V.; Zhidkov, E.P.; Ignatov, V.V.; Il'ina, A.N.; Il'in, V.D.; Kuznetsov, S.N.; Yushkov, B.Yu.

    1987-01-01

    The boundary of particle leakage from the magnetic dipole trap depending on the value of adiabatic parameter is investigated. By trajectory computation a generalized analytical expression is determined for the shape of particle drain by x ≤ 1. It is shown that generally accepted adiabatic loss cone is a particular case of x → 0

  18. Oral tolerance is determined at the level of draining lymph nodes

    NARCIS (Netherlands)

    Wilsem, van E.G.; BrevÃ, J.; Savelkoul, H.; Claessen, A.; Scheper, R.J.; Kraal, G.

    1995-01-01

    In the skin and in the epithelium of the oral mucosa a comparable network of Langerhans cells can be found. Antigen application on either epithelium leads to rapid emigration of Langerhans cells to the draining lymph nodes. Application on the oral mucosa leads to tolerance induction while

  19. Evaluation of the necessity for chest drain placement following thoracoscopic wedge resection.

    Science.gov (United States)

    Lu, Ting-Yu; Chen, Jian-Xun; Chen, Pin-Ru; Lin, Yu-Sen; Chen, Chien-Kuang; Kao, Pei-Yu; Huang, Tzu-Ming; Fang, Hsin-Yuan

    2017-05-01

    To evaluate the outcomes of patients who underwent thoracoscopic wedge resection without chest drain placement. The subjects of this retrospective study were 89 patients, who underwent thoracoscopic wedge resection at our hospital between January, 2013 and July, 2015. A total of 45 patients whose underlying condition did not meet the following criteria were assigned to the "chest drain placement group" (group A): peripheral lesions, healthy lung parenchyma, no intraoperative air leaks, hemorrhage or effusion accumulation, and no pleural adhesion. The other 44 patients whose underlying condition met the criteria were assigned to the "no chest drain placement group" (group B). Patient characteristics, specimen data, and postoperative conditions were analyzed and compared between the groups. Group A patients had poorer forced expiratory volume in one second (FEV1) values, less normal spirometric results, significantly higher resected lung volume, a greater maximum tumor-pleura distance, and a larger maximum tumor size. They also had a longer postoperative hospital stay. There was no difference between the two groups in postoperative complications. Avoiding chest drain placement after a thoracoscopic wedge resection appears to be safe and beneficial for patients who have small peripheral lesions and healthy lung parenchyma.

  20. Method of bilateral pleural drainage by single Blake drain after esophagectomy.

    Science.gov (United States)

    Niwa, Yukiko; Koike, Masahiko; Oya, Hisaharu; Iwata, Naoki; Kobayashi, Daisuke; Kanda, Mitsuro; Tanaka, Chie; Yamada, Suguru; Fujii, Tsutomu; Nakayama, Goro; Sugimoto, Hiroyuki; Nomoto, Shuji; Fujiwara, Michitaka; Kodera, Yasuhiro

    2015-03-01

    Clinicians often encounter left pleural effusion after esophagectomy, which sometimes necessitates thoracentesis. We have introduced a new drainage method, bilateral pleural drainage by single Blake drain (BDSD), which we have been using since April 2013. This study aims to evaluate the performance of the BDSD. The BDSD method employs a 15-F Blake drain inserted from the right thoracic cavity to the left thoracic cavity across the posterior mediastinum. The conventional drain (CD) group consisted of 50 patients with a 19-F Blake drain placed in the right thoracic cavity during the period from April 2012 to March 2013. The BDSD group consisted of 54 patients treated from April 2013 to June 2014. The amount of total drainage in the BDSD group was significantly higher than that in the CD group (P pleural effusion and left lower lobe atelectasis in the BDSD group were significantly lower than those in the CD group (P pleural effusion necessitating thoracentesis drainage in the BDSD group. Compared with the conventional method, BDSD was able to evacuate bilateral pleural effusion more effectively, and the incidences of left pleural effusion and left atelectasis were lower. This method is therefore clinically useful after esophagectomy.

  1. An elusive persistent left superior vena cava draining into left atrium

    NARCIS (Netherlands)

    A. Soward; F.J. ten Cate (Folkert); P.M. Fioretti (Paolo); P.W.J.C. Serruys (Patrick); J.R.T.C. Roelandt (Jos)

    1986-01-01

    textabstractA case report of a persistent left superior vena cava draining into left atrium with a fibromuscular left ventricular outflow tract obstruction and a small atrial septal defect. The anomalous vessel escaped detection during two right and left heart catheterizations from the right arm and

  2. Restructuring brain drain: strengthening governance and financing for health worker migration.

    Science.gov (United States)

    Mackey, Tim K; Liang, Bryan A

    2013-01-15

    Health worker migration from resource-poor countries to developed countries, also known as ''brain drain'', represents a serious global health crisis and a significant barrier to achieving global health equity. Resource-poor countries are unable to recruit and retain health workers for domestic health systems, resulting in inadequate health infrastructure and millions of dollars in healthcare investment losses. Using acceptable methods of policy analysis, we first assess current strategies aimed at alleviating brain drain and then propose our own global health policy based solution to address current policy limitations. Although governments and private organizations have tried to address this policy challenge, brain drain continues to destabilise public health systems and their populations globally. Most importantly, lack of adequate financing and binding governance solutions continue to fail to prevent health worker brain drain. In response to these challenges, the establishment of a Global Health Resource Fund in conjunction with an international framework for health worker migration could create global governance for stable funding mechanisms encourage equitable migration pathways, and provide data collection that is desperately needed.

  3. The routine use of post-operative drains in thyroid surgery: an outdated concept.

    LENUS (Irish Health Repository)

    Prichard, R S

    2010-01-01

    The use of surgical drains in patients undergoing thyroid surgery is standard surgical teaching. Life-threatening complications, arising from post-operative haematomas, mandates their utilization. There is increasing evidence to suggest that this is an outdated practice. This paper determines whether thyroid surgery can be safely performed without the routine use of drains. A retrospective review of patients undergoing thyroid surgery, over a three year period was performed and post-operative complications documented. One hundred and four thyroidectomies were performed. 63 (60.6%) patients had a partial thyroidectomy, 27 (25.9%) had a total thyroidectomy and 14 (13.5%) had a sub-total thyroidectomy. Suction drains were not inserted in any patient. A cervical haematoma did not develop in any patient in this series and no patient required re-operation. There is no evidence to suggest the routine use of surgical drains following uncomplicated thyroid surgery reduces the rate of haematoma formation or re-operation rates and indeed is now unwarranted.

  4. The Brain Drain in Mexico--A Subject for Research...or Agenda?

    Science.gov (United States)

    Aupetit, Sylvie Didou

    2006-01-01

    The purpose of this article is to analyse the present state of the discussion and data regarding the brain drain in Mexico. From current data, recent trends show certain peculiarities in the national picture, pointing to an increase in the number of free movers, and a decrease in the number of young people who obtain Mexican government…

  5. The effect of random dopant fluctuation on threshold voltage and drain current variation in junctionless nanotransistors

    International Nuclear Information System (INIS)

    Rezapour, Arash; Rezapour, Pegah

    2015-01-01

    We investigate the effect of dopant random fluctuation on threshold voltage and drain current variation in a two-gate nanoscale transistor. We used a quantum-corrected technology computer aided design simulation to run the simulation (10000 randomizations). With this simulation, we could study the effects of varying the dimensions (length and width), and thicknesses of oxide and dopant factors of a transistor on the threshold voltage and drain current in subthreshold region (off) and overthreshold (on). It was found that in the subthreshold region the variability of the drain current and threshold voltage is relatively fixed while in the overthreshold region the variability of the threshold voltage and drain current decreases remarkably, despite the slight reduction of gate voltage diffusion (compared with that of the subthreshold). These results have been interpreted by using previously reported models for threshold current variability, load displacement, and simple analytical calculations. Scaling analysis shows that the variability of the characteristics of this semiconductor increases as the effects of the short channel increases. Therefore, with a slight increase of length and a reduction of width, oxide thickness, and dopant factor, we could correct the effect of the short channel. (paper)

  6. Short-channel drain current model for asymmetric heavily/lightly ...

    Indian Academy of Sciences (India)

    The paper presents a drain current model for double gate metal oxide semiconductor field effect transistors (DG MOSFETs) based on a new velocity saturation model that accounts for short-channel velocity saturation effect independently in the front and the back gate controlled channels under asymmetric front and back ...

  7. Thermal-fluid analysis of the fill and drain operations of a cryrogenic fuel tank

    Science.gov (United States)

    Stephens, Craig A.; Hanna, Gregory J.; Gong, Leslie

    1993-01-01

    The Generic Research Cryogenic Tank was designed to establish techniques for testing and analyzing the behavior of reusable fuel tank structures subjected to cryogenic fuels and aerodynamic heating. The Generic Research Cryogenic Tank tests will consist of filling a pressure vessel to a prescribed fill level, waiting for steady-state conditions, then draining the liquid while heating the external surface to simulate the thermal environment associated with hypersonic flight. Initial tests of the Generic Research Cryogenic Tank will use liquid nitrogen with future tests requiring liquid hydrogen. Two-dimensional finite-difference thermal-fluid models were developed for analyzing the behavior of the Generic Research Cryogenic Tank during fill and drain operations. The development and results of the two-dimensional fill and drain models, using liquid nitrogen, are provided, along with results and discussion on extrapolating the model results to the operation of the full-size Generic Research Cryogenic Tank. These numerical models provided a means to predict the behavior of the Generic Research Cryogenic Tank during testing and to define the requirements for the Generic Research Cryogenic Tank support systems such as vent, drain, pressurization, and instrumentation systems. In addition, the fill model provided insight into the unexpected role of circumferential conduction in cooling the Generic Research Cryogenic Tank pressure vessel during fill operations.

  8. 7 CFR 58.416 - Cheese vats, tanks and drain tables.

    Science.gov (United States)

    2010-01-01

    ... uniform heating. The inner liner shall be minimum 16 gauge stainless steel or other equally corrosion... jacket. The outer jacket shall be constructed of stainless steel or other metal which can be kept clean... 7 Agriculture 3 2010-01-01 2010-01-01 false Cheese vats, tanks and drain tables. 58.416 Section 58...

  9. Human capital in European peripheral regions: brain - drain and brain - gain

    NARCIS (Netherlands)

    Coenen, Franciscus H.J.M.

    2004-01-01

    Project goal - The overall goal of the project is to build a legitimate transnational network to transfer ideas and experiences and implement measures to reduce brain drain and foster brain gain while reinforcing the economical and spatial development of peripheral regions in NWE. This means a

  10. Quality Education Improvement: Yemen and the Problem of the "Brain Drain"

    Science.gov (United States)

    Muthanna, Abdulghani

    2015-01-01

    This paper presents an overview of the problems that hinder improvement of the quality of education in Yemen, with a particular focus on higher education institutions. It discusses in particular the problem of the brain drain and why this phenomenon is occurring in Yemen. Semi-structured interviews with three professors at higher education…

  11. [To what extent is Mexican emigration to the United States a brain drain?].

    Science.gov (United States)

    Osborn, T N; Newton, J R

    1979-01-01

    The authors examine the problem of legal Mexican emigration to the United States, analyzing its effects on both countries. Characteristics of the Mexican emigrants are examined with respect to level of employment, salary, and employment opportunities. The total number of emigrants in professional and technical capacities is investigated in order to determine the likelihood of a brain drain from Mexico to the United States

  12. Academic Brain Drain: Impact and Implications for Public Higher Education Quality in Kenya

    Science.gov (United States)

    Odhiambo, George O.

    2013-01-01

    The flight of human capital is a phenomenon that has been of concern to academics and development practitioners for decades. Unfortunately, there is no systematic record of the number of skilled professionals that many African countries have continued to lose to the developed world. Termed the "brain drain", it represents the loss of…

  13. Umbilical vein draining into the inferior vena cava via the internal iliac vein, bypassing the liver

    Energy Technology Data Exchange (ETDEWEB)

    Currarino, G.; Stannard, M.W. (Children' s Medical Center, Dallas, TX (United States). Dept. of Radiology Texas Univ., Dallas, TX (United States). Southwestern Medical Center); Kolni, H. (Methodist Hospital, Dallas, TX (United States). Dept. of Pediatrics)

    1991-05-01

    This is the third report of an anomalous umbilical vein draining ectopically in a left pelvic vein, probably the left internal iliac, and through the inferior vena cava into the right atrium. The anomaly was encountered in a newborn infant with nonimmune hydrops fetalis, hypertrophic cardiomyopathy, multiorgan failure and possibly Noonan Syndrome. (orig.).

  14. Photoactive TiO2 Films Formation by Drain Coating for Endosulfan Degradation

    Directory of Open Access Journals (Sweden)

    Natalia Tapia-Orozco

    2013-01-01

    Full Text Available Heterogeneous photocatalysis is an advanced oxidation process in which a photoactive catalyst, such as TiO2, is attached to a support to produce free radical species known as reactive oxygen species (ROS that can be used to break down toxic organic compounds. In this study, the draining time, annealing temperature, and draining/annealing cycles for TiO2 films grown by the drain coating method were evaluated using a 23 factorial experimental design to determine the photoactivity of the films via endosulfan degradation. The TiO2 films prepared with a large number of draining/annealing cycles at high temperatures enhanced (P>0.05 endosulfan degradation and superoxide radical generation after 30 minutes of illumination with UV light. We demonstrated a negative correlation (R2=0.69; P>0.01 between endosulfan degradation and superoxide radical generation. The endosulfan degradation rates were the highest at 30 minutes with the F6 film. In addition, films prepared using conditions F1, F4, and F8 underwent an adsorption/desorption process. The kinetic reaction constants, Kapp (min−1, were 0.0101, 0.0080, 0.0055, 0.0048, and 0.0035 for F6, F2, F5, F3, and F1, respectively. The endosulfan metabolites alcohol, ether, and lactone were detected and quantified at varying levels in all photocatalytic assays.

  15. Structure of a steady drain-hole vortex in a viscous fluid

    DEFF Research Database (Denmark)

    Bøhling, Lasse; Andersen, Anders Peter; Fabre, D.

    2010-01-01

    We use direct numerical simulations to study a steady bathtub vortex in a cylindrical tank with a central drain-hole, a fiat stress-free surface and velocity prescribed at the inlet. We find that the qualitative structure of the meridional flow does not depend on the radial Reynolds number, where...

  16. State of science of phosphorus modeling in tile drained agricultural systems using APEX

    Science.gov (United States)

    Phosphorus losses through tile drained systems in agricultural landscapes may be causing the persistent eutrophication problems observed in surface water. The purpose of this paper is to evaluate the state of the science in the Agricultural Policy/Environmental eXtender (APEX) model related to surf...

  17. Long-term hydrology and water quality of a drained pine plantation in North Carolina

    Science.gov (United States)

    D.M. Amatya; R.W. Skaggs

    2011-01-01

    Long-term data provide a basis for understanding natural variability, reducing uncertainty in model inputs and parameter estimation, and developing new hypotheses. This article evaluates 21 years (1988-2008) of hydrologic data and 17 years (1988-2005) of water quality data from a drained pine plantation in eastern North Carolina. The plantation age was 14 years at the...

  18. Hydrobiogeochemical interactions in 'anoxic' limestone drains for neutralization of acidic mine drainage

    Science.gov (United States)

    Robbins, E.I.; Cravotta, C.A.; Savela, C.E.; Nord, G.L.

    1999-01-01

    Processes affecting neutralization of acidic coal mine drainage were evaluated within 'anoxic' limestone drains (ALDs). Influents had pH???3.5 and dissolved oxygen treatment step is indicated to promote Al removal before diverting acidic mine water into alkalinity-producing materials. ?? 1998 Elsevier Science Ltd.

  19. An analysis of molten-corium-induced failure of drain pipes in BWR Mark 2 containments

    International Nuclear Information System (INIS)

    Taleyarkhan, R.P.; Podowski, M.Z.

    1991-01-01

    This study has focused on mechanistic simulation and analysis of potential failure modes for inpedestal drywell drain pipes in the Limerick boiling water reactor (BWR) Mark 2 containment. Physical phenomena related to surface tension breakdown, heatup, melting, ablation, crust formation and failure, and core material relocation into drain pipes with simultaneous melting of pipe walls were modeled and analyzed. The results of analysis have been used to assess the possibility of drain pipe failure and the resultant loss of pressure-suppression capability. Estimates have been made for the timing and amount of molten corium released to the wetwell. The study has revealed that significantly different melt progression sequences can result depending upon the failure characteristics of the frozen metallic crust which forms over the drain cover during the initial stages of debris pour. Another important result is that it can take several days for the molten fuel to ablate the frozen metallic debris layer -- if the frozen layer has cooled below 1100 K before fuel attack. 10 refs., 3 figs., 4 tabs

  20. Characterization of Drain Surface Water: Environmental Profile, Degradation Level and Geo-statistic Monitoring

    International Nuclear Information System (INIS)

    Mumtaz, M.W.; Raza, M.A.; Ahmed, Z.; Abbas, M.N.; Hussain, M.

    2015-01-01

    The physico-chemical characterization of the surface water. Samples was carried out collected from nine sampling points of drain passing by the territory of Hafizabad city, Punjab, Pakistan. The water of drain is used by farmers for irrigation purposes in nearby agricultural fields. Twenty water quality parameters were evaluated in three turns and the results obtained were compared with the National Environmental Quality Standards (NEQS) municipal and industrial effluents prescribed limits. The highly significant difference (p<0.01) was recorded for the content of phenols, carbonyl compounds, cyanides, dissolved oxygen, biological oxygen demand, total soluble salts, total dissolved salts, nitrates and sulphates, whereas, the concentration of magnesium, potassium and oil and grease differed significantly (p<0.05) with respect to the sampling points on average basis. Non-significant difference (p>0.05) was noted for temperature, pH, electrical conductivity, hardness, calcium, sodium, chemical oxygen demand and chloride among water samples from different sampling points. Furthermore, the experimental results of different water quality parameters studied at nine sampling points of the drain were used and interpolated in ArcGIS 9.3 environment system using kriging techniques to obtain calculated values for the remaining locations of the Drain. (author)

  1. Interactions between soil thermal and hydrological dynamics in the response of Alaska ecosystems to fire disturbance

    Science.gov (United States)

    Yi, Shuhua; McGuire, A. David; Harden, Jennifer; Kasischke, Eric; Manies, Kristen L.; Hinzman, Larry; Liljedahl, Anna K.; Randerson, J.; Liu, Heping; Romanovsky, Vladimir E.; Marchenko, Sergey S.; Kim, Yongwon

    2009-01-01

    Soil temperature and moisture are important factors that control many ecosystem processes. However, interactions between soil thermal and hydrological processes are not adequately understood in cold regions, where the frozen soil, fire disturbance, and soil drainage play important roles in controlling interactions among these processes. These interactions were investigated with a new ecosystem model framework, the dynamic organic soil version of the Terrestrial Ecosystem Model, that incorporates an efficient and stable numerical scheme for simulating soil thermal and hydrological dynamics within soil profiles that contain a live moss horizon, fibrous and amorphous organic horizons, and mineral soil horizons. The performance of the model was evaluated for a tundra burn site that had both preburn and postburn measurements, two black spruce fire chronosequences (representing space-for-time substitutions in well and intermediately drained conditions), and a poorly drained black spruce site. Although space-for-time substitutions present challenges in model-data comparison, the model demonstrates substantial ability in simulating the dynamics of evapotranspiration, soil temperature, active layer depth, soil moisture, and water table depth in response to both climate variability and fire disturbance. Several differences between model simulations and field measurements identified key challenges for evaluating/improving model performance that include (1) proper representation of discrepancies between air temperature and ground surface temperature; (2) minimization of precipitation biases in the driving data sets; (3) improvement of the measurement accuracy of soil moisture in surface organic horizons; and (4) proper specification of organic horizon depth/properties, and soil thermal conductivity.

  2. A questionnaire about radiation safety management of the draining-water system at nuclear medicine facilities

    International Nuclear Information System (INIS)

    Shizukuishi, Kazuya; Narita, Hiroto

    2004-01-01

    We conducted a questionnaire survey about radiation-safety management condition in Japanese nuclear medicine facilities to make materials of proposition for more reasonable management of medical radioactive waste. We distributed a questionnaire to institutions equipped with Nuclear Medicine facilities. Of 1,125 institutions, 642 institutes (52.8%) returned effective answers. The questionnaire covered the following areas: scale of an institution, presence of enforcement of radiotherapy, system of a tank, size and number of each tank, a form of draining-water system, a displacement in a radioactive rays management area, a measurement method of the concentration of medical radioactive waste in draining water system, planned and used quantity of radioisotopes for medical examination and treatment, an average displacement of hospital for one month. In most institutions, a ratio of dose limitation of radioisotope in draining-water system was less than 1.0, defined as an upper limitation in ordinance. In 499 hospitals without facilities of hospitalization for unsealed radioisotope therapy, 473 hospitals reported that sum of ratios of dose limits in a draining-water system was less than 1.0. It was calculated by used dose of radioisotope and monthly displacement from hospital, on the premise that all used radioisotope entered in the general draining-water system. When a drainage including radioactivity from a controlled area join with that from other area before it flows out of a institution, it may be diluted and its radioactive concentration should be less than its upper limitation defined in the rule. Especially, in all institutions with a monthly displacement of more than 25,000 m 3 , the sum of ratio of the concentration of each radionuclide to the concentration limit dose calculated by used dose of radioisotope, indicated less than 1.0. (author)

  3. Effect of One versus Two Drain Insertion on Postoperative Seroma Formation after Modified Radical Mastectomy

    Directory of Open Access Journals (Sweden)

    farzaneh ebrahimifard

    2016-04-01

    Full Text Available Background: Modified radical mastectomy (MRM is still one of globally accepted surgical techniques for breast cancer and in some selected patient is the gold standard type of surgery. The most frequent complication of this procedure is seroma under skin flaps or in the axilla as reported as much as 30% in some studies. The use of closed suction drainage system to reduce the incidence of this complication has been routinely accepted by surgeons; however, length of catheter stay and the number of catheters inserted in the wound are still controversial. The present study compares the results of single versus double drain insertion in patients undergoing MRM for breast cancer.Materials and Methods: The study was conducted on 100 women with breast cancer who were candidate for MRM surgery during 2007-2010 referred to Modarres hospital, Tehran, Iran as a randomized group matched controlled trial.Results: There was no significant difference between the two groups in terms of age, BMI, and tumor weight (P=0.406 (Table 1. Similarly, the difference between the two groups was insignificant in tumor size (T and number of lymph nodes involved (P=0.145. There was no significant difference between the two groups in timing of axillary drain removal (P=0.064. No significant differences were observed between the two groups in mean aspirated fluid (P=0.071 and mean aspirated sera (P=0.484 after removal of drains.Conclusion: This study revealed one drain insertion in MRM surgery is as effective as two drain and probably less morbidity and cost.

  4. Evapotranspiration from drained wetlands: drivers, modeling, storage functions, and restoration implications

    Science.gov (United States)

    Shukla, S.; Wu, C. L.; Shrestha, N.

    2017-12-01

    Abstract Evapotranspiration (ET) is a major component of wetland and watershed water budgets. The effect of wetland drainage on ET is not well understood. We tested whether the current understanding of insignificant effect of drainage on ET in the temperate region wetlands applies to those in the sub-tropics. Eddy covariance (EC) based ET measurements were made for two years at two previously drained and geographically close wetlands in the Everglades region of Florida. One wetland was significantly drained with 97% of its storage capacity lost. The other was a more functional wetland with 42% of storage capacity lost. Annual average ET at the significantly drained wetland was 836 mm, 34% less than the function wetland (1271 mm) and the difference was statistically significant (p = 0.001). Such differences in wetland ET in the same climatic region have not been observed. The difference in ET was mainly due to drainage driven differences in inundation and associated effects on net radiation (Rn) and local relative humidity. Two daily ET models, a regression (r2 = 0.80) and a Relevance Vector Machine (RVM) model (r2 = 0.84), were developed with the latter being more robust. These models, when used in conjunction with hydrologic models, improved ET predictions for drained wetlands. Predictions from an integrated model showed that more intensely drained wetlands at higher elevation should be targeted for restoration of downstream flows (flooding) because they have the ability to loose higher water volume through ET which increases available water storage capacity of wetlands. Daily ET models can predict changes in ET for improved evaluation of basin-scale effects of restoration programs and climate change scenarios.

  5. Evapotranspiration from drained wetlands with different hydrologic regimes: Drivers, modeling, and storage functions

    Science.gov (United States)

    Wu, Chin-Lung; Shukla, Sanjay; Shrestha, Niroj K.

    2016-07-01

    We tested whether the current understanding of insignificant effect of drainage on evapotranspiration (ET) in the temperate region wetlands applies to those in the subtropics. Hydro-climatic drivers causing the changes in drained wetlands were identified and used to develop a generic model to predict wetland ET. Eddy covariance (EC)-based ET measurements were made for two years at two differently drained but close by wetlands, a heavily drained wetland (SW) (97% reduced surface storage) and a more functional wetland (DW) (42% reduced storage). Annual ET for more intensively drained SW was 836 mm, 34% less than DW (1271 mm) and the difference was significant (p = 0.001). This difference was mainly due to drainage driven differences in inundation and associated effects on net radiation (Rn) and local relative humidity. Two generic daily ET models, a regression model (MSE = 0.44 mm2, R2 = 0.80) and a machine learning-based Relevance Vector Machine (RVM) model (MSE = 0.36 mm2, R2 = 0.84), were developed with the latter being more robust. The RVM model can predict changes in ET for different restoration scenarios; a 1.1 m rise in drainage level showed 7% increase ET (18 mm) at SW while the increase at DW was negligible. The additional ET, 28% of surface flow, can enhance water storage, flood protection, and climate mitigation services at SW compared to DW. More intensely drained wetlands at higher elevation should be targeted for restoration for enhanced storage through increased ET. The models developed can predict changes in ET for improved evaluation of basin-scale effects of restoration programs and climate change scenarios.

  6. A synthesis of the impacts of ditch network maintenance on the quantity and quality of runoff from drained boreal peatland forests.

    Science.gov (United States)

    Nieminen, Mika; Palviainen, Marjo; Sarkkola, Sakari; Laurén, Ari; Marttila, Hannu; Finér, Leena

    2017-10-29

    Drained peatlands are an important source of forest biomass in boreal regions and ditch network maintenance (DNM) operations may be needed to restore the drainage functions of ditches. By reviewing the available literature, as well as utilizing an existing hydrological model and analyzing the characteristics of eroded sediments, we assessed the impacts of DNM on runoff and exports of suspended solids (SS), dissolved organic carbon (DOC), nitrogen (N), and phosphorus (P). In general, DNM had minor impact on runoff and dissolved N and P, and it decreased rather than increased DOC exports. To increase the understanding of the hydrochemical impacts of DNM, future research should focus on the characteristics of SS and particulate nutrient exports. A major gap in knowledge is also the very limited regional representativeness of the available studies. High erosion risk in the ditches reaching the mineral soil below peat should be acknowledged when planning mitigation measures.

  7. Leaching of viruses and other microorganisms naturally occurring in pig slurry to tile drains on a well-structured loamy field in Denmark

    DEFF Research Database (Denmark)

    Krog, Jesper Schak; Forslund, Anita; Larsen, Lars Erik

    2017-01-01

    The amount of animal manure used in modern agriculture is increasing due to the increase in global animal production. Pig slurry is known to contain zoonotic bacteria such as E. coli, Salmonella spp. and Campylobacter spp., and viruses such as hepatitis E virus and group A rotavirus. Coliform...... sets out to investigate the leaching potential of six different microorganisms: E. coli and Enterococcus spp. (detected by colony assay), somatic coliphages (using plaque assays), and hepatitis E virus, porcine circovirus type 2, and group A rotavirus (by real-time polymerase chain reaction). All six...... microorganisms leached through the soil entering the tile drains situated at 1-m depth the first day following pig slurry application. The leaching pattern of group A rotavirus differed substantially from the pattern for somatic coliphages, which are otherwise used as indicators for virus contamination...

  8. REVIEW OF MODERN TECHNOLOGIES OF REINFORCEMENT AND STABILIZATION OF SOFT SOILS

    Directory of Open Access Journals (Sweden)

    Romanov Nikita Valer’evich

    2018-05-01

    Full Text Available Subject: description of the current situation in technologies of soil improvement, namely mechanical and hydraulic consolidation of soils and vertical reinforcement of soils for different types of soft soils. Research objectives: demonstration of modern possibilities and approaches to the design and construction of improved soils. Materials and methods: in this paper, we consider such technologies of ground improvement as dynamic compaction, hydraulic consolidation (vertical drain consolidation, Menard vacuum consolidation, vertical reinforcement of soils (CMC - controlled modulus columns. Results: the result of the study is an intuitive representation of the applicability of described technologies for various types of soft soils. Conclusions: the technologies of ground improvement considered in this article are an effective alternative to both pile foundations and soil replacement. To this day, industrial implementation of soil improvement technologies has proved its applicability, efficiency and competitiveness.

  9. Outcomes of Transhiatal and Intercostal Pleural Drain After Ivor Lewis Esophagectomy: Comparative Analysis of Two Consecutive Patient Cohorts.

    Science.gov (United States)

    Asti, Emanuele; Bernardi, Daniele; Bonitta, Gianluca; Bonavina, Luigi

    2018-05-01

    In a previous proof of concept study, transhiatal pleural drain has been shown to be safe and effective after hybrid Ivor Lewis esophagectomy. Aim of this study was to compare the short-term outcomes of transhiatal and intercostal pleural drainage. This is an observational retrospective cohort study. Two methods of pleural drainage were compared in patients undergoing hybrid Ivor Lewis esophagectomy. Patients treated with a transhiatal drain connected to a vacuum bag were compared to a historical cohort of patients treated with the conventional intercostal drain connected to underwater seal and suction. Postoperative morbidity, total and daily drainage output, serum albumin levels, and total dose of paracetamol and ketorolac administered on demand were recorded. Between January 2014 and December 2016, 50 patients with transhiatal drain and 50 with intercostal drains met the criteria for inclusion in the study. Demographic and clinicopathological variables were similar in the two groups. There was no statistically significant difference in the rate of postoperative complications. The total volume of drain output and the serum albumin levels were similar in the two groups. The total dose of ketorolac was significantly reduced in patients with transhiatal drain (P pleural drainage connected to a portable vacuum system could safely replace the intercostal drain after hybrid Ivor Lewis esophagectomy. It has the potential to reduce postoperative pain and use of nonsteroidal anti-inflammatory drugs, and to enhance recovery from surgery.

  10. Disinfection of drain water of tomato by means of UV radiation and slow sand filtration in real greenhouse circumstances.

    Science.gov (United States)

    De Rocker, E; Goen, K; Van Poucke, K

    2006-01-01

    The efficiency of the disinfection of drain water was tested at 11 greenhouses with tomato cultivation on rockwool substrate in Flanders (Belgium) by means of mycological analysis. In addition the presence of phytopathogenic fungi in the drain water was analysed at 2 supplementary greenhouses with recirculation without disinfection.

  11. Viscosity-dependent drain current noise of AlGaN/GaN high electron mobility transistor in polar liquids

    International Nuclear Information System (INIS)

    Fang, J. Y.; Hsu, C. P.; Kang, Y. W.; Fang, K. C.; Kao, W. L.; Yao, D. J.; Chen, C. C.; Li, S. S.; Yeh, J. A.; Wang, Y. L.; Lee, G. Y.; Chyi, J. I.; Hsu, C. H.; Huang, Y. F.; Ren, F.

    2013-01-01

    The drain current fluctuation of ungated AlGaN/GaN high electron mobility transistors (HEMTs) measured in different fluids at a drain-source voltage of 0.5 V was investigated. The HEMTs with metal on the gate region showed good current stability in deionized water, while a large fluctuation in drain current was observed for HEMTs without gate metal. The fluctuation in drain current for the HEMTs without gate metal was observed and calculated as standard deviation from a real-time measurement in air, deionized water, ethanol, dimethyl sulfoxide, ethylene glycol, 1,2-butanediol, and glycerol. At room temperature, the fluctuation in drain current for the HEMTs without gate metal was found to be relevant to the dipole moment and the viscosity of the liquids. A liquid with a larger viscosity showed a smaller fluctuation in drain current. The viscosity-dependent fluctuation of the drain current was ascribed to the Brownian motions of the liquid molecules, which induced a variation in the surface dipole of the gate region. This study uncovers the causes of the fluctuation in drain current of HEMTs in fluids. The results show that the AlGaN/GaN HEMTs may be used as sensors to measure the viscosity of liquids within a certain range of viscosity

  12. Comparison consequences of Jackson-Pratt drain versus chest tube after coronary artery bypass grafting: A randomized controlled clinical trial.

    Science.gov (United States)

    Mirmohammad-Sadeghi, Mohsen; Pourazari, Pejman; Akbari, Mojtaba

    2017-01-01

    Chest tubes are used in every case of coronary artery bypass grafting (CABG) to evacuate shed blood from around the heart and lungs. This study was designed to assess the effective of Jackson-Pratt drain in compare with conventional chest drains after CABG. This was a randomized controlled trial that conducted on 218 patients in Chamran hospital from February to December 2016. Eligible patients were randomized in a 1:1 ratio. Jackson-Pratt drain group had 109 patients who received a chest tube insertion in the pleural space of the left lung and a Jackson-Pratt drain in mediastinum, and Chest tube drainage group had 109 patients who received double chest tube insertion in the pleural space of the left lung and the mediastinum. The incidence of pleural effusions in Jackson-Pratt drain group and chest tube group were not statistically different. The pain score at 2-h in Drain group was significantly higher than chest tube group ( P = 0.001), but the trend of pain score between groups was not significantly different ( P = 0.097). The frequency of tamponade and atrial fibrillation (AF) were significantly lower in Jackson-Pratt drain group ( P drain is equally effective for preventing cardiac tamponade, pleural effusions, and pain intensity in patients after CABG when compared with conventional chest tubes, but was significantly superior regarding efficacy to hospital and Intensive Care Unit length of stay and the incidence of AF.

  13. Simulation of water movement and isoproturon behaviour in a heavy clay soil using the MACRO model

    Directory of Open Access Journals (Sweden)

    T. J. Besien

    1997-01-01

    Full Text Available In this paper, the dual-porosity MACRO model has been used to investigate methods of reducing leaching of isoproturon from a structured heavy clay soil. The MACRO model was applied to a pesticide leaching data-set generated from a plot scale experiment on a heavy clay soil at the Oxford University Farm, Wytham, England. The field drain was found to be the most important outflow from the plot in terms of pesticide removal. Therefore, this modelling exercise concentrated on simulating field drain flow. With calibration of field-saturated and micropore saturated hydraulic conductivity, the drain flow hydrographs were simulated during extended periods of above average rainfall, with both the hydrograph shape and peak flows agreeing well. Over the whole field season, the observed drain flow water budget was well simulated. However, the first and second drain flow events after pesticide application were not simulated satisfactorily. This is believed to be due to a poor simulation of evapotranspiration during a period of low rainfall around the pesticide application day. Apart from an initial rapid drop in the observed isoproturon soil residue, the model simulated isoproturon residues during the 100 days after pesticide application reasonably well. Finally, the calibrated model was used to show that changes in agricultural practice (deep ploughing, creating fine consolidated seed beds and organic matter applications could potentially reduce pesticide leaching to surface waters by up to 60%.

  14. The fabrication of carbon nanotube field-effect transistors with semiconductors as the source and drain contact materials.

    Science.gov (United States)

    Xiao, Z; Camino, F E

    2009-04-01

    Sb(2)Te(3) and Bi(2)Te(2)Se semiconductor materials were used as the source and drain contact materials in the fabrication of carbon nanotube field-effect transistors (CNTFETs). Ultra-purified single-walled carbon nanotubes (SWCNTs) were ultrasonically dispersed in N-methyl pyrrolidone solvent. Dielectrophoresis was used to deposit and align SWCNTs for fabrication of CNTFETs. The Sb(2)Te(3)- and Bi(2)Te(2)Se-based CNTFETs demonstrate p-type metal-oxide-silicon-like I-V curves with high on/off drain-source current ratio at large drain-source voltages and good saturation of drain-source current with increasing drain-source voltage. The fabrication process developed is novel and has general meaning, and could be used for the fabrication of SWCNT-based integrated devices and systems with semiconductor contact materials.

  15. Method of making a self-aligned schottky metal semi-conductor field effect transistor with buried source and drain

    International Nuclear Information System (INIS)

    Bol, I.

    1984-01-01

    A semi-conductor structure and particularly a high speed VLSI Self-Aligned Schottky Metal Semi-Conductor Field Effect Transistor with buried source and drain, fabricated by the ion implantation of source and drain areas at a predetermined range of depths followed by very localized laser annealing to electrically reactivate the amorphous buried source and drain areas thereby providing effective vertical separation of the channel from the buried source and drain respectively. Accordingly, spatial separations between the self-aligned gate-to-drain, and gate-to-source can be relatively very closely controlled by varying the doping intensity and duration of the implantation thereby reducing the series resistance and increasing the operating speed

  16. Soil cadmium mobility as a consequence of sewage sludge disposal

    Energy Technology Data Exchange (ETDEWEB)

    Lamy, I. [Station de Science du Sol, Versailles (France); Bourgeois, S.; Bermond, A. [Institut National Agronomique, Paris (France)

    1993-10-01

    Anaerobically digested liquid sewage sludge was applied as a single treatment to a loamy hydromorphic drained soil, characteristic of agricultural soils in the North of France, at a rate of 11 Mg of dry solids ha{sup -1}. Total Cd concentrations of drainage waters for both amended and unamended plots were monitored at selected times to follow the mobility of Cd after sludge disposal. The drained ground-water of the plot that exhibited the highest discharge of sludge soluble organic matter (SSOM) exhibited about twice the Cd levels of the control plot during the first few weeks following sludge disposal (average of 3 and 1.5 {mu}g L{sup -1} respectively). Laboratory experiments were conducted to provide estimates of the relative binding strength of Cd-soil interactions as well as Cd-SSOM interactions. The behavior of Cd in a mixed sludge-soil system showed that the addition of sludge soluble organic matter to the soil led to a decrease in the sorption of this cation across the pH range between 5 and 7. The laboratory studies highlighted the role of soluble organic matter in soil Cd speciation, and can be used to speculate on the perturbations induced by high levels of sludge soluble organic matter introduced into a soil.

  17. Relating soil microbial activity to water content and tillage-induced differences in soil structure

    DEFF Research Database (Denmark)

    Schjønning, Per; Thomsen, Ingrid Kaag; Petersen, Søren O

    2011-01-01

    Several studies have identified optima in soil water content for aerobic microbial activity, and this has been ascribed to a balance between gas and solute diffusivity as limiting processes. We investigated the role of soil structure, as created by different tillage practices (moldboard ploughing......, MP, or shallow tillage, ST), in regulating net nitrification, applied here as an index of aerobic microbial activity. Intact soil cores were collected at 0–4 and 14–18 cm depth from a fine sandy (SAND) and a loamy (LOAM) soil. The cores were drained to one of seven matric potentials ranging from − 15...... content to a maximum and then decreased. This relationship was modelled with a second order polynomium. Model parameters did not show any tillage effect on the optimum water content, but the optimum coincided with a lower matric potential in ST (SAND: − 140 to –197 hPa; LOAM: − 37 to − 65 hPa) than in MP...

  18. Soil pollution and soil protection

    OpenAIRE

    Haan, de, F.A.M.; Visser-Reijneveld, M.I.

    1996-01-01

    This book was compiled from lecture handouts prepared for the international postgraduate course on soil quality, entitled 'Soil Pollution and Soil Protection' given jointly by the universities of Wageningen (The Netherlands), Gent and Leuven (Belgium), under the auspices of the international Training Centre (PHLO) of Wageningen Agricultural University.Of the three environmental compartments air, water and soil, it is soil that varies most in composition under natural conditions. The effects o...

  19. Prefabricated Vertical Drain (PVD) and Deep Cement Mixing (DCM)/Stiffened DCM (SDCM) techniques for soft ground improvement

    Science.gov (United States)

    Bergado, D. T.; Long, P. V.; Chaiyaput, S.; Balasubramaniam, A. S.

    2018-04-01

    Soft ground improvement techniques have become most practical and popular methods to increase soil strength, soil stiffness and reduce soil compressibility including the soft Bangkok clay. This paper focuses on comparative performances of prefabricated vertical drain (PVD) using surcharge, vacuum and heat preloading as well as the cement-admixed clay of Deep Cement Mixing (DCM) and Stiffened DCM (SDCM) methods. The Vacuum-PVD can increase the horizontal coefficient of consolidation, Ch, resulting in faster rate of settlement at the same magnitudes of settlement compared to Conventional PVD. Several field methods of applying vacuum preloading are also compared. Moreover, the Thermal PVD and Thermal Vacuum PVD can increase further the coefficient of horizontal consolidation, Ch, with the associated reduction of kh/ks values by reducing the drainage retardation effects in the smear zone around the PVD which resulted in faster rates of consolidation and higher magnitudes of settlements. Furthermore, the equivalent smear effect due to non-uniform consolidation is also discussed in addition to the smear due to the mechanical installation of PVDs. In addition, a new kind of reinforced deep mixing method, namely Stiffened Deep Cement Mixing (SDCM) pile is introduced to improve the flexural resistance, improve the field quality control, and prevent unexpected failures of the Deep Cement Mixing (DCM) pile. The SDCM pile consists of DCM pile reinforced with the insertion of precast reinforced concrete (RC) core. The full scale test embankment on soft clay improved by SDCM and DCM piles was also analysed. Numerical simulations using the 3D PLAXIS Foundation finite element software have been done to understand the behavior of SDCM and DCM piles. The simulation results indicated that the surface settlements decreased with increasing lengths of the RC cores, and, at lesser extent, increasing sectional areas of the RC cores in the SDCM piles. In addition, the lateral movements

  20. Spatial and temporal distribution of mosquitoes in underground storm drain systems in Orange County, California.

    Science.gov (United States)

    Su, Tianyun; Webb, James P; Meyer, Richard P; Mulla, Mir S

    2003-06-01

    Underground storm drain systems in urban areas of Orange County include thousands of miles of gutters and underground pipelines, plus hundreds of thousands of catch basins and manhole chambers, all of which drain runoff water from residential, business and commercial establishments as well as highways and streets. These systems serve as major developmental and resting sites for anthropophilic and zoophilic mosquitoes. Investigations on spatial and temporal distribution of mosquitoes in these systems were conducted during November 1999 to October 2001. Immature mosquitoes were sampled by dipper or dipping net and adult mosquitoes by non-attractive CDC traps in manhole chambers, catch basins and a large drain. Culex quinquefasciatus Say prevailed at all 15 structures of the study in 4 cities of Orange County as the predominant species (> 99.9%). Larvae and pupae were present from April to October, peaking from May to September. The population density of adults was the lowest in February with 2 peaks of abundance occurring from May to July and from September to October. Manhole chambers and catch basins harbored more mosquitoes than did the large drain. Minimum and maximum temperatures during a 24 h sampling period was an important factor influencing adult mosquito activity and catches; more mosquitoes were caught in traps when it was warmer, especially when the minimum temperatures were higher. The proportion of females to males in general increased during winter and early spring an ddeclined during summer. The proportion of gravid females to empty females was higher during the winter than in summer. Other dipteran taxa such as psychodid moth flies and chironomid midges exhibited somewhat similar seasonal patterns as did mosquito populations. Average water temperature was relatively stable throughout the year, and water quality in underground drain systems was characterized by low dissolved oxygen, coupled with above normal electrical conductivity and salinity levels

  1. Solarization soil

    International Nuclear Information System (INIS)

    Abou Ghraibe, W.

    1995-01-01

    Solar energy could be used in pest control, in soil sterilization technology. The technique consists of covering humid soils by plastic films steadily fixed to the soil. Timing must be in summer during 4-8 weeks, where soil temperature increases to degrees high enough to control pests or to produce biological and chemical changes. The technique could be applied on many pests soil, mainly fungi, bacteria, nematods, weeds and pest insects. The technique could be used in greenhouses as well as in plastic film covers or in orchards where plastic films present double benefits: soil sterilization and production of black mulch. Mechanism of soil solarization is explained. Results show that soil solarization can be used in pest control after fruit crops cultivation and could be a method for an integrated pest control. 9 refs

  2. Brain drain

    International Nuclear Information System (INIS)

    Trepanier, Chris.

    1991-01-01

    By the end of the century, Canada may face a severe shortage of highly qualified personnel, particularly scientists and engineers. The causes are as follows: a declining birthrate, less immigration and more emigration of qualified people, fewer high-school graduates, waning interest in science and technology especially among women, poor teaching, and low educational standards. The Canadian government has formed science culture Canada, a program that funds activities designed to raise public appreciation and knowledge of science and technology

  3. Brain Drain

    Directory of Open Access Journals (Sweden)

    Mark Cripsin Miller

    2006-04-01

    Full Text Available Ce texte, qui sera publié dans la revue Context (n°9 et que Mark Crispin Miller et l’éditeur nous ont généreusement permis de reproduire, est un papier d’humeur qui tente de relier deux aspects de la culture américaine, à savoir d’un côté la liberté de la parole « démocratique» auquel le médium d’internet a donné une nouvelle dimension, et de l’autre l’anti‑intellectualisme — vrai ou supposé — de cette même culture. En cela, il touche à un débat fondamental pour l’étude des Etats‑Unis. Ce premier numéro de TransatlanticA, du portrait de Tocqueville à la peinture américaine du XIXe siècle exposée à Giverny, lui fait une large place.

  4. Hemovac drain

    Science.gov (United States)

    ... plastic trash bag. Inspect your skin where the drainage tube comes out. Look for any new redness, swelling, ... a new bandage over the skin where the drainage tube comes out. Tape the bandage to your skin ...

  5. Ubuntunet Alliance: A Collaborative Research Platform for Sharing of Technological Tools for Eradication of Brain Drain

    Directory of Open Access Journals (Sweden)

    Jameson Mbale

    2012-12-01

    Full Text Available The UbuntuNet Alliance Alliance is well-placed to facilitate interaction between education and research institutions and the African academic and researcher in the Diaspora so that together they can strengthen research that will exploit new technological tools and increase the industrial base. It is envisaged that the Alliance will become an important vehicle for linkages that will facilitate repatriation of scientific knowledge and skills to Africa and even help reduce and eventually eradicate the brain drain which has taken so many excellent intellectuals to the developed world. As organisational vehicles for inter-institutional collaboration both established and emerging NRENs can play a critical role in reversing these trends and in mitigating what appears to be the negative impact of the brain drain.

  6. Cellular dynamics in the draining lymph nodes during sensitization and elicitation phases of contact hypersensitivity

    DEFF Research Database (Denmark)

    Larsen, Jeppe Madura; Geisler, Carsten; Nielsen, Martin Weiss

    2007-01-01

    BACKGROUND: The different role of various immunological effector cells in contact hypersensitivity (CHS) is receiving increased attention. During the past decade, the involvement of different cell types in CHS has been investigated by the use of antibody-induced depletion of specific subtypes...... of immunological cells and by studying knockout mice lacking one or more of these immunological cell populations. OBJECTIVES: To develop a method for studying the collective cellular dynamics of immune cells in the draining lymph nodes during CHS in intact animals. PATIENTS/METHODS: Mice were sensitized and....../or challenged with 2,4-dinitrofluorobenzene or oxazolone. Using multi-parameter flow cytometry we determined the proliferation, activation state, and absolute number of helper T cells, cytotoxic T cells, B cells, and natural killer cells in the draining lymph nodes. RESULTS: The presented method can be applied...

  7. Catheters, wires, tubes and drains on postoperative radiographs of pediatric cardiac patients: the whys and wherefores

    Energy Technology Data Exchange (ETDEWEB)

    Teele, Sarah A.; Thiagarajan, Ravi R. [Children' s Hospital Boston, Department of Cardiology, Boston, MA (United States); Harvard Medical School, Department of Pediatrics, Boston, MA (United States); Emani, Sitaram M. [Children' s Hospital Boston, Department of Cardiac Surgery, Boston, MA (United States); Harvard Medical School, Department of Surgery, Boston, MA (United States); Teele, Rita L. [Harvard Medical School, Department of Radiology, Boston, MA (United States); Starship Children' s Hospital, Department of Radiology, Grafton (New Zealand)

    2008-10-15

    Surgical treatment of congenital heart disease has advanced dramatically since the first intracardiac repairs in the mid-20th century. Previously inoperable lesions have become the focus of routine surgery and patients are managed successfully in intensive care units around the world. As a result, increasing numbers of postoperative images are processed by departments of radiology in children's hospitals. It is important that the radiologist accurately documents and describes the catheters, wires, tubes and drains that are present on the chest radiograph. This article reviews the reasons for the placement and positioning of perioperative equipment in children who have surgical repair of atrial septal defect, ventricular septal defect or transposition of the great arteries. Also included are a brief synopsis of each cardiac anomaly, the surgical procedure for its correction, and an in-depth discussion of the postoperative chest radiograph including illustrations of catheters, wires, tubes and drains. (orig.)

  8. Hydrobiogeochemical interactions in 'anoxic' limestone drains for neutralization of acidic mine drainage

    Science.gov (United States)

    Robbins, E.I.; Cravotta, C.A.; Savela, C.E.; Nord, G.L.

    1999-01-01

    Processes affecting neutralization of acidic coal mine drainage were evaluated within 'anoxic' limestone drains (ALDs). Influents had pH???3.5 and dissolved oxygen Al3+ and Fe3+ compounds. Cleavage mounts of calcite and gypsum that were suspended within the ALDs and later examined microscopically showed dissolution features despite coatings by numerous bacteria, biofilms, and Fe-Al-Si precipitates. In the drain exhibiting the greatest flow reduction, Al-hydroxysulfates had accumulated on limestone surfaces and calcite etch points, thus causing the decline in transmissivity and dissolution. Therefore, where Al loadings are high and flow rates are low, a pre-treatment step is indicated to promote Al removal before diverting acidic mine water into alkalinity-producing materials. ?? 1998 Elsevier Science Ltd.

  9. Optimal chest drain size: the rise of the small-bore pleural catheter.

    Science.gov (United States)

    Fysh, Edward T H; Smith, Nicola A; Lee, Y C Gary

    2010-12-01

    Drainage of the pleural space is not a modern concept, but the optimal size of chest drains to use remains debated. Conventional teaching advocates blunt dissection and large-bore tubes; but in recent years, small-bore catheters have gained popularity. In the absence of high-quality randomized data, this review summarizes the available literature on the choice of chest drains. The objective data supporting the use of large-bore tubes is scarce in most pleural diseases. Increasing evidence shows that small-bore catheters induce less pain and are of comparable efficacy to large-bore tubes, including in the management of pleural infection, malignant effusion, and pneumothoraces. The onus now is on those who favor large tubes to produce clinical data to justify the more invasive approach. © Thieme Medical Publishers.

  10. Canine scent detection and microbial source tracking of human waste contamination in storm drains.

    Science.gov (United States)

    Van De Werfhorst, Laurie C; Murray, Jill L S; Reynolds, Scott; Reynolds, Karen; Holden, Patricia A

    2014-06-01

    Human fecal contamination of surface waters and drains is difficult to diagnose. DNA-based and chemical analyses of water samples can be used to specifically quantify human waste contamination, but their expense precludes routine use. We evaluated canine scent tracking, using two dogs trained to respond to the scent of municipal wastewater, as a field approach for surveying human fecal contamination. Fecal indicator bacteria, as well as DNA-based and chemical markers of human waste, were analyzed in waters sampled from canine scent-evaluated sites (urban storm drains and creeks). In the field, the dogs responded positively (70% and 100%) at sites for which sampled waters were then confirmed as contaminated with human waste. When both dogs indicated a negative response, human waste markers were absent. Overall, canine scent tracking appears useful for prioritizing sampling sites for which DNA-based and similarly expensive assays can confirm and quantify human waste contamination.

  11. Miniinvasive paracentetic drain surgical interventions under ultrasonic control concerning liquid formations of abdominal cavity

    Directory of Open Access Journals (Sweden)

    G.I. Ohrimenko

    2013-08-01

    Full Text Available Entry. Presently miniinvasive surgical interventions under ultrasonic control became the method of choice in treatment of quite a number of abdominal and retroperitoneal organs diseases, and their complications. These operations have a row of advantages, as compared to open and laparoscopic ones: comparative simplicity, insignificant infecting of abdominal region, least of intra- and postoperative complications. Actuality of problem is conditioned by that indications to the use of paracentetic drain surgical interventions, most optimal methods of preoperative diagnostic, features of postoperative treatment of patients remain not enough studied. Research aim. To study the results of diagnostics and treatment of patients with liquid formations of abdominal cavity that were exposed to miniinvasive surgical interventions under ultrasonic control and, on the basis of it, to work out an optimal curative diagnostic algorithm. Materials and research methods. The results of treatment of 25 patients with liquid formations of abdominal cavity are analyzed. They were submitted to miniinvasive paracentetic drain surgical interventions under ultrasonic control. The pseudocysts of pancreas were in 16 patients, abscesses of abdominal cavity – in 2 patients. Research results. Intraoperative complications were not marked. Postoperative complications were observed in 5 patients. Among them there were inadequate drainage of all cavities of multicamerate abscess of the liver in 2 patients, progress of sacculated uremic peritonitis developing in presence of ascites in one patient, and arrosive hemorrhage in the cavity of pancreas pseudocyst in 2 persons. It is determined that it is necessary to include the spiral computer tomography to the complex of preoperative inspection of patients that allows to diagnose multicamerate abscess of the liver in time and to drain all the additional cavities adequately. 2 patients after paracentetic drain surgical interventions

  12. Effect of drains on the seepage of contaminants from subgrade tailings disposal areas

    International Nuclear Information System (INIS)

    Witten, A.J.; Pin, F.G.; Sharp, R.D.

    1984-01-01

    A numerical simulation study is performed to investigate the influence of ponded water and a bottom drain on the pathways for contaminant migration from a subgrade uranium mill tailings disposal pit. A numerical model is applied to a generic disposal pit constructed with a bottom clay liner and steep unlined sidewalls. The migration of a two-contaminant system is modeled assuming that neither contaminant decays and only one contaminant is retarded. Two dominant pathways are identified; one associated with lateral sidewall leakage and the other associated with transport through the bottom clay liner. It is found that the drain serves to reduce migration through the sidewall which, in turn, prevents the retarded contaminant from reaching the aquifer. The ponded water provides increased head which causes an accelerated vertical movement of moisture through the clay liner. 2 references, 8 figures

  13. Noise performance in AlGaN/GaN HEMTs under high drain bias

    International Nuclear Information System (INIS)

    Pang Lei; Pu Yan; Lin Xinyu; Wang Liang; Liu Jian

    2009-01-01

    The advent of fully integrated GaN PA-LNA circuits makes it meaningful to investigate the noise performance under high drain bias. However, noise performance of AlGaN/GaN HEMTs under high bias has not received worldwide attention in theoretical studies due to its complicated mechanisms. The noise value is moderately higher and its rate of increase is fast with increasing high voltage. In this paper, several possible mechanisms are proposed to be responsible for it. Impact ionization under high electric field incurs great fluctuation of carrier density, which increases the drain diffusion noise. Besides, higher gate leakage current related shot noise and a more severe self-heating effect are also contributors to the noise increase at high bias. Analysis from macroscopic and microscopic perspectives can help us to design new device structures to improve noise performance of AlGaN/GaN HEMTs under high bias. (semiconductor devices)

  14. Movement of gasified oil in an infinite stratum drained by a single well

    Energy Technology Data Exchange (ETDEWEB)

    Tomel' gas, V A

    1965-01-01

    This article presents a method of calculating the flow of gas and oil into a well, which drains a reservoir by the solution drive mechanism. The following conditions are assumed: (1) Initially, an infinite homogeneous reservoir is saturated with oil above the bubble point; (2) the well draining the reservoir is operated at constant pressure, below the bubble point; and (3) the reservoir contains 2 zones; the zone fartherest from the well contains only oil at a pressure above the bubble point, while the zone nearest the well contains both oil and gas. The pressure and oil saturation gradients around the well are calculated for a variety of conditions, and the results are shown graphically. As pressure drawdown increases, oil production increases and the gas factor at first decreases and then increases rapidly.

  15. The effect of drains on the seepage of contaminants from subgrade tailings disposal areas

    International Nuclear Information System (INIS)

    Witten, A.J.; Pin, F.G.; Sharp, R.D.

    1984-01-01

    A numerical simulation study is performed to investigate the influence of ponded water and a bottom drain on the pathways for contaminant migration from a subgrade uranium mill tailings disposal pit. A numerical model is applied to a generic disposal pit constructed with a bottom clay liner and steep unlined sidewalls. The migration of a two-contaminant system is modeled assuming that neither contaminant decays and only one contaminant is retarded. Two dominant pathways are indentified; one associated with lateral sidewall leakage and the other associated with transport through the bottom clay liner. It is found that the drain serves to reduce migration through the sidewall which, in turn, prevents the retarded contaminant from reaching the aquifer. The ponded water provides increased head which causes an accelarated vertical movement of moisture through the clay liner

  16. Conjunctivodacryocystorhinostomy using a high-density porous polyethylene-coated tear drain tube.

    Science.gov (United States)

    Pushker, Neelam; Khurana, Saurbhi; Shrey, Dinesh; Bajaj, Mandeep S; Chawla, Bhavna; Chandra, Mahesh

    2013-08-01

    To evaluate the outcome of conjunctivodacryocystorhinostomy using a high-density porous polyethylene (HDPP)-coated tear drain tube. Patients with epiphora due to a proximal lacrimal system block were included in a prospective interventional case study. A total of 22 eyes were treated with lacrimal bypass surgery using the HDPP-coated tube. On follow-up (12-41 months), 21 eyes had a patent well-positioned tube with subjective relief of epiphora. In one eye, a loose sleeve was noted during surgery. The tube dislodged postoperatively and was removed. A high success rate with only a few minor complications is achievable using a HDPP-coated tear drain tube for lacrimal bypass surgery. Long-term follow-up is required to look for tube blockage due to conjunctival or nasal mucosal overgrowth.

  17. Catheters, wires, tubes and drains on postoperative radiographs of pediatric cardiac patients: the whys and wherefores

    International Nuclear Information System (INIS)

    Teele, Sarah A.; Thiagarajan, Ravi R.; Emani, Sitaram M.; Teele, Rita L.

    2008-01-01

    Surgical treatment of congenital heart disease has advanced dramatically since the first intracardiac repairs in the mid-20th century. Previously inoperable lesions have become the focus of routine surgery and patients are managed successfully in intensive care units around the world. As a result, increasing numbers of postoperative images are processed by departments of radiology in children's hospitals. It is important that the radiologist accurately documents and describes the catheters, wires, tubes and drains that are present on the chest radiograph. This article reviews the reasons for the placement and positioning of perioperative equipment in children who have surgical repair of atrial septal defect, ventricular septal defect or transposition of the great arteries. Also included are a brief synopsis of each cardiac anomaly, the surgical procedure for its correction, and an in-depth discussion of the postoperative chest radiograph including illustrations of catheters, wires, tubes and drains. (orig.)

  18. X-ray K-edge analysis of drain lines in Wilhelm Hall, Ames Laboratory

    International Nuclear Information System (INIS)

    Jensen, T.; Whitmore, C.; Iowa State Univ., Ames, IA

    1999-01-01

    From August 12--27, 1998 X-ray K-edge measurements were made on drain lines in seven rooms in Wilhelm Hall, Ames Laboratory. The purpose of these measurements was to determine the extent of thorium (and other heavy metal) contamination inside these pipes. The K-edge method is a noninvasive inspection technique that can provide accurate quantification of heavy metal contamination interior to an object. Of the seven drain lines inspected, one was found to have no significant contamination, three showed significant thorium deposits, two showed mercury contamination, and one line was found to contain mercury, thorium and uranium. The K-edge measurements were found to be consistent with readings from hand-held survey meters, and provided much greater detail on the location and amount of heavy metal contamination

  19. Iron and silicon isotope behaviour accompanying weathering in Icelandic soils, and the implications for iron export from peatlands

    Science.gov (United States)

    Opfergelt, S.; Williams, H. M.; Cornelis, J. T.; Guicharnaud, R. A.; Georg, R. B.; Siebert, C.; Gislason, S. R.; Halliday, A. N.; Burton, K. W.

    2017-11-01

    Incipient warming of peatlands at high latitudes is expected to modify soil drainage and hence the redox conditions, which has implications for Fe export from soils. This study uses Fe isotopes to assess the processes controlling Fe export in a range of Icelandic soils including peat soils derived from the same parent basalt, where Fe isotope variations principally reflect differences in weathering and drainage. In poorly weathered, well-drained soils (non-peat soils), the limited Fe isotope fractionation in soil solutions relative to the bulk soil (Δ57Fesolution-soil = -0.11 ± 0.12‰) is attributed to proton-promoted mineral dissolution. In the more weathered poorly drained soils (peat soils), the soil solutions are usually lighter than the bulk soil (Δ57Fesolution-soil = -0.41 ± 0.32‰), which indicates that Fe has been mobilised by reductive mineral dissolution and/or ligand-controlled dissolution. The results highlight the presence of Fe-organic complexes in solution in anoxic conditions. An additional constraint on soil weathering is provided by Si isotopes. The Si isotope composition of the soil solutions relative to the soil (Δ30Sisolution-soil = 0.92 ± 0.26‰) generally reflects the incorporation of light Si isotopes in secondary aluminosilicates. Under anoxic conditions in peat soils, the largest Si isotope fractionation in soil solutions relative to the bulk soil is observed (Δ30Sisolution-soil = 1.63 ± 0.40‰) and attributed to the cumulative contribution of secondary clay minerals and amorphous silica precipitation. Si supersaturation in solution with respect to amorphous silica is reached upon freezing when Al availability to form aluminosilicates is limited by the affinity of Al for metal-organic complexes. Therefore, the precipitation of amorphous silica in peat soils indirectly supports the formation of metal-organic complexes in poorly drained soils. These observations highlight that in a scenario of decreasing soil drainage with

  20. Temporal observations of surface soil moisture using a passive microwave sensor

    International Nuclear Information System (INIS)

    Jackson, T.J.; O'Neill, P.

    1987-01-01

    A series of 10 aircraft flights was conducted over agricultural fields to evaluate relationships between observed surface soil moisture and soil moisture predicted using passive microwave sensor observations. An a priori approach was used to predict values of surface soil moisture for three types of fields: tilled corn, no-till corn with soybean stubble, and idle fields with corn stubble. Acceptable predictions were obtained for the tilled corn fields, while poor results were obtained for the others. The source of error is suspected to be the density and orientation of the surface stubble layer; however, further research is needed to verify this explanation. Temporal comparisons between observed, microwave predicted, and soil water-simulated moisture values showed similar patterns for tilled well-drained fields. Divergences between the observed and simulated measurements were apparent on poorly drained fields. This result may be of value in locating and mapping hydrologic contributing areas

  1. Spatial Variability of Tree Transpiration Along a Soil Drainage Gradient of Boreal Black Spruce Forest

    Science.gov (United States)

    Angstmann, J. L.; Ewers, B. E.; Kwon, H.; Bond-Lamberty, B.; Amiro, B.; Gower, S. T.

    2008-12-01

    Boreal forests are an integral component in obtaining a predictive understanding of global climate change because they comprise 33% of the world's forests and store large amounts of carbon. Much of this carbon storage is a result of peat formation in cold, poorly-drained soils. Transpiration plays a crucial role in the interaction between carbon and water cycles due to stomatal control of these fluxes. The primary focus of this study is to quantify the spatial variability and drivers of tree transpiration in boreal forest stands across a well- to poorly-drained soil drainage gradient. Species composition of this region of boreal forest changes during succession in well-drained soils from being primarily dominated by Picea mariana with co-dominant Pinus banksiana and Populus tremuloides in younger stands to being dominated solely by Picea marianain older stands. Poorly-drained soils are dominated by Picea mariana and change little with succession. Previous work in well-drained stands showed that 1) tree transpiration changed substantially with stand age due to sapwood-to-leaf area ratio dynamics and 2) minimum leaf water potential (Ψ) was kept constant to prevent excessive cavitation. We hypothesized that 1) minimum Ψ would be constant, 2) transpiration would be proportional to the sapwood-to-leaf area ratio across a soil drainage gradient, and 3) spatial relationships between trees would vary depending on stomatal responses to vapor pressure deficit (D). We tested these hypotheses by measuring Ψ of 33 trees and sap flux from 204 trees utilizing cyclic sampling constructed to study spatial relationships. Measurements were conducted at a 42-year-old stand representing maximum tree diversity during succession. There were no significant differences between growing season averaged Ψ in well- (-0.35 and -1.37 for pre-dawn and mid-day respectively) and poorly- drained soil conditions (-0.38 and -1.41 for pre-dawn and mid-day respectively) for Picea mariana. Water use

  2. Denial of student visas leads to brain drain from university research

    CERN Multimedia

    Wertheimer, L K

    2002-01-01

    America's move to shut the gate on student visas after the terrorist attack on the Twin Towers, has created a brain drain for universities that rely on top foreign students to help with scientific research. Professors, graduate school deans and officials from national science societies say hundreds of foreign students recruited to work on projects in such areas as physics, math and petroleum engineering they couldn't get visas this fall. Some gave up and went to other countries instead (2 pages).

  3. Role of wound instillation with bupivacaine through surgical drains for postoperative analgesia in modified radical mastectomy

    Directory of Open Access Journals (Sweden)

    Nirmala Jonnavithula

    2015-01-01

    Full Text Available Background and Aims: Modified Radical Mastectomy (MRM is the commonly used surgical procedure for operable breast cancer, which involves extensive tissue dissection. Therefore, wound instillation with local anaesthetic may provide better postoperative analgesia than infiltration along the line of incision. We hypothesised that instillation of bupivacaine through chest and axillary drains into the wound may provide postoperative analgesia. Methods: In this prospective randomised controlled study 60 patients aged 45-60 years were divided into three groups. All patients were administered general anaesthesia. At the end of the surgical procedure, axillary and chest wall drains were placed before closure. Group C was the control with no instillation; Group S received 40 ml normal saline, 20 ml through each drain; and Group B received 40 ml of 0.25% bupivacaine and the drains were clamped for 10 min. After extubation, pain score for both static and dynamic pain was evaluated using visual analog scale and then 4 th hourly till 24 h. Rescue analgesia was injection tramadol, if the pain score exceeds 4. Statistical analysis was performed using SPSS version 13. Results : There was a significant difference in the cumulative analgesic requirement and the number of analgesic demands between the groups (P: 0.000. The mean duration of analgesia in the bupivacaine group was 14.6 h, 10.3 in the saline group and 4.3 h in the control group. Conclusion : Wound instillation with local anaesthetics is a simple and effective means of providing good analgesia without any major side-effects.

  4. Lawps ion exchange column gravity drain of spherical resorcinol formaldehyde resin

    Energy Technology Data Exchange (ETDEWEB)

    Duignan, M. R. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Herman, D. T. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Restivo, M. L. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Burket, P. R. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2016-01-28

    Experiments at several different scales were performed to understand the removal of spherical resorcinol formaldehyde (sRF) ion exchange resin using a gravity drain system with a valve located above the resin screen in the ion exchange column (IXC). This is being considered as part of the design for the Low Activity Waste Pretreatment System (LAWPS) to be constructed at the DOE Hanford Site.

  5. An Experimental Study of the Drained Capacity of Bucket Foundations for Offshore Applications

    DEFF Research Database (Denmark)

    Ibsen, Lars Bo; Barari, Amin; Larsen, Kim André

    2013-01-01

    Today, wind energy offers the most competitive production prices for renewable energy. Therefore there are strong political and industrial forces, especially in northern Europe, which support the development of the offshore wind industry. The present paper presents the results of drained tests on....... Based on the results of the analyses, new failure criteria are calibrated for bucket foundations, in contrast to previous studies using the failure envelop e approach which have suggested that yield surface is constant in shape....

  6. Managing health worker migration: a qualitative study of the Philippine response to nurse brain drain

    Directory of Open Access Journals (Sweden)

    Dimaya Roland M

    2012-12-01

    Full Text Available Abstract Background The emigration of skilled nurses from the Philippines is an ongoing phenomenon that has impacted the quality and quantity of the nursing workforce, while strengthening the domestic economy through remittances. This study examines how the development of brain drain-responsive policies is driven by the effects of nurse migration and how such efforts aim to achieve mind-shifts among nurses, governing and regulatory bodies, and public and private institutions in the Philippines and worldwide. Methods Interviews and focus group discussions were conducted to elicit exploratory perspectives on the policy response to nurse brain drain. Interviews with key informants from the nursing, labour and immigration sectors explored key themes behind the development of policies and programmes that respond to nurse migration. Focus group discussions were held with practising nurses to understand policy recipients’ perspectives on nurse migration and policy. Results Using the qualitative data, a thematic framework was created to conceptualize participants’ perceptions of how nurse migration has driven the policy development process. The framework demonstrates that policymakers have recognised the complexity of the brain drain phenomenon and are crafting dynamic policies and programmes that work to shift domestic and global mindsets on nurse training, employment and recruitment. Conclusions Development of responsive policy to Filipino nurse brain drain offers a glimpse into a domestic response to an increasingly prominent global issue. As a major source of professionals migrating abroad for employment, the Philippines has formalised efforts to manage nurse migration. Accordingly, the Philippine paradigm, summarised by the thematic framework presented in this paper, may act as an example for other countries that are experiencing similar shifts in healthcare worker employment due to migration.

  7. Dynamic behavior of potentially unstable soils and application of model for seismic risk reduction from liquefaction occurrence

    International Nuclear Information System (INIS)

    Sheshov, Vlatko

    2002-11-01

    Throughout the last decades, liquefaction phenomenon has been one of the most frequently discussed subjects in geotechnical earthquake engineering. Liquefaction has been a problem arousing considerable attention among the world scientists. The consequences from liquefaction occurrence have been present after each stronger earthquake. We have been witnesses of several strong earthquakes (Kobe - Japan, Chi Chi-Taiwan, Bhuj-India) that have occurred in the last decade. In these earthquakes, the liquefaction phenomenon caused severe damage to structures, loss of their functioning and indirect loss of human lives. Liquefaction as a phenomenon should not arouse fear but should call for serious elaboration and attention instead. The destructive nature of liquefaction could be mitigated, i.e., overcome in two ways: avoiding construction at locations characterized by high liquefaction potential which is not always possible and taking of measures for improvement of foundation soil. Finding out suitable measures for improvement of soil and thus mitigating the liquefaction potential has been the main incentive for the elaboration of this dissertation. The dissipation method involving the use of vertical drains as one of the measures for improvement of soils has been elaborated in details in this scientific work. The doctoral dissertation has been realized through experimental and analytical investigations. The experimental investigations done in the first phase represent model seismic shaking table tests of the efficiency of vertical drains (prefabricated and gravel drains). The analytical investigations in this phase have involved mathematical simulation of the effect of vertical drains upon pore pressure state during the experiments. The second phase of the experimental investigations has involved model tests of the behavior of pile foundations in soils susceptible to liquefaction with installed prefabricated drains. In this phase, the 'p - y' relationships have been

  8. Carbon storage change in a partially forestry-drained boreal mire determined through peat column inventories

    Energy Technology Data Exchange (ETDEWEB)

    Pitkanen, A.; Tahvanainen, T.; Simola, H. [Univ. of Eastern Finland, Joensuu (Finland). Dept. pf Biology; Turunen, J. [Geological Survey of Finland, Kuopio (Finland)

    2013-09-01

    To study the impact of forestry drainage on peat carbon storage, we cored paired quantitative peat samples from undrained and drained sides of an eccentric bog. Five pairs of 0 to {<=} 100-cm-deep surface-peat cores, and a pair of profiles representing the full peat deposit provided stratigraphic evidence of marked loss of surface peat due to drainage. For the drained side cores, we found a relative subsidence of 25-37 cm of the surface, and a loss of about 10 kg{sub DW}{sup m-2}, corresponding to 131 {+-} 28 g C m{sup -2} a{sup -1} (mean {+-} SE) for the post-drainage period. Similar peat loss was also found in the full deposit profiles, thus lending credibility to the whole-column inventory approach, even though the decrease (9 kg{sub DW} m{sup -2}) was relatively small in comparison with the total carbon storage (233 and 224 kg{sub DW} m{sup -2} for the undrained and drained sides, respectively). (orig.)

  9. The value of cholangiography through Jackson-Pratt drains in the management of postoperative biliary injuries.

    Science.gov (United States)

    Macedo, Francisco Igor B; Casillas, Victor J; Davis, James S; Levi, Joe U; Sleeman, Danny

    2014-01-01

    Iatrogenic biliary injury is the most significant complication after laparoscopic cholecystectomy. We present our experience with an alternative diagnostic approach using transcatheter cholangiography (TCC) through a Jackson-Pratt (JP) drain and discuss potential benefits and limitations of the technique. From March 2002 to February 2012, 40 patients with major postoperative biliary injury underwent biliary reconstruction at our institution. Mean age was 51.7 ± 18.1 years (range, 19 to 86 years) with 30 (75%) females. Seventeen (42.5%) injuries were detected intraoperatively and in 13 (32.5%) cases, JP drains were placed for biliary drainage. Lesions were classified according to Bismuth grade: I (10 patients [25%]), II (10 patients [25%]), III (six patients [15%]), IV (10 patients [25%]), and V (four patients [10%]). TCC was performed in seven patients with JP drains (53.8%). It fully defined the injury site in three cases of limited magnetic resonance cholangiopancreatography (MRCP) such as common hepatic duct and common bile duct leaks and in four cases (57.1%) that endoscopic retrograde cholangiopancreatography (ERCP) was limited as a result of clipping of the distal common bile duct. TCC showed promising results in cases of limited MRCP and ERCP such as fistulous orifices or leakage. It may represent an alternative adjunct in the diagnostic armamentarium of complex biliary injuries.

  10. Technical meeting on decommissioning of fast reactors after sodium draining. Working material

    International Nuclear Information System (INIS)

    2005-01-01

    The objective of the technical meeting was to provide a forum for in-depth scientific and technical exchange on topics related to the decommissioning experience with fast reactors, in particular with regard to the decommissioning of components after sodium draining. Accordingly, the scope of the meeting covers the review and analyses of the experience gained from the decommissioning of both active sodium loops and sodium cooled fast reactors (e.g., KNK II, Superphenix, RAPSODIE, EBR-II, FERMI, BN-350, BR-10). It is expected that the outcome of the meeting will contribute to the Agency initiative to preserve fast reactor data and knowledge. The main focus of the technical meeting was given on the decommissioning of both active loop and reactor components (e.g., the primary vessel of a sodium-cooled reactor) that have been drained of sodium, but that still conserve some residual amounts of sodium (e.g., films covering the entire surface of the component, or particular sodium heels that cannot be drained)

  11. Wound healing without drains in posterior spinal fusion in idiopathic scoliosis

    International Nuclear Information System (INIS)

    Alsiddiky, A.; Nisar, K.A.; Alhuzaimi, F.; Albishi, W.; Alnuaim, B.; Albarrag, M.; Meo, S.A.

    2013-01-01

    To determine the frequency of wound infection and neurological injuries in patients with idiopathic scoliosis who underwent posterior spinal fusion without use of drains. Study Design: Case series. Place and Duration of Study: Department of Orthopaedics, College of Medicine, King Saud University, Riyadh, Kingdom of Saudi Arabia, from February 2007 to June 2010. Methodology: Patients who underwent similar technique of posterior spinal fusion instrumentation for the correction of scoliosis without use of drain were included. Wound Demographics, wound healing, complications and duration of hospital stay were considered and described as frequency and mean values. Results: The average age at the time of surgery was 12.80 +- 1.30 years, duration of surgery was 3.80 +- 0.86 hours, hospital stay was 3.84 +- 0.78 days and patients were followed-up over the last 30 months. There was no incidence of any neurological complication and deep infection. However, only 2 (4.16%) cases with superficial skin infection were treated with dressing and antibiotics with full recovery. Conclusion: The wound healing is adequate without using drain for patients with idiopathic scoliosis who underwent posterior spinal fusion and instrumentation when good wash, watertight closure technique and appropriate antibiotics coverage is provided. (author)

  12. No-Drain Single Incision Liposuction Pull-Through Technique for Gynecomastia.

    Science.gov (United States)

    Khalil, Ashraf A; Ibrahim, Amr; Afifi, Ahmed M

    2017-04-01

    Several different methods have been proposed for treatment of gynecomastia, depending on the amount of breast enlargement and skin redundancy. The liposuction pull-through technique has been proposed as an efficacious treatment for many gynecomastia cases. This work aims to study the outcome of this technique when applied as an outpatient procedure, without the use of drains and through a single incision. Fifty-two patients with bilateral gynecomastia without significant skin excess were included in this study. The liposuction pull-through technique was performed through a single incision just above the inframammary fold and without the use of drains. Patients were followed up for 6 months. The proposed technique was able to treat the gynecomastia in all patients, with a revision rate of 1.9% to remove residual glandular tissues. There were no seromas, hematomas, nipple distortion, permanent affection of nipple sensation or wound healing problems. The liposuction pull-through technique is an effective treatment for gynecomastia without significant skin redundancy. It combines the benefits of the direct excision of glandular tissues, with the minimally invasive nature of liposuction. Performing the procedure through a single incision without the use of drains and without general anesthesia is a safe alternative. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors http://www.springer.com/00266 .

  13. Modelling of the draining of a molten glass heated by induction

    International Nuclear Information System (INIS)

    Lima-Da-Silva, Marcio

    2014-01-01

    This thesis is part of the development of a new technology of oxides melting in a furnace heated by induction. The technology studied involves strong interactions between electromagnetic, thermal and hydrodynamic phenomena in a flow with physical properties strongly dependents of the temperature. The aim of the thesis is the modelling of the process by coupling closely the Joule heating, the mechanical stirring and the draining of the furnace. The modeling of the time evolution of the interface between glass and air during the emptying of the cold crucible was performed. Regarding the methodology, we chose to combine two scientific codes: Flux for the electromagnetic calculation and Fluent for thermal-hydraulics. The evolution of the free surface was treated by the multiphasic method 'Volume-Of-Fluid - VOF' and the mechanical stirring by the 'Moving Reference Frame' and the 'Sliding Mesh'. First of all, we considered the draining of a tank filled with a silicon oil of high-viscosity without mechanical stirring. This initial model took into account studies of hydraulic similarity between the silicon oil and the glass. Then we superimposed the forced flow creates by the mechanical stirrer, the thermal and the electromagnetic phenomena in order to model the flow of the molten glass. The final model can provide various parameters, including the time needed to drain the furnace, the heat transfer flux and the time evolution of the mass flow rate and of the temperature inside de furnace. (author) [fr

  14. Effect of Needle Aspiration of Pneumothorax on Subsequent Chest Drain Insertion in Newborns

    DEFF Research Database (Denmark)

    Murphy, Madeleine C; Heiring, Christian; Doglioni, Nicoletta

    2018-01-01

    Importance: Treatment options for a symptomatic pneumothorax in newborns include needle aspiration (NA) and chest drain (CD) insertion. There is little consensus as to the preferred treatment, reflecting a lack of evidence from clinical trials. Objective: To investigate whether treating pneumotho......Importance: Treatment options for a symptomatic pneumothorax in newborns include needle aspiration (NA) and chest drain (CD) insertion. There is little consensus as to the preferred treatment, reflecting a lack of evidence from clinical trials. Objective: To investigate whether treating...... was 5 tertiary European neonatal intensive care units. Infants receiving respiratory support (endotracheal ventilation, continuous positive airway pressure, or supplemental oxygen >40%) who had a pneumothorax on CR that clinicians deemed needed treatment were eligible for inclusion. Interventions...... was inserted if clinicians deemed that the response was inadequate. For CD insertion, a drain was inserted between the ribs and was left in situ. Main Outcomes and Measures: The primary outcome was whether a CD was inserted on the side of the pneumothorax within 6 hours of diagnosis. Results: A total of 76...

  15. Sediment and Nutrient Contributions from Subsurface Drains and Point Sources to an Agricultural Watershed

    Directory of Open Access Journals (Sweden)

    Bonnie Ball Coelho

    2010-03-01

    Full Text Available Excess sediment and nutrients in surface waters can threaten aquatic life. To determine the relative importance of subsurface drainage as a pathway for movement of sediment and nutrients to surface waters, loading from various tile systems was compared to that from sewage treatment plants (STP within the same watershed. Movement through tiles comprised 1 to 8% of estimated total (overland plus tile annual sediment loading from the respective areas drained by the tile. Load during the growing season from five closed drain- age systems without surface inlets averaged 5 kg sediment/ha, 0.005 kg dissolved reactive P (DRP/ha, 0.003 kg NH4-N/ha, and 3.8 kg NO3-N/ha; and from two open drainage systems with surface inlets averaged 14 kg sediment/ha, 0.03 kg DRP/ha, 0.04 kg NH4-N/ha, and 3.1 kg NO3-N/ha. The eight STP contributed about 44 530 kg suspended sediments, 3380 kg total P, 1340 kg NH4-N, and 116 900 kg NO3-N to the watershed annually. Drainage systems added less NH4-N and P, but more NO3-N and suspended solids to surface waters than STP. Tile drainage pathways for NO3-N, STP in the case of P, and overland pathways for sediment are indicated as targets to control loading in artificially drained agricultural watersheds.

  16. Characteristics of the overflow pollution of storm drains with inappropriate sewage entry.

    Science.gov (United States)

    Yin, Hailong; Lu, Yi; Xu, Zuxin; Li, Huaizheng; Schwegler, Benedict R

    2017-02-01

    To probe the overflow pollution of separate storm drains with inappropriate sewage entries, in terms of the relationship between sewage entries and the corresponding dry-weather and wet-weather overflow, the monitoring activities were conducted in a storm drainage system in the Shanghai downtown area (374 ha). In this study site, samples from inappropriately entered dry-weather sewage and the overflow due to storm pumps operation on dry-weather and wet-weather days were collected and then monitored for six water quality constituents. It was found that overflow concentrations of dry-weather period could be higher than those of wet-weather period; under wet-weather period, the overflow concentrations of storm drains were close to or even higher than that of combined sewers. Relatively strong first flush mostly occurred under heavy rain that satisfied critical rainfall amount, maximum rainfall intensity, and maximum pumping discharge, while almost no first flush effect or only weak first flush effect was found for the other rainfall events. Such phenomenon was attributed to lower in-line pipe storage as compared to that of the combined sewers, and serious sediment accumulation within the storm pipes due to sewage entry. For this kind of system, treating a continuous overflow rate is a better strategy than treating the maximum amount of early part of the overflow. Correcting the key inappropriate sewage entries into storm drains should also be focused.

  17. In Vitro Evaluation of Evacuated Blood Collection Tubes as a Closed-Suction Surgical Drain Reservoir.

    Science.gov (United States)

    Heiser, Brian; Okrasinski, E B; Murray, Rebecca; McCord, Kelly

    The initial negative pressures of evacuated blood collection tubes (EBCT) and their in vitro performance as a rigid closed-suction surgical drain (CSSD) reservoir has not been evaluated in the scientific literature despite being described in both human and veterinary texts and journals. The initial negative pressures of EBCT sized 3, 6, 10, and 15 mL were measured and the stability of the system monitored. The pressure-to-volume curve as either air or water was added and maximal filling volumes were measured. Evacuated blood collection tubes beyond the manufacture's expiration date were evaluated for initial negative pressures and maximal filling volumes. Initial negative pressure ranged from -214 mm Hg to -528 mm Hg for EBCT within the manufacturer's expiration date. Different pressure-to-volume curves were found for air versus water. Optimal negative pressures of CSSD are debated in the literature. Drain purpose and type of exudates are factors that should be considered when deciding which EBCT size to implement. Evacuated blood collection tubes have a range of negative pressures and pressure-to-volume curves similar to previously evaluated CSSD rigid reservoirs. Proper drain management and using EBCT within labeled expiration date are important to ensure that expected negative pressures are generated.

  18. Stable carbon and nitrogen isotopes in vertical peat profiles of natural and drained boreal peatlands

    Science.gov (United States)

    Nykänen, Hannu; Mpamah, Promise; Rissanen, Antti; Pitkänen, Aki; Turunen, Jukka; Simola, Heikki

    2015-04-01

    Peatlands form a significant carbon pool in the global carbon cycle. Change in peat hydrology, due to global warming is projected to change microbiological processes and peat carbon pool. We tested if bulk stable carbon and nitrogen isotopes serve as indicators of severe long term drying in peatlands drained for forestry. Depth profile analysis of peat, for their carbon and nitrogen content as well as their carbon and nitrogen stable isotopic signatures, were conducted for peatlands in southern and eastern Finland, having ombrotrophic and minerotrophic natural and corresponding drained pairs or separate drained sites. The selection of sites allowed us to compare changes due to different fertility and changes due to long term artificial drying. Drainage lasting over 40 years has led to changes in hydrology, vegetation, nutrient mineralization and respiration. Furthermore, increased nutrient uptake and possible recycling of peat nitrogen and carbon trough vegetation back to the peat surface, also possibly has an effect on the stable isotopic composition of peat carbon and nitrogen. We think that drainage induced changes somehow correspond to those caused by changed hydrology due to climate change. We will present data from these measurements and discuss their implications for carbon and nitrogen flows in peatlands.

  19. Navajo Nation Brain Drain: An Exploration of Returning College Graduates’ Perspectives

    Directory of Open Access Journals (Sweden)

    Quintina Ava Bearchief-Adolpho

    2017-01-01

    Full Text Available American Indian tribes face the phenomenon known across the world as the brain drain. They invest millions of dollars in educating their members only to have little return on their investment. Many nation members leave reservations to get postsecondary education but never return. Those who get education off the reservation and choose to return are the exception to this rule. Although there is an abundance of literature regarding brain drain across the world, there has been little research done with American Indians. In order to begin to understand the brain drain phenomenon, this study analyzed unstructured qualitative interviews with 17 Navajo Nation members who left their reservation, obtained a degree, and returned to work on the reservation. Themes resulting from the hermeneutic analysis of transcribed interviews were (a Family Support, (b Community, (c Cultural Identity, (d the Simple Life, (e Reservation Economy, and (f Commitment to the Reservation. The analysis found that constant, lengthy, and meaningful relationships were motivating factors in drawing participants back to contribute to their reservations. Further study is needed to understand how communities and tribes can ensure that these relationships are built and maintained.

  20. A low on-resistance SOI LDMOS using a trench gate and a recessed drain

    International Nuclear Information System (INIS)

    Ge Rui; Luo Xiaorong; Jiang Yongheng; Zhou Kun; Wang Pei; Wang Qi; Wang Yuangang; Zhang Bo; Li Zhaoji

    2012-01-01

    An integrable silicon-on-insulator (SOI) power lateral MOSFET with a trench gate and a recessed drain (TGRD MOSFET) is proposed to reduce the on-resistance. Both of the trench gate extended to the buried oxide (BOX) and the recessed drain reduce the specific on-resistance (R on,sp ) by widening the vertical conduction area and shortening the extra current path. The trench gate is extended as a field plate improves the electric field distribution. Breakdown voltage (BV) of 97 V and R on,sp of 0.985 mΩ·cm 2 (V GS = 5 V) are obtained for a TGRD MOSFET with 6.5 μm half-cell pitch. Compared with the trench gate SOI MOSFET (TG MOSFET) and the conventional MOSFET, R on,sp of the TGRD MOSFET decreases by 46% and 83% at the same BV, respectively. Compared with the SOI MOSFET with a trench gate and a trench drain (TGTD MOSFET), BV of the TGRD MOSFET increases by 37% at the same R on,sp . (semiconductor devices)

  1. Structural alterations in tumor-draining lymph nodes before papillary thyroid carcinoma metastasis.

    Science.gov (United States)

    Hinson, Andrew M; Massoll, Nicole A; Jolly, Lee Ann; Stack, Brendan C; Bodenner, Donald L; Franco, Aime T

    2017-08-01

    The purpose of this study was to define and characterize the thyroid tumor-draining lymph nodes in genetically engineered mice harboring thyroid-specific expression of oncogenic Braf V600E with and without Pten insufficiency. After intratumoral injection of methylene blue, the lymphatic drainage of the thyroid gland was visualized in real time. The thyroid gland/tumor was resected en bloc with the respiratory system for histological analysis. Although mice harboring Braf V600E mutations were smaller in body size compared with their wild-type (WT) littermates, the size of their thyroid glands and deep cervical lymph nodes were significantly larger. Additionally, the tumor-draining lymph nodes showed increased and enlarged lymphatic sinuses that were distributed throughout the cortex and medulla. Tumor-reactive lymphadenopathy and histiocytosis, but no frank metastases, were observed in all mice harboring Braf V600E mutations. The tumor-draining lymph nodes undergo significant structural alterations in immunocompetent mice, and this may represent a primer for papillary thyroid carcinoma (PTC) metastasis. © 2017 Wiley Periodicals, Inc.

  2. Restructuring brain drain: strengthening governance and financing for health worker migration

    Directory of Open Access Journals (Sweden)

    Tim K. Mackey

    2013-01-01

    Full Text Available Background: Health worker migration from resource-poor countries to developed countries, also known as ‘‘brain drain’’, represents a serious global health crisis and a significant barrier to achieving global health equity. Resource-poor countries are unable to recruit and retain health workers for domestic health systems, resulting in inadequate health infrastructure and millions of dollars in healthcare investment losses. Methods: Using acceptable methods of policy analysis, we first assess current strategies aimed at alleviating brain drain and then propose our own global health policy based solution to address current policy limitations. Results: Although governments and private organizations have tried to address this policy challenge, brain drain continues to destabilise public health systems and their populations globally. Most importantly, lack of adequate financing and binding governance solutions continue to fail to prevent health worker brain drain. Conclusions: In response to these challenges, the establishment of a Global Health Resource Fund in conjunction with an international framework for health worker migration could create global governance for stable funding mechanisms encourage equitable migration pathways, and provide data collection that is desperately needed.

  3. Modeling and risk assessment of a 30-Year-old subsurface radioactive-liquid drain field

    Science.gov (United States)

    Dawson, Lon A.; Pohl, Phillip I.

    1997-11-01

    The contamination from a 30-year-old radioactive liquid drain field was assessed for movement in the subsurface and potential risks to humans. This assessment included determining field concentrations of cesium 137 (137Cs) and other inorganic contaminants and modeling of the flow and transport of the liquid waste that was sent to the drain field. The field investigation detected no contamination deeper than 15 feet (4.6 m) from the bottom of the drain field. Prediction of the water content of the vadose zone showed no saturated conditions for times greater than 10 years after the known infiltration. Sensitivity analysis of the modeling parameters showed the equilibrium sorption coefficient to be the most important factor in predicting the contaminant plumes. Calibration of modeling results with field data gave a 137Cs sorption coefficient that is within the range of values found in the literature. The risk assessment for the site showed that the contamination poses no significant risk to human health.

  4. The "brain drain" of health care workers: causes, solutions and the example of Jamaica.

    Science.gov (United States)

    Lofters, Aisha K

    2012-07-18

    Despite much media attention being given to the physician shortage in Canada in recent years, this shortage pales in comparison to that seen in many middle- and low-income countries. A major cause of the shortage in these countries is the migration of health care workers from developing to developed nations, a phenomenon known as the "brain drain". The loss of these workers is having devastating impacts globally, particularly in Sub-Saharan Africa and the Caribbean. Causes of the "brain drain" are numerous and include poor working conditions in poorer countries and active recruitment by richer countries. Jamaica has been one of the countries in the Caribbean hardest hit by mass migration of health care workers. The multiple dimensions of Jamaica's health worker "brain drain" illustrate both the complexity of the issues reviewed in this commentary, and the net loss for low- and middle-income countries. Creative and sustainable solutions to the problem are actively being sought globally, but will require commitment and support from all nations as well as from international funding bodies if meaningful impacts on health are to be realized.

  5. Fertilizer placement and tillage effects on phosphorus leaching in fine-textured soils

    Science.gov (United States)

    Adoption of no-tillage in agricultural watersheds has resulted in substantial reductions in sediment and particulate phosphorus (P) delivery to surface waters. No-tillage, however, may result in increased losses of dissolved P in tile-drained landscapes due to the accumulation of P in surface soil l...

  6. Rapid nutrient leaching to groundwater and surface water in clay soil areas

    NARCIS (Netherlands)

    Bronswijk, J.J.B.; Hamminga, W.; Oostindie, K.

    1995-01-01

    The mechanism and magnitude of nitrate leaching from grassland on a heavy clay soil were investigated by measuring nitrogen input, and nitrate concentrations in groundwater and drain discharge for two years. A bromide tracer was applied to study solute transport mechanisms. Nitrate transport in the

  7. Behavior of granular rubber waste tire reinforced soil for application in geosynthetic reinforced soil wall

    Directory of Open Access Journals (Sweden)

    G. G. D. RAMIREZ

    Full Text Available AbstractLarge quantities of waste tires are released to the environment in an undesirable way. The potential use of this waste material in geotechnical applications can contribute to reducing the tire disposal problem and to improve strength and deformation characteristics of soils. This paper presents a laboratory study on the effect of granular rubber waste tire on the physical properties of a clayey soil. Compaction tests using standard effort and consolidated-drained triaxial tests were run on soil and mixtures. The results conveyed an improvement in the cohesion and the angle of internal friction the clayey soil-granular rubber mixture, depending on the level of confining stress. These mixtures can be used like backfill material in soil retaining walls replacing the clayey soil due to its better strength and shear behavior and low unit weight. A numerical simulation was conducted for geosynthetic reinforced soil wall using the clayey soil and mixture like backfill material to analyzing the influence in this structure.

  8. Effects of wood ash fertilization on forest floor greenhouse gas emissions and tree growth in nutrient poor drained peatland forests

    International Nuclear Information System (INIS)

    Ernfors, M.; Sikstroem, U.; Nilsson, M.; Klemedtsson, L.

    2010-01-01

    Wood ash (3.1, 3.3 or 6.6 tonnes dry weight ha -1 ) was used to fertilize two drained and forested peatland sites in southern Sweden. The sites were chosen to represent the Swedish peatlands that are most suitable for ash fertilization, with respect to stand growth response. The fluxes of carbon dioxide (CO 2 ), methane (CH 4 ) and nitrous oxide (N 2 O) from the forest floor, measured using opaque static chambers, were monitored at both sites during 2004 and 2005 and at one of the sites during the period 1 October 2007-1 October 2008. No significant (p > 0.05) changes in forest floor greenhouse gas exchange were detected. The annual emissions of CO 2 from the sites varied between 6.4 and 15.4 tonnes ha -1 , while the CH 4 fluxes varied between 1.9 and 12.5 kg ha -1 . The emissions of N 2 O were negligible. Ash fertilization increased soil pH at a depth of 0-0.05 m by up to 0.9 units (p 2 ha -1 year -1 and 0.52 m 2 ha -1 year -1 , respectively). The stand biomass, which was calculated using tree biomass functions, was not significantly affected by the ash treatment. The groundwater levels during the 2008 growing season were lower in the high ash dose plots than in the corresponding control plots (p < 0.05), indicating increased evapotranspiration as a result of increased tree growth. The larger basal area increment and the lowered groundwater levels in the high ash dose plots suggest that fertilization promoted tree growth, while not affecting greenhouse gas emissions.

  9. Relationship between electrical conductivity anisotropy and fabric anisotropy in granular materials during drained triaxial compressive tests: a numerical approach

    Science.gov (United States)

    Niu, Qifei; Revil, André; Li, Zhaofeng; Wang, Yu-Hsing

    2017-07-01

    The anisotropy of granular media and its evolution during shearing are important aspects required in developing physics-based constitutive models in Earth sciences. The development of relationships between geoelectrical properties and the deformation of porous media has applications to the monitoring of faulting and landslides. However, such relationships are still poorly understood. In this study, we first investigate the definition of the electrical conductivity anisotropy tensor of granular materials in presence of surface conductivity of the grains. Fabric anisotropy is related to the components of the fabric tensor. We define an electrical anisotropy factor based on the Archie's exponent second-order symmetric tensor m of granular materials. We use numerical simulations to confirm a relationship between the evolution of electrical and fabric anisotropy factors during shearing. To realize the simulations, we build a virtual laboratory in which we can easily perform synthetic experiments. We first simulate drained compressive triaxial tests of loose and dense granular materials (porosity 0.45 and 0.38, respectively) using the discrete element method. Then, the electrical conductivity tensor of a set of deformed synthetic samples is computed using the finite-difference method. The numerical results show that shear strains are responsible for a measurable anisotropy in the bulk conductivity of granular media. The observed electrical anisotropy response, during shearing, is distinct for dense and loose synthetic samples. Electrical and fabric anisotropy factors exhibit however a unique linear correlation, regardless of the shear strain and the initial state (porosity) of the synthetic samples. The practical implication of this finding confirms the usefulness of the electrical conductivity method in studying the fabric tensor of granular media. This result opens the door in using time-lapse electrical resistivity to study non-intrusively the evolution of anisotropy

  10. Novel technique of source and drain engineering for dual-material double-gate (DMDG) SOI MOSFETS

    Science.gov (United States)

    Yadav, Himanshu; Malviya, Abhishek Kumar; Chauhan, R. K.

    2018-04-01

    The dual-metal dual-gate (DMDG) SOI has been used with Dual Sided Source and Drain Engineered 50nm SOI MOSFET with various high-k gate oxide. It has been scrutinized in this work to enhance its electrical performance. The proposed structure is designed by creating Dual Sided Source and Drain Modification and its characteristics are evaluated on ATLAS device simulator. The consequence of this dual sided assorted doping on source and drain side of the DMDG transistor has better leakage current immunity and heightened ION current with higher ION to IOFF Ratio. Which thereby vesting the proposed device appropriate for low power digital applications.

  11. Migration of radionuclides in the soil-crop-food product system and assessment of agricultural countermeasures

    International Nuclear Information System (INIS)

    Bogdevitch, I.; Ageyets, V.

    1996-01-01

    Studies on dynamics of redistribution of radionuclides through of profile of the different soils on uncultivated agricultural lands of Belarus during the 1986-1995 period show that vertical migration occurs with low rate. In arable soils the radionuclides are distributed in comparatively uniform way through the whole depth of the 25-30 cm cultivated layer. Investigations on migration of radionuclides with wind erosion on the drained series of wet sandy and peat soils and water erosion on sloping lands show that one should take into consideration the secondary contamination of soils while forecasting a possible accumulation of radionuclides in farm products

  12. Absorption of technetium by plants in relation to soil type contamination level and time

    Energy Technology Data Exchange (ETDEWEB)

    Mousny, J.M.; Myttenaere, C. (Louvain Univ. (Belgium). Lab. de Physiologie Vegetale)

    1981-01-01

    Plants of Pisum sativum (var. Merveille de Kelvedon) were grown on seven typical european soils contaminated with different levels of /sup 99/Tc(0.17; 1.7 and 17 ..mu..Ci/kg). Added initially as pertechnetate, the technetium absorption has been studied for three successive cultures. The translocation of technetium from soil to plant leaves is high, but its transfer is reduced in soils rich in organic matter (Fen) or poorly drained (Braunerde). Aging reduces the technetium transfer and modify its relative distribution in plant (relatively more technetium is found in fruits); these results let suppose some modification of the technetium chemical form in soils with time.

  13. The relationship between dissolved organic carbon and hydro-climatic factors in peat-muck soil

    Directory of Open Access Journals (Sweden)

    Jaszczyński Jacek

    2015-03-01

    Full Text Available The object of this study was the concentration of dissolved organic carbon (DOC in soil solution related to groundwater table, soil temperature, moisture, redox potential and intensive storm rain and their changes during ten years (2001–2010. The studies were localized in drained and agriculturally used Kuwasy Mire situated in the middle basin of the Biebrza River, north-eastern Poland. The study site was situated on a low peat soil managed as intensively used grassland. The soil was recognized as peat-muck in the second stage of the mucking process. DOC concentration was determined by means of the flow colorimetric method using the Skalar equipment.

  14. Soils - Volusia County Soils (Polygons)

    Data.gov (United States)

    NSGIC Local Govt | GIS Inventory — Soils: 1:24000 SSURGO Map. Polygon boundaries of Soils in Volusia County, downloaded from SJRWMD and created by NRCS and SJRWMD. This data set is a digital version...

  15. Soil microbiology and soil health assessment

    Science.gov (United States)

    Soil scientists have long recognized the importance of soil biology in ecological health. In particular, soil microbes are crucial for many soil functions including decomposition, nutrient cycling, synthesis of plant growth regulators, and degradation of synthetic chemicals. Currently, soil biologis...

  16. Soil metagenomics and tropical soil productivity

    OpenAIRE

    Garrett, Karen A.

    2009-01-01

    This presentation summarizes research in the soil metagenomics cross cutting research activity. Soil metagenomics studies soil microbial communities as contributors to soil health.C CCRA-4 (Soil Metagenomics)

  17. Toxicity of Nitrification Inhibitors on Dehydrogenase Activity in Soils

    OpenAIRE

    Ferisman Tindaon; Gero Benckiser; Johannes C. G. Ottow

    2011-01-01

    The objective of this research was to determine the effects of nitrification inhibitors (NIs) such as 3,4-dimethylpyrazolephosphate=DMPP, 4-Chlor-methylpyrazole phosphate=ClMPP and dicyandiamide,DCD) which might be expected to inhibit microbial activity, on dehydrogenase activity (DRA),in three different soils in laboratory conditions. Dehydrogenase activity were assessed via reduction of 2-p-Iodophenyl-3-p-nitrophenyl-5-phenyltetrazoliumchloride (INT). The toxicity and dose response curve of...

  18. Stability charts for uniform slopes in soils with nonlinear failure envelopes

    OpenAIRE

    Eid, Hisham T.

    2014-01-01

    Based on the results of an extensive parametric study, charts were developed for assessment of the stability of uniform slopes in soils with nonlinear shear strength failure envelopes. The study was conducted using envelopes formed to represent the realistic shapes of soil nonlinear drained strength envelopes and the associated different degrees of nonlinearity. The introduction of a simple methodology to describe the nonlinear envelopes and a stability parameter, the value of which depends o...

  19. The project of the technological line of the electronic-beam drains disinfection in the infected hospitals' divisions and tubercular centres

    International Nuclear Information System (INIS)

    Shlapatska, V.V.; Volkonsky, V.G.; Sakhno, V.I.; Tomchaj, S.P.

    1999-01-01

    The purpose of the project was to create the electrophysical facility for the environmental protection from contamination by drains of the infected hospitals' divisions and tubercular centres and prevention of open water reservoirs. Development of the economically approved methods of the radiative disinfection of contaminated drains; development of the inexpensive compact facility for the electron-beam disinfection of small volume drains

  20. A prospective randomised study to compare the utility and outcomes of subdural and subperiosteal drains for the treatment of chronic subdural haematoma.

    LENUS (Irish Health Repository)

    Kaliaperumal, Chandrasekaran

    2012-11-01

    The usage of a drain following evacuation of a chronic subdural haematoma (CSDH) is known to reduce recurrence. In this study we aim to compare the clinical outcomes and recurrence rate of utilising two different types of drains (subperiosteal and subdural drain) following drainage of a CSDH.